Area Forecast Discussion
Issued by NWS St. Louis, MO

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000
FXUS63 KLSX 031627
AFDLSX

AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE ST LOUIS MO
1127 AM CDT MON AUG 3 2015

.SHORT TERM:  (THROUGH LATE THIS AFTERNOON)
ISSUED AT 316 AM CDT MON AUG 3 2015

SURFACE FRONT EXTENDS FROM NORTHERN ILLINOIS THROUGH SOUTHERN
IOWA INTO FAR NORTHWESTERN MISSOURI AT THIS HOUR. THIS FRONT WILL
MOVE SOUTH TODAY AND BEGIN TO REALIGN ITSELF UNDER THE
NORTHWESTERLYUPPER FLOW ALOFT SO THAT IT WILL EXTEND FROM
CENTRAL MISSOURI INTO SOUTHEAST MISSOURI BY LATER THIS AFTERNOON.
WHILE THERE WILL NOT BE ANY SIGNIFICANT SHORTWAVE TROUGHS MOVING
THROUGH THE AREA TODAY TO PROVIDE ENHANCED ASCENT ALONG THE
FRONT...THERE WILL BE ENOUGH LOW LEVEL CONVERGENCE ALONG IT TO
SUPPORT GOING SLIGHT CHANCES. MLCAPES BY LATER THIS AFTERNOON WILL
BE IN THE 2000-3000 J/KG RANGE.

TEMPERATURES WILL STILL BE WARM AHEAD OF THE FRONT IN THE SOUTHERN
CWA WHERE MIXING WILL BE ABOVE 850MB.  TEMPERATURES WILL STILL
LIKELY BE IN THE LOWER TO MIDDLE 90S ALONG AND SOUTH OF I-70 AHEAD
OF THE COLD FRONT WHERE MIXING WILL BE ABOVE 850MB.

BRITT

.LONG TERM:  (TONIGHT THROUGH SUNDAY)
ISSUED AT 316 AM CDT MON AUG 3 2015

(TONIGHT THROUGH WEDNESDAY)

THE SURFACE FRONT WILL MOVE SOUTH OF THE AREA BY TUESDAY MORNING AND
REMAIN SOUTH OF THE AREA THROUGH WEDNESDAY.  RAIN CHANCES WILL BE
GREATER TONIGHT INTO TUESDAY AS BOTH THE NAM AND GFS ARE SHOWING AN
INCREASE IN LOW LEVEL MOISTURE CONVERGENCE OVERNIGHT OVER NORTHEAST
AND EAST CENTRAL MISSOURI OVERNIGHT.  BY TUESDAY AND WEDNESDAY...TWO
SIGNIFICANT SHORTWAVE TROUGHS WILL MOVE ACROSS MISSOURI AND
ILLINOIS WITH A CORRESPONDING INCREASE IN LOW LEVEL MOISTURE
CONVERGENCE. THIS JUSTIFIES THE GOING HIGH CHANCE OR LIKELY
CHANCES FOR THUNDERSTORMS.

(THURSDAY THROUGH SUNDAY)

WAVY FRONT WILL REMAIN OVER THE AREA AT LEAST THROUGH FRIDAY
KEEPING THUNDERSTORM CHANCES IN THE FORECAST. HEIGHTS WILL
INCREASE OVER THE AREA BY THE WEEKEND WITH 850MB TEMPERATURES NEAR
20C. THIS SHOULD CAUSE TEMPERATURES TO CLIMB BACK ABOVE NORMAL.

BRITT

&&

.AVIATION:  (FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1114 AM CDT MON AUG 3 2015

COLD FRONT HAS SAGGED INTO NORTHERN MO TO CENTRAL IL. FRONT IS
SOMEWHERE BETWEEN STL AND UIN WITH WEAK WINDS MAKING IT HARD TO
PICK OUT. THUNDERSTORMS CONTINUE TO DEVELOP NORTH AND NORTHWEST OF
KANSAS CITY. LOOKS LIKE THE BEST AREAS WILL BE ACROSS THE
SOUTHWEST HALF OF MO AND SOUTERN IL BUT CANNOT RULE OUT SOMETHING
ANYWERE ALONG THE FRONT AS ATMOSPHERE CONTINUES TO DESTABILIZE
THIS AFTERNOON. LOOKS LIKE UIN WILL BE FAR ENOUGH NE TO KEEP THE
FORECAST DRY WITH A VCTY AT COU, SUS AND CPS. LOOKS LIKE INHIBITION
WILL BE ENOUGH TO KEEP OVERNIGHT DRY EVEN THOUGH THE MODELS KEEP
SCATTERED STUFF GOING. IF THE LOW LEVEL JET IS STRONG ENOUGH WOULD
NOT BE SURPRISED TO SEE SOME ELEVATED STORMS BUT WILL STAY DRY
GIVEN LOW PROBALILITIES. TUESDAY LOOKS TO BE A REPEAT WITH THE
FRONT STILL IN THE AREA AND SCATTERED STORMS FORMING ALONG THE
FRONT.

SPECIFICS FOR KSTL: WITH THE COLD FRONT IN THE AREA CANNOT RULE
OUT A THUNDERSTORM THIS AFTERNOON SO WILL THROW IN A VCTY WITH A
REPEAT FOR TUESDAY AFTERNOON. WIND LOOKS TO BE ALL OVER THE PLACE
FROM WEST TO EAST THIS AFTERNOON THROUGH TUESDAY WITH SPEEDS
AROUND 5 KNOTS.

JPK

&&

.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&

$$

WFO LSX



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