1/ PM forecast update thread: The worst of this storm arrives tomorrow AM. The current freezing line as of 2pm is shown below. This will vary some, but is expected to creep southward slightly overnight. Expected low temperatures by Wednesday morning are in the 2nd image. 2/ Isolated areas of drizzle, freezing drizzle, & light rain will continue through this evening. Heavier, more widespread rain, freezing rain, and sleet arrive after midnight and continue through the morning Wednesday. Travel will be difficult to near impossible.

Well, at the risk of sounding like a broken record, no rain is forecast over the next week. And our stubborn high pressure pattern of hot and mostly dry conditions is likely to continue through the first week of August. There will be good news at the end of this thread! 1/ Looking further ahead, the @NWSCPC recently issued the monthly outlook for August, and the bad news continues. As we reach the climatologically hottest time of the year, hotter than normal temperatures are likely and odds lean towards drier than normal conditions as well. 2/

Ten weather and climate myths: 1) Generally speaking, there is no "rain bubble" or artificial barrier around your town preventing storms from impacting you. We are in a drought, so rain is hard to come by, but there is also some inherent randomness to storms in some environments. You may miss out one day when the next town over gets drenched, and vice versa the next. It all typically averages out over time. However, there is a large variability in average annual rainfall across our area, from <20" along the Rio Grande to >40" east of US-77.

We know folks have a lot of fatigue around missing out on significant rainfall. And we know a lot of you think we're crying wolf after last night's bust. But, for a number of reasons, tonight's rain chances are much more of a slam dunk for most areas. Last night, there were no focal points for convective development in our area, and surprise midday showers and weak storms ate up some of the energy available. Overnight, South TX got a lot of the rain we were hoping for.

With this being our first threat for severe weather this season (albeit a low risk) and tomorrow the start of the NWS Spring Safety Campaign we wanted to share a quick tweet thread about Severe Weather Preparedness and other basic information! (1/7)

https://twitter.com/NWSSanAntonio/status/1366121714636255237

First off as we go through March to June you will be seeing more and more of these @NWSSPC Outlook Categories. Today's risk is the lowest: Marginal, or Risk 1 of 5. It means that there may be a few isolated severe storms possible. Check out the graphic for more information! (2/7)

Here's a rundown of all the records we've broken over the past week or so at our four climate sites. Bear with us, because it's a lot! For reference, ATT=Austin City, AUS= Austin Bergstrom, SAT=San Antonio (Airport) and DRT=Del Rio. 1/x Temperatures:

AUS: Feb 12th record low MaxT of 34 (37, 1963)
Feb 13th record low MaxT of 32 (38, 2004)
Feb 14th record low of 14 (24, 1999) and record low MaxT of 31 (33, 1951)
Feb 15th record low of 9 (23, 2007) and record low MaxT of 23 (43, 1951)

2/x

A historic winter weather week continues. Patchy freezing drizzle will redevelop late tonight and could cause some problems on roadways across our northern counties. Saturday afternoon and evening, additional light freezing rain and sleet may exacerbate these issues. 1/x It only gets worse from there. Sunday evening, a wintry mix will develop, and as temperatures plummet a changeover to snow will occur with accumulations expected in many areas. 2/x

We've been busy early in 2020 with upgrades to area radars, but there's another awesome new tool added this year that will improve our observations of the atmosphere: an Automated Radiosonde Observation System (AROS)! 1/5 Meteorologists at 92 locations in the US and its territories and many others worldwide have launched weather balloons twice a day, every day for many decades. Here's one example of how the process typically works, made a while back by @NWSTampaBay: 2/5