US Day 3-7 Hazards Outlook
NWS Weather Prediction Center College Park MD
351 PM EDT Mon Oct 11 2021
 
Valid Thursday October 14 2021 - Monday October 18 2021
 
Hazards:
- Heavy rain across portions of the Middle Mississippi Valley, the Lower Mississippi Valley, and 
the Southern Plains, Thu, Oct 14.
- Heavy rain across portions of the Middle Mississippi Valley, the Lower Mississippi Valley, the 
Ohio Valley, and the Tennessee Valley, Fri, Oct 15.
- Heavy rain across portions of the Northeast and the Great Lakes, Sat, Oct 16.
- Flooding possible across portions of the Southern Plains.
- Flooding occurring or imminent across portions of the Southeast.
- Much below normal temperatures across portions of the Central Plains, the Central Great Basin, 
the Northern Plains, the Northern Rockies, the Central Rockies, and the Northern Great Basin, Thu, 
Oct 14.
- Heavy precipitation across portions of the Alaska Panhandle and mainland Alaska, Mon, Oct 18.
- High winds across portions of mainland Alaska and the Aleutians, Sat-Sun, Oct 16-Oct 17.
 
Detailed Summary:

The medium range forecast period (Thursday, October 14th - Monday, October 18th) will feature heavy 
rain in the central and eastern CONUS, a continued cool spell for the Rockies and Intermountain 
West, as well as high winds and heavy precipitation for parts of Alaska. An amplified upper-level 
trough will eject a low pressure system from the Rockies over the Great Plains on Wednesday. This 
system will go on to produce moderate to heavy rainfall and thunderstorms for much of the plains 
and Mississippi Valley midweek before shifting its focus to the Lower/Middle Mississippi Valley and 
eventually the Northeast this weekend. A new area of low pressure will form over the Southern 
Plains on Thursday, which is expected to help focus the heavy rainfall threat to parts of northeast 
Texas, eastern Oklahoma, western Arkansas and southern Missouri. Much below normal temperatures are 
expected to continue over much of the Rockies and Intermountain West on Thursday due to the 
persistence of a cooler continental/mountain airmass. The heavy rain threat shifts eastward over 
parts of the Middle Mississippi Valley and Midwest on Friday. Meanwhile, high pressure will build 
across much of the West. Increased instability over southeastern Missouri may lead to isolated 
thunderstorms and higher rain rates for the area, which would contribute to the heavy rain threat 
that day. The development of another area of low pressure over the Ohio Valley on Saturday will 
lead to increased moisture advection across much of the Northeast and the chance for heavy rain 
over parts of upstate New York and Vermont. The 00z CMC seems to be the only outlier when it comes 
to the timing of the upper-level trough's progression across the central U.S. this weekend.

In Alaska, a sequence of low pressure systems will bring the threat of high winds to the Aleutians 
through the medium range period. The first system will cross the Aleutians on Friday and enter the 
Gulf by Saturday before dissipating. This system will bring some low elevation rain and high 
elevation snow to the southeast coast this weekend. The next system will follow a similar 
trajectory, but will be more potent as the upper-level energy amplifies over the Gulf. High winds 
are likely for much of the Aleutians this weekend as the system crosses the region. Impacts will be 
felt across the Panhandle by next Monday as the now strengthened system produces heavy 
precipitation across the area. There's reasonable model agreement on the magnitude of the 
precipitation threat, but some discrepancy exists, particularly with the 00z CMC, on the areal 
coverage of the precipitation.

Kebede