The West: It was a pretty quiet week overall for much of the West, with unseasonably warm temperatures bringing on early snow melt-out in many places and very little in the way of precipitation stealing the headlines. Wyoming’s statewide snow water equivalent numbers, which were already low this year, took a major hit, dropping from 69% of average to just 44% of average. This is 22% below last year’s numbers for this week, which were also well below average. An expansion of D1, D2, and D3 is noted this week in western Wyoming and along the Idaho border as a result. Farther west, conditions this week show a worsening of the dryness and drought found in California as the dry season begins to settle in. Impressive deficits on the year (16 to 20 inches/ 50-70% of normal) in northern California have led to a pushing north of D0, D1, and D2 in the valley up toward the Cascade Range and the Oregon border. The D2 in the Sierra Nevadas has now pushed farther east and north through Nevada and up into southeast Oregon this week as well. The heat hasn’t helped matters here either, with the majority of upper elevation SNOTEL sites being snow free.
The Plains and Upper Midwest: Across the Plains, the recent rains, now coupled with good above-normal year-to-date and water year numbers, continue to lead to the erosion of D1 in eastern Montana and western North Dakota. This has also brought about the removal of D2 conditions along the U.S./Canadian border in northwestern North Dakota. More rains in the southern Plains led to the removal of the small pockets of D0 that were remaining in northeast TX and southwest TX along the Rio Grande. However, the multi-year drought has left many marks, and the southern Plains remain vulnerable to the reemergence of drought or flash droughts later this summer if the rains don’t continue in a timely manner. Missing out on this recent wetness has been the extreme southern tip along the GulfCoast, where persistent dryness on both short- and long-term time frames has led to the re-introduction of D0 in the Brownsville region and up the coast, engulfing Kingsville and Corpus Christi.
Lots of changes occurred in the Midwest this week as the high temperatures (10+ degrees above normal in many places) were felt across all of Minnesota, Wisconsin, and the Upper Peninsula of Michigan into the Houghton area. Conditions continue to worsen in these areas, with D2 expanding south and east through Wisconsin and into the Upper Peninsula, where many locales are running at about 50-75% of normal on the year. In line with the changes above, D0 has spread into southeastern Minnesota and central Wisconsin and D1 has advanced into central Wisconsin as well.
The Delta and Southeast: The dryness continues its hold over much of the Southeast, fanning fires and beginning to worsen and expand over more of the region. Precipitation departures for the year to date are running 8 to 16+ inches below normal (these values fall at, or below, 50% of normal) across large parts of Mississippi, Alabama, Tennessee, Kentucky, the western Carolinas, Georgia, and Florida. Soil moisture and streamflows are feeling the brunt of it as we head into the high demand season. The Huntsville, AL, area has recorded its lowest year-to-date precipitation amount (10.35") on record since the period of record began in 1894. Consequently, D2 and D3 have expanded to the northeast and the southwest into more of Tennessee and Mississippi, respectively. In addition, the unseasonably dry weather has brought about a D0 expansion covering most of Kentucky, southern Ohio, and western West Virginia. To the east, D1 has now pushed a bit north and east into North Carolina’s upper Yadkin and lower CapeFearRiver basins.
To the south, in just the past two weeks alone, nearly 500 fires have been reported in Florida, accounting for the burning of more than 170,000 acres as of May 14. This latest two-week total represents more than the total number of acres burned (159,407) in the state between January and the end of April. Spotty rains haven’t been enough to alleviate concerns as several of their coastal well fields are now threatened by saltwater intrusion. The South Florida Water Management District (from Lake Istokpoga and Lake Okeechobee and points southward) has Phase II and Phase III water shortage emergency conservation measures in place, limiting watering to just once or twice a week. The rainy season can’t some soon enough.
Alaska and Hawaii: Conditions remain unchanged over the existing D0 regions in both Hawaii and Alaska this week.
Looking Ahead: During the next 5 days (May 17-21), temperatures look to be well above normal over a good portion of the interior West. At the same time, the South and the eastern half (east of the Mississippi River) of the country can expect to see cooler than normal readings. Precipitation is most likely to fall over the border waters region between Minnesota and Canada, the southern Rockies, western Texas, along the coastal regions of the Gulf States, and within the Mid-Atlantic region.
The 6-10 day outlook (May 22-26) shows the likelihood of above-normal temperatures across most of interior Alaska, all of California, southern Oregon, and the western reaches of Nevada and Arizona. The warmth will be shared by those in the Great Lakes region and into the Northeast. Cooler weather is expected in the northern Rockies region and across most of the Great Plains. In terms of precipitation, interior Alaska looks to be dry, although the Aleutian Chain could see wetter times. In the lower 48, below-normal precipitation is expected in the Pacific Northwest and along the Atlantic Seaboard from the Carolinas up to Maine. A large area of the country’s midsection is expected to again see above-normal precipitation from Texas to the Mississippi Delta north across all of the Great Plains and into the Great Lakes region.
