OceanStWx Posted July 24, 2013 Share Posted July 24, 2013 Five years ago today. This is roughly at the time it touched down near Deerfield. Just 100 knots gate to gate... To my knowledge it is still used as a case study at the Warning Decision Training Branch to teach new met interns and forecasters on the radar. Link to comment Share on other sites More sharing options...
CT Rain Posted July 24, 2013 Share Posted July 24, 2013 NH tornado.png Five years ago today. This is roughly at the time it touched down near Deerfield. Just 100 knots gate to gate... To my knowledge it is still used as a case study at the Warning Decision Training Branch to teach new met interns and forecasters on the radar. 52 miles OTG - pretty incredible storm. http://ryanhanrahan.com/2012/08/18/new-englands-longest-tornado/ Link to comment Share on other sites More sharing options...
OceanStWx Posted July 24, 2013 Share Posted July 24, 2013 52 miles OTG - pretty incredible storm. http://ryanhanrahan.com/2012/08/18/new-englands-longest-tornado/ I think your blog post covers the good and bad quite well. Clearly this wasn't handled as well as it could have been, a la Springfield 2011. Link to comment Share on other sites More sharing options...
CT Rain Posted July 24, 2013 Share Posted July 24, 2013 I think your blog post covers the good and bad quite well. Clearly this wasn't handled as well as it could have been, a la Springfield 2011. Yeah it's easy in retrospect to see how it produced. Shows the importance of situational awareness in these high shear/low cape setups and combining radar analysis with a good idea of the nearby environment. Link to comment Share on other sites More sharing options...
CT Rain Posted July 24, 2013 Share Posted July 24, 2013 I think your blog post covers the good and bad quite well. Clearly this wasn't handled as well as it could have been, a la Springfield 2011. I know we've talked about this before - but dual pol would have been a huge help with this thing. I'm guessing it would have had a TDS for almost its entire time on the ground. Not only would we have had a tornado warning - we also would (hopefully) have a really strongly worded one with radar confirmation. Link to comment Share on other sites More sharing options...
OceanStWx Posted July 24, 2013 Share Posted July 24, 2013 Yeah it's easy in retrospect to see how it produced. Shows the importance of situational awareness in these high shear/low cape setups and combining radar analysis with a good idea of the nearby environment. I think situational awareness is the key phrase there. I think the reaction here (I was on my way to DVN at the time so can't speak in absolutes) was one of "can't be, right?" But when you dig into it (shear, low LCLs, previous day tornado, etc.) it becomes pretty obvious there should have been a warning out prior to the image I posted (which was still 12 minutes before a TOR was issued). Link to comment Share on other sites More sharing options...
CT Rain Posted July 24, 2013 Share Posted July 24, 2013 I think situational awareness is the key phrase there. I think the reaction here (I was on my way to DVN at the time so can't speak in absolutes) was one of "can't be, right?" But when you dig into it (shear, low LCLs, previous day tornado, etc.) it becomes pretty obvious there should have been a warning out prior to the image I posted (which was still 12 minutes before a TOR was issued). Absolutely - and maintaining good situational awareness can be challenging when you have a million other things and tasks that need to be completed in the office. It's also pretty important for forecasters to be really knowledgeable about what setups produce and why in a given area. The shear/super low LCL is an immediate red flag to me this time of year. Link to comment Share on other sites More sharing options...
OceanStWx Posted July 24, 2013 Share Posted July 24, 2013 I know we've talked about this before - but dual pol would have been a huge help with this thing. I'm guessing it would have had a TDS for almost its entire time on the ground. Not only would we have had a tornado warning - we also would (hopefully) have a really strongly worded one with radar confirmation. True story, when I was downloading the level II data this morning for a good image to use for our social media posts I instinctively looked to the right on GR2Analyst and tried to find CC. At the time it touched down near Deerfield the beam was 5500-6000 feet off the ground, and near Ossipee (the second peak in intensity) it was 2500-3000 feet. I think Ossipee would have had a TDS for sure, and given the strength of the couplet near Deerfield it would not surprise if there was one there too. Link to comment Share on other sites More sharing options...
CT Rain Posted July 24, 2013 Share Posted July 24, 2013 True story, when I was downloading the level II data this morning for a good image to use for our social media posts I instinctively looked to the right on GR2Analyst and tried to find CC. At the time it touched down near Deerfield the beam was 5500-6000 feet off the ground, and near Ossipee (the second peak in intensity) it was 2500-3000 feet. I think Ossipee would have had a TDS for sure, and given the strength of the couplet near Deerfield it would not surprise if there was one there too. The fact that it went through such a wooded area - I bet it would loft enough leaf junk to drop CC even at 5kft AGL. Link to comment Share on other sites More sharing options...
OceanStWx Posted July 24, 2013 Share Posted July 24, 2013 Absolutely - and maintaining good situational awareness can be challenging when you have a million other things and tasks that need to be completed in the office. It's also pretty important for forecasters to be really knowledgeable about what setups produce and why in a given area. The shear/super low LCL is an immediate red flag to me this time of year. It was a Thursday, on the day shift. I don't know what the vacation situation was like at the time, but it all likelihood there was enough staff around to handle this event. But if you weren't expecting that kind of weather... I know if that couplet just popped up on my radar screen right now, it would be a frantic several minutes trying to figure out storm scale environment and all that goes into a good warning. Link to comment Share on other sites More sharing options...
OceanStWx Posted July 24, 2013 Share Posted July 24, 2013 Effective shears were running between 40 and 50 knots around the time of the tornado. Effective helicity plots weren't working for me, but 0-1 km and 0-3 km shears were on the order of 200 m2/s2. The second two images are 0-3 km CAPE and vorticity, and SBCAPE. You can see that there was roughly 50-75 J/kg of 0-3 km CAPE, yet only around 250 J/kg SBCAPE. So much of the instability was in the lowest 3 km. Perfect set up for tornadoes to form quickly. Toss in 0-1 km shear of 25 knots or so, and significant tornadoes were also likely. Link to comment Share on other sites More sharing options...
eekuasepinniW Posted July 24, 2013 Share Posted July 24, 2013 2008 was such a great year for storms. That midsummer stormy stretch yielded some of the most visually ominous looking storms I've seen. Need to find my video of rotation that preceded the sudden development of the floodpocalypse storm on August 7th. Link to comment Share on other sites More sharing options...
CT Rain Posted July 24, 2013 Share Posted July 24, 2013 It was a Thursday, on the day shift. I don't know what the vacation situation was like at the time, but it all likelihood there was enough staff around to handle this event. But if you weren't expecting that kind of weather... I know if that couplet just popped up on my radar screen right now, it would be a frantic several minutes trying to figure out storm scale environment and all that goes into a good warning. Oh no doubt... and they did launch at 17z balloon that day so I think they were expecting some severe. With 2008 and 2011 in mind the NWS hasn't exactly done a stellar job on sig tornadoes in New England but stuff happens and we all learn and I'm willing to be neither warning-lapses will happen again. Link to comment Share on other sites More sharing options...
CT Rain Posted July 24, 2013 Share Posted July 24, 2013 2008 was such a great year for storms. That midsummer stormy stretch yielded some of the most visually ominous looking storms I've seen. Need to find my video of rotation that preceded the sudden development of the floodpocalypse storm on August 7th. Anything is better than 2013. This year has just been horrible for severe. Link to comment Share on other sites More sharing options...
Bostonseminole Posted July 24, 2013 Share Posted July 24, 2013 52 miles OTG - pretty incredible storm. http://ryanhanrahan.com/2012/08/18/new-englands-longest-tornado/ Nice read Ryan, thanks for posting. Link to comment Share on other sites More sharing options...
OceanStWx Posted July 24, 2013 Share Posted July 24, 2013 Oh no doubt... and they did launch at 17z balloon that day so I think they were expecting some severe. With 2008 and 2011 in mind the NWS hasn't exactly done a stellar job on sig tornadoes in New England but stuff happens and we all learn and I'm willing to be neither warning-lapses will happen again. I think this office learned quite a bit that day. I also think it points to training. Much of what is focused on when you enter the NWS is classic supercell structure on the radar. 2011 qualifies there, but 2008 in NH was nothing like a classic supercell, and I would say the majority of New England tornadoes fall into a similar category. Link to comment Share on other sites More sharing options...
SJonesWX Posted July 24, 2013 Share Posted July 24, 2013 NH tornado.png Five years ago today. This is roughly at the time it touched down near Deerfield. Just 100 knots gate to gate... To my knowledge it is still used as a case study at the Warning Decision Training Branch to teach new met interns and forecasters on the radar. amazing to me how close this was to hitting some pretty populated areas. if that had touched down 10-15 miles to the west, there would have been significant damage and obviously quite a bit more human problems Link to comment Share on other sites More sharing options...
OceanStWx Posted July 24, 2013 Share Posted July 24, 2013 NNE summer, temps dropping behind a cold front in the middle of the day in July. Refreshing. Link to comment Share on other sites More sharing options...
dendrite Posted July 24, 2013 Share Posted July 24, 2013 That tornado nearly missed my coworker's home in Barnstead. His babysitter was at his house watching his daughter. I remember looking at the velocity scans and telling him to call her to take cover. Impressive for NH. Link to comment Share on other sites More sharing options...
mreaves Posted July 24, 2013 Share Posted July 24, 2013 NNE summer, temps dropping behind a cold front in the middle of the day in July. Refreshing. SLK 52°/48° as of 11:00 a.m. Link to comment Share on other sites More sharing options...
powderfreak Posted July 24, 2013 Share Posted July 24, 2013 NNE summer, temps dropping behind a cold front in the middle of the day in July. Refreshing. Yeah it is 63F here and hasn't gone anywhere at all today... been sitting low 60s all morning, while the dews continue to drop. Link to comment Share on other sites More sharing options...
OceanStWx Posted July 24, 2013 Share Posted July 24, 2013 Speaking of the tornado, our Hollings Scholar intern just gave her presentation of the last couple of months of research. She did the second half of a study started two years ago about tornadic events in New England. This was researching non-tornadic events by examining all the various severe weather parameters over 61 days with 12 or more severe events (but no tornadoes) in all of the New England domain. What she found, the most predictive parameters were LCL height, 0-1 km SRH, and 0-3 km SRH. Low values or SRH and high LCLs separated the tornadic days from the non-tornadic ones. She also found that the shear overlapped similar values, but CAPE was much higher in non-tornadic cases. I thought it was fitting because in 2008 we saw low CAPE, high shear, high SRH, and low LCLs. Screams New England tornadic event based on these two studies. Link to comment Share on other sites More sharing options...
dryslot Posted July 24, 2013 Share Posted July 24, 2013 Fook........ Link to comment Share on other sites More sharing options...
CT Rain Posted July 24, 2013 Share Posted July 24, 2013 Speaking of the tornado, our Hollings Scholar intern just gave her presentation of the last couple of months of research. She did the second half of a study started two years ago about tornadic events in New England. This was researching non-tornadic events by examining all the various severe weather parameters over 61 days with 12 or more severe events (but no tornadoes) in all of the New England domain. What she found, the most predictive parameters were LCL height, 0-1 km SRH, and 0-3 km SRH. Low values or SRH and high LCLs separated the tornadic days from the non-tornadic ones. She also found that the shear overlapped similar values, but CAPE was much higher in non-tornadic cases. I thought it was fitting because in 2008 we saw low CAPE, high shear, high SRH, and low LCLs. Screams New England tornadic event based on these two studies. Not surprised at all. It seems to me there are 2 distinct type of New England tornado days... the rare classic supercellular days (like 6/1/11) and the more frequent low LCL/high shear/low CAPE days. I bet if you were to break the latter down even further you'd find LCLs are ridiculously low in the near-storm environment for the tornadic low cape/high shear days. I'm talking on the order of 300-400 meters in some cases. Link to comment Share on other sites More sharing options...
Allenson Posted July 24, 2013 Share Posted July 24, 2013 1.46" with the rains from Monday night/yesterday morning. Up to 7.34" for July. Dews dropping and feeling much nicer out there again. I'd love to see an end to the Great Rot of 2013. I know other areas have been drier but the funk here has been relentless.... Link to comment Share on other sites More sharing options...
OceanStWx Posted July 24, 2013 Share Posted July 24, 2013 Not surprised at all. It seems to me there are 2 distinct type of New England tornado days... the rare classic supercellular days (like 6/1/11) and the more frequent low LCL/high shear/low CAPE days. I bet if you were to break the latter down even further you'd find LCLs are ridiculously low in the near-storm environment for the tornadic low cape/high shear days. I'm talking on the order of 300-400 meters in some cases. 2011 is definitely an outlier high shear/high CAPE day. I think it was ALY or BTV that chimed in to hypothesize that on those big CAPE days you need a lot of sun which in turn raises LCL heights. The study found LCLs median value was around 2000 feet, as opposed to 5000 feet for non-tornadic days. Link to comment Share on other sites More sharing options...
Lava Rock Posted July 24, 2013 Share Posted July 24, 2013 Nice 1/4" in the shower that moved through Link to comment Share on other sites More sharing options...
Nittany88 Posted July 24, 2013 Share Posted July 24, 2013 Well today sucks. Link to comment Share on other sites More sharing options...
powderfreak Posted July 24, 2013 Share Posted July 24, 2013 Well today sucks. I was waiting for that. Late-September climo for daytime highs? The high at SLK since like 12z looks like 54F on the hourlies. I have been anywhere from 61-64F depending on cloud cover today...but holding in the low 60s in that 500-1000ft elevation band is impressive for July. Even BTV won't get out of the 60s during the daytime. Wet-bulb temps are like upper 40s in the Dacks to upper 50s in VT...autumn like. Link to comment Share on other sites More sharing options...
Allenson Posted July 24, 2013 Share Posted July 24, 2013 Well today sucks. Huh? This is just what I've been waiting for. Link to comment Share on other sites More sharing options...
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