[LeArc] Forecast Discussion : MLI@ 7/24/02 2:15:46 PM

[learc@mailman.qth.net]

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


FXUS63 KDVN 241915
AFDMLI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
215 PM CDT WED JUL 24 2002

SYNOPTIC PICTURE THIS AFTERNOON SHOWS 70KT JET OVER NORTHERN GREAT
LAKES.  AT 500H...NEAR ZONAL FLOW PREVAILS ACROSS THE NORTHERN THIRD
OF THE COUNTRY...EXCEPT FOR A VIGOROUS SHORT WAVE DIGGING INTO WESTERN
MINNESOTA.  AT THE SURFACE...A STRONG 1027 HIGH IS CENTERED OVER THE
GREAT LAKES...WITH LIGHT SOUTHEAST FLOW AND LOW DEW POINTS ACROSS THE
FORECAST AREA.  SCATTERED SHOWERS ACROSS SOUTHERN MINNESOTA ARE IN
RESPONSE TO SHORT WAVE...WHILE THUNDERSTORMS BACK INTO EASTERN DAKOTAS
ARE THE RESULT OF SECOND TRAILING SHORT WAVE.  HIGH CLOUDS OVER THE
FORECAST AREA ARE BLOW-OFF FROM WYOMING CONVECTION YESTERDAY.  SURFACE
DEW POINTS ACROSS ARKANSAS...OKLAHOMA...AND KANSAS ARE 65 TO 75.

PRIMARY FORECAST CONCERNS THIS PACKAGE ARE SEVERAL-FOLD. FIRST IS
SHORT WAVE LATE TONIGHT INTO THURSDAY...WHICH WILL PRODUCE SCATTERED
CONVECTION...MAINLY NORTH.  SECOND IS A TROF THURSDAY NIGHT...THIRD IS
A SHORT WAVE SATURDAY NIGHT...AND FOURTH IS A COLD FRONT IN THE SUNDAY
EVENING/NIGHT TIME FRAME. MAIN THEMES ARE INCREASING DEW POINTS
THURSDAY...AND INCREASED POPS THRU MUCH OF THE FORECAST PERIOD.

MODELS AGREE ON SHORT WAVE LATE TONIGHT AND EARLY THURSDAY...POSSIBLY
INTO MIDDAY...MAINLY NORTH. LOW-LEVEL JET WILL FOCUS WELL NORTH OF THE
AREA...WITH THICKNESSES ONLY INDICATING SLIGHT SOUTHERN DRIFT
POSSIBLE. HOWEVER...CORFIDI VECTORS ALSO INDICATE DEVELOPMENT SOUTH
INTO THE FORECAST AREA.  SCATTERED PRECIP WILL PROBABLY ENTER NORTHWEST
PORTION OF FORECAST AREA LATE TONIGHT...MAYBE 09Z.  SPC PUTS FORECAST
AREA...ALL EXCEPT EXTREME SOUTH...IN SLIGHT RISK FOR SEVERE TONIGHT...
WITH THREAT OF HAIL AND HIGH WINDS BEING HIGHEST INTO NORTH CENTRAL
AND NORTHWEST IOWA...AND SOUTHWEST MINNESOTA.

A SURFACE TROF THURSDAY NIGHT...ACCOMPANIED BY A WEAK 500H SHORT WAVE
AND VORT...WILL PRODUCED ANOTHER CHANCE OF PRECIP THURSDAY NIGHT INTO
FRIDAY.  ANOTHER SHORT WAVE IS POSSIBLE SATURDAY NIGHT...WITH A COLD
FRONT FOLLOWING IN THE SUNDAY EVENING/OVERNIGHT PERIOD...WITH THE
FRONT SLOWING UP ACROSS THE SOUTH MONDAY...AS A LOW MOVES EAST ACROSS
THE AREA. THE EUROPEAN AND UK AGREE ON THIS GENERAL SCENARIO.

WILL STAY CLOSE TO CURRENT FORECAST. NUMERICAL GUIDANCE NOT VERY
CONSISTENT BETWEEN MODELS THRU 48 HOURS.

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

REA