Home discussion
 

Keywords :   


Tag: discussion

Subtropical Storm Ernesto Forecast Discussion Number 4

2018-08-16 04:34:08| National Hurricane Center (Atlantic)

Issued at 1100 PM AST Wed Aug 15 2018 844 WTNT45 KNHC 160234 TCDAT5 Subtropical Storm Ernesto Discussion Number 4 NWS National Hurricane Center Miami FL AL052018 1100 PM AST Wed Aug 15 2018 Although inner-core convection has increased since the previous advisory, outer banding features have become more fragmented and the overall cloud pattern has become elongated north-to-south. There are also no signs of any upper-level anticyclonic outflow, an indication that Ernesto is still a subtropical cyclone. The initial intensity is being maintained at 35 kt based on a 2328Z ASCAT pass that showed peak winds of 32 kt in the southeastern quadrant, along with a radius of maximum winds of 70-80 nmi. This intensity is consistent with a ST2.5/35 kt classification from TAFB. The initial motion is now north-northeastward or 025/09 kt. Ernesto has rounded the subtropical ridge axis to its south, and the cyclone should gradually get caught up in the mid-latitude westerlies and turn northeastward during the next 12 hours or so. A northeastward motion along with a steadily increasing forward speed is expected through Friday. The track guidance is tightly packed around the previous advisory track, so the new NHC forecast track is essentially just an extension of the previous advisory, and lies near the track consensus models HCCA and TVCN. On the forecast track, Ernesto is expected to approach Ireland as an extratropical gale area on Saturday. Ernesto is expected to remain over sea-surface temperatures (SST) of 25 deg C or warmer for the next 18-24 hours, along with low vertical shear conditions of less than 10 kt. These conditions should allow for some slight strengthening during that short time window. By 36 hours, Ernesto is forecast to be moving over SSTs of 20 deg C and colder and into a more stable airmass, resulting in a degeneration of the inner-core convection. As a result, Ernesto is expected to become a post-tropical cyclone by 36 hours, and become an extratropical gale area after merging with a frontal zone near Ireland and the United Kingdom in about 3 days. FORECAST POSITIONS AND MAX WINDS INIT 16/0300Z 39.7N 45.1W 35 KT 40 MPH 12H 16/1200Z 41.3N 43.4W 40 KT 45 MPH 24H 17/0000Z 43.7N 40.0W 40 KT 45 MPH 36H 17/1200Z 46.3N 34.9W 40 KT 45 MPH...POST-TROPICAL 48H 18/0000Z 49.0N 27.9W 40 KT 45 MPH...POST-TROP/EXTRATROP 72H 19/0000Z 54.0N 12.1W 40 KT 45 MPH...POST-TROP/EXTRATROP 96H 20/0000Z...DISSIPATED $$ Forecaster Stewart

Tags: number discussion storm forecast

 

Tropical Storm Lane Forecast Discussion Number 5

2018-08-16 04:33:43| National Hurricane Center (East Pacific)

Issued at 800 PM PDT Wed Aug 15 2018 231 WTPZ44 KNHC 160233 TCDEP4 Tropical Storm Lane Discussion Number 5 NWS National Hurricane Center Miami FL EP142018 800 PM PDT Wed Aug 15 2018 Overall, Lane's cloud pattern has become a little better organized this evening. Modest east-northeasterly shear, however, along with some drier air, appears to be undercutting the diffluent outflow above 300 mb and is impinging the north through northeast portion of the cyclone. An outer deep convective curved band, on the other hand, is now developing over most of the eastern half of the system. The surface center is also located a bit further in the northern edge of an expanding, colder, central dense overcast. The initial intensity is increased to 45 kt, and is based on a compromise of the TAFB and SAB subjective Dvorak satellite intensity estimates (T3.0), and a 2205 UTC SATCON analysis (51 kt). Little change has been made to the previous intensity forecast, and it still shows a rapid increase of nearly 55 kt in 48 hours based on the Deterministic to Probabilistic Statistical Rapid Intensification Index (DTOPS) which indicates a 67 percent chance of RI occuring during this particular period. The NHC forecast is weighed heavily on a blend of the COAMPS-TC and the HFIP Corrected Consensus Approach model (HCCA), and indicates Lane intensifying into a category 3 hurricane in 3 days. Lane's motion is estimated to be westward, or 265/11 kt, a little to the left of due west, and is being steered by a broad mid-level ridge to its north-northwest. The large-scale models continue to show the ridge weakening in 2 days in response to a southwestward and westward retrograding cut-off mid-level low currently located southwest of the Baja California coast. At that time, the cyclone should gradually turn west-northwestward and continue in this general direction through the remaining period of the forecast. The official forecast is very close to the previous one, with only minor along-track adjustments, and sides with the HCCA and TVCN consensus models. FORECAST POSITIONS AND MAX WINDS INIT 16/0300Z 10.4N 125.6W 45 KT 50 MPH 12H 16/1200Z 10.4N 127.4W 60 KT 70 MPH 24H 17/0000Z 10.7N 129.8W 75 KT 85 MPH 36H 17/1200Z 11.1N 132.5W 85 KT 100 MPH 48H 18/0000Z 11.6N 135.2W 95 KT 110 MPH 72H 19/0000Z 12.9N 140.6W 105 KT 120 MPH 96H 20/0000Z 14.3N 145.4W 110 KT 125 MPH 120H 21/0000Z 15.2N 149.3W 105 KT 120 MPH $$ Forecaster Roberts

Tags: number discussion lane storm

 
 

Subtropical Storm Ernesto Forecast Discussion Number 3

2018-08-15 22:35:39| National Hurricane Center (Atlantic)

Issued at 500 PM AST Wed Aug 15 2018 320 WTNT45 KNHC 152035 TCDAT5 Subtropical Storm Ernesto Discussion Number 3 NWS National Hurricane Center Miami FL AL052018 500 PM AST Wed Aug 15 2018 Recent visible satellite imagery has shown a slight increase in convection near and to the east of the center of Ernesto this afternoon, but there has been little change in the overall organization of the subtropical storm. The satellite intensity estimate from TAFB remains an ST2.5, so the initial wind speed remains 35 kt for this advisory. Ernesto is forecast to remain over marginally warm SSTs and in a low wind shear environment during the next 12-24 hours, and some modest strengthening is anticipated. After that time, the cyclone will be moving over SSTs below 20C and into an area of increasing vertical wind shear. As a result, Ernesto is forecast to become a post-tropical cyclone in about 36 hours, and merge with a frontal zone near Ireland and the United Kingdom in 3 to 4 days. Ernesto is moving northward or 005/8 kt. The cyclone should turn north-northeastward tonight ahead of a mid-level trough that is located off the coast of the eastern United States. Ernesto is forecast to become embedded within the mid-latitude westerlies by late Thursday and it is expected to accelerate northeastward at that time. The track guidance remains in good agreement, and the NHC forecast is again near the center of the guidance envelope. FORECAST POSITIONS AND MAX WINDS INIT 15/2100Z 39.0N 45.7W 35 KT 40 MPH 12H 16/0600Z 40.4N 44.6W 40 KT 45 MPH 24H 16/1800Z 42.6N 42.1W 45 KT 50 MPH 36H 17/0600Z 45.1N 37.9W 45 KT 50 MPH...POST-TROPICAL 48H 17/1800Z 48.0N 31.8W 45 KT 50 MPH...POST-TROPICAL 72H 18/1800Z 53.0N 15.8W 40 KT 45 MPH...POST-TROP/EXTRATROP 96H 19/1800Z...MERGED WITH FRONTAL ZONE $$ Forecaster Brown

Tags: number discussion storm forecast

 

Tropical Storm Lane Forecast Discussion Number 4

2018-08-15 22:34:38| National Hurricane Center (East Pacific)

Issued at 200 PM PDT Wed Aug 15 2018 592 WTPZ44 KNHC 152034 TCDEP4 Tropical Storm Lane Discussion Number 4 NWS National Hurricane Center Miami FL EP142018 200 PM PDT Wed Aug 15 2018 Satellite images indicate that Lane is strengthening. The central dense overcast continues to grow, with a large banding feature in the western semicircle and expanding outflow in most quadrants. ASCAT data recently showed maximum winds of about 40 kt, so that will be the initial wind speed, which is also near a blend of the latest Dvorak estimates from TAFB and SAB. While the latest microwave data indicate that the inner core of Lane remains loosely organized, the large-scale environment appears to be favorable for intensification. Low shear, warm waters of 27.5-28C, and moderate levels of mid-level moisture all support strengthening at a higher rate than climatology. However, since the inner core is not well established yet, the intensity forecast will be held just below rapid strengthening (30 kt in 24 h) for day 1. There is still a strong signal for that threshold to be met in the day 2-3 period from the DTOPS rapid intensification index, so the forecast will remain for a major hurricane to form during that time. This forecast is close to a blend of the latest NOAA-HCCA and FSSE corrected consensus models. The storm continues to move just south of due west, now at about 11 kt. The synoptic pattern is well established with a subtropical ridge expected to only slightly weaken in the medium-range period, causing a slight west-northwestward turn in the central Pacific. While the overall spread has increased in the 1200 UTC guidance, the latest model consensus has barely budged since the previous advisory, although it does fit the recent westward trend. The latest official track forecast is again adjusted in that direction, close to the eastern Pacific track model consensus TVCE. FORECAST POSITIONS AND MAX WINDS INIT 15/2100Z 10.6N 124.5W 40 KT 45 MPH 12H 16/0600Z 10.5N 126.2W 50 KT 60 MPH 24H 16/1800Z 10.7N 128.4W 65 KT 75 MPH 36H 17/0600Z 11.1N 130.9W 80 KT 90 MPH 48H 17/1800Z 11.6N 133.6W 95 KT 110 MPH 72H 18/1800Z 12.6N 138.7W 105 KT 120 MPH 96H 19/1800Z 14.0N 143.6W 110 KT 125 MPH 120H 20/1800Z 15.2N 148.2W 105 KT 120 MPH $$ Forecaster Blake

Tags: number discussion lane storm

 

Board Discussion Guide: Filtration

2018-08-15 22:13:57| PortlandOnline

PDF Document, 205kbCategory: August 16, 2018 Materials

Tags: board guide discussion filtration

 

Sites : [552] [553] [554] [555] [556] [557] [558] [559] [560] [561] [562] [563] [564] [565] [566] [567] [568] [569] [570] [571] next »