Puerto Rico, 2022

Flash Flooding and Debris Flow in Puerto Rico, July 10, 2022

July 10, 2022 · NWS SJU · 13 events in 4 counties and zones

An induced surface trough and a tropical wave approaches the islands. At the same time, an upper level trough dug from the northeast, providing instability aloft.

Where it happened

Every event with a place to put it. Tap one for its entry below.

  • Tornadoes
  • Tropical storms and surge
  • Floods
  • Wind
  • Hail
  • Winter weather
  • Heat and drought
  • Cold
  • Fire, smoke and dust
  • Marine and coastal
  • Other

Open the live radar over this ground

The toll

Deaths
0
Injuries
0
Property damage
$5,000
Crop damage
None recorded
Events
13

Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.

What happened

The episode as NWS SJU wrote it up.

An induced surface trough and a tropical wave approaches the islands. At the same time, an upper level trough dug from the northeast, providing instability aloft. The combination of these features resulted in periods of heavy rain and gusty winds, with multiple flooding reports received.

What forecasters said that day

The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS San Juan, PR wrote its last area forecast discussion before the first event at Jul 10, 10:29 AM AST, 3 hours 1 minute earlier.

Area forecast discussion, Jul 10, 10:29 AM AST, 3 hours 1 minute before
Area Forecast Discussion
National Weather Service San Juan PR
1029 AM AST Sun Jul 10 2022

.UPDATE...

No significant changes to forecast and reasoning.

Moisture has continued to increase over the area. The precipitable
water from the 12Z upper air sounding is 2.04 inches. Moisture
extends into the mid-levels, as well; though there is a narrow drier
layer with RH values to near 50% at around 700 hPa, there is not a
deep dry layer until about 550 hPa. The upper-level low is making
its way into the area, though the center remains to the northeast:
based on Air Mass RGB imagery from GOES-East, it is located around
22.5N 60.0W, or about 400 miles northeast of St. John in the USVI.
It is expected to continue to retrograde, slipping southwestward
over the next couple of days, bringing increased instability over
the area. This will provide additional dynamical support for
convective activity over the region. We are therefore still
expecting another active afternoon today. Winds from the sounding
were out of the east-southeast to about 600 hPa/5km. This suggests
that activity will be focused on western/northwestern and interior
Puerto Rico. However, winds gain a bit of a northerly component
above that, and even become northerly around 450 hPa/6.5-7km;
above that, the northerly component is effectively maintained
through the tropopause. Therefore, there is the potential for some
of the shower activity to drift into southwestern/south central
portions of Puerto Rico.

&&

.AVIATION...

Generally VFR conds expected next 24 hours across all terminals,
though temporary MVFR to IFR conds at TISX through 10/13Z due to
SHRA. VCSH during afternoon TIST/TISX are for streamers, most of
which will stay downwind of aerodromes. VCTS expected TJBQ 10/16-
23Z; most will stay S of aerodrome, but brief MVFR or worse cannot
be entirely ruled out, and similarly with VCSH at TJSJ from
streamers. Winds out of the east 12 to 18 knots, with sea breeze
variations and stronger gusts subside after sunset to 6 to 12 knots.

&&

.MARINE...

No changes. Seas of 6 feet or less are expected for most of the
local waters, but seas of up to around 7 feet for the offshore
Atlantic waters. This is as moderate to fresh winds, with speeds of
up to around 20 to 22 knots, sustains choppy conditions across the
waters.

There is still a high risk of rip currents for beaches of
northwestern and north central Puerto Rico, and for Cramer Park in
eastern St. Croix. Nearly all other beaches have a moderate risk of
rip currents.

&&

.PREV DISCUSSION... /issued 456 AM AST Sun Jul 10 2022/

SYNOPSIS...

A tropical wave and an upper-level trough will bring showers and
thunderstorms across the local islands today. The retrograding
tropical upper tropospheric trough (TUTT) will linger aloft
through late Tuesday. A Saharan Air Layer (SAL) will create hazy
skies from Monday onward. Unstable weather conditions will return
Friday through Sunday.

SHORT TERM...Today through Tuesday...

An upper level low is currently located northeast of the islands,
while a tropical wave approaches the Lesser Antilles. In the middle
of the Atlantic, a surface high pressure remains anchored, creating
a moderate wind flow out of the east-southeast. The instability
provided by the upper level low will combine with the moisture
provided by the wave and local effects to result in another active
afternoon across the interior, northern and western Puerto Rico.
Some of these storms could be strong at times, with periods of heavy
rain, gusty winds and frequent lightning. Urban and small stream
flooding are expected.

By late Sunday or early Monday, the tropical wave will part ways
into the central Caribbean Sea, and a Saharan Air Layer will follow.
Skies will turn hazy and visibilities will be reduced at least
through mid-week. Moisture content is expected to drop to around 1.6
inches, which is near normal. Although shower activity is expected
to be reduced to the lack of low level moisture, it will not be
completely dry. The upper level low will induce small pockets of
moisture that will be advected into the area at times. Additionally,
this low will dig even closer to the area, dropping 500 mb
temperatures  to around -12 degrees Celsius. With this increased
instability aloft, and with strong diurnal heating, isolated, but
strong thunderstorms are expected each afternoon. However, the
activity should not be widespread, focusing along northwestern
Puerto Rico in the afternoon hours.

LONG TERM...Wednesday through Sunday...

A mid to upper-level ridge will replace a TUTT and reinforce a
trade wind inversion Wednesday and Thursday. In addition, an
extensive Saharan Air Layer will also limit the available moisture
and rain activity, promoting hazy skies through at least Thursday.
However, due to local effects, diurnal heating, and sea breeze
variations, thunderstorms could develop across the western
sections of Puerto Rico and downwind from La Sierra de Luquillo
each day. The SAL will reduce nighttime cooling resulting in
above-normal minimum temperatures each day, which will be easier
for the highs to reach the 90s each day. Although moisture content
will be less than normal, heat indices could surpass 100 degrees
Fahrenheit each afternoon.

The ridge will erode as another retrograding TUTT swings by the
islands Friday through Saturday. While at the surface, a tropical
wave will increase the available moisture on Friday, followed by a
trade wind perturbation (wind surge) on Saturday and a strong
tropical wave on Sunday. Although ECMWF and GFS have some
discrepancies regarding the position of the TUTT, which could
impact the frequency and intensity of the convective activity, we
are putting more weight on GFS (because its solution is closer to
what is happening now). Consequently, a moist and unstable
weather pattern could be possible by Friday into the following
weekend.

AVIATION...

VFR conditions are expected to prevail through the forecast period.
SHRA will continue to move across the U.S. Virgin Islands and TJSJ
terminals through the period. After 17Z, VCTS are expected at TJBQ,
and these conditions could result in periods of reduced VIS and low
ceilings. Afternoon convection will cause mountain obscuration
across the Cordillera Central and western Puerto Rico. Winds will be
out of the ESE at 10 to 15 knots with stronger gusts and sea breeze
variations.

MARINE...

Mariners can expect breezy trades promoting choppy to
hazardous seas up to 7 feet across portions of the Atlantic
waters, where a Small Craft Advisory is in effect until 2 PM AST,
this afternoon. Elsewhere, small craft operators should exercise
caution due to choppy seas up to 6 feet and easterly winds of 15
to 22 knots but gusty near the thunderstorms.

Beachgoers, there is a high risk of rip currents from Aguadilla to
Dorado and at Cramer Park, and a moderate risk elsewhere across
the rest of the islands.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU  87  77  90  79 /  60  60  50  40
STT  88  80  88  80 /  50  60  30  30

&&

.SJU WATCHES/WARNINGS/ADVISORIES...
PR...High Rip Current Risk through late tonight for North Central-
     Northwest.

VI...High Rip Current Risk through late tonight for St Croix.

AM...Small Craft Advisory until 2 PM AST this afternoon for Atlantic
     Waters of Puerto Rico and USVI from 10 NM to 19.5N.

&&

SHORT TERM...CRS
LONG TERM....OMS
PUBLIC DESK...MRR
Hazardous weather outlook, Jul 10, 4:33 AM AST, 8 hours 57 minutes before
Perspectivas sobre las Condiciones Peligrosas del Tiempo
Servicio Nacional de Meteorologia en San Juan PR
404 AM AST domingo 10 de julio de 2022

AMZ710>745-PRZ001>013-110815-
San Juan y Vecindad-Noreste-Sureste- Este Interior-Norte Central-
Interior Central-Ponce y Vecindad-Noroeste-Oeste Interior-Mayaguez y
Vecindad-Suroeste-Culebra-Vieques-Las aguas costeras cercanas y
lejanas a la costa del Atlantico y del Caribe-
404 AM AST domingo 10 de julio de 2022

Esta perspectiva sobre las condiciones peligrosas del tiempo es para
Puerto Rico y las aguas costeras adyacentes.

.Dia Uno...Hoy y esta noche

.Tronadas...Existe el potencial de tronadas aisladas produciendo
lluvia fuerte y rafagas de viento a traves de sectores del interior,
norte y oeste.

.Inundaciones...Lluvias fuertes podrian resultar en inundaciones
urbanas y de riachuelos.

.Viento...Se esperan vientos sostenidos en exceso de 20 mph (17
nudos) a traves de las aguas locales y sectores costeros.

.Oleaje...Se espera oleaje de hasta 7 pies a traves de
las aguas mar afuera y de hasta 6 pies en el resto del area.

.Corrientes marinas...Existe un riesgo alto de corrientes marinas
para las playas del norte desde Aguadilla a Dorado. En el resto del
area, el riesgo es moderado.

.Calor...Se esperan indices de calor de 102 a 107 grados para los
municipios urbanos y costeros a traves de Puerto Rico, incluyendo
Vieques y Culebra.

.Dias dos hasta el siete...lunes a sabado

Existe el potencial de aguaceros y tronadas cada tarde, especialmente
a traves de la costa oeste de Puerto Rico. La frecuencia de aguaceros
pudiera aumentar para el proximo viernes. El riesgo de corrientes
marinas permanecera moderado durante la mayoria de la semana, aumentando
a alto el viernes. Se espera oleaje picado de hasta 6 pies, pero
pudiera aumentar a 7 pies para el viernes.

.Comunicado sobre informacion reportada por observadores...

No se anticipa la activacion de los observadores. Favor de reportar
cualquier informacion sobre vientos, olas y corrientes marinas al
Servicio Nacional de Meteorologia en San Juan mientras sigue todas
las indicaciones locales y estatales.

AMZ715-725-VIZ001-002-110815-
San Tomas, San John e Islas Adyacentes-Santa Cruz-Aguas cercanas del
Atlantico y aguas costeras adyacentes del Caribe-
404 AM AST domingo 10 de julio de 2022

Esta perspectiva sobre las condiciones peligrosas del tiempo es para
Islas Virgenes Estadounidenses y las aguas costeras adyacentes.

.Dia Uno...Hoy y esta noche

.Viento...Se esperan vientos sostenidos en exceso de 20 mph (17
nudos) a traves de las aguas locales y sectores costeros.

.Oleaje...Se espera oleaje picado de hasta 7 pies a traves de
las aguas mar afuera y de 6 en el resto del area.

.Corrientes marinas...Existe riesgo alto de corrientes marinas para
la Playa de Cramer Park en Santa Cruz y un riesgo moderado en el
resto del area.

.Dias dos hasta el siete...lunes a sabado

Un aumento en los vientos resultara en oleaje picado. El riesgo de
corrientes marinas sera moderado a traves de las playas.

.Comunicado sobre informacion reportada por observadores...

No se anticipa la activacion de los observadores. Favor de reportar
cualquier informacion sobre vientos, olas y corrientes marinas al
Servicio Nacional de Meteorologia en San Juan mientras sigue todas
las indicaciones locales y estatales.

The radar

The San Juan radar (TJUA), 30 km away, was scanning. The volume nearest the first event began at 17:28 UTC.

Open the radar archive at this moment

Event by event

6 flood, 5 flash flood, 1 lightning, 1 debris flow. Local standard time, as filed.

Flood, Bayamon

When
July 10, 1:30 PM AST to 4:00 PM AST
Where
Bayamon County, 3.05 mi NE of Bayamon to 2.97 mi NE of Bayamon
Cause
Heavy Rain
Reported by
Emergency Manager
Coordinates
18.384, -66.140

Emergency Managers reported flooding along an Aparment Complex in Ave. Lomas Verdes in Bayamon.

Flood, Bayamon

When
July 10, 1:30 PM AST to 4:00 PM AST
Where
Bayamon County, 2.88 mi N of Bayamon to 2.85 mi N of Bayamon
Cause
Heavy Rain
Reported by
Emergency Manager
Coordinates
18.391, -66.165

Emergency managers reported flooding affecting a few cars in Calle 7.

Flash Flood, Bayamon

When
July 10, 1:40 PM AST to 3:30 PM AST
Where
Bayamon County, 2.77 mi N of Bayamon to 2.68 mi N of Bayamon
Cause
Heavy Rain
Reported by
911 Call Center
Coordinates
18.390, -66.166

Reports from 911 Viper Mails indicated flooding affecting several houses.

Flash Flood, Bayamon

When
July 10, 1:47 PM AST to 3:30 PM AST
Where
Bayamon County, 3.02 mi NNE of Bayamon to 3.01 mi NNE of Bayamon
Cause
Heavy Rain
Reported by
911 Call Center
Coordinates
18.392, -66.159

Reports from Viper mails indicated flooding affecting several houses and roads.

Flash Flood, Bayamon

When
July 10, 1:54 PM AST to 3:30 PM AST
Where
Bayamon County, 3.59 mi NNW of Bayamon to 3.55 mi NNW of Bayamon
Cause
Heavy Rain
Reported by
911 Call Center
Coordinates
18.399, -66.188

Reports from Viper mails indicated flooding affecting a house in Calle 7.

Flash Flood, Bayamon

When
July 10, 1:58 PM AST to 3:30 PM AST
Where
Bayamon County, 3.51 mi NNE of Bayamon to 3.45 mi NNE of Bayamon
Cause
Heavy Rain
Reported by
911 Call Center
Coordinates
18.399, -66.158

Reports received through 911 indicated flooding affecting several cars at Roads 167 and PR-2.

Flood, Bayamon

When
July 10, 1:59 PM AST to 3:30 PM AST
Where
Bayamon County, 2.88 mi NNE of Bayamon to 2.94 mi NNE of Bayamon
Cause
Heavy Rain
Reported by
911 Call Center
Coordinates
18.389, -66.154

A report received from 911 Call Center indicated flooding along Calle 8 Bloque 19 in Bayamon.

Flash Flood, Bayamon

When
July 10, 2:02 PM AST to 3:30 PM AST
Where
Bayamon County, 3.97 mi NNW of Bayamon to 4.09 mi NNW of Bayamon
Cause
Heavy Rain
Reported by
911 Call Center
Coordinates
18.406, -66.185

Reports received from the 911 call center indicated flooding affecting the kitchen of a restaurant in Bayamon.

Flood, Toa Baja

When
July 10, 2:51 PM AST to 3:51 PM AST
Where
Toa Baja County, 1.69 mi WSW of Toa Baja to 1.45 mi SW of Toa Baja
Cause
Heavy Rain
Reported by
911 Call Center
Coordinates
18.418, -66.223

A report received through a vipermail indicated flooding affecting a residence, next to Residencial de Varon.

Flood, San Juan

When
July 10, 3:06 PM AST to 4:18 PM AST
Where
San Juan County, 2.38 mi NNW of San Juan to 2.45 mi NNW of San Juan
Cause
Heavy Rain
Reported by
911 Call Center
Coordinates
18.410, -66.068

A report from the 911 Call Center indicate flooding along Calle Columbia.

Flood, Aguadilla

When
July 10, 3:18 PM AST to 5:15 PM AST
Where
Aguadilla County, 2.1 mi SSW of Aguadilla to 2.65 mi S of Aguadilla
Cause
Heavy Rain
Reported by
Emergency Manager
Coordinates
18.441, -67.130

Emergency Managers reported flooding affecting Urb. Vista Verde in Aguadilla, with Calle 12 and Calle 13 flooded.

Lightning, Toa Baja

When
July 10, 3:29 PM AST to 4:00 PM AST
Where
Toa Baja County, 2.22 mi SSW of Toa Baja
Property damage
$5,000
Reported by
Newspaper
Coordinates
18.400, -66.212

A lightning strike impacted a tree, falling over the powerlines. This resulted in several areas without power service. The tree also hit two cars. Additionally, Highway PR-863 was closed in Pajaros, Toa Baja, around Farmacia Plaza and at the intersection of Road PR-819.

Debris Flow, Toa Baja

When
July 10, 3:39 PM AST to 4:00 PM AST
Where
Toa Baja County, 5.79 mi ESE of Toa Baja to 5.92 mi ESE of Toa Baja
Cause
Heavy Rain
Reported by
911 Call Center
Coordinates
18.390, -66.123

A landslide was reported in Calle Barcelona, Guaynabo. This affected the backyard of a residence.

What these are

Flood
Flooding that develops more slowly than a flash flood: rivers leaving their banks, or water standing over land for an extended time.
Flash Flood
Flooding that begins within six hours of the rain that causes it, or of a dam or levee failure or ice jam release, often with deadly speed.
Lightning
A lightning strike that killed, injured or caused damage.
Debris Flow
A fast-moving slurry of mud, rock and debris, usually on a slope soaked by heavy rain or stripped by a fire.

After NWS Directive 10-1605, the rules offices file Storm Data by.

The same day elsewhere

More

Every storm in Puerto Rico in 2022Every state in 2022This day in weather historyWarnings in Puerto Rico, July 2022

Sources

NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-30. Each event’s entry at NCEI: 1045065, 1045076, 1045079, 1045081, 1045082, 1045088, 1045089, 1045090, 1045091, 1045092, 1045093, 1045095, 1045194.