[LeArc] Forecast Discussion : MLI@ 5/26/2003 3:07:22 AM

[learc@mailman.qth.net]

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


FXUS63 KDVN 260805
AFDMLI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
305 AM CDT MON MAY 26 2003

QUIET WX ACROSS THE CWA THIS MORNING...WITH LITTLE IN THE WAY OF 
CLOUDS...THE SURFACE RIDGE JUST TO THE WEST OVER WESTERN IA...AND 
LIGHT NORTHERLY FLOW.  UPPER LEVELS SHOW THAT THE MAIN UPPER LEVEL 
LOW CENTER HAS DRAWN OFF TO THE EAST IN THE LAST 24 HOURS...AND NOW 
A WEAK TROUGH AND VORT MAX OVER MN WILL SWEEP ACROSS IA IN THE NEXT 
12 HOURS.  SOME AC ASSOCIATED WITH THIS TROUGH AND VORT MAX...AND 
THIS IS EXPECTED TO AFFECT CWA THIS MORNING.  

MAIN QUESTIONS THIS FORECAST INCLUDE TEMPS AND CLOUDS NEXT 4 
PERIODS...AND TIMING OF PRECIP MOVING IN FOR WEDNESDAY. 

00Z MODELS APPEAR TO HAVE INITIALIZED REASONABLY WELL...THOUGH SOME 
TIMING AND STRENGTH DIFFERENCES FOR THE SURFACE FRONT DUE THROUGH ON 
WEDNESDAY.  ETA IS A SLOWER SOLUTION...AND THE UPPER LEVEL FEATURES 
ARE FARTHER NORTH AND THE SYSTEM IS MORE COMPACT...WITH A WEAKER 
FEATURE TO CROSS THE CWA A LITTLE LATER THAN ON THE AVN SOLUTION.  
AVN SOLUTION HAS A SLIGHTLY STRONGER FEATURE MOVING THROUGH...AND 
BRINGS MORE MOISTURE NORTH INTO IA AHEAD OF FRONT.  AVN MOISTURE MAY 
BE OVERDONE...BUT OTHERWISE SOLUTION SEEMS REASONABLE. ETA NOT 
UNREASONABLE EITHER...SO WILL BE GOING WITH A BLEND SOMEWHAT.

TODAY SOME AC LINGERING OVER THE AREA IN WAKE OF 500MB SHORTWAVE 
PASSAGE...THOUGH DON'T EXPECT MUCH ACTUAL COVERAGE...AND 
MOSUNNY/PCLDY OUGHT TO DO IT.  TEMPS SHOULD BE CLOSE TO YESTERDAYS 
HIGHS...WITH FAIRLY NEUTRAL 850 T ADVECTION...AND COOLER TEMPS 
ADVECTING IN AT THE SURFACE FROM THE NORTHEAST TO OFFSET FULL SUN.  

TONIGHT OUGHT TO BE COMPLETELY CLEAR...WITH SURFACE RIDGE STILL TO 
WEST AND NORTHEAST SURFACE FLOW.  TEMPS TO FALL TO SIMILAR VALUES TO 
LOWS EXPECTED FOR THIS MORNING...THOUGH WONT GO QUITE AS COOL ACROSS 
THE NORTH.  

TUESDAY AND TUESDAY NIGHT REMAIN QUIET WITH SURFACE RIDGE FINALLY 
SHIFTING OVER AND TO THE EAST OF THE AREA...AHEAD OF THE WEDNESDAY 
SYSTEM.  HAVE GONE WITH GRADUALLY INCREASING CLOUDS...THOUGH STILL 
ONLY PARTLY CLOUDY AT MOST.  TEMPS WARMING VERY SLOWLY...THOUGH 
TUESDAY NOT SIGNIFICANTLY WARMER THAN TODAY.  

BY WEDNESDAY FRONT TO MOVE THROUGH AREA...AND HAVE GONE WITH BLANKET 
CHANCE POPS.  MAY EVENTUALLY GO WITH LIKELIES...THOUGH ALL DEPENDS 
ON THE SURFACE MOISTURE RETURN AND THE DEVELOPMENT OF THE UPPER 
LEVEL SHORTWAVE.  TEMPS WARM SIGNIFICANTLY AHEAD OF SURFACE FRONT 
AND HAVE GONE ABOVE GUIDANCE ALL LOCATIONS.  

.EXTENDED (THU-SUN)...NO REASON TO CHANGE GOING FORECAST...WITH A 
FRONT DUE THROUGH IN THE LATE FRIDAY TIME FRAME.  NEW GFS RUN THAT 
JUST CAME IN LEANING TOWARDS A DRY SATURDAY...BUT WILL LET DAY SHIFT 
RE-EVALUATE AS COMPARED TO NEW EUROPEAN RUNS.  THEY WERE QUITE 
DIFFERENT FROM GFS YESTERDAY...AND SHOULD WATCH TRENDS.    

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

$$

LE