Home › discussion
 

Keywords :   


Tag: discussion

Tropical Storm Ignacio Forecast Discussion Number 5

2021-08-02 22:34:03| National Hurricane Center (East Pacific)

Issued at 300 PM MDT Mon Aug 02 2021 000 WTPZ45 KNHC 022033 TCDEP5 Tropical Storm Ignacio Discussion Number 5 NWS National Hurricane Center Miami FL EP102021 300 PM MDT Mon Aug 02 2021 Ignacio appears to have peaked in intensity, with moderate-to- strong northeasterly vertical wind shear having displaced most of the deep convection into the southwestern semicircle of the cyclone. The latest subjective satellite current intensity estimates from TAFB and SAB remain at T2.5/35 kt, and objective estimates from UW-CIMSS ADT and SATCON are 37 kt and 38 kt, respectively. Based on these data, the intensity has been held at 35 kt, which could be generous. The center of Ignacio passed 15-20 nmi northeast of Clarion Island, Mexico, where the pressure fell to 1006.5 mb around 1400 UTC and the highest winds measured were sustained 22 kt gusting to 33 kt according to a Mexican navy observing station on the island. A pronounced wind shift from the northeast to the southwest and west was also noted in the wind data. However, wind speeds have been steadily decreasing over the past several hours, an indication that the strongest winds are likely occurring in the northeastern quadrant. Unfortunately, all three ASCAT passes again missed the center and the strongest winds associated with Ignacio. The initial motion estimate is 300/08 kt. No significant changes were required to the previous track forecast. Ignacio is forecast to maintain a west-northwestward motion between a strong mid-/upper-level ridge to the north and Hurricane Hilda to the southwest throughout the short forecast period. The new advisory track forecast is similar the previous forecast track, and lies along the left side of the consensus track models envelope. Ignacio is expected to gradually weaken during the next 48 hours due to steadily increasing northeasterly vertical wind shear in excess of 25 kt by 24 hours and beyond. By 18-24 hours, Ignacio will be moving over sub-26C sea-surface temperatures, which will act to hasten the weakening process, with dissipation expected by 60 hours, if not sooner. The new NHC intensity forecast is similar to the previous advisory and a blend of the NOAA-HCCA and IVCN consensus intensity models. FORECAST POSITIONS AND MAX WINDS INIT 02/2100Z 18.8N 114.9W 35 KT 40 MPH 12H 03/0600Z 19.5N 116.0W 30 KT 35 MPH 24H 03/1800Z 20.4N 117.2W 25 KT 30 MPH 36H 04/0600Z 21.2N 118.1W 20 KT 25 MPH...POST-TROP/REMNT LOW 48H 04/1800Z 21.2N 118.9W 20 KT 25 MPH...POST-TROP/REMNT LOW 60H 05/0600Z...DISSIPATED $$ Forecaster Stewart

Tags: number discussion storm tropical

 

Hurricane Hilda Forecast Discussion Number 12

2021-08-02 16:34:24| National Hurricane Center (East Pacific)

Issued at 800 AM PDT Mon Aug 02 2021 000 WTPZ43 KNHC 021434 TCDEP3 Hurricane Hilda Discussion Number 12 NWS National Hurricane Center Miami FL EP082021 800 AM PDT Mon Aug 02 2021 The satellite presentation of Hilda hasn't changed much in the past several hours, with a round central dense overcast and perhaps a ragged eye trying to form. The intensity estimates range from 60-77 kt, and since the hurricane's presentation is about the same as the last advisory, the current wind speed will remain 70 kt. This is one of those times that in situ reconnaissance data would be helpful since there has been lots of spread in the intensity estimates for quite some time, and Hilda is at an intensity where it is hard to get more precise measurements. The hurricane has finally turned northwestward and should continue in that general direction for the next couple of days on the southwestern side of the subtropical ridge, with some influence from Ignacio to the northeast. Model guidance is in decent agreement that Hilda will turn back to the west-northwest by midweek and then west under the restrengthened subtropical ridge. While there are still some outlier solutions, the latest consensus guidance is near the previous NHC forecast, so only small changes were made on this advisory. Hilda is maintaining good inner-core structure on the latest microwave data despite northeasterly shear (perhaps because of a fairly moist mid-level environment around the hurricane), so little intensity change is forecast for today. Thereafter, the system should move over cooler waters into a drier environment, which should cause gradual weakening for the next several days. Very little change was made to the NHC intensity forecast, and it is close to the HCCA and IVCN consensus aids throughout. Remnant-low status is expected by 96 h, if not sooner. FORECAST POSITIONS AND MAX WINDS INIT 02/1500Z 15.4N 122.6W 70 KT 80 MPH 12H 03/0000Z 16.0N 123.1W 70 KT 80 MPH 24H 03/1200Z 16.9N 123.8W 60 KT 70 MPH 36H 04/0000Z 17.9N 124.7W 50 KT 60 MPH 48H 04/1200Z 18.9N 126.0W 40 KT 45 MPH 60H 05/0000Z 19.7N 127.5W 35 KT 40 MPH 72H 05/1200Z 20.4N 129.3W 30 KT 35 MPH 96H 06/1200Z 21.5N 133.9W 25 KT 30 MPH...POST-TROP/REMNT LOW 120H 07/1200Z 21.5N 138.5W 20 KT 25 MPH...POST-TROP/REMNT LOW $$ Forecaster Blake

Tags: number discussion forecast hurricane

 
 

Tropical Storm Ignacio Forecast Discussion Number 4

2021-08-02 16:33:23| National Hurricane Center (East Pacific)

Issued at 900 AM MDT Mon Aug 02 2021 000 WTPZ45 KNHC 021433 TCDEP5 Tropical Storm Ignacio Discussion Number 4 NWS National Hurricane Center Miami FL EP102021 900 AM MDT Mon Aug 02 2021 A large burst of deep convection has developed near the center and over most of the southwestern semicircle of the cyclone. Recent subjective satellite intensity estimates are a consensus T2.5/35 kt from TAFB and SAB, and objective estimates from UW-CIMSS ADT and SATCON are 37 kt and 39 kt, respectively. Based on these data, the intensity has been increased to 35 kt, making the system the ninth tropical storm of the 2021 eastern North Pacific hurricane season. Tropical Storm Ignacio has continued to move west-northwestward, and the initial motion estimate is 295/08 kt. Both the track forecast and synoptic reasoning remain unchanged for this advisory. Ignacio is expected to maintain a west-northwestward motion, wedged between a strong mid-/upper-level ridge to the north and Hurricane Hilda to the southwest throughout the 48-hour forecast period. The new track forecast is essentially just an update of the previous advisory track, and lies down the middle of the tightly packed consensus track models. Ignacio is likely near its peak intensity given that northeasterly vertical wind shear of 18-20 kt is expected to keep the strongest convection displaced away from the strongest surface winds that are likely occurring in the northeastern semicircle. By 24 hours or so, Ignacio will be moving over sub-26C sea-surface temperatures and into even stronger wind shear, which should induce steady weakening, with dissipation expected by 60 hours. The new NHC intensity forecast is similar to the previous advisory, and closely follows a blend of the NOAA-HCCA and IVCN consensus intensity models. FORECAST POSITIONS AND MAX WINDS INIT 02/1500Z 18.3N 114.0W 35 KT 40 MPH 12H 03/0000Z 19.0N 115.3W 35 KT 40 MPH 24H 03/1200Z 19.8N 116.7W 30 KT 35 MPH 36H 04/0000Z 20.3N 117.6W 25 KT 30 MPH...POST-TROP/REMNT LOW 48H 04/1200Z 20.7N 118.5W 20 KT 25 MPH...POST-TROP/REMNT LOW 60H 05/0000Z...DISSIPATED $$ Forecaster Stewart

Tags: number discussion storm tropical

 

Tropical Depression Ten-E Forecast Discussion Number 3

2021-08-02 10:37:33| National Hurricane Center (East Pacific)

Issued at 300 AM MDT Mon Aug 02 2021 439 WTPZ45 KNHC 020837 TCDEP5 Tropical Depression Ten-E Discussion Number 3 NWS National Hurricane Center Miami FL EP102021 300 AM MDT Mon Aug 02 2021 The depression has not become any better organized overnight. In fact, the earlier cluster of deep convection that was located to the west of the center has weakened with the center becoming farther exposed to the northeast of a new burst of convection that has recently developed. Unfortunately the tropical cyclone was located within the gap of the polar-orbiting ASCAT instrument overnight so there were no scatterometer data to help ascertain the depression's intensity. Subjective Dvorak estimates from SAB and TAFB ranged from 30 to 35 kt, and since there has been no overall change in organization, the intensity is held at 30 kt for this advisory. The depression has a short window of opportunity today in which to become a tropical storm, however increasing shear and cool waters along the forecast track should end that possibility by early tonight. Weakening is expected to begin shortly thereafter as the system moves into aforementioned hostile environmental conditions, and the cyclone is predicted to become a remnant low by late Tuesday, and dissipate on Wednesday. The NHC intensity forecast is close to the intensity consensus and follows the global model guidance in calling for dissipation in 48-60 h. The depression is moving west-northwestward or 295/9 kt. The track forecast reasoning remains unchanged as the cyclone should move west-northwestward along the southwestern portion of a mid-level ridge. As the system weakens, it is likely to slow down and turn westward within the low-level flow around Hilda located to its southwest. The NHC track prediction remains near the middle of the guidance envelope, and little modification to the previous advisory was needed. FORECAST POSITIONS AND MAX WINDS INIT 02/0900Z 18.0N 113.4W 30 KT 35 MPH 12H 02/1800Z 18.7N 114.9W 35 KT 40 MPH 24H 03/0600Z 19.6N 116.5W 30 KT 35 MPH 36H 03/1800Z 20.3N 117.7W 25 KT 30 MPH...POST-TROP/REMNT LOW 48H 04/0600Z 20.5N 118.3W 20 KT 25 MPH...POST-TROP/REMNT LOW 60H 04/1800Z...DISSIPATED $$ Forecaster Brown

Tags: number discussion tropical depression

 

Hurricane Hilda Forecast Discussion Number 11

2021-08-02 10:36:49| National Hurricane Center (East Pacific)

Issued at 200 AM PDT Mon Aug 02 2021 000 WTPZ43 KNHC 020836 TCDEP3 Hurricane Hilda Discussion Number 11 NWS National Hurricane Center Miami FL EP082021 200 AM PDT Mon Aug 02 2021 SSMIS microwave data received just after the previous advisory indicate that Hilda's structure may have improved slightly, with a closed mid-level eye noted in the 85-GHz channel. However, the microwave data also showed that the low- and mid-level centers remain offset from each other by about 15 n mi due to continued moderate easterly shear. The initial intensity remains 70 kt, which is a blend of the latest final-T Dvorak numbers from TAFB and SAB. Hilda has begun to turn to the right and slow down, and the initial motion is west-northwestward (295 degrees) at 7 kt. Although the subtropical ridge remains positioned to the north of Hilda, the hurricane's close proximity to Tropical Depression Ten-E and the remnants of Tropical Depression Nine-E is expected to cause some binary interaction over the next couple of days, with Hilda likely to slow down further and turn toward the northwest later today and continue on that heading through Wednesday. In fact, the newest track guidance has trended to the northeast during the first 48 hours, and the updated NHC forecast has therefore been shifted a bit to the right during that period. However, it should be noted that the track adjustment is conservative, and does not show a turn quite as sharp as that shown by the TVCE and HCCA consensus aids. Low-level ridging should play a more prominent role in about 3 days, causing Hilda to turn back toward the west-northwest and then west by the end of the forecast period. No significant track changes were required during the day 3-5 time period. Moderate east-northeasterly shear is expected to continue for the next 36 hours or so, with Hilda also heading toward cooler waters during that time. Therefore, gradual weakening is expected to commence later today, and the NHC intensity forecast is close to the HCCA and ICON consensus aids for the next day or so. Sub-26 degree Celsius waters are likely to cause quicker weakening from 36 hours onward, and the NHC intensity forecast has been nudged downward during that period. This new forecast is lower than the statistical-dynamical models but not nearly as low as the latest HCCA solution. Hilda is now forecast to weaken to a tropical depression by day 3 and degenerate into a remnant low by day 4, although the HCCA scenario suggests that these transitions could occur as much as a day earlier. FORECAST POSITIONS AND MAX WINDS INIT 02/0900Z 15.3N 122.1W 70 KT 80 MPH 12H 02/1800Z 15.8N 122.7W 70 KT 80 MPH 24H 03/0600Z 16.7N 123.5W 65 KT 75 MPH 36H 03/1800Z 17.8N 124.3W 55 KT 65 MPH 48H 04/0600Z 18.9N 125.5W 45 KT 50 MPH 60H 04/1800Z 19.8N 127.0W 35 KT 40 MPH 72H 05/0600Z 20.5N 128.8W 30 KT 35 MPH 96H 06/0600Z 21.2N 132.6W 25 KT 30 MPH...POST-TROP/REMNT LOW 120H 07/0600Z 21.5N 136.5W 20 KT 25 MPH...POST-TROP/REMNT LOW $$ Forecaster Berg

Tags: number discussion forecast hurricane

 

Sites : [78] [79] [80] [81] [82] [83] [84] [85] [86] [87] [88] [89] [90] [91] [92] [93] [94] [95] [96] [97] next »