Tuesday, May 16, 2017

Risk for strong/severe storms this evening in parts of northwest Wisconsin. More rain on the way Wed-Thu AM (Ending as a rain/snow mix?) Flash Flood Watch for parts of NW WI; Tornado Watch this evening for NW WI

/Issued 5:35 PM CDT, Tuesday, May 16, 2017/

Source:  http://www.spc.noaa.gov

Excessive Rainfall Outlook valid through 7 AM Wednesday.  Source:  http://www.wpc.ncep.noaa.gov

Note:  On the two maps below the Yellow area represents a Slight risk of flash flooding; Green area is a Marginal risk of flash flooding.

Excessive Rainfall Outlook valid 7 AM Wednesday through 7 AM Thursday.  Source:  http://www.wpc.ncep.noaa.gov

Source:  https://www.weatherbell.com/

First half of May 2017 climate stats -- Most of the Northland has had below to near normal temperatures so far this month.  Source:  http://mrcc.isws.illinois.edu

First half of May precipitation departure map.  The majority of the Northland had a drier than average first 15 days of the month.  Source:  http://mrcc.isws.illinois.edu

May 1-15, 2017 climate stats for Duluth, Minnesota (Airport location)

Average temperature:  49.1 degrees
Departure:  +0.1 degree above normal

3 days with a high temperature of at least 70 F
1 day with a low temperature of 32 F

Total precipitation:  0.61"
Departure:  -0.90" below normal

1 thunderstorm day

24 hour rainfall totals from around the Northland
Source:  http://mesowest.utah.edu

Note:  Totals listed below are through 5 PM today, May 16.

Saginaw, MN:  1.57 in
Duluth, MN (Airport)  1.21 in
Moose Lake, MN:  0.87 in
McGregor, MN:  0.75 in
Hayward, WI:  0.74 in
Two Harbors, MN:  0.72 in
Barnes, WI:  0.55 in
Brainerd, MN:  0.52 in
Minong, WI:  0.49 in
Washburn, WI:  0.48 in
Chisholm-Hibbing, MN:  0.48 in
Glidden, WI:  0.46 in
Effie, MN:  0.45 in
Clam Lake, WI:  0.43 in
Pine River, MN:  0.41 in
Ely, MN:  0.37 in
Silver Bay, MN:  0.35 in
Phillips, WI:  0.34 in
Hinckley, MN:  0.31 in
Isabella, MN:  0.18 in
Grand Marais, MN:  0.16 in
Walker, MN:  0.15 in
Littlefork, MN:  0.11 in
International Falls, MN:  0.10 in

Weather Synopsis

A lot of weather to talk about as an active weather pattern remains in place for a while longer.

An area of rain with isolated thunderstorms moved northeast through parts of the Northland this morning -- Late this afternoon there was a warm front extending from east central Minnesota into northern Wisconsin with a cold front approaching from the west.

Instability and wind shear has maximized near the warm frontal boundary in northwest Wisconsin and far eastern Minnesota late this afternoon with meso-analysis showing CAPE of 500-2500 j/kg with 40-55 knots of deep layer shear along with 25-35 knots of 1km shear and Storm Relative Helicity values of 200-300 m2/s2.

Temperatures have warmed into the 70s to around 80 degrees this afternoon along and south of a line from Hinckley to Solon Springs with dew points in the mid 50s to low 60s while farther north temperatures were generally in the 50s and 60s.

*The greatest potential for strong to severe thunderstorms this evening will be over portions of northwest Wisconsin down into Pine County in eastern Minnesota -- This is where the best combination of shear and instability and where the warm front is located.  Primary threats from thunderstorms this evening will be hail and strong wind gusts, there is also a chance for an isolated tornado especially down around the Hayward Lakes area.

*Northeast Minnesota will have some rain showers at times this evening but the severe weather is expected to remain a little further to the south.

*Will see the warm front get overtaken by the approaching cold front tonight, this boundary won't move much through Wednesday evening as it sets up from southern Minnesota to north central Wisconsin...This front will finally get a nice shove to the S/E Thursday thanks to a strong area of low pressure which will lift NE along said front (Tracking from western Kansas to south central Wisconsin)

*A couple more rounds of rain are expected in east central Minnesota and northwest Wisconsin from this evening through Thursday morning.  Heavy rainfall is possible at times which may lead to flash flooding particularly over portions of northwest Wisconsin.

*Scattered thunderstorms are also possible Wednesday in northwest Wisconsin although the potential for severe weather isn't as high tomorrow as it is this evening.

*By early Thursday morning it's not entirely out of the question that it could turn cold enough for the rain to mix with a little snow before precipitation ends -- If this happens the most likely area for it to occur would be away from Lake Superior in northern Wisconsin.

Forecast for Duluth and Superior

Event:  *Dense Fog Advisory*
Timing:  Until 10 PM tonight

.Tonight...  Fog and drizzle with a few showers mainly early.  Lows in the 40s.  Wind east at 10 to 15 mph becoming variable around 10 mph.

.Wednesday...  Turning windy.  Mostly cloudy with occasional showers.  Fog and drizzle also possible.  Highs in the 50s.  Wind east increasing to 15 to 25 mph with higher gusts possible during the afternoon.