psuhoffman Posted July 25, 2017 Share Posted July 25, 2017 13 hours ago, yoda said: Better send those pics and stuff to LWX... LWX made no mention of rotation in their warnings I'll send it to them today when I get a chance. I notice there was no mention from lwx but there was definitely rotation and a clear well formed wall cloud and even seemed to be a bit of a funnel cloud for a short time. It passed right over me and things got wild for a short time. It definitely had the same feel as other close encounters I've had when chasing but this was the first time it was at my house. Didn't come close to touching down but no doubt it had rotation. It kind of caught me off guard. I was just thinking it was a typical thunderstorm and went out to get the umbrella down on my pool deck when the wind picked up and suddenly realized what was going on and was in the middle of it as it passed over. Link to comment Share on other sites More sharing options...
Kmlwx Posted July 25, 2017 Share Posted July 25, 2017 Timing for Thursday PM seems to be a bit of an issue. Seems like the overnight period is favored. But if Kent Island can get an EF-2 in the early morning hours...anything is possible. Maybe this is the year of nocturnal wedges. Link to comment Share on other sites More sharing options...
Kmlwx Posted July 25, 2017 Share Posted July 25, 2017 CIPS doesn't have much either. But again...we'll see how it looks as we close. Link to comment Share on other sites More sharing options...
yoda Posted July 25, 2017 Share Posted July 25, 2017 12z 3km NAM looks decent at the end of its run re radar Link to comment Share on other sites More sharing options...
psuhoffman Posted July 25, 2017 Share Posted July 25, 2017 21 hours ago, yoda said: Better send those pics and stuff to LWX... LWX made no mention of rotation in their warnings I did send in the photos and this was the reply from NWS. They got back very quickly btw. "Good (late) afternoon, Thank you for the phone call and the pictures! We were watching this as it crossed out of Pennsylvania and had noted some weak rotation on the FAA Terminal Doppler Radar for BWI, and were wondering if there was visible rotation. It definitely organized on a storm scale, but not quite strong enough in the lowest levels to produce a tornado. A Severe Thunderstorm Warning was issued a short time later for points further east for straight line winds, which knocked down a fair number of trees (we heard of about a dozen or so) in Harford County." Link to comment Share on other sites More sharing options...
Kmlwx Posted July 25, 2017 Share Posted July 25, 2017 18z NAM and 3km NAM look pretty unimpressive. Link to comment Share on other sites More sharing options...
high risk Posted July 26, 2017 Share Posted July 26, 2017 11 hours ago, mappy said: Put the Bay City/Stevensville Tornado path on a map. Survey is still considered preliminary, but can be found here: https://nwschat.weather.gov/p.php?pid=201707242221-KPHI-NOUS41-PNSPHI This is fantastic. I crossed Kent Island today on my way to the beach, and it's very obvious where the tornado crossed Rt 50, with sheared-off trees on both sides of the road. Link to comment Share on other sites More sharing options...
mappy Posted July 26, 2017 Author Share Posted July 26, 2017 Thanks, @high risk! Link to comment Share on other sites More sharing options...
AmericanWxFreak Posted July 26, 2017 Share Posted July 26, 2017 They yanked the slight risk completely lol Link to comment Share on other sites More sharing options...
Kmlwx Posted July 26, 2017 Share Posted July 26, 2017 23 minutes ago, AmericanWxFreak said: They yanked the slight risk completely lol I would agree. I don't see any guidance that looks particularly robust with regards to a severe threat. Even the heavy rain threat seems a bit north on latest guidance IMO. Link to comment Share on other sites More sharing options...
BTRWx Posted July 27, 2017 Share Posted July 27, 2017 8 hours ago, Kmlwx said: I would agree. I don't see any guidance that looks particularly robust with regards to a severe threat. Even the heavy rain threat seems a bit north on latest guidance IMO. Check with the King...anyone have ec qpf output? https://s4.postimg.org/oh6z3s4ot/ecmwf_z500_mslp_us_4_July_Noreaster.png Link to comment Share on other sites More sharing options...
yoda Posted July 27, 2017 Share Posted July 27, 2017 1 minute ago, BTRWx said: Check with the King...anyone have ec qpf output? https://s4.postimg.org/oh6z3s4ot/ecmwf_z500_mslp_us_4_July_Noreaster.png Posted in the July Obs Thread a page ago... Link to comment Share on other sites More sharing options...
BTRWx Posted July 27, 2017 Share Posted July 27, 2017 1 minute ago, yoda said: Posted in the July Obs Thread a page ago... Thanks for that. Why is that discussion in obs exactly?? Link to comment Share on other sites More sharing options...
yoda Posted July 27, 2017 Share Posted July 27, 2017 Just now, BTRWx said: Thanks for that. Why is that discussion in obs exactly?? its heavy rain and not severe weather Link to comment Share on other sites More sharing options...
BTRWx Posted July 27, 2017 Share Posted July 27, 2017 1 minute ago, yoda said: its heavy rain and not severe weather I vote storm thread! Link to comment Share on other sites More sharing options...
Kmlwx Posted July 27, 2017 Share Posted July 27, 2017 Obs thread is probably fine. The amount of places that actually get the ridiculous amounts are probably going to be quite small. Most of us will probably get a good soaker and that's it. Link to comment Share on other sites More sharing options...
yoda Posted August 4, 2017 Share Posted August 4, 2017 So LWX... you say there is a threat on Monday... and the magical T word appears Quote .LONG TERM /MONDAY THROUGH FRIDAY/... A slow moving, moisture laden frontal system will drag through the region early next week. PWATs near 2 inches combined with strong convergence in the midst of low pressure tracking along the slow moving front will likely lead to numerous showers and thunderstorms with heavy rainfall. Upper level divergence aided by a 100+ knot jet streak at 250 mb will help sustain and organize storms, as well. The deep-layer shear could contribute to a severe weather threat depending on instability. There is some uncertainty with the low track Monday which will determine finer scale details such as where the heaviest rain sets up and where severe weather potential (wind/hail/tornadoes) is maximized. The NAM takes the low to the north over PA which would lead to an elevated severe threat but perhaps reduce the widespread heavy/persistent rain potential. The GFS is further south across central VA with a cooler boundary layer and less severe potential for most of the area but a significant heavy rain threat due to strong surface convergence. The ECMWF basically splits the difference, with various ensemble members falling somewhere in between. Link to comment Share on other sites More sharing options...
Kmlwx Posted August 6, 2017 Share Posted August 6, 2017 0z NAM appears to push the front farther north and as a result gets us better parameters Mon PM. Link to comment Share on other sites More sharing options...
Kmlwx Posted August 6, 2017 Share Posted August 6, 2017 6z NAM tapered it back a little again though the 3km brings a nice line through it seems. This event seems to have the typical markings of a day that we can't clear out the clouds and we get nothing except showers and a couple general storms. Link to comment Share on other sites More sharing options...
yoda Posted August 7, 2017 Share Posted August 7, 2017 00z NAM looks decent... BWI at 21z 900 SBCAPE/800 MLCAPE 0-6km shear around 40 kts and large amounts of 0-1 and 0-3km SRH Same at KDCA at 18z and 21z... EZF 18z and 21z... and NHK at 18z and 21z Link to comment Share on other sites More sharing options...
yoda Posted August 7, 2017 Share Posted August 7, 2017 Just SE of DCA at 21z MON Link to comment Share on other sites More sharing options...
yoda Posted August 7, 2017 Share Posted August 7, 2017 00z NAM NEST slams DC south 23z to 01z... shows up on the UD helicity swaths as well Link to comment Share on other sites More sharing options...
high risk Posted August 7, 2017 Share Posted August 7, 2017 9 hours ago, yoda said: 00z NAM NEST slams DC south 23z to 01z... shows up on the UD helicity swaths as well NAM nest still looks interesting, but the 6z cycle moved the location of interest further south. The HRRR keeps the heating zone further south as well, and it now doesn't fire any convection during those evening hours. It seems that areas north of a line from Alexandria to Deale have little SVR threat; areas to the south (and perhaps quite a bit to the south) have a modest chance of SVR perhaps during the main batch of precip during the early afternoon and then a conditional risk if storms fire again in the early evening. Link to comment Share on other sites More sharing options...
George BM Posted August 8, 2017 Share Posted August 8, 2017 On 3/1/2017 at 10:23 AM, yoda said: Any possibility that this has the resemblance of what I think was a late June day a few years ago when a line of storms moved through DC region around 3pm with wind gusts to 80 mph? Or is this a whole different system? I remember LWX issuing STW swaths You're probably thinking about the June 4, 2008 event. A severe MCS came through the region at 60-65 mph bringing widespread wind damage throughout the much of the DMV region. The line in West Virginia certainly resembles that event. The only thing is that there is no where near as much CAPE with 500-1000 J/kg mlcape expected by the afternoon. June 4, 2008 had mlcape of 2000-3000 J/kg with 40-50kt effective shear by the afternoon. However with skies clearing out nicely and 70+kt effective bulk shear ahead of this line, I'm definitely intrigued about today's threat. June 4, 2008: Today: Is what I would have said if I was a member on March 1st at 10:23 AM EST. Link to comment Share on other sites More sharing options...
yoda Posted August 11, 2017 Share Posted August 11, 2017 Mesoscale Discussion 1476 NWS Storm Prediction Center Norman OK 0248 PM CDT Fri Aug 11 2017 Areas affected...portions of central and eastern PA...eastern WV Panhandle...MD...and northern VA Concerning...Severe potential...Watch unlikely Valid 111948Z - 112115Z Probability of Watch Issuance...20 percent SUMMARY...Isolated 45-60 mph gusts and marginally severe hail are possible with the more intense/transient supercell storms this afternoon. A brief/weak tornado cannot be ruled out. DISCUSSION...Radar mosaic over the past hour has shown a blossoming of thunderstorms over central PA into the eastern WV Panhandle. The discussion area resides within a belt of moderately strong west-southwesterly 500-mb flow (40-45 kt) per area WSR-88D VAD data. Surface analysis indicates temperatures have warmed into the upper 70s degrees F over PA and warmer air with temperatures in the lower 80s is located farther south over MD/northern VA. A relatively moisture-rich airmass is in place with upper 60s north and around 70 south. Despite modest low and mid-level lapse rates, around 500 J/kg MLCAPE has developed within a strengthening/veering wind profile with height. A mid-level vorticity maximum is traversing eastward across the southern Great Lakes and approaching the region. As a result, a couple of the stronger updrafts will probably acquire transient supercell structure this afternoon. The primary hazards with this activity will be isolated strong to locally severe gusts capable of wind damage. ..Smith/Guyer.. 08/11/2017 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...PHI...BGM...CTP...LWX...PBZ... Link to comment Share on other sites More sharing options...
yoda Posted August 11, 2017 Share Posted August 11, 2017 BULLETIN - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Warning National Weather Service Baltimore MD/Washington DC 426 PM EDT FRI AUG 11 2017 The National Weather Service in Sterling Virginia has issued a * Severe Thunderstorm Warning for... East central Shenandoah County in northwestern Virginia... Warren County in northwestern Virginia... Northwestern Fauquier County in northern Virginia... North central Rappahannock County in northwestern Virginia... * Until 515 PM EDT * At 425 PM EDT, a severe thunderstorm was located near Strasburg, moving east at 15 mph. HAZARD...60 mph wind gusts. SOURCE...Radar indicated. IMPACT...Damaging winds will cause some trees and large branches to fall. This could injure those outdoors, as well as damage homes and vehicles. Roadways may become blocked by downed trees. Localized power outages are possible. Unsecured light objects may become projectiles. * Locations impacted include... Front Royal, Strasburg, Linden, Chester Gap, Flint Hill, Fort Valley, Huntly, Arco, Howellsville, Seven Fountains, Dilbeck, Riverton, Karo, Glen Echo, Bentonville, Blue Mountain, Browntown, Cedarville, Buckton and Riverside. Link to comment Share on other sites More sharing options...
yoda Posted August 11, 2017 Share Posted August 11, 2017 SPC 2000 OTLK adds 2% TOR for most of LWX CWA Link to comment Share on other sites More sharing options...
yoda Posted August 11, 2017 Share Posted August 11, 2017 BULLETIN - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Warning National Weather Service Baltimore MD/Washington DC 512 PM EDT FRI AUG 11 2017 The National Weather Service in Sterling Virginia has issued a * Severe Thunderstorm Warning for... Central Warren County in northwestern Virginia... Northwestern Fauquier County in northern Virginia... Central Rappahannock County in northwestern Virginia... * Until 600 PM EDT * At 511 PM EDT, a severe thunderstorm was located near Front Royal, moving east at 25 mph. HAZARD...60 mph wind gusts and half dollar size hail. SOURCE...Radar indicated. IMPACT...Damaging winds will cause some trees and large branches to fall. This could injure those outdoors, as well as damage homes and vehicles. Roadways may become blocked by downed trees. Localized power outages are possible. Unsecured light objects may become projectiles. * Locations impacted include... Front Royal, Hume, Delaplane, Linden, Chester Gap, Flint Hill, Washington, Castleton, Huntly, Arco, Hackleys Crossroads, Fourway, Cresthill, Rectortown, Glen Echo, Five Forks, Rock Mills, Markham, Browntown and Ashville. Link to comment Share on other sites More sharing options...
yoda Posted August 11, 2017 Share Posted August 11, 2017 small hook developing in Rappahanock? ETA -- looks like some rotation in Fauquier County when looping the Storm Relative Velocity and Base Velocity -- NW of Warrenton Link to comment Share on other sites More sharing options...
ErinInTheSky Posted August 11, 2017 Share Posted August 11, 2017 The rotation is clear on the storm without using storm rel. Possibly will get warned. Link to comment Share on other sites More sharing options...
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