[LeArc] Forecast Discussion : MLI@ 2/27/03 3:07:57 AM

[learc@mailman.qth.net]

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


FXUS63 KDVN 270917
AFDMLI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
315 AM CST THU FEB 27 2003

FLOW REMAINS SPLIT OVER MUCH OF THE WESTERN U.S.. REGION REMAINS 
UNDER INFLUENCE OF A RAHTER BENIGN NORTHERN STREAM WHILE ALL THE 
ACTION REMAINS TO OUR SOUTH. A SUCCESSION OF IMPULSES EJECTING OUT 
OF SOUTHWEST U.S. TROUGH CONTINUES TO KEEP WINTERY WEATHER WELL 
SOUTH OF CWA.  AT 06Z HIGH PRESSURE WAS CENTERED OVER SOUTHERN 
ONTARIO WITH RIDGING EXTENDING WEST THROUGH IA.  LITTLE IN THE WAY 
OF SIGNIFICANT WEATHER NOTED WITH COLD FRONT OVER THE NORTHERN 
PLAINS EARLY THIS MORNING.  SOUTHERN STREAM  SYSTEM JUST COMING 
TOGETHER OVER THE SOUTHERN ROCKIES...WAS SPREADING SNOW ACROSS SWRN 
KS AND NRN OK.  

MODEL INITIALIZATION LOOKED REASONABLE AT 00Z WITH NO MAJOR 
DESCRPANCIES NOTED.  ETA/GFS SOLUTIONS ARE SIMILAR INTO FRIDAY 
TAKING SYSTEM OVER SOUTHERN ROCKIES QUICKLY EAST TODAY AND TONIGHT.  
SYSTEM DROPPING SOUTH ALONG THE CA COAST THIS MORNING EJECTS OUT OF 
TROUGH LATE TODAY...AND REACHES THE MID MISSISSIPPI VALLEY BY EARLY 
SATURDAY. 

MAIN CONCERN TODAY WILL BE PCPN CHANCES SOUTH LATE THIS AFTERNOON 
AND THIS EVENING THEN PRECIPITATION CHANCES AGAIN FRIDAY NIGHT INTO 
SATURDAY.   GFS QPF FIELDS LOOK REASONABLE BY 12Z WITH RESPECT TO SN 
DEVELOPING OVER SOUTHERN PLAINS.  GFS LIFTS PCPN SHIELD NORTH TO 
NORTHERN MO BY 18Z.  CONFLUENT FLOW OVER CENTRAL U.S. THEN LIMITS 
NORTHWARD PROGRESSION OF THE PCPN WITH GFS ONLY 
SHOWING...LIGHT...QPF MAKING IT INTO SRN FOURTH OF CWA. ETA KEEPS 
PCPN OVER NORTHERN MO.  FORCING SUPPORTS THE MORE SOUTHERN 
SOLUTION.  MENTION OF FLURRIES THIS EVENING IN THE FAR SOUTH STILL 
LOOKS REASONABLE.  NEXT SYSTEM TO IMPACT REGION IS CURRENTLY 
DROPPING SOUTH ALONG THE CA COAST...WITH WATER VAPOR IMAGERY 
SUGGESTING A STRONG SYSTEM.  MODELS ALL MOVE H5 TROUGH THROUGH THE 
PLAINS AND INTO THE MID MISSISSIPPI VALLEY BY LATE SATURDAY NIGHT.  
GFS MAINTAINS A STRONGER TROUGH THAN THE ETA AND THIS LOOKS 
REASONABLE BASED APPARENT STRENGTH OF SYSTEM.  WILL CONTINUE LOW 
CHANCE POPS FOR -SN ALREADY IN FORECAST FOR THE CENTRAL AND SOUTHERN 
SECTIONS. FLURRIES AT BEST EXPECTED OVER NORTHERN CWA.

TEMPS THE NEXT SEVERAL DAYS WILL BE DEPENDENT ON THE EXTENT OF CLOUD 
COVER.  SURFACE RIDGE WILL HOLD IN PLACE OVER CENTRAL/SOUTHERN CWA 
THROUGH FRIDAY...KEEPING SURFACE WINDS LIGHT.  CLOUD COVER WILL BE 
MOST EXTENSIVE OVER THE SOUTHERN HALF OF THE CWA AND WILL LIMIT 
DIURNAL RANGE.  WILL LEAN TOWARD COOLER MAV NUMBERS IN THE SOUTH. 
WARMER MET NUMBERS IN THE NORTH MORE REASONABLE WITH LATE FEB SUN 
PROVIDING ENOUGH HEATING TO SEND READINGS INTO THE LOWER 30S.

LOOKS LIKE MODELS ARE HAVING A HARD TIME WITH SOUTHERN STREAM FLOW 
EARLY NEXT WEEK.  27/00Z GFS SHOWS RIDGING OVER SOUTHWEST U.S. WHERE 
THE 26/00Z RUN WAS SHOWING STRONG TROUGH.  27/00 UKMET ALSO SHOWING 
SOME RIDGING IN THE SOUTHWEST...BUT NOT AS STRONG AS THE GFS.  WILL 
LEAVE EXTENDED AS IS AND SEE IF 12Z RUN PROVIDES ANY CONTINUITY.
 
.DVN...
IA...NONE.
IL...NONE.
MO...NONE.

$$
DLF