NATIONAL WEATHER SUMMARY

JANUARY 20245

Dec31-Jan. 6: The New Year began on a remarkably quiet note, a tranquil period in advance of a barrage of storms, with mild weather and negligible precipitation. However, midto late-week changes included increasing storminess in the Pacific Coast States, which eventually spread farther inland across the Great Basin and Southwest.

mostly dry weather prevailed across the northern Plains and much of the Midwest. Meanwhile, temperatures exhibited a classic El Niño signature, with mild weather across the northern U.S. contrasting with near- or below-normal temperatures in the South. Weekly temperatures averaged more than 10°F above normal across parts of the nation’s northern tier, from northern Montana to the upper Great Lakes region, while readings averaged at least 5°F below normal in scattered locations across the South, primarily in the Desert Southwest and the central Gulf Coast States. Although freezes reached into the South, key winter agricultural regions in California, Florida, Texas, and the Desert Southwest remained above 32°F. While mild weather covered much of the country, temperatures early in 2024 rarely strayed into record-setting territory. Still, many communities in the north-central U.S., including Glasgow, MT, and Rochester, MN, completed a record-warm December, and continued to experience unusually warm weather during the first few days of 2024. Additionally, the U.S. overall experienced record-shattering December warmth, with a national average temperature (40.0°F) that was 7.3°F above the 1901-2000 mean. Late in the week, cooler air— drawn southward by the first in a series of winter storms— began to overspread the West. By January 6, Ramona, CA, posted a daily-record low of 26°F. The first days of 2024 were equally quiet in terms of precipitation.

7-13: Late-week temperatures plunged to -30°F or below, raising concerns regarding the potential for winterkill. The suddenly and dramatically cold air sent weekly temperatures at least 10 to 20°F below normal across the northern and central Plains and parts of the West. The frigid conditions ended a long-running warm spell that had resulted in the nation’s warmest December during the 1895-2023 period of record. The coldest weather, both in absolute terms and relative to normal, was focused across the northern High Plains. Very cold air also spilled across the northern Rockies, with some of the greatest impacts noted across the interior Northwest. In contrast, weekly readings averaged at least 10°F above normal in portions of the Great Lakes States and much of the Northeast, although sharply colder air invaded those regions late in the week. With warm air still in place as the week began, there were a handful of records. Notably, a brief surge of spring-like heat into southern Texas on January 8 led to a daily-record high of 91°F in McAllen. Later, warmth raced into the Atlantic Coast States in advance of a cold front. On January 10, daily-record highs included 59°F in Harrisburg, PA, and 52°F in Portland, ME. Two days later, lingering warmth in southern Florida led to dailyrecord highs of 87°F in Miami and West Palm Beach. Meanwhile, the early stages of a cold outbreak appeared in the West. In California, Campo collected consecutive daily-record lows (19 and 17°F, respectively) on January 8-9. Frigid air made a much stronger push at week’s end across the western and central U.S. For example, Glasgow, MT, experienced its latestever first sub-zero reading of the winter on January 8, breaking a record set on January 2, 1998. Subsequently, Glasgow plunged to -35°F on January 13, a record low for the date. Elsewhere in Montana, the 13th featured dailyrecord lows of -48°F in Dunkirk; -45°F in Bozeman; -45°F in Butte; -43°F in Lewistown; -42°F in Havre; and -41°F in Cut Bank. Great Falls, MT, reported a January 13 minimum temperature of -37°F with an official snow depth of just 1 inch, leading to concerns for winter wheat exposure. On that date, the coldest air in 27 years settled across Sheridan, WY (-31°F), and Billings, MT (-26°F); on January 12, 1997, respective lows had dipped to -35 and -30°F. Maximum temperatures did not appreciably recover on January 13, peaking at sub-zero levels as far south as Goodland, KS (-2°F), and Grand Island, NE (-1°F). More details on the Arctic outbreak, which continued for several days, will appear next week.

14-20: Light precipitation fell across much of the country. In fact, dry weather prevailed in the north-central U.S., as well as the southern Plains and much of the Southwest. However, other areas—including the central Plains, western Corn Belt, and eastern one-third of the nation— received some precipitation. Accumulating snow fell as far south as the northern Mississippi Delta and the Tennessee Valley, as well as the middle Atlantic States.

In the West, precipitation increased as cold air eroded. The heaviest precipitation fell in northern California and the Pacific Northwest, but most areas from the West Coast to the northern and central Rockies received some rain or snow, or a combination of both.

Cold air was slower to depart the Northwest, resulting in some wintry weather, including freezing rain, as moisture arrived. Livestock producers continued to contend with difficult conditions, especially in areas where bitterly cold weather trailed back-to-back snowstorms. With cold, windy weather lingering for much of week and some additional snow falling, rural travel remained difficult from the central Plains into parts of the Midwest. Weekly temperatures averaged at least 10 to 25°F below normal throughout the Plains, Midwest, Northwest, and mid-South. The frigid, snowy weather followed the recordsetting warmth of December. Temperatures remained above 32°F in Florida’s key winter agricultural areas. Weekly readings averaged at least 5°F above normal in parts of southern Florida, along with several locations in California, the Great Basin, and the Southwest. Frigid weather gripped much of the country as the week began, with daily-record lows plunging below -40°F on January 14 in Montana locations such as Havre and Dunkirk—both at -44°F. An observation site near Saco, MT, reported -51°F on the 14th, setting an all-time station record (previously, -50°F on January 25, 1969). Farther south, Kansas City, MO, reported January 14 maximum and minimum temperatures of -3 and -12°F, respectively, marking the coldest day in that location— based on average temperature—since December 22, 1989. Kansas City plunged to -16°F the next day, January 15. Elsewhere on the 15th, a trace of snow fell as far south as Laredo and Victoria, TX. By January 16, daily-record lows in Texas included 0°F in Amarillo, 5°F in Lubbock, 26°F in Harlingen, and 28°F in McAllen. Sub-zero, daily-record for the 16th included -10°F in Fayetteville, AR; -7°F in Joplin, MO; -6°F in Jackson, TN; and -2°F in Tulsa, OK. Jackson, TN, was even colder on January 17, dipping to -10°F. In Louisiana, consecutive daily-record lows were established on January 16-17 in locations such as Alexandria (16 and 12°F) and Lake Charles (19°F both days). In contrast, lingering warmth in southern Florida resulted in daily-record highs of 85°F on January 16 in Fort Lauderdale and West Palm Beach.

21-27: Many other parts of the U.S., including the southern Atlantic region, the northwestern half of the Plains, and the far upper Midwest, received little or no precipitation.

After snow blanketed a peak of nearly 59 percent of the U.S. on January 17, coverage dropped to less than one-third (33 percent) of the Lower 48 States just 12 days later.

Roughly a 10-day period of extreme cold, peaking in mid-January— weekly temperatures surged at least 10 to 15°F above normal across portions of the nation’s northern tier, especially from the northern Plains into the Great Lakes States. Readings also averaged more than 10°F above normal in parts of the East and northern Intermountain West. Cool weather lingered in a few areas, including the southern Plains, where slightly below normal temperatures were observed in portions of Oklahoma and northern Texas. With the dramatic warm-up, temperatures in some Montana locations rose more than 100°F in 15 days. For example, the temperature in Lewistown, MT, rebounded from -43°F on January 13 to reach 58°F by January 28. Similarly, the temperature in Cut Bank, MT, rose 103°F (from -41 to 62°F) between January 13 and 29. Olympia, WA, which had posted consecutive daily record-tying lows (15 and 16°F, respectively) on January 15-16, notched a daily record high of 56°F on January 23. A string of daily-record highs in Olympia—61, 63, and 59°F—began on January 27. During the mid- to late-week period, warmth exploded across the southern and eastern U.S., with Tallahassee, FL, collecting a daily record-tying high of 80°F on January 24. In many areas of Florida, warmth peaked on January 27 with daily-record highs of 86°F in Punta Gorda; 85°F in Lakeland; and 84°F in Jacksonville. However, the overall most impressive day of Eastern warmth occurred on January 26, with monthly records attained in locations such as Wilmington, NC (83°F; previously, 82°F on January 31, 1975), and Washington, DC (80°F; previously, 79°F on January 26, 1950). Unusual warmth also continued in the West, where daily-record highs for January 27 rose to 80°F in Ontario, CA, and 63°F in Salem, OR. The following day, the 28th, Salem tied a monthly record—most recent achieved on January 27, 1931—with a high of 69°F.

 

 

Jim G. Munley, jr.
http://www.jimmunleywx.com