US Day 3-7 Hazards Outlook
NWS Weather Prediction Center College Park MD
404 PM EST Fri Mar 06 2020
 
Valid Monday March 09 2020 - Friday March 13 2020
 
Hazards:
- Heavy precipitation across portions of the northern Rockies, Mon, Mar 9.
- Heavy precipitation across portions of the southern Sierra Nevada and central Maine, Tue, Mar 10.
- Heavy precipitation across portions of the Olympic Peninsula, Thu, Mar 12.
- Heavy precipitation across portions of the northern Cascades, Thu-Fri, Mar 12-Mar 13.
- Heavy rain across portions of the mid-Mississippi Valley into the Midwest, Mon, Mar 9.
- Heavy rain across portions of southern California and into the Desert Southwest, Tue-Wed, Mar 
10-Mar 11.
- Heavy rain from portions of the central and southern Plains across the mid-Mississippi and 
Tennessee Valleys into the Ohio Valley, Wed-Thu, Mar 11-Mar 12.
- Heavy rain across portions of the central Plains to the mid-Mississippi Valley, Fri, Mar 13.
- Heavy snow across northern Maine, Mon-Tue, Mar 9-Mar 10.
- Flooding possible across portions of the Southeast, the southern Appalachians, and the Tennessee 
Valley.
- Flooding occurring or imminent across portions of the Southeast, the lower Mississippi Valley, 
and the upper Midwest.
- Flooding likely across portions of the Southeast, the upper Midwest, and the northern Plains.
- Heavy precipitation across portions of the Alaska Panhandle and coastal southern Alaska, Mon-Tue, 
Mar 9-Mar 10.
- Heavy precipitation across portions of interior southwestern Alaska, Fri, Mar 13.
- Heavy snow across portions of western Alaska, Thu, Mar 12.
- Heavy snow across portions of southern Alaska, Fri, Mar 13.
- High winds across portions of northwestern Alaska, Thu-Fri, Mar 12-Mar 13.
- Much below normal temperatures for much of western Alaska, Mon-Tue, Mar 9-Mar 10.
- Much below normal temperatures across central to eastern Alaska, Wed-Thu, Mar 11-Mar 12.
- Much above normal temperatures for much of the Arctic Coastal Plain of Alaska, Fri, Mar 13.
 

Detailed Summary:

The split synoptic flow pattern is expected to remain in place across the U.S. through the 
medium-range period.  Beginning on Monday, a large high pressure system moving off the East Coast 
will yield to a low pressure system forecast to develop along a front across the central Plains.  A 
long fetch of southerly flow between the two systems is expected to feed warm and moist air from 
the Gulf of Mexico up through much of the eastern U.S. early next week.  In fact, heavy rain 
appears possible over the mid-Mississippi on Monday before the low pressure system spreading snow 
and mixed precipitation into New England Monday into Tuesday.  Some of the precipitation may be 
heavy.

Meanwhile, the southern branch of the split flow pattern will become active again next week as 
moisture well ahead of a low pressure system in the eastern Pacific reaches southern California on 
Monday.  This system has the potential to bring heavy rain into southern California and into the 
Desert Southwest next Tuesday into Wednesday.  The southern portion of the Sierra Nevada could see 
heavy wet snow on Tuesday as well.  The system will move swiftly eastward into the southern Plains 
later next week and will once again raise the threat of heavy rain across the central to southern 
Plains toward the Mid-Mississippi Valley.

Farther north, the persistent west-northwest upper-level flow toward the Pacific Northwest could 
bring a period of wet snow into the northern Rockies around the Yellowstone National Park on 
Monday.  By later next week, moisture associated with a frontal system could bring heavy wet snow 
across the northern Cascades as well as the high elevations of the Olympic Peninsula.

Over Alaska, a cold upper trough will bring the next episode of well-below normal temperatures into 
the western part of the state for early next week, spreading into the eastern part by the middle of 
next week.  Near the coast, a weakening occluded cyclone will keep a good chance of heavy rain/snow 
along the southern coast of Alaska into the Alaska Panhandle next Monday and Tuesday.  By the 
latter part of the week, a large-scale cyclone could spread high winds and widespread snowfall into 
western Alaska while snow should change over to rain over southwestern Alaska.  Areas of heavy snow 
are also possible across portions of western and southern Alaska.  The storm will likely raise 
temperatures to above normal levels across western Alaska by next Friday, especially for the Arctic 
Coastal Plain.

Kong