Central Pacific Basin Tropical Cyclones

Tropical Storm Hone Forecast Discussion



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WTPA41 PHFO 240238
TCDCP1

Tropical Storm Hone Discussion Number   7
NWS Central Pacific Hurricane Center Honolulu HI   CP012024
500 PM HST Fri Aug 23 2024

The U.S. Air Force Reserve Hurricane Hunter aircraft sampled 
Tropical Storm Hone from this morning into early afternoon and 
provided valuable data. In spite of its lack of convection, Hone 
maintained a well-developed low cloud field and remained 
surprisingly intense through the morning, well above Dvorak inputs 
from the fix agencies. Late this afternoon, deep convection is 
redeveloping near the center as winds aloft ease. The latest data 
from the Hurricane Hunters came in just before 00Z and showed 
maximum sustained winds holding at 45 kt and a minimum sea level 
pressure of 1000 mb. Given the appearance of Hone, these values 
will be used for the initial intensity.

The initial motion is unchanged at 280/14. This general motion 
toward slightly north of due west will continue during the next 
several days as Hone is steered by a deep subtropical ridge to the 
north. However, some slowing of the forward motion is anticipated 
as the deep ridge to the north of Hone weakens slightly. Along this 
track, Hone will be passing near or just south of the state late 
Saturday into early Sunday, which necessitates the issuance of a 
Tropical Storm Warning for the Big Island of Hawaii. By the middle 
of next week, Hone will likely become increasingly shallow as 
vertical wind shear increases, allowing the low level trade wind 
flow to steer the system toward the west. The official forecast 
track is nearly identical to the previous advisory, and closely 
follows the tightly clustered consensus guidance near the TVCN.

Hone has a window for intensification during the next 36 to 48 
hours. Easterly winds aloft, which have inhibited outflow in all 
but the south and southwest quadrants, will relax tonight and 
Saturday as a weakness develops in the upper level ridge north of 
the cyclone. Sea surface temperatures will remain around 26-27C, 
which will be sufficient for intensification, possibly to hurricane 
strength, late Saturday or early Sunday. Late Sunday and Monday, 
west to northwest vertical wind shear will increase sharply, which 
should result in steady weakening. The intensity forecast remains 
on the higher side of the guidance envelope near the HCCA and 
slightly higher than the IVCN. Beyond 48 hours, the forecast closely 
follows the IVCN.

KEY MESSAGES:

1. There is the potential for excessive rainfall and flash flooding
on portions of the Big Island of Hawaii starting later Saturday 
and continuing through Sunday as a large area of moisture 
associated with Hone moves over parts of the Hawaiian Islands. The 
heaviest rainfall will likely occur over windward and southeast 
facing slopes.

2. Tropical storm conditions are possible on the Big Island later
Saturday into Sunday. Winds are expected to be strongest where they
blow downslope from higher terrain, over headlands, and through
passes.

3. Swell generated by Hone is expected to reach the Hawaiian
islands Saturday night into Sunday. This swell could cause
life-threatening surf and rip currents. Listen for later advisories
and possible warnings from the National Weather Service.


FORECAST POSITIONS AND MAX WINDS

INIT  24/0300Z 16.9N 149.3W   45 KT  50 MPH
 12H  24/1200Z 17.3N 151.4W   50 KT  60 MPH
 24H  25/0000Z 17.6N 154.1W   55 KT  65 MPH
 36H  25/1200Z 17.9N 156.4W   60 KT  70 MPH
 48H  26/0000Z 18.2N 158.5W   65 KT  75 MPH
 60H  26/1200Z 18.6N 160.6W   60 KT  70 MPH
 72H  27/0000Z 19.0N 162.5W   55 KT  65 MPH
 96H  28/0000Z 19.7N 165.7W   50 KT  60 MPH
120H  29/0000Z 20.4N 168.8W   35 KT  40 MPH

$$
Forecaster Wroe



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