OT: Minor to Moderate Snow/Mix Likely Sat Evening (2/8) through Sun am

[RU848789]

Posting Pivotal maps in mixed snow/sleet events is misleading, as it makes it look like there's no frozen precip for areas getting significant sleet (i.e., most areas showing less than 3-4" of pure snow). For the GFS, the comparison of the TT and Pivotal maps are also showing more sleet (a bit like the NAM) where the sleet amount = (TT "snow" (which includes 10:1 sleet) - Pivotal pure snow)/3; when they show the same amount of "snow" that means no sleet. Would be nice to have a sleet map and a pure snow map.

Finally found this, which really shows well the amounts of snow, sleet, freezing rain and rain for the 12Z NAM for selected locations. For Newark, it has 0.54" total precip, which includes 1.7" of snow (assumes 10:1 ratio), about 1.1" of sleet (from 0.37" of sleet as liquid and using a 3:1 ratio) and no freezing rain or plain rain.

For Philly, it has 0.69" total precip, which includes 1.4" of snow, about 0.3" of sleet (from 0.11" of sleet as liquid and using a 3:1 ratio), but it also shows 0.42" of freezing rain (and no plain rain), which would be just terrible. Rule of thumb is maybe 1/2 to 2/3 of freezing rain precip actually accretes on sub-32F surfaces (some runs off, especially if precip is moderate to heavy; drizzle accumulates much better), meaning maybe 0.25" of ice accretion, which is close to the 0.17" of accumulated freezing rain from the NWS forecast.

Biggest take home message is no plain rain, so this will be quite impactful even for areas south of 78 which might get a lot less pure snow, as sleet and freezing rain are as bad or worse. Even AC is only showing half of the 0.6" of total precip as plain rain. Of course, this is just the NAM model verbatim and the actual outcome might be much different as per the NWS with more snow and less sleet/freezing rain for most.

 

[bac2therac]

Most people aren't concerned with mass...they look and see what's out there..a couple of inches of snow including sleet

Most peeps just need to stay off the roads between 4pm and midnight and things should be fine upon wakey unless we really get hit with freezing rain

Not a long duration event

 

[RocktheRac]

Most people aren't concerned with mass...they look and see what's out there..a couple of inches of snow including sleet

Most peeps just need to stay off the roads between 4pm and midnight and things should be fine upon wakey unless we really get hit with freezing rain

Not a long duration event

Exactly. I have some turd customers that don't want the driveways plowed unless there is 3 or more inches so if we get 1 inch of snow and then sleet good luck trying to use Numbers mass explanation that there is really 5 inches.

 

[RU848789]

Most people aren't concerned with mass...they look and see what's out there..a couple of inches of snow including sleet

Most peeps just need to stay off the roads between 4pm and midnight and things should be fine upon wakey unless we really get hit with freezing rain

Not a long duration event

Nothing will melt overnight with temps at or below 32F for most until 9-10 am, so conditions in the morning will likely still be treacherous with 2" or so of snow/sleet then maybe 0.2" of ice on top of that...for CNJ N of 276/195 as per the recent NWS advisories, below, as it looks like the NWS is going with the sleetier/icier forecast (for areas south of 276/195 along 95 the forecast is for ~1" of snow/sleet plus 0.1-0.2" freezing rain while for coastal areas it's 2" of snow/sleet + 0.1" freezing rain). 2" of sleet/snow with 0.2" of ice would have the equivalent frozen mass (the freezing rain will be absorbed by the sleet/snow, not melt it) of ~6" of snow on all surfaces. This could be a shitstorm if places get 1/4" of ice accretion as per the NWS and some models which show even more. I think everyone would rather have all snow, but it's looking like a mix for anyone south of 78 and maybe south of 80.

Edit: added in the newly updated NWS-Philly snow/ice maps, showing the significant deceases in snowfall forecasts for everyone, but people should know that the decreased snow will be replaced by sleet, not rain, so the frozen mass on the ground will be about the same and the amount of freezing rain forecast hasn't changed much (and that will add to the frozen mass on the ground).

https://forecast.weather.gov/wwamap/wwatxtget.php?cwa=PHI&wwa=winter weather advisory

URGENT - WINTER WEATHER MESSAGE
National Weather Service Mount Holly NJ
101 PM EST Fri Feb 7 2025

NJZ009-010-012-015-PAZ054-061-062-105-106-080715-
/O.NEW.KPHI.WW.Y.0007.250208T2000Z-250209T1100Z/
Hunterdon-Somerset-Middlesex-Mercer-Carbon-Lehigh-Northampton-
Upper Bucks-Lower Bucks-
Including the cities of Doylestown, Trenton, Bethlehem,
Somerville, New Brunswick, Flemington, Jim Thorpe, Perkasie,
Chalfont, Allentown, Morrisville, and Easton
101 PM EST Fri Feb 7 2025

...WINTER WEATHER ADVISORY IN EFFECT FROM 3 PM SATURDAY TO 6 AM EST
SUNDAY...

* WHAT...Mixed precipitation expected. Total snow and sleet
accumulations up to two inches and ice accumulations up to two
tenths of an inch.



URGENT - WINTER WEATHER MESSAGE
National Weather Service Mount Holly NJ
101 PM EST Fri Feb 7 2025

NJZ013-020-022-027-080715-
/O.NEW.KPHI.WW.Y.0007.250208T1700Z-250209T0700Z/
Western Monmouth-Ocean-Atlantic-Southeastern Burlington-
Including the cities of Jackson, Wharton State Forest, Freehold,
and Hammonton
101 PM EST Fri Feb 7 2025

...WINTER WEATHER ADVISORY IN EFFECT FROM NOON SATURDAY TO 2 AM EST
SUNDAY...

* WHAT...Mixed precipitation expected. Total snow and sleet
accumulations up to two inches and ice accumulations around one
tenth of an inch.



URGENT - WINTER WEATHER MESSAGE
National Weather Service Mount Holly NJ
101 PM EST Fri Feb 7 2025

NJZ001-007-008-PAZ055-080715-
/O.NEW.KPHI.WW.Y.0007.250208T2000Z-250209T1100Z/
Sussex-Warren-Morris-Monroe-
Including the cities of Morristown, Washington, Newton, and
Stroudsburg
101 PM EST Fri Feb 7 2025

...WINTER WEATHER ADVISORY IN EFFECT FROM 3 PM SATURDAY TO 6 AM EST
SUNDAY...

* WHAT...Mixed precipitation expected. Total snow and sleet
accumulations between 2 and 4 inches and ice accumulations up to
one tenth of an inch.


URGENT - WINTER WEATHER MESSAGE
National Weather Service Mount Holly NJ
101 PM EST Fri Feb 7 2025

DEZ001-NJZ016>019-PAZ060-070-071-101>104-080715-
/O.NEW.KPHI.WW.Y.0007.250208T1700Z-250209T1100Z/
New Castle-Salem-Gloucester-Camden-Northwestern Burlington-Berks-
Delaware-Philadelphia-Western Chester-Eastern Chester-Western
Montgomery-Eastern Montgomery-
Including the cities of Honey Brook, Moorestown, West Chester,
Oxford, Pottstown, Norristown, Wilmington, Camden, Mount Holly,
Collegeville, Reading, Media, Glassboro, Lansdale, Pennsville,
Kennett Square, Cherry Hill, and Philadelphia
101 PM EST Fri Feb 7 2025

...WINTER WEATHER ADVISORY IN EFFECT FROM NOON SATURDAY TO 6 AM EST
SUNDAY...

* WHAT...Mixed precipitation expected. Total snow and sleet
accumulations up to one inch and ice accumulations between one
tenth and two tenths of an inch.

 

[RU848789]

Exactly. I have some turd customers that don't want the driveways plowed unless there is 3 or more inches so if we get 1 inch of snow and then sleet good luck trying to use Numbers mass explanation that there is really 5 inches.

They're going to wish you had plowed 2-3" of heavy slop that is really like 5-6" of snow - use some science with them, as mass is far more important for removal than depth and for difficulty driving - look at all the accidents we had with ~1/2" of sleet/snow yesterday - this will make that look like child's play.

 

[bac2therac]

Nothing will melt overnight with temps at or below 32F for most until 9-10 am, so conditions in the morning will likely still be treacherous with 2" or so of snow/sleet then maybe 0.2" of ice on top of that...for CNJ N of 276/195 as per the recent NWS advisories, below, as it looks like the NWS is going with the sleetier/icier forecast (for areas south of 276/195 along 95 the forecast is for ~1" of snow/sleet plus 0.1-0.2" freezing rain while for coastal areas it's 2" of snow/sleet + 0.1" freezing rain). 2" of sleet/snow with 0.2" of ice would have the equivalent frozen mass (the freezing rain will be absorbed by the sleet/snow, not melt it) of ~6" of snow on all surfaces. This could be a shitstorm if places get 1/4" of ice accretion as per the NWS and some models which show even more. I think everyone would rather have all snow, but it's looking like a mix for anyone south of 78 and maybe south of 80.

https://forecast.weather.gov/wwamap/wwatxtget.php?cwa=PHI&wwa=winter weather advisory

URGENT - WINTER WEATHER MESSAGE
National Weather Service Mount Holly NJ
101 PM EST Fri Feb 7 2025

NJZ009-010-012-015-PAZ054-061-062-105-106-080715-
/O.NEW.KPHI.WW.Y.0007.250208T2000Z-250209T1100Z/
Hunterdon-Somerset-Middlesex-Mercer-Carbon-Lehigh-Northampton-
Upper Bucks-Lower Bucks-
Including the cities of Doylestown, Trenton, Bethlehem,
Somerville, New Brunswick, Flemington, Jim Thorpe, Perkasie,
Chalfont, Allentown, Morrisville, and Easton
101 PM EST Fri Feb 7 2025

...WINTER WEATHER ADVISORY IN EFFECT FROM 3 PM SATURDAY TO 6 AM EST
SUNDAY...

* WHAT...Mixed precipitation expected. Total snow and sleet
accumulations up to two inches and ice accumulations up to two
tenths of an inch.



URGENT - WINTER WEATHER MESSAGE
National Weather Service Mount Holly NJ
101 PM EST Fri Feb 7 2025

NJZ013-020-022-027-080715-
/O.NEW.KPHI.WW.Y.0007.250208T1700Z-250209T0700Z/
Western Monmouth-Ocean-Atlantic-Southeastern Burlington-
Including the cities of Jackson, Wharton State Forest, Freehold,
and Hammonton
101 PM EST Fri Feb 7 2025

...WINTER WEATHER ADVISORY IN EFFECT FROM NOON SATURDAY TO 2 AM EST
SUNDAY...

* WHAT...Mixed precipitation expected. Total snow and sleet
accumulations up to two inches and ice accumulations around one
tenth of an inch.



URGENT - WINTER WEATHER MESSAGE
National Weather Service Mount Holly NJ
101 PM EST Fri Feb 7 2025

NJZ001-007-008-PAZ055-080715-
/O.NEW.KPHI.WW.Y.0007.250208T2000Z-250209T1100Z/
Sussex-Warren-Morris-Monroe-
Including the cities of Morristown, Washington, Newton, and
Stroudsburg
101 PM EST Fri Feb 7 2025

...WINTER WEATHER ADVISORY IN EFFECT FROM 3 PM SATURDAY TO 6 AM EST
SUNDAY...

* WHAT...Mixed precipitation expected. Total snow and sleet
accumulations between 2 and 4 inches and ice accumulations up to
one tenth of an inch.


URGENT - WINTER WEATHER MESSAGE
National Weather Service Mount Holly NJ
101 PM EST Fri Feb 7 2025

DEZ001-NJZ016>019-PAZ060-070-071-101>104-080715-
/O.NEW.KPHI.WW.Y.0007.250208T1700Z-250209T1100Z/
New Castle-Salem-Gloucester-Camden-Northwestern Burlington-Berks-
Delaware-Philadelphia-Western Chester-Eastern Chester-Western
Montgomery-Eastern Montgomery-
Including the cities of Honey Brook, Moorestown, West Chester,
Oxford, Pottstown, Norristown, Wilmington, Camden, Mount Holly,
Collegeville, Reading, Media, Glassboro, Lansdale, Pennsville,
Kennett Square, Cherry Hill, and Philadelphia
101 PM EST Fri Feb 7 2025

...WINTER WEATHER ADVISORY IN EFFECT FROM NOON SATURDAY TO 6 AM EST
SUNDAY...

* WHAT...Mixed precipitation expected. Total snow and sleet
accumulations up to one inch and ice accumulations between one
tenth and two tenths of an inch.

the roads should be generally ok because they will have about 12 hours to work on them....people getting out the door at 9 for a 2 inch snow/sleet event should be okay unless you live in the sticks or as i said we get a ton of freezing rain....most models have precip winding down by 3 am except the ukie which is on an island with a later start time and later finish

also as I thought...keeping central jersey in the up to 2 inch total of snow/sleet...those 3-5 inch amounts you throw around as consensus earlier is why I call your snow bias out...same thing happened with the last storm...

 

[bac2therac]

They're going to wish you had plowed 2-3" of heavy slop that is really like 5-6" of snow - use some science with them, as mass is far more important for removal than depth and for difficulty driving - look at all the accidents we had with ~1/2" of sleet/snow yesterday - this will make that look like child's play.

the accidents happened because the storm was actually happening at the same time as morning rush..that wont be the issue with this one with the storm ending likely by 3 am as salters and plowers will have had time to work on the roads as long as we dont have a prolonged freezing rain event.

 

[bac2therac]

 

[RocktheRac]

They're going to wish you had plowed 2-3" of heavy slop that is really like 5-6" of snow - use some science with them, as mass is far more important for removal than depth and for difficulty driving - look at all the accidents we had with ~1/2" of sleet/snow yesterday - this will make that look like child's play.

They are mostly concerned about being able to get out of their driveways. I have the upmost confidence they will not get into an accident in their driveway. After that they are on their own.

 

[bac2therac]

They are mostly concerned about being able to get out of their driveways. I have the upmost confidence they will not get into an accident in their driveway. After that they are on their own.

its up to the customer...and they are always right...affluent area but they are actually the cheapest..its funny because the same peeps dont have an issue with splurging for a $150 dinner for 2 a few times of month but then think their lawn should be cut or the driveway plowed for $40

 

[RAHWAYBOB]

Planning on a trip from Rahway to AC Sunday afternoon. I see multiple forecasts. Will it be so bad that driving will be hazardous?

 

[DJ Spanky]

thats a basic 2-3 type event for central jersey...

What's this "central jersey" you speak of?

 

[bac2therac]

the plot thickens as both the 18z hrrr and nam have bumped snow totals...again 8 hour storm...quick thump of snow to ice

 

[RU848789]

Planning on a trip from Rahway to AC Sunday afternoon. I see multiple forecasts. Will it be so bad that driving will be hazardous?

Major highways would likely be fine by then, but side roads could still be slick, especially if they weren't plowed, although temps in the mid/upper 30s by afternoon will help.

 

[RAHWAYBOB]

Major highways would likely be fine by then, but side roads could still be slick, especially if they weren't plowed, although temps in the mid/upper 30s by afternoon will help.

Thanks!

 

[RU848789]

Wow, NAM-ed in some ways by the 18Z NAM, with double the QPF and a lot more snow than the past few runs for most, plus a lot of sleet and a bit of ZR but very little rain. Will take. Verbatim, for my house in the Edison area, that's 1" of QPF consisting of about 4" of pure snow (0.4" QPF) on the front end, followed by 2" of sleet (5" of equivalent 10:1 snow or 0.5" QPF, as sleet comparing the TT/Pivotal maps) and maybe 0.1" of ZR, so ~10" of 10:1 snow condensed down to maybe 5" of 5:1 slush (the ZR will just be absorbed into the pack). While I'd love 10" of snow, where do I sign up for this. Funny having to use 4 graphics for a forecast. HRRR also came in snowier/colder, so hard to say what's going to happen and if this NAM run is just a blip or an indication of a bigger front end thump and juicier system.

 

[RU848789]

NWS-NYC issued advisories for 3-5" of snow/sleet and a glaze of freezing rain for Union/Essex/Hudson and SE Passaic/SE Bergen in NJ and all of NYC/LI, plus southern Westchester and they issued warnings for 5-7" of snow with maybe a glaze of ice for NW Passaic, NW Bergen and all of the NY/CT counties north of the Tappan Zee. The updated regional NWS map is below and clearly, the NWS-NYC and NWS-Philly offices are not in sync. Look at the bondary between Sussex and Orange, where it goes from 3-4" to 6-8 by magically crossing into NY; similarly NE Morris is at 2-3" and is up against 4-6" amounts in adjacent Essex/Passaic. I would think maybe the NWS-Philly might bump amounts back up to align them better (or vice versa, but the NWS-NYC just issued their info).

URGENT - WINTER WEATHER MESSAGE
National Weather Service New York NY
314 PM EST Fri Feb 7 2025

Eastern Passaic-Hudson-Eastern Bergen-Western Essex-Eastern Essex-
Western Union-Eastern Union-Southern Westchester-New York
(Manhattan)-Bronx-Richmond (Staten Island)-Kings (Brooklyn)-
Northwest Suffolk-Northeast Suffolk-Southwest Suffolk-Southeast
Suffolk-Northern Queens-Northern Nassau-Southern Queens-Southern
Nassau-
314 PM EST Fri Feb 7 2025

...WINTER WEATHER ADVISORY IN EFFECT FROM 5 PM SATURDAY TO 11 AM EST
SUNDAY...

* WHAT...Snow expected. Total snow and sleet accumulations between 3
and 5 inches. A light glaze of ice is also possible.



National Weather Service New York NY
314 PM EST Fri Feb 7 2025

Northern Fairfield-Northern New Haven-Northern Middlesex-Northern
New London-Southern Fairfield-Southern New Haven-Southern
Middlesex-Southern New London-Western Passaic-Western Bergen-
Orange-Putnam-Rockland-Northern Westchester-
314 PM EST Fri Feb 7 2025

...WINTER STORM WARNING IN EFFECT FROM 5 PM SATURDAY TO 11 AM EST
SUNDAY...

* WHAT...Heavy snow expected. Total snow accumulations between 5 and
7 inches. A light glaze of ice is also possible.

 

[RUhasarrived]

Lee Goldberg has it flaking at 6PM,then ramping up from 8PM to 1 AM.

I guess that the Meadowlands is off for tomorrow night.

 

[MadRU]

Thanks for the Union County updates

 

[bac2therac]

yikes..the 18z gfs gives a middle finger to the nam

 

[bac2therac]

 

[RU#1fan]

Up in Northern Vermont for a Pond Hockey Tournament and overnight Saturday could get a lot of snow from this system…. 8 to 10 inches

 

[RU848789]

NWS-NYC issued advisories for 3-5" of snow/sleet and a glaze of freezing rain for Union/Essex/Hudson and SE Passaic/SE Bergen in NJ and all of NYC/LI, plus southern Westchester and they issued warnings for 5-7" of snow with maybe a glaze of ice for NW Passaic, NW Bergen and all of the NY/CT counties north of the Tappan Zee. The updated regional NWS map is below and clearly, the NWS-NYC and NWS-Philly offices are not in sync. Look at the bondary between Sussex and Orange, where it goes from 3-4" to 6-8 by magically crossing into NY; similarly NE Morris is at 2-3" and is up against 4-6" amounts in adjacent Essex/Passaic. I would think maybe the NWS-Philly might bump amounts back up to align them better (or vice versa, but the NWS-NYC just issued their info).

URGENT - WINTER WEATHER MESSAGE
National Weather Service New York NY
314 PM EST Fri Feb 7 2025

Eastern Passaic-Hudson-Eastern Bergen-Western Essex-Eastern Essex-
Western Union-Eastern Union-Southern Westchester-New York
(Manhattan)-Bronx-Richmond (Staten Island)-Kings (Brooklyn)-
Northwest Suffolk-Northeast Suffolk-Southwest Suffolk-Southeast
Suffolk-Northern Queens-Northern Nassau-Southern Queens-Southern
Nassau-
314 PM EST Fri Feb 7 2025

...WINTER WEATHER ADVISORY IN EFFECT FROM 5 PM SATURDAY TO 11 AM EST
SUNDAY...

* WHAT...Snow expected. Total snow and sleet accumulations between 3
and 5 inches. A light glaze of ice is also possible.



National Weather Service New York NY
314 PM EST Fri Feb 7 2025

Northern Fairfield-Northern New Haven-Northern Middlesex-Northern
New London-Southern Fairfield-Southern New Haven-Southern
Middlesex-Southern New London-Western Passaic-Western Bergen-
Orange-Putnam-Rockland-Northern Westchester-
314 PM EST Fri Feb 7 2025

...WINTER STORM WARNING IN EFFECT FROM 5 PM SATURDAY TO 11 AM EST
SUNDAY...

* WHAT...Heavy snow expected. Total snow accumulations between 5 and
7 inches. A light glaze of ice is also possible.

The NWS did a little bit of alignment to eliminate the worst discontinuity, as the NWS-NYC put a strip of 4-6" in SW Orange up against NE Sussex's 3-4" swath, but they left SE Morris at 2-3" adjacent to W Essex/Union at 4-6". Whatever. Still think NWS-Philly is at least a bit underdone, as it would be very unusual for NYC/Union/Hudson/Essex to have 4-6", while Sussex/Morris/Warren all have 2-3"/3-4" - this only makes sense if the NWS-Philly counties get a fair amount more sleet or a fair amount less precip, both of which seem possible but unlikely. An updated ice map is also below as is a link to the NWS-Philly briefing.

chrome-extension://efaidnbmnnnibpcajpcglclefindmkaj/https://www.weather.gov/media/phi/current_briefing.pdf

Anyway, let's see where tonight's models go and then we'll see the actual storm tomorrow where we'll see how much of a front end thump of snow materializes starting in SWNJ/SEPA and if it progresses NE into CNJ/NYC without much sleet or if we see an early change to sleet. Those things will determine how much snow/sleet most get and it'll be a fine line, as the heaviest precip will be from about 6 pm to midnight for most, which is not a long duration event, so losing an hour of snow or keeping it during the height of the storm will make a significant difference. And then the next question becomes how much actual freezing rain do we see and where? Getting 0.1-0.2" of ice could make for very difficult walking/driving conditions on untreated surfaces.

 

[WhiteBus]

Philadelphia is looking at .25in of sleet/ice. System is done by 1am, maybe earlier. Let's see what changes overnight!