Central PA - Winter 2021/2022

[CarlislePaWx]

17.1 / 6 with solid overcast and virtually no wind.

[whiteout]

This is just one of those storms you can’t believe. Sitting at 14° in Newville at noon. And then in 8 to 12 hours I’m expecting to be changed over to rain unless I get into the dry slot. Just seems like it’s not possible.


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[CarlislePaWx]

Also, my current wet bulb is 15.  Temp now 17.6.  That combination is not going to produce much cooling when precip begins despite the dew point hovering around 6 above.

[Bubbler86]

Just watched a video, from 7 years ago, where Ryan Maue explains how the Euro snow maps are done on Wxbell.   He did not broach GFS.  He said Euro output includes sleet AND Frz and he has an algorithm that attempts to back out the liquid equivalent.  So this may explain why Wxbell maps are so different from TT and Pivotal re: each uses their own method.   Here is TT for the 12Z GFS and its definitely lower in some areas despite including sleet.  Important to know for model PBP.   TT also uses the "SLR " which is explained by Ryan also below.

 

Today's 12Z GFS on TT

 

 

 

 

 

 

 

 

[Ruin]

I think this is a win they say the highest temperature today is only supposed to be 29 now before it was 34 for the daily so maybe we hold onto more snow before the ice? Last forecast st 34 had mdt changing to just rain at 930isj pm

 

[mahantango#1]

Temp 20 dp 12 @1230pm

[Cashtown_Coop]

someone is going to bust.   

[Blizzard of 93]

8 minutes ago, Bubbler86 said:

Just watched a video, from 7 years ago, where Ryan Maue explains how the Euro snow maps are done on Wxbell.   He did not broach GFS.  He said Euro output includes sleet AND Frz and he has an algorithm that attempts to back out the liquid equivalent.  So this may explain why Wxbell maps are so different from TT and Pivotal re: each uses their own method.   Here is TT for the 12Z GFS and its definitely lower in some areas despite including sleet.  Important to know for model PBP.   TT also uses the "SLR " which is explained by Ryan also below.

 

Today's 12Z GFS on TT

 

 

 

 

 

 

 

 

They changed it after that….

Weatherbell maps are legit and used by good posters on the forums from New England to the Mid Atlantic for years!

[MAG5035]

Current obs: Clouded up here. It’ll be interesting to watch the wind and barometer as this storm comes up tonight/tomorrow. Also still pretty dry here with the dew point below zero. 

 

 

[Cashtown_Coop]

Here’s LWX discussion on why raising their snow totals.   
 

I performed a cursory analysis of current conditions this morning and I found that temps are running a few degrees cooler than forecast with dewpoints in the single digits. Up stream observations in NC and southern VA suggests that snow is over performing. I have adjusted my snow ratios this morning to account for the well below freezing layer ahead of the precipitation which should allow for higher snow rates. Initial onset of precipitation is on track this morning and snow should fluffy to start before switching over to wet snow as the layer starts to warm and transitions over to a wintry mix for most areas along and east of I-81. I will continue to monitor current conditions to see if I need to up snow totals. It wouldn`t surprise me if we get higher snow totals further eastward than expected due to extremely cool air mass ahead of this system.

[Bubbler86]

1 minute ago, Blizzard of 93 said:

They changed it after that….

Weatherbell maps are legit and used by good posters on the forums from New England to the Mid Atlantic for years!

It's important to note that each site can be drastically different.  Two people could be looking at the same model and say 'What is he talking about' depending which site they are looking on.  Take York City today.  Wxbell has 4-4.5", TT has 3-4", and Pivotal has under 3".  

[Ruin]

Since everyone's doing observations 19 at Middletown cloudy light breeze 

[Superstorm]

Here’s LWX discussion on why raising their snow totals.   
 
I performed a cursory analysis of current conditions this morning and I found that temps are running a few degrees cooler than forecast with dewpoints in the single digits. Up stream observations in NC and southern VA suggests that snow is over performing. I have adjusted my snow ratios this morning to account for the well below freezing layer ahead of the precipitation which should allow for higher snow rates. Initial onset of precipitation is on track this morning and snow should fluffy to start before switching over to wet snow as the layer starts to warm and transitions over to a wintry mix for most areas along and east of I-81. I will continue to monitor current conditions to see if I need to up snow totals. It wouldn`t surprise me if we get higher snow totals further eastward than expected due to extremely cool air mass ahead of this system.

CTP not in agreement


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[Bubbler86]

2 minutes ago, Cashtown_Coop said:

Here’s LWX discussion on why raising their snow totals.   
 

I performed a cursory analysis of current conditions this morning and I found that temps are running a few degrees cooler than forecast with dewpoints in the single digits. Up stream observations in NC and southern VA suggests that snow is over performing. I have adjusted my snow ratios this morning to account for the well below freezing layer ahead of the precipitation which should allow for higher snow rates. Initial onset of precipitation is on track this morning and snow should fluffy to start before switching over to wet snow as the layer starts to warm and transitions over to a wintry mix for most areas along and east of I-81. I will continue to monitor current conditions to see if I need to up snow totals. It wouldn`t surprise me if we get higher snow totals further eastward than expected due to extremely cool air mass ahead of this system.

That was a big raise this way.  5-8"  LOL   No WSW. 

[Cashtown_Coop]

Just now, Bubbler86 said:

That was a big raise this way.  5-8"  LOL   No WSW. 

That’s the thing.   Another bump in amounts would turn the purples into pinks.   Wouldn’t surprise me to see warnings with afternoon update 

[Itstrainingtime]

19.4/6.2. Current pressure is 30.24" and slowly falling. 

[Bubbler86]

2 minutes ago, Cashtown_Coop said:

That’s the thing.   Another bump in amounts would turn the purples into pinks.   Wouldn’t surprise me to see warnings with afternoon update 

It would be a nowcasting call like LWX did.  Maybe under the premise that even though we lose 850's, there would be a lot more FRZ or Sleet than depicted on models. 

[Bubbler86]

21/9 here.  

[Itstrainingtime]

Reading conflicting reports from our friends to the south. One poster near Charlotte said the event outperformed guidance overnight, someone from Richmond said what was to be about 3-4 hours of snow lasted less than 1 hour before the flip. 

[Rd9108]

Hey guys hopefully you out east overperform. Maybe this storm has some magic up its sleeve. It's been a wild week regardless.

[Bubbler86]

Just now, Itstrainingtime said:

Reading conflicting reports from our friends to the south. One poster near Charlotte said the event outperformed guidance overnight, someone from Richmond said what was to be about 3-4 hours of snow lasted less than 1 hour before the flip. 

If you look at the current temps, its already above freezing (surface) at the Jersey Shore including some 40's.    Have to keep those easterly's away.  Maybe Richmond did not.   850 line looks like it is near Richmond right now. 

[Bubbler86]

Inland low is in Central TN right now per the SPC pressure maps. 

[kerplunk]

Anybody noticing the storm seems to be looking a bit ragged on national radar?

[MAG5035]

24 minutes ago, Bubbler86 said:

Just watched a video, from 7 years ago, where Ryan Maue explains how the Euro snow maps are done on Wxbell.   He did not broach GFS.  He said Euro output includes sleet AND Frz and he has an algorithm that attempts to back out the liquid equivalent.  So this may explain why Wxbell maps are so different from TT and Pivotal re: each uses their own method.   Here is TT for the 12Z GFS and its definitely lower in some areas despite including sleet.  Important to know for model PBP.   TT also uses the "SLR " which is explained by Ryan also below.

 

 

Today's 12Z GFS on TT

 

Yea being 7 years old that’s right when those WB maps/products first came out. Early on they were known to be really exaggerated on the edges where there was mix like the Tropical Tidbits maps are. TT literally says on their accumulation maps total snow/sleet. But WB changed their algorithms at some point and are a good bit better and I consider it fairly reliable. Gotta remember type of models make a difference too. A global model like the Euro/GFS aren’t going to see the finer details and sharpness with these transition areas.

But any rate on Weatherbell all p-types are separated now. if I want a sleet map, I can pull one up. They calculate accum for sleet on a 3:1 ratio for most of the models. Euro has been colder thermally and has had a more of a straight snow-rain transition with little in between in PA. Here’s the 3k NAM’s sleet map.

[Voyager]

21 minutes ago, Itstrainingtime said:

19.4/6.2. Current pressure is 30.24" and slowly falling. 

20.5/8.4

Pressure 30.24" (1024mb)

[Mount Joy Snowman]

22 minutes ago, Itstrainingtime said:

19.4/6.2. Current pressure is 30.24" and slowly falling. 

I’m already at 24 ugh. 

[Bubbler86]

20 minutes ago, MAG5035 said:

Yea being 7 years old that’s right when those WB maps/products first came out. Early on they were known to be really exaggerated on the edges where there was mix like the Tropical Tidbits maps are. TT literally says on their accumulation maps total snow/sleet. But WB changed their algorithms at some point and are a good bit better and I consider it fairly reliable. Gotta remember type of models make a difference too. A global model like the Euro/GFS aren’t going to see the finer details and sharpness with these transition areas.

But any rate on Weatherbell all p-types are separated now. if I want a sleet map, I can pull one up. They calculate accum for sleet on a 3:1 ratio for most of the models. Euro has been colder thermally and has had a more of a straight snow-rain transition with little in between in PA. Here’s the 3k NAM’s sleet map.

 

Bolded is an important point but not much to explain why Wxbell is higher than TT at the transition zone other than individual algorithms on each suite.  Wxbell is the only map I can find that has York City over 4" using 12Z GFS data.      Not saying Pivotal is right but Wxbell should not be higher than TT with the same data when the surface maps show sleet/frz will be part of the event. 

[Ruin]

6 minutes ago, Mount Joy Snowman said:

I’m already at 24 ugh. 

still 18-19 here 

[Voyager]

Trying to figure this out, not that it's super important, but I'm just wondering why the discrepancy...

Here is the forecast for overnight for Nesquehoning, five miles away from me, in Carbon County. They have a winter storm warning...

Tonight

Snow and sleet before 1am, then freezing rain between 1am and 2am, then rain after 2am. The rain could be heavy at times. Temperature rising to around 37 by 5am. Breezy, with an east wind 10 to 15 mph increasing to 15 to 20 mph after midnight. Winds could gust as high as 45 mph. Chance of precipitation is 100%. New ice accumulation of less than a 0.1 of an inch possible. New snow and sleet accumulation of 2 to 4 inches possible.

 

Then here is mine, and I only have an advisory...

 

Tonight

Snow, possibly mixed with freezing rain and sleet before 11pm, then snow and freezing rain between 11pm and midnight, then rain after midnight. The snow could be heavy at times. Temperature rising to around 38 by 4am. Breezy, with an east wind 10 to 15 mph increasing to 17 to 22 mph after midnight. Winds could gust as high as 30 mph. Chance of precipitation is 100%. Little or no ice accumulation expected. New snow and sleet accumulation of 3 to 7 inches possible.

 

Yet, the criteria for a winter storm warning is the same for both counties, as evidenced by the map below..

If the criteria is the same for both counties, and we're forecasted to get more snow, then why do we have an advisory and they have a warning? To me, it doesn't make sense...

[Ruin]

1 minute ago, Voyager said:

Trying to figure this out, not that it's super important, but I'm just wondering why the discrepancy...

Here is the forecast for overnight for Nesquehoning, five miles away from me, in Carbon County. They have a winter storm warning...

 

 

Then here is mine...

 

 

Yet, the criteria for a winter storm warning is the same for both counties, as evidenced by this map.

If the criteria is the same for both counties, and we're forecasted to get more snow, than why do we have an advisory and they have a warning. To me, it doesn't make sense...

they always be messing this up they once had me for a wsw for 4 inchs the last few years but not when we had a 7 inch snow so go figure.