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NCRFC Spring Hydrologic Outlook

2018 Spring Outlook issuance dates have been coordinated with all NWS regions and NWS HQ:

  • Thursday February 15, 2018 - RFCs will publish Outlook Probability Graphics and Weather Forecast Offices will  issue outlook products and discussions.
  • Thursday March 1, 2018 - RFCs will publish Outlook Probability Graphics and Weather Forecast Offices will issue outlook products and discussion.
  • During week of March 12-16, 2018 - Flood Safety Awareness information will be provided.
  • Thursday March 15, 2018 - NOAA National Spring Outlook Press Briefing.

 

Spring Outlook Probabilities

Please Note...Information about current river forecasts can be found by clicking on a river forecast point on the NCRFC Home Page. This will take you to the Advanced Hydrologic Prediction Service (AHPS) Home Page. From there you can link to a Weather Forecast Office Home Page where you can find more detailed statements and warnings about current river conditions.

 

2018 Late Winter Basin Conditions as of February  2018


Flood potential analyses are based on current soil and snow conditions combined with a broad spectrum of potential spring weather conditions reflected in the climate record from 1948 to 2013. The analyses contain herein are very general. A quantified risk of flooding with respect to climatology is available through web graphics and tables can be found at NWS Long_Range Flood Risk, along with links to Weather Forecast Office Home Pages

 

Going into the fall months, precipitation was below normal for most of the NCRFC region, with the exception of the Hudson Bay drainage, where rainfall was above normal in September, and below normal in October and November. Fall temperatures were generally above normal. September and October were 2 to 5 degrees above normal, but November saw a turn to the colder weather that would dominate through the winter months.

November and December brought our transition into winter, with temperatures dropping below normal, where they would stay through the season thus far. November and December ranged from 2 to 5 degrees cooler than normal on average. January saw a few warmer periods, with monthly averages only coming in a few degrees cooler than normal. But February saw a plunge into the deep freeze, with temperatures running 9 to 15 degrees below normal thus far.

The overall dry trend continued, with some portions of western Minnesota remaining virtually snow-free all the way into February. Other than a strong storm system that brought significant rain and snow to the region in mid-January, very few larger storm systems impacted the Upper Midwest, limiting the amount of precipitation thus far this winter.

That January system did result in some minor flooding issues for portions of Iowa, Illinois, and Wisconsin, as rainfall amounts of 1 to 1.5 inches fell on frozen ground. The resulting rapid runoff led to some streams rising out of their banks, and ice chunks to lodge for a few localized ice jams.

Snow cover around the region is widespread as of February 13th, but amounts are relatively light. Snow depth is only an inch or less for portions of western Minnesota, and extending up into southeast, central, and western North Dakota. Eastern North Dakota to northern Minnesota has a snow pack of up to 7 to 12 inches, with higher amounts of 15 to 20 inches closer to the international border and in the Arrowhead region. A band of snow extends from southern Minnesota across Wisconsin, with depths as much as 8 to 12 inches, while another band stretches across Iowa, through southern Wisconsin and northern Illinois, and into lower Michigan.

Water equivalent in the snow is highest over the Upper Peninsula of Michigan, where liquid amounts are up to 8 to 10 inches in the favored lake effect regions. Liquid equivalent of 3 to 4 inches is seen over parts of far northern Minnesota, northern Wisconsin, and northern portions of lower Michigan. Water amounts of 1 to 2 inches extended across portions of Iowa, into southern Wisconsin and northern Illinois, northern Indiana, and across Michigan.

Soil conditions are rather dry for much of the region, with the exception of near the Great Lakes. The U.S. Drought Monitor indicates abnormally dry or moderate drought conditions across the Dakotas, and also from Missouri and southeast Iowa, into adjacent portions of Illinois and southern Wisconsin. Soil moisture ranking from the Climate Prediction Center shows that portions of North Dakota, Missouri, and Illinois are all in the lowest 5 or 10 percent when compared to historical records. The only area that is seeing excessive soil moisture is from the Minnesota Arrowhead, across the western Great Lakes, and into lower Michigan.

As a result of the cold temperatures and general lack of deep snow across most of the NCRFC area, the frost has gone deeper than normal. Without snow cover to insulate the ground, the cold air helped push frost depth to 3 to 4 feet from North Dakota, across much of Minnesota and into Wisconsin. Some reports of frozen water lines have been received in Minnesota recently. For areas that have seen a little snow cover, from Iowa into southern Wisconsin, frost depth ranges from 18 to 36 inches. A bit further to the south, from Missouri, across Illinois and Indiana, and into southern lower Michigan, the warm spell and rain event in mid-January have helped keep the frost from getting too deep, with reports between 3 and 12 inches.

Stream flow across much of the region is below normal, with the exception of areas closer to the Great Lakes, from the Minnesota Arrowhead, across the U.P. and northern Wisconsin, into lower Michigan. There, river flow is above normal.

 

GREAT LAKES DRAINAGE

Overall, the flood potential for this area this spring is near normal.

Temperatures were 1 to 4 degrees above normal in September and October, and then the winter cold set in. November temperatures were 1 to 3 degrees below normal, and December was 2 to 6 degrees below normal. January had a mix of warm and cold periods, but the first half of February has been quite cold, averaging from 6 to as much as 15 degrees below normal.

Precipitation-wise, September was dry for most of the Great Lakes region, except for along Lake Superior, which was wetter than the average. The pattern shifted for October, with precipitation from 125 to 200 percent of normal. November saw varied precipitation, which resulted in below normal values over Minnesota and Wisconsin, and above normal values from Illinois to Michigan. December and so far in 2018, areas along the Great Lakes have seen above normal precipitation, with lengthy periods of cold temperatures bringing plenty of lake-effect snowfall. A mid-January warm spell brought warm air and some rainfall, which melted some of the snow that had accumulated. But more has since fallen to re-establish a modest snowpack.

The wet periods allowed soil moisture to become quite high, and many reservoirs were running high as well. This has kept overall river flows higher than normal through the winter.

The cold temperatures have helped with ice production, with the Great Lakes having over 69 percent ice cover as of Feb 12th. This is the most ice since 2014, and only the 2nd time that this much ice has been seen in the past 24 years. River ice has been thicker than normal, and some ice jamming has been seen in a few tributaries such as the Grand, Menomonie, and Looking Glass Rivers.

The snow is quite deep in the Upper Peninsula thanks to the repeated lake-effect, with some areas reporting over 30 inches. Amounts over 20 inches are noted as far south as northern Wisconsin, and also over northern parts of lower Michigan. Snow depth between 4 and 15 inches are seen across the remainder of Michigan, as well as southern Wisconsin and northern portions of Illinios and Indiana. Water equivalent in this snow cover ranges from around 8 inches in the Upper Peninsula, to 1 to 2 inches from Chicago to Detroit. The lowest snow cover and water amount runs from central Wisconsin, through Green Bay, and over toward Alpena Michigan.

Thanks to the January thaw, frost depth is not terribly deep. Depth is only 4 to 6 inches over southern Michigan, and generally less than a foot south of a line from the thumb back toward the Chicago area. Much deeper frost is seen across Wisconsin, where snow cover has been minimal. Frost is as deep as 3 to 4 feet in some places.

Overall, the flood potential for this area this spring is near normal. With a somewhat limited snow cover, at this point in time the risk for flooding due to snow itself is rather low. But with a cool spring anticipated based on the latest outlooks, and with some areas seeing deep frost, runoff rates could be enhanced due to the frozen ground, especially if the frost does not go out of the ground until later in the spring, or if heavy spring rains are seen.

UPPER MISSISSIPPI RIVER DRAINAGE

Overall, the flood risk for this drainage area is near normal, or perhaps slightly below normal.

Fall temperatures were generally above normal. September and October were 2 to 5 degrees above normal, but November marked the beginning of winter with temperatures below the norm. November and December ranged from 2 to 5 degrees cooler than normal. It was a bit warmer in January, but February saw a plunge into the deep freeze, with temperatures well below normal for the first half of the month.

Other than October, which saw precipitation amounts over 200 percent of normal, the remainder of the fall and winter months has been rather dry. Snow cover has been well below the norm as well, especially over Minnesota and Wisconsin. Some portions of western Minnesota remained nearly snow free all the way into early February. Even now depth there is only a few inches.

A strong storm system brought significant rain and snow to much of the region in mid-January. This thaw produced some melt, and the added rainfall did result in some minor flooding issues for portions of Iowa, Illinois, and Wisconsin, as rainfall amounts of 1 to 1.5 inches fell on frozen ground. The resulting rapid runoff led to some streams rising out of their banks, and ice chunks to lodge for a few localized ice jams. The cold February and some passing systems resulting in a pretty widespread snow cover, reaching all the way to the Iowa/Missouri border, and through central Illinois. But depth and water amounts are not that high. Depth is only an inch or less for portions of western Minnesota. A band of snow extends from southern Minnesota across Wisconsin, with depths as much as 8 to 12 inches, while another band stretches from Iowa through southern Wisconsin and northern Illinois.

Water equivalent in the snow is highest from northern Minnesota into northern Wisconsin, where liquid amounts are up to 3 to 4 inches. Water amounts of 1 to 2 inches extended across portions of Iowa, into southern Wisconsin and northern parts of Illinois and Indiana.

Soil conditions are rather dry, with the U.S. Drought Monitor showing abnormally dry or moderate drought conditions from Missouri and southeast Iowa, into adjacent portions of Illinois and southern Wisconsin. Soil moisture ranking from the Climate Prediction Center shows that portions of Missouri and Illinois are in the lowest 5 or 10 percent when compared to historical records.

As a result of the cold temperatures and general lack of deep snow, the frost has gone deeper than normal. Without snow cover to insulate the ground, the cold air helped push frost depth to 3 to 4 feet across much of Minnesota and into Wisconsin. Some reports of frozen water lines have been received in Minnesota recently. For areas that have seen a little snow cover, from Iowa into southern Wisconsin, frost depth ranges from 18 to 36 inches. A bit further to the south, from Missouri, across Illinois and Indiana, the warm spell and rain event in mid-January have helped keep the frost from getting too deep, with reports between 3 and 12 inches.

Stream flow across much of the region is normal or below normal.

Overall, the flood potential for this area this spring is near normal, or perhaps slightly below normal for some spots. With a somewhat limited snow cover, at this point in time the risk for flooding due to snow itself is rather low. But with a cool spring anticipated based on the latest outlooks, and with some areas seeing deep frost, runoff rates could be enhanced due to the frozen ground, especially if the frost does not go out of the ground until later in the spring, or if heavy spring rains are seen. Behavior like this was already seen in a few places during the rain event in mid-January, so this will bear watching later this spring.

HUDSON BAY DRAINAGE

 

Red River of the North River Basin

Going into the fall months, precipitation was above normal in September, and below normal in October and November. Over the winter months, precipitation has been near normal.

September and October saw temperatures 1 to 3 degrees above normal, but November and December saw temperatures 1 to 3 degrees below average. January saw a few warmer periods, resulting in an average temperature, but February saw a drastic change, with temperatures running 11 to 15 degrees below normal so far.

The overall dry trend continued, with a very limited snow cover all through the winter months. Snow depth is only an inch or less for the headwater area of west-central Minnesota, and reaching up into southeast and central North Dakota. Northeastern North Dakota to northern Minnesota has a snow pack of up to 6 to 10 inches.

Water equivalent in the snow is highest over northwest Minnesota, where liquid amounts are up to around 3 inches nearer to Lake of the Woods.

Ice thicknesses on USACE reservoirs is normal to above normal, suggesting similar conditions in the rivers. Furthermore, river flows in the Red River Basin were above normal going into the winter following heavy rains in September. This higher flow has helped to enhance the production of frazil ice in the rivers. If the spring melt and rainfall generate significant runoff, break-up ice jams could form. The effects of ice jams are not included in any of the long range probabilistic outlooks.

Frost depths are deeper than normal this winter. In both late October and late November of last year, the snowpack melted off completely across the basin adding about 0.5" to 1.0" of water to the soil. Depths of 3 to 4 feet have been reported. This combination of soil water and frost could lead to higher potential for runoff due to the frozen ground, especially if the melt is sudden and accompanied by rainfall or more snow between now and the melt.

Souris River Basin and Devils Lake Basins

Going into the fall months, precipitation was above normal in September, and below normal in October and November. Over the winter months, precipitation has been slightly below normal.

September and October saw temperatures a degree or two above normal, but November and December saw temperatures drop a few degrees below the average. January saw a few warmer periods, resulting in an average temperature, but February saw a drastic change, with temperatures as much as 12 to 15 degrees below normal.

The overall dry trend continued, with a very limited snow cover all through the winter months. Snow depth is only a few inches for much of the Souris and Devils Lake basins. Water equivalent in that snow is under an inch for the most part. Snow amounts and snow water is a little higher just north of Devils Lake, but the majority of that will drain to the north and east.

Ice thickness is above normal, and river flows are near normal.

Frost depths are deeper than normal this winter. With a lack of deep snow cover, frost depth has been allowed to penetrate to between 3 and 4.5 feet. The deep frost could contribute to the possibility for enhanced runoff due to the frozen ground, especially if the melt is sudden and accompanied by rainfall or more snow between now and the melt.

 

Climate Summary
Links to most current condition graphics are updated throughout the season, however text discussions are updated with the issuance of the Spring Flood Outlooks beginning late February 2018, followed by updates in March.
NCRFC Outlooks include information from National Weather Service sources along with reference to data from the following partner agencies:
United States Geological Survey (USGS),National Operational Remote Sensing Center (NOHRSC)
Regional Climate Centers (MRCC and HPRCC),U.S. Drought Monitor (NIDIS)
MRCC
MRCC Climate Watch
 HPRCC
High Plains RCC
USGS Waterwatch
USGS WaterWatch
US Drought Monitor
US Drought Monitor
Current snow and soil conditions

NCRFC Frost Depth
Observed Snow Depth
NOHRSC Snow Depth

NCRFC Simulated SWE

NCRFC SWE Ranking
Climate Outlook


CPC 6 to 10 Day Outlook

CPC 30 day Outlook

CPC 90 Day Outlook