[LeArc] Forecast Discussion : MLI@ 6/12/2003 3:34:03 AM

[learc@mailman.qth.net]

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


FXUS63 KDVN 120830
AFDMLI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
330 AM CDT THU JUN 12 2003

SURFACE LOW OVER SOUTHERN INDIANA EARLY THIS MORNING AND HIGH 
PRESSURE OVER SERN CANADA STILL PROVIDING EASTERLY FLOW OVER MID 
MISSISSIPPI VALLEY.  FORECAST BUSTING STRATUS MAKING A RETURN TO 
CWA. AS OF 07Z STRATUS COVERED MOST OF CWA ALONG AND EAST OF THE 
RIVER. MORE STRATUS WAS DEVELOPING FURTHER W OVER CENTRAL IA.  MID 
LEVEL FLOW HAS BECOME NEARLY ZONAL.  TSRA AHEAD OF NORTHERN PLAINS 
S/W HAS BEEN FALLING APART AS IT ENCOUNTERS LOW LEVEL RIDGING OVER 
MN/IA.  SHRA/TSRA ASSOCIATED WITH VERTICALY STACKED LOWER OH VALLEY 
SYSTEM WAS LIMITED TO SERN IL AND MOVING SLOWLY EAST.

MODELS WERE IN FAIR AGREEMENT THROUGH SUNDAY ON THE OVERALL SYNOPTIC 
TRENDS BUT WERE HAVING TROUBLE WITH TIMING AND POSITION OF IMPULSES 
MOVING THROUGH WEAK MID LEVEL FLOW OVER THE SOUTHERN TWO THIRDS OF 
THE COUNTRY.  IN GENERAL...MODELS ALL SUGGEST THAT FRONT CURRENTLY 
OVER THE OHIO VALLEY AND SOUTHERN PLAINS WILL STAY SOUTH OF CWA.  
S/W ENERGY MOVING THROUGH SOUTHERN CANADA WILL DRIVE A WEAK FRONT 
THROUGH THE REGION BY FRIDAY AFTERNOON. HIGH PRESSURE THEN BUILDS 
INTO THE NORTHERN GREAT LAKES BY SUNDAY.

MAIN CONCERN TODAY WILL BE THE IMPACT OF THE EASTERLY LOW LEVEL FLOW 
AND STRATUS ON TEMPS TODAY.  FOCUS WILL THEN SHIFT TO PCPN CHANCES 
INTO THE WEEKEND.   SINCE STRATUS IS ALREADY SPREADING BACK WEST 
OVER THE CWA...WILL ANTICIPATE A CLOUDY MORNING. WE SHOULD HAVE MORE 
OF A CHANCE OF BREAKING OUT OF THE STRATUS BY LATE MORNING OR EARLY 
AFTERNOON THAN YDA.  CI ON TOP OF THE STRATUS SHOULD BE LESS THAN 
YDA WITH OHIO VALLEY SYSTEM MOVING EAST AND CONVECTION TO THE WEST 
DYING OUT EARLY THIS MORNING.  ALSO SHOULD HAVE A LITTLE MORE MIXING 
IN THE WEST AS FLOW BECOMES SOUTHERLY AHEAD OF ADVANCING SURFACE 
TROUGH.  WON'T GO AS COOL AS YDA'S HIGHS...BUT WILL PULL CURRENT 
FCST MAXES BACK ABOUT A CATEGORY...OR NEAR COOLER MAV NUMBERS. 
CURRENT MODEL SOLUTIONS POINTING TO LESS OF A PRECIPITATION THREAT 
THROUGH THE WEEKEND.  BOTH ETA/GFS MOVE A WEAK SURFACE TROF THROUGH 
CWA LATE TONIGHT AND FRIDAY MORNING.  HARD TO GET TO EXCITED ABOUT 
PCPN WITH THIS SYSTEM SINCE BEST DYNAMICS WILL STAY NORTH AND LITTLE 
LOW LEVEL FORCING IS AVAILABLE WITH WEAK SURFACE FLOW OVER REGION.  
WILL KEEP CHANCE POPS GOING LATE THIS AFTERNOON AND THIS EVENING 
WEST OF THE RIVER.  THEN AFTER MIDNIGHT LIMIT POPS TO SOUTHERN CWA 
WITH SURFACE WAVE PROGGED TO MOVE ALONG BOUNDARY TO OUR SOUTH.  
AFTER TONIGHT...HAVE LIMITED POPS THROUGH THE REST OF THE WEEKEND TO 
THE SOUTHERN COUNTIES AND HAVE DOUBTS ABOUT THIS.  MODELS ALL HOLD 
FRONT WELL TO THE SOUTH OF CWA...BUT WITH LOW CONFIDENCE IN MODEL 
SOLUTIONS REGARDING WEAK MID LEVEL WAVES...HATE TO PULL POPS 
ALTOGETHER.  DAY SHIFT CAN REASSES THE PCPN THREAT AND MAKE 
NECESSARY ADJUSTEMENTS.  HAVE ALSO KEPT TEMPS CLOSER TO THE COOLER 
MAV NUMBERS WITH EASTERLY FLOW REESTABLISHING ITSELF SATURDAY AND 
SUNDAY.  

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


$$
DLF