NATIONAL STORM SUMMAY

APRIL 2023

2-8: The last in a series of winter-like storms punched inland across the West before crossing the central Plains and upper Midwest. The storm’s path dictated observed conditions, which included heavy, early-week snow across parts of the northern Plains and the West; showers and locally severe thunderstorms in the mid-South and Midwest, mainly on April 4-5; significant, late-week rain in much of the South; and dry, windy weather on the drought-stricken southern High Plains.

Snow that initially covered the ground in November 2022 remained in place across portions of the north-central U.S., with a new round of wind-driven snow falling during the first half of the week.

As April began, impressive snowfall spread inland across the West. In a 48-hour period from April 2-4, snowfall in Utah totaled 21.5 inches in Randolph and 16.6 inches in Laketown. Alta, UT, was blanketed by 63.2 inches of snow during the first 5 days of April. In Wyoming, Casper measured its greatest 1- and 2-day snowfall totals on record—26.7 and 36.0 inches, respectively, on April 3 and April 3-4. Casper’s previous records, 24.3 and 31.3 inches, had been set on December 24 and December 23-24, 1982. Elsewhere in Wyoming, daily-record snowfall totals for April 4 reached 12.5 inches in Lander and 6.0 inches in Riverton. Daily-record amounts for the 4th extended into the Dakotas, where snowfall totaled 11.0 inches in Mobridge, SD, and 6.9 inches in Grand Forks, ND. Pierre, SD, received 10.0 inches on April 4-5, accompanied by a peak wind gust to 51 mph. By April 5, rain showers overspread the Great Lakes States, resulting in dailyrecord totals in Massena, NY (1.55 inches); Alpena, MI (1.33 inches); and Cincinnati, OH (1.31 inches). The Grand River at Comstock Park, MI, crested 4.05 feet above flood stage on April 8—highest level in that location since May 2020. Subsequently, heavy rain shifted southward; April 6 totals of 4.20 inches in Lufkin, TX, and 3.07 inches in Shreveport, LA, were records for the date. Rain lingered in the western and central Gulf Coast States through April 17, when McComb, MS (3.51 inches); Baton Rouge, LA (2.83 inches); and Brownsville, TX (1.30 inches), collected daily records. At week’s end, heavy rain overspread the Southeast, resulting in daily-record totals exceeding the 2-inch mark in Birmingham, AL (2.86 inches), and New Bern, NC (2.46 inches).

9-15: Early-week showers dotted the Southeast and Pacific Northwest, resulting in daily-record totals for April 9 in Punta Gorda, FL (2.29 inches), and Quillayute, WA (1.94 inches). Miami, FL, received at least 2 inches of rain on 3 consecutive days from April 10-12, with respective totals of 2.47, 2.76, and 2.15 inches. Elsewhere in Florida, historically heavy rain on April 13 caused severe but localized flooding in Hollywood, Fort Lauderdale, and environs, with several 1- to 2-foot totals reported. Hollywood received an April 13, calendar-day total of 16.52 inches. Meanwhile in the Northwest, daily-record totals for April 10 included 1.36 inches in Salem, OR, and 0.93 inch in Ephrata, WA. Subsequently, rain overspread portions of the central and eastern U.S., although most amounts were generally light. However, Raleigh-Durham, NC, collected a daily-record sum (1.73 inches) on April 14. Meanwhile in Alabama, April 12-15 rainfall in Mobile totaled 5.09 inches. As the week ended, precipitation across the upper Midwest began to change to wet snow. By Sunday, April 16, dailyrecord snowfall totaled 7.0 inches in La Crosse, WI.

16-22: A winter-like storm delivered accumulating snow early in the week across the upper Midwest, followed by a period of unusually cold weather. Many other areas across the eastern half of the country experienced showers and thunderstorms in advance of the surge of cool air. Thunderstorms were heavy and locally severe in a few areas, especially from April 19-22, as a cold front marched across the central and eastern U.S.

Despite some brief Western warmth, the Sierra Nevada snowpack retained an average water equivalency of more than 55 inches at week’s end, according to the California Department of Water Resources. Early in the week, weather hazards included heavy rain in the Deep South and late-season snow in the upper Midwest. La Crosse, WI, received 9.5 inches of snow on April 16-17. The snow in La Crosse followed 3 consecutive days (April 12-14) with high temperatures ranging from 85 to 90°F.

In northern Minnesota, record-setting snowfall totals for April 20 reached 5.9 inches in International Falls and 3.2 inches in Duluth. International Falls logged another daily snowfall record, 2.6 inches, on April 21. Through April 22, seasonal snowfall records had already been broken in several locations, including Duluth (139.9 inches; previously, 135.4 inches in 1995-96); Rhinelander, WI (120.2 inches; previously, 116.3 inches in 2018-19); and Saint Cloud, MN (88.2 inches; previously, 87.9 inches in 1964-65). Even before the mid-April arrival of wintry weather, snow-melt flooding was underway in parts of the upper Midwest. On April 13, the Big Sioux River near Watertown, SD, achieved its third-highest level on record, cresting 1.81 feet above flood stage. It was the highest river level in that location since April 2001. Similarly, the Mississippi River at Saint Cloud, MN, rose to its third-highest level on record (0.95 foot above flood stage on April 16)— the highest crest in that city since April 2001. Farther south, the week opened with heavy rain on April 16 in southern Florida, where West Palm Beach netted a daily-record sum of 4.97 inches. Elsewhere on the 16th, thunderstorms near the mouth of the Mississippi River produced a wind gust to 76 mph in Grand Isle, LA. Later, rain spread into other parts of the eastern U.S.; record-setting totals for April 17 included 2.47 inches in Sarasota-Bradenton, FL, and 1.21 inches in Plattsburgh, NY. Meanwhile, rain and snow showers dotted the Northwest, where Boise, ID, collected a daily-record snowfall (0.9 inch) on April 18. During the mid- to late-week period, locally severe thunderstorms affected the eastern half of the U.S.

23-29: Much-needed rain fell across portions of the central and southern Plains, providing limited and localized relief to drought-stressed rangeland, pastures, and winter grains. Some of the heaviest rain, generally 1 to 3 inches, fell in southeastern Colorado, southwestern Kansas, northern and eastern Texas, and much of Oklahoma. Significant rain extended eastward across the South, eventually reaching the Atlantic Coast States.  Totals exceeding 4 inches were reported in a few spots, mainly across northeastern Texas and the middle and southern Atlantic States. Most other areas, including the Northwest, Midwest, and northern half of the Plains, received only spotty showers.

Early in the week, heavy rain drenched the Northeast. On April 23, daily-record totals topped 2 inches in Hartford, CT (3.13 inches); Concord, NH (2.46 inches); and Worcester, MA (2.02 inches). A separate area of rain in Texas resulted in record-setting totals for April 23 in Laredo (3.04 inches) and Palacios (2.12 inches). Later, a storm system arriving from the West delivered much-needed rain across the central and southern Plains. April 25-26 rainfall totaled 2.09 inches in Pueblo, CO, aided by a daily-record sum (1.40 inches) on the initial date. Similarly, April 25-26 rainfall reached 2.15 inches in Garden City, KS, and 1.12 inches in Borger, TX. Farther north, however, dry conditions prevailed. North Platte, NE, completed its driest April on record (0.04 inch, or 2 percent of normal), tying 1928. Since a major snowfall (13.9 inches) struck North Platte on January 18, precipitation has totaled 0.62 inch. During the second half of the week, two rounds of heavy rain affected portions of the southern and eastern U.S. As the first event unfolded on April 27, daily-record totals included 4.40 inches in GreenvilleSpartanburg, SC, and 4.13 inches in Pensacola, FL. Daily-record amounts topped 2 inches on the 27th in Florida locations such as Fort Pierce (2.54 inches) and Gainesville (2.45 inches). By April 28, daily-record totals included 2.06 inches in Lynchburg, VA; 1.82 inches in Baltimore, MD; and 1.59 inches in Zanesville, OH. Rain was slow to exit the Northeast, where record-setting amounts for April 29 totaled 3.05 inches in Newark, NJ, and 2.46 inches at New York’s Central Park. The last day of April featured lingering rain from the first round of storminess—Augusta, ME, received 3.00 inches—along with daily-record totals associated with the second round in locations such as Scranton, PA (3.06 inches), and Georgetown, DE (2.40 inches).

Meanwhile, snow-melt flooding continued in the upper Mississippi Basin. Along the Mississippi River, it was a top-three flood crest in locations such as La Crosse, WI (3.89 feet above flood stage on April 26), and Dubuque, IA (7.03 feet above flood stage on April 29). In those locations, higher crests occurred only in April 1965 and 2001.

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