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Tropical Depression FOUR-E Forecast Discussion Number 5
2014-06-29 22:40:54| National Hurricane Center (East Pacific)
Issued at 200 PM PDT SUN JUN 29 2014 000 WTPZ44 KNHC 292040 TCDEP4 TROPICAL DEPRESSION FOUR-E DISCUSSION NUMBER 5 NWS NATIONAL HURRICANE CENTER MIAMI FL EP042014 200 PM PDT SUN JUN 29 2014 Satellite images suggest that the depression's cloud pattern has not become better organized since this morning. Deep convection near the center has decreased, while convection remains concentrated in a long band over the western semicircle of the circulation. A partial ASCAT overpass at 1722 UTC continues to indicate a large and sprawling cyclonic envelope associated with the depression, with the strongest winds well removed from the center of circulation. Dvorak intensity estimates are a 2.5 and 2.0 from TAFB and SAB, respectively, at 1800 UTC. Given the lack of change in the system's organization, the initial intensity estimate is maintained at 30 kt for this advisory. The center is still not obvious, even in visible satellite imagery, and thus the initial motion estimate, or 295/14, is as uncertain as it was previously. The cyclone should continue to move at a fast clip on the south side of a strong subtropical ridge. This ridge is forecast to weaken and shift westward during the next couple of days when a mid- to upper-level shortwave trough moves into the California coast. This should cause a notable reduction in the forward speed of the cyclone during this time, with the track becoming more westerly after that once the storm becomes more shallow in nature. The NHC track forecast remains on the left side of the guidance envelope, slightly to the left of and slower than the previous one through 36 hours. The forecast track is adjusted to the right and is slower beyond 36 hours but is not as far right as the ECMWF, GFS, and multi-model consensus TVCE. Low shear and warm waters along the depression's track should favor intensification for another day or possibly two, but the large size and slow evolution of inner core suggests that any strengthening will only be gradual. Cooler waters and a drier and more stable atmosphere should bring any intensification to a halt in about two days, with slow but steady weakening after that time in the absence of any significant shear. The thermodynamics should become increasingly unfavorable late in the forecast period, and remnant low status is now forecast on day 5. The NHC intensity forecast is a bit lower than the previous one and close to the multi-model consensus IVCN through 72 hours but a bit lower after that time. FORECAST POSITIONS AND MAX WINDS INIT 29/2100Z 16.5N 111.9W 30 KT 35 MPH 12H 30/0600Z 17.0N 113.6W 35 KT 40 MPH 24H 30/1800Z 17.6N 115.0W 45 KT 50 MPH 36H 01/0600Z 18.3N 116.1W 50 KT 60 MPH 48H 01/1800Z 18.7N 116.9W 50 KT 60 MPH 72H 02/1800Z 18.8N 117.7W 40 KT 45 MPH 96H 03/1800Z 18.9N 118.7W 30 KT 35 MPH 120H 04/1800Z 18.8N 120.5W 25 KT 30 MPH...POST-TROP/REMNT LOW $$ Forecaster Kimberlain
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