2019 Mid-Atlantic Severe Wx - General Discussion

[Eskimo Joe]

1 minute ago, high risk said:

12z nam nest in surprisingly perfect agreement. 

Link?

[yoda]

Haven't seen this issued one while...

Special Weather Statement
National Weather Service Baltimore MD/Washington DC
1040 AM EDT Sun May 26 2019

ANZ530>543-DCZ001-MDZ003>006-011-013-014-016>018-501>508-
VAZ025>031-036>040-050>057-501>508-WVZ050>053-055-501>506-262045-
Chesapeake Bay north of Pooles Island MD-
Chesapeake Bay from Pooles Island to Sandy Point MD-
Chesapeake Bay from Sandy Point to North Beach MD-
Chesapeake Bay from North Beach to Drum Point MD-
Chesapeake Bay from Drum Point MD to Smith Point VA-
Tidal Potomac from Key Bridge to Indian Head MD-
Tidal Potomac from Indian Head to Cobb Island MD-
Tidal Potomac from Cobb Island MD to Smith Point VA-
Patapsco River including Baltimore Harbor-
Chester River to Queenstown MD-Eastern Bay-
Choptank River to Cambridge MD and the Little Choptank River-
Patuxent River to Broomes Island MD-
Tangier Sound and the inland waters surrounding Bloodsworth
Island-District of Columbia-Washington-Frederick MD-Carroll-
Northern Baltimore-Southern Baltimore-Prince Georges-Anne Arundel-
Charles-St. Marys-Calvert-Extreme Western Allegany-
Central and Eastern Allegany-Northwest Montgomery-
Central and Southeast Montgomery-Northwest Howard-
Central and Southeast Howard-Northwest Harford-Southeast Harford-
Augusta-Rockingham-Shenandoah-Frederick VA-Page-Warren-Clarke-
Nelson-Albemarle-Greene-Madison-Rappahannock-Orange-Culpeper-
Prince William/Manassas/Manassas Park-Fairfax-
Arlington/Falls Church/Alexandria-Stafford-Spotsylvania-
King George-Northern Fauquier-Southern Fauquier-Western Highland-
Eastern Highland-Western Loudoun-Eastern Loudoun-
Northern Virginia Blue Ridge-Central Virginia Blue Ridge-
Hampshire-Morgan-Berkeley-Jefferson-Hardy-Western Grant-
Eastern Grant-Western Mineral-Eastern Mineral-Western Pendleton-
Eastern Pendleton-
Including the cities of Washington, Hagerstown, Frederick,
Ballenger Creek, Eldersburg, Westminster, Reisterstown,
Cockeysville, Baltimore, Bowie, Suitland-Silver Hill, Clinton,
College Park, Greenbelt, Laurel, Camp Springs, Glen Burnie,
Annapolis, Severn, South Gate, Severna Park, Arnold, Odenton,
St. Charles, Waldorf, Lexington Park, California,
Chesapeake Beach, Huntingtown, Dunkirk, North Beach, Lusby,
Prince Frederick, Frostburg, Cumberland, Germantown, Damascus,
Bethesda, Rockville, Gaithersburg, Silver Spring, Lisbon,
Columbia, Ellicott City, Jarrettsville, Aberdeen, Staunton,
Waynesboro, Stuarts Draft, Harrisonburg, Strasburg, Woodstock,
Mount Jackson, New Market, Winchester, Luray, Shenandoah,
Stanley, Front Royal, Berryville, Lovingston, Charlottesville,
Stanardsville, Madison, Orange, Gordonsville, Culpeper,
Dale City, Manassas, Woodbridge, Lake Ridge, Montclair, Reston,
Herndon, Annandale, Centreville, Chantilly, McLean, Franconia,
Arlington, Alexandria, Falls Church, Falmouth, Fredericksburg,
Dahlgren, Warrenton, Turnbull, Hightown, Monterey, Purcellville,
Leesburg, Ashburn, Sterling, Big Meadows, Wintergreen, Romney,
Paw Paw, Martinsburg, Charles Town, Shepherdstown, Moorefield,
Bayard, Mount Storm, Petersburg, Elk Garden, Antioch, Keyser,
New Creek, Ridgeville, Russelldale, Headsville, Fort Ashby,
Riverton, Brandywine, Franklin, Oak Flat, Ruddle, and Sugar Grove
1040 AM EDT Sun May 26 2019

...Severe Thunderstorms Likely This Afternoon and Evening...

Thunderstorms are likely across the entire area this afternoon and
evening. Some of the thunderstorms will be severe, with damaging
winds and large hail being the primary threats. Anyone who plans
on being outdoors during this time should pay close attention to
the latest forecasts.

Stay alert for warnings and be prepared to seek shelter quickly
should thunderstorms occur. If you see lightning or hear thunder,
you are close enough to be in harm`s way.

The threat for thunderstorms will most likely be in two rounds.
The first round through this afternoon may be more scattered in
nature, but again some of those storms will be severe with
damaging winds and large hail. More widespread showers and
thunderstorms are likely this evening into the overnight hours
ahead of a cold front, and some of these storms may be severe as
well.

[purduewx80]

14 minutes ago, yoda said:

Haven't seen this issued one while...

legit threat seeing what's out west and knowing that a lot of folks will be bbq'ing or at the beach today.

[yoda]

https://www.spc.noaa.gov/products/md/md0808.html

Mesoscale Discussion 0808
   NWS Storm Prediction Center Norman OK
   1014 AM CDT Sun May 26 2019

   Areas affected...Portions of the Mid-Atlantic

   Concerning...Severe potential...Watch possible 

   Valid 261514Z - 261745Z

   Probability of Watch Issuance...40 percent

   SUMMARY...Storms are expected to develop and move east across
   portions of the Mid-Atlantic over the next few hours. Severe storm
   coverage is uncertain, but a few storms could become capable of
   severe wind/hail. A severe thunderstorm watch issuance is possible.

   DISCUSSION...Multi-cellular convection is currently moving eastward
   and developing across western PA and eastern WV/western MD. Per
   water vapor imagery and mesoanalysis a vorticity max is associated
   with this convection and remnant MCV may embedded within the western
   PA convection. For now, these storms appear to be elevated, but as
   insolation continues storms are likely to become surface-based.
   Ahead of these storms, a warm, moist airmass is in place with
   temperatures increasing into the 80s, especially across Del-Mar-VA,
   and dewpoints from the mid 60s to low 70s. Per mesoanalysis and
   forecast soundings, MLCAPE is currently 500-1000 J/kg and likely to
   increase to 1000-1500 J/kg in the next couple of hours as surface
   heating continues. Effective bulk shear of 40-50 knots with mostly
   unidirectional/speed shear will be sufficient for isolated
   supercellular storms. Additionally, as the boundary layer warms,
   low-level lapse rates will steepen, increasing chances for damaging
   wind gusts.

   Severe storm coverage still remains uncertain. While a few severe
   storms are likely to develop, coverage may not meet watch criteria,
   and poor mid-level lapse rates may inhibit severe hail production.
   However, convective trends will be monitored for a possible watch
   issuance with damaging wind gusts as the primary threat.

   ..Nauslar/Thompson.. 05/26/2019

   ...Please see www.spc.noaa.gov for graphic product...

   ATTN...WFO...PHI...BGM...AKQ...CTP...LWX...

[fourseasons]

5 minutes ago, purduewx80 said:

legit threat seeing what's out west and knowing that a lot of folks will be bbq'ing or at the beach today.

Plus we've got Rolling Thunder going on right now in DC and environs, the concert at the Capitol tonight, pools open, people out on the water boating, etc.

[yoda]

https://mobile.twitter.com/NWS_BaltWash/status/1132666644189327362

[Eskimo Joe]

5 minutes ago, purduewx80 said:

legit threat seeing what's out west and knowing that a lot of folks will be bbq'ing or at the beach today.

Agreed.  Looks like a watch coming soon.

[yoda]

1 hour ago, Eskimo Joe said:

Link?

https://weather.cod.edu/forecast/

NAM NEST 

Composite radar reflectivity 

19z to 20z... then again around 02z

[yoda]

Wonder if we'll pop a 30 wind today

[poolz1]

Light to mod shower passing through right now. Going to be a hot soupy mess once the sun comes back out.

Perfect memorial day weekend weather imo. Steaks on the grill and kids running thru sprinklers in the yard.

Sent from my SAMSUNG-SM-G920A using Tapatalk

[yoda]

1630 SPC OTLK

...OH Valley to Mid-Atlantic through early tonight...
   A somewhat diffuse MCV and remnant convection are moving over
   western PA as of midday will continue eastward/east-southeastward
   over southern PA/northern VA/MD this afternoon.  Destabilization in
   advance of this subtle wave will support at least isolated storm
   development this afternoon, in an environment with straight
   hodographs (effective bulk shear 35-40 kt) and moderate buoyancy
   (MLCAPE near 1500 J/kg).  Damaging gusts and large hail will be the
   main threats.

   Farther west, a more pronounced shortwave trough near Saint Louis as
   of mid morning will progress eastward over the OH Valley through the
   afternoon and evening.  Moderate buoyancy will be present this
   afternoon in advance of the shortwave trough, along the synoptic
   front from southern IL across southern IN into OH, as well as a
   weakening outflow boundary from northern WV into northern KY. 
   Additional storm development is expected along these boundaries and
   in advance of the midlevel trough, with damaging gusts/large hail
   expected with storm clusters/embedded supercells.  The storm
   clusters could persist into late evening/early tonight while moving
   east of the Appalachians.

[JakkelWx]

DCAPE values around 1,000 near Balt and DC.

[yoda]

Another MD for the region

https://www.spc.noaa.gov/products/md/md0811.html

Mesoscale Discussion 0811
   NWS Storm Prediction Center Norman OK
   1245 PM CDT Sun May 26 2019

   Areas affected...Portions of the Mid-Atlantic

   Concerning...Severe potential...Watch possible 

   Valid 261745Z - 261945Z

   Probability of Watch Issuance...40 percent

   SUMMARY...Storms are beginning to redevelop in eastern West Virginia
   with damaging winds possible. Storm coverage will likely increase
   this afternoon, but severe coverage remains uncertain.

   DISCUSSION...Storms from this morning have continued over
   central/southern PA while the storms over Del-Mar-Va were unable to
   sustain themselves. New storms have begun to initiate in eastern WV
   with a building Cu field over northern VA. Severe storms remain
   likely over this area during the afternoon into the evening as
   thinking has not changed since MCD 808. Given the CAPE/shear,
   isolated supercells are likely with damaging wind gusts the main
   threat as low-level lapse rates steepen from daytime heating. Severe
   hail is also possible, but mid-level lapse rates are marginal. The
   lingering question remains severe storm coverage with uncertainty
   regarding how many supercells will develop or if any upscale
   organization can occur with the vorticity max/shortwave trough
   moving over the area.

   ..Nauslar/Thompson.. 05/26/2019

   ...Please see www.spc.noaa.gov for graphic product...

   ATTN...WFO...PHI...AKQ...CTP...LWX...RNK...PBZ...RLX...

[Tater Tot]

 

[Kmlwx]

Just fired up a spare smartphone running a hyperlapse video capture looking north (and a bit west) of Columbia. Hoping to catch any CU growth and subsequent storm formation. 

[JakkelWx]

Cloud debris clearing up west to east and the temperature has started rising again

[yoda]

Afternoon LWX AFD 

National Weather Service Baltimore MD/Washington DC
300 PM EDT Sun May 26 2019

.SYNOPSIS...
A weak cold front will settle southward across the area tonight,
stalling across the region on Monday before lifting northward
again Tuesday. Bermuda high pressure sets up toward the middle
portion of the week, resulting in hot and humid conditions over
much of the eastern United States.

&&

.NEAR TERM /THROUGH TONIGHT/...
This afternoon, a cold front extends across the Great Lakes.
Aloft, one shortwave/MCV is moving across southern Pennsylvania,
with another in the lower Ohio Valley. In between, broad lift in
the warm sector and weak vorticity advection in an unstable
atmosphere is resulting in scattered thunderstorm development.
Most of the lift with the lead MCV is to the north, and thus
activity through the remainder of the afternoon may be somewhat
scattered. MLCAPE is 1000-1500 J/kg with deep shear greater than
40 kt. Thus any storms that strengthen will have a severe
threat, with some supercells possible. Straight hodographs,
weak low level wind shear, and high LCLs will make the tornado
threat limited though. Modest mid level lapse rates and a
downsloping wind may inhibit storm intensity and the hail
threat, though obviously any supercells would counteract that.
So damaging winds due to steep low level lapse rates and decent
DCAPE will be the primary threat. There may be a bit of a lull
in activity between 5-8 PM.

Most high-res guidance indicates well-organized convection
upstream propagating into the area this evening. Given
instability and shear will still be present, a severe weather
risk will continue. While the storms should be a bit more
widespread, the severe weather coverage is a little more
uncertain since it will have to counteract a stabilizing
nocturnal boundary layer. This activity will likely exit to the
south/east by midnight - 2 AM, continuing to weaken as it does
so. The cold front will also push south, perhaps modulated by
the convection. There may be a lingering shower along the front,
but the latter half of the night should be more dry. Some patchy
fog could develop, though mostly cloudy skies will be a limiting
factor. Lows will be in the 60s.

[WxUSAF]

Got a good view of some big CU and CBs developing to the south and east from Howard High School in Ellicott City.

[jacindc]

Cloudburst just popped up right over SE DC/Nats Park.

.

[Eskimo Joe]

Sun came out and it's great.  90/68 in Reisterstown.

[JakkelWx]

Still no cumulus clouds here yet.. just clear skies with high clouds from a storm to my south.

 

eta 4:42 PM - gust front heading towards D.C may fire up new convection if it collides with that small thundershower west of Sterling

[Kmlwx]

Starting to think we'll have to wait for the stuff that the HRRR is insistent will come through around 1-2z

[Eskimo Joe]

Thinking we might bust outright today.  The leftover clouds might have knocked things down enough to keep activity confined to areas south of I-66.  I could go for another round of nighttime storms.

[yoda]

17 minutes ago, Eskimo Joe said:

Thinking we might bust outright today.  The leftover clouds might have knocked things down enough to keep activity confined to areas south of I-66.  I could go for another round of nighttime storms.

Well SPC issued a 3rd MD... 3rd times the charm? 

[yoda]

LWX reissued the SPS

Special Weather Statement
National Weather Service Baltimore MD/Washington DC
542 PM EDT Sun May 26 2019

ANZ530>543-DCZ001-MDZ003>006-011-013-014-016>018-501>508-
VAZ025>031-036>040-050>057-501>508-WVZ050>053-055-501>506-270000-
Chesapeake Bay north of Pooles Island MD-
Chesapeake Bay from Pooles Island to Sandy Point MD-
Chesapeake Bay from Sandy Point to North Beach MD-
Chesapeake Bay from North Beach to Drum Point MD-
Chesapeake Bay from Drum Point MD to Smith Point VA-
Tidal Potomac from Key Bridge to Indian Head MD-
Tidal Potomac from Indian Head to Cobb Island MD-
Tidal Potomac from Cobb Island MD to Smith Point VA-
Patapsco River including Baltimore Harbor-
Chester River to Queenstown MD-Eastern Bay-
Choptank River to Cambridge MD and the Little Choptank River-
Patuxent River to Broomes Island MD-
Tangier Sound and the inland waters surrounding Bloodsworth
Island-District of Columbia-Washington-Frederick MD-Carroll-
Northern Baltimore-Southern Baltimore-Prince Georges-Anne Arundel-
Charles-St. Marys-Calvert-Extreme Western Allegany-
Central and Eastern Allegany-Northwest Montgomery-
Central and Southeast Montgomery-Northwest Howard-
Central and Southeast Howard-Northwest Harford-Southeast Harford-
Augusta-Rockingham-Shenandoah-Frederick VA-Page-Warren-Clarke-
Nelson-Albemarle-Greene-Madison-Rappahannock-Orange-Culpeper-
Prince William/Manassas/Manassas Park-Fairfax-
Arlington/Falls Church/Alexandria-Stafford-Spotsylvania-
King George-Northern Fauquier-Southern Fauquier-Western Highland-
Eastern Highland-Western Loudoun-Eastern Loudoun-
Northern Virginia Blue Ridge-Central Virginia Blue Ridge-
Hampshire-Morgan-Berkeley-Jefferson-Hardy-Western Grant-
Eastern Grant-Western Mineral-Eastern Mineral-Western Pendleton-
Eastern Pendleton-
Including the cities of Washington, Hagerstown, Frederick,
Ballenger Creek, Eldersburg, Westminster, Reisterstown,
Cockeysville, Baltimore, Bowie, Suitland-Silver Hill, Clinton,
College Park, Greenbelt, Laurel, Camp Springs, Glen Burnie,
Annapolis, Severn, South Gate, Severna Park, Arnold, Odenton,
St. Charles, Waldorf, Lexington Park, California,
Chesapeake Beach, Huntingtown, Dunkirk, North Beach, Lusby,
Prince Frederick, Frostburg, Cumberland, Germantown, Damascus,
Bethesda, Rockville, Gaithersburg, Silver Spring, Lisbon,
Columbia, Ellicott City, Jarrettsville, Aberdeen, Staunton,
Waynesboro, Stuarts Draft, Harrisonburg, Strasburg, Woodstock,
Mount Jackson, New Market, Winchester, Luray, Shenandoah,
Stanley, Front Royal, Berryville, Lovingston, Charlottesville,
Stanardsville, Madison, Orange, Gordonsville, Culpeper,
Dale City, Manassas, Woodbridge, Lake Ridge, Montclair, Reston,
Herndon, Annandale, Centreville, Chantilly, McLean, Franconia,
Arlington, Alexandria, Falls Church, Falmouth, Fredericksburg,
Dahlgren, Warrenton, Turnbull, Hightown, Monterey, Purcellville,
Leesburg, Ashburn, Sterling, Big Meadows, Wintergreen, Romney,
Paw Paw, Martinsburg, Charles Town, Shepherdstown, Moorefield,
Bayard, Mount Storm, Petersburg, Elk Garden, Antioch, Keyser,
New Creek, Ridgeville, Russelldale, Headsville, Fort Ashby,
Riverton, Brandywine, Franklin, Oak Flat, Ruddle, and Sugar Grove
542 PM EDT Sun May 26 2019

...Severe Thunderstorms Likely This Evening...

Widely scattered thunderstorms will be popping up anywhere in
Maryland between the Chesapeake Bay and the Appalachians,
northern and central Virginia, eastern West Virginia, and the
District of Columbia late this afternoon. Activity will become
numerous this evening. Any thunderstorm today will be capable of
becoming severe, with damaging winds and large hail being the
primary threats.

Anyone who plans on being outdoors should pay close attention to
the latest forecasts. Stay alert for warnings and be prepared to
seek shelter quickly should thunderstorms occur. If you see
lightning or hear thunder, you are close enough to be in harm`s
way.

[jewell2188]

26 minutes ago, yoda said:

LWX reissued the SPS

Special Weather Statement
National Weather Service Baltimore MD/Washington DC
542 PM EDT Sun May 26 2019

ANZ530>543-DCZ001-MDZ003>006-011-013-014-016>018-501>508-
VAZ025>031-036>040-050>057-501>508-WVZ050>053-055-501>506-270000-
Chesapeake Bay north of Pooles Island MD-
Chesapeake Bay from Pooles Island to Sandy Point MD-
Chesapeake Bay from Sandy Point to North Beach MD-
Chesapeake Bay from North Beach to Drum Point MD-
Chesapeake Bay from Drum Point MD to Smith Point VA-
Tidal Potomac from Key Bridge to Indian Head MD-
Tidal Potomac from Indian Head to Cobb Island MD-
Tidal Potomac from Cobb Island MD to Smith Point VA-
Patapsco River including Baltimore Harbor-
Chester River to Queenstown MD-Eastern Bay-
Choptank River to Cambridge MD and the Little Choptank River-
Patuxent River to Broomes Island MD-
Tangier Sound and the inland waters surrounding Bloodsworth
Island-District of Columbia-Washington-Frederick MD-Carroll-
Northern Baltimore-Southern Baltimore-Prince Georges-Anne Arundel-
Charles-St. Marys-Calvert-Extreme Western Allegany-
Central and Eastern Allegany-Northwest Montgomery-
Central and Southeast Montgomery-Northwest Howard-
Central and Southeast Howard-Northwest Harford-Southeast Harford-
Augusta-Rockingham-Shenandoah-Frederick VA-Page-Warren-Clarke-
Nelson-Albemarle-Greene-Madison-Rappahannock-Orange-Culpeper-
Prince William/Manassas/Manassas Park-Fairfax-
Arlington/Falls Church/Alexandria-Stafford-Spotsylvania-
King George-Northern Fauquier-Southern Fauquier-Western Highland-
Eastern Highland-Western Loudoun-Eastern Loudoun-
Northern Virginia Blue Ridge-Central Virginia Blue Ridge-
Hampshire-Morgan-Berkeley-Jefferson-Hardy-Western Grant-
Eastern Grant-Western Mineral-Eastern Mineral-Western Pendleton-
Eastern Pendleton-
Including the cities of Washington, Hagerstown, Frederick,
Ballenger Creek, Eldersburg, Westminster, Reisterstown,
Cockeysville, Baltimore, Bowie, Suitland-Silver Hill, Clinton,
College Park, Greenbelt, Laurel, Camp Springs, Glen Burnie,
Annapolis, Severn, South Gate, Severna Park, Arnold, Odenton,
St. Charles, Waldorf, Lexington Park, California,
Chesapeake Beach, Huntingtown, Dunkirk, North Beach, Lusby,
Prince Frederick, Frostburg, Cumberland, Germantown, Damascus,
Bethesda, Rockville, Gaithersburg, Silver Spring, Lisbon,
Columbia, Ellicott City, Jarrettsville, Aberdeen, Staunton,
Waynesboro, Stuarts Draft, Harrisonburg, Strasburg, Woodstock,
Mount Jackson, New Market, Winchester, Luray, Shenandoah,
Stanley, Front Royal, Berryville, Lovingston, Charlottesville,
Stanardsville, Madison, Orange, Gordonsville, Culpeper,
Dale City, Manassas, Woodbridge, Lake Ridge, Montclair, Reston,
Herndon, Annandale, Centreville, Chantilly, McLean, Franconia,
Arlington, Alexandria, Falls Church, Falmouth, Fredericksburg,
Dahlgren, Warrenton, Turnbull, Hightown, Monterey, Purcellville,
Leesburg, Ashburn, Sterling, Big Meadows, Wintergreen, Romney,
Paw Paw, Martinsburg, Charles Town, Shepherdstown, Moorefield,
Bayard, Mount Storm, Petersburg, Elk Garden, Antioch, Keyser,
New Creek, Ridgeville, Russelldale, Headsville, Fort Ashby,
Riverton, Brandywine, Franklin, Oak Flat, Ruddle, and Sugar Grove
542 PM EDT Sun May 26 2019

...Severe Thunderstorms Likely This Evening...

Widely scattered thunderstorms will be popping up anywhere in
Maryland between the Chesapeake Bay and the Appalachians,
northern and central Virginia, eastern West Virginia, and the
District of Columbia late this afternoon. Activity will become
numerous this evening. Any thunderstorm today will be capable of
becoming severe, with damaging winds and large hail being the
primary threats.

Anyone who plans on being outdoors should pay close attention to
the latest forecasts. Stay alert for warnings and be prepared to
seek shelter quickly should thunderstorms occur. If you see
lightning or hear thunder, you are close enough to be in harm`s
way.

It’s almost like the wording they used that they have no clue lol. Seem like a typical summer day with pop up storms nothing out of the unusual.

[Stormfly]

Just got alerted for a lightning strike 8 miles south of me.  Checked and yep, stuff popping up.  Popcorn inbound.

[Sparky]

Don't look now but there are some nice towers showing in the sky to my northwest with nothing yet showing on radar.

[Kmlwx]

Yeah it looks like the evening stuff is getting going. Let's see how it does with lowering instability/loss of daytime heating. 

[Eskimo Joe]

10 minutes ago, losetoa6 said:

Looks like a outflow boundary lifting north of DC in Montgomery county area ...maybe a focus soon there .

My dewpoint has spiked from 70 to currently 75

Yea just saw that.  Boundaries like that can compensate for the loss of daytime heating.