A cold upper low over the eastern parts of the Aloha State generated heavy snow at the upper reaches of Haleakala in East Maui and the summits of Mauna Kea and Mauna Loa on the Big Island of Hawaii. There were no reports of serious injuries or property damage.
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The episode as NWS HFO wrote it up.
A cold upper low over the eastern parts of the Aloha State generated heavy snow at the upper reaches of Haleakala in East Maui and the summits of Mauna Kea and Mauna Loa on the Big Island of Hawaii. There were no reports of serious injuries or property damage.
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 Jan 19, 3:45 AM HST, 52 minutes earlier.
AREA FORECAST DISCUSSION...CORRECTED NATIONAL WEATHER SERVICE HONOLULU HI 345 AM HST WED JAN 19 2011 CLARIFIED WWA SECTION AND CORRECTED MINOR TYPOS .SYNOPSIS... AN UPPER LEVEL LOW WILL MOVE OVER THE ISLAND CHAIN TODAY...BRINGING CLOUDY SKIES...AREAS OF LIGHT RAIN...AND A THREAT OF THUNDERSTORMS. COLD TEMPERATURES ALOFT ASSOCIATED WITH THE LOW WILL BRING WINTER WEATHER TO THE SUMMITS OF HALEAKALA...MAUNA KEA AND MAUNA LOA... WHERE FREEZING RAIN AND SNOW WILL MAKE TRAVEL VERY DANGEROUS. TRADE WINDS...AND MORE SETTLED WEATHER...WILL RETURN THURSDAY...AND LAST INTO EARLY NEXT WEEK. A LARGE WEST NORTHWEST SWELL WILL BUILD TODAY...PEAK AT WARNING LEVELS THURSDAY...AND LAST INTO THE WEEKEND. && .DISCUSSION... A COMPLEX WEATHER PATTERN CURRENTLY EXISTS OVER THE ISLANDS AND ADJACENT WATERS...AND THE SHORT TERM FORECAST HAS MORE THAN THE NORMAL AMOUNT OF UNCERTAINTY. A WELL DEVELOPED MID AND UPPER LEVEL LOW...CENTERED JUST N OF THE BIG ISLAND AND JUST E OF MAUI...IS MOVING TOWARD THE SSW...WITH AN EXTENSIVE SHIELD OF MID AND HIGH LEVEL CLOUDS MOVING OVER THE ISLANDS IN THE N/NW FLOW ON THE W SIDE OF THE LOW. A COLD LIGHT RAIN EMANATING FROM THESE CLOUDS BEGAN REACHING THE GROUND IN MANY AREAS LATE LAST NIGHT...AND CONTINUES THIS MORNING...WITH -RA RECENTLY REPORTED ON OAHU...MOLOKAI AND LANAI. COLD TEMPERATURES NEAR THE CORE OF THE LOW...COMBINED WITH A SATURATED LAYER...ARE LIKELY BRINGING A WINTRY MIX OF PRECIPITATION TO THE VOLCANO SUMMITS OF MAUI AND THE BIG ISLAND...WHERE A WINTER STORM WARNING IS IN EFFECT. MOST LIKELY FORM OF PRECIP IN THE SHORT TERM IS EXPECTED TO BE FREEZING RAIN...FREEZING FOG OR RIME ICE... BUT SNOW IS CERTAINLY POSSIBLE LATER TODAY. THE LOW-LEVEL FLOW IS COMPLEX AS WELL...BUT MODELS HAVE BEEN CONSISTENT IN DEPICTING A MODERATE E TO SE FLOW NEAR KAUAI TODAY... AND N TO NE FLOW NEAR THE BIG ISLAND...DUE TO A SURFACE RIDGE N OF THE ISLANDS...A FRONT TO THE DISTANT NW OF KAUAI...AND A SHARPENING LOW-LEVEL TROUGH E OF THE BIG ISLAND. THE FORECAST CALLS FOR THE LOW ALOFT TO MOVE SSW AND GRADUALLY WEAKEN OVER THE NEXT COUPLE OF DAYS...BUT THE CORE OF THE LOW...AND ITS ASSOCIATED DESTABILIZING COLD POOL...IS EXPECTED TO PASS OVER MAUI COUNTY LATER THIS MORNING...BEFORE MOVING SSW OF THE ISLANDS BY TONIGHT. RADAR IS DETECTING AN INCREASING NUMBER OF SMALL BUT INTENSE ECHOES NEAR THE CORE OF THE LOW...WHICH ARE LIKELY THUNDERSTORMS...DESPITE THEIR RELATIVELY LOW TOPS. THE EXTENSIVE CLOUD DECK WILL CONTINUE TO BRING PERIODS OF LIGHT RAIN TO MANY AREAS TODAY...BUT HEAVY SHOWERS AND THUNDERSTORMS ARE ALSO EXPECTED. THESE THUNDERSTORMS ARE EXPECTED TO BE PROLIFIC LIGHTNING PRODUCERS...WITH SOME PRODUCING SMALL HAIL AND LOCALLY GUSTY WINDS. AS THE LOW DISTANCES ITSELF FROM THE ISLANDS TONIGHT AND THURSDAY... THE WINTER WEATHER THREAT WILL DIMINISH...AND ISLAND WEATHER WILL BECOME A LITTLE MORE SETTLED. THE BIG PICTURE SHOWS A SURFACE HIGH CENTERED FAR NE OF THE ISLANDS...BUT THE LOW ALOFT...AND A FRONT NW OF KAUAI...ARE INTERRUPTING THE TRADE FLOW OVER THE ISLANDS. OVER THE NEXT 24 TO 48 HOURS...THE FRONT WILL DISSIPATE NW OF KAUAI...AND THE SURFACE TROUGH E OF THE BIG ISLAND WILL GRADUALLY DISSIPATE AND MOVE E... ALLOWING TRADE WINDS TO GRADUALLY RETURN. UNTIL THEN WINDS WILL FAVOR AN E/SE DIRECTION NEAR KAUAI AND A NE DIRECTION NEAR THE BIG ISLAND...WITH VARIABLY GUSTY WINDS ALSO IN THE MIX DUE TO CONVECTIVE CELLS. WARMING TEMPERATURES AND BUILDING HEIGHTS ALOFT TONIGHT THROUGH FRIDAY WILL HAVE A STABILIZING EFFECT ON THE ATMOSPHERE...WITH THE ONLY FLY IN THE OINTMENT BEING A SURGE IN TRADE SHOWERS EXPECTED THURSDAY NIGHT AND FRIDAY AS TRADES BUILD IN FROM THE E. A SURFACE RIDGE EXTENDING SW FROM THE HIGH OFF THE CALIFORNIA COAST WILL BRING TRADE WINDS TO THE STATE INTO THE WEEKEND. MODERATE TRADE WINDS LOOK TO BE PRETTY DRY ON SATURDAY. THE W PACIFIC JET STREAM WILL SHIFT S EARLY NEXT WEEK...SENDING A WEAKENING FRONT TO NEAR KAUAI ON MONDAY...WHICH IS EXPECTED TO WEAKEN AND DISPLACE THE SUBTROPICAL RIDGE CLOSER TO THE ISLANDS...CAUSING A DECREASE IN THE TRADES ON SUNDAY AND MONDAY. RAINFALL LOOKS TO BE MINIMAL UNTIL THE WEAK FRONT BRINGS INCREASED WINDWARD SHOWERS TO KAUAI LATE MONDAY. && .AVIATION... THE LOW ALOFT IS RESPONSIBLE FOR DEEP-LAYER MODERATE TO SEVERE TURBULENCE NEAR THE ISLANDS...WITH THE ASSOCIATED MID AND HIGH LEVEL DECK ALSO RESULTING IN LIGHT RIME ICING. THESE HAZARDS TO AVIATION... IN ADDITION TO THOSE POSED BY THUNDERSTORMS...ARE EXPECTED TO CONTINUE THROUGH TODAY. && .MARINE... LATEST OBSERVATIONS FROM BUOY 51101 NW OF KAUAI SHOW INCREASING ENERGY IN THE 19...21 AND 24 SECOND PERIOD BANDS...WHICH MEANS THAT FORERUNNERS ASSOCIATED WITH A NEW...GIANT WNW SWELL ARE ARRIVING. THE SWELL WILL GET PROGRESSIVELY LARGER THROUGH THE DAY TODAY...AND A HIGH SURF WARNING GOES INTO EFFECT AT NOON TODAY FOR MOST AREAS... WITH THE KONA COAST RECENTLY ADDED TO THE WARNING. THE SOURCE LOW IS NEARLY STATIONARY...AND THE FETCH EXPANSIVE...SO SURF WILL REMAIN ELEVATED FOR SEVERAL DAYS. THE RESULTING SWELL WILL PRODUCE WARNING LEVEL SURF STARTING WEDNESDAY AFTERNOON ON KAUAI AND OAHU... SPREADING DOWN THE ISLAND CHAIN TONIGHT AND THURSDAY. THE SURF DISCUSSION /SRDHFO/ WAS UPDATED YESTERDAY...AND CONTAINS ADDITIONAL INSIGHT INTO THE SWELL...AS WELL AS PROVIDING SOME HISTORICAL CONTEXT. DUE TO THE BUILDING SWELL...COMBINED SEAS WILL INCREASE ABOVE THE THRESHOLD FOR THE ISSUANCE OF A SMALL CRAFT ADVISORY /SCA/...WHICH WAS ISSUED WITH THIS MORNING/S COASTAL WATERS FORECAST. A MARINE WEATHER STATEMENT WILL BE ISSUED SHORTLY...HIGHLIGHTING THE BUILDING WNW SWELL AND THE THREAT ASSOCIATED WITH THUNDERSTORMS TODAY. && .HFO WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH THROUGH THIS AFTERNOON FOR THE BIG ISLAND AND MAUI. WINTER STORM WARNING THROUGH THIS AFTERNOON FOR SUMMITS OF MAUI AND THE BIG ISLAND. HIGH SURF WARNING STARTING NOON TODAY FOR NORTH AND WEST FACING SHORES OF NIIHAU KAUAI OAHU AND MOLOKAI...AND FOR NORTH FACING SHORES OF MAUI. HIGH SURF WARNING STARTING 6 PM THIS EVENING FOR WEST FACING SHORES OF THE BIG ISLAND. SMALL CRAFT ADVISORY FOR WATERS AROUND KAUAI OAHU AND MAUI COUNTY STARTING 10 AM TODAY. SMALL CRAFT ADVISORY FOR REMAINING WATERS STARTING 10 PM TONIGHT. && BIRCHARD
The national radar mosaic for the moment the first event began.
2 winter storm. Local standard time, as filed.
Rangers reported heavy snow and 1-2 foot snow drifts.
Rangers reported heavy snow and accumulations exceeding 6 inches near the summit.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Hawaii in 2011Every state in 2011This day in weather historyWarnings in Hawaii, January 2011
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: 284720, 284721.