[LeArc] Forecast Discussion : MLI@ 6/8/02 2:05:21 AM

[learc@mailman.qth.net]

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


FXUS63 KDVN 080704
AFDMLI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
204 AM CDT SAT JUN 8 2002

AS EXPECTED LAST NIGHT...LATEST SURFACE ANALYSIS AND PAST SEVERAL
HOURS OF MSAS DATA SUGGEST THAT FRONTAL BOUNDARY EXTENDING ACROSS
NEBRASKA AND SOUTHERN MINNESOTA HAS BECOME PRETTY MUCH STATIONARY.
SURFACE CONVERGENCE COMBINED WITH SLIGHT DIFFLUENT FLOW AT 300 MB
ENOUGH TO MAINTAIN DECENT THUNDERSTORM ACTIVITY ACROSS NEBRASKA.
THUNDERSTORMS IN SOUTHEAST SOUTH DAKOTA AND SOUTHWEST MINNESOTA
IN LINE WITH JET STREAK AT 300 MB.  ACROSS OUR FORECAST AREA NOT MUCH
CHANGE FROM LAST NIGHT.  HIGH PRESSURE SYSTEM NOW CENTERED OVER
NORTHEAST U.S. WITH CONTINUED SOUTHERLY FLOW ACROSS ENTIRE FORECAST
AREA.  STRONG LOW LEVEL WARM AIR ADVECTION WILL DO TWO THINGS...WARM
UP TODAYS HIGHS...AND KEEP THE FRONTAL BOUNDARY NORTH AND WEST OF OUR
FORECAST AREA WHICH WILL KEEP OUR WEEKEND RAINFREE AND WARM.

MAIN FORECAST CHALLENGES THIS PACKAGE FOR THE MOST PART IN THE
LATER PERIODS STARTING MONDAY ALL THE WAY INTO WEDNESDAY.  LOW LEVEL
CONVERGENCE INTENSIFIES MONDAY WITH FRONT FINALLY MOVING ACROSS OUR
FORECAST TUESDAY WITH OUR BEST CHANCE OF SHOWERS AND THUNDERSTORMS.
THERE MAY BE SOME LINGERING RAIN WEDNESDAY...MAINLY MORNING...BUT IT
IS NOT IN THE CURRENT PACKAGE AND NOT ENOUGH CONFIDENCE TO ADD AT
THIS TIME.

ETA AND AVN INITIALIZED NEARLY IDENTICAL WITH 500 MB HEIGHTS AT 00Z.
PRECIPITATION FIELDS WERE UNDERDONE OVER NEBRASKA BUT ALL IN ALL...
NOT TOO BAD.  LOOKING BACK AT LAST NIGHT...THE MODELS HINTED AT JUST
A SLIGHT CHANCE OF THUNDERSTORMS ALONG OUR HIGHWAY 20 IOWA
COUNTIES...AND LOOKING BACK AT PAST RADAR...JUST MISSED...BUT WAS
WORTH THE 20 OR 30 PERCENT WORDING.

GOING PACKAGE LOOKS VERY GOOD.  WARMING TREND IS WELL ADVERTISED AND
THE INCREASE IN LOW LEVEL MOISTURE...HIGHER DEW POINTS...WILL BE
ESPECIALLY NOTED ON SUNDAY.  MONDAYS CHANCE OF THUNDERSTORMS STILL
LOOKS REASONABLE AS LOW LEVEL CONVERGENCE AND MIDDAY HEATING WILL BE
THE PRIMARY TRIGGER.  MODELS ALSO KICK OUT A SHORTWAVE...RIDGE
RIDER...WHICH SHOULD HELP TRIGGER SHOWERS AND THUNDERSTORMS
ESPECIALLY OVER THE NORTH PART OF OUR FORECAST AREA.

LOOKING AT THE EXTENDED FORECAST...A FEW DIFFERENCES SHOW UP THURSDAY
WITH MRF AND UKMET COMING UP WITH SOME DIFFERENT SOLUTIONS ON THE
SYSTEM MOVING ACROSS SOUTHERN CANADA. CURRENT PACKAGE HAS ALREADY
COVERED THIS UNCERTAINTY AND NO REASON FOR ANY CHANGES AT THIS TIME.

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

MEYER