FXUS61 KBGM 091035
AFDBGM

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BINGHAMTON NY
635 AM EDT WED APR 9 2003

WILL BE UPDATING ZONES TO DROP ADVISORY.  PRECIP SHIELD NOT REALLY 
MOVING ANY FARTHER NORTHWARD...AND THOUGH IT MAY NUDGE A LITTLE 
FURTHER...WOULD EXPECT ONLY SHRA AND SOME ISOLATED SHFZRA ON THE 
HIGH TERRAIN THROUGH 13Z-14Z.  AFTER THAT...TEMPS SHOULD BE ABOVE 
FREEZING EVERYWHERE.  WILL BE DROPPING POPS ACROSS THIS REGION AS 
WELL.  NO OTHER CHANGES.   MJC

----- 329 AM DISCUSSION -----

BIG PICTURE...AMPLIFYING 500 MB RIDGE OVER CENTRAL N AMERICA WILL 
HELP ERN US TROUGH CLOSE OFF OVER SERN STATES.  CUTOFF IS THEN 
FORECAST TO SLOWLY TRACK NE BEFORE GETTING CAUGHT UP IN 500 MB FLOW 
AGAIN.  AS A RESULT COLD AIR OVER ERN CANADA WILL RETREAT POLEWARD.

TODAY...QUESTION OF THE DAY IS HOW FAR NORTH INTO NERN PA DOES THE 
PRECIP GET THIS MORNING...AND WHAT WILL BE THE STATE OF THE PRECIP.  
PRECIP TYPE FIRST...ETA BUFKIT SOUNDINGS INDICATE FROZEN PRECIP AT 
KAVP...HOWEVER...TEMPS THERE ARE RUNNING A FEW DEGREES F ABOVE ETA 
FORECASTS...AND MAV KEEPS TEMPS ABOVE FREEZING.  DEW POINTS ALSO 
ABOVE MODEL FORECAST VALUES AS WELL.  SO...WILL GO WITH LIQUID 
PRECIP...EXCEPT FREEZING ON THE HILLS.  ON TO QPF AND AREAL EXTENT 
OF PRECIP...NOT TOO MUCH IN THE ANY SORT OF FORCING...DYNAMIC OR 
THERMODYNAMIC...AND OMEGA FIELDS ARE WEAK.  500 MB DOES PASS TO THE 
SOUTH...AND SOME ISENTROPIC LIFT IS EVIDENT EARLY...BUT FADES AFTER 
09Z.  LATEST RADAR TRENDS...HOWEVER...DO SHOW SOME PRECIP ADVANCING 
NORTHWARD ACROSS CENTRAL PA.  STILL...HARD TO FIND A REASON WHY 
ANYTHING OTHER THAN A FEW HUNDREDTHS OF PRECIP WOULD MAKE IT INTO 
THE CWA.  ANY PRECIP SHOULD BE OVER BY MIDDAY...BUT MAY SEE SOME SN 
MIXING IN BEFORE IT ENDS...AS COOLER AIR MOVES IN ALOFT ONCE LOW 
TRACKS OFF TO THE EAST.  SINCE THE ADVISORY IS UP...WILL NOT DROP IT 
ATTM...BUT WILL SHIFT FOCUS TO HIGHER TERRAIN.  FOR REST OF 
CWA...WILL REMOVE PRECIP FROM ALL BUT SRN ZONES FOR TODAY...BUT AS 
ENE FLOW CONTINUES...WILL KEEP OVC.

TONIGHT-THU...RIDGE WILL DEVELOP OVER REGION PUTTING AN END TO 
EASTERLY FLOW.  ALTHOUGH WITH LITTLE MID LAYER FLOW MIGHT TAKE A 
LITTLE TIME FOR LOW LEVEL MOISTURE TO CLEAR TONIGHT.  FAIRLY GOOD 
SUBSIDENCE IN PLACE THU AS CWA WILL BENEFIT FROM BEING BENEATH LEFT 
ENTRY REGION OF JET...AND WE SHOULD SEE A M/SUNNY DAY AS THE ONLY 
CLOUDS MAY BE CIRRUS DERIVED FROM CLOSED LOW MOISTURE TO OUR SOUTH.  
CLOUDS INCREASE THU NIGHT AS SFC LOW APPROACHES.

FRIDAY...COASTAL SYSTEM ASSOCIATED WITH FILLING 500 MB CLOSED LOW 
WILL TRACK NNE FRIDAY INTO FRI NIGHT.  BOTH ETA/GFS SUGGEST 
DEFORMATION ZONES SET UP ACROSS THE CWA ON FRIDAY...WITH RAIN 
STARTING EARLY.  OREINTATION OF PRECIP BANDS DIFFER BETWEEN THE 
MODELS...BUT QPF NOT THAT FAR OFF.  A PERIOD OF HEAVY RAIN MAY BE 
POSSIBLE ON FRIDAY...AS FILLING CLOSED SYSTEMS CAN PRODUCE SOME 
HEAVY PRECIP ON THEIR PERIPHERIES...HOWEVER...THIS SYSTEM LOOKS LIKE 
IT WILL BE PROGRESSIVE ENOUGH BY THIS TIME THAT ANY HEAVY RAIN WILL 
NOT LAST LONG.  SFC LOW MOVES OUT FRI NIGHT...BUT 500 MB LOW WILL BE 
LINGERING INTO SAT...SO CHC POPS FOR SHRA WILL LINGER IN THE 
FORECAST AS WELL.

.BGM...NONE

CEMPA