frd Posted Sunday at 10:56 PM Share Posted Sunday at 10:56 PM https://x.com/TonyPannWBAL/status/2071349776344351200 Tony Pann @TonyPannWBAL Big Boomers over the top of the Heat Dome later this week? Below you'll see a plot of the "K Index" from the Canadian GDPS. It's a measure of T-Storm potential. Anything 40+ is good. You can see the bullseye (red) on Thursday is well North of MD. By Friday, that 40+ zone sinks into MD. Stay tuned... Link to comment Share on other sites More sharing options...
vortex95 Posted Sunday at 11:19 PM Share Posted Sunday at 11:19 PM 23 hours ago, frd said: https://x.com/TonyPannWBAL/status/2071349776344351200 Tony Pann @TonyPannWBAL Big Boomers over the top of the Heat Dome later this week? Below you'll see a plot of the "K Index" from the Canadian GDPS. It's a measure of T-Storm potential. Anything 40+ is good. You can see the bullseye (red) on Thursday is well North of MD. By Friday, that 40+ zone sinks into MD. Stay tuned... The issue on Friday is that the ridging aloft is still almost right over us w/ very warm 700 mb temps. This is not conducive for convective development as things are capped. Any storms that manage to develop will just collapse on themselves due to very light winds aloft. Sat and after is better for tstms here. You can't treat a single convective parameter in a vacuum and run w/ that. Other things have to be present for tstms to develop and sustain. Using the K-index like this is like saying b/c there is a lot of CAPE, that means there will storms. Many days there is lots of CAPE, and nothing happens for various reasons. For the K-index itself, it is probably best for forecasting heavy rainfall potential as it indicates a solid moist vertical profile 700 mb and below. Also, an axis of higher indices often indicates a boundary present that may not show up on other analyses. K-index though in a solid svr wx environment often is low owning to dry air at mid-levels. Dry air at mid-levels actually tends to be better for svr wx overall as it can mean an EML is present. 5 1 1 Link to comment Share on other sites More sharing options...
frd Posted Sunday at 11:38 PM Share Posted Sunday at 11:38 PM 18 minutes ago, vortex95 said: The issue on Friday is that the ridging aloft is still almost right over us w/ very warm 700 mb temps. This is not conducive for convective development as things are capped. Any storms that manage to develop will just collapse on themselves due to very light winds aloft. Sat and after is better for tstms here. You can't treat a single convective parameter in a vacuum and run w/ that. Other things have to be present for tstms to develop and sustain. Using the K-index like this is like saying b/c there is a lot of CAPE, that means there will storms. Many days there is lots of CAPE, and nothing happens for various reasons. For the K-index itself, it is probably best for forecasting heavy rainfall potential as it indicates a solid moist vertical profile 700 mb and below. Also. an axis of higher indices often indicates a boundary present that may not show up on other analyses. K-index though in a solid svr wx environment often is low owning to dry air at mid-levels. Dry air at mid-levels actually tends to be better for svr wx overall as it can mean an EML is present. Thank you we'll have to keep an eye beginning on Saturday then I imagine Link to comment Share on other sites More sharing options...
SnowenOutThere Posted Monday at 03:11 AM Share Posted Monday at 03:11 AM 3 hours ago, vortex95 said: The issue on Friday is that the ridging aloft is still almost right over us w/ very warm 700 mb temps. This is not conducive for convective development as things are capped. Any storms that manage to develop will just collapse on themselves due to very light winds aloft. Sat and after is better for tstms here. You can't treat a single convective parameter in a vacuum and run w/ that. Other things have to be present for tstms to develop and sustain. Using the K-index like this is like saying b/c there is a lot of CAPE, that means there will storms. Many days there is lots of CAPE, and nothing happens for various reasons. For the K-index itself, it is probably best for forecasting heavy rainfall potential as it indicates a solid moist vertical profile 700 mb and below. Also. an axis of higher indices often indicates a boundary present that may not show up on other analyses. K-index though in a solid svr wx environment often is low owning to dry air at mid-levels. Dry air at mid-levels actually tends to be better for svr wx overall as it can mean an EML is present. I’m traveling up to north central PA Saturday for a family Fourth of July. Think they might see storms? Link to comment Share on other sites More sharing options...
Pityflakes Posted Monday at 04:13 PM Share Posted Monday at 04:13 PM Pattern change heralding derecho around 7/10? GFS has had the idea for a few runs now Link to comment Share on other sites More sharing options...
JenkinsJinkies Posted Monday at 06:21 PM Share Posted Monday at 06:21 PM 2 hours ago, Pityflakes said: Pattern change heralding derecho around 7/10? GFS has had the idea for a few runs now The 2012 one was preceded by a heatwave similar to the one we're heading into. Link to comment Share on other sites More sharing options...
frd Posted Monday at 11:47 PM Share Posted Monday at 11:47 PM On 6/28/2026 at 7:19 PM, vortex95 said: Sat and after is better for tstms here. https://x.com/TylerSebreezy/status/2071380465630490940 The NSSL machine-learning severe probabilities show the classic "ring of fire" setup over the next 10+ days around our heat dome. The Northern Plains to the East Coast will have ingredients in place to support intense thunderstorm clusters/complexes and an MCS threat. Link to comment Share on other sites More sharing options...
vortex95 Posted Tuesday at 02:49 AM Share Posted Tuesday at 02:49 AM 3 hours ago, frd said: https://x.com/TylerSebreezy/status/2071380465630490940 The NSSL machine-learning severe probabilities show the classic "ring of fire" setup over the next 10+ days around our heat dome. The Northern Plains to the East Coast will have ingredients in place to support intense thunderstorm clusters/complexes and an MCS threat. Yes, starting on Sat, it looks quite good for tstms in the Mid-Atlantic! Give us some good training soakers as we need the rain badly. 1 1 Link to comment Share on other sites More sharing options...
frd Posted Tuesday at 03:30 PM Share Posted Tuesday at 03:30 PM Blah.......ring of nothing Link to comment Share on other sites More sharing options...
Eskimo Joe Posted Tuesday at 04:25 PM Share Posted Tuesday at 04:25 PM If we don't get some storms when this ridge breaks down a bit, then we're setting ourselves up for a very hot July. Link to comment Share on other sites More sharing options...
SolidIcewx Posted Tuesday at 05:52 PM Share Posted Tuesday at 05:52 PM 1 hour ago, Eskimo Joe said: If we don't get some storms when this ridge breaks down a bit, then we're setting ourselves up for a very hot July. Makes me sad knowing Sudbury Ontario is getting better MCV’s than us all the way down here Link to comment Share on other sites More sharing options...
frd Posted Tuesday at 07:54 PM Share Posted Tuesday at 07:54 PM Mount Holly has removed all mentions of storms here on the 4 th , previously was up to 30 % probs. Tonight A slight chance of showers after 3am. Partly cloudy, with a low around 69. Southwest wind 5 to 10 mph, with gusts as high as 20 mph. Chance of precipitation is 20%. Wednesday Mostly sunny, with a high near 96. Heat index values as high as 102. Southwest wind around 10 mph. Wednesday Night A slight chance of showers and thunderstorms before midnight. Mostly clear, with a low around 74. South wind 5 to 10 mph. Chance of precipitation is 20%. Thursday Sunny and hot, with a high near 99. Heat index values as high as 105. West wind 5 to 10 mph. Thursday Night Mostly clear, with a low around 78. Southwest wind 5 to 10 mph. Friday Sunny and hot, with a high near 102. Friday Night Partly cloudy, with a low around 77. Independence Day Mostly sunny and hot, with a high near 99. Saturday Night A chance of showers and thunderstorms between 8pm and 2am. Mostly cloudy, with a low around 74. Chance of precipitation is 40%. Sunday A chance of showers and thunderstorms after 2pm. Partly sunny, with a high near 93. Chance of precipitation is 40%. Sunday Night Showers and thunderstorms likely. Mostly cloudy, with a low around 71. Chance of precipitation is 60%. Monday A chance of showers and thunderstorms. Partly sunny, with a high near 87. Chance of precipitation is 50%. Monday Night A chance of showers and thunderstorms. Mostly cloudy, with a low around 70. Chance of precipitation is 30%. Tuesday A chance of showers. Mostly sunny, with a high near 87. Chance of precipitation is 30%. Link to comment Share on other sites More sharing options...
WxUnit Posted Wednesday at 07:45 PM Share Posted Wednesday at 07:45 PM SPC mentions both Friday and Saturday have very similar severe setups. A slight risk was added to the northern areas in the new Day 3 outlook with higher potential mentioned as well. Link to comment Share on other sites More sharing options...
vortex95 Posted yesterday at 09:01 AM Share Posted yesterday at 09:01 AM Despite the MRGL/SLGHT risk SPC has for the region Fri, it still looks to me too warm aloft and capped for any significant storms most of the region. Still +12 C at 700 most of the day. The ridging aloft starts to break down by late aftn, but models show very limited storm coverage. Isolated storms at best. Best chance the PA border and SW VA/parts of WV. Looks good for considerable tstm activity Sat-Mon. GFS and ECMWF quite wet for the region in the next week. 5 1 Link to comment Share on other sites More sharing options...
dailylurker Posted yesterday at 03:19 PM Share Posted yesterday at 03:19 PM Justin Berk is honking on a flood threat for Sunday and Monday. 1 1 Link to comment Share on other sites More sharing options...
frd Posted yesterday at 03:27 PM Share Posted yesterday at 03:27 PM 6 minutes ago, dailylurker said: Justin Berk is honking on a flood threat for Sunday and Monday. Extreme heat events such as this one, with tropical moisture, have a decent potential of ending with a bang. 1 Link to comment Share on other sites More sharing options...
yoda Posted yesterday at 07:25 PM Share Posted yesterday at 07:25 PM Day 3 and 4 SLGT up 2 Link to comment Share on other sites More sharing options...
Kmlwx Posted yesterday at 07:26 PM Author Share Posted yesterday at 07:26 PM NCAR (always bullish) is VERY bullish for Saturday. CSU is pretty bullish for Saturday as well. I'm not at all in for any threat tomorrow. I think Sat/Sun could feature a substantial damaging wind threat IF there is a trigger and if storms can grow upscale (not just pulse, isolated crap) 3 Link to comment Share on other sites More sharing options...
Kmlwx Posted yesterday at 07:35 PM Author Share Posted yesterday at 07:35 PM Also the NAM seems to not do much Saturday but does have a major complex into the area Sun evening. GFS seems to like both days (severe TBD). 3 Link to comment Share on other sites More sharing options...
vortex95 Posted 17 hours ago Share Posted 17 hours ago 7 hours ago, Kmlwx said: NCAR (always bullish) is VERY bullish for Saturday. CSU is pretty bullish for Saturday as well. I'm not at all in for any threat tomorrow. I think Sat/Sun could feature a substantial damaging wind threat IF there is a trigger and if storms can grow upscale (not just pulse, isolated crap) 18z GFS has a 5" max right near DC ending 12z Tue. We sure need it! ECMWF likes PHL-NYC for the big QPF max. Either way, should be a solid 3 day active period Sat-Mon. Link to comment Share on other sites More sharing options...
high risk Posted 16 hours ago Share Posted 16 hours ago While Friday is indeed capped with no real trigger, there are a couple of CAMs that have a complex of storms dropping south out of PA during the early evening and initiating new storms in our area on the outflow. That said, I'm certainly on board with the prevailing idea of better chances of storms Saturday-Monday with severe and flash flood threats. 5 Link to comment Share on other sites More sharing options...
WxUSAF Posted 9 hours ago Share Posted 9 hours ago Euro, NAM, and FV3 meso bring a weakening line of storms through the whole metro area this evening. 4 1 1 Link to comment Share on other sites More sharing options...
frd Posted 3 hours ago Share Posted 3 hours ago https://x.com/TylerSebreezy/status/2073064609636880472 @TylerSebreezy Here's the latest NSSL machine-learning severe probabilities for the next 2 weeks. Definitely showing some high numbers over the next few days as the "heat dome" pattern supplies ample heat, moisture and instability. Link to comment Share on other sites More sharing options...
frd Posted 3 hours ago Share Posted 3 hours ago https://x.com/ryankanerWX/status/2073032905203253524 @ryankanerWX RRFS says we break through the capping & storms break out, especially across southern PA & northern MD. HRRR says we stay capped. Good test for the RRFS which will be the new main mesoscale model beginning on the last day of August (replacing the NAM). #MdWx Link to comment Share on other sites More sharing options...
yoda Posted 2 hours ago Share Posted 2 hours ago 30 wind added for tomorrow on 1730z day 2 SPC OTLK Link to comment Share on other sites More sharing options...
dailylurker Posted 2 hours ago Share Posted 2 hours ago 44 minutes ago, frd said: https://x.com/ryankanerWX/status/2073032905203253524 @ryankanerWX RRFS says we break through the capping & storms break out, especially across southern PA & northern MD. HRRR says we stay capped. Good test for the RRFS which will be the new main mesoscale model beginning on the last day of August (replacing the NAM). #MdWx Justin Berk has been using it and posting forecast from it. It's been horrible. Hopefully it improves before Aug. 1 Link to comment Share on other sites More sharing options...
yoda Posted 1 hour ago Share Posted 1 hour ago Watch up for N and NE MD until 11pm 1 Link to comment Share on other sites More sharing options...
frd Posted 1 hour ago Share Posted 1 hour ago SEVERE THUNDERSTORM WATCH OUTLINE UPDATE FOR WS 448 NWS STORM PREDICTION CENTER NORMAN OK 325 PM EDT FRI JUL 3 2026 SEVERE THUNDERSTORM WATCH 448 IS IN EFFECT UNTIL 1100 PM EDT FOR THE FOLLOWING LOCATIONS DEC003-040300- /O.NEW.KWNS.SV.A.0448.260703T1925Z-260704T0300Z/ DE . DELAWARE COUNTIES INCLUDED ARE NEW CASTLE $$ Link to comment Share on other sites More sharing options...
yoda Posted 1 hour ago Share Posted 1 hour ago URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 448 NWS Storm Prediction Center Norman OK 325 PM EDT Fri Jul 3 2026 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Northern Delaware Northeast Maryland New Jersey Southern New York Central and Eastern Pennsylvania Coastal Waters * Effective this Friday afternoon and evening from 325 PM until 1100 PM EDT. * Primary threats include... Scattered damaging wind gusts to 70 mph likely SUMMARY...Thunderstorms are intensifying over southern New York and northern Pennsylvania in a hot/humid air mass. These storms will track southeastward through the afternoon and early evening, posing a risk of locally damaging wind gusts. Link to comment Share on other sites More sharing options...
high risk Posted 1 hour ago Share Posted 1 hour ago Wasn't expecting the box to come that far south, but as noted above, there is at least some cam support for it. Also, RRFS going operational is delayed until October. Link to comment Share on other sites More sharing options...
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