An influx of cold, arctic air will result in a continued extended period of cold air temperatures and bitterly cold Wind Chill values across the local region through Wednesday morning. Some patchy light wintry precipitation is also possible mainly in central/southern parts of the local area on Monday afternoon. Please see below for details on all expected impacts and timing elements.
...Wind Chill Impacts...
Wind Chill values will continue to average the teens to lower 20s through about 10-11am on Wednesday. Within this broad time period, minimum Wind Chill values will average around 10 degrees around sunrise on both Tuesday and Wednesday mornings.
If you must be outside for extended time periods during the above mentioned time period, precautions should continue to be taken to prevent frost bite and/or increased fatigue due to the colder temperatures. We recommend wearing loose fitting clothing in multiple layers, as well as a heavy coat, gloves, scarf and a hat that covers the ears. For maximum protection, a ski mask or other face covering should be used especially if you must be outdoors for greater than 15 minutes at a time during the above mentioned time period, and especially during the periods of minimum Wind Chills noted above.
...Temperature Impacts...
In addition to the concern due to bitterly cold Wind Chills, actual air temperatures will continue to be quite cold during the same time period. Below are the forecast minimum and maximum air temperatures forecast for Today-Wednesday (on average for the local area):
Day: Low/High
Today: 22/31
Tuesday: 20/32
Wednesday: 18/48
Actual air temperatures will remain at or below the freezing mark at most locations through about 10am on Wednesday. This will have been a total of approximately 62-hours with freezing or sub-freezing temperatures (since around 8pm on Sunday at most locations). While it is not unusual for the area to experience freezing or sub-freezing temperatures for at least brief time periods in the winter, it is very unusual for the area to experience freezing or sub-freezing readings for such a long time period (i.e., 60+ hours), which is the reason that we continue to call attention to this particular aspect of the cold air event.
Precautions should continue to be taken to prevent freezing and/or bursting of pipes, particularly in older and/or poorly insulated structures during the above mentioned time period. To mitigate the risk of frozen pipes, we recommend allowing the cold water drip from the faucet served by exposed pipes. Running water through the pipe - even at a trickle - helps prevent pipes from freezing. It is also a good idea to keep the thermostat set to the same temperature both during the day and at night to avoid fluctuations in the air temperature surrounding the exposed pipes.
...Precipitation Impacts...
A weak weather disturbance will continue to track mainly to the South of the local area today, producing a mixture of light freezing rain, sleet and light snow to the south of the local area, including the San Antonio area, for much of the daytime hours today. Caution is advised if travel is required South into that area today.
For the immediate local area...present indications suggest that the Northern edge of the aforementioned area of wintry precipitation may begin to work Northward especially into parts of the local area this afternoon. At this time the most favored area for such a possibility includes most of Hays County and would be from near/shortly after 12 Noon through about 6pm today. Any wintry precipitation by that time would likely be in the form of at least patchy areas of freezing drizzle, ice pellets (sleet) and/or snow flurries.
At this time significant accumulation of wintry precipitation is not expected across the local area this afternoon, due to the expected short duration, light intensity and expected spotty to scattered coverage of the precipitation. With that said, we will continue monitoring precipitation and temperature trends this afternoon and will issue any specific updates if conditions warrant. Out of an abundance of caution, we would advise using care if travel is required especially in more rural areas where roads are less traveled during any periods of light precipitation this afternoon, particularly in southern parts of the local area as described above.
...Recap of Primary Local Concerns...
To recap, the primary local impacts from this event will continue to be the extended period of cold temperatures (including an unusually long period of sub-freezing temperatures) and wind chills. Please continue to take appropriate precautions as noted above to minimize these impacts during the event. We will continue monitoring the expected light wintry precipitation for the afternoon period today and issue updates as conditions warrant.
