979
FXUS02 KWBC 101824
PMDEPD
EXTENDED FORECAST DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
223 PM EDT THU JUL 10 2008
VALID 12Z SUN JUL 13 2008 - 12Z THU JUL 17 2008
MEDIUM RANGE MODELS ARE AGAIN IN GOOD AGREEMENT OVER CONUS AND
NOAM WITH A VERY STRONG
CANADIAN PLAINS MID LEVEL LOW THAT DROPS SEWD FORMING AN ANOMALOUS
TROF OVER THE ERN CONUS WHILE UPSTREAM A MUCH WEAKER POSITIVELY
ORIENTED ERN PAC TROF MOVES TO THE PAC NW AND ADJACENT CANADA
LEAVING AN ANCHORED MEAN TROF. FLAT TO MODERTAELY AMPLIFIED
RIDGING WILL PREVAIL FROM THE ROCKIES TO THE MS VALLEY.
WRN AND NRN ATLC DIFFERENCES OCCUR THIS PERIOD AFFECTING THE PATH
OF HURRICANE BERTHA AND ITS TRANSFORMATION TO A BAROCLINIC STORM.
NEARLY ALL GUIDANCE TAKES BERTHA NWD ALONG OR JUST WEST OF 60W
WITH 00Z GFS/GFDL/HWRF/12Z CMC ALL FASTER AND A SOMEWHAT PREFERRED
SOLUTION BY NHC/TPC. ECMWF AND CMC/ NEW 12Z GFS COMPLICATE MATTERS
EITHER BY DEVELOPING A LARGE DEEP CUT OFF LOW IN THE NE ATLC THAT
RETROGRADES WWD OR JUST LEAVING BERTHA WITH A VERY SLOW NWD TRACK
AS PER 12Z GFS. THE NE ATLC CUTOFF SOLUTIONS APPEAR TO BE
OVERDONE. MAIN ATLC RESULT IS A MUCH SLOWER PROGRESSION OF BERTHA
WITH 12Z GFS/00Z ECMWF AND 00Z CMC. ITS ONLY AFFECT OVER CONUS AND
THE W ATLC NO MATTER WHICH SOLUTION IS RIGHT WILL BE IN THE FORM
OF ONSHORE SWELL THAT WILL AFFECT THE EAST COAST THRU AT LEAST 5
DAYS AND VERY POSSIBLY LONGER. SEE TPC/OPC DISCUSSIONS AND
ADVISORIES.
ELSEWHERE...EXPECT SOME ENERGY TO CUT ACROSS THE PACIFIC
NORTHWEST...BUT NOT ENOUGH TO TAKE A SIGNIFICANT BITE OUT OF THE
HEAT OVER THE INTERIOR. THERE WILL PROBABLY BE ENOUGH WESTERLY
COMPONENT TO THE DEEP LEVEL FLOW OVER THE SOUTHWEST TO DIRECT THE
MONSOONAL ENERGY TO THE EAST OF ITS MEAN CLIMATOLOGICAL AXIS.
...EASTERN CONUS
DEEP TROF ABOUT 3 STANDARD DEVIATIONS BELOW NORMAL AT H500 WILL
MOVE ACROSS THE GREAT LAKES REGION SUNDAY AND DROPPING SEWD OVER
THE ERN SEABOARD BEFORE ITS EXITS AND HTS RISE TO NEAR NORMAL LATE
NEXT WEEK. THIS WILL BRING COOLER CONDS INTIALLY BEHIND THE FRONT
BUT ABOUT AVG TO NORMAL TEMPS WILL PREVAIL REBOUNDING TO ABOVE AVG
CONDS AT HTS RISE LATE WEEK. INCREASING CHANCE OF BENEFICIAL RAINS
OVER SERN CONUS INCLUDING FL THIS PERIOD AHEAD OF AND ALONG THE
COLD FRONT MON AND TUES. SMALL SHALLOW SYMETRIC WARM CORE LOW
CYCLOGENESIS STILL REMAINS POSSIBLE OFF THE NC COAST AS SEEN BY
ECMWF AND ESPECIALLY BOTH CMC RUNS SAT AND SUN. ONSHORE COASTAL
SWELL FROM BERTHA WILL AFFECT MOST OF THE EAST COAST THIS PERIOD.
SEE OPC PRODUCTS.
..WEST
WRN CONUS TEMPS REMAIN HOT THRU DAY 3 BUT FALLING HTS WILL COOL
THE REGION TO NORMAL OR SLIGHTLY BELOW AFTER DAY 4.
...PLAINS..
WARMING CONDS AS RIDGING AND INCREASING H850 TEMPS ANOMALIES PUSH
EAST AND NEWD MON-WED.
...TROPICS
SEE NHC/OPC ADVISORIES AND PRODUCTS FOR BERTHA. ELSW THE LONGER
TERM MEAN PATTERN ACROSS THE ATLC FROM THE COAST OF AFRICA INTO
NRN AND CENTRAL AMERICA IS FAVORABLE FOR A CONTD WRLY TRACK OF ANY
SYSTEMS EXITING AFRICA. LONGER TERM SHEAR FORECASTS OF ECMWF/GFS
ENS MEANS ALSO ARE FAVORABLE. SEVERAL MODELS INCLUDING GFS/ECMWF
TAKE A NUMBER OF WAVES WWD TOWARDS THE END OF THE FORECAST PERIOD
INTO THE LONGER TERM. MONITOR NHC OUTLOOKS.
CISCO/ROSENSTEIN
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