Superstorm93 Posted July 25, 2012 Share Posted July 25, 2012 Just for kicks...9z SREF probs of Derecho Param > 3 Starting to think that the SPC will have to highlight a potential significant wind threat for our area with at least an isolated chance of tornadoes. Haven't seen a decent MCS in years around here. Link to comment Share on other sites More sharing options...
earthlight Posted July 25, 2012 Share Posted July 25, 2012 Much more impressive run for Northern NJ, Southeast NY, NYC and vicinity with the NAM now bringing the MCS into the area between 21 and 03z and the surface low near just south of Albany. Link to comment Share on other sites More sharing options...
IsentropicLift Posted July 25, 2012 Share Posted July 25, 2012 I would like to add that the MCS that came through south Jersey and the Mid-Atlantic a few weeks ago which caused the derecho came through my area around midnight, in other words well after dark. The entire area had been baking in the sun all day and at that hour SBCAPE values were still very high. In other words, don't be discouraged just because we might have to wait until after sunset. In some aspects it may allow us to reach our maximum amount of destabilization. Link to comment Share on other sites More sharing options...
earthlight Posted July 25, 2012 Share Posted July 25, 2012 Seems like there are 2 triggers. The 1st one is for well north of the area but then the MCS rolls through here tomorrow evening and brings NYC and north into the game. Well, technically there are two "events" but I wouldn't call them triggers. The first one is a (likely somewhat elevated) MCS that moves through Central New England early tomorrow morning along the warm front. I wouldn't be surprised to see some severe reports with this but it will likely decay by 18z-21z. The second is more cold front/height fall triggered back to our west over the OV...and we're sitting pretty along a mid level height gradient and baroclinic zone. With the surface low to our north over Albany and the mid level trough back to our west, we'll be underneath a plume of favorable 0-6km shear as well as low level shear and helicity...which is why you're seeing some high tornado probability numbers especially to our north and west on the NAM and SREF. But for our area, if we can develop an MCS that can ride the gradient, it should guide it directly through SE NY/N NJ including the NYC area...with the NAM indicating 3000 joules of cape over parts of NJ at 00z Thursday and 40 kts of effective shear..it shouldn't have trouble maintaining the potential for widespread damaging winds. Edit: just saw Jake already responded with a similar idea. Link to comment Share on other sites More sharing options...
Superstorm93 Posted July 25, 2012 Share Posted July 25, 2012 Very impressive 12z NAM Tornado potential just got a nice uptick in my book. Any thoughts from the pros? SBCAPE 0-3km EHI (Stays the same for 6 hours over the region!) Link to comment Share on other sites More sharing options...
NJwinter23 Posted July 25, 2012 Share Posted July 25, 2012 Check out the serious backing surface winds across Hudson Valley/W. CT at 3z Fri, verbatim on the nam Link to comment Share on other sites More sharing options...
TheTrials Posted July 25, 2012 Share Posted July 25, 2012 pretty scary looking numbers. Hope people are becoming aware of the raw potential here. Watching the early news today before my morning tee time, didn't really get the impression the severe potential was being hit too hard. Hopefully that changes tonight and tomorrow morning. Link to comment Share on other sites More sharing options...
Isotherm Posted July 25, 2012 Share Posted July 25, 2012 The entire metro area is still very much in the game for severe weather, as far south as PHL. Thermodynamic parameters are impressive with 2500+ CAPE, bulk effective shear of 30-40kts across NJ/NYC, and helicity values up near 3 for late Thursday afternoon. Still think highest supercell risk is NE PA/S NY and western New England. Link to comment Share on other sites More sharing options...
IsentropicLift Posted July 25, 2012 Share Posted July 25, 2012 The radio just mentioned a chance of "typical summer thunderstorms". They will downplay it until the storms are in progress. Link to comment Share on other sites More sharing options...
Dsnowx53 Posted July 25, 2012 Share Posted July 25, 2012 Wow, some of the data from the NAM seems to support a tornado threat around 3z as well? That kinda makes sense considering the H5 setup looks a little better. Still though it's increasingly likely that we may see supercells and perhaps tornadoes to our north. I wouldn't worry about instability being a tad lower or whatever...it still looks just fine to me and I would sacrifice a bit of CAPE for more shear, low level helicity, and lower LCL heights. We have plenty of CAPE to work with and 2500J/KG should get the job done. Link to comment Share on other sites More sharing options...
Superstorm93 Posted July 25, 2012 Share Posted July 25, 2012 This is actually a pretty darn nastly looking sounding from EWR at 00z Friday. Some of these numbers are crazy... Link to comment Share on other sites More sharing options...
Stormlover74 Posted July 25, 2012 Share Posted July 25, 2012 As they should more than 24 hours out...though they might have mentioned that some of the storms could be severe as they usually do The radio just mentioned a chance of "typical summer thunderstorms". They will downplay it until the storms are in progress. Link to comment Share on other sites More sharing options...
IsentropicLift Posted July 25, 2012 Share Posted July 25, 2012 As they should more than 24 hours out...though they might have mentioned that some of the storms could be severe as they usually do That is exactly what I was getting at. I wouldn't have said typical summer storms though. I would have said strong storms with the potential for gusty winds. I don't think a bit of strong wording is out of the question. The thing is, the main weather guy (Mr. G) is on vacation this week so I wonder what they are using. Link to comment Share on other sites More sharing options...
LocoAko Posted July 25, 2012 Share Posted July 25, 2012 LCL heights are a little high for the NYC area to see anything tornadic until after 00Z, but as of 9PM on Thursday they fall to ~1300 m with CAPE in excess of 3000 J/kg, 0-3 km SRH values around 300 m2/s2, a SWEAT of 352 and an EHI of 5.75. Bulk Richardson numbers also fall to around 40 in this time frame. 7-10PM looks to be the greatest threat in the immediate NYC metro area if anything surface-based can get going and advect into the area. Link to comment Share on other sites More sharing options...
NJwinter23 Posted July 25, 2012 Share Posted July 25, 2012 LCL heights are a little high for the NYC area to see anything tornadic until after 00Z, but as of 9PM on Thursday they fall to ~1300 m with CAPE in excess of 3000 J/kg, 0-3 km SRH values around 300 m2/s2, a SWEAT of 352 and an EHI of 5.75. Bulk Richardson numbers also fall to around 40 in this time frame. 7-10PM looks to be the greatest threat in the immediate NYC metro area if anything surface-based can get going and advect into the area. I was just going to post about the LCL's...That's another parameter where heading a little further northeast, perhaps sacrificing a little CAPE as Doug put it, can improve things...Its a fine boundary of elements that i'm sure we won't know exactly where it lines up until the hour of Link to comment Share on other sites More sharing options...
LocoAko Posted July 25, 2012 Share Posted July 25, 2012 Big if here, but if a sustained supercell could get itself going and turn right of the mean wind (from about 250° to 280°) around 9PM it'd increase our 0-1 km SRH values to over 160 m2/s2 and our 0-3 km SRH values to in excess of 300 m2/s2. (Can anyone tell I just learned how to modify the hodograph in BUFKIT? ). That'd be exciting. If only 500 hPa winds were a bit stronger... Link to comment Share on other sites More sharing options...
Allsnow Posted July 25, 2012 Share Posted July 25, 2012 Ag3 is the man...but he made me think we are getting nothing.....does this look like late afternoon sun event? Link to comment Share on other sites More sharing options...
ag3 Posted July 25, 2012 Share Posted July 25, 2012 Ag3 is the man...but he made me think we are getting nothing.....does this look like late afternoon sun event? Made the mistake of not pointing out I was talking about the morning stuff. The evening/MCS stuff looks great as the great posters for convection have pointed out. Link to comment Share on other sites More sharing options...
Allsnow Posted July 25, 2012 Share Posted July 25, 2012 Made the mistake of not pointing out I was talking about the morning stuff. The evening/MCS stuff looks great as the great posters for convection have pointed out. Thanks bud...right now the middlesex crew will be smoking anvils again...seems about right Link to comment Share on other sites More sharing options...
Isotherm Posted July 25, 2012 Share Posted July 25, 2012 Thanks bud...right now the middlesex crew will be smoking anvils again...seems about right Yeah I'm a bit concerned we're too far SE of the height falls/associated forcing to see big time convection but we're still very much in the game. I'm not crazy about events that take until after 7pm to get into our area as they usually die out. However, this particular event will feature more conducive dynamics thurs eve than during the afternoon, so hopefully we can maintain that convection into CNJ. Link to comment Share on other sites More sharing options...
OSUmetstud Posted July 25, 2012 Share Posted July 25, 2012 Big if here, but if a sustained supercell could get itself going and turn right of the mean wind (from about 250° to 280°) around 9PM it'd increase our 0-1 km SRH values to over 160 m2/s2 and our 0-3 km SRH values to in excess of 300 m2/s2. (Can anyone tell I just learned how to modify the hodograph in BUFKIT? ). That'd be exciting. If only 500 hPa winds were a bit stronger... on the hodograph, drag the orange storm motion vector downward for a right turner. You have to click on the intersection of the orange storm motion vector and the 2 blue vectors that are calculating the area of the wind graph for helicity. edit: I misread your post. I thought you were asking how to lol. Link to comment Share on other sites More sharing options...
LocoAko Posted July 25, 2012 Share Posted July 25, 2012 on the hodograph, drag the orange storm motion vector downward for a right turner. You have to click on the intersection of the orange storm motion vector and the 2 blue vectors that are calculating the area of the wind graph for helicity. edit: I misread your post. I thought you were asking how to lol. No worries. Link to comment Share on other sites More sharing options...
rcad1 Posted July 25, 2012 Share Posted July 25, 2012 This might be a dumb question but I see Upton is forecasting my area to have a South wind in the afternoon Thursday wouldn't this hurt my chances of seeing severe weather cause the marine layer will stabilize us???, Link to comment Share on other sites More sharing options...
andyhb Posted July 25, 2012 Share Posted July 25, 2012 This might be a dumb question but I see Upton is forecasting my area to have a South wind in the afternoon Thursday wouldn't this hurt my chances of seeing severe weather cause the marine layer will stabilize us???, Depends on where you are located... Link to comment Share on other sites More sharing options...
rcad1 Posted July 25, 2012 Share Posted July 25, 2012 Sorry im located in western Nassau county on the island more specific Im located by mineola just South of the northern state pkwy so im not the South shore witch is good I guess but im still on the island witch is bad Im gathering by other post Link to comment Share on other sites More sharing options...
forkyfork Posted July 25, 2012 Share Posted July 25, 2012 As long as something can organize in w/central pa we will get something. Whatever initiates will roll to the coast easily Link to comment Share on other sites More sharing options...
earthlight Posted July 25, 2012 Share Posted July 25, 2012 Holy crap, a huge Day 2 Moderate Risk! Link to comment Share on other sites More sharing options...
andyhb Posted July 25, 2012 Share Posted July 25, 2012 Wow... Link to comment Share on other sites More sharing options...
Superstorm93 Posted July 25, 2012 Share Posted July 25, 2012 Holy @#$!! Totally was not expecting that. Link to comment Share on other sites More sharing options...
LocoAko Posted July 25, 2012 Share Posted July 25, 2012 ...SYNOPSIS... VIGOROUS SHORT WAVE TROUGH OVER THE SRN CANADIAN PRAIRIES WILL MOVE SEWD AND REACH THE UPPER GREAT LAKES BY EARLY FRI...WITH A MODERATELY FAST ZONAL FLOW REGIME EXISTING DOWNSTREAM ACROSS THE NERN CONUS. AT THE SURFACE...A WARM FRONT WILL ADVANCE NEWD IN THE NORTHEAST AND SHOULD REMAIN QUASI-STATIONARY ACROSS THE CNTRL GREAT LAKES. A SERIES OF WEAK CYCLONES SHOULD BE PREVALENT ALONG THIS BOUNDARY...WHICH WILL INTERSECT A SLOW-MOVING COLD FRONT MOVING SEWD FROM THE MID-MS VALLEY TO THE SRN PLAINS. IN THE WEST...MID-LEVEL RIDGING WILL BUILD FROM THE SOUTHWEST ACROSS THE INTERMOUNTAIN WEST. ...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...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.