je.st
news
Tag: discussion
Tropical Storm Karen Forecast Discussion Number 16
2019-09-26 04:34:37| National Hurricane Center (Atlantic)
Issued at 1100 PM AST Wed Sep 25 2019 000 WTNT42 KNHC 260234 TCDAT2 Tropical Storm Karen Discussion Number 16 NWS National Hurricane Center Miami FL AL122019 1100 PM AST Wed Sep 25 2019 Karen's cloud pattern is basically shapeless and consists of a tight swirl of low clouds located at the northern end of a curved-convective band. Dvorak T-numbers barely support 35 kt, but it is assumed that a few spots of tropical storm-force-wind are still occuring in the southeast quadrant. Karen has had enough time to strengthen, and it is doubtful that it will do it in the future. The cyclone is heading toward an unfavorable environment and each consecutive run of the global models show a weaker and weaker cyclone. My predecessor wisely stated in the advisory "it is time to put more weight in the global models" and I will do so in this one. On this basis, the NHC forecast no longer calls for strengthening, and maintains Karen generously with 35 kt for the next 2 days or so. It also calls for weakening thereafter. Karen is forecast to be a remnant low in about 4 days, but is very likely that this could occur much sooner. The best estimate of the initial motion is toward the north- northeast or 015 degrees at 13 kt. The cyclone is being steered by the flow between a mid-level trough over the Bahamas and a subtropical ridge to the east. In two days, the steering flow is expected to collapse, and Karen will likely meander for a day or so. A ridge will then build to the north, and since Karen will be weak and shallow, the cyclone or its remnants will move westward, steered by the trade winds south of the ridge and toward very hostile upper-level winds. FORECAST POSITIONS AND MAX WINDS INIT 26/0300Z 24.4N 63.6W 35 KT 40 MPH 12H 26/1200Z 26.0N 62.9W 35 KT 40 MPH 24H 27/0000Z 27.5N 62.0W 35 KT 40 MPH 36H 27/1200Z 28.0N 61.0W 35 KT 40 MPH 48H 28/0000Z 28.3N 60.0W 35 KT 40 MPH 72H 29/0000Z 27.5N 61.5W 30 KT 35 MPH 96H 30/0000Z 26.6N 64.5W 25 KT 30 MPH...POST-TROP/REMNT LOW 120H 01/0000Z 26.5N 67.0W 25 KT 30 MPH...POST-TROP/REMNT LOW $$ Forecaster Avila
Tags: number
discussion
storm
karen
Hurricane Lorenzo Forecast Discussion Number 12
2019-09-25 22:41:36| National Hurricane Center (Atlantic)
Issued at 500 PM AST Wed Sep 25 2019 000 WTNT43 KNHC 252041 TCDAT3 Hurricane Lorenzo Discussion Number 12 NWS National Hurricane Center Miami FL AL132019 500 PM AST Wed Sep 25 2019 Conventional satellite imagery indicates that Lorenzo continues to become better organized, with the central dense overcast getting larger while a large complex of outer bands continues in the southeastern semicircle. In addition, a AMSR-2 overpass near 1530 UTC suggested there is at least a partial eyewall or convective ring near the center. The initial intensity is increased to 80 kt in best agreement with the CIMSS satellite consensus intensity estimate. The hurricane still shows good cirrus outflow in all directions, and it still appears some dry air is entraining into the system in the northwestern quadrant. The initial motion is now 285/16. There is no change to the track forecast philosophy from the previous advisory. The subtropical ridge to the north and northeast of Lorenzo should steer the hurricane west-northwestward for the next day or so, followed by a turn toward the northwest as a break develops in the ridge between 45W-50W. Lorenzo is subsequently forecast to turn northward into the break by 96 h and recurve into the westerlies around 120 h. Since the last advisory, the track guidance has shifted a little to the right after 36 h. The new forecast track is similar to the previous track, but after 36 h it now lies a little to the left of the center of the guidance envelope. Lorenzo should remain over warm water and in a light shear environment during the next three days, with the only negative factor for intensification being episodic intrusions of dry air. The intensity guidance forecasts continued steady strengthening for the next 36 h or so, but the the chances of rapid intensification in the various statistical indices have gone down since the previous advisory. The new intensity forecast will call for 36 more hours of intensification, and it continues to lie near the upper edge of the intensity guidance. The intensity forecast follows the general trend of the guidance in showing little change in strength between 36-96 h, although fluctuations in intensity are likely due to eyewall replacement cycles during this time. After that time, Lorenzo is likely to encounter southwesterly shear, and thus some weakening is forecast. FORECAST POSITIONS AND MAX WINDS INIT 25/2100Z 14.5N 36.9W 80 KT 90 MPH 12H 26/0600Z 15.0N 38.7W 90 KT 105 MPH 24H 26/1800Z 16.1N 40.5W 105 KT 120 MPH 36H 27/0600Z 17.7N 41.8W 110 KT 125 MPH 48H 27/1800Z 19.5N 43.0W 110 KT 125 MPH 72H 28/1800Z 23.0N 44.3W 105 KT 120 MPH 96H 29/1800Z 26.5N 43.5W 105 KT 120 MPH 120H 30/1800Z 31.0N 40.5W 100 KT 115 MPH $$ Forecaster Beven
Tags: number
discussion
forecast
hurricane
Post-Tropical Cyclone Jerry Forecast Discussion Number 34
2019-09-25 22:38:56| National Hurricane Center (Atlantic)
Issued at 500 PM AST Wed Sep 25 2019 716 WTNT45 KNHC 252038 TCDAT5 Post-Tropical Cyclone Jerry Discussion Number 34 NWS National Hurricane Center Miami FL AL102019 500 PM AST Wed Sep 25 2019 Multiple scatterometer passes over Jerry indicate that the cyclone no longer has sustained tropical-storm-force winds. Therefore Jerry is now a remnant low, and the Bermuda Weather Service has discontinued the Tropical Storm Warning for Bermuda. However, wind gusts to tropical storm force are still possible on the island during the next few hours, especially at elevated observing sites. Based on the scatterometer data, the current intensity is estimated to be 30 kt. The low-cloud swirl is becoming less well-defined, and since the system will continue moving through a hostile environment of strong shear and dry mid-level air, steady weakening is likely. The cyclone should dissipate in 2-3 days. The NHC intensity forecast is close to the latest intensity model consensus. The system is moving east-northeastward at a slightly faster clip, or 070/10 kt. A gradual turn to the east and east-southeast is forecast as the cyclone moves along the southern edge of the band of mid-latitude westerlies, and then turns to the right along the northeastern periphery of a subtropical anticyclone before dissipating. This is the last advisory on Jerry. FORECAST POSITIONS AND MAX WINDS INIT 25/2100Z 32.2N 65.6W 30 KT 35 MPH...POST-TROP/REMNT LOW 12H 26/0600Z 32.8N 63.8W 30 KT 35 MPH...POST-TROP/REMNT LOW 24H 26/1800Z 33.7N 61.5W 25 KT 30 MPH...POST-TROP/REMNT LOW 36H 27/0600Z 34.7N 59.0W 25 KT 30 MPH...POST-TROP/REMNT LOW 48H 27/1800Z 35.0N 56.5W 20 KT 25 MPH...POST-TROP/REMNT LOW 72H 28/1800Z...DISSIPATED $$ Forecaster Pasch
Tags: number
discussion
jerry
forecast
Tropical Storm Karen Forecast Discussion Number 15
2019-09-25 22:37:34| National Hurricane Center (Atlantic)
Issued at 500 PM AST Wed Sep 25 2019 000 WTNT42 KNHC 252037 TCDAT2 Tropical Storm Karen Discussion Number 15 NWS National Hurricane Center Miami FL AL122019 500 PM AST Wed Sep 25 2019 An Air Force Reserve Hurricane Hunter aircraft investigating Karen found maximum 850-mb flight-level winds of 43 kt, and SFMR-measured winds of 34 kt. Although those surface winds were coincident with some heavy rains, which makes them questionable, it is assumed that there are still some tropical-storm-force winds somewhere within the circulation. The initial intensity has been lowered to 35 kt. Karen has turned toward the north-northeast with an initial motion of 015/12 kt. The cyclone is positioned between a mid-level high centered over the central Atlantic and a mid- to upper-level low spinning just east of the Bahamas. The steering flow between these two features should keep Karen on a generally northeastward trajectory during the next 48 hours. Around that time, a blocking ridge is expected to build to the north of Karen, causing it to make a clockwise loop and move west-southwestward by days 4 and 5. Compared to the previous cycle, the track models are allowing Karen to get farther to the northeast before it makes its loop, which ends up slowing down the 4- and 5-day NHC forecast points. Even with that change, however, the forecast path of Karen is relatively unchanged from before. It's probably time to put more weight on the dynamical models for Karen's future intensity. The cyclone has continued to struggle in its environment, which is essentially what those models have been indicating all along. Even the statistical-dynamical models, which are explicitly showing strengthening, indicate that the environment won't be very favorable, with convergence aloft and a dry mid-level air mass. Because of those factors, and the lower initial intensity, the NHC intensity forecast has been lowered considerably from this morning's forecast. It still allows for the possibility of some strengthening, but if model trends continue, the official forecast could be lowered further in subsequent advisories. And if the global models are correct, Karen could even lose deep convection, and hence become post-tropical, in about 3 days. FORECAST POSITIONS AND MAX WINDS INIT 25/2100Z 22.9N 64.3W 35 KT 40 MPH 12H 26/0600Z 24.6N 63.9W 35 KT 40 MPH 24H 26/1800Z 26.5N 63.0W 35 KT 40 MPH 36H 27/0600Z 27.6N 61.8W 40 KT 45 MPH 48H 27/1800Z 27.9N 60.8W 40 KT 45 MPH 72H 28/1800Z 27.5N 60.5W 40 KT 45 MPH 96H 29/1800Z 26.5N 63.5W 40 KT 45 MPH 120H 30/1800Z 26.0N 67.0W 35 KT 40 MPH $$ Forecaster Berg
Tags: number
discussion
storm
karen
Post-Tropical Cyclone Jerry Forecast Discussion Number 33
2019-09-25 16:59:54| National Hurricane Center (Atlantic)
Issued at 1100 AM AST Wed Sep 25 2019 000 WTNT45 KNHC 251459 TCDAT5 Post-Tropical Cyclone Jerry Discussion Number 33 NWS National Hurricane Center Miami FL AL102019 1100 AM AST Wed Sep 25 2019 Jerry remains devoid of deep convection in an environment of dry mid-level air and strong westerly shear. Data from a new scatterometer pass indicate that the maximum winds are no more than 35 kt, and even that value could be generous. The system should remain in a hostile environment for the next few days, and simulated satellite imagery from the global models suggest that no significant deep convection will redevelop within it. Therefore the official intensity forecast calls for the cyclone to gradually spin down over the next 2-3 days. The NHC intensity forecast is just slightly below the model consensus. The cyclone has turned toward the east-northeast with some increase in forward speed, and the initial motion estimate is 060/8 kt. Jerry should continue to move east-northeastward, to the south of the main belt of mid-latitude westerlies, for the next day or two. Later in the forecast period, the weak cyclone is expected to turn east-southeastward along the northeastern periphery of a subtropical high pressure area, and dissipate. The official track forecast continues to follow the NOAA corrected consensus guidance rather closely. Key Messages: 1. Tropical-storm-force winds are expected on Bermuda later today. Large swells are also expected to affect the coast of Bermuda during the next few days. These swells could cause life-threatening rip currents. See products issued by the Bermuda Weather Service for more information. FORECAST POSITIONS AND MAX WINDS INIT 25/1500Z 32.0N 66.8W 35 KT 40 MPH...POST-TROPICAL 12H 26/0000Z 32.6N 65.1W 35 KT 40 MPH...POST-TROPICAL 24H 26/1200Z 33.4N 62.9W 30 KT 35 MPH...POST-TROP/REMNT LOW 36H 27/0000Z 34.3N 60.4W 25 KT 30 MPH...POST-TROP/REMNT LOW 48H 27/1200Z 34.9N 58.0W 25 KT 30 MPH...POST-TROP/REMNT LOW 72H 28/1200Z 33.8N 54.5W 20 KT 25 MPH...POST-TROP/REMNT LOW 96H 29/1200Z...DISSIPATED $$ Forecaster Pasch
Tags: number
discussion
jerry
forecast
Sites : [329] [330] [331] [332] [333] [334] [335] [336] [337] [338] [339] [340] [341] [342] [343] [344] [345] [346] [347] [348] next »