12/2 Cold Rain and High Elevation Snow

[bncho]

6 minutes ago, Weather Will said:

WB 3K NAM is cooler this run, but still just rain east of the mountains.  Comparing 925 and 850 to 18Z.

step in the correct driection

[jayyy]

Both NAMs continue to hate this system and insist we torch at 850

Kind of makes sense given the high is sliding east off the coast — a SE flow - on December 2nd

[jayyy]

Honestly, I’d be content with 2” of snow up this way at this rate. Trends aren’t encouraging

[MillvilleWx]

3 hours ago, mappy said:

If you make your way towards me there’s a great diner called New Freedom Family Diner just up into PA 

Adding to the list!! Thanks Mappy  

[WEATHER53]

High not running off coast as fast 

[high risk]

39 minutes ago, rjvanals said:

Both NAMs continue to hate this system and insist we torch at 850

        This is bothering me a lot, as the NAMs are usually the colder solutions.  I think we're still in the range where the NAM could be having synoptic issues, but if it continues on Monday to keep the accumulations further northwest of the I-95 corridor, I'm going to guess it's right.   The faster onset, shown by the GFS and its hi-res HiResW FV3, would help a ton here, although even where it shows snow, the thermal profile has pretty much zero margin for error.

[Ji]

WB 3K NAM is cooler this run, but still just rain east of the mountains.  Comparing 925 and 850 to 18Z.

What’s the difference between a purple zero and a white zero?

[bncho]

5 minutes ago, Ji said:

What’s the difference between a purple zero and a white zero?

below freezing and above freezing, almost like 31.8f vs 32.3f

[SnowenOutThere]

19 minutes ago, high risk said:

        This is bothering me a lot, as the NAMs are usually the colder solutions.  I think we're still in the range where the NAM could be having synoptic issues, but if it continues on Monday to keep the accumulations further northwest of the I-95 corridor, I'm going to guess it's right.   The faster onset, shown by the GFS and its hi-res HiResW FV3, would help a ton here, although even where it shows snow, the thermal profile has pretty much zero margin for error.

I mean this sounding from the Catoctins really says it all. Though, it appears if you're able to keep the column cool it will be dumping with a saturated atmosphere up to 500mb and good lift in the DGZ

[Weather Will]

WB 0Z RDPS (less precip.)

[bncho]

if taken verbatim, RDPS zr in the metros might be an issue with these temperatures

[Weather Will]

WB 0Z GFS also a little drier.

[Interstate]

GFS keeps the northern crew happy

[Weather Will]

Temps stay at or below freezing   until 1pm on latest GFS in my area.  Icy Tuesday morning setting up.

[Ji]

Temps stay at or below freezing   until 1pm on latest GFS in my area.  Icy Tuesday morning setting up.

Canadian still unusable
?

[wxmeddler]

38 minutes ago, bncho said:

if taken verbatim, RDPS zr in the metros might be an issue with these temperatures

Heavy Freezing Rain at 30 deg isn't actually a huge problem on the surface as most make it out to be. Too much latent heat release happening. Trees / Power-lines are a concern, but you really need to be 28 or below for stuff to stick in moderate to heavy rain. The worst case is <28 and light rain, that's when you're in trouble.

I think we're seeing a trend north and west with the WAA. If the surface holds at 30, might be few isolated areas that are a mess, if it gets to 32, we'll be fine disappointed.

[87storms]

8 minutes ago, Weather Will said:

Temps stay at or below freezing   until 1pm on latest GFS in my area.  Icy Tuesday morning setting up.

Yea, low level cold air can take forever to scour out. The issue is upstairs. That hp is just racing east, so there’s not gonna be much resistance to the waa. I think an inch stat starter would be a win in this setup.

[notvirga!]

Gfs was way north and now it’s the southernmost solution switching places with euro. Seem to remember them flipping a lot like that last year

[bncho]

CMC decent solution.

[Weather Will]

WB 0Z EURO; about as bad as the Commanders game.

[wxmeddler]

This is ugly. 850 trough over the GL/OV stronger, and we've gone from 20kts of 850 overrunning to 40kts, and further west. Weenies avert your eyes.

[Chris78]

WWA's up for Northern and western areas.

 

[yoda]

30 minutes ago, Chris78 said:

WWA's up for Northern and western areas.

 

URGENT - WINTER WEATHER MESSAGE
National Weather Service Baltimore MD/Washington DC
1238 AM EST Mon Dec 1 2025

...FIRST WIDESPREAD WINTER EVENT OF THE SEASON...

.Precipitation is expected to overspread the area after midnight
tonight from southwest to northeast. While precipitation is likely
to start as snow areawide, it is expected to mix with and change to
sleet and freezing rain for most of the area. Locations along and
south of US-50/I-66 likely end the event as rain as temperatures
warm through the morning. Areas along the Mason-Dixon are most
likely to remain all snow through the event, but that remains
uncertain given exact low track. The Tuesday morning commute could
be impacted for all areas in the Winter Weather Advisory. Updates to
the forecast are likely, so please remain weather aware for the
first widespread winter event of the season.

MDZ003>006-507-WVZ051>053-011345-
/O.NEW.KLWX.WW.Y.0022.251202T0800Z-251202T1800Z/
Washington-Frederick MD-Carroll-Northern Baltimore-Northwest
Harford-Morgan-Berkeley-Jefferson-
1238 AM EST Mon Dec 1 2025

...WINTER WEATHER ADVISORY IN EFFECT FROM 3 AM TO 1 PM EST TUESDAY...

* WHAT...Mixed precipitation expected. Total snow and sleet
  accumulations of 1 to 2 inches, with locally higher amounts
  upwards of 4 inches possible near the Mason-Dixon and higher
  elevations such as Parr`s Ridge. Ice accumulations around up to
  one tenth of an inch.

* WHERE...Portions of north central and northern Maryland and
  panhandle West Virginia.

* WHEN...From 3 AM to 1 PM EST Tuesday.

* IMPACTS...Plan on slippery road conditions. The hazardous
  conditions could impact the Tuesday morning commute.

* ADDITIONAL DETAILS...Precipitation is expected to overspread the
  area after after midnight tonight. Precipitation is expected to
  start as snow before mixing with sleet and freezing rain. Should
  precipitation stay all snow or snow for a longer period of time,
  locally higher snowfall
  amounts would be possible.

[yoda]

URGENT - WINTER WEATHER MESSAGE
National Weather Service Baltimore MD/Washington DC
1238 AM EST Mon Dec 1 2025

...FIRST WIDESPREAD WINTER EVENT OF THE SEASON...

.Precipitation is expected to overspread the area after midnight
tonight from southwest to northeast. While precipitation is likely
to start as snow areawide, it is expected to mix with and change to
sleet and freezing rain for most of the area. Locations along and
south of US-50/I-66 likely end the event as rain as temperatures
warm through the morning. Areas along the Mason-Dixon are most
likely to remain all snow through the event, but that remains
uncertain given exact low track. The Tuesday morning commute could
be impacted for all areas in the Winter Weather Advisory. Updates to
the forecast are likely, so please remain weather aware for the
first widespread winter event of the season.

MDZ501-502-509-510-WVZ501-503-504-011345-
/O.NEW.KLWX.WW.Y.0022.251202T0600Z-251202T1800Z/
Extreme Western Allegany-Central and Eastern Allegany-Western
Garrett-Eastern Garrett-Western Grant-Western Mineral-Eastern
Mineral-
1238 AM EST Mon Dec 1 2025

...WINTER WEATHER ADVISORY IN EFFECT FROM 1 AM TO 1 PM EST TUESDAY...

* WHAT...Mixed precipitation expected. Total snow and sleet
  accumulations between 1 and 3 inches with locally up to 4 inches
  near the Mason-Dixon. Ice accumulations up to one tenth of an inch.


* WHERE...Portions of western Maryland and eastern West Virginia.

* WHEN...From 1 AM to 1 PM EST Tuesday.

* IMPACTS...Plan on slippery road conditions. The hazardous
  conditions will likely impact the Tuesday morning commute.

* ADDITIONAL DETAILS...Precipitation is expected to overspread the
  area after after midnight tonight. Precipitation is expected to
  start as snow before mixing with sleet and freezing rain. Should
  precipitation stay all snow or snow for a longer period of time,
  locally higher snowfall amounts would be possible. Additional
  upslope snow showers are expected Tuesday afternoon for locations
  west of the Allegheny Front which could produce a coating to inch
  or so of additional accumulation.

[yoda]

URGENT - WINTER WEATHER MESSAGE
National Weather Service Baltimore MD/Washington DC
1238 AM EST Mon Dec 1 2025

...FIRST WIDESPREAD WINTER EVENT OF THE SEASON...

.Precipitation is expected to overspread the area after midnight
tonight from southwest to northeast. While precipitation is likely
to start as snow areawide, it is expected to mix with and change to
sleet and freezing rain for most of the area. Locations along and
south of US-50/I-66 likely end the event as rain as temperatures
warm through the morning. Areas along the Mason-Dixon are most
likely to remain all snow through the event, but that remains
uncertain given exact low track. The Tuesday morning commute could
be impacted for all areas in the Winter Weather Advisory. Updates to
the forecast are likely, so please remain weather aware for the
first widespread winter event of the season.

VAZ025>031-036>040-050-051-501-503>505-507-508-WVZ050-055-502-505-
506-011345-
/O.NEW.KLWX.WW.Y.0022.251202T0600Z-251202T1700Z/
Augusta-Rockingham-Shenandoah-Frederick VA-Page-Warren-Clarke-
Nelson-Albemarle-Greene-Madison-Rappahannock-Orange-Culpeper-
Northern Fauquier-Western Highland-Eastern Highland-Western
Loudoun-Northern Virginia Blue Ridge-Central Virginia Blue Ridge-
Hampshire-Hardy-Eastern Grant-Western Pendleton-Eastern Pendleton-
1238 AM EST Mon Dec 1 2025

...WINTER WEATHER ADVISORY IN EFFECT FROM 1 AM TO NOON EST TUESDAY...

* WHAT...Mixed precipitation expected, with a majority of the
  precipitation expected in the form of freezing rain. Total snow
  and sleet accumulations up to one inch and ice accumulations
  around one tenth of an inch, with upwards of two tenths of an inch
  possible on the higher ridges.

* WHERE...Portions of central, northern, northwest, and western
  Virginia and eastern West Virginia.

* WHEN...From 1 AM to noon EST Tuesday.

* IMPACTS...Plan on slippery road conditions. The hazardous
  conditions could impact the Tuesday morning commute.

* ADDITIONAL DETAILS...Precipitation is expected to overspread the
  area after after
  midnight tonight. Precipitation is expected to start briefly as snow
  before mixing with and changing over to sleet and freezing rain.

 

[TSSN+]

6z hrrr and Nam look decent for north crew. Nam finally folded. 
 

 

[Weather Will]

WB 6Z GFS

[Weather Will]

WB 6Z HRRR

[mitchnick]

28 minutes ago, Weather Will said:

WB 6Z HRRR

Interesting how the basic signature of the precip shield is very similar to the Gfs, but the Gfs is just heavier.

[Terpeast]

I would love for that HRRR to verify