During the past 30-days, patches of drought improvement were depicted by the Drought Monitor in parts of the Pacific Coast States, northern Four Corners region, Great Plains, and upper South Atlantic Coast. Improvement was more widespread than persistence in the parts of these areas east of the High Plains while persistence prevailed farther west.
Patchy mild improvement occurred in the core D3-D4 region of drought in the Four Corners region, but most of that area remained unchanged, as did the drought in southeastern Alaska. Drought deterioration was limited to parts of central Nevada and southeastern Florida. Southeastern Florida is the only region east of the Great Plains experiencing any degree of drought.
The Monthly Drought Outlook (MDO) valid for January 2019 expects drought persistence to prevail across most of the 48 states and Alaska, with patches of deterioration possible. Drought improvement or removal east of the Rockies should be limited to the moderate drought area in the Missouri/Oklahoma border region, where abundant precipitation is expected early in the period.
Farther west, the largest area of forecast improvement or removal is across southern California and western Arizona, where indicators strongly favor copious precipitation early- to mid-month. Other areas expected to improve are The San Joaquin Valley (where above-normal precipitation should ease moderate drought during a wet time of year) and northwestern Oregon (where recent heavy precipitation should persist into mid-month).
Long-term hydrologic drought is expected to persist across the southern portion of the Alaska Panhandle despite storminess expected during the first half of January. The Hawaiian Islands, Puerto Rico, and the entire eastern half of the contiguous 48 states (outside Florida) are forecast to become or remain drought-free by the end of January.
Forecast confidence is moderate to high across the southern and northern tiers of the Western Region, and moderate to low in central areas.
- The vast majority of the nation’s drought is occurring in the Western Region, plus Colorado. Protracted, entrenched D3-D4 conditions cover the central to east-central Four Corners states.
- Broad swaths of D3 exist in central and eastern Oregon, with smaller patches of extreme drought in north-central and southeastern California and over northeastern Utah. Severe drought covers most of the rest of the Four Corners Region, northern Utah, most of Oregon, and smaller adjacent areas in addition to parts of west-central Arizona and southern California.
- Odds favor above-normal January precipitation from the southern one-third of California eastward through the southern two-thirds of the Four Corners states. But despite the monthly outlook, drought persistence is forecast for most of this region.
- Drought is well entrenched through much of this area (which includes much of the core Four Corners’ D3-D4 region), and from central Arizona and Utah eastward, January is a relatively dry time of year, especially in the eastern Rockies and High Plains.
- This limits the chances that precipitation, even if above-normal, can significantly cut long-term moisture deficits.
- There are parts of this broad region where drought improvement or removal is anticipated. Specifically, conditions in southern California and western Arizona should improve, as indicators strongly favor copious precipitation there.
- Drought is forecast to be removed from the San Joaquin Valley, where anticipated above-normal precipitation during one of the wettest months of the year should ease moderate drought (D1).
- Farther north, a warm January plus a nondescript monthly precipitation outlook makes persistence the forecast of least regret. Even above-normal precipitation could result in subnormal snowpack due to the expected mild temperatures, and with snowpack typically increasing into late March, it is unlikely that January precipitation will be enough to firmly determine whether or not drought improvement is underway.
- Across the northern tier of the Western Region, odds favor subnormal January precipitation and thus drought persistence. The only exception is in northwestern Oregon, where recent heavy precipitation may continue almost into the middle of one of the wettest months of the year.
- If the last half of the month is drier, it is unlikely to change conditions established during the first half of January.
Forecast confidence for the High Plains region is high.
- The areas of drought in the High Plains should persist. Colorado is discussed in the Western Region paragraphs above; elsewhere, drought is limited to the southern tier of Wyoming and northern North Dakota.
- Most of North Dakota receives only 1.0 to 3.5 percent of its annual precipitation during January, and the monthly outlook favors subnormal precipitation in southern Wyoming, where climatology is only slightly wetter.
Forecast confidence for the South is high.
- The South Region is also mostly drought free at this time. Only small areas of drought are noted in part of the central Texas Panhandle, and across northeastern Oklahoma.
- Dry climatology favors drought persistence in Texas.
- In northeastern Oklahoma, adjacent areas in southwestern Missouri and small parts of Arkansas and Kansas, heavy precipitation early in the period is expected to result in drought removal.
Forecast confidence for the Midwest region is high.
- There is no drought over the Midwestern states at this time outside the small section of southwestern Missouri discussed in the Southern Region paragraphs. By the end of January, the entire region is expected to be drought free, with no development anticipated.
Forecast confidence is moderate to high in southeastern Florida.
- Across the Southeast region, only southeastern Florida is enduring any degree of drought. Although the El Niño development favors above-normal precipitation here, all other dynamic and objective indicators point toward a dry January, which is a drier time of year to begin with.
Forecast confidence is moderate to high for the Northeast Region.
- At present, there is no drought over the Northeast, and despite patches of short-term dryness in upper New England, no drought development is expected due to large extant surpluses in the southern half of the area, and seasonably- to abnormally-cold conditions farther north.
Forecast confidence is moderate to high for Alaska.
- Moderate to severe drought continues along the southern Alaska Panhandle. As this is primarily a long-term hydrologic drought, it is thought the drought will continue through the month of December despite suplus precipitation anticipated through the first half of the month.
Forecast confidence is moderate for Hawaii and Puerto Rico.
- The Hawaiian Islands and Puerto Rico both have areas of short-term dryness, but drought development is not anticipated.