/Issued 12:51 PM CDT, Tuesday, June 9, 2015/
12z HopWRF model valid at 7 PM this evening. Note: This model has 4 members. Here’s member number 1.
Member number 3 valid at 7 PM this evening. Note: Member 2 doesn’t show much except in South Central Minnesota, and member 4 wasn’t updated at the time of this post.
HRRR model valid at 7 PM this evening.
4 KM NAM – 12z run valid at 7 PM this evening.
Slight risk for severe thunderstorms continues through this evening in all of Northeast Minnesota and Northwest Wisconsin (Yellow area on the map) Source, Storm Prediction Center
Damaging wind outlook through this evening
Large hail outlook through this evening
Tornado outlook through this evening
…Isolated to scattered strong to severe thunderstorms possible later this afternoon and this evening in parts of the Northland…
Early this afternoon:
Sky conditions ranged from mostly cloudy to partly sunny and there’s been some showers which have been moving southeast through parts of North Central Minnesota. These showers are most likely developing in a warm/moist advection pattern out ahead of a warm front which was over the Southwest half of Minnesota early this afternoon.
A wide range in temperatures in Minnesota as of 12 PM with 60s and 70s in Northeast Minnesota and Northwest Wisconsin with 80s and even a few 90 degree temperatures already showing up in much of Western, Central, Southern, and Eastern Minnesota.
Through This Evening:
A warm front and cold front will be moving through the Northland. The warm front approaches from the west/southwest while the cold front approaches from the west. Low pressure will also be moving east out of the Northern Plains.
Scattered showers will continue to move southeast through parts of Northeast Minnesota and Northwest Wisconsin for the rest of the afternoon.
Some clearing should occur as these showers move away and as long as that happens then we should see instability increase with CAPE of 1000 j/kg, possibly upwards of 2000 j/kg in parts of the area by later in the afternoon and into the early evening hours. Lifted Indices are forecast to drop into the -2 to -6C range with steep mid level lapse rates in place too.
Winds aloft look to be on the strong side with NW winds at 500mb at around 40-50 knots with upper level winds in the 80-100 knot range. The low level jet coming out of the SW will be in the 20-35 knot range. Computer models show the Effective Bulk Shear and 0-6 km Shear to be in the 30-50 knot range over most of the Northland. All of these parameters are favorable for organized thunderstorms.
The limiting factors will be the current showers and clouds which could delay surface heating, were also dealing with a thick layer of haze/smoke which could also keep us from warming up too much. All of these factors could lead to much less instability than what the computer models are showing for later today, thus a much lower chance for thunderstorms and severe weather.
Scattered thunderstorm development is possible after 4-5 PM Today, perhaps a little earlier in the Western/Northwest sections of the Northland. If we do get sufficient heating and enough instability to build-up, then there will be a risk for a few strong and severe thunderstorms late this afternoon into the evening with large hail and damaging winds being the main threats, but an isolated tornado could also occur especially with any storm that can develop and latch onto either the surface warm front or a lake breeze boundary which will likely linger near Lake Superior through early this evening.
Tim