SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0652 AM CST Sat Feb 03 2024
Valid 031300Z - 041200Z
...NO SEVERE THUNDERSTORM AREAS FORECAST...
...SUMMARY...
Thunderstorms are possible today from the western Gulf Coast to
parts of the central Plains.
...Synopsis...
In mid/upper levels, a highly amplified pattern will persist over
the CONUS, with strong ridging from central Canada southeastward
across the Ohio Valley to the Southeast. The southern part of the
ridging will erode laterally as a strong shortwave trough --
initially located over parts of southern NM and west TX -- pivots
through cyclonic flow around a closed 500-mb low now near CAO. The
shortwave trough will strengthen and become the dominant closed
cyclone centered near SHV by the end of the period, along an
extensive larger-scale trough from the central Rockies to the
south-central Gulf.
At 11Z, the surface analysis showed a low in the CAO/DRT area,
stacked with the 500-mb center. An occluded front was drawn across
the northeastern TX Panhandle, southwestern OK, and western north
TX, with cold front over south-central TX into southern Coahuila. A
warm front was analyzed from the central to northwestern Gulf to
just off the upper TX Coast, becoming diffuse amongst convective
processes and outflows further northwest. An elongated area of low
pressure was drawn over the lower TX Coast. That coastal low should
shift northeastward to just offshore from the west-central part of
the LA coastline by 00Z, with cold front arching southward and
southwestward across the western Gulf. Meanwhile, the occluded low
should drift southeastward over the TX Panhandle, with the occluded
front reaching parts of northwest, north-central and southeast TX.
By 12Z tomorrow, the occluded/cold front should extend from the
western low over north-central TX, through another over southwestern
or south-central MS, across the MS Gulf Coast, arching to the
east-central and south-central Gulf.
...Western Gulf Coast...
An ongoing band of thunderstorms is moving across parts of the
middle/lower TX Coast, roughly between Baffin Bay and the Brazos
River. The northern part is impinging on outflow from an earlier
complex now over the Gulf south of BPT, which will limit severe-wind
potential, and the mode should preclude substantial hail. A few
strong gusts or instances of hail approaching severe limits may
occur with this activity before it moves offshore, with drying aloft
likely limiting development upshear. Substantial clouds and precip
should preclude favorable destabilization for overland severe
farther east. Sufficient shear and instability to support
supercells are possible over the open Gulf, but any associated
organized severe threat should remain away from land areas through
the end of the period.
...Northeast TX to east-central OK...
A band of widely scattered to scattered thunderstorms is expected to
develop over parts of east-central/southeastern OK and north TX east
of I-35 during midday to early afternoon. Activity should persist
through much of the afternoon, and shift slowly eastward, while
embedded cells move largely northward. Convection should occur
amidst diurnally/diabatically weakened MLCINH, behind an arc of
morning clouds/precip, and along the eastern rim of a midlevel dry
slot that provides preconvective clearing/heating opportunity.
Relatively low tops (near 400 mb) are expected for convection in
this region -- some of which should be surface-based.
Cold air aloft (around -22 to -24 deg C at 500 mb) will enable
sufficiently steep midlevel lapse rates, above residual moisture
with 50s F surface dewpoints, for a narrow plume of around 500-800
J/kg MLCAPE, despite cool (upper 50s to mid 60s F) inflow-layer
surface temperatures. Forecast wind profiles indicate weak deep/
effective shear and reversely curved hodographs with limited
positive SRH, though thermally enhanced low-level vorticity may
maximize in the corridor. The most vigorous cells may produce small
hail and strong gusts, and perhaps funnel clouds. Organized severe
potential appears too conditional and low to assign
outlook-threshold probabilities at this time.
..Edwards/Leitman.. 02/03/2024
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