Jump to content
  • Member Statistics

    17,588
    Total Members
    7,904
    Most Online
    LopezElliana
    Newest Member
    LopezElliana
    Joined

JULY 2012 Severe Weather /Convection Discussion


NEG NAO

Recommended Posts

  • Replies 1.9k
  • Created
  • Last Reply
Looks like the NYC metro will miss out on the storms today the ones in the mid Hudson valley seem to be weakening as they move se hopefully something changes later but doesn't look good as of now!!!!

Great post, being there's a severe warned cell heading right for NYC.

Link to comment
Share on other sites

there is? looks like its all falling apart now with loss of heating

Vil still a very impressive 80 in main updraft. That is a very healthy number. Storm over past hour has redeveloped on west end thus causing trajectory a bit further south then previously. The dying older updrafts have given it a more sloppy presentation on base reflectivity. Recent report out of Pike county PA of multiple trees and wires down. Still pretty healthy.

Link to comment
Share on other sites

Great post, being there's a severe warned cell heading right for NYC.

That storm is highly unlikely make it to NYC as a severe storm or even a strong one, you can see on radar that the anvil is blowing due east/southeast and it's raining over Northeast NJ and towards NYC.

The storm should turn more south/southeast with some redevelopment on the southwest side towards the axis of greater ml/mucape that remains at this hour.

Link to comment
Share on other sites

That storm is highly unlikely make it to NYC as a severe storm or even a strong one, you can see on radar that the anvil is blowing due east/southeast and it's raining over Northeast NJ and towards NYC.

The storm should turn more south/southeast with some redevelopment on the southwest side towards the axis of greater ml/mucape that remains at this hour.

And that's exactly what is happening...excellent post John

Link to comment
Share on other sites

The end of the week also offers some potential for organized significant severe weather..but things are currently very muddled and somewhat disorganized on the models. It will be interesting to see if things come into better focus over the next few days.

It will be interesting to see how things play out as we get closer. The developing block over Greenland should

force the surface low to track close enough to us for good shear and helicity values.

Link to comment
Share on other sites

Friday could be a very active day IMO across the Northeast, particularly New England. Whenever you see a closed sfc low, probably sub 1008mb, potentially down as low as 1000mb, you've got to watch out. Closed low up through 850 and 700mb with plenty of WAA, higher dew point advection northeastward into the area. Should be plenty of wind shear associated w/ this system, as well as surface instability via 90 degree temps and 65-70F tds. As we often see around here, the high CAPE/low shear enviros tend to produce scattered intense convection, but mod CAPE/high shear usually more efficient in producing widespread, organized, convection beyond the typical pulsers like we saw today. Helicity values may be elevated closer to the sfc low; I'd think the tornado risk would be increased for portions of NY State, nern PA, into interior New England most likely. The track of the low is obviously important, but there should be enough thermodynamic and kinematic support at our latitude for fairly organized severe. I don't like saying much this far in advance, but the stronger sfc low sends out a red flag for me. These synoptic set-ups usually don't disappoint for the majority. If I remember correctly, our most active convective day so far this summer involved a closed low. I like to watch out for upper lows, sub 1006-08mb sfc lows, and MCS differential advection as our best T-storm producers during the JJA period.

Link to comment
Share on other sites

Friday could be a very active day IMO across the Northeast, particularly New England. Whenever you see a closed sfc low, probably sub 1008mb, potentially down as low as 1000mb, you've got to watch out. Closed low up through 850 and 700mb with plenty of WAA, higher dew point advection northeastward into the area. Should be plenty of wind shear associated w/ this system, as well as surface instability via 90 degree temps and 65-70F tds. As we often see around here, the high CAPE/low shear enviros tend to produce scattered intense convection, but mod CAPE/high shear usually more efficient in producing widespread, organized, convection beyond the typical pulsers like we saw today. Helicity values may be elevated closer to the sfc low; I'd think the tornado risk would be increased for portions of NY State, nern PA, into interior New England most likely. The track of the low is obviously important, but there should be enough thermodynamic and kinematic support at our latitude for fairly organized severe. I don't like saying much this far in advance, but the stronger sfc low sends out a red flag for me. These synoptic set-ups usually don't disappoint for the majority. If I remember correctly, our most active convective day so far this summer involved a closed low. I like to watch out for upper lows, sub 1006-08mb sfc lows, and MCS differential advection as our best T-storm producers during the JJA period.

Meant to say Thursday in this post. One potentially major caveat that I see is timing. Would lik to see the FROPA speed up a bit. High tide for convection is usually 18z-00z, maybe as late as 04z, which would place PA/NY at much better risk than us.

Link to comment
Share on other sites

I think the low pressure on the GFS may convective feedback crap...but I also agree that the general pattern is supportive of organized and/or widespread convection from the Great Lakes to the Northeast the end of this week. The NAM, interestingly enough, also has the vort at 66 hrs that produces what seems to be an MCS over the Northeast along the WF

http://www.meteo.psu.edu/~gadomski/WRF_18z/f66.gif

But I would be interested in the low pressure area over the TN Valley tracking northeast into New England and any potential low level shear and juxtaposition of instability we can get near the warm sector which will creep into our area.

Link to comment
Share on other sites

Friday could be a very active day IMO across the Northeast, particularly New England. Whenever you see a closed sfc low, probably sub 1008mb, potentially down as low as 1000mb, you've got to watch out. Closed low up through 850 and 700mb with plenty of WAA, higher dew point advection northeastward into the area. Should be plenty of wind shear associated w/ this system, as well as surface instability via 90 degree temps and 65-70F tds. As we often see around here, the high CAPE/low shear enviros tend to produce scattered intense convection, but mod CAPE/high shear usually more efficient in producing widespread, organized, convection beyond the typical pulsers like we saw today. Helicity values may be elevated closer to the sfc low; I'd think the tornado risk would be increased for portions of NY State, nern PA, into interior New England most likely. The track of the low is obviously important, but there should be enough thermodynamic and kinematic support at our latitude for fairly organized severe. I don't like saying much this far in advance, but the stronger sfc low sends out a red flag for me. These synoptic set-ups usually don't disappoint for the majority. If I remember correctly, our most active convective day so far this summer involved a closed low. I like to watch out for upper lows, sub 1006-08mb sfc lows, and MCS differential advection as our best T-storm producers during the JJA period.

I actually think Thursday looks to be the more active day, the 18z NAM has the 1003mb low pressure system over PA/NY and the 18z GFS has a 993mb low over NY, GFS seems more impressive, this storm system on Thursday/Friday time period looks far more dangerous then today's storm system, unlike today in most the risk area, the environment will not be capped, i agree a fairly significant tornado event could be possible

Link to comment
Share on other sites

The SPC SREF has some very impressive early numbers for Thursday evening along the front...with 0-6km bulk shear and effective shear in excess of 40 kts...0-3km helicity over 250 m2/s2 ..and the instability axis shooting north by 2100z. Here are the 0-3km helicity parameters at that hour

http://www.spc.noaa...._MXMN__f078.gif

The juxtaposition of the aforementioned parameters is even triggering a sigtor over parts of the Northeast

http://www.spc.noaa....igtor__f078.gif

Link to comment
Share on other sites

I think the low pressure on the GFS may convective feedback crap...but I also agree that the general pattern is supportive of organized and/or widespread convection from the Great Lakes to the Northeast the end of this week. The NAM, interestingly enough, also has the vort at 66 hrs that produces what seems to be an MCS over the Northeast along the WF

http://www.meteo.psu...WRF_18z/f66.gif

But I would be interested in the low pressure area over the TN Valley tracking northeast into New England and any potential low level shear and juxtaposition of instability we can get near the warm sector which will creep into our area.

Yeah it should be an interesting late week. Maybe I've been spoiled with T-storms this summer, but the past couple weeks have been getting boring weather wise.

The NAM has an interesting solution...MCS events are a lot harder to forecast from this range but the pattern does support the development of one on the edge of the ballooning mid level ridge. I'm confident there will be organized strong storms around Thurs/thurs night, where they end up exactly is anyone's guess right now.

Link to comment
Share on other sites

I actually think Thursday looks to be the more active day, the 18z NAM has the 1003mb low pressure system over PA/NY and the 18z GFS has a 993mb low over NY, GFS seems more impressive, this storm system on Thursday/Friday time period looks far more dangerous then today's storm system, unlike today in most the risk area, the environment will not be capped, i agree a fairly significant tornado event could be possible

Agreed, I immediately posted after that I meant to say Thursday. Much more impressive synoptic set up versus today; let's hope it produces. As John noted the shear and helicity parameters look to be quite conducive, in conjunction with the temp/moisture advection into the area throughout the afternoon, spiking instability parameters.

Link to comment
Share on other sites

Thursday is an interesting situation, the first thing that caught my eye was the strong LLJ (especially for July) and the potential for backed sfc winds, which would create a lot of LL turning considering the southwesterly LLJ at 35-50 kts. Synoptically, definitely some potential here, the position/strength of the sfc low/warm front (and subtle adjustments to it) is obviously going to make a big difference with the possible magnitude of this event.

Earthlight raised a good point with the first point on this page, although I'd actually expect some stronger instability than the GFS depicts given the intensity of the LLJ streaming northward throughout the day.

The NAM has an entirely different look, though. Will await the 00z Euro to comment further.

Link to comment
Share on other sites

Thursday is an interesting situation, the first thing that caught my eye was the strong LLJ (especially for July) and the potential for backed sfc winds, which would create a lot of LL turning considering the southwesterly LLJ at 35-50 kts. Synoptically, definitely some potential here, the position/strength of the sfc low/warm front (and subtle adjustments to it) is obviously going to make a big difference with the possible magnitude of this event.

Earthlight raised a good point with the first point on this page, although I'd actually expect some stronger instability than the GFS depicts given the intensity of the LLJ streaming northward throughout the day.

The NAM has an entirely different look, though. Will await the 00z Euro to comment further.

I agree, we have to wait for further model agreement and things to pan out, this has to be a potential to be a significant event from the Upper Ohio Valley/Appalachians to the Northeast/Mid Atlantic, today's situation was much weaker and marginal then what's being shown on Thursday

Link to comment
Share on other sites

i agree with john, isotherm and bluewave. thursday if the imgredients all come together as far as the location of the surface low, cold/warm front we could be in for some intense severe weather from PA, to the coast into new england. im not sure of the comparison, but last year we had a similar setup where we were in the bullseye for a big severe outbreak and new england got it including that live streamed feed of the springfield,ma tornado. my only concern is that this surface low does track too far to the north and we miss alot if not all the parameters to create and sustain severe weather for our area including coastal areas. the ingredients are there now we just gotta see where they can maximize there potential. hoping this doesnt go north, because this outbreak could finally make some people who have missed out this year have a smie like me lol

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...