US Day 3-7 Hazards Outlook
NWS Weather Prediction Center College Park MD
303 PM EST Tue Jan 22 2019
 
Valid Friday January 25 2019 - Tuesday January 29 2019
 
Hazards:
Flooding possible across portions of the Lower Mississippi Valley.
Flooding occurring or imminent across portions of the Southeast, the Southern Plains, the Lower 
Mississippi Valley, and the Pacific Northwest.
Much below normal temperatures from the Upper Mississippi Valley/Midwest to the Lower Great Lakes, 
Fri-Sun, Jan 25-Jan 27.
Much below normal temperatures across portions of the northern Mississippi Valley and Upper 
Midwest, Tue, Jan 29.
Much below normal temperatures across portions of the Southeast, Fri-Sat, Jan 25-Jan 26.
Heavy precipitation (rain and higher elevation snow) across portions of the Alaska Panhandle and 
mainland Alaska, Fri-Sat, Jan 25-Jan 26.
High winds across portions of mainland Alaska and the Aleutians, Sat-Sun, Jan 26-Jan 27, and 
Mon-Tue, Jan 28-29.
High significant wave heights for coastal portions of mainland Alaska and the Aleutians, Sat-Sun, 
Jan 26-Jan 27, and Mon-Tue, Jan 28-Jan 29.
 
Detailed Summary:

The biggest hazard over the CONUS during the medium range period is likely to be much below normal 
temperatures spanning from the Upper Mississippi Valley, across the Midwest, and into the Great 
Lakes. Arctic surface high pressure continues to sink south and eastward into the Ohio 
Valley/Eastern U.S. Friday through the weekend. For the hazards chart, the much below normal 
temperatures area was based on anomalies around 10 to 20 degrees below normal, which would result 
in minimum daily temperature readings below zero, particularly across the Upper Midwest. 
Temperatures warm to closer to normal values briefly early next week before another arctic air mass 
drops into the Upper Midwest next Tuesday. Elsewhere, below normal temperatures are also expected 
to extend southward to the Gulf Coast this weekend, but at this point look to be in the -5 to -10 
degree range which is just outside criteria for an area on the hazards chart. Despite below 
criteria numbers, did opt to draw a much below normal temperatures area from the Florida Panhandle 
to coastal South Carolina due to overnight lows likely to be at or just above freezing and many 
locations here have yet to see their first freeze of the year.

A clipper system drops into the northern Plains late in the weekend and advancing quickly eastward 
into the Midwest, Great Lakes, and eventually the Northeast by next Tuesday. Models continue to 
show the likelyhood of some snow along the northern edge of the precipitation shield, but 
uncertainty remains on whether any accumulations will be significant/hazardous. Refinments to 
amounts/intensity are likely to change in the coming days so its possible a heavy snow area will 
need to be added at some point in the future. At the same time, a surface low looks to track up the 
East Coast by early next week, but again, uncertainty in timing is very high and is dependent on 
the track of the surface low off the coast. The best potential for accumulating snows look to be 
across New England, but its still too early to determine the significance/impact of the snow.

In Alaska, a deep surface low moving across the Aleutians late this week and into the Bering Sea by 
this weekend is likely to produce high winds and significant waves across parts of the Aleutians 
and Alaskan Panhandle, with high winds also extending northward to parts of the southwest mainland. 
Heavy precipitation (low elevation rain and high elevation snow) is likely along the panhandle into 
the Southern Coast this weekend associated with a weakening frontal system, and additional period 
of high winds/significant waves will impact portions of the Aleutians early next week as another 
system moves through.

Santorelli