NWS: Friday's Storm Could Be Most 'Extreme' Rain Event In 20 Years For Twin Cities

TWIN CITIES, MN — The National Weather Service is warning that Friday's rain event could rank among the most extreme rainfall events the Twin Cities region has seen in two decades, with the potential for localized flooding.

Forecasters at NWS Twin Cities/Chanhassen say a long-duration round of soaking rain will begin Friday morning and continue through much of the day into early Saturday.

A broad swath of the region can expect 1 to 2 inches of rain, and NWS said in its Wednesday morning forecast discussion that "a stripe of at least 3 inches will fall somewhere and possibly greater than 5 or 6."

The system driving the rain is currently sitting far away in the Gulf of California, forecasters said.

It will track north through the Four Corners region and the western High Plains before reaching Minnesota on Friday, pulling in significant moisture along the way.

Meteorologists say dewpoints will climb into the 60s as the system approaches.

What has forecasters especially concerned is the strength of the signal.

In its discussion, the agency put it bluntly: "This may be an extreme event."

Confidence is high that most of the metro will see at least an inch of rain.

Where confidence drops is in pinpointing the exact location of the heaviest band. As of Wednesday morning, guidance suggested the heaviest rain could fall somewhere between Willmar and Redwood Falls, stretching east through the southern Twin Cities metro and into the Eau Claire and La Crosse areas, though NWS cautioned that placement could still shift.

The agency also raised the possibility of formal warnings ahead of the storm.

"Flood watches may eventually be needed," NWS said, adding that the risk is heightened if the heaviest rainfall lands over an urban area, where runoff moves quickly into storm systems and low lying roads.

Drier weather is expected to return Saturday as the front temporarily pushes south. Another system will move in from the Rockies by early next week, which forecasters say could bring another round of unsettled weather.

Residents are urged to monitor updated forecasts as Friday approaches, since the exact placement of the heaviest rainfall remains one of the biggest open questions in the forecast.

Check out the full NWS-MSP forecast below:

Thursday: Patchy fog before 8am. Otherwise, partly sunny, with a high near 77. Calm wind becoming northeast around 5 mph in the afternoon.

Thursday Night: A 30 percent chance of showers after 5am. Increasing clouds, with a low around 59. Northeast wind 5 to 10 mph.

Friday: Showers, with thunderstorms also possible after 1pm. Some of the storms could produce heavy rainfall. High near 67. East wind 10 to 15 mph, with gusts as high as 30 mph. Chance of precipitation is 100%. New rainfall amounts between 1 and 2 inches possible.

Friday Night: Showers and possibly a thunderstorm before 1am, then showers likely. Low around 60. Breezy, with an east wind 15 to 20 mph, with gusts as high as 30 mph. Chance of precipitation is 100%. New rainfall amounts between three quarters and one inch possible.

Saturday: A 30 percent chance of showers before 1pm. Cloudy, with a high near 69. North northeast wind around 15 mph.

Saturday Night: Mostly cloudy, with a low around 55. Northeast wind 5 to 10 mph.

Sunday: Mostly cloudy, with a high near 68. East northeast wind 5 to 10 mph.

Sunday Night: A 30 percent chance of showers, mainly after 1am. Mostly cloudy, with a low around 53. East northeast wind around 5 mph.

Monday: A 40 percent chance of showers. Mostly cloudy, with a high near 65. East wind 5 to 10 mph.

Monday Night: A 20 percent chance of showers. Mostly cloudy, with a low around 53. East wind around 5 mph.

Tuesday: Partly sunny, with a high near 68. East wind around 5 mph.

Tuesday Night: Mostly cloudy, with a low around 53. East southeast wind around 5 mph becoming calm in the evening.

Wednesday: A 20 percent chance of showers. Partly sunny, with a high near 72. Southeast wind around 5 mph becoming southwest in the afternoon.