Area Forecast Discussion
Issued by NWS St. Louis, MO

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FXUS63 KLSX 050843
AFDLSX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ST LOUIS MO
343 AM CDT WED AUG 5 2015

.SHORT TERM: (THROUGH TONIGHT)
ISSUED AT 340 AM CDT WED AUG 5 2015


PRIMARY CONCERN FOR THE TODAY/TONIGHT PERIOD WILL BE ON POSSIBILITY
OF HEAVY RAINFALL. LATEST GUIDANCE HAS COME IN MORE IN LINE WITH THE
OLD EUROPEAN WITH RESPECT TO TRACK OF UPPER-LEVEL IMPULSE COMING
DOWN FROM THE MID-MISSOURI VALLEY AND ITS ASSOCIATED LOW-LEVEL
CYCLONE TRANSVERSING THE BAROCLINIC ZONE. THIS RESULTS IN A TRACK OF
THE SYSTEM FURTHER SOUTH AND SEVERAL HOURS FASTER THAN WHAT IT
LOOKED LIKE 24 HOURS AGO. AS A RESULT...MAIN CHANGES WERE TO LOWER
QPF AMOUNTS...PARTICULARLY ALONG AND NORTH OF THE I-70 CORRIDOR...AS
WELL AS REDUCE POPS FOR LATE TONIGHT. HAVE THEREFORE ELECTED TO TRIM
NORTHERN EXTENT OF THE FLASH FLOOD WATCH INCLUDING THE CITIES OF
COLUMBIA AND ST. LOUIS. IN ADDITION...HAVE FLASH FLOOD WATCH NOW
EXPIRING AT 9Z INSTEAD OF 12Z TO MATCH UP BETTER WITH POP FORECAST
FOR LATE TONIGHT. STILL HAVE CONCERNS THAT MANY COUNTIES IN THE
NORTHERN PORTION OF THE EXISTING WATCH MAY NOT RECEIVE OVERLY HEAVY
RAINFALL WITH FORECAST RAIN AMOUNTS THROUGH TONIGHT ONLY AROUND ONE
INCH BUT DID LEAVE SOME WIGGLE ROOM IN CASE THE HEAVY RAINFALL AXIS
SHIFTS BACK TO THE NORTH AND EAST A BIT. HEAVIEST RAINFALL THROUGH
TONIGHT LIKELY TO BE ACROSS THE FAR SOUTHERN PORTION OF THE
CWA...I.E. REYNOLDS/IRON/MADISON COUNTIES IN MISSOURI WITH UP TO TWO
INCHES OF RAIN POSSIBLE WHERE STRONGEST LOW-LEVEL FORCING WILL
RESIDE THIS EVENING. ANOTHER CONCERN REGARDING THROUGH TONIGHT
IS THAT THERE MAY NOT BE AN ABUNDANCE OF CONVECTIVE ACTIVITY
TYPICALLY NECESSARY FOR HEAVY RAINFALL RATES BOTH THIS MORNING AS
WELL AS OVERNIGHT TONIGHT AS SOME MODEL GUIDANCE SUGGESTS LITTLE TO
NO MUCAPE WELL NORTH OF THE SFC FRONT.

TEMPERATURES WILL NOT MOVE MUCH THROUGH TONIGHT WITH LOW DIURNAL
RANGES DUE TO A LOWERING CLOUD DECK....PRECIPITATION...AND AN
EASTERLY COMPONENT TO THE SFC WIND. HIGHS ARE EXPECTED TO BE IN THE
UPPER 70S TO NEAR 80 DEGREES FOR MOST AREAS WHICH IS A DEGREE OR TWO
BELOW MOS. FOR LOWS TONIGHT...SEASONABLE TEMPS ARE EXPECTED.


GOSSELIN


.LONG TERM:  (TONIGHT THROUGH TUESDAY)
ISSUED AT 340 AM CDT WED AUG 5 2015


(THURSDAY - TUESDAY)

SYSTEM WILL DEPART EARLY ON THURSDAY WITH JUST SOME SCHC/CHC POPS
CONFINED TO THE SOUTHEASTERN EDGE OF THE CWA WITH MID/UPPER LEVEL
SUBSIDENCE SETTING IN BEHIND THE SHORTWAVE TROUGH. CLOUDS SHOULD
LINGER HOWEVER OVER MUCH OF THE AREA WHICH WILL RESULT IN A COOLER
THAN NORMAL DAY WITH HIGHS IN THE LOW TO MID 80S.

A MIDLEVEL ANTICYCLONE WILL STRENGTHEN OVER THE SOUTHERN PLAINS
BEGINNING ON FRIDAY PUTTING THE MID-MISSISSIPPI VALLEY ON THE
NORTHEASTERN PERIPHERY OF THE RIDGE AXIS THROUGH MONDAY.
TEMPERATURE/POPS FORECASTS APPEAR DIFFICULT IN THIS TIME FRAME AS
TIMING OF INDIVIDUAL RIDGE-RUNNER SHORTWAVES IS NEAR IMPOSSIBLE AT
THIS RANGE. HAVE SCHC/CHC POPS EACH DAY/NIGHT WITH NEAR NORMAL
TEMPERATURES...IN OTHER WORDS CLIMATOLOGY FOR TEMPS/POPS. PROBABLY
NOT A BAD GUESS THIS FAR OUT GIVEN THE PATTERN.

ONE FINAL CHANCE OF SHOWERS/STORMS ON MONDAY AS A COLD FRONT LOOKS
TO PUSH SOUTH OF THE AREA WITH THE RIDGE AXIS ALOFT SHIFTING FURTHER
WESTWARD. DRIER AND COOLER AIR APPEARS LIKELY FOR TUESDAY GIVEN THIS
SCENARIO.


GOSSELIN


&&

.AVIATION:  (FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1201 AM CDT WED AUG 5 2015

MAIN AREA OF RAIN FILLING IN OVER SOUTHWEST MO CURRENTLY AND IT
NOW LOOKS LIKE MUCH OF THE I-70 TAF SITES...COU AND STL
METRO...WILL BE ON THE NORTHERN EDGE OF THIS RAIN THRU MUCH OF
WEDNESDAY. HAVE MAINTAINED A RAINY FORECAST WITH MINIMAL
RESTRICTIONS, BUT A SLIGHT TURN MORE TO THE SOUTH OF THIS SYSTEM
COULD KEEP THESE AREAS NOW MOSTLY DRY. UIN MAY MISS MUCH OF THIS
SYSTEM OTHER THAN THE OUTFLOW GENERATED SHRA MOVING THEIR WAY
OVER THE NEXT FEW HOURS. STILL LOOKING AT A BREAK MIDDAY INTO
EARLY AFTERNOON WITH NEW DEVELOPMENT 4-5 HOURS LATER HEADING
TOWARDS EARLY EVENING. LIGHT EASTERLY FLOW EXPECTED FOR MUCH OF
THE VALID PERIOD. VFR CONDITIONS WILL GIVE WAY TO MVFR AT MOST
SITES LATE TONIGHT AND WEDNESDAY.

SPECIFICS FOR KSTL: SHOULD BE QUIET AND VFR UNTIL LATE TONIGHT
WHEN THE NEXT ROUND OF RAIN WITH PERHAPS SOME TSRA MOVES IN. A
THIS WILL PROBABLY CONTINUE UNTIL MIDDAY WHEN IT EXITS AND A NEW,
INITIALLY MORE SCATTERED, ROUND DEVELOPS LATE AFTERNOON AND
CONTINUES INTO THE EVENING. LIGHT EASTERLY FLOW THRU THE PERIOD
WITH MVFR CIGS PREVAILING MORE ON WEDNESDAY.

TES

&&

.PRELIMINARY POINT TEMPS/POPS:
SAINT LOUIS     81  71  84  71 /  80  70  10  10
QUINCY          80  66  82  67 /  50  30  10  20
COLUMBIA        79  69  84  70 /  80  60  10  30
JEFFERSON CITY  79  69  84  71 /  90  70  10  40
SALEM           81  71  82  67 /  80  80  30  10
FARMINGTON      78  69  83  68 /  90  90  20  20

&&

.LSX WATCHES/WARNINGS/ADVISORIES:
MO...FLASH FLOOD WATCH FROM 7 AM CDT THIS MORNING THROUGH LATE
     TONIGHT FOR COLE MO-CRAWFORD MO-FRANKLIN MO-GASCONADE MO-
     IRON MO-JEFFERSON MO-MADISON MO-MONITEAU MO-OSAGE MO-
     REYNOLDS MO-ST. FRANCOIS MO-STE. GENEVIEVE MO-WASHINGTON MO.

IL...FLASH FLOOD WATCH FROM 7 AM CDT THIS MORNING THROUGH LATE
     TONIGHT FOR MONROE IL-RANDOLPH IL-ST. CLAIR IL-WASHINGTON
     IL.

&&

$$

WFO LSX


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