1 flash flood, as filed by the National Weather Service.
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS San Juan, PR wrote its last area forecast discussion before the first event at May 20, 5:05 PM AST, 15 minutes earlier.
PUERTO RICO AND U.S. VIRGIN ISLANDS FORECAST DISCUSSION NATIONAL WEATHER SERVICE SAN JUAN PR 505 PM AST THU MAY 20 2004 .SYNOPSIS... MID TO UPPER LEVEL TROUGH REMAINS NORTH OF GREATER ANTILLES AND EAST TO WEST ALONG ABOUT 23-24 NORTH...WITH JET SEGMENT ON SOUTH SIDE PROVIDING DYNAMICS FOR THE LOCAL REGION AND MUCH OF THE EASTERN CARIBBEAN. S/W UPPER RIDGING BUILDING E ACROSS HISPANIOLA SHIFTING GOOD UPPER DIVERGENCE FROM JUST SOUTH OF P.R. TO THE NE CARIB AND LEEWARDS. ELONGATED LOW TO MID LEVEL TROUGHING EXTENDS FROM THE EPAC MONSOONAL TROUGH ENE ACROSS CENTRAL AMERICA AND INTO SW AND CENTRAL CARIB...AND THEN WEAKLY INTO LEEWARDS. SURFACE HIGH REMAINS ACROSS WESTERN ATLC AND RIDGE NOW EAST TO WEST MAINTAINING MODERATE EASTERLY TRADE WIND FLOW ACROSS THE LOCAL REGION. TROPICAL WAVE PASSED SOUTH OF P.R. YESTERDAY AND LOOKS TO HAVE CONTRIBUTED TO MID LEVEL CIRCULATION SEEN ON STLT IMAGERY OVER CARIB SOUTH OF HAITI...WITH NEXT UPSTREAM WAVE ALONG ABOUT 50/52W. CURRENT PATTERN ACROSS THE CARIB LOOKS MUCH MORE LIKE OCTOBER THAN MAY TO ME. && .DISCUSSION... VERY WET AND POTENTIALLY OMINOUS FORECAST ON TAP FOR THE LOCAL AREA NEXT FEW DAYS AS SW ATLC TROUGHING AND SHIFTING ANTICYCLONIC FLOW SPREADING ACROSS THE N AND NE CARIB TO PROVIDE VERY GOOD UPPER DIVERGENCE AND ACT TO VENT DEEP CONVECTION. GLOBAL MODELS REMAIN IN REASONABLE AGREEMENT IN TRYING TO DEVELOP SOME TYPE OF WEAK TO MODERATE LOW LEVEL LOW ACROSS THE CENTRAL CARIB SOUTH OF THE WINDWARD PASSAGE. SOME GOOD CYCLONIC TURNING CAN BE SEEN IN SATELLITE IMAGERY TODAY...BUT IS VERY ELONGATED FROM EPAC INTO CENTRAL CARIB...AND HOWEVER...THIS IS AT THE MIDDLE LEVELS AND NO EVIDENCE EXISTS OF A LLVL OR SURFACE LOW...EXCEPT IN THE EPAC...WHERE TPC IS RUNNING HURRICANE GUIDANCE. AT THIS TIME...NO DEVELOPMENT OF ANY TYPE OF EARLY SEASON TROPICAL SYSTEM IS ANTICIPATED ACROSS THE CARIB. THIS ELONGATED TROUGHING IS FORECAST TO LIFT NORTH AND NORTHWESTWARD OVER THE WEEKEND TO BRING ABUNDANT TROPICAL MOISTURE AND THE CHANCE FOR PERIODS OF COPIOUS RAINFALL AREA WIDE. FOR FRIDAY AND SATURDAY...LLVL MOISTURE IS FORECAST TO DECREASE FROM THAT OF TODAY...BUT WILL RETURN FROM THE SOUTHEAST SATURDAY AFTERNOON/EVENING THROUGH SUNDAY...AND THEN NEXT TROPICAL WAVE MOISTURE WILL BE DRAWN TO THE LOCAL AREA IN DEEP SE FLOW SUNDAY NIGHT THROUGH MONDAY OR TUESDAY. THERE WILL BE ALTERATIONS EACH DAY TO THIS EVOLVING WEATHER SCENARIO...AND LOCAL INTERESTS ARE URGED TO KEEP ABREAST OF THE LATEST INFORMATION AS IT BECOMES AVAILABLE. && .MARINE... WIND AND SEAS WILL LIKELY INCREASE FRIDAY NIGHT THROUGH SATURDAY NIGHT IN RESPONSE TO SOME TYPE OF LOW PRESSURE DEVELOPING ACROSS THE CARIBBEAN...INCREASING PRESSURE GRADIENT REGIONALLY. HOWEVER...HAVE DECIDED NOT TO GO WITH AGGRESSIVE FORECAST OF GFS AND KEPT WINDS TO 24 KNOTS OR LESS. AS TROUGH AND ANY SURFACE LOW OR LOWS LIFT NORTHWARD ACROSS HISPANIOLA SUNDAY-MONDAY...LLVL FLOW WILL VEER FROM ESE TO SE AND SEAS DROP QUICKLY MONDAY-TUESDAY. && .HYDROLOGY... A HYDROLOGICAL OUTLOOK WAS ISSUED TODAY...SJUESFSJU...TO ADDRESS RAIN AND FLOODING POTENTIAL NEXT SEVERAL DAYS. DAILY RAINFALL AMOUNTS OF 1 TO 3 INCHES ARE POSSIBLE FRIDAY AND SATURDAY IN THE HEAVIER CONVECTION...BUT COULD THEN INCREASE TO 3 TO 6 INCHES WITH LOCALLY MUCH HIGHER AMOUNTS LATE SATURDAY THROUGH MONDAY. NEEDLESS TO SAY...MAY RAINFALL ACROSS THE REGION HAS LEFT LOCAL SOILS WET AND NEAR SATURATED AND STREAMFLOW RESPONSE WILL BE QUICK AND ONLY GET WORSE EACH SUCCESSIVE DAY. ADDITIONAL STAFFING FOR ALL INVOLVED AGENCIES WILL LIKELY BE NEEDED SUNDAY AND MONDAY. && .PRELIMINARY POINT TEMPS/POPS... SJU 72 86 74 83 / 50 40 40 60 STT 71 85 73 82 / 50 40 40 40 && .SJU WATCHES/ADVISORIES... PR...NONE. VI...NONE. &&
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE SAN JUAN PR 600 AM AST THU MAY 20 2004 PRZ001>013-AMZ710>750-211000- 600 AM AST THU MAY 20 2004 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PUERTO RICO. .TODAY...A BROAD SURFACE TROUGH OF LOW PRESSURE FROM VENEZUELA NORTHEAST TO JUST SOUTH OF PUERTO RICO...COUPLED WITH FAVORABLE UPPER LEVEL WINDS...AND AMPLE AMOUNTS OF LOW TO MID LEVEL MOISTURE WILL SET THE STAGE FOR ANOTHER RAINY DAY ACROSS PUERTO RICO. WHILE THE HEAVIEST RAINS ARE EXPECTED TO REMAIN OVER THE OPEN WATERS OF THE EASTERN CARIBBEAN...CONDITIONS ARE SUCH THAT SCATTERED TO NUMEROUS SHOWERS WITH A FEW EMBEDDED THUNDERSTORMS WILL AFFECT MOST OF THE ISLAND...WITH THE HEAVIEST CONCENTRATION LIKELY DURING THE AFTERNOON AND EVENING HOURS. AS THIS MAY BE THE BEGINNING OF A PROLONGED PERIOD OF INTERMITTENT...HEAVY RAIN...THE RISK FOR FLASH FLOODING ISLAND WIDE AND POSSIBLE MUDSLIDES OVER MOUNTAIN TERRAIN REMAINS ELEVATED. A MODERATE TO OCCASIONALLY STRONG TRADE WIND FLOW OVER THE REGION WILL MAINTAIN ROUGH AND CHOPPY SEAS...WITH THE STRONGEST WINDS AND HIGHEST SEAS OVER THE ATLANTIC OFFSHORE WATERS. .SPOTTER CALL TO ACTION STATEMENT... SPOTTER ACTIVATION MAY BE REQUIRED. .DAYS TWO THROUGH SEVEN... THE BROAD LOW LEVEL TROUGH CURRENTLY OVER THE EASTERN CARIBBEAN WILL BE THE MAIN WEATHER MAKER THE NEXT FEW DAYS AS IT DRIFTS WESTWARD TO THE CENTRAL CARIBBEAN LATE THIS WEEKEND. THIS FEATURE IS THEN FORECAST TO MOVE NORTHWARD INTO THE SUBTROPICAL ATLANTIC BY MID WEEK NEXT WEEK. THE RESULT WILL BE A CONTINUATION OF THE PRESENT... UNSETTLED WEATHER PATTERN OVER PUERTO RICO AT LEAST THROUGH EARLY NEXT WEEK WITH SOME IMPROVEMENT EXPECTED FROM MID WEEK AND BEYOND. GIVEN THE PROTRACTED PERIOD OF WET WEATHER AHEAD...THERE WILL CONTINUE TO BE THE RISK OF DANGEROUS FLASH FLOODING AND MUDSLIDES...ESPECIALLY ON SUNDAY AND MONDAY. A MODERATE TO FRESH TRADE WIND FLOW AND CHOPPY SEAS WILL PREVAIL ACROSS THE LOCAL ISLANDS THROUGH AT LEAST EARLY NEXT WEEK BUT WINDS AND SEAS SHOULD BEGIN TO SUBSIDE MIDDLE AND LATE WEEK. VIZ001-002-AMZ710>730-211000- 600 AM AST THU MAY 20 2004 THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE U.S. VIRGIN ISLANDS. .TODAY...A BROAD SURFACE TROUGH OF LOW PRESSURE FROM VENEZUELA NORTHEAST TO JUST SOUTH PUERTO RICO...COUPLED WITH FAVORABLE UPPER LEVEL WINDS...AND AMPLE AMOUNTS OF LOW TO MID LEVEL MOISTURE WILL SET THE STAGE FOR ANOTHER RAINY DAY ACROSS THE U.S. VIRGIN ISLANDS. WHILE THE HEAVIEST RAINS ARE EXPECTED TO REMAIN OVER THE OPEN WATERS OF THE EASTERN CARIBBEAN...CONDITIONS ARE SUCH THAT SCATTERED TO NUMEROUS SHOWERS WITH A FEW ISOLATED THUNDERSTORMS MAY AFFECT THE U.S. VIRGIN ISLANDS...WITH THE HEAVIEST CONCENTRATION MOST LIKELY OVER ST. CROIX. SOME OF THESE STORMS MAY PRODUCE INTERMITTENT HEAVY RAINS THAT MAY CAUSE LOCALIZED FLOODING OF STREETS AND POOR DRAINAGE AREAS. A MODERATE TO OCCASIONALLY STRONG TRADE WIND FLOW OVER THE REGION WILL MAINTAIN ROUGH AND CHOPPY SEAS...WITH THE STRONGEST WINDS AND HIGHEST SEAS OVER THE ATLANTIC OFFSHORE WATERS. .SPOTTER CALL TO ACTION STATEMENT... SPOTTER ACTIVATION IS NOT ANTICIPATED. .DAYS TWO THROUGH SEVEN...THE BROAD LOW LEVEL TROUGH CURRENTLY OVER THE EASTERN CARIBBEAN WILL BE THE MAIN WEATHER MAKER ACROSS THE REGION THE NEXT FEW DAYS AS IT DRIFTS WESTWARD TO THE CENTRAL CARIBBEAN LATE THIS WEEKEND. THIS FEATURE IS THEN FORECAST TO MOVE NORTHWARD INTO THE SUBTROPICAL ATLANTIC BY MID WEEK NEXT WEEK. THE RESULT WILL BE A CONTINUATION OF THE PRESENT...UNSETTLED WEATHER PATTERN OVER PORTIONS OF THE U.S. VIRGIN ISLANDS AT LEAST THROUGH EARLY NEXT WEEK WITH SOME IMPROVEMENT EXPECTED FROM MID WEEK AND BEYOND. SIMILAR TO TODAYS FORECAST...OCCASIONAL HEAVY RAINS THROUGH MONDAY NEXT WEEK WILL CAUSE LOCAL FLOODING OF STREETS AND POOR DRAINAGE AREAS. A MODERATE TO FRESH TRADE WIND FLOW AND CHOPPY SEAS WILL PREVAIL ACROSS THE LOCAL ISLANDS THROUGH AT LEAST EARLY NEXT WEEK BUT WINDS AND SEAS SHOULD BEGIN TO SUBSIDE MIDDLE AND LATE WEEK. STAY TUNED TO NOAA WEATHER RADIO AND OTHER LOCAL MEDIA FOR FURTHER DETAILS OR UPDATES. FOR ADDITIONAL INFORMATION...VISIT THE NATIONAL WEATHER SERVICE WEB SITE FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS AT (ALL LOWERCASE LETTERS): HTTP://WWW.SRH.NOAA.GOV/SJU.
1 flash flood. Local standard time, as filed.
River Rio Guanajibo in San German flooded road 114 and for people were rescued from a vehicle trapped in the flooding. The river Guanajibo also flooded road 340.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Puerto Rico in 2004Every state in 2004This day in weather historyWarnings in Puerto Rico, May 2004
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 5398802.