US Day 3-7 Hazards Outlook
NWS Weather Prediction Center College Park MD
345 PM EDT Tue Nov 02 2021
 
Valid Friday November 05 2021 - Tuesday November 09 2021
 
Hazards:
- Heavy precipitation across portions of California, the Pacific Northwest, and the Northern Great 
Basin, Mon-Tue, Nov 8-Nov 9.
- Heavy rain across portions of the Southeast, Fri, Nov 5.
- Flooding occurring or imminent across portions of the Northeast.
- Flooding likely across portions of the Middle Mississippi Valley.
- High winds across portions of the Mid-Atlantic, Sat-Sun, Nov 6-Nov 7.
- Much below normal temperatures across portions of the Lower Mississippi Valley, the Tennessee 
Valley, the Mid-Atlantic, the Southern Appalachians, the Southeast, the Southern Plains, and the 
Ohio Valley, Fri-Sun, Nov 5-Nov 7.
 
Detailed Summary:

During this upcoming medium range period (Friday, November 5th - Tuesday, November 9th), much of 
the active weather will be focused across the western CONUS.  A series of storms rotating through 
eastern Pacific upper troughing will bring unsettled conditions to the Pacific Northwest, northern 
(and possibly central) California eastward across the northern and central Intermountain Region.  
But as is often the case, pinning down the timing of these systems and their associated 
precipitation with any confidence is challenging.  What seems to be agreed upon is that the 
features moving inland, at least through the weekend, will not be able to tap much deep moisture.  
Daily precipitation amounts in the Pacific Northwest should remain on the moderate side, with 
accumulating snow at higher elevations.  However, high rainfall rates are not expected.  Early next 
week, there are indications that a more robust storm will affect the region.  This system may be 
able to tap Pacific tropical moisture and is likely to have stronger onshore flow.  There is 
uncertainty with the timing/location of the heaviest precipitation, so opted for a broad hazard 
area covering northern/central California through western Oregon and Washington.  Precipitation is 
expected to spill out into the Intermountain Region, likely bringing some moderate to locally heavy 
snow to higher terrain.  Confidence was not high enough to place a hazard area in the Intermountain 
Region, however.

Farther east, model guidance is continuing to show the potential for low development off the 
Southeast coast this weekend associated with a fairly amplified southern stream upper trough.  The 
energy from this system will support an area of heavy rainfall from central/northern Florida 
Peninsula into southern Georgia on Friday, where locally up to a few inches are possible.  The bulk 
of the heaviest precipitation should then stay mostly offshore as the low strengthens and tracks 
north-northeastward.  The tight gradient between high pressure over New England and the developing 
cyclone will result in strong winds along coastal sections of South Carolina and the Outer Banks of 
North Carolina.  The highest winds are likely to be on Saturday, but may persist into Sunday 
depending on the exact track and strength of the low.  

Inland across the southern U.S. a combination of cool high pressure and light winds may bring the 
first frost/freeze of the season to parts of the mid-Mississippi Valley eastward through the 
Tennessee Valley and mid-Atlantic late this week into the weekend.  Overall, the temperatures are 
not significantly below normal (especially the lows), but opted to draw a hazard area given the 
potential harm to vegetation.

Across Alaska, overall itâ€ll likely be pretty quiet.  The forecast upper level flow will suppress 
the Pacific storm track south of a large part of the state, so significant precipitation is not 
likely.  Temperatures will remain above normal for the central/eastern interior sections into the 
weekend under southerly flow, but an overall cooling trend is expected as upper ridging builds 
north of the state and shuts off the southerly inflow.


Klein