Heavy Rain, San Juan and Vicinity
- When
- May 23, 11:50 AM AST to 3:25 PM AST
- Where
- San Juan and Vicinity County, Catano
- Reported by
- Emergency Manager
- Coordinates
- 18.430, -66.120
Urban flooding was reported along road 5 at Cata o municipality.
Heavy Rain in Puerto Rico, May 23, 2008
Patches of low level moisture embedded in the trade wind flow combined with local effects to produce scattered to numerous afternoon showers over the eastern section of Puerto Rico including the San Juan Metro area. Periods of heavy rainfall were felt across the municipalities of Guaynabo and Bayamon.
Where it happened
Every event with a place to put it. Tap one for its entry below.
- Tornadoes
- Tropical storms and surge
- Floods
- Wind
- Hail
- Winter weather
- Heat and drought
- Cold
- Fire, smoke and dust
- Marine and coastal
- Other
The toll
- Deaths
- 0
- Injuries
- 0
- Property damage
- None recorded
- Crop damage
- None recorded
- Events
- 1
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.
What happened
The episode as NWS SJU wrote it up.
Patches of low level moisture embedded in the trade wind flow combined with local effects to produce scattered to numerous afternoon showers over the eastern section of Puerto Rico including the San Juan Metro area. Periods of heavy rainfall were felt across the municipalities of Guaynabo and Bayamon.
What forecasters said that day
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 May 23, 11:23 AM AST, 27 minutes earlier.
Area forecast discussion, May 23, 11:23 AM AST, 27 minutes before
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SAN JUAN PR 1123 AM AST FRI MAY 23 2008 .UPDATE...SCATTERED SHOWERS BEGAN TO DEVELOP ACROSS SAN JUAN AND VICINITY LATE THIS MORNING...AND THIS SHOWER ACTIVITY WILL CONTINUE TO PROPAGATE ACROSS THE ISLANDS LATER THIS AFTERNOON MAINLY ACROSS THE WESTERN HALF OF PUERTO RICO. MADE MINOR CHANGES TO THE TEMPERATURES THROUGH DAY 5. NO OTHER CHANGES WERE MADE. .AVIATION...EXPECT PREVAILING VFR CONDITIONS ACROSS THE LOCAL ISLANDS AND AT ALL LOCAL TAF SITES FOR THE REST OF TODAY. HOWEVER...MVFR OR POSSIBLY EVEN BRIEF IFR CONDITIONS...AND LOCAL MOUNTAIN OBSCURATIONS...WILL BE POSSIBLE THIS AFTERNOON FROM 17Z- 22Z...ESPECIALLY ACROSS TJBQ...TJMZ AND TJSJ. && .PREV DISCUSSION... /ISSUED 527 AM AST FRI MAY 23 2008/ SYNOPSIS... MID TO UPPER LEVEL HIGH PRESSURE RIDGE EXTENDED FROM THE WESTERN CARIBBEAN NORTHWARDS ACROSS THE GREATER ANTILLES THEN INTO THE CENTRAL ATLANTIC. THIS SEPARATES AN UPPER TROUGH ACROSS THE NORTHWEST ATLANTIC...AND ANOTHER ACROSS THE EAST ATLANTIC WHICH EXTENDS SOUTHWARDS ACROSS THE TROPICAL ATLANTIC. SURFACE HIGH PRESSURE RIDGE EXTENDED FROM THE CENTRAL ATLANTIC WEST SOUTHWEST THROUGH THE BAHAMAS...AND WILL GRADUALLY WEAKEN ACROSS THE AREA INTO THE WEEKEND. THE AREA OF HIGH PRESSURE CENTERED ACROSS THE CENTRAL ATLANTIC WILL SHIFT FURTHER EASTWARD...AS A COLD FRONTAL SYSTEM EXITS THE EASTERN UNITED STATES AND MOVES ACROSS THE WESTERN ATLANTIC SATURDAY THROUGH SUNDAY. IN THE MEANTIME...A WEAK LOW LEVEL DISTURBANCE IN THE PREVAILING EASTERLIES WILL CONTINUE WESTWARDS ACROSS THE EASTERN CARIBBEAN TODAY THROUGH SATURDAY MORNING. DISCUSSION... DOMINANT ATLANTIC HIGH PRESSURE WILL MAINTAIN A MODERATE TRADE WIND FLOW ACROSS THE REGION AT LEAST THROUGH SATURDAY...THEN GRADUALLY WEAKEN AS THE UPPER LEVEL TROUGH DEEPENS ACROSS THE WEST ATLANTIC...AND MOVES ACROSS HISPANIOLA ON SUNDAY...THEN APPROACHES THE LOCAL AREA BY MONDAY. THE RECEDING ATLANTIC HIGH AND THE APPROACHING UPPER LEVEL LONG WAVE TROUGH WILL INDUCE LOW LEVEL TROUGHINESS ACROSS THE LOCAL REGION...AND THEREFORE INCREASE THE CHANCES FOR EVEN MORE ACTIVE WEATHER ACROSS THE AREA BY EARLY NEXT WEEK. IN ADDITION... LATEST GFS MODEL GUIDANCE CONTINUE TO SUGGEST A TROPICAL WAVE TO AFFECT THE LOCAL AREA MONDAY THROUGH TUESDAY...FOLLOWED BY YET ANOTHER DURING THE LATTER PART OF THE NEXT WEEK. SO FOR THE WEEKEND...EXPECT PASSING CLOUDS AND TRADE WIND SHOWERS TO AFFECT THE EAST COASTAL AREAS DURING THE MORNING HOURS...FOLLOWED BY DIURNAL AND LOCAL TERRAIN INDUCED SHOWER ACTIVITY DURING THE AFTERNOON HOURS. BY EARLY NEXT WEEK MORE ACTIVE WEATHER IS EXPECTED DUE TO THE PROXIMITY OF THE UPPER LEVEL TROUGH AND THE APPROACHING TROPICAL WAVES. AS USUAL...WILL HOWEVER CONTINUE TO MONITOR AND MAKE NECESSARY ADJUSTMENTS TO THE FORECAST PACKAGE WITH TIME. AVIATION... EXPECT PREVAILING VFR CONDITIONS ACROSS THE LOCAL ISLANDS AND AT ALL LOCAL TAF SITES THIS MORNING. HOWEVER...MVFR OR POSSIBLY EVEN BRIEF IFR CONDITIONS...AND LOCAL MOUNTAIN OBSCURATIONS...WILL BE POSSIBLE THIS AFTERNOON FROM 17Z-22Z...ESPECIALLY ACROSS TJBQ...TJMZ AND TJSJ. PATCHY LOW LEVEL MOISTURE AND SHOWERS MAY AFFECT THE TIST AND TISX EARLY THIS AFTERNOON THROUGH THE EVENING HOURS FROM TIME TO TIME AS THESE CLOUDS AND SHOWERS MOVE ACROSS THE ISLANDS WITH THE HELP OF THE TRADE WINDS WHICH WILL BE AVERAGING FROM 10 TO 15 KNOTS. MARINE... FAIRLY TRANQUIL MARINE CONDITIONS ARE EXPECTED TO CONTINUE ACROSS THE REGIONAL WATERS THROUGH SATURDAY EXCEPT FOR SOME PERIODS OF LOCALLY HEAVY RAINFALL ASSOCIATED WITH ISOLATED TO SCATTERED SHOWER ACTIVITY. GENERALLY EXPECT WINDS OF 16 KNOTS OR LESS AND SEAS OF 4 FEET OR LESS. && .PRELIMINARY POINT TEMPS/POPS... SJU 86 75 87 75 / 20 10 30 20 STT 85 75 85 75 / 40 40 40 40 && .SJU WATCHES/WARNINGS/ADVISORIES... PR...NONE. VI...NONE. && 71/06
Hazardous weather outlook, May 23, 6:29 AM AST, 5 hours 21 minutes before
HAZARDOUS WEATHER OUTLOOK FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS NATIONAL WEATHER SERVICE SAN JUAN PR 629 AM AST FRI MAY 23 2008 AMZ710>750-PRZ001>013-241030- 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- 629 AM AST FRI MAY 23 2008 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PUERTO RICO AND THE ADJACENT COASTAL WATERS. .DAY ONE...TODAY AND TONIGHT .DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY SUNDAY INTO MONDAY AND EVEN FURTHER...AN UPPER LEVEL TROUGH IS FORECAST TO EXIT THE EASTERN SEABOARD OF THE UNITED STATES AND DIG SOUTHEASTWARD ACROSS THE SOUTH WESTERN ATLANTIC. FROM MONDAY AFTERNOON THROUGH AT LEAST MID WEEK...WE WILL BE UNDER THE INFLUENCE OF THIS UPPER LEVEL TROUGH WHICH WILL HELP TO DESTABILIZE THE ATMOSPHERE...CREATING FAVORABLE CONDITIONS ALOFT FOR ACTIVE WEATHER DAYS DURING THE UPCOMING WEEK. ALSO...A WEAK TROPICAL WAVE IS FORECAST TO MOVE ACROSS THE LOCAL AREA BY THE SECOND HALF OF THE UPCOMING WEEKEND...YET ANOTHER TROPICAL WAVE...EXPECTED TO ARRIVE THE LOCAL AREA BY THURSDAY. THIS CAN BE TRANSLATED TO POSSIBLE MODERATE TO HEAVY SHOWER ACTIVITY WITH THUNDERSTORMS OVER LAND AREAS AND ACROSS THE LOCAL COASTAL WATERS. WE WILL KEEP MONITORING THIS SCENARIO AS THE WEEKEND PROGRESSES AS WELL AS ADJUSTING THE WEATHER FORECAST ACCORDINGLY TO MAINTAIN THE PUBLIC INFORM AT ALL TIMES. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION WILL NOT BE NEEDED AT THIS TIME. AMZ720-730-VIZ001-002-241030- ST. THOMAS ST. JOHN ADJACENT ISLANDS-ST CROIX- NEARSHORE ATLANTIC AND ADJACENT CARIBBEAN COASTAL WATERS- 629 AM AST FRI MAY 23 2008 THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE U.S. VIRGIN ISLANDS AND THE ADJACENT COASTAL WATERS. .DAY ONE...TODAY AND TONIGHT .DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY SUNDAY INTO MONDAY AND EVEN FURTHER...AN UPPER LEVEL TROUGH IS FORECAST TO EXIT THE EASTERN SEABOARD OF THE UNITED STATES AND DIG SOUTHEASTWARD ACROSS THE SOUTH WESTERN ATLANTIC. FROM MONDAY AFTERNOON THROUGH AT LEAST MID WEEK...WE WILL BE UNDER THE INFLUENCE OF THIS UPPER LEVEL TROUGH WHICH WILL HELP TO DESTABILIZE THE ATMOSPHERE...CREATING FAVORABLE CONDITIONS ALOFT FOR ACTIVE WEATHER DAYS DURING THE UPCOMING WEEK. ALSO...A WEAK TROPICAL WAVE IS FORECAST TO MOVE ACROSS THE LOCAL AREA BY THE SECOND HALF OF THE UPCOMING WEEKEND...YET ANOTHER TROPICAL WAVE...EXPECTED TO ARRIVE THE LOCAL AREA BY THURSDAY. THIS CAN BE TRANSLATED TO POSSIBLE MODERATE TO HEAVY SHOWER ACTIVITY WITH THUNDERSTORMS OVER LAND AREAS AND ACROSS THE LOCAL COASTAL WATERS. WE WILL KEEP MONITORING THIS SCENARIO AS THE WEEKEND PROGRESSES AS WELL AS ADJUSTING THE WEATHER FORECAST ACCORDINGLY TO MAINTAIN THE PUBLIC INFORM AT ALL TIMES. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION WILL NOT BE NEEDED AT THIS TIME.
The radar
The national radar mosaic for the moment the first event began.
Event by event
1 heavy rain. Local standard time, as filed.
What these are
- Heavy Rain
- Rainfall totals unusual for the place and season that did not produce a flood.
After NWS Directive 10-1605, the rules offices file Storm Data by.
The same day elsewhere
- Tornadoes and Flash Flooding in Kansas, May 23, 2008
- Tornadoes and Hail in Oklahoma, May 23, 2008
- Hail and Damaging Winds in Kansas, May 23 to 24, 2008
- Tornadoes and Hail in Kansas, May 23, 2008
- Flash Flooding and Hail in Nebraska, May 23, 2008
- Tornadoes and Hail in Kansas, May 23 to 24, 2008
- Flash Flooding and Hail in Nebraska, May 23, 2008
- Flooding and Hail in Nebraska, May 23, 2008
- Flash Flood and Damaging Winds in Nebraska, May 23 to 24, 2008
- Tornadoes and Hail in Wyoming, May 23, 2008
- Tornadoes and Damaging Winds in Colorado, May 23, 2008
- High Wind in Alaska, May 23, 2008
More
Every storm in Puerto Rico in 2008Every state in 2008This day in weather historyWarnings in Puerto Rico, May 2008
Sources
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: 108736.