Models: Saturday storm shifts east; Metro rainfall forecast drops; Lake temps plummet

Trending East: GFS & NAM models continue to push Saturday's storm further east

Decreasing rainfall forecasts for the Twin Cities metro area

Sharp rainfall gradient latest models suggest Twin Cities on the western edge of any significant rainfall Saturday

Wisconsin soaker Good soaking rains from Iowa into Wisconsin may totals 2"+ in some areas

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Lake temps plummet - Minnesota lake temps fall dramatically from warm summer levels

"When in a drought.....

....don't predict rain." - Wise anonymous weather forecaster

That old saying looks like it may come back to bite the Twin Cities and much of Minnesota this weekend.

Thursday's forecast model runs continued the trend of shoving Saturday's Midwest weather maker farther to the east.

"The trend is your friend." - Craig Edwards

Or maybe our enemy at this point in drought plagued Minnesota.

If the new trends hold, much of central and western Minnesota may get skunked when it somes to desperately needed rainfall this weekend. The Twin Cities now hangs on the precarious western edge of the rain shield according to the NAM and GFS runs. The chances of a good soaking rain are dropping by the hour for the Twin Cities.

[image]

Source: NOAA/ARL

To the southeast, Iowa and Wisconsin look to reap the benefit of a still strong weather system that appears to me mercilessly steering east of Minnesota. Widespread soaking rains look probable east & south...and may still clip the southeastern corner of Minnesota Saturday.

Source: NOAA/HPC

For the metro? The latest trends suggest a minor soaking in Red Wing, and a dusty breeze in Rogers.

Source: NOAA via Iowa State University

Let's hope the models and the system does a left turn Friday. I was hoping to water my thirsty trees and lawn the natural way this weekend.

As the system shifts east, SPC will also likely bump the severe weather threat south & east Friday.

Quiet Deephaven Beach at Lake Minnetonka

Image: Paul Huttner - MPR News

Swimming anyone?

What may have been the longest "swimmable" lake season in Minnesota has come to a crashing halt. A jump into your favorite lake these days will likely trigger gasp reflex and purple lips, not to mention other effects.

After some lakes in southern Minnesota reached nearly 90 degrees this summer and remained swimmable well into September, water temps have plummeted in the past month.

Here is a preview of Mark Seeley's Weather Talk this week.

Topic: Downward trend in temperature

Many observers have reported below normal temperatures so far this month. In northern locations 9 of the first 11 days have been cooler than normal, with many chilly mornings in the 20s F. Embarrass, Hibbing, and Wild River State Park have reported a minimum temperature of just 18 degrees F this month, while Brimson (St Louis County) has fallen to 15 degrees F. If this pattern persists we may see a significantly cooler than normal month in Minnesota for the first time since May of 2011. In addition shallow soil temperatures (4 inch depth) have fallen by 15-20 degrees F or more since the first of the month.

Lake Superior surface water temperatures reached a maximum of 70 to 75 degrees F this summer, but have plummeted several degrees this month. Currently many areas of the lake are reporting surface temperatures in the upper 30s to low 40s F. Other smaller lakes around Minnesota have also seen a decline of surface water temperature. Lake Minnetonka has fallen from the low 60s F at the start of the month to just 50 degrees F late this week. Similarly Mille Lacs has dropped from 59 degrees F to start the month to just 45 degrees F by October 11th. At Lake of the Woods water temperature has fallen from the low 50s F to start October to 39 degrees F on October 11th.

PH