Mikehobbyst Posted June 14, 2014 Share Posted June 14, 2014 Looking at the ECMWF, GGEM, and GFS models and averaging everything out: CAPE = 2500-3500 - scattered severe LI = -6 and -8 - very unstable Shear = 35-45 knot - favorable too Temp 88 Dew point 75 Favorable jet region placement 925 temp 24 C 850 mb temp 17 C 700 mb temp 7-8 C - weak EML looks present. 300 mb winds 35-45 knts WNW flow (SVR derecho is a slight risk) 500 mb winds 35 knts - WNW flow with energy EML= weak one present - may push this to strong SLGT risk SVR event If we had better low and mid level lapse rates it could be a moderate risk type of day. One other thing of concern is cloud debris and any earlier convection. Wednesday is looking most favorable for scattered severe, and isolated significant severe. My guess on probabilities like SPC for 6/18: Wind: 30 percent on the cusp to possible small hatched 45 percent area just west of NYC. Hail: 15 percent Tornado: 5 percent This looks better than anything we had last year, and better than yesterday 6/13. Thursday through Saturday look backdoorish again... We may have our first significant 4-5 day east coast heat ridge from 6/22 to 6/27, with first 90 maybe likely. Please comment... Link to comment Share on other sites More sharing options...
NEG NAO Posted June 15, 2014 Share Posted June 15, 2014 This looks like a credible threat Wednesday the 18th for severe weather - should also be the first real Hot day for just about everyone reaching 90 with heat indicies above 90- still have to wait and see if the immediate coast/beaches reach 90 http://kamala.cod.edu/nj/latest.fxus61.KOKX.html Link to comment Share on other sites More sharing options...
Superstorm93 Posted June 15, 2014 Share Posted June 15, 2014 Upton not too gung-ho on a big severe threat EXPECT ANOTHER MCS TO POSSIBLY IMPACT THE AREA TUESDAY NIGHT...FOLLOWED BY A COLD FRONT PUSHING THROUGH LATE WEDNESDAY. HAVE SLIGHT CHANCE POPS TUESDAY NIGHT...THEN CHANCE POPS WEDNESDAY AS A RESULT. ANY THUNDERSTORMS AHEAD OF THE COLD FRONT ON WEDNESDAY COULD BE STRONG TO SEVERE WITH 1500-2500 J/KG OF CAPE...THE PASSING OF A 25-30 KT LOW LEVEL JET JUST TO THE S...20-30 KT OF 0-6 KM SHEAR AND 1000-1250 J/KG OF DOWNDRAFT CAPE. A LIMITING FACTOR THOUGH IS THE HIGH CAPE TO SHEAR RATIO YIELDS BULK RICHARDSON NUMBERS GENERALLY OF 80+ WHICH FAVORS ALMOST EXCLUSIVELY PULSE CONVECTION. Link to comment Share on other sites More sharing options...
IntenseBlizzard2014 Posted June 15, 2014 Share Posted June 15, 2014 The CAPE looks to be the highest for the Southern Mid Atlantic. So any thunderstorms for the Tri State will be isolated/scattered, due to the lower instability for the area. Link to comment Share on other sites More sharing options...
REDMK6GLI Posted June 15, 2014 Share Posted June 15, 2014 Upton not too gung-ho on a big severe threat They are probably right, how many advertised severe threats have we seen materialize from NJ/PA all the way into LI the past several severe seasons? Probably just end up being severe storms away from NYC with scattered showers/storms NYC-East. Thats my honest opinion.... Link to comment Share on other sites More sharing options...
Stormlover74 Posted June 15, 2014 Share Posted June 15, 2014 They are probably right, how many advertised severe threats have we seen materialize from NJ/PA all the way into LI the past several severe seasons? Probably just end up being severe storms away from NYC with scattered showers/storms NYC-East. Thats my honest opinion.... I may have heard you mention it once or twice Link to comment Share on other sites More sharing options...
REDMK6GLI Posted June 16, 2014 Share Posted June 16, 2014 I may have heard you mention it once or twice people think im a debbie downer but this is just from experience. My location is literally a convective graveyard. Has its own local microclimate, the other day when that line of storms came through i got a three minute downpour with no lightning/ thunder Link to comment Share on other sites More sharing options...
IsentropicLift Posted June 16, 2014 Share Posted June 16, 2014 people think im a debbie downer but this is just from experience. My location is literally a convective graveyard. Has its own local microclimate, the other day when that line of storms came through i got a three minute downpour with no lightning/ thunderPeople are tired of hearing about it. It's the same thing every day. Link to comment Share on other sites More sharing options...
NEG NAO Posted June 16, 2014 Share Posted June 16, 2014 The CAPE looks to be the highest for the Southern Mid Atlantic. So any thunderstorms for the Tri State will be isolated/scattered, due to the lower instability for the area. things can still change either way - good idea to keep an open mind 3 days out - once again wouldn't surprise me if there are flash flood watches and warnings along with severe T- Storm watches and warnings issued once again Link to comment Share on other sites More sharing options...
Weathergun Posted June 16, 2014 Share Posted June 16, 2014 The best chance of strong or severe t-storms is where we see forcing, instability,etc come together. We also might have pocket of enhanced shear with the shortwave passing over the area Wed afternoon: Link to comment Share on other sites More sharing options...
jm1220 Posted June 16, 2014 Share Posted June 16, 2014 people think im a debbie downer but this is just from experience. My location is literally a convective graveyard. Has its own local microclimate, the other day when that line of storms came through i got a three minute downpour with no lightning/ thunder It actually made it to Nassau County in pretty good shape. I wasn't home at the time but the storms were pretty intense from what I was told. I'm surprised it all made it beyond the seabreeze line. Link to comment Share on other sites More sharing options...
REDMK6GLI Posted June 16, 2014 Share Posted June 16, 2014 The best chance of strong or severe t-storms is where we see forcing, instability,etc come together. We also might have pocket of enhanced shear with the shortwave passing over the area Wed afternoon: Shear6zGFS.png 500mb6zGFS.png Currently SVR parameters look pretty good today for our area including LI. However still south of us from CNJ on south has the best chance for more organzied convection. Instability doesnt look an issue area wide at all but we'll also have to keep an eye on the mid-level lapse rates as well.... Link to comment Share on other sites More sharing options...
Weathergun Posted June 16, 2014 Share Posted June 16, 2014 Currently SVR parameters look pretty good today for our area including LI. However still south of us from CNJ on south has the best chance for more organzied convection. Instability doesnt look an issue area wide at all but we'll also have to keep an eye on the mid-level lapse rates as well.... We'll have to see where our triggering mechanisms wind up. There will be some cap in place that might limit areal coverage. The GFS at least, still has steep mid-level lapse rates. West winds should keep sea-breezes from pushing inland.The NAM and ECMWF also seem to be showing some better instability and shear parameters this morning. I'm optimistic. But there is still a few days for timing and parameters to change here. Link to comment Share on other sites More sharing options...
IsentropicLift Posted June 16, 2014 Share Posted June 16, 2014 Per NWS discussion activity should make it into the region after dark. Biggest limiting factor looks to be waning instability. An embedded shortwave is forecasted to cross the region overnight and act as a triggering mechanism. On Tuesday, despite increased instability the atmosphere is forecasted to be capped at the mid-levels. The cap then erodes late in the day as an MCS or convective feature crosses the region. In my opinion Wednesday looks to be the best chance at severe with a potent shortwave crossing the region, ample instability and good lapse rates. Limiting factor would be timing which is still an unknown. Link to comment Share on other sites More sharing options...
Frank Posted June 17, 2014 Share Posted June 17, 2014 Wednesday should be interesting Link to comment Share on other sites More sharing options...
NEG NAO Posted June 17, 2014 Share Posted June 17, 2014 Per NWS discussion activity should make it into the region after dark. Biggest limiting factor looks to be waning instability. An embedded shortwave is forecasted to cross the region overnight and act as a triggering mechanism. On Tuesday, despite increased instability the atmosphere is forecasted to be capped at the mid-levels. The cap then erodes late in the day as an MCS or convective feature crosses the region. In my opinion Wednesday looks to be the best chance at severe with a potent shortwave crossing the region, ample instability and good lapse rates. Limiting factor would be timing which is still an unknown. to better explain that the biggest possible limiting factor in the immediate metro late tonight is the marine layer with the onshore flow expected Tomorrow should be a fun day for severe enthusiasts ........... Link to comment Share on other sites More sharing options...
Weathergun Posted June 17, 2014 Share Posted June 17, 2014 Sudden slight risk upgrade for tonight. High winds main threat: ...LWR MI/GRT LKS TODAY INTO TNGT... BAND OF SEASONABLY STRONG /40-50 KT/...LARGELY UNIDIRECTIONAL WSWLY FLOW ON SRN FRINGE OF LK MI UPR IMPULSE WILL SWEEP E INTO THE LWR GRT LKS/WRN NEW ENGLAND BY EARLY TNGT...ACCOMPANIED BY AN APPRECIABLE INCREASE IN MOISTURE /PW 1.50-1.75 INCHES/. LOW-LVL CONVERGENCE ACROSS REGION WILL REMAIN WEAK...DOMINATED BY LAKE BREEZE BOUNDARIES IN UPSTATE NY/NW PA AND...POSSIBLY...BY CONVECTIVE OUTFLOW IN LWR MI. COMBINATION OF MODERATE TO STRONG SFC HEATING /ESPECIALLY IN NY/ WITH INCREASING MOISTURE SHOULD BOOST SBCAPE TO BETWEEN 1500 AND 2500 J/KG. COUPLED WITH EXPECTED LOW TO MID-TROPOSPHERIC WIND PROFILES...SETUP MAY PROVE FAVORABLE FOR STORMS ORGANIZED INTO FAST-MOVING...FORWARD-PROPAGATING LINE SEGMENTS WITH DMGG WIND. WHILE THE GREATEST SVR THREAT SHOULD EXIST FROM SE LWR MI EWD THROUGH SW ON INTO NW PA AND UPSTATE NY THROUGH THIS AFTN...A MORE LIMITED THREAT FOR SVR WEATHER MAY CONTINUE INTO THIS EVE AS FAR E/SE AS NJ AND SRN NEW ENGLAND. Link to comment Share on other sites More sharing options...
user13 Posted June 17, 2014 Share Posted June 17, 2014 Sudden slight risk upgrade for tonight. High winds main threat:...LWR MI/GRT LKS TODAY INTO TNGT... BAND OF SEASONABLY STRONG /40-50 KT/...LARGELY UNIDIRECTIONAL WSWLY FLOW ON SRN FRINGE OF LK MI UPR IMPULSE WILL SWEEP E INTO THE LWR GRT LKS/WRN NEW ENGLAND BY EARLY TNGT...ACCOMPANIED BY AN APPRECIABLE INCREASE IN MOISTURE /PW 1.50-1.75 INCHES/. LOW-LVL CONVERGENCE ACROSS REGION WILL REMAIN WEAK...DOMINATED BY LAKE BREEZE BOUNDARIES IN UPSTATE NY/NW PA AND...POSSIBLY...BY CONVECTIVE OUTFLOW IN LWR MI. COMBINATION OF MODERATE TO STRONG SFC HEATING /ESPECIALLY IN NY/ WITH INCREASING MOISTURE SHOULD BOOST SBCAPE TO BETWEEN 1500 AND 2500 J/KG. COUPLED WITH EXPECTED LOW TO MID-TROPOSPHERIC WIND PROFILES...SETUP MAY PROVE FAVORABLE FOR STORMS ORGANIZED INTO FAST-MOVING...FORWARD-PROPAGATING LINE SEGMENTS WITH DMGG WIND. WHILE THE GREATEST SVR THREAT SHOULD EXIST FROM SE LWR MI EWD THROUGH SW ON INTO NW PA AND UPSTATE NY THROUGH THIS AFTN...A MORE LIMITED THREAT FOR SVR WEATHER MAY CONTINUE INTO THIS EVE AS FAR E/SE AS NJ AND SRN NEW ENGLAND. Lets go! Link to comment Share on other sites More sharing options...
user13 Posted June 17, 2014 Share Posted June 17, 2014 HRRR looks to keep most of the action to the north so far. Link to comment Share on other sites More sharing options...
bluewave Posted June 17, 2014 Share Posted June 17, 2014 HRRR looks to keep most of the action to the north so far. Looks to be in the Euro camp so far with best potential north of NYC. We'll see if later runs can edge a little further south closer to us. Link to comment Share on other sites More sharing options...
user13 Posted June 17, 2014 Share Posted June 17, 2014 Looks to be in the Euro camp so far with best potential north of NYC. We'll see if later runs can edge a little further south closer to us. North32America_msl_24.gif Yea if the complex develops nicely they like so sag south. SPC seems to be too south with their forecast as modeled now. Link to comment Share on other sites More sharing options...
Weathergun Posted June 17, 2014 Share Posted June 17, 2014 The 12z RAP has a weakening MCS moving through NYC area around midnight. It's out of it's good range though. Link to comment Share on other sites More sharing options...
IsentropicLift Posted June 17, 2014 Share Posted June 17, 2014 As others have mentioned, MCS's almost always travel NW to SE. Also you would want to be towards the southeast corner to have the best chance of severe. Link to comment Share on other sites More sharing options...
IsentropicLift Posted June 17, 2014 Share Posted June 17, 2014 Timing for tomorrow looks rough. Looks like it comes in between 12z and 18z. Link to comment Share on other sites More sharing options...
NEG NAO Posted June 17, 2014 Share Posted June 17, 2014 As others have mentioned, MCS's almost always travel NW to SE. Also you would want to be towards the southeast corner to have the best chance of severe. ???? 1998 Labor Day MCS traveled mailnly west to slightly southeast so your statement is not correct unfortunately http://www.spc.noaa.gov/misc/AbtDerechos/casepages/sep71998page.htm Link to comment Share on other sites More sharing options...
IsentropicLift Posted June 17, 2014 Share Posted June 17, 2014 ???? 1998 Labor Day MCS traveled mailnly west to slightly southeast so your statement is not correct unfortunately http://www.spc.noaa.gov/misc/AbtDerechos/casepages/sep71998page.htm You're joking right? Link to comment Share on other sites More sharing options...
NEG NAO Posted June 17, 2014 Share Posted June 17, 2014 You're joking right? look at this map of the entire event and tell me if that is a true northwest to southeast movement from beginning to end - next tell me the main directional movement from beginning to end using the curved lines http://www.spc.noaa.gov/misc/AbtDerechos/casepages/sep71998page.htm Link to comment Share on other sites More sharing options...
Stormlover74 Posted June 17, 2014 Share Posted June 17, 2014 look at this map of the entire event and tell me if that is a true northwest to southeast movement from beginning to end - next tell me the main directional movement from beginning to end using the curved lines http://www.spc.noaa.gov/misc/AbtDerechos/casepages/sep71998page.htm Its one event, which was a derecho. I think he was talking about general MCS' which usually tend to move from the NW and dive ESE Link to comment Share on other sites More sharing options...
IsentropicLift Posted June 17, 2014 Share Posted June 17, 2014 look at this map of the entire event and tell me if that is a true northwest to southeast movement from beginning to end - next tell me the main directional movement from beginning to end http://www.spc.noaa.gov/misc/AbtDerechos/casepages/sep71998page.htm Since when is one event a proper example for all? Look back to the 2012 mid-atlantic derecheo, clearly NW to SE? It's a known fact that stronger convection turns right. Link to comment Share on other sites More sharing options...
IsentropicLift Posted June 17, 2014 Share Posted June 17, 2014 From http://link.springer.com/article/10.1007%2FBF01592957 Abstract Migration velocities of convective storms are summarized for six situations, with different environmental wind fields. Small-and medium-sized storms generally moved to left of the direction of, and at speeds somewhat less than, the vector mean wind in the troposphere. Large-diameter (ca. 20–30 km) storms generally deviated to the right, in proportion to their sizes and to the veering of wind with height. This behavior, and the tendency for large storms to move appreciably slower than the mean wind, are even more pronounced when giant clusters of thunderstorms are considered. An example is analyzed in which a multicellular storm, 80 km wide, moved 55° to right of the mean wind and with half its speed. This behavior results from a characteristic pattern of propagation, in which new cells tend to form on the general upwind side of the cluster, with the larger and more intense cells developing on its right flank. The individual cells move through the cluster, dissipating on approach to its advancing and left flanks. Preferential formation of cells toward the rear side of the cluster is shown to be compatible with the probable origin and trajectories (relative to the moving storm) of air ascending from the lower part of the subcloud layer. The sometimes-observed rapid movement of large multicellular storms to left of the mean wind is partly accounted for by an opposite (left forward flank) pattern of propagation. Link to comment Share on other sites More sharing options...
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