Heavy Rain, Hawaii
- When
- February 21, 4:59 PM HST to 6:59 PM HST
- Where
- Hawaii County, 4.87 mi SE of Kona Village Resort to 1.6 mi ESE of Kealakekua
- Reported by
- Official NWS Observations
- Coordinates
- 19.777, -155.930
Heavy Rain in Hawaii, February 21, 2017
An area of cold temperatures over the isles helped generate afternoon and early evening showers and thunderstorms over the leeward mountain slopes and coastal sections on the Big Island of Hawaii. The rain produced 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.
An area of cold temperatures over the isles helped generate afternoon and early evening showers and thunderstorms over the leeward mountain slopes and coastal sections on the Big Island of Hawaii. The rain produced small stream and drainage ditch flooding, and ponding on roadways. There were no reports of significant 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 Feb 21, 3:57 PM HST, 1 hour 2 minutes earlier.
Area forecast discussion, Feb 21, 3:57 PM HST, 1 hour 2 minutes before
Area Forecast Discussion National Weather Service Honolulu HI 357 PM HST Tue Feb 21 2017 .SYNOPSIS... Gusty trade winds will continue through the week as strong high pressure remains north of the state. Clouds and showers will favor windward and mauka areas, with brief showers passing over leeward locations. Winds will diminish over the weekend as an area of low pressure develops north of the islands. Showers may increase early next week, as tropical moisture moves in from the south. && .DISCUSSION... Strong high pressure north of the state is propelling gusty trade winds across the islands. Scattered showers moving along with the trades are affecting mainly windward areas with a some showers reaching leeward locations of the smaller islands. This weather pattern will continue through the week as transient high pressure areas traverse from west to east across the North Pacific. Daytime soundings from Lihue and Hilo show a moderately strength temperature inversion between 7 and 10 thousand feet which is capping most of the low level clouds. However, above the inversion, the soundings indicate cold temperatures aloft and a layer of midlevel instability. This instability is due to a passing upper level trough that has dropped 500 mb temperatures near -15 degrees Celsius. This layer of instability has been in place the last few days and has set off isolated afternoon thunderstorms over the highest slopes of the Big Island. So far this afternoon, one brief thunderstorm fired above the higher slopes of Mauna Loa while a few other convective showers continue to form over the higher slopes. Isolated thunderstorms are expected again Wednesday afternoon with a chance of brief snow showers at the summits of Mauna Loa and Mauna Kea. The upper trough will linger through Wednesday before exiting to the east Thursday. Global models are showing a change in the weather pattern over the weekend and next week. A near- gale low is expected to form along a passing cold front, and then linger north of the islands into next week. The current island forecast has trade winds weakening over the weekend and then winds turning from the east southeast early next week. The wind speed and direction are highly dependent on the low's location and strength so the forecast from Sunday into early next week will be highly fluid. If the global remain on track with this forecast, the low will also bring moisture from the tropics up and over the islands early next week. The light winds, abundant low level moisture, and instability aloft would bring the possibility of enhanced convective afternoon showers. && .AVIATION... High pressure northwest of the Hawaiian Islands will bring gusty northeasterly trade winds to the terminals through the TAF period. This will allow for mostly VFR conditions to prevail with brief MVFR trade wind showers. Showers will be focused across mainly windward and mountain areas, although a few showers are anticipated to make it into leeward areas. Northeasterly winds will gust to 20-30kts for the terminals into the early evening, decreasing slightly overnight, before returning again on Wednesday. Stronger winds with gusts to 45 kts can be expected across the channels, over higher terrain, and across mountain valleys. Aside from trade wind showers, mid-level instability will bring the possibility of isolated thunderstorms with snow showers for the Big Island summits through the afternoon and again on Wednesday afternoon. With gusty winds, AIRMET Tango for turbulence below 8,000 feet is anticipated to remain in effect over and immediately south through west of mountains through Wednesday. && .MARINE... A new strong high far northwest of the area is moving east. Winds will strengthen again tonight as the new high approaches. There will be widespread strong trade winds over the coastal waters with near gale force winds in the windiest areas around the Big Island and Maui. A Small Craft Advisory (SCA) is in effect for all Hawaiian coastal waters through Wednesday evening. The advisory will likely be extended for some areas. Winds will likely remain above the SCA threshold in the windy areas around the Big Island and Maui, while a couple of northwest swells may keep seas above the SCA threshold in areas exposed to the swells. The current north northwest swell will continue to subside through tonight. A new northwest swell arriving Wednesday may produce surf approaching advisory levels along north and west facing shores tonight and Wednesday. A northwest swell arriving Friday may be slightly larger and will likely continue through early next week. The strong trade winds will produce rough surf along east facing shores. && .HFO WATCHES/WARNINGS/ADVISORIES... Small Craft Advisory until 6 PM HST Wednesday for all Hawaiian waters- && Morrison...Discussion Woodrum...Aviation Donaldson...Marine
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
- Flood in Wyoming, February 21 to 22, 2017
- Flooding in Washington, February 21, 2017
- High Wind in Colorado, February 21, 2017
- Winter Storm and Damaging Wind in Utah, February 21 to 24, 2017
- Flood in Wisconsin, February 21 to 23, 2017
- Drought in Alabama, February 21 to 28, 2017
- Marine Thunderstorm Winds in Gulf of Mexico, February 21, 2017
- Flooding in Wisconsin, February 21 to 27, 2017
- Drought in Mississippi, February 21 to 28, 2017
- Flooding in South Dakota, February 21 to 28, 2017
- High Wind in Montana, February 21, 2017
- High Wind in Montana, February 21, 2017
More
Every storm in Hawaii in 2017Every state in 2017This day in weather historyWarnings in Hawaii, February 2017
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: 674278.