[MCD] SWOMCD

[MCD at goshenarc.org]

ACUS11 KWNS 031638
SWOMCD
SPC MCD 031638 
INZ000-KYZ000-ILZ000-031845-

MESOSCALE DISCUSSION 1483
NWS STORM PREDICTION CENTER NORMAN OK
1138 AM CDT SAT JUL 03 2004

AREAS AFFECTED...MUCH OF IL AND IND

CONCERNING...SEVERE THUNDERSTORM POTENTIAL 

VALID 031638Z - 031845Z

CONVECTIVE TRENDS ARE BEING MONITORED FOR INCREASING SEVERE THREAT
AND POSSIBILITY OF WW.

BANDS OF CONVECTION ARE BEGINNING TO DEVELOP EAST OF CLOSED LOW NOW
LIFTING INTO SOUTHEAST IOWA...AND ASSOCIATED TROUGH AXIS TRAILING
SOUTHWARD TO 30+ KT CYCLONIC MID-LEVEL JET NOSING INTO SOUTHERN
ILLINOIS/INDIANA.  THIS IS OCCURRING AS RELATIVELY LOW CONVECTIVE
TEMPERATURES IN THE UPPER 70S ARE BEING REACHED...AND ACTIVITY
SHOULD INTENSIFY NEXT FEW HOURS AS 100 MB MEAN MIXED LAYER CAPE
INCREASES IN EXCESS OF 1500 J/KG.

CONVECTIVE INSTABILITY IS LIMITED BY FAIRLY WEAK MID-LEVEL LAPSE
RATES...WITH WARM PROFILES ALSO TENDING TO MINIMIZE HAIL POTENTIAL. 
HOWEVER...MODELS SUGGEST SOUTHERLY LOW-LEVEL JET STRENGTHENING FROM
20 TO 30 KT ALONG AN AXIS FROM WESTERN KENTUCKY THROUGH NORTHERN
INDIANA THROUGH THE AFTERNOON HOURS.  THIS WILL CONTRIBUTE TO
STRENGTHENING SHEAR PROFILES ABOVE WEAK SOUTHEASTERLY BOUNDARY LAYER
IN WARM SECTOR OF SURFACE CYCLONE PROGGED TO LIFT FROM NORTHEAST
MISSOURI INTO NORTHWEST ILLINOIS BY AROUND 21Z.  GIVEN FAVORABLE
THERMODYNAMIC ENVIRONMENT...WITH VERY MOIST BOUNDARY LAYER /LOWER
70S DEW POINTS/...THIS MAY BE SUFFICIENT TO SUPPORT RISK OF ISOLATED
TORNADOES IN MORE VIGOROUS CONVECTION. 

WHILE SHEAR PROFILES WILL BE MORE FAVORABLE FROM NEAR THE
ILLINOIS/INDIANA BORDER EASTWARD ACROSS INDIANA...VERTICAL VORTICITY
ALREADY PRESENT IN CLOSER PROXIMITY TO MID-LEVEL CIRCULATION CENTER
SUPPORTS RISK FOR ISOLATED BRIEF TORNADOES ACROSS PARTS OF
NORTHERN/CENTRAL ILLINOIS AS WELL.

..KERR.. 07/03/2004

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

ATTN...WFO...ILN...LMK...IWX...IND...PAH...LOT...ILX...DVN...

41339038 42078968 42108771 41448617 39628510 38778565
37808734 38168777 39248846 40139006 

WWWW