Friday, October 1, 2010

10/1/10: Friday's Weather Report

Issued at 3:03 PM CDT, Friday, October 1st, 2010

...All headlines issued by the National Weather Service Duluth, Minnesota...

*FREEZE WARNING*

Timing:

2 AM CDT UNTIL 8 AM CDT SATURDAY.

Counties included in the warning:

Koochiching MN...Itasca MN...Central and Northern St. Louis MN...Northern Lake MN...and Northern Cook MN...

Some cities included in the warning:

International Falls MN...Big Falls MN...Northome MN...Bigfork MN...Grand Rapids MN...Hibbing MN...Cotton MN...Embarrass MN...Crane Lake MN...Wales MN...Forest Center MN...and Isabella MN...

Discussion:

Cold high pressure will build southeast from Saskatchewan Province Tonight...Low temperatures are expected to drop into the 25-31 degree range by dawn which will result in a widespread frost and killing freeze in the warning area.

A freeze warning means sub-freezing temperatures are imminent or highly likely.  These conditions will kill crops and other sensitive vegetation.

*FROST ADVISORY*

Timing:

2 AM until 8 AM CDT Saturday.

Counties included in the advisory:

Cass MN...Crow Wing MN...Aitkin MN...Carlton MN...Southern St. Louis MN...Southern Lake MN...and Southern Cook MN...

Some cities included in the advisory:

Cass Lake MN...Longville MN...Leader MN...Brainerd MN...Pine Center MN...Cross Lake MN...Hill City MN...Aitkin MN...McGrath MN...Moose Lake MN...Cromwell MN...Carlton MN...Duluth MN...Floodwood MN...Two Harbors MN...Silver Bay MN...Lutsen MN...Grand Marais MN...Hovland MN...and Grand Portage MN...

Discussion:

Cold high pressure will build southeast from Saskatchewan Province Tonight...Low temperatures are expected to drop into the lower to middle 30s which will result in areas of frost by dawn in the advisory area.

A frost advisory means that frost is possible.  Sensitive outdoor plants may be killed if left uncovered.

Note:  Only 2 days during September 2010 were at or above 70 degrees at Duluth, Minnesota which tied with the years 1926 and 1993 in having only 2 days with high temperatures of at least 70 degrees.  Only 3 years out of the 137 Septembers on record produced 1 day at or above 70 degrees...This includes the years 1907, 1934, and 1972.  No September has ever produced zero days with a 70 degree temperature.  Source:  NWS Duluth, MN.

October 2010 averages for Duluth, Minnesota:

Normal high temperatures in the upper 50s on the 1st drop to the middle 40s by the end of the month.  Normal low temperatures of 40 degrees on the 1st drop to the upper 20s by the 31st.  Normal precipitation is 2.46", and we usually see our first sticking snow this month with 1.5" of snow falling on average during the month of October.

Rainfall report from Wednesday, September 29th, 2010.  Source:  NWS Duluth, Minnesota.

Duluth MN:  0.18"
Grand Marais MN:  0.26"
Hibbing MN:  0.22"
Cook MN:  0.21"
Embarrass MN:  0.25"
3 miles east of Orr MN:  0.19"
Butternut WI:  0.15"
Madeline Island WI:  0.16"
Washburn WI:  0.16"

Weather History:

On this date in 1989 and previous years...A record high temperature of 80 degrees occurred at Duluth, Minnesota.

Forecast Discussion for Northeast Minnesota and Northwest Wisconsin

Today's Weather:

Third cold front this week was moving south/east through our area Today.  This front produced an area of rain This Morning and early This Afternoon from Grand Rapids and Hibbing through the Twin Ports on south toward Sandstone and Hinckley, and then east through Northwest Wisconsin.  This rain area has pushed south out of our area as of mid-Afternoon, but now cold air aloft with 500 mb temperatures of -22/-26 degrees C combined with steepening LAPSE RATES and weak instability (CAPES 100 j/kg and Lifted Indicies around +2 degrees C) resulted in the formation of scattered Afternoon showers across Northeast Minnesota and far Northwest Wisconsin.  Some of these showers have been very heavy for brief periods of time with perhaps some small hail accompaning one area of showers as it drops S/SE through Duluth/Superior as of 3 PM.  Partly sunny to mostly cloudy skies covered the area Today with high temperatures ranging from the lower 60s around the Brainerd Lakes with 40s in far Northeast Minnesota with 50s elsewhere.  Winds Today were north or calm in direction.

Today's Upper Level Analysis:

500 mb flow was amplifying Today with a northerly flow becoming established now over the Upper Midwest as a powerhouse 120-150 knot upper level jet across Eastern Canada combines with an upper level trough dropping south out of Central Canada to help sharpen the upper level pattern.

Tonight:

Strong high pressure of 1032 mb will be centered to our northwest with cold air advection and north winds occurring on the front side of this high.  850 mb temperatures will fall to between zero/-4 degrees C Tonight while low temperatures drop into the 30s with some 20s possible in Northern Minnesota.  Scattered pop-up showers which could contain some small hail and brief heavy downpours will end between 7-9 PM This Evening, then the rest of Tonight will be dry, although some lake effect showers are possible along the South Shore of Lake Superior in Northwest Wisconsin.  Partly to mostly cloudy skies will cover the area Tonight with north winds under 20 mph.

Saturday and Saturday Night:

High pressure of 1032 mb will drop into the Upper Midwest during this period with partly-mostly sunny skies on Saturday and mostly clear skies for Saturday Night.  Some lake effect rain showers could persist Tomorrow Morning along the South Shore of Lake Superior in Northwest Wisconsin.  Highs Tomorrow will be in the 40s and 50s with lows Tomorrow Night in the 20s and 30s.  North winds will continue Tomorrow under 20 mph with variable to calm winds Tomorrow Night.

Extended Forecast:

High pressure will slide off to our south/east by Sunday with a southerly wind developing over the Upper Midwest from Sunday through next Tuesday...High temperatures will be mainly in the 50s on Sunday with 50s and 60s for Monday.  Lows will be in the 30s Sunday Night with mainly 40s expected for Monday Night.

Note:  Widespread frost and a killing freeze is expected for all of our area either Tonight or Saturday Night with some areas seeing two nights of these conditions.

5 Day Forecast for Duluth/Superior

*FROST ADVISORY* IN EFFECT FROM 2 AM UNTIL 8 AM CDT SATURDAY FOR DULUTH.

.Tonight...  A few showers This Evening.  Partly to mostly cloudy.  Areas of frost late.  Low 31 to 36.  Wind north at 10 to 15 mph.

.Saturday...  Variable cloudiness.  High 48 to 53.  Wind north at 10 to 20 mph.

.Saturday Night...  Mostly clear.  Widespread frost and a killing freeze possible.  Low 27 to 32.  Wind variable around 12 mph.

.Sunday...  Mostly sunny.  High 52 to 57.

.Sunday Night...  Mostly clear.  Low 35 to 40.

.Monday...  Mostly sunny.  High 58 to 63.

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

.Tuesday...  Partly cloudy.  High 60 to 65.

Normal High Temperature Today 59 degrees
Normal Low Temperature Today 40 degrees

Tim