Central PA Spring/Summer 2019

[Bubbler86]

Up to 83 here so heat is not an issue.  Line is not far away but heavy rain wise it is not that impressive yet.  Actually quite dry here so the rain will be welcome.  

[Atomixwx]

Getting awfully dark.

[Atomixwx]

Raining in Wertzville.

[Flatheadsickness]

The first line was not to be  the main threat today . According to the Spc its the cold front that drops in in a few hours that was to trigger the main sever weather.

NWS seems to think the cold front my not initiate. On the other hand The spc still calling for multiple clusters and cellular activity this afternoon. Either way lots of changed wording and flipflopping from both nws and spc to save there ass.

[TheDreamTraveler]

Just now, Flatheadsickness said:

The first line was not to be  the main threat today . According to the Spc its the cold front that drops in in a few hours that was to trigger the main sever weather.

NWS seems to think the cold front my not initiate. On the other hand The spc still calling for multiple clusters and cellular activity this afternoon. Either way lots of changed wording and flipflopping from both nws and spc to save there ass.

Okay I was gonna say. It seemed funny that that strong line of storms died as soon as it went into the enhanced risk area lol...

[Flatheadsickness]

Spc says sheer doesn't get any stronger in this part of the world than what we have in are region today. This may be the second time this year we just missed a historical bullet. 

[Anduril]

Yea that was def disappointing. Guess we'll see what can spin up later

[Anduril]

Quote

In the wake of the first line, multiple lines and clusters of
   thunderstorms are expected to form across parts of western/central
   PA into northern WV.  Fast flow aloft and sufficient time to heat
   will result in a favorable environment for a few severe storms
   capable of damaging wind gusts and some hail.  These storms will
   track eastward and approach the east coast by dark.  While damaging
   winds are the main threat, an isolated tornado or two cannot be
   ruled out.

Per SPC

[Flatheadsickness]

per nws 

The line of fast moving convection continues to outrun the unstable air and so far the storms have underperformed in what was an enhanced outlook for severe storms. The RAP still wants to destabilize the SERN zones where a new watch is in effect. Shear remains impressive with forecast EHIs/STPs about as high as they get for this part of the world. The big question is if the Lower Susq can destabilize fast enough to feed these storms that are racing east at 40-50 mph. The second biggest question will be if new storms can manage to form over the western and northern parts of the CWA where the airmass has not been changed and dewpoints remain in the 60s. Different flavors of the HREF have differing solutions with the most pessimistic member developing a new line and taking until about 10PM to have it drop SE to the Mason-Dixon line. Some HREF members just develop some scattered activity at worst. I suspect that unless we see some upstream activity starting to spark off very soon, at worst we will see some late afternoon scattered activity and the current line will be the main event. Afternoon high temps will be several deg above normal or in the mid 70s north and lower to mid 80s in the southern valleys. What there is of any convection, either left over or yet to form, should dwindle early this evening as drier air sweeps into the forecast area. Lows will drop back into the comfortable 50s to lower 60s.

 

[Flatheadsickness]

I hope the SPC WINS THIS ONE>

[Flatheadsickness]

A few of the guys at the nws write like there at the top of there game but thats where it ends.  That said the lack of noise to the north and west has me leaning with them at this point. If storms do initiate this afternoon it will happen fast.

[Bubbler86]

Looks like DC "stole our thunder" as to today's storms.  

[Anduril]

Storms are starting to develop out in ohio

[Anduril]

Now a few cells showing up in western pa too. Could be this second front actually does pop off maybe another hour of sun too

[Anduril]

Pretty clearly see the second front thats causing the new storms to kick off

[TheDreamTraveler]

23 minutes ago, Anduril said:

Now a few cells showing up in western pa too. Could be this second front actually does pop off maybe another hour of sun too

I see that. They just came up out of nowhere in the past 45 minutes. Maybe the threat isn't done?

[Itstrainingtime]

I'm not sure which is faster right now...the speed at which they're growing or moving. They are hauling east! 

[Anduril]

SPC Agrees

Quote

.With a mid-level shortwave trough traversing the area,
   providing enhanced lift, storms have recently developed across
   portions of northwest Pennsylvania. A few of these storms have
   already exhibited transient supercell structures. With a modestly
   buoyant air mass (500-1000 J/kg MLCAPE), and favorable kinematics
   (50+ knots of effective bulk shear and 200-300 effective SRH) in
   place, additional multicellular clusters and transient supercell
   structures are expected to continue developing through the evening
   hours. Damaging wind gusts are expected to be the primary threats,
   both with multicells and supercells that develop. Given the
   aforementioned SRH environment, a tornado or two cannot be ruled out
   in addition to some marginally severe hail.

 

[Newman]

The cell passing through Johnstown and the other one SW of State College look dangerous. Definitely rotation on both and both look like supercells. Heads up Central PA folk.

[paweather5]

Tornado Warning
PAC079-103-240145-
/O.NEW.KBGM.TO.W.0011.190524T0120Z-190524T0145Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Binghamton NY
920 PM EDT Thu May 23 2019

The National Weather Service in Binghamton has issued a

* Tornado Warning for...
  Southern Luzerne County in northeastern Pennsylvania...
  South central Pike County in northeastern Pennsylvania...

* Until 945 PM EDT.

* At 920 PM EDT, a severe thunderstorm capable of producing a tornado
  was located over Pond Hill, or 7 miles east of Berwick, moving east
  at 60 mph.

  HAZARD...Tornado and quarter size hail.

[TheDreamTraveler]

Remember that severe thunderstorm watch that was supposed to expire at 8 pm but was taken off a few hours early? Well there's a new one until 12 am now.

 

[Jns2183]

Perfect summer storm. Lots of lightning and constant thunder


. Pro

[Voyager]

If it isn't raining, it's windy AF... I really wish this crazy pattern would change.

[Itstrainingtime]

Ended up with a very garden variety shower last night with literally one rumble of thunder. Nothing wrong with that! 

[pawatch]

Some decent thunder and lighting last night picked 0.50" of rain.

[TheDreamTraveler]

It's already humid as hell out there right now.

[Flatheadsickness]

< Day 1 Outlook

Day 3 Outlook >

 

May 27, 2019 1730 UTC Day 2 Convective Outlook

Updated: Mon May 27 17:30:54 UTC 2019 (Print Version |  | )

Probabilistic to Categorical Outlook Conversion Table

Day 2 Prob. Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area SIG SEVERE 90,538 7,287,914 Oklahoma City, OK...Kansas City, MO...Tulsa, OK...Wichita, KS...Lincoln, NE... 30 % 107,003 13,592,805 Kansas City, MO...Tulsa, OK...Wichita, KS...Pittsburgh, PA...Lincoln, NE... 15 % 259,222 34,872,365 Philadelphia, PA...Oklahoma City, OK...Cleveland, OH...Omaha, NE...St. Louis, MO... 5 % 244,911 59,848,044 New York, NY...Chicago, IL...Dallas, TX...Detroit, MI...Indianapolis, IN... Probability of severe weather within 25 miles of a point. Hatched Area: 10% or greater probability of significant severe weather within 25 miles of a point. (More Info)

Forecast Discussion

SPC AC 271730 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 PM CDT Mon May 27 2019 Valid 281200Z - 291200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM A PORTION OF THE SOUTHERN AND CENTRAL PLAINS TO THE UPPER MIDWEST AS WELL AS FROM OHIO INTO PENNSYLVANIA... ...SUMMARY... Severe storms (capable of large hail, damaging wind and tornadoes) are possible Tuesday from the central and southern Plains eastward to the Midwest. Severe storms with large hail, damaging wind and a couple of tornadoes are also possible from the Ohio Valley into a portion of the Northeast States Tuesday afternoon and early evening. ...Synopsis... A low-amplitude shortwave trough will move off the northeast coast Tuesday morning, while upstream a more significant upper trough will move into the central Plains before continuing northeast into the upper MS Valley region Tuesday night. By 12Z Tuesday the surface pattern should be characterized by a warm front from eastern PA northwest to a surface low over the Great Lakes. A cold or stationary front will trail southwestward from this low to another area of low pressure over the central Plains. A dryline/Pacific front will extend southward from the central Plains low through western KS and western TX. ...Southern and central Plains through the upper Midwest... Rich low-level moisture with upper 60s to around 70F dewpoints will reside in the warm sector beneath 7-8 C/km mid-level lapse rates associated with the eastward expansion of the elevated mixed layer. Some areas of stratus may reside across a portion of this region, but should mix out by late morning to early afternoon, with diabatic warming further contributing to destabilization with MLCAPE from 2000-3000 J/kg likely. Warm air at the base of the EML will likely result in at least a modest cap in much of the warm sector. By mid afternoon, forcing attending a mid-level jet moving northeast through the base of the upper trough should result in storm initiation along the Pacific front from south central NE through central KS and possibly as far south as western OK. Some CAMs also indicate a separate area of storm development along a portion of the warm conveyor belt from eastern KS into MO and southern IA. Wind profiles with 40-50 kt effective bulk shear will support supercells as the initial storm mode, but some storms will eventually evolve into linear MCSs. While low-level hodographs are forecast to remain modest most of the day, 0-1 km helicity should increase by early evening as the low-level jet strengthens. Large hail and damaging wind will be the main threats, but a window for tornadoes will exist especially from late afternoon through early evening. Overnight, most storms will have evolved into lines or clusters, but will continue to pose a severe threat as they continue east through the upper Midwest, mainly within zone of ascent along and just north of the stationary front. ...Ohio Valley into a portion of the northeast States... An area of rain and thunderstorms developing within zone of isentropic ascent on the cool side of a warm front and in association with a low-amplitude shortwave trough, will move through a portion of the Northeast States early in the day. In wake of this activity surface dewpoints in the upper 60s will advect eastward through the warm sector contributing to moderate instability (1500-2000 J/kg MLCAPE) as the boundary layer warms during the afternoon. Forecast soundings indicate at least a weak inversion associated with the eastern extension of the elevated mixed layer. However, storms will likely initiate along the stationary front as well as lake breezes and spread southeast through the warm sector. This region will remain within zone of moderate westerlies with 35-45 kt effective bulk shear supportive of organized storms including supercells and bowing line segments. Damaging wind and large hail will be the main threats with this activity, but a couple of tornadoes will also be possible through early evening. ...MAXIMUM RISK BY HAZARD... Tornado: 10% - Enhanced Wind: 30% - Enhanced Hail: 30% SIG - Enhanced ..Dial.. 05/27/2019

[Flatheadsickness]

Next posable threat after tomorrow is Thursday then it flattens off for a few days.

...DISCUSSION... A shortwave trough over the Mid-Mississippi Valley at the beginning of D4/Thursday will migrate northeast and phase with a larger scale trough over southeastern Canada. With warm/moist air in place and strong deep shear, a severe threat will exist with any convection that can develop over the Northeast (particularly New York and Pennsylvania) during the afternoon and early evening. Models are not particularly consistent with regard the location of surface features (i.e., boundaries, low pressure areas, etc.) in the region, which lends uncertainty for highlighting specific locations of a heightened threat.

 

[Flatheadsickness]

looks like three days in a row now for a good chunk of Pa. SPC just put almost all of Pa under slight risk for Wed and marginal risk for Thur but expect Thursday to be upgraded to slight by tonight . The decaying convection that is entering are area now at 5:00am should be well east of here this time in plenty of time for day time heating to destabilize the atmosphere plenty . 

 

[Newman]

Really the only wild card seems to be how well we recover from this morning rain and cloud cover for todays severe threat. Mount Holly continues to become more and more concerned on their 8am update:

 

Additionally, given the fairly
quick movement of the line of showers/storms, concern continues
to increase that the post-storm environment will quickly
recover/destabilize to support a potentially significant severe
threat this afternoon/evening, especially south of I-78.