National Weather Service United States Department of Commerce

Prolonged Atmospheric River in the Northwest; Snow in the North-Central US

A prolonged atmospheric river will bring heavy rainfall which may lead to widespread urban and river flooding, heavy mountain snow, along with gusty winds to the Pacific Northwest into the northern Rockies through much of the week. A clipper will bring a period of snow across the upper Midwest and the Great Lakes into Tuesday, before a stronger system bring more wintry impacts. Read More >

BROKEN TOP
 
 DATE                                        TUESDAY 12/09/25                        WEDNESDAY 12/10/25
 TIME (LT)          16   19   22   01   04   07   10   13   16   19   22   01   04   07   10   13   16
                    4P   7P   10P  1A   4A   7A   10A  1P   4P   7P   10P  1A   4A   7A   10A  1P   4P   
 
 CLOUD COVER        OV   OV   OV   OV   OV   OV   OV   OV   OV   OV   OV   OV   OV   OV   BK   BK   BK
 CLOUD COVER (%)    85   80   75   75   75   80   80   80   80   75   75   70   70   75   65   60   65
 TEMPERATURE        36   36   35   34   37   37   36   38   39   39   40   40   39   39   38   39   37
 MIN/MAX TEMP                           33                  39                  37                  39
 WIND DIR            W    W    W    W    W    W    W    W    W    W    W    W    W    W   SW    W    W
 WIND (MPH)         28   34   36   36   35   28   20   20   20   25   27   28   27   26   21   20   17
 WIND GUST (MPH)    55   64   71   71   67   57   41   41   41   48   54   56   57   51   43   40     
 PRECIP PROB (%)    70   40   50   90   90   90   90   90   90   90   70   70   70   70   50   50   50
 PRECIP TYPE         R    R    R    R    R    R    R    R    R    R    R    R    R    R    R    R    R
 6 HOUR QPF                 0.30      0.32      0.60      0.77      0.53      0.17      0.18      0.02
 6 HOUR SNOW                 0.1       0.1       0.1       0.0       0.0       0.0       0.0       0.0
 6 HOUR ICE                 0.00      0.00      0.00      0.00      0.00      0.00      0.00      0.00
 SNOW LEVEL (KFT)  8.6  8.4  8.3  9.3  9.4  9.2  9.6  9.6  9.8  9.8  9.2  9.0  8.8  8.6  8.5  8.3  8.2
 
 

--- PRECIP TYPE CODES --- 
CODE   TYPE
 T     THUNDERSTORMS
 R     RAIN
 S     SNOW
 I     SLEET
 Z     FREEZING RAIN