Thursday, June 10, 2010

6/10/10: Thursday's Weather Report

Issued at 3:27 PM CDT, Thursday, June 10th, 2010

A chilly start for some parts of Northern Minnesota and Northwest Wisconsin. Here are some low temperatures from earlier Today. Source: NWS Duluth, MN.

Hibbing MN: 36 degrees

Cook MN: 39 degrees

Hayward WI: 38 degrees

Embarrass MN: 36 degrees

Floodwood MN: 37 degrees

Forecast Discussion for Northeast Minnesota and Northwest Wisconsin

Today's Weather:

Clouds increased sooner than expected across most of our area Today and as a result from this our high temperatures ended up being cooler then what was forecasted yesterday. High temperatures Today were in the mid 50s to mid 60s with 850 mb temperatures as of 2 PM ranging from +7/+13 degrees C from north to south across our area. Warm and moist advection has been occurring throughout our area Today thanks in part to a southerly low level jet of 25-35 knots which extended from the Northern Plains and Upper Midwest, south through the Central Plains This Afternoon. Deeper moisture is starting to spread northeast into our area This Afternoon with PWS as of 2 PM ranging from 0.80"-0.90" in Northeast Minnesota and parts of Northwest Wisconsin with 1.00"-1.30" PWS for the rest of our area. This increase in moisture combined with some F-GEN forcing has resulted in an area of rain This Afternoon over parts of Northern Minnesota, generally affecting the Counties of Itasca, Koochiching, and Northwest St. Louis. Rainfall amounts have been around one quarter inch or less based on doppler radar estimes. A few other showers have been developing at times This Afternoon farther south, around the Brainerd, Cross Lake, Aitkin, Pine City areas in Minnesota as well as in parts of Burnett County in Northwest Wisconsin. A much larger complex of rain and thunderstorms affected areas south of Interstate 94 in Minnesota Today, but this area of rain didn't hit any part of our local area. That area of rain farther south was closer to where the actual warm front was located This Afternoon, which was from Central Nebraska to Central Iowa while several areas of low pressure averaging 998-1008 mb were centered from South Dakota back through the Rockies while an area of high pressure averaging 1016-1018 mb exits off to our northeast/east late Today.

Today's 500 mb analysis:

Southwest upper level low has developed across the Upper Midwest Today per RUC model analysis with water vapor satellite imagery showing a large upper level trough across the Western U.S. and an upper level low over the Pacific Northwest which was turning slowly toward the south/east. Strong upper level winds (100 knots) were found near or just ahead of the upper trough over parts of the Northern Rockies and adjacent areas of Southwest Canada Today per RUC model analysis with a pocket of 60-90 meter 12 hour 500 mb height falls occurring This Afternoon over portions of Nevada/Eastern California.

Tonight:

Low pressure will remain over the Rockies with high pressure off to our north/east. A warm front will extend through Northern Nebraska-Northcentral Iowa Tonight with a 25-40 knot southerly 850 mb jet aimed from the Central Plains where speeds up to 50 knots are possible north through Minnesota. Warm/moist advection will persist through the night across our area even though we will be well north of the warm front, areas of rain and showers will develop at times throughout our area Tonight with the potential for some thunderstorms by late Tonight, mainly in Southern parts of our area where locally heavy rainfall could develop Overnight. The greatest chance for heavy rainfall would be along and south of a Brainerd to Moose Lake Minnesota line, including most of Northwestern Wisconsin. The threat for severe weather looks low around our area Tonight due to a limited amount of instability this far north. Dangerous lightning strikes and heavy downpours would be the main hazards from any thunderstorm. Mostly cloudy skies will be found across our area Tonight with some fog possible as well. Lows Tonight will be in the 40s and 50s with easterly winds at 5-15 mph with higher gusts.

Friday and Friday Night:

A warm front is forecast to extend from Southern Minnesota or the border of Iowa/Minnesota...east-northeast toward Central Wisconsin. This boundary will be the focal point for additional rounds of showers and thunderstorms from time to time during the Friday-Friday Night period. Locally heavy rainfall is possible due to the copious amounts of low level moisture in place...I.E.: PWS of 1.00-1.75", 850 mb td's of +8/+14 degrees C, and dewpoints in the 60s (Southern areas) The severe weather threat is limited for our area due to the main warm front remaining rather far to our south, but there will be increasing amounts of elevated instability with CAPES (around 500-750 j/kg) across parts of Northwest Wisconsin/Eastcentral Minnesota during this period which could lead to an isolated severe thunderstorm with large hail and damaging winds being the main threat along with dangerous lightning and the torrential downpours. Locations from Brainerd toward Moose Lake, including most of Northwest Wisconsin are most susceptible to receiving some heavy rainfall on Friday. Skies for the most part should remain mostly cloudy during this period with areas of fog. Highs Tomorrow will be in the 50s and 60s with lows Tomorrow Night in the 40s and 50s. Winds will be out of the east or north at 10-20 mph.

Extended Forecast:

Model uncertainty looms for this weekend into early next week. The GFS and NAM-WRF models bring another cluster of rain and possible thunder through our area Saturday and possibly lingering into early Sunday, then the GFS model brings another rain making system our way for early next week. Other long range forecast models keep the bulk of any additional rain this weekend into early next week farther south and away from our local area. High temperatures for Saturday and Sunday will be in the 50s and 60s across Northern Minnesota and Northwest Wisconsin with lows both nights in the 40s and 50s.

5 Day Forecast for Duluth/Superior

.Tonight... Mostly cloudy and breezy. Occasional showers developing along with areas of fog Overnight. A thunderstorm also possible late. Low 48 to 53. Wind east to southeast at 10 to 20 mph with gusts to 30 mph closer to Lake Superior. Chance of rain increasing to 70%.

.Friday... Breezy with rain at times. A thunderstorm also possible. Overcast with areas of fog and drizzle. High 53 to 58. Wind east at 15 to 25 mph. Chance of rain 80%.

.Friday Night... Mostly cloudy. Showers possible along with areas of fog and drizzle. Low 48 to 53. Wind northeast at 10 to 15 mph. Chance of rain 40%.

.Saturday... Mostly cloudy. Showers possible. High 60 to 65. Chance of rain 40%.

.Saturday Night... Partly to mostly cloudy. Showers possible. Low 47 to 52. Chance of rain 20%.

.Sunday... Partly sunny. Showers possible. High 60 to 65. Chance of rain 20%.

.Sunday Night... Partly to mostly cloudy. Low 48 to 53.

.Monday... Partly sunny. High 60 to 65.

Normal High Temperature Today 70 degrees

Normal Low Temperature Today 47 degrees

Tim