[LeArc] Forecast Discussion : MLI@ 6/24/2003 3:47:15 PM

[learc@mailman.qth.net]

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


FXUS63 KDVN 242043
AFDMLI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
344 PM CDT SUN JUN 22 2003

LATEST SURFACE ANALYSIS INDICATING THAT DOWNRIGHT SICKENING 
DEWPOINTS OF 75 TO 80 HAVE ADVECTED THEIR WAY INTO THE SOUTHWESTERN 
PORTIONS OF THE CWA...AND TEMPS ARE ALREADY INTO THE LOWER TO MIDDLE 
90S...WITH A FEW SITES AS WARM AS 97.  UPPER LEVEL ANALYSIS 
INDICATING THAT SIGNIFICANT WARMING...THIS TIME THROUGH 
ADVECTION...HAS OCCURRED AT THE MID LEVELS ALSO...WITH A WHOPPER OF 
A CAP OF 22 DEGREES C ABOUT 830MB.  WE ARE GOING TO HAVE TO GET SOME 
SIGNFICANT TRIGGER THROUGH HERE BEFORE CONVECTION IS GOING TO BREAK 
OUT TODAY OR TONIGHT.  THE FRONT IS STILL WELL TO OUR WEST...AND NOT 
DUE THROUGH UNTIL TOMORROW NIGHT.  LOCATIONS OVER WESTERN IA HAVE 
BRONKEN THE CAP THERE...BUT THAT IS NEAR THE FRONT AND THE CAP IS 
WEAKER *SLIGHTLY* THERE.  THE UPPER LEVEL LOW IS STILL OVER THE 
ROCKIES...WITH VERY LITTLE IN THE WAY OF FALLS OVER THE PLAINS TO 
INDICATE THAT IT IS MOVING VERY RAPIDLY.  

12Z MODELS APPEAR TO HAVE INITIALIZED REASONABLY WELL...WITH MOST OF 
THEM GOING A LITTLE OVERBOARD ON THE PRECIP TONIGHT...BUT NOT TOO 
BAD OTHERWISE.  NGM APPEARS TO BE SUFFERING FROM ITS USUAL TOO FAR 
INTO THE COLD AIR BIAS...AND THE AVN HAS SOME BULLSEYES OF QPF 
ACROSS MN.  HAVE...IN GENERAL GONE WITH A BLEND OF THE ETA AND 
AVN...WHICH ARE IN REASONABLY GOOD AGREEMENT.

TONIGHT THE CAP SHOULD KEEP ANY THUNDERSTORMS AND MCS ACTIVITY TO 
THE NORTH OF THE CWA...AND HAVE GONE DRY FOR TONIGHT...THOUGH KEPT A 
10 POP FAR NORTH IN CASE THUNDERSTORMS FROM MN AND WI SNEAK SOUTH 
OVERNIGHT.  

WEDNESDAY THROUGH THURSDAY COULD BE VERY INTERESTING...WITH THE 
FRONT MOVING THROUGH OVERNIGHT WEDNESDAY NIGHT.  WITH THE FRONT 
ACTING AS TRIGGER...WE SHOULD FINALLY GET SOME THUNDERSTORMS...AN 
MAY EVEN GET SOME SEVERE WEATHER...MAINLY IN THE FORM OF HIGH WINDS 
FROM A SQUALL LINE OUT AHEAD OF THE FRONT.  BEHIND THE 
FRONT...COOLER AND DRIER AIR MOVING IN SHOULD KEEP ANY PRECIPITATION 
FROM FORMING...DESPITE THE LITTLE WAVE THAT MOVES ACROSS THE AREA ON 
THURSDAY AND THURSDAY NIGHT.  FRIDAY SHOULD ALSO BE DRY...THOUGH THE 
TIMING OF THE WAVE DUE THROUGH ON SATURDAY WILL NEED TO BE MONITORED 
TO SEE IF IT SPEEDS UP INTO THE FRIDAY NIGHT TIME FRAME.

SATURDAY THROUGH TUESDAY...
MODELS ARE CONTINUING THE TREND OF BRINGING A WEAK LITTLE WAVE 
ACROSS THE REGION ON SATURDAY...WITH MOST OF THE DYNAMICS TO THE 
NORTH.  HOWEVER... THIS LOOKS MUCH BETTER THAN IT DID 
YESTERDAY...AND NOW WITH A LITTLE BIT OF CONTINUITY THERE IS MORE 
CONFIDENCE IN THIS SOLUTION.  SO...HAVE DECIDED TO ADD IN A LOW 
CHANCE OF TSRA FOR SATURDAY AND SATURDAY NIGHT.  A WEAK RIDGE SHOULD 
KEEP THINGS QUIET FOR SUNDAY AND MONDAY...WITH GRADUALLY WARMING 
TEMPS IN INCREASING SOUTHERLY FLOW.  TUESDAY A DECENT SURFACE LOW 
DEVELOPS OVER SOUTHERN CANADA...AND THE SOUTHERLY FLOW INCREASES 
OVER THE CWA.  THE GFS WANTS TO BRING A WEAK WARM FRONT ACROSS THE 
AREA LATE MONDAY...WHICH SEEMS PLAUSIBLE...BUT HAVE DECIDED TO LEAVE 
DRY FOR NOW AND LATER SHIFTS CAN WATCH TO SEE IF IT DEVELOPS ANY 
DECENT CONTINUITY.

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

$$
LE