bluewave Posted July 11, 2014 Share Posted July 11, 2014 A closed low is forecast to move to the Great Lakes early next week with an associated cold front slowly approaching the East Coast. This digging closed low will pump the Western Atlantic Ridge to our east and cause the cold front to stall near the region. This will be a tropical airmass with PWATS approaching 2.00". The models typically underestimate rainfall totals when training convection is involved. So the model max totals in the 2-3 inch range may be conservative for locations that experience training of cells as the upper flow becomes parallel to the front under strong upper divergence. The other point to realize is that areas from NYC west have experienced well above normal rainfall for July to date. Link to comment Share on other sites More sharing options...
IsentropicLift Posted July 11, 2014 Share Posted July 11, 2014 Flooding looks to be the main threat early next week. The activity is going to be too widespread and too numerous to support much discrete development. I supposed that we could see a few strong squall lines or MCS which will be very hard to forecast more than a few hours in advance. More than half of the 00z ECMWF ensemble guidance was spitting out > 3" totals with only 9/51 members showing under 2". Link to comment Share on other sites More sharing options...
SnoSki14 Posted July 11, 2014 Share Posted July 11, 2014 I agree about the flood threat though not sure how widespread it'll end up. Link to comment Share on other sites More sharing options...
REDMK6GLI Posted July 11, 2014 Share Posted July 11, 2014 I agree about the flood threat though not sure how widespread it'll end up. Like snowstorms there will be jackpot zones and areas of MUCH less, i know training setups usually favor E.PA and NJ up to LHV. Link to comment Share on other sites More sharing options...
forkyfork Posted July 11, 2014 Share Posted July 11, 2014 probably looking at the highest dewpoints of the summer mon-wed Link to comment Share on other sites More sharing options...
IsentropicLift Posted July 11, 2014 Share Posted July 11, 2014 Caldwell Airport is currently running 97% above normal for the month precip wise and areas just to my north are running well above normal as bluewaves graphic indicates while places closer to the coast have been running near normal or even below normal. Quite a NW to SE gradient currently in the area. Current 6 hour flash flood guidance is under 2" in alot of locations in northern NJ. Link to comment Share on other sites More sharing options...
IsentropicLift Posted July 11, 2014 Share Posted July 11, 2014 Like snowstorms there will be jackpot zones and areas of MUCH less, i know training setups usually favor E.PA and NJ up to LHV. Monday to Tuesday evening favor areas west of NYC before the focus shifts to eastern areas late Tuesday and into Wednesday morning. That's if the front does indeed make it that far east. Link to comment Share on other sites More sharing options...
IsentropicLift Posted July 11, 2014 Share Posted July 11, 2014 The 12z GFS has nothing now on Tuesday after showing a deluge at 06z due to major timing differences. Link to comment Share on other sites More sharing options...
IsentropicLift Posted July 11, 2014 Share Posted July 11, 2014 The 12z ECMWF is roughtly 2.50"-3.00" of rain through late Tuesday night with the heaviest focused near Morristown. Link to comment Share on other sites More sharing options...
SnoSki14 Posted July 11, 2014 Share Posted July 11, 2014 The 12z ECMWF is roughtly 2.50"-3.00" of rain through late Tuesday night with the heaviest focused near Morristown. Since it'll be convective, these amounts may not mean much as totals will vary wildly. Link to comment Share on other sites More sharing options...
IsentropicLift Posted July 11, 2014 Share Posted July 11, 2014 Going to give the dallies on the 12z ECMWF since people will ask. Saturday - Pleasant and Sunny Sunday - Storms fire over NNJ and the LHV between 12z and 18z. Then slowly sag southeastward and expand. Lots of training over northeast and northern NJ and then up into western New England. Then dissipating after sundown before making it to the city. Rainfall between 0.50" and 1.00" with locally higher amounts in training thunderstorms. Monday - Early morning convective debree and and a few showers then another line of showers and storms crosses the region between 12z and 18z from NW to SE. Some areas may stay dry on Monday based on the Euro. Tuesday - Large convective complex forms before 12z with the city getting clipped on the northern fringe. Then nails eastern Long Island hard. Then a very strong area of convection forms on the front, possibly a MCS. That crosses the area from SW to NE between 12z and 00z. The high res Euro is showing a 3" bullseye in 6 hours over Westchester County which it very rarely shows. Then another round comes through between 00z and 06z Wednesday with western Long Island getting pummled. SW CT is the jackpot zone with 5.5"+ and most other areas in the 2-3" range. Link to comment Share on other sites More sharing options...
IsentropicLift Posted July 11, 2014 Share Posted July 11, 2014 Since it'll be convective, these amounts may not mean much as totals will vary wildly. FYI Link to comment Share on other sites More sharing options...
IsentropicLift Posted July 11, 2014 Share Posted July 11, 2014 If storms train over the same areas and Monday ends up wetter like previous runs showed some areas could easily pick up 4"+. Link to comment Share on other sites More sharing options...
REDMK6GLI Posted July 11, 2014 Share Posted July 11, 2014 Hey look! Im in the lower totals in SW suffolk! the shaft cometh again hahaha Link to comment Share on other sites More sharing options...
IsentropicLift Posted July 11, 2014 Share Posted July 11, 2014 Hey look! Im in the lower totals in SW suffolk! the shaft cometh again hahaha Tuesday night looks really good in your neighberhood Link to comment Share on other sites More sharing options...
IsentropicLift Posted July 11, 2014 Share Posted July 11, 2014 WPC pulling the day 3 trigger on the flash flood threat Link to comment Share on other sites More sharing options...
cjr231 Posted July 11, 2014 Share Posted July 11, 2014 Hey look! Im in the lower totals in SW suffolk! the shaft cometh again hahaha I wasn't sure but does Suffolk County suck for thunderstorms? Link to comment Share on other sites More sharing options...
REDMK6GLI Posted July 11, 2014 Share Posted July 11, 2014 I wasn't sure but does Suffolk County suck for thunderstorms? Dont know if you mean that seriously or not but yes i have a better chance at hitting powerball then getting a severe thunderstorm Link to comment Share on other sites More sharing options...
jm1220 Posted July 11, 2014 Share Posted July 11, 2014 Tuesday night looks really good in your neighberhood ecmwf_slp_precip_boston_20.png Poor New York Harbor. Only 0.4" or less for those on the poor trash barges. Link to comment Share on other sites More sharing options...
IsentropicLift Posted July 11, 2014 Share Posted July 11, 2014 Poor New York Harbor. Only 0.4" or less for those on the poor trash barges. Those are only 6 hour totals. Link to comment Share on other sites More sharing options...
IsentropicLift Posted July 11, 2014 Share Posted July 11, 2014 Link to comment Share on other sites More sharing options...
IsentropicLift Posted July 11, 2014 Share Posted July 11, 2014 The 18z 4k NAM has a nice squall line signal for Sunday night. Link to comment Share on other sites More sharing options...
Rjay Posted July 12, 2014 Share Posted July 12, 2014 Tuesday night looks really good in your neighberhood ecmwf_slp_precip_boston_20.png We all know it's very hard to predict rainfall amounts and models don't do a great job with it. It really isn't a great idea talking about numbers when dealing with convection. With that said my area needs the rain. I will gladly take it. The weather has been mostly pretty perfect but I need a change for a couple days. Link to comment Share on other sites More sharing options...
IsentropicLift Posted July 12, 2014 Share Posted July 12, 2014 Euro continues to look great Link to comment Share on other sites More sharing options...
bluewave Posted July 12, 2014 Author Share Posted July 12, 2014 Euro continues to look great It continues with the stronger WAR so the front stalls out right across the region with training convection. Link to comment Share on other sites More sharing options...
forkyfork Posted July 12, 2014 Share Posted July 12, 2014 the gfs came more west than previous runs Link to comment Share on other sites More sharing options...
IsentropicLift Posted July 12, 2014 Share Posted July 12, 2014 18z NAM slowed way down. Link to comment Share on other sites More sharing options...
Isotherm Posted July 12, 2014 Share Posted July 12, 2014 I think we're looking at a very high probability of heavy rains throughout the Northeast corridor. Closed/nearly closed low in the Great Lakes with a retrograding west atlantic ridge should enhance convergence over the region. Furthermore, the strong upper jet streak is positioned such that we're located in a favorable quadrant for upper divergence and low level convergence (right entrance region of streak). As it's currently timed on the ECMWF guidance, I like Tuesday into Wednesday morning for most widespread heavy rains. Sunday-night into Monday could produce scattered hvy convection as well. Link to comment Share on other sites More sharing options...
IsentropicLift Posted July 13, 2014 Share Posted July 13, 2014 WPC has a 3.4" bullseye over NE NJ for 5 day totals. Link to comment Share on other sites More sharing options...
NEG NAO Posted July 13, 2014 Share Posted July 13, 2014 WPC has a 3.4" bullseye over NE NJ for 5 day totals. WPC has increased totals in the metro to over 4 inches qpf http://www.hpc.ncep.noaa.gov/qpf/d13_fill.gif Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.