Severe Thunderstorm Warning 165, NWS Springfield, MO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPRINGFIELD MO
232 PM CDT THU AUG 10 2000

SURFACE ANALYSIS SHOWS A DIFFUSE FRONTAL BOUNDARY FROM CENTRAL NEB
ACROSS THE LAKE OF THE OZARKS TO SERN MO. VISIBLE IMAGERY
PERHAPS DEPICTS THE BOUNDARY MORE CLEARLY WITH A DISTINCT LINE OF
TOWERING CUMULUS AND DEVELOPING CELLS ACROSS THE NERN PORTION OF
THE FORECAST AREA. LITTLE CHANGE IN THE AIRMASS TODAY WITH DEWPOINTS
IN THE LOWER 70S. LAPS DATA INDICATES CAPES AROUND 3000 J/KG AND
LIFTED INDICES AROUND -7 BUT ONLY MODEST SURFACE CONVERGENCE TO WORK
WITH.

AN EXPANSIVE RIDGE WILL DOMINATE THE WEATHER ACROSS THE WESTERN AND
CENTRAL U.S. WHILE A TROUGH DIGS DOWN THE EAST COAST. MODELS SIMILAR
IN KEEPING THE FORECAST AREA ON THE EASTERN PERIPHERY OF THE RIDGE
THROUGH THE WEEKEND BEFORE THE RIDGE FLATTENS OVER THE AREA EARLY
NEXT WEEK.

IN THE SHORT TERM...GOOD INSTABILITY WILL SUPPORT ISOLATED
THUNDERSTORMS THIS EVENING BUT WEAK SURFACE CONVERGENCE AND
LIMITED UPPER DYNAMICS WILL INHIBIT ACTIVITY. THE TAIL END OF A
SHORTWAVE PUSHING THROUGH THE OHIO RIVER VALLEY MAY PROVIDE SOME
LIFT HOWEVER. WEAK WIND FIELDS WILL RESULT IN SLOW IF ANY STORM
MOVEMENT AND LOCALLY HEAVY RAIN WHERE ONE DOES DEVELOP. THE FLOW
AROUND SURFACE HIGH PRESSURE FROM ERN IOWA INTO THE GREAT LAKES MAY
BRING SOME DRIER AIR INTO THE NERN COUNTIES OVERNIGHT TO DROP LOWS
INTO THE 60S.

ON FRIDAY AND SATURDAY...SURFACE HIGH PRESSURE WILL SHIFT SLOWLY
FROM THE GREAT LAKES INTO THE OHIO RIVER VALLEY PROVIDING AN E TO SE
FLOW. THIS MAY CONTINUE AN INFLUX OF SLIGHTLY DRIER AIR INTO THE
AREA...MAINLY IN THE ERN COUNTIES. WITH LITTLE CHANGE IN 500 MB
HEIGHTS AND 850 MB TEMPERATURES...TEMPERATURES WILL REMAIN SIMILAR
BUT SLIGHTLY LOWER DEWPOINTS SHOULD KEEP HEAT INDICES IN CHECK. THE
WARMEST READINGS WILL BE IN THE WRN COUNTIES IN CLOSER PROXIMITY TO
THE THERMAL RIDGE OVER THE PLAINS.

IN THE EXTENDED...THE RIDGE IS PROGGED TO SHIFT OVER THE AREA EARLY
NEXT WEEK AS THE WESTERLIES BECOME ESTABLISHED ACROSS SRN CANADA.
THIS WILL CONTINUE THE VERY WARM AND INCREASINGLY HUMID CONDITIONS
ONCE AGAIN. A FRONTAL BOUNDARY DROPS INTO IOWA SUNDAY BUT DO NOT SEE
IT MAKING IT THIS FAR SOUTH.

FCSTID = 11
SGF   69  91  68  92 /  20  10   0   0
JLN   73  93  71  94 /  20  10   0   0
UNO   69  90  68  92 /  20  10   0   0
VIH   67  89  67  90 /  20  10   0   0

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

FOSTER

KSZ073-097-101-MOZ055>058-066>071-077>083-088>098-101>106-102300-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE SPRINGFIELD MO
100 PM CDT THU AUG 10 2000

...HEAT INDICES OF 100 TO 105 THIS AFTERNOON...
...ISOLATED THUNDERSTORMS POSSIBLE THIS AFTERNOON AND EVENING...

HIGH TEMPERATURES IN THE LOWER TO MIDDLE 90S WILL COMBINE WITH THE
HUMID AIRMASS TO PRODUCE HEAT INDEX VALUES OF 100 TO 105 DEGREES. IF
YOU HAVE OUTDOOR PLANS...BE SURE TO TAKE FREQUENT BREAKS AND DRINK
PLENTY OF WATER IN ORDER TO MINIMIZE THE RISK OF HEAT RELATED
ILLNESSES.

WIDELY SCATTERED THUNDERSTORMS WILL DEVELOP IN THE AFTERNOON HEAT. A
FEW OF THE THESE STORMS COULD BE STRONG...AND PRODUCE WIND GUSTS TO
50 MPH...FREQUENT LIGHTNING AND BRIEF HEAVY RAIN.

STORM SPOTTERS AND EMERGENCY MANAGERS ARE NOT EXPECTED TO BE NEEDED
FOR SEVERE WEATHER ACTIVATION THIS AFTERNOON OR TONIGHT.

.OUTLOOK FOR FRIDAY THROUGH SUNDAY...
AFTERNOON HEAT INDEX VALUES OF 100 TO 105 CAN BE EXPECTED OVER THE
WEEKEND.

FOSTER