| January 07 2025 |
Early January Winter Storm: (1/4 - 1/6)
By: Scott Kleebauer, WPC Meteorologist
Meteorological Overview:
The year 2025 kicked off in a grand way with a potent disturbance migrating west to east across the Continental U.S. with a substantial snow and ice footprint encompassing areas of the Inter-Mountain West through the Plains, eventually subjecting the Mid Atlantic to its biggest winter storm in several years. The pattern evolved from a robust shortwave trough that entered the Western U.S. from the Pacific with an already formidable precipitation output across the Pacific Northwest in the form of heavy coastal rain and snow over the Cascades and Northern Rockies. The upper level pattern would become even more amplified as it traversed the Rockies with the primary energy becoming increasingly consolidated as it migrated into the Central Plains. At the mid-levels, the robust yet open trough over the Central Rockies began to manifest into a much stronger, amplified upper-level disturbance as the energy rounded the trough base and tried to separate from the mean flow aloft. The evolution was a textbook case of upper wave amplification as the disturbance ejected off the lee of the Rockies, something that has historical significance during the cold season due to an increasingly baroclinic environment available once disturbances maneuver out of the mountainous regions of the Western CONUS.
The amplifying nature of the setup led to potent low to mid-level closed circulations within the 850-700mb height field, an evolution that would prove to be one of the more important aspects of what transpired in terms of appreciable weather extending from the Central Plains all the way across the Ohio Valley before finally ejecting off the Atlantic seaboard come the evening of January 6. Cold air was plentiful across the eastern two-thirds of the country thanks to a sprawling Arctic high pressure regime that transpired prior to the disturbance making headway into the Central CONUS. Temperatures at the surface across the Central Plains into the Mississippi Valley were well-below average with a significant portion of places from eastern Kansas through Missouri and points east sufficiently below freezing prior to the introduction of any precipitation into the region. A rapidly evolving surface low maturation process began by the afternoon of Jan. 4 across the western High Plains with cyclogenesis occurring over the southern Colorado Front Range near Pueblo. As the disturbance began intensifying through the Plains, the strong Arctic high over southern Canada began flexing its power in tandem with the evolving surface cyclone creating a fairly tight pressure gradient pattern over much of Kansas into Missouri and Illinois by the morning of Jan. 5. Weather conditions deteriorated during the afternoon of Jan. 4 as low to mid-level moisture with origins from the Gulf began streaming poleward within the eastern flank of the closed circulations situated over central Kansas. The established warm-cold conveyors within the bounds of the cyclone presented a textbook case of warm-frontal precipitation generation across the Lower to Mid-Mississippi Valley streaming northward, eventually interacting with the defined cold airmass encompassing areas along and north of I-44 in Missouri. Snow was the primary precipitation type over the Central Plains of Kansas and southern Nebraska thanks to the region being underneath the closed 850mb and 700mb lows allowing for sufficient top-down dynamic cooling to work with the strong cold push at the surface thanks to a sprawling 1043mb high pressure to the north. The northern portion of Missouri also maintained its position within a primary snow precipitation type as the region was able to shield off the warm air intrusion that was advecting north due to the intense warm-conveyor processes within the storm’s life cycle. Ice became the primary precipitation type for areas south of the snow line due to sufficient surface cold advection established, but a moderating lower boundary layer thanks to the aforementioned warm air intrusion taking place between the 925-700mb layers. Forecast soundings across central Missouri through southern Illinois and Indiana for days maintained a strong warm nose signature indicative of a majority freezing rain/sleet precipitation output, a forecast that ended up verifying with a solid degree of lead time when forecasting the event. This, of course, led to significant impacts across the areas affected by ice, an issue that would migrate eastward into the Eastern CONUS by the time we reached the night of Jan. 5 through Jan. 6.
By the overnight of Jan. 4 into Jan. 5, the surface low had reached its peak maturation process with a corridor of heavy precipitation translating eastward through the East-Central Plains, eventually breaching the Appalachian Front by the time we reached the late morning of the 5th as southwesterly flow began advecting moisture ahead of the terrain in the Mid Atlantic. Heavy snow with blizzard conditions was present across eastern Kansas into northwestern Missouri through the morning of the 5th with the Kansas City metro and surrounding locales subject to near white-out conditions as winds gusted over 40mph with heavy snowfall that managed to blanket the area over several hours once the snowfall began earlier the day prior. Farther east, snow and ice continued across the Ohio Valley extending from Indiana through Ohio/Kentucky/West Virginia with moderate to heavy precipitation providing significant accumulations with respect to both primary precipitation types. Snow began breaking out across the southern Blue Ridge by late-morning Jan.5 with a slow push of the precipitation shield to the northeast thanks to very dry antecedent conditions within the lower boundary layer north of I-66 in Virginia. Warmer air eventually flooded the lower boundary layer enough across the southern Blue Ridge by late afternoon Jan. 5 creating a more mixed precipitation output, eventually shifting to all ice in the form of sleet and freezing rain that would linger through the evening hours. By nightfall, the snow spread north across the Delmarva with most areas between Richmond to DC seeing snow prior to the next calendar day (Jan. 6) and areas north and northeast seeing snow breakout quickly after midnight local time as the column moistened sufficiently over the prior several hours. The event started out in earnest where precipitation was occurring with a quick transition from light to moderate snowfall into and through the evening.
Low pressure over the Ohio Valley would eventually reach east of the Appalachians by the morning of Jan. 6 with significant snowfall occurring over Central VA up toward the Mason Dixon Line. The mid and upper level evolution continued to play a significant role in the placement of the heaviest precipitation as the disturbance’s motion west to east helped maintain a relatively seamless avenue of where the greatest forcing aligned creating a corridor of greatest precipitation output and sustained heavier rates. This provided a well-defined axis of heavy snow aligned from the Ohio Valley through Central and Northern Virginia up into the southern half of Maryland and the Delmarva region. Snow intensities reached their highest levels in the Mid Atlantic between 2-9am during the first round of event when the warm air advection snow regime was at its peak as a strong low-level jet was able to usher appreciable moisture into an already frigid environment. A small lull occurred during the afternoon of Jan. 6 as the lagging upper trough was still migrating out of the Ohio Valley, but by nightfall, a second round of snow began breaking out over the Central Mid Atlantic providing one last burst of moderate to heavy snow to impact the area extending from southwest Virginia to the Mason-Dixon line.
The storm finally came to a close overnight Jan. 6 into the early morning hours of Jan. 7 as the primary low and upper trough ejected into the Atlantic leaving behind a swath of significant snow and ice totals in its wake. The post-storm environment was relatively tame compared to other storms that take a similar evolution as the pressure gradient in the wake of the disturbance was relatively weak. Some colder air did filter in creating lingering issues of black ice development for any snow/ice that did melt, but overall there was little in the way of melting. By the storm's final exit, the impacts spanned over a thousand miles with the visible satellite imagery on the morning of Jan. 7 depicting an expanse of snow cover extending from Kansas to the Mid Atlantic.
Impacts:
By the end of the event, impacts from the winter storm spanned close to 1300 miles from west to east with moderate to high impacts felt as far west as central Kansas extending all the way to the shores of southern Delaware. Out in the Plains, the main impacts came in the form of heavy snow totals with ample blowing and drifting as the surface low intensified while situated over Kansas. Totals between 6 to 12 inches were measured across central Kansas with totals between 10 and 20 inches located over northeast Kansas into northwest Missouri, including the metropolitan area of Kansas City where Kansas City International measured 11 inches of wind-driven powder. The 11 inches over 24 hours put the storm in a tie for 2nd place all time for the Kansas City aviation hub, a period of record that has been around since 1972. The heaviest snowfall was located across northeast Kansas where areas near and along I-70 managed to see totals exceeding 15 inches, including a resounding 20.5 inches in the town of Chapman, confirmed by relevant CoCoRaHS and spotter reports, setting a new record for the area with records dating back as far as 1904. Significant snow totals between 6 to 12 inches continued across northern Missouri into portions of south-central Illinois through the central Ohio Valley spanning portions of Indiana and Ohio.
Severe ice accumulations were found just south of the heavy snow axis within the Mid-Mississippi and Ohio Valleys with totals between one-half to three quarters of an inch of freezing rain located across much of southern Illinois/Indiana and along the Ohio River basin in Kentucky. Areas hardest hit by ice were subject to widespread power outages and damage to area trees and infrastructure due to the weight of the ice. Places within southern Illinois and Indiana were without power for several days following the event due to the toppling of trees and powerlines that made recovery efforts significantly harder to overcome. Lighter ice accumulations below one-half an inch fell over central Missouri and Kentucky creating treacherous driving conditions and several road closures during the height of the storm. Hundreds of thousands of residents within the path of the ice in the Mississippi and Ohio Valleys lost power with several million more generally unable to travel due to the ice coverage across the region. This halted commerce for multiple days sending a shockwave through the commercial shipping industry as delays in shipments via trucking existed until after areas could thaw out in wake of the ice and snow.
Farther east into the Blue Ridge to the east coast, millions were subject to similar issues. Areas on the east side of the Appalachian Front across southern and southwest Virginia and West Virginia received a mixture of ice and snow with ice accumulations bordering one-half to three quarters of an inch over the southern portion of the Blue Ridge. Heavy snow was the most impactful weather farther north with totals of 6 to 12 inches a common occurrence over Northern Virginia, DC, and areas south of I-70 within the state of Maryland. The corridor of heaviest snowfall bisected the district with 8+ inches of snow seen within the urban center and points east, all the way to the Atlantic coast. The highest totals fell over Northern Virginia just south of the Potomac through the southern Delmarva where 10 to 15 inch accumulations were very common as waves of heavy snow impacted the region west to east during the height of the storm. Travel was highly impacted regionwide on the 6th due to the heavy accumulations with many thoroughfares becoming nearly impossible to maneuver after the initial burst during the overnight and morning hours leading into Jan. 6. Flights out of the three major airports based within the DC/Baltimore area were heavily delayed or canceled due to the storm leaving tens of thousands of travelers stranded at the airport or subject to stay in the region while dealing with rebooking flights to continue their travels. In total, over one thousand flights were delayed or canceled within the 3 major Mid Atlantic hubs between the evening of the 5th through the 6th with over a thousand more flights impacted spanning all the airports between Kansas City to Charleston, WV through January 5-6.
Multiple casualties (10) sadly occurred as a result of the winter storm as reported via various major media outlets. Several fatalities were a result of automobile incidents that occurred during the storm in some capacity. Over three hundred thousand total residents lost power across 7 states. Six states saw at least one storm snowfall total exceeding 12 inches with the highest totals located across northeast Kansas, southern Maryland, and southern Delaware. More than 100 million people saw impacts in some way during the storm's life span, a testament to the size and scope of what will be one of the most impactful winter storms of the 2024-25 season.
