Home discussion
 

Keywords :   


Tag: discussion

Tropical Storm Narda Forecast Discussion Number 3

2019-09-29 04:42:25| National Hurricane Center (East Pacific)

Issued at 1000 PM CDT Sat Sep 28 2019 000 WTPZ41 KNHC 290242 TCDEP1 Tropical Storm Narda Discussion Number 3 NWS National Hurricane Center Miami FL EP162019 1000 PM CDT Sat Sep 28 2019 Late afternoon visible satellite imagery and ship observations show that the disturbance's circulation has become better defined. In addition, there has been an increase in convective banding around the western portion of the system. As a result, the system is being classified as a tropical storm. The initial wind speed is maintained at 35 kt, which is in agreement with earlier scatterometer data, and the latest TAFB Dvorak classification. Narda is located within an area of moderate northeasterly shear and is likely to interact with the mountainous terrain of southern Mexico on Sunday. As a result, only slight strengthening is indicated within the next 24 hours, followed by some weakening as the system moves near or over the southwestern coast of Mexico. The latter portion of the intensity forecast is quite uncertain. If the system tracks to the right of the official forecast it would likely weaken and dissipate over southern Mexico, but if it remains farther west or just offshore, it could be stronger than indicated below. The tropical storm is moving northwestward at about 8 kt. A strong deep-layer ridge over the southeastern United States should continue to steer the disturbance northwestward during the next couple of days. The latest runs of the GFS and ECMWF both take the system inland within the next 24 hours, however the ensemble means favor a track near, but just offshore of the coast. The NHC forecast is similar to the previous advisory, but the confidence after 36-48 hours is quite low due to the potential land interaction. FORECAST POSITIONS AND MAX WINDS INIT 29/0300Z 15.4N 100.6W 35 KT 40 MPH 12H 29/1200Z 16.7N 101.6W 40 KT 45 MPH 24H 30/0000Z 18.3N 103.7W 40 KT 45 MPH 36H 30/1200Z 20.3N 105.7W 35 KT 40 MPH 48H 01/0000Z 22.2N 107.4W 40 KT 45 MPH 72H 02/0000Z 24.9N 109.5W 35 KT 40 MPH 96H 03/0000Z 25.5N 109.8W 25 KT 30 MPH 120H 04/0000Z 26.5N 110.0W 20 KT 25 MPH...POST-TROP/REMNT LOW $$ Forecaster Brown

Tags: number discussion storm tropical

 

Hurricane Lorenzo Forecast Discussion Number 27

2019-09-29 04:35:27| National Hurricane Center (Atlantic)

Issued at 1100 PM AST Sat Sep 28 2019 000 WTNT43 KNHC 290235 TCDAT3 Hurricane Lorenzo Discussion Number 27 NWS National Hurricane Center Miami FL AL132019 1100 PM AST Sat Sep 28 2019 Lorenzo has rapidly strengthened this evening. An eyewall replacement cycle completed earlier today, with a recent SSMIS microwave overpass showing that a new eyewall about 30 n mi in diameter now completely encircles the eye. The cold cloud tops surrounding the eye have expanded, with a solid ring of temperatures measuring colder than minus 70 degrees Celsius. In addition, the eye has cleared, with satellite derived cloud-top temperatures now above 15 degrees Celsius. Throughout the evening, the objective and subjective intensity estimates have climbed, with 0130 UTC special classifications from TAFB and SAB as well as a recent UW-CIMSS ADT estimate unanimously agreeing on a 140-kt initial intensity. This makes Lorenzo an extremely dangerous category 5 hurricane. The initial motion is now northward at 9 kt. Lorenzo will be steered north through a break between two subtropical ridges through tonight, with a turn to the north-northeast expected on Sunday. After Sunday, Lorenzo will begin to get caught up in increasing southwesterly flow ahead of an approaching mid-latitude trough. This will cause the cyclone to accelerate northeastward through the end of the forecast period. The official track forecast is essentially an update of the previous one, and is near the middle of the consensus aids. Lorenzo will likely peak in intensity overnight as it remains in the current favorable environment. Some fluctuations in intensity are possible on Sunday mainly due to eyewall replacement cycles. By Sunday night, Lorenzo will begin to feel the effects of some southwesterly shear ahead of the approaching trough, while it also moves over waters of lower oceanic heat content. These factors should induce a steady weakening trend through 48 hours. After that time, SSTs below 26 C should cause a faster weakening trend. By 72 hours, the cyclone will begin interacting with the approaching trough and an associated cold front, which will begin a transition to an extratropical low. This transition is forecast to complete by 120 hours, but it could happen a little sooner than that. The official forecast was increased through the first 48 hours due to the increase in initial intensity, and then blends to near the previous official forecast by 72 hours. With this latest advisory intensity, Lorenzo becomes the strongest hurricane in history this far north and east in the Atlantic basin. Key Messages: 1. Lorenzo is a large hurricane, and its hurricane- and tropical-storm-force wind fields are expected to expand further during the next several days. Regardless of Lorenzo's exact track near the Azores, strong winds are becoming increasingly likely on the islands Tuesday night and Wednesday, and residents there should monitor the progress of the hurricane. 2. Large swells generated by Lorenzo will continue to spread across much of the western and northern parts of the Atlantic basin during the next few days. These swells will produce life-threatening surf and rip currents. FORECAST POSITIONS AND MAX WINDS INIT 29/0300Z 24.2N 44.9W 140 KT 160 MPH 12H 29/1200Z 25.5N 44.7W 135 KT 155 MPH 24H 30/0000Z 27.1N 44.1W 125 KT 145 MPH 36H 30/1200Z 28.8N 43.3W 115 KT 130 MPH 48H 01/0000Z 30.8N 42.0W 105 KT 120 MPH 72H 02/0000Z 36.7N 35.3W 95 KT 110 MPH 96H 03/0000Z 45.0N 23.5W 75 KT 85 MPH 120H 04/0000Z 52.2N 10.7W 60 KT 70 MPH...POST-TROP/EXTRATROP $$ Forecaster Latto

Tags: number discussion forecast hurricane

 
 

Hurricane Lorenzo Forecast Discussion Number 26

2019-09-29 02:06:31| National Hurricane Center (Atlantic)

Issued at 800 PM AST Sat Sep 28 2019 000 WTNT43 KNHC 290006 TCDAT3 Hurricane Lorenzo Special Discussion Number 26 NWS National Hurricane Center Miami FL AL132019 800 PM AST Sat Sep 28 2019 The satellite presentation of Lorenzo has improved throughout this evening, and the ring of cloud tops surrounding the eye have become wider and colder. This has resulted in both subjective and objective satellite intensity estimates increasing to a 6.5 on the Dvorak scale, indicative of a 125 kt hurricane. Based on this data, a special advisory is being issued at this time to increase the initial intensity, and the 12-hour and 24-hour forecast wind speeds. No other changes were required to the previous track or intensity forecast. Key Messages: 1. Lorenzo is a large hurricane, and its hurricane- and tropical-storm-force wind fields are expected to expand further during the next several days. Regardless of Lorenzo's exact track near the Azores, strong winds are becoming increasingly likely on the islands Tuesday night and Wednesday, and residents there should monitor the progress of the hurricane. 2. Large swells generated by Lorenzo will continue to spread across much of the western and northern parts of the Atlantic basin during the next few days. These swells will produce life-threatening surf and rip currents. FORECAST POSITIONS AND MAX WINDS INIT 29/0000Z 23.8N 45.0W 125 KT 145 MPH 12H 29/0600Z 24.6N 44.8W 125 KT 145 MPH 24H 29/1800Z 26.3N 44.3W 110 KT 125 MPH 36H 30/0600Z 28.0N 43.7W 100 KT 115 MPH 48H 30/1800Z 29.7N 42.9W 95 KT 110 MPH 72H 01/1800Z 34.8N 38.0W 90 KT 105 MPH 96H 02/1800Z 42.5N 26.5W 75 KT 85 MPH 120H 03/1800Z 49.0N 13.0W 60 KT 70 MPH...POST-TROP/EXTRATROP $$ Forecaster Latto

Tags: number discussion forecast hurricane

 

Potential Tropical Cyclone Sixteen-E Forecast Discussion Number 2

2019-09-28 22:41:28| National Hurricane Center (East Pacific)

Issued at 400 PM CDT Sat Sep 28 2019 000 WTPZ41 KNHC 282041 TCDEP1 Potential Tropical Cyclone Sixteen-E Discussion Number 2 NWS National Hurricane Center Miami FL EP162019 400 PM CDT Sat Sep 28 2019 The large area of disturbed weather along the southwestern coast of Mexico has not been able to consolidate yet and still there is no evidence of a well-defined center. Satellite animation continue to suggest that a circulation could be forming just south of Acapulco, but it is still elongated. Latest ASCAT measured tropical-storm-force winds well south of the possible developing center. Since the large envelope of the disturbance is interacting with the high terrain of southern Mexico, and the environment is not ideal for strengthening, the NHC forecast calls for a very modest increase in winds. The disturbance could become a tropical storm at any time later tonight or Sunday before it reaches the coast. However, if the system survives the high terrain of the state of Jalisco, it could gather some additional strength when it emerges in the Gulf of California and before the shear increases. By the end of the forecast period, the shear is expected to be high, and a large portion of the circulation will be overland. This should result in weakening. The initial motion continues to be highly uncertain since the disturbance does not have a center good enough to track. However, a high pressure system over the Gulf of Mexico should continue to steer the disturbance or the cyclone toward the northwest and then north-northwest very close or over the southwestern coast of Mexico, and then into the Gulf of California. This is the solution provided by the reliable models. As mentioned this morning, If the system develops its center closer to the coast, there is a chance that the circulation moves inland earlier than anticipated resulting in faster weakening. In fact, this is the solution of this morning's GFS. Regardless of development, torrential rains are expected along the southwestern coast of Mexico during the next few days. FORECAST POSITIONS AND MAX WINDS INIT 28/2100Z 15.0N 100.0W 35 KT 40 MPH...POTENTIAL TROP CYCLONE 12H 29/0600Z 16.0N 101.0W 40 KT 45 MPH...TROPICAL STORM 24H 29/1800Z 18.0N 103.0W 40 KT 45 MPH 36H 30/0600Z 20.0N 105.5W 35 KT 40 MPH...INLAND 48H 30/1800Z 22.0N 107.0W 40 KT 45 MPH...OVER WATER 72H 01/1800Z 25.0N 109.0W 35 KT 40 MPH...OVER WATER 96H 02/1800Z 26.0N 109.5W 25 KT 30 MPH...INLAND 120H 03/1800Z 27.0N 110.0W 20 KT 25 MPH...POST-TROP/REMNT LOW $$ Forecaster Avila

Tags: number discussion potential tropical

 

Hurricane Lorenzo Forecast Discussion Number 25

2019-09-28 22:40:21| National Hurricane Center (Atlantic)

Issued at 500 PM AST Sat Sep 28 2019 000 WTNT43 KNHC 282040 TCDAT3 Hurricane Lorenzo Discussion Number 25 NWS National Hurricane Center Miami FL AL132019 500 PM AST Sat Sep 28 2019 A NOAA Hurricane Hunter aircraft conducting a research mission has been invaluable in helping us to observe reintensification after Lorenzo's eyewall replacement. The plane measured a peak 700-mb flight-level wind of 126 kt and SFMR surface winds as high as 112 kt. In addition, the latest UW-CIMSS SATCON estimate is 114 kt. These data support increasing the initial intensity to 115 kt, which makes Lorenzo a category 4 hurricane again. The plane also reported a circular eye 34 n mi wide and a central pressure around 950 mb. Lorenzo is moving northward, or 355/9 kt, through a gap in the subtropical ridge. The western Atlantic ridge is becoming stronger than the eastern Atlantic ridge, and this should help to nudge Lorenzo north-northeastward between 24-48 hours. After that period, a deep-layer trough over the north Atlantic should turn Lorenzo northeastward, with the hurricane's forward motion accelerating as it becomes embedded in the mid-latitude westerlies. The updated NHC track forecast has been placed near the HCCA model and the other consensus aids, which keeps it very close to the previous official forecast, at least through day 4. Some southward adjustment of the track was made at day 5 based on the latest global model guidance. Fluctuations in Lorenzo's intensity are possible over the next day or so. However, on the whole, moderate westerly shear and decreasing oceanic heat content ahead of the hurricane are expected to contribute to a very gradual weakening trend over the next 3 days. After day 3, Lorenzo is forecast to begin interacting with an approaching cold front from the northwest, which would start extratropical transition. The global models indicate that the transition should be complete soon after 96 hours, so for the moment the advisory continues to show tropical status on day 4. Faster weakening is expected during and after extratropical transition, and the updated NHC intensity forecast has been lowered slightly from the previous forecast on days 4 and 5. Key Messages: 1. Lorenzo is a large hurricane, and its hurricane- and tropical-storm-force wind fields are expected to expand further during the next several days. Regardless of Lorenzo's exact track near the Azores, strong winds are becoming increasingly likely on the islands Tuesday night and Wednesday, and residents there should monitor the progress of the hurricane. 2. Large swells generated by Lorenzo will continue to spread across much of the western and northern parts of the Atlantic basin during the next few days. These swells will produce life-threatening surf and rip currents. FORECAST POSITIONS AND MAX WINDS INIT 28/2100Z 23.3N 45.0W 115 KT 130 MPH 12H 29/0600Z 24.6N 44.8W 110 KT 125 MPH 24H 29/1800Z 26.3N 44.3W 105 KT 120 MPH 36H 30/0600Z 28.0N 43.7W 100 KT 115 MPH 48H 30/1800Z 29.7N 42.9W 95 KT 110 MPH 72H 01/1800Z 34.8N 38.0W 90 KT 105 MPH 96H 02/1800Z 42.5N 26.5W 75 KT 85 MPH 120H 03/1800Z 49.0N 13.0W 60 KT 70 MPH...POST-TROP/EXTRATROP $$ Forecaster Berg

Tags: number discussion forecast hurricane

 

Sites : [324] [325] [326] [327] [328] [329] [330] [331] [332] [333] [334] [335] [336] [337] [338] [339] [340] [341] [342] [343] next »