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000
FXUS63 KLSX 170436
AFDLSX

AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE ST LOUIS MO
1136 PM CDT SUN JUN 16 2013

.UPDATE...
ISSUED AT 942 PM CDT SUN JUN 16 2013

THE PRESENCE OF A WEAK LARGE SCALE BOUNDARY EXTENDING FROM SOUTHWEST
IL THROUGH METRO ST LOUIS INTO SW MO AND A VERY UNSTABLE AIRMASS
ALLOWED FOR SCATTERED DIURNALLY DRIVEN PULSE THUNDERSTORMS TO FORM
LATE THIS AFTERNOON INTO EARLY THIS EVENING. THESE STORMS WERE
MAINLY S/SW OF ST LOUIS YET THERE CUMULATIVE OUTFLOWS HAVE ALLOWED
A CONTINUATION OF SCATTERED PULSE STORMS TO DEVELOP PROGRESSIVELY
FURTHER NORTH INSPITE OF DIMINISHING INSTABILITY. I SUSPECT THESE
STORMS WILL GRADUALLY DIMINISH IN COVERAGE OVER THE NEXT FEW
HOURS...BUT THE PRESENCE OF THE WEAK Q-STNRY BOUNDARY WILL
SUPPORT A CHANCE OF THUNDERSTORMS THROUGH THE OVERNIGHT HOURS.

AT THIS TIME IT APPEARS ANY MCS THREAT THROUGH THE OVERNIGHT HOURS
WILL REMAIN TO THE WEST OF THE CWA. AN MCS OVER WESTERN KS AND
ANOTHER MOVING SEWD OUT OF CENTRAL NEBRASKA SHOULD TRACK SEWD
THROUGH KS AND OK WITH POSSIBLY SOME NEW ACTIVITY SKIRTING WESTERN
MO.

GLASS
&&

.SHORT TERM...(TONIGHT THROUGH WEDNESDAY)
ISSUED AT 252 PM CDT SUN JUN 16 2013

EYES FOCUSED TO OUR WEST WHERE ONE OR MORE MCS WILL DEVELOP
TONIGHT AND TRACK SOUTHEAST TOWARD THE LOWER MISSOURI RIVER
VALLEY AND OZARKS REGION AFTER 06Z. SHORT TERM MODEL GUIDANCE IS
REALLY ALL OVER THE PLACE IN REGARDS TO PLACEMENT AND TRACK OF
THESE SYSTEMS. GENERALLY HAVE RAMPED UP POPS AFTER 06Z...THINKING
THAT THERE MAY BE SOME CONVECTION DEVELOPING ON THE WARM ADVECTION
WING AHEAD OF THE APPROACHING MCS. HAVE MAINTAINED LIKELY POPS
ACROSS THE SOUTHERN HALF OF THE CWA ON MONDAY AS WEAKENING
CONVECTIVE SYSTEM OR REMNANT CIRCULATION MOVES EAST ACROSS THE
CWA.

SURFACE HIGH PRESSURE WILL THEN BUILD SOUTH INTO THE REGION
ON TUESDAY AND WEDNESDAY WITH SLIGHTLY BELOW AVERAGE TEMPERATURES
A DRY CONDITIONS EXPECTED.

CVKING

.LONG TERM...(THURSDAY THROUGH NEXT SUNDAY)
ISSUED AT 252 PM CDT SUN JUN 16 2013

A TRANSITION FROM A RELATIVELY COOL NORTHWEST FLOW ALOFT TO A
MORE SUMMER LIKE UPPER LEVEL RIDGE BUILDING INTO THE MID SECTION
OF THE COUNTRY WILL TAKE PLACE. COULD SEE A COUPLE CHANCES OF
THUNDERSTORMS THURSDAY AND FRIDAY BEFORE THE RING OF FIRE LIFTS
NORTH OF THE CWA. OTHERWISE...AFTERNOON HIGH TEMPERATURES WILL
RISE INTO THE 90S BY NEXT WEEKEND.

CVKING
&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1136 PM CDT SUN JUN 16 2013

THUNDERSTORMS CONTINUE TO FIRE UP ALONG A WEAK BOUNDARY THAT IS
LAID OUT ACROSS FORECAST AREA. AS OF 0430Z...STORMS WERE OVER
CENTRAL AND SOUTHERN MO. SO ADDED MENTION TO KCOU TAF THROUGH 09Z.
REST OF AREA TO REMAIN DRY THROUGH DAYBREAK...THOUGH SOME ISOLATED
ACTIVITY NOT OUT OF THE QUESTION IN THE STL METRO AREA. MAIN ISSUE
IN THE SHORT TERM WILL BE FOG FORMATION DUE TO PLENTY OF LOW
LEVEL MOISTURE AND LIGHT WINDS. KCOU AND KSUS TO SEE VSBYS DIP
DOWN TO IFR BRIEFLY OTHERWISE...JUST EXPECT MVFR VSBYS IN FOG
THROUGH DAYBREAK. AS FOR REST OF FORECAST PERIOD...STILL SOME
UNCERTAINTY TO EXACT TRACK OF MCS THAT IS CURRENTLY OVER
KS...BEST BET TO REMAIN WEST OF FORECAST AREA WITH KCOU ON EASTERN
EDGE...SO KEPT VCTS MENTION AT KCOU AFTER 15Z. WITH BOUNDARY
LINGERING OVER REGION DURING THE DAY ON MONDAY...COULD SEE
SCATTERED STORMS FIRE UP MAINLY ALONG AND SOUTH OF I-70...BUT
CONFIDENCE IS LOW ON COVERAGE...SO KEPT METRO AREA TAFS DRY FOR
NOW.

SPECIFICS FOR KSTL...THUNDERSTORMS HAVE DIMINISHED OVER METRO
AREA...SO TO REMAIN DRY THROUGH DAYBREAK...THOUGH SOME ISOLATED
ACTIVITY NOT OUT OF THE QUESTION. MAIN ISSUE IN THE SHORT TERM
WILL BE FOG FORMATION DUE TO PLENTY OF LOW LEVEL MOISTURE AND
LIGHT WINDS. KSUS TO SEE VSBYS DIP DOWN TO IFR BRIEFLY.
OTHERWISE...JUST EXPECT MVFR VSBYS IN FOG THROUGH 13Z AT KSTL. WITH
BOUNDARY LINGERING OVER REGION DURING THE DAY ON MONDAY...COULD
SEE SCATTERED STORMS FIRE UP MAINLY ALONG AND SOUTH OF I-70...BUT
CONFIDENCE IS LOW ON TIMING AND COVERAGE...SO KEPT METRO AREA TAFS
DRY FOR NOW.

BYRD
&&

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

$$

WFO LSX