[LeArc] Forecast Discussion : MLI@ 9/9/02 2:30:07 PM

[learc@mailman.qth.net]

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


FXUS63 KDVN 091936
AFDMLI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
230 PM CDT MON SEP 9 2002

WITH CIN'S CONTINUING TO DECREASE AND LI'S INCREASING OVER THE CWA
THIS AFTERNOON...AREAS OF SOME MOISTURE CONVERGENCE OR OTHER SLIGHT
PERTURBATIONS MAY BECOME BREEDING GROUNDS FOR ISOLATED CONVECTION
LATE THIS AFTERNOON AND EVENING. LOOKING AT CURRENT MSAS PRESSURE
FALLS AND MOISTURE CONVERGENT REGIONS...FAR WEST AND EAST FRINGES OF
CWA MAY BE MORE AT RISK OF THIS ACTIVITY...BUT PROBABLY CAN'T RULE
OUT REST OF CWA AS IMMUNE. WILL WATCH LOCAL RADAR AND SATELLITE
TOWARD ISSUANCE TIME FOR THROW-IN MENTION.

OTHERWISE...OVERNIGHT PERIOD TO BE MOSTLY CLEAR AND MILD AS UPSTREAM
FRONT APPEARS TO BE EVEN SLOWER IN MAKING IT TO THE CWA. AT LEAST
SHORT RANGE MODELS CLOSE ON EVENTUAL FROPA ACRS MS RVR AROUND 15Z-16Z
TIME PERIOD. MODELS CONTINUE WITH POST-FRONTAL PRECIP RIBBON...WITH
SOUTHERN CWA EXPERIENCING LITTLE TO NO ACTIVITY AT ALL. BUT...FEEL
THAT LLVL CONVERGENCE INTO FRONT AND SOME DIFFLUENT SUPPORT OVER EAST
IA FROM RIDGE-RIDING 80-90+ KT JET MAX OVER SOUTHERN MN...MAY MAKE
MORE OUT OF THE SITUATION THAN THE MODELS WANT TO. LOOKING AT
UPSTREAM ACTIVITY OVER NE THIS AFTERNOON AS WELL...EASY TO TRANSLATE
THAT TO OVER EASTERN IA BY EARLY TUE AFTERNOON. MAINLY SHOWERS WITH
SOME EMBEDDED THUNDER...MUCH LIKE ONGOING FORECAST ALREADY
ADVERTISING. BEST SUPPORT AND DYNAMICS...AS WELL AS INHERENT LARGER
PRECIPITATION AREAL COVERAGE SHOULD OCCUR OVER MN TONIGHT AND WI
TOMORROW. WILL UP TUE POPS TO 40 ACRS NORTH AND CENTRAL CWA. INITIAL
CLOUD COVER TUE MORNING WILL BE HIGH TO MID LEVEL BASED...AND WITH
MILD START TO THE DAY...FEEL TEMPS COULD RECOVER TO AROUND 80/LOWER
80S BY MIDDAY BEFORE PRECIPITATION AND BETTER FROPA EFFECT KNOCKS
THEM DOWN AGAIN IN THE AFTERNOON.

CLEARING SKIES AND COOL INFLUX TO ACCOMPANY LARGE IN-BUILDING HIGH
TUE NIGHT. AVN AND ETA VARY SOMEWHAT ON STRENGTH OF NORTHEAST SFC
FETCH OFF LAKE MI ON WED WHICH COULD AFFECT HIGH TEMPS. FOR NOW WILL
GO LOW 70S NORTHEAST CWA...TO MID/UPPER 70S ACRS THE SOUTHWEST.

.LONGER RANGE(THU-MON)...SOUTHERN GRT LKS SFC RIDGE TO MAINTAIN FAIR
AND PLEASANT WX ACRS THE LOCAL CWA INTO EARLY FRI...BEFORE BIG
CHANGES START TO TAKE SHAPE. MEDIUM RANGE MODELS WITH LATEST RUNS...
STARTING TO REALIZE STRENGTH OF DIGGING JET ENERGY PUNCH OVER THE
NORTH-CENTRAL CONUS BY WEEKS END. MOST ARE NOW MORE AMPLIFIED WITH
DIGGING TROUGH OVER THE NORTHERN PLAINS LATE FRI INTO SAT....AND ARE
FASTER TO WHIRL STRONG COLD FRONT THROUGH THE LOCAL AREA BY EARLY
SAT. THESE LATEST SOLUTIONS WOULD MEAN BUMPING UP WARMING PRE-FRONTAL
DAY TO FRI...SHOWERS AND STORMS FRI NIGHT INTO SAT MORNING AHEAD OF
FROPA...CRASHING THICKNESSES SAT AFTERNOON AND NIGHT...AND SUNDAY A
COOL DAY WITH HIGHS IN 60S AND POSSIBLY COLD AIR/CYCLONIC FLOW ALOFT
INSTABILITY CU AND SHOWERS ROTATING OVER THE AREA. THIS WOULD DEPEND
ON WHERE NORTHERN GRT LKS VORTEX SETS UP BY LATE WEEKEND...BUT WILL
LEAN TOWARD LATEST EURO/UKMET BLEND. WILL PLAY NEXT MONDAY AS DAY OF
FULL EFFECT OF CANADIAN HIGH WITH MOSTLY SUNNY SKIES AND HIGHS NEAR
70...ALTHOUGH MRF PROPAGATES WEAK TRAILING VORT ACRS THE AREA MONDAY
AFTERNOON AND BREAKS OUT SPURIOUS LIGHT PRECIP IN CENTER OF 1026 SFC
RIDGE.


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

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