MesoWest has been designed for use by National Weather Service meteorologists and other professionals for protection of life and property. Comments/suggestions for improvement may be sent to firstname.lastname@example.org.
Some recent additions have been added to the MesoWest Station Interface Display for stations that are a part of the NWS/FAA Automated Surface/Weather Observing System (ASOS/AWOS) network.
NWS/FAA Stations with Observations every 5 Minutes
MesoWest recently gained access to a new data feed of high frequency (5 minute) observations for many of the stations available in the NWS/FAA network. This data feed has been combined with the original hourly data feed to provide as many real-time observations for these stations as possible through the MesoWest products.
However, the new 5-minute data feed does have a few caveats. The temperature observations for the 5-minute data are only available in whole degrees Celsius (e.g., 29 degrees C), compared to the hourly observations which are usually available in tenths (e.g., 28.7 degrees C). This can cause some discrepancies in calculated high and low temperatures in MesoWest, primarily due to the rounding of temperatures to whole degrees Celsius in the 5-minute observations (e.g., 28.7 is reported as 29 degrees C). These discrepancies get propagated along in MesoWest when converting temperatures from Celsius to Fahrenheit as well. The issue is known within the NWS and FAA communities, and options are being considered to address this and other concerns.
How to Estimate Maximum/Minimum Temperatures in MesoWest for NWS/FAA Stations
Within the MesoWest web and API systems, efforts are underway to address these concerns as it relates to reported maximum and minimum temperatures.
Many stations in the NWS/FAA network report maximum and minimum temperatures a bit differently compared to most other networks in MesoWest. Every 6 hours near 00:00, 06:00, 12:00, and 18:00 Greenwich Mean Time (GMT), many NWS/FAA stations report a 6 hour maximum and minimum temperature. Once a day, around midnight local standard time, 24 hour maximum and minimum temperatures for the previous day can also be reported.
On the MesoWest Station Interface Display, the reported 6 and 24 hour maximum and minimum temperatures, along with reported peak wind speeds, are available for NWS/FAA stations as additional columns in the Tabular Observation Listing. Calculated maximum and minimum values for all observations are still shown in the first table, just like all other MesoWest stations, but are considered as "unofficial" as they are only calculated from the observed values given in the Tabular Observation Listing.
To improve exposure of the reported maximum and minimum values by NWS/FAA stations, a new summary table called ASOS/AWOS Station Summary was added for NWS/FAA sites to display the values in a more concise manner. The ASOS/AWOS Station Summary table contains the following if reported by the station:
The most recent and highest 6 hr high temperatures reported by the station
The most recent and lowest 6 hr low temperatures reported by the station
The most recent 24 hr high and low temperatures reported
The most recent and highest peak wind speeds or gusts reported (if available)
For each listing in the table, the timestamp of the observation the value was included with is provided, which can be verified by viewing the observation table available below. Note that this is not the time the actual value took place, but rather just when it was transmitted by the station. The "Max/Min Values Last 24 Hours" column can provide an estimate on recorded highs and lows by the station, but it is important to keep in mind that these values represent maxima/minima from long time periods (either 6 or 24 hours).
For any questions on these updates, feel free to contact the MesoWest group at any time via the email address below.