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Weather Diary - February 1999
- A cloudy, dry night with the F4 WSW'ly wind easing F2-3 and backing SW'ly. A sunny
morning, but clouding over during the afternoon with a S'ly wind increasing F4-5. Some
light drizzle during the afternoon and evening, the 20 km to 30 km visibility falling to
15 km in the precipitation. A mild day.
- Cloudy overnight with some light rain and a F5-6 S to SSW'ly wind. Precipitation
moderate between 0600 UTC and 0900 UTC, but then becoming dry. A generally cloudy day with
some brightness during the afternoon as the lower cloud became well broken. The wind
veering WSW to W'ly during the afternoon and increasing F5-6. 0950 UTC an aircraft
reported the 1000 foot wind as 220° at 42 kt. Visibility 15 km to 25 km at first, falling
to 10 km in haze during the afternoon, improving to 20 km in the evening. Another mild
day.
- Rain, moderate at times overnight, the wind backing SSW'ly F4 by 0600 UTC. Rain,
moderate at times, continued during the morning with the visibility generally 15 km, but
falling to 2500 m in moderate or heavy rain and drizzle during the morning. Precipitation
turning lighter and intermittent after midday, the wind veering WSW'ly and increasing gale
from 1245 UTC with gusts to 53 kt. Mainly light patchy drizzle during the afternoon and
evening with the visibility around 10 km to 15 km. Becoming very mild during the evening.
- WSW'ly gale veering W'ly overnight and increasing severe gale F9 with gusts to 70 kt.
Veering WNW'ly late morning, increasing storm F10 during the afternoon with frequent gusts
in the range 70 kt to 80 kt, and to 85 kt at 1745 UTC. Becoming colder overnight with
frequent showers turning wintry during the morning with small hail, rain and snow and snow
leaving some snow/ice deposits on the ground at times in the afternoon. Storm moderating
gale to severe gale during the evening. Visibility generally poor at around 1500 m to 06
km in showers and spray.
- NW gale overnight, easing during the morning. Turning colder with temperatures falling
from 4° Celsius overnight to 1° Celsius by evening with frequent and sometimes heavy
wintry showers leaving a <50% deposit by that time. NW'ly winds F7 to gale F8 easing
F6-7 and backing NW'W late evening. Visibility generally 10 km to 15 km but falling to
1500 m in the showers and to 800 m in a moderate snow showers 1332 - 1340 UTC.
- F6 NW'W'ly winds easing NW'ly F3 for a time by 0600 UTC but soon increasing F5-6. A cold
day with temperatures generally around freezing. Further snow and hail showers, moderate
at times with the 10 km to 20 km visibility falling to <1000 m, giving 2 cm of lying
snow by 0900 UTC. Some drifting of the lying snow in the F4-6 NW'ly wind.
- Frequent snow, and small hail showers, some moderate, with drifting in the F6 to gale F8
NW'ly wind, veering NW to N'ly and easing F4-5 during the afternoon. A cold day with
temperatures generally around -1° Celsius and a high wind-chill in a wind gusting to 55
kt. Visibility generally 10 km to 20 km, but falling to <1000 m in moderate
precipitation and blowing snow. Visibility at 0830 UTC only 80 m in a moderate snow shower
and heavy blowing snow. Drifts to 20 cm to 25 cm, with some areas swept almost clear of
snow.
- Moderate aurora glow early hours. Frequent moderate or heavy snow showers overnight
increased the snow depth to 6 cm by 0900 UTC and to 8 cm by the end of the day. Another
cold day with temperatures around -1° to -2° Celsius and a F5-6 N'ly wind. Frequent snow
showers, heavy with blowing snow reducing visibility to less than 100 m at times. Most of
the snow showers began with a brief fall of snow pellets - soon turning to moderate snow.
A few drifts to 100 cm.
- Further frequent snow showers with heavy drifting snow in a F6 to gale F8 N to NW'ly
wind made snow depth measurement impossible and reduced the 10 km to 15 km visibility to
<100 m. Drifts to 50 cm to 100 cm. Thunderstorm with heavy snow and blowing snow
(visibility <50 m) 1140 UTC to 1200 UTC with gust to 57 kt. The Davis WM II recorded a
gust of 64 kt.
- With the N'ly winds easing F4-5 and less frequent snow showers and reduced drifting
snow, snow depths around the station were measured. 26 sample depths, varying from <1
cm to 84 cm, resulted in an estimated snow depth of 16 cm. The wind, N'ly F5-6 at first
eased F4 overnight, backing NW'ly during the day and easing F3 by evening and calm by
midnight. Visibility was generally 25 km to 40 km, falling to 08 km in showers.
- S'ly winds freshened F2-3 overnight with rain preceded by snow. Winds then veered SSW'ly
and, with further showery rain, a rapid thaw of lying snow ensued. Temperatures rising to
around 5° or 6° Celsius by midday. A bright afternoon with local heating producing
cumiliform stratus and some drizzly showers, the wind veering SW to WSW'ly. Visibility 20
km to 30 km.
- Well broken cloud overnight, the wind backing S'ly and increasing F4-5. Stratocumulus
cloud rapidly spreading in after 0700 UTC with rain and drizzle from 0830 UTC. A
continuing rapid thaw with snow cover <50% by noon. Precipitation, moderate at times,
continued until about 1330 UTC. At 1430 UTC a clearance could be seen to the SW and soon
after the wind veered W'ly and eased F3. The cloud then dispersed rapidly to give a fine,
clear evening.
- A few scattered rain showers overnight, otherwise a fine dry day. The wind, backing
SSW'ly overnight, increased F4-5 in the morning, F5-6 in the afternoon and F6-7 in the
evening. High cloud, becoming extensive during the morning, thickened to medium level
cloud through the afternoon, but this thinned to cirrus late evening. Visibility 20 km to
25 km.
- Rain, moderate at times overnight, the F7 SSW'ly wind veering SW'ly after 0445 UTC. Rain
ceased at 0630 UTC, the wind veering WSW'ly to WNW'ly at 0645 UTC. The cloud then breaking
with showers subsequently developing. Showers and variable amounts of cloud during the
afternoon, becoming frequent, moderate and wintry with small hail from 1805 UTC.
Visibility good at 20 km, but falling to 4000 m in the earlier rain.
- Overnight rain replacing earlier showers, the F5-6 WSW'ly wind increasing F7 by 0600 UTC
and gale F8 by 0830 UTC. Frequent gusts 50 kt to 56 kt around the middle of the day. A
mild, cloudy day with prolonged outbreaks of rain, or rain and drizzle, and extensive low
stratus. Visibility generally poor at 1500 m to 06 km. Thaw complete. Mild at first but
turning colder as the WSW'ly gale F8 wind veered WNW'ly during the evening. Rain and
drizzle cleared to squally showers early evening with a thunderstorm - frequent lightning
flashes - 2040 UTC to 2100 UTC. Heavy snow showers late evening as the temperature fell
close to freezing. WNW'ly winds easing F4 by midnight.
- Snow showers, becoming frequent and heavy - reducing the visibility to 300 m at times -
during the morning quickly increased the 1 cm snow depth to 9 cm by 1200 UTC. Winds, NW'ly
F3-5 at first, increased F6 to gale F8 during the afternoon and, with the temperature
falling as low as -3.8° Celsius, heavy drift ensued - often reducing visibility to
<100 m at times in blizzard-like conditions. By 1800 UTC with drifts to 130 cm, snow
depth measurement was impossible. During the evening NW'ly winds eased F7.
- Further snow showers, frequent and moderate at times with drifting snow. Drifts up to
150 cm around the station, and to 200 cm locally. F7 winds, between NW and NNW'ly, eased
F4-6 during the afternoon and F2-3 through the evening. Visibility 15 km to 20 km out of
snow, but falling to 100 m in heavy snow showers and blowing snow in the morning and to
<1000 m in moderate snow and small hail showers in the afternoon.
- Cold overnight with the wind backing S'ly and increasing F5. Dry, light snow from 0515
UTC, turning wet after 0600 UTC and to rain and snow 0700 UTC. Precipitation then soon
turning to rain, becoming moderate at times. The moderate rain resulted in a rapid thaw of
the lying snow. Visibility poor to moderate with fog 1000 to 1055 UTC in extensive low
stratus. The wind, veering SW'ly during the morning, veered WSW'ly just before midday.
Drier for a time during the afternoon, the wind backing SSW'ly and easing F4 with further
moderate rain in the evening, the wind increasing F6.
- Mild overnight with further rain and drizzle, moderate at times and a f5 SSW'ly wind.
Bright and dry by 0600 UTC, the visibility improving from 5000 m to 20 km as the wind
veered W'ly and increased F5-6. Well broken cloud during the morning with well scattered
showers. Turning colder during the afternoon with blustery showers of small hail, rain and
snow developing as the W'ly wind backs WSW'ly and increases gale F8 at times. Visibility
falling to 06 km in showers.
- F6 -7 W'ly wind and squally wintry showers, moderate at times with rain, rain and snow,
snow and small hail. Lightning seen early hours with thunderstorms 1541 UTC to 1600 UTC
and 2325 UTC to 2340 UTC. Visibility 15 km to 20 km, falling to 800 m in moderate snow and
small hail shower 1700 UTC. W'ly wind, backing SW'ly and easing F3-4 for a time during the
evening, increased F6 at 2315 UTC.
- F5-6 SW'ly wind overnight with further wintry showers of rain and snow and small hail. A
cold day with snow showers, moderate at times and reducing the visibility from 5000 m to
20 km down to 500 m at times, resulting in a <0.5 cm snow cover by 1800 UTC. Wind
veering W F5 during the morning and NW'W through the afternoon.
- Squally wintry showers overnight, the wind gusting to 64 kt at 0308 - with the Davis
WMII logging a gust of 72 kt at 0310 UTC (5 min mean 33 kt). At the same time the
temperature fell from 3.2° to 2.2° Celsius (Davis WMII). A cold day with further wintry
showers and a 1 cm snow depth at 0900 UTC thawing during the day. Wind NW'ly F6-7,
increasing gale F8 2045 - 2125 UTC. Visibility 10 km to 15 km but falling at times in the
wintry showers. A moderate shower of solid precipitation 1330 - 1335 UTC in the form of
snow pellets clumped together into balls approximately 8 mm in diameter.
- Wintry showers of rain and snow overnight with a F6-7 NW'ly wind. Showers dying out
during the day, the NW'ly wind easing F3-4 by late afternoon and veering N'ly during the
evening. A cold day, the temperature falling from around 3° Celsius at first, to 1°
Celsius mid afternoon with the ground beginning to freeze with the arrival of drier air.
Persistent contrail aligned E/W moving south during the afternoon. 1640 UTC aircraft
reports cloud tops at 6000 feet.
- A dry, cloudy night with a F2-3 N'ly wind falling calm or light variable by 0600 UTC. A
S to SSW'ly wind picking up during the afternoon. Becoming milder during the evening as
S'ly winds increase F4-5. Light rain and snow from 2220 UTC, turning to rain and drizzle
by midnight - the 30 km to 50 km visibility falling to 15 km.
- Cloudy overnight with moderate rain or rain and drizzle with extensive low stratus
during the morning. Visibility falling to 800 m for a time around 0700 UTC. Precipitation
becoming lighter and intermittent during the morning, with the visibility improving to 20
km for a time as the stratus base lifted. A further spell of moderate rain or rain and
drizzle during the afternoon. A much milder day, the temperature rising from 3° Celsius
at midnight to 8° Celsius by evening, though turning colder later as F4-6 SSW'ly winds
veered WSW'ly and increased F6-7 with the rain cleared to showers.
- Scattered showers overnight with a F5-6 WSW'ly wind. Becoming brighter during the
morning with broken cloud and scattered light rain showers - the wind backing SSW'ly and
increasing F6-7. A dry afternoon with well broken cloud and a F5-6 S to SSW'ly wind.
Visibility 20 km to 30 km.
- Dry for much of the day, apart from one light shower of rain and small hail 1803 - 1810
UTC, with well broken cloud, 30 km to 40 km visibility and a F5-6 S to SSW'ly wind.
- Wintry showers of rain and snow and small hail overnight with a F6-7 SSW'ly wind. As
indicated by the Davis WMII at 0300 UTC there was a pressure fall from 980.2 mb to 979.3
mb followed by a recovery. The temperature falling from 3.3° to 1.9° Celsius rose to
2.8° Celsius at 0300 UTC, falling to 2.1° at 0303 UTC followed by a rise soon after to
3.5° Celsius. At 0255 UTC the wind eased to a mean of 12 kt, veering 220° to 250° with
a sudden rise at 0303 back to a mean of 23 kt and a backing from 250° to 210°. Further
rain and snow showers during the day, the F5-6 SSW'ly wind veering WSW'ly during the
afternoon. Visibility 20 km to 40 km, falling to 2000 m at times in showers.
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