| February 12 2025 |
Central Plains to Northeast Winter Storm: (2/11 - 2/13)
By: Cody Snell, WPC Meteorologist
Meteorological Overview:
The next in what was an active series of February winter weather came as an impactful winter storm with a swath of moderate to locally heavy snow stretching from the central Plains to the Northeast. The upper-level pattern for the timeframe of this storm (February 11-13) featured a deepening longwave trough over the Rockies as a result of a shortwave dropping southward from British Columbia and interacting with a separate shortwave entering southern California. The system began to mature on February 12 as the upper trough took on a neutral then negative tilt over the central United States and created sufficient upper divergence for a rather widespread precipitation shield. Additionally, the prior zonal flow across CONUS had allowed for ample Pacific moisture to overrun the Southern Tier thanks to a continuous 125 kt 250 mb jet stream which stretched from the northern Baja to the Mid-Atlantic. Then, as the upper flow became more amplified by 2/12, this residual moisture combined with southerly flow out of the Gulf of America to increase precipitable water values to exceed CFSR climatology for the 3-week time period centered on 2/12 per the NAEFS across the Southeast and southern Appalachians, with some of this anomalous moisture also extending northward into where heavy snow occurred in Maine. The continuous moisture fetch into the southern Appalachians was also associated with an extended period of freezing rain which began before this winter storm.
At the surface, a large high pressure system with an estimated central pressure of 1037 mb was analyzed over the northern Plains on 12z 2/11. While this high pressure would weaken over the next several days it remained solidly entrenched across the Northern Tier during the event while a separate area of high pressure developed over northern Maine by 2/13. This led to very cold temperatures across the central and northern Plains as well as Upper Midwest and Great Lakes during the event, with surface temperatures in the single digits and teens for areas that experienced the heaviest snow. Meanwhile, a surface low associated with this winter storm did not organize until the evening of 2/12 through the morning hours of 2/13 and tracked from western Kentucky towards Lake Erie. This placed the low well east of the axis of heaviest snow throughout the Upper Midwest (about 350 miles), with the heavy snow across northern Maine more related to the 997 mb surface cyclone analyzed off southeast Maine by 00z 2/14.
In terms of actual areas of wintry precipitation and the forecasting challenges, this storm brought snow and/or freezing rain from the central Plains to Great Lakes, northern New England, as well as continuing a severe ice storm over the southern/central Appalachians. One interesting aspect of this winter storm was the character of moderate to heavy snow across the central Plains and Upper Midwest. Since this area was so far displaced from any surface features, mid-level frontogenesis played the primary role in creating southwest-northeast oriented snowbands from Kansas/Nebraska to Iowa, southern Wisconsin, to Michigan. This mid-level frontogenesis also overlapped with a very deep dendritic growth zone to produce snow-to-liquid ratios over 20:1 for several locations, which made for heavy snowfall amounts possible within areas of generally light liquid-equivalent precipitation. Forecasts from day 7 to day 1 depicted a northern trend in guidance as medium range (days 4-7) forecasts highlighted the main axis of snow/sleet from central Missouri to the Lower Great Lakes, which ended up 100-200 miles too far south. Even into the short range (days 1-3) guidance struggled to highlight a dry slot that would eventually cut down on heavy snowfall totals around the Chicago metropolitan area.
Impacts:
Snowfall totals from this system resulted in a general 4 to 8 inches from the central Plains to the Lower Peninsula of Michigan, with the heaviest axis and maximum observations of up to a foot of snow recorded between an area from southern Iowa to northwest Illinois and southern Wisconsin. Specifically, 11.7 inches of snow was recorded in Lowden, Iowa and 11 inches in Freeport, Illinois. The major cities for the most part missed out on the heaviest snow, with Des Moines, IA, Milwaukee, WI and Lansing, MI all seeing 6 to 8 inches. Still, numerous impacts were reported due to the moderate snowfall as hundreds of flights were canceled or delayed for airports in Chicago and St.Louis, as well as several automobile accidents across the region. One reported fatality occurred about 100 miles west of St.Louis as officials warned drivers to stay off the roads. The governors of Kansas and Missouri declared state of emergencies for the storm and schools were closed for the major populations of Kansas City, Des Moines, and Omaha. Up to a foot of snow also fell across northern Maine before the storm departed the evening of February 13th, with 10 inches falling in Caribou.
A narrow corridor of freezing rain and/or sleet occurred from central Oklahoma to northern Ohio during the event, with up to 0.6 inches of sleet recorded in Glencoe, OK and 0.25 inches of freezing rain in Fremont, OH. Additionally, as moisture streamed up the East Coast a light wintry mix transitioned to rain across the Mid-Atlantic and Northeast, with lingering freezing rain compounding impacts from a close prior system throughout the central and southern Appalachians.
