Severe Thunderstorm Warning 126, NWS Lincoln, IL

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LINCOLN IL
230 PM CDT SAT MAY 27 2000

SEVERAL PROBLEMS NEXT 48 HRS WITH MAINLY TEMPS...LOW CLOUDS...AND
PRECIPITATION. CONCERNED ABOUT SOME SVR WEATHER ACROSS SOUTHERN AND
EASTERN CWA NEXT 8 HRS.

LATEST 18Z SFC ANALYSIS DEMONSTRATING SFC LOW ACROSS CENTRAL
IOWA. SFC WARM FRONT WAS ACROSS NORTHERN ILLINOIS SOUTHEAST
INTO THE OHIO VALLEY. SFC COLD FRONT EXTENDED FROM NORTH CENTRAL
MISSOURI SOUTHWEST INTO THE RED RIVER VALLEY. SFC ANALYSIS
SHOWS MID-UPPER 60S DEW POINTS IN PLACE ACROSS CWA. LATEST 18Z MSAS
DEMONSTRATING AN INSTABILITY AXIS FROM QUINCY TO CHAMPAIGN WITH LI/S
OF -2 TO -5.  LATEST VISIBLE SATELLITE IMAGE DEMONSTRATED LOW CLOUDS
ACROSS NORTHERN ILLINOIS...WITH PLENTY OF CU AND CS ACROSS CWA.
OUTFLOW BOUNDARY WAS ALSO DETECTED IN AND NEAR THE TENNESSEE VALLEY
REGION. LATEST WV SATELLITE IMAGE INDICATING DECENT S/W ACROSS GREAT
LAKES REGION AND SEVERAL S/W EXTENDING FROM SOUTHERN CANADA SOUTH
INTO WESTERN TEXAS.  ANOTHER S/W WAS ALSO ACROSS PACIFIC NORTHWEST.
LATEST 1913Z RADAR IMAGE DETECTING -SHRA DEVELOPING JUST EAST OF
QUINCY AND OTHER ACTIVITY NEAR CHAMPAIGN. OTHER MORE WIDESPREAD
ACTIVITY OVER SOUTHERN ILLINOIS. DEPENDING ON COVERAGE AT ZONE TIME
WILL PROBABLY NOT PLACE POPS IN ZONES. GO WITH SCATTERED WORDING.

MODELS WERE FAIRLY SIMILAR WITH THE MAIN FEATURES OF TROUGH MOVING
ACROSS NEXT 24 HRS. ETA FORMS A H50 CUT OFF LOW BY 12Z SUN ACROSS
NORTHERN ILLINOIS...THEN RIDGE AXIS MOVES TO CWA NEXT 48 HRS.
SOME DIFFERENCES WERE ALSO NOTED...ESPECIALLY WITH HANDLING WITH
SEVERAL S/W NEXT 48 HRS. PREFER MAINLY AN ETA SOLUTION. MODELS SHIFT
HEAVY PRECIPITATION FURTHER SOUTH THIS RUN. OUTFLOW BOUNDARY IN
TENNESSEE VALLEY TOOK AWAY MOST OF GOOD TSTM ACTIVITY AWAY FROM CWA
THIS AFTERNOON. HOWEVER...BELIEVE WE WILL SEE SOME GOOD TSTM LATE
THIS AFTERNOON INTO THE EVENING AS COLD FRONT SLAMS INTO THE WARM...
UNSTABLE AIR IN PLACE ACROSS CWA. LIMITED FACTOR IS GOOD HEATING...
HOWEVER DID HAVE SOME BREAKS THIS AFTERNOON. ETA PLACES (80-90%)
925MB RH ACROSS CWA BY 12Z SUN AND KEEPS IT ACROSS CWA BY 06Z MON
AND THEN DRIES IT OUT OVER WESTERN AND CENTRAL CWA BY 12Z MON. ETA
H85 TEMPS PLACES +14 TO +16 BY 00Z SUN...+08 TO +10 BY 12Z SUN...
+10 BY 00Z MON...+15 TO +10 BY 12Z MON. ETA 305K ISENTROPIC LIFT
INDICATING SOME ISENTROPIC LIFT THROUGH 12Z SUN ACROSS CWA. THEN
AVN 300K ISENTROPIC SFC INDICATING SOME ISENTROPIC LIFT MONDAY
NIGHT/TUESDAY MORNING ACROSS CWA. WILL BRING IN CHC OF SHS AND TSTM
ACROSS CWA MONDAY NIGHT AND TUESDAY MORNING EAST.

EXTENDED WILL INTRODUCE A CHANCE OF SHOWERS AND TSTM THROUGH THE
EXTENDED.

WILL NOT STRAY TOO FAR FROM GUIDANCE. GOING COOLER NUMBERS
TONIGHT CLOSER TO FAN NUMBERS AND COOLER ON SUNDAY.

PRELIMINARY NUMBERS FOR COORDINATION.

SPI EB 055/070 053/082 059 13742
PIA EB 054/069 052/081 058 13742
DEC EB 056/070 053/082 059 13742
CMI EB 056/067 052/080 058 13743
MTO EB 057/070 053/082 058 13743
LWV EB 058/072 054/083 059 13743

.ILX...
IL...NONE.

EH