Atlantic Basin Tropical Cyclones

Hurricane Danielle Forecast Discussion


000
WTNT45 KNHC 070233
TCDAT5

Hurricane Danielle Discussion Number  24
NWS National Hurricane Center Miami FL       AL052022
300 AM GMT Wed Sep 07 2022

This morning's conventional satellite presentation indicates
little change in Danielle's cloud pattern since yesterday morning.
However, a recent SSMI/S microwave image shows a subtle vertical
tilt toward the east.  The initial intensity is held at 65 kt for 
this advisory and is based on a blend of the subjective and AiDT 
objective satellite intensity estimates and an earlier STAR SAR/S1 
surface wind retrieval that indicated winds of 70 kt.  

Danielle should remain over marginally warm waters for the next 
12-18 hours. Subsequently, little change in strength is expected 
during that time.  By early Thursday, Danielle will move over a 
sharp surface temperature gradient of 22C or less.  This negative 
oceanic contribution, combined with the loss of dynamic forcing 
after the cyclone merges with the approaching baroclinic system, 
should induce a slow weakening trend through the end of the period.

Danielle's initial motion is estimated to be east-northeastward, or
060/11 kt.  There is no significant change to the NHC forecast
philosophy.  Danielle should continue accelerating in response to a 
vigorous baroclinic system approaching from the northwest Atlantic 
east of the Newfoundland coast.  Danielle is forecast to interact 
with the system mentioned above late Thursday night.  On Friday, the 
two systems are predicted to merge and become a larger and strong 
extratropical low with asymmetric deep warm core characteristics 
typical of warm seclusions.  Over the weekend, the large 
post-tropical low is expected to turn east-southeastward and 
maintain this general motion through early next week.

Danielle is producing a vast area of very rough seas over the
central-north Atlantic. More information can be found in the
High Seas Forecasts issued by the Ocean Prediction Center under
AWIPS header NFDHSFAT1, WMO header FZNT01 KWBC, and online at
ocean.weather.gov/shtml/NFDHSFAT1.php.
The UK Met Office also has information in High Seas Forecasts for
the west Central and east Central sections issued under WMO header
FQNT21 EGRR and on the web at
metoffice.gov.uk/weather/specialist-forecasts/coast-and-sea/high-
seas-forecast


FORECAST POSITIONS AND MAX WINDS

INIT  07/0300Z 42.7N  39.3W   65 KT  75 MPH
 12H  07/1200Z 43.6N  37.4W   65 KT  75 MPH
 24H  08/0000Z 45.4N  34.5W   60 KT  70 MPH
 36H  08/1200Z 47.6N  32.6W   55 KT  65 MPH...POST-TROP/EXTRATROP
 48H  09/0000Z 50.0N  32.7W   55 KT  65 MPH...POST-TROP/EXTRATROP
 60H  09/1200Z 50.9N  34.7W   50 KT  60 MPH...POST-TROP/EXTRATROP
 72H  10/0000Z 48.9N  34.9W   45 KT  50 MPH...POST-TROP/EXTRATROP
 96H  11/0000Z 45.3N  26.6W   40 KT  45 MPH...POST-TROP/EXTRATROP
120H  12/0000Z 43.1N  18.1W   35 KT  40 MPH...POST-TROP/EXTRATROP

$$
Forecaster Roberts



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