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Tropical Storm KYLE (Text)

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TROPICAL STORM KYLE DISCUSSION NUMBER   3
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL112008
500 AM EDT FRI SEP 26 2008
 
AN AIR FORCE RESERVE RECON AIRCRAFT FOUND 850 MB SLIGHT-LEVEL WINDS
OF 63 KT IN THE NORTHEAST QUADRANT...WHICH IS ROUGHLY EQUAL TO A
47-KT SURFACE WIND. HOWEVER...SFMR SURFACE WINDS OF 50 AND 53 KT
WERE MEASURED BENEATH THE MAXIMUM FLIGHT-LEVEL WINDS...SO A BLEND
OF THESE VALUES YIELDS AN AVERAGE SURFACE WIND SPEED ESTIMATE OF 50
KT. THIS WIND SPEED ESTIMATE IS ALSO CONSISTENT WITH THE
PRESSURE-WIND RELATIONSHIP ASSOCIATED WITH THE 997 MB CENTRAL
PRESSURE THAT WAS MEASURED BY A DROPSONDE. 
 
RECENT AIRCRAFT AND SATELLITE FIXES INDICATE THE MOTION IS NOW
350/10 KT. AS HIGH PRESSURE/RIDGING CONTINUES TO BUILD TO THE
NORTHEAST OF KYLE...THE CYCLONE IS EXPECTED TO TURN MORE TOWARD THE
NORTH-NORTHWEST OVER THE NEXT 24-36 HOURS. AFTER THAT...A TURN BACK
TOWARD THE NORTH WITH EVENTUAL RECURVATURE TO THE NORTHEAST IS
FORECAST BY ALL OF THE GLOBAL MODELS. HOWEVER...THE FORECAST TRACK
IS NOT AS STRAIGHTFORWARD AS THAT. ALTHOUGH THE MODELS ARE TIGHTLY
CLUSTERED THROUGH 72 HOURS...THERE REMAINS ENOUGH UNCERTAINTY IN
EXACTLY WHEN AND WHERE THE POINT OF RECURVATURE WILL OCCUR. 00Z
UPPER-AIR HEIGHT DATA FROM BERMUDA WAS IN ERROR TO DUE A BAD
BASELINE...BUT THE 00Z MODELS APPEAR TO HAVE FILTERED OUT THIS
ERRONEOUS MASS FIELD DATA. HOWEVER...THE WIND DATA WAS GOOD...AND
THE BACKING WIND FLOW FROM SOUTH TO SOUTHEAST INDICATES THAT
RIDGING COMING IN FROM THE NORTHEAST IS A LITTLE STRONGER THAN THE
MODELS HAVE BEEN FORECASTING. ALSO...ALL OF THE GLOBAL AND REGIONAL
MODELS ARE FORECASTING AN OMEGA BLOCKING PATTERN TO DEVELOP OVER
THE CENTRAL ATLANTIC BETWEEN THE LOW CURRENTLY OVER SOUTHEASTERN
U.S. AND A MUCH LARGER LOW FORECAST TO DEVELOP WEST OF THE AZORES.
SINCE OMEGA BLOCKS ARE GENERALLY STABLE PATTERNS...THE MODELS MAY
BE BREAKING DOWN THE NORTHERN PORTION OF THE RIDGE SOUTH OF NOVA
SCOTIA TOO QUICKLY...WHICH WOULD RESULT IN PREMATURE RECURVATURE BY
THE MODELS. AS A RESULT...THE OFFICIAL TRACK FORECAST HAS BEEN
SHIFTED TO THE WEST OF THE PREVIOUS TRACK...AND IS CLOSE TO THE NHC
MODEL CONSENSUS. SUBSEQUENT FORECAST TRACKS MAY ALSO HAVE TO BE
SHIFTED A LITTLE FARTHER WEST AND CLOSER TO THE U.S. CAPE COD AREA
SIMILAR TO THE 00Z GFS...GFDL...HWRF...NOGAPS...AND CANADIAN MODEL
RUNS. ONLY THE UKMET AND ECMWF KEEP KYLE WELL TO THE EAST OF THE
NORTHEASTERN U.S.

SHEARED DEEP CONVECTION WITH CLOUD TOPS COLDER THAN -80C IN THE
NORTHEAST QUADRANT HAVE STARTED TO DEVELOP CLOSER TO THE LOW-LEVEL
CENTER. ONCE KYLE TURNS MORE TOWARD THE NORTH-NORTHWEST...THE
VERTICAL CIRCULATIONS ARE EXPECTED TO BECOME VERTICALLY STACKED AND
MORE ALIGNED WITH THE DEEP LAYER FLOW. THIS SHOULD ALLOW FOR STEADY
INTENSIFICATION TO OCCUR OVER RELATIVELY WARM WATER UNTIL KYLE
REACHES THE NORTH WALL OF THE GULFSTREAM IN ABOUT 48 HOURS.
ALTHOUGH MUCH COOLER WATER LIES NORTH OF GULFSTREAM...THE FAST
FORWARD SPEED OF THE CYCLONE SHOULD INHIBIT ANY SIGNIFICANT
DECREASE IN INTENSITY UNTIL LANDFALL OCCURS. THE OFFICIAL INTENSITY
FORECAST IS SIMILAR TO THE PREVIOUS FORECAST...AND IS CLOSE TO THE
SHIPS AND GFDL MODELS...BUT NOT AS STRONG AS THE HWRF MODEL.
 
INTERESTS IN EASTERN NEW ENGLAND AND THE CANADIAN MARITIMES SHOULD
CLOSELY MONITOR THE PROGRESS OF KYLE.
  
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      26/0900Z 25.6N  68.3W    50 KT
 12HR VT     26/1800Z 27.5N  68.8W    55 KT
 24HR VT     27/0600Z 30.5N  69.5W    60 KT
 36HR VT     27/1800Z 34.0N  69.8W    65 KT
 48HR VT     28/0600Z 38.5N  69.0W    70 KT
 72HR VT     29/0600Z 45.7N  66.3W    60 KT...EXTRATROPICAL INLAND
 96HR VT     30/0600Z 51.0N  61.0W    50 KT...EXTRATROPICAL INLAND
120HR VT     01/0600Z...ABSORBED BY FRONTAL SYSTEM
 
$$
FORECASTER STEWART
 
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