/Issued 3:50 PM CDT, Tuesday, May 28th, 2013/
-Although the greatest risk for severe thunderstorms and tornadoes looks like it’ll remain south of Minnesota the next few days, there still is an isolated risk for severe thunderstorms Wednesday and Thursday in parts of the Gopher state.
– Tomorrow’s risk is mainly for Southern Minnesota, but on Thursday that risk area might shift into Western and perhaps Central Minnesota.
The map below is for Thursday Evening (7pm) 0-1 km Energy Helicity Index per 18z NAM/WRF model.
I’m noticing a trend that would support at least a spotty severe t’storm risk Thursday PM in Westcentral Minnesota. This would be tied with the surface low as well as near a cold front that’ll lift NE into Minnesota on Thursday.
The EHI (Energy Helicity Index) is one of many parameters that are used for severe weather forecasting. Note the green colors in parts of Westcentral Minnesota on Thursday, values around 1 are enough to cause supercells if other ingredients are present, which in this case some other things are decent, others are not so good. Stay tuned.
Today’s Weather Summary for Northeast Minnesota and Northwest Wisconsin
Finally beginning to see the ridge of high pressure which kept the Northland mainly high and dry lately move farther off to our east, the first sign of that is the higher dew point temperatures in our area Today with 40s and even a few 50s showing up away from Lake Superior. High temperatures were mainly in the 60s with a few 70s as well. Cooler 40s were found closer to Lake Superior. Mostly cloudy to partly sunny skies prevailed Today with winds out of the south or east at 10 to 20 mph.
Weather Tidbits:
*So far this month there have been zero thunderstorm days at Duluth, Minnesota. Only 1 thunderstorm day so far this year. Note: Last May had 12 thunderstorm days. The yearly average is 30-35 t’storm days.
Forecast Discussion for Northeast Minnesota and Northwest Wisconsin
Short Term Forecast – Confidence: High.
Tonight (May 28th)
Partly to mostly cloudy skies are expected with a warm front remaining well to our south while an upper level disturbance passes NW of our area. A few showers are possible Tonight, mainly in far Northern Minnesota. Lows will be in the 40s and 50s with south or east winds at 5 to 15 mph.
Wednesday and Wednesday Night (May 29th)
A strong area of low pressure will be centered over the Western High Plains with a warm front lifting slowly north into the Upper Midwest and Western Great Lakes. Moisture and instability will be increasing this period thanks in part to a 30-50 knot southerly low level jet. Dew points away from Lake Superior are forecast to climb into the 50s and lower 60s with CAPE of around 500 j/kg and Lifted Indices of 0 to -3C. Most of Tomorrow should be dry in the Northland, but scattered showers or thunderstorms are expected to develop by late Tomorrow Afternoon or Evening and this threat will linger through the Overnight hours. Not looking for any severe thunderstorms this period, but locally heavy downpours and small hail can’t be ruled out in a few of the storms. Highs on Wednesday will be in the 60s and 70s with cooler temperatures near Lake Superior. Lows Wednesday Night will be in the 50s to lower 60s but it will be cooler near Lake Superior. South or east winds are forecast at 10 to 20 mph.
*Rainfall forecast for Wednesday Evening-Thursday, ending at 7 PM Thursday. Looks like a widespread 0.50-1.00″+ rain totals in Minnesota. (Source, Weather Prediction Center)
Extended Forecast – Confidence: Medium.
Thursday through Saturday (May 30th-June 1st)
A slow moving upper level trough will dominate our weather during this period. Low pressure tied to this whole system is forecast to pass west/north of the Northland while a cold front moves through between Thursday Afternoon and Friday. The threat for occasional showers or thunderstorms looks like it’ll continue on Thursday with more showers possible at times on Friday and Saturday, instability looks lower Friday into Saturday so thunderstorms shouldn’t be much of a problem. However, on Thursday there should be enough instability around to produce at least a few thunderstorms. Highs will be in the 60s and 70s Thursday and Friday and in the 50s and 60s on Saturday. Lows Thursday Night and Friday Night will mainly be in the 50s.
Long Range Forecast – Confidence: Medium.
(June 2nd-6th)
Sunday (2nd) looks dry at the moment as low pressure and upper trough exit to our east. The next system to monitor will be from the 4th-6th, looks a little similar to the current system. Showers are possible next Tuesday-Thursday. Near to below average temperatures are forecast through this period.
5 DAY FORECAST FOR DULUTH/SUPERIOR
.Tonight… Partly to mostly cloudy. Low 40 to 45. Wind east to southeast at 5 to 15 mph.
.Wednesday… Partly sunny. High 69 to 74 but cooler near Lake Superior. Wind southeast at 10 to 15 mph.
.Wednesday Night… Occasional showers or thunderstorms. Mostly cloudy. Low 50 to 55 but cooler near Lake Superior. Wind southeast at 10 to 15 mph.
.Thursday… Scattered showers or thunderstorms. High 60 to 65 but cooler near Lake Superior.
.Thursday Night… Scattered showers or isolated thunderstorms. Low 50 to 55.
.Friday… Scattered showers possible. High 68 to 73.
.Friday Night… Showers possible. Low 45 to 50.
.Saturday… Showers possible. High 55 to 60.
Normal temperatures for Today
High: 66
Low: 44
Sunrise Wednesday: 5:20 AM CDT
Sunset Wednesday: 8:53 PM CDT
Tim
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