yoda

Afternoon AFD from LWX - note it is long and very detailed Area Forecast Discussion National Weather Service Baltimore MD/Washington DC 402 PM EDT Thu Aug 8 2024 .SYNOPSIS... The remnants of Debby will move through the area tonight into Friday, before passing off toward our northeast on Friday night. Thereafter, high pressure will build over the area into early next week. && .NEAR TERM /THROUGH FRIDAY/... The latest NHC advisory shows Tropical Storm Debby centered along the North Carolina/South Carolina border. Well off to our northwest, a broad upper trough is centered over the Western Great Lakes and Upper Midwest. Debby`s circulation is starting to feel the influence of that trough well off to our northwest, and is being drawn northward in response. As this interaction with the upstream trough occurs, Debby will also start to turn extratropical in nature. As we move forward in time, the remnants of Debby will track northward through the Shenandoah Valley tonight, before moving northward across Pennsylvania tomorrow. The system should eventually reach upstate New York by tomorrow evening. As the system tracks northward through our area it will produce a number of weather hazards, which are discussed more in-depth below... Heavy Rainfall/Flooding: Current radar imagery shows numerous showers/downpours ongoing in advance of Debby`s main circulation across northern Virginia, Maryland, and the West Virginia Panhandle. These heavier showers are occurring within a warm/moist advection regime ahead of Debby, and are producing very heavy rainfall for brief periods of time. Due to the rather disorganized nature and brief duration of these showers, flooding isn`t anticipated. However, they may lead to brief reduced visibility, or some ponding on roadways. The main precipitation shield associated with Debby is just starting to work into central Virginia, with the heaviest rainfall situated across southern Virginia. The heaviest of these rains will work northward into central Virginia over the next several hours, and continue across central Virginia through at least the first half of the night. The steadiest rains may move to the north of central Virginia during the second half of the night, but more intermittent heavier bursts of convective rainfall may still be possible through the second half of the night. The steadier precipitation shield will spread northward through the Shenandoah Valley and Potomac Highlands through the night. Very heavy rainfall will likely lead to widespread flooding issues tonight from central Virginia northward through the Shenandoah Valley. A rare High Risk for excessive rainfall from WPC has been issued across these areas. The West Virginia Panhandle and western Maryland will also get into the steady, heavy rainfall tonight, with much of it falling during the second half of the night. These locations will likely experiences issues with Flash Flooding during the second half of the night. Overall, a widespread 3-5 inches of rainfall is expected for these locations, with isolated totals up to 7 inches. Locally higher totals approaching 10 inches may be possible along the east facing slopes of the Blue Ridge, where upslope easterly flow may will lead to orographic enhancement of the rain. For those reasons, the above locations are in a Flood Watch for flash flooding from 8 PM tonight through 8 PM tomorrow. Further east, rainfall will be more intermittent and showery along the I-95 corridor tonight as the core of the system passes to the west. As a result, issues with flooding aren`t anticipated overnight. Tomorrow, as the system tracks northward into Pennsylvania, a feeder rainfall band is expected to develop to the south of the circulation and slowly track eastward across locations to the east of the Blue Ridge. Very heavy rainfall may be possible within this band, and could lead to localized instances of flash flooding where training occurs. Confidence in widespread flooding associated with this activity tomorrow morning through mid-afternoon tomorrow remains too low for a Flood Watch, but one may potentially be considered at a later time. For locations further east (outside of the Flood Watch), a broad 1-3 inches of rainfall is expected, with more localized totals up to 5 inches. Rainfall should finally move out of the area late tomorrow afternoon. Tornadoes: There is growing concern that tornadoes may impact portions of the area, especially later this evening into the overnight hours. The zone with an environment most favorable for tornadoes is currently located to our south over southern Virginia and North Carolina. Over time, this environment characterized by ample shear in the low levels, limited instability, and large curved hodographs will lift northward into our area, with tornado potential in central Virginia likely beginning somewhere within the 6-8 PM time window. As the system tracks northward through the night, the area favorable for tornadoes will spread northward through the Shenandoah Valley and into the West Virginia Panhandle. SPC has highlighted these locations in a Slight Risk for severe thunderstorms, driven by tornadoes. With the potential for most of this activity to occur after dark, we encourage people to have a way to receive tornado warnings at night, and to be ready to take shelter in the middle of the night, if needed. The threat for tornadoes may shift eastward tomorrow to locations east of the Blue Ridge within the aforementioned feeder band that will develop to the south of the circulation as it tracks into Pennsylvania. Any tornado potential tomorrow would likely be maximized during the morning to early afternoon hours. SPC has upgraded the Baltimore area to a Slight Risk for severe thunderstorms tomorrow, with the threat being driven by both tornadoes and damaging straight line winds. Overall, 0-1 km SRH is lower compared to overnight, so that may lead to a slightly lower tornado potential than overnight, but chances for straight line winds will be increased as limited heating and destabilization occurs ahead of the convective line. Background winds: Outside of any thunderstorms, winds may gust to around 30-40 mph at times, especially during the daylight hours to the east of the Blue Ridge. This may be enough to bring down a few trees with saturated soil conditions, but is below the Wind Advisory threshold of 40 knots/46 mph.

LWX seems quite concerned about tornadoes overnight in their afternoon AFD

The highlighted areas in the watch in the Bay are all under Wakefield's WFO

Hopefully that will give them the chance to clean up all the downed trees then

SPC declines and says head SW 5% is in E PA into NJ

I don't see LWX attached to the watchbox at all

40/20 tor probs... kind of surprised at the 20

URGENT - IMMEDIATE BROADCAST REQUESTED Tornado Watch Number 614 NWS Storm Prediction Center Norman OK 1245 PM EDT Thu Aug 8 2024 The NWS Storm Prediction Center has issued a * Tornado Watch for portions of Central and Eastern North Carolina Central and Southeast Virginia Coastal Waters * Effective this Thursday afternoon and evening from 1245 PM until 800 PM EDT. * Primary threats include... A couple tornadoes possible SUMMARY...Thunderstorms embedded within the outer bands of Tropical Storm Debby will continue to track northeastward across the watch area through the afternoon, posing a risk of a few tornadoes. The tornado watch area is approximately along and 80 statute miles east and west of a line from 50 miles northwest of Richmond VA to 50 miles southeast of New Bern NC. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU4). 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.

Are you sure you are measuring in the correct Stephens City?

Recurves out to sea

Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1105 AM CDT Thu Aug 08 2024 Valid 081630Z - 091200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND TONIGHT OVER PORTIONS OF NORTH CAROLINA AND THE MID ATLANTIC REGION... ...SUMMARY... Isolated tornadoes are possible today and tonight over portions of the Mid Atlantic region. Strong thunderstorm wind gusts may affect portions of Utah and Arizona. ...Mid Atlantic... The center of circulation of TS Debby will lift northward today and tonight across central NC/VA, with the zone of strongest low level winds/shear just to the northeast of the low. A consensus of 12z CAM solutions suggest the main threat of semi-discrete convection and a few tornadoes this afternoon and evening will be across north-central NC and south-central VA. This threat will build northward into parts of northern VA and the Eastern WV Panhandle after dark, and eventually into central PA by Friday morning. Please refer to MCD #1866 for further short-term details.

1630z OTLK from SPC pushed the SLGT risk and 5% tor northward a good amount to the Mason-Dixon line

Sounds like it... but probably won't extend into LWX CWA yet

BULLETIN - EAS ACTIVATION REQUESTED Flash Flood Warning National Weather Service Baltimore MD/Washington DC 1035 PM EDT Wed Aug 7 2024 The National Weather Service in Sterling Virginia has issued a * Flash Flood Warning for... North Central Loudoun County in northern Virginia... * Until 145 AM EDT. * At 1035 PM EDT, Doppler radar indicated thunderstorms producing heavy rain across the warned area. Between 2 and 4 inches of rain have fallen. Additional rainfall amounts of 1 to 2 inches are possible in the warned area. Flash flooding is ongoing or expected to begin shortly. HAZARD...Flash flooding caused by thunderstorms. SOURCE...Radar. IMPACT...Flash flooding of small creeks and streams, urban areas, highways, streets and underpasses as well as other poor drainage and low-lying areas. * Some locations that will experience flash flooding include... Purcellville... Round Hill... Hamilton... Hillsboro... Lincoln... Hughesville... PRECAUTIONARY/PREPAREDNESS ACTIONS... Turn around, don`t drown when encountering flooded roads. Most flood deaths occur in vehicles. Be especially cautious at night when it is harder to recognize the dangers of flooding.

4pm afternoon AFD from LWX about Debby SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/... The remnants of Debby will start to lift northward tomorrow as it begins to feel the influence of troughing well off toward the northwest over the Great Lakes. While the main circulation associated with the remnants of Debby will remain off to our south during the daylight hours tomorrow, a weak lobe of shear vorticity in the mid-levels to the north of Debby will lift northward through locations to the east of the Blue Ridge. Differential cyclonic vorticity advection ahead of this feature may provide enough lift to initiate some showers and thunderstorms tomorrow morning through the first half of the afternoon. Any storms tomorrow morning may be capable of producing very heavy rainfall within what will be a tropical airmass characterized by precipitable water values over two inches. Confidence was too low for a Flood Watch to the east of the Blue Ridge at this time, but one may eventually need to be considered for during the day tomorrow. To the west of the Blue Ridge, showers and a few thunderstorms can`t be ruled out, but much of the day should remain dry. Tomorrow night attention will turn to the remnants of Debby as it lifts northward and starts to interact with a trough off to our northwest. The main core of the system is expected to lift northward from central Virginia through the Shenandoah Valley and Potomac Highlands tomorrow night. Very heavy rainfall is expected over those locations tomorrow night into the first half of Friday. A Flood Watch for flash flooding has been issued for those locations, where a widespread 3-5 inches of rain is expected, with isolated totals of up to 7 inches. To the east of the Blue Ridge, much of the night may remain dry as Debby`s remnant circulation passes off toward the west. Another concern tomorrow night and into the day Friday will be tornadoes. With the system`s surface low taking a track over the Alleghenies, a very favorable shear profile and limited instability will move northward across central Virginia and the Shenandoah Valley tomorrow night. SPC has expanded both the Marginal and Slight risks northward through our area to account for this potential tornado activity tomorrow night. As we move through the day Friday, the system`s surface low will lift northeastward across PA. As it does so, a southward trailing convective line will track eastward across locations to the east of the Blue Ridge. This line of storms may be capable of producing very heavy rainfall, as well as tornadoes. Since this convective line will be a smaller scale feature, we have decided to hold off on issuing a Flood Watch to the east of the Blue Ridge for the time being. The line of storms associated with the remnants of Debby should progress east of the area Friday evening, with dry conditions expected during the second half of Friday night.

Flood Watch National Weather Service Baltimore MD/Washington DC 243 PM EDT Wed Aug 7 2024 MDZ001-003-501-502-VAZ025>031-036>040-050-051-503-504-507-508- WVZ050>053-055-501>506-080245- /O.NEW.KLWX.FA.A.0021.240809T0000Z-240810T0000Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ Garrett-Washington-Extreme Western Allegany-Central and Eastern Allegany-Augusta-Rockingham-Shenandoah-Frederick VA-Page-Warren- Clarke-Nelson-Albemarle-Greene-Madison-Rappahannock-Orange- Culpeper-Western Highland-Eastern Highland-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 Orange, Winchester, Grantsville, Mount Storm, Big Meadows, Ridgeville, Oakland, Harrisonburg, Wintergreen, Sugar Grove, Monterey, Front Royal, Staunton, Waynesboro, Bayard, Petersburg, Riverton, Hagerstown, New Market, Keyser, Charles Town, New Creek, Stanley, Russelldale, Lovingston, Madison, Shenandoah, Mountain Lake Park, Fort Ashby, Oak Flat, Frostburg, Woodstock, Luray, Moorefield, Shepherdstown, Berryville, Culpeper, Martinsburg, Mount Jackson, Washington, Brandywine, Hightown, Stanardsville, Cumberland, Paw Paw, Charlottesville, Franklin, Strasburg, Romney, Antioch, Ruddle, Stuarts Draft, Headsville, Elk Garden, and Gordonsville 243 PM EDT Wed Aug 7 2024 ...FLOOD WATCH IN EFFECT FROM THURSDAY EVENING THROUGH FRIDAY EVENING... * WHAT...Flash flooding caused by excessive rainfall is possible. * WHERE...Portions of Maryland, including the following areas, Central and Eastern Allegany, Extreme Western Allegany, Garrett and Washington, Virginia, including the following areas, Albemarle, Augusta, Central Virginia Blue Ridge, Clarke, Culpeper, Eastern Highland, Frederick VA, Greene, Madison, Nelson, Northern Virginia Blue Ridge, Orange, Page, Rappahannock, Rockingham, Shenandoah, Warren and Western Highland, and West Virginia, including the following areas, Berkeley, Eastern Grant, Eastern Mineral, Eastern Pendleton, Hampshire, Hardy, Jefferson, Morgan, Western Grant, Western Mineral and Western Pendleton. * WHEN...From Thursday evening through Friday evening. * IMPACTS...Excessive runoff may result in flooding of rivers, creeks, streams, and other low-lying and flood-prone locations. * ADDITIONAL DETAILS... - The remnants of Debby will move northward through the area, leading to heavy rainfall Thursday night into Friday. A widespread 3 to 5 inches of rainfall is expected within the Watch area, with localized totals up to 7 inches. - Please visit www.weather.gov/safety/flood for flood safety and preparedness information

Day 2 SPC OTLK moved SLGT risk NW quite alot

11pm track from NHC pretty much the same... along or just east of i81 corridor

H/t @mitchnick

FWIW, 18z Euro has Debby going up the i81 corridor

5pm track of Debby is along or just east of the i81 corridor

That's too much rainfall

Flood Watch National Weather Service Baltimore MD/Washington DC 322 PM EDT Tue Aug 6 2024 MDZ006-008-011-507-508-070330- /O.NEW.KLWX.FA.A.0020.240806T1922Z-240807T0800Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ Northern Baltimore-Cecil-Southern Baltimore-Northwest Harford- Southeast Harford- Including the cities of Jarrettsville, Elkton, Cockeysville, Reisterstown, Baltimore, and Aberdeen 322 PM EDT Tue Aug 6 2024 ...FLOOD WATCH IN EFFECT THROUGH LATE TONIGHT... * WHAT...Flash flooding caused by excessive rainfall is possible. * WHERE...Portions of northeast and northern Maryland, including the following areas, in northeast Maryland, Cecil. In northern Maryland, Northern Baltimore, Northwest Harford, Southeast Harford and Southern Baltimore. * WHEN...Through late tonight. * IMPACTS...Excessive runoff may result in flooding of rivers, creeks, streams, and other low-lying and flood-prone locations. * ADDITIONAL DETAILS... - Recent heavy rainfall has significantly lowered flash flood guidance in northeast Maryland in recent days, including several inches today in isolated spots. More torrential rainfall is possible this afternoon as multiple mesoscale convective complexes push through, which may result in flash flooding. Generally, most places will get another inch or so form this, but isolated spots where training occurs could see 2 to 3 inches of rainfall in a relatively short period of time. - Please visit www.weather.gov/safety/flood for flood safety and preparedness information