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 20, 3:36 PM AST, 1 hour 9 minutes earlier.
PUERTO RICO AND U.S. VIRGIN ISLANDS FORECAST DISCUSSION NATIONAL WEATHER SERVICE SAN JUAN PR 336 PM AST TUE JUL 20 2004 .SYNOPSIS...A TROPICAL WAVE IS MOVING TOWARD THE AREA AND WILL SPREAD SHOWERS AND THUNDERSTORM OVER THE ENTIRE FORECAST AREA. A THE AXIS OF A HIGH PRESSURE AT 250 MB IS SLIGHTLY NORTHWEST OF THE AREA AND IS CONTRIBUTING TO DIVERGENCE ALOFT. AT MID LEVELS HIGH PRESS IS NORTH OF THE AREA ACROSS FROM VIRGINIA. SEVERAL OTHER WAVES WILL ALSO MOVE THROUGH DURING THE UPCOMING 7 DAYS. && .DISCUSSION...THE TROPICAL WAVE HAS BEEN PULSING WITH CONVECTIVE ACTIVITY FOR AT LEAST 12 HOURS. ONE PULSE SPREAD NORTH OVER THE WINDWARD ISLANDS AND HAD GUSTY WINDS IN EXCESS OF 30 KNOTS. THIS PULSE DIED. A SECOND PULSE DEVELOPED SOUTHEAST OF THE AREA AND THUNDERSTORMS SPREAD OUT TO THE NORTHWEST WITH UNOFFICIAL GUSTS IN SAINT CROIX OF AT LEAST 57 KNOTS AND OFFICIALLY GUSTS OF 41 KNOTS AT THE AIRPORT IN CHRISTIANSTED. THIS SAME PULSE SHOULD REACH THE SHORES OF MAINLAND PUERTO RICO AROUND 4 OR 5 PM. OVER THE INTERIOR THUNDERSTORMS HAVE BEEN LIMITED TO THE WESTERN SECTION. ALTHOUGH INSTABILITY HAS BEEN HIGH...WINDS ARE ALSO STRONG 20 TO 30 KNOTS AND LOCAL EFFECTS ARE PARTIALLY OVERCOME. THUNDERSTORMS WILL LIKELY DIE OVER THE WEST AS THE SUN SETS. THE THUNDERSTORMS ON THE WAY FROM THE SOUTHEAST MAY NOT MAKE IT ENTIRELY ACROSS PUERTO RICO. LOOKING AHEAD...MOISTURE TAPERS OFF ONLY GRADUALLY DURING THE NEXT SEVERAL DAYS. A WET PERIOD IS BEING FORECAST BY THE GFS FOR SUNDAY AND A SECOND WAVE IS LOOKING TO MOVE IN ON MONDAY NIGHT OR TUESDAY. && .MARINE...SPECIAL MARINE WARNINGS HAVE BEEN ISSUED FOR CARIBBEAN WATERS FOR THE GUSTY WINDS...OTHERWISE SMALL CRAFT ADVISORIES WILL LIKELY APPLY TO ALL BUT THE WESTERN MARINE ZONE. SEAS ARE NOT EXPECTED TO BE ANY HIGHER IN THE NEXT 7 DAYS THAN THEY ARE DURING THIS 24 HOURS. && .PRELIMINARY POINT TEMPS/POPS... SJU 78 88 77 88 / 90 60 50 50 STT 77 89 76 90 / 90 60 50 40 && .SJU WATCHES/WARNINGS/ADVISORIES... PR...SCA...AMZ710>740. VI...SCA...AMZ720-730. && SNELL
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE SAN JUAN PR 600 AM AST TUE JUL 20 2004 PRZ001>013-AMZ710>750-211000- 600 AM AST TUE JUL 20 2004 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PUERTO RICO. .TODAY AND TONIGHT... A SURGE OF MOISTURE PASSING THROUGH PUERTO RICO EARLY THIS MORNING WILL SPARK SCATTERED TO NUMEROUS SHOWERS AND ISOLATED THUNDERSTORMS OVER THE ATLANTIC AND CARIBBEAN WATERS. WHILE THE MAJORITY OF THESE SHOULD STAY OFFSHORE...A NUMBER WILL MOVE INLAND...PRIMARILY AFFECTING NORTHERN AND EASTERN SECTIONS OF THE ISLAND. DIRECTLY BEHIND THE SURGE...THE LEADING EDGE OF A VIGOROUS TROPICAL WAVE WILL MOVE ACROSS THE U.S. VIRGIN ISLANDS BY MID MORNING AND ACROSS PUERTO RICO BY NOON...SETTING OFF A ROUND OF SCATTERED TO NUMEROUS SHOWERS AND SCATTERED THUNDERSTORMS. AS THE TROPICAL WAVE REACHES THE LOCAL AREA LATER THIS EVENING...AMPLE MOISTURE AND INSTABILITY ALONG WITH DAYTIME HEATING WILL SET THE STAGE FOR ADDITIONAL...NUMEROUS SHOWERS AND SCATTERED THUNDERSTORMS. MANY OF THESE STORMS WILL HAVE THE POTENTIAL FOR PRODUCING HEAVY RAINS ...WHICH COULD RESULT IN URBAN AND SMALL STREAM FLOODING AND LOCALIZED FLASH FLOODING. IN ADDITION...WINDS WILL BEGIN TO INCREASE OVER THE NEAR AND OFFSHORE WATERS THIS MORNING...BECOMING SIGNIFICANTLY STRONGER BY TONIGHT. IN ANTICIPATION OF THE INCREASING WIND...AS WELL AS THE ROUGH AND CONFUSED SEAS...SMALL CRAFT ADVISORIES HAVE BEEN ISSUED FOR THE OFFSHORE CARIBBEAN WATERS AND MAY BE REQUIRED ALL AREAS LATER TODAY. OF SPECIAL NOTE...SQUALLY WEATHER ASSOCIATED WITH THE TROPICAL WAVES PASSAGE MAY CAUSE WIND GUSTS OF 30 TO 40 MPH LATER AFTERNOON AND TONIGHT. .SPOTTER CALL TO ACTION STATEMENT... SPOTTER ACTIVATION IS REQUESTED. .DAYS TWO THROUGH SEVEN... THE STRONG TROPICAL WAVE WILL BE MOVING PAST THE LOCAL AREA BY EARLY WEDNESDAY...BUT AMPLE MOISTURE AND INSTABILITY WILL CAUSE NUMEROUS SHOWERS AND SCATTERED THUNDERSTORMS ACROSS THE LOCAL ISLANDS. THE RISK FOR LOCALLY HEAVY RAINFALL AND FLOODING WILL CONTINUE INTO THE AFTERNOON. IMPROVING WEATHER IS SLATED FOR THURSDAY THROUGH AT LEAST THE EARLY PART OF THE WEEKEND. STRONG...GUSTY WINDS WILL CONTINUE TO BE AN ISSUE INTO EARLY WEDNESDAY BEFORE DIMINISHING LATER IN THE DAY. VIZ001-002-AMZ710>730-211000- 600 AM AST TUE JUL 20 2004 THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE U.S. VIRGIN ISLANDS. .TODAY AND TONIGHT... THE LEADING EDGE OF A VIGOROUS TROPICAL WAVE WILL MOVE ACROSS THE U.S. VIRGIN ISLANDS BY MID MORNING...SETTING OFF A ROUND OF SCATTERED TO NUMEROUS SHOWERS AND SCATTERED THUNDERSTORMS. AS THE TROPICAL WAVE REACHES THE LOCAL AREA LATER THIS AFTERNOON...AMPLE MOISTURE AND INSTABILITY ALONG WITH DAYTIME HEATING WILL SET THE STAGE FOR ADDITIONAL...NUMEROUS SHOWERS AND SCATTERED THUNDERSTORMS. MANY OF THESE STORMS WILL HAVE THE POTENTIAL FOR PRODUCING HEAVY RAINS...WHICH COULD RESULT IN LOCALIZED URBAN FLOODING. IN ADDITION...WINDS WILL BEGIN TO INCREASE OVER THE NEAR AND OFFSHORE WATERS THIS MORNING...BECOMING SIGNIFICANTLY STRONGER BY THIS AFTERNOON. IN ANTICIPATION OF THE INCREASING WIND...AS WELL AS THE ROUGH AND CONFUSED SEAS...SMALL CRAFT ADVISORIES HAVE BEEN ISSUED FOR THE CARIBBEAN OFFSHORE WATERS AND MAY BE REQUIRED ALL AREAS LATER TODAY. OF SPECIAL NOTE...SQUALLY WEATHER ASSOCIATED WITH THE TROPICAL WAVES PASSAGE MAY CAUSE WIND GUSTS OF 30 TO 40 MPH THIS MORNING THROUGH TONIGHT. .SPOTTER CALL TO ACTION STATEMENT... SPOTTER ACTIVATION IS REQUESTED. .DAYS TWO THROUGH SEVEN... THE STRONG TROPICAL WAVE WILL HAVE MOVED PAST THE LOCAL AREA BY EARLY WEDNESDAY...BUT LINGERING MOISTURE AND INSTABILITY WILL CAUSE SCATTERED TO NUMEROUS SHOWERS AND ISOLATED THUNDERSTORMS ACROSS THE LOCAL ISLANDS DURING THE DAY WEDNESDAY. SOME LOCALLY HEAVY RAIN IS AGAIN POSSIBLE...WHICH COULD RESULT IN URBAN AND STREET FLOODING. IMPROVING WEATHER IS SLATED FOR WEDNESDAY NIGHT THROUGH AT LEAST THE EARLY PART OF THE WEEKEND. STRONG...GUSTY WINDS WILL CONTINUE TO BE AN ISSUE INTO EARLY WEDNESDAY BEFORE DIMINISHING LATER IN THE DAY. 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
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE SAN JUAN PR 312 PM AST TUE JUL 20 2004 VIZ001-202030- ST. THOMAS...ST. JOHN... AND ADJACENT ISLANDS- 308 PM AST TUE JUL 20 2004 THUNDERSTORMS ASSOCIATED WITH A LINE THAT HAS BEGUN IN THE TROPICAL WAVE APPROACHING THE AREA WILL MOVE ACROSS THE NORTHERN VIRGIN ISLANDS BETWEEN 3:15 AND 3:30 PM. THIS LINE OF THUNDERSTORMS HAS PRODUCED WINDS IN EXCESS OF 50 KNOTS BUT SHOULD ONLY APPROACH SEVERE LEVELS BY THE TIME THAT IT REACHES SAINT THOMAS AND SAINT JOHN. EXPECT HEAVY RAINFALL...FREQUENT LIGHTNING AND VERY GUSTY WINDS UNTIL ABOUT 4:30 PM. SNELL
SPECIAL WEATHER STATEMENT...CORRECTION TO ADD VIEQUES AND CULEBRA NATIONAL WEATHER SERVICE SAN JUAN PR 312 PM AST TUE JUL 20 2004 PRZ012-013-VIZ001-202030- ST. THOMAS...ST. JOHN... AND ADJACENT ISLANDS- 308 PM AST TUE JUL 20 2004 ...STRONG THUNDERSTORMS ENTERING THE VIRGIN ISLANDS... THUNDERSTORMS ASSOCIATED WITH A LINE THAT HAS BEGUN IN THE TROPICAL WAVE APPROACHING THE AREA WILL MOVE ACROSS THE NORTHERN VIRGIN ISLANDS...VIEQUES AND CULEBRA BETWEEN 3:15 AND 3:30 PM. THIS LINE OF THUNDERSTORMS HAS PRODUCED WINDS IN EXCESS OF 50 KNOTS BUT SHOULD ONLY APPROACH SEVERE LEVELS BY THE TIME THAT IT REACHES SAINT THOMAS AND SAINT JOHN...VIEQUES AND CULEBRA. EXPECT HEAVY RAINFALL...FREQUENT LIGHTNING AND VERY GUSTY WINDS UNTIL ABOUT 4:30 PM. SNELL
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE SAN JUAN PR 336 PM AST TUE JUL 20 2004 PRZ002>004-202045- NORTHEAST- SOUTHEAST- EASTERN INTERIOR- 342 PM AST TUE JUL 20 2004 STRONG THUNDERSTORMS ARE MOVING DIRECTLY TOWARD THE SOUTHEAST COAST OF PUERTO RICO AND WILL MOVE ONSHORE BEFORE 3:50 PM. THESE THUNDERSTORMS WILL CONTAIN GUSTY WINDS AS STRONG AS 45 KNOTS...VERY HEAVY RAIN AND FREQUENT LIGHTNING. PERSONS IN THE AREA SHOULD MOVE TO BUILDINGS THAT WILL PROTECT THEM FROM LIGHTNING AND HEAVY RAIN. THOSE DRIVING SHOULD BE ALLOW FOR VERY POOR DRIVING CONDITIONS INCLUDING LOW VISIBILITIES AND PONDING OF WATER IN THE ROADWAYS. SNELL
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE SAN JUAN PR 406 PM AST TUE JUL 20 2004 PRZ001>004-006-007-202115- SAN JUAN AND VICINITY- NORTHEAST- PONCE AND VICINITY- SOUTHEAST- CENTRAL INTERIOR- EASTERN INTERIOR- 406 PM AST TUE JUL 20 2004 A LINE OF THUNDERSTORMS GENERATED AHEAD OF THE TROPICAL WAVE MOVING TOWARD THE AREA IS SPREADING HEAVY RAIN...WINDS WITH GUSTS AS HIGH AS 45 KNOTS AND FREQUENT LIGHTNING ACROSS THE AREA. THIS LINE IS MOVING BETWEEN 25 AND 30 KNOTS TOWARD THE NORTHWEST AND WILL BE MOVING INTO THE SAN JUAN METRO AREA BEFORE 5 PM AST. PERSONS IN THE AREA SHOULD SEEK SHELTER FROM THE LIGHTNING...WINDS AND HEAVY RAIN IN A SUITABLE BUILDING. PRACTICE LIGHTNING SAFETY. SHOWERS WILL CONTINUE IN THE AREA OVERNIGHT...SOME OF THE RAIN WILL BE HEAVY. SNELL
1 thunderstorm wind. Local standard time, as filed.
Broken tree branches were reported at Sierra Bayamon as a line of thunderstorms ahead of a tropical wave produced strong gusty winds.
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: 5413771.