A cold front moved across the area, generating areas of showers. With a very light northerly flow, showers developed across the San Juan and Carolina area and moved very slowly, generating significant urban flooding.
Every event with a place to put it. Tap one for its entry below.
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.
The episode as NWS SJU wrote it up.
A cold front moved across the area, generating areas of showers. With a very light northerly flow, showers developed across the San Juan and Carolina area and moved very slowly, generating significant urban flooding.
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 Feb 24, 4:57 AM AST, 4 hours 31 minutes earlier.
Area Forecast Discussion
National Weather Service San Juan PR
457 AM AST Mon Feb 24 2020
.SYNOPSIS...
A weak frontal boundary across the Atlantic waters is causing
showers across the local waters. The frontal boundary will
continue to produce showers across the local waters today; this
activity will then spread inland during the afternoon. High
pressure will move over the region by mid-week and hold through
Sunday. The high pressure will cause relatively tranquil weather,
however an isolated showers can't be ruled out during the
afternoon. Sunday, another frontal boundary is expected to move
close to the area, and bring an end to the relatively tranquil
weather for Puerto Rio and the U.S. Virgin Islands.
&&
.SHORT TERM...Today through Wednesday...
A frontal boundary is providing plenty of moisture across the
islands. This front will linger and dissipate over the region
through the short term. Although there is high uncertainty about
where is going to be observed the rain activity, the available
moisture will result in cloudy skies and rainy conditions across
many parts of the islands. However, this activity should remain
mainly over the waters, and from the northwest to northeast portions
of Puerto Rico and the northern U.S. Virgin Islands. Shower activity
will spread across the interior and southern sections by mid-morning
into the afternoon hours. The less potential to observe rain
activity is in St Croix. Therefore, we are forecasting fair weather
for them. As the day progresses, the available moisture in
combination with surface convergence and mountain effects, will aid
in the development of afternoon showers over the interior, west and
northern half of PR. Under light steering winds periods of prolonged
moderate to locally heavy rains will lead to urban and small stream
flooding across portions of the islands.
As the aforementioned frontal boundary dissipate, a surface high
pressure which is forecast to move eastward into the Central
Atlantic Ocean will promote an advective pattern by Wednesday.
Therefore, winds will return from the east and the typical trade
wind showers.
&&
.LONG TERM...Thursday through Tuesday...
Relatively stable weather is prog to prevail through most of the
long-term period as a result of ridging at the surface and aloft.
As the ridges hold across the area, they will also transport a
drier air across Puerto Rico and the U.S. Virgin Islands, and
increase the trade wind cap through Saturday Afternoon. However,
moisture confined between 1000 to 700 MB, local, and diurnal
effects could produce a few showers during the afternoon. Showers
that do develop will be short-lived and produce light rainfall
amounts.
Saturday will be a transition day as a frontal boundary across the
western Atlantic begins to weaken the surface and mid-level
ridge, which will allow moisture to slide underneath the ridges.
The moisture increase will aid in the development of showers
during the early morning across eastern and northern Puerto Rico,
and the U.S. Virgin Islands. Then showers across the western and
interior during the afternoon. Sunday, a short-wave, and jet-steak
are forecast to round the best of the trough mentioned above. As
a result, the frontal boundary will continue to move south and
near the local waters late Sunday night into Monday morning.
The GFS shows the frontal boundary draped over Puerto Rico by Monday
afternoon, and lingering through Tuesday morning. Additionally,
the GFS shows precipitable water values ranging from 1.5 to 2.0
inches Monday through early Tuesday morning. The moisture
increase, low-level convergence, adequate instability, and
northerly wind flow will aid in the development of scattered to
numerous showers Monday through Tuesday morning.
By Tuesday afternoon, current guidance shows the frontal boundary south
of Puerto Rico, and precipitable water values decreasing
throughout the day. Nevertheless, lingering moisture will combine
with local and diurnal effects to induce scattered to isolated
showers during the afternoon. At this time, thunderstorm
development looks bleak due to warm 500 MB temperatures and
limited upper-level divergence over Puerto Rico and the U.S.
Virgin Islands. However, a few isolated thunderstorms may develop
across the Atlantic, and Caribbean waters were current guidance
has the highest upper-level divergence.
&&
.AVIATION...
SHRA/-SHRA will affect the terminals of N/W-PR/St Thomas
as a frontal boundary stall near the region. Therefore, expects
ceilings btwn FL030-FL070 at JBQ/JMZ/JSJ/IST through much of the
fcst period. SHRA will slowly move into the interior and S-PR after
24/15z, impacting JPS. ISX/NCM/KPK can expect tranquil weather
conditions. Winds will continue light and VRB, increasing around 10
knots with a NE component and sea breeze variations after 24/13z.
S/SW component.
&&
.MARINE...
A northerly swell and winds up to 20 kts will cause hazardous
seas through the middle of the week. There is a small craft
advisory in effect for the Atlantic waters, Mona Passage, Anegada
Passage and the northern near-shore waters of Puerto Rico.
Additionally, there is a high risk of rip currents for the
northern, eastern and western beaches of Puerto Rico. Also, there
is a high risk of rip currents for Saint Thomas, Saint John and
the beaches of Culebra. Winds will be from the northeast to east-
northeast ranging from 10 to 20 kts.
&&
.PRELIMINARY POINT TEMPS/POPS...
SJU 82 73 82 73 / 70 40 60 50
STT 83 73 83 74 / 10 50 50 20
&&
.SJU WATCHES/WARNINGS/ADVISORIES...
PR...High Rip Current Risk through late Tuesday night for Culebra-
Mayaguez and Vicinity-North Central-Northeast-Northwest-San
Juan and Vicinity-Southeast.
High Rip Current Risk until 6 AM AST early this morning for
Southwest.
VI...High Rip Current Risk through late Tuesday night for
St.Thomas...St. John...and Adjacent Islands.
AM...Small Craft Advisory until 6 AM AST Wednesday for Coastal Waters
of Northern Puerto Rico out 10 NM.
Small Craft Advisory until 2 AM AST Thursday for Atlantic Waters
of Puerto Rico and USVI from 10 NM to 19.5N.
Small Craft Advisory until 8 PM AST Tuesday for Coastal Waters
OF Northwestern Puerto Rico out 10 NM-Coastal Waters of
Northern USVI and Culebra out 10 NM.
Small Craft Advisory from 8 AM this morning to 8 PM AST this
evening for Anegada Passage Southward to 17N.
Small Craft Advisory until 8 PM AST this evening for Coastal
Waters OF Southwestern Puerto Rico out 10 NM.
Small Craft Advisory until 2 AM AST Wednesday for Mona Passage
Southward to 17N.
&&
SHORT TERM...CAM
LONG TERM....TW
PUBLIC DESK...CAMPerspectivas sobre Condiciones Peligrosas del Tiempo Servicio Nacional de Meteorologia San Juan PR 908 AM AST lunes 24 de febrero de 2020 AMZ710>745-PRZ001>013-251000- San Juan y Vecindad-Noreste-Sureste-Este Interior-Norte Central- Interior Central-Ponce y Vecindad-Noroeste-Oeste Interior-Mayaguez y Vecindad-Suroeste-Culebra-Vieques-Aguas cercanas y mar afuera del Atlantico y Caribe- 908 AM AST lunes 24 de febrero de 2020 Esta perspectiva sobre las condiciones peligrosas del tiempo es para Puerto Rico y las aguas costeras del Atlantico. .Dia Uno...Hoy y esta noche .Inundaciones...Lluvias fuertes pudieran resultar en inundaciones urbanas y de riachuelos. .Viento...Vientos sostenidos en exceso a las 20 mph a traves de las aguas del Atlantico, el Pasaje de la Mona y sectores de la costa norte de Puerto Rico. .Oleaje...Se espera oleaje vigoroso de hasta 10 pies a traves de las aguas del Atlantico y los Pasajes del Caribe. Se esperan olas rompientes de entre 10 a 14 pies a traves de la costa norte de Puerto Rico y Culebra. .Corrientes marinas...Existe riesgo alto de corrientes marinas para las costas desde el noroeste al noreste de Puerto Rico y Culebra. .Dias dos hasta el siete...martes a domingo Una marejada del noroeste creara condiciones maritimas peligrosas con riesgo alto de corrientes marinas hata al menos el miercoles. El potencial de aguaceros se mantendra alto hasta al menos el martes por el paso de los remanentes de un frente frio. Inundaciones urbanas y de riachuelos son posibles a traves de sectores de Puerto Rico con la lluvia mas fuerte. .Comunicado sobre informacion reportada por observadores... No se anticipa activacion amplia de observadores. Sin embargo, se les exhorta a los observadores individuales a reportar corrientes marinas al Servicio Nacional de Meteorologia en San Juan. AMZ715-725-VIZ001-002-251000- San Tomas, San John y Islas Adyacentes-Santa Cruz- Aguas cercanas del Atlantico y aguas costeras adyacentes del Caribe- 908 AM AST lunes 24 de febrero de 2020 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...Vientos sostenidos en exceso a las 20 mph a traves de las aguas del Atlantico y el Pasaje de la Mona. .Oleaje...Se espera oleaje vigoroso de hasta 10 pies a traves de las aguas del Atlantico y los Pasajes del Caribe. Se esperan olas rompientes peligrosas entre 10 a 14 pies a traves de la costa norte de San Thomas y San John. .Corrientes marinas...Existe riesgo alto de corrientes marinas para las playas del norte de San Thomas. .Dias dos hasta el siete...martes a domingo Una marejada del noroeste creara condiciones maritimas peligrosas con riesgo alto de corrientes marinas hata al menos el miercoles. El potencial de aguaceros se mantendra alto hasta al menos el martes por el paso de los remanentes de un frente frio. .Comunicado sobre informacion reportada por observadores... No se anticipa activacion amplia de observadores. Sin embargo, se les exhorta a los observadores individuales a reportar corrientes marinas al Servicio Nacional de Meteorologia en San Juan.
The San Juan radar (TJUA), 35 km away, was scanning. The volume nearest the first event began at 13:26 UTC.
8 flash flood, 2 flood. Local standard time, as filed.
Emergency manager reported flooding at Calle Caracas with intersection with Calle Rexach.
Emergency managers reported flooding at Calle Betances in Santurce.
Calle Marte in Isla Verde was impassable due to significant flooding.
Calle Mar del Norte in the urbanization of Villamar was impassable due to significant flooding.
Avenida Roberto Clemente intersection with Avenida Fragoso was impassable due to significant flooding.
Road PR-874 was impassable due to significant flooding.
Road Via 31 in Villa Fontana was impassable due to significant flooding.
Emergency managers reported that water was making its way into Jose Severo Quinones School.
Emergency managers reported significant flooding occurring at Avenida Iturregui. Road was impassable.
Emergency managers reported that La Baldorioty de Castro was impassable due to significant flooding.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Puerto Rico in 2020Every state in 2020This day in weather historyWarnings in Puerto Rico, February 2020
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 2026-09-24. Each event’s entry at NCEI: 877658, 877659, 877660, 877661, 877662, 877663, 877664, 877665, 877666, 877667.