First warning: coldest temperatures of the season, 30 seconds possible in some areas
AUSTIN (KXAN) – So far our coldest temperatures of the season in the Austin area returned on October 18 when Camp Mabry dropped to 49 degrees while the Austin Bergstrom Airport hit 44 degrees.
But after Wednesday’s cold front, we’ll likely see even colder temperatures on Friday morning, marking the coldest morning of the season so far. Currently, the First Warning Weather team is forecasting a low at Camp Mabry near 45 for the morning of October 5. Some models display even colder temperatures than this, with the GRAF model showing some rural areas falling in the 1930s.
What is causing this great change in weather?
A cold front that swept through the region early Wednesday morning continues to bring cold northern air behind it. And if optimal radiative cooling occurs on Friday morning, we could very well see some of the cooler models such as the GRAF check out.
What is radiative cooling?
Radiative cooling takes place at night when infrared radiation, or heat, leaves the Earth’s surface and escapes into space. It’s most effective after a cold front when we have drier conditions, clear skies, and calm winds.
Calm winds prevent the air from mixing. The mixed air displaces the air, making it slightly warmer. Clouds act as a blanket preventing this warm air from leaving the Earth’s surface and therefore keep low temperatures warmer than a night with a clear sky. Some models, such as the GRAF, detect the potential for clear skies on Friday morning and therefore significantly cooler temperatures. It is a possibility and we will continue to update you as we refine our forecast.
However, before we hit our coolest season temperatures on Friday, Thursday afternoon, we will experience the coldest HIGH afternoon temperatures so far this season with an expected high near 57. Crush our current coldest high temperature of 75. This was October 17.
The last time we saw high temperatures in the 1950s was on March 1 when Camp Mabry hit 58 degrees.