Special Weather Discussion

Latest Weather Discussion by Kyle Elliott

* Major Winter storm to wreak havoc sunday; polar plunge follows *

Brief 5:30 p.m. Saturday, January 24, 2026, Update:

I made a few tweaks to yesterday's Storm Outlook Map this afternoon, primarily to increase snowfall totals across parts of Ohio, New York and western PA and allow for mixing farther north and west from PA into southern New England (see below). The primary low is indeed expected to reach northern WV or southwestern PA Sunday afternoon/evening, allowing the warm nose to punch into southeastern PA and the Lower Susquehanna Valley. As a result, snow will changeover to sleet from southeast-to-northwest across the region beginning around midday on Sunday. There is still some uncertainty as to how quickly the changeover to sleet occurs and how far north/west the mixing line gets, and this could have a significant impact on actual snow/sleet totals in your backyard. In Adams, York, Lancaster and Chester Counties (and others in southeastern PA), snow could changeover to sleet as early as 1-3 PM Sunday afternoon, while the changeover could be delayed until 6-7 PM north/west of Harrisburg. The heaviest snow should fall between 7 AM-3 PM Sunday, and rates could reach 1-2" per hour at times during that window. Actual snowfall amounts may be in the 6-10" range across the aforementioned counties, but 1-3" of sleet could fall on top of that after the changeover. Farther north and west, snowfall amounts of 10-14" should be more common with perhaps a coating to 1" of sleet on top of it. No matter the ultimate outcome and eventual distribution of snow/sleet amounts, this will still be the biggest and most impactful storm in about 5 years across the entire region. Snow/sleet should end from southwest-to-northeast between ~7-11 PM Sunday evening, but freezing drizzle or intermittent, light snow showers could linger overnight. Any leftover precipitation will end by daybreak on Monday.

The far-reaching and extreme impacts from the winter storm remain the same and were outlined in yesterday's discussion below. Behind the system, gusty winds will usher Arctic air into the mid-Atlantic States from Monday into Tuesday, and the record-challenging cold won't be going anywhere through the end of January. Temperatures will not reach the freezing mark (32°F) again until February and perhaps not until after the 5th-7th of the month. Blowing and drifting snow will be a problem for days, especially in areas north/west of I-76/81 less impacted by sleet. Regardless, next week's "Polar Plunge" will hinder cleanup efforts and cause secondary roadways to stay icy/slippery/treacherous for days or even weeks. Power outages are also expected, so make sure to have plenty of gas in backup generators and your vehicle and extra supplies like food, water, coats, blankets, gloves, etc., on hand.  Avoid travel through Monday, and minimize time outdoors next week due to the frigid conditions and dangerously low wind chills. Stay safe over the next few days, and check back Tuesday for an update! -- Elliott

5:30 p.m. Friday, January 23, 2026, Update:

After waiting nearly 5 years, snow-lovers and winter-weather enthusiasts across the Lower Susquehanna Valley are finally going to experience another widespread, double-digit snowfall on Sunday. The winter storm will indeed qualify as a "major" one regardless of the exact amount of snow in your backyard. An Arctic cold front currently sweeping through the Commonwealth from northwest-to-southeast will set the stage for the storm and signal the arrival of a bitterly cold air mass later tonight into Saturday. A Cold Weather Advisory is in effect from 10 PM this evening through 10 AM Saturday morning. Behind the front, temperatures will plummet rapidly during the mid-to-late evening hours and end up in the single digits above zero early Saturday morning. However, wind chills could be as low as 15°F below zero due to a 12-25 mph north-northwesterly breeze (see below). Fortunately, winds will subside later Saturday morning, but the cold will indeed be of the "dangerous" variety for 12-15 hours. Uninsulated and unprotected pipes could freeze or burst, and exposed skin could develop frostbite within 30 minutes or less. Thus, it will be imperative to dress in layers, cover up exposed skin, and limit time outdoors (see below). Make sure you have at least a half tank of gas in your vehicle, as well, to prevent fuel lines from partially freezing. A Canadian high pressure system will settle over the eastern Great Lakes region on Saturday, and the deep, Arctic air mass combined with increasing clouds will prevent high temperatures from exceeding the mid-to-high teens. Sadly, it only gets worse from there..

Our complex, far-reaching and powerful storm system will take root in the Deep South Saturday night and track northeastward into the central Appalachians on Sunday. At the same time, a secondary low pressure system will form near Cape Hatteras and then move north-northeastward just off the mid-Atlantic coastline through Sunday night. A winter storm of this variety is often referred to as a "Miller B" by meteorologists. Essentially, the primary low over the Appalachians will "transfer" its energy to the secondary low along the coast. However, therein lies the forecasting headache. The speed at which this "transfer" occurs will be paramount in determining the northward and westward extent of the "mixing line." If the primary low weakens more rapidly and the secondary low strengthens more quickly, the "mixing line" will stay farther south and east. If the secondary low is slower to strengthen and the primary low remains intact longer.. i.e. reaches northern WV or southwestern PA.. the "mixing line" will surge farther north and west (see below). Regardless of the eventual outcome and in either scenario, the impacts will be severe and extreme.

Snow should overspread northern MD, southeastern PA and the Lower Susquehanna Valley from southwest-to-northeast between ~10 PM Saturday and 2 AM Sunday, fall heavily at times later Saturday night through Sunday afternoon, and then taper off Sunday night. A few light snow showers may linger into Monday morning, but these would be of the intermittent and non-accumulating variety. The snow will likely mix with or changeover to sleet south and east of Interstate 81 Sunday afternoon or evening before ending, ultimately slashing snowfall totals across parts of Adams, York and Lancaster Counties (see below). Snowfall rates may briefly reach 1-2" per hour in the heaviest bands on Sunday, and temperatures will only be in the teens to perhaps 20°F during the storm. Total snow and sleet accumulations should range from 8-12" inches across southern Adams, York and Lancaster Counties to 12-18" north of the Turnpike and along/west of the South Mountain Range. I posted my "Storm Outlook Map" earlier this afternoon to show the distribution of expected snowfall totals across the Ohio Valley, central Appalachians, mid-Atlantic States and southern New England (see below). Roadways will be virtually impassable from Saturday night through at least Monday morning, and most schools and businesses will be closed.. or have already announced closures.. on Monday. Avoid travel during the storm, and stock up on extra supplies, blankets, water and groceries now! In the event of a prolonged power outage, the internal temperature of your home could drop rapidly and fall into the 30s or 40s within just 1-2 days, so it's best to be properly prepared for such an event. 

Behind the storm, roadways are going to freeze solid next week. Call it the "Arctic Express," "Polar Plunge," or whatever you want, but this next discharge of Arctic air means business. It could break temperature records and will be downright dangerous! In fact, the coldest air in North America, relative to normal, will invade the Northeast and mid-Atlantic States during the middle and latter part of next week. Extreme, high-latitude blocking will combine with a massive ridge, or northward bulge in the Jet Stream, over western North America to dislodge the Tropospheric Polar Vortex (TPV) and force it into the Northeastern United States next Tuesday-Friday. Howling, northwesterly winds of 12-25 mph with gusts up to 40 mph will direct the initial pool of Arctic air into the region from Monday into Tuesday. After highs reach the low-to-mid 20s Monday afternoon, temperatures will plunge into the single digits above.. or perhaps even below.. zero early Tuesday morning and only reach the teens Tuesday afternoon. This feat is then likely to be repeated each and every day through the end of the week. Wind speeds should be lower on Wednesday but then ramp back up late in the week. As a result, wind chill values could thud to -15°F to -25°F several nights/mornings next week, and that kind of extreme cold can be very problematic. Not only will road treatment chemicals fail to melt snow/ice off area roadways, but cars may not even start on most mornings next week. The only bit of "good news" I have to offer is that there should be no more than intermittent snow flurries/showers throughout the week with little or no accumulation. Record low maximum and minimum temperatures are generally in the teens and negative single digits during the last week of January, so these could easily be challenged or broken on four consecutive days. Not since early January 2018 or February 2015 has there been an extreme cold shot of this duration across the mid-Atlantic States. However, this will essentially be a "worst-case scenario" since it's coming on the heels of a major winter storm. Needless to say, I cannot stress the importance of being properly prepared NOW! Again, stock up on extra food, blankets, water, winter coats, flashlights and other supplies over the next 24-30 hours, and minimize or avoid time outside next week. Exposed skin could develop frostbite in a matter of minutes on some mornings, so cover up all exposed skin if you must go outdoors. Batten down the hatches: Old Man Winter is about to come roaring back, and he won't be going anywhere for awhile.. -- Elliott 

2:30 p.m. Wednesday, January 21, 2026:

For the first time in 5 years, the potential exists for a double-digit snowfall across northern MD, southeastern PA and the Lower Susquehanna Valley this upcoming weekend. Not since January 31-February 2, 2021, has a 12"+ snowstorm impacted Millersville University. There hasn't even been a 6" event at the 'Ville in the past 4 winter seasons, but that may change from Saturday night into Monday morning. The stars certainly seem to be aligning for a "major snowstorm" during the second half of the weekend, but Sunday is still 4 days away. Thus, a prudent meteorologist such as myself will only talk in terms of "potential" at this distance, and we all know that you can't shovel potential. More to come in a bit..

A deep trough, or dip in the Jet Stream, over the Northeast promoted sunny, brisk and unseasonably cold conditions across the mid-Atlantic States on Tuesday. A Canadian high pressure system then settled over the Delmarva Region last night and caused winds to subside. The combination of clear skies, light winds and a fresh snowpack provided the ideal setting for efficient, radiational cooling, and temperatures bottomed out in the negative single digits across much of southeastern PA and the Lehigh Valley early this morning. It was the coldest morning since January 22/23, 2025, in most spots, and Lancaster Airport recorded a bone-chilling low of -7°F (see below). While impressive, this Arctic blast is a far cry from the historic Arctic outbreak in January 1994. On this very day 22 years ago, the mercury plummeted to -18°F at Millersville.. the all-time record low at the University since 1914 (see below). Anyhow, the aforementioned high pressure system has shifted into the western Atlantic this afternoon. On its backside, southerly winds of 12-25 mph have ushered a more seasonable air mass into the region, and temperatures have reached the low-to-mid 30s at the time of this writing. Wind chills remain in the 20s due to the southerly breeze, but the outdoor air certainly doesn't feel as harsh as yesterday.

A weak, clipper-type system will zip through southeastern Canada and New England tonight, but no more than a stray rain/snow shower is expected to reach areas north/west of I-81. Behind and well south of the disturbance, west-southwesterly winds of 12-25 mph will then direct even milder air into the region on Thursday, and high temperatures should be 5-10°F above average.. ranging from the mid 40s along I-81 to low 50s in the I-95 corridor.. under mostly sunny skies (see below). A cold front will then traverse the Commonwealth from northwest-to-southeast from Thursday night into Friday morning, but no precipitation will accompany its passage. Behind it, winds will turn northwesterly Friday afternoon and usher colder air back into the Lower Susquehanna Valley. After a seasonably cold Thursday night with lows in the low-to-mid 20s, high temperatures will likely be at least a few degrees below average Friday afternoon (low 30s along I-81 to the upper 30s or low 40s near I-95).

A secondary, Arctic front will sweep through the region Friday evening, signal the arrival of a bitterly cold air mass later Friday night into Saturday, and set the stage for our impending winter storm. Behind the front, temperatures will plunge rapidly Friday evening and end up in the single digits above zero early Saturday morning. However, wind chills could be as low as 5-15°F below zero due to a 12-25 mph north-northwesterly breeze. Fortunately, winds will subside Saturday morning, but the cold will indeed be of the "dangerous" variety this go around. Uninsulated and unprotected pipes could freeze or burst, and exposed skin could develop frostbite within 30 minutes or less. Thus, it will be imperative to dress in layers, cover up exposed skin, and limit time outdoors Friday night into Saturday. A Canadian high pressure system will settle over the eastern Great Lakes region on Saturday, and the deep, Arctic air mass combined with increasing clouds will prevent high temperatures from exceeding the mid-to-high teens.. a warm-weather lover's worst nightmare..

By Saturday afternoon, all eyes will be on the dynamic, complex, high-impact and far-reaching winter storm developing across the Central and Southern States. Since the storm is still 4-5 days away, it's too early for me to release details such as expected snowfall amounts, arrival/end times of snow and max snowfall rates. However, one thing is already clear. With temperatures in the teens to perhaps low 20s throughout the storm, impacts will be extreme and occur across a massive portion of the nation. Roads will essentially be impassable later Saturday night through perhaps Monday, and airport delays/cancellations will be widespread (see below). I offered my take on the winter storm earlier today on Twitter/X and outlined some of the factors to keep a close eye on over the next 24-48 hours (see below). These "players" will serve a vital role in determining the eventual track, timing and intensity of the storm, as well as the axis of heaviest snowfall and northward/westward extent of any mixing issues with sleet/freezing rain.

At this point, I am most concerned for the system to continue trending north, and that could lead to snow mixing with or changing over to sleet/ice perhaps well into PA. Before that changeover, there could be quite a legendary "thump" of heavy snow across northern MD, southeastern PA and the Lower Susquehanna Valley. The system will be attacking a deep, antecedent Arctic air mass, and the Canadian high pressure system will shift into New England on Sunday and continue to funnel cold air down the eastern slopes of the Appalachians. Thus, the large-scale pattern is certainly favorable for a double-digit snowstorm, but I won't be able to provide exact details and release numbers until Friday. However, schools and businesses will likely be closed on Monday, and a "plowable snowfall" is already a virtual lock barring a dramatic northward shift in the system's track. Due to the extremely cold air mass in place, snowfall ratios will likely be around 20:1, at least during the first half of the storm, so it won't take much liquid equivalent precipitation for "big totals" to occur. I advise stocking up on supplies and groceries late this week well before wintry precipitation begins. Depending on how much snow falls, it could take a couple of days to clear secondary roadways. Either way you slice it, Old Man Winter is about to make a roaring comeback, and the next two weeks will be filled with storms and rumors of storms.. yuck! -- Elliott