McIDAS Learning Guide
Version 2015

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Real-time Data Access - NWS Radar Imagery

Many of the same commands used to display satellite images can be used with National Weather Service (NWS) Radar data as well. In this excercise, you will access real-time NWS Radar imagery, find a NWS Radar station where precipitation exists (if any) and list and display that station's radar image.

The DSINFO and IMGLIST commands list information about the available images. Once located, you can display the images using the IMGDISP command. You can display images one at a time or in a sequence. An entire set of images can be loaded chronologically using one IMGDISP command.

  1. List all radar datasets from group WSR (Weather Service Radar) of type IMAGE in your routing table.
             Dataset Names of Type: IMAGE in Group: WSR
     Name         NumPos   Content
     ------------ ------   --------------------------------------
     BREF1        99999    Base Reflec - tilt 1 (0.5deg)          248nmi 8bit (N0Q)
     BREF2        99999    Base Reflec - tilt 2 (0.9deg)          248nmi 8bit (NAQ)
     BREF3        99999    Base Reflec - tilt 3 (1.3|1.5deg)      248nmi 8bit (N1Q)
     BREF4        99999    Base Reflec - tilt 4 (1.8deg)         248nmi 8bit (NBQ)
     BREF5        99999    Base Reflec - tilt 5 (2.4|2.5deg)      248nmi 8bit (N2Q)
     BREF6        99999    Base Reflec - tilt 6 (3.1|3.4|3.5deg)  248nmi 8bit (N3Q)
     BVEL1        99999    Base Rad Vel - tilt 1 (0.5deg)         162nmi 8bit (N0U)
     BVEL2        99999    Base Rad Vel - tilt 2 (0.9deg)         162nmi 8bit (NAU)
     BVEL3        99999    Base Rad Vel - tilt 3 (1.3|1.5deg)     162nmi 8bit (N1U)
     BVEL4        99999    Base Rad Vel - tilt 4 (1.8deg)         162nmi 8bit (NBU)
     BVEL5        99999    Base Rad Vel - tilt 5 (2.4|2.5deg)     162nmi 8bit (N2U)
     BVEL6        99999    Base Rad Vel - tilt 6 (3.1|3.4|3.5deg) 162nmi 8bit (N3U)
     COR1         99999    Correlation Coef - tilt 1 (0.5deg)                 (N0C)
     COR2         99999    Correlation Coef - tilt 2 (0.9deg)                 (NAC)
     COR3         99999    Correlation Coef - tilt 3 (1.3|1.5deg)             (N1C)
     COR4         99999    Correlation Coef - tilt 4 (1.8 deg)                (NBC)
     COR5         99999    Correlation Coef - tilt 5 (2.4|2.5deg)             (N2C)
     COR6         99999    Correlation Coef - tilt 6 (3.1|3.4|3.5deg)         (N3C)
     CREF         99999    Composite Reflectivity - 124nmi - 4bit             (NCR)
     DAA          99999    Digital Accumulation Array                         (DAA)
     DHR          99999    Digital Hybrid Scan Reflectivity                   (DHR)
     DOD          99999    Digital One Hour Difference                        (DOD)
     DPA          99999    Digital Precipitation Array                        (DPA)
     DREF1        99999    Diff Reflec - tilt 1 (0.5deg)               248nmi (N0X)
     DREF2        99999    Diff Reflec - tilt 2 (0.9deg)               248nmi (NAX)
     DREF3        99999    Diff Reflec - tilt 3 (1.3|1.5deg)           248nmi (N1X)
     DREF4        99999    Diff Reflec - tilt 4 (1.8deg)               248nmi (NBX)
     DREF5        99999    Diff Reflec - tilt 5 (2.4|2.5deg)           248nmi (N2X)
     DREF6        99999    Diff Reflec - tilt 6 (3.1|3.4|3.5deg)       248nmi (N3X)
     DSD          99999    Digital Storm Total Difference                     (DSD)
     DSP          99999    Digital Storm Total Precipitation                  (DSP)
     DTA          99999    Digital Storm Total Accumulation                   (DTA)
     DVIL         99999    Digital Vertical Integrated Liquid - 8bit          (DVL)
     ENHTOPS      99999    Enhanced Echo Tops - 8bit                          (EET)
     HHC          99999    Hybrid Scan Hydrometeor Classification             (HHC)
     HMC1         99999    Hydrometeor Class - tilt 1 (0.5deg)                (N0H)
     HMC2         99999    Hydrometeor Class - tilt 2 (0.9deg)                (NAH)
     HMC3         99999    Hydrometeor Class - tilt 3 (1.3|1.5deg)            (N1H)
     HMC4         99999    Hydrometeor Class - tilt 4 (1.8 deg)               (NBH)
     HMC5         99999    Hydrometeor Class - tilt 5 (2.4|2.5deg)            (N2H)
     HMC6         99999    Hydrometeor Class - tilt 6 (3.1|3.4|3.5deg)        (N3H)
     OHA          99999    One Hour Accumulation                              (OHA)
     PCP1         99999    Surface Rainfall - 1 hour running total            (N1P)
     PCPT         99999    Surface Rainfall - storm total                     (NTP)
     PTA          99999    Storm Total Accumulation                           (PTA)
     SDP1         99999    Spec Diff Phase  - tilt 1 (0.5deg)                 (N0K)
     SDP2         99999    Spec Diff Phase  - tilt 2 (0.9deg)                 (NAK)
     SDP3         99999    Spec Diff Phase  - tilt 3 (1.3|1.5deg)             (N1K)
     SDP4         99999    Spec Diff Phase  - tilt 4 (1.8 deg)                (NBK)
     SDP5         99999    Spec Diff Phase  - tilt 5 (2.4|2.5deg)             (N2K)
     SDP6         99999    Spec Diff Phase  - tilt 6 (3.1|3.4|3.5deg)         (N3K)
     SRVEL1       99999    Storm-Rel Mean Rad Veloc - tilt 1 (0.5deg)         (N0S)
     SRVEL2       99999    Storm-Rel Mean Rad Veloc - tilt 2 (1.3|5deg)       (N1S)
     SRVEL3       99999    Storm-Rel Mean Rad Veloc - tilt 3 (2.4|5deg        (N2S)
     SRVEL4       99999    Storm-Rel Mean Rad Veloc - tilt 4 (3.1|3.4|3.5deg) (N3S)
     TOPS         99999    Echo Tops                                          (NET)
     VIL          99999    Vertical Integrated Liquid                         (NVL)   
  2. Erase frames 1 through 6.
    Type:  ERASE F 1 6
  3. Display a map of the United States on frame 1 and show the current weather conditions by displaying weather symbols.
    The parameter WXS displays weather symbols of the current weather conditions.

  4. Choose a station in which rain, snow, or some other type of precipitation is occuring and place the cursor over the symbol.

  5. Find any nearby NWS Radar stations using the STNLIST command.
    The TYPE keyword allows you to search for specific types of stations. In this example, you are only searching for NWS Radar stations (N) in the surrounding area.

    You should see an output similar to this:

     Center Lat/Lon: 43:08:38 84:36:00                                                      
     IDN   ID     Station Name         Data Types        ST CO DIST[KM]   LAT         LON       ELE
     ----- -----  -------------------- ----------------- -- -- ---------- ----------  --------- ---- 
      ---  GRR    GRAND RAPIDS                 NW        MI US    81.7     42:53:38   85:32:41   299
      ---  DTX    DETROIT                      N         MI US   104.3     42:41:59   83:28:18   412
     Number of stations listed: 2                                                           
  6. Choose a station ID and display the base reflectivity (tilt 1, 248 nmi range) image from that station (in this case, DTX, Detroit, Michigan) with a red map on frame 2.
  7. Another way to display the same station is to use the predefined NWS Radar product aliases found in IMGDISP.CORE. Display the IMGDISP.CORE context file.
    After the comments section of the IMGDISP.CORE file, you will see predefined products in sections like this:
       # Products for WSR Base Reflectivity, tilt 1 (0.5deg)
              REFRESH='BAR (IMA) GRA=(GRA); \
              EU MAKE 1 1 50 50 50 50 50 50 (IMA) (IMA); \
              EU MAKE 2 2 WHITE WHITE (IMA) (IMA); \
              EU MAKE 3 3 BLACK BLACK (IMA) (IMA); \
              MAP X -8 DASH=1 X 4 COUNTY=ALL GRA=(GRA) IMA=(IMA); \
              MAP X  7 GRA=(GRA) IMA=(IMA); \
              FRMLABEL LEV=2 3 IMA=(IMA) \
              "(ID) WSR - BASE REFLECTIVITY - TILT 1 AT (HHMM) ON (DAY)'     
  8. Take a closer look at each individual line of the MKX_BREF1 predefined product, to see exactly what it does.
  9. Display the same station's three most recent NWS Radar images on frame 3-5, using the predefined product, MKX_BREF1, and the station you chose in step 6 (in this case, DTX). If MKX is the station you chose, you do not need to specify ID=, since ID=MKX is the default.
  10. Loop the images to see the movement of the storm.
    Type:  LB 3 5
    Press:  Alt L
    Press:  Alt L
  11. Display the total surface rainfall accumulation using the predefined PCPT (storm total precipitation) product on frame 6.
  12. Place the cursor over different areas of precipitation and use IMGPROBE to determine the total amount of precipitation over those selected ares.
    Type:  IMGPROBE
    Press:  Alt G
    Repeat this as many times as you like.

  13. Exit IMGPROBE using Alt Q.
    Press:  Alt Q

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