Tools used in the U.S. Seasonal Drought Outlook (SDO) included the Climate Prediction Center (CPC) temperature and precipitation outlooks for August and August-October (ASO) 2020, various short- and medium-range forecasts and models such as the 7-day quantitative precipitation forecast (QPF) from the Weather Prediction Center (WPC), the 6-10 day and 8-14 day CPC extended-range forecasts (ERFs), dynamical models at the monthly and seasonal time scales, the 384-hour total precipitation forecasts from several runs of the GFS, climatology for the ASO season, and initial conditions. A La Niņa watch was issued July 9, 2020, with enhanced chances for La Niņa development (50 to 55 percent) during autumn and continuing through winter. If it fails to materialize, there is a 40 to 45 percent chance that conditions will remain ENSO-neutral into next year, and a 5 to 10 percent chance of El Niņo conditions developing. Since a transition toward La Niņa conditions wouldn't start until near the end of the forecast period, La Niņa composites were not used in making this forecast. 

Drought is entrenched across a large part of the Western Region, and this should remain the case through October 2020. All of the extant drought areas should persist or worsen over the period, and drought development is expected in part of the northeastern Navajo Nation.

This is a relatively dry time of year in northern Nevada, Idaho, the Pacific Northwest, and California. Less than 15 percent of annual precipitation falls during ASO in these areas, dropping to under 10 percent across most of California and only 2 to 5 percent along the west-central coastline. At the same time, above-normal temperatures should prevail, making a persistence forecast fairly obvious. Southwestern Montana is a little wetter climatologically, but with warm weather dominating and all other things being equal, persistence also seems logical here.

Farther south and east, the monsoon makes ASO is one of the wetter times of the year across southeastern Utah, New Mexico, and Arizona. These areas get over 30 percent of their yearly precipitation during this period on average, reaching about 45 percent in southern New Mexico. In the short-term, after a dry week, there are enhanced chances of surplus precipitation in Arizona and Utah late in the month. Thereafter, the 3-month outlook favors subnormal ASO precipitation in the areas of drought across Utah, Arizona, and most of New Mexico (A drier than normal August is forecast in southeastern New Mexico, but unusually wet and unusually dry conditions are equally likely there for ASO). In summary, where there is drought, it should continue unabated through the period. 

Forecast confidence for the Western Region is high for California and the Northwest; moderate elsewhere. 
 
In the High Plains Region, the outlook gets better the farther north and east you go. Extreme drought (D3) is firmly entrenched in central and southern Colorado, and parts of adjacent states. Moderate to locally heavy rainfall is expected in parts of this region before the last week of July. Thereafter, odds favor subnormal precipitation in the 6-10 day, 8-14 day, and 3-month outlooks, so any improvement in late July will likely be undone over the ensuing few months.

Farther east, drought in Kansas may expand eastward into central and possibly eastern parts of the state early in the period, but some indicators point toward improvement in autumn -- enough so that we are not forecasting any development to remain throught the end of October.

Elsewhere, moderate to severe drought covers a large part of Wyoming and adjacent South Dakota, and scattered patches of drought dot the remainder of the Dakotas and Nebraska. Moderate to locally heavy rain is expected short-term in parts of the Dakotas and Nebraska, with over 0.5 inch widespread and localized amounts topping 3 inches around the Black Hills. Moderate to heavy precipitation should fall on the higher elevations in Colorado, but only a few tenths are anticipated across the lower elevations and Kansas.

The 3-month ASO outlook shows enhanced chances for abnormally low precipitation totals in central and southern Wyoming, Colorado, central and western Kansas, and southwestern Nebraska. In contrast, not much farther north, ASO is expected to bring excess precipitation to the Dakotas and northeastern Wyoming. Shorter time frames generally feature a similar pattern. Unusually high temperatures should prevail for ASO as a whole, but temperatures will obviously average lower the farther north you go, reducing evaporative stress. Climatology isn't a big player in this forecast. There may be a slight trend for part of the central and northern Plains to get marginally more precipitation now than during other times of the year, but not enough to consider this either a wet season or a dry season. Given all these considerations, the bottom line is -- the farther north, the better. But we have to draw a line somewhere, with drought persisting or intensifying to the south of it, and easing on the north side. The most locigcal delineation would be the edge of the area where surplus ASO precipitation is forecast, thus improvement is shown in the Dakotas while persistence or intensification is expected for most of Wyoming, Nebraska, and points south. . 

Forecast confidence for the High Plains region is High across Colorado and western Kansas, high across the Dakotas, and moderate elsewhere.
 
Drought is restricted to western parts of the Southern Region, but severe to extreme drought has been expanding there for the past few weeks, and now covers much of the western half of Oklahoma, the Texas Panhandle, and northwestern Texas. Farther south, abnormal dryness has been intensifying and expanding, and moderate to severe drought now exists along the central Rio Grande Valley, and moderate drought has increased in coverage across central Texas. This is a relatively wet time of the year across the western halves of Oklahoma and Texas, with 35 to 40 percent or more of annual precipitation usually falling during ASO. Farther east, it's not particularly dry or wet compared to other seasons. 

Moderate to locally heavy rain is expected for about the first 7 days of the period in the Texas Panhandle and adjacent parts of Oklahoma, but otherwise, the ASO period is dominated by forecasts of subnormal precipitation and unreasonably high temperatures. Very little or no precipitatation is expected for the rest of the month across interior Texas, August favors dryness in central and western Texas, and odds for ASO favor dryness in much of Oklahoma and the Texas Panhandle. Given these forecasts and recent trends, drought is expected to expand across a large swath of central and western Texas by the end of October, and probably much earlier. Where drought already esists, conditions will persist or intensify.

Three tiny areas of drought dot areas farther to the east -- two in southeastern Texas and one in southwestern Tennessee. Precipitation is expected to be more robust in these areas, with surplus August precipitation expected in Tennessee, and a wet end to July anticipated in southeastern Texas. Therefore, drought should be removed from these areas by the end of October, and probably much earlier.

Forecast confidence is High for the Southern Region. 
 
Moderate to severe drought covers a significant swath across central and northeastern Minnesota, and moderate drought currently covers part of central and western Iowa. Farther east, across the Great Lakes and northern Ohio Valley, several small areas of drought have recently popped up, but so far they're few and far between. The ASO outlook favors unusually wet weather across Minnesota, but is nondescript elsewhere. The first week of the forecast period should be wet, with amounts of 0.75 to 2.50 inches expected throughout the region. Based on the 6- to 10-day forecast, abundant precipitation should continue into late July, but indicators become mixed and weak after that, and the ASO forecast has no tilt of the odds toward more or less precipitation than normal.

Given heavy precipitation for the first 10 days or so and the widely-scattered, incipient nature of the scattered spots of drought in the northern Ohio Valley, and the forecast for more abundant precipitation in Minnesota where the drought is more entrenched, improvement or removal is forecast for all areas of drought in the Midwest Region.

Forecast confidence is moderate for the Midwest Region.
 
The Southeast Region is almost entirely drought free. Only a small area of moderate drought exists on the DelMarVa Peninsula, in the wake of heavy rains from Tropical Storm Fay. Precipitation forecasts are neutral or favor wetness on most time periods, and in the 3-month outlook, odds favor surplus ASO precipitation regionwide. Drought will be removed from the entire region soon and shouldn't re-develop until after October..  

Forecast confidence is high for the Southeast Region.
 
Following the relatively rapid development of moderate to locally severe drought in the Northeast, Tropical Storm Fay laid down some much-needed rain, and moderate to heavy precipitation again fell on parts of the region a few days later. Drought continues to impact New England, but the rapid intensification cycle was tempered by the recent rains, and some reduction in moisture deficits was observed. In the short-term future, odds favor surplus precipitation during the 6- to 10-day period, likely bringing some additional relief. After that, indicators are weak and mixed, leaving August and ASO precipitation totals indeterminate. However, in some of the seasonal dynamic models, there were broken areas of mildly above-normal ASO precipitation, though not enough to drive a 3-month outlook in that direction. Above-normal temperatures will dominate, tugging conditions away from improvement, but given the weak indicators of wetness, how far north the region is (lower temperatures, less evaporative demand than farther south), and that October is a cool time of year up there, drought conditions are forecast to ease, though with low confidence. 

Forecast confidence is low for the Northeast Region.
 
Alaska has remained drought-free since March, and development is unlikely through early autumn. 

Forecast confidence is high for Alaska.
 
There are fewer tools for long-term forecasting in Hawaii and Puerto Rico compared to the contiguous 48 states, but in both locations, the available data consistently point in one direction -- odds favor increased ASO rainfall across Puerto Rico, while Hawaii should be drier and warmer than normal. To wit, the drought areas in Puerto Rico should at least improve if not be eliminated, but drought should persist or intensify in Hawaii. In addition, drought development is expected in parts of the central and western Big Island, most of Lanai, and southern Mauai. 

Forecast confidence is high for Hawaii and moderate for Puerto Rico.
 
Forecaster: Rich Tinker
 
Next Seasonal Drought Outlook issued: August 20, 2020 at 830am EDT