2024 Severe Weather General Discussion

[WxUSAF]

29 minutes ago, ravensrule said:

My recommendation is to go with a non preferred company. Holy S**T no AC until July 11th would cause me to go postal. 

We went most of summer 2021 with no A/C due to a mess of a repair process. We got a single room air conditioner (not the window unit) for our bedroom to sleep with. It got the room nice and cool but was really loud. I like central A/C…

[WxUSAF]

18z GFS leaves us all happy 

[Kmlwx]

2 hours ago, ravensrule said:

My recommendation is to go with a non preferred company. Holy S**T no AC until July 11th would cause me to go postal. 

That's my vote too. Honestly this house's duct work is bad too...central air barely gets to the 2nd floor. Am kind of hoping to start fresh with a new system and better ducting 

[Eskimo Joe]

1 hour ago, WxUSAF said:

18z GFS leaves us all happy 

18z GFS appears to advect a piece of an EML directly across us underneath a belt of 75 kt winds. That, plus some better timing, would lead to a solid severe weather day in these parts. Still, we're over two days away and a lot can go wrong. Additionally, today's 12z and 18z operational GFS develop a surface low in the lee of the Appalachian Mts. This combined with the other features I just mention, could offset the normal mesoscale issues that plague our severe weather chances in this part. 

[high risk]

2 hours ago, Eskimo Joe said:

18z GFS appears to advect a piece of an EML directly across us underneath a belt of 75 kt winds. That, plus some better timing, would lead to a solid severe weather day in these parts. Still, we're over two days away and a lot can go wrong. Additionally, today's 12z and 18z operational GFS develop a surface low in the lee of the Appalachian Mts. This combined with the other features I just mention, could offset the normal mesoscale issues that plague our severe weather chances in this part. 

       One problem, though, is that the better flow aloft seems to be lagging behind and may arrive until after the front passes.    Still, I would take the GFS timing of the shortwave.   The 00Z NAM timing is slower, which is not what we want for this system.

[aldie 22]

Wow models really backed off for tomorrow at least around my area. If that whiffs uh oh

[dailylurker]

16 minutes ago, aldie 22 said:

Wow models really backed off for tomorrow at least around my area. If that whiffs uh oh

Looks like 2-3" of rain possible in the DC area. 

[yoda]

LWX AFD from this morning on Wednesdays severe threat

SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
A progressive array of shortwaves are forecast to track from
southern Alberta toward the north-central tier of the U.S.
today. These height falls will provide the next chance for any
organized convective activity. Based on the latest Storm
Prediction Center update, areas north of the Potomac Highlands
and central Virginia are in a Slight risk for severe
thunderstorms. The primary threats will be damaging wind gusts
and isolated large hailstones. Some of the guidance does show
some higher Supercell Composite indices along the Mason-Dixon
Line given the backed flow. With that in mind, a brief tornado
cannot be ruled out along this area of the Mid-Atlantic.

The thermodynamic environment should become increasingly
unstable as the boundary layer moistens through the day. This is
in the presence of afternoon temperatures which should rise into
the mid/upper 90s. The degree of low-level moistening is
somewhat uncertain, but the consensus does raise dew points into
the mid/upper 60s. This would support heat indices into the 100
to 104 degree range which does near Heat Advisory criteria. Will
continue to monitor the need for any such heat-related products.

Depending on how upstream activity survives the Appalachian
chain, some early morning showers could push into areas west of
I-81. However, the main show likely initiates along a lee-side
trough during the afternoon hours. This occurs in the presence
of rising buoyancy levels on the order of 2,000 to 2,500 J/kg.
High-resolution guidance favors propagating this activity
downstream toward the metro areas by the late afternoon to early
evening. Model soundings indicate there is plenty of vertical
shear to work with (35-40 knots), so expect storms to be
reasonably well organized. Depending on how everything else
plays out during peak heating, the cold front tracking through
late Wednesday could bring additional thunder chances if any
instability remains. Low temperatures on Wednesday night will
mainly be in the 60s, locally in the low 70s along and east of
I-95.

[Eskimo Joe]

8 hours ago, high risk said:

       One problem, though, is that the better flow aloft seems to be lagging behind and may arrive until after the front passes.    Still, I would take the GFS timing of the shortwave.   The 00Z NAM timing is slower, which is not what we want for this system.

Just like that everything falls apart. Lol.

[WxUSAF]

24 minutes ago, Eskimo Joe said:

Just like that everything falls apart. Lol.

6z mesos look pretty good? Globals are decent too? I’m mostly just looking from a rain perspective.

[Kmlwx]

It looks like the long range 6z GFS sets up a big heat dome to the west which puts us in an area that could be at risk for southward diving MCS-type things. Way too far out though for any clarity. At least something to watch if Wednesday fails. 

[yoda]

Hmmm... this is in all 3 of the HWOs this morning as of 730am

DAYS TWO THROUGH SEVEN...Wednesday through Monday

Hot and humid conditions are expected Wednesday afternoon, with
highs in the low to mid 90s and peak heat indices between 100 to
105.

Isolated to scattered severe thunderstorms capable of producing
damaging wind gusts and large hail are possible Wednesday
afternoon into Wednesday evening. There is the potential for
considerable wind damage, but confidence is low at this time.

Hot and humid conditions return over the weekend.

.SPOTTER INFORMATION STATEMENT...

Spotter activation may be needed for Wednesday afternoon and
evening.

[Kmlwx]

CSU-MLP for wind threat now has a small purple area showing up W of the area for tomorrow. 

[Kmlwx]

1 minute ago, Kmlwx said:

CSU-MLP for wind threat now has a small purple area showing up W of the area for tomorrow. 

[Eskimo Joe]

2 hours ago, yoda said:

Hmmm... this is in all 3 of the HWOs this morning as of 730am

DAYS TWO THROUGH SEVEN...Wednesday through Monday

Hot and humid conditions are expected Wednesday afternoon, with
highs in the low to mid 90s and peak heat indices between 100 to
105.

Isolated to scattered severe thunderstorms capable of producing
damaging wind gusts and large hail are possible Wednesday
afternoon into Wednesday evening. There is the potential for
considerable wind damage, but confidence is low at this time.

Hot and humid conditions return over the weekend.

.SPOTTER INFORMATION STATEMENT...

Spotter activation may be needed for Wednesday afternoon and
evening.

People probably worried about a derecho.

[NorthArlington101]

Tomorrow has the vibes of a good storm day. Stupid hot and a storm drought usually ends up being good for our odds.

[Eskimo Joe]

GFS appears to have lost the EML plume. 12z NAM is pretty meh for severe weather chances. Looks like a standard Slight Risk day might be shaping up.

[George BM]

2 hours ago, NorthArlington101 said:

Tomorrow has the vibes of a good storm day. Stupid hot and a storm drought usually ends up being good for our odds.

If nothing else, these dry conditions that we have should help further steepen LLLRs w/ solar heating (quicker heating of a dry surface... a + for wind potential).

[Kmlwx]

9 minutes ago, Eskimo Joe said:

GFS appears to have lost the EML plume. 12z NAM is pretty meh for severe weather chances. Looks like a standard Slight Risk day might be shaping up.

Yep. Other than the CSU MLP stuff it looks kind of meh. That NAM nest huge bow has been gone for several runs. I just hope it rains on my house to cool it 

[aldie 22]

6 hours ago, aldie 22 said:

Wow models really backed off for tomorrow at least around my area. If that whiffs uh oh

trend continues i believe NAM doesn't even have a raindrop for my house

[yoda]

New Day 2 at 1730z moves the SLGT risk south and west to now include all of the LWX CWA 

 

[yoda]

ENH upgrade was thought about FWIW 

@Kmlwx @Eskimo Joe

[yoda]

Day 2 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   1223 PM CDT Tue Jun 25 2024

   Valid 261200Z - 271200Z

   ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF
   THE OHIO VALLEY INTO THE MID-ATLANTIC AND NORTHEAST...

   ...SUMMARY...
   Scattered damaging winds are possible over parts of the Ohio Valley
   into the Mid-Atlantic and Northeast on Wednesday.

   ...OH Valley to Mid-Atlantic/Northeast...

   An upper trough will progress eastward on Wednesday from the
   Mid/Upper MS Valley to the Northeast/Mid-Atlantic. A seasonally
   moist airmass will be in place across much of the Midwest to the
   Mid-Atlantic where strong heating will support moderate to strong
   destabilization. Forcing for ascent associated with the
   eastward-advancing upper trough and one or more MCVs moving across
   the region will support scattered to numerous strong/severe
   thunderstorms through the period. 

   One cluster of strong/severe thunderstorms is expected to be focused
   from PA eastward into the NJ/southern NY vicinity ahead of a
   southward sagging cold front. Effective shear magnitudes around
   30-40 kt will support a few supercell and/or bowing structures.
   Steep low and midlevel lapse rates, with mixing to around 1 km,
   suggest damaging gusts and isolated large hail will be the main
   hazards with this activity. Another cluster of strong/severe storms
   is expected to develop over the higher terrain of eastern KY/WV and
   northern VA. Vertical shear will be weaker with southward extent,
   but deeper mixing with very steep lapse rates is noted in forecast
   soundings. Damaging gusts and isolated hail will also be possible
   with this activity. Some potential may exist for higher severe
   probabilities in subsequent outlooks for portions of the
   Mid-Atlantic/Northeast if an organized bowing structure can develop.
   However, confidence in this scenario is too low at this time for
   categorical upgrades.

   Additional storms are expected along the southward developing cold
   front during the late afternoon into evening closer to the OH River
   in southern IN and central KY. Weaker shear will limit longevity of
   more organized cells, but strong instability and steep lapse rates
   will still support localized strong gusts and marginal hail. 

 

[Eskimo Joe]

7 minutes ago, yoda said:

ENH upgrade was thought about FWIW 

@Kmlwx @Eskimo Joe

We'd need everything to come together perfectly tomorrow for that. I'm more worried now about debris clouds from the midwest just holding us in the mid 80s tomorrow and we don't event get any storms at all. 

[NorthArlington101]

Take with a massive grain of salt:

https://x.com/gkellerwx/status/1805632901024743795?s=46&t=YRAxGyE8QLsoshMtJniktg

[MN Transplant]

Per usual, the HRRR looks way too dry tomorrow afternoon, and the NAM is likely too humid.  I don’t know about severe, but one positive thing is that the front will have an east/west component to it, potentially allowing for multiple rounds of showers/storms.  

[WxUSAF]

12 minutes ago, NorthArlington101 said:

Take with a massive grain of salt:

https://x.com/gkellerwx/status/1805632901024743795?s=46&t=YRAxGyE8QLsoshMtJniktg

I don’t know anything about that, but FWIW, it nailed the tornado outbreak a few weeks ago.

[Eskimo Joe]

20 minutes ago, NorthArlington101 said:

Take with a massive grain of salt:

https://x.com/gkellerwx/status/1805632901024743795?s=46&t=YRAxGyE8QLsoshMtJniktg

That seems. . . .aggressive.

 

7 minutes ago, WxUSAF said:

I don’t know anything about that, but FWIW, it nailed the tornado outbreak a few weeks ago.

While it was accurate for the 5% TOR over DC, it missed the other 4 areas it forecast for tornadoes. As a result, it ended up with a 20% accuracy rate nationally.

[Eskimo Joe]

17 minutes ago, MN Transplant said:

Per usual, the HRRR looks way too dry tomorrow afternoon, and the NAM is likely too humid.  I don’t know about severe, but one positive thing is that the front will have an east/west component to it, potentially allowing for multiple rounds of showers/storms.  

Split the difference, put an ENH with a 30% wind and 5% TOR on the SWODY1 tomorrow and see how it plays out.

[Eskimo Joe]

That nado cast goes 15% over DC -> Baltimore tomorrow. . . .