weatherwiz Posted April 19, 2021 Share Posted April 19, 2021 A nice little "pre-game" before severe weather season kicks in but looks like we'll see a low topped squall line move across much of southern New England late Wednesday afternoon and early evening. While the greatest threat for damaging wind gusts likely exists to our west (across NY and northern PA) the potential will exist for much of the region for localized embedded damaging wind gusts and perhaps even some small hail. Instability is not the driver in this event as instability will be quite marginal with temperatures only into the 60's and dewpoints in the 40's to 50's, however, the presence of steep mid-level lapse rates aloft results in modest instability (500 - 750 J/KG of MLCAPE). The driver here is strong forcing from the approaching cold front and very strong jet dynamics characterized by 50-60+ knots at 500mb and 35-40+ knots at 850mb. Fairly steep low-level lapse rates, low-level dry air, and strong LLJ will also favor embedded damaging wind gusts, likely on the leading edge of the line. With steep mid-level lapse rates and cold air aloft, small hail is also possible. 5 Link to comment Share on other sites More sharing options...
crossbowftw3 Posted April 20, 2021 Share Posted April 20, 2021 On 4/19/2021 at 10:06 PM, weatherwiz said: A nice little "pre-game" before severe weather season kicks in but looks like we'll see a low topped squall line move across much of southern New England late Wednesday afternoon and early evening. While the greatest threat for damaging wind gusts likely exists to our west (across NY and northern PA) the potential will exist for much of the region for localized embedded damaging wind gusts and perhaps even some small hail. Instability is not the driver in this event as instability will be quite marginal with temperatures only into the 60's and dewpoints in the 40's to 50's, however, the presence of steep mid-level lapse rates aloft results in modest instability (500 - 750 J/KG of MLCAPE). The driver here is strong forcing from the approaching cold front and very strong jet dynamics characterized by 50-60+ knots at 500mb and 35-40+ knots at 850mb. Fairly steep low-level lapse rates, low-level dry air, and strong LLJ will also favor embedded damaging wind gusts, likely on the leading edge of the line. With steep mid-level lapse rates and cold air aloft, small hail is also possible. Expand Perfectly timed too as it looks like the grander pattern implies severe weather season across the eastern 2/3rds of America looks primed to really kick off starting this weekend. Link to comment Share on other sites More sharing options...
radiator Posted April 20, 2021 Share Posted April 20, 2021 Interestingly, the WX Underground forecast for NW CT shows chance of thunderstorms on Wed for each hour from 8 AM through 2 PM, which seems to be a bit earlier than the late Wednesday afternoon and early evening "pre-game" show timing mentioned above. Link to comment Share on other sites More sharing options...
weatherwiz Posted April 20, 2021 Author Share Posted April 20, 2021 On 4/20/2021 at 7:21 PM, radiator said: Interestingly, the WX Underground forecast for NW CT shows chance of thunderstorms on Wed for each hour from 8 AM through 2 PM, which seems to be a bit earlier than the late Wednesday afternoon and early evening "pre-game" show timing mentioned above. Expand eh those hourly things are kinda crap 2 Link to comment Share on other sites More sharing options...
Brian5671 Posted April 20, 2021 Share Posted April 20, 2021 On 4/20/2021 at 7:21 PM, radiator said: Interestingly, the WX Underground forecast for NW CT shows chance of thunderstorms on Wed for each hour from 8 AM through 2 PM, which seems to be a bit earlier than the late Wednesday afternoon and early evening "pre-game" show timing mentioned above. Expand 8AM? Bust. No model has anything that early 1 Link to comment Share on other sites More sharing options...
weatherwiz Posted April 21, 2021 Author Share Posted April 21, 2021 HRRR pretty bullish with a few decent UD swaths...not likely but certainly room for a brief tornado as well today 1 Link to comment Share on other sites More sharing options...
HoarfrostHubb Posted April 21, 2021 Share Posted April 21, 2021 Mid to late afternoon could be fun Link to comment Share on other sites More sharing options...
Ginx snewx Posted April 21, 2021 Share Posted April 21, 2021 On 4/21/2021 at 11:53 AM, weatherwiz said: HRRR pretty bullish with a few decent UD swaths...not likely but certainly room for a brief tornado as well today Expand 2010 May 5th? Link to comment Share on other sites More sharing options...
ineedsnow Posted April 21, 2021 Share Posted April 21, 2021 Cumulus clouds this morning.. Unstable already? Link to comment Share on other sites More sharing options...
CoastalWx Posted April 21, 2021 Share Posted April 21, 2021 HRRR seems to overdo it at times. 3k NAM not as excited, but I do think a few strong storms into wrn CT/MA/srn VT possible. HRRR has shown a bow into the Berks. Link to comment Share on other sites More sharing options...
CoastalWx Posted April 21, 2021 Share Posted April 21, 2021 Good lapse rates aloft. Link to comment Share on other sites More sharing options...
Chrisrotary12 Posted April 21, 2021 Share Posted April 21, 2021 Ok. Consider me slightly intrigued. Link to comment Share on other sites More sharing options...
weatherwiz Posted April 21, 2021 Author Share Posted April 21, 2021 On 4/21/2021 at 12:05 PM, Ginx snewx said: 2010 May 5th? Expand let's do it! Link to comment Share on other sites More sharing options...
weatherwiz Posted April 21, 2021 Author Share Posted April 21, 2021 On 4/21/2021 at 12:27 PM, CoastalWx said: HRRR seems to overdo it at times. 3k NAM not as excited, but I do think a few strong storms into wrn CT/MA/srn VT possible. HRRR has shown a bow into the Berks. Expand Yeah the HRRR has been pretty consistent with that bowing feature. Also want to add something for folks but this is a situation where the strongest winds are going to be on the leading edge of the line. It will still be gusty under the rain but the rain-cooled air will quickly reduce winds. This is for those who "meh" things when under the line Link to comment Share on other sites More sharing options...
WxWatcher007 Posted April 21, 2021 Share Posted April 21, 2021 Latest NAM looked decent for some storms in CT, especially in western CT. Sounding looked alright for the Hartford area. Would prefer more DCAPE but hopefully I can get some good pics today. Link to comment Share on other sites More sharing options...
Cyclone-68 Posted April 21, 2021 Share Posted April 21, 2021 I’ll be disappointed with anything less than a TORCON 7 this summer Link to comment Share on other sites More sharing options...
WxWatcher007 Posted April 21, 2021 Share Posted April 21, 2021 On 4/21/2021 at 2:46 PM, Cyclone-68 said: I’ll be disappointed with anything less than a TORCON 7 this summer Expand In Kansas? Link to comment Share on other sites More sharing options...
Cyclone-68 Posted April 21, 2021 Share Posted April 21, 2021 On 4/21/2021 at 2:47 PM, WxWatcher007 said: In Kansas? Expand You are observant I didn’t actually say where lol 1 Link to comment Share on other sites More sharing options...
crossbowftw3 Posted April 21, 2021 Share Posted April 21, 2021 On 4/21/2021 at 2:47 PM, WxWatcher007 said: In Kansas? Expand if the upcoming large scale pattern is to be believed you may see that happen in KS/OK....on the 10th anniversary of 4/27/11 no less Link to comment Share on other sites More sharing options...
WxWatcher007 Posted April 21, 2021 Share Posted April 21, 2021 Probably irrelevant, but I didn't expect it to be this breezy. My VP2 gusted to 24mph which is pretty decent given how it is sited. Link to comment Share on other sites More sharing options...
HoarfrostHubb Posted April 21, 2021 Share Posted April 21, 2021 A few flakes possible tonight? Link to comment Share on other sites More sharing options...
weatherwiz Posted April 21, 2021 Author Share Posted April 21, 2021 On 4/21/2021 at 3:15 PM, HoarfrostHubb said: A few flakes possible tonight? Expand could see some squalls maybe tomorrow (perhaps moreso NYS, VT, and western MA) Link to comment Share on other sites More sharing options...
weatherwiz Posted April 21, 2021 Author Share Posted April 21, 2021 On 4/21/2021 at 3:11 PM, WxWatcher007 said: Probably irrelevant, but I didn't expect it to be this breezy. My VP2 gusted to 24mph which is pretty decent given how it is sited. Expand Pretty steep llvl lapse rates and strong llvl shear FTW 1 Link to comment Share on other sites More sharing options...
Hoth Posted April 21, 2021 Share Posted April 21, 2021 Nice mammatus with this departing storm. Torrential rain and a few lightning strikes on Stein's grave. 1 Link to comment Share on other sites More sharing options...
weatherwiz Posted April 21, 2021 Author Share Posted April 21, 2021 good sign to see some lightning with this initial activity. Link to comment Share on other sites More sharing options...
WxWatcher007 Posted April 21, 2021 Share Posted April 21, 2021 On 4/21/2021 at 3:48 PM, weatherwiz said: good sign to see some lightning with this initial activity. Expand Yeah, that stuff moving into northern Hartford County looks pretty decent. Link to comment Share on other sites More sharing options...
weatherwiz Posted April 21, 2021 Author Share Posted April 21, 2021 On 4/21/2021 at 3:50 PM, WxWatcher007 said: Yeah, that stuff moving into northern Hartford County looks pretty decent. Expand Just had a pretty decent gust of wind here (Windsor Locks). Looks like bulk of the line passes just north Link to comment Share on other sites More sharing options...
Cyclone-68 Posted April 21, 2021 Share Posted April 21, 2021 Interesting just to see thunderstorms in the region before noon in late April Link to comment Share on other sites More sharing options...
WxWatcher007 Posted April 21, 2021 Share Posted April 21, 2021 I’m clearly bored Mesoscale Discussion 0402 NWS Storm Prediction Center Norman OK 1049 AM CDT Wed Apr 21 2021 Areas affected...Western MA...NY Hudson Valley...Western/Central Long Island...Western CT...NJ Concerning...Severe potential...Watch possible Valid 211549Z - 211815Z Probability of Watch Issuance...60 percent SUMMARY...Thunderstorm development is anticipated over the next hour or two along a cold front progressing through the Northeast. Damaging wind gusts are possible with these storms and trends are being monitored for possible Severe Thunderstorm Watch issuance. DISCUSSION...Recent surface analysis places a low near the NY/NJ/PA border intersection. A warm front extends eastward/northeastward from this low across southern NY through western MA and off the far southern ME coast. This low is embedded within a broad area of low pressure preceding a strong frontal surge attendant to a shortwave moving into western PA/NY. This low is expected to deepen over the next few hours ahead of the front while the warm front lifts northward. As a result, temperatures in the low to mid 60s will likely be in place ahead of the front from western MA through central NJ. Low-level moisture will be modest (i.e. in upper 40s/low 50s) but the steep low and mid-level lapse rates will foster modest buoyancy. Expectation is that deeper convection will begin developing along the front during the next hour or two before then moving quickly eastward across the region. Previously mentioned steep low-level lapse rates coupled with deep convection and strengthening low to mid-level flow will result in the potential for damaging wind gusts as the storms move through. Storm coverage may be high enough to merit watch issuance and convective trends are being monitored closely. ..Mosier/Guyer.. 04/21/2021 Link to comment Share on other sites More sharing options...
crossbowftw3 Posted April 21, 2021 Share Posted April 21, 2021 hearing some rumbles here in the Catskills, should be interesting for you guys once this thing really gets rolling. Link to comment Share on other sites More sharing options...
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