caviman2201 Posted October 31, 2019 Share Posted October 31, 2019 Euro is actually calling for quite a bit of lightning with this line... seems hard to believe we'll see a ton of lightning on 10/31, but I guess with a front this strong its possible. Link to comment Share on other sites More sharing options...
Kmlwx Posted October 31, 2019 Share Posted October 31, 2019 That's a pretty strongly worded meso discussion for October on the east coast. Link to comment Share on other sites More sharing options...
Winter Wizard Posted October 31, 2019 Share Posted October 31, 2019 This is a pretty classic high shear, low cape severe event. Anything that develops later this afternoon (should be around 0z in the Blue Ridge, 2z near I-95) should quickly congeal into QLCS. The biggest concern is definitely the straight-line wind threat, although a brief spin up is not out of the question, with very strong speed and directional shear near the surface and a cranking LLJ. Question is, can we overcome that mid-level capping inversion and mix down to the surface as shown in the 0z DCA sounding? 1 Link to comment Share on other sites More sharing options...
yoda Posted October 31, 2019 Share Posted October 31, 2019 First TW of the day issued from KMRX in extreme SW VA Link to comment Share on other sites More sharing options...
H2O Posted October 31, 2019 Share Posted October 31, 2019 Too bad we didn't have any sun today. 2 Link to comment Share on other sites More sharing options...
Mrs.J Posted October 31, 2019 Share Posted October 31, 2019 Up to 68 here with winds picking up from the SW. Link to comment Share on other sites More sharing options...
yoda Posted October 31, 2019 Share Posted October 31, 2019 10% TOR PROBS AND 45% WIND PROBS ON 1630 OTLK 1 Link to comment Share on other sites More sharing options...
AmericanWxFreak Posted October 31, 2019 Share Posted October 31, 2019 2 minutes ago, yoda said: 10% TOR PROBS AND 45% WIND PROBS ON 1630 OTLK wow - thats impressive in the middle of June let alone Halloween! Link to comment Share on other sites More sharing options...
yoda Posted October 31, 2019 Share Posted October 31, 2019 Link to comment Share on other sites More sharing options...
yoda Posted October 31, 2019 Share Posted October 31, 2019 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1112 AM CDT Thu Oct 31 2019 Valid 311630Z - 011200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS PARTS OF NC...VA...WV...MD...DC...PA... ...SUMMARY... An extensive squall line of strong to severe thunderstorms is expected to develop during the late afternoon into this evening, near and east of the Appalachians from parts of New York to the Carolinas. At least a few tornadoes and scattered to widespread damaging winds are possible. ...Northeast to the Carolinas... Have upgraded peak probabilities for both wind and tornado hazards with an active period of severe weather anticipated later this afternoon into the evening. An amplifying shortwave trough now over IL will accelerate east-northeast toward the Saint Lawrence Valley through tonight toward PA/NY, while taking on a more neutral-to-negative tilt with peak 500 mb wind speeds exceeding 120 kt. Strong surface cyclogenesis is expected in advance of the amplifying trough, with a cyclone moving from OH to far southern QC by early Friday. South of the deepening cyclone, a strong cold front will sweep eastward across the Appalachians this afternoon, reaching the Atlantic coast overnight. The cold front will be the primary focus for severe thunderstorms through this evening. Northward advection of low-level moisture will continue with mid 60s boundary-layer dew points up the OH Valley west of the Appalachians and across southeast PA to coastal southern New England. Poor low to mid-level lapse rates amid widespread clouds will hinder destabilization with northern extent in the Northeast. Richer low-level moisture (upper 60s to low 70s boundary-layer dew points) and some surface heating in cloud breaks will support a confined plume of MLCAPE between 750-1500 J/kg across parts of VA into the Carolinas at peak heating. Within the warm sector, vertical shear will increase in response to the approach and deepening of the mid-level trough/surface cyclone. Long hodographs with effective bulk shear of 50-60 kt are expected, and there will also be enlarged low-level hodograph curvature for numerous rotating storms amid effective SRH of 300-500 m2/s2. Strong linear forcing for ascent along the cold front will be the primary focus for storm development, mainly east of the Appalachians later this afternoon/evening. The strong linear ascent will favor upscale growth into a squall line, though strong deep-layer shear and enough east component to storm motions should allow embedded supercell structures to persist. The modest buoyancy and very strong 850-700 mb flow will favor damaging winds as the primary threat. These could be potentially widespread within longer-tracked bowing segments. At least a few tornadoes are also anticipated with embedded supercell and mesovortex structures, particularly from central NC to central MD. The severe threat will diminish during the late evening to overnight given an increasing dearth of surface-based instability with east/northeast extent. ..Grams/Wendt.. 10/31/2019 Link to comment Share on other sites More sharing options...
mappy Posted October 31, 2019 Share Posted October 31, 2019 wow 10% tornado and 45% wind. Impressive. Link to comment Share on other sites More sharing options...
Eskimo Joe Posted October 31, 2019 Share Posted October 31, 2019 Over/under on TORs today? I say 5. Link to comment Share on other sites More sharing options...
yoda Posted October 31, 2019 Share Posted October 31, 2019 3 minutes ago, Eskimo Joe said: Over/under on TORs today? I say 5. That end up confirmed later on? Or just TWs issued by LWX? Link to comment Share on other sites More sharing options...
Eskimo Joe Posted October 31, 2019 Share Posted October 31, 2019 Just now, yoda said: That end up confirmed later on? Or just TWs issued by LWX? Just warnings issued by LWX Link to comment Share on other sites More sharing options...
Kmlwx Posted October 31, 2019 Share Posted October 31, 2019 WOW - That is a bold Outlook from SPC for this late in the year. Let's shoot for a moderate at 20z 1 Link to comment Share on other sites More sharing options...
yoda Posted October 31, 2019 Share Posted October 31, 2019 Tornado Watch issued to our west Link to comment Share on other sites More sharing options...
Kmlwx Posted October 31, 2019 Share Posted October 31, 2019 Pretty good slug of rain in the Rockville/Potomac area right now. Hope we can get a peak of sunshine or two to boost instability even more. Let's go big. Link to comment Share on other sites More sharing options...
NorthArlington101 Posted October 31, 2019 Share Posted October 31, 2019 Feel like this event deserves a thread. Link to comment Share on other sites More sharing options...
yoda Posted October 31, 2019 Share Posted October 31, 2019 URGENT - IMMEDIATE BROADCAST REQUESTED Tornado Watch Number 685 NWS Storm Prediction Center Norman OK 1245 PM EDT Thu Oct 31 2019 The NWS Storm Prediction Center has issued a * Tornado Watch for portions of Far east Kentucky Far northwest North Carolina Far northeast Tennessee Southwest Virginia West Virginia * Effective this Thursday afternoon and evening from 1245 PM until 700 PM EDT. * Primary threats include... A couple tornadoes possible Scattered damaging winds likely with isolated significant gusts to 75 mph possible SUMMARY...A thin line of low-topped convection should spread rapidly northeast this afternoon. Damaging winds from strong to locally severe wind gusts will be the primary hazard. Some intensification to the line is anticipated towards late afternoon, which should support a risk for a couple tornadoes. The tornado watch area is approximately along and 60 statute miles east and west of a line from 20 miles southeast of Bristol TN to 50 miles northwest of Elkins WV. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU5). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A Tornado Watch means conditions are favorable for tornadoes and 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. && AVIATION...Tornadoes and a few severe thunderstorms with hail surface and aloft to 0.5 inches. Extreme turbulence and surface wind gusts to 65 knots. A few cumulonimbi with maximum tops to 350. Mean storm motion vector 21045. Link to comment Share on other sites More sharing options...
Kmlwx Posted October 31, 2019 Share Posted October 31, 2019 The RAP has 47kts of 0-1km shear for a time in some areas this PM. That's legit. 1 Link to comment Share on other sites More sharing options...
yoda Posted October 31, 2019 Share Posted October 31, 2019 30/20 on the TOR probs and 70/30 on the WIND probs in that watch to our west Link to comment Share on other sites More sharing options...
Kmlwx Posted October 31, 2019 Share Posted October 31, 2019 Satellite shows some pockets of clearing ahead of the line associated with the tornado watch. Question will be whether that becomes clouded over more with stuff popping ahead of the line...or will the clearing sustain and move over our area later on. In my mind, any clearing is just bonus instability. Link to comment Share on other sites More sharing options...
Eskimo Joe Posted October 31, 2019 Share Posted October 31, 2019 95% chance of a WW: https://www.spc.noaa.gov/products/md/2019/md2129.html Link to comment Share on other sites More sharing options...
yoda Posted October 31, 2019 Share Posted October 31, 2019 5 minutes ago, Eskimo Joe said: 95% chance of a WW: https://www.spc.noaa.gov/products/md/2019/md2129.html Expected TOR too... and they mention potential discrete sups as well Mesoscale Discussion 2129 NWS Storm Prediction Center Norman OK 1211 PM CDT Thu Oct 31 2019 Areas affected...Parts of northern North Carolina...much of Virginia...western and central Maryland...south central Pennsylvania Concerning...Severe potential...Watch likely Valid 311711Z - 311945Z Probability of Watch Issuance...95 percent SUMMARY...One or more severe weather watches will likely be needed east of the Allegheny and Blue Ridge Mountains by 4-5 PM EDT. However, isolated severe storm development, including a risk for supercells, could require an earlier watch (likely tornado) issuance. DISCUSSION...Low-level and deep-layer shear are already strong to extreme across and east of the Allegheny and Blue Ridge Mountains, within deepening lee surface troughing, to the southeast of the intensifying surface cyclone now approaching Lake Erie. Despite weak mid/upper lapse rates, the northward return of seasonably moist boundary layer air (including surface dew points near 70F), coupled with boundary layer warming, is also contributing to modest destabilization across this region. Mixed-layer CAPE probably will continue to increase through the 500-1000+ J/kg range into mid to late afternoon, perhaps as far north as south central Pennsylvania. The primary increase in severe weather potential to the east of the Allegheny Mountains still appears likely to occur in association with an intensifying squall line near/just ahead of an approaching strengthening cold front, mainly during and after the 21-23Z time frame. However, it might not be out of the question that the ongoing destabilization, weakening inhibition, and perhaps forcing for ascent associated with weak warm advection, may become sufficient to support isolated to widely scattered discrete convective development in advance of the front. If this occurs, the environment will probably be conducive to supercells, which may be accompanied by the risk for tornadoes, in addition to localized strong surface gusts. ..Kerr/Grams.. 10/31/2019 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...AKQ...CTP...LWX...RAH...RNK...GSP... Link to comment Share on other sites More sharing options...
yoda Posted October 31, 2019 Share Posted October 31, 2019 Starting to see the heavy wording in the STW's being issued by MRX and RLX stating either "widespread wind damage is occuring" or "intense thunderstorm lines can produce brief tornadoes and widespread significant wind damage " Link to comment Share on other sites More sharing options...
high risk Posted October 31, 2019 Share Posted October 31, 2019 3 minutes ago, yoda said: Expected TOR too... and they mention potential discrete sups as well The HRRR does initiate a few supercells out ahead of the main forcing, so I understand SPC's thinking. But they form in western VA and move north-northeast into PA, consistent with where the box will be issued. Still think that the chances of discrete supercells in the DC metro area is really low. Link to comment Share on other sites More sharing options...
Kmlwx Posted October 31, 2019 Share Posted October 31, 2019 If we get sun I wonder if we get an outlook upgrade at 20z. I doubt it - I think we are at the max SPC would go for a late season event. But it's never out of the question. Link to comment Share on other sites More sharing options...
yoda Posted October 31, 2019 Share Posted October 31, 2019 Special Weather Statement National Weather Service Baltimore MD/Washington DC 1240 PM EDT Thu Oct 31 2019 ANZ530>543-DCZ001-MDZ003>006-011-013-014-016>018-501>508- VAZ025>031-036>040-050>057-501>508-WVZ050>053-055-501>506-010000- Chesapeake Bay north of Pooles Island MD- Chesapeake Bay from Pooles Island to Sandy Point MD- Chesapeake Bay from Sandy Point to North Beach MD- Chesapeake Bay from North Beach to Drum Point MD- Chesapeake Bay from Drum Point MD to Smith Point VA- Tidal Potomac from Key Bridge to Indian Head MD- Tidal Potomac from Indian Head to Cobb Island MD- Tidal Potomac from Cobb Island MD to Smith Point VA- Patapsco River including Baltimore Harbor- Chester River to Queenstown MD-Eastern Bay- Choptank River to Cambridge MD and the Little Choptank River- Patuxent River to Broomes Island MD- Tangier Sound and the inland waters surrounding Bloodsworth Island-District of Columbia-Washington-Frederick MD-Carroll- Northern Baltimore-Southern Baltimore-Prince Georges-Anne Arundel- Charles-St. Marys-Calvert-Extreme Western Allegany- Central and Eastern Allegany-Northwest Montgomery- Central and Southeast Montgomery-Northwest Howard- Central and Southeast Howard-Northwest Harford-Southeast Harford- Augusta-Rockingham-Shenandoah-Frederick VA-Page-Warren-Clarke- Nelson-Albemarle-Greene-Madison-Rappahannock-Orange-Culpeper- Prince William/Manassas/Manassas Park-Fairfax- Arlington/Falls Church/Alexandria-Stafford-Spotsylvania- King George-Northern Fauquier-Southern Fauquier-Western Highland- Eastern Highland-Western Loudoun-Eastern Loudoun- Northern Virginia Blue Ridge-Central Virginia Blue Ridge- Hampshire-Morgan-Berkeley-Jefferson-Hardy-Western Grant- Eastern Grant-Western Mineral-Eastern Mineral-Western Pendleton- Eastern Pendleton- Including the cities of Washington, Hagerstown, Frederick, Ballenger Creek, Eldersburg, Westminster, Reisterstown, Cockeysville, Baltimore, Bowie, Suitland-Silver Hill, Clinton, College Park, Greenbelt, Laurel, Camp Springs, Glen Burnie, Annapolis, Severn, South Gate, Severna Park, Arnold, Odenton, St. Charles, Waldorf, Lexington Park, California, Chesapeake Beach, Huntingtown, Dunkirk, North Beach, Lusby, Prince Frederick, Frostburg, Cumberland, Germantown, Damascus, Bethesda, Rockville, Gaithersburg, Silver Spring, Lisbon, Columbia, Ellicott City, Jarrettsville, Aberdeen, Staunton, Waynesboro, Stuarts Draft, Harrisonburg, Strasburg, Woodstock, Mount Jackson, New Market, Winchester, Luray, Shenandoah, Stanley, Front Royal, Berryville, Lovingston, Charlottesville, Stanardsville, Madison, Orange, Gordonsville, Culpeper, Dale City, Manassas, Woodbridge, Lake Ridge, Montclair, Reston, Herndon, Annandale, Centreville, Chantilly, McLean, Franconia, Arlington, Alexandria, Falls Church, Falmouth, Fredericksburg, Dahlgren, Warrenton, Turnbull, Hightown, Monterey, Purcellville, Leesburg, Ashburn, Sterling, Big Meadows, Wintergreen, Romney, Paw Paw, Martinsburg, Charles Town, Shepherdstown, Moorefield, Bayard, Mount Storm, Petersburg, Elk Garden, Antioch, Keyser, New Creek, Ridgeville, Russelldale, Headsville, Fort Ashby, Riverton, Brandywine, Franklin, Oak Flat, Ruddle, and Sugar Grove 1240 PM EDT Thu Oct 31 2019 ...DAMAGING LINE OF THUNDERSTORMS LIKELY TO MOVE EAST ACROSS THE AREA BETWEEN MID AFTERNOON AND MIDNIGHT... A line of thunderstorms is expected to move east across the region. These storms will bring the possibility of damaging wind gusts and isolated tornadoes. Please be sheltered when these thunderstorms pass through your area. The most likely timing of the line ranges from mid to late afternoon for the Potomac Highlands, to the evening for the Baltimore/Washington metros, to between 9pm and midnight for areas east of I-95 to the Chesapeake Bay. The storms will likely last an hour or less in most areas. Stay informed. For more exact timing for your location, consult the forecast for your community at our website weather.gov or our Facebook or Twitter feeds for National Weather Service Baltimore/Washington. $$ STRONG Link to comment Share on other sites More sharing options...
SilentTalkie Posted October 31, 2019 Share Posted October 31, 2019 17 minutes ago, Kmlwx said: Satellite shows some pockets of clearing ahead of the line associated with the tornado watch. Question will be whether that becomes clouded over more with stuff popping ahead of the line...or will the clearing sustain and move over our area later on. In my mind, any clearing is just bonus instability. There were some peaks of sun in Western Albemarle right after the line of showers but quickly clouded over again. Link to comment Share on other sites More sharing options...
NorthArlington101 Posted October 31, 2019 Share Posted October 31, 2019 Low level clouds are racing across the sky in Cville. I haven’t personally seen any sun. Probably gonna be stuck in class for the main event. Link to comment Share on other sites More sharing options...
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