Home › discussion
 

Keywords :   


Tag: discussion

Tropical Storm Kirk Forecast Discussion Number 5

2018-09-23 16:31:32| National Hurricane Center (Atlantic)

Issued at 1100 AM AST Sun Sep 23 2018 730 WTNT42 KNHC 231431 TCDAT2 Tropical Storm Kirk Discussion Number 5 NWS National Hurricane Center Miami FL AL122018 1100 AM AST Sun Sep 23 2018 Kirk's cloud pattern has a figure 6 configuration, with most of the deep convective bands over the western semicircle of the circulation. Microwave imagery indicates that the center is near the eastern side of the main area of deep convection, as before. Dvorak classifications from both TAFB and SAB support keeping the intensity at 35 kt. The storm will be moving over warmer waters with fairly low shear for the next day or two, so some strengthening is anticipated in the short term. Later in the forecast period, increasing westerly shear should cause weakening. The official intensity forecast is similar to the model consensus through 48 hours, and follows the trends shown by the ECMWF and GFS global guidance thereafter. The latter models suggest that Kirk could open up into a trough when it nears the Caribbean. Center fixes indicate that Kirk has been accelerating westward and the initial motion estimate is now 280/18 kt. A well-defined mid-level ridge to the north of the cyclone should cause an even faster westward motion over the next few days. Near the end of the forecast period, a weakness in the ridge is likely to lead to a slowing of the forward speed. The official forecast is a blend of the latest simple and corrected model consensus forecast tracks and is also similar to the previous NHC track. FORECAST POSITIONS AND MAX WINDS INIT 23/1500Z 9.3N 30.2W 35 KT 40 MPH 12H 24/0000Z 9.8N 33.2W 40 KT 45 MPH 24H 24/1200Z 10.2N 37.3W 45 KT 50 MPH 36H 25/0000Z 10.5N 41.5W 50 KT 60 MPH 48H 25/1200Z 10.7N 45.6W 50 KT 60 MPH 72H 26/1200Z 11.2N 52.4W 45 KT 50 MPH 96H 27/1200Z 12.3N 57.5W 40 KT 45 MPH 120H 28/1200Z 13.5N 62.0W 35 KT 40 MPH $$ Forecaster Pasch

Tags: number discussion storm tropical

 

Tropical Storm Kirk Forecast Discussion Number 4

2018-09-23 10:33:59| National Hurricane Center (Atlantic)

Issued at 500 AM AST Sun Sep 23 2018 523 WTNT42 KNHC 230833 TCDAT2 Tropical Storm Kirk Discussion Number 4 NWS National Hurricane Center Miami FL AL122018 500 AM AST Sun Sep 23 2018 Recent microwave data show that Kirk's center is located near the eastern edge of the deep convection. There are a few curved bands trying to form, but overall the convective activity is oriented along an east-west line extending west of the center. Since Dvorak classifications from TAFB and SAB are T2.5, the initial intensity remains 35 kt. Kirk has been accelerating since yesterday, and the current motion is westward, or 280 degrees, at 16 kt. Low- to mid-level ridging over the eastern Atlantic is expected to cause Kirk to move even faster toward the west during the next couple of days, reaching speeds of at least 22 kt in 24-36 hours. A reduction in speed is likely after 48 hours once Kirk moves south of a large central Atlantic trough, but it should still be moving along at a pretty good clip. The forecast thinking is the same as in previous advisories, with the latest NHC track forecast still closely following a blend of the GFS, ECMWF, and HFIP Corrected Consensus model along the southern edge of the guidance envelope. This new prediction is a little faster than what was indicated in the previous advisory. Kirk will be moving over increasingly warmer waters and through a relatively low-shear environment for the next 2-3 days, which should allow for some strengthening. The biggest limiting factors for intensification would be the cyclone's fast motion and possible entrainment of dry air. Like every other tropical cyclone which has approached the Lesser Antilles from the east this season, Kirk is expected to run into strong westerly shear in 4-5 days, resulting in weakening as the cyclone gets closer to the islands. The NHC official forecast is still not as high as the statistical-dynamical guidance and more closely follows the HCCA, Florida State Superensemble, and intensity consensus, as well as the trends in the GFS and ECMWF. Based on those global models, it is possible that Kirk may open up into a trough as it is approaching the Lesser Antilles and moving into the eastern Caribbean Sea, but for now the official forecast maintains Kirk as a tropical storm through day 5. FORECAST POSITIONS AND MAX WINDS INIT 23/0900Z 9.1N 28.0W 35 KT 40 MPH 12H 23/1800Z 9.5N 30.7W 40 KT 45 MPH 24H 24/0600Z 10.0N 35.1W 45 KT 50 MPH 36H 24/1800Z 10.2N 39.5W 50 KT 60 MPH 48H 25/0600Z 10.4N 43.7W 50 KT 60 MPH 72H 26/0600Z 10.9N 51.0W 45 KT 50 MPH 96H 27/0600Z 12.0N 57.0W 40 KT 45 MPH 120H 28/0600Z 13.0N 61.5W 35 KT 40 MPH $$ Forecaster Berg

Tags: number discussion storm tropical

 
 

Tropical Depression Eleven Forecast Discussion Number 6

2018-09-23 10:32:31| National Hurricane Center (Atlantic)

Issued at 500 AM AST Sun Sep 23 2018 959 WTNT41 KNHC 230832 TCDAT1 Tropical Depression Eleven Discussion Number 6 NWS National Hurricane Center Miami FL AL112018 500 AM AST Sun Sep 23 2018 Satellite images indicate that the depression is poorly organized. The circulation is becoming increasingly elongated, and it seems likely that a closed circulation may no longer exist. However, we are maintaining advisories for now to wait for visible imagery to better assess the low-level circulation. The depression continues to produce a few patches of deep convection, but these are confined to the east and northeast portions of the circulation due to about 35 kt of westerly shear. The initial intensity remains 25 kt based on the earlier ASCAT data. The system is moving into an environment of even stronger westerly wind shear. These hostile winds and dry air should cause the depression to dissipate, if it has not already, later today or tonight. The depression, or its remnants, are expected to move slowly west-northwestward for another day or so. FORECAST POSITIONS AND MAX WINDS INIT 23/0900Z 14.5N 55.0W 25 KT 30 MPH 12H 23/1800Z 15.0N 56.0W 25 KT 30 MPH 24H 24/0600Z...DISSIPATED $$ Forecaster Cangialosi

Tags: number discussion tropical depression

 

Tropical Storm Kirk Forecast Discussion Number 3

2018-09-23 04:43:57| National Hurricane Center (Atlantic)

Issued at 1100 PM AST Sat Sep 22 2018 605 WTNT42 KNHC 230243 TCDAT2 Tropical Storm Kirk Discussion Number 3 NWS National Hurricane Center Miami FL AL122018 1100 PM AST Sat Sep 22 2018 The overall organization of Kirk has changed little since the previous advisory. The deep convection that was over the western portion of the circulation has continued to race westward ahead of the low-level center while a new burst of convection has developed closer to the center this evening. A couple of ASCAT passes from just prior to 0000 UTC did not reveal any winds as strong as this morning, but given the recent increase in convection near the center the initial intensity is maintained at 35 kt, which could be a little generous. Recent satellite fixes show that Kirk is moving west-northwestward or 285 degrees at 14 kt. A narrow subtropical ridge that is forecast to build westward to the north of Kirk should steer the cyclone quickly westward during the next few days, with forward speeds increasing to around 20-22 kt. After that time, the global models predict that a weakness will develop in the ridge between 50W and 60W which is forecast to cause Kirk to slow down and turn west-northwestward. The updated NHC track forecast is a little north of the previous advisory, primarily due to a slightly more northward initial position as noted in the ASCAT data. Otherwise, the track forecast is similar to the previous advisory and is along the southern edge of the guidance, closest to a blend of the GFS and ECMWF, and the HFIP corrected consensus. Kirk is forecast to traverse warm waters and remain within a low shear environment during the next couple of days. These conditions favor strengthening, however as mentioned in the previous discussion, some dry air lurking just to the north of Kirk could get entrained into the circulation and limit intensification. There is still large spread in the intensity guidance with the statistical guidance showing much more intensification between 24 and 72 h. After 72 hours, increasing westerly shear is expected to cause weakening. The NHC intensity forecast remains near the HCCA and IVCN intensity guidance, and follows the trend of the ECMWF and GFS models that weaken Kirk later in the forecast period. Given the spread in the guidance, the intensity forecast is of low confidence. FORECAST POSITIONS AND MAX WINDS INIT 23/0300Z 9.0N 26.4W 35 KT 40 MPH 12H 23/1200Z 9.4N 28.9W 40 KT 45 MPH 24H 24/0000Z 9.9N 33.0W 45 KT 50 MPH 36H 24/1200Z 10.1N 37.3W 50 KT 60 MPH 48H 25/0000Z 10.2N 41.8W 50 KT 60 MPH 72H 26/0000Z 10.6N 49.5W 50 KT 60 MPH 96H 27/0000Z 11.8N 55.0W 45 KT 50 MPH 120H 28/0000Z 13.3N 60.0W 40 KT 45 MPH $$ Forecaster Brown

Tags: number discussion storm tropical

 

Tropical Depression Eleven Forecast Discussion Number 5

2018-09-23 04:35:31| National Hurricane Center (Atlantic)

Issued at 1100 PM AST Sat Sep 22 2018 082 WTNT41 KNHC 230235 TCDAT1 Tropical Depression Eleven Discussion Number 5 NWS National Hurricane Center Miami FL AL112018 1100 PM AST Sat Sep 22 2018 Although deep convection has increased since earlier today, it has become increasingly difficult to identify a well-defined center associated with the depression. After moving erratically during the afternoon, the center of the depression appears to have become disrupted by convection to its east, and it is unclear at this point if a closed surface circulation still exists. Since visible imagery is not currently available and recent ASCAT data from around 0000Z was inconclusive, at least one more advisory will be issued under the assumption that the depression has not quite yet dissipated. The initial motion is highly uncertain, but it is assumed that the system is still moving generally northwestward, or 310/3 kt. No substantial changes were made to the NHC intensity or track forecasts. All available guidance indicates that the depression will continue to move slowly west-northwestward or northwestward for the next day or two while it gradually weakens due to continued strong wind shear. Given the recent increase in convection, it no longer seems likely that the system will become a remnant low prior to dissipating. Therefore, the NHC forecast now keeps the system as a tropical depression until dissipation occurs in 36 h, if not sooner. FORECAST POSITIONS AND MAX WINDS INIT 23/0300Z 13.8N 54.5W 25 KT 30 MPH 12H 23/1200Z 14.2N 55.3W 25 KT 30 MPH 24H 24/0000Z 14.5N 56.6W 20 KT 25 MPH 36H 24/1200Z...DISSIPATED $$ Forecaster Zelinsky

Tags: number discussion tropical depression

 

Sites : [491] [492] [493] [494] [495] [496] [497] [498] [499] [500] [501] [502] [503] [504] [505] [506] [507] [508] [509] [510] next »