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Archives for the SPC Convective Outlook are updated daily (approximately) with a live map at the beginning of each article. Follow the link at the end of the article to check for current updates on the NOAA/NWS Storm Prediction Center website. Also, see Archives for Chicago's hourly weather data on CARDINAL NEWS Magazine.


Friday, February 2, 2024

SPC Feb 2, 2024 1300 UTC Day 1 Convective Outlook

LIVE MAP (ABOVE) ... SPC 1300Z Day 1 Outlook

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0653 AM CST Fri Feb 02 2024

Valid 021300Z - 031200Z


Severe hail, damaging gusts and a tornado or two are possible over
parts of the southern Plains, from late afternoon into this evening.

A highly amplified, somewhat progressive mid/upper-level pattern is
forecast through the period, with ridging shifting slowly eastward
across central Canada and the Mississippi Valley. Upstream, height
falls will spread across the Rockies and Great Plains States. The
most convectively impactful feature will be a basal shortwave trough
-- with several associated vorticity maxima -- initially evident in
moisture-channel imagery over portions of southern CA, the lower
Colorado River Valley, and northwestern MX. The trough should shift
eastward and strengthen, extending from the Four Corners area across
central/southern NM past ELP and over Chihuahua around 00Z. By 12Z,
a closed 500-mb low should develop over northeastern NM, with the
trough south-southeastward across the Llano Estacado and Permian
Basin to Coahuila.

At 11Z, surface analysis showed lee troughing over eastern parts of
CO and NM, with a few weak/attached lows, as well as pockets of 60s
F surface dewpoints reaching as far north as the SAT-AUS region. A
diffuse Pacific cold front was apparent over east-central NM and far
west TX, and should sharpen through the day as it crosses west TX.
A dryline was drawn from northwest TX southwestward over the Permian
Basin, then south-southeastward into higher terrain of northern
Coahuila. This dryline should mix eastward through this afternoon
to the Edwards Plateau on the south side, and move little on the
north side. The lee trough should strengthen throughout the period,
with cyclogenesis expected overnight in the area from the
northwestern TX Panhandle to southeastern CO. The Pacific front to
its south and southeast should overtake the dryline and shift
eastward from west TX into central and south TX tonight.

Episodes of strong-severe thunderstorms are expected to cross the
outlook area starting this afternoon along/ahead of the dryline --
initially moving roughly northward over in the northwest TX/eastern
Panhandle/western OK region. Isolated severe hail, damaging gusts
and potential for a brief tornado exists with this activity.

A later but more-substantial severe threat is apparent across parts
of northwest, central and southwest TX, east of
late-afternoon/early-evening development areas along:
1. The dryline,
2. The Pacific front, and
3. Eastern slopes of the Serranias del Burro of Coahuila leading
down to the Rio Grande.
Supercellular and bowing/quasi-linear modes are possible in and near
the "slight" area, offering sporadic severe hail, isolated severe
gusts and potential for a tornado or two. Some hail may exceed 2
inches in diameter from supercell(s) in the first few hours of the
convective cycle over parts of south TX (southern Hill Country
southward). In that area, the most-favorable combination of steep
deep-layer lapse rates, inflow-layer moisture, and long hodographs
is expected.

Large-scale lift will strengthen through tonight across much of the
southern Plains -- under the influences of low-level warm advection
and midlevel DCVA. Also, as a 125-160-kt 250-mb jet extends inland
across southern CA and northwestern MX -- behind the mid/upper
trough -- its left-exit region and associated lift aloft should
spread this evening and overnight across parts of central/south TX,
where the steepest midlevel lapse rates (exceeding 7 deg C/km) are
expected. These influences will extend atop a moistening and
diurnally destabilizing boundary layer with surface dewpoints in the
50s F over northwest TX and OK, and 60s in the Edwards Plateau and
Hill Country southward to the Rio Grande. Adequate deep-layer
instability/buoyancy for surface-based convection is expected on
either side of the dryline today, and along/ahead of the Pacific
front tonight. Peak/preconvective MLCAPE should reach around
1000-1500 J/kg in a narrow, south-north corridor ahead of the
dryline, diminishing eastward toward east TX. Low-level shear may
be stronger over northern parts of the outlook, but with greater
deep shear southward toward the more-intense mid/upper winds.

..Edwards/Leitman.. 02/02/2024

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CHICAGO UTC-5 during CDT (Daylight Savings Time, e.g., summer)