je.st
news
Tag: sam
Tropical Storm Sam Forecast Discussion Number 6
2021-09-24 04:40:34| National Hurricane Center (Atlantic)
Issued at 1100 PM AST Thu Sep 23 2021 000 WTNT43 KNHC 240240 TCDAT3 Tropical Storm Sam Discussion Number 6 NWS National Hurricane Center Miami FL AL182021 1100 PM AST Thu Sep 23 2021 Microwave data from around the time of the previous advisory revealed that Sam has developed a well-defined inner core, including a nearly closed eyewall feature in the 91-GHz channel. Dvorak estimates from TAFB and SAB have increased to T3.5 and T4.0, respectively, and the initial intensity is therefore estimated to be 60 kt. Sam's 24-hour intensity change qualifies as rapid intensification, since the cyclone was only a 30-kt tropical depression at this time yesterday. Sam is small, however. Recent scatterometer data showed that tropical-storm-force winds only extend a maximum of 40 n mi from the center, and the radius of maximum winds is estimated to be about 15 n mi. This small size is likely to have implications on Sam's future intensity. Sam is moving a little slower toward the west (280/13 kt). A mid-tropospheric ridge is expected to build across the Caribbean Sea and extend northeastward over the central Atlantic during the next few days. This blocking high is expected to cause Sam to slow down to 6 to 7 kt by late Saturday and Sunday while it maintains a westward to west-northwestward heading. Global models suggest the ridge may weaken and shift eastward a bit by days 4 and 5, allowing Sam to turn to the northwest and speed up a little by the end of the forecast period. The ECMWF, HWRF, and HCCA models lie along the southern edge of the main pack of models, while the ECENS ensemble mean is even farther south. The GFS and the HMON are on the northern side. Partially due to an adjustment of the initial position, the new NHC track forecast has been shifted southward a bit from the previous forecast, and it lies just south of the TVCA consensus aid--but not as far to the left as the previously mentioned southern models. Environmental conditions and Sam's structure and size are ideal for continued rapid intensification (RI). The SHIPS RI index for a 30-kt increase in 24 hours is nearly 50 percent. The DTOPS methodology, which uses inputs from the statistical-dynamical and deterministic models, shows RI indices for various forecast periods exceeding 90 percent. Therefore, rapid strengthening is being forecast at least for the next 36 hours, with Sam becoming a hurricane very soon and then a major hurricane by Friday night or Saturday morning. One caveat to this forecast is that although Sam's small size more readily allows for RI to occur, it can also make the cyclone more prone to weakening if, for example, vertical shear increases. By 48 hours, the intensity models show the strengthening trend leveling off, and the NHC intensity forecast follows suit. Fluctuations in intensity from days 3 through 5 are likely, both due to normal internal dynamics within the storm and the cyclone's response to the surrounding environment in relation to its small size. FORECAST POSITIONS AND MAX WINDS INIT 24/0300Z 11.2N 40.9W 60 KT 70 MPH 12H 24/1200Z 11.4N 42.9W 75 KT 85 MPH 24H 25/0000Z 11.8N 45.0W 90 KT 105 MPH 36H 25/1200Z 12.1N 46.6W 105 KT 120 MPH 48H 26/0000Z 12.5N 47.8W 110 KT 125 MPH 60H 26/1200Z 13.0N 49.1W 110 KT 125 MPH 72H 27/0000Z 13.5N 50.4W 110 KT 125 MPH 96H 28/0000Z 15.3N 53.2W 110 KT 125 MPH 120H 29/0000Z 17.3N 56.1W 110 KT 125 MPH $$ Forecaster Berg
Tags: number
discussion
sam
storm
Summary for Tropical Storm Sam (AT3/AL182021)
2021-09-24 04:40:02| National Hurricane Center (Atlantic)
...SMALL SAM RAPIDLY INTENSIFYING... ...RAPID INTENSIFICATION FORECAST TO CONTINUE THROUGH SATURDAY... As of 11:00 PM AST Thu Sep 23 the center of Sam was located near 11.2, -40.9 with movement W at 15 mph. The minimum central pressure was 997 mb with maximum sustained winds of about 70 mph.
Tags: summary
sam
storm
tropical
Tropical Storm Sam Public Advisory Number 6
2021-09-24 04:40:02| National Hurricane Center (Atlantic)
Issued at 1100 PM AST Thu Sep 23 2021 318 WTNT33 KNHC 240239 TCPAT3 BULLETIN Tropical Storm Sam Advisory Number 6 NWS National Hurricane Center Miami FL AL182021 1100 PM AST Thu Sep 23 2021 ...SMALL SAM RAPIDLY INTENSIFYING... ...RAPID INTENSIFICATION FORECAST TO CONTINUE THROUGH SATURDAY... SUMMARY OF 1100 PM AST...0300 UTC...INFORMATION ----------------------------------------------- LOCATION...11.2N 40.9W ABOUT 1560 MI...2505 KM ESE OF THE NORTHERN LEEWARD ISLANDS MAXIMUM SUSTAINED WINDS...70 MPH...110 KM/H PRESENT MOVEMENT...W OR 280 DEGREES AT 15 MPH...24 KM/H MINIMUM CENTRAL PRESSURE...997 MB...29.44 INCHES WATCHES AND WARNINGS -------------------- There are no coastal watches or warnings in effect. DISCUSSION AND OUTLOOK ---------------------- At 1100 PM AST (0300 UTC), the center of Tropical Storm Sam was located near latitude 11.2 North, longitude 40.9 West. Sam is moving toward the west near 15 mph (24 km/h), and this motion with a decrease in forward speed is expected through Saturday. A motion toward the west-northwest at an even slower forward speed is expected late Saturday into Sunday. Sam is rapidly intensifying, and maximum sustained winds have increased to near 70 mph (110 km/h) with higher gusts. Rapid intensification is forecast to continue through early Saturday. Sam is likely to become a hurricane very soon and then could be a major hurricane by Friday night or early Saturday. Sam is a small tropical storm. Tropical-storm-force winds extend outward up to 45 miles (75 km) from the center. The estimated minimum central pressure is 997 mb (29.44 inches). HAZARDS AFFECTING LAND ---------------------- None. NEXT ADVISORY ------------- Next complete advisory at 500 AM AST. $$ Forecaster Berg
Tropical Storm Sam Wind Speed Probabilities Number 6
2021-09-24 04:40:02| National Hurricane Center (Atlantic)
Issued at 0300 UTC FRI SEP 24 2021 298 FONT13 KNHC 240239 PWSAT3 TROPICAL STORM SAM WIND SPEED PROBABILITIES NUMBER 6 NWS NATIONAL HURRICANE CENTER MIAMI FL AL182021 0300 UTC FRI SEP 24 2021 AT 0300Z THE CENTER OF TROPICAL STORM SAM WAS LOCATED NEAR LATITUDE 11.2 NORTH...LONGITUDE 40.9 WEST WITH MAXIMUM SUSTAINED WINDS NEAR 60 KTS...70 MPH...110 KM/H. Z INDICATES COORDINATED UNIVERSAL TIME (GREENWICH) ATLANTIC STANDARD TIME (AST)...SUBTRACT 4 HOURS FROM Z TIME EASTERN DAYLIGHT TIME (EDT)...SUBTRACT 4 HOURS FROM Z TIME CENTRAL DAYLIGHT TIME (CDT)...SUBTRACT 5 HOURS FROM Z TIME WIND SPEED PROBABILITY TABLE FOR SPECIFIC LOCATIONS CHANCES OF SUSTAINED (1-MINUTE AVERAGE) WIND SPEEDS OF AT LEAST ...34 KT (39 MPH... 63 KM/H)... ...50 KT (58 MPH... 93 KM/H)... ...64 KT (74 MPH...119 KM/H)... FOR LOCATIONS AND TIME PERIODS DURING THE NEXT 5 DAYS PROBABILITIES FOR LOCATIONS ARE GIVEN AS OP(CP) WHERE OP IS THE PROBABILITY OF THE EVENT BEGINNING DURING AN INDIVIDUAL TIME PERIOD (ONSET PROBABILITY) (CP) IS THE PROBABILITY OF THE EVENT OCCURRING BETWEEN 00Z FRI AND THE FORECAST HOUR (CUMULATIVE PROBABILITY) PROBABILITIES ARE GIVEN IN PERCENT X INDICATES PROBABILITIES LESS THAN 1 PERCENT PROBABILITIES FOR 34 KT AND 50 KT ARE SHOWN AT A GIVEN LOCATION WHEN THE 5-DAY CUMULATIVE PROBABILITY IS AT LEAST 3 PERCENT. PROBABILITIES FOR 34...50...64 KT SHOWN WHEN THE 5-DAY 64-KT CUMULATIVE PROBABILITY IS AT LEAST 1 PERCENT. - - - - WIND SPEED PROBABILITIES FOR SELECTED LOCATIONS - - - - FROM FROM FROM FROM FROM FROM FROM TIME 00Z FRI 12Z FRI 00Z SAT 12Z SAT 00Z SUN 00Z MON 00Z TUE PERIODS TO TO TO TO TO TO TO 12Z FRI 00Z SAT 12Z SAT 00Z SUN 00Z MON 00Z TUE 00Z WED FORECAST HOUR (12) (24) (36) (48) (72) (96) (120) - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - LOCATION KT SAINT MAARTEN 34 X X( X) X( X) X( X) X( X) X( X) 3( 3) SABA 34 X X( X) X( X) X( X) X( X) X( X) 3( 3) ST EUSTATIUS 34 X X( X) X( X) X( X) X( X) X( X) 3( 3) ST KITTS-NEVIS 34 X X( X) X( X) X( X) X( X) X( X) 3( 3) BARBUDA 34 X X( X) X( X) X( X) X( X) X( X) 6( 6) ANTIGUA 34 X X( X) X( X) X( X) X( X) X( X) 5( 5) GUADELOUPE 34 X X( X) X( X) X( X) X( X) X( X) 6( 6) DOMINICA 34 X X( X) X( X) X( X) X( X) X( X) 5( 5) MARTINIQUE 34 X X( X) X( X) X( X) X( X) X( X) 5( 5) SAINT LUCIA 34 X X( X) X( X) X( X) X( X) X( X) 3( 3) BARBADOS 34 X X( X) X( X) X( X) X( X) 1( 1) 4( 5) $$ FORECASTER BERG
Tropical Storm Sam Forecast Advisory Number 6
2021-09-24 04:39:40| National Hurricane Center (Atlantic)
Issued at 0300 UTC FRI SEP 24 2021 660 WTNT23 KNHC 240239 TCMAT3 TROPICAL STORM SAM FORECAST/ADVISORY NUMBER 6 NWS NATIONAL HURRICANE CENTER MIAMI FL AL182021 0300 UTC FRI SEP 24 2021 THERE ARE NO COASTAL WATCHES OR WARNINGS IN EFFECT. TROPICAL STORM CENTER LOCATED NEAR 11.2N 40.9W AT 24/0300Z POSITION ACCURATE WITHIN 15 NM PRESENT MOVEMENT TOWARD THE WEST OR 280 DEGREES AT 13 KT ESTIMATED MINIMUM CENTRAL PRESSURE 997 MB MAX SUSTAINED WINDS 60 KT WITH GUSTS TO 75 KT. 50 KT....... 20NE 0SE 0SW 10NW. 34 KT....... 40NE 30SE 20SW 30NW. 12 FT SEAS.. 90NE 0SE 0SW 60NW. WINDS AND SEAS VARY GREATLY IN EACH QUADRANT. RADII IN NAUTICAL MILES ARE THE LARGEST RADII EXPECTED ANYWHERE IN THAT QUADRANT. REPEAT...CENTER LOCATED NEAR 11.2N 40.9W AT 24/0300Z AT 24/0000Z CENTER WAS LOCATED NEAR 11.1N 40.3W FORECAST VALID 24/1200Z 11.4N 42.9W MAX WIND 75 KT...GUSTS 90 KT. 64 KT... 15NE 0SE 0SW 10NW. 50 KT... 30NE 20SE 10SW 20NW. 34 KT... 50NE 40SE 20SW 40NW. FORECAST VALID 25/0000Z 11.8N 45.0W MAX WIND 90 KT...GUSTS 110 KT. 64 KT... 15NE 10SE 0SW 10NW. 50 KT... 30NE 20SE 10SW 20NW. 34 KT... 60NE 50SE 30SW 50NW. FORECAST VALID 25/1200Z 12.1N 46.6W MAX WIND 105 KT...GUSTS 130 KT. 64 KT... 20NE 15SE 10SW 15NW. 50 KT... 40NE 30SE 20SW 30NW. 34 KT... 70NE 60SE 40SW 60NW. FORECAST VALID 26/0000Z 12.5N 47.8W MAX WIND 110 KT...GUSTS 135 KT. 64 KT... 20NE 15SE 10SW 15NW. 50 KT... 40NE 30SE 20SW 30NW. 34 KT... 80NE 70SE 50SW 70NW. FORECAST VALID 26/1200Z 13.0N 49.1W MAX WIND 110 KT...GUSTS 135 KT. 50 KT... 50NE 40SE 30SW 40NW. 34 KT... 90NE 80SE 60SW 70NW. FORECAST VALID 27/0000Z 13.5N 50.4W MAX WIND 110 KT...GUSTS 135 KT. 50 KT... 50NE 40SE 30SW 40NW. 34 KT...100NE 80SE 60SW 80NW. EXTENDED OUTLOOK. NOTE...ERRORS FOR TRACK HAVE AVERAGED NEAR 150 NM ON DAY 4 AND 175 NM ON DAY 5...AND FOR INTENSITY NEAR 15 KT EACH DAY OUTLOOK VALID 28/0000Z 15.3N 53.2W MAX WIND 110 KT...GUSTS 135 KT. OUTLOOK VALID 29/0000Z 17.3N 56.1W MAX WIND 110 KT...GUSTS 135 KT. REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 11.2N 40.9W NEXT ADVISORY AT 24/0900Z $$ FORECASTER BERG
Tags: number
sam
storm
advisory
Sites : [43] [44] [45] [46] [47] [48] [49] [50] [51] [52] [53] [54] [55] [56] [57] [58] [59] [60] [61] [62] next »