NATIONAL STORM SUMMARY

MARCH 2019

3-9: Multiple storms delivered widespread precipitation across the country, with the highest weekly totals occurring in California and the interior Southeast.  East of the Rockies, the week began and ended with powerful storms in progress.  During the passage of the early-week storm, on March 3, the nation’s first major severe weather outbreak included a deadly tornado, with 23 fatalities reported in Lee County, AL.  Later, heavy, wind-driven snow blanketed parts of the northern Plains and upper Midwest. Snow continued to accumulate from the Sierra Nevada to the central Rockies, further easing any remaining drought and maintaining prospects for abundant spring and summer runoff. According to the California Department of Water Resources, the average water equivalency of the Sierra Nevada snowpack climbed to 43 inches by March 9, more than 160 percent of average.  On March 6, heavy precipitation fell across southern California, resulting in daily-record totals in locations such as downtown Los Angeles (1.25 inches) and Lancaster (0.75 inch).  Farther inland, daily precipitation records were also set on March 9 in Desert Rock, NV (1.18 inches); Death Valley, CA (0.84 inch); and Cedar City, UT (0.70 inch).  Enough cold air persisted in the Northwest to result in periods of snow.  Daily-record snowfall totals included 0.5 inch (on March 6) in Portland, OR; 1.0 inch (on March 7) in Lewiston, ID; and 1.6 inches (on March 8) in Pocatello, ID.  Farther east, the week began with snow falling in the nation’s mid-section; record-setting totals for March 3 included 3.2 inches in Dodge City, KS, and 2.2 inches in Columbia, MO.  On March 4 in the Northeast, record setting snowfall amounts reached 6.0 inches in Bridgeport, CT, and 2.3 inches at New York’s LaGuardia Airport.  Farther south, a rash of severe thunderstorms on March 3 spawned several dozen tornadoes across Alabama, Georgia, South Carolina, and northern Florida.  The fatal tornado in Alabama touched down in Macon County and later crossed Lee County, as well as Muscogee, Harris, and Talbot Counties in Georgia.  The EF-4 tornado’s five-county rampage spanned 68.8 miles in 76 minutes, with a maximum width of nearly a mile (1,600 yards).  At week’s end, a new storm system produced more than a dozen tornadoes across a six-state area from northeastern Texas to northern Alabama.  Daily-record rainfall totals for March 9 included 1.74 inches in Peoria, IL; 1.41 inches in Crossville, TN; and 1.09 inches in Columbia, MO.  On the same date, record-setting snowfall totals reached 9.5 inches in Bismarck, ND, and 9.3 inches in Aberdeen, SD.  Elsewhere in South Dakota on the 9th, wind gusts were clocked to 41 mph in Sisseton and Mobridge, while snowfall totaled 9.0 and 8.9 inches, respectively.

 

10-16: A powerful storm system emerged from the Southwest on March 13 but began to weaken while crossing the Great Lakes region by March 15.  At mid-week, blizzard conditions engulfed the central High Plains, later spreading into portions of the Dakotas, while melting snow and heavy rain falling on still-frozen soils contributed to major flooding in the western Corn Belt.  Rivers in several upper Midwestern communities crested between March 14 and 16 at record-high levels.  Farther south, beneficial rain dampened the southern Plains,  where drought has begun to develop in recent weeks.  However, a high-wind event quickly followed the rain, leading to blowing dust across southern sections of the Rockies and Plains.  Elsewhere, the mid- to late-week storm also sparked severe thunderstorms, including isolated tornadoes, across the South and Midwest.

Early in the week, periods of precipitation affected the West.  Ely, NV, received 9.0 inches of snow from March 10-12, aided by a daily-record sum of 4.6 inches on the 10th.  From March 11-13, Alamosa, CO, netted precipitation totaling 0.86 inch, including 5.0 inches of snow.  By mid-week, rapidly deteriorating conditions on the central High Plains featured high winds and heavy snow.  In Colorado, hurricane-force wind gusts were clocked on March 13 in locations such as Colorado Springs (96 mph), La Junta (88 mph), Lamar (82 mph), Denver (80 mph), and Pueblo (78 mph).  In the history of the Denver International Airport (DIA), which opened in the mid-1990s, this was the second-highest wind speed, behind a thunderstorm-induced gust of 97 mph on June 18, 2013.  DIA also set a station barometric low pressure record of 979.0 millibars, previously set with 979.9 millibars on February 25, 1998.  Elsewhere in Colorado, a pressure of 970.4 millibars was recorded in Lamar.  Denver measured 7.1 inches of snow on March 13, but higher totals were observed on the same date in Wyoming and western Nebraska.  Daily-record snowfall included 14.0 inches in Cheyenne, WY, and 12.0 inches in Scottsbluff, NE.  Casper, WY, recorded 13.6 inches on 13th, marking its second snowiest March day behind 14.6 inches on March 18, 1954.  Elsewhere on the 13th, daily-record precipitation totals approached 2 inches in locations such as Sioux Falls, SD (1.91 inches); Mitchell, SD (1.82 inches); and Grand Island, NE (1.73 inches).  For Grand Island, it was the second-wettest March day on record, behind 1.98 inches on March 21, 1979.  Heavy precipitation persisted in parts of the Midwest through March 14, when daily-record totals reached 2.74 inches in Evansville, IN, and 1.53 inches in Muskegon, MI.  Record flooding developed by March 14 in the middle Missouri Valley.  In Sioux Falls, SD, crest records from June 1957 were broken on March 14 along Skunk Creek (6.57 feet above flood stage) and the Big Sioux River (8.94 feet above flood stage).  Crest records were also broken on March 14 at Iowa gauge sites such as the Little Sioux River at Cherokee (11.40 feet above flood stage); the Ocheyedan River near Spencer (6.75 feet above flood stage); and the Boyer River near Logan (4.46 feet above flood stage).  Previous records had been set in May 2013, June 1953, and March 1965, respectively.  In Nebraska, crest records were established along portions of the Niobrara, Elkhorn, Loup, and Platte Rivers, as well as numerous tributaries.  In Waterloo, NE, the Elkhorn River crested 10.63 feet above flood stage on March 16, exceeding the March 1962 record by 5.51 feet.  On the Platte River in Nebraska, crest records (4.36 to 4.75 feet above flood stage) were set on March 15-16 from Leshara downstream to Louisville.  On March 16, the Missouri River crest passed Plattsmouth, Nebraska City, and Brownville, NE, ranging from 11.73 to 14.62 feet above flood stage and eclipsing June 2011 high-water marks.  Record flooding occurred as far east as southern Wisconsin, where the Pecatonica River at Martintown edged a July 1990 standard by cresting 8.91 feet above flood stage on March 16.

 

17-23: A week after an intense low-pressure system sparked record flooding in the Plains, a much more tranquil weather pattern covered much of the country.  However, a pair of storm systems—in the East and West, respectively—delivered heavy precipitation in a few areas.  The Eastern storm sparked heavy showers in southern Florida before intensifying along the middle and northern Atlantic Coast.  Storm-total rainfall of 1 to 3 inches or more resulted in so me local flooding in the mid-Atlantic.  Meanwhile, heavy precipitation also fell in parts of northern and central California and the Great Basin.  Well-above-normal snowpack remained in place from the Sierra Nevada to the central Rockies, but below-average snowpack was a concern in a few northern basins, mainly in the northern Cascades.  In McAllen, TX, measurable rain fell each day from March 1520, totaling 0.90 inch.  Farther east, the bulk of southern Florida’s rain fell on March 19, when Key West reported a daily-record sum of 1.60 inches.  Two days later, a developing coastal storm produced heavy rain in the mid-Atlantic.  Record-setting rainfall totals in Virginia for March 21 included 2.69 inches at Dulles Airport and 1.88 inches in Lynchburg.  On the 21st in Pennsylvania, totals of 1.41 inches in Reading and 1.34 inches in Mt. Pocono were records for the date.  On March 22-23, snow blanketed portions of the Northeast, where totals included 6.7 inches in Burlington, VT; 3.1 inches in Syracuse, NY; 3.0 inches in Worcester, MA; and 1.0 inch in Scranton, PA.  A few 1- to 2foot snowfall amounts occurred in the mountains of northern New England.  Mt. Washington, NH, New England’s highest peak, received 18.8 inches of snow on March 22-23.  Meanwhile, mild, mostly sunny weather melted snow across the northern Plains and the Northwest.  In Washington, Spokane’s snow depth decreased to a trace on March 23, down from 16 inches just 10 days earlier.  During the same 10-day period, the snow depth in Helena, MT, decreased from 16 to 8 inches.  Farther south, however, late-week precipitation spread eastward from northern California.  In Nevada, daily-record precipitation totals reached 0.86 inch (on March 21) in Ely and 0.56 inch (on March 23) in Tonopah.  Through the 23rd, Ely’s month-to-date precipitation rose to 3.30 inches (485 percent of normal), marking the wettest March in that location since 1894.

 

24-30: Warmth arrived across the northern Plains and upper Midwest, but favorably dry weather allowed runoff from melting snow to enter already swollen creeks and rivers without further complications. Farther south, however, at least an inch of rain soaked many areas from the east-central Plains into the eastern Plains. Some of the rain, which mainly occurred from March 28-30, fell on areas still recovering from mid-March flooding. Meanwhile, late-week snow blanketed western Nebraska and environs, while precipitation changed to snow in parts of the Corn Belt. By daybreak on March 31, snow depths included 2 inches in Cleveland, OH, and an inch in Indiana locations such as Fort Wayne and Indianapolis. Weekly precipitation totaled 2 to 4 inches or more in portions of northern California. Near- or above normal temperatures covered much of the country, with pockets of cooler-than-normal conditions mostly limited to northern California and New England. . The average water content of the Sierra Nevada snowpack climbed to 45 inches by the end of March, approximately 160 percent of the normal peak value. This year’s peak was similar to the final 2016-17 value of 46 inches, according to the California Department of Water Resources, and far above the 2017-18 seasonal peak of 16 inches. During the last week of March, daily precipitation records in the West included 0.57 inch (on March 27) in Stanley, ID, and 0.65 inch (on March 28) in Stanford, MT. Stanford also received 6.2 inches of snow on March 28-29. During the same 2-day period, Salt Lake City, UT, reported 4.6 inches of snow and precipitation totaling 1.60 inches. On March 29, North Platte, NE, noted impressive precipitation and snowfall totals of 1.03 and 8.1 inches, respectively. Toward week’s end, showers and thunderstorms swept across the southern and eastern Corn Belt. In Ohio, record setting rainfall totals for March 30 reached 2.00 inches in Cincinnati and 1.97 inches in Columbus. Elsewhere, significant rain fell in parts of southern Texas on March 26 and 31. Harlingen, TX, reported daily-record amounts on both days, totaling 1.02 and 1.76 inches, respectively.

 

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