CarlislePaWx

40.6 degrees with light rain continuing here. Rainfall so far = 0.60". That's about 33% of the storm total forecasted by the GFS last night. Snowpack is showing signs of taking on water with a little slushiness becoming visible. Still at 1.5" but probably for not many more hours.

Well look what I woke up to a little earlier. My prediction of a WWA came true. That was the only prediction I made. Nothing about precip types, etc. No one has posted some surface temp maps for overnight yet. Last night the 32 line was supposed to have just reached MDT at 1:00am tonight. As we now can see, almost all of the layers above us remain above 0 until the low is way off the coast. That would seem to me to mean that I doubt around here there is any sleet observed. Just ZR. At 10:30 I'm at 39.2 degrees with light rain, and have had 0.52" of rain for the storm / since midnight. I'll be sure to keep you updated as to the state of my snowpack (lol). It does appear to have decreased a little in thickness. However, it's still a solid 1.5" with a few more blades of grass poking through.

Just remember what I said back around 7:00pm...I said that I cannot see how CTP doesn't issue at least WWA's for the majority of us. Is 0.25"+ criteria for Winter Storm Warning? I keep forgetting if it's 0.25" or 0.50" threshold. I'm pretty sure it's a quarter inch as that alone would be a ton of ice on everything. I'm not rooting for this outcome, mind you. At the same time there is definitely a hidden level of excitement over what might happen. We're not going to find out until we're in the middle of it. Again, I am predicting Winter Weather Advisories for nearly all of the LSV most likely in tomorrow morning's forecast issuance. They have to provide 24 hours advance notice for this kind of event. And, as I finish typing this at 12:17am I just looked at my weather station and it says that it has just started to rain here. Temp 37.4 degrees. I guess that last time we had any rain, it was freezing rain at the end of the Sunday 1/16 snow>sleet>freezing rain>rain. Ok, another tick on the gauge with 0.02" of precip so far. See you all in the morning!

Well, unfortunately the GFS has kind of caved with this run at least as far as pure snow is concerned. Here are the differences between yesterday's 18z output (imby) and today's... Yesterday the total storm qpf was 2.12". Today it is 1.83" Yesterday the total freezing rain was 0.63". Today it is 0.38". Yesterday the total ice accrual was 0.50". Today it is 0.33". Yesterday the snow accumulation was 5". Today it is 0.00". Today's run has slowed down the arrival of the sub-freezing temperatures by over 3 hours. Yesterday the freezing line reached me by 10:00pm. Today it is 1:00am. If this is how the end results play out I would still say that the GFS handled the storm very well. I'm amazed at how consistent it's been going all the way back to Sunday. Virtually every run from then until just now it has put out the same kind of precip distribution. At least that's my own take for Carlisle. Currently the temp is down to 36.0 degrees and the dew point is 31.0 degrees. We know we're not going below freezing tonight. I'm curious as to has far north the warm air makes it during the later part of tomorrow afternoon. My very tenacious snowpack is still out in my back yard and still measures 2". I can't see the top of the grass yet. I really do not mind snowmelt when it occurs with sunshine and mild temperatures. However, there is nothing worse than watching the white gold fade away while it's pouring rain out there with any temp over freezing. The higher the temp the worse I feel...haha. I'm fairly certain a new mantle will make it here before the end of winter. As usual we just need to be patient. Our turn will come. PS>>I'm not saying this to make any of the snowless peeps feel any worse than they already do. Obviously we can't control the weather and it will do whatever it wants regardless of how it affects us individually. We all cash in eventually.

I don't see how most of us can't end up with a WWA. Isn't the criteria 0.10"+ of ice accrual? Also, I absolutely would not rule out the ice developing on highways even after an inch of rain and temps in the 40s. It's been darn cold here for over two weeks and many single digit lows. The roads are not going to warm up sufficiently with one day of rain. Maybe they stay on top of it on the major roads, but any secondary or local roads will be vulnerable to a rapid freeze. It looks like the temp is going to drop below freezing around 5:00am. That's almost 2 hours of darkness while these conditions develop. I totally agree with you, @anotherman.

Well after looking at 0Z, focusing imby a little bit...the picture has improved for more frozen and less freezing. Freezing rain now projected to be 0.58" vs 1.11 at 18z. Ice accrual instead of 0.63" it's down now to 0.38"...so less freezing rain overall this run. Total qpf now is 2.20" versus 2.12" at 18z. So total qpf stays virtually the same between those two runs. Finally, my 18z snow total was 3", but 0Z improves upon that up to 5". I don't know about any sleet amounts but I'm sure there is some sleet in the transition. Finally, Friday night looking frigid still with widespread single digit lows, including negative lows out west and north. Similar lows again Saturday night, maybe a few degrees warmer. For now I'm quite satisfied. Things are still in flux. Personally, I would focus on the overall strength of the high to our north in southern Canada. It's been showing pressures in the 1040's during the arrival of the arctic air. Watch to see tomorrow if that high gets any stronger, like up to 1045 or higher. 1045 is a pretty strong High pressure at about 30.85". You usually don't mess with Highs of that magnitude as they typically mean business. And a 1045 high pressing down on a measly 1007 Low isn't going to let that warmth come flooding into our area that easily. We'll revisit all of this in the morning.

So you noticed, huh? I was just reviewing the breakdown of precip volume and types. That little lighter color in the middle of Cumberland county is about 1.11". According to the GFS I will first have 1.23" of plain rain. By around 9pm Thursday evening my surface temperature falls below freezing. Then I have 1.11" of heavy freezing rain while the temperature continues to fall into the 20s. That 1.11" of freezing rain produces 0.63" of ice accrual, which, if materialized, would easily be classified as a severe ice storm. Then as an end of storm bonus, it changes over to snow around 9:00am Friday and finishes off with 3" of snow. The total qpf of everything for the event is 2.12" according to the Pivotal maps, however, adding up the individual liquids comes to around 2.50". So, I don't know how they calculate that, but maybe @MAG5035could explain?? If this played out verbatim there would be some winter chaos everywhere. We'll see if the GFS continues to insist on this colder solution at 0Z.

That's not quite true regarding no ice, but Bubbler is right about a substantial reduction of the freezing rain due to a delay in the push of arctic air vs heavy precip. Here's a comparison between 12z first: Compared now to 18z... So as you can easily see, a drastic reduction in freezing rain as the heavy precip pulls through while temps stay warmer longer. Checking surface temps first 12z Friday: MDT hits 32 at 7am Friday morning with a fair amount of precip still to come. Versus 18z temps: look at 4:00am first followed by 7:00am. Temp at MDT crashes 17 degrees in 3 hours... 7:00am I won't post the snow maps because both runs give the entire lsv a big goose egg. I'm definitely anxious to see the 18z GFS to see if it begins to abandon ship or not.

If you love the cold, just take a look at surface temps through the entire 12z (GFS) run. You'll be somewhat shocked, starting with sub-zero lows Friday night for the northwest 80% of the state. LSV is low positive single digits. Lows for Saturday night are a tad milder (lol). After the brief warmup Thursday there is only one more warmup modeled with temps in the high 30's later in the run. Whole rest is sub freezing day and night. It looks just as cold as the cold we just had for January, and right now the cold pattern continues until Valentines Day. If the ice/zr ends up being substantial, it may not melt for many days. One other person just mentioned 1994. I was going to remark yesterday that the upcoming pattern looks and feels a lot like early 1994. I'm not expecting -20 at MDT during the remainder of winter, however. For Carlisle the GFS paints almost 0.90" of freezing rain which creates 0.50" of ice accrual. If that came true this would be a severe ice storm. In 1994 in NJ in early January we had the same thing...one of most severe ice storms I've ever seen. That's what preceded the record-setting low temps that caused MDT to drop to -22F which became their all-time record low temperature which still stands to this day.

Low this morning was 11.7 degrees which was a bit of a surprise. I am certain the continuing snowpack enhanced the chill.

Here's one last map to send you off to weenie land with pleasant dreams: I forgot to take a look at the second follow up storm. We can dub it the super bowl snow! The timing of this has the meat of the second storm occuring at game time but not finishing until nearly midnight. Here it is added to the Friday storm. Around MDT it doubles the total meaning the 2nd storm delivers about the same or just a little more (an inch?). Where the real difference lies is m/d counties, esp Lanco where nearly all of the snow depicted here is just from the Sunday storm.

One correction is that the TT snowmap above does not include any freezing rain. Only snow and/or sleet. Based on the snow-only map I'm about to show, one can infer that a huge amount of sleet is going to be all over the southern tier. Here's 10:1 snow only And, here's Kuchera... When compared to 18z there isn't much difference for accumulations of snow close to MDT. 0Z run has less snow down close to the m/d border. Here's the freezing rain: It looks like freezing rain ends around or by 4:00am Friday followed by the sleet storm. Freezing rain qpf a little lighter by about 0.15" at MDT; I'll try to give a rough estimate for the start time of pure snow...but first the ice accretion map: Still about a third of an inch of accrued ice...pretty substantial, especially if sleet and snow are going to follow behind. Here's the map that shows the time around when the conversion from sleet to snow takes place: 4:00am northern lsv counties: Southern counties follow a few hours later by around 9:00am; next map is time of first snow reaching MDT, around 6:00am... Finally, 10:00am it has reached the southern border counties: Based on all of these maps showing the transition of p-types it appears that there isn't a major sleet storm despite the portrayal by TT map. Looks like no more than a few hours between zr and snow.

Since I didn't know the snow output from storm 1 is roughly twice what storm 2 delivers. More than half the forum is 6+ for the 2-storm total. This looks good! I don't know why frownie faces have been moping around here today. lol

Haha! Before I decided to create the post I checked to see if you were online! When you weren't, I figured I could beat you to the punch...lol.

Why is no one talking about the improvements in snow for our area on the 18z? There was a noteworthy increase that also pushed quite a bit southward. Also, if this depiction comes true we will have a major ice storm that precedes the sleet then snow. MDT receives 0.84" of freezing rain that has an ice accretion of 0.38", which would be pretty substantial for around our area. Here are the 18z maps: First, the freezing rain accumulation: That's a lot of rain with temps below freezing. Next up is the ice accretion map: The approximate time for the freezing rain period is starting around 7:00pm Thursday northwest lsv to around 9:00pm southeast lsv. It's all over in less than six hours with the freezing rain transitioning over to sleet in the wee hours and then over to snow a few hours later, followed by the much-improved snow maps: Here's 10:1 and here's Kuchera: The snow actually falls for nearly 15 hours before ending around midnight Friday evening. A very long duration event in total. Also, once the temp drops to 32 it then proceeds to plunge pretty quickly, dropping to 20 degrees before dawn and then remaining around 20 degrees for the rest of the snow portion.

I decided to get the maps for the entire run and lsv improves a fair amount...but look at what happens to the north and western PA... First map is 10:1 And then take a look at Kuchera (lsv doesn't improve but boy does north and west...Even look at Pittsburgh!! It's like a snow bomb goes off (but misses the LSV because of storm 1). Tracking should be pretty exciting this week for sure!

Here are the two maps with the sleet removed. The event goes beyond hour 96 and that is the 12-hour period where the storm ends as snow:.. First Storm: This map implies that the majority of the event for lsv is sleet, ending as snow before 12z Saturday (when compared to the TT map that includes sleet) And here is the second storm (by itself, without first storm): and finally, here they both are combined... and combined zoomed in for PA... If it plays out like this, it's a real winner (even for most of Lanco!)

While we're on the subject of the Euro, unfortunately it took a rocket-step back. I think the Ukie is playing catch up and is off by 12 hours. Here's last night's 0Z snow map: And here is today's 12Z... And, here is the freezing rain from 0Z... and here is today's 12Z... and finally, here are the total qpf's (nearly 100% of this occurs from the Thur/Fri event)... and here is today's 12z...

Well we know today and tomorrow will be more than 2 degrees below normal. That just might push us up close to 40th (lol). After checking the MDT data we are 2.3 degrees below normal (average). I would think we could make it to -2.5 or -2.6. Just have to wait and see.

10.8 degrees this morning was the best I could do. Still have a good 2-2.5" of white ice-pack. Today marks day 15 of continuous snow cover, which is nearly the entire second half of January. I haven't checked the MDT monthly departure yet but I'm willing to bet they're at least -2 degrees. It seems like it's been so long since we've had a below January. The polar vortex winter ('14-'15?) would have created a below January I'm sure. Temp is up to 17.1 degrees on its way to the upper 20's.

@Blizzard of 93 Ok, I did include something you didn't have which was quantifying the freezing rain portion of the storm as well as the preceding 0.60" of rain. Now I feel better...lol.

Wow, Blizz, as usual I end up composing something that you are a few steps ahead of me with. Maybe there's something there that you left out that I included?

Well, I just scoured through the 12z Euro and wow for this upcoming event. It's going to have almost every form of precip during the course. For MDT it starts off with 0,60" of rain; that is then followed with 0.37" of freezing rain with a significant 0.30" of ice accretion from the freezing rain; then it transitions fairly quickly over to snow (with a likely short period of sleet thrown in too) which quickly accumulates 6". About 1.5" total qpf out of it, which is amazing if it plays out this way. Definitely gets the tracking juices flowing again after our brief 24-hour break. I haven't looked yet but I'm guessing that the arctic air comes running in behind the front which is tilted 45 degrees running SW to NE. Potential fun times ahead as we begin our first week of February.

As of about 10:45 the snizzle has ended and the clouds are breaking and I've even seen a few stars. So, that's it for me for this one. No additional accumulation has occurred since my last post back around 10:00. So recapping...0.1" with round 1 back in the wee hours this morning. 0.3" with round two this evening. Total snowfall recorded for today will be 0.4". I'll melt it down in the morning, if it hasn't all evaporated by then with the wind that has now begun. Looks like 5 mph steady or so now. Will be a lot more in the morning. Season-to-date snowfall now is up to 12.5". Temp continues to drop and is now down to 24.4 degrees. I think tomorrow will likely be the coldest day for my maximum temperature this season with it forecast to barely crack 20 degrees. So far the coldest daytime max has been 24.