US Day 3-7 Hazards Outlook
NWS Weather Prediction Center College Park MD
307 PM EST Fri Nov 25 2022
Valid Monday November 28 2022 - Friday December 02 2022
- Heavy rain across portions of the Southeast, the Southern Appalachians, the Lower Mississippi
Valley, the Southern Plains, and the Tennessee Valley, Tue-Wed, Nov 29-Nov 30.
- Heavy snow across portions of the Pacific Northwest and the Northern Great Basin, Tue-Wed, Nov
- Heavy snow across portions of the Northern Rockies and the Northern Great Basin, Wed-Thu, Nov
- Severe weather across portions of the Lower Mississippi Valley, the Tennessee Valley, the Middle
Mississippi Valley, the Southeast, the Southern Plains, and the Ohio Valley, Tue, Nov 29.
- Flooding occurring or imminent across portions of the Southeast.
- High winds across portions of the Southern Rockies, the Southern Plains, and the Southwest, Tue,
- High winds across portions of the Northeast and the Great Lakes, Wed, Nov 30.
- Much below normal temperatures across portions of the Pacific Northwest, the Northern Rockies,
the Northern Great Basin, and the Northern Plains, Fri, Dec 2.
- High winds across portions of the Alaska Panhandle and mainland Alaska, Tue-Wed, Nov 29-Nov 30.
- Much below normal temperatures across portions of the Alaska Panhandle and mainland Alaska,
Tue-Thu, Nov 29-Dec 1.
A deep trough traversing the Nation during the medium range period (Monday, November 28 to Friday,
December 2) followed by a second trough and reinforcing shot of arctic air over the Northwest will
be responsible for several areas of potentially hazardous weather. As this trough continues to dig
across the Northwest and Intermountain West at the beginning of the week, light to moderate snow is
possible across the Oregon Cascades, northern/central Rockies and Great Basin. Strong southwesterly
winds are anticipated to develop across parts of the Southwest, Southern Rockies, and southern High
Plains on Tuesday as the upper trough sharpens and a potent upper-level jet develops over the
region (even though recent trends have resulted in a weaker setup). Downslope enhancement may aid
in maximum wind gusts exceeding 50 mph mixing to the surface, hence the high winds area on the
hazards chart. As this same system ejects into the central U.S. by Wednesday morning, strong
southerly flow ahead of the approaching cold front should aid in enough instability to create the
threat of severe weather beginning on Tuesday and extending into early Wednesday throughout the
Lower Mississippi Valley. SPC has issued a 30% chance of severe thunderstorms over parts of this
region, with the threat extending into the ArkLaTex and points southward to the Upper Texas Gulf
Coast and northward to western Tennessee. Heavy rain is also possible from the Lower Mississippi
Valley to the southern Appalachians into midweek. Probabilities for over an inch of rainfall have
increased throughout the highlighted region and guidance has become more in line with the potential
for several rounds of showers/storms capable of containing intense rainfall rates. Additionally,
the threat of heavy snow exists on the northern periphery of this system from the central High
Plains to the Upper Midwest and Upper Great Lakes (specifically the U.P. of Michigan), but there
still remains too much uncertainty regarding moisture availability to add a highlighted heavy snow
area. Gusty winds are more likely however, as a rapidly strengthening low pressure system swings
northward into the Great Lakes. The strong pressure gradient depicted by most guidance would
support scattered 50+ mph maximum wind gusts across the Great Lakes region late Wednesday into
A separate storm system set to enter the Northwest by midweek is likely to have sufficient moisture
transport and lead to another round of heavy snow across the Cascades and far northern Rockies
beginning as early as Tuesday night throughout western Washington. PWSSI is already depicting 40%+
chances for moderate impacts over the high terrain as a colder airmass in place may support more
widespread snowfall into the lowlands as well. Snow could reach to sea level depending on the
eventual track of the surface low, so residents within/near urban regions should keep an eye on the
forecast heading into next week. Probabilities for at least 8 inches of snow continue to be modest
over parts of northern Idaho and far western Montana as Pacific moisture pushes inland. The arctic
airmass sinking southward from Canada will enter into the far northern Great Basin and northern
Montana on Thursday, with even colder air expected by Friday. Low temperatures are anticipated to
dip to around 15 to 20 degrees below average and settle into the single digits/subzero readings for
most places overnight. Fresh snow cover could allow for even colder minimum temperatures.
Looking towards the end of the forecast period (Friday, December 2), guidance continues to
highlight returning moisture into the Tennessee Valley and the potential for heavy rainfall as a
frontal boundary approaches from the West. There remains notable spread that inhibits enough
confidence to hoist a heavy rain hazard at this time, but should forecast guidance remain
consistent there will likely be one added in the near future.
Overall, upper-level ridging is expected to build into western Alaska while troughing extends from
northwest Canada to the Alaskan Panhandle through the start of December. As a result, an area of
low pressure is expected to slide off the coast of the southern Panhandle on Tuesday along with
building strong high pressure (and temperatures around 20 degrees below average) over Interior
Alaska and the Yukon. Trends have continued to suppress the aforementioned low pressure to the
south and limit or completely eliminate and hazardous precipitation over the Panhandle. Regardless,
strong northerly gap winds are possible on Tuesday and Wednesday behind the system over the
northern and central Panhandle due to the strong and cold high pressure system over the Interior.
The strong winds will also accompany temperatures around 20 to 25 degrees below average over the
Panhandle between Tuesday and Thursday, leading to wind chills well below zero.
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