Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
403 PM EDT Thu Mar 14 2024
Valid 00Z Fri Mar 15 2024 - 00Z Sun Mar 17 2024
...Heavy snow continues into tonight for the Central Rockies and adjacent
foothills/High Plains before gradually tapering off through Friday
morning...
...A long-duration event of mountain snow and lower-elevation rain
expected over the Four Corners region into the weekend...
...Severe thunderstorms and excessive rainfall expected to push
southeastward from the Southern Plains/Mississippi Valley Thursday evening
further into Texas and the Southeast region on Friday, continuing in Texas
Saturday...
...Mild weather continues from the central to the eastern U.S. going into
the weekend...
An amplifying upper-level trough/closed low continues to dig southward
into the western U.S. with a cold airmass settling in across the region.
Moisture flowing in ahead of the trough continues to lead to very heavy
snow over portions of the Central Rockies into the adjacent High Plains,
particularly along the Front Range. Snow rates upwards of 2"/hr will bring
several more inches of snow through tonight with storm total snowfall of
1-2 feet, locally as much as 2-4 feet. Gusty winds leading to blowing snow
will make travel very dangerous to impossible, with many of the local
interstates already closed. The snow should begin to gradually taper off
Thursday night and into Friday morning. Snowfall will then shift a bit to
the southwest over the Four Corners region as the upper-low settles in
overhead for the next couple of days. Waves of heavy snow will bring 12"+
of snowfall to the higher elevations of the regional mountain ranges into
this weekend. Lower elevations of the Four Corners will see a mix of rain
and snow, though any accumulations should remain limited, with rain also
spreading to the Desert Southwest. Some thunderstorms will also be
possible. Precipitation chances should continue at least through Saturday
evening.
To the east, widespread showers and thunderstorms will continue along and
head of a wavy cold front stretching from the Great Lakes/Midwest
southwestward through the Middle Mississippi Valley and into the Southern
Plains. The Storm Prediction Center has outlined an Enhanced Risk of
severe weather (level 3/5) from north Texas northeastward into eastern
Oklahoma, northwestern Arkansas, and southern Missouri through tonight
where the best combination of strong buoyancy and both low-level and
deep-layer wind shear are expected to lead to some supercell storms.
Storms will likely begin to cluster into the evening bringing more of a
large hail and damaging wind threat, though a few tornadoes will remain
possible with any remaining discrete/semi-discrete storms, including the
potential for a strong tornado. A broader Slight Risk (level 2/5) is in
place from the Southern Plains northeastward through the Middle
Mississippi Valley/Mid-South and into the Ohio Valley where some more
isolated instances of large hail, damaging winds, and a few tornadoes are
possible. In addition, a southerly influx of deep moisture from the Gulf
of Mexico along with storms clustering/motions increasingly parallel to
the frontal boundary will bring the threat of some very heavy downpours
and the risk of scattered instances of flash flooding, with a Slight Risk
of Excessive Rainfall (level 2/4) overlapping the Enhanced severe risk,
and continuing downstream into the Mid-South as storms move eastward
overnight.
The widespread showers and storms will continue as the front progresses
southeastward into the day Friday, with the coverage shifting downstream
into eastern Texas eastward through the Lower Mississippi Valley and into
the Tennessee Valley/Southeast. Surface ridging over the western Atlantic
and into the Gulf of Mexico will keep the supply of moisture flowing
northward plentiful, and may result in the boundary slowing somewhat as it
progresses, allowing for some storms producing heavy downpours
clustering/training along the front. Two Slight Risks of Excessive
Rainfall within a broad Marginal Risk over the region are in place where
the highest confidence currently exists in the combination of overlapping
upper-level energies/storm coverage and wet antecedent conditions for some
more instances of scattered flash flooding. This includes portions of
central/southern Texas into west-central Louisiana and northeastern
Mississippi into northern Alabama and northwestern Georgia. However,
complex mesoscale details lead to some uncertainty with the potential
these areas could further shift. Some additional severe thunderstorms are
also possible over central Texas, with another Slight Risk from the SPC in
place for the threat of some large hail and perhaps a tornado.
Showers and some thunderstorms will also spread into New England and the
Mid-Atlantic along the eastern portion of the front late Thursday and into
Friday with some areas of moderate to locally heavy rainfall possible.
Some wintry precipitation may mix in north of the front for portions of
northern New England. The front will continue southeastward Saturday
clearing New England and the Mid-Atlantic by Saturday morning and the
Southeast through the early afternoon, bringing an end to shower and storm
chances for these areas. However, the front will linger westward through
portions of Texas along and near the Gulf Coast westward through South
Texas. Yet another Slight Risk of Excessive Rainfall is in place as
widespread, heavy rain producing storms cluster along the boundary over
increasingly wet antecedent conditions where storms overlap with the prior
days' rainfall, continuing the threat for scattered flash flooding.
Elsewhere, a clipper system dropping southeastward from Canada into the
Upper Midwest/Great Lakes by Friday evening will bring some light to
moderate rain/snow shower chances into Saturday. Temperature-wise, above
average highs will continue to bring an early taste of Spring to most of
the central and eastern U.S. heading into the weekend. However, passing
frontal systems will bring temperatures down a bit from some of the more
greater anomalies seen today as temperatures for many locations were
upwards of 20-30 degrees above average, settling in closer to 5-10 degrees
above average. Highs will be below average over the Southwest/Four Corners
into the Great Basin and central/southern Rockies, as well as the adjacent
Plains with the upper-trough in place. The West Coast into the northern
tier of the West (Pacific Northwest/northern Great Basin/Northern Rockies)
will be away from the influence of the trough and see more mild, above
average conditions.
Putnam
Graphics available at
https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php