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Tropical Depression Ten-E Forecast Discussion Number 7

2020-08-14 22:54:39| National Hurricane Center (East Pacific)

Issued at 200 PM PDT Fri Aug 14 2020 000 WTPZ45 KNHC 142054 TCDEP5 Tropical Depression Ten-E Discussion Number 7 NWS National Hurricane Center Miami FL EP102020 200 PM PDT Fri Aug 14 2020 ASCAT-B data valid around 1900 UTC showed max winds a little higher than 30 kt associated with the rain-free circulation of the depression. However, since that time, the convective structure of the cyclone has degraded substantially and if it was previously producing winds of tropical-storm-force, it likely no longer is doing so at this time. Therefore, the initial intensity for this advisory is held at 30 kt. Only minor fluctuations in the intensity and structure of the depression are expected for the next 3 days due to strong northeasterly wind shear. Assuming the system doesn't dissipate at some point during that period of time, the upper-level winds could become less hostile early next week. The dynamical guidance generally indicates that the tropical cyclone will hang on and modest strengthening is possible early next week. No changes were made to the NHC intensity forecast, which closely follows the multi-model consensus. Likewise, only minor adjustments were made to the NHC track forecast. The depression is still forecast to meander for the next 5 days, initially west-southwestward to westward, then northwestward over the weekend. The strength of a low- to mid-level ridge to the north of the cyclone is the primary factor in the steering flow. While there are slight variations from model to model on the speed and heading of the tropical cyclone, they all agree that it won't move much through the early portion of next week, and possibly even beyond that. The NHC forecast essentially splits the difference between the previous official forecast, HCCA, and TVCE. FORECAST POSITIONS AND MAX WINDS INIT 14/2100Z 13.5N 132.7W 30 KT 35 MPH 12H 15/0600Z 13.3N 133.1W 30 KT 35 MPH 24H 15/1800Z 13.2N 133.4W 30 KT 35 MPH 36H 16/0600Z 13.4N 133.8W 30 KT 35 MPH 48H 16/1800Z 13.8N 134.2W 30 KT 35 MPH 60H 17/0600Z 14.2N 134.5W 30 KT 35 MPH 72H 17/1800Z 14.5N 135.1W 30 KT 35 MPH 96H 18/1800Z 14.6N 135.7W 35 KT 40 MPH 120H 19/1800Z 14.5N 136.5W 35 KT 40 MPH $$ Forecaster Zelinsky

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Tropical Storm Kyle Forecast Discussion Number 1

2020-08-14 22:41:12| National Hurricane Center (Atlantic)

Issued at 500 PM EDT Fri Aug 14 2020 000 WTNT42 KNHC 142041 TCDAT2 Tropical Storm Kyle Discussion Number 1 NWS National Hurricane Center Miami FL AL122020 500 PM EDT Fri Aug 14 2020 Earlier this afternoon, one-minute visible satellite imagery clearly showed that an area of low pressure off the mid-Atlantic coast of the U.S. had developed a well defined center. Banding convection wraps from the northeast to the southeast quadrant of the cyclone, and a combination of surface obs, ship reports, and buoy data all indicate that the system is not frontal. Although its organization is limited by strong southwesterly upper-level winds, the convection appears to be sufficiently well organized to classify the system as a tropical cyclone. Earlier ASCAT data indicated that the maximum winds were between 30 and 35 kt, so the initial intensity is set at 35 kt, assuming some slight undersampling may have occurred. Kyle is the earliest 11th named storm on record for the Atlantic basin. The previous record was Katrina, which became a tropical storm on August 24, 2005. Kyle is moving quickly east-northeastward along the northern portion of the Gulf Stream, and its future as a tropical cyclone is likely tied to how long it remains over those warm waters. A mid-latitude trough will continue to steer the system generally east-northeastward for the next few days, with some increase in forward speed. This will cause the storm to move quickly northeastward away from the U.S. coast and well south of the Canadian Maritimes. As long as the tropical cyclone remains over warm waters, some strengthening is possible, and this is reflected in all of the intensity guidance. That said, strong upper-level winds will likely keep the system sufficiently sheared to prevent significant tropical strengthening. Extratropical transition is forecast to begin within 48 h, and should be complete by 60 h. Sometime around or just after 72 h, the low is forecast to either merge with or be absorbed by a larger extratropical low pressure system over the North Atlantic. The NHC intensity forecast is based on the multi-model consensus, with a little extra weight given to the global models for the extratropical phase. FORECAST POSITIONS AND MAX WINDS INIT 14/2100Z 37.7N 71.7W 35 KT 40 MPH 12H 15/0600Z 38.7N 69.0W 40 KT 45 MPH 24H 15/1800Z 40.0N 64.6W 45 KT 50 MPH 36H 16/0600Z 41.4N 60.2W 45 KT 50 MPH 48H 16/1800Z 42.4N 56.0W 45 KT 50 MPH 60H 17/0600Z 43.1N 51.5W 45 KT 50 MPH...POST-TROP/EXTRATROP 72H 17/1800Z 43.1N 46.0W 40 KT 45 MPH...POST-TROP/EXTRATROP 96H 18/1800Z...DISSIPATED $$ Forecaster Zelinsky

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Tropical Storm Josephine Forecast Discussion Number 13

2020-08-14 22:36:07| National Hurricane Center (Atlantic)

Issued at 500 PM AST Fri Aug 14 2020 000 WTNT41 KNHC 142035 TCDAT1 Tropical Storm Josephine Discussion Number 13 NWS National Hurricane Center Miami FL AL112020 500 PM AST Fri Aug 14 2020 An Air Force Reserve Hurricane Hunter aircraft reported that the circulation of Josephine was still closed, and that the center was a little farther to the north than previously thought - possibly due to reformation close to a strong convective burst. The aircraft reported a minimum pressure of 1004 mb, and the combination of flight-level and SFMR winds support an initial intensity of 35 kt. Satellite imagery indicates that Josephine is encountering increasing westerly shear, with cirrus clouds west of the storm blowing into the cyclone. Aside from the nudge to the north, the initial motion is generally west-northwestward or 300/14 kt. There is again no change to the track forecast philosophy. Josephine should continue a west- northwestward motion as it approaches a weakness in the subtropical ridge in 48-60 h. Then, the cyclone should gradually turn northward and move through the weakness in 72-96 h. Late in the forecast period, Josephine or its remnants are expected to turn north-northeastward along the southern edge of the mid-latitude westerlies. Portions of the forecast track have been adjusted northward based mainly on the initial position, and the new forecast track lies close to the various consensus models. The increasing shear means that Josephine is just about out of time to intensify. The intensity forecast calls for a little strengthening tonight in case a convective burst causes some spin up. After that, the cyclone should weaken, with the new forecast showing it becoming a depression in 48 h and a remnant low by 96 hr. The global models continue to forecast a faster weakening, and there is still the alternative scenario that Josephine could decay to a tropical wave before 96 h. KEY MESSAGES: 1. Josephine should pass far enough to the northeast of the Leeward Islands over the weekend to prevent major impacts. However, interests there should continue to monitor its progress until the storm has passed north of that area. 2. Locally heavy rainfall is possible in the northern Leeward Islands, the Virgin Islands, and Puerto Rico as Josephine passes by to the northeast. Isolated minor flooding is possible in Puerto Rico through Monday. FORECAST POSITIONS AND MAX WINDS INIT 14/2100Z 17.8N 56.1W 35 KT 40 MPH 12H 15/0600Z 18.6N 58.0W 40 KT 45 MPH 24H 15/1800Z 19.9N 60.5W 40 KT 45 MPH 36H 16/0600Z 21.1N 62.9W 35 KT 40 MPH 48H 16/1800Z 22.5N 65.1W 30 KT 35 MPH 60H 17/0600Z 24.1N 66.7W 30 KT 35 MPH 72H 17/1800Z 25.7N 67.7W 25 KT 30 MPH 96H 18/1800Z 28.6N 67.5W 25 KT 30 MPH...POST-TROP/REMNT LOW 120H 19/1800Z 32.1N 65.5W 20 KT 25 MPH...POST-TROP/REMNT LOW $$ Forecaster Beven

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Tropical Storm Josephine Forecast Discussion Number 12

2020-08-14 16:41:35| National Hurricane Center (Atlantic)

Issued at 1100 AM AST Fri Aug 14 2020 000 WTNT41 KNHC 141441 TCDAT1 Tropical Storm Josephine Discussion Number 12 NWS National Hurricane Center Miami FL AL112020 1100 AM AST Fri Aug 14 2020 Morning visible satellite imagery indicates that the center of Josephine is located to the south or southwest of the strongest area of convection, likely due to the onset of southwesterly vertical wind shear. A just-received scatterometer pass supports an initial intensity of 35 kt, but also suggests the possibility that the circulation is longer closed. An Air Force Reserve Hurricane Hunter aircraft is scheduled to investigate Josephine this afternoon to provide more information on the intensity and whether a closed circulation still exists. The initial motion continues west-northwestward or 295/14 kt. Josephine should continue this general motion as it approaches a weakness in the subtropical ridge in 48-60 h. Then, the cyclone should turn northward and move through the weakness in 72-96 h. Late in the forecast period, Josephine or its remnants are expected to turn north-northeastward along the southern edge of the higher-latitude westerlies. The track guidance has not changed significantly since the previous advisory, and the new NHC forecast track is very similar to the previous forecast. Southwesterly to westerly shear should markedly increase after 12-18 h due mainly to upper-level troughing over the southwestern Atlantic. The new intensity forecast leaves open the possibility of a little strengthening during the next 12 h, followed by weakening due to the shear. The intensity forecast follows the previous forecast showing the system decaying to a remnant low by 120 h. However, an alternative scenario, supported by several of the global models, is that the cyclone decays to a tropical wave well before that time. Josephine should pass far enough to the northeast of the Leeward Islands over the weekend to prevent major impacts. However, interests in the area should continue to monitor its progress until the storm has passed north of that area. FORECAST POSITIONS AND MAX WINDS INIT 14/1500Z 16.1N 54.7W 35 KT 40 MPH 12H 15/0000Z 17.1N 56.7W 40 KT 45 MPH 24H 15/1200Z 18.4N 59.3W 40 KT 45 MPH 36H 16/0000Z 19.7N 61.8W 40 KT 45 MPH 48H 16/1200Z 20.9N 64.1W 35 KT 40 MPH 60H 17/0000Z 22.5N 66.0W 35 KT 40 MPH 72H 17/1200Z 24.0N 67.0W 30 KT 35 MPH 96H 18/1200Z 27.0N 67.5W 30 KT 35 MPH 120H 19/1200Z 30.6N 65.5W 25 KT 30 MPH...POST-TROP/REMNT LOW $$ Forecaster Beven

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Tropical Depression Ten-E Forecast Discussion Number 6

2020-08-14 16:33:00| National Hurricane Center (East Pacific)

Issued at 800 AM PDT Fri Aug 14 2020 000 WTPZ45 KNHC 141432 TCDEP5 Tropical Depression Ten-E Discussion Number 6 NWS National Hurricane Center Miami FL EP102020 800 AM PDT Fri Aug 14 2020 Since the last advisory, the depression has maintained a small ragged band of convection in its southwest quadrant. Intensity fixes from TAFB, SAB, and UW-CIMSS (both ADT and SATCON) do not indicate that the system has changed appreciably so the intensity remains 30 kt for this advisory. The intensity guidance is generally more bullish on the future of the depression than it has been previously. The COAMPS-TC and GFS now forecast strengthening to occur in a few days, and the latter of those models forms a symmetric CDO with an eye in simulated satellite imagery around day 5. In the short term, strong northeasterly shear should continue to limit the development potential of the cyclone, but upper-level winds could become less hostile in a few days. The main change to the NHC intensity forecast was to maintain the system as a tropical cyclone through day 5 and to show some minimal strengthening near the end of the period, though it is slightly below the intensity consensus. That said, there is perhaps equal probability that the system could become a remnant low before the environmental conditions improve, in which case no increase in the system's winds will likely occur. No significant changes were made to the NHC track forecast. The depression is moving west-southwestward near 5 kt, steered by a low- to mid-level ridge to its north. The global models indicate that the ridge will weaken in a day or two, allowing the system to gain a little latitude. Regardless of its exact heading, only a slow drift is expected through early next week. FORECAST POSITIONS AND MAX WINDS INIT 14/1500Z 13.6N 131.9W 30 KT 35 MPH 12H 15/0000Z 13.4N 132.3W 30 KT 35 MPH 24H 15/1200Z 13.2N 132.9W 30 KT 35 MPH 36H 16/0000Z 13.3N 133.2W 30 KT 35 MPH 48H 16/1200Z 13.6N 133.6W 30 KT 35 MPH 60H 17/0000Z 14.1N 134.1W 30 KT 35 MPH 72H 17/1200Z 14.5N 134.7W 30 KT 35 MPH 96H 18/1200Z 14.8N 135.5W 35 KT 40 MPH 120H 19/1200Z 14.8N 136.3W 35 KT 40 MPH $$ Forecaster Zelinsky

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