Monday, August 15, 2016

August 15, 2016: Mild temperatures the next several days; Showers possible tonight and Tuesday; Risk for strong-severe storms (Damaging winds) later this week; Much cooler temperatures Aug 20-21

/Issued 5:27 PM CDT, Monday, August 15, 2016/

One of the bigger weather stories by late this week and upcoming weekend will be a shot of cooler temperatures that is forecast to spread into the northern Plains, Upper Midwest and central Plains.  I don't think will be breaking any record low temperatures but it will feel a little like early fall especially by Saturday and Sunday, August 20-21.  Daytime highs here in the Northland will likely be in the 60s this weekend which is roughly 5-10 degrees colder than normal for late August, nothing dramatic just a more refreshing airmass after a few days of warm temperatures and somewhat humid weather.

The map below shows the 850mb temperature anomaly for Saturday, August 20.  Source, 12z EUROPEAN model;

Blue and purple colors=Below average temperatures
Yellow, orange and red colors=Above average temperatures

The black line represents the jet stream

Severe weather outlook for Thursday, August 18, 2016.  Source, Storm Prediction Center.

Severe weather outlook for Friday, August 19, 2016.  Source, Storm Prediction Center.

Tonight's low temperature forecast.

Tuesday's high temperature forecast.

Weather Summary for NE Minnesota and NW Wisconsin
Date:  August 15, 2016

Mild temperatures and a little on the humid side but quite a bit of cloud cover across the area today thanks to an upper level disturbance that is moving slowly E/NE out of western Minnesota -- This system has been producing some light rain showers today over western sections of the Northland, mostly west of a line from Walker to Aitkin and Mille Lacs Lake.  Highs today were in the 70s to lower 80s with late afternoon dew points in the mid 50s to low 60s.  Winds today were out of the south or southwest at 10 to 20 mph.

Forecast Discussion for NE Minnesota and NW Wisconsin

Tonight (August 15)

Mostly cloudy skies with showers in parts of the Northland.  Isolated thunderstorms could also develop but severe weather is not expected tonight.  Brief heavy downpours could occur though with PWATS nearing 1.50".  Lows will be in the 50s and 60s with winds out of the south, west or east at 5 to 15 mph.

Tuesday (August 16)

A weak surface low and trough will be moving through the Upper Midwest on Tuesday -- Expect mostly cloudy to partly sunny skies tomorrow with scattered showers and isolated thunderstorms especially during the afternoon-evening hours.  Brief downpours are possible once again but no severe weather is expected.  Any showers or storms that do develop Tuesday should be slow movers.  Highs are forecast to be in the 70s to lower 80s with dew points in the 50s and 60s so quite similar to Monday.

Shower potential should diminish Tuesday night with partly to mostly cloudy skies expected through the night with low temperatures in the 50s and 60s.

Winds on Tuesday will be out of the south, southwest or northwest at 10 to 15 mph.

...Extended Forecast...

Wednesday (August 17)

One of the nicer days this week should be on Wednesday as the Northland will be in between weather systems with one exiting to the east while the next one tracks into the northern Rockies.  Highs on Wednesday should mainly be in the 80s with lows in the 50s and 60s.

Thursday (August 18)

A chance for showers and thunderstorms as a low pressure system, warm front and cold front approach from the west/south...A few of the storms could be strong to severe by the afternoon/evening hours with enough instability, moisture and wind shear in place per current model data.  Winds aloft as well as the low level jet look favorable for stronger storms on Thursday so will see how all things play out in coming days.  Highs on Thursday are forecast to be in the 80s.

*Outlook for the Tall Ships Festival in Duluth*

-Highs in the 80s on Thursday with S/SW winds.  A chance for showers and thunderstorms mainly late in the day and at night.

-Highs in the 70s on Friday with winds turning to the N/NW.  Showers are possible.

-Mainly dry this weekend with highs in the 60s to around 70 degrees.

Forecast for Duluth and Superior

.Tonight...  Mostly cloudy.  Showers possible especially during the late evening and overnight hours.  Low 58 to 63.  Wind south to southwest at 10 to 15 mph becoming variable.

.Tuesday...  Partly to mostly cloudy.  Isolated late afternoon showers possible.  High 77 to 82.  Wind west at 5 to 15 mph.

Normal temperatures for Tuesday

High:  75
Low:  55

Sunrise Tuesday:  6:08 AM CDT
Sunset Tuesday:   8:16 PM CDT