[LeArc] Forecast Discussion : MLI@ 4/16/2003 3:02:37 AM

[learc@mailman.qth.net]

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


FXUS63 KDVN 160759
AFDMLI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
259 AM CDT WED APR 16 2003

SYNOPTIC PICTURE THIS MORNING SHOWS CLOSED 500MB LOW OVER SOUTH
CENTRAL KS...LIFTING ENE.  AT THE SURFACE...A 987MB LOW IS IN
WESTERN KS...WITH A BACKDOOR COLD FRONT EXTENDING NORTHEAST INTO
NORTHERN IA.  PRECIP ASSOCIATED WITH THE FRONT IS EDGING SOUTH ACROSS
THE IA/MN LINE. A SECOND WEAKER AREA OF PRECIP LIFTING NE INTO THE
FCST AREA IS ASSOCIATED WITH A VORT MAX.

THE MODELS INITIALIZED MODERATELY WELL AT 00Z...WITH THE AVN A BIT
DEEP AT 500MB WITH THE SOUTHERN PLAINS LOW.

THE PRIMARY FORECAST CONCERNS ARE TWO-FOLD.  FIRST IS THE EVOLVING
SYSTEM MOVING THROUGH THE FORECAST AREA IN THE NEXT 24 HOURS.  THE
SECOND IS A SYSTEM MOVING OUT OF THE SOUTHERN PLAINS AND AFFECTING
THE AREA FRIDAY NIGHT THROUGH SUNDAY.

THE MODELS HAVE COME INTO LINE ON THE FIRST SYSTEM. THE BACKDOOR COLD
FRONT PUSHES SOUTH OF INTERSTATE 80 BY 18Z AND SOUTH OF THE FCST AREA
BY 00Z...IN RESPONSE TO HIGH PRESSURE BUILDING INTO ONTARIO.  THE
KANSAS SURFACE LOW MOVES EAST ALONG THE FRONT TONIGHT...THRU STL
AROUND 06Z TONIGHT...AND THEN THE FRONT AND LOW KICK EAST THURSDAY.
AT 500MB THE CLOSED LOW MOVES OVER STL JUST AFTER 06Z TONIGHT. PVA
CONTINUES ACROSS MUCH OF THE AREA TIL 06Z TONIGHT...WITH MODERATE
700MB VV'S BUT NO 300MB DIVERGENCE.

THE SECOND SYSTEM IS A DIFFERENT QUESTION...WITH THE MODELS STILL
WIDELY APART.  THIS SYSTEM HAS THE POTENTIAL TO BE A HEAVY RAIN-
MAKER. THE MRF LIFTS AN INVERTED SURFACE TROF OR WARM FRONT INTO THE
AREA FRIDAY NIGHT...WHERE IT STALLS AND STRENGTHENS WITH A CLOSED LOW
LIFTING NORTH TO EAST OF DVN BY SUNDAY EVENING. THE UK AND EUROPEAN
BRING THIS LOW NORTH WEST OF THE FORECAST AREA...THUS PROVIDING A
WARMER BUT LOWER PRECIP SOLUTION.

WILL KEEP ON CURRENT TRACK...WITH JUST MINOR TWEAKS.  WILL KEEP
CHANCE WORDING FOR THIS WEEKEND...UNTIL MODELS COME TOGETHER.  MAY
TAKE PRECIP OUT FOR MONDAY.

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

$$

REA