| Track: http://www.nhc.noaa.gov/refresh/graphics_at2+shtml/081108.shtml?5day?large#contents TROPICAL STORM GABRIELLE DISCUSSION NUMBER 7 NWS NATIONAL HURRICANE CENTER MIAMI FL AL072013 500 AM AST TUE SEP 10 2013 DURING THE PAST 12 HOURS...INFRARED SATELLITE IMAGERY INDICATES DEEP CONVECTION HAS DEVELOPED AND PERSISTED OVER AND TO THE EAST OF THE WELL-DEFINED LOW-LEVEL CIRCULATION CENTER ASSOCIATED WITH THE REMNANTS OF GABRIELLE. IN ADDITION...AN EARLIER ASCAT OVERPASS CONTAINED SOME 34- TO 36-KT WIND VECTORS TO THE SOUTH OF THE CENTER AND OBSERVATIONS FROM NOAA BUOY 41049 LOCATED MORE THAN 100 NMI SOUTHEAST OF THE CENTER HAVE BEEN STEADILY INCREASING TO AT LEAST 31 KT OUTSIDE OF CONVECTION. BASED ON THE ABOVE DATA...ADVISORIES HAVE BEEN RE-INITIATED ON TROPICAL STORM GABRIELLE. AN AIR FORCE RESERVE AIRCRAFT IS SCHEDULED TO RECONNOITER THE CYCLONE THIS AFTERNOON TO PROVIDE MORE DETAILED INFORMATION ON THE EXACT LOCATION AND STRENGTH OF GABRIELLE. THE INITIAL MOTION ESTIMATE IS 360/10 KT...WHICH IS BASED MAINLY ON LIMITED MICROWAVE FIXES. THE NHC MODEL GUIDANCE IS IN VERY GOOD AGREEMENT ON GABRIELLE MOVING NORTHWARD TO NORTH-NORTHWESTWARD AND SLOWING DOWN DURING THE NEXT 36 TO 48 HOURS AS THE CYCLONE MOVES AROUND THE EASTERN PERIPHERY OF A RETROGRADING MID-/UPPER-LEVEL LOW CURRENTLY LOCATED JUST NORTH OF THE BAHAMAS. ON THE FORECAST TRACK...GABRIELLE IS EXPECTED TO PASS OVER OR NEAR BERMUDA IN ABOUT 24 HOURS. BY 72 HOURS...GABRIELLE IS FORECAST TO BEGIN TO LIFT OUT AND ACCELERATE NORTHWARD AND THEN NORTHEASTWARD AHEAD OF A STRONG MID-TROPOSPHERIC TROUGH AND FRONTAL SYSTEM THAT IS FORECAST TO MOVE OFF OF THE U.S. EAST COAST BY 96 HOURS. THE OFFICIAL FORECAST TRACK IS CLOSE TO THE MULTI-MODEL CONSENSUS TVCA. GABRIELLE IS EXPECTED TO REMAIN IN A MODERATE SHEAR ENVIRONMENT BUT OVER 28-29C SSTS FOR THE NEXT 24 HOURS OR SO...WHICH SHOULD ALLOW FOR SOME ADDITONAL STRENGTHENING TO OCCUR. THE INTENSITY IS EXPECTED TO LEVEL OFF BY 48 HOURS AS SOUTHWESTERLY VERTICAL WIND SHEAR BEGINS TO GRADUALLY INCREASE AHEAD OF THE AFOREMENTIONED APPROACHING FRONTAL SYSTEM. AT 72 HOURS AND BEYOND...GABRIELLE WILL BE MOVING OVER SUB-25C SSTS AND THE CYCLONE IS FORECAST TO BECOME A POST-TROPICAL/EXTRATROPICAL LOW BY 96 HOURS WHEN WATER TEMPERATURES WILL BE LESS THAN 20C. THE NHC INTENSITY FORECAST IS CLOSE TO THE CONSENSUS MODEL ICON. FORECAST POSITIONS AND MAX WINDS INIT 10/0900Z 29.6N 65.0W 35 KT 40 MPH 12H 10/1800Z 31.1N 65.0W 40 KT 45 MPH 24H 11/0600Z 32.7N 65.2W 45 KT 50 MPH 36H 11/1800Z 33.7N 65.7W 45 KT 50 MPH 48H 12/0600Z 34.5N 66.3W 45 KT 50 MPH 72H 13/0600Z 37.7N 65.9W 45 KT 50 MPH 96H 14/0600Z 46.8N 58.6W 45 KT 50 MPH...POST-TROP/EXTRATROP 120H 15/0600Z 56.5N 41.9W 45 KT 50 MPH...POST-TROP/EXTRATROP $$ FORECASTER STEWART TROPICAL STORM GABRIELLE ADVISORY NUMBER 7 NWS NATIONAL HURRICANE CENTER MIAMI FL AL072013 500 AM AST TUE SEP 10 2013 ...GABRIELLE REGENERATES INTO A TROPICAL STORM SOUTH OF BERMUDA... ...TROPICAL STORM WARNING IN EFFECT FOR BERMUDA... SUMMARY OF 500 AM AST...0900 UTC...INFORMATION ---------------------------------------------- LOCATION...29.6N 65.0W ABOUT 185 MI...300 KM S OF BERMUDA MAXIMUM SUSTAINED WINDS...40 MPH...65 KM/H PRESENT MOVEMENT...N OR 360 DEGREES AT 14 MPH...22 KM/H MINIMUM CENTRAL PRESSURE...1008 MB...29.77 INCHES WATCHES AND WARNINGS -------------------- CHANGES WITH THIS ADVISORY... THE BERMUDA WEATHER SERVICE HAS ISSUED A TROPICAL STORM WARNING FOR BERMUDA. SUMMARY OF WATCHES AND WARNINGS IN EFFECT... A TROPICAL STORM WARNING IS IN EFFECT FOR... * BERMUDA A TROPICAL STORM WARNING MEANS THAT TROPICAL STORM CONDITIONS ARE EXPECTED ON BERMUDA...IN THIS CASE WITHIN THE NEXT 12 TO 24 HOURS. FOR STORM INFORMATION SPECIFIC TO YOUR AREA...PLEASE MONITOR PRODUCTS ISSUED BY YOUR NATIONAL METEOROLOGICAL SERVICE. DISCUSSION AND 48-HOUR OUTLOOK ------------------------------ AT 500 AM AST...0900 UTC...THE CENTER OF TROPICAL STORM GABRIELLE WAS LOCATED NEAR LATITUDE 29.6 NORTH...LONGITUDE 65.0 WEST. GABRIELLE IS MOVING TOWARD THE NORTH NEAR 14 MPH...22 KM/H...AND THIS GENERAL MOTION IS FORECAST TO CONTINUE TODAY AND TONIGHT. A GRADUAL TURN TOWARD THE NORTH-NORTHWEST WITH A DECREASE IN FORWARD SPEED IS EXPECTED ON WEDNESDAY. ON THE FORECAST TRACK...GABRIELLE IS EXPECTED TO PASS OVER OR NEAR BERMUDA BY WEDNESDAY MORNING. MAXIMUM SUSTAINED WINDS ARE NEAR 40 MPH...65 KM/H...WITH HIGHER GUSTS. SOME STRENGTHENING IS FORECAST DURING THE NEXT 48 HOURS. TROPICAL-STORM-FORCE WINDS EXTEND OUTWARD UP TO 70 MILES...110 KM FROM THE CENTER. NOAA BUOY 41049 LOCATED WELL TO THE SOUTHEAST OF THE CENTER RECENTLY REPORTED A SUSTAINED WIND OF 36 MPH...57 KM/H AND A GUST TO 40 MPH...65 KM/H. THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 1008 MB...29.77 INCHES. HAZARDS AFFECTING LAND ---------------------- STORM SURGE...A STORM SURGE OF 2 TO 3 FEET ABOVE NORMAL TIDE LEVELS IS EXPECTED ON BERMUDA. IN ADDITION...ROUGH SURF CONDITIONS WILL BEGIN TO AFFECT BERMUDA BY THIS AFTERNOON. PLEASE CONSULT PRODUCTS FROM YOUR LOCAL WEATHER OFFICE. RAINFALL...GABRIELLE IS EXPECTED TO PRODUCE RAINFALL AMOUNTS OF 2 TO 4 INCHES OVER BERMUDA...WITH ISOLATED MAXIMUM TOTALS OF 6 INCHES POSSIBLE. WIND...TROPICAL STORM CONDITIONS ARE EXPECTED ON BERMUDA BY LATE TONIGHT AND CONTINUING INTO WEDNESDAY. NEXT ADVISORY ------------- NEXT INTERMEDIATE ADVISORY...800 AM AST. NEXT COMPLETE ADVISORY...1100 AM AST. $$ FORECASTER STEWART |