5/28 Day I Of Multiple Days Of Enhanced Thunder Obs, Take That You Stinkin' 90s.

[Rainshadow]

Thread title caveat, I know today is the only day we are in enhanced threat for severe, more about greater than climo thunder chances, than type of thunder.

...Ohio to New Jersey...
   Convection and associated cloud cover is progged to be ongoing
   across portions of the risk area at the start of the period, ahead
   of a surface low moving slowly east across the Lake Erie vicinity. 
   The convection should move eastward/diminish through midday,
   allowing some heating/destabilization to occur -- fueling new storm
   development, likely by early afternoon.  Storms development may be
   focused by the presence of remnant outflow associated with the
   earlier storms, though coherence -- and location -- of this possible
   boundary remains uncertain, dependent upon evolution of the ongoing
   convection.

   With fast/weakly veering west to west-northwesterly flow with height
   progged atop the region, clusters of organized/fast-moving storms
   are expected to evolve.  At this time, damaging winds would appear
   to be the primary severe risk, along with hail.  Tornado threat
   should be somewhat limited by only modest veering of the flow with
   height, but ample low-level speed shear suggests low-probability
   tornado risk during the afternoon.

   With regeneration of successive bands of storms possible, within the
   west-northwesterly flow regime, severe risk will likely linger
   through the evening and possibly into the overnight hours.

[Rainshadow]

IMO this is pretty much the start of our severe weather season. Thru the end of July it is tough to have ongoing thunder in the afternoon or first half of the evening and not have at least one go severe.  June from what I remember was the absolute best (or worst depending on your opinion) for this.

 

 

[Rainshadow]

And here we go....

[mshaffer526]

0.07" from this morning's quick line, just about doubled our two-week rain total.

[irishbri74]

3 minutes ago, Rainshadow said:

And here we go....

Moving through faster than I thought. Was thinking 9-11 time frame. 

 

Def some clearing behind it if this plows through. Guess we’ll know by 11-12.

[Rainshadow]

1 minute ago, irishbri74 said:

Moving through faster than I thought. Was thinking 9-11 time frame. 

 

Def some clearing behind it if this plows through. Guess we’ll know by 11-12.

Plus Tom will remind us the days are pretty long now and there is plenty of time for air mass recovery.

[Rainshadow]

I know this is kind of a captain obvious post, but just using the SigEff Tornado as a proxy for the time of the strongest storms, it is late this afternoon just in the warm sector.  I saw model forecast dew points in the 70s, so if you are checking activity, make sure the dew points look representative.  (Lack of) Shear not an issue.

 

 

[Chubbs]

0.15", some partial clearing - 63F

[mshaffer526]

Dayton got hit really hard last night.

https://www.accuweather.com/en/weather-news/large-destructive-tornado-strikes-dayton-as-severe-storms-ravage-ohio/70008380

[Chubbs]

5 minutes ago, mshaffer526 said:

Dayton got hit really hard last night.

https://www.accuweather.com/en/weather-news/large-destructive-tornado-strikes-dayton-as-severe-storms-ravage-ohio/70008380

Many tornadoes in Ill/Ind/OH with this sytem.

https://www.spc.noaa.gov/climo/reports/190527_rpts.html

[snowlurker]

So my wife says, as she's leaving for work, can you please take down the mini flags lining the street before it rains?

45 minutes later...

 

[irishbri74]

19 minutes ago, Chubbs said:

Many tornadoes in Ill/Ind/OH with this sytem.

https://www.spc.noaa.gov/climo/reports/190527_rpts.html

Yea. I followed it as it unfolded. Big time debris ball showed up on radar , then again 55 mins later.

[irishbri74]

But back home, check out the 3k name for 21z in sepa. Have to wonder what that stuff out west of state college will do. Too early and we don’t recover enough, as well as cloud debris. Notice that our EML has survival bed a bit better than last event. (Bottom left of the sounding. 700-500mb LR @ 6.8°c/km

[irishbri74]

 

 

SPC update a little late this am (5 mins). We’ll see if they expand the enh risk 

 

edit. Think we just got upgraded to enhanced for all of EPA/SEPA

[irishbri74]

Upgrade confirmed!

 

 With fast/weakly veering west to west-northwesterly flow with height
   progged atop the region, clusters of organized/fast-moving storms
   are expected to evolve. This could include splitting supercells,
   particularly before more linearly organized clusters/bow evolve. At
   this time, damaging winds would appear to be the primary severe
   risk, along with severe hail. Tornado threat should be somewhat
   limited by only modest veering of the flow with height, but ample
   low-level speed shear suggests at least some possibility for a
   tornado or two during the afternoon. With regeneration of successive
   bands of storms possible, within the west-northwesterly flow regime,
   severe risk will likely linger through the evening and possibly into
   the overnight hours.

   ..Guyer/Broyles.. 05/28/2019

[Rainshadow]

39 minutes ago, irishbri74 said:

Upgrade confirmed!

 

 With fast/weakly veering west to west-northwesterly flow with height
   progged atop the region, clusters of organized/fast-moving storms
   are expected to evolve. This could include splitting supercells,
   particularly before more linearly organized clusters/bow evolve. At
   this time, damaging winds would appear to be the primary severe
   risk, along with severe hail. Tornado threat should be somewhat
   limited by only modest veering of the flow with height, but ample
   low-level speed shear suggests at least some possibility for a
   tornado or two during the afternoon. With regeneration of successive
   bands of storms possible, within the west-northwesterly flow regime,
   severe risk will likely linger through the evening and possibly into
   the overnight hours.

   ..Guyer/Broyles.. 05/28/2019

I don't think I have seen an enhanced not surrounded by a slight before.  0.15" already today 2nd most we have had on any day since May 14th.

[jmister]

4 minutes ago, Rainshadow said:

I don't think I have seen an enhanced not surrounded by a slight before.  0.15" already today 2nd most we have had on any day since May 14th.

I was thinking the same thing, but the SPC has since cleaned up their outlook graphic.

[frankdp23]

Finished with .52" with the first batch here.

[cbelke]

.23" so far.

Nothing even remotely severe out of the line this morning. May have sucked some life out of this afternoons storms as well.

[irishbri74]

Some clearing now showing up just to our west. Let’s see how far north and east it makes it 

[mshaffer526]

Dews up from 52 this morning to 68.5 now.  Steamy.

[greg ralls]

As I mentioned in the general thunderstorms thread before I saw the dedicated thread to the Enhanced Risk:

Poured all along Germantown Pike from Collegeville to Plymouth Meeting between 8-9 AM, so would that be more likely to inhibit severe development later or perhaps enhance it by setting up a boundary? Or is it really more dependent upon how much clearing happens over the next several hours? Still quite overcast here in Plymouth Meeting.

[jmister]

https://www.spc.noaa.gov/products/md/md0852.html

95%  chance of tornado watch...

 

Mesoscale Discussion 852

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Mesoscale Discussion 0852 NWS Storm Prediction Center Norman OK 1202 PM CDT Tue May 28 2019 Areas affected...portions of the Mid-Atlantic into the Northeast Concerning...Severe potential...Tornado Watch likely Valid 281702Z - 281900Z Probability of Watch Issuance...95 percent SUMMARY...Storms are expected to develop this afternoon and will likely become severe. Large hail, damaging wind gusts, and a few tornadoes are possible. A tornado watch will likely be issued in the next couple of hours. DISCUSSION...A belt of enhanced mid-level westerly flow of 50-70 knots is stretching across the Great Lakes into the Mid-Atlantic/Northeast. A shortwave trough embedded within this zonal flow currently entering the Great Lakes region will move eastward throughout the day helping to provide forcing for ascent and strengthen deep layer shear. A surface low is located just east-southeast of Buffalo, NY with a warm front stretching to the southeast through northeast PA and central NJ. This warm front should lift east-northeast with the surface low forecast to track generally eastward. The Cu field is becoming increasingly agitated within the warm sector and storms are likely to develop in the next couple of hours. Storms are likely to develop across west/central PA and move east-southeast during the afternoon and evening into portions of NJ/MD/DE/southern NY. Supercell development is likely and few storms may remain discrete. Low-level veering is better to south/east across the region, but flow/shear is stronger farther to the north. Large hail is possible given forecast MLCAPE of 1500-3000 J/kg and effective bulk shear of 35-50 knots. Additionally, strong synoptic winds and steepening low-level lapse rates, especially where strong insolation occurs, will increase the severe wind threat. Tornadoes are possible as well, especially for storms that exhibit more southeast movement, which will maximize SRH per observed/forecast soundings. ..Nauslar/Thompson.. 05/28/2019 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...OKX...PHI...BGM...AKQ...BUF...CTP...LWX...PBZ... CLE... LAT...LON 39767949 39848040 40378054 40878056 41458043 41818024 42007982 42057791 41957629 41447465 41257439 40837422 40457419 39887453 38977511 38587554 39077680 39307738 39767949

[Chubbs]

Non-zero tornado probs even with limited sun due to backed winds. Key will be initiation.

[Rainshadow]

2 minutes ago, jmister said:

https://www.spc.noaa.gov/products/md/md0852.html

95%  chance of tornado watch...

 

Mesoscale Discussion 852

< Previous MD         Next MD >

Mesoscale Discussion 0852 NWS Storm Prediction Center Norman OK 1202 PM CDT Tue May 28 2019 Areas affected...portions of the Mid-Atlantic into the Northeast Concerning...Severe potential...Tornado Watch likely Valid 281702Z - 281900Z Probability of Watch Issuance...95 percent SUMMARY...Storms are expected to develop this afternoon and will likely become severe. Large hail, damaging wind gusts, and a few tornadoes are possible. A tornado watch will likely be issued in the next couple of hours. DISCUSSION...A belt of enhanced mid-level westerly flow of 50-70 knots is stretching across the Great Lakes into the Mid-Atlantic/Northeast. A shortwave trough embedded within this zonal flow currently entering the Great Lakes region will move eastward throughout the day helping to provide forcing for ascent and strengthen deep layer shear. A surface low is located just east-southeast of Buffalo, NY with a warm front stretching to the southeast through northeast PA and central NJ. This warm front should lift east-northeast with the surface low forecast to track generally eastward. The Cu field is becoming increasingly agitated within the warm sector and storms are likely to develop in the next couple of hours. Storms are likely to develop across west/central PA and move east-southeast during the afternoon and evening into portions of NJ/MD/DE/southern NY. Supercell development is likely and few storms may remain discrete. Low-level veering is better to south/east across the region, but flow/shear is stronger farther to the north. Large hail is possible given forecast MLCAPE of 1500-3000 J/kg and effective bulk shear of 35-50 knots. Additionally, strong synoptic winds and steepening low-level lapse rates, especially where strong insolation occurs, will increase the severe wind threat. Tornadoes are possible as well, especially for storms that exhibit more southeast movement, which will maximize SRH per observed/forecast soundings. ..Nauslar/Thompson.. 05/28/2019 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...OKX...PHI...BGM...AKQ...BUF...CTP...LWX...PBZ... CLE... LAT...LON 39767949 39848040 40378054 40878056 41458043 41818024 42007982 42057791 41957629 41447465 41257439 40837422 40457419 39887453 38977511 38587554 39077680 39307738 39767949

You guys are too fast, or I am too slow.