Eastern Pacific Basin Tropical Cyclones

Hurricane Darby Forecast Discussion


590 
WTPZ45 KNHC 110237
TCDEP5

Hurricane Darby Discussion Number   6
NWS National Hurricane Center Miami FL       EP052022
500 PM HST Sun Jul 10 2022

Darby has continued to strengthen since the last advisory. Deep 
convection near and over its center has been persistent during the 
past several hours, and a series of passive microwave images 
revealed a well-defined inner core structure has developed 
underneath Darby's small central dense overcast. Although the 
subjective Dvorak classifications at 00 UTC were a consensus T3.5/55 
kt, the objective ADT and SATCON estimates have recently climbed as 
high as 72 kt based on the improved microwave structure of the 
storm. Based on these trends, the initial intensity is set at 65 kt 
for this advisory, which makes Darby the fourth eastern North 
Pacific hurricane this season.

The near-term environmental conditions remain favorable for 
additional strengthening, as Darby is forecast to move over warm 
SSTs within a low deep-layer shear environment. Although the small 
hurricane could be susceptible to additional bouts of dry-air 
entrainment, the improved inner-core structure of Darby should allow 
the cyclone to continue intensifying over the next day or so before 
it reaches cooler waters by Wednesday. The official intensity 
forecast is slightly above the previous one and remains on the high 
end of the guidance, slightly higher than the HFIP corrected 
consensus approach (HCCA) and the SHIPS guidance. By midweek, Darby 
is forecast to encounter drier mid-level air as it crosses the 26 C 
isotherm, which should induce a weakening trend. Given its small 
size, Darby should weaken quickly later in the period, and the day 5 
forecast shows Darby as a 30-kt post-tropical remnant low.

Darby's motion is just a bit north of due west at 275/15 kt. Darby 
will continue moving quickly westward for the next couple of days, 
to the south of an established mid-level ridge that extends across 
the eastern North Pacific. As the cyclone reaches the southwestern 
extent of the ridge, it is forecast to turn west-northwestward later 
this week. There is still some along-track spread noted among the 
various global models, with the UKMET much faster and farther south 
than the GFS and ECMWF solutions at later forecast times. The 
official NHC track forecast remains very close to the previous one, 
and is generally just a bit north of the consensus aids and closer 
to the GFS/ECMWF consensus (GFEX). 


FORECAST POSITIONS AND MAX WINDS

INIT  11/0300Z 14.6N 120.6W   65 KT  75 MPH
 12H  11/1200Z 14.7N 122.6W   75 KT  85 MPH
 24H  12/0000Z 14.9N 125.2W   80 KT  90 MPH
 36H  12/1200Z 15.1N 127.8W   85 KT 100 MPH
 48H  13/0000Z 15.4N 130.4W   80 KT  90 MPH
 60H  13/1200Z 16.0N 132.9W   70 KT  80 MPH
 72H  14/0000Z 16.7N 135.3W   60 KT  70 MPH
 96H  15/0000Z 18.0N 140.5W   40 KT  45 MPH
120H  16/0000Z 18.5N 145.5W   30 KT  35 MPH...POST-TROP/REMNT LOW

$$
Forecaster Reinhart




Source link