Home discussion
 

Keywords :   


Tag: discussion

Hurricane Dorian Forecast Discussion Number 44

2019-09-04 10:55:35| National Hurricane Center (Atlantic)

Issued at 500 AM EDT Wed Sep 04 2019 000 WTNT45 KNHC 040855 TCDAT5 Hurricane Dorian Discussion Number 44 NWS National Hurricane Center Miami FL AL052019 500 AM EDT Wed Sep 04 2019 NOAA Doppler radar data and reports from an Air Force Reserve Unit Hurricane Hunter aircraft indicate that Dorian's eye has become broad and less well-defined over the past several hours. The hurricane is still producing some healthy bands of deep convection that are causing winds of at least tropical storm force along portions of the northeast coast of Florida. Although the central pressure had been rising, recent observations from the Hurricane Hunters show that it has leveled off near 963 mb. The current intensity is set at 90 kt, which may be generous considering the flight-level wind speeds reported by the aircraft. Dorian will be traversing warm waters for the next couple of days, with some increase in vertical shear after 24 hours. The official intensity forecast maintains the current intensity for a day or so and then shows a very slow weakening thereafter. This is close to the latest statistical-dynamical guidance. The system is expected to maintain close to category 2 strength until it passes near or over the North Carolina Outer Banks. Dorian is moving slowly north-northwestward to northwestward, or 330/7 kt. There is basically no change to the track forecast reasoning. Over the next day or so, the hurricane is forecast to gradually turn toward the north as it moves through a break in the subtropical ridge. Thereafter, Dorian should accelerate north-northeastward to northeastward on the southern side of a broad mid-latitude trough. The official forecast track remains close to the corrected multi-model consensus. Since the NHC track prediction continues to take Dorian dangerously close to the southeast U.S. coast, all interests from northeast Florida to the Carolinas should remain vigilant to the possibility of experiencing destructive winds, flooding rains, and life-threatening storm surges from this hurricane. Key Messages: 1. Life-threatening storm surge and dangerous winds are expected along portions of the Florida east coast and the coasts of Georgia, South Carolina, and North Carolina, regardless of the exact track of Dorian's center. Water levels could rise well in advance of the arrival of strong winds. Residents in these areas should follow advice given by local emergency officials. 2. The risk of wind and rain impacts along portions of the Virginia coast and the southern Chesapeake Bay are increasing. Residents in these areas should continue to monitor the progress of Dorian. 3. The flash flood threat will spread up the southeast U.S. coast today and Thursday, then across the coastal Mid-Atlantic region on Friday. There is a high risk of flash flooding on Thursday across coastal sections from northeast South Carolina into southern North Carolina. FORECAST POSITIONS AND MAX WINDS INIT 04/0900Z 29.2N 79.5W 90 KT 105 MPH 12H 04/1800Z 30.1N 79.8W 90 KT 105 MPH 24H 05/0600Z 31.2N 80.0W 90 KT 105 MPH 36H 05/1800Z 32.2N 79.4W 85 KT 100 MPH 48H 06/0600Z 33.7N 77.7W 80 KT 90 MPH 72H 07/0600Z 38.0N 70.6W 75 KT 85 MPH 96H 08/0600Z 45.0N 61.5W 70 KT 80 MPH...POST-TROP/EXTRATROP 120H 09/0600Z 53.5N 50.0W 60 KT 70 MPH...POST-TROP/EXTRATROP $$ Forecaster Pasch

Tags: number discussion forecast hurricane

 

Tropical Storm Gabrielle Forecast Discussion Number 3

2019-09-04 10:54:34| National Hurricane Center (Atlantic)

Issued at 500 AM AST Wed Sep 04 2019 000 WTNT43 KNHC 040854 TCDAT3 Tropical Storm Gabrielle Discussion Number 3 NWS National Hurricane Center Miami FL AL082019 500 AM AST Wed Sep 04 2019 A late-arriving ASCAT-C scatterometer pass revealed peak surface winds of 33 kt in the northwestern quadrant, and satellite imagery since then indicates a marked increase in the deep convection, albeit sheared to the northeast of the well-defined low-level center noted in the scatterometer data. Based on these wind data and a satellite intensity estimate of T2.5/35 kt from TAFB and UW-CIMSS ADT, the depression has been upgraded to Tropical Storm Gabrielle, the seventh named storm of the 2019 Atlantic hurricane season. The initial motion is 310/09 kt. The initial position was adjusted slightly to the southwest of the previous positions based on the aforementioned scatterometer data. This has resulted in the new forecast track being shifted a little to the left of the previous advisory track at all forecast times. For the next 5 days, Gabrielle is forecast to move generally northwestward toward a break in the Bermuda-Azores high pressure ridge located between 40W-50W longitude. The official forecast track lies close to a blend of the tightly packed consensus models TVCN, TVCX, and NOAA-HCCA. During the entire forecast period, Gabrielle is forecast to remain in a marginally conducive environment characterized by moderate southwesterly vertical wind shear of 15-20 kt, SSTs of 26-27 deg C, and dry mid-level air with humidity values less than 50 percent. As a result, only slight strengthening is forecast through 72 hours. The new NHC intensity forecast is similar to the previous advisory, and closely follows the HCCA consensus intensity model. FORECAST POSITIONS AND MAX WINDS INIT 04/0900Z 19.6N 33.6W 35 KT 40 MPH 12H 04/1800Z 20.3N 34.4W 40 KT 45 MPH 24H 05/0600Z 21.1N 35.3W 40 KT 45 MPH 36H 05/1800Z 22.1N 36.4W 45 KT 50 MPH 48H 06/0600Z 23.4N 37.7W 45 KT 50 MPH 72H 07/0600Z 27.5N 41.0W 50 KT 60 MPH 96H 08/0600Z 31.5N 44.5W 50 KT 60 MPH 120H 09/0600Z 35.5N 47.2W 50 KT 60 MPH $$ Forecaster Stewart

Tags: number discussion storm tropical

 
 

Hurricane Juliette Forecast Discussion Number 13

2019-09-04 10:47:04| National Hurricane Center (East Pacific)

Issued at 200 AM PDT Wed Sep 04 2019 000 WTPZ41 KNHC 040846 TCDEP1 Hurricane Juliette Discussion Number 13 NWS National Hurricane Center Miami FL EP112019 Issued by NWS Central Pacific Hurricane Center Honolulu HI 200 AM PDT Wed Sep 04 2019 The appearance of Juliette in satellite continues to show a weakening trend early this morning. Multiple warm spots are evident in infrared imagery, but there has not been a consistent well-defined eye during the past several hours. The latest subjective and objective T-numbers provided by the satellite fix agencies also continue to show gradual weakening. Based on this input, the initial intensity is lowered to 95 kt for this advisory. Note that a 0410z ASCAT pass was used to adjust the initial wind radii for this advisory. The apparent motion appears to be somewhat slower than the previous 12 hours. For this advisory, the initial motion estimate is west-northwestward, or 300/5 kt. Juliette is being steered by the circulation around a mid-tropospheric subtropical ridge extending over the northeastern Pacific from the southwestern United States. This feature is expected to steer Juliette west-northwestward during the next few days. Toward the end of the forecast period, a westward motion is forecast as Juliette weakens and loses most of its deep convection. The weakening system will then likely be steered by the low-level easterly flow. The latest track forecast is close to the previous advisory package, with some nudging toward the most recent NOAA HFIP HCCA, ECMWF ensemble mean, and the GFEX consensus model. Cooler oceanic sea surface temperatures, an intruding dry, stable, surrounding environment, and increasing southwesterly shear should cause steady weakening of the cyclone during the next 5 days. The latest intensity forecast is showing a slightly faster weakening trend compared with the previous advisory package. Note that much of the guidance suggests the weakening trend may be even faster than the official forecast. FORECAST POSITIONS AND MAX WINDS INIT 04/0900Z 19.1N 116.4W 95 KT 110 MPH 12H 04/1800Z 19.5N 117.5W 85 KT 100 MPH 24H 05/0600Z 20.3N 119.0W 80 KT 90 MPH 36H 05/1800Z 21.1N 120.7W 70 KT 80 MPH 48H 06/0600Z 22.0N 122.5W 60 KT 70 MPH 72H 07/0600Z 23.0N 126.7W 40 KT 45 MPH 96H 08/0600Z 23.0N 130.5W 35 KT 40 MPH 120H 09/0600Z 23.0N 134.5W 30 KT 35 MPH $$ Forecaster Houston

Tags: number discussion forecast hurricane

 

Tropical Storm Fernand Forecast Discussion Number 5

2019-09-04 10:32:37| National Hurricane Center (Atlantic)

Issued at 400 AM CDT Wed Sep 04 2019 000 WTNT42 KNHC 040832 TCDAT2 Tropical Storm Fernand Discussion Number 5 NWS National Hurricane Center Miami FL AL072019 400 AM CDT Wed Sep 04 2019 An ASCAT-C scatterometer pass around 0310 UTC indicated a few wind vectors of 38-40 kt in the northwestern quadrant of the circulation. Allowing for some undersampling by the instrument, the initial intensity is held at 45 kt. The overall convective pattern in radar and satellite imagery has changed little over the past 6 hours. Fernand's motion is slowly westward at 270/05 kt. Fernand is expected to be steered westward this morning by a broad deep-layer ridge that extends across the entire southern United States, followed by a west-northwestward motion tonight and Thursday. As a result, the cyclone is forecast to move inland over northeastern Mexico by this evening, and then dissipate quickly over the rugged terrain of the Sierra Madre Oriental mountains. The NHC forecast track is similar to the previous advisory track and essentially lies down the middle of track guidance envelope. Fernand has been experiencing moderate easterly to southeasterly vertical wind shear and ingesting dry air in the southeastern semicircle. These unfavorable conditions are forecast to continue until landfall occurs in about 12 hours, resulting in little if any additional strengthening. The primary threat from this system will be heavy rainfall that could produce flooding and mudslides, especially in the mountainous areas of Mexico. Radar estimates from the NOAA Doppler weather radar in Brownsville, Texas (KBRO), indicate that up to 10 inches of rainfall may have already occurred across portions of northeastern Mexico. FORECAST POSITIONS AND MAX WINDS INIT 04/0900Z 23.1N 96.8W 45 KT 50 MPH 12H 04/1800Z 23.5N 97.9W 40 KT 45 MPH...INLAND 24H 05/0600Z 24.0N 99.2W 25 KT 30 MPH...INLAND 36H 05/1800Z...DISSIPATED INLAND $$ Forecaster Stewart

Tags: number discussion storm tropical

 

Hurricane Dorian Forecast Discussion Number 43

2019-09-04 04:57:00| National Hurricane Center (Atlantic)

Issued at 1100 PM EDT Tue Sep 03 2019 000 WTNT45 KNHC 040256 TCDAT5 Hurricane Dorian Discussion Number 43 NWS National Hurricane Center Miami FL AL052019 1100 PM EDT Tue Sep 03 2019 Dorian's structure has changed significantly during the past day or so. Satellite and Doppler radar images show that the inner core has become rather broad with a large ragged eye of at least 30 n mi diameter. Data from the Air Force Hurricane Hunters indicate that the maximum winds and minimum pressure have held steady since this afternoon, and based on that information, the initial intensity is held at 95 kt, but this could be a little generous. The aircraft data and surface observations indicate that the wind field is expanding in size with tropical-storm-force and hurricane-force winds extending up to 150 n mi and 50 n mi from the center, respectively. NOAA data buoy 41010 just northeast of the center has been reporting sustained winds as high as 60 kt with gusts to 78 kt, and seas over 30 ft. Dorian is finally on the move again, and the latest initial motion estimate is 340 degrees at 5 kt. Dorian is being steered by the flow between a mid-level ridge to the east and broad troughing to its north. A northwest to north motion with some increase in forward speed is expected through Wednesday, taking the core of Dorian just offshore and parallel to the east coast of Florida during that time. Thereafter, a faster motion toward the northeast is predicted as a series of shortwave troughs move across the northeastern U.S. This should take the core of the hurricane very near, or possibly over, the coasts of South and North Carolina on Thursday and Friday. After it passes the Outer Banks, the hurricane is forecast to accelerate northeastward in the stronger mid-latitude flow toward the Canadian Maritimes this weekend. The NHC track forecast is largely unchanged and near the middle of the tightly packed guidance envelope. The hurricane is in a favorable environment of low wind shear, high moisture, and warm SSTs, and it is expected to stay in these conditions until it nears the Carolina coast. Therefore, Dorian is expected to remain about the same intensity during the next couple of days. After that time, an increase in shear from the mid-latitude trough and drier air should cause Dorian to slowly weaken. The GFS and ECMWF models both show Dorian becoming an extratropical system by 96 hours, and the official forecast follows those solutions. As this system gains latitude, the wind field is expected to expand even more. Therefore, even if Dorian does not make landfall, hurricane-force winds are expected to reach portions of the coast from central Florida to North Carolina. Key Messages: 1. Life-threatening storm surge and dangerous winds are expected along portions of the Florida east coast and the coasts of Georgia, South Carolina, and North Carolina, regardless of the exact track of Dorian's center. Water levels could rise well in advance of the arrival of strong winds. Residents in these areas should follow advice given by local emergency officials. 2. The risk of wind and rain impacts along portions of the Virginia coast and the southern Chesapeake Bay are increasing. Residents in these areas should continue to monitor the progress of Dorian. 3. The flash flood threat will increase overnight along the Florida east coast, then spread up the southeast and mid Atlantic coast beginning Wednesday. There is a moderate risk of flash flooding from coastal Georgia through the eastern portions of South and North Carolina Wednesday and Thursday. FORECAST POSITIONS AND MAX WINDS INIT 04/0300Z 28.4N 79.0W 95 KT 110 MPH 12H 04/1200Z 29.4N 79.6W 95 KT 110 MPH 24H 05/0000Z 30.7N 79.9W 95 KT 110 MPH 36H 05/1200Z 31.9N 79.5W 95 KT 110 MPH 48H 06/0000Z 33.3N 78.2W 90 KT 105 MPH 72H 07/0000Z 37.1N 72.1W 75 KT 85 MPH 96H 08/0000Z 43.3N 62.7W 70 KT 80 MPH...POST-TROP/EXTRATROP 120H 09/0000Z 51.5N 52.2W 60 KT 70 MPH...POST-TROP/EXTRATROP $$ Forecaster Cangialosi

Tags: number discussion forecast hurricane

 

Sites : [380] [381] [382] [383] [384] [385] [386] [387] [388] [389] [390] [391] [392] [393] [394] [395] [396] [397] [398] [399] next »