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000
FXUS63 KLSX 141418
AFDLSX

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE ST LOUIS MO
918 AM CDT FRI JUN 14 2013

.UPDATE...
ISSUED AT 912 AM CDT FRI JUN 14 2013

QUICK UPDATE TO THE GRIDS THIS MORNING TO ADD SOME
ISOLATED/SCATTERED SHOWERS AND THUNDERSTORMS FOR NORTHEAST
MISSOURI COUNTIES. SCHROEDER RULE IN EFFECT WITH +18C 850MB
DEWPOINT @KTOP THIS MORNING...OWING TO STOUT MOISTURE CONVERGENCE
ACROSS WESTERN IOWA AND NORTHWEST MISSOURI. BELIEVE THIS ACTIVITY
WILL SLOWLY EDGE EAST THROUGH THE LATE MORNING AND INTO THE
AFTERNOON...AFFECTING MAINLY THE NORTHERN SECTIONS OF THE CWA.

CVKING

&&

.SHORT TERM...(THROUGH LATE THIS AFTERNOON)
ISSUED AT 333 AM CDT FRI JUN 14 2013

CONVECTION DEVELOPING ACROSS NEBRASKA AND WRN IOWA EARLY THIS MRNG.
ALTHOUGH THIS CONVECTION SHOULD WEAKEN LATER THIS MRNG AS IT
ENCOUNTERS A MORE STABLE ENVIRONMENT AND LESS FAVORABLE LOW LEVEL
MOISTURE FURTHER E NEAR A SFC RIDGE EXTENDING FROM THE GREAT LAKES
REGION S-SW INTO ERN MO AND IL...MORE CONVECTION WILL LIKELY DEVELOP
THIS AFTN AHEAD OF WEAK SHORTWAVES AND ANY MCVS OVERTOPPING
MID-UPPER LEVEL RIDGE CENTERED OVER THE SRN PLAINS.  THIS CONVECTION
WILL MOVE E-SEWD INTO NERN MO AS DEPICTED BY THE OPERATIONAL MODELS
AND THE 4 KM NCEP WRF.  WILL HAVE MAINLY HIGH LEVEL CONVECTIVE
DEBRIS CLOUDS TODAY ALONG WITH A FEW DIURNAL CUMULUS CLOUDS LATE
THIS MRNG AND AFTN.  HIGH TEMPERATURES TODAY SHOULD BE SIMILAR TO
YESTERDAY AND CLOSE TO SEASONAL NORMALS WITH THE WARMEST READINGS
ACROSS CNTRL AND SERN MO AS THE SFC/LOW LEVEL WINDS BECOME SELY/SLY
AS THE SFC/850 MB RIDGE BEGINS TO SHIFT E-SE OF THIS AREA AND THE
WARMER 850 MB TEMPERATURES ADVECT EWD INTO THIS REGION.

GKS

.LONG TERM...(TONIGHT THROUGH THURSDAY)
ISSUED AT 333 AM CDT FRI JUN 14 2013

(TONIGHT - MONDAY)

ACTIVE WX WITH PLENTY OF OPPORTUNITIES FOR RAIN WILL DOMINATE THIS
PERIOD.

UPPER LEVEL RIDGE JUST TO THE SW OF THE FA IS EXPECTED TO STEER AN
OLD MCV FROM CONVECTION OVER THE CNTRL HI PLAINS THRU SWRN IL
TONIGHT BUT WILL LARGELY ACT UPON A FAIRLY STABLE AIRMASS.  NONE OF
THE MODELS WANT TO PUSH MUCH PCPN...IF ANYTHING...THRU THE FA AS A
RESULT...BUT AM SUSPECT OF THIS.  MOISTURE SHOULD BE SUFFICIENT...
AND WITH A LOCALLY STRONG SOURCE OF LIFT IN THE OLD MCV...BELIEVE
THE MODELS ARE UNDERDONE IN PCPN POTENTIAL FROM THIS FEATURE...AND
HAVE CONTINUED IN LARGE PART THE POP TRENDS DESPITE A LOWERING IN
MOS VALUES.

UPPER LEVEL RIDGE WILL THEN GET FLATTENED FROM LATE SATURDAY THRU
SUNDAY BY PASSAGE OF A STORM SYSTEM CURRENTLY LOCATED OVER SWRN TX.
THIS SYSTEM WILL BE ACCOMPANIED BY RICH MOISTURE AND WITH DECENT
UPPER LEVEL SUPPORT ANTICIPATED FURTHER ENHANCED BY THE PRESENCE OF
A SFC FRONT ACROSS THE NRN FA...SHOULD SEE HI-END CHC AND LIKELY
POPS FOR MOST LOCALES...PREFERRING AT OR ABOVE THE HIGHEST MOS.
ADDITIONAL UPPER LEVEL DISTURBANCES WILL CONTINUE TO STREAM THRU
LATER SUNDAY AND SUNDAY NIGHT...PROVIDING CONTINUED CHCS FOR TSRA.
ALL OF THIS WILL CULMINATE ON MONDAY WITH A SFC CDFNT SWEEPING THRU.

WITH ALL OF THESE RAIN CHCS...ANY HOT TEMPS WILL BE KEPT AT BAY.
SATURDAY IS THEIR ONE DECENT OPPORTUNITY AT ABOVE AVERAGE TEMPS WITH
AN UPPER LEVEL RIDGE OF DECENT STRENGTH STILL IN THE VICINITY AND
RAIN PROBABLY HOLDING OFF UNTIL LATE.  MOS TEMPS ON SUNDAY LOOK TOO
WARM AND UNDERCUT.

(TUESDAY - THURSDAY)

A RELATIVELY DRY PERIOD THANKS TO PASSAGE OF THE CDFNT ON MONDAY
ALLOWING SFC HI PRES TO PREVAIL.

WENT DRY POPS FOR TUESDAY THRU WEDNESDAY...BUT DID SLIP IN SOME LO
POPS AGAIN BY THURSDAY WITH MOISTURE RETURN AND A SFC WRMFNT IN THE
AREA.

WHILE THE UPPER LEVEL RIDGE LOOKS LIKE IT IS TRYING TO RE-ASSERT
ITSELF OVER THE HI PLAINS...ANOTHER STRONG PAC NW SYSTEM CRASHES
ONSHORE AND LIMITS ITS AMPLIFICATION...AND SO THE FINAL LEADUP TO
THE SUMMER SOLSTICE...IT IS LOOKING LIKE OUR AREA WILL AVOID ANY BIG
HEAT WAVES.

TES

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 516 AM CDT FRI JUN 14 2013

HIGH LEVEL CONVECTIVE DEBRIS CLOUDINESS WILL DROP SEWD INTO THE
TAF SITES TODAY AND TGT. MAY ALSO HAVE FEW DIURNAL CUMULUS CLOUDS
LATE THIS MRNG AND AFTN. MOST OF THE CONVECTION WILL REMAIN N-NW
OF THE TAF SITES TODAY AND TGT...ALTHOUGH SHOWERS/STORMS MAY
IMPACT UIN MAINLY LATE TGT. SFC RIDGE EXTENDING FROM WI S-SW
THROUGH MO WILL SHIFT E-SEWD. LIGHT SFC WIND WILL BECOME SELY IN
UIN AND COU AND ELY IN THE ST LOUIS METRO AREA LATE THIS MRNG AND
INCREASE TO 7-8 KTS LATE THIS MRNG OR AFTN.

SPECIFICS FOR KSTL...HIGH LEVEL CLOUDS THIS FORECAST PERIOD ALONG
WITH A FEW DIURNAL CUMULUS CLOUDS LATE THIS MRNG AND AFTN. COULD
NOT RULE OUT ISOLATED SHOWERS OR STORMS SAT MRNG BUT WILL LEAVE
THE STL TAF DRY FOR NOW. LIGHT SFC WIND WILL BECOME ELY AND
INCREASE TO 7-8 KTS THIS AFTN. THE SFC WIND WILL VEER AROUND TO A
SELY DIRECTION THIS EVNG...AND THEN TO A SLY DIRECTION SAT MRNG.

GKS

&&

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

$$

WFO LSX