NATIONAL WEATHER SUMMARY

OCTOBER 2024

Sep. 29-Oct. 5: The remnants of Hurricane Helene, which in late September had become entangled with a disturbance crossing the Mississippi Valley, drifted eastward across the middle Atlantic States, generating some early-week rain. Meanwhile, in the wake of historic, catastrophic, and deadly flooding in the southern Appalachians, search and recovery efforts proceeded amid warm, mostly dry conditions.

There over 200 confirmed fatalities, many due to inland flooding, Helene became the deadliest Atlantic hurricane to strike the U.S. mainland since Katrina in 2005. Post-hurricane assessments and repairs extended to areas of the Southeast hit hard by Helene’s high winds and—along a portion of Florida’s Gulf Coast—a record-setting storm surge.

September records for dryness were broken in numerous locations across the northern Plains and Midwest. In fact, monthly totals less than one-tenth of an inch were the lowest on record in locations such as Mobridge, SD (0.01 inch); Norfolk, NE (0.03 inch); Sioux Falls, SD (0.04 inch); Minneapolis-St. Paul, MN (0.06 inch); Fargo, ND (0.08 inch); and Omaha, NE (0.09 inch). Dryness extended into parts of the mid-South, where Fayetteville, AR (0.16 inch), also set a September record for dryness (previously, 0.40 inch in 1952). As September ended, rainfall in the mid-Atlantic was not overly heavy, as the weakening remnants of Helene finally moved offshore.

6-12: Category 3 Hurricane Milton slammed into Florida’s Gulf Coast just south of Sarasota at 8:30 pm EDT on October 9, packing maximum sustained winds near 120 mph. Milton’s interaction with an approaching cold front led to some of the harshest conditions—including high winds (gusts above 100 mph) and flooding rains (locally 12 to 20 inches)—occurring on the northern side of the storm, encompassing the Tampa Bay area.

Areas such as the Plains and Northwest, recently planted wheat largely lacked moisture for proper autumn establishment. Additionally, dryness resulted in declining rangeland and pasture conditions, especially where record-setting warmth prevailed. Weekly temperatures averaged 5 to 15°F above normal from the West Coast to the Plains, except in the Pacific Northwest. Some of the warmest weather, relative to normal, stretched from California and the Desert Southwest to the Dakotas, with a separate area of unusual warmth covering the southern Plains. Most of the Midwest continued to avoid a freeze. Elsewhere, near- or slightly below normal weekly temperatures affected the eastern U.S.

Phoenix, AZ, reported a high temperature of 103°F or greater each of the 22 days from September 23 – October 14. Prior to this year, Phoenix had never experienced more than 8 days of 103-degree heat in October. Phoenix also registered highs of 110°F or greater on October 1, 5, 6, and 7, boosting its record-high annual total to 70 days (previously, 55 days in 2023). In California, high temperatures of 100°F or greater occurred on each of the first 7 days of October in Palmdale and Lancaster. Previous October records had been 5 days (in 1980) in Palmdale and 4 days (in 2020) in Lancaster. Sandberg, CA, reached 90°F or higher from October 1-7, breaking the monthly record of 5 days, set in 1980 and 2020. Las Vegas, NV, noted its last 100°F reading of the year on October 6, breaking the city’s record for the latest triple-digit heat, originally set on October 4, 1947. Widespread, triple-digit heat in California’s Central Valley persisted through October 7, when daily-record highs included 101°F in Sacramento and 100°F in Hanford. A separate area of heat across the south-central U.S. led to temperatures reaching or exceeding 90°F on each of the first 15 days of October in locations such as Austin, Del Rio, and San Antonio. Austin’s previous standard for 90-degree readings in October was 13 days in 2007. During the mid- to late-week period, warmth further overspread the Plains and Midwest. With a high of 101°F on October 12, Childress, TX, came within a day of its latest triple-digit heat on record, achieved on October 13, 1954. Midwestern daily-record highs attained the 90-degree mark in locations such as Lincoln, NE (91°F on October 10); Quincy, IL (90°F on October 12); and Joplin, MO (93°F on October 12). Back in the Southwest, Tucson, AZ, reached or exceeded 100°F on each of the first 13 days of the month, smashing its October record of eight triple-digit readings in October 2020.

13-19: Another week of mostly dry weather across the Plains, Midwest, and. However, ongoing dryness also resulted in reduced moisture as declining rangeland and pasture conditions. Across the eastern half of the country, spotty showers were confined to Deep South Texas, the southern tip of Florida, and an area stretching from the Great Lakes region into the Northeast.

Temperatures averaged at least 5°F above normal across large sections of the northern Plains, Rockies, and Intermountain West. Readings averaged as much as 10°F above normal in parts of the northern and central Rockies and adjacent High Plains. Meanwhile, a fleeting cool spell ended the growing season across the northern and central Plains and large sections of the Midwest. Temperatures averaged at least 5 to 10°F below normal in much of the Southeast, as well as portions of the Ohio Valley and Northeast. In the South, scattered frost and light freezes were reported on multiple days as far south as Arkansas and northern sections of Mississippi, Alabama, and Georgia. The first notable cold wave of the season resulted in several daily-record lows, starting on October 16. On that date, lows—all records for the date—dipped to 24°F in Hill City and Salina, KS; 24°F in Dubuque, IA; 27°F in Springfield, IL; and 28°F in Vichy-Rolla, MO. Elsewhere in Missouri, Cape Girardeau collected consecutive daily record lows (30 and 28°F, respectively) on October 16-17. With a minimum temperature of 24°F on October 17, Lincoln, IL, noted its lowest reading since March 28. Chilly weather briefly extended to the southern Plains and Southeast; record-setting lows for October 17 included 33°F in Oklahoma City, OK, and 35°F in Alexandria, LA, and Macon, GA. In advance of the cool spell, summer-like heat had prevailed across the nation’s southern tier. In Arizona, triple-digit heat occurred on each of the first 13 days of October in Tucson and 14 days in Phoenix. Tucson had never recorded more than 8 October days (in 2020) with high temperatures reaching 100°F or higher. Meanwhile in Texas, Austin (Camp Mabry) set a monthly record with a high of 101°F on October 13 (previously, 100°F on October 2, 1923, and October 2, 1938). On the 14th, Houston, TX, tied a monthly record originally set with a high of 99°F on October 1, 1900. With maxima of 104 and 100°F, respectively, on October 13 and 15, Waco, TX, set multiple records, including highest October reading and most days of triple-digit heat during October. Waco had never experienced more than a single day of triple-digit October heat, and the monthly standard had been 101°F on October 3, 1979, and October 2, 1989. Prior to this year, Waco’s latest date with a high of 100°F or greater had been October 12, 2022. During the second half of the week, warmth on the northern Plains replaced previously cool conditions. In South Dakota, record-breaking highs for October 17 soared to 90°F in Pierre and 85°F in Mobridge. As chilly air arrived in the central and eastern U.S., snow dusted a few areas from the Great Lakes States into the Appalachians. On October 15, Columbus, OH, received snowfall totaling 0.1 inch, while Charleston, WV, noted a trace.

20-26: Exceptions to the dry pattern included lingering, early-week rainfall in eastern New Mexico and environs, as well as late-week precipitation overspreading the Northwest. The Northwestern storminess signaled the early signs of a pattern change, which—if realized—would greatly benefit drought stressed rangeland and pastures, as well as emerging winter wheat and cover crops. Still, portions of the central and eastern U.S., excluding Florida’s peninsula, continued to lurch toward a near-record or record-dry October, with some locations having reported no measurable precipitation during the first 26 days of the month.

. Weekly temperatures averaged at least 10°F above normal across parts of the southeastern Plains and the mid-South, as well as an area encompassing the upper Midwest. Similar temperature departures were observed in the Northeast. A broader area, extending from the Rockies into the mid-South and Midwest, reported temperatures ranging from 5 to 10°F above normal. Elsewhere, near-normal weekly readings were noted in the Pacific Northwest and middle and southern Atlantic States. As the week began, record-setting warmth stretched from the Great Lakes States into the Northeast. In Michigan, Traverse City posted consecutive daily-record highs (79 and 83°F, respectively) on October 20 21. In New England, record-setting highs for October 21 included 78°F in Portland, ME, and 77°F in Burlington, VT. Burlington collected another daily-record high (78°F) on October 23. In the mid-Atlantic, record setting highs for October 22 soared to 86°F in Reading, PA, and 84°F in Georgetown, DE. Meanwhile, summer-like heat returned across the southern Plains and Southwest. Tucson, AZ, reported daily-record highs each day from October 22-23 and 25-27, with temperature peaking at 99°F on the 23rd and 26th. Elsewhere in Arizona, the high of 100°F in Phoenix on October 26 occurred just a day before the latest triple-digit reading on record in that location (100°F on October 27, 2016). Farther east, daily record highs reached 90°F on October 22 in locations such as Lubbock, TX, and Fort Smith, AR, while Chanute, KS, soared to 93°F. Fort Smith’s streak of 90-degree days lasted a total of 3 days, with additional daily records (93, 91, and 89°F) being set on October 23, 24, and 25. Shreveport, LA, achieved a high of 90°F or greater each day from October 23-27, tying or breaking a record each day, except the 25th. Highs in Shreveport peaked at 92°F on October 23 and 26. With 90-degree heat surging across central Plains and southern Corn Belt, daily-record highs for October 24 reached 93°F in Wichita, KS, and 90°F in Joplin, MO. Similar readings spread into the Southeast, where record-setting highs for October 25 climbed to 91°F in Tallahassee, FL, and 90°F in Montgomery, AL. Tallahassee attained 91°F again on October 26, setting another record. Other Southeastern daily-record highs for the 26th included 90°F in Mobile, AL, and 88°F in Columbia, SC. In contrast, cool air settling into the Pacific Coast States led to daily-record lows in locations such as Ellensburg, WA (23°F on October 23), and Montague, CA (23°F on October 24). Expansive dryness remained an overarching theme, with dozens of climate stations across the central and eastern U.S. reporting either zero precipitation or a trace of rain during the first 28 days of October. 

 

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