Weather Threats on the Horizon: Spring 2020 Edition - Page 45 - Forecasting and Discussion - 33andrain Weather Discussion Community Jump to content
Oliviajames3

Weather Threats on the Horizon: Spring 2020 Edition

Recommended Posts

Hmm SEward moving... conventional wisdom says SE moving is  best for svr wx, while NE moving is better for heavy rain.

Share this post


Link to post
Share on other sites

First look suggests that the areas @CCB! mentioned do indeed look the most primed for this event but it's the question of where that EML sets up. I doubt it gets much further north than CPA/CNJ; but time will tell where that actually sets up.

  • Like 3

Share this post


Link to post
Share on other sites

SPC thinks the main threat tomorrow is to the southwest of the NYC metro including SE PA and S NJ which certainly appeared to be the case when it made its forecast last night. However, the 12z NAM is showing better instability and a further north track of the southeast diving vort. We'll see if that holds, but if it does, I would expect to see the threat area expanded northeast some of where it is now.

 

Cloud cover/exact destabilization are potential limiting factors

 

nam3km_z500_vort_neus_fh30_trend.gif.ededd35c47b357e9f52068c80cf82109.gif

  • Like 1

Share this post


Link to post
Share on other sites
28 minutes ago, Ace said:

SPC thinks the main threat tomorrow is to the southwest of the NYC metro including SE PA and S NJ which certainly appeared to be the case when it made its forecast last night. However, the 12z NAM is showing better instability and a further north track of the southeast diving vort. We'll see if that holds, but if it does, I would expect to see the threat area expanded northeast some of where it is now.

 

Cloud cover/exact destabilization are potential limiting factors

 

nam3km_z500_vort_neus_fh30_trend.gif.ededd35c47b357e9f52068c80cf82109.gif

I think there are some pluses & minuses to this trend, if you're looking for the axis to shift north. You pretty much cover it in this post, but I'll just add some nuance.

 

The height field shifting north should bring the "better" mesoscale parameters with it. But that also includes CIN, courtesy of the lead MCS leftover debris:

nam3km_ir_neus_fh30_trend.gif

 

That same MCS is probably partially responsible for the adjustment north anyway as its latent heat is probably pumping the ridge just a bit.

 

So I'd agree that an adjustment north in their forecast if mesoscale guidance continues to show the adjustment in the height field is probable... But as usual, the satellite will tell the story by about 1:00pm tomorrow in regards to how fast the deck can clear & if we can sufficiently destabilize.

  • Like 1

Share this post


Link to post
Share on other sites

Just another ‘severe’ season in the NYC metro. Looking forward to more great light shows to my south all summer long. 👎

  • Like 1

Share this post


Link to post
Share on other sites
1 hour ago, CCB! said:

I think there are some pluses & minuses to this trend, if you're looking for the axis to shift north. You pretty much cover it in this post, but I'll just add some nuance.

 

The height field shifting north should bring the "better" mesoscale parameters with it. But that also includes CIN, courtesy of the lead MCS leftover debris:

 

That same MCS is probably partially responsible for the adjustment north anyway as its latent heat is probably pumping the ridge just a bit.

 

So I'd agree that an adjustment north in their forecast if mesoscale guidance continues to show the adjustment in the height field is probable... But as usual, the satellite will tell the story by about 1:00pm tomorrow in regards to how fast the deck can clear & if we can sufficiently destabilize.

 

Great point. SPC did expand a bit to the northeast and added this tidbit to their discussion. Should be interesting to see how things develop.

 

 ...Lower Great Lakes into northern Mid Atlantic Coast region...
   At least some model output indicates that a belt of enhanced flow
   (30-50+ kt) in the 850-500 mb layer, associated with a convectively
   generated or enhanced perturbation, may contribute to convective
   potential as it migrates east-southeast of the lower Great Lakes
   region by early Wednesday.  This impulse may be accompanied by
   remnants of overnight convection which could impact downstream
   destabilization.  However, there appears potential for
   re-intensification, and the possible evolution of an organized
   convective system which could pose a risk for damaging wind gusts,
   severe hail and perhaps a tornado or two.  Model spread concerning
   the extent of boundary-layer destabilization remains the primary
   uncertainty resulting in the maintenance of 15 percent severe
   probabilities.  If moderate boundary-layer CAPE is able to develop,
   severe probabilities will probably need to be increased.

 

image.png.070213c4370f08d9e6f7894692c50d6c.png

  • Like 2

Share this post


Link to post
Share on other sites

The HREF/HRRR bite on the idea that the lead wave of convection will re-ignite over the area by 1/2pmish... Before peak heating, but impressive updraft helicity & instability no less.mucape_mean.ne.f03000.pnghrrr_ir_neus_31.png

  • Like 1

Share this post


Link to post
Share on other sites

HRRRv4 is interested in the lead storms as well.

 

24

25

  • Like 2

Share this post


Link to post
Share on other sites

Same w/the new HRRR:

 

24

 

Downright nasty across the OHV/SPA/Northern Mid-Atlantic tomorrow night. Many discrete cells riding right along the cold front.

 

30

32

  • Like 3

Share this post


Link to post
Share on other sites
2 minutes ago, CCB! said:

HRRRv4 is interested in the lead storms as well.

 

So is the HRRRv3. Relying on those lead storms is probably how we score some decent severe in the northern half of NJ. Its a bit slower than 12z NAM with the lead activity so that would work to our favor. We'll see what the 18z NAM show

 

hrrr_ref_frzn_neus_fh22-26.gif.57fbb6294228a49bfb75cd935c787918.gif

  • Like 1

Share this post


Link to post
Share on other sites
23 minutes ago, Ace said:

So is the HRRRv3. Relying on those lead storms is probably how we score some decent severe in the northern half of NJ. Its a bit slower than 12z NAM with the lead activity so that would work to our favor. We'll see what the 18z NAM show

 

hrrr_ref_frzn_neus_fh22-26.gif.57fbb6294228a49bfb75cd935c787918.gif

I generally prefer midday severe potential over late day in these parts... Even if it's not quite peak heating, we tend to do better on the "upswing" than down... And there's less chasing the EML. Better chance we can take advantage of that by midday/early afternoon as it'll advect ESE with the front as the day wanes. 

  • Like 2

Share this post


Link to post
Share on other sites

Ha... Maybe a bit too far N with the primary axis, but whoa. 

 

 

  • Like 2

Share this post


Link to post
Share on other sites
3 minutes ago, CCB! said:

Ha... Maybe a bit too far N with the primary axis, but whoa. 

 

 

lmao it gave me 4000 J/kg SBcape

  • Like 1

Share this post


Link to post
Share on other sites

Love the happy hour 3k 

 

Still thinking City south is in prime position for this, wouldn't be shocked to see enhanced get thrown in but can summarily see why we'd keep slight too. I'll be both too far north and probably have limited time to re-destabilize after the (presumptive) first wave.

  • Like 1

Share this post


Link to post
Share on other sites

You guys want to see fun? CNJNamNEST.png.2dfd843d0c092dfc01eb089f39139c0e.png

This is for Central NJ. Very nice curved hodo. This is as good of a sounding as you can get in these parts. Look at those lapse rates. Solid EML in place. Shear could be a bit better but this is a sounding that makes me glad that the main storm mode is linear. 

  • Like 2

Share this post


Link to post
Share on other sites

HRRRv4 certainly is modeling an active day tomorrow! Severe setups are delicate by nature so lets see how things look in the morning.

 

00Z-20200603_HRRRV4NE_prec_radar-15-28-50-100.gif.5916e5aa89e7e52cee4ffbf094d8a6e3.gif

  • Like 2

Share this post


Link to post
Share on other sites

Just for overnight tonight... Though SEPA/Trenton south look to be in the best spot at the moment. 

 

 

  • Like 2

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


×
×
  • Create New...