Alert archive / Puerto Rico / Flash Flood Warnings in 2004

Flash Flood Warning 70, NWS JSJ

October 31, 2004

NWS JSJ issued this flash flood warning at Oct 31, 2004, 12:19 PM CST. It was in force for 19 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, 12:19 PM CST (18:19 UTC)
Expired
Nov 1, 2004, 7:15 AM CST
In force
19 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 311822
FFWSJU
PRC021-033-061-105-127-135-137-312115-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SAN JUAN PR
219 PM AST SUN OCT 31 2004

THE NATIONAL WEATHER SERVICE IN SAN JUAN HAS ISSUED A

* A FLASH FLOOD WARNING FOR THE FOLLOWING MUNICIPALITIES
  IN PUERTO RICO
     NARANJITO
     SAN JUAN
     TOA ALTA
     BAYAMON
     GUAYNABO
     CATANO
     TOA BAJA

* UNTIL 515 PM AST

* AT 217 PM AST NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED 
VERY HEAVY RAIN OVER THE SAN JUAN METRO AREA. RADAR ESTIMATED OVER 2 
INCHES OF RAINFALL ACCUMULATION WITH ADDITIONAL SHOWERS OCCURRING.

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

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF SMALL
CREEKS AND STREAMS...HIGHWAYS AND UNDERPASSES. ADDITIONALLY...ROADS
AND LAND ALONG THE BANKS OF CREEKS...STREAMS AND OTHER LOW LYING
AREAS ARE SUBJECT TO FLOODING. THE HEAVY RAIN COULD ALSO CAUSE
MUDSLIDES IN AREAS OF STEEP TERRAIN.

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 1845 6605 1834 6605 1831 6608 1830 6614
      1830 6632 1845 6622

$$

ELM
1 follow-up statement
000 
WGCA72 TJSJ 312116
FFSSJU
PRC021-033-061-105-127-135-137-312200-

URGENT - IMMEDIATE BROADCAST REQUESTED
FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SAN JUAN PR
515 PM AST SUN OCT 31 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
     NARANJITO
     SAN JUAN
     TOA ALTA
     BAYAMON
     GUAYNABO
     CATANO
     TOA BAJA

AT 510 PM AST WEATHER SERVICE DOPPLER RADAR INDICATED THAT THE HEAVY 
RAINS WHICH AFFECTED THESE AREAS EARLIER HAVE DECREASED. 

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

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.

$$

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, 3:00 AM CST, 9 hours 19 minutes earlier.

Area forecast discussion, Oct 31, 3:00 AM CST, 9 hours 19 minutes before
PUERTO RICO AND U.S. VIRGIN ISLANDS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
500 AM AST SUN OCT 31 2004

.DISCUSSION...
CONSIDERABLE AMOUNTS OF LOW LEVEL MOISTURE CONTINUES TO MOVE ACROSS
THE REGION DURING THE OVERNIGHT AND EARLY MORNING HOURS. THIS IS
ASSOCIATED WITH THE REMNANTS OF A LOW LEVEL TROUGH WHICH HAD SHIFTED
BACK TO THE WEST ACROSS THE REGION...AFTER LINGERING ACROSS THE
EASTERN CARIBBEAN FOR THE PAST FEW DAYS. DEEP MID TO UPPER LEVEL
TROUGH REMAINS JUST NORTH OF THE LOCAL REGION WITH A JET SEGMENT
MOVING ACROSS THE LOCAL AREA AT BASE OF TROUGH IN WESTERLY FLOW.
THIS WILL CONTINUE TO PROVIDE UPPER LEVEL SUPPORT FOR LOW LEVEL
CONVECTION OVER THE LOCAL REGION TODAY THROUGH MONDAY. LATEST MODEL
GUIDANCE CONTINUES TO SUGGEST THAT UPPER TROUGH WILL REESTABLISH
ITSELF OVER THE REGION AS A SHORT WAVE TROUGH AND ASSOCIATED
VORTICITY CENTER SINKS FURTHER SOUTH ACROSS THE LOCAL REGION TODAY
THROUGH MONDAY.

SURFACE HIGH PRESSURE ACROSS THE WEST ATLANTIC WILL CONTINUE BUILD
AND SINK SOUTH ACROSS THE LOCAL REGION DURING THE NEXT FEW DAYS...
THEREBY TIGHTENING THE LOW LEVEL PRESSURE GRADIENT. THIS WILL
PROVIDE A MODERATE EASTERLY WIND FLOW AND GOOD LOW LEVEL CONVERGENCE
ZONE OVER THE LOCAL AREA FOR THE NEXT FEW DAYS. A TROPICAL WAVE WITH
AN ASSOCIATED WEAK LOW PRESSURE CENTER NEAR 18 NORTH 60 WEST THIS
MORNING WILL CONTINUE TO MOVE SLOWLY WESTWARD AND ENTER THE LOCAL
REGION TODAY THROUGH MONDAY. THE INTERACTION OF THESE FEATURES AND
LOCAL EFFECTS WILL MAINTAIN FAIR AMOUNTS OF LOW LEVEL MOISTURE AND
UNSETTLED WEATHER CONDITIONS ACROSS THE REGION THROUGH THE EARLY
PORTIONS OF THE WEEK.

&&

.MARINE...
THE TIGHTENING OF THE PRESSURE GRADIENT AIDED BY A TROPICAL WAVE
APPROACHING THE EASTERN CARIBBEAN WILL ENHANCE THE LOCAL TRADE WIND
FLOW ACROSS THE REGIONAL WATERS. THE INTERACTION OF UPPER TROUGH AND
A MID LEVEL VORTICITY CENTER COMBINED WITH INCREASING LOW LEVEL
WINDS AND MOISTURE WILL CONTINUE TO PRODUCE AREAS OF DEEP CONVECTION
ACROSS THE REGIONAL WATERS THROUGH MONDAY. MARINERS SHOULD THEREFORE
REMAIN ALERT FOR ASSOCIATED HAZARDOUS WEATHER CONDITIONS. NORTHERLY
SWELLS WILL PERSIST AT LEAST THROUGH THROUGH TUESDAY WITH SEAS OF 5
TO 7 FEET IN THE ATLANTIC WATERS. A SMALL CRAFT ADVISORY IS IN
EFFECT FOR THE OFFSHORE ATLANTIC WATERS. MARINERS SHOULD EXERCISE
CAUTION IN NEAR SHORE ATLANTIC WATERS.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU  87  75  86  75 /  40  40  40  60
STT  87  76  86  76 /  40  40  40  60

&&

.SJU WATCHES/WARNINGS/ADVISORIES...
PR...SCA AMZ710.
VI...NONE.

&&

MITCHELL
Hazardous weather outlook, Oct 31, 4:30 AM CST, 7 hours 49 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

Nearby

Flash Flood Warnings in Puerto Rico, 2004Every 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.