This northwesterly flow and its corresponding ridge out West kept much of the western CONUS and Great Plains drier than normal.

But, as a result of the longwave trough, a northwesterly flow dominated the central CONUS. Shortwave ridges and troughs migrated through the jet stream flow, with the troughs and their associated fronts and surface lows bringing above-normal precipitation to the northern High Plains, East Coast, and South, and, later in the month, to parts of the West. Drought Monitor drought map valid December 4, 2018.ĭuring November 2018, the upper-level circulation pattern consisted of a longwave trough over the central to eastern CONUS and ridge over the West Coast which persisted for extended periods throughout the month. including Alaska, Hawaii, and Puerto Rico) was classified as experiencing moderate to exceptional (D1-D4) drought at the end of November. Drought Monitor (USDM), about 22.2 percent of the contiguous U.S. These filenames begin with 'climdiv'.Īccording to the weekly U.S. are available at the Climate Division: Temperature-Precipitation-Drought Data page. Historical temperature, precipitation, and Palmer drought data from 1895 to present for climate divisions, states, and regions in the contiguous U.S. On a broad scale, the 1980s and 1990s were characterized by unusual wetness with short periods of extensive droughts, the 1930s and 1950s were characterized by prolonged periods of extensive droughts with little wetness, and the first two decades of the 2000s saw extensive drought and extensive wetnessĪ file containing the national monthly percent area severely dry and wet from 1900 to present is available for the severe to extreme and moderate to extreme categories. fell in the moderate to extreme drought categories (based on the Palmer Drought Index) at the end of November. fell in the severely to extremely wet categories.Ībout 21 percent of the contiguous U.S. They will change when the final data are processed, but will not be replaced on these pages.īased on the Palmer Drought Index, severe to extreme drought affected about 9 percent of the contiguous United States as of the end of November 2018,Ībout 24 percent of the contiguous U.S. Please note that the values presented in this report are based on preliminary data. State/Regional/National Moisture Status.

Noaa snow totals nj