…Historic winter storm to bring more heavy snow and blizzard conditions
to portions of Colorado, New Mexico, and the Oklahoma and Texas Panhandle
through tonight…
…Showers and thunderstorms will bring the threat of flash flooding to
the southern Plains through tonight, and into the Lower Mississippi Valley
and Mid-South for Saturday and Saturday night…
…Above average temperatures continue for much of the country this
weekend…
…Atmospheric river to arrive across the Pacific Northwest on Sunday with
heavy coastal rains and high elevation snowfall…
A historic winter storm with very heavy snowfall will continue to impact
the southern Rockies and portions of the immediate southern High Plains
going through tonight, including areas of Colorado, New Mexico and small
parts of the Oklahoma and Texas Panhandle region. Going through tonight,
areas of eastern Colorado will see the heaviest additional snowfall totals
with locally over a foot of new snow expected. This will be supported by
snowfall rates that will occasionally fall at 1 to 2 inches/hour. Strong
and gusty winds accompanying the snow will also continue to promote
blizzard conditions and especially over northeast New Mexico where
Blizzard Warnings remain in effect. As a result, travel will continue to
be very difficult to impossible, and especially with numerous road
closures already locally in place. The very slow-moving area of low
pressure responsible for this historic, multi-day winter storm will begin
to advance northeast out across the central Plains this weekend, and this
will allow for the snow to begin tapering off on Saturday.
Meanwhile to the east, on the warm side of the system, the influx of Gulf
of Mexico moisture and increased instability will to lead to widespread
showers and thunderstorms producing very heavy rain over the next couple
of days. This will cover much of the southern Plains region going through
tonight along and ahead of an eastward moving cold front. A Slight Risk of
excessive rainfall (level 2/4) covers much of Oklahoma down through
northern and central Texas where areas of heavy rain over locally
saturated ground may lead to scattered instances of flash flooding.
However, as the storm system ejects farther out over the Plains, the
excessive rainfall threat will shift off to the east and move into the
Lower Mississippi Valley and Mid-South going through Saturday and Saturday
night. The same cold front will focus a north to south axis of heavy
showers and thunderstorms across this region. Some of the rains especially
over central to northeast Louisiana may become particularly focused and
with some areas still moist from heavy rains earlier in the week, these
additional heavy rains may scattered to numerous areas of flash flooding.
A Slight Risk of excessive rainfall (level 2/4) covers much of the Lower
Mississippi Valley to Mid-South region, but a targeted Moderate Risk
(level 3/4) has been depicted for central to northeast LA where several
inches of rain will be possible. Some of these rains are forecast to
linger into Sunday as the cold front continues to press eastward, but
areas farther east across the Tennessee Valley that see moderate to heavy
rain will greatly benefit from these rains given the extremely dry weather
that has been in place over the last month.
Temperature-wise, most of the country will continue to see above average
temperatures going into the weekend. Many areas of the northern Plains and
Midwest south down through the Mid-South and Gulf Coast states will still
be seeing high temperatures on Saturday and Sunday that will be 10 to 15
degrees above normal for this time of the year. This will include high
temperatures well into the 70s and 80s across the South where there may be
a few record high temperatures recorded. Mild conditions will be in place
along the East Coast, with some exception to the interior of the
Mid-Atlantic and the southern Appalachians where the arrival of clouds and
rain by Sunday will keep temperatures cooler and closer to normal. The
aforementioned southern Rockies and High Plains area where the ongoing
winter storm is focused should see high temperatures as much as 10 to 20
degrees below average on Saturday, with some moderation expected on Sunday.
By Sunday, a new storm system is forecast to impact the Pacific Northwest
and this will bring atmospheric river conditions to the region. This
influx of Pacific moisture will bring heavy rains to the coastal ranges of
Washington and Oregon, and some higher elevation snowfall for the
Cascades. The heaviest rains should be focused over the Olympic Peninsula
where a few inches of rain will be possible.
Orrison
Graphics available at
https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php
