Vice-Regent Posted June 26, 2021 Share Posted June 26, 2021 Historically significant period coming up for Severe wx in this region. I can sniff out the big ones. 2 Link to comment Share on other sites More sharing options...
Kmlwx Posted June 28, 2021 Author Share Posted June 28, 2021 June 4, 2008 has been showing up in some of the analogs around the 96hr mark. 1 Link to comment Share on other sites More sharing options...
Kmlwx Posted June 28, 2021 Author Share Posted June 28, 2021 Late in the 6z GFS run the model tries to send down a bunch of great mid-level lapse rates but they go from north to south well to our west. But something to keep an eye on if the flow is different as we get closer. Link to comment Share on other sites More sharing options...
high risk Posted June 29, 2021 Share Posted June 29, 2021 Looks to me like Thursday afternoon has a good chance to eventually become a SLGT. Lapse rates aren't great, but the timing looks favorable, and the shear/instability combo as current progged would likely generate SVR. Expecting a very heavy rain threat too, particularly as additional rounds of convection move over the area after dark. 1 Link to comment Share on other sites More sharing options...
Kmlwx Posted June 30, 2021 Author Share Posted June 30, 2021 Heck of a 12z NAM nest run for the close-in metro area - Blows up a huge cell or line segment - good UH swath and sim IR frames 3 Link to comment Share on other sites More sharing options...
SnowenOutThere Posted June 30, 2021 Share Posted June 30, 2021 1 hour ago, Kmlwx said: Heck of a 12z NAM nest run for the close-in metro area - Blows up a huge cell or line segment - good UH swath and sim IR frames Thanks to my experience in snow forecasting I know that this is the only model that will be correct and I should cling to it no matter what the other ones say, ITS NEVER GONE WRONG BEFORE*. *Citation Needed 1 Link to comment Share on other sites More sharing options...
high risk Posted June 30, 2021 Share Posted June 30, 2021 1 hour ago, Kmlwx said: Heck of a 12z NAM nest run for the close-in metro area - Blows up a huge cell or line segment - good UH swath and sim IR frames yeah, even if we don't focus on potential significant UH swaths, the signal for widespread, organized convection in the early/mid afternoon hours tomorrow is robust across the CAMs. The shear/instability profile combo should be sufficient for some of that to become severe. The only "concern" is weak lapse rates shown in several models, but I like our chances of being upgraded to SLGT in the new day 2 outlook. 2 Link to comment Share on other sites More sharing options...
Kmlwx Posted June 30, 2021 Author Share Posted June 30, 2021 Here's a little sample from over on Pivotal - la la lock it up 1 1 Link to comment Share on other sites More sharing options...
Stormfly Posted June 30, 2021 Share Posted June 30, 2021 LOL that's probably spot on as it has us getting nary a drop! Link to comment Share on other sites More sharing options...
Kmlwx Posted June 30, 2021 Author Share Posted June 30, 2021 Looks like it's going to be a slight risk for tomorrow as of the 1730z outlook. Text/discussion is already out. 1 Link to comment Share on other sites More sharing options...
Kmlwx Posted June 30, 2021 Author Share Posted June 30, 2021 The slight is along and then south and east of the metro areas. Western areas marginal. Link to comment Share on other sites More sharing options...
Kmlwx Posted June 30, 2021 Author Share Posted June 30, 2021 The HRDPS is also pretty similar to that 12z NAM nest run. I'm in for tomorrow. There's a decent amount of guidance supporting the idea. 1 Link to comment Share on other sites More sharing options...
Kmlwx Posted June 30, 2021 Author Share Posted June 30, 2021 The 12z GFS in fantasy land (post 300hrs) dumps a sizeable EML into our area. That would be a game changer. It wasn't on the 0z or 6z, though - so it's probably going poof by next run. And even on this run, it focuses any threat well north and west of us. Link to comment Share on other sites More sharing options...
yoda Posted June 30, 2021 Share Posted June 30, 2021 @Kmlwx @high risk @Eskimo Joe Watch up for parts of MD and NW VA till 10pm Link to comment Share on other sites More sharing options...
yoda Posted June 30, 2021 Share Posted June 30, 2021 3 minutes ago, yoda said: @Kmlwx @high risk @Eskimo Joe Watch up for parts of MD and NW VA till 10pm BULLETIN - IMMEDIATE BROADCAST REQUESTED SEVERE THUNDERSTORM WATCH OUTLINE UPDATE FOR WS 330...RESENT NWS STORM PREDICTION CENTER NORMAN OK 445 PM EDT WED JUN 30 2021 SEVERE THUNDERSTORM WATCH 330 IS IN EFFECT UNTIL 1000 PM EDT FOR THE FOLLOWING LOCATIONS MDC001-013-021-043-010200- /O.NEW.KWNS.SV.A.0330.210630T2045Z-210701T0200Z/ MD . MARYLAND COUNTIES INCLUDED ARE ALLEGANY CARROLL FREDERICK WASHINGTON PAC001-041-043-055-071-075-099-107-133-010200- /O.NEW.KWNS.SV.A.0330.210630T2045Z-210701T0200Z/ PA . PENNSYLVANIA COUNTIES INCLUDED ARE ADAMS CUMBERLAND DAUPHIN FRANKLIN LANCASTER LEBANON PERRY SCHUYLKILL YORK VAC043-069-840-010200- /O.NEW.KWNS.SV.A.0330.210630T2045Z-210701T0200Z/ VA . VIRGINIA COUNTIES INCLUDED ARE CLARKE FREDERICK VIRGINIA INDEPENDENT CITIES INCLUDED ARE WINCHESTER WVC003-027-037-057-065-010200- /O.NEW.KWNS.SV.A.0330.210630T2045Z-210701T0200Z/ WV . WEST VIRGINIA COUNTIES INCLUDED ARE BERKELEY HAMPSHIRE JEFFERSON MINERAL MORGAN ATTN...WFO...LWX...CTP... 1 Link to comment Share on other sites More sharing options...
high risk Posted June 30, 2021 Share Posted June 30, 2021 14 minutes ago, yoda said: @Kmlwx @high risk @Eskimo Joe Watch up for parts of MD and NW VA till 10pm It's worth watching, but by the time it gets here, we will be losing instability (although we'll still have a decent amount of CAPE to work with), and the shear is not nearly as good here as it is further northwest. Heck, the shear isn't even very good where the watch just got issued. If, however, a sfc cold pool can become established, the line can organize better. and we would have some modest severe potential in a few hours. The HRRR runs haven't been too excited, but the 18z NAM nest looks robust. 1 Link to comment Share on other sites More sharing options...
Kmlwx Posted June 30, 2021 Author Share Posted June 30, 2021 If nothing else I'd love to get the outflow through here tonight. Been getting pretty brutal in my bedroom (removed my window A/C this year because in past summers I was getting wasps and bugs through the non-airtight foam seals). Link to comment Share on other sites More sharing options...
weatherCCB Posted June 30, 2021 Share Posted June 30, 2021 Outflow coming thru now. Hoping for some rain. radar looks promising Link to comment Share on other sites More sharing options...
Kmlwx Posted June 30, 2021 Author Share Posted June 30, 2021 One of the best defined outflow boundaries I've seen on radar this year. Link to comment Share on other sites More sharing options...
weatherCCB Posted June 30, 2021 Share Posted June 30, 2021 Looks like storms r going to fire behind this boundary Link to comment Share on other sites More sharing options...
Kmlwx Posted June 30, 2021 Author Share Posted June 30, 2021 5 minutes ago, weatherCCB said: Looks like storms r going to fire behind this boundary They will probably be sub-severe, though. Boundary just went through here. Link to comment Share on other sites More sharing options...
weatherCCB Posted June 30, 2021 Share Posted June 30, 2021 Just now, Kmlwx said: They will probably be sub-severe, though. Boundary just went through here. Yeah,, but just want some rain. Tomorrow has some decent potential. Link to comment Share on other sites More sharing options...
NorthArlington101 Posted June 30, 2021 Share Posted June 30, 2021 bye bye B-meet 6 Link to comment Share on other sites More sharing options...
CAPE Posted July 1, 2021 Share Posted July 1, 2021 Slight risk for I-95 east and southward. ...Mid Atlantic... Mid/upper flow and deep-layer shear along the axis of stronger destabilization within the surface troughing may be fairly modest to weak, at least initially. However, strengthening of southwesterly winds to 30-40 kt in the 850-700 mb layer may be sufficient to contribute to one or two organizing clusters of storms by late this afternoon. Given the magnitude of the forecast CAPE, coupled with relatively steep low-level lapse rates, it appears that the environment will be conducive to potentially damaging surface gusts. This may be associated with locally strong downbursts initially, then with strengthening cold pools in upscale growing, northeastward and eastward propagating convection into this evening. I just want a dose of heavy rain, and maybe get a shot of a shelf to add to my collection. Link to comment Share on other sites More sharing options...
mappy Posted July 1, 2021 Share Posted July 1, 2021 that gust front was money last night during softball -- finished up before the broken line came in. some rumbles of thunder, brief heavy rain then was done 2 Link to comment Share on other sites More sharing options...
Eskimo Joe Posted July 1, 2021 Share Posted July 1, 2021 15 hours ago, yoda said: @Kmlwx @high risk @Eskimo Joe Watch up for parts of MD and NW VA till 10pm I'm in Chincoteague until Saturday evening. Hope we see a waterspout today or something. Link to comment Share on other sites More sharing options...
Stormfly Posted July 1, 2021 Share Posted July 1, 2021 Slight risk now... Link to comment Share on other sites More sharing options...
CAPE Posted July 1, 2021 Share Posted July 1, 2021 Mesoscale Discussion 1139 NWS Storm Prediction Center Norman OK 1045 AM CDT Thu Jul 01 2021 Areas affected...Portions of far eastern WV...northern/central VA...DC...MD...DE...southeastern PA...and central/southern NJ Concerning...Severe potential...Severe Thunderstorm Watch likely Valid 011545Z - 011745Z Probability of Watch Issuance...80 percent SUMMARY...The threat for scattered damaging wind gusts is expected to increase this afternoon, and one or more Severe Thunderstorm Watches will likely be needed. DISCUSSION...Mid-level west-southwesterly flow over the Mid-Atlantic associated with an upper trough/low across Ontario, Quebec, and the Great Lakes is not as strong today compared to yesterday. Still, about 25-40 kt is present generally around 3-6 km AGL based on recent VWP estimates from area radars. An area of precipitation with embedded isolated lightning flashes extends from northeastern MD into eastern PA as of 1545Z. There is concern that this precipitation and its associated widespread cloudiness may tend to limit destabilization and steepening of low-level lapse rates early this afternoon, particularly across eastern PA into NJ and vicinity. Still, there will probably be some clearing behind this initial activity, as evidenced by recent cloud breaks across parts of south-central PA. Better prospects for robust boundary-layer destabilization this afternoon will likely be realized across parts of northern/central VA into MD and the Delmarva Peninsula where clouds are less prevalent. Even though mid-level lapse rates will remain poor, around 1500-2000 J/kg of MLCAPE should develop this afternoon across this region through diurnal heating of a moist low-level airmass. Weaker destabilization, with MLCAPE generally ranging from 500-1500 J/kg, will probably develop farther north into eastern PA and NJ owing to the influence of the ongoing precipitation. Storms will probably increase in coverage over the next couple of hours along/east of the Blue Ridge Mountains and into south-central PA as a weak/decaying MCV moves eastward from WV. 30-40 kt of effective bulk shear will likely foster some storm organization, with multiple clusters likely moving eastward through the afternoon. The greatest threat for scattered damaging wind gusts should develop where heating of the boundary layer can steepen low-level lapse rates and encourage efficient downdraft accelerations. 1 Link to comment Share on other sites More sharing options...
Newman Posted July 1, 2021 Share Posted July 1, 2021 1 Link to comment Share on other sites More sharing options...
mappy Posted July 1, 2021 Share Posted July 1, 2021 watch for all 1 Link to comment Share on other sites More sharing options...
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