Area Forecast Discussion
Issued by NWS St. Louis, MO

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000
FXUS63 KLSX 052359
AFDLSX

AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE ST LOUIS MO
659 PM CDT SUN JUL 5 2015

.SHORT TERM: (TONIGHT THROUGH MONDAY)
ISSUED AT 331 PM CDT SUN JUL 5 2015

THE EVENING LOOKS RATHER TRANQUIL ACROSS THE REGION WITH
DISSIPATING DIURNAL CU AND A FEW HIGH CLOUDS FILTERING ACROSS THE
AREA. THE RETURN OF SOUTHERLY LOW LEVEL FLOW HAS LEAD TO WARMER
TEMPERATURES TODAY AND GREATER MOISTURE. OVERNIGHT THERE ARE
INDICATIONS BY THE NAM AND ESPECIALLY THE RAP THAT WE MAY SEE SOME
SPOTTY ELEVATED SHOWERS AND THUNDERSTORMS FROM SOUTH CENTRAL MO
INTO EAST CENTRAL AND SOUTHEAST MO IN THE NEAR DAWN HOURS, THEN
SHIFTING EAST ON MONDAY MORNING. A VERY WEAK PETURBATION IN THE
NORTHWEST FLOW ALOFT, AND MORE IMPORTANTLY VEERING AND STRENGTHENING
LOW-LEVEL FLOW IN THE 3000-7000 FT LAYER AND ATTENDANT THERMAL AND
MOISTURE ADVECTION COULD GENERATE SOME ACTIVITY IN THE 07-15Z TIME
FRAME. I HAVE ADDED SOME SLIGHT CHANCE POPS TO THE FORECAST WITH
THIS IN MIND. OTHERWISE MILDER TEMPERATURES ON TAP TONIGHT AND A
RATHER WARM DAY IS ON SCHEDULE FOR MONDAY. THE MODELS NOW ALL HAVE
A BIT SLOWER PROGRESS WITH THE COLD FRONT, NOT ENTERING FAR
NORTHWEST MO UNTIL THE 21-00Z TIME FRAME. GIVEN THIS SLOWER SPEED
AND LESSER CLOUDS EXPECTED WITH THE FORECAST WAA REGIME, I EXPECT
TEMPERATURES WELL INTO THE 80S WITH A FEW SPOTS AROUND 90. WE
COULD ALSO SEE SOME SPOTTY DIURNALLY DRIVEN PULSE STORMS IN THE
AFTERNOON IN THE BROAD WARM MOIST AND UNSTABLE WARM SECTOR.

GLASS

.LONG TERM: (MONDAY NIGHT THROUGH NEXT SUNDAY)
ISSUED AT 331 PM CDT SUN JUL 5 2015

MONDAY NIGHT INTO WEDNESDAY STILL LOOKS LIKE A WET AND STORMY
PATTERN WITH WIDESPREAD MULTI-DAY AVERAGE RAINFALL TOTALS OF 2-4
INCHES. THE BIGGEST ISSUE IS JUST WHERE THE HEAVIEST RAINFALL MAY
FOCUS WITH THE MODELS HAVING SOME GROWING DIFFERENCES WITH TIME
FROM TUESDAY AND BEYOND WHERE THE FRONT MAY LIE. THE ECMWF HAS THE
MOST AGRESSIVE SOUTHWARD PUSH EARLY ON THEN WAVERS THE FRONT
THROUGH THE AREA LATE THIS WEEK. ALTERNATIVELY THE GFS AND NAM
BOTH DON`T MOVE THE FRONT AS FAR SOUTH AND THEN WAVER IT TUESDAY
NIGHT INTO WEDNESDAY AS SURFACE WAVES MOVE ALONG IT, FINALLY
PUSHING NORTH OF THE CWA BY THURSDAY EVENING. THE REGION SPANNING
THE FRONTAL ZONE WILL BE VERY MOIST AND A BROAD REGION OF DEEP LOW
LEVEL CONVERGENCE WILL FOCUS WIDESPREAD SHOWERS AND THUNDERSTORMS
WITH POTENTIAL FOR HEAVY RAIN. WE MAY ULTIMATELY NEED A FLASH
FLOOD WATCH ONCE WE CAN PIN DOWN THE REGION A BIT BETTER.

LOOKS LIKE PRECIPITATION CHANCES WILL DECREASE INTO NEXT WEEKEND
WITH A RETURN OF SUMMER HEAT.

GLASS

&&

.AVIATION:  (FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 639 PM CDT SUN JUL 5 2015

VFR FLIGHT CONDITIONS ARE EXPECTED TO PREVAIL WITH SOME POCKETS OF
MVFR HAZE DEVELOPING AFTER SUNSET. THINK MVFR VSBYS WILL CONTINUE
TO SPREAD OVERNIGHT...THOUGH VSBYS WILL PROBABLY NOT BE AS LOW AS
LAST NIGHT WITHOUT SMOKE FROM FIREWORKS AND INCREASING SOUTHEAST
FLOW. AM SOMEWHAT CONCERNED THAT A STRATUS LAYER COULD DEVELOP
OVER THE OZARKS AND MOVE NORTH ACROSS PARTS OF CENTRAL INTO
EASTERN MISSOURI OVERNIGHT. THIS LAYER COULD BE VERY LOW...AT OR
BELOW 1,500 FT. AM NOT CONFIDENT ENOUGH TO INTRO THIS INTO THE
TAFS AT THIS TIME, BUT WILL WATCH CLOSELY FOR SIGNS AND UPDATE AS
NECESSARY. ADDITIONALLY, THERE IS A CHANCE FOR ISOLATED SHOWERS
AND POSSIBLY A THUNDERSTORM OR TWO AROUND SUNRISE AND CONTINUING
INTO MID-MORNING. AS ANY SHOWERS/STORMS THAT DO FORM WILL LIKELY
BE LIGHT AND VERY ISOLATED, HAVE NOT INCLUDED IN THE TAFS AT THIS
TIME. MONDAY SHOULD BE VFR AFTER ANY LINGERING FOG/HAZE/STRATUS
DISSIPATES WITH INCREASING SOUTH-SOUTHWEST FLOW.

SPECIFICS FOR KSTL:

EXPECT HAZY CONDITIONS TO CONTINUE AT LAMBERT...AND VSBY TO DROP
INTO MVFR RANGE THIS EVENING. THINK IFR VSBYS ARE VERY UNLIKELY
TONIGHT DUE TO HIGHER WIND AND LOW LEVEL MIXING...NOT TO MENTION
LACK OF FIREWORKS. A LAYER OF STRATUS MAY DEVELOP OVER THE OZARKS
LATE TONIGHT AND SWEEP OVER PARTS OF CENTRAL AND EASTERN MISSOURI.
THIS LAYER COULD BE VERY LOW...AT OR BELOW 1,500 FT. AM NOT
CONFIDENT ENOUGH TO INTRO THIS INTO THE TAF AT THIS TIME, BUT
WILL WATCH CLOSELY FOR SIGNS AND UPDATE AS NECESSARY.
ADDITIONALLY, THERE IS A CHANCE FOR ISOLATED SHOWERS AND POSSIBLY
A THUNDERSTORM OR TWO AROUND SUNRISE AND CONTINUING INTO MID-
MORNING. AS ANY SHOWERS/STORMS THAT DO FORM WILL LIKELY BE LIGHT
AND VERY ISOLATED, HAVE NOT INCLUDED IN THE TAF AT THIS TIME.
MONDAY SHOULD BE VFR AFTER ANY LINGERING FOG/HAZE/STRATUS
DISSIPATES WITH INCREASING SOUTH-SOUTHWEST FLOW.

CARNEY

&&

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

$$

WFO LSX


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