yoda

Watch up until 10pm for entire LWX CWA

2pm DCA 100 BWI 101 IAD 97 RIC 99 CHO 101 SBY 100

1pm temps DCA 100 BWI 101 IAD 96 RIC 97 CHO 99 SBY 99

Updated 1730z SPC OTLK for Day 2 (tomorrow, Sunday) has added 5 hail and 30 wind Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1203 PM CDT Sat Jul 04 2026 Valid 051200Z - 061200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE MID-ATLANTIC SUNDAY AFTERNOON AND EVENING... ...SUMMARY... Scattered wind damage is possible with thunderstorms across the Mid-Atlantic Sunday afternoon and evening. Isolated strong storms also are possible across Montana and western North Dakota, and portions of the southern Plains to the Tennessee Valley. ...Mid-Atlantic... A weak surface low is forecast to move west to east along a sagging cold front/baroclinic zone draped across PA into northern NJ/southeast NY on Sunday/Sunday evening. Meanwhile, lee troughing will develop across VA. A hot and very moist airmass will reside near and south of these boundaries, which will serve as a focus for severe storm development during the afternoon and into evening. Southwesterly flow aloft will weaken through the day as an upper shortwave impulse lifts northeast of the region, but around 20-30 kt mid/upper-level flow will persist. Moderate to strong destabilization is expected and thunderstorm clusters are expected by early to mid-afternoon. Sufficient clustering could occur along the southward-sagging cold front and one or more forward propagating clusters will be possible from northern VA into southeast PA until storms move offshore the Mid-Atlantic coast during the evening. Sufficient consistency among deterministic/CAMs and AI/ML guidance exists regarding storm coverage to warrant an upgrade to 30 percent wind probabilities for portions of the region.

ATTN...WFO...AKQ...LWX...RNK...PBZ...RLX... LAT...LON 37548059 38018032 39057934 39427883 39597832 39647744 39547686 39357649 38907637 38057671 37237763 36667909 36688013 37028055 37548059 MOST PROBABLE PEAK WIND GUST...65-80 MPH MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN https://www.spc.noaa.gov/products/md/md1491.html

I would assume we would

3 days in a row... impressive

Geez... from the 1125am LWX updated discussion Unlike previous days which were free of convection, a collapsing ridge will lift the subsidence that has persisted the last few days. This subsidence is evident in two levels in the 12Z KIAD RAOB - 900-800 mb, and 575-525 mb (the latter of which is more stout than forecast most forecast soundings have). Although mid/upper heights remain anomalously high, forcing from an approaching shortwave will aid in more widespread showers and thunderstorms. One unique aspect to the thermodynamic environment is an elevated mixed layer (EML) which has shown up in the last 5 IAD sounding profiles (9.3 C/km this morning 780-570 mb). This is unusually steep for this area. This is contributing to some impressively large amounts of instability, generally 2,000 to 4,000 J/kg MUCAPE as of 12Z objective mesoanalysis. Within the deeply mixed boundary layer, substantial downdraft CAPE (DCAPE) is evident with values around 1,300 to 1,700 J/kg. Although vertical shear is only around 20 to 25 knots, any storms able to tap into the robust instability will be capable of damaging winds. Some of this could be locally considerable with gusts up to 70 mph. With all of the above in mind, and ample high-resolution model support, the Storm Prediction Center has upgraded areas east of the Blue Ridge to an Enhanced Risk today. This upgrade would support a more widespread footprint of severe thunderstorms this afternoon and evening. Looking a bit more closely at today`s setup, convective initiation likely will be more mesoscale in nature. This would include the climatological lee-side trough, bay and river breezes, as well as any remnant outflows from earlier convection. Multiple rounds of thunderstorms are possible given so much instability in the troposphere. The primary signal east of the Blue Ridge is in the 3-9 PM timeframe, slightly earlier to the west. Damaging winds are the main threat, with even a small chance for large hail given steep lapse rates and large CAPE (though high freezing levels and modest shear will offset this risk). Although the convective signal is strongest during the afternoon to early evening hours, residual storms could easily impact those with outdoor plans for fireworks this evening. Continue to check back at weather.gov/lwx or follow the National Weather Service - Baltimore/Washington social media accounts for the latest.

Yes CIG1 for wind introduced along i95 corridor from DC metro into PHL

5% hail introduced on 1630z OTLK from Roanoke VA to DC metro

https://www.capitalweather.com/100-degree-days-in-washington-d-c/ 1930 had 11 2012 had 8

I could see a CIG1 appear in the 1300z SPC OTLK or the 1630z one

Probably good thing we dont have shear near 40 kts .DISCUSSION... KEY MESSAGE 1...A highly impactful Independence Day lies ahead today with extreme heat and an Enhanced Risk for severe thunderstorms. Anomalous heat and humidity remain a fixture across the area. Based on the latest 07Z/3 AM observational data, temperatures generally range from the mid 70s to mid 80s. This is accompanied by dew points in the 70s which is yielding overnight heat indices between 85 to 95 degrees. Skies remain mostly clear although there is still residual convective debris drifting southward from central Pennsylvania. Before convection enters the picture, it will be another day of record warmth across the Mid-Atlantic region. Using 850-mb temperatures as a proxy, forecast readings should be around 22-23C which dry adiabatic mixing favors another 100 degree day. Adding continued tropical moisture in place will support heat indices pushing into the 105 to 110 degree range. Extreme Heat Warnings are in effect from 10 AM until 9 PM for areas east of the Blue Ridge. Given an uptick in forecast heat indices, have upgraded to warnings over north-central Maryland down across the eastern West Virginia Panhandle into portions of the Shenandoah Valley. Otherwise, outside of mountain locations, Heat Advisories will be in effect until 8 PM this evening. Unlike previous days which were free of convection, a collapsing ridge will lift the subsidence that has persisted the last few days. Although mid/upper heights remain anomalous in nature, forcing from an approaching shortwave will aid in more widespread showers and thunderstorms. One unique aspect to the thermodynamic environment is an elevated mixed layer (EML) which has shown up in the last 4 IAD sounding profiles. Within this layer around 750-600 mb, lapse rates continue to run between 8-9 C/km which is unusually steep for this area. This is contributing to some impressively large amounts of instability, generally in the 3,000 to 4,000 J/kg. Within the deeply mixed boundary layer, substantial downdraft CAPE (DCAPE) is evident with values around 1,300 to 1,700 J/kg. Although vertical shear is only around 20 to 25 knots, any storms able to tap into the robust instability will be capable of damaging winds. Some of this could be locally destructive with gusts up to 60 to 75 mph. With all of the above in mind, and ample high-resolution model support, the Storm Prediction Center has upgraded areas east of the Blue Ridge to an Enhanced Risk today. This upgrade would support a more widespread footprint of severe thunderstorms this afternoon and evening. Looking a bit more closely at today`s setup, convective initiation likely will be more mesoscale in nature. This would include the climatological lee-side trough, bay and river breezes, as well as any remnant outflows from earlier convection. Multiple rounds of thunderstorms are possible given so much instability in the troposphere. The primary signal east of the Blue Ridge is in the 3-9 PM timeframe, slightly earlier to the west. Damaging to locally destructive winds are the main threat, with any chance for large hail being minimal given the summertime freezing levels. Although the convective signal is strongest during the afternoon to early evening hours, residual storms could easily impact those with outdoor plans for fireworks this evening. Continue to check back at weather.gov/lwx or follow the National Weather Service - Baltimore/Washington social media accounts for the latest.

Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0100 AM CDT Sat Jul 04 2026 Valid 041200Z - 051200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS PORTIONS OF THE MID-ATLANTIC... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE CENTRAL/SOUTHERN PLAINS... ...SUMMARY... Clusters of storms will move across parts of the Allegheny Plateau into Mid Atlantic, with potential for widespread damaging wind. Additional thunderstorms are expected across the Great Plains Saturday afternoon and evening, posing a risk for damaging wind gusts. Large hail is also possible across the Great Plains. ...Synopsis... Height rises will continue across the western US, with more zonal flow across the central US and upper-level troughing across the Northeast and Quebec/Ontario. A modest belt of westerly flow around 30-40 kts will move through the trough in the Northeast/Mid-Atlantic. A compact shortwave trough with enhanced westerly flow will move through the flow across the Central Plains. ...Eastern Ohio Valley into the Mid-Atlantic... Activity will likely be ongoing across some portion of northern PA into northern NJ this morning. This will likely contribute to lingering cloud cover and more muted daytime heating/recovery with northern extent. South of the morning precipitation, strong daytime heating and warming is expected, with temperatures climbing into the 90s to 100s F. A plume of steep mid-level lapse rates is already in place across the region from WV into VA/MD/NJ. With daytime heating, low-level lapse rates are expected to increase with moderate to strong instability by the afternoon. Deep layer shear profiles will be generally weak, with better shear to the north. Nonetheless, several thunderstorm clusters are expected to develop across the Blue Ridge Mountains/Shenandoah Valley moving north and eastward though the afternoon. These will have the potential to produce widespread damaging wind, especially if clusters can grow upscale and develop strong cold pools. Additional clusters are likely in the wake of morning convection further north. Instability will be less, but sufficient deep layer shear may support one or more clusters capable of damaging wind.

88/74/96 at 3am at DCA... toasty

Bit of a surprise... ENH and 45 wind up on early morning Day 1

Heat index is 104 lol... I mean its almost midnight

https://wtop.com/traffic/2026/07/portion-of-i-97-in-anne-arundel-co-buckles-under-extreme-heat/ But also https://foxbaltimore.com/news/local/crash-investigation-shuts-down-northbound-i97-friday

Super Typhoon Bavi has arrived with 160 mph winds

Okay, thank you for the explanation. It just seemed weird to have it as an all day thing - but I guess you can't just say AQ will be code purple after 6pm, but before it will be orange

But they dont go off until way late

MDZ013-504-506-050400- Central and Southeast Montgomery-Central and Southeast Howard- Prince Georges- 440 PM EDT Fri Jul 3 2026 ...AIR QUALITY ALERT IS IN EFFECT FOR SATURDAY JULY 4 2026... The Maryland Department of the Environment has issued a Code RED Air Quality Alert Saturday for the Maryland suburban DC region. A Code Red Air Quality Alert means that air pollution concentrations within the region are unhealthy for the general population. The effects of air pollution can be minimized by avoiding strenuous activity or exercise outdoors. For more information on ground-level ozone and fine particles visit the web site mde.maryland.gov/programs/air/AirQualityMonitoring/Pages/index.aspx

Uh what? VAZ053-054-505-506-526-527-050400- Fairfax-Western Loudoun-Eastern Loudoun-Northwest Prince William- Central and Southeast Prince William/Manassas/Manassas Park- Arlington/Falls Church/Alexandria- 440 PM EDT Fri Jul 3 2026 ...AIR QUALITY ALERT IS IN EFFECT FOR SATURDAY JULY 4 2026... The Virginia Department of Environmental Quality has issued a Code PURPLE Air Quality Alert Saturday for Northern Virginia. For more information on ground-level ozone and fine particles visit the web site Virginia DEQ air quality web site at www.deq.virginia.gov DCZ001-050400- District of Columbia- 440 PM EDT Fri Jul 3 2026 ...AIR QUALITY ALERT IS IN EFFECT FOR SATURDAY JULY 4 2026... The Metropolitan Washington Council of Governments and District Department of Environment has issued a Code PURPLE Air Quality Alert Saturday for the District of Columbia. For more information on ground-level ozone and fine particles visit the web site https://www.mwcog.org/environment/air/forecast/

Afternoon AFD from LWX for severe and flood threat Sat to Monday us long and detailed KEY MESSAGE 2...An increased risk for severe thunderstorms through the Independence Day holiday weekend. The Storm Prediction Center outlooks through late Sunday paint the picture of an active convective pattern ahead. A Slight Risk for severe thunderstorms is being advertised across portions of the area during this period. Most of the local area (Mid-Atlantic) should remain capped under upper ridging with forcing displaced to the north. However, any storms that develop to the north may make a run at the I-68/I-70 corridor this evening. Some guidance also attempts to develop an isolated thunderstorm or two along the bay breeze or near the Blue Ridge Mountains. As the upper ridge begins to undergo some weakening, the threat of strong to severe thunderstorms will increase through the holiday weekend. While the guidance shows deep-layered westerlies on Saturday, the flow is on the weaker side which would limit the negative influence of this flow on convective development. The likely triggers for diurnal convection will be around mesoscale boundaries like the lee-side trough, as well as bay and river breezes. Multiple days of intense heat and humidity yields somewhat extreme levels of instability (i.e., mixed layer CAPEs around 3,000 to 4,000 J/kg in some models). With downdraft CAPE values nearing 1,500 J/kg, significant wind damage is not out of the question with more potent updrafts. While difficult to hone in on timing, multiple rounds cannot be ruled given the degree of instability in the atmosphere. A Slight Risk for severe convection remains across the entire region. The updated Day 3/Sunday outlook also brings another Slight Risk day to the local area. A series of weak to modest perturbations in the flow will work in tandem with an approaching nearby frontal system. The position of remnant outflows, degree of convective debris, and additional development are all questions looming for Sunday`s forecast. Despite the uncertainty, the parameters remain favorable for further thunderstorm activity. Additional chances for showers and thunderstorms continue through Tuesday, although the speed at which this weekend`s trough tracks south will be critical for these continued chances to materialize. ML guidance shows an upwards chance in thunderstorm & severe potential for Monday, with NCAR`s Medium-Range AI NWP guidance showing a 30%-45% probability in the 00z guidance for Monday afternoon/evening. Synoptic setup in the days beforehand will be critical in understanding the nature & scope of thunderstorms during this period. Temperatures look to potentially drop as this cold front tracks to the south by early Tuesday, although dewpoints will remain elevated for now resulting in continued humid conditions. Nevertheless, heat indices look to potentially dip back into double digits by Tuesday afternoon in the metros. High pressure moves over the region midweek. KEY MESSAGE 3...Increasing concern for the threat of flash flooding through Monday. Outside of the severe potential over the next few days, which is mentioned in detail above, there is growing concern for a flash flood threat. For Independence Day, the threat is much lower, but still not zero. An extremely moist air mass will be in place over the region, so storms will produce prolific rainfall rates for those that do get them. However, as mentioned above, there is a big concern for damaging downbursts, which should actually mitigate the flash flood threat by keeping storms moving. Urban/poor drainage areas will have an isolated flash flood threat, but it will be very situational, hence the marginal risk for excessive rainfall from WPC over the area. Outside of the metro areas, most locations are still very dry due to the ongoing drought, so the flash flood threat is much lower. By Sunday, things start to get a little more concerning, but especially by Monday. As the upper-level ridge continues to buckle, a trough over the Great Lakes will form with a cold front tracking through the region by Monday. Storms on Sunday are likely to trigger ahead of this front and along existing outflow boundaries from Saturday, terrain circulations, and Bay/River breezes. Storms should generally be progressive, but the threat for training increases if any of these existing boundaries line up parallel to the mean flow. A lot of uncertainty with this, as we have to see how Saturday`s event unfolds first and see what boundaries are left behind in its wake. By Monday though, the slow-moving frontal boundary drops into our region. This front will be very wavy in nature, but some portion seems likely to line up with the mean low-mid level flow, which is out of the WSW. Training convection is much more likely Monday afternoon. Additionally, several days of convection before Monday could reduce the flash-flood guidance, with some areas becoming more susceptible. Either way, the urban areas are the greatest area of concern, as model guidance wants to hang this front up somewhere nearby. With PWATs in excess of 2", skinny CAPE profiles, a deep warm cloud layer, and boundary-parallel low-mid level flow, a lot of ingredients are there for a more widespread flash flooding threat. &&