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Delaware Valley Severe/Strong/Lightning Threat Thread


phlwx

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Got split again in Wayne. It seems like the only time we get hit is with a solid West to east moving squall line. I don't think we have had a pop up storm all year. Looks like almost 1.5" so far from Caln to Uwchlan.

You're having about as good of luck as I am with storms this year. Everything either splits or dies out over eastern Schuylkill County or forms to the south and east of us.

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Got split again in Wayne. It seems like the only time we get hit is with a solid West to east moving squall line. I don't think we have had a pop up storm all year. Looks like almost 1.5" so far from Caln to Uwchlan.

negative, back in may had 3-4 inches over the area. I remember jrodd posted a video of the wawa flooded. Welcome to summer t storms, some get hit some dont.

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Right now Tuesday looks better than last Friday did imo. I have to admit, I'm having trouble pinpointing the source of lift, since there isn't an obvious thermal gradient or surface pressure trough, but at 850 mb things become clearer.

We actually have some better shear to work with (directional anyway, nasomuch speed). The 0z NAM is throwing out a north-south axis of >150 0-3 km SRH just west of the immediate Philly region, thanks to a sligh backing of the surface flow. Sure, this hodo isn't April on the Plains, but for Philly in August it holds the potential for at least some supercellular organization. (Slower 700 mb flow than 850 mb flow would suggest a lot of splitting, but we'll take what we can get I suppose.)

NAM_218_2012081300_F48_40.0000N_75.0000W_HODO.png

The column is not completely saturated this go around, although it is still quite moist, which in turn puts a damper (if you'll pardon the pun) on mid-level lapse rates and associated CAPE values.

That said, I like Tuesday better than I ever liked last Friday, and I wouldn't be surprised if we get slighted at 6z.

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we're under a 15% for tomorrow. NAM/EC all suggest the "best" potential for thunderstorms and for heavier rain is to the north/west of the city. EC says up to 2" along/east of the susquehanna river. NAM says 2-4" of localized heavy rain possible east of Harrisburg.

700mb flow is 20 kts in Central PA, 15 kts locally. 500 ain't much faster...we could see any development move very slowly.

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we're under a 15% for tomorrow. NAM/EC all suggest the "best" potential for thunderstorms and for heavier rain is to the north/west of the city. EC says up to 2" along/east of the susquehanna river. NAM says 2-4" of localized heavy rain possible east of Harrisburg.

700mb flow is 20 kts in Central PA, 15 kts locally. 500 ain't much faster...we could see any development move very slowly.

Well, it has found a way to rain with almost any possible threat atleast up our way the past month. Closing in on 9" of rain since mid-July.

I also took a stroll yesterday in Rofo (near my old apartment at Walnut Crossing) and saw several large tree limbs down, I guess from the storms in the past week.

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Well, it has found a way to rain with almost any possible threat atleast up our way the past month. Closing in on 9" of rain since mid-July.

I also took a stroll yesterday in Rofo (near my old apartment at Walnut Crossing) and saw several large tree limbs down, I guess from the storms in the past week.

I think those were from Thursday's storms...there were a few downed trees in that corridor from 422 up to Ridge Pike from Sanatoga down to 113. PTW gusted to 52...I know my office got hammered from that storm.

We walked along the Schuylkill down from 113 to Lock 60 on Saturday and the river was higher (not super high, but it was up a bit). Probably will get another bump with tomorrow's fun.

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we're under a 15% for tomorrow. NAM/EC all suggest the "best" potential for thunderstorms and for heavier rain is to the north/west of the city. EC says up to 2" along/east of the susquehanna river. NAM says 2-4" of localized heavy rain possible east of Harrisburg.

700mb flow is 20 kts in Central PA, 15 kts locally. 500 ain't much faster...we could see any development move very slowly.

Agree on the slow movement in fact would not be surprised to see flash flooding in the Harrisburg area If we are lucky maybe we can get in on some of the banding later in the night tomorrow night.

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I think those were from Thursday's storms...there were a few downed trees in that corridor from 422 up to Ridge Pike from Sanatoga down to 113. PTW gusted to 52...I know my office got hammered from that storm.

We walked along the Schuylkill down from 113 to Lock 60 on Saturday and the river was higher (not super high, but it was up a bit). Probably will get another bump with tomorrow's fun.

Damn, 52 mph at PTW? Sweet.

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Lancaster, Wilmington, Millville, Vineland and the whole state of Delaware are in a 5% TOR for tomorrow.

day1probotlk_20120814_1200_torn_prt.gif

Up close and personal: http://wdssii.nssl.noaa.gov/maps/

...MID-ATLANTIC REGION...

WHILE ONGOING CLOUD COVER -- AND PERHAPS EARLY-PERIOD PRECIPITATION

-- SHOULD HINDER HEATING AT LEAST SOMEWHAT...SOME AFTERNOON

DESTABILIZATION IS FORECAST ACROSS THE MID-ATLANTIC REGION AND SWD

ACROSS THE CAROLINAS -- AIDED BY A MOIST BOUNDARY LAYER.

WHILE THE SURFACE PATTERN IS FORECAST TO REMAIN GENERALLY WEAK...THE

NAM -- AND TO SOME DEGREE THE 4 KM WRF AND THE GFS -- SUGGEST A WEAK

LOW INVOF THE NRN VA/MD AREA. THIS LOW -- AND THE BACKED LOW-LEVEL

FLOW JUST N OF IT -- COULD FOCUS AN AREA OF STRONGER STORMS DURING

THE AFTERNOON. WHILE MID-LEVEL FLOW IS PROGGED TO REMAIN MODERATE

AT BEST...THE BACKED LOW-LEVEL FLOW COULD YIELD A SMALL ZONE OF

ENHANCED POTENTIAL FOR A TORNADO OR TWO...ALONG WITH BROADER THREAT

FOR LOCALLY GUSTY/DAMAGING WINDS. WHILE A LESSER THREAT APPEARS TO

EXIST SWD ACROSS THE CAROLINAS...WILL FOCUS THE HIGHER

PROBABILITY/SLIGHT RISK THREAT ACROSS ERN PA AND INTO THE MD/NRN

VA/DE VICINITY THROUGH EARLY EVENING.

Very interesting discussion. Delaware is so easily chase-able that I'm temped to set up down there tomorrow. (I would need greater than expected surface heating for me to actually pull the trigger though.)

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Meanwhile, the SPC WRF says we'll be dealing with a surprise line of storms by 12z already (it has what's out on the spine of the mountains now intensifying overnight).

refd_1000m_f12.gif

This scenario is not supported by the HRRR (which has a more broad, east-west oriented area of lighter rain).

The NMM and ARW both have this as well, although both have the feature really losing steam as it gets east of the Susquehanna River or thereabouts. The NSSL WRF is essentially the same as the SPC WRF.

Of all the hi-res-es, the ARW is (surprisingly, imo) the only one that develops anything north of the Mason-Dixon Line this evening.

Previous SPC discussions mentioned lack of convergence along the front as a limiting factor, and combined with meager instability as a result of morning cloud/shower debris, it seems like the hi-res-es are picking up on this as the cause for a general bust for this threat.

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Lancaster, Wilmington, Millville, Vineland and the whole state of Delaware are in a 5% TOR for tomorrow.

day1probotlk_20120814_1200_torn_prt.gif

Up close and personal: http://wdssii.nssl.noaa.gov/maps/

Very interesting discussion. Delaware is so easily chase-able that I'm temped to set up down there tomorrow. (I would need greater than expected surface heating for me to actually pull the trigger though.)

I was thinking the same. However, gonna see if anything discrete can pop, gonna be the best chance. Chances are I prob won't go. Lol.

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Lancaster, Wilmington, Millville, Vineland and the whole state of Delaware are in a 5% TOR for tomorrow.

day1probotlk_20120814_1200_torn_prt.gif

Up close and personal: http://wdssii.nssl.noaa.gov/maps/

Very interesting discussion. Delaware is so easily chase-able that I'm temped to set up down there tomorrow. (I would need greater than expected surface heating for me to actually pull the trigger though.)

Of course, has to be on my drill night at the FD. I may just have to miss it, if things get really rocking and rolling, and that 5% in my backyard.

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Meanwhile, the SPC WRF says we'll be dealing with a surprise line of storms by 12z already (it has what's out on the spine of the mountains now intensifying overnight).

refd_1000m_f12.gif

That was starting to show on the 6z NAM yesterday...and reality is it's there this AM across Central PA (most of it probably goes north of the city but some may graze through Philly proper later on).

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Having some light to moderate rain with thunder at the present time. The current radar presentation over central and eastern PA looks very similar to the image you posted.

Meanwhile, the SPC WRF says we'll be dealing with a surprise line of storms by 12z already (it has what's out on the spine of the mountains now intensifying overnight).

refd_1000m_f12.gif

This scenario is not supported by the HRRR (which has a more broad, east-west oriented area of lighter rain).

The NMM and ARW both have this as well, although both have the feature really losing steam as it gets east of the Susquehanna River or thereabouts. The NSSL WRF is essentially the same as the SPC WRF.

Of all the hi-res-es, the ARW is (surprisingly, imo) the only one that develops anything north of the Mason-Dixon Line this evening.

Previous SPC discussions mentioned lack of convergence along the front as a limiting factor, and combined with meager instability as a result of morning cloud/shower debris, it seems like the hi-res-es are picking up on this as the cause for a general bust for this threat.

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