000
FXUS63 KLSX 111137
AFDLSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE ST LOUIS MO
637 AM CDT SAT OCT 11 2008
.DISCUSSION...
/355 AM CDT SAT OCT 11 2008/
MODELS REMAIN IN GOOD AGREEMENT ON MASS FIELDS UNTIL MONDAY BUT
THEN SHOW SOME NOTICEABLE DIFFERENCES THEREAFTER. MODELS CONTINUE
TO SHOW SWLY MID LEVEL FLOW TO DOMINATE OUR REGION UNTIL EARLY
NEXT WEEK...WHEN THE DEEP LO OVER THE CNTRL ROCKIES LIFTS NEWD AND
PASSES THRU THE NRN PLAINS AND UPR MS VALLEY. THIS WILL THEN
RESULT IN A PATTERN SHIFT...WITH A MORE ZONAL FLOW SETTING UP FOR
MUCH OF NEXT WEEK. AT THE SFC...SE TO S FLOW WILL PERSIST UNTIL
MONDAY MAINTAINING THE MUCH ABOVE NORMAL TEMPS. MODELS HAVE
MAINTAINED THEIR SLOWER TREND ON THE FROPA...WHICH MAKES SENSE
CONSIDERING THE SWLY MID LEVEL FLOW UNTIL PASSAGE OF THE STRONG
EJECTING ROCKIES SYSTEM MONDAY NIGHT INTO TUESDAY...WHICH WILL
STEER THE MID LEVEL FLOW WLY ENOUGH TO RESULT IN A MORE REALISTIC
FROPA THRU THE FA DURING THIS TIME. NAM SEEMS TO BE THE OUTLIER
HERE AND HAS A FASTER SEWD FNTL PROPAGATION...AND THIS SOLN HAS
BEEN DISCARDED.
DRY WX IS LARGELY EXPECTED THRU MONDAY AFTERNOON...ALTHOUGH
MOISTURE WILL STEADILY BE ON THE INCREASE...WITH DEWPOINTS
EXPECTED TO EXCEED 60F BY THIS AFTERNOON...AND PWATS NEAR 200PCT
OF NORMAL BY SUNDAY. THIS MAY ALLOW DEVELOPMENT OF AIRMASS TYPE
CONVECTIVE SHRA/TSRA DURING BOTH SUNDAY AND MONDAY AFTN...BUT FOCUS
HARD TO PIN DOWN...AND SOUNDINGS SHOW PRETTY SHALLOW CONVECTION AT
THAT...SHOULD IT FORM.
WITH APPROACH OF CDFNT AND ITS EVENTUAL PASSAGE...HAVE CONFINED
THE RAIN CHANCES TO MONDAY NIGHT THRU WEDNESDAY...ALTHOUGH THERE
IS MODEL DISSENSION ON WHETHER OR NOT TO EJECT THE FINAL PIECE OF
ENERGY FROM THE DEEP TROF CURRENTLY OVER THE WRN CONUS...WHICH
WILL RESULT IN MAINTAIN SOME SORT OF RAIN CHC THRU WEDNESDAY. SLUG
OF TROPICAL MOISTURE FROM NORBERT IN THE ERN PAC LOOKS LIKE IT
WILL BE QUICK TO SURGE NWD...REACHING THE CNTRL PLAINS BY SUNDAY
AND NOT STOPPING THERE...PUSHING FURTHER NEWD AND BCMG ABSORBED
INTO EJECTING STRONG NRN STREAM SYSTEM EARLY NEXT WEEK. MOISTURE
INCREASE OVER THE FA WILL BE SUBSTANTIAL NEVERTHELESS...BUT NOT TO
THE DEGREE THAT THIS TROPICAL MOISTURE WOULD HAVE IT. INSTABILITY
LOOKS DOWNRIGHT MEAGER...WITH BOTH NAM AND GFS SHOWING MUCAPES
STRUGGLING TO EXCEED 100 J/KG AND FREQUENTLY NEAR ZERO...WITH CAPE
AREAS ON SOUNDINGS QUITE SHALLOW. MAINTAINED A MINIMAL THUNDER
SLIGHT CHANCE FOR DAYTIME HOURS OF MONDAY AND TUESDAY.
OTHERWISE...WARM TEMPS WILL BE THE STORY THRU MONDAY. MIXING
HEIGHTS ONCE AGAIN EXPECTED TO BE BTWN H900-H875 THE NEXT FEW
DAYS. WITH LITTLE CLOUD COVER DIFF AND H900 TEMPS RISING BY
1-2C THIS AFTN...LOOK FOR 2-4F HIGHER MAX TEMPS THAN PERSISTENCE.
H900 TEMPS WILL THEN EITHER MAINTAIN THESE LEVELS OR SLIP BY 1C OR
SO...BUT ADDED ITEM WILL BE INCREASED DAYTIME CLOUD COVER...WHICH
SHOULD RESULT IN TEMPS AT OR SLIGHTLY BELOW THEIR EVENTUAL PEAKS
TODAY. EITHER WAY...MAX TEMPS TO BE AROUND 10F ABOVE NORMAL EACH
DAY THRU MONDAY.
TES
&&
.AVIATION...
/632 AM CDT SAT OCT 11 2008/
FOR THE 12Z TAFS...
PRIMARY CONCERN FOR AVIATORS THIS MORNING IS PATCHY IFR/LIFR FOG
IN RIVER VALLEYS. SOME MORE WIDESPREAD MARGINAL VSBYS ACROSS PARTS
OF EASTERN MISSOURI. ALL THIS FOG SHOULD DISSIPATE BETWEEN 13Z AND
14Z THIS MORNING. SCATTERED CU AT 3500-4000FT AND LIGHT SOUTHEAST
FLOW WILL PREVAIL FOR THE REST OF THE DAY.
CARNEY
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
