The Mid-Atlantic and Northeast (including the upper Ohio Valley)

Widespread moderate rains (generally 0.5” to 3.0”) eased the drought across much of New England and upstate New York last week, but drier weather to the south allowed drought conditions to intensify. In addition, short-term dryness expanded southwestward into parts of Indiana and Kentucky. On July 9, 39% of Indiana was reported to be short or very short topsoil moisture, compared to just 13% the week before.

Many locations maintained precipitation shortages of 2 to 7 inches since April 1. Specifically, Boston, MA received 4.99” for the 102-day period ending July 11 (normal=10.93”) while New York City recorded 7.17” (normal=12.60”) and Hartford, CT measured 6.37” (normal=12.86”). Farther south, Huntington, WV measured 5.85” (normal=12.78”) while Cincinnati, OH reported 8.90” (normal=13.38”).

Long-term moisture deficits date back more than a year in southern parts of the region. For July 1, 1998 – July 11, 1999, several sites recorded 8 to 18 inches less precipitation than normal, including Washington, DC (25.15”; normal=39.93”), Baltimore, MD (24.19”; normal=42.06”), Williamsport, PA (27.75”; normal=42.19”), and Bridgeport, CT (31.24”; normal=43.00”). As a result, extreme drought (as defined by the Palmer Drought Index) now covers most of Maryland and parts of adjacent Delaware, Virginia, and West Virginia, as well as coastal New Jersey.

According to the United States Geological Survey (USGS), on July 12, 58% of New England measuring sites, 70% of mid-Atlantic sites, and 51% of Ohio Valley sites reported river and stream flows among the lowest 25% on record for the date, modest increases from the previous week. Also, 16% of Pennsylvania oats were in poor or very poor condition, according to the National Agricultural Statistics Service (NASS/USDA). Pasture conditions also declined in southern parts of the region, with large proportions of pasture lands in poor or very poor condition in West Virginia (78%), Virginia (61%), Pennsylvania (59%), and Maryland (43%). In contrast, pastures improved significantly across New York and New England, where significant rainfall was observed. Just 23% of New York pastures were in poor or very poor condition on July 12, well down from 86% just two weeks prior.

Fortunately, for July 14 – 18, rainfall is expected primarily in areas that did not receive significant precipitation through the first two weeks of July. At least 0.5” of rain is expected in the mid-Atlantic from Washington, DC and Philadelphia, PA southward, with totals of 1” to 3” possible in southern Virginia. For the same period, temperatures should average above normal in northern New England and near normal elsewhere. The ensuing five days (July 18 – 22) are expected to bring above-normal temperatures back to the region, but subnormal precipitation should be restricted to areas near the Canadian border. Surplus rainfall is anticipated in the Ohio Valley and western West Virginia.

The Southeast

Another week of moderate to heavy rains abetted drought recovery across much of the region. Patchy dryness continues, but central and southern Georgia, northern Florida, and the eastern Carolinas are the only regions still experiencing fairly widespread problems from dryness, and even these areas improved somewhat during the past week. Still, rainfall at scattered sites remained 4” to 10” below normal since February 1, including Greenville, SC (16.83”; normal=24.55”), Fort Myers, FL (15.69”; normal=22.73”), Macon, GA (14.87”; normal=21.64”), and Jackson, MS (17.33”; normal=25.85”).

The main impact of this dryness remained agricultural. In Georgia, 26% of corn, 11% of cotton, 13% of soybeans, 6% of peanuts, and 6% of pasturelands were in poor or very poor condition on July 9, all of which are improved from the previous week, according to the Georgia Agricultural Statistics Service. Farther north, 10% of North Carolina cotton was in poor or very poor condition. The USGS indicated that streamflows increased during the last several days, with 22% of reporting sites now measuring flows in the lowest 25% of the historical record.

Significant rainfall is again anticipated for the near future, especially in eastern sections. At least 0.5” is expected during July 14 – 18 from the eastern fringes of Tennessee and Alabama eastward, with 1” to 3” possible in the Carolinas, central and eastern Georgia, and southern Florida. The succeeding 5 days (July 18 – 22) are expected to bring near normal rainfall. Temperatures should average near normal through the ten-day period.

Texas

Moderate rains fell during the last several days, with most of the eastern half of the state recording 1” to 3” totals. However, moisture shortages dating back to about February continue to cause some problems. Sites reporting significant precipitation deficits for the February 1 – July 11 period included Houston (16.50”; normal=20.69”), Galveston (13.97”; normal=16.39”), and Laredo (5.14”; normal=9.44”). Most of the dryness is now affecting upper southern Texas and the northern reaches of the state’s Gulf coastline.

Light rainfall (0.25” to 0.5”) is anticipated during July 14 – 18, along the upper Gulf coastline and in most of western Texas. For July 18 – 22, above-normal rainfall is anticipated throughout the state, except along the immediate Gulf coastline and in extreme eastern sections.

The Southwest

Heavy monsoonal thundershowers overspread much of the region last week, significantly reducing the wildfire threat in southern and central parts of the region. Localized flash flooding was reported in some areas, including downtown Las Vegas, NV. Most areas from central Nevada and Utah southward reported at least 0.25,” with scattered locations observing over 1.0.” As of July 11, the National Interagency Coordination Center reported only low or moderate fire danger in Arizona, New Mexico, southern sections of Utah and Nevada, and southeastern California, but high to locally extreme fire danger was noted farther north.

According to USGS, streamflows in the lower Colorado River basin were in the lowest 25% of the historical record for July 12 at 22% of observing sites, down significantly from the 41% reporting similarly low flows on July 3.

A number of locations are still experiencing significant rainfall deficits for the December 1, 1998 – July 11, 1999 period, especially areas that missed much of the past week’s rainfall. For the 223-day period, Truth or Consequences, NM recorded only about half of normal rainfall (1.57”; normal=3.16”), and unfavorable low precipitation totals for the period were also noted at Tucson, AZ (3.07”; normal=4.72”), Reno, NV (2.99”; normal=5.39”), and Bishop, CA (2.30”; normal=4.11”). NASS/USDA reported on July 9 that 65% of Arizona range lands remain in poor or very poor condition because of the dryness.

The monsoon is expected to remain strong during July 14 – 18, with more than 0.25” of rain anticipated in many areas. Five-day totals could exceed 1.0” in much of central and northern Arizona. For the ensuing five days (July 18 – 22), however, monsoonal rainfall is expected to decline somewhat. Surplus rain is expected in central and eastern New Mexico, near-normal totals should fall on northern and eastern Arizona and eastern Utah, but little or no rain is anticipated farther west, including all of Nevada and eastern California. At the same time, warmer-than-normal conditions are expected to return to southern New Mexico, all but northeastern Arizona, and southern sections of Nevada and California.

The Northern Intermountain West

Only patchy light rain (0.25” to 0.5”) fell during the past several days, keeping moisture shortages basically intact. There was also some indication that dryness-related impacts were expanding eastward and southeastward into the northern and central Rockies and toward the Southwest. In Oregon, 65% of topsoils were short or very short of moisture on July 9, up from 48% on June 20, according to NASS/USDA.

The dryness left 10% of Oregon rangelands and 34% of Washington rangelands in poor or very poor condition as of July 9 while the proportion of Washington barley in poor or very poor condition rose to 45%. Fortunately, heavy winter and early spring precipitation in the Pacific Northwest has left streamflows robust, and irrigated crops are doing well because of the abundant water supply.

Over 0.5” of rain could fall during July 14 – 18 in parts of north-central and northeastern Washington and far northern Idaho, but elsewhere little rainfall is anticipated for the next ten days, so any drought-related impacts should persist or intensify during this period.

Alaska

Several months of patchy subnormal precipitation and recent warmth have combined to bring drought-related impacts to much of the state. According to NASS/USDA, topsoil moisture was short across 35% of the state on July 9, but the main problem related to the recent dryness is wildfires. According to the National Interagency Coordination Center, of the approximately two million acres consumed by fires across the United States this year (through July 11), over 40% were in Alaska.

Some areas reporting significantly below-normal precipitation for the March 1 – July 11, 1999 period included Nome (1.89”; normal=3.62”), Fairbanks (2.32”; normal=3.29”), and Cordova (16.39”; normal=26.16”), but several locations are reporting surpluses for the same period. Generally above-normal precipitation is expected for the next several days, so the dryness and wildfire threat should begin to ease.

Hawaii

Subnormal rainfall dates back to at least the beginning of the year in central and western portions of the state, and most of the islands have endured substantially below-normal rainfall since October 1997, leading to long-term water supply difficulties that will require a long recovery period. Between 55% and 75% of normal rainfall was observed during January 1 – July 11, 1999 (except on Hawaii Island), and for the 649-day period October 1, 1997 – July 11, 1999, very low rainfall totals accumulated at Lihue (48.05”; normal=80.46”), Honolulu (14.07”; normal=42.44”), Kahului (19.16”; normal=40.75”), and Hilo (192.07”; normal=233.96”). At Honolulu, this represents only one-third of the normal for a period exceeding 21 months.