Stebo Posted May 15, 2014 Share Posted May 15, 2014 Understood. What I don't understand is why just about all the models are weakening the convection as it approaches the region. RH and VVEL are through the roof so to speak and the LLJ looks favorable for moisture transport. The initial low is moving up into Canada and the front is running into the ridge, now if a wave were to form on the front that could enhance things but the prospects of that aren't terribly high plus the convection inherently would weaken as it gets to the coast as it would outrun the better instability with a more stable layer near the coast. Link to comment Share on other sites More sharing options...
IsentropicLift Posted May 15, 2014 Share Posted May 15, 2014 The initial low is moving up into Canada and the front is running into the ridge, now if a wave were to form on the front that could enhance things but the prospects of that aren't terribly high plus the convection inherently would weaken as it gets to the coast as it would outrun the better instability with a more stable layer near the coast. Yeah but this appears to be one of those fire hose setups. We don't normally have these problems in this setup. Link to comment Share on other sites More sharing options...
Stebo Posted May 15, 2014 Share Posted May 15, 2014 Yeah but this appears to be one of those fire hose setups. We don't normally have these problems in this setup. The ridge is strong though and the system is going to use up a lot of the energy and moisture west of NYC also the further the ridge from the east pokes in the less moisture NYC will receive. Link to comment Share on other sites More sharing options...
IsentropicLift Posted May 15, 2014 Share Posted May 15, 2014 The ridge is strong though and the system is going to use up a lot of the energy and moisture west of NYC also the further the ridge from the east pokes in the less moisture NYC will receive. What about northern NJ? Link to comment Share on other sites More sharing options...
IsentropicLift Posted May 15, 2014 Share Posted May 15, 2014 .HYDROLOGY...AFTER COLLABORATING WITH OUR SSH, WE ARE EXPANDING THE FLASH FLOODWATCH FARTHER NORTH THROUGH NJ AND THE POCONOS AS WELL AS MOST OFMONMOUTH COUNTY NJ. WE HAVE A LATER ENDING TIME FOR NORTHERN NJDUE TO THE SLOWING OF THE PCPN SLIGHTLY AS WELL AS A BIT MORE OF ALAG IN RESPONSE TIME FOR SOME OF THE CREEKS AND RIVERS.THE PW VALUES ARE FORECAST TO SURGE INTO THE 1.5 TO 1.75 INCH RANGEFRIDAY AHEAD OF A COLD FRONT GRADUALLY SHIFTING ACROSS OUR AREA AS APOTENT LOW-LEVEL SOUTHERLY JET MOVES THROUGH. THE ENHANCED LIFTWITHIN THE LOW-LEVEL JET, THETA-E ADVECTION, AND THERMAL RIDGESSHOULD RESULT IN A BAND OF HEAVY SHOWERS AND POTENTIALLY SOMEEMBEDDED THUNDER. IT IS PROBABLY IN THIS ZONE WHERE THE HEAVIER RAINOCCURS OVER A SHORTER PERIOD OF TIME.IT STILL LOOKS LIKE THE MAIN AXIS OF MODERATE TO HEAVY RAIN OCCURSBETWEEN 12Z FRIDAY AND 00Z SATURDAY, AND POSSIBLY LASTING AS LATE AS06Z SATURDAY INTO NORTH-CENTRAL PORTIONS OF NEW JERSEY AS THE COLDFRONT SLOWLY MOVES AWAY. THE FLASH FLOOD GUIDANCE IS BETWEEN 1 AND 2INCHES FOR A 3 AND 6 HOUR PERIOD ACROSS MUCH OF SOUTHEASTERNPENNSYLVANIA, NORTHERN DELAWARE, AND EXTENDING NORTHEASTWARD INTOCENTRAL AND NORTHERN NEW JERSEY. AS OF NOW, A GENERAL 1 TO 2 INCHESOF RAIN IS FORECAST WITH THIS SYSTEM ACROSS THE REGION. LOCALLYHIGHER AMOUNTS ARE POSSIBLE, WITH THE BEST CHANCE FOR HIGHER TOTALSACROSS THE WESTERN TO NORTHWEST PART OF THE CWA DUE TO SOMEASSISTANCE BY OROGRAPHIC LIFT /SOUTHEASTERLY INFLOW/. THE MAIN STEMRIVERS ARE NOT EXPECTED TO HAVE ANY ISSUES; HOWEVER, SOME SMALLSTREAM /ESPECIALLY THE FAST RESPONDERS/ AND URBAN RELATED FLOODINGIS POSSIBLE. THIS WOULD BECOME LOCALLY ENHANCED IF BURSTS OF RAINOCCUR IN A SHORTER PERIOD OF TIME. Link to comment Share on other sites More sharing options...
MJO812 Posted May 15, 2014 Share Posted May 15, 2014 I doubt the City is going to see a lot of rain. The models have most of the rain missing to our north and west. Link to comment Share on other sites More sharing options...
Brian5671 Posted May 15, 2014 Share Posted May 15, 2014 I doubt the City is going to see a lot of rain. The models have most of the rain missing to our north and west. Post of the day right here Link to comment Share on other sites More sharing options...
Stebo Posted May 15, 2014 Share Posted May 15, 2014 What about northern NJ? You have a better shot at a little more rain than the city being that you are further west. Link to comment Share on other sites More sharing options...
IsentropicLift Posted May 15, 2014 Share Posted May 15, 2014 You have a better shot at a little more rain than the city being that you are further west. The 12z GFS has the convection refiring once northeast of the area. It's almost like it just skips over us. Looks like the GFS develops a weak area of LP overhead. I think the models are having a really hard time nailing down exactly where the heaviest rains will fall and given the great dynamics aloft I don't think widespread 1-2" with locally higher amounts is a bad call. Especially west of 95. Link to comment Share on other sites More sharing options...
NEG NAO Posted May 15, 2014 Share Posted May 15, 2014 I doubt the City is going to see a lot of rain. The models have most of the rain missing to our north and west. 12Z Nam accumulated 48 hr precip looks weird to say the least http://www.tropicaltidbits.com/analysis/models/namconus/2014051512/namconus_apcpn_us_15.png Link to comment Share on other sites More sharing options...
IsentropicLift Posted May 15, 2014 Share Posted May 15, 2014 12Z Nam accumulated 48 hr precip looks weird to say the least http://www.tropicaltidbits.com/analysis/models/namconus/2014051512/namconus_apcpn_us_15.png The 12z GFS also has a secondary precip maxima NE of NYC Link to comment Share on other sites More sharing options...
NEG NAO Posted May 15, 2014 Share Posted May 15, 2014 The 12z GFS also has a secondary precip maxima NE of NYC But the NAM has one just in eastern half of NJ with the western half kind of sandwiched inbetween that and the much heavier precip to the west - with even lighter pockets in extreme western NJ in spots doubt if that will verify http://www.tropicaltidbits.com/analysis/models/namconus/2014051512/namconus_apcpn_us_15.png Link to comment Share on other sites More sharing options...
IsentropicLift Posted May 15, 2014 Share Posted May 15, 2014 But the NAM has one just in eastern half of NJ with the western half kind of sandwiched inbetween that and the mush heavier precip to the west - doubt if that will verify http://www.tropicaltidbits.com/analysis/models/namconus/2014051512/namconus_apcpn_us_15.png Well on the NAM at hour 33 it shows 0.75" max over eastern PA. At hours 36-39 it diminishes to 0.50" max as the heart of the line crosses NJ. Then at hour 42 at 0.75" max shows up again over NE NJ and continues up into New England. For some odd reason the models show a temporary weakening right as the line crosses the area only to re fire again. Link to comment Share on other sites More sharing options...
Brian5671 Posted May 15, 2014 Share Posted May 15, 2014 The 12z GFS has the convection refiring once northeast of the area. It's almost like it just skips over us. Looks like the GFS develops a weak area of LP overhead. I think the models are having a really hard time nailing down exactly where the heaviest rains will fall and given the great dynamics aloft I don't think widespread 1-2" with locally higher amounts is a bad call. Especially west of 95. There will be surprises with this one no doubt, best chance IMO is somewhere west of NYC to Harrisburg/State College area Link to comment Share on other sites More sharing options...
forkyfork Posted May 15, 2014 Share Posted May 15, 2014 the euro shows about .25" today and another .75" with the line tomorrow Link to comment Share on other sites More sharing options...
Brian5671 Posted May 15, 2014 Share Posted May 15, 2014 nice cell out in western NJ. Eastern NY state has also been getting on and off showers all day. Nothing here yet, 71/66, cloudy with some brightening from time to time. Link to comment Share on other sites More sharing options...
jm1220 Posted May 15, 2014 Share Posted May 15, 2014 There will be surprises with this one no doubt, best chance IMO is somewhere west of NYC to Harrisburg/State College area I-81 corridor will probably have some heavy amounts. That's where it starts to get much hillier to the west, and where the upslope SE flow can enhance totals. Link to comment Share on other sites More sharing options...
IsentropicLift Posted May 15, 2014 Share Posted May 15, 2014 Update from HPC Link to comment Share on other sites More sharing options...
IsentropicLift Posted May 15, 2014 Share Posted May 15, 2014 .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...THE GFS INITIALIZATION LOOKED BETTER AT 500MB THAN YESTERDAY, BUTTHE WRF-NMMB STILL LOOKED BETTER AT 850MB AND 925MB. TODAY WE USEDMORE OF A MODEL BLEND THROUGH THE SHORT TERM. NO CHANGES TO THEFLASH FLOOD WATCH.OUR CWA HAS BECOME WARMER THAN FORECAST AND SOME HOME BREWEDSHOWERS AND EVEN AN ISOLATED THUNDERSTORM OR TWO HAVE DEVELOPED.THIS IS PRECEDING A SOLID LINE OF SHOWERS AND THUNDERSTORMS TO THEWEST OF OUR CWA.THE GENERAL DEEP SOUTHERLY FLOW IS NOT CONDUCIVE TO HAVING THISLINE WHISK INTO OUR CWA AND THE MESOSCALE MODELS ARE DISSIPATINGTHIS CONVECTION BEFORE IT ARRIVES. BUT, THE MODELING IN GENERALHAS BEEN TOO COOL WITH TEMPS TODAY AND STILL ARE. SO THERE WILL BEMORE INSTABILITY THAN THEY PERCEIVE. WE GIVE WEAKENING PARTS OFTHIS CONVECTION A CHANCE TO MAKE IT INTO OUR WESTERN CWA THISEVENING.OTHERWISE, THE PVA LOBE ASSOCIATED WITH THIS FEATURE IS PREDICTEDTO PASS INTO OUR CWA BEFORE MORNING. THERE IS PREDICTED OMEGA ANDMID LEVEL WAA WITH THIS FEATURE, SO WE HAVE POPS THAT ARE MUCHHIGHER THAN THE MODELING QPF FIELDS WOULD INFER, ESPECIALLY WEST.AS FOR FOG, WHILE IT IS OBVIOUSLY HUMID, THERE IS MUCH GREATERWIND THAN LAST NIGHT AND THE SEQUENCE OF EVENTS SUGGEST THECOOLING SHOULD FORM CLOUDS (STRATUS) FIRST AND THERE BE TOO MUCHWIND FOR FOG TO FORM PRIOR. FROM A PUBLIC, TRAVELING PERSPECTIVE,NO FOG RELATED PROBLEMS ANTICIPATED. FOR NOW WE HAVE KEPT MENTIONFOG IN THE AVIATION AND MARINE FORECASTS. PRETTY WARM AND HUMID,SO WE WENT HIGHER THAN STAT GUIDANCE FOR THE DROP OFF OF TEMPSINTO THIS EVENING AND THEN WITH THE HIGHER NAM MOS FOR THE ACTUALMINS. Link to comment Share on other sites More sharing options...
IsentropicLift Posted May 15, 2014 Share Posted May 15, 2014 Sizeable uptick in forecasted totals over the area, especially NW. The 18z NAM just increased totals over 12z as well. Now between 1.25-1.50" for NYC as opposed to Barely 0.75"+ at 12z. Link to comment Share on other sites More sharing options...
IsentropicLift Posted May 15, 2014 Share Posted May 15, 2014 Flash Flood Watches now added by Upton across the board FLOOD WATCHNATIONAL WEATHER SERVICE NEW YORK NY419 PM EDT THU MAY 15 2014...FLASH FLOODING POSSIBLE FRIDAY AND FRIDAY NIGHT FOR NORTHEASTNEW JERSEY...PORTIONS OF SOUTHEAST NEW YORK AND SOUTHERN FAIRFIELDCOUNTY IN CONNECTICUT...CTZ009-NJZ002-004-006-103>108-NYZ067-069>075-176>179-161000-/O.NEW.KOKX.FF.A.0001.140516T1600Z-140517T1000Z//00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/SOUTHERN FAIRFIELD-WESTERN PASSAIC-EASTERN PASSAIC-HUDSON-WESTERN BERGEN-EASTERN BERGEN-WESTERN ESSEX-EASTERN ESSEX-WESTERN UNION-EASTERN UNION-ORANGE-ROCKLAND-NORTHERN WESTCHESTER-SOUTHERN WESTCHESTER-NEW YORK (MANHATTAN)-BRONX-RICHMOND (STATEN ISLAND)-KINGS (BROOKLYN)-NORTHERN QUEENS-NORTHERN NASSAU-SOUTHERN QUEENS-SOUTHERN NASSAU-419 PM EDT THU MAY 15 2014...FLASH FLOOD WATCH IN EFFECT FROM FRIDAY AFTERNOON THROUGH LATEFRIDAY NIGHT...THE NATIONAL WEATHER SERVICE IN NEW YORK HAS ISSUED A* FLASH FLOOD WATCH FOR NORTHEAST NEW JERSEY...PORTIONS OF SOUTHEAST NEW YORK AND SOUTHERN FAIRFIELD COUNTY IN CONNECTICUT.* FROM FRIDAY AFTERNOON THROUGH LATE FRIDAY NIGHT.* A SLOW MOVING COLD FRONT WILL MOVE TOWARDS THE AREA ON FRIDAY. RAIN WILL INCREASE IN COVERAGE DURING THE AFTERNOON AND BECOME HEAVY AT TIMES AT NIGHT WITH THE POTENTIAL FOR TRAINING OF EMBEDDED THUNDERSTORMS. TOTAL RAINFALL IS EXPECTED TO RANGE BETWEEN 1 AND 2 INCHES WITH LOCALIZED AMOUNTS UP TO 3 INCHES IN THE HEAVIER SHOWERS. ADDITIONALLY...THE HEAVIEST RAIN IS EXPECTED TO COINCIDE WITH HIGH TIDE ON THE ATLANTIC AND WESTERN LONG ISLAND SOUND FRIDAY NIGHT WHICH COULD EXACERBATE FLOODING ALONG THE SOUTH SHORE OF LONG ISLAND AND SOUTHERN FAIRFIELD COUNTY IN CONNECTICUT.PRECAUTIONARY/PREPAREDNESS ACTIONS...A FLASH FLOOD WATCH MEANS THAT CONDITIONS MAY DEVELOP THAT LEADTO FLASH FLOODING. FLASH FLOODING IS A VERY DANGEROUS SITUATION.YOU SHOULD MONITOR LATER FORECASTS AND BE PREPARED TO TAKE ACTIONSHOULD FLASH FLOOD WARNINGS BE ISSUED. Link to comment Share on other sites More sharing options...
REDMK6GLI Posted May 16, 2014 Share Posted May 16, 2014 Heaviest rains are now parked over the NJ/ PA border and are pretty much stationary. Should be getting some widespread FFW going up for those parts shortly. Models pinning us down as getting substantially less than that area did an awesome job. The stable air and WAR really did its work in keeping us out of the heaviest precipitation totals Link to comment Share on other sites More sharing options...
Brian5671 Posted May 16, 2014 Share Posted May 16, 2014 Heaviest rains are now parked over the NJ/ PA border and are pretty much stationary. Should be getting some widespread FFW going up for those parts shortly. Models pinning us down as getting substantially less than that area did an awesome job. The stable air and WAR really did its work in keeping us out of the heaviest precipitation totals we'll probably get the tail end of the line towards dinner time. agree, though, no big deal for most of us in this forum Link to comment Share on other sites More sharing options...
IsentropicLift Posted May 16, 2014 Share Posted May 16, 2014 Update from Mt. Holly .NEAR TERM /UNTIL 6 PM THIS EVENING/...ESTF UPDATE TO ADJUST TIMING OF HEAVIEST RAIN BASED ON LATEST HRRRWHICH HAS A DECENT HANDLE. ALL OF THE MESOSCALE MODELS AREPROGRESSING THE PCPN EASTWARD, BUT THEN GOES INTO A STALL AS WEWAIT FOR THE NORTHERN NC WAVE TO MOVE NORTH INTO NJ. NOT MUCHPRESENT LIGHTNING (MOSTLY INSIDE CLOUD) OCCURRING WITH THIS BANDOF PRECIPITATION, TIED TO MORE UNSTABLE SHOWALTERS AND NEG SFCBASED MSAS LI(S) TO OUR SOUTH. THERE IS A SLIGHT UPTICK ININSTABILITY FORECAST FOR TODAY, SO WE WILL KEEP IN THE MENTION OFTHUNDER, ALTHOUGH BETTER CHANCE EAST THAN WEST. WE INCREASED WINDGUSTS FOR THIS MORNING. TEMPS AND DEW POINTS ARE CLOSE AND NO BIGCHANGES THERE.AN AREA OF LOW PRES IN SERN CANADA WILL SLOWLY MOVE NEWD TODAY ANDITS ASSOCD CDFNT WILL GRADUALLY MOVE EWD AS WELL DURG THE DAY.LATEST RADAR IMAGERY DURG THE OVERNIGHT HOURS SHOWED A LARGE SWATHOF PRECIP JUST TO THE W OF THE AREA BUT MOVG GENLY IN A S TO NDIRECTION. THIS PRECIP WILL SHIFT EWD WITH TIME, BUT IS DOING SOMUCH SLOWER THAN ORIGINALLY FCST, SO HAVE LOWERED POPS IN THE REALNEAR TERM TO ACCOUNT FOR THIS.A WAVE OF LOW PRES WILL MOVE NWD ALG THE FRONT DUR THE MRNG/AFTNHOURS AND WILL BE TO THE N OF THE AREA BY EVE. ALL OF THIS POINTSTO A RATHER RAINY TIME FROM THE MORNING INTO THE AFTN WITH RAINTAPERING OFF BY EVE. A GENL 1 TO 2 INCHES OF RAIN IS EXPECTED, BUTA FAIRLY MISERABLE DAY IS IN STORE!HAVE GONE CLOSE TO GUID TEMPS, WHICH SEEMED REASONABLE GIVEN THECLOUDS AND PRECIP. Link to comment Share on other sites More sharing options...
Stormlover74 Posted May 16, 2014 Share Posted May 16, 2014 we'll probably get the tail end of the line towards dinner time. agree, though, no big deal for most of us in this forum It'll get most places to near normal for the month to date. That's about it. Link to comment Share on other sites More sharing options...
IsentropicLift Posted May 16, 2014 Share Posted May 16, 2014 It'll get most places to near normal for the month to date. That's about it. Way to rain on my parade Link to comment Share on other sites More sharing options...
Stormlover74 Posted May 16, 2014 Share Posted May 16, 2014 Way to rain on my parade You mean way to sun on your parade? Link to comment Share on other sites More sharing options...
IsentropicLift Posted May 16, 2014 Share Posted May 16, 2014 You mean way to sun on your parade? No, who says that? Link to comment Share on other sites More sharing options...
Stormlover74 Posted May 16, 2014 Share Posted May 16, 2014 No, who says that? Well since you love rain raining on your parade would be a good thing. Link to comment Share on other sites More sharing options...
IsentropicLift Posted May 16, 2014 Share Posted May 16, 2014 Well since you love rain raining on your parade would be a good thing. How about the latest NAM? Basically takes all of the rain and moves it due north without any eastward progress. Then a break before the NC wave arrives and blasts the city and points east. Basically skips right over NNJ. It doesn't match up well with current radar though. I think their could definitely be some surprises here. Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.