Friday, February 18, 2011

2/18/11: Friday's Weather Report

Issued at 4:57 PM CST, Friday, February 18th, 2011

Hurricane and Tropical Force winds over Lake Superior Today.  Source:  NWS Marquette, MI.

Stannard Rock:  81 mph at 9:30 AM CST
Passage Island:  67 mph at 7:00 AM CST
Rock Of Ages:  62 mph at 1:00 AM CST

Strong wind report for Friday, February 18th, 2011.  Source:  NWS Duluth, MN.

Duluth, MN (Airport)  53 mph
Duluth Sky Harbor Airport:  52 mph
Superior, WI:  46 mph
Eveleth, MN:  47 mph
Ashland, WI:  46 mph
Two Harbors, MN:  45 mph
Brainerd, MN:  45 mph
Grand Rapids, MN:  44 mph
Bigfork, MN:  43 mph
Ely, MN:  43 mph
Grand Marais, MN:  40 mph
International Falls, MN:  37 mph
Hayward, WI:  31 mph

Local storm report.  Source:  NWS Duluth, Minnesota.

3:20 AM CST, 2/18/11:  Esko, MN (Carlton county)  Non-Thunderstorm Wind Damage.  Large pine tree down across Thompson Road.

Power outage in the Duluth Congdon Park Neighborhood...261 Minnesota Power customers were affected by a power outage which was reported at 5:48 AM CST Today.  The cause of the outage was a tree which went down on a power line.  All customers that were impacted had their power restored by 8:30 AM Today.

Forecast Discussion for Northeast Minnesota and Northwest Wisconsin

Today's Weather:

Deep low pressure of 982mb was centered over Eastern Hudson Bay Canada late This Afternoon with strong high pressure of 1036mb over Saskatchewan Province with a ridge extending southeast through the Northern Plains to Iowa.  The pressure difference between the low to our northeast and high to our west resulted in very strong winds and intense cold air advection to occur throughout our area last night and Today.  West-northwest winds increased to 20-30 mph last night with gusts of 30-55 mph, these winds continued into Today.  Temperatures This Afternoon were only in the upper single digits and teens with milder 20s confined to Northwest Wisconsin. 

Today's Upper Level Analysis:

A vigorous upper level low with 150-240 meter 12 hour H5 height falls continued to push east into Quebec Province late Today per RUC model analysis.  A powerful mid level jet of 100-120 knots extended from Western Wisconsin to Western New York while an upper level jet of 120-160 knots stretched from the Central Rockies to the Upper Midwest through the Ohio Valley per RUC model analysis.  A very deep 500mb trough covered the Eastern Pacific and Western U.S. Today per water vapor satellite imagery with a southwest flow in place across the Rockies out ahead of this H5 trough.  Still seeing a tight temperature gradient Today, although much colder air has pushed farther south compared to 24 hours ago.  850mb temperatures as of 4 PM CST ranged from -18 degrees at International Falls, Minnesota to -2 degrees C at Sioux Falls, South Dakota to +4 degrees C at North Platte, Nebraska.

Tonight:

*Wind Advisory* remains in effect until 9 PM CST This Evening for Southern Cook...Southern Lake...Southern St. Louis...and Carlton counties Minnesota.  And for Douglas...Bayfield...Ashland...and Iron counties Wisconsin.

West-northwest winds of 15-30 mph with gusts to 45 mph will persist through mid-Evening before winds subside by late Evening through the Overnight hours, the strongest winds will continue to be found near Lake Superior.  High pressure will be in control of our weather Tonight with clear-partly cloudy skies.  Lows will drop into the single digits below to single digits above zero with some teens below in Northern Minnesota.

Saturday and Saturday Night:

Strong high pressure of 1032-1036mb will be centered to our north-northwest during this period while low pressure heads through the Central Rockies, then into the Western High Plains by Overnight Saturday.  Areas of light snow or flurries could develop at times in Northern Minnesota and Northwest Wisconsin Tomorrow and Tomorrow Night, but accumulations should be light, generally under an inch.  Partly to mostly cloudy skies are forecast Saturday and Saturday Night with highs in the teens and 20s with lows in the single digits and teens, but some sub-zero readings are possible in Northern Minnesota.  Winds will shift to the east-northeast at 10-20 mph during this period.

Extended Forecast:

A significant winter storm is expected to hit Central and Southern Minnesota as well as Western and Central Wisconsin from late Saturday Night through early Monday with snowfall accumulations of 6-12" with localized higher amounts possible.  The trend with Today's model runs is for the surface low to track farther south.  It now appears that the low will move E/NE through Northern Kansas-Southern Nebraska Sunday Morning, passing south of Des Moines, Iowa Sunday Afternoon before reaching the Chicago area by late Sunday Night.  Note:  This storm has some similarities to the December 2010 blizzard, in fact the track of this current storm is almost identical to the early December storm, also a strong arctic high will be in place to our north-northwest which is also similar to the early December blizzard.  There will likely be a sharp gradient in the snowfall late this weekend, but the forecast models are flipping around a bit on where this gradient will setup.

It appears that Northern Minnesota through the Arrowhead will see little if any snow from this storm, with locations from Cass Lake and Walker down along the Highway 2 corridor including the Twin Ports seeing perhaps 1-2" of snow.  Heavier snowfall could spread into the Pine City, Hayward Lakes, and Brainerd Lakes areas with accumulations of up to 6" possible.  There continues to be uncertainty on the exact track of this storm, it's very possible that it may end up tracking slightly more to the south, and if it does this would keep the bulk of the snow south of our local area.

Note:  East-northeast winds will increase Sunday and Sunday Night with sustained winds of 10-25 mph, but gusts could exceed 30 mph closer to Lake Superior.  There is a lot of open water over Lake Superior and the projected wind direction and temperatures are favorable for lake effect snow to develop, the negative to all this is the fact that the arctic high to our north could bring dry air south out over Lake Superior which would virtually shut off or end any lake effect snow that develops.

If lake effect snow becomes more of an issue, or heavier system snow spreads into the Twin Ports on Sunday, then some adverse winter weather conditions would be likely due to a strong E-NE wind and falling snow which would result in very poor visibility due to falling and blowing snow.

High temperatures for Sunday and Monday will be in the teens and 20s with lows Sunday Night and Monday Night in the single digits below to single digits above zero.

5 Day Forecast for Duluth/Superior

*WIND ADVISORY*
Timing:  Until 9 PM CST Tonight.

*WINTER STORM WATCH*
Timing:  Late Saturday Night through Sunday Evening.

.Tonight...  Windy This Evening.  Much colder.  Mostly clear.  Low 1 below to 6 below.  Wind northwest at 15 to 30 mph with gusts to 40 mph.  Winds decreasing to 10 to 20 mph late.  Wind chill values of 10 below to 20 below.

.Saturday...  Partly sunny.  High 17 to 22.  Wind becoming north to northeast at 5 to 15 mph.

.Saturday Night...  Mostly cloudy.  Light snow or flurries possible.  Accumulations under 1".  Low 10 to 15.  Wind east at 10 to 15 mph.

.Sunday...  Breezy.  Mostly cloudy with light snow and flurries.  Accumulations around 1".  High 20 to 25.  East to northeast wind could occasionally gust to 30 mph.

.Sunday Night...  Breezy.  Mostly cloudy with flurries.  Low 7 to 12.  Northeast winds could occasionally gust to 25 mph.

.Monday...  Partly sunny.  Flurries possible.  High 15 to 20.

.Monday Night...  Partly cloudy.  Low zero to 5 above.

.Tuesday...  Partly cloudy.  High 20 to 25.

Normal temperatures for Tomorrow:

High:  26
Low:    7

Sunrise Tomorrow:  7:07 AM CST
Sunset Tomorrow:   5:39 PM CST

Tim