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Hurricane Gilma Discussion Number 17
NWS National Hurricane Center Miami FL EP072024
Issued by the NWS Weather Prediction Center College Park MD
500 AM HST Thu Aug 22 2024
Gilma has continued to intensify with recent tightening of the
eyewall diameter in the last few hours. Concurrently, solid cooling
was noted in the surrounding inner ring of convection. This
has resulted in an increase in intensity for the Dvorak intensity
estimates with TAFB up to a T6.0/6.0 or 115 knots while
objective estimates from UW-CIMSS has seen a variation of Raw-T
values between 5.5 and 5.8. As such, the intensity has been
adjusted slightly upward to 110 knots and brings intensity up to
a strong Category 3 hurricane on the Saffir-Simpson Scale.
A northwest trend in center fixes continues to show slow forward
speed at 290/6 knots, though small wobbles have been noted as the
eye has been tightening and stronger convergence nodes are noted
along the inner eye wall supporting a weak asymmetry to the eye
itself. Given weak mid-tropospheric forcing, storm motion will
continue to be slow and is expected to turn more westward Friday
into Saturday as it nears the 26-27C isotherm. Proximity to the
thermal gradient and convective activity will play a role in the
longer term forecast as well. Depending on the strength, a faster
forward speed was noted through the guidance suite. As such, the
official forecast is a bit faster along track though the track
remains fairly stable.
Given that warmer oceans remain along the track of Gilma, some
additional strengthening is expected with the low shear
environment. As the cyclone reaches the 26-27C isotherm, gradual
weakening is expected, but a slight northward adjustment will
result in reduced warm, moist air to maintain its strength and
slow weakening is expected after Friday morning. As the storm
treads further west, cooler water is likely to increase weakening of
the system through the weekend into early next week. As the system
weakens and becomes shallower, forward speed will increase and
perhaps further compound the weakening process a bit faster than
prior forecast; however, the NHC intensity forecast
remains on the higher end of the model guidance suite to better
maintain continuity.
FORECAST POSITIONS AND MAX WINDS
INIT 22/1500Z 16.9N 124.5W 110 KT 125 MPH
12H 23/0000Z 17.1N 125.4W 115 KT 130 MPH
24H 23/1200Z 17.5N 126.8W 105 KT 120 MPH
36H 24/0000Z 17.8N 128.3W 100 KT 115 MPH
48H 24/1200Z 18.1N 129.9W 95 KT 110 MPH
60H 25/0000Z 18.3N 131.5W 90 KT 105 MPH
72H 25/1200Z 18.4N 133.3W 80 KT 90 MPH
96H 26/1200Z 18.8N 137.1W 65 KT 75 MPH
120H 27/1200Z 19.1N 141.3W 55 KT 65 MPH
$$
Forecaster Gallina
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