[LeArc] Forecast Discussion : MLI@ 8/15/02 2:33:39 AM

[learc@mailman.qth.net]

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


FXUS63 KDVN 150737
AFDMLI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
236 AM CDT THU AUG 15 2002

SYNOPTIC PICTURE THIS MORNING SHOWS BROAD TROF OVER CENTRAL U.S...
WITH SHORT WAVE DIGGING INTO THE DAKOTAS.  AT UPPER LEVELS...A 110KT
JET IS DIGGING INTO MONTANA.  AT THE SURFACE...A COLD FRONT EXTENDS
FROM WESTERN NEBRASKA INTO NORTH CENTRAL MINNESOTA...WITH A 997 LOW IN
SOUTH DAKOTA.  CONVECTION ACROSS THE NORTHERN HALF OF SOUTH DAKOTA IS
IN RESPONSE TO SHORT WAVE.  ACROSS AND NEAR THE FORECAST AREA...SKIES
ARE CLEAR WITH DEW POINTS STILL IN THE UPPER 50S.

THE PRIMARY FORECAST CONCERNS THIS PACKAGE ARE THREE-FOLD.  FIRST IS
POSSIBLE PRECIP ASSOCIATED WITH A WEAK COLD FRONT TONIGHT. SECOND IS
CONVECTION ASSOCIATED WITH A STRONGER COLD FRONT ON SATURDAY. THIRD IS
PRECIP WITH A MORE COMPLEX WEATHER PATTERN IN THE MONDAY-WEDNESDAY TIME
FRAME.

THE SHORT-TERM MODELS AGREE ON THE FIRST COLD FRONT MOVING THRU DVN
AROUND 06Z TONIGHT...THEN STALLING JUST SOUTH AND EAST OF THE AREA
AROUND 12Z FRIDAY...AND LIFTS BACK NORTH FRIDAY EVENING. A 500H SHORT
WAVE ASSOCIATED WITH THIS FRONT WILL MOVE THRU THIS EVENING...WITH
ALMOST ALL OF THE PVA NORTH INTO MINNESOTA AND WISCONSIN.  VV'S WILL BE
MODERATELY STRONG BETWEEN 00Z AND 06Z. LOW-LEVEL JET NEVER COMES INTO
PLAY.  ON FRIDAY AFTERNOON/EVENING THE FRONT LIFTS BACK NORTH THRU THE
FORECAST AREA AS A WARM FRONT...BUT WILL LITTLE DYNAMIC SUPPORT FOR
PRECIP.  THE AVN AND MEDIUM-TERM MODELS AGREE MODERATELY WELL ON THE
TIMING OF A STRONGER COLD FRONT SATURDAY...AROUND 18Z.  STRONG VV'S
AND UPPER DIVERGENCE WILL PRODUCE WIDESPREAD CONVECTION...POSSIBLY INTO
THE EVENING.  THE NEXT CHANCE OF PRECIP WILL BE WITH A STATIONARY
FRONT FORMING MONDAY ACROSS NORTH CENTRAL MISSOURI...ALTHO NEW MRF RUN
BACKS OFF ON PRECIP FOR MONDAY...ALTHO MONDAY NIGHT STILL A GOOD
CHANCE. THE FRONT IS EXPECTED TO LIFT NORTH THRU THE AREA TUESDAY AS A
WARM FRONT...AHEAD OF A STRONG COLD FRONT THAT WILL SWEEP THRU
WEDNESDAY NIGHT.

WILL ADJUST POPS IN CURRENT FORECAST TO FOCUS MORE ON SATURDAY THAN
SATURDAY NIGHT.  WILL ALSO LOWER TEMPS A NOTCH SATURDAY PER FASTER
TIMING.  OTHERWISE ONLY MINOR CHANGES.

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

REA