Tools used in the U.S. Monthly Drought Outlook (MDO) included the Climate Prediction Center (CPC) temperature and precipitation outlooks for July, various short- and medium-range forecasts and models such as the 7-day quantitative precipitation forecast (QPF) totals from the Weather Prediction Center (WPC), the 8-14 day CPC extended-range forecasts (ERFs), the weeks 3-4 outlook from CPC, dynamical models at the monthly time scale, the 384-hour total precipitation forecasts from several runs of the GFS, climatology, and initial conditions (the U.S. Drought Monitor valid on June 26, 2018). During the past few weeks, the Northeast has witnessed consistent dry conditions. Soil moisture anomalies from both CPC and NLDAS (North American Land Data Assimilation System) generally range from 1-2 inches below normal at this time, and according to the GFS model, negative soil moisture anomalies are likely to persist for the next two weeks. ACIS (Applied Climate Information Service) Departure from Normal Precipitation (DNP) for the past 30-days range from 0-3 inches below normal across central and northern portions of the Northeast, with 0-3 inch surpluses (locally greater) indicated over southern portions of the region. ACIS Temperatures were slightly below normal across New York and New England, while as much as 4 degrees F above normal across the remainder of the Northeast region. The 30-day Standardized Precipitation Index (SPI) map depicts drier than normal conditions (values between 0 and -1.5) from eastern Pennsylvania and New Jersey northward, and wetter conditions (values between 0 and +1.5) south of this area. Stream flows are currently within the lowest quartile of the historical distribution in parts of Maine and northern New York, but near to above normal elsewhere. The latest U.S. Drought Monitor (USDM) depicts much of New England and New York in D0 (abnormally dry) and D1 (moderate drought) conditions, which generally corresponds with areas that need between 3-6 inches of rain to end the drought. According to temperature and rainfall forecasts out to one month in advance, prospects for drought relief in the Northeast are pretty slim; in fact, additional drought development appears more likely. Forecast confidence for the Northeast is moderate. With the exception of a few small abnormally dry areas in Alabama, the Southeast is drought free. July precipitation normally accounts for an outsized contribution to the annual precipitation for much of the Southeast. Soil moisture, stream flows, and the 30-day SPI all show near to above normal values across most of the Southeast. With above normal rainfall forecast for most time scales within July, drought development is considered unlikely across the Southeast. Forecast confidence for the Southeast is moderate to high. Recurring thunderstorm clusters (Mesoscale Convective Systems or MCS) have produced heavy rainfall over much of the north-central Mississippi Valley, preventing the onset of dryness and drought in much of Iowa, southern Minnesota, Illinois and Indiana. However, far southern Iowa and the northern half of Missouri have consistently missed out on the MCS-related rainfall, with USDM categories currently ranging between D0 (abnormal dryness) and D2 (severe drought). During the past two weeks, ACIS DNPs range from 0 to negative 4 inches, with Percent of Normal Precipitation (PNP) values generally between 50-100 percent (some localized areas are even lower). ACIS temperatures for the past 30- and 14-days ranged between 4-6 degrees F and 2-4 degrees F above normal, respectively. Soil moisture anomalies of negative 2-6 inches are currently indicated by NLDAS and CPC’s Leaky Bucket in northern and central Missouri, and the GFS model predicts a continued deterioration in soil moisture conditions during the next two weeks. Though U.S. Geological Survey stream and river flows in this region are near to below normal, the amount of rain needed to end the drought (by bringing the Palmer Drought Index to -0.5) is on the order of 6-9 inches. In stark contrast to the Southeast, precipitation outlooks for all time scales out to a month in advance support drought persistence, with drought development favored across most of the remainder of Missouri. Forecast confidence for the Midwest is moderate to high. Across the South, trends inthe USDM depiction generally shows increasingly dry conditions from east to west, culminating in widespread D2 and D3 (severe and extreme drought) indicated over western Oklahoma and western Texas. During the past 30-days, CPC’s rain gauge-based Unified Precipitation Analysis (UPA) indicates the heavier rains (6-8 inches, locally greater) fell in Tennessee, far northern Mississippi, portions of Oklahoma, and near the Texas Coast. Two to four inch precipitation deficits were noted over the areas that missed out on most of this rain, such as much of the Lower Mississippi Valley and Texas, and far southern Oklahoma. The 30-day SPI depicts the driest conditions (-1 to -2) in northern Texas (approximately bounded by Wichita Falls, Abilene, Austin and Longview). ACIS temperatures across the South range from near normal (South Texas) to 4-8 degrees F above normal in northern and central Texas. Negative soil moisture anomalies of 2-5 inches are indicated by both NLDAS and CPC Leaky Bucket model across much of the South, excluding Mississippi and Tennessee, where soil moisture values are either near normal or above normal. Unfortunately, the GFS model does not predict a significant increase to the region's soil moisture for the ensuing two-week period. It would take about 3-9 inches of rain (in some areas, 9-12 inches) to end the drought in this region. Looking forward, based heavily on rainfall predictions for the first half of July, drought improvement and/or removal is deemed the best bet over Louisiana, extreme southwestern Arkansas, and northeastern parts of Texas. In contrast, drought persistence and new drought development is favored in central and eastern Oklahoma, adjacent parts of extreme northern Texas, and also much of northern and central Arkansas, where less rainfall is anticipated. Forecast confidence for the South is moderate for most areas, and high for western portions of both Oklahoma and Texas. In the High Plains region, the most intense drought conditions are currently in central and southern Colorado, and southern and eastern Kansas. Small-scale drought areas are indicated in central North Dakota and eastern South Dakota. Climatologically, July is typically a wet month for the region, in part related to the northward, seasonal migration of the upper-level westerlies and the mean storm track, and also to MCS activity. These nocturnal clusters of thunderstorms provide much of the rain that is needed for agriculture during the growing season. Heavier rainfall (3-9 inches) during the past month was observed in eastern Nebraska, largely related to MCS's and the proximity of meandering baroclinic zones. CPC’s gauge-based UPA reveals precipitation amounts throughout the High Plains region to be mostly near to above normal for the past 30-days, with the exception of 1-4 inch deficits in far eastern Kansas. Since the start of this year, the largest rainfall deficits are in eastern Kansas, on the order of 4-8 inches (locally greater). Negative soil moisture anomalies of 1-4 inches are depicted in central and eastern North Dakota, northeastern South Dakota, and much of Colorado, while even larger deficits (up to 6 inches) are indicated in eastern Kansas. River and stream flows are within the lowest quartile of the historical distribution in eastern Kansas and the western half of Colorado, and near to above normal elsewhere in the region. Anywhere from 3-12 inches of rain are needed to bring the Palmer Drought Index to -0.5 (to end the drought) in North Dakota, Kansas, and Colorado. The fairly localized drought areas in the High Plains region are expected to receive some rain, perhaps enough to offset additional deterioration. Inadequate rainfall amounts predicted over southeastern Kansas in July promote drought development for the last drought-free holdout in that area. Forecast confidence for most of the High Plains is moderate, and moderate to high for southeastern Kansas. Climatologically, much of the West in July is in the midst of its dry season, with the exception of the Southwest where the summer monsoon is just getting started. The latest USDM graphic depicts D2 to D4 (severe to exceptional) drought conditions over most of the Southwest, and widespread D1 to D3 (moderate to extreme drought) in southern California. This is not surprising, given that the May-June period is typically dry just prior to monsoon onset in early July. Stream flows throughout most of the Southwest are easily within the lowest 25%, and in many cases the lowest 10%, of the historical distribution. The onset of the summer monsoon and elevated tropical cyclone activity in the eastern Pacific (along with the potential for Gulf moisture surges) favor drought improvement across a significant portion of the Four Corners region. The predicted area of drought improvement generally coincides with where the highest probabilities of above normal rainfall are indicated on CPC's updated 30-day precipitation outlook, and to a lesser degree on the Week-2 and Week 3-4 precipitation outlooks. Elsewhere, current dryness and drought in Washington and Oregon is unlikely to improve, given the dry climatology. In fact, new drought development is favored for interior portions of the Northwest. In eastern Montana, July climatology favors some relief from the abnormal dryness (D0) and moderate drought (D1) there. However, based on the suite of precipitation outlooks for the month of July, it is thought that there may not be enough rainfall to warrant improvement. Forecast confidence for the Southwest is moderate; and moderate to high across the Northwest. Hawaii, Alaska, and Puerto Rico are currently drought-free. However, precipitation outlooks for most time scales out to a month in advance suggest that current D0 areas (abnormal dryness) could deteriorate to moderate drought conditions (D1). In Hawaii, July is well within their climatological dry season. In contrast, Puerto Rico is typically within their climatological wet season. However, widespread cooler-than-normal sea surface temperatures across the region promote dryness and deterioration. For the Alaska Panhandle, below normal precipitation is favored for most time scales in July, which promotes drought development. However, the precipitation outlooks for the Kenai Peninsula are not as clear cut; hence no drought development was introduced to that area. Forecast confidence is low to moderate for Alaska, and moderate to high for both Hawaii and Puerto Rico. Forecaster: Anthony Artusa Next Monthly Drought Outlook issued: July 31, 2018 at 3 PM EDT