/Issued 6:28 PM CDT Sunday, July 20, 2014/
Weather Summary for NE Minnesota and Northwest Wisconsin
A warm and muggy day across the Northland with highs in the 80s to near 90 degrees with dew points in the 60s to lower 70s. Afternoon heat indices climbed into the 90s in parts of the area. Winds were out of the south at 10 to 20 mph with higher gusts. Relief from the warm temperatures could be found along the North Shore of Lake Superior Today where high temps stayed in the 60s thanks to an onshore wind.
Forecast Discussion for NE Minnesota and NW Wisconsin
Valid through Monday Night July 21, 2014
The atmosphere will remain very unstable during the next 24-30 hours with CAPE values in the 1500 to 4000 j/kg range with pockets of CAPE of around 5000 j/kg possible. Lifted Indices will range from -3 to -11C. Mid level winds will be around 30-40 knots with stronger winds off to our northwest. Deep layer shear should be around 30 knots. All of these ingredients are sufficient for severe thunderstorm development, but warm temperatures aloft have so far kept thunderstorms from developing Today.
A surface trough was over NW Minnesota early This Evening and that boundary may help to trigger a few showers and thunderstorms over the Northland Tonight, if storms are able to develop they could be severe with hail and strong winds, the main threat for severe weather Tonight should remain over Northern Minnesota, Iron Range, and Borderland areas.
The focus Monday and Monday Night will be on an area of low pressure which is forecast to track ENE out of the Dakotas. This low combined with a frontal boundary which will sag slowly south out of Northwest Minnesota will be the focal point for one or more rounds of showers and thunderstorms over the Northland. Severe thunderstorms could develop Monday and or Monday Night with strong winds and hail being the primary hazards.
Keep an eye to the sky and be sure you have a way to be notified if any watches or warnings are issued through Monday Night. Stay weather aware. And remember when thunder roars get indoors.
There will also be a threat for heavy rain due to the tropical levels of humidity that will be in place with dew points of 65 to 75 degrees and PWATS of 1.50″+ Locations that see multiple rounds of storms could easily pick up 1 to 3″ of rain by Tuesday AM.
The other big story will be the brief warm wave. Lows Tonight and Monday Night will be in the 60s and 70s with highs Monday in the 80s and 90s. Heat index values or feels like temperatures are expected to climb into the mid 90s to around 100 degrees over portions of the Northland Monday Afternoon and Evening for this reason a Heat Advisory has been issued for Central and Southern St. Louis…Carlton…Pine…Aitkin…Crow Wing…Cass…and Southern Itasca Counties in Minnesota and for Douglas…Bayfield…Ashland..Burnett…Washburn…and Sawyer Counties in Wisconsin.
Cooler and less humid weather returns by mid week with dry weather as well as an area of high pressure passes through the region.
5 DAY FORECAST FOR DULUTH AND SUPERIOR
Event: *HEAT ADVISORY*
Timing: 11 AM Monday until 9 PM Monday.
.Tonight… Muggy and hazy. Partly to mostly cloudy. A few showers or thunderstorms possible late. Low 63 to 68 but cooler closer to Lake Superior. Wind south at 10 to 20 mph inland and east near Lake Superior.
.Monday… Muggy and hazy. Partly cloudy. High 83 to 88 but it may be cooler closer to Lake Superior. Wind south at 10 to 20 mph. Afternoon heat index values in the 90s.
.Monday Night… Muggy with showers and thunderstorms possible. Low 65 to 70. Wind south to southeast at 10 to 15 mph.
.Tuesday… Showers possible. Considerable cloudiness. High 71 to 76.
.Tuesday Night… Partly cloudy. Low 52 to 57.
.Wednesday… Partly cloudy. High 70 to 75.
.Wednesday Night… Partly cloudy. Low 50 to 55.
.Thursday… Partly cloudy. High 72 to 77.
Normal temperatures for Tomorrow
High: 77
Low: 56
Sunrise Monday: 5:36 AM CDT
Sunset Monday: 8:54 PM CDT
Tim