WELCOME TO DATASTREME - The Daily Summary file will describe the current weather pattern across the U.S. The Tuesday and Thursday files will also contain the "Concept of the Day" with a question to be answered on the weekly Chapter Response Form. Additional Supplemental Information Files will provide optional background material.
WET WEATHER CONTINUES ALONG THE GULF -- A stationary front that stretched from the Mississippi Delta eastward along the Gulf Coast to cross the northern Florida peninsula continued to be the focal point for widespread rain. Thunderstorms were found to the south of the front in the warm and humid air, while to the north, a more steady rain and drizzle was reported. Except for those locations where excessive precipitation rates produced a rapid runoff, most of the rain was welcomed since this region remains in a prolonged drought.
By Friday morning the stationary front is expected to dissipate. However, widely scattered rainshowers and thunderstorms should continue across the Florida Peninsula and over Louisiana.
Space Shuttle Atlantis was struck by lightning on Thursday as it sat on the launch pad at Cape Kennedy Space Center waiting for a tentative Friday morning launch. Thunderstorm activity may force a postponement of the liftoff.
Aided by the clouds along the stationary front, relatively cool weather was found across Louisiana. While abnormally warm conditions continued across neighboring Texas, afternoon highs at Monroe (75 degrees) and Lake Charles (78 degrees) were record low maximum temperatures. Interestingly, three days previously, Lake Charles experienced an afternoon high temperature of 105 degrees.
PLEASANT WEATHER ACROSS THE NORTHEAST -- A large ridge of high pressure extended from off Cape Cod in eastern Massachusetts southwestward into the Middle Atlantic States. As a result, pleasant weather was found across much of the Northeast. With clear skies and light winds -- conditions typical of locations near the center of high pressure -- nighttime cooling caused the temperature at Allentown, PA to fall to a record-tying low of 43 degrees.
High pressure should remain over the Middle Atlantic through Friday.
A CHANGE IN THE WINDS -- A cold front moving eastward into the western Great Lakes produced a change in the winds and a slightly cooler and drier air mass. This cold front extended from a low pressure center near James Bay southward along the length of Lake Michigan and across the mid-Mississippi Valley before turning into a stationary front over the central Plains. Winds ahead (to the east) of the advancing front were from the southwest, circulating in a clockwise fashion around the high pressure cell located in the Middle Atlantic States. These southwesterly winds (following the meteorological convention of naming the winds for the direction from where the winds originate) were carrying warmer and more humid air northward. Behind the front, a weak high pressure cell located over the Missouri Valley produced a more westerly or northerly wind flow. Slightly cooler and drier conditions were found across the Upper Mississippi Valley.
Most of the precipitation that had been associated with the front earlier in the day had dissipated by the time the front moved across the Mississippi River, the result of a lack of sufficient moisture supply. As of late Thursday night, some light rainshowers were found across southern Wisconsin and in northern portions of Lower Michigan.
By Friday morning the northern portion of the cold front is anticipated to have moved across Lake Huron, while the southern and western portions of the front could linger over southern Lake Michigan. Some precipitation could fall along the front in the form of scattered rainshowers and thunderstorms. By Friday afternoon the western portion of the front is expected to start moving northward as a warm front across the Mississippi Valley.
THE HEAT CONTINUES IN THE SOUTHWEST -- While the widespread region of excessive heat and triple-digit temperatures has subsided across much of the Southern Plains, the heat continues across the Southwest, from west Texas westward into Arizona. Record high temperatures were recorded on Thursday afternoon in west Texas at El Paso (100 degrees) and Lubbock (98 degrees) and in Arizona at Tucson (105 degrees) and Douglas (100 degrees).
RAIN IN SOUTHERN CALIFORNIA -- Widely scattered rainshowers and some embedded thunderstorms spread northward across southern California on Thursday in association with the low pressure area located in the Southwest. Most of the rain accumulations were relatively light.
UNSETTLED WEATHER IN THE PACIFIC NORTHWEST -- A cold front swept into the Pacific Northwest, accompanied by clouds and precipitation. This cold front trailed from a low pressure system in Central British Columbia across western Washington State and northwestern Oregon. Most of the precipitation associated with this front was confined to the Puget Sound area of western Washington, where the onshore winds behind the front ran into the Cascades.
The cold front is expected to continue eastward, crossing the mountains of northwest Montana by Friday morning. Areas of rain associated with this system should be found along the windward slopes of the mountain ranges.
Elsewhere in the West, Elko, NV, near the center of high pressure, tied its record low temperature on Thursday morning with a 26 degree reading.
TEMPERATURE EXTREMES ACROSS THE CONTINENTAL US -- Thursday's lowest temperature was 23 degrees at Big Piney and Jackson, WY. Thursday's highest temperature was 111 degrees at Coolidge, AZ.
ALASKAN WEATHER -- Clouds remained across much of Alaska on Thursday. Several low pressure systems were responsible for the widespread clouds and areas of precipitation. One low was located over British Columbia near Alaska's Panhandle. Light rain associated with this system was found across the Panhandle and interior Alaska. Another low pressure system was located near the Aleutians. As a result, the Aleutian and Pribilof Islands experienced rain, fog and gusty winds. Cold Bay and St. Paul had gusts to roughly 30 mph.
The lowest overnight temperature in Alaska on Thursday morning was 27 degrees at Arctic Village, while the mid-afternoon highest statewide temperature was 61 degrees at Elmendorf AFB, Merrill Field and Big Lake.
HAWAIIAN WEATHER -- Showers and occasional thunderstorms developed over the slopes of the volcanic peaks on the Big Island and near the Haleakala summit on Maui. These showers and thunderstorms developed as the result of the combination of low level moisture and a vertical temperature distribution that permits air to easily move upward during the afternoon heating of the earth's surface. The subtropical high pressure system responsible for the trade winds found across Hawaii moved westward to a position roughly 1500 miles north of Hilo. As a result, these prevailing winds from the east increased to speeds ranging from 15 to 25 mph. These winds will help maintain trade showers on the windward slopes of the islands. These showers could also be enhanced by the moisture associated with the remnants of Tropical Storm Kristy that is expected to pass south of the islands.
EYE ON THE TROPICS -- In the eastern North Pacific Tropical Storm Lane was downgraded to a tropical depression as winds dropped below the 39 mph minimum for tropical storms. As of Thursday evening Tropical Depression Lane, with near-surface winds of approximately 35 mph, was nearly stationary some 550 miles west southwest of Acapulco, Mexico.
A SOLEMN CENTENNIAL -- The National Oceanic and Atmospheric Administration (NOAA) just issued a press release commemorating the Galveston, TX hurricane of 1900. This release contains links to historic photos and a excerpts of an eye-witness description of storm by the chief forecaster of the Galveston U.S. Weather Bureau Office.
From the files of the Aviation Weather Center, Kansas City, MO and Intellicast
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Prepared by Edward J. Hopkins, Ph.D., email
hopkins@meteor.wisc.edu
© Copyright, 2000, The American Meteorological Society.