Friday, September 2, 2016

Labor Day weekend snow in the mountains of western Montana while Tropical Storm Hermine impacts the far eastern U.S. Warm and turning more humid in the Northland, dew points nearing 70 by Labor Day

/Issued 4:48 PM CDT, Friday, September 2, 2016/

Source, Weather Prediction Center

Excessive rainfall outlook valid from 7 AM Sunday thru 7 AM Monday.  Source, Weather Prediction Center.

Severe weather outlook for Sunday, September 4.  Source, Storm Prediction Center.

We've got snow in the mountains of western Montana this Labor Day weekend while on the east coast its slow moving tropical system Hermine which will produce lots of rain, wind and high waves near the coast.

Source, National Hurricane Center.  5 day forecast track of Hermine, a slow mover!

Tonight's low temperature forecast.

Saturday's high temperature forecast.

Weather Summary for northeast Minnesota and northwest Wisconsin
Date:  September 2, 2016

A nice start to the Labor Day holiday weekend -- Partly to mostly sunny skies ruled today with highs in the low to mid 70s which is very close to average for early September.  Dew points have come up just a bit today with values in the 50s over the Northland.  Winds were out of the south or southwest at 10 to 20 mph.

Forecast Discussion for northeast Minnesota and northwest Wisconsin

...Short Term Forecast...

Tonight (September 2)

Quiet weather continues under a clear to partly cloudy sky.  Patchy fog is possible late.  Lows will be in the 50s with 40s possible in the typical cold spots.  Winds will be out of the south or southwest at 5 to 15 mph.

Saturday (September 3)

Dry weather on Saturday with highs in the 70s.  Lows will be in the 50s to lower 60s.  Expect partly cloudy skies with southerly winds at 10 to 20 mph.

...Extended Forecast...

Sunday (September 4)

Will start to get some changes in the weather late this weekend as a cold front works its way into northwestern Minnesota -- Southerly flow continues ahead of this front which will begin to draw a more humid airmass into the Northland starting on Sunday as dew points rise to around 60 degrees or perhaps a little higher.  Elevated instability is also forecast to increase with around 500-1000 j/kg of most unstable cape possible per model guidance.  A very strong S-SW low level jet of 40-55 knots is forecast to develop across much of Minnesota Sunday night which will help in advecting moisture and unstable air into the area.  Scattered showers and thunderstorms are possible in our area Sunday into Sunday night -- Locally heavy rainfall is a distinct possibility as PWATS climb to between 1.50-nearly 2.00".

Highs on Sunday will be in the 70s to lower 80s with lows Sunday night in the 60s.

Labor Day (September 5)

Warm and muggy with occasional showers and thunderstorms.  A cold front will move slowly toward the Northland.  Gusty south winds will persist ahead of this front with dew points on Monday expected to range from 65 to around 70 degrees while high temperatures will be in the 70s and 80s.  A fairly strong CAP should be in place on Monday with 700mb temperatures approaching +12 degrees Celsius.

Forcing associated with the approaching cold front might be enough to initiate showers and thunderstorms especially over northern and western portions of the area -- If thunderstorms can develop they could become severe with plenty of fuel expected to be in place with CAPE possibly exceeding 2000 j/kg.  This combined with 30-40+ knot mid level winds and 100+ knot upper level winds over the northern Plains along with around 30-40 knots of deep layer wind shear could lead to a Labor Day severe weather risk in portions of the Northland.

Forecast for Duluth and Superior

.Tonight...  Mostly clear.  Patchy fog possible late.  Low 50 to 55.  Wind south at 5 to 15 mph.

.Saturday...  Patchy fog early otherwise partly cloudy.  High 71 to 76.  Wind south at 10 to 20 mph.

Normal temperatures for Saturday

High:  70
Low:   51

Sunrise Saturday:  6:32 AM CDT
Sunset Saturday:   7:43 PM CDT