earthlight Posted July 25, 2012 Share Posted July 25, 2012 ...MID-MS/OH VALLEYS TO THE NORTHEAST/SRN NEW ENGLAND... CONFIDENCE CONTINUES TO GROW WITH POTENTIAL FOR SCATTERED TO NUMEROUS ORGANIZED SEVERE TSTMS...PARTICULARLY FROM THE MIDWEST TO THE NORTHEAST. AN MCS SHOULD BE ONGOING ACROSS PARTS OF THE LOWER GREAT LAKES...SUPPORTED BY AN INITIAL MID-LEVEL SPEED MAX AND ROBUST LOW-LEVEL WAA ADVECTION. THIS SHOULD RETARD THE NERN ADVANCEMENT OF THE WARM FRONT AND SUBSEQUENT EVOLUTION OF THIS ACTIVITY DOES BREED UNCERTAINTY OVER WHERE THE FRONT WILL ULTIMATELY ANCHOR. AN EXPANSIVE UNCAPPED WARM SECTOR CHARACTERIZED BY 90S/60S SURFACE TEMPERATURES/DEW POINTS WILL CONTRIBUTE TO MODERATE TO STRONG BUOYANCY THU AFTERNOON WITH MLCAPE OF 2000-4000 J/KG. A LARGE SWATH OF 30-50 KT 700-500 MB WLYS WILL OVERLAP THIS INSTABILITY...AND WITH WEAK MID-LEVEL HEIGHT FALLS COMBINING WITH FRONTAL CONVERGENCE...THIS SETUP WILL YIELD SCATTERED TO NUMEROUS TSTMS FORMING ALONG AND AHEAD OF THE COLD FRONT. THE UNIDIRECTIONAL WIND PROFILES AND STEEP LOW-LEVEL LAPSE RATES SHOULD SUPPORT UPSCALE GROWTH INTO SEVERAL CLUSTERS WITH BOWING SEGMENTS AND EMBEDDED SUPERCELL STRUCTURES. DAMAGING WINDS /POTENTIALLY WIDESPREAD AND SIGNIFICANT/ WILL BE THE PRIMARY THREAT. A RELATIVELY NARROW CORRIDOR OF ENHANCED TORNADO RISK SHOULD DEVELOP ALONG THE WARM FRONTAL ZONE WHERE EFFECTIVE SRH AND STRONGEST DEEP-LAYER SHEAR WILL BE MAXIMIZED. ALTHOUGH PINPOINTING THIS CORRIDOR IS DIFFICULT GIVEN LIKELIHOOD OF PRECEDING OVERNIGHT CONVECTION...IT APPEARS MOST PROBABLE FROM PARTS OF NY INTO SRN NEW ENGLAND. SOME CONVECTION-ALLOWING GUIDANCE SUGGESTS THAT DISCRETE CONVECTION MAY FORM WITHIN A PERSISTING WAA REGIME THU AFTERNOON. Link to comment Share on other sites More sharing options...
blizzardof09 Posted July 25, 2012 Share Posted July 25, 2012 earthlight, due to some debbie downers in the other thread, what do you honestly think so far for tommorow? i still say NYC east, west and north are still in the game for some big severe weather tommorow and maybe a derecho forming Link to comment Share on other sites More sharing options...
LocoAko Posted July 25, 2012 Share Posted July 25, 2012 re: model differences - the GFS doesn't seem to be advecting the Elevated Mixed Layer over our area, hence the weaker cap and smaller lapse rates. There's also slightly less backing of winds at the surface, but winds aloft are still decently strong. And nothing is "busting". Besides the fact that the event hasn't happened yet, the best combo of shear and instability was always supposed to be to our N&W up in NE PA and SE NY state. Nothing is trending away at the last minute or anything. Link to comment Share on other sites More sharing options...
Superstorm93 Posted July 25, 2012 Share Posted July 25, 2012 SREF looks good for the NYC metro with very decent wind potential. 18z NAM has some excellent parameters, but no convection on the precip fields. GFS is just depressing. 4km NAM looks pretty good as well. Link to comment Share on other sites More sharing options...
Superstorm93 Posted July 25, 2012 Share Posted July 25, 2012 Huge differences on the NMM/ARW Link to comment Share on other sites More sharing options...
LocoAko Posted July 25, 2012 Share Posted July 25, 2012 Please tell me what other model has us getting killed tommorow morning like the stormvista showed??? Seriously, if i am wrong i am wrong, but i havent seen it. Not everything is about the QPF maps. All the models I've looked at (Euro, SREF, NAM) have the same unstable setup. Link to comment Share on other sites More sharing options...
Superstorm93 Posted July 25, 2012 Share Posted July 25, 2012 The way 7/18 shifted south with the actual convection was pretty pronounced. Severe setups rarely play out like they are modeled on the QPF fields. Link to comment Share on other sites More sharing options...
CooL Posted July 25, 2012 Share Posted July 25, 2012 The way 7/18 shifted south with the actual convection was pretty pronounced. Severe setups rarely play out like they are modeled on the QPF fields. Agreed. Just because people are not in the 2"+ contours doesnt mean the threat is lower. The dynamics will still be present, and they are rather impressive. Link to comment Share on other sites More sharing options...
earthlight Posted July 25, 2012 Author Share Posted July 25, 2012 You can see the 500mb setup coming into better focus now on the NAM. If we can get convection to develop over Northern PA, it shouldn't have any trouble advecting east/southeast into 40kts of effective shear and extremely impressive instability numbers. The timing definitely favors the convective complex coming into the area around/ after 7-8pm...but the instability and kinematics will still be terrific anyway. The SPC SREF has high probabilities for derecho maintenance. http://www.meteo.psu...AST_18z/f33.gif Link to comment Share on other sites More sharing options...
psv88 Posted July 25, 2012 Share Posted July 25, 2012 You can see the 500mb setup coming into better focus now on the NAM. If we can get convection to develop over Northern PA, it shouldn't have any trouble advecting east/southeast into 40kts of effective shear and extremely impressive instability numbers. The timing definitely favors the convective complex coming into the area around/ after 7-8pm...but the instability and kinematics will still be terrific anyway. The SPC SREF has high probabilities for derecho maintenance. http://www.meteo.psu...AST_18z/f33.gif John, what are your thoughts about the morning? Scattered showers and heavier stuff to the north? Link to comment Share on other sites More sharing options...
blizzardof09 Posted July 25, 2012 Share Posted July 25, 2012 John, what are your thoughts about the morning? Scattered showers and heavier stuff to the north? the morning stuff is gonna be scattered at best. its suppose to go north of our area. then clearing and the main show in the evening bud Link to comment Share on other sites More sharing options...
earthlight Posted July 25, 2012 Author Share Posted July 25, 2012 John, what are your thoughts about the morning? Scattered showers and heavier stuff to the north? The NAM and GFS have differences which will obviously have a big impact on the forecast...but yes I think the activity with the elevated convection along the WAA/WF should be to our north over Central NY/New England. The NAM has it farther south...clipping parts of Northeast PA/Southeast NY. The NAM is also about 50-100 miles farther south with the 582dm height line at 15-18z than the GFS. The NAM has been insistent on developing an MCS over Northern PA/Southern NY and tracking it east/southeast along this gradient...into 40+kts of effective shear and high instability over N NJ/SE NY/NYC/etc. All things to watch carefully overnight tonight w/ forecast models and early tomorrow with mesoscale forecasting. P.S- Over-analyzing model QPF with a convective event will get you nowhere fast. Link to comment Share on other sites More sharing options...
psv88 Posted July 25, 2012 Share Posted July 25, 2012 The NAM and GFS have differences which will obviously have a big impact on the forecast...but yes I think the activity with the elevated convection along the WAA/WF should be to our north over Central NY/New England. The NAM has it farther south...clipping parts of Northeast PA/Southeast NY. The NAM is also about 50-100 miles farther south with the 582dm height line at 15-18z than the GFS. The NAM has been insistent on developing an MCS over Northern PA/Southern NY and tracking it east/southeast along this gradient...into 40+kts of effective shear and high instability over N NJ/SE NY/NYC/etc. All things to watch carefully overnight tonight w/ forecast models and early tomorrow with mesoscale forecasting. P.S- Over-analyzing model QPF with a convective event will get you nowhere fast. Thanks for the analysis. Tommorow should be interesting to say the least. Link to comment Share on other sites More sharing options...
Amped Posted July 25, 2012 Share Posted July 25, 2012 GFS is pretty far north but it doesn't handle outflow boundries and storm relative motion too well. So If I had to guess the storms form where the GFS says and then propogate southeast. Central NJ maybe pushing it although it will reach there overnight. Link to comment Share on other sites More sharing options...
psv88 Posted July 26, 2012 Share Posted July 26, 2012 RAP keeps the area, other than CT, dry through 1 pm. CT gets scraped by the southern part of the MCS around 9-11 am Link to comment Share on other sites More sharing options...
earthlight Posted July 26, 2012 Author Share Posted July 26, 2012 RAP keeps the area, other than CT, dry through 1 pm. CT gets scraped by the southern part of the MCS around 9-11 am This is going to be a late-developing event in our area most likely..the models don't have the best set up for getting severe convection here until after 6-7pm. Link to comment Share on other sites More sharing options...
psv88 Posted July 26, 2012 Share Posted July 26, 2012 This is going to be a late-developing event in our area most likely..the models don't have the best set up for getting severe convection here until after 6-7pm. Thats what i was thinking. Looks like 7-9 could be the timeframe when it lights up. GFS has a ton of rain this weekend, good chance of storms friday, saturday and saturday night. Mid week next week looks pretty stormy as well. Link to comment Share on other sites More sharing options...
earthlight Posted July 26, 2012 Author Share Posted July 26, 2012 http://www.nyalert.gov/Public/News/AllHazPRView.aspx?notID=3674081&refer=HOME&source=WEB&messageID=AghxO4T6A& Link to comment Share on other sites More sharing options...
blizzardof09 Posted July 26, 2012 Share Posted July 26, 2012 http://www.nyalert.g...geID=AghxO4T6A that is a pretty big step dont you think earthlight? atleast there taking this threat seriously for tommorow Link to comment Share on other sites More sharing options...
nycsnow Posted July 26, 2012 Share Posted July 26, 2012 http://www.nyalert.gov/Public/News/AllHazPRView.aspx?notID=3674081&refer=HOME&source=WEB&messageID=AghxO4T6A& Man thats wild, haven't seen that since Irene Link to comment Share on other sites More sharing options...
blizzardof09 Posted July 26, 2012 Share Posted July 26, 2012 Man thats wild, haven't seen that since Irene given the fact we never had a moderate 2 days out from SPC and the way the models are showing how the main show in the evening may be this was a good step. further north not immediate NYC area have the best shot at the tornado threat, but im willing to be when all is said and done tommorow there will be alot of reports of wind damage and hail reports. Link to comment Share on other sites More sharing options...
ag3 Posted July 26, 2012 Share Posted July 26, 2012 Srefs with a decent shift south with the heaviest axis of precip for tomorrow evening. Good to see. Link to comment Share on other sites More sharing options...
nycsnow Posted July 26, 2012 Share Posted July 26, 2012 given the fact we never had a moderate 2 days out from SPC and the way the models are showing how the main show in the evening may be this was a good step. further north not immediate NYC area have the best shot at the tornado threat, but im willing to be when all is said and done tommorow there will be alot of reports of wind damage and hail reports. Yeah I had trees down in my neighborhood last week and it wasn't that bad, tomorrow may just be insane. I hope the 10&11pm news don't down play it. Just warn the public I'd rather be wrong then have people not knowing. Link to comment Share on other sites More sharing options...
Nikolai Posted July 26, 2012 Share Posted July 26, 2012 No comparisons to Irene, please. I was in DC for the derecho last month as well as the derecho in '08 and both blew Irene out of the water (so did Isabel). NYC has sucked for severe weather so I'm pessimistic, but the best storms I've seen in my four years here were the ones the other day that kept rebuilding over Manhattan. Crossing my fingers for a legit derecho. Link to comment Share on other sites More sharing options...
IsentropicLift Posted July 26, 2012 Share Posted July 26, 2012 When I read that the hair stood up on the back of my neck, I think some of us may get more than we bargained for, seriously. Link to comment Share on other sites More sharing options...
blizzardof09 Posted July 26, 2012 Share Posted July 26, 2012 When I read that the hair stood up on the back of my neck, I think some of us may get more than we bargained for, seriously. most likely north but not by much will the most intense storms be, but i think by tommorow morning we'll have a pretty good idea whos gonna get whacked with some storms. i cant believe the step taken by cuomo though by publishing that statement. the news stations prolly arent gonna hype it, id actually bet they wont. Link to comment Share on other sites More sharing options...
nycsnow Posted July 26, 2012 Share Posted July 26, 2012 No comparisons to Irene, please. I was in DC for the derecho last month as well as the derecho in '08 and both blew Irene out of the water (so did Isabel). NYC has sucked for severe weather so I'm pessimistic, but the best storms I've seen in my four years here were the ones the other day that kept rebuilding over Manhattan. Crossing my fingers for a legit derecho. Just meant in terms of the strong wording from officials. Not the storm itself Link to comment Share on other sites More sharing options...
psv88 Posted July 26, 2012 Share Posted July 26, 2012 Srefs with a decent shift south with the heaviest axis of precip for tomorrow evening. Good to see. Strange, slows down the precip in the evening alot, has it lingering until early morning friday and then has almost no storms on friday evening. Morning MCS is still shown well north of the metro, taking the heart of it into northern vermont, but also much later...keeping it up there until like 2-3 pm... The timing on the SREFS is just so slow, keeps the heavy precip in the area until like 2 am...according to SREFS wed be getting hit from 8-2...6 hours... Link to comment Share on other sites More sharing options...
Quincy Posted July 26, 2012 Share Posted July 26, 2012 That line over Michigan has me mildly intrigued. It will be interesting to see what it does. Trajectory is right towards central/southern NY. Link to comment Share on other sites More sharing options...
nycsnow Posted July 26, 2012 Share Posted July 26, 2012 That line over Michigan has me mildly intrigued. It will be interesting to see what it does. Trajectory is right towards central/southern NY. Dr Forbes just showed it, says it breaks up when it gets through nys due to drier air Link to comment Share on other sites More sharing options...
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