Home › discussion
 

Keywords :   


Tag: discussion

Tropical Storm BLAS Forecast Discussion Number 26

2016-07-09 10:34:17| National Hurricane Center (East Pacific)

Issued at 200 AM PDT SAT JUL 09 2016 000 WTPZ43 KNHC 090834 TCDEP3 TROPICAL STORM BLAS DISCUSSION NUMBER 26 NWS NATIONAL HURRICANE CENTER MIAMI FL EP032016 200 AM PDT SAT JUL 09 2016 Blas continues to gradually weaken due to cool SSTs and increasing shear. Microwave imagery indicates that the low-level center is displaced 20 to 30 miles to the south of the mid-level center apparent in geostationary imagery. Dvorak classifications were T4.0/65 kt from TAFB and T3.5/55 kt from SAB, and the initial intensity is lowered to 60 kt based on a blend of these data. Quick weakening is forecast to continue while Blas moves over SSTs below 24C and southwesterly shear increases. Blas is forecast to become a remnant low in 36 hours and dissipate by day 5, and the new NHC intensity forecast is close to the latest IVCN intensity consensus. The above-mentioned microwave imagery showed that the low-level center was located a little south of previous estimates, and the adjusted best track yields an initial motion estimate of 310/08. The track forecast reasoning remains unchanged, as Blas should continue west-northwestward for the next 24 hours and then turn westward and eventually west-southwestward as the remnant low is steered by the low-level trade wind flow. The new NHC track is a little south of the previous through 36 hours given the initial position adjustment, and is close to the previous advisory after that time. This forecast is close to the multi-model consensus through much of the period. FORECAST POSITIONS AND MAX WINDS INIT 09/0900Z 19.5N 131.7W 60 KT 70 MPH 12H 09/1800Z 20.5N 132.9W 50 KT 60 MPH 24H 10/0600Z 21.3N 134.5W 40 KT 45 MPH 36H 10/1800Z 21.6N 136.5W 30 KT 35 MPH...POST-TROP/REMNT LOW 48H 11/0600Z 21.5N 138.6W 25 KT 30 MPH...POST-TROP/REMNT LOW 72H 12/0600Z 21.0N 143.0W 20 KT 25 MPH...POST-TROP/REMNT LOW 96H 13/0600Z 20.0N 147.5W 20 KT 25 MPH...POST-TROP/REMNT LOW 120H 14/0600Z...DISSIPATED $$ Forecaster Brennan

Tags: number discussion storm tropical

 

Tropical Storm CELIA Forecast Discussion Number 10

2016-07-09 04:35:14| National Hurricane Center (East Pacific)

Issued at 900 PM MDT FRI JUL 08 2016 000 WTPZ44 KNHC 090235 TCDEP4 TROPICAL STORM CELIA DISCUSSION NUMBER 10 NWS NATIONAL HURRICANE CENTER MIAMI FL EP042016 900 PM MDT FRI JUL 08 2016 Visible satellite imagery shows that Celia has an expansive cloud shield, with a compact CDO feature and multiple elongated cloud bands. However, deep convection is disjointed and fairly limited near the low-level center. Dvorak intensity estimates from TAFB and SAB are unchanged from six hours ago, and the CIMSS ADT estimate has actually decreased during that time. Therefore, the initial intensity is left at 40 kt. Celia's center temporarily moved northward earlier today, but the average motion over the past 12 hours is estimated to be northwestward, or 305/8 kt. A subtropical ridge extending westward from northern Mexico should cause Celia to resume a west- northwestward to westward motion but at a faster forward speed through day 3. The cyclone is expected to reach the southwestern periphery of the ridge by day 4, which should cause Celia to turn northwestward by the end of the forecast period. The track model spread is low, especially through day 3, and the NHC track forecast is very close to the various consensus models. This updated forecast is a little north of the previous one during the first 24 hours to account for Celia's recent northward jog. High-resolution microwave SST data indicate that Celia's center is now moving over the coldest portion of Blas's cold wake, which could be contributing to the relative lack of central deep convection. Celia will continue moving over the cold wake for another day or so, and only gradual strengthening is anticipated in the short term. Warmer waters and low shear should allow faster intensification to begin in 36-48 hours, with Celia likely reaching its peak intensity in about 3 days. Cooler waters should then induce a gradual weakening trend on days 4 and 5. In light of the latest guidance, no significant changes were made to the previous NHC intensity forecast. FORECAST POSITIONS AND MAX WINDS INIT 09/0300Z 13.7N 114.1W 40 KT 45 MPH 12H 09/1200Z 14.2N 115.8W 45 KT 50 MPH 24H 10/0000Z 14.5N 118.1W 50 KT 60 MPH 36H 10/1200Z 14.6N 120.5W 60 KT 70 MPH 48H 11/0000Z 14.7N 122.9W 75 KT 85 MPH 72H 12/0000Z 15.5N 127.3W 90 KT 105 MPH 96H 13/0000Z 17.0N 131.0W 85 KT 100 MPH 120H 14/0000Z 19.5N 135.0W 70 KT 80 MPH $$ Forecaster Berg

Tags: number discussion storm tropical

 
 

Hurricane BLAS Forecast Discussion Number 25

2016-07-09 04:33:43| National Hurricane Center (East Pacific)

Issued at 800 PM PDT FRI JUL 08 2016 000 WTPZ43 KNHC 090233 TCDEP3 HURRICANE BLAS DISCUSSION NUMBER 25 NWS NATIONAL HURRICANE CENTER MIAMI FL EP032016 800 PM PDT FRI JUL 08 2016 Blas has continued to move over increasingly cooler waters, and although the convection has been on a general weakening trend, the hurricane still has a vigorous circulation as indicated by ASCAT earlier today. A blend of subjective and objective Dvorak numbers from all agencies supports an initial intensity of 70 kt. In addition to the effect of cooler waters, the shear is forecast to increase. Recent microwave imagery suggests that the low-level center is south of the convection, indicating that the shear is already increasing. These factors should result in faster weakening, and Blas is expected to become a remnant low by Sunday or sooner. In fact, SHIPS and LGEM basically dissipate the cyclone in 48 hours or so. The cyclone is moving toward the northwest or 325 degrees at about 10 kt around the southwestern periphery of the Pacific subtropical ridge, and this general track is forecast to continue for a day or so. In about 36 hours or less, Blas should have become a shallow system and will likely be steered westward and west-southwestward by the low-level trade winds. Most of the models have been fairly consistent with this scenario for a while, and there are no obvious reasons to vary from earlier NHC forecasts. FORECAST POSITIONS AND MAX WINDS INIT 09/0300Z 19.2N 131.0W 70 KT 80 MPH 12H 09/1200Z 20.2N 132.0W 60 KT 70 MPH 24H 10/0000Z 21.3N 133.5W 45 KT 50 MPH 36H 10/1200Z 21.8N 135.2W 30 KT 35 MPH...POST-TROP/REMNT LOW 48H 11/0000Z 21.7N 137.1W 25 KT 30 MPH...POST-TROP/REMNT LOW 72H 12/0000Z 21.0N 141.5W 25 KT 30 MPH...POST-TROP/REMNT LOW 96H 13/0000Z 20.0N 145.5W 20 KT 25 MPH...POST-TROP/REMNT LOW 120H 14/0000Z...DISSIPATED $$ Forecaster Avila

Tags: number discussion forecast hurricane

 

Hurricane BLAS Forecast Discussion Number 24

2016-07-08 22:34:43| National Hurricane Center (East Pacific)

Issued at 200 PM PDT FRI JUL 08 2016 000 WTPZ43 KNHC 082034 TCDEP3 HURRICANE BLAS DISCUSSION NUMBER 24 NWS NATIONAL HURRICANE CENTER MIAMI FL EP032016 200 PM PDT FRI JUL 08 2016 Cool waters are taking a toll on Blas. The satellite presentation of the hurricane has degraded since this morning as the convective cloud tops have warmed and steadily decreased in coverage. Dvorak intensity estimates continue to decrease and the initial wind speed has been reduced to 75 kt, which is blend of the latest subjective T- and CI-numbers from TAFB and SAB. The hurricane should continue to quickly weaken while it moves over water below 24C and into a more stable environment during the next several days. The latest intensity forecast is close to the SHIPS/LGEM guidance, and calls for Blas to weaken to a tropical storm tonight, and become a post-tropical cyclone in about 36 hours. Recent center fixes show that Blas has turned northwestward. The cyclone should continue moving northwestward during the next day or so into a weakness in the subtropical ridge caused by a large mid- to upper-level low to the northeast of Hawaii. By Sunday, the post-tropical cyclone is forecast to turn back westward in the low-level easterly flow. The guidance is in good agreement on this scenario and the updated track forecast is essentially an update of the previous NHC advisory. The initial wind radii have been adjusted based on a recent ASCAT pass. FORECAST POSITIONS AND MAX WINDS INIT 08/2100Z 18.5N 130.5W 75 KT 85 MPH 12H 09/0600Z 19.7N 131.5W 60 KT 70 MPH 24H 09/1800Z 21.0N 132.8W 45 KT 50 MPH 36H 10/0600Z 21.8N 134.3W 35 KT 40 MPH...POST-TROPICAL 48H 10/1800Z 22.0N 136.2W 30 KT 35 MPH...POST-TROP/REMNT LOW 72H 11/1800Z 21.5N 140.5W 25 KT 30 MPH...POST-TROP/REMNT LOW 96H 12/1800Z 20.5N 144.5W 20 KT 25 MPH...POST-TROP/REMNT LOW 120H 13/1800Z...DISSIPATED $$ Forecaster Brown

Tags: number discussion forecast hurricane

 

Tropical Storm CELIA Forecast Discussion Number 8

2016-07-08 16:52:11| National Hurricane Center (East Pacific)

Issued at 900 AM MDT FRI JUL 08 2016 000 WTPZ44 KNHC 081452 TCDEP4 TROPICAL STORM CELIA DISCUSSION NUMBER 8 NWS NATIONAL HURRICANE CENTER MIAMI FL EP042016 900 AM MDT FRI JUL 08 2016 The cloud pattern of the tropical depression has become better organized, with first-light visible imagery showing a ragged central dense overcast surrounded by a complex of outer bands. Subjective Dvorak intensity estimates are 30-35 kt, while AMSU and Advanced Dvorak technique estimates from CIMSS are near 50 kt. Based on this, the depression is upgraded to Tropical Storm Celia with winds of 40 kt. The initial motion is 275/6. There is little change from the forecast philosophy from the previous advisory. Celia should be steered westward with an increase in forward speed by a building subtropical ridge to the north through the next 2 to 3 days. After that time, a west-northwestward turn is forecast as the system nears the southwestern edge of the ridge. The guidance has nudged a little to the north for the first 36 hours or so, and thus this part of the forecast track is also adjusted northward. Otherwise, the track is an update of the previous NHC advisory. Celia is forecast to be in an environment of light vertical wind shear for the next 3-4 days. However, during the next 24-36 hours the cyclone will pass near or over an area of cooler sea surface temperatures left in the wake of Hurricane Blas. This should slow intensification during this time. The storm is expected to reach warmer water from 36-96 hours and significant strengthening is expected at that time. The intensity forecast calls for a peak intensity of 90 kt, which is below that forecast by the SHIPS and LGEM models. From 96-120 hours, Celia should again encounter cooler sea surface temperatures, which should cause the cyclone to weaken. FORECAST POSITIONS AND MAX WINDS INIT 08/1500Z 12.6N 112.8W 40 KT 45 MPH 12H 09/0000Z 12.9N 114.0W 45 KT 50 MPH 24H 09/1200Z 13.3N 116.0W 50 KT 60 MPH 36H 10/0000Z 13.5N 118.1W 55 KT 65 MPH 48H 10/1200Z 13.8N 120.4W 65 KT 75 MPH 72H 11/1200Z 14.5N 125.0W 90 KT 105 MPH 96H 12/1200Z 16.0N 129.0W 90 KT 105 MPH 120H 13/1200Z 17.5N 133.0W 75 KT 85 MPH $$ Forecaster Beven

Tags: number discussion storm tropical

 

Sites : [894] [895] [896] [897] [898] [899] [900] [901] [902] [903] [904] [905] [906] [907] [908] [909] [910] [911] [912] [913] next »