4. Forecast Applications

Winter Weather » Precipitation Type 0000 UTC Day 1 (Hour 0)

Hypothetical sounding for precipitation type forecasting exercise, step 1

This sounding shows a relatively warm (T > 0°C) layer extending from the surface at 1000 hPa up to 733 hPa. A nearly isothermal layer exists between 950 and 800 hPa. Winds near the surface are from the NE, veering across the warm frontal zone to ESE at 850 hPa, and to SW above the isothermal layer. The surface temperature/dewpoint is +4.7°C / -10.0°C, yielding a wet-bulb temperature of 0°C and a relative humidity of 34%, and the sounding is unsaturated throughout. The 1000-500 hPa thickness is 5449 m.

Task 1: Predict what type of precipitation will be falling 12 hours from now. (To assist with this question and others that follow, you can open the Interactive Skew-T with this sounding).

Assuming that the combined effects of temperature advection and vertical motion will have negligible impacts on the sounding, which of the following parameters might be useful in assessing precipitation type? (Choose all that apply, then click Done.)