Alert archive / Puerto Rico / Flash Flood Warnings in 2017

Flash Flood Warning 105, NWS JSJ

September 21, 2017

NWS JSJ issued this flash flood warning at Sep 21, 2017, 3:50 AM CDT. It was in force for 4 hr. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Sep 21, 2017, 3:50 AM CDT (08:50 UTC)
Expired
Sep 21, 2017, 8:00 AM CDT
In force
4 hr
Issued by
NWS JSJ
Area
Storm-based polygon
Flood severity
None

Did it verify

Not verified. The Iowa Environmental Mesonet's Cow found no qualifying storm report inside this flash flood warning while it was in force. That is not proof nothing happened: reports are thin where few people live.

Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.

The text

As transmitted.

078 
WGCA52 TJSJ 210850
FFWSJU
PRC001-023-055-059-079-093-111-113-121-125-153-211300-
/O.NEW.TJSJ.FF.W.0105.170921T0850Z-170921T1300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service San Juan PR
Issued by National Weather Service Miami FL
450 AM AST THU SEP 21 2017

The National Weather Service in San Juan has issued a

* Flash Flood Warning for...
  Sabana Grande Municipality in Puerto Rico...
  Guayanilla Municipality in Puerto Rico...
  Lajas Municipality in Puerto Rico...
  Cabo Rojo Municipality in Puerto Rico...
  Southeastern Maricao Municipality in Puerto Rico...
  Guanica Municipality in Puerto Rico...
  West central Ponce Municipality in Puerto Rico...
  Southern San German Municipality in Puerto Rico...
  Southwestern Adjuntas Municipality in Puerto Rico...
  Yauco Municipality in Puerto Rico...
  Penuelas Municipality in Puerto Rico...

* Until 900 AM AST

* At 449 AM AST, satellite estimates indicated thunderstorms
  producing heavy rain across the warned area. Flash flooding is
  ongoing and expected to continue.

* Some locations that will experience flooding include...
  Yauco, Guayanilla, Guanica, Sabana Grande, San German, Lajas,
  Penuelas, Cabo Rojo, Puerto Real, Palomas, Santo Domingo, Tallaboa
  Alta, Monte Grande, Magas Arriba, Liborio Negron Torres, Sabana
  Eneas, Tallaboa, Indios, Palmarejo and Betances.

Excessive rainfall over the warned area will cause mud slides near
steep terrain. The mud slide can consist of rock, mud, vegetation and
other loose materials.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Be especially cautious at night when it is harder to recognize the
dangers of flooding.

A Flash Flood Warning means that flooding is imminent or occurring.
If you are in the warned area move to higher ground immediately.
Residents living along streams and creeks should take immediate
precautions to protect life and property.

&&

LAT...LON 1791 6698 1795 6702 1794 6706 1794 6717
      1792 6719 1794 6723 1799 6723 1801 6720
      1804 6723 1808 6721 1809 6700 1814 6697
      1814 6686 1816 6682 1811 6668 1794 6668
      1797 6671 1797 6678 1791 6692

$$

JDW
1 follow-up statement
909 
WGCA72 TJSJ 211047
FFSSJU

Flash Flood Statement
National Weather Service San Juan PR
Issued by National Weather Service Miami FL
647 AM AST THU SEP 21 2017

PRC001-023-055-059-079-093-111-113-121-125-153-211300-
/O.CON.TJSJ.FF.W.0105.000000T0000Z-170921T1300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Sabana Grande PR-Guayanilla PR-Lajas PR-Cabo Rojo PR-Maricao PR-
Guanica PR-Ponce PR-San German PR-Adjuntas PR-Yauco PR-Penuelas PR-
647 AM AST THU SEP 21 2017

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 900 AM AST FOR
SABANA GRANDE...GUAYANILLA...LAJAS...CABO ROJO...SOUTHEASTERN
MARICAO...GUANICA...WEST CENTRAL PONCE...SOUTHERN SAN GERMAN...
SOUTHWESTERN ADJUNTAS...YAUCO AND PENUELAS MUNICIPALITIES...

At 646 AM AST, satellite estimates indicated heavy rain over the
warned area.  Flash flooding is already occurring.

Excessive rainfall over the warned area will cause mud slides near
steep terrain. The mud slide can consist of rock, mud, vegetation and
other loose materials.

Some locations that will experience flooding include...
Yauco, Guayanilla, Guanica, Sabana Grande, San German, Lajas,
Penuelas, Cabo Rojo, Puerto Real, Palomas, Santo Domingo, Tallaboa
Alta, Monte Grande, Magas Arriba, Liborio Negron Torres, Sabana
Eneas, Tallaboa, Indios, Palmarejo and Betances.

Additional rainfall amounts of 2 to 5 inches are possible in the 
warned area.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Be especially cautious at night when it is harder to recognize the
dangers of flooding.

A Flash Flood Warning means that flooding is imminent or occurring.
If you are in the warned area move to higher ground immediately.
Residents living along streams and creeks should take immediate
precautions to protect life and property.

&&

LAT...LON 1791 6698 1795 6702 1794 6706 1794 6717
      1792 6719 1794 6723 1799 6723 1801 6720
      1804 6723 1808 6721 1809 6700 1814 6697
      1814 6686 1816 6682 1811 6668 1794 6668
      1797 6671 1797 6678 1791 6692

$$

RAG

What forecasters said that day

The local office's own words before this flash flood warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS JSJ wrote its last area forecast discussion before this flash flood warning went out at Sep 21, 12:36 AM CDT, 3 hours 14 minutes earlier.

Area forecast discussion, Sep 21, 12:36 AM CDT, 3 hours 14 minutes before
Area Forecast Discussion
National Weather Service San Juan PR
Issued by National Weather Service MIAMI FL
136 AM AST Thu Sep 21 2017

PREV DISCUSSION... /issued 1209 PM AST Wed Sep 20 2017/

UPDATE...Major Hurricane Maria producing widespread and dangerous
flash flooding across Puerto Rico. Major flooding occurring along
the Rio Grande de Loiza, Rio Grande de Manati and La Plata basins.
Dangerous winds will continue through this evening across mainland
PR. The center of Maria should be exiting the north coast of
Puerto Rico shortly and the strongest hurricane storm force winds
should spread along the north central and northwest portions of
Puerto Rico through late this afternoon. Although, tropical storm
force winds could diminish this evening across the USVI and
portions of southeastern PR...outer bands of Maria with strong
thunderstorms will move across these areas. Currently, scattered
thunderstorms with frequent lighting are being observed along the
eastern coastal waters of the USVI.

&&

.AVIATION...
Hurricane Maria will gradually pull away to the northeast through
Thursday with conditions slowly improving. Still widespread MVFR
with IFR/LIFR likely in heavier showers, especially across the
Puerto Rico terminals. Winds gusting to 40 kts at times will ease
and much lighter wind speeds expected by Thursday evening. USVI
terminals will see conditions improving more rapidly with more
scattered showers possible through the period. AMD NOT SKED
remains for all terminals, continue to check with authorities for
airport closures.

&&

MARINE...Tropical storm force winds will likely continue across
the Caribbean waters through this afternoon and Hurricane force
winds across the Atlantic waters through late tonight. There is no
chance of a successful passage through this storm.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU  91  77  92  77 /  40  20  20  30
STT  85  81  86  80 /  80  80 100  50

&&

.SJU WATCHES/WARNINGS/ADVISORIES...
PR...Flash Flood Watch through Friday afternoon for Central Interior-
     Culebra-Eastern Interior-Mayaguez and Vicinity-North
     Central-Northeast-Northwest-Ponce and Vicinity-San Juan and
     Vicinity-Southeast-Southwest-Vieques-Western Interior.

VI...Flash Flood Watch through Friday afternoon for St Croix-
     St.Thomas...St. John...and Adjacent Islands.

     Small Craft Advisory until 2 PM AST this afternoon for
     St.Thomas...St. John...and Adjacent Islands.

AM...Flash Flood Watch through Friday afternoon for Coastal Waters OF
     Southwestern Puerto Rico out 10 NM-Coastal Waters of
     Northern USVI and Culebra out 10 NM-Coastal Waters of
     Southern Puerto Rico out 10 NM-Coastal Waters of Southern
     USVI Vieques and Eastern Puerto Rico out 10 NM.

     Small Craft Advisory until 2 PM AST this afternoon for Anegada
     Passage Southward to 17N-Caribbean Waters of Puerto Rico
     from 10 NM to 17N-Coastal Waters of Northern USVI and
     Culebra out 10 NM-Coastal Waters of Southern Puerto Rico
     out 10 NM-Coastal Waters of Southern USVI Vieques and
     Eastern Puerto Rico out 10 NM.

     Hurricane Warning for Atlantic Waters of Puerto Rico and USVI
     from 10 NM to 19.5N-Coastal Waters OF Northwestern Puerto
     Rico out 10 NM-Coastal Waters OF Southwestern Puerto Rico
     out 10 NM-Coastal Waters of Northern Puerto Rico out 10 NM-
     Mona Passage Southward to 17N.

&&

SHORT TERM...99
LONG TERM....99
Hazardous weather outlook, Sep 20, 5:22 AM CDT, 22 hours 28 minutes before
Perspectivas sobre condiciones peligrosas del tiempo
Servicio Nacional de Meteorologia San Juan PR
610 AM AST miercoles 20 de septiembre de 2017

AMZ710>745-PRZ001>013-201115-
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 lejanas a la costa del Atlantico y Caribe-
610 AM AST miercoles 20 de septiembre de 2017

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

...Un Aviso de Huracan esta en efecto...

Un Aviso de Huracan significa que condiciones de huracan es esperan
en algun sector dentro del area bajo aviso. Preparaciones para
protejer vida y propiedad deberan ser completados lo mas pronto
posible.

...Un Aviso de Huracan esta en efecto...

AMZ715-725-VIZ001-002-201115-
San Tomas, San John e Islas Adyacentes-
Santa Cruz-Aguas cercanas del Atlantico y aguas costeras adyacentes
del Caribe-
610 AM AST miercoles 20 de septiembre de 2017

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

...Un Aviso de Huracan esta en efecto...

Un Aviso de Huracan significa que condiciones de huracan es esperan
en algun sector dentro del area bajo aviso. Preparaciones para
protejer vida y propiedad deberan ser completados lo mas pronto
posible.

...Un Aviso de Huracan esta en efecto...

The office that day

Everything else NWS JSJ issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Sep 20, 7:05 PM CDTFlash Flood WarningJSJ4 hr
Sep 20, 7:26 PM CDTFlash Flood WarningJSJ4 hr
Sep 20, 7:30 PM CDTFlash Flood WarningJSJ4 hr
Sep 20, 7:32 PM CDTFlash Flood WarningJSJ4 hr
Sep 20, 7:59 PM CDTFlash Flood WarningJSJ4 hr
Sep 20, 9:25 PM CDTFlash Flood WarningJSJ5 hr
Sep 20, 9:29 PM CDTFlash Flood WarningJSJ5 hr
Sep 20, 9:42 PM CDTFlash Flood WarningJSJ5 hr
Sep 20, 10:40 PM CDTFlash Flood Warning EmergencyJSJ3 hr
Sep 20, 10:43 PM CDTFlash Flood WarningJSJ9 hr
Sep 20, 10:45 PM CDTFlash Flood WarningJSJ5 hr
Sep 20, 10:52 PM CDTFlash Flood WarningJSJ5 hr
Sep 20, 10:56 PM CDTFlash Flood WarningJSJ5 hr
Sep 20, 10:59 PM CDTSmall Craft AdvisoryJSJ52 hr
Sep 20, 11:03 PM CDTFlash Flood WarningJSJ5 hr
Sep 20, 11:20 PM CDTFlash Flood WarningJSJ5 hr
Sep 21, 1:39 AM CDTFlash Flood WarningJSJ7 hr
Sep 21, 2:20 AM CDTFlash Flood WarningJSJ5 hr
Sep 21, 2:25 AM CDTFlash Flood WarningJSJ5 hr
Sep 21, 2:27 AM CDTFlash Flood WarningJSJ5 hr
Sep 21, 3:35 AM CDTFlash Flood WarningJSJ3 hr
Sep 21, 3:45 AM CDTFlash Flood WarningJSJ4 hr
Sep 21, 3:53 AM CDTFlash Flood WarningJSJ3 hr
Sep 21, 4:09 AM CDTFlash Flood WarningJSJ3 hr
Sep 21, 6:54 AM CDTFlash Flood WarningJSJ7 hr
Sep 21, 7:00 AM CDTFlash Flood Warning EmergencyJSJ7 hr
Sep 21, 7:58 AM CDTAreal Flood WarningJSJ6 hr
Sep 21, 8:30 AM CDTSpecial Marine WarningJSJ2 hr
Sep 21, 10:20 AM CDTTropical Storm WarningJSJ5 hr
Sep 21, 10:27 AM CDTSpecial Marine WarningJSJ63 min
Sep 21, 11:30 AM CDTSpecial Marine WarningJSJ90 min
Sep 21, 12:55 PM CDTSpecial Marine WarningJSJ2 hr
Sep 21, 1:55 PM CDTFlash Flood WarningJSJ3 hr
Sep 21, 1:57 PM CDTAreal Flood WarningJSJ6 hr
Sep 21, 2:01 PM CDTAreal Flood WarningJSJ6 hr
Sep 21, 4:57 PM CDTAreal Flood WarningJSJ3 hr

Nearby

Flash Flood Warnings in Puerto Rico, 2017Every flash flood warning in 2017

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text.