[LeArc] Forecast Discussion : MLI@ 11/30/02 1:04:11 PM

[learc@mailman.qth.net]

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


FXUS63 KDVN 301918
AFDMLI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
115 PM CST SAT NOV 30 2002

.OVERVIEW...STRONG SYSTEM NOW MOVING WELL EAST OF AREA RESPONSIBLE
FOR MUCH COLDER TEMPS AND VERY WINDY CONDITIONS EARLIER TODAY.  AT
19Z...CLEARING LINE BISECTING AREA AND SHOULD BE EAST OF ENTIRE
REGION AROUND 23Z. SURFACE HIGH APPROACHING FROM WEST SUPPORTING
WINDS TO DECREASE TO 5 TO 15 MPH BY EVENING DIMINISHING TO AROUND 5
MPH LATE. UPPER JET OF 160+ MPH DIVING OUT OF CENTRAL CANADA SHOWS
LARGE HEIGHT RISES SUPPORTS WARMER EASTWARD PROGRESSION.  NEXT
SHORTWAVE THOUGH NOW INTO YUKON TO AFFECT AREA 36 TO 48 HOURS.
SATELLITE SUGGESTS AS SFC OBS DO CLEARING TONIGHT WITH SOME PARTLY
CLOUDY SKIES SUNDAY AHEAD OF NEXT APPROACHING SYSTEM AND WARM FRONT.

...TEMPS NEAR TERM AND THEN POPS MONDAY WITH NEXT SYSTEM AND MORE
COLD TEMPS LONGER TERM ISSUES...

.DIAGNOSIS AND DAYS 1-3...USE SFC UPSTREAM DEWPOINTS AND NOWCAST
TOOLS TO ADJUST LOW TEMPS TONIGHT WHICH SUPPORT LOW SIDE BY 1-2
CATEGORIES MODEL BLEND WITH COLD RADIATIONAL COOLING AND PERSISTENCE
ALSO SUGGESTED AS DRY DEWPOINTS OF 5 ABOVE OR LESS EXPECTED.  THEN
PARTLY CLOUDY AND NEAR BREEZY SW WINDS SUNDAY TO ALLOW FOR DECENT
WARMUP AND WILL PLAN FOR HIGH TEMPS NEAR BLEND.  WITH WAA AND SOME
CLOUDS INCREASING SUNDAY NIGHT AHEAD OF NEXT SYSTEM...WILL GO 1-2
CATEGORIES ABOVE FOR LOWS AND THEN BIG CHALLENGE OF POPS AND TEMPS
MONDAY WITH NEXT SYSTEM.  ALL MODEL SUGGEST MODERATE FORCING AND SFC
LOW TO DEVELOP WEAK-MODERATE CLOSED LOW NORTH OF MCI THAT MOVES INTO
ILLINOIS BY LATE MONDAY.  FAVORABLE FORCING AND UPPER TROUGH
CONCEPTUALLY IN LINE FOR LIKELY POPS WHICH GFS-AVN AND UKMET SUPPORT.
ETA TOO DRY AS USUAL FOR SYSTEM THIS TYPE AS USUAL...THO IT SUPPORTS
FORCING WHICH IS IMPORTANT ITEM.  NGM TRENDING TOWARD GFS-AVN AND
UKMET SOLUTION AT 48 HOURS. THUS...GO ABOVE TO WELL ABOVE POPS WITH
LIKELY NORTH 2/3 AND 30-40 POPS SOUTH.  SNOW NORTH AND RAIN CHANGING
TO SNOW SOUTH. DYNAMICS CONSISTENT FOR 1-3 INCHES REASONABLE BY
MONDAY EVENING NORTH OF HIGHWAY 34.  WITH SNOW COVER AND NEXT ARCTIC
SHOT...KEEP TEMPS BELOW GUIDANCE TUESDAY SIMILAR TO LAST EVENT.

.EXTENDED (WED-SAT)...WILL FOLLOW LATEST GFS-AVN AND UKMET WHICH
KEEP AREA UNDER INFLUENCE OF ARCTIC HIGH FOR TEMPS NEAR TO SLIGHTLY
BELOW MEX...ESPECIALLY FOR LOWS.  UPPER TROUGH SUGGEST SOME S-- LATE
WEDNESDAY INTO EARLY THURSDAY.  DECENT WARMUP SUGGESTED BY SATURDAY
WITH ANOTHER NW SYSTEM AS WE REMAIN UNDER INFLUENCE OF VIGOROUS JAMES
BAY UPPER VORTEX.

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

NICHOLS