[LeArc] Forecast Discussion : MLI@ 7/23/02 1:57:32 PM

[learc@mailman.qth.net]

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


FXUS63 KDVN 231856
AFDMLI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
150 PM CDT TUE JUL 23 2002

WNW H5 FLOW DOMINATES REGION THROUGH THURSDAY. BY FRIDAY FLOW FLATTENS
AS SYSTEM MOVES THROUGH WESTERN CANADA.  AT THE SURFACE CANADIAN HIGH
PRESSURE OVER NORTH CENTRAL U.S. SLIDES EAST INTO NEW ENGLAND BY
THURSDAY. LOW PRESSURE TROF DEVELOPING OVER PLAINS IN RESPONSE TO S/W
MOVING THROUGH ROCKIES...WILL PROVIDE NEXT CHANCE OF RAIN TO REGION
FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY. RAIN CHANCES WILL CONTINUE
INTO SATURDAY AS FRONT STALLS TO OUR SOUTH THEN LIFTS BACK NORTH.

MAIN SHORT TERM CONCERN WILL BE LOW TEMPS TONIGHT. ETA 2M TEMPS AND
SURFACE TRAJECTORY FORECASTS SUGGEST THAT TEMPS COULD DIP TO NEAR
RECORD READINGS IN NORTHEAST CWA.  DBQ'S RECORD LOW IS 51 WHILE MLI IS
54. LATE AFTERNOON DEWPOINTS STILL IN LOW TO MID 60S OVER CWA...HOWEVER
THESE MAY BE THE RESULT OF SOME POOLING NEAR WEAK TROUGH OVER SE CWA.
UPSTREAM DEW POINTS...IN THE MID 40S TO LOW 50S...SHOULD ADVECT IN
OVERNIGHT.  WILL NOT GO AS COOL AS ETA 2M TEMPS AND KEEP LOWS JUST
ABOVE RECORD VALUES IN THE NE QUARTER.  ANOTHER FACTOR TO CONSIDER
WILL BE CLOUDS.  A BAND OF ST MOVED OFF LM LAST NIGHT INTO NRN HALF OF
CWA.  MODELS KEEP 10 TO 15 KT FLOW OFF LM OVERNIGHT...SO MORE CLOUDS
ARE POSSIBLE.  TEMPS WEDNESDAY SHOULD BE NEAR OR JUST ABOVE TODAYS
READINGS WITH CONTINUED EASTERLY SURFACE FLOW AND SOME CU REDEVELOPING.
MAV/FWC NUMBERS LOOK REASONABLE.  WEDNESDAY NIGHT STILL LOOKS COOL
WITH WARM FRONT ASSOCIATED WITH NEXT SYSTEM TO OUR SOUTHWEST. THERE
SHOULD BE MORE CLOUDS THOUGH AS MCS DEVELOPS NEAR BOUNDARY OVER MO RIVER
VALLEY...SO LOWS AROUND 60 STILL LOOK GOOD.  AVN FASTER ON SYSTEM
MOVING IN LATE WEDNESDAY NIGHT/THURSDAY.  CONSENSUS BETWEEN
ETA/NGM/UKMET FAVOR A SLOWER SOLUTION WHICH IS CONSISTENT WITH
PREVIOUS RUNS.  WILL PLACE A LOW CHANCE POP IN THE WEST LATE WEDNESDAY
NIGHT...AND CONTINUE CHANCE POPS ENTIRE CWA THURSDAY AND ON INTO
FRIDAY AS WEAK FRONT MOVES THROUGH.


EXTENDED (SAT THRU TUES)
LONG RANGE MODELS CONTINUE TO DEPICT A BROAD TROUGH DEVELOPING OVER
NORTHERN U.S. DURING THE PERIOD.  A COUPLE OF IMPULSES MOVING THROUGH
THE TROUGH WILL PROVIDE A CHANCE OF RAIN THROUGH THE PERIOD.  WARM FRONT
SITUATED JUST SOUTH OF CWA EARLY IN THE PERIOD LIFTS NORTH THROUGH CWA
SATURDAY. MODELS IN AGREEMENT ON COLD FRONT LOCATION SUNDAY MORNING
FROM WRN KS THROUGH SE SD INTO NORTHERN MN.  HOWEVER...MRF MOVES FRONT
RAPIDLY EAST THROUGH MS VALLEY BY EARLY MONDAY...WHILE UKMET/ECMWF
SUGGEST FRONT STAYS WEST OF CWA.  EITHER WAY...WILL HAVE TO CONTINUE
POPS SUNDAY AND MONDAY...BUT WILL LEAN TOWARD SLOWER SOLUTION AND BUMP
TEMPS A LITTLE OVER MEX NUMBERS.

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

DLF