National Weather Service United States Department of Commerce

Outlook #1 - January 5, 2017 Outlook #4 - February 16, 2017
Outlook #2 - January 18, 2017 Outlook #5 - March 2, 2017
Outlook #3 - February 2, 2017 Outlook #6 - March 15, 2017

 


 

FGUS61 KRHA 151727
ESGRHA

WINTER/SPRING RIVER FLOOD POTENTIAL OUTLOOK
MIDDLE ATLANTIC RIVER FORECAST CENTER
NATIONAL WEATHER SERVICE STATE COLLEGE, PA
125 PM EDT THU MAR 15 2017

OUTLOOK NUMBER 17-06 - MARCH 15, 2017

THIS WINTER/SPRING RIVER FLOOD POTENTIAL OUTLOOK IS VALID FOR THE 
TWO-WEEK PERIOD MARCH 15-30, 2017.

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 - THE RIVER FLOOD POTENTIAL FOR MARFC
RIVERS DURING THE NEXT TWO WEEKS IS NEAR AVERAGE ACROSS THE NORTHERN HALF
OF THE REGION, AND BELOW AVERAGE ACROSSS THE SOUTHERN HALF. Factors which
contribute to this assessment of river flood potential are discussed in
some detail below.

CURRENT FLOODING - NONE.

RECENT PRECIPITATION - VARIABLE. 
During the last 30 days (February 13-March 14, 2017) precipitation
(liquid equivalent) was below normal to much-below normal across much of
the MARFC service area. Some areas did receive normal/above normal
precipitation, mainly in a zone from western MD/northeastern WV
northeastward through central and northeastern PA and into northern NJ
and southeastern NY.
 
SNOW CONDITIONS - AVERAGE TO ABOVE AVERAGE.  
Due to the recent major storm, snow now covers approximately the
northwestern three-quarters of the MARFC region.  Snow depths range from
less than an inch near the southern edge of the snowpack to nearly three
feet at a few locations in NY.  Much of the northern half of the MARFC
service area has snow depths of 8-24 inches.  Snow water equivalent
values range from a few tenths of an inch across the southern edge of the
snowpack, to around 3 inches in portions of NY state and northeast PA.
Much of the northern half of the region has values in the 1.0-2.5 inch
range.  Snow conditions are currently considered average to above average
for mid-March.  Snow information can be found by visiting
www.weather.gov/marfc/snow and www.nohrsc.noaa.gov.

RIVER ICE - ABOUT AVERAGE.  
The unusually cold weather recently has allowed some river ice to reform,
mainly across the northern half of the region.  This is rare for mid
March.  Even so, the river ice is not particularly thick or extensive.
Some additional river ice formation may occur for about the next week or
so.  Still, river ice conditions are, and should remain, about average
for late winter.

STREAMFLOW CONDITIONS - VARIABLE.  
The latest data from the United States Geological Survey (USGS) indicates
above-average streamflows in and around the Delmarva Peninsula/southern
NJ due to recent rainfall.  Elsewhere streamflows are generally below or
even much-below normal for mid-march.  Streamflows are expected to
eventually rise during this two-week period once snowmelt begins.  Please
visit the USGS web pages at www.usgs.gov/water for current streamflow
data.

SOIL MOISTURE CONDITIONS - NORMAL TO MUCH BELOW NORMAL.  
The long-term Palmer Drought Severity Index is used to infer deep soil
moisture conditions.  The March 11, 2017 chart (found at
www.cpc.ncep.noaa.gov/products/analysis_monitoring/regional_monitoring/palmer.gif) 
suggests deep soils across much of the MARFC service area contain
moisture that is fairly close to normal for this time of year.  However,
other detailed soil moisture information (go to
www.cpc.ncep.noaa.gov/products/Soilmst_Monitoring and then click on U.S.
monitoring) shows considerable soil moisture deficits remain across large
portions of the MARFC region, especially eastern and southern regions.

GROUNDWATER - VARIABLE.  
Most USGS groundwater monitoring wells across the southeastern half of
the MARFC region are currently indicating groundwater levels that are
below or much-below their long-term normals for this time of year.
Elsewhere groundwater levels are closer to normal.  Please visit
https://groundwaterwatch.usgs.gov.

RESERVOIR CONDITIONS - BELOW AVERAGE TO AVERAGE.  
Most major reservoirs within the MARFC region are holding storages that
are below average/average for this time of year.  Reservoir storage in
the upper Delaware River basin has now improved to long-term median
levels, with significant snowmelt still to come.

FUTURE WEATHER CONDITIONS
Continued below-average temperatures and generally only light-moderate
precipitation events are expected during about the first week of this
two-week outlook period.  At this time there are no strong indications of
any widespread heavy rain events, or rapid snowmelt events, for about the
next week. Longer-range weather outlooks suggest temperatures will get
closer to normal, while precipitation may be normal or above normal
during the second week of this outlook period.

ENSEMBLE RIVER FORECASTS - NO THREAT OF RIVER FLOODING DEVELOPING.
The most recent runs (March 15, 2017) of the ensemble river forecasts
show no river flooding developing within the MARFC region for about the
next week.  This is due to currently anticipated future weather
conditions which do not indicate a lot of snowmelt nor widespread heavy
rainfall for about the next week.  Please visit www.weather.gov/erh/mmefs
for ensemble river forecasts.

AHPS RIVER FORECASTS - NEAR TO BELOW NORMAL.  
The Advanced Hydrologic Prediction Service (AHPS) generates long-term (14
days or greater) probabilistic river forecasts based on current basin
conditions (river levels, soil moisture, extent and condition of any
snowpack) along with 50 years of historic temperature and precipitation
data.  However, it is important to note that AHPS river forecasts do not
take into account actual future weather conditions whereas ensemble river
forecasts (see previous section) do.  For this outlook period (through
March 30, 2017) current AHPS river forecasts indicate a below-normal
chance of river flooding across the south with a near-normal chance
across the north.
 
SUMMARY - FOR THE NEXT TWO WEEKS THE RIVER FLOOD POTENTIAL FOR 
RIVERS IN THE MARFC REGION IS ABOUT AVERAGE ACROSS THE NORTH AND BELOW
AVERAGE ACROSS THE SOUTH.  AT THIS TIME NO WIDESPREAD SIGNIFICANT RAIN OR
RAPID SNOWMELT EVENTS ARE INDICATED FOR ABOUT THE NEXT WEEK.

WATER SUPPLY OUTLOOK  
According to the latest (March 7, 2017) U.S. drought monitor
(http://droughtmonitor.unl.edu), large portions of the MARFC service area
continue to show conditions that range from abnormally dry to severe
drought.  Driest regions are across the south and east.  The recent storm
did provide meaningful precipitation across eastern portions of the MARFC
area, which will help diminish the dryness some.  Still additional above
average precipitation would be beneficial across the east and especially
the south to prevent more serious problems from developing this spring
and summer.  Visit www.drought.gov, www.cpc.ncep.noaa.gov and
www.weather.gov/marfc/wro_update for additional drought and water supply
information.

Please visit the NWS MARFC homepage at www.weather.gov/marfc or find us
on facebook at www.facebook.com/NWSMARFC and on twitter @NWSMARFC.

THE NEXT WINTER/SPRING FLOOD OUTLOOK WILL BE ISSUED BY THIS OFFICE ON
MARCH 30, 2017.

SK
$$


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FGUS61 KRHA 021721
ESGRHA

WINTER/SPRING RIVER FLOOD POTENTIAL OUTLOOK
MIDDLE ATLANTIC RIVER FORECAST CENTER
NATIONAL WEATHER SERVICE STATE COLLEGE, PA
1220 PM EST THU MAR 2 2017

OUTLOOK NUMBER 17-05 - MARCH 2, 2017

THIS WINTER/SPRING RIVER FLOOD POTENTIAL OUTLOOK IS VALID FOR THE TWO-WEEK PERIOD MARCH 2-16, 2017.

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 - THE RIVER FLOOD POTENTIAL FOR MARFC RIVERS IS
BELOW AVERAGE.  Factors which contribute to this assessment of river flood
potential are discussed in some detail below.

CURRENT FLOODING - NONE.

Recent precipitation - below to much-below normal except across northern PA and NY.
During the last 30 days (January 31-March 1, 2017) precipitation (liquid 
equivalent) was below normal to very-much-below normal across most of the MARFC 
service area.  Only northern PA and NY observed precipitation that was normal to 
above normal.  Va, central and eastern MD, southern DE and southern NJ was very dry
with only 0.5-1.5 inches of precipitation falling. Central portions of the region 
did a bit better with 1.0-2.5 inches, while northern PA and NY received 2.5-3.5
inches.  Much of the southern half of the MARFC region received less than half the
normal precipitation during the last 30 days.  Please visit www.weather.gov/marfc,
then click on water supply and then on departures from average.

SNOW CONDITIONS - AVERAGE TO MUCH-BELOW AVERAGE.  
Currently within the MARFC region there is no significant snow cover.  Across about
the northwest half of the MARFC region, current snow conditions are below average 
to much-below average.  It is most interesting to note that all significant snow
has now melted across this region that normally contains quite a bit of snow at
this time of year.  Of course more snow will most likely fall in this region
during March. Across about the southeast half, where snow on the ground is much 
less common, the current lack of snow is typical or about average. Snow information
can be found by visiting www.weather.gov/marfc/snow and www.nohrsc.noaa.gov.

RIVER ICE - AVERAGE TO MUCH-BELOW AVERAGE.  
Currently there is no river ice on/in aNY MARFC rivers.  This is unusual for early
March for much of the Susquehanna and Delaware river basins.  For most other MARFC
rivers a lack of river ice in early March is somewhat more typical.  It is now too
late in winter for widespread significant river ice formation. 

STREAMFLOW CONDITIONS - VARIABLE.  
The latest data from the united states geological survey (USGS) indicate
streamgages across about the northwestern third of the MARFC service area are
showing streamflows that are near-to-above median for early March.  For the
remainder of the service area streamflows are below to much-below median for the 
date.  Please visit the USGS web pages at www.usgs.gov/water for streamflow data.

SOIL MOISTURE CONDITIONS - NORMAL TO MUCH BELOW NORMAL.  
The long-term palmer drought severity index is used to infer deep soil moisture
conditions.  The February 25, 2017 chart (found at
www.cpc.ncep.noaa.gov/products/analysis_monitoring/regional_monitoring/palmer.gif)
suggests deep soils across much of the MARFC service area contain moisture that is
fairly close to normal for this time of year.  However, other detailed soil
moisture information (go to www.cpc.ncep.noaa.gov/products/Soilmst_Monitoring and 
then click on US Monitoring) shows considerable soil moisture deficits remain
across large portions of the MARFC region, especially eastern and southern regions. 

GROUNDWATER - VARIABLE.  
Most USGS groundwater monitoring wells across the southeastern half of the MARFC 
region are currently indicating groundwater levels that are below or much-below 
their long-term normals for this time of year.  Elsewhere groundwater levels are 
closer to normal.  Please visit https://groundwaterwatch.usgs.gov.

RESERVOIR CONDITIONS - BELOW AVERAGE TO AVERAGE.  
Most major reservoirs within the MARFC region are holding storages that are below
average/average for this time of year.  Reservoir storage in the upper Delaware
River basin is currently still considerably below the long-term median but
continues to slowly improve.  Again it is interesting to observe that all
significant snow has for the time being melted in those areas that normally
contain quite a bit of snow at this time of winter.

FUTURE WEATHER CONDITIONS 
Relatively tranquil weather conditions are anticipated for most of the MARFC region
for about the next week.  The weather pattern during the next week will feature,
as it has recently, wide swings in temperatures but generally only light to
moderate precipitation.  At the present there are no strong indications of any 
widespread major rain or snow events for about the next week.

ENSEMBLE RIVER FORECASTS - A MINIMAL THREAT OF RIVER FLOODING DEVELOPING.  
The most recent runs (March 2, 2017) of the ensemble river forecasts show only an
isolated threat of river flooding developing in NY around March 8, 2017.  Please
visit www.weather.gov/erh/mmefs for ensemble river forecasts.

AHPS RIVER FORECASTS - GENERALLY BELOW NORMAL.  
The Advanced Hydrologic Prediction Service (AHPS) generates long-term (14 days or
greater) probabilistic river forecasts based on current basin conditions (river
levels, soil moisture, extent and condition of any snowpack) along with 50 years
of historic temperature and precipitation data.  However, it is important to note
that AHPS river forecasts do not take into account actual future weather
conditions whereas ensemble river forecasts (see previous section) do.  For this
outlook period (through March 16, 2017) current AHPS river forecasts indicate a
below-normal chance of river flooding for most MARFC rivers, due primarily to the 
lack of significant snow conditions and/or low streamflows.

SUMMARY - THE RIVER FLOOD POTENTIAL FOR RIVERS IN THE MARFC REGION IS BELOW AVERAGE FOR THE NEXT TWO WEEKS.  Heavy rainfall would be required to cause river flooding.
At this time no widespread significant rain or snow events are indicated for about
the next week.

WATER SUPPLY OUTLOOK 
According to the latest (February 28, 2017) US Drought Monitor (http://droughtmonitor.unl.edu), large portions of the MARFC service area continue to show conditions that range from abnormally dry to severe drought.  In a change from recent drought outlooks, the most recent outlook now suggests the dry conditions may persist and/or expand into the spring months, especially across eastern and southern portions of the MARFC region. So far only isolated and generally low-impact water supply issues have been noted in association with the dry conditions.  With the current combination of minimal snow, dry soils and below median streamflows affecting much of the MARFC region, conditions will need to be monitored during the next weeks/months for the potential development of more significant water supply problems.  Many regions now need above-average precipitation to ward off more serious problems from developing this spring and summer.  Visit www.drought.gov, www.cpc.ncep.noaa.gov and www.weather.gov/marfc/wro_update for additional drought and water supply information.

Please visit the nws MARFC homepage at www.weather.gov/marfc or find us on facebook at www.facebook.com/NWSMARFC and on twitter @NWSMARFC.

The next winter/spring flood outlook will be issued by this office in two weeks on March 16, 2017.

SK
$$

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FGUS61 KRHA 161856
ESGRHA

WINTER/SPRING RIVER FLOOD POTENTIAL OUTLOOK
MIDDLE ATLANTIC RIVER FORECAST CENTER
NATIONAL WEATHER SERVICE STATE COLLEGE, PA
155 PM EST THU FEB 16, 2017

OUTLOOK NUMBER 17-04 - FEBRUARY 16, 2017

THIS FOURTH WINTER/SPRING RIVER FLOOD POTENTIAL OUTLOOK IS VALID 
FOR THE TWO-WEEK PERIOD FEBRUARY 16-MARCH 2, 2017.

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 - GENERALLY BELOW AVERAGE.
The river flood potential for MARFC rivers is generally below average for the first
week of this outlook period, through about February 23, 2017.  During the second week
of this outlook period the river flood potential increases to average. Factors which
contribute to this assessment of river flood potential are discussed in some detail
below.

CURRENT FLOODING - NONE.

RECENT PRECIPITATION - VARIABLE.  
During the last 30 days (January 16-february 14, 2017) precipitation (liquid
equivalent) was below to much-below average across much of VA northeastward through the
Chesapeake Bay region and into southeast pa and southern NJ. Driest regions were in the
Chesapeake Bay region. Otherwise in all other areas precipitation was average to even
much-above average. Wettest areas included north-central pa and south-central NY.  Most
locations within the MARFC service area received 1.5-4.5 inches of precipitation (water
equivalent) which was 75 percent below normal in the Chesapeake Bay region and 60
percent above normal in north-central pa and south-central NY.  Please visit
www.weather.gov/MARFC, then click on Water Supply and then on Departures From Average.

SNOW CONDITIONS - AVERAGE TO MUCH-BELOW AVERAGE.  
Currently within the MARFC region fairly continuous snow covers the ground in NY,
across northern and northeastern pa, and across about the northern third of NJ.  There
is also a negligible snow cover in the higher elevations of southwest PA, western MD,
and northeastern WV.  The only region where the snow is deep enough and contains enough
water equivalent to be a factor in contributing to flood potential is across portions
of NY, northeastern pa and extreme northern portions of NJ.  This includes upper
portions of the Susquehanna basin, upper portions of the Delaware basin, and the
Passaic basin.  In this region snow depths range from 4-15 inches with isolated depths
to 20 inches.  Corresponding water equivalent values range from 1-3 inches with
isolated values to 3.5 inches.  These snow conditions are somewhat below average to
average for mid February in this region. Outside of this region snow conditions are
below to much-below average except across about the southeastern third of the MARFC
region where the current lack of snow is fairly typical or about average.  Weather
conditions during the next week are expected to be warm enough to gradually melt some
of the snowpack across northern pa, northern NJ and NY.  Snow information can be found
by visiting www.weather.gov/marfc/snow and www.nohrsc.noaa.gov.

RIVER ICE - AVERAGE TO MUCH-BELOW AVERAGE.  
Currently there is no significant river ice on/in any MARFC rivers.  This is rare for
mid February for most of the Susquehanna and Delaware River basins, as well as for
rivers in northern NJ.  For most other MARFC rivers a lack of river ice during the peak
winter period occurs more frequently but is still somewhat uncommon.  Based on current
weather predictions for the next two weeks, and the time of year, significant river ice
formation is unlikely during this next two-week period. 

STREAMFLOW CONDITIONS - VARIABLE.  
The latest data from the United States Geological Survey (USGS) indicate stream gages
across about the northwestern third of the service area are showing streamflows that
are above median for mid February.  Meanwhile across about the southeastern two-thirds
of the area streamflows are mostly below to much-below median for the date. Please
visit the USGS web pages at www.usgs.gov/water for streamflow data.

SOIL MOISTURE CONDITIONS - NORMAL TO BELOW NORMAL.  
The long-term palmer drought severity index is used to infer deep soil moisture
conditions.  The February 11, 2017 chart (found at
www.cpc.ncep.noaa.gov/products/analysis_monitoring/regional_monitoring/palmer.gif)
suggests deep soils across much of the MARFC service area contain moisture that is
fairly close to normal for this time of year. However, other soil moisture information
(go to www.cpc.ncep.noaa.gov/products/Soilmst_Monitoring and then click on U.S.
Monitoring) continues to show considerable soil moisture deficits remain across
portions of the MARFC region, especially eastern and southern portions.  This supports
the most recent version (February 14, 2017) of the U.S. Drought Monitor chart which
still shows large portions of the MARFC region experiencing abnormally dry to severe
drought conditions (http://droughtmonitor.unl.edu).

GROUNDWATER - GENERALLY NORMAL OR BELOW NORMAL.  
Many USGS groundwater monitoring wells across especially eastern and southern portions
of the MARFC region are currently indicating groundwater levels that are below or even
much-below their long-term normals for this time of year.  Still there are also some
wells scattered across the entire region with near-normal or even somewhat above-normal
water levels, with no real identifiable pattern.  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.  Reservoir storage in the upper Delaware River basin is
currently still considerably below the long-term median but continues to improve.

FUTURE WEATHER CONDITIONS -
The weather during the next week will likely feature temperatures warming to above
average readings over the upcoming weekend and beyond, and only periods of mostly light
precipitation.  The second week of this outlook period could produce a more active
weather pattern.  At this time there are no indications of any widespread heavy rain
(or snow) events for about the next week.

AHPS RIVER FORECASTS - NEAR NORMAL TO BELOW NORMAL.  
The Advanced Hydrologic Prediction Service (AHPS) generates long-term (14 days or
greater) probabilistic river forecasts based on current basin conditions (river levels,
soil moisture, extent and condition of any snowpack) along with 50 years of historic
temperature and precipitation data.  However, it is important to note that AHPS river
forecasts do not take into account actual future weather conditions whereas ensemble
river forecasts (see next section) do. For this outlook period (through march 2, 2017
current AHPS river forecasts indicate a near or below-normal chance of river flooding
for most MARFC rivers.

ENSEMBLE RIVER FORECASTS - A MINIMAL THREAT OF RIVER FLOODING DEVELOPING.
The most recent runs (February 16, 2017) of the ensemble river forecasts show only an
isolated threat of river flooding developing in NY during the next week.  This threat
is centered around February 21-22, 2017 and is mainly associated with a possible period
of prolonged snowmelt along with periods of mainly light/moderate rainfall.  Please
visit www.weather.gov/erh/mmefs for ensemble river forecasts.

SUMMARY - THE RIVER FLOOD POTENTIAL FOR RIVERS IN THE MARFC REGION IS GENERALLY BELOW
AVERAGE DURING THE FIRST WEEK OF THIS TWO-WEEK OUTLOOK PERIOD DUE TO EXPECTED TRANQUIL
WEATHER CONDITIONS AND A LACK OF WIDESPREAD HEAVY RAINFALL.  THE RIVER FLOOD POTENTIAL
DURING THE SECOND WEEK IS ABOUT AVERAGE AS A MORE ACTIVE WEATHER PATTERN IS EXPECTED.
Widespread heavy rainfall would be required to cause river flooding and at this time
there are no indications of any widespread heavy rainfall events for the next week.

WATER SUPPLY OUTLOOK -
According to the latest (February 14, 2017) U.S. Drought Monitor
(http://droughtmonitor.unl.edu), large portions of the MARFC service area continue to
show conditions that range from abnormally dry to severe drought.  Latest outlooks
suggest these dry conditions will persist but should also gradually diminish over the
course of the next few weeks/months.  So far only isolated and generally low-impact
water supply issues have been noted within the MARFC service area in association with
the dry conditions.  At this time, assuming near-normal precipitation during the next
few months, widespread water supply problems are not anticipated.  Visit
www.drought.gov, www.cpc.ncep.noaa.gov and www.weather.gov/marfc/WRO_Update for
additional drought and water supply information.

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

THE NEXT WINTER/SPRING FLOOD OUTLOOK WILL BE ISSUED BY THIS OFFICE
IN TWO WEEKS ON MARCH 2, 2017.

SK
$$

....END MARFC....

NNNN

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FGUS61 KRHA 021724
ESGRHA

WINTER/SPRING RIVER FLOOD POTENTIAL OUTLOOK
MIDDLE ATLANTIC RIVER FORECAST CENTER
NATIONAL WEATHER SERVICE STATE COLLEGE, PA
1220 PM EST THU FEB 2 2017

OUTLOOK NUMBER 17-03 - FEBRUARY 2, 2017

This winter/spring river flood potential outlook is valid for the 
Two-week period february 2-16, 2017.

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 - the river flood potential for MARFC 
rivers is about average for the first week of this outlook period, 
through February 9, 2017.  During the second week of this outlook 
period the river flood potential is below average/average.  Heavy 
rain would be required for river flooding to develop.  Factors which 
contribute to this assessment of river flood potential are discussed 
in some detail below.

CURRENT FLOODING - NONE.

RECENT PRECIPITATION - NEAR TO ABOVE NORMAL.  
During the last 30 days (January 3-February 1, 2017) precipitation 
(liquid equivalent) was generally in the near-normal to above-normal 
range. Most locations within the MARFC service area received 2.5-4.5 
inches of precipitation (water equivalent) which was 10 percent below 
normal to 60 percent above normal.  A few small areas received less 
than 2.5 inches during the last 30 days, while at the same time a few 
small areas received more than 4.5 inches.  Please visit 
www.weather.gov/marfc, then click on water supply and then on 
Departures from Average.

SNOW CONDITIONS - AVERAGE TO MUCH-BELOW AVERAGE.  
Currently within the MARFC region snow covers the ground from roughly 
Interstate 80 and northward, and in the higher elevations of southwest 
PA, western MD, and northeastern WV.  In this region snow depths range 
from 1-10 inches, with corresponding water equivalent values ranging 
from 0.1-1.6 inches.  The only areas where enough snow exists to be 
somewhat of a factor with respect to contributing to river flood potential 
is across north-central PA and the NY portion of the MARFC service area.  
Here, snow depths of a few inches are common and snow water equivalent 
values of 1.0-1.5 inches are found.  Across about the northwest half of 
the MARFC region, current snow conditions are below average to much-below 
average.  Across about the southeast half, where snow on the ground is 
much less common, the current lack of snow is fairly typical or about 
average.  Snow information can be found by visiting 
www.weather.gov/marfc/snow and www.nohrsc.noaa.gov.

RIVER ICE - AVERAGE TO MUCH-BELOW AVERAGE.  
Currently there is very little river ice on/in any MARFC rivers.  This is 
rare for early February for most of the Susquehanna and Delaware River 
basins, as well as for rivers in northern NJ.  For most other MARFC rivers, 
an absence of river ice during the peak winter period occurs more frequently 
but is still somewhat uncommon.  Only limited river ice formation is 
anticipated during this next two-week period, based on current long-range 
weather outlooks. 

STREAMFLOW CONDITIONS - VARIABLE.  
The latest data from the United States Geological Survey (USGS) indicate 
stream gages across northern and western portions of the service area are 
showing stream flows that are near-to-above median for early February. 
Meanwhile across southern and eastern portions of the area stream flows are 
mostly below to much-below median for the date.  Please visit the USGS web 
pages at www.usgs.gov/water for streamflow data.

SOIL MOISTURE CONDITIONS - NORMAL TO BELOW NORMAL.  
The long-term palmer drought severity index is used to infer deep soil moisture 
conditions.  The January 28, 2017 chart (found at 
www.cpc.ncep.noaa.gov/products/analysis_monitoring/regional_monitoring/palmer.gif) 
suggests deep soils across much of the MARFC service area contain moisture that 
is fairly close to normal for this time of year.  However, other soil moisture 
information (go to www.cpc.ncep.noaa.gov/products/Soilmst_Monitoring and then 
click on U.S. monitoring) shows considerable soil moisture deficits remain across 
portions of the MARFC region.  This supports the most recent version 
(January 31, 2017) of the U.S. Drought Monitor chart which still shows large 
portions of the MARFC region experiencing abnormally dry to severe drought 
conditions (http://droughtmonitor.unl.edu).

GROUNDWATER - VARIABLE.  
Many USGS groundwater monitoring wells across the MARFC region are currently 
indicating groundwater levels that are below or even much-below their long-term 
normals for this time of year.  There are some wells scattered across the region 
with near normal or even somewhat above normal water levels, with no identifiable 
pattern.  Visit https://groundwaterwatch.usgs.gov.

RESERVOIR CONDITIONS - BELOW AVERAGE TO AVERAGE.  
Most major reservoirs within the MARFC region are holding storages that are below 
average/average for this time of year.  Reservoir storage in the Upper Delaware 
River basin is currently considerably below the long-term median but continues to 
slowly improve.

FUTURE WEATHER CONDITIONS  
Relatively tranquil weather conditions are anticipated for most of the MARFC region 
until a possibly significant storm system impacts the area February 7-8, 2017.  
This storm could produce moderate to heavy precipitation over portions of the MARFC 
service area, much of which could be rain.  Milder air will accompany this system as 
it moves through midweek next week, followed by cold temperatures later next week.  
Milder air may then try to return following the late-week cold snap next week. The 
potential rain/snowmelt event of February 7-8 represents, at this time, the biggest 
threat for river flooding to develop within the MARFC region during the next two 
weeks and should be monitored. 

AHPS RIVER FORECASTS - NEAR NORMAL TO BELOW NORMAL.
The Advanced Hydrologic Prediction Service (AHPS) generates long-term (14 days or 
greater) probabilistic river forecasts based on current basin conditions (river 
levels, soil moisture, extent and condition of any snowpack) along with 50 years of 
historic temperature and precipitation data.  However, it is important to note that 
AHPS river forecasts do not take into account actual future weather conditions whereas 
ensemble river forecasts (see next section) do. For this outlook period (through 
February 16, 2017) current AHPS river forecasts indicate a near or somewhat below-
normal chance of river flooding for most MARFC rivers compared to what has occurred 
during this same time period historically.

ENSEMBLE RIVER FORECASTS - A MINIMAL THREAT OF RIVER FLOODING DEVELOPING. The most 
recent runs (February 2, 2017) of the ensemble river forecasts show only an isolated 
threat of river flooding developing in NY.  This threat is centered around February 7-8,
 2017 and is associated with a possible rain/snowmelt event in that timeframe.  Please 
visit www.weather.gov/erh/mmefs for ensemble river forecasts.

SUMMARY - THE RIVER FLOOD POTENTIAL FOR RIVERS IN THE MARFC REGION IS ABOUT AVERAGE 
DURING THE FIRST WEEK, AND BELOW AVERAGE TO AVERAGE THE SECOND WEEK.  
Heavy rainfall would be required to cause river flooding.  Some heavy rain is possible 
in the Tuesday-Wednesday time frame next week, February 7-8, 2017.  This rain/snowmelt 
event will need to be monitored, mainly for upper portions of the Susquehanna and Delaware 
River basins where the most snow is found.

WATER SUPPLY OUTLOOK -
According to the latest (January 31, 2017) U.S. Drought Donitor 
(http://droughtmonitor.unl.edu), large portions of the MARFC service area continue to 
show conditions that range from abnormally dry to severe drought.  Latest outlooks suggest 
these dry conditions may persist for a while longer but should continue to gradually 
diminish over the next few weeks.  So far only isolated and generally low-impact water 
supply issues have been noted within the MARFC service area in association with the dry 
conditions.  At this time, assuming near-normal precipitation during the next few months, 
no widespread water supply problems are anticipated.  Visit www.drought.gov, 
www.cpc.ncep.noaa.gov and www.weather.gov/marfc/wro_update for additional drought and water 
supply information.

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

THE NEXT WINTER/SPRING FLOOD OUTLOOK WILL BE ISSUED BY THIS OFFICE
IN TWO WEEKS ON FEBRUARY 16, 2017.

SK
$$

....END MARFC....

NNNN

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FGUS61 KRHA 181736
ESGRHA

WINTER/SPRING RIVER FLOOD POTENTIAL OUTLOOK
MIDDLE ATLANTIC RIVER FORECAST CENTER
NATIONAL WEATHER SERVICE STATE COLLEGE PA
1235 PM EST THU JAN 18 2017 

OUTLOOK NUMBER 17-02 - JANUARY 18, 2017

THIS WINTER/SPRING RIVER FLOOD POTENTIAL OUTLOOK IS VALID FOR THE
TWO-WEEK PERIOD JANUARY 19-FEBRUARY 2, 2017.

THIS OUTLOOK ESTIMATES THE POTENTIAL FOR RIVER FLOODING (NOT FLASH
FLOODING) TO DEVELOP DURING THE NEXT TWO WEEKS ACROSS THE 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 - THE RIVER FLOOD POTENTIAL FOR MARFC
RIVERS IS AVERAGE/ABOVE AVERAGE FOR THE FIRST WEEK OF THIS OUTLOOK
PERIOD, THROUGH JANUARY 26, 2017.  DURING THE SECOND WEEK OF THIS
OUTLOOK PERIOD THE RIVER FLOOD POTENTIAL DECREASES TO BELOW
AVERAGE/AVERAGE.  FACTORS WHICH CONTRIBUTE TO THIS ASSESSMENT OF
RIVER FLOOD POTENTIAL ARE DISCUSSED IN SOME DETAIL BELOW.

CURRENT FLOODING - NONE.

RECENT PRECIPITATION - GENERALLY BELOW NORMAL.  DURING THE LAST 30
DAYS (DECEMBER 19, 2016-JANUARY 17, 2017) PRECIPITATION (LIQUID
EQUIVALENT) WAS BELOW NORMAL ACROSS MUCH OF THE MARFC REGION.  THE
DRIEST REGIONS RELATIVE TO NORMAL INCLUDED PORTIONS OF SOUTHEASTERN
NY, CENTRAL/EASTERN PA, NJ, DE, CENTRAL/EASTERN MD, PORTIONS OF
EASTERN WV AND CENTRAL/NORTHERN VA.  THESE AREAS RECEIVED 1.5-3.0
INCHES OF PRECIPITATION (WATER EQUIVALENT), WHICH WAS 10-50 PERCENT
BELOW NORMAL.  NEAR-NORMAL OR SOMEWHAT ABOVE-NORMAL PRECIPITATION
WAS OBSERVED ELSEWHERE, WITH AMOUNTS OF 2.0-4.5 INCHES WHICH WAS
ABOUT 10 PERCENT BELOW NORMAL TO ABOUT 30 PERCENT ABOVE.  PLEASE
VISIT www.weather.gov/marfc, THEN CLICK ON WATER SUPPLY AND THEN ON
DEPARTURES FROM AVERAGE.

SNOW CONDITIONS - AVERAGE TO MUCH-BELOW AVERAGE.  CURRENTLY SNOW
CONDITIONS WITHIN THE MARFC SERVICE AREA ARE ESSENTIALLY
INSIGNIFICANT IN TERMS OF BEING A FACTOR CONTRIBUTING TO RIVER FLOOD
POTENTIAL.  SNOW IS GENERALLY CONFINED TO THE HIGHER ELEVATIONS OF
NY AND IS PATCHY IN NATURE.  FOR ABOUT THE NORTHWEST HALF OF THE
MARFC REGION, CURRENT SNOW CONDITIONS ARE BELOW AVERAGE TO MUCH-
BELOW AVERAGE.  ACROSS ABOUT THE SOUTHEAST HALF, WHERE SNOW ON THE
GROUND IS MUCH LESS COMMON, THE CURRENT LACK OF SNOW IS FAIRLY
TYPICAL.  SNOW INFORMATION CAN BE FOUND BY VISITING
www.weather.gov/marfc/Snow AND www.nohrsc.noaa.gov.

RIVER ICE - AVERAGE TO MUCH-BELOW AVERAGE.  ALTHOUGH THERE HAS BEEN
SOME RIVER ICE THIS WINTER, CURRENTLY LITTLE IF ANY RIVER ICE IS
FOUND ON/IN MARFC RIVERS.  THIS IS QUITE UNUSUAL FOR MID JANUARY FOR
MOST OF THE SUSQUEHANNA AND DELAWARE RIVER BASINS, BUT IS NOT
UNCOMMON FOR MOST OTHER MARFC RIVER BASINS.  NO RIVER ICE FORMATION
IS EXPECTED DURING ABOUT THE FIRST WEEK OF THIS OUTLOOK PERIOD,
THROUGH AT LEAST JANUARY 25.

STREAMFLOW CONDITIONS - VARIABLE.  THE LATEST DATA FROM THE UNITED
STATES GEOLOGICAL SURVEY (USGS) INDICATE STREAMGAGES ACROSS ABOUT
THE NORTHERN HALF OF THE MARFC SERVICE AREA ARE SHOWING STREAMFLOWS
THAT ARE NEAR-TO-ABOVE MEDIAN FOR MID JANUARY DUE TO THE RECENT RAIN
EVENT.  ACROSS THE SOUTH STREAMFLOWS ARE NEAR-TO-BELOW MEDIAN.
PLEASE VISIT THE USGS WEB PAGES AT www.usgs.gov/water FOR STREAMFLOW
DATA.

SOIL MOISTURE CONDITIONS - NORMAL TO BELOW NORMAL.  THE LONG-TERM
PALMER DROUGHT SEVERITY INDEX IS USED TO INFER DEEP SOIL MOISTURE
CONDITIONS.  THE JANUARY 14, 2017 CHART (FOUND AT
www.cpc.ncep.noaa.gov/products/analysis_monitoring/
regional_monitoring/palmer.gif) SUGGESTS DEEP SOILS ACROSS MUCH OF
THE MARFC SERVICE AREA CONTAIN MOISTURE THAT IS FAIRLY CLOSE TO
NORMAL FOR THIS TIME OF YEAR.  HOWEVER, OTHER SOIL MOISTURE
INFORMATION (GO TO www.cpc.ncep.noaa.gov/products/Soilmst_Monitoring
AND THEN CLICK ON THEN CLICK ON U.S. MONITORING) SHOWS CONSIDERABLE
SOIL MOISTURE DEFICITS REMAIN ACROSS LARGE PORTIONS OF THE MARFC
REGION.  THIS SUPPORTS THE MOST RECENT VERSION (JANUARY 10, 2017) OF
THE U.S. DROUGHT MONITOR CHART WHICH STILL SHOWS LARGE PORTIONS OF
THE MARFC REGION EXPERIENCING ABNORMALLY DRY TO SEVERE DROUGHT
CONDITIONS (http://droughtmonitor.unl.edu).

GROUNDWATER - VARIABLE.  MANY USGS GROUNDWATER MONITORING WELLS
ACROSS THE MARFC REGION ARE CURRENTLY INDICATING GROUNDWATER LEVELS
THAT ARE BELOW OR EVEN MUCH-BELOW THEIR LONG-TERM NORMALS FOR THIS
TIME OF YEAR.  THERE ARE SOME WELLS SCATTERED ACROSS THE REGION WITH
NEAR NORMAL OR EVEN SOMEWHAT ABOVE-NORMAL WATER LEVELS, WITH NO
IDENTIFIABLE PATTERN.  VISIT https://groundwaterwatch.usgs.gov.

RESERVOIR CONDITIONS - BELOW AVERAGE TO AVERAGE.  MOST MAJOR
RESERVOIRS WITHIN THE MARFC REGION ARE HOLDING STORAGES THAT ARE
BELOW AVERAGE/AVERAGE FOR THIS TIME OF YEAR.  RESERVOIR STORAGE IN
THE UPPER DELAWARE RIVER BASIN IS CURRENTLY CONSIDERABLY BELOW THE
LONG-TERM MEDIAN BUT CONTINUES TO SLOWLY IMPROVE.

FUTURE WEATHER CONDITIONS - ABOVE AVERAGE TEMPERATURES WITH LITTLE
CHANCE OF SNOW OR RIVER ICE FORMATION WILL CONTINUE FOR AT LEAST THE
NEXT WEEK FOLLOWED BY INCREASINGLY COLDER WEATHER THEREAFTER.  A
WIDESPREAD SIGNIFICANT RAIN EVENT IS POSSIBLE JANUARY 22-24, 2017.
THIS POTENTIAL RAIN EVENT REPRESENTS THE BIGGEST THREAT FOR RIVER
FLOODING TO DEVELOP DURING THE NEXT TWO WEEKS AND WILL NEED TO BE
MONITORED CLOSELY.  CHECK FOR UPDATES REGARDING THIS THREAT FROM
YOUR LOCAL NWS OFFICE LATER THIS WEEK AND WEEKEND.

AHPS RIVER FORECASTS - NEAR NORMAL TO BELOW NORMAL.  THE ADVANCED 
HYDROLOGIC PREDICTION SERVICE (AHPS) GENERATES LONG-TERM (14 DAYS OR 
GREATER) PROBABILISTIC RIVER FORECASTS BASED ON CURRENT BASIN 
CONDITIONS (RIVER LEVELS, SOIL MOISTURE, EXTENT AND CONDITION OF ANY 
SNOWPACK) ALONG WITH 50 YEARS OF HISTORIC TEMPERATURE AND
PRECIPITATION DATA.  HOWEVER, IT IS IMPORTANT TO NOTE THAT AHPS
RIVER FORECASTS DO NOT TAKE INTO ACCOUNT ACTUAL FUTURE WEATHER
CONDITIONS WHEREAS ENSEMBLE RIVER FORECASTS (SEE NEXT SECTION) DO.
FOR THIS OUTLOOK PERIOD (THROUGH FEBRUARY 2, 2017) CURRENT AHPS
RIVER FORECASTS INDICATE A NEAR OR BELOW-NORMAL CHANCE OF RIVER
FLOODING FOR MOST MARFC RIVERS, DUE PRIMARILY TO THE LACK OF
SIGNIFICANT SNOW CONDITIONS.  THE GREATEST THREAT OF RIVER FLOODING
DEVELOPING DURING THIS OUTLOOK PERIOD IS ASSOCIATED WITH A POSSIBLE
FUTURE HEAVY RAIN EVENT, AND THIS FUTURE EVENT IS NOT INCLUDED IN
THE AHPS RIVER FORECASTS.

ENSEMBLE RIVER FORECASTS - A CONSIDERABLE THREAT OF RIVER FLOODING
DEVELOPING.  THE MOST RECENT RUNS (JANUARY 18, 2017) OF THE ENSEMBLE
RIVER FORECASTS DO SHOW A FAIRLY WIDESPREAD THREAT OF RIVER FLOODING
DEVELOPING AT NUMEROUS FORECAST LOCATIONS WITHIN THE MARFC SERVICE
AREA.  THIS THREAT IS CENTERED AROUND JANUARY 23-25, 2017 AND IS
ASSOCIATED WITH A POSSIBLY SIGNIFICANT RAIN EVENT JANUARY 22-24,
2017.  PLEASE VISIT www.weather.gov/erh/mmefs FOR ENSEMBLE RIVER
FORECASTS.

SUMMARY - THE RIVER FLOOD POTENTIAL FOR RIVERS IN THE MARFC REGION
IS AVERAGE TO ABOVE AVERAGE DURING THE FIRST WEEK, AND BELOW AVERAGE
TO AVERAGE THE SECOND WEEK.  HEAVY RAINFALL WOULD BE REQUIRED TO
CAUSE RIVER FLOODING.  A SIGNIFICANT RAIN EVENT IS QUITE POSSIBLE IN
THE SUNDAY-TUESDAY TIME FRAME NEXT WEEK, JANUARY 22-24, 2017.  THIS
RAIN EVENT WILL NEED TO BE MONITORED FOR HEAVY RAIN POTENTIAL THAT
COULD RESULT IN RIVER FLOODING DEVELOPING JANUARY 23-26, 2017.

WATER SUPPLY OUTLOOK - ACCORDING TO THE LATEST (JANUARY 10, 2017)
U.S. DROUGHT MONITOR (http://droughtmonitor.unl.edu), LARGE PORTIONS
OF THE MARFC SERVICE AREA CONTINUE TO SHOW CONDITIONS THAT RANGE
FROM ABNORMALLY DRY TO SEVERE DROUGHT.  LATEST OUTLOOKS SUGGEST
THESE DRY CONDITIONS MAY PERSIST FOR A WHILE LONGER BUT SHOULD
GRADUALLY DIMINISH OVER THE COURSE OF THE NEXT FEW WEEKS.  SO FAR
ONLY ISOLATED AND GENERALLY LOW-IMPACT WATER SUPPLY ISSUES HAVE BEEN
NOTED WITHIN THE MARFC SERVICE AREA IN ASSOCIATION WITH THE DRY
CONDITIONS.  AT THIS TIME, ASSUMING NEAR-NORMAL PRECIPITATION DURING
THE NEXT FEW MONTHS, WIDESPREAD WATER SUPPLY PROBLEMS ARE NOT
ANTICIPATED.  VISIT www.drought.gov, www.cpc.ncep.noaa.gov AND
www.weather.gov/marfc/wro_update FOR ADDITIONAL DROUGHT AND WATER
SUPPLY INFORMATION.

PLEASE VISIT THE NWS MARFC HOMEPAGE AT www.weather.gov/marfc OR FIND
US ON FACEBOOK AT www.facebook.com/NWSMARFC
AND ON TWITTER @NWSMARFC.

THE NEXT WINTER/SPRING FLOOD OUTLOOK WILL BE ISSUED BY THIS OFFICE
IN TWO WEEKS ON FEBRUARY 2, 2017.

SK
$$

....END MARFC....

NNNN

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FGUS61 KRHA 051650
ESGRHA

WINTER/SPRING RIVER FLOOD POTENTIAL OUTLOOK
MIDDLE ATLANTIC RIVER FORECAST CENTER
NATIONAL WEATHER SERVICE STATE COLLEGE PA
1149 AM EST THU JAN 5 2017 

OUTLOOK NUMBER 17-01 - JANUARY 5, 2017

THIS FIRST WINTER/SPRING RIVER FLOOD POTENTIAL OUTLOOK OF 2017 IS
VALID FOR THE TWO-WEEK PERIOD JANUARY 5-19, 2017.

THIS OUTLOOK ESTIMATES THE POTENTIAL FOR RIVER FLOODING (NOT FLASH
FLOODING) TO DEVELOP DURING THE NEXT TWO WEEKS ACROSS THE MARFC AREA
OF RESPONSIBILITY (MID-ATLANTIC REGION) BASED ON A CURRENT
ASSESSMENT OF HYDROMETEO1ROLOGICAL 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 - THE RIVER FLOOD POTENTIAL FOR MARFC
RIVERS DURING THE NEXT TWO WEEKS IS GENERALLY BELOW AVERAGE. FACTORS
WHICH CONTRIBUTE TO THIS ASSESSMENT OF RIVER FLOOD POTENTIAL ARE
DISCUSSED IN SOME DETAIL BELOW.

CURRENT FLOODING - NONE.

RECENT PRECIPITATION - GENERALLY ABOUT NORMAL. DURING THE LAST 30
DAYS (DECEMBER 6, 2016-JANUARY 4, 2017) PRECIPITATION (LIQUID
EQUIVALENT) WAS PRETTY CLOSE TO AVERAGE ACROSS MUCH OF THE MARFC
SERVICE AREA.  MOST LOCATIONS RECEIVED 2.5-4.5 INCHES OF
PRECIPITATION (WATER EQUIVALENT), WHICH WAS MOSTLY IN THE 25 PERCENT
BELOW NORMAL TO 25 PERCENT ABOVE NORMAL RANGE.  TWO AREAS WERE
SOMEWHAT DRIER.  ONE STRETCHED FROM CENTRAL PA EAST-NORTHEASTWARD
INTO NORTHERN NJ AND SOUTHEASTERN NY.  THE OTHER WAS IN A SMALL AREA
OF NORTH-CENTRAL VA.  THERE WERE ALSO SCATTERED SMALL AREAS THAT
RECEIVED SOMEWHAT ABOVE NORMAL PRECIPITATION DURING THE LAST 30
DAYS.  PLEASE VISIT www.weather.gov/marfc , THEN CLICK ON WATER
SUPPLY AND THEN ON DEPARTURES FROM AVERAGE.

SNOW CONDITIONS - AVERAGE TO MUCH-BELOW AVERAGE.  CURRENTLY WITHIN
THE MARFC SERVICE AREA SNOW IS GENERALLY CONFINED TO NY AND ABOUT
THE NORTHERN THIRD OF PA.  EVEN HERE, THE SNOW IS PATCHY WITH LITTLE
OR NO SNOW IN THE VALLEYS.  WHERE SNOW EXISTS THE DEPTHS ARE
GENERALLY SIX INCHES OR LESS WITH ISOLATED GREATER DEPTHS IN HIGHER
ELEVATIONS.  SNOW WATER EQUIVALENT VALUES ARE GENERALLY AN INCH OR
LESS, WITH 1.5-2.5 INCHES IN SOME OF THE HIGHER ELEVATIONS IN NY.
FROM ABOUT INTERSTATE 80 AND NORTHWARD, CURRENT SNOW CONDITIONS ARE
BELOW AVERAGE TO MUCH-BELOW AVERAGE.  OTHERWISE CONDITIONS ARE
PRETTY CLOSE TO NORMAL FOR EARLY WINTER.  SNOW INFORMATION CAN BE
FOUND BY VISITING www.weather.gov/marfc/Snow AND www.nohrsc.noaa.gov

RIVER ICE - AVERAGE TO MUCH-BELOW AVERAGE.  ALTHOUGH THERE HAS BEEN
SOME RIVER ICE THIS WINTER, CURRENTLY LITTLE IF ANY RIVER ICE IS
FOUND ON/IN MARFC RIVERS.  THIS IS UNUSUAL FOR EARLY JANUARY FOR
UPPER PORTIONS OF THE SUSQUEHANNA AND DELAWARE RIVER BASINS, BUT IS
PRETTY MUCH NORMAL FOR MOST OTHER RIVER BASINS.  SOME RIVER ICE
FORMATION IS EXPECTED DURING THE NEXT FEW DAYS MAINLY ACROSS ABOUT
THE NORTHWESTERN THIRD OF THE MARFC REGION.  BUT MILDER TEMPERATURES
MAY ARRIVE AGAIN BY MIDWEEK NEXT WEEK WHICH COULD ACT TO DECREASE
ANY RIVER ICE AGAIN.

STREAMFLOW CONDITIONS - VARIABLE.  THE LATEST DATA FROM THE UNITED
STATES GEOLOGICAL SURVEY (USGS) INDICATE MANY STREAMGAGES WITHIN THE
MARFC SERVICE AREA ARE SHOWING STREAMFLOWS THAT RANGE FROM NEAR
MEDIAN TO ABOVE MEDIAN FOR EARLY JANUARY.  STREAMFLOWS ARE SOMEWHAT
HIGHER CURRENTLY DUE TO THE RECENT RAIN EVENT WHICH IN SOME AREAS
ALSO COMBINED WITH SOME SNOWMELT.  THERE ARE SOME SMALL AREAS WITH
NOTABLY BELOW MEDIAN FLOWS FOR THE DATE, INCLUDING PORTIONS OF PA,
NJ AND VA.  PLEASE VISIT THE USGS WEB PAGES AT www.usgs.gov/water
FOR STREAMFLOW DATA.

SOIL MOISTURE CONDITIONS - BELOW NORMAL.  THE LONG-TERM PALMER
DROUGHT SEVERITY INDEX IS USED TO INFER DEEP SOIL MOISTURE
CONDITIONS.  THE DECEMBER 31, 2016 CHART (FOUND AT
www.cpc.ncep.noaa.gov/products/analysis_monitoring/
regional_monitoring/palmer.gif)
SUGGESTS DEEP SOILS ACROSS MUCH OF
THE MARFC SERVICE AREA CONTAIN MOISTURE THAT IS FAIRLY CLOSE TO
NORMAL FOR THIS TIME OF YEAR.  HOWEVER, OTHER SOIL MOISTURE
INFORMATION (GO TO www.cpc.ncep.noaa.gov/products/Soilmst_Monitoring
AND THEN CLICK ON THEN CLICK ON U.S. MONITORING) SHOWS CONSIDERABLE
SOIL MOISTURE DEFICITS REMAIN ACROSS LARGE PORTIONS OF THE MARFC
REGION.  THIS SUPPORTS THE MOST RECENT VERSION (JANUARY 3, 2017) OF
THE U.S. DROUGHT MONITOR CHART WHICH SHOWS LARGE PORTIONS OF THE
MARFC REGION EXPERIENCING ABNORMALLY DRY TO SEVERE DROUGHT
CONDITIONS (http://droughtmonitor.unl.edu).

GROUNDWATER - VARIABLE.  MANY USGS GROUNDWATER MONITORING WELLS
ACROSS THE MARFC REGION ARE CURRENTLY INDICATING GROUNDWATER LEVELS
THAT ARE BELOW OR EVEN MUCH-BELOW THEIR LONG-TERM NORMALS FOR THIS
TIME OF YEAR.  THERE ARE SOME WELLS SCATTERED ACROSS THE REGION WITH
NEAR NORMAL OR EVEN SOMEWHAT ABOVE-NORMAL WATER LEVELS, WITH NO
IDENTIFIABLE PATTERN.  VISIT https://groundwaterwatch.usgs.gov.

RESERVOIR CONDITIONS - BELOW AVERAGE TO AVERAGE.  IN GENERAL, MOST
MAJOR RESERVOIRS WITHIN THE MARFC REGION ARE HOLDING STORAGES THAT
ARE IN THE BELOW AVERAGE/AVERAGE RANGE FOR THIS TIME OF YEAR.
RESERVOIR STORAGE IN THE UPPER DELAWARE RIVER BASIN IS CURRENTLY
CONSIDERABLY BELOW THE LONG-TERM MEDIAN.

FUTURE WEATHER CONDITIONS - TYPICAL JANUARY WEATHER WITH COLD
TEMPERATURES AND ONLY LIGHT/MODERATE PRECIPITATION IS EXPECTED FOR
THE NEXT FEW DAYS.  SOME SNOW IS EXPECTED PRETTY FAR SOUTH.  MILDER
TEMPERATURES ARE EXPECTED EARLY-MID WEEK NEXT WEEK ACCOMPANIED BY
POSSIBLY SOME MODERATE RAIN.  LONGER-RANGE WEATHER OUTLOOKS SUGGEST
ABOVE AVERAGE TEMPERATURES AND PRECIPITATION FOR MUCH OF THE MARFC
REGION WHEN AVERAGED OVER THE NINE DAY PERIOD FROM JANUARY 10-18,
2017.  LONGER-RANGE WEATHER OUTLOOKS CAN BE VIEWED AT
www.cpc.ncep.noaa.gov .

AHPS RIVER FORECASTS - NEAR NORMAL TO BELOW NORMAL.  THE ADVANCED 
HYDROLOGIC PREDICTION SERVICE (AHPS) GENERATES LONG-TERM (14 DAYS OR 
GREATER) PROBABILISTIC RIVER FORECASTS BASED ON CURRENT BASIN 
CONDITIONS (RIVER LEVELS, SOIL MOISTURE, EXTENT AND CONDITION OF ANY 
SNOWPACK) ALONG WITH 50 YEARS OF HISTORIC TEMPERATURE AND
PRECIPITATION DATA.  HOWEVER, NOTE THAT AHPS RIVER FORECASTS DO NOT
TAKE INTO ACCOUNT ACTUAL FUTURE WEATHER CONDITIONS.  FOR THIS
OUTLOOK PERIOD (THROUGH JANUARY 19, 2017) CURRENT AHPS RIVER
FORECASTS INDICATE A NEAR OR BELOW-NORMAL CHANCE OF RIVER FLOODING
FOR MOST MARFC RIVERS.  THIS REINFORCES THE IDEA THAT RIVER FLOODING
WITHIN THE MARFC REGION IS RELATIVELY UNCOMMON IN JANUARY AND THAT
SIGNIFICANT WIDESPREAD RAINFALL WOULD BE NECESSARY FOR RIVER
FLOODING TO DEVELOP.

ENSEMBLE RIVER FORECASTS - A MINIMAL THREAT OF ISOLATED RIVER
FLOODING. THE MOST RECENT RUNS (JANUARY 5, 2017) OF THE ENSEMBLE
RIVER FORECASTS SHOW JUST A MINIMAL THREAT OF ISOLATED RIVER
FLOODING DEVELOPING IN THE NY BASINS DURING THE NEXT WEEK.  THIS
MINIMAL THREAT IS CENTERED AROUND 1/11-1/12 AND IS ASSOCIATED WITH A
SNOWMELT/RAIN EVENT AROUND THAT TIME PERIOD.  PLEASE VISIT
www.weather.gov/erh/mmefs FOR ENSEMBLE RIVER FORECASTS.

SUMMARY - THE RIVER FLOOD POTENTIAL FOR RIVERS IN THE MARFC REGION
DURING THE NEXT TWO WEEKS IS GENERALLY BELOW AVERAGE.  HEAVY
RAINFALL WOULD BE REQUIRED TO CAUSE RIVER FLOODING.  A
SNOWMELT/RAINFALL EVENT COULD OCCUR JANUARY 11-12 AND WILL NEED TO
BE MONITORED.  ANOTHER EVENT COULD OCCUR AROUND JANUARY 15-16.  

WATER SUPPLY OUTLOOK - ACCORDING TO THE LATEST (JANUARY 3, 2017) U.S.
DROUGHT MONITOR (http://droughtmonitor.unl.edu), LARGE PORTIONS OF
THE MARFC SERVICE AREA ARE SHOWING CONDITIONS THAT RANGE FROM
ABNORMALLY DRY TO SEVERE DROUGHT.  LATEST OUTLOOKS SUGGEST THESE DRY
CONDITIONS MAY PERSIST AT LEAST THROUGH THE REMAINDER OF JANUARY AND
PERHAPS LONGER.  VISIT WWW.DROUGHT.GOV, WWW.CPC.NCEP.NOAA.GOV AND
WWW.WEATHER.GOV/MARFC/WRO_UPDATE FOR ADDITIONAL DROUGHT AND WATER
SUPPLY INFORMATION.

PLEASE VISIT THE NWS MARFC HOMEPAGE AT www.weather.gov/marfc OR FIND
US ON FACEBOOK AT https://www.facebook.com/NWSMARFC
AND ON TWITTER @NWSMARFC.

THE NEXT WINTER/SPRING FLOOD OUTLOOK WILL BE ISSUED BY THIS OFFICE
IN TWO WEEKS ON JANUARY 19, 2017.

SK
$$

....END MARFC....

NNNN

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