Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
0253 PM CDT Sat Oct 31 2026

Valid 312000Z - 011200Z

...NO SEVERE THUNDERSTORM AREAS FORECAST...

...SUMMARY...
Organized severe thunderstorms are not forecast through tonight.

...20z Update...
Broad/diffluent southwesterly flow aloft continues to overspread the
Southwest. Visible satellite shows high clouds entering the region,
with filtered insolation resulting in some destabilization (200-300
J/kg MLCAPE) and cumulus development amid a moist boundary layer
across portions of southern AZ and across southern NV. Despite ample
shear that will increase throughout the remainder of the day, the
notably weak instability (perhaps peaking near 500 J/kg) will limit
the severe potential with any thunderstorm activity. Nonetheless,
general thunderstorm potential has been extended into parts of
southern NV.

Otherwise, the previous forecast remains on track. See the
discussion below for more details.

..Karstens.. 10/31/2026

.PREV DISCUSSION... /ISSUED 1126 AM CDT Sat Oct 31 2026/

...Synopsis and Discussion...
Downstream of weak mid-level troughing, isolated to scattered
thunderstorms will be possible through tonight across parts of the
lower MS Valley into the FL Panhandle and Peninsula as low-level
moisture gradually advances northward across these regions. Limited
overlap of sufficient instability and deep-layer shear to support
organized updrafts should preclude severe thunderstorms across these
areas.

Across the western CONUS, isolated convection appears possible
through the period across parts of central CA into the northern
Great Basin, and portions of southern/central AZ. Southwesterly
mid-level flow is forecast to strengthen across both of these
regions as upper troughing amplifies over the West Coast and as a
mid/upper-level subtropical jet overspreads the Southwest. However,
weak instability and modest mid-level lapse rates will likely hinder
severe thunderstorm potential through early Sunday morning.

Day 2 Convective Outlook  
NWS Storm Prediction Center Norman OK
1230 PM CDT Sat Oct 31 2026

Valid 011200Z - 021200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM SOUTHERN
ARIZONA ACROSS NEW MEXICO TO THE WESTERN TEXAS PANHANDLE...

...SUMMARY...
A few severe storms are anticipated from parts of southern Arizona
into New Mexico and the western Texas Panhandle Sunday into Sunday
night, with at least isolated damaging gusts and a couple of
tornadoes possible.

...Southern Rockies to southern High Plains...
A midlevel trough just off the northern CA coast will progress
inland to the Four Corners by early Monday.  This will be preceded
by the rapid northeastward ejection of a subtropical speed max now
near 27 N and 128 W.  A surface cyclone is expected to consolidate
in the lee of the CO Rockies by Sunday night with increasing
low-level mass response and northward advection of low-level
moisture from TX to KS.

The lead speed max will cross southern AZ Sunday afternoon and NM
Sunday night.  Cloud cover and precipitation the past few days, plus
an expansive swath of midlevel moisture in advance of the
subtropical wave, will tend to limit lapse rates across the elevated
mixed layer source region.  However, unusually moist profiles will
also contribute to at least weak buoyancy into the higher terrain
from southern AZ into NM, and the buoyancy is unlikely to be tied
very strongly to the diurnal heating cycle.  As such, there will be
the potential for bands of convection to accompany the ejecting
speed max Sunday into Sunday night, both across AZ and especially
NM.  Wind profiles will be quite strong with long hodographs and
weakly buoyant, moist profiles, similar to cool season severe events
in the Southeast.  Will expand the MRGL risk for embedded supercells
and/or bowing segments capable of producing occasional severe
outflow gusts and a couple of tornadoes, and a SLGT risk upgrade is
a possibility in later updates across NM.

..Thompson.. 10/31/2026

Day 3 Convective Outlook  
NWS Storm Prediction Center Norman OK
0229 PM CDT Sat Oct 31 2026

Valid 021200Z - 031200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM
CENTRAL/EASTERN KANSAS ACROSS OKLAHOMA INTO NORTH TEXAS...

...SUMMARY...
Scattered severe storms may develop across parts of the central to
southern Plains Monday from late afternoon into the evening, with
damaging wind gusts and a few tornadoes the main threats.

...Central/southern Plains...
A lead speed max is expected to eject quickly northeastward from the
central Plains to the upper MS Valley as an initial lee cyclone
likewise moves northeastward from northeast CO to southwest MN and
weakens gradually.  Secondary cyclogenesis is then expected across
KS in advance of the primary shortwave trough progressing eastward
from the southern Rockies to the southern/central Plains.  The
secondary cyclone in KS will help maintain a 40-50 kt southerly
low-level jet through Monday afternoon/evening from eastern KS into
eastern OK, with associated northward advection of mid 60s
boundary-layer dewpoints in the warm sector.

Midlevel lapse rates will be limited by prior days
clouds/precipitation across the upstream source region, but
convective inhibition will also be weak.  The aforementioned
low-level moisture, in combination with daytime heating in cloud
breaks associated with the midlevel dry slot, will support MLCAPE in
the 1000-1500 J/kg range.  Scattered thunderstorm development
appears probable by mid-late afternoon from just east of the KS
triple point southward along the dry line/Pacific cold front into
western OK.  Deep-layer vertical shear and forcing for ascent will
favor a mix of supercells and line segments capable of producing
severe outflow gusts and a few tornadoes, as well as isolated large
hail initially.  Storms should tend to evolve into more linear
structures into Monday night with a continued threat for occasional
wind damage and/or a couple of tornadoes with embedded circulations.

..Thompson.. 10/31/2026