The 00z maps are produced at 01z using the available upper air data with a first guess from the 18z NAM 6-hour forecast for the objective analysis. The 12z maps are produced at 13z using the 06z NAM 6-hour forecast as a first guess for the objective analysis. If the 18z or 06z NAM runs are unavailable, a first guess from the 12-hour foreacst of the 00z or 12z NAM is used. Errors may result if NAM model data is not available, or if sounding data is late or erroneous.

Updated: (1 September 2023) SPC is now recreating the UA maps one hour later since Mexican UA data sometimes arrives late. The UA maps are generated at 0101, 0201, 1301, and 1401 UTC (i.e. during Central Daylight Time this is 8:01 pm, 9:01 pm, 8:01 am, and 9:01 am).

00Z 12/22/24 maps available.

Data should exist back to around 11/30/98.
Note: You can also view the current day's images through this interface as well.

Retrieve Printable Unanalyzed Maps (maps available after 20110108)
Note:To access archived unanalyzed printable maps, the URL is https://www.spc.noaa.gov/obswx/maps/XXX_YYMMDD_HH.pdf, where XXX = {sfc, 925, 850, 700, 500, 300, 250}, HH = {00, 12}