The following highlights of the national weather have been extracted from the surface weather map for Tuesday night:
ANOTHER WARM OCTOBER DAY -- Much of the nation experienced unseasonably warm weather on Tuesday as high temperatures from the central Rockies eastward to the Middle Atlantic States ranged between 10 to 15 degrees above the average highs for the third week of October. Only the northern Plains and interior sections of the Northwest had high temperatures that were below average. Highs in North Dakota to the north of a cold front were at least 10 degrees below average. Record high temperatures were either tied or exceeded in Texas at Del Rio (93 degrees), Wichita Falls (91 degrees) and Waco (89 degrees); in South Carolina at Florence (87 degrees) and North Myrtle Beach (81 degrees) and in North Carolina at Raleigh-Durham (85 degrees). In addition, the unseasonably warm air mass along the Gulf Coast contributed to several high minimum temperature records being tied or broken in Texas at Lufkin (71 degrees) and Longview (70 degrees); in Oklahoma at McAlester (71 degrees); in Louisiana at Shreveport (70 degrees); in Arkansas at Texarkana, Fayetteville and Ft. Smith (all 69 degrees); and in Tennessee at Memphis (69 degrees) and Dyersburg (66 degrees).
MORE SEVERE WEATHER ACROSS THE MIDWEST -- Several bands of severe thunderstorms moved across the Midwest. During the midday hours, severe thunderstorms moved eastward from Missouri across Illinois into southern Indiana along the Ohio River. An unconfirmed tornado was reported by the public southwest of Jefferson City in central Missouri. Thunderstorm winds produced some damage in Missouri, downing power lines and trees. Some of the quarter-sized hail in southeast Missouri accumulated to depths of 2 to 3 inches.
On Tuesday evening, more severe thunderstorms developed in Missouri along the western end of a cold front that trailed southwestward across the eastern Great Lakes and into the mid-Mississippi Valley from a low pressure system located over Quebec. Numerous strong thunderstorms were associated with this cold front, stretching from central Missouri across southern Illinois and Indiana into Ohio.
Farther to the north, strong to severe thunderstorms moved across northern Illinois and southern Wisconsin in the vicinity of Freeport and Rockford in Illinois and the Beloit-Janesville area in Wisconsin. These thunderstorms were to the north of a warm front that extended eastward from a low pressure region over the eastern Dakotas and Nebraska. These thunderstorms produced large hail. Twenty minutes of continuously falling hail, with diameters up to 1.50 inches, covered the ground near Freeport late in the evening. A funnel cloud was reported near Beloit along the Wisconsin-Illinois border.
A slight risk of severe thunderstorms continues through Tuesday night across the mid Mississippi and Ohio Valleys. On Wednesday, a cold front is expected to sweep southeastward across the Midwest. Thunderstorm activity is expected in the warm, humid and unstable air to the south and east of the advancing cold front. As a result, residents across western Kentucky, much of Indiana, Ohio and southeastern Lower Michigan are under a moderate risk of severe thunderstorms during Wednesday. Surrounding this region of moderate risk, a larger area that could experience a slight risk of severe weather extends from the lower Mississippi Valley northeastward to the Great Lakes. In addition to the possible severe weather, heavy rain is expected. Between 0.50 and 1.75 inches of rain could fall in the 24 hours ending on Wednesday evening extending from the lower Ohio Valley, crossing the Great Lakes and Middle Atlantic States to reach New England.
WINTRY WEATHER MOVES INTO THE NORTHERN PLAINS -- Light snow was spreading across North Dakota in the cold air behind a cold front that extended westward across the state on Tuesday night. As the complex low pressure system located over eastern South Dakota moves eastward on Wednesday, a secondary cold front is expected to move southward and eastward across the Plains into the Mississippi Valley and western Great Lakes. Behind this front, light snow and snowshowers are anticipated to spread across the Dakotas and into northern Minnesota. Winter weather advisories were in effect for northwestern North Dakota where 1 to 3 inches of snow were anticipated by Wednesday morning. A winter storm watch was posted for western portions of Michigan's Upper Peninsula as 6 to 10 inches of lake-effect snow are anticipated on Thursday.
UNSETTLED WEATHER CONTINUES IN THE WEST -- High pressure from over the eastern Pacific Ocean was moving toward the Oregon coast following the cold front that crossed the Pacific Northwest late Monday. A relatively tight pressure gradient between this high pressure center located at least 500 miles west of Cape Blanco, OR and lower pressure over interior North America continued to produce strong winds across the West. Some winds in eastern Oregon and Washington had gusts to 65 mph earlier on Tuesday. High winds toppled trees in the Blue Mountains of northeast Oregon on Tuesday morning. Wind damage was also sustained near Port Angeles on Washington's Olympic Peninsula.
Gale warnings for winds between 39 and 54 mph were continued on Tuesday night for the Washington coast north of Cape Shoalwater, to include the northern portion of Puget Sound. A storm warning for winds in excess of 59 mph was in effect for the Strait of Juan de Fuca. Gale warnings were also in effect for the central and southern California coast from Pigeon Point to Santa Cruz Island. Heavy surf advisories covered the Northwest coast from Cape Flattery, WA to Florence, OR and the northern California coast from Point St. George to Point Reyes.
High wind warnings were in effect for the mountains of Colorado and the Guadalupe Mountains of southern New Mexico and west Texas. Winds gusting to 60 mph were anticipated.
A persistent westerly wind around the northern flank of the ridge of high pressure meant that light snow continued across the mountains of Washington, Idaho and Montana, the result of orographic lifting. Some mountain locations in eastern Washington and northern Idaho reported 5 inches of new snow on Tuesday morning. This orographically-induced precipitation is expected to continue into Wednesday as the high pressure ridge moves into Oregon.
YESTERDAY'S TEMPERATURE EXTREMES ACROSS THE CONTINENTAL US -- Tuesday morning's lowest temperature was 20 degrees at Alamosa, CO, while the highest temperature on Tuesday was 97 degrees at Del Rio (Laughlin AFB), TX.
ALASKAN WEATHER -- A large low pressure system located over the north central Gulf of Alaska dominated much of Alaska's weather on Tuesday afternoon. The counterclockwise circulation around this low pressure center produced southeasterly winds across the Panhandle and Southeast Alaska, which were located to the east of the low, easterly to northeasterly winds across much of interior and northern Alaska to the north of the low, but northwesterly winds across western Alaska, the Alaska Peninsula and the eastern Aleutians to the west and northwest of the storm. The southeasterly winds across the Panhandle maintained temperatures in the 40s. Easterly winds across south central Alaska gusted to 35 mph at Seward. Temperatures across south central Alaska were in the 20s during midafternoon. Farther north in the interior, snow fell at several locations and temperatures were in the teens. Northeasterly winds were found along the North Slope, with midday temperatures in the single digits above and below zero. With winds across Northwest Alaska reaching to nearly 25 mph, wind-chill equivalent temperatures were between 10 to 20 degrees below zero. Snow fell at Deadhorse in the afternoon. Northwesterly winds across southwest Alaska produced temperatures that ranged between the upper teens to mid 30s. Dutch Harbor reported wind gusts to 35 mph. Sand Point had snowshowers. High pressure was located across the western Aleutians.
The state's lowest overnight temperature on Tuesday morning was 11 degrees below zero at Stony River. The highest temperature by mid afternoon of Tuesday was 48 degrees at Klawock.
HAWAIIAN WEATHER -- A surface trough of low pressure that was forming to the east of the Aloha State has been contributing to the decrease in the trade winds across the islands. These trades are expected to have wind speeds ranging between 5 to 15 mph into Friday. In addition to the decreased winds, increased atmospheric humidity and decreased atmospheric stability should increase the chance of showers and thunderstorms. Clouds from these showers and thunderstorms were approaching the Big Island late Tuesday afternoon.
PARTLY CLOUDY OR PARTLY SUNNY? You have probably wondered if a distinction exists. If you are curious, refer to the optional electronic Supplemental Information for Wednesday.
From the files of the Aviation Weather Center, Kansas City, MO and Intellicast