Heavy Snow in Alaska, March 11 to 13, 2009

Name: Heavy Snow in Alaska, March 11 to 13, 2009
Start: 2009-03-11T04:29
End: 2009-03-13T04:00
Location: Alaska

March 11 to 13, 2009 · NWS AJK · 7 events in 7 counties and zones

Before the event began, cold air was entrenched over the northern inner channels of Southeast Alaska panhandle. A strong low developed as it moved northeast over the Gulf of Alaska on 3/11.

The toll

Deaths: 0
Injuries: 0
Property damage: None recorded
Crop damage: None recorded
Events: 7

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 AJK wrote it up.

Before the event began, cold air was entrenched over the northern inner channels of Southeast Alaska panhandle. A strong low developed as it moved northeast over the Gulf of Alaska on 3/11. The associated weather front introduced warm moist air over the Panhandle creating an overrunning snow event on 3/12.

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 Juneau, AK wrote its last area forecast discussion before the first event at Mar 11, 3:58 AM AKST, 31 minutes earlier.

Area forecast discussion, Mar 11, 3:58 AM AKST, 31 minutes before

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
458 AM AKDT WED MAR 11 2009

.SHORT TERM...WEAK TROF OVER THE EASTERN GULF WILL GRADUALLY
DISSIPATE THERE BY LATE TONIGHT. A LOW WILL DEVELOP OVER THE NE
PAC AND MOVE NNE TO THE CENTRAL GULF BY LATE TONIGHT.

MAIN FORECAST CONCERN WILL BE WHEN PRECIP TRANSITION FROM SNOW TO
RAIN WILL OCCUR...IF IT DOES...AND HOW MUCH SNOW FALLS BEFORE THE
CHANGEOVER. DOES NOT LOOK LIKE MUCH OF A BREAK IN THE PRECIP
BETWEEN THE DYING TROF AND NEXT LOW COMING IN DUE TO DEEP LAYER
ONSHORE FLOW AND OVERRUNNING OF COLDER LOW LEVEL AIRMASS
ESPECIALLY OVER THE N. THERE WILL BE A PRECIP INTENSITY PEAK LATER
THIS MORNING AND AFTERNOON AS UPPER SHORTWAVE TROF MOVES THROUGH
THE AREA...THEN PRECIP RATES SHOULD DIMINISH LATER IN THE
AFTERNOON BEFORE INCREASING AGAIN TONIGHT AHEAD OF THE LOW.
CURRENTLY...ENTIRE AREA IS COLD ENOUGH FOR SNOW...BUT EXPECT THE
SRN COAST TO WARM UP ENOUGH TO GO TO A MIX BY MIDDAY THEN GO TO
ALL RAIN BY MID- AFTERNOON. THIS TRANSITION WILL MOVE N AND E TO
THE PAKT/PASI ZONES LATER THIS AFTERNOON...THE REACH THE
PAPG/PAGN/PAEL AREAS BY LATE EVENING. BECAUSE OF THE CHANGEOVER
EXPECTED FOR PAPG/PAEL/PAGN AREAS TONIGHT...CANCELLED THE WINTER
STORM WATCH.

FURTHER N...THE PAJN/PAOH/PAGS AREAS SHOULD REMAIN ALL SNOW
THROUGH TONIGHT EXCEPT SOME RAIN MAY MIX IN OVER THE SRN PAOH ZONE
LATER TONIGHT. EXPECT 3 TO 5 INCHES OF SNOW TONIGHT IN THOSE
AREAS...SO WENT WITH A WINTER WX ADVY FOR TONIGHT IN THOSE AREAS.
FINALLY...OVER THE FAR N...COLD AIR WILL HANG ON THE LONGEST AND
TRANSITION TO RAIN WILL WAIT UNTIL AFTER SHORT TERM PERIOD. LOOKS
LIKE A FAIRLY HEAVY SNOW EVENT FOR PAHN AREA WITH FAVORABLE
UPSLOPE SE FLOW AT 850 MB LEVEL OVERRUNNING A NW LOW LEVEL
FLOW...SO WENT AHEAD AND ISSUED A WINTER STORM WARNING FOR THEM
BEGINNING AT MIDNIGHT TONIGHT. EXPECT 4 TO 8 INCHES OF SNOW THERE
BY DAYBREAK THU. THE PAGY AREA WILL SEE SNOW INCREASE LATE
TONIGHT...AND AFTER COORD WITH LONG TERM ENDED UP ISSUING A WINTER
WEATHER ADVY STARTING AT MIDNIGHT TONIGHT. THE PAYA AREA WILL
REMAIN A BORDERLINE CASE AS FAR AS PTYPE TONIGHT...BUT THE QPF
THERE IS EXPECTED TO BE SOMEWHAT LIGHTER THAN AREAS FURTHER E SO
NO ADVYS OR WARNINGS ISSUED FOR THEM.

OTHERWISE...WILL SEE SCA LEVEL WINDS ALONG THE OUTER WATERS
THROUGH TONIGHT WITH POTENTIAL FOR GALES OVER THE NE GULF LATER
TONIGHT. THE E-W CHANNELS WILL SEE WINDS PICK UP TONIGHT TO MAX
SCA OR MIN GALE LEVELS...WHILE THE MORE N-S CHANNELS PEAK AT MIN
SCA LEVELS AT MOST. TEMPERATURES WILL BE STEADY TO SLOWLY RISING
OVER THE S AND CENTRAL AREAS TONIGHT AS WARMER MARITIME AIR MOVES
IN FROM THE S...WITH A MINIMAL DROP IN TEMPS EXPECTED OVER THE N
TONIGHT.

&&

.LONG TERM...MODEL RUNS FROM 00Z AND 06Z WERE IN FAIRLY GOOD
AGREEMENT INTO THE WEEKEND WITH SOME MINOR DIFFERENCES BUT THEY
ARE CONTINUING TO BE FAIRLY SOLID ON THE MAIN TREND. BIGGEST
PROBLEM THIS MORNING WAS THE SYSTEM MOVING OVER THE EASTERN GULF
AND SOUTHEAST PANHANDLE THROUGH EARLY THURSDAY WITH PRECIPITATION
TYPE. SHOULD BE SEEING A GOOD WARM UP WITH IT SO HAVE MOVED A
GOOD PORTION OF THE PRECIPITATION OVER TO RAIN WITH ONLY NORTHERN
PANHANDLE GETTING ANY GOOD AMOUNTS.

ONCE THE UPPER TROUGH MOVES THROUGH BY THURSDAY EVENING A COLD
POOL MOVES BACK INTO THE AREA FROM THE WEST. AT THE SURFACE A
GENERAL AREA OF LOW PRESSURE WILL PERSIST OVER THE GULF OF
ALASKA... AS ANOTHER UPPER SHORT WAVE MOVES INTO THE GULF BY THE
END OF THE WEEK SETUP A GENERAL UPPER LEVEL TROUGH/CUT OFF LOW
OVER THE GULF THAT WILL KEEP THE MAIN UPPER FLOW PATTERN AWAY FROM
SOUTHEAST ALASKA. WEAK TROUGHS/FRONTS EXPECTED TO ROTATE INTO
SOUTHERN HALF OF THE PANHANDLE ...DISSIPATING AS THEY REACH THE
NORTHERN PANHANDLE...INTO NEXT WEEK.

USED THE ECMWF/GFS TO MAKE SOME MINOR ADJUSTMENTS IN THE MIDWEEK
PORTION OF THE PACKAGE...WHILE USING MORE OF HPC GUIDANCE AT THE
END OF THE FORECAST PACKAGE AND TO ADD DAY 8. OVER ALL CONFIDENCE
REMAINS ABOVE AVERAGE INTO EXTENDED RANGE DUE TO BLOCKING PATTERN
THAT SHOULD DEVELOP OVER THE GULF.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO 6 AM AKDT
     THURSDAY FOR AKZ020-021-025.
         WINTER STORM WARNING FROM MIDNIGHT TONIGHT TO 12 PM AKDT
     THURSDAY FOR AKZ019.
         WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO 12 PM AKDT
     THURSDAY FOR AKZ018.
MARINE...GALE WARNING FOR PKZ021-022-033.
         SMALL CRAFT ADVISORY FOR PKZ031-034>036-041>043-051-052.

&&

RWT/BEZENEK

Event by event

7 heavy snow. Local standard time, as filed.

Heavy Snow, Haines Borough and Lynn Canal

When: March 11, 4:29 AM AKST to March 13, 4:00 AM AKST
Where: Haines Borough and Lynn Canal forecast zone
Reported by: COOP Observer

A spotter near Haines reported 10.5 inches of snow since the morning hours and at total of 13.2 inches so far for the event at 4 pm. By 8 pm that night they had received a storm total of 17.1 inches. Haines customs station reported an event total of 13 inches on the morning of the 13th, and the Haines Coop had a 24 hour total of 14 inches. Most of the heavy snow fell during the daytime on the 12th according to an observation site in Haines.

Heavy Snow, Inner Channels From Kupreanof Island to Etolin Island

When: March 11, 11:00 PM AKST to March 12, 2:00 PM AKST
Where: Inner Channels From Kupreanof Island to Etolin Island forecast zone
Reported by: COOP Observer

A spotter in Petersburg reported 9.5 inches of snow from 6 am to 2 pm on the 12th. The coop in Petersburg reported a 24 hr snow total of 12.0 inches at 9 pm on the 12th.

Heavy Snow, Glacier Bay

When: March 12, 2:00 AM AKST to 2:00 PM AKST
Where: Glacier Bay forecast zone
Reported by: COOP Observer

Two coop sites in the Gustavus area reported 8 inches of snow at 7 am and 9 inches at 8 am on 3/12. Based on observations the heavier snow started falling after midnight on the 2nd and snow continued into the afternoon hours in the area although little additional accumulation resulted.

Heavy Snow, Eastern Chichagof Island

When: March 12, 2:00 AM AKST to 12:00 PM AKST
Where: Eastern Chichagof Island forecast zone
Reported by: COOP Observer

The coop observer in Hoonah reported at snow total at 9 am March 12 of 9.6 inches, and based on estimates from nearby observations sites the heavier snow began after midnight the 12th so the accumulation was in less than 12 hours. An additional couple of inches were reported during the day on the 12th.

Heavy Snow, Eastern Baranof Island and Southern Admiralty Island

When: March 12, 2:00 AM AKST to 12:00 PM AKST
Where: Eastern Baranof Island and Southern Admiralty Island forecast zone
Reported by: COOP Observer

The coop in Hidden Falls reported a new snow fall total of 11.5 inches as of 5 pm on the 12th. Nearby observations indicated that the most of the snow fell after midnight on the 12th.

Heavy Snow, Juneau Borough and Northern Admiralty Island

When: March 12, 2:00 AM AKST to 12:00 PM AKST
Where: Juneau Borough and Northern Admiralty Island forecast zone
Reported by: COOP Observer

Several coops in the Juneau area...primary over interior valleys reported more than 10 inches of snow from the event. Annex Creek had received 15.6 inches snow by 6 pm on the 12th. Snettisham Power Plant received 11.0 inches by 7 am on the 13th and Canyon Island has 12.0 inches by 8 am on the 13th. The heaviest band of snow in the Juneau area moved through between 2 am and 5 pm on the 12th based on observations from sites around Juneau.

Heavy Snow, Salisbury Sound to Cape Fairweather Coastal Area

When: March 12, 3:00 AM AKST to 12:00 PM AKST
Where: Salisbury Sound to Cape Fairweather Coastal Area forecast zone
Reported by: COOP Observer

The coop observer in Elfin Cove reported at snow total at 3 pm on the 12th of March of 11.9 inches. Observations around Elfin Cove had the snow beginning after midnight on the 12th and observations at Elfin Cove showed the snow tapered off after noon that day.

What these are

Heavy Snow: Snowfall reaching the local warning threshold without the other hazards of a winter storm.

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

The same day elsewhere

Every storm in Alaska in 2009 Every state in 2009 This day in weather history Warnings in Alaska, March 2009

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: 159059, 159077, 159068, 159069, 159074, 159076, 159070.