Thursday, May 26, 2011

5/26/11: Thursday's Weather Report

Issued at 3:53 PM CDT, Thursday, May 26th, 2011

*FREEZE WARNING*

The National Weather Service in Duluth, Minnesota has issued a Freeze Warning from 12 AM CDT Tonight until 8 AM CDT Friday for the following counties:  Koochiching MN...Itasca MN...Aitkin MN...Pine MN...Carlton MN...St. Louis MN...Northern Lake MN...Northern Cook MN...Douglas WI...Bayfield WI...Ashland WI...Iron WI...Burnett WI...Washburn WI...Sawyer WI...and Price WI.  Some cities included in the warning are:  International Falls MN...Northome MN...Bigfork MN...Grand Rapids MN...Hill City MN...Aitkin MN...Pine City MN...Hinckley MN...Moose Lake MN...Wright MN...Cloquet MN...Duluth MN...Hibbing MN...Ely MN...Crane Lake MN...Forest Center MN...Superior WI...Solon Springs WI...Port Wing WI...Bayfield WI...Cable WI...Ashland WI...Butternut WI...Upson WI...Hurley WI...Siren WI...Spooner WI...Hayward WI...and Park Falls WI.

*Temperatures will fall into the 20s away from Lake Superior and within a few degrees of freezing near the immediate shoreline.  Unprotected sensitive and young vegetation will be damaged or killed by temperatures well below freezing Tonight.  Some hardy species and landscaping will likely not be harmed.

A freeze warning means sub-freezing temperatures are imminent or highly likely.  These conditions will kill crops and other sensitive vegetation.  Cover tender plants or take them indoors.

*FROST ADVISORY*

The National Weather Service in Duluth, Minnesota has issued a Frost Advisory from 12 AM CDT Tonight until 8 AM CDT Friday for the following counties:  Cass MN...Crow Wing MN...Southern Lake MN...and Southern Cook MN.  Some cities included in the advisory are:  Cass Lake MN...Walker MN...Pine River MN...Brainerd MN...Two Harbors MN...Silver Bay MN...Lutsen MN...and Grand Marais MN.

*Temperatures will fall into the low 30s by early Friday Morning with areas of frost.  Sensitive vegetation should be protected against frost and near freezing temperatures.

A frost advisory means that frost is possible.  Sensitive outdoor plants may be killed if left uncovered.  Cover tender plants or take them indoors.

Low temperature report for Thursday, May 26th, 2011.  Source:  NWS Duluth, Minnesota.

International Falls, MN:  28 degrees
Hibbing, MN:  28 degrees
Grand Marais, MN:  28 degrees
Orr, MN:  28 degrees
Crane Lake, MN:  27 degrees
Bigfork, MN:  28 degrees
Littlefork, MN:  29 degrees
Embarrass, MN:  25 degrees
3 miles east of Orr, MN:  26 degrees
2 miles south of Tower, MN:  26 degrees

Weather History:

On this date in 1992:  A record low temperature of 28 degrees occurred at Duluth, Minnesota.

WEATHER HEADLINES:

-Unseasonably cold temperatures continue Tonight
-Widespread frost/freeze conditions expected by Friday Morning
-Rain threat increases Friday Afternoon/Evening
-Isolated thunderstorm potential Saturday Afternoon
-Memorial Day severe weather threat?

Forecast Discussion for Northeast Minnesota and Northwest Wisconsin

Today's Weather:

High pressure of 1020mb was centered to our north/northeast late Today.  Sunny skies and cooler than average temperatures were common in our area Today with highs in the 50s to around 60 degrees with 40s near Lake Superior.  Winds were variable, or north-east in direction under 15 mph.

Today's Upper Level Analysis:

W-NW H5 flow was in place across the Upper Midwest Today behind an upper level low which was tracking through the Ohio Valley per water vapor satellite imagery.  Powerful upper level winds >130 knots were blasting east from the Central Pacific to the Western U.S. with a potent upper level trough with 90-120 meter 12 hour 500mb height falls covering the Northern Rockies and parts of the Pacific Northwest.

Tonight:

Mostly clear skies will continue in Northern Minnesota and Northwest Wisconsin with lows in the 20s and 30s along with north or east winds under 15 mph.  Widespread frost and freeze conditions are forecast to develop Overnight.

Friday and Friday Night:

A frosty start with some Morning sunshine will give way to increasing cloudiness from west to east as low pressure approaches from the Northern Rockies.  Areas of rain will develop in Western parts of our area between 2-5 PM Friday with rain chances increasing in the Twin Ports, Iron Range, and I35 corridor between 5-8 PM Friday.  Rain will move into Northwest Wisconsin and the Arrowhead of Minnesota after 8 PM Friday.  The threat for rain will then decrease during the Overnight hours of Friday.  High temperatures Tomorrow will be in the 50s with cooler temperatures near Lake Superior.  Lows Tomorrow Night will be mainly in the 40s.  East or southeast winds are forecast during this period at 10-20 mph.

Note:  Rainfall totals for Northern Minnesota and Northwest Wisconsin should be around one quarter inch between Friday Evening and Saturday.

Extended Forecast:

Low pressure will track west-north of our area this weekend.  A weakening warm front and cold front will be moving across the Northland on Saturday.  Instability will increase a bit Saturday Afternoon with CAPES of a few hundred j/kg along with Lifted Indicies of zero to -2 degrees C.  The air aloft will also be quite cold which should help in the development of scattered Afternoon and Evening showers and isolated thunderstorms.  A severe weather risk would probably develop Saturday Afternoon if there was enough warm, moist, and unstable air around our area...Winds in the mid and upper level will be very strong on Saturday, but a lack of warmth/moisture/and instability will result in little or no risk of severe weather.  High temperatures on Saturday will be in the 50s and 60s with lows Saturday Night in the 40s. 

Sunday and Sunday Night, May 29th looks generally dry at this time as one low exits to our northeast while a stronger one takes shape in the Rockies.  A warm front will be developing in the Midwest late this weekend, but this front will remain well to our south until Monday.  High temperatures on Sunday will be mainly in the 60s with lows Sunday Night mainly in the 40s.

Monday and Monday Night, May 30th:  Strong low pressure of around 995mb is forecast to track from the Western High Plains to the Northern Plains.  A warm front extending east of that low will lift north into at least the Southern half of Minnesota while a vigorous cold front sweeps E-NE into the Upper Midwest for Monday Night.  Ahead of this system, a potent 850mb jet from the S-SE >40 knots will pull moist air north into our area with dewpoints by Monday Afternoon-Evening getting into the 50s and 60s for areas away from Lake Superior.  PWS over 1.00" and 850mb td's of +10 to +14 degrees C will also spread north into the area on Monday.  In the mid levels, southwest winds of 60-80 knots will surge northeast out of the Western High Plains.  It's a fairly potent set-up for severe weather, but how far north will the risk extend, and the timing of this system are still somewhat uncertain at the moment as is the potential for a cap which may advect into the Upper Midwest with 700mb temperatures of +10 to +12 degrees C Monday Afternoon and Evening, if this cap develops, then the risk for thunderstorms would hold off until Monday Evening or Overnight Monday.

A few rounds of showers and thunderstorms are possible across Northern Minnesota and Northwest Wisconsin for Monday and Monday Night with Southern portions of our local area having the best chance for severe weather Monday Afternoon or Evening.  Large hail, damaging winds, and a tornado risk could develop in portions of Minnesota on Monday based on lastest model data.

High temperatures for Monday will be in the 40s near Lake Superior with 50s and 60s elsehwere, some 70s are even possible toward the Brainerd Lakes, Pine City, Haward Lakes areas.  Lows Monday Night will be in the 40s and 50s.

5 DAY FORECAST FOR DULUTH/SUPERIOR

*FREEZE WARNING*
Timing:  12 AM CDT Tonight until 8 AM CDT Friday

.Tonight...  Clear and cold.  Areas of frost Overnight.  Low 27 to 32, a little warmer in Downtown Duluth.  Wind east to northeast at 5 to 15 mph.

.Friday...  Increasing cloudiness.  High 50 to 55 but cooler near Lake Superior.  Wind east at 10 to 20 mph.

.Friday Night...  Occasional showers developing between 5-8 PM with showers lingering Overnight.  Mostly cloudy.  Low 38 to 42.  Wind east at 10 to 15 mph.

.Saturday...  Considerable cloudiness.  Scattered showers, especially during the Afternoon.  High 55 to 60.

.Saturday Night...  Mostly cloudy.  Scattered showers, mainly during the Evening.  Low 40 to 45.

.Sunday...  Partly sunny.  High 62 to 67.

.Sunday Night...  Partly cloudy.  Low 40 to 45.

.Memorial Day...  Breezy.  Mostly cloudy.  Occasional showers or thunderstorms.  High 50 to 55 but cooler near Lake Superior.  East winds could occasionally gust to 25 mph.

Normal temperatures for Today

High:  67
Low:  43

Friday's Pollen Forecast:

Tree:    Moderate
Grass:  None
Weed:  None

Sunrise Tomorrow:  5:22 AM CDT
Sunset Tomorrow:   8:50 PM CDT

Tim