Wednesday, August 11, 2010

8/11/10: Wednesday's Weather Report

Issued at 3:23 PM CDT, Wednesday, August 11th, 2010

Another round of rain, heavy at times hit portions of Northern Minnesota and Northwest Wisconsin on Tuesday, August 10th, 2010. Here are some rainfall reports from our local area. Source: NWS Duluth, Minnesota.

Duluth MN: 0.56"

International Falls MN: 0.64"

Brainerd MN: 0.36"

Ashland WI: 0.27"

Hayward WI: 0.49"

Cass Lake MN: 0.81"

Cook MN: 0.52"

Kabetogama MN: 1.20"

Northome MN: 0.56"

Littlefork MN: 0.83"

Silver Bay MN: 0.70"

Dixon Lake MN: 1.10"

4 miles South of Bruno MN: 1.55"

Hinckley MN: 1.00"

Winter WI: 1.21"

Butternut WI: 1.10"

Sarona WI: 0.70"

Year to date precipitation totals around the Upper Midwest. Source: National Weather Service

Duluth MN: 21.68"/3.25" Above Normal
Twin Cities MN: 18.85"/0.12" Below Normal
Des Moines IA: 40.93"/>18.00" Above Normal

Weather History:

On this date in 1982...A record low temperature of 37 degrees occurred at Duluth, Minnesota.

Forecast Discussion for Northeast Minnesota and Northwest Wisconsin

Today's Weather:

Warm and muggy day around our area as a weak cold front sags slowly south/east through Northeast-Eastern Minnesota This Afternoon. Plenty of clouds blanketed the area This Morning, but these clouds have been eroding This Afternoon giving way to some partial sunshine which has led to the atmosphere becoming a bit unstable This Afternoon across Northwest Wisconsin and Northeast-Eastern Minnesota. Latest meso-analysis shows CAPE values reaching 1000-2000 j/kg with Lifted Indices from -2/-6 degrees C. Lapse Rates were rather poor, however, and temperatures aloft were quite warm This Afternoon with H7 temps around +10 degrees C with H85 temps around +18 degrees C. So even with the building instability, the warm air aloft has prevented any thunderstorm from developing This Afternoon near the cold front. High temperatures Today ranged from the 70s in Northwest parts of our area with 80s for the rest of us. Dewpoints late Today were in the 60s and lower 70s with heat indicies in some locales nearing 90 degrees late This Afternoon. Winds Today were out of the southwest or north around 15 mph or less.

Today's Upper Level Analysis:

An upper level trough was in place across the Western U.S./Northern Rockies Today per RUC model analysis and water vapor satellite imagery with an upper level low (5700 meters) centered in Northeastern Oregon. Tuesday's system which brought the flooding rains/scattered severe weather to portions of the Upper Midwest was exiting to our east This Afternoon with a west/southwest 500 mb flow continuing in wake of this system over our local area Today.

Tonight:

Isolated showers or thunderstorms remain a possibility This Evening in Northeast-Eastern Minnesota and in Northwestern Wisconsin as a weak cold front/trough continues to push south/east through these areas This Evening. Otherwise for Tonight expect skies to become partly cloudy with areas of fog developing late which could become dense in spots due to all the moisture in place. Lows Tonight will be in the 60s, but a few locales could drop into the 50s. Winds will be out of the southwest or north under 15 mph. Note: Any thunderstorm that does develop This Evening is not expected to be severe, but brief heavy downpours and occasional lightning strikes are possible.

Thursday and Thursday Night:

A warm and humid airmass will remain in place during this period with high temperatures on Thursday mainly in the 80s to around 90 degrees with lows Thursday Night in the 60s to lower 70s. Dewpoints will hold in the 60s to lower 70s Tomorrow and Tomorrow Night. A weak area of high pressure will shift east through the Upper Midwest on Thursday while low pressure and it's warm front and cold front track into the Northern Plains while an upper level trough spreads slowly east out of the Northern Rockies. An unstable airmass will develop across most of our area Tomorrow Afternoon and Tomorrow Night with CAPES forecasted to climb to between 1000-2500 j/kg with Lifted Indices from -2/-5 degrees C. A strengthening low level jet from the south at 25-35 knots will develop over the Upper Midwest during this period and that combined with some forcing associated with that upper trough and low pressure system to our west should cause scattered showers and thunderstorms especially by late Thursday Afternoon or Thursday Night. At this time it looks like the best threat for rain during that aforementioned time period would be west of a line from Ely to Duluth to Pine City. Locally heavy rainfall will be possible once again due to the abundant moisture in place. There is also a risk for a few severe thunderstorms late Thursday Afternoon and Thursday Night from Cass Lake and Walker, down through Brainerd and Aitkin. Large hail and damaging winds are the main threats from any severe weather. Partly-mostly cloudy skies are expected during this period with winds becoming south or east at 10-20 mph.

Extended Forecast:

A cold front will track east through our area from Friday into early Saturday while low pressure deepens as it passes by to our northwest-north this weekend. A warm, moist and unstable airmass will persist along and ahead of the cold front and also out ahead of an upper level trough which will be over the Northern Plains on Friday. Scattered showers and thunderstorms will occur in Northern Minnesota and Northwest Wisconsin Friday and Friday Night with locally heavy rainfall and a few severe thunderstorms possible. High temperatures on Friday will be in the 70s and 80s with lows Friday Night in the 50s and 60s. A few showers or thunderstorms could linger on Saturday, especially in Northern Minnesota and also in Northwest Wisconsin, otherwise expect a slight drop in humidity on Saturday as west winds develop behind an eastward moving cold front. High temperatures will be in the 70s and 80s on Saturday with lows Saturday Night in the 50s to around 60 degrees. The period from Sunday through Wednesday of next week will be dominated by an upper level low across Central Canada with a northwest flow aloft developing across the Upper Midwest. A couple of cold front and upper level disturbances will likely drop south/east through our area and those systems will bring the occasional shower/thunderstorm to the area late this weekend into early next week.

5 Day Forecast for Duluth/Superior

.Tonight... Muggy. Isolated showers possible before 8 PM. Skies becoming partly cloudy with areas of fog. Low 60 to 65. Wind west at 5 to 15 mph.

.Thursday... Humid. Partly cloudy. High 83 to 88 but turning a little cooler closer to Lake Superior later in the day Wind west to southwest becoming southeast at 10 to 20 mph later in the day.

.Thursday Night... Humid. Partly to mostly cloudy. Showers or thunderstorms possible. Low 63 to 68. Wind southeast at 10 to 15 mph. Chance of rain 30%.

.Friday... Humid. Scattered showers or thunderstorms. Mostly cloudy. High 76 to 81. Chance of rain 50%.

.Friday Night... Humid. Scattered showers or thunderstorms. Mostly cloudy. Low 60 to 65. Chance of rain 50%.

.Saturday... Partly sunny. High 75 to 80.

.Saturday Night... Partly cloudy. Low 55 to 60.

.Sunday... Partly sunny. High 70 to 75.

Normal High Temperature Today 75 degrees

Normal Low Temperature Today 55 degrees

Tim