Flooding along many rivers; mild temps keep the snowmelt going

We hit 50 degrees at Minneapolis-St. Paul International Airport Thursday afternoon. It was our first high temp in the 50s since Nov. 1.

Our shrinking snow cover assisted in the warmup.

The National Oceanic and Atmospheric Administration’s satellite picture shows very little snow cover from the Twin Cities metro area into south-central Minnesota:

Thursday afternoon NOAA satellite picture, via College of DuPage

You can see that there’s still snow and ice on Lake Minnetonka and Mille Lacs Lake.

There’s also some snow cover in much of southwestern and central Minnesota, and plenty of snow cover in most of northern Minnesota right now.

Temperature trends

Minnesota highs will be mostly in the 40s this Friday afternoon, a few spots in southern Minnesota and the Twin Cities metro area could touch 50 degrees. Our average high this time of year is 44 degrees in the Twin Cities metro area.

Saturday will bring 50s to many areas:

Sunday highs will range from the 30s northwest to around 50 southeast:

Twin Cities metro area highs are projected to reach the lower 40s Monday, followed by upper 40s Tuesday, upper 50s Wednesday and around 60 on Thursday.

Rain and snow chances

We don’t see any really wet weather the next few days, but there’ll be a chance of a rain-snow mix in northern Minnesota Saturday night and Sunday, with a chance of rain showers in central and southern Minnesota plus western Wisconsin.

NOAA’s North American Mesoscale forecast model shows the potential precipitation pattern Saturday evening through Sunday evening:

NOAA NAM simulated radar from Saturday afternoon through Sunday evening, via tropicaltidbits

The color chart to the right of the loop refers to the strength of the signal that returns to the radar, not to the amount of rain or snow.

River flooding 

Moderate to major flooding continues at several spots along the Minnesota River. The Cottonwood River at New Ulm is now back to major flood stage.

You can get flood warning updates by clicking on any location on the National Weather Service Twin Cities website. Areas with flood warnings are shaded green on the NWS main page, and here’s how the map looked Friday morning:

NWS Twin Cities

The light green area that includes Fergus Falls is a hydrologic outlook, not a warning:

Hydrologic Outlook
National Weather Service Grand Forks ND
1052 AM CDT Thu Mar 21 2019

…SLOW THAW CONTINUES…

Favorable melt conditions have persisted through the past week as
temperatures have warmed above freezing during the day while
dropping back below freezing at night.

The end of the current work week and start of the weekend will bring
even warmer temperatures to the region as highs push into the 40s on
Saturday. These temperatures will continue to further ripen the
snowpack and even allow some water to begin ponding and moving into
local drainage. These conditions will most likely be seen across the
far southern Red River Valley and into portions of west central
Minnesota where the warmest temperatures are expected.

However, this degree of melting and initial moving of water is
expected to be short-lived as the region will experience another dip
in temperatures by Sunday and into the first part of the new work
week. Additionally, a weak weather system will skirt southern
portions of the region bringing only minor amounts of precipitation.
Full blown river flooding and extensive overland flooding is not
expected to begin quite yet as we head into the first half of next
week.

After the brief cooldown at the beginning of next week, the region
will see temperatures increase once again mid to late week. High
temperatures in the 40s (possibly low 50s) will be likely region-
wide for the second half of the week with southern locations
possibly remaining above freezing even during the overnight hours.
Following the minor precipitation chances this weekend, quiet and
dry weather looks likely for the first half of next week before a
return to a more active pattern is possible.

The last probabilistic outlook issued on March 15th remains valid
for the time being. This outlook incorporates average weekly
precipitation amounts of roughly one-quarter of an inch and an
average temperature regime. Thus far, the precipitation and
temperature pattern has been in agreement with these values. Future
storm systems will continue to be monitored as we potentially turn
to a more active pattern by the end of next week.

Lastly, there will be no additional probabilistic outlooks issued
this spring as we get closer to widespread melting and the issuance
of deterministic forecasts. However, an updated thaw progress
statement will be issued on Monday, March 25th regarding the status
of the snowmelt, forecast weather conditions and the impacts on
future flood potential.

The Mississippi River at St. Paul is expected to rise about 7.4 feet between Friday morning and next Wednesday. The St Croix River at Stillwater expected to rise about 5.5 feet by next Thursday. Both rivers will continue to rise beyond next week.

You can click on any location on the NWS Advanced Hydrologic Prediction Service  (AHPS) site to get hydrographs of recent and forecast river levels. Some locations list levels in feet above sea level, others list levels in feet above a local reference point.

Here’s the Friday morning hydrograph for the Mississippi River at St. Paul:

NOAA/NWS/U.S. Geological Survey

Here is the hydrograph for the St. Croix River at Stillwater:

NOAA/NWS/U.S. Geological Survey

Here’s the hydrograph for the Cottonwood River at New Ulm:

NOAA/NWS/U.S. Geological Survey

The Minnesota River at Jordan is in moderate flood stage and still rising:

NOAA/NWS/U.S. Geological Survey

Projected crests are updated on a regular basis, so check back to the AHPS site and NWS point forecasts for the latest info on the rivers near you.

If you’d like to scroll through hydrographs along a certain river, check here.

Programming note

You can hear my live weather updates on Minnesota Public Radio at 7:49 a.m. Thursdays and Fridays, and at 7:35 a.m., 9:35 a.m. and 4:35 p.m. each Saturday and Sunday.