Have been discussing this storm a bit in the weather pattern thread, but since it's absolutely certain we're going to be hit with a major nor'easter on Thursday into Friday, figured it was time for a new thread on this. This is still looking like a very powerful system (1-1.5" of liquid precip falling) to impact our area Thursday (especially Thursday afternoon/night) into Friday morning, but the models are almost all showing little to no snow along and SE of the 95 corridor, i.e., probably all rain. However, most of the models are showing a fairly sharp temperature and precip gradient as one moves NW of 95 (especially N of 78), such that there could possibly accumulating snow, followed by heavy rain 15-20 miles inland of 95 and N or 78 (i.e., NW of 287 from 78 to Suffern) and mostly snow/sleet well NW of 95, especially for the usual areas, like Sussex/Warren/NW Morris, NW Passaic, the Poconos, and the Hudson Valley. Anywhere that is mostly snow could easily pick up 6-10" or more - some sleet and freezing rain are possible with this system too in these areas. But the good news is that most of the ski resorts from NE PA through interior NY/New England should pick up substantial snowfall.
We're still 3+ days away from the main precip (relative to this morning's global model runs) so much could change, i.e., there could still be a bit of snow accumulating snow (especially early in the storm) along 95 prior to any changeover to rain, if the primary low approaching from the Ohio Valley weakens more quickly than forecast, allowing the secondary coastal low which forms to potentially take a more offshore track, bringing in colder air (there has been a bit of a trend towards colder solutions like this, given the strong blocking in place, which should make it hard for the primary low to stay strong). By the same token, if the primary is stronger, that could lead to more warm air moving in off the ocean, leading to much less snow, even well NW of 95. Still too early for actual forecasts. A couple of things we have high confidence in, however: there will be lots of precip and some substantial winds (could be advisory levels, especially near the coast), plus some minor tidal flooding could occur. The latest discussion from the NWS-Philly does a nice job outlining the meteorology and the potential outcomes and the 2nd link is to the AmericanWx thread on this, including sage input from Walt Drag (one of the best from the NWS, now retired).
https://forecast.weather.gov/produc...&format=CI&version=1&glossary=1&highlight=off
https://www.americanwx.com/bb/topic/58571-1215-1216-possible-coastalwinter-storm/
LONG TERM /THURSDAY THROUGH MONDAY/...
Global guidance continues to show a fairly significant coastal storm
impacting the region Thursday morning through at least early Friday.
The general thinking remains the same with this afternoon`s forecast
update: this system will have the potential to bring the area heavy
precipitation, strong winds, and potentially even some coastal
flooding issues. That said, there is still a lot of uncertainty
regarding the details such as exact timing and precipitation types.
In the big picture though, the latest GFS, GEM, and ECMWF all depict
a large lumbering upper level system moving out of the central CONUS
with a primary low over the midwest giving way to a secondary low
developing over the SE CONUS and tracking northeast right along the
coast Thursday through Friday as it deepens. If this track were to
verify, it would make it unlikely for the I-95 corridor to see a
significant snow event but the potential is still there farther
north and west towards the southern Poconos and NW New Jersey.
With that said, the timing of precip onset will be key Thursday
morning, which could determine whether or not we see a messy wintry
mix for the morning rush hour. Precip beginning earlier in the day
could run into the cold antecedent cold airmass, resulting in a
period of a wintry mix of snow, sleet, and freezing rain mixed in
with rain for the I-95 corridor early to mid morning before
switching over to all rain by the afternoon. A slower start to
precip would be most ideal to remain predominantly rain along and
south of the I-95 corridor, but areas north and west could still
see a wintry mix. Again, high uncertainty remains with the precip
type forecast for early Thursday.
Once we get through the morning and switch over to mostly rain
Thursday afternoon, we will begin to see the brunt of the storm with
heavy rain ramping up into Thursday night across the south with
still a potential for wintry precip north and west across extreme
northeast PA and northwest NJ. East winds will also ramp up through
with the potential for gusts over 30 mph inland and over 40 mph
along the coast. Wind and rain will continue through Friday morning
before the system finally begins to depart the area southwest to
northeast by late Friday into early Saturday.
We're still 3+ days away from the main precip (relative to this morning's global model runs) so much could change, i.e., there could still be a bit of snow accumulating snow (especially early in the storm) along 95 prior to any changeover to rain, if the primary low approaching from the Ohio Valley weakens more quickly than forecast, allowing the secondary coastal low which forms to potentially take a more offshore track, bringing in colder air (there has been a bit of a trend towards colder solutions like this, given the strong blocking in place, which should make it hard for the primary low to stay strong). By the same token, if the primary is stronger, that could lead to more warm air moving in off the ocean, leading to much less snow, even well NW of 95. Still too early for actual forecasts. A couple of things we have high confidence in, however: there will be lots of precip and some substantial winds (could be advisory levels, especially near the coast), plus some minor tidal flooding could occur. The latest discussion from the NWS-Philly does a nice job outlining the meteorology and the potential outcomes and the 2nd link is to the AmericanWx thread on this, including sage input from Walt Drag (one of the best from the NWS, now retired).
https://forecast.weather.gov/produc...&format=CI&version=1&glossary=1&highlight=off
https://www.americanwx.com/bb/topic/58571-1215-1216-possible-coastalwinter-storm/
LONG TERM /THURSDAY THROUGH MONDAY/...
Global guidance continues to show a fairly significant coastal storm
impacting the region Thursday morning through at least early Friday.
The general thinking remains the same with this afternoon`s forecast
update: this system will have the potential to bring the area heavy
precipitation, strong winds, and potentially even some coastal
flooding issues. That said, there is still a lot of uncertainty
regarding the details such as exact timing and precipitation types.
In the big picture though, the latest GFS, GEM, and ECMWF all depict
a large lumbering upper level system moving out of the central CONUS
with a primary low over the midwest giving way to a secondary low
developing over the SE CONUS and tracking northeast right along the
coast Thursday through Friday as it deepens. If this track were to
verify, it would make it unlikely for the I-95 corridor to see a
significant snow event but the potential is still there farther
north and west towards the southern Poconos and NW New Jersey.
With that said, the timing of precip onset will be key Thursday
morning, which could determine whether or not we see a messy wintry
mix for the morning rush hour. Precip beginning earlier in the day
could run into the cold antecedent cold airmass, resulting in a
period of a wintry mix of snow, sleet, and freezing rain mixed in
with rain for the I-95 corridor early to mid morning before
switching over to all rain by the afternoon. A slower start to
precip would be most ideal to remain predominantly rain along and
south of the I-95 corridor, but areas north and west could still
see a wintry mix. Again, high uncertainty remains with the precip
type forecast for early Thursday.
Once we get through the morning and switch over to mostly rain
Thursday afternoon, we will begin to see the brunt of the storm with
heavy rain ramping up into Thursday night across the south with
still a potential for wintry precip north and west across extreme
northeast PA and northwest NJ. East winds will also ramp up through
with the potential for gusts over 30 mph inland and over 40 mph
along the coast. Wind and rain will continue through Friday morning
before the system finally begins to depart the area southwest to
northeast by late Friday into early Saturday.
