Your Number One Source for Real-Time Puerto Rico Weather & Hurricane Tracking Updates

620
FXCA62 TJSJ 061840
AFDSJU

Area Forecast Discussion
National Weather Service San Juan PR
240 PM AST Thu Aug 6 2026

...New SHORT TERM, LONG TERM, AVIATION, MARINE, BEACH FORECAST, FIRE WEATHER, CLIMATE...

.KEY MESSAGES...
Issued at 235 PM AST Thu Aug 6 2026

- Hot and hazardous conditions will persist through the weekend, with
  above-normal temperatures and dangerous afternoon heat indices
  expected across Puerto Rico and the U.S. Virgin Islands.
  Additional heat products will likely be needed in the coming
  days.

- A drier and more stable weather pattern will develop tonight
  and persist through the weekend. Limited rainfall is expected,
  allowing drought conditions to continue worsening across Puerto
  Rico and the U.S. Virgin Islands. Moderate concentrations of
  Saharan dust are expected to arrive late this weekend, resulting
  in hazy skies and occasional reductions in visibility.

- Elevated fire weather conditions will continue through this afternoon
  across southern and southwestern Puerto Rico due to critically
  dry fuels, low relative humidity, and breezy easterly winds. A
  Fire Danger Statement remains in effect, and residents should
  avoid outdoor burning and activities that could generate sparks
  or open flames.

&&

.Short Term(This evening through Saturday)...
Issued at 235 PM AST Thu Aug 6 2026

Mainly tranquil conditions continued in the morning hours, with few
isolated showers moving south of Ponce. High clouds associated with
an upper-level low near Jamaica moved across the region, affecting
mainly the U.S. Virgin Islands and eastern Puerto Rico. Minimum
temperatures were slightly warmer than yesterday, with urban and
coastal areas in the mid 70s to lower 80s (80 degrees Fahrenheit at
the LMM International Airport) while interior portions of Puerto
Rico remained in the 60s. As of 2 PM AST, maximum temperatures
ranged between the upper 80s and lower 90s across urban and low-
lying areas, with the ASOS at the LMM International Airport
reporting 92 degrees Fahrenheit (record set at 93 degrees
Fahrenheit). The 12z RAOB came very dry compared to the 05/12z
sounding, as a drier-than-normal airmass continues to filter into
the region. In the mid-levels, the sounding reported RH values of
35%, while low-level moisture dropped only 10%. Although conditions
will gradually become stable, lingering moisture and slight
instability will lead to showers and isolated thunderstorms over the
western side of Puerto Rico. An Special Weather Statement was in
effect through 1830z. Nevertheless, rainfall accumulations should
remain localized with at most ponding of water over roadways and
poorly drained areas.

The weather pattern will continue to be dominated by the surface
high pressure building over the Western Atlantic, maintaining winds
from the E-SE for the rest of today, though the may shift from the E-
ENE on Friday and Saturday. The latest satellite-derived products
show stable and drier-than-normal airmass that should continue to
filter into the region, with PWAT values around 1.25 inches. From the
latest model guidance, these values may range between 1.2 and 1.4
inches as patches of moisture arrive from time to time, bringing
occasional showers during the night into morning hours over windward
sections. In terms of instability, an upper-level low approaching
the region could lower heights and slightly cool mid-level
temperatures (500 mb temperatures between -5 and -6 degrees
Celsius). Nevertheless, the CWA will likely be under the subsidence
side of the low, with sinking air and stability above that should
inhibit deeper convection activity. HIRES models suggests that
afternoon convection should start over portions of interior and
western/southwestern Puerto Rico. Due to the combination of local
effects, daytime heating, and sea breeze convergence, isolated
thunderstorms could be possible over the aforementioned areas.
Nevertheless, widespread showers are not expected and flooding
impacts if any should lead to localized ponding of water over
roadways and flood-prone areas. This pattern should repeat on
Wednesday as well, though a dense SAL approaching the Caribbean
Basin will gradually filter by late Saturday, inhibiting deep
convection. Sensitive groups must follow medical recommendations.

As mentioned in the previous discussions, the heat remains as the
primary hazard as warmer than normal conditions continue across the
CWA. Although winds should become from the E-ENE, highs should
remain in the upper 80s and low 90s across urban and low-lying areas
during the peak hours of the day, with heat indices exceeding a 100
degrees Fahrenheit. These levels of heat could affect mainly
individuals sensitive to heat or those without adequate hydration
and/or effective cooling. Hence, the heat threat will remain
elevated throughout the forecast period, and heat products may be
required. On the other hand, extreme heat warnings cannot be ruled
out.

&&

.Long Term(Sunday through next Wednesday)...
Issued at 246 AM AST Thu Aug 6 2026

A progressive weather pattern is expected as tropical waves,
easterly wind surges, and a TUTT low move through or near the
eastern Caribbean. The first wave will approach Sunday and move
across the region through Monday. Although the deepest moisture
should remain mainly over the Caribbean waters, Sunday and Monday
currently appear to have the greatest potential for increased shower
and thunderstorm coverage. Afternoon convection should be most
noticeable over interior and western Puerto Rico, with an elevated
lightning risk where thunderstorms develop.

A brief period of lower moisture is possible late Monday into early
Tuesday, followed by a strong easterly wind surge. Breezy to windy
conditions will prevail through much of the period, with Tuesday
potentially becoming the windiest day. Moisture may increase again
from Wednesday into Thursday as another tropical wave approaches,
but confidence in its timing and associated rainfall remains low.
Wednesday could become the warmest day if cloud and shower coverage
remains limited, with elevated to significant heat risks continuing
through the period.

Despite occasional increases in moisture and convection, widespread
or prolonged rainfall is not anticipated. Therefore, significant
relief from the ongoing severe drought and water-supply concerns is
unlikely. Rainfall and lightning impacts will depend greatly on the
timing of each feature and how much tropical moisture reaches the
local islands.

&&

.AVIATION...
(18Z TAFS)
Issued at 235 PM AST Thu Aug 6 2026

VFR conds will continue across all terminals. Aftn convtn will lead
to -TSRA across W/NW PR, with VCTS over JBQ. Although most -TSRA
should remain in the vicinity, AMDs will be issued if required.
Winds from the E-SE will continue this aftn, btwn 11-16 kt, with
gusts up to 22-24 kt, weakening and becoming VRB by 06/23z.
Increasing winds btwn 11 - 16 kt with gusts up to 25kt should become
from the E-ENE by 07/12-13z. VCSH could be expcd over the USVI TAFs
in the early morning, followed by aftn convtn over W/SW PR.

&&

.MARINE...
Issued at 235 PM AST Thu Aug 6 2026

A tightening pressure gradient between high pressure over the
central Atlantic and lower pressure across the Caribbean will
promote fresh east to east-southeast winds tonight through the
weekend, resulting in choppy marine conditions across the Atlantic
waters, local passages, and portions of the Caribbean waters. Seas
will generally range between 3 and 5 feet, occasionally up to 6 feet
offshore. Moderate concentrations of Saharan dust are expected to
arrive late Friday and persist through the weekend, occasionally
reducing visibility. Small craft operators should continue to
exercise caution and monitor the latest forecasts.

&&

.BEACH FORECAST...
Issued at 235 PM AST Thu Aug 6 2026

A moderate risk of rip currents continues across the north-facing
beaches of Puerto Rico due to persistent easterly winds and wind-
driven waves. Elsewhere, including the U.S. Virgin Islands, the rip
current risk remains generally low through the afternoon. As
easterly winds strengthen tonight and through the end of the week,
the rip current risk is expected to increase for Culebra and St.
Croix and may expand to additional exposed east-facing beaches.
Beachgoers should remain aware of changing surf conditions and heed
the advice of local officials and beach warning flags. Heat
continues to be the primary beach hazard through the remainder of
the day, while isolated thunderstorms affecting western Puerto Rico
through late afternoon may produce dangerous cloud-to-water
lightning near area beaches before dissipating this evening.

&&

.FIRE WEATHER...
Issued at 235 PM AST Thu Aug 6 2026

Elevated fire weather conditions continue this afternoon across
southern and southwestern Puerto Rico, where critically dry fuels,
low relative humidity, and breezy easterly winds are supporting an
increased risk for wildfire ignition and spread. Relative humidity
values have fallen into the upper 40s to lower 50s across portions
of the southern coastal plains while sustained east winds of 15 to
20 mph, with higher gusts, continue to promote rapid fire growth
should any fires develop. Although isolated showers remain possible
across the interior and western sections of Puerto Rico through late
afternoon, rainfall coverage and amounts are expected to be
insufficient to provide meaningful relief over the southern coastal
plains, where fuels remain critically dry.

A drier and more stable weather pattern will become established
tonight and persist through the weekend as mid-level ridging
strengthens and moisture decreases. Easterly trade winds will remain
breezy each day, while afternoon minimum relative humidity values
are expected to trend lower, particularly across southern Puerto
Rico and the U.S. Virgin Islands. Combined with ongoing rainfall
deficits and critically dry fine fuels, these conditions will
support an elevated to locally critical fire weather threat each
afternoon, especially across the southern and southwestern coastal
plains of Puerto Rico. Residents and visitors should continue to
avoid outdoor burning and exercise caution with activities capable
of producing sparks or open flames, as favorable conditions for
wildfire ignition and rapid spread are expected to persist through
the weekend.

&&

.CLIMATE...
Issued at 235 PM AST Thu Aug 6 2026

Drought conditions continue to deteriorate across Puerto Rico and
the U.S. Virgin Islands. Extreme Drought (D3) has been introduced
across the southern coastal plains of Puerto Rico. The most
significant impacts are agricultural, although dry rivers and soils,
along with significant rainfall deficits, also supported this
classification. Severe Drought (D2) has also expanded across
portions of the interior and eastern sections of Puerto Rico.
Localized water service interruptions are affecting some of these
areas as surface water reservoirs continue to decline.

In the U.S. Virgin Islands, Exceptional Drought (D4), the highest
drought classification, has also been introduced. Impacts to cattle
and poultry are significant. Additional impacts include insufficient
rainfall to replenish cisterns, stressed vegetation, and the
depletion of groundwater wells.

&&

.SJU WATCHES/WARNINGS/ADVISORIES...
PR...Heat Advisory until 5 PM AST this afternoon for PRZ001>005-007-
     008-010>013.

VI...Heat Advisory until 5 PM AST this afternoon for VIZ001-002.

AM...None.
&&

$$

SHORT TERM/AVIATION...MNG
LONG TERM...ICP
MARINE/BEACH/FIRE...CVB
CLIMATE...ERG-CVB

NWS SJU Office Area Forecast Discussion