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My forecast says snow likely, moderate snow accumulation Saturday, high near 32, sat night snow likely, mixing with sleet and freezing rain, changing to all freezing rain after midnight, moderate snow accumulation, low near 24, it doesn't mention ice accumulation totals at all.

This is pretty reasonable.

This'll be reduced, dramatically! But we'll save it for entertainment purposes.

2 questions with winds this high and temps in the teens and heavy snowfall why isnt the blizzard word being used? also 2 is the storm lasting longer then earlier model runs from today last night? saw 2 diff models in videos today showing snowing monday afternoon till 4 instead of wrapping up like 2am

I decided to go ahead and post the rest of the the discussion I'm thinking some of you fellas might like it archived here. Now if you really enjoy meteorology and want to know *why* we are predicting the most significant accumulations in the past 5+ years, feel free to read on through the remainder of this KEY MESSAGE 2 discussion. We`ve had our fair share of cold snaps this winter season, and tomorrow (Friday) will be no exception after the next Arctic front pushes through. A large factor driving all this cold weather has been the Polar Vortex displaced from the North Pole, with a tendency for the vortex to find itself over Hudson Bay and northern Quebec. With displacement that far south, we`ve gotten plenty of cold air, but it`s also nudged the storm track south of our area for many of the recent events. If you`ve ever heard people say "it`s too cold to snow", it`s not that it`s physically too cold to snow, it usually just means that the storm track has shifted far enough to the south that we end up under dry high pressure while our temps are cold. One key difference this time is the influence of a Pacific storm, located off the coast of southern California this evening, and a strengthening subtropical jet to its south. Over the next 24 hours these features will cross the Baja Peninsula of Mexico and then into Texas. Southwesterly flow out ahead of this southern stream feature will pump warmer air into the Gulf Coast and Southeastern US Saturday night into Sunday. At the same time, a northern stream shortwave trough coming down from western Canada into the Great Plains will bring a reinforcing shot of cold air to the back side of the northern longwave trough. The increasing temperature gradients will result in an overall increase in wind speed aloft at jet stream altitude, and an amplification of the northern stream trough and ridge. By Sunday, the right entrance region of the northern jet and the left exit region of the southern jet will align to produce enhanced upward motion through the troposphere. Remaining uncertainty in the forecast largely depends on the degree of phasing of these two jets, the angle at which they align, and how much amplification there is of the ridge out ahead of the deepening trough. The very cold air in place ahead of this system also plays other crucial roles to increase impacts. At 00Z Sunday, model consensus depicts a 1040+ mb high over New York State, which only slowly moves northeastward across New England over the next 24 hours. The deep, cold blocking high to the northeast of a winter storm is a textbook feature that supplies a stream of cold air down the Alleghenies and provides a cold dome for warmer, less dense air parcels streaming in from the southwest to ascend over. That upward motion is key to production of hydrometeors - in this case snow. And then there is the key role that cold temperatures have on ice crystal habits. The so called "dendritic growth zone" exists where temperatures are between roughly 0F and 10F. Given low temperatures Saturday night in the single digits, some spots might start off with a DGZ that extends from the ground up 10,000 to 15,000 feet which is pretty remarkable for a large synoptic storm in this region. As long as the column saturates quickly enough, any snow that falls late Saturday night and into early Sunday morning could be very high ratio, fluffy, rapidly accumulating snow that consists of many pristine dendrites (SLRs 15-20:1, could be even higher if the column saturates faster but there is dry air at low levels to overcome at onset). So after a few hours of virga, accumulations have the potential to begin with a vengeance in the predawn hours Sunday, especially from I-80 south. KEY MESSAGE 3: Arctic blast persists with frigid temperatures and subzero wind chills expected next Monday all the way through next weekend. A prolonged stretch of frigid temperatures continues next week through the end of January (next weekend). After the cold snap Fri night - Sat, the next round of cold wx headlines (-10 to -20F wind chills) is likely Monday night through Tuesday morning. Given the prolonged nature of the bitter cold, we may begin to see more infrastructure impacts (frozen pipes) by next week. Occasional lake effect/upslope snow showers are likely next week under a very cold cyclonic flow aloft.

Think they have removed the ice accumulation from your point forecast.

HHHR is impressive for the forum. Another trend south mostly and temp profiles are colder. I’m currently at 29 imby. .

They made that mistake 2 years ago. .

New BOX map LFG!!!!

Another forecast discussion should be available in about an 1.5 hours, but I still feel this was a pretty interesting read, with a lot more explanation then generally seen. It's a very lengthy discussion, so I only posted part of it here, the rest will be in the link if anybody wants to read it before the next update. 436 FXUS61 KCTP 230420 AFDCTP Area Forecast Discussion National Weather Service State College PA 1120 PM EST Thu Jan 22 2026 .WHAT HAS CHANGED... * Increasing chances for heavy snow this weekend. More details provided in discussion section. && .KEY MESSAGES... 1) Frigid temperatures and dangerous wind chills expand from northwest to southeast Friday afternoon into Saturday morning 2) Increasing odds for double digit heavy snow accumulation and widespread moderate to major winter storm impacts Saturday night through Monday morning, heaviest on Sunday. 3) Arctic blast persists with frigid temperatures and subzero wind chills expected next Monday all the way through next weekend. && .DISCUSSION... KEY MESSAGE 1: Frigid temperatures and dangerous wind chills expand from northwest to southeast Friday afternoon into Saturday morning.Arctic air is poised to return to the forecast area - filtering in from northwest to southeast through Friday night. High confidence in -10 to -20F wind chills across all of central PA Friday afternoon into early Saturday morning approaching extreme cold criteria in the Laurel Highlands. Frigid Arctic air will remain in place prior to the onset of the significant winter storm this weekend. KEY MESSAGE 2: Increasing odds for double digit heavy snow accumulation and widespread moderate to major winter storm impacts Saturday night through Monday morning, heaviest on Sunday. Snow accumulations will likely begin with a vengeance from south to north in the predawn hours Sunday. Periods with snowfall rates greater than 1 inch per hour are becoming increasingly likely in the isentropic ascent early Sunday and as low and midlevel frontogenesis becomes stronger later in the day and evening. Given the dry, fluffy snow and wind gusts of 15-30 mph, there will likely be some blowing and drifting. There could be a period of sleet especially across the southern tier Sunday evening cutting into snow totals just a bit, but not before double digit accumulations are expected to fall.While warm advective, front-end snow is becoming increasingly likely, there is considerable model uncertainty with the placement of a comma head area of snowfall as a secondary low pressure system develops offshore (in a Miller B type evolution). If the comma head sits over central PA Sunday night, several additional inches of accumulation are possible. However, if it misses us to the north and we see more of a dry slot, that would result in snow ending sooner Sunday evening with less accumulation overnight. All in all, the probability of snowfall amounts exceeding 12inches has increased to 60-80 percent across much of central PA. The probability of more than 18 inches ranges from 15 to 40 percent. Amounts near 24 inches can`t be ruled out (10 percent chance) especially if the comma head sits over central PA Sunday night. Always prepare for the worst case scenario and continue to check the forecast as it evolves. Now is the time to prepare. Think snow blowers, re-arranging travel plans to avoid travel during the storm, what to do in case of a power outage, etc. Remember it will be very cold before, during and after the storm. Never run a generator indoors due to carbon monoxide. Now if you really enjoy meteorology and want to know *why* we are predicting the most significant accumulations. https://forecast.weather.gov/product.php?site=CTP&issuedby=CTP&product=AFD&format=CI&version=1&glossary=1&highlight=off

Watches up now here. BTV still highlighting potential for greater than 20:1 ratios which seems extreme but we’d take.

I haven't looked.

Have you read MRX 1am AFD..almost sounds like south of 40 in the valley will be lucky to get a WWA.

Now that we are in the final 24 hours, I have to step back and be objective here, I think the models don't handle the warm air layer well. WAA might be stronger than indicated causing a lot of the snow to become sleet as I remember this happening with one of our big winter storms just last year after the models went nuts with 12+ beforehand. Likely this will be an issue during the first wave until the cold air layer deepens. Especially areas further south and east of US60 and I-35. Might be best to take these totals and half them. With that being said the QPF is still holding steady if not increasing. Many may still see close to a foot of snow. Just my two cents.

Oh they will, but the damage has been done. In the past they have dug in and said so it was mostly sleet so what… see March 2017. At least this time we will go in knowing not to expect big snows. This crap will not be easy to clean and the ERs are gonna be busy. The biggest danger here is going to be for middle aged men.

Trust me I want the highest totals out of anybody lol, but reality is we have seen a warming trend, again we could be sitting here tomorrow night happier than a pig in shit, it could get worse as well. Hopefully we get the first rather than the latter. See you guys for 6z.

Probably meaningless, but the Euro says I should be 31 right now, I'm 26. The 18z HRRR that just initialized off last hour is close, showing me at 27 at this hour, but the HRRR two hours ago was 3-4 degrees warm looking out to 2am. I'm basically 4-5 degrees cooler than all other modeling.

Wouldn’t be surprised to see some stay in the 30s today .

I guess with this storm dumping sleet and freezing rain all over the country, it's just decided that it's going to do the same thing here. Fun times.

From storm of the century in the media to 6-8… so when do we all end with a March 2017 situation….im never comfortable when sleet is on the table.

If it were falling on something already covered in snow, yes....the crystalline structure of the individual snowflakes changes the surface of the aforementioned curved object (branches, powerlines)...crystals have many edges and sharp angles that grab and hold, which is why they can stick to a curved surface Plus the cohesive and adhesive forces of water come into play, especially when the snow is slightly wet. Adhesive forces are what allow water molecules to stick to an object, and vice-versa; cohesion allows water molecules to stick to other water molecules With this in mind, sleet would definitely stick best to wet snow on branches or power lines

Keep in mind, these maps include sleet. It may start as brief snow, but predominant p-type in NC will likely be sleet.

also now one 2 models show it snowing in north md and south pa till like early afternoon mon a lot longer then before

That's absurd. Computer generated is fine but every 10 minutes? Gonna confuse people.

shhhhhhhhhh!!!!!!!!!!!