8/15/08 FCST: MO/IL/AR/IA

[Michael O'Keeffe]

I started taking a look at the models again recently and noticed a bizarre closed low/unseasonably strong trough setting up in parts of E MO/IL/N AR/S IA on Friday, August 15. The 850s are backed from the MO/IA border all the way into NE AR with 40+ kts. common all up and down the region. The 500s are coming in around 50-80 kts. The problem seems to be the GFS showing temps only reaching the low 70s and dews reaching the low-mid 60s causing CAPE to barely exceed 1000 j/kg. I found this somewhat bizarre for mid-August, it looks more like an early spring type of event. This may need to be watched.

[Mike Hollingshead]

I noticed that today too. Looks like a probable chase day to me if it happens. That could be the hard part, getting it to happen, since the last run of the GFS was nothing like it.

http://weather.cod.edu/forecast/GFS/previous/gfsUS_850_spd_144.gif
Last night's 0z run.

http://weather.cod.edu/forecast/GFS/gfsUS_850_spd_132.gif
Today's 12z run same time on Friday.

I hope it pans out since the last real system to chase seems like it has been forever now.

[Brandon Sullivan]

Have been watching this also, the euro however came in much further west on todays run however.. It will be interesting. Quite obviously a lot of dynamics but lacking the thermo profiles as of now.. Wow..

[Brian Emfinger]

I haven't been watching the models for a couple days but after the TSA AFD mentioned this:

"THE NEXT CHANCE OF SHOWERS AND THUNDERSTORMS WILL OCCUR
THURSDAY NIGHT AND INTO THE WEEKEND AS A MID-LEVEL LOW
CURRENTLY OVER WESTERN CANADA DROPS INTO THE CENTRAL UNITED
STATES. THE GFS IS LIKELY GETTING A LITTLE TOO CARRIED
AWAY THIS FEATURE AS IT CREATES A MOST IMPRESSIVE MID-LEVEL
LOW OVER MISSOURI BY SATURDAY. WOULD TEND TO BELIEVE THE
MORE CONSERVATIVE SOLUTION PROVIDED BY THE ECMWF. THE ECMWF IS
MUCH WEAKER AND FURTHER WEST OF THE GFS SOLUTION."

So I take a look at the models and then check here thinking there probably isn't any discussions yet. So, I am glad that at the very least others will share in my disappointment if this craziness doesn't happen. Just looking quickly through some of the models though it seems they are generally showing the same feature with the already mentioned timing and placement differences being the main issues.

[Darrin Rasberry]

The GFS just destroyed the setup in this morning's run, finally seeing sense and going with the WRF. No more surface low over Iowa can be seen and the 500mb low it predicted bursts quite quickly. It's worth it to check tonight's runs to see *just in case* but this morning's run falls more within reason for August.