2019 Mid-Atlantic Severe Wx - General Discussion

[mappy]

tis been a little busy

 

[nj2va]

4 hours ago, mappy said:

tis been a little busy

Really great job on this map...it's really fascinating to see the concentration in PA and OH.  And I like the overlay of the watches too.  Interesting that Anne Arundel/PG (ish) has been left off the watches this year.

[high risk]

6 minutes ago, nj2va said:

Really great job on this map...it's really fascinating to see the concentration in PA and OH.  And I like the overlay of the watches too.  Interesting that Anne Arundel/PG (ish) has been left off the watches this year.

     PG and AA were definitely in the blue box yesterday, so I'm not sure what the "blank space" over those counties represents.

 

[RandyHolt]

I wonder why the media cannot drill down and tell us right away town names when telling where a tornado hit. 

I have family and friends in Dayton (all ok), and hearing that a tornado hit Howard County is awful vague for the information era we live in currently.  We heard Howard county, I think I even heard Ellicott City, and then I heard Glenelg, and finally am now hearing it whacked Dayton pretty good.

[mappy]

1 hour ago, nj2va said:

Really great job on this map...it's really fascinating to see the concentration in PA and OH.  And I like the overlay of the watches too.  Interesting that Anne Arundel/PG (ish) has been left off the watches this year.

 

1 hour ago, high risk said:

     PG and AA were definitely in the blue box yesterday, so I'm not sure what the "blank space" over those counties represents.

 

its a weird thing the data does. has happened to me before, sometimes it drops DC, other times its the AA county area. if i had noticed (oops) i would have manually added a polygon to fill the hole. 

I was going to add severe thunderstorm warnings to it as well but man was that a busy map. so i just went with the watches. 

[The Dude]

23 hours ago, The Dude said:

It's tough to tell.  I doubt that guy knows exactly what happened because it the rain would have blocked his visibility.

All the tree damage I can see seems to be unidirectional (to the car's right), but the fairly narrow corridor of damage seems more suggestive of an embedded tornado rather than a microburst.  I'm sure NWS will send a survey team given the damage and the concurrent rotation visible on radar.

NWS says it was a tornado:

 

 

[yoda]

There was also an EF0 in Frederick County MD a bit earlier in the day near Ijamsville

https://mobile.twitter.com/NWS_BaltWash/status/1134612617140588545

[yoda]

SLGT risk for Sunday 

[high risk]

4 hours ago, yoda said:

SLGT risk for Sunday 

I was a bit surprised to see that this morning.     Instability now looks better than what was progged yesterday, but the shear looks really meh.     The soundings do have a fair amount of dry air beneath cloud base to promote strong downdrafts, and it looks like we’ll have a line of storms roll through at the favored time of day, so those are in our favor.   I’m “in” for a line of storms in the late afternoon (no earlier than that, please - hosting an outdoor kids’ birthday party), but I’m very “meh” for widespread severe as of now, although a few stronger gusts seem possible. 

[yoda]

Not in our CWA, but in Wakefield's CWA, Hertford County NC had baseball sized hail yesterday.  There are pictures on their Facebook of the hail

[yoda]

4 hours ago, high risk said:

I was a bit surprised to see that this morning.     Instability now looks better than what was progged yesterday, but the shear looks really meh.     The soundings do have a fair amount of dry air beneath cloud base to promote strong downdrafts, and it looks like we’ll have a line of storms roll through at the favored time of day, so those are in our favor.   I’m “in” for a line of storms in the late afternoon (no earlier than that, please - hosting an outdoor kids’ birthday party), but I’m very “meh” for widespread severe as of now, although a few stronger gusts seem possible. 

Hmmm... 1730 now mentions supercells 

 Day 2 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   1210 PM CDT Sat Jun 01 2019

   Valid 021200Z - 031200Z

   ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
   THE NORTHEAST/MID ATLANTIC REGION...AND ALSO ACROSS THE
   CENTRAL/SOUTHERN HIGH PLAINS...

   ...SUMMARY...
   Strong to severe storms capable of hail and strong wind gusts are
   possible across portions of the central and southern High Plains
   into Oklahoma on Sunday and Sunday night. Additional severe storms
   capable of primarily damaging winds are expected across portions of
   the Northeastern and Mid-Atlantic region Sunday afternoon and
   evening.

   ...Northeast/Mid Atlantic...
   A longwave upper trough will deepen over the Northeast and Mid
   Atlantic on Sunday, as individual vorticity maxima rotate through
   the mean trough position. A surface low should deepen and move
   northeastward across southern Quebec during the afternoon, as a
   trailing cold front sweeps through the Northeast/Mid Atlantic during
   the afternoon and evening. While cloud cover from weakening
   overnight convection may tend to limit insolation over portions of
   the area, sufficient heating and low-level moisture (dewpoints in
   the mid 50s to lower 60s F) should result in the development of
   moderate buoyancy in advance of the cold front by afternoon.
   Effective shear of 35-45 kt will support some organized structures;
   linear modes are most likely given that the primary focusing
   mechanism will be along the cold front, though any pre-frontal
   development will have some supercell potential. Damaging wind will
   likely be the primary threat, though any discrete storms will also
   have some potential for hail and perhaps a tornado. 

[high risk]

35 minutes ago, yoda said:

Hmmm... 1730 now mentions supercells 

 

 

     I would think that’s for the New England part of the slight risk.   The wind fields down here look pretty anemic:   15 kt or so at 850mb. 

[yoda]

1 hour ago, high risk said:

     I would think that’s for the New England part of the slight risk.   The wind fields down here look pretty anemic:   15 kt or so at 850mb. 

LWX seems gung ho for tomorrow afternoon in their afternoon AFD... and mentioned a tornado cannot be ruled out

Quote

SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
The aforementioned cold front will near to our west by Sunday
afternoon, bringing the threat for showers and thunderstorms to
the area once again. As this cold front approaches, a longwave
trough will be digging down across the Great Lakes region with
shortwave energy traversing out ahead of it and over the Mid
Atlantic. Along with frontal forcing, this will act to kick off
showers and thunderstorms around midday over the Potomac
Highlands, tracking eastward into the metros by late afternoon.
Temperatures Sunday afternoon will generally be in the 80s, as
dewpoints rise into the low to middle 60s along and east of the
Blue Ridge. As the activity pushes eastward across the CWA,
increasing mid level winds and decent instability with the
rising dewpoints and MUCAPE between 1500-2000 J/kg, strong to
severe storm potential will exist. Do expect the convective mode
to favor a linear orientation as storms will be focused along
the frontal boundary and 0-6km shear of 30-40kts remains fairly
unidirectional. The primary threat with this line of storms will
be damaging winds, but large hail and an isolated tornado cannot
be ruled out. Thunderstorm activity should be diminishing by
early evening as the leading line moves across the Bay. Some
showers will linger through the evening, but most will trend on
the drier side. Lows Sunday night drop into the 50s as cooler
and drier air filters in behind the frontal passage.

[high risk]

2 hours ago, yoda said:

LWX seems gung ho for tomorrow afternoon in their afternoon AFD... and mentioned a tornado cannot be ruled out

           I'm gung ho on storms, as this is a strong push of colder air (upper 60's on Monday!).   And it looks like there is just barely enough shear and instability (along with a relatively dry and well-mixed PBL, promoting strong downdrafts) to justify a SLGT risk.      But I just don't see the shear for TORs, especially in the low-levels.    I will say that the HRRR is a bit more aggressive than the NAM nest in terms of strengthening the wind fields later Sunday afternoon, so if storms are still around (i.e. a squall line hasn't swept through), I guess there could be some transient supercell structures, and since every storm in Howard County in the past few weeks spins something up, I won't potentially make an ass out of myself and say that there is no chance of a TOR.

[Kmlwx]

Good storms would be a nice way to end the weekend. I've been out on the bay all day so haven't had a chance to catch up until now. 

I'm in for meh storms - not in for widespread severe. I'll be back in Columbia by the time they are moving in...so just give me some good structure moving in from the north and west and I"ll be happy. 

[AmericanWxFreak]

SLGT remains. 2% tor for the norther tier counties and then 15/15 for the rest of us. 

Also a day 4 15% popped up for us. 

[87storms]

nam bulked up a bit since the last run.  looks like 2pm'ish we could have storms firing.  first piece of energy moving through around noon looks like it'll be mostly dry, though hopefully it doesn't bring too much cloud cover.  it's that mid afternoon stuff that could be worth monitoring.

[southmdwatcher]

https://www.spc.noaa.gov/products/watch/ww0315.html

URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 315
NWS Storm Prediction Center Norman OK
1255 PM EDT Sun Jun 2 2019

The NWS Storm Prediction Center has issued a

* Severe Thunderstorm Watch for portions of 
  District Of Columbia
  Western and Central Maryland
  Southeast Ohio
  Northern Virginia
  West Virginia
  Coastal Waters

* Effective this Sunday afternoon and evening from 1255 PM until
  800 PM EDT.

* Primary threats include...
  Scattered damaging wind gusts to 70 mph likely
  Scattered large hail and isolated very large hail events to 2
    inches in diameter possible

SUMMARY...Multiple rounds of thunderstorms are expected to develop
this afternoon across the watch area, spreading eastward through the
afternoon.  The strongest cells in this region will pose a risk of
damaging wind gusts and hail.

The severe thunderstorm watch area is approximately along and 70
statute miles north and south of a line from 35 miles west northwest
of Charleston WV to 30 miles north northeast of Patuxent River MD.

[southmdwatcher]

We have had decent mid level lapse rates(around or just above 7 C/km) for the morning and early afternoon, not enough shear today. 

[87storms]

pretty subpar storm situation going on so far.  the sky/air doesn't have that severe-y feel to it, but i'm hoping we can get some pop ups develop into the early evening.  gravy if we overperform, but not a great look to the radar atm.

[WeatherLovingDoc]

Hello. Any particular updates on severe weather for Baltimore to Washington DC corridor? Got family traveling today. Tyvm. WLD.

[87storms]

what does look healthy is wv imagery towards western md, so i'll stay in with the assumption that we have time to reshuffle before that pool of cooler air moves in.

[BlizzardNole]

My bar is 0.3 of rain.  Anything else, lightning etc., is gravy.

[87storms]

radar starting to juice up to the west as well and there's some lightning showing up on spark with those cells moving through frederick...

https://weather.cod.edu/satrad/nexrad/index.php?type=LWX-N0Q-1-24

[WeatherLovingDoc]

1 minute ago, 87storms said:

radar starting to juice up to the west as well and there's some lightning showing up on spark with those cells moving through frederick...

https://weather.cod.edu/satrad/nexrad/index.php?type=LWX-N0Q-1-24

Wow, Thank you very much for this detailed Sterling radar. Sure does look like Baltimore DC will be hit. 

[87storms]

1 minute ago, WeatherLovingDoc said:

Wow, Thank you very much for this detailed Sterling radar. Sure does look like Baltimore DC will be hit. 

np, cod is shoddy on mobile, but pretty good radar for desktop.  i'm eyeing severe (bc this is a severe thread), but with a front moving through i gotta think we're in good shape for storms.  just a matter of how strong/severe they get without having abundant sunshine.

[JakkelWx]

Active severe season on tap if the long range 3 month models are correct about a slightly BN summer. Hottest part will probably be later in the summer, starting July and it could get a little dry at times but overall, active severe season.

[JakkelWx]

Lots of turkey tower clouds OMBY

[poolz1]

Definitely looks like hail in that nasty cell near HGR. Maybe a little rotation starting? See if it tightens up some....

 

ETA...the PA severe magnet in full effect.

[87storms]

Per wv imagery, it’s just about gametime for the metros. Hoping to see some cells moving thru.