CT Rain Posted August 3, 2012 Share Posted August 3, 2012 Yeah I was looking at Tippy FOUS and fell off my seat when I saw the LI of -10. Might be a little much, but swamp azz dews will add to the CAPE no doubt. NAM has steep-ish lapse rates. GFS is busting way too stable this morning per 12z RAOBs. I'd go with the NAM and maybe shave off a few hundred joules for overzealous dews. Link to comment Share on other sites More sharing options...
Tropopause_Fold Posted August 3, 2012 Share Posted August 3, 2012 Yeah not bad at all. The NAM keeps enough CIN at the coast to preclude storm development but inland it definitely removes the CIN with a good deal of CAPE. Weak vertical shear means nothing widespread but microbursts certainly possible. With 500mb subsidence/ridging I'm not sure how widespread storms will be. Look at 6z NAM for tomorrow... very respectable CAPE!!!! Big fat CAPE. yeah agree. would think biggest threat is some scattered/isolated heavy rainers...no real synoptic wind to tap but perhaps some collapsing cores. the actual 7-5h LRs are "just ok" but if you look at the sounding and data there are some embedded layers where the values are much better...on a whole the mid-levels are pretty good. one thing i've noticed though - and this might be tied directly to the height rise issue you pointed out - most guidance is pretty meh on qpf and coverage. re: tomorrow...yeah nice fat CAPE - LI of -8 at BDL. Link to comment Share on other sites More sharing options...
HM Posted August 3, 2012 Share Posted August 3, 2012 Whatever happens now through Monday, enjoy it (still thinking Sunday is a big day). The models struggle to advect in any appreciable EML or even a close but no cigar type of EML through 10 days. While severe weather will be possible with the mean trough overhead, it will probably keep SIG SVR potential lower than it has been as of late. However, these set ups can be fun if you get under a nice t-storm. The question now is: when will the waves elongate and the heat makes another run at the East Coast? Link to comment Share on other sites More sharing options...
CT Rain Posted August 3, 2012 Share Posted August 3, 2012 yeah agree. would think biggest threat is some scattered/isolated heavy rainers...no real synoptic wind to tap but perhaps some collapsing cores. the actual 7-5h LRs are "just ok" but if you look at the sounding and data there are some embedded layers where the values are much better...on a whole the mid-levels are pretty good. one thing i've noticed though - and this might be tied directly to the height rise issue you pointed out - most guidance is pretty meh on qpf and coverage. re: tomorrow...yeah nice fat CAPE - LI of -8 at BDL. Tomorrow may have a better chance of popping stuff in SNE with more neutral height tendency. A little less subsidence may help storm coverage. That said anything that goes today will be a pretty storm. I sort of like Litchfield Hills/Berkshires with elevated heat sources interactive with advancing sea breeze front. May be enough to get surface based parcels to the LFC... especially if dew points continue to rise in the boundary layer to remove CIN from the bottom up. Link to comment Share on other sites More sharing options...
CT Rain Posted August 3, 2012 Share Posted August 3, 2012 Whatever happens now through Monday, enjoy it (still thinking Sunday is a big day). The models struggle to advect in any appreciable EML or even a close but no cigar type of EML through 10 days. While severe weather will be possible with the mean trough overhead, it will probably keep SIG SVR potential lower than it has been as of late. However, these set ups can be fun if you get under a nice t-storm. The question now is: when will the waves elongate and the heat makes another run at the East Coast? How far east do you see things getting? I haven't looked at much but if I were to target an area I'd say SYR to ROC and south toward DUJ/IPT? Weak vertical shear is going to be an issue out this way even with a developing LLJ. 30 knots SW at 925mb and 30 knots SW at 500mb gives you a pretty unimpressive shear vector lol. Link to comment Share on other sites More sharing options...
CoastalWx Posted August 3, 2012 Share Posted August 3, 2012 Tomorrow may have a better chance of popping stuff in SNE with more neutral height tendency. A little less subsidence may help storm coverage. That said anything that goes today will be a pretty storm. I sort of like Litchfield Hills/Berkshires with elevated heat sources interactive with advancing sea breeze front. May be enough to get surface based parcels to the LFC... especially if dew points continue to rise in the boundary layer to remove CIN from the bottom up. Yeah today has that look where elevations or weak boundaries may be enough to focus storms. Tomorrow may have a very weak WF boundary draped across SNE. Link to comment Share on other sites More sharing options...
HM Posted August 3, 2012 Share Posted August 3, 2012 Tomorrow may have a better chance of popping stuff in SNE with more neutral height tendency. A little less subsidence may help storm coverage. That said anything that goes today will be a pretty storm. I sort of like Litchfield Hills/Berkshires with elevated heat sources interactive with advancing sea breeze front. May be enough to get surface based parcels to the LFC... especially if dew points continue to rise in the boundary layer to remove CIN from the bottom up. I like seeing words like "neutral tendency" etc. because thunderstorms are like drug addicts. The actual numbers are important but the tendency is probably somewhat more important. While no one will argue that 2000 j/kg of CAPE is meager, it certainly will be if thunderstorms are moving into that environment after had developed in a region of 4000 j/kg. Trends in theta-e/advection, isotrope slopes etc. are pretty important (as we learned last week), even if your conditions at your location are fine in and of themselves for severe. Link to comment Share on other sites More sharing options...
CT Rain Posted August 3, 2012 Share Posted August 3, 2012 I like seeing words like "neutral tendency" etc. because thunderstorms are like drug addicts. The actual numbers are important but the tendency is probably somewhat more important. While no one will argue that 2000 j/kg of CAPE is meager, it certainly will be if thunderstorms are moving into that environment after had developed in a region of 4000 j/kg. Trends in theta-e/advection, isotrope slopes etc. are pretty important (as we learned last week), even if your conditions at your location are fine in and of themselves for severe. Totally agree. I see many newer mets and people learning get wrapped up in numbers and indicies. When I was learning this stuff on my own 15+ years ago besides a crude LI, SWI, or CAPE chart you didn't have much else. Pattern recognition and identifying features was just as important as the "numbers". Link to comment Share on other sites More sharing options...
HM Posted August 3, 2012 Share Posted August 3, 2012 How far east do you see things getting? I haven't looked at much but if I were to target an area I'd say SYR to ROC and south toward DUJ/IPT? Weak vertical shear is going to be an issue out this way even with a developing LLJ. 30 knots SW at 925mb and 30 knots SW at 500mb gives you a pretty unimpressive shear vector lol. The shear vector's direction coupled with the deep layer moisture / surface winds and h2 ridge could actually allow for some type of convective system that sweeps to the northern Mid Atlantic coast overnight. The tornado potential will obviously be favored in that area you highlight where the mid level and low level wind maximums pass over but the degree of instability is in question with northward extent. I could see most of PA at risk for an isolated tornado, even across S-C portions. Link to comment Share on other sites More sharing options...
Tropopause_Fold Posted August 3, 2012 Share Posted August 3, 2012 seems to be a bit of a dewpoint boundary draped across the region today. however slight it is..mid and upper 60s to the N of it...lower and middle 70s south of it. don't think it's simply a product of southerly flow advecting in moisture off the water as it seems to extend well SW of us. Link to comment Share on other sites More sharing options...
CT Rain Posted August 3, 2012 Share Posted August 3, 2012 seems to be a bit of a dewpoint boundary draped across the region today. however slight it is..mid and upper 60s to the N of it...lower and middle 70s south of it. don't think it's simply a product of southerly flow advecting in moisture off the water as it seems to extend well SW of us. Just noticed this as well. Seems as if some of the higher td air is advecting north off the water while at the same time just inland turbulent mixing is helping mix out some of the moisture right near the surface. This will probably continue through the day for a bit... that moisture discontinuity may be a focal point for convection later? Link to comment Share on other sites More sharing options...
CoastalWx Posted August 3, 2012 Share Posted August 3, 2012 Totally agree. I see many newer mets and people learning get wrapped up in numbers and indicies. When I was learning this stuff on my own 15+ years ago besides a crude LI, SWI, or CAPE chart you didn't have much else. Pattern recognition and identifying features was just as important as the "numbers". I feel like every year there are new numbers or names for indices. Data overload. Sometimes it's just as easier to look at the basics and make a forecast based on what you said...pattern recognition. It will likely be more accurate too, as many times your head will spin with the many different things out there. One index that I use a lot when forecasting....especially down in the Carb, is KI. I find KI can be a pretty useful tool, especially down there with any waves moving through. Link to comment Share on other sites More sharing options...
CoastalWx Posted August 3, 2012 Share Posted August 3, 2012 Just noticed this as well. Seems as if some of the higher td air is advecting north off the water while at the same time just inland turbulent mixing is helping mix out some of the moisture right near the surface. This will probably continue through the day for a bit... that moisture discontinuity may be a focal point for convection later? Yeah FIT seems to be mixing out a bit. Link to comment Share on other sites More sharing options...
Tropopause_Fold Posted August 3, 2012 Share Posted August 3, 2012 Just noticed this as well. Seems as if some of the higher td air is advecting north off the water while at the same time just inland turbulent mixing is helping mix out some of the moisture right near the surface. This will probably continue through the day for a bit... that moisture discontinuity may be a focal point for convection later? yeah some of it may be a product of mixing out...especially as they drop later today. there seems to be a bit of an airmass change though too. Link to comment Share on other sites More sharing options...
CT Rain Posted August 3, 2012 Share Posted August 3, 2012 I feel like every year there are new numbers or names for indices. Data overload. Sometimes it's just as easier to look at the basics and make a forecast based on what you said...pattern recognition. It will likely be more accurate too, as many times your head will spin with the many different things out there. One index that I use a lot when forecasting....especially down in the Carb, is KI. I find KI can be a pretty useful tool, especially down there with any waves moving through. The other day last week with the big bust all of us got a bit carried away with the numbers game. It's hard in the event when you're working to take a step back and reevaluate. For example the 18z NAM and the RAP soundings in retrospect showed a lot of CAPE but also a TON of CINH. As that line was moving east had I spent the time reanalyzing the threat and not getting so wrapped up in radar and very specific info I probably would have been better informed. In fact many of the runs continued to show CINH increasing ahead of that line with LFCs over 800mb! CAPE is great... but you have to get to it lol. Link to comment Share on other sites More sharing options...
CT Rain Posted August 3, 2012 Share Posted August 3, 2012 yeah some of it may be a product of mixing out...especially as they drop later today. there seems to be a bit of an airmass change though too. We'll probably see it become a little sharper later today too with mixing to the north and advection to the south of the sea breeze front. I imagine if that front is able to push inland to the hills we could pop something. Link to comment Share on other sites More sharing options...
CoastalWx Posted August 3, 2012 Share Posted August 3, 2012 The other day last week with the big bust all of us got a bit carried away with the numbers game. It's hard in the event when you're working to take a step back and reevaluate. For example the 18z NAM and the RAP soundings in retrospect showed a lot of CAPE but also a TON of CINH. As that line was moving east had I spent the time reanalyzing the threat and not getting so wrapped up in radar and very specific info I probably would have been better informed. In fact many of the runs continued to show CINH increasing ahead of that line with LFCs over 800mb! CAPE is great... but you have to get to it lol. Yeah good points. That's the fun thing about meteorology. It's always a learning experience. Link to comment Share on other sites More sharing options...
OSUmetstud Posted August 3, 2012 Author Share Posted August 3, 2012 Sunday looks run of the mill to me. No EML, a good deal of morning convective issues, modest shear (SREF is just below 30 kt) and modest instability. Link to comment Share on other sites More sharing options...
CT Rain Posted August 3, 2012 Share Posted August 3, 2012 Sunday looks run of the mill to me. No EML, a good deal of morning convective issues, modest shear (SREF is just below 30 kt) and modest instability. Eh, I dunno. Looks pretty good for PA/Upstate NY. Strong LLJ is unusual for a convective threat this time of year. Instability probably will be an issue in some areas for the issues you mentioned but I'd feel pretty good if I lived in portions of central NY/PA. Link to comment Share on other sites More sharing options...
CT Rain Posted August 3, 2012 Share Posted August 3, 2012 Storm firing up on c breeze front on Long Island Link to comment Share on other sites More sharing options...
OSUmetstud Posted August 3, 2012 Author Share Posted August 3, 2012 Eh, I dunno. Looks pretty good for PA/Upstate NY. Strong LLJ is unusual for a convective threat this time of year. Instability probably will be an issue in some areas for the issues you mentioned but I'd feel pretty good if I lived in portions of central NY/PA. I think it looks like a slight risk day...15-30%. I don't see moderate. The mid-level winds appear to be lagging behind the best LLJ. Plus, given the moisture and the lack of EML i think morning convection/clouds could muck up the ability to realize the 1500 or so MLCAPE that is being modeled. Link to comment Share on other sites More sharing options...
radarman Posted August 3, 2012 Share Posted August 3, 2012 Will have to keep a close eye on things around here this weekend. Great New England Airshow being held at Westover and they're estimating up to 500,000 people over 2 days. Regardless of severity, any storms around have the potential to wreak havoc on the proceedings. Link to comment Share on other sites More sharing options...
Tropopause_Fold Posted August 3, 2012 Share Posted August 3, 2012 hrw and hrrr both go kinda nuts late this afternoon / this evening. seems a bit much with the coverage but timing might be right as NAM (though didn't check 12z) had cap being broken pretty late. Link to comment Share on other sites More sharing options...
CoastalWx Posted August 3, 2012 Share Posted August 3, 2012 hrw and hrrr both go kinda nuts late this afternoon / this evening. seems a bit much with the coverage but timing might be right as NAM (though didn't check 12z) had cap being broken pretty late. SPC WRF has a late start to convection as well. Link to comment Share on other sites More sharing options...
CoastalWx Posted August 3, 2012 Share Posted August 3, 2012 Dews are mixing out so I'm having some doubts. Link to comment Share on other sites More sharing options...
Ginx snewx Posted August 3, 2012 Share Posted August 3, 2012 Dews are mixing out so I'm having some doubts. Just brutal here in SECT 88/75 Link to comment Share on other sites More sharing options...
CT Rain Posted August 3, 2012 Share Posted August 3, 2012 Just brutal here in SECT 88/75 Yeah awful south of c breeze front. Link to comment Share on other sites More sharing options...
HM Posted August 3, 2012 Share Posted August 3, 2012 The other day last week with the big bust all of us got a bit carried away with the numbers game. It's hard in the event when you're working to take a step back and reevaluate. For example the 18z NAM and the RAP soundings in retrospect showed a lot of CAPE but also a TON of CINH. As that line was moving east had I spent the time reanalyzing the threat and not getting so wrapped up in radar and very specific info I probably would have been better informed. In fact many of the runs continued to show CINH increasing ahead of that line with LFCs over 800mb! CAPE is great... but you have to get to it lol. I feel like every year there are new numbers or names for indices. Data overload. Sometimes it's just as easier to look at the basics and make a forecast based on what you said...pattern recognition. It will likely be more accurate too, as many times your head will spin with the many different things out there. One index that I use a lot when forecasting....especially down in the Carb, is KI. I find KI can be a pretty useful tool, especially down there with any waves moving through. Of course, on the flip side to that, it's not like these numbers/indices are based on imaginary things. They are based on tangible things that affect the atmosphere. I definitely agree with both of you that the basics need to be addressed first before getting into specifics, e.g. indices; but, we should also remember that they are based on tangible atmospheric elements. Link to comment Share on other sites More sharing options...
forkyfork Posted August 3, 2012 Share Posted August 3, 2012 this is the highest dewpoint i've had all year (not including post thunderstorm moisture) Link to comment Share on other sites More sharing options...
HM Posted August 3, 2012 Share Posted August 3, 2012 this is the highest dewpoint i've had all year (not including post thunderstorm moisture) Before a severe thunderstorm complex was arriving, my dewpoint hit 75 but I can't remember which event it was. Today I only hit 74 before mixing out to 69 so DP fail! lol I still like Sunday even with all the issues on the NWP right now. Link to comment Share on other sites More sharing options...
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