000 WTPZ42 KNHC 261451 TCDEP2 Tropical Storm Frank Discussion Number 2 NWS National Hurricane Center Miami FL EP072022 1000 AM CDT Tue Jul 26 2022 Satellite imagery this morning depicts a sheared bursting pattern associated with the tropical cyclone. An overnight convective burst obscured the low-level circulation center, but first-light visible imagery now shows the vortex mostly exposed east of the colder convective cloud tops. This structure can also be seen from the last couple SSMIS microwave passes near the center and is characteristic of environmental vertical wind shear (VWS) diagnosed between 15-20 knots from the northeast. Subjective Dvorak intensity estimates from TAFB and SAB were T2.5/35-kt and T2.0/30-kt respectively, while the latest UW-CIMSS ADT estimate was at T2.5/35-kt. The initial intensity has been raised to 35-kt this advisory, upgrading the tropical depression to tropical storm Frank. Northeasterly VWS between 15-20 kt is expected to continue over the next 48 hours, and will likely limit significant intensification in the short-term as the shear promotes misalignment between the low-level and mid-level centers. The latest intensity forecast only shows slow intensification in the short-term. Afterwards, this shear is expected to decrease, while the storm will remain over warm sea-surface temperatures near 29C through 96 hours. However, the current shear may also help broaden Frank's wind field as convection is favored outside of the radius of maximum wind, as suggested by the latest ECMWF run. These structural changes could limit more robust intensification later in the forecast despite the more favorable environment. For now, the latest NHC forecast still peaks Frank as a category 1 hurricane towards end of the forecast period. This forecast is on the lower end of the intensity guidance envelope, close to the LGEM model, and is somewhat lower than the consensus aids HCCA and IVCN. The tropical storm is moving generally westward at 280/9-kt. The track guidance is in fairly good agreement that this motion and heading will continue as a mid-level ridge extends westward to the north of Frank over the next 2-3 days. Towards the end of the forecast, the ridge overhead will begin to gradually weaken, and will likely allow a larger Frank to begin gaining more latitude. One complicating factor in the track forecast is the possibility of some weak binary interaction with another low-level circulation located to Frank's northwest, where the net interaction may help impart a bit more northerly heading to Frank's track between 72-96 hours. For now, the track forecast continues to favor a blend of the GFS and ECMWF forecast (GFEX) and is quite close to the previous forecast track. FORECAST POSITIONS AND MAX WINDS INIT 26/1500Z 11.6N 102.4W 35 KT 40 MPH 12H 27/0000Z 11.9N 104.1W 40 KT 45 MPH 24H 27/1200Z 12.1N 105.9W 40 KT 45 MPH 36H 28/0000Z 12.2N 107.6W 45 KT 50 MPH 48H 28/1200Z 12.6N 109.5W 45 KT 50 MPH 60H 29/0000Z 12.9N 111.3W 50 KT 60 MPH 72H 29/1200Z 13.6N 113.1W 65 KT 75 MPH 96H 30/1200Z 15.0N 116.5W 80 KT 90 MPH 120H 31/1200Z 17.5N 119.5W 80 KT 90 MPH $$ Forecaster Papin