Moving Wx Into the 21st Century

July 30, 2014 by Bruce Landsberg

IMG_0016PSsmActually the weather has moved quite nicely into this century on its own accord, but some of our forecasting products have not. For example, the venerable FA—that’s the area forecast. It’s produced by the National Weather Service’s Aviation Weather Center (AWC) in Kansas City and is firmly rooted in the middle of the last century. The FA is supposed to fill in the blanks between all the airports with Terminal Area Forecasts (TAFs). It’s well past time for an upgrade. But you need to VOTE—we’ll get to that.

The area forecast speaks in general terms about what you might encounter in the gibberish of teletype because the number of characters is constrained by some long-ago formatting requirement. (Note—the teletype is unlikely to make a comeback.)

The FA is not very precise and extremely time-consuming for the AWC forecasters to build—something on the nature of several hours per shift. Here’s another bit of aggravating trivia: When you reach the man-made boundary of the FA the weather stops, and the forecaster for the adjacent area has to weigh in—with often a different view. It’s my observation that weather isn’t affected by gerrymandering nearly as much as politics is.

The FAA and NWS want to replace the FA with some newer and more intuitive products.

But wait! How to determine if an alternate airport is required, and how to choose one if there is no TAF for the places in question? A friend writes, “I couldn’t agree more in terms of the report itself being delivered in an outdated format; however, …my concern is not having access to some key pieces of information contained in the Area Forecast within the suggested list of alternatives (e.g., ceiling information, cloud tops, etc.). I also haven’t been able to reconcile how one would meet the alternate airport regulatory requirement for IFR flight if not operating to an airport served by a TAF in the absence of an FA.”

Let’s start with the last part first: FAR 91.169 requires that an alternate airport be designated unless weather conditions are at least at, or better than, the 1-2-3 rule (one hour either side of the ETA, a forecast of at least 2,000’ ceilings and 3 miles visibility) based on “…Appropriate weather reports or weather forecasts, or a combination of them….”

The same wording applies to selecting an alternate, if one is required (the forecast required weather is different: 600’/2sm and 800’/2sm, depending if it’s a precision or non-precision approach).

My interpretation is that there is no requirement for this to be an FA. Between integrating nearby TAFS, airmets, sigmets, pireps, and the prog charts one can determine whether an alternate is required or not.

A quick comparison…

An FA reads like this:

“NRN HLF…BKN090 TOP 120. OVR LAND AREAS VIS 3-5SM BR. 14Z SCT080 BKN CI. 18Z BKN060 TOP FL180. SCT -SHRA. OTLK…VFR SHRA.SRN HLF…BKN100 TOP 150. OCNL VIS 3-5SM BR. 14Z SCT060. 18ZBKN060 TOP FL180. SCT -SHRA/ISOL -TSRA. CB TOP FL320. OTLK…VFRSHRA.”

Note that it doesn’t say anything about IFR.

Here is the graphical airmet for the same time. The time blocks can be selected from the drop down box:

Graphical Airmet

Here is the prog chart showing some MVFR:

Prog chart cropped

This is a regional TAF plot showing everything from LIFR to MVFR in the Michigan area:

TAF cropped

Finally we could get into the forecaster’s mind if desired:

(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)

ISSUED AT 1122 PM EDT TUE JUL 29 2014

NOT TOO MUCH CHANGE IN MY THINKING, EXCEPT I ADDED SOME MVFR MIST IN THE TAFS AROUND SUNRISE AS WINDS ARE LIGHT AND TEMPERATURES SHOULD BE GETTING CLOSE THE DEW POINT. THE SHORTWAVE FROM SOUTHERN CANADA SHOULD BRING A BAND OF CLOUDS THROUGH THE CWA TOWARD MORNING BUT IT WILL NOT LAST LONG…. ONCE THE SECONDARY COLD FRONT COMES THROUGH SKIES SHOULD CLEAR. ONLY A FEW AFTERNOON CUMULUS CLOUDS ARE EXPECTED.

We could then take a look at the specific TAFs if desired, but my interpretation on all this is that VFR flights will have to wait a bit and IFR flights that have destinations in the affected area will need an alternate. None of that detail is picked up on the FA.

Why is it important to save forecasters’ time? After all, they’re on duty anyway. GA needs better forecasts and much better accuracy on the size and depth of airmets and the ability for them to be updated quickly via pireps (that’s our job to provide them). If the forecaster is busy creating the antiquated FA, those higher priority tasks often don’t get done. We get “Cry Wolf” airmets too often and sometimes don’t get warned when the wolf really is there. Think of this as we’re not losing the FA, we are gaining much better products.

The Air Safety Institute participated with an FAA and NWS advisory group to look at improving the overall weather dissemination process—it’s arcane, even boring at times, and absolutely essential. Your input is requested by Monday, August 4—do it now by submitting your comments to: kiley@avmet.com. Comments can be very brief. (If you wish to mail comments, please send them to: Federal Aviation Administration, NextGen Aviation Weather Division (ANG-C6), Attn: Richard Heuwinkel, 800 Independence Avenue, SW , Washington, DC  20591.)

Our view is that the FA has served well and needs to retire!

Bruce Landsberg
President, AOPA Foundation

ASI Online Safety Courses  |  ASI Safety Quiz  |  Support the AOPA Foundation

2 Responses to “Moving Wx Into the 21st Century”

  1. Harold Says:

    All the alternate airport references in this refer to “Airplanes”, Helicopters have similar, but different requirements.

  2. Bruce Landsberg Says:

    Harold…

    You are absolutely right and my apologies for not mentioning. The nice thing about helis is that if it gets really scuzzy yo can land just about anywhere being mindful of wires and other obstacles. That’s comforting.

Leave a Reply

*