Most of this entry will focus on the setup this afternoon/evening. Then I will touch base on the pattern ahead. Very "early spring" pattern for us. It seems like we can't keep it in one season at a time anymore.
Anyway...here is the setup right now.
Few cirrus clouds over us now. They will push east and we will break back out in blue skies for a bit. The warm front is to the south of us. The low in MO track into IL/IN and drag that warm front right across us. Until that happens, nothing is going to happen. So now it is a waiting game.
One thing is for sure, we need the moisture to move in.
Current dewpoints in the 60s (in the green) are along and south of the warm front.
The SPC meso page can forecast those dewpoints out 6 hours. And here is where it as them by rush hour:
Helecity values help us in determine any "spin" the storms may develop. Right now, the highest values again are south of the low ...and along the warm front. But even then, only around 100. During tornado outbreak threats---we see those numbers of 300-600. So you can see how this isn't a huge tornado threat.
SPC page once again forecasts out 6 hours..and brings those 100 values right into southern IN and KY. If we get tornado warnings today--it would be at that point.
This is only a narrow window of a severe threat that will be maximized when the low is at its closet point tracking across IL/IN. After it passes---the threat ends pretty fast.
Timing:
Now-4pm 30% (west/south)
4pm-8pm 90% (moving in from the west to east)
8pm-10pm- 40% (moving into eastern areas)
10pm+- 30% (showers)
SPC OUTLOOK:
Slight Risk
Tornado Risk (right where the 100 values were on helecity)
Hail Risk
Damaging Wind Risk
THOUGHTS OVERALL:
There will be a couple waves of storms. Some could be severe..some will be just typical storms. We will watch the 4-8pm time carefully to see if the rotation does develop as forecast by some of the models. Once that threat has passed---we can relax. This is not an outbreak---but only takes one storm to cause harm---so that is why we are mentioning the threat often.
We will watch the radar carefully this afternoon for timing adjustments and warnings/watches that may come out. So stay close. Don't forget to download our weather app "WAVE RADAR" for your cell if away.
SO WHAT IS NEXT?
The low move into the Great Lakes...and we get a backlash flow. So this will be a BACKLASH WEEKEND as I call it. What does that mean? Well the air above us Fri-Sun will be pretty cold for this time of the year on the backside of this low pressure. Any sunshine will allow cumulus clouds to reach up and tap into that cold air. Hail then becomes a threat. Not necessarily large hail...but enough that a few warnings are certainly possible. Again, highly dependent on any sunshine we can pick up. If we stay cloudy, the cumulus clouds won't be able to climb very high.
Having said that...here is how it looks.
Friday backlash: not a high threat. Small instability showing up. Mostly a cloudy day so that should keep it limited to just showers/drizzle.
Saturday backlash: better chance for some sun. So afternoon pop-up storms with a hail threat possible. Perhaps even some funnel clouds in a few cases--touchdowns not likely. (usually coined the term "cold air funnels")
Sunday backlash: storm threat shifts more east as the low and cold pool above us moves east as well.
There is another cold front moving down in the NW flow (thanks to this current low) that will drop down Monday/Tuesday. That will have to be watch for a severe threat (high winds) that may develop.
Once that passes---we cool down to near or slightly below normal for the 2nd half of next week.
Then AFTER THAT---we heat up. 90s likely try to make a comeback and tropics head up in the Gulf of Mexico.
But now I am getting ahead of myself :)
Brian, do you think a severe weather watch will be issued for this afternoon?
Thanks to the WAVE 3 Weather Team for keeping us updated during this crazy Kentucky weather!
***** I think the chance is higher than not right now yes, - BG
Posted by: Carrie Mann | May 31, 2012 at 02:32 PM