First Available BLIPMAP Times

CACHE WARNING

Users trying to obtain the very latest on-line BLIPMAP prediction should be aware of possible "caching" issues (storing of a webpage), either by their browser or by their internet provider (AOL is infamous for this), since it is then possible to be shown an out-of-date cached page instead of the latest on-line page. On my Mozilla browser under "Cache" settings I have told it to compare the on-line page to the cached page every time I view a page, so it will then get the on-line page if it is newer than the cached page (not "once per session" or "when the page is out of date" or "never", the other possible choices). I understand there are similar ways to control caching on other browers and on AOL, but I do not know the details (try a Google search!).

If caching is a problem the following scenario might occcur: you first ask for a BLIPMAP webpage before a plot is actually available for that day and get a "Not Available" message - then the next time you ask for the page, at a later time when a new BLIPMAP is now actually available on-line, the caching gives you the (old) cached page instead of the latest on-line page and you will continue to think that a BLIPMAP is still not available.

Also, sometimes the cache problem occurs because one clicks on the "reload" button and the browser simply reloads the page from cache. With some browsers there is a way of forcing the browser to get the webpage off the internet, no matter what the cache settings - in Mozilla and Netscape browsers this is done by holding down the "Shift" key when clicking on the "reload" button. I have no idea whether IE has a similar feature.

Time of First Available BLIPMAP

As of September, with the introduction of processing at all times for all regions, the first 18Z regional BLIPMAPs can appear as early as 0200Z and the first 21Z regional BLIPMAPs as early as 0230Z, depending as always on file availability at GSD. The variability of the first available time can be determined from the "Log of First Available 18Z and 21Z BLIPMAP Times" below.
BLIPMAP availability ultimately depends upon GSD file availability. The FLS RAP is a research model and only semi-operational, so missing forecasts are much more likely than for NWS operational models. It is my impression that data access problems and missing files are more likely on the weekends than during the week (perhaps there is no one around then to notice or correct when things go wrong), which is unfortunate for weekend glider pilots.

"Near Ideal" BLIPMAP Availability Times

The following gives the BLIPMAP availability times (in Z) for a run with the BLIPMAP program begun at 00:30Z and "near-perfect" file availability at GSD. ("old" indicates that the file was not processed due to previous processing of a file for the same validation time but a shorter forecast period.)

Fcst "NEAR-IDEAL" SUCCESS SUMMARY: (March 21, 2003) Processed= 52/56 Successful= 42 Skipped= 0 Pd -- ----------------------------------Validation-Time---------------------------------------------- (hr) 12Z 13Z 14Z 15Z 16Z 17Z 18Z 19Z 20Z 21Z 22Z 23Z 0Z 1Z 2Z 3Z -- ----------------------------------------------------------------------------------------------- 24 old old old old 05:15 06:18 21 old old old 02:31 06:05 09:56 18 old old 02:12 05:31 09:03 11:53 15 old 02:58 05:13 08:18 11:24 14:54 12 02:43 05:48 08:01 11:08 14:22 17:18 9 04:56 08:46 10:51 14:06 17:01 19:54 6 07:38 08:30 10:07 10:34 11:40 12:30 13:50 14:39 15:39 16:40 17:38 18:42 19:39 20:33 21:33 22:33

Log of First Available 18Z and 21Z BLIPMAP Times

The log below indicates the time of the first available 18Z and 21Z BLIPMAPs from March 27,2002 to July 2, 2002. However, with the introduction of processing at all times for all regions in Sept 2002, the start-up now takes roughly one hour longer than previously so the initial times below should be increased by about an hour.

	28Mar-2Jul(2002) = 97 Days

Time GMT	18Z	21Z
Never: my site problem	0	0
Never: GSD site problem	1	4
Never: web site problem	0	0
Never: unknown problem	0	0
00:30-00:44
00:40-00:49	8
00:50-00:59	52
01:00-01:09	9
01:10-01:19	4	9
01:20-01:29	4	25
01:30-01:39	7	11
01:40-01:49	2	6
01:50-01:59		3
02:00-02:09	1	4
02:10-02:19	1
02:20-02:29	1	3
02:30-02:39	1	1
02:40-02:49	1
02:50-02:59	1	4
03:00-03:09		5
03:10-03:19	1	2
03:20-03:29
03:30-03:39		2
03:40-03:49
03:50-03:59
04:00-04:09
04:10-04:19
04:20-04:29		1
04:30-04:39		1
04:40-04:49		1
04:50-04:59
05:00-05:09
05:10-05:19
05:20-05:29
05:30-05:39
05:40-05:49		1
05:50-05:59		3
06:00-06:09
06:10-06:19
06:20-06:29
06:30-06:39
06:40-06:49
06:50-06:59
07:00-07:09
07:10-07:19
07:20-07:29		1
07:30-07:39
07:40-07:49
07:50-07:59		1
08:00-08:09
08:10-08:19
08:20-08:29	2
08:30-08:39
08:40-08:49		1
08:50-08:59		1
09:00-09:09
09:10-09:19		1
09:20-09:29
09:30-09:39
09:40-09:49	1
09:50-09:59
10:00-10:09
10:10-10:19
10:20-10:29
10:30-10:39
10:40-10:49
10:50-10:59
11:00-11:09
11:10-11:19
11:20-11:29
11:30-11:39		1
11:40-11:49
11:50-11:59
12:00-12:09
12:10-12:19
12:20-12:29
12:30-12:39
12:40-12:49
12:50-12:59
13:00-13:09
13:10-13:19
13:20-13:29
13:30-13:39
13:40-13:49
13:50-13:59
14:00-14:09	1
14:10-14:19		1
14:20-14:29
14:30-14:39		1
14:40-14:49
14:50-14:59	1
15:00-15:09
15:10-15:19
15:20-15:29
15:30-15:39
15:40-15:49
15:50-15:59
16:00-16:09
16:10-16:19
16:20-16:29
16:30-16:39
16:40-16:49
16:50-16:59
17:00-17:09
17:10-17:19
17:20-17:29
17:30-17:39
17:40-17:49
17:50-17:59
18:00-18:09
18:10-18:19
18:20-18:29
18:30-18:39
18:40-18:49
18:50-18:59
19:00-19:09
19:10-19:19
19:20-19:29
19:30-19:39		1
19:40-19:49
19:50-19:59
20:00-20:09
20:10-20:19
20:20-20:29
20:30-20:39
20:40-20:49
20:50-20:59
21:00-21:09
21:10-21:19
21:20-21:29
21:30-21:39
21:40-21:49
21:50-21:59
22:00-22:09
22:10-22:19
22:20-22:29
22:30-22:39
22:40-22:49
22:50-22:59