[LeArc] Forecast Discussion : MLI@ 7/25/02 2:36:38 PM

[learc@mailman.qth.net]

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


FXUS63 KDVN 251936
AFDMLI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
236 PM CDT THU JUL 25 2002

SYNOPTIC PICTURE THIS AFTERNOON SHOWS A 80KT JET OVER SOUTH DAKOTA. AT
500H...A SHORT WAVE JUST NORTH IS EXITING TO THE EAST...WITH SHOWERS
ACROSS SOUTHWEST WISCONSIN.  AT THE SURFACE...AT TROF EXTENDS FROM
EASTERN MANITOBA TO A 1010MB LOW IN CENTRAL KANSAS.  DEW POINTS ARE
BACK UP INTO THE 67 TO 70 RANGE.

PRIMARY FORECAST CONCERN IS TWO-FOLD.  FIRST IS THE PLAINS TROF...WHICH
WILL SINK SOUTHEAST ACROSS THE FORECAST AREA LATE TONIGHT AND FRIDAY.
SECOND IS A COLD FRONT IN THE MONDAY NIGHT/TUESDAY TIME FRAME.  MUCH OF
THE GUIDANCE AVAILABLE FOR THIS PACKAGE IS FROM 00Z AND 06Z...SINCE THE
12Z GUIDANCE HAS BEEN DELAYED AND/OR WILL NOT BE RUN...DUE TO THE
NATIONAL BACKUP MODEL DISSEMINATION EXERCISE THAT TOOK PLACE THIS
MORNING.

THE SHORT-TERM MODELS ARE IN MODERATE AGREEMENT ON BRINGING THE
SURFACE TROF ACROSS THE FORECAST AREA TONIGHT OR LATE TONIGHT...TO JUST
SOUTH OF THE AREA BY FRIDAY AFTERNOON. DISAGREEMENT OCCURS AFTER THAT...
WITH THE AVN LIFTING THE FRONT BACK NORTH FRIDAY NIGHT...AND THE ETA AND
NGM KEEPING IT SOUTH THROUGH SATURDAY.  A 100KT JET WILL BE JUST NORTH
OF THE AREA THROUGH SATURDAY...BRINGING SOME UPPER SUPPORT BY WAY OF
250H DIVERGENCE...ESPECIALLY FROM 12Z TO 18Z FRIDAY.

LOOKING FURTHER AHEAD...THE MEDIUM-RANGE MODELS ARE IN MODERATE
AGREEMENT IN A COLD FRONT IN THE MONDAY NIGHT/TUESDAY TIME FRAME...
WITH THE MRF BEING EARLIER AND THE EUROPEAN AND UK BEING LATER.

WILL KEEP CLOSE TO ONGOING FORECAST.  MAIN CHALLENGE WILL BE TO LIMIT
THE NUMBER OF PERIODS WITH POPS.  WILL TRIM DOWN OR ELIMINATE IN AT
LEAST ONE OR TWO PERIODS.  TEMPS ON THE RIGHT TRACK.  COOL DOWN NEXT
WEDNESDAY/THURSDAY...ALTHOUGH MINIMAL...MAY BE SLIGHTLY MORE THAN 00Z
MRF/MEX.

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

REA