[LeArc] Forecast Discussion : MLI@ 11/4/02 3:02:54 AM

[learc@mailman.qth.net]

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


FXUS63 KDVN 040911
AFDMLI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
305 AM CST MON NOV 4 2002

POST FRONTAL STRATUS DECK...THAT ISN'T THERE ACCORDING TO THE MODEL
LLVL RH PROGS...PLUNGING NICELY SOUTH-SOUTHEASTWARD ACRS THE
NORTHWEST CWA AND WILL HAVE TO BE DEALT WITH IN FIRST PERIOD FOR MOST
OF THE CWA. WILL TEMPER HIGHS BACK CLOSER TO COOLER MAV...EVEN WITH
EXPECTED CLOUD DECK EROSION BY EARLY AFTERNOON AS UPPER RIDGE AXIS
ARRIVAL AND STRONG NVA HAS ITS EFFECT. WEAK WAVE CURRENTLY DROPPING
QUICKLY SOUTHEAST ACRS SOUTHERN MN IN NORTHWEST FLOW ALOFT...ALSO
WILL HAVE TO PASS BEFORE SKY IMPROVEMENT EXPECTED.

CLEARING TO BE SHORT LIVED AS SOUTHWEST CONUS WAVE ENERGY...NOW
KICKING UP PRECIP ACRS PORTIONS OF GRT BSN...PROPAGATES EAST IN
SOUTHERN STREAM FLOW AND TRIES TO PHASE WITH NORTHERN STREAM BY LATE
TONIGHT. ELEVATED WAA AND ISENTROPIC PROCESSES TO SPREAD HIGH TO MID
DECK FROM THE SOUTHWEST OVER THE CWA TONIGHT...SUPPORTING TEMPS FROM
BOTTOMING OUT. FWC/MAV LOWS ARE IN GOOD AGREEMENT AND LOOK REASONABLE
TAKING THIS INTO ACCOUNT. LEAD VORT "EJECTI" AND 290-295 K ISENTROPIC
SFC ANALYSIS INDICATE LLVLS MAY SATURATE ENOUGH IN INCREASING LIFT
FOR SPRINKLES TO REACH THE SURFACE ACRS THE SOUTHWEST/FAR SOUTHERN
CWA BY LATE TONIGHT. LLVL THERMAL PARAMETERS RULE AGAINST FLURRY
POTENTIAL ACRS THE SOUTH WITH INITIAL PRECIP GENERATION. RATHER GOOD
MODEL AGREEMENT ON PATH AND STRENGTH OF MAIN EJECTING VORT ACRS MO
AND TOWARD NORTHERN IN ON TUES...SUGGEST SOUTHEAST THIRD TO HALF OF
THE CWA IN LINE FOR PRECIP. LOOKING AT EXTENT OF PVA AND INHERENT
UVV'S ADVECTED BY H7-H4 THICKNESS THERMAL WIND ON NORTHWEST FLANK OF
THIS VORT FEATURE ACRS THE CWA...AS WELL AS TRIPLE POINT OFF NORTHERN
STREAM SFC TROUGH PASSING OVER THE SOUTHEAST AREA OF CONCERN...
PROBABLY WARRANT LIKELY POPS FOR TUE. MOISTURE INFLUX AT QUESTION
THOUGH FOR MUCH OF ANY KIND OF AMOUNTS...ESPECIALLY WITH SOUTHERN
STREAM SFC LOW STEALING THE PRECIP SHOW TO THE SOUTH AND EAST OF THE
CWA. FORECAST SOUNDINGS SUGGEST THAT SATURATING LLVLS AND TEMPS
REMAINING ABOVE FREEZING TO ABOVE H9 MB ON TUE...AS WELL AS DEEPENING
SOUTH TO SOUTHWEST FLOW THIS TIME OF YEAR SUGGEST AN ALL LIQUID
EVENT. CLOUDS AND PRECIP MAKE THE COOLER MAV NUMBERS AGAIN THE WAY
TO GO FOR TUE HIGHS.

ANOTHER ROUND OF MID LEVEL CONVERGENT QG FORCING TO SWEEP ACRS THE
CWA AND BLOSSOM OVER IL TUE NIGHT...AS SECONDARY VORT DROPS OUT OF
NORTHERN STREAM INTO LONG WAVE TROUGH BASE JUST TO THE SOUTH OF THE
AREA. WITH MODELS SUGGESTING HIGH LLVL RH POOL TO MAINTAIN OVER THE
REGION UNTIL WED MORNING...MAY BE ENOUGH TO WRING OUT SOME SPRINKLES
OR FLURRIES TO JUST AFTER MIDNIGHT WHEN SUBSIDENCE AND ISENTROPIC
DOWN-GLIDE WIN OUT.

NO CHANGE TO LONGER RANGE(WED ON)...


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

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