US Day 3-7 Hazards Outlook
NWS Weather Prediction Center College Park MD
258 PM EST Wed Jan 23 2019
 
Valid Saturday January 26 2019 - Wednesday January 30 2019
 
Hazards:
Heavy rain across portions of southern Florida, Sun-Mon, Jan 27-Jan 28.
Heavy snow across portions of the Lower Great Lakes, Mon, Jan 28.
Heavy snow across portions of the Northeast, Sun, Jan 27 and Tue, Jan29.
Flooding possible across portions of the Mid-Atlantic, the Northeast, the Central Appalachians, the 
Middle Mississippi Valley, the Lower Mississippi Valley, the Great Lakes, and the Ohio Valley.
Flooding occurring or imminent across portions of the Southeast, the Lower Mississippi Valley, and 
the Southern Plains.
Flooding likely across portions of the Southeast and the Central Great Basin.
High winds across portions of the Northern and Central High Plains, Sun-Mon, Jan 27-Jan 28.
Much below normal temperatures across portions of the Middle Mississippi Valley, Ohio Valley, Lower 
Mississippi Valley, and South Texas, Tue-Wed, Jan 29-Jan 30.
Much below normal temperatures across portions of the Upper Midwest and Lower Great Lakes, Sat-Wed, 
Jan 26-Jan 30.
Much below normal temperatures across portions of the Southeast and Gulf Coast, Sat, Jan 26.
Heavy precipitation (rain and high elevation snow) across portions of the Alaska Panhandle and 
mainland Alaska, Sat, Jan 26.
Heavy snow across portions of mainland Alaska, Sat-Sun, Jan 26-Jan 27.
High winds across portions of mainland Alaska and the Aleutians, Sat-Sun, Jan 26-Jan 27.
High winds across portions of the Aleutians, Mon-Tue, Jan 28-Jan 29.
High significant wave heights for coastal portions of mainland Alaska and the Aleutians, Sat-Sun, 
Jan 26-Jan 27.
High significant wave heights for coastal portions of the Aleutians, 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 across the Upper Midwest and into the Lower Great Lakes through much of the 
period. Arctic surface high pressure will sink south and eastward into the Ohio Valley/Eastern U.S. 
through the weekend with daily temperature anomalies of 10 to 20+ degrees below normal likely. 
These types of anomalies would result in minimum daily temperature readings below to well below 
zero, particularly across the Upper Midwest. Temperatures warm slightly for a brief period early 
next week (but still expected to be below normal) before another arctic air mass drops into the 
Central U.S. next week. Much below normal temperatures with this arctic blast will likely extend 
farther south towards the Gulf Coast, with some locations along the western Gulf Coast possible to 
be near freezing. Near freezing (below normal) temperatures are also possible for portions of the 
Florida Panhandle and the Southeast on Saturday, which may result in the first freeze or frost for 
some locations.

A clipper system drops into the northern Plains late in the weekend and advances quickly eastward 
into the Midwest and Great Lakes early next week. Models continue to show the potential for some 
snow along the northern edge of the precipitation shield, but uncertainty remains on accumulation 
amounts. There seems to be better model consensus on the potential for 4+ inches across parts of 
the lower Great Lakes and thus a heavy snow area was added to the hazards chart. Refinements to 
amounts/intensity are likely to change in the coming days so its possible this heavy snow area 
could be extended westward into the Midwest and Northern Plains as well. In the Northeast, an 
initial weak wave moving up the East Coast may bring some heavy snows to mainly northern Maine, 
with an additional round of snowfall likely resulting from the Midwest clipper system next Tuesday 
from upstate New York to Maine.

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. 
There is also the potential for heavy snowfall across parts of western Alaska associated with this 
system. Elsewhere across Alaska, heavy precipitation (rain and high elevation snow) should be 
ongoing to start the weekend across the Panhandle, while another system moving into the Aleutians 
early next week will likely result in another round of high winds/significant waves.

Santorelli