[LeArc] Forecast Discussion : MLI@ 9/10/02 1:55:09 PM

[learc@mailman.qth.net]

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


FXUS63 KDVN 101900
AFDMLI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
200 PM CDT TUE SEP 10 2002

LATEST SURFACE ANALYSIS AND MSAS DATA INDICATES SURFACE FRONT WAS
RIGHT ON SCHEDULE MOVING ACROSS FORECAST AREA...CROSSING THE
MISSISSIPPI RIGHT AROUND 18Z.  WILL MOVE ACROSS WEST CENTRAL AND
NORTHWEST ILLINOIS BY LATE AFTERNOON.  COOLER DRYER AIR WILL BE WELL
IN PLACE TO TAKE DOWN OVERNIGHT LOWS INTO THE COMFORTABLE READINGS...
THAT HAVE BEEN FORECAST FOR THE PAST FEW DAYS.  NOT MUCH UPPER
SUPPORT TO HELP WITH RAIN DEVELOPMENT BUT ENOUGH LOW LEVEL MOISTURE
TO PRODUCE A FEW SHOWERS. WILL MAYBE HAVE A FEW LINGERING SHOWERS
PRIMARILY ON THE ILLINOIS SIDE OF THE FORECAST AREA THIS EVENING
BETWEEN DUBUQUE AND FREEPORT...BUT THESE WILL BE SPOTTY AT BEST.
CHANCE OF THUNDER NOT LOOKING GOOD AT THIS TIME. BEST UPPER LEVEL
SUPPORT REMAINS NORTH OF OUR FORECAST AREA WITH BEST PRESSURE RISE
FALL ACTIVITY TAKING PLACE WELL NORTH OF OUR FORECAST AREA.

FORECAST CHALLENGES IN THE NEAR TERM WILL BE TIMING OF THE SHOWERS...
AND WHEN TO CLEAR THEM FROM THE NORTHEAST PART OF OUR FORECAST AREA.
WILL ALSO HAVE TO DEAL WITH POST FRONTAL DEBRIS WITH THIS SYSTEM.
ALSO...HOW COOL WILL IT GET TONIGHT?  WILL PROBABLY BE TAKING
OVERNIGHT LOWS DOWN SOME. IN THE LONGER TERM...WILL HAVE TO KEEP AN
EYE ON THE FRIDAY SATURDAY TIME FRAME WHEN NEXT SHOT OF COLD
REINFORCEMENT ARRIVES. THINKING AT THIS TIME TO ADD CHANCE OF LIGHT
RAIN TO FRIDAY FORECAST AND LEAVE SATURDAY ALONE.

MODELS STILL BUILDING UPPER RIDGE OVER FORECAST AREA LATE IN THE WEEK
WHEN IT STARTS TO BREAK DOWN.  ECMWF AND GLOBAL 500 HEIGHTS ARE IN
FAIRLY GOOD AGREEMENT INTO DAY 5.  DAY 6 AND 7 START GOING THEIR OWN
WAY.

AFTER A DISCUSSION WITH SHORT TERM FORECASTER...MAY HAVE TO KNOCK
LOWS TONIGHT DOWN A NOTCH OR TWO.  THINKING SOME MID TO UPPER 40S NOT
OUT OF THE QUESTION ACROSS THE NORTHWEST PART OF FORECAST AREA...
ESPECIALLY ALONG THE HIGHWAY 20 CORRIDOR. OTHERWISE...HAVE A GOOD
FEELING ABOUT THE MODELS AND THE FORECAST INTO THE WEEKEND. WILL
INTRODUCE SOME POPS ON FRIDAY AS GLOBAL MOISTURE FIELDS INDICATE SOME
TYPICAL UPGLIDE ACROSS THE MIDWEST.  WITH SHALLOW COLD AIR IN PLACE
BY THEN...THIS SEEMS TO MAKE SENSE.  WILL HOLD ONTO POPS INTO
SATURDAY.

SUNDAY INTO TUESDAY...CONFIDENCE NOT AS HIGH IN MODEL DATA.  FOR NOW
WILL GO WITH BROAD CYCLONIC TROUGH LINGERING OVER THE MIDWEST ON
SUNDAY. IF THIS HOLDS TRUE...THESE ARE USUALLY SLOW TO CLEAR OUT.
MONDAY AND TUESDAY WILL STAY DRY AND COOL UNDER THE INFLUENCE OF
NORTHWEST FLOW.

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

MEYER