1 thunderstorm wind, 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 Jul 21, 5:00 AM AST, 10 hours 20 minutes earlier.
PUERTO RICO AND U.S. VIRGIN ISLANDS FORECAST DISCUSSION NATIONAL WEATHER SERVICE SAN JUAN PR 500 AM AST WED JUL 21 2004 .SYNOPSIS... VIGOROUS TROPICAL WAVE WITH LOW LEVEL CYCLONIC CIRCULATION ALONG 70 WEST AT 08Z THIS MORNING AND CONTINUING TO MOVE WNW JUST OVER 20 KNOTS LEAVING A DEEP LAYERED SE FLOW SURFACE THROUGH 25K FEET ACROSS THE NE CARIB AND LOCAL AREA. UPPER LOW NEAR 27N 65 WEST NEARLY STATIONARY PAST 12-18 HOURS WITH TROUGHING EXTENDING SOUTHWEST ACROSS HISPANIOLA AND THEN EAST TO WEST ACROSS WEST CENTRAL CARIB ALONG 15.5N. SOUTHWESTERLY FLOW ALOFT FROM WAVE AXIS NE ACROSS LOCAL AREA CONTINUES TO PROVIDE GOOD VENTILATION AND DIVERGENCE FOR DEEP CONVECTION. && .DISCUSSION... COMBO OF UPPER HIGH TO THE EAST OF LEEWARDS AND UPPER LOW TO OUR NORTH WILL MAINTAIN UNSTABLE CONDITIONS ALOFT ACROSS THE AREA THROUGH THURSDAY...WITH GFS STILL FORECASTING LOW TO DRIFT SSW TODAY THEN SOUTH THURSDAY. DEEP LAYERED MOISTURE IN SE FLOW WILL PREVAIL ACROSS THE LOCAL AREA TODAY FOR NUMEROUS SHOWERS AND ISOLATED TO SCATTERED TSTORMS. WITH BROKEN LAYERED CLOUDINESS ACROSS THE AREA TODAY...SUNSHINE WILL BE INTERMITTENT AND THIS MAY NOT ALLOW FOR DIURNAL EFFECTS TO MAXIMIZE TODAY. THE FOCUS OF RAIN ACROSS P.R. MAY THUS OCCUR ACROSS THE SOUTHERN SLOPES AND CENTRAL AND SOUTHEAST INTERIOR WHERE 4 TO 5 INCH PRECIP TOTALS ARE POSSIBLE. HIGH PRESSURE WILL BEGIN TO NUDGE INTO THE LOCAL AREA AT LOW LEVELS TONIGHT BEHIND ITCZ CONNECTION TRAILING TROPICAL WAVE...WITH DECREASING MOISTURE NEXT FEW DAYS...ALLOWING DIURNAL/NOCTURNAL PROCESSES TO DOMINATE LOCAL WEATHER. && .TROPICAL WAVE ... A LOW LEVEL VORTEX (PROBABLY 3-5K FT) EMERGED FROM HIGH CLOUDS AND CONVECTIVE DEBRIS SOUTH OF PUERTO RICO LAST NIGHT...AND WAS MOVING OFF TO THE WEST NORTHWEST NEAR 22 KNOTS. HOWEVER...THE VORTEX BEGAN TO ENTER A REGION OF WEAK SHEAR SOUTH OF THE MONA PASSAGE AND HISPANIOLA...AND DEEP CONVECTION HAS AGAIN FLARED JUST TO THE EAST AND NORTH OF THE CENTER...WITH STLT IMAGERY THIS MORNING INDICATING CONVECTION TRYING TO DEVELOP AT OR NEAR THIS LOW LEVEL CENTER. EAST TO WEST UPPER LEVEL TROUGH TO THE WEST OF THIS SYSTEM WILL NOT BE A FAVORABLE ENVIRONMENT FOR TROPICAL DEVELOPMENT...BUT MAY HAVE A SHORT 12 TO 18 HOUR PERIOD TODAY TO FURTHER ORGANIZE AND ATTEMPT TO DEVELOP. LAST EVENINGS QUIKSCAT PASS SUGGESTED SURFACE TROUGHING WITH THE WAVE AXIS...AND NO EVIDENCE OVERNIGHT TO SUGGEST A SURFACE LOW. MORNING QUIKSCAT PASS WILL BE INTERESTING. DEEP CONVECTION AND SE SURFACE WINDS NEAR 25 KNOTS WILL CONTINUE TO AFFECT PORTIONS OF OUR LOCAL SW CARIB WATERS TODAY...AND SCA REMAINS IN EFFECT THERE. && .PRELIMINARY POINT TEMPS/POPS... SJU 86 77 88 77 / 70 50 50 40 STT 87 76 90 76 / 60 50 40 40 && .SJU WATCHES/ADVISORIES... PR...SCA AMZ740. VI...NONE. &&
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE SAN JUAN PR 600 AM AST WED JUL 21 2004 PRZ001>013-AMZ710>750-221000- 600 AM AST WED JUL 21 2004 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PUERTO RICO. .TODAY AND TONIGHT... THE VIGOROUS TROPICAL WAVE WHICH MOVED ACROSS PUERTO RICO YESTERDAY IS ENTERING THE CENTRAL CARIBBEAN THIS MORNING...AS IT MOVES WEST NORTHWEST AT 20 TO 25 MPH. EVEN THOUGH THIS WEATHER FEATURE HAS PASSED THE LOCAL AREA...LINGERING MOISTURE COMBINED WITH AN UNSTABLE ATMOSPHERE WILL SPARK THE DEVELOPMENT OF SCATTERED TO NUMEROUS SHOWERS AND SCATTERED THUNDERSTORMS TODAY. THE EASTERN AND SOUTHERN SECTIONS OF PUERTO RICO...CULEBRA...AND VIEQUES WILL MOSTLY BE AFFECTED THIS MORNING. BY AFTERNOON...SHOWER AND THUNDERSTORM ACTIVITY WILL BREAK OUT ISLAND WIDE...WITH THE POTENTIAL FOR HEAVY RAINS AND URBAN AND SMALL STREAM FLOODING. THERE EVEN EXISTS THE POSSIBILITY OF LOCALIZED FLASH FLOODING ACROSS THE SOUTHERN SLOPES AS WELL AS THE CENTRAL AND SOUTHEAST INTERIOR...WHERE 4 TO 5 INCH RAINFALL TOTALS ARE POSSIBLE. A SMALL CRAFT ADVISORY REMAINS IN EFFECT FOR THE CARIBBEAN OFFSHORE WATERS SOUTHWEST OF PUERTO RICO. WIND GUSTS NEAR SHOWERS AND THUNDERSTORMS OVER THIS AREA COULD EXCEED 35 KNOTS...CAUSING ROUGH AND CONFUSED SEAS. SMALL CRAFT SHOULD EXERCISE CAUTION ELSEWHERE UNTIL WINDS AND SEAS SUBSIDE. .SPOTTER CALL TO ACTION STATEMENT... SPOTTER ACTIVATION IS REQUESTED TODAY. .DAYS TWO THROUGH SEVEN... WEATHER CONDITIONS WILL BEGIN TO GRADUALLY IMPROVE BY THURSDAY. HOWEVER...UNSTABLE ATMOSPHERIC CONDITIONS AND ABUNDANT LOW LEVEL MOISTURE WILL COMBINE WITH DIURNAL EFFECTS TO PRODUCE SCATTERED TO LOCALLY NUMEROUS SHOWERS AND SCATTERED THUNDERSTORMS. EVEN THOUGH SHOWER AND THUNDERSTORM COVERAGE SHOULD BE LESS THAN THE PREVIOUS TWO DAYS...THE RISK FOR HEAVY RAIN AND URBAN AND SMALL STREAM FLOODING WILL CONTINUE. THE BEST CHANCE FOR THIS WILL LIE FROM THE CENTRAL INTERIOR TO THE WEST COAST. WINDS AND SEAS WILL CONTINUE TO GRADUALLY DIMINISH INTO THURSDAY...BUT SMALL CRAFT WILL STILL HAVE TO EXERCISE CAUTION. VIZ001-002-AMZ710>730-221000- 600 AM AST WED JUL 21 2004 THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE U.S. VIRGIN ISLANDS. .TODAY AND TONIGHT... THE VIGOROUS TROPICAL WAVE WHICH PASSED THE U.S. VIRGIN ISLANDS YESTERDAY WILL CONTINUE TO MOVE AWAY FROM THE LOCAL AREA TODAY. EVEN THOUGH THIS WEATHER SYSTEM HAS ALREADY PASSED...LINGERING MOISTURE AND UNSTABLE ATMOSPHERIC CONDITIONS WILL FAVOR THE DEVELOPMENT OF SCATTERED TO NUMEROUS SHOWERS AND SCATTERED THUNDERSTORMS OVER THE AREA THIS MORNING. THE RAINS ANTICIPATED THIS MORNING COULD LEAD TO LOCALIZED STREET FLOODING...BUT NO MAJOR FLOODING PROBLEMS ARE EXPECTED. BY AFTERNOON...THE BACK EDGE OF THE TROPICAL WAVE WILL BE NEARING THE REGION AND SHOWER AND THUNDERSTORM ACTIVITY SHOULD BEGIN TO TAPER OFF. SMALL CRAFT SHOULD CONTINUE TO EXERCISE CAUTION TODAY....AS WINDS WILL CONTINUE TO BE RATHER BRISK FROM THE SOUTHEAST. WINDS AND SEAS WILL GRADUALLY SUBSIDE THIS AFTERNOON AND TONIGHT. .SPOTTER CALL TO ACTION STATEMENT... SPOTTER ACTIVATION IS NOT ANTICIPATED TODAY. HOWEVER...SPOTTERS ARE URGED TO SELF ACTIVATE SHOULD WEATHER CONDITIONS WARRANT. .DAYS TWO THROUGH SEVEN... WEATHER CONDITIONS WILL CONTINUE TO IMPROVE INTO THURSDAY. LESS AVAILABLE MOISTURE WILL MEAN ISOLATED TO SCATTERED SHOWERS OVER THE LOCAL AREA...BUT NONE OF THESE IS EXPECTED TO LEAD TO FLOODING. 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. KIMBERLAIN
1 thunderstorm wind. Local standard time, as filed.
Several homes reported blown off zinc roofs. Small hail was reported in Aguadilla and Hatillo.
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, July 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: 5413772.