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April 11, 2016

New forecast software is allowing the National Weather Service to break out of the days when weather reports were sent by “the wire” over teleprinters, which were basically typewriters hooked up to telephone lines. Teleprinters only allowed the use of upper-case letters, and while the hardware and software used for weather forecasting has advanced over the last century, this holdover was carried into modern times since some customers still used old equipment.

Better late than never, but the slow change was not for lack of trying. The National Weather Service has proposed to use mixed-case letters several times since the 1990s, when widespread use of the Internet and email made teletype obsolete. In fact, in web speak, use of capital letters became synonymous with angry shouting. However, it took the next 20 years or so for users of Weather Service products to phase out the last of the old equipment that would only recognize teletype.

Recent software upgrades to the computer system that forecasters use to produce weather predictions, called AWIPS 2 (The Advanced Weather Interactive Processing System), are allowing for the change to mixed-case letters. The switch will happen on May 11, after the required 30-day notification period to give customers adequate time to prepare for the change.

“People are accustomed to reading forecasts in upper case letters and seeing mixed-case use might seem strange at first,” said NWS meteorologist Art Thomas. “It seemed strange to me until I got used to it over the course of testing the new system, but now it seems so normal,” he said.

Three forecast products will transition to mixed-case use on May 11, including area forecast discussions, public information statements and regional weather summaries. Severe weather warnings will transition this summer, with other forecasts and warnings transitioning to the new system through early next year.

Upper case letters in forecasts will not become obsolete – forecasters will have the option to use all capital letters in weather warnings to emphasize threats during extremely dangerous situations. Certain forecast products with international implications, such as aviation and shipping, will continue to use upper case letters, per international agreements that standardize weather product formats across national borders.

NOAA's mission is to understand and predict changes in the Earth's environment, from the depths of the ocean to the surface of the sun, and to conserve and manage our coastal and marine resources. Join us on Twitter, Facebook, Instagram and our other social media channels.


Weather Briefings

The Aeronautical Information Manual (AIM) gives us some great guidance in Chapter 7. You should request a Standard Briefing any time you are planning a flight and you have not received a previous briefing or have not received preliminary information through mass dissemination media. The briefer will automatically provide the following information (below) in the sequence listed, except as noted, when it is applicable to your proposed flight.

Standard Briefing

Once you tell the briefer your specific information (type of flight - VFR or IFR, aircraft number or pilot's name, aircraft type, estimated time of departure), where you are departing from, your intended destination, and altitude - he/she will provide you the following information:

1. Adverse Conditions
2. VFR Flight Not Recommended
3. Weather Synopsis
4. Current Conditions
5. Enroute Forecast
6. Destination Forecast
7. Winds Aloft
8. Notices to Airmen (NOTAMs)
9. ATC Delays

Explanations for all these items are available in the AIM and should be consulted for specific guidance."

From the Aeronautical Information Manual, Chapter 7:

1. Adverse Conditions. Significant meteorological and/or aeronautical information that might influence the pilot to alter or cancel the proposed flight; for example, hazardous weather conditions,airport closures, air traffic delays, etc. Pilots should be especially alert for current or forecast weather that could reduce flight minimums below VFR or IFR conditions. Pilots should also be alert for any reported or forecast icing if the aircraft is not certified for operating in icing conditions. Flying into areas of icing or weather below minimums could have disastus results.

2. VFR Flight Not Recommended. When VFR flight is proposed and sky conditions or visibilities are present or forecast, surface or aloft, that, in the briefer's judgment, would make flight under VFR doubtful, the briefer will describe the conditions, describe the affected locations, and use the phrase "VFR flight not recommended." This recommendation is advisory in nature. The final decision as to whether the flight can be conducted safely rests solely with the pilot. Upon receiving a "VFR flight not recommended" statement, the non−IFR rated pilot will need to make a "go or no-go" decision. This decision should be based on weighing the current and forecast weather conditions against the pilot's experience and ratings. The aircraft's equipment, capabilities and limitations should also be considered.

NOTE − Pilots flying into areas of minimal VFR weather could encounter unforecasted lowering conditions that place the aircraft outside the pilot's ratings and experience level. This could result in spatial disorientation and/or loss of control of the aircraft.

3. Synopsis. A brief statement describing the type, location and movement of weather systems and/or air masses which might affect the proposed flight. NOTE − These first 3 elements of a briefing may be combined in any order when the briefer believes it will help to more clearly describe conditions.

4. Current Conditions. Reported weather conditions applicable to the flight will be summarized from all available sources; e.g., METARs/SPECIs, PIREPs, RAREPs. This element will be omitted if the proposed time of departure is beyond 2 hours, unless the information is specifically requested by the pilot.

5. Enroute Forecast. Forecast en route conditions for the proposed route are summarized in logical order; i.e., departure/climbout, en route, and descent. (Heights are MSL, unless the contractions "AGL" or "CIG" are denoted indicating that heights are above ground.)

6. Destination Forecast. The destination forecast for the planned ETA. Any significant changes within 1 hour before and after the planned arrival are included.

7. Winds Aloft. Forecast winds aloft will be provided using degrees of the compass. The briefer will interpolate wind directions and speeds between levels and stations as necessary to provide expected conditions at planned altitudes. (Heights are MSL.) Temperature information will be provided on request.

8. Notices to Airmen (NOTAMs).

(a) Available NOTAM (D) information pertinent to the proposed flight, including special use airspace (SUA) NOTAMs for restricted areas, aerial refueling, and night vision goggles (NVG). NOTE − Other SUA NOTAMs (D), such as military operations area (MOA), military training route (MTR), and warning area NOTAMs, are considered "upon request" briefing items as indicated in paragraph 7 −1−4b10(a).

(b) Prohibited Areas P−40, P−49, P−56, and the special flight rules area (SFRA) for Washington, DC.

(c) FSS briefers do not provide FDC NOTAM information for special instrument approach procedures unless specifically asked. Pilots authorized by the FAA to use special instrument approach procedures must specifically request FDC NOTAM information for these procedures. NOTE − NOTAM information may be combined with current conditions when the briefer believes it is logical to do so. NOTE − NOTAM (D) information and FDC NOTAMs which have been published in the Notices to Airmen Publication are not included in pilot briefings unless a review of this publication is specifically requested by the pilot. For complete flight information, you are urged to review the printed NOTAMs in the Notices to Airmen Publication and the A/FD in addition to obtaining a briefing.

9. ATC Delays. Any known ATC delays and flow control advisories which might affect the proposed flight.