Wednesday Morning – February 12th, 2025
Campus Weather Forecast 2/12/25 1500Z
Wednesday High: 30 degrees (snow)
Wednesday Low: 10 degrees (cloudy with increased winds)
Thursday High: 24 degrees (partly cloudy and windy)
Thursday Low: 12 degrees (increasing clouds)
Friday High: 38 degrees (mostly cloudy and windy)
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General discussion: The snow we have been receiving Wednesday morning will continue into the afternoon, leaving Wednesday an online school day! Temperatures below freezing will cause the snow to stick around into friday, where temperatures warm up into the mid-upper 30s.
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Forecasters:
Huebner, Nightingale, Chirpich
Snow prevails in the Columbia area throughout the day Wednesday, with expected snowfall amounts of 2-3 inches and temperatures near 30°F.
Decreasing clouds and warming temperatures (40°F) are expected on Friday as winds shift from the northwest to the southwest toward the end of the forecast period.
Discussion
The GFS was used for this forecast because of its accuracy in storm movement and moisture characteristics. A confluent jetstream joins movement from the subtropical jet with cooling effects from the polar jet. At 200 mb a trough is centered northwest of Missouri, allowing for active weather to settle in the forecast region. The associated low is believed to be a Colorado low, which indicates advection of cold, dry air. This will affect snowfall accumulations and surface visibility, which will be discussed further. An upper-level area of convergence passes over Missouri throughout the daytime hours of Wednesday, which will bring delayed divergence to the surface (dry, sinking air causing snow to end this evening). Eventually, the trough will flatten in the morning hours of Thursday (12Z), leaving winds in zonal flow from the West-Southwest. Effects from the polar jet will be seen in the final hours of the forecast period (Friday 18Z), with dry air and clearing conditions.
Mirroring the trough pattern at 200 mb, the GFS on Wednesday at 18Z indicates areas of lift at 500 mb throughout the Midwest. A river of vorticity passes through the Ozark Region in the early afternoon hours on Wednesday (18Z), with a vorticity max centered in the Appalachians. Although the forecast region will not see a local vorticity max, vorticity associated with a shortwave will disrupt the Missouri region at that same time on Wednesday. This may intensify the winter storm with additional forcing as increased lift suspends ice nuclei aloft. On Thursday and Friday, the upper-level flow continues to stack down, leading to zonal flow and decreased lift over the Mississippi River Valley.
At 700 mb, moisture lingers throughout the day on Wednesday, with the greatest increase during the afternoon hours (>90% RH), when the heaviest snow will be seen Dry air passes behind the snowstorm causing partly cloudy conditions and increased winds from the northwest on Thursday as RH values dip to 10%. Moisture returns on Friday and will linger for the remainder of the forecast period with winds shifting to the southwest.
850 mb aligns with 700 mb, specifically in the moisture pattern on Wednesday. The RH over Columbia is expected to remain over 80% until the early morning hours of Thursday (09Z). During this time, winds shift from the southwest to northwest and continue to shift north throughout the end of the day on Thursday. Following the passage of a mid-level low through Nebraska, temperatures are expected to drop on Thursday. As mentioned above, a southwest wind shift will lift temperatures slightly on Friday and add moisture back into the system in the evening hours on Friday.
The main focus of the Wednesday winter storm is the intensity of winds aloft. Soundings at 15Z and 18Z show mid-level winds over 80 knots, which will fracture ice nuclei and inhibit the growth of individual snowflakes. Moisture is evident from 250 mb to the surface, with marginal dry slots lingering around 600 mb. All precipitation is frozen with saturation in the DGZ, which will promote snow production. Due to a temperature profile well below freezing, snowflakes signal a high SLR. So, as accumulation intensifies at 18Z on Wednesday, the snow can be characterized as light, dry, and flaky. Anticipated snowfall amounts on Wednesday range from 2-3 inches. It should be noted that a presence of roughly 15 knot winds paired with a large amount of small snowflakes will reduce surface visibility and can cause hazardous travel conditions.
Huebner, Chirpich
Tuesday Afternoon – February 11th, 2025
Tuesday Night: Cloudy. Low: 25°F
Wednesday: Cloudy snow beginning around 4am to 5am. High: 30°F
Wednesday Night: Cloudy snow stopping 4pm to 5pm. Low: 10°F
Thursday: Mostly Sunny. High: 24°F
Thursday Night: Increasing Clouds. Low: 13°F
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General Discussion:
Our winter storm is on track to blow through the region early in the morning on Wednesday. Snow accumulation is expected to be 3-5”, with the heaviest snow falling around 10am-2pm Wednesday afternoon. Our temperatures will begin a steady descent as the system passes through with high temperatures plummeting nearly 10 degrees below the 44°F average. Lows will plummet even further, flirting with single digits by the end of the week.
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Forecasters: Brucker, Latlip, McCurdy
Date Issued: 11 February 2025 5:40 PM CST
Key Messages:
– A winter storm will move through the forecast area on Wednesday, bringing 3-5” of snow total accumulation.
– Temperatures will plummet with dangerously cold conditions persisting through the end of the week. Wind chills could hover around 0 degrees especially on Thursday.
Technical Discussion
Looking outside today, overcast skies and a few flurries remain as evening approaches. Upper-level water vapor imagery shows the remnants of a shortwave system moving east into the mid-atlantic. 300mb guidance depicts a jet max with enhanced divergence exiting the region as well. Moving forward through tonight, an upper-level longwave trof will eject into the region bringing a strong jet max and enhanced divergence aloft. Deterministic guidance is suggesting a healthy mid-latitude cyclone moving into the region in the early hours on Wednesday morning. Confidence is increasing in a potentially problematic intrusion of dry air interacting with the system during the evening hours of the storm. Current forecast soundings show a relatively isothermal profile around -6°C allowing for decent aggregation of dendrites during the time that heaviest snow is expected to fall. However, this, coupled with winds 10-30 kts in the lower levels will break up the dendrites into smaller ice crystals resulting in SLRs around 12:1-10:1. This has resulted in expected snow totals of 3-5”.
Following the passage of the cyclone, temperatures are expected to plummet with highs in the mid to low 20s and lows in the teens. These dangerously cold temperatures are the result of the cold air mass pulled down from the north by our winter storm. These conditions will be further reinforced as some mild ridging fills in behind the system on Thursday. Future shifts should note a disturbance that currently appears immediately following the passage of this high pressure center, potentially increasing the chances of precipitation approaching the weekend.
Brucker