This is the second installment of Captain Ray Stark's springtime trip report. To read the first installment, click here. (To enlarge the photos, click on the picture.)
Day Two: Three Legs To Louisville
On this day we are blessed with a nifty 737-700. The 700 can fly higher and faster than the older 737-300 and 500 models. Today, both of these attributes will be handy to have in our bag of tricks. The line of weather we will face is clear of one of our destinations but skirting the first two.
The weather map with which we are greeted shows weather between us and Houston (HOU). As you can see, the tops of some of these storms already reach into the 48,000 foot range and that is only about an hour after the sun has risen over Texas. And, you can see by the arrows indicating the direction of movement, these tall storms will be trying to cross our path enroute to HOU.
Isolated thunderstorms are pretty easy. They are the tallest variety and show up well on radar. Like trees in your path, you simply go around them. Embedded thunderstorms are a little trickier. Moisture attenuates (weakens) the radar signal going out and coming back to the antenna. That means your ability to discern details in what lays ahead is somewhat harder than when you can paint a crisp image of the thunderstorm on your radar and then back up what you see on the scope by looking out the front window. And, in the Boeing 737-700, the weather radar display overlays on your moving map which shows your route of flight. That makes weather avoidance really easy.
Today we are fortunate. The large isolated storms to our south are out of our way. The embedded system to the north of our route is just barely out of our
planned route. We end up deviating off the flight planned path for about ten minutes and are then cleared directly to San Antonio to start the arrival into HOU. As we pass the huge weather mass to our left, the Air Traffic Control (ATC) Center frequency we are working on at the time is Ft. Worth Center. We advise them of what we are looking at knowing full well we both know that system is headed their way. The Weather Channel is forecasting one to one and one-half inches of rain later that evening which will most likely cause flooding. We mention to ATC the 90 degree difference between the jet stream at 109 knots and the lower level winds moving northeasterly at 40 knots. Another perfect recipe for tornados. When we switch to Houston Center, we wish the Ft. Worth controller "Good luck tonight." He responds sincerely, "Thanks."
As we approach San Antonio, we see two small-diameter storms right over the city. Our route of flight will take us between them but the fit is a little tight for comfort so we ask and are granted clearance to deviate to the south around the two. Also, I call the Flight Attendants and get them busy picking up the cabin because the reports by ATC are that the ride is very bumpy in the latter stages of the descent. Passing these two storms, we are glad we sat everyone down because the ride gets pretty choppy and remains that way until about 12,000 feet. We land in Houston under overcast clouds and pick up the runway three miles out at 1000 feet.
Day 2: Leg 2 Houston to St. Louis
We check the weather picture for St. Louis (STL) and the line appears to be west of the airport and moving northeast. The latest airport weather for STL is partly cloudy with no rain. The radar summary below shows STL in the clear-for the moment.
The climb out of HOU is smooth, unlike the ride on the west side of town. Nearing our cruising altitude, ATC sees a hole in the traffic and sends us direct to the start of the arrival into STL. Also at this time, Scott pulls up the latest weather for STL and this is what we see:
Translation: STL information ZULU indicates winds from 350 degrees at 12 gusting to 16 knots (light winds actually-right down the runway), visibility of one and one-half statute miles, heavy thunderstorms and rain showers (+ TSRA), a few (scattered) clouds at 1,400 feet, overcast above at 4,300 feet above the airport, 17 degrees centigrade (63 degrees F), altimeter 30.21 inches, and we can expect Runway 30R via the ILS (Instrument Landing System) approach. Not the sunny day we had hoped for, but in the two hours it takes us to get there, I am betting it will change. (At least the "+" on the thunderstorm thingie.)
In the last hour prior to our arrival into STL, the ATIS (Automated Terminal Information System-the weather screen displayed earlier as ZULU) changes four times due to rapidly changing weather conditions. Normally, it updates at the top of the hour.
As we start the arrival over Cape Girardeau, Missouri, we can now paint the rain showers on our radar. The tops of the clouds are fairly low, and that is good because that means less likelihood that there are thunderstorms imbedded in the clouds between us and the runway. Also, though the radar indicates plenty of moisture aloft, the moisture does not appear well defined-the main indication of thunderstorm presence. Thunderstorms appear with well-defined contours starting in green bands, turning to yellow, all surrounding a red core (indicating heavy moisture). As you can see in the picture to the right, the radar picture on approach just beyond the airport is red but very blotchy. The little parallel white lines represent the runways at STL, and you can see the 30L in white lettering as well.
We break out and sight the runway about five miles out in light rain. On Tower frequency, we can hear planes being cleared for takeoff with instructions for an immediate left turn to avoid the weather. Our planned departure will take us to the right, but that can change, if need be. After we land and pull into the gate, the rain starts to build as another finger of this storm passes over the airport. As for what we face on our departure, we can only wait and see once we taxi out to the runway and look at what the radar shows.
Day 2: Leg 3 St. Louis to Louisville (The last leg)
Inbound to STL, we extensively painted the weather in the area. Calling "Mom" (Dispatch in Dallas) for their radar feed would yield little information about the rapidly changing conditions on the field in STL. We load up and head out for the runway.
As we are cleared into position on the runway, Tower inquires if we are ready to go. We ask for a minute to look at the radar. Below is what we seeout the window:
The radar summary we have (see below) shows the line has moved over STL but not by much. We should be able to blast east and get out of the weather in minutes. (Take a look at what has happened to the system we passed only a few hours earlier in central Texas!!!)
Tower asks us if we can fly runway heading into the weather, and based on the radar picture we have, which is nearly identical to the arrival picture, we suggest an immediate right turn would be better, but we can coordinate that with Departure ATC. (In an emergency, we can do what we need to do and coordinate with ATC as time permits.) A previous aircraft has departed that direction and has not complained-yet. Cleared for takeoff, we blast into the rain and are surprised by a very smooth ride and no thunderstorms visible ahead on the radar. In a couple of miles, Departure ATC clears us to turn to the southeast toward Louisville (SDF). Passing 20,000 feet, we are out of the weather and in clear air. The ride is still a little choppy downwind of the weather system. Because of the short nature of the flight (35 minutes), I call the Flight Attendants who are seated because of the potentially bumpy departure and cancel cabin service. The FA's will remain seated.
The landing minutes later in SDF is under clear skies and 75 degree temperatures. We give the plane to two Pilots headed toward Tampa, FL.
Off we go to the hotel.