Welcome Guest. Sign in or Signup

4 Answers

Weather Forecast Time Periods

Asked by: 6545 views ,
General Aviation

I'm confused about how to interpret time periods for weather forecasts. For example, when a forecast says it's a 12 hour forecast does that mean the forecast was made 12 hours prior to the valid time or that the forecast is for a period of time for 12 hours following the valid time? 

In the explanation below, what is meant by the "forecast interval"?

Low altitude Significant Weather charts are issued four times daily and are valid at fixed times: 0000, 0600, 1200, and 1800 UTC. Each 4 panel chart is divided on the left and right into 12 and 24 hour forecast intervals (based on the current ETA model available).

Thanks

mm

Ace Any FAA Written Test!
Actual FAA Questions / Free Lifetime Updates
The best explanations in the business
Fast, efficient study.
Pass Your Checkride With Confidence!
FAA Practical Test prep that reflects actual checkrides.
Any checkride: Airplane, Helicopter, Glider, etc.
Written and maintained by actual pilot examiners and master CFIs.
The World's Most Trusted eLogbook
Be Organized, Current, Professional, and Safe.
Highly customizable - for student pilots through pros.
Free Transition Service for users of other eLogs.
Our sincere thanks to pilots such as yourself who support AskACFI while helping themselves by using the awesome PC, Mac, iPhone/iPad, and Android aviation apps of our sponsors.

4 Answers



  1. Brian on Oct 24, 2011

    ” For example, when a forecast says it’s a 12 hour forecast does that mean the forecast was made 12 hours prior to the valid time or that the forecast is for a period of time for 12 hours following the valid time? ”
     
    No. It is released at 0000, 0600, etc; as you’re quoted text indicates. Depending on when you view the chart, the most recent 6 hour interval (getting to this word momentarily) will be the time that forecast was made. 
     
    “what is meant by the “forecast interval”?”
     
    Interval just means a space/section of time. In this case a, 12 hour and 24 hour intervals. If it helps, you may ignore the that word in your quoted definition without losing the overall context. I.E. — “Each 4 panel chart is divided on the left and right into 12 and 24 hour forecasts.”

    +2 Votes Thumb up 2 Votes Thumb down 0 Votes



  2. james r pierrot on Aug 25, 2013

    Interpret this valid time 1200utc20120611

    0 Votes Thumb up 0 Votes Thumb down 0 Votes



  3. james r pierrot on Aug 25, 2013

    I have been given a question to interpret a valid time, I do not know this format.

    1200utc20120611?

    I get the 1200Zulu but not the rest

    0 Votes Thumb up 0 Votes Thumb down 0 Votes



  4. Mark Kolber on Aug 26, 2013

    1200utc20120611

    Does that help?

    BTW, what chart are they referring to? I’m not aware of any of the “official” charts that current use that format.

    0 Votes Thumb up 0 Votes Thumb down 0 Votes


The following terms have been auto-detected the question above and any answers or discussion provided. Click on a term to see its definition from the Dauntless Aviation JargonBuster Glossary.

Answer Question

Our sincere thanks to all who contribute constructively to this forum in answering flight training questions. If you are a flight instructor or represent a flight school / FBO offering flight instruction, you are welcome to include links to your site and related contact information as it pertains to offering local flight instruction in a specific geographic area. Additionally, direct links to FAA and related official government sources of information are welcome. However we thank you for your understanding that links to other sites or text that may be construed as explicit or implicit advertising of other business, sites, or goods/services are not permitted even if such links nominally are relevant to the question asked.