Friday 11th February

Dan Johnson and Janice Coen

2040 Z -- Microvan left Foothills Lab, heading NE towards a site E of
Greeley for coordinated filter samples with Electra, which was to be
flying soon. Conditions: convective clouds, flat, darkening cloud bases, 
virga (strongly sheared) falling everywhere.

2156 Z -- Driving east of Greeley. Strong winds from north.  Light-
moderate snowfall of aggregates.  Overcast - visibility 2-3 miles.

2230 Z -- Set up at about 25.5 km at 70 degrees to CHILL.  (Lat.: 40
deg. 28' 49", Lon: 104 deg. 18' 17").  11 km E of Barnesville at (E-W)
Rd. 68 and (N-S) Rd. 81.

2250-2303 Z -- In a snow band, heavy snow (whiteout). Winds: steady 
35 mph winds from N. Crystals: Heavily rimed spatial crystals.

2320-2324 Z -- Ops reported we were in between bands.  Wind blowing steady 
at 25-35 mph from N.  Visibility - less than 1 mile. Many snow crystals, 
all 100-200 microns.

2337 Z -- Second snow band arrived.  Wind still 25-35 mph from N.
Crystals: tiny pristine planar crystals.

2345 Z -- Blowing snow, may or not be snowing. Winds shifted to NW-NNW,
picked up to 40-45 mph. (Very difficult to stand.)

2354 Z -- Winds still strong - about 35 mph from N again.  Blowing
snow, none falling.  Scattered scud cloud against grey background,
clearing to N.  Dark grey sky to S.

0009 Z -- Blowing hard.  Possible light snow.  Many tiny planar crystals
(100-200 microns) with a few mm-sized dendrites.

0023-0030 Z -- Very windy (over 45 mph from N). Blowing snow, light 
snowfall.

0034 Z -- In a snowband.  Crystals: Heavily rimed globs with some 
plate-like growth.

0043-0049 Z -- Blowing steadily over 45 mph from N. Snowing hard, larger 
crystals. Crystals: heavily-rimed side planes (1-2 mm).

0109 Z -- (Now dark.) Snow decreased, and winds weakened to 25 mph from N.

0115 Z -- Snowing heavily again.
Crystals: Pristine side planes, a few columns, a plate.

0132 Z -- Moderate snow and wind.  Crystals: moderately-rimed side 
planes, one clean plate.

0148 Z -- Wind blowing at 35 mph, blowing snow.

0204 Z -- Strong winds, heavy snow.  Crystals: Rime character changes to
feathery: Heavily-rimed (aggregates of?) side planes, a capped column.

0230-0256 Z -- Wind has dropped to 25 mph.  Moderate snowfall, larger 
flakes.  Crystals: Feathery, hairy rimed side-planes.

0256 Z -- Packed up.  Reports of road closings N of Greeley, accidents.


Snow Samples in Petri dishes (photographs and video running):

(1) 2303 Z - Heavily rimed spatial crystals

(2) 2331 Z - No success. Too windy, nothing falling into dish.

(3) 2339 Z - Tiny crystals.

(4) 0034 Z - In a snowband.  Heavily rimed globs with some platelike
growth.

(5) 0045 Z - Heavily-rimed side planes (1-2 mm).

(6) 0056 Z - Heavily-rimed side planes.

(7) 0116 Z - Side planes, a few columns, a plate.  No rime.

(8) 0132 Z - Moderately-rimed side planes, one clean plate.

(9) 0204 Z - Rime character changes to feathery: Heavily-rimed
(aggregates of?) side planes, a capped column.

(10) 0236 Z - Feathery, hairy rimed side-planes.


Snow Samples on slides:

(1) 0029 Z - on NuSkin in brake fluid and empty testtube

(2) 0113 Z - on NuSkin in brake fluid and empty testtube

(3) 0231 Z - on oil in brake fluid and empty testtube


Filter Samples:  (2.5 liters/min flow rate)

(1) 2311 Z - 2350 Z

(2) 2354 Z - 0036 Z

(3) 0123 Z - 0207 Z

(4) 0222 Z - 0256 Z ?


Snow Chemistry Vials:

(1) 0101 Z -- Stopped 2 chemistry vials.

(2) 0148 Z -- Stopped 2 chemistry vials.

(3) 0254 Z -- Stopped 2 chemistry vials.