Alert archive / Puerto Rico / Flash Flood Warnings in 2010

Flash Flood Warning 13, NWS JSJ

April 23, 2010

NWS JSJ issued this flash flood warning at Apr 23, 2010, 5:39 PM CDT. It was in force for 5 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: Apr 23, 2010, 5:39 PM CDT (22:39 UTC)
Expired: Apr 23, 2010, 11:02 PM CDT
In force: 5 hr
Issued by: NWS JSJ
Area: Storm-based polygon
Flood severity: None

The radar

The San Juan radar (TJUA), 98 km from the middle of the area, began a volume at 22:40 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, in the capitals the NWS used until 2016.

516 
WGCA52 TJSJ 232239
FFWSJU
PRC121-125-240430-
/O.NEW.TJSJ.FF.W.0013.100423T2239Z-100424T0430Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SAN JUAN PR
639 PM AST FRI APR 23 2010

THE NATIONAL WEATHER SERVICE IN SAN JUAN HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  THE FOLLOWING MUNICIPALITIES

  IN PUERTO RICO
     SABANA GRANDE
     SAN GERMAN

* UNTIL 1230 AM AST

* AT 6:30 PM AST...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED 
VERY HEAVY RAIN IN THE UPPER REACHES OF THE RIO GUANAJIBO AND ITS 
TRIBUTARIES. NWS DOPPLER WEATHER RADAR INDICATED AT LEAST 4 TO 6 
INCHES HAVE FALLEN IN THE NORTHERN PORTION OF SABANA GRANDE AND THIS 
WATER WILL WORK ITS WAY DOWN THROUGH THE RIVER DURING THE NEXT 
SEVERAL HOURS.

THE RIVER GAGE ON THE RIO GUANAJIBO HAS NOT YET BEGUN RISING...BUT 
IS EXPECTED TO CREST OVER FLOOD STAGE OF 13 FEET DURING THE NEXT 
SEVERAL HOURS. THIS WATER WILL EVENTUALLY REACH HORMIGUEROS.

TO REPORT FLOODING...HAVE THE NEAREST LAW ENFORCEMENT AGENCY RELAY
YOUR REPORT TO THE NATIONAL WEATHER SERVICE FORECAST OFFICE IN SAN
JUAN.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A FLASH FLOOD WARNING MEANS THAT FLOODING IS IMMINENT OR OCCURRING.
IF YOU ARE IN THE WARNING AREA MOVE TO HIGHER GROUND IMMEDIATELY.
RESIDENTS LIVING ALONG STREAMS AND CREEKS SHOULD TAKE IMMEDIATE
PRECAUTIONS TO PROTECT LIFE AND PROPERTY. DO NOT ATTEMPT TO CROSS
SWIFTLY FLOWING WATERS OR WATERS OF UNKNOWN DEPTH BY FOOT OR BY
AUTOMOBILE.

&&

LAT...LON 1809 6701 1815 6697 1815 6694 1804 6693
      1806 6699 1810 6709 1814 6707

$$

SNELL

ADDITIONAL INFORMATION CAN BE FOUND AT /USE LOWER CASE LETTERS/:
     HTTP://WWW.WEATHER.GOV/SANJUAN

2 follow-up statements

559 
WGCA72 TJSJ 240049
FFSSJU

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SAN JUAN PR
849 PM AST FRI APR 23 2010

PRC121-125-240430-
/O.CON.TJSJ.FF.W.0013.000000T0000Z-100424T0430Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
SABANA GRANDE PR-SAN GERMAN PR-
849 PM AST FRI APR 23 2010

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1230 AM AST FOR SAN
GERMAN AND SABANA GRANDE MUNICIPALITIES...

AT 826 PM AST...THE RIO GUANAJIBO ENTERED FLOOD STAGE IN SAN GERMAN 
AND IS EXPECTED TO CONTINUE RISING. ONLY VERY LIGHT SHOWERS ARE 
FALLING IN THE RIO GUANAJIBO BASIN...BUT OVER FIVE AND ONE HALF 
INCHES FELL IN THE BASIN UPSTREAM BEFORE 6 PM AND IT WILL BE SWOLLEN 
FOR QUITE SOME TIME WITH THESE WATERS. THEREFORE THE FLASH FLOOD 
WARNING FOR THE RIO GUANAJIBO ABOVE HORMIGUEROS WILL CONTINUE AND A 
FLOOD WARNING FOR THE RIO GUANAJIBO AT HORMIGUEROS WILL BE ISSUED 
BEFORE 9 PM AST.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE
DANGERS OF FLOODING. IF FLASH FLOODING IS OBSERVED ACT QUICKLY. MOVE
UP TO HIGHER GROUND TO ESCAPE FLOOD WATERS. DO NOT STAY IN AREAS
SUBJECT TO FLOODING WHEN WATER BEGINS RISING.

&&

LAT...LON 1809 6701 1815 6697 1815 6694 1804 6693
      1806 6699 1810 6709 1814 6707

$$

SNELL

ADDITIONAL INFORMATION CAN BE FOUND AT /USE LOWER CASE LETTERS/:
     HTTP://WWW.WEATHER.GOV/SANJUAN

513 
WGCA72 TJSJ 240402
FFSSJU

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SAN JUAN PR
1202 AM AST SAT APR 24 2010

PRC121-125-240408-
/O.CAN.TJSJ.FF.W.0013.000000T0000Z-100424T0430Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
SABANA GRANDE PR-SAN GERMAN PR-
1202 AM AST SAT APR 24 2010

...THE FLASH FLOOD WARNING HAS BEEN CANCELLED FOR SAN GERMAN AND
SABANA GRANDE MUNICIPALITIES...

AT 1155 PM AST...THE HEAVY RAINFALL ACROSS PORTIONS OF SABANA GRANDE 
AND SAN GERMAN HAD MOSTLY DISSIPATED AND THE RIVERS ACROSS THAT AREA 
HAS BEEN SLOWLY RECEDING FOR THE PAST FEW HOURS. FOR THIS 
REASON...THE FLASH FLOOD WARNING HAS BEEN CANCELED.  

WHILE THE FLASH FLOOD WARNING IS BEING ALLOWED TO EXPIRE...LOCAL 
RESIDENTS AND MOTORISTS SHOULD EXERCISE EXTREME CAUTION WHEN 
TRAVELING THROUGH THIS AREA DURING THE REMAINDER OF OVERNIGHT HOURS 
AS IT TAKES ONLY A FEW INCHES OF RAPIDLY FLOWING WATER TO CARRY AWAY 
A VEHICLE.

LAT...LON 1809 6701 1815 6697 1815 6694 1804 6693
      1806 6699 1810 6709 1814 6707

$$

FIGUEROA

ADDITIONAL INFORMATION CAN BE FOUND AT /USE LOWER CASE LETTERS/:
     HTTP://WWW.WEATHER.GOV/SANJUAN

The office that day

Everything else NWS JSJ issued on the same UTC day.

Issued	Product	Office	Lasted
Apr 23, 11:56 AM CDT	Areal Flood Advisory	JSJ	2 hr
Apr 23, 12:57 PM CDT	Areal Flood Advisory	JSJ	3 hr
Apr 23, 3:03 PM CDT	Areal Flood Advisory	JSJ	117 min
Apr 23, 3:46 PM CDT	Areal Flood Advisory	JSJ	104 min
Apr 23, 4:08 PM CDT	Areal Flood Advisory	JSJ	112 min
Apr 23, 4:46 PM CDT	Flash Flood Warning	JSJ	2 hr
Apr 23, 4:58 PM CDT	Flash Flood Warning	JSJ	3 hr
Apr 23, 5:47 PM CDT	Areal Flood Advisory	JSJ	3 hr
Apr 23, 5:54 PM CDT	Flash Flood Warning	JSJ	111 min
Apr 23, 6:00 PM CDT	Areal Flood Advisory	JSJ	60 min

Nearby

Flash Flood Warnings in Puerto Rico, 2010 Every flash flood warning in 2010

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.