je.st
news
Tropical Depression SIX-E Forecast Discussion Number 2
2015-07-12 22:51:17| National Hurricane Center (East Pacific)
Issued at 200 PM PDT SUN JUL 12 2015 000 WTPZ41 KNHC 122051 TCDEP1 TROPICAL DEPRESSION SIX-E DISCUSSION NUMBER 2 NWS NATIONAL HURRICANE CENTER MIAMI FL EP062015 200 PM PDT SUN JUL 12 2015 The convective structure of the tropical cyclone has improved somewhat today, with a band of deep convection wrapping around the south and southwestern portions of the circulation. Although Dvorak data T-numbers have increased to T2.5 from both agencies, a recent ASCAT pass suggests that the system is still below tropical storm strength. Environmental conditions consisting of warm water and low vertical wind shear should allow for strengthening during the next couple of days. The primary inhibiting factor appears to be some drier and more stable air to the north and northwest of the cyclone. The NHC intensity forecast is similar to the previous advisory and is in close agreement with the SHIPS guidance during the first 48 hours. After that time, increasing southerly shear, cooler waters, and a more stable airmass are expected to cause weakening. Visible satellite images indicate that the initial position of the cyclone is a little south of the previous estimate. As a result, the initial motion is a somewhat uncertain 300/6. The depression is expected to move on a general west-northwest to northwest heading during the next several days while it remains to the south of a narrow mid-level ridge. Near the end of the forecast period, the global models continue to show weakening of the steering flow over the far eastern Pacific as the large circulation of Dolores approaches from the east. This is likely to cause the cyclone's forward speed to decrease. The track guidance remains in agreement on this scenario, and the NHC forecast is close to the GFS ensemble mean, and just south of the model consensus. The new NHC track is a little south of the previous advisory due to the more southward initial position. FORECAST POSITIONS AND MAX WINDS INIT 12/2100Z 13.6N 125.8W 30 KT 35 MPH 12H 13/0600Z 14.5N 127.0W 35 KT 40 MPH 24H 13/1800Z 15.3N 128.2W 40 KT 45 MPH 36H 14/0600Z 15.9N 129.5W 45 KT 50 MPH 48H 14/1800Z 16.4N 130.9W 50 KT 60 MPH 72H 15/1800Z 17.0N 133.5W 45 KT 50 MPH 96H 16/1800Z 18.0N 135.5W 40 KT 45 MPH 120H 17/1800Z 18.3N 136.5W 35 KT 40 MPH $$ Forecaster Brown
Tags: number
discussion
tropical
depression
Category:Transportation and Logistics