Issued at 2:12 PM CDT, Tuesday, August 3rd, 2010
Forecast Discussion for Northeast Minnesota and Northwest Wisconsin
A very warm day around our area as high temperatures soared into the middle 80s to around 90 degrees south of the Iron Range with upper 70s to lower 80s common west-north of the Iron Range. Very muggy air covered Northwest Wisconsin and Eastcentral Minnesota Today where Afternoon dewpoints were in the upper 60s to lower 70s, but drier air with dewpoints in the low 60s were beginning to push south/east out of Northern Minnesota This Afternoon. A weak surface trough (more of a dewpoint front) has been moving southeast across Northeast-Eastcentral Minnesota This Afternoon, this boundary has kicked off isolated showers and thunderstorms at times Today in the Arrowhead of Minnesota and adjacent areas of Northwest Lake Superior and Southern Ontario Province Canada...A few of these storms northwest and north of Lake Superior have turned severe Today. There is sufficient instability in place This Afternoon near that trough in Northwest Wisconsin/Eastern Minnesota to produce isolated convection, latest meso-analysis shows that CAPES have increased to 1000-2000 j/kg in those above mentioned areas while Lifted Indices have decreased to between -2/-5 degrees C. There is also more then enough Effective Bulk and 0-6 KM SHEAR in place to support organized convection, but so far nothing much has happened as this surface trough moves through.
Today's Upper Level Analysis:
Water vapor satellite imagery and RUC model analysis indicates that a west-southwest flow aloft was in place Today over the Upper Midwest. An upper level disturbance was moving east through Central Ontario Province Today while a larger 500 mb low/upper level trough digs south/east out of Northwestern Canada.
Dewpoints will lower across our area through the night as somewhat drier air continues to advect south-east from Northern Minnesota behind a trough which will exit to our southeast This Evening. Spotty showers or thunderstorms could still develop This Evening mainly in Northwest Wisconsin and Eastern Minnesota, but widespread convection and severe weather is not expected at this time. Lows Tonight will be in the 50s and 60s with winds out of the north or west under 20 mph, skies will be partly to mostly cloudy.
Wednesday and Wednesday Night:
An area of high pressure will build east from the Northern Plains to the Upper Midwest early Wednesday while a cold front drops south out of Southern Ontario Province Canada. This boundary combined with some lingering moisture and weak instability could cause spotty showers or thunderstorms around Northern Minnesota and Northwest Wisconsin Tomorrow and Tomorrow Evening. Severe weather is not expected, however, but brief heavy downpours, occasional lightning strikes, wind gusts to 35 mph and small hail could occur in the strongest storms...Highs on Wednesday will be in the 70s and 80s with partly-mostly cloudy skies. Lows Tomorrow Night will be in the 50s to around 60 degrees with partly-mostly cloudy skies. Winds during this period will be out of the north or west at 10-25 mph.
Another cold front will drop south through our area on Thursday as an upper level low heads into Hudson Bay/Northern Ontario Province Canada. A few showers are possible across our local area on Thursday with highs mainly in the 70s. Lows Thursday Night will drop into the 40s and 50s as a cooler airmass pushes south from Central Canada. Friday and Friday Night look dry at this time with highs in the 60s and 70s with lows mainly in the 50s.
Latest long range model guidance indicates that the weather pattern will change once again starting this weekend and possibly lasting through next week as a zonal or southwest flow aloft develops across the Upper Midwest. Hot temperatures will linger to our southwest-south during that period while some low pressure disturbances pass through the Northern Plains/Upper Midwest on occasion bringing with them a chance for showers/thunderstorms and possibly some severe weather and or heavy rainfall.
5 Day Forecast for Duluth/Superior
.Tonight... Partly cloudy. Low 60 to 65. Wind west to northwest at 10 to 20 mph.
.Wednesday... Partly sunny. Afternoon showers or thunderstorms possible. High 78 to 83. Wind west at 10 to 20 mph. Chance of rain 30%.
.Wednesday Night... Showers or thunderstorms possible early, otherwise partly cloudy. Low 55 to 60. Wind northwest at 10 to 20 mph. Chance of rain 30%.
.Thursday... Partly sunny. High 73 to 78.
.Thursday Night... Mostly clear. Low 50 to 55.
.Friday... Partly cloudy. High 73 to 78.
.Friday Night... Partly cloudy. Low 55 to 60.
.Saturday... Showers or thunderstorms possible. Partly sunny. High 75 to 80. Chance of rain 20%.
Normal High Temperature Today 76 degrees
Normal Low Temperature Today 55 degrees