174 lines
8.6 KiB
HTML
174 lines
8.6 KiB
HTML
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<html>
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<meta http-equiv="CONTENT-TYPE" content="text/html; charset=utf-8">
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<title>Enhanced_Wx</title>
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<body dir="ltr" lang="de-DE" text="#000000">
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<font face="New Century Schoolbook, Times New Roman, serif"><font
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size="5"><b>Enhanced_Wx</b></font></font>
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<br>
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<br>
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<font face="New Century Schoolbook, Times New Roman, serif"><font
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size="3"><b>Introduction</b></font></font>
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<br>
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<br>
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<font face="New Century Schoolbook, Times New Roman, serif">The Enhanced_WxTool
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is a significant enhancement to the original Wx_SmartTool, which was written.
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Both tools assign Wx based on the corresponding PoP grids; however the
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Enhanced_WxTool offers the following additional functionality:<br>
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<ol>
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<li>The forecaster is allowed considerable freedom in choosing individual
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weather types (RW, R, SW, S, IP, ZR, L, ZL, and F are all supported).</li>
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<li>Up to three weather types may be mixed together and a different
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intensity (very light [--], light [-], moderate [m], or heavy [+]) may be
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assigned to each. So for example, it is possible to assign weather such
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as RmSmIP- with this tool.</li>
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<li>The forecaster can also choose whether to include thunder (T)
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with any other supported weather type; if thunder is included, he or she also
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has the option of specifying whether the thunder is severe in nature (T+).</li>
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<li>The forecaster can assign either probability qualifiers or areal coverage
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qualifiers (where allowed) to the chosen weather types. If a forecaster attempts
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to use an invalid qualifier for a weather type, the tool will generate an error
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message appears indicating that this is not allowed.</li>
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<li>For each individual weather type, the forecaster can override the default
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probability/coverage obtained from the PoP grid if desired. The same is also true
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for thunder (T). This makes it possible to: create weather combinations such as
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“Lkly RW:Chc SW” or “Def RW:Chc T”; and assign weather types of F, L, or ZL,
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which aren’t necessarily derived from the PoP grids.</li>
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<li>For categorical PoPs, the forecaster can use alternate probability/coverage
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terms (other than "Def" or "Wide") if desired. The following options are
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available: "Ocnl", "Frq", "Brf", "Pds", and "Inter". When used, this setting
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applies to all categorical precip coverages that are derived from the PoP grid.</li>
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<li>If thunder is included with the precipitation, the forecaster also has the
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additional option of specifying the following thunderstorm attributes, if
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desired:</li>
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<ul>
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<li>Small Hail (SmA)</li>
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<li>Heavy Rain (HvyRn)</li>
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<li>Gusty Winds (GW)</li>
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<li>Frequent Lightning (FL)</li>
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<li>Large Hail (LgA)</li>
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<li>Damaging Winds (DmgW)</li>
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<li>Tornadoes (TOR)</li>
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</ul>
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</ol>
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<br>
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The tool is designed so that the last three attributes (LgA, DmgW, and TOR) can only be
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assigned when severe thunderstorms (T+) are forecast. Similarly, the tool will also
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only allow SmA and GW to be used with non-severe thunderstorms (T). If the forecaster
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tries to assign a thunderstorm attribute that is invalid, the tool will display a
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message indicating this, and will automatically ignore such attributes and run to
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completion.
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<br><br>
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It should be noted that the tool does not apply any scientific principle to derive
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the final Wx type; the Wx type assigned is solely decided upon by the forecaster.
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The forecaster chooses the Wx type through the use of a GUI interface that appears
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when the tool is executed.</font>
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<br>
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<br>
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<br>
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<big><big><font style="font-weight: bold;"
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face="New Century Schoolbook, Times New Roman, serif">How
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the Procedure Works</font><span style="font-weight: bold;">
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</span></big></big><br>
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<br>
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<font face="New Century Schoolbook, Times New Roman, serif">The floating PoP grids for the time
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period in question must exist before running the tool. After creating all of the necessary
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floating PoP grids, to run the tool the forecaster needs only to select the BUF_WxTool from the
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list of available smart tools in GFE; this action brings up the following GUI:<br><br>
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<img alt="Enhanced_Wx" src="images/Enhanced_Wx.png"></font>
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<br>
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<br>
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<font face="New Century Schoolbook, Times New Roman, serif">Here is a brief overview of each section:
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<br><br>
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Qualifier Type: Allows you to toggle between the use of Probability and Areal Coverage terms.
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The default setting is “Prob”.
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<br><br>
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Alter Terms Cat PoPs (new): Allows you to use alternate probability/coverage terms ("Ocnl",
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"Frq", "Brf", "Pds", and "Inter") when categorical PoPs are used. When used, this setting
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will apply to all categorical precipitation probabilities/coverages that are derived from
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the PoP grid. The default setting is “None”.
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<br><br>
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1st/2nd/3rd Type: Allows you to select/combine up to 3 different weather types.
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In version 2.0, the lists of available weather types have been expanded to include L, ZL, and F.
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<br><br>
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1st/2nd/3rd Inten: Allows you to specify the intensity of each weather type (--, -, m, or +).
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In the case of fog (F), only + (dense) is a valid intensity. If F is selected with any other
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intensity, the tool will automatically remove the intensity to prevent any errors. The default
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setting is “-“ (light).
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<br><br>
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1st/2nd/3rd Type Alternate Prob/Cov (new): Allows you to override the default probability/coverage
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obtained from the corresponding PoP grid for each individual weather type. This allows the easy
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creation of weather types such as "Lkly RW:Chc SW". This approach also allows for the use of
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other weather types (for example, F, L, and ZL) which aren't necessarily PoP-dependent.
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The default setting is “None” - meaning the probability/coverage terms for each weather type
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are derived from the PoP grid by default.
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<br>
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Thunder?: Allows you to specify whether you want thunder included with the other weather type(s)
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selected. Options are “No”, “Yes (T)”, and “Yes (T+)” (severe T). The default setting is “No”.
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<br><br>
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Thunder Alternate Prob/Cov (new): Allows you to specify an alternate probability/coverage for
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T if desired. This setting will override the default probability/coverage obtained from the
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corresponding PoP grid, and makes it possible to create precip types such as "Def RW:Chc T".
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The default setting is “None” - meaning the probability/coverage term for T is derived from
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the PoP grid by default.
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<br><br>
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Tstm Attributes?: Allows you to specify Thunderstorm Attributes if you choose to include
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Thunder in the Wx grid.
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<br><br>
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Once the forecaster has made their selections from the above GUI, he/she then assigns the
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desired weather by clicking either of the Run or Run/Dismiss buttons within the GUI.
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When this is done, a single weather type is created based on the forecaster input. Unless
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specifically overridden by the forecaster, probability or areal coverage qualifiers will
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be determined from the PoP grid in accordance with the following table:<br><br>
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<table border="1" cellpadding="2" cellspacing="2" width="100%">
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<tr>
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<td><b>PoP Value (rounded to the nearest %)</b></td>
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<td><b>Probability Qualifier</b></td>
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<td><b>Areal Coverage Qualifier</b></td>
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</tr>
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<tr>
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<td>0 - SChc_min_PoP_threshold*</td>
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<td>None; <NoWx> is assigned</td>
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<td>None; <NoWx> is assigned</td>
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</tr>
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<tr>
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<td>SChc_min_PoP_threshold* - 24</td>
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<td>Slight Chance (SChc)</td>
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<td>Isolated (Iso)</td>
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</tr>
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<tr>
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<td>25 - 54</td>
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<td>Chance (Chc)</td>
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<td>Scattered (Sct)</td>
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</tr>
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<tr>
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<td>55 - 74</td>
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<td>Likely (Lkly)</td>
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<td>Numerous (Num)</td>
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</tr>
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<tr>
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<td>75 - 100</td>
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<td>Definite (Def)</td>
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<td>Widespread (Wide)</td>
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</tr>
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</table><br><br>
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* - SChc_min_PoP_threshold is the minimum PoP needed for a SChc (slight chance) of weather to
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be included in the Wx grid. This value is site-customizable; the default value is 14.5%.
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Please see the Installation/Configuration section below if you would like to change this
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setting at your site.</font>
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</body>
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</html>
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