NATIONAL WEATHER SUMMARY

AUGUST 2017

1-5: Heavy showers also dotted a broad area from the southern Rockies into the mid-South, including portions of the central and southern Plains.  The rain sparked local flooding.  Showers also occurred across the north from the Dakotas to New England.  Across the northern Plains, rain aided drought-stressed rangeland and pastures.  Midwestern rainfall was spotty, leaving pockets of drought across the western Corn Belt—despite favorable temperatures. Weekly temperatures averaged 5 to 10F below normal in a broad area centered across the eastern Plains, southwestern Corn Belt, and mid-South.  Farther west, however, hot weather dominated the Pacific Coast States, the northern Great Basin, and the northernmost Rockies.  Weekly temperatures averaged at least 10F above normal at scattered locations across northern California and the Pacific Northwest.  In addition, mostly dry weather prevailed along and northwest of a line from California to Montana. Record-setting heat in the Northwest contrasted with progressively cooler weather across the central and eastern U.S.  Early in the week, however, lingering heat in Texas led to record-setting highs for July 30 in McAllen (106°F) and San Antonio (105F).  Farther west, Medford, OR, posted a trio of daily-record highs (110, 112, and 109F) from August 1-3.  Medford’s reading of 112F represented its highest temperature since August 8, 1981, when it was 114F.  Several other Western communities, including Ukiah, CA (110, 109, and 106F); Salem, OR (101, 107, and 103F); Roseburg, OR (102, 108, and 108F); and Winnemucca, NV (104F each day), tallied three consecutive daily-record highs during the first 3 days of August.  In contrast, cool weather prevailed throughout the Plains late in the week, resulting in daily-record lows for August 4 in locations ranging from Aberdeen, SD (42F), to Amarillo, TX (58F).  Record-setting temperatures for August 5 reached into parts of the Midwest and mid-South, with lows dipping to 51F in Lincoln, IL, and Cape Girardeau, MO.  In contrast, Miami, FL, reported a low temperature of 84F on August 5, tying an all-time record most recently achieved on August 4, 1993.  Farther west, maximum temperatures on the 5th only climbed to 65F in locations such as Kansas City, MO, and Norfolk, NE.

 

6-12:  A deepening cool pattern across the central and eastern U.S. held weekly temperatures at least 5F below normal across large sections of the Plains and Midwest.  East of the Rockies, lingering heat was mostly limited to Florida’s peninsula and southern Texas.  Meanwhile, most of the Midwest received little, if any, precipitation.  Of particular concern for corn and soybeans were areas—such as large sections of Iowa and northern Missouri—that have received minimal rainfall in recent weeks.  Farther north, however, beneficial showers peppered the far upper Midwest.  Spotty but much-needed rain also dampened drought-affected areas of Nebraska and the Dakotas, but largely bypassed parched Montana.  By mid-August, more than three dozen wildfires, in various stages of containment, were burning across western Montana and the Pacific Northwest.  In the Northwest, air-quality degradations were noted due to hot, smoky, stagnant conditions.  Despite the smoke and haze, Pacific Northwestern temperatures averaged at least 5 to 10°F above normal.  Elsewhere, widely scattered, monsoon-related showers dotted the Great Basin and Intermountain West, while periods of heavier rain affected the central and southern Rockies.  In Oregon, Meacham posted consecutive daily-record highs (92 and 94F, respectively) on August 9-10.  Farther east, however, several surges of cool air resulted in scattered daily-record lows.  On August 6 in Tennessee, Knoxville’s low of 56F was a record for the date.  Later, additional daily-record lows included 39F (on August 10) in Livingston, MT, and 43F (on August 11) in Sidney, NE.  Across the Deep South, however, lingering heat and humidity led to a low of 83F in West Palm Beach, FL, on August 9.  That tied an August record for West Palm Beach’s highest minimum temperature.

 

13-19:  Warm weather returned to the Midwest, following an unusually cool start to August, boosting moisture demands for filling summer crops.  In contrast, hot, steamy weather across the South, accompanied by scattered showers and abundant soil moisture reserves. Similarly, hot, dry weather returned to the Northwest, where several fires continued to burn.  In fact, a brief lull in the Southwestern monsoon circulation led to mostly dry weather and a warming trend in many other areas of the western U.S.  Elsewhere, spotty downpours across the southern Plains and mid-South sparked local flooding but generally benefited summer crops. Temperatures rarely strayed into record-setting territory, despite a general late-week warming trend; steamy heat across the Deep South; and the return of hot weather in the Northwest.  Prior to the Northwestern heat, daily-record lows were set on August 15 in Kalispell, MT (36F), and La Grande, OR (44F).  Later, Redding, CA, posted a

daily-record high (109F) for August 17.  In contrast, cool weather lingered for much of the week across the northcentral U.S., where Huron, SD, notched a high temperature of just 69F on August 16.  Farther south, temperatures remained above the 80-degree mark for long stretches of time along and near the Gulf Coast.  From August 10-17, the lowest temperature in Galveston, TX, was 83F.  Similarly, Key West, FL, remained above 80F on 11 consecutive days from August 8-18.  Key West also notched a daily-record high (94F on August 19).  A day earlier, on August 18, Southern daily-record highs had climbed to 104F in McAllen, TX; 96F in Norfolk, VA; and 95F in Miami, FL.

 

20-26: Weekly temperatures averaged at least 5F below normal in parts of the upper Midwest.  Generally cool weather also covered portions of the Plains and Northeast.  In contrast, hot, humid weather gripped the Southeast, while late season heat prevailed across much of the West.  Mostly dry weather accompanied the Western heat.  Dry weather extended across the northern Plains, where drought impacts on rangeland and pastures continued to mount as the winter wheat planting season approached. Steamy weather in the Southeast resulted in daily-record highs in Florida locations such as Fort Myers (96°F on August 22) and Tampa (96F on August 23).  Later, Midwestern cool spells led to daily-record lows in Marquette, MI (33F on August 25), and Cape Girardeau, MO (52F on August 24).  Late in the week, however, heat began to build across the West.  By August 26, daily-record highs were established in numerous Western locations, including Death Valley, CA (122F), and Yuma, AZ (113F).  In Sacramento, CA, a string of daily-record highs (105, 108, and 110F from August 26-28) culminated in a monthly record-tying high of 110F on the 28th.  

 

27-31: Areas experiencing mostly dry weather included the western, central, and northeastern U.S.  However, briefly heavy showers dotted the Great Lakes region and a few other locations.  Ongoing dry weather brought further drought intensification to the northern High Plains and hampered wildfire containment efforts in the West.  In addition, several new fires developed from the Pacific Coast to the northern Rockies, boosting the year-to-date U.S. total to more than 7.6 million acres burned.  Weekly temperatures averaged at least 10F above normal across large sections of the Pacific Coast States, as well as portions of the northern Rockies and northern High Plains.  Several all-time temperature records were established on September 1-2 in along California’s central coast.  In contrast, temperatures averaged more than 5F below normal across large sections of the central and southern Plains; western Gulf Coast region; lower Midwest; and the Northeastern and Mid-Atlantic States. Late-month temperatures spiked in the Far West, with Sacramento, CA, tying an August 1996 record with a high of 110°F on the 28th.  Elsewhere in California, Sandberg easily broke a monthly record on August 28 with a high of 104F, surpassing 100°F on August 13, 2016, and several earlier dates.  As far east as the Intermountain West, the parade of records continued as the week progressed.  Salt Lake City, UT, collected a trio of daily-record highs (98, 98, and 99°F) from August 27-29.  August 29 also featured daily-record highs in California locations such as Death Valley (125°F); Elsinore (114°F); and Bakersfield (112°F).  In some areas, heat further intensified during the second half of the week.  Ramona, CA, registered 111°F on August 31, tying an alltime record previously set on July 22, 2006.  The first day of September featured unprecedented heat in downtown San Francisco, CA, where the high of 106F toppled the all-time record of 103F on June 14, 2000.  And, on September 2, Santa Maria, CA (106F), tied a monthly previously set in 1939.  Also in California on the 2nd, both Redding and Red Bluff posted daily-record highs of 114F, while King City achieved an all-time record of 115°F (previously, 113F on August 23 and 24, 1931, and September 2, 1955).  In stark contrast, an early-season cool spell led to consecutive daily-record lows on September 1-2 in New York locations such as Binghamton (42 and 39F) and Syracuse (42 and 40F).  Other record-setting lows for September 2 included 34F in Glens Falls, NY, and 36°F in Mount Pocono, PA.

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