Severe Weather Center

Current Severe Weather Discussion Issued by the Storm Prediction Center

   SPC AC 130518

   Day 1 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   1218 AM CDT Mon Oct 13 2025

   Valid 131200Z - 141200Z

   ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS
   OF THE SOUTHWESTERN U.S....

   ...SUMMARY...
   Isolated, marginally severe hail and wind will be possible from the
   Four Corners and eastern Arizona to the Texas Trans-Pecos this
   afternoon into mid-evening. Locally damaging winds are possible
   later tonight along the south-central portion of coastal California.

   ...Southwestern U.S...

   Strong upper low is currently located along the WA Coast, shifting
   south in line with latest model guidance. This feature will continue
   to dig south as the primary midlevel speed max has yet to round the
   base of the trough. Left-exit region of the jet max will approach
   the central CA Coast after 14/06z which should encourage low-topped
   convection to move onshore after midnight. This activity could be
   locally strong with some gust potential as scattered convection
   advances inland in association with a pronounced cold front.
   Forecast soundings yield little more than 500 J/kg MLCAPE so any
   hail that forms with this activity should remain below severe
   levels.

   Downstream, deep south-southwesterly tropical feed across northwest
   Mexico into the southern Rockies will continue. Considerable amount
   of clouds and scattered precipitation should limit lapse rates and
   instability across this region. Even so, strong 0-6km shear does
   favor organized updrafts, especially during the afternoon/early
   evening when air mass will be most unstable. A low risk for
   hail/wind can be expected with the most robust convection, but
   widespread severe is not anticipated due to aforementioned poor
   lapse rates/modest buoyancy.

   ..Darrow/Weinman.. 10/13/2025

   CLICK TO GET <a href="/products/outlook/archive/2025/KWNSPTSDY1_202510131200.txt">WUUS01 PTSDY1</a> PRODUCT

   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1300Z
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Current Excessive Rainfall Discussion Issued by the Weather Prediction Center

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
858 PM EDT Sun Oct 12 2025
Day 1
Valid 01Z Mon Oct 13 2025 - 12Z Mon Oct 13 2025

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF
SOUTHERN ARIZONA AND THE COASTAL PLAIN OF THE CAROLINAS...

0100Z Excessive Rainfall Discussion Update...
Maintained the Slight Risk across parts of the Coastal Plain in
northeast SC and far southern NC -- essentially the area that has
already received 3-5+ inches in spots with banding persisting into
the area (pivoting very little). Rainfall rates are not as much of
a concern (limited deep-layer instability); however, considering
the rain already fallen along with the persistent banding, have
kept the Slight going.

Across AZ -- the latest observational and mesoanalysis trends,
along with recent ensemble exceedance probabilities (HREF and
RRFS), was able to trim a bit of the Slight Risk from parts of
central and southwest AZ, along with southwest NM.

Hurley

0830Z Excessive Rainfall Discussion...

...Southwest...
Deep moisture, fortified with the remnants of Tropical Cyclone
Raymond, will remain in place over portions of southern Arizona and
New Mexico. This morning's mesoanalysis shows PWs of 1.25-1.6
inches (3-4 std dev above normal) covering much of region. This
moisture along with increasing large-scale ascent, provided by an
approaching upper trough, will support another day of widespread
showers and storms capable of producing moderate to heavy amounts.
Maintained a Slight Risk covering much of southern Arizona and a
small portion of southwestern New Mexico. Both the HREF and RRFS
neighborhood probabilities indicate locally heavy amounts
exceeding 2 inches are likely within this region, with some
potential for amounts over 3 inches, especially across parts of
southern Arizona.

...Eastern Southern Carolina and Southeastern North Carolina...

The initial low of what is expected to evolve into a two feature
system is forecast to linger along the coast in the vicinity of the
North and South Carolina border today. Deeper moisture will remain
as well, with many of the 00Z models, including the globals,
showing a notable signal for locally heavy amounts developing later
today. While instability will be limited, deep saturation through
the column, and tall, skinny CAPEs are expected to support very
efficient rains, promoting heavy amounts. Both the HREF and RRFS
showing high probabilities for additional amounts over 3 inches
today across parts of the region. These amounts may raise runoff
concerns, especially for those areas where significant rains have
already occurred. Therefore a Marginal Risk was introduced for
areas where the hi-res ensembles indicate the heaviest amounts are
most likely to fall.

...Northern Mid Atlantic to Southern New England Coasts...

North of its parent, a secondary, triple-point low is forecast to
develop near the northern Mid Atlantic coast. There remains some
model uncertainty regarding if and to what degree this low will
become the dominant surface feature. Despite the differences,
there is broad agreement that strong, low level easterly winds, in
combination with strong mid-to-upper level forcing, will support
widespread precipitation from the northern Mid Atlantic coastal
region to central New England, with heavy amounts expected along
the coast. These heavy rains may compound what are likely to be
poor ground conditions attributed to ongoing coastal flooding.

Pereira

Day 1 threat area: <a href="https://www.wpc.ncep.noaa.gov/qpf/94epoints.txt"<u>www.wpc.ncep.noaa.gov/qpf/94epoints.txt</u></a>