Severe Thunderstorm Warning 133, NWS Lincoln, IL

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LINCOLN IL
245 PM CDT MON JUN 12 2000

18Z SFC ANALYSIS SHOWS FNT FM DSM TO SBN. WAVE ALONG THE FNT JUST N
OF PIA. VIS SAT LOOP SHOWS CELLULAR CLOUDS ALONG AND S OF FNT...
WHERE MSAS SHOWS INSTABILITY INCREASING. SPC HAS MOST OF CRL IL
OUTLINED IN SLIGHT RISK OF SVR STORMS...THIS LOOKS REASONABLE WITH
GIVEN CONDITIONS AND WITH S/WV PROVIDING SOME UPR SUPPORT FOR
CONVECTION LATE THIS AFT/EVE.

FCST CHALLENGE CONT TO BE PCPN CHANCES.

ALL MODELS INITIALIZED WELL...WITH GOOD HANDLE ON S/WVS MOVING THRU
THE MIDWEST. MODELS ALL SIMILAR WITH TRENDS THRU 48 HRS.

WITH WAVE CONT TO MOVE ALONG SFC FNT...WLD EXPECT A BIT OF A SWRD
PUSH THIS EVE ON ITS BACKSIDE. STILL...NOT EXPECTING FNT TO MAKE IT
MUCH FARTHER SOUTH THAN ILX-CMI LINE. THE TROPICAL CONNECTION CONT
TO CREATE AIRMASS CONVECTION ACRS MUCH OF ILX CWA THIS AFT...
AND UNTIL THE AIRMASS IS CHANGED...EXPECT POPS IN FCST...MAINLY
DIURNALLY DRIVEN. WITH VICINITY OF SFC FNT THIS EVE/TONIGHT...WILL
CONT WITH CAT WORDING.

W/V LOOP CURRENTLY SHOWING IMPRESSIVE JET PUNCHING INTO PACIFIC NW.
THIS JET WILL AID IN DEEPENING THE LONGWAVE TROF OVR ROCKIES/WRN
PLAINS DURING THE NEXT 36 HRS...WITH THE ASSOCIATED SFC LOW GETTING
ORGANIZED AND DEEPENING OVR THE DAKOTAS. THE AFFECT OF THIS TROF ON
THE MIDWEST WILL BE TO REBUILD THE ERN RIDGE...ALLOWING THE FNT TO
LIFT BACK NORTH...INTO SRN WI BY LATE TMRW PER AVN. THIS SHLD
PUSH BEST RISK OF RAIN FARTHER NORTH.

NEXT SHOT OF WIDESPREAD RAIN WILL BE WITH CF LATE ON WED. TIMING ON
THIS A BIT IFFY ATTM...WITH THE DEEPENING TROF...AM INCLINED TO GO
WITH A BIT SLOWER APPROACH. AVN HAS CF PASSAGE FM AFT 06Z TO AFT 12Z
THU ACRS IL. WILL LIKELY CONT PCPN CHANCES INTO EARLY THU. BRIEF
BREAK FM PCPN LATER THU AND ERLY FRI BEFORE NEXT LONGWAVE TROF
CARVES OUT ON THE HEELS OF FIRST. TIMING UNCERTAIN AT THIS
POINT...WITH MRF AND ECMWF ALREADY RUNNING TOO FAST. WILL PUT PCPN IN
BOTH FRI AND SAT UNTIL THIS CAN BE PINNED DOWN BETTER.

TEMPS CONT TO BE TRICKY. MORE SUN MEANS SIGNIFICANTLY HIGHER TEMPS
THAN AREAS WITH CLOUDS/RAIN. WITH FNT LIFTING BACK NORTH...AN
EXPECTING SOME SUNSHINE TO RISE READINGS BACK TO PERSISTANCE...85 TO
90.

PRELIMINARY CCF FOLLOWS...

SPI EE 070/087 071/085 067 81844
PIA EE 068/086 070/084 065 81844
DEC EE 069/087 069/085 066 81844
CMI EE 068/086 069/086 068 81844
MTO BE 070/088 071/088 069 81844
LWV BE 071/091 071/089 069 81+44

.ILX...NONE.

PLAHMER