Cut-off Storm 10/15 - 10/16

Pieces of H5 (500mb level in the atmosphere) energy travel along the jet streams near the tropopause of the  atmosphere. When two, sometimes more than two, of these pieces come together; it develops a low pressure system. That's precisely what's happening with our storm system this week.



This is an image from the EURO model at the H5 level showing us what happens when a storm phases earlier than usual. The result is a bowling ball vortex traveling slowly from west to east across the country. Notice the positive heights on both sides of the storm, an essential reason why the phase occurred quickly between the northern and southern branches. This system eventually gets to our area Wednesday evening.



Wind gusts will be highest over Long Island. With a High located off the coast and the low pressure storm approaching the area, they will be stuck in between both air pressures which as a result will give them wind gusts possibly over 40 mph. 25-35 kph elsewhere.



Rain will be mainly moderate, heavy at times. The image above is from the EURO 7am Thursday morning. There's a good chance we see greater than 1.50-2.00 inches of rain. Most of this will depend on if and where convection develops. I'll examine that portion of the storm tomorrow, but I don't think it will be bad. Timing is Wednesday night into Thursday morning.

More details to come through the week.

Update:

Rain tomorrow will start between 2-4pm and end 9-11am on Thursday. Totals will range between .75-1.25, a slight downgrade from what I thought originally. If your area sees some convection, it's possible you see 1.50+ inches of rain, but generally should see less than that.

Heaviest rain will be during the morning between 6-8am.

Sunny and pleasant conditions expected Friday and Saturday with temps near 70.

Will update the long range later on

Impressive look. You can tell this system is closed off with the spin in the atmosphere.

Upton pretty juiced up for LI and immed coast

sroc4 wrote:Upton pretty juiced up for LI and immed coast

Upped the amounts from last nights QPF posting - they are seeing training and the convection from the Hcane  Gonzalo I guess.

Ugg thats a lot of rain, going to suck getting into work tomorrow. That line training looks like it could dump a lot and I think winds get a bit up there too, nothing crazy but a front like that. If was really windy yesterday. Yeah the further west gonzalo gets IMO the more moisture will get pulled up, still hasnt made turn to N or NE. Which BTW is now a cat 4 with sustained winds at 135 and pressure 949, wow big boy. Bermuda better be ready.

jmanley32 wrote:Ugg thats a lot of rain, going to suck getting into work tomorrow.  That line training looks like it could dump a lot and I think winds get a bit up there too, nothing crazy but a front like that.  If was really windy yesterday.  Yeah the further west gonzalo gets IMO the more moisture will get pulled up, still hasnt made turn to N or NE.  Which BTW is now a cat 4 with sustained winds at 135 and pressure 949, wow big boy.  Bermuda better be ready.

Holy CRAP - could you imagine if this went as progged last week and the trough pulled it up the coast to us - we would be doomed - I see it is suppose to be a cat 2 (upper end) when it gets near Bermuda - those poor people - nowhere to go except fly out to the states.

The GFS bullseye NW NJ with rain amounts greater than 2.00 inches. I'm not sure if this is accurate, but the area that gets the heaviest rainfall will be where the convection sets up. I believe that will be somewhere between NEPA into NW NJ - NE NJ - NYC - CT

HRRR agrees with the GFS through 6am tommorow...still raining for most of area

Radar at same time....

Bands coming off the ocean are pretty heavy also..

Ugg 6am in the thick of it, fun driving coming up. A drop of rain or snow and trip into the Bronx becomes a nightmare, let alone downpours. Its already very windy down here in Harlem. dtone, you see how windy it is? I would say near where frank placed the winds, I expect they may be higher as front gets closer and is passing or any t-storms in convection, or do we net expect to see any t-storms? I mean non-severe, as I do not see that noted on SPC.

mugs no its supposed to be a cat 3 basically right over Bermuda, strongest and probably worse than Fabian.  I really pray for them.  Its going to be a rough ride. Frank you are on your game! NWS moved the precip more towards NYC and CT, less than 2 inches west of NYC. But its kind of dicy I would imagine since convection will be hard to pinpoint.

jmanley32 wrote:mugs no its supposed to be a cat 3 basically right over Bermuda, strongest and probably worse than Fabian.  I really pray for them.  Its going to be a rough ride. Frank you are on your game!  NWS moved the precip more towards NYC and CT, less than 2 inches west of NYC.  But its kind of dicy I would imagine since convection will be hard to pinpoint.

Gonzalo probably stays between 105-110 knots on its way past Bermuda.
Also true about the convection, isolated areas will certainty pick up more QPF than others in the embedded cells when precipital water values increase over night and into tomorrow.

I just noted that although very low SPC has the area under a 2% chance tornados, and 5% chance damaging winds.  I have seen tornados still develop (ALTHOUGH NOT IN MY BACKYARD, BUT CLOSE ONCE) when its at 2% so remember that, I wouldn't be surprised to see some good gusts with any stronger convection on top of the gusty winds from just the passage or the system. What does not make sense to me is the HWO was removed from NYC on eastward, maybe Upton is doing a update and decided to nix the whole old one, I find it hard to imagine its gone completely, just hours ago they were saying spotter activation was likely.

Not much rain yet here i guess it will pick up later on into morning

Just some showers over NYC this morning. Should all come to an end within the hour. How much rain everyone get? I think I got 1.25 ish

I got an inch here...

Not sure hey Ace you got a total if i had to guess maybe an inche

Still pouring by me.

got just over an inch. big difference between cp and lga=jfk. cp 1.68", jfk .76 and lga .72

1.42" at 6:30 AM when I checked the gauge

The rain train has set up over Suffolk County LI. I expect over 2" before its all said and done.