Day 4 of San Antonio, TX (KSAT)

Low-level clouds and southerly winds prevented it from getting below 75F last night, with the front stalling just to the northwest, as most models showed. The low-level clouds broke up, leading to a quick warmup to at least 89F this afternoon. There was already at least 21 kt last night, higher than USL. The day 3 low will likely occur tonight as the front finally pushes southeastward. 

 

Day 4 will be another very tricky day. The high will likely occur at the beginning (Saturday 06z) but that is rather uncertain. It is not clear if a subtle mesolow will push the front back northwest of San Antonio briefly later tonight, causing a temperature spike, or if it will stay just to the southeast, leading it to stay cool. There will likely be some showers and possibly a thunderstorm later tonight, though rainfall amounts are unlikely to be heavy as most of the dynamics stay to the north. Also, some clearing will lead to sunshine and a decent warmup tomorrow to near the high at the beginning, even with northerly winds, as the upper-level low with the really cold air aloft and precipitation staying to the northwest, with snow falling in northwestern Texas. Tomorrow night, a subtle secondary cold front from the storm-generated cold air will lead to a quick temperature drop with the low at the end (Sunday 06z), with the maximum winds likely occurring with a wind burst along the secondary front. USL usually does not capture sudden wind spikes associated with fronts, although today, it is still suggesting quite strong winds anyway. The cooldown will be mostly due to cold advection, with the strong winds keeping the boundary layer rather well mixed and preventing much additional radiational cooling despite mostly clear skies, and usually models have a rather good handle on this.

 

Source: PivotalWeather

 

 

Source: PivotalWeather