An upper level trough combined with strong daytime heating and orographic effects to produce scattered to numerous showers with thunderstorms over the south, interior, and southwest sections of Puerto Rico.
Every event with a place to put it. Tap one for its entry below.
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 episode as NWS SJU wrote it up.
An upper level trough combined with strong daytime heating and orographic effects to produce scattered to numerous showers with thunderstorms over the south, interior, and southwest sections of Puerto Rico.
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 12, 11:35 AM AST, 25 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SAN JUAN PR 1135 AM AST THU JUL 12 2012 .UPDATE...THE DOPPLER WEATHER RADAR DETECTED SCATTERED SHOWERS AND A FEW THUNDERSTORMS NORTH OF CORDILLERA CENTRAL THIS MORNING AS WELL AS ACROSS THE SURROUNDING COASTAL WATERS. THIS ACTIVITY WAS THE RESULT OF A MOIST EAST NORTHEAST LOW LEVEL WIND FLOW ASSOCIATED WITH A TUTT LOW JUST NORTH NORTHEAST OF THE LOCAL ISLANDS. THIS MOISTURE WILL COMBINE WITH DAYTIME HEATING AND LOCAL OROGRAPHIC EFFECTS THIS AFTERNOON TO INDUCE THE DEVELOPMENT OF SCATTERED SHOWERS AND THUNDERSTORMS MAINLY ACROSS WESTERN PORTIONS OF PUERTO RICO. THIS ACTIVITY IS EXPECTED TO LINGER UNTIL THE EVENING HOURS. THE TUTT LOW AND THE ASSOCIATED TROUGH ARE EXPECTED TO DRIFT SLOWLY WESTWARD DURING THE NEXT FEW DAYS. THESE FEATURES WILL SUPPLY FUEL FOR SEVERAL ROUND OF SHOWERS AND THUNDERSTORMS UNTIL AT LEAST SATURDAY. THIS WETTER PATTERN ARE EXPECTED THROUGH AT LEAST SUNDAY AS THE INDUCED TROUGH MOVES ACROSS THE AREA THROUGH FRIDAY...FOLLOWED BY THE NEXT TROPICAL WAVE DURING THE UPCOMING WEEKEND. THIS WILL RESULT IN SEVERAL ROUNDS OF SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ACROSS THE LOCAL ISLANDS. OVERALL...LOOKS LIKE THE MOST ACTIVE DAYS WILL BE FRIDAY AND SUNDAY. && .AVIATION...PATCHES OF MOISTURE EMBEDDED IN A EAST NORTHEAST TRADE WIND FLOW WILL CONTINUE TO AFFECT THE LOCAL ISLANDS FROM TIME TO TIME THROUGH AT LEAST THE NEXT 24 HOURS. AS A RESULT... TJSJ/TJBQ...TIST/TISX...TNCM AND TKPK WILL BE EXPERIENCING VCSH AND -SHRA EARLY IN THE AFTERNOON. BTWN 12/17Z AND 12/21Z TSRA WILL BE POSSIBLE IN AND AROUND TJPS AND TJMZ...CAPABLE OF PRODUCING MVFR/IFR CONDITIONS AND MTN OBSCURATIONS NEAR THESE TAF SITES. WIND IS EXPECTED TO BE EAST NORTHEAST AT 10 TO 20 KTS WITH HIGHER GUSTS NEAR SHRA/TSRA. && .PREV DISCUSSION... /ISSUED 538 AM AST THU JUL 12 2012/ SYNOPSIS...A TUTT LOW NORTHEAST OF THE LOCAL AREA THIS MORNING... WILL CONTINUE MOVING WEST THE NEXT COUPLE OF DAYS WITH A BROAD LOW TO MID LEVEL REFLECTION PASSING ACROSS THE FA THIS AFTERNOON THROUGH FRIDAY. AN TUTT INDUCED PERTURBATION WILL THEN AFFECT THE LOCAL AREA SATURDAY FOLLOWED BY A TROPICAL WAVE SUNDAY. DISCUSSION...ALTHOUGH IT WILL NOT BE CLOUDY AND RAINY ALL THE TIME...AN INCREASINGLY UNSETTLED SPELL OF WEATHER APPEARS ON TAP FOR THE FA DURING THE NEXT SEVERAL DAYS. FOR TODAY THROUGH FRIDAY...AS AFOREMENTIONED TUTT PASSES BY TO OUR NORTH AND BROAD LOW TO MID LEVEL REFLECTION MOVES ACROSS THE FA...THESE FEATURES AND ASSOCIATED MOISTURE WILL COMBINE WITH LOCAL EFFECTS...TO PRODUCE AREAS OF CLOUDINESS...SCATTERED TO NUMEROUS SHOWERS AND ISOLATED THUNDERSTORMS OVER PARTS OF THE LOCAL ISLANDS...WITH THE BEST DYNAMICS EXPECTED FOR FRIDAY. THEREAFTER...THE FORECAST BECOMES A BIT TRICKY...ESPECIALLY WHEN TRYING TO COMPARE LATEST OBSERVED DATA WITH MODEL PROJECTIONS AND RESULTANT TIMING OF FEATURES. THAT SAID...WE EXPECT A TUTT INDUCED PERTURBATION ALONG 51 DEGREES WEST EARLY THIS MORNING TO MOVE ACROSS THE LOCAL AREA SATURDAY...FOLLOWED BY A TROPICAL WAVE CURRENTLY NEAR 43 DEGREES PASSING ACROSS THE FA SUNDAY. THESE TWO FEATURES AND PARTICULARLY THE TIMING OF SUBSIDENCE INDUCED DRY SLOTS VERSUS THE BEST AREAS OF MOISTURE AND HENCE THE BEST CHANCES OF ACTIVE WEATHER...WILL NEED TO BE FOLLOWED CLOSELY THE NEXT COUPLE OF DAYS. THUS...EXPECT ADJUSTMENTS TO MODEL SOLUTIONS AND SUBSEQUENTLY CHANGES TO LOCAL GRIDS AND FORECASTS TO BE FORTHCOMING DURING THE NEXT 24 TO 48 HOURS...AS THE WEEKEND FORECAST IS FINE TUNED. AVIATION...PATCHES OF MOISTURE EMBEDDED IN A NORTHEASTERLY TRADE WIND FLOW WILL CONTINUE TO AFFECT THE LOCAL ISLANDS FROM TIME TO TIME THROUGH AT LEAST THE NEXT 24 HOURS. AS A RESULT... TJSJ/TJBQ...TIST/TISX...TNCM AND TKPK WILL BE EXPERIENCING VCSH AND -SHRA IN THE MORNING HOURS. BTWN 12/17Z AND 12/21Z TSRA WILL BE POSSIBLE IN AND AROUND TJPS AND TJMZ...CAPABLE OF PRODUCING MVFR/IFR CONDITIONS AND MTN OBSCURATIONS NEAR THESE TAF SITES. WIND IS EXPECTED TO BE NORTHEAST AT 10 TO 20 KTS WITH HIGHER GUSTS NEAR SHRA/TSRA. MARINE...GENERALLY EXPECT WINDS OF 18 KNOTS OR LESS AND SEAS OF 6 FEET OR LESS ACROSS THE REGIONAL WATERS THROUGH AT LEAST SATURDAY. SMALL BOAT OPERATORS SHOULD EXERCISE CAUTION ACROSS PARTS OF THE LOCAL COASTAL WATERS TODAY. && .PRELIMINARY POINT TEMPS/POPS... SJU 89 76 88 77 / 30 30 40 20 STT 88 78 90 80 / 30 40 40 30 && .SJU WATCHES/WARNINGS/ADVISORIES... PR...NONE. VI...NONE. COASTAL WATERS...NONE. && 72/71
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE SAN JUAN PR 619 AM AST THU JUL 12 2012 AMZ710>745-PRZ001>013-131030- SAN JUAN AND VICINITY-NORTHEAST-SOUTHEAST-EASTERN INTERIOR- NORTH CENTRAL-CENTRAL INTERIOR-PONCE AND VICINITY-NORTHWEST- WESTERN INTERIOR-MAYAGUEZ AND VICINITY-SOUTHWEST-CULEBRA-VIEQUES- THE NEARSHORE AND OFF SHORE ATLANTIC AND CARIBBEAN COASTAL WATERS- 619 AM AST THU JUL 12 2012 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PUERTO RICO AND THE ADJACENT ATLANTIC COASTAL WATERS. .DAY ONE...TODAY AND TONIGHT WETTER CONDITIONS ARE EXPECTED TODAY...AS AN INDUCED TROUGH APPROACHES TO THE LOCAL AREA. THIS WILL RESULT IN SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ACROSS PARTS OF THE ISLANDS. SOME RAINS COULD BE LOCALLY HEAVY AND MAY INDUCE URBAN AND SMALL STREAM FLOODING. .DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY UNSETTLED WEATHER CONDITIONS ARE EXPECTED TO CONTINUE THROUGH AT LEAST SUNDAY...AS AN INDUCED TROUGH MOVES ACROSS THE AREA FRIDAY... FOLLOWED BY A TROPICAL WAVE DURING THE WEEKEND. THIS WILL RESULT IN SEVERAL ROUNDS OF SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ACROSS THE LOCAL ISLANDS. SOME RAINS COULD BE LOCALLY HEAVY AND MAY INDUCE URBAN AND SMALL STREAM FLOODING. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT ANTICIPATED...HOWEVER INDIVIDUAL SPOTTERS ARE ENCOURAGED TO REPORT FLOODING AND ANY STRONG THUNDERSTORMS TO THE NATIONAL WEATHER SERVICE OFFICE SAN JUAN. AMZ715-725-VIZ001-002-131030- ST. THOMAS ST. JOHN ADJACENT ISLANDS-ST CROIX- NEARSHORE ATLANTIC AND ADJACENT CARIBBEAN COASTAL WATERS- 619 AM AST THU JUL 12 2012 THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE U.S. VIRGIN ISLANDS AND THE ADJACENT COASTAL WATERS. .DAY ONE...TODAY AND TONIGHT WETTER CONDITIONS ARE EXPECTED TODAY...AS AN INDUCED TROUGH APPROACHES TO THE LOCAL AREA. THIS WILL RESULT IN SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ACROSS PARTS OF THE ISLANDS. SOME RAINS COULD BE LOCALLY HEAVY AND MAY INDUCE URBAN AND GUT FLOODING. .DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY UNSETTLED WEATHER CONDITIONS ARE EXPECTED TO CONTINUE THROUGH AT LEAST SUNDAY AS AN INDUCED TROUGH MOVES ACROSS THE AREA FRIDAY... FOLLOWED BY A TROPICAL WAVE DURING THE WEEKEND. THIS WILL RESULT IN SEVERAL ROUNDS OF SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ACROSS THE LOCAL ISLANDS. SOME RAINS COULD BE LOCALLY HEAVY AND MAY INDUCE URBAN AND GUT FLOODING. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT ANTICIPATED...HOWEVER INDIVIDUAL SPOTTERS ARE ENCOURAGED TO REPORT FLOODING AND ANY STRONG THUNDERSTORMS TO THE NATIONAL WEATHER SERVICE OFFICE SAN JUAN.
The national radar mosaic for the moment the first event began.
1 flood. Local standard time, as filed.
Seven teenagers were rescued at Jurutungo sector, Barrio Real An n due to surge of water in a creek in the municipality of Ponce.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Puerto Rico in 2012Every state in 2012This day in weather historyWarnings in Puerto Rico, July 2012
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: 405133.