Saturday, May 29, 2010

5/29/10: Saturday's Weather Report

Issued at 2:36 PM CDT, Saturday, May 29th, 2010

Weather History:

On this date in 1986... A record high temperature of 87 degrees occurred at Duluth, MN.

On this date in 1984... A record low temperature of 29 degrees occurred at Duluth, MN.

Note: Scattered showers and isolated thunderstorms tracked east-southeast through Northern areas of Minnesota on Friday. Here are some rainfall totals that occurred up in that area. Source: NWS Duluth, MN.

International Falls MN (Koochiching County) 0.28"

Cook MN (St. Louis County) 0.14"

Littlefork MN (Koochiching County) 0.43"

3 miles East of Orr MN (St. Louis County) 0.21"

Forecast Discussion for Northeast Minnesota and Northwest Wisconsin

Today's Weather:

Debris clouds (high level cirrus) have been pushing east across Northern areas of Minnesota Today as strong to severe thunderstorm clusters have been roaming across Southern portions of Saskatchewan, Manitoba, and Ontario Province Canada Today. The remainder of our area saw mainly sunny skies Today. High temperatures were mainly in the low to mid 80s Today across our area with a few locales in Western/Southern areas (Brainerd, Pine River, Hinckley, and Siren) nearing 90 degrees This Afternoon. The cool spot continued to be found at the head of Lake Superior and up the North Shore of Lake Superior where highs Today stayed in the mid 50s to around 60 degrees. 850 mb temperatures as of 2 PM were right around +17 degrees C in Northern Minnesota and Northwest Wisconsin. Dewpoints This Afternoon were running in the 40s and lower 50s with PWS from 0.80"-0.90". Winds Today were out of the south or east at 10-20 mph. Surface map This Afternoon featured low pressure of 1004 mb centered in Northern North Dakota near Minot. A cold front attached to this low extended south through the Central Dakotas while a stationary front was in place across far Northern Minnesota.

Today's 500 mb analysis:

Upper level ridge (582 meters) continued to cover areas from the Upper Midwest through the Central and Southern Plains, east through the Western/Central Great Lakes and south through the Ohio Valley per RUC model analysis. An upper level low (576 meters) was centered in Central Mississippi Today with little movement noted with this system per water vapor satellite imagery. A northwest flow aloft was in place from Eastern Canada through the Northeast U.S. Today while a fairly vigorous upper level trough inches slowly east out of the Northern/Central Rockies. An upper level low (558 meters) embedded within this H5 trough covered areas of Eastern Alberta/Western Saskatchewan Province Canada Today while a rather strong upper level jet (90-120 knot winds) was in place from Eastern Utah, north-northeast through Central Montana.

Tonight:

Clear-partly cloudy skies will be found in Northern Minnesota and Northwest Wisconsin. The frontal boundary in far Northern Minnesota will move little through the night while the cold front across the Central Dakotas heads east toward Western areas of Minnesota by dawn. Scattered showers and thunderstorms will develop Tonight near the cold front to our west, some of this activity could move into Western parts of our area Overnight, generally west of a line from International Falls to Leader. Lows Tonight will be in the 50s and 60s with 40s near Lake Superior. Winds will be out of the south or east at 10-20 mph.

Sunday and Sunday Night:

Low pressure is forecast to move from it's current position which was Northern North Dakota to the border of Southern Ontario Province/far Northern Minnesota on Sunday, this low will then exit to our northeast by Sunday Night. A cold front attached to this low will pass east through our local area Sunday and Sunday Evening.

The cold front is forecast to move through Northern Minnesota from mid-Morning Sunday to early Sunday Afternoon. The cold front is forecast to pass through Northeast-Eastcentral Minnesota around mid Afternoon Sunday with the cold front passing through Northwestern Wisconsin late Sunday Afternoon and Sunday Evening.

The airmass along and ahead of this front will consist of dewpoints in the 50s to lower 60s with 850 mb td's ranging from +8/+14 degrees C. PWS will range from 1.00"-1.50".

The atmosphere will become marginally unstable by Sunday Afternoon/Evening mainly in Northwest Wisconsin, Northeast Minnesota and far Eastern Minnesota with CAPES generally ranging from 500-1250 j/kg, highest values in Northwest Wisconsin with Lifted Indices of zero/-2 degrees C.

Low level jet looks weak along and ahead of the cold front on Sunday with speeds generally around 20-25 knots, winds aloft are forecast to range from 25-40 knots while a rather potent upper level jet with wind speeds up to 90 knots pushes east out of the Northern Plains into the Upper Midwest by Sunday Afternoon-Evening. 0-6 KM Bulk Shear is forecast to range from 25-35 knots Sunday Afternoon with Effective Bulk Shear <30 knots per SREF model.

There should be enough moisture and instability in place to generate some showers or thunderstorms Sunday and Sunday Evening as the cold front moves through, the upper jet approaching from the west should also help with some forcing which should allow some additional precipitation to break out behind the cold front.

Rain that does develop should remain scattered the way it looks now with most locations having a 1-3 hour window where they may see some rain. Precipitation amounts are forecast to remain under 0.10", but any thunderstorm that develops could drop locally higher amounts.

Severe potential continues to look low across our area Sunday Afternoon-Evening with the main threat from any thunderstorm being dangerous lightning strikes and brief heavy downpours and possibly some small hail under one half inch in diameter and gusty winds to 40 mph.

Partly sunny-mostly cloudy skies are expected on Sunday with high temperatures in the 70s and 80s in Northwest Wisconsin with mainly 70s in Northern Minnesota. Lows Sunday Night will be in the 40s and 50s. Winds on Sunday will be out of the south or west at 10-20 mph with northwest or west winds Sunday Night at 10-20 mph.

Extended Forecast:

A new cold front will drop southeast across Northern Minnesota-Northwest Wisconsin Monday Afternoon through Tuesday Morning. This next disturbance will bring another risk for a few showers or thunderstorms to our local area Monday into early Tuesday, this next system looks quite similar to Sunday's with most locations having about a 1-3 hour period where they could see some rain. Severe threat looks low on Monday with minimal instability and moisture forecasted by the models (CAPES generally under 500 j/kg with Lifted Indices around zero degrees C) with dewpoints generally in the 40s to lower 50s. Winds aloft look stronger on Monday compared to Sunday, however, so if the instability and moisture end up being higher than expected, then we may be dealing with an isolated severe weather risk across Northern-Eastern Minnesota Monday Afternoon-Evening.

Tuesday and Tuesday Night look mainly dry at the the moment across Northern Minnesota and Northwest Wisconsin. The next chance for some rain will come around the middle of next week as low pressure pushes northeast from the Central Plains.

High temperatures Monday and Tuesday will be in the 60s and 70s with lows in the 40s and 50s Monday Night and Tuesday Night.

5 Day Forecast for Duluth/Superior

.Tonight... Clear to partly cloudy. Low 53 to 58, a little cooler near Lake Superior. Wind east to southeast at 5 to 15 mph.

.Sunday... Variable cloudiness. Scattered Afternoon showers possible, isolated thunderstorms also possible. High 70 to 75. Wind south to southwest at 10 to 20 mph becoming west. Chance of rain 40%.

.Sunday Night... Becoming partly cloudy. Showers possible before 6 PM. Low 45 to 50. Wind west at 10 to 15 mph. Chance of rain 30%.

.Memorial Day... Partly sunny. Afternoon showers or thunderstorms possible. High 70 to 75. Chance of rain 20%.

.Monday Night... Showers or thunderstorms possible during the Evening. Partly to mostly cloudy. Low 48 to 53. Chance of rain 20%.

.Tuesday... Partly cloudy. High 65 to 70.

.Tuesday Night... Partly cloudy. Low 43 to 48.

.Wednesday... Partly to mostly cloudy. Showers possible. High 60 to 65. Chance of rain 20%.

Normal High Temperature Today 68 degrees

Normal Low Temperature Today 44 degrees

Tim