Home › discussion
 

Keywords :   


Tag: discussion

Tropical Storm Elsa Forecast Discussion Number 3

2021-07-01 10:54:36| National Hurricane Center (Atlantic)

Issued at 500 AM AST Thu Jul 01 2021 000 WTNT45 KNHC 010854 TCDAT5 Tropical Storm Elsa Discussion Number 3 NWS National Hurricane Center Miami FL AL052021 500 AM AST Thu Jul 01 2021 The tropical cyclone's cloud pattern became a little better organized overnight, with convective banding features becoming more evident over the western and southwestern portions of the circulation. Upper-level outflow is well-defined to the west of the system, and restricted over the eastern semicircle. The current intensity is set at 35 kt in agreement with Dvorak estimates from SAB and TAFB, and just slightly above the maximum winds from an earlier scatterometer pass, making the cyclone a tropical storm. Elsa is the earliest-known fifth named storm on record for the Atlantic basin in the satellite era (1966-present), breaking the record formerly held by Edouard on July 6, 2020. The storm has been accelerating westward overnight, and the initial motion is around 275/22 kt. A strong subtropical ridge is situated to the north of the storm, and this feature should steer the system quickly to the west-northwest for the next 3 days or so. There is significant uncertainty in the track forecast from days 3-5. The ECMWF model turns the cyclone northward after interacting with Hispaniola while the other models such as the GFS, HWRF, and U.K. Met take Elsa across western Cuba and into the southeastern Gulf of Mexico. The official forecast is similar to the previous one, and within the latter suite of guidance. However the discrepancy in the models makes confidence in this track lower than usual. Some intensification is likely for the next day or two, since Elsa is expected to be in an environment of warm sea-surface temperatures, fairly low vertical wind shear, and high mid-level relative humidity. However, the fast forward motion could result in some decoupling of the low- and higher-level circulation which would limit strengthening. Also, the potential interaction of the storm with the mountainous land masses of the Greater Antilles later in the forecast period could disrupt the circulation somewhat. Therefore the official intensity forecast, like the previous one, is quite conservative and on the lower end of the guidance suite. Key Messages: 1. Tropical storm conditions are expected beginning early Friday in portions of the Windward and southern Leeward Islands. 2. Heavy rainfall from the system will move quickly across the Windward and southern Leeward Islands, including Barbados, on Friday. Isolated flash flooding and mudslides are possible. 3. There is a risk of wind and rainfall impacts in portions of the Virgin Islands, Puerto Rico, Hispaniola, Cuba, the Turks and Caicos and the southeastern Bahamas through early next week. Interests in these areas should monitor the system's progress and updates to the forecast. 4. Interests in Florida should monitor updates to the forecast for this system, but it is too soon to determine what if any impacts could occur there next week given the uncertainty in the long-range forecast. FORECAST POSITIONS AND MAX WINDS INIT 01/0900Z 9.4N 48.8W 35 KT 40 MPH 12H 01/1800Z 10.3N 52.0W 40 KT 45 MPH 24H 02/0600Z 11.7N 56.7W 50 KT 60 MPH 36H 02/1800Z 13.2N 61.8W 50 KT 60 MPH 48H 03/0600Z 14.9N 66.9W 55 KT 65 MPH 60H 03/1800Z 16.7N 71.2W 55 KT 65 MPH 72H 04/0600Z 18.0N 74.5W 50 KT 60 MPH 96H 05/0600Z 21.0N 79.5W 50 KT 60 MPH 120H 06/0600Z 24.5N 82.0W 55 KT 65 MPH $$ Forecaster Pasch

Tags: number discussion storm tropical

 

Tropical Depression Five Forecast Discussion Number 2

2021-07-01 04:55:27| National Hurricane Center (Atlantic)

Issued at 1100 PM AST Wed Jun 30 2021 000 WTNT45 KNHC 010255 TCDAT5 Tropical Depression Five Discussion Number 2 NWS National Hurricane Center Miami FL AL052021 1100 PM AST Wed Jun 30 2021 The satellite presentation of the system over the last 6-12 hours has continued to gradually improve, with a prominent banding feature to the west of the estimated center. An ASCAT-A pass received at 2323 UTC revealed that the low-level circulation has become a bit better defined compared to earlier today, though still somewhat elongated to the south and west. The peak wind retrievals from this instrument were 30-32 kt. While subjective satellite estimates from TAFB and SAB were a bit higher, the latest estimated intensity was held at 30 kt for this advisory in agreement with the slightly lower scatterometer data. The initial motion has accelerated a bit tonight at 280/20 kt. A strong subtropical ridge is situated poleward of the tropical depression and this feature should steer the system quickly to the west-northwest over the next several days. After 72 hours, the tropical cyclone will reach the westward extent of the ridge and begin to move more poleward and slow down as the ridge also becomes eroded by a mid-latitude trough to over the eastern US. The track guidance in the latter portion of the forecast continues to exhibit large spread, with the GFS and HWRF/HMON models along the left side of the guidance envelop, while the ECMWF and its ensemble mean on the right side. The latest NHC track forecast is a shade right of the previous one, and also slightly faster, but given the spread in the models, the latter portion of the track is more uncertain than usual. While the depression is currently in a favorable environment of low vertical wind shear, warm sea-surface temperatures, and high mid-level relative humidity, the expected acceleration in forward motion could cause the system to outrun the favorable upper-level easterlies currently overhead, after 36 hours. In addition, the system could be near or over some of the Greater Antilles in the latter portions of the forecast. For these reasons, the intensity remained capped at 50 kt after 36 hours, and is still on the lower end of the intensity guidance suite, though this forecast could be somewhat conservative. Key Messages: 1. The tropical depression is expected to become a tropical storm before reaching the Lesser Antilles and tropical storm conditions are expected beginning late Thursday night in portions of the Windward and southern Leeward Islands. 2. Heavy rainfall will move quickly across the Windward and southern Leeward Islands, including Barbados, on Friday. Isolated flash flooding and mudslides are possible. 3. There is a risk of wind and rainfall impacts in portions of the Virgin Islands, Puerto Rico, Hispaniola, Cuba, the Turks and Caicos and the southeastern Bahamas through early next week. Interests in these areas should monitor the system's progress and updates to the forecast. 4. Interests in Florida should monitor updates to the forecast for this system, but it is too soon to determine what if any impacts could occur there next week given the uncertainty in the long-range forecast. FORECAST POSITIONS AND MAX WINDS INIT 01/0300Z 9.6N 46.3W 30 KT 35 MPH 12H 01/1200Z 10.5N 49.6W 40 KT 45 MPH 24H 02/0000Z 11.7N 54.4W 45 KT 50 MPH 36H 02/1200Z 13.0N 59.6W 50 KT 60 MPH 48H 03/0000Z 14.7N 65.0W 50 KT 60 MPH 60H 03/1200Z 16.5N 69.8W 50 KT 60 MPH 72H 04/0000Z 18.3N 73.8W 50 KT 60 MPH...NEAR THE COAST 96H 05/0000Z 20.9N 78.6W 50 KT 60 MPH...NEAR THE COAST 120H 06/0000Z 24.5N 82.0W 50 KT 60 MPH...OVER WATER $$ Forecaster Papin/Brown

Tags: number discussion tropical depression

 
 

Potential Tropical Cyclone Five Forecast Discussion Number 1

2021-06-30 22:54:51| National Hurricane Center (Atlantic)

Issued at 500 PM AST Wed Jun 30 2021 000 WTNT45 KNHC 302054 TCDAT5 Potential Tropical Cyclone Five Discussion Number 1 NWS National Hurricane Center Miami FL AL052021 500 PM AST Wed Jun 30 2021 Satellite imagery indicates that the convection associated with the low pressure area over the central tropical Atlantic is becoming better organized. However, earlier scatterometer data showed that the circulation was elongated and not well defined. Since the system is about 48 h away from the Lesser Antilles and is expected to become a tropical storm before reaching the islands, advisories are being initiated at this time on Potential Tropical Cyclone Five. The initial intensity is set to 30 kt based on the scatterometer data and satellite intensity estimates from TAFB and SAB. The initial motion is 285/18. The disturbance is currently on the south side of a strong subtropical ridge, and for the next 72 h the system should move rapidly west-northwestward. Indeed, the forward speed may exceed 25 kt as the system moves through the Lesser Antilles. There is excellent agreement in the guidance on this part of the forecast track. After 72 h, the system is expected to approach a weakness in the ridge caused by a mid-latitude trough over the eastern United States. The should cause the system to slow its forward speed and turn more northwestward. The track guidance become more diverse during this time in regards to how far north the system will turn, and this part of the NHC forecast track is most similar to the GFS and UKMET forecasts. Note that the track forecast is more uncertain than usual since the system does not yet have a well-defined center. The disturbance is currently in a favorable upper-level wind pattern. However, most Atlantic systems in this area moving near 25 kt have trouble strengthening, and there are indications that the fast forward speed may produce some westerly shear. Thus, the NHC intensity forecast for the first 72 h is near the lower edge of the intensity guidance. After 72 h, the intensity forecast becomes highly uncertain due to possible land interaction and differences in the model forecasts of the upper-level winds. This portion of the NHC intensity forecast maintains a constant 50-kt intensity due to the level of uncertainty. Key Messages: 1. The system is expected to become a tropical storm before reaching the Lesser Antilles and tropical storm conditions are possible beginning Friday in portions of the Windward and southern Leeward Islands. 2. Heavy rainfall will move quickly across the Windward and southern Leeward Islands, including Barbados, on Friday. Isolated flash flooding and mudslides are possible. 3. There is a risk of wind and rainfall impacts in portions of the Virgin Islands, Puerto Rico, Hispaniola, Cuba, the Turks and Caicos and the southeastern Bahamas through early next week, although the forecast is more uncertain than usual since the system does not have a well-defined center. Interests in these areas should monitor the system's progress and updates to the forecast. 4. Interests in Florida should monitor updates to the forecast for this system, but it is too soon to determine what if any impacts could occur there next week given the uncertainty in the long-range forecast. FORECAST POSITIONS AND MAX WINDS INIT 30/2100Z 9.6N 43.7W 30 KT 35 MPH...POTENTIAL TROP CYCLONE 12H 01/0600Z 10.2N 46.6W 35 KT 40 MPH...TROPICAL CYCLONE 24H 01/1800Z 11.1N 51.0W 40 KT 45 MPH 36H 02/0600Z 12.4N 56.0W 45 KT 50 MPH 48H 02/1800Z 13.8N 61.2W 45 KT 50 MPH 60H 03/0600Z 15.4N 66.3W 50 KT 60 MPH 72H 03/1800Z 17.0N 70.9W 50 KT 60 MPH 96H 04/1800Z 20.0N 77.0W 50 KT 60 MPH...INLAND 120H 05/1800Z 22.5N 81.5W 50 KT 60 MPH...INLAND $$ Forecaster Beven

Tags: number discussion potential tropical

 

Remnants of Enrique Forecast Discussion Number 23

2021-06-30 22:36:17| National Hurricane Center (East Pacific)

Issued at 300 PM MDT Wed Jun 30 2021 000 WTPZ45 KNHC 302036 TCDEP5 Remnants Of Enrique Discussion Number 23 NWS National Hurricane Center Miami FL EP052021 300 PM MDT Wed Jun 30 2021 Enrique has been devoid of deep, organized convection for over 12 hours today. In addition, visible satellite imagery and earlier passive microwave data suggested that the original center has been absorbed by a broad trough of low pressure centered farther southeast near the coast of Baja California Sur. Therefore, this will be the final NHC advisory on the remnants of Enrique. The remnant trough is expected to move west-northwestward over Baja California Sur tonight. Key Messages: 1. Swells generated by Enrique will affect portions of the western coast of Mexico and the coast of Baja California Sur during the next day or so. These swells are likely to cause life-threatening surf and rip current conditions. Please consult products from your local weather office. FORECAST POSITIONS AND MAX WINDS INIT 30/2100Z 24.5N 110.3W 20 KT 25 MPH 12H 01/0600Z...DISSIPATED $$ Forecaster Reinhart/Brown

Tags: number discussion forecast enrique

 

Tropical Depression Enrique Forecast Discussion Number 22

2021-06-30 16:39:50| National Hurricane Center (East Pacific)

Issued at 900 AM MDT Wed Jun 30 2021 000 WTPZ45 KNHC 301439 TCDEP5 Tropical Depression Enrique Discussion Number 22 NWS National Hurricane Center Miami FL EP052021 900 AM MDT Wed Jun 30 2021 After a brief burst of convection near its center overnight, the satellite presentation of Enrique has degraded this morning. Infrared cloud top temperatures have rapidly warmed near the estimated center position, and the only active convection at this time is occurring over the Baja California Peninsula. Overnight satellite-derived wind data supported winds of 25 to 30 kt in the northeast quadrant of the cyclone, and satellite trends suggest Enrique has weakened since then. Additionally, TAFB gave the system a T2.0 subjective Dvorak classification. Therefore, the initial intensity is lowered to 30 kt this morning, which downgrades Enrique to a tropical depression. Enrique is currently moving northwestward, although it is expected to turn slightly more west-northwestward later today between a weak ridge to its northeast and a low- to mid-level low pressure system well offshore. The track guidance remains in good agreement, and the official NHC forecast lies close to the multi-model consensus. Increasing vertical wind shear and drier mid-level air in the surrounding environment, as well as increasing land interaction, should support continued weakening during the next day or so. As expected, simulated satellite imagery from the GFS and ECMWF do not indicate much potential for additional convective development before the system moves inland tonight. Therefore, Enrique is forecast to become a remnant low over Baja California Sur by Thursday and dissipate shortly thereafter. Key Messages: 1. Heavy rains associated with Enrique are possible across southern portions of Baja California Sur. This will pose a threat of flash flooding and mudslides. 2. Swells generated by Enrique will affect portions of the western coast of Mexico and the coast of Baja California Sur during the next day or so. These swells are likely to cause life-threatening surf and rip current conditions. Please consult products from your local weather office. FORECAST POSITIONS AND MAX WINDS INIT 30/1500Z 24.6N 110.0W 30 KT 35 MPH 12H 01/0000Z 25.0N 110.8W 25 KT 30 MPH...INLAND 24H 01/1200Z 25.4N 111.7W 20 KT 25 MPH...POST-TROP/INLAND 36H 02/0000Z...DISSIPATED $$ Forecaster Reinhart/Beven

Tags: number discussion tropical depression

 

Sites : [97] [98] [99] [100] [101] [102] [103] [104] [105] [106] [107] [108] [109] [110] [111] [112] [113] [114] [115] [116] next »