US Day 3-7 Hazards Outlook
NWS Weather Prediction Center College Park MD
259 PM EST Thu Nov 21 2019
 
Valid Sunday November 24 2019 - Thursday November 28 2019
 
Hazards:
- Heavy precipitation across portions of the Northeast, Wed-Thu, Nov 27-Nov 28.
- Heavy precipitation across portions of the Upper Midwest into the central Great Lakes, and for 
parts of the Pacific Northwest into northwest California, Tue-Wed, Nov 26-Nov 27.
- Heavy snow across much of the Sierra Nevada, Wed-Thu, Nov 27-Nov 28.
- Heavy snow across portions of northern New England, Sun, Nov 24.
- Heavy snow across portions of northern Idaho, Mon-Tue, Nov 25-Nov 26.
- Heavy rain across portions of the Southeast, the Southern Appalachians, the Lower Mississippi 
Valley and the Ohio Valley, as well as the Tennessee Valley, Tue-Wed, Nov 26-Nov 27.
- Flooding occurring or imminent across portions of the Northern Plains.
- Heavy precipitation across portions of western Alaska, Mon-Tue, Nov 25-Nov 26.
- Heavy precipitation across portions of mainland Alaska, Wed, Nov 27.
- High winds across portions of western Alaska, Mon-Wed, Nov 25-Nov 27.
- High significant wave heights for coastal portions of western Alaska, Mon-Tue, Nov 25-Nov 26.
 
Detailed Summary:

Model guidance has continued to indicate a trend for a low pressure system to track closer to the 
New England coast for this weekend.  As a result, the chance of wintry precipitation over interior 
New England has continued to increase early on Sunday.  A heavy snow area has now been introduced 
on the hazards outlook chart.  Closer to the coast, more rain than snow is expected.  The 
precipitation should taper off early on Monday as the storm moves away into the Canadian Maritimes.

The passage of multiple impulse/jet energies behind a cold front will bring extended periods of 
heavy coastal rains and inland elevation snows into the Pacific Northwest from Sunday onward into 
next week. Digging cold flow into midweek should also support the spread of snow increasingly 
inland, especially into favored terrain across the north-central Great Basin/Rockies.  Models are 
showing a trend for a large-scale upper-level trough to dig deeper toward the southwestern U.S. by 
Thanksgiving Day.  This will tend to expand the coverage of the snow across the higher elevations 
of the western U.S. into the middle of next week.  In addition, some models are indicating the 
possibility of a smaller scale cyclone pushing rapidly into California by around Wednesday.  The 
uncertainty is too high at this point to provide additional details.  Nevertheless, it appears that 
the Sierra Nevada will be impacted by heavy snow during the middle of next week.

Over the central portion of the country, models have been indicating the possibility of a low 
pressure system to track across the central Plains toward the Great Lakes by the middle of next 
week.  Uncertainty remains high regarding this system but potential exists for wintry precipitation 
to impact areas just to the north and west of the storm track.  An area of heavy precipitation is 
indicated from Wisconsin to the central Great Lakes where the greatest chance of wintry 
precipitation is forecast at this point in time.  By Thanksgiving Day, this storm should be heading 
toward the northeastern U.S. into southeastern Canada.  This will result in an increasing chance of 
heavy wet snow or mixed precipitation mainly for the higher elevations of the northeastern U.S. 
next Wednesday into Thanksgiving Day.

Over Alaska, strong flow around a deep Bering Sea low will support heavy winds/waves and 
precipitation early-mid next week, especially for coastal and marine areas from the Seward 
Peninsula down to Bristol Bay.  Heavy precipitation will also spread through the middle of next 
week across southwestern and southern Alaska as energy works into that region with downstream low 
developments and inflow.

Kong