DATASTREME DAILY SUMMARY

Monday, 4 September 2000


WELCOME TO DATASTREME - This Daily Summary represents one of the products that you will routinely use in the DataStreme Project. We - to include myself and those at DataStreme Central - would like to welcome all the participants to this exciting project. I will be responsible for producing this Daily Summary File that describes current and recent weather features of note. On Tuesdays and Thursdays, this file will also contain a "Concept of the Day", which will develop some weather topic in further detail. Two questions related to that topic will appear at the end of this feature for you to answer as part of the weekly materials that you will submit to your LIT mentor by fax. On occasion, I will post a Supplemental Information File. As its name indicates, this file will contain supplementary background material or resource information.
Sincerely,
Ed Hopkins

00Z Weather Systems


HAPPY LABOR DAY!

The following highlights of the national weather have been extracted from the surface weather map for late Sunday night.

AN EXTENDED FRONT -- A nearly stationary front extended from the New England coast westward across the southern Great Lakes, the Plains, the northern Rockies to the Great Basin. This front separated warm and muggy air found across the Southern States from cooler and slightly drier air located across the Northern Plains.

Several weak areas of low pressure were found along this front. Several clusters of rainshowers and thunderstorms moved eastward along the frontal boundary. As of late Sunday night, one cluster of thunderstorms was moving across Indiana, while another group of thunderstorms were moving across eastern portions of Nebraska and South Dakota. Some of these thunderstorms were strong and could become severe.

THE HEAT GOES ON -- To the south of the frontal zone, a large dome of hot air remained entrenched over the southern Plains. This dome of hot air located over Texas extends upward through the atmosphere to heights of several thousand feet. While the surface weather maps indicate weak low pressure across the region, the clockwise circulation of the clouds around a large area of relatively clear skies indicates a deep high pressure system in the lower atmosphere. The weak low pressure areas indicated on the map reflect the relatively warm, buoyant air that has remained over the region for an extended length of time.

Once again afternoon temperatures reached the triple digits across the southern Plains on Sunday afternoon. Numerous daily record high temperatures were set from Texas northward into Kansas and eastward into Arkansas and western Tennessee. Some of these highs either tied or set monthly record high temperatures for the month of September to include in Texas at Dallas-Ft. Worth (109 degrees), Tyler (109 degrees), College Station (109 degrees), Waco (108 degrees), Austin-Mabry (108 degrees), Austin-Bergstrom (107 degrees), Del Rio (106 degrees), San Antonio (104 degrees) and Galveston (99 degrees) in Arkansas at El Dorado (110 degrees) and Ft. Smith (109 degrees) and in Louisiana at Shreveport (109 degrees), Alexandria (107 degrees), Baton Rouge (103 degrees), Lafayette (103 degrees) and Lake Charles (103 degrees). The heat has been relentless, with several locations setting high minimum temperature records to include Dallas-Ft. Worth had a morning low of 80 degrees and Midland with 75 degrees on Sunday morning.

Dallas-Ft. Worth did not receive any rain on Sunday, extending its record streak of consecutive days without measurable precipitation (0.01 inch or greater) to 65 days.

COOL WEATHER ACROSS THE NORTHERN PLAINS -- To the north of the front cool Canadian air was found along the Canadian border. This cool air was associated with a high pressure system that was situated over northern Manitoba on Sunday night. The clockwise circulation around this high pressure meant that winds from the east and northeast were found from the western Great Lakes westward to the Dakotas. Sunday afternoon high temperatures across northern Minnesota remained in the mid and upper 50s.

The ridge of high pressure in northern Manitoba is expected to drift slowly southeastward, reaching the Lakes region in the central portion of the province by Monday morning. As a result of the southeastward migration of cooler air, the stationary front that was located over the western Great Lakes and Upper Mississippi Valley is anticipated to begin moving southward as a cold front. This cold front is forecasted to reach the Ohio and Mid-Mississippi Valleys by Monday morning, resulting in cooler and less humid weather across the Great Lakes States.

WET WEATHER CONTINUES ACROSS THE EAST -- Numerous rainshowers and thunderstorms continued across the Middle Atlantic States southward into the Southeast on Sunday. These showers were associated with a weak region of low pressure located across the Middle Atlantic States. The frequent lightning accompanying these thunderstorms forced a delay in the New York Giants-Arizona Cardinal NFL football game at the Meadowlands in northern New Jersey.

The rain is expected to continue across the region through Monday, with as much as an inch of rain possible along the Carolina and Virginia coasts. Because these rains continue to fall on ground saturated by recent rains, flash flood watches were in effect across the Del-Mar-Va Peninsula, much of southern Virginia and North Carolina.

COOL WEATHER MOVES INTO THE NORTHWEST -- Cool, cloudy weather moved into the Pacific Northwest on Sunday. Some welcome precipitation also fell across the region, extending from western Washington eastward to the northern Montana and southward to southern Idaho and northern California. Some light snow fell over the Cascades at elevations of above 6000 feet. The cooler weather and the precipitation, albeit light, was welcomed by the firefighters who continued to battle the massive wildfires that have been raging across the West.

On Sunday morning, record low temperatures were set across the Pacific Northwest at Yakima, WA (35 degrees) and Pendleton, OR (41 degrees). Record low temperatures were set in California in the San Francisco Bay area at Oakland (49 degrees) and Moffett Naval Air Station (49 degrees) and in the Los Angeles Basin at Chatsworth (51 degrees) and Pasadena (50 degrees). Afternoon high temperatures on Sunday remained in the 60s across portions of the Northwest.

On Monday the region of precipitation is forecast to spread eastward across Montana into the western Dakotas.

ROCK AND ROLL -- An earthquake with a magnitude 5.2 on the Richter Scale near Napa, CA awakened residents north of San Francisco Bay early Sunday morning. Some minor damage was sustained and utilities disrupted. Several injuries were reported.

TEMPERATURE EXTREMES ACROSS THE LOWER 48 -- On Sunday, the lowest temperature reported in the continental U.S. was 28 degrees at Elko, NV and McCall, ID, while Sunday's highest temperature was 111 degrees at Ardmore, OK.

ALASKAN WEATHER -- Many areas of the state experienced cloudy skies on Sunday. However, sunny skies were found across the Panhandle and south central Alaska. An area of low pressure was developing over the North Pacific and Gulf of Alaska on Sunday afternoon. A warm front associated with this system extended eastward toward the central Panhandle, while a cold front extended southwestward to another low pressure center located several hundred miles south of Cold Bay. In the Arctic, a deep low pressure system was located several hundred miles west of Wrangell Island. High pressure was developing over the North Pacific south of Adak Island in the Aleutians.

The lowest overnight temperature in Alaska as of Sunday was 30 degrees at Anaktuvuk Pass, Eagle and Gustavus, and the midafternoon highest statewide temperature was 66 degrees at Ketchikan.

HAWAIIAN WEATHER -- Clouds spread northeastward across Kauai and Oahu on Sunday as an area of disturbed tropical weather was located near Johnston Atoll, several hundred miles to the southwest of the islands. However, few showers were associated with these clouds. The winds across the islands were from the east in association with the large area of high pressure that was located roughly 1000 miles to the north-northeast of Hilo. On Monday and Tuesday clouds and showers associated with the remnants of former Tropical Storms John and Kristy are expected to move westward across the Eastern Pacific and could affect the Big Island.

EYE ON THE TROPICS -- On early Saturday an area of low pressure in the tropical Atlantic had intensified with near surface winds that exceeded 39 mph. At this point, this system was named Tropical Storm Ernesto, the fifth named tropical cyclone (low pressure system) of the year in the North Atlantic Basin. By late Sunday afternoon Ernesto was located some 300 miles to the east northeast of the Leeward Islands. At that time since near-surface winds had dropped to 35 mph and no organized circulation was found around the system, Ernesto was downgraded to a tropical wave.

REPORT FROM THE FIELD -- Rena Faye Norby, a DataStreme participant from Belle Fourche and Spearfish in the Black Hills of South Dakota reported last Friday that smoke from the Western wildfires hung in the air for the last week. She said that they had some rain, but more was needed to help revive the crops that have suffered from this summer's heat.

AN INVITE -- If you witness some interesting weather phenomena or would like to share some weather-related experience with others in the DataStreme Project, we cordially invite your contributions. Please email these to the address appearing below. Some of these may appear in the section titled "Reports from the Field"


HISTORICAL WEATHER EVENTS - 4 September

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


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Prepared by Edward J. Hopkins, Ph.D., email hopkins@meteor.wisc.edu
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