DATASTREME DAILY SUMMARY
Friday, 13 October 2000
- A WARMING TREND ACROSS THE EAST
- A WESTERN COOL SPELL
- TEMPERATURE EXTREMES ACROSS THE CONTINENTAL US
- ALASKAN WEATHER
- HAWAIIAN WEATHER
- A WINTER FORECAST
- THE HUNTER'S MOON
- HISTORICAL WEATHER EVENTS
A WARMING TREND ACROSS THE EAST -- Much of the country
east of the Mississippi experienced a pleasant October day courtesy
of a large high pressure system centered over West Virginia as
of Thursday evening. Following a relatively chilly night where
numerous record low temperatures were set across the Southeast,
temperatures rebounded quickly under sunny skies. Afternoon high
temperatures across the eastern half of the nation were either
at or above the average high temperatures for this time of year.
The largest anomalies (differences between the observed and average
highs) were found in the western Great Lakes, where temperatures
were 15 degrees above the climatological average highs. This
high pressure was the same high pressure that earlier in the week
spread abnormally cold air across the region. The warming was
a result of air mass modification and warm-air advection. The
cold air mass had been modified as it moved across previously
warmed ground and as a result of the relatively cloud-free skies
that permitted solar heating. A southerly wind regime across
the Mississippi Valley associated with the clockwise circulation
around the western flank of the high pressure cell was responsible
for the warm-air advection, or transport of warm Gulf air northward.
In addition to the warm-air advection across the Upper Midwest,
the southerly winds also provided moisture advection as evident
by the increase in clouds across the region by Thursday afternoon.
As of late Thursday night, some light precipitation was also
detected by radar across the Upper Mississippi Valley.
The high pressure cell should continue to dominate the weather
across the East and Southeast as the center of the high is forecast
to drift southward to the western mountains of North Carolina
by Friday evening. A slow weakening of the central pressure is
also anticipated, diminishing from an impressive 1044 mb reading
last Sunday to a forecasted 1025 mb. Another chilly night is
expected because of the enhanced radiational cooling.
A WESTERN COOL SPELL -- A large pool of cold air has become
entrenched across the Western States, accompanied by clouds and
precipitation. Afternoon temperatures across the West were below
average, with the greatest anomalies being found across the northern
Rockies, where Thursday's highs were between 10 and 15 degrees
below the long-term average highs. Widespread clouds and precipitation
were found in a counterclockwise swirl around several low pressure
centers located in western Montana and northern Idaho. Great Falls,
MT received 0.65 inches of rain, which was a record rainfall total
for the date. Several inches of snow had fallen at Yellowstone
Park in northwest Wyoming as of Thursday evening.
The eastern periphery of the cold air was a cold front that was
moving slowly eastward. This cold front trailed across the Plains
and the southern Rockies from a weak low pressure center over
South Dakota. Some precipitation was found near the low pressure
center and farther south along the front over New Mexico.
On Friday the cold front is expected to continue moving eastward
across the Plains, with the northern portion of the front and associated
low pressure system reaching the Upper Mississippi Valley by evening.
Widespread light precipitation could fall across the region.
Some thunderstorms are possible across the central Plains, but
none should become severe. The precipitation across the northern
Rockies and Intermountain West is expected to gradually dissipate.
However, snow advisories were in effect for far western Wyoming
and the Wasatch Mountains of Utah and southeast Idaho where 6
to 12 inches of snow could fall at elevations above 7000 feet.
The total amount of liquid equivalent precipitation falling across
the Plains and the Rockies between Friday and Saturday mornings
is expected to be relatively light, ranging between 0.25 and 0.50
inches.
TEMPERATURE EXTREMES ACROSS THE CONTINENTAL US -- Thursday's
lowest temperature was 18 degrees at Grand Canyon, AZ. Thursday's
highest temperature was 88 degrees at Mineral Wells, TX.
ALASKAN WEATHER -- Cloud-free skies were found across much
of Alaska as the result of a ridge of high pressure located over
northwest Canada. The only exception was the cloudy skies over
the southeast and the extreme west. The clouds in the southeast were
produced by a storm system located in the vicinity of Prince William
Sound with an associated front that stretched along the Gulf coast
into the Panhandle, along with a stationary front that stretched
from the Alaska Peninsula into the southern Yukon Territory.
These systems were also responsible for precipitation across the
southeast. Rain was found along the southeast Panhandle, to include
Sitka and Yakutat. Snow fell across the southeast mainland, such
as at Northway and McCarthy.
Clouds across the west were the result of a warm front that extended
southeastward across the Bering Sea from a strong storm system
over eastern Siberia. In addition, a tight pressure gradient
that developed between the Canadian high pressure system and the
Siberia storm system produced strong winds especially across the
Northwest. Point Hope reported sustained winds of almost 40 mph,
with gusts to over 50 mph. Whittier also had peak gusts to 40
mph.
The lowest overnight temperature in Alaska on Thursday morning
was one degree below zero at Deadhorse, while the mid-afternoon
highest statewide temperature was 61 degrees at Petersburg and
Wrangell.
HAWAIIAN WEATHER -- A tight pressure gradient developed
across the islands on Thursday as the result of a subtropical
ridge located to the north of Hawaii and a weak tropical disturbance
passing to the south. This steep pressure gradient produced moderate
to brisk trade winds that reached 25 mph. The passing disturbance
also helped enhance the trade showers over the windward slopes
of the Big Island. Because of the winds, small craft advisories
remained in effect for state waters.
A WINTER FORECAST -- On Thursday meteorologists and climatologists
at the National Oceanic and Atmospheric Administration (NOAA)
released their initial winter outlook or forecast for the nation.
Their press release
indicates that following several abnormally warm winters, the
upcoming winter (November, December and January) should be more
"normal" since the anomalous atmospheric and oceanic
circulation patterns identified as La Niña and El Niño
appear to have waned.
THE HUNTER'S MOON -- A full moon occurred early this morning
(more precisely, at 0853 Z on 13 October or 4:53 AM EDT, 3:53
AM CDT, etc.). This full moon is often called the "Hunter's
Moon" since it follows the more spectacular "Harvest
Moon" (this year on 13 September). Because of geometrical
considerations, this full moon is not as impressive as its predecessor
in terms of the string of long moonlit nights when the moon rises
near sunset. The Hunter Moon may have been named because the moonlight
may have assisted hunters in their autumnal hunt.
HISTORICAL WEATHER EVENTS - 13 October
From the files of the Aviation Weather Center, Kansas City,
MO and Intellicast
- ...1846...The "Great Hurricane of 1846" tracked
across Cuba, Florida, Georgia, the Carolinas, Virginia and Pennsylvania.
The hurricane inflicted major damage along its entire path, which
was similar to the path of Hurricane Hazel 108 years later. The
hurricane caused great damage at Key West, FL, and at Philadelphia,
PA it was the most destructive storm in thirty years. (David Ludlum)
(The Weather Channel)
- ...1986...Four tornadoes struck southeastern Virginia late
in the night causing three million dollars damage. Tornadoes at
Falls Church, VA caused a million dollars damage. (Sandra and
TI Richard Sanders)
A cold wave set many record lows across the western U.S. including
13 degrees at North Platte, NE. (Intellicast)
- ...1987...Fifteen cities in the eastern U.S. reported record
low temperatures for the date. Record lows included 34 degrees
at Meridian, MS, 28 degrees at Paducah, KY, and 26 degrees at
Beckley, WV. Another surge of arctic air entered the north central
U.S. bringing snow to parts of Wyoming and Colorado. (The National
Weather Summary)
- ...1988...A total of forty-three cities in the eastern U.S.
and the Upper Midwest reported record low temperatures for the
date, including Elkins, WV and Marquette, MI where the mercury
dipped to 18 degrees. (The National Weather Summary)
- ...1989...Sixteen cities reported record high temperatures
for the date as readings warmed into the 80s and low 90s from
the Southern and Central Plains to the Southern and Middle Atlantic
Coast. Evansville, IN and North Platte, NE reported record highs
of 91 degrees. (The National Weather Summary)
- ...1994...A slow moving low pressure dumped 14.26 inches of
rain in 24 hours at Hunter, GA. (Intellicast)
14 October
- ...1909...A tornado (F3 on the Fujita intensity scale) struck
Stantonville and Pittsburg Landing, TN. Twenty three were killed
and 80 injured. (Intellicast)
- ...1957...Floodwaters roared through a migrant labor camp
near the town of Picacho, AZ flooding fifty cabins and a dozen
nearby homes. 250 migrant workers lost their shelters. The month
was one of the wettest Octobers in Arizona weather history. (The
Weather Channel)
- ...1965...Heavy rains hit the coastal areas of southeastern
Florida. In a 24 hour period rains of twenty inches were reported
from Deerfield Beach to Fort Lauderdale, with 25.28 inches on
the Fort Lauderdale Bahia-Mar Yacht Basin. Flooding that resulted
caused considerable damage to roads and streets. The rains inundated
numerous newly planted vegetable fields, and some residences.
Ten miles away just 4.51 inches of rain was reported. (14th- 15th)
(David Ludlum) (The Weather Channel)
- ...1966...A late season tornado outbreak hit North Central
Iowa. Twelve tornadoes touched down with the most devastating,
an F4 tornado, which demolished a large section of Belmond with
6 killed, 172 injured and $12 million damages. (Intellicast)
- ...1981...Four days of heavy rain across northern Texas and
southern Oklahoma came to an end. The heaviest rains fell in a
band from southwest of Abilene, TX to McAlester, OK, with up to
26 inches reported north of Gainesville, in north central Texas.
The heavy rains were the result of decaying Hurricane Norma, which
also spawned thirteen tornadoes across the region. Seven deaths
were attributed to the flooding. (Storm Data)
- ...1984...Dense fog contributed to a 118 vehicle accident
on I-94, just south of Milwaukee, WI. It was the seventh day of
an eight day stretch of dense fog. At the time of the accident
the visibility was reportedly close to zero. (Storm Data)
- ...1987...Sixteen cities, mostly in the Appalachian Region,
reported record low temperatures for the date. Record lows included
43 degrees at Lake Charles, LA, 35 degrees at Augusta, GA, and
27 degrees at Asheville, NC. Gale force winds buffeted the Carolina
coast. Light snow fell across parts of Wyoming, Colorado, and
western South Dakota. (The National Weather Summary)
- ...1988...Forty cities in the eastern U.S. reported record
low temperatures for the date. Elkins, WV was the cold spot in
the nation with a record low of 18 degrees above zero. Thunderstorms
in Arizona drenched Phoenix with nine inches of rain in nine hours,
the fifth highest total for any given day in ninety-two years
of records. Carefree, AZ was soaked with two inches of rain. (The
National Weather Summary)
- ...1989...Thunderstorms produced severe weather over Michigan
during the morning, and over New York State and Connecticut during
the afternoon and evening hours. Thunderstorms spawned two tornadoes,
and there were ninety reports of large hail or damaging winds,
including seventy reports of damaging winds in New York State.
A tornado at McDonough, NY killed one person and injured three
other people. Strong thunderstorm winds gusted to 105 mph at Somerset.
Temperatures warmed into the 80s and lower 90s over much of the
nation east of the Rockies, with eleven cities reporting record
high temperatures for the date. Afternoon highs of 81 degrees
at Beckley, WV and Bluefield, WV equaled October records. (Storm
Data) (The National Weather Summary)
15 October
- ...1876...Snow fell in the rear of a coastal storm from Virginia
to New England. New York City had its earliest 32 degree temperature
and 1/2 inch of snow. Fall River, MA had 3.5 inches of snow.
(Intellicast)
- ...1880...A violent early season blizzard raked Iowa, Minnesota
and the Dakotas. Northwest Iowa received 7 inches of snow. Winds
gusted to 70 mph at Yankton, SD, and snow drifts 10 to 15 feet
high were reported in northwest Iowa and southeast South Dakota.
Saint Paul, MN reported a barometric pressure of 28.65 inches
on the 16th. Railroads were blocked by drifts of snow which remained
throughout the severe winter to follow. Gales did extensive damage
to ships on the Great Lakes. (15th-16th) (David Ludlum) (The Weather
Channel)
- ...1947...A hurricane made a hairpin turn off the Georgia
coast after being seeded with dry ice. The storm moved over Savannah
and into Georgia. (Intellicast)
- ...1954...Hurricane Hazel struck the Carolina coastline near
Cape Fear, NC. The hurricane (a category 4 storm on the Saffir-Simpson
Scale) demolished every pier along a 170 mile stretch from Myrtle
Beach, SC to Cedar Island, NC, and obliterated entire lines of
beach homes. At Long Beach, 300 homes vanished, no debris remained.
Hurricane Hazel also destroyed 1500 homes as it moved inland with
seventeen foot tides. Winds between Myrtle Beach, SC and Cape
Fear, NC gusted to 150 mph. As the storm came inland it quickly
transformed into a powerful extratropical storm and raced north
northwestward though the mid-Atlantic states. Washington, DC had
a record sustained wind of 78 mph with gusts to 98 mph. Hurricane
Hazel caused 163 million dollars damage, and claimed the lives
of 98 persons. (David Ludlum) (The Weather Channel)
- ...1965...Fort Lauderdale, FL was deluged with 25.28 inches
of rain in a 48 hour period causing considerable road and street
damage and inundating numerous recently planted vegetable fields
and homes. (Intellicast)
- ...1987...Unseasonably cold weather continued in the eastern
U.S., with thirteen cities reporting record low temperatures for
the date. The low of 34 degrees at Montgomery, AL was their coldest
reading of record for so early in the season. Lows of 32 degrees
at Harrisburg, PA and 34 degrees at Parkersburg, WV marked their
third straight morning of record cold. (The National Weather Summary)
- ...1988...The cold high pressure system responsible for the
record low temperatures in the eastern U.S. began to move out
to sea, giving way to a trend toward "Indian Summer".
Thunderstorms developing ahead of a cold front produced golf ball
size hail at Altamont, KS and hail two inches in diameter at Yates
City, IL. (Storm Data) (The National Weather Summary)
- ...1989...Hurricane Jerry made landfall at Galveston, TX at
6:30 PM (CDT), on one of the latest dates for a storm in this
region. Winds at the Galveston Airport reached 75 mph, with gusts
to 100 mph. Tides along the island were six to eight feet, and
rainfall totals ranged up to slightly more than six inches north
of Beaumont. Three persons were killed when their vehicle was
blown off the Galveston seawall into the pounding surf. Total
damage along the Upper Texas Coast was estimated at fifteen million
dollars. Thunderstorms produced severe weather in Lower Michigan
during the late morning. Two persons were injured when a tree
fell on their camper at the Traverse City State Park. While strong
northerly winds ushered much colder air into the central U.S.,
unseasonably warm weather continued in the south central and eastern
U.S. The afternoon high of 82 degrees at Bluefield, WV was a record
for October. (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.