je.st
news
Tropical Storm Miriam Forecast Discussion Number 2
2018-08-26 16:38:56| National Hurricane Center (East Pacific)
Issued at 800 AM PDT Sun Aug 26 2018 565 WTPZ45 KNHC 261438 TCDEP5 Tropical Storm Miriam Discussion Number 2 NWS National Hurricane Center Miami FL EP152018 800 AM PDT Sun Aug 26 2018 Deep convection associated with the tropical cyclone has continued to become better organized this morning, with a significant increase in banding noted in conventional satellite imagery. An earlier AMSR2 microwave overpass also revealed the increase in banding, but the low-level center was located near the northeastern portion of the main convective mass. A Dvorak satellite intensity estimate of T2.5 (35 k) was the basis for the 1200 UTC synoptic intensity, but with the continued increase in organization, the initial wind speed for this advisory has been set to 40 kt. Miriam is moving westward or 275/11 kt. The tropical storm should remain on a general westward heading during the next few days while it remains to the south of a deep-layer ridge. The orientation of the ridge may shift more west-southwestward within the next day or so, which could steer the tropical storm on a track slightly south of due west. The bulk of the dynamical model guidance has shifted southward, so the NHC forecast track has been adjusted accordingly through the first 3 days. After that time, a weakness in the subtropical ridge between 140W-145W longitude is expected to cause Miriam to turn northwestward, then north-northwestward by the end of the forecast period. The latter portion of the official forecast is similar to the previous advisory and is in best agreement with the HFIP corrected consensus model. The environment ahead of Miriam is expected to remain favorable for strengthening. The tropical storm will be traversing SSTs of 27-28C and within low vertical wind shear conditions. The NHC intensity forecast calls for steady intensification during the next few days and is at the upper-end of the intensity guidance. Although the various rapid intensification prediction techniques are not particularly bullish, perhaps due to the low initial intensity of the cyclone, it would not be surprising if the tropical storm went through a period of rapid intensification within the next couple of days. The NHC intensity forecast is closest to the more aggressive HWRF and HMON dynamical models. FORECAST POSITIONS AND MAX WINDS INIT 26/1500Z 13.2N 125.3W 40 KT 45 MPH 12H 27/0000Z 13.3N 127.1W 50 KT 60 MPH 24H 27/1200Z 13.5N 129.4W 60 KT 70 MPH 36H 28/0000Z 13.5N 131.5W 70 KT 80 MPH 48H 28/1200Z 13.5N 133.6W 80 KT 90 MPH 72H 29/1200Z 13.5N 137.6W 85 KT 100 MPH 96H 30/1200Z 14.9N 140.5W 90 KT 105 MPH 120H 31/1200Z 18.5N 142.0W 85 KT 100 MPH $$ Forecaster Brown
Tags: number
discussion
storm
tropical
Category:Transportation and Logistics