je.st
news
Hurricane Delta Forecast Discussion Number 15
2020-10-08 10:33:07| National Hurricane Center (Atlantic)
Issued at 400 AM CDT Thu Oct 08 2020 000 WTNT41 KNHC 080832 TCDAT1 Hurricane Delta Discussion Number 15 NWS National Hurricane Center Miami FL AL262020 400 AM CDT Thu Oct 08 2020 Satellite images indicate that Delta remains a well organized hurricane with a central dense overcast feature and curved bands beyond that. There is still no indication of an eye, however, in geostationary satellite images. The Air Force Hurricane Hunters were in Delta a few hours ago and toward the end of that mission, they reported maximum flight-level winds of 102 kt and SFMR winds of 77 kt. Based on a blend of this data, the initial intensity was increased to 85 kt at 0600 UTC. Since the cyclone appears to be generally steady in strength since that time, the wind speed is held at that value. Both the NOAA and Air Force Hurricane Hunters will be investigating Delta later today, and that data will help us assess its strength and structure. The track forecast reasoning is unchanged. Delta is currently moving northwestward at 13 kt on the southwestern periphery of an Atlantic subtropical ridge. The western portion of the ridge is expected to weaken later today as a trough moves eastward across the south-central United States. This change in the steering pattern should cause Delta to turn northward by late tonight and north-northeastward by Friday night. This motion should take the core of the hurricane to the Louisiana coast in a little more than 36 hours (sometime Friday afternoon or evening). After landfall, a turn to the northeast is forecast as a larger trough approaches Delta from the west. The models are in very good agreement, and the NHC track forecast is just an update of the previous one. Delta is expected to continue gradually strengthening during the next 24 hours while it remains over warm deep waters and in an environment of low wind shear and a high amount of moisture. Based on these favorable environmental conditions and the trend in the models, Delta is forecast to regain major hurricane status by tonight. Just prior to making landfall, the cyclone is forecast to level off in strength or weaken slightly as it moves over the cooler shelf waters and into somewhat less favorable atmospheric conditions. Rapid weakening is forecast after Delta moves inland. The intensity models are in fairly good agreement, and the NHC intensity forecast lies near the middle of the guidance envelope. It should be noted that the NHC 1-2 day intensity forecasts are subject to errors of around 1 Saffir-Simpson category. The aircraft and fairly recent scatterometer data indicate that Delta is gradually growing in size. This trend is expected to continue as Delta approaches the Louisiana coast. The NHC wind radii forecast follows a consensus of the global and hurricane regional models. Key Messages: 1. Delta is expected to grow in size as it approaches the northern Gulf Coast, where life-threatening storm surge and dangerous hurricane-force winds are likely beginning Friday, particularly for portions of the Louisiana coast. Storm Surge and Hurricane Warnings are in effect, and residents in these areas should follow advice given by local officials and rush preparedness actions to completion. 2. Significant flash, urban, small stream and minor to isolated moderate river flooding is likely Friday and Saturday from portions of the central Gulf Coast into portions of the Lower Mississippi Valley. As Delta moves farther inland, heavy rainfall is expected in the Ohio Valley and Mid-Atlantic this weekend. FORECAST POSITIONS AND MAX WINDS INIT 08/0900Z 23.4N 91.8W 85 KT 100 MPH 12H 08/1800Z 24.6N 93.0W 95 KT 110 MPH 24H 09/0600Z 26.4N 93.7W 100 KT 115 MPH 36H 09/1800Z 28.8N 93.4W 90 KT 105 MPH 48H 10/0600Z 31.3N 92.4W 55 KT 65 MPH...INLAND 60H 10/1800Z 33.3N 90.9W 30 KT 35 MPH...INLAND 72H 11/0600Z 34.6N 89.0W 20 KT 25 MPH...POST-TROP/REMNT LOW 96H 12/0600Z...DISSIPATED $$ Forecaster Cangialosi
Tags: number
discussion
delta
forecast
Category:Transportation and Logistics
Latest from this category |
All news |
||||||||||||||||||
|
|||||||||||||||||||