Typhoon Tip Posted July 24, 2012 Share Posted July 24, 2012 I mentioned this yesterday but am not sure it fell on listening ears as there was ongoing activity in play. This is your day - D3 (Thur). For me, this is one of the best looking table sets of the season that I have personally seen. This is a longitudinal wave set up in the sense that the vorticity is not already conserved in a steep meridian oriented trough or closed low. This way most of the vorticity is spread out through the column in the form of shear. It is tough to say exactly how the directional versus velocity kinematics will orient - some of that always comes to now-casting, as often times we will find that the 0-3km wind was handled less accurately. However, sufficed it is to say, we have an open wave transporting high CAPE(high potential CAPE) air in a warm sector that will likely roll up to about a Watertown NY - Concord NH approximate line; that may be generous as the Euro seems to want to limit it to NYC. This times neatly with diabatic heating later Thursday. It is something to watch, because if the warm sector penetrates even a little more proficiently to where dirty sun heats the column, we then contend with the right entrance region of potent enough mid/U/A wind max; first entering the upper OV and then translating such that eventually much of the area passes through the jet core and wind up on the left exit side. Pick your poison.. but if the runs are heading in the right direction, it wouldn't surprise me to see some part of this region go to moderate risk - rare for this part of the country, I know. I would look up stream toward Michigan/Wisconsin - there is a bit of lag teleconnector for convection in those regions wrt to local events some 18 to 24 hours later. There's also possibilities in there for antecedent MCS/elevated stuff as fairly potent WAA begins ...at some point earlier in the period(s). Link to comment Share on other sites More sharing options...
HM Posted July 24, 2012 Share Posted July 24, 2012 I mentioned this yesterday but am not sure it fell on listening ears as there was ongoing activity in play. This threat has been on everyone's radar for at least 10 days. At one point, the SPC even mentioned it in their extended range (around day 8 I think). Naturally, as we get closer, things don't look as nice. The morning round, the slower arrival of the SLP and possible recovery issues are all in the back of my mind. At this point, S-C NY into PA look game for a possible moderate risk Thursday. I also like the overnight Wed-Thu AM potential you and several others have highlighted. Link to comment Share on other sites More sharing options...
OSUmetstud Posted July 24, 2012 Share Posted July 24, 2012 nice disco from Hitchcock at BUF...more relevant for areas further west but still a good summation of the situation. .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AT THE START OF THE PERIOD ON WEDNESDAY HIGH PRESSURE WILL BE IN CONTROL ACROSS THE LOWER LAKES WITH PLENTY OF SUNSHINE. LIGHT SYNOPTIC SCALE WINDS WILL ALLOW LAKE BREEZES TO DEVELOP BY EARLY AFTERNOON WITH LOCALLY ONSHORE WINDS ALONG THE LAKESHORES. 850MB TEMPS OF AROUND +13 WILL SUPPORT HIGHS VERY CLOSE TO MID SUMMER NORMALS WITH LOWER 80S ACROSS LOWER ELEVATIONS AND UPPER 70S HIGHER TERRAIN AND ALONG THE LAKES. FORECAST BECOMES MUCH MORE INTERESTING WEDNESDAY NIGHT INTO THURSDAY. MODEL GUIDANCE REMAINS CONSISTENT ON BRINGING A SIGNIFICANT SURFACE LOW AND CONVECTIVELY AUGMENTED MID LEVEL VORTICITY CENTER THROUGH THE GREAT LAKES STATES DURING THIS PERIOD...ALTHOUGH RUN TO RUN AND INTER-MODEL DIFFERENCES ARE STILL THERE WITH REGARDS TO EXACT TRACK AND TIMING. TRACING THIS FEATURE BACK IN MODEL GUIDANCE...IT APPEARS TO BE RELATED TO A WEAK CLOSED LOW OVER WEST TEXAS EARLY THIS MORNING. THIS FEATURE WILL BE CAPTURED BY SOUTHERLY MONSOON FLOW OVER THE ROCKIES AND IS FORECAST TO INTERACT WITH A TROUGH OVER SASKATCHEWAN TO FORM A WEAK LOW OVER THE NORTHERN PLAINS TONIGHT. AN MCS IS ALSO FORECAST TO DEVELOP IN THIS SAME GENERAL AREA...WHICH IS FORECAST TO PROJECT ONTO THE SYNOPTIC SCALE AND HELP DEEPEN THE SURFACE LOW AND MID LEVEL VORTICITY CENTER AS THEY HEAD INTO THE WESTERN GREAT LAKES WEDNESDAY NIGHT. THIS SCENARIO IS HIGHLY COMPLEX...AND WOULD EXPECT FURTHER ADJUSTMENTS IN THE TIMING AND TRACK DETAILS IN MODEL GUIDANCE FOR THE NEXT 24 HOURS UNTIL THE MAIN PLAYERS BEGIN TO MATURE. IN ADVANCE OF THE SYSTEM WEDNESDAY NIGHT A LEAD SHORTWAVE AND A WING OF MODERATE TO STRONG WARM ADVECTION ON THE NORTHEAST EDGE OF THE ELEVATED MIXED LAYER /EML/ PLUME WILL SUPPORT INCREASING LARGE SCALE ASCENT ACROSS THE CENTRAL AND EASTERN GREAT LAKES. THIS WILL BRING RAIN CHANCES INTO THE AREA OVERNIGHT...AND LATEST GUIDANCE SUGGESTS THE BEST FORCING AND MOISTURE WILL BE FOUND FROM LAKE ONTARIO NORTHWARD. WITH THIS IN MIND WILL JUST GO WITH LOW CHANCE POPS NEAR THE PENNSYLVANIA STATE LINE...INCREASING TO LIKELY OVER LAKE ONTARIO FOR LATE WEDNESDAY NIGHT. ON THURSDAY THE GFS HAS TRENDED A LITTLE FURTHER NORTH WITH THE TRACK OF THE SURFACE LOW AND NOW HAS IT MOVING OVER LAKE ONTARIO. THE NAM AND ECMWF ARE A LITTLE FURTHER SOUTH AND WEAKER...BUT EVEN THESE WEAKER SOLUTIONS ALLOW VERY WARM AIR TO ADVECT INTO AREAS SOUTH OF LAKE ONTARIO AS THE EASTERN EDGE OF THE EML PLUME IS CAPTURED AND ADVECTED INTO THE LOWER LAKES AHEAD OF THE SYSTEM. WITH QUALITY DYNAMICS AND MOISTURE COMING TOGETHER WILL CONTINUE WITH LIKELY POPS FOR THURSDAY...ALTHOUGH PLACEMENT OF STEADIER/HEAVIER RAIN REMAINS IN QUESTION. EMBEDDED THUNDERSTORMS ARE ALSO LIKELY GIVEN THE RESERVOIR OF STRONG INSTABILITY JUST UPSTREAM. TEMPERATURES ARE A TRICKY CALL. VERY WARM TEMPS AT 850MB WILL SUPPORT HIGHS IN THE MID TO UPPER 80S WITH JUST A FEW HOURS OF DRY WEATHER AND SUNSHINE. ON THE OTHER HAND IF THICK CLOUD COVER AND SHOWERS PREVAIL IT WILL BE MUCH COOLER. HAVE GONE WITH A WARMER SOLUTION SOUTH OF LAKE ONTARIO WHERE SOME BREAKS IN PRECIP ARE EXPECTED. THURSDAY NIGHT THE FRONTAL BOUNDARY EASES SLOWLY SOUTH ACROSS THE REGION WITH ADDITIONAL SHOWERS AND THUNDERSTORMS LIKELY. THIS SYSTEM HAS THE POTENTIAL FOR PRODUCING THE FIRST WIDESPREAD RAINFALL IN QUITE SOME TIME. THIS WILL NOT END THE DROUGHT BY ANY MEANS...BUT MAY PROVIDE SOME SHORT TERM RELIEF TO SURFACE SOIL MOISTURE. THIS SYSTEM MAY ALSO HAVE SOME SEVERE WEATHER POTENTIAL AS WELL. BOTH THE NAM AND GFS DEVELOP A STRONG LOW LEVEL JET WEDNESDAY NIGHT WHICH WILL TRANSPORT VERY UNSTABLE AIR OUT FROM BENEATH THE EML PLUME AND INTO THE MODERATE TO STRONG WARM ADVECTION REGIME ACROSS THE CENTRAL AND UPPER LAKES. THIS CAN BE A FAVORABLE SCENARIO FOR INTENSE MCS DEVELOPMENT. IF AN MCS DOES FORM WEDNESDAY EVENING ACROSS THE UPPER LAKES...IT MAY TRACK ESE INTO OUR REGION LATE WEDNESDAY NIGHT OR THURSDAY MORNING WITH AN ATTENDANT RISK OF DAMAGING WINDS AND LOCAL FLOODING. ON THURSDAY IN THE WAKE OF THE POTENTIAL MCS THE AIRMASS WILL DESTABILIZE ONCE AGAIN...ESPECIALLY IF THE FARTHER NORTH SURFACE LOW OF THE GFS SOLUTION VERIFIES. MODERATE SHEAR WILL BE IN PLACE AND MAY SUPPORT AN ENVIRONMENT FAVORABLE OF ADDITIONAL SEVERE WEATHER THURSDAY AFTERNOON AND EVENING. Link to comment Share on other sites More sharing options...
OSUmetstud Posted July 24, 2012 Share Posted July 24, 2012 This threat has been on everyone's radar for at least 10 days. At one point, the SPC even mentioned it in their extended range (around day 8 I think). Naturally, as we get closer, things don't look as nice. The morning round, the slower arrival of the SLP and possible recovery issues are all in the back of my mind. At this point, S-C NY into PA look game for a possible moderate risk Thursday. I also like the overnight Wed-Thu AM potential you and several others have highlighted. You thinking MCS on Wednesday night? It looks ripe. From the dewpoint charts it appears that the dry line will make it quite far east on Wednesday night, maybe eastern IN, Western Oh? Link to comment Share on other sites More sharing options...
OSUmetstud Posted July 24, 2012 Share Posted July 24, 2012 yeah, the SPC had the eastern Lakes/PA and NY in the Day 8 and then didn't highlight the specific threat again until Day 3. Originally I believe we were talking the main upper level low being the main culprate but it appears the wave out ahead of on Wednesday night/Thursday will be the main show instead. Link to comment Share on other sites More sharing options...
Damage In Tolland Posted July 24, 2012 Share Posted July 24, 2012 There is a TOR threat and flooding from training cells from this. Link to comment Share on other sites More sharing options...
HM Posted July 24, 2012 Share Posted July 24, 2012 You thinking MCS on Wednesday night? It looks ripe. From the dewpoint charts it appears that the dry line will make it quite far east on Wednesday night, maybe eastern IN, Western Oh? The term "MCS" doesn't do this justice, given the autumn-like dynamics in the synoptic metrics at play. This impressive insentropic lift / thermal advection on the leading edge of an impressive EML will likely lead to an extensive area of severe convection/heavy rainfall overnight / early THU for NY-New England. The dry line will likely wash out / become diffuse once it interacts with the Appalachians. However, if the SLP can become deep enough, it wouldn't shock me to see more upper level descent into the backside, allowing it to come eastward. Link to comment Share on other sites More sharing options...
OSUmetstud Posted July 24, 2012 Share Posted July 24, 2012 I think there is a reasonable MCS threat on Thursday afternoon/evening, also. Mainly for SE NY/northern NJ/SW SNE. There is a distinctive EML on the NAM...it appears to be located a bit lower than most EMLs, more in the 600-800mb layer instead of the 500-700mb layer. Link to comment Share on other sites More sharing options...
HM Posted July 24, 2012 Share Posted July 24, 2012 yeah, the SPC had the eastern Lakes/PA and NY in the Day 8 and then didn't highlight the specific threat again until Day 3. Originally I believe we were talking the main upper level low being the main culprate but it appears the wave out ahead of on Wednesday night/Thursday will be the main show instead. Yes, it originally looked like Friday but as usual, the situation becomes more cluttered as we get closer. This is going to be a very active 24-36 hr period from the Lakes to the Northeast. Link to comment Share on other sites More sharing options...
CapturedNature Posted July 24, 2012 Share Posted July 24, 2012 I heard all the thunder and nice light show..but not a drop. You also got the storm last evening didn't you? Though that may have been more for Union I missed last evenings storm but I heard it...might have gotten a drop or two from it though. I'm just north of the center of town. Link to comment Share on other sites More sharing options...
OSUmetstud Posted July 24, 2012 Share Posted July 24, 2012 The term "MCS" doesn't do this justice, given the autumn-like dynamics in the synoptic metrics at play. This impressive insentropic lift / thermal advection on the leading edge of an impressive EML will likely lead to an extensive area of severe convection/heavy rainfall overnight / early THU for NY-New England. The dry line will likely wash out / become diffuse once it interacts with the Appalachians. However, if the SLP can become deep enough, it wouldn't shock me to see more upper level descent into the backside, allowing it to come eastward. right...it's just that it should be elevated. I wonder if there is a pretty decent hail threat on Wednesday night/early Thursday as opposed to a wind threat. Link to comment Share on other sites More sharing options...
HM Posted July 24, 2012 Share Posted July 24, 2012 I think there is a reasonable MCS threat on Thursday afternoon/evening, also. Mainly for SE NY/northern NJ/SW SNE. There is a distinctive EML on the NAM...it appears to be located a bit lower than most EMLs, more in the 600-800mb layer instead of the 500-700mb layer. If we can get a more progressive SLP to plow into southern New England THU evening, a heightened tornado risk would exist from S NY / N PA into MA / CT. The degree of instability is in question given the morning round (but that will keep those LCL heights low). Should the early MCS leave a nice T gradient, that could also serve as a focal point for supercells and possibly strong ones with the pressure falls and wind shear at play. Link to comment Share on other sites More sharing options...
HM Posted July 24, 2012 Share Posted July 24, 2012 right...it's just that it should be elevated. I wonder if there is a pretty decent hail threat on Wednesday night/early Thursday as opposed to a wind threat. I think that the bulk of it, spatially, will be elevated/stratiform but the dynamics at play will allow for embedded surface-based storms (perhaps on the most south/west side). In fact, I would think both large hail and damaging winds will be a threat. In order for that to occur, the dynamics on the data currently have to be realized; otherwise, this will end up an elevated / less interesting MCS. Link to comment Share on other sites More sharing options...
EasternUSWX Posted July 24, 2012 Share Posted July 24, 2012 How is South Central PA looking for this event? Link to comment Share on other sites More sharing options...
OSUmetstud Posted July 24, 2012 Share Posted July 24, 2012 I think that the bulk of it, spatially, will be elevated/stratiform but the dynamics at play will allow for embedded surface-based storms (perhaps on the most south/west side). In fact, I would think both large hail and damaging winds will be a threat. In order for that to occur, the dynamics on the data currently have to be realized; otherwise, this will end up an elevated / less interesting MCS. I think the major concern for SNE is whether the warm front can make into the bulk of the area...if not the severe threat would be farther south. Link to comment Share on other sites More sharing options...
OSUmetstud Posted July 24, 2012 Share Posted July 24, 2012 GFS is trying to make the plains upper level low a bigger part of the potential outbreak. It tries to phase them a bit. It helps lift the low farther a bit farther north which is better for severe weather in SNE and NYS. Link to comment Share on other sites More sharing options...
CoastalWx Posted July 24, 2012 Share Posted July 24, 2012 Getting a decent storm here now at the lake. Link to comment Share on other sites More sharing options...
Damage In Tolland Posted July 24, 2012 Share Posted July 24, 2012 Nice line of storms firing up from ENY to SNH Link to comment Share on other sites More sharing options...
Typhoon Tip Posted July 24, 2012 Author Share Posted July 24, 2012 This threat has been on everyone's radar for at least 10 days. At one point, the SPC even mentioned it in their extended range (around day 8 I think). Naturally, as we get closer, things don't look as nice. The morning round, the slower arrival of the SLP and possible recovery issues are all in the back of my mind. At this point, S-C NY into PA look game for a possible moderate risk Thursday. I also like the overnight Wed-Thu AM potential you and several others have highlighted. Okay. That may very well be - not intending to take any credit there - I could care less who situates the notice. I just didn't want to come off as a chest beater by repeating things. I also don't spend quite as much time on the boards as others, so forgive my negligence. That said, ... yeah, I remember seeing this in the charts my self a back when, but with convection, I am much less inclined to doing any extended lead write-ups compared to our synoptic-scaled events during the cold season. You are right! As usual, the 12z run of the NAM appears somewhat less interesting aloft... If we transport the higher CAPE air though, we really don't need much in the way of kinematics to realize a very energetic result. Agreed, I like the WAA period as well. Could be some strobing yee ha! Link to comment Share on other sites More sharing options...
forkyfork Posted July 24, 2012 Share Posted July 24, 2012 Yes, it originally looked like Friday but as usual, the situation becomes more cluttered as we get closer. This is going to be a very active 24-36 hr period from the Lakes to the Northeast. i still think it looks good for us... i think the warm front stalls somewhere in CT Link to comment Share on other sites More sharing options...
Damage In Tolland Posted July 24, 2012 Share Posted July 24, 2012 WarM front will stall in SNH . That seems where most guidance puts it Link to comment Share on other sites More sharing options...
OSUmetstud Posted July 24, 2012 Share Posted July 24, 2012 WarM front will stall in SNH . That seems where most guidance puts it warm front is over your head on the Euro...looks like it's in SW CT/SE NY on the NAM. Link to comment Share on other sites More sharing options...
moneypitmike Posted July 24, 2012 Share Posted July 24, 2012 WarM front will stall in SNH . That seems where most guidance puts it Ummmmm--that is good? Link to comment Share on other sites More sharing options...
free_man Posted July 24, 2012 Share Posted July 24, 2012 Ummmmm--that is good? good for rain chances. Link to comment Share on other sites More sharing options...
moneypitmike Posted July 24, 2012 Share Posted July 24, 2012 warm front is over your head on the Euro...looks like it's in SW CT/SE NY on the NAM. good for rain chances. Further south (as Scott says) still good for rain? Sorry for the dumb questions. Link to comment Share on other sites More sharing options...
Damage In Tolland Posted July 24, 2012 Share Posted July 24, 2012 Ummmmm--that is good? You want it right near you or to your north for Tors Link to comment Share on other sites More sharing options...
Damage In Tolland Posted July 24, 2012 Share Posted July 24, 2012 warm front is over your head on the Euro...looks like it's in SW CT/SE NY on the NAM. Your beloved GFS has it much farther north Link to comment Share on other sites More sharing options...
OSUmetstud Posted July 24, 2012 Share Posted July 24, 2012 Further south (as Scott says) still good for rain? Sorry for the dumb questions. you want to be north of the warm front for the best rain...just south is better for severe Link to comment Share on other sites More sharing options...
free_man Posted July 24, 2012 Share Posted July 24, 2012 two min ago..bubbly Link to comment Share on other sites More sharing options...
OSUmetstud Posted July 24, 2012 Share Posted July 24, 2012 Your beloved GFS has it much farther north Beloved eh lol. Yes it does, I'm not sure if it's right though Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.