Voyager Posted July 29, 2017 Share Posted July 29, 2017 1 hour ago, meatwad said: Nice Deformation Band setting up over Allegheny County. Popping in here after reading this to ask, who would think that one would be referencing a deformation band in a July storm??? Link to comment Share on other sites More sharing options...
CoraopolisWx Posted July 29, 2017 Share Posted July 29, 2017 2 minutes ago, Voyager said: Popping in here after reading this to ask, who would think that one would be referencing a deformation band in a July storm??? Yeah, not something we see very much. I was thinking bust earlier this evening, but then that deform band really blew up around 8:30. Link to comment Share on other sites More sharing options...
meatwad Posted July 29, 2017 Share Posted July 29, 2017 Flash Flood Warning Flash Flood Warning PAC003-051-125-129-290815- /O.NEW.KPBZ.FF.W.0073.170729T0314Z-170729T0815Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ BULLETIN - EAS ACTIVATION REQUESTED Flash Flood Warning National Weather Service Pittsburgh PA 1114 PM EDT FRI JUL 28 2017 The National Weather Service in Pittsburgh has issued a * Flash Flood Warning for... Southeastern Washington County in southwestern Pennsylvania... Southeastern Allegheny County in southwestern Pennsylvania... Southwestern Westmoreland County in southwestern Pennsylvania... Northwestern Fayette County in southwestern Pennsylvania... * Until 415 AM EDT. * At 1113 PM EDT, radar indicated heavy rain in the warned area. FLASH FLOODING... Expected. ESTIMATED RAINFALL... Up to 2 inches. ADDITIONAL RAINFALL...Up to 2 inches. * Some locations that may experience flooding include... Monroeville... Greensburg... McKeesport... Jeannette... Gastonville... Murrysville... South Park Township... Jefferson Hills... North Versailles... White Oak... Monessen... Clairton... This includes the following highways... Interstate 70 in Pennsylvania between mile markers 28 and 57. Pennsylvania Turnpike between mile markers 59 and 75. PRECAUTIONARY/PREPAREDNESS ACTIONS... Turn around, don`t drown. Most flood fatalities occur in vehicles. Be especially cautious at night, when it is harder to recognize the dangers of flooding. Please report flooding by calling 412-262-1988, posting to the NWS Pittsburgh Facebook page, or using Twitter @NWSPITTSBURGH. && LAT...LON 3997 7971 3994 7994 3995 7996 3995 8000 3996 8001 3998 8000 3998 8005 4000 8004 4001 8006 3999 8008 3999 8011 4001 8018 4000 8019 4001 8023 4000 8027 4031 7993 4042 7970 4032 7956 $$ Fries Link to comment Share on other sites More sharing options...
RitualOfTheTrout Posted July 29, 2017 Share Posted July 29, 2017 29 minutes ago, CoraopolisWx said: Yeah, not something we see very much. I was thinking bust earlier this evening, but then that deform band really blew up around 8:30. Just looking at this storm on radar one would think it was a Winter Storm... Intense rainfall right now, we finally get in on a good deform band... but its July lol. Even NWS was making comparisons to winter storm look in a previous discussion: SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/... Interesting developments during this period that are more often seen during the winter season. As the upper low drops across western PA tonight and toward the Delmarva area Saturday, the system takes on a more neutral tilt with time. Very strong U-component anomalies, around 4 standard deviations on the NAEFS, will promote moist onshore flow into the ridges. There is also a clear trowal signal over PA late tonight and into Saturday in the 700-500 mb layer. This all points to an unusually strong summertime synoptic setup that could result in excessive rainfall over parts of the area, particularly the ridges. Have continued with the highest PoPs in this region, tapering off to the northwest. The system will only slowly pull away with time, with a few showers lingering into Saturday night southeast of Pittsburgh, before finally ending overnight. Link to comment Share on other sites More sharing options...
blackngoldrules Posted July 29, 2017 Share Posted July 29, 2017 Flooding all over the place now. Glad I made it home. Road closures everywhere. Link to comment Share on other sites More sharing options...
RitualOfTheTrout Posted July 29, 2017 Share Posted July 29, 2017 7 minutes ago, blackngoldrules said: Flooding all over the place now. Glad I made it home. Road closures everywhere. Not surprising, I am at a pretty high elevation relatively speaking, so no concern for flooding in my immediate area and very thankful for that, but even my backyard is starting to pool water. Check out the radar returns: Link to comment Share on other sites More sharing options...
blackngoldrules Posted July 29, 2017 Share Posted July 29, 2017 Link to comment Share on other sites More sharing options...
CoraopolisWx Posted July 29, 2017 Share Posted July 29, 2017 57 minutes ago, RitualOfTheTrout said: Just looking at this storm on radar one would think it was a Winter Storm... Intense rainfall right now, we finally get in on a good deform band... but its July lol. Even NWS was making comparisons to winter storm look in a previous discussion: Some guy on twitter was showing the position of the 850mb low over W. MD/E. WV That's usually our sweetspot for deform bands. Could've used this setup in Jan 2016, and March 2017. smh 55 minutes ago, blackngoldrules said: Flooding all over the place now. Glad I made it home. Road closures everywhere. Yeah, coming home I took a chance going down 88 to 51 around 9pm. Luckily I got through before they closed that intersection. Link to comment Share on other sites More sharing options...
blackngoldrules Posted July 29, 2017 Share Posted July 29, 2017 Flash Flood Warning Flash Flood Warning PAC003-291030- /O.EXT.KPBZ.FF.W.0066.000000T0000Z-170729T1030Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ BULLETIN - EAS ACTIVATION REQUESTED Flash Flood Warning National Weather Service Pittsburgh PA 107 AM EDT SAT JUL 29 2017 The National Weather Service in Pittsburgh has extended the * Flash Flood Warning for... Southeastern Allegheny County in southwestern Pennsylvania... * Until 630 AM EDT. * At 106 AM EDT, law enforcement officials reported flash flooding in the warned area with multiple road closures and water rescues ongoing. FLASH FLOODING... Occurring. ESTIMATED RAINFALL... Up to 3 inches. ADDITIONAL RAINFALL...Up to 1 inch. * Some locations that may experience flooding include... Pittsburgh... Penn Hills... Mount Lebanon... Bethel Park... Monroeville... McKeesport... Gastonville... Plum... West Mifflin... Baldwin... Upper St. Clair... Murrysville... This includes the following highways... Pennsylvania Turnpike between mile markers 53 and 58. Interstate 79 in Pennsylvania between mile markers 22 and 24. PRECAUTIONARY/PREPAREDNESS ACTIONS... Turn around, don`t drown. Most flood fatalities occur in vehicles. Be especially cautious at night, when it is harder to recognize the dangers of flooding. Runoff from heavy rainfall will flood small streams, poor-drainage areas and low-lying spots. Please report flooding by calling 412-262-1988, posting to the NWS Pittsburgh Facebook page, or using Twitter @NWSPITTSBURGH. && LAT...LON 4039 7975 4039 7977 4036 7977 4027 7999 4033 8017 4053 7970 4043 7970 $$ Fries Link to comment Share on other sites More sharing options...
ChalkHillSnowNut Posted July 29, 2017 Share Posted July 29, 2017 11 hours ago, CoraopolisWx said: Some guy on twitter was showing the position of the 850mb low over W. MD/E. WV That's usually our sweetspot for deform bands. Could've used this setup in Jan 2016, and March 2017. smh Yeah, coming home I took a chance going down 88 to 51 around 9pm. Luckily I got through before they closed that intersection. Yea, we had major flooding up here yesterday afternoon-this summer has been a constant moisture flow-Im sure the pattern will change and it will be bone dry come December....lol Link to comment Share on other sites More sharing options...
CoraopolisWx Posted July 29, 2017 Share Posted July 29, 2017 2 hours ago, ChalkHillSnowNut said: Yea, we had major flooding up here yesterday afternoon-this summer has been a constant moisture flow-Im sure the pattern will change and it will be bone dry come December....lol Unfortunately, all we can do anymore is expect the worst, and hope for something decent. Mabey this year you'll get some better upslope, and really cash in on your elevation. Link to comment Share on other sites More sharing options...
Mailman Posted August 4, 2017 Share Posted August 4, 2017 Mesoscale Discussion 1442 NWS Storm Prediction Center Norman OK 1038 AM CDT Fri Aug 04 2017 Areas affected...Much of the upper Ohio Valley Concerning...Severe potential...Watch possible Valid 041538Z - 041745Z Probability of Watch Issuance...40 percent SUMMARY...Severe hail/wind risk with increasing thunderstorm development may remain somewhat localized and/or sparse in coverage through early to mid afternoon. However, potential does exist for a slow increase in coverage and organization which could be accompanied by a more substantive risk for damaging wind gusts later this afternoon. Trends will continue to be monitored for the possibility of a watch. DISCUSSION...Weak to moderate pre-cold frontal destabilization is now underway across much of the upper Ohio Valley, primarily as insolation contributes to warming of a seasonably moist boundary layer. Latest objective analysis suggests that inhibition is already becoming increasingly negligible, particularly within a corridor ahead of the front, from parts of north central Kentucky through the Lake Erie area. Aided by large-scale ascent ahead of a significant short wave trough now pivoting eastward toward the lower Great Lakes/upper Ohio Valley region, a general increase in thunderstorm activity appears likely through 17-20Z. Further daytime heating may yield CAPE as high as 1500-2000 J/kg, supportive of vigorous updrafts. However, warm sector southwesterly deep layer mean flow, even with some strengthening, appears likely to remain on the order of 30-35 kt. And models indicate that the mid-level cold core of the approaching system will lag to the west. Still, weak cooling aloft may be enough to support some risk for marginally severe hail in initial stronger pulsing activity. Vertical shear and instability may become marginally sufficient to support a gradual increase in convective organization, which may eventually be accompanied by an increasing risk for potentially damaging wind gusts. This probably will take some time through, with any severe hail/wind risk expected to initially remain fairly sparse in coverage. ..Kerr/Goss.. 08/04/2017 Link to comment Share on other sites More sharing options...
Mailman Posted August 4, 2017 Share Posted August 4, 2017 WATCH COUNTY NOTIFICATION FOR WATCH 439 NATIONAL WEATHER SERVICE PITTSBURGH PA 125 PM EDT FRI AUG 4 2017 MDC023-OHC013-019-029-031-059-067-081-111-119-121-157-PAC003-005- 007-019-031-051-053-059-063-065-073-085-121-125-129-WVC009-029- 049-051-061-069-077-103-050100- /O.NEW.KPBZ.SV.A.0439.170804T1725Z-170805T0100Z/ THE NATIONAL WEATHER SERVICE HAS ISSUED SEVERE THUNDERSTORM WATCH 439 IN EFFECT UNTIL 9 PM EDT THIS EVENING FOR THE FOLLOWING AREAS IN MARYLAND THIS WATCH INCLUDES 1 COUNTY IN WESTERN MARYLAND GARRETT IN OHIO THIS WATCH INCLUDES 11 COUNTIES IN EAST CENTRAL OHIO BELMONT CARROLL COLUMBIANA COSHOCTON GUERNSEY HARRISON JEFFERSON MONROE MUSKINGUM NOBLE TUSCARAWAS IN PENNSYLVANIA THIS WATCH INCLUDES 15 COUNTIES IN NORTHWEST PENNSYLVANIA FOREST MERCER VENANGO IN SOUTHWEST PENNSYLVANIA ALLEGHENY FAYETTE GREENE WASHINGTON WESTMORELAND IN WEST CENTRAL PENNSYLVANIA ARMSTRONG BUTLER CLARION INDIANA JEFFERSON IN WESTERN PENNSYLVANIA BEAVER LAWRENCE IN WEST VIRGINIA THIS WATCH INCLUDES 8 COUNTIES IN NORTHEAST WEST VIRGINIA PRESTON IN NORTHERN WEST VIRGINIA MARION MONONGALIA WETZEL IN NORTHERN PANHANDLE OF WEST VIRGINIA BROOKE HANCOCK MARSHALL OHIO THIS INCLUDES THE CITIES OF ALIQUIPPA, AMBRIDGE, BEAVER FALLS, BROOKVILLE, BUTLER, CADIZ, CALDWELL, CAMBRIDGE, CANONSBURG, CARROLLTON, CLARION, COLUMBIANA, CONNELLSVILLE, COSHOCTON, DOVER, EAST LIVERPOOL, ELLWOOD CITY, FAIRMONT, FOLLANSBEE, FORD CITY, FRANKLIN, GRANTSVILLE, GREENSBURG, GROVE CITY, HERMITAGE, INDIANA, KINGWOOD, KITTANNING, LATROBE, MARTINS FERRY, MASONTOWN, MONACA, MORGANTOWN, MOUNDSVILLE, MOUNTAIN LAKE PARK, MURRYSVILLE, NEW CASTLE, NEW KENSINGTON, NEW MARTINSVILLE, NEW PHILADELPHIA, OAKLAND MD, OIL CITY, PITTSBURGH METRO AREA, PUNXSUTAWNEY, SALEM, SHARON, ST. CLAIRSVILLE, STEUBENVILLE, TERRA ALTA, TIONESTA, UNIONTOWN, WASHINGTON, WAYNESBURG, WEIRTON, WELLSBURG, WHEELING, WOODSFIELD, AND ZANESVILLE. $$ Link to comment Share on other sites More sharing options...
meatwad Posted August 4, 2017 Share Posted August 4, 2017 Severe Thunderstorm Warning Severe Thunderstorm Warning OHC029-PAC003-007-019-125-WVC009-029-041845- /O.NEW.KPBZ.SV.W.0152.170804T1801Z-170804T1845Z/ BULLETIN - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Warning National Weather Service Pittsburgh PA 201 PM EDT FRI AUG 4 2017 The National Weather Service in Pittsburgh has issued a * Severe Thunderstorm Warning for... Southeastern Columbiana County in east central Ohio... Western Washington County in southwestern Pennsylvania... Beaver County in western Pennsylvania... Southwestern Butler County in west central Pennsylvania... Western Allegheny County in southwestern Pennsylvania... Northeastern Brooke County in northern West Virginia... Eastern Hancock County in northern West Virginia... * Until 245 PM EDT. * At 201 PM EDT, severe thunderstorms were located along a line extending from Follansbee to near Avella to 6 miles south of East Washington, moving north at 45 mph. HAZARD...60 mph wind gusts. SOURCE...Radar. IMPACT...Damage to trees and power lines. * Locations impacted include... Pittsburgh... Mount Lebanon... Bethel Park... Ross Township... McCandless Township... Moon Township... McMurray... Weirton... Washington... Franklin Park... East Liverpool... Aliquippa... This includes the following highways... Interstate 70 in Pennsylvania between mile markers 12 and 27. Interstate 79 in Pennsylvania between mile markers 22 and 47. Interstate 279 in Pennsylvania between mile markers 1 and 13. Interstate 376 in Pennsylvania between mile markers 33 and 73. PRECAUTIONARY/PREPAREDNESS ACTIONS... Move to an interior room on the lowest floor of a building. Please report severe weather by calling 412-262-1988, posting to the NWS Pittsburgh Facebook page, or using Twitter @NWSPITTSBURGH. && LAT...LON 4068 8014 4051 7990 4000 8016 4000 8020 4020 8040 4033 8060 4056 8058 4064 8053 4064 8052 4079 8049 TIME...MOT...LOC 1801Z 201DEG 38KT 4035 8059 4025 8038 4008 8021 HAIL...<.75IN WIND...60MPH $$ Kramar Link to comment Share on other sites More sharing options...
Mailman Posted August 4, 2017 Share Posted August 4, 2017 Mesoscale Discussion 1443 NWS Storm Prediction Center Norman OK 0246 PM CDT Fri Aug 04 2017 Areas affected...Lower Great Lakes/Allegheny Plateau region Concerning...Severe Thunderstorm Watch 439... Valid 041946Z - 042145Z The severe weather threat for Severe Thunderstorm Watch 439 continues. SUMMARY...Small to, perhaps, marginally severe hail and localized/spotty damaging wind gusts will remain possible near thunderstorm activity overspreading the region through early evening. DISCUSSION...Potential for substantive further organization of ongoing pre-cold frontal convective development into the 21-23Z time frame is appearing increasing unlikely, as objective analysis indicates that deep layer vertical shear remains weak across much of the warm sector south and east of Lakes Erie and Ontario. However, mean lower/mid tropospheric wind fields are strengthening to 30-40 kt across western Pennsylvania and much of New York state. And this could continue to augment severe weather potential with thunderstorm activity developing northeastward/eastward across the region through the remainder of the afternoon, primarily associated with localized enhanced downward transfer of momentum within areas of heavier precipitation loading. ..Kerr.. 08/04/2017 Link to comment Share on other sites More sharing options...
KPITSnow Posted August 4, 2017 Author Share Posted August 4, 2017 Looking at the radar, it looks like the second round of storms may split the city/agc Link to comment Share on other sites More sharing options...
meatwad Posted August 19, 2017 Share Posted August 19, 2017 URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 457 NWS Storm Prediction Center Norman OK 245 PM EDT Sat Aug 19 2017 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of East Central Ohio Western and Central Pennsylvania Northern West Virginia Panhandle * Effective this Saturday afternoon and evening from 245 PM until 900 PM EDT. * Primary threats include... Scattered damaging wind gusts to 65 mph possible Scattered large hail events to 1.5 inches in diameter possible SUMMARY...Storms developing over eastern Ohio into northwest Pennsylvania are expected to move eastward with potential to produce damaging wind gusts and occasional large hail. The activity will continue into parts of central Pennsylvania into the early evening hours before weakening after sunset. The severe thunderstorm watch area is approximately along and 50 statute miles north and south of a line from 20 miles west northwest of Zanesville OH to 45 miles east of State College PA. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU7). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A Severe Thunderstorm Watch means conditions are favorable for severe thunderstorms in and close to the watch area. Persons in these areas should be on the lookout for threatening weather conditions and listen for later statements and possible warnings. Severe thunderstorms can and occasionally do produce tornadoes. && AVIATION...A few severe thunderstorms with hail surface and aloft to 1.5 inches. Extreme turbulence and surface wind gusts to 55 knots. A few cumulonimbi with maximum tops to 450. Mean storm motion vector 27030. ...Weiss Link to comment Share on other sites More sharing options...
MikeB_01 Posted August 19, 2017 Share Posted August 19, 2017 7 minutes ago, meatwad said: URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 457 NWS Storm Prediction Center Norman OK 245 PM EDT Sat Aug 19 2017 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of East Central Ohio Western and Central Pennsylvania Northern West Virginia Panhandle * Effective this Saturday afternoon and evening from 245 PM until 900 PM EDT. * Primary threats include... Scattered damaging wind gusts to 65 mph possible Scattered large hail events to 1.5 inches in diameter possible SUMMARY...Storms developing over eastern Ohio into northwest Pennsylvania are expected to move eastward with potential to produce damaging wind gusts and occasional large hail. The activity will continue into parts of central Pennsylvania into the early evening hours before weakening after sunset. The severe thunderstorm watch area is approximately along and 50 statute miles north and south of a line from 20 miles west northwest of Zanesville OH to 45 miles east of State College PA. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU7). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A Severe Thunderstorm Watch means conditions are favorable for severe thunderstorms in and close to the watch area. Persons in these areas should be on the lookout for threatening weather conditions and listen for later statements and possible warnings. Severe thunderstorms can and occasionally do produce tornadoes. && AVIATION...A few severe thunderstorms with hail surface and aloft to 1.5 inches. Extreme turbulence and surface wind gusts to 55 knots. A few cumulonimbi with maximum tops to 450. Mean storm motion vector 27030. ...Weiss Looks impressive on GOES-16 Link to comment Share on other sites More sharing options...
meatwad Posted August 19, 2017 Share Posted August 19, 2017 Severe Thunderstorm Warning Severe Weather Statement National Weather Service Pittsburgh PA 443 PM EDT SAT AUG 19 2017 PAC003-125-192100- /O.CON.KPBZ.SV.W.0182.000000T0000Z-170819T2100Z/ Washington PA-Allegheny PA- 443 PM EDT SAT AUG 19 2017 ...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 500 PM EDT FOR CENTRAL WASHINGTON AND SOUTHERN ALLEGHENY COUNTIES... At 442 PM EDT, a severe thunderstorm was located over Cecil-Bishop, or near Canonsburg, moving east at 30 mph. HAZARD...60 mph wind gusts. SOURCE...Radar. IMPACT...Expect damage to trees and power lines, resulting in some power outages. Locations impacted include... Pittsburgh... Mount Lebanon... Bethel Park... McMurray... McKeesport... Canonsburg... Gastonville... West Mifflin... Baldwin... Upper St. Clair... Scott Township... Whitehall... This includes Interstate 79 in Pennsylvania between mile markers 22 and 30. PRECAUTIONARY/PREPAREDNESS ACTIONS... Move to an interior room on the lowest floor of a building. Please report severe weather by calling 412-262-1988, posting to the NWS Pittsburgh Facebook page, or using Twitter @NWSPITTSBURGH. && LAT...LON 4028 8035 4036 8031 4043 8020 4040 7984 4014 7993 TIME...MOT...LOC 2042Z 283DEG 24KT 4033 8019 HAIL...<.75IN WIND...60MPH $$ Fries Link to comment Share on other sites More sharing options...
olafminesaw Posted August 21, 2017 Share Posted August 21, 2017 That was about as isolated as a downpour can get. Just about as heavy as the severe storm on Saturday. Would be kind of cool to get that during part of the eclipse, to make it that much darker. Link to comment Share on other sites More sharing options...
blackngoldrules Posted August 21, 2017 Share Posted August 21, 2017 That was about as isolated as a downpour can get. Just about as heavy as the severe storm on Saturday. Would be kind of cool to get that during part of the eclipse, to make it that much darker. I'm just hoping there aren't any clouds around when it happens today. I'm actually off work today, so I might take a ride down to the Science Center in a little while to check it out. I can't find glasses anywhere now so that would be my only option at this point. Getting the downpour here right now, btw. Sent from my SM-G920P using Tapatalk Link to comment Share on other sites More sharing options...
MikeB_01 Posted August 22, 2017 Share Posted August 22, 2017 Interesting set up today. Could really get rocking by 4 pmSPC AC 221228 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0728 AM CDT Tue Aug 22 2017 Valid 221300Z - 231200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS MAINLY THIS AFTERNOON FROM EASTERN OH AND PA ACROSS NY... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS SURROUNDING THE ENHANCED RISK AREA...FROM KY TO WESTERN NEW ENGLAND... ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM TN TO OK AND THE TX PANHANDLE... ...SUMMARY... Severe thunderstorms with damaging winds, and possibly a couple of tornadoes, are expected this afternoon from the upper Ohio Valley to Pennsylvania and New York. Thunderstorms with isolated strong/damaging gusts will also be possible farther southwest into parts of the southern Plains. ...NY/PA to the southern Plains through late evening... A pronounced midlevel trough over the upper Great Lakes will continue to amplify while approaching Quebec tonight. Associated surface cyclogenesis preceding the midlevel trough will drive a surface cold front southeastward across the lower Great Lakes and OH Valley by tonight. In addition, the remnants of a subtropical speed max, enhanced by overnight convection across IL/MO, will accelerate east-northeastward over the OH Valley/PA/NY in advance of the primary midlevel trough, and in phase with the diurnal heating cycle. It appears that the primary focus for thunderstorm development today will a pre-frontal or the remnant outflow/differential heating zone on the leading edge of the ongoing convection from IN to MO. Convection will likely strengthen/redevelop by midday or early afternoon across OH and western NY, and storms will subsequently spread eastward across PA/NY through the afternoon. Midlevel flow and effective bulk shear will likewise strengthen into the 40-50 kt range from OH to PA/NY this afternoon, as surface heating results in steepening low-level lapse rates and MLCAPE near 1500 J/kg. The primary convective evolution should a mixed mode transitioning to line segments, with the potential for downward momentum transfer and swaths of damaging winds with the more intense bowing segments. Additionally, there will be a coincident increase in low-level shear/hodograph curvature across PA/NY during the afternoon in response to the cyclogenesis to the north. Given the relatively moist environment, semi-discrete storms could pose a tornado threat, along with embedded QLCS mesovortices. The large hail threat should remain marginal as a result of modest midlevel lapse rates. Deep-layer flow and shear will weaken with southward extent from KY into TN, and the weak-shear environment will extend westward along the surface cold front in the vicinity of I-40 in OK/TX this afternoon. Loosely organized multicell clusters are expected along the front from TN across AR into OK/TX Panhandle, where isolated downbursts will be the main threat this afternoon/evening. ..Thompson/Smith.. 08/22/2017Sent from my iPhone using Tapatalk Link to comment Share on other sites More sharing options...
Mailman Posted August 22, 2017 Share Posted August 22, 2017 [img Mesoscale Discussion 1547 NWS Storm Prediction Center Norman OK 1054 AM CDT Tue Aug 22 2017 Areas affected...Western PA...Southeast OH...Western WV...Northern KY... Concerning...Severe potential...Severe Thunderstorm Watch likely Valid 221554Z - 221700Z Probability of Watch Issuance...80 percent SUMMARY...Severe thunderstorm watch will likely be issued by 17z across portions of the Ohio Valley. DISCUSSION...Pre-frontal boundary-layer cumulus field is expanding/deepening across the OH Valley as surface temperatures warm into the lower 80s. While mid-level lapse rates are poor due to high PW air mass, surface-3km lapse rates have steepened enough for surface parcels to reach their LFC. Lightning is beginning to increase with maturing convection from the northwest portions of PA, southwest along the OH River into southern IN. This activity should gradually increase in areal coverage within a sheared environment favorable for organized line segments and clusters. A considerable amount of convection is expected along this corridor within a few hours and locally damaging winds can be expected with these storms. Severe thunderstorm watch is warranted for this evolving threat. ..Darrow/Grams.. 08/22/2017 Link to comment Share on other sites More sharing options...
meatwad Posted August 22, 2017 Share Posted August 22, 2017 URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 462 NWS Storm Prediction Center Norman OK 1240 PM EDT Tue Aug 22 2017 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Far southern Indiana Central and northern Kentucky Far western Maryland Panhandle Southern and eastern Ohio Western and central Pennsylvania Northern and western West Virginia * Effective this Tuesday afternoon and evening from 1240 PM until 900 PM EDT. * Primary threats include... Scattered damaging wind gusts to 70 mph likely A tornado or two possible SUMMARY...Scattered damaging winds appear likely as numerous clusters and lines of storms intensify and move east this afternoon. The severe thunderstorm watch area is approximately along and 105 statute miles east and west of a line from 15 miles northeast of Dubois PA to 60 miles south southeast of Louisville KY. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU2). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A Severe Thunderstorm Watch means conditions are favorable for severe thunderstorms in and close to the watch area. Persons in these areas should be on the lookout for threatening weather conditions and listen for later statements and possible warnings. Severe thunderstorms can and occasionally do produce tornadoes. && OTHER WATCH INFORMATION...CONTINUE...WW 461... AVIATION...A few severe thunderstorms with hail surface and aloft to 1.5 inches. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 26025. ...Grams Top of Page/All Current Watches/Forecast Products/Home Link to comment Share on other sites More sharing options...
Mailman Posted August 22, 2017 Share Posted August 22, 2017 BULLETIN - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Warning National Weather Service Pittsburgh PA 120 PM EDT TUE AUG 22 2017 The National Weather Service in Pittsburgh has issued a * Severe Thunderstorm Warning for... Northwestern Washington County in southwestern Pennsylvania... Central Allegheny County in southwestern Pennsylvania... * Until 200 PM EDT. * At 119 PM EDT, a severe thunderstorm was located near Avella, moving east at 40 mph. HAZARD...60 mph wind gusts. SOURCE...Radar. IMPACT...Damage to trees and power lines. * Locations impacted include... Pittsburgh... Penn Hills... Mount Lebanon... Bethel Park... Ross Township... McMurray... McKeesport... Canonsburg... Avella... Shaler Township... West Mifflin... North Side Pittsburgh... This includes the following highways... Interstate 79 in Pennsylvania between mile markers 22 and 35. Interstate 279 in Pennsylvania between mile markers 1 and 7. Interstate 376 in Pennsylvania between mile markers 57 and 77. PRECAUTIONARY/PREPAREDNESS ACTIONS... Move to an interior room on the lowest floor of a building. Please report severe weather by calling 412-262-1988, posting to the NWS Pittsburgh Facebook page, or using Twitter @NWSPITTSBURGH. Link to comment Share on other sites More sharing options...
north pgh Posted August 22, 2017 Share Posted August 22, 2017 Anyone notice the Warned cell over Southern Allegheny County looks like it may be getting a little hook on the bottom of the storm? Link to comment Share on other sites More sharing options...
MikeB_01 Posted August 22, 2017 Share Posted August 22, 2017 Just now, north pgh said: Anyone notice the Warned cell over Southern Allegheny County looks like it may be getting a little hook on the bottom of the storm? The velocities are relatively tight as well Link to comment Share on other sites More sharing options...
north pgh Posted August 22, 2017 Share Posted August 22, 2017 2 minutes ago, MikeB_01 said: The velocities are relatively tight as well Keep an eye on this. NWS could upgrade to Tornado Warning Tail looks to be heading into Bethel Park area. Link to comment Share on other sites More sharing options...
MikeB_01 Posted August 22, 2017 Share Posted August 22, 2017 3 minutes ago, north pgh said: Keep an eye on this. NWS could upgrade to Tornado Warning Velocities weakening but it is really coming down in Lebo. No hail yet, but wont be surprised. The lightning and thunder is absolutely breathtaking. Link to comment Share on other sites More sharing options...
MikeB_01 Posted August 22, 2017 Share Posted August 22, 2017 Actually had some half in hail here. Biggest ive ever seen in person. Anyone else getting anything? Link to comment Share on other sites More sharing options...
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