je.st
news
Tag: discussion
Tropical Depression Seventeen-E Forecast Discussion Number 4
2018-09-01 22:55:40| Tropical Depression LIDIA
Issued at 300 PM MDT Sat Sep 01 2018
Tags: number
discussion
tropical
depression
Hurricane Norman Forecast Discussion Number 19
2018-09-01 22:54:42| National Hurricane Center (East Pacific)
Issued at 200 PM PDT Sat Sep 01 2018 538 WTPZ41 KNHC 012054 TCDEP1 Hurricane Norman Discussion Number 19 NWS National Hurricane Center Miami FL EP162018 200 PM PDT Sat Sep 01 2018 Since the previous advisory, a well-defined closed eye has remained apparent in microwave satellite data, and a cloud-filled eye has appeared in visible satellite imagery during the past couple of hours. Satellite intensity estimated haven't changed since the previous advisory, so the initial intensity remains 90 kt, which is supported by a 1501Z SATCON estimate of 88 kt and a Dvorak CI value of T5.0/90 kt. Norman's initial motion estimate is now 275/12 kt based on microwave and visible satellite eye position estimates. There are no significant changes to the previous track forecast and reasoning. The hurricane is expected to be steered by a strong deep-layer subtropical ridge to the north, resulting in a westward motion for the next 12-24 hours, followed by a west-northwestward motion at a faster forward speed. The latest model guidance is tightly packed about the previous forecast track through 96 hours, with much less divergence after that compared to previous model runs. Therefore, the new forecast track is essentially just an extension of the previous advisory track, and lies close to a blend of the HCCA, FSSE, and TVCE consensus track models. The GFS and ECMWF models are forecasting the 15-20 kt of vertical wind shear that has been affecting Norman to steadily decrease for the next 60-72 hours, possibly becoming near zero if the ECMWF upper-level wind forecasts verify. Since the hurricane is expected to remain over 27 deg C and warmer SSTs for the next 48 hours, only slow weakening is forecast and that is due mainly to occasional intrusions of drier and more stable air coming in from the northwest, where a large field of cold-air stratocumulus clouds is currently lurking close by. The HWRF and HMON models continue to forecast Norman to re-strengthen into a major hurricane during the next 24 hours, but this scenario is being discounted at this time due to Norman's proximity to the aforementioned stratocumulus cloud field. By 72 hours, increasing southwesterly shear and cooler SSTs should combine to induce more significant weakening. The NHC intensity forecast is similar to the HCCA and IVCN consensus model forecasts. FORECAST POSITIONS AND MAX WINDS INIT 01/2100Z 16.3N 125.1W 90 KT 105 MPH 12H 02/0600Z 16.6N 127.0W 90 KT 105 MPH 24H 02/1800Z 17.4N 130.1W 85 KT 100 MPH 36H 03/0600Z 18.2N 133.2W 85 KT 100 MPH 48H 03/1800Z 19.1N 136.5W 80 KT 90 MPH 72H 04/1800Z 20.4N 142.0W 70 KT 80 MPH 96H 05/1800Z 21.4N 146.4W 65 KT 75 MPH 120H 06/1800Z 22.2N 149.6W 60 KT 70 MPH $$ Forecaster Stewart
Tags: number
discussion
forecast
norman
Tropical Storm Florence Forecast Discussion Number 10
2018-09-01 22:34:11| National Hurricane Center (Atlantic)
Issued at 500 PM AST Sat Sep 01 2018 386 WTNT41 KNHC 012034 TCDAT1 Tropical Storm Florence Discussion Number 10 NWS National Hurricane Center Miami FL AL062018 500 PM AST Sat Sep 01 2018 The cloud pattern has continued to improve with a circular area of convection near the center, and a cyclonically curved band surrounding the system. The upper-level outflow is fair in all quadrants. Although the cloud pattern is better organized, the Dvorak T-numbers have not changed, and only support 40 kt at this time. Florence has a couple of more days embedded within a low-shear environment which supports strengthening, but it is also currently heading toward marginal SSTs. By the time the cyclone reaches warmer waters again, the shear is forecast to be unfavorable. The best option at this time is to show only a very modest strengthening at the rate indicated by the intensity consensus aids. Florence has been moving toward the west-northwest or 285 degrees at 12 to 14 kt. No change in track is anticipated during the next 3 days while Florence is located to the south of the Atlantic subtropical ridge. After that time, Florence will reach a break in the ridge causing the cyclone to turn toward the northwest with a decrease in forward speed. The latter portion of the forecast is uncertain since the strength of the subtropical ridge to the north has been fluctuating from run to run in each model. At this time, the overall guidance has been shifting a little bit westward, suggesting a stronger ridge. On this basis, the NHC forecast was adjusted slightly in that direction at the end of the forecast period. FORECAST POSITIONS AND MAX WINDS INIT 01/2100Z 15.6N 29.0W 40 KT 45 MPH 12H 02/0600Z 16.2N 31.0W 45 KT 50 MPH 24H 02/1800Z 16.8N 33.7W 50 KT 60 MPH 36H 03/0600Z 17.5N 36.5W 55 KT 65 MPH 48H 03/1800Z 18.0N 39.0W 55 KT 65 MPH 72H 04/1800Z 19.5N 43.5W 55 KT 65 MPH 96H 05/1800Z 21.5N 48.0W 50 KT 60 MPH 120H 06/1800Z 23.5N 52.0W 50 KT 60 MPH $$ Forecaster Avila
Tags: number
discussion
storm
tropical
Tropical Depression Seventeen-E Forecast Discussion Number 3
2018-09-01 17:02:08| Tropical Depression LIDIA
Issued at 900 AM MDT Sat Sep 01 2018
Tags: number
discussion
tropical
depression
Hurricane Norman Forecast Discussion Number 18
2018-09-01 16:54:39| National Hurricane Center (East Pacific)
Issued at 800 AM PDT Sat Sep 01 2018 734 WTPZ41 KNHC 011454 TCDEP1 Hurricane Norman Discussion Number 18 NWS National Hurricane Center Miami FL EP162018 800 AM PDT Sat Sep 01 2018 Although satellite intensity estimates indicate that Norman has continued to weaken, the weakening trend appears to have abated. This is based on recent infrared imagery showing a better developed CDO feature accompanied by improved outflow, and also a well-defined closed eye now depicted in a 1148Z AMSR and 1158Z SSMIS microwave satellite images. The initial intensity has been lowered to 90 kt, which is a blend of the various satellite intensity estimates, with a little more weight placed on the TAFB estimate of T5.0/90 kt. Norman's initial motion estimate is 270/10 kt. The aforementioned eye noted in the microwave passes greatly helped with determining the cyclone's location and past motion. Other than some slight forward speed adjustments made in the first 24 hours due to the faster initial motion, no significant changes were required to the previous track forecast. Norman is forecast to move westward to west-northwestward for the next several days as the hurricane moves along the southern periphery of strong deep-layer ridge to the north. The models are in excellent agreement on the track of Norman through 72 h, and then diverge noticeably after that time with the GFS taking Norman more westward in the general direction of the Hawaiian Islands, whereas the ECMWF, HWRF, and HMON models keep Norman well to the northeast of the islands. The official forecast track lies close to the middle of the tightly packed guidance envelope through 72 h, and then is close to the consensus aids HCCA and FSSE after that. The shear that has been affecting Norman appears to have weakened some this morning, and that decreasing trend is expected to continue throughout the forecast period, becoming near zero in 48-72 h according to the ECMWF model. The GFS model shows a similar decreasing shear trend, but just not as much as the ECMWF model. The HWRF and HMON models also have the shear decreasing and do a complete reversal by re-strengthening Norman into a major hurricane again during the next 24 h, followed by slow weakening thereafter. For now, the official intensity forecast shows little change in strength for the next 24 h, followed by slow weakening during the remainder of the forecast period as the cyclone encounters drier air and cooler sea-surface temperatures near 26C. FORECAST POSITIONS AND MAX WINDS INIT 01/1500Z 16.2N 123.7W 90 KT 105 MPH 12H 02/0000Z 16.3N 125.4W 90 KT 105 MPH 24H 02/1200Z 16.9N 128.2W 90 KT 105 MPH 36H 03/0000Z 17.8N 131.3W 85 KT 100 MPH 48H 03/1200Z 18.7N 134.6W 85 KT 100 MPH 72H 04/1200Z 20.3N 140.6W 70 KT 80 MPH 96H 05/1200Z 21.3N 145.3W 65 KT 75 MPH 120H 06/1200Z 22.0N 148.6W 60 KT 70 MPH $$ Forecaster Stewart
Tags: number
discussion
forecast
norman
Sites : [538] [539] [540] [541] [542] [543] [544] [545] [546] [547] [548] [549] [550] [551] [552] [553] [554] [555] [556] [557] next »