Alert archive / Puerto Rico / Flash Flood Warnings in 2004

Flash Flood Warning 73, NWS JSJ

October 31, 2004

NWS JSJ issued this flash flood warning at Oct 31, 2004, 11:23 PM CST. It was in force for 18 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: Oct 31, 2004, 11:23 PM CST (05:23 UTC)
Expired: Nov 1, 2004, 5:30 PM CST
In force: 18 hr
Issued by: NWS JSJ
Area: Counties, with a storm outline in the text

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, in the capitals the NWS used until 2016.

000 
WGCA52 TJSJ 010525
FFWSJU
PRC077-085-010730-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SAN JUAN PR
123 AM AST MON NOV 1 2004

THE NATIONAL WEATHER SERVICE IN SAN JUAN HAS ISSUED A

* A FLASH FLOOD WARNING FOR THE FOLLOWING MUNICIPALITIES
  IN PUERTO RICO
     JUNCOS
     LAS PIEDRAS

* UNTIL 330 AM AST

* AT 119 AM AST NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED   
FLASH FLOODING AND RIVER GAGES INDICATED THAT RIO VALENCIANO AND RIO 
HUMACAO WERE ABOVE FLOOD STAGE OR ABOUT TO FLOOD.

THIS WARNING INCLUDES ALL RIVERS AND STREAMS AND THEIR TRIBUTARIES IN
THE WARNED AREA

A FLASH FLOOD WARNING MEANS THAT FLASH FLOODING IS IMMINENT OR HAS
BEEN REPORTED. EVACUATE TO HIGHER GROUND AND TAKE THE NECESSARY
PRECAUTIONS SHOULD FLOOD WATERS AFFECT YOUR AREA. MOTORISTS AND
PEDESTRIANS SHOULD NOT ATTEMPT TO CROSS FLOODED ROADS AND AREAS...AS
YOU AND YOUR VEHICLE MIGHT BE SWEPT AWAY BY FLOOD WATERS. PERSONS IN
LOW LYING AREAS SHOULD SEEK HIGHER GROUND. FOLLOW INSTRUCTIONS FROM
LOCAL CIVIL DEFENSE OR LAW OFFICIALS.

LAT...LON 1820 6591 1825 6591 1822 6588 1822 6582
      1817 6588

$$

SNELL

1 follow-up statement

000 
WGCA72 TJSJ 010752
FFSSJU
PRC077-085-010845-

URGENT - IMMEDIATE BROADCAST REQUESTED
FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SAN JUAN PR
330 AM AST MON NOV 1 2004

THE FLASH FLOOD WARNING ISSUED EARLIER BY THE NATIONAL WEATHER
SERVICE IN SAN JUAN HAS BEEN DISCONTINUED FOR THE FOLLOWING
MUNICIPALITIES

IN PUERTO RICO

    JUNCOS
    LAS PIEDRAS
     

AT 3:25 AM AST...THE WEATHER SERVICE DOPPLER RADAR INDICATED THAT 
THE HEAVY RAIN WHICH AFFECTED THESE AREAS EARLIER HAS EITHER 
DIMINISHED...DISSIPATED OR MOVED AWAY. NO ADDITIONAL HEAVY RAINFALL 
IS EXPECTED ACROSS THESE AREAS AT THIS TIME.

THEREFORE FLASH FLOODING NO LONGER EXISTS AND THE FLASH FLOOD WARNING
HAS BEEN DISCONTINUED. HOWEVER...THERE WILL BE SOME ADDITIONAL 
LIGHT TO MODERATE SHOWERS FROM TIME TO TIME ACROSS THESE 
MUNICIPALITIES. ANY ADDITIONAL RAINFALL WILL QUICKLY RUNOFF. 
THEREFORE...RESIDENTS AND MOTORISTS ACROSS THESE AREAS SHOULD 
CONTINUE TO USE CAUTION DURING EARLY MORNING HOURS.

ALTHOUGH FLASH FLOODING NO LONGER EXISTS YOU SHOULD CONTINUE TO
REMAIN ALERT FOR ANY LINGERING WATER ON THE ROADWAYS AND HIGH STREAM 
OR RIVER LEVELS. RESIDENTS SHOULD STILL STAY AWAY FROM RIVERS AND 
STREAMS ACROSS THESE AREAS UNTIL THEY HAVE RETURNED TO NORMAL 
LEVELS. 

$$

MITCHELL

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 Oct 31, 2:15 PM CST, 9 hours 8 minutes earlier.

Area forecast discussion, Oct 31, 2:15 PM CST, 9 hours 8 minutes before

PUERTO RICO AND U.S. VIRGIN ISLANDS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
415 PM AST SUN OCT 31 2004

.DISCUSSION...
MID TO UPPER VORT HAS SUNKEN INTO HISPANIOLA TODAY WITH RIDGING
OCCURRING ALONG ABOUT 60 WEST...WITH BACKING FLOW ALOFT ACROSS THE
LOCAL AREA PRODUCING GOOD DIVERGENCE LOCALLY FOR ACTIVE WEATHER
TODAY. GFS FORECASTING VERY FAVORABLE AND SIMILAR DYNAMICS ACROSS
THE LOCAL AREA THROUGH MONDAY NIGHT...WITH TROUGH AXIS THEN SHIFTING
JUST SOUTH OF THE LOCAL AREA FOR SOME STABILIZATION ALOFT. AMPLE
LLVL MOISTURE WILL PERSIST ACROSS THE AREA IN INCREASING ENE FLOW
TONIGHT AND MONDAY FOR SCATTERED TO NUMEROUS SHOWERS AND ISOLATED TO
WIDELY SCATTERED TSTORMS. TROPICAL WAVE ALONG 63 WEST THIS AFTERNOON
IS NOT FORECAST TO PROVIDE SIGNIFICANT MOISTURE OR LLVL INSTABILITY
BEYOND WHAT WE HAVE SEEN PAST 24 HOURS. HOWEVER...GFS HAS CONTINUED
TO FORECAST SIGNIFICANT LLVL MOISTURE ON TUESDAY...AND WE HAVE
ASSUMED THAT THIS WAS TROPICAL WAVE RELATED. HOWEVER...INSPECTION OF
LONG TERM STLT IMAGERY SUGGESTS THAT A ITCZ PERTURBATION HAS MOVED
QUICKLY ACROSS THE ATLC AND HAS CAUGHT UP TO THE TROPICAL
WAVE...WHICH HAS ACCELERATED A BIT TODAY. THE ASSOCIATED CONVERGENCE
BETWEEN THE ITCZ PERTURBATION ADVECTING NW AND MOISTURE ON THE BACK
SIDE OF THE WAVE WILL BRING ABUNDANT MOISTURE TO THE AREA ON TUESDAY
FOR A VERY WET AND SHOWERY DAY. RAIN TODAY AND MONDAY WILL SET THE
STAGE ON TUESDAY FOR WIDESPREAD FLOOD POTENTIAL. CURRENT RAIN
CHANCES ARE ONLY IN THE 50-70% RANGE...AND STILL MAY BE A BIT LOW
FOR ISOLATED AREAS...AND LOW AREA WIDE ON TUESDAY.

SCA CONTINUES IN EFFECT FOR OFF SHORE ATLC WATERS DUE TO MODERATE
NNE SWELLS AND BUILDING WIND WAVES IN INCREASING ENE FLOW. SEAS ARE
FORECAST TO MAXIMIZE ON MONDAY.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU  75  86  75  84 /  50  50  60  50
STT  76  86  76  84 /  50  50  60  50

&&

.SJU WATCHES/ADVISORIES...
PR...SCA AMZ710.
VI...SCA AMZ710.

&&

06

Hazardous weather outlook, Oct 31, 4:30 AM CST, 18 hours 53 minutes before

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE SAN JUAN PR
630 AM AST SUN OCT 31 2004

PRZ001>013-AMZ710>750-011100-
630 AM AST SUN OCT 31 2004

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PUERTO RICO.

.TODAY AND TONIGHT...

AN UPPER LEVEL TROUGH TO OUR WEST AND GOOD LOW LEVEL MOISTURE IS
MAKING CONDITIONS FAVORABLE TO HEAVY RAIN AND THUNDERSTORMS OVER
PUERTO RICO. AREAS OF URBAN AND SMALL STREAM FLOODING ARE EXPECTED
AND AN ISOLATED LOCAL RISE IN  AREA RIVERS APPROACHING OR EXCEEDING
FLOOD STAGE IS POSSIBLE.

.SPOTTER CALL TO ACTION STATEMENT...

SPOTTER ACTIVATION MAY BE NECESSARY.

.DAYS TWO THROUGH SEVEN...

AN UPPER LEVEL TROUGH PASSAGE ON MONDAY AND AN APPROACHING TROPICAL
WAVES WILL BRING HEAVIER THAN USUAL AMOUNTS OF RAINFALL TO THE AREA
MONDAY AND TUESDAY. HEAVIER RAINFALL IS ALSO INDICATED FOR FRIDAY
AND SATURDAY THAT MAY RESULT IN LOCAL URBAN AND SMALL STREAM
FLOODING.

VIZ001-002-AMZ710>730-011100-
630 AM AST SUN OCT 31 2004

THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE U.S. VIRGIN ISLANDS.

.TODAY AND TONIGHT...

SCATTERED SHOWERS AND THUNDERSTORMS WILL RESULT IN LOCALLY HEAVY
RAIN THAT MAY CAUSE GUTS TO RUN FULL AND PONDING IN LOW LYING AREAS.
OTHERWISE NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER CALL TO ACTION STATEMENT...

SPOTTER ACTIVATION IS NOT ANTICIPATED TODAY.

.DAYS TWO THROUGH SEVEN...

LOCALLY HEAVY RAIN MAY CAUSE GUTS TO RUN FULL MONDAY AND TUESDAY.
HEAVY RAINFALL FROM SHOWERS AND THUNDERSTORMS IS ALSO INDICATED ON
FRIDAY AND SATURDAY...THAT MAY CAUSE GUTS TO RUN FULL.

SNELL

The office that day

Everything else NWS JSJ issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Oct 31, 8:59 PM CST	Flash Flood Warning	JSJ		18 hr
Oct 31, 10:17 PM CST	Flash Flood Warning	JSJ		19 hr

Nearby

Flash Flood Warnings in Puerto Rico, 2004 Every flash flood warning in 2004

Sources

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