bluewave Posted September 17, 2012 Share Posted September 17, 2012 This is a really anomalous LLJ being forecast during a warm season convective event in our area. Both the GFS and NAM are showing a 5 SD LLJ above climo for our area. Link to comment Share on other sites More sharing options...
nycsnow Posted September 17, 2012 Share Posted September 17, 2012 This is a really anomalous LLJ being forecast during a warm season convective event in our area. Both the GFS and NAM are showing a 5 SD LLJ above climo for our area. What would it be it it mixes down? Link to comment Share on other sites More sharing options...
NorEaster27 Posted September 17, 2012 Share Posted September 17, 2012 What would it be it it mixes down? 50mph gusts at the coast, NAM shows the strogest LLJ riding the NJ coast into western LI. JFK may gust to 50 mph in that setup....however I am still warry of that as these setups often underperform. Link to comment Share on other sites More sharing options...
bluewave Posted September 17, 2012 Share Posted September 17, 2012 What would it be it it mixes down? If the line weakens when it approaches our area tomorrow evening, places along the South Shore like JFK would still be able to gust to 50-55 mph just on the strong pre-frontal winds. The big question will be how well the line holds together as it approaches our region tomorrow night. If the line comes through strong,then spots could see gusts of 60 mph or greater. Link to comment Share on other sites More sharing options...
blizzardof09 Posted September 17, 2012 Share Posted September 17, 2012 If the line weakens when it approaches our area tomorrow evening, places along the South Shore like JFK would still be able to gust to 50-55 mph just on the strong pre-frontal winds. The big question will be how well the line holds together as it approaches our region tomorrow night. If the line comes through strong,then spots could see gusts of 60 mph or greater. have lines of storms this year keep there intensity as they approach the coast and then some has been close to impossible. there has always been some svr. parameter that substantially weakens it, cant help but to be very cautious with some of these models as of now Link to comment Share on other sites More sharing options...
nycsnow Posted September 17, 2012 Share Posted September 17, 2012 Thanks for the answers guys Link to comment Share on other sites More sharing options...
bluewave Posted September 17, 2012 Share Posted September 17, 2012 have lines of storms this year keep there intensity as they approach the coast and then some has been close to impossible. there has always been some svr. parameter that substantially weakens it, cant help but to be very cautious with some of these models as of now We'll have to watch for storm rotation and possible isolated tornadoes during the day in the WAA convection that will be moving north well ahead of any line back to the west. Spots where the line stays strong could also see an embedded tornado threat. But as always, we'll have to watch the actual radar trends to know where and how much severe potential is realized around the Northeast tomorrow. Link to comment Share on other sites More sharing options...
SBUWX23 Posted September 17, 2012 Share Posted September 17, 2012 Why is there a focus on just a convective line? With winds just above the deck as strong as modeled, and no inversion, some of those winds could mix down outside of convection as well. Link to comment Share on other sites More sharing options...
NorEaster27 Posted September 17, 2012 Share Posted September 17, 2012 JFK hit 41 mph with a due south wind Saturday afternoon before the main line, however at that time dews were in the mid 70s and it was sunny. JFK *should* beat that speed with the modeled LLJ. Water temps are still in the low to mid 70s, a tad lower but not much compared to last saturday. Link to comment Share on other sites More sharing options...
SBUWX23 Posted September 17, 2012 Share Posted September 17, 2012 This set up does not even compare to the last one with regards to the wind field. JFK hit 41 mph with a due south wind Saturday afternoon before the main line, however at that time dews were in the mid 70s and it was sunny. JFK *should* beat that speed with the modeled LLJ. Link to comment Share on other sites More sharing options...
Quincy Posted September 17, 2012 Share Posted September 17, 2012 This is a really anomalous LLJ being forecast during a warm season convective event in our area. Both the GFS and NAM are showing a 5 SD LLJ above climo for our area. Fig. B: Is the key for this standard deviations? Why is there a focus on just a convective line? With winds just above the deck as strong as modeled, and no inversion, some of those winds could mix down outside of convection as well. Exactly. This situation has some similarities to last Saturday's event. Remember, the tornadoes with that storm happened in the morning, WELL ahead of the cold front/convective line. Link to comment Share on other sites More sharing options...
rcad1 Posted September 17, 2012 Share Posted September 17, 2012 Looks like nws agrees that this could be a wind event even without convection with wind adv and poss high wind warns issued for the area if models are correct that is.... Link to comment Share on other sites More sharing options...
Quincy Posted September 17, 2012 Share Posted September 17, 2012 Looks like nws agrees that this could be a wind event even without convection with wind adv and poss high wind warns issued for the area if models are correct that is.... Gale Watches already up for all surrounding waters. Link to comment Share on other sites More sharing options...
rcad1 Posted September 17, 2012 Share Posted September 17, 2012 Quincy what does that usally mean for wind on land areas for example long island Link to comment Share on other sites More sharing options...
Weathergun Posted September 17, 2012 Share Posted September 17, 2012 These are 950mb winds (kts) on the 12z NAM at 8pm and 11pm tomorrow night. This is a solid wind advisory event, near the coast: Link to comment Share on other sites More sharing options...
NorEaster27 Posted September 17, 2012 Share Posted September 17, 2012 How does hour 36 look? Link to comment Share on other sites More sharing options...
NorEaster27 Posted September 17, 2012 Share Posted September 17, 2012 http://68.226.77.253/text/NAM80km/NAM_Kjfk.txt 12z NAM shows 50k at 950mb (KJFK) 8pm tomorrow night. Link to comment Share on other sites More sharing options...
Quincy Posted September 17, 2012 Share Posted September 17, 2012 Sustained winds well over 30 MPH for parts of the shoreline and Long Island. Below are more 10m wind images from the 12z WRF: Link to comment Share on other sites More sharing options...
Weathergun Posted September 17, 2012 Share Posted September 17, 2012 How does hour 36 look? I edited my NAM post. Link to comment Share on other sites More sharing options...
earthlight Posted September 17, 2012 Share Posted September 17, 2012 900 hPa winds are pretty impressive on the 12km NAM Link to comment Share on other sites More sharing options...
NorEaster27 Posted September 17, 2012 Share Posted September 17, 2012 I edited my NAM post. very impressive Link to comment Share on other sites More sharing options...
nycsnow Posted September 17, 2012 Share Posted September 17, 2012 very impressive Wonder what Upton does today maybe flood watch high wind watch? Link to comment Share on other sites More sharing options...
Weathergun Posted September 17, 2012 Share Posted September 17, 2012 very impressive This is the 12z GFS 950mb winds at 8pm tomorrow. Looks a little faster and even stronger with the LLJ than the NAM. Link to comment Share on other sites More sharing options...
Brian5671 Posted September 17, 2012 Share Posted September 17, 2012 Upton will likely hoist wind advisories at 4pm for LI, S CT if those maps as to be believed. Link to comment Share on other sites More sharing options...
Quincy Posted September 17, 2012 Share Posted September 17, 2012 Another view: Screaming 850mb jet Link to comment Share on other sites More sharing options...
NorEaster27 Posted September 17, 2012 Share Posted September 17, 2012 This is the 12z GFS 950mb winds at 8pm tomorrow. Looks a little faster and even stronger with the LLJ than the NAM. I dont remember seeing a LLJ that strong outside of the winter before....high wind watch along the coast? Link to comment Share on other sites More sharing options...
Kaner587 Posted September 17, 2012 Share Posted September 17, 2012 Wow 900mb winds on the 12z NAM of 68-72knots. Impressive to say the least. This is definitely a highly anomalous situation I am definitely intrigued to see how this event unfolds. Especially if we can get a little severe with it earlier in the day. Link to comment Share on other sites More sharing options...
earthlight Posted September 17, 2012 Share Posted September 17, 2012 30% hatch now from SPC IN WAKE OF NWD ADVANCING WARM FRONT...RICH GULF MOISTURE WITH UPPER 60S TO NEAR 70F DEWPOINTS WILL ADVECT THROUGH WARM SECTOR ALONG STRENGTHENING 50+ KT LLJ. WIDESPREAD CLOUDS WITH AREAS OF RAIN AND THUNDERSTORMS WILL LIKELY BE ONGOING ALONG WARM CONVEYOR BELT AND WITHIN PLUME OF DEEPER SUBTROPICAL MOISTURE...ESPECIALLY IN WRN PORTION OF WARM SECTOR. SOME OF THIS ACTIVITY COULD POSE A THREAT OF MAINLY ISOLATED DAMAGING WIND FROM THE WRN CAROLINAS INTO WRN VA. CLOUDS AND AREAS OF RAIN WILL CONTRIBUTE TO WEAK MID LEVEL LAPSE RATES AND INSTABILITY...POSSIBLY SERVING AS A LIMITING FACTOR. THE MOST FAVORABLE SHEAR/INSTABILITY PARAMETER SPACE FOR SEVERE STORMS IS EXPECTED EVOLVE OVER THE MID ATLANTIC REGION ALONG STRENGTHENING LLJ AND WHERE A FEW CLOUD BREAKS WILL PROMOTE AT LEAST MODEST BOUNDARY LAYER DESTABILIZATION WITH 500-1000 J/KG MLCAPE POSSIBLE. STORMS ARE EXPECTED TO INTENSIFY AS THEY DEVELOP EWD THROUGH THE DESTABILIZING WARM SECTOR. MIXED CONVECTIVE MODES ARE LIKELY INCLUDING LINES WITH EMBEDDED SUPERCELLS/BOWING SEGMENTS. A FEW DISCRETE SUPERCELLS MAY ALSO OCCUR IF SUFFICIENT BOUNDARY LAYER WARMING OCCURS. DAMAGING WIND AND A FEW TORNADOES WILL BE THE PRIMARY THREATS. THIS REGION WILL CONTINUE TO BE MONITORED FOR A POSSIBLE MODERATE RISK IF IT BEGINS TO APPEAR THAT MORE INSTABILITY WILL DEVELOP THAN CURRENTLY ANTICIPATED. Link to comment Share on other sites More sharing options...
NorEaster27 Posted September 17, 2012 Share Posted September 17, 2012 can someoen post a NAM sounding for KJFK at 36 hours? Any inversion? Link to comment Share on other sites More sharing options...
Snow_Miser Posted September 17, 2012 Share Posted September 17, 2012 Mount Holly just issued Wind Advisories for pretty much the entire CWA. ...STRONG GUSTY WINDS ARE EXPECTED FROM TUESDAY AFTERNOON INTO TUESDAY NIGHT... .A COLD FRONT FROM THE WEST IS FORECAST TO PASS THROUGH EASTERN PENNSYLVANIA, NORTHEASTERN MARYLAND, DELAWARE AND NEW JERSEY ON TUESDAY NIGHT. A STRONG SOUTH TO SOUTHWEST WIND IS ANTICIPATED IN ADVANCE OF THE FRONT`S ARRIVAL. DEZ001>004-MDZ008-012-015-019-020-NJZ001-007>010-012>027-PAZ054- 055-060>062-067>071-181000- /O.NEW.KPHI.WI.Y.0009.120918T1600Z-120919T0400Z/ NEW CASTLE-KENT-INLAND SUSSEX-DELAWARE BEACHES-CECIL-KENT MD- QUEEN ANNES-TALBOT-CAROLINE-SUSSEX-WARREN-MORRIS-HUNTERDON- SOMERSET-MIDDLESEX-WESTERN MONMOUTH-EASTERN MONMOUTH-MERCER-SALEM- GLOUCESTER-CAMDEN-NORTHWESTERN BURLINGTON-OCEAN-CUMBERLAND- ATLANTIC-CAPE MAY-ATLANTIC COASTAL CAPE MAY-COASTAL ATLANTIC- COASTAL OCEAN-SOUTHEASTERN BURLINGTON-CARBON-MONROE-BERKS-LEHIGH- NORTHAMPTON-CHESTER-MONTGOMERY-BUCKS-DELAWARE-PHILADELPHIA- INCLUDING THE CITIES OF...WILMINGTON...DOVER...GEORGETOWN... REHOBOTH BEACH...ELKTON...CHESTERTOWN...CENTREVILLE...EASTON... DENTON...NEWTON...WASHINGTON...MORRISTOWN...FLEMINGTON... SOMERVILLE...NEW BRUNSWICK...FREEHOLD...SANDY HOOK...TRENTON... PENNSVILLE...GLASSBORO...CAMDEN...CHERRY HILL...MOORESTOWN... MOUNT HOLLY...JACKSON...MILLVILLE...HAMMONTON... CAPE MAY COURT HOUSE...OCEAN CITY...ATLANTIC CITY... LONG BEACH ISLAND...WHARTON STATE FOREST...JIM THORPE... STROUDSBURG...READING...ALLENTOWN...BETHLEHEM...WEST CHESTER... NORRISTOWN...DOYLESTOWN...MEDIA...PHILADELPHIA 254 PM EDT MON SEP 17 2012 ...WIND ADVISORY IN EFFECT FROM NOON TUESDAY TO MIDNIGHT EDT TUESDAY NIGHT... THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY HAS ISSUED A WIND ADVISORY. IT IS IN EFFECT FROM NOON TUESDAY UNTIL MIDNIGHT TUESDAY NIGHT. * WINDS...A SOUTH WIND AT 20 TO 25 MPH ON TUESDAY AFTERNOON BECOMING SOUTHWEST ON TUESDAY EVENING. WIND GUSTS AROUND 45 MPH ARE EXPECTED. GUSTS AROUND 50 MPH ARE POSSIBLE NEAR THE COAST. * TIMING...WIND SPEEDS ARE FORECAST TO INCREASE ON TUESDAY AFTERNOON WITH THE STRONG WIND EXPECTED TO CONTINUE ON TUESDAY EVENING. WIND SPEEDS ARE ANTICIPATED TO DIMINISH LATE ON TUESDAY NIGHT, FOLLOWING THE PASSAGE OF A COLD FRONT. * IMPACTS...THE STRONG WIND MAY BRING DOWN TREE LIMBS AND UTILITY LINES. OUTDOOR ITEMS SUCH AS PATIO FURNITURE AND GARBAGE CANS WILL BE BLOWN ABOUT. THE WIND MAY ALSO MAKE DRIVING DIFFICULT, ESPECIALLY ON BRIDGES AND ON ELEVATED ROADWAYS. Link to comment Share on other sites More sharing options...
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