RE: watch/warning updates


Robert,

   Is GEMPAK and/or McIDAS capable of drawing the NWS polygons of
updates watch/warning areas?  I know GEMPAK has a decoder, but I never
could get it to draw the polygon defined by that lat/lon points in the
update using the standard GEMPAK tools.


If you have a specific question regarding pqact entries for dcwcn, dcwou, or 
dcwcp and or displaying the results in gpmap or nmap2, I can help you with 
those as well as if you can provide specific instances of what you are 
missing/expecting to display.

Regarding the status lines for the initial watch boxes which GEMPAK can draw in 
GPMAP/NMAP2 using the WATCH parameter, such as: 
http://www.unidata.ucar.edu/staff/chiz/gifs/statuslines.gif the dcwtch decoder 
is handling the update based on the WOUS20 KWNS bulletin lines such as:
WOUS20 KWNS 101851
WWASPC
SPC WW-A 101855
TXZ000-CWZ000-101940-

STATUS REPORT ON WW 822

SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 20 ENE VCT
TO 20 NW PSX TO 30 W LBX TO 15 SW HOU TO 30 NNE HOU.

That is different than the polygon points such as Russ mentioned in the
tornado warning bulletin.

The WOU and WCN bulletins that you mentioned do not have the lat/lon
pairs at the end, but rather use the VTEC /UGC lines eg WOUS6x KWNS:

TORNADO WATCH 822 REMAINS IN EFFECT UNTIL 700 PM CDT FOR THE
FOLLOWING LOCATIONS
TXC039-057-071-157-167-199-201-239-245-291-321-361-469-481-
110000-
/O.CON.KWNS.TO.A.0822.000000T0000Z-061011T0000Z/

GEMPAK uses the bounds tables for the counties to draw these regions in the WOU 
parameter.  You can draw the counties separately, or the UNION of the counties, 
such as is shown in the composite of WATCH & WOU here:
http://www.unidata.ucar.edu/staff/chiz/gifs/watch_wou.gif

The dcwcp watch corner point decoder is capable of handling complex polygons for the corner points, but at the moment, these bulletins are only using 4 points (unlike the tornado warning that Russ showed which contains greater than 4 points). There is some overlap currently in the watch outline and update bulletins which might be somewhat confusing as well since you can gather some information from more than one bulletin ID.

Steve Chiswell
Unidata User Support



On Mon, 2006-10-16 at 15:38 -0500, Robert Mullenax wrote:
Just to clarify, I was talking about the updates to the initial
watches...the WOU/WCN bulletins...etc.