Bulletin: November 18 Data Updates

Updated Terminal Procedures for Massachusetts and Michigan are now available to download for the November 10, 2016 – December 8, 2016 period. These updates address FAA Safety Alerts 16-17 and 16-18.

Updated versions of the Aeronautical Information Manual, Aviation Weather Services (AC 00-45H), and the Pilot/Controller Glossary are also available inside our Documents Catalog.

All customers will be prompted to download these updates inside of ForeFlight Mobile.

New Caribbean VFR Charts Available in ForeFlight

Two new Caribbean VFR sectional charts, recently published by the FAA, are now available in ForeFlight. The Caribbean 1 and Caribbean 2 charts cover the Caribbean and the Bahamas and replace the World Aeronautical Charts (WACs) that cover this region. In case you missed it, the FAA is in the process of phasing out WACs.

US VFR Caribbean chart

View the new Caribbean 1 and Caribbean 2 charts in the U.S. VFR sectional map layer.

You can view the new charts in the U.S. VFR sectional map layer, and they are available to download by anyone with a ForeFlight subscription that includes the U.S. geographic region. You can download them by enabling the switch for VFR Charts and selecting Florida and Puerto Rico in the United States download settings.

The WACs covering the Caribbean will be available in ForeFlight until they expire: CJ-26 expires on February 1, 2018 and CJ-27 expires on March 29, 2018. After these dates, the charts will no longer be available for download in the app.

Aging Surface Observations

One of the more common concerns raised by ForeFlight customers is the age of surface observations or METARs shown within the app. They often wonder why the age of a METAR can be 60 or more minutes old in some cases. To understand why this occurs, let’s discuss how routine surface observations are taken throughout the world.

metar-age

The age shown here in the airport popover is based solely on the difference between the current time and the time the METAR was issued.

If you visit most any airport in the U.S., you’ll likely see one of two weather observing systems installed: the Automated Surface Observing System (ASOS) or the Automated Weather Observing System (AWOS). Both of these are capable of generating one or more weather reports each hour. Although these systems observe the weather nearly continuously in time, they will only generate official reports known as an aviation routine weather report or METAR when certain conditions apply.

Routine observations

For an ASOS, only one routine report is issued every hour, which is a key reason for the seemingly excessive age of these observations. If you pay close attention to the issuance time on METARs, you will notice that many routine observations are issued a few minutes before the top of each hour. Starting at 47:20 past the hour, the ASOS begins to make its routine observation. By 53:20, the hourly observation has been prepared and edited and should be ready for transmission. This routine report becomes the official hourly observation for the NWS. That’s the METAR you will see in the ForeFlight Mobile app.

It’s important to understand that the age presented in ForeFlight is based on the issuance time in the METAR regardless of when it was disseminated by the ASOS or AWOS station. Once each minute we pull down those latest observations directly from our interface with NOAA, parse them and add them directly into our database. After the METAR was issued, it is not unusual for several minutes to pass before it becomes available to ForeFlight. ForeFlight doesn’t typically receive and ingest the data until 4 or 5 minutes after this issuance time. Therefore, it’s very common that the routine observations will have an age of 4 or 5 minutes when updated. That means it’s quite normal to see an age of 64 or 65 minutes just before it gets refreshed by the latest hourly observation.

metar-refreshed

When a METAR is refreshed in ForeFlight Mobile an age of 4, 5 or 6 minutes is very common. For example, this METAR for Ellington, the METAR was updated 6 minutes ago.

An AWOS, on the other hand, typically issues three routine observations each hour or every 20 minutes. The typical interval is at 15, 35 and 55 minutes past each hour. However, you will find that these times will vary depending on the location. You may even run across some AWOS stations that operate similar to an ASOS, that is, one routine observation an hour.

SPECIs

If the weather is changing rapidly for the better or worse, special observations (SPECIs) are issued in addition to the routine hourly observations and include operationally significant changes to elements like wind direction, wind speed, ceiling height and visibility just to name a few. Given that the ASOS relentlessly measures the weather and could inundate pilots with more frequent special observations than a human observer, the system is purposely throttled to provide SPECIs only at 5-minute intervals. This is to limit the number of observations that can be transmitted during the hour when the weather is changing rapidly. Like the routine observations, SPECIs will also take several minutes to appear in ForeFlight after it is issued.

1-minute weather

Before you depart or when you approach an airport, it’s common to listen to the local weather broadcast over the dedicated ground-to-air frequency. This broadcast is referred to as the 1-minute weather. You can also get the latest weather by calling the stations dedicated telephone number. In either case, this automated weather is often more up to date than what you’d get over ATIS or via ForeFlight. At the moment, ForeFlight only provides the latest official observations that are disseminated in the form of a METAR or SPECI. In other words, we don’t currently provide the 1-minute weather you’d get over the phone or on the radio broadcast.

airport-wx-freq

You can find the frequency and phone number for the local ASOS or AWOS on the Airports view under Weather and Advisory tab.

Of course, all pilots want the latest and greatest information. However, that does not necessarily mean an hourly observation that’s 30 or more minutes old should be considered stale. In fact, if the weather hasn’t undergone an operationally significant change, the latest observation is likely still very representative of the weather at the airport.

Range of usefulness

You can’t talk about age unless you also wrap in a discussion about the range of usefulness of an observation. It’s not unusual for many pilots to assume that a particular observation is useful as far as 20 or more miles from the airport. That may be the case when the weather is fairly homogeneous across a large region. But in most situations, making that assumption can get you into trouble.

These official surface observations are taken to be representative of the weather within the terminal area. The terminal area is defined as the circular region within 5 statute miles from the center of the airport’s runway complex. In other words, they are point observations. Notice in the table below that many of the parameters reported in a METAR are valid only within 1 to 3 miles of the airport. So there are no guarantees that the weather is similar to what’s shown in the observation as you get outside of the terminal area.

table-validity-asos

This table defines the representative range from the airport of the various weather elements provided by the observing system.

So the next time you look at the age of latest surface observation don’t discount its operational value. When the weather isn’t changing all that rapidly, a single update each hour will be the normal case for many reporting stations throughout the world.

Bulletin: November 10 Data Updates

Data updates are now available to download for the November 10, 2016 – December 8, 2016 and November 10, 2016 – January 5, 2017 periods:

  • Airport and Navigation Database
  • ForeFlight Airport Diagrams, including updates to the following airports:
17FL 17N 1B2 1D2 2CN4 2O3
3CK 3GM 3J7 3NJ6 66R 6B0
7TA7 82V 8MN3 C04 C65 CNK4
CYCK CYDC CYET CYHE CYOJ CYPR
CYPS CYQS CYQW CYRC CYRI CYRJ
CYRM CYRV CYSA CYVK CYWL CYXZ
CYYD CZNL D25 D54 D98 E26
EVGA F45 F69 FVHA FZAA GA39
HDAM I35 I40 IA27 KALS KAMA
KANP KANQ KAPV KBGF KBIV KBJI
KGXF KSEQ KSLJ KTKO L05 N98
O26 P14 PABT PAGA PAMY PAOO
PAQT PATQ PGRO PGSN PHJH S27
SEGS SEGU SEMT VOHS X59

From the FAA:

  • VFR Charts and Terminal Area Charts
  • High and Low Enroutes, Area Charts
  • Caribbean High and Low Enroutes, Area Charts
  • Ocean Planning Charts
  • Taxi Diagrams
  • Terminal Procedures
  • Airport/Facility Diagrams
  • Documents

For Canada region customers:

  • Taxi Diagrams
  • Terminal Procedures
  • High and Low Enroutes
  • Canada Flight Supplement
  • Documents

For our Military Flight Bag customers:

  • Georeferenced worldwide D-FLIP Terminal Procedures
  • Georeferenced worldwide D-FLIP Airport Diagrams
  • CSA High and Low Enroutes, Area Charts
  • PAA High and Low Enroutes, Area Charts
  • D-FLIP Publications such as Planning Change Notices, Area Planning Documents,
  • Chart Supplements, Enroute Change Notices, and Terminal Change Notices.
  • Airfield Qualification Program (AQP) diagrams
  • Airfield Suitability and Restrictions Report (Giant Report)
  • Airport/Facility Directory

All customers will be prompted to download these updates inside of ForeFlight Mobile.

Don’t Let Satellite Weather Get You Down

The radar depictions you see from the SiriusXM broadcast are highly filtered to provide only real precipitation areas. Ground clutter, anomalous propagation, birds, insects and such are carefully removed to provide the cleanest and most representative image. But like any process, there will be times where non-precipitation returns do not get filtered out. More importantly, you may see real areas of precipitation filtered out as well.

While rare, the latter usually occurs in regions where WSI (the weather provider for SiriusXM) implements what is called a manual gross filter. This kind of filter is the most efficient way to eliminate any clutter in large areas that are not expected to see precipitation. But when that filter is left on too long, it’ll be just as efficient at removing real precipitation from the broadcast.

zoomed-in-gross-filter

Lightning and a single hail storm attribute marker with no radar depicted.

Here’s one such example depicted above. While connected to the SXAR1 I panned the map over Texas and I saw some lightning and a lone hail attribute marker showing echo tops at 45,000 feet in north-central Texas, but no radar returns. Hmmm?

I verified that I had the Radar Composite turned on (I did) and zoomed the display out as shown below to see that there are plenty of other precipitation areas shown to the northeast and southeast of this area. Given that the area wasn’t cross-hatched with “Radar not available” why wasn’t there any precipitation shown?

texas-gross-filter

Zoomed out to show the presence of other precipitation on the radar composite.

About 15 minutes later I came back to the map to see if there was any change. Notice below that plenty of lightning and storm attributes are being depicted here in north-central Texas; however, there are still no radar returns being rendered. Given this activity, you’d expect there to be some precipitation shown when both lightning and storm tracks are present. This is a classic indication that the real precipitation in this region was being erroneously filtered.

gross-filter

This is a classic signature for a gross filter being left on too long. With the radar composite on, no precipitation is being shown despite the presence of lightning and storm tracks.

Just five minutes later, the gross filter was removed by WSI and the returns suddenly popped into existence as you can see below.

gross-filter-pulled

Once the gross filter was removed, the NEXRAD returns associated with these thunderstorms were rendered.

I took a look at the NEXRAD archives and discovered that the first precipitation developed in this region around 12:05 p.m. CDT. The gross filter wasn’t removed until 12:50 p.m. CDT. That’s 45 minutes with no radar for this area of rapidly developing and potentially severe thunderstorms. Moral of the story is to always have lightning ON and be sure the SiriusXM Storm Markers are also set to ON in the Maps Settings menu (the gear button on the Maps view). Having both of these layers on will likely expose these kinds of uncommon events.

Apple iOS 10.1 and ForeFlight

UPDATE: ForeFlight 8.1.1 is all-clear to use with iOS 10.1.1

UPDATE October 28, 2016: Compatibility testing between ForeFlight Mobile 8.1.1 and iOS 10.1 is complete and we are issuing the “all-clear” to ForeFlight customers. Feel free to upgrade at your convenience.

ORIGINAL POST October 24, 2016: We are performing compatibility testing between ForeFlight and the newly released iOS 10.1 to ensure that everything is working smoothly. We will update this post with an “all-clear” when testing is completed.

Bulletin: October 24 Data Updates

An updated Airport and Nav Database is available to download for the October 13, 2016 – November 10, 2016 period. This update includes corrections to geo-referencing information for a few plates and diagrams as well as a small number of airspace corrections.

All customers will be prompted to download these updates inside of ForeFlight Mobile.

Bulletin: Military Flight Bag Oct 16 Data Updates

Data updates are now available to download for our Military Flight Bag users for the October 13, 2016 – November 10, 2016 period:

  • Airport and Nav Database
  • Taxi Diagrams
  • Terminal Procedures

These updates include the latest Airfield Suitability and Restrictions Reports (Giant Reports). All Military Flight Bag customers will be prompted to download these updates inside of ForeFlight Mobile.

ForeFlight Documents Deliver FAR More Value To Flight Departments

ForeFlight’s built-in Documents catalog provides you with our complete library of always-current ForeFlight user guides, as well as an extensive library of up-to-date publications issued by the FAA. Chart supplements and legends, FAA handbooks, and Federal Aviation Regulations are all at your fingertips and included with your ForeFlight subscription. We recently expanded ForeFlight Documents to include more FARs that your flight crews will find as useful references:

  • FAR Part 119 Certification: Air Carriers and Commercial Operators
  • FAR Part 120 Drug & Alcohol Testing Program
  • CFR 49 Part 175 Carriage by Aircraft and Hazardous Materials 

2016-10_docs_blog

“Having the FAA documents right in the app is very convenient. Plus the ability to text search, annotate and add personal bookmarks makes it easy to use. Also very important to us is the automatic updating of the documents. It takes away a lot of stress monitoring the FAA documents for currency.” –Daniel Thornton, Millbrook Aviation

These additions join our comprehensive list of FARs already in the Documents catalog, including:

  • Part 23 – Airworthiness Standards
  • Part 43 – Maintenance
  • Part 91 – General Operating and Flight Rules
  • Part 121 – Operating Requirements
  • Part 135 – Operating Requirements

ForeFlight’s Business Pro plan for flight departments includes the built-in Documents catalog, as well as the ability to add secure cloud-based document distribution of your company pubs. ForeFlight Cloud Documents gives you a fast, easy, affordable way to distribute company documents to every flight crew member. Your administrator can control the distribution of every new or revised flight manual, operating handbook, or special procedures to every pilot’s iPad delivered from the cloud of your choice: Dropbox, Box, or Amazon S3.

Learn more about ForeFlight for Business Aviation here: foreflight.com/business

If you are interested in making ForeFlight a part of your Electronic Flight Bag program, we’d love to chat! Contact sales@foreflight.com or visit foreflight.com/approved.

Why Use Convective Outlooks?

Perhaps one of the most underutilized weather products shown on the ForeFlight Map view are the yellow-shaded polygons called convective outlooks. On any given eight-hour shift, they are issued hourly by a highly trained meteorologist at the Aviation Weather Center (AWC) in Kansas City. In fact, convective SIGMETs shown by a red-shaded polygon are also issued by this same forecaster.

wst-outlooks

Convective outlooks, shown in yellow, can be displayed by picking the AIR/SIGMET/CWAs menu selection. Tapping on the TS button will display all convective SIGMETs as well as any convective outlooks.

Let’s start with convective SIGMETs

Convective SIGMETs (WSTs) define regions of airspace with active areas of thunderstorms that meet specific criteria. The important word here is active. In other words, convective SIGMETs represent more of a NOWcast for thunderstorms than a forecast. Here’s the way it works. Each and every hour the convective SIGMET forecaster at the AWC looks for thunderstorms throughout the lower 48 United States and coastal waters that meet specific criteria. A single cell pulse thunderstorm isn’t necessarily hazardous as long as you don’t fly through the same airspace that it occupies. However, when thunderstorms form long lines, are clustered close together in widespread areas, are embedded or severe, they become more of a threat to aviation and the forecaster will issue a convective SIGMET for those areas of thunderstorms at 55 minutes past each hour.

wst-siriusxm

A convective SIGMET outlined in red for a line of embedded thunderstorms as depicted from the SiriusXM satellite weather broadcast.

Despite the fact that convective SIGMETs are valid for two hours when issued, the following hour the forecaster will once again evaluate the convective threat and issue a new round of convective SIGMETs. Each new issuance at 55 minutes past the hour will supersede the previous set of convective SIGMETs. Effectively, no convective SIGMET will ever exist for two hours.

This is not to say that you must fly around convective SIGMET areas. For a convective SIGMET to be issued, the area of convection must contain significant radar echoes that fill a minimum of 40% of the area at least 3,000 square miles or 40% of a line of at least 60 miles in length. This leaves a fair amount of airspace to navigate through some convective SIGMET areas.

What about convective outlooks?

First, they are not “outlook SIGMETs” as I’ve seen them called. In fact, they are not SIGMETs at all. Unlike convective SIGMETs, convective outlooks are truly forecasts; there isn’t a requirement that active thunderstorms exist when they are issued. Instead, they define larger regions of airspace that are expected to contain thunderstorms that meet convective SIGMET criteria in the next two to six hours after the outlook was issued. These may include ongoing areas or lines of convection covered by a convective SIGMET or they may include new areas or lines of thunderstorms that are expected to develop and reach convective SIGMET criteria in the two to six hours valid period.

wst-outlook

A convective outlook is outlined in yellow. This shows the region where convective SIGMETs are likely to be issued within the next two to six hours. The text of the outlook provides the effective time.

That two to six hour window is a perfect “sweet spot” for many of us making flights. There may not be any thunderstorms when you go to depart, but if your proposed route takes you through one of these convective outlook areas in the valid time specified you may see one or more convective SIGMETs issued within this outlook area during your flight.

outlook-with-cwa

When convection doesn’t quite meet convective SIGMET criteria you may still see a Center Weather Advisory (CWA) issued for thunderstorms as shown in this image. CWAs are issued by meteorologists at the Center Weather Service Units and coordinated with forecasters at the Aviation Weather Center.

What about ADS-B or SiriusXM?

At the moment, convective outlooks are not broadcast over the ADS-B ground stations and are not part of the SiriusXM satellite weather broadcast. In ForeFlight, we attempt to preserve the latest convective outlooks until they expire six hours later. So be sure to use the Pack feature of ForeFlight prior to departure.