Flash Flood in Missouri, August 30, 2001

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPRINGFIELD MO
235 PM CDT THU AUG 30 2001

FORECAST CONCERNS INCLUDE PRECIPITATION CHANCES THROUGH FRIDAY AND
EXTENT OF COOLING AND CLOUDS OVER THE WEEKEND.

CONVECTION FIRING AGAIN THIS AFTERNOON IN VERY MOIST AND MODERATELY
UNSTABLE AIRMASS.  ACTIVITY BEING AIDED BY MID-UPPER LEVEL THROUGH
AS DEPICTED ON PROFILER DATA ALONG THE KANSAS BORDER.  SURFACE
ANALYSIS SHOWS A FRONTAL BOUNDARY DROPPING SOUTHEAST ACROSS
NORTHWEST MISSOURI WITH CONVECTION ORGANIZING ALONG IT.

UPPER TROUGH SWINGING ACROSS CENTRAL CANADA AND THE GREAT LAKES
REGION WILL NUDGE THE FRONT SOUTH OF THE AREA BY FRIDAY EVENING.
CANADIAN HIGH PRESSURE WILL NOSE INTO THE REGION OVER THE
WEEKEND...BUT AN IMPULSE COMING OUT OF THE GREAT BASIN WILL POSE
SOME QUESTIONS CONCERNING CLOUD COVER AND POSSIBLE PRECIPITATION.
MODELS WERE IN REASONABLE AGREEMENT ALTHOUGH THE AVN WAS A LITTLE
QUICKER THE FRONTAL PASSAGE.  WILL GENERALLY FOLLOW THE ETA.

FOR TONIGHT...WILL SEE NUMEROUS THUNDERSTORMS THROUGH THE EVENING AS
MID-UPPER LEVEL TROUGH AXIS CROSSES THE AREA AND THE FRONT
APPROACHES FROM THE NORTH.  EXPECT LINEAR COMPLEX OF STORMS TO PUSH
INTO SOUTHERN MISSOURI THIS EVENING.  GREATEST SEVERE THREAT APPEARS
TO BE OVER THE LAKE OF OZARKS REGION IN BETTER INSTABILITY. WILL GO
WITH LIKELY PROBABILITIES.  WITH 850 MB DEWPOINTS NEAR 15 DEGREES
AND PRECIPITABLE WATER AROUND 1.75...LOCALIZED FLOODING WILL BE A
THREAT.

ON FRIDAY...THE FRONT SHOULD REACH CENTRAL MISSOURI BY DAYBREAK THEN
SAG SOUTHWARD TO THE ARKANSAS BORDER BY MID AFTERNOON.  UPPER TROUGH
AXIS WILL BE SHIFTING TO THE EAST WITH BEST DYNAMIC LIFT GOING WITH
IT.  WILL CONTINUE WITH RAIN CHANCES BUT EXPECT ANY STRONG ACTIVITY
TO BE CONFINED CLOSER TO THE ARKANSAS LINE WHERE DAYTIME HEATING
WILL BE MORE OF A FACTOR. CLOUDINESS AND FRONTAL PASSAGE WILL KEEP
HIGHS A LITTLE COOLER OVER MOST LOCATIONS.

SURFACE HIGH PRESSURE WILL BUILD ACROSS THE AREA FRIDAY NIGHT AND
SATURDAY BRINGING A COOLER AIRMASS TO THE OZARKS.  THE SHORTWAVE NOW
OVER THE GREAT BASIN REGION WILL PUSH INTO THE HIGH PLAINS ON
SATURDAY.  THE AVN THEN STALLS THIS SYSTEM OVER THE CENTRAL PLAINS
WITH WARM AIR ADVECTION PATTERN AND RESULTING PRECIPITATION
REMAINING TO OUR WEST.  THIS DIFFERS FROM THE MORE PROGRESSIVE MRF.
INCREASE IN MID-HIGH LEVEL CLOUDS LOOK TO BE THE MAIN IMPACT AND
WILL NOT INCLUDE RAIN CHANCES AT THIS TIME.

PRELIMINARY NUMBERS FOR FORECAST COORDINATION ONLY...
FCSTID = 11
SGF   65  85  62  83 /  60  40  30  10
JLN   64  83  62  82 /  60  30  10  10
UNO   65  85  61  82 /  60  50  30  10
VIH   63  82  59  80 /  60  30  10  10

.SGF...
MO...NONE.
KS...NONE.

FOSTER