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Tropical Storm BERTHA Forecast Discussion Number 22
2014-08-06 10:46:05| National Hurricane Center (Atlantic)
Issued at 500 AM AST WED AUG 06 2014 000 WTNT43 KNHC 060846 TCDAT3 TROPICAL STORM BERTHA DISCUSSION NUMBER 22 NWS NATIONAL HURRICANE CENTER MIAMI FL AL032014 500 AM AST WED AUG 06 2014 Deep convection continues to pulse downshear of the center of Bertha, as the tropical cyclone is situated in a favorable region for forced ascent in the equatorward entrance region of an upper- level jet streak. The initial intensity remains 45 kt based on the Dvorak classification from TAFB and an earlier ASCAT pass that showed some 40-45 kt winds east of the center. As Bertha becomes embedded in the jet, the vertical shear will increase in the next 12 to 24 hours. This should result in the low-level circulation decoupling from the convection while the cyclone becomes embedded in a baroclinic zone. Bertha should be post-tropical by 24 hours, and then gradually decay as an extratropical cyclone. Bertha is expected to be absorbed by day 5, although this could occur sooner. The latest satellite fixes indicate an initial motion of 055/24. Bertha is well embedded in deep-layer southwesterly flow ahead of a mid-latitude trough, and will continue moving northeastward over the north Atlantic for the next day or so before turning eastward by 72 hours. The new NHC track is largely an update of the previous one, and is close to guidance provided by the NOAA Ocean Prediction Center. FORECAST POSITIONS AND MAX WINDS INIT 06/0900Z 39.0N 65.4W 45 KT 50 MPH 12H 06/1800Z 40.8N 61.7W 45 KT 50 MPH 24H 07/0600Z 43.6N 55.7W 40 KT 45 MPH...POST-TROP/EXTRATROP 36H 07/1800Z 46.0N 49.9W 40 KT 45 MPH...POST-TROP/EXTRATROP 48H 08/0600Z 48.0N 44.0W 40 KT 45 MPH...POST-TROP/EXTRATROP 72H 09/0600Z 48.5N 28.0W 35 KT 40 MPH...POST-TROP/EXTRATROP 96H 10/0600Z 48.5N 12.5W 35 KT 40 MPH...POST-TROP/EXTRATROP 120H 11/0600Z...ABSORBED $$ Forecaster Brennan
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