Home discussion
 

Keywords :   


Tag: discussion

Tropical Storm Josephine Forecast Discussion Number 11

2020-08-14 10:36:53| National Hurricane Center (Atlantic)

Issued at 500 AM AST Fri Aug 14 2020 000 WTNT41 KNHC 140836 TCDAT1 Tropical Storm Josephine Discussion Number 11 NWS National Hurricane Center Miami FL AL112020 500 AM AST Fri Aug 14 2020 As has been the case for the last couple of days, the center of the tropical storm is displaced to the south of the main area of deep convection. Some new convective cells have been forming nearer to the estimated center, but the overall cloud pattern is quite ragged-looking at this time. ASCAT data from a few hours ago indicate that the intensity is near 35 kt, which is consistent with the latest Dvorak estimates from TAFB and SAB. NOAA data buoy 41040 confirmed that the system still has a closed circulation since it reported light westerly winds while the center of Josephine passed to its north. An Air Force Reserve Unit Hurricane Hunter aircraft is scheduled to investigate the storm later today. Josephine is beginning to move into an environment of increasing vertical shear associated with a large upper-tropospheric trough over the western Atlantic. Therefore, the window of opportunity for strengthening is closing soon. The official intensity forecast allows for some intensification during the next 24 hours before the upper-level winds become prohibitively strong. However, the NHC forecast is now above most of the model intensity guidance through 72 hours. The storm continues its west-northwestward motion and is moving at about 300/15 kt. Josephine should continue this general motion as it approaches a weakness in the subtropical ridge in 48 hours or so. Then, the cyclone should turn northward and move through the weakness in 3-4 days. Late in the forecast period, Josephine or its remnants are expected to turn north-northeastward while it approaches the higher-latitude westerlies. The official track forecast is essentially the same as the previous one, and also lies close to the latest corrected multi-model consensus. Josephine should pass far enough to the northeast of the Leeward Islands over the weekend to prevent major impacts. However, interests in the area should continue to monitor its progress until the storm has passed north of that area. FORECAST POSITIONS AND MAX WINDS INIT 14/0900Z 15.3N 53.3W 35 KT 40 MPH 12H 14/1800Z 16.5N 55.3W 40 KT 45 MPH 24H 15/0600Z 18.0N 58.1W 45 KT 50 MPH 36H 15/1800Z 19.1N 60.6W 45 KT 50 MPH 48H 16/0600Z 20.3N 62.9W 40 KT 45 MPH 60H 16/1800Z 21.6N 65.1W 35 KT 40 MPH 72H 17/0600Z 23.1N 66.7W 35 KT 40 MPH 96H 18/0600Z 26.0N 67.8W 30 KT 35 MPH 120H 19/0600Z 30.0N 66.5W 25 KT 30 MPH...POST-TROP/REMNT LOW $$ Forecaster Pasch

Tags: number discussion storm tropical

 

Tropical Depression Ten-E Forecast Discussion Number 5

2020-08-14 10:35:23| National Hurricane Center (East Pacific)

Issued at 200 AM PDT Fri Aug 14 2020 120 WTPZ45 KNHC 140835 TCDEP5 Tropical Depression Ten-E Discussion Number 5 NWS National Hurricane Center Miami FL EP102020 200 AM PDT Fri Aug 14 2020 The circulation of the depression was devoid of deep convection for several hours tonight and just recently new convection has begun to develop near the center. Although the Dvorak data T-numbers continue to decrease, a recent ASCAT overpass revealed there were several wind vectors supporting keeping the initial intensity at 30 kt. The ASCAT ambiguities from the overpass suggest that the low may be starting to become less well-defined, and if deep convection cannot persist for an appreciable amount of time, the system may open into a trough embedded in the Intertropical Convergence Zone. The current environment consisting of moderate northeasterly shear, modest moisture, and some subsidence is not expected to change all that much over the next few days. None of the intensity guidance except for the SHIPS makes the system a tropical storm. However, the simulated satellite imagery from various models do suggest that intermittent convection should continue to develop near the center in the near-term, which could provide enough vortex spin-up to keep the system a depression for a little while. The official intensity forecast is unchanged from the previous one, but it should be reiterated that the system could dissipate or degenerate to a convection-free remnant low at any time. The depression is now moving just south of west at 4 kt and is being steered by a low-level ridge to its northwest. This ridge is forecast to remain in place for the next couple of days. Over the weekend, the ridge is forecast to weaken, and with the loss of steering flow, the depression may begin to drift generally northwestward. The latest NHC forecast is little changed from the previous one and is also near the TVCE/TVCX consensus aids. FORECAST POSITIONS AND MAX WINDS INIT 14/0900Z 14.1N 131.5W 30 KT 35 MPH 12H 14/1800Z 13.9N 132.0W 30 KT 35 MPH 24H 15/0600Z 13.7N 132.6W 30 KT 35 MPH 36H 15/1800Z 13.6N 133.0W 30 KT 35 MPH 48H 16/0600Z 13.7N 133.3W 30 KT 35 MPH 60H 16/1800Z 14.1N 133.7W 30 KT 35 MPH 72H 17/0600Z 14.6N 134.0W 30 KT 35 MPH 96H 18/0600Z 15.0N 134.7W 30 KT 35 MPH 120H 19/0600Z 15.1N 135.4W 30 KT 35 MPH...POST-TROP/REMNT LOW $$ Forecaster Latto

Tags: number discussion tropical depression

 
 

Tropical Storm Josephine Forecast Discussion Number 10

2020-08-14 04:35:24| National Hurricane Center (Atlantic)

Issued at 1100 PM AST Thu Aug 13 2020 000 WTNT41 KNHC 140235 TCDAT1 Tropical Storm Josephine Discussion Number 10 NWS National Hurricane Center Miami FL AL112020 1100 PM AST Thu Aug 13 2020 Enhanced infrared GOES 16 imagery and a recent ASCAT-A overpass indicated that the center of circulation is still located to the south of a rather shapeless deep convective mass. Recent images show a small burst developing just to the west of the center, but the associated cloud tops are already warming. Based on the overall cloud pattern, light southerly shear and a dry, relatively stable surrounding environment continue to hamper significant development. There were no changes to the satellite intensity estimates from TAFB and SAB, and the initial intensity is once again held at a possibly generous 40 kt. Josephine's relatively small window of opportunity for further strengthening is within the next 18 to 24 hours. The forecast still shows a peak intensity of 50 kt at the time and is above all of the skilled guidance. After which, strong southwesterly shear produced by a northeast to southwest oriented deep-layer mid-Atlantic trough is expected to induce gradual weakening. This inhibiting upper wind pattern is forecast to affect the cyclone through day 5. The NHC forecast through 60 hours is based on the better performing IVCN consensus which consists of the Decay SHIPS, LGEM and the hurricane models. Beyond mid-period, the forecast is basically a blend of the IVCN and the global models which now shows Josephine degenerating into a remnant low at day 5. The initial motion is estimated to be west-northwestward, or 300/15 kt within the southwestern periphery of a subtropical high situated to the northeast of Josephine. Weakening of the western portion of the ridge should cause Josephine to turn northwestward in 3 days, followed by a turn generally northward at day 4 in response to a major shortwave trough approaching the east coast of the U.S. and the western Atlantic. The official forecast is a little faster than the previous one through 5 days and is once again close to the HFIP Corrected Consensus model. Josephine should pass far enough to the northeast of the Leeward Islands over the weekend to prevent major impacts. However, interests in the area should continue to monitor its progress until the storm has passed north of that area. FORECAST POSITIONS AND MAX WINDS INIT 14/0300Z 14.8N 52.2W 40 KT 45 MPH 12H 14/1200Z 15.8N 54.0W 45 KT 50 MPH 24H 15/0000Z 17.3N 56.7W 50 KT 60 MPH 36H 15/1200Z 18.8N 59.5W 45 KT 50 MPH 48H 16/0000Z 20.0N 62.1W 40 KT 45 MPH 60H 16/1200Z 21.3N 64.4W 40 KT 45 MPH 72H 17/0000Z 22.8N 66.2W 35 KT 40 MPH 96H 18/0000Z 26.0N 67.7W 30 KT 35 MPH 120H 19/0000Z 29.5N 66.9W 25 KT 30 MPH...POST-TROP/REMNT LOW $$ Forecaster Roberts

Tags: number discussion storm tropical

 

Tropical Depression Ten-E Forecast Discussion Number 4

2020-08-14 04:34:49| National Hurricane Center (East Pacific)

Issued at 800 PM PDT Thu Aug 13 2020 274 WTPZ45 KNHC 140234 TCDEP5 Tropical Depression Ten-E Discussion Number 4 NWS National Hurricane Center Miami FL EP102020 800 PM PDT Thu Aug 13 2020 Since the issuance of the previous NHC advisory, deep convection associated with the depression has waned and become separated from the low-level center due to modest northeasterly shear. This has resulted in the low-level center becoming exposed. With the recent loss of organization, Dvorak data T-numbers have decreased and a blend of the various estimates yields an initial wind speed of 30 kt. The dynamical model guidance suggests that moderate to strong shear will continue to plague the cyclone during the next 2 to 3 days, and the intensity guidance is not quite as bullish as before. As a result, the new NHC intensity forecast calls for little change in strength during that time. It still remains possible, however, that new bursts of convection could allow the depression to cross the tropical storm threshold. After 72 hours, the shear is forecast to decrease but less favorable thermodynamic conditions are expected to prevent strengthening. The new forecast calls for the depression to degenerate into a remnant low by the end of the forecast period, but this could occur much sooner if the shear persists and the depression is unable to generate persistent convection. The depression is moving westward or 270/4 kt. A low- to mid-level ridge to the north of the system is expected to steer the cyclone slowly west-southwestward during the next 24 to 36 hours. After that time, the depression is forecast to meander generally northwestward. The latest runs of the dynamical models have trended toward a slower motion of the cyclone between days 2-5, and the updated NHC track forecast has been shifted eastward to account for this model trend. FORECAST POSITIONS AND MAX WINDS INIT 14/0300Z 14.2N 131.0W 30 KT 35 MPH 12H 14/1200Z 14.1N 131.8W 30 KT 35 MPH 24H 15/0000Z 13.9N 132.5W 30 KT 35 MPH 36H 15/1200Z 13.7N 133.1W 30 KT 35 MPH 48H 16/0000Z 13.7N 133.6W 30 KT 35 MPH 60H 16/1200Z 13.9N 133.9W 30 KT 35 MPH 72H 17/0000Z 14.4N 134.0W 30 KT 35 MPH 96H 18/0000Z 14.8N 134.4W 30 KT 35 MPH 120H 19/0000Z 14.9N 134.9W 30 KT 35 MPH...POST-TROP/REMNT LOW $$ Forecaster Brown

Tags: number discussion tropical depression

 

Tropical Storm Josephine Forecast Discussion Number 9

2020-08-13 22:37:16| National Hurricane Center (Atlantic)

Issued at 500 PM AST Thu Aug 13 2020 000 WTNT41 KNHC 132037 TCDAT1 Tropical Storm Josephine Discussion Number 9 NWS National Hurricane Center Miami FL AL112020 500 PM AST Thu Aug 13 2020 There has been little change in the organization of Josephine since the last advisory. The low-level center is located near the southern edge of the main convective mass, and there is some weak outer banding in the northern semicircle. The initial intensity is held at 40 kt in best agreement with the CIMSS satellite consensus. Some arc clouds west of the main convective mass suggest that dry air is entraining into the system. However, where this dry air is coming from is not readily apparent in satellite imagery or model analyses. The initial motion is now west-northwestward or 295/14 kt. Josephine should continue this motion for the next 3-4 days as it moves toward a weakness in the western portion of the Atlantic subtropical ridge. The global models forecast the western end of the ridge to weaken even more by the end of the forecast period, which should cause the cyclone, or what is left of it by that time, to turn northwestward. The track guidance remains tightly clustered, and the new forecast track lies a little to the right of the previous track trough 48 h and close to the previous track thereafter. On the forecast track, Josephine should pass far enough to the northeast of the Leeward Islands to prevent major impacts. However, interests in the area should continue to monitor its progress until the storm has gone by. Josephine has about 36 h to strengthen before it encounters significant southwesterly shear. The new intensity forecast is unchanged in showing the storm strengthening to a peak intensity of 50 kt in 24-36 h. After that, some minor tweaks were made to the intensity during the expected shear-induced weakening. The new forecast intensity follows the overall trend of the intensity guidance. FORECAST POSITIONS AND MAX WINDS INIT 13/2100Z 14.5N 50.6W 40 KT 45 MPH 12H 14/0600Z 15.5N 52.6W 45 KT 50 MPH 24H 14/1800Z 16.9N 55.2W 50 KT 60 MPH 36H 15/0600Z 18.3N 57.9W 50 KT 60 MPH 48H 15/1800Z 19.6N 60.5W 45 KT 50 MPH 60H 16/0600Z 20.9N 62.9W 45 KT 50 MPH 72H 16/1800Z 22.0N 64.8W 40 KT 45 MPH 96H 17/1800Z 25.0N 67.5W 30 KT 35 MPH 120H 18/1800Z 28.0N 68.0W 25 KT 30 MPH $$ Forecaster Beven

Tags: number discussion storm tropical

 

Sites : [246] [247] [248] [249] [250] [251] [252] [253] [254] [255] [256] [257] [258] [259] [260] [261] [262] [263] [264] [265] next »