Tropical Storm Kyle NHC 5 AM Discussion

AIR FORCE RECON REPORTS INDICATE LITTLE CHANGE IN THE STRENGTH AND STRUCTURE OF KYLE DURING THE PAST 6 HOURS. THERE WERE TWO REPORTS OF 70 KT AT 850 MB FLIGHT-LEVEL IN THE NORTHEAST QUADRANT...WHICH WOULD TYPICALLY CORRESPOND TO ABOUT 55 KT SURFACE WINDS. SFMR WINDS IN THAT SAME AREA ALSO ONLY SUPPORT ABOUT 55 KT. HOWEVER...THE MAXIMUM FLIGHT-LEVEL WINDS OCCURRED ABOUT 30 NMI NORTHWEST OF THE MOST INTENSE CONVECTION...SO IT IS POSSIBLE THAT STRONGER WINDS MAY HAVE BEEN MISSED ALONG THE NORTHEAST FLIGHT LEG. THE HIGHER LATITUDE AND INCREASING PRESSURE GRADIENT TO THE EAST ALSO SUPPORTS KEEPING THE INTENSITY A LITTLE HIGHER THAN WHAT THE STANDARD PRESSURE-WIND RELATIONSHIP FOR A 996 MB PRESSURE WOULD SUPPORT. KYLE HAS MADE A SHORT TERM JOG TO THE NORTHWEST...OR 330 DEGREES AS A MID- TO UPPER-LEVEL SHORTWAVE TROUGH HAS PASSED TO THE NORTHWEST OF THE CYCLONE. HOWEVER...A 9-HOUR AVERAGE MOTION YIELDS 345/14... AND THAT IS WHAT WAS USED FOR THIS ADVISORY. KYLE REMAINS WEDGED BETWEEN A LARGE DEEP-LAYER RIDGE TO THE EAST AND A DEEP-LAYER BUT WEAKENING LOW TO THE WEST OVER WESTERN NORTH CAROLINA. THE COMBINED SOUTHERLY TO SOUTH-SOUTHEASTERLY FLOW BETWEEN THESE TWO SYSTEMS IS EXPECTED TO GRADUALLY ACCELERATE KYLE NORTHWARD TODAY AND THEN NORTH-NORTHEASTWARD ON SUNDAY. ALTHOUGH THE GLOBAL MODELS REMAIN TIGHTLY CLUSTERED...THE VARIOUS SURFACE TRACKS HAVE SHIFTED SLIGHTLY WESTWARD DUE TO THE RIDGE TO THE EAST BEING STRONGER THAN THE MODELS HAVE BEEN FORECASTING OVER THE PAST 24 HOURS. HOWEVER... SOME UNCERTAINTY STILL REMAINS ON THE EXACT TIME AND LOCATION OF RECURVATURE OF KYLE TO THE NORTHEAST. IF THE EXPECTED TURN TOWARD THE NORTH-NORTHEAST IS DELAYED BY JUST 6 HOURS ...THEN KYLE WOULD PASS CLOSER TO CAPE COD THAN INDICATED BY THE OFFICIAL FORECAST. WATER VAPOR IMAGERY INDICATES THE RIDGE TO THE EAST OF KYLE CONTINUES TO AMPLIFY NORTHWARD OVER THE NORTHEASTERN U.S. AND THE CANADIAN MARITIMES REGION. IF THIS TREND CONTINUES IN CONTRAST TO WHAT THE MODELS ARE FORECASTING...THEN SUBSEQUENT FORECAST TRACKS WILL HAVE TO BE SHIFTED WESTWARD AND CLOSER TO EASTERN NEW ENGLAND. AS A RESULT...WATCHES OR WARNINGS MAY BE REQUIRED FOR PORTIONS OF THE COASTAL NEW ENGLAND AND CANADIAN MARITIMES REGION LATER THIS MORNING. THE OVERALL CONVECTIVE PATTERN HAS IMPROVED...EVEN THOUGH CLOUD TOPS HAVE WARMED. ONE MID- TO UPPER-LEVEL SHORTWAVE THAT PASSED TO THE NORTHWEST OF KYLE LATE YESTERDAY ALLOWED THE CYCLONE TO BRIEFLY INTENSIFY. ANOTHER SHORTWAVE TROUGH LOCATED ALONG 30N LATITUDE IS LIFTING NORTHWARD AS NOTED IN WATER VAPOR IMAGERY. ONCE THIS SYSTEM PASSES TO THE NORTHWEST OF KYLE AND RELIEVES PRESSURE ON THE WEST SIDE OF THE CYCLONE...AN INTENSIFICATION PHASE SHOULD RESUME AND KYLE IS EXPECTED BECOME A CATEGORY 1 HURRICANE LATER TODAY. THE OFFICIAL INTENSITY FORECAST IS ONLY SLIGHTLY HIGHER THAN THE PREVIOUS FORECAST...AND IS A BLEND OF THE ICON...SHIPS...AND THE GFDL MODELS.

FORECAST POSITIONS AND MAX WINDS INITIAL 27/0900Z 30.5N 69.4W 60 KT 12HR VT 27/1800Z 33.0N 69.7W 65 KT 24HR VT 28/0600Z 36.8N 69.4W 70 KT 36HR VT 28/1800Z 41.0N 68.4W 70 KT 48HR VT 29/0600Z 44.9N 66.7W 60 KT...BECOMING EXTRATROPICAL 72HR VT 30/0600Z 50.5N 64.0W 40 KT...EXTRATROPICAL INLAND 96HR VT 01/0600Z...ABSORBED BY FRONTAL SYSTEM

Tropical Storm Kyle NHC Discussion 5 PM

REPORTS FROM AIR FORCE AND NOAA RESERVE HURRICANE HUNTER AIRCRAFTINDICATE THAT KYLE IS SOMEWHAT DISORGANIZED THIS AFTERNOON...WITHTHE FLIGHT-LEVEL CENTERS AT 850 MB AND 700 MB DISPLACED TO THENORTH OR NORTHEAST OF THE SURFACE CENTER BY 15-20 KT OF WESTERLYVERTICAL WIND SHEAR. THE CENTRAL PRESSURE HAS RISEN TO 1003MB...AND THE CONVECTIVE PATTERN HAS BECOME ELONGATED NORTH-NORTHWEST TO SOUTH-SOUTHEAST IN SATELLITE IMAGERY. THE AIR FORCEAIRCRAFT REPORTED 56 KT FLIGHT-LEVEL WINDS AT 850 MB...WITH SFMRWINDS OF 45-48 KT IN THE NORTHEAST QUADRANT. BASED ON THIS...THEINITIAL INTENSITY REMAINS 50 KT.AFTER A NUDGE TO THE LEFT THIS MORNING...KYLE HAS MADE A NUDGE TOTHE RIGHT THIS AFTERNOON. THE 12 HR MOTION AND ADVISORY MOTION IS345/11...BUT THE SHORT-TERM MOTION IS ALMOST DUE NORTH. KYLEREMAINS ON THE SOUTHWEST SIDE OF A BUILDING RIDGE OVER THE CENTRALATLANTIC...AND SOON SHOULD PASS BETWEEN THE RIDGE AND A DEEP-LAYERLOW PRESSURE AREA OVER THE EASTERN UNITED STATES. THIS PATTERNSHOULD STEER KYLE GENERALLY NORTH-NORTHWESTWARD AND NORTHWARD FORTHE NEXT 24-36 HR. AFTER THAT...THE GUIDANCE FORECASTS KYLE TOTURN MORE TOWARD THE NORTH-NORTHEAST AS IT APPROACHES THE MAINBRANCH OF THE WESTERLIES AND THE NORTHERN END OF THE ATLANTICRIDGE. THE MODEL GUIDANCE HAS SHIFTED A LITTLE TO THE RIGHT TOWARDWESTERN NOVA SCOTIA OVER THE PAST 6 HOURS...WITH MOST OF GUIDANCENOW SHOWING A SLIGHTLY SLOWER FORWARD MOTION THAN PREVIOUSLY. BASED ON THE NEW GUIDANCE AND THE INITIAL POSITION/MOTION...THE NEWFORECAST TRACK IS SHIFTED A LITTLE TO THE EAST OF THE PREVIOUSTRACK. HOWEVER...IT LIES ALONG THE WESTERN EDGE OF THE MODELCONSENSUS.IF ANYTHING...THE INTENSITY FORECAST HAS BECOME MORE COMPLEX THAN ITWAS 6 HOURS AGO. THE CURRENT SHEAR MAY DECREASE SOMEWHAT OVER THENEXT 24 HOURS...WHICH WOULD ALLOW KYLE TO GRADUALLY INTENSIFY. AFTER THAT...KYLE IS FORECAST TO ENCOUNTER STRONG...BUTDIVERGENT...UPPER-LEVEL SOUTHWESTERLY FLOW....WITH THE RESULTINGSHEAR TRYING TO WEAKEN THE CYCLONE AND THE DIVERGENCE TRYING TOSTRENGTHEN IT. A NEW COMPLICATION IS A COLD AIR MASS APPROACHINGKYLE FROM THE EAST...WHICH IF IT REACHES THE CYCLONE COULD CAUSEWEAKENING OR A FASTER EXTRATROPICAL TRANSITION. DESPITE THENEGATIVE FACTORS...THE SHIPS...HWRF...AND GFDL MODELS CALL FOR KYLETO BECOME A HURRICANE. THE NEW INTENSITY FORECAST THUS CALLS FORTHE CYCLONE TO REACH A PEAK INTENSITY OF 65 KT IN 36 HR. AFTERTHAT TIME...KYLE WILL MOVE OVER COLD SEA SURFACE TEMPERATURES ANDBEGIN EXTRATROPICAL TRANSITION...AND THIS COMBINATION SHOULD CAUSEWEAKENING. KYLE SHOULD LOSE TROPICAL CHARACTERISTICS AFTERLANDFALL AND EVENTUALLY BE ABSORBED IN A FRONTAL SYSTEM IN AFRONTAL SYSTEM OVER EASTERN CANADA.INTERESTS IN EASTERN NEW ENGLAND AND THE CANADIAN MARITIMES SHOULDCLOSELY MONITOR THE PROGRESS OF KYLE. WATCHES MAY BE REQUIRED FORPORTIONS OF THE NEW ENGLAND COAST ON SATURDAY.

FORECAST POSITIONS AND MAX WINDSINITIAL 26/2100Z 27.6N 68.7W 50 KT 12HR VT 27/0600Z 29.5N 69.3W 55 KT 24HR VT 27/1800Z 32.6N 69.5W 60 KT 36HR VT 28/0600Z 36.5N 69.0W 65 KT 48HR VT 28/1800Z 40.3N 67.8W 65 KT 72HR VT 29/1800Z 47.5N 64.5W 45 KT...EXTRATROPICAL 96HR VT 30/1800Z 52.0N 62.0W 35 KT...INLAND EXTRATROPICAL120HR VT 01/1800Z...ABSORBED BY FRONTAL SYSTEM

Tropical Storm Kyle NHC Discussion 11AM EST

KYLE IS SHOWING A CLASSIC SHEAR PATTERN IN SATELLITE IMAGERY THISMORNING...WITH THE LOW-LEVEL CENTER PARTLY EXPOSED TO THE WEST OFTHE CONVECTION BY 15-20 KT OF WESTERLY VERTICAL WIND SHEAR. SATELLITE INTENSITY ESTIMATES FROM TAFB AND SAB ARE 45 KT...WHILERECENT QUIKSCAT DATA INDICATES BELIEVABLE WINDS OF 45 KT. BASED ONTHIS AND CONTINUITY FROM THE PREVIOUS ADVISORY...THE INITIALINTENSITY REMAINS 50 KT.THE INITIAL MOTION IS A SOMEWHAT WOBBLY 340/11...SLIGHTLY TO THELEFT OF THE PREVIOUS ADVISORY. OTHER THAN THAT...THERE IS LITTLECHANGE TO THE FORECAST PHILOSOPHY FROM THE PREVIOUS ADVISORY. KYLEIS ON THE SOUTHWEST SIDE OF A BUILDING RIDGE OVER THE CENTRALATLANTIC...AND SOON SHOULD PASS BETWEEN THE RIDGE AND A DEEP-LAYERLOW PRESSURE AREA OVER THE EASTERN UNITED STATES. THIS PATTERNSHOULD STEER KYLE GENERALLY NORTHWARD FOR THE NEXT 24-36 HR. AFTERTHAT...KYLE MAY TURN MORE TOWARD THE NORTH-NORTHEAST AS ITAPPROACHES THE MAIN BRANCH OF THE WESTERLIES AND THE NORTHERN ENDOF THE ATLANTIC RIDGE. SOME UNCERTAINTY EXISTS AS TO HOW FAST THENORTHERN END OF THE RIDGE MAY WEAKEN AND HOW SOON KYLE MAY ACQUIREAN EASTWARD COMPONENT OF MOTION...AS SOME OF THE GFS ENSEMBLES SHOWA STRONGER RIDGE AND A MORE NORTHWARD MOTION THAN THE OPERATIONALMODEL. HOWEVER...THE MODEL CONSENSUS HAS CHANGED LITTLE SINCE THEPREVIOUS PACKAGE...WITH THE CENTER OF THE GUIDANCE ENVELOPE OVERNORTHEASTERN NEW ENGLAND AND THE CANADIAN MARITIME PROVINCES. THENEW FORECAST TRACK IS SIMILAR TO...BUT A LITTLE SLOWER THAN THEPREVIOUS FORECAST AND IS NEAR THE CENTER OF THE GUIDANCE ENVELOPE.THE INTENSITY FORECAST IS PROBLEMATIC. THE CURRENT SHEAR MAYDECREASE SOMEWHAT OVER THE NEXT 24 HOURS...WHICH WOULD ALLOW KYLETO GRADUALLY INTENSIFY. AFTER THAT...KYLE IS FORECAST TO ENCOUNTERSTRONG...BUT DIVERGENT...UPPER-LEVEL SOUTHWESTERLY FLOW....WITH THERESULTING SHEAR TRYING TO WEAKEN THE CYCLONE AND THE DIVERGENCETRYING TO STRENGTHEN IT. WHICH OF THESE INFLUENCES WILL BE THESTRONGEST IS UNCLEAR AT THIS TIME. THE INTENSITY FORECAST CALLSFOR KYLE TO SLOWLY INTENSIFY DURING THE FIRST 48 HR IN AGREEMENTWITH MOST GUIDANCE...BECOMING A HURRICANE IN ABOUT 36 HR. AFTER 48HR...KYLE IS EXPECTED TO MOVE NORTH OF THE GULF STREAM INTO VERYCOLD WATER. WHILE THIS AND THE EXPECTED ONSET OF EXTRATROPICALTRANSITION SHOULD CAUSE KYLE TO WEAKEN...IT MAY STILL BE OFHURRICANE STRENGTH WHEN THE CENTER REACHES NEW ENGLAND OR THEMARITIMES. AFTER LANDFALL...KYLE SHOULD WEAKEN AND BECOMEEXTRATROPICAL...EVENTUALLY BEING ABSORBED IN A FRONTAL SYSTEM.INTERESTS IN EASTERN NEW ENGLAND AND THE CANADIAN MARITIMES SHOULDCLOSELY MONITOR THE PROGRESS OF KYLE.

FORECAST POSITIONS AND MAX WINDSINITIAL 26/1500Z 26.4N 68.8W 50 KT 12HR VT 27/0000Z 28.6N 69.4W 55 KT 24HR VT 27/1200Z 31.7N 69.9W 60 KT 36HR VT 28/0000Z 35.5N 69.8W 65 KT 48HR VT 28/1200Z 39.5N 68.7W 70 KT 72HR VT 29/1200Z 46.5N 66.0W 50 KT...INLAND EXTRATROPICAL 96HR VT 30/1200Z 52.0N 62.0W 40 KT...INLAND EXTRATROPICAL120HR VT 01/1200Z...ABSORBED BY FRONTAL SYSTEM$$FORECASTER BEVEN