Tools used in the U.S. Seasonal Drought Outlook (SDO) included the official Climate Prediction Center (CPC) temperature and precipitation outlooks for July 2016 and July-September 2016, various short- and medium-range forecasts and models such as the forecast 5-day and 7-day precipitation totals from the Weather Prediction Center (WPC), the 6-10 day, 8-14 day, and weeks 3-4 CPC forecasts, the NAEFS precipitation outlooks, the soil moisture tools based on the Constructed Analog on Soil Moisture (CAS), dynamical models (CFSv2, NMME, IMME, IRI, and IMME), the 384-hour total precipitation forecasts from several runs of the GFS, the four-month Palmer drought termination and amelioration probabilities, July and JAS climatology, the JJA16 (most recently available) Caribbean Regional Climate Center (Caricof) Climate Outlooks (for Puerto Rico), and initial conditions (June 7 Drought Monitor). The transition from El Nino to ENSO neutral occurred in early June, with about a 75% chance of La Nina to develop during the fall and winter. Therefore, climate anomalies associated with ENSO events are not expected to play a significant role in the overall Northern Hemisphere summertime pattern. During the past 60 days, temperature anomalies ranged between 3 and 6 degrees (F) above normal across the Pacific Northwest, with April and June 1-14 departures exceeding 6 degrees F. The unseasonable warmth melted away most of the mountain snow packs, removing a critical source of reservoir recharge during the drier summer months. Abnormal dryness also accompanied the heat, with most locations measuring 50-75 percent of normal precipitation over the same period, with even drier conditions (35-70 percent) going back to mid-March (90-days). USGS 7-day average streamflow conditions are much-below to near-record low levels in western Washington and northwestern Oregon. Accordingly, abnormal dryness (D0) expanded northward across much of the Northwest, although recent cooler and wetter weather has stalled the need for D1. With the snowpack-building season over and most mountains snow-free, the region must rely on seasonal rainfall and temperatures to prevent further deterioration. With the CPC ERF, monthly, and seasonal outlooks favoring a return to above-normal temperatures and sub-median precipitation, and a drier and warmer JAS climatology, drought development is favored for western Oregon, all of Washington, northern Idaho, and western Montana where D0 already occurs, and persistence where existing drought conditions exist (eastern Oregon). Forecast confidence for the Northwest is moderate to high. Streamflow conditions are better across the northern half of California and Nevada as compared to the Northwest, although snow has mostly melted out in the central and southern Sierras as of June 13, with only minimal snow left in the northern Sierra. Reservoir levels across northern California are generally near their historical average levels, with the high volume Lakes Shasta and Oroville reservoirs at 89 and 90 percent of capacity (107 and 109 percent of normal), respectively. Due to these conditions at the start of the summer dry season, significant improvements to the USDM drought depictions were made across northern California and northwestern Nevada in May. Conditions are much poorer across southern California with low streamflow values and below-normal reservoir levels, justifying the extreme (D3) to exceptional (D4) drought depicted of the USDM. JAS months are climatologically a dry and warm time of year across California, so water availability is mainly dictated by reservoir capacities. With this climatology, it is highly unlikely that drought conditions will change substantially during this period. Therefore, persistence of existing drought areas is forecast for California and the Great Basin. Forecast confidence for California and the Great Basin is moderate to high. Widespread above-normal precipitation resulted in drought reductions across Utah, Wyoming, and parts of Montana during the past several months. Temperatures across the northern Rockies were well above-normal during the spring, resulting in early melting of the mountain snow packs. The summer months are a wet time of year across much of Montana and neutral for Wyoming and Utah, although the climatology becomes somewhat drier for all 3 states as fall approaches. During the next 7-days, WPC forecasts moderate precipitation across the northern Rockies and adjacent High Plains, but the medium-range ERFs favor a return to drier and warmer conditions. The CPC monthly and seasonal outlooks both tilt toward sub-median precipitation and above-normal temperatures for the northern Rockies, so the recent wet trend should end as we progress into the summer, leaving the D1 in south-central Montana and north-central Wyoming intact (persistence). As mentioned in the Northwest narrative, the northwestern Montana D1 areas have been drier recently than areas to the east, hence more likely for drought to expand there. Forecast confidence for the northern Rockies is moderate. Some improvements were made across the Four Corners states during the past month, with northwestern Arizona, western Utah, eastern New Mexico, and southwestern Texas getting a 1-category upgrade where 30-day totals were well above normal. Temperatures were also near to below average during the past two months, and snow water content conditions across parts of the central Rockies were still above average, although the snow on the southern Rockies had melted by mid-June. JAS months are a very wet time of year across much of Arizona and New Mexico as the southwest monsoon ramps up. Areas of southeastern Arizona and southern New Mexico normally receive over half their annual total during JAS. Due to the scattered, convective nature of the rainfall, however, it is difficult to pinpoint exactly which areas will realize improvement and which areas will miss out on the Monsoon moisture. And unlike the past 2 monsoon seasons when the JAS outlooks strongly hinted at a robust monsoon, this year's July and JAS outlooks have EC (no help). But with the recent wetness and typically wet time of the year (JAS) in southeastern Arizona and southern New Mexico, even normal rainfall should be enough in these areas for some improvement by the end of September. Elsewhere (southwestern Arizona) where the climatology is not as wet (JAS accounts for 30-40% of annual total) and recent rainfall has been more spotty, persistence is forecast. Forecast confidence for the Southwest is moderate. The spring months have been very wet across the Plains, resulting in widespread drought reductions across both the northern and central Plains. A few areas, however, had missed out on the abundant precipitation during the past 90-days, and recent (30-day) weather has also been dry and warm, resulting in D0-D2 in western South Dakota and D0-D1 in northeastern South Dakota and western Minnesota. The 7-day WPC forecast keeps the heaviest rains just north of these areas, the CPC 8-14 day outlook favors near-median precipitation and near to above-normal readings, and the week 3-4 favors above-median precipitation in the upper Midwest. The CPC monthly outlook for July maintains EC precipitation and EC to slightly above-normal temperatures, while the JAS outlooks depicts a tilt toward above-median precipitation in the north-central Plains and western Corn Belt. While drought expansion is possible during the next several weeks in the north-central Plains and upper Midwest, the possibilities for wetness later in the period negates the development of drought by the end of September. Similarly in southern Iowa, northern Missouri, central Illinois, Indiana, and lower Michigan, 30-day rainfall has been 25-50% of average while temperatures have averaged 2 to 4 degrees F above normal, causing concern for late-planted and young crops. Although the short-term forecasts (out to 14-days) are not depicting any huge relief (near normal), nor are the week 3-4, 1- and 3-month outlooks (EC precipitation, EC or slightly-above normal temperatures), there is no strong signal to forecast any development persisting by the end of September. Forecast confidence for the Plains and Midwest is low to moderate. Much of the Northeast has experienced a dry spring, with precipitation deficits ranging from 3 to 6 inches across much of Pennsylvania, New York, northern New Jersey, and southeastern New England. 7-day average USGS streamflow values are below normal for this time of year, with values much below normal (less than tenth percentile) in coastal New England and far western New York. Temperatures over the past 30- and 60-days were near normal which helped to delay drought onset by keeping evapotranspiration (ET) rates low. Still, abnormal dryness (D0) expanded across much of this region during the past month, with D1 in south-central Pennsylvania, southern Maine, eastern New Hampshire, and northeastern Massachusetts. Since the Northeast typically receives generous precipitation with an even distribution throughout the year, widespread drought conditions are normally difficult to maintain for a long time. During the next week, heavy rains are forecast to overspread the mid-Atlantic region along a stationary front, with lower totals to the north. The CPC 8-14 day outlook does point toward above-median precipitation and near-normal temperatures which should help stem any drought expansion. Both the CPC monthly and seasonal outlooks favor above-median temperatures and EC precipitation. Based on these outlooks and the dry spring conditions, some drought development is likely in New England in the short-term, but with a generous and evenly-distributed precipitation climatology and a more active tropical Atlantic season, the chances favor more precipitation then less, thus the two small D1 areas were removed by the end of September. Forecast confidence for the Northeast is low to moderate. During the past 90-days, most of Tennessee, northern sections of Mississippi, Alabama, and Georgia, and western Carolinas received 50-70 percent of normal precipitation, resulting in deficits of 5-10 inches. As of June 14, 1-, 7-, 14-, and 28-day USGS stream flows have also reacted to the dryness, with many gauges in the lower tenth percentile (much-below average). Accordingly, short-term dryness and drought (D1-D2) has developed. During the next 2 weeks, both WPC's QPF and CPC's ERF forecasts depict sub-median rainfall and above-normal readings in this area, most-likely expanding and intensifying the drought during this period. The CPC July and JAS outlooks favor above-median precipitation along the Gulf Coast, but only EC further inland. However, with the Atlantic and Caribbean tropical season expecting to be more active as compared to last year as El Nino has faded, a few well-placed tropical disturbances or storms could provide ample rainfall to ease the short-term drought. But with no clear guidance as to July and JAS precipitation expectations or whether any tropical storms would actually impact the Southeast, neither expansion nor removal of drought by the end of September could be determined. Therefore, the existing D1 and D2 areas were left as persisting. Forecast confidence for the Southeast is low to moderate. Drought conditions continued to linger across the southwestern facing (leeward) portions of the Hawaiian Islands. The summer months are a normally dry time of year for Hawaii, with east-facing windward slopes receiving most of the rain due to persistent trade winds. An exception to the leeward side climatology exists on the Big Island where the Kona slopes have a wet season during the summer. So even though CPC models predict above-median JAS rainfall, the leewards will most-likely not get enough rain to improve the drought - except on the leeward side of the Big Island (Kona slopes). During the past 30-days, surplus rainfall was limited to northwestern and northeastern sections of Puerto Rico while subnormal rains occurred across southern and central sections of the island. With only a small D1 area lingering in south-central Puerto Rico, a more normal Atlantic and Caribbean tropical season expected with the demise of El Nino, and enhanced odds for above-median JJA rainfall for Puerto Rico from CariCOF (Caribbean Regional Climate Center Outlook Forum), drought removal is expected by the end of September. In Alaska, although recent wetness eliminated the D0 in the southeastern Panhandle, there are still several areas of abnormal dryness remaining, but with a strong tilt toward above-median rainfall in the ERF, 1-, and 3-month outlooks, no drought development is indicated on this outlook. Forecast confidence is moderate for Hawaii, Alaska, and Puerto Rico. Forecaster: David Miskus Next Seasonal Drought Outlook issued: July 21, 2016 at 8:30 AM EDT