Flash Flooding in Illinois, July 5, 2007

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PADUCAH KY
1029 AM CDT THU JUL 5 2007

.UPDATE...
UPDATED PUBLIC FORECAST AND GRIDS FOR LATEST TRENDS. ONLY MINOR
TWEAKS WERE MADE. AVIATION SECTION UPDATED AS WELL...BUT BASICALLY
SUPPORTS PREVIOUS THINKING.

&&

.DISCUSSION...
CONVECTION PERSISTED FROM SE ILLINOIS INTO THE PENNYRILE REGION OF
W KENTUCKY AT MID MORNING. THE LATEST NAM/SREF/GFS SHOW THE
ATMOSPHERE BECOMING VERY UNSTABLE BY THIS AFTERNOON...ESPECIALLY
ACROSS WEST CENTRAL THROUGH SOUTHERN SECTIONS OF THE FA AS A TROF
PUSHES ACROSS THE AREA. LIKE YESTERDAY...WILL BE HARD PRESSED FOR
SEVERE CONVECTION...WITH ONLY MARGINAL EFFECTIVE SHEAR...AND VERY
HIGH FREEZING LEVELS. MAY BE SOME MARGINALLY SEVERE HAIL. ALSO
THE FURTHER WEST YOU GO IN OUR CWFA...THE WEAKER THE STEERING WINDS
ARE...SO THE THREAT FOR LOCALLY VERY HEAVY RAIN WILL HAVE TO BE
MONITORED. TEMPS AND DEW POINTS LOOK PRETTY GOOD...SO FEW
MODIFICATIONS THERE. REALIGNED POPS BASED ON LATEST TRENDS AND
MODEL OUTPUT. ESSENTIALLY KEPT WITH OUR HIGH CHC POPS FOR SCT
THUNDERSTORMS.

&&

.PREV DISCUSSION... /ISSUED 220 AM CDT THU JUL 5 2007/
ONGOING CONVECTION OUT AHEAD OF APPROACHING COLD FRONT...STILL NORTH
OF PAH FA. WITH LOSS OF DIURNAL AID...PRIMARY NEAR TERM THREAT IS
LOCALLY HEAVY RAIN. MODELS SAG THIS BOUNDARY INTO FA THIS AM AND
INSOLATION SHOULD ENHANCE DEVELOPMENT THIS AFTERNOON W/ BOUNDARY
STILL IN VICINITY. NAM MODEL A LITTLE DIFFERENT THAN GFS IN SLOWER
PROGRESS W/ FRONT OR FIRING ALONG SLIGHTLY DISPLACED 850 MB
FRONT...EITHER WAY GOING SCT/30-40 POPS LOOK GOOD. LINGERED POP THRU
EVENING MAINLY SE TIL BOUNDARY PASSES.

BOTH MODELS BUT ESP NAM HINTS AT BOUNDARY KIND OF STALLING FRI-SAT
WITH ANOTHER LITTLE BURST OF ENERGY IN NW FLOW POTENTIALLY FIRING
ISOLD ACTIVITY FRI NIGHT. SOUNDINGS ARE MUCH DRIER IN THE COLUMN BY
THEN SO WELL LAY OFF ANY MENTION...BUT IT IS SOMETHING TO MONITOR IN
FUTURE RUNS.

LTL/NO CHANGES NECESSARY MEDIUM-LONG RANGE PTN FCST. MOS TEMPS LOOK
REAL CLOSE AND OFFER A REALISTIC BLEND WITH THE EXISTING FORECAST
TEMPS AND THE COLLAB PIC.

&&

.AVIATION...
A HIGHER LIKELIHOOD EXISTS FOR CONVECTION AT KCGI AND KPAH TODAY AS
THE AXIS OF FORECAST INSTABILITY HAS SHIFTED FURTHER SOUTH OVER THE
PAST 24 HOURS. OUTSIDE OF THAT...VFR SKY AND VSBY EXPECTED WITH WSW
WINDS UP TO 10KTS. FEW HIGHER GUSTS POSSIBLE FROM LATE MORNING
THROUGH LATE AFTERNOON.

&&

.PAH WATCHES/WARNINGS/ADVISORIES...
KY...NONE.
MO...NONE.
IL...NONE.
IN...NONE.
&&

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE PADUCAH KY
952 AM CDT THU JUL 5 2007

ILZ075>078-080>094-INZ081-082-085>088-KYZ001>022-MOZ076-086-087-
100-107>112-114-061000-
JEFFERSON-WAYNE IL-EDWARDS-WABASH-PERRY IL-FRANKLIN-HAMILTON-
WHITE-JACKSON-WILLIAMSON-SALINE-GALLATIN-UNION IL-JOHNSON-POPE-
HARDIN-ALEXANDER-PULASKI-MASSAC-GIBSON-PIKE-POSEY-VANDERBURGH-
WARRICK-SPENCER-FULTON-HICKMAN-CARLISLE-BALLARD-MCCRACKEN-GRAVES-
LIVINGSTON-MARSHALL-CALLOWAY-CRITTENDEN-LYON-TRIGG-CALDWELL-
UNION KY-WEBSTER-HOPKINS-CHRISTIAN-HENDERSON-DAVIESS-MCLEAN-
MUHLENBERG-TODD-PERRY MO-BOLLINGER-CAPE GIRARDEAU-WAYNE MO-CARTER-
RIPLEY-BUTLER-STODDARD-SCOTT-MISSISSIPPI-NEW MADRID-
952 AM CDT THU JUL 5 2007

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTHERN
ILLINOIS...SOUTHWEST INDIANA...WESTERN KENTUCKY...AND SOUTHEAST
MISSOURI.

.DAY ONE...TODAY AND TONIGHT

THERE IS A CHANCE OF THUNDERSTORMS. ISOLATED SEVERE THUNDERSTORMS
CAPABLE OF PENNY TO NICKEL SIZE HAIL WILL BE POSSIBLE DURING THE
AFTERNOON AND EARLY EVENING HOURS. GUSTY WINDS 30 TO 50 MPH WILL
BE POSSIBLE AS WELL. THERE IS A CHANCE OF LOCALLY VERY HEAVY RAIN
WHICH COULD CAUSE LOCALIZED FLOODING.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY

THE NEXT CHANCE OF THUNDERSTORMS IS TUESDAY AND WEDNESDAY.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE REQUESTED TODAY AND THIS EVENING.

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE PADUCAH KY
1237 PM CDT THU JUL 5 2007

ILZ084>094-KYZ007-010-013>016-020-021-MOZ076-086-087-051945-
JACKSON-WILLIAMSON-SALINE-GALLATIN-UNION IL-JOHNSON-POPE-HARDIN-
ALEXANDER-PULASKI-MASSAC-LIVINGSTON-CRITTENDEN-CALDWELL-UNION KY-
WEBSTER-HOPKINS-MCLEAN-MUHLENBERG-PERRY MO-BOLLINGER-
CAPE GIRARDEAU-
INCLUDING THE CITIES OF...CARBONDALE...MURPHYSBORO...HERRIN...
HARRISBURG...SHAWNEETOWN...JONESBORO...VIENNA...GOLCONDA...
ELIZABETHTOWN...CAIRO...MOUND CITY...METROPOLIS...SMITHLAND...
MARION...PRINCETON...MORGANFIELD...DIXON...MADISONVILLE...
CALHOUN...GREENVILLE...PERRYVILLE...MARBLE HILL...
CAPE GIRARDEAU...JACKSON
1237 PM CDT THU JUL 5 2007

...STRONG THUNDERSTORMS PRODUCING HEAVY RAINFALL..

AT 1235 PM...DOPPLER RADAR INDICATED AN EAST TO WEST ORIENTED BAND
OF STRONG THUNDERSTORMS FROM NEAR PERRYVILLE AND JACKSON MISSOURI
TO VIENNA ILLINOIS TO MARION AND MADISONVILLE KENTUCKY. THESE STORMS
WERE PRODUCING VERY HEAVY RAIN AND FREQUENT LIGHTNING.

THROUGH THE EARLY AFTERNOON HOURS...THESE STORMS WILL PERSIST
ACROSS SOUTHEAST MISSOURI...THE SOUTHERN TIP OF ILLINOIS AND INTO
WEST KENTUCKY. THE AXIS OF HEAVIEST RAIN SHOULD BE FROM JUST NORTH
OF CAPE GIRARDEAU TO NEAR VIENNA ILLINOIS TO MARION KENTUCKY. THE
HEAVY RAIN MAY CAUSE STANDING WATER ON AREA ROADS AND IN POOR
DRAINAGE AREAS. DITCHES...SMALL CREEKS AND STREAMS MAY BECOME
FULL OF WATER AND OVERFLOW.

STAY TUNED TO WEATHER RADIO OR LOCAL MEDIA FOR LATER STATEMENTS
AND POSSIBLE ADVISORIES OR WARNINGS.