Severe Thunderstorm Warning 465, NWS St. Louis, MO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ST LOUIS MO
300 PM CDT WED OCT 4 2000

18Z SFC ANALYSIS PLACED SFC FRONT ROUGHLY ALONG A MVN-FAM-TBN LINE.
MODELS LOOK TO BE IN OVERALL AGREEMENT IN HOLDING THE FRONT NEARLY
STATIONARY AS TWO WEAK SFC LOWS NOW OVER OK CONSOLIDATE AND MOVE NE
ALONG IT.  THIS LACK OF MOVEMENT LOOKS GOOD GIVEN LACK OF RISING
PRESSURE NORTH OF FRONT.  LOW LEVEL JET WILL BACK AND INCREASE TO
35 KTS PROVIDING DECENT LOW LEVEL MOISTURE CONVERGENCE AND THETA-E
ADVECTION NORTH OF SFC FRONT THIS EVENING INTO THE OVERNIGHT.
CURRENT CATEGORICAL AND LIKELY WORDING IN CURRENT ZONES LOOK GOOD.
SHOWALTER'S SHOULD BE AOB -2 WITH 0-6KM SHEAR AOA 40KTS...BRINGING
SOME SEVERE POTENTIAL PER SWODY1.  PW'S ALSO INCREASE UP TO 1.80
INCHES OVER CNTRL MO...INDICATING SOME POTENTIAL FOR LOCALLY HEAVY
RAINFALL.  HIGH FFG VALUES AND CORFIDI/MEAN WIND VECTORS PRECLUDE
NEED FOR FLASH FLOOD WATCH AS LOW LEVEL JET THEN VEERS BACK WLY
TOWARD MORNING.

FRONT WILL THEN MOVE SOUTH TOMORROW AS LOW MOVES EAST OF THE AREA.
FRONTOGENTICAL FORCING BEHIND FRONT INCREASES AND SHIFTS SOUTH
DURING THE DAY...SO WILL NEED TO KEEP THE LIKELY AND CATEGORICAL
POPS TOMORROW.  AVN IS ONLY MODEL THAT TRIES TO KEEP PRECIP GOING
THURSDAY NIGHT INTO FRIDAY...BUT DIVERGENCE AND OMEGA FIELDS LOOK
OVERDONE.  WILL KEEP SOME CHANCE OF RAIN WITH POST FRONTAL PRECIP IN
SOUTHERN PART OF CWFA...BUT LACK OF MID LEVEL FORCING AND FRONT
MOVING FARTHER SOUTH WOULD DISCOUNT THE AVN SOLUTION.

TEMPS ARE A BIG ISSUE WITH THIS PACKAGE. TEMPS ARE TRICKY TONIGHT
BECAUSE OF FRONT PROXIMITY AND LOW CLOUDS.  GUIDANCE TEMPS ARE TOO
WARM WITH CURRENT TEMPS...SO WILL PROBABLY JUST GO WITH LOWS A
CATEGORY BELOW CURRENT TEMPS NORTH OF THE FRONT AND NEAR GUIDANCE TO
THE SOUTH.  WITH LOW CLOUDS AND STRONG LOW LEVEL CAA...WILL NEED TO
USE FALLING TEMPS TOMORROW. SOME CLOUDS AND WIND ON FRIDAY MORNING
MAY PREVENT FROST THREAT BECAUSE OF WINDS AND CLOUDS.

IN THE EXTENDED...MEDIUM RANGE MODELS LOOK TO BE IN REASONABLE
AGREEMENT WITH MASS FIELDS AT SFC AND 500 MB.  UPPER LOW OVER THE
GREAT LAKES ON SATURDAY MORNING WILL SHIFT INTO QUEBEC BY MONDAY.
1045 MB HIGH OVER THE DAKOTAS ON SATURDAY MORNING WILL WEAKEN AND
MOVE INTO THE SERN U.S..  FORCING FOR PRECIP SHOULD BE CLEAR OF AREA
LEAVING A DRY BUT COOL EXTENDED.  850 MB TEMPS SUGGEST GOING A BIT
ABOVE MRF OBJECTIVET TEMP GUIDANCE.

.STL...NONE

BRITT
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PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE ST LOUIS MO
957 AM CDT WED OCT 04 2000

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

855 AM     GREENVILLE                IL   0.88 INCH HAIL
10/04/00   BOND                           DIME TO NICKEL SIZED HAIL
                                          REPORTED BY SEVERE
                                          WEATHER SPOTTER.

ILZ058>060-064-065-069-070-074-079-095>102-MOZ018-019-026-027-
034>036-041-042-047>052-059>065-072>075-084-085-099-051100-

SEVERE WEATHER OUTLOOK
NATIONAL WEATHER SERVICE ST LOUIS MO
1209 PM CDT WED OCT 4 2000

THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON
AND TONIGHT ALONG AND SOUTH OF A ROLLA TO ST. LOUIS TO LITCHFIELD
LINE. SPOTTER ACTIVATION MAY BE NEEDED IN THESE AREAS.

A COLD FRONT WILL BECOME NEARLY STATIONARY TODAY OVER THE SOUTHERN
AND EASTERN PARTS OF THE AREA.  THIS FRONT IS EXPECTED TO PRODUCE
SCATTERED THUNDERSTORMS THROUGH TONIGHT.  A FEW OF THESE STORMS MAY
BECOME SEVERE...WITH THE PRIMARY THREAT BEING LARGE HAIL AND LOCALLY
DAMAGING WINDS.
@
THIS OUTLOOK WILL BE UPDATED AS NEEDED.

THIS OUTLOOK COVERS THE COUNTY WARNING AREA OF THE NATIONAL WEATHER
SERVICE OFFICE IN ST LOUIS.  AREAS INCLUDED ARE PORTIONS OF CENTRAL
AND EASTERN MISSOURI AND SOUTHWEST ILLINOIS.

BRITT