beavis1729 Posted January 2, 2012 Share Posted January 2, 2012 Valdez, AK has 152.2" of snow in December 2011...which breaks the old record of 137.1" in December 1991. Strangely enough, their snow depth only increased from 25" on 12/1/2011 to 58" on 12/31/2011. And, all of this occurred with fairly normal temperatures; the highest temp recorded all month was 40F. My first instinct is that either the snowfall amounts were measured incorrectly, or the snow depths were measured incorrectly. I say this because, while there will obviously be some compaction and melting over time, I find it difficult to believe that 152.2" of snowfall in a 31-day period would only add 33" to the snow depth. As a more focused example, 59.9" of snow fell from Dec. 11-17, but the snow depth only increased by 17". I did notice that 16.26" of liquid equivalent was recorded in Dec. 2011, and some of the monthly precipitation was rain. But would a cold rain with temps in the mid-30s really melt and/or comapct the snow that quickly? Any thoughts? Have any research papers been published about this? To the average person it's probably not very interesting...but I imagine there's some cool meteorology behind this. Either way, it must have been fascinating to live in Valdez for the past 31 days! Link to comment Share on other sites More sharing options...
Hoar_Frost Posted January 2, 2012 Share Posted January 2, 2012 That's a good question. I'm actually tempted to believe that it's compaction, not measurement error. But, let's investigate. From the Midwestern Regional Climate Center's MACS database, I provide Valdez's basic data for December 1991, the month whose record was just broken: What's interesting about the 1991 case, though, is that every instance of liquid-equivalent precipitation is associated with some amount of snow. That suggests that either there was no rain (and only snow) or that any instances of rain were accompanied by snow during the same 24-hour period. Another example of a heavy monthly snow total where snow depth didn't increase as much as one might expect: Houghton County Airport on Michigan's Keweenaw Peninsula in December 1978, a blockbuster winter for snow up that way: Granted, we must be careful comparing Valdez with Houghton. Valdez's snow originates from moisture-laden Pacific storm systems, whereas most of the Keweenaw's is lake effect (and fluffier--higher ratio). Also, the temperatures in the Houghton case were much warmer than the Valdez. However, fluffier snow tends to compact more easily, all else equal, so the colder temperatures might balance out Valdez's warmer temperatures' compacting capabilities. Overall, with these couple of brief investigations, I'm more convinced that measurement error is not at fault here. Snow really does compact more than we realize. Perhaps others have input to offer from a more physical (and perhaps rigorous) perspective. Link to comment Share on other sites More sharing options...
beavis1729 Posted January 2, 2012 Author Share Posted January 2, 2012 Thanks for the reply. I must admit that it's hard to disagree with your thoughts, considering that Dec. 1991 featured a similar story in Valdez. The Houghton numbers actually surprise me more, given the colder temps! Yes, I'd expect some of that because it's mostly lake-effect, but still... In Valdez, you may also see see significant melting from below, as the soil temperatures probably stay fairly warm throughout the winter. Interesting... Link to comment Share on other sites More sharing options...
famartin Posted January 2, 2012 Share Posted January 2, 2012 Valdez, AK has 152.2" of snow in December 2011...which breaks the old record of 137.1" in December 1991. Strangely enough, their snow depth only increased from 25" on 12/1/2011 to 58" on 12/31/2011. And, all of this occurred with fairly normal temperatures; the highest temp recorded all month was 40F. My first instinct is that either the snowfall amounts were measured incorrectly, or the snow depths were measured incorrectly. I say this because, while there will obviously be some compaction and melting over time, I find it difficult to believe that 152.2" of snowfall in a 31-day period would only add 33" to the snow depth. As a more focused example, 59.9" of snow fell from Dec. 11-17, but the snow depth only increased by 17". I did notice that 16.26" of liquid equivalent was recorded in Dec. 2011, and some of the monthly precipitation was rain. But would a cold rain with temps in the mid-30s really melt and/or comapct the snow that quickly? Any thoughts? Have any research papers been published about this? To the average person it's probably not very interesting...but I imagine there's some cool meteorology behind this. Either way, it must have been fascinating to live in Valdez for the past 31 days! Here's their daily data: 000 CXAK56 PAVW 011838 CF6VWS PRELIMINARY LOCAL CLIMATOLOGICAL DATA (WS FORM: F-6) STATION: VALDEZ MONTH: 12 YEAR: 2011 LATITUDE: 61 08 N LONGITUDE: 146 21 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 35 30 33 7 32 0 0.50 2.8 25 2.4 9 80 M M M 1 14 80 2 34 32 33 7 32 0 0.92 7.6 29 1.6 3 350 M M M 1 6 360 3 34 31 33 7 32 0 0.38 3.8 26 2.2 5 70 M M M 1 8 220 4 39 32 36 10 29 0 2.80 2.8 27 4.1 13 270 M M M 28 270 5 39 20 30 4 35 0 T 0.0 25 4.9 10 330 M M M 1 18 270 6 23 13 18 -8 47 0 0.00 0.0 25 2.8 7 100 M M M 10 40 7 27 17 22 -4 43 0 0.15 2.0 26 2.5 7 300 M M M 13 50 8 31 25 28 2 37 0 0.76 12.0 37 1.6 5 90 M M M 1 7 90 9 34 27 31 5 34 0 0.34 5.0 41 1.3 4 90 M M M 1 7 151 10 25 14 20 -6 45 0 0.00 0.0 38 3.1 7 80 M M M 1 9 270 11 40 23 32 6 33 0 1.40 20.3 44 3.7 15 80 M M M 1 29 80 12 37 32 35 9 30 0 0.54 1.6 43 4.6 16 230 M M M 1 24 70 13 34 24 29 3 36 0 0.09 2.6 40 3.9 8 40 M M M 1 18 40 14 31 26 29 3 36 0 0.43 7.2 45 2.4 3 60 M M M 1 8 60 15 35 25 30 4 35 0 0.62 6.7 42 2.6 8 90 M M M 1248 21 90 16 34 32 33 7 32 0 0.59 1.5 44 3.3 9 130 M M M 1 15 130 17 34 30 32 6 33 0 1.24 20.0 54 2.3 5 70 M M M 12 30 18 38 32 35 9 30 0 1.14 0.9 47 5.2 17 70 M M M 30 70 19 36 31 34 8 31 0 0.38 0.4 45 3.2 9 230 M M M 2 14 240 20 37 30 34 8 31 0 0.73 8.5 50 4.9 9 60 M M M 1248 21 70 21 37 29 33 7 32 0 0.79 3.7 45 5.2 9 270 M M M 1248 20 90 22 34 24 29 3 36 0 0.06 1.1 40 10.4 28 120 M M M 45 120 23 31 29 30 4 35 0 0.37 12.0 45 6.2 18 240 M M M 25 240 24 30 25 28 2 37 0 0.06 2.6 49 3.4 8 50 M M M 1 18 50 25 27 22 25 -1 40 0 0.43 6.8 53 6.6 12 70 M M M 25 70 26 33 20 27 1 38 0 0.03 1.0 52 11.4 30 120 M M M 9 48 90 27 27 22 25 -1 40 0 0.36 5.1 53 6.0 14 70 M M M 1 26 40 28 27 24 26 1 39 0 0.29 3.7 54 4.0 8 40 M M M 18 40 29 26 21 24 -1 41 0 0.28 3.8 56 5.2 9 90 M M M 1 16 80 30 24 18 21 -4 44 0 0.35 3.3 57 6.1 20 260 M M M 1 30 270 31 20 17 19 -6 46 0 0.23 3.4 58 5.4 8 70 M M M 1 16 70 ================================================================================ SM 993 777 1121 0 16.26 152.2 132.5 M M ================================================================================ AV 32.0 25.1 4.3 FASTST PSBL % M MAX(MPH) MISC ----> 30 120 48 90 ================================================================================ NOTES: # LAST OF SEVERAL OCCURRENCES COLUMN 17 PEAK WIND IN M.P.H. PRELIMINARY LOCAL CLIMATOLOGICAL DATA (WS FORM: F-6) , PAGE 2 STATION: VALDEZ MONTH: 12 YEAR: 2011 LATITUDE: 61 08 N LONGITUDE: 146 21 W [TEMPERATURE DATA] [PRECIPITATION DATA] SYMBOLS USED IN COLUMN 16 AVERAGE MONTHLY:28.5 TOTAL FOR MONTH:16.26 1 = FOG DPTR FM NORMAL: 2.6 DPTR FM NORMAL: 8.02 2 = FOG REDUCING VISIBILITY HIGHEST: 40 ON 11 GRTST 24HR 2.80 ON 4 TO 1/4 MILE OR LESS LOWEST: 13 ON 6 3 = THUNDER SNOW, ICE PELLETS, HAIL 4 = ICE PELLETS TOTAL MONTH: 152.2 INCHES 5 = HAIL GRTST 24HR 20.3 ON 11 6 = GLAZE OR RIME GRTST DEPTH: 58 ON 31 7 = BLOWING DUST OR SAND: 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: 13 0.01 INCH OR MORE: 28 MAX 70 OR ABOVE: 0 0.10 INCH OR MORE: 24 MIN 32 OR BELOW: 31 0.50 INCH OR MORE: 12 MIN 0 OR BELOW: 0 1.00 INCH OR MORE: 4 [HDD (BASE 65) ] TOTAL THIS MO. 1121 CLEAR (SCALE 0-3) M DPTR FM NORMAL -93 PTCLDY (SCALE 4-7) M SEASONAL TOTAL 4365 CLOUDY (SCALE 8-10) M DPTR FM NORMAL 33 [CDD (BASE 65) ] TOTAL THIS MO. 0 DPTR FM NORMAL 0 [PRESSURE DATA] SEASONAL TOTAL 0 HIGHEST SLP M DPTR FM NORMAL 0 LOWEST SLP M [REMARKS] #FINAL-12-11# Anyway, the short answer is "yes", it can happen with compaction. Note that there were many days in the mid 30s. Link to comment Share on other sites More sharing options...
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