Friday, August 27, 2010

8/27/10: Friday's Weather Report

Issued at 3:37 PM CDT, Friday, August 27th, 2010

Weather History:

On this date in 1984... A record high temperature of 92 degrees occurred at Duluth, Minnesota.

On this date in 1986... A record low temperature of 32 degrees occurred at Duluth, Minnesota.

Forecast Discussion for Northeast Minnesota and Northwest Wisconsin

Today's Weather:

Mainly sunny skies with mild temperatures and comfortable humidity continued across the area Today with highs generally in the lower to middle 80s, but cooler 60s and 70s did prevail from Superior and Downtown Duluth up along the North Shore of Lake Superior. Dewpoints This Afternoon were in the upper 50s to lower 60s with PWS around 0.80". Winds Today were out of the south at 10-20 mph with higher gusts away from Lake Superior. Surface map late Today featured an area of high pressure of 1020 mb over Eastern Illinois with low pressure of 998 mb covering the Central Dakotas. A weak surface trough extended from Northwest Wisconsin toward the Western Shores of Lake Michigan.

Today's Upper Level Analysis:

The 500 mb flow has shifted to the west Today per water vapor satellite imagery. An upper level trough covered the Pacific Northwest-Northern Rockies with a southwest flow aloft developing across the Northern Plains and Rockies out ahead of this H5 trough. A core of very hot temperatures was found across portions of the Western-Central Dakotas through the Western High Plains Today with temperatures of 90-105 degrees with 850 mb temperatures of +26/+34 degrees C!

Tonight through Saturday Night:

High pressure to our southeast and low pressure well to our west will keep a southerly flow going over the Upper Midwest with more mild temperatures expected during this period. Lows Tonight and Tomorrow Night will be in the 50s and lower 60s with highs Tomorrow generally in the 80s. Dewpoints during this period should remain in the 50s to lower 60s. Mostly clear skies are forecast through Tomorrow Night with southerly winds at 10-20 mph with higher gusts thanks to a persistent SW 850 mb jet which will vary in speeds from 35-55 knots from Tonight through Tomorrow Night.

Extended Forecast:

A stationary front will be centered well to our west-north for Sunday and Sunday Night while an upper level disturbance lifts N/NE out of Illinois. Looks mainly dry across Northern Minnesota and Northwest Wisconsin on Sunday with highs generally in the 80s with dewpoints in the 50s and 60s. A muggier airmass will creep north into our area from Sunday Night through early next week as dewpoints climb into the 60s to lower 70s while PWS increase to between 1.50-2.00"! A few showers or thunderstorms could develop Sunday Night, mainly in far Northern Minnesota, otherwise it should remain dry with lows mainly in the 60s. A cold front will start to shift south-east into Minnesota Monday and will move through the state on Tuesday the way it looks now. Scattered showers or thunderstorms are possible near this boundary early next week with at least an isolated severe weather and or heavy rainfall risk developing for portions of our local area. High temps on Monday will be in the 70s and 80s with lows Monday Night mainly in the 60s.

The forecast models continue to be at odds for the middle of next week with the latest GFS, NAVY and EUROPEAN models hinting at a dry Wednesday-Thursday around here, while the GEM-GLOBAL model brings a low pressure system toward the Great Lakes with a swath of rain spreading north into parts of our area sometime late Wednesday or on Thursday. Note: The GFS and EUROPEAN models have both trended drier per last few model runs which is a change from prior runs that showed some rain reaching parts of our area Wednesday Evening, then ending during the day Thursday.

5 Day Forecast for Duluth/Superior

.Tonight... Mostly clear. Low 55 to 60. Wind south to southeast at 5 to 15 mph.

.Saturday... Sunny and breezy. High 80 to 85. Wind southwest to south at 15 to 25 mph.

.Saturday Night... Clear. Low 58 to 63. Wind south at 10 to 15 mph.

.Sunday... Mostly sunny. High 80 to 85.

.Sunday Night... Partly cloudy. Low 60 to 65.

.Monday... Humid. Showers or thunderstorms possible. Partly sunny. High 80 to 85. Chance of rain 20%.

.Monday Night... Humid. Showers or thunderstorms possible. Mostly cloudy. Low 63 to 68. Chance of rain 30%.

.Tuesday... Humid. Showers or thunderstorms possible. Mostly cloudy. High 75 to 80. Chance of rain 30%.

Normal High Temperature Today 71 degrees

Normal Low Temperature Today 51 degrees

Tim