Tropical Cyclone Discussion

306
WTNT43 KNHC 300843
TCDAT3
 
Tropical Storm Hanna Discussion Number   8
NWS National Hurricane Center Miami FL       AL082026
900 AM GMT Wed Sep 30 2026
 
This morning's conventional satellite presentation consists of
a poorly organized, severely sheared tropical cyclone.  Although the
associated deep convection is more than 170 mi east of the surface
center, a 0318 UTC OSCAT-3 scatterometer pass indicated that the
cyclone is still producing a small area of tropical-storm-force
winds.  Based on this satellite-derived wind data, the initial
intensity is held at 35 kt.
 
Hanna should gradually weaken today due to increasing deep-layer
northwesterly shear, and continued dry air entrainment.  The
GFS/ECMWF simulated satellite/IR imagery prediction shows Hanna
quickly losing organized deep convection and becoming a
post-tropical cyclone by tonight and opening into a trough of
low pressure over the weekend.  The global models and the
statistical Decay-SHIPS intensity guidance are also indicating that
the remnants of Hanna could merge with a baroclinic system on
Friday.  No significant changes were made to the NHC intensity
forecast.
 
Hanna's initial motion is estimated to be east-southeastward, or
120/4 kt.  This general motion should continue this morning while
the cyclone remains in the low- to mid-level mid-latitude westerly
steering flow provided by a longwave trough moving over the
northeastern Atlantic.  By this evening, Hanna should turn
east-northeastward while the cyclone degenerates into a swirl of
low clouds and is steered by the low-level flow.  The official
forecast is adjusted to the right of the previous advisory and is
nudged toward the HFIP HCCA guidance.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  30/0900Z 33.5N  43.9W   35 KT  40 MPH
 12H  30/1800Z 33.9N  43.3W   30 KT  35 MPH...POST-TROP/REMNT LOW
 24H  01/0600Z 34.4N  41.7W   30 KT  35 MPH...POST-TROP/REMNT LOW
 36H  01/1800Z 35.2N  39.2W   30 KT  35 MPH...POST-TROP/REMNT LOW
 48H  02/0600Z 35.4N  36.7W   25 KT  30 MPH...POST-TROP/REMNT LOW
 60H  02/1800Z 35.6N  34.1W   25 KT  30 MPH...POST-TROP/REMNT LOW
 72H  03/0600Z 35.3N  32.1W   25 KT  30 MPH...POST-TROP/REMNT LOW
 96H  04/0600Z...DISSIPATED