je.st
news
Tropical Storm Omar Forecast Discussion Number 7
2020-09-02 10:39:53| National Hurricane Center (Atlantic)
Issued at 500 AM AST Wed Sep 02 2020 000 WTNT45 KNHC 020839 TCDAT5 Tropical Storm Omar Discussion Number 7 NWS National Hurricane Center Miami FL AL152020 500 AM AST Wed Sep 02 2020 UW-CIMSS analyses and SHIPS model diagnostics all indicate that Omar is being blasted by 40-50 kt of northwesterly shear, and yet a sizable area of deep convection has been hanging close to the low-level center for some time now. Based on last evening's ASCAT pass and the most recent satellite classifications, Omar's initial intensity remains 35 kt. Despite the shear magnitude, Omar could maintain tropical storm intensity for another 24 hours or so while the shear direction remains out of the northwest and the cyclone is over the warm Gulf Stream. During this period, the NHC forecast is close to the ICON intensity consensus and the HCCA aid. After 24 hours, Omar should begin moving over waters with lower ocean heat content, and the shear is forecast to veer more out of the north. Both of these factors are expected to cause weakening, with Omar likely to lose its deep convection and become a remnant low in about 2 days. Global models indicate that the remnant low should dissipate ahead of a cold front by day 4, which is now shown in the NHC forecast, although the ECMWF shows this happening a day earlier. Omar is moving toward the east-northeast (070/12 kt), embedded within the mid-latitude westerlies north of the subtropical ridge. This steering pattern is forecast to keep Omar on an east-northeastward or eastward path until it dissipates, but a breakdown of the zonal flow should cause the cyclone's forward speed to slow down gradually during the next 2-3 days. The updated NHC track forecast has been shifted southward a bit in the direction of the multi-model consensus aids and the GFS and ECMWF solutions, which both lie along the southern edge of the guidance envelope. FORECAST POSITIONS AND MAX WINDS INIT 02/0900Z 36.2N 68.7W 35 KT 40 MPH 12H 02/1800Z 36.6N 66.8W 35 KT 40 MPH 24H 03/0600Z 36.8N 64.0W 35 KT 40 MPH 36H 03/1800Z 36.6N 61.3W 30 KT 35 MPH 48H 04/0600Z 36.3N 59.2W 25 KT 30 MPH...POST-TROP/REMNT LOW 60H 04/1800Z 36.5N 57.6W 25 KT 30 MPH...POST-TROP/REMNT LOW 72H 05/0600Z 37.1N 56.0W 25 KT 30 MPH...POST-TROP/REMNT LOW 96H 06/0600Z...DISSIPATED $$ Forecaster Berg
Tags: number
discussion
storm
tropical
Category:Transportation and Logistics