I am running a bit late today, by choice, as I wanted to wait for modeling data to come in. Based on NHC's latest disco, this could be upgraded at 5 PM, and if it is, esp if watches or warnings are issued for our coastal counties, I may jump in later on for a quick update.
Just to let everyone know, I won't be investing much time in the long term today, as I am only one person and an emergent tropical threat in the short term overrides anything in the long term. For now, it also looks like a calming trend in the wx after Tuesday.
Currently: High pressure ridging extending from WV to offshore (at about the same latitude) is keeping the area dry today. The combination of this high and subsidence ahead of the tropical low developing the south should keep thunderstorms out of the region today. While it is not totally impossible for a rogue cell to develop, the chances of t-storms are too low to mention in the forecast. Speaking of the tropical low, it was analyzed developing near Cape Hatteras or just S of there.
First, the easy part, for tonight, it stays warm and muggy. I don't think any precipfrom the tropical system gets into the area before dawn, so I'll keep it dry. As for temps, as tropical air surges N ahead of the sys, it will be a very warm and muggy night. I'll go a cpl deg abv temp gdnc, so look for lows of only 70-75!
Now let's do a little model overview for the upcoming system: Models have actually come into good agreement this afternoon, regarding the evolution and track of the upcoming system. Most now take it straight up the NJ coast, with the outliers being the GFS (which takes it up the Delaware River), and the RGEM, which takes it to Nantucket. My preferred track at this time, due to meteorology, plus normal model trends, is a bit east of consensus- close to the GGEM and GEM-LAM models, which would be just E of the NJ coast, to a "landfall" ard Brooklyn to Nassau County, then roughly up I 91 or so, or just W of there.
Normally, a well-organized tropical system has the bulk of the high winds on the East side of the storm, with the bulk of the rainfall on the West side. While this can still be true for this one, I doubt it will fit the classification of a "well-organized tropical cyclone", since it does not have enough time over warm waters to get to that level. Therefore, the rainfall and wind distribution should be more uniform than that of a well-organized tropical cyclone.
The overall trend has been to slow this system down. Since it is developing tropically, plus given the fact that steering currents have been weak of late, I don't see any reason to doubt this trend.
There is a lot of available moisture in the atmosphere, and precipitable waters are very high. This means that rainfall will probably be heavier than modeled.
Another wild card is convection. Tropical systems are convective by nature, since they are made of t-storms. The SPC has already placed the area in a marginal risk for svr storms, w/the highest threat being weak tornadoes. Tornadoes typically occur E of the track of tropical cyclones, as well. Another wild card regarding convection is that someone could get a lot more rain than fcst at the expense of another area, esp if there is any training.
So now, let's get into the actual forecast. Feeder bands of rain may make it into SW CT by dawn, and may take until midday to get to NE CT. As far as rainfall amts, based on the modeled track of the storm, the heaviest amts should be acrs SW CT, w/lighter amts the further NE you head. Due to precipitable waters being very high and the convective nature to the pcpn, I've gone higher than gdnc numbers on amts. Xpct 2-3" of rain, w/locally higher amts psbl for much of the state. Most of the really high totals (4-5" type stuff) shud be W of I 91, but even a slight shift E could bring those totals further E.
As for winds, I am not looking for ridiculous winds, simply because this system will not have a chance to get really strong. Even having said that though, I could still see coastal areas gusting to 30-35 MPH, so winds will not be a complete non-factor, either.
Finally for temperatures tomorrow, i went a couple degrees below guidance, due to clouds and rainfall. Regardless, it will be very humid and muggy. Xpct high temps in the upper 70s.
On Saturday, the storm will pull out of the area. However, an upper level low will rotate down from the Great Lakes. Once again, the SPC has placed the area in a marginal risk for svr storms, altho the focus shifts more to a hail threat. Another threat on Sat will be torrential downpours, as once again, steering currents are weak and precipitable waters are very high. There is most certainly a flood potential, esp if the same areas that get pounded tmrw get hvy storms on Sat.
Like I said up top, I am not going to go into too much detail in the long term. There is too much going on in the short term and only so many hrs in a day. But the main threat for storms in the long term is Monday. It looks like another potential heavy rain maker. After that, we shud calm down for a while regarding storms. Temps look abv norm thru the pd, but I'm not ready to bite on xtreme warmth.
Today's graphics will be something different. For now, I'll just post the NHC map. If it gets named by 5 PM or any watches/warnings get out, I'll add them! On this map, you can see a similar line of thinking to my own, altho I might be 30 mi W of them. Lo near Hatteras tracks up to near LI by late tmrw nite.