TriPol

I "should?" I don't work for the NWS. I'm just someone who has obsessively watched every model run for the past few days. Trying to distract myself from work.

It's going to be a Nor'Easter. We'll get a few inches of rain we don't need right now. Trees will fall. Roads will flood. We'll live! Then, next week, we'll be in the 70s. I'm semi-looking forward to that before it starts getting to sweater weather.

I don't see Don downplaying it at all. He's said uncertainty exists. That was 12 hours ago. I think if the 12z suites all come in where they've been overnight, the uncertainty will disappear. NOAA hugging the GFS is new to me, but we'll see what they do. I think by 1 PM today, they'll hoist Gale and HWW for Long Island, not just the coastal waters. I think they'll also start flood watches beginning tomorrow at 8 pm for the area as well.

There isn't a model that doesn't show a major east coast storm. GFS caved.

This has got to change: .DISCUSSION... .KEY MESSAGE 1... Models in general agreement with a closed 500mb low over or near the forecast area Friday through Sunday. Given its location, anticipating the surface low to track near or not too far east of the 40N/70W benchmark during Saturday before meandering or retrograding toward the coast late in the weekend, then slowly departing during Monday as it weakens. Confidence in this track is still not high due to the closed/cutoff low aloft. Rain chances begin Friday morning, and mainly east of the city, rain is likely Friday afternoon through Saturday afternoon. For the the city and points west, rain chances are mostly below 50% up until Saturday afternoon and night. Still thinking that rainfall flooding impacts are little to none - just low chance for flooding across far eastern zones, and probably limited to minor nuisance and poor drainage flooding. Long Island, especially eastern Long Island, can handle a fair amount of rain, especially the long duration nature of the event. However, if the NAM verifies, a period of heavy rain is possible the first part of Saturday night, with over 2 inches of rainfall for the south fork of Long Island in a 6 hour period. If models trend west with the storm track, then western zones could have a chance of minor flooding. The Weather Prediction Center has placed southeast CT and central and easter Long Island in a marginal to slight risk of excessive rainfall from Friday through Monday night. As for winds, continue anticipating gusts to remain below advisory thresholds, but it could come close across eastern LI and SE CT late day Friday through Saturday morning. However, there may be isolated incidents of downed trees and power lines due to the heavy rain loosening the soil and weighing down leaves in combination with breezy/windy conditions.

If this verifies, NOAA, the NYC government, and the broadcast weathermen are doing a disservice by downplaying this.

The 06Z GFS is broadly similar to the 00Z run, but there are several important differences in timing, intensity and the eventual track of the coastal storm. The first notable change is that the 06Z GFS develops and deepens the cyclone somewhat faster. By Friday morning, the 06Z run has the low near 997 mb, roughly a couple of millibars deeper than the 00Z run at the same valid time. Through Friday night and early Saturday, that difference gradually shrinks. By Saturday morning and afternoon, both runs are clustered near 991 to 993 mb, showing remarkably good agreement on the storm's peak intensity. The larger difference involves what happens after the cyclone reaches its mature stage. The 00Z GFS showed a clearer and more sustained westward retrograde, bringing the low back toward the New York and New Jersey coastline after it stalled offshore. The 06Z GFS still stalls the cyclone southeast of Long Island, but the westward motion is less pronounced. Instead, the system largely meanders near the 70°W longitude corridor while gradually weakening. The 06Z run also produces a particularly intense northwest-side precipitation band Saturday, placing Long Island, New York City, northern New Jersey and southern New England beneath a prolonged rain shield. Overall, the 06Z run does not represent a major departure from 00Z. Both depict a deep coastal cyclone that moves north, stalls south of New England, and slowly weakens. The principal uncertainty remains how far west the trapped circulation ultimately drifts.

They're waiting for the GFS to decide what it wants to do. If the 12z GFS does what the 0z GFS did, then they'll change.

If you don't care, why post? There are people who care. It'll fascinating watching the Titans at MetLife Stadium during a huge wind and rain storm on Sunday afternoon.

Valid 00Z Monday Sep. 28, 8 PM Sunday EDT, the GFS has the center down near the waters south of Long Island / east of New Jersey, while filling rapidly to 999 mb. Compare the evolution: F72: 993 mb, offshore F84: 993 mb, moving west F90: 995 mb, farther west F96: 999 mb, farther west again So this is no longer ambiguous model-map noise. The 00Z GFS explicitly depicts a cyclone that stalls offshore and then tracks back toward the coast while weakening. And the precipitation character changes substantially by F96. The intense compact wraparound band from earlier has weakened considerably, but the circulation is still producing a huge area of rain from NJ/NY through New England. So by Sunday evening the modeled problem has transitioned from a compact, intense coastal cyclone toward a broad, weakening circulation still capable of producing prolonged rainfall. What strikes me most is how much farther the GFS has come compared with the runs we were watching yesterday. The disagreement used to be something like: GFS: northeast and gone. European guidance: trapped, then west. Now the 00Z GFS itself is showing trapped, then west. The exact center, rainfall amounts and timing can absolutely still change. But the synoptic mechanism of a trapped cyclone retrograding toward the Northeast has now survived another GFS cycle, and we're getting into the 3–4 day range.

Out to 72... the storm is stalled. Just completely stalled off of Long Island. About 150 miles SE. Lots of rain and wind for our areas.

Holy crap did the GFS absolutely CAVE to the EURO! This is more west than 18z!

0z EURO out to 24... At F24, I do not see an obvious early Bermuda run. The low is still close enough to the Mid-Atlantic coastal zone that the later interaction with the block is very much alive. God if we got this in 3 months from now this forum would be going nuts.

That darn September sun angle!

Watch 0z GFS hit Bermuda.

It just stalls off the cape. And then, 8 pm Sunday it retrogrades West to Long Island! Just like the EURO had.

This is enough of a shift west that I think either 0z or 12z will bow to the EURO. I'm not saying this thing gives us memories of Sandy and goes into NJ, but I think maybe Eastern Long Island will get the brunt of it. Will it retrograde? That depends on the placement of the high pressure up north and how strong it is.

GFS is west at hr 60

Upton had balls last winter. Maybe they misplaced them when El Nino came. They should find them again because I have faith the 18z GFS is going to cause them to hoist Gale Watches.

This is going to be a FUN winter.

We'll see if the 18z GFS bows to the EURO

Ok, a broken clock is right twice a day. The EURO is king. The EURO AI has performed better than most other models for over a year now.

The last time the Weather Channel was accurate was 1993 on the Storm of the Century.

Also, the ground is pretty saturated from the prior rain storms we've had this summer/autumn. With high winds, I'd be concerned about a lot of trees falling.

12z EURO is the same track its been for a while. Slams it into Long Island and retrogrades west. The low weakens while it does this.