Weather Blog

Mountain snowpack and other weather musings

Mountain snowpack and other weather musings


With the late winter-like weather continuing, there's plenty of neat statistics to catch up on besides the one we had yesterday about this being the 7th coldest March ever.

* We had a trace of snow on April 1st, the first time it's snowed on April 1st since 1976. Not surprisingly, that was the last time we had a March whose average temperature was under 42 degrees. However, the trace doesn't count as an actual measurement, so 2009 remains tied for No. 6 snowiest winter, and I'll bet it'll stay there.

* Also, with March ending, we can now say this was the third coldest winter (defined as between Dec. 1 and Mar. 31) since 1958, with an average temperature of 39.8 degrees. We've also had 67 days of rain since Dec. 1 (through Mar. 31) about on par with the usual 70.

* The actual high on Wednesday was 46 degrees. Believe it or not, the record high for the date was 82.  Hard to fathom that, huh? :)

* Spokane keeps climbing up their snowy chart. They were already at snowiest winter ever, but now they're padding their lead. With 4" of snow Wednesday night into Thursday morning, they are approaching 100" of snow for the year. We'll see tonight what the official measurement was from this morning.

* The recent snow has done wonders to our mountain snowpack. Here is the current tally as of April 1:

CLIMATOLOGICAL SNOWDEPTH INFORMATION
NORTHWEST WEATHER AND AVALANCHE CENTER SEATTLE WASHINGTON
DAY 1 MONTH 4 YEAR 2009

DATA IN INCHES, -99 DENOTES MISSING DATA

CURRENT CLIMATE PER CENT LAST THRU 2008 THRU 2008
DEPTH AVERAGE OF NORMAL YEAR MAX/YEAR MIN/YEAR

HURRICANE 93 106 88 137 252/1999 42/2005
MT BAKER 143 174 82 197 311/1999 72/1934
STEVENS 115 101 114 131 192/1956 24/1941
SNOQUALMIE 102 86 119 131 170/1956 2/1992
STAMPEDE 127 100 127 144 183/1956 17/1992
MISSION 49 46 107 55 86/1983 20/1973
CRYSTAL 93 70 133 105 144/1999 16/1981
PARADISE 185 175 106 240 327/1956 66/1941
WHITE PASS 98 54 181 95 110/1997 0/1992
TIMBERLINE 199 163 122 225 300/1999 57/1981
MEADOWS 166 128 130 199 199/2008 49/2005

THIS TABLE PRODUCED ON THE 1ST AND 15TH BETWEEN 15 NOVEMBER AND 1 MAY.

AVERAGES, MAXIMUMS AND MINIMUMS EARLY AND LATE IN THE SEASON MAY BE
INACCURATE DUE TO LIMITED DATA.

This is quite a bit more than the chart from March 15. By the way, if you want to see how much snow has fallen in the mountains recently, head to the Northwest Avalanche Center site.   This has current weather conditions from their automated sites up there.

For example, here is Snoqualmie Pass' chart. This chart is a bit confusing, but there's two tricks. Under the column "24 hr Snow 3,000'", it's a cumulative number that resets every so often. So if you see, say, the number count up to 10, then reset and climb back to 4, that means 14" of snow since the start of the chart.

The number to the right under "total snow" is the snowpack, but note that snow compresses into the snowpack, so it's possible to see 14" of snow fall, but the snowpack total only increase by 8".  Also, these are automated gauges and prone to errors so it's not exact, but a general idea.

And to finish this off, here is the March month in review, for those who like to keep track. (Note the large number of negative numbers in the "departure form normal" column! ('DEP') )

PRELIMINARY LOCAL CLIMATOLOGICAL DATA (WS FORM: F-6)

STATION: SEATTLE-TACOMA WA AIRPORT
MONTH: MARCH
YEAR: 2009
LATITUDE: 47 27 N
LONGITUDE: 122 18 W

TEMPERATURE IN F: :PCPN: SNOW: WIND :SUNSHINE: SKY :PK WND
================================================================================
1 2 3 4 5 6A 6B 7 8 9 10 11 12 13 14 15 16 17 18
12Z AVG MX 2MIN
DY MAX MIN AVG DEP HDD CDD WTR SNW DPTH SPD SPD DIR MIN PSBL S-S WX SPD DR
================================================================================

1 57 44 51 6 14 0 0.30 0.0 0 7.9 18 120 M M 10 1 25 120
2 57 44 51 6 14 0 0.11 0.0 0 11.4 30 230 M M 7 1 39 160
3 55 42 49 4 16 0 0.24 0.0 0 6.0 23 40 M M 8 1 30 40
4 46 40 43 -2 22 0 0.03 0.0 0 7.1 25 220 M M 9 35 210
5 45 34 40 -5 25 0 0.05 0.0 0 10.1 31 220 M M 8 158 39 220
6 45 28 37 -8 28 0 0.00 0.0 0 5.5 12 140 M M 2 18 110
7 45 31 38 -7 27 0 0.08 0.3 0 13.3 25 190 M M 9 1 32 230
8 40 30 35 -10 30 0 0.32 T 0 4.8 12 20 M M 8 1 13 20
9 37 31 34 -11 31 0 0.34 2.2 2 9.3 20 350 M M 9 18 24 350
10 40 27 34 -12 31 0 0.00 0.0 1 5.5 14 30 M M 5 16 10
11 44 26 35 -11 30 0 0.00 0.0 0 9.9 17 360 M M 2 31 350
12 51 29 40 -6 25 0 0.00 0.0 0 8.4 15 10 M M 2 17 10
13 55 33 44 -2 21 0 0.00 0.0 0 7.2 18 220 M M 8 22 230
14 45 38 42 -4 23 0 0.49 0.0 0 12.8 23 190 M M 10 1 31 200
15 46 33 40 -6 25 0 0.69 0.5 0 16.3 32 210 M M 8 1 47 200
16 44 35 40 -6 25 0 0.29 0.0 0 11.8 25 200 M M 9 1 30 230
17 46 35 41 -5 24 0 0.29 T 0 10.1 21 190 M M 6 1 25 190
18 54 38 46 0 19 0 T 0.0 0 6.0 26 330 M M 9 28 330
19 50 43 47 1 18 0 0.08 0.0 0 6.7 14 190 M M 9 18 18 200
20 56 36 46 -1 19 0 0.12 0.0 0 9.3 29 240 M M 9 1 38 250
21 49 29 39 -8 26 0 T 0.0 0 3.9 12 230 M M 6 128 16 210
22 49 39 44 -3 21 0 0.01 0.0 0 11.1 23 210 M M 9 30 210
23 46 37 42 -5 23 0 0.07 0.0 0 9.3 18 210 M M 9 1 23 220
24 48 40 44 -3 21 0 0.01 0.0 0 14.3 25 230 M M 10 1 32 200
25 47 38 43 -4 22 0 0.05 0.0 0 6.9 21 220 M M 8 26 240
26 52 33 43 -4 22 0 0.00 0.0 0 3.6 9 150 M M 7 14 130
27 51 41 46 -1 19 0 T 0.0 0 8.0 16 220 M M 10 18 18 200
28 43 34 39 -8 26 0 0.38 0.0 0 8.6 18 300 M M 10 1 24 280
29 50 34 42 -6 23 0 0.04 T 0 3.8 14 320 M M 7 16 33 90
30 47 38 43 -5 22 0 0.00 0.0 0 11.5 21 210 M M 9 24 210
31 48 37 43 -5 22 0 0.17 0.0 0 13.1 23 200 M M 9 148 32 220
================================================================================
SM 1488 1097 714 0 4.16 3.0 273.5 M 241
================================================================================
AV 48.0 35.4 8.8 FASTST M M 8 MAX(MPH)
MISC ----> # 32 210 # 47 200
================================================================================
NOTES:
# LAST OF SEVERAL OCCURRENCES

COLUMN 17 PEAK WIND IN M.P.H.

PRELIMINARY LOCAL CLIMATOLOGICAL DATA (WS FORM: F-6) , PAGE 2

STATION: SEATTLE-TACOMA WA AIRPORT
MONTH: MARCH
YEAR: 2009
LATITUDE: 47 27 N
LONGITUDE: 122 18 W

[TEMPERATURE DATA] [PRECIPITATION DATA] SYMBOLS USED IN COLUMN 16

AVERAGE MONTHLY: 41.7 TOTAL FOR MONTH: 4.16 1 = FOG OR MIST
DPTR FM NORMAL: -4.5 DPTR FM NORMAL: 0.41 2 = FOG REDUCING VISIBILITY
HIGHEST: 57 ON 2, 1 GRTST 24HR 0.69 ON 15-15 TO 1/4 MILE OR LESS
LOWEST: 26 ON 11 3 = THUNDER
SNOW, ICE PELLETS, HAIL 4 = ICE PELLETS
TOTAL MONTH: 3.0 INCHES 5 = HAIL
GRTST 24HR 2.2 ON M 6 = FREEZING RAIN OR DRIZZLE
GRTST DEPTH: 2 ON 9 7 = DUSTSTORM OR SANDSTORM:
VSBY 1/2 MILE OR LESS
8 = SMOKE OR HAZE
[NO. OF DAYS WITH] [WEATHER - DAYS WITH] 9 = BLOWING SNOW
X = TORNADO
MAX 32 OR BELOW: 0 0.01 INCH OR MORE: 21
MAX 90 OR ABOVE: 0 0.10 INCH OR MORE: 12
MIN 32 OR BELOW: 8 0.50 INCH OR MORE: 1
MIN 0 OR BELOW: 0 1.00 INCH OR MORE: 0

[HDD (BASE 65) ]
TOTAL THIS MO. 714 CLEAR (SCALE 0-3) 3
DPTR FM NORMAL 132 PTCLDY (SCALE 4-7) 11
TOTAL FM JUL 1 4115 CLOUDY (SCALE 8-10) 17
DPTR FM NORMAL 206

[CDD (BASE 65) ]
TOTAL THIS MO. 0
DPTR FM NORMAL 0 [PRESSURE DATA]
TOTAL FM JAN 1 0 HIGHEST SLP M ON M