Home › discussion
 

Keywords :   


Tag: discussion

Hurricane DARBY Forecast Discussion Number 13

2016-07-14 22:44:05| National Hurricane Center (East Pacific)

Issued at 200 PM PDT THU JUL 14 2016 000 WTPZ45 KNHC 142043 TCDEP5 HURRICANE DARBY DISCUSSION NUMBER 13 NWS NATIONAL HURRICANE CENTER MIAMI FL EP052016 200 PM PDT THU JUL 14 2016 Darby is a little better organized this afternoon. Visible satellite imagery shows a well-defined convective band wrapping almost 1.5 times around the center, which has resulted in the development of a banding-type eye. Subjective and objective Dvorak estimates from the various agencies have remained steady or increased slightly since this morning; therefore the initial intensity is raised to 75 kt. Darby may still have to contend with some northeasterly shear for another 12-24 hours, but the shear then decreases after that time. On the other hand, oceanic heat content values ahead of the hurricane fall off precipitously in about 12 hours. Considering these competing factors, some gradual strengthening is expected during the next day or so, followed by slow weakening until the end of the forecast period due to cooler SSTs. The updated NHC intensity forecast is near the SHIPS and Florida State Superensemble, which are at the top end of the intensity guidance. Darby continues moving westward, or 280/12 kt. Strong mid-level ridging to the north of the hurricane is expected to persist for much of the forecast period, keeping Darby on a westward or perhaps west-northwestward path through day 5. The track guidance remains tightly clustered, as it has been for the past couple of days, although the overall guidance envelope shifted northward on this cycle, especially through day 3. Therefore, the official NHC track forecast has been adjusted northward, but it is near the southern edge of the guidance suite close to the GFS, GFS ensemble mean, and UKMET. FORECAST POSITIONS AND MAX WINDS INIT 14/2100Z 15.9N 118.1W 75 KT 85 MPH 12H 15/0600Z 16.3N 119.8W 80 KT 90 MPH 24H 15/1800Z 16.8N 121.8W 85 KT 100 MPH 36H 16/0600Z 17.2N 123.9W 85 KT 100 MPH 48H 16/1800Z 17.5N 125.7W 80 KT 90 MPH 72H 17/1800Z 17.8N 129.5W 70 KT 80 MPH 96H 18/1800Z 18.2N 134.0W 60 KT 70 MPH 120H 19/1800Z 18.5N 138.5W 50 KT 60 MPH $$ Forecaster Berg

Tags: number discussion forecast hurricane

 

Tropical Storm CELIA Forecast Discussion Number 33

2016-07-14 22:42:26| National Hurricane Center (East Pacific)

Issued at 200 PM PDT THU JUL 14 2016 000 WTPZ44 KNHC 142042 TCDEP4 TROPICAL STORM CELIA DISCUSSION NUMBER 33 NWS NATIONAL HURRICANE CENTER MIAMI FL EP042016 200 PM PDT THU JUL 14 2016 Celia continues to produce convective bands over the northern portion of the circulation, however the clouds tops have gradually warmed today. Despite decreasing Dvorak T-numbers, a recent ASCAT pass revealed a large area of 40 to 45 kt winds over the northern and northwestern portion of the circulation. Therefore, the initial wind speed remains 45 kt for this advisory. The tropical cyclone should weaken during the next 12 to 24 hours while it moves over SSTs of around 24C and into an area of moderate west-northwesterly shear. Celia is forecast to become post-tropical in 12 to 24 hours, and weaken to a remnant low within a couple of days. The cyclone will be moving over slightly warmer waters in 2 to 3 days, but strong westerly shear and drier mid-level air should prevent regeneration. A tight pressure gradient between the remnant low and a strong high pressure area to the north will likely help maintain winds of around 30 kt with the system for several days. Celia has been moving west-northwestward or 295/12 kt. The cyclone is forecast to turn westward on Friday as it becomes a shallow system and is steered by the low-level easterly flow. The track guidance is in good agreement on this scenario and the NHC forecast is near an average of the latest GFS and ECMWF models. FORECAST POSITIONS AND MAX WINDS INIT 14/2100Z 21.4N 138.0W 45 KT 50 MPH 12H 15/0600Z 21.8N 139.7W 40 KT 45 MPH 24H 15/1800Z 22.1N 142.2W 35 KT 40 MPH...POST-TROPICAL 36H 16/0600Z 22.3N 144.7W 30 KT 35 MPH...POST-TROP/REMNT LOW 48H 16/1800Z 22.8N 147.1W 30 KT 35 MPH...POST-TROP/REMNT LOW 72H 17/1800Z 23.5N 151.3W 30 KT 35 MPH...POST-TROP/REMNT LOW 96H 18/1800Z 24.2N 156.0W 30 KT 35 MPH...POST-TROP/REMNT LOW 120H 19/1800Z 25.2N 161.5W 25 KT 30 MPH...POST-TROP/REMNT LOW $$ Forecaster Brown

Tags: number discussion storm tropical

 
 

Tropical Storm CELIA Forecast Discussion Number 32

2016-07-14 16:46:24| National Hurricane Center (East Pacific)

Issued at 800 AM PDT THU JUL 14 2016 000 WTPZ44 KNHC 141446 TCDEP4 TROPICAL STORM CELIA DISCUSSION NUMBER 32 NWS NATIONAL HURRICANE CENTER MIAMI FL EP042016 800 AM PDT THU JUL 14 2016 Celia has continued to maintain a small area of deep convection this morning, however recent microwave imagery shows that the area of cold cloud tops has become separated from the low-level center due to some southwesterly shear. Dvorak current intensity numbers of T3.0 from both TAFB and SAB and the earlier ASCAT data support keeping an initial wind speed of 45 kt. The remaining convection should gradually decrease in coverage while Celia moves over SSTs around 24C during the next day or so. This should result in weakening, and Celia is forecast to become a post-tropical cyclone in 24 to 36 hours. After that time, the cyclone will be moving over slightly warmer SSTs, but moderate to strong westerly shear should prevent regeneration. A tight pressure gradient between the post-tropical cyclone and a strong high pressure area to the north will likely help maintain winds of around 30 kt with the system for several days. Recent microwave fixes indicate that Celia is moving west- northwestward, or 295/10 kt. The cyclone should continue moving west-northwestward today, but is forecast to turn westward on Friday as it becomes a shallow system and is steered by the low-level easterly flow. The NHC forecast track is close to the GFS, GFS ensemble mean, and the multi-model consensus, which are all in fairly close agreement. FORECAST POSITIONS AND MAX WINDS INIT 14/1500Z 20.8N 136.7W 45 KT 50 MPH 12H 15/0000Z 21.4N 138.4W 35 KT 40 MPH 24H 15/1200Z 21.7N 140.7W 30 KT 35 MPH 36H 16/0000Z 22.0N 143.2W 30 KT 35 MPH...POST-TROP/REMNT LOW 48H 16/1200Z 22.3N 145.7W 30 KT 35 MPH...POST-TROP/REMNT LOW 72H 17/1200Z 23.0N 149.8W 30 KT 35 MPH...POST-TROP/REMNT LOW 96H 18/1200Z 23.7N 154.5W 30 KT 35 MPH...POST-TROP/REMNT LOW 120H 19/1200Z 24.5N 160.0W 25 KT 30 MPH...POST-TROP/REMNT LOW $$ Forecaster Brown

Tags: number discussion storm tropical

 

Hurricane DARBY Forecast Discussion Number 12

2016-07-14 16:38:22| National Hurricane Center (East Pacific)

Issued at 800 AM PDT THU JUL 14 2016 000 WTPZ45 KNHC 141438 TCDEP5 HURRICANE DARBY DISCUSSION NUMBER 12 NWS NATIONAL HURRICANE CENTER MIAMI FL EP052016 800 AM PDT THU JUL 14 2016 Darby still appears to be feeling the effects of 10-15 kt of northeasterly shear. Recent microwave images continue to show a mid-level eye, but the deep convection has an asymmetric structure, primarily focused to the south and southwest of the center. Subjective and objective Dvorak estimates have not changed during the past six hours, and the initial intensity is therefore held at 70 kt. Although Darby is moving over a relative cool spot in the ocean, SSTs are still plenty warm to support strengthening for the next 36 hours. A limiting factor may be continued vertical shear, which does not seem to have decreased as the models had been indicating. The SHIPS guidance now shows the shear staying up between 10-15 kt during the next 24 hours, so only a little more strengthening is shown in the official forecast. The new NHC forecast shows a slightly lower peak intensity, and it should be noted that this forecast is still near the high end of the guidance. Much colder SSTs, on the order of 24-25 degrees Celsius, should contribute to weakening beyond 48 hours. The initial motion remains westward, or 280/11 kt. A well- established ridge to the north of Darby should continue steering the cyclone westward during the next five days. With the exception of the GFDL and HWRF models, which are located along the northern edge of the guidance envelope, the track models are tightly clustered and are showing more agreement than yesterday. The NHC forecast is south of the TVCE model consensus, and is very close to the previous official forecast and an average of the GFS and ECMWF models. FORECAST POSITIONS AND MAX WINDS INIT 14/1500Z 15.9N 116.9W 70 KT 80 MPH 12H 15/0000Z 16.3N 118.7W 75 KT 85 MPH 24H 15/1200Z 16.7N 121.1W 80 KT 90 MPH 36H 16/0000Z 17.0N 123.2W 80 KT 90 MPH 48H 16/1200Z 17.2N 125.2W 80 KT 90 MPH 72H 17/1200Z 17.4N 128.7W 65 KT 75 MPH 96H 18/1200Z 17.8N 132.5W 55 KT 65 MPH 120H 19/1200Z 18.5N 137.0W 45 KT 50 MPH $$ Forecaster Berg

Tags: number discussion forecast hurricane

 

Tropical Storm CELIA Forecast Discussion Number 31

2016-07-14 11:01:27| National Hurricane Center (East Pacific)

Issued at 200 AM PDT THU JUL 14 2016 000 WTPZ44 KNHC 140901 TCDEP4 TROPICAL STORM CELIA DISCUSSION NUMBER 31 NWS NATIONAL HURRICANE CENTER MIAMI FL EP042016 200 AM PDT THU JUL 14 2016 Although conventional satellite imagery indicates some decrease in overall deep convection coverage this morning, a 0558 UTC ASCAT overpass revealed numerous 45 kt winds over the northern half of the system. West-southwesterly shear appears to be undercutting the upper easterly diffluent flow aloft, subsequently, creating a structural tilt and displacing the circulation center to the south of the convective mass. The initial intensity is held at 45 kt based on the aforementioned scatterometer pass. Celia is traversing gradually decreasing sea surface temperatures, and the large-scale models all indicate that the cyclone will encounter moderate to strong westerly shear by the 72 hour forecast period. Therefore, the cyclone should commence a weakening trend today, and become a depression by tonight. The official forecast is based primarily on a blend of the LGEM and decay SHIPS and reflects a degeneration of the cyclone into a remnant low in 36 hours. The initial motion is estimated to be west-northwestward, or 295/11 kt, around the southwestern periphery of a subtropical ridge anchored to the north of the cyclone. Guidance shows that Celia should turn westward by the 36 hour period as the cyclone decays into a shallow system and is steered by the low-level trades. The NHC forecast is weighed heavily on the multi-model consensus, and is adjusted slightly to the south of the previous forecast beyond day 3. FORECAST POSITIONS AND MAX WINDS INIT 14/0900Z 20.3N 135.8W 45 KT 50 MPH 12H 14/1800Z 21.0N 137.4W 35 KT 40 MPH 24H 15/0600Z 21.6N 139.7W 30 KT 35 MPH 36H 15/1800Z 21.9N 142.0W 30 KT 35 MPH...POST-TROP/REMNT LOW 48H 16/0600Z 22.2N 144.6W 30 KT 35 MPH...POST-TROP/REMNT LOW 72H 17/0600Z 22.9N 149.2W 30 KT 35 MPH...POST-TROP/REMNT LOW 96H 18/0600Z 23.5N 153.5W 30 KT 35 MPH...POST-TROP/REMNT LOW 120H 19/0600Z 24.5N 158.6W 25 KT 30 MPH...POST-TROP/REMNT LOW $$ Forecaster Roberts

Tags: number discussion storm tropical

 

Sites : [886] [887] [888] [889] [890] [891] [892] [893] [894] [895] [896] [897] [898] [899] [900] [901] [902] [903] [904] [905] next »