Sunday, July 3, 2016

July 3, 2016: Pleasant tonight; Near 80 and slightly more humid Monday; Risk of a few showers/t-storms during the afternoon-evening

/Issued 8:00 PM CDT, Sunday, July 3, 2016/

Here are three short term computer models valid for early Monday evening.

WRF-ARW likes the idea of a line of thunderstorms pushing southeast through the Twin Ports between 6-8 PM Monday.  Source,

NWS Duluth WRF model also has a line of storms affecting the Twin Ports around 7 PM Monday.

WRF-NMM is the least aggressive model showing only a few storms across northern Minnesota Monday evening; All of this activity would remain north of Duluth.  Source,

A few strong to severe thunderstorms are possible on the Fourth of July across northern Minnesota with a marginal risk of severe thunderstorms covering that portion of the state Monday.  Source, WSI; Storm Prediction Center.

Low temperature forecast for tonight.  Source, National Weather Service Duluth, Minnesota.

High temperature forecast for Monday.  Source, National Weather Service Duluth, Minnesota.

Last week's temperature departure map.  Below average in most of the Northland with one small area that had near or above average temperatures from Two Harbors and Duluth east into extreme northwest Wisconsin.

Last week's precipitation departure map.  Near or above average precipitation in far northeast Minnesota and in portions of northwest Wisconsin with below average precipitation in most of north central Minnesota.

Temperature and precipitation report for Duluth, Minnesota (Airport location)

June 26-July 2, 2016

High temperatures:

6/26:  80 F/+6 degrees above normal
6/27:  65 F/-9 degrees below normal
6/28:  73 F/-1 degree below normal
6/29:  79 F/+5 degrees above normal
6/30:  73 F/-2 degrees below normal
7/1:  74 F/-1 degree below normal
7/2:  75 F/Normal

Low temperatures:

6/26:  58 F/+6 degrees above normal
6/27:  56 F/+3 degrees above normal
6/28:  47 F/-6 degrees below normal
6/29:  53 F/Normal
6/30:  53 F/Normal
7/1:  45 F/-9 degrees below normal
7/2:  50 F/-4 degrees below normal

Total precipitation:  0.53"
Normal:  1.06"
Departure:  -0.53" below normal

Weather Summary for NE Minnesota and NW Wisconsin
Date:  July 3, 2016

Another beautiful summer day under a partly to mostly sunny sky.  Highs were in the 70s to lower 80s with southerly breezes at under 15 mph.  Note:  Winds closer to Lake Superior have been out of the east today but were generally light, and with water temperatures now into the 60s at the head of the lake and into the 40s further out over Lake Superior, the lake breeze is certainly not as potent as it was just a few weeks ago.

Forecast Discussion for NE Minnesota and NW Wisconsin

Confidence:  Medium to High.

Tonight (July 3)

Clear to partly cloudy with a few isolated showers possible in extreme northern Minnesota.  Lows will be in the 50s and 60s with 40s possible in the typical cold spots in northern Wisconsin.  Winds will be out of the south at 5 to 15 mph.

Monday and Monday night (July 4)

Slightly more humid weather on the way for the 4th of July as dew points climb into the 55-65 degree range.  Highs are expected to be in the 70s and 80s along with partly to mostly sunny skies.  Low temperatures Monday night will be in the 60s.  Winds will be out of the south or southwest at 10 to 20 mph.

A frontal boundary will be over the northern Plains tomorrow with a more unstable airmass developing ahead of this front with CAPE of around 1000-2000 j/kg across the Northland.

A few showers and thunderstorms will be possible tomorrow in northern Minnesota -- The threat of a few storms will then spread farther south/east for Monday night.  Should storms develop they will be able to tap into a decent amount of instability along with around 30-35 knots of shear, this combined with 30-40 knot winds in the mid levels of the atmosphere and 80 knot upper level winds to our northwest will support a risk of isolated strong to severe thunderstorms Monday afternoon or evening primarily in northern Minnesota.  Lightning and heavy downpours are possible in any storm with stronger storms also capable of producing gusty winds and hail.

Note:  There is conflicting model data for Monday with at least two short term models showing scattered storms or a line of storms pushing south/east through the Twin Ports between 5-8 PM while a few others keep any thunderstorm activity well to the northwest of Duluth through Monday evening.

...Extended Forecast...

Confidence:  Medium.

A west-southwest flow aloft will be in place from mid to late week; Moist and unstable air will be found Tuesday through Thursday especially across central and southern Minnesota with a somewhat less moist/unstable airmass farther north over the Northland.  Low pressure disturbances are expected to move east through the northern Plains and Upper Midwest from Wednesday through Friday which will lead to a couple rounds of showers and thunderstorms in parts of east central Minnesota and northwest Wisconsin.

Daytime highs are forecast to be in the 70s and 80s on Wednesday cooling to the 60s and 70s Thursday and Friday.

Forecast for Duluth and Superior

Tonight - Mostly clear.  Low 58 to 63.  Wind south around 12 mph.

Fourth of July - Partly to mostly sunny.  High 77 to 82.  Wind south to southwest at 10 to 20 mph.

Monday night - Partly to mostly cloudy.  Isolated showers and thunderstorms possible.  Temperatures in the 70s during the evening with a southwest wind at 10 to 20 mph.

Normal temperatures for Monday

High:  75
Low:  54

Sunrise Monday:  5:21 AM CDT
Sunset Monday:   9:05 PM CDT