je.st
news
Tag: discussion
Hurricane Teddy Forecast Discussion Number 40
2020-09-22 10:51:10| National Hurricane Center (Atlantic)
Issued at 500 AM AST Tue Sep 22 2020 851 WTNT45 KNHC 220850 TCDAT5 Hurricane Teddy Discussion Number 40 NWS National Hurricane Center Miami FL AL202020 500 AM AST Tue Sep 22 2020 Recent satellite imagery shows that the central convection is diminishing, with a comma-like cloud pattern developing. The current intensity is held at 85 kt based on continuity from the earlier aircraft mission. Another Hurricane Hunter aircraft is scheduled to investigate Teddy later today which should provide a good estimate of the intensity. Teddy is moving along the northern part of the Gulf Stream and should begin to move into cooler waters later today. Therefore weakening is expected over the next couple of days. However, baroclinic forcing should keep the cyclone at or near hurricane strength while it approaches Nova Scotia. The official intensity forecast is above the model consensus to qualitatively account for baroclinic effects. After 72 hours, or sooner, post-tropical Teddy should become absorbed or merge with a large extratropical low over the north Atlantic. Teddy has accelerated somewhat and is now moving north-northeastward near 24 kt. The hurricane is moving on the eastern side of a mid-tropospheric cyclone centered off the northeastern U.S. coast. Teddy should continue its north-northwestward motion today and then turn north-northeastward as the mid-tropospheric cyclone shifts northeastward. This will take post-tropical Teddy over Nova Scotia and near Newfoundland during the next couple of days. The official forecast is close to the corrected dynamical model consensus, or HFIP, and similar to the previous NHC track. The wind field of Teddy should continue to expand today and tonight, and the extent of 12-ft seas is also growing. See the Key Message regarding swells due to Teddy. Key Messages: 1. Teddy is expected to transition to a powerful post-tropical cyclone as it moves near or over portions of Atlantic Canada late today through Thursday, where direct impacts from wind, rain, and storm surge are expected. Tropical Storm Watches and Warnings are in effect for portions of Nova Scotia, Prince Edward Island and Newfoundland. 2. Very large swells produced by Teddy are expected to affect portions of Bermuda, the Leeward Islands, the Greater Antilles, the Bahamas, the east coast of the United States, and Atlantic Canada during the next few days. These swells are expected to cause life-threatening surf and rip current conditions. 3. Heavy rainfall across Atlantic Canada is expected with Teddy between today and Thursday after it becomes a strong post-tropical cyclone. FORECAST POSITIONS AND MAX WINDS INIT 22/0900Z 38.4N 62.4W 85 KT 100 MPH 12H 22/1800Z 40.9N 63.3W 75 KT 85 MPH 24H 23/0600Z 43.9N 62.9W 65 KT 75 MPH 36H 23/1800Z 47.5N 60.5W 55 KT 65 MPH...POST-TROP/EXTRATROP 48H 24/0600Z 52.0N 57.0W 45 KT 50 MPH...POST-TROP/EXTRATROP 60H 24/1800Z 57.0N 53.0W 40 KT 45 MPH...POST-TROP/EXTRATROP 72H 25/0600Z 61.0N 52.0W 35 KT 40 MPH...POST-TROP/EXTRATROP 96H 26/0600Z...DISSIPATED $$ Forecaster Pasch
Tags: number
discussion
forecast
hurricane
Hurricane Teddy Forecast Discussion Number 39
2020-09-22 04:48:25| National Hurricane Center (Atlantic)
Issued at 1100 PM AST Mon Sep 21 2020 000 WTNT45 KNHC 220248 TCDAT5 Hurricane Teddy Discussion Number 39 NWS National Hurricane Center Miami FL AL202020 1100 PM AST Mon Sep 21 2020 Air Force Reserve hurricane hunter found Teddy a little stronger this evening. Flight level peak wind was 111 kt in the east quadrant and the highest observed SFMR wind was 69 kt. A blend of these data yields an initial intensity of 85 kt for this advisory. Teddy is accelerating toward the north in response to a mid- to upper tropospheric mid-latitude trough approaching from the northwest. Dynamic forcing produced by the aforementioned baroclinic system and warm (27-28C) waters associated with the Gulf Stream could induce a short period of strengthening during the next few hours, or so. Through the remaining portion of the forecast period, Teddy will traverse cooler oceanic temperatures north of the Gulf Stream and lose its baroclinic support inducing a gradual weakening trend as the post-tropical cyclone quickly moves over eastern Nova Scotia, the Gulf of St. Lawrence and Newfoundland. After that time, Teddy should become absorbed by a larger non-tropical, high latitude low pressure system. There still remains much uncertainty as to whether or not Teddy will complete its extratropical transition prior to reaching Nova Scotia. The global models show the cyclone merged or embedded in the baroclinic zone, but the associated simulated infrared presentation shows Teddy maintaining a rather small warm, inner core. Regardless of it classification during that time, high winds, heavy rain, storm surge and destructive waves are still predicted for the south coast of Nova Scotia. Teddy's horizontal wind profile is forecast to nearly double during the next couple of days as it moves northward and interacts with the aforementioned baroclinic system. Gale-force winds are likely along portions of the near shore waters of the northeast United States. The forecast wind radii at the 24 hour period and beyond are based on the RVCN Wind Radii Consensus model that consists of a bias-corrected average of the global and regional models. Please see products from your local office for more information about marine hazards, including extremely dangerous rip currents expected over much of the western Atlantic beaches. Key Messages: 1. Teddy is expected to transition to a powerful post-tropical cyclone as it moves near or over portions of Atlantic Canada late Tuesday through Thursday, where direct impacts from wind, rain, and storm surge are expected. Tropical Storm Watches and Warnings are in effect for portions of Nova Scotia, Prince Edward Island and Newfoundland. 2. Very large swells produced by Teddy are expected to affect portions of Bermuda, the Leeward Islands, the Greater Antilles, the Bahamas, the east coast of the United States, and Atlantic Canada during the next few days. These swells are expected to cause life-threatening surf and rip current conditions. 3. Heavy rainfall across Atlantic Canada is expected with Teddy between Tuesday and Thursday after it becomes a strong post-tropical cyclone. FORECAST POSITIONS AND MAX WINDS INIT 22/0300Z 35.6N 61.5W 85 KT 100 MPH 12H 22/1200Z 38.4N 62.6W 85 KT 100 MPH 24H 23/0000Z 41.1N 63.1W 70 KT 80 MPH 36H 23/1200Z 44.6N 61.5W 60 KT 70 MPH 48H 24/0000Z 49.0N 58.7W 50 KT 60 MPH...POST-TROP/EXTRATROP 60H 24/1200Z 52.8N 54.8W 45 KT 50 MPH...POST-TROP/EXTRATROP 72H 25/0000Z 58.1N 51.4W 40 KT 45 MPH...POST-TROP/EXTRATROP 96H 26/0000Z...DISSIPATED $$ Forecaster Roberts
Tags: number
discussion
forecast
hurricane
Tropical Storm Beta Forecast Discussion Number 18
2020-09-22 04:47:24| National Hurricane Center (Atlantic)
Issued at 1000 PM CDT Mon Sep 21 2020 000 WTNT42 KNHC 220247 TCDAT2 Tropical Storm Beta Discussion Number 18 NWS National Hurricane Center Miami FL AL222020 1000 PM CDT Mon Sep 21 2020 There has been a recent increase in convection along the Texas coast just to the north of Beta's center this evening. A blend of flight-level and SFMR winds from an Air Force Reserve reconnaissance aircraft indicate that Beta's peak intensity remains around 40 kt. The aircraft has reported a minimum central pressure of around 999 mb, which is unchanged from earlier today. West-southwesterly vertical wind shear and land interaction should gradually weaken the cyclone over the next couple of days. The NHC intensity forecast is a little above model guidance through 24 hours since a significant portion of the circulation is forecast to remain over water. Strong vertical wind shear is expected to prevent re-strengthening when Beta moves near or just offshore of the Upper Texas coast in a couple of days. Beta is moving northwestward or 325/3 kt. The tropical storm should move just inland along the central Texas coast overnight, but it is expected to become nearly stationary on Tuesday as steering currents collapse. A weak trough over the south-central United States should begin to steer Beta east-northeastward Tuesday night and Wednesday, and a northeastward motion at a slightly faster forward speed should continue until dissipation in 72-96 hours. The latest NHC track forecast is very similar to the previous advisory and is a blend of the latest GFS and ECMWF models. Key Messages: 1. The expected slow motion of Beta will produce a long duration rainfall event from the middle Texas coast to southeast Louisiana. Flash, urban, and minor river flooding is likely. Rainfall will also spread northward into the ArkLaTex region and east into the Lower Mississippi Valley and portions of the Southeast through the end of the week. Flash, urban, and isolated minor river flooding is possible. 2. There is the danger of life-threatening storm surge near times of high tide through Tuesday along portions of the Texas and Louisiana coasts within the storm surge warning areas. Residents in these areas should follow advice given by local officials. 3. Tropical-storm-force winds will spread westward across the Texas coast through Tuesday. FORECAST POSITIONS AND MAX WINDS INIT 22/0300Z 28.4N 96.3W 40 KT 45 MPH 12H 22/1200Z 28.6N 96.3W 35 KT 40 MPH...INLAND 24H 23/0000Z 28.8N 96.0W 35 KT 40 MPH...INLAND 36H 23/1200Z 29.1N 95.0W 30 KT 35 MPH...OVER WATER 48H 24/0000Z 29.5N 93.8W 30 KT 35 MPH...OVER WATER 60H 24/1200Z 30.4N 92.3W 25 KT 30 MPH...INLAND 72H 25/0000Z 31.7N 90.7W 20 KT 25 MPH...POST-TROP/REMNT LOW 96H 26/0000Z...DISSIPATED $$ Forecaster Brown
Tags: number
discussion
beta
storm
Tropical Storm Paulette Forecast Discussion Number 40
2020-09-22 04:35:24| National Hurricane Center (Atlantic)
Issued at 300 AM GMT Tue Sep 22 2020 000 WTNT41 KNHC 220235 TCDAT1 Tropical Storm Paulette Discussion Number 40 NWS National Hurricane Center Miami FL AL172020 300 AM GMT Tue Sep 22 2020 Deep convection associated with the post-tropical remnants of Paulette that moved southward to the southwest of the Azores over the past few days has become better organized over the past 6-12 hours. An ASCAT over pass from a few hours ago indicate that increase in convective organization has result in strengthening and the system is being classified as a tropical cyclone once again. The ASCAT revealed peak winds of just over 45 kt, and given that instruments typical undersampling, the initial intensity is set at 50 kt. The scatterometer data also indicated a small radius of maximum winds of about 30 n mi, therefore the system is being classified as a tropical cyclone rather than subtropical. Paulette is moving east-northeastward or 075/14 kt. The tropical storm should continue moving east-northeastward ahead of a mid-latitude trough dropping southeastward over the northeastern Atlantic, and the global models are in reasonably good agreement through 24-36 hours. After that time, there is significant bifurcation in the track guidance with the GFS, HWRF, and HMON all taking a stronger Paulette faster east-northeastward over the eastern Atlantic, while the UKMET and ECMWF show a weaker cyclone slowing down and turning west-southwestward in the low-level steering flow late in the forecast period. The NHC track forecast shows Paulette slowing down and turning southward, and then southwestward between 48-96 h, but it's not nearly as far west as the UKMET and ECMWF models. Given the large spread in the track guidance at that time period, the NHC forecast is near the HFIP corrected consensus. Paulette is already over marginal SSTs and cooler waters lie ahead along the forecast track. This, along with moderate vertical wind shear should result in gradual weakening beginning on Tuesday. The NHC intensity forecast calls for Paulette to weaken to a tropical depression in 48-60 h, and become a remnant low shortly thereafter. FORECAST POSITIONS AND MAX WINDS INIT 22/0300Z 33.9N 25.3W 50 KT 60 MPH 12H 22/1200Z 34.4N 22.8W 50 KT 60 MPH 24H 23/0000Z 34.7N 20.4W 45 KT 50 MPH 36H 23/1200Z 35.1N 18.2W 40 KT 45 MPH 48H 24/0000Z 35.3N 16.8W 35 KT 40 MPH 60H 24/1200Z 34.7N 16.3W 30 KT 35 MPH...POST-TROP/REMNT LOW 72H 25/0000Z 34.0N 16.3W 25 KT 30 MPH...POST-TROP/REMNT LOW 96H 26/0000Z 33.1N 18.4W 25 KT 30 MPH...POST-TROP/REMNT LOW 120H 27/0000Z...DISSIPATED $$ Forecaster Brown
Tags: number
discussion
storm
tropical
Tropical Storm Lowell Forecast Discussion Number 6
2020-09-22 04:31:55| Tropical Depression LIDIA
Issued at 900 PM MDT Mon Sep 21 2020
Tags: number
discussion
storm
tropical
Sites : [173] [174] [175] [176] [177] [178] [179] [180] [181] [182] [183] [184] [185] [186] [187] [188] [189] [190] [191] [192] next »