Alert archive / Puerto Rico / Flash Flood Warnings in 2021

Flash Flood Warning 1, NWS JSJ

March 24, 2021

NWS JSJ issued this flash flood warning at Mar 24, 2021, 2:12 PM CDT. It was in force for 2 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: Mar 24, 2021, 2:12 PM CDT (19:12 UTC)
Expired: Mar 24, 2021, 4:15 PM CDT
In force: 2 hr
Issued by: NWS JSJ
Area: Storm-based polygon
Flood severity: None

The radar

The San Juan radar (TJUA), 28 km from the middle of the area, began a volume at 19:15 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.

The text

As transmitted.

660 
WGCA52 TJSJ 241912
FFWSJU
PRC021-061-242115-
/O.NEW.TJSJ.FF.W.0001.210324T1912Z-210324T2115Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service San Juan PR
312 PM AST Wed Mar 24 2021

The National Weather Service in San Juan has issued a

* Flash Flood Warning for...
  Bayamon County in Puerto Rico...
  Guaynabo County in Puerto Rico...

* Until 515 PM AST.

* At 312 PM AST, Emergency management reported heavy rain across the 
  warned area in and around Quebrada Margarita and road#19, and 
  Expresso Martinez Nadal as well roads in Guaynabo. Between 1 and 2 
  inches of rain have fallen. Urban  flooding is ongoing or expected 
  to begin shortly.

  HAZARD...Flash flooding caused by heavy rain.

  SOURCE...Emergency management.

  IMPACT...Flooding of small creeks and streams, urban areas,
           highways, streets and underpasses as well as other
           drainage and low lying areas.

* Some locations that will experience flash flooding include...
  San Juan, Bayamon, Guaynabo, Sabana Seca and Candelaria.

Additional rainfall amounts of 1 to 2 inches are possible in the 
warned area.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Excessive runoff from heavy rainfall will cause flooding of small 
creeks and streams, urban areas, highways, streets and underpasses 
as well as other drainage areas and low lying spots.

Excessive runoff from heavy rainfall will cause flooding of small 
creeks and streams, country roads, farmland, and other low lying 
spots.

&&

LAT...LON 1842 6616 1842 6614 1844 6611 1841 6609
      1839 6611 1838 6611 1838 6609 1836 6609
      1834 6609 1832 6609 1830 6608 1828 6611
      1828 6616 1826 6619 1828 6620 1830 6620
      1834 6620 1841 6620 1842 6617 1843 6617

FLASH FLOOD...OBSERVED

$$

RAM/LIS

2 follow-up statements

380 
WGCA72 TJSJ 242050
FFSSJU

Flash Flood Statement
National Weather Service San Juan PR
450 PM AST Wed Mar 24 2021

PRC021-061-242115-
/O.CON.TJSJ.FF.W.0001.000000T0000Z-210324T2115Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Bayamon PR-Guaynabo PR-
450 PM AST Wed Mar 24 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 515 PM AST THIS 
AFTERNOON FOR BAYAMON AND GUAYNABO COUNTIES...

At 450 PM AST, Emergency management flood waters from recent heavy 
rains across the warned area continue across roadways causing road 
closures. Estimated amounts between 1 and 3 inches of rain had 
fallen. Urban flooding is ongoing and expected to continue at least 
until another 30 mins or so.

HAZARD...Flash flooding caused by heavy rain.

SOURCE...Emergency management.

IMPACT...Flooding of small creeks and streams, urban areas,
         highways, streets and underpasses as well as other
         drainage and low lying areas.

Some locations that will experience flash flooding include...
  San Juan, Bayamon, Guaynabo, Sabana Seca and Candelaria.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Excessive runoff from heavy rainfall will cause flooding of small 
creeks and streams, urban areas, highways, streets and underpasses 
as well as other drainage areas and low lying spots.



&&

LAT...LON 1842 6616 1842 6614 1844 6611 1841 6609
      1839 6611 1838 6611 1838 6609 1836 6609
      1834 6609 1832 6609 1830 6608 1828 6611
      1828 6616 1826 6619 1828 6620 1830 6620
      1834 6620 1841 6620 1842 6617 1843 6617

FLASH FLOOD...OBSERVED

$$

RAM

138 
WGCA72 TJSJ 242110
FFSSJU

Flash Flood Statement
National Weather Service San Juan PR
510 PM AST Wed Mar 24 2021

PRC021-061-242120-
/O.EXP.TJSJ.FF.W.0001.000000T0000Z-210324T2115Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Bayamon PR-Guaynabo PR-
510 PM AST Wed Mar 24 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 515 PM AST THIS AFTERNOON FOR 
BAYAMON AND GUAYNABO COUNTIES...

Flood waters continue to recede. The heavy rain has ended. Flooding 
is no longer expected to pose a threat. Please remain alert to 
ponded water on roadways and heed to road closures and allow time 
for flood waters to recede during the next hour or so.

LAT...LON 1842 6616 1842 6614 1844 6611 1841 6609
      1839 6611 1838 6611 1838 6609 1836 6609
      1834 6609 1832 6609 1830 6608 1828 6611
      1828 6616 1826 6619 1828 6620 1830 6620
      1834 6620 1841 6620 1842 6617 1843 6617

$$

RAM

The office that day

Everything else NWS JSJ issued on the same UTC day.

Issued	Product	Office	Lasted
Mar 24, 11:45 AM CDT	Areal Flood Advisory	JSJ	4 hr
Mar 24, 3:09 PM CDT	Areal Flood Advisory	JSJ	111 min
Mar 24, 4:28 PM CDT	Areal Flood Advisory	JSJ	62 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; radar from the NEXRAD Level II archive.