Severe Thunderstorm WATCH for many of us until 9:00 PM.
This will be a line of storms that will sag north to south this afternoon/evening. Many areas will be in the clear by 6pm so the watch likely will get cleared early.
Beyond tonight's event, we have (2) more severe weather possibilities we need to watch out for.
Friday and Monday.
There will be an area of low pressure that will track north of us from IL into OH. There will be a pockets of decent winds aloft near that low that will help support severe thunderstorms in the afternoon/early evening.
SPC does have Louisville/northward included in a SLIGHT RISK for severe storms for this event.
Capes (instability) certainly looks to be there.
NAM- around 1500 GFS around 1000 with 1500 north/west
Winds aloft are pretty strong with the strongest closer to the low itself.
EHI index isn't off the chart, but high enough that a few isolated tornadoes cannot be ruled out in the region...especially north of Louisville into OH.
We will watch the model trends as we get closer.
This one is going to be tough to nail down---so keep in mind there will likely be changes on this. Especially with timing.
GFS/EURO both pretty robust with a strong low pressure (987mb) moving into the Great Lakes Sun-Tue. The low looks to become negatively tilted...or leans in a NW to SE fashion. This usually means a higher threat for severe thunderstorms in our area.
GFS shows the front moving in Monday PM with thunderstorms.
CAPES do surge quite a bit into the Ohio Valley.
The problems remains with timing. CMC/GEM models delay this low pressure until THURSDAY!
Right now, I think the GFS/EURO movement of Monday makes more sense...but we may have to push timing into Tuesday if the low becomes cutoff quicker than expected.
SPC does not have an outlook out for this event...but did issue the following statement:
WHILE THE PASSAGE OF THIS SYSTEM ACROSS THE CENTRAL -- AND
EVENTUALLY THE ERN/NERN U.S. -- WOULD LIKELY BE ACCOMPANIED BY
FAIRLY SUBSTANTIAL SEVERE POTENTIAL...THE DIFFERENCES IN TIMING AND
EVOLUTION OF THIS SYSTEM AS DEPICTED IN THESE TWO MODELS CAST
CONSIDERABLE DOUBT AS TO EVEN ROUGH APPROXIMATIONS OF TIMING AND
LOCATION. THE ECMWF APPEARS SUBSTANTIALLY MORE ROBUST WITH RESPECT
TO SEVERE POTENTIAL -- PARTICULARLY BEYOND DAY 4...WITH ITS MUCH
SLOWER/NEGATIVELY-TILTED PROGRESSION OF THE TROUGH INTO THE PLAINS
Beyond this storm, there is a risk anyway for colder weather to move in around Wed or Thur next week.
850 temps do crashed behind the low...which normally would mean snow would fall. However, surface temps would be around 40. Granted, it CAN snow at 40...it would obviously melt.
GFS has 850mb temps at about -3C next Wed/Thu. For this time of year, I would like to see values more around -6 to -8 to actually put snow in the forecast. Right now, it just looks too marginal. GFS/EURO have bounced back and forth on this idea of a cold snap for over a week now. We will tackle this more next week.
April looks to be an interesting month with cold air really building in southern Canada. This creates a tight temperature gradient across the eastern US. This will mean strong areas of low pressure.