[LeArc] Forecast Discussion : MLI@ 2/26/03 3:27:53 PM

[learc@mailman.qth.net]

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


FXUS63 KDVN 262135
AFDMLI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
335 PM CST WED FEB 26 2003

SURFACE HIGH FINALLY PULLING OFF TO THE EAST...THOUGH RETURN FLOW 
HAS NOT YET KICKED IN DUE TO SURFACE RIDGE STILL SITTING OVER THE 
AREA.  WEAK...BUT ENOUGH TO KEEP SOUTHERLY FLOW FROM KICKING IN.  
UPPER AIR ANALYSIS AND SATELLITE INCIDATING THAT YET ANOTHER SYSTEM 
IS BREWING OVER THE 4 CORNERS AREA...WHICH AS IT MOVES OUT OF THE 
ROCKIES WILL HAVE A NICE 850MB THERMAL GRADIENT TO WORK WITH.  THIS 
SHOULD HELP TO DRAW IT TO THE SOUTH...YET AGAIN.  THIS SYSTEM 
APPEARS TO BE KIND OF WEAK ON THE UA ANALYSIS WHEN COMPARED TO 
SATELLITE IMAGERY.

12Z MODELS HAVE MISSED OUT ON THE STRENGTH OF THE LOW OVER THE 
4CORNERS AREA...AND ARE A LITTLE WEAK ON IT.  HAVE CONCERNS THAT IT 
WILL COME OUT OF THE ROCKIES FARTHER SOUTH AND SLOWER THAN MODELS 
CURRENTLY DEPICT IT.  HAVE NOT YET MADE ANY CHANGES TO REFLECT THIS 
THINKING...BUT WOULD NOT BE SURPRISED TO SEE THIS CHANGE IN A LATER 
PACKAGE.  ALSO...THERE HAS BE QUITE A BIT OF SEE-SAWING ON THE TRACK 
OF THESE WAVES AS THE COME OUT OF THE ROCKIES.  THE 00Z RUN OF BOTH 
ETA AND AVN WAS BRINGING PRECIP ACROSS MUCH OF CWA FRIDAY NIGHT.  
HOWEVER...LIKE ON YESTERDAYS 12Z RUN...THIS MORNINGS RUN DRY AGAIN 
FOR THE MOST PART.  HAVE A STRONG DISLIKE TO GIVING MIXED 
SIGNALS...SO WILL LEAVE SNOW IN FORECAST FOR NOW...BUT KEEP POPS 
LOW...ESPECIALLY NORTHEAST.  WILL BE REMOVING SNOW FROM SATURDAY 
NIGHT.  ONLY OTHER CHANCE OF PRECIP IS A FEW FLURRIES THAT I WILL 
THROW IN FOR THURSDAY NIGHT IN THE FAR SOUTH.  

TEMPS TONIGHT A LITTLE ON THE TRICKY SIDE...EXPECT THAT WITH CURRENT 
TEMPERATURES SIGNIFICANTLY WARMER THAN YESTERDAY AT THIS 
TIME...COULD BE 10 TO 15 DEGREES WARMER THAN THIS MORNING.  UPSTREAM 
LOW TEMPS FROM THIS MORNING RANGED FROM 10 TO 15.  HOWEVER...WITH 
CLEAR SKIES EXPECTED TONIGHT WILL BE COOLER THAN THAT.  HAVE DECIDED 
TO GO AROUND MAV GUIDANCE...JUST BELOW GOING FORECAST.  BY THURSDAY 
GUIDANCE TEMPS LOOK A LITTLE ON THE WARM SIDE...WITH INCREASING 
CLOUDS AND NORTHEAST FLOW.  HAVE GONE NO WARMER THAN LOW 30S IN THE 
FAR SOUTH...BUT TAPER TO UPPER 20S FAR NORTH.  HAVE GONE WITH 
SLIGHTLY COOLER THAN GUIDANCE VALUES FOR THURSDAY NIGHT THROUGH 
SATURDAY NIGHT.

EXTENDED...SUNDAY-WEDNESDAY
SOME INTERESTING DIFFERENCES BETWEEN THE 00Z AND 12Z GFS WHICH ARE 
OF IMPORT FOR THE CWA.  00Z GFS MOVES INTO A LARGE SCALE CYLCONIC 
FLOW FOR WEEKEND AND EARLY NEXT WEEK...WITH A WEAKLY DISCERNABLE 
NORTHERN AND SOUTHERN STREAM.  THE ECMWF PICKS UP A MORE ACTIVE 
FLOW...WHICH IS BACKED UP BY THE 12Z GFS RUN.  HAVE DECIDED TO GO 
WITH THIS MORE ACTIVE FLOW...WHICH BRINGS A SERIES OF SHORT WAVES 
ACROSS THE MID WEST THROUGH THIS PERIOD.  WILL PULL POPS FROM MONDAY 
AS THIS SCENARIO INDICATES WE WILL BE BETWEEN SYSTEMS...BUT POPS FOR 
SUNDAY AND AGAIN ON TUESDAY AND WEDNESDAY.

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

$$

LRE