Maps are archived for use as a research or learning tool.
Hourly surface maps are available for the past 24-hours.
Three-hourly data has been archived since Feb 1st, 2016.
Use the interface below to select a different date/time than the most recent, then use the map/links above to display the map for the selected time.
Choose a date:
Select Date/Time for archived maps
>> Plotting Method
The charts provided on this webpage include surface observations from numerous sources, and with varied accuracy requirements.
For this reason, they should be used for subjective analysis only.
The plotting process for these charts is considerably different than most other surface data plots, making them much more useful for hand analysis.
Radar base-reflectivity is underlaid on the charts to help identify areas of precipitation.
Standard NWS/FAA observations at airports across the county are plotted first, in two passes. First,
only those sites that report mean sea-level (MSL) pressure are plotted to provide maximum coverage of these stations.
Next, a second pass plots the remainder of these standard observations that do not report MSL pressure.
Ship and buoy observations are plotted next for offshore and lake data.
Various established mesonet observations from federal, state, and local governmental and research organizations are plotted. (MADIS)
Ameteur and home-weather stations from around the nation are used as gap-filling observations where other data is not available. (MADIS)
Two-hour pressure changes are plotted in the lower-right (when available). This parameter has been effectively used for decades as a severe-weather
All plotted data uses a tuned filter to provide maximum readability, while also providing the most dense data-plot available.
>> What is plotted?
>> The Role of Manual Surface Analysis at SPC
The detailed manual analysis of surface data has been a major component of severe storm forecasting for more than 60 years. Early pioneers in tornado forecasting recognized this in their research.
"The surface map is generally given first consideration in evaluating the tornado threat of a particular situation.(US Weather Bureau Forecasting Guide No. 1: Forecasting Severe Thunderstorms and Tornadoes, 1956)
"The surface chart with its relatively dense network of stations and more frequent reporting times is probably the most valuable chart available to the severe weather forecaster". (Notes on Analysis and Severe-Storm Forecasting Procedures of the Air Force Global Weather Central, 1972)
Although remarkable advances in observational data from Doppler radar and geostationary satellite systems provide near real-time views of weather systems and storms, and high-resolution numerical models provide guidance on future storm development, SPC forecasters continue to manually analyze surface charts as part of their routine severe weather forecasting process. In particular, surface analysis provides a foundational basis for the identification of air mass characteristics and boundaries such as fronts, dry lines, convective outflow/gust fronts, etc., that provide important insights into more likely locations of thunderstorm development and the evolution of ongoing storms.
The charts available on this page are almost identical to the ones used by SPC forecasters on a day-to-day basis to perform mesoscale surface analysis.
>> Other Information
* These charts are updated between 5 and 10 minutes after the top of every hour.
Notice: NOAA and its data providers disclaim liability of any kind whatsoever, including, without limitation, liability for quality, performance, merchantability and fitness for a particular purpose arising out of the use or inability to use the data.
Please contact John Hart if you have questions or comments regarding this resource.