|
Show Selection: |
| #1009298 (Received by flhurricane at: 4:51 PM 23.Jul.2020) TCDAT3 Tropical Depression Eight Discussion Number 4 NWS National Hurricane Center Miami FL AL082020 400 PM CDT Thu Jul 23 2020 Satellite imagery indicates that the depression continues to become better organized, with the center near the eastern edge of a large and broadly curved convective area, with a second curved band to the east. Several subjective and objective satellite intensity estimates have increased to 35 kt since the last advisory. However, surface observations, scatterometer data, and data from an earlier Air Force Reserve Hurricane Hunter mission show a large area of 25-30 kt winds south and east of the center, and no 35-kt winds to justify an upgrade at this time. Thus, the initial intensity remains 30 kt. A NOAA Hurricane Hunter aircraft is scheduled to investigate the depression this evening, and the current expectation is that they will find it is a tropical storm. The center meandered a bit today, possibly due to reformation. However, the system now seems to have resumed a west-northwestward motion of 285/7 kt. A mid-level ridge over the central United States is the predominant steering influence, and the global models forecast this ridge to build somewhat during the next several days. This should cause the depression to turn westward by 36-48 h and south of west after about 60 h. The track guidance remains in good agreement with that scenario, although there has been a slight southward shift in the guidance envelope and the consensus models. The new NHC forecast track is also shifted a little southward and has the center making landfall along the Texas coast in about 48 h. The depression is in an environment of light shear with good anticyclonic outflow, and it will be over warm sea surface temperatures until landfall. This should allow steady strengthening. The new NHC intensity forecast has been increased to show a peak intensity of 50 kt just before landfall, followed by steady weakening and eventually dissipation after landfall. The new intensity forecast is close to the intensity consensus. The aircraft and scatterometer data show that the strongest winds in the cyclone are currently occurring about 70-90 n mi from the center. This has caused the forecast wind radii to be expanded, and as a result a Tropical Storm Warning is needed for portions of the Texas coast. Key Messages 1. The depression is expected to strengthen and it is likely to bring tropical-storm-force winds to portions of the Texas coast, where a tropical storm warning has been issued. 2. The tropical cyclone is expected to produce heavy rains across portions of Louisiana, southern Texas, and northern Mexico. These rains could result in flash flooding and isolated minor-to-moderate river flooding. FORECAST POSITIONS AND MAX WINDS INIT 23/2100Z 26.1N 90.7W 30 KT 35 MPH 12H 24/0600Z 26.5N 91.9W 35 KT 40 MPH 24H 24/1800Z 27.1N 93.6W 45 KT 50 MPH 36H 25/0600Z 27.5N 95.3W 50 KT 60 MPH 48H 25/1800Z 27.6N 97.0W 50 KT 60 MPH 60H 26/0600Z 27.5N 98.5W 40 KT 45 MPH...INLAND 72H 26/1800Z 27.3N 100.0W 30 KT 35 MPH...INLAND 96H 27/1800Z 27.0N 102.0W 20 KT 25 MPH...POST-TROP/INLAND 120H 28/1800Z...DISSIPATED $$ Forecaster Beven |
