US Day 3-7 Hazards Outlook
NWS Weather Prediction Center College Park MD
259 PM EST Mon Jan 28 2019
 
Valid Thursday January 31 2019 - Monday February 04 2019
 
Hazards:
Heavy precipitation (rain and mountain snow) across much of the Pacific Northwest, California, and 
parts of the Southwest, Fri-Sat, Feb 1-Feb 2.
Heavy precipitation across portions of the Great Lakes and the Upper Mississippi Valley, Sun-Mon, 
Feb 3-Feb 4.
Flooding occurring or imminent across portions of the Southeast, the Great Lakes, and the Southern 
Plains.
Much below normal temperatures from the Midwest to the Northeast, Thu-Fri, Jan 31-Feb 1.
High significant wave heights for coastal portions of the Aleutians, Thu-Fri, Jan 31-Feb 1.
 
Detailed Summary:

Much below normal temperatures (-10 to -20+) are expected to continue through the end of this week 
across much of the Upper Mississippi Valley, the Midwest, the Ohio Valley, and into the Northeast. 
Gusty winds in some locations may lead to dangerous wind chill values as well.  Temperatures across 
much of the Central and Eastern states moderate by Saturday with above normal temperatures on the 
order of +10 to +20 degrees possible by next Monday. Another strong high pressure system looks to 
enter the north central U.S. by early next week bringing in another round of below normal 
temperatures (though below criteria at this time).

Out west, a series of upper level troughs moving towards the West Coast and inland will result in a 
few rounds of moderate to heavy rain and mountain snows across much of the West Coast states and 
into parts of the Southwest as well. One shortwave will continue across the mountain west, 
eventually spinning up a low at the surface in the central Plains. This low will track 
northeastward into the Upper Great Lakes. There remain significant differences in both intensity 
and timing for this system, which will have implications for how much precipitation is associated 
with this system and when. It seems likely that some rain will fall along the associated cold front 
as it tracks across the Mississippi Valley into the Ohio/Tennessee Valley/Gulf Coast states, but 
models don't seem to have a good handle yet on how much and whether it will meet criteria for a 
heavy rain area on the Hazards chart. To the north of the low, sufficient cold air may stream down 
allowing for an axis of potentially heavy snows somewhere from the northern Plains to the Upper 
Great Lakes but given the uncertainty in how much falls (a result of rain/snow transition areas), 
opted to keep a general "heavy precipitation" area on the hazards chart for now.

In Alaska, a couple of systems tracking across the Aleutians early in the period will likely result 
in a period of significant waves. These systems are also likely to result in gusty winds and some 
precipitation, but both hazards are forecast to be below criteria so an area was not included on 
the chart.

Santorelli