[LeArc] Forecast Discussion : MLI@ 2/18/03 1:48:52 AM

[learc@mailman.qth.net]

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


FXUS63 KDVN 180757
AFDMLI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
150 AM CST TUE FEB 18 2003

.OVERVIEW...ZONAL FLOW RETURNING AT SURFACE AND ALOFT WITH WEAK WARM
FRONT PASSING ACROSS AREA AT 07Z AND TO BE EAST OF REGION BY
DAYBREAK.   MILDER TEMPERATURES IN STORE WITH LESS CLOUDS UPSTREAM
PER ANALYSIS AND SUPPORTED BY SATELLITE.  PROFILERS SUPPORT 20 TO 25
KT BL WINDS FOR SOME DAYTIME WINDS FROM SUNSHINE INDUCED MIXING TODAY.
NEXT MAJOR SYSTEM JUST APPROACHING WEST COAST WITH SOUTHERN TRACK
SUGGESTING LIMITED IMPACTS TO FORECAST AREA...IF AT ALL.

...WARMUP NEXT COUPLE DAYS AND THEN NEXT SYSTEM FRIDAY AND SATURDAY
LONGER TERM ISSUE...

.DIAGNOSIS AND DAYS 1-3...LITTLE SENSIBLE WEATHER NOTED WITH SOUTHERN
CALIFORNIA SYSTEM TO SLIDE JUST SOUTH AREA WITH SLIGHT CHANCE OF SOME
SNOW SOUTHERN ROW OF COUNTIES POSSIBLY FROM NORTHERN EDGE OF BAROCLINIC
LEAF TONIGHT.  BIGGEST ISSUE IS ASSESSING SNOW COVER IMPACTS ON MAX
TEMPS TODAY.  SHOULD SEE SOME DECENT MELTING TODAY WITH SUN AND WEST
WINDS UP TO 15 TO 25 MPH MID DAY TODAY. THIS SHOULD ALLOW FOR HIGH TEMPS
NEAR GUIDANCE BLEND.   LOWS TONIGHT WILL BE WARMER SOUTH WITH SOME
CLOUDS AND SLIGHT CHANCE OF SNOW AGAIN FROM SOUTHERN CALIFORNIA SYSTEM.
MINOR CHANGES WEDNESDAY WITH WEAK WIND SHIFT LINE BUT LITTLE CHANGE TO
TEMPS.  THURSDAY GET MORE SOUTHERLY FLOW AHEAD OF SIGNIFICANT SYSTEM
THAT WILL ALLOW FOR WARMER TEMPERATURES AND EXPECT ALL OR MOST OF SNOW
TO BE GONE WITH HIGHER AND STRONGER LATE FEBRUARY SUN NEXT COUPLE DAYS.

.EXTENDED RANGE(THU-SUN)...JUST WHEN THINK MODELS HAVE A DECENT
HANDLE ON A SYSTEM THEY CHANGE...WHICH SEEMS MORE THAN NORMAL THIS
WINTER.  BIGGEST ISSUE IS SOUTHERN DISPLACEMENT OF SOUTHERN TRACK
OF LATE WEEK SYSTEM WHICH WAS SUGGESTED YESTERDAY IN JET PROFILE...
BUT NOT BY THIS MUCH.  APPEARS LOTS OF ENERGY TO SLIDE INTO SOUTHERN
PORTION OF JET SPLIT FLOW WITH PHASING OF BOTH STREAMS INTO LARGE
SINGLE SYSTEM TO OCCUR OVER OR MAINLY JUST EAST OF OUR AREA.
SO..WITH CHANGE THIS RUN WILL HOLD OFF ON ANY CHANGES TO CURRENT
FORECAST WITH KEEPING LIKELY POPS FRIDAY WHICH STILL LOOKS GOOD OF
RAIN AND/OR SNOW.  CURRENT HWO WORDING REMAINS REASONABLE WITH
FORTUNATELY LESS CHANCE OF VERY STRONG SYSTEM AND WILL KEEP
UNCERTAINTY EMPHASIS.  THIS TREND OF SOUTHERN TRACK IS IN LINE WITH
OR WINTER PATTERN (EL NINO INFLUENCE).  THUS EXPECT AT LEAST PART OR
MOST OF NEXT SYSTEM TO BE IN LINE WITH WHAT WILL HAPPEN. NEXT ISSUE
IS UPSTREAM ENERGY PHASING WITH ANOTHER CHANCE OF SNOW WITH ARCTIC
AIR SUNDAY AND POSSIBLY INTO MONDAY DEPENDING ON MODEL SOLUTION.

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

$$

NICHOLS