Severe Thunderstorm Warning 239, NWS Springfield, MO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPRINGFIELD MO
250 PM CDT THU AUG 9 2001

LATEST SURFACE ANALYSIS INDICATES THAT DAYTIME HEATING/MIXING HAS
CAUSED THE COLD FRONT OVER THE CENTRAL PLAINS TO SLOW MARKEDLY THIS
AFTERNOON. DEWPOINT/TEMPERATURE GRADIENT AND PRESSURE RISES WOULD
SUGGEST THAT THE FRONT STRETCHES FROM NEAR OMAHA TO NORTHWEST KS
AS OF 19Z. A SECOND PRESSURE TROUGH AND CONVERGENCE LINE LIES ACROSS
CENTRAL KS EXTENDING INTO NW MO...AND IS EVIDENT ON 88D RETURNS.
THIS COMPLEXITY LEADS TO SOME UNCERTAINTY AS TO THE TIMING AND
PLACEMENT OF CONVECTION...WHICH IS EXPECTED TO DEVELOP ALONG AND
AHEAD OF THESE BOUNDARIES TONIGHT.

IN THE SHORT TERM...WILL CONTINUE TO MONITOR DIURNAL CONVECTION THAT
HAS DEVELOPED IN TROPICAL MOISTURE POOL ACROSS CENTRAL/SC MO. HEAVY
RAINFALL AND GUSTY WINDS WILL BE POSSIBLE IN ANY STORMS THAT REALLY
GET GOING. THESE SHOULD DIMINISH QUICKLY AFTER SUNSET.

ETA/AVN MODEL SOLUTIONS ARE IN DECENT AGREEMENT WITH STALLING THE
FRONT ACROSS THE SOUTHERN OZARKS BY FRIDAY MORNING. UPPER JET
DYNAMICS AND POTENT SHORTWAVE WILL PUSH ACROSS THE UPPER
MIDWEST...WHERE 850MB MOISTURE AND THERMAL RIDGE AXES SUGGEST WILL
BE THE BEST FOCUS FOR ORGANIZED STORMS. FURTHER SOUTH...CONVECTION
WILL GRADUALLY BUILD ALONG THE SURFACE BOUNDARY...BUT SHOULD BE MORE
SCATTERED AND ELEVATED IN NATURE GIVEN OVERNIGHT TIMING. AM STILL
CONCERNED ABOUT HEAVY RAINFALL POTENTIAL GIVEN LIGHT SFC-500MB FLOW
NEARLY PARALLEL TO BOUNDARY AND PRECIPITABLE WATER PROGS IN EXCESS
OF 2. WITH RECENT HEAVY RAINFALL ACROSS PARTS OF THE CWA....WE MAY
SEE SOME LOCALIZED FLOODING...HOWEVER IT APPEARS TOO LOCALIZED TO
ISSUE A CWA-WIDE FLASH FLOOD WATCH.

ANOTHER CHANCE FOR HEAVY RAINFALL MAY OCCUR ON SATURDAY AS A WARM
AIR ADVECTION PATTERN SETS UP OVER THE STALLED SURFACE BOUNDARY.
MOIST SOUTHEAST FLOW...AIDED BY SOME OROGRAPHIC UPSLOPE COULD LEAD
TO ADDITIONAL HEAVY PRECIP OVER THE OZARKS PLATEAU.

WILL REMOVE PRECIPITATION CHANCES ON MONDAY/TUESDAY AS 500MB
SHORTWAVE TROUGH AXIS SWINGS INTO THE OHIO VALLEY...LEAVING US WITH
ANTI-CYCLONIC FLOW AND BUILDING HEIGHTS. STRONG SURFACE RIDGE SHOULD
PROMOTE A RAPID WARM UP MIDWEEK.

GOING TEMPERATURE FORECAST A WELCOME RELIEF...WITH MAXES GENERALLY
IN THE 80S AND LOWS IN THE 60S. WILL MAKE FEW CHANGES.

THANKS FOR COORDINATION ICT/EAX.

FCSTID = 14
SGF   69  83  65  83  /  60  50  40  40
JLN   72  84  66  84  /  60  50  40  40
UNO   73  82  65  82  /  40  60  40  50
VIH   68  80  62  82  /  60  40  30  40

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

BOOKBINDER

KSZ073-097-101-MOZ055>058-066>071-077>083-088>098-101>106-100000-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE SPRINGFIELD MO
100 PM CDT THU AUG 9 2001

...HOT AND HUMID THIS AFTERNOON WITH HEAT INDICES NEAR 105 DEGREES...
...HEAVY RAINFALL POSSIBLE AFTER MIDNIGHT AND FRIDAY MORNING...

TEMPERATURES IN THE 90S WILL COMBINE WITH A VERY MOIST AIRMASS TO
BRING ONE LAST AFTERNOON OF OPPRESSIVE HEAT TO THE MISSOURI OZARKS
AND SOUTHEAST KANSAS. HEAT INDICES WILL AVERAGE BETWEEN 100 AND 105
DEGREES UNTIL SUNSET. IF YOU PLAN TO BE OUTSIDE...AVOID PROLONGED
EXPOSURE TO THE HEAT AND ALSO AVOID STRENUOUS PHYSICAL ACTIVITY.
DRINK PLENTY OF WATER TO AVOID DEHYDRATION.

A STRONG COLD FRONT WILL PUSH INTO THE OZARKS REGION TONIGHT...
INCREASING THE LIKELIHOOD FOR SHOWERS AND THUNDERSTORMS. THE
COMBINATION OF DEEP MOISTURE AND LIGHT WINDS WILL LEAD TO THE
POTENTIAL FOR PROLONGED HEAVY RAINFALL...AS THE COLD FRONT BEGINS
TO STALL ACROSS THE AREA FRIDAY MORNING. RAINFALL TOTALS OF ONE TO
THREE INCHES ARE POSSIBLE BY FRIDAY MORNING...ALONG WITH LOCALIZED
FLOODING.

WHILE SEVERE THUNDERSTORM DEVELOPMENT IS NOT ANTICIPATED...SPOTTER
ACTIVATION MAY BE REQUIRED IF FLASH FLOOD CONDITIONS DO DEVELOP LATER
TONIGHT.

.EXTENDED OUTLOOK...
THE CHANCE OF SHOWERS AND THUNDERSTORMS WILL CONTINUE THROUGH THE
WEEKEND... HOWEVER NO HAZARDOUS WEATHER IS EXPECTED.

BOOKBINDER