366
FGUS63 KMSR 121556
ESGMSR

FGUS63 KMSR 261449
ESGMSR

Upper Midwest Spring Snowmelt and Flood Potential Outlook
NWS North Central River Forecast Center Twin Cities/Chanhassen MN
1055 AM CDT Wed Mar 12, 2025

This is the third and final Spring Flood Outlook to be provided
this year, to discuss hydrologic conditions across the region,
and the associated potential for spring flooding.

To view the NCRFC 2025 Spring Hydrologic Outlook storymap, which
includes a more detailed description of the flood outlook and
images, refer to: http://www.weather.gov/NCRFC and select the
2025 Spring Hydrologic Outlook news headline near the top of the
page.

This outlook references information from many sources, including
the following core partners:

 *United States Geological Survey (USGS)
 *Regional Climate Centers (Midwest-MRCC and High Plains-HPRCC)
 *US Drought Monitor (NIDIS)
 *US Army Corps of Engineers (USACE)
 *NOAA, Office of Water Prediction (OWP), formerly known as
   National Operational Hydrologic Remote Sensing Center (NOHRSC)

The following 2025 Spring Outlook issuance dates have been set in
coordination with all NWS regions and NWS headquarters:

National Weather Service issues Spring Flood Outlook with
probabilistic products on:

 * Thursday, February 13, 2025 (Complete)
 * Thursday, February 27, 2025 (Complete)
 * Thursday, March 13, 2025

            ********************************
             Spring 2025 NCRFC Area Summary
            ********************************

Overall, the conditional flood risk for the NCRFC area this
Spring is below normal when compared to what is historically
expected for the mid March to mid June outlook period. The
exception is for rivers in the state of Missouri, the southern
half of Iowa, and the southern half of Illinois where flood risk
is near normal.

Outside typical wet conditions from spring snowmelt and a brief
wet period late last Spring into early Summer, drought conditions
have plagued the NCRFC service area off and on since the Summer
of 2020. Following some record flooding that occurred across
Minnesota and Iowa last June and July, dry conditions have been
persistent across a majority of the service area since August
2024. These dry conditions set the northern NCRFC service area up
for below average soil moisture conditions going into winter
freeze-up.

The winter precipitation accumulation between December 2024 and
March 2025 has been below normal for the NCRFC area, with much of
the area receiving 50-75 percent of normal precipitation.

Due to the lack of snow to insulate the soil, coupled with
multiple surges of bitter cold arctic air events, conditions have
been favorable for developing deeper than average frost depths.
Frost depths slightly decreased since the last outlook and are
expected to continue decreasing now that we are entering the
winter to spring transition period. Deep frost is considered a
key ingredient for significant spring flooding because it
increases the risk of excessive surface runoff in rapid melt-off,
rain-on-snow, and heavy rainfall scenarios. Please note that this
potential driver of flooding is not fully captured by the
hydrologic model exceedance probabilities.


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JDT/NCRFC