WEATHER OVER THE WEEKEND -- The high pressure center that had dominated last week's weather remained across the Southeast over the weekend. However, continued airmass modification meant that the diurnal temperature range between high and low temperatures began to diminish. Several overnight low temperatures were either tied or set on Friday morning across the Southeast as a result of the weak winds and relatively cloud-free skies near the high pressure center. These daily low records included Asheville, NC (31 degrees), Mrytle Beach, SC (42 degrees) and Savannah, GA (43 degrees). However, the increased humidification of the air mass meant that the nighttime temperatures did not fall to record lows during the balance of the weekend. In addition, daytime temperatures continued an upward trend at least across the Middle Atlantic states and the New England states. By Saturday, several record high temperatures were set across the Northeast, to include Windsor Locks, CT (81 degrees), Blue Hill Observatory at Milton, MA (79 degrees) and Portland, ME (78 degrees). By Sunday, a "back door cold front" - so named because it moves toward the southwest in a direction counter to what is normally experienced in midlatitude -- moved across the New England states and caused the temperatures to fall from Saturday's record levels. The front traveled to the south of Boston, MA. Even on Sunday, afternoon high temperatures across the Middle Atlantic were 10 degrees above the long-term average highs for mid October.
An active cold front moved slowly eastward across the nation over the weekend. On Friday this cold front stretched from the Arrowhead of Minnesota southwestward to west Texas. Some active thunderstorms developed along and ahead of the cold front. On Friday evening two tornadoes that were reported by storm spotters caused some damage in north central Iowa, while nearby, high winds reaching 64 mph were observed at Storm Lake, IA. Some damage was reported elsewhere in Iowa as well as in south central Kansas. Hail with diameters up to 1.00 inch were also reported across Iowa and Kansas. By Saturday, the cold front had shown little eastward movement, stretching from northern Wisconsin to west Texas. Severe thunderstorms produced large hail (diameters as large as 1.75 inches) and damaging winds (speeds measured as high as 70 mph) across northern Missouri, northeast Kansas and the Texas Panhandle. By Sunday morning the northern portion of the front had reached Michigan's Lower Peninsula, while the southern portion of the front had essentially become a stationary front over eastern New Mexico. Thunderstorms produced large hail on Sunday near Gage in western Oklahoma and in southeastern New Mexico near Carlsbad.
Behind the front, precipitation fell across the northern Rockies, with as much as 6 inches of snow falling near Yellowstone Park, WY on Friday. Missoula, MT had a record-setting 0.49 inches of precipitation on Friday.
WEATHER FOR THE START OF THE NEW WEEK -- The following highlights of the national weather have been extracted from the surface weather map for late Sunday night.
An east-west oriented stationary front that extended from the New York City metropolitan area westward into the southern Great Lakes provided the focus for precipitation across the Lakes and Middle Atlantic States. The eastern portion of this front was the "backdoor cold front" that had moved southward across New England earlier in the day. The stationary front separated relatively warm high pressure across the Southeast from the colder high pressure across eastern Canada. The heaviest precipitation associated with this front was from near Chicago across southern Lower Michigan into western New York State.
Just to the south of this stationary front, a weak low pressure center was situated over central Ohio, with a cold front that trailed westward over the Ohio River before becoming a stationary front over the central Plains. The stationary front extended to the west-southwest across the Texas Panhandle. The main area of precipitation associated with the front was found across the southern Plains, stretching from south Texas northward to southern Kansas and from western Arkansas westward to west Texas. As of late Sunday night, some locations across southern Oklahoma and north Texas had accumulated more than three inches of rain. Some relatively small areas of light rain were also detected across the Ohio Valley closer to the low pressure center.
The low pressure center over Ohio is expected to move eastward into western Pennsylvania on Monday along with its associated fronts. As much as 0.5 inches of rain could fall on Monday across New York State and southern New England. Farther west along the frontal boundary, a weak low pressure system is forecast to develop across Oklahoma by Monday morning and move eastward on Monday. Between 0.5 and 1.5 inches of rain could fall from the southern Plains, across the Ozarks of southern Missouri and into the Ohio Valley.
Relatively quiet weather extended across the northern Plains from the Upper Mississippi Valley to the Great Basin in association with high pressure. A weak trough is expected to intensify across the western Dakotas and move eastward on Monday. By Monday evening, the precipitation area should have reached the Upper Mississippi River Valley.
A storm, located approximately 200 miles west of the Washington coast on Sunday evening, was expected to move closer to the coast by Monday evening. As a result, several inches of precipitation are forecast to fall during the 24 hours commencing on Monday morning over the Pacific Northwest, especially across the Olympic Peninsula and the northern Cascades. Gale warnings were posted for the Washington coast from Cape Flattery to Cape Shoalwater.
TEMPERATURE EXTREMES ACROSS THE LOWER 48 -- On Sunday, the lowest temperature reported in the continental U.S. was 12 degrees at Alamosa, CO, while Sunday's highest temperature was 94 degrees at Junction, TX.
ALASKAN WEATHER -- Much of Alaska was either cloudy or foggy on Sunday afternoon. However, some breaks in the overcast were found across the interior. A nearly stationary low pressure system was located over the Gulf of Alaska to the southeast of Kodiak Island, while an east-west running stationary front stretched across the state from St. Lawrence Island and the Seward Peninsula to the Alcan border. A tight pressure gradient between high pressure over the western North Pacific and the low pressure center in the Gulf generated gusty winds across the Aleutians, the Alaska Peninsula and into the Bering Sea. Dutch Harbor and Cold Bay reported wind gusts in excess of 40 mph on Sunday. Strong winds were also reported at St. Lawrence Island and at Point Hope. The onshore flow associated with the Gulf low resulted in heavy rain at Ketchikan, Yakutat and Kodiak. Steady snow fell at Kaltag. On the North Slope, northeasterly winds off the Arctic provided Barrow with a variety of precipitation to include freezing drizzle, ice pellets (sleet) and snow.
The lowest overnight temperature in Alaska as of Sunday was one degree above zero at Anaktuvuk Pass, and the midafternoon highest statewide temperature was 52 degrees at Gustavus, Hydaburg, Hoonah, Klawock and Sitka.
HAWAIIAN WEATHER -- Routine trade weather was found across Hawaii on Sunday as the result of an east-west oriented high pressure ridge that was located approximately 700 miles to the north of the islands. Moderate to fresh northeast trade winds reaching 20 mph were maintained as well as relatively cloud-free skies, with the exception of the clouds and showers on the windward side of the Big Island. The moderate trade winds are expected to continue through the first half of the upcoming week. Small craft warnings were continued for state waters.
WINTER WEATHER AWARENESS -- The states of Colorado, Montana and Wyoming observed their Winter Weather Awareness Week last week (15-21 October 2000). Residents of these states should become aware of the hazards associated with winter storms and other cold weather events by reviewing the material prepared by the local National Weather Service Office. Other states will be observing their own winter weather awareness events during subsequent weeks. Stay tuned for further announcements.
REPORT FROM THE FIELD --Peggy Peters, a DataStreme participant from Battle Mountain, NV reported that she had her students inspect the bikes and the shell/skins that members of the Human Powered Vehicle Association (HPVA) used to break the world speed record on bicycles. The women's team reached a record 55 mph and the men's record over 75 mph. Apparently, the racers indicated that they liked to race when a Low was approaching Nevada.
From the files of the Aviation Weather Center, Kansas City, MO and Intellicast