WEEKEND STILL LOOKS GLOOMY, BUT A FEW MODELS RAISE QUESTIONS

Good morning everyone.

A quick look at today through Friday before we move onto the good stuff.

Dry weather and mainly sunny skies will extend through the end of the work week. However, it will turn a few degrees cooler each day, beginning with this afternoon. After a mild day in the 60s yesterday, we return to the mid 50s today. It will also be breezy, with sustained winds 15-20 mph.

Clouds will increase Friday as the weekend storm system approaches from the southwest. Right now, all global models¬† – GFS/ECMWF/CMC – are on board with rain and wind beginning early Saturday, peaking Saturday evening, and tapering off on Sunday. Coastal flooding is a concern as well. Let’s break down each storm facet:

Rainfall:

  • Rainfall amounts of 1-2″ are possible. This could lead to minor street flooding.

Winds:

  • Northeast winds gusts of 30-40 mph are likely on Saturday. Depending on the strength of the storm, gusts to 50 or even slightly higher would be possible.
  • With a saturated ground, this may result in isolated downed trees and tree branches, with isolated power outages.

Coastal flooding:

  • Widespread minor coastal flooding (1-1.5′) with localized moderate coastal flooding (2-2.5′)¬†along the south shore of Nassau/Western Suffolk and possibly Jamaica Bay.
  • Main concern will be with the high tide cycles, starting Friday night and continuing through Sunday morning.
  • Additionally, 10′ surf will be possible along the ocean beaches on Saturday, which could cause erosion.

Now as mentioned, the global models are in good agreement with this scenario playing out. However, the short-term mesoscale models are now beginning to come into frame, and one of them – the NAM – has a different ideas.

Granted the very last frame of this mornings 6z NAM model only reaches Saturday afternoon, but it has the storm racing up the coast much more rapidly. Thus, the rain would begin on Friday night and start to taper off Saturday afternoon with drier air moving in. It would still be windy, but they would be curtailed a little more. This would mean improved conditions for Sunday. This is certainly a situation I will be keeping a close eye on in the next 24 hours.

High temperatures over the weekend get to 50 at best regardless of the storm variables, so I think it’s safe to say that indoor plans will be ideal. Even once the storm departs, we aren’t completely out of the woods. With a large dip in the jet stream still in place, another wave of energy will dig down across the central U.S. and develop into a second coastal storm during the Monday-Tuesday time frame.

Check back in to weatherlongisland.com this evening for my early Halloween forecast.
*Hint: not as spooky as the weekend!

Meteorologist Geoff Bansen