[LeArc] Forecast Discussion : MLI@ 5/25/02 2:52:22 PM

[learc@mailman.qth.net]

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


FXUS63 KDVN 251952
AFDMLI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
250 PM CDT SAT MAY 25 2002

WOULD EXPECT CELLULAR CU FIELD WEST OF THE MS RIVER TO DISSIPATE
AFTER SUNSET...BUT MAY HAVE TO WALK OUT STRATUCU ACRS THE EAST OR USE
GENERAL DECREASING CLOUDS WORDING. SUBSIDENCE SEEN ON W/V IMAGERY
SHOULD CONTINUE TO HAVE ITS CLEAR OUT EFFECT...BUT AGAIN PROCESS
GOING SLOWER THAN EARLIER EXPECTED OR MODEL INDICATED. AS CENTRAL
PLAINS SFC RIDGE BUILD ACRS THE AREA TONIGHT...EXPECT LIGHT WINDS AND
CLEARING SKIES TO SET STAGE FOR ANOTHER COOL NIGHT. WILL LEAN TOWARD
COOLER MAV LOWS LOOKING AT INCOMING AIRMASS AND SFC DPTS...AND MAY
EVEN UNDERCUT THESE NUMBERS A CATEGORY. LIGHT CONVERGENCE ON EAST
SIDE OF RIDGE TOWARD MORNING AND TEMPS APPROACHING DPTS...MAY CREATE
SOME FOG UTILIZING RECENT SFC MOISTURE...ESPECIALLY ALONG AND EAST OF
MS RVR. WILL BANK ON IT NOT BEING WIDESPREAD ENOUGH FOR ZONE MENTION.

VORT ENERGY WILL SHEAR DOWN ACRS THE NORTHERN PLAINS AND MN/WI LATE
SUNDAY AND SUNDAY NIGHT...AS NORTHERN STREAM BECOMES DOMINANT STORM
TRACK. THESE WAVE COMPLEXES WILL INTERACT WITH NEXT UPSTREAM BOUNDARY
FOR CONVECTION TO NORTH OF CWA TOMORROW...BUT EXPECT SFC RIDGE TO
KEEP THINGS ACRS THE LOCAL CWA MUCH AS WHAT'S GOING ON OUT IN NE THIS
AFTERNOON...SUNNY/MOSTLY SUNNY. FEEL DEVELOPING CU FIELD ACRS
NORTHERN 2/3'S OF CWA SUNDAY NOT ENOUGH TO RUIN MOSTLY SUNNY
WORDING...BUT A FEW AREAS NORTH OF I-80 MAY BE PARTLY CLOUDY FOR
PORTIONS OF THE AFTERNOON. BACKING H85 FLOW TO WAA ACRS THE AREA
TONIGHT AND CONTINUE INTO SUNDAY...WITH H85 TEMPS RECOVERING TO +12
TO +13 C LEVELS BY 00Z MON. DECENT MIXING AND INSOLATION WOULD MAKE
FOR UPPER 70S OR AN 80 DEGREE HIGH...BUT AFTER COOL START AND MOIST
GROUND TO OVERCOME...MAY FALL BACK TO COOLER MAV HIGHS.

AS BOUNDARY TO NORTH AND THTA-E CONVERGENCE ALONG IT SAGS SOUTH
TOWARD CWA...CONVECTION CHANCES SHOULD MIGRATE WITH IT. CHANCES LOOK
LATE THOUGH TOWARD MONDAY MORNING...AND MAY LIMIT TO NORTHWEST CORNER
OF CWA. BOUNDARY WILL CONTINUE TO DROP ACRS THE CWA AND WASH OUT ON
MEMORIAL DAY...BUT SHORT RANGE MODELS HINT THAT THE WESTERLIES
ALOFT WILL USHER A WEAK VORT ACRS THE AREA. FCST SOUNDINGS...
ESPECIALLY ETA...PAINT UNSTABLE PICTURE FOR MONDAY AFTERNOON AND MAY
BE A SITUATION FOR SCATTERED HIT AND MISS CONVECTION TO PLAGUE PARTS
OF THE CWA. ALTHOUGH ETA MAY BE A BIT OVERZEALOUS ON INSTABILITY
PARAMETERS AND INCOMING SFC MOISTURE...MAY INCREASE POPS A BIT ON
MONDAY.

.LONGER TERM(TUE-SAT)...WESTERLY STORM TRACK TO SET UP ALONG THE
NORTHERN CONUS NEXT WEEK...AND MEDIUM RANGE MODELS STILL SWEEP WAVE
ALONG ITS SOUTHERLY PERIPHERY AND OVER THE AREA FOR SHOWER/STORM
CHANCE TUE. UPPER ENERGY GETS PINCHED OFF MAIN FLOW AND LINGERS INTO
WED FOR CONTINUING PRECIP CHANCE. BUILDING UPPER RIDGE ACRS MUCH OF
THE WESTERN HALF OF THE CONUS WILL LOOK TO FOLD ACRS THE UPPER
MIDWEST THU AND END OF WEEK. THIS WOULD SUPPORT A DRY AND WARM END TO
THE WEEK AS THE AREA BECOMES UNDER THE INFLUENCE OF SOME OF THE
PLAINS THERMAL RIDGE. BUT AMPLIFYING NORTHWEST FLOW ACRS SOUTH
CENTRAL CANADA AND THE NORTHERN GRT LKS...MAY COME CLOSE TO SPILLING
SOME RIDGE RIDING ACTIVITY AND BACKDOOR COLD FRONTS DOWN ACRS THE
WESTERN LAKES AND INTO THE NORTHERN CWA FRI AND SAT. WILL KEEP THE
THU-SAT PERIOD DRY AND WARM FOR NOW...ALTHOUGH POSSIBLE FRONT
SLIPPING SOUTH DOWN LK MICHIGAN MAY MAKE FOR COOLER SAT. STILL TOO
FAR AWAY FOR MUCH OF A MORE DEFINITIVE LAKE EFFECT SCENARIO TO COOL
TEMPS WELL BELOW GUIDANCE FOR NOW. OTHERWISE...MUCH MORE OF A LATE
SPRING-LIKE WEEK WITH HIGHS IN UPPER 70S TO LOWER 80S. WILL GO ABOVE
GUIDANCE ON THU.


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

JDH