je.st
news
Tag: discussion
Tropical Storm KARL Forecast Discussion Number 23
2016-09-20 04:43:06| National Hurricane Center (Atlantic)
Issued at 1100 PM AST MON SEP 19 2016 000 WTNT42 KNHC 200242 TCDAT2 TROPICAL STORM KARL DISCUSSION NUMBER 23 NWS NATIONAL HURRICANE CENTER MIAMI FL AL122016 1100 PM AST MON SEP 19 2016 Karl is a little better organized tonight. An area of deep convection has been persisting during the past several hours, and microwave images indicate that the center is located near the southwestern edge of the convective area. The initial wind speed is nudged upward to 40 kt, following a blend of the latest Dvorak classifications from TAFB and SAB. Karl is moving west-northwestward at 11 kt, and it is being steered by the flow on the south side of a high pressure system over the subtropical Atlantic. The tropical cyclone is expected to move near the southwestern periphery of the high in a couple of days and then head toward a pronounced weakness in the ridge over the western Atlantic. This change in the steering pattern should result in Karl turning northwestward in about 48 hours, with a gradual turn to the north and northeast expected in 4 to 5 days. Although the models agree on the overall theme, there is a fair amount of spread in the guidance associated with where and when Karl begins to recurve. The NHC official track forecast is near the middle of the guidance envelope, and is in best agreement with the various consensus aids. The vertical wind shear that has been affecting Karl for the past several days appears to be letting up some, and the SHIPS model suggests that shear should be generally light during the next 5 days. In addition, Karl is currently over SSTs of around 28 deg C, and it is expected to move over even warmer waters throughout the forecast period. The one unfavorable parameter for intensification is the dry mid-level environment surrounding the tropical storm, but some of the guidance suggests that the air mass could moisten ahead of the system later this week. Based on these large scale conditions, slow strengthening seems likely during the next day or so, followed by a faster rate of intensification thereafter. The NHC intensity forecast is higher than the previous one, but is on the conservative side of the guidance at the longer range forecast points. FORECAST POSITIONS AND MAX WINDS INIT 20/0300Z 19.7N 50.5W 40 KT 45 MPH 12H 20/1200Z 20.4N 52.4W 45 KT 50 MPH 24H 21/0000Z 21.3N 54.9W 45 KT 50 MPH 36H 21/1200Z 22.4N 57.3W 50 KT 60 MPH 48H 22/0000Z 23.9N 59.7W 55 KT 65 MPH 72H 23/0000Z 26.7N 63.5W 70 KT 80 MPH 96H 24/0000Z 29.5N 64.5W 85 KT 100 MPH 120H 25/0000Z 32.3N 60.3W 95 KT 110 MPH $$ Forecaster Cangialosi
Tags: number
discussion
storm
karl
Tropical Depression THIRTEEN Forecast Discussion Number 1
2016-09-19 22:53:34| National Hurricane Center (Atlantic)
Issued at 500 PM AST MON SEP 19 2016 000 WTNT43 KNHC 192053 TCDAT3 TROPICAL DEPRESSION THIRTEEN DISCUSSION NUMBER 1 NWS NATIONAL HURRICANE CENTER MIAMI FL AL132016 500 PM AST MON SEP 19 2016 Satellite imagery, scatterometer data, and ship observations indicate that the large low pressure system located southwest of the Cabo Verde Islands has maintained a well-defined circulation and has developed sufficient organized convection to be considered a tropical depression. The initial intensity is set at 30 kt based on scatterometer wind data of near 30 kt along with Dvorak satellite intensity estimates T2.5/35 kt and T2.0/30 kt from TAFB and SAB, respectively. The central pressure is based on reports from ship D5ET2 during is traversal through the center of the cyclone over the past 12 hours. The depression is a large tropical cyclone with a wind field that is more than 400 n mi in diameter. The initial motion estimate is an uncertain 280/10 kt, based primarily on scatterometer and microwave satellite data. The depression is located along the southern periphery of a large deep-layer ridge that is foreast to steer the cyclone westward for the next 24 hours or so, followed by west-northwestward motion through 120 hours. The official forecast track lies close to the consensus model TVCN through 96 hours, and then leans toward a blend of the ECMWF, UKMET, and CMC models since the GFS dissipates the cyclone by 120 hours, a scenario that seems premature given the current large size of the cyclone. Vertical wind shear is forecast to remain low at less than 10 kt over the cyclone for the next 48 hours, which favors steady intensification. However, the mid-level moisture is only expected to be marginal during that time, with humidity values around 60 percent or less. The drier air along with the large size of the cyclone are expected to temper the development process, and this is reflected by the slower-than-average intensification rate. The NHC intensity forecast closely follows the intensity model IVCN. This forecast is lower than the SHIPS, LGEM, and ECMWF models, which brings the cyclone to near hurricane strength by 72 hours. FORECAST POSITIONS AND MAX WINDS INIT 19/2100Z 13.6N 28.6W 30 KT 35 MPH 12H 20/0600Z 14.3N 29.8W 35 KT 40 MPH 24H 20/1800Z 15.6N 31.8W 40 KT 45 MPH 36H 21/0600Z 16.7N 33.5W 45 KT 50 MPH 48H 21/1800Z 17.6N 35.4W 50 KT 60 MPH 72H 22/1800Z 19.5N 38.9W 45 KT 50 MPH 96H 23/1800Z 21.5N 42.5W 35 KT 40 MPH 120H 24/1800Z 23.5N 44.7W 30 KT 35 MPH $$ Forecaster Stewart
Tags: number
discussion
tropical
depression
Hurricane PAINE Forecast Discussion Number 8
2016-09-19 22:46:01| Tropical Depression LIDIA
Issued at 200 PM PDT MON SEP 19 2016
Tags: number
discussion
forecast
hurricane
Hurricane PAINE Forecast Discussion Number 7
2016-09-19 16:49:33| Tropical Depression LIDIA
Issued at 800 AM PDT MON SEP 19 2016
Tags: number
discussion
forecast
hurricane
Tropical Storm KARL Forecast Discussion Number 21
2016-09-19 16:48:46| National Hurricane Center (Atlantic)
Issued at 1100 AM AST MON SEP 19 2016 000 WTNT42 KNHC 191448 TCDAT2 TROPICAL STORM KARL DISCUSSION NUMBER 21 NWS NATIONAL HURRICANE CENTER MIAMI FL AL122016 ISSUED BY THE NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 1100 AM AST MON SEP 19 2016 Visible satellite imagery shows Karl consists of a swirl of low clouds with nearly all of the associated deep convection located to the northeast of the exposed low-level center. The structure has changed relatively little from six hours ago, and the initial wind speed remains 35 kt based on the Dvorak Current Intensity estimate from TAFB. Karl is still being affected by 10-15 kt of southwesterly vertical shear, and with the mid-level relative humidity in the surrounding environment only 40-50 percent, the cyclone continues to struggle to produce deep convection near its center and over the western part of the circulation. However, the SHIPS guidance indicates that the shear should continue to decrease during the next few days, and mid-level moisture is likely to increase over 60 percent by day 3. Therefore, only slight strengthening is anticipated during the next 48 hours, but that should be followed by quicker intensification on days 3-5, with Karl still expected to reach hurricane intensity by the end of the forecast period. The updated official intensity forecast is very close to the SHIPS guidance for the entire forecast period, and it is just slightly below the previous forecast after 24 hours. The initial motion is just a little slower at 275/11 kt. Karl's westward motion is the result of it being positioned south of the Bermuda-Azores high. However, the cyclone is expected to reach a break in the ridge located over the western Atlantic in a few days, which will cause it to turn northwestward by day 3 and then northward by day 5. The track models are tightly clustered through day 3 before Karl makes its turn, but there is more spread on days 4 and 5 regarding where the turn will occur. The GFS and GFS ensemble mean both take Karl farther west before it turns toward the north, while the bulk of the other models make the turn east of the previous forecast track. For the sake of continuity, the updated official track forecast is very similar to the previous forecast, and it lies relatively close to a consensus of the GFS and ECMWF models. FORECAST POSITIONS AND MAX WINDS INIT 19/1500Z 18.6N 48.3W 35 KT 40 MPH 12H 20/0000Z 18.9N 50.3W 35 KT 40 MPH 24H 20/1200Z 19.5N 52.8W 40 KT 45 MPH 36H 21/0000Z 20.4N 55.2W 40 KT 45 MPH 48H 21/1200Z 21.6N 57.7W 45 KT 50 MPH 72H 22/1200Z 24.5N 62.3W 55 KT 65 MPH 96H 23/1200Z 27.5N 65.5W 70 KT 80 MPH 120H 24/1200Z 29.5N 65.0W 80 KT 90 MPH $$ Forecaster Berg
Tags: number
discussion
storm
karl
Sites : [807] [808] [809] [810] [811] [812] [813] [814] [815] [816] [817] [818] [819] [820] [821] [822] [823] [824] [825] [826] next »