Weather Watchers

https://www.nhc.noaa.gov/text/refresh/MIATCDAT3+shtml/261459.shtml?

After rapidly intensifying over the past day or so, NOAA-P3 aircraft
data indicates that Melissa's intensity has leveled off this
morning. Melissa remains a very formidable hurricane on satellite
imagery, with a clearing eye quite evident on morning visible
imagery, and the eye temperature has warmed to +15-20C. Meanwhile
the eyewall convection continues to remain robust with cloud tops as
low as -75 to -80C encircling the core. With that said, the eye
presentation from the Kingston, Jamaica radar is not as pristine,
with the eyewall occasionally open on the east side, and some
evidence of concentric bands forming off and on. Zooming out a bit,
there still remains some evidence of light to moderate westerly
shear undercutting the expanding storm outflow, and Melissa’s
primarily rainbands are distributed mostly on the eastern side of
the circulation. NOAA-P3 aircraft data this morning had a peak 700-
mb flight level wind of 120 kt, and Tail Doppler Radar (TDR) wind
retrievals were up to 129 kt at 0.5 km, and 129 kt in the 500 m
average of a dropsonde launched in the north eyewall. While this
data would support a somewhat lower intensity, the subjective and
objective satellite based intensity estimates are mostly higher,
ranging from 115 to 140 kt. The initial intensity will be held at
120 kt, on the lower end of those estimates, and this value could be
a little generous based on the aircraft data.

The major hurricane is moving westward this morning, from aircraft
fixes estimated at 270/3 kt. This motion is expected to continue for
the next 24-36 h as a narrow mid-level ridge to the north of Melissa
imparts the majority of the steering. Thereafter, a short-wave
trough moving into the southeastern United States is expected to
erode this ridge, allowing Melissa to turn sharply to the northeast,
with gradual acceleration. On the forecast track, Melissa's core
is expected to be near the Jamaica coastline by Tuesday morning,
moving across the island and then approaching and moving over
eastern Cuba by Tuesday night. While the track guidance has become
tightly clustered over the first 24-48 hours, the along-track spread
starts to increase significantly after that time period, with Google
DeepMind ensemble solutions on Wednesday morning ranging from
between Jamaica and eastern Cuba in the Caribbean Sea, over eastern
Cuba, or in the Southwestern Atlantic near the Southeastern Bahamas
and Turks and Cacaos Islands. The latest NHC track forecast was
nudged just a little westward of the prior track, once again
blending the reliable track aids HFIP Corrected Consensus Approach
(HCCA), and Google DeepMind ensemble mean (GDMI).

It is unclear if the current pause in Melissa's intensification is
temporary. While there have not been obvious indications of a
secondary eyewall formation yet, there are some concentric
reflectivity bands appearing on both Jamaica and NOAA-P3 TDR data
occasionally, though the inner eyewall remains strong. Some of the
guidance this morning has actually increased from yesterday at this
time, and notably both the HAFS-A/B explicitly forecast a Category 5
hurricane shortly before they show landfall in Jamaica. The latest
NHC intensity forecast will continue to show a peak intensity of 140
kt. However, inner-core fluctuations like eyewall replacement cycles
could occur at any time. Regardless, Melissa is forecast to reach
Jamaica as an upper-end category 4 hurricane, which will only
exacerbate any damages caused by heavy rainfall and flooding over
the next 2 days. Melissa will likely weaken some as it traverses
over the higher terrain of Jamaica, but it is still forecast to be a
major hurricane when it subsequently moves over eastern Cuba in
60-72 hours. Thereafter, increasing southwesterly shear should
cause gradual weakening, but Melissa could still be near hurricane
intensity when it makes it closest approach to Bermuda in about 5
days. The latest NHC intensity forecast is on the high end of the
intensity guidance, but not far off the GDMI, and HAFS-A/B intensity
aids.
(snip)