21 with warm moist air aloft moving over cooler air near the surface for the Northern Lynn Canal area. 22 this storm extended into the Central Gulf of Alaska with very strong surface pressure gradients for very strong winds over the entire Panhandle while continuing to cause heavy snow.
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.
The episode as NWS AJK wrote it up.
A hurricane force low began to develop in the North Pacific on the afternoon of 12.21 with warm moist air aloft moving over cooler air near the surface for the Northern Lynn Canal area. By the early morning of 12.22 this storm extended into the Central Gulf of Alaska with very strong surface pressure gradients for very strong winds over the entire Panhandle while continuing to cause heavy snow. This system rapidly weakened on the late afternoon and evening of 12.22.
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 Juneau, AK wrote its last area forecast discussion before the first event at Dec 20, 3:45 PM AKST, 14 hours 55 minutes earlier.
SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
345 PM AKST TUE DEC 20 2011
.SHORT TERM...A RIDGE AT SURFACE AND ALOFT...WILL BUILD OVER
SOUTHEAST ALASKA THIS AFTERNOON AND EVENING AND THEN CONTINUE ESE
INTO B.C. BY WEDNESDAY MORNING. A 978 MB LOW IN BRISTOL BAY WILL
SEND A MODERATE OCCLUDED FRONT INTO THE EASTERN GULF TONIGHT AND
THEN WEAKEN IT OVER SOUTHEAST ALASKA WEDNESDAY.
WESTERLY WINDS CURRENTLY DIMINISHING ACROSS SOUTHEAST ALASKA THIS
AFTERNOON. BOTH CSP AND CDE HAVE FALLEN TO A MIN SMCR AND EXPECTED
TO GO BELOW SMCR THIS EVENING. AS RIDGE MOVES ACROSS SOUTHEAST
ALASKA TONIGHT WILL START TO SEE A SLY GRADIENT BUILD IN LYNN
CANAL THAT REACHES A GALE AND STRONG WIND FOR PAGY WEDNESDAY
AFTERNOON. AN EASTERLY COMPONENT WILL DEVELOP IN E-W CHANNELS BY
MORNING. SE WIND INCREASE THROUGH THE INNER CHANNELS WEDNESDAY
GOING TO SMCR BY AFTERNOON.
ISOLATED RAIN SHOWERS...A FEW MIXED WITH SNOW OR PELLETS THIS
AFTERNOON AND CONTINUE INTO THE EVENING. ATMO STABILIZES UNDER
RIDGE LATER TONIGHT. CAA FROM THE WEST CONTINUES TONIGHT AND
EXPECT ISOLD RA SHWRS TO BECOME ISOLD SNOW SHWRS BY MORNING.
LEADING EDGE OF WARM SECTOR SPREADS OVER PAYA WED MORNING AND TO
PAJN ARE BY LATE AFTERNOON. EXPECT THIS TO START AS ALL SNOW FOR
NORTHERN THIRD OF SE AK BUT WILL GO TO RAIN ALONG THE IMMEDIATE
COAST BY AFTERNOON. WILL KEEP SOUTHERN ZONES DRY ON WED BUT WILL
KEEP CLOUDS AND PATCHY FOG IN COOL, STABLE, AND MOIST BOUNDARY
LAYER. TEMPS FALLING TO OR SLIGHTLY BELOW FREEZING TONIGHT TO MID
TEENS ALONG THE HAINES HIGHWAY. HIGH TEMPS ON WED PROBABLY A
DEGREE OR 2 LOWER THAN TODAY WITH MANY LOCALS BARELY GOING ABOVE
FREEZING IN AFTERNOON.
MODELS WERE IN CLOSE AGREEMENT FOR THE SHORT TERM PERIOD AND USED
GFS NAM BLEND FOR PRES AND WIND.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/...AN ACTIVE WEATHER
PATTERN WILL PERSIST THROUGH THE EXTENDED PERIOD WITH AN OVERALL
SOUTHERLY FLOW KEEPING A MIX OF RAIN AND SNOW IN THE FORECAST. A GALE
TO STORM FORCE LOW WILL MOVE INTO THE GULF WED NIGHT AND THURS.
THIS WILL BRING GUSTY WINDS TO THE SOUTHERN AND COASTAL AREAS
ALONG WITH RAIN BECOMING HEAVY AT TIMES THROUGH THURS NIGHT.
NORTHERN AREAS WILL LIKELY SEE SNOW MIXED IN WITH THE RAIN THURS
MORNING...HOWEVER STRONG SOUTHERLY WARM AIR ADVECTION WILL KEEP ANY
ACCUMULATIONS TO A MINIMUM AND QUICKLY CHANGE TO ALL RAIN. THIS
SYSTEM WILL DEPART FRIDAY FOLLOWED QUICKLY BY ANOTHER LOW MOVING
INTO THE GULF. THERE MAY BE A FEW BREAKS IN THE CLOUD COVER
BETWEEN SYSTEMS...BUT HAVE KEPT MOSTLY CLOUDY SKIES IN THE
FORECAST. THE SECOND LOW WILL INCREASE WINDS OVER THE OUTSIDE WATERS
WITH SEAS BUILDING TO 20FT SATURDAY. BEHIND THIS SYSTEM 850MB
TEMPS DROP...ALLOWING FOR RAIN TO MIX WITH SNOW OVER THE SOUTH AND
CHANGE TO SNOW ACROSS THE NORTH FOR CHRISTMAS EVE INTO THE
HOLIDAY.
LONG RANGE MODELS HAVE ANOTHER LOW FOLLOWING A SIMILAR PATH FOR
THE START OF NEXT WEEK. HOWEVER...PLACEMENT OF EACH OF THESE LOWS
HAS VARIED FROM RUN TO RUN...WHICH GREATLY CHANGES WIND DIRECTIONS,
TEMPERATURES AND THE QUESTION OF RAIN VS SNOW...KEEPING FORECASTER
CONFIDENCE BELOW AVERAGE. LATEST RUNS HAVE SHIFTED THE THURSDAY
LOW SLIGHTLY MORE OFFSHORE THEN MOVING NORTH OF THE AREA...KEEPING
MUCH OF THE AREA UNDER THAT WARMER SOUTHERLY FLOW.
&&
.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...STRONG WIND FROM WEDNESDAY MORNING THROUGH WEDNESDAY AFTERNOON
FOR AKZ018.
STRONG WIND FROM LATE TONIGHT THROUGH WEDNESDAY MORNING FOR
AKZ017.
MARINE...GALE WARNING FOR PKZ012-041-051>053.
SMALL CRAFT ADVISORY FOR PKZ011-013-021-022-031>036-042-043.
&&
MM/HANNON3 high wind, 2 winter storm. Local standard time, as filed.
Haines Customs measured 6.5 inches of new snow at 0700 AKST 12.22. All of this snow fell overnight when comparing to the Haines Airport ASOS hourly observations. Town got rain, but the wind peaked at 35 KT at the Airport during the event.
Skagway Customs measured 7.0 inches new snowfall at 0700 AKST 12.22 all of which fell overnight as compared to PAGY ASOS hourly observations.
Although the sensors at Sitka and Port Alexander routinely had wind observations up to 50 MPH on 12.22, Cape Decision observed a peak wind of 54 KT around noon. Headlands and channels around Sitka were probably 60 MPH during the day.
Hydaburg AWOS had gusts as high as 66 KT around midday on 12.22. Most winds were 50 to 60 KT.
A trained spotter near Ketchikan observed many instances of 60 KT gusts on 12.22, especially during the morning. Annette ASOS had a peak wind of 51 KT late in the afternoon of 12.22.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Alaska in 2011Every state in 2011This day in weather historyWarnings in Alaska, December 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: 353415, 353407, 353397, 353398, 353399.