Monday, May 11, 2009

Missouri / Illinois Chase--May 13, 2009

EDIT: Wednesday afternoon 12:30 p.m....Steve, Scott, Doug, Randy Cooper and I are south of I-70 just off 63 looking at data in Columbia, MO.....Chris is in the KC metro area headed are way.....currently 79F over 64F Dp with overcast skies with peaks of sun now and then.....SKEW-T at KCOU looks good....not impressed with hodo but parameters are decent.....CAPE of 2800, EHI of 4, STP of 6.1 SRH of 252...850 to 500 mb lapse rates of 6.....CINH is negligible....700mb temps are -5......cold front is currently in SE NE, NE KS and SW IA.....999 mb low forecasted to be near IRK at 22Z/13.....we will see what happens...sun out now more than before with temps increasing into the low 80's...we do not want the T/Td spread to be to far...so we will be watching things closely.....more later this afternoon if time allows......we will be streaming as long as cell coverage is good at www.stormchaselive.com......

EDIT: Wednesday morning 1:10 a.m. Ok, I am just like Chris Rice, still wide awake and thinking about the chase target for tomorrow....really torn between the better instability/high cap and the chance of having the overnight MCS ruin the awesome potential for tomorrow in IL...oh, what to do.....the plan right now is for Doug Caster, Steve Polley, Scott Tomlinson and I to leave Cameron around 7 a.m. and head for Columbia, MO....we will check model data, SKEW-T, soundings and satellite imagery there....we can easily get south on 63 to I-44 and make a SW MO, NE OK Chase and make it to our target NE of St. Louis, MO....this is going to be an on the road forecast tomorrow....a significant event is certain...we are just not certain where it or we will be when it occurs.......


Target Area: Nevada, MO to Jefferson City, MO--Storm initiation 21Z to 22Z (on-going MCS over the IL target area concerns me, so I am going to play the SW target area where better parameters appear to be lining up) I anticipate the moderate risk area being moved by SPC at their next forecast. May be going out on a limb here, but these are my thoughts! Signifcant severe weather outbreak is very possible from West Central IL through SE KS...overnight MCS location will aid in my final target determination.....

Forecast Discussion: 996 mb surface low is in the TX panhandle at 0Z/14...well defined cold front from NE MO through SE KS.....stripe of 70F Dp's from SE KS through central MO into west central IL.....with surface temps in the 70 to 80F range....bulk shear is in the 50 to 60 kt range...with surface winds SWLY at 10 kts and every so slightly backed....LL jet forecasted to increase to 40 to 50 kts at 0Z/14....however, the winds veer nearly 90 degrees with height, should produce nice rotating supercells....CAPE 3000 to 3500 J/kg from SE KS, through SW MO to just north of Columbia, MO....LI is over -9 in several places through the aforementioned area....0 to 1 km EHI is 3 to 4 over target area....STP is over 3.....so there is a quick perusal of the Monday night data...will look at things tomorrow and very closely 24 hours from the event......