Home › discussion
 

Keywords :   


Tag: discussion

Tropical Storm ANDREA Forecast Discussion Number 7

2013-06-07 10:36:11| National Hurricane Center (Atlantic)

Issued at 500 AM EDT FRI JUN 07 2013 000 WTNT41 KNHC 070836 TCDAT1 TROPICAL STORM ANDREA DISCUSSION NUMBER 7 NWS NATIONAL HURRICANE CENTER MIAMI FL AL012013 500 AM EDT FRI JUN 07 2013 ANDREA IS RAPIDLY LOSING TROPICAL CHARACTERISTICS. MOST OF THE RAIN IS NOW DISPLACED TO THE NORTHWESTERN SEMICIRCLE...AND THERE IS AN INTRUSION OF DRY AIR BETWEEN THE CENTER AND A CONVECTIVE BAND TO THE EAST. BUOY AND RADAR DATA STILL SUPPORTS AN INITIAL INTENSITY OF 40 KNOTS....BUT THESE WINDS ARE OCCURRING OVER WATER IN THE EASTERN SEMICIRCLE. ANDREA IS ALREADY EMBEDDED IN THE MID-LATITUDE WESTERLIES AND THE TRANSFORMATION PROCESS INTO A POST- TROPICAL/EXTRATROPICAL CYCLONE IS FORECAST TO CONTINUE TODAY. ANDREA HAS INCREASED ITS FORWARD SPEED AND IS MOVING TOWARD THE NORTHEAST OR 040 DEGREES AT 23 KNOTS EMBEDDED IN THE FAST FLOW AHEAD OF A MID-LATITUDE TROUGH. GLOBAL MODELS AND TRACK GUIDANCE SUGGEST THAT THE CYCLONE WILL ACCELERATE FURTHER AS IT MOVES ALONG THE EASTERN SEABOARD AND THEN TURN TO THE EAST-NORTHEAST OVER THE NORTH ATLANTIC. THE OFFICIAL FORECAST CONTINUES TO FOLLOW THIS SOLUTION. THE CYCLONE IS EXPECTED TO BECOME ABSORBED BY A LARGER EXTRATROPICAL LOW IN ABOUT 3 DAYS OR SO. BASED ON THE ASSUMPTION THAT ANDREA WILL BECOME POST-TROPICAL THIS MORNING...AND THAT THE WINDS ARE CONFINED TO THE EASTERN SEMICIRCLE...WE DO NOT EXPECT TO EXTEND THE TROPICAL WARNINGS ANY FARTHER NORTH ALONG THE COAST. OUR CURRENT INTENTION IS THAT ANY HAZARDOUS WIND CONDITIONS FROM THE DELMARVA PENINSULA NORTHWARD TO NEW ENGLAND WOULD BE HANDLED BY LOCAL NATIONAL WEATHER SERVICE WARNING PRODUCTS. FORECAST POSITIONS AND MAX WINDS INIT 07/0900Z 32.4N 80.7W 40 KT 45 MPH 12H 07/1800Z 35.0N 78.0W 40 KT 45 MPH...POST-TROPICAL 24H 08/0600Z 39.5N 73.0W 40 KT 45 MPH...POST-TROPICAL 36H 08/1800Z 43.5N 67.0W 40 KT 45 MPH...POST-TROP/EXTRATROP 48H 09/0600Z 46.5N 58.5W 35 KT 40 MPH...POST-TROP/EXTRATROP 72H 10/0600Z 46.0N 40.0W 35 KT 40 MPH...POST-TROP/EXTRATROP 96H 11/0600Z...ABSORBED $$ FORECASTER AVILA

Tags: number discussion storm andrea

 

Tropical Storm ANDREA Forecast Discussion Number 6

2013-06-07 04:35:39| National Hurricane Center (Atlantic)

Issued at 1100 PM EDT THU JUN 06 2013 000 WTNT41 KNHC 070235 TCDAT1 TROPICAL STORM ANDREA DISCUSSION NUMBER 6 NWS NATIONAL HURRICANE CENTER MIAMI FL AL012013 1100 PM EDT THU JUN 06 2013 ANDREA HAS WEAKENED CONSIDERABLY SINCE MOVING INLAND EARLIER THIS EVENING. THE ONLY REPORT OF TROPICAL-STORM-FORCE WINDS ON LAND OR OVER WATER HAS COME FROM A SHIP OBSERVATION EAST OF SAINT AUGUSTINE...AND THE INITIAL INTENSITY HAS BEEN LOWERED TO 40 KT. ANY WINDS THIS STRONG ARE LIKELY OCCURRING IN RANBANDS OFFSHORE TO THE EAST OF THE CENTER. THE SATELLITE PRESENTATION OF ANDREA BEARS LITTLE RESEMBLANCE TO A TROPICAL CYCLONE...WITH A PRONOUNCED DRY INTRUSION NOTED OVER AND SOUTHWEST OF THE CENTER AND THE DEEP CONVECTION IN A BAND WELL REMOVED TO THE EAST AND SOUTHEAST. GIVEN THAT ONLY SHALLOW CONVECTION IS OCCURRING NEAR THE CENTER... INTERACTION WITH BAROCLINIC FEATURES WILL INCREASINGLY BECOME THE MECHANISM SUPPORTING THE CYCLONE THROUGH THE FORECAST PERIOD. AS ANDREA IS ABSORBED BY A LIFTING MID/UPPER-LEVEL TROUGH...GLOBAL MODEL GUIDANCE SHOWS LITTLE CHANGE IN INTENSITY DURING THE FORECAST PERIOD. THE NEW NHC FORECAST FOLLOWS THIS THINKING...AND SHOWS ANDREA BECOMING POST-TROPICAL BY 24 HOURS. HOWEVER...THIS COULD OCCUR SOONER IF THE CONVECTIVE STRUCTURE DOES NOT IMPROVE. THE INITIAL MOTION IS 045/13...AS THE CENTER SLOWED A LITTLE WHILE MOVING ONSHORE. THE TRACK MODEL GUIDANCE REMAINS IN VERY GOOD AGREEMENT SHOWING THE CYCLONE ACCELERATING NORTHEASTWARD ALONG THE U.S. EAST COAST AHEAD OF THE AFOREMENTIONED TROUGH AND THEN TURNING QUICKLY EASTWARD OVER THE NORTH ATLANTIC. THE NEW NHC FORECST IS A LITTLE TO THE RIGHT OF THE PREVIOUS ONE FOR THE FIRST 24 HOURS DUE TO THE INITIAL MOTION AND IS LARGELY AN UPDATE OF THE PREVIOUS PACKAGE AFTERWARD. THE NHC TRACK IS CLOSE TO A BLEND OF THE GFS AND ECMWF AND ALSO LIES NEAR THE FSU SUPERENSEMBLE. BASED ON THE ASSUMPTION THAT ANDREA WILL BECOME POST-TROPICAL IN ABOUT 24 HOURS...WE DO NOT EXPECT TO EXTEND THE TROPICAL WARNINGS ANY FARTHER NORTH ALONG THE COAST. OUR CURRENT INTENTION IS THAT ANY HAZARDOUS WIND CONDITIONS FROM THE DELMARVA PENINSULA NORTHWARD TO NEW ENGLAND WOULD BE HANDLED BY LOCAL NATIONAL WEATHER SERVICE WARNING PRODUCTS. FORECAST POSITIONS AND MAX WINDS INIT 07/0300Z 30.3N 82.4W 40 KT 45 MPH...INLAND 12H 07/1200Z 33.0N 80.2W 40 KT 45 MPH...INLAND 24H 08/0000Z 36.8N 76.3W 40 KT 45 MPH...POST-TROPICAL 36H 08/1200Z 41.0N 70.7W 40 KT 45 MPH...POST-TROP/EXTRATROP 48H 09/0000Z 44.7N 63.3W 35 KT 40 MPH...POST-TROP/EXTRATROP 72H 10/0000Z 45.5N 46.0W 35 KT 40 MPH...POST-TROP/EXTRATROP 96H 11/0000Z 45.5N 24.0W 35 KT 40 MPH...POST-TROP/EXTRATROP 120H 12/0000Z...DISSIPATED $$ FORECASTER BRENNAN

Tags: number discussion storm andrea

 
 

Tropical Storm ANDREA Forecast Discussion Number 5

2013-06-06 22:50:34| National Hurricane Center (Atlantic)

Issued at 500 PM EDT THU JUN 06 2013 000 WTNT41 KNHC 062050 TCDAT1 TROPICAL STORM ANDREA DISCUSSION NUMBER 5 NWS NATIONAL HURRICANE CENTER MIAMI FL AL012013 500 PM EDT THU JUN 06 2013 THE CENTER OF ANDREA IS NOW NEAR THE COAST OF THE FLORIDA BIG BEND REGION. ALTHOUGH THE CENTRAL CONVECTION HAS WEAKENED CONSIDERABLY SINCE THIS MORNING...AN AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT FOUND AN INNER WIND CORE...WITH SFMR SURFACE WIND ESTIMATES OF 55 KT ABOUT 20 N MI EAST OF THE CENTER AND 850 MB FLIGHT-LEVEL WINDS OF 71 KT. THE MINIMUM CENTRAL PRESSURE WAS 993 MB. ALTHOUGH IT IS POSSIBLE THAT THERE WAS A SHOALING CONTRIBUTION TO THE SFMR DATA...THE INITIAL INTENSITY IS ESTIMATED AT 55 KT. NO ADDITIONAL STRENGTHENING IS EXPECTED BEFORE LANDFALL. THE INITIAL MOTION IS 040/15. ANDREA SHOULD ACCELERATE INTO THE WESTERLIES DURING THE NEXT 24-48 HOURS AND MOVE QUICKLY NORTHEASTWARD ALONG THE U. S. EAST COAST AND NEAR THE CANADIAN MARITIMES. AFTER 48 HOURS...THE CYCLONE IS EXPECTED TO TURN EASTWARD AND MOVE RAPIDLY INTO THE OPEN ATLANTIC...WITH THIS GENERAL MOTION CONTINUING UNTIL DISSIPATION. WHILE THE GUIDANCE SHOWS SOME SPREAD IN BOTH DIRECTION AND SPEED...THERE IS NO SIGNIFICANT CHANGE SINCE THE LAST ADVISORY AND THE NEW FORECAST TRACK IS SIMILAR TO THE OLD ONE. ANDREA SHOULD WEAKEN AFTER LANDFALL. SUBSEQUENTLY...THE CYCLONE SHOULD GRADUALLY MERGE WITH A BAROCLINIC ZONE AS IT MOVES OVER AND NEAR THE EASTERN UNITED STATES...WHICH SHOULD RESULT IN EXTRATROPICAL TRANSITION OCCURRING DURING THE NEXT 36 HOURS. AFTER THAT...THE CYCLONE SHOULD CONTINUE AS AN EXTRATROPICAL GALE UNTIL DISSIPATION AROUND 120 HOURS. THERE IS A CHANCE THAT THE CONVECTION COULD DISSIPATE BEFORE EXTRATROPICAL TRANSITION IS COMPLETE...WHICH COULD CAUSE ANDREA TO HAVE A POST-TROPICAL PHASE BEFORE IT BECOMES EXTRATROPICAL. THERE ARE NO CHANGES TO THE TROPICAL STORM WARNINGS ON THIS ADVISORY. BASED ON THE ASSUMPTION THAT ANDREA WILL BECOME POST-TROPICAL/EXTRATOPICAL IN ABOUT 36 HOURS...WE DO NOT EXPECT TO EXTEND THE TROPICAL WARNINGS ANY FARTHER NORTH ALONG THE COAST. OUR CURRENT INTENTION IS THAT ANY HAZARDOUS WIND CONDITIONS FROM THE DELMARVA PENINSULA NORTHWARD TO NEW ENGLAND WOULD BE HANDLED BY LOCAL NATIONAL WEATHER SERVICE WARNING PRODUCTS. REGARDLESS OF THE EXACT TRACK OF THE CENTER OF ANDREA...THE PRIMARY EFFECTS ARE EXPECTED TO BE HEAVY RAINFALL ACROSS MUCH OF THE FLORIDA PENINSULA AND INTO THE COASTAL SECTIONS OF THE SOUTHEASTERN UNITED STATES...STORM SURGE FLOODING ALONG PORTIONS OF THE WEST COAST OF FLORIDA...AND ISOLATED TORNADOES TONIGHT FROM THE FLORIDA PENINSULA NORTHWARD THROUGH THE COASTAL PORTIONS OF GEORGIA...SOUTH CAROLINA...AND NORTH CAROLINA. FORECAST POSITIONS AND MAX WINDS INIT 06/2100Z 29.5N 83.4W 55 KT 65 MPH...NEAR COAST 12H 07/0600Z 31.9N 81.4W 45 KT 50 MPH...INLAND 24H 07/1800Z 35.6N 78.2W 40 KT 45 MPH...INLAND 36H 08/0600Z 39.8N 73.3W 40 KT 45 MPH...POST-TROP/EXTRATROP 48H 08/1800Z 43.8N 67.2W 40 KT 45 MPH...POST-TROP/EXTRATROP 72H 09/1800Z 46.6N 50.0W 35 KT 40 MPH...POST-TROP/EXTRATROP 96H 10/1800Z 46.0N 29.5W 35 KT 40 MPH...POST-TROP/EXTRATROP 120H 11/1800Z...DISSIPATED $$ FORECASTER BEVEN

Tags: number discussion storm andrea

 

Tropical Storm ANDREA Forecast Discussion Number 4

2013-06-06 16:54:38| National Hurricane Center (Atlantic)

Issued at 1100 AM EDT THU JUN 06 2013 000 WTNT41 KNHC 061454 TCDAT1 TROPICAL STORM ANDREA DISCUSSION NUMBER 4 NWS NATIONAL HURRICANE CENTER MIAMI FL AL012013 1100 AM EDT THU JUN 06 2013 EVEN THOUGH THE RADAR PRESENTATION OF ANDREA HAS BEEN IMPROVING DURING THE PAST FEW HOURS...CONVECTIVE CLOUD TOPS NEAR THE CENTER OF CIRCULATION HAVE BEEN WARMING. THE STRONGEST CONVECTION REMAINS LOCATED IN A BAND THAT IS MOVING ONSHORE THE WEST COAST OF FLORIDA AT THIS TIME...AND THE TAMPA WSR-88D HAS BEEN SHOWING 65-70 KT AT ABOUT 6500 FT. THE INITIAL INTENSITY IS BEING HELD AT 50 KT PENDING THE NEXT AIR FORCE RECONNAISSANCE MISSION THIS AFTERNOON. ANDREA HAS TURNED NORTHEASTWARD AND IS BEGINNING TO ACCELERATE WITH AN INITIAL MOTION OF 035/13 KT. THE STORM IS LOCATED JUST TO THE EAST OF A MID- TO UPPER-LEVEL TROUGH AXIS...AND IT IS GETTING CLOSER TO FASTER MID-LATITUDE FLOW LOCATED OVER THE TENNESSEE VALLEY. THIS FLOW IS EXPECTED TO CAUSE ANDREA TO RACE NORTHEASTWARD ALONG THE EAST COAST OF THE UNITED STATES DURING THE NEXT 48 HOURS OR SO. THERE IS VERY LITTLE SPREAD AMONG THE TRACK GUIDANCE...AND ESSENTIALLY NO CHANGES WERE REQUIRED FROM THE PREVIOUS OFFICIAL TRACK FORECAST. GIVEN THE CONFLICTING SIGNALS IN RADAR AND SATELLITE DATA...THERE IS NO STRONG EVIDENCE THAT ANDREA WILL STRENGTHEN MUCH BEFORE IT REACHES THE COAST LATER TODAY. AFTER THE CENTER MOVES INLAND... SOME WEAKENING IS EXPECTED...BUT MOST OF THE INTENSITY GUIDANCE INDICATE THAT ANDREA WILL MAINTAIN TROPICAL-STORM INTENSITY THROUGH THE FORECAST PERIOD. THE MAIN QUESTION IS WHEN EXTRATROPICAL TRANSITION WILL BE COMPLETE. THE GLOBAL MODEL FIELDS DO NOT SHOW STRONG BAROCLINICITY UNTIL ABOUT 48 HOURS...BUT THE FSU PHASE-SPACE DIAGRAMS BASED ON THE GFS SUGGEST THAT THE TRANSITION COULD BE COMPLETE BY 36 HOURS. FOR NOW...THE OFFICIAL FORECAST WILL KEEP ANDREA AS TROPICAL UNTIL 36 HOURS. THERE ARE NO CHANGES TO THE TROPICAL STORM WARNINGS ON THIS ADVISORY. BASED ON THE ASSUMPTION THAT ANDREA WILL BECOME POST-TROPICAL IN 36 TO 48 HOURS...WE DO NOT EXPECT TO EXTEND THE TROPICAL WARNINGS ANY FURTHER NORTH ALONG THE COAST. OUR CURRENT INTENTION IS THAT ANY HAZARDOUS WIND CONDITIONS FROM THE DELMARVA PENINSULA NORTHWARD TO NEW ENGLAND WOULD BE HANDLED BY LOCAL NATIONAL WEATHER SERVICE WARNING PRODUCTS. REGARDLESS OF THE EXACT TRACK OF THE CENTER OF ANDREA...THE PRIMARY EFFECTS ARE EXPECTED TO BE HEAVY RAINFALL ACROSS MUCH OF THE FLORIDA PENINSULA AND INTO THE COASTAL SECTIONS OF THE SOUTHEASTERN UNITED STATES...STORM SURGE FLOODING ALONG PORTIONS OF THE WEST COAST OF FLORIDA...AND ISOLATED TORNADOES TODAY ACROSS THE FLORIDA PENINSULA. FORECAST POSITIONS AND MAX WINDS INIT 06/1500Z 28.2N 84.3W 50 KT 60 MPH 12H 07/0000Z 30.3N 82.9W 45 KT 50 MPH...INLAND 24H 07/1200Z 33.4N 80.1W 40 KT 45 MPH...INLAND 36H 08/0000Z 37.3N 76.0W 40 KT 45 MPH...INLAND 48H 08/1200Z 41.8N 70.2W 40 KT 45 MPH...POST-TROP/EXTRATROP 72H 09/1200Z 46.5N 54.0W 35 KT 40 MPH...POST-TROP/EXTRATROP 96H 10/1200Z 47.0N 33.0W 35 KT 40 MPH...POST-TROP/EXTRATROP 120H 11/1200Z 52.0N 20.0W 45 KT 50 MPH...POST-TROP/EXTRATROP $$ FORECASTER BERG/BEVEN

Tags: number discussion storm andrea

 

Tropical Storm ANDREA Forecast Discussion Number 3

2013-06-06 10:50:17| National Hurricane Center (Atlantic)

Issued at 400 AM CDT THU JUN 06 2013 000 WTNT41 KNHC 060850 TCDAT1 TROPICAL STORM ANDREA DISCUSSION NUMBER 3 NWS NATIONAL HURRICANE CENTER MIAMI FL AL012013 400 AM CDT THU JUN 06 2013 SATELLITE IMAGERY AND DATA FROM AN AIR FORCE RESERVE HURRICANE HUNTER PLANE INDICATE THAT ANDREA IS STRONGER. THE PLANE REPORTED FLIGHT-LEVEL WINDS OF 63 KNOTS AT 5000 FEET AND BIAS-CORRECTED SFMR WINDS OF 49 KNOTS IN THE EASTERN QUADRANT. THE CENTRAL PRESSURES REPORTED BY THE AIRCRAFT WERE 997 MB FROM A DROP AND 996 MB EXTRAPOLATED. ON THIS BASIS...THE INITIAL INTENSITY HAS BEEN INCREASED TO 50 KNOTS. WE MUST EMPHASIZE THAT THESE STRONG WINDS ARE CONFINED TO THE EASTERN SEMICIRCLE. ANDREA IS PROBABLY NEAR ITS PEAK INTENSITY SINCE STRONG SHEAR SHOULD HALT ANY SIGNIFICANT INTENSIFICATION BEFORE LANDFALL. ANDREA WILL INTERACT WITH AN UPPER-LEVEL TROUGH AND BEGIN TO LOSE TROPICAL CHARACTERISTICS IN ABOUT 36 HOURS...BUT TROPICAL STORM FORCE WINDS ASSOCIATED WITH THE CYCLONE ARE FORECAST TO AFFECT THE EAST COAST OF THE UNITED STATES. FIXES FROM THE RECONNAISSANCE PLANE INDICATE THAT ANDREA IS MOVING TOWARD THE NORTH-NORTHEAST ABOUT 11 KNOTS. GIVEN THE FORECAST STEERING PATTERN PROVIDED BY GLOBAL MODELS...ANDREA SHOULD SOON BEGIN TO ACCELERATE AND TURN MORE TO THE NORTHEAST. THE OFFICIAL TRACK FORECAST IS A BLEND OF THE SLOWER ECMWF AND THE FASTER GFS MODELS. REGARDLESS OF THE EXACT TRACK OF THE CENTER OF ANDREA...THE PRIMARY EFFECTS ARE EXPECTED TO BE HEAVY RAINFALL ACROSS MUCH OF THE FLORIDA PENINSULA AND INTO THE COASTAL SECTIONS OF THE SOUTHEASTERN UNITED STATES...STORM SURGE FLOODING ALONG PORTIONS OF THE WEST COAST OF FLORIDA...AND ISOLATED TORNADOES TODAY ACROSS THE FLORIDA PENINSULA. FORECAST POSITIONS AND MAX WINDS INIT 06/0900Z 27.0N 85.9W 50 KT 60 MPH 12H 06/1800Z 29.0N 84.5W 50 KT 60 MPH 24H 07/0600Z 32.0N 82.0W 40 KT 45 MPH...INLAND 36H 07/1800Z 36.0N 78.0W 40 KT 45 MPH...INLAND 48H 08/0600Z 39.0N 73.5W 40 KT 45 MPH...POST-TROP/EXTRATROP 72H 09/0600Z 46.5N 59.5W 35 KT 40 MPH...POST-TROP/EXTRATROP 96H 10/0600Z 46.5N 37.0W 35 KT 40 MPH...POST-TROP/EXTRATROP 120H 11/0600Z 52.5N 23.0W 45 KT 50 MPH...POST-TROP/EXTRATROP $$ FORECASTER AVILA

Tags: number discussion storm andrea

 

Sites : [1267] [1268] [1269] [1270] [1271] [1272] [1273] [1274] [1275] [1276] [1277] [1278] [1279] [1280] [1281] [1282] [1283] [1284] [1285] [1286] next »