Heavy Rain, Hawaii
- When
- July 27, 3:42 PM HST to 7:01 PM HST
- Where
- Hawaii County, 3.84 mi SSE of Hawi to 5.01 mi NE of Waikoloa Village
- Reported by
- Official NWS Observations
- Coordinates
- 20.177, -155.811
Heavy Rain in Hawaii, July 27, 2015
With gentle winds and afternoon heating, heavy showers developed over the leeward mountain slopes on the Big Island of Hawaii, mainly in North and South Kohala. The rain caused small stream and drainage ditch flooding, and ponding on roadways.
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 HFO wrote it up.
With gentle winds and afternoon heating, heavy showers developed over the leeward mountain slopes on the Big Island of Hawaii, mainly in North and South Kohala. The rain caused small stream and drainage ditch flooding, and ponding on roadways. No serious property damage or injuries were reported.
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 Honolulu, HI wrote its last area forecast discussion before the first event at Jul 27, 10:00 AM HST, 5 hours 42 minutes earlier.
Area forecast discussion, Jul 27, 10:00 AM HST, 5 hours 42 minutes before
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE HONOLULU HI 1000 AM HST MON JUL 27 2015 .SYNOPSIS... EASTERLY TRADE WINDS WILL REMAIN IN THE GENTLE TO LOCALLY MODERATE RANGE THROUGH TOMORROW...WEAK ENOUGH TO ALLOW AFTERNOON SEA BREEZES TO SET UP ALONG MOST LEEWARD AREAS. SHOWERS WILL REMAIN FOCUSED ACROSS WINDWARD AREAS...WITH SPOTTY AFTERNOON SHOWERS DEVELOPING ACROSS LEEWARD AREAS. LOCALLY FRESH TRADE WINDS AND TYPICAL WINDWARD AND MAUKA SHOWERS PATTERN WILL RETURN ON WEDNESDAY. && .DISCUSSION... EAST TO EAST-SOUTHEAST TRADE WINDS WILL REMAIN AT GENTLE TO LOCALLY MODERATE STRENGTH THROUGH TUESDAY...WEAK ENOUGH FOR AFTERNOON SEA BREEZES TO PRODUCE CLOUDS AND SPOTTY SHOWERS OVER MOST LEEWARD AREAS. SURFACE HIGH PRESSURE WILL PERSIST ABOUT 1400 MILES NORTH OF THE STATE...WHICH WOULD NORMALLY BE STRONG ENOUGH TO DRIVE LOCALLY BREEZY TRADE WINDS LOCALLY. HOWEVER...A SERIES OF WEAK SURFACE TROUGHS PASSING NORTH OF THE ISLANDS HAS BEEN WEAKENING THE TRADE WINDS AND CAUSING THEM TO SHIFT OUT OF THE EAST TO EAST-SOUTHEAST. THE RESULT HAS BEEN AFTERNOON SEA BREEZES OVER MOST LEEWARD AREAS...PRODUCING CLOUDS AND SPOTTY SHOWERS. EXPECT A REPEAT THIS AFTERNOON...AND POSSIBLY AGAIN ON TUESDAY AFTERNOON. THE ATMOSPHERE IS SOMEWHAT STABLE...AS THE ISLANDS LIE WITHIN A TRANSITION ZONE BETWEEN MID TO UPPER LEVEL RIDGING TO THE SOUTH AND AND TROUGHING TO THE NORTH...BUT THE SOUNDINGS REVEAL PRECIPITABLE WATER VALUES RUNNING ABOUT 15 TO 20 PERCENT ABOVE NORMAL. AS A RESULT...WE CANNOT RULE OUT A BRIEF HEAVY SHOWER OVER LEEWARD AREAS THIS AFTERNOON. LEEWARD SHOWER ACTIVITY WILL RAPIDLY DIMINISH LATE IN THE AFTERNOON...ALLOWING RAINFALL TO BECOME FOCUSED OVER TYPICAL WINDWARD SLOPES OVERNIGHT. IN ADDITION...AN INCREASE IN HIGH CLOUDS IS POSSIBLE FOR THE WESTERN END OF THE STATE TONIGHT. TRADE WINDS WILL STRENGTHEN...AND A TYPICAL WINDWARD AND MAUKA RAINFALL WILL BECOME ESTABLISHED BY WEDNESDAY. THE SURFACE TROUGHS PASSING NORTH OF THE STATE WILL FINALLY MOVE OFF TO THE WEST... ALLOWING THE PRESSURE GRADIENT TO TIGHTEN AND TRADES TO STRENGTHEN OVER THE STATE. THE MID TO UPPER LEVEL RIDGE CURRENTLY TO THE SOUTH WILL STRENGTHEN AND SETTLE OVER THE ISLANDS...BRINGING INCREASINGLY STABLE CONDITIONS AND LIKELY LIMITING SHOWERS TO WINDWARD SLOPES. THE NEXT INCREASE IN MOISTURE COULD OCCUR NEXT WEEKEND...BUT UNCERTAINTY REMAINS HIGH AT THIS TIME. && .AVIATION... A HIGH PRESSURE RIDGE SITTING FAR TO THE NORTH WILL CONTINUE TO YIELD LIGHT TO MODERATE TRADE WINDS ACROSS THE STATE THROUGH TUESDAY. DAYTIME HEATING WILL ALLOW SEA BREEZES TO KICK IN AT TIMES DUE TO THE LIGHT WIND REGIME. BUT DO NOT EXPECT LAND BREEZES AT NIGHT TO BE AS SIGNIFICANT AS THE DAYTIME SEA BREEZES WITH LIGHT TRADES PREVAILING IN MOST AREAS AT NIGHT. THUS EXPECT SOME CLOUDS AND POSSIBLE SHOWERS TO BUILD PRIMARILY ACROSS THE INTERIOR AND LEEWARD SECTIONS WITH SOME MVFR CIGS OCCURING. OTHERWISE...VFR CONDITIONS ARE EXPECTED TO PREVAIL. NO AIRMETS ARE CURRENTLY IN EFFECT. && .MARINE... A HIGH SURF ADVISORY REMAINS POSTED FOR SOUTH FACING SHORES THROUGH TONIGHT. BUOYS 51002 AND 51003 SHOWED A MODEST PULSE OF RENEWED SWELL ENERGY IN THE 15 TO 16 SECOND RANGE DURING THE OVERNIGHT HOURS. THIS SHOULD MAINTAIN SURF AT CURRENT LEVELS...WELL ABOVE THE HIGH SURF ADVISORY THRESHOLD OF 8 FT...AND CONTINUE THE THREAT FOR SOME BREAKING WAVE AT HARBOR ENTRANCES THROUGH THE DAY. THE SWELL WILL BEGIN A GRADUAL DECLINE TONIGHT...AND ALTHOUGH THE ADVISORY IS CURRENTLY SET TO END BY TUESDAY MORNING...CONDITIONS SHOULD REMAIN BORDER LINE FOR TUESDAY. THE SWELL WILL SLOWLY SUBSIDE FOR SEVERAL DAYS...WITH NO OTHER SOURCES FOR SIGNIFICANT SWELL DUE THIS WEEK. WITH TRADE WINDS DUE TO BUILD ON WEDNESDAY...A SMALL CRAFT ADVISORY /SCA/ FOR THE TYPICALLY WINDY WATERS AROUND THE BIG ISLAND AND MAUI WILL LIKELY BE POSTED SOMETIME WEDNESDAY. ONCE UP...THE SCA SHOULD REMAIN IN PLACE THROUGH THE WEEKEND. && .HFO WATCHES/WARNINGS/ADVISORIES... HIGH SURF ADVISORY UNTIL 6 AM HST TUESDAY MORNING FOR SOUTH FACING SHORES OF ALL HAWAIIAN ISLANDS. && DISCUSSION/MARINE...WROE AVIATION...FUJII
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
- Excessive Heat in Missouri, July 27 to 29, 2015
- Hail and Damaging Winds in Montana, July 27, 2015
- Wildfire in California, July 27 to 31, 2015
- Flash Flooding and Damaging Winds in Iowa, July 27, 2015
- Hail and Damaging Winds in Virginia, July 27, 2015
- Flash Flood and Hail in Massachusetts, July 27, 2015
- Damaging Wind in Kentucky, July 27, 2015
- Damaging Winds in Montana, July 27, 2015
- Damaging Winds in North Dakota, July 27, 2015
- Excessive Heat in Kentucky, July 27 to 29, 2015
- Excessive Heat in Illinois, July 27 to 29, 2015
- Damaging Winds and Heavy Rain in Missouri, July 27, 2015
More
Every storm in Hawaii in 2015Every state in 2015This day in weather historyWarnings in Hawaii, July 2015
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: 586755.