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As of January 24-30:

A weak ridge in the upper atmosphere tried to assert itself over the western contiguous U.S. (CONUS) during this U.S. Drought Monitor (USDM) week, but Pacific storm systems moved through it in a stronger westerly flow.  The ridge weakened the Pacific systems, limiting their precipitation to coastal areas from northern California to Washington, where 4 to locally 10+ inches of precipitation fell; the upslope portions of the Sierra in northern California, where mostly 2 inches or less precipitation was observed; and across the Pacific Northwest to northern Rockies, where precipitation amounts ranged from 2-4 inches in the north to less than a tenth of an inch in the south.  Most of the Intermountain West and southern California received no precipitation.  The Pacific lows and cold fronts were dried out as they crossed the Rockies, leaving the Great Plains and Upper Midwest with little to no precipitation.  They picked up Gulf of Mexico moisture as they crossed the Mississippi River Valley, dropping 2 or more inches of rain in the wetter areas from southeastern Texas to the East Coast.  Half an inch or more of precipitation occurred from the Lower Mississippi and Ohio Valleys to the East Coast.  In spite of these areas receiving precipitation, the week was wetter than normal only along the northern California to Washington coast, the northern parts of the Pacific Northwest, and parts of the Gulf Coast, and East Coast.  The rest of the CONUS was much drier than normal.  Most of the CONUS was warmer than normal, with temperature departures as much as 10 degrees above normal in the Pacific Northwest and Midwest.  The dryness this week was a continuation of severely dry conditions which have persisted for the last 3 to 4 months across much of the Southwest to southern Plains.  Contraction of drought and abnormal dryness occurred in parts of the South to Mid-Atlantic where the heaviest rains fell, but drought expansion was the rule across the rest of the CONUS.