DATASTREME DAILY SUMMARY

Friday, 9 November 2001


00Z Weather Systems


TAKE A MOMENT - Since Sunday is Veteran's Day, formerly called Armistice Day, take a moment to remember this country's veterans, especially those who never made it home.

The following highlights of the national weather have been extracted from the surface weather map for Thursday night:

WINTRY WEATHER MOVES ACROSS NORTHERN NEW ENGLAND -- A storm system moving across the Northeast was spreading some snow across northern Maine on Thursday night. The storm consisted of a low pressure center located along the St. Lawrence River just to the north of Upstate New York. A warm front extended southeastward across New England, while a cold front trailed southwestward across the eastern Lakes, the Ohio Valley and into the southern Plains. Snow was falling in the cold air to the north of the surface low pressure center and warm front from Maine into Quebec and New Brunswick, while rain was found farther south along the cold front across southern New England, New York State and Pennsylvania.

The storm system is expected to continue moving northeastward along the St. Lawrence Valley, reaching the Gulf of St. Lawrence by Friday evening. A winter weather advisory was posted for northwest Maine until daybreak Friday as 3 to 6 inches of snow are anticipated.

While wintry weather was found in the cold air to the north of the low pressure system, relatively mild conditions were found to the south of the low pressure center. High temperatures on Thursday were on the order of 15 degrees above the long-term average highs across the eastern Lakes and the Ohio Valley as a result of the southwesterly wind flow across the region in advance of the cold front.

HIGH PRESSURE ACROSS SOUTHEAST PRESENTS PROBLEMS -- Much of the Eastern Seaboard continues to be dominated by a large ridge of high pressure that extends off the coast into the western North Atlantic Ocean. While the presence of this high has produced a long string of pleasant weather in many locales, the lack of significant rain in several months has become a serious problem. Many of the states along the Eastern Seaboard extending from the Carolinas northward to Maine have experienced increased wildfire dangers. Major wildfires have been burning in South Carolina near Myrtle Beach and in Kentucky and neighboring West Virginia.

RAIN ACROSS THE SOUTHERN PLAINS -- Rainshowers and isolated thunderstorms were found along the southern and western portions of the cold front that trailed southwestward from the low pressure center near New England. Most of the precipitation was found across Oklahoma, western Arkansas and north Texas.

As the cold front drifts southward to the Rio Grande Valley more rain is expected across Texas. As much as 0.4 inches are anticipated across South Texas from Friday to Saturday morning. A dense fog advisory was posted along the Texas Gulf Coast in the vicinity of Houston late Thursday night as the humid Gulf air cooled to the dewpoint.

Chilly weather spread southward behind the southward advancing cold front. Snow fell on Wednesday and early Thursday across the higher terrain of Colorado. High temperatures on Thursday across the southern Rockies and adjacent Plains to the east were on the order of 10 degrees below the average highs for the date.

WINDY WEATHER ACROSS THE NORTHERN ROCKIES -- A relatively tight pressure gradient between high pressure situated over the Rockies and the Great Basin and lower pressure over the Prairie Provinces produced a strong westerly wind flow across the northern Rockies. A high wind warning was in effect for northern Rocky Mountain Front in northwest Montana near Glacier National Park as winds were expected to reach 45 mph with gusts to 65 mph. The westerly downslope winds were also responsible for producing relatively mild conditions across the northern Plains where high temperatures were 10 to 15 degrees above average. The downslope winds warmed as a result of compressional heating.

WESTERN RECORDS -- With relatively dry air associated with a large high pressure system located across the Intermountain West, temperatures tend to fall rapidly during the night. As a result, a record low temperature was established on Thursday morning at Wenatchee, WA (24 degrees). Fog was also a problem in the Columbia Basin as air cooled to saturation. A dense fog advisory was posted on Thursday night through Friday morning for the Columbia Basin as fog was expected once again.

The presence of the high pressure cell to the east meant that western Oregon had an easterly wind flow. As a result, coastal communities were did not experience the cooling effects of winds from off the Pacific Ocean. Brookings, OR reached a record high temperature of 76 degrees.

UPPER AIR -- An increased amplitude in the upper level wind flow became apparent on the 500 and 300 mb charts for 00Z Friday. A trough in the height contours developed across the Great Lakes while a more distinct ridge formed across the West. As a result, the jet stream at 300 mb contained westerly winds over the Pacific Northwest, then becoming more northwesterly across the Plains and then finally turning into westerly and southwesterly winds across the East.

TEMPERATURE EXTREMES ACROSS THE CONTINENTAL US -- Thursday's lowest temperature was 9 degrees at Stanley, ID and at Wolf Point and Butte, MT. Thursday's highest temperature was 90 degrees at Riverside, CA and Gila Bend, AZ.

ALASKAN WEATHER -- An arctic air mass remained anchored over much of Alaska on Thursday. This air mass was associated with a large high pressure center located over the Arctic Ocean. Subzero temperatures were found across interior Alaska at midday. A stationary front marking the southern limit of this air mass extended from north of Cold Bay in the eastern Bering Sea and Bristol Bay eastward along the north Gulf Coast to southern Yukon Territory and across northern British Columbia. While the North Slope and northwest Alaska had cloudy skies, interior and portions of south central Alaska had relatively few clouds. Snow was reported at Deadhorse and Nuiqsut on the Arctic coast. To the south of the stationary front, several low pressure systems affected the Gulf of Alaska. One system that moved from the eastern Gulf of Alaska into western Canada helped bring heavy snow across the northern Panhandle, to include a foot of new snow near Yakutat. Snow continued to fall at Yakutat, in the Anchorage Bowl and in the Haines-Skagway area, while rain was reported across the Panhandle south of Lynn Canal. Another low pressure center was located in the western Gulf south of the Alaska Peninsula. This low along with an elongated storm system over the south central Bering Sea produced strong winds and rain across the Alaska Peninsula and the Bering Sea. Rain was reported at Cold Bay.

The lowest overnight temperature in Alaska on Thursday morning was 24 degrees below zero at Fort Yukon, Galena, Paxson and Slana, while the mid-afternoon highest statewide temperature was 48 degrees at Annette.

HAWAIIAN WEATHER -- Gusty trade winds continued from the east to northeast across the islands at speeds ranging between 10 to 25 mph. High pressure was located to the northwest of the islands. High clouds remained across the Aloha State on Thursday. Afternoon showers and isolated thunderstorms developed over the slopes of the Big Island as convection developed during the afternoon solar heating.

By afternoon surf along the north shore of Oahu was reported in the 15 to 25 foot range with occasional sets to 30 feet. This surf originated from a strong storm system off the Kamchatka Peninsula at the start of the week. As a result, high surf advisories were posted for the northwest facing shores of all the islands.

PUTTING A WRAP ON OCTOBER -- The National Climatic Data Center (NCDC) has produced a list of various noteworthy extremes in snowfall across the United States during the recently concluded month of October at http://lwf.ncdc.noaa.gov/oa/climate/extremes/2001/october/octoberext2001.html. Updates to this list to include extremes in temperature and precipitation may appear later.

A SOMBER ANNIVERSARY -- Tomorrow is the 26th anniversary of the sinking of the Great Lakes ore carrier, Edmund Fitzgerald, during a powerful storm on Lake Superior. Last year the National Weather Service Forecast Office at Marquette, MI created a web page commemorating the sinking and describing the advances in marine weather forecasting over the last quarter century.


HISTORICAL WEATHER EVENTS - 9 November

From the files of the Aviation Weather Center, Kansas City, MO and Intellicast

10 November

11 November


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URL Address: datastreme/learn/f_sum.html
Prepared by Edward J. Hopkins, Ph.D., email hopkins@meteor.wisc.edu
© Copyright, 2001, The American Meteorological Society.