Weather Watchers

https://www.nhc.noaa.gov/text/refresh/MIATCDAT3+shtml/271448.shtml?

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Melissa has the classic strong hurricane appearance in satellite
imagery this morning, with a well-defined 10-nm wide eye embedded
in a central dense overcast with cloud tops colder than -80C. The
hurricane also has a large complex of outer banding over the
eastern semicircle and a circulation that covers most of the
Caribbean west of 70 degrees west longitude. Reports from NOAA and
Air Force Reserve Hurricane Hunter aircraft indicate the central
pressure has fallen to near 908 mb, with both aircraft releasing
dropsondes in the northeastern eyewall that support an initial
intensity of 145 kt. The NOAA aircraft left the storm early after
experiencing severe turbulence in the southwestern eyewall.

The eye is wobbling around due to the slow motion, but the best
estimate of the initial motion is 270/3 kt. The mid-level ridge
north of Melissa is weakening as a deep-layer mid-latitude trough
moves eastward through the southeastern United States. This should
cause the hurricane to turn northward during the next 12 h or so at
a continued slow forward speed. After 24 h, Melissa should turn
northeastward with some increase in forward speed as the
mid-latitude westerly flow becomes the dominant steering
mechanism. This general motion should continue for the rest of the
forecast period. On the forecast track, the center of Melissa will
be near or over Jamaica late tonight or early Tuesday, cross
eastern Cuba Tuesday night or early Wednesday, and then move near
or over the Bahamas and the Turks and Caicos on Wednesday. After
that, the cyclone could reach the vicinity of Bermuda on Thursday
night. The new forecast track has some minor adjustments from the
previous track and is a blend of the HFIP Corrected Consensus, the
Google DeepMind ensemble mean, and the other consensus models.

Some fluctuations in intensity are likely during the next 12-24 h
due to the possibility that Melissa will start an eyewall
replacement cycle. However, this is unlikely to weaken Melissa
significantly, and there is no practical difference in Melissa
making landfall in Jamaica at category 4 or 5 intensity, since both
categories produce catastrophic wind damage. After reaching Jamaica,
a combination of land interaction and increasing southwesterly shear
should cause some weakening, although Melissa is still forecast to
be a major hurricane when it reaches Cuba. Once over the Atlantic,
stronger shear should cause more substantial weakening, and Melissa
is expected to become extratropical by the end of the forecast
period. The new intensity forecast has minor adjustments from the
previous and follows the trend of the intensity consensus.


Key Messages:

1. Jamaica: Do not venture out of your safe shelter. Catastrophic
and life-threatening flash flooding and numerous landslides are
likely today through Tuesday. Catastrophic winds in the eyewall have
the potential to cause total structural failure especially in higher
elevation areas tonight and early Tuesday. This will result in
extensive infrastructural damage, long-lasting power and
communication outages, and isolated communities. Life-threatening
storm surge and damaging waves are expected along the southern coast
through Tuesday.

2. Haiti and the Dominican Republic: Catastrophic and
life-threatening flash flooding and landslides are expected across
southwestern Haiti and southern portions of the Dominican Republic
through midweek. In Haiti, extensive infrastructural damage and
isolation of communities is likely. Tropical storm conditions are
expected late Tuesday and Wednesday.

3. Eastern Cuba: Heavy rainfall with life-threatening and
potentially catastrophic flash flooding and landslides is expected
beginning today. Life-threatening storm surge and damaging winds are
expected late Tuesday and Tuesday night. Preparations should be
rushed to completion.

4. Southeast Bahamas and the Turks and Caicos: Hurricane conditions,
life-threatening storm surge, and heavy rainfall are possible on
Wednesday. Residents should follow advice given by local officials
and be sure to have preparations complete by Tuesday night.
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