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National Oceanic and Atmospheric Administration

Climate of 1999 - September
U.S. Regional and Statewide Analyses

Includes Year-To-Date Summary

National Climatic Data Center, 15 October 1999

Standard Regions for Temperature and Precipitation
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Through climate analysis, National Climatic Data Center scientists have identified nine climatically consistent regions within the contiguous United States which are useful for putting current climate anomalies into an historical perspective.



Additional information about current climate anomalies can be found at the respective Web Pages of the Southern Regional Climate Center, Western Regional Climate Center, Midwest Regional Climate Center, Southeast Regional Climate Center, High Plains Regional Climate Center, and the Northeast Regional Climate Center.

Current and historical drought information can be found at the Web Page for the National Drought Mitigation Center. The Center monitors current droughts both in the United States and worldwide.
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Table 1 shows precipitation and temperature ranks for each of the 9 regions and the nation for September 1999, the two-month period of August-September 1999, the six months of April-September 1999, and the past 12 months, October 1998-September 1999.

               PRECIPITATION AND TEMPERATURE RANKS, BASED
               ON THE PERIOD 1895-1999.  1 = DRIEST/COLDEST,
               105 = WETTEST/WARMEST FOR SEPTEMBER 1999,
               105 = WETTEST/WARMEST FOR AUG-SEP 1999,
               105 = WETTEST/WARMEST FOR APR-SEP 1999,
               104 = WETTEST/WARMEST FOR OCT 1998-SEP 1999.
SEP AUG-SEP APR-SEP OCT 1998- REGION 1999 1999 1999 SEP 1999 ------ ---- --------- --------- --------- PRECIPITATION: NORTHEAST 105 102 38 40 EAST NORTH CENTRAL 28 25 100 100 CENTRAL 14 3 12 22 SOUTHEAST 90 54 34 20 WEST NORTH CENTRAL 72 73 90 101 SOUTH 32 7 32 68 SOUTHWEST 50 73 104 89 NORTHWEST 4 16 14 93 WEST 42 44 59 43 NATIONAL 54 15 50 69 TEMPERATURE: NORTHEAST 96 88 102 100 EAST NORTH CENTRAL 28 43 86 100 CENTRAL 43 37 75 97 SOUTHEAST 38 69 66 97 WEST NORTH CENTRAL 21 53 38 96 SOUTH 32 70 76 100 SOUTHWEST 40 45 33 97 NORTHWEST 59 79 32 63 WEST 80 75 36 43 NATIONAL 41 64 63 101

It should be emphasized that all of the temperature and precipitation ranks in Tables 1 through 5 are based on preliminary data. The ranks will change when the final data are processed.

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Table 2 shows historical extremes for September, the 1961-1990 normal, and the September 1999 value for each of the 9 regions and the contiguous U.S. for precipitation and temperature.

                            PRECIPITATION (INCHES)
                           DRIEST     WETTEST   NORMAL  1999
       REGION            VALUE YEAR VALUE YEAR   PCPN   PCPN
       ------            ---------- ----------  ------ ------

      NORTHEAST           1.25 1914  7.67 1999   3.63   7.67
      EAST NORTH CENTRAL  0.95 1952  7.21 1986   3.60   2.60
      CENTRAL             0.70 1897  6.94 1926   3.63   2.20

      SOUTHEAST           1.91 1919  9.26 1979   4.33   6.26
      WEST NORTH CENTRAL  0.47 1952  3.42 1973   1.61   1.75
      SOUTH               0.88 1956  6.88 1913   3.67   2.48

      SOUTHWEST           0.09 1956  3.07 1941   1.46   1.30
      NORTHWEST           0.12 1975  3.42 1959   1.33   0.20
      WEST                0.03 1974  2.00 1976   0.62   0.26

      NATIONAL            1.45 1956  3.57 1986   2.63   2.48*

                          * PRELIMINARY VALUE, CONFIDENCE
                            INTERVAL + OR - 0.18 INCHES

                             TEMPERATURE (DEGREES F)
                           COLDEST    WARMEST   NORMAL  1999
       REGION            VALUE YEAR VALUE YEAR   TEMP   TEMP
       ------            ---------- ----------  ------ ------

      NORTHEAST           56.2 1918  66.5 1961   59.8   63.2
      EAST NORTH CENTRAL  53.5 1918  65.6 1931   58.8   59.1
      CENTRAL             60.5 1918  73.6 1925   66.7   66.6

      SOUTHEAST           68.9 1967  80.3 1925   73.2   72.7
      WEST NORTH CENTRAL  47.4 1965  63.7 1998   56.8   55.1
      SOUTH               67.7 1974  79.5 1911   73.6   73.3

      SOUTHWEST           59.0 1912  67.6 1998   63.9   63.5
      NORTHWEST           52.7 1926  62.7 1990   57.3   57.8
      WEST                61.0 1986  69.9 1979   65.9   68.1

      NATIONAL            62.1 1965  69.1 1998   64.8   64.8*

                          * PRELIMINARY VALUE, CONFIDENCE
                            INTERVAL + OR - 0.3 DEG. F.
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Table 3 shows statistics for selected river basins: Precipitation rankings are for the hydrologic year-to-date, October-September 1998-1999, where 1 = driest, and 104 = wettest, based on the period 1895 to 1999. Also shown is the areal percent of the basin experiencing severe or extreme long-term (Palmer) drought, and areal percent of the basin experiencing severe or extreme long-term (Palmer) wet conditions, as of September 1999.

                                PRECIPITATION  % AREA  % AREA
  RIVER BASIN                       RANK        DRY     WET
  -----------                   -------------  ------  ------

  MISSOURI BASIN                    100          0.8%   45.6%
  PACIFIC NORTHWEST BASIN            87          0.0%    6.0%
  CALIFORNIA RIVER BASIN             42          8.8%    6.7%

  GREAT BASIN                        64          0.0%   10.4%
  UPPER COLORADO BASIN               75          0.0%    0.0%
  LOWER COLORADO BASIN               62          0.0%    0.0%
  RIO GRANDE BASIN                   68          0.0%    3.9%

  ARKANSAS-WHITE-RED BASIN           97          0.0%   54.6%
  TEXAS GULF COAST BASIN             63          0.0%    0.0%
  SOURIS-RED-RAINY BASIN            104          0.0%  100.0%
  UPPER MISSISSIPPI BASIN            89          0.0%    7.4%

  LOWER MISSISSIPPI BASIN            31          7.7%    0.0%
  GREAT LAKES BASIN                  53          0.0%    0.0%
  OHIO RIVER BASIN                   15         52.7%    0.0%
  TENNESSEE RIVER BASIN              36          0.0%    0.0%

  NEW ENGLAND BASIN                  59          0.0%    0.0%
  MID-ATLANTIC BASIN                 40          0.0%    0.0%
  SOUTH ATLANTIC-GULF BASIN          20          9.8%    2.3%

The river basin regions are defined by the U.S. Water Resources Council.

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Table 4 shows precipitation and temperature ranks for each of the 9 regions and the nation for the year-to-date, January-September 1999, based on the period 1895-1999. 1 = DRIEST/COLDEST, 105 = WETTEST/HOTTEST.

REGION PRECIPITATION TEMPERATURE ------ ------------- ----------- NORTHEAST 72 99 EAST NORTH CENTRAL 99 99 CENTRAL 24 82 SOUTHEAST 29 75 WEST NORTH CENTRAL 83 91 SOUTH 50 93 SOUTHWEST 84 96 NORTHWEST 66 65 WEST 53 55 NATIONAL 57 95
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Table 5 shows historical extremes for January-September, the 1961-1990 normal, and the January-September 1999 value for each of the 9 regions and the contiguous U.S. for precipitation and temperature.

PRECIPITATION (INCHES) DRIEST WETTEST NORMAL 1999 REGION VALUE YEAR VALUE YEAR PCPN PCPN ------ ---------- ---------- ------ ------ NORTHEAST 23.82 1941 39.83 1996 30.99 32.80 EAST NORTH CENTRAL 16.74 1910 31.07 1993 24.70 28.49 CENTRAL 24.56 1930 43.13 1950 33.04 30.32 SOUTHEAST 28.88 1954 51.09 1979 40.70 37.48 WEST NORTH CENTRAL 9.33 1934 20.44 1915 14.44 16.03 SOUTH 18.35 1954 36.99 1973 27.71 26.88 SOUTHWEST 6.45 1956 17.55 1941 10.66 12.24 NORTHWEST 10.14 1924 22.97 1983 17.64 18.18 WEST 4.90 1924 22.15 1998 10.95 10.58 NATIONAL 18.78 1934 25.87 1979 22.68 22.84 TEMPERATURE (DEGREES F) COLDEST WARMEST NORMAL 1999 REGION VALUE YEAR VALUE YEAR TEMP TEMP ------ ---------- ---------- ------ ------ NORTHEAST 46.5 1904 52.2 1998 48.7 51.0 EAST NORTH CENTRAL 43.2 1912 51.5 1987 46.9 49.1 CENTRAL 53.7 1979 60.7 1921 56.3 57.9 SOUTHEAST 62.9 1940 67.6 1921 64.8 66.1 WEST NORTH CENTRAL 42.9 1950 50.3 1934 47.1 48.5 SOUTH 62.9 1979 68.2 1911 65.0 66.9 SOUTHWEST 51.8 1917 58.0 1934 55.0 56.3 NORTHWEST 46.6 1955 53.3 1934 49.6 49.6 WEST 55.4 1903 60.7 1934 57.6 57.5 NATIONAL 53.3 1912 57.7 1934 55.4 56.8
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Top of Page The Tropics: A Historical Perspective

After threatening southeastern North Carolina on August 30th, Hurricane Dennis drifted northeastward and became stationary about 150 miles east-southeast of Cape Hatteras for three days. Finally, after drifting southward, Dennis started moving northwestward and made landfall in Carteret County, North Carolina, on the afternoon of September 4th as a strong tropical storm. Dennis SatPic
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Dennis impacted the region with flooding rains, gusty winds, and prolonged heavy surf which led to beach erosion that caused extensive damage to the barrier islands and approximately 1,600 properties. Precipitation totals exceeded twelve inches in some locations of North Carolina. The storm then moved northward providing beneficial rains to drought-stricken areas of the mid-Atlantic and Northeast.


Dennis was the fourth tropical cyclone to make landfall in eastern North Carolina in the last three years.

Hurricane Floyd became an ominous threat to the U.S. Atlantic southeast coast on the 14th. On the day before, Floyd's minimum pressure bottomed at 921 millibars and the maximum winds reached 155 mph, a very strong category 4 storm on the Saffir/Simpson hurricane scale. Hurricane Floyd weakened before making landfall at Cape Fear early on the 16th with winds around 110 mph, but was still a respectable borderline category 3 hurricane. Floyd SatPic
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In conjunction with a stationary trough of low pressure along the coastal inland areas of the Carolinas and Virginia, Floyd dumped copious amounts of rainfall from northeastern South Carolina, northward through New England. Isolated precipitation amounts approaching 20 inches were reported in coastal North Carolina. With these rainfall amounts added to totals provided by Dennis and several frontal passages, areas of North Carolina witnessed unprecedented flooding and major interruptions to daily life. In North Carolina alone, at least 47 people perished and damage estimates exceeded $6 Billion dollars. September monthly precipitation totals approached 30 inches in some locations. The average annual precipitation for the region is slightly over 40 inches.

Hurricane Floyd is the fifth hurricane in just over three years to directly impact southeastern North Carolina. The others were Bertha (7/96), Fran (9/96), Bonnie (8/98), and Dennis (8/99).



For the latest forecasts, warnings, and analyses for the tropical Atlantic and the tropical Eastern North Pacific, visit the National Hurricane Center's web site. For maps of U.S. landfalling major hurricanes and special reports on recent noteworthy storms visit the NCDC Hurricanes page. Additional satellite images and loops of Dennis and Floyd are located at the NCDC Online Images web site. Additional information, including near real-time data can be found at the Weather Underground tropical page.
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Top of Page September 1999 Temperature and Precipitation

Based upon preliminary data, September 1999 was the tenth warmest September on record for the Northeast Region. September 1999 was only the sixth such month since 1972 to be above the long-term mean. Warm Region - September
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Cool Region - September
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Preliminary data for the West-North Central Region ranked September 1999 as the 21st coolest September since 1895. September 1998 was the warmest such month since 1895.
Due to several active frontal zones along with copious tropical moisture from the remnants of hurricanes Dennis and Floyd, September 1999 was the wettest September on record for the Northeast Region. Wet Region - September
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Dry Region - September
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Preliminary data for the Northwest Region ranked September 1999 as the fourth driest September since records began in 1895. A dominant ridge of high pressure in the eastern Pacific kept most storm activity north of the region. Twelve of the last thirteen such months have been at to much below the long-term mean.
Preliminary data indicate that precipitation averaged across the Primary Corn and Soybean agricultural belt ranked near the long-term mean for growing season to date. The last eleven such periods have averaged at or above the long-term mean for precipitation. Primary Corn and Soybean - September
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Top of Page September 1999 Statewide Temperature and Precipitation

September Tmp Map
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Four states ranked within the top ten warm portion of the distribution for September 1999, including:
  • New Hampshire - 2nd warmest
  • Vermont - 2nd warmest
  • Maine - 3rd warmest
  • New York - 7th warmest

    No state ranked within the top ten cool portion of the distribution.

  • Thirteen states ranked within the top ten wet portion of the historical distribution for September 1999, including:
  • Maine - Wettest
  • Maryland - Wettest
  • New Jersey - Wettest
  • Vermont - Wettest
  • Virginia - Wettest

    September 1999 was the driest September since 1895 for Oregon, sixth driest for Tennessee, and the eighth driest for Idaho and Washington.

  • September Pcp Map
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    Top of PageJanuary-September 1999 Statewide Temperature and Precipitation

    Jan-Sep Temp Map
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    Fifteen states were within the top ten warm portion of the distribution for temperature for January-September 1999, including:
  • Maine - 3rd warmest
  • New Hampshire - 3rd warmest
  • Rhode Island - 3rd warmest
  • Massachusetts - 4th warmest
  • Wisconsin - 5th warmest

    No state ranked within the top-ten cool portion of the distribution.

  • Two states ranked within the top ten dry portion of the distribution for January-September 1999, including:
  • West Virginia - 7th driest
  • Kentucky - 9th driest

    Four states ranked within the top ten wet portion of the distribution for the same period including:

  • Minnesota - 3rd wettest
  • Wisconsin - 8th wettest
  • North Dakota - 10th wettest
  • South Dakota - 10th wettest
  • Jan-Sep Pcp Map
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    Top of Page October 1998-September 1999 Statewide Temperature and Precipitation

    Oct-Sep Temp Map
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    Twenty-nine states were within the top ten warm portion of the distribution for temperature for the running twelve month period. Some October 1998-September 1999 ranks included:
  • New Hampshire - Warmest
  • Maine - 2nd warmest
  • Rhode Island - 2nd warmest
  • Vermont - 2nd warmest

    Only California ranked within the cool third portion of the historical distribution.

  • Eight states were within the top 10 wet portion of the distribution for the October 1998-September 1999 period including:
  • Minnesota - Wettest
  • North Dakota - Wettest
  • South Dakota - Wettest
  • Kansas - 5th wettest

    Three states ranked with the top ten dry portion of the distribution for the same period. They included the fourth driest such period for West Virginia, the sixth driest for Georgia, and the tenth driest such twelve-month period since 1895 for Ohio.

  • Oct-Sep Pcp Map
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    It should be emphasized that all of the temperature and precipitation ranks on these maps are based on preliminary data. The ranks will change when the final data are processed.

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    For more information, refer to ...References:

    Thomas R. Karl and Albert J. Koscielny, 1982: "Drought in the United States: 1895-1981." Journal of Climatology, vol. 2, pp. 313-329.

    Thomas R. Karl and Walter James Koss, 1984: "Regional and National Monthly, Seasonal, and Annual Temperature Weighted by Area, 1895-1983." Historical Climatology Series 4-3, National Climatic Data Center, Asheville, NC, 38 pp.

    NOAA's National Climatic Data Center is the world's largest active archive of weather data. The preliminary temperature and precipitation rankings are available from the center by calling: 828-271-4800.

    Historical precipitation and temperature ranking maps are also available on the Internet at: http://nic.fb4.noaa.gov/products/analysis_monitoring/regional_monitoring/usa.html.

    NOAA works closely with the academic and science communities on climate-related research projects to increase the understanding of El Niño and improve forecasting techniques. NOAA's Climate Prediction Center monitors, analyzes and predicts climate events ranging from weeks to seasons for the nation. NOAA also operates the network of data buoys and satellites that provide vital information about the ocean waters, and initiates research projects to improve future climate forecasts. The long lead climate outlooks are available on the Internet at: http://nic.fb4.noaa.gov.

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    For all climate questions other than questions concerning this report, please contact the National Climatic Data Center's Climate Services Division:

    Climate Services Division
    NOAA/National Climatic Data Center
    151 Patton Avenue
    Asheville, NC 28801-5001
    fax: 828-271-4876
    phone: 828-271-4800
    email: ncdc.orders@noaa.gov
    For further information on the historical climate perspective presented in this report, contact:

    William Brown
    NOAA/National Climatic Data Center
    151 Patton Avenue
    Asheville, NC 28801-5001
    fax: 828-271-4328
    email: william.brown@noaa.gov
    -or-
    Mike Changery
    NOAA/National Climatic Data Center
    151 Patton Avenue
    Asheville, NC 28801-5001
    fax: 828-271-4328
    email: mchangry@ncdc.noaa.gov

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