IsentropicLift Posted April 14, 2014 Share Posted April 14, 2014 TONIGHT THROUGH TUESDAY NIGHT...MODELS HAVE BEEN CONSISTENTOVER LAST FEW DAYS SHOWING A STRENGTHENING COLD FRONT APPROACHINGAND MOVING ACROSS THE REGION TUESDAY EVENING. LAYER PW HAS ALSO BEENCONSISTENT...STILL CONVEYING 1.3 TO 1.5 INCHES...ABOUT 2 STANDARDDEVIATIONS ABOVE NORMAL FOR THIS TIME OF YEAR...ADDING TO THEPOTENTIAL FOR HEAVY RAIN. THIS GOES ALONG WITH THE INCREASINGMERIDIONAL FLOW FROM THE APPROACHING TROUGH AND UPPER LEVEL JETORIENTED SOUTHWEST TO NORTHEAST...TAPPING INTO GULF MOISTURE. THISINCREASING MOISTURE ADVECTION IS REFLECTED AS WELL WITH THE LOWLEVELS...WHICH WILL HAVE AN INCREASE IN STRATUS AND/OR FOG TONIGHTINTO TUESDAY MORNING. THE FOG COULD POTENTIALLY BE DENSE ASDEWPOINTS INCREASE AND SEA SURFACE TEMPERATURES WILL STILL BERELATIVELY COOL.THE STRENGTH OF THE PARENT LOW IS NEARLY THE SAME COMPARED TOPREVIOUS RUNS WITH NEARLY THE SAME MAGNITUDE OF LOW LEVEL JET.NAM SHOWS 70-80 KT AROUND 900MB TUESDAY AFTERNOON AND EVENINGWHILE GFS SHOWS 60-70 KT. INVERSION WILL LIMIT GUSTS BUT MODERATETO HEAVY RAIN MAY HAVE ENOUGH DOWNWARD MOMENTUM TO OVERCOME THEINVERSION AND BRING A FRACTION OF THIS LOW LEVEL JET TO THESURFACE. THERE IS A POTENTIAL HERE FOR HIGHEST GUSTS IN THE 40-55MPH RANGE WITH HEAVY RAIN WHICH WILL BE MORE PERIODIC IN FREQUENCY.FOR EXAMPLE...THIS COULD BE OBSERVED WITHIN HEAVIER CELLSASSOCIATED WITH A SQUALL LINE JUST AHEAD OF THE COLD FRONT AS ITMOVES THROUGH. MESOSCALE MODELS ARE POINTING TO THIS SORT OFSTRUCTURE TO RAINFALL BETWEEN MID AFTERNOON TUESDAY AND EARLYTUESDAY EVENING.PRECIP BEHIND THE COLD FRONT CONTINUES A TREND TO END AS ASLEET/SNOW MIX AS COLDER AIR MOVES IN...MAINLY IN THE BOUNDARYLAYER. PART OF THE ATMOSPHERIC COLUMN BETWEEN 700 AND 850 MB MAYSTILL BE A LITTLE ABOVE FREEZING...HENCE THE POTENTIAL FOR SLEET.GUSTS WILL BE MORE FREQUENT TOO WITH THE COLD AIR ADVECTIONINCREASING THE MIXING LENGTH TUESDAY NIGHT WITH THE NORTHWESTFLOW...ALTHOUGH THE GUSTS WILL PROBABLY BE MORE BETWEEN 35-45 MPHWITH THE DECREASING BOUNDARY LAYER WINDS AS THE LOW LEVEL JET WILLHAVE MOVED WELL SOUTHEAST OF THE REGION WITH THE FRONT.IN SUMMARY...THERE WILL STILL BE A WIDESPREAD RAIN EVENT WITH THEPOTENTIAL FOR HEAVY RAIN AT TIMES ALONG WITH A CHANCE OF GUSTY WINDSAT TIMES WITH THE HEAVIER RAIN AND MORE FREQUENT WITH THE COLD AIRADVECTION LATER TUESDAY NIGHT. LATE TUESDAY NIGHT...ENOUGH COLDAIR COULD MOVE IN FOR LEFTOVER SNOW SHOWERS AND/OR SLEET WITHLIGHT ACCUMULATIONS POSSIBLE NORTH AND WEST OF NEW YORK CITY. LOWTEMPERATURES WILL BE NEAR OR BELOW FREEZING LATE TUESDAY NIGHTINTO VERY EARLY WEDNESDAY MORNING. Link to comment Share on other sites More sharing options...
MJO812 Posted April 14, 2014 Share Posted April 14, 2014 Interesting day tomorrow into Wednesday Link to comment Share on other sites More sharing options...
IsentropicLift Posted April 14, 2014 Author Share Posted April 14, 2014 41/50 00z Euro ensemble members had at least an inch of rain over NNJ. Link to comment Share on other sites More sharing options...
IsentropicLift Posted April 14, 2014 Author Share Posted April 14, 2014 Link to comment Share on other sites More sharing options...
IsentropicLift Posted April 14, 2014 Author Share Posted April 14, 2014 HPC has placed our area in a slight risk again for excessive rainfall tomorrow. Flash Flood guidance remains low over northern NJ Link to comment Share on other sites More sharing options...
Allsnow Posted April 14, 2014 Share Posted April 14, 2014 That does not look like our area at all for slight risk of flooding Link to comment Share on other sites More sharing options...
IsentropicLift Posted April 14, 2014 Author Share Posted April 14, 2014 That does not look like our area at all for slight risk of floodingSo NW NJ isn't part of this area? Regardless look at the green line that runs east. Link to comment Share on other sites More sharing options...
SnoSki14 Posted April 14, 2014 Share Posted April 14, 2014 Am I crazy or does the gfs and nam indicate some snow before the precip ends west of the city even into central nj? The Nam especially looks like it brings in the cold faster than the gfs, of course it is the Nam. That would be pretty amazing to see this late in the season especially after several days of 70s and 80s. Link to comment Share on other sites More sharing options...
IsentropicLift Posted April 15, 2014 Author Share Posted April 15, 2014 Am I crazy or does the gfs and nam indicate some snow before the precip ends west of the city even into central nj? The Nam especially looks like it brings in the cold faster than the gfs, of course it is the Nam. That would be pretty amazing to see this late in the season especially after several days of 70s and 80s. Read the bolded post in April discussion Link to comment Share on other sites More sharing options...
JC-CT Posted April 15, 2014 Share Posted April 15, 2014 Am I crazy or does the gfs and nam indicate some snow before the precip ends west of the city even into central nj? The Nam especially looks like it brings in the cold faster than the gfs, of course it is the Nam. That would be pretty amazing to see this late in the season especially after several days of 70s and 80s. You should check out the Euro then. Link to comment Share on other sites More sharing options...
SnoSki14 Posted April 15, 2014 Share Posted April 15, 2014 I don't get the euro model, what did it show? Link to comment Share on other sites More sharing options...
JC-CT Posted April 15, 2014 Share Posted April 15, 2014 I don't get the euro model, what did it show? Wunderground. And no, I didn't stay/wake up for it, I just randomly woke up lol. Link to comment Share on other sites More sharing options...
Mikehobbyst Posted April 15, 2014 Share Posted April 15, 2014 The moon has been totally eclipsed by low clouds on LI for hours already... Another busted astronomical event this year. Link to comment Share on other sites More sharing options...
green tube Posted April 15, 2014 Share Posted April 15, 2014 The moon has been totally eclipsed by low clouds on LI for hours already... Another busted astronomical event this year. http://new.livestream.com/GriffithObservatoryTV/LunarEclipse Link to comment Share on other sites More sharing options...
Mikehobbyst Posted April 15, 2014 Share Posted April 15, 2014 http://new.livestream.com/GriffithObservatoryTV/LunarEclipse Thanks, I got to see the eclipse and hear some commentary from LA. The heavenly Cookie Monster had a bountiful feast tonight. "Nom, nom nom..." It's ending now at 1:25 PDT there... Link to comment Share on other sites More sharing options...
IsentropicLift Posted April 15, 2014 Author Share Posted April 15, 2014 Hey AllSnow, are we still not in the slight risk zone? Link to comment Share on other sites More sharing options...
IsentropicLift Posted April 15, 2014 Author Share Posted April 15, 2014 Some MUCAPE starting to build over southern and eastern sections. Link to comment Share on other sites More sharing options...
IsentropicLift Posted April 15, 2014 Author Share Posted April 15, 2014 Really nice moisture feed coming right into our region. Link to comment Share on other sites More sharing options...
Stormlover74 Posted April 15, 2014 Share Posted April 15, 2014 Gfs/Nam both showing under an inch now and falling over a 12 hour period. Flooding should be fairly localized Link to comment Share on other sites More sharing options...
IsentropicLift Posted April 15, 2014 Author Share Posted April 15, 2014 Gfs/Nam both showing under an inch now and falling over a 12 hour period. Flooding should be fairly localized The 4k NAM shows a lot of training of storms later this afternoon and tonight and the radar to our southwest remains impressive. I think all areas easily pick up 1"+ today. Link to comment Share on other sites More sharing options...
IsentropicLift Posted April 15, 2014 Author Share Posted April 15, 2014 Large swath of >0.25" per hour rates with pockets ~1.00" per hour over SE PA and DC area estimated by radar. It's going to pour this evening. Link to comment Share on other sites More sharing options...
IsentropicLift Posted April 15, 2014 Author Share Posted April 15, 2014 Based on current radar trends the steady rain is now entering Philadelphia and should be over taking most of northern NJ in the next hour or so, especially the western 2/3rds. Then into the city between noon and 1:00PM. Link to comment Share on other sites More sharing options...
IsentropicLift Posted April 15, 2014 Author Share Posted April 15, 2014 I wonder if the models are struggling today with the positioning of cold front and the LLJ. For example it's currently almost 15z. The 12z NAM's depiction says that by 18z virtually no rain has fallen in the Delmarva in the past six hours yet it's currently pouring in that region. Then it doesn't have the real heavy precip into southeast Virginia until after 18z yet that area is currently getting blasted by heavy convection. Link to comment Share on other sites More sharing options...
Brian5671 Posted April 15, 2014 Share Posted April 15, 2014 Western CT has been getting hit by a persistent band ahead of the main band, already .40 here with the main show to come. Link to comment Share on other sites More sharing options...
IsentropicLift Posted April 15, 2014 Author Share Posted April 15, 2014 Western CT has been getting hit by a persistent band ahead of the main band, already .40 here with the main show to come. Yeah I don't think the models are going to bust badly on this one but areas should easily pick up over an inch except in isolated areas that manage to miss the heaviest bands. Link to comment Share on other sites More sharing options...
IsentropicLift Posted April 15, 2014 Author Share Posted April 15, 2014 Actually a pocket of some SBCAPE developing over eastern PA Link to comment Share on other sites More sharing options...
IsentropicLift Posted April 15, 2014 Author Share Posted April 15, 2014 First downpour of the day here in Ramsey has commenced. Link to comment Share on other sites More sharing options...
Stormlover74 Posted April 15, 2014 Share Posted April 15, 2014 Pretty decent line moving into the area from PA Link to comment Share on other sites More sharing options...
Brian5671 Posted April 15, 2014 Share Posted April 15, 2014 Strong winds here the last hour or so....every so often a squall moves through, almost tropical like. Link to comment Share on other sites More sharing options...
IsentropicLift Posted April 15, 2014 Author Share Posted April 15, 2014 That's a bow echo now crossing into Warren and Morris Counties. Wouldn't be shocked to see a warning hoisted. Link to comment Share on other sites More sharing options...
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