je.st
news
Tag: discussion
Hurricane Paulette Forecast Discussion Number 33
2020-09-15 04:35:49| National Hurricane Center (Atlantic)
Issued at 1100 PM AST Mon Sep 14 2020 000 WTNT42 KNHC 150235 TCDAT2 Hurricane Paulette Discussion Number 33 NWS National Hurricane Center Miami FL AL172020 1100 PM AST Mon Sep 14 2020 Paulette's cloud pattern has degraded during the past few hours, and recent microwave imagery suggests that the eyewall of the hurricane was at least for a time open to the south. A larger mostly closed ring of convection was also present, indicating that Paulette may be going through an eyewall replacement cycle. Satellite-based current intensity estimates range from 65 to 102 kt, but have generally decreased since the last advisory. The intensity estimate remains 90 kt at this time, but there is a high degree of uncertainty in this assessment. Assuming Paulette can maintain a well-defined inner core, either through the completion of an eyewall replacement cycle or redevelopment of convection in the southern eyewall, it should have an opportunity to strengthen during the next 24 h. The intensity guidance is not quite as bullish anymore, so the intensity forecast has been lowered slightly, but it is still above the intensity consensus through 36 h. Paulette could begin to lose tropical characteristics around that time and rapid weakening is expected as a result. The NHC forecast conservatively shows Paulette becoming fully post-tropical in 72 h, but there are indications from the GFS simulated satellite imagery that it could complete its transition sooner. Paulette has turned northeastward and is accelerating, as predicted, with an initial motion estimate of 35/15 kt. The system will likely race generally east-northeastward for the next few days. A slower motion and eventual turn southeastward or even southward is expected near the end of the week when the cyclone encounters a large cut-off low over the eastern Atlantic, however it should be post-tropical by that time. The track guidance remains in excellent overall agreement overall, and NHC forecast is based heavily on TVCN and HCCA. The wind radii analysis and forecast were updated based on data from an ASCAT-A overpass at 0050 UTC. FORECAST POSITIONS AND MAX WINDS INIT 15/0300Z 35.7N 62.3W 90 KT 105 MPH 12H 15/1200Z 37.4N 59.6W 100 KT 115 MPH 24H 16/0000Z 39.8N 54.4W 105 KT 120 MPH 36H 16/1200Z 42.3N 48.2W 95 KT 110 MPH 48H 17/0000Z 44.6N 41.9W 75 KT 85 MPH 60H 17/1200Z 46.0N 37.3W 60 KT 70 MPH 72H 18/0000Z 45.8N 35.6W 45 KT 50 MPH...POST-TROP/EXTRATROP 96H 19/0000Z 43.0N 33.5W 35 KT 40 MPH...POST-TROP/EXTRATROP 120H 20/0000Z 39.0N 32.0W 35 KT 40 MPH...POST-TROP/EXTRATROP $$ Forecaster Zelinsky
Tags: number
discussion
forecast
hurricane
Tropical Storm Teddy Forecast Discussion Number 10
2020-09-15 04:33:47| National Hurricane Center (Atlantic)
Issued at 1100 PM AST Mon Sep 14 2020 000 WTNT45 KNHC 150233 TCDAT5 Tropical Storm Teddy Discussion Number 10 NWS National Hurricane Center Miami FL AL202020 1100 PM AST Mon Sep 14 2020 Teddy is displaying some mixed signals this evening. On one hand, satellite imagery shows an improving cloud pattern, with increasing central convection and a large curved band on the southern side of the circulation. The latest TAFB/SAB Dvorak estimates have increased to 55 kt on this basis. Scatterometer data, surprisingly, only shows 35-40 kt. The initial wind speed remains 45 kt as a blend of that data, assuming the typical undersampling from ASCAT, but there is a fair bit of uncertainty in the current wind speed. Teddy should have several days in a low or moderate shear environment over warm waters to intensify. All guidance responds to this forcing by showing Teddy near major hurricane strength in a few days, with the biggest disagreement being how fast it gets there. The new forecast is similar to the previous one, leaning toward the NOAA corrected-consensus guidance HCCA. Teddy is moving about the same as before, or 280/11 kt. No substantial changes were made to the forecast track with the storm in a seemingly stable steering current provided by a deep-layer ridge over the central Atlantic. Teddy should turn west-northwestward overnight and then northwestward on Wednesday through the end of the forecast while it moves on the southwestern flank of the ridge. Model guidance is in excellent agreement, with only some minor speed differences. The NHC track prediction is basically on top of the previous one and the consensus aids. FORECAST POSITIONS AND MAX WINDS INIT 15/0300Z 13.2N 45.0W 45 KT 50 MPH 12H 15/1200Z 13.8N 46.5W 55 KT 65 MPH 24H 16/0000Z 14.8N 48.3W 70 KT 80 MPH 36H 16/1200Z 15.9N 49.8W 80 KT 90 MPH 48H 17/0000Z 17.3N 51.3W 90 KT 105 MPH 60H 17/1200Z 18.5N 52.6W 95 KT 110 MPH 72H 18/0000Z 19.9N 54.2W 105 KT 120 MPH 96H 19/0000Z 22.6N 56.9W 105 KT 120 MPH 120H 20/0000Z 25.5N 60.0W 105 KT 120 MPH $$ Forecaster Blake
Tags: number
discussion
storm
tropical
Tropical Storm Vicky Forecast Discussion Number 4
2020-09-15 04:33:17| National Hurricane Center (Atlantic)
Issued at 200 AM CVT Tue Sep 15 2020 000 WTNT41 KNHC 150233 TCDAT1 Tropical Storm Vicky Discussion Number 4 NWS National Hurricane Center Miami FL AL212020 200 AM CVT Tue Sep 15 2020 Vicky continues to be highly sheared due to strong upper- tropospheric flow associated with a nearby trough, and its associated deep convection is confined to a small cluster to the northeast of the center. An ASCAT overpass from a few hours ago showed an area of winds to just over 40 kt over the northern semicircle and, based on sampling limitations, the current intensity has been adjusted to 45 kt. The storm is not likely to maintain its intensity, since the dynamical guidance indicates that the shear over the cyclone will become even stronger during the next day or so. Therefore steady weakening is anticipated, and Vicky is likely to become a remnant low in about 36 hours. The official intensity forecast is near or slightly below the latest model consensus. Center fixes give a slow northwestward motion, or 315/6 kt. A narrow and weak low- to mid-level ridge to the north of Vicky should result in a northwestward to west-northwestward motion into early Wednesday. Thereafter, when the system will have probably have lost most of its deep convection, the shallow cyclone is likely to move mainly westward following the low-level environmental winds. The official track forecast is close to previous one and about in the middle of the guidance suite. FORECAST POSITIONS AND MAX WINDS INIT 15/0300Z 19.5N 29.9W 45 KT 50 MPH 12H 15/1200Z 20.5N 31.0W 40 KT 45 MPH 24H 16/0000Z 21.4N 32.7W 35 KT 40 MPH 36H 16/1200Z 22.0N 34.8W 30 KT 35 MPH...POST-TROP/REMNT LOW 48H 17/0000Z 22.3N 37.0W 30 KT 35 MPH...POST-TROP/REMNT LOW 60H 17/1200Z 22.5N 39.0W 25 KT 30 MPH...POST-TROP/REMNT LOW 72H 18/0000Z 22.5N 41.0W 25 KT 30 MPH...POST-TROP/REMNT LOW 96H 19/0000Z 22.5N 44.5W 20 KT 25 MPH...POST-TROP/REMNT LOW 120H 20/0000Z...DISSIPATED $$ Forecaster Pasch
Tags: number
discussion
storm
tropical
Tropical Storm Karina Forecast Discussion Number 8
2020-09-14 22:55:14| National Hurricane Center (East Pacific)
Issued at 200 PM PDT Mon Sep 14 2020 000 WTPZ41 KNHC 142055 TCDEP1 Tropical Storm Karina Discussion Number 8 NWS National Hurricane Center Miami FL EP162020 Issued by NWS Central Pacific Hurricane Center Honolulu HI 200 PM PDT Mon Sep 14 2020 The morning visible images showed Karina's partially obscured low level center under the northeast edge of the cyclone's deep convection. The displacement of the center is due to the ongoing presence of moderate vertical wind shear from the northeast. Cloud top temperatures have generally warmed through most of the morning, though the latest images showed a small burst of deep convection south of the center. An ASCAT pass this morning showed a large swath of 35 kt winds in the southeastern semicircle of Karina's circulation. The initial wind radii have been increased to account for the updated data. Dvorak fixes came in at 35 kt from SAB, and 45 kt from TAFB and PHFO. ASCAT peak winds were 37 kt. Based on a blend of these data, and little change in Karina's appearance in satellite imagery, the initial intensity will be held at 40 kt for this advisory. Moderate shear is expected to continue to affect Karina for another 24 hours. The shear will become weak from 36 to 72 hours, but by then the cyclone is expected to be over sub-26 degree C sea surface temperatures. Most of the objective aids indicate that peak intensity has been reached, and gradual weakening will occur after 24 hours. The intensity forecast closely follows HCCA, and has Karina becoming a post-tropical remnant low by 96 hours, if not sooner. This forecast trend keeps the intensity higher than the statistical guidance. The initial motion for this package is 305/9 kt. Karina is expected to continue moving northwestward to the southwest of a mid-level anticyclone. This motion is expected to continue through 60 to 72 hours. Karina should turn toward the southwest as deep convection ceases and the cyclone becomes steered by the low level flow. The forecast track has been adjusted a bit northward from the previous forecast, in part due to an adjustment in the initial position, and closely follows the HCCA guidance. FORECAST POSITIONS AND MAX WINDS INIT 14/2100Z 18.5N 118.8W 40 KT 45 MPH 12H 15/0600Z 19.4N 119.7W 40 KT 45 MPH 24H 15/1800Z 20.8N 121.2W 40 KT 45 MPH 36H 16/0600Z 21.9N 122.7W 35 KT 40 MPH 48H 16/1800Z 23.0N 124.2W 30 KT 35 MPH 60H 17/0600Z 23.7N 125.2W 25 KT 30 MPH 72H 17/1800Z 24.0N 125.9W 25 KT 30 MPH 96H 18/1800Z 23.5N 127.5W 25 KT 30 MPH...POST-TROP/REMNT LOW 120H 19/1800Z...DISSIPATED $$ Forecaster Kodama
Tags: number
discussion
storm
tropical
Hurricane Sally Forecast Discussion Number 14
2020-09-14 22:45:11| National Hurricane Center (Atlantic)
Issued at 400 PM CDT Mon Sep 14 2020 000 WTNT44 KNHC 142045 TCDAT4 Hurricane Sally Discussion Number 14 NWS National Hurricane Center Miami FL AL192020 400 PM CDT Mon Sep 14 2020 After the rapid spin up of the inner core late this morning, the most recent aircraft passes through the center have not found any higher flight-level winds, however there have been a few SFMR winds of 85-90 kt reported. Using a blend of the flight-level and SFMR winds the initial intensity has been increased to 85 kt for this advisory. The next Air Force and NOAA aircraft have begun to sample the storm. Now that Sally has developed an inner core, the favorable atmospheric and ocean conditions of low vertical wind shear and warm water should allow for additional strengthening tonight while the system moves over the north-central Gulf of Mexico, and Sally could approach major hurricane strength. On Tuesday, the global models are predicting an increasing in southwesterly flow aloft, and this increase in shear, the potential for land interaction, and some upwelling over the shallower shelf waters over the northern Gulf should slow the intensification process. The NHC intensity forecast is again near the upper-end of the guidance envelope in best agreement with the HWRF and HFIP corrected consensus models. Sally did not move much earlier today as the center re-formation took place, but it appears that a slow west-northwestward to northwestward motion has resumed. Weak ridging over the southeastern United States is expected to steer Sally generally west-northwestward through early Tuesday. After that time, steering currents weaken and a slow northward motion is forecast as a weak mid-level trough develops over the the central United States. This trough is forecast to slide eastward, allowing Sally to begin a slow north-northeastward or northeastward motion. The specific timing and location of the turn will be critical as to the eventual location and timing of landfall along the north-central Gulf Coast. The UKMET and ECMWF models show a more northeastward motion after the turn and have trended eastward, with the ECMWF much slower than the remainder of the guidance. The NHC track has been adjusted eastward, and this requires and eastward extension of the hurricane warning. The new track most closely follows the GFS and it ensemble mean, but lies to the west of the various consensus aids, so some additional eastward adjustments could be needed in subsequent advisories. Given the uncertainty in the timing and location of the northward turn and the lack of well-defined steering currents, users are reminded to not focus on the exact forecast track or the specific timing and location of landfall. Hurricane-force winds, dangerous storm surge, and flooding rainfall will affect a large portion of the north-central Gulf Coast during the next few days. KEY MESSAGES: 1. It is too early to determine where Sally's center will move onshore given the uncertainty in the timing and location of Sally's northward turn near the central Gulf Coast. Users should not focus on the details of the official forecast track, since NHC's average forecast error at 36 to 48 hours is around 60 to 80 miles, and dangerous storm surge, rainfall, and wind hazards will extend well away from the center. 2. An extremely dangerous and life-threatening storm surge is expected for areas outside the southeastern Louisiana Hurricane and Storm Damage Risk Reduction System from Port Fourchon, Louisiana, to the Okaloosa/Walton County Line in the Florida Panhandle, where a Storm Surge Warning is in effect. Residents in these areas should follow any advice given by local officials. 3. Hurricane conditions are expected late tonight or early Tuesday within the Hurricane Warning area in southeastern Louisiana and are expected by late Tuesday and Tuesday night within the Hurricane Warning area along the Mississippi and Alabama coastlines and the western Florida Panhandle. Tropical storm conditions are likely to begin this evening in these areas and preparations should be rushed to completion. 4. Life-threatening flash flooding is likely, as well as widespread minor to isolated major flooding, on area rivers along and just inland of the Central Gulf Coast. Significant flash and urban flooding, as well as widespread minor to moderate river flooding is likely across Mississippi and Alabama through the middle of the week. Flooding impacts are expected to spread farther across the Southeast through the week. Sally could continue to produce flash flooding across the Florida peninsula and prolong existing minor river flooding across west-central Florida through today. FORECAST POSITIONS AND MAX WINDS INIT 14/2100Z 28.8N 87.4W 85 KT 100 MPH 12H 15/0600Z 29.2N 88.2W 95 KT 110 MPH 24H 15/1800Z 29.7N 88.7W 95 KT 110 MPH 36H 16/0600Z 30.4N 88.6W 90 KT 105 MPH...INLAND 48H 16/1800Z 31.3N 88.0W 55 KT 65 MPH...INLAND 60H 17/0600Z 32.2N 86.8W 30 KT 35 MPH...INLAND 72H 17/1800Z 32.9N 85.5W 25 KT 30 MPH...INLAND 96H 18/1800Z 33.5N 83.0W 20 KT 25 MPH...POST-TROP/REMNT LOW 120H 19/1800Z...DISSIPATED $$ Forecaster Brown
Tags: number
discussion
forecast
hurricane
Sites : [193] [194] [195] [196] [197] [198] [199] [200] [201] [202] [203] [204] [205] [206] [207] [208] [209] [210] [211] [212] next »