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DC/MD/VA Thunderstorm Obs/Disco 6/28/11


HoCoSnowBo

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Did you mean east? ;)

Ideally I'll find a place where the cops wont be all up on me and someplace where I'm not attracting a ton of attention. I always miss these things due to lack of good places.

Parking garages are the way to go. I use them for my lightning/storm shots all the time. Metro stations (Grosvenor, White Flint, Shady Grove, Glenmont) are always a good bet, and there are numerous other ones, especially on Rockville Pike.

The White Flint garage is especially good if you want a good view to the Southeast for the rocket.

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Parking garages are the way to go. I use them for my lightning/storm shots all the time. Metro stations (Grosvenor, White Flint, Shady Grove, Glenmont) are always a good bet, and there are numerous other ones, especially on Rockville Pike.

The White Flint garage is especially good if you want a good view to the Southeast for the rocket.

i might try to get the capitol and it... tho im sure we'll have clouds. :axe:

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The 2% to our N is fine... I just don't see DC/MD/NoVA getting in on the TOR risk. LL winds do some veering in the lowest levels, but wind speeds themselves are weak. combine that with a lack of stronger UL winds and you've got pulsers that can't stay organized long enough to get strong rotation.

Going into NoPA/SoNY, you hit crappy lapse rates that will keep updrafts relatively weak, which will also work against tornado development (though in areas in PA with higher CAPE and better UL support we could see a TOR).

Obviously, there will (hopefully) not be a tornado outbreak / long tracked tornadoes in the DC area today or points north. But LL lapse rates are improving all the way into Canada and the mid level lapse rates will continue to improve as the ULL translates east (500mb CAA and 700mb WAA as per latest SPC RUC analysis).

There is some real shear now (effective shear even!) into N VA > 30 kts. Again, thats not too impressive, but it would be sufficient for storm organization, especially with > 2000 j/kg SBCAPE.

If I worked at SPC, I would cut out South Carolina and W North Carolina from the slight and connect the Eastern NC/VA slight with the NY/PA one.

Of Note: My timing before seems to be ~ 2 hours slow since storms have formed over southern WV and along the lake breeze/ cold front in PA/NY. Specifically, the shear over the WV storms is very low; I expect them to pulse out in the next hour which SHOULD send an outflow boundary into N VA = storm initiation for that area.

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Obviously, there will (hopefully) not be a tornado outbreak / long tracked tornadoes in the DC area today or points north. But LL lapse rates are improving all the way into Canada and the mid level lapse rates will continue to improve as the ULL translates east (500mb CAA and 700mb WAA as per latest SPC RUC analysis).

There is some real shear now (effective shear even!) into N VA > 30 kts. Again, thats not too impressive, but it would be sufficient for storm organization, especially with > 2000 j/kg SBCAPE.

If I worked at SPC, I would cut out South Carolina and W North Carolina from the slight and connect the Eastern NC/VA slight with the NY/PA one.

Of Note: My timing before seems to be ~ 2 hours slow since storms have formed over southern WV and along the lake breeze/ cold front in PA/NY. Specifically, the shear over the WV storms is very low; I expect them to pulse out in the next hour which SHOULD send an outflow boundary into N VA = storm initiation for that area.

I sure hope you're looking at the soundings when doing your forecast as well, because they paint a much less prettier picture (in our area).

EDIT: I'm still talking about the TOR risk...

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Parking garages are the way to go. I use them for my lightning/storm shots all the time. Metro stations (Grosvenor, White Flint, Shady Grove, Glenmont) are always a good bet, and there are numerous other ones, especially on Rockville Pike.

The White Flint garage is especially good if you want a good view to the Southeast for the rocket.

Do I need SmarTrip?

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I sure hope you're looking at the soundings when doing your forecast as well, because they paint a much less prettier picture (in our area).

EDIT: I'm still talking about the TOR risk...

Oh yea, I am, don;t worry:

http://www-frd.fsl.noaa.gov/mab/soundings/java/plot_soundings.cgi?data_source=Op40;latest=latest;start_year=2011;start_month_name=Jun;start_mday=28;start_hour=17;start_min=0;n_hrs=1.0;fcst_len=shortest;airport=dca;plot=Java-based%20plots;hydrometeors=false&start=latest

Depending on what sounding you use, we either have ~400 j/kg cape or ~2200. The bullish one is the Rapid Refresh 1-hr forecast, which is ALWAYS too bullish. the bare one is the "Op-40 Analysis" which I think is the 40-km RUC. These two profiles are very similar except the HRR has huge LL moisture and a cumulus field whereas the RUC does not. Looking outside, we know which one is closer to reality (HRR since I see a decent cum field). Doesn't guarantee anything, but does point toward YES storms later this afternoon at least.

Specifically for tornadoes, the 0-1km shear we had this AM (>20 kts) has weakened. the mesolow over South central PA is causing our winds to be W/ WNW which would NOT support a tornado threat. However, to the south and north of DC, winds have successfully recovered to be out of the S. And I still see that NW-SE orientated cumulus boundary on VIS.

It's only 2PM, we still have a few hours of heating before the storms initiate so if the lee trough can strengthen it can suck that mesolow back W and allow the DC winds to back south too.

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Seems steep... SPC Meso. Analysis page has LFC @ 1000-2000 ft. in general throughout the region.

SPC Meso also says that the 700mb temp is ~10°C. The parcel lift (CAPE) line is almost vertical at that point looking at a skew t. We're in a situation where the temperature likely sitting on top of the parcel lift line from 1400m to 3700 m resulting in neutral buoyancy.

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