weatherwiz Posted October 23, 2017 Share Posted October 23, 2017 Intriguing setup for tomorrow which computer forecast models have been quite consistent on for the past week. A rather potent upper-level trough which will continue to amplify as it progresses through the Ohio Valley will push a strong cold front eastward. Very strong dynamics associated with this system, characterized by a 90+ knot 500mb MLJ streak in which we should end up in the RFQ. With an anomalously warm and moist low-level airmass this should yield several hundred J of CAPE, even persisting well into the overnight hours. The combination of modest CAPE, strong wind shear, and strong forcing will all contribute to perhaps multiple rounds of convection tomorrow with activity possible in the afternoon hours then again later in the evening. The potential will exist for strong to damaging wind gusts in stronger convection. Given the large hodographs as well we will have to watch for rotation. It's also interesting how some of the hi-res guidance actually develops some discrete activity which usually doesn't happen much in these setups. Link to comment Share on other sites More sharing options...
Damage In Tolland Posted October 23, 2017 Share Posted October 23, 2017 Synoptic wind gusts to 60 are what’s most likely and intriguing. Stuff is going to come the hell down Link to comment Share on other sites More sharing options...
HoarfrostHubb Posted October 23, 2017 Share Posted October 23, 2017 Tue night and Wed... Synoptic Overview... Slow moving cold front becomes parallel to upper flow as mid level trough takes on negative tilt. This front will be associated with an impressive warm conveyor belt up the eastern seaboard containing subtropical moisture with PWATs near the 2.00 inch mark, or nearly 3 std deviations above normal. Also embedded within this warm conveyor belt is very strong wind anomalies with 925 mb wind speeds of 55-65 kts, +4 std deviations above climo! This low level jet builds a low level thermal anomaly with nearly moist adiabatic lapse rates above this warm anomaly. This very strong low level jet also advects surface dew pts into the mid and upper 60s across southern New England late Tue into early Wed, generating MUcapes of 300-500 j/kg, very impressive for late Oct. Wind risk... As mentioned above low level jet peaks at about 55-65 kt late Tue into early Wed. Heavier showers (via precip drag) and especially potential low top fine line (very strong frontal convergence coupled with marginal instability) across western MA/CT will increase the risk for stronger winds aloft mixing to the surface. Given leaves remain on most trees, this will exacerbate the risk for downed limbs or even some trees with localized power outages. Wind headlines will likely be needed as we draw closer to the event. Heavy rain... Subtropical moisture streams up the eastern seaboard with PWATs nearing 2 inches, +4 std deviations from climo for about 24-30 hrs! This duration coupled with strong frontal forcing and marginal instability should be sufficient for periods of heavy showers with isolated thunder possible. Much of the global guidance offering a widespread 1-2" rainfall amounts with localized 3-5" possible especially eastern NY into western MA/CT given greater risk of low top fine line. Link to comment Share on other sites More sharing options...
wxeyeNH Posted October 23, 2017 Share Posted October 23, 2017 Wind advisories, high wind watches forthcoming? Trees in leaf still cause more disruption. Link to comment Share on other sites More sharing options...
RUNNAWAYICEBERG Posted October 23, 2017 Share Posted October 23, 2017 Nice way to bust the drought. Flood it and tear some limbs down. Link to comment Share on other sites More sharing options...
weatherwiz Posted October 23, 2017 Author Share Posted October 23, 2017 Tomorrow's cold front sort of arrives from the WSW? Isn't there some type of connection between enhanced severe wx risk from fronts which arrive in this direction as opposed to fronts which arrive from the west or northwest? Link to comment Share on other sites More sharing options...
Hoth Posted October 23, 2017 Share Posted October 23, 2017 No high wind warning? Yawn. Link to comment Share on other sites More sharing options...
eekuasepinniW Posted October 23, 2017 Share Posted October 23, 2017 "Rain. The rain could be heavy at times. High near 65. South wind 5 to 10 mph, with gusts as high as 20 mph. Chance of precipitation is 90%." That wind sounds a little less damaging than I was expecting. Link to comment Share on other sites More sharing options...
dendrite Posted October 23, 2017 Share Posted October 23, 2017 13 minutes ago, eekuasepinniW said: "Rain. The rain could be heavy at times. High near 65. South wind 5 to 10 mph, with gusts as high as 20 mph. Chance of precipitation is 90%." That wind sounds a little less damaging than I was expecting. Tue night will see the closed low over the GReat Lakes to start making a little better progress to the NE, but it will still be a slow go. This will push the sfc front ewd into NH after midnight. Ahead of the front, expecting a line of convection to form as strong low level jet will be in place just ahead of the front. With the deep moisture ahead of the front, this convection will produce heavy rain, and the possibility of TSRA. Any TSRA could also help mix down the winds from the jet, and good see some gusts approaching severe levels. Currently, this line should be somewhere in the vicinity of the NH/ME border around daybreak on Wed, and will continue across ME Wed morning. This line will likely be responsible for a large part of the rain that falls and could produce an inch to inch and a half in several hours. Link to comment Share on other sites More sharing options...
weatherwiz Posted October 23, 2017 Author Share Posted October 23, 2017 I think people are sort of not understanding the wind situation. This isn't a wind advisory type of setup where we have strong synoptic winds. Winds will be gusty tomorrow but the main deal with the winds is whether convective elements mix down much stronger winds. Link to comment Share on other sites More sharing options...
Damage In Tolland Posted October 23, 2017 Share Posted October 23, 2017 15 minutes ago, weatherwiz said: I think people are sort of not understanding the wind situation. This isn't a wind advisory type of setup where we have strong synoptic winds. Winds will be gusty tomorrow but the main deal with the winds is whether convective elements mix down much stronger winds. Winds gust 35-50 mph synoptically. Anything above that comes with any convection Link to comment Share on other sites More sharing options...
powderfreak Posted October 23, 2017 Share Posted October 23, 2017 18z GFS and NAM in good agreement with 2"+ right up the Taconics, Berks and Greens. Looks like a duel max on the models...one west and one further east in ENE. Link to comment Share on other sites More sharing options...
weatherwiz Posted October 23, 2017 Author Share Posted October 23, 2017 8 minutes ago, Damage In Tolland said: Winds gust 35-50 mph synoptically. Anything above that comes with any convection If there were much steeper low-level lapse rates I could see it happening. We’ll have gusts from the pressure gradient but nothing upwards of that magnitude. Link to comment Share on other sites More sharing options...
Damage In Tolland Posted October 23, 2017 Share Posted October 23, 2017 9 minutes ago, weatherwiz said: If there were much steeper low-level lapse rates I could see it happening. We’ll have gusts from the pressure gradient but nothing upwards of that magnitude. Ryan had 35-50 statewide with higher gusts in convection . This is an extremely volatile situation Link to comment Share on other sites More sharing options...
weatherwiz Posted October 24, 2017 Author Share Posted October 24, 2017 4 minutes ago, Damage In Tolland said: Ryan had 35-50 statewide with higher gusts in convection . This is an extremely volatile situation Did he mean that for convection driven gusts or gusts in general? Bufkit soundings didn’t seem impressive with gust potential Link to comment Share on other sites More sharing options...
weatherwiz Posted October 24, 2017 Author Share Posted October 24, 2017 What do these values under the LCL, LFC, and EL represent? Link to comment Share on other sites More sharing options...
Damage In Tolland Posted October 24, 2017 Share Posted October 24, 2017 4 minutes ago, weatherwiz said: Did he mean that for convection driven gusts or gusts in general? Bufkit soundings didn’t seem impressive with gust potential I just said. Synoptically to 50. You need to look deeper Link to comment Share on other sites More sharing options...
weatherwiz Posted October 24, 2017 Author Share Posted October 24, 2017 5 minutes ago, Damage In Tolland said: I just said. Synoptically to 50. You need to look deeper Oh crap...didn’t realize we had a wind advisory. Guess I do need to look deeper into the synoptic wind aspect Link to comment Share on other sites More sharing options...
Ginx snewx Posted October 24, 2017 Share Posted October 24, 2017 31 minutes ago, Damage In Tolland said: Ryan had 35-50 statewide with higher gusts in convection . This is an extremely volatile situation Euro remains underwhelming. 35 to 50 is probably right with a 60 gust in Branford and he will verify. Not exactly a huge deal,wind advisories in later fall are pretty climo. Link to comment Share on other sites More sharing options...
Damage In Tolland Posted October 24, 2017 Share Posted October 24, 2017 9 minutes ago, Ginx snewx said: Euro remains underwhelming. 35 to 50 is probably right with a 60 gust in Branford and he will verify. Not exactly a huge deal,wind advisories in later fall are pretty climo. I’ll take Ryan thanks Link to comment Share on other sites More sharing options...
Ginx snewx Posted October 24, 2017 Share Posted October 24, 2017 20 minutes ago, Damage In Tolland said: I’ll take Ryan thanks Stay safe Link to comment Share on other sites More sharing options...
dendrite Posted October 24, 2017 Share Posted October 24, 2017 Anomalous LLJ and everyone should see some decent convection at some point. Of course these things tend to find a way to fail up here though. Link to comment Share on other sites More sharing options...
Ginx snewx Posted October 24, 2017 Share Posted October 24, 2017 Just now, dendrite said: Anomalous LLJ and everyone should see some decent convection at some point. Of course these things tend to find a way to fail up here though. No doubt a stormy day Link to comment Share on other sites More sharing options...
CT Rain Posted October 24, 2017 Share Posted October 24, 2017 Looks pretty good to me. We have a bit of CAPE out there so convection could make things pretty interesting. Link to comment Share on other sites More sharing options...
CT Rain Posted October 24, 2017 Share Posted October 24, 2017 SREF sig tor probability. Initial convection - and even overnight stuff - needs to be watched given the amount of low level shear. Link to comment Share on other sites More sharing options...
weatherwiz Posted October 24, 2017 Author Share Posted October 24, 2017 6 minutes ago, CT Rain said: Looks pretty good to me. We have a bit of CAPE out there so convection could make things pretty interesting. holy crap. why isn't the WTBY sounding as impressive with those winds? Really that much of a difference in wind potential between the two places. Link to comment Share on other sites More sharing options...
CT Rain Posted October 24, 2017 Share Posted October 24, 2017 Just now, weatherwiz said: holy crap. why isn't the WTBY sounding as impressive with those winds? Really that much of a difference in wind potential between the two places. You're probably talking a few tenths of a degree that is preventing the "mixing algorithm" from catching it. Given the neutral at worst look to boundary layer stability this event has a lot more potential than those inverted days with a 90 knot LLJ lol Link to comment Share on other sites More sharing options...
weatherwiz Posted October 24, 2017 Author Share Posted October 24, 2017 Just now, CT Rain said: You're probably talking a few tenths of a degree that is preventing the "mixing algorithm" from catching it. Given the neutral at worst look to boundary layer stability this event has a lot more potential than those inverted days with a 90 knot LLJ lol crap...that's my fault for only looking at a bufkit sounding for Waterbury. I would have harped on the synoptic wind threat more. I completely agree...this event has a ton more potential than most setups we see of this nature. Having no inversion (or any noticeable one) just above the deck makes this pretty eye opening. Won't take a great deal of cape for things to happen. Just a question of whether we get enough cape to really worry about rotation and meaningful rotation. I'm sure everything will be rotating to some extent Link to comment Share on other sites More sharing options...
weatherwiz Posted October 24, 2017 Author Share Posted October 24, 2017 The LCL's tomorrow are going to be ridiculously low tomorrow...about as low as I think I've seen. If we generate enough 0-3km CAPE that's going to make things extremely interesting. With the degree of directional wind shear/speed shear in the lowest few km with those low LCL's...something will produce. Link to comment Share on other sites More sharing options...
RUNNAWAYICEBERG Posted October 24, 2017 Share Posted October 24, 2017 Whats the timing of said danger? I have to pick up my kid at 8 in Prospect and make the treck back to DXR. We talking mostly heavy rain at that time or potential spinners that satisfy Wizzy’s weenie? I hate driving in high wind/rain especially with my kid on board. Link to comment Share on other sites More sharing options...
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