NATIONAL WEATHER SUMMARY

 

FEBRUARY 2012

 

1^st-11^th..Wet and active weather continued in the East on Wednesday as a low pressure system from the Tennessee Valley moved east through the Mid-Atlantic. The system produced light to moderate snow showers in parts of the Ohio Valley and the Central Appalachians and a mix of rain and snow in the Mid-Atlantic. Elsewhere in the East, isolated showers formed in the southern tip of Texas and in parts of south Florida.  In the West, a weak disturbance moved over western Oregon and Washington during the morning and a weak warm front lifted slowly northward across the region during the afternoon. These systems brought some very light rain to the region ranging from a trace in some interior valleys to a tenth of an inch along the coast. Meanwhile, energy from the Northwest began to spread southeastward into the Central Great Basin this afternoon, creating chances for a few inches of snow in the mountains late this afternoon with some light rain and snow showers possible over the lower valleys.

 

12^th-18^th…Heavy rain across the Deep South provided drought relief but triggered lowland flooding. Weekly rainfall totaled at least 4 inches in many locations from Louisiana into southern Alabama and westernmost

Florida. However, only light showers dampened Florida’s peninsula, where drought continued to intensify. Meanwhile, generally light precipitation stretched from the southern Plains into the eastern Corn Belt. Gradual recovery from last year’s historic drought continued on the southern Plains, where sub-soil moisture reserves and pond and reservoir storage remained limited. Farther north, mostly dry weather prevailed across the northern Plains and the upper Midwest. Elsewhere, widespread showers dotted the West, but precipitation totals were light and resulted in little change in the developing drought situation. A series of fast-moving storms produced widespread precipitation, mainly across the South and West. Early in the week, snow blanketed parts of the West. Snow fell as far east as the southern High Plains, where Lubbock, TX (2.8 inches), received a daily-record total for February 12. Farther west, measurable snow fell daily in Ely, NV, from February 12-15, totaling 8.1 inches. Elsewhere in Nevada, daily-record snowfall amounts for February 15 included 4.5 inches in Elko and 2.8 inches in Winnemucca. Meanwhile, the average water content of the high-elevation Sierra Nevada snow pack stood at just 7 inches (33 percent of normal) on February 18, up from 6 inches at the beginning of the week. Farther east, midweek rains soaked parts of the Gulf Coast region, where Alexandria, LA (2.45 inches), netted a daily-record sum for February 15. Three days later, daily-record totals for February 18 included 3.51 inches in Lake Charles, LA, and 3.85 inches in Galveston, TX. Weekly rainfall totals climbed to 4.87 inches in Alexandria, LA; 4.75 inches in McComb, MS; 4.62 inches in Mobile, AL; and 3.89 inches in Pensacola, FL. In Louisiana, the worst lowland flooding since 2008 developed in several basins, including Bayou Cocodrie near Clearwater (2.08 feet above flood stage on February 20) and the Calcasieu River near Glenmora (3.37 feet above flood stage on February 19).

Cold weather prevailed early in the week across the East. In Florida, daily-record lows for February 12 dipped to 25F in Gainesville and 30°F in Daytona Beach. Farther north, parts of northern Maine reported lows to -20F or below on both February 13 and 14. Meanwhile in the south-central U.S., a rapid warming trend followed some early-week snow. In Texas, Austin (Bergstrom) warmed to 80F on February 15—the highest temperature there since November 21—just 3 days after a trace of snow fell. Farther west, a dry air mass settled into the West during the mid- to late-week period, resulting in windy conditions. A northerly wind gust to 79 mph was clocked at Camp Nine, Los Angeles County, CA, on February 16. On the same date, Paso Robles, CA, posted a daily record low of 26F. For the second consecutive week, mild weather prevailed in Alaska. In fact, weekly temperatures again averaged more than 20F above normal at some locations across interior Alaska. On February 13, Delta Junction posted

a daily-record high of 37F. Meanwhile, widespread precipitation covered southern Alaska, where Kodiak’s 11.4-inch weekly snowfall was boosted by a daily-record total of 4.2 inches on February 15. Heavy snow also returned to Valdez, following a 4-week lull that had allowed the snow depth to settle from 84 to 68 inches between January 12 and February 12. Weekly snowfall totaled 27.4 inches in Valdez, increasing the snow depth back to 84 inches on February 18. Through February 18, the season-to-date snowfall in Valdez stood at 370.0 inches, 158 percent of normal.

 

19^th-25^th…Near to above normal temperatures prevailed nearly nationwide, especially from the Plains to the East Coast. Despite the mild weather, snow blanketed parts of the nation’s northern tier, including parts of the northern Plains, upper Midwest, and Northeast. Farther south, weekly precipitation totaled an inch or more from the central and southern Appalachians into the southern Mid-Atlantic region. In the latter region, heavy snow fell on February 19. Later, locally severe thunderstorms accompanied additional Southeastern rain—mainly on February 24. However, rainfall largely bypassed Florida’s parched peninsula. Meanwhile, mostly dry weather stretched from California to the central and southern High Plains. Periodic high winds raised dust across the southern High Plains, primarily on February 20, 23, and 25. Elsewhere, precipitation overspread the northern half of the West, from the Pacific Northwest to the northern and central Rockies. However, high-elevation snow packs remained  substantially below late-February averages across the majority of the West, including California, Oregon, Nevada, Utah, Arizona, western Colorado, and southern Idaho. Early in the week, heavy precipitation fell in parts of the Southeast. Charleston, SC (1.26 inches on February 19), received a daily rainfall in excess of an inch for the first time since August 13, 2011. Similarly, Savannah, GA (1.29 inches), netted more than an inch for the first time since October 10, 2011. Farther north, daily-record snowfall totals for February 19 included 3.1 inches in Jackson, KY, and 1.6 inches in Greensboro, NC. It was Greensboro’s first measurable snow of the season. In Richmond, VA, the season’s first measurable snowfall totaled 4.0 inches on February 19-20. Elsewhere, February 19-20 snowfall reached 6.9 inches in Bluefield, WV, and 7.7 inches in Lynchburg, VA. A few days later, significant precipitation spread across the Northwest, where Big Sky, MT (6.5 inches on February 21), received a daily-record snowfall. February 21-22 snowfall totals of 2 to 3 feet were common across western Wyoming and neighboring areas, while high-elevation wind gusts locally topped 100 mph. farther south, Lubbock, TX (63 mph on February 20), clocked its highest wind gust since

October 17, 2011. Toward week’s end, precipitation shifted into the Midwest, South, and East. Waterloo, IA (4.1 inches), received a daily-record snowfall on February 23, followed the next day by record-setting amounts in locations such as Houghton Lake, MI (7.3 inches), and Rockford, IL (4.0 inches). On February 24, locally severe thunderstorms swept across the Southeast, where at least a half-dozen tornadoes were reported. On the same day, Augusta, GA, noted a squall line-induced wind gust to 70 mph. Farther north, locally heavy snow blanketed the Northeast, where February 25-26 snowfall reached 30 inches atop Vermont’s

Jay Peak. Warmth lingered across the southern Atlantic region on February 19, when Miami and Vero Beach, FL, posted daily-record highs of 87F. At mid-week, a new surge of warmth quickly spread from California to the southern High Plains. Daily-record highs for February 22 included 79F in Santa Rosa, CA, and 77F in Dalhart, TX. A day later, record-setting warmth lingered in the West and exploded across the South and East. Santa Rosa (80°F on February 23) notched a record for the second consecutive day. Meanwhile, monthly record highs were established on February 23 in locations such as Monroe, LA (89F; previously, 86F on February 25, 1977, and earlier dates); Monticello, AR (85F; previously, 84F on February 27, 1986, and earlier dates); and Greenwood, MS (84F; previously, 83F on February 27, 2011, and earlier dates). On February 23-24, consecutive daily-record highs were established in locations such as Stockton, CA (73F and 74F), and Charleston, SC (81F both days). Other Southeastern records for February 24 included 89°F in Vero Beach, FL; 86F in Savannah, GA; and 82°F in Norfolk, VA. Near normal temperatures across southern Alaska contrasted with a third consecutive week of above-normal readings across much of interior Alaska. Periods of heavy precipitation affected southeastern Alaska, where Pelican (2.38 inches) netted a daily-record total on February 20. Late in the week, storminess began to overspread Alaska from the southwest. As a result, February 24-26 snowfall reached 7.4 inches in McGrath and 6.8 inches in Bethel. At the same time, bitterly cold air returned to northwestern Alaska, where Kotzebue dipped to -30°F on February 25.

 

26^th-28^th…The strong storm system in the central U.S. moved northeastward through the Upper Midwest toward the Upper Great Lakes on Wednesday. This system brought heavy snow to areas from the Upper Mississippi Valley through the Northern Appalachians and into parts of the southern Northeast. In addition to snow, swaths of freezing rain and sleet with ice accumulations were possible from central Wisconsin through the northern Mid-Atlantic and southern New England states. Meanwhile, winds across the Upper Midwest picked up during the afternoon as this system deepened. This led to periods of blowing snow and reduced visibilities. A Blizzard Warning remained in effect for north-central South Dakota, while a variety of Winter Weather Advisories and Winter Storm Warnings remained in effect for areas from the eastern Northern Plains into the Upper Great Lakes and throughout the Northeast. To the south, moisture from the Gulf of Mexico interacted with the associated cold front extending from the Ohio Valley through the Southern Plains and produced rain and thunderstorms ahead of the boundary. Much of Tennessee and adjacent southern Kentucky, southwest Virginia, Western North Carolina, Northern Georgia, Northern Alabama, and Northern Mississippi were at moderate risk for severe weather activity with damaging wind gusts, hail, and possible tornadoes, while areas surrounding the moderate risk area, across the Ohio Valley southward into parts of the Lower Mississippi Valley and northern Gulf States, eastward into the southern Mid-Atlantic coastal areas remained at slight risk for severe thunderstorm development. Out West, a trough of low pressure moved across the West Coast with a strong frontal boundary and significant moisture from the Pacific. Immense onshore flow fueled rain and heavy mountain snow across parts of the Pacific Northwest and northern California. More moderate precipitation spread into central California, northern Nevada, northern Utah, and Idaho as the front pushed inland across the West.

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