Day 1 Outlook Day 2 Outlook Day 3 Outlook Days 4-8 Outlook

Day 1 Outlook Convective Tornado
Hail Wind
Categorical Day1 1200Z Outlook
Images courtesy of the NWS Storm Prediction Center
 Forecast Discussion

ACUS01 KWNS 020550
SPC AC 020549

Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
1249 AM CDT Mon Oct 02 2023

Valid 021200Z - 031200Z


Thunderstorms, associated with large hail and wind damage, will be
possible this afternoon and evening across parts of the southern
Rockies and southern High Plains. Marginally severe storms will be
possible in parts of the central Rockies, and in parts of the
central and northern Plains.

...Southern Rockies/Southern High Plains...
A relatively high amplitude upper-level trough will move across the
western U.S. today. An associated mid-level jet will translate
northeastward into the southern and central Rockies. Ahead of the
system, low-level moisture advection and south-southeasterly upslope
flow will be maintained across the southern High Plains. As a
result, surface dewpoints are expected to be near 60 F in much of
eastern New Mexico and west Texas by afternoon. In response to
surface heating, moderate instability is forecast to develop by mid
afternoon throughout much of eastern New Mexico. Scattered
thunderstorms will likely develop in the higher terrain of central
and eastern New Mexico, gradually spreading northeastward into the
lower elevations. Several clusters of strong thunderstorms appear
likely to develop during the late afternoon and persist into the
early to mid evening.

RAP forecast soundings late this afternoon suggest that the most
favorable environment for severe storms will be in southeast New
Mexico, where MLCAPE is forecast to peak in the 2000 to 2500 J/kg
range. 0-6 km shear in this area is forecast to be in the 40 to 50
knot range, with an increase in shear likely as the eastern edge of
the mid-level jet moves into the region. This will be favorable for
supercells and organized storms. The instability, along with 700-500
mb lapse rates near 7.5 C/km, will make large hail likely with the
more intense cores. As the storms mature and move northeastward into
the lower elevations, a wind-damage threat is also expected to
materialize. The severe threat will first develop in eastern New
Mexico, but will spread northeastward into the southern High Plains
by early evening. A severe threat will also be possible in far West
Texas, but the threat will be increasingly marginal with southward
extent there.

...Central Rockies/Central and Northern Plains...
South-southwesterly mid-level flow will be in place today from the
central Rockies into the northern High Plains. At the surface, a low
will deepen in far southeast Wyoming. Moisture advection will
continue across much of the central and northern Plains, with
surface dewpoints remaining in the 50s F in most areas. As surface
temperatures warm this afternoon, a corridor of moderate instability
will develop across the central High Plains. Isolated to scattered
thunderstorms appear likely to form near this axis of instability
westward into the higher terrain of Colorado and Wyoming. The storms
will move north-northeastward into the central and northern High
Plains during the late afternoon and early evening. RAP forecast
soundings near the instability axis have MLCAPE peaking near 2000
J/kg, with 0-6 km shear in the 25 to 30 knot range. Mid-level lapse
rates near 7.5 C/km, combined with 0-3 km lapse rates increasing to
near 8.5 C/km, will be favorable for hail and strong winds
associated with organized multicells. The severe threat is expected
to be marginal, but should persist into the early to mid evening as
storm coverage gradually increases across the region.

..Broyles/Lyons.. 10/02/2023