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    NOAA Seasonal Drought Outlook – August, September, October

    During the past month, generally below-normal rainfall and periods of intense heat affected the Great Plains, the adjacent lower Mississippi Valley, and parts of the Intermountain West. Dryness was particularly acute in central and western Oklahoma, much of Arkansas, and the adjacent Red River Valley. Light rainfall at best fell on these areas, with totals at least 3 inches below normal.

    Excessive heat was most persistent over this same region, leading to significant drought expansion and deterioration.

    Dryness was less acute and not as widespread farther north, but significantly below-normal rainfall also affected much of the central and northeastern Great Plains and the upper Mississippi Valley, where there were areas of deterioration. Much of the Northeast, parts of the Southeast, and much of the Northwest also received less than normal rainfall and patchy areas of drought expansion and intensification.

    In contrast, a robust monsoon season in the Southwest provided some drought relief, and brought flooding into parts of Arizona and New Mexico. Drought also eased somewhat across the Ohio Valley, the adjacent Midwest, and northern portions of the Rockies and High Plains. Rainfall was excessive in parts of Montana, western North Dakota, and northern Wyoming.

    Much of Yellowstone Park experienced flooding and mudslides with heavy rainfall in June, closing parts of the Park at times.

    The August – October 2022 (ASO) U.S. Seasonal Drought Outlook is based on recent conditions, forecasts at various time scales throughout the outlook period, and climatology.

    United States Seasonal Drought Outlook Graphic - click on image to enlarge

    Click Image to Enlarge

    Drought is very likely to persist in much of the West, from California, northern Nevada, and western Montana westward to the Pacific Coast. Meanwhile, robust monsoon rains are expected to continue around the Four Corners Region before waning during autumn.

    Farther north and west, the ASO outlook favors above-normal temperatures and below-normal precipitation in and near sections of the Rockies, Plains, and Mississippi Valley, with more episodes of intense heat possible through the summer. Drought should persist or worsen in these areas, with new drought development expected in part of the Northern Intermountain West, the central and southern Great Plains, and the Mississippi Valley.

    East of the Mississippi Valley, drought is far less widespread. The ASO Outlook favors drier than normal conditions across the Great Lakes Region, keeping the small drought areas there intact. But odds favor above-normal precipitation along parts of the Gulf Coast and across most of the Eastern Seaboard, leading to improvement in areas of drought scattered across those regions.

    Only parts of Maine and some nearby locations are exceptions. The ASO outlook significantly favors warmer than normal weather there, and odds do not tilt toward above-normal rainfall.

    A warm and dry summer in Alaska produced areas of drought and an extremely active wildfire season. Nearly 3 million acres have been scorched through mid-July, which is about the average for the Continental 49 States combined during the last 10 years. Wetter and cooler climatology, along with odds favoring enhanced precipitation in eastern areas, should biring improvement.

    In contrast, drought is likely to persist and may expand slightly across Hawaii, where subnormal precipitation is favored for the month of August and the ASO Outlook. But drought in Puerto Rico is expected to improve, as ASO is one of the wettest times of year there.

    In the Western Region, forecast confidence is high in western and northern sections where the climatology is dry, and moderate elsewhere.

    • Drought remains entrenched across much of the Western Region. Substantial rainfall was restricted to the areas of the Southwest affected by the monsoon, and northern portions of the Rockies and Intermountain West.
    • ASO is a relatively dry time of year across California, northern Nevada, and from western Montana to the Pacific Coast. Less than 20 percent of the annual precipitation total typically falls during ASO in these areas, and in most of California, that number is below 5 percent.
    • For these areas of the West, the dry climatology means there is little chance the precipitation would be heavy enough to bring improvement, so persistence is significantly favored.
    • In contrast, over 30 percent of annual precipitation typically falls during ASO in most of Arizona and New Mexico, primarily during the first half of the period as the monsoon wanes during autumn. In much of southern New Mexico, 40 to 45 percent of annual precipitation is recorded during ASO.
    • To date, the 2022 monsoon has been robust, with above-normal rainfall observed across Arizona and New Mexico, along with portions of Utah and western Colorado.
    • Forecasts favor a continuation of heavy monsoonal rains through at least August, with rainfall decreasing later in the period. Therefore, drought improvement is expected in monsoon-affected areas.
    • Elsewhere, odds tilt toward deficient precipitation in the ASO Outlook across most of Utah, the northern half of Nevada, Idaho south of the Panhandle, and the southern tier of Montana.
    • Neither extreme is favored in other parts of the West, but given the temperature climatology, and the ASO Outlook favoring warmer than normal conditions regionwide, drought seems most likely to persist.
    • Across southwestern Montana and southern Idaho, mild precipitation deficits accumulated over the last 30 days, and with ASO odds favoring above-normal temperatures and near- to below-normal precipitation, drought is expected to develop, connecting the area of drought in northern Montana with the much larger area farther south.

    Forecast confidence is low to moderate for the High Plains Region.

    • Precipitation for the last 4 weeks has varied significantly across the High Plains Region. Abundant precipitation has fallen on most of the Dakotas and northern Minnesota. Moderate to heavy precipitation has been less widespread across Nebraska and northeastern Kansas, with below-normal rainfall experienced over most of Kansas and parts of Nebraska.
    • Farther west, precipitation hasn’t deviated much from normal across Wyoming, and it’s been unusually wet across most of Colorado, especially from the Front Range westward, which has been affected by some monsoon-related rainfall.
    • Temperatures have averaged above-normal almost region-wide.
    • The August and ASO Outlooks imply that the same general conditions will generally prevail over the areas affected by drought for the next 3 months. But for the end of July and early August, a break in this pattern is expected. Above-normal rainfall is forecast for the southern half of the Region, and temperatures should average closer to normal across central and northern parts of the Region.
    • At this time, however, the preponderance of tools indicate that the beneficial pattern change will be temporary, with generally above-normal temperatures and near- to below-normal precipitation favored for ASO as a whole. As a result, areas of extant drought are expected to persist or worsen by the end of October, expanding to cover the entire southern half of the Region east of the Front Range by the end of October. But confidence is reduced due to uncertainties regarding the temporary change in conditions until early August.

    Forecast confidence is low to moderate for the Southern Region, lowered by uncertainties regarding the short-term pattern change.

    • Since mid-June, conditions have deteriorated markedly across the Southern Region outside eastern Tennessee. Light rainfall at best has fallen on eastern Oklahoma, western Arkansas, and adjacent areas of Missouri and the Red River Valley, resulting in 4-week precipitation deficits of over 3 inches.
    • Deficits exceed 4 inches in small areas in southwestern Arkansas and nearby Oklahoma. Most other areas have been drier than normal, though not so dramatically.
    • Only eastern Tennessee, southern and eastern Louisiana, and parts of central and western Texas received surplus rainfall from mid-June to mid-July.
    • In addition, the dryness has been exacerbated by hotter than normal conditions and periods of record or near-record heat, especially in the driest areas in the southeastern Plains and adjacent lower Mississippi Valley. As a result, drought worsened and expanded significantly into a large part of the Southern Region.
    • In the short-term, through early August, models indicate there’ll be a temporary break in this pattern, with above-normal precipitation likely in most areas, although the above-normal temperature are expected to persist.
    • The August Outlook leans toward subnormal precipitation and above-normal temperatures in most areas, and continued abnormal warmth is favored in the ASO Outlook, though enhanced chances for below-normal 3-month precipitation are limited to the western half of Texas and most of Oklahoma.
    • Climatologically, ASO is one of the wetter times of year in the western half of Texas, but leans slightly dry in most of the lower Mississippi Valley.
    • After considering all these factors together, it seems more likely that drought will generally persist through October, with a few areas of deterioration. And given antecedent conditions, drought is expected to expand into all but westernmost Texas, Louisiana outside the Bayou, and central Mississippi, driven significantly by temperatures as well as precipitation.

    Forecast confidence is low for the Midwest Region.

    • Drought coverage increased in the Midwestern Region from mid-June to mid-July, although a significant majority of the Region remains drought-free. The worst deterioration was observed across southern Missouri, adjacent to areas of extreme dryness and heat in the Southern Region.
    • The last 30 days also saw below-normal rainfall across most of Iowa, southern Minnesota, central Indiana, and most of the Great Lakes Region. Rainfall was highly variable elsewhere, but areas that generally received above-normal precipitation include most of Ohio, the northern and southern reaches of Indiana, most of Illinois, northern Missouri, northeastern Iowa, northern Minnesota, and a few patches in Wisconsin and the Upper Peninsula of Michigan.
    • The outlook here favors the August monthly and ASO seasonal Outlook, with enhanced chances for subnormal precipitation almost Region-wide in August, and in areas north and west of the Ohio Valley for the ASO season.
    • Climatologically, August is one of the wetter months of the year north and west of the Ohio Valley, bringing 10 to 15 percent of annual precipitation to western Wisconsin, most of Minnesota, and western Iowa. These facts significantly favor persistence or deterioration in extant drought areas, with expansion into non-drought areas where antecedent conditions are unfavorably dry.
    • Similar to other Regions, however, the outlook is complicated by a temporary pattern shift expected for the remainder of July and early August.
    • The 7-day QPF from WPC shows moderate to heavy precipitation falling on most areas outside Missouri and northern Minnesota, and the 6-10 day and 8-14 day Outlooks show enhanced chances of surplus rainfall across central and southern sections of the Midwest Region.
    • Temperatures are expected to average warmer than normal on most time scales outside the northernmost reaches of the Great Lakes Region.
    • Despite the implications of the short-term pattern change, the tilt of the odds toward dryness for August and/or ASO would favor persistence or deterioration for areas of existing drought, and drought development in a swath from Missouri northward into central Minnesota and adjacent Wisconsin.

    Forecast confidence is high for the Southeast Region.

    • Only small, scattered areas of drought remain in the Southeast Region, with most areas receiving near or above normal rainfall over the past 4 weeks.
    • Outlooks on most time scales show enhanced chances for above-normal precipitation, so the small areas of drought in southern Virginia, eastern North Carolina, and Georgia are expected to be removed by the end of October.

    Forecast confidence for the Northeast Region is moderate.

    • Most of the Northeast Region recorded below-normal precipitation during the past 4 weeks, unlike areas farther to the south. Heavier precipitation was relegated to the southern tier of the Region, upstate New York, and a few swaths across central and northern Maine.
    • Drought now covers most of New England, with small patches also indicated in northern Pennsylvania and western New York.
    • In the ASO seasonal Outlook, odds tilt toward above-normal precipitation in most areas, with no tilt of the odds indicated in most of Maine, northernmost New Hampshire and Vermont, northwestern New York, western Pennsylvania, Delaware, and the eastern West Virginia Panhandle.
    • The highest likelihood for surplus precipitation extends from most of Maryland and Delaware northward along and east the I-95 corridor through Connecticut and part of Rhode Island. The forecast here is based on the ASO Outlook, with drought improvement or removal expected where the ASO outlook shows enhanced chances for wetness, and persistence outside these areas.
    • The broadest area of persistent drought is across Maine and adjacent parts of New England, where the ASO outlook strongly favors above-normal temperatures and the precipitation outlook favors neither wetter nor drier than normal conditions.
    • There is some uncertainty from Vermont eastward through the Portland, ME metro area, where groundwater and other long-term indicators may not respond significantly even if ASO precipitation is somewhat above normal.

    Forecast confidence is high in Alaska, moderate in Hawaii, and low in Puerto Rico.

    • Drier and warmer than normal weather this summer has engendered areas of drought in central Mainland Alaska. Ideal conditions were created for wildfires, which scorched large areas of the interior. About 3 million acres have been burnt so far this year, which is about equal to the 10-year average observed across the 49 continental states combined.
    • Over the next few months, increased climatological rains, lowering temperatures, and an ASO Outlook favoring above-normal rains all point toward drought improvement or removal across the state.
    • Drought covers more than 40 percent of Hawaii as in mid-July, up from about 25 percent in mid-June.
    • The ASO Outlook favors subnormal precipitation statewide, which should keep drought conditions approximately unchanged, with a small increase in coverage possible. Confidence is reduced by the potential for the remnants of tropical systems to impact the Islands, which happened twice in the past few weeks.
    • Climatologically, ASO is a wet season in Puerto Rico, and rainfall has already increased substantially in the past 4 weeks. Most areas in the eastern, north-central, and western parts of the Island recorded 10 to locally 15 inches of rain.
    • Recent trends and climatology drive the forecast for improvement or removal of the drought areas by the end of October, but these are not particularly reliable indicators, and since long-term tropical rainfall is difficult to forecast by nature, the outlook is very uncertain.



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