Pittsburgh PA ❄️ Winter 2017-2018

[RitualOfTheTrout]

4 minutes ago, north pgh said:

I am assuming that the reason behind not too many posts in this thread means that everyone else (including me) is waiting for the dreaded.......

Yeah, I'm having a hard time buying into anything 6+ inches right now, and that's my benchmark given the time of year for a good storm. Temperatures are so marginal, but man, when is the last time you saw a temperature disbursement like this:

[IrishWxBurgher]

I would like one snowstorm where things are consistent and we'll all have a good thump.  But instead, we get another storm where we're treading that fine line.

Latest GFS seems to indicate that some of us may luck out, but the warmth and timing, among other things, seems to make it likely some of us will fall short...  What are some key factors to watch for over the next 24 hours to see if we'll get fringed versus luck out with the 6+ some models are showing? 

[Mailman]

[jwilson]

34 minutes ago, IrishWxBurgher said:

I would like one snowstorm where things are consistent and we'll all have a good thump.  But instead, we get another storm where we're treading that fine line.

Latest GFS seems to indicate that some of us may luck out, but the warmth and timing, among other things, seems to make it likely some of us will fall short...  What are some key factors to watch for over the next 24 hours to see if we'll get fringed versus luck out with the 6+ some models are showing? 

This storm has been notoriously difficult to nail down.  Each run has jumped from one solution to another.  It looks like there will be a somewhat narrow band of "jackpot" accumulations running through Ohio and Western PA. 

Wave 1 looks like a miss for most of us in that it won't put down much snow.  Wave 2 begins once the coastal takes over.  It all comes down to mesoscale features.  Where will the precip shield setup?  How big will it be?  Who gets subsidence vs. convergence?

12Z 3K NAM moves the best bit north into Butler and Beaver county, and a fairly narrow area at that.  The 12K NAM gives a wider swath and is considerably more wet, but probably overdone (as is typical with the NAM).  Both are north of where 6Z was.  So how far north will the best snow bands setup once the coastal takes over?  That's the main question.

Either way, it looks like someone is going to get screwed.

[MikeB_01]

Just now, Mailman said:

 

 

lol

[IrishWxBurgher]

The NWS 10% max map shows that the potential is there, but I wonder why the totals are so low on the main forecast map?  Less than an inch of snow? Really?

Every model seems to show at least 2 inches.  Are the temperatures the main issue?  I'm just an amateur, so I'm trying to figure out what to look at/watch for that the NWS is seeing.

[cwc]

Models do not take sun angle and ground temps into account.  The numbers you see on the models are garbage at this point in the season.

In addition, some of our "snow" will be lost to rain and sleet.

And temps are marginal

[Burghblizz]

For fun....I’d even say the “high end amount” is higher, but there is so much working against it

[SteelCity08]

Not buying into anything but I will say that as long as precip is steady and heavy enough the sun angle gets negated for the most part. The second it lightens up or stops though it's a killer lol. Saw snow accumulate last week very quick with no issue, then I watched it melt away. All in a matter of 10 minutes. 

[JPOracle]

I have to say the one snowmap where its less then an inch for most of the area is absurd at this point, an 2-4 inch snow is minimal at this point with potential for way more with NAM showing over an foot for most of Western PA.  An winter storm watch should be out if the 18z run shows the same again

[CoraopolisWx]

Mabey this storm ends up being the March 1962 type setup that was talked about earlier this month.

A well place inverted trough usually gives us a chance to overperform.

[Mailman]

Euro looks decent for the weekend.  lol.

[DanTheMan]

Man its going to be depressing on Wednesday when my sister is sending me white-out pictures from NoVa while I struggle for an inch or two in Mrgntown

[RitualOfTheTrout]

11 minutes ago, Mailman said:

Euro looks decent for the weekend.  lol.

If this keeps up we will have a very short "off season" before tracking picks back up again lol #May Blizzard! Still would have rather had this March pattern in Feb but beggars can't be choosers.

[meatwad]

Winter Weather Advisory

URGENT - WINTER WEATHER MESSAGE
National Weather Service Pittsburgh PA
319 PM EDT Mon Mar 19 2018

OHZ039>041-048>050-PAZ013-014-020>023-073-074-WVZ001-200330-
/O.NEW.KPBZ.WW.Y.0018.180321T0000Z-180322T0000Z/
Tuscarawas-Carroll-Columbiana-Coshocton-Harrison-Jefferson-
Lawrence-Butler-Beaver-Allegheny-Armstrong-Indiana-Westmoreland-
Westmoreland Ridges-Hancock-
Including the cities of New Philadelphia, Dover, Carrollton,
Malvern, East Liverpool, Salem, Columbiana, Coshocton, Cadiz,
Steubenville, New Castle, Ellwood City, Butler, Aliquippa,
Beaver Falls, Ambridge, Monaca, Pittsburgh Metro Area,
Kittanning, Ford City, Indiana, Murrysville, Greensburg,
New Kensington, Ligonier, Donegal, and Weirton
319 PM EDT Mon Mar 19 2018

...WINTER WEATHER ADVISORY IN EFFECT FROM 8 PM TUESDAY TO 8 PM
EDT WEDNESDAY...

* WHAT...Snow expected. Total snow accumulations of 2 to 4 inches
  are expected.

* WHERE...Portions of southwest, west central and western
  Pennsylvania, east central Ohio and northern West Virginia.

* WHEN...From 8 PM Tuesday to 8 PM EDT Wednesday. Most of the
  accumulation will occur Tuesday night.

* ADDITIONAL DETAILS...Plan on slippery road conditions,
  including during the morning commute on Wednesday. Be prepared
  for reduced visibilities at times.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Weather Advisory for snow means periods of snow will
cause primarily travel difficulties. Be prepared for snow covered
roads and limited visibilities, and use caution while driving.
Please report snow or ice by calling 412-262-1988, posting to the
NWS Pittsburgh Facebook page, or using Twitter @NWSPittsburgh

&&

$$

[Mailman]

OHZ057>059-068-069-PAZ029-031-075-WVZ002>004-012-021-509-200330-
/O.NEW.KPBZ.WW.Y.0018.180321T0000Z-180322T0000Z/
Muskingum-Guernsey-Belmont-Noble-Monroe-Washington-Greene-Fayette-
Brooke-Ohio-Marshall-Wetzel-Marion-Monongalia-
Including the cities of Zanesville, Cambridge, Martins Ferry,
St. Clairsville, Caldwell, Woodsfield, Washington, Canonsburg,
Waynesburg, Uniontown, Follansbee, Wellsburg, Wheeling,
Moundsville, New Martinsville, Fairmont, and Morgantown
319 PM EDT Mon Mar 19 2018

...WINTER WEATHER ADVISORY IN EFFECT FROM 8 PM TUESDAY TO 8 PM
EDT WEDNESDAY...

* WHAT...Snow expected. Total snow accumulations of 2 to 4
  inches are expected.

* WHERE...Portions of southwest Pennsylvania, east central Ohio
  and northern and northern panhandle of West Virginia.

* WHEN...From 8 PM Tuesday to 8 PM EDT Wednesday. Most of the
  accumulation will occur Tuesday night.

* ADDITIONAL DETAILS...Plan on slippery road conditions,
  including during the morning commute on Wednesday. Be prepared
  for reduced visibilities at times.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Weather Advisory for snow means periods of snow will
cause primarily travel difficulties. Be prepared for snow covered
roads and limited visibilities, and use caution while driving.
Please report snow or ice by calling 412-262-1988, posting to the
NWS Pittsburgh Facebook page, or using Twitter @NWSPittsburgh

[KPITSnow]

10 minutes ago, Mailman said:

OHZ057>059-068-069-PAZ029-031-075-WVZ002>004-012-021-509-200330-
/O.NEW.KPBZ.WW.Y.0018.180321T0000Z-180322T0000Z/
Muskingum-Guernsey-Belmont-Noble-Monroe-Washington-Greene-Fayette-
Brooke-Ohio-Marshall-Wetzel-Marion-Monongalia-
Including the cities of Zanesville, Cambridge, Martins Ferry,
St. Clairsville, Caldwell, Woodsfield, Washington, Canonsburg,
Waynesburg, Uniontown, Follansbee, Wellsburg, Wheeling,
Moundsville, New Martinsville, Fairmont, and Morgantown
319 PM EDT Mon Mar 19 2018

...WINTER WEATHER ADVISORY IN EFFECT FROM 8 PM TUESDAY TO 8 PM
EDT WEDNESDAY...

* WHAT...Snow expected. Total snow accumulations of 2 to 4
  inches are expected.

* WHERE...Portions of southwest Pennsylvania, east central Ohio
  and northern and northern panhandle of West Virginia.

* WHEN...From 8 PM Tuesday to 8 PM EDT Wednesday. Most of the
  accumulation will occur Tuesday night.

* ADDITIONAL DETAILS...Plan on slippery road conditions,
  including during the morning commute on Wednesday. Be prepared
  for reduced visibilities at times.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Weather Advisory for snow means periods of snow will
cause primarily travel difficulties. Be prepared for snow covered
roads and limited visibilities, and use caution while driving.
Please report snow or ice by calling 412-262-1988, posting to the
NWS Pittsburgh Facebook page, or using Twitter @NWSPittsburgh

Why put out that snow map then issue this?

[cwc]

10 minutes ago, KPITSnow said:

Why put out that snow map then issue this?

Doesn't include AGC.  It is in line with the snow map

 

edit:  didn't see the first one.

[north pgh]

5 minutes ago, KPITSnow said:

Why put out that snow map then issue this?

I am guessing that snow map is old from this morning and they just put out the WWA in the last half hour. It is pretty much what I expected. It looks like they are not expecting any accumulation during the day tomorrow because of the daylight sun angle and temperature. I kind of agree however if we get some good rates tomorrow afternoon you can add that to the totals. Maybe some grassy accumulation during the day. 

This is a very unpredictable storm based on deformation bands and precip rates. I remember a storm like this in March in the mid to late 80's when I lived in the North Hills and worked in Bethel Park. Things were turned upside down as I got about 2 inches at home and drove into heavy wet snow in the south Hills totaling about 8 inches. It was very isolated and I am guessing that will happen with this storm with some areas getting 2 inches and others seeing much more. It will definitely be a nowcast storm. It will be interesting to see all of the different local reports the next several days based on what location you are at. It should be fun ..(All assuming we don't bust...which we all know is still possible......lol

[cwc]

Reading the discussions from various NWS locales, it seems like they are focused on ridges and elevation and south, but possible for some banding to set up, and a nighttime event, hence the WWA.  

 

[SteelCity08]

Of course we get this storm in spring and not Dec-Feb lol. Oh well, hoping for surprises. The east coast got plenty of snow during the day a week ago so whho knows. 

[Mailman]

Updated map:

[Burghblizz]

Tried to post the “high end” potential but the link kept showing the old one. It’s now 11-12”.

Just for fun, but recognizing the potential 

[CoraopolisWx]

My weenie brain might be way off, but i can't remember the NWS issuing a WWA 30 hrs in advance.

So my theory is that KPIT wants to upgrade to a WSWarning eventually, but will stay with the WWA until the 00z model data is complete. This provides wiggle room in case the models start trending the other way.

[north pgh]

1 minute ago, CoraopolisWx said:

My weenie brain might be way off, but i can't remember the NWS issuing a WWA 30 hrs in advance.

So my theory is that KPIT wants to upgrade to a WSWarning eventually, but will stay with the WWA until the 00z model data is complete. This provides wiggle room in case the models start trending the other way.

I agree. I think at worst we get a 2-4 inch heavy wet snow storm. If models keep over-performing we will see totals go up as early as late tonight or tomorrow morning. 

[jwilson]

3K went even further north.  Trend can't be denied, I guess.  Looks real good for Pittsburgh.  I just about consider that the death knell for us in the south, though.

I'd guess the best snowfall will remain from Washington, PA on north.

[Mailman]

Latest disco:

.SHORT TERM /TUESDAY NIGHT THROUGH WEDNESDAY NIGHT/...
...Heavy Wet Snow in the Allegheny Front Tuesday night into 
Wednesday...

Quiet a turn around in the forecast with the 12Z operational
runs with respect to pending snowfall late tonight into
Wednesday then Tuesday night into Wednesday. NAM went bonkers
with QPF and thus snowfall for much of the region, however given
its March and daytime accumulation is very tough, did not buy
and cut about 50 percent off its snow forecast. This allows us 
wiggle room if the 00Z runs flop back to a low QPF / low snow 
amount forecast. Of course, it would not be surprising to see a 
few counties get upgraded to a winter storm warning if a band 
sets up. 

A two pronged attack with one surface low passing to our south
late tonight. There will be a warm layer aloft that could lead
to a short period of a wintry mix before switching to a rain
snow mix as the pocket cools. Any accumulation of ice should be
confined to parts of eastern Tucker and Garrett county before
switching over. A prolong period of cold advection with 
northeast to easterly winds will lead to wet snow over the 
lowlands. Believe omega fields are overdone due to warm 
advection, which has yielded a lower QPF than most models. One 
thing we don't have to worry about is being dry slotted since 
mid level low will pass over the central Appalachians. 

The time frame for heaviest snowfall will be Tuesday night into
Wednesday especially for the higher elevations. The ensembles
have a -2 to -3 standard deviation of the U wind component 
which is decent /not great/ for significant snowfall. Given it 
will be at night, and snowfall rates can overcome a warm 
ground, expect most of the accumulation during this time frame 
over the lower elevations. During the day Wednesday snowfall 
will persist over the higher elevations given colder surface 
temperatures, snow covered ground, and 1-2" per hour snow 
rates. BUFR soundings support wet snow given a near isothermal 
profile in the sounding. Overall storm total snow amounts are 
close to the CIPS analog for this event which puts double digit 
numbers in the mountains and a 2-4 range over lower elevations. 

Headlines:
Confidence is high enough in 8" in 24 hours of wet snow for the
higher terrain to upgrade the winter storm watch to a winter
storm warning. In addition, since this will be an elevation
dependent event, included the ridges of eastern Fayette county
and higher elevation of eastern Mon and western Preston county.

Elsewhere added a winer weather advisory in collaboration with 
adjacent offices. We reside on the lower side of the numerical 
guidance for snowfall, basically between NAM and GFS, which 
aligns more with ensembles. The warning was a little tricky 
since there will be a break in the snow Tuesday afternoon and 
evening before the second strong wave crosses producing a bulk 
of the snowfall and tried to capture that in the text ontop of
the gridded forecast. 

[Rd9108]

6 hours ago, north pgh said:

I am assuming that the reason behind not too many posts in this thread means that everyone else (including me) is waiting for the dreaded.......

After seeing the nam I'm waiting for it. It's a win win. If it snows a a lot I get my storm but we have to shovel it at the academy. If it misses then it's less shoveling. 

[SteelCity08]

55 minutes ago, CoraopolisWx said:

My weenie brain might be way off, but i can't remember the NWS issuing a WWA 30 hrs in advance.

So my theory is that KPIT wants to upgrade to a WSWarning eventually, but will stay with the WWA until the 00z model data is complete. This provides wiggle room in case the models start trending the other way.

Good call

[PghPirates27]

I’m getting pumped up !!!