Category : Science and Education
Archive   : WXVIEW.ZIP
Filename : WXVIEW.DOC

WXVIEW (demo version)
Version 2.4
(c) 1993 Jim Haywood
April 1993

1.0 WHAT IS WXVIEW?

WXVIEW was written to provide anyone with a MS-DOS based personal
computer and a modem the ability to view and analyze real-time National
Weather Service (NWS) hourly data. WXVIEW is offered as a shareware
program therefore registration cost is held to a minimum. This program
rivals or beats expensive commercial programs or other shareware
programs with the same goal. This is a DEMONSTRATION version designed
to allow the user to 'kick the tires' before expending any hard earned
cash. The demo version will work 100% with the supplied demo data set
but will be limited with user supplied NWS data.

Minimum computer hardware required to operate WXVIEW:

MS-DOS Environment
512K or more available memory
EGA video minimum
80286 Processor Minimum (80386 or better recommended)
Math Coprocessor not necessary but highly recommended

Running WXVIEW is as easy as 1,2,3:

1) Download NWS data
2) Reformat NWS data to column oriented format
3) Graphically display weather or search station data by event

Specific capabilities of the WXVIEW program include:

o Format raw NWS surface airways (SA) data and digital radar
(SD) data to a column oriented format;

o Graphically display the following data in national or zoom
mode:

- Current observations
- Cloud cover and base height
- Visibility in statute miles
- Pressure (with optional isobar plot)
- Temperature
- Dew point
- Wind direction and speed flags
- Digital radar map
- Available NWS cities
- Relative humidity
- Wind chill
- Apparent temperature (heat index)

o NWS data can be searched and displayed in common,
understandable text by the following criteria:
- Search by city name or NWS code
- Search by state
- Search for extremes in data set
- Search by following precipitation types:

Rain
Drizzle
Snow
Thunderstorm
Ice
Freezing precipitation
Hail

- Search for temperatures greater than
- Search for temperature less than

User configuration allows user to search U.S. data only or
search both U.S. and Canadian data.

o Program can be user configured with the following options:

- Define parameter to overlay pressure isobar
- Include or exclude Canadian data in searches
- Specify isobar smoothing passes (minimum of 1,
maximum of 3)
- Toggle on/off 3-D shadowing
- Define time zone
- Define text editor to correct faulty data (public
domain editor provided with WXVIEW)

o Ability to archive and retrieve data sets

Each of these options will be detailed in following sections along with
typical benchmark time tests from various machines.

THE CATCH: The user has to provide his/her own NWS data. In this
modern age of data at your fingertips, this is not a problem unless you
don't have a modem. The three cheapest sources of NWS hourly data I've
found and used are:

- Compuserve ($8.95 per month for basic service)
- Weathermation (free locally if available)
- GTE Contel DUAT (free 800 number)


2.0 THE HISTORY OF WXVIEW

As a professional meteorologist working in the field of industrial air
pollution, I have missed working with real weather forecasting and
observation (the first love of all meteorologists). As such, WXVIEW
was born in 1986 as a BASIC program which reformatted NWS surface
airways (SA) data and plotted the basic parameters on rough regional
maps. With the desire to expand capabilities and increase speed, the
BASIC program was scrapped and re-written in a combination of Microsoft
Quick C and Microsoft Assembler. Originally intended for my own self-
gratification as a meteorological hobby, I shared it with friends in
the NWS and various state Departments of Natural Resources with whom I
associate. Through their encouragement and the fact that there are few
comparable shareware programs, it is now released as a low cost program
to others who also love having up-to-the-minute weather access.

3.0 RETRIEVING THE NWS DATA SET

I am assuming that the user has a modem and is familiar with the fine
art of telecommunications and text data capture. If this is a false
assumption, the user must learn telecommunications before this program
will be of any use.

There are many sources of NWS and Canadian weather data. As mentioned
in Section 1.0, the three cheapest sources of data I know are:

o Compuserve - The basic service price of $8.95 per month
allows unlimited access to NWS hourly surface airways data
(SA) and digital radar data (SD). From within Compuserve,
type GO AWX to get to the aviation weather menu. This is the
service I use most frequently.

o Weatherbrief - This is a free dial-in service provided by
many state's Bureau of Aviation for pilots. All SA and SD
data for U.S. and Canada are available.

o GTE Contel DUAT - This is provided by a toll free number (1-
800-767-9989). Although all SA and SD data are available,
data must be retrieved on a state-by-state basis. This pilot
service is also free but the most time consuming service.

After getting into your NWS data source, turn on the text capture
ability of your communications program. By entering a SA or SD
command, hourly data will be displayed and captured to a file on your
local disk. For example, SA MN,IA,WI will display surface data for
Minnesota, Iowa, and Wisconsin while entering SD MN,IA,WI will display
digital radar for Minnesota, Iowa, and Wisconsin. Within the
Compuserve database, entering SA US will display data for the entire
U.S. Entering SA @ALL will trigger all data for all North America.
Entering SD US will display all digital radar data readings from the
U.S.

I have macros set up within my telecommunications program to specify
the 48 continental states, Canadian border provinces, and U.S. digital
radar. Use of macros makes data retrieval very easy.

The NWS takes SA hourly readings at approximately 5 to 10 minutes
before each hour. The accumulation of all SA data gives a 'snapshot'
of the weather at that moment in time. Typically, the SA data is
available for download at 10 to 15 minutes after the hour. Canadian
data usually is available around half past the hour.

The data retrieved in the SA format is interpreted from its raw format
in the following manner.

Weather & Visibility Codes Prefixes Suffixes
------------------------- --------- --------
hAil drizzLe Blowing shoWers
Dust saNd freeZing + heavy
Fog Rain - light
Ground Fog Snow ++ very heavy
Haze Snow Grains
Ice Crystals Snow Pellets
Ice Fog Thunderstorms
Ice Pellets spraY
smoKe freeZing Rain
shoWer

Cloud Abbreviations Ceiling Prefixes
------------------------------------- ----------------
CLR CLEAR: <10% sky cover E-Estimated
SCT SCATTERED: 10-50% sky cover M-Measured
BKN BROKEN: 60-90% sky cover W-Indefinite
OVC OVERCAST: >90% sky cover V-Variable
- THIN (prefix)
X OBSCURATION: sky obscured
-X PARTIAL OBSCURATION: sky partially obscured


Example:

LGA SA 1352 15 SCT M25 OVC 1R-F 132/58/56/1815G21/993/R28LVR20

LGA = LaGuardia SA=regular hourly Surface observAtion
[SP=special]
1352 = time of observation 13:52 UCT [EDT+5; EST+4]
15 SCT = scattered clouds 1500' above ground(airport) elevation
M25 OVC = overcast clouds measured at 2,500 AGL
1R-F = visibility 1 statute mile, with restriction to
visibility identified as light rain and fog
132 = barometric pressure in millibars=1013.2
58/56 = temperature / dew point in F
1815G21 = wind from 180 degrees magnetic at 15 knots; peak gust 21
R28LRV20 = runway 28 left visual range 2000 feet


The data retrieved in the raw SD format is decoded in the following
manner.

Format:
Station ID/time/location intensity azimuth and range/movement/
tops/precipitation type-intensity trend/remarks/end

Example: NYC 1930 AREA 2 TRW++/+ 297/130 152/115 160W C2620
MT 300 AT 254/39 HAIL REPORTED THIS CELL

NYC RADAR 1930 UCT; AREA OF ECHOES 2/10 COVERAGE, VERY HVY
THUNDERSTORMS FROM 297 DEGREES/130 NM TO 152 DEGREES/115 NM; AREA IS
160NM WIDE;MAX TOP 30,000' AT 245 DEG/39NM; RMKS PLAIN LANGUAGE;

Intensity Decoder

Level Echo Intensity Precip Intsy Rainfall Rate
----- -------------- ------------- -------------
1 Weak None or light <.1-.2
2 Moderate Moderate .1-1.1
3 Strong Heavy .5-2.2
4 Very Strong Very Heavy 2.2-4.5*
5 Intense Intense 4.5-7.1*
6 Extreme Extreme >7.1 in/hr
*= only in convective situations
8 Unknown but associated with severe wx
9 Unknown

Abbreviations
-------------
HOOK - signature "tail" usually associated with tornadoes
HAIL - radar indicated hail
LINE - echoes are in a line
LEWP - Line Echo Wave Pattern - wavy line
FNLN - FiNe LiNe; narrow non-precipitation echo pattern
BWER - Bounded Weak Echo Region - echo free vault within a cell
ALFT - precipitation ALoFT
MALF - Mostly ALoFt precipitation
PALF - Partly ALoFt precipitation
MLVL - Melting LeVeL; radar detection of melting of frozen precip
PCLL - Persistent CeLLs
SLD - SoLiD areas of 80% or more

PPINE - equipment normal; No Echoes
OM - inOp or out of service for Maintenance
NA - observation Not Available
NS - equipment normal; No Significant echoes
ROBEPS Radar Operating BElow Performance Standards
ARNO - Azimuth Range indicator iNOperative
RHINO - Radar Height Indicator iNOperative

Note: above SA and SD decoding information was taken from the
Compuserve file WXDECO.TXT.

The NWS radar stations take the SD digital radar reading at
approximately 25 minutes past the hour. It is usually available for
download at 45 minutes after the hour.

The provided file 'DEMO.DAT' is a demonstration file of a Compuserve
retrieval session which captures the 48 continental states, Canadian
border provinces, and U.S digital radar. THE PROVIDED DEMONSTRATION
DATA FILE IS ENCODED TO WORK 100% WITH WXVIEW. DATA DOWNLOADED BY THE
USER WILL HAVE LIMITED GRAPHIC CAPABILITIES.

4.0 RUNNING WXVIEW
Simply enter the command "WXVIEW" to begin the program. The following
files must be present in the local directory for WXVIEW to run
properly:


WXVIEW.EXE - Executable program file
WXVIEW.FIG - Configuration file
WXCITY.NAM - Available station names and NWS codes
WXNATL.CRD - Station coordinates for national map
WXNATL.BIN - National map file (binary format)
WXZOOM.CRD - Station coordinates for zoom map
WXZOOM.BIN - Zoom map file (binary format)
WXRADAR.CRD - Station coordinates for digital radar
WXVIEW.SA - Current formatted SA surface data set
WXVIEW.SD - Current formatted SD radar data set

Other files included but not critical to the program are:

WXVIEW.PRS - Current isobar grid array
WXVIEW.DOC - Documentation file (what you are reading)
TED3.COM - Public domain text editor. May be substituted for
user's choice editor in program configuration
option.
DEMO.DAT - Demonstration raw data which is encoded to be 100%
operational for demonstration purposes.
WXVIEW.SA, WXVIEW.SD and WXVIEW.PRS bundled with
the program were generated by formatting this demo
data set. User supplied data will have limited
use in the graphic display section.

After entering the WXVIEW command, the WXVIEW program will present a
title screen while loading configuration. During configuration
loading, the program loads all city names, coordinates, and user
configuration data into memory. Time to load varies with the type of
computer used. Typical loading times are as follows:

8Mhz 286 w/coprocessor 25 Mhz 386 wo/coprocessor 25 Mhz 486

7 sec 2 sec 1 sec


Use the cursor keys to highlight the desired choice and then press
enter key.

4.1 Reformatting NWS data set

THIS OPTION MUST BE PERFORMED BEFORE WXVIEW CAN VIEW OR SEARCH ANY USER
DOWNLOADED NWS DATA.

To analyze or display the NWS data in the fastest, most efficient
method, the rough format of the SA and SD raw data is formatted to a
column oriented format. This format is easily readable by the WXVIEW
program and any other database management program requiring column
oriented text data. The data is formatted into the following format:
Parameter Start column Stop column

NWS city code 1 3
Greenwich mean time 5 8
Current weather 10 17
Visibility (Statute miles) 18 21
Abbreviated pressure (millibars) 24 26
Temperature (Degrees Fahrenheit) 28 30
Dew Point (Degrees Fahrenheit) 32 34
Wind direction/Wind speed (Deg/Knots) 37 40
Abbreviated altimeter (inches) 42 44
Cloud cover 47 80


This option reads ALL valid NWS/Canadian SA data, formats it and stores
the results in a temporary file. An on-screen counter informs the user
of how many observations are being formatted. During the formatting
step, WXVIEW determines which hour has the most observations. The
temporary file is re-read and ONLY observations for that hour are
written to the final file (WXVIEW.SA). An on-screen counter keeps
track of how many observations are written to the final file. If
several observations are reported for a single station during the same
hour, WXVIEW accepts the first observation read in the raw NWS data
file and ignores the rest.

A vigorous error screening protocol is applied to the final WXVIEW.SA
data set. If WXVIEW suspects an error in a station observation for the
valid hour, that observation is rejected and written to an alternate
file named BAD.OUT. The user may wish to review this file and apply
corrections if desired. The user is prompted to press a key after the
SA data set is processed. A similar process to format the SD digital
radar set follows.

The internal computer system date is used to date stamp the formatted
WXVIEW.SA file. The observation date and Greenwich mean time make up
the first line of WXVIEW.SA and WXVIEW.SD.

Formatting a NWS data set need not be repeated until a NEW data set
is downloaded.

Typical times to reformat SA and SD data from the 48 states and 9
Canadian border provinces are:

8Mhz 286 w/coprocessor 25 Mhz 386 wo/coprocessor 25 Mhz 486

1 min 34 sec 20 sec 15 sec


The user is recommended to download both the SA and SD data into the
same file. However, if the user wishes download just the SA or just
the SD data, WXVIEW will preserve the last formatted session of the
non-downloaded parameter.

Please note that temperature and dew point in the downloaded Canadian
weather data are in degrees Celsius. These data are converted into
degrees Fahrenheit in all WXVIEW displays and text searches.
Also note that ALL NWS/Canadian wind speeds are in knots. All wind
speeds are converted to miles per hour (mph) for graphic wind staff
displays and text searches.

4.2 View the Graphic Data Set

The WXVIEW program works 100% with the provided demo data set.
HOWEVER, FOR USER SUPPLIED DATA, ONLY THE FIRST 15 STATIONS IN THE
VIEW AREA ARE GRAPHICALLY DISPLAYED.

This is the only limitation between the demo version and the registered
version. You must order a registered copy of WXVIEW to get the fully
functional version.

When chosen, this option graphically displays the last formatted or
retrieved data set. WXVIEW will take a few seconds (depending on
machine speed) to load applicable station data into memory. Expected
times to load the national data set are as follows:

8Mhz 286 w/coprocessor 25 Mhz 386 wo/coprocessor 25 Mhz 486

20 sec 4 sec 2 sec

The national data array is loaded into memory only once per WXVIEW
session unless the current data set is edited or a new data set is loaded.

If this is a NEW data set or an EDITED data set, WXVIEW will attempt to
grid pressure data for isobar plotting. The grid array contains 31 x
25 grid points. Depending on the type of machine used and whether or
not a math coprocessor is used, this can be a time consuming ordeal.
Expected times are as follows:

8Mhz 286 w/coprocessor 25 Mhz 386 wo/coprocessor 25 Mhz 486

1 min 57 sec 1 min 31 sec 10 sec


The isobar plotting option can be aborted by pressing the escape (ESC)
key. Smoothing passes to 'iron out' the rough edges of the isobar
plots are determined in the user configuration section. Gridding needs
to be done only once per data set unless the user edits the formatted
data file. If reviewing previously gridded data, isobar gridding will
not be redone. Note: if there is less than 100 stations in the SA data
array, WXVIEW will NOT grid data or plot isobars due to insufficient
data.

After the pressure gridding routine is completed, aborted, or skipped
(if previously gridded), WXVIEW displays the national weather map with
current observations and the first menu bar. The two menu bars are
toggled by the  (up) and  (down) cursor keys. Any menu option can be
chosen by moving the cursor and pressing enter or instantly chosen by
pressing the displayed 'hot key' for that option.
Menu Bar 1 options:

OBS - Current weather in the same code as provided in the raw
NWS data set.

SKY - Cloud cover. Clear circle indicates clear skies. Blue
in upper right quadrant indicates scattered cloud cover.
Orange covering 2/3 of circle indicates broken cloud
cover. Dull white in all or part of circle indicates
overcast. Combinations of cloud covers can occur.
Number appearing below circle for broken and/or overcast
skies is cloud base in hundreds of feet (i.e. 250
implies cloud base at 25,000 ft). Circle with an 'X'
indicate obscured sky.

VIS - Visibility in statute miles. Fractional distances are
interpreted in the following manner: 11/2 indicates 1
and 1/2 statute miles.

PRESS - Pressure in millibars. If pressure gridding was
completed for a data set, isobars are drawn. Isobars
are spaced four millibars apart (ranging from 950 to
1054) and are not labeled. The default overlay is
numeric pressure in millibars but can be changed in the
configuration option. Highs and lows are calculated
from the pressure grid and displayed. Positioning of
the highs and lows are approximate due to grid spacing.
The best way to identify the EXACT position of a low
pressure system is to check the wind field. If the
isobar gridding option was aborted, only numeric
pressure in millibars is displayed.

When displaying the isobar plot on the national map,
isobars are 'flashed' off the Atlantic, Pacific, and
Mexican areas. No stations are plotted for these areas
so isobar gridding is erratic and unrepresentative.

TEMP - Temperature in degrees Fahrenheit. Color of temperature
display changes every 10 degrees to provide quick color
overview of the temperature pattern.

DEW - Dew point in degrees Fahrenheit. Color of dew point
display changes every 10 degrees to provide quick color
overview of the dew point pattern.

WIND - Wind direction and wind speed are graphically displayed
as wind flags similar to those found on NWS maps. The
flags can be thought of as arrows pointing in the
direction the wind is blowing toward. Each full barb on
the wind flag represents 10 mph of wind speed (there is
a conversion in the wind data from knots to mph, 1 knot
equals 1.15 mph). With limited pressure grid spacing,
the wind field is the best way to locate the center of
a low pressure system. A strong low, in a field of wind
flags, can resemble water going down the drain. At the
center of the swirl is the low.

If zero winds (calm) are reported for a station, a small
zero is placed at the station location.

RADAR - Digital radar. Color indicates precipitation intensity
as shown on top of screen bar. User will need to press
any key after viewing to return to menu bar. Digital
radar data can overlap if reporting radar stations are
in close proximity to each other.

Since SD radar readings occur approximately 30 minutes
after the SA surface observation, radar and current
weather may not always agree.

CITY - Display all available NWS and Canadian stations
available for graphic display.

EXIT - Return to previous menu.


Menu Bar 2 options:

ZOOM - Available from national map only. Zoom box appears in
center of U.S. map. Move box in straight line or
diagonally with cursor keys to desired zooming location.
Press enter key. WXVIEW will take a few seconds (about
the same time it takes to load the national map) to load
data from the zoom area stations into memory. All
available NWS and Canadian stations are displayed in the
zoom mode to provide better resolution of the mesoscale
weather picture.

Only one level of zooming is allowed.

GROUP - Available from the zoom map only. This option is for
those who want it all on one screen. All reported
parameters in the SA data set are reported on one
screen. The format of the layout for each station is as
follows:

(temp) (pressure (abbreviated))
(current weather) (sky) (visibility (miles))
(dew pt) (cloud base (hundreds of ft))

In congested areas with many readings, station data may
overlap to the point of being unreadable, however, in
many areas this is a good way to get an overall picture
of mesoscale weather.

RELATIVE
HUMIDITY- Relative Humidity in percent. Color of percentage
changes every 10 degrees to provide quick color overview
of the relative humidity pattern.

WIND
CHILL - Wind chill temperature in degrees Fahrenheit. Color of
wind chill temperature changes every 10 degrees to
provide quick color overview the wind chill temperature
pattern. Wind chill is NOT calculated if wind speed is
3 mph or less. Wind chill is also NOT calculated when
ambient temperature is 60 degrees or greater.

Algorithms to calculate the relative humidity and wind
chill were gratefully received from Mr. Dan Noah of the
Madison, WI National Weather Service.

APPARENT
TEMP. - Apparent temperature in degrees Fahrenheit. The NWS has
adopted the apparent temperature index (heat index) as
a summertime measure of sultriness. Color of apparent
temperature changes every 10 degrees to provide quick
color overview the apparent temperature pattern.
Apparent temperatures are NOT calculated when ambient
temperature is less than 60 degrees.

The algorithm for the apparent temperature calculation
was obtained from the August 1985 Weatherwise magazine.

Pressing the escape (ESC) key or pressing the 'E' key will return the
user to the previous menu.


4.3 WEATHER EVENT SEARCH

This section of the WXVIEW program allows the user to search the
weather data by several criteria and receive an expanded version of
station data in easy to read text. Matches to the search criteria are
displayed in half screen segments while prompting the user to press a
key to continue. When the next search match is found, the top screen
information is scrolled down to the bottom half screen.

The user can only search forward through the data (i.e. you can not
back up and review data which have already scrolled of the screen).

The user can break away at any time between search matches by pressing
the escape (ESC) key or the 'E' key.

The various search criteria are detailed in the following subsections.

4.3.1 Search by City of NWS Code

The user is prompted for an entry. For example, if the user
wishes to review the weather for Nashville, TN (NWS code is BNA),
the user can type either BNA or an abbreviated part of the name
'Nashville' (i.e. Nash). If the user is typing an abbreviated
portion of the city name, it must be the beginning portion of the
name. WXVIEW does not perform imbedded text searches.

User entry can be in either upper or lower case.

All matches fitting the entry will be displayed until no more
matches are found or the user aborts the search. If no match is
found in the city/code database, the user is notified. If an
entry match is found in the city/code database but no data is
found in the current weather file, the user is also notified.

This option includes data search for Alaska and Hawaii stations.
If the user has chosen to allow Canadian data to also be searched
(in the configuration section), Canadian city/code matches will
also be displayed.

4.3.2 Search by State

The user is prompted for a 2 letter state abbreviation. Entering
TN will display all matches for the state of Tennessee. If the
user has chosen to allow Canadian data to also be searched,
entering a 2 letter Canadian province will allow the provinces
data to be displayed (i.e. MB for Manitoba).

User entry can be in either upper or lower case.

4.3.3 Search by Extremes

This option will search the entire database (including or
excluding Canadian data depending on user configuration) for
weather extremes and list them on a single screen display.
Parameters searched and displayed are: highest temperature, lowest
temperature, highest wind speed, highest pressure, and lowest
pressure. Also displayed are any stations listing heavy
precipitation.

If more than one station reports the same extreme or heavy
precipitation, the additional stations are also listed (up to six
stations).

4.3.4 Search by Precipitation

The user can search the data for stations reporting specific
precipitation. The precipitation choices available for search
are: Rain, Snow, Drizzle, Thunderstorm, Ice, Freezing
precipitation, and Hail. If no stations report the searched
event, the user is returned to the precipitation menu.

4.3.5 Search for Temperatures Greater Than

WXVIEW will search and display all stations reporting a
temperature greater than or equal to the value entered by the
user.

4.3.6 Search for Temperatures Less Than
WXVIEW will search and display all stations reporting a
temperature less than the value entered by the user.


4.4 SAVE/REVIEW WEATHER DATA

Occasionally, a viewed map is special because of some significant
weather event. The user has the option to save the current map and
retrieve it for later viewing. The user is prompted to enter 'S' to
save the current file, or 'R' to retrieve an archived file. If 'S' is
chosen, the user is prompted to enter a filename (without any
extension). The files saved to disk will be:

filename.SA - Saved SA data
filename.SD - Saved SD digital radar
filename.PRS - Saved isobar grid (if grid was created)

Do not use the name WXVIEW to archive because these are reserved
filenames.

If retrieving an archived file using the 'R' option, the user is
prompted to enter a filename (without any extension). If the files do
not exist, the user is notified.

WXVIEW does not provide any means to delete archived files or do a
directory search. The user can easily delete unwanted archive files
from the DOS prompt by entering 'DEL filename.*' (using the correct
filename, of course).

4.5 EDIT CURRENT DATA SET

Occasionally bad data gets through the screening routine during the
formatting of raw NWS data. One of the most frequent I've seen is
faulty pressure data which can result in bizarre isobar plotting. If
the faulty station can be identified, the user can use this editing
option to correct or delete the faulty data.

A public domain text editor has been included with WXVIEW to serve this
purpose. This editor (TED3 for tiny editor version 3.0) is limited to
files less than 64K in size. To work, the formatted SA data file,
WXVIEW.SA, must be less than 64K. If you have downloaded just the 48
states and border provinces of Canada, the formatted WXVIEW.SA should
be less than 64K. If you have downloaded the entire North American
database (i.e. entered SA @ALL in Compuserve), the formatted file may
be larger than 64K.

After exiting the text editor, the user is prompted whether or not to
re-grid the pressure data when attempting to graphically display data.
If pressure data has not been changed, there is no need to repeat the
gridding process. WXVIEW will assume some data has been changed and
will re-load the national data array before displaying any maps.

The user can opt to substitute his/her own favorite text editor in the
user configuration section.
If there is not enough remaining memory to load the text editor or the
WXVIEW.SA is larger than 64K (using the TED3 editor), editing is
aborted and the user is immediately returned to the menu.

CAUTION: Do not edit the demonstration file 'DEMO.DAT'. This file has
been encoded to allow for 100% use in the demonstration version of
WXVIEW. Editing may disrupt the encoding.

4.6 CONFIGURE PROGRAM

WXVIEW has several user configurable options as detailed in the
following subsections.

4.6.1 Change U.S. Isobar Overlay Option

The default isobar overlay parameter at the beginning of each
WXVIEW session is the numeric pressure in millibars. At times it
is interesting to overlay a different parameter on the isobar
field. Available overlay parameters are: Wind direction/speed
flags, cloud cover, temperature, current weather, and digital
radar.

4.6.2 Weather Event Search on US/Canadian Data

The user can choose to include or exclude Canadian data in the
weather search option. For example, Canadian data almost always
generates the low temperature reading during the extremes search.
If you don't want to see this, you can switch off Canadian data
search by toggling this menu option. Pressing enter when this
option is highlighted will toggle the choices.

4.6.3 Isobar Grid Screening Passes

The pressure isobar gridding usually produces a rough isobar plot.
By sending the pressure grid through a 'smoothing' routine, the
contours can be somewhat smoothed for a more realistic appearing
isobar plot. The user can specify a minimum of one (1) to a
maximum of three (3) smoothing passes.

If this option is chosen, then WXVIEW will attempt to re-grid the
pressure data when the graphic display option is again chosen.

4.6.4 Toggle 3-D Shadow

The user has the option to view graphically displayed data in a
simulated 3-D effect. The 3-D effect appears to have the data
raised off the screen leaving a shadow. If this effect is not
desired, it can be toggled on/off with this option. Pressing
enter when this option is highlighted will toggle the choices.

4.6.5 Change Time Zone

The graphic maps and search display screen list the local time of
observation. The user can change the displayed time zone to match
the local time zone. Preprogrammed zones are EST, EDT, CST, CDT,
MST, MDT, PST, and PDT. Any other option will result in a prompt
to enter the number of hours to offset from Greenwich mean time.

4.6.6 Select Text Editor

A public domain text editor has been included with WXVIEW to serve
this purpose. This editor (TED3 for tiny editor version 3.0) is
limited to files less than 64K in size. To work, the formatted SA
data file, WXVIEW.SA, must be less than 64K. If you have
downloaded just the 48 states and border provinces of Canada, the
formatted WXVIEW.SA should be less than 64K. If you have
downloaded the entire North American database (i.e. entered SA
@ALL in Compuserve), the formatted file may be larger than 64K.

The user can, through this configuration option, choose a
different text editor other than the TED3 public domain editor
included with this software. The user must choose a text editor
such as QEDIT and not a word processor such as WordPerfect.

4.7 EXIT

Every program should have a challenge, therefore, I'll leave this one
for everyone to figure out on their own.

5.0 DISCLAIMER

As dictated by current social protocol, I am not responsible for any of
my actions. Therefore, you (the user) assume all responsibility for
using this program. In other words, if you fly your airplane into the
side of a mountain, please don't blame me. What you see is what you
get with this program. My personal intent with this program is to have
fun and satisfy my need to keep up with the current weather. Your end
use of this program is your business.

6.0 OBTAINING A REGISTERED COPY

You are encouraged to share this demonstration version with your
friends. So as not to violate the first law of thermodynamics (there
is no such thing as a free lunch), there is a one time registration
cost associated with this program. All users MUST register if you plan
to use this demonstration program beyond 30 days. With registration
comes the fully functional version of WXVIEW (remember, the demo
version has limited graphic use with user supplied data).

In the true sense of shareware ideology, I will keep the registration
cost at a minimum to encourage wide use of this program. To achieve
this objective, documentation is provided ON DISK rather than a printed
copy. I will assume that if you have a modem, you probably splurged
and bought a printer or, at least, have access to one.

I have not found any similar software (even with less capabilities)
costing less than what I am asking for WXVIEW. If you agree and wish to
receive a registered copy, please remit the following:

Cost $25.00 Fully functional version 2.4 of WXVIEW
$4.95 Shipping and handling
------
$29.95 Total


Please send check or money order (no cash, credit card numbers, or
trading stamps) to:

Jim Haywood
2157 Forest Hill SE
Grand Rapids, MI 49546

I will send your disk out via the U.S. mail within two days of
receiving your order. Unless specified to the contrary, all orders
will be provided on a 5.25" diskette. I will follow up with a post
card notice a few days later to inform you that your disk has been
mailed.

THE REGISTERED VERSION OF WXVIEW IS NOT TO BE SHARED OR DISTRIBUTED.
I will trust your conscience and honesty not to share or distribute
your registered copy.

Since you will have a chance to completely review WXVIEW capability
with the demo data, you know what you are getting and there will be NO
refunds.

Feel free to contact me with any suggestions or comments through
CompuServe, 72247,2072. If you are a Compuserve user, please include
your user number so I can contact you with updates, new programs, etc.

7.0 FUTURE PLANS

I used up all the available memory in writing WXVIEW, therefore there
will probably be no significant upgrades to WXVIEW other than minor
tweaking and bug fixes. My next goal is to write software for upper
air analysis with data provided by the FDLO and FDHI options.