The Winter of 2009-2010
Snowstorms of This Winter-Click here Snowstorms of Past Winters-Click here
Obs. Num. Time of Observation January
30   2010
Total Frozen Precip. Inches Total Melted Precip. Inches Temp. F Remarks for the Time Period
   0     0415 hrs.    Trace  Trace  23.1   The snow just started with a dew point of 10 F. This is a very dry cold air mass for the Richmond area. From the time the radar showed the first snow aloft to the time the snow made it to the ground was five to six hours.
   1      0515 hrs.   0.1   T   19.8   Snow increased around 0500 but extremely light until then. Also the snow is very dry and light with low liquid content with about a 15 to 1 ratio.
   2      0600 hrs.   0.4  0.04   19.2   By 530 the ground was white in areas without grass and the snow rate was moderate. But the snowfall rate average for the hour was light as we only gained 0.3 inches. The flakes are mainly light small aggregates of snow with some individual crystals mixed in with the aggregates.
   3      0700 hrs.    1.0  0.07   19.0  Moderate snow this past hour. Snow pellets from around 0645 to the present time also the snow shows moderate riming. This generally means convection aloft. Also some well formed six sided snow crystals but showing a moderate amount of riming makes the crystal forms more muted.
   4      0800 hrs.   1.6  0.13  19.0  Moderate snow this past hour. Snow crystals are broken and irregular and small and a few snow needles seen during this observation period.
   5      0900 hrs.    2.9   0.18   18.7  Heavy snow this past hour and visibility cut to less than .4 miles. Snow falling faster than it is being melted. Liquid amount is more than recorded here but the auxiliary heat source was put on and will catch up by the next hour.
   6      1000 hrs.    4.6  0.35   18.9  Very heavy snow this past hour and visibility cut to less than .4 miles still. Snow crystals are broken and irregular and small and a few snow needles seen during this observation period. Most everyone thinks most snow crystals are beautiful dendrites when in fact most snowflakes are broken and interfused as aggregates .
   7      1100 hrs.   5.9  0.48  18.4  Very heavy snow this past hour and visibility cut to less than .4 miles still.
   8      1200 hrs.   7.9  0.63  18.1   The pressure is falling rapidly and very heavy snow again this past hour and visibility cut to less than .4 miles still. Liquid amount is more than recorded here because even with the auxiliary heat source it can't keep up with melting the snow as the snowfall rate is too much for it.
   9      1300 hrs.   9.4   0.80  18.5  The pressure is falling rapidly and very heavy snow again this past hour and visibility cut to less than .4 miles still. Liquid amount is more than recorded here because even with the auxiliary heat source increased from 40 watts to 75 watts to try and keep up melting with the snow as the snowfall rate was too much for it. It should catch up with the melting by the end of the next hour!! See the snow camera at ( http://glenallenweather.com/snowcamera.htm ) It updates now every 5 minutes. The camera will need to be raised the next hour if this snow rate continues.
  10    1400 hrs.   9.6   0.94   17.9   Snowfall rate decreased to light to moderate and the heat source did finally catch up to the snowfall rate and all of the snow is melted in the tripping bucket gauge!! The maximum wind so far is 20 mph which has been enough to cause minor drifting but mainly blowing snow off of roofs. The snow is so light that it is easy to blow around.
  11    1500 hrs.   10.5  1.05  18.4   Some heavy snow during this past hour but the wind is blowing some snow away from the area of the snow board so the measurement is a little lower in that area where the snow camera is located.
  12    1600 hrs.    11.3  1.13  17.9   The snow is still moderate to heavy with 0.8 inches of snow the past hour and 0.08 liquid equivalent this past hour. The wind is making it hard to get accurate measurements. We had one gust to 21 MPH.
  13    1700 hrs.   11.4   1.14   17.6  The snow is starting to taper off now and we are near the back edge of the precipitation as seen on the radar. However we may get some more snow tonight from the snow wrapping around the low pressure. At observation time we are now getting some snow pellets.
  14    1800 hrs.   11.4   1.14  17.3   A few comments about this storm - I believe the water equivalent is too low as some snow blew off the roof into the tripping bucket gauge. I have a standing 8 inch diameter gauge that is located a much greater distance from the house and will check this tomorrow and post it below as a final. But the storm is over and this is the last observation.
  15    Final     12.1  1.24     An additional 0.7 inches of snow fell during the night ending at 0220 that yielded 0.05 inches of liquid. The 1.24 inches was obtained from a core sample and a total of 12.1 Inches. The minimum temperature last night was 7.0 F the lowest minimum temperature since January 17, 2009 when the minimum temperature was 4 F.