A cold front affected Puerto Rico March 21-22, while a shear line behind the front was responsible for the heavy rain that felt across the area on the 23rd of March. During this period, heavy rain and urban and small stream flooding was reported mainly across the northeast and eastern interior 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.
A cold front affected Puerto Rico March 21-22, while a shear line behind the front was responsible for the heavy rain that felt across the area on the 23rd of March. During this period, heavy rain and urban and small stream flooding was reported mainly across the northeast and eastern interior 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 Mar 21, 11:55 AM AST, 4 hours 29 minutes earlier.
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
1155 AM AST SAT MAR 21 2009
.UPDATE...LATEST TJSJ 12Z SOUNDING SHOWED LIGHT WINDS FROM THE
SURFACE UP TO 6K FEET...SHIFTING WEST ABOVE THIS LEVEL. DUE TO
THIS...MADE MINOR CHANGES TO MAXIMUM TEMPERATURES GRIDS TO ADJUST
VALUES SOME DEGREES UP ACROSS THE SAN JUAN METRO AREA. FOR THIS
AFTERNOON...SCATTERED SHOWERS ARE EXPECTED OVER THE WESTERN
INTERIOR...NORTHWEST AND NORTH CENTRAL SECTIONS OF PUERTO RICO.
MARINE WISE...BUOY 41043 WAS SHOWING 5 TO 7 FEET SWELLS AT 14
SECONDS. THEREFORE...A HIGH SURF ADVISORY HAS BEEN ISSUED FOR THE
NORTHWEST THROUGH NORTHEAST COASTS OF PUERTO RICO...CULEBRA AND
VIEQUES...AND FOR ST THOMAS...ST JOHN AND THE ADJACENT SMALLER
ISLANDS IN THE U.S. VIRGIN ISLANDS...WHICH IS IN EFFECT UNTIL 6 PM
AST SUNDAY. NO OTHER CHANGES WERE MADE TO PREVIOUS FORECAST.
&&
.AVIATION...VFR CONDITIONS ARE EXPECTED ACROSS MOST TAF SITES THIS
AFTERNOON. BRIEF PERIODS OF MVFR CONDITIONS ARE EXPECTED ACROSS
TJMZ...AND TJBQ LATER THIS AFTERNOON.
&&
.PREV DISCUSSION... /ISSUED 507 AM AST SAT MAR 21 2009/
SYNOPSIS...LOW PRES OVR THE WRN ATLC WILL DRAG A PREFRONTAL
TROUGH THROUGH THE AREA ON SUN. A COLD FRONT WILL THEN SLOWLY MOVE
THROUGH THE AREA ON TUE. SEVERAL DAYS OF WET WEATHER ARE
ANTICIPATED TODAY THROUGH TUE. HIGH PRES WILL BUILD FOR THE LATTER
PART OF NEXT WEEK BRINGING A RETURN TO DRY WEATHER.
DISCUSSION...MOISTURE ALREADY ON THE INCREASE EARLY THIS MORNING AS
INDICATED BY SEVERAL MICROWAVE SENSORS WITH PWAT VALUES RANGING
FROM 1.35 TO 1.6 INCHES WHICH IS ABOUT 90 TO 130% OF NORMAL FOR
THIS TIME OF THE YEAR. EXPECT SCT CONVECTION TO DEVELOP OVR THE
WRN HALF OF PR IN COMBINATION WITH DAYTIME HEATING AND SEA BREEZE
CONVERGENCE.
SUN LOOKS TO BE A BIT MORE ACTIVE AS A SHEARLINE MOVES THROUGH THE
AREA. MOISTURE...ALTHOUGH RESPECTABLE IS NOT THAT ALL IMPRESSIVE
FOR THIS TIME OF THE YEAR. HOWEVER...LOCALIZED FLOODING NOT OUT OF
THE QUESTION GIVEN EXPECTED WEAK STEERING FLOW. THUNDERSTORMS ALSO
POSSIBLE.
BY SUN NIGHT...WINDS TURN MORE NORTHERLY WHICH SHOULD HELP FOCUS
SHRAS ACROSS THE NORTHERN SLOPES OF PR. ACTUAL CDFNT LOOKS TO
SLOWLY MOVE THROUGH THE AREA ON TUE...SO UNTIL THEN EXPECT SCT TO
NMRS SHRAS MAINLY OVR THE NORTHERN SLOPES AND NORTHEAST PR. DEEP
MOISTURE IS SHUNTED SOUTH OF THE AREA ON WED SO AM ANTICIPATING A
MARKED DECREASE IN SHRA CVRG.
HIGH PRES BUILDS FOR THE END OF NEXT WEEK WITH DEEP DRY AIR TAKING
HOLD OVR THE NORTHEAST CARIBBEAN.
AVIATION...PREVAILING VFR CONDITIONS ARE EXPECTED ACROSS ALL THE
TAF SITES AND THE LOCAL FLYING AREA THIS MORNING THROUGH LATE TODAY.
DURING THE AFTERNOON...LOCAL SEA BREEZE VARIATIONS WILL AFFECT THE
COASTAL AREAS BTWN 14-22Z...WITH AFTERNOON SHOWER DEVELOPMENT
POSSIBLE ACROSS THE NORTH CENTRAL INTERIOR SECTION AND NORTH CENTRAL
COASTAL MUNICIPALITIES OF PUERTO RICO. WINDS WILL BE LIGHT FOR MUCH
OF THIS MORNING...BUT AFTERWARD...EXPECT A GENTLE TO MODERATE EAST
SOUTHEASTERLY FLOW ACROSS MUCH OF THE AREA.
MARINE...SEAS WILL BUILD TO 9 FT ACROSS THE ATLC TODAY AND
TONIGHT AND THEN DECREASE A BIT SUN AND SUN NIGHT BUT ONLY TO
INCREASE AGAIN TO NEAR 10 FEET TUE AND REMAIN LIKE THAT THROUGH
THE END OF THE NEXT WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
SJU 86 72 83 71 / 40 40 50 30
STT 83 72 82 70 / 10 40 20 30
&&
.SJU WATCHES/WARNINGS/ADVISORIES...
PR...HIGH SURF ADVISORY UNTIL 6 PM AST SUNDAY FOR CULEBRA-MAYAGUEZ
AND VICINITY-NORTH CENTRAL-NORTHEAST-NORTHWEST-SAN JUAN AND
VICINITY-VIEQUES.
VI...HIGH SURF ADVISORY UNTIL 6 PM AST SUNDAY FOR ST. THOMAS/ST.
JOHN/ADJACENT ISLANDS.
&&
71/06/HAZARDOUS WEATHER OUTLOOK FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS NATIONAL WEATHER SERVICE SAN JUAN PR 1149 AM AST SAT MAR 21 2009 AMZ710>745-PRZ001>013-221600- 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- 1149 AM AST SAT MAR 21 2009 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PUERTO RICO AND THE ADJACENT COASTAL WATERS. .DAY ONE...THIS AFTERNOON AND TONIGHT MODERATE...LONG PERIOD NORTH NORTHEAST SWELLS BEGAN TO AFFECT THE ATLANTIC WATERS AND THE CARIBBEAN PASSAGES FRIDAY AFTERNOON AND EVENING AND HAVE CONTINUED TO BUILD OVERNIGHT THROUGH LATE THIS SATURDAY MORNING. THESE 5 TO 6 FOOT SWELLS WILL CONTINUE TO AFFECT THESE WATERS THROUGH AT LEAST TONIGHT AND WILL RESULT IN DANGEROUS SURF CONDITIONS...WITH RIP CURRENTS AND LARGE BREAKING WAVES OF 10 TO 14 FEET AND LOCALLY HIGHER ALONG THE LOCAL REEFS... BEACHES AND SHOALS OF THE NORTHWEST THROUGH NORTHEAST COASTS OF THE LOCAL ISLANDS. A HIGH SURF ADVISORY HAS BEEN ISSUED FOR THE NORTHWEST THROUGH NORTHEAST COASTS OF ALL OF THE LOCAL ISLANDS. .DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY A FRONTAL BOUNDARY WILL APPROACH THE AREA LATE SUNDAY INTO MONDAY INCREASING THE CHANCES OF RAINFALL AND LOCALIZED FLOODING. IN ADDITION...ROUGH AND HAZARDOUS MARINE AND SURF CONDITIONS WILL CONTINUE ACROSS THE ATLANTIC WATERS AND CARIBBEAN PASSAGES THROUGH AT LEAST WEDNESDAY. EXPECT SMALL CRAFT AND HIGH SURF ADVISORIES THROUGH THE PERIOD. PLEASE STAY TUNED TO THE NATIONAL WEATHER SERVICE FOR FURTHER UPDATES. .SPOTTER INFORMATION STATEMENT... REPORTS OF LARGE BREAKING WAVES AND DANGEROUS SURF WOULD BE GREATLY APPRECIATED. AMZ715-725-VIZ001-002-221600- ST. THOMAS ST. JOHN ADJACENT ISLANDS-ST CROIX- NEARSHORE ATLANTIC AND ADJACENT CARIBBEAN COASTAL WATERS- 1149 AM AST SAT MAR 21 2009 THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE U.S. VIRGIN ISLANDS AND THE ADJACENT COASTAL WATERS. .DAY ONE...THIS AFTERNOON AND TONIGHT MODERATE...LONG PERIOD NORTH NORTHEAST SWELLS BEGAN TO AFFECT THE ATLANTIC WATERS AND THE CARIBBEAN PASSAGES FRIDAY AFTERNOON AND EVENING AND HAVE CONTINUED TO BUILD OVERNIGHT THROUGH LATE THIS SATURDAY MORNING. THESE 5 TO 6 FOOT SWELLS WILL CONTINUE TO AFFECT THESE WATERS THROUGH AT LEAST TONIGHT AND WILL RESULT IN DANGEROUS SURF CONDITIONS...WITH RIP CURRENTS AND LARGE BREAKING WAVES OF 10 TO 14 FEET AND LOCALLY HIGHER ALONG THE LOCAL REEFS... BEACHES AND SHOALS OF THE NORTHWEST THROUGH NORTHEAST COASTS OF MOST OF THE LOCAL ISLANDS. A HIGH SURF ADVISORY HAS BEEN ISSUED FOR THE NORTHWEST THROUGH NORTHEAST COASTS OF ST THOMAS...ST JOHN AND THE ADJACENT SMALLER ISLANDS. .DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY A FRONTAL BOUNDARY WILL APPROACH THE AREA LATE SUNDAY INTO MONDAY INCREASING THE CHANCES OF RAINFALL AND LOCALIZED FLOODING. IN ADDITION...ROUGH AND HAZARDOUS MARINE AND SURF CONDITIONS WILL CONTINUE ACROSS THE ATLANTIC WATERS AND CARIBBEAN PASSAGES THROUGH AT LEAST WEDNESDAY. EXPECT SMALL CRAFT AND HIGH SURF ADVISORIES THROUGH THE PERIOD. PLEASE STAY TUNED TO THE NATIONAL WEATHER SERVICE FOR FURTHER UPDATES. .SPOTTER INFORMATION STATEMENT... REPORTS OF LARGE BREAKING WAVES AND DANGEROUS SURF WOULD BE GREATLY APPRECIATED.
The national radar mosaic for the moment the first event began.
2 heavy rain, 1 debris flow. Local standard time, as filed.
A mudslide was reported at km 34.4 of Highway 155 in Barrio El Gato, 4 miles north of Orocovis municipality. One home was damaged.
A segment of road 9936 was reported flooded at Estancias neigborhood in the municipality of Las Piedras.
Heavy rain and poor drainage led to partial flooding of road 132.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Puerto Rico in 2009Every state in 2009This day in weather historyWarnings in Puerto Rico, March 2009
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: 151409, 160977, 159728.