River flooding update; next widespread rain on Thursday?

Two weeks ago, we were dealing with a weekend snowstorm. This weekend started out much nicer, with plenty of sunshine on Saturday and highs in the 50s and upper 40s across most of Minnesota.

March is a fickle month!

Temperature trends 

Sunday highs will be mainly in the 40s, with some 30s in far northern Minnesota. A few spots in the Twin Cities metro area and southern Minnesota could touch 50 degrees:

Our average March 24 high temp is 45 degrees in the Twin Cities metro area.

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

Wednesday will be the warmest day of the week across most of Minnesota and western Wisconsin:

Rain and snow chances 

Southwestern Minnesota will have a chance of scattered Saturday evening rain showers. A few scattered rain showers are possible overnight Saturday night and Sunday morning in southern Minnesota, with the best chance in the far south. A passing shower or sprinkle is possible in the Twin Cities metro area late Saturday night and Sunday morning.

Northern Minnesota will have a chance of sprinkles/flurries/light freezing drizzle late Saturday night and also Sunday morning.

As always, updated weather information can be heard on the Minnesota Public Radio Network, and you’ll also see updated weather info on the MPR News live weather blog.

Periods of rain look likely in parts of southern and central Minnesota late Wednesday night into Thursday and Thursday night. The National Oceanic and Atmospheric Administration’s Global Forecast System model shows the potential precipitation pattern Wednesday evening through Friday morning:

NOAA GFS precipitation rate (mm/hour) Wednesday evening through Friday morning, via tropicaltidbits

The color chart to the right of the loop refers to the precipitation rate (mm per hour), not to the total amount of rain or snow.

We don’t need any additional rain right now, so let’s hope that the models change as we get closer to Thursday.

River flooding

Our spring snow melt continues to cause flooding in many locations.

Significant flooding continues in many areas along the Minnesota River, and river levels are still rising in much of southern Minnesota. The Cottonwood River at New Ulm is at major flood stage and it’ll stay at major flood stage through the coming week.

As of Saturday evening’s flood forecasts, the Minnesota River is expected to reach major flood stage at Savage on Monday, and at Montevideo on Tuesday.  The Minnesota River is expected to reach major flood stage at New Ulm on Thursday.

Many areas have flood warnings. 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 Saturday evening:

NWS Twin Cities

The Mississippi River at St. Paul was nearing flood stage late this Saturday afternoon.  Here’s the NWS Saturday morning update:

1045 AM CDT Sat Mar 23 2019

…The Flood Warning continues for
The Mississippi River at St. Paul.
* from this afternoon until further notice.
* At 10:00 AM Saturday the stage was 13.2 feet.
* Major flooding is forecast.
* Flood stage is 14.0 feet.
* Forecast…Rise above flood stage by this afternoon and
continue to rise to near 20.5 feet by Friday morning. Additional
rises are possible thereafter.
* Impact…At 18.0 feet…Warner Road may become impassable due to
high water.
* Impact…At 17.5 feet…Harriet Island begins to become submerged.
* Impact…At 14.0 feet…Portions of the Lilydale park area begin to
experience flooding.
* Impact…At 13.3 feet…Water begins to encroach on Water St.

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 Saturday evening hydrograph for the Mississippi River at St. Paul:

NOAA/NWS/U.S. Geological Survey

The 20.5 level late in the week would be the seventh highest Mississippi River level ever recorded at the St. Paul gauge:

NOAA/NWS/USGS data for the Mississippi River at St. Paul

Water is already covering some of the steps in front of the pavilion at Harriet Island in St. Paul:

March 23, 2019    City of St. Paul webcam

And water also covers parts of Raspberry Island:

March 23, 2019     City of St. Paul webcam

You can imagine what this area will look like as the river rises another 6.7 feet by early Friday.

Here’s the hydrograph for the St. Croix River at Stillwater:

NOAA/NWS/USGS

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

The NWS also posts some flooding details here.

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.