NATIONAL WEATHER SUMMARY

APRIL 2020

 

1-4: Generally dry weather prevailed throughout the week in southern Florida, the eastern Corn Belt, and a broad area covering southern California, the Southwest, and the central and southern High Plains. Developing drought in Florida maintained heavy irrigation demands and an elevated threat of wildfires. Elsewhere, below normal temperatures affected the Northwest and large sections of the Plains, while warmer-than-normal conditions dominated the East. Weekly temperatures averaged 5 to 15°F below normal in Montana and portions of neighboring states, while readings were as much as 5°F above normal across the lower Southeast. March ended amid lingering warmth in the Southeast. On March 29, daily-record highs soared to the 90-degree mark or higher in Savannah, GA (90°F); Jacksonville, FL (91°F); and Fort Myers, FL (91°F). In fact, Fort Myers reached or exceeded 90°F on March 14, 18-20, and 26-30, setting a March record. Previously, Fort Myers’ record of 4 days with 90-degre heat in March had been set in 1929, 1944, and 1949. Similarly, Jacksonville, FL, set a March record with 5 days of 90-degree heat (previously, 4 days in 1907). On the last day of March, monthly records were tied in Florida locations such as Vero Beach and Fort Pierce with highs of 93°F. Cooler air arrived across the Southeast in early April, while winter-like weather overspread the northern Plains and parts of the West. On April 2-3, consecutive daily record lows were set in Miles City, MT (6 and 2°F), and Worland, WY (6 and 2°F). Miles City’s low of 2°F also broke a monthly record, previously achieved with a reading of 4°F on April 1, 2014.  Elsewhere in Montana, Havre notched a daily-record low of -12°F on April 2, the day after a 3.5-inch snowfall. In Washington, daily-record lows for April 2 included 20°F in Yakima and 27°F in Wenatchee. On April 3, sub-zero, daily-record lows plunged to -5°F in Casper, WY, and -1°F in Rapid City, SD. With a low of -5°F on April 4, Grand Forks, ND, also tallied a sub-zero, daily-record low.

 

5-11: Mild weather prevailed for much of the week. In fact, temperatures averaged as much as 10ºF above normal on the central and southern High Plains and were more than 5ºF above normal across much of the South and portions of the interior Northwest.  As the week ended, an initial surge of cool air resulted in freezes on April 10-11 as far south as the central Plains the Mid-Atlantic States. 

Measurable rain fell each day from April 5-10 in southern California locations such as Carlsbad and Oceanside, totaling 6.18 and 4.76 inches, respectively. San Diego, which received 3.59 inches of rain from April 5-11, has already experienced its third-wettest April, behind 5.37 inches in 1926 and 3.71 inches in 1988. Elsewhere in southern California, April rainfall records have already been set in Ramona (4.04 inches; previously, 3.65 inches in 1988); Barstow Daggett (2.21 inches; previously, 1.83 inches in 1965); and Thermal (0.72 inch; previously, 0.50 inch in 1975). April 6 featured daily record amounts in several California communities, including Ontario (1.66 inches) and Riverside (0.99 inch). April 10 was an exceptionally wet day in Carlsbad (2.88 inches), Oceanside (2.16 inches), and Ramona (1.97 inches). Prior to reaching southern California, locally heavy precipitation fell farther north. For example, early-week, daily-record precipitation totals included 1.28 inches (on April 5) in Mount Shasta City, CA, and 1.02 inches (on April 6) in Idaho Falls, ID. Reno, NV, reported a daily-record snowfall (1.3 inches) on April 6. Farther east, the Red River (of the North) at Oslo, MN, crested approximately 11.98 feet above flood stage on April 11—the fouth-highest level on record but just 0.39 foot below the April 2009 high-water mark. By April 8, locally heavy showers swept across the eastern Corn Belt, where Dayton, OH, netted a daily-record rainfall (1.31 inches) for April 8. Precipitation also overspread the Intermountain West, resulting in a daily-record sum (0.56 inch on April 9) in St. George, UT. Meanwhile, heavy snow in northern New England on April 9-10 totaled 13.3 inches in Caribou, ME, aided by a daily-record sum of 10.9 inches on the latter date. At week’s end, wintry weather overspread Montana and environs. On April 11, daily-record snowfall amounts in Montana included 5.4 inches in Great Falls; 3.3 inches in Havre; and 2.8 inches in Helena.

Daily-record lows on Sunday, April 12, plunged to -3ºF in Great Falls and 2ºF in Cut Bank. At the time of Great Falls’ sub-zero reading, the snow depth stood at 4 inches. Earlier, however, warmth had surged northward across the Plains and Midwest. On April 7, for example, daily-record highs soared to 90ºF in Borger, TX, and Concordia, KS. Other record-setting highs for the 7th included 94ºF in McAlester, OK; 86ºF in Grand Island, NE; and 83ºF in Des Moines, IA. McAlester also notched a daily-record high (95ºF) on April 8. Daily-record highs also reached or exceeded the 90- degree mark on April 8 in Dallas-Fort Worth, TX (97ºF); Fort Smith, AR (93ºF), Chanute, KS (90ºF), and St. Louis, MO (90ºF). In Illinois, daily-record highs on the 8th rose to 87ºF in Springfield and 85ºF in Lincoln. After mid-week, warmth largely retreated into the South. From April 7-9, New Orleans, LA, tallied a trio of daily-record highs (88, 88, and 90ºF). Similarly, Miami, FL, collected three daily records in a row (92, 94, and 95ºF) from April 8-10. Toward week’s end, warmth arrived across parts of northern California and the Northwest, where daily-record highs included 81ºF (on April 9) in Montague, CA, and 80ºF (on April 10) in Yakima, WA. In contrast, an initial surge of colder air resulted in daily-record lows on April 10 in Norfolk, NE (17ºF), and Sioux City, IA (18ºF). Lincoln, NE, logged a daily-record low of 17ºF on April 10, just 3 days after posting a daily-record high of 87ºF.

12-18: A sharp, mid-April cold snap engulfed much of the country, holding weekly temperatures 10 to 20°F below normal across the Plains and Midwest and resulting in multiple freezes as far south as Texas’ northern panhandle and the Tennessee Valley. Meanwhile, temperatures plunged below 10°F on the High Plains as far south as northeastern Colorado and western Nebraska. 

In Montana, daily-record lows for April 12 plunged to -3ºF in Great Falls and 2ºF in Cut Bank. It was Great Falls’ latest sub-zero reading since April 21, 2008, when the low dipped to -8ºF. In northwestern Wyoming, Lake Yellowstone reported three consecutive sub-zero readings from April 12-14, including a low of -15ºF on the middle date. Cold air briefly spread into the Northwest, where record-setting lows for April 13 included 15ºF in Idaho Falls, ID, and 23ºF in Olympia, WA. On the Plains, consecutive daily-record lows occurred on April 13-14 in Great Falls (-3 and 4ºF); Denver, CO (15 and 11ºF); and Miles City, MT (11 and 12ºF). In North Dakota, daily-record lows for April 14 fell to 4ºF in Grand Forks and 6ºF in Dickinson. Similarly, sub-10ºF, daily-record lows occurred on the 14th in Nebraska locations such as Alliance (2ºF) and Chadron (9ºF). Elsewhere in Nebraska, Lincoln logged consecutive daily-record lows of 16ºF on April 14-15. With a low of 15ºF of April 14, Hastings, NE, noted its latest-ever 15-degree reading. By April 15, cold air settled across the interior South, including Kentucky, where dailyrecord lows sagged to 25ºF in Lexington and Frankfort. In Illinois, the coldest weather since March 7 affected Lincoln and Springfield, with April 16 lows plummeting to 24 and 26ºF, respectively. Toward week’s end, another surge of cold air delivered another pair of daily-record lows to Denver (19 and 12ºF, respectively, on April 16-17. Laramie, WY, also registered a pair of daily-record lows (-2 and -11ºF) on those dates. Cold air also edged farther into the South and East; late-week records fell to 24ºF (on April 17) in Williamsport, PA, and 28ºF (on April 18) in Harrison, AR. In stark contrast, heat and humidity persisted for much of the week in Florida, where monthly records were established on April 13 with highs of 97ºF in Sanford and Vero Beach. Earlier, the week had begun with a brief burst of triple-digit heat in southern Texas, where April 12 highs soared to 103ºF in Brownsville and 102ºF in McAllen.

19-25: Weekly temperatures averaged at least 5°F above normal in parts of Montana and the Pacific Coast States, including large sections of California. Farther east, early-season heat continued in Florida and returned across the remainder of the Deep South. Weekly temperatures averaged 5 to 10°F above normal across Florida’s peninsula and Deep South Texas. However, chilly conditions lingered from the middle and upper Mississippi Valley into the middle and northern Atlantic States. Temperatures averaged 5 to 10°F below normal from the Great Lakes region into the Northeast, with widespread freezes noted as far south as Ohio, Virginia, and West Virginia. Frost and freezes occurred early in the week in the Northeast, where daily record lows for April 19 included 29ºF in Harrisburg, PA, and 33ºF in Newark, NJ. A subsequent surge of cool air peaked on April 22, when daily-record lows dipped to 11ºF in Marquette, MI; 22ºF in Saginaw, MI; 28ºF in Parkersburg, WV; and 33ºF in Richmond, VA. On April 23, during a final day of record-setting cold, lows fell to 17ºF in Watertown, NY, and 26ºF in Hartford, CT. Farther south, the week began amid an early-season heatwave in southern Texas, where triple-digit, daily-record highs for April 19 soared to 102ºF in McAllen and 100ºF in Brownville. McAllen also reported highs of 100ºF or greater on April 12, 20, 23, and 24, breaking an April 1963 record with 5 days of triple-digit heat. Unusual heat also persisted in southern Florida, where Miami set a monthly record with a high of 97ºF on April 20. Previously, Miami’s highest April temperature had been 96ºF, achieved on April 30, 1971, and April 26, 2015. Elsewhere in southern Florida, Fort Lauderdale notched daily-record highs (95, 92, and 94ºF, respectively) on April 20, 21, and 24. From April 1-25, Fort Myers, FL, reported highs of 90ºF or greater on 16 days. This total tied Fort Myers’ record for the greatest number of 90-degree readings in April—16 days in 1944. Miami’s record for 90-degree days in April—previously, 9 days in 1908 and 1999—was broken, with 13 such days through the 25th. Farther west, record-setting heat developed during the mid- to late-week period across much of California, where Santa Barbara logged consecutive daily-record highs (88 and 92ºF, respectively) on April 22-23. Similarly, Burbank registered a pair of daily-record highs (94 and 99ºF, respectively) on April 23-24. Other record-setting highs in southern California on the 24th included 104ºF in Thermal and 103ºF in Palm Springs. On April 24-25, the week ended with consecutive daily-record highs in California locations such as San Diego (83ºF both days), Sacramento (93 and 91ºF), and Anaheim (99 and 97ºF). 

26-30: Chilly conditions preceded and accompanied the Eastern rain, holding weekly temperatures at least 5°F below normal in a broad area centered on the central and southern Appalachians. Meanwhile, the wettest areas of the interior South experienced several days of dry weather, allowing previously delayed planting efforts to advance. Elsewhere, scattered showers stretched from the Pacific Northwest to the northern Plains, while very warm (more than 10°F above normal in many locations), dry weather prevailed from central and southern California to the southern High Plains.

Ongoing dryness across the nation’s southwestern quadrant led to the driest April on record in Salt Lake City, UT (0.26 inch; previously, 0.45 inch in 1934 and 1981). In addition, it was the second-driest April on record in Russell, KS, where 0.40 inch fell. Russell’s driest April on record occurred in 1989, when 0.18 inch fell.

An early-season heatwave persisted for much of the week across the Southwest. From April 24-29, Yuma, AZ, posted six consecutive triple-digit readings, with highs ranging from 101 to 104°F. Alamosa, CO, registered eight consecutive daily-record highs (77, 78, 79, 80, 82, 84, 81, and 81°F) from April 26 – May 3. For many Southwestern locations, the heat peaked on April 29. With a high of 112°F on that date, Death Valley, CA, narrowly missed a monthly record (113°F) set on April 24, 1946, and April 23, 2012. Elsewhere on the 29th, monthly records were tied in Needles, CA (107°F), and Las Vegas, NV (99°F). On the last day of April, hot weather reached the High Plains, where daily-record highs in Nebraska climbed to 90°F in Chadron and 87°F in Alliance. Farther south, an initial round of heat had reached Texas on April 28, when highs soared to daily-record levels in San Angelo (105°F), Del Rio (102°F), and Midland (101°F).

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