This publication monitors current and developing climate variations and is
issued as conditions warrant. Questions should be directed as follows:
Area of Concern Source Telephone Number
Current Climate Information Climate Prediction Center, NWS
Climate Operations Branch (301) 763-4670
Analysis Branch (301) 763-8227
Prediction Branch (301) 763-8155
Regional Climate Centers Northeast RCC (607) 255-5950
Southeast RCC (803) 737-0800
Midwest RCC (217) 244-1488
Southern RCC (504) 388-6184
High Plains RCC (402) 472-6706
Western RCC (702) 677-3103
Public Information NWS Public Affairs (301) 713-0622
Historical Perspective NESDIS National Climatic Data Center (704) 271-4800
Water Supply/Forecasts NWS Office of Hydrology* (301) 713-1630
Wildfires National Interagency Coordination Center (208) 387-5512
Agriculture USDA World Agricultural Outlook Board (202) 720-3508
USDA National Agricultural Statistics Service (202) 720-2157
Joint Agricultural Weather Facility (202) 720-7917
Drought Planning National Drought Mitigation Center (402) 472-6707
*There are 13 National Weather Service River Forecast Offices throughout the
U.S. that provide water supply forecasts. Call the above number for the River
Forecast Center with responsibility for your area of interest.
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SUMMER OF 1996: PRELIMINARY ANALYSIS
CONDITIONS:
Most of the central and eastern United States experienced a wet and cool Summer (June - August) while
excessive heat, minimal precipitation, and expansive wildfires affected much of the West. Heavy rains over the
central and south-central Plains, the southern Rockies, and parts of Arizona provided relief from the severe
drought that impacted these regions during the previous 8 months. However, over most of the North American
mid-latitudes, the basic temperature and precipitation patterns which developed in October 1995 (warm and
dry in the West; cool and wet in the East) generally persisted through Winter, Spring, and Summer 1996 with
only a few significant breaks. This corresponded to the persistence of upper-level ridging (northward
jet-stream displacement) over the West, and upper-level troughing (southward jet-stream displacement)
through the Great Lakes and the Northeast.
Frequent cloudiness and precipitation often kept highs below 90F across areas to the north and east of the
central Great Plains, in dramatic contrast to the excessive heat that periodically covered these regions last
Summer. The lack of hot days has been noteworthy over the southern Appalachians, the lower
Northeast, and the mid-Atlantic. From northeastern Kentucky northeastward through West Virginia,
Pennsylvania, and southern New York, many locations (except in the higher elevations) reported highs at or
above 90F on 20 - 33 days during Summer 1995. In contrast, highs reached at least 90F on 3 or fewer days
during June 1 - August 19, 1996 across most of this region, with 5 to 9 days of 90F+ heat reported in the eastern
Ohio Valley. From Philadelphia, PA southward to Richmond, VA, the mercury climbed to at least 90F on 40
to 44 days during Summer 1995, including all-time records for consecutive days with 90F+ heat at
Philadelphia, PA (21), Baltimore, MD (25), and Richmond, VA (27). This year, however, highs reached at least
90F on only 3 days near Philadelphia, and 10 to 15 days farther south as Washington, DC approached its
all-time record for consecutive summer days WITHOUT reaching 90F (35 from July 18 - August 21 and
counting; the all-time summer record is 41).
Despite the unseasonably low number of hot days across the northeastern quarter of the country, Summer
1996 average temperatures have been only slightly below normal across most of the central and eastern United
States. June temperatures actually averaged above normal across the mid-Atlantic, Northeast, and Great
Lakes region, but from July 1 through August 19, departures of -2F to -5F covered a large portion of the
central and eastern states. Again, the persistence of sub-normal temperatures was more impressive
than the magnitude of the negative anomalies. Some locations reported more than 25 successive days with
subnormal daily-average temperatures.
Locally inundating rains fell on parts of the southern and western Great Lakes region, the central
Appalachians, the mid-Atlantic, and the Northeast, resulting in the 2nd wettest June-July period in 102 years
of record for the Northeast Region as a whole (1972 was the wettest), according to the Climate Prediction Center
and the National Climatic Data Center. The first 80 days of Summer 1996 featured 15 to 30 inches of rain at
numerous locations east of the Mississippi River and north of the Gulf Coast states, particularly northern
sections of Illinois and Indiana, the central Appalachians and Piedmont, eastern North Carolina, the East Coast
Megalopolis from Washington, DC northeastward to New York, NY, and northwestern New England. Most
locations east of the Mississippi River (except eastern sections of the Southeast) recorded above normal rain,
with at least 150% of normal soaking much of the mid-Atlantic, east-central Appalachians, and southwestern
and northwestern Great Lakes region. Some of the rain east of the Appalachians fell in association with
Tropical Storm Arthur, which skirted the North Carolina coast in late June, and Hurricane Bertha, which
traversed eastern North Carolina, the mid-Atlantic, and the Northeast in mid-July.
Excessively high daily rainfall totals were observed at a few locations across the northeastern quarter of the
country, including a statewide 24-hour record of nearly 17 inches at Aurora, IL (just southwest of Chicago) on
July 17-18, and 9 to 13 inches over parts of south-central Pennsylvania and north-central Maryland during
June 18-19. Periodic flooding affected the central Appalachians, the mid-Atlantic Piedmont, and parts of the
Ohio Valley, the Northeast, and southeastern Quebec, according to the NWS Office of Hydrology. In many of
these areas, wetness dates back nearly 11 months. During October 1, 1995 - August 19, 1996, most locations
from central Ohio, West Virginia, and Virginia northeastward through northern New York and western Maine
and into southern and eastern Quebec reported 125% to 165% of normal precipitation, as did parts of northern
Illinois and peninsular Michigan. Over 60 inches were reported at Elkins, WV during the period.
Farther to the west, surplus rains across southern sections of the Intermountain West, Rockies, and Plains
were much more beneficial, providing significant relief from the drought that affected these regions from late
Autumn 1995 through May 1996. Between 15 and 20 inches of rain fell during the first 80 days of Summer 1996
across most of Louisiana, southwestern Arkansas, extreme northeastern Texas, parts of Oklahoma, the
northeastern Texas Panhandle, and isolated locations across Kansas and Nebraska. Farther west, 6 to 15 inches
of rain fell on much of the Texas and Oklahoma Panhandles, the central and southern High Plains, and
southern and eastern New Mexico. In the latter area, only 1 to 3 inches of rain were measured through the
previous 8 months (October 1995 - May 1996). These totals represented 150% to 225% of normal in a broad
swath from New Mexico eastward across the Texas and Oklahoma Panhandles and the upper and middle Red
River Valley, and through parts of the lower Mississippi Valley and central Plains.
The persistence of the aforementioned observed anomalies since at least the start of Summer (to as far back
as October 1995 in some instances) can be traced to the persistence of anomalous upper-level ridging and
northward jet-stream displacement across the south-central and western United States while upper-level
troughing and southward jet-stream displacement remained over the East, centered near the Great Lakes.
This same general pattern has dominated the United States and southern Canada since October 1995,
with only a few breaks. Other parts of the Northern Hemisphere have also experienced persistently abnormal
conditions since June, including anomalous upper-level troughing over Greenland, Scandinavia, and the
Arctic region while upper-level ridging covered northeastern Canada, the northeastern Atlantic Ocean, much
of Russia, and the northern Pacific Ocean. For many parts of the Northern Hemisphere, this pattern is nearly
the opposite of the one observed during Summer 1995. Some exceptions to this generalization include
south-central Europe, north-central Africa, and northwestern Canada, all of which reported similar
upper-level anomalies during both summers.
While highs reached 90F on only 10 - 15 days across much of the mid-Atlantic and coastal Carolinas,
typically-mild south-central British Columbia notched 14 - 21 days of 90F+ heat as abnormally warm and
dry conditions dominated much of the West and adjacent Canada. Temperatures averaged 2F to 5F
above normal for the 50-day period ending August 19 across central and southern Texas, northeastern Mexico,
the Southwest, and much of the Far West. In addition, Summer precipitation was below 50% of normal
in most of these areas, as well as parts of the northern Intermountain West and Rockies. While drought
relief occurred farther to the north and east, precipitation totals since October 1995 remained under half of
normal across southern Texas, northwestern New Mexico, much of Arizona, parts of northeastern Mexico, the
southern half of Nevada, and interior southern California. Fortunately, water supplies in these areas are
managed by reservoirs that recharge over the course of decades, so that one dry year has minimal impact on
water supplies. Exceptions to this rule included portions of New Mexico, where the recent rains have failed to
increase low reservoir levels, and the Rio Grande Valley of extreme southwestern Texas and northeastern
Mexico, where river levels and reservoir stores remain unfavorably low.
The combination of abnormally-high temperatures, little rainfall, "dry" thunderstorms, and occasionally
gusty winds provided ideal wildfire conditions over much of the southern and western United States. Despite
the media attention focused on the cool and wet conditions in the East, the expansive stretches of land charred
by wildfires have been more noteworthy. Through August 21, nearly 4.4 million acres were consumed by
wildfires across the 49 continental states since the start of 1996, with over 3.3 million acres (75%) located in
the Southern, Southwestern, Great Basin, California, or Northwestern fire regions, according to the National
Interagency Coordination Center. The nationwide total of 4.4 million acres is more than 242% of the average
January 1 - August 21 acreage burned during the previous 5 years (1991 - 1995), and already ranks 1996 as
3rd among the 19 FULL years of record in terms of the most acreage burned (surpassed only by 1988 [5.0 million
acres] and 1990 [4.8 million acres]). Fire danger is expected to remain high to extreme for the immediate future
across most of California, southwestern and part of southeastern Arizona, Nevada, Oregon, central and
southeastern Washington, southwestern Idaho, west-central and northeastern Utah, northwestern Colorado,
Wyoming, central and eastern Montana, and the west-central and northwestern Dakotas.