000
FXUS63 KLSX 062325
AFDLSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE ST LOUIS MO
625 PM CDT SAT SEP 6 2008
.DISCUSSION...
/233 PM CDT SAT SEP 6 2008/
MAIN CONCERN THE NEXT FEW DAYS IS PRECIPITATION CHANCES. NAM/GFS
MASS FIELDS ARE IN DECENT AGREEMENT UNTIL LATE MONDAY WHEN THE GFS
BECOMES MORE PROGRESSIVE THAN THE NAM WITH THE TROUGH THAT DIGS
OUT OF CANADA. WENT CLOSER THE GFS WHICH IS SUPPORTED BY THE OTHER
GLOBAL MODELS.
HAVE GONE WITH CHANCES OF SHRA OVER THE NWRN HALF OF THE CWA THIS
EVENING AND SPREAD THE CHANCE AREAWIDE OVERNIGHT WITH LIKELY POPS IN
THE NORTH AS CNTRL PLAINS SHORTWAVE MOVES EWD TONIGHT. WHILE THERE
WILL BE SOME SUBSIDENCE TOMORROW ONCE THE SHORTWAVES PASSES TO THE
EAST...GFS IS SHOWING SOME MODEST LOW LEVEL FORCING SETTING UP
ACROSS THE OZARKS...SO HAVE KEPT CHC OF SHRA. ONLY WEAK INSTABILITY
WILL EXIST...SO HAVE JUST SLGT CHC OF TSRA. BETTER CHANCES WILL
COME SUNDAY NIGHT AS THE WESTERN HALF OF THE CWA WILL BE ON THE
ERN PERIPHERY OF BROAD 40 KT LOW LEVEL JET. HAVE KEPT MENTION OF
TSRA GIVEN THE GFS MUCAPES OF 400-800 J/KG. GFS HAS MLCAPES
INCREASING INTO THE 1000-1500 J/KG RANGE ON MONDAY AHEAD OF DECENT
SHORTWAVE TROUGH AND IT`S ACCOMPANYING COLD FRONT. DO NOT BELIEVE THAT
NRN HALF OF THE CWA WILL GET WARM ENOUGH TO REALIZE THE NEARLY
2000 J/KG MLCAPES THE THE GFS HAS DEPICTED BECAUSE OF EXPECTED
RAINFALL. HAVE LIKELY POPS GOING OVER THE NRN HALF OF THE CWA
MONDAY/MONDAY NIGHT WITH JUST CHANCE POPS ELSEWHERE. DEEP LAYER
SHEAR ON MONDAY WILL BE IN THE 30-40KT RANGE BY LATE MONDAY
INDICATING THE POTENTIAL FOR SOME STRONG STORMS IF AFOREMENTIONED
INSTABILITY CAN BE REALIZED.
WENT A BIT WARMER THAN GUIDANCE TONIGHT BASED ON CURRENT DEWPOINTS
AND EXPECTED CLOUD COVER OVERNIGHT. MOS GUIDANCE IS IN GOOD
AGREEMENT AND LOOKS DECENT SUNDAY/SUNDAY NIGHT...GUT DID CUT
GUIDANCE IN THE NORTH ON MONDAY BECAUSE OF EXPECTED CLOUDS/RAIN.
STAYED WITH THE GFS SOLUTION MID AND LATE WEEK AS ECWMF HAS SHOWN
SOME SIGNIFICANT PROBLEMS WITH CONTINUITY SINCE YESTERDAY. HAVE
REFINED PRECIPITATION CHANCES FROM WEDNESDAY NIGHT INTO EARLY FRIDAY
WITH THE PASSAGE OF THE NEXT SHORTWAVE TROUGH/COLD FRONT.
TEMPERATURES ARE BASED ON A COMBINATION OF PERSISTENCE...HPC
GUIDANCE AND THE GFS MEAN MOS.
BRITT
&&
.AVIATION...
/611 PM CDT SAT SEP 6 2008/
FOR THE 00Z TAFS...AREA OF SHRA IS NOT DEVELOPING AS FAR S AS PREV
TAFS INDICATED. LATEST RADAR TRENDS AND MDL GUIDANCE SUGGEST THAT
SHRA SHUD STAY JUST N OF COU. COU MAY STILL SEE SHRA...BUT DO NOT
THINK IT WILL LOWER VISBYS BELOW 6SM OR CIGS BELOW VFR. HAVE MOVED
UP TIMING FOR PRECIP AT UIN. MDLS INDICATE SHRA TO CONTINUE TO
DEVELOP AND SHUD MOVE OVER UIN THRU MUCH OF THE EVE HOURS...BUT
SHUD BE ENDING JUST AFTER MIDNIGHT. STL AND SUS SHUD REMAIN DRY
TONIGHT. HAVE ADDED VCSH TO ACCOUNT FOR SOME LIGHT PRECIP CHANCES.
AGAIN...ANY PRECIP SHUD NOT LOWER VISBYS OR CIGS SIGNIFICANTLY.
CIGS SHUD GRADUALLY LOWER TONIGHT AND REMAIN FOR MUCH OF SUNDAY
MORNING. AROUND 18Z...CIGS SHUD BEGIN TO IMPROVE TO VFR WITH A BKN
MID LAYER REMAINING AS ANOTHER SYSTEM APPROACHES.
TILLY
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
