BLUSTERY WEATHER ACROSS THE NORTHEAST -- The storm system that produced heavy snows across portions of the Midwest on Monday moved quickly across the Great Lakes and into the St. Lawrence Valley on Tuesday. By Tuesday night this intense low pressure system was located near Labrador, with a cold front that trailed southward over the western Atlantic Ocean, before crossing the Florida Peninsula. A strong pressure gradient between high pressure over the Midwest and this low pressure center continued to produce strong and gusty northwesterly winds across New England. Earlier on Tuesday, these strong "gradient winds" (used to differentiate from thunderstorm winds) caused some minor wind damage across the Middle Atlantic States. High wind warnings were in effect for a while in New York State and in New England.
As the storm continues to move away to the northeast, the pressure gradient should weaken, accompanied by a slackening of the winds.
ARCTIC AIR SETTLES INTO THE MIDWEST -- High pressure moved across the Midwest in the wake of Monday's storm system, producing unseasonably cold weather across much of the nation's midsection. As of Tuesday night this high pressure system stretched from the Ohio Valley northwestward across the northern Plains and the Prairie Provinces. Arctic air associated with this high pressure has pushed eastward and southward behind a cold front, having spread eastward off the Atlantic Seaboard and southward off the Gulf Coast.
The cold air helped produce record lows from the northern Rockies eastward to the Mississippi Valley. On Tuesday low temperature records were either tied or set in Montana at Bozeman (27 degrees below zero) and Billings (11 degrees below zero); at Aberdeen, SD (25 degrees below); in Nebraska at Chadron (22 degrees below), Alliance (24 degrees below) and Lincoln (14 degrees below); at Casper, WY (17 degrees below); at Eau Claire, WI (18 degrees below); in Iowa at Mason City (16 degrees below), Waterloo (15 degrees below), Cedar Rapids (12 degrees below), Des Moines (11 degrees below) and Dubuque (11 degrees below) and at Moline, IL (12 degrees below zero). While the cold air was primarily responsible for the record lows, a fresh snow cover, along with weak winds under the clear skies of high pressure permitted intense nighttime radiative cooling. Temperatures were slow to rebound on Tuesday afternoon in many locations. Record low high temperatures were either tied or set on Tuesday afternoon in Iowa at Des Moines (one degree above zero) and Dubuque (2 degrees), at Moline, IL (5 degrees) and in Texas at Lubbock (21 degrees), Austin (32 degrees at Bergstrom), San Antonio (34 degrees), Tyler (34 degrees) and Del Rio (41 degrees).
The cold high pressure is expected to drift toward the east on Wednesday.
ICING CONDITIONS ACROSS THE SOUTHERN PLAINS -- Relatively warm and humid air riding up and over the shallow cold air dome across the southern Plains has produced widespread freezing rain across Texas and portions of Oklahoma and Arkansas on Tuesday night. This area of freezing rain was part of a larger area of precipitation that stretched northward from the Rio Grande Valley, where some rain fell in the warm air, and into Kansas, where snow fell in the cold air. Temperatures across north Texas were in the mid 20s as freezing rain was falling. A serious ice storm could result, as ice accumulations could build on surfaces. At least 0.50 inches of rain could fall to form the ice by Wednesday evening. As a result, an ice storm warning was in effect for the western low rolling plains of central Texas to include Big Spring and Colorado City.
The area of wintry precipitation is expected to expand northeastward on Wednesday as a low pressure system that was located over the western Gulf of Mexico moves northward to the Texas Gulf Coast near Galveston by morning and to near Jackson, MS by evening. At that time the precipitation shield is anticipated to have covered the Mississippi and Ohio Valleys. Winter storm warnings covering Tuesday night and Wednesday morning have been in effect for an area that extends from Texas northeastward to the St. Louis metropolitan area in the mid-Mississippi Valley. A freezing rain advisory was posted for portions of Mississippi and several parishes in Louisiana. Winter storm watches for later on Wednesday have been posted in anticipation of the storm movement from southern Ohio and northern Kentucky in the Ohio Valley into the Middle Atlantic States, to include portions of Virginia, Maryland and West Virginia, most of Pennsylvania and western New York State.
To the southeast of the region affected by the snow and freezing rain, a freeze warning was in effect for south Texas, to include the lower Rio Grande Valley.
SNOW ACROSS THE SOUTHERN ROCKIES -- Farther to the west, a surface low pressure center located over New Mexico near the Four Corners produced an area of snow across the northern and central New Mexico. Snow advisories were in effect for much of New Mexico.
ANOTHER STORM ON THE WAY -- A storm that was approximately 900 miles west of the Pacific Coast on Tuesday night is expected to reach the northern California coast by Wednesday evening. A winter storm watch was posted for the mountains in northern California, along with the western slopes of the Sierras south to the Tehachapis, effective Wednesday night and Thursday. As much as a foot of snow is anticipated.
UPPER AIR -- The main feature of interest on the upper air charts for 00Z Wednesday was a height trough over the Southwest.
TEMPERATURE EXTREMES ACROSS THE LOWER 48 -- On Tuesday, the lowest temperature reported in the continental U.S. was 30 degrees below zero at Havre, MT, while Tuesday's high was 86 degrees at Ft. Pierce, FL.
ALASKAN WEATHER -- Arctic high pressure across the Arctic Ocean and northwest Canada coupled with a major storm system over the central Aleutians produced strong east to southeasterly winds across much of Alaska on Tuesday. Cold Bay recorded winds to 75 mph, while Togiak had 63 mph gusts and Gambell experienced gusts to 46 mph. The winds carried warm air toward northwest Alaska. However, arctic air associated with the high pressure system over northwest Canada produced cold conditions across southeast Alaska. Except for the Panhandle, most of Alaska was cloud covered.
The lowest overnight temperature in the state on Tuesday was 17 degrees below zero at Arctic Village, while the midafternoon highest temperature was 45 degrees at Cold Bay, Egegik and Port Heiden.
HAWAIIAN WEATHER -- Following the passage of a cold front across the islands, trade wind weather returned to the Aloha State on Tuesday. High pressure behind the front generated relatively strong northeast trade winds, ranging from 15 to 30 mph. Scattered showers moved toward the Big Island and Maui on Tuesday evening. Relatively dry trade weather should continue for the rest of the week.
High surf advisories continued for the north and west shores of all islands and small craft advisories were issued for all state waters.
From the files of the Aviation Weather Center, Kansas City, MO and Intellicast