Alert archive / Puerto Rico / Flash Flood Warnings in 2021

Flash Flood Warning 17, NWS JSJ

October 20, 2021

NWS JSJ issued this flash flood warning at Oct 20, 2021, 11:19 AM CDT. It was in force for 3 hr. 4 reports came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued: Oct 20, 2021, 11:19 AM CDT (16:19 UTC)
Expired: Oct 20, 2021, 2:21 PM CDT
In force: 3 hr
Issued by: NWS JSJ
Area: Storm-based polygon
Flood severity: None

The radar

The San Juan radar (TJUA), 32 km from the middle of the area, began a volume at 16:18 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

What was reported inside it

Time	Report	Where	Remark
Oct 20, 11:35 AM CDT	FLASH FLOOD	5 Ese Guaynabo, PR	VIPER EMAIL FROM A 911 CALL AND EMERGENCY MANAGERS REPORTED OF A RESIDENCE BEING FLOODED IN SECTOR LOS CHOFERES/CAMINO LOS GONZALEZ IN SAN JUAN. FIREFIGHTERS AND RESCUE WERE ABLE TO EVACUATE AN AGING COUPLE.
Oct 20, 11:35 AM CDT	FLASH FLOOD	5 Ese Guaynabo, PR	VIPER EMAIL FROM A 911 CALL REPORTED OF A RESIDENCE BEING FLOODED IN SECTOR LOS CHOFERES/CAMINO LOS GONZALEZ IN SAN JUAN.
Oct 20, 11:38 AM CDT	FLASH FLOOD	San Juan, PR	TRIBUTARY OF QUEBRADA COLORADO OUT OF ITS BANKS IN SAN JUAN, ROAD 844 IMPASSABLE NEAR FARMACIA CARRAIZO.
Oct 20, 1:15 PM CDT	FLOOD	San Juan, PR	URBAN FLOODING WAS REPORTED BY EMERGENCY MANAGEMENT ACROSS URB, SAGRADO CORAZON, SAN JUAN.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The text

As transmitted.

087 
WGCA52 TJSJ 201619
FFWSJU
PRC061-127-201930-
/O.NEW.TJSJ.FF.W.0017.211020T1619Z-211020T1930Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service San Juan PR
1219 PM AST Wed Oct 20 2021

The National Weather Service in San Juan has issued a

* Flash Flood Warning for...
  Guaynabo in Puerto Rico...
  San Juan in Puerto Rico...

* Until 330 PM AST.

* At 1219 PM AST, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 1 and 2 inches of rain 
  have fallen. Additional rainfall amounts of 1 to 2 inches are 
  possible in the warned area. Flash flooding is ongoing or expected 
  to begin shortly.

  HAZARD...Flash flooding caused by thunderstorms.

  SOURCE...Radar and Emergency Managers.

  IMPACT...Flash flooding of small creeks and streams, urban
           areas, highways, streets and underpasses as well as
           other poor drainage and low-lying areas.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 1842 6608 1843 6606 1847 6613 1845 6604
      1843 6603 1840 6599 1838 6600 1837 6603
      1830 6605 1828 6614 1838 6614 1838 6612
      1842 6613 1844 6611 1843 6611 1844 6609
      1843 6608

FLASH FLOOD...RADAR INDICATED

$$

CAM

3 follow-up statements

738 
WGCA72 TJSJ 201655
FFSSJU

Flash Flood Statement
National Weather Service San Juan PR
1255 PM AST Wed Oct 20 2021

PRC061-127-201930-
/O.CON.TJSJ.FF.W.0017.000000T0000Z-211020T1930Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Guaynabo PR-San Juan PR-
1255 PM AST Wed Oct 20 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 330 PM AST THIS 
AFTERNOON FOR GUAYNABO AND SAN JUAN...

At 1255 PM AST, Doppler radar indicated another thunderstorm 
producing heavy rain across the warned area. Between 1 and 2 inches 
of rain have fallen. Additional rainfall amounts of 1 to 2 inches 
are possible in the warned area. Emergency Managers reported 
multiple flooded areas around Rio Piedra and Cupey. Flash flooding 
is ongoing or expected to begin shortly.

HAZARD...Flash flooding caused by thunderstorms.

SOURCE...Radar and Emergency Management.

IMPACT...Flash flooding of small creeks and streams, urban areas,
         highways, streets and underpasses as well as other poor
         drainage and low-lying areas.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 1842 6608 1843 6606 1847 6613 1845 6604
      1843 6603 1840 6599 1838 6600 1837 6603
      1830 6605 1828 6614 1838 6614 1838 6612
      1842 6613 1844 6611 1843 6611 1844 6609
      1843 6608

FLASH FLOOD...RADAR INDICATED

$$

CAM

747 
WGCA72 TJSJ 201821
FFSSJU

Flash Flood Statement
National Weather Service San Juan PR
221 PM AST Wed Oct 20 2021

PRC061-127-201930-
/O.CON.TJSJ.FF.W.0017.000000T0000Z-211020T1930Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Guaynabo PR-San Juan PR-
221 PM AST Wed Oct 20 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 330 PM AST THIS 
AFTERNOON FOR GUAYNABO AND SAN JUAN...

At 221 PM AST, Doppler radar indicated moderate to locally heavy 
rain across the warned area. Up to 4 inches of rain have fallen. 
Additional rainfall amounts up to 1 inch are possible across the 
warned area, aggravating any ongoing flooding. In fact, Emergency 
managers have reported a mudslide near Camino Los Tomales along road 
PR-844 in San Juan.

HAZARD...Flash flooding caused by thunderstorms.

SOURCE...Radar.

IMPACT...Flash flooding of small creeks and streams, urban areas,
         highways, streets and underpasses as well as other poor
         drainage and low-lying areas.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 1842 6608 1843 6606 1847 6613 1845 6604
      1843 6603 1840 6599 1838 6600 1837 6603
      1830 6605 1828 6614 1838 6614 1838 6612
      1842 6613 1844 6611 1843 6611 1844 6609
      1843 6608

FLASH FLOOD...RADAR INDICATED

$$

ICP

478 
WGCA72 TJSJ 201921
FFSSJU

Flash Flood Statement
National Weather Service San Juan PR
321 PM AST Wed Oct 20 2021

PRC061-127-201931-
/O.CAN.TJSJ.FF.W.0017.000000T0000Z-211020T1930Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Guaynabo PR-San Juan PR-
321 PM AST Wed Oct 20 2021

...FLASH FLOOD WARNING FOR SAN JUAN HAS BEEN REPLACED WITH A FLOOD 
ADVISORY...

LAT...LON 1845 6604 1843 6603 1840 6599 1839 6600
      1838 6600 1838 6603 1837 6603 1830 6605
      1830 6608 1833 6609 1834 6610 1838 6609
      1839 6611 1840 6611 1841 6609 1844 6611
      1844 6609 1842 6608 1843 6606 1847 6613

$$

ICP

The office that day

Everything else NWS JSJ issued on the same UTC day.

Issued	Product	Office	Lasted
Oct 20, 10:57 AM CDT	Areal Flood Advisory	JSJ	2 hr
Oct 20, 11:13 AM CDT	Special Weather Statement	JSJ	47 min
Oct 20, 12:21 PM CDT	Special Weather Statement	JSJ	54 min
Oct 20, 12:41 PM CDT	Areal Flood Advisory	JSJ	3 hr
Oct 20, 1:00 PM CDT	Areal Flood Advisory	JSJ	3 hr
Oct 20, 1:10 PM CDT	Areal Flood Advisory	JSJ	3 hr
Oct 20, 1:35 PM CDT	Areal Flood Advisory	JSJ	3 hr
Oct 20, 2:21 PM CDT	Areal Flood Advisory	JSJ	2 hr
Oct 20, 2:44 PM CDT	Areal Flood Advisory	JSJ	2 hr
Oct 20, 3:03 PM CDT	Flash Flood Warning	JSJ	46 min

Nearby

Flash Flood Warnings in Puerto Rico, 2021 Every flash flood warning in 2021

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; radar from the NEXRAD Level II archive.