Heavy Rain and Winter Weather in Hawaii, November 1 to 4, 2011

Name: Heavy Rain and Winter Weather in Hawaii, November 1 to 4, 2011
Start: 2011-11-01T10:39
End: 2011-11-04T15:36
Location: Hawaii

November 1 to 4, 2011 · NWS HFO · 12 events in 4 counties and zones

Upper air instability generated heavy rain over much of the Aloha State, with isolated thunderstorms and snow at the higher elevations of Mauna Kea and Mauna Loa on the Big Island of Hawaii. There were no reports of significant property damage or injuries.

Where it happened

Every event with a place to put it; 1 filed by county or forecast zone are drawn at its center, in a lighter ring. 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

Open the live radar over this ground

The toll

Deaths: 0
Injuries: 0
Property damage: None recorded
Crop damage: None recorded
Events: 12

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.

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 Nov 1, 10:13 AM HST, 26 minutes earlier.

Area forecast discussion, Nov 1, 10:13 AM HST, 26 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
1013 AM HST TUE NOV 1 2011

.SYNOPSIS...
BOUTS OF UNSETTLED WEATHER ARE IN STORE THIS WEEK. AN UPPER LEVEL
DISTURBANCE OVER THE STATE WILL POSE A THREAT FOR HEAVY
SHOWERS...WITH THUNDERSTORMS POSSIBLE OVER THE BIG ISLAND AND MAUI
TODAY. WITH GENTLE TO MODERATE TRADE WINDS BLOWING...SHOWERS WILL
FAVOR WINDWARD AND MAUKA AREAS...THOUGH LEEWARD AREAS WILL SEE
THEIR FAIR SHARE OF SHOWERS AS WELL. STRENGTHENING TRADE WINDS TONIGHT
AND WEDNESDAY WILL CARRY A MOIST AIR MASS OVER THE ISLANDS...
BRINGING IN WET TRADE WIND WEATHER THROUGH THE WEEKEND...WHILE
UNSTABLE CONDITIONS MAY LEAD TO PERIODS OF LOCALLY HEAVY SHOWERS.

&&

.DISCUSSION...
LOCALLY HEAVY RAINFALL REMAINS A THREAT TODAY FOR THE STATE WITH
THUNDERSTORMS POSSIBLE OVER MAUI AND THE BIG ISLAND. A FLASH FLOOD
WATCH WILL CONTINUE THROUGH TODAY OVER THE BIG ISLAND WITH THE
MOST ATMOSPHERIC INSTABILITY OVER THE ORCHID ISLE. CURRENT
RADAR...AS OF 9AM...SHOWS THUNDERSTORMS OVER NE AND SE COASTAL
WATERS OF THE BIG ISLAND...AND PASSING HEAVY SHOWERS OVER MOLOKAI
OAHU AND KAUAI...AND THE ASSOCIATED WINDWARD WATERS.

THERE ARE TWO MAIN CULPRITS FOR THE INCREASED RAINFALL AND
THUNDERSTORMS. THE FIRST...IS AN UPPER LEVEL LOW THAT HAS
BROUGHT COLD TEMPERATURES ALOFT OVER THE STATE. THE COLD AIR HAS
DESTABILIZED THE ATMOSPHERE...REMOVING OUR NORMAL TRADE WIND
INVERSION THAT CAPS CLOUD GROWTH. THE SECOND IS ENHANCED MOISTURE
MOVING ALONG WITH THE TRADE WINDS INCREASING THE CHANCE OF LOCALLY
HEAVY RAINFALL. OVERNIGHT SOUNDINGS SHOWED AN AVERAGE PRECIPITABLE
WATER /PW/ OF 1.7 INCHES AND SATELLITE PW ESTIMATES AGREE SHOWING
ABOVE NORMAL MOISTURE UPSTREAM OF THE ISLANDS.

WET CONDITIONS ARE EXPECTED TODAY AND INTO THE WEEKEND AS THE
UPSTREAM MOISTURE CONTINUES TO RIDE IN ON STRENGTHENING TRADE
WINDS. TRADES WILL GRADUALLY STRENGTHEN AS A STRONG SURFACE HIGH
PRESSURE SETS UP FAR NORTH OF THE ISLANDS. THE STRONGER TRADES
WILL FOCUS CLOUDS AND SHOWERS OVER WINDWARD AND MAUKA
AREAS...WHILE SHOWERS WILL PERIODICALLY BE BLOWN OVER LEEWARD
SECTIONS OF THE SMALLER ISLANDS. THE ATMOSPHERE WILL BE SOMEWHAT
UNSTABLE AS THE UPPER LOW CONTINUES TO HOVER OVER THE STATE...WITH
LOCALLY HEAVY SHOWERS REMAINING A POSSIBILITY.

&&

.AVIATION...
A MOIST AND UNSTABLE AIRMASS ASSOCIATED WITH THE UPPER LOW TRACKING
SLOWLY WEST ACROSS THE STATE TODAY...WILL CONTINUE TO BRING SHOWERY
AND CLOUDY WEATHER TO ESPECIALLY WINDWARD LOCATIONS. MVFR CIGS WILL
BE RULE THERE WITH ISOLATED IFR VIS IN HEAVIER SHOWERS. TEMPO MT
OBSC IN THE LARGER ROVING BANDS OF SHOWERS WILL CONTINUE TO BE AN
ISSUE TODAY. IN ADDITION...THE THREAT FOR ISOLATED THUNDERSTORMS
REMAINS OVER THE AREA...WITH THE ASSOCIATED RIME ICING ABOVE IN THE
12000 TO 17000 FOOT LAYER. AIRMET ZULU IN EFFECT FOR WINDWARD WATERS
FROM MOLOKAI SOUTHEAST TO THE BIG ISLAND...MAY NEED TO BE EXTENDED
AND OR EXPANDED AFTER 2200Z.

LIGHT TRADES ACROSS THE ISLANDS WILL ALLOW LOCAL SEA BREEZES TO
DEVELOP OVER SHELTERED LEEWARD LOCATIONS THIS AFTERNOON. THIS WILL
INITIATE ADDITIONAL SHOWERS AND A CHANCE OF THUNDERSTORMS IN THESE
LOCATIONS. WINDS AT PHNL AND PHJR WILL BE A HYBRID OF LIGHT
EASTERLY TRADES AND SEA BREEZE...RESULTING IN SOUTHEASTERLY WINDS
OCCASIONALLY INTERRUPTED BY LIGHT AND VARIABLE WINDS THROUGH THE
AFTERNOON.

&&

.MARINE...
THE CURRENT MODERATE NORTHWEST SWELL IS PEAKING AND WILL DIMINISH
TODAY AND WEDNESDAY. FORERUNNERS FROM ANOTHER MODERATE NORTHWEST
SWELL WILL ARRIVE LATE FRIDAY AND FILL IN THROUGH THE DAY ON
SATURDAY. A ROUGH...SHORT-PERIOD EASTERLY TRADE SWELL WILL BUILD BY
MID-WEEK AS THE TRADE WINDS INCREASE.

WINDS SHOULD REMAIN BELOW THE 25 KT SMALL CRAFT ADVISORY THRESHOLD
TODAY. AS TRADES INCREASE LATER TONIGHT AND WEDNESDAY...SMALL CRAFT
WINDS ARE EXPECTED FOR THE TYPICALLY WINDY WATERS AROUND THE BIG
ISLAND AND MAUI. ALSO...AS THE TRADE SWELL BUILD BY MID-WEEK...SEAS
MAY ALSO APPROACH THE 10 FT THRESHOLD FOR SMALL CRAFT ADVISORY.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH UNTIL 6 PM HST THIS EVENING FOR KONA-SOUTH BIG
ISLAND-BIG ISLAND NORTH AND EAST-KOHALA-BIG ISLAND INTERIOR.

&&

DISCUSSION...MORRISON
AVIATION...BRENCHLEY

The radar

The national radar mosaic for the moment the first event began.

Open the radar archive at this moment

Event by event

11 heavy rain, 1 winter weather. Local standard time, as filed.

Heavy Rain, Honolulu

When: November 1, 10:39 AM HST to 11:55 AM HST
Where: Honolulu County, 0.96 mi ESE of Honolulu to 0.65 mi E of Barbers Pt Housing
Reported by: Official NWS Observations
Coordinates: 21.316, -157.856

Winter Weather, Big Island Summit

When: November 1, 2:01 PM HST to November 4, 3:36 PM HST
Where: Big Island Summit forecast zone
Reported by: Park/Forest Service
Coordinates: 19.602, -155.523 (the zone’s center; the record gives no point)

The upper level system dropped 3 to 5 inches of snow on the summits of Mauna Kea and Mauna Loa on the Big Island of Hawaii.

Heavy Rain, Hawaii

When: November 2, 3:27 PM HST to 5:05 PM HST
Where: Hawaii County, 2.85 mi SW of Hilo to 3.88 mi NW of Glenwood
Reported by: Official NWS Observations
Coordinates: 19.705, -155.105

Heavy Rain, Maui

When: November 2, 4:04 PM HST to 6:43 PM HST
Where: Maui County, 0.74 mi ESE of Nahiku to 2.22 mi W of Keokea
Reported by: Official NWS Observations
Coordinates: 20.826, -156.090

Nine hikers were stranded as streams became swollen near the Twin Falls area of windward east Maui. However, all the hikers were rescued in good condition.

Heavy Rain, Hawaii

When: November 2, 6:38 PM HST to 9:13 PM HST
Where: Hawaii County, 1.58 mi ENE of Akaka Falls St Park to 2.22 mi SSW of Hawaiian Beaches
Reported by: Official NWS Observations
Coordinates: 19.857, -155.127

Heavy Rain, Maui

When: November 3, 1:16 PM HST to 2:28 PM HST
Where: Maui County, 1.08 mi SSW of Waianapanapa Sp to 0.42 mi WNW of Makawao
Reported by: Official NWS Observations
Coordinates: 20.767, -156.009

Heavy Rain, Hawaii

When: November 3, 1:57 PM HST to 4:59 PM HST
Where: Hawaii County, 1.29 mi SSE of Hakalau to 1.83 mi ESE of Mountain View
Reported by: Official NWS Observations
Coordinates: 19.882, -155.126

Heavy Rain, Hawaii

When: November 3, 5:23 PM HST to 6:53 PM HST
Where: Hawaii County, 1.36 mi NNW of Papaikou to 2.24 mi NW of Hawaiian Beaches
Reported by: Official NWS Observations
Coordinates: 19.799, -155.105

Heavy Rain, Honolulu

When: November 3, 10:17 PM HST to November 4, 12:36 AM HST
Where: Honolulu County, 2.18 mi WNW of Kahuku to 0.95 mi SE of Kaneohe
Reported by: Official NWS Observations
Coordinates: 21.693, -157.981

Heavy Rain, Hawaii

When: November 4, 3:11 AM HST to 6:13 AM HST
Where: Hawaii County, 0.9 mi S of Hakalau to 8.51 mi W of Kalapana
Reported by: Official NWS Observations
Coordinates: 19.887, -155.131

Heavy Rain, Maui

When: November 4, 3:38 AM HST to 7:07 AM HST
Where: Maui County, 1.9 mi S of Honokohau to 1.22 mi SW of Koali
Reported by: Official NWS Observations
Coordinates: 20.992, -156.621

Heavy Rain, Maui

When: November 4, 7:14 AM HST to 9:09 AM HST
Where: Maui County, 0.55 mi NW of Puukolii to 0.41 mi SE of Waiehu
Reported by: Official NWS Observations
Coordinates: 20.935, -156.687

What these are

Heavy Rain: Rainfall totals unusual for the place and season that did not produce a flood.
Winter Weather: Snow, sleet or freezing rain below warning levels that still caused disruption, damage or casualties.

After NWS Directive 10-1605, the rules offices file Storm Data by.

The same day elsewhere

Every storm in Hawaii in 2011 Every state in 2011 This day in weather history Warnings in Hawaii, November 2011

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: 351639, 351640, 351641, 351642, 351643, 351644, 351645, 351646, 351647, 351648, 351649, 351650.