[MCD] SWOMCD

[MCD at goshenarc.org]

ACUS11 KWNS 181527
SWOMCD
SPC MCD 181526 
ILZ000-MOZ000-181800-

MESOSCALE DISCUSSION 0736
NWS STORM PREDICTION CENTER NORMAN OK
1026 AM CDT TUE MAY 18 2004

AREAS AFFECTED...E CNTRL/NE MO INTO CNTRL IL

CONCERNING...SEVERE THUNDERSTORM POTENTIAL 

VALID 181526Z - 181800Z

CONVECTIVE TRENDS ARE BEING MONITORED. THREAT FOR LARGE HAIL IS
EXPECTED TO INCREASE BY AROUND 18-19Z...WITH POTENTIAL FOR STRONG
GUSTY WINDS INCREASING THEREAFTER.  WW MAY BECOME NECESSARY BY EARLY
AFTERNOON.

AS STRONGER LOW-LEVEL CONVERGENCE/WARM ADVECTION BECOMES FOCUSED
BENEATH INCREASINGLY CAPPED ENVIRONMENT ACROSS NORTH CENTRAL
OKLAHOMA/SOUTH CENTRAL KANSAS...ONGOING CONVECTIVE CLUSTER HAS
WEAKENED AS IT DEVELOPS EASTWARD INTO THE LOWER MISSOURI VALLEY. 
ACTIVITY IS DEVELOPING EASTWARD WITH FORCING ASSOCIATED WITH WEAK
MID-LEVEL SHORT WAVE TROUGH/JET STREAK...WHICH MODELS SUGGEST WILL
SHIFT ACROSS MISSOURI INTO ILLINOIS BY LATE AFTERNOON.

CONVECTION HAS GENERATED FAIRLY SUBSTANTIAL COLD POOL AHEAD OF
SURFACE COLD FRONT...AND COLD POOL APPEARS TO BE ADVANCING EASTWARD
AT AROUND 30 KT.  BY/SHORTLY AFTER 18Z...BOUNDARY APPEARS LIKELY TO
EXTEND EAST OF THE HANNIBAL/QUINCY AREA INTO AREAS NORTH/WEST OF ST.
LOUIS...WHERE SURFACE TEMPERATURES WILL BE WARMING INTO 80S.  AS
CAPPING SLOWLY WEAKENS ACROSS THIS AREA...FORCING ALONG LEADING EDGE
OF CONVECTIVE OUTFLOW LIKELY WILL SUPPORT RE-INTENSIFICATION OF
VIGOROUS THUNDERSTORM ACTIVITY IN ENVIRONMENT WITH MEAN MIXED LAYER
CAPE AROUND 1500 J/KG.

THOUGH SHEAR PROFILES NEAR MID-LEVEL JET STREAK WILL BE MODERATE AT
BEST...SUFFICIENT EVAPORATIVE COOLING SHOULD OCCUR NEAR HEAVIER
PRECIPITATION CORES TO MAINTAIN FAIRLY STRONG COLD POOL/MESO HIGH. 
AS SURFACE PRESSURE PERTURBATION STRENGTHENS INTO THE AFTERNOON
HOURS...RISK OF GUSTY...POTENTIALLY DAMAGING...WINDS LIKELY WILL
INCREASE ACROSS A LARGE PART OF CENTRAL ILLINOIS.

..KERR.. 05/18/2004

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...LOT...ILX...LSX...DVN...

39439218 39789134 40489052 41349003 41628886 41348796
40638758 39128844 38508971 38559128 38589254 

WWWW