During March, surplus precipitation and seasonable temperatures returned to the northern half of California after a very dry and mild February, improving drought conditions by increasing the snow pack and recharging reservoirs and streams; however, the southern section of the state saw another month of subnormal precipitation and above normal temperatures which kept the WYTD precipitation at one-half to two-thirds of normal as drought persisted or worsened. Improvements were also noted in the Northwest and northern Rockies, southern and eastern Texas, and the lower Mississippi Valley as excess March precipitation provided 1 to 2 drought category changes. In New England, heavy rains during early March and unfrozen soils were enough to eliminate long-term D1 as no obvious impacts were noted. In contrast, less than 25% of normal March precipitation fell across the Southwest and into the south-central Plains, expanding areas of D0 and D1 from Arizona eastward into Missouri. Similar conditions occurred in the Dakotas, including monthly temperatures averaging more than 6 deg F above normal, and some deterioration were made. El Nino induced dryness continued across Hawaii, with the most deterioration occurring on the Big Island. With the strong El Nino rapidly weakening, a transition to ENSO-neutral conditions are likely by late spring or early summer 2016, with close to a 50% chance of La Nina conditions developing by the fall. April is a time of transition, with the normally wet winter season winding down in the West and Southwest while the typically dry winter months in the Plains and upper Midwest gradually wetten during the growing season. In addition, the April forecasts were quite challenging, with early month dryness replaced by late month wetness and vice-versa in various regions of the country. Taking this into account, continued improvement was expected in the Northwest and northern sections of California and Nevada as the WYTD precipitation and hydrologic conditions were still in good shape at the end of March, and most short, medium, and monthly outlooks were tilted toward near or above-median precipitation totals. Improvement was also predicted for Utah, Wyoming, and northern Idaho due to recent snows, fairly wet April climatology, and favorable April precipitation forecasts. The small drought area in northwestern Montana had much worse initial conditions (subnormal WYTD precipitation and SWC) than the improvement area to its west, thus persistence was maintained. In contrast, development of drought (where D0 already exists) across Arizona and most of New Mexico is expected during April as the dry winter and March has deteriorated conditions, with numerous impacts now being reported. Although the extended-range forecasts (ERF) at 6-10 and 8-14 days have favorable chances for above-median precipitation, the climatology is quite dry during April (approximately 1-3% of the annual total), with any rain not expected to relieve the past 4 months of dryness. Basin average SWC in Arizona and New Mexico is also dismally low, ranging from 1-47% of normal on March 29. The short-range forecast is also quite dry for the south-central Plains where some drought expansion is possible by mid-April; however, a wetter pattern is forecast for the second half of April which is expected to provide some relief by month's end. Hence, persistence was made here as this region will likely end up very nearly where it is now by the end of April. A fairly wet and cool weather pattern during the first half of April for the eastern half of the Nation should prevent any D0 areas from worsening. In Hawaii, the windward sites should see steadier trade showers during April, thus keeping the D0 areas out of drought; however, for those windward areas in drought, there is not enough confidence that the trade rains would be enough for improvement, hence persistence. In Puerto Rico, widespread improvements are more likely during the tropical Caribbean and Atlantic hurricane season (summer).

Forecaster: David Miskus

Next Monthly Drought Outlook issued: April 30, 2016 at 3:00 PM EDT