[LeArc] Forecast Discussion : MLI@ 8/24/02 1:59:29 AM

[learc@mailman.qth.net]

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


FXUS63 KDVN 240703
AFDMLI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
200 AM CDT SAT AUG 24 2002

.OVERVIEW...QUIET PERIOD UNDERWAY AS WEAK SURFACE HIGH MOVES IN FROM
NORTHERN PLAINS.  ALOFT...WEAK ZONAL FLOW WITH NO COHERENT FORCING OR
TRIGGER SUPPORTING TYPICAL LATE SUMMER CONDITIONS.  LATE NIGHT AND
EARLY MORNING FOG BIGGEST ISSUE PER 06Z OBS UPSTREAM IN MN/WI WITH
LOTS OF 1/2 MILE VIS ALREADY AND NEARLY CALM WINDS.  WEAK FLOW AND
LOTS OF SURFACE MOISTURE FROM RECENT RAINS SUPPORT GOOD CHANCE OF
LOCALLY DENSE CONDITIONS...NEXT COUPLE OF MORNINGS.

...TEMPS AND FOG CHANCES MAIN FORECAST ISSUE...

.DIAGNOSIS AND DAYS 1-3...MODELS SIMILAR IN HANDLING QUIET PATTERN WITH
SOME PROBLEMS WITH HIGH PLAINS CONVECTION SUPPORTING MORE HIGH CLOUDS
TODAY.  ALSO...SHOULD SEE SOME FAIR WEATHER CUMULUS BY 11 AM AS WELL
AFTER LEFTOVER EARLY MORNING FOG WHICH WILL NOWCAST NEXT FEW HOURS TO
SEE IF DENSE FOG ADVISORY NEEDED...HOPEFULLY CURRENT CLOUDS WILL LIMIT
WIDESPREAD DENSE FOG FORMATION TOWARD SUNRISE.   AS STATED ABOVE...NEAR
IDEAL CONDITIONS FOR DENSE FOG SUN/MON MORNINGS...BASED ON LOCAL STUDIES
AND FITS WITH CLIMATOLOGICAL AUGUST SECOND MAX...PASS TO DAY SHIFT AS
EXPECT DENSE FOG ADVISORIES WILL BE NEEDED NEXT COUPLE OF DAYS TIL ~9 AM
OR POSSIBLY EVEN A LITTLE LATER.  IN ADDITION...WOULD BE SURPRISED IF A
DENSE FOG ADVISORY ISN/T NEEDED BY MIDNIGHT FOR PORTIONS OF FORECAST
AREA TONIGHT AND SUNDAY NIGHT.  TEMPS...WILL FOLLOW CLOSE TO MET/MAV/FWC
BLEND WHICH ARE ALL CLOSE AND GO ON LOW SIDE FOR LOWS WITH IDEAL
CONDITIONS FOR FOG (I.E. RADIATIVE COOLING).  MONDAY...AREA REMAINS
BETWEEN SYSTEMS WITH CLOSED LOW TO OVER SE US SO WITH WEAK RIDGE STILL
IN PLACE LIMIT QPF CHANCES.

.EXTENDED (TUE-FRI)...UKMET SUPPORTS CHANCE POPS LATE WED INTO THU WITH
NEXT SYSTEM THO FORCING MARGINAL.  PLAN TO LOOK AT MRF BEFORE ISSUANCE
BUT SEE LITTLE OR CHANGES NEEDED SINCE POPS ALREADY IN.

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

NICHOLS