Home › discussion
 

Keywords :   


Tag: discussion

Tropical Depression EIGHT-E Forecast Discussion Number 2

2015-07-28 04:32:59| National Hurricane Center (East Pacific)

Issued at 800 PM PDT MON JUL 27 2015 000 WTPZ43 KNHC 280232 TCDEP3 TROPICAL DEPRESSION EIGHT-E DISCUSSION NUMBER 2 NWS NATIONAL HURRICANE CENTER MIAMI FL EP082015 800 PM PDT MON JUL 27 2015 The depression has become somewhat less organized since the last advisory. The center has become exposed to the northwest of an amorphous but persistent mass of deep convection. According to the UW-CIMSS shear analyses, the cyclone's appearance is a result of northwesterly shear of around 20 kt associated with an upper-level trough located to its northeast. Last-light visible satellite images also showed arc clouds on the fringes of the eastern half of the circulation, indicative of dry air entrainment. A satellite classification of T2.0 from both SAB at 0000 UTC is used to maintain the initial intensity at 30 kt. Any opportunity for the depression to strengthen is expected to be in the very short term. Water vapor imagery shows the cyclone moving into a region dominated by very dry mid- to upper-tropospheric air. The dry air, in combination with lower sea surface temperatures and greater atmospheric stability, should result in weakening after 24 to 36 hours. Global models show the system opening up into a trough in about 3 days in an increasingly unfavorable environment, around the time it crosses 140W. Like the previous forecast, this one shows little intensification, followed by weakening. However, dissipation is predicted much sooner (by 96 hours) based on the latest guidance. The initial motion estimate is 290/12. A low- to mid-level ridge over the subtropical eastern Pacific should steer the cyclone on a west-northwestward course during the next few days. The model solutions diverge to some degree after 12 to 24 hours, due to their handling of the strength of this feature. The GFS and its ensemble mean have a weaker ridge and are farthest north while the ECWMF, with a stronger ridge, is on the southern side of the guidance envelope. The new forecast track results in little overall change from the previous one and is nearly split between the ECMWF and GFS, near the multi-model consensus. FORECAST POSITIONS AND MAX WINDS INIT 28/0300Z 16.0N 127.0W 30 KT 35 MPH 12H 28/1200Z 16.4N 128.7W 30 KT 35 MPH 24H 29/0000Z 16.9N 131.0W 35 KT 40 MPH 36H 29/1200Z 17.2N 133.3W 35 KT 40 MPH 48H 30/0000Z 17.5N 135.8W 30 KT 35 MPH 72H 31/0000Z 18.0N 141.3W 25 KT 30 MPH 96H 01/0000Z...DISSIPATED $$ Forecaster Kimberlain

Tags: number discussion tropical depression

 

Tropical Depression EIGHT-E Forecast Discussion Number 1

2015-07-27 22:55:24| National Hurricane Center (East Pacific)

Issued at 200 PM PDT MON JUL 27 2015 000 WTPZ43 KNHC 272055 TCDEP3 TROPICAL DEPRESSION EIGHT-E DISCUSSION NUMBER 1 NWS NATIONAL HURRICANE CENTER MIAMI FL EP082015 200 PM PDT MON JUL 27 2015 The low pressure system located more than 1000 n mi west-southwest of the Baja California peninsula has finally acquired enough persistent deep convection near the center for it to be upgraded to a tropical depression. An 1831 UTC ASCAT-B overpass indicated a well-defined circulation center and inner-core wind field containing several 30-31 kt surface wind vectors at a distance of 35-40 nmi to the northeast and southeast of the center. Although the depression is a sheared tropical cyclone, a T2.0/30 kt Dvorak satellite classification from TAFB also justifies upgrading the low to a tropical depression at this time. The initial motion estimate is 290/14 kt, which is based primarily on microwave and ASCAT satellite fixes. The NHC model guidance is in good agreement on the tropical cyclone moving toward the west-northwest at 12-14 kt for the next 72 hours or so due to a strong deep-layer ridge locate to its north. After that, however, the guidance diverges significantly with the ECMWF model taking a very weak cyclone or trough west-southwestward, the GFS and HWRF models moving the system westward, while the GFS-ensemble mean and the remainder of the models keep the depression on a slower west-northwestward track. The NHC official forecast track basically lies down the middle of the guidance suite throughout the forecast period and is close to the consensus model TVCE. The cyclone is not expected to intensify much due to persistent moderate northwesterly vertical wind shear and the cyclone moving over marginal sea-surface temperatures after 72 hours. There will also likely be occasional intrusions of drier and more stable air, which lies just to the north of the forecast track, into the cyclone. However, the well-established southerly low-level inflow of unstable air should help to maintain enough convection to keep this system as a tropical cyclone throughout the forecast period. The NHC intensity forecast is similar to the ICON consensus model. FORECAST POSITIONS AND MAX WINDS INIT 27/2100Z 15.6N 126.1W 30 KT 35 MPH 12H 28/0600Z 16.1N 128.1W 30 KT 35 MPH 24H 28/1800Z 16.6N 130.4W 35 KT 40 MPH 36H 29/0600Z 17.0N 132.6W 35 KT 40 MPH 48H 29/1800Z 17.3N 134.6W 35 KT 40 MPH 72H 30/1800Z 17.9N 139.8W 35 KT 40 MPH 96H 31/1800Z 18.2N 145.9W 35 KT 40 MPH 120H 01/1800Z 18.4N 151.3W 30 KT 35 MPH $$ Forecaster Stewart

Tags: number discussion tropical depression

 
 

Post-Tropical Cyclone FELICIA Forecast Discussion Number 8

2015-07-25 04:32:12| Tropical Depression LIDIA

Issued at 800 PM PDT FRI JUL 24 2015

Tags: number discussion forecast cyclone

 

Tropical Depression FELICIA Forecast Discussion Number 6

2015-07-24 16:33:35| Tropical Depression LIDIA

Issued at 800 AM PDT FRI JUL 24 2015

Tags: number discussion tropical depression

 

Tropical Depression FELICIA Forecast Discussion Number 4

2015-07-24 04:33:59| Tropical Depression LIDIA

Issued at 800 PM PDT THU JUL 23 2015

Tags: number discussion tropical depression

 

Sites : [1000] [1001] [1002] [1003] [1004] [1005] [1006] [1007] [1008] [1009] [1010] [1011] [1012] [1013] [1014] [1015] [1016] [1017] [1018] [1019] next »