Another heavy rain event is headed our way. I break it down for you here.

What you need to know about our heavy rain forecast

What you need to know about our heavy rain forecast
National Weather Service Houston

So here we are, another holiday weekend (Mothers Day in case you forgot), staring yet another heavy rain event in the face. Springtime heavy rain events in this area are notoriously difficult to forecast and this week's storm is no different. So while I can't tell you exactly where and how much it will rain in any given spot I do want to take this opportunity to explain the threat in a manner that is hopefully easy to understand.

Why is this all happening?

This afternoon a front is going to drop down through the state and stall over our area. This front will serve as a focusing mechanism for storms over the next few days. It will be both a source of the lift that is needed to form storms as well as a track for atmospheric disturbances – triggering mechanisms – traversing the area. If you walked outside today you undoubtedly noticed the absurd humidity. This is a result of copious amount of moisture being pumped in off the Gulf which is nothing but storm fuel. Beginning late Thursday and continuing through Saturday evening a number of disturbances will be riding along the stalled front triggering storms like pulses of electricity running down a wire, that also happens to have a bottle of lighter fluid pointed at it.

Once storms form they may be in no hurry to move, or may keep building on themselves causing some unlucky spots to be pounded for hours. This is where the flooding issue sets in. Another compounding factor will be that at times the airflow in the upper atmosphere (part of the jet stream) will split off in different directions over the area. This will provide an additional source of lift for the storms and essentially act as an exhaust fan helping to fan the flames. This will only serve to increase the rainmaking ability of the storms.

When is this all going to happen?

The general consensus is that this event will begin late this afternoon or this evening and continue through Saturday evening. It will not rain the entire time but waves of heavy rain and storms will be possible any time during that time frame as those atmospheric disturbances make their way across the area. The best advice would be to stay alert especially if you have plans to be out during that time, especially at night.

How much is it really going to rain?

By now I am sure you have seen on the local weather reports that anywhere between 3 to 5 inches will be common with some spots getting up to 12 inches. While it is true that some spots may indeed only see a couple of inches of rain in this event it is impossible at this time to determine where the rain bulls-eyes will be. Speaking of those bulls-eyes – these type of set ups can very easily over-produce so while the "official forecast" right now calls for high spots of 12 inches I really wouldn't be shocked if a couple of places picked up 15 or maybe even 20 inches of rain before this is all said and done.

The real issue in these situations is really rainfall rates, or how much rain falls per hour. For the most part our streets and drainage systems are designed to handle about 1 to 1.5 inches per hour. However, as we saw on Tuesday these types of storms in an absolutely juiced up atmosphere can produce rainfall rates that far exceed that, sometimes pushing 4 or 5 inches per hour. It is these high rainfall rates that will produce the flooding issues that we see. As I mentioned above there will be breaks in the rain over the next few days, the problem is going to be that most of the 10 inches someone gets may all fall within a 2 or 3 hour span.

Where is the worst going to be?

Unfortunately this is simply impossible to determine right now. Before you get all cranky on meteorologists no being able to get things right let me explain why. Many of the atmospheric features that determine exactly where storms form and produce heavy rain are so small that they cannot be seen until a few hours out, if that. The computer models that are typically used to aid in creating a forecast can only project conditions down to a certain area (their resolution). The models that forecast on a global basis can "see" things down to 6-10 miles wile some higher resolution models can "see" things down to just a couple of miles. So while these models are helpful in showing us the overall set up is ripe for heavy rain they are unable to accurately pick up on boundaries or other triggering mechanisms that may below their resolution. In addition to that, once storms form they create their own environments, often sending out additional boundaries which trigger more storms nearby. This chain reaction effect is also nearly impossible to predict with accuracy. While the science of meteorology is light years ahead of where it was even 10 -15 years ago it still is not perfect.

The key here is to prepare as though you will find yourself in one of these rain bulls-eyes and hope for the best. These areas will be relatively small and probably spread out across the area but it is just impossible to tell right now which neighborhoods will be the ones to get them.

I know heavy rain events cause a lot of anxiety and stress in our post Harvey world, but I want to assure you that there is no indication that this event will be another Harvey. Yes there will likely be street flooding and maybe some structure flooding in places but this will not be a widespread catastrophic event. This type of system is part of the reality of living on the Gulf Coast in a highly urban area. Heavy rainfalls are a fact of life and the best we can do is arm ourselves with the knowledge necessary to be prepared and use our best judgment to stay safe.

P.S. If you do not already, I would highly encourage you to follow the Houston National Weather Service office on whatever social media platforms you like to use. They are an invaluable source of information and are the ones who issue any warnings that may be necessary.


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The Coogs are back in action Friday night. Photo by Ron Jenkins/Getty Images.

Sixteen may be sweet, but it isn’t the only relevant number as the NCAA Tournament heads into the regional semifinals.

Here are some other numbers worth knowing for each team. These statistics will help you learn more about each of the remaining teams and could explain how some of them got this far.

EAST REGION

UCONN: In UConn’s second-round victory over Northwestern, Donovan Clingan became just the third player in tournament history to get 14 points, 14 rebounds and eight blocks in a game. The others to do it were Hakeem Olajuwon for Houston in 1983 and David Robinson for Navy in 1986. The blocks also were the most ever by a UConn player in a tournament game.

SAN DIEGO STATE: The Aztecs’ Sweet 16 matchup with defending national champion UConn will mark the fourth time that two teams have faced each other in the tournament a year after meeting in the final. The losing team from the championship won the rematch in one of the three previous instances, when Duke beat UNLV in a 1991 semifinal. Cincinnati won two straight championship games over Ohio State in 1961-62. Florida beat UCLA in the 2006 championship game and in a 2007 semifinal.

ILLINOIS: Illinois has won six in a row, and Terrence Shannon Jr. has scored at least 25 points in each of those games. The 6-foot-6 guard has averaged 30.5 points and has shot 52.8% (56 of 106) from the floor during that stretch. He also shown an uncanny knack for drawing fouls during the streak. Over his last five games, Shannon has gone 51 of 58 on free-throw attempts.

IOWA STATE: Iowa State is allowing just 61.2 points per game to rank fourth among all Division I teams in scoring defense. Since falling 73-65 to Houston on Feb. 19, the Cyclones haven’t allowed any of their last 10 opponents to exceed 65 points. The Cyclones next face Illinois, which ranks ninth in points per game (84.6) and has averaged 91.3 points over its last four contests.

WEST REGION

ALABAMA: Mark Sears and Aaron Estrada were the first set of Division I teammates since 1996-97 to both have at least 410 points, 125 assists, 120 rebounds, 50 3-point baskets and 40 steals during the regular season. Sears is averaging 21.5 points, 4.2 rebounds, 4.2 assists and 1.7 steals. Estrada has 13.3 points, 5.4 rebounds, 4.7 assists and 1.7 steals per game.

NORTH CAROLINA: Armando Bacot had seven straight tournament double-doubles and six consecutive tourney games with at least 15 rebounds before he ended up with 18 points and seven boards in a second-round victory over Michigan State. His seven straight NCAA double-doubles matched Tim Duncan and Olajuwon for the NCAA record.

ARIZONA: Arizona’s first-round triumph over Long Beach State marked the 19th time this season the Wildcats had five different players score in double figures. No other Division I team had that many games this season in which five different players had at least 10 points.

CLEMSON: Each of Clemson’s first two tournament opponents has shot below 40% against the Tigers. Clemson won its first-round game by limiting New Mexico to 29.7% shooting, the lowest percentage the Tigers had ever allowed in an NCAA tourney game. Clemson now faces Arizona, which shot 52.8% in its second-round victory over Dayton.

MIDWEST REGION

CREIGHTON: Baylor Scheierman is the first Division I men’s player in history to have at least 2,000 career points, 1,000 rebounds, 500 assists and 300 3-point baskets. Scheierman, who is in his second season at Creighton after playing three seasons at South Dakota State, has 2,208 points, 1,250 rebounds, 578 assists and 352 3-pointers.

TENNESSEE: Tennessee is making its 10th Sweet 16 appearance – including its seventh in the last 18 years – but the Volunteers have never reached the Final Four and earned their lone regional final berth in 2010.

GONZAGA: Gonzaga is in the Sweet 16 for the ninth straight time, the longest active streak of any Division I team. Going back to 1975 – the first year that all teams had to win at least one game to reach the Sweet 16 – the record for consecutive Sweet 16 appearances is owned by North Carolina with 13 straight from 1981-93.

PURDUE: Zach Edey is the first player since Kareen Abdul-Jabbar (then known as Lew Alcindor) in 1968 to have at least 50 points and 35 rebounds while shooting 65% from the field in his first two games of an NCAA Tournament. Edey has shot 67.9% (19 of 28) and has totaled 53 points and 35 rebounds in victories over Grambling State and Utah State.

SOUTH REGION

DUKE: Jared McCain has gone 10 of 17 from 3-point range through the first two rounds. In the Blue Devils’ second-round blowout of James Madison, McCain became the first freshman to score at least 30 points without committing a turnover in an NCAA Tournament game since the event expanded to 64 teams in 1985.

HOUSTON: The Cougars showcased their depth by surviving a second-round matchup with Texas A&M in overtime even after four of their five starters fouled out. They became the first team to win an NCAA game while having at least four players foul out since 1987, when UTEP overcame foul trouble to beat Arizona.

MARQUETTE: Marquette owns a 75-29 record under coach Shaka Smart despite posting a negative rebound margin in each of his three seasons. The Golden Eagles have been outrebounded in each of their last eight games but have gone 5-3. They’re getting outrebounded by 3 boards per game this season. The only other Sweet 16 team with a negative rebound margin is North Carolina State (minus-0.8), which faces Marquette on Friday.

NORTH CAROLINA STATE: Mohamed Diarra has 6.4 points and 7.7 rebounds per game this season, but he’s averaged 11.7 points and 13.5 rebounds over his last six. Michael O’Connell scored in double digits three times and totaled 14 3-point baskets in 31 regular-season games. He’s reached double figures in six of seven postseason games and has gone 12 of 22 from 3-point range during that stretch.

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