Heavy Snow in Alaska, April 17, 2008

Name: Heavy Snow in Alaska, April 17, 2008
Start: 2008-04-17T05:05
End: 2008-04-17T09:00
Location: Alaska

April 17, 2008 · NWS AJK · 1 event in 1 county or zone

A cold upper low moved over the Panhandle on 4/17. A 1003 MB surface low center over Cape Spencer on the afternoon of 4/16 weakened to 1010 MB over Juneau on the morning of 4/17.

The toll

Deaths: 0
Injuries: 0
Property damage: None recorded
Crop damage: None recorded
Events: 1

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.

A cold upper low moved over the Panhandle on 4/17. A 1003 MB surface low center over Cape Spencer on the afternoon of 4/16 weakened to 1010 MB over Juneau on the morning of 4/17. An unseasonable arctic front formed over the northern Panhandle that afternoon and moved to southern SE Alaska by the evening of 4/17.

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 Apr 17, 12:00 AM AKST, 5 hours 5 minutes earlier.

Area forecast discussion, Apr 17, 12:00 AM AKST, 5 hours 5 minutes before

SOUTHEAST ALASKA FORECAST DISCUSSION
600 AM ADT THU APR 17 2008

.SYNOPSIS...
.SHORT RANGE...EXTRAORDINARY SNOW EVENT FOR INNER CHANNELS IN NRN

HLF OF PNHDL AT THIS TIME.  HEAVIEST 12 HR SNOW AMOUNTS ARE IN
THE CITY AND BOROUGH OF JUNEAU WITH 6 TO 12 INCHES EXPECTED BY 10
AM.

A COLD FRONT IS MOVING S THROUGH THE PNHDL AND IS LIFTING A
CONVECTIVE LAYER WITH HIGH PRECIPITABLE WATER VALUES.  A STRONG
DIFFERENTIAL OF VORTICITY ADVECTION IN THE VERTICAL SHOULD BE
ASSOCIATED WITH THIS EVENT.  AN E-W CROSS SECTION OF THE NAM
MODEL OVER JUNEAU INDICATES THE BEST LAYER OVER JUNEAU TO BE FM
ABT 700 MB TO T0 500H, USING A LOW RESOLUTION VERSION OF THE
MODEL.  12Z PAYA RAOB SHOWS LOW LEVEL FNTL LAYER FM 925MB TO
850MB, BUT DEEP CNVTV LAYER FM 850 MB TO 500 MB.

THE PARENT TROUGH ALOFT IS MOVG SE AND THE MAIN SNOW EVENT SHOULD

END LATE THIS MORNING.  THE GOES IR INDICATES A SMALL AND STRONG
CIRCULATIONS MOVING E ACRS THE NRN HLF OF THE PNHDL DURING THE
LAST 6 HRS, HWVR THE CIRCULATIONS ARE BCMG WEAKER AT THIS TIME.
THE PARENT TROUGH ALOFT WILL MOVE SOUTH TO DIXON ENTRANCE
TONIGHT. HIGH PRESSURE WILL CONTINUE TO BUILD INTO THE PANHANDLE
FROM THE NORTH THROUGH FRIDAY.

THE ARCTIC OUTBREAK WILL GEN BE OBVIOUS WITH WINDSHIFTS, ALONG
WITH TEMPERATURE, FALLS AS THEY OCCUR IN A N TO S SEQUENCE ALG
THE PNHDL. THE FIRST OCCURRED LAST NIGHT WITH SKAGWAY BCMG N AND
TEMPERATURE FALLING 8 DEG F FM 0600Z T0 0713Z.

THE TRANSITION TO DRIER CONDITIONS IS ALREADY UNDERWAY IN HAINES
AND SKAGWAY AT THIS TIME. THE DRYG WILL CONT TO SPREAD SE ALONG
THE PNHDL AND REACH THE REMAINDER BY ABT 12Z FRI.

.LONG RANGE...MODELS IN GOOD AGREEMENT ON A BLOCKING PATTERN
DEVELOPING OVER THE NE PAC BY FRI...THEN PERSISTING INTO LATE
NEXT WEEK. MODELS HAVE SOME DIFFERENCES ON EXACT LOCATION AND
SHAPE OF THE DOMINANT UPPER HIGH NEARBY...BUT THESE DIFFERENCES
FOR THE MOST PART WILL HAVE LITTLE CONSEQUENCE ON THE SENSIBLE
WEATHER. AFTER COORD WITH WFO PAFC...DECIDED TO USE THE NEW GFS40
FROM SAT NIGHT ONWARD.

SO...IT WILL START OUT RATHER COOL FOR THE FIRST PART OF THE LONG
RANGE...THEN WARM UP FOR NEXT WEEK...WITH MAX TEMPS LIKELY
REACHING ABOVE NORMAL LEVELS BY AROUND TUE. MAX TEMPS WERE
GENERALLY RAISED SEVERAL DEGREES ESPECIALLY FROM SUN ONWARD...AND
LATER SHIFTS MAY NEED TO RAISE THEM EVEN MORE. THE NIGHTS WILL
REMAIN ON THE COOL SIDE THRU THE WEEKEND...THEN THEY SHOULD SEE
MODERATION NEXT WEEK AS WELL. MIN TEMPS WERE GENERALLY LEFT AS
THEY WERE WITH A FEW MINOR ADJUSTMENTS HERE AND THERE.

AN ADJUSTMENT THAT WAS MADE WAS TO THE CLOUD COVER FOR MUCH OF
THE WEEKEND. IT LOOKS LIKE A BAND OF ELEVATED WARM ADVECTION
INDUCED HIGH AND MIDDLE CLOUDS WILL DRIFT OVER THE NRN AREAS FROM
THE NW FOR LATE SAT INTO SUN...BUT AS THEY CONTINUE SWD TOWARD
THE SRN AREA...THIN OUT RATHER QUICKLY. WENT FOR MOSTLY CLOUDY
OVER THE FAR N BEGINNING SAT...AND OVER THE REMAINDER OF THE N
BEGINNING SAT NIGHT. THESE CONDITIONS WERE KEPT THRU MON...THEN
IT SHOULD SCATTER OUT AGAIN. THE SRN AREAS WERE KEPT AT PARTLY
CLOUDY THRU THE PERIOD.

.AJK...WATCHES/WARNINGS/ADVISORIES
PUBLIC...HEAVY SNOW WARNING JUNEAU ZONE 25.
         SNOW ADVISORIES FOR 20>22.
         WIND ADVISORIES 18, 19, 20, 22, AND 27.

MARINE...GALE 41>43, 52, AND 310.
         SCA INSIDE 11>13, 21>22, 31>36.
         SCA OUTSIDE 51.

JT/RWT

In the hours before

Local storm report, Apr 17, 1:44 AM AKST, 3 hours 21 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE JUNEAU AK
744 AM ADT THU APR 17 2008

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0727 AM     HEAVY SNOW       2 S JUNEAU              58.36N 134.13W
04/17/2008  M4.5 INCH                           AK   PUBLIC

            AS OF 0615 AST OVERNIGHT SNOWFALL AT THANE WASTE WATER
            TREATMENT PLANT WAS 4.5 INCHES.

0727 AM     HEAVY SNOW       5 NE JUNEAU             58.44N 134.04W
04/17/2008  M6.5 INCH                           AK   TRAINED SPOTTER

            AS OF 0630 ADT 6.5 INCHES HAD FALLEN AT FRITZ COVE
            OVERNIGHT.

0727 AM     HEAVY SNOW       20 NW JUNEAU            58.59N 134.53W
04/17/2008  M9.5 INCH                           AK   PUBLIC

            AS OF 0735 ADT 9.5 INCHES HAD FALLEN NEAR 25 MILE MARKER
            OVERNIGHT

0727 AM     HEAVY SNOW       GUSTAVUS                58.41N 135.80W
04/17/2008  E4.0 INCH                           AK   AIRPLANE PILOT

            AS OF 7 AM ADT AN ESTIMATE OF 3 TO 4 INCHES HAD
            ACCUMULATED OVERNIGHT ON THE GROUND WITH 7 INCHES ON THE
            AIRCRAFT. OBSERVATION AT GUSTAVUS AIRPORT.

0727 AM     HEAVY SNOW       JUNEAU                  58.39N 134.13W
04/17/2008  M3.5 INCH                           AK   OFFICIAL NWS OBS

            AS OF 0400 ADT 3.5 INCHES OF SNOW HAD FALLEN SINCE 0100
            ADT. STORM TOTAL SO FAR 6.2 INCHES.

&&

KAV

Local storm report, Apr 17, 2:50 AM AKST, 2 hours 15 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE JUNEAU AK
850 AM ADT THU APR 17 2008

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0850 AM     HEAVY SNOW       HOONAH                  58.12N 135.45W
04/17/2008  M4.6 INCH                           AK   CO-OP OBSERVER

&&

BMB

Local storm report, Apr 17, 4:44 AM AKST, 21 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE JUNEAU AK
1044 AM ADT THU APR 17 2008

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0800 AM     HEAVY SNOW       JUNEAU                  58.30N 134.41W
04/17/2008  M12.0 INCH                          AK   CO-OP OBSERVER

            LEMON CREEK CO-OP STORM TOTAL 12 INCHES

0850 AM     HEAVY SNOW       JUNEAU                  58.30N 134.41W
04/17/2008  M7.5 INCH                           AK   OFFICIAL NWS OBS

            SNOW FALL FROM 1 AM TO 10 AM... STORM TOTAL FOR EVENT
            10.2 INCHES.

0850 AM     HEAVY SNOW       JUNEAU                  58.30N 134.41W
04/17/2008  M7.8 INCH                           AK   OFFICIAL NWS OBS

            SNOW FALL TODAY THROUGH 10 AM. STORM TOTAL FOR EVENT 12.5
            INCHES.

&&

BMB

Local storm report, Apr 17, 4:55 AM AKST, 10 minutes before

PRELIMINARY LOCAL STORM REPORT...CORRECTED
NATIONAL WEATHER SERVICE JUNEAU AK
1055 AM ADT THU APR 17 2008

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0850 AM     HEAVY SNOW       JUNEAU                  58.30N 134.41W
04/17/2008  M7.8 INCH                           AK   OFFICIAL NWS OBS

            JUNEAU FORECAST OFFICE - SNOW FALL TODAY THROUGH 10 AM.
            STORM TOTAL FOR EVENT 12.5 INCHES.

0850 AM     HEAVY SNOW       JUNEAU                  58.30N 134.41W
04/17/2008  M7.5 INCH                           AK   OFFICIAL NWS OBS

            JUNEAU AIRPORT OBSERVER - SNOW FALL FROM 1 AM TO 10 AM...
            STORM TOTAL FOR EVENT 10.2 INCHES.

&&

BMB

Event by event

1 heavy snow. Local standard time, as filed.

Heavy Snow, Juneau Borough and Northern Admiralty Island

When: April 17, 5:05 AM AKST to 9:00 AM AKST
Where: Juneau Borough and Northern Admiralty Island forecast zone
Reported by: Official NWS Observations

Juneau had a late season snowfall with rapid accumulation on 4/17. Steady rain began on 4/16 and turned to snow around midnight 4/17. By 0600 one trained spotter measured 7.5 inches of new snowfall with an additional 2 inches ending by noon. Most storm totals in town were around 9 inches by noon on 4/17. The airport storm total was 10.2 inches and the forecast office measured 7.8 inches, again, most of which fell before noon.

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 2008 Every state in 2008 This day in weather history Warnings in Alaska, April 2008

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: 95097.