MORE SNOW FOR THE MIDWEST -- A weak storm system crossing the Great Lakes produced widely scattered snow across the Midwest on Thursday night. A low pressure system was situated over southern Lake Huron with a cold front that trailed southwestward across the Ohio and Mississippi Valleys to Arkansas. Earlier in the evening, light snow fell across Iowa, Minnesota and western Wisconsin, where winter weather advisories had been in effect. Madison, WI received 2.8 inches of snow, representing a record snowfall for the date.
As the storm system moved eastward, the lake-enhanced snow across northern Wisconsin and Michigan's Upper Peninsula will change to a lake-effect event. Northwesterly winds crossing the relatively warm lake waters produce the lake-effect snow along the downwind lakeshore. A variety of lake effect snow warnings and advisories were in effect through Friday morning for counties in both the Upper and Lower Peninsulas of Michigan that are downwind of Lakes Superior and Michigan. Between 3 to 5 inches of new snow could fall across southwestern Lower Michigan. To the east, a lake effect watch was issued for Friday covering northeast Ohio and northwest Pennsylvania, where between 6 to 8 inches could fall.
Closer to the low pressure system, strong west winds that traversed the length of Lake Erie have caused the water level in the western end of the lake to fall well below what is considered safe for navigation.
WET WEATHER ACROSS THE GULF COAST -- A storm system that developed over south Texas on Wednesday moved northeastward across the Gulf of Mexico. With abundantly available Gulf moisture, this system has produced heavy rain across the Gulf Coast, to include many areas that have been under extended drought conditions. Galveston, TX recorded 2.51 inches of rain on Thursday, that established a new daily rainfall record. By Thursday night the low pressure system was situated near Mobile Bay in southern Alabama. A warm front extended eastward along the Gulf coast of the Florida Panhandle, while a cold front trailed to the southwest across the Gulf. An extensive area of precipitation was found to the north and east of the system, extending from southern Mississippi across Alabama and Georgia into the Carolinas. This precipitation was enhanced by the approaching cold front associated with the Great Lakes low pressure system. Some of this precipitation extended westward along the Texas coast and northward into the Middle Atlantic States. Thunderstorms developed across the northern Gulf in the warm sector of the Gulf low pressure system. Earlier, some of these thunderstorms produced high winds that damaged four mobile homes and uprooted trees in the Mississippi Delta of southern Louisiana on Thursday afternoon.
The low pressure system and associated frontal system should move to the east-northeast, reaching the coast of South Carolina by Friday morning. One area of precipitation associated with the low should spread across the Carolinas, while another band of precipitation should remain along the western Gulf, where as much as 2 inches of rain could fall between Friday and Saturday mornings.
CONTINUED COLD WEATHER ACROSS THE WEST -- A large area of high pressure was found across much of the western half of the country. One high pressure center was located over Kansas and Nebraska. Afternoon high temperatures across the central Plains under this high pressure cell ranged from 20 to 25 degrees below the long-term average highs for mid November. Another elongated high pressure center extended southeastward from British Columbia into the Great Basin. This cold high pressure system contributed to several record low temperatures that were either tied or set on Thursday at Eugene, OR (21 degrees) and in California at Lancaster (21 degrees) and Thermal (29 degrees).
While the weather across the West was relatively tranquil on Thursday, an area of snow is expected to fall across the northern Rockies on Friday. A snow advisory was issued for portions of Idaho, to include the Snake Valley, where 2 to 4 inches could fall by late Friday. A blowing snow advisory was also issued for southeastern Montana and northern Wyoming, to include the Big Horn Mountains. A combination of several inches of snow and winds to 30 mph would cause reduced visibility on Friday afternoon. Across the southern Plains, a winter storm watch was posted for north Texas.
Frost advisories were posted for communities along the California coast, extending from Eureka southward to central California to include the San Francisco and Monterey Bay areas, as well as the San Joaquin Valley.
UPPER AIR -- The 500 and 300 mb constant pressure charts for 00Z Friday both have a large height trough across the Great Lakes. A strong jet stream, with southwesterly winds exceeding 130 knots was situated across the lower Mississippi Valley.
TEMPERATURE EXTREMES ACROSS THE CONTINENTAL US -- Thursday's lowest temperature was 14 degrees below zero at Farson, WY. Thursday's highest temperature was 86 degrees at Brownsville, TX.
ALASKAN WEATHER -- Several storm systems produced cloudy skies and gusty winds across the state on Thursday afternoon. One deep low pressure system with an accompanying occluded front was located over the western Bering Sea and western Aleutians. The tight pressure gradient associated with this system created windy conditions across western Alaska. During the afternoon, Dutch Harbor and Portage Glacier reported wind gusts to 61 mph, while Middleton Island had a 48 mph gust and Gambell had a gust to 44 mph. A high wind watch was in effect Thursday night for the Tanana Valley, where gusts to 60 mph were anticipated. Another low pressure center was located over the eastern Alaska Peninsula near King Salmon. An occluded front curved southeastward across the eastern Gulf of Alaska to a third low pressure center near the Queen Charlotte Islands. By midafternoon, Portage Glacier had received 1.73 inches of rain over a 24 hour span. Rain also fell at Kodiak and Yakutat. A stationary front remained along the Arctic coast, separating arctic air from relatively warm air to the south.
The lowest overnight temperature in Alaska on Thursday morning was 20 degrees below zero at Arctic Village, while the mid-afternoon highest statewide temperature was 46 degrees at Klawock.
HAWAIIAN WEATHER -- Gusty east to northeast trade winds with wind speeds on the order of 25 mph continued over the islands on Thursday afternoon. The winds were maintained by a subtropical high pressure cell to the northeast of the islands. Another high is expected to move to the north of the islands behind a weak shear-line that was moving slowly southward. This shear-line, located 200 miles to the north of Kauai, was a remnant of the southern terminus of a midlatitude cold front and represents a region marked by a shift in the surface winds. Relatively dry weather is expected ahead of this shear-line. A high surf advisory was issued on Thursday night for the north and west shores of all the islands, as ocean swell generated by a storm system in the northwest Pacific Ocean has reached the moored buoy near Kauai. This swell could produce 10 to 15 foot surf along the northwest shores of Kauai and Oahu before dawn Friday. Small craft advisories remained in effect for state waters.
REPORT FROM THE FIELD -- Jeff Chapman, a LIT member and a lead forecaster for the National Weather Service in Sioux Falls, SD, reported that a relatively narrow band of snow fell across southeast South Dakota into southwest Minnesota on Wednesday night. This third significant snowfall of November dropped 5 to 8 inches of snow along a band that was between 20 to 30 miles wide. He noted that the snow that has fallen during the first half of November has exceeded the snowfall for the entire cold season of 1999-2000 in several locations, to include Mitchell, SD where 17.6 inches have fallen in November as compared with only 11 inches for last winter.
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Ed HopkinsFrom the files of the Aviation Weather Center, Kansas City, MO and Intellicast