[LeArc] Forecast Discussion : MLI@ 7/31/2003 3:30:24 PM

[learc@mailman.qth.net]

The following weather message is provided by McDonough County E.S.D.A.


FXUS63 KDVN 312022
AFDMLI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
320 PM CDT THU JUL 31 2003

18Z SURFACE ANALYSIS HAS WEAK LOW OVER NORTHWEST IA WITH WARM FRONT 
EXTENDING THROUGH SRN MN AND WI AND COLD FRONT TO THE WEST THROUGH SRN
AND WRN SD.  MESO HIGH BEHIND THUNDERSTORM COMPLEX THAT MOVED 
THROUGH SERN NE  SW IA EARLIER TODAY WAS HELPING TO ENHANCE THE 
CONVERGENCE ALONG THE FRONTAL BOUNDARY NEAR THE IA/MN BORDER WITH 
TSRA STEADILY INCREASING IN COVERAGE DURING THE LAST COUPLE OF HOURS.
ISOLD TSRA ALSO DEVELOPING SE IA/NE MO ALONG STRONG DEWPOINT 
GRADIENT. MAIN FEATURE ON THIS MORNINGS UA ANALYSIS WAS STILL THE 
CLOSED H5 LOW JUST N OF KINL.  MODELS REMAIN IN GOOD AGREEMENT ON
MOVING H5 LOW SLOWLY SOUTH INTO CENTRAL WI BY SUNDAY 
MORNING...KEEPING MID MS VALLEY UNDER INFLUENCE OF DEEP CYCLONIC 
FLOW.  MODEL INITIALIZATION THIS MORNING WAS REASONABLE...ALTHOUGH 
THE GFS WAS HANDLING THE SURFACE PRESSURE FIELDS BETTER THAN THE 
ETA. MODELS HAVE COMPLETELY MISSED THE MCS OVER THE MID MISSOURI 
VALLEY TODAY...WHICH IS HAVING AN ADVERSE EFFECT QPF PROGS SO FAR TO 
OUR SW. THE GFS WILL BE THE FAVORED MODEL FOR THIS ISSUANCE DUE TO 
IT HANDLING OF THE SURFACE FEATURES.  CURRENT FORECAST HAS LIKELY 
POPS FOR OVER NIGHT.  WITH ONGOING TSRA IN THE NORTH WILL KEEP THESE 
POPS NORTH OF HWY 30. BASED ON CURRENT TRENDS IT LOOKS LIKE MAIN 
TSRA COMPLEX TO OUR SOUTH WL REMAIN OVER KS/MO...FOCUSING ALONG 
OUTFLOW LAID OUT BY THIS MORNINGS MCW.  THE SOUTHERN CWA SHOULD ONLY 
SEE SCATTERED CONVECTION LATER THIS EVENING AND OVER NIGHT 
ASSOCIATED WITH SOME WEAK S/W ENERGY PROGGED TO ROTATE THROUGH OVER 
NIGHT.  WILL DROP POPS IN THE SOUTH BACK INTO THE HIGH CHANCE 
CATEGORY.  FRONT IS PROGGED TO MOVE THROUGH  FRIDAY EVENING AND WILL 
CONTINUE CHANCE POPS ASSOCIATED WITH THE FROPA THROUGH FRIDAY EVENING
AND THEN LIMIT POPS TO THE SOUTH DURING THE OVERNIGHT HOURS.  BY 
SATURDAY...CWA SHOULD BE IN A MORE DIURNAL REGIME FOR SHRA/TSRA AS 
THE COOL POOL ASSOCIATED WITH THE H5 LOW COMES INTO PLAY. POPS WILL 
BE LIMITED TO THE AFTERNOON AND EVENING.  GOING TEMP FORECAST LOOKS 
REASONABLE AND HAVE NOT MADE ANY SIGNIFICANT CHANGES. DLF

.LONGER RANGE(SUN-THU)...MEDIUM RANGE MODELS STILL INDICATE WESTERN 
GRT LKS VORTEX AND COLD POOL/STEEP CYCLONIC FLOW ALOFT TO INDUCE 
CLOUDS AND SCTRD SHOWERS/THUNDERSTORMS ON SUN. LOOKING AT THERMAL 
PROFILES AND EXPECTED CLOUDS/PRECIP...TEMPS MAY NOT GET OUT OF THE 
70S OVER MUCH OF THE CWA AND WILL TONE DOWN ONGOING HIGHS FOR SUNDAY.
AS UPPER VORTEX GYRATES SLOWLY EAST ON MONDAY...FEEL STILL FAR 
ENOUGH WEST TO HAVE PRECIP GENERATION INFLUENCES OVER AT LEAST THE 
EASTERN CWA. WILL ALSO TREND MON TEMPS DOWN. MEDIUM RANGE MODELS 
THEN START TO DIVERGE ON EASTWARD EXITING TIMING OF UPPER LOW INTO 
MIDDLE NEXT WEEK...BUT WILL BANK ON FEATURE TO BE FAR ENOUGH EAST 
AND AMPLIFIED UPPER RIDGING EDGING FAR ENOUGH INTO WESTERN IA FOR 
DRY TUE-THU TIME FRAME. LATEST MRF THOUGH...FARTHEST WEST WITH 
VORTEX POSITIONING AND EVEN SUGGESTS SLIGHT RETROGRADE POSSIBLY BY 
WED. LLVL THERMAL MODERATION FROM THE WEST SHOULD MEAN AT LEAST 
LOWER 80S FOR SECOND HALF OF LONGER RANGE.   ..12..


.DVN...
IA...NONE.
IL...NONE.
MO...NONE.

$$