000 WTPZ41 KNHC 110238 TCDEP1 Tropical Depression Adrian Discussion Number 6 NWS National Hurricane Center Miami FL EP012017 1000 PM CDT Wed May 10 2017 Strong southeasterly vertical wind shear has completely decoupled the mid-/upper-level circulation from the low-level circulation, with those two features now being separated by more than 250 nmi. Moreover, there has been no deep convection within 100 nmi of the exposed low-level circulation for more than 9 hours, and outflow boundaries have been noted moving southward and eastward toward the low-level circulation center over the past few hours. The associated stable air behind those boundaries will likely prevent regeneration of any central deep convection in the near term, resulting in Adrian becoming a remnant low by early Thursday. After 48 hours, the various dynamical and statistical models are in significant disagreement on possible regeneration. The GFS, UKMET, CMC, SHIPS, and LGEM models are indicating regeneration into a significant tropical cyclone by 48 hours and beyond, whereas the ECMWF, HWRF, and Navy COAMPS models show Adrian remaining a shallow remnant low for the next 5 days. Given that environmental conditions are expected to be favorable with SSTs greater than 30C, a moist mid-level environment, and fairly low shear, the official intensity forecast is a middle-of-the-road blend between these two extremes. However, complete dissipation of this system is a very distinct possibility some time during the forecast period. The initial motion estimate is 305/04 kt. Adrian is expected to move slowly west-northwestward to northwestward for the next 24 to 48 hours. The shallow system is forecast to turn more westward by 72 hours and beyond, possibly even stalling and making erratic motion due to the expected collapse of the steering currents as the deep-layer ridge over Mexico and the Gulf of Mexico breaks down. The new NHC track forecast is similar to the previous advisory, and lies a little south of the TVCN consensus model, closer to the ECMWF solution. FORECAST POSITIONS AND MAX WINDS INIT 11/0300Z 10.5N 93.1W 30 KT 35 MPH 12H 11/1200Z 11.1N 93.9W 30 KT 35 MPH...POST-TROP/REMNT LOW 24H 12/0000Z 11.7N 94.9W 25 KT 30 MPH...POST-TROP/REMNT LOW 36H 12/1200Z 12.1N 95.7W 25 KT 30 MPH...POST-TROP/REMNT LOW 48H 13/0000Z 12.4N 96.6W 30 KT 35 MPH 72H 14/0000Z 12.4N 97.0W 30 KT 35 MPH 96H 15/0000Z 12.4N 97.4W 35 KT 40 MPH 120H 16/0000Z 12.4N 97.7W 40 KT 45 MPH $$ Forecaster Stewart