NEXRAD Inventory
Frequently Asked Questions
What are the differences between
Precipitation Mode and
Clear-Air Mode ?
The WSR-88D Radar System operates in several VCP (Volume Coverage Pattern) modes.
Some modes (VCP 11, 12, 121, 21) are designed for precipitation events while other modes
(VCP 31, 32) are designed for clear air.
(More VCP Information)
The VCP mode is estimated in NEXRAD Inventory Search by comparing the time differences between files.
If the files are less than 8 minutes apart, then Precipitation Mode is assumed. Inaccuracies
may occur when small numbers of files are missing.
Why do I need to enter my Email Address?
The user email address is needed when ordering data from NCDC. Due to the size of the Archive,
instantaneous access is not possible. The user is emailed when the ordered data has posted
to the NCDC FTP site.
How long will my order take?
The amount of time for each order is varies based on the size of the order.
An average order of 24 hours of data may take between 10 and 20 minutes.
What does the filename mean?
YYYY = year, MM = month, DD = day, HH = hour, MM = minute, SS = second
Level-II: AAAAYYYYMMDD_HHMMSS.Z or 6500AAAAYYYYMMDD_HHMMSS.Z
Where AAAA = 4-letter Radar ID, .Z = File Compression Type
Example: KHTX20020424_164107.Z or 6500KHTX20020424_164107.Z
Level-III: ABBB_CCCCCC_DDDAAA_YYYYMMDDHHMM
Where: AAAA = 4-letter ID of source Radar, BBB = 3-letter ID of transmitting Radar,
CCCCCC = WMO Abbreviated Heading, DDD = Level-III Product Code.
Example: KMHX_SDUS52_N0RMHX_200309182020 or 7000KMHX_SDUS52_N0RMHX_200309182020
Product Code Definitions
Decode WMO Heading
