McIDAS Learning Guide
Version 2015

## MD Files - Searching MD Files

The SFCLIST and UALIST commands list out weather observations in an easy to read tabular format. The default for these commands is to list the observations from the current day and time from the real-time datasets. By specifying the TIME, DAY, and DATASET keywords, you will be able to access the Storm of the Century data in the BLIZZARD dataset. If you need to specify which parameters to list, or want to change the format of the output extensively, you will have to use the PTLIST command.

In this exercise, you will use the SFCLIST and UALIST commands to list out weather data for Cape Hatteras, North Carolina, as well as for the entire state of North Carolina. You will then use the PTLIST command to format the data more specifically.

1. List 12 hours of surface hourly data for Cape Hatteras, North Carolina.
Type:  SFCLIST HAT DATASET=BLIZZARD/SFCHOURLY TIME=0 12 DAY=93072
2. List the surface hourly data for North Carolina at 18 UTC, including the windchill and precipitation information.
Type:  SFCLIST NC DATASET=BLIZZARD/SFCHOURLY TIME=18 DAY=93072 OPT=CHILL PRECIP
3. List the surface hourly data for North Carolina at 18 UTC, using the wind chill formula used by the NWS before November 2001. Note the differences in wind chill!
Type:  SFCLIST NC DATASET=BLIZZARD/SFCHOURLY TIME=18 DAY=93072 OPT=CHILL PRECIP CHILLTYPE=OLD
4. List the upper-air data from 00 UTC at Cape Hatteras, North Carolina.
Type:  UALIST KHAT 00 93072 DATASET=BLIZZARD/UPPERMAND

This command takes a bit longer than the SFCLIST command, because it is interpolating the values at all levels and also calculating all of the stability parameters for the sounding.
5. List the temperature (T) and dew point (TD), in degrees Fahrenheit, for Cape Hatteras, North Carolina, at 0 UTC. The PARAM keyword defines what data types in the matching records to list and the SELECT keyword defines which records to match. You must surround the SELECT variable with single quotes and separate individual select clauses with semicolons.
Type:  PTLIST BLIZZARD/SFCHOURLY.1 PARAM=T[F] TD[F] SELECT='ID HAT;TIME 0'
The temperature in Cape Hatteras at 00 UTC was 46.00° and the dew point was 41.99°

6. List the station identifier (ID), temperature (T), and dew point (TD) of the first reported observation for North Carolina at 15 UTC. Display the temperature and dew point in Fahrenheit.
Type:  PTLIST BLIZZARD/SFCHOURLY.1 PARAM=ID T[F] TD[F] SELECT='ST NC;TIME 15' FORMAT=X I6 I6
The station in Wilmington, North Carolina, reporting a temperature of 60° and a dew point temperature of 58° at 15 UTC is listed.

7. List all occurences of station ID, temperature, and dew point in North Carolina at 15 UTC.
Type:  PTLIST BLIZZARD/SFCHOURLY.1 PARAM=ID T[F] TD[F] SELECT='ST NC;TIME 15' FORMAT=X I6 I6 NUM=ALL
The ALL parameter lists all reporting stations in the MD file that match the criteria. Without the ALL parameter only the first match is listed (as in exercise 5).

8. List all occurences of station ID, time (TIME), precipitation (PCP), and wind gusts (GUS) in North Carolina from 18 to 20 UTC. List the data in units of inches and miles per hour.
Type:  PTLIST BLIZZARD/SFCHOURLY.1 PARAM=ID TIME PCP[IN] GUS[MPH] SELECT='ST NC;TIME 18 20' NUM=ALL