Big temp swings… blame the lack of rain!April 22nd, 2012 at 9:44 pm by David Mazza under Weather
What a Sunday most of us experienced! This morning low temps fell down to levels that are typical during the Winter, and afternoon highs today that were more typical of late Spring or early Summer. We fell a few degrees short of the record high this afternoon out at Camp Mabry with our high of 91. We have to go back all the way to last year to find the record for the date at 94 degrees (also set in 2009). When you do the math though, today ended up being a pretty normal day. The morning low was 9 degrees below normal and the afternoon high was 10 above, giving us a average temp for the day 0.5 degrees above normal. Below is a map showing the giant temperature swings across our area from morning lows to afternoon highs today.
A few things helped the temps swing so large today, the biggest being the very warm spring sunshine. Also, we had clear skies, very light winds all day long, and abnormally low humidity in the air. In fact, relative humidity levels fell into the teens into parts of the Hill Country today, and low 20% range elsewhere. I also think our resurgence of dry weather has helped the ground to dry out considerably which is only making matters worse. Its pretty clear if you drive along area highways that we need more rain again. And if you remember when we were in our crazy drought last year, when the ground it hard and bone dry, it heats up very quickly, and cools nicely too. That’s why a desert has huge temperature swings, where tropical locations (like along the coasts) have very small temperature changes during the summer. This year we are still just barely 5″ above normal for rainfall here in Austin, but when you plot out where the rain has fallen, you notice the trend the last few weeks of very dry air. On the chart below, I charted rainfall for every week so far this year as it adds to our total. Every time you see a jump, it means we had a wet week. Notice where the longest stretch of almost flat-lining is.
The past 4 weeks have been abnormally dry across our area even though we have seen a few moderate cold fronts blast through our area. Most of them have been more bark than bite for us, however, the bark has been felt to the south. The coastal sections of Texas have been taking some big hits from these fronts, with severe weather, and heavy rainfall. Our chances of rain look slim to none over the next 7 days with some hope near the end of next weekend Sunday into Monday. The latest Climate Prediction Center forecast for days 8-14 forecasts an above normal chance of seeing wet weather in our area over that time period. It is picking up on a few disturbances kicking across the southern Plains for the start of May. Remember a lot can change between now and that time, so we will be keeping our fingers crossed for that wet forecast for the start of May. I’ll go out and wash the car too
Below is the CPC 8-14 day rainfall forecast.