MORE LAKE EFFECT -- Lake-effect and lake-enhanced snow continued to fall downwind of the Great Lakes on Wednesday. Buffalo, NY had received nearly a foot of new snow, bringing much of the city to a virtual halt. Winds shifting from northwest to southwest resulted in the heavy snowfall in Buffalo, as these winds have the greatest possible fetch across Lake Erie. As of late Wednesday night, a weak low pressure area was located over Lake Huron. This low had intensified as it had moved southeastward from Manitoba and passed over the western Lakes. This intensification was the result of the instability produced as cold air moved over a relatively warm water surface. Lake-enhanced snow continued in the favored snowbelt regions of Michigan, northern Indiana, northeast Ohio and western New York State. A cold front trailing the surface low produced some light snow across southern Wisconsin.
On Thursday, the low pressure that had intensified over the Lakes was expected to move to the northeast, entering the St. Lawrence Valley by morning. Snow is expected to continue, especially across the eastern Lakes. Consequently, lake-effect snow warnings were in effect through Thursday for downwind regions of Lower Michigan near Benton Harbor (where 6 to 10 inches of new snow were expected), northeast Ohio near Ashtabula (3 to 6 inches of new snow), northwest Pennsylvania around Erie and New York State in the Buffalo metropolitan area (where some areas could receive 6 to 12 more inches of snow by morning) and to the east of Lake Ontario, including Watertown, NY.
AN ALBERTA CLIPPER -- A storm system that developed in the lee of the Canadian Rockies in northern Alberta earlier on Wednesday was moving southeastward across the Prairie Provinces. As of Wednesday evening, the low pressure center was located in southern Saskatchewan, with a warm front that extended southeastward across the Dakotas into northwest Missouri. This type of storm system is often called an "Alberta Clipper" for the region where the low formed and the rapid movement of this low. Light snow was falling over the Dakotas and western Minnesota, ahead of the warm front. Some freezing rain and ice pellets were reported along the front, while rain fell in the relatively warm air to the west of the front. Temperature contrasts across the warm front were impressive, with single digits above zero found to the east of the front, but mid 30s to the west. A southwest, downslope wind -- a Chinook wind -- helped warm the air behind the front. Rapid City, SD had a high of 61 degrees on Wednesday afternoon, after recording 25 degrees the day before.
The Alberta Clipper is expected to continue its southeastward movement, reaching the eastern Dakotas by morning and southern Lake Michigan by evening. Snow associated with this system is expected to spread across the Dakotas, Minnesota and Wisconsin. A variety of snow and winter weather advisories were posted for the Red River Valley to include western Minnesota and the eastern Dakotas. Winds between 15 and 25 mph along with higher gusts could produce blowing snow, reducing visibility. Between 2 to 4 inches of snow are expected across portions of Minnesota and western Wisconsin. To the south, a freezing rain advisory was in effect across southwest Minnesota.
CONTINUED COLD WEATHER ACROSS THE SOUTH -- Unseasonably cold weather continued across the South on Wednesday as a cold high pressure system remained across the region. On Wednesday morning, Tallahassee, FL had a record low temperature of 24 degrees. Freeze warnings were posted for Wednesday night and Thursday morning across central Texas and along the lower Rio Grande Valley.
IT DOES RAIN IN SOUTHERN CALIFORNIA - A weakening low pressure system off the coast of southern California was responsible for producing clouds and rain across southern California from the Los Angeles Basin northward to the San Francisco Bay area on Wednesday evening. Rain is expected to continue across the region through Thursday, with as much as 0.25 inches possibly falling in some locations.
A record high temperature was established at Shelter Cove, CA with 80 degrees.
LINGERING FOG -- While most of the fog that persisted in the valleys of California had dissipated by Wednesday night, some valleys did experience foggy conditions. In particular, a dense fog advisory remained in effect for the Magic Valley of Idaho.
SOMEONE'S COUNTING -- As another arctic air mass appears poised to spread across the West by the weekend, the National Weather Service Office at Rapid City, SD reported that the last time Rapid City had a subzero reading was on 4 January 1999, or 701 days ago, which is a record number of consecutive days that the temperature remained above zero.
UPPER AIR -- The mid and upper tropospheric charts for 00Z Thursday exhibit a meridional flow pattern, with a height ridge in the West and a trough across the eastern Great Lakes. The trough reflects the pool of cold air located over the region. Jet stream winds at 300 mb reached 130 knots over the Upper Mississippi Valley.
YESTERDAY'S TEMPERATURE EXTREMES ACROSS THE LOWER 48 -- Wednesday morning's lowest temperature was 11 degrees below zero at Eagle River and Rhinelander, WI and Cambridge, MN, while the Wednesday afternoon highest temperature was 81 degrees at Glendale and Northridge, CA.
ALASKAN WEATHER -- A large storm system over the western Bering Sea dominated the weather across much of western Alaska on Wednesday afternoon. An occluded front associated with this storm system curved first northeastward and then southward across the Yukon-Kuskokwim delta and Bristol Bay and the Alaska Peninsula. Winds gusted to 50 mph across the Aleutians. In addition, rain fell along the island chain. A weak ridge of high pressure extended from the eastern Gulf of Alaska into south central Alaska. An onshore flow contributed to rain across the Panhandle. The North Slope experienced strong winds with speeds reaching 45 mph, which produced low wind-chill equivalent temperatures, along with blowing snow.
Snow also fell across northern and interior Alaska.
The lowest temperature in Alaska on Wednesday morning was 8 degrees below zero at Umiat. The highest statewide temperature as of Wednesday afternoon was 46 degrees at Chignik, Hydaburg, Ketchikan and Klawock.
HAWAIIAN WEATHER -- The Aloha State experienced continued pleasant trade weather on Wednesday as a weak ridge of high pressure was situated to the north of the islands. Light to moderate east-northeast winds along with relatively cloud-free skies were the result. High surf advisories were continued for the northwest facing shores of the islands. However, the ocean swell that was generated by a storm well to the northwest should decrease on Thursday.
A YEAR IN REVIEW -- The National Weather Service (Office of Meteorology) has prepared a national map depicting the Significant Weather Events of 2000 (updated through 22 November 2000). Similar maps are also available from the previous several years.
This week concludes the fall 2000 edition of the DataStreme course. The purpose of the DataStreme Project is teacher enhancement, providing you with the opportunity to learn some meteorological principles that you can use not only in your classroom, but as a Weather Education Resource Teacher. The experiences that you have gained in the weather sciences as well as in accessing the Internet should now allow you to expand your horizons to work with other teachers.
On the Wednesday, Week 12 activity, you were introduced to the DataStreme Junction Homepage. DataStreme Junction is intended as a site where course alumni can go beyond information available via the now-familiar DataStreme Homepage and the DataStreme course materials. The term "Junction" is used because the new homepage will be a connecting point to other weather-related sources on the Internet. You are encouraged to visit DataStreme Junction from time to time as you proceed as a DataStreme Weather Education Resource Teacher.
You should add the DataStreme Junction Homepage to your browser's "Bookmark" or "Favorite Places" list so you can easily reach it when you are on-line.
The familiar DataStreme Homepage will continuously deliver current meteorological data throughout the year, including the summer. The DataStreme Daily Summary will contain only the selected Historical Weather Events for each day from this coming Monday through mid January, when Daily Summaries and other DataStreme course materials will return to the Homepage during Preview Week on Monday, 22 January 2001 for Spring 2000 course participants. Hopefully, you will frequently visit to read the Daily Weather Summary and the fresh activity materials prepared each Monday and Wednesday during future course offerings.
For a behind-the-scenes view at how the daily weather summary is built, please read the Thursday optional Supplemental Information.
To be submitted on the lines for Thursday on the Study Guide, Part B, Applications', Week 12 Chapter Progress Response Form, under section B. Daily Summary.
From the files of the Aviation Weather Center, Kansas City, MO and Intellicast
Return to DataStreme Homepage
URL Address: datastreme/learn/r_sum.html
Prepared by Edward J. Hopkins, Ph.D., email hopkins@meteor.wisc.edu
© Copyright, 2000, The American Meteorological Society.