Chart Validity
Thread Starter
Join Date: Nov 2004
Location: Dublin, Ireland
Posts: 105
Likes: 0
Received 0 Likes
on
0 Posts
Chart Validity
Hi all,
Quick Question Regarding Time Validity of Significant Prognostic & Wind Charts,
When a Chart is Valid say 18:00 , does this mean up until 18:00, between 12:00 and 18:00
or
Valid AT 18:00 ?
for example a 1hr flight departing 14:00, should they have 12:00 , 18:00 or both?
thanks,
-Jd
Quick Question Regarding Time Validity of Significant Prognostic & Wind Charts,
When a Chart is Valid say 18:00 , does this mean up until 18:00, between 12:00 and 18:00
or
Valid AT 18:00 ?
for example a 1hr flight departing 14:00, should they have 12:00 , 18:00 or both?
thanks,
-Jd
Join Date: Apr 2007
Location: HKT
Age: 64
Posts: 225
Likes: 0
Received 0 Likes
on
0 Posts
Generally these charts show you the predicted wx at that time of validity, not for a range of time.
But as these charts are issued 6hrs apart we consider the "validity" +/-3hrs.
For your example the flight should carry 1200 and 1800.
But as these charts are issued 6hrs apart we consider the "validity" +/-3hrs.
For your example the flight should carry 1200 and 1800.
Join Date: Apr 2006
Location: USA
Posts: 242
Likes: 0
Received 0 Likes
on
0 Posts
So just building on the previous posters comments:
Progs potray forecasts of selected weather conditions at specified valid times. Each valid time is the time at which the forecast conditions are expected to occur. A 12 hour-hr prog is a forecast of conditions which has a valid time 12 hours after the obeserved data base time, thus a 12 hr forecast. For example, a 12 hour forecast based on 00z observations is valid at 12z.
I guess you are asking this question based on the fact so what do I look at at 1132z? or 1035z?
The correct way is to treat exactly like FD forecasts: yes, interperlate....if on a 00z sig wx front 'A' is at X and on the 06z prog at Y then work on the basis that at 03z it is.....answers on a post card!
Progs potray forecasts of selected weather conditions at specified valid times. Each valid time is the time at which the forecast conditions are expected to occur. A 12 hour-hr prog is a forecast of conditions which has a valid time 12 hours after the obeserved data base time, thus a 12 hr forecast. For example, a 12 hour forecast based on 00z observations is valid at 12z.
I guess you are asking this question based on the fact so what do I look at at 1132z? or 1035z?
The correct way is to treat exactly like FD forecasts: yes, interperlate....if on a 00z sig wx front 'A' is at X and on the 06z prog at Y then work on the basis that at 03z it is.....answers on a post card!
