[LeArc] Forecast Discussion : MLI@ 7/10/02 2:43:27 AM

[learc@mailman.qth.net]

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


FXUS63 KDVN 100743
AFDMLI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
242 AM CDT WED JUL 10 2002

SYNOPTIC PICTURE THIS MORNING SHOWS STRONG 500H SHORT WAVE DIVING
SOUTHEAST OFF TOP OF WESTERN RIDGE INTO THE DAKOTAS.  AT THE SURFACE A
1015MB LOW IS ALONG NE/KS STATE LINE...WITH INVERTED TROF INTO THE
EASTERN DAKOTAS.  A 100KT JET IS NORTHEAST OF THE GREAT LAKES WITH THE
RIGHT REAR QUAD OVER THE UPPER MIDWEST.  A STRONG LINE OF CONVECTION
IN NORTHWEST IOWA...ASSOCIATED WITH SMALLER SHORT WAVE AHEAD OF MAIN
WAVE...IS SHOWING SIGNS OF DIVING SOUTHEAST.

PRIMARY FORECAST CONCERN THIS PACKAGE IS IN THE SHORT TERM...THE NEXT
24 TO 36 HOURS...WITH THE VIGOROUS SHORT WAVE DIVING INTO CENTRAL
IOWA. MAIN CHALLENGE WILL BE EAST-WEST PRECIP GRADIENT...AS CENTRAL
IOWA IS ON TARGET TO GET HEAVY RAINS...BUT THERE WILL BE A PRETTY SHARP
CUT-OFF SOMEWHERE COMING EAST TO THE MISSISSIPPI RIVER.

THE MODELS INITIALIZED WELL AT 500H AND THE SURFACE. THEY AGREE ON THE
500H LOW ARRIVING OVER SOUTHWEST MINNESOTA BY 00Z THIS EVENING...THEN TO
THE OTM/EOK AREA THURSDAY EVENING...AND TO PIA FRIDAY MORNING.  AT THE
SURFACE...HOWEVER...THERE ARE MAJOR DISAGREEMENTS...WITH ETA AND NGM
HOLDING INVERTED TROF WELL WEST...WHILE AVN BRINGS IT DIRECTLY
OVER/SOUTH OF OUR DVN FORECAST AREA. THERE WILL BE MODERATELY GOOD UPPER
SUPPORT TODAY...VIA 300H DIVERGENCE...AND GOOD 700H VV'S WEST TODAY AND
TONIGHT ACCORDING TO THE ETA...AND ACROSS THE AREA ACCORDING TO THE AVN.
 THE AVN EXTENDS VV'S INTO THURSDAY SOUTH.  THE NGM IS WANDERING AROUND
LEFT FIELD SOMEWHERE...WITH NO CLUE.  ONE WAY OR THE OTHER...MAIN QPF
WILL BE JUST WEST OF THE DVN AREA...TODAY AND TONIGHT...BUT COULD STILL
GET SIGNIFICANT PRECIP IN OUR WESTERN SECTIONS AND A FEW SHOWERS TO THE
MISSISSIPPI RIVER.  DRY AIR...ON A LIGHT EASTERLY BREEZE...AND LACK OF
SUPPORT...WILL KEEP PRECIP OUT OF ILLINOIS COUNTIES...EXCEPT SOUTH.

WILL MAKE AT LEAST THREE NORTH-SOUTH SPLITS IN ZONES TO HANDLE EAST-
WEST GRADIENT IN QPF...WITH LIKELY POP'S WEST.  NUMERICAL
GUIDANCE IS SOMEWHAT CONTRARY...WITH MAV AND MET MUCH HIGHER IN POPS
TODAY AND TONIGHT...WITH MAV HIGH INTO THURSDAY ALSO.  IN TEMPERATURES
THE MAV IS MUCH COOLER THAN THE FWC AND MET.  WILL TEND TOWARDS HIGHER
POPS...ESPECIALLY WEST OF THE MISSISSIPPI AND SOUTH...AND WILL KEEP
POPS SOUTH THROUGH THURSDAY DUE TO PROXIMITY OF 500H LOW.  WILL STAY
CLOSE TO CURRENT TEMPS...WHICH ARE CLOSER TO FWC/MET SCENARIO. LOOKING
FURTHER AHEAD...WILL KEEP DRY FORECAST THRU DAY 7.

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

REA