085
ACUS3 KMKC 191804
SWOMCD
MKC MCD 191804
ILZ000-MOZ000-192000-

SPC MESOSCALE DISCUSSION 1247 FOR CENTRAL IL / CENTRAL AND NERN
MO...
CONCERNING...SEVERE THUNDERSTORM POTENTIAL...


THUNDERSTORM DEVELOPMENT IS EXPECTED ALONG COLD FRONT FROM CENTRAL
MO NEWD INTO CENTRAL IL AND NWRN IND IN THE NEXT 1 TO 2 HOURS.
ALTHOUGH DEEP-LAYER SHEAR REMAINS MARGINAL...WE WILL MONITOR THIS
REGION FOR SIGNS OF CONVECTIVE ORGANIZATION.

LATEST SURFACE DATA INDICATES WIND SHIFT ASSOCIATED WITH COLD FRONT
NOW EXTENDS FROM CENTRAL MO NEWD ACROSS W CENTRAL IL INTO NWRN IND.

DEWPOINTS ALONG THIS BOUNDARY REMAIN IN THE UPPER 60S TO NEAR
70...AND WITH AFTERNOON HEATING SURFACE-BASED CAPE HAS RISEN INTO
THE 2500 TO 3500 J/KG RANGE.  THUNDERSTORMS ARE FORECAST TO DEVELOP
IN LOW-LEVEL FORCING NEAR FRONT...AND VISIBLE IMAGERY SHOWS SOME
INCREASE IN THE CUMULUS FIELD ACROSS THIS REGION -- PARTICULARLY
ACROSS CENTRAL AND NERN MO.

DEEP-LAYER WIND SHEAR REMAINS RELATIVELY WEAK ACROSS THIS REGION AS
STRONGER MID-LEVEL FLOW IS CONFINED TO THE GREAT LAKES REGION.
SHEAR PROFILES ALSO REVEAL BACKING WINDS IN THE LOWER
TROPOSPHERE...SUGGESTING THAT AMOUNT OF STORM ORGANIZATION WOULD BE
LIMITED.  HOWEVER...AMOUNT OF INSTABILITY AND LOW-LEVEL FORCING
INVOF COLD FRONT SUGGESTS AT LEAST SOME POTENTIAL FOR LOCALLY
SEVERE STORMS WITH A MARGINAL HAIL / WIND THREAT THIS AFTERNOON.

..GOSS.. 06/19/01