[LeArc] Forecast Discussion : MLI@ 4/11/2003 4:33:41 AM

[learc@mailman.qth.net]

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


FXUS63 KDVN 110931
AFDMLI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
420 AM CDT FRI APR 11 2003

BENIGN FORECAST CONTINUES THROUGH THE NEAR TERM/WEEKEND. THUS MAIN
CONCERN IS TEMPS AND POTENTIAL LARGE DIURNAL SWINGS FROM HIGHS TO
LOWS OVER NEXT FEW DAYS.

AREA TO STAY ON LEE SIDE OF RATHER BROAD UPPER RIDGE OVER THE NORTH
CENTRAL CONUS TODAY...EFFECTIVELY SHUNTING ANY KIND OF RIDGE RIDING
WAVES AND JET ENERGY WELL TO THE NORTH AND NORTHEAST OF DVN CWA.
UPPER RIDGE WILL LOOK TO SHARPEN OVER THE NORTHERN PLAINS ON SAT...
ALLOWING MORE OF A NORTHERLY FETCH DOWN ACRS THE WESTERN GRT LKS AND
GLANCING BLOW OF LOW TO MID LEVEL COLD POOL TO EFFECT THE LOCAL
AREA. SHORT RANGE MODELS SUGGEST WEAK VORT WILL DROP DOWN ACRS THE
AREA IN THIS FLOW ON SAT...BUT DO LITTLE IN MOISTURE STARVED
VERTICAL COLUMN. THUS LOOKS LIKE FAIR WX REGIME OVER WEEKEND...
INCLUDING BRIEF COOL DOWN ON SAT.

WEAK SFC BOUNDARY TO SAG ACRS THE CWA FROM THE NORTHWEST TODAY...
WITH THE WIND IN MOST LOCATIONS(EXCEPT THE FAR SOUTHEAST) BECOMING
NORTHWEST-NORTH LATER THIS AFTERNOON. WIND SWITCH AND SOME
SPEED INCREASE WILL ACTUALLY STIR MIXING BEHIND FROPA TO HELP TEMPS
REACH UPPER 60S-LOW 70S OVER MUCH OF THE CWA. WOULDN'T BE SURPRISED
IF SOME LOCATIONS IN THE SOUTH APPROACH THE MID 70S. VEERING FLOW
TO THE NORTH-NORTHEAST AT THE H85 LEVEL TONIGHT TO ALLOW COOL POOL
TO SPILL SOUTH OVER PORTIONS OF THE AREA AS LLVL RIDGE AXIS BUILDS
ACRS THE GRT LKS OUT OF CANUCK LAND. THIS WILL SET THE STAGE FOR
NORTHEAST FLOW/SOME LK MI FETCH EFFECT COOLER DAY ON SAT...ALTHOUGH
MID APRIL INSOLATION WILL BATTLE EFFECTS. SHOULD BE OVER 10 DEGREE
TEMP GRADIENT SAT AFTERNOON FROM NORTHEAST CWA...TO THE FAR WEST
AND SOUTHWEST.

AGREE WITH PREVIOUS SHIFT OF UNDERCUTTING GUIDANCE FOR SAT NIGHT/SUN
MORNING LOWS...WITH NORTH HALF OF THE CWA DIPPING INTO THE SEASONABLY
COOL REALM OF THE LOW TO MID 30S WITH CONTINUING COOL INFLUX FROM
CENTER OF GRT LKS HIGH. UPPER RIDGE TO TOPPLE OVER THE AREA ON
SUNDAY...AND WITH LOWER LEVEL FLOW BECOMING WEST-SOUTHWEST AND
STARTING THE "TAP INTO WARMER THERMAL POOL OVER THE PLAINS" PROCESS
FOR SUNDAY TEMP REBOUND. ALL IN ALL NOT MUCH CHANGE TO ONGOING
PACKAGE.

NO CHANGE TO LONGER RANGE.

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

$$

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