[LeArc] Forecast Discussion : MLI@ 6/29/02 2:23:33 AM

[learc@mailman.qth.net]

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


FXUS63 KDVN 290721
AFDMLI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
221 AM CDT SAT JUN 29 2002

EVENING UPPER AIR ANALYSIS INDICATES THAT THE UPPER RIDGE IS WELL
IN PLACE OVER THE CENTRAL U.S.  HEIGHT RISES EVIDENT ON BACK SIDE OF
TROUGH OVER THE NORTHEAST WITH LITTLE HEIGHT FALLS INDICATING RIDGE
WILL STAY PUT FOR A WHILE.  WAVE RIDING OVER TOP OF RIDGE...ACROSS
MONTANA AND THE DAKOTAS...PRODUCING SHOWERS AND THUNDERSTORMS. LATEST
SURFACE ANALYSIS PLACES HIGH PRESSURE CENTER OVER INDIANA...BUT MSAS
INDICATING HIGH PRESSURE RIDGING BUILDING BACK TO THE WEST ACROSS OUR
FORECAST AREA DURING PAST THREE OR FOUR HOURS.  SURFACE BOUNDARY
STALLED OUT ACROSS THE OHIO RIVER VALLEY EXTENDING BACK ACROSS
SOUTHERN MISSOURI...INTERSECTING TROUGH/DRY LINE ACROSS NEBRASKA AND
KANSAS.

NEXT FEW DAYS TEMPERATURES WILL CONTINUE TO BE MAIN FORECAST
CHALLENGE. IN THE EXTENDED...WILL NEED TO KEEP AN EYE ON THE TIMING
OF POPS...BUT TO FAR OUT TO START ANY TYPE OF YO YO IN AND OUT TREND
AT THIS TIME.

LOOKING AT THE NEAR TERM...THE ETA AND AVN INITIALIZED FAIRLY CLOSE
WITH THE ETA PICKING UP THE DAKOTAS SHORT WAVE BETTER THAN THE AVN
BUT ITS PLACEMENT OF PRECIPITATION NOT VERY GOOD.  THE MEDIUM RANGE
MODELS APPEAR TO BE IN PRETTY GOOD AGREEMENT THIS TIME AROUND.

FORECAST REASONING IN THE EARLY GOING WILL STAY WITH CURRENT TREND OF
CONTINUED HEAVY RAIN THREAT ACROSS THE NORTH CENTRAL STATES...WITH
OUR FORECAST AREA HOT...HAZY AND MUGGY.  PREVIOUS FORECASTER
INTRODUCED 100 DEGREE HEAT INDEX WORDING PRIMARILY FOR SUNDAY AND
MONDAY...GOOD CALL. CALCULATIONS INDICATE THAT WE NEED SOME LOW 90S
OVER SOME LOW TO MID 70 DEW POINTS TO PRODUCE HEAT INDICES OF AROUND
100.  MID 90S OVER MID 70 DEW POINTS WOULD PUT US IN THE HEAT
ADVISORY CRITERIA AND THAT WILL NEED TO BE WATCHED.

LOOKING AT THE EXTENDED...ESPECIALLY LATE...JULY 4 AND FRIDAY...HAVE
POPS ALREADY GOING.  NOT A LOT OF CONFIDENCE AT THIS TIME...AND AS
STATED ABOVE...DO NOT WANT TO YO YO THIS FAR OUT.  IT BOILS DOWN TO
THE FRONTAL BOUNDARY ACROSS THE NORTHERN STATES.  IF IT STAYS
NORTH...WE STAY WARM WITHOUT MUCH CHANCE OF RAIN.  IF IT BACKS INTO
OUR FORECAST AREA...TEMPERATURES WILL BE A LITTLE COOLER AND WE DEAL
WITH CHANCE OF SHOWERS AND THUNDERSTORMS.  WILL WANT TO WAIT FOR
LATER MODEL RUNS AND HIGHER CONFIDENCE BEFORE CONSIDERING ANY
CHANGES.

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

MEYER