Thursday, July 22, 2010

7/22/10: Thursday's Weather Report

Issued at 3:22 PM CDT, Thursday, July 22nd, 2010

Forecast Discussion for Northeast Minnesota and Northwest Wisconsin

Today's Weather:

There's been some showers roaming through our area Today, but the majority of these showers have been on the light side with the exceptions being north of the Iron Range across Southern Koochiching and Northern St. Louis Counties MN and also in Central-Southern Price County WI, those areas did see some heavier showers at times with doppler radar rainfall estimates nearing a half inch or so in some locations. Otherwise skies have been mostly cloudy Today with some breaks for sunshine especially in Northern and Eastern Minnesota. High temperatures Today were mainly in the 70s, but a few locations in Western-Northern Minnesota were close to 80 degrees late Today. Dewpoints This Afternoon were in the upper 50s in far Northeast Minnesota with 60s elsewhere. Surface map as of 3 PM featured a warm front which extended from Northern Iowa to Southern Wisconsin with low pressure of 1006 mb centered in far Western Iowa. A cold front was located over the Eastern Dakotas with low pressure of 1006 mb in Eastern North Dakota.

Today's Upper Level Analysis:

500 mb ridge (5940 meters) covered the Southern parts of the Ohio Valley, Southern U.S., and portions of the Central U.S. Today per RUC model analysis. Fast flow aloft generally from the west continued Today over the Northern tier of the U.S. or on the north side of this ridge. A couple of disturbances were embedded within this W/SW flow aloft, one system was passing through the Central/Southern Great Lakes late Today, another system was heading east through Southern Manitoba Province and the Northern Plains, the final system (strongest one of all) was digging S-SE out of Western Canada into the Pacific Northwest per water vapor satellite imagery.


A warm front will remain south-southeast of our local area while a cold front moves east out of the Red River Valley area of Minnesota. The atmosphere has become slightly unstable This Afternoon in Northern-Western parts of our area with CAPES up to 1000 j/kg along with Lifted Indices of -1/-4 degrees C. The lift associated with the approaching disturbance/front will likely cause scattered showers and thunderstorms Tonight especially west of a line from Crane Lake to Malmo. There is abundant low level moisture in place late Today with dewpoints in the 60s, PWS from 1.40-1.60" and 850 mb td's around +12 degrees C to support a heavy rain threat in Northcentral Minnesota Tonight. The overall severe threat looks pretty low This Evening, but with 0-6 KM Bulk Shear up to 40 knots there is the potential for isolated severe thunderstorms before 10 PM mainly over Koochiching, Itasca, and Cass Counties Minnesota. Large hail up to 1.00" in diameter and damaging wind gusts to 60 mph will be the main threats along with dangerous lightning strikes.

The rest of Northeast-Eastern Minnesota as well as Northwest Wisconsin could see a few showers at times Tonight as an 850 mb warm front remains near these areas through late Tonight while a S/SW low level jet up to 35 knots persists out ahead of the western cold front.

Partly-mostly cloudy skies will be found across our area Tonight with patchy fog possible late, lows will be in the 50s and 60s. Winds Tonight will be out of the south, east, or west under 20 mph.

Friday and Friday Night:

One disturbance exits to our east while a stronger one moves into the Northern Plains on Friday and the Upper Midwest Friday Night. A warm front which extended from Northern Iowa to Central Wisconsin This Afternoon will sink a bit to the south Tonight and Tomorrow before retreating back to the north a bit, but remaining well south of our local area Tomorrow Night. Partly-mostly cloudy skies are expected in Northern Minnesota and Northwest Wisconsin on Friday with high temperatures in the 70s to lower 80s along with west or northwest winds at 10-20 mph. Mostly cloudy skies with lows in the 50s and 60s are forecast Tomorrow Night. The bulk of the heavy rain and any severe threat associated with this next system looks to remain to our south late Tomorrow/Tomorrow Night, but expect some rain showers to overspread our local area especially by Friday Evening/Overnight.

Extended Forecast:

Low pressure along with it's cold front and upper level trough will be passing through the Upper Midwest on Saturday, this system could bring some more showers or isolated thunderstorms to Northern Minnesota and Northwest Wisconsin on Saturday, then a period of dry weather can be expected from Saturday Night through Monday. High temperatures on Saturday will be mainly in the 70s with Sunday's high temps in the 70s and 80s. Low temperatures Saturday Night and Sunday Night will be in the 50s and 60s.

5 Day Forecast for Duluth/Superior

.Tonight... Partly to mostly cloudy. Low 58 to 63. Wind east to southeast at 10 to 20 mph becoming southwest Overnight.

.Friday... Partly sunny. High 75 to 80. Wind west to northwest at 10 to 20 mph.

.Friday Night... Mostly cloudy. Showers possible. Low 55 to 60. Wind variable at 5 to 15 mph. Chance of rain 30%.

.Saturday... Mostly cloudy. Showers possible. High 70 to 75. Chance of rain 30%.

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

.Sunday... Partly cloudy. High 78 to 83.

.Sunday Night... Mostly clear. Low 57 to 62.

.Monday... Partly cloudy. High 82 to 87.

Normal High Temperature Today 77 degrees

Normal Low Temperature Today 55 degrees