DATASTREME DAILY SUMMARY

Wednesday, 14 November 2001


00Z Weather Systems


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

THE NEXT SYSTEM REACHES THE COAST -- A widespread area of precipitation spread across Washington and Oregon in association with a front that was located along the coast of the Olympic Peninsula and Vancouver Island on Tuesday evening. This cold front trailed southward from a major storm system located in the Gulf of Alaska. Since the air surrounding this system was sufficiently warm, snow levels across the northwest were high and most of the precipitation was falling as rain. By Tuesday evening, several locations in western Washington and coastal Oregon had received more than 2 inches of rain within the last 12 hours.

The cold front is expected to move inland and then stall over portions of central Washington and western Oregon by Wednesday morning. Widespread heavy rains associated with this system are forecast to fall on the western slopes of the Olympics, Cascades and Coast Range. Anticipated 24 hour rainfall totals ending on Wednesday evening range from 1.0 to 4.5 inches across this region. Some rain in advance of a warm front that is expected to move toward the Washington coast on Wednesday evening could contribute to the rainfall totals. Because of the heavy rains that have fallen and the additional anticipated rains through Wednesday night, a flash flood watch has been posted for portions of western Washington through Thursday. A flood warning was in effect for at least one river on the Olympic Peninsula.

In addition to the heavy and widespread rains, the cold front moving onto the Olympic Peninsula was preceded by strong southerly winds. Cannon Beach, OR reported southerly winds that gusted to 65 mph on Tuesday afternoon. Gale warnings were continued for the Washington and Oregon coasts from Cape Flattery, WA to Point St. George, CA. A high wind warning was continued for the coastal headlands of Oregon through Wednesday night as south winds with gusts to 60 mph are expected to continue as another front approaches.

Farther east, a high wind warning was posted for the Rocky Mountain Front and adjacent Plains of northwestern Montana in the vicinity of Glacier National Park. Southwest winds with sustained speeds to 45 mph and gusts to 65 mph were anticipated as the pressure gradient between high pressure over the Great Basin and lower pressure over Alberta tightens.

UNSETTLED WEATHER ACROSS THE SOUTHWEST -- The storm system that brought record rains to central California on Monday moved eastward across the Great Basin and by Tuesday night it consisted of a weak area of low pressure in southern Colorado. Some widely scattered precipitation associated with this system was found across the Four Corners area of the Southwest. Earlier on Tuesday morning Cuyama, CA reported a record 24 hour rainfall total of 0.35 inches, while 4 to 8 inches of snow had fallen across the Sierras.

As this low pressure moves eastward and dissipates over the southern Rockies, a widespread area of rain and embedded thunderstorms is expected to develop over west Texas, New Mexico and southern Colorado. As much as one inch of rain could fall across the Texas Panhandle by Wednesday evening.

MILD WEATHER CONTINUES ACROSS THE NATION'S MIDSECTION -- With high pressure anchored off the Middle Atlantic coast, a broad flow of warm and humid air continued to be carried northward across the Mississippi Valley and the Plains on southerly winds. Above average high temperatures were reported at most locations from the Rockies to the Appalachians. The largest departures between the actual and average high temperatures were found across the northern Plains, where highs ranged between 20 to 30 degrees above the average highs for mid November. Grand Forks, ND reported a record high temperature of 60 degrees. Because of the influx of warm and humid air along with clouds and fog, nighttime temperatures remained elevated. Several stations in the Plains and the Upper Midwest tied or established new high minimum temperature records, to include Russell, KS (59 degrees), Grand Island, NE (57 degrees), Sioux City, IA (59 degrees) and in Minnesota at Minneapolis-St. Paul (50 degrees) and Duluth (44 degrees). The low at Sioux City was also the highest minimum during the month of November.

The continued flow of warm and moist air into the Plains also produced widespread fog on Tuesday night. Dense fog advisories were posted for western Iowa, southwest Minnesota, eastern Nebraska, southwest Nebraska and northwest Kansas.

A band of light rain was being carried across the Great Lakes on southwesterly winds.

ANOTHER CHILLY START IN THE NORTHEAST -- Relatively cool and dry air was found across New England and portions of the Middle Atlantic States in association with a large high pressure system that extended along the Eastern Seaboard. With clear skies and weak winds, record low temperatures were set on Tuesday morning at Windsor Locks, CT (18 degrees), Providence, RI (21 degrees) and Atlantic City, NJ (22 degrees).

WET WEATHER ACROSS THE SUNSHINE STATE -- Easterly winds on the southern flank of the high pressure cell continued to bring a large area of precipitation across the Florida Peninsula. The onshore winds also resulted in heavy surf along the Atlantic Coast. As a result, a heavy surf advisory was in effect from Flagler Beach, FL to South Santee River, SC.

UPPER AIR -- Both the 500 and 300 mb charts for 00Z Wednesday reveal that a height trough has moved across the Great Basin while the height ridge has moved over the Plains.

YESTERDAY'S TEMPERATURE EXTREMES ACROSS THE CONTINENTAL US -- Tuesday morning's lowest temperature was 5 degrees at Saranac Lake, NY, while the highest temperature on Tuesday was 86 degrees at Harlingen and McAllen, TX.

ALASKAN WEATHER -- Arctic air remained across much of mainland Alaska. The southern boundary of this air mass was a stationary front that ran northeastward along the Alaska Peninsula and the southern slopes of the Alaska Range to the Anchorage Bowl and then eastward along the Gulf Coast to northwest British Columbia. A weak area of low pressure was located along the kink in this front near Anchorage. Farther south, a large storm system continued to move slowly to the southeast across the Gulf of Alaska. Rain and snow were found across southeast Alaska and the Panhandle. The low pressure center, with a central pressure of approximately 968 mb, was located to the west of the Queen Charlotte Islands. With high pressure continuing to build across the western Bering Sea, a tight pressure gradient remained across the Bering Sea and western Alaska. King Salmon, Sand Point and Dutch Harbor experienced wind gusts to 40 mph. A high wind warning was in effect for the Aleutians west of Adak through Tuesday night. Wind gusts at Shemya reached 62 mph, but were expected to reach 75 mph there and at other locations before diminishing to 45 mph by Wednesday afternoon. A low pressure system developed along the Arctic coast to the northwest of Barrow. Light snow was reported at Kotzebue, Bettles, Fairbanks, Fort Wainwright and Healy.

The state's lowest overnight temperature on Tuesday morning was 22 degrees below zero at Snowshoe Lake. The highest temperature by mid afternoon of Tuesday was 48 degrees at Klawock and Metlakatla.

HAWAIIAN WEATHER -- The ridge of high pressure responsible for the trade winds across the islands has drifted south toward the Aloha State, reaching a location approximately 300 miles north of Kauai by Tuesday evening. The showers that had been found across Oahu and Kauai finally dissipated. The ridge is expected to continue to approach the islands. As a result, the trades should continue to weaken and by Wednesday speeds should range between 5 to 15 mph. Northerly swell is expected to arrive on Wednesday and generate surf along the north shores of the islands with heights of 15 feet by Thursday.

TRACKING THE STORMS: HANDS-ON EXERCISE -- Learn how to track storm systems as well as high pressure systems in Wednesday's optional Supplemental Information.


HISTORICAL WEATHER EVENTS - 14 November

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


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