US Day 3-7 Hazards Outlook
NWS Weather Prediction Center College Park MD
241 PM EST Thu Jan 02 2020
 
Valid Sunday January 05 2020 - Thursday January 09 2020
 
Hazards:
- Heavy precipitation across portions of the Pacific Northwest and the Northern Great Basin, 
Sun-Tue, Jan 5-Jan 7.
- Heavy rain across portions of the Lower Mississippi Valley and the Southern Plains, Thu, Jan 9.
- Heavy snow across portions of the Northeast, Wed, Jan 8.
- Flooding possible across portions of the Southeast, the Lower Mississippi Valley, and the 
Tennessee Valley.
- Flooding occurring or imminent across portions of the Great Lakes and the Northern Plains.
- High winds across portions of the Northern Plains and the Northern Rockies, Sun-Tue, Jan 5-Jan 7.
- High winds across portions of the Central Rockies and the Central Plains, Mon-Tue, Jan 6-Jan 7.
- High winds across portions of the Central Plains, the Central Appalachians, the Northern Plains, 
the Mid-Atlantic, the Southern Appalachians, the Upper Mississippi Valley, and the Ohio Valley, 
Sun, Jan 5.
- Much below normal temperatures across portions of mainland Alaska, Sun-Tue, Jan 5-Jan 7.
 
Detailed Summary:

A progressive and fairly active weather pattern will predominate across the lower 48 during this 
medium range period (January 5-9). Starting in the Pacific Northwest, a short wave trough and 
associated frontal system will be pushing onshore early Sunday, accompanied by a period of moderate 
to locally heavy precipitation along and west of the Cascades from northern Oregon through 
Washington. Rain is expected along the coast and in the valleys, with snow at the higher 
elevations. There may be a brief respite Sunday evening before another round of precipitation moves 
in late Sunday night through Monday ahead of a system moving through the eastern Pacific. The 
heaviest amounts will likely be a little farther north than the activity earlier Sunday as the main 
moisture axis shifts northward in response short wave ridging building ahead of the deepening 
Pacific storm. This system will then slide across the Pacific Northwest during Tuesday through 
early Wednesday, maintaining unsettled conditions over the Pacific Northwest. Overall, 
precipitation totals from Sunday into Wednesday will range from about 2-5 inches, with the heaviest 
amounts over the Olympics and northern/central Washington Cascades.

Farther east over the northern/central Rockies and Plains, the main concern will be high winds. 
Northwesterly flow behind a rapidly-moving cold front will bring a threat for marginally high winds 
to the Dakotas early Sunday. Meanwhile, post-frontal downslope flow enhanced by an amplifying 
trough crossing the northern Intermountain region will support locally high winds over 
south-central Montana and northern Wyoming Sunday through Tuesday, with a second area of elevated 
winds possible over the southeastern quarter of Wyoming early next week. Sustained winds of 30-40 
mph are expected, with gusts over 50 mph possible. Moderately high winds may also impact sections 
of the central Appalachians early Sunday on the backside of a strengthening low moving into the 
western Atlantic, and then again late in the evening as an upstream cold front rapidly pushes 
across the region.

Over New England, there are indications from several model solutions that a low forming along or 
just off the mid-Atlantic coast will deepen as it moves up along the Northeast coast on Wednesday. 
There is still a fair amount of uncertainty with respect to the strength and track of this feature, 
but felt there was enough confidence to introduce a heavy snow hazard area. Right now, the focus 
appears to be limited to Maine, but if the storm tracks farther west and/or deepens more quickly, 
heavy snow may extend farther south and west across the Northeast.

Late in the period, Gulf of Mexico moisture is forecast to begin streaming northward ahead of 
developing cold front in the central U.S. Widespread showers and isolated thundershowers are likely 
to break out Thursday in this moist air mass as the front progresses eastward. It's a little too 
early to pin down exactly where the heaviest rain may fall, but a general model consensus right now 
points to the lower-mid Mississippi Valley. This area may shift and/or expand in response to 
updated guidance during the next few days.

Much of Alaska will face below normal temperatures for a good part of this medium range period. The 
core of the most anomalously cold air is expected to be across the southwest and central mainland, 
where temperatures during the early-mid part of next week will range from 20-35 degrees below 
normal. Some moderation of this air mass will take place during the latter part of next week.

Klein