|
Show Selection: |
| #222647 (Received by flhurricane at: 11:08 AM 17.Oct.2008) TCDAT5 TROPICAL STORM OMAR DISCUSSION NUMBER 17 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL152008 1100 AM EDT FRI OCT 17 2008 OMAR HAS RE-INTENSIFIED SOME THIS MORNING AS SHOWN IN THE STRONGLY CURVED BANDED STRUCTURE FROM GEOSTATIONARY SATELLITE IMAGERY. THE DVORAK ESTIMATE FROM TAFB SUGGESTED 55 KT AT 12 UTC...THOUGH IMPROVED DEEP CONVECTION SINCE WOULD INDICATE A STRONGER CYCLONE AT ADVISORY TIME. ADDITIONALLY...A WELL-PLACED QUIKSCAT OVERPASS AT 0922 UTC SHOWED SEVERAL BELIEVABLE 55-60 KT VECTORS AND TWO HURRICANE FORCE WINDS...THOUGH THESE MIGHT HAVE SOME RAIN CONTAMINATION BOOSTING THE VALUES. CURRENT INTENSITY IS SET AT 60 KT...ALTHOUGH OMAR COULD BE A MARGINAL HURRICANE. OMAR HAS ACCELERATED TO ABOUT 30 KT TOWARD THE NORTHEAST UNDER THE INFLUENCE OF A SHORTWAVE TROUGH JUST TO THE NORTHWEST AND A DEEP-LAYER RIDGE TO THE EAST. THIS TROUGH ADVECTS ALONG QUICKLY TOWARD THE EAST-NORTHEAST AND LEAVES OMAR BEHIND...LIKELY CAUSING THE CYCLONE TO SLOW DOWN SIGNIFICANTLY IN THE NEXT DAY OR SO. THE EXTRATROPICAL STORM THAT WILL EMERGE OFF OF THE U.S. EAST COAST EARLY ON SUNDAY IS THE FEATURE THAT IS EXPECTED TO ABSORB OMAR LATE IN THE FORECAST PERIOD. THIS IS THE SOLUTION FAVORED BY ALL OF THE GLOBAL AND HURRICANE MODELS...WITH THE EXCEPTION OF NOGAPS WHICH MAINTAINS OMAR AS A SEPARATE ENTITY AND LOOPS IT BACK TOWARD THE SOUTH AND WEST. THE TRACK FORECAST IS BASED A BLEND OF A CONSENSUS OF THESE MODELS...WITH THE EXCEPTION OF NOGAPS...AND THE FASTER PREVIOUS ADVISORY. OMAR HAS A SHORT WINDOW OF OPPORTUNITY TO INTENSIFY BEFORE REACHING COOLER WATERS AND UNDER MUCH STRONGER SHEAR IN ABOUT 24 HOURS. CURRENTLY...OMAR IS MOVING IN THE DIRECTION OF...BUT FASTER THAN... THE SHEAR VECTOR...WHICH MAY HAVE SOMEWHAT COUNTERACTED THE OTHERWISE LARGE NEGATIVE SHEAR INFLUENCE. ANOTHER LIMITING FACTOR IS THAT THE CYCLONE IS NEARLY SURROUNDED BY DRY AIR IN THE MID TO LOW TROPOSPHERE. THE FORECAST CALLS FOR NO SIGNIFICANT CHANGE IN WINDS DURING THE NEXT DAY OR SO WITH GRADUAL WEAKENING THEREAFTER ...IN BEST AGREEMENT WITH THE LGEM STATISTICAL AND HWRF DYNAMICAL MODELS. FORECAST POSITIONS AND MAX WINDS INITIAL 17/1500Z 28.9N 55.1W 60 KT 12HR VT 18/0000Z 31.4N 53.2W 60 KT 24HR VT 18/1200Z 33.4N 51.3W 55 KT 36HR VT 19/0000Z 35.1N 49.2W 50 KT 48HR VT 19/1200Z 36.6N 47.0W 45 KT 72HR VT 20/1200Z 39.0N 42.0W 40 KT...BECOMING EXTRATROPICAL 96HR VT 21/1200Z 40.5N 36.0W 35 KT...EXTRATROPICAL 120HR VT 22/1200Z...ABSORBED BY EXTRATROPICAL LOW $$ FORECASTER LANDSEA/STEWART |
