Severe Thunderstorm Warning 74, NWS Lincoln, IL

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LINCOLN IL
255 PM CDT FRI MAY 25 2001

MAIN FOCUS AGAIN WILL BE PRECIPITATION...STRONG THUNDERSTORM
POTENTIAL INTO EARLY EVENING...AND TEMPERATURES.

LATEST 18Z SURFACE ANALYSIS DEMONSTRATES SURFACE LOW PRESSURE JUST
SOUTH OF MOLINE.  SEVERAL SURFACE TROUGHS WERE ACROSS NORTH
CENTRAL ILLINOIS AND WEST CENTRAL ILLINOIS. LATEST 1845Z IR-SATELLITE
IMAGE DEMONSTRATES LOW PRESSURE SPINNING WESTERN ILLINOIS.
LATEST 1845Z VISIBLE SATELLITE IMAGE DEMONSTRATING CONVECTIVE
CU ACROSS CENTRAL AND SOUTHEAST ILLINOIS. LATEST 18Z MSAS DATA
DEMONSTRATING LI/S TO -4 ACROSS SOUTHEAST CWA. LATEST 1845Z IR-
SATELLITE IMAGE PLENTY OF CLOUDS ACROSS UPPER MIDWEST WITH LOW.
LATEST 1815Z WATER VAPOR IMAGE DEMONSTRATING STRONG S/W ACROSS
EASTERN IOWA...WITH SEVERAL S/WS SPINNING AROUND LOW. OTHER S/WS WERE
ACROSS SOUTHWEST AND WESTERN U.S. LATEST 1822Z KILX RADAR SHOWS
SCATTERED SHOWERS AND THUNDERSTORMS DEVELOPING ACROSS CWA...WITH A
STRONG LINE EXTENDED FROM NEAR BMI-SOUTH TO JUST EAST OF SPI. AT ILX
WIND GUSTS TO 53 MPH AND 51 MPH AT SPI WHEN STORMS MOVED THROUGH.
LATEST 1832Z KDMX RADAR INDICATING SCATTERED SHOWERS AND
THUNDERSTORMS ACROSS EASTERN IOWA MOVING SOUTH SOUTHEAST.

MODELS AGAIN IN FAIRLY DECENT AGREEMENT WITH SOME DIFFERENCES NOTED
WITH PLACEMENT AND STRENGTH OF UPPER LEVEL LOW AND HANDLING OF SW/S.
WILL USE MAINLY ETA/AVN BLEND SOLUTION. STRONG UPPER LEVEL LOW
ACROSS GREAT LAKES WILL CONTINUE NEXT 42 HRS THEN MOVING NORTHEAST
INTO SOUTHERN CANADA. RIDGE ACROSS ROCKIES MOVING EAST INTO
PLAINS STATES NEXT 48 TO 60 HRS. SEVERAL SW/S CONTINUE TO ROTATE
AROUND UPPER LEVEL LOW. ETA KEEPS 80 PERCENT 925MB RH THRU 00Z
TUE. ETA BRINGS IN 20-30 PERCENT 700MB RH ACROSS CWA BY 00Z SUN...
AND THRU 00Z TUE. ETA KEEPS 90KT 300MB JET ROTATES AROUND CUT
OFF UPPER LEVEL LOW THRU 00Z MON...THEN MOVES OUT. ETA T/H CROSS
SECTIONS PLACES HIGH LOW AND MID LEVEL MOISTURE THRU 00Z SUN...
AND KEEPS LOW LEVEL RH THRU 21Z SUN. ETA PLACES +4 TO +6 850MB TEMPS
BY 12Z SUN...+6 TO +8 850MB TEMPS BY 00Z MON...+8 TO +10 850MB
TEMPS BY 12Z MON...+10 TO +12 850MB TEMPS BY 00Z TUE.  ETA 300K
ISENTROPIC SFC INDICATING SOME WEAK ISENTROPIC LIFT AND COND PRES DEF
ACROSS CWA THRU 06Z SUN...THEN BACK BETWEEN 00Z MON TO 00Z TUE.
LATEST MODEL SOUNDINGS DEMONSTRATE WEAK INSTABILITY NEXT 24 HRS.
LI/S -1 TO -4 AND TOTAL TOTALS 50 TO 55 INTO SUNDAY MORNING.
THEN A DECREASE. MODEL SOUNDINGS DEMONSTRATING FAIRLY SATURATED AT
ALL LEVELS UNTIL 06Z SUN...THEN DECREASE IN MID LEVEL MOISTURE
WITH A RETURN OF HIGH RH AT ALL LEVELS BY 00Z MON. WILL
MONITOR KILX RADAR AND MENTION SCATTERED OR PERIODS OF SHOWERS AND
THUNDERSTORMS. WILL LEAVE OUT POPS AGAIN IN FIRST PERIOD.

FWC/FAN/MAV FAIRLY SIMILAR AND WILL NOT STRAY TO FAR.

EXTENDED MODELS HINTING AT ANOTHER LOW AT THE END OF THE WEEK. WILL
BRING IN CHANCE OF PRECIPITATION WED-FRIDAY.

...PRELIMINARY CCF FOR COORDINATION PURPOSES ONLY...

SPI BB 048/072 050/074 053 13443
PIA BB 048/070 049/073 052 13443
DEC BB 048/071 050/073 053 13543
CMI BB 047/071 049/073 052 13743
MTO BB 049/073 050/075 053 13743
LWV BB 052/073 052/076 054 13743

.ILX...NONE.

EH

ILZ027>031-036>038-040>057-061>063-066>068-071>073-271100-

HAZARDOUS WEATHER OUTLOOK FOR CENTRAL ILLINOIS
NATIONAL WEATHER SERVICE LINCOLN IL
1025 AM CDT SAT MAY 26 2001

THERE IS A SLIGHT RISK OF SEVERE WEATHER ACROSS CENTRAL AND
SOUTHEAST ILLINOIS THIS AFTERNOON AND THIS EVENING.

AN AREA OF SURFACE LOW PRESSURE IS EXPECTED TO TRACK EASTWARD
THROUGH NORTHERN ILLINOIS THIS AFTERNOON. THIS LOW WILL HELP IN THE
DEVELOPMENT OF  THUNDERSTORMS ACROSS OUR REGION THIS AFTERNOON...
CONTINUING INTO THE EVENING. SOME OF THESE STORMS MAY BECOME
SEVERE...WITH LARGE HAIL AND DAMAGING WINDS THE GREATEST THREAT.
THEREFORE...SPOTTER ACTIVATION MAY BE NEEDED ACROSS CENTRAL AND
SOUTHEAST ILLINOIS THIS AFTERNOON AND THIS EVENING.

PLAHMER