An upper level trough located west of Puerto Rico, combined with daytime heating and available moisture, to produce numerous showers, and heavy rain across the municipalities of Guaynabo, Bayamon and some urban areas of San Juan.
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 located west of Puerto Rico, combined with daytime heating and available moisture, to produce numerous showers, and heavy rain across the municipalities of Guaynabo, Bayamon and some urban areas of San Juan.
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 Feb 27, 10:55 AM AST, 4 hours 50 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SAN JUAN PR 1055 AM AST FRI FEB 27 2009 ISSUED BY NATIONAL WEATHER SERVICE MIAMI FL .UPDATE... LATEST SURFACE ANALYSIS CONTINUES TO SHOW FRONTAL STROUGH ACROSS THE ATLANTIC FROM JUST NORTH OF HISPANIOLA NORTHEASTWARD ACROSS THE ATLANTIC EMBEDDED IN LARGE SCALE RIDGE ACROSS THE NORTH ATLANTIC. UPR LVL ANALYSIS AND WATER VAPOR LOOP SHOW AXIS OF BROAD TROUGH TO THE WEST OF THE CWA WITH STRONG UPR LVL SWLY FLOW ACROSS THE ISLANDS. 12Z SNDG SHOWS MODERATE EASTERLY FLOW THROUGH 6 KFT ON THE SOUTH SIDE OF THE RIDGE TO THE NORTH. ALTHOUGH THE SNDG SHOWS COLD MID LEVELS OF AROUND -9...LOW AND MID LEVEL LAPSE RATES ARE CLOSE TO MOIST ADIABATIC AND THIS IS REFLECTED IN A MODIFIED SURFACE BASED CAPE OF JUST AROUND 1000 J/KG. AMSU/CIRA PWAT PRODUCT SHOWS VALUES OF AROUND 1.3 INCHES ACROSS THE ISLANDS ON THE EASTERN SIDE OF UPR LEVEL TROUGH WHICH IS BARELY ABOVE NORMAL FOR THIS TIME OF THE YEAR. THIS ALL MEANS THAT WITH ENOUGH SUNSHINE TODAY...INSTABILITY SHOULD BE ENOUGH FOR ORGRAPHIC FORCING AND SEAS BREEZE INTERACTIONS TO RESULT IN NUMEROUS AFTERNOON SHOWERS AND PERHAPS A FEW THUNDERSTORMS ACROSS THE WEST INTERIOR PORTIONS OF PR. GIVEN MODERATE EASTERLY FLOW AT LOW LEVELS...MAIN FOCUS SHOULD BE SLIGHT SOUTH OF CURRENT GRID DEPICTION SO ADJUSTED GRIDS ACCORDINGLY. OTHER THAN THAT...NO OTHER UPDATES PLANNED AT THIS TIME. && .PREV DISCUSSION... /ISSUED 505 AM AST FRI FEB 27 2009/ DISCUSSION...PATCHES OF LOW LEVEL MOISTURE ACROSS THE NORTHERN LEEWARD ISLANDS THIS MORNING...WILL CONTINUE TO TRACK WESTWARD AND WILL REACH THE LOCAL ISLANDS TODAY. THESE PATCHES OF MOISTURE IN COMBINATION WITH DAYTIME HEATING...LOCAL TERRAIN EFFECTS AND SEA BREEZE VARIATIONS WILL ENHANCE THE SHOWERS AND THUNDERSTORMS ACTIVITY ESPECIALLY ACROSS WESTERN AND INTERIOR SECTIONS OF PUERTO RICO THIS AFTERNOON. THIS ACTIVITY WILL LINGER ACROSS THOSE SECTIONS OF THE ISLAND UNTIL THE EVENING HOURS. NO SIGNIFICANT PCPN IS EXPECTED ELSEWHERE ACROSS THE FA TODAY. BOTH THE GFS AND THE NAM MODELS SUGGEST A LITTLE MORE WET WEATHER PATTERN ACROSS THE FA DURING THE UPCOMING WEEKEND. UPPER LEVEL DYNAMIC WILL ALSO CONTINUE FAVORABLE FOR THE DEVELOPMENT OF THUNDERSTORMS ACROSS THE REGION DURING THE NEXT FEW DAYS. LATEST TJSJ 00Z SOUNDING INDICATED A SOUTHWEST WIND FLOW UP TO 70 KNOTS ABOVE 25K FEET...BUT THE LATEST RUN OF THE GFS MODEL GUIDANCE INDICATED AN UPPER JET...ORIENTED FROM SOUTHWEST TO NORTHEAST...NORTH OF THE REGION...WITH WINDS UP TO 100 KNOTS. THE GFS SUGGESTS THAT THIS UPPER JET WILL CONTINUE VERY CLOSE OR JUST OVER THE LOCAL ISLANDS FOR THE NEXT SEVERAL DAYS. A STATIONARY AND WEAKENING FRONTAL TROUGH EXTENDS FROM WESTERN HISPANIOLA EAST NORTHEASTWARD ACROSS THE CENTRAL ATLANTIC THIS MORNING. THE MOISTURE ASSOCIATED WITH THIS FEATURE WILL LINGER ACROSS THE ATLANTIC COASTAL WATERS...NORTH OF THE LOCAL ISLANDS FOR THE NEXT FEW DAYS. LOOKING WELL AHEAD...A WEAK COLD FRONT WILL APPROACH TO THE FA BY THE MIDDLE OF THE UPCOMING WEEK. GFS SUGGESTS THAT THE LOW LEVEL CONVERGENCE ZONE ASSOCIATED WITH THIS FRONT...WILL BE JUST OVER PUERTO RICO LATE WEDNESDAY/EARLY THURSDAY. AVIATION...PREVAILING VFR CONDITIONS ARE EXPECTED ACROSS ALL THE TAF SITES THROUGH 16Z FRIDAY. PASSING LOW LEVEL CLOUDS AND -SHRA MAY BRING TEMPORARY MVFR MAINLY AROUND TIST AND TJSJ DURING THE EARLY MORNING HOURS...BUT NO SIGNIFICANT AVIATION IMPACTS ARE EXPECTED AS A RESULT. FOR THE REST OF THE DAY...EXPECT ANOTHER ROUND OF AFTERNOON CONVECTION OVER PARTS OF THE CORDILLERA CENTRAL AND WESTERN SECTIONS OF PR...WITH TOPS TO AROUND 30KFT ALONG WITH MVFR CIGS AND TEMPO MVFR VSBYS...ESPECIALLY ACROSS TJMZ AND TJBQ BETWEEN 17-22Z. MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS CONTINUE IN EFFECT THROUGH SATURDAY AFTERNOON ACROSS THE OFFSHORE ATLANTIC COASTAL WATERS. FOR THE REMAINDER OF THE LOCAL AREA WATERS...SMALL CRAFTS SHOULD EXERCISE CAUTION...WITH THE EXCEPTION OF THE NEAR SHORE SOUTHERN AND WESTERN COASTAL WATERS OF PUERTO RICO...WHERE TRANQUIL SEAS CONDITIONS WILL PERSIST THROUGH THE WEEKEND. && .PRELIMINARY POINT TEMPS/POPS... SJU 84 72 85 73 / 20 30 30 20 STT 82 72 82 72 / 30 30 30 20 && .SJU WATCHES/WARNINGS/ADVISORIES... PR...NONE. VI...NONE. && 99/99/
HAZARDOUS WEATHER OUTLOOK FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS NATIONAL WEATHER SERVICE SAN JUAN PR 556 AM AST FRI FEB 27 2009 AMZ710>745-PRZ001>013-281000- 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- 556 AM AST FRI FEB 27 2009 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PUERTO RICO AND THE ADJACENT COASTAL WATERS. .DAY ONE...TODAY AND TONIGHT FAVORABLE MID TO UPPER LEVEL TROUGHING ACROSS THE AREA WILL ENHANCE SHOWER ACTIVITY DURING THE AFTERNOON MAINLY ACROSS PARTS OF THE NORTH CENTRAL INTERIOR AND THE WESTERN SECTIONS OF THE ISLAND. MODERATE TO LOCALLY HEAVY SHOWERS AND ISOLATED THUNDERSTORMS ARE POSSIBLE ACROSS THESE AREAS. MINOR LOCAL FLOODING ARE THEREFORE POSSIBLE ALONG SMALL RIVER AND STREAMS...STREETS...HIGHWAYS...UNDERPASES...AS WELL AS LOW LYING AND POOR DRAINAGE AREAS. .DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY THE ABOVE MENTIONED BROAD MID TO UPPER LEVEL TROUGHINESS WILL CONTINUE TO AFFECT THE LOCAL AREA AT LEAST THROUGH SATURDAY. THIS WILL AID IN THE FORMATION AND ENHANCEMENT OF AFTERNOON SHOWERS AND FEW THUNDERSTORMS MAINLY ACROSS WESTERN PUERTO RICO. THESE WEATHER CONDITIONS MAY LEAD TO MINOR FLOODING ACROSS AREAS OF POOR DRAINAGE...AS WELL AS LOCAL STREETS...HIGHWAYS...UNDERPASSES. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION MAY BE NEEDED. AMZ715-725-VIZ001-002-281000- ST. THOMAS ST. JOHN ADJACENT ISLANDS-ST CROIX- NEARSHORE ATLANTIC AND ADJACENT CARIBBEAN COASTAL WATERS- 556 AM AST FRI FEB 27 2009 THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE U.S. VIRGIN ISLANDS AND THE ADJACENT COASTAL WATERS. .DAY ONE...TODAY AND TONIGHT NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION WILL NOT BE NEEDED.
The national radar mosaic for the moment the first event began.
1 flood. Local standard time, as filed.
A person was trapped by flood waters on Genova street in the Caparra neighborhood of Guaynabo City.
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, February 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: 149249.