Jump to content
  • Member Statistics

    17,272
    Total Members
    7,904
    Most Online
    Iceberg
    Newest Member
    Iceberg
    Joined

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


Kmlwx
 Share

Recommended Posts

Nice AFD from Mount Holly-

We continue to monitor the potential for severe weather this afternoon and evening. As is usually the case in northwest flow patterns, the severe weather potential today is highly uncertain. Most pressingly, it`s not clear what the forcing mechanism for convection would be. While the MCS to our west this morning probably won`t impact us with severe weather, it`s possible new cells could develop on its outflow. We will also have a cold front approaching by late today or tonight. This could also lead to convective development, but it`s not a very strong front and the column aloft also starts to become drier with time this evening. PoPs for the next 24 hours were derived from a broad-based blend of global and CAM guidance. They generally maximize at chance to likely values, and are highest from late afternoon through mid to late evening.

In a probabilistic sense, the most likely scenario appears to be that we get little if any in the way of severe weather today. It doesn`t seem likely that our moisture levels will recover in time to generate significant surface based instability, not to mention the cloud cover potentially keeping temperatures down. Lack of instability will be a big inhibitor considering the nebulous forcing. Most guidance does indicate a ribbon of some instability developing by late today over portions of Delmarva and east-central Pennsylvania, in the neighborhood of 500 to 1000 J/kg of SBCAPE. But with poor mid-level lapse rates and drier air advecting in aloft, it will be difficult to sustain robust updrafts in that sort of environment. The shear profiles are certainly interesting though, between the rather backed surface winds and strong mid-level flow. Should any sustained deep convective cells develop, which would be more likely if instability ends up greater than forecast, then there would be a threat for damaging winds and perhaps a tornado considering impressive SRH values by later today. Will definitely be a day where monitoring real time observations as well as trends in the CAMs is important.

  • Like 1
Link to comment
Share on other sites

15 minutes ago, AmericanWxFreak said:

Showing more discrete activity like before or is it getting us w the line/bow?

New development but potentially triggered in part by the existing line. Though models tend to do poorly with distinguishing new development from existing line - especially when the lines are blurred. 

Link to comment
Share on other sites

11 minutes ago, Kmlwx said:

Has the feeling like early activity *might* be an issue. Some stuff just W of Elkins now, and even a shower N of Culpeper. 

Only the HRRR has anything decent for today and it's mostly south of DC. Would argue we all temper our expectations greatly.

  • Like 1
Link to comment
Share on other sites

14 minutes ago, Eskimo Joe said:

Only the HRRR has anything decent for today and it's mostly south of DC. Would argue we all temper our expectations greatly.

Very messy radar now in WV. It's too early for this unfortunately if clouds or the activity itself moves into our area. Will be interested to see the 12z runs. 

Link to comment
Share on other sites

One encouraging sign is that my dewpoint has risen to the upper 60s (even pushing 70 at times). So the moisture has certainly advected back in. Some of the models that really didn't develop much instability seemed to have a dry pool of air in the area and especially in the eastern half of the area on earlier runs. However, I see dews are almost entirely into the mid to upper 60s across the area now...even low 70s in southern Maryland. 

  • Like 1
Link to comment
Share on other sites

29 minutes ago, Eskimo Joe said:

Only the HRRR has anything decent for today and it's mostly south of DC. Would argue we all temper our expectations greatly.

       While I agree that we should keep expectations in check, I'm sure if I totally agree with the details of this take.    The NAM Nest has certainly hated today for most of us in multiple runs, but last night's HiResWs ARW2 and FV3 were fine.   And while the HRRR doesn't like the tier of counties along the PA border, several runs have been plenty active for Montgomery/Howard/Baltimore.      Shear is fine today;  the question will how much of a westerly component is in the 850 flow and whether the early morning convection messes things up - both are certainly plausible fail scenarios.

  • Like 2
Link to comment
Share on other sites

Hopefully that WV activity can stay out there for the morning at the very least. I saw a few runs yesterday that brought activity in as early as 17z in spots. If we can prevent crapvection from forming closer in to the major metro - we might be okay. 

Link to comment
Share on other sites

5 minutes ago, Eskimo Joe said:

//time sensitive//

Take a look at the visible loop. Looks like a little swirl or vort max near Pittsburgh diving SE. Might be what's going to trigger our line this afternoon.

Certainly seems like all this messy convection about to come off the high terrain will be here very early. There's a lot of it too...not just a few cells. If that doesn't intensify it'll probably dampen our instability big time. 

Link to comment
Share on other sites

8 minutes ago, Kmlwx said:

Certainly seems like all this messy convection about to come off the high terrain will be here very early. There's a lot of it too...not just a few cells. If that doesn't intensify it'll probably dampen our instability big time. 

I have a feeling it's going to consolidate and intensify just as it hits Rt 15, and that will be the event for the day.

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...