je.st
news
Subtropical Storm Melissa Forecast Discussion Number 3
2019-10-12 04:34:43| National Hurricane Center (Atlantic)
Issued at 1100 PM AST Fri Oct 11 2019 000 WTNT44 KNHC 120234 TCDAT4 Subtropical Storm Melissa Discussion Number 3 NWS National Hurricane Center Miami FL AL142019 1100 PM AST Fri Oct 11 2019 Although Melissa's convection hasn't been very deep for much of the day, there has been a slight cooling of cloud tops during the past few hours. This could possibly be due to the system's center now moving over the core of the Gulf Stream current, where water temperatures are around 27 degrees Celsius. There has also been sporadic lightning strikes observed within the convection to the north of the center. Despite this, the latest Hebert-Poteat subtropical classification from TAFB is ST2.5/35 kt, and a UW-CIMSS SATCON estimate from a few hours ago was 44 kt. Based on these data, Melissa's winds are lowered to 45 kt. Melissa is moving a little faster and now toward the southeast, or 125/6 kt. Although Melissa and its parent upper-level low are cut off from the mid-latitude westerlies, a ridge currently located over the Appalachian Mountains is expected to flatten on Saturday, causing westerly flow to become established and force Melissa out to sea. The cyclone is forecast to accelerate eastward starting on Saturday and continuing into early next week. No significant changes were made to the NHC track forecast on this cycle. Melissa's journey across the warm Gulf Stream waters will be short lived, only lasting for about 12 hours, and upper-level westerly winds will be increasing over the system significantly on Saturday. Therefore, gradual weakening is anticipated, with the NHC intensity forecast more or less mirroring the guidance provided by the GFS and ECMWF global models. Melissa is expected to degenerate into a remnant low by 36 hours, if not sooner. The remnant low is likely to be absorbed within a frontal zone over the north Atlantic by day 4. Ongoing hazards from wind and coastal flooding will continue to be covered by non-tropical products from local National Weather Service forecast offices. Gale-force winds that extend from the Gulf of Maine and Nova Scotia eastward over the Atlantic are not included in the wind radii, since they are associated with a frontal boundary. Key Messages: 1. Melissa is expected to slowly weaken and move away from the U.S. east coast overnight and on Saturday, resulting in a gradual decrease in wind and coastal flooding impacts. 2. Minor to moderate coastal flooding is still expected along portions of the U.S. Mid-Atlantic and southeastern New England coasts on Saturday around times of high tide. For more information, see products issued by local National Weather Service forecast offices at weather.gov. FORECAST POSITIONS AND MAX WINDS INIT 12/0300Z 37.7N 68.8W 45 KT 50 MPH 12H 12/1200Z 37.8N 67.7W 40 KT 45 MPH 24H 13/0000Z 38.1N 65.2W 35 KT 40 MPH 36H 13/1200Z 38.5N 62.1W 30 KT 35 MPH...POST-TROP/REMNT LOW 48H 14/0000Z 39.0N 58.6W 25 KT 30 MPH...POST-TROP/REMNT LOW 72H 15/0000Z 40.4N 50.8W 25 KT 30 MPH...POST-TROP/REMNT LOW 96H 16/0000Z...ABSORBED WITHIN A FRONTAL ZONE $$ Forecaster Berg
Tags: number
discussion
storm
forecast
Category:Transportation and Logistics