NATIONAL WEATHER SUMMARY

 

SEPTEMBER 2022

 

Aus. 28-Sep. 3: Drought-easing rain in the south-central U.S. arrived too late for many summer crops—but boosted topsoil in advance of autumn planting operations and helped to revive rangeland and pastures. Some of the heaviest and most widespread rain fell in parts of Texas.

 

Little or no rain fell in late August and early September northwest of a line from the southern Rockies into the upper Great Lakes region. Sizzling temperatures accompanied the dry weather, abetting wildfire growth, reducing soil moisture, boosting irrigation demands, and bringing renewed stress to rangeland and pastures. Dry weather extended into the western Corn Belt, maintaining stress on immature summer crops. Farther east, however, scattered but generally beneficial showers extended from the middle and upper Mississippi Valley into the Northeast. Elsewhere, favorably drier weather developed in much of the Southeast, following recent downpours.

 

Cooler-than-normal conditions were mostly limited to portions of the Rio Grande Valley, where cloudiness and showers helped to suppress temperatures. Nearnormal weekly temperatures were common elsewhere in the South, extending northward into the lower Ohio Valley and environs. Above-normal temperatures dominated the remainder of the country, with the hottest weather—relative to normal—focused across the northern High Plains and much of the West. Weekly temperatures averaged at least 10°F above normal in numerous locations from interior sections of the Pacific Coast States to the Great Basin, Intermountain West, and northern High Plains. Late-season warmth (temperatures averaging 5°F or more above normal in many places) also extended eastward across the Great Lakes region and parts of the Northeast. Some of the hottest September weather on record developed from the Pacific Coast to the High Plains. In fact, September temperature records were tied or broken during the first 3 days of the month in locations such as Lancaster, CA (112°F on the 1st); Pendleton, OR (104°F on the 2nd); and Pocatello, ID (102°F on the 3rd). Earlier, a trickle of daily records began in late August. By the 30th, Portland, OR, attained 100°F, its fifth triple-digit reading of the year. The only other times Portland recorded five 100-degree daysin a year were 1941, 1977, and 2021. Meanwhile in Washington, Seattle (90°F on August 30) noted its 12th day this year with a high of 90°F or greater, tying an annual record set in 2015. Record-setting heat expanded to the remainder of the West on the last day of August, with southern California locations such as Burbank (112°F) and Anaheim (106°F) setting monthly record highs. Burbank’srecord had been on the books since August 26, 1944, when the high reached 111°F. On the strength of the late-month heat wave, several Northwestern communities— including Dallesport, WA, and Redmond, OR—completed their hottest August, breaking records that had been set in 1967. September began with another wave of record-shattering high temperatures. In fact, Desert Rock, NV, tied a monthly record with highs of 109°F on September 1 and 2, followed by a high of 110°F on September 6. Salt Lake City, UT, posted a monthly record high (102°F; previously, 100°F on September 5, 2020, and earlier dates) on the 1st, but later shattered that mark with 103°F on the 3rd; 104°F on the 5th; and 105°F on the 6th. On September 2, another surge of Northwestern heat led to monthly record highs in Oregon locations such as Redmond (106°F) and Pendleton (104°F). Pendleton tied a record originally set on September 3, 1930. By September 3, monthly records were shattered in parts of Idaho, with highs reaching 102°F in Pocatello, 100°F in Idaho Falls, and 99°F in Burley and Challis. Burley’s monthly record was broken on September 6, with a high of 101°F, while Challis again reached 99°F.

 

4-10: Variable rainfall across the Plains and Midwest arrived too late to benefit most summer crops but locally boosted soil moisture in advance of the winter wheat establishment season. Even with the showers, parts of the northern and central Plains remained extremely dry.

 

One of the hottest weeks ever observed at any time of year across California, the Great Basin, and the Intermountain West resulted in hundreds of daily-record high temperatures; dozens of monthly record highs; and several all-time records. Weekly temperatures averaged at least 15°F above normal in several locations across California, while readings averaged more than 10°F above normal as far east as western Colorado. In fact, heat broadly prevailed in the Northeast and west of a line from the southern Rockies to the upper Great Lakes region. In contrast, near- or slightly below-normal temperatures covered the Deep South, from the Rio Grande Valley to the Gulf Coast region. In California, the intense heat generally peaked on September 6 with never-before-seen temperatures in locations such as Ukiah (117°F), downtown Sacramento (116°F), Livermore (116°F), King City (116°F), Merced (116°F), Santa Rosa (115°F), and Stockton (115°F). Livermore had also attained 116°F on September 5. The previous record in downtown Sacramento, 114°F, had been set on July 17, 1925. Ukiah’s former record, 115°F, had stood since September 3, 1955. Elsewhere on the 6th, Death Valley (125°F) matched its monthly record, originally set on September 5, 2020. Monthly record highs returned to Idaho, with Burley (101°F on the 6th) topping its September record set just 3 days earlier. The warmest September weather on record also extended to the western slopes of the Rockies on September 6; in Colorado, Grand Junction’s high of 102°F marked the first time that city had topped the 100-degree mark after the end of meteorological summer. Meanwhile, Salt Lake City, UT, posted a monthly record high (102°F; previously, 100°F on multiple dates) on September 1, but went on to shatter that record with 103°F on the 3rd, 104°F on the 5th, 105°F on the 6th, and 107°F on the 7th. Salt Lake City’s final reading tied an all-time station record, previously set on July 17, 2022, and earlier dates. Similarly, Reno, NV, smashed its monthly record on the 4th with a high of 104°F (previously 102°F on September 4, 2020)—but later demolished that mark with a reading of 106°F on the 6th. In addition, Reno began September with 8 consecutive days of 100-degree heat. Reno’s record for 100-degree days in September had been 3 days in 2017. Except several times in July (2003, 2005, 2018, 2021, and 2022), there has never been a month in Reno with more than 8 days of triple-digit heat. Farther north, the week began on September 4 with monthly record highs in Wyoming locations such as Worland (102°F), Casper (100°F), Riverton (100°F), Lander (99°F), and Rock Springs (93°F). By September 7, a surge of heat in advance of a cold front led to the latest triple-digit heat on record in Montana locations such as Glasgow (106°F), Havre (104°F), Helena (102°F), and Lewistown (100°F). All those locations also set September records. A day later in Nebraska, Valentine (106°F on September 8) tied a monthly record previously set on September 9, 1931, and September 5, 2020. Late in the week, however, signs of autumn appeared across the Plains and Northwest. On September 10, just 3 days after posting a monthly record-tying high of 102°F, Livingston, MT, collected a daily-record low of 27°F. The following morning, September 11, daily-record lows dipped to 25°F in Laramie, WY, and 41°F in Garden City, KS.

 

11-17: California and the Northwest, cooler, more humid conditions aided wildfire containment efforts. Still, smoky conditions and air-quality issues continued to plague parts of the West. By mid-September, three active wildfires—Idaho’s Moose Fire and Oregon’s Cedar Creek and Double Creek Fires—had each burned more than 100,000 acres. As record-setting heat shifted eastward, weekly temperatures averaged at least 5°F above normal across parts of the Plains, particularly from Montana to Kansas. Meanwhile, near-normal temperatures prevailed west of the Rockies, following the previous week’s unprecedented heat wave. Farther east, warmth in northern New England (temperatures up to 5°F above normal) contrasted with cooler-than-normal conditions (as much as 5°F below normal) in much of the South and lower Midwest. Outside the continental U.S., highlights included a major storm (remnants of Typhoon Merbok) striking western Alaska on September 17 and Category 1 Hurricane Fiona making landfall in southwestern Puerto Rico on September 18. Early in the week, record-setting heat subsided across the West. Still, the period from September 2-11 was the hottest 10-day period on record, based on average temperature, at Los Angeles International Airport (LAX). The 10-day average temperature of 82.0°F at LAX bettered the previous mark of 80.8°F, set from September 21-30, 1978. Elsewhere in southern California, September 3-12 was the hottest 10- day period in Oxnard (average temperature of 79.7°F) and Santa Barbara (76.5°F). Oxnard’s previous record of 79.0°F had been set from September 16-25, 1939. The finale of the 1939 heat wave had a striking similarity to what happened this year, as it had ended with the arrival of a rare tropical cyclone in southern California, near San Pedro, on September 25. In 2022, Tropical Storm Kay—a former hurricane—moved within about 130 miles of San Diego, CA, on September 9 before dissipating. Farther east, a brief shot of cool air across the Plains was quickly replaced by hot weather. The week began on September 11 with daily-record lows in Kansas locations such as Garden City (41°F) and Russell (43°F). Exactly a week later, on the 18th, both Garden City (100°F) and Russell (101°F) recorded triple-digit highs. Meanwhile, consistently hot weather was largely limited to southern Florida, where daily-record highs on September 11 included 96°F in Marathon and 94°F in Miami. Marathon collected another record-setting high of 96°F on September 12, along with daily-record readings of 95°F on September 13 and 16.

 

18-24: Hot, dry weather dominated the South, with little or no rain falling from the southern Plains into the Southeast, except across Florida’s peninsula.  A late-season surge of Southwestern moisture interacted with a couple of cold fronts, generating scattered to widespread showers across the northern and western U.S. On the Plains, beneficial showers extended as far south as Kansas. Still, topsoil moisture was limited across large sections of the Plains and Northwest. 

 

Western wildfires have recently become less active, officials continued to monitor dozens of fires—collectively responsible for more than 900,000 acres of burned vegetation—in California and from the Cascades to the northern Rockies. As cooler air became more established across the North, some communities noted frost or sub-freezing temperatures. However, temperatures were generally not low enough to threaten immature summer crops, including upper Midwestern corn and soybeans. Elsewhere, weekly temperatures averaged at least 10°F above normal in scattered locations across the southeastern Plains and the mid-South. Readings broadly averaged more than 5°F above normal from the Plains to the middle and lower Mississippi Valley. Some of the coolest weather—relative to normal—covered the Sierra Nevada, where cloudiness and scattered showers suppressed temperatures.

 

During the first half of the week, temperatures soared across the central and southern Plains. From September 18-21, four consecutive tripledigit, daily-record readings occurred in Kansas locations such as Wichita (100, 101, 100, and 101°F) and Chanute (101, 102, 102, and 103°F). Record-setting heat also spread across much of the Corn Belt, where Lincoln, NE, posted consecutive daily-record highs (100 and 103°F, respectively) on September 19-20. Elsewhere in Nebraska, Grand Island (100°F on September 20) observed its second-latest triple-digit reading, behind only 100°F on September 25, 1998. In Illinois, Peoria (96°F on the 20th) experienced its fourth-hottest day of 2022, trailing 97°F on June 14 and 98°F on July 5 and 23. Paducah, KY, logged its two latest triple-digit readings, with highs of 100 and 101°F, respectively, on September 20-21. Previously, Paducah’s record had been set on September 15, 1939, with a high of 102°F. Similarly, Nashville, TN (100°F on September 21), easily set a record for its latest triple-digit heat, which had been set with a high of 100°F on September 11, 1983. In Arkansas, Fort Smith tallied a trio of daily-record highs (100, 100, and 102°F) from September 19-21. On the 21st in Mississippi, triple-digit, daily-record highs surged to 101°F in Greenville and 100°F in Tupelo and Greenwood. Late in the week, heat shifted into the western Gulf Coast region, where Waco, TX, registered a pair of daily-record highs (101°F both days) on September 22-23. Heat also briefly surged northward through the Atlantic Coast States; the 22nd featured daily-record highs of 99°F in Columbia, SC, and 98°F in RaleighDurham, NC. In southern Florida, Key West closed the week on September 23-24 with a pair of daily-record highs of 92°F.

 

25-Oct. 1: Weekly temperatures averaged at least 5 to 10°F above normal in many locations from the Pacific Coast to the High Plains. In contrast, readings generally averaged 5 to 10°F below normal from the Mississippi Valley eastward, except in southern Florida and the Northeast. Early-week warmth was most prominent across the South, where recordsetting highs for September 26 included 98°F in Shreveport, LA, and Texarkana, AR. In coastal Texas, Palacios notched a daily-record high (97°F) on September 27. Meanwhile, record-setting warmth also developed in the West. In Washington, daily-record highs on September 26 included 93°F in Dallesport and 86°F in Olympia. Farther south, record-breaking highs in California for September 27 soared to 111°F in Palm Springs and 100°F in Campo. Late-season heat also spread farther inland; daily record for the 27th reached 95°F in Boise, ID, and 92°F in Pendleton, OR. In Montana, record-setting highs for the 28th rose to 93°F in Havre and 91°F in Great Falls. On the High Plains, September 29 featured daily-record highs in locations such as Chadron, NE (94°F) and East Rapid City, SD (92°F). In stark contrast, chilly air settled southward from the Great Lakes region. On September 28, daily-record lows dipped to 23°F in Rhinelander, WI; 38°F in London, KY; and 39°F in Cape Girardeau, MO. Some of that chilly air became entangled in Hurricane Ian’s circulation, suppressing late-week temperatures in the Southeast. For example, Charleston, SC, reported highs of 65 and 64°F, respectively, on September 29-30, with Ian moving inland northeast of Charleston on the latter date. In addition, daily-record lows were established on September 30 with lows of 63°F in Florida locations such as Vero Beach and Fort Pierce. 

 

Ian’s deluge capped the wettest September on record in several Florida cities, including Orlando (22.42 inches), Sanford (21.21 inches), and Daytona Beach (19.12 inches). Downpours had arrived in southern Florida on September 27, when Key West collected a daily-record total of 4.18 inches. The next day, record-setting amounts in Florida for the 28th reached 7.72 inches in Orlando, 5.22 inches in Daytona Beach, 3.95 inches in Vero Beach, and 3.57 inches in Melbourne. The downpours lingered into September 29, when totals included 9.42 inches in Sanford, 7.91 inches in Daytona Beach, and 5.39 inches in Orlando. That marked Sanford’s wettest September day on record, surpassing Hurricane Irma’s 9.24-inch total from September 10, 2017. Saint Johns River—Florida’s longest river—rose to a record-high level on October 1 in Astor, cresting 2.41 feet above flood stage. Astor’s previous high-water mark had been established during the active hurricane season of 1933, when the river crested 2.32 feet above flood stage on October 27. Record-shattering crests were also set along many other waterways, including the Myakka River at Myakka River State Park (5.73 feet above flood stage on October 1) and the Peace River at Zolfo Springs (11.24 feet above flood stage on September 29) and Arcadia (12.65 feet above flood stage). The water level in Zolfo Springs also smashed a 1933 record (9.05 feet above flood stage). Farther north, daily-record totals for September 30 topped 5 inches in Cape Hatteras, NC (5.92 inches), and Charleston, SC (5.57 inches)—and exceeded 3 inches in North Myrtle Beach, SC (3.41 inches), and RaleighDurham, NC (3.35 inches). By October 1, daily-record amounts of 2 inches or greater occurred in West Virginia locations such as Beckley (2.29 inches) and Parkersburg (2.06 inches). Farther west, mid- to lateweek showers delivered much-needed rain across parts of the northern Plains and Northwest. In Washington, daily-record totals for September 29 included 1.25 inches in Pullman and 0.46 inch in Spokane. A day later in Montana, record-setting amounts for the 30th reached 1.34 inches in Great Falls and 1.14 inches in Lewistown.

 

 

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