2025 Severe Weather General Discussion

[George BM]

MCD out for the immediate region.

 

Mesoscale Discussion 1044 NWS Storm Prediction Center Norman OK 0249 PM CDT Fri May 30 2025 Areas affected...Parts of eastern VA...MD...DE...northeastern NC...and far southeastern PA Concerning...Severe potential...Watch likely Valid 301949Z - 302145Z Probability of Watch Issuance...80 percent SUMMARY...The risk of damaging wind gusts and a few tornadoes will increase in the 22Z-00Z time frame. A watch will likely be issued for parts of the area within an hour or two. DISCUSSION...Latest surface analysis shows a surface low over northern WV, with a quasi-warm front extending eastward across MD into southern NJ. Along/south of the front, diurnal heating within cloud breaks and lower/middle 60s dewpoints are contributing to around 1500 J/kg MLCAPE. As storms spread/develop eastward into the destabilizing air mass, 40-50 kt of effective shear should favor gradual intensification/organization into semi-discrete clusters and supercells. Enhanced clockwise hodograph curvature (around 150 m2/s2 effective SRH) ahead of the east-northeastward-moving surface low will support the potential for a few tornadoes (along with locally damaging wind gusts) with the more organized supercells that evolve. A watch is likely for parts of the area within an hour or two. ..Weinman/Smith.. 05/30/2025

[Rhino16]

Not many changes at 20z, just some adjustments north and “trimming”.
rest of outlook is same as previous.

...20Z Update...
   The primary change to the Day 1 Convective Outlook was to slightly
   expand severe probabilities farther north in NJ to account for
   placement of stronger storms likely preceding the surface low track.
   The western bounds of severe probabilities were also trimmed to
   account for the passage of the surface low and surface cold front.
   Otherwise, the previous forecast (see below) remains on track.

   ..Squitieri.. 05/30/2025

 

[Chinook]

42 minutes ago, SnowenOutThere said:

Correct me if I'm wrong but that would be a line of at least quasi-supercellular activity?

the short term forecasts have at least 45 kt of shear (effective) over mid Virginia, so sure.

[MN Transplant]

18z HRRR still throwing out severe-level winds on the backside as the low is passing by.

[Interstate]

1 hour ago, WxUSAF said:

Radar seems ahead of schedule relative to meso models 

They look like they are dissipating as they move NE... Still looks like a couple of hours off until they hit the Metro areas.

[GATECH]

Quick shower, temp dropped from 83 to 75.  Sun trying to poke out again.  Hard pass on severe after two weeks ago here.

[87storms]

Not sure how Frederick will do, but it’s humid out…that’s for sure.

[yoda]

One of the best written AFD from LWX 

26 27 28

---

032
FXUS61 KLWX 302011
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
411 PM EDT Fri May 30 2025

.SYNOPSIS...
Low pressure will track through the area this evening, before
departing off to our northeast tomorrow. High pressure will
build into the area on Sunday, and remain in control over the
area through much of the upcoming week.

&&

.NEAR TERM /THROUGH TONIGHT/...
Synoptic overview: Current water vapor imagery shows a vigorous
upper low centered off to our west over OH/WV. Moisture
continues to stream northward into the area at in advance of
this disturbance. Further to the west, a prominent mid-level dry
slot is wrapping into the system from the southwest, extending
from the Tennessee Valley into West Virginia. A broken,
disorganized zone of showers is ongoing within the moist
advection regime at low to mid levels, and currently extends
from the central Virginia Piedmont northwestward to western
Maryland. While some intensification of this activity can`t be
ruled out, the expectation is for it to remain just showers.
Further west, a more intense band of showers and thunderstorms
has developed within the mid-level dry slot, and extends
northward from southwest Virginia into central West Virginia.
This area of storms is expected to intensify further as it
tracks eastward into our area later this afternoon into this
evening.

As we move forward in time, the entire system will continue to
gradually translate eastward. In any given location, on and off
showers will be possible for a few hours, before a more focused
zone of showers and thunderstorms passes through during a  1-2
hour window. Those stronger storms will reach far western
portions of the forecast area over the next 1-2 hours, the Blue
Ridge by around 5-7 PM, and then the I-95 corridor around 7-10
PM. These storms will produce the greatest threat for severe
thunderstorms, and may also result in some isolated instances of
flash flooding.

Later tonight a surface low associated with the system will
start to deepen overhead as it tracks along a frontal boundary
which will extend east-northeastward across northern MD and
southern PA. As this occurs, a secondary deformation driven area
of precipitation will develop on the backside of the low. This
may lead to an additional 2-4 hour period of rain later tonight,
with embedded moderate to heavy rain. This activity should be
strongest in the vicinity of the front across northern Maryland.
An overview of various weather hazards follows...

Flash Flooding: There has a been a pronounced northwestward
trend in the track of the surface low and the resultant axis of
anticipated heaviest rainfall over the past 12-24 hours. While
there is still a non-zero chance for flooding, the magnitude of
the threat for flooding locally appears to be shifting northward
and trending downward in magnitude. All locations should
experience a brief period of heavy rainfall in association with
the thunderstorms in the north- south oriented band currently
over West Virginia. Given recent heavy rainfall, it won`t take
much to cause flooding issues. 1 hour Flash Flood guidance is
actually below one inch across much of the area, and under 1.5
inches over the vast majority of the forecast area. While the
trend has been downward in expected rainfall totals, even brief
periods of heavy rainfall may lead to isolated instances of
flooding as the storms move through. Any supercells could
locally enhance rainfall rates beyond what one might expect with
PWATs around 1.5 inches. The second round of rainfall later
tonight should be most intense across northern Maryland, where
the overall threat for flooding will be maximized. Overall,
totals are expected to be around 1-3 inches to north of I-70,
with localized higher totals in excess of 3 inches. Further
south, totals may average less than one inch, but localized
higher totals that could cause flash flooding issues may still
be possible. A Flood Watch for flash flooding remains in effect
for the entire area through tonight.

Severe Thunderstorms: Model soundings show an environment
characterized by deep moisture, with nearly saturated profiles.
MLCAPE is expected to increase to around 1000-1500 J/kg across
much of the area over the next few hours. Deep layer shear in
also increasing from the south and west, with effective bulk
shear anticipated to increase to around 40-60 knots. Low-level
shear on the other hand is much weaker, with only around 10-20
knots of southerly flow at 850 hPa. Strong deep layer shear
should result in the development of supercells.

In terms of individual threats, damaging wind potential may be a
bit lower than one might expect with supercells around. DCAPE is
very low (around 200-400 J/kg), suggesting that downburst
potential is low. Low-level lapse rates aren`t overly impressive
either (around 7.5 C/km), and the background low-level wind
field is on the weaker side. While a few isolated instances of
damaging winds may be possible, it doesn`t appear to be an
overly impressive setup for damaging winds. It`s also worth
noting that with saturated soils, it likely won`t take much to
bring down trees.

With supercells around, a few large hail reports can`t be ruled
out, but the environment doesn`t appear to be the most
favorable for large hail either. Profiles are saturated, a large
portion of the CAPE is located below the freezing level, and
mid-level lapse rates are poor, each of which work against
efficient hail production. The presence of supercells and the
strong updrafts they produce would be a favorable aspect for
hail production.

The tornado threat is a bit more interesting. Moist profiles
with low LCLs, a supercellular mode, and ample 0-3 km CAPE
(which will lead to efficient stretching and tilting of
environmental vorticity) are factors that would favor the
development of tornadoes. On the other hand, low level shear and
resultant SRH are both on the weaker side, which limits the
amount of environmental vorticity present to stretched into the
vertical. A few tornadoes appear possible, but at the same time
it also doesn`t look like an environment conducive for the
development of stronger tornadoes. A Tornado Watch is currently
in effect for western portions of the forecast area, and much of
the rest of the area remains in a Slight Risk for severe
thunderstorms from SPC.

Another potential threat worth mentioning is increasing synoptic
winds within northwesterly flow on the backside of the low
later tonight. Model soundings show around 40-50 knots of flow
developing just above the surface. While most of this wind
likely won`t make it down to the surface, gusts of 20-30 knots
may be possible later tonight, and some localized higher gusts
can`t be ruled out.

[yoda]

Tornado Watch until midnight for BR eastward to Delmarva 

[LeesburgWx]

The storm heading into southern Loudoun looks interesting. Let's see if it can grow

[yoda]

2 minutes ago, yoda said:

Tornado Watch until midnight for BR eastward to Delmarva 

URGENT - IMMEDIATE BROADCAST REQUESTED
   Tornado Watch Number 350
   NWS Storm Prediction Center Norman OK
   455 PM EDT Fri May 30 2025

   The NWS Storm Prediction Center has issued a

   * Tornado Watch for portions of 
     District Of Columbia
     Delaware
     Central and Eastern Maryland
     Central and Southern New Jersey
     Southeast Pennsylvania
     Northern and Eastern Virginia
     Coastal Waters

   * Effective this Friday afternoon from 455 PM until Midnight EDT.

   * Primary threats include...
     A couple tornadoes possible
     Scattered damaging wind gusts to 65 mph possible
     Isolated large hail events to 1.5 inches in diameter possible

   SUMMARY...Scattered thunderstorms are forecast to continue to
   develop late this afternoon and continue through the evening as
   storms progress from west to east across the Watch.  A few
   supercells are forecast with an attendant risk for a couple of
   tornadoes, damaging gusts, and isolated large hail.  Additional
   thunderstorm bands may also pose a risk for damaging gusts before
   all of this activity moves east of the coast.

   The tornado watch area is approximately along and 90 statute miles
   east and west of a line from 50 miles east of South Hill VA to 30
   miles northwest of Philadelphia PA. For a complete depiction of the
   watch see the associated watch outline update (WOUS64 KWNS WOU0).

[yoda]

40/20 tor probs 

[87storms]

5 hours ago, high risk said:

The more northern track of the surface low likely reduces the flash flood threat for most of us, but it definitely increases the severe threat.  Surface winds may end up too light, but if they’re not, some of the morning guidance does show enough turning in the low levels to generate favorable hodographs.  The 12z HREF reflects this with a notable increase in the probabilities for good UH values into the DC/Baltimore region, relative to earlier guidance, and I would not be surprised if the 1630 outlook brings the 5% TOR further north. 

Our region is an upper level low repellant, especially in the winter.  I'm just glad we'll get at least scraped by this system.

[yoda]

Maybe a lil something SW of EZF?

[Scraff]

Meh. I already see the back edge. Hi @Ji

[yoda]

TOR POSSIBLE tag on the severe warned EZF cell

And also on the severe warned line in the i81 corridor 

[LeesburgWx]

Just had a major downpour on the edge of the storm in Loudoun. Sun is back out now.

[SnowenOutThere]

Picture from the tail end of the louden/Fairfax storm. I’m not sure but sorta looks like a wall cloud?  

[yoda]

Looks like some hookage starting in western Spotsylvania county

[NorthArlington101]

8 minutes ago, SnowenOutThere said:

Picture from the tail end of the louden/Fairfax storm. I’m not sure but sorta looks like a wall cloud?  

Nice pic - but with pretty much nada rotation I’d lean shelf + SLC

[aldie 22]

39 minutes ago, LeesburgWx said:

The storm heading into southern Loudoun looks interesting. Let's see if it can grow

It was dropped. 66 in about 25 minutes 

[high risk]

I want to use the HRRR to figure out the evolution, but it has zero handle on the large batch of storms around Fredericksburg. 

[SnowenOutThere]

5 minutes ago, NorthArlington101 said:

Nice pic - but with pretty much nada rotation I’d lean shelf + SLC

There was horizontal rotation I’ll send a picture later 

[NorthArlington101]

Hope people get fun storms but not overly impressed with what I’m seeing thus far 

[WxUSAF]

WPC flash flooding meso out for metro areas and points north 

[yoda]

Tornado Warning near Mount Jackson 

[NorthArlington101]

1 minute ago, NorthArlington101 said:

Hope people get fun storms but not overly impressed with what I’m seeing thus far 

 

Just now, yoda said:

Tornado Warning near Mount Jackson 

Classic jinx - that’s some broad but strong rotation for these parts 

[George BM]

19 minutes ago, SnowenOutThere said:

Picture from the tail end of the louden/Fairfax storm. I’m not sure but sorta looks like a wall cloud?  

 Torrential rain I just received from this activity in Herndon.

[yoda]

2 minutes ago, yoda said:

Tornado Warning near Mount Jackson 

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Baltimore MD/Washington DC
550 PM EDT Fri May 30 2025

The National Weather Service in Sterling Virginia has issued a

* Tornado Warning for...
  Southern Shenandoah County in northwestern Virginia...
  Central Rockingham County in western Virginia...
  Southwestern Warren County in northwestern Virginia...
  Northern Page County in northwestern Virginia...
  West central Rappahannock County in northwestern Virginia...

* Until 630 PM EDT.

* At 549 PM EDT, a severe thunderstorm capable of producing a tornado
  was located near Mount Jackson, or 16 miles southwest of Woodstock,
  moving east at 40 mph.

  HAZARD...Tornado.

  SOURCE...Radar indicated rotation.

  IMPACT...For those in the direct path of a tornado touchdown,
           flying debris will be dangerous to those caught without
           shelter. Damage to roofs, siding, and windows may occur.
           Mobile homes may be damaged or destroyed. Tree damage is
           likely.

* This dangerous storm will be near...
  Luray and Mount Jackson around 555 PM EDT.
  Sperryville around 615 PM EDT.

Other locations impacted by this tornadic thunderstorm include
Kimball, Kings Crossing, Compton, Shenandoah Caverns, Leaksville,
Hamburg, Fourway, Quicksburg, Fairview, and Bentonville.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

&&

LAT...LON 3861 7874 3872 7878 3885 7829 3865 7820
TIME...MOT...LOC 2149Z 256DEG 36KT 3867 7867

TORNADO...RADAR INDICATED
MAX HAIL SIZE...<.75 IN

[yoda]

That line should be in DC metro around 8pm... Tornado warned portion is on path for the metro