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Everything posted by yoda
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12z sounding PWATs at RNK was 1.60... WAL 2.12... IAD 1.99
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https://www.wpc.ncep.noaa.gov/discussions/hpcdiscussions.php?disc=qpferd
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Uh oh .NEAR TERM /THROUGH TONIGHT/... Early morning RAP and observations analysis shows a stalled frontal boundary draped along the PA/MD border, stretching westward across the OH Valley. This region and the Mid-Atlantic are sandwiched between the Bermuda High (which is well west of its normal climo position in the western Atlantic) and a weaker surface high over the Upper Great Lakes. Abundant high level clouds this morning are expected to persist all day, with building low level clouds once mixing starts shortly after sunrise. This is going to keep highs lower today, mainly in the low to mid 80s. Peak heat indices reach the mid to upper 90s in Central VA. Southerly flow into the stalled boundary continues to advect deep tropical moisture into the region, so expect PWATs to jump well over 2" once again this afternoon. Aloft, a well timed shortwave trough looks to move across our area during peak heating and the main convective time window this afternoon to early evening. Modest deep- layer westerly shear around 30 knots will be enough to support organized deep convection, especially over the Shenandoah Valley and Central VA. More than enough instability is going to be present in this hot and humid airmass, with SBCAPE values of 1000-2000 J/kg. This is where SPC has a Slight Risk (level 2 of 5) for severe storms today, with damaging wind gusts as the main threat. The threat for thunderstorms really drops off quickly north/east of the Potomac River, with the Baltimore Metro to NE MD likely to stay clear for the most part today. The main threat is going to be flash flooding, which could be very significant in parts of the Shenandoah Valley. The tropical airmass will easily support rainfall rates of 1-2+" in 30 minutes, with hourly rainfall rates of 3-4" possible in the heaviest thunderstorms. Any area that sees either multiple rounds or training thunderstorms is likely to experience some flooding. Particularly worrying is the RRFS ensembles showing up to 40pct chance of seeing 100yr RI rainfall amounts (which equates to roughly 5" or more of rain) in the central Shenandoah Valley. The HREF max QPF also indicates the high-end potential of 4-7" of rain. Now these extreme amounts won`t be widespread and might not occur, but the potential is definitely there for worst-case scenario flash flooding. As a result, a Moderate Risk of flash flooding has been coordinated with WPC for the Central Shenandoah Valley, Blue Ridge Mountains, and portions of the Central VA Piedmont. Elsewhere, a Slight Risk of flash flooding extends north/east to around the Potomac River. A (Flash) Flood Watch has been issued. Scattered showers and thunderstorms could linger late into the evening. Some CAMs indicate outflow boundaries generating additional convection into the DC Metro and Southern MD late into the evening. Muggy conditions continue tonight as temps settle in the upper 60s to mid 70s. Low clouds and patchy fog are possible late tonight.
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It looked good until the storms to the west of it nommed it
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Oh boy URGENT - WEATHER MESSAGE National Weather Service Baltimore MD/Washington DC 439 PM EDT Wed Jul 16 2025 DCZ001-MDZ008-011-013-014-016>018-508-VAZ053>055-057-527-170445- /O.NEW.KLWX.HT.Y.0007.250717T1500Z-250718T0000Z/ District of Columbia-Cecil-Southern Baltimore-Prince Georges-Anne Arundel-Charles-St. Marys-Calvert-Southeast Harford-Fairfax- Arlington/Falls Church/Alexandria-Stafford-King George-Central and Southeast Prince William/Manassas/Manassas Park- 439 PM EDT Wed Jul 16 2025 ...HEAT ADVISORY IN EFFECT FROM 11 AM TO 8 PM EDT THURSDAY... * WHAT...Heat index values around 105 expected. * WHERE...Washington DC, and portions of central, northern, and southern Maryland, and central and northern Virginia. * WHEN...From 11 AM to 8 PM EDT Thursday. * IMPACTS...Hot temperatures and high humidity may cause heat illnesses. PRECAUTIONARY/PREPAREDNESS ACTIONS... Drink plenty of fluids, stay in an air-conditioned room, stay out of the sun, and check up on relatives and neighbors. Take extra precautions when outside. Wear lightweight and loose fitting clothing. Try to limit strenuous activities to early morning or evening. Take action when you see symptoms of heat exhaustion and heat stroke.
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BULLETIN - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Warning National Weather Service Baltimore MD/Washington DC 708 PM EDT Wed Jul 16 2025 The National Weather Service in Sterling Virginia has issued a * Severe Thunderstorm Warning for... East central Rappahannock County in northwestern Virginia... West central Fauquier County in northern Virginia... * Until 745 PM EDT. * At 708 PM EDT, a severe thunderstorm was located near Hume, or 11 miles southeast of Front Royal, moving east at 15 mph. HAZARD...60 mph wind gusts and quarter 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... Flint Hill, Cresthill, and Orlean. PRECAUTIONARY/PREPAREDNESS ACTIONS... Remain alert for a possible tornado! Tornadoes can develop quickly from severe thunderstorms. If you spot a tornado go at once into the basement or small central room in a sturdy structure. For your protection move to an interior room on the lowest floor of a building. Large hail, damaging wind, and continuous cloud to ground lightning are occurring with this storm. Move indoors immediately. Lightning is one of nature`s leading killers. Remember, if you can hear thunder, you are close enough to be struck by lightning. Torrential rainfall is occurring with this storm, and may lead to flash flooding. Do not drive your vehicle through flooded roadways. && LAT...LON 3875 7813 3878 7813 3878 7794 3871 7790 TIME...MOT...LOC 2308Z 276DEG 13KT 3877 7809 TORNADO...POSSIBLE HAIL THREAT...RADAR INDICATED MAX HAIL SIZE...1.00 IN WIND THREAT...RADAR INDICATED MAX WIND GUST...60 MPH
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Severe Weather Statement National Weather Service Baltimore MD/Washington DC 710 PM EDT Wed Jul 16 2025 VAC107-162345- /O.CON.KLWX.SV.W.0303.000000T0000Z-250716T2345Z/ Loudoun VA- 710 PM EDT Wed Jul 16 2025 ...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 745 PM EDT FOR NORTHEASTERN LOUDOUN COUNTY... At 710 PM EDT, a severe thunderstorm was located near Purcellville, or 7 miles northwest of Leesburg, moving east at 15 mph. HAZARD...70 mph wind gusts and quarter 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... Leesburg, Lovettsville, Paeonian Springs, Lucketts, Waterford, and Taylorstown. PRECAUTIONARY/PREPAREDNESS ACTIONS... For your protection move to an interior room on the lowest floor of a building. Continuous cloud to ground lightning is occurring with this storm. Move indoors immediately. Lightning is one of nature`s leading killers. Remember, if you can hear thunder, you are close enough to be struck by lightning. Torrential rainfall is occurring with this storm, and may lead to flash flooding. Do not drive your vehicle through flooded roadways. && LAT...LON 3919 7772 3929 7767 3926 7752 3925 7749 3922 7746 3921 7747 3919 7748 3918 7751 3915 7753 3914 7753 3908 7758 TIME...MOT...LOC 2310Z 292DEG 12KT 3919 7763 THUNDERSTORM DAMAGE THREAT...CONSIDERABLE HAIL THREAT...RADAR INDICATED MAX HAIL SIZE...1.00 IN WIND THREAT...RADAR INDICATED MAX WIND GUST...70 MPH
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Tor possible tag on the Fauquier warned storm
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That storm in Loudoun looks mighty interesting
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Thank you for sacrificing
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Flood Watch National Weather Service Baltimore MD/Washington DC 1137 AM EDT Sun Jul 13 2025 DCZ001-MDZ003>006-011-013-014-016-501>510-VAZ025>031-036>040-050-051- 053>057-501>508-526-527-WVZ050>053-055-501>506-132345- /O.NEW.KLWX.FA.A.0025.250713T1600Z-250714T0600Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ District of Columbia-Washington-Frederick MD-Carroll-Northern Baltimore-Southern Baltimore-Prince Georges-Anne Arundel-Charles- Extreme Western Allegany-Central and Eastern Allegany-Northwest Montgomery-Central and Southeast Montgomery-Northwest Howard- Central and Southeast Howard-Northwest Harford-Southeast Harford- Western Garrett-Eastern Garrett-Augusta-Rockingham-Shenandoah- Frederick VA-Page-Warren-Clarke-Nelson-Albemarle-Greene-Madison- Rappahannock-Orange-Culpeper-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-Northwest Prince William-Central and Southeast Prince William/Manassas/Manassas Park-Hampshire-Morgan- Berkeley-Jefferson-Hardy-Western Grant-Eastern Grant-Western Mineral-Eastern Mineral-Western Pendleton-Eastern Pendleton- 1137 AM EDT Sun Jul 13 2025 ...FLOOD WATCH IN EFFECT THROUGH LATE TONIGHT... * WHAT...Flash flooding caused by excessive rainfall is possible. * WHERE...The District of Columbia, and portions of Maryland, including the following areas, Anne Arundel, Carroll, Central and Eastern Allegany, Central and Southeast Howard, Central and Southeast Montgomery, Charles, Eastern Garrett, Extreme Western Allegany, Frederick MD, Northern Baltimore, Northwest Harford, Northwest Howard, Northwest Montgomery, Prince Georges, Southeast Harford, Southern Baltimore, Washington and Western Garrett, Virginia, including the following areas, Albemarle, Arlington/Falls Church/Alexandria, Augusta, Central Virginia Blue Ridge, Central and Southeast Prince William/Manassas/Manassas Park, Clarke, Culpeper, Eastern Highland, Eastern Loudoun, Fairfax, Frederick VA, Greene, King George, Madison, Nelson, Northern Fauquier, Northern Virginia Blue Ridge, Northwest Prince William, Orange, Page, Rappahannock, Rockingham, Shenandoah, Southern Fauquier, Spotsylvania, Stafford, Warren, Western Highland and Western Loudoun, 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...Through 2 AM tonight. * IMPACTS...Excessive runoff may result in flooding of rivers, creeks, streams, and other low-lying and flood-prone locations. * ADDITIONAL DETAILS... - Showers and thunderstorms will form this afternoon and linger on and off through the first half of the night. Storms will be slow moving and capable of producing very heavy rainfall. Rainfall totals of 1 to 2 inches appear likely for locations that receive thunderstorms, with isolated totals of 2 to 4 inches. The strongest thunderstorms may be capable of producing 1.5 to 2.5 inches of rain in an hour. - Please visit www.weather.gov/safety/flood for flood safety and preparedness information
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Hope this hasn't been posted yet, if so my mistake... saw this new study this morning. Looks interesting and will be reading... but I appreciate any thoughts by our experts here https://www.google.com/amp/s/phys.org/news/2025-07-polar-vortex-patterns-shifting-winter.amp https://www.science.org/doi/10.1126/sciadv.adq9557
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You mean December to February
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Thoughts? https://x.com/BenNollWeather/status/1943673129965949186
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SLGT risk for severe tomorrow on the updated afternoon 1730z SPC OTLK
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Yay URGENT - WEATHER MESSAGE National Weather Service Baltimore MD/Washington DC 1231 PM EDT Mon Jul 7 2025 MDZ008-011-013-014-016>018-508-VAZ057-080045- /O.NEW.KLWX.HT.Y.0006.250708T1700Z-250708T2300Z/ Cecil-Southern Baltimore-Prince Georges-Anne Arundel-Charles-St. Marys-Calvert-Southeast Harford-King George- 1231 PM EDT Mon Jul 7 2025 ...HEAT ADVISORY IN EFFECT FROM 1 PM TO 7 PM EDT TUESDAY... * WHAT...Heat index values up to 105 expected, up to 107 degrees closer to the Chesapeake Bay. * WHERE...In Maryland, Anne Arundel, Prince Georges, Cecil, Southeast Harford, Southern Baltimore, Calvert, Charles, and St. Marys Counties. In Virginia, King George County. * WHEN...From 1 PM to 7 PM EDT Tuesday. * IMPACTS...Hot temperatures and high humidity may cause heat illnesses. PRECAUTIONARY/PREPAREDNESS ACTIONS... Drink plenty of fluids, stay in an air-conditioned room, stay out of the sun, and check up on relatives and neighbors. To reduce risk during outdoor work, the Occupational Safety and Health Administration recommends scheduling frequent rest breaks in shaded or air conditioned environments. Anyone overcome by heat should be moved to a cool and shaded location. Heat stroke is an emergency! Call 9 1 1.
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Slight Risk for tomorrow for the region per updated day 2 from SPC
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Mesoscale Discussion 1529 NWS Storm Prediction Center Norman OK 1048 AM CDT Tue Jul 01 2025 Areas affected...the Mid-Atlantic States Concerning...Severe potential...Severe Thunderstorm Watch likely Valid 011548Z - 011745Z Probability of Watch Issuance...95 percent SUMMARY...An increasing damaging wind threat and Severe Thunderstorm Watch issuance are expected this afternoon DISCUSSION...Convection has been slowly building across the central Appalachians, ahead of a low-amplitude shortwave trough that is progressing east across the Upper OH Valley. While there is some near-term uncertainty of how quickly this initial activity will strengthen amid weak DCAPE, the downstream airmass east of the Blue Ridge is destabilizing well as surface temperatures have already warmed into the upper 80s to low 90s. This will yield an uptick in convective intensity as clusters impinge on the Piedmont to Coastal Plain where mid 70s surface dew points are pervasive. Although lower-level winds will remain weak and predominately veered, moderate mid to upper-level westerlies will support organized multicells capable of producing multiple strong to isolated severe gust swaths. Scattered damaging winds appear likely towards mid to late afternoon. ..Grams/Mosier.. 07/01/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...PHI...AKQ...CTP...LWX... LAT...LON 40117372 39117452 37967617 37757901 38627929 40127907 40667848 40497568 40117372 MOST PROBABLE PEAK WIND GUST...55-70 MPH
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Watch coming soon per MCD https://www.spc.noaa.gov/products/md/md1529.html
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Hope you had a great birthday @mappy Sorry I'm late, I'm in England right now
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A SLGT risk appears for this afternoon
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Would be kind of ironic if today we reached 100 degrees
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96 now at DCA... so got about 4 more hours to reach 100
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FWIW, JFK is at 102