:: "Fairly" Stormy
Well, here it is...the start of the MN State Fair tomorrow and with it a Murphy's Law-typical forcast for thunderstorms. We certainly have seen a climate change over the last 24 hours...it is downright tropical in some areas, with dewpoints in the upper 60's and lower 70's. About 4am this morning the TC Metro was boomed from their beds to a strong line of thunderstorms that carried with it some soaking rain, frequent lighning, and wind. Those storms pushed out a nice boundary that "settled" along the stationary front that sits prominently about 20 miles south of here. NOAA's MESONET shows it nicely:
As does the MPX WSR-88D:
On the first image, I penciled in the boundary...which would be the red curved line with the humps. Notice the stations to the south of the line colored purplish-red (temps 80F+) and with winds from the south. North of the line the stations are hot pink (temps 70-79F) and winds from the northeast . I also pointed out the location of our station.
On the second image, the boundary is seen as a thin line of radar return extending from Hutchinson (HCD) through Lakeville (LVN) and southeast towards Stanton (SYN). I enclosed the area to look in a white elipse.
So what is the big deal?? Well, a couple of things. First, this demonstrates the fluid dynamics of the atmosphere in a very graphical way. Second, it means two very different airmasses are colliding with each other at the boundary. For the radar to pick it up like this is impressive.
Dewpoints will remain high as a short wave pushes down over the front range causing pressure to fall precipitously ahead of the system that could spawn more heavy storms tomorrow. The models have the low picked out commonly over the Great Plains trekking from central NE in the AM to over the Couteau des Praries by 3pm and then in central MN by 6pm. Instability will be hampered only by the possibility of atmospheric capping over southern MN. The morning cloud fields will tell the tale of possibility in this realm. Overall however, all evidence points to a significant rain event at the least, and possibly a severe wind and hail event at the most, with some tornadic potential more for SE MN. Here is a prelim forecast...hope to update throughout the day tomorrow as the situation warrants....
THURSDAY...Partly Cloudy and humid. 50% chance of thunderstorms after 4pm, some with heavy rain, hail, and damaging wind. East winds 5-10, turning southeast. High 84. Low 63. Rain ending after 10pm
FRIDAY...Mostly Sunny, cooler, drier. High 76, low 56. Northwest wind 5-10.
SATURDAY...Partly Cloudy. High 78. Low 58.