As winter weather affects North Texas, forecasts for the Dallas–Fort Worth region have repeatedly shifted between sleet and freezing rain, even as surface temperatures remain below freezing.
According to the National Weather Service, these changes do not reflect uncertainty about freezing conditions themselves. Instead, they stem from how small differences in atmospheric conditions above the ground can determine which type of winter precipitation reaches the surface.
How Sleet and Freezing Rain Form
Both sleet and freezing rain begin as snow high in the atmosphere. As the snow falls, it passes through a layer of air above freezing, where it melts into liquid rain.
What happens next depends on the thickness of the freezing air near the surface.
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Freezing rain occurs when the layer of freezing air is very shallow. Raindrops remain liquid as they fall and freeze instantly when they contact roads, trees, power lines, or other surfaces.
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Sleet forms when the freezing air layer is thicker, allowing raindrops enough time to refreeze into ice pellets before reaching the ground.
In both cases, surface temperatures can remain below 32 degrees throughout the event. The determining factor is the depth of cold air above the surface, not the temperature at ground level alone.
A National Weather Service diagram shows how differences in atmospheric temperature layers determine whether winter precipitation falls as snow, sleet, or freezing rain | Image by NOAA/National Weather Service
Why Forecasts Can Shift Even Below Freezing
Winter weather systems in North Texas often involve shallow cold air trapped near the ground while warmer air flows above it. Small changes in wind direction, precipitation intensity, or atmospheric cooling can slightly deepen or thin the freezing layer.
Because the difference between sleet and freezing rain can depend on relatively small changes in the vertical temperature profile, forecast models may alternate between the two outcomes as new data becomes available.
Why Forecast Apps Can Show Freezing Rain Even Near 20 Degrees
An hourly forecast shows precipitation alternating between snow, sleet, wintry mix, and light freezing rain while temperatures remain below freezing, reflecting uncertainty in atmospheric temperature layers above the surface | Screenshot by Weather App
Hourly forecasts may occasionally show brief periods of freezing rain mixed with sleet or snow even when surface temperatures are in the upper teens or low 20s. According to National Weather Service guidance, this can occur when snow melts into rain in a warm layer aloft and then falls through a shallow layer of freezing air near the surface that is not thick enough for the droplets to refreeze before reaching the ground.
Small changes in the depth of that cold layer — sometimes occurring over the course of an hour — can cause forecasts to alternate between sleet, freezing rain, or a general “wintry mix,” even while surface temperatures remain consistently below freezing.
Why the Hazards Are Different
Both sleet and freezing rain can create dangerous conditions, particularly for travel, but they pose different types of risks.
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Sleet typically accumulates as ice pellets on road surfaces, reducing traction and increasing the risk of vehicle crashes, especially on bridges and overpasses, which freeze more quickly than surrounding roads. Sleet is less likely to cause widespread damage to trees or power lines.
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Freezing rain creates a smooth glaze of ice on contact with surfaces. Ice from freezing rain can rapidly add weight to tree branches and power lines, increasing the likelihood of broken limbs, downed lines, and power outages, in addition to hazardous driving conditions.
What Forecasters Are Monitoring
Meteorologists are closely watching:
- The depth of freezing air near the surface
- Temperature changes above ground level
- Overnight cooling, which can deepen cold air
- Ice accumulation potential rather than precipitation totals
In weather setups like this, forecast adjustments reflect how narrow the margin can be between two different winter precipitation types, not disagreement among forecasters or flaws in the models.
