Area Forecast Discussion
Issued by NWS St. Louis, MO

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000
FXUS63 KLSX 062034
AFDLSX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ST LOUIS MO
334 PM CDT MON JUL 6 2015

.SHORT TERM:  (THROUGH LATE TONIGHT)
ISSUED AT 320 PM CDT MON JUL 6 2015

TRANQUIL WEATHER HAS COME TO AN END. HEATING OF THE VERY MOIST
AIR MASS HAS PRODUCED SBCAPE OF 3000-4000 J/KG WHICH ALONG WITH A
WEAK UPPER DISTURBANCE TRACKING INTO EASTERN MO HAS GENERATED
SCATTERED THUNDERSTORMS ACROSS THE SOUTHEAST HALF OF THE CWA. PWS
OF 1.6-1.8 INCHES IS RESULTING IN HEAVY DOWNPOURS WITH STORMS,
AND PRESENCE OF SUFFICIENTLY STEEP LOW LEVEL LAPSE RATES AND
PRECIPIP LOADING IS ALSO AIDING IN PROMINENT OUTFLOWS AND GUSTY
SURFACE WINDS. SOME OF THIS ACTIVITY WILL LINGER INTO THE EARLY
EVENING PRIMARILY FROM ST. LOUIS EAST, BUT THE MAIN SHOW WILL BE A
GROWING EXTENSIVE BAND OF SHOWERS AND THUNDESTORMS CURRENTLY
EXTENDING FROM NORTHWEST MO INTO EASTERN KS. THIS ACTIVITY WILL
MOVE EAST AND SINK SOUTH WITH TIME TONIGHT. THE GREATEST THREAT OF
HEAVY RAIN WILL BE CENTERED IN NORTHEAST MO AND WEST CENTRAL IL
TRAILING INTO CENTRAL MO AND MAINLY THIS EVENING. THE CURRENT
FLASH FLOOD WATCH HAS THIS WELL COVERED. THE SEVERE WEATHER
THREAT WILL OCCUPY THE SAME GENERAL REGION AND TIME SPACE AND WILL
LARGELY BE DRIVEN BY THE AFOREMENTIONED INSTABILITY WITH MARGINAL
DEEP LAYER SHEAR SUPPORTING A MULTICELL MODE AND WIND DAMAGE
THREAT.

GLASS

.LONG TERM:  (TUESDAY THROUGH NEXT MONDAY)
ISSUED AT 320 PM CDT MON JUL 6 2015

THE SCENARIO HAS CHANGED LITTLE TUESDAY INTO WEDNESDAY WITH THE
FRONT GRADUALLY MOVING SOUTHWARD AND BECOMING STATIONARY ACROSS
SOUTHERN ILLINOIS AND SOUTHEAST MISSOURI BY TUESDAY EVENING, AND
THEN WAVERING BACK NORTH LATE TUESDAY NIGHT-WEDNESDAY WITH THE
MOVEMENT AND PASSAGE OF A SURFACE LOW MIGRATING ALONG THE FRONT.
BROAD DEEP LOW LEVEL CONVERGENCE ATTENDANT WITH THE FRONTAL ZONE
ALONG WITH AMPLE INSTABILITY AND ABUNDANT MOISTURE /PWS IN EXCESS
OF 2 INCHES/ SUPPORT THE FORECAST OF WIDESPREAD SHOWERS AND
THUNDESTORMS WITH A HEAVY RAINFALL THREAT. THE CURRENT FLASH FLOOD
WATCH COVERS THIS PERIOD WITH MULTIDAY RAINFALL TOTALS OF 2-4
INCHES EXPECTED AND LOCALLY HIGHER TOTALS. ULTIMATELY THE WATCH
MAY NEED TO BE EXTENDED INTO WEDNESDAY NIGHT-THURSDAY NIGHT PERIOD
WITH ANOTHER AND THE FINAL SURFACE WAVE MOVING ALONG THE FRONT.

THE FRONT FINALLY PUSHES NORTH OF THE AREA BY EARLY FRIDAY PUTTING
AN END TO THE PRECIPITATION FOR SEVERAL DAYS. SUMMER HEAT AND HUMIDITY
IS ON TAP FOR NEXT WEEKEND AS HEIGHTS RISE ALOFT AND A PROMINENT
UPPER RIDGE BUILDS THROUGH THE NATIONS MIDSECTION.

GLASS

&&

.AVIATION:  (FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1242 PM CDT MON JUL 6 2015

WIDELY SCATTERED SHOWERS/STORMS HAVE DEVELOPED BETWEEN VIH AND STL
THIS AFTERNOON. THIS ACTIVITY WILL CONTINUE TO DEVELOP DUE TO DAYTIME
HEATING AND WILL IMPACT THE ST LOUIS METRO AREA AND POSSIBLY ALSO
COU AS WELL. A COLD FRONT EXTENDING FROM A SURFACE LOW OVER
WESTERN WI SOUTHWEST INTO THE OK PANHANDLE WILL MOVE SOUTHEASTWARD
THROUGH UIN AROUND 00Z TUESDAY, COU AROUND 06Z TUESDAY, AND THE ST
LOUIS METRO AREA BETWEEN 09-12Z TUESDAY. SHOWERS AND THUNDERSTORMS
ARE EXPECTED ALONG AND JUST BEHIND THIS FRONT. THE WIND WILL ALSO
VEER AROUND TO A NWLY DIRECTON AFTER FROPA LATE TONIGHT AND EARLY
TUESDAY MORNING. THE CLOUD CEILING WILL LOWER TO AROUND 1000 FEET
LATE TONIGHT/EARLY TUESDAY MORNING DUE TO POST FRONTAL STRATUS
CLOUDS.

SPECIFICS FOR KSTL: SCATTERED DIURNAL SHOWERS/STORMS WILL LIKELY
IMPACT STL THIS AFTERNOON INTO THE EARLY EVENING HOURS. THERE WILL
LIKELY BE A BRIEF BREAK IN THE RAIN THREAT LATER THIS EVENING,
THEN A WEAKENING LINE OR BAND OF CONVECTION SHOULD DROP
SOUTHEASTWARD INTO STL LATE TONIGHT ALONG A COLD FRONT. THIS FRONT
SHOULD MOVE THROUGH STL JUST BEFORE 12Z TUESDAY. THE WIND WILL
VEER AROUND TO A NWLY DIRECTION AFTER FROPA WITH THE CLOUD
CEILING DROPPING TO AROUND 1000 FEET.

GKS

&&

.LSX WATCHES/WARNINGS/ADVISORIES:
MO...FLASH FLOOD WATCH FROM 7 PM CDT THIS EVENING THROUGH WEDNESDAY
     EVENING FOR AUDRAIN MO-BOONE MO-CALLAWAY MO-COLE MO-
     CRAWFORD MO-FRANKLIN MO-GASCONADE MO-JEFFERSON MO-KNOX MO-
     LEWIS MO-LINCOLN MO-MARION MO-MONITEAU MO-MONROE MO-
     MONTGOMERY MO-OSAGE MO-PIKE MO-RALLS MO-SHELBY MO-ST.
     CHARLES MO-ST. LOUIS CITY MO-ST. LOUIS MO-WARREN MO-
     WASHINGTON MO.

IL...FLASH FLOOD WATCH FROM 7 PM CDT THIS EVENING THROUGH WEDNESDAY
     EVENING FOR ADAMS IL-BROWN IL-CALHOUN IL-GREENE IL-JERSEY
     IL-MACOUPIN IL-MADISON IL-MONROE IL-PIKE IL-ST. CLAIR IL.

&&

$$

WFO LSX



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