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Based upon preliminary precipitation data, March 2001 ranked as the forty-first wettest such month since records began in 1895. Eight of the last thirteen Marches have been near or above the long-term mean.
The preliminary National Precipitation Index ranked March 2001 as the fiftieth wettest March. Fourteen of the last twenty Marches have had positive index values. |
| The map to the right, based on approximately 250 airport stations, shows March 2001 total precipitation as a percent of the 1961-1990 station normals. Above normal precipitation generally occurred from southern Colorado southeastward through Texas then along the coastal states eastward through Florida then north to southern Maine. Some areas of southern coastal California as well as southern Alaska were also wetter than normal. Below normal precipitation occurred over much of the rest of the country including Hawaii and Puerto Rico. A ridge of high pressure over western sections of the country was associated with generally dry conditions while the Gulf and Atlantic coast states experienced wetter than normal conditions. For further regional analysis, view NCDC's regional page. |  larger image |
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Snow cover duration for March 2001, as observed by satellite, exceeded the 1992-2001 average over a large portion of the northern tier states (see map to left). An animated map of satellite-observed daily snow cover extent shows the daily progression of snow across North America during March. An animated map of daily snow cover, based on several hundred Cooperative stations, gives an indication of how the depth as well as the extent of the snow changed across the U.S. throughout the month. A snow depth analysis by the U.S. Air Force reveals an extensive snow cover remaining over central and eastern Canada. |
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The month started with an extensive snow cover across the central U.S. A couple of mid-month snowstorms dumped heavy snow from the central to northern Plains during the 12th-13th and 16th-18th. The snow cover quickly retreated as temperatures warmed later in the month, but areas of deep snow cover remained in the northern Plains and Northeast. Although snow cover extent in the northern and central Rockies (as shown in the extent and duration map above) was above the 1992-2001 average, snow depth as indicated by mountain snowpack was well below the long-term average across most of the West and the water content of the snow cover was below normal in most river basins. This has raised concerns over spring and summer water supplies, which are heavily dependent on the mountain snowpack accumulated during the winter months. Portions of the northern Plains and upper Great Lakes states remained snow covered throughout the month. Snow depth at the end of March ranged from one to one and a half feet (30 to 45 cm) in northern Minnesota to nearly three feet (90 cm) in the snow belt of Upper Michigan. Records for snow cover duration were set in South Dakota, with Aberdeen logging 144 days with consecutive snow cover (of 1 inch or more) ending on April 1 and Sioux Falls 141 days as of March 27th. Much of the Northeast remained snow covered throughout the month. Snow depth at the end of March in parts of the region ranged from one foot (30 cm) to well over three feet (90 cm). The snow cover was maintained by cold temperatures and a series of storms that swept across the area, including storms on the 6th-7th, 23rd, and 30th-31st. Record and near-record seasonal snowfall totals occurred at many stations, including:
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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.
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: questions@ncdc.noaa.gov
For further information on the historical climate perspective presented in this report, contact:
Jay Lawrimore
NOAA/National Climatic Data Center
151 Patton Avenue
Asheville, NC 28801-5001
fax: 828-271-4328
email: jay.lawrimore@noaa.gov
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