National Overview - June 2000


NCDC transitioned to the nClimDiv dataset on Thursday, March 13, 2014. This was coincident with the release of the February 2014 monthly monitoring report. For details on this transition, please visit our public FTP site and our U.S. Climate Divisional Database site.

U.S. June Temp 1900-2000

Contents of This Report:

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The North American 500 mb Maps for June

The upper-air pattern remained active during June with several troughs sinking southward from the plains of Canada into the central and southern plains of the U.S. High pressure dominated both the west and east coasts while low pressure dominated the central portion of the country.

The mean upper-level ridge over the West provided warmer than normal conditions from the central and southern Rockies, westward to the Pacific. At the same time, prevalent troughiness in the central part of the country allowed for cooler than normal temperatures. The east coast ridge, an extension of the Bermuda High, made for warmer than normal temperatures along the Atlantic coastal states.

A preview of the southwest monsoon, compliments of the westward extension of the Bermuda High, provided wetter than normal conditions for portions of the Southwest. This same pattern allowed Gulf moisture to progress northward and provide significant rainfall amounts for the mid-Mississippi Valley, Ohio Valley, and the mid-Atlantic region. Dry conditions prevailed over the northern Rockies. NA 500mb Map
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Additional information on hydrometeorological analysis and forecasting can be found at the Hydrometeorological Prediction Center's Web Page. The principles behind the 500 mb flow are briefly explained Here.

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Top of Page National Temperature - June

The June 2000 monthly mean temperature averaged across the contiguous United States, based on preliminary data for the U.S. Historical Climate Network (USHCN), was warmer than normal and ranked as the 33rd warmest June since 1895. About nine percent of the country was much warmer than normal while about one percent of the country was much cooler than normal. The actual June temperature values from 1895 through 2000 are available. US June Temp
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The map to the right, based on approximately 250 airport stations, shows departures from the 1961-1990 normal temperatures for June 2000. The Pacific Coast inland through the southern Rockies was warmer than normal. The mid-Atlantic, central and southern Appalachians were slightly warmer than normal while most of the central half of the country was cooler than normal. Most of the interior and northern Alaska stations were warmer than normal, with the greatest departures in the central part of the state. Most of the southern coastal sites were near normal. The Hawaiian stations averaged only slightly above normal. U.S. June Temperature Departures
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U.S. June Temperature Maxes
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Extreme maximum temperatures during June 2000 exceeded 100° F through a good portion of the Southwest from northern California, southeastward through western Texas. Within this area, temperatures exceeded 110°F in the interior valley of northern California as well as southern California and western Arizona. Temperatures also exceeded 100°F in portions of the central Plains and the Southeast. Maximum temperatures failed to exceed 90° F in portions of the inter-mountain West, most of the Great Lakes region, portions of the mid Mississippi Valley, and most of the the Northeast.

The number of days with high temperatures in excess of 90° F exceeded the average number of days of greater than 90° F for June in portions of the Great Basin, northern interior California and southern Oregon. The average was also exceeded in portions of the inter-mountain West, western High Plains and the Southeast. Within this area, the departure exceeded the average by at least eight days in the upstate of South Carolina and the northern Piedmont of North Carolina. U.S. June Temperature Departures 90+
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U.S. June Temperature Variability
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Day-to-day temperature variability during June was above normal over a large area which included western Texas, from northeast Texas across eastern Oklahoma and into adjoining Arkansas and Missouri, over the central High Plains from northeast Colorado to Southwest South Dakota, and across parts of the Northeast. The areas of greatest below-normal variability occurred across parts of the Gulf coast, northern Nevada, and northeast Montana. Below-normal variability occurred from central Alaska extending to the southwest, while above-normal variability occurred across the northern Alaska coast and across the panhandle.

The standardized temperature anomalies for June 2000 show the abnormal warmth in the western quarter of the country as well as the warmer than normal conditions over portions of the Gulf Coast and mid-Atlantic regions. Cooler than normal conditions are depicted in the western Great Lakes states, mid-Mississippi Valley region, and the southern Plains. This compares well with other temperature indicators. The map animation provided shows the geographical pattern of temperature anomalies for the last 12 months compared to a base period of 1931-1990. Animated TZ Map199907/200006+
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Data provided by scientists at NASA and the Global Hydrology and Climate Center at the University of Alabama in Huntsville show slightly warmer than average temperatures in the lower half of the atmosphere (lowest 8 km or 26,200 feet of the atmosphere) over the U.S. The Microwave Sounding Unit (MSU) on-board NOAA’s TIROS-N polar-orbiting satellite measured warmer than normal temperatures during the June, and January through June (year-to-date) periods. The average lower tropospheric temperature over the continental U.S. was 0.61F above the 1979-1998 long-term mean in June. MSU Temperature
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Top of Page National Precipitation - June

U.S. June Precipitation, 1895-2000
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Based upon preliminary precipitation data, June 2000 ranked as the 14th wettest such month since 1895. About 17% of the country was much wetter than normal while about one percent of the country was much drier than normal. The last four, and eight of the last nine, such months have been above the long-term mean.
The preliminary national standardized precipitation index ranked June 2000 as the 16th wettest June since 1895. U.S. June Precipitation Index, 1895-2000
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The map to the right, based on approximately 250 airport stations, shows June 2000 total precipitation as a departure from 1961-1990 station normals. Above-normal precipitation can be found in the Aleutians, extreme north and southeastern Alaska, while most of the other Alaskan stations, as well as the Hawaiian stations, were drier than normal. On the mainland U.S., stations were predominantly wetter than normal from the Northeast to the western Great Lakes, south through Texas, to Arizona. Stations were drier than normal across most of the Southeast, the western High Plains, the Great Basin, and interior California. U.S. June Precipitation Departures
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Long-term drought areal coverage (as measured by the Palmer Drought Index) decreased when compared to May, with about 16% of the country in severe to extreme drought at the end of June compared to about 23% at the end of May. The percent area of the country experiencing severe to extreme wetness has been hovering around 3 to 5 percent since late 1999. A band of heavy precipitation during June stretched from southern New Mexico and western Texas to the Great Lakes. This rainfall improved drought conditions in parts of the Southwest, central Plains, and Ohio Valley. Severe drought persisted across the Gulf coast into the southern Appalachians, parts of the central Plains, and in patchy areas from the Rockies to the west coast. Although severe to extreme drought persists in many parts of the U.S., several droughts in the past hundred years have covered a much larger area for a much longer time (see graph below right). The current drought, in terms of U.S. areal coverage, is the worst since the drought of the late 1980's.

USPA, 06/2000
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USPA 1900-01/2000-06
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Top of Page National Temperature - January-June 2000

The January-June 2000 mean temperature averaged across the contiguous United States, based on preliminary data for the U.S. Historical Climate Network (USHCN), ranked as the warmest such six-month period since 1895. Over 65% of the country was much warmer than normal while less than two percent of the country was much cooler than normal. The actual year-to-date data values from 1895 through 2000 are available. US Jan-June Temp
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Top of Page National Precipitation - January-June 2000

U.S. Jan-June Precipitation, 1895-2000
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Based upon preliminary precipitation data, January-June 2000 ranked slightly below the long-term mean for precipitation. About six percent of the country was much drier than normal while about five percent of the country was much wetter than normal. January-June 2000 is the first such period in six years to average below the long-term mean.
The preliminary national standardized precipitation index ranked January-June 2000 near the long-term mean. U.S. Jan-June Precipitation Index, 1895-2000
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Current data are based on preliminary reports from River Forecast Center stations and First and Second Order airport stations obtained from the National Weather Service (NWS) Climate Prediction Center and real time Global Telecommunications System (GTS) monthly CLIMAT summaries. THE CURRENT DATA SHOULD BE USED WITH CAUTION. These preliminary data are useful for estimating how current anomalies compare to the historical record, however the actual values and rankings for the current year may change as the final data arrive at NCDC and are processed.

The following NCDC datasets are used for the historical U.S. data: the climate division drought database (TD-9640), and the hurricane datasets (TD-9636 and TD-9697). It should be noted that the climate division drought database consists of monthly data for 344 climate divisions in the contiguous United States. These divisional values are calculated from the 6000+ station Cooperative Observer network.

Citing This Report

NOAA National Climatic Data Center, State of the Climate: National Overview for June 2000, published online July 2000, retrieved on September 2, 2014 from http://www.ncdc.noaa.gov/sotc/national/2000/6.