2024 Severe Weather General Discussion

[Kmlwx]

We usually flag April as "it's still too early" - but it does come with the benefit of having some really potent systems sometimes before we head into the more summery "doldrum" patterns. It seems we always have a bit of a "butter zone" in spring and fall when CAPE is healthy enough for more than just pencil thin lines of gusty showers - but with higher shear than you'd see in July. 

[Eskimo Joe]

10 hours ago, Terpeast said:

Of course, I’ll be out of the country most of April. So it’ll be a fun month for everyone here. 

I'll be in Alaska most of May. 

[southmdwatcher]

Significant overperforming event across Indiana and Ohio this evening, storms heading our way for scraps tomorrow. 

[Kmlwx]

Every few runs of the GFS at least have had a storm system near the fantasy range/end of run that could be a severe producer for our area. Way too far out but has shown up a few times in varying forms. 

[Kmlwx]

The GFS has some decent supercell composite parameters to our west for next Tuesday afternoon - but the timing is bad for us and it fizzles east of the mountains. 

[George BM]

1 hour ago, Kmlwx said:

The GFS has some decent supercell composite parameters to our west for next Tuesday afternoon - but the timing is bad for us and it fizzles east of the mountains. 

SPC has that area in a 15% risk for that day. Slowly starting to warm up.

[Jebman]

On 3/6/2024 at 7:46 AM, Eskimo Joe said:

I'll be in Alaska most of May. 

Enjoy the snow! Take some jebwalks, shovel some, pile it up! 

[Kmlwx]

Day 5 15% - woo storms?

 

[Kmlwx]

The last few GFS runs appear to be having trouble pushing better dewpoints and such north of the Potomac. It's pretty darn early still - but it's something to track that's not only in the Plains. 

[George BM]

Woah. Kind of surprised to see us into the 15% risk for Tuesday and more surprised to see how far north the risk area extends (into southern PA) given how spring CAD setups usually play out. At a quick glance of the varsity models both the 0z CMC and 0z ECMWF had the warm front well to our south for Tuesday with only the GFS getting the warm front over us. I guess we'll see how this plays out. Now elevated convection/storms, on the other hand, I can see occurring to the north of the front. So, at the least, thunder/lightning is looking fairly likely for a good number of us on Tuesday. The SPC has better tools than we have at our disposal so it's definitely possible that they show something that the varsity models don't for Tuesday. As has been said, we'll see how this plays out and it's at least something severe-wise to track more locally.

 

[yoda]

I'd say that's some strong wording for Day 5 for our region 

Tuesday/Day 5...
   The upper-level system is forecast to move eastward into the Ozarks
   and mid Mississippi Valley on Tuesday. An associated cold front will
   likely move quickly eastward into the mid Mississippi Valley early
   in the day. Ahead of the front, a moist and unstable airmass is
   expected to be in place by midday, with scattered to numerous
   thunderstorms developing in the Ohio and Tennessee Valleys in the
   afternoon. The mid-level jet is forecast to move into the Ohio
   Valley by late afternoon, suggesting that a widespread severe threat
   will be possible. Strong deep-layer shear and lift associated with
   the jet would be favorable for supercells with a threat for wind
   damage, large hail and some tornadoes. The severe threat is forecast
   to extend southward into the Tennessee Valley, and eastward into the
   Mid-Atlantic, where scattered severe storms will be possible within
   a moist and unstable airmass.

[yoda]

Don't remember seeing HWOs listing severe for 5 days out before @Kmlwx @Eskimo Joe

Hazardous Weather Outlook
National Weather Service Baltimore MD/Washington DC
1055 AM EDT Fri Mar 29 2024

ANZ530>543-DCZ001-MDZ008-011-013-014-016>018-504-506-508-
VAZ053>057-527-301500-
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-Cecil-Southern Baltimore-
Prince Georges-Anne Arundel-Charles-St. Marys-Calvert-
Central and Southeast Montgomery-Central and Southeast Howard-
Southeast Harford-Fairfax-Arlington/Falls Church/Alexandria-
Stafford-Spotsylvania-King George-
Central and Southeast Prince William/Manassas/Manassas Park-
1055 AM EDT Fri Mar 29 2024

This Hazardous Weather Outlook is for the Maryland portion of the
Chesapeake Bay, Tidal Potomac River, and I-95 corridor through
central Maryland, northern Virginia, and District of Columbia.

.DAY ONE...Today and Tonight

A Gale Warning is in effect until 6 PM for the Chesapeake Bay and
adjoining estuaries north of Drum Point MD, and the tidal Potomac
River from Key Bridge to Cobb Island MD.

.DAYS TWO THROUGH SEVEN...Saturday through Thursday

There is a slight threat for severe weather on Tuesday into
Tuesday night. All severe weather hazards are potentially at play
should the threat materialize. Isolated instances of flooding are
also possible.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is possible on Tuesday.

 

[EastCoast NPZ]

In other words, windy and dry in the Shenandoah Valley with heavy rain and severe storms east of the BR.

[yoda]

4 hours ago, Kmlwx said:

The last few GFS runs appear to be having trouble pushing better dewpoints and such north of the Potomac. It's pretty darn early still - but it's something to track that's not only in the Plains. 

06z GFS does have steep mid-level lapse rates though... 7 C/KM to even some 8s across the region 

[Kmlwx]

I'm with @George BM for the most part. We've played this movie before...warm fronts this time of year struggle to get as far north as forecast unless there's some super anomalous push. Heck...even later into April they can struggle...and this would be ultra-early April. Will be interesting to see how this unfolds - but yeah that's a beefy/large 15% area. My guess is that NoVA might get into some surface based action - but I'm not sure I buy north of the Potomac and especially not closer to the M/D line. 

It's nice to have something semi interesting to track, at least. Maybe a sign we won't have a dead early season with weeks of boredom. 

[Eskimo Joe]

It's hard to be excited beyond a day or 30 hours out from the event. Unless you have some big Bermuda high set up with northwest flow, there are so many variables that can muck up severe weather this time of year.

[Kmlwx]

8 minutes ago, Eskimo Joe said:

It's hard to be excited beyond a day or 30 hours out from the event. Unless you have some big Bermuda high set up with northwest flow, there are so many variables that can muck up severe weather this time of year.

That being said - I would be happy even with a nice few claps of elevated thunder. The only way I'm okay with mosquito season is thunderstorms  - Not looking forward to sweating my butt off for months on end. 

[Eskimo Joe]

24 minutes ago, Kmlwx said:

That being said - I would be happy even with a nice few claps of elevated thunder. The only way I'm okay with mosquito season is thunderstorms  - Not looking forward to sweating my butt off for months on end. 

I could stand a quiet spring to get more mesonet stations in the ground.

[yoda]

 

 


  ZCZC SPCSWOD48 ALL
   ACUS48 KWNS 300840
   SPC AC 300840

   Day 4-8 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0340 AM CDT Sat Mar 30 2024

   Valid 021200Z - 071200Z

   ...DISCUSSION...
   ...Tuesday/Day 4 and Wednesday/Day 5...
   A positively tilted upper-level trough is forecast to move quickly
   northeastward into the mid Mississippi Valley on Tuesday, as an
   associated mid-level jet translates northeastward into the Ohio
   Valley. At the surface, a cold front will likely advance
   east-southeastward into the Ohio and Tennessee Valleys, with a moist
   and unstable airmass in place across the region. Scattered to
   numerous thunderstorms are expected to develop along and ahead of
   the front Tuesday afternoon. Strong deep-layer shear, associated
   with the mid-level jet, should be favorable for severe storms. Wind
   damage, hail and a few tornadoes are expected in the Ohio and
   Tennessee Valleys, with the severe potential extending eastward
   across the central Appalachians into the Mid-Atlantic.

   On Wednesday, the cold front is forecast to move to the Atlantic
   Seaboard. Ahead of the front, instability will increase during the
   morning. A severe threat could develop in some areas near the
   Atlantic coast early in the day, before the front moves offshore.
   Predictability is low concerning where the most favorable areas will
   be for strong thunderstorms.

[yoda]

 

[yoda]

Morning AFD from LWX on the threat 

.LONG TERM /TUESDAY THROUGH FRIDAY/...
An active weather pattern is likely to develop during the middle to
late part of next week, bringing possibly impactful weather to the
area. A strong Southern Stream Jet overspreads the area, with a
broad wave of mid-level energy phasing with a digging mid-level
trough from the Great Lakes. This is could bring strong to severe
storms and/or a flood threat to parts of the area Tuesday. The
ensuing mid-level cutoff low slowly moves east, as additional
embedded shortwaves rotate around the western side of the low. This
could bring mountain snow Wednesday night into Thursday, as well as
windy conditions to end the week.

The current temperature forecast for Tuesday is highly uncertain,
and will be dependent on precip, cloud cover, and the placement of a
warm front somewhere over or near the area. The area could be wedged
in the cooler airmass, keeping temps in the 50s, or warm advection
scours out the low-level inversion resulting in 60/70s for highs.
The first in a series of cold fronts crosses the area early
Wednesday morning, bringing gustier and near-normal temperatures
Wednesday through Friday.

Severe/Flood Threat (Tuesday/Wednesday): A warm front is forecast to
be draped across the CWA early in the week, likely producing a large
north to south temperature gradient. This is going to play a key
role in whether we see any strong/severe storms, and/or a potential
flood setup if other conditions line up. SPC has most of the area in
a Slight Risk (level 2 of 5) of severe weather for Tuesday. The
threat appears to be greatest in the Alleghenies and south of US-50
where there is the greatest chance of instability developing. Around
500-1000 J/kg of MLCAPE combined with a strong deep-layer shear (60-
75KT possible based on model soundings) could produce a favorable
environment for all modes of severe weather. A residual severe
threat is possible Wednesday in central VA. A flood threat could
develop along or north of the warm frontal boundary where training
storms result in heavier rain rates.

These aspects of the forecast remains highly uncertain, be sure to
stay tuned for additional updates in the coming days.

[RDM]

It's that time of year - April.  The super-outbreak of tornados on 3/4 April 1974 was one for the record books.  Recall it well.  

Xenia, Ohio was demolished - about 25 miles from our home just North of Dayton.  First responders provided mutual aid from throughout the Dayton area, and as far away as Columbus and Cincinnati.  The F-5 that plowed through the center of Xenia left a path that is still visible today.  

https://en.wikipedia.org/wiki/1974_Xenia_tornado  

Our dad and several firefighters from our local volunteer department in New Carlisle provided support for many days with our rescue truck - which was advanced for the era.  Families in town donated food which was ferried down to Xenia to feed our team, plus other first responders.  About a week after the tornado hit our dad drove us through the center of town - only getting by the National Guard checkpoints because of the big red light on top of his red and white Rambler.  The destruction was unworldly and unforgettable.  

There were over 30 F4/F5s in that outbreak.  Was beyond extreme in the intensity of the tornados and their duration on the ground.    

[Kmlwx]

75kts of shear might rip apart updrafts as well though. 

[yoda]

Day 2 MRGL up... 0/5/5

 

 

   ...Mid to Upper Ohio Valley/Central Appalachians/Mid-Atlantic...
   An anticyclonic mid-level flow pattern will be in place on Monday
   across the eastern U.S. At the surface, a quasi-stationary front is
   forecast to be located from southern Ohio east-southeastward into
   the Mid-Atlantic. This boundary will likely be a focus for
   convective development from the daytime hours into the overnight
   period. Although instability is forecast to remain weak near the
   boundary, strong deep-layer shear will be in place. This should
   support an isolated severe threat, potentially persisting for an
   extended period of time. Hail and isolated damaging gusts will
   likely be the primary concerns. The severe threat will likely be
   more isolated with eastward extent, mainly due to more limited
   low-level moisture content across the Mid-Atlantic.

[yoda]

SLGT risk for almost all LWX CWA into S PA on Tuesday and Tuesday night 

[Kmlwx]

I'm still not convinced DC/Baltimore will be in the game. VA seems like a better bet and even then who knows 

[Eskimo Joe]

2 hours ago, Kmlwx said:

I'm still not convinced DC/Baltimore will be in the game. VA seems like a better bet and even then who knows 

Agreed. This isn't our threat unless something changes big time.

[high risk]

Returned from a vacation and saw that we're going to be wedged on Tuesday with the front well south of here, so I was shocked to see that we're in a Day 3 SLGT.    All of the skepticism is of course warranted, as we don't do SVR here with elevated convection well at all.   That said, though, the lapse rates look shockingly impressive above the stable surface layer Tuesday evening or night, so maybe this is one of those super rare instances where we can get some decent hail even when temps at the ground are in the 40s.    Again, this type of setup is so difficult to make work in the Mid-Atlantic, but we don't often see 1500 of  elevated CAPE.

.

[yoda]

Afternoon day 2 update from SPC has MOD risk in Ohio, ENH near W MD and SLGT risk east of i81 corridor 

 

[yoda]