July 26, 2012 Severe Weather Potential

[LongBeachSurfFreak]

http://en.wikipedia....or_Day_Derechos ?

Interesting I didn't realize that the Labor Day storm was considered a derecho. My favorite thunderstorm of all time!

[Rtd208]

Sun is starting to peek out here, airmass will begin to rapidly destabilize over the next few hours.

[NorEaster27]

While those SIM radars are nice, lets not get too caught up in them. We are still waiting for the WF to pass and for some sun. We still have no surface based CAP and lapse rates are poor.

[CT Rain]

Here's the 4km WRF from WSI

Nice snag

[IsentropicLift]

Can i get a MOTHER OF GOD??? That will do some damage.

Whats the timing on that

Indeed, if that were to verify we would be dealing with some serious winds and the lower half moving through Jersey looks like a big time hail producer if nothing else, but it's just another model.

[HailMan06]

Full, hazy sunshine now. It got noticibly muggier as well.

[bluewave]

Here's the 4km WRF from WSI

Here's the view from PSU:

[NEG NAO]

going to be quiet for the next few hours on the radar and any severe watches for NYC metro will probably not be issued till this afternoon some time and probably cover a major portion of the evening and overnight hours

[Superstorm93]

Here's the view from PSU:

The RPM is a completely different (and private) model.

[earthlight]

Getting hot and humid fast out there -- we've got bright sun now..still a few clouds burning off but with the clearing expected to continue, 11:30am is not a bad start time for building instability.

[bluewave]

The RPM is a completely different (and private) model.

Same theme as the NAM though. Crazy rear inflow jet developing with that sucker.

[LocoAko]

FWIW, the 12Z HRRR doesn't seem overly gung ho on a very organized squall line/derecho tonight. It does bring through a cluster of storms from NE PA through NYC this evening which would probably be severe but there is very little updraft helicity being forecast in any isolated storms earlier in the day and maximum 10m wind gusts only get up to isolated 40 kts in NW NJ and weakening there on out. Not sure on the HRRR's track record when it comes to forecasting such intricacies. I wouldn't put TOO much stock in it at this point.

[MJO812]

Mostly sunny here. Getting humid.

[Superstorm93]

WRT the HRRR. it still had a convective complex in it's earlier forecast hours.

Im more interested to see what it does when it assimilates all this clearing going on.

[LocoAko]

WRT the HRRR. it still had a convective complex in it's earlier forecast hours.

Im more interested to see what it does when it assimilates all this clearing going on.

Very true - the complex has dissipated much more rapidly than the 12Z HRRR shows. These ultra hi-res mesoscale models are always so tempting to overanalyze. Oy vey.

[blizzardof09]

Here's the 4km WRF from WSI

Wow! Just wow, that line would do alot of damage on long island widespread from nassua and suffolk. Its just a model i know but that is one dangerous line

[IntenseBlizzard2014]

It's 74F with a dewpoint of 69F

[Superstorm93]

Getting some sun here now.

Those NE folks must be pretty sour.

[Brian5671]

Western NE is in the game....

[TheTrials]

just an amazing change in airmasses in under 24 hours. Crisp and dry yesterday, humid and unstable now.

[Superstorm93]

Radar clearing is very impressive as well.

CAPE should blossom very quickly.

[IsentropicLift]

Getting some sun here now.

Those NE folks must be pretty sour.

I've been reading through the New England thread all morning and some of the mets are really starting to think the main focus will be down by us instead of southern New England. Being in the bullseye 24 hours out isn't always the best thing.

[Snowlover11]

Still stuck in the clouds here, give or take another half hour for mostly sunny conditions.

[bluewave]

Besides the high wind potential, the PWAT's and dews forecast suggest maybe an inch of rain in 10-15 minutes

for strongest hit areas and then going up from there.

[TheTrials]

Besides the high wind potential, the PWAT's and dews forecast suggest maybe an inch of rain in 10-15 minutes

for strongest hit areas and then going up from there.

dews in the low 70's are whats feeding a lot of the instability on the soundings, and yeah, tons of liquid potential here. If any cells decide to train, epic flash flooding possible.

[TheTrials]

Sounding shows how the Tornado threat may just not all come together, but the straight line wind threat and bow segment threat sure is

[Isotherm]

Impressive that I'm at 83F without any sunshine yet. Once these clouds break in the next 30 minutes we should spike quickly into the 90s.

[Superstorm93]

Sounding shows how the Tornado threat may just not all come together, but the straight line wind threat and bow segment threat sure is

I can't speak for everyone here, but a tornado is the last thing I want to see in this highly populated region. Damaging winds are probably the best you can get here without too much destruction.

Now SNY is different. If I see some hooks ahead of the line later, I'm headed north no matter what the circumstance.

[Hailstorm]

Wow, craven/brooks #s and supercell parameterd are really ramping up in western PA and spreading east. We already have over 200 m2/s2 of helicity over the area with 45+ kt. bulk shear and increasing theta-e advection.

[Dsnowx53]

The directional shear might not be enough for tornadoes, but if we can get localized backing north or northwest of the city, where the surface winds locally turn to the south instead of southwest, that's where you have to watch out. This is where surface based helicity can locally be enhanced.

A widespread tornado event is unlikely given the primarily west of south surface winds.