MESOSCALE DISCUSSION 1592
NWS STORM PREDICTION CENTER NORMAN OK
0153 PM CDT SAT JUL 10 2004
AREAS AFFECTED...CENTRAL IL EWD INTO SRN OH AND FAR NRN KY
CONCERNING...HEAVY RAINFALL AND SEVERE THUNDERSTORM POTENTIAL
VALID 101853Z - 102200Z
ISOLATED DAMAGING WINDS WILL BE POSSIBLE WITH THE STRONGEST STORMS
AS THEY MOVE EWD AROUND 20 KTS ACROSS FAR NRN KY/SRN OH AND PORTIONS
OF CENTRAL/ERN IND. A WW IS NOT ANTICIPATED DUE TO THE MARGINAL
NATURE OF THE THREAT. FARTHER WEST ALONG A STATIONARY BOUNDARY
EXTENDING FROM NEAR PIA ESEWD TO NEAR HUF...CONVECTION WILL LIKELY
TRAIN LEADING TO THE MAIN RISK BEING HEAVY RAINFALL WITH RATES FROM
1-2 IN/HR.
CONVECTION WILL CONTINUE TO INCREASE IN AREAL EXTENT AND STRENGTH
OVER THE NEXT FEW HOURS...ESPECIALLY OVER ERN PORTIONS OF THE OHIO
VALLEY WHERE STRONGER /20-25 KT/ OF LOW TO MID LEVEL UNIDIRECTIONAL
FLOW EXISTS PER REGIONAL VWP DATA. MODERATE INSTABILITY WAS IN PLACE
OVER THIS AREA WITH MLCAPES FROM 1500-2500 J/KG. HOWEVER...GIVEN THE
RELATIVELY WEAK WIND FIELDS...ONLY ISOLATED DAMAGING WINDS ARE
ANTICIPATED. FARTHER WEST...WEAKER MID LEVEL FLOW /ON THE ORDER OF
10-15 KTS/ ALONG WITH BACKED LOW LEVEL FLOW WILL AID IN VERY SLOW
STORM MOTIONS WITH CONVECTION OVER CENTRAL IL INTO WCENTRAL IND.
HEAVY RAINFALL WILL BE POSSIBLE ALONG THE ENTIRE EXTENT OF THE
STATIONARY BOUNDARY WHERE CONVERGENCE AND CELL TRAINING WILL BE
MAXIMIZED. HOWEVER...THE GREATEST THREAT FOR VERY HEAVY RAINFALL
RATES WILL EXIST OVER CENTRAL IL INTO WCENTRAL IND. THIS IS WHERE A
COMBINATION OF FOCUSED CONVERGENCE ALONG THE BOUNDARY...A VERY MOIST
AIRMASS WITH MID 70S DEWPTS /PW VALUES AROUND 1.8 IN./ AND NEARLY
STATIONARY STORM MOTIONS SHOULD ALLOW FOR AREAS OF OVER 2 IN/HR
RAINFALL RATES THROUGH THE AFTERNOON.
..CROSBIE.. 07/10/2004
ATTN...WFO...RLX...JKL...ILN...LMK...IND...ILX...LSX...
39218901 39689056 40249039 40338881 40168590 39668269
39328156 38598189 38378501
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