Nationwide
[inline_image file=”71f786cbf3d48ca73474806c9e3c32d8.png” caption=”20220510_usdm.png”]
This U.S. Drought Monitor (USDM) week saw continued improvements on the map across the Pacific Northwest and the northern Plains in response to another round of unsettled weather during the past week.
In the Pacific Northwest, Northern California, and the northern half of the Intermountain West, a series of disturbances starting last weekend brought cold temperatures and significant snowfall accumulations to the higher elevations of the Cascades, Klamath Mountains, Sierra Nevada, ranges of the northern Great Basin, and the Northern Rockies. Storm totals ranged from 6 to 18+ inches, providing a much-needed boost to mountain snowpack levels. In addition to the late-season snowfall, temperatures plummeted well below normal levels. Minimum temperatures dipped into the teens in the Sierra Nevada as well as across areas of the Intermountain West, including Peter Sinks, Utah (the Bear River Mountains of northern Utah), which registered the national low of 7 deg F on May 11, according to the National Weather Service Weather Prediction Center. In Northern California, recent storms and cooler temperatures helped to temporarily delay further deterioration of the already shallow snowpack, which was only 22 percent of normal statewide on May 11.
In the Southwest, unseasonably warm, dry, and windy conditions exacerbated fire-weather conditions where nine large fires are currently impacting the region, including the Hermits Peak Fire, which has scorched ~204,000 acres (43 percent contained) in the southern Sangre de Cristo Range, northeast of Santa Fe, New Mexico. In the northern and central Plains, isolated showers and thunderstorm activity led to modest improvements in drought-related conditions.
Meanwhile, in the southern Plains and Texas, the first heat wave of the season brought 90 to 110+ deg F temperatures to the region as well as periods of critical fire weather conditions. In eastern portions of the southern Plains, isolated heavy rainfall accumulations (3 to 8+ inches) helped ease drought conditions. However, drought-stricken areas of western Kansas and Oklahoma largely missed out on recent storm events. In the Midwest, light to moderate rainfall accumulations (1 to 5 inches) was observed in the southern and western portion of the region this week, with most of the region remaining drought-free.
[inline_image file=”364eab67791961e13c26702b39288fb6.png” caption=”Pasture May 15 2022.PNG”]
In the Mid-Atlantic, rainfall accumulations ranging from 2 to 4 inches across areas of Pennsylvania, Maryland, northern Virginia, and West Virginia boosted area streamflows and helped to improve drought-related conditions on the map. In the Southeast, short-term dryness during the past 30 to 90 days led to minor degradations in the Lower Savannah River Basin along the Georgia-South Carolina border. Another round of isolated storms in southern Florida led to improvements in drought-affected areas.
The West
[inline_image file=”620f819ada209c53e0dc3254995224f8.png” caption=”20220510_west_text.png”]
Another round of Pacific storms impacted northern portions of the region with beneficial late-season snowfall observed in the Cascades, Klamath Mountains, Sierra Nevada, ranges of the northern Great Basin, and the central and northern Rockies. In response, improvements were made on the map in Oregon, Washington, Idaho, and Montana.
In Northern California, precipitation has been above average during the past 30-day period. However, the recent precipitation did little to make up for significant shortfalls observed since January 1 as well as in the broader longer-term context with 20+ inch precipitation deficits across Northern California during the past 24-month period. According to National Oceanic and Atmospheric Association’s (NOAA) National Centers for Environmental Information (NCEI) statewide climatological rankings, the January-April 2022 period was the driest (-9.7-inch deficit) on record for California, while the last 24-month period (May 2020-April 2022) was the 2nd driest on record.
[inline_image file=”ec51c556735bc17e7947b1291248d363.png” caption=”20220510_nv_text.png”]
Looking at the latest region-level (2-digit HUC) snowpack data across the West, the NRCS SNOTEL network (May 10) was reporting the following median SWE levels: Pacific Northwest 124 percent, Missouri 96 percent, Souris-Red-Rainy 113 percent, California 68 percent, Great Basin 61 percent, Upper Colorado 66 percent, Arkansas-White-Red 30 percent, Lower Colorado 10 percent, and Rio Grande 18 percent. According to NRCS National Water and Climate Center’s reservoir summary report (May 1), statewide reservoir storage levels remained below average across all western states, with exception of Washington state. According to the Colorado River Basin, Lake Powell was at 24 percent of capacity in the Colorado River Basin and Lake Mead at 30 percent of capacity on May 10, according to the USBR. In the Rio Grande Basin, New Mexico’s Elephant Butte Reservoir was 13 percent full, and Caballo Reservoir was 10 percent full. In Arizona, the Salt River system was 76 percent full while the Verde system was 33 percent full, with the total system at 71 percent full?down 2 percent from a year ago, according to the Salt River Project.
Looking at region-level climatological rankings, the West Climate Region (California and Nevada) logged its driest January-April period while the Southwest Climate Region (4-Corners states) observed its 3rd driest. Longer-term, the May 2020-April 2022 period was the driest on record for the Southwest Climate Region and the 2nd driest for the West Climate Region.
The High Plains
[inline_image file=”69ee47bcc5ae899cddab859070a00bde.png” caption=”20220510_high_plains_text.png”]
On this week’s map, improvement in drought conditions continued on the map in areas of eastern Kansas, Nebraska and eastern South Dakota, where another round of storms helped to alleviate short-term deficits as well as provide a modest boost to soil moisture levels and streamflows.
However, the longer-term impacts of the drought in western portions of the region are still causing impacts, including areas with poor pasture and rangeland conditions and low stock pond levels. In eastern Colorado, conditions degraded in response to continued dryness over the past several months with reports of little new growth of grasses, blowing sand and dust, and very dry soils as well as crops being abandoned in some areas, according to the Colorado Climate Center. For the week, average temperatures were above normal across most of the region, with positive departures ranging from 2 to 8+ deg F and the greatest departures observed in eastern portions of Colorado and Montana.
According to NOAA NCEI, North Dakota logged its 2nd wettest (+2.3-inch anomaly) April on record (as evidenced by severe flooding observed in eastern portions of the state). Likewise, precipitation in South Dakota and Montana was also above normal (32nd wettest) for April. In contrast, April was very dry, with Kansas seeing its 3rd driest and Colorado its 5th driest on record.
The South
[inline_image file=”39198753d8b67f8536bc6eb2bd7151d1.png” caption=”20220510_south_text.png”]
In the South, drought-related conditions improved in eastern Oklahoma and areas of northeastern Texas. In eastern Oklahoma, very heavy rainfall accumulations (ranging from 3 to 8+ inches) led to improvements on the map. However, this week’s heavy rains largely missed the western part of the state.
[inline_image file=”06d3636a0b186434feab487e532f6588.png” caption=”20220510_tx_text.png”]
Likewise, much of the western half of Texas was very dry combined with extreme heat, leading to further expansion of areas of Extreme Drought (D3) and Exceptional Drought (D4). Average temperatures across the region were well above normal. The most extreme heat was observed across Texas (6 to 10+ deg F above normal), with high temperatures soaring over 110 deg F in the Trans-Pecos region. Since last Tuesday (May 3), Big Bend Village (Big Bend National Park) logged the national high temperature six out of the seven days, with highs ranging from 102 to 112 deg F.
Likewise, the heat wave that impacted much of the region saw temperatures rise above 100 deg in the southern Plains. The excessive heat this week continued to dry out already parched soils across much of Texas and in western Oklahoma, where negative soil moisture anomalies (20th percentile) showed up on various soil moisture models. Moreover, 7-day streamflows at numerous gaging stations across the Hill Country of Texas and southwestern Oklahoma dipped below the 10th percentile, according to the U.S. Geological Survey.
Also notable, Oklahoma saw its windiest April on record (1994-present) statewide, according to the Oklahoma Mesonet. According to NOAA NCEI, average temperatures were above normal across Texas, Oklahoma, and Louisiana, with Texas logging its 11th warmest (+4 deg F anomaly) April on record. — UNL Drought Monitor
[inline_image file=”80d1183900f22a9bfc5d3549fa366f48.png” caption=”GRACE_GWS_20220509.png”]
[inline_image file=”20d6664661ce3f2cb9e4796e09b3ccf9.png” caption=”610prcp.new (33).gif”]
[inline_image file=”28efdad95e935212c0687054e66a6de0.png” caption=”610temp.new (35).gif”]
