National Weather Service United States Department of Commerce

Winter/Spring River Flood Potential Outlook
NWS Middle Atlantic River Forecast Center (MARFC)
State College, PA
2:30 pm EDT Wed, March 19, 2020

Outlook Number 20-06 - March 19, 2020


This Winter/Spring River Flood Potential Outlook is valid for the two-week period March 19 - April 2, 2020.

This outlook estimates the potential for river flooding (not flash flooding) to develop during the next week across the Middle Atlantic River Forecast Center`s (MARFC) area of responsibility (Mid- Atlantic Region) based on a current assessment of hydrometeorological factors which can contribute to river flooding. Across the MARFC area these factors include future weather conditions, recent precipitation, soil moisture, snow cover and snow water equivalent, river ice, streamflow and other factors. This outlook does not address the severity/extent of any future river flooding.

Remember, in the Mid-Atlantic region heavy rainfall is the primary factor which leads to river flooding. Heavy rainfall can rapidly cause river flooding any time of the year, even when overall river flood potential is considered to be low or below average.

TWO-WEEK RIVER FLOOD POTENTIAL - BELOW AVERAGE

The river flood potential during the next two weeks (through April 2, 2020) is below average across the entire MARFC service area. Factors which contribute to this assessment of river flood potential are discussed in some detail below.

CURRENT RIVER FLOODING - NONE

No flooding is currently occurring within the MARFC service area.

RECENT PRECIPITATION - BELOW AVERAGE

During the last 30 days (February 18 - March 18, 2020) observed precipitation across the entire MARFC region has been below to much-below average. Precipitation departure data can be seen at https://www.weather.gov/marfc/Precipitation_Departures.

SNOW CONDITIONS - BELOW NORMAL

As of this morning (March 19, 2020), little snow remains within the MARFC region. Snow conditions for this time of year are below normal for the about the northwestern quarter of the MARFC service area since snow is often still on the ground in this region well into March. Snow information can be found at https://www.weather.gov/marfc/Snow and https://www.nohrsc.noaa.gov.

RIVER ICE - NONE

Currently, no river ice remains on rivers within the MARFC service area and no additional river ice formation is expected.

STREAMFLOW CONDITIONS - VARIABLE

The latest data from the United States Geological Survey (USGS) indicates current streamflow conditions within the MARFC region range from near median to above median across the northern two-thirds of the region, decreasing to below median or even much-below median across the southern third. For current streamflow conditions please visit https://waterdata.usgs.gov/nwis/rt.

SOIL MOISTURE CONDITIONS - VARIABLE

A noticeable drying trend in soils has been observed during the last month or so within the MARFC service area. The long-term Palmer drought severity index is useful to estimate deep soil moisture conditions. The March 14, 2020 map (seen at https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/regional_monitoring/palmer.gif) suggests deep soils are still unusually moist to extremely moist across portions of NY and PA. Elsewhere, the map shows near-normal values, except over the Delmarva Peninsula and portions of northern VA where current values are below normal. Additional soil moisture data confirms some wet soils in portions of NY and PA, but elsewhere soils are now drier than usual for this time of year and are continuing to dry out. It has also been observed that vegetation activity is increasing and is further along than normal in much of the region. Increasing vegetation activity tends to decrease soil moisture conditions. Visit https://www.cpc.ncep.noaa.gov/products/Soilmst_Monitoring/ and then click on U.S. Monitoring.

GROUNDWATER - ABOUT AVERAGE

Within the MARFC service area, real-time USGS groundwater monitoring wells indicate current groundwater levels are generally about average for this time of year for most of the region, though there is an indication that levels are beginning to decrease across portions of the south. To see groundwater levels visit https://groundwaterwatch.usgs.gov.

RESERVOIR CONDITIONS - ABOUT AVERAGE

Most major reservoirs within the MARFC region are holding storages that are about average for this time of year. However, unless significant snow accumulates in the next few weeks, reservoirs that typically see rises due to spring snowmelt will not see those rises this spring. Instead, rises will depend on spring rainfall.

FUTURE WEATHER CONDITIONS -

Periods of light-moderate rain are expected ahead of/along a cold front expected to cross the region on Friday. Locally heavy rain is possible in thunderstorms. After frontal passage, a dry and much cooler weekend is expected. A coastal-type storm could then impact the region early next week. Depending on the track of that system, moderate-heavy precipitation - including potential for snow - could occur, especially across southern and eastern areas. In the longer range, the latest (March 18, 2020) outlooks issued by the NWS Climate Prediction Center suggest yet again that both temperatures and precipitation may be above normal when averaged over the nine-day period March 24-April 1, 2020. Visit https://www.cpc.ncep.noaa.gov/ to view the outlooks.

ENSEMBLE RIVER FORECASTS - VERY LIMITED THREAT OF RIVER FLOODING DEVELOPING DURING THE NEXT WEEK

The most recent runs (March 19, 2020) of the short-term (6-10 day) ensemble river forecasts, which take into account anticipated future weather conditions including precipitation and temperatures, show only a very limited threat of river flooding developing during the next 6-10 days (through the morning of March 29, 2020) within the MARFC region. Please visit https://www.weather.gov/erh/mmefs. SUMMARY Snow and river ice is essentially gone from the MARFC region in what has been a mostly below-normal winter for snow and river ice. There is, of course, still a chance for a late-season winter storm which could bring snow to portions of the area, maybe even early next week. Otherwise, any future river flooding will depend on spring rainfall patterns.

WATER SUPPLY OUTLOOK

According to the latest (March 17, 2020) U.S. Drought monitor (https://droughtmonitor.unl.edu), no drought conditions exist within the MARFC region. However, some abnormally dry conditions are beginning to show up in portions of NJ and NY. Please visit https://www.drought.gov, https://www.cpc.ncep.noaa.gov and https://www.weather.gov/marfc/WRO for additional drought and water supply information. It is worth noting that in general hydrologic conditions have begun to dry out over the last month. Recent precipitation has been below normal, streamflow is below normal for much of the region, and soils are slowly drying. In addition, those reservoirs in the region that normally see significant increases in pool elevations due to spring snowmelt will not see those rises this year, unless a late-season significant snowstorm occurs. Still, assuming near-normal precipitation occurs during the next few months, no water supply problems or shortages are anticipated anywhere within the MARFC region through May, 2020.

Please visit the NWS MARFC homepage at https://www.weather.gov/marfc or find us on Facebook at https://www.facebook.com/NWSMARFC and on Twitter @nwsmarfc.

This will be the last outlook issued by this office for this year, unless conditions warrant otherwise. SK

Winter/Spring River Flood Potential Outlook
NWS Middle Atlantic River Forecast Center (MARFC)
State College, PA
2:12 pm EDT Wed, March 11, 2020

Outlook Number 20-05A - March 11, 2020


This Winter/Spring River Flood Potential Outlook is valid for the one-week period March 12-19, 2020.

This outlook estimates the potential for river flooding (not flash flooding) to develop during the next week across the Middle Atlantic River Forecast Center`s (MARFC) area of responsibility (Mid- Atlantic Region) based on a current assessment of hydrometeorological factors which can contribute to river flooding. Across the MARFC area these factors include future weather conditions, recent precipitation, soil moisture, snow cover and snow water equivalent, river ice, streamflow and other factors. This outlook does not address the severity/extent of any future river flooding. Remember, in the Mid-Atlantic region heavy rainfall is the primary factor which leads to river flooding. Heavy rainfall can rapidly cause river flooding any time of the year, even when overall river flood potential is considered to be low or below average.

ONE-WEEK RIVER FLOOD POTENTIAL - BELOW AVERAGE

The river flood potential during the next week (through March 19, 2020) is below average across the entire MARFC service area. Factors which contribute to this assessment of river flood potential are discussed in some detail below.

CURRENT RIVER FLOODING - NONE

No flooding is currently occurring within the MARFC service area.

RECENT PRECIPITATION - BELOW AVERAGE

During the last 30 days (February 8 - March 8, 2020) observed precipitation across the entire MARFC region has been below to much-below average. Precipitation departure data can be seen at https://www.weather.gov/marfc/Precipitation_Departures.

SNOW CONDITIONS - BELOW NORMAL

As of this morning (March 11, 2020), within the MARFC region snow exists only in higher elevations and/or protected wooded areas across extreme northern portions of PA and NY. Not enough snow exists anywhere now to be a factor in causing river flooding within the MARFC region. Snow conditions for this time of year are below normal for the about the northwestern third of the MARFC service area since snow is often still on the ground in this region well into March. Snow information can be found at https://www.weather.gov/marfc/Snow and https://www.nohrsc.noaa.gov.

RIVER ICE - BELOW AVERAGE

Currently, little if any river ice remains on rivers within the MARFC service area. Current river ice conditions are below normal for roughly the northwestern quarter of the region since ice is still often observed on rivers in this region in March. No additional river ice formation is expected this cold season.

STREAMFLOW CONDITIONS - VARIABLE

The latest data from the United States Geological Survey (USGS) indicates current streamflow conditions within the MARFC region range from about median across the north, decreasing to below median or even much-below median across the remainder of the region. For current streamflow conditions please visit https://waterdata.usgs.gov/nwis/rt.

SOIL MOISTURE CONDITIONS - VARIABLE

A noticeable drying trend in soils has been observed during the last month or so within the MARFC service area. The long-term Palmer drought severity index is useful to estimate deep soil moisture conditions. The March 7, 2020 map (seen at https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/regional_monitoring/palmer.gif) suggests deep soils are still unusually moist to extremely moist across portions of NY and PA. Elsewhere, the map shows near-normal values, except over the Delmarva Peninsula and portions of northern VA where current values are below normal. Additional soil moisture data confirms some wet soils in portions of NY and PA, but elsewhere soils are now drier than usual for this time of year and are continuing to dry out. Visit https://www.cpc.ncep.noaa.gov/products/Soilmst_Monitoring/ and then click on U.S. Monitoring.

GROUNDWATER - ABOUT AVERAGE

Within the MARFC service area, real-time USGS groundwater monitoring wells indicate current groundwater levels are generally about average for this time of year for most of the region. To see groundwater levels visit https://groundwaterwatch.usgs.gov.

RESERVOIR CONDITIONS - ABOUT AVERAGE

Most major reservoirs within the MARFC region are holding storages that are about average for this time of year. However, unless significant snow accumulates in the next few weeks, reservoirs that typically see rises due to spring snowmelt will not see those rises this spring.

FUTURE WEATHER CONDITIONS -

One weather system moves through the region Thursday night/Friday producing generally light-moderate rain. Additional light-moderate rain may impact mostly southern portions of the region Sunday. Additional light-moderate precipitation is possible next Monday night/Tuesday. At this time no widespread heavy rain events are anticipated through midweek next week. The latest (March 10, 2020) longer-range weather outlooks issued by the NWS Climate Prediction Center suggest yet again that both temperatures and precipitation may be above normal when averaged over the nine-day period March 16-24, 2020. Visit https://www.cpc.ncep.noaa.gov/ to view the outlooks.

ENSEMBLE RIVER FORECASTS - VERY LIMITED THREAT OF RIVER FLOODING DEVELOPING DURING THE NEXT WEEK

The most recent runs (March 11, 2020) of the short-term (one week) ensemble river forecasts, which take into account anticipated future weather conditions including precipitation and temperatures, show only a very limited threat of river flooding developing during the next week (through the morning of March 17, 2020) within the MARFC region. Please visit https://www.weather.gov/erh/mmefs.

SUMMARY

Snow and river ice conditions are below or even much-below normal across roughly the northern third of the MARFC region, where snow and river ice is normally still found this time of year. Snow and river ice are no longer factors in determining this spring`s river flood potential, unless an unusual and significant late-season winter storm and prolonged cold snap occur. Weatherwise, a couple generally light-moderate mostly-rain events will move through the region during the next week. Based on current weather information, there appears to be little chance for widespread, heavy rainfall through midweek next week. In the longer range a continued mild and perhaps somewhat wetter weather pattern seems possible moving through into the second half of March.

WATER SUPPLY OUTLOOK

According to the latest (March 3, 2020) U.S. Drought monitor (https://droughtmonitor.unl.edu), no drought conditions exist within the MARFC region. Please visit https://www.drought.gov, https://www.cpc.ncep.noaa.gov and https://www.weather.gov/marfc/WRO for additional drought and water supply information. It is worth noting, however, that in general hydrologic conditions have begun to dry out over the last month. Recent precipitation has been below normal, streamflow is below normal for much of the region, and soils are slowly drying. In addition, those reservoirs in the region that normally see significant increases in pool elevations due to spring snowmelt will not see those rises this year, unless a late-season significant snowstorm occurs. Still, assuming near-normal precipitation for the next few months, no water supply problems or shortages are anticipated anywhere within the MARFC region through mid-May, 2020.

Please visit the NWS MARFC homepage at https://www.weather.gov/marfc or find us on Facebook at https://www.facebook.com/NWSMARFC and on Twitter @nwsmarfc.

The next outlook will be issued in one week, on or about March 18-19, 2020. SK

Winter/Spring River Flood Potential Outlook
NWS Middle Atlantic River Forecast Center (MARFC)
State College, PA
9:30 am EST Thu, March 5, 2020

Outlook Number 20-05 - March 5, 2020


This Winter/Spring River Flood Potential Outlook is valid for the one-week period March 5-12, 2020.

This outlook estimates the potential for river flooding (not flash flooding) to develop during the next week across the Middle Atlantic River Forecast Center`s (MARFC) area of responsibility (Mid- Atlantic Region) based on a current assessment of hydrometeorological factors which can contribute to river flooding. Across the MARFC area these factors include future weather conditions, recent precipitation, soil moisture, snow cover and snow water equivalent, river ice, streamflow and other factors. This outlook does not address the severity/extent of any future river flooding. Remember, in the Mid-Atlantic region heavy rainfall is the primary factor which leads to river flooding. Heavy rainfall can rapidly cause river flooding any time of the year, even when overall river flood potential is considered to be low or below average.

ONE-WEEK RIVER FLOOD POTENTIAL - GENERALLY BELOW AVERAGE

The river flood potential during the next week (through March 12, 2020) is somewhat below average across the entire MARFC service area. Factors which contribute to this assessment of river flood potential are discussed in some detail below.

CURRENT RIVER FLOODING - NONE

No flooding is currently occurring within the MARFC service area.

RECENT PRECIPITATION - VARIABLE

During the last 30 days (February 3 - March 3, 2020) observed precipitation across much of the MARFC region has been mostly near-to-above average. However, portions of northwestern VA, northeastern WV, western MD and south-central PA have seen somewhat below average precipitation. Precipitation departure data can be seen at https://www.weather.gov/marfc/Precipitation_Departures.

SNOW CONDITIONS - GENERALLY BELOW NORMAL

As of this morning (March 5, 2020), snow exists only across extreme northern portions of PA and NY within the MARFC region. Where there is snow, it is found mostly in higher elevations and/or protected wooded areas. In fact, at this time only the Tioughnioga River Basin in NY has what could be considered hydrologically significant snow, with snow water equivalent values of around an inch and a half. Even here, this is less snow than usual. Snow conditions are below/much-below normal for late winter across roughly the northwestern half of the MARFC region. Across the southeastern half of the MARFC region, no snow exists which is not uncommon and therefore about average for early March. In summary, snow conditions within the MARFC service are below normal, as they have been for much of this winter. Snow information can be found at https://www.weather.gov/marfc/Snow and https://www.nohrsc.noaa.gov.

RIVER ICE - BELOW AVERAGE/AVERAGE

Currently, very little river ice exists on rivers within the MARFC service area. As such, current river ice conditions range from below/much below average for roughly the northwestern half of the region, and about average across the southeast where a lack of river ice in early March is not uncommon. It is now late enough in winter that significant river ice formation is very unlikely.

STREAMFLOW CONDITIONS - VARIABLE

The latest data from the United States Geological Survey (USGS) indicates current streamflow conditions within the MARFC region range from above median across the north, decreasing to near median across the central, and finally to below median across the south. For current streamflow conditions please visit https://waterdata.usgs.gov/nwis/rt.

SOIL MOISTURE CONDITIONS - VARIABLE

The long-term Palmer drought severity index is useful to estimate deep soil moisture conditions. The February 29, 2020 map (seen at https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/regional_ monitoring/palmer.gif) suggests deep soils are unusually moist to extremely moist across portions of NY and PA. Elsewhere, the map shows near-normal values, except over the Delmarva Peninsula where current values are below normal. Additional soil moisture data confirms some wet soils in portions of NY and PA. Please visit https://www.cpc.ncep.noaa.gov/products/Soilmst_Monitoring/ and then click on U.S. Monitoring.

GROUNDWATER - ABOUT AVERAGE

Within the MARFC service area, real-time USGS groundwater monitoring wells indicate current groundwater levels are generally about average for this time of year. To see groundwater levels visit https://groundwaterwatch.usgs.gov.

RESERVOIR CONDITIONS - ABOUT AVERAGE

Most major reservoirs within the MARFC region are holding storages that are about average for this time of year. However, unless significant snow accumulates in the next few weeks, reservoirs that typically see rises due to spring snowmelt will likely not see those rises this spring.

FUTURE WEATHER CONDITIONS 

One weather system moves through the region tomorrow into Saturday, producing generally light-moderate precipitation with some snow expected. Seasonably chilly temperatures Saturday will quickly warm up Sunday and continue to be on the mild side through Tuesday. Unsettled weather with additional periods of generally light-moderate precipitation, including some more snow, is then possible next Tue-Thu. The latest (March 4, 2020) longer-range weather outlooks issued by the NWS Climate Prediction Center suggest that both temperatures and precipitation will be above normal when averaged over the nine-day period March 10-18, 2020. Visit https://www.cpc.ncep.noaa.gov/ to view the outlooks.

ENSEMBLE RIVER FORECASTS - VERY LIMITED THREAT OF RIVER FLOODING DEVELOPING DURING THE NEXT WEEK

The most recent runs (March 4, 2020) of the short-term (one week) ensemble river forecasts, which take into account anticipated future weather conditions including precipitation and temperatures, show only a very limited threat of river flooding developing during the next week (through the morning of March 11, 2020) within the MARFC region. Please visit https://www.weather.gov/erh/mmefs.

SUMMARY

For this time of year, snow and river ice conditions are below or even much-below normal within the MARFC region. Much of the snow in northern PA and NY has melted without any flooding since two weeks ago. Weather-wise, a couple/few generally light-moderate precipitation events will move through the region during the next week, with some snow expected at times. Based on current weather information, there appears to be little chance for widespread, heavy rainfall through midweek next week. In the longer range a milder and perhaps somewhat wetter weather pattern seems possible heading into mid March.

WATER SUPPLY OUTLOOK

According to the latest (February 25, 2020) U.S. Drought monitor (https://droughtmonitor.unl.edu), no drought conditions exist within the MARFC region. Please visit https://www.drought.gov, https://www.cpc.ncep.noaa.gov and https://www.weather.gov/marfc/WRO for additional drought and water supply information. Assuming near-normal precipitation for the next few months, no water supply problems or shortages are anticipated anywhere within the MARFC region through mid-May, 2020.

Please visit the NWS MARFC homepage at https://www.weather.gov/marfc or find us on Facebook at https://www.facebook.com/NWSMARFC and on Twitter @nwsmarfc.

The next outlook will be issued in one week, on or about March 11-12, 2020.

SK

 

 

 

Winter/Spring River Flood Potential Outlook
NWS Middle Atlantic River Forecast Center (MARFC)
State College, PA
4:20pm EST Wed, Feb 19, 2020

Outlook Number 20-04 - February 19, 2020 


This Winter/Spring River Flood Potential Outlook is valid for the two-week period February 20-March 5, 2020.

This outlook estimates the potential for river flooding (not flash flooding) to develop during the next two weeks across the Middle 
Atlantic River Forecast Center's (MARFC) area of responsibility (Mid-Atlantic Region) based on a current assessment of hydrometeorological factors which can contribute to river flooding.  Across the MARFC area these factors include future weather conditions, recent precipitation, soil moisture, snow cover and snow water equivalent, river ice, streamflow, and others.  This outlook does not address the severity/extent of any future river flooding.

Remember, in the Mid-Atlantic region heavy rainfall is the primary factor which leads to river flooding.  Heavy rainfall can rapidly cause river flooding any time of the year, even when overall river flood potential is considered to be low or below average.

TWO-WEEK RIVER FLOOD POTENTIAL - AVERAGE

The river flood potential during the next two weeks (through March 5, 2020) is about average within the MARFC service area.  Factors which contribute to this assessment of river flood potential are discussed below.

CURRENT RIVER FLOODING - NONE

There is currently no river flooding occurring within the MARFC service  area.

RECENT PRECIPITATION - AVERAGE/ABOVE AVERAGE

During the last 30 days (January 20 - February 18, 2020) observed precipitation across most of the MARFC region has been near average 
to above average.  Portions of western/central VA in the Upper James River Basin have seen much-above average precipitation during the last month.  To view precipitation departure data please visit  https://www.weather.gov/marfc/Precipitation_Departures.

SNOW CONDITIONS - VARIABLE

As of this morning (February 19, 2020), generally continuous snow covers the ground across roughly the northern quarter of the MARFC 
region.   The snow/no-snow line runs through northern PA into the Catskill Mountains of NY.  The extent of snow cover within the MARFC region is below normal for late winter.  Where snow does exits, there is a sharp gradient in snow conditions heading north from central PA to southern NY.  Specifically, snow depths range from zero across central PA to nearly 15 inches across portions of the Upper Susquehanna River Basin in NY.  Likewise, snow water equivalent values increase from zero in central PA to 3-4 inches across portions of the Tioughnioga, Otselic and Chenango River Basins in NY.  In between these two extremes, most of the rest of northern PA and southern NY has snow depths of a few inches and snow water equivalent values of 0.50-2.0 inches.  Current snow conditions range from above average across extreme northern portions of the region in NY's Upper Susquehanna River Basin, decreasing to about average across southern NY, and finally below average across PA and NJ, as well as along and east of the Appalachians.  Finally, across the southeastern half of the MARFC region, no snow exists which is not uncommon and therefore about average.  In summary, the extent of snow cover within the MARFC service area is less than normal for this time of year, with snow being limited to just the northern quarter of the region.  Within the snow-covered region, conditions increase from below normal across the south to above normal across the far north.  Snow information can be found at https://www.weather.gov/marfc/Snow and https://www.nohrsc.noaa.gov.

RIVER ICE - BELOW AVERAGE/AVERAGE

Currently, river ice within the MARFC service area remains unusually limited in both extent and thickness for late winter.  As such, current river ice conditions are below/much below average for roughly the northwestern half of the region, and about average elsewhere.  It is becoming increasingly unlikely that significant river ice will form for the remainder of this winter.

STREAMFLOW CONDITIONS - AVERAGE/ABOVE AVERAGE

The latest data from the United States Geological Survey (USGS) indicates current streamflow conditions are generally near median to somewhat above median for the date.  For current streamflow conditions please visit https://waterdata.usgs.gov/nwis/rt.

SOIL MOISTURE CONDITIONS - VARIABLE

The long-term Palmer drought severity index is useful to estimate deep soil moisture conditions.  The February 15, 2020 map (seen at https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/regional_monitoring/palmer.gif) suggests deep soils are unusually moist to extremely moist across portions of NY and PA.  Elsewhere, the map shows near-normal to somewhat below-normal values.  Additional soil moisture data confirms some wet soils in portions of NY and PA.  Go to https://www.cpc.ncep.noaa.gov/products/Soilmst_Monitoring/ and then click on U.S. Monitoring to view this soil moisture information.

GROUNDWATER - AVERAGE/ABOVE AVERAGE

Within the MARFC service area, real-time USGS groundwater monitoring wells indicate current groundwater levels are generally in the average to above average range for this time of year.  Please visit https://groundwaterwatch.usgs.gov.

RESERVOIR CONDITIONS - AVERAGE/ABOVE AVERAGE

Most major reservoirs within the MARFC region are holding storages that are average to somewhat above average for this time of year.

FUTURE WEATHER CONDITIONS -

After a cold start, with even some snow expected in portions of VA, a gradually warmer and generally dry period is expected across the region into early next week.  Some lake-effect snow will also fall in NY early in the period.  The next chance of widespread precipitation is in the Monday-Tuesday time frame of next week.  The latest (February 19, 2020) longer-range weather outlooks issued by the NWS Climate Prediction Center suggest for the first time in quite a while that temperatures will be normal or below normal for the MARFC region when averaged over the nine-day period February 25-March 4, 2020.  Precipitation for the same nine-day period is most likely to be normal or above normal for most of the region.  Visit https://www.cpc.ncep.noaa.gov/ to view the outlooks.

ENSEMBLE RIVER FORECASTS - VERY LITTLE THREAT OF RIVER FLOODING 
DEVELOPING DURING THE NEXT WEEK

The most recent runs (February 19, 2020) of the short-term (one week) ensemble river forecasts, which take into account anticipated future weather conditions including precipitation and temperatures, show very little threat of river flooding developing during the next week (through the morning of February 25, 2020) within the MARFC region.  Please visit https://www.weather.gov/erh/mmefs.

SUMMARY

Some significant snow now exists across upper portions of the Susquehanna River Basin in NY and extreme northern PA.  However no heavy rain or significant snowmelt is anticipated for at least the next five days.  This snowpack, however, could be a factor with respect to river flood potential over the course of the next few 
weeks.  Otherwise, the river flood potential for the next two weeks for rivers within the MARFC region is near average.  The next widespread precipitation event looks to be next Monday-Tuesday, but at this time this event does not appear significant enough to produce river flooding, even with some snowmelt.  In the longer range, a somewhat cooler and perhaps somewhat drier weather pattern seems possible.

WATER SUPPLY OUTLOOK 

According to the latest (February 11, 2020) U.S. Drought monitor (https://droughtmonitor.unl.edu), no drought conditions exist within the MARFC region.  Please visit https://www.drought.govhttps://www.cpc.ncep.noaa.gov and https://www.weather.gov/marfc/wro_north for additional drought and water supply information.  Assuming near-normal precipitation for the next few months, no water supply shortages are anticipated anywhere within the MARFC region through mid-May, 2020.

Please visit the NWS MARFC homepage at https://www.weather.gov/marfc or find us on Facebook at https://www.facebook.com/NWSMARFC  and on Twitter@nwsmarfc.

The next outlook will be issued in two weeks, on or about March 4-5, 2020.

SK
 

Winter/Spring River Flood Potential Outlook
NWS Middle Atlantic River Forecast Center (MARFC)
State College, PA
3:27pm EST Wed, Feb 5, 2020

Outlook Number 20-03 - February 5, 2020


This Winter/Spring River Flood Potential Outlook is valid for the two-week period February 6-20, 2020.

This outlook estimates the potential for river flooding (not flash flooding) to develop during the next two weeks across the Middle Atlantic River Forecast Center's (MARFC) area of responsibility (Mid-Atlantic Region) based on a current assessment of hydrometeorological factors which can contribute to river flooding.  Across the MARFC area these factors include future weather conditions, recent precipitation, soil moisture, snow cover and snow water equivalent, river ice, streamflow, and others.  This outlook does not address the severity/extent of any future river flooding.

Remember, in the Mid-Atlantic region heavy rainfall is the primary factor which leads to river flooding.  Heavy rainfall can rapidly cause river flooding any time of the year, even when overall river flood potential is considered to be low or below average.

TWO-WEEK RIVER FLOOD POTENTIAL - ABOVE AVERAGE SOUTH AND EAST.

The river flood potential during the next two weeks (through February 20, 2020) is above average across southern and eastern portions of the region, and near average elsewhere.  Factors which contribute to this assessment of river flood potential are discussed below.

CURRENT RIVER FLOODING - NONE

There is currently no river flooding occurring within the MARFC service area.

RECENT PRECIPITATION - VARIABLE

During the last 30 days (January 6 - February 4, 2020) observed precipitation across much of the MARFC region has been average to below average.  In contrast, portions of western VA, eastern WV, western MD and southwestern PA observed above-average precipitation. To view precipitation departure data please visit https://www.weather.gov/marfc/Precipitation_Departures.

SNOW CONDITIONS - BELOW AVERAGE/AVERAGE

Generally continuous snow covers the ground across roughly the northern quarter of the MARFC region as of this morning (February 5, 2020).  The snow/no-snow line runs through northern PA into the Pocono/Catskill Mountains.  Similar to two weeks ago, the only snow of any hydrological significance within the MARFC service area is found across portions of central NY, where a few/several inches covers the ground.  The water contained in the snow in this area is in the 0.4-1.2 inch range, which is still below/much-below normal for this area for early February.  Like two weeks ago, snow conditions remain below/much-below average for the date across about the northwestern half of the region, and about average elsewhere. Snow information can be found at https://www.weather.gov/marfc/Snow 
and https://www.nohrsc.noaa.gov.

RIVER ICE - BELOW AVERAGE/AVERAGE

Currently, river ice within the MARFC service area remains unusually limited in both extent and thickness for early February.  In fact, there is very little river ice anywhere within the MARFC service area, and none is significant in terms of contributing to river flood potential.  As such, current river ice conditions are below/much below average for roughly the northwestern two-thirds of the region, and about average for the southeastern third.  Weather conditions for the next two weeks again suggest river ice conditions will remain insignificant.

STREAMFLOW CONDITIONS - VARIABLE

The latest data from the United States Geological Survey (USGS) indicates streamflow conditions are still somewhat above median across NY and portions of PA, but median/below median elsewhere.For current streamflow conditions please visit https://waterdata.usgs.gov/nwis/rt.

SOIL MOISTURE CONDITIONS - VARIABLE

The long-term Palmer drought severity index is useful to estimate deep soil moisture conditions.  The February 1, 2020 chart (seen at https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/regional_monitoring/palmer.gif) suggests deep soils are unusually moist to extremely moist across portions of NY and PA.  Elsewhere, the index map shows near-normal to below-normal values. Additional soil moisture data confirms some wet soils in portions of NY and PA.  Go to https://www.cpc.ncep.noaa.gov/products/Soilmst_Monitoring/ and then click on U.S. Monitoring to view this soil moisture information.

GROUNDWATER - NEAR NORMAL

Within the MARFC service area, real-time USGS groundwater monitoring wells continue to indicate groundwater levels are generally fairly close to normal for this time of year.  Please visit https://groundwaterwatch.usgs.gov.

RESERVOIR CONDITIONS - AVERAGE/ABOVE AVERAGE

Most major reservoirs within the MARFC region are holding storages that are average to somewhat above average for this time of year.

FUTURE WEATHER CONDITIONS - SIGNIFICANT RAIN EVENT FOR SOME

A complex storm system is expected to produce moderate-heavy precipitation across the region during the next two days.  One to three inches of rain (with isolated higher amounts) is possible across roughly the southeastern half of the MARFC region with moderate-heavy mixed precipitation likely elsewhere.  Some river flooding may develop across southern and eastern areas as a result of this next rain event.  Beyond this next event, an active weather pattern that seems more like March than February will likely bring additional moderate-heavy precipitation to the MARFC region during this outlook period.  The latest (February 5, 2020) longer-range weather outlooks issued by the NWS Climate Prediction Center again suggest that both temperatures and precipitation will be above normal for the MARFC region when averaged over the nine-day period February 11-19, 2020.  Visit https://www.cpc.ncep.noaa.gov/ to view the outlooks.

ENSEMBLE RIVER FORECASTS - SOME THREAT OF RIVER FLOODING DEVELOPING 
DURING THE NEXT FEW DAYS

The most recent runs (February 5, 2020) of the short-term (one week) ensemble river forecasts, which take into account anticipated future weather conditions including precipitation and temperatures, show some threat of river flooding developing as a result of the predicted rain event during the next two days.  The threat is mostly across southern and eastern areas, where the axis of heaviest rain is currently predicted.  Please visit https://www.weather.gov/erh/mmefs.

SUMMARY

Some river flooding is possible during the next few days across mainly southern and eastern areas as a result of heavy rainfall expected during the next two days.  As such, the river flood potential for the next two weeks is above average for early February across roughly the southeastern half of the MARFC region.  Elsewhere 
snow and river ice conditions remain minimal in terms of contributing to river flood potential, except for a portion of the Susquehanna Basin in NY.  Beyond the next few days, the predicted weather pattern suggests additional moderate-heavy precipitation events are possible.  Please monitor weather and river forecasts through this weekend.

WATER SUPPLY OUTLOOK 

According to the latest (January 30, 2020) U.S. Drought monitor (https://droughtmonitor.unl.edu), a small area of abnormally dry conditions remains across a portion of the Delmarva Peninsula. Please visit https://www.drought.gov, https://www.cpc.ncep.noaa.gov and https://www.weather.gov/marfc/wro_north for additional drought and water supply information.  Assuming near-normal precipitation for the next few months, no water supply shortages are anticipated anywhere within the MARFC region through April, 2020.

Please visit the NWS MARFC homepage at https://www.weather.gov/marfc or find us on Facebook at https://www.facebook.com/NWSMARFC and on Twitter @nwsmarfc.

The next outlook will be issued in two weeks, on or about February 19-20, 2020.

SK
 

Winter/Spring River Flood Potential Outlook
NWS Middle Atlantic River Forecast Center (MARFC)
State College, PA
10:00am EST Thu, Jan 23, 2020

Outlook Number 20-02 - January 23, 2020


This Winter/Spring River Flood Potential Outlook is valid for the two-week period January 23-February 6, 2020.

This outlook estimates the potential for river flooding (not flash flooding) to develop during the next two weeks across the Middle Atlantic River Forecast Center`s (MARFC) area of responsibility based on a current assessment of hydrometeorological factors which can contribute to river flooding. Across the MARFC area these factors include future weather conditions, recent precipitation, soil moisture, snow cover and snow water equivalent, river ice, streamflow, and others. This outlook does not address the severity/extent of any future river flooding.

Remember, in the Mid-Atlantic region heavy rainfall is the primary factor which leads to river flooding. Heavy rainfall can rapidly cause river flooding any time of the year, even when overall river flood potential is considered to be low or below average.

TWO-WEEK RIVER FLOOD POTENTIAL - NEAR AVERAGE

The river flood potential during the next two weeks (through February 6, 2020) is about average. Factors which contribute to this assessment of river flood potential are discussed below.

CURRENT RIVER FLOODING - NONE

There is currently no river flooding occurring within the MARFC service area.

RECENT PRECIPITATION - AVERAGE/BELOW AVERAGE

During the last 30 days (December 23, 2019 -, January 21, 2020) observed precipitation across the MARFC region has generally been in the average to below average range. Eastern PA, NJ and the Delmarva Peninsula have been the driest areas compared to normal. A few isolated locations in central VA have seen above average precipitation during the last 30 days. To view precipitation departure data please visit https://www.weather.gov/marfc/Precipitation_Departures.

SNOW CONDITIONS - BELOW AVERAGE/AVERAGE

Generally continuous snow covers the ground across roughly the northern half of the MARFC region as of this morning (January 23, 2020). The snow/no-snow line runs from the mountains of western MD east-northeastward across the northern third of NJ. However, the only snow of any hydrological significance within the MARFC service area is found across portions of central NY, where 2-7 inches covers the ground. The water contained in the snow in this area is in the 0.4-1.2 inch range, which is still below/much below normal for this area for mid-winter. In fact, similar to two weeks ago, snow conditions remain below average (in some areas much-below average) for the date across about the northwestern half of the region, and about average elsewhere. Snow information can be found at https://www.weather.gov/marfc/Snow and https://www.nohrsc.noaa.gov.

RIVER ICE - BELOW AVERAGE/AVERAGE

Currently, river ice within the MARFC service area is not as extensive or as thick as usual for the date. Though there is some river ice, conditions are below average (in some areas much-below average) for roughly the northwestern half of the region, and about average for the southeastern half. The current river ice conditions are not significant in terms of contributing to river flood potential, and weather conditions for the next two weeks suggest river ice conditions will remain rather limited.

STREAMFLOW CONDITIONS - VARIABLE

The latest data from the United States Geological Survey (USGS) indicates streamflow conditions are still somewhat above median across NY and portions of PA, but median/below median elsewhere. For current streamflow conditions please visit https://waterdata.usgs.gov/nwis/rt.

SOIL MOISTURE CONDITIONS - VARIABLE

The long-term Palmer drought severity index is useful to estimate deep soil moisture conditions. The January 18, 2020 chart (seen at https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/regional_monitoring/palmer.gif) suggests deep soils are unusually moist to extremely moist across portions of NY and PA. Elsewhere, the index map shows near-normal to below-normal values. Additional soil moisture data confirms an area of somewhat wet soils in NY, but also suggests that soils have been slowly drying. Go to https://www.cpc.ncep.noaa.gov/products/Soilmst_Monitoring/ and then click on U.S. Monitoring to view this soil moisture information.

GROUNDWATER - NEAR NORMAL

Within the MARFC service area, real-time USGS groundwater monitoring wells continue to indicate groundwater levels are generally fairly close to normal for this time of year. Please visit https://groundwaterwatch.usgs.gov.

RESERVOIR CONDITIONS - AVERAGE/ABOVE AVERAGE

Most major reservoirs within the MARFC region are holding storages that are average to somewhat above average for this time of year.

FUTURE WEATHER CONDITIONS - WEEKEND STORM SYSTEM

One storm system brings moderate-heavy precipitation to the region this weekend. Rain of 0.5-2.0 inches is possible across the southern half of the region with mixed precipitation likely across the north. At this time river flooding is not anticipated as a result of this weekend`s storm, though significant rises are possible. Another storm impacts the region toward the end of next week. Presently this second storm looks a little colder and could bring frozen precipitation to more of the MARFC service area. Temperatures generally look pretty close to seasonable during the next two weeks. The latest (January 22, 2020) longer-range weather outlooks issued by the NWS Climate Prediction Center suggest both temperatures and precipitation will be above normal for most of the MARFC region when averaged over the nine-day period January 8 - February 5, 2020. Visit https://www.cpc.ncep.noaa.gov/ to view the outlooks.

ENSEMBLE RIVER FORECASTS - A LIMITED THREAT OF SCATTERED RIVER FLOODING DEVELOPING DURING THE NEXT FEW DAYS

The most recent runs (January 22, 2020) of the short-term (one week) ensemble river forecasts, which take into account anticipated future weather conditions including precipitation and temperatures, show a limited threat of scattered river flooding developing as a result of the precipitation event (and possible snowmelt) this weekend. Moderate-heavy rain is possible, mainly across southern and eastern areas, where up to 2.0 inches of rain is possible. Heavier than anticipated rain of 3 inches or more could cause river flooding to develop. Further north, a warmer and wetter weekend storm than currently expected could lead to scattered river flooding there as well. Please visit https://www.weather.gov/erh/mmefs for short-term ensemble river forecasts.

SUMMARY

The risk of river flooding during the next two weeks for streams and rivers within the MARFC service area is near average. Snow and river ice conditions generally remain minimal in terms of contributing to river flood potential, except for a portion of the Susquehanna Basin in NY. However a moderate-heavy precipitation event is currently anticipated this weekend, with the heaviest rains expected across southern and eastern portions of the region and mixed precipitation across the north. While no river flooding is currently expected to develop from this event, please monitor weather and river forecasts through this weekend.

WATER SUPPLY OUTLOOK

According to the latest (January 23, 2020) U.S. Drought monitor (https://droughtmonitor.unl.edu), a small area of abnormally dry conditions remains across a portion of the Delmarva Peninsula. Visit https://www.drought.gov, https://www.cpc.ncep.noaa.gov and https://www.weather.gov/marfc/wro_north for additional drought and water supply information. Assuming near-normal precipitation for the next few months, no water supply shortages are anticipated anywhere within the MARFC region through mid-April, 2020.

Please visit the NWS MARFC homepage at https://www.weather.gov/marfc or find us on Facebook at https://www.facebook.com/nwsmarfc/?REF=aymt_homepage_panel and on Twitter @nwsmarfc.

The next outlook will be issued in two weeks, on or about February 5-6, 2020.

SK

Winter/Spring River Flood Potential Outlook
NWS Middle Atlantic River Forecast Center (MARFC)
State College, PA
3:35pm EST Wed, Jan 8, 2020

Outlook Number 20-01 - January 8, 2020


This Winter/Spring River Flood Potential Outlook is valid for the two-week period January 9-23, 2020.

This outlook estimates the potential for river flooding (not flash flooding) to develop during the next two weeks across the Middle Atlantic River Forecast Center`s (MARFC) area of responsibility (Mid- Atlantic Region) based on a current assessment of hydrometeorological factors which can contribute to river flooding. Across the MARFC area these factors include future weather conditions, recent precipitation, soil moisture, snow cover and snow water equivalent, river ice, streamflow, and others. This outlook does not address the severity/extent of any future river flooding.

Remember, in the Mid-Atlantic region heavy rainfall is the primary factor which leads to river flooding. Heavy rainfall can rapidly cause river flooding any time of the year, even when overall river flood potential is considered to be low or below average.

TWO-WEEK RIVER FLOOD POTENTIAL - AVERAGE

The river flood potential during the next two weeks (through January 23, 2020) is about average. Factors which contribute to this assessment of river flood potential are discussed below.

CURRENT RIVER FLOODING - NONE

There is currently no river flooding occurring within the MARFC service area.

RECENT PRECIPITATION - VARIABLE

During the last 30 days (December 9, 2019 - January 7, 2020) observed precipitation has been rather variable across the MARFC region, but fairly close to normal for most of the area. Exceptions include portions of southwestern PA and much of NJ which have been somewhat wetter than normal. To view precipitation departure data please visit https://www.weather.gov/marfc/Precipitation_Departures.

SNOW CONDITIONS - BELOW AVERAGE/AVERAGE

While much of the MARFC region has snow on the ground as of this morning (January 8, 2020), all of the snow is essentially insignificant hydrologically. Within the MARFC service area, there is little/no snow across southeast VA, the Delmarva region, and along coastal NJ. This is normal or about average. Otherwise, generally 1-5 inches of snow covers the ground, with a few locally greater depths. The water equivalent of the snow is mostly less than a half inch, again except for a few locally higher amounts. Snow conditions are below average (in some areas much-below average) for the date across about the northwestern half of the region, and about average elsewhere. Even if all the snow melted in a short time frame, the snow is currently not a significant factor in terms of its ability to produce river flooding. Snow information can be found at https://www.weather.gov/marfc/Snow and https://www.nohrsc.noaa.gov.

RIVER ICE - BELOW AVERAGE/AVERAGE

Very little river ice currently exists within the MARFC service area. This is below average for roughly the northwestern half of the region, and about average for the southeastern half.

STREAMFLOW CONDITIONS - VARIABLE

The latest data from the United States Geological Survey (USGS) indicates streamflow conditions are somewhat above median across NY and portions of PA, then gradually decrease to average/below average heading south into VA. For current streamflow conditions please visit https://waterdata.usgs.gov/nwis/rt.

SOIL MOISTURE CONDITIONS - VARIABLE

The long-term Palmer drought severity index is useful to estimate deep soil moisture conditions. The January 4, 2020 chart (found at https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/regional_ monitoring/palmer.gif) suggests deep soils are unusually moist to extremely moist across much of NY, PA and northern NJ. Further south, the index suggests near normal to somewhat below normal values across VA and the Delmarva region. Additional more detailed soil moisture information also suggests that soils are somewhat wetter than normal across portions of NY and northern PA, while soils gradually dry heading south. Soils in MD, VA and DE are drier than normal for the date. Go to https://www.cpc.ncep.noaa.gov/products/Soilmst_Monitoring/ and then click on U.S. Monitoring to view this soil moisture information.

GROUNDWATER - NEAR NORMAL

Within the MARFC service area, real-time USGS groundwater monitoring wells indicate groundwater levels are generally fairly close to normal. Please visit https://groundwaterwatch.usgs.gov.

RESERVOIR CONDITIONS - AVERAGE/ABOVE AVERAGE

Most major reservoirs within the MARFC region are holding storages that are average to somewhat above average for this time of year.

FUTURE WEATHER CONDITIONS - MODERATE RAIN EVENT THIS WEEKEND

After a seasonably chilly start, another warm up quickly begins in what has thus far been a rather mild winter. By Saturday, January 11, temperatures are currently predicted to range from the mid-50s in NY to the mid-70s in southeast VA. This will effectively melt nearly all of the snow on the ground within the MARFC region. Periods of rain will accompany the mild temperatures this weekend. Presently moderate rainfall is anticipated, with amounts generally in the 0.25-1.00 inch range ending Sunday. However, it is worth mentioning that there is a limited risk that heavy rain (1-2 inches) could fall across portions of NY and PA this weekend. Additional light-moderate rain is possible around next Tuesday. Then a trend toward cooler and drier weather later next week. The latest (January 8, 2020) longer-range weather outlooks issued by the NWS Climate Prediction Center suggest both temperatures and precipitation will be above normal for most of the MARFC region when averaged over the nine-day period January 14-22, 2020. Visit https://www.cpc.ncep.noaa.gov/ to view the outlooks.

ENSEMBLE RIVER FORECASTS - A LIMITED THREAT OF RIVER FLOODING DEVELOPING MAINLY IN NY DURING THE NEXT FEW DAYS

The most recent runs (January 8, 2019) of the short-term (one week) ensemble river forecasts, which take into account anticipated future weather conditions including precipitation and temperatures, show a limited threat of scattered river flooding developing as a result of the rain event this weekend. While current information suggests this will be a moderate rain event, there are some models that are indicating heavier rains for portions of NY and PA, which if realized could produce some river flooding. As such rainfall forecasts for the weekend event should be monitored during the next few days. Please visit https://www.weather.gov/erh/mmefs for short- term ensemble river forecasts.

SUMMARY

The risk of river flooding during the next two weeks for streams and rivers within the MARFC service area is near average. Snow and river ice conditions are essentially insignificant currently in terms of contributing to river flood potential. However a moderate rain event is currently anticipated this weekend, with the heaviest rains expected across the northern half of the region. While no river flooding is currently expected to develop from this event, rainfall forecasts should be monitored since some models are suggesting heavier rain of 1-2.5 inches could fall this weekend.

WATER SUPPLY OUTLOOK

According to the latest (January 2, 2020) U.S. Drought monitor (https://droughtmonitor.unl.edu), a small area of abnormally dry conditions exists across a portion of the Delmarva Peninsula. Visit https://www.drought.gov, https://www.cpc.ncep.noaa.gov and https://www.weather.gov/marfc/wro_north for additional drought and water supply information. Assuming near-normal precipitation for the next few months, no water supply shortages are anticipated anywhere within the MARFC region through April, 2020.

Please visit the NWS MARFC homepage at https://www.weather.gov/marfc or find us on Facebook at https://www.facebook.com/nwsmarfc/?REF=aymt_homepage_panel and on Twitter@nwsmarfc.

The next outlook will be issued in two weeks, on or about January 22-23, 2020.

SK