Alaska, 2016Heavy Snow in Alaska, February 20 to 21, 2016
February 20 to 21, 2016 · NWS AFC · 2 events in 2 counties and zones
A low moving into the Gulf of Alaska brought southeast flow to Turnagain Pass. Combined with cold temperatures from a previous dry spell, significant snowfall occurred for the Kenai Peninsula and Anchorage.
- Deaths
- 0
- Injuries
- 0
- Property damage
- None recorded
- Crop damage
- None recorded
- Events
- 2
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.
A low moving into the Gulf of Alaska brought southeast flow to Turnagain Pass. Combined with cold temperatures from a previous dry spell, significant snowfall occurred for the Kenai Peninsula and Anchorage.
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 Anchorage, AK wrote its last area forecast discussion before the first event at Feb 20, 5:15 AM AKST, 9 hours 46 minutes earlier.
Area forecast discussion, Feb 20, 5:15 AM AKST, 9 hours 46 minutes before
SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
515 AM AKST SAT FEB 20 2016
.ANALYSIS AND UPPER LEVELS...
AN UPPER LEVEL LOW CENTERED SOUTH OF THE ALASKA PENINSULA IS THE
GYRE AROUND WHICH ALL OF THE SMALLER DISTURBANCES AFFECTING THE
AREA ARE ROTATING ABOUT. TWO SURFACE LOW PRESSURE SYSTEMS ARE
ROTATING ABOUT EACH OTHER IN A PRETTY NEAT EXAMPLE OF THE
FUJIWARA EFFECT. THE SUBTROPICAL JET IS FLOWING AROUND THE WEST
AND SOUTH SIDES OF THIS UPPER LOW. ON THE EAST SIDE OF THE
LOW...THE FLOW IS SIGNIFICANTLY WEAKER...BUT AT AROUND 90 KTS...IT
IS NOT INSIGNIFICANT. THIS IS IMPORTANT AS IT WILL BE ONE OF THE
MANY FORCING MECHANISMS FOR THIS WEEKEND'S POTENTIAL WINTER EVENT
IN SOUTHCENTRAL. ANOTHER OF THE FORCING MECHANISMS IS SURFACE
FRONTOGENESIS ONGOING OVER THE PACIFIC EAST OF THE DUAL SURFACE
LOWS. MORE ON THE UPCOMING WEEKEND EVENT BELOW.
WEAK UPPER LEVEL FORCING IS CAUSING A FEW LINES OF SNOW SHOWERS TO
MOVE NORTHWESTWARD ACROSS THE KENAI PENINSULA THIS MORNING. THE
FORCING CAUSING THEM IS ELONGATING AND WEAKENING AS IT PUSHES
NORTHWARD. WEAK NORTH TO NORTHEAST FLOW ACROSS SOUTHCENTRAL
CONTINUES INTO THE LOW WELL SOUTH OF THE ALASKA PENINSULA. WITH
THE SHOWERS CAUSING LOCAL INCREASES IN THE PRESSURE
GRADIENT THE WINDS HAVE BEEN SOMEWHAT HIGHER ACROSS THE ANCHORAGE
BOWL. THAT COUPLED WITH THICKER CLOUD COVER HAS KEPT TEMPERATURES SEVERAL
DEGREES WARMER IN MOST AREAS THAN THIS TIME YESTERDAY.
OVER SOUTHWEST ALASKA...A FEW WEAK FEATURES ARE CAUSING LOCALLY
THICKER CLOUD COVER FROM DILLINGHAM WEST...BUT BOTH KING SALMON
AND BETHEL RADARS ARE FREE OF ANY ASSOCIATED PRECIPITATION. A FEW
LIGHT SHOWERS ARE TRYING TO GET OVER THE ALEUTIAN RANGE ON THE
ALASKA PENINSULA...BUT OTHERWISE SOUTHWEST ALASKA IS QUIET.
INCREASED WINDS DUE TO THE STRONGER PRESSURE GRADIENT ARE THE
BIGGEST CHANGE IN THE WEATHER OVER NEARLY ALL OF SOUTHWEST ALASKA.
FOR THE BERING/ALEUTIANS...THE ACERBIC TROUGH THAT BROUGHT SNOW TO
THE PRIBILOFS YESTERDAY AND BLIZZARD CONDITIONS TO NIKOLSKI HAS
CONTINUED MOVING WESTWARD AND WEAKENING. THE LOW SOUTH OF THE
ALASKA PENINSULA IS THE STRONGER OF THE SYNOPTIC FEATURES LEADING
TO THE TROUGH AS COMPARED WITH THE DYING LOW MOVING INTO THE
KAMCHATKA PENINSULA...AS SUCH THE EASTERLY FLOW HAS BEEN DOMINANT
LEADING TO THE WESTWARD MOVEMENT OF THE TROUGH. STRONG COLD
NORTHWEST FLOW CONTINUES WEST OF THE TROUGH OVER THE WESTERN
BERING AND WESTERN AND CENTRAL ALEUTIANS...BRINGING COLD SNOW
SHOWER ACTIVITY TO THOSE AREAS WITH COLD TEMPS IN THE 20S.
&&
.MODEL DISCUSSION...
SYNOPTICALLY GUIDANCE HEMISPHERIC AND MESOSCALE ALIKE HAVE A
SIMILAR HANDLE ON THE UPPER LEVEL PATTERN. THE MAIN DRIVERS OF THE
PATTERN ARE WELL AGREED UPON IN THE COMING DAYS...A COMPLEX LOW
SOUTH OF THE ALASKA PENINSULA AND WESTERN NORTH AMERICA RIDGING.
THE JET BETWEEN THE TWO IS WHERE ALL THE ACTION RESIDES. HOWEVER
AS ALWAYS...THE DEVIL IS IN THE DETAILS. THE UPPER LEVEL JET AND
LARGE SCALE DYNAMICS ARE WELL AGREED UPON AMONG MODELS. THE SETUP
BEGINS TODAY AS AN OCCLUDED FRONT ASSOCIATED WITH THE COMPLEX LOW
STALL OVER THE NORTHERN GULF OF ALASKA JUST AS THE 300 MB JET IS
PROGGED TO INCREASE AND SHIFT OVER SOUTHCENTRAL FROM THE SOUTHEAST
LATE TONIGHT AT 80-100 KTS. A BASAL TROUGH CURRENTLY IN THE NORTH
PACIFIC SHOWN TO RIDE THE AFOREMENTIONED FRONT DEVELOPING A
FRONTAL WAVE THAT REALLY ENERGIZES THE LOW LEVEL GRADIENT OVER THE
NORTHEAST/NORTHERN GULF. GUIDANCE IS EVEN IN REALLY GOOD AGREEMENT
WITH THE DEVELOPMENT OF THE LOW LEVEL JET...HOWEVER ONCE IT
APPROACHES THE CHUGACH IS WHEN DIFFERENCES BEGIN TO SHOW UP. THE
HIGHER RESOLUTION MODELS (NAM/CANADIAN REGIONAL) CARRY THIS FLOW A
LITTLE STRONGER OVER THE MOUNTAINS AND DOWNSLOPE ON THE LEE SIDE
WHERE AS THE COARSER RESOLUTION GFS/ECMWF STOP THE LOW LEVEL JET
ON THE PRINCE WILLIAM SOUND SIDE WITH NO DOWNSLOPING. THIS WILL BE
THE KEY FEATURE TO FOCUS ON FOR THIS FORECAST PACKAGE. THE EAST
DOMAIN PREFERRED A BLEND OF THE 20/06Z NAM AND 20/00Z GFS WHILE
THE WEST DOMAIN PREFERRED THE 20/00Z GFS.
&&
.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (DAYS 1 AND 2)...
TODAY STARTS OFF WITH A LEADING FRONT AND SHORTWAVE TROUGH
APPROACHING THE NORTH GULF COAST...BRINGING A MIXTURE OF RAIN AND
SNOW TO SEA LEVEL ALONG THE COAST AND SNOW TO HIGHER ELEVATIONS
ALONG THE COAST. THIS FRONT STALLS OUT TOWARD THE EVENING HOURS AS
THE JET RAMPS UP AND SHOULD BRING SOME LIGHT SNOW OVER THE
MOUNTAINS TO THE COOK INLET REGION WHILE COASTAL AREAS SEE STEADY
MODERATE RAIN. AROUND THE ANCHORAGE AREA THE BEST CHANCE TO SEE
ACCUMULATING SNOW COMES DURING THE MID TO LATE MORNING HOURS. AS
CROSS BARRIER FLOW INCREASES AND DOWNSLOPE FLOW WARMS A LITTLE BIT
SOME RAIN COULD BEGIN TO MIX IN WITH THE SNOW. IN THE AFTERNOON
HOURS...THE UPPER LEVEL DISTURBANCE CROSSES THE MOUNTAINS AND
BRINGS SOUTHERLY FLOW UP THE INLET ALONG WITH SOME COLD ADVECTION.
THE FORECAST HERE GETS A LITTLE BIT TRICKIER...TEMPERATURES OFF
THE SURFACE WOULD SUGGEST SNOW...ESPECIALLY WITH SOUTHERLY COLD
ADVECTION UP THE INLET...HOWEVER ANY AIR COMING THROUGH TURNAGAIN
ARM IS GOING TO BE ABOVE FREEZING MEANING PRECIPITATION TYPE WILL
BE DEPENDENT ON PRECIPITATION INTENSITY. LIGHTER PRECIPITATION
WILL RESULT IN RAIN OR A RAIN SNOW MIX WHILE HEAVIER PRECIPITATION
COULD BE A 34 DEGREE SNOW. THE FRONT MOVES INLAND AND BRINGS A
MORE SHOWERY REGIME ALOFT WITH THE MAJORITY OF RAIN/SNOW HUNG UP
ALONG THE COAST...THOUGH SOME SHOWERS COULD MAKE IT OVER THE
MOUNTAINS. UNCERTAINTY IS STILL PRETTY HIGH WITH THIS INCOMING
SYSTEM...THE SYNOPTIC PATTERN IS NOT A COMMON ONE AROUND HERE. A
VARIETY OF OUTCOMES ARE POSSIBLE AND THE DETAILS MAY NOT REVEAL
THEMSELVES UNTIL VERY CLOSE TO THE EVENT...STAY TUNED.
&&
.SHORT TERM FORECAST SOUTHWEST ALASKA (DAYS 1 AND 2)...
MOST OF THE ACTIVE WEATHER OVER THE SOUTHWEST THIS WEEKEND WILL
CENTER AROUND THE LOW AND ASSOCIATED FRONT CURRENTLY MOVING
THROUGH THE WESTERN GULF. THIS LOW WILL BRING A CHANCE OF SNOW
MAINLY TO WESTERN BRISTOL BAY STARTING LATE THIS AFTERNOON AND
CONTINUE INTO EARLY SUNDAY MORNING. THE HEAVIEST ACCUMULATIONS
SHOULD OCCUR OVER HIGHER ELEVATIONS NORTH AND WEST OF
DILLINGHAM...THOUGH A FEW INCHES OF NEW SNOWFALL SHOULD STILL FALL
OVER THE LOWER ELEVATIONS. TO THE EAST OF DILLINGHAM...DOWNSLOPING
FROM EASTERLY FLOW ALONG THE ALEUTIAN RANGE WILL PREVENT ANYTHING
MORE THAN A FEW PASSING SNOW SHOWERS THIS MORNING. GUSTY EASTERLY
WINDS WILL ALSO INCREASE THIS MORNING...MAINLY ALONG THE ALEUTIAN
RANGE...AND THEN CONTINUE INTO SUNDAY AS THE SURFACE LOW MOVES
INTO BRISTOL BAY. A CHANCE OF SNOW WILL MOVE INTO THE KUSKOKWIM
DELTA AND VALLEY ON SUNDAY...HOWEVER WITH CONTINUED EASTERLY FLOW
AND MINIMAL MOISTURE THESE SHOULD NOT BE TOO WIDESPREAD WITH
LITTLE SNOW ACCUMULATION.
&&
.SHORT TERM FORECAST BERING SEA/ALEUTIANS (DAYS 1 AND 2)...
MUCH OF THE BERING SEA WILL REMAIN RELATIVELY QUIET THROUGH THIS
WEEKEND AS SNOW SHOWERS AND WINDS BEGIN TO DIMINISH TO GENERALLY
BELOW GALE FORCE. THE LOW APPROACHING THE AKPEN LATE TONIGHT WILL
BRING WIDESPREAD NORTHERLY WINDS THROUGHOUT THE BERING ALONG WITH COLD
AIR ADVECTION SNOW SHOWERS. A FRONTAL SYSTEM APPROACHING THE
WESTERN ALEUTIANS LATE SUNDAY WILL THEN BRING EASTERLY GALE FORCE
WINDS ALONG RAIN/SNOW TO THAT AREA INTO EARLY NEXT WEEK.
&&
.LONG TERM FORECAST (DAYS 3 THROUGH 7)...
THE OVERALL SYNOPTIC PATTERN FOR THE MID TO LONG TERM HAS CHANGED
LITTLE FROM YESTERDAY WITH MODELS CONTINUING TO SHOW A LARGE
AMPLITUDE RIDGE SPANNING FROM THE BROOKS RANGE SOUTHWARD ALONG THE
CONTINENTAL DIVIDE INTO THE WESTERN CONUS AND A BROAD TROUGH OVER
THE NORTHERN PACIFIC WITH CENTERS NEAR THE ALASKA PENINSULA AND
THE SEA OF OHKOSK.
AT THE SURFACE...A 960-970 MB LOW IS EXPECTED TO PROGRESS EASTWARD
ALONG THE ALEUTIAN CHAIN FROM SUNDAY EVENING TO A POSITION SOUTH
OF ADAK BY LATE MONDAY EVENING. BY TUESDAY MORNING...THIS SYSTEM
WILL BEGIN TO MERGE WITH A 980MB LOW MOVING UP FROM THE NORTH
PACIFIC...FORMING A BROAD 960-970MB LOW IN THE CENTERED IN THE
VICINITY OF DUTCH HARBOR. THIS WILL PUT MOST OF THE FORECAST AREA
IN A BROAD CYCLONIC FLOW WITH SOUTH TO EASTERLY FLOW OVER MOST OF
SOUTHERN/SOUTHWESTERN ALASKA AND MAINLY NORTHEAST FLOW OVER THE
BERING SEA. THIS BROAD LOW IS EXPECTED TO CONTINUE FOR THE
REMAINDER OF THE FORECAST PERIOD WITH SHORTWAVES ROTATING AROUND
THE PARENT LOW.
THIS PATTERN WILL KEEP GENERALLY WET AND WARM WEATHER ALONG THE
NORTH GULF COAST AND PRODUCE A WARMING TREND THROUGH THE WEEK FOR
THE INTERIOR AREAS OF SOUTHERN/SOUTHWESTERN ALASKA.
&&
.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...WINTER WEATHER ADVISORY FOR BLOWING SNOW 131.
MARINE...STORM WARNING 119 120 130 131 138.
GALE WARNING 125 127 150 160 173 174 180 132 136 137
139 141.
&&
SYNOPSIS AND MODEL DISCUSSION...JPW
SOUTHCENTRAL ALASKA...MTL
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...DEK
LONG TERM...TPHeavy Snow, Wrn P.W. Snd & Kenai Mtns
- When
- February 20, 3:01 PM AKST to February 21, 12:00 AM AKST
- Where
- Wrn P.W. Snd & Kenai Mtns forecast zone
- Reported by
- Department of Highways
Snow stake at Turnagain Pass indicated 2 feet of fell snow over 7 hours.
Heavy Snow, Kenai Peninsula
- When
- February 20, 3:59 PM AKST to February 21, 9:00 PM AKST
- Where
- Kenai Peninsula forecast zone
- Reported by
- Department of Highways
DOT reported 12 - 16 inches of new snow in Homer downtown since 8 a.m. North Fork area near homer reported 30 inches. The Homer bluff reported 24 inches.
- 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.
- Flash Flood and Flooding in Iowa, February 20 to 26, 2016$400,000 · 8 events
- Dense Fog in Illinois, February 20, 201619 events
- High Surf in Guam, February 20 to 25, 20161 injured · 1 event
- Dense Fog in California, February 20 to 21, 20167 events
- Dense Fog in Indiana, February 20, 20166 events
- Dense Fog in Missouri, February 20, 20165 events
- Hail in Missouri, February 20, 20160.88 in hail · 4 events
- Dense Fog in Kentucky, February 20, 20163 events
- Dense Fog in California, February 20 to 21, 20161 event
- Hail in Illinois, February 20, 20160.88 in hail · 1 event
- High Wind in Alaska, February 20 to 21, 201656 kt wind · 1 event
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: 616176, 616178.