2022 Mid-Atlantic Severe Wx Thread (General Discussion Etc)

[Interstate]

No thank you for more severe storm.  I spend 2.5 hours cleaning up 2-20 foot branches that fell from my one of my locust trees.  I had to easy compared to some of my neighbors .

[yoda]

Haven't seen the phrase "violent thunderstorms" in an AFD from LWX in a while 

SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/...
The stalled front to our south will begin creeping north as a
warm front on Thursday. Early morning low clouds and drizzle may
also slide north across southern Maryland and Tidal Potomac and
farther into parts of the metro areas Thursday morning. As the
day progresses, we should less and less of low clouds and
drizzle as daytime heating should mix this out. The warm front
will continue to march north during the day Thursday. Winds will
become more southerly and increase both at the surface and a few
thousand feet above the ground Thursday afternoon. With this
increase in southerly winds comes an increase in low level
moisture; thus, PWATs could rise quickly from 1.25 to near 2
inches from early Thursday morning through late Thursday
evening. This moisture and increase in wind could set the stage
for an increased threat for violent thunderstorms and possible
flooding Friday into Friday night.

The instability will increase through the day on Thursday with
the added sunshine and warmth. Temperatures on Thursday will
trend upwards with highs expected to reach the middle to upper
70s. A leeside trough of low pressure nearly in sync with a warm
front pushing north of our region could be the zone in which
showers and a rumble of thunder form Thursday night and mainly
across the western zones.

Showers and thunderstorms, some on the strong to severe side,
could develop over the western zones Friday mid-morning and
carrying eastward Friday afternoon with addition development
into Friday evening. Heavy rainfall could lead to localized
flooding, while the more intense thunderstorms Friday afternoon
and evening could produce damaging winds and large hail. High
temperatures will reach the upper 70s to lower 80s on Friday
with dewpoint temperatures climbing into the middle to upper
60s.

[Stormfly]

Here we go again.  All I want to see is a firefly.  Or as many say in these parts, lightning bug!

I guess if we swing enough, we'll eventually hit something, right.  Hopefully it's that barn that's falling down, save me the trouble of using winches.

[Kmlwx]

It's not the sector that's centered over our area, but the SE sector from the 12z CIPS page at hr60 has June 1, 2012 as a pretty high analog. Doesn't show up at all on the sector centered over us. 

Taking a look at H5 it's not hugely different - but there are some key differences. It seems like the trough was more negatively tilting in 2012. We still have a couple days to adjust things - but I'm certainly not saying I expect that sort of result. But H5 is close enough to keep me interested. 

The 18z run of the NAM nest wasn't quite as impressive. 

[Eskimo Joe]

Best thing to do is walk away from this for 24 hours and remain emotionally disinvested. Check back with the 06z update on Friday and wait for the first few visible satellite images before committing.

[RDM]

7 hours ago, Interstate said:

No thank you for more severe storm.  I spend 2.5 hours cleaning up 2-20 foot branches that fell from my one of my locust trees.  I had to easy compared to some of my neighbors .

Have a bunch of locust trees on our property and can relate.  They are tough as nails, but brittle too and have a tendency to snap off.  Lost two trees to high winds during a "rotation event" that came through Oakton/Vienna about 8 years ago.  Snapped off both trunks about 10 feet above the ground.  Each trunk was about 20" in diameter.  Watched it happen from our front door about 50 yards away.  

On the good side, locust is one of the few woods that can be direct buried in the ground and is nearly impervious to insects.  It splits easy and burns great if you happen to have a wood burning fireplace.  

 

 

[yoda]

5/5/15 on day 2 morning OTLK from SPC 

[WinterWxLuvr]

10 hours ago, RDM said:

Have a bunch of locust trees on our property and can relate.  They are tough as nails, but brittle too and have a tendency to snap off.  Lost two trees to high winds during a "rotation event" that came through Oakton/Vienna about 8 years ago.  Snapped off both trunks about 10 feet above the ground.  Each trunk was about 20" in diameter.  Watched it happen from our front door about 50 yards away.  

On the good side, locust is one of the few woods that can be direct buried in the ground and is nearly impervious to insects.  It splits easy and burns great if you happen to have a wood burning fireplace.  

 

 

I’ve seen locust cause a chainsaw to throw sparks. And it wasn’t a rock 

[Stormfly]

42 minutes ago, WinterWxLuvr said:

I’ve seen locust cause a chainsaw to throw sparks. And it wasn’t a rock 

That can occur with any wood.  The sparks are coming from the guide bar.  Its OK to occasionally see (sparks) but frequent sparks mean there is an issue with not enough bar oil (oiler problem/clogged line/pump etc) or chain is too tight or damaged from derailing, etc.

[Kmlwx]

Some of the guidance has brought the activity earlier. A few CAMS even have the line entering around 17 or 18z. That's not going to work for severe weenies. 20z would be okay. 

[Kmlwx]

04/2011 is shown in the analogs as well and

That was our like 12 or 18 hours of tornado watches event. 

[Eskimo Joe]

31 minutes ago, Kmlwx said:

04/2011 is shown in the analogs as well and

That was our like 12 or 18 hours of tornado watches event. 

Two decent events in April 2011:

1. April 16, 2011: https://www.spc.noaa.gov/exper/archive/event.php?date=20110416
2. April 27, 2011: https://www.spc.noaa.gov/exper/archive/event.php?date=20110427

[mappy]

4/27-28 2011 was part of that super outbreak

[Eskimo Joe]

Tomorrow seems so dicey. Leaning towards a meh, but hopefully we can get a W.

[Kmlwx]

1 hour ago, Eskimo Joe said:

Tomorrow seems so dicey. Leaning towards a meh, but hopefully we can get a W.

When split between a meh and a yay, always go the EJ route of calling meh. I haven't had a chance to look at the 12z suite yet. 

[biodhokie]

Best is to expect nothing and to be surprised.

 

I'm expecting no clearing until about 1 PM and only 2-3 hours of good heating leaving us with gusty showers and a pity blue box or MD.

[yoda]

5% tor definitely was moved westward some on the 1730z SPC day 2 update... with DC metro now more in the middle 

[yoda]

...Carolinas into the Mid-Atlantic...
   Although mid-level lapse rates are expected to remain generally
   poor, rich low-level moisture characterized by mid 60s to low 70s
   surface dewpoints will likely be in place ahead of the cold front.
   Even modest diurnal heating should contribute to MLCAPE generally
   ranging from 500-1500 J/kg, with somewhat greater instability
   forecast from parts of MD/VA southward into the Carolinas. Enhanced
   low/mid-level south-southwesterly flow associated with the upper low
   is expected to be in place from the Carolinas northward over much of
   the eastern Mid-Atlantic states ahead of the front. Deep-layer shear
   of 35-50+ kt will easily support thunderstorm organization, with a
   mix of multicells and supercells possible.

   Thunderstorms that will probably be ongoing at the start of the
   period Friday morning should gradually increase in coverage and
   intensity along/ahead of the front from late Friday morning through
   the afternoon. With a large southerly component to the low/mid-level
   winds, convection should tend to grow upscale with time into small
   bowing clusters as individual updrafts interact with each other. It
   appears that scattered damaging winds will probably be the main
   threat as thunderstorms spread east-northeastward through the
   afternoon and early evening given the messy and mainly multicellular
   mode. But, enough low-level shear should also be present in
   association with a 30-40 kt southerly low-level jet to support a
   risk for a few tornadoes with any embedded supercells, particularly
   from central NC into VA/MD/DE, southeastern PA, and NJ Friday
   afternoon. Isolated hail may also occur with the strongest updrafts.
   The northern extent of the appreciable severe in NY and the
   Northeast will be heavily dependent on diurnal heating, the degree
   of which remains highly uncertain.

[yoda]

 

 

[high risk]

I'm backing off on my enthusiasm a bit due to an increasing number of model solutions that bring convection into our area as early as midday.    Probably need things to hold off a couple of hours to maximize heating in an environment that won't be excessively warm.

[Stormfly]

2 hours ago, biodhokie said:

Best is to expect nothing and to be surprised.

 

I'm expecting no clearing until about 1 PM and only 2-3 hours of good heating leaving us with gusty showers and a pity blue box or MD.

This.

This is Maryland, home of the megaBUST!

[yoda]

Good disco by LWX this afternoon re the severe and flooding threat

.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
Friday will be an active day -- but not without caveats -- as a
cold/occluded front and upper level low approach from the west.
Expect two main foci (but not necessarily limited to) for
shower/storm development: the first will be along the slowly
eastward advancing low level jet/lead wave, and the second
closer to the actual front and forcing from the main trough
axis. Low level clouds may have difficulty clearing ahead of
wave one, but models indicate the moisture rich airmass and
diurnal heating could result in moderate instability near and
east of the Blue Ridge Mountains by afternoon (this being a
potential question mark). Ongoing convection will likely see
some increase in intensity as it moves eastward. Even though
instability and lapse rates may be lacking, sufficient deep
layer shear ahead of the trough will be sufficient to result in
storm organization. Damaging winds will be the primary threat
due to the wind fields and potential for congealing into
clusters, but some hail is also possible. Low level shear
magnitude and low LCLs will also be sufficient for a tornado
threat, although the mesoscale environment could potentially be
messy. Forecast soundings are also indicative of a heavy rain
threat with saturated profiles, precipitable water greater than
1.5 inches, deep warm cloud layers, and low MBE velocities with
storm mergers and relatively slow eastward propagation possible.
Compounding the threat will be the potential for multiple waves
of storms. If the storm mode is too disorganized and
widespread, it`s possible heavy rain and flash flooding will be
the greater threat compared to severe storms.

It`s a bit uncertain how much instability the second round of
storms will have to work with, as it is not expected until late
afternoon in the mountains and evening (should it hold together)
east I-81. These storms have a conditional threat to be severe
if the atmosphere can recover as shear will still be in place.

[Kmlwx]

1 hour ago, high risk said:

I'm backing off on my enthusiasm a bit due to an increasing number of model solutions that bring convection into our area as early as midday.    Probably need things to hold off a couple of hours to maximize heating in an environment that won't be excessively warm.

Yeah - lots are now hitting the 16-18z time period. That's too early for our hopes. We need 19z or later...

[jewell2188]

1 hour ago, Kmlwx said:

Yeah - lots are now hitting the 16-18z time period. That's too early for our hopes. We need 19z or later...

Looking like flooding may be the biggest concern.

[Eskimo Joe]

22 minutes ago, jewell2188 said:

Looking like flooding may be the biggest concern.

Yea tomorrow has sporadic, but significant flash flooding all over it.

[batmanbrad]

WPC on board with flood potential tomorrow:

[Eskimo Joe]

Keep an eye on those cells in western NC. They've been having some tendency to spin. We might get a few early AM tors.

[yoda]

8 minutes ago, Eskimo Joe said:

Keep an eye on those cells in western NC. They've been having some tendency to spin. We might get a few early AM tors.

Are we talking about like in 3 to 6 hours or like after sunrise but before noon?

Anyway, MCD said they should weaken soon with loss of diurnal heating 

[Eskimo Joe]

2 minutes ago, yoda said:

Are we talking about like in 3 to 6 hours or like after sunrise but before noon?

Anyway, MCD said they should weaken soon with loss of diurnal heating 

After sunrise but before noon. Sometimes when we get these remnant showers/weak storms entering early on a day progged for severe weather they have just enough juice left to spark a rogue weak tornado or some other kind of pre-game action.

[yoda]

00z NAM has two rounds (both severe?)... one around 19z and another around 03z