[LeArc] Forecast Discussion : MLI@ 8/26/02 2:35:38 AM

[learc@mailman.qth.net]

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


FXUS63 KDVN 260740
AFDMLI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
240 AM CDT MON AUG 26 2002

THINNER CI OVER CWA THIS MORNING THAN PAST COUPLE MORNINGS...AND 
WITH GROUND MOISTURE FROM SCATTERED SHOWERS SUNDAY...SHOULD LEAD TO 
MORE WIDESPREAD FOG. WILL MONITOR TRENDS UP TO FORECAST 
ISSUANCE...BUT DO NOT ANTICIPATE NEED FOR ADVISORY AT THIS TIME. 
OTHERWISE...CHALLENGE TODAY IS POTENTIAL FOR MORE AFTERNOON 
SHOWERS...THEN JUST TEMPERATURES THROUGH DAY 3. 

RATHER STAGNANT PATTERN CONTINUES WITH LITTLE SURFACE PRESSURE 
GRADIENT AND WEAK FLOW ALOFT. AT 00Z H5 RIDGE AXIS EXTENDED FROM 
DESERT SW TO NORTHERN PLAINS WITH WEAK CIRCULATION OVER MT AND WEAK 
TROUGH EXTENDING FROM EASTERN CANADA TO OHIO VALLEY. THIS WAS 
RESULTING IN WEAK MID AND UPPER LEVEL DIVERGENCE OVER FORECAST AREA 
THAT WILL CONTINUE TODAY. GUIDANCE IN AGREEMENT WITH PATTERN 
EVOLVING INTO PSUEDO OMEGA BLOCK TOWARD MID WEAK WITH LOWS DEEPENING 
WEST OF DIVIDE AND OVER THE SE. THIS WILL PERMIT PERSISTANCE TYPE 
FORECAST WITH ONLY CHANGE BEING ELIMINATION OF INTITIAL SLIGHT 
CHANCE POPS BY MIDWEEK AS AIRMASS DRIES SOME AND UPPER LEVEL RIDGE 
BUILDS OVER AREA.

FORECAST SOUNDINGS SHOW LESS INSTABILITY OVER AREA TODAY THAN SUNDAY 
WITH SLIGHTLY LOWER MID LEVEL LAPSE RATES. HOWEVER...STILL HAVE WEAK 
UPPER DIVERGENCE AND WITH WEAK H85 CONVERGENCE AND PROXIMITY OF H5 
TROUGH TO SE WILL INTRODUCE SLIGHT CHANCE POPS FOR SOUTHERN HALF 
WHERE MOS HAS NEAR 20 PERCENT. SLIGHTLY COOLER H85 TEMPERATURES 
PROGGED...BUT WITH LESS CI SHOULD SEE SIMILAR HIGHS TO SUNDAY AND 
STAYED CLOSE TO GUIDANCE. WILL KEEP MENTION OF PATCHY FOG GOING FOR 
TONIGHT. NO BIG CHANGES TO TUESDAY THROUGH WEDNESDAY WITH SIMILAR 
TEMPERATURES. WILL REMOVE POPS FROM WEDNEDSAY NIGHT AS LATEST 
GUIDANCE BACKS OFF ON SHORTWAVE TOPPPING RIDGE.     
 
IN EXTENDED...NO BIG CHANGES ANTICIPATED TO ON-GOING AS UPPER RIDGE 
FLATTENS AND TROUGH PUSHES THROUGH SATURDAY NIGHT THROUGH EARLY 
SUNDAY. WILL KEEP CURRENT MENTION OF SHOWERS AND THUNDERSTORMS 
THURSDAY AND AGAIN SUNDAY. 

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

DLS