Jump to content
  • Member Statistics

    17,606
    Total Members
    7,904
    Most Online
    ArlyDude
    Newest Member
    ArlyDude
    Joined

2013 Mt. Holly CWA Convection Thread


SouthernNJ

Recommended Posts

Quite an impressive line from State College all the way down into Virginia, especially considering the 6z outlook from SPC was only a 5%.

 

Let's see if it holds together.

 

The 16z (latest) HRRR seems to have a good handle it on as of now (19z):

 

1ref_t3sfc_f03.png

 

Keeps it as a broken line (although weaker) through 0z and then collapses it just as it gets to Philly.

 

1ref_t3sfc_f08.png

 

 

The 12z SPC WRF is similar.  Gives the Berks County area a good hit around 23z and then breaks it apart to noting but a few showers by 1z.

Link to comment
Share on other sites

  • Replies 1k
  • Created
  • Last Reply

Impressive bow west of State College at the north end of that line.

 

Pretty good area of 50-55 kt on lowest BV tilt from western Juniata into Snyder and eastern Centre.  A few pixels above 60 kts at only ~1500 ft AGL in Centre.  Probably should be warning on higher than 60 mph out there.

Link to comment
Share on other sites

the river will eat it up, don't worry 

 

 

I want to do some research on this.  I'm incredibly skeptical that the river's microclimate can actually have that much of an effect.

 

Does Mt. Holly want a Hollings next year?

 

I've noticed the same phenomena occurring with storms crossing the susquehanna from york to lancaster.

Link to comment
Share on other sites

I've noticed the same phenomena occurring with storms crossing the susquehanna from york to lancaster.

 

I'm just not buying it.  Look at the radar the last few frames.  The entire line went outflow-dominant, from Hackettstown to Salem.  That can't just be the river.

Link to comment
Share on other sites

I'm just not buying it.  Look at the radar the last few frames.  The entire line went outflow-dominant, from Hackettstown to Salem.  That can't just be the river.

 

Oh, I'm not saying it applies to every situation, but I've seen it happen here on more than one occasion, usually the isolated storms that pop up in Franklin/Adams counties and travel east.

Link to comment
Share on other sites

I'm just not buying it.  Look at the radar the last few frames.  The entire line went outflow-dominant, from Hackettstown to Salem.  That can't just be the river.

It was something Lee had mentioned a long time ago and so now it's kind of a forum joking answer to every screw-job.

And wow... we did get screwed.

Link to comment
Share on other sites

Could also be something to do with downslope... Just a wild guess

 

That's what I'm wondering about the Tamaqua area. It seems that more often than not, an approaching line from the west falls apart as it nears/crosses I-81, then reforms to the east along and near I-476.

Link to comment
Share on other sites

That's what I'm wondering about the Tamaqua area. It seems that more often than not, an approaching line from the west falls apart as it nears/crosses I-81, then reforms to the east along and near I-476.

 

How does it line up with the fall line mentioned for winter storms?

Link to comment
Share on other sites

The fall line is near I-95. But the first ridge of the ridge and valley region could probably have as much as if not more of an effect

 

Scudders falls is an example where the fall line intersects the delaware?

Link to comment
Share on other sites

Scudders falls is an example where the fall line intersects the delaware?

 

Read more on Wiki, didn't realize the fall line was so far east. Coming down from Rt 80, down Rt 33, east on 78, south on 31,you  feel like you're pretty much 'falling' in elevation. I guessed wrong that the fall line was everything coming east of the appalachian ridge 

Link to comment
Share on other sites

Interesting discussion regarding why perhaps the Delaware River kills convection many times. I am not aware of any focused studies on this, but figured I would add my two cents.

 

I think there are several things that come into play here. The timing of the convection can have an impact, as typically it does not get to the river until later in the day. By this time, there can be some influence from a Delaware Bay breeze that gets up to the Wilmington area and even sometimes a river breeze affects Philadelphia. In addition given the right setup, a robust sea breeze can charge well inland and get to near the river before the convection arrives. This allows a more stable low-level environment to get ingested into the convection. Also, terrain circulations I think helps to keep convection going longer especially outside of larger scale forcing. Therefore as the convection gets to the river, the elevation lowers and any terrain induced circulations are pretty much gone. Also, the forcing at least at times hangs back to the west, therefore the convection ends up outrunning this as it heads east and then basically either weakens from less forcing and/or it becomes outflow dominant as it nears or crosses the river. It seems if convection organizes fairly far to our west (has a long way to travel) and large scale forcing is lacking, the convection tends to weaken (becomes outflow dominant) as it crosses our area. Also, sometimes the boundary layer is cooling with an eastward extent by the time the convection arrives.

Link to comment
Share on other sites

Interesting discussion regarding why perhaps the Delaware River kills convection many times. I am not aware of any focused studies on this, but figured I would add my two cents.

 

I think there are several things that come into play here. The timing of the convection can have an impact, as typically it does not get to the river until later in the day. By this time, there can be some influence from a Delaware Bay breeze that gets up to the Wilmington area and even sometimes a river breeze affects Philadelphia. In addition given the right setup, a robust sea breeze can charge well inland and get to near the river before the convection arrives. This allows a more stable low-level environment to get ingested into the convection. Also, terrain circulations I think helps to keep convection going longer especially outside of larger scale forcing. Therefore as the convection gets to the river, the elevation lowers and any terrain induced circulations are pretty much gone. Also, the forcing at least at times hangs back to the west, therefore the convection ends up outrunning this as it heads east and then basically either weakens from less forcing and/or it becomes outflow dominant as it nears or crosses the river. It seems if convection organizes fairly far to our west (has a long way to travel) and large scale forcing is lacking, the convection tends to weaken (becomes outflow dominant) as it crosses our area. Also, sometimes the boundary layer is cooling with an eastward extent by the time the convection arrives.

good analysis Mike. Yesterday, the end game was written for some parts of the area once it formed an OFB ahead of it.

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

  • Recently Browsing   0 members

    • No registered users viewing this page.

×
×
  • Create New...