US Day 3-7 Hazards Outlook
NWS Weather Prediction Center College Park MD
404 PM EDT Tue Sep 29 2020
 
Valid Friday October 02 2020 - Tuesday October 06 2020
 
Hazards:
- Heavy rain across portions of the Florida Peninsula, Fri-Tue, Oct 2-Oct 6.
- Heavy rain across portions of the Mid-Atlantic coast, Sun-Mon, Oct 4-Oct 5.
- Flooding occurring or imminent across portions of Florida and Louisiana.
- Much above normal temperatures across portions of northern California to southern Oregon, 
Fri-Tue, Oct 2-Oct 6.
- Much above normal temperatures across portions of central California, Fri, Oct 2.
- Much below normal temperatures across portions of the central Plains to the west of the Middle 
Mississippi Valley, Fri, Oct 2.
- Heavy precipitation across the Kenai Peninsula Borough, Fri-Sat, Oct 2-Oct 3.
- Heavy precipitation across portions of southern Alaska to the Alaska Panhandle, Sun-Mon, Oct 
4-Oct 5.
 
Detailed Summary:

During the medium range period (Friday, Oct 2 - Tuesday, Oct 6), a deep upper-level trough will 
remain a dominant feature over the central to eastern U.S., while upper-level ridging should 
continue to persist across the West.  Much of the western U.S. will see warmer than average 
temperatures through the period.  Parts of central California just inland from the Pacific coast 
will see one more day of high temperatures well into the 90s on Oct. 2. which is more than 12 
degrees above normal.  The ridge will gradually lose some strength by the weekend into early next 
week.  This will allow the warm temperatures to moderate some but portions of northern California 
to southern Oregon will continue to experience much above normal temperatures into early next week.

In contrast to the warmth in the West, much of the eastern two-thirds of the country will continue 
to witness below normal temperatures into early next week under a lingering longwave upper-level 
trough.  The associated chilly conditions over the central Plains should be moderating at the start 
of the medium range period but temperatures should still be around 12 degrees below normal for 
parts of the area.   Meanwhile, an Alberta clipper is forecast to dip into the central Plains 
during the weekend, bringing a reinforcing shot of chilly air back into the northern Plains.  This 
shot of chilly air will be short-lived however, as warmer than normal temperatures will quickly 
work their way into the Plains early next week behind a warm front.  A note about the Alberta 
clipper--some of the global models (the ECMWF in particular) have been indicating that the clipper 
could eventually evolve into a nor'easter for the Northeast.  This scenario has not been adopted 
for this chart for today but the situation will be monitored for the days to come.

Over the eastern U.S., a cold front will stall just off the East Coast and across southern Florida 
during much of the medium range period.  A continued feed of tropical moisture ahead of the front 
is forecast to keep a good chance of heavy rain for southern to eastern Florida through early next 
week.  The National Hurricane Center is also watching for the potential of a tropical cyclone 
developing and moving across the western Caribbean for that general time period.  In addition, 
there is increasing model support for a wave of low pressure to form along the front off the 
southeast U.S. coasts which may lead to further East Coast development as mentioned earlier.  
Regardless of the potential of East Coast cyclogenesis, heavy rain is likely near the Mid-Atlantic 
coast on Sunday and Monday.

Over Alaska, an active pattern will lead to fast and frequent energetic oceanic cyclones to push 
toward the southern part of the state through early next week.  Heavy precipitation will be likely 
across the Kenai Peninsula Borough on Friday and Saturday associated with and first cyclone, 
spreading eastward into the northern part of the Alaska Panhandle Sunday and Monday associated with 
the second cyclone.  The second cyclone could be potent enough to bring 50-knot winds to the 
coastal sections of southern Alaska on Sunday but a high wind area has not been depicted on the map 
at this time.  Farther north in interior Alaska, above normal temperatures are forecast, with highs 
approaching 60 degrees.

Kong