ZCZC MIATCDAT3 ALL TTAA00 KNHC DDHHMM HURRICANE SANDY DISCUSSION NUMBER 17 NWS NATIONAL HURRICANE CENTER MIAMI FL AL182012 1100 AM EDT FRI OCT 26 2012 STRONG SOUTH-SOUTHWESTERLY SHEAR AND THE INTRUSION OF DRY AIR CONTINUES TO AFFECT THE HURRICANE...AS VISIBLE SATELLITE IMAGES SHOW THAT THE LOW-LEVEL CENTER OF SANDY IS EXPOSED TO THE SOUTH OF THE MAIN MASS OF CONVECTION. USING A BLEND OF FLIGHT-LEVEL AND SFMR WINDS FROM THE HURRICANE HUNTER AIRCRAFT YIELDS A CURRENT INTENSITY ESTIMATE OF 70 KT. DYNAMICAL MODELS SHOW AN ADDITIONAL INCREASE IN SHEAR OVER THE NEXT 24 HOURS...WHICH SHOULD CAUSE AT LEAST SLIGHT WEAKENING. LATER IN THE FORECAST PERIOD...GLOBAL MODELS SHOW SOME RE-INTENSIFICATION OF THE CYCLONE...WHICH IS VERY LIKELY DUE TO BAROCLINIC INFLUENCES. BY 72 HOURS...THE MODELS SHOW SIGNIFICANT COLD AIR ADVECTION OVER THE SOUTHWEST PORTION OF THE CIRCULATION...WHICH SHOULD HASTEN THE EXTRATROPICAL TRANSITION PROCESS. THE OFFICIAL FORECAST SHOWS THE SYSTEM AS POST-TROPICAL AT 96 HOURS...THOUGH THERE IS SOME UNCERTAINTY AS TO THE TIMING OF THE TRANSITION. REGARDLESS...WHETHER SANDY IS OFFICIALLY TROPICAL OR POST-TROPICAL AT LANDFALL WILL HAVE LITTLE BEARING ON THE IMPACTS. LATEST FIXES FROM HURRICANE HUNTER AIRCRAFT SHOW A VERY SLOW MOTION WITH THE CENTER APPEARING TO HAVE TURNED NORTHWARD. THE CURRENT MOTION ESTIMATE IS 360/5. SANDY IS EXPECTED TO ESCAPE THE INFLUENCE OF A MID- TO UPPER-LEVEL TROUGH AND TO BEGIN TO MOVE NORTH-NORTHEASTWARD TO NORTHEASTWARD WITH AN INCREASE IN FORWARD SPEED OVER THE NEXT FEW DAYS. A SHORTWAVE TROUGH NEAR THE PACIFIC NORTHWEST COAST IS FORECAST TO MOVE EAST-SOUTHEASTWARD AND DIG AS IT APPROACHES THE EASTERN U.S. COAST BY 72 HOURS. THE FLOW ON THE NORTHEAST SIDE OF THIS SHORTWAVE SHOULD CAUSE SANDY TO TURN TOWARD THE NORTH AND NORTHWEST TOWARD THE COAST. THE OFFICIAL TRACK FORECAST IS VERY SIMILAR TO THE PREVIOUS ONE AND ALSO VERY CLOSE TO THE LATEST DYNAMICAL MODEL CONSENSUS. USERS ARE REMINDED TO NOT FOCUS ON THE DETAILS OF THE TRACK FORECAST LATE IN THE PERIOD...AS SANDY IS EXPECTED TO BRING IMPACTS TO A LARGE PART OF THE U.S. EAST COAST INTO EARLY NEXT WEEK. FORECAST POSITIONS AND MAX WINDS INIT 26/1500Z 26.7N 76.9W 70 KT 80 MPH 12H 27/0000Z 27.6N 77.4W 70 KT 80 MPH 24H 27/1200Z 28.9N 76.8W 65 KT 75 MPH 36H 28/0000Z 30.5N 75.5W 65 KT 75 MPH 48H 28/1200Z 32.2N 73.7W 70 KT 80 MPH 72H 29/1200Z 36.0N 72.5W 70 KT 80 MPH 96H 30/1200Z 39.0N 75.5W 65 KT 75 MPH...POST-TROPICAL 120H 31/1200Z 40.5N 78.0W 50 KT 60 MPH...POST-TROP/EXTRATROP $$ FORECASTER PASCH NNNN
Alternate Formats
About Alternates -
E-Mail Advisories -
RSS Feeds
Cyclone Forecasts
Latest Advisory -
Past Advisories -
About Advisories
Marine Forecasts
Latest Products -
About Marine Products
Tools & Data
Satellite Imagery -
US Weather Radar -
Aircraft Recon -
Local Data Archive -
Forecast Verification -
Deadliest/Costliest/Most Intense
Learn About Hurricanes
Storm Names
Wind Scale -
Prepare -
Climatology -
NHC Glossary -
NHC Acronyms -
Frequently Asked Questions -
AOML Hurricane-Research Division
About Us
About NHC -
Mission/Vision -
Other NCEP Centers -
NHC Staff -
Visitor Information -
NHC Library
NOAA/
National Weather Service
National Centers for Environmental Prediction
National Hurricane Center
11691 SW 17th Street
Miami, Florida, 33165-2149 USA
nhcwebmaster@noaa.gov
Disclaimer
Privacy Policy
Credits
About Us
Glossary
Career Opportunities
Page last modified: Monday, 31-Dec-2012 12:09:55 UTC