 Climate Monitoring / Climate of 1999 / Help
National Oceanic and Atmospheric Administration Climate of 1999 - April
U.S. Regional and Statewide Analyses
National Climatic Data Center, 14 May, 1999
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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 the April Climate can be found at the respective Web Pages of the Southern Regional Climate Center and the Western Regional Climate Center.
Additional information concerning drought conditions in portions of Georgia can be found at the University of Georgia's Cooperative Extension Service Web Page.
Additional 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.
Table 1 shows precipitation and temperature ranks for each of the 9 regions and the nation for April 1999, the two-month period of March-April 1999, the six months of November 1998-April 1999, and the past 12 months, May 1998-April 1999.
PRECIPITATION AND TEMPERATURE RANKS, BASED
ON THE PERIOD 1895-1999. 1 = DRIEST/COLDEST,
105 = WETTEST/WARMEST FOR APRIL 1999,
105 = WETTEST/WARMEST FOR MAR-APR 1999,
104 = WETTEST/WARMEST FOR NOV 1998-APR 1999,
104 = WETTEST/WARMEST FOR MAY 1998-APR 1999.
APR MAR-APR NOV 1998- MAY 1998-
REGION 1999 1999 APR 1999 APR 1999
------ ---- --------- --------- ---------
PRECIPITATION:
NORTHEAST 7 21 20 43
EAST NORTH CENTRAL 96 63 65 74
CENTRAL 69 47 61 81
SOUTHEAST 17 10 22 12
WEST NORTH CENTRAL 91 82 93 101
SOUTH 56 67 65 46
SOUTHWEST 98 68 31 51
NORTHWEST 14 12 101 101
WEST 74 45 44 70
NATIONAL 63 37 60 71
TEMPERATURE:
NORTHEAST 68 65 95 102
EAST NORTH CENTRAL 83 89 100 104
CENTRAL 89 61 99 101
SOUTHEAST 93 54 98 103
WEST NORTH CENTRAL 48 85 100 101
SOUTH 85 72 104 104
SOUTHWEST 16 62 98 101
NORTHWEST 25 35 77 93
WEST 15 31 49 38
NATIONAL 60 72 104 104
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.
Table 2 shows historical extremes for April, the 1961-1990 normal, and the April 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 1.40 1896 6.81 1983 3.42 1.99
EAST NORTH CENTRAL 1.04 1946 4.84 1896 2.63 3.68
CENTRAL 1.55 1915 6.82 1927 3.95 4.30
SOUTHEAST 0.85 1986 7.06 1928 3.52 2.32
WEST NORTH CENTRAL 0.48 1926 2.83 1984 1.62 2.22
SOUTH 1.08 1987 6.92 1957 2.98 3.15
SOUTHWEST 0.26 1989 2.58 1900 0.83 1.64
NORTHWEST 0.61 1977 3.81 1937 1.97 1.06
WEST 0.14 1909 3.25 1967 1.22 1.47
NATIONAL 1.41 1987 3.56 1957 2.38 2.49*
* PRELIMINARY VALUE, CONFIDENCE
INTERVAL + OR - 0.23 INCHES
TEMPERATURE (DEGREES F)
COLDEST WARMEST NORMAL 1999
REGION VALUE YEAR VALUE YEAR TEMP TEMP
------ ---------- ---------- ------ ------
NORTHEAST 38.8 1943 50.4 1921 44.4 45.3
EAST NORTH CENTRAL 35.7 1950 51.8 1915 44.0 46.5
CENTRAL 45.4 1907 59.5 1896 53.4 56.0
SOUTHEAST 56.6 1901 66.6 1954 62.1 65.0
WEST NORTH CENTRAL 34.5 1920 49.5 1915 43.0 42.2
SOUTH 57.2 1983 67.4 1925 62.7 64.4
SOUTHWEST 44.4 1920 55.6 1989 49.9 47.2
NORTHWEST 39.7 1975 52.6 1934 44.9 43.5
WEST 43.3 1967 58.5 1934 51.9 49.5
NATIONAL 47.4 1975 55.7 1981 51.7 52.0*
* PRELIMINARY VALUE, CONFIDENCE
INTERVAL + OR - 0.2 DEG. F.
Table 3 shows statistics for selected river basins: Precipitation rankings are for the hydrologic year-to-date, October-April 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.
PRECIPITATION % AREA % AREA
RIVER BASIN RANK DRY WET
----------- ------------- ------ ------
MISSOURI BASIN 104 0.0% 44.5%
PACIFIC NORTHWEST BASIN 97 0.0% 14.0%
CALIFORNIA RIVER BASIN 44 0.0% 6.7%
GREAT BASIN 41 0.0% 6.7%
UPPER COLORADO BASIN 50 0.0% 0.0%
LOWER COLORADO BASIN 21 28.7% 0.0%
RIO GRANDE BASIN 67 0.0% 0.0%
ARKANSAS-WHITE-RED BASIN 101 0.0% 37.5%
TEXAS GULF COAST BASIN 78 0.0% 0.0%
SOURIS-RED-RAINY BASIN 104 0.0% 23.1%
UPPER MISSISSIPPI BASIN 95 0.0% 7.1%
LOWER MISSISSIPPI BASIN 53 7.7% 0.0%
GREAT LAKES BASIN 40 0.0% 0.0%
OHIO RIVER BASIN 49 0.0% 0.0%
TENNESSEE RIVER BASIN 51 0.0% 0.0%
NEW ENGLAND BASIN 35 0.0% 0.0%
MID-ATLANTIC BASIN 17 22.8% 0.0%
SOUTH ATLANTIC-GULF BASIN 16 18.0% 0.0%
The river basin regions are defined by the U.S. Water Resources Council.
Table 4 shows precipitation and temperature ranks for each of the 9 regions and the nation for the year-to-date, January-April 1999, based on the period 1895-1999. 1 = DRIEST/COLDEST, 105 = WETTEST/HOTTEST.
REGION PRECIPITATION TEMPERATURE
------ ------------- -----------
NORTHEAST 69 81
EAST NORTH CENTRAL 81 96
CENTRAL 72 85
SOUTHEAST 26 77
WEST NORTH CENTRAL 83 97
SOUTH 56 98
SOUTHWEST 30 100
NORTHWEST 84 78
WEST 52 54
NATIONAL 59 99
Table 5 shows historical extremes for January-April, the 1961-1990 normal, and the January-April 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 7.92 1941 17.31 1936 12.05 13.29
EAST NORTH CENTRAL 3.66 1958 9.30 1951 6.58 7.47
CENTRAL 8.13 1941 19.95 1950 13.03 14.86
SOUTHEAST 9.59 1916 24.75 1998 16.55 13.38
WEST NORTH CENTRAL 2.14 1926 5.11 1896 3.80 4.17
SOUTH 5.91 1936 16.78 1973 10.20 10.68
SOUTHWEST 1.12 1972 9.14 1905 3.47 2.94
NORTHWEST 5.95 1977 16.43 1904 11.35 13.14
WEST 3.44 1977 17.01 1995 8.30 8.49
NATIONAL 7.03 1910 12.02 1998 8.90 9.17
TEMPERATURE (DEGREES F)
COLDEST WARMEST NORMAL 1999
REGION VALUE YEAR VALUE YEAR TEMP TEMP
------ ---------- ---------- ------ ------
NORTHEAST 25.6 1904 36.0 1998 30.6 32.5
EAST NORTH CENTRAL 19.0 1936 33.7 1987 26.1 29.9
CENTRAL 33.2 1978 45.2 1921 39.2 41.8
SOUTHEAST 48.2 1978 56.5 1974 52.0 54.3
WEST NORTH CENTRAL 21.0 1936 35.1 1992 28.2 32.2
SOUTH 46.4 1978 54.9 1911 50.5 54.2
SOUTHWEST 35.3 1917 44.7 1986 39.7 42.7
NORTHWEST 30.8 1922 43.4 1934 36.4 37.3
WEST 39.7 1937 50.4 1934 44.8 44.8
NATIONAL 36.1 1979 43.2 1986 39.6 42.3
April 1999 Regional Temperature and Precipitation
| Preliminary data ranked April 1999 as the 13th warmest April on record for the Southeast Region. The region was dominated by high pressure during a good portion of the month which allowed for abundant sunshine and above normal temperatures.
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Preliminary data ranked April 1999 as the 15th coolest April on record for the West Region. A predominant onshore flow and several upper-level troughs, which moved through central and southern California, allowed for cooler than normal conditions.
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| Based upon preliminary data, April 1999 was the 8th wettest April on record for the Southwest Region. Several upper-level closed lows migrated across the region from the Pacific providing some much needed precipitation for the region.
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April 1999 was the 7th driest April since 1895 for the Northeast Region, based upon preliminary data. A predominant east coast ridge kept most precipitation events to the west of the region.
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January-April 1999 Temperature and Precipitation
| The year-to-date, January-April 1999, was the 8th warmest January-April period on record for the South Region.
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Preliminary data ranked January-April 1999 as the 52nd warmest January-April on record for the West Region. The last two such four-month periods have averaged near normal while the prior four such four-month periods were much warmer than normal.
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| January-April 1999 was the 22nd wettest January-April on record for the Northwest Region. The last five such four-month periods have averaged much wetter than normal.
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Preliminary data ranked January-April 1999 as the 30th driest January-April on record for the Southwest Region. For the January through March period, most precipitation events moved north of the region. It was during April that the predominant storm track moved far enough south to bring much-need precipitation to the region.
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| Preliminary data indicate that precipitation averaged across the Primary Corn and Soybean agricultural belt was above normal for the first two months of the six-month growing season and ranked as the 38th wettest such March-April period on record.
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April 1999 Statewide Temperature and Precipitation
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Based upon preliminary data, April 1999 was the fifth warmest such month on record for Louisiana, ninth warmest April on record for Alabama, and the tenth warmest April since 1895 for Florida, Mississippi, and Tennessee. Twenty-two other states ranked within the warm-third portion of the distribution. No state was within the top-ten cool portion of the distribution while ten states ranked within the cool-third.
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| Based upon preliminary data, April 1999 was the third wettest such month on record for Iowa, Kansas, and Wyoming. It was the fourth wettest April since 1895 for Utah, the sixth wettest for Colorado, the ninth wettest for Wisconsin, and the tenth wettest April on record for Nebraska. Eleven other states ranked within the wet third of the distribution. April 1999 was the driest such month on record for Maine and Massachusetts and the second driest April on record for New Hampshire and Vermont. April was the third driest such month on record for Connecticut, the fifth driest for New York, the eighth driest for Georgia, and the tenth driest April since 1895 for Alabama. Fourteen other states ranked within the dry third of the distribution.
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January-April 1999 Statewide Temperature and Precipitation
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Fourteen states ranked within the top-ten warm portion of the distribution for the year-to-date, January-April 1999. The year-to-date was the third warmest such period on record for New Mexico and the fifth warmest such period on record for Colorado and Texas. Thirty-one other states ranked within the warm-third portion of the distribution. Only California ranked within the cool-third of the distribution.
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| Kansas, with a rank of ninth wettest, was the only state within the top-ten wet portion of the distribution for the four-month period, January-April 1999. Nineteen other states ranked within the wet-third of the distribution. Arizona, with a rank of eighth driest, was the only state within the top-ten dry portion of the distribution for the same four-month period. Four other states ranked within the dry-third of the distribution.
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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.
Southeast Region Precipitation Deficit
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Moderate to severe long-term drought plagued the Southeast Region during April, a situation which has been developing over the past year. Ten of the last sixteen months have averaged below normal for precipitation and, in fact, precipitation has averaged below normal for ten of the last 12 months. The Southeast Region covers Virginia to Alabama.
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| Based upon preliminary data, February-April 1999 was the seventh driest such period on record for the Southeast Region. The third wettest such three-month period since 1895 occurred just last year. February-April 1998 had abundant rainfall, a signature of El Niño conditions.
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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 or on the World Wide Web at: http:/www.ncdc.noaa.gov/ol/documentlibrary/cvb.html
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.
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
NCDC / Climate Monitoring / Climate of 1999 / Help
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