Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
1128 AM CDT Thu Oct 30 2025

Valid 301630Z - 311200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE MID-ATLANTIC/DELMARVA...

...SUMMARY...
Thunderstorms with an isolated damaging wind/tornado threat may
occur across parts of the Mid-Atlantic/Delmarva vicinity today.

...Mid-Atlantic/Delmarva...
A closed mid/upper-level low over the upper OH Valley will translate
northeastward into the Mid-Atlantic and NY today, with a surface
cold front expected to continue moving eastward across eastern NC/VA
and the southern Mid-Atlantic. As a weak surface low develops
northeastward into PA this afternoon/evening, a warm front will
likewise attempt to lift northward across eastern PA and NJ. Cloud
cover remains prevalent across the warm sector, with only filtered
diurnal heating occurring in the presence of modest mid-level lapse
rates (reference 12Z IAD sounding). This will temper the degree of
surface-based instability which can develop this afternoon, with a
notable mid-level dry slot also overspreading the southern
Mid-Atlantic per recent water vapor satellite imagery.

Even with these thermodynamic limitations, it still appears possible
that isolated showers and thunderstorms could develop and spread
quickly north-northeastward this afternoon across parts of the
Delmarva vicinity into southeast PA and NJ. Strong deep-layer shear
noted in recent VWPs from KDOX/KDIX may support organized updrafts
with some risk for occasional damaging winds given the strength of
the low/mid-level southerly flow. While low-level winds will have a
tendency to veer to southwesterly with time this afternoon/evening,
a brief tornado appears possible with any sustained updraft that can
interact with the northward-advancing warm front. The overall severe
threat will likely remain constrained by the poor thermodynamic
environment. The primary change made with this update was to trim
severe probabilities given the eastward/northward progression of the
cold front and mid-level dry slot.

..Gleason/Bentley.. 10/30/2025