Click here to go to the US Drought Monitor website. Here’s an excerpt:
Summary
This USDM week began with an upper-level trough exiting the Northeast. Another trough moved across the country during the week, dragging a low pressure system and cold front across the country and giving the Central Rockies, Central Plains, Upper Midwest, and Northeast a blanket of snow. A third trough moved across the West and into the Plains as the week ended. Precipitation for the week was above normal across parts of California, the Southwest, southern Texas, Central to Northern Rockies, Central Plains to Upper Mississippi Valley, and Northeast. Rains fell along the front from Texas to the Great Lakes, but amounts were mostly below normal. The troughs moved through a dominant upper-level ridge which kept weekly temperatures above normal for most of the contiguous U.S. (CONUS), with only Florida and the coastal Southeast averaging cooler than normal…
The Great Plains
A large blanket of snow fell across the Plains of Colorado to the Upper Mississippi Valley, with half an inch to an inch of precipitation across parts of Nebraska and the Dakotas. Coastal and northeastern Texas also received half an inch or more of rain, but the rest of the Plains was mostly dry this week. D0-D3 were adjusted in Texas, D0-D3 expanded in parts of Oklahoma, D0 expanded in North Dakota, and an oval of D1 was added to south central North Dakota. As summarized by the National Weather Service, from an agricultural perspective, farmers and ranchers across extreme northeast Texas have already had to supplement winter hay as the pastures were dormant even before the first frost/freeze this past weekend, stock ponds are very low/dried up, and right now, one rancher in western Bowie County has stated that winter wheat probably will not come up if planted now. As noted by the Oklahoma State Climatologist, reservoirs in central Oklahoma have seen significant decreases in storage, producing significant water impacts. Lake Hefner and Overholser were 6 and 5 feet down, respectively, for this time of year, and Draper was down 12 feet, which is a bit drastic…
The Rockies and Far West
The upper-level troughs brought welcomed precipitation to parts of the West, with 2 inches or more of precipitation falling along the coast from central California to Washington, and 2-4 inches in favored upslope regions further inland. The troughs left half an inch to an inch of moisture across parts of the Southwest and Central to Northern Rockies, which was above normal in these regions and in parts of California. Precipitation amounts were less than half an inch in other parts of the West, and these translated to below normal for the week. Mountain snow water content increased from 4 to 12 inches at many of the SNOTEL stations. But this is early in the snow season, so no change to the drought depiction was made in the West. The ecosystem continued to show the impacts of the multi-year drought. According to an analysis released November 18 by the U.S. Forest Service, the Forest Service estimates, based on aerial detection surveys conducted throughout 2016, the number of dead trees on California’s forested lands grew to a cumulative total of 102 million on 7.7 million acres since 2010. In 2016, 62 million trees died, representing more than a 100 percent increase in dead trees across the state from 2015, when 29 million trees died. This scale of die-off is unprecedented in California’s modern history. Millions more drought-stressed trees that are not yet dead are expected to die in the coming months and years. Five consecutive years of severe drought in California, a dramatic rise in bark beetle infestation and warmer temperatures are leading to these historic levels of tree die-off. The majority of the 102 million dead trees are located in ten counties in the southern and central Sierra Nevada region. The Forest Service also identified increasing mortality in the northern part of the state, including Siskiyou, Modoc, Plumas and Lassen counties. Dead and dying trees can pose a significant risk to communities if a wildfire breaks out in these high hazard areas…
Looking Ahead
An inch or more of precipitation is forecast to fall November 23-28 from eastern Texas to the Great Lakes as the latest front and low pressure system move across the CONUS. Three or more inches are expected from northeast Texas to eastern Arkansas, and an inch or more is progged for the Northeast. Meanwhile, another Pacific system will drench the West Coast with up to 10 inches or more of precipitation from northern California to Washington, and an inch or more as far inland as the Northern Rockies. No precipitation is forecast for southern California to southwest New Mexico, but the rest of the country may see a tenth of an inch or more. Temperatures should be warmer than normal for most of the CONUS, except for parts of the extreme Southwest. For November 28-December 6, odds favor cooler-than-normal temperatures for the West and warmer-than-normal temperatures for the East and Alaska. Much of the CONUS from the Plains to the East Coast, the Southwest, and Alaska are expected to be wetter than normal, while odds favor drier-than-normal weather across the Far West and the Rio Grande Valley.