Issued at 4:13 PM CDT, Friday, April 30th, 2010
Updated 30 day outlook for May 2010. Issued by the Climate Prediction Center on Friday, April 30th, 2010.
For Duluth: Equal Chances for Below Normal, Above Normal, or Normal Temperatures and Precipitation.
Here are some rainfall totals across Northern Minnesota and Northwest Wisconsin from 7 AM CDT Thursday ending at 7 AM CDT Friday. Source: NWS Duluth, MN.
Duluth MN: 0.03″
International Falls MN: 0.45″
Brainerd MN: 0.23″
Grand Marais MN: 0.50″
Ashland WI: 0.16″
Northome MN: 0.57″
Littlefork MN: 0.48″
Note: A large storm system helped to ignite a round of severe thunderstorms across portions of the Central Plains on Thursday, April 29th, 2010. There were 77 reports of severe weather on Thursday per SPC website. The most concentrated area of severe storms was over Central Kansas, Southeast Nebraska, Northern-Western Iowa, and extreme Southern Minnesota. 5 out of the 77 reports of severe weather were in the form of tornadoes.
Forecast Discussion for Northeast Minnesota and Northwest Wisconsin
Today’s Weather:
Strong low pressure (986 mb) was located near Baudette Minnesota or in the Northwest part of the state late Today with another strong area of low pressure (986) centered in Southeastern Saskatchewan Province Canada. This system is very dynamic and quite large, but the heavier pockets of rain have been on the scattered side during the past 24 hours. Most locations in our local area have only seen a few hundreths to around one quarter inch of rain since Thursday, with two areas of heavier rain with totals around or greater than one half inch falling in far Northern and far Northeast Minnesota with a seperate area occurring in Southeast parts of Northwest Wisconsin, generally affecting Sawyer, Price, Ashland, and Iron Counties.
Scattered thunderstorms did develop This Afternoon in a very strong shear, but low CAPE environment in portions of Northwest Wisconsin with one lone severe thunderstorm affecting Central-Southern parts of Price County WI around 3 PM Today.
Some rain showers have also occurred at times Today across Northern-Eastcentral Minnesota near the advancing occluded front, but with limited daytime heating keeping instability way down, little if any thunderstorm activity has occurred despite strong shear and good forcing in place in these areas.
Skies for the most part were mostly cloudy in Northern Minnesota and Northwest Wisconsin Today with high temperatures ranging from the 60s and 70s in Northwest Wisconsin to the 50s in Northern Minnesota with 40s along the North Shore of Lake Superior. 850 mb temperatures as of 4 PM ranged from +7 to +13 degrees C with the warmest air aloft found in Northwest Wisconsin and Northeast-far Eastern Minnesota. Winds Today were varied from the south to the north, east, and west at 5-15 mph with some higher gusts.
Today’s 500 mb analysis:
(534 meter 500 mb low) was centered in Northwestern North Dakota late Today per RUC model analysis with a broad and potent upper level trough covering the Rockies, Northern Plains, Upper Midwest, and Central Plains Today. A powerful jet stream 100-120 knots continued to streak NE out of the Central Plains Today on the southeast side of the upper low across the Northern Plains.
Tonight:
Strong low pressure averaging 986 mb will track into Southern Manitoba Province during the night. Occluded front extending southeast of this low will continue to lift northeast through Northern/Eastern Minnesota and Northwest Wisconsin This Evening.
Scattered showers will continue This Evening with strong forcing persisting out ahead of the occluded front along with sufficient amounts of moisture to support some showers as dewpoints remain in the 45-55 degrees, PWS from 1.00″-1.40″ and H85 td’s of +8 to +12 degrees C.
A few thunderstorms are also possible This Evening especially in Northwest Wisconsin and to a lesser extent from Northcentral through Eastcentral Minnesota. Instability remains low, however, with CAPES at or below 250 j/kg with Lifted Indices of zero to around -2 degrees C, so despite other favorable parameters in place including high amounts of shear and a strong low/front, the lack of instability should keep any thunderstorm from turning severe This Evening.
Any thunderstorm that does develop could contain some dangerous lightning strikes, brief heavy downpours and possibly some small hail and gusty winds up to 40 mph.
As the occluded front exits to our northeast during the mid-late Evening hours, a dry slot will push in from the southwest which will end any threat for showers across our area during the Overnight hours. Partly-mostly cloudy skies will occur Tonight with lows in the 40s. Winds will shift to the south and west and increase to 10-25 mph Tonight.
Saturday and Saturday Night:
Low pressure averaging 986 mb will be centered to our northwest-north during this period. Gusty southwest winds will be found on the south flank of this storm with wind speeds from 10-25 mph with a few higher gusts possible on Saturday. Cold air aloft spreading into the Upper Midwest around this low could help to ignite a few showers Tomorrow and early Tomorrow Night, mainly across Northcentral Minnesota. Highs Tomorrow will be mainly in the 50s with some spots up North possibly holding in the 40s.
Extended Forecast:
Low pressure will continue to sit to our north on Sunday before it pulls away to our E/NE by next Monday. Cold advection with 850 mb temperatures falling to +2/-4 degrees C will spread south into Northern Minnesota and Northwest Wisconsin for Sunday and Monday which will result in high temperatures holding in the 40s and 50s both days with lows Sunday Night and Monday Night in the 30s to around 40 degrees. Spotty rain showers could develop once again on Sunday with mainly dry conditions Sunday Night into Monday Night.
The first week of May looks like a chilly one across the Upper Midwest with Tuesday being the only day where high temps could reach the 60s, except near Lake Superior. A vigorous area of low pressure will scoot east out of Southwestern Canada during the early to middle part of next week while a cold front trailing southwest of this low drops southeast through the Northern Plains and Upper Midwest on Tuesday-Wednesday. This system could bring some showers as it moves through the area during the Tuesday/Wednesday time period.
Note: Long range model guidance over the past few days has shown another potent storm system moving into the Southern or Central Plains around the latter part of next week, should this system come far enough north, then it could bring some rain and perhaps even some early May snow to portions of the Upper Midwest sometime late next week. Right now though it appears that this storm would remain too far south to give us any precipitation.
5 Day Forecast for Duluth/Superior
.Tonight… Mostly cloudy This Evening with scattered showers. Becoming partly cloudy late and turning breezy. Low 40 to 45. Wind east at 5 to 15 mph becoming southwest and increasing to 15 to 25 mph late.
.Saturday… Windy. Considerable cloudiness. A few showers possible. High 55 to 60. Wind southwest at 15 to 30 mph. Chance of rain 30%.
.Saturday Night… Variable cloudiness. Low 35 to 40. Wind southwest at 10 to 20 mph.
.Sunday… Mostly cloudy. High 48 to 53.
.Sunday Night… Mostly cloudy. Low 35 to 40.
.Monday… Partly sunny. High 50 to 55.
.Monday Night… Mostly clear. Low 35 to 40.
.Tuesday… Partly sunny. High 57 to 62 but cooler near Lake Superior.
Normal High Temperature Today 57 degrees
Normal Low Temperature Today 35 degrees
Tim