Summer heat fades as days grow shorter

Shaun Evertson
Posted 8/24/18

Sunshine and warmth provided beneficial growing conditions for crops and rangeland throughout most of last week and into the weekend.

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Summer heat fades as days grow shorter

Posted

KIMBALL – Sunshine and warmth provided beneficial growing conditions for crops and rangeland throughout most of last week and into the weekend. On Sunday, however, a moisture-bearing weather front arrived with cooler air temperatures and widespread rainfall.

Sunday and Monday daytime temperatures fell off by 10-15 degrees across the Panhandle and the Sunday night/ Monday morning overnight low tumbled into the 30’s across the Panhandle and into neighboring areas of northeast Colorado and southeast Wyoming.

Spring-planted crops took advantage of mid-August warmth to grow toward maturity, but cooling temperatures – expected to persist through Aug. 23 – slowed the process. If present forecasts hold it appears there will be some extended warmth and dryness through the end of the month and into September, which should aid in crop maturation.

Moisture and slightly cooler temperatures were very beneficial to pasture and rangeland. Cool season grasses were greening nicely early in the week as they began to show abundant regrowth, and downy brome and other winter annual grasses were germinating nicely and providing fresh and succulent late summer browse.

At 60 days past the summer solstice, sunrise is noticeably later these days and the sun is setting earlier.

Regional Forecast and Conditions

As of Tuesday morning, the temperature at sunrise was 50 degrees under partly cloudy skies. Winds were southerly at 17 mph, gusting to 23 mph, and the barometer was steady at 30.21 inches of mercury.

Today’s weather (Friday, Aug. 24) is expected to be sunny and warm with little chance of precipitation. Daytime temperatures are forecast to reach 86 degrees before falling off to an overnight low of 54 degrees. Saturday and Sunday are expected to see daytime high temperatures touching 87 degrees and overnight lows falling to 57 degrees. No precipitation is forecast for Saturday or Sunday.

Monday through Wednesday are expected to remain sunny and warm with daytime highs reaching about 86 degrees and overnight lows falling to about 55 degrees. No precipitation is forecast through mid-week. But a weather front could bring cooler air and some rain if upper air patterns shift slightly north.

Average air temperatures cooled across the region last week. At 13 selected stations across the Panhandle, 24-hour temperatures averaged 63.4 degrees, about 6.9 degrees cooler than the previous week. High temperature for the week was 92 degrees at Bridgeport and Scottsbluff, and the low for the week was 30 degrees at Agate 3E.

At Kimball, the Aug. 14-20 daytime high averaged 78.42 degrees, about 7 degrees cooler than the previous week. The weekly high temperature was 86 degrees on Aug. 16 – 17. Overnight lows averaged 51.71 degrees, about 3.25 degrees cooler than the previous week. The weekly low temperature was 39 degrees on Aug. 20. The weekly mean temperature at Kimball was 65.07 degrees, about 5 degrees cooler than last week, and 5 degrees cooler than the Aug. average of 70.0 degrees. The long-term average high and low temperatures at Kimball for Aug. are 85.9 and 54.2, respectively.

Eleven of 13 selected Panhandle stations reported rain over the Aug. 14-20 period, ranging from 0.01 inches at Harrisburg 12WNW to 0.63 inches at Harrison. Across the Panhandle rainfall averaged 0.20 inches, compared to 0.20 inches last week.
Soil temperatures were generally higher across the Panhandle over the period: (this week/last week/change): Alliance 72.8/76.0 (-3.2) degrees; Gordon 71.6/76.0 (-4.4) degrees; Mitchell 77.5/80.2 (-2.7) degrees; Scottsbluff 74.0/76.0 (-2.0) degrees; and Sidney 72.7/75.2 (-2.5) degrees.

Winds near Kimball averaged west-southwesterly and occasionally breezy over the Aug. 14-20 period. Gusts for the week averaged 23.85 mph. High gust for the week was 40 mph on Aug. 18.

Weather Almanac

Here’s an overview of Aug. 24 temperature and precipitation highs, lows, and averages over the preceding 125 years at Kimball. Data is taken from the High Plains Regional Climate Center (www.hprcc.unl.edu), where you can easily find and track data for your own particular location.

Last year: Daily high temperature 88 degrees, overnight low 60 degrees, average temperature 74.0 degrees. Precipitation 0.7 inches, snowfall zero inches, snow depth zero inches.

The warmest Aug. 24 on record was 99 degrees in 1936. The coolest high temperature was 63 degrees in 1927. The coldest overnight low was 38 degrees in 1925. The warmest overnight low was 66 degrees in 1949. Over the years since 1893 the high temperature has averaged 82 degrees, the overnight low 53 degrees, the daily average 67.6 degrees, precipitation has averaged 0.04 inches, snowfall zero inches, snow depth zero inches.

The highest precipitation total was 1.54 inches liquid equivalent in 1972.

U.S. Drought Monitor

High Plains: Above-normal rains from the upper-level low reached parts of Kansas by Tuesday morning (8/14), but the rest of the region was much drier than normal, with little rainfall reported.

D0-D2 were contracted in central and southern Kansas, but the northeast part of the state was still drier than normal for the week. D2-D4 expanded in northeast Kansas, and D0-D1 were expanded in southeast Nebraska, to reflect dryness at the three- to nine-month time scale.

A weaker-than-normal monsoon, coupled with record 1-month evaporative demand due to high temperatures, have stressed vegetation and decreased streamflow in Colorado. D0 was trimmed slightly in eastern Colorado where it has been wet, but D2-D3 expanded in the northwest to central region where precipitation deficits mounted and stream levels were low. According to Aug. 12 USDA reports, 59 percent of the pasture and rangeland in Colorado was in poor to very poor condition, and 42 percent of the topsoil was short or very short of moisture; 35 percent of the pasture and rangeland in Kansas was in poor to very poor condition.

D0-D1 expanded, and D2 was introduced, in the Dakotas. As noted by the South Dakota State Climatologist, the lack of rain and high evaporation accompanying hot temperatures have taken a toll on crop conditions in the central and north central regions. Impacts include soybeans, which are in a critical time for grain fill, are flipping their leaves to reduce water use/loss, corn is turning brown and dead in places, and stock ponds are at very low levels. Statewide, according to USDA reports, 16 percent of the pasture and rangeland in South Dakota is in poor to very poor condition and 38 percent of topsoil and 39 percent of subsoil is short to very short of moisture.

West: Monsoon showers gave southern Arizona drenching rains, but most of the West was drier than normal, with no rain falling across most of the Pacific Northwest and California.

The Arizona rainfall improved the percent of normal statistics for the last one to nine  months, but there was still significant dryness at the 12-month time scale, and this region has experienced on-and-off drought for much of the last several years. D3 was pulled back in southwest Arizona, and the nearby D4 was deleted, where the heaviest rains fell.

D0 expanded in Idaho and Montana, D1 extended down the coast in northern California, D1 expanded in Idaho, D1-D2 expanded in Oregon, and D3 was introduced in southwest Oregon. Decreasing streamflow and reservoir storage, and increased fuel load (for wildfires) caused by unusually warm temperatures, increased drought stress in western Idaho.

In Oregon, during years with poor winter snowpack and hot and drier-than-normal summers, the water systems for the smaller communities are stressed and run out of water. These water systems are stretched even in good years. As noted by the Oregon State Climate Office, a town in Baker County is running out of water and imposing fines on watering, and getting water shipped in. According to Aug. 12 USDA reports, 63 percent of the pasture and rangeland in Oregon was in poor to very poor condition, and 90 percent of the topsoil and 88 percent of the subsoil was short or very short of moisture (dry to very dry); in southwestern Oregon, many ranchers reported pastures one half of normal production, creeks dried up and several were reported at lower levels than observed in previous drought years. As noted by the NDMC, the dry summer in the Pleasant Hill, Oregon, area has taken a toll on saplings and prevented even mature Christmas trees from growing much.

Washington residents reported unusually high numbers of dead and dying Douglas-fir trees to the Washington State Department of Natural Resources this spring and summer as drought and bark beetles ravaged the trees; and water restrictions or water shortages were reported in eastern and northern Utah and northwestern Oregon.

According to the National Interagency Fire Center, over 100 large wildfires were burning across the U.S. on Aug. 13. These were concentrated in the West, especially northern California to southwestern Oregon, Arizona, western Colorado to northeast Utah, northern Oregon to central Washington, and western Montana into adjacent Idaho.

According to Aug. 12 USDA reports, 65 percent of the pasture and rangeland in Washington was in poor to very poor condition, and 90 percent of the topsoil was short or very short of moisture; 27 percent of the pasture and rangeland in Idaho was in poor to very poor condition, and 72 percent of the topsoil and 67 percent of the subsoil was short or very short of moisture; 63 percent of the pasture and rangeland in Montana was in poor to very poor condition, and 90 percent of the topsoil and 56 percent of the subsoil was short or very short of moisture; 61 percent of the pasture and rangeland in New Mexico was in poor to very poor condition, and 74 percent of the topsoil and 77 percent of the subsoil was short or very short of moisture; 47 percent of the pasture and rangeland in Utah was in poor to very poor condition, and 68 percent of the topsoil was short or very short of moisture; 30 percent of the pasture and rangeland in Nevada was in poor to very poor condition, and 65 percent of the topsoil and 60 percent of the subsoil was short or very short of moisture; 35 percent of the pasture and rangeland in California was in poor to very poor condition, and 70 percent of the topsoil and 70 percent of the subsoil was short or very short of moisture; 98 percent of the pasture and rangeland in Arizona was in poor to very poor condition. The rains this week improved pastures and rangeland to 88 percent poor to very poor.

Near-term forecast: The Climate Prediction Center, through the end of August odds favor below-normal precipitation across the Pacific Northwest to northern Plains, and above-normal precipitation for the Southwest to Southeast, Ohio Valley to Great Lakes, Northeast, and most of Alaska.

There is a higher probability for warmer-than-normal temperatures in the West, along the Gulf of Mexico coast, along the East Coast, and in much of Alaska, while cooler-than-normal temperatures are favored to dominate the Plains to Midwest.

D-Categories

D0: Abnormally Dry, showing dryness but not yet in drought or recovering from drought.

D1: Moderate Drought

D2: Severe Drought

D3: Extreme Drought

D4: Exceptional Drought

For more information on the U.S. Drought Monitor visit: http://droughtmonitor.unl.edu 

U.S. Conditions and Weather Report

Showers soaked a large area of the country, especially along and southeast of a line from the central Plains into the Northeast. Some of the heaviest rain, locally four inches or more, fell across the southeastern Plains and environs, slowing fieldwork but generally benefiting pastures and immature summer crops.

In contrast, hot, mostly dry weather dominated the northern Plains for much of the week, promoting small grain harvesting but depleting topsoil moisture in advance of the winter wheat planting season. However, late-week showers locally helped to reverse the northern Plains’ drying trend.

Late-summer heat also covered much of the West, where weekly temperatures averaged at least five degrees above normal in many locations. In addition, dozens of wildfires remained active across northern California and the Northwest, resulting in degraded air quality due to widespread smoke.

Western showers associated with the monsoon circulation were mostly limited to the Four Corners States and portions of the Great Basin. A few thundershowers reached the Northwest but contained little rainfall and resulted in some new, lightning sparked fires.

USDA Weekly Weather and Crop Reports

Colorado

In Colorado harvest of mature crops progressed last week between precipitation events.

Northeastern county reporters noted limited rain last week allowed producers good field access. Harvest of corn silage and hay continued. Pasture and livestock were reportedly in very good condition in areas that received recent moisture. A reporter in Morgan county noted crops and rangeland continued to show drought stress or failure in drier areas. Livestock producers remained concerned regarding short feed supplies and rangeland conditions that deteriorated due to lack of moisture in areas.

East central counties received varying amounts of precipitation last week. Reporters noted drier areas were still in need of moisture to support maturing crops and rangeland condition. Barley harvest progressed in the San Luis Valley last week, but was hindered by isolated precipitation. Reporters noted mold or sprout damage to barley was a concern due to rain. Potato harvest also started last week and second cutting of alfalfa was winding down.

In southwestern counties, limited precipitation continued to exacerbate exceptional drought conditions and rangeland fires.

Southeastern county reporters noted last week was mainly dry with spotty rain showers. Crop conditions were noted to be improving with recent moisture, but some areas remained dry.

Statewide, stored feed supplies were rated 3 percent very short, 19 percent short, 74 percent adequate, and 4 percent surplus.

Sheep death loss was 2 percent heavy, 60 percent average, and 38 percent light. Cattle death loss was 1 percent heavy, 65 percent average, and 34 percent light.


Nebraska

No report published since mid-May.

Wyoming

Wyoming experienced below normal temperatures for the week. Seventeen of 33 reporting stations reported below normal temperatures for the week with a high temperature of 102 degrees recorded at Kaycee and a low of 34 degrees recorded at Yellowstone.

Above normal moisture was reported at 20 of 34 reporting stations. Three reporting stations had no precipitation. Cheyenne reported the most moisture with 1.93 inches.

A reporter from North Central Wyoming noted that crops and livestock seem to be doing well, although the smoky conditions may be a hazard for breathing.

A reporter from Western Wyoming reported that the week was hot and dry with cool nights. They also reported that the rangelands are primed for fire. Another reporter from Western Wyoming stated that they had not received rain for some time.

A reporter from Southwestern Wyoming indicated the weather was hot and dry and the irrigation water is about gone.

A reporter from South Central Wyoming indicated that they had had a hot week with hay harvest underway. They also indicated that dry pastures and stock water availability have become issues.

A reporter from Southeastern Wyoming indicated that late summer conditions persist.

Irrigation water supply across Wyoming was rated 1 percent poor, 6 percent fair, 88 percent good, and 5 percent excellent.