je.st
news
Tropical Depression FOURTEEN-E Forecast Discussion Number 7
2015-09-02 10:34:10| National Hurricane Center (East Pacific)
Issued at 200 AM PDT WED SEP 02 2015 000 WTPZ44 KNHC 020834 TCDEP4 TROPICAL DEPRESSION FOURTEEN-E DISCUSSION NUMBER 7 NWS NATIONAL HURRICANE CENTER MIAMI FL EP142015 200 AM PDT WED SEP 02 2015 Deep convection has increased somewhat during the past few hours, but it is oriented linearly north to south, displaced to the east of the low-level center. Unfortunately ASCAT missed the circulation tonight, and Dvorak final-T numbers from SAB and TAFB were steady or decreased from six hours ago. Therefore, the cyclone is being maintained as a 30-kt depression. The depression is located just to the east of a sharp upper-level trough, which is producing about 15 kt of southwesterly shear over the cyclone. The trough is expected to weaken soon, which should allow the shear to decrease slightly during the next 36 hours. However, dry mid-level air is located just to the west of the depression, and the shear will likely not relax enough to prevent an asymmetric convective pattern. The new NHC intensity forecast continues to show the possibility of the depression reaching tropical storm strength during the next 36 hours, but the peak intensity is a little bit lower than in the previous advisory. An increase in shear after 36 hours should cause deep convection to become significantly displaced from the center, leading to the depression degenerating to a remnant low by day 3. Although the center has still been tough to pinpoint, the depression appears to have turned north-northwestward with an initial motion of 335/9 kt. A subtropical ridge over Mexico and a deep-layer trough west of the Baja California peninsula should steer the depression generally northward through day 3. Once it becomes a shallow remnant low, it will likely meander or drift westward in the low-level flow. There are considerable speed differences between the track models, presumably a result of how soon each depicts the cyclone becoming sheared. The updated NHC track forecast is again a little slower than the previous one and is close to the GFS-ECMWF model consensus. FORECAST POSITIONS AND MAX WINDS INIT 02/0900Z 15.2N 115.1W 30 KT 35 MPH 12H 02/1800Z 16.4N 115.5W 35 KT 40 MPH 24H 03/0600Z 17.8N 115.9W 35 KT 40 MPH 36H 03/1800Z 18.9N 115.8W 35 KT 40 MPH 48H 04/0600Z 20.0N 115.4W 30 KT 35 MPH 72H 05/0600Z 21.6N 115.0W 25 KT 30 MPH...POST-TROP/REMNT LOW 96H 06/0600Z 22.6N 115.6W 20 KT 25 MPH...POST-TROP/REMNT LOW 120H 07/0600Z...DISSIPATED $$ Forecaster Berg
Tags: number
discussion
tropical
depression
Category:Transportation and Logistics