Flash Flood Warning 69, NWS JSJ

870 
WGCA72 TJSJ 091312
FFSSJU

Flash Flood Statement
National Weather Service San Juan PR
912 AM AST Thu Nov 9 2023

PRC069-095-109-151-091600-
/O.CON.TJSJ.FF.W.0069.000000T0000Z-231109T1600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Humacao PR-Maunabo PR-Patillas PR-Yabucoa PR-
912 AM AST Thu Nov 9 2023

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL NOON AST TODAY FOR 
HUMACAO, MAUNABO, PATILLAS AND YABUCOA COUNTIES...

At 912 AM AST, Doppler radar indicated thunderstorms producing heavy 
rain across the warned area. Between 1 and 4 inches of rain have 
fallen. Additional rainfall amounts of 1 to 2 inches are possible in 
the warned area. Flash flooding is ongoing, particularly in Maunabo, 
where emergency managers reported that Rio Maunabo is out of its 
banks, affecting road PR-759 in Sector Tumbao of Bo Palo Seco near 
Puente La Garona. This road is impassable.

HAZARD...Life threatening flash flooding. Thunderstorms producing
         flash flooding.

SOURCE...Radar.

IMPACT...Life threatening flash flooding of creeks and streams,
         urban areas, highways, streets and underpasses.

Some locations that will experience flash flooding include...
  Yabucoa, Maunabo, Humacao, Patillas, Emajagua, Martorell, Playita, 
  La Fermina, Palmas, Anton Ruiz, Punta Santiago, Rosa Sanchez, El 
  Negro, Comunas, Palo Seco, Candelero Arriba, Lamboglia, Bajandas 
  and Yaurel.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood 
deaths occur in vehicles.

Please report observed flooding to local emergency services or law 
enforcement and request they pass this information to the National 
Weather Service when you can do so safely.

&&

LAT...LON 1804 6609 1806 6609 1811 6605 1808 6601
      1809 6598 1809 6594 1812 6593 1812 6588
      1821 6582 1819 6576 1818 6575 1818 6574
      1813 6578 1814 6582 1812 6578 1807 6579
      1799 6588 1797 6598 1798 6602 1804 6605

FLASH FLOOD...RADAR INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE

$$

ICP

584 
WGCA72 TJSJ 091453
FFSSJU

Flash Flood Statement
National Weather Service San Juan PR
1053 AM AST Thu Nov 9 2023

PRC069-095-109-151-091503-
/O.CAN.TJSJ.FF.W.0069.000000T0000Z-231109T1600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Humacao PR-Maunabo PR-Patillas PR-Yabucoa PR-
1053 AM AST Thu Nov 9 2023

...FLASH FLOOD WARNING FOR HUMACAO, MAUNABO, PATILLAS AND YABUCOA 
COUNTIES HAS BEEN REPLACED WITH A FLOOD ADVISORY...

LAT...LON 1804 6609 1806 6609 1811 6605 1808 6601
      1809 6598 1809 6594 1812 6593 1812 6588
      1821 6582 1819 6576 1818 6575 1818 6574
      1813 6578 1814 6582 1812 6578 1807 6579
      1799 6588 1797 6598 1798 6602 1804 6605

$$

ICP

Area Forecast Discussion
National Weather Service San Juan PR
446 AM AST Thu Nov 9 2023

.SYNOPSIS...
Expect a wet and unsettled weather pattern throughout the weekend
as plenty of moisture interacts with a short-wave trough. Due to
saturated soils, there is an increased potential for urban, river
and life-threatening flash flooding, as well as mudslides and
rockfall. A drying pattern will start late in the weekend into
next week. Breezy conditions are expected later today, Small Craft
Should Exercise Caution. There is a moderate risk of rip currents
for the north oriented beaches of Puerto Rico from Rincon to
Ceiba, as well as for most of Culebra's beaches, the northern and
western beaches of St. Thomas and the easternmost beaches of St.
Croix.

&&

.SHORT TERM...Today through Saturday...

A very active night unfolded, yielding several Flood Advisories and
Flash Flooding for municipalities across northern Puerto Rico, with
the latter issued for Bayamon, Catano, Guaynabo, and Toa Baja. Until
4 AM AST, Doppler radar estimated between 1-3 inches of rain fell,
with isolated higher amounts, during that time across that area.
Convective activity continued developing and organizing throughout
the night over the Caribbean waters and eastern/northeastern Puerto
Rico. Low-level convergence along with divergence aloft prevails
over the region. Therefore, expect shower and thunderstorm
development to persist through the morning hours, with an advective
pattern impacting the eastern third of Puerto Rico and lesser
islands.

The polar trough that has been influencing the local weather pattern
will continue lifting north. However, a short-wave trough is
currently developing aloft stemming from the aforementioned polar
trough. Model guidance suggests this short-wave trough will
strengthen as it meanders over the local islands through at least
Saturday. This feature will maintain increased vorticity aloft, 500
mb temperatures between -8 to -7 degrees Celsius, and near normal to
above normal lapse rates. Additionally, 250 mb heights and 1000-
500mb thicknesses will fall during this time promoting favorable
weather conditions for deep convective development. This favorable
dynamic setup will combine with plenty of tropical moisture. The
latest imagery from the Polar Blended-Percent of Normal Total
Precipitable water (TPW) indicates between 140%-150% of above TPW
spread between Puerto Rico and the northeastern Leeward Islands.
Precipitable water values above 2.0 inches will prevail for the
duration of the short-term forecast. Both ECMWF and GFS Galvez-
Davison Index indicate substantial low-level moisture convergence
with isolated to scattered thunderstorms capable of producing heavy
rain every day.

Therefore, expect a wet and unsettled weather pattern through the
weekend as plenty of moisture interacts with the short-wave trough.
Due to saturated soils, there is an increased potential for urban,
river and life-threatening flash flooding, as well as mudslides and
rockfall. Please continue to monitor for any advisories or warnings
issued by our office as this event unfolds.

&&

.LONG TERM...Sunday through Thursday...

Current model guidance indicates a drying pattern for the long term
period. To start the next week precipitable water (PWAT) values will
still be at around 1.8 to 2 inches, at the higher end of normal
values to slightly above normal values for this time of the year.
However, drier air will filter in late Sunday and during the
workweek, with only patches of low-level moisture pushing PWAT
values to around 1.75 inches. Low concentrations of Saharan Dust
will also filter into the area through at least Tuesday. A mid-to
upper-level ridge over the central Caribbean will build throughout
the period, promoting drier air aloft. At surface level a high
pressure system will build across the western and central Atlantic
into early next week, promoting stronger trade winds across the
northeastern Caribbean. Uncertainty remains in the forecast due to
discrepancies between the GFS and the ECMWF. The GFS develops a
surface low across the western Caribbean which influences moisture
content and wind direction across the local islands late in the
period. On the other hand the ECMWF suggest drier air aloft. The
forecast remains leaning towards climatology for the late long
term period, please stay tuned for future updates. Passing shower
activity is forecast across eastern Puerto Rico and the USVI
during the night and early morning hours. Afternoon shower and
thunderstorm activity is forecast mainly for western Puerto Rico
each day, due sea breeze convergence and local effects.

&&

.AVIATION...
An active weather pattern will persist through the forecast
period. Sct-Num SHRA/SCT-TSRA will affect the local flying area
today. TEMPO MVFR/IFR conds and widespread mtn obscurations can be
expected. Variable sfc winds from up to 10kt until 09/14Z then 10
to 15 kt thereafter with sea breeze variations. Locally higher
gusts near/in TSRA throughout the period.

&&

.MARINE...
CARICOOS buoys indicate around 3 foot wave heights across
nearshore waters. Buoys near San Juan, Arecibo and Rincon indicate
a minor swell with periods of 11-13 seconds. This swell will
slowly dissipate throughout the rest of the week. A developing
surface ridge in the western Atlantic will bring moderate to
locally fresh easterly winds across the local waters starting
today. Small Craft Should Exercise Caution. These choppy
conditions are expected through the weekend. There is a moderate
risk of rip currents for the north oriented beaches of Puerto
Rico from Rincon to Ceiba, as well as for most of Culebra's
beaches, the northern and western beaches of St. Thomas and the
easternmost beaches of St. Croix.

&&

.SJU WATCHES/WARNINGS/ADVISORIES...
PR...None.
VI...None.
AM...None.

&&

CVB,MRR,ICP

Perspectiva sobre las Condiciones Peligrosas del Tiempo
Servicio Nacional de Meteorología San Juan PR
427 AM AST jueves 9 de noviembre de 2023

AMZ711>745-PRZ001>013-100830-
San Juan y Vecindad-Noreste-Sureste-Este Interior-
Norte Central-Central Interior-Ponce y Vecindad-Noroeste-
Oeste Interior-Mayagüez y Vecindad-Suroeste-Culebra-Vieques-
Aguas cercanas y fuera de la costa del Atlántico y del Caribe-
427 AM AST jueves 9 de noviembre de 2023

Esta perspectiva sobre las condiciones peligrosas del tiempo es para
sectores de Puerto Rico.

.DÍA UNO...Hoy y esta noche

.Rayos...Tormentas eléctricas de aisladas a dispersas posibles. Esté
atento a las tormentas eléctricas en  su área y esté preparado para
buscar refugio.

.Lluvia Excesiva...Inundaciones en áreas urbanas, calles,
riachuelos y canales. Inundaciones repentinas aisladas posibles.

.Calor Excesivo...Índices de calor de 102 a 107 grados a través de
las áreas urbanas y costeras.  Agotamiento por calor posible con una
exposición prolongada.

.Condiciones Marítimas...Las embarcaciones pequeñas deben ejercer
precaución a través de las aguas del noroeste del Atlántico y el
Pasaje de Mona.

.Corrientes Marinas...Las corrientes marinas que amenacen la vida
son posibles en la zona de oleaje particularmente a lo largo del
norte, este y oeste, Vieques y Culebra.

. DÍAS DOS A SIETE...Viernes a miércoles

Se espera un riesgo elevado de inundaciones urbanas y de riachuelos
cada día hasta el viernes, y permanecerá elevado para el oeste cada
día. Se esperan índices de calor de 102 a 107 cada tarde para las
áreas urbanas y costeras. Los vientos aumentarán para el final de
la semana laboral. El riesgo de corrientes marinas permanecerá
moderado.  Las condiciones marinas se deteriorarán en la última
parte de la semana hasta el fin de semana.

. COMUNICADO SOBRE INFORMACIÓN REPORTADA POR OBSERVADORES...

Se les exhorta a los observadores a reportar.  Favor de reportar
cualquier información sobre inundaciones, vientos, olas y corrientes
marinas al Servicio Nacional de Meteorología en San Juan.

AMZ716-726-VIZ001-002-100830-
San Thomas San John e islas adyacentes-Santa Cruz-
Aguas cercanas a la costa del Atlántico y aguas costeras adyacentes
del Caribe-
427 AM AST jueves 9 de noviembre de 2023

Esta Perspectiva sobre las Condiciones Peligrosas del Tiempo es para
sectores de las Islas Vírgenes Americanas.

.DÍA UNO...Hoy y esta noche

.Rayos...Tormentas eléctricas aisladas a dispersas posibles.  Esté
atento a las tormentas eléctricas en  su área y esté preparado para
buscar refugio.

.Lluvia Excesiva...Acumulación de agua en las carreteras y áreas
mal drenadas.  Las inundaciones de riachuelos urbanos y pequeños son
posibles.

.Calor Excesivo...Índices de calor de 102 a 107 grados a través de
las islas.  Agotamiento por calor posible con una exposición
prolongada.

.Corrientes Marinas...Las corrientes marinas que amenacen la vida
son posibles en la zona de oleaje de todas las islas.

.DÍAS DOS A SIETE...Viernes a miércoles

Se espera un riesgo elevado de inundaciones urbanas y de riachuelos
cada día hasta el viernes. Se esperan índices de calor de 102 a 107
cada tarde para las áreas urbanas y costeras. Los vientos
aumentarán para el final de la semana laboral. El riesgo de
corrientes marinas permanecerá  moderado.  Las condiciones marinas
se deteriorarán en la última parte de la semana hasta el fin de
semana.

. COMUNICADO SOBRE INFORMACIÓN REPORTADA POR OBSERVADORES...

Se les exhorta a los observadores a reportar.  Favor de reportar
cualquier información sobre inundaciones, vientos, olas y corrientes
marinas al Servicio Nacional de Meteorología en San Juan.

Preliminary Local Storm Report
National Weather Service San Juan PR
400 AM AST Thu Nov 9 2023

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0240 AM     Flash Flood      1 WSW Candelaria Arenas 18.42N 66.23W
11/09/2023                   Toa Baja           PR   Emergency Mngr

            Toa Baja EM reported a car trapped in flood
            waters along road PR-865 in Villa Clemente,
            near American Gas Station. EM and Fire
            Department tow truck removed the car from
            the area. No one was injured.

&&

ICP

Preliminary Local Storm Report
National Weather Service San Juan PR
438 AM AST Thu Nov 9 2023

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0420 AM     Flash Flood      2 ESE Catano            18.43N 66.11W
11/09/2023                   Guaynabo           PR   Emergency Mngr

            Emergency managers (Control) reported Ave.
            Ponce de Leon in Bo Amelia, Guaynabo,
            impassable due to flash flooding.

&&

ICP

Preliminary Local Storm Report
National Weather Service San Juan PR
446 AM AST Thu Nov 9 2023

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0430 AM     Flash Flood      Sabana Seca             18.43N 66.19W
11/09/2023                   Toa Baja           PR   Emergency Mngr

            Emergency Managers (Control) and 911 Call
            Center reported road PR-867 around km 0.4
            impassable due to flash flood waters near
            Sector Cuatro Cuerdas, Bo Sabana Seca, Toa
            Baja.

&&

ICP