Wednesday, June 16, 2010

*Repost* 1 day before the MN tornado outbreak; 6/16/10: Wednesday's Weather Report

Issued at 2:44 PM CDT, Wednesday, June 16th, 2010

Here are some rainfall totals that occurred around Northern Minnesota and Northwest Wisconsin on Tuesday, June 15th, 2010. Source: NWS Duluth, MN.

Duluth MN (St. Louis County) 0.28"

International Falls MN (Koochiching County) 0.13"

Brainerd MN (Crow Wing County) 0.20"

Hibbing MN (St. Louis County) 0.16"

Cook MN (St. Louis County) 0.26"

Embarrass MN (St. Louis County) 0.20"

Littlefork MN (Koochiching County) 0.19"

Silver Bay MN (Lake County) 1.13"

Bruno MN (Pine County) 0.40"

6 miles West of Sandstone MN (Pine County) 1.10"

4 miles South of Bruno MN (Pine County) 1.08"

9 miles North of Bayfield WI (Bayfield County) 0.26"

Butternut WI (Ashland County) 0.63"

Sarona WI (Washburn County) 0.24"

3 miles West of Pine City MN (Pine County) 2.10" Note: Fell within an hour.

Local storm reports from Tuesday, June 15th, 2010. Source: NWS Duluth, MN.

3:42 PM CDT 6/15/10: 5 miles Southwest of Pine City MN (Pine County) 1.00" diameter hail. Quarter size hail stripping a few leaves off maple trees.

Weather tidbits for Duluth, MN:

Rainfall total from Tuesday: 0.51"
Total for the month: 3.36"
Departure: 1.34" Above Normal

Forecast Discussion for Northeast Minnesota and Northwest Wisconsin

Today's Weather:

Mostly cloudy skies prevailed once again Today, but there has been some breaks for partial sunshine here and there. The dense fog which developed last night burned off by around mid-Morning. No rain was falling anywhere in our local area Today which is a nice change from what has been a very wet June so far. High temperatures Today were generally in the middle 60s to lower 70s with 850 mb temperatures as of 2 PM ranging from +10/+12 degrees C. Some lingering low level moisture remained in place Today as dewpoints were holding in the middle 50s to lower 60s around our area This Afternoon, but PWS have come down from 24 hours ago with Afternoon PWATS around 0.90". Winds Today were a non-factor, generally from the south, north, or east under 12 mph. Surface map as of 2 PM featured an area of low pressure 1006 mb centered just east of Lake Huron. A ridge of high pressure averaging 1016 mb was located across the Upper Midwest. Low pressure averaging 998 mb was centered in Northern Utah with a cold front extending from Central Montana to Northern Utah while a warm front was beginning to take shape from Western South Dakota to Central Kansas.

Today's 500 mb analysis:

The system which was over us on Tuesday was passing through Eastern Canada This Afternoon per water vapor satellite imagery. A temporary upper level ridge (576-582 meters) covered the Upper Midwest Today behind the system to our east per RUC model analysis. The next system to keep tabs on was over the Western U.S. Today as a strong upper level trough/upper low spreads south/east out of the Pacific Northwest along with it's 60 meter 12 hour 500 mb height falls. A strong upper jet (100 knots) was indicated per RUC model from Central Oregon to the Nevada-California state line This Afternoon.


Partly-mostly cloudy skies will be found across Northern Minnesota and Northwest Wisconsin. Some patchy could develop later in the Evening and during the Overnight hours. Lows Tonight will be mainly in the 50s, but some 40s are possible in spots if skies can clear out. A ridge of high pressure will be in control of our weather Tonight as it settles slowly east out of the Upper Midwest. Winds Tonight will be out of the south, north, or east around 12 mph.

Thursday and Thursday Night:

Low pressure over Northern Utah (998 mb) This Afternoon will head N-NE and deepen to around 989 mb. The center of the low is forecast to reach the the Northern Rockies by Thursday Morning, and will then move toward Southern Manitoba Province Thursday Night. A warm front will extend southeast of this low. This warm front is forecast to lift northeast, passing through Northcentral, Eastcentral, and Northeast Minnesota as well as Northwestern Wisconsin from late Thursday Afternoon through Thursday Evening. A cold front (acting like a dryline) will surge northeast across Western portions of our area Thursday Evening and through Northeast-Eastern Minnesota by late Thursday Night.

S-SE 850 mb jet of 30-50 knots will be in place out ahead of this system on Thursday and this will help pump plenty of low level moisture north into our area. Dewpoints by Thursday Afternoon and Evening will reach the 60s with some lower 70s even possible especially in Southwest-Southern areas. 850 mb td's are forecast to rise to between +10/+16 degrees C while PWS increase to between 1.50"-2.00"! Note: Of even greater concern is the sharp contrast between the real moist air to the very dry air...This is something we rarely see around the Upper Midwest and it's something more typical for the Central Plains.

Instability is expected to increase Tomorrow and Tomorrow Evening with CAPES ranging from 1000-2500 j/kg while Lifted Indices drop to between -2/-6 degrees C.

A southwesterly mid/upper level jet approaching 70 knots will spread E/NE from South Dakota late Tomorrow and Tomorrow Evening while the Upper Midwest will be in some sort of a diffluence pattern with one area of strong winds aloft passing west-north of our area while another one sets-up over the Central Plains.

The latest SREF model continues to show 30-40 knots of Effective Bulk Shear and 0-6 KM Shear around our area with Helicities ranging from 150 m2/s2-350 m2/s2 which is enough to produce severe weather.

The stage appears to be set for severe weather development for portions of our local area during the late Afternoon/Evening hours.

Scattered showers and thunderstorms should develop Thursday Afternoon and Thursday Evening across Northcentral-Central Minnesota with activity shifting into Northeast-Eastcentral Minnesota and Northwest Wisconsin Thursday Evening into early Friday Morning.

Almost all of our area could see isolated severe thunderstorms late Tomorrow-Tomorrow Evening with large hail and damaging winds being the main threats along with heavy rain and dangerous lightning!

The greatest threat for supercells and possible tornadoes appears to be setting up from Cass and Crow Wing Counties in Minnesota, possibly into portions of Aitkin and Pine Counties as well. Timing: 5 PM-9 PM. The threat for supercells and possible tornadoes will also extend farther south into Central Minnesota and back into Western Minnesota, along the Interstate 94 corridor.

Persons throughout Northern Minnesota and Northwest Wisconsin should keep up to date with the latest weather information via NOAA weather radio Thursday Afternoon and Thursday Evening as severe weather and or tornado watches/warnings may be needed for some portions of our area.

Partly-mostly cloudy skies are expected for Tomorrow and Tomorrow Night with highs in the 70s and 80s, except 50s and 60s closer to Lake Superior. Lows Tomorrow Night will be in the 50s and 60s.

Winds will be out of the south or east on Thursday at 10-25 mph with a few higher gusts possible. Winds Thursday Night will shift from the south/east to the southwest at 15-35 mph.

Extended Forecast:

Strong area of low pressure will be passing by to our northwest-north on Friday. A cold front attached to this low will be pushing through the Arrowhead of Minnesota and Northwest Wisconsin on Friday. A few showers or thunderstorms are possible in both those areas Friday Morning until the front moves through. Strong southwest winds with gusts up to 35 mph will affect our local area on Friday while high temperatures reach the 70s and 80s. Winds should subside Friday Night with lows in the 50s to around 60 degrees. A few showers could develop Friday Afternoon or Friday Night across far Northern Minnesota. Saturday and Saturday Night look dry at this time across Northern Minnesot and Northwest Wisconsin with highs mainly in the 70s with lows in the 50s.

5 Day Forecast for Duluth/Superior

.Tonight... Partly to mostly cloudy. Patchy fog possible late. Low 50 to 55. Wind variable around 12 mph.

.Thursday... Breezy. Partly sunny. Afternoon showers or thunderstorms possible. High 68 to 73 but cooler near Lake Superior. Wind east to southeast at 15 to 25 mph. Chance of rain 20%.

.Thursday Night... Breezy. Scattered showers and thunderstorms during the Evening. A few storms could be severe. Low 55 to 60. Wind south to southeast at 10 to 20 mph, becoming south to southwest at 15 to 25 mph by Midnight. Chance of rain 40%.

.Friday... Windy. Partly cloudy. High 80 to 85.

.Friday Night... Partly cloudy. Low 55 to 60.

.Saturday... Partly cloudy. High 73 to 78.

.Saturday Night... Partly cloudy. Low 52 to 57.

.Sunday... Partly sunny. High 70 to 75.

Normal High Temperature Today 71 degrees

Normal Low Temperature Today 49 degrees