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Tropical Storm HOWARD Forecast Discussion Number 11
2016-08-03 04:57:38| National Hurricane Center (East Pacific)
Issued at 800 PM PDT TUE AUG 02 2016 000 WTPZ44 KNHC 030257 TCDEP4 TROPICAL STORM HOWARD DISCUSSION NUMBER 11 NWS NATIONAL HURRICANE CENTER MIAMI FL EP092016 800 PM PDT TUE AUG 02 2016 Howard is still displaying some convection this evening, but the extent and organization of the convection is diminishing. Correspondingly, the Dvorak classifications are dropping and a blend of the TAFB, SAB, and CIMSS-ADT values indicate the intensity has dropped to around 40-45 kt. 45 kt is used as the initial intensity, though this may be generous given Howard's recent trends. The initial position of Howard has significant uncertainty, as there have been no microwave images available nor has the last-light visible imagery been very illuminating. The initial motion is assessed as 13 kt toward the west-northwest, as the system is primarily being steered by a mid-level ridge to its northeast. The track models are tightly clustered and suggest a gradual turn toward the west at about the same forward speed during the next few days. The NHC track forecast is nearly the same as that from the previous advisory and is based upon the TVCN track model consensus. While the vertical shear should remain relatively low over Howard during the next day and a half, the SSTs that Howard will traverse should get quite cool and the atmosphere dry and stable. At about two days, the SSTs become lukewarm but the shear becomes prohibitive for intensification. Thus it is expected that Howard will gradually weaken, and in about two days lose its deep convection and become a post-tropical cyclone. The NHC intensity forecast is based upon the LGEM and SHIPS statistical/dynamical methods, as the three dynamical hurricane models - HWRF, GFDL, and COAMPS - all unrealistically re-intensify Howard between days three and five. This official forecast calls for slightly weaker intensities than those indicated in the previous advisory. FORECAST POSITIONS AND MAX WINDS INIT 03/0300Z 20.1N 131.3W 45 KT 50 MPH 12H 03/1200Z 20.9N 133.3W 40 KT 45 MPH 24H 04/0000Z 21.7N 136.1W 40 KT 45 MPH 36H 04/1200Z 22.3N 138.9W 35 KT 40 MPH 48H 05/0000Z 22.6N 141.8W 35 KT 40 MPH...POST-TROPICAL 72H 06/0000Z 23.0N 147.5W 30 KT 35 MPH...POST-TROP/REMNT LOW 96H 07/0000Z 23.0N 152.5W 25 KT 30 MPH...POST-TROP/REMNT LOW 120H 08/0000Z 23.0N 157.5W 25 KT 30 MPH...POST-TROP/REMNT LOW $$ Forecaster Landsea
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