Atlantic Hurricane Season 2024 Storm Names

503
FXCA62 TJSJ 200816 CCA
AFDSJU

Area Forecast Discussion...CORRECTED
National Weather Service San Juan PR
416 AM AST Mon May 20 2024

.SYNOPSIS...
Hot conditions will prevail across the local islands through
Tuesday. Some Saharan dust will linger around too, resulting in
hazy skies. Then, it will become unsettled and wet, as a trough
develops west of the islands. The risk for flooding and mudslides
will increase for the second half of the workweek. Conditions will
gradually improve during the weekend.

&&

.SHORT TERM...Today through Wednesday...
Showers lingered across northwestern Puerto Rico during the early
night hours and then across the local waters onward through the
morning with some light showers brushing the eastern coastal
region of Puerto Rico. Another hot day is expected with a Heat
Advisory in place for all coastal areas of Puerto Rico and the
USVI today from 10 AM to 6 PM local time.

An area of weak high pressure across the central Atlantic and low
pressure at the surface in the western Atlantic will allow light to
moderate southeasterly flow to prevail through Wednesday. This will
bring warmer than usual temperatures across the islands, especially
for coastal areas that are expected to have heat indices between 100
and 110, some isolated areas higher. Due to this, heat advisories
are anticipated through at least tomorrow. Relatively normal
precipitable water values through tomorrow will allow a seasonal
passing showers and afternoon convection to prevail, with north
western Puerto rico having the best chance of rain during the
afternoon hours.

Conditions will begin to shift to a wetter pattern by Wednesday
morning as as a deep layered trough moves through the Caribbean
basin, raising a moist airmass into the region. Models hint that the
strongest segment of the jet aloft will remain well to the northwest
of the area. However, 500 mb temperatures and precipitable water
values are forecast to reach values that bring the expectation of
numerous showers and scattered thunderstorms. Surface winds will
also strengthen over Wednesday night due to the development of a
surface trough west of the region. Due to this squally weather,
the risk of flooding becomes present for areas that receive heavy
rainfall. This is the beginning of a wet pattern as Wednesday
appears to be the first day of this rain event which is expected
to last through the weekend.

.LONG TERM...Thursday through Monday
On Thursday, the islands will be squeezed between a surface high
pressure over the central Atlantic and a surface trough/low over
Hispaniola. Plenty of moisture will stream from the Caribbean Sea
into the islands, with precipitable water values above 2.5 inches
possible (above climatology). Additionally, pockets of vorticity
at the mid levels will be advected into the islands, hence
conditions will favor the continuation of showers and
thunderstorms over the region into Friday. It is not that it will
rain all the time, but these showers could be heavy from time to
time, maintaining elevated the risk for flooding, mudslides and
rapid river rises. Also, early on Thursday, as the low lifts
northward, a swath of winds will move over the region, bringing
gusts of 20-25 knots with the heavy showers and thunderstorms.

By the weekend, trailing moisture from the low, now expected to
be well north of Puerto Rico will continue to impact the region.
Although the rain is not expected to be as widespread, it could
aid in the development of convection for the interior, north and
west of Puerto Rico in the afternoon. Some showers will also move
in the vicinity of the Virgin Islands.

On Sunday and Monday, some improvement is anticipated, mostly for
the Virgin Islands and eastern Puerto Rico, but conditions will
remain very favorable for afternoon activity, again for the
interior, northern and western Puerto Rico.

The heat risk was maintained below the limited criteria for
Wednesday and Thursday, mostly because of the cloud coverage, but
it is expected to be back again Friday onward, when the sun peeks
once more across the northeastern Caribbean archipelagos.

&&

.AVIATION...
(06Z TAFS)
Mainly VFR conditions expected to prevail. SHRA will
move across the local waters, and could reach the USVI and PR
terminals at times. After 16z an increase of rain is expected
across the Cordillera Central and around TJBQ, where periods of
reduced VIS and low ceilings are possible. Winds will from the SE
at 8-13 kts, with stronger wind gusts and sea breezes variations.

&&

.MARINE...
A surface high pressure across the central and northeast Atlantic
will drive the trade winds from the southeast at moderate speed.
A trough will develop south of Hispaniola, increasing shower and
thunderstorm activity across the local waters Wednesday onward. This
trough may increase winds across the Mona Passage and Atlantic waters
Wednesday night into Thursday.

&&

.CLIMATE...
The record high for today for San Juan Area is 92, set in 1999.
The forecast high is 93F, so if the forecast verifies, a new daily
maximum record will be set today for this climate site.

&&

.SJU WATCHES/WARNINGS/ADVISORIES...
PR...Heat Advisory from 10 AM this morning to 6 PM AST this evening
     for PRZ001>003-005-007-008-010>013.

VI...Heat Advisory from 10 AM this morning to 6 PM AST this evening
     for VIZ001-002.

AM...None.
&&

$$

SHORT TERM...RC
LONG TERM....ERG

NWS SJU Office Area Forecast Discussion