Heavy Rain, Hawaii
- When
- May 1, 12:23 PM HST to 3:19 PM HST
- Where
- Hawaii County, Akaka Falls St Park to 2.26 mi SSW of Hawaiian Beaches
- Reported by
- Official NWS Observations
- Coordinates
- 19.850, -155.150
Heavy Rain in Hawaii, May 1 to 2, 2014
Moisture from an old front and heating during daylight hours combined to produce heavy rain over the Big Island of Hawaii and Maui. During one rain event, a mudslide occurred along the Hana Highway in East Maui.
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
- 4
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.
Moisture from an old front and heating during daylight hours combined to produce heavy rain over the Big Island of Hawaii and Maui. During one rain event, a mudslide occurred along the Hana Highway in East Maui. Otherwise, the precipitation caused small stream and drainage ditch flooding, and ponding on roadways. There were no reports of serious property damage or injuries.
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 May 1, 9:42 AM HST, 2 hours 41 minutes earlier.
Area forecast discussion, May 1, 9:42 AM HST, 2 hours 41 minutes before
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE HONOLULU HI 942 AM HST THU MAY 1 2014 .SYNOPSIS... THE MODERATE TRADES WILL CONTINUE TO GRADUALLY DECREASE THROUGH THE END OF THE WEEK. SHOWERS WILL KEEP FAVORING WINDWARD AND MAUKA AREAS THROUGH FRIDAY...WITH SOME OF THE LARGER SHOWERS REACHING LEEWARD LOCATIONS AT TIMES ESPECIALLY DURING THE LATE NIGHT HOURS. LIGHTER WINDS WILL ALLOW FOR LOCAL LAND AND SEA BREEZES TO DEVELOP FRIDAY THROUGH THE UPCOMING WEEKEND...BRINGING AN INCREASE IN CLOUDS AND SHOWERS TO INTERIOR LOCATIONS DURING THE AFTERNOON AND EARLY EVENING HOURS. && .DISCUSSION... A REMNANT SHEAR LINE HAS PARKED ITSELF NORTHEAST TO SOUTHWEST ACROSS THE BIG ISLAND THIS MORNING. THE MORNING SOUNDING AT PHTO...ALTHOUGH IMPACTED BY RAINFALL...INDICATED AN ELEVATED INVERSION HEIGHT AND ENOUGH LOW LEVEL INSTABILITY TO SUPPORT ENHANCED SHOWERS. THIS HAS ALSO BEEN REFLECTED IN RADAR IMAGERY AND SURFACE OBSERVATIONS. OVERNIGHT RAINFALL AMOUNTS WERE BETWEEN 2 TO 4 INCHES OVER MANY WINDWARD BIG ISLAND SITES. SATELLITE AND RADAR IMAGERY ARE IN AGREEMENT THAT THE BAND OF ENHANCED TRADE WIND SHOWERS WILL LIKELY LINGER OVER THAT AREA THROUGH THE DAY TODAY. ELSEWHERE...SHOWERS HAVE BEEN LIMITED TO MAUKA AREAS THIS MORNING...AND THE PHLI SOUNDING INDICATES A STRONG INVERSION IN PLACE AROUND 8000 FEET. THIS WILL LIMIT SHOWERS FOR MUCH OF THE DAY...WITH THE POSSIBILITY OF INTERIOR SHOWERS FOR WESTERN ISLANDS AS WINDS BEGIN TO VEER LATE IN THE DAY. THE MODERATE TRADE WINDS THAT HAVE IMPACTED THE AREA FOR THE PAST 48 HOURS WILL BEGIN TO SUBSIDE TODAY...ESPECIALLY FOR THE WESTERN ISLANDS. THIS WILL HAPPEN IN RESPONSE TO THE APPROACH OF A WEAKENING FRONTAL BOUNDARY SEVERAL HUNDRED MILES NORTHWEST OF KAUAI. THIS FEATURE IS EXPECTED TO MOVE FAR ENOUGH TO THE EAST TO WEAKEN TRADE WIND FLOW FOR THE ENTIRE STATE BY EARLY SATURDAY. THE WEAKENING OF THE TRADES WILL LEAD TO A MORE CONVECTIVE PATTERN...WITH INTERIOR SHOWERS AND SEA BREEZES...FRIDAY THROUGH AT LEAST SUNDAY. GLOBAL FORECAST MODELS ARE IN GENERAL AGREEMENT THAT TRADES WILL BECOME BETTER ESTABLISHED LATE MONDAY INTO TUESDAY. && .AVIATION... REMNANT MOISTURE FROM A SHEAR LINE MOVING IN WITH THE EASTERLY TRADES WILL BRING SHOWERS...REDUCED VISIBILITY AND MTN OBSC TO WINDWARD SIDES OF THE ISLANDS. AIRMET SIERRA FOR TEMPO MTN OBSC FROM OAHU TO BIG ISLAND IS IN EFFECT TODAY. ELSEWHERE VFR PREVAILS WITH SCATTERED CLOUDS. BREEZY TRADE WINDS ARE PRODUCING LEEWARD LOW LEVEL TURB S THRU W OF ALL MTN. AIRMET TANGO WILL REMAIN POSTED THROUGH TODAY. WINDS ARE EXPECTED TO TAPER OFF TONIGHT. && .MARINE... THE DOMINANT SWELL OVER THE NEXT 48 HOURS WILL BE EASTERLY SWELL GENERATED BY THE PERSISTENT TRADE WINDS OVER THE PAST SEVERAL DAYS. SURF WILL REMAIN ELEVATED...BUT BELOW ADVISORY LEVELS...FOR EAST FACING SHORES. A MODERATE NORTHWEST SWELL IS ANTICIPATED FOR SATURDAY NIGHT THROUGH THE DAY SUNDAY. AT THIS TIME ADVISORY LEVEL SURF IS NOT EXPECTED. && .HFO WATCHES/WARNINGS/ADVISORIES... NONE. && DISCUSSION/MARINE...CANTIN AVIATION...FOSTER
The radar
The national radar mosaic for the moment the first event began.
Event by event
4 heavy rain. Local standard time, as filed.
Heavy Rain, Maui
- When
- May 2, 12:04 PM HST to 5:25 PM HST
- Where
- Maui County, 0.75 mi S of Puukolii to 1.56 mi ESE of Honokohau
- Reported by
- Official NWS Observations
- Coordinates
- 20.919, -156.681
Heavy Rain, Maui
- When
- May 2, 3:15 PM HST to 5:55 PM HST
- Where
- Maui County, 1.29 mi ESE of Huelo to 1.81 mi SW of Wailua
- Reported by
- Broadcast Media
- Coordinates
- 20.892, -156.212
A debris flow occurred along the Hana Highway one mile west of Keanae at 5:40 PM. The road was closed in the area for several hours as crews worked to open one lane by midnight. The road was completely reopened at 4:30 AM the next day, May 3rd, after most of the earth and debris had been removed.
Heavy Rain, Maui
- When
- May 2, 9:34 PM HST to 11:19 PM HST
- Where
- Maui County, 1.03 mi N of Puukolii to 1.43 mi S of Kahakuloa
- Reported by
- Official NWS Observations
- Coordinates
- 20.945, -156.679
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
- Flooding in New Jersey, May 1 to 6, 2014
- Flooding in Pennsylvania, May 1 to 2, 2014
- Drought in Texas, May 1 to 31, 2014
- Drought in Oklahoma, May 1 to 31, 2014
- Flooding in Arkansas, May 1 to 27, 2014
- Drought in New Mexico, May 1 to 31, 2014
- Wildfire in Texas, May 1 to 9, 2014
- Drought in Nebraska, May 1 to 31, 2014
- Wildfire in California, May 1 to 6, 2014
- Drought in Kansas, May 1 to 31, 2014
- Drought in Texas, May 1 to 31, 2014
- Drought in Texas, May 1 to 31, 2014
More
Every storm in Hawaii in 2014Every state in 2014This day in weather historyWarnings in Hawaii, May 2014
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: 512609, 512610, 512612, 512611.