Ellinwood Posted August 9, 2012 Share Posted August 9, 2012 ...SRN/CNTRL APPALACHIAN REGION THROUGH MID ATLANTIC AND A PORTION OF NERN STATES... STORMS WILL LIKELY BE ONGOING ALONG AND JUST AHEAD OF THE COLD FRONT WITHIN WARM CONVEYOR BELT ACROSS PORTIONS OF THE TN AND OH VALLEYS WITH GREATEST COVERAGE EXPECTED WEST OF THE APPALACHIANS. UPPER 60S TO NEAR 70 DEWPOINTS WILL RESIDE IN PRE-FRONTAL WARM SECTOR. DIABATIC WARMING OUTSIDE OF CLOUDY AREAS WILL DESTABILIZE THE BOUNDARY LAYER...BUT WEAK MID LEVEL LAPSE RATES SHOULD TEMPER INSTABILITY SOMEWHAT WITH MLCAPE GENERALLY AOB 1500 J/KG. STORMS SHOULD INCREASE IN COVERAGE AND INTENSITY AHEAD OF THE COLD FRONT DURING THE DAY...LIKELY EVOLVING INTO LINES AND CLUSTERS...THOUGH A FEW DISCRETE CELLS WILL ALSO POSSIBLE. VERTICAL SHEAR IN MOST OF WARM SECTOR WILL NOT BE PARTICULARLY STRONG OWING TO THE EQUIVALENT BAROTROPIC NATURE OF THE UPPER LOW. EXPECTED MARGINAL THERMODYNAMIC ENVIRONMENT AND MODEST VERTICAL SHEAR COULD SERVE AS POSSIBLE LIMITING FACTORS FOR A MORE ROBUST SEVERE THREAT. SOMEWHAT STRONGER DEEP AND LOW LEVEL SHEAR MAY DEVELOP FROM NRN MID ATLANTIC INTO ERN PORTION OF THE OH VALLEY AND NERN STATES IN ASSOCIATION WITH A MID LEVEL JET ROTATING THROUGH SERN PERIPHERY OF THE UPPER LOW. IF SUFFICIENT INSTABILITY DEVELOPS...STORMS MAY BECOME A BIT MORE ORGANIZED IN THIS REGION WITH POTENTIAL FOR EMBEDDED MESOCYCLONES AND BOWING SEGMENTS. DAMAGING WIND WILL BE THE MAIN THREAT...BUT A CONDITIONAL THREAT WILL EXIST FOR A COUPLE OF TORNADOES. Link to comment Share on other sites More sharing options...
H2O Posted August 9, 2012 Share Posted August 9, 2012 EXPECTED MARGINAL THERMODYNAMIC ENVIRONMENT AND MODEST VERTICAL SHEAR COULD SERVE AS POSSIBLE LIMITING FACTORS FOR A MORE ROBUST SEVERE THREAT DC always finds a way to make this part happen Link to comment Share on other sites More sharing options...
Ian Posted August 9, 2012 Share Posted August 9, 2012 I expect a broad 2% with a 5% somewhere for now Link to comment Share on other sites More sharing options...
Kmlwx Posted August 9, 2012 Share Posted August 9, 2012 I expect a broad 2% with a 5% somewhere for now Are you leaning towards that 5% being into PA at this point? I know that's where the SREF was leaning in last nights 21z run. 30% wind? Link to comment Share on other sites More sharing options...
HM Posted August 9, 2012 Share Posted August 9, 2012 The 6z trends were not good so we need to see the 12z stuff really turn around. With the current data, I wouldn't go 30% wind anywhere yet. Link to comment Share on other sites More sharing options...
Ian Posted August 9, 2012 Share Posted August 9, 2012 The 6z trends were not good so we need to see the 12z stuff really turn around. With the current data, I wouldn't go 30% wind anywhere yet. I havent looked at anything yet today. Maybe I'll cancel it instead. Link to comment Share on other sites More sharing options...
Ellinwood Posted August 9, 2012 Author Share Posted August 9, 2012 Are you leaning towards that 5% being into PA at this point? I know that's where the SREF was leaning in last nights 21z run. 30% wind? I would imagine they'd put a 5% tor in north-central and northeastern PA, leaving my chase target of Gettysburg just south of the 5%. PA, western MD, WV and western VA could get 30% wind... would hold off on DC east due to timing concerns with the main line. Link to comment Share on other sites More sharing options...
Ian Posted August 9, 2012 Share Posted August 9, 2012 Are you leaning towards that 5% being into PA at this point? I know that's where the SREF was leaning in last nights 21z run. 30% wind? I would lean north of DC at least for 5 based on the past few days of guidance. Since it's conditional they might not go that high anyway... Link to comment Share on other sites More sharing options...
Kmlwx Posted August 9, 2012 Share Posted August 9, 2012 I havent looked at anything yet today. Maybe I'll cancel it instead. I guess a safe bet at this point would to be to go with a good chance of storms and a very conditional threat for interesting happenings. Maybe hype the flood risk more at this point? Link to comment Share on other sites More sharing options...
HM Posted August 9, 2012 Share Posted August 9, 2012 I havent looked at anything yet today. Maybe I'll cancel it instead. New 12z NAM beginning to come in. It is pretty awesome how unstable my area is at 9-12z tomorrow. Strong theta-e advection in the low levels and pretty ridiculous dewpoints being modeled bring the CAPE values up. Link to comment Share on other sites More sharing options...
Ellinwood Posted August 9, 2012 Author Share Posted August 9, 2012 I would lean north of DC at least for 5 based on the past few days of guidance. Since it's conditional they might not go that high anyway... This, too Being the SPC, I would think most likely scenario is starting off with 2% and then targeting the 5% in an afternoon update when the details become evident. Link to comment Share on other sites More sharing options...
Ian Posted August 9, 2012 Share Posted August 9, 2012 I guess a safe bet at this point would to be to go with a good chance of storms and a very conditional threat for interesting happenings. Maybe hype the flood risk more at this point? I think even with mostly cloudy skies we'll get some svr... that solution should still support CAPE of 1000+ across this area. Sun will really make things bubble. Link to comment Share on other sites More sharing options...
Kmlwx Posted August 9, 2012 Share Posted August 9, 2012 I think even with mostly cloudy skies we'll get some svr... that solution should still support CAPE of 1000+ across this area. Sun will really make things bubble. I'm sure at least some of us will get a couple breaks of sun - even if not much. Link to comment Share on other sites More sharing options...
Dsnowx53 Posted August 9, 2012 Share Posted August 9, 2012 I think even with mostly cloudy skies we'll get some svr... that solution should still support CAPE of 1000+ across this area. Sun will really make things bubble. Plus that keeps LCL heights lower. Link to comment Share on other sites More sharing options...
Kmlwx Posted August 9, 2012 Share Posted August 9, 2012 The low topped sups that were mentioned yesterday are probably still a decent bet. We were spoiled by the derecho... Link to comment Share on other sites More sharing options...
HM Posted August 9, 2012 Share Posted August 9, 2012 Looks like the lack of a cap, quick destabilization and favorable synoptic lift get showers/t-storms blossoming quickly over the coastal plain area (late morning). There is also a weakening but somewhat sufficient low-mid level wind max that passes through during this time as well. What a complicated mess! Link to comment Share on other sites More sharing options...
Ian Posted August 9, 2012 Share Posted August 9, 2012 Plus that keeps LCL heights lower. True... That shouldn't be among the bigger problems Link to comment Share on other sites More sharing options...
Ian Posted August 9, 2012 Share Posted August 9, 2012 Looks like the lack of a cap, quick destabilization and favorable synoptic lift get showers/t-storms blossoming quickly over the coastal plain area (late morning). There is also a weakening but somewhat sufficient low-mid level wind max that passes through during this time as well. What a complicated mess! Scattered strong storms with road ponding! While not tropical I sorta envision a remnants type of scenario. Constant moisture feed.. Potential for multiple rounds. Maybe a zone that gets fed some sun etc causing a few small supercells. Link to comment Share on other sites More sharing options...
HM Posted August 9, 2012 Share Posted August 9, 2012 Scattered strong storms with road ponding! While not tropical I sorta envision a remnants type of scenario. Constant moisture feed.. Potential for multiple rounds. Maybe a zone that gets fed some sun etc causing a few small supercells. Definitely. There could also be a zone that just escapes most rainfall sitting in between the early morning forcing and waiting for the second shot late at night. Call me crazy, but I almost want to say the NAM is signaling some type of +RN/embedded low-topped supercells tomorrow morning across the eastern Mid Atlantic. You want to come to NJ? I remember a situation like this last year where heavy rain advanced across the area morning-midday and it ended up producing an EF0 in Monmouth. Link to comment Share on other sites More sharing options...
Ian Posted August 9, 2012 Share Posted August 9, 2012 Definitely. There could also be a zone that just escapes most rainfall sitting in between the early morning forcing and waiting for the second shot late at night. Call me crazy, but I almost want to say the NAM is signaling some type of +RN/embedded low-topped supercells tomorrow morning across the eastern Mid Atlantic. You want to come to NJ? I remember a situation like this last year where heavy rain advanced across the area morning-midday and it ended up producing an EF0 in Monmouth. Certainly a messy setup... tho I suppose most of them are around here. Not sure I'm a huge fan of the newest SREF parameters. But, overall I think southern to central PA is an OK target for early afternoon on. It's possible morning activity will ruin things I suppose. Link to comment Share on other sites More sharing options...
Ian Posted August 9, 2012 Share Posted August 9, 2012 Only slight wording edits to new d2 text.. basically exactly the same. Link to comment Share on other sites More sharing options...
sauss06 Posted August 9, 2012 Share Posted August 9, 2012 Certainly a messy setup... tho I suppose most of them are around here. Not sure I'm a huge fan of the newest SREF parameters. But, overall I think southern to central PA is an OK target for early afternoon on. It's possible morning activity will ruin things I suppose. Some people are already chirping up here. you'd think were in for a blizzard the way my co-workers are talking. Link to comment Share on other sites More sharing options...
BlizzardNole Posted August 9, 2012 Share Posted August 9, 2012 Definitely. There could also be a zone that just escapes most rainfall sitting in between the early morning forcing and waiting for the second shot late at night... My parched yard and garden eagerly await their 0.15" of rain Link to comment Share on other sites More sharing options...
weathermanchild Posted August 9, 2012 Share Posted August 9, 2012 With upper level winds so weak and not expected to get noticeably stronger until tomorrow late afternoon east of the app mtns, I worry about convective debris lingering and severely limiting the instability south of central PA. Link to comment Share on other sites More sharing options...
Ian Posted August 9, 2012 Share Posted August 9, 2012 Some rotation in storms today with at least transient supercell structures from MD into NY.. maybe a good sign or a reach. Link to comment Share on other sites More sharing options...
MN Transplant Posted August 9, 2012 Share Posted August 9, 2012 Some rotation in storms today with at least transient supercell structures from MD into NY.. maybe a good sign or a reach. 450 PM EDT THU AUG 9 2012 THE NATIONAL WEATHER SERVICE IN STERLING VIRGINIA HAS ISSUED A * TORNADO WARNING FOR... SOUTHEASTERN MORGAN COUNTY IN THE PANHANDLE OF WEST VIRGINIA... NORTHWESTERN BERKELEY COUNTY IN THE PANHANDLE OF WEST VIRGINIA... * UNTIL 515 PM EDT * AT 449 PM EDT...A SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO WAS OVER WESTERN BERKELEY COUNTY...OR NEAR HIGHLAND RIDGE...AND WAS MOVING EAST AT 10 MPH. * LOCATIONS IMPACTED INCLUDE... JONES SPRINGS... TOMAHAWK... JOHNSONTOWN... Link to comment Share on other sites More sharing options...
Ian Posted August 9, 2012 Share Posted August 9, 2012 yeah i meant wv not md too... oh well. Link to comment Share on other sites More sharing options...
Kmlwx Posted August 9, 2012 Share Posted August 9, 2012 Some rotation in storms today with at least transient supercell structures from MD into NY.. maybe a good sign or a reach. I'd think good sign? Aren't things supposed to get a bit better tomorrow (barring cloud cover of course). Link to comment Share on other sites More sharing options...
Ellinwood Posted August 9, 2012 Author Share Posted August 9, 2012 I'd like to say it's a good sign, but in my limited experience here I've seen a handful of tornado warnings up in the MD/VA Panhandles for what seems like a very localized area for rotating storms. I don't know if the orography up there is helping create some spin, but rotation definitely seems more prevalent up in that area when other parts of our region are lacking. I would rather see some tor warnings out in OH/IN since that's the real upstream air we'll be playing in tomorrow. Link to comment Share on other sites More sharing options...
Kmlwx Posted August 9, 2012 Share Posted August 9, 2012 I'd like to say it's a good sign, but in my limited experience here I've seen a handful of tornado warnings up in the MD/VA Panhandles for what seems like a very localized area for rotating storms. I don't know if the orography up there is helping create some spin, but rotation definitely seems more prevalent up in that area when other parts of our region are lacking. I would rather see some tor warnings out in OH/IN since that's the real upstream air we'll be playing in tomorrow. I'd definitely think there is some orography at work. Probably similar to the little "tornado alley" we get down near La Plata with the winds on the Potomac. Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.