je.st
news
Tag: discussion
Tropical Storm KARL Forecast Discussion Number 27
2016-09-21 04:38:42| National Hurricane Center (Atlantic)
Issued at 1100 PM AST TUE SEP 20 2016 000 WTNT42 KNHC 210238 TCDAT2 TROPICAL STORM KARL DISCUSSION NUMBER 27 NWS NATIONAL HURRICANE CENTER MIAMI FL AL122016 1100 PM AST TUE SEP 20 2016 Karl continues to struggle this evening. Satellite images indicate that the low-level center of the storm is completely exposed to the southwest of the main area of deep convection. The NOAA Hurricane Hunters investigated Karl earlier this evening and found that the maximum winds were still around 35 kt, though a very recent ASCAT pass suggests that this estimate could be a bit generous. Dropsonde data and model vertical cross sections indicate that Karl is being affected by mid-level southwesterly flow and dry air induced by a cut-off low pressure system located a few hundred miles to the west. These unfavorable atmospheric conditions have been affecting the cyclone during the past several days and until these conditions abate, little change in the structure or strength of Karl is anticipated. The models insist that environment should become less hostile in about 24 h, and Karl should have its best opportunity to intensify late this week and this weekend when it moves into an area of baroclinic forcing. The NHC intensity forecast is identical to the previous one, and lies near the middle of the guidance envelope. The tropical storm has moved basically due west during the past 24 hours. A turn toward the northwest should occur on Wednesday when the cyclone nears the southwestern periphery of a deep-layer ridge, followed by a northward motion in about 3 days when Karl rounds the ridge and moves into a pronounced weakness. By the end of the forecast period, a sharp increase in speed and turn to the northeast are expected as a large-scale mid-latitude trough picks up the tropical cyclone. There are significant forward speed differences in the models associated with how Karl interacts with the large-scale trough in the 3 to 5 day time frame, and the NHC forecast is of low confidence during that period. FORECAST POSITIONS AND MAX WINDS INIT 21/0300Z 19.9N 56.7W 35 KT 40 MPH 12H 21/1200Z 20.9N 58.2W 35 KT 40 MPH 24H 22/0000Z 22.9N 60.7W 40 KT 45 MPH 36H 22/1200Z 24.5N 62.9W 45 KT 50 MPH 48H 23/0000Z 25.9N 64.8W 55 KT 65 MPH 72H 24/0000Z 29.0N 65.0W 70 KT 80 MPH 96H 25/0000Z 32.9N 59.6W 85 KT 100 MPH 120H 26/0000Z 39.2N 48.2W 80 KT 90 MPH $$ Forecaster Cangialosi
Tags: number
discussion
storm
karl
Tropical Storm KARL Forecast Discussion Number 26
2016-09-20 22:44:45| National Hurricane Center (Atlantic)
Issued at 500 PM AST TUE SEP 20 2016 000 WTNT42 KNHC 202044 TCDAT2 TROPICAL STORM KARL DISCUSSION NUMBER 26 NWS NATIONAL HURRICANE CENTER MIAMI FL AL122016 ISSUED BY THE NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 500 PM AST TUE SEP 20 2016 Karl's center had lost some definition throughout the day, but deep convection has redeveloped near the center late in the afternoon. Dvorak Current Intensity estimates were lowered to 2.5 from TAFB and 2.0 from SAB, and the latest UW-CIMSS ADT estimate is T3.2. A NOAA P-3 flight currently conducting a research mission into Karl has not yet found tropical-storm-force winds, but it has not sampled the entire circulation yet. The initial intensity is therefore held at 35 kt pending additional data from the P-3. The minimum pressure is lowered to 1005 mb based on dropsonde data from the NOAA G-IV jet, which is also flying near Karl. Little to no change is expected in the strength of Karl over the next 24 hours as the influence of an upper low continues to shear out the western side of the storm. The global models indicate that the shear should relax in the next 24 to 36 hours allowing a slight strengthening in that period. As Karl rounds the mid-level ridge it will find itself in a more favorable environment with warm SSTs and lower shear. An increased rate of intensification should take place in the 48 to 72 hour time frame, and Karl is expected to reach hurricane strength by the end of that period. The official intensity forecast has been nudged slightly downward based on the latest guidance, however it is still on the upper end of the guidance spread. The center of Karl continues pushing west near the 20th parallel with an initial motion of 275 at 12 kt. Karl is expected to make a turn toward the west-northwest shortly and should reach the western edge of the subtropical high during the next 48 hours, turning to the northwest by day 2 and to the north by day 4. Karl will then accelerate to the northeast as it gets picked up by the westerlies ahead of an upper level trough. Global model guidance continues to show considerable spread into the day 5 period. The ECMWF is significantly slower than the other models because the upper level trough does not pick up Karl. The official track forecast follows close to the previous forecast and remains near a consensus of the GFS and ECMWF. FORECAST POSITIONS AND MAX WINDS INIT 20/2100Z 20.1N 55.2W 35 KT 40 MPH 12H 21/0600Z 20.8N 57.0W 35 KT 40 MPH 24H 21/1800Z 22.3N 59.2W 40 KT 45 MPH 36H 22/0600Z 24.1N 61.4W 45 KT 50 MPH 48H 22/1800Z 25.6N 63.5W 55 KT 65 MPH 72H 23/1800Z 28.5N 65.5W 70 KT 80 MPH 96H 24/1800Z 32.5N 61.5W 85 KT 100 MPH 120H 25/1800Z 38.5N 51.0W 80 KT 90 MPH $$ Forecaster Krekeler/Berg
Tags: number
discussion
storm
karl
Tropical Depression PAINE Forecast Discussion Number 12
2016-09-20 22:44:39| Tropical Depression LIDIA
Issued at 200 PM PDT TUE SEP 20 2016
Tags: number
discussion
tropical
depression
Tropical Storm LISA Forecast Discussion Number 5
2016-09-20 22:43:15| National Hurricane Center (Atlantic)
Issued at 500 PM AST TUE SEP 20 2016 000 WTNT43 KNHC 202042 TCDAT3 TROPICAL STORM LISA DISCUSSION NUMBER 5 NWS NATIONAL HURRICANE CENTER MIAMI FL AL132016 500 PM AST TUE SEP 20 2016 During the past six hours, a central dense overcast (CDO) feature has developed over and to the east of Lisa's low-level center. The upper-level outflow has also improved, albeit elongated northeast- to-southwest. The initial intensity has been increased to 40 kt, which is a blend of a Dvorak satellite intensity estimate of T2.5/35 kt from TAFB, a UW-CIMSS ADT values of T2.9/43 kt, and a 1611Z AMSU estimate of 44 kt. The initial motion estimate is 315/10 kt. Lisa has made a jog to the right of the previous forecast track and model guidance, which is most likely due to the center reforming closer to the strongest convection. Other than shifting the forecast track to the right of the previous advisory track to account for the more eastward initial position, the forecast rationale remains unchanged. The latest NHC model guidance continues to indicate a steady northwestward motion for the next four days toward a break in the subtropical ridge between 30W-40W longitude. On day 5, Lisa is expected to move northward as the ridge erodes eastward. The new NHC forecast track lies down the middle of the tightly packed guidance envelope through day 4, and then follows a blend of the ECMWF and HWRF models on day 5 since those models maintain the cyclone longer. Lisa has another 36 hours or so to strengthen some more before the large-scale environment becomes very unfavorable, which will be characterized by southwesterly vertical wind shear of 25-30 kt, drier and more stable air, and SSTs less than 27 deg C. It is possible that Lisa could end up being a little stronger between the 24- and 36-hour forecast periods. By 48 hours, however, steady weakening is expected to ensue, with Lisa becoming a remnant low pressure system by 120 hours. The intensity forecast closely follows the intensity consensus model IVCN. FORECAST POSITIONS AND MAX WINDS INIT 20/2100Z 16.4N 31.0W 40 KT 45 MPH 12H 21/0600Z 17.2N 32.1W 45 KT 50 MPH 24H 21/1800Z 18.1N 33.6W 50 KT 60 MPH 36H 22/0600Z 19.0N 35.0W 50 KT 60 MPH 48H 22/1800Z 20.0N 36.5W 45 KT 50 MPH 72H 23/1800Z 22.7N 39.2W 35 KT 40 MPH 96H 24/1800Z 25.2N 42.0W 30 KT 35 MPH 120H 25/1800Z 29.2N 44.0W 25 KT 30 MPH...POST-TROP/REMNT LOW $$ Forecaster Stewart
Tags: number
discussion
storm
lisa
Tropical Storm LISA Forecast Discussion Number 4
2016-09-20 17:04:31| National Hurricane Center (Atlantic)
Issued at 1100 AM AST TUE SEP 20 2016 000 WTNT43 KNHC 201503 CCA TCDAT3 TROPICAL STORM LISA DISCUSSION NUMBER 4...CORRECTED NWS NATIONAL HURRICANE CENTER MIAMI FL AL132016 1100 AM AST TUE SEP 20 2016 CORRECTED LISA TO BE TWELFTH NAMED STORM The cloud pattern of the cyclone has steadily improved, with long curved bands having developed in the northern semicircle since the previous advisory. Although Dvorak satellite classifications from TAFB and SAB were 30 kt at 1200Z, recent UW-CIMSS ADT values have increased to 35 kt and AMSU intensity estimates range from 35-45 kt. Therefore the initial intensity has been increased to 35 kt, which is a compromise of these estimates, making the cyclone the twelfth named storm of the 2016 hurricane season. Visible satellite imagery indicates that Tropical Storm Lisa is now moving northwestward or 305/10 kt. Water vapor imagery and satellite-derived winds indicate that a large mid-latitude trough extends from near the Canary Islands southwestward into the tropics, which has created a break in the subtropical ridge along 30W-40W longitude. Lisa is forecast to move generally northwestward toward the break in the ridge for the next 4 days, followed by a northward turn as the cyclone moves around the western periphery of the ridge axis. The latest model guidance remains in good agreement on this track scenario, and the new NHC forecast track is just a little to the right of the previous advisory track, mainly to account for the more northward initial position, and lies close to the consensus model TVCN. Lisa has about 48 hours remaining to strengthen while the vertical wind shear and upper-level outflow pattern remain favorable, and sea-surface temperatures are above 27 deg C. However, a marginally moist mid-level environment and the large size of the cyclone are expected to prevent any rapid strengthening from occuring. After that time, the atmosphere is expected to become quite hostile, characterized by southwesterly shear of 25-30 kt and much drier mid-level air, resulting in steady weakening from 72-120 hours. Although the dynamical guidance continues to forecast some relaxation of the shear toward the end of the period, the cyclone will likely be too degraded to recover. The official intensity forecast is close to the SHIPS model through 48 hours, and then lies closer to the LGEM guidance after that. FORECAST POSITIONS AND MAX WINDS INIT 20/1500Z 15.3N 30.4W 35 KT 40 MPH 12H 21/0000Z 16.2N 31.5W 35 KT 40 MPH 24H 21/1200Z 17.3N 33.2W 40 KT 45 MPH 36H 22/0000Z 18.2N 35.0W 45 KT 50 MPH 48H 22/1200Z 19.1N 36.4W 50 KT 60 MPH 72H 23/1200Z 21.7N 39.0W 40 KT 45 MPH 96H 24/1200Z 24.5N 41.4W 30 KT 35 MPH 120H 25/1200Z 28.3N 43.6W 25 KT 30 MPH...POST-TROP/REMNT LOW $$ Forecaster Stewart
Tags: number
discussion
storm
lisa
Sites : [805] [806] [807] [808] [809] [810] [811] [812] [813] [814] [815] [816] [817] [818] [819] [820] [821] [822] [823] [824] next »