US Day 3-7 Hazards Outlook
NWS Weather Prediction Center College Park MD
407 PM EDT Fri Mar 13 2020
 
Valid Monday March 16 2020 - Friday March 20 2020
 
Hazards:
- Heavy precipitation across portions of southern California, Mon-Fri, Mar 16-Mar 20.
- Heavy precipitation across some of the higher elevations of Arizona, Utah, and southwestern 
Colorado, Wed-Thu, Mar 18-Mar 19.
- Heavy precipitation from portions of the central High Plains, across the northern Plains and into 
the upper Midwest, Thu, Mar 19.
- Heavy rain across portions of the southern Plains, Mon-Tue, Mar 16-Mar 17.
- Heavy rain across much of the central and southern Plains, and into the Midwest, Wed-Thu, Mar 
18-Mar 19.
- Heavy rain across much of the Mid-Mississippi Valley, Tennessee Valley, Ohio Valley and into the 
lower Great Lakes and upstate New York, Fri, Mar 20.
- Heavy snow along the Sierra Nevada, Mon-Tue, Mar 16-Mar 17.
- Heavy snow across portions of the northern and central Rockies eastward across the High Plains 
into the northern Plains and the Upper Midwest, Thu-Fri, Mar 19-Mar 20.
- Flooding possible across portions of the northern and southern Plains.
- Flooding occurring or imminent across portions of the Southeast, the lower and upper Mississippi 
Valley, and the northern Plains.
- Flooding likely across portions of the northern Plains and the Southwest.
- High winds across portions of the northern Rockies into the northern and central Plains, Thu, Mar 
19.
- Much below normal temperatures across portions of the interior Pacific Northwest, Mon, Mar 16.
- Much below normal temperatures across portions of the northern and central Montana, Mon-Wed, Mar 
16-Mar 18.
- Heavy precipitation across portions of the Alaska Peninsula, Mon, Mar 16.
- Heavy precipitation across portions of the coastal sections of southern Alaska, Tue, Mar 17.
- Heavy snow across portions of northwestern Alaska, Thu-Fri, Mar 19-Mar 20.
- High winds across much of western and northwestern Alaska, Wed-Fri, Mar 18-Mar 20.
- High winds across the Aleutians, Tue-Wed, Mar 17-Mar 18.
- Much above normal temperatures across much of western and northern Alaska, Mon-Fri, Mar 16-Mar 20.
 
Detailed Summary:

The main story during the medium-range period will be the continual threat of heavy rain across the 
central portion of the country as a large and slow-moving upper low brings areas of heavy 
precipitation into the western U.S. A quasi stationary front will serve as a focusing mechanism for 
the heavy rain to redevelop over the southern Plains while the southwesterly flow ahead of the 
large upper low feeds subtropical moisture from the eastern Pacific. The best chance of heavy rain 
should be centered around areas from northern Texas into Oklahoma through the middle of next week. 
By later next Wednesday into Thursday, the threat of heavy rain should extend farther northeast 
into the Ohio Valley as a surface low pressure system is forecast to develop over the central 
Plains. This low pressure system has the potential to bring significant wintry precipitation 
together with high winds from the northern and central Rockies into the northern and central Plains 
later next week. Farther east, the potential of heavy rain should expand into the lower Great Lakes 
and upstate New York by next Friday.

Meanwhile, a drastic pattern change over Alaska will help push a cold dome of high pressure from 
western Canada into the northern Rockies and the northern Plains during the weekend. Temperatures 
as much as 40 degrees below normal are possible with the coldest temperatures centered in northwest 
Montana. Although the bulk of the arctic air is expected to remain confined over Montana through 
the medium-range period, a large upper low will bring areas of heavy wintry precipitation slowly 
across the southwestern U.S. into the central Rockies through the middle to late next week. The 
Sierra Nevada will likely see heavy snow through Tuesday night. In addition, heavy rain is possible 
for parts of the central valley of California next Monday and Tuesday as the upper low deepens.

In Alaska, the recent synoptic pattern change will bring much milder than normal temperatures into 
much of western and northern Alaska through the medium-range period.  In addition, this pattern 
will be characterized by strong cyclones tracking across northeastern Siberia, as a strong upper 
ridge is forecast to anchored initially over the vicinity of the Gulf of Alaska. By the middle of 
next week, a significant cyclone is forecast to edge closer toward the western portion of the 
region, likely spreading gale-force winds across the Aleutians with periods of rain late Tuesday 
into Wednesday. By Thursday, the system will likely spread gusty gale-force winds together with 
heavy snow into portions of western Alaska where blizzard conditions are possible.  The snowy and 
windy conditions should then spread further north into northern Alaska on Thursday and Friday as 
the storm center is forecast to track toward the Arctic Ocean.

Kong