SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0157 PM CST Fri Feb 02 2024
Valid 022000Z - 031200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM WESTERN NORTH
TEXAS AND FAR SOUTHWEST OK INTO THE TEXAS HILL COUNTRY THIS
AFTERNOON THROUGH TONIGHT...
...SUMMARY...
Local severe weather potential, mainly in the form of hail, will
affect portions of the southern Plains from late afternoon into this
evening.
...20Z Update...
...Southern Plains...
Showers and thunderstorms have developed in an arc from the TX
Panhandle across southwest OK and into north-central TX amid the
broad ascent and warm-air advection associated with the approaching
wave. These elevated storms will likely continue to move
northeastward/eastward throughout the afternoon and evening, but
with limited severe potential given their elevated character and
displacement east of the better buoyancy.
Additional thunderstorms are anticipated along the Pacific cold
front as it moves eastward this afternoon and evening. The airmass
ahead of this front will continue to destabilize as the low-level
clouds erode and low-level moisture advection continues. The
strongest storms still appear most likely from far northwest
TX/southwest OK through the TX Hill Country this afternoon and
evening, with large hail as the primary threat. Bowing line segments
could produce some damaging gusts as well. Overall thunderstorms
coverage is still expected to increase over time and with eastern
extent into central OK and north-central/central TX this evening.
However, prevailing low-level stability over this region suggest
mostly elevated storms with the potential for hail, but a damaging
gust or two may still be able to reach the surface. Farther south
(into southeast TX), damaging gusts appear to be main hazard as the
front encounters more favorable low-level moisture and related
buoyancy.
..Mosier.. 02/02/2024
.PREV DISCUSSION... /ISSUED 1029 AM CST Fri Feb 02 2024/
...Synopsis...
A highly amplified upper flow pattern will continue across the U.S.
today. While a trough will continue crossing the eastern states and
a second affects the Pacific Northwest, the primary feature with
respect to convective weather will be a trough/evolving upper low
advancing east-southeastward across the Desert Southwest. Ascent in
advance of this feature -- and the associated left exit region of a
160 kt northwesterly upper-level jet -- will continue spreading
into/across the southern Plains through the period.
At the surface, a Pacific cold front -- associated with the
aforementioned southwestern U.S. upper trough -- will shift out of
eastern New Mexico and far West Texas into lower elevations of the
southern Plains today and tonight, in tandem with an increase in
thunderstorms across the region.
...Southern Plains...
Morning RAOBS indicate stout capping across the southern Plains
region, with expansive low clouds/stratus per visible satellite
imagery due to a partially modified Gulf boundary-layer airmass
streaming northwestward beneath the inversion. The low cloudiness
-- and increasing convection across the area with time -- will limit
potential for surface-based destabilization in most areas,
particularly with eastward extent.
With that said, some erosion of the low clouds is ongoing into
portions of the Big Country region of Texas, with clear skies to the
west -- i.e. portions of the south Plains and the Transpecos region.
Resulting insolation ahead of the advancing front will likely
permit eventual/afternoon thunderstorm development across the Big
Country and Concho Valley region, which is then expected to spread
northeastward toward western North Texas with time. Storms may also
develop by this evening over the higher terrain just west of the
lower Rio Grande Valley, and adjacent portions of the Edwards
Plateau.
Despite the somewhat cool, and only modestly moist boundary layer
expected to persist across the eastern half of the southern Plains,
steep lapse rates aloft will contribute to ample CAPE aloft,
supporting locally vigorous updrafts. Storm intensity will be aided
by favorably strong/veering flow with height as increasing
southwesterly mid-level flow spreads eastward across the southern
Plains. As a result, isolated rotating storms will likely evolve,
with the greatest potential for surface-based severe risk including
damaging winds likely to remain across western portions of the SLGT
risk area. Into this evening, as storms continue to increase in
coverage and spread eastward across central parts of the southern
Plains, and perhaps initiate farther south toward the Rio Grande
Valley, risk should transition to primarily hail, as convection
should largely remain elevated.
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