Jump to content
  • Member Statistics

    17,599
    Total Members
    7,904
    Most Online
    ArlyDude
    Newest Member
    ArlyDude
    Joined

Central PA - February 2017


MAG5035

Recommended Posts

25 minutes ago, pasnownut said:

And THATS the CTP we all know and .........

well we know em ;)

I'm just goint to reread the forecast discussion a few times...it'll boost my spirits.

Nut

 

Well the "potential for this much" map is quite decent haha. That particular one is the 90th percentile map, or in other words a 10% chance of at least x amount of snow falling. The other one "expect at least this much is the 10 percentile map, meaning there is a 90% certainty of getting at least x amount of snow.  It def displays the uncertainty remaining. A difference of a degree or two might mean the difference between mainly rain and a snow bomb for a healthy portion of C-PA.. specifically in the central counties below UNV. Not sure if their Most Likely map is a straight 50/50 blend but in general they are slightly less bullish than HPC snow guidance at these percentiles. It's a pretty good call for now, but I do think the higher Laurel's areas are underdone in their most likely map. 

SnowAmt90Prcntl.png


 
Link to comment
Share on other sites

  • Replies 1.7k
  • Created
  • Last Reply
16 minutes ago, Atomixwx said:

Considering MDT has about 3 inches on the aggregate, a ground-whitener is a winner.

It's 1.5" I thought? 

I mean the snow total, not what you're carrying. ;)

But I think Clearfield gets more love tomorrow, I doubt down here we see any accumulation. I never trust cold air to push warmth out of the valley that's been in place for days.

Link to comment
Share on other sites

18z hires NAM is showing quite a difference depending on the snowfall technique used.

On the one hand, the e-Wall snowfall total shows 4+ across the whole area 

Screen Shot 2017-01-22 at 5.22.19 PM.png'

 

But if you use the Kuchera technique which incorporates the temperature of the entire column, you get something more like:

Screen Shot 2017-01-22 at 5.25.03 PM.png

So yeah, this is a very marginal setup.

Link to comment
Share on other sites

32 minutes ago, Jmister said:

18z hires NAM is showing quite a difference depending on the snowfall technique used.

On the one hand, the e-Wall snowfall total shows 4+ across the whole area 

Screen Shot 2017-01-22 at 5.22.19 PM.png'

 

But if you use the Kuchera technique which incorporates the temperature of the entire column, you get something more like:

Screen Shot 2017-01-22 at 5.25.03 PM.png

So yeah, this is a very marginal setup.

Wow.  Didnt check the Kuchera.  That is quite a difference.

 

I vote for panel no. 1 please.

 

Nut

 

Link to comment
Share on other sites

6 minutes ago, Wmsptwx said:

Probably see watches go to advisories shortly.

Based on what exactly? I mean, sure... if the 00z runs come in north and warm then yes... but as of right now there are some models that show warning level snows for those in the watch area like the 12z ECMWF.

Link to comment
Share on other sites

12 minutes ago, Blizz said:

00z NAM gives the State College area close to a foot of snow.

EDIT: Using 10:1 ratios...

Most likely won't be that.

We're closing in on four feet of clown map snow on the season!!

It'll be fun tracking tomorrow but I'll be pretty shocked if the grass ends up covered.

 

Link to comment
Share on other sites

7 minutes ago, Blizz said:

00z NAM gives the State College area close to a foot of snow.

EDIT: Using 10:1 ratios...

Most likely won't be that.

18 and 0z NAM even let the LSV play along. True NC gets a shellackin. 

Anxious to see if we can pull another good set if 0z's.  

Heck the long range after midweek warmup looks like it might be winter for a while.  We may actually be able to put the toasters back on the shelf and talk winter. God I hope so. 

Nut  

 

Link to comment
Share on other sites

CTP hedging a little bit in their point forecast now though... calling for all snow from 1PM - 1AM. Total accumulation of ~1 inch :lol:

Surprised to see the 30 MPH gusts though! Didn't realize the winds would be that high this far inland. Could make for some fun times if the snow does happen...

Monday
Rain before 1pm, then snow. High near 38. Breezy, with an east wind 14 to 20 mph, with gusts as high as 30 mph. Chance of precipitation is 100%. New snow accumulation of less than a half inch possible.
Monday Night
Snow before 1am, then rain and snow showers likely. Low around 31. Northeast wind 9 to 15 mph, with gusts as high as 20 mph. Chance of precipitation is 90%. New snow accumulation of around an inch possible.
Link to comment
Share on other sites

4 hours ago, Jmister said:

18z hires NAM is showing quite a difference depending on the snowfall technique used.

On the one hand, the e-Wall snowfall total shows 4+ across the whole area 

 

 

But if you use the Kuchera technique which incorporates the temperature of the entire column, you get something more like:

 

So yeah, this is a very marginal setup.

Yup I'll take the NAM using the happy hour method over Kuchera haha. The comparison certainly illustrates the fine line we have with this. I definitely think Kuchera is underestimating North Central PA. NAM p-types have a lot of sleet in NY State.The rest of the central below I-80 could depend. On the contrary, that particular E-wall NAM snowfall map usually overestimates. I was trying to find some Kuchera methodologies on how it calculates ratios and the best I found was this. I'd be curious to hear from anyone that has any more elaboration on how that's calculated. 

Where the model forecasts snow: 1) Find the maximum temperature in the lowest 500 hPa in degrees K (MaxT). 2) If MaxT is greater than 271.16K, then the liquid equivalent ratio (RAT) is 12.0 + 2.0*(271.16-MaxT). 3) If MaxT is less than 271.16K, then the liquid equivalent ratio (RAT) is 12.0 + (271.16-MaxT)

With this setup the warmest temps reside under 925mb near the surface and models really haven't had any widespread surface temps below freezing anywhere, mainly ranging in the 32-35 range (likely a lot of 33-34s). You figure you plug 1 or 2ºC (274.16 or 275.16K) into that equation and that comes out to a 4 or 6:1 ratio. Also a part of that statement, the model has to be showing a straight snow p-type. The 4km NAM def didn't have the widespread snow p-type that the 12km did either...which was a probably a big factor in it. At any rate looks like the new 0z NAM is better for snow in C-PA 

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

  • Recently Browsing   0 members

    • No registered users viewing this page.

×
×
  • Create New...