[LeArc] Forecast Discussion : MLI@ 7/31/02 2:39:01 PM

[learc@mailman.qth.net]

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


FXUS63 KDVN 311941
AFDMLI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
240 PM CDT WED JUL 31 2002

FAIRLY QUIET DAY ACROSS CWA...WITH A TAIL OF CU LEFT OVER FROM EARLY 
MORNING CONVECTION OVER NORTHERN CWA.  LATEST SURFACE ANALYSIS 
INDICATING LOW PRESSURE CENTER OVER SOUTH CENTRAL SD...WITH BEST 
PRESSURE FALLS TO ITS NORTHEAST.  SOUTHERLY FLOW OVER IA FUELING AN 
AREA OF CONVECTION OVER NORTHERN WI.  UPPER AIR CHARTS INDICATING 
GOOD SOUTHWEST 850MB FLOW OVER NEBRASKA...IN GENERAL VICINITY OF 
THERMAL RIDGE...THOUGH BEST MOISTURE STILL A WAYS SOUTH...WITH 
NEAREST 15+ DEWPOINT ON KSGF SOUNDING.  STRONGEST SYSTEM ON CHARTS 
IS OVER B.C./ALBERTA REGION.  GOOD HEIGHT FALLS ACROSS THE NW US... 
WITH A 115KT JET MOVING IN. 

MAIN FORECAST PROBLEM TODAY IS THE CONVECTION EXPECTED AS THE FRONT 
SWEEPS THROUGH THE AREA LATE TOMORROW.  THEN...TEMPS FRIDAY AND 
SATURDAY WITH THE SURFACE RIDGE TO NORTH OF CWA.  

12Z MODELS APPEAR TO HAVE INITIALIZED WELL...AND MODELS BEGINNING TO 
CONVERGE ON A SLOWER FRONT TIMING FOR THURSDAY.  UKMET STILL THE 
SLOWEST OF THE MODELS...THOUGH AVN IS ONLY SLIGHTLY FASTER AND ETA 
JUST A LITTLE FASTER YET.  OVERALL WITH THIS EVENT THE SLOWEST 
SOLUTION HAS SEEMED BEST ALL ALONG...CONSIDERING THAT THE FRONT 
SHOULD NOT MOVE INTO UPPER LEVEL RIDGE VERY FAST...AND OTHER UPPER 
LEVEL FEATURES PRECLUDE A FAST MOVEMENT OF THE FRONT.  NEXT WEAK 
CHANCE IS FRIDAY NIGHT...THOUGH NOT ESPECIALLY IMPRESSED WITH 
THIS...AS THERE DOESNT SEEM TO BE ANYTHING TO FOCUS ON AT THE 
SURFACE...AND UPPER LEVEL FEATURES WEAK.  WARM MID LEVEL TEMPS WILL 
ALSO MAKE IT DIFFICULT TO GET ANYTHING GOING.  NEXT SIGNIFICANT 
CHANCE IS LATE SATURDAY NIGHT INTO SUNDAY.  WILL HAVE TO KEEP AN EYE 
ON THIS TIMING...AS LATEST MODELS ARE A LITTLE FASTER THAN GOING 
FORECAST...BUT DUE TO LATEST MODEL TRENDS...WILL LEAVE OUT OF 
SATURDAY NIGHT FOR NOW.  GUIDANCE TEMPS IN REASONABLE AGREEMENT. 
DONT EXPECT TO CHANCE GOING TEMPS TONIGHT.  TOMORROW WILL GO ON THE 
WARM SIDE AS EXPECT LOTS OF SUNSHINE AS CONVECTION SHOULD BE 
SUPPRESSED UNTIL LATE WHEN CAP FINALLY BREAKS.  THIS SHOULD GIVE 
COMPRESSIONAL HEATING AHEAD OF FRONT TO GET GOING.  FRIDAY TEMPS 
WITH NORTHEASTERLY FLOW AND LINGERING CLOUD COVER WILL BE QUITE 
COOL...UPPER 70S TO LOW 80S REASONABLE. SATURDAY HAS BEEN GETTING 
FLIP FLOPPED BY MODELS...ONE DAY THE FRONT IS NORTH...THE NEXT 
SOUTH.  KEEPING IT NORTH LINES UP FAIRLY WELL WITH LONG TERM 
MODELS...AND SEEMS TO BE THE WAY SHORT TERM MODELS ARE GOING. WHILE 
DO THINK MODEL GUIDANCE TOO COOL...WONT BE GOING AS WARM AS GOING 
FCST.

EXTENDED SUN-WED
FAST...PROGRESSIVE PATTERN CONTINUES THROUGH THE EXTENDED 
PERIOD...WITH AN UPPER LEVEL RIDGE CENTERED OVER THE SOUTHERN 
MISSISSIPPI VALLEY THROUGH MOST OF THE PERIOD.  IT STARTS OUT 
FLATTENED ON SUNDAY...AND BUILDS THE AXIS OVER THE MIDWEST FOR THE 
REMAINDER OF THE PERIOD.  SUNDAY NIGHT IT APPEARS THAT THERE WILL BE 
ANOTHER MCS...THOUGH IT SEEMS TO HAVE SHIFTED NORTH FROM PREVIOUS 
RUNS.  WILL LEAVE POPS IN ALL ZONES FOR NOW TO KEEP FROM FLIP 
FLOPPING AS LATER RUNS COME IN.  THE MCS TRAVELS SOUTHEAST ON A WEAK 
FRONT THAT WASHES OUT FOR MONDAY. BY THIS TIME THE RIDGE SHOULD BE 
STRONG ENOUGH TO KEEP ANY PRECIP FROM FORMING...SO HAVE NOT PUT ANY 
IN.  TUESDAY IS AN IN BETWEEN DAY...WITH A SURFACE LOW DEVELOPING 
OVER CO.  HINT OF A WARM FRONT DEVELOPING OVER NRN MN...WHICH 
EARLIER RUNS AND MODELS HAD PLACED IN VICINITY OF CWA.  PREFER MORE 
NORTHERLY SOLUTION AND WILL KEEP TUESDAY AND WEDNESDAY DRY AS THIS 
THING APPROACHES FROM WEST. TEMPS SUNDAY AND MONDAY ON THE COOLER 
SIDE WITH THE CLOUD COVER FROM FRONT IN VICINITY...THEN A WARMING 
TREND FOR TUESDAY AND WEDNESDAY.

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

LRE