/Issued 3:59 PM CDT, Wednesday, September 25, 2013/
*Rainfall forecast valid thru 7 PM Saturday. Based on the latest model data it looks like Western, Central, and Northern Minnesota will have the greatest chance for heavier rainfall from Friday into Saturday with totals of 0.50-2.00″ possible. Lighter rainfall amounts are expected from the Twin Ports into all of Northwest Wisconsin. (Source, Weather Prediction Center via WeatherBell)
*DENSE FOG ADVISORY*
Source: National Weather Service Duluth, Minnesota
Portions of Northeast Minnesota and Northwest Wisconsin including the North Shore and South Shore of Lake Superior and the I-35 corridor from Duluth to Moose Lake.
7 PM This Evening until 9 AM CDT Thursday.
Counties included in the advisory:
Southern Cook MN
Southern Lake MN
Southern St. Louis MN
Some cities included in the dense fog advisory:
Grand Marais…Lutsen…Silver Bay…Two Harbors…Duluth…Floodwood…Wright…Cloquet…Moose Lake…Superior…Solon Springs…Port Wing…Bayfield…Washburn…Cable…Drummond…Ashland…Mellen…Clam Lake…High Bridge…Hurley…Upson…and Gile.
Dense fog will become widespread This Evening and will continue Overnight and into Thursday Morning. Visibilities will be reduced to less than one quarter mile. If driving, slow down, use your headlights, and leave plenty of distance ahead of you.
*NWS hazards map. The grayish looking color is a dense fog advisory which is valid until 9 AM Thursday.
Today’s Weather Summary for Northeast Minnesota and Northwest Wisconsin
Low pressure of 1001mb was over far Southern Saskatchewan with a couple other lows averaging 996-1001mb over the Rockies. High pressure of 1017mb covered the Great Lakes. If you were away from Lake Superior it was another fine early fall day under sunny to partly cloudy skies. Highs were in the low to mid 70s with southerly winds at 5 to 15 mph. Closer to Lake Superior it was a far different story as east winds led to widespread low cloudiness and fog Today with highs in the 50s and 60s.
Forecast Discussion for Northeast Minnesota and Northwest Wisconsin
Short Term Forecast – Confidence: High.
Tonight (September 25)
Clear to partly cloudy skies will continue Tonight with fog and low clouds common near Lake Superior. Lows will be in the 40s and 50s with south or east winds at 5 to 15 mph.
Thursday and Thursday Night (September 26)
Partly to mostly cloudy skies are expected this period with low pressure remaining to our west leading to a southerly flow of mild air across the Upper Midwest. A few showers might develop by late Thursday Night in Western parts of the area with dry weather continuing elsewhere. Highs Tomorrow will be in the 70s to lower 80s with cooler 50s and 60s near Lake Superior where low clouds and fog may linger most of the day. Lows Tomorrow Night will be in the 50s to lower 60s.
Extended Forecast – Confidence: High.
Friday through Sunday (September 27-29)
Low pressure along with a cold front and upper level trough will be moving through the Upper Midwest from Friday into Saturday. A moist airmass will be in place along and ahead of this system with dew points in the 50s to around 60 degrees with PWATS of 1.00-1.75″. A strong low level jet of 35-50 knots will also develop across the Upper Midwest from Friday into early Saturday.
Rain will affect the entire Northland at times Friday and Saturday with mainly dry weather for Sunday as low pressure exits to our east. Note: The greatest chance for rain on Friday looks like it’ll be over North Central Minnesota down toward the Brainerd Lakes with the least chances over Eastern Minnesota and Northwest Wisconsin. The chance for rain will then increase in Eastern Minnesota and Northwest Wisconsin on Saturday.
Isolated thunderstorms may also occur Friday and Friday Night in the Western-Northern parts of the area with CAPE of around 100-500 j/kg and Lifted Indices of -1 to -3C. Winds aloft and the aforementioned low level jet look strong as well. If the instability was higher the probabilities for severe thunderstorms would likely increase, but right now the amount of instability looks kinda marginal on Friday, so there probably won’t be any severe thunderstorm activity, but this situation will have to be monitored.
High temperatures will be in the 70s and lower 80s on Friday with cooler temperatures along the North Shore of Lake Superior and also in Northern Minnesota. Lows Friday Night will be in the 50s and 60s. Highs on Saturday will also be in the 50s and 60s with lows mainly in the 40s. Highs on Sunday will once again top out in the 50s and 60s.
*Believe it or not the SREF model (15z run) shows the potential for supercell thunderstorms with even a low chance for tornadoes late Friday Afternoon in Northern/Central Minnesota. As I stated above the instability looks pretty weak at the moment so I’m not too concerned about severe weather on Friday, but the shear and winds aloft look strong, should the CAPE increase, then we could be in store for some ‘interesting’ weather Friday PM.
*Wanted to include a few images off the 12z ECMWF from the EUROwx.com website. This is a brand new site from Andrew Revering. He’s offering a free 7-day trial period no strings attached. After that, it’s very affordable at just $8.00 per month. This is my 1st day using this site, I like it so far.
The image below is valid for 1 PM Saturday and shows where rain will be falling early Saturday Afternoon per EURO model.
This image is valid at 7 PM Saturday per 12z ECMWF. Looks kinda rainy Saturday Afternoon/Evening across the Northland.
Long Range Forecast – Confidence: High.
(September 30-October 5)
Early next week looks dry at the moment (30th-1st) Might see a few showers around the 2nd, and possibly again toward the 4th-5th. Near normal temperatures are expected through this period.
5 DAY FORECAST FOR DULUTH/SUPERIOR
*DENSE FOG ADVISORY 7 PM Tonight until 9 AM CDT Thursday*
.Tonight… Fog. Visibilities as low as one quarter mile at times. Patchy drizzle. Low 47 to 52. Wind east to southeast at 5 to 15 mph.
.Thursday… Fog. Visibilities as low as one quarter mile at times. Patchy drizzle. Clearing possible by the Afternoon. High 65 to 70. Wind east to southeast at 10 to 15 mph.
.Thursday Night… Partly to mostly cloudy. Fog possible. Low 50 to 55. Wind southeast at 5 to 15 mph.
.Friday… Scattered showers possible. Mostly cloudy. High 65 to 70.
.Friday Night… Mostly cloudy. Showers possible. Low 53 to 58.
.Saturday… Mostly cloudy. Showers possible. High 60 to 65.
.Saturday Night… Partly to mostly cloudy. Low 40 to 45.
.Sunday… Partly cloudy. High 63 to 68.
Normal temperatures for Today
Sunrise Thursday: 7:01 AM CDT
Sunset Thursday: 6:58 PM CDT