Severe Thunderstorm Warning 103, NWS Springfield, MO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPRINGFIELD MO
339 PM CDT SUN MAY 21 2000

OF ALL THE MODELS...NGM HAS THE BEST HANDLE ON UPPER AND SFC FEATURES
...EXCEPT THE NGM SFC DWPTS ARE TOO COOL.

UPPER LVL VORT WAS EXITING THE CWFA BY MID AFTN. ALL MODELS FCST
THAT THIS SYS WILL PULL 500MB TROF EWD TO THE MID WEST BY MONDAY.
THIS LEAVES NWRLY FLOW AS THE MAIN UPPER LEVEL FEATURE ACROSS THE
PLAINS. WITHIN THE NWRLY FLOW THERE ARE WEAK VORTS THAT ARE DIFFICULT
TO FCST BOTH SPACIALLY AND TEMPORALLY.

AT THE SFC...MAIN TROF EXTNDD FROM SWRN MN TO ERN KS AND TO CNTRL
OK. EARLIER CONVECTION LEFT OUTFLOW BOUNDARY FROM SERN KS TO XTRM
SWRN MO AND SCNTRL MO. MOST ACTIVE CONVECTION OF THE DAY TOOK PLACE
ALONG THIS BOUNDARY EARLIER THIS AFTN. ELSEWHERE CU FIELD FORMED ALG
TROF AXIS AND ALG OUTFLOW BOUNDARY...WITH IMPRESSIVE CELL IN THE
VCNTY OF MKC. WITH COOL TEMPS ALOFT AND DAYTIME HTG OF UNSTABLE AIR
MASS...WILL PLACE POPS IN FOR THIS EVENING.

THINK THAT WITH THE LOSS OF DAYTIME HEATING LATER THIS EVENING...ANY
TSTMS OR SHWRS WILL DISSIPATE TWDS MIDNGT. WILL LEAVE MENTION OF PCPN
OUT FOR THE OVERNGT PERIOD...DUE MAINLY TO THE LACK OF UPPER LEVEL
SUPPORT...DESPITE WAA PATTERN AT 850MB. OTHER FACTOR FOR TNGT IS THE
PSSBLTY OF FOG. THINK THAT WITH LOSS OF CU...SKIES WILL BE MSTLY CLR.
WEAK PRESSURE GRADIENT WILL ALLOW FOR LIGHT WINDS...AND WITH DWPT
AXIS ALG AND AHEAD OF SFC TROF...SOME PATCHY FOG SHOULD FORM OVERNGT.
FOG COULD BE LOCALLY DENSE IN THE USUAL LOW LYING AREAS.

NGM FCSTS UPPER LVL NWRLY JET TO INCRS ACROSS THE PLAINS ON MONDAY.
THIS WILL FORCE SFC TROF TO MOVE NW TO SE ACROSS THE CWFA BY MON NGT.
SFC FLOW IS FCST TO BE SWRLY AHEAD OF TROF...SO NOT THE BEST FOR
CONVERGENCE...BUT NEVER THE LESS...DAYTIME HEATING OF MOIST UNSTABLE
AIR MASS ALONG THE TROF WILL HELP TO FIRE OFF A FEW TSTMS ACROSS THE
CWFA. INCRSG SHEAR ALFT MAY ALSO LEAD TO A FEW SVR TSTMS.

THERMAL RIDGE WILL ACCOMPANY THE SFC TROF. 850MB TEMPS ARND 18 DEG C
WOULD LEAD TO MIDDLE 80S FOR HIGHS...HOWEVER WITH SOME CLOUD DVLPMNT
EXPECTED WILL TEND TO BACK OFF A LITTLE AND GO WITH LOWER 80S...THIS
IS A LITTLE BELOW FWC AND FAN TEMPS. FWC AND FAN POPS ARE A BIT LOW
SO WILL GO WITH AT LEAST A 40 PCT POP ON MONDAY.

SFC TROF PASSAGE BY EARLY MON NGT WILL NOT LEAD TO COOLER TEMPS BUT
WITH SOMEWHAT DRIER AIR. THAT SHOULD ALLEVIATE THE FOG THREAT FOR
MON NGT.

THE WX APPEARS TO GET INTERESTING BY TUESDAY NIGHT INTO WEDNESDAY.
VIGOROUS UPPER LOW WITH STG UPPER JET WILL SWING THRU NRN PLAINS.
AVN FCSTS GOOD FLOW OF MOIST SFC AIR NWD INTO IOWA. LOOKS LIKE THE
CWFA WILL BE CAPPED BUT STORMS WILL PROBLY FIRE NICELY ACROSS THE
NRN PLAINS. OTRW MUCH WARMER TEMPS ARE EXPECTED ON TUES WITH 850MB
TEMPS WELL INTO THE 20S DEG C. FWC AND FAN TEMPS FOR TUES LOOK OK.

IN THE EXTENDED PERIOD...COLD FRONT ASSOC WITH VIG UPPER LOW...IS
FCST BY MRF TO MOVE INTO THE CWFA. THIS MAY LEAD TO A CHC OF PCPN
ALTHOUGH ATMOSPHERE MAY BE CAPPED. MRF THEN FCSTS FRONT TO LIFT NWD
ON FRI. FMR POPS ARE RATHER HIGH ON FRI AND WILL TEND TO LEAVE
MENTION OF PCPN OUT FOR FRI SINCE MAIN UPPER TROF...AND HENCE BEST
UPPER SUPPORT...IS FCST TO BE FROM MT TO AZ.

CCF NUMBERS...
SGF BU 057/081 059/089 065 124410
JLN BU 058/084 060/091 065 124410
UNO BU 055/080 060/087 065 124410
VIH BU 056/081 059/089 065 124410=

.SGF...NONE.

D.STEINMETZ

KSZ073-097-101-MOZ055>058-066>071-077>083-088>098-101>106-221100-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE SPRINGFIELD MO
100 PM CDT SUN MAY 21 2000

...A FEW SEVERE THUNDERSTORMS POSSIBLE THIS AFTERNOON AND EARLY
EVENING...

AN UPPER LEVEL DISTURBANCE...THAT WAS OVER WESTCENTRAL MISSOURI...
EARLY SUNDAY AFTERNOON...CONTINUED TO CAUSE SCATTERED SHOWERS AND
THUNDERSTORMS ACROSS THE REGION. THIS DISTURBANCE WILL MOVE EAST
AND AWAY FROM THE REGION BY MID TO LATE AFTERNOON...RESULTING IN
A DECREASE IN THE AREAL COVERAGE OF RAIN.

HOWEVER DAYTIME HEATING OF WARM AND MOIST AIR...AT THE SURFACE...
UNDERNEATH A COLD AIR MASS ALOFT...WILL RESULT IN WIDELY SCATTERED
TO ISOLATED THUNDERSTORMS THIS AFTERNOON AND EARLY EVENING. THERE
IS A POSSIBILITY THAT A FEW OF THE THUNDERSTORMS COULD BECOME
SEVERE.  ESPECIALLY OVER EXTREME SOUTHEAST KANSAS AND SOUTHWEST AND
SOUTHCENTRAL MISSOURI. THE MAIN THREATS WILL BE HAIL TO THE SIZE OF
NICKELS AND WIND GUSTS TO 60 MPH.

SPOTTER AND EMERGENCY MANAGEMENT ACTIVATION MAY BE NEEDED THIS
AFTERNOON AND EARLY EVENING.

.OUTLOOK FOR MONDAY THROUGH THURSDAY...

ANOTHER SYSTEM WILL MOVE ACROSS THE OZARKS MONDAY WITH A FEW SEVERE
THUNDERSTORMS POSSIBLE OVER SOUTHCENTRAL MISSOURI. OTHERWISE NO
HAZARDOUS WEATHER IS EXPECTED FOR THE REMAINDER OF THE PERIOD.

FOR OTHER PRODUCTS ISSUED BY THE NATIONAL WEATHER SERVICE AT
SPRINGFIELD MO...CHECK OUR WEB SITE AT HTTP://WWW.CRH.NOAA.GOV/SGF.

D.STEINMETZ

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SPRINGFIELD MO
123 PM CDT SUN MAY 21 2000

TIME(CDT)  .....CITY LOCATION..... STATE  ...EVENT/REMARKS...
           ....COUNTY LOCATION....

1240 PM    WHEELERVILLE              MO   .75 INCH HAIL
05/21/00   BARRY                          REPORTED BY
                                          PUBLIC(AGTAP).