January 18th Event

[AmericanWxFreak]

6 minutes ago, BTRWx's Thanks Giving said:

Why do so many areas have a winter weather advisory for an inch of slush when there's no rush hour?

So just because there is no rush hour, the people that still have to work and be out tomorrow morning shouldn't be advised that travel will certainly become treacherous? When it snows tomorrow morning it will not be slush - it will stick and freeze to the roads

[BTRWx's Thanks Giving]

6 minutes ago, AmericanWxFreak said:

So just because there is no rush hour, the people that still have to work and be out tomorrow morning shouldn't be advised that travel will certainly become treacherous? When it snows tomorrow morning it will not be slush - it will stick and freeze to the roads

I thought there was specific criteria that has to be met.

eta: https://www.weather.gov/lwx/WarningsDefined#Winter Weather Advisory "

Winter Weather Advisory

A Winter Weather Advisory will be issued for any amount of freezing rain, or when 2 to 4 inches of snow (alone or in combination with sleet and freezing rain), is expected to cause a significant inconvenience, but not serious enough to warrant a warning.

If the event is expected to impact the Baltimore/Washington metro areas during rush hours (4-9 am or 2-7 pm on weekdays) forecasted snow totals of one inch will necessitate the issuance of a winter weather advisory. The snow/sleet criteria for a Winter Weather Advisory for the five westernmost counties (Allegany, Mineral, Grant, Pendleton, and Highland) is higher (3-5 inches).

"

[yoda]

1 minute ago, BTRWx's Thanks Giving said:

I thought there was specific criteria that has to be met.

eta: https://www.weather.gov/lwx/WarningsDefined#Winter Weather Advisory "

Winter Weather Advisory

A Winter Weather Advisory will be issued for any amount of freezing rain, or when 2 to 4 inches of snow (alone or in combination with sleet and freezing rain), is expected to cause a significant inconvenience, but not serious enough to warrant a warning.

If the event is expected to impact the Baltimore/Washington metro areas during rush hours (4-9 am or 2-7 pm on weekdays) forecasted snow totals of one inch will necessitate the issuance of a winter weather advisory. The snow/sleet criteria for a Winter Weather Advisory for the five westernmost counties (Allegany, Mineral, Grant, Pendleton, and Highland) is higher (3-5 inches).

"

Thanks and have a good day  

[mappy]

never thought i'd see the day where someone complains about an advisory being issued. usually its everyone whining about when they get issued and how the snow depends on it. 

this place. 

[yoda]

1 minute ago, mappy said:

never thought i'd see the day where someone complains about an advisory being issued. usually its everyone whining about when they get issued and how the snow depends on it. 

this place. 

Its the same person complaining about the advisory that posted the snow depth maps 

[Interstate]

NAM is going to make a couple more people happy.  At least they will see some snow.

[mappy]

4 minutes ago, yoda said:

Its the same person complaining about the advisory that posted the snow depth maps 

i know who it is yoda, i can read. 

[Chase]

1 minute ago, mappy said:

i know who it is yoda, i can read. 

[WxUSAF]

NAM 3k soundings are much more interesting on the 18z run vs 12z. 700mb frontogen is better over MD and there is strong vertical motion in the dendrite growth zone near 500mb. Warm layer near 850 still near freezing though. Big rimed conglomerates?

[osfan24]

6 minutes ago, Interstate said:

NAM is going to make a couple more people happy.  At least they will see some snow.

That initial wave seems very fast. Maybe an hour of snow for most. 3K still looks like a virtual non-event for almost all but maybe the northern tier. Of course, any little bit of ice can cause major problems on the roads.

[Weather Will]

18Z 3K NAM WB Winter Precip

[snowfan]

9 minutes ago, WxUSAF said:

NAM 3k soundings are much more interesting on the 18z run vs 12z. 700mb frontogen is better over MD and there is strong vertical motion in the dendrite growth zone near 500mb. Warm layer near 850 still near freezing though. Big rimed conglomerates?

Still wouldnt be surprised if folks are pinging soon after initial flakes.

[Baltimorewx]

I think the key is going to be that initial band in the morning...hopefully its a solid 2-3 hour period of snow and drops a quick 1" or 2"..but on the other hand, my fear is that the air will be pretty dry and itll just be pixie dust

[snowfan]

Eric Horst's map seems realistic for the area. An inch (maybe 2) along the MD line then pingers.

[mappy]

2 minutes ago, snowfan said:

Eric Horst's map seems realistic for the area. An inch (maybe 2) along the MD line then pingers.

Cranky has 2-4" for the same areas. I think its possible to get up to 4" but it would be snow/sleet combined. Unless the NAM is right, then we are lucky to see an inch or so. 

[snowfan]

2 minutes ago, mappy said:

Cranky has 2-4" for the same areas. I think its possible to get up to 4" but it would be snow/sleet combined. Unless the NAM is right, then we are lucky to see an inch or so. 

I'll be in stewartstown tmrw, so hoping that's the case.

[mappy]

1 minute ago, snowfan said:

I'll be in stewartstown tmrw, so hoping that's the case.

youll be fine. will probably do better than me.

[George BM]

2 hours ago, BTRWx's Thanks Giving said:

I thought there was specific criteria that has to be met.

eta: https://www.weather.gov/lwx/WarningsDefined#Winter Weather Advisory "

Winter Weather Advisory

A Winter Weather Advisory will be issued for any amount of freezing rain, or when 2 to 4 inches of snow (alone or in combination with sleet and freezing rain), is expected to cause a significant inconvenience, but not serious enough to warrant a warning.

If the event is expected to impact the Baltimore/Washington metro areas during rush hours (4-9 am or 2-7 pm on weekdays) forecasted snow totals of one inch will necessitate the issuance of a winter weather advisory. The snow/sleet criteria for a Winter Weather Advisory for the five westernmost counties (Allegany, Mineral, Grant, Pendleton, and Highland) is higher (3-5 inches).

"

There is the potential for some ice accretion. 

URGENT - WINTER WEATHER MESSAGE
National Weather Service Baltimore MD/Washington DC
133 PM EST Fri Jan 17 2020

MDZ503-504-VAZ028-030-031-052-053-501-502-505-506-WVZ052-053-
180245-
/O.NEW.KLWX.WW.Y.0003.200118T1200Z-200119T0000Z/
Northwest Montgomery-Central and Southeast Montgomery-
Frederick VA-Warren-Clarke-Prince William/Manassas/Manassas Park-
Fairfax-Northern Fauquier-Southern Fauquier-Western Loudoun-
Eastern Loudoun-Berkeley-Jefferson-
133 PM EST Fri Jan 17 2020

...WINTER WEATHER ADVISORY IN EFFECT FROM 7 AM TO 7 PM EST
SATURDAY...

* WHAT...Snow, sleet and freezing rain expected. Total snow and
  sleet accumulations of up to one inch and ice accumulations of
  up to one tenth of an inch.

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

* WHEN...From 7 AM to 7 PM EST Saturday. Precipitation will begin
  as snow before transitioning to sleet and freezing rain.
  Precipitation will change to rain late in the day.

* IMPACTS...Plan on slippery road conditions.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Slow down and use caution while traveling.

When venturing outside, watch your first few steps taken on
steps, sidewalks, and driveways, which could be icy and slippery,
increasing your risk of a fall and injury.

&&

$$

 

Hope that helps. 

[Baltimorewx]

Its already a win for me though, Baltimore County rec and parks cancelled all activities for tomorrow so no work for me

[BTRWx's Thanks Giving]

It's not all snow in the A.M.

[Scraff]

I heard we had a winter event tomorrow. I stocked up. Anyone want to come over? Having a Fresca party...

[Baltimorewx]

1 minute ago, Scraff said:

I heard we had a winter event tomorrow. I stocked up. Anyone want to come over? Having a Fresca party...

Nice...Let me have that Devils Milk

[BristowWx]

5 minutes ago, Scraff said:

I heard we had a winter event tomorrow. I stocked up. Anyone want to come over? Having a Fresca party...

Hate to see what happens to the lone can of Fresca when the door closes.  I see a prison pounding in its future. 

[high risk]

23 minutes ago, BTRWx's Thanks Giving said:

It's not all snow in the A.M.

 

          This is a good catch, but the idea of that initial band having some sleet in it is an outlier solution, and the associated forecast soundings have a warm layer that is just barely above freezing.    Something to watch for in the evening runs, though.

[losetoa6]

Hrrr tomorrow morning at 12z . On DC's nw lawn .

[SnowGolfBro]

12 minutes ago, losetoa6 said:

Hrrr tomorrow morning at 12z . On DC's nw lawn .

Now if we can just get that same look for 4-6 consecutive hours tomorrow morning we will be in business lol!

[Scraff]

So all the fuss for a Saturday snow shower. OMG.  

[mappy]

Gfs a little drier, at least up my way

[osfan24]

4 minutes ago, Scraff said:

So all the fuss for a Saturday snow shower. OMG.  

This is the way it has been trending for days, unfortunately. I'd feel a lot better about it if the long range was still looking as promising as it was when this event started trending south, but we've even lost that now. I'm just hoping that initial band gives me a good hour or so of snow. Otherwise, I'm not expecting to see much other than a little sleet and a little rain.

[Weather Will]

WB 18Z GFS Winter Precip maps.