Issued at 3:17 PM CDT, Tuesday, July 12th, 2011
-Dry into Wednesday Night
-Lake breeze kicks in either Tonight or by Wednesday Morning
-Couple cool days ahead with Thursday looking like the coolest day
-Prolonged heat wave possible this weekend into most of next week?
-Storm clusters may erupt west-north of the heat late this week into next week
Forecast Discussion for Northeast Minnesota and Northwest Wisconsin
Plenty of clouds across our area Today thanks to a shot of cold air advection. High temperatures because of the clouds stayed in the 60s and lower 70s Today with north or east winds under 15 mph.
Today's Upper Level Analysis:
Deep 500mb low/trough was nearly stationary across the Northeast Pacific/Western Canada/Northwest U.S. areas. Upper level ridge covered the Central-Southern U.S. while in the Northern tier, a W-NW upper level flow was occurring Today per RUC model analysis and water vapor satellite imagery.
High pressure in Southern Manitoba Province This Afternoon will move into Minnesota Tonight. Skies will become clear to partly cloudy with lows in the 40s and 50s. North or east winds are expected under 15 mph.
Wednesday and Wednesday Night:
High pressure will move off to our east during this period. Dry for Wednesday with mostly sunny skies and highs in the 60s and 70s. Partly to mostly cloudy skies are expected Wednesday Night with lows in the 40s and 50s. East winds will develop at 5-15 mph.
Thursday and Friday could be quite ugly near Lake Superior as the marine layer revs up, it's possible that high temperatures won't get out of the 50s near the big lake both those days, there might also be some fog and drizzle to go along with the easterly breeze and cool temperatures. Inland locations in both Northern Minnesota and Northwest Wisconsin will be slightly warmer with highs in the 60s to around 70 degrees for Thursday and into the 70s on Friday. These cool temperatures will be found north of a warm front which is forecasted to remain well to our west-south late this week. Deep moisture and elevated instability will overrun this boundary and may result in a cluster or two of rain and scattered thunderstorms from Thursday into Friday, some of the rain could be heavy at times, but it's uncertain on what areas will be affected by these storm clusters due to differing solutions by the various computer models during the past day or so. Low temperatures Thursday Night and Friday Night will be mainly in the 50s, perhaps a few 60s in Southern areas by Friday Night.
Full fledged heat wave for the Upper Midwest this weekend, possibly lasting through next week. A sprawling ridge of high pressure will build north from the Southern and Central Plains which will force the strongest jet stream winds farther to the northwest. It looks like a hot and muggy weather pattern will set-up for the area and this also holds true near Lake Superior as it appears that a S-SW wind will be able to overcome the marine layer if not on Saturday then by Sunday. Maximum temperatures of 85-95 degrees look likely this weekend (perhaps even a couple degrees warmer on Sunday) Low temperatures may struggle to drop much below 70 degrees especially Sunday Night the way it looks now. To go along with the hot temperatures will be a ton of moisture, dewpoints are forecasted to be in the 60s and 70s this weekend which combined with the excessively high temperatures will lead to heat indices approaching 100 degrees, if not warmer. Couple things that may work against a heat wave for our area would be possible thunderstorm clusters, and the marine layer, which if it doesn't break would keep it cooler near Lake Superior this weekend.
Not much change in the overall weather pattern is seen for next week with a ridge of high pressure to our south and strong jet stream winds to our west-north. Convective complexes with a damaging wind threat may erupt on the edge of the hot/capped airmass, but it's uncertain whether these would impact the Northland or be farther north into Canada.
5 DAY FORECAST FOR DULUTH/SUPERIOR
.Tonight... Decreasing cloudiness. Low 50 to 55. Wind east to northeast at 5 to 15 mph.
.Wednesday... Mostly sunny. High 67 to 72 but cooler near Lake Superior. Wind east at 10 to 20 mph.
.Wednesday Night... Mostly clear. Low 50 to 55. Wind east at 10 to 15 mph.
.Thursday... Mostly cloudy. Occasional rain possible. High 60 to 65 but cooler near Lake Superior. Chance of rain 40%.
.Thursday Night... Mostly cloudy. Showers possible. Low 50 to 55. Chance of rain 30%.
.Friday... Showers or thunderstorms possible. Mostly cloudy. High 60 to 65 but cooler near Lake Superior. Chance of rain 20%.
.Friday Night... Mostly cloudy. Showers or thunderstorms possible. Low 53 to 58. Chance of rain 20%.
.Saturday... Humid. Partly sunny. Showers or thunderstorms possible. High 75 to 80. Chance of rain 20%.
Normal temperatures for Today
High: 76 degrees
Low: 55 degrees
Wednesday's Pollen Forecast:
Sunrise Tomorrow: 5:27 AM CDT
Sunset Tomorrow: 9:01 PM CDT
Note: Duluth/Superior Harbor water temperature as of July 12th, 2011: 60.8 degrees