US Day 3-7 Hazards Outlook
NWS Weather Prediction Center College Park MD
320 PM EST Thu Mar 05 2020
 
Valid Sunday March 08 2020 - Thursday March 12 2020
 
Hazards:
- Heavy precipitation across portions of the southern Sierra Nevada, Tue, Mar 10.
- Heavy precipitation across portions of the northern Cascades, Wed, Mar 11.
- Heavy rain across portions of the Olympic Peninsula, Thu, Mar 12.
- Heavy rain from portions of the mid-Mississippi Valley, across the Tennessee Valley into the 
southern Appalachians, as well as portions of southern California, and central Arizona, Tue-Wed, 
Mar 10-Mar 11.
- Flooding possible across portions of the Southeast.
- Flooding occurring or imminent across portions of the Southeast and the lower Mississippi Valley.
- Flooding likely across portions of the Northern Plains.
- Much above normal temperatures across portions of the central to northern Plains into the upper 
Midwest, Sun, Mar 8.
- Heavy precipitation across portions of the Alaska Panhandle and mainland Alaska, Mon-Tue, Mar 
9-Mar 10.
- Much below normal temperatures for the outer islands of western Alaska, Mon, Mar 9.
- Much below normal temperatures across western Alaska, Mon-Tue, Mar 9-Mar 10.
- Much below normal temperatures across central to eastern Alaska, Tue-Thu, Mar 10-Mar 12.
 
Detailed Summary:

A split flow synoptic pattern is expected to re-establish itself across the U.S. following a more 
amplified pattern over the eastern U.S. this weekend.  Beginning on Sunday, a large area of high 
pressure accompanied with below normal temperatures across the eastern U.S. will begin to move off 
the East Coast.  In the mean time, much warmer than normal temperatures are expected to overspread 
areas from the central to northern Plains and into the upper Midwest ahead of a cold front.  
Afternoon temperatures rising into the 60s could lead to issues related to snow melt across the 
upper Midwest.  In addition to the anomalous warmth, the dry and gusty southerly winds will likely 
raise the fire danger across parts of the central to northern Plains where precipitation has been 
lacking.

As the high pressure system slides off the East Coast, the split flow pattern will re-establish 
itself across the U.S. early next week, leading to a modest convergence of moisture over the 
southern to central Plains.  An extended swath of rain is forecast to spread across the eastern 
two-thirds of the U.S. ahead of a cold front.  It appears that the steady eastward motion of the 
front will keep the rain from being too heavy for much of the area.  Nevertheless, the best chance 
of seeing heavy rain should occur from the mid-Mississippi Valley from Tuesday to Wednesday.  
Farther north, a low pressure system will track eastward across the lower Great Lakes on Tuesday, 
and then across New England Tuesday night.  Wintry precipitation appears likely across the upper 
Great Lakes from late Sunday through early on Tuesday, and through northern New England on Tuesday. 
 The precipitation could be heavy in northern New England depending on the strength of the low.  
Farther upstream, the persistent west-northwest upper-level flow arriving from the Pacific 
Northwest will likely bring a period of snow across the northern Rockies Sunday and Monday, 
followed by heavy wet snow possible across the northern Cascades next Wednesday.  A stronger low 
pressure system arriving from the Pacific could spread heavy rain into the Olympic Peninsula by 
next Thursday.

Another low pressure system associated with the southern stream of the split flow pattern is 
forecast to approach the southwestern U.S. early next week.  Moisture ahead of the system is 
forecast to bring the chance of heavy rain for portions of southern California as well as central 
Arizona by next Tuesday continuing into Wednesday.  Meanwhile, the southern Sierra Nevada should 
see heavy wet snow on Tuesday.

Over Alaska, below normal temperatures should moderate from west to east through the weekend as 
troughing relaxes. However, another 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 next Wednesday. Near the coast, frequent arrival of occluded cyclones will keep a 
good chance of heavy rain/snow along the southern coast of Alaska into the Alaska Panhandle early 
next week.

Kong