Home › discussion
 

Keywords :   


Tag: discussion

Tropical Storm Lidia Forecast Discussion Number 14

2017-09-02 04:36:39| National Hurricane Center (East Pacific)

Issued at 900 PM MDT Fri Sep 01 2017 000 WTPZ44 KNHC 020236 TCDEP4 Tropical Storm Lidia Discussion Number 14 NWS National Hurricane Center Miami FL EP142017 900 PM MDT Fri Sep 01 2017 The terrain of the Baja California peninsula has taken a toll on Lidia. The cloud pattern has become disorganized, and deep convection has decreased with only a few strong patches remaining near the center. Based on tonight's satellite intensity estimates and continuity, the initial intensity is generously set at 45 kt. It appears that the strongest winds are occurring in the eastern half of the circulation and mainly over the Sea of Cortes. The interaction with land and cold waters will result in additional weakening, and Lidia is forecast to be a remnant low in about 24 to 36 hours or even sooner. Lidia has continued on a steady motion toward northwest or 320 degrees at 10 kt. The flow pattern resulting from a high over Mexico and a large low to the west will continue to steer Lidia northwestward for a day or two. Thereafter, Lidia is expected to be a shallow cyclone steered by the low-level easterly flow. The NHC forecast is very similar to the previous one and is close to the multi-model consensus. Despite weakening, the heavy rainfall threat will continue over northwestern Mexico and the Baja California peninsula during the next couple of days. Moisture from the cyclone could reach the southwestern United States over the weekend. FORECAST POSITIONS AND MAX WINDS INIT 02/0300Z 26.4N 112.9W 45 KT 50 MPH 12H 02/1200Z 27.6N 114.0W 35 KT 40 MPH...INLAND 24H 03/0000Z 29.0N 115.7W 30 KT 35 MPH...OVER WATER 36H 03/1200Z 30.0N 117.5W 25 KT 30 MPH...POST-TROP/REMNT LOW 48H 04/0000Z 31.5N 119.5W 20 KT 25 MPH...POST-TROP/REMNT LOW 72H 05/0000Z 33.0N 124.0W 20 KT 25 MPH...POST-TROP/REMNT LOW 96H 06/0000Z...POST-TROP/REMNT LOW $$ Forecaster Avila

Tags: number discussion storm tropical

 

Hurricane Irma Forecast Discussion Number 10

2017-09-01 22:50:37| National Hurricane Center (Atlantic)

Issued at 500 PM AST Fri Sep 01 2017 000 WTNT41 KNHC 012050 TCDAT1 Hurricane Irma Discussion Number 10 NWS National Hurricane Center Miami FL AL112017 500 PM AST Fri Sep 01 2017 Well, that eyewall replacement cycle didn't last long. Satellite images indicate that the cycle is now complete, with Irma displaying a larger warm eye. The initial wind speed has been set to 105 kt, in agreement with the CIMSS ADT. Since the eyewall cycle is finished, some strengthening is possible, although SSTs are currently pretty marginal. Although no increase in winds is shown in the short term, this could be conservative. During the next few days, water temperatures along the track will warm significantly, but there could be some higher shear, and of course more eyewall replacements. The forecast is a compromise between the statistical/dynamical models, which bring the intensity down then up again, versus the global models and hurricane models, which show a rather strong cyclone. The westward turn of Irma has begun, and the current motion is 275/12. A building mid-level high should cause the hurricane to turn west-southwestward tomorrow and continue through early next week. Later on, Irma should reach the southern periphery of the ridge, and begin to move west-northwestward. The biggest change since the last forecast is that the GFS and its ensemble has trended southwestward, toward the unwavering ECMWF model on the track forecast. Given the trend in guidance, little change is made to the official track prediction, although the corrected consensus models and the HWRF are now southwest of the latest forecast. KEY MESSAGES: 1. Irma is expected to be a major hurricane when it approaches the Lesser Antilles early next week, producing rough surf and rip currents. Irma could also cause dangerous wind, storm surge, and rainfall impacts on some islands, although it is too soon to specify where and when those hazards could occur. Residents in the Lesser Antilles should monitor the progress of Irma through the weekend and listen to any advice given by local officials. 2. It is much too early to determine what direct impacts Irma will have on the continental United States. Regardless, everyone in hurricane-prone areas should ensure that they have their hurricane plan in place, as we are now near the peak of the season. FORECAST POSITIONS AND MAX WINDS INIT 01/2100Z 18.8N 39.1W 105 KT 120 MPH 12H 02/0600Z 18.9N 40.9W 105 KT 120 MPH 24H 02/1800Z 18.5N 43.4W 105 KT 120 MPH 36H 03/0600Z 17.9N 45.7W 105 KT 120 MPH 48H 03/1800Z 17.2N 47.9W 105 KT 120 MPH 72H 04/1800Z 16.4N 52.2W 110 KT 125 MPH 96H 05/1800Z 17.0N 56.5W 110 KT 125 MPH 120H 06/1800Z 19.0N 61.0W 115 KT 130 MPH $$ Forecaster Blake

Tags: number discussion forecast hurricane

 
 

Tropical Storm Lidia Forecast Discussion Number 13

2017-09-01 22:35:38| National Hurricane Center (East Pacific)

Issued at 300 PM MDT Fri Sep 01 2017 000 WTPZ44 KNHC 012035 TCDEP4 Tropical Storm Lidia Discussion Number 13 NWS National Hurricane Center Miami FL EP142017 300 PM MDT Fri Sep 01 2017 The center of Lidia has been moving over the southern portion of the Baja California peninsula. While the convective cloud pattern has become somewhat ragged, a recent surface observation from Loreto, Mexico indicates that maximum sustained winds remain near 50 kt. The storm also continues to have a large wind field in the eastern semicircle as shown by a prolonged period of tropical- storm-force winds at Los Mochis on the Mexican mainland. Weakening is expected while the circulation interacts with the mountainous terrain of Baja California. However, tropical-storm- force winds will continue to extend well east of the center, riding up the peninsula and adjacent Gulf of California for about the next 24 hours. When Lidia emerges over the Pacific, it is expected to be over sea surface temperatures near or below 24C, which should cause it to quickly decay to a remnant low. The latest large-scale model guidance suggests that a circulation should persist through 96 h, possibly due to interaction with a nearby mid- to upper-level low late in the forecast period. Thus, a 96 h point has been included. The initial motion is now 325/10. Lidia remains between a mid-level high centered over the southwestern United States and the aforementioned mid- to upper-level trough to the southwest and south over the Pacific, and these features should keep the cyclone on a general northwestward course for the next 72 h or so, followed by a turn toward the west-northwest. The new forecast track has the center over or just off of the west coast of the Baja California peninsula for the next 18-24 h before emerging over the Pacific Ocean. Overall the new track is an update of the previous track that lies close to, but is slightly faster than, the various consensus models. While Lidia should weaken, the heavy rainfall threat will continue over northwestern Mexico and the Baja California peninsula during the next few days. Moisture from the cyclone could reach the southwestern United States over the weekend. FORECAST POSITIONS AND MAX WINDS INIT 01/2100Z 25.5N 111.9W 50 KT 60 MPH...INLAND 12H 02/0600Z 26.8N 113.0W 45 KT 50 MPH...INLAND 24H 02/1800Z 28.2N 114.6W 35 KT 40 MPH...OVER WATER 36H 03/0600Z 29.4N 116.4W 30 KT 35 MPH...POST-TROP/REMNT LOW 48H 03/1800Z 30.7N 118.3W 25 KT 30 MPH...POST-TROP/REMNT LOW 72H 04/1800Z 33.0N 123.0W 20 KT 25 MPH...POST-TROP/REMNT LOW 96H 05/1800Z 34.0N 127.0W 20 KT 25 MPH...POST-TROP/REMNT LOW 120H 06/1800Z...DISSIPATED $$ Forecaster Beven

Tags: number discussion storm tropical

 

Hurricane Irma Forecast Discussion Number 9

2017-09-01 16:50:34| National Hurricane Center (Atlantic)

Issued at 1100 AM AST Fri Sep 01 2017 000 WTNT41 KNHC 011450 TCDAT1 Hurricane Irma Discussion Number 9 NWS National Hurricane Center Miami FL AL112017 1100 AM AST Fri Sep 01 2017 Irma is undergoing an eyewall replacement cycle. The small eye is becoming less distinct, with both microwave and visible imagery indicating the presence of a forming outer eyewall. Satellite intensity estimates are lower, so the initial wind speed is reduced to 95 kt. Some further weakening is possible over the next day or so while Irma moves over marginally warm SSTs and continues the eyewall replacement. After that time, the environment should be generally conducive for some restrengthening, although forecasting the timing of eyewall replacement cycles is next to impossible. The biggest change from yesterday are the long-term wind shear predictions from the global models, which shows a little more shear. Still, the shear is not that strong, and the hurricane will be moving over 29C SSTs. Thus, the NHC intensity forecast is reduced somewhat from the previous one, but remains near or slightly above the model consensus. Irma has turned a little bit to the left, now estimated to be moving 285/11. The general synoptic situation remains well established due to a building mid-level high, which should cause the hurricane to turn westward later today and then move west-southwestward through the weekend. An upper-level low will be dropping southward on the east side of that high, and should be a key feature to how far south Irma goes before eventually turning westward and west-northwestward early next week. There is a noticeable clustering of guidance by day 5, with the ECMWF, HWRF and corrected-consensus models to the south, and the UKMET, GFS, CTC and HMON to the north. Since Irma is forecast to be a vertically deep cyclone, it seems more likely to respond to the northerly flow from the upper-level low, which leads me to believe the track will be on the southern side of the guidance. Thus, the forecast will stay similar to the previous one, very close to the southern cluster mentioned above. FORECAST POSITIONS AND MAX WINDS INIT 01/1500Z 18.5N 37.8W 95 KT 110 MPH 12H 02/0000Z 18.7N 39.5W 90 KT 105 MPH 24H 02/1200Z 18.5N 41.8W 90 KT 105 MPH 36H 03/0000Z 18.0N 44.2W 95 KT 110 MPH 48H 03/1200Z 17.3N 46.6W 100 KT 115 MPH 72H 04/1200Z 16.2N 51.0W 105 KT 120 MPH 96H 05/1200Z 16.7N 55.2W 110 KT 125 MPH 120H 06/1200Z 18.0N 59.5W 110 KT 125 MPH $$ Forecaster Blake

Tags: number discussion forecast hurricane

 

Tropical Storm Lidia Forecast Discussion Number 12

2017-09-01 16:50:34| National Hurricane Center (East Pacific)

Issued at 900 AM MDT Fri Sep 01 2017 000 WTPZ44 KNHC 011450 TCDEP4 Tropical Storm Lidia Discussion Number 12 NWS National Hurricane Center Miami FL EP142017 900 AM MDT Fri Sep 01 2017 Satellite imagery indicates that the center of Lidia has made landfall on the Baja California peninsula west of La Paz. The convective organization of the cyclone has decreased over the past several hours and, based on this and continuity from the previous advisory, the initial intensity is decreased to 50 kt. The storm continues to have a large wind field in the eastern semicircle as shown by a recent report of tropical-storm-force winds in Los Mochis on the Mexican mainland. The initial motion is 325/8. Lidia remains between a mid-level high centered over the southwestern United States and a mid-level trough southwest over the Pacific, and these features should keep Lidia on a general northwestward course for the next three days. The new forecast track has the center over or just off of the west coast of the Baja California peninsula for the next 30-36 h before emerging over the Pacific Ocean. Overall the new track is an update of the previous track that lies close to the various consensus models. Steady weakening is expected while the circulation interacts with the mountainous terrain of Baja California. However, tropical- storm-force winds will continue to extend well east of the center, riding up the peninsula and adjacent Gulf of California for at least the next 24 hours. When Lidia emerges over the Pacific, it is expected to be over sea surface temperatures near or below 24C, which should cause it to quickly decay to a remnant low. The new intensity forecast is also an update of the previous forecast and lies at the upper edge of the intensity guidance. While Lidia should steadily weaken, the heavy rainfall threat will continue over northwestern Mexico and the Baja California peninsula during the next few days. Moisture from the cyclone could reach the southwestern United States over the weekend. FORECAST POSITIONS AND MAX WINDS INIT 01/1500Z 24.6N 111.2W 50 KT 60 MPH...INLAND 12H 02/0000Z 25.8N 112.2W 45 KT 50 MPH...OVER WATER 24H 02/1200Z 27.4N 113.8W 40 KT 45 MPH...INLAND 36H 03/0000Z 28.6N 115.6W 35 KT 40 MPH...OVER WATER 48H 03/1200Z 29.9N 117.5W 30 KT 35 MPH...POST-TROP/REMNT LOW 72H 04/1200Z 32.5N 122.0W 20 KT 25 MPH...POST-TROP/REMNT LOW 96H 05/1200Z...DISSIPATED $$ Forecaster Beven

Tags: number discussion storm tropical

 

Sites : [698] [699] [700] [701] [702] [703] [704] [705] [706] [707] [708] [709] [710] [711] [712] [713] [714] [715] [716] [717] next »