000 WTPZ41 KNHC 280842 TCDEP1 TROPICAL DEPRESSION ONE-E DISCUSSION NUMBER 1 NWS NATIONAL HURRICANE CENTER MIAMI FL EP012015 300 AM MDT THU MAY 28 2015 Deep convection has become increasingly consolidated and organized in association with an area of low pressure located well to the southwest of the coast of Mexico. Enough convective banding has formed to yield Dvorak estimates of T2.0/30 kt from TAFB and T1.5/25 kt from SAB, and a 0459 UTC ASCAT-B pass showed maximum winds near 30 kt. The ASCAT data also showed that a center of circulation appeared sufficiently well defined, allowing the designation of the low as a 30-kt tropical depression at this time. The depression lies to the south of a mid-level ridge which extends from central Mexico west-southwestward over the eastern Pacific, and its initial motion is 295/13 kt. Global model fields show that the ridge should remain firmly in place, especially to the northwest of the depression, during the next several days. This should force the cyclone to slow down considerably and move north-northwestward from days 2 through 5. There is good agreement among the track models during the first 3 days of the forecast. By days 4 and 5, however, there is more uncertainty with the GFDL and HWRF models showing a northward motion while the GFS and ECMWF show a northwestward motion. The NHC track forecast currently lies closest to the GFS model and the TVCE multi-model consensus. Regardless of the exact track, the cyclone is expected to stay well to the southwest of Mexico during the entire forecast period. Relatively low shear and warmer-than-normal sea surface temperatures should support intensification during the next 3 days or so. Of the intensity guidance, the SHIPS model is the most aggressive, making the cyclone a hurricane by 36 hours with a peak intensity near 90 kt in 2-3 days. The official intensity forecast isn't quite that aggressive, but it does lie slightly above the ICON intensity consensus. Rapid intensification isn't out of the question, and in fact the RI guidance suggests that it may be likely during the next 24 hours. In light of that, some upward adjustment to the official forecast may be needed in subsequent advisories. Weakening should begin by day 4 once the cyclone reaches colder water. Note that beginning this year, Tropical Cyclone Public Advisories, Discussions, and Updates for the eastern North Pacific will now use different time zones depending on the cyclone's current location, as follows: Central Time: east of 106.0W Mountain Time: 106.0W to 114.9W Pacific Time: 115.0W westward FORECAST POSITIONS AND MAX WINDS INIT 28/0900Z 11.0N 110.4W 30 KT 35 MPH 12H 28/1800Z 11.7N 111.5W 40 KT 45 MPH 24H 29/0600Z 12.6N 112.8W 50 KT 60 MPH 36H 29/1800Z 13.4N 113.5W 60 KT 70 MPH 48H 30/0600Z 14.2N 114.0W 70 KT 80 MPH 72H 31/0600Z 16.0N 115.0W 80 KT 90 MPH 96H 01/0600Z 17.5N 116.0W 70 KT 80 MPH 120H 02/0600Z 19.0N 117.0W 60 KT 70 MPH $$ Forecaster Berg