yoda Posted July 28, 2021 Share Posted July 28, 2021 Mmmmm tasty disco Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1219 PM CDT Wed Jul 28 2021 Valid 291200Z - 301200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE OHIO VALLEY INTO THE MID-ATLANTIC STATES... ...SUMMARY... Thunderstorms associated with wind damage and a risk for a tornado, will be possible from the Ohio Valley, central Appalachians and Mid-Atlantic states on Thursday. ...Ohio Valley/Central Appalachians/Mid-Atlantic/Mid Mississippi Valley... Showers and thunderstorms will likely be ongoing Thursday morning across the southern Great Lakes in association with an MCV. This mid-level feature embedded within northwesterly flow, is expected to result from a severe squall line over the western Great Lakes prior to the start of the period. In the low levels, a surface low initially over the central Great Lakes will develop eastward into New England late Thursday night. An attendant cold front will push southeast across a large part of the OH Valley with the trailing portion of the boundary extending into the central High Plains. Considerable uncertainty remains regarding the evolution of convection from IN into PA through the early afternoon. A myriad of possible scenarios are evident in the latest convection-allowing model guidance in terms of the details of storm redevelopment during the afternoon. With those concerns stated, a moist airmass will extend from the Corn Belt eastward into the Mid-Atlantic states with 60s and lower 70s F dewpoints. Strong heating on the periphery of earlier cloud debris will result in a moderate to very unstable airmass (1000-3000 J/kg MLCAPE). A belt of strong westerly 700-mb flow is forecast to overspread the upper OH Valley into the Mid-Atlantic states during the afternoon. Several linear clusters or a combination of linear clusters and supercells are possible from the OH Valley into the Mid-Atlantic states. Damaging gusts and tornadoes are possible with the more intense thunderstorms. Lower storm coverage and weaker deep-layer shear farther west over IL/MO will likely limit storm organization and the overall risk for severe thunderstorms. 1 Link to comment Share on other sites More sharing options...
Scraff Posted July 28, 2021 Share Posted July 28, 2021 5 hours ago, mattie g said: So...we'll never see those alerts? We need something like that in winter for blizzards too…so we won’t ever see those either. Link to comment Share on other sites More sharing options...
H2O Posted July 28, 2021 Share Posted July 28, 2021 7 minutes ago, Scraff said: We need something like that in winter for blizzards too…so we won’t ever see those either. Fringe alerts and warnings 1 Link to comment Share on other sites More sharing options...
Kmlwx Posted July 28, 2021 Author Share Posted July 28, 2021 Smart money is on us failing tomorrow - but those parameters are beefiest I've seen in a while for us. 1 Link to comment Share on other sites More sharing options...
Eskimo Joe Posted July 28, 2021 Share Posted July 28, 2021 If we don't get blanketed with debris clouds overnight, I could see SPC nudging the northern portion of the LWX CWA up into Central PA to and ENH risk. 1 Link to comment Share on other sites More sharing options...
Kmlwx Posted July 28, 2021 Author Share Posted July 28, 2021 4 minutes ago, Eskimo Joe said: If we don't get blanketed with sebris clouds overnight, I could see SPC nudging the northern portion of the LWX CWA up into Central PA to and ENH risk. Meh - high risk or bust - with PDS watches and a continuous bow encompassing the entire region. Link to comment Share on other sites More sharing options...
mappy Posted July 28, 2021 Share Posted July 28, 2021 6 minutes ago, Kmlwx said: Meh - high risk or bust - with PDS watches and a continuous bow encompassing the entire region. lets not get too greedy. we fail too much to get picky over PDS watches and high risks lol Link to comment Share on other sites More sharing options...
Kmlwx Posted July 28, 2021 Author Share Posted July 28, 2021 6 minutes ago, mappy said: lets not get too greedy. we fail too much to get picky over PDS watches and high risks lol Uber-high risk and super-PDS watches then. I'm very greedy and needy with weather. Though...I'd trade no more severe for the rest of the calendar year for a single 36 inch snowstorm IMBY this winter. Link to comment Share on other sites More sharing options...
mattie g Posted July 28, 2021 Share Posted July 28, 2021 1 hour ago, yoda said: Mmmmm tasty disco Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1219 PM CDT Wed Jul 28 2021 Valid 291200Z - 301200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE OHIO VALLEY INTO THE MID-ATLANTIC STATES... ...SUMMARY... Thunderstorms associated with wind damage and a risk for a tornado, will be possible from the Ohio Valley, central Appalachians and Mid-Atlantic states on Thursday. ...Ohio Valley/Central Appalachians/Mid-Atlantic/Mid Mississippi Valley... Showers and thunderstorms will likely be ongoing Thursday morning across the southern Great Lakes in association with an MCV. This mid-level feature embedded within northwesterly flow, is expected to result from a severe squall line over the western Great Lakes prior to the start of the period. In the low levels, a surface low initially over the central Great Lakes will develop eastward into New England late Thursday night. An attendant cold front will push southeast across a large part of the OH Valley with the trailing portion of the boundary extending into the central High Plains. Considerable uncertainty remains regarding the evolution of convection from IN into PA through the early afternoon. A myriad of possible scenarios are evident in the latest convection-allowing model guidance in terms of the details of storm redevelopment during the afternoon. With those concerns stated, a moist airmass will extend from the Corn Belt eastward into the Mid-Atlantic states with 60s and lower 70s F dewpoints. Strong heating on the periphery of earlier cloud debris will result in a moderate to very unstable airmass (1000-3000 J/kg MLCAPE). A belt of strong westerly 700-mb flow is forecast to overspread the upper OH Valley into the Mid-Atlantic states during the afternoon. Several linear clusters or a combination of linear clusters and supercells are possible from the OH Valley into the Mid-Atlantic states. Damaging gusts and tornadoes are possible with the more intense thunderstorms. Lower storm coverage and weaker deep-layer shear farther west over IL/MO will likely limit storm organization and the overall risk for severe thunderstorms. I assume they're referring to PA, NJ, DE, and MD when talking about the Mid-Atlantic. Link to comment Share on other sites More sharing options...
yoda Posted July 28, 2021 Share Posted July 28, 2021 22 minutes ago, mattie g said: I assume they're referring to PA, NJ, DE, and MD when talking about the Mid-Atlantic. Most of VA was included in the SLGT risk and 5% tor Link to comment Share on other sites More sharing options...
mappy Posted July 28, 2021 Share Posted July 28, 2021 26 minutes ago, Kmlwx said: Uber-high risk and super-PDS watches then. I'm very greedy and needy with weather. Though...I'd trade no more severe for the rest of the calendar year for a single 36 inch snowstorm IMBY this winter. thats terrible. exciting weather all year round for all. 1 Link to comment Share on other sites More sharing options...
yoda Posted July 28, 2021 Share Posted July 28, 2021 Well written afternoon disco by LWX for tomorrow... but haven't seen some of that wording in a long time .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... Tomorrow`s forecast is a challenging one locally. A very strong MCS is expected to develop over the Upper Midwest/Lower Great Lakes this evening into tonight. This MCS should eventually weaken overnight as it moves into a lower CAPE environment over the Ohio Valley. A remnant outflow boundary/convective debris will spread over at least northern portions of the area tomorrow morning, with a connectively enhanced speed max in the 700-500 hPa layer following immediately in its wake. There is a wide spread of possible solutions in model guidance with respect to subsequent development of storms across our area tomorrow. Some solutions try to refire storms along the leading edge of the remnant outflow as it sweeps eastward across the area. Other solutions keep this activity suppressed. Other solutions fire additional storms in the wake of the convective debris. Some solutions do not. The environment in the wake of the leftover convective debris as the convectively enhanced speed max moves overhead is concerning. Models such as the NAM and Euro spread a belt of 40-50 knot flow in the 700-500 hPa layer over the northern half of our CWA by around peak heating. If we were to destabilize and storms were to form in that type of environment, the potential is there for a significant severe weather event, with very high winds, large hail, and tornadoes all possible. However, there`s considerable disagreement amongst the various models as to if and where storms will form in the wake of what`s left of today`s Upper Midwest system. Strong MCSs are often not handled well by both the CAMs and global guidance, and any system that forms today will have a strong influence on our weather for tomorrow. As a result, confidence in the evolution of storms tomorrow remains low. Confidence should gradually increase over time as today`s system gets going and becomes better handled by model guidance. We`ll continue to refine our forecast for what is a low confidence, but also potentially high impact severe weather event tomorrow. Link to comment Share on other sites More sharing options...
Kmlwx Posted July 28, 2021 Author Share Posted July 28, 2021 Long range 18z HRRR seems to contaminate/stabilize our airmass with leftovers from the complex from today. Link to comment Share on other sites More sharing options...
Eskimo Joe Posted July 28, 2021 Share Posted July 28, 2021 53 minutes ago, Kmlwx said: Uber-high risk and super-PDS watches then. I'm very greedy and needy with weather. Though...I'd trade no more severe for the rest of the calendar year for a single 36 inch snowstorm IMBY this winter. I've learned to accept the SVR and Winter climo of the area. Link to comment Share on other sites More sharing options...
H2O Posted July 28, 2021 Share Posted July 28, 2021 I haven’t. I’m just quieter about it. 1 Link to comment Share on other sites More sharing options...
Kmlwx Posted July 28, 2021 Author Share Posted July 28, 2021 3 minutes ago, Eskimo Joe said: I've learned to accept the SVR and Winter climo of the area. Honestly - at least from my weenie eyes, I think a ton of the CAMs are a snoozer for most tomorrow around here. Good parameters on some of them - but a relative min on the reflectivity panels. We'll see how that complex evolves tonight. Sure it'll screw us over. 1 Link to comment Share on other sites More sharing options...
Eskimo Joe Posted July 28, 2021 Share Posted July 28, 2021 23 minutes ago, Kmlwx said: Honestly - at least from my weenie eyes, I think a ton of the CAMs are a snoozer for most tomorrow around here. Good parameters on some of them - but a relative min on the reflectivity panels. We'll see how that complex evolves tonight. Sure it'll screw us over. Read LWX AFD again regarding CAMS. They'll shift 1,000 times through noon tomorrow and it'll drive you insane. If we're socked in at 11am tomorrow, then we'll know to just shrug the event off as another L. Link to comment Share on other sites More sharing options...
yoda Posted July 28, 2021 Share Posted July 28, 2021 Pretty nice soundings on the 18z NAM for the region at 21z and 00z tomorrow Link to comment Share on other sites More sharing options...
Kmlwx Posted July 28, 2021 Author Share Posted July 28, 2021 17 minutes ago, Eskimo Joe said: Read LWX AFD again regarding CAMS. They'll shift 1,000 times through noon tomorrow and it'll drive you insane. If we're socked in at 11am tomorrow, then we'll know to just shrug the event off as another L. This seems like a likely option. (I'm the new you) Link to comment Share on other sites More sharing options...
Eskimo Joe Posted July 28, 2021 Share Posted July 28, 2021 1 hour ago, Kmlwx said: This seems like a likely option. (I'm the new you) It's good to be clear eyed in this part of the country. We have so many small scale features that can disrupt things. Link to comment Share on other sites More sharing options...
yoda Posted July 28, 2021 Share Posted July 28, 2021 FWIW, confirmed SVR in St. Mary's County little while ago as spotters reported quarter sized hail in California 1 Link to comment Share on other sites More sharing options...
Stormfly Posted July 28, 2021 Share Posted July 28, 2021 3 hours ago, Eskimo Joe said: I've learned to accept the SVR and Winter climo of the area. I'm ok with it. Funny thing is it all gets built up and *poof* gone just like that. IME the most memorable events are the ones that catch you like a thief at night, no warning, unexpected. Bring the wind anytime! I'm constantly checking our trees and when a threat of damage from unexpected felling exists, it comes down. Stove is always hungry in the winter, less money for the oil guys and toasty comfort to boot. Of course my back cries uncle much sooner these days with the bigger logs but we have some plans to deal with that in the foreseeable future. Link to comment Share on other sites More sharing options...
Kmlwx Posted July 29, 2021 Author Share Posted July 29, 2021 Just walked out and heard a rumble of thunder - surprised at the radar right now. Link to comment Share on other sites More sharing options...
NorthArlington101 Posted July 29, 2021 Share Posted July 29, 2021 Hearing a lot of distant thunder in Arlington. Looks like a good one coming in. Link to comment Share on other sites More sharing options...
ErinInTheSky Posted July 29, 2021 Share Posted July 29, 2021 Absolutely beautiful storm rolling into DC south of me right now. Nonstop lightning, looks like a strobe light. Link to comment Share on other sites More sharing options...
Kmlwx Posted July 29, 2021 Author Share Posted July 29, 2021 No severe here IMBY but some nice rumbles of thunder. Hopefully an appetizer for tomorrow. Link to comment Share on other sites More sharing options...
jacindc Posted July 29, 2021 Share Posted July 29, 2021 Brother in Bethesda near River Road reporting incredible lightning, but no rain. Link to comment Share on other sites More sharing options...
jacindc Posted July 29, 2021 Share Posted July 29, 2021 "So much lightning the street lights turned off." 1 Link to comment Share on other sites More sharing options...
NorthArlington101 Posted July 29, 2021 Share Posted July 29, 2021 7 Link to comment Share on other sites More sharing options...
RandyHolt Posted July 29, 2021 Share Posted July 29, 2021 Had a good house shaker in west end rockville and picked up .6 1 Link to comment Share on other sites More sharing options...
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