2026 Mid-Atlantic Severe Storm General Discussion

[87storms]

I missed out on the Friday storms in Frederick (was in DC/Harbor), so I'm all in.

[high risk]

2 hours ago, Nomz said:

RRFS simref eye candy. Outlier run, but it's fun to look at.

      In the 00Z suite, although they differ greatly on timing and coverage every CAM other than the NAM Nest has convection in our area at some point during Wednesday afternoon in a modestly favorable environment for severe.    I'd say that the initial Day 2 outlook will at a minimum keep us in a MRGL, and a SLGT isn't out of the question.    The only shot at severe is with the open warm sector storms, as whatever is on the front early Thursday will be weak.

[Nomz]

43 minutes ago, high risk said:

      In the 00Z suite, although they differ greatly on timing and coverage every CAM other than the NAM Nest has convection in our area at some point during Wednesday afternoon in a modestly favorable environment for severe.    I'd say that the initial Day 2 outlook will at a minimum keep us in a MRGL, and a SLGT isn't out of the question.    The only shot at severe is with the open warm sector storms, as whatever is on the front early Thursday will be weak.

I definitely think we go slight at some point. It's a bit of a balancing act with the NAM depiction vs some of the other models (thread the needle...). The NAM has a faster 700mb jet, which leads to a better EML over our area, but leaves subsidence in the exit region of the jet. The other models are much slower with the 700mb flow, so the EML is much weaker (<750 CAPE), but we are in the favorable area of the jet, so we get decent forcing for ascent and actual convection. 

[yoda]

4 hours ago, high risk said:

      In the 00Z suite, although they differ greatly on timing and coverage every CAM other than the NAM Nest has convection in our area at some point during Wednesday afternoon in a modestly favorable environment for severe.    I'd say that the initial Day 2 outlook will at a minimum keep us in a MRGL, and a SLGT isn't out of the question.    The only shot at severe is with the open warm sector storms, as whatever is on the front early Thursday will be weak.

Day 2 SLGT for all

 

[yoda]

Oh ok (morning AFD from LWX)

KEY MESSAGE 2...Severe thunderstorms are possible Wednesday
afternoon and evening as a strong cold front pushes through; a
significant drop in temperatures and gusty winds will accompany
the front Thursday.

A deep, digging, positively northern stream trough and its
associated strong cold front dive out of the Great Lakes
Wednesday. The cold front crosses the area late Wednesday
night into Thursday morning. Meanwhile, southern stream energy
will be lifting northward ahead of the boundary Wednesday
afternoon and evening. All of this creates a very complex severe
weather setup across the region. The latest update from the
Storm Prediction Center expanded the Slight Risk (level 2 out of
5) to include most of the area. However, it does come with some
caveats, which I`ll reiterate here. Primary among them is the
question of ongoing morning showers/convection, and the
potential impact that could have no destabilization during the
afternoon. As is typical, model guidance is very split on how
much instability is able to recover ahead of the pre-frontal
trough that will be the primary severe threat on the day. I do
think that seeing the latest CAM guidance in favor of 750-1250
J/kg of CAPE being able to develop has me a bit more concerned.
Assuming that we do get adequate CAPE, storms will fire along a
pre-frontal trough during the early afternoon hours across
eastern WV before moving east towards the metros during the
evening. The environment where storms may develop will be
impressive from a shear standpoint, with 40-50 kts of deep-layer
shear, and substantial amounts of Storm Relative Helicity (150+
m2/s2 0-1km, and 400+ m2/s2 in the 0-3 km layer). This is more
than favorable for supercell structures to develop, with
damaging winds, large hail, and even a tornado or two not out of
the question. Looking at the combination of shear and instability,
the STP is actually pretty impressive in model guidance. For
this reason, there is actually a CIG1 hatched area in our 2-5%
tornado probabilities across western MD and into the Potomac
Highlands. I wouldn`t even argue having with having that threat
even extended a bit further east along the MD/PA border in a
future update, but will let the 12z CAMs and machine learning
guidance come in for evaluation. Additionally, damaging winds,
large hail, and heavy rainfall will all be threats with any
storms that develop on Wednesday afternoon.

At any rate, Wednesday afternoon/evening is a day to watch
closely. Have your severe weather plans ready, in case you find
yourself needing to act on them. Continue to monitor the latest
forecasts from our office, as well as the Storm Prediction
Center, for the latest updates.

Confidence drops off significantly with the severe threat along
the immediate cold front given the projected timing late
evening into the overnight period. Even with that said, a gusty
line of showers could exist Wednesday night into Thursday as the
front pushes through. Would expect this to be more along the
lines of a gusty surge along the front (30-40 mph), followed by
increased synoptic winds shortly thereafter.