Learning how to use in-cockpit weather (1): Miles City, MT (KMLS) to North Platte, NE (KLBF)

After about 45 minutes on the ground in Miles City, we fired up JYMmie again, this time headed for North Platte, Nebraska. We were hopeful that we would get to North Platte, as the weather there was steadily improving, but not at all confident of our success. We headed first toward Gillette, keeping an eye on the weather on the GPS.

We have not had in-cockpit weather available to us before. Before our trip, we invested in a Garmin Aera and XMWeather subscription. There is no training available on how to best utilize such a resource, but here are some nuggets we gleaned:

1. Understand the limitations of the information:

By the time the information is displayed, it is always old, sometimes by as much as 20 minutes, or more.

For this reason, one should not use in-cockpit weather (ICW) as a tactical decision-making tool, but rather for strategic planning. One should not use it to decide where to go between two cells of heavy precipitation. Of course, this rule is not rigid, for example where cells are widely spaced and slow-moving, especially if VFR.

Interestingly enough, here is an example that negates the tactical/strategic rule.

On our return from the Bahamas we were dodging rain showers as we approached the Miami coastline. We were VFR, but it was comforting to use the ICW to confirm that the cells were isolated.

About 56 nm miles out of Fort Lauderdale Executive airport, we are just inside the ADIZ. The scale of 20nm seems ideal for making strategic decisions at JYMmie’s airspeed. The stationary front to the south, with its associated weather, is shown. Note that this image was obtained 3 minutes ago. The information could be significantly older than this, however, and there is no way to know exactly how old it is.

The ICW display shows precipitation density, not cloud density. So, although it appears that there were only isolated clouds, in fact there was a complete ceiling, with isolated showers. We have found that we can usually comfortably traverse green areas. The yellow not so much, if we are to remain VFR.

Watching the cells to our left, we were doing well, until Miami Approach called us up, and made suggestions for a heading for us to fly. Remembering the fact that our information is often old, we followed their advice and were turned directly into what showed as an orange return on our display. We flew into fairly heavy rain with reduced visibility as a result. We were just starting to clear the rain, when we were once again vectored into another orange area! A look out the window confirmed what our display was telling us, so we declined the vector, and remained in the clear for the remainder of the leg.

Looking back along the reciprocal of our course after landing. As always, we were reminded that final decisions regarding any flight rest with the pilot, and not with ATC, and that weather is a fickle mistress!

Here, however, is an example of how ICW is helpful for more strategic planning.

Check out the video below (there is no audio). The green line is the heading we are trying to steer. Do we go to the left or the right of the rain cell?

At first glance, it would seem that we would be able to go to the left, the more direct way. However, the ICW NexRad showed us that we would end up in a dead-end of heavy precipitation and need to retrace our route. It also showed us that we had better options to escape worsening weather to our right.

We steered to the right of the cell.

(More on using in-cockpit weather in later entries)

Changing Plans for Weather : From KCTB (Cut Bank, MT) to KMLS (Miles City, MT)

After clearing with customs, we entered the old airport building that brings back memories of times long gone. There are even showers and beds available, should you need them. We always seem to meet interesting traffic at Cut Bank, but today we were the only aircraft on the ramp. The Chinook Arc that had been present when we left Lethbridge was very prominent here, and the winds seemed to be increasing, so we were keen to get going.

Close to the ground, the going was bumpy, due to the high winds. We were seeing great ground speeds, due to the westerly flow over the Rockies behind us.

Just before this trip, we acquired the ability to download live weather updates via satellite into the cockpit (For the pilots reading this, we use a Garmin Aera and XM Weather). We were not sure that the investment would be worth it, but this leg was the first of many that made us grateful for this tool.

Our plan had been to fly to Miles City, MT (KMLS), where we would refuel, then on to Pierre, SD (KPIR), before heading to Lincoln, NE (KLNK) for the night. A low that was blocking our route to the east was expected to move on as the day progressed, but this did not seem to be happening. We would be able to get to Miles City, but not much further, it seemed.

Using our on-board weather, we could evaluate multiple plans and contingencies. We were headed southeast, so if we could not go east, we figured, we may as well go south. Having weather in the cockpit meant we could see beyond the rain showers that were visible ahead, and make informed decisions that improved our ability to continue flying and making progress in our journey.

A very handy tool to complement our weather decisions is a new product from the FAA: a VFR planning map. Covering the entire continental USA on a single sheet at a scale of 1:3,100,000. It worked quite well in the cockpit, once we had it folded sensibly.

Our weather-enabled GPS could tell us where to fly, and perhaps more importantly, where not to go. The planner gave us a quick reference to what airfields, terrain and airspace lay on our new course. We could then use that information to further refine our plan, by using the identifiers to find more weather on the GPS. Voila!

RegularNut was suffering from a bad flu bug. Ear aches and a headache made the first few days of flying uncomfortable for her, and piloting out of the question. She remained an able and very helpful co-pilot despite being unwell. It is always easier with two pilots in the cockpit, even if one of them is under the weather!

By the time we landed at Miles City, we had our new plan well formulated, and I went into the FBO with the portable GPS already loaded with our new route.

It was as well, as the FBO had no Internet connection, only a tired telephone with which to call Flight Services. The lady behind the counter gave me a funny look when I explained that we had pulled up at the self-service fuel, but then taxied over to the FBO when we saw there was one, as we try to always support local business. She told us that they owned the self-serve as well. I was not willing to taxi back to the self-serve bowser, so I asked her to top JYMmie off, although it seemed we were imposing somehow.

Fortunately, all I had to do was make the call, ask about TFRs, Notams, and file a flight plan, while RegularNut settled the fuel bill, and we were ready to go.

On our return flight, we were happy to be able to overfly Miles City for Lewistown, which is a very friendly little airport.

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