Drought coverage remained historically low across the contiguous United States through June 25. For July 2019, however, persistence and some drought expansion should be much more common than improvement. Above normal temperatures and generally subnormal rainfall is expected in the Northwest. Drought should persist there, expanding to cover north-central Oregon and most of Washington by month’s end.
Elsewhere, extant drought should persist and expand into some adjacent areas in the northern Great Plains, south Texas, and portions of the Southeast. A protracted and intense drought in the Four Corners Region has progressively improved this year, and a swath of moderate drought in western New Mexico is all that remains.
The monsoon season gets underway in July, and expected wetter-than-normal conditions for the first half of the month, combined with the seasonal increase in rainfall, is forecast to remove this drought by the end of July. The small area of drought in northeastern Florida is the only other area expected to ease during this period.
Outside the contiguous states, the swath of drought across Puerto Rico should continue, reaching into adjacent areas by the end of July. Drought should also remain in place across the south half of the Alaskan Panhandle, where some degree of dryness has existed for more than a year. Most leeward areas in Hawaii, where July is a relatively dry time of year, are also forecast to remain in drought. Localized parts of central Maui and south-central Oahu are exceptions, with recent heavy rains improving moisture deficits there.
Forecast confidence is high in the Northwest, and moderate in western New Mexico.
- There are two separate areas of drought in the West Region, trending in opposite directions.
- Drought has been deepening and slowly expanding in the Pacific Northwest. Subnormal rainfall is expected through most of this area, plus adjacent locations to the south and east. Also, this is a relatively dry time of the year climatologically, further reducing chances for notable improvement. Thus drought is expected to persist and expand in these areas, putting north-central Oregon and most of Washington into at least moderate drought by the end of the month.
- In sharp contrast, moderate drought in western New Mexico is expected to be removed by the end of the month. Rainfall climatologically increases in July as the monsoon season gets underway, with the month typically bringing about 20 percent of annual precipitation. Generally above-normal rainfall is forecast through at least mid-month, likely providing enough moisture to ease the drought.
- Farther west, the monsoon is expected to get off to a slow start across Arizona, though no drought development is expected at this time, and reduced rainfall may occur after mid-month farther east, reducing confidence for the forecast of drought removal there.
Forecast confidence for the High Plains is low.
- Drought in the High Plains region is currently limited to northern North Dakota. The wet season is on the decline here during July, though the month still typically brings 12 to 15 percent of annual precipitation.
- There are conflicting signals as to what temperature and precipitation patterns will evolve this month, but seasonably hot weather should limit the benefit of any rainfall, and the combination of precipitation and temperatures should keep extant drought intact and allow for some expansion eastward into northern Minnesota. A high degree of uncertainty keeps confidence low, however.
Forecast confidence is moderate to high for the South.
- A few patches of drought are identified in southern Texas. July is expected to be warmer and drier than normal, thus drought is forecast to cover most of the rest of the region by the end of July.
- Climatologically, precipitation is on the wane this month, and hot weather predominates, increasing confidence in the forecast.
Forecast confidence is moderate to high for the Midwest Region.
- No drought exists in the Midwest region at the end of June.
- The wet season is on the decline here during July, though the month still typically brings 12 to 15 percent of annual precipitation. There are conflicting signals as to what temperature and precipitation patterns will evolve this month, but seasonably hot weather should limit the benefit of any rainfall, and the combination of precipitation and temperatures should allow drought in the High Plains to expand eastward across northern Minnesota. A high degree of uncertainty keeps confidence low, however.
Forecast confidence is low in northeast Florida and southeast Georgia, moderate in the Carolinas and near the Gulf Coast, and high in the interior Southeast.
- In the Southeast region, drought covers most of the east-central Carolinas and scattered patches across Alabama, Georgia, and extreme northern Florida.
- July is somewhat wetter than most months in the eastern South Atlantic States and through southern Alabama, but this is not the case farther north and west.
- Wetter than normal conditions are expected for the last half of the month in northeast Florida, with nondescript indicators for the first half of July, and for the month as a whole. This should be sufficient to remove the small area of drought there, but confidence is low.
- Chances for drought persistence and expansion increase progressively northward and westward into the Carolinas, Georgia, and Alabama. There are enhanced chances for subnormal July rainfall across the interior Southeast, but neither dryness nor wetness are favored closer to the Atlantic and Gulf Coasts.
- Outside northeast Florida, drought is expected to persist, with a limited amount of expansion expected into adjacent areas.
Forecast confidence is moderate in the southern tier of the region, and high elsewhere in the Northeast Region.
- The Northeast region has remained drought-free since early November 2018, and no drought is expected to develop, though some limited precipitation shortfalls have developed in a few patches of northern and southern New England, plus the southernmost reaches of the region.
Forecast confidence is high for Alaska.
- Moderate to extreme drought (D1 to D3) coverage remained nearly steady along the southern Alaska Panhandle this past month. July is normally a drier time of year, and with enhanced chances for drier and warmer than normal conditions for the month as a whole, persistence is forecast with high confidence.
Forecast confidence is moderate for Hawaii, tempered by the enhanced chances for surplus precipitation.
- There are enhanced chances for above-normal rainfall in Hawaii during July 2019, but this is a climatologically dry month, and rainfall is not generally expected to be enough for substantial relief; however, small areas of drought removal are expected in central Maui and south-central Oahu. Recent rains improved long-term moisture deficits in these areas.
- Honolulu recorded over 4.5 inches of rain in one 24-hour period, which was more than has been recorded for any other full month of June on record.
Forecast confidence is low to moderate for Puerto Rico.
- Following a decline in drought coverage during May, June brought renewed dryness and some expansion of moderate drought, which now cover part of the northeastern coast, a swath through central portions of the island, and the western half of the southern coastline.
- Though indicators are limited, temperature and precipitation patterns during July 2019 should keep drought intact and allow for some expansion into adjacent areas.