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FXUS02 KWBC 061804
PMDEPD
EXTENDED FORECAST DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
204 PM EDT FRI JUN 06 2008
VALID 12Z MON JUN 09 2008 - 12Z FRI JUN 13 2008
THE 00Z DETERMINISTIC ECMWF KEEPS THE LOWEST HEIGHTS ALONG THE
CANADIAN BORDER DURING THE PERIOD...WHICH FITS CLIMATOLOGY MUCH
BETTER THAN THE GFS...GEM GLOBAL...AND UKMET...WHICH INDICATE AN
UNSEASONABLY DEEP VORTEX OVER THE NORTHERN INTERMOUNTAIN REGION AS
EARLY AS DAY 4. 00Z GFS SOLUTION WITH BOTH ITS WRN TROF NOT
SUPPORTED BY GFS ENS MEANS NOR ENSEMBLE REMOP WHICH ORIENTS THE
TROF WITH A MORE POSITIVE TILT.
THE ECWMF IS SUPPORTED BY ITS MOST RECENT ENSEMBLE MEAN AT LEAST
THROUGH DAY 5...AND WILL BE USED TO CREATE THE PRELIMINARY FRONTS
AND PRESSURES. THERE IS SOME QUESTION AS TO HOW AMPLIFIED THE
DOWNSTREAM TROUGH GETS OVER THE NORTHEAST AND ADJACENT ATLANTIC
OCEAN LATE IN THE PERIOD...WITH THE 00Z UKMET AND 12Z/05 ECMWF
MEAN THE LEAST AGGRESSIVE OF THE RECENT GUIDANCE AS IS GFS ENS
MEAN AND GFS ENS REMOP WHICH INDICATES HIGH CONFIDENCE AND
PREDICTABILTY HOLDING ON TO THE STRONG ERN CONUS RIDGE. WILL
TEMPER THE ECMWF TOWARD THESE CLIMATOLOGICALLY REASONABLE
SOLUTIONS INCORPORATING 00Z ECMWF ENS MEAN BY MID TO LATE PERIOD.
12Z GFS HAS ELIMINATED ITS PROGRESSIVE SHORTWAVE ACROSS THE GREAT
LAKES REGION AND NORTHEAST
TUES-WED AS HTS ARE 60-120 MTRS HIGHER AT H500. THE 00Z SOLUTION
WAS NIXED BY HPC AS PER ENSEMBLES AND ENS REMOP PREFERING TO KEEP
THE STRONG ERN CONUS RIDGE. WWD THE DEEPER VORTEX OF GFS REMAINS A
POSSIBILITY BUT IT ALSO IS 60-90 MTRS HIGHER OVER THE NRN PLAINS
TUES-THURS. CMC HAS ALSO DAMPENED THIS SHORTWAVE.
MINOR CHANGES TO AFTN FINALS FROM EARLIER PRELIMS AT THE
SFC..MAINLY LESS FRONTAL PUSH SWD TUES THRU THE MID MS/LOWER OH
VALLEY. MID LEVEL AND POTENTIAL TEMP FOR THE PAC NW AS ECMWF HTS
ARE TOO HIGH DAYS 3-4 WITH A TENDENCY FOR IT TO BE TOO FAR NORTH
WITH THE INCOMING SHORTWAVE.
SOME RELIEF TO THE ERN CONUS HEAT WAVE EXPECTED LATE WEEK INTO
NEXT WEEKEND AS THE CONUS FLOW PATTERN BECOMES MORE ZONAL. CENTRAL
TO NRN PLAINS WILL REMAIN THE FOCUS OF HVY RAINFALL THIS PERIOD
WITH SUBTROPICAL TO MID LATITUDE RIDGING DOMINATING ERN CONUS AND
THE WEST ATLC AND A MEAN TROF PERISTING OVER WRN U.S.
CISCO/ROSENSTEIN
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