A WARM START TO NOVEMBER -- Much of the country east of the Rockies experienced unseasonably warm weather with high temperatures ranging between 10 to 20 degrees above the average highs for the beginning of November. Only Florida and northern Maine had highs that were within several degrees of the average highs for their respective locations. Record high temperatures were set on Thursday in Texas at Wichita Falls and Midland (both 87 degrees).
A large ridge of high pressure centered over the western North Atlantic extended southwestward across the Southeast. With a strong low pressure system moving across northern Ontario, relatively strong southerly winds were found across much of the Mississippi Valley, helping spread warm air across the eastern half of the country. A warm front that stretched across Ontario, Quebec and northern New England marked the leading edge of the warm air. The air to the west of the cold front that trailed southwestward across the upper Mississippi Valley and the Plains was not that sufficiently cold since this relatively mild air mass had origins over the north Pacific and had been modified upon travel over the Cascades and the Rockies.
With nighttime cooling of the humid Gulf air across the South, fog was beginning to form late Thursday night. Because of the significantly reduced visibility along the Gulf coast, dense fog advisories were posted from Louisiana eastward to the Florida Panhandle.
UNSETTLED WEATHER MOVES THROUGH THE MIDWEST -- Some rainshowers and thunderstorms moved across the Midwest ahead of a cold front that stretched southwestward from Lake Superior to northern Kansas. Most of the precipitation was found across northern and west central Illinois, much of Missouri and eastern Kansas. Heavy rains were falling across southeastern Kansas with 2 to 4 inch accumulations over several hours late Thursday night as estimated by Doppler radar. Urban and small steam flood advisories were posted around Pittsburg. Additional widely scattered precipitation was also found across the eastern Great Lakes.
The cold front trailed from a strong low pressure system located in Ontario to the west of James Bay. On Friday this low pressure center is expected to move across James Bay and proceed into northern Quebec by evening, with the cold front moving eastward across the Great Lakes and southward to the Ohio Valley. With a continued flow of moist air northward ahead of the front, more widespread showers and thunderstorms should develop across the Midwest on Friday. Between 0.1 to 0.8 inches could fall in the 24 hours ending on Friday evening across the eastern Lakes, along the Ohio Valley and into the mid-Mississippi Valley.
WINDY WEATHER PERSISTS OVER FLORIDA -- With the ridge of high pressure located to the north and lower pressure over the tropics, a relatively tight pressure gradient was found across Florida resulting in continued strong easterly winds. These persistent onshore winds along Florida's Atlantic coast have caused beach erosion as water has been piled against the shore. High astronomical tides associated with the full moon are exacerbating the situation. A coastal flood watch was posted along the coast from Jupiter Inlet south to Ocean Reef. Heavy surf advisories were also continued through Friday for the coast from Flagler Beach south to Ocean Reef.
ANOTHER FRONT REACHES THE NORTHWEST -- The next cold front had just reached Washington State's Olympic Peninsula on Thursday evening. This front trailed southward from a storm system centered over the northern Gulf of Alaska. A weak low pressure center had developed along the front over Vancouver Island. An area of precipitation was found along the western Columbia River Valley.
The front is expected to move into interior sections of the Northwest on Friday. Additional precipitation is anticipated to follow behind the cold frontal passage. Most of this precipitation should be relatively light, with 0.1 inch falling by Friday evening across western Washington and Oregon, as well as the mountains of northern Idaho and eastern Oregon.
UPPER AIR -- Both the 500 and 300 mb charts for 00Z Friday show a relatively zonal flow, as the strongest winds especially across the northern half of the country are traveling primarily from west to east with only small excursions to the north and south. With such a zonal flow weather systems move relatively quickly from west to east, as is currently the case. A weak height trough is found on both charts over the northern Plains, with winds deflected slightly to the south of the predominate west to east flow. This trough is associated with the strong surface storm system over western Ontario.
TEMPERATURE EXTREMES ACROSS THE CONTINENTAL US -- Thursday's lowest temperature was 15 degrees at Bridgeport, CA. Thursday's highest temperature was 92 degrees at Borrego, CA.
ALASKAN WEATHER -- A large storm system located over the northern Gulf of Alaska was responsible for clouds and precipitation across much of the state on Thursday afternoon. The low pressure center, with a central pressure of approximately 977 mb, was located just south of Prince William Sound. An occluded front associated with this system curved eastward across southeast Alaska and southern Yukon Territory before turning southward across British Columbia, to then become a cold front along the Washington and Oregon coast. A cold front stretched from the vicinity of the low pressure system westward along the Aleutians. Both rain and snow were reported across much of southern Alaska, from the Aleutians eastward across south central Alaska to the Panhandle. Gusty winds were also found along the Panhandle, where gusts reached at least 40 mph. Winds and snow were also found across northern Alaska. With an anticipated intensification of the storm in the Gulf of Alaska, a high wind watch was in effect for coastal regions of southeast Alaska from Friday night into Saturday as easterly winds increase to 50 mph, accompanied by gusts to 60 mph.
The lowest overnight temperature in Alaska on Thursday morning was 22 degrees below zero at Nuiqsut, while the mid-afternoon highest statewide temperature was 47 degrees at Annette.
HAWAIIAN WEATHER -- A subtropical ridge of high pressure located to the north of the islands continued to maintain northeasterly trade winds across the Aloha State on Thursday. These trades had speeds that ranged between 10 to 25 mph. The high is expected to weaken starting on Friday evening as a front approaches and stalls approximately 500 miles to the north of Hawaii. As a result, the trade winds are anticipated to weaken to speeds between 10 and 20 mph by Saturday. Bands of low clouds found several hundred miles upstream from the islands are expected to bring frequent trade showers to the state through Saturday. Small craft advisories remained in effect for state waters.
EYE ON THE TROPICS -- Tropical Storm Michelle continued moving northward across the western Caribbean on Thursday. Its position late on Thursday night was approximately 300 miles south-southeast of the western end of Cuba. Movement was to the north-northwest at 5 mph. Maximum sustained winds were 65 mph and the central pressure was estimated to be 991 mb. A large precipitation shield surrounded this storm. Cuba, Jamaica and other Caribbean islands have received heavy rains from Michelle. Hurricane watches are in effect across western Cuba as Michelle is expected to intensify to hurricane status (with maximum sustained surface winds exceeding 74 mph) and reach Cuba over the weekend.
In the eastern North Pacific, Tropical Storm Octave intensified to hurricane status on Thursday. As of Thursday evening, Hurricane Octave had maximum sustained winds of 85 mph. Its position was approximately 1285 miles west-southwest of Cabo San Lucas, Mexico and its forward motion was to the north-northwest at 9 mph.
From the files of the Aviation Weather Center, Kansas City, MO and Intellicast
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.