Home › discussion
 

Keywords :   


Tag: discussion

Tropical Storm Nadine Forecast Discussion Number 12

2018-10-12 04:54:20| National Hurricane Center (Atlantic)

Issued at 1100 PM AST Thu Oct 11 2018 000 WTNT45 KNHC 120254 TCDAT5 Tropical Storm Nadine Discussion Number 12 NWS National Hurricane Center Miami FL AL152018 1100 PM AST Thu Oct 11 2018 Although Nadine remains under the influence of strong southwesterly shear, a new burst of convection went up a few hours ago and covered the low-level center again. The initial intensity remains 45 kt based on consensus T3.0 Dvorak estimates from TAFB and SAB. Even stronger shear is expected to cause Nadine to weaken during the next day or two, and the global models all agree that the system will open up into a trough by 48 hours. The updated NHC forecast is unchanged from the previous one. Nadine is moving west-northwestward, or 295/8 kt. A low-level ridge is forecast to steer the cyclone west-northwestward and then westward at an increasing speed until it dissipates by 48 hours. The new track guidance has bended slightly southwestward on this cycle, and the updated NHC track forecast has been shifted in that direction toward the multi-model consensus aids and HCCA guidance. FORECAST POSITIONS AND MAX WINDS INIT 12/0300Z 14.9N 35.5W 45 KT 50 MPH 12H 12/1200Z 15.2N 36.6W 40 KT 45 MPH 24H 13/0000Z 15.6N 38.7W 35 KT 40 MPH 36H 13/1200Z 15.8N 41.5W 30 KT 35 MPH 48H 14/0000Z...DISSIPATED $$ Forecaster Berg

Tags: number discussion storm tropical

 

Tropical Storm Michael Forecast Discussion Number 22

2018-10-12 04:53:49| National Hurricane Center (Atlantic)

Issued at 1100 PM EDT Thu Oct 11 2018 000 WTNT44 KNHC 120253 TCDAT4 Tropical Storm Michael Discussion Number 22 NWS National Hurricane Center Miami FL AL142018 1100 PM EDT Thu Oct 11 2018 Michael has just about lost its tropical characteristics. The low-level circulation is becoming increasingly elongated as it becomes embedded within a frontal zone, and the center is becoming ill defined. The center we have been tracking across North Carolina appears to have moved into extreme southeastern Virginia, although it should be noted that a second low center, one with even lower pressure, has formed farther north along the western shore of Chesapeake Bay, closer to the deepest convection. Needless to say, Michael has just about become post-tropical, and that transformation should be complete overnight. The estimated maximum winds remain 45 kt based on recent observations from coastal North Carolina. Due to baroclinic forcing, some re-intensification of the post-tropical low is expected during the next 24-36 hours, following guidance from the Ocean Prediction Center. The post-tropical low should then begin to weaken again in 2-3 days and will likely be absorbed by another weather system to the west of Europe by day 4. The initial motion based on the continuity-following low center is northeastward, or 055/22 kt. Michael is embedded within the mid-latitude flow and is therefore expected to accelerate toward the east-northeast over the western and northern Atlantic during the next couple of days, even approaching speeds of about 50 kt in 48 hours. The track guidance remains tightly clustered, and no significant changes to the official track forecast were required. Michael's center is expected to move off the coast of Virginia within the next couple of hours, with tropical-storm- and gale-force winds moving away from the coast during the day on Friday. Gale- to storm-force winds are expected over portions of the Mid-Atlantic coast as Michael exits the U.S. east coast and becomes post-tropical. Non-tropical high wind watches, warnings, and advisories have been issued by local NWS offices for wind hazards in these areas north of Duck, North Carolina. Key Messages: 1. Life-threatening flash flooding is occurring over portions of the southern Mid-Atlantic states and will continue overnight. 2. Strong, possibly damaging winds are expected over portions of extreme eastern North Carolina, southeastern Virginia, and the southern Delmarva peninsula overnight. These winds have the potential to cause tree and structural damage, plus power outages. 3. Dangerous storm surge is possible overnight along the sound side of the North Carolina Outer Banks from Ocracoke Inlet to Duck, where a Storm Surge Watch is in effect. FORECAST POSITIONS AND MAX WINDS INIT 12/0300Z 37.1N 76.1W 45 KT 50 MPH 12H 12/1200Z 39.2N 71.2W 50 KT 60 MPH...POST-TROP/EXTRATROP 24H 13/0000Z 42.5N 61.5W 60 KT 70 MPH...POST-TROP/EXTRATROP 36H 13/1200Z 45.4N 49.0W 60 KT 70 MPH...POST-TROP/EXTRATROP 48H 14/0000Z 47.1N 34.8W 55 KT 65 MPH...POST-TROP/EXTRATROP 72H 15/0000Z 47.6N 14.6W 45 KT 50 MPH...POST-TROP/EXTRATROP 96H 16/0000Z...DISSIPATED $$ Forecaster Berg

Tags: number discussion michael storm

 
 

Tropical Storm Sergio Forecast Discussion Number 51

2018-10-12 04:50:45| National Hurricane Center (East Pacific)

Issued at 800 PM PDT Thu Oct 11 2018 000 WTPZ41 KNHC 120250 TCDEP1 Tropical Storm Sergio Discussion Number 51 NWS National Hurricane Center Miami FL EP212018 800 PM PDT Thu Oct 11 2018 Deep convection has been on the wane with Sergio during the past several hours with a relatively small patch remaining in the northern semicircle. Still, the circulation of Sergio is fairly large and vigorous and will take some time to spin down. The initial wind speed is held at 50 kt, on the high side of the satellite estimates since we haven't had ASCAT data in quite some time. Weakening should commence overnight due to cool waters and increasing shear. Sergio, however, is expected to still be a tropical storm when it moves over the Baja California peninsula on Friday. Thereafter, it should weaken faster while it interacts with the high terrain, then reaching the state of Sonora as a tropical depression and dissipating soon thereafter. Sergio continues moving northeastward at 20 kt. Models are very tightly clustered on this track and speed, staying virtually unchanged until dissipation by 36 hours or so. Note that the 36-hour point is merely a place holder for the remnants of the cyclone. No significant changes were made to the previous forecast. The primary threat associated with Sergio and its remnants continues to be life-threatening flash flooding and mudslides within mountainous terrain in the Mexico states of Baja California Sur, Sonora, the U.S. Southern Plains, and Arkansas through the weekend. For more information about this potential hazard, see products from the Weather Prediction Center and your local weather forecast office. FORECAST POSITIONS AND MAX WINDS INIT 12/0300Z 24.7N 115.4W 50 KT 60 MPH 12H 12/1200Z 26.7N 113.0W 40 KT 45 MPH...INLAND 24H 13/0000Z 29.6N 109.3W 25 KT 30 MPH...INLAND 36H 13/1200Z 32.5N 105.0W 15 KT 15 MPH...POST-TROP/REMNT LOW 48H 14/0000Z...DISSIPATED $$ Forecaster Blake

Tags: number discussion storm tropical

 

Hurricane Leslie Forecast Discussion Number 63

2018-10-12 04:42:45| National Hurricane Center (Atlantic)

Issued at 1100 PM AST Thu Oct 11 2018 000 WTNT43 KNHC 120242 TCDAT3 Hurricane Leslie Discussion Number 63 NWS National Hurricane Center Miami FL AL132018 1100 PM AST Thu Oct 11 2018 Satellite images indicate that Leslie has continued to strengthen. A small eye has occasionally been apparent, although it has recently become obscured by clouds. ASCAT data showed peak winds of 75 kt earlier, and given the low bias of that instrument at those wind speeds, the initial wind speed is set to 80 kt. Leslie should begin to weaken in about 24 hours as the hurricane encounters cool waters and a higher-shear environment. Intensity guidance is tightly clustered around the previous NHC prediction, and little change is made in the new advisory. By 72 hours, a combination of very dry air aloft, waters near 23.5C, and high shear should cause Leslie to lose convection and transition into a post-tropical cyclone. Leslie continues to accelerate east-northeastward with an initial motion estimate of 070/23 kt. The hurricane should move rapidly in that general direction for the next day or so ahead of a mid-latitude trough, then bend eastward and southward as the main steering mechanism switches to the eastern Atlantic subtropical ridge. There is still a large guidance spread, over 700 miles at day 3, but the main change to report is that more of the models are continuing the east-northeastward track longer, possibly due to Leslie becoming a stronger system. The official forecast is shifted to the east, but is still well to the southwest of the model consensus, ironically similar to last night's forecast. Leslie is a fairly large tropical cyclone and the forecast wind radii encompass Madeira Island within 36 hours. Consequently, a tropical storm warning has been issued for that island. It is the first known tropical storm warning for that place, and there are no known tropical storms in the historical record anywhere within 100 miles of that island, with the closest being Vince of 2005. FORECAST POSITIONS AND MAX WINDS INIT 12/0300Z 30.9N 33.9W 80 KT 90 MPH 12H 12/1200Z 32.1N 29.8W 80 KT 90 MPH 24H 13/0000Z 33.3N 23.5W 75 KT 85 MPH 36H 13/1200Z 34.0N 18.0W 65 KT 75 MPH 48H 14/0000Z 33.5N 15.5W 55 KT 65 MPH 72H 15/0000Z 31.5N 15.0W 35 KT 40 MPH...POST-TROPICAL 96H 16/0000Z 29.0N 18.0W 30 KT 35 MPH...POST-TROP/REMNT LOW 120H 17/0000Z 28.0N 24.0W 25 KT 30 MPH...POST-TROP/REMNT LOW $$ Forecaster Blake

Tags: number discussion forecast hurricane

 

Tropical Storm Michael Forecast Discussion Number 21

2018-10-11 22:53:47| National Hurricane Center (Atlantic)

Issued at 500 PM EDT Thu Oct 11 2018 000 WTNT44 KNHC 112053 TCDAT4 Tropical Storm Michael Discussion Number 21 NWS National Hurricane Center Miami FL AL142018 500 PM EDT Thu Oct 11 2018 Satellite and radar data show that Michael's rain shield is beginning to expand northward and northwestward, and that cooler and drier air is starting to wrap around the western portion of the circulation. These trends indicate that Michael's transition to an extratropical low has started. There have been recent observations of 40 to nearly 45 kt sustained winds along the southeastern coast of North Carolina, so the initial intensity remains 45 kt. Little change in strength is expected through this evening, but Michael is forecast to quickly intensify after it completes extratropical transition and exits the east coast of the United States tonight. The official intensity forecast is based on guidance from the NOAA Ocean Prediction Center. It should also be noted that an area of damaging wind gusts of up to 50 kt has developed around the northwest side of the circulation over central North Carolina and Virginia this afternoon. As a result, the gust factor has been increased in this advisory, as this area of strong winds will spread northward and eastward across portions of eastern Virginia and northeastern North Carolina this evening and tonight. Michael is moving northeastward or 050/21 kt. The storm will continue to accelerate as it become further embedded within the mid-latitude westerlies. The post-tropical cyclone will race across the north Atlantic during the next few days, before slowing down late in the period before it weakens and dissipates. The track guidance continues to be in good agreement and little change was required from the previous NHC track forecast. Gale- to storm-force winds are expected over portions of the Mid-Atlantic coast as Michael exits the U.S. east coast and becomes post-tropical. Non-tropical high wind watches, warnings, and advisories have been issued by local NWS offices for wind hazards in these areas north of Duck, North Carolina. Key Messages: 1. Life-threatening flash flooding is occurring over portions of North Carolina and southern Virginia and will continue through the evening. 2. Damaging winds are spreading eastward across portions of central and eastern North Carolina, and will continue through this evening. These winds have the potential to cause tree and structural damage. Strong winds are also expected over portions of southeastern Virginia and the Virginia Eastern Shore tonight as Michael becomes post-tropical. 3. Dangerous storm surge is possible tonight along the sound side of the North Carolina Outer Banks from Ocracoke Inlet to Duck, where a Storm Surge Watch is in effect. FORECAST POSITIONS AND MAX WINDS INIT 11/2100Z 36.1N 78.8W 45 KT 50 MPH...INLAND 12H 12/0600Z 38.1N 74.7W 45 KT 50 MPH...POST-TROP/EXTRATROP 24H 12/1800Z 41.2N 66.5W 60 KT 70 MPH...POST-TROP/EXTRATROP 36H 13/0600Z 44.5N 55.5W 60 KT 70 MPH...POST-TROP/EXTRATROP 48H 13/1800Z 47.0N 42.0W 60 KT 70 MPH...POST-TROP/EXTRATROP 72H 14/1800Z 48.5N 17.5W 50 KT 60 MPH...POST-TROP/EXTRATROP 96H 15/1800Z 46.5N 7.0W 30 KT 35 MPH...POST-TROP/EXTRATROP 120H 16/1800Z...DISSIPATED $$ Forecaster Brown

Tags: number discussion michael storm

 

Sites : [452] [453] [454] [455] [456] [457] [458] [459] [460] [461] [462] [463] [464] [465] [466] [467] [468] [469] [470] [471] next »