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Damage In Tolland

Severe Wx Threat July 13

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Wiz must have spent another day in the hot tub with his jacket and hood on . Big potential in SNE tomorrow 

And it`s in the afternoon when a
severe/hydro threat should start to evolve and escalate, as
improving wind fields leading to bulk shear values rising to 35-40
kt, moderate convective instability and forcing with the stronger
upper disturbance should result in scattered to numerous showers and
storms along the frontal boundary. This is indicated by the majority
of the convective-allowing model members comprising the HREF. While
individual models vary on the timing, it appears that thunderstorms
may start to percolate as soon as 1 PM, but the better chances lie
after 2-3 PM, with greater numbers of storms then progressing
eastward towards the coast into the evening rush hour.

The largest uncertainties to the forecast hinge on the location of
the frontal zone, how quickly it progresses eastward, and while
early-day rains don`t look to be as widespread as the GFS paints it
to be, the extent to which the airmass can destabilize in the wake
of the early showers is a question mark. Exactly where the SW-NE
oriented front sets up is uncertain, but it appears to align itself
somewhere from I-84 to I-495/I-93 corridor or just west of that
line. In some of the NAM-based guidance, a weak low/mesolow ripples
along the front as storms begin to fire. If that materializes it
would serve to slow the front down further, but also back surface to
low-level winds slightly leading to somewhat longer lower-level
hodographs.

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Nice have the 3k Nam on board . Probably a spin or two pike region to 84

 

On the severe-storm potential, much of Southern New England is
highlighted in a Marginal Risk for severe. Mid-level lapse rates
look fairly weak and is a limitation. Progged CAPEs are on the order
of 1500-2500 J/kg, with bulk shear around 35-40 kt. SPC`s SREF
Craven-Brooks severe index parameter highlighting solid
probabilities for values at or over 10,000 units, which can favor
strong/severe storms. The 12z HREF continues to show some 2-5 km
Updraft Helicity swaths as well, though mainly across central and
eastern MA. Though the primary severe threat would be from strong to
locally damaging straight line winds, if a weak surface wave low can
lead to locally backed surface winds it could yield a very low-prob
tornado risk but the threat is conditioned upon that occurring. The
NAM-3 km hints at this more than other models with 0-1 km shear of
20 kt/0-1 km SRH 100-150 units in parts of the interior.

 

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23 minutes ago, Dr. Dews said:

Looks like a marginal risk at best. 

Yeah, I would like to see the 00z HREF start honking more if there is any hope at an upgrade. Right now looking more like isolated severe. 

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1 hour ago, Damage In Tolland said:

Well maybe Loconto went wild LWW?

Legro says nada . It’s SNE , so he’s probably right 

A marginally dangerous day.

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2 hours ago, Damage In Tolland said:

Well maybe Loconto went wild LWW?

Legro says nada . It’s SNE , so he’s probably right 

I wouldn't say that AFD went wild, but it describes a model that went wild. I'm just not all in on a NAM 3 km solution. 

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5 minutes ago, OceanStWx said:

I wouldn't say that AFD went wild, but it describes a model that went wild. I'm just not all in on a NAM 3 km solution. 

Have another stout and look again.............:lol:

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This looked a bit better Thursday or Friday. We really just can't buy anything. Today seems to favor eastern areas...southern ME, NH, and eastern MA. Looks like that's where the better overlap of CAPE/shear will exist and perhaps some better convergence. So perhaps some damaging wind gusts out that way. 

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20 minutes ago, weatherwiz said:

This looked a bit better Thursday or Friday. We really just can't buy anything. Today seems to favor eastern areas...southern ME, NH, and eastern MA. Looks like that's where the better overlap of CAPE/shear will exist and perhaps some better convergence. So perhaps some damaging wind gusts out that way. 

I was on board with this until about an hour ago. Current radar and sunny morning make me think central and west could have a decent shot.

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6 minutes ago, PowderBeard said:

I was on board with this until about an hour ago. Current radar and sunny morning make me think central and west could have a decent shot.

Only issue with western areas is shear looks to decrease. Also looks like there could be a decent instability gradient across eastern areas and sometimes those areas can be favorable locations. Looks like the HRRR wants to favor eastern sections with more isolated activity further west. 

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I like today’s severe threat for eastern half. Clouds are breaking up. All meso guidance still clearly on board. The show is in the afternoon. :popcorn:

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I’d like to meh my way to severe today but I don’t think it’s going to happen. No meteorological reasoning other than the thick overcast 

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5 minutes ago, Chrisrotary12 said:

We overcast. Next.

Pretty good clearing punching into ORH now....most of SNE should be in the sun soon.

RAP/HRRR do show some action for eastern areas this afternoon so we'll see.

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Two schools ... sort of offset optimism:

in one regard the ML lapse-rates I don't "think" are very good today?  They really can't be because the primary frontal slope's now E of the coast by a hair and that means that the antecedent thermal dynamic profile ( pre frontal..) is now mid tropospheric/dispersive above the boundary, and that should be a CIN factor... That said, there could also be intervening layers that offer some instability via evaporative cooling from early turret decay and then sequencing bubbling up ... in other words, the post frontal evironment isn't very convincing 'scrubbing' the air mass, either. 

in the other regard, ...our climo is usually requiring forced ascent to overcome what is typically poorer SB CAPE to ml d(t) ...which seems to really be the magic ratio for me/ years of observation... Lot of factors contribute, but >50% of the day's success in the Plains is almost always llv CAPE up under a cool/cooling mid level temperature... One overcoming factor though is fluid mechanical lift.. perhaps some ratio of decreasing ML lapse rates/mitigation is then in turn offset by diffluence aloft.  You can see there's the latter on early satellite, with cirrus streaks kiting right along over the top of a mid level showers that are not exactly slowly moving through in their own rights... all over a surface that's almost calm... so there's tilting/pulling  

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9 minutes ago, ORH_wxman said:

Pretty good clearing punching into ORH now....most of SNE should be in the sun soon.

RAP/HRRR do show some action for eastern areas this afternoon so we'll see.

Blue sky dominates here, helluva muggy. Early swim helped 

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13 minutes ago, ORH_wxman said:

Pretty good clearing punching into ORH now....most of SNE should be in the sun soon.

RAP/HRRR do show some action for eastern areas this afternoon so we'll see.

Really inconsistent on location looking on HRRR. Probably will be able to see boundary well on mesonet later on.

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