DATASTREME DAILY SUMMARY
Friday, 15 December 2000
- GETTING OFF EASY
- AN INTERLUDE
- MORE WINTRY WEATHER AHEAD FOR THE MIDWEST
- SNOW ACROSS THE NORTHWEST
- UPPER AIR
- YESTERDAY'S TEMPERATURE EXTREMES IN THE LOWER 48
- ALASKAN WEATHER
- HAWAIIAN WEATHER
- A TIME OUT
- HISTORICAL WEATHER EVENTS
GETTING OFF EASY -- The storm system that produced the
icing conditions across the Southern Plains on Wednesday quickly
moved across the Northeast on Thursday, causing less weather related
problems than initially anticipated. The widespread icing that
was anticipated across the Middle Atlantic States did not materialize
because the near surface air in many locations was too warm, with
rain falling rather than freezing rain. However, the icing was
scattered, with approximately 0.5 inches of ice accumulated on
surfaces in portions of Maryland. Some locations across interior
New York State and New England did receive 4 to 8 inches of snow.
By Thursday night the low pressure system was located in the Gulf
of Maine. Some light snow was falling across northern Maine.
By Friday morning the low should have moved to the northeast
of the Maritime Provinces, resulting in the end of the snow in
New England.
AN INTERLUDE -- High pressure located over the Ohio Valley
on Thursday night was responsible for tranquil weather across
much of the eastern half of the nation. This high pressure follows
on the heels of two winter storm systems that moved across the
country during the first part of the week -- one that produced
heavy snows across the Midwest, and the second, the above mentioned
system. High temperatures for many locations were 10 to 15 degrees
below the average highs for this time of the year.
The high pressure system is expected to drift to the east, reaching
western Maryland by Friday morning, and New England by dusk.
With weak winds and clear skies under the high pressure system,
radiational cooling should cause temperatures to fall to the dewpoint,
producing fog. Dense fog advisories were issued for portions
of Georgia and the western Carolinas. The Northeast should experience
quiet, but cool weather on Friday. For the nation's midsection,
the tranquil weather of Thursday will be short-lived, since the
next series of storms are expected to arrive.
MORE WINTRY WEATHER AHEAD FOR THE MIDWEST -- A weak low
pressure system is expected to develop over the lee slopes of
the Colorado Rockies on Friday morning and move across the central
Plains toward the Midwest by late in the day. Moisture drawn
northward into this low pressure system is expected to fall as
snow across the upper Mississippi Valley into the western Great
Lakes by Friday night. Farther to the south, freezing rain is
expected across the mid-Mississippi Valley as warm moist air
is drawn northward over the shallow cold dome of air. Consequently,
winter storm watches were posted for portions of southwestern
Wisconsin, northwest Illinois, eastern Iowa and southeastern Minnesota.
In anticipation for the powerful storm moving across the northern
Plains from the Pacific Northwest, winter storm watches have been
posted effective Friday night and Saturday for northwest Wisconsin,
northern Minnesota and eastern North Dakota.
SNOW ACROSS THE NORTHWEST -- A storm system moved into
the Pacific Northwest on Thursday spreading precipitation eastward
into the interior. The low pressure center was located over Vancouver
Island, with an occluded front that trailed southward along the
Washington and Oregon coasts. Rain fell along the coast, while
snow was falling across the Cascades and the mountains of eastern
Washington, Oregon, northern Idaho and northwest Montana.
This system is expected to move eastward, crossing the Canadian
Rockies by Friday morning. Between 12 to 18 inches of snow are
expected in the Washington and Oregon Cascades, as cold air should
cause the snow level to fall to approximately 2000 feet. A variety
of winter storm warnings, snow advisories and winter weather advisories
cover much of the Northwest, from the Olympic Peninsula of Washington
State east to the Montana Rockies and south to northern Colorado.
In addition to the snow, this storm is expected to generate strong
winds with gusts ranging between 55 to 70 mph as the system crosses
the Rockies. High wind warnings were posted for the Columbia Basin
of Washington and Oregon, the mountains in eastern Idaho, the
upper Yellowstone Valley of southern Montana and the mountains
of southeastern Wyoming. Farther south, wind advisories were
also posted in the Sierras for 30 to 40 mph winds.
UPPER AIR --The 500 and 300 mb constant pressure charts
for 00Z Friday revealed a relatively zonal (west to east) flow
with a small trough over the Intermountain West.
YESTERDAY'S TEMPERATURE EXTREMES IN THE LOWER 48 -- The
lowest temperature on Thursday was 24 degrees below zero at Cambridge,
MN, while the day's high was 86 degrees at Fort Myers and Punta
Gorda, FL.
ALASKAN WEATHER -- The main players in Alaska's weather
for the last several days-- high pressure over the Yukon Territory
and low pressure over the Bering Sea -- remained relatively stationary
on Thursday. The pressure gradient between these two weather
features continued to generate gusty southeasterly winds to a
large portion of the state. Cold Bay had winds of 54 mph, while
Golovin had 46 mph winds. Early Thursday morning 62 mph winds
were recorded at Douglas, across the Channel from Juneau and 107
mph gusts were reported at Sheep Mountain, 3500 feet above Juneau.
As a result of the southerly flow, above average temperatures
were found across northwest Alaska, while below average temperatures
were concentrated in the southeast. Much of Alaska was relatively
cloud-free, except for the clouds along the Bering Sea, the southern
portion of the Alaska Peninsula and the northern Gulf coast.
Snow fell at Yakutat, while Sand Point and Seward reported rain.
The lowest overnight temperature across the state as of Thursday
was 34 degrees below zero at Northway. The highest midafternoon
temperature was 45 degrees at Chignik.
HAWAIIAN WEATHER -- The subtropical ridge of high pressure
that maintained the trade winds over the Aloha State shifted toward
the east away from the islands. As a result, winds across the
islands weakened and shifted to a more southeasterly direction
on Thursday. Clouds and isolated showers formed over the interiors
of the islands during the afternoon. Normal east to northeast
trade winds are expected to return on Friday as another high pressure
cell passes to the north of the islands.
Strong winds off Japan produced ocean swells that propagated across
the Pacific toward Hawaii. The ocean swells is expected to generate
surf that could reach 10 feet on the north shore of Oahu by Friday
morning. As a result, high surf advisories were posted for the
northwest shores of the islands.
A TIME OUT -- Today's Daily Weather Summary discussion
is the final one for the fall 2000 course. If you are looking
for an alternative description of daily weather, you could try:
http://www.usatoday.com/weather/wlead.htm
DataStreme Daily Summaries and Activity files will return with
the Spring 2001 DataStreme course during Preview Week on Monday,
22 January 2001. Have a happy and safe holiday season! EJH
Several noteworthy events that will occur during the next several
weeks include:
- HAPPY WINTER SOLSTICE! The winter solstice will occur
on Thursday morning, 21 December 2000 (at 1337Z, or 9:37 AM EST,
8:37 AM CST, etc.) as the earth's spin axis will be oriented such
that the sun appears to be the farthest south in the local sky
of most earth-bound observers. While most of us consider this
to be the start of astronomical winter, the British call today
the "Midwinter Day", as the apparent sun will begin
its northward climb again. For essentially all locations in the
northern hemisphere, Wednesday night will be the longest and the
daylight on Thursday will be the shortest of the year. Starting
Friday the length of darkness will begin to shrink as we head
toward the summer solstice on 21 June 2001 at 0738Z.
- A CHRISTMAS ECLIPSE -- With a new moon passing between
the earth and sun, a partial solar eclipse should be seen across
most of North America. The eclipse is forecast to begin at 1527Z
(10:27 AM EST), reach the midpoint of the eclipse at 1735Z (12:31
PM EST) and end at 1943Z. At maximum eclipse, the moon will appear
to cover approximately 40% of the solar disk for residents of
the Southeast, while residents in the northern Great Lakes should
have approximately 60% of the disk covered. Caution! Do not
look directly at the sun nor use a telescope. Follow recommended
safe viewing procedures.
- IN CLOSE -- Earth reaches perihelion, the point in
its orbit that is closest to the sun (147.1 million kilometers
or 91.2 million miles), on Thursday, 4 January 2001 at 09 Z (4
AM EST, 3 AM CST, etc.).
- RECORD KEEPING -- Contrary to popular option, this
upcoming New Year's marks the start of a new millennium, century
or a decade -- at least in terms of maintaining weather records.
Additionally, the standard 30 year climatological interval for
1971-2000 will be concluded on 31 December 2000. Regardless, Happy
New Year!
HISTORICAL WEATHER EVENTS - 15 December
From the files of the Aviation Weather Center, Kansas City,
MO and Intellicast
- ...1839...The first of triple storms hit Massachusetts Bay.
The storm produced whole gales, and more than 20 inches of snow
in interior New England. There was great loss of life at Gloucester,
MA. (David Ludlum)
- ...1901...An intense cold front swept across the eastern U.S.
The cold front produced heavy rain in Louisiana, and heavy snow
in the northeastern U.S. (David Ludlum)
- ...1945...A record December snowstorm buried Buffalo, NY under
36.6 inches of snow, with unofficial totals south of the city
ranging up to 70 inches. Travel was brought to a halt by the storm.
(14th-17th) (The Weather Channel)
- ...1987...A major winter storm hit the Great Lakes Region,
intensifying explosively as it crossed northern Illinois. High
winds and heavy snow created blizzard conditions in southeastern
Wisconsin. Winds gusted to 73 mph, and snowfall totals ranged
up to 17 inches at LaFarge. The barometric pressure at Chicago,
IL dropped three quarters of an inch in six hours to 28.96 inches,
a record low reading for December. Up to a foot of snow blanketed
northern Illinois, and winds in the Chicago area gusted to 75
mph. O'Hare Airport in Chicago was closed for several hours, for
only the fourth time in twenty years. High winds derailed train
cars at Avon, IN. Light winds and partly sunny skies were reported
near the center of the storm, a feature typical of tropical storms.
(The National Weather Summary) (Storm Data)
- ...1988...High pressure in the Pacific Northwest and low pressure
in the southwestern U.S. combined to produced high winds from
Utah to California. Winds gusting to 70 mph in the San Francisco
area left nearly 300,000 residents without electricity. Winds
in Utah gusted to 105 mph at Centerville. (The National Weather
Summary) (Storm Data)
- ...1989...A couple of low pressure systems spread heavy snow
across the northeastern U.S. Up to two feet of snow was reported
along Lake Erie in northeastern Ohio, and up to ten inches was
reported in Connecticut. Heavy snow squalls developed over Michigan
for the third day in a row. Three Oaks, MI reported 25 inches
of snow in two days. Twenty-six cities in the north central U.S.
reported record low temperatures for the date. The low of 10 degrees
below zero at Wichita, KS was a December record for that location.
(The National Weather Summary) (Storm Data)
- ...1991...Snow squalls unloaded on the Tug Hill plateau in
New York east of Lake Ontario. Totals of 44 inches fell at Highmarket
and 30 inches at Boonville. Snowfall rates reached 6 to 8 inches
per hour at Boonville. (Intellicast)
16 December
- ...1835...New England experienced one of their coldest days
of record. At noon on that bitterly cold Wednesday the mercury
stood at four degrees below at Boston, 15 degrees below at Norfolk,
CT, and 17 degrees below at Hanover, NH. The temperature at Boston
was 12 degrees below zero by sunset. Gale force winds accompanied
the severe cold, and that night a great New York City fire destroyed
much of the financial district. (David Ludlum)
- ...1890...A big snowstorm at Pittsburgh, PA dropped 23.9 inches
in 24 hours, the greatest 24 hour snow for that city. (Intellicast)
- ...1917...An ice jam closed the Ohio River between Warsaw,
KY and Rising Sun, IN. The thirty foot high ice jam held for 58
days, and backed up the river a distance of 100 miles. (David
Ludlum)
- ...1987...A Pacific storm battered the coast of California
with rain and high winds, and dumped heavy snow on the mountains
of California. Winds along the coast gusted to 70 mph at Point
Arguello, and winds in the Tehachapi Mountains of southern California
gusted to 100 mph at Wheeler Ridge. Snowfall totals ranged up
to 24 inches at Mammoth Mountain. Snow fell for two minutes at
Malibu Beach, and Disneyland was closed due to the weather for
only the second time in twenty-four years. A winter storm which
began in the Southern Rockies four days earlier finished its course
producing snow and high winds in New England. Snowfall totals
ranged up to 19 inches at Blanchard, ME. (The National Weather
Summary) (Storm Data)
- ...1988...Fairbanks, AK reported freezing rain and record
warm temperatures. The afternoon high of 41 degrees was 43 degrees
above normal. Snow and high winds continued to plague the mountains
of southern California. Mount Wilson, CA reported two inches of
rain in six hours during the early morning, and a storm total
of more than 3.50 inches of rain. (The National Weather Summary)
- ...1989...Fifty-seven cities from the Southern and Central
Plains to the Appalachians reported record low temperatures for
the date, including North Platte, NE with a reading of 17 degrees
below zero. Squalls in the Great Lakes Region produced 18 inches
of snow at Syracuse, NY, and 30 inches at Carlisle, IN. Low pressure
brought heavy snow to northern New England, with 18 inches reported
at Derby, VT and Saint Johnsbury, VT. Thunderstorms with heavy
snow were reported at Portland, ME. (The National Weather Summary)
(Storm Data)
17 December
- ...1884...A three week blockade of snow began at Portland,
OR. A record December total of 34 inches was received. (David
Ludlum)
- ...1924...A severe ice storm struck central Illinois. It coated
the ground with nearly two inches of glaze at Springfield. The
storm caused 21 million dollars damage along with much hardship.
Ice was on the trees until the 4th of January, and electricity
was not restored until January 10th. (David Ludlum)
- ...1929...An ice storm in western New York State resulted
in much damage and hardship. A Buffalo report stated, "one
was kept awake by the breaking limbs, which snapped off with a
report much louder than a rifle shot." (17th-18th) (The Weather
Channel)
- ...1930...Greensboro, NC experienced its greatest 24 hour
snowfall when 14.3 inches fell. (Intellicast)
- ...1964...An arctic outbreak made its way into the northwest
with a blizzard in Idaho, Washington and Oregon. Heavy snow also
fell in coastal sections. Walla Walla, WA had a temperature of
20 below zero for a new December low. (Intellicast)
- ...1987...A storm in the southwestern U.S. brought heavy rain
and heavy snow to parts of California, Nevada, Arizona, Utah and
New Mexico. Charleston, NV was blanketed with 12 inches of snow.
Lake Havasu City, AZ was drenched with 2.26 inches of rain. (Storm
Data) (The National Weather Summary)
- ...1988...Squalls brought locally heavy snow to the southeastern
shores of Lake Michigan. Totals in Michigan ranged up to 14 inches
at Harvey. Totals in Ohio ranged up to 16 inches at Chardon. (The
National Weather Summary) (Storm Data)
- ...1989...Twenty-one cities from Kentucky to Pennsylvania
reported record low temperatures for the date, including Columbus,
OH with a reading of 12 degrees below zero. Heavy snow continued
in the Colorado Rockies. Vail received 65 inches of snow between
the 14th and the 18th of December. Steamboat Springs was buried
under 74 inches, and reported a total of 108 inches of snow between
the 10th and the 18th of the month. (The National Weather Summary)
(Storm Data)
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URL Address: datastreme/learn/f_sum.html
Prepared by Edward J. Hopkins, Ph.D., email
hopkins@meteor.wisc.edu
© Copyright, 2000, The American Meteorological Society.