/Issued 12:06 PM CDT, Tuesday, August 6, 2013/
-Already seeing a few stronger thunderstorms as of 12:20 PM well south of the Twin Ports with movement toward the east-southeast. Could get a little rough later Today/This Evening around the Brainerd Lakes, Hinckley, Pine City areas, east into Siren, Spooner and the Hayward Lakes area in Northwest Wisconsin. More info. below.
-Severe thunderstorms possible later This Afternoon into mid-Evening south of the Twin Ports.
*Slight risk for severe thunderstorms Today across all but Northern Minnesota and far Northern Wisconsin. (Source, Storm Prediction Center)
At Noon, low pressure of 1006mb was over Southeast North Dakota with a cold front over Western Minnesota and a trough/wind shift line stretching from Westcentral to Southeast Minnesota.
Areas of showers have been developing This Morning in the cool air north of this system across Northern Minnesota while a few showers and thunderstorms have been developing while moving ESE through a small part of Eastcentral Minnesota, generally south of Lake Mille Lacs…This activity is basically occurring on the edge of the greater instability which is slowly moving east out of the Northern Plains and Western Minnesota.
Visible satellite imagery as of 12 PM reveals quite a bit of clearing taking place across Western Minnesota and this clearing seems to be heading ESE per satellite data.
-Early Afternoon visible satellite image showing widespread clouds/limited heating in Northern Minnesota while clearing skies in Westcentral Minnesota which is allowing for more heating and increasing amounts of instability.
Based on current trends it does appear that the Southern portion of the Northland will have the greatest chance for strong to severe thunderstorms beginning later This Afternoon and lasting into early/mid Evening. Best guess for a time frame would be from 3pm until 9pm.
The area most at risk from severe thunderstorms is roughly along and south of a line from Leader and Pine River to Crosslake, Brainerd, and Pine Center, east to Mille Lacs Lake and McGrath to Hinckley and Pine City, east through Siren, Spooner and the Hayward Lakes. Large hail and damaging winds are the main severe weather threats through This Evening, but isolated tornadoes are possible if we can get enough heating/instability to spread this far north. Note: There’s more than enough wind shear in place to support severe thunderstorm/supercell development, and winds are backed quite nicely in Central Minnesota during the next 6-8 hours which may lead to an isolated tornado threat.
*Tornado ingredients forecast per 09z SREF model. Map is valid for Tuesday 4-7 PM time frame.