Happy Monday! Probably shouldn't be that excited about it, except that I know it's going to warm up a little bit today.
Early morning, expect low clouds, fog, drizzle, mist....this is typical under high pressure when there is ample residual moisture from rainfall like the region has had the past few days (at least most places have...I might still have to water the lawn here in Del Rio...we only got about a half inch in town over the weekend).
As the sun rises, the low clouds will burn off, making way for a nice day with a little sunshine and light winds. Highs in the 60's, lows in the high 30's to low 40's (normal for this time of year)....under scattered clouds....and this will be the main story for the week! Enjoy!
pV = nRT
That's it! Let me explain, and then the attached actual weather chart from 5pm CST this evening will make all the sense in the world.
To not put you through the torture of deriving the equation, it can be simplified as simply saying:
Air Density = Air Pressure ÷ Air Temperature
All this states is that Temperature effects Pressure and Density. If the temperature changes, the pressure changes and the density (the weight of the atmosphere) changes. Likewise, if the pressure changes, so must the temperature and the density.
The first thing we all learned in science back in elementary school is that warm air rises and cold air sinks. If there is cold air at the surface (like in Wyoming and Idaho right now), then the air in the atmosphere sinks. As it sinks, more air fills in the gap. This causes more molecules to fill in, thus making the atmosphere "heavier" (i.e. more dense). The heavier (or more dense) the atmosphere, the more pressure at the earth's surface. That's why there's always a big blue "H" on the surface weather chart somewhere near the coldest place that day.
Since the earth is constantly trying to fall into equilibrium (just like when you pour hot water into cold water and they make luke-warm water), these pressure differences cause what is known as the "Pressure Gradient Force". Now this is a different physics equation, but all you really need to know is that it causes the wind to blow. ...which in return starts moving all the other pieces of weather phenomena.
Weather = Sun Heats Earth Unevenly= Pressure Changes Unevenly = Uneven Pressures Try To Equalize
Good Morning- The gloominess continues today through much of the region as moisture continues to pump into the region courtesy of former Hurricane Sandra. No significant rainfall is expected, but some areas may see about a half inch the through the day- mostly in Hill Country where higher terrain is providing enough lift to produce rain showers. Elsewhere, morning fog and drizzle is the story as the sun rises.
Into the early week, we will flirt with a little bit of blue sky on Monday and Tuesday, but widespread mostly cloudy condition, some slight chances of light rain on Wednesday to some parts of the region with a cold front, and high temperatures in the 60's, with lows in the upper 30's to low 40's (standard for this time of year).
Good Morning! Definitely a brisk one out there. It's amazing how quickly weather can change. I was out running yesterday mid-day and it was real warm and muggy...now it's bitter cold out there.
No better news today, unfortunately....this will be the coldest day yet this season...some places will be lucky to even hit 40*F today in Hill Country. In fact, many areas, primarily above 2000 feet in elevation, may see some sleet this morning. Sleet, for those of y'all who don't know, is rain that has refrozen before it hits the ground (ice pellets). Different from hail or freezing rain, but that's a lesson for another day. The Abilene area has been reporting freezing rain (liquid rain that hits the ground and then freezes) all morning so far- this makes for icy roads and sidewalks...it can be very dangerous. So, if you are driving the Interstate 10 today (or the Interstate 20), or any of the highways headed through Hill Country, be very careful, especially on bridges.
Looks like the rain (and all that other wintry mix) will begin to clear out tomorrow (Sunday) afternoon, leaving the area feeling crisp, but warming up a little bit (into the 50's & 60's by Tuesday). I don't expect a lot of blue sky, but a little here and there is possible, and I would welcome it! Looks like it could get a little gloomy again during the latter half of the week...
*Update to Friday Forecast*
Most of us have felt the power of the cold front pushing through this afternoon...in Del Rio, the temperature dropped from 75*F to 57*F in one hour! And it continues to drop.
Temperatures are already near the freezing mark further north in San Angelo, as well as out west in higher elevation like Fort Stockton and the Alpine - Fort Davis - Marfa region.
Winter-type weather could occur overnight in these areas...primarily freezing rain (better known as ice storm) and ice accumulation on roadways and sidewalks. Areas of greatest concern will be elevations of about 3000 feet as well as all cities north of a line from Odessa to San Angelo, despite elevation.
Additionally, frigid wind chill temperatures will likely be in the 20's widespread through the evening and early morning, with some areas reaching down into the teens, with wind chill.
Be safe and bundle up!
Dan Schreiber is an operational meteorologist, with experience