441 lines
22 KiB
HTML
441 lines
22 KiB
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<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
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<html>
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<head>
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<meta http-equiv="CONTENT-TYPE" content="text/html; charset=utf-8">
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<title>ERQCcheck</title>
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<meta name="GENERATOR" content="OpenOffice.org 1.1.3 (Linux)">
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<meta name="CREATED" content="19951121;16410000">
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<meta name="CHANGED" content="20050706;13040400">
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<style>
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@page { size: 8.5in 11in; margin-right: 1.25in; margin-top: 1in; margin-bottom: 1in }
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P { margin-bottom: 0.08in; direction: ltr; color: #000000; text-align: left; widows: 0; orphans: 0 }
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P.western { font-family: "Bitstream Vera Serif", "Times New Roman", serif; font-size: 12pt; so-language: en-US }
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P.cjk { font-family: "Bitstream Vera Sans"; font-size: 12pt; so-language: }
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</style>
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</head>
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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>ERQCcheck</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">Due to the increasing number of elements
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and their forecast projection which must be produced, it has been difficult to keep track of all the
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data in all the grids. There is a need for methods to assist in the managing of these grids in a
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timely fashion.
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<br><br>
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One of the many challenges forecasters have is making sure all the grids are consistent with one
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another (i.e. Td < T). With all of the different elements and their interrelationships, if the
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data is not inspected carefully, glaring inconsistencies may show up. Another challenge is making
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sure all grids required for NDFD are actually there, especially in the morning when the new day 7
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needs added.
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<br><br>
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ERQCCheck is designed to assist in these areas. It allows one to cross check elements against one
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another to assure consistency. Where inconsistencies are found, the forecaster has the option to
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either just see where the inconsistencies are, or have one element or the other forced so that they
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are consistent.
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<br><br>
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It also includes a routine that check for the existence of grids required for NDFD. This routine
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checks for the various weather elements required for the time intervals required, over the seven days.
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It accounts for the different time intervals required for the different elements, or for the same
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elements over different time ranges. For example, many elements are required at three hour
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intervals out to 48 or 60 hours, then every six hours out through day 7.
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<br><br>
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The following table lists the Procedures and Tools used, and which elements the Tools check.
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The first column lists all the Procedures and Tools. In addition to the master Procedure,
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ERQCCheck, there are 2 Procedures within the Master Procedure, one being
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CheckTandTd Procedure, which also deals with MaxT and MinT, the other being the NDFDgridCheck
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procedure.
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<br><br>
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The tools are used directly by the master Procedure for all the other elements; each Procedure or
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Tool used by the master Procedure is indented once. Procedures are so indicated in the second
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column; all others are Smart Tools. The weather element edited by the Smart Tool is listed in the
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third column.
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<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>Procedure or Tool</b></td>
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<td><b>Procedure</b></td>
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<td><b>Tool (Wx Element Edited)</b></td>
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</tr>
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<tr>
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<td>NDFDgridCheck</td>
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<td>Procedure</td>
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<td></td>
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</tr>
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<tr>
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<td>CheckTandTd</td>
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<td>Procedure</td>
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<td>T and Td</td>
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</tr>
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<tr>
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<td>SnowAmtQPFPoPWxCheck</td>
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<td>Procedure</td>
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<td></td>
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</tr>
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<tr>
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<td>CheckWindGust</td>
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<td>Procedure</td>
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<td>Wind Gust</td>
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</tr>
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<tr>
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<td>CheckSkyWithPoP</td>
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<td></td>
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<td>Sky</td>
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</tr>
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<tr>
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<td>EnufCloudForPoP</td>
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<td></td>
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<td>Cloud</td>
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</tr>
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<tr>
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<td>WindChillTool</td>
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<td></td>
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<td>Wind</td>
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</tr>
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</table><br><br>
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</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">From the consistency menu, choose
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ERQCcheck. Note that we are checking for internal inconsistencies, those found among one’s own
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forecast grids, not inconsistencies between one’s own forecast and their neighbors forecast grids.
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After selecting the procedure a GUI will appear:<br><br>
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<img alt="ERQCcheck" src="images/ERQCcheck.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">The top section deals with selecting a
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time range over which to check grids. To check grids over the selected time range in the grid
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manager, just leave “Y” for “Use Selected Time Range from the Grid Manager.” To check for certain
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periods, like Day4 or Day3 night to Day7, select “N” for “Use Selected Time range” and choose the
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time periods at the right; the time to start with from the left column, and to end with from the
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right. To check for Day4 only, for example, just choose Day4 for the start and end time.
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If checking all the grids through time, simply pick the first period in the left column (Today
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or Tonight) and Day 7 from the right column.
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<br><br>
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The column to the right allows one to choose which cycle one is on. This affects the time periods
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chosen, as the day references change meaning from the 00Z to the 12Z cycle. Leaving the default,
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“Auto,” will result in the cycle being automatically determined by ERQCcheck, so one need not worry
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about this feature at all in most cases. However, the other two choices, one for each off the two
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possible cycles one is on, are left available in case the Procedure doesn’t determine the desired
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cycle right, such as during a borderline part of the day.
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<br><br>
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Next are the options for what to check, and whether to highlight only or actually fix. For each
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weather element, one can choose whether to fix or just highlight where it is inconsistent with the
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element it is being checked against. On the Wx check, just the highlight option is available,
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although a fix option has been written, and will soon be added. On the WindGust check, just the
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fix option is available at this time. The following table shows what elements can be checked
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(Dependent Element), what element(s) they are checked against (Independent Element), and outlines
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the options are available for each element.<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>Dependent Element</b></td>
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<td><b>Independent Element</b></td>
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<td><b>Highlight</b></td>
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<td><b>Fix</b></td>
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</tr>
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<tr>
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<td>MinT</td>
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<td>Previous MinT</td>
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<td>Yes</td>
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<td>Yes</td>
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</tr>
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<tr>
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<td>MaxT</td>
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<td>Previous MaxT</td>
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<td>Yes</td>
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<td>Yes</td>
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</tr>
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<tr>
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<td>T</td>
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<td>MaxT, MinT</td>
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<td>Yes</td>
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<td>Yes</td>
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</tr>
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<tr>
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<td>Td</td>
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<td>T</td>
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<td>Yes</td>
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<td>Yes</td>
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</tr>
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<tr>
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<td>RH, Heat Index</td>
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<td>T, Td</td>
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<td>Yes</td>
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<td>Yes</td>
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</tr>
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<tr>
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<td>WindGust</td>
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<td>Wind, WindGust rules</td>
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<td>No</td>
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<td>Yes</td>
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</tr>
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<tr>
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<td>Sky</td>
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<td>PoP</td>
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<td>Yes</td>
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<td>Yes</td>
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</tr>
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<tr>
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<td>PoP</td>
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<td>Sky</td>
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<td>Yes</td>
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<td>Yes</td>
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</tr>
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<tr>
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<td>PoP</td>
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<td>Wx</td>
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<td>Yes</td>
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<td>Yes</td>
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</tr>
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<tr>
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<td>Wx</td>
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<td>PoP, PoP12hr</td>
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<td>Yes</td>
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<td>No</td>
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</tr>
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<tr>
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<td>PoP12hr</td>
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<td>PoP</td>
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<td>Yes</td>
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<td>Yes</td>
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</tr>
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<tr>
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<td>QPF</td>
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<td>PoP</td>
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<td>Yes</td>
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<td>Yes</td>
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</tr>
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<tr>
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<td>SnowAmt</td>
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<td>PoP</td>
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<td>Yes</td>
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<td>Yes</td>
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</tr>
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</table><br><br>
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</font>
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<font face="New Century Schoolbook, Times New Roman, serif">Note that leaving the defaults will
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result in no action being taken by the Procedure at all. One must either pick an All option,
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or one or more of the options that follow.</font>
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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">Brief Synopsis of each option: What
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ERQCcheck does</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">What follows is an explanation of the
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procedure and/or tool(s) behind each option and what they do. For the highlight option, temporary
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grids are created and displayed at the bottom of the grid manager (but above the ISC grids, if
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loaded). The grid name is the Element name prefixed with “Invalid,” Invalid[Element], such as
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InvalidPoP. For the temperature checks, the grid names are something to the effect:
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TgreaterThanMaxT.
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<br><br>
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Usually, the highlight grids will be purple over areas that are OK, and red over areas where the
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value for that element is not consistent with the element it was checked against. A grid of
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zeroes and ones is produced. The purple area will have a value of 0, indicating OK, and the red
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area a value of 1, indicating an inconsistency, but not by how much.
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<br><br>
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Only the ISC_Send area is checked, so the forecaster is not bothered with the many inconsistencies
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that may show up well outside the forecast area. In general, areas highlighted in red are areas
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that “would have” been fixed if the fixed option were chosen.
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<br><br>
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<b>All (overrides other choices if not No)</b><br>
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This first option is a quick way to have all the weather elements this Procedure can check or fix,
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checked or fixed at once. If left <i>No</i>, the procedure will check or fix weather elements according
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to the options selected below.
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<br><br>
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Checking <i>Highlight only</i> will run all the available checks, and produce the highlight grids
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for those grids containing inconsistencies. The <i>Fix All</i> option fixes those grids which are
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found inconsistent: they force grid values in line with values being compared against.
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<br><br>
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<b>NDFD</b> Grid Check is the routine that checks for the existence of all grids required for the
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NDFD. It checks for all seven days, regardless of the time range chosen. It doesn’t highlight or
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“fill in” missing grids; rather, it lists the missing grids and the times for which they are
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missing When finished, “-- Missing grids listed below !! --“ appears in the status bar in the
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lower left portion of the GFE display. Just open up the message window by clicking on the up arrow
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just to its left of the status bar to see which grids are missing for which times. If all grids are
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present, a message, “-- All necessary grids found --” appears in the status bar instead.
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<br><br>
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Just to the right of the NDFD option is a place to check for public, fire or marine weather
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elements (the marine option can be removed for inland offices). For the public elements, heat
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index is checked for in the summer; wind chill in winter. NDFD requires snow amount grids 12
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months a year over the CONUS. All other public weather elements are all year round.
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<br><br>
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<b>CheckTandTd (All 7 days only)</b><br>
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The temperature checks are carried out for all 7 days, regardless of the time periods chosen.
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MinT and MaxT grids are checked against one another in chronological order. Values in the first
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MaxT grid are made to at least equal values in the previous MinT grid, i.e., the grid from the night
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before. Likewise, values in the first MinT grid are made to at most equal values in the previous
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MaxT grid, i.e., the grid from the day before. This assures all values in a given MinT grid end up
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at or below all values in both adjacent MaxT grids, and all values in a given MaxT grid end up at or
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above all values in both adjacent MinT grids.
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<br><br>
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For the highlight only option, the actual error is shown in the red area in the temporary
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Invalid[Element] grid. So, if MaxT is too low compared to the following MinT grid, negative
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values will appear showing how much too low the grid is at each point.
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<br><br>
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Values in T grids are then forced to at least equal values in corresponding MinT grids, and/or at
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most equal all values in corresponding MaxT grids. For the highlight option, values shown in red
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in the temporary grid show where T is above the corresponding MaxT or below the corresponding MinT.
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The purple area is where T is OK.
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<br><br>
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<i>Td</i><br>
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This is done automatically with the CheckTandTd option. After forcing T within MinT and MaxT, Td is
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forced to at most equal T.
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<br><br>
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For the highlight option, values shown in red in the temporary grid show where Td is above T.
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<br><br>
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<i>RH, Heat Index (For Fix Option Only)</i><br>
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Since T and Td values are potentially changed, the RH, Wind Chill and Heat Index are all
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automatically recomputed with the CheckTandTd option, the latter two only if loaded in GFE at the
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time, a quick way to do only what is “in season.”
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<br><br>
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<b>WindGust (Fix only)</b><br>
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This check forces wind gust values to be no lower than the sustained wind speed, as required.
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There is an option to limit wind gusts in relation to the sustained wind speed. This is to avoid
|
|||
|
|
wording like “5 to 10 mph with gusts to 40 mph.” It is defaulted to 12 kts, and can be changed.
|
|||
|
|
Any wind gust values that exceed the sustained wind speed by more than this value are reduced so
|
|||
|
|
that they exceed the wind gust by exactly this value. In this way, if the user chooses 10,
|
|||
|
|
10G35KT becomes 10G20KT, in theory. In actuality, it may still come out something like 10G25KT,
|
|||
|
|
on account of the analysis methods in the ZPF text formatter. Wind speeds are averaged while the
|
|||
|
|
maximum is taken for wind gusts.
|
|||
|
|
<br><br>
|
|||
|
|
<b>CheckSkyWithPoP</b><br>
|
|||
|
|
Although there is no quantitative relationship between PoP and Sky, generally there is a qualitative
|
|||
|
|
relationship that high PoPs require high Sky values, although high Sky values do not necessarily
|
|||
|
|
mean the PoPs have to be high. This option checks Sky against PoP, allowing the forecaster to
|
|||
|
|
choose from three possible Sky-PoP relationships, then control the relationship chosen, according
|
|||
|
|
to the meteorological situation at hand. These relationship options appear just to the right of
|
|||
|
|
CheckSkyWithPoP; the “For Sky and PoP” section, allowing one to control the relationship chosen,
|
|||
|
|
appears just below the CheckSkyWithPoP option.
|
|||
|
|
<br><br>
|
|||
|
|
The first two relationships are based on the premise that the Sky should be at least equal to, if
|
|||
|
|
not greater than, the PoP. In essence, if there’s a 50% chance of rain, then it should be at least
|
|||
|
|
partly cloudy, if not mostly cloudy. It certainly shouldn’t be mostly clear if there’s that good a
|
|||
|
|
chance for rain. On the other hand, if there are a lot of clouds, there may not be much
|
|||
|
|
precipitation around. This is OK; the tool leaves these areas alone.
|
|||
|
|
<br><br>
|
|||
|
|
<i>Relationship 1:</i> Sky greater than PoP by a fixed amount. For this option, one chooses “add”
|
|||
|
|
under “Sky vs PoP Relationship.” In the “For Sky and PoP” options below, one chooses the amount by
|
|||
|
|
which the Sky should be greater than the PoP; the default is 20.
|
|||
|
|
<br><br>
|
|||
|
|
For the fix option, all Sky values not exceeding the PoP by at least the amount entered will be
|
|||
|
|
increased just enough to do so. Sky values already exceeding the PoP by more than the amount
|
|||
|
|
entered are simply left alone. For the highlight option, areas that “would have” been fixed are
|
|||
|
|
simply highlighted with ones in a grid of ones (red) and zeros (purple).
|
|||
|
|
<br><br>
|
|||
|
|
<i>Relationship 2:</i> Sky greater than PoP by a factor. For this option, one chooses “multiply”
|
|||
|
|
under “Sky vs PoP Relationship:” In the “For Sky and PoP” options below, one chooses the factor by
|
|||
|
|
which the Sky should be greater than the PoP. The default of 20 should almost definitely be
|
|||
|
|
changed, usually to a much lower value, such as 1.5 or 2.
|
|||
|
|
<br><br>
|
|||
|
|
For the fix option, all Sky values not exceeding the PoP by at least the factor entered will be
|
|||
|
|
increased just enough to do so. For example, if the factor entered is two, then the Sky values
|
|||
|
|
should always be at least double what the PoP is; those values that aren’t are increased to exactly
|
|||
|
|
double the PoP. Sky values already exceeding the PoP by more than the factor entered are simply
|
|||
|
|
left alone. For the highlight option, areas that “would have” been fixed are simply highlighted
|
|||
|
|
with ones in a grid of ones (red) and zeros (purple).
|
|||
|
|
<br><br>
|
|||
|
|
<i>Relationship 3:</i> Sky is at least a certain value (or lower limit) wherever there is weather.
|
|||
|
|
For this option, one chooses “Sky limit” under “Sky vs PoP Relationship.” In the “For Sky and PoP”
|
|||
|
|
options below, one decides 1) how much Sky cover there should be to support weather, and 2) how
|
|||
|
|
much Sky cover there should be to support a 5% PoP. For the former, weather is required for PoP
|
|||
|
|
values of 15 or greater; this is hard-coded. Here, one is really entering how much Sky cover there
|
|||
|
|
should be to support a 5% PoP, and a 15% PoP, with values in between linearly interpolated.
|
|||
|
|
<br><br>
|
|||
|
|
We are only concerned here with Sky values for the onset of weather: PoP values of between 5%
|
|||
|
|
(onset of possible trace events) and 15% (onset of measurable precipitation). The idea here is that
|
|||
|
|
the Sky limit entered should be the lowest Sky value found anywhere the PoP is 15% or greater.
|
|||
|
|
Note here that higher PoP values do not affect the algorithm: if 60 is left for Sky Limit, then all
|
|||
|
|
values lower than 60 should be raised to 60 for PoPs anywhere from 15% to 100%. Sky cover for PoPs
|
|||
|
|
of 5% to 15% should vary linearly from the values entered for a 5% PoP to the value entered for a
|
|||
|
|
15% PoP. Sky values for PoP of less than 5% are left alone.
|
|||
|
|
<br><br>
|
|||
|
|
For the fix option, the Sky is raised to that value entered for PoP needed to support measurable
|
|||
|
|
precipitation wherever the PoP is 15% or greater, the definition for a forecast of measurable
|
|||
|
|
precipitation. Sky is raised to that value entered for 5% PoP where the PoP is 5%, and left alone
|
|||
|
|
regardless of its original value where the Pop is less than 5%. For PoP values between 5% and 15%,
|
|||
|
|
a slope is created to determine the new minimum Sky in this range, varying linearly from the Sky
|
|||
|
|
value entered for 5% PoP and that entered to support measurable precipitation.
|
|||
|
|
<br><br>
|
|||
|
|
For the highlight option, a grid of zeroes (purple) and ones (red) are shown, the ones indicating
|
|||
|
|
where the Sky grid is inconsistent with the PoP grid, areas that “would have” been fixed using the
|
|||
|
|
“Fix” option.
|
|||
|
|
<br><br>
|
|||
|
|
<b>SnowAmtQPFPoPWxCheck</b><br>
|
|||
|
|
Performs two, simple consistency checks on the SnowAmt grid:<br><br>
|
|||
|
|
<ol>
|
|||
|
|
<li>Where SnowAmt >= 0.5 inches, checks to ensure QPF >= 0.01 inches.</li>
|
|||
|
|
<li>Where SnowAmt >= 0.1 inches, checks to ensure Wx contains S, SW, and/or IP. The frozen
|
|||
|
|
precipitation type can be mixed with any liquid and/or freezing precipitation type. The procedure
|
|||
|
|
does not consider coverage, intensity, and/or visibility of the frozen precipitation in the Wx
|
|||
|
|
grid. There are two cases, which are subtly different:</li>
|
|||
|
|
<ul>
|
|||
|
|
<li>If the SnowAmt grid is 6-hr long and starts at 00, 06, 12, or 18 UTC, then at least
|
|||
|
|
one of the overlapping Wx grids must contain S, SW, and/or IP.</li>
|
|||
|
|
<li>All other SnowAmt grids will have to have all overlapping Wx grids contain S, SW,
|
|||
|
|
and/or IP. The more stringent check is required because if the GFE grid time constraints are
|
|||
|
|
offset from the NDFD time constraints, it is possible for the GFE to return a consistent
|
|||
|
|
result but have the NDFD believe the grids are inconsistent.</li>
|
|||
|
|
</ul>
|
|||
|
|
</ol><br>
|
|||
|
|
The procedure also performs two, simple consistency checks on the QPF grid:<br><br>
|
|||
|
|
<ol>
|
|||
|
|
<li>Where QPF > 0.0, checks to ensure at least one of the overlapping PoP grids is greater
|
|||
|
|
than zero. The PoP grids here are the “floating” PoP grids.</li>
|
|||
|
|
<li>Where QPF > 0.0, checks to ensure that the overlapping Wx grids have at least one of
|
|||
|
|
the precipitating Wx types, which includes L and ZL. The check is made against the Wx type
|
|||
|
|
only. The procedure does not consider coverage, intensity, and/or visibility of the
|
|||
|
|
precipitating Wx type. There are two cases, which are subtly different:</li>
|
|||
|
|
<ul>
|
|||
|
|
<li>If the QPF grid is 6-hr long and starts at 00, 06, 12, or 18 UTC, then at least
|
|||
|
|
one of the overlapping Wx grids must contain precipitating weather.</li>
|
|||
|
|
<li>All other QPF grids will have to have all overlapping Wx grids contain precipitating
|
|||
|
|
weather. The reasons for the more stringent test are the same as with the SnowAmt/Wx
|
|||
|
|
consistency check.</li>
|
|||
|
|
</ul>
|
|||
|
|
</ol><br>
|
|||
|
|
<b>Notes:</b><br>
|
|||
|
|
<ol>
|
|||
|
|
<li>In case it's not clear, for both the SnowAmt/Wx and QPF/Wx checks, if you have a mixture
|
|||
|
|
of SnowAmt/QPF grids where some meet the 6-hr definition and some do not, then the “any” Wx grid
|
|||
|
|
check applies for the 6-hr grids and the “all” Wx grid check applies to the others.</li>
|
|||
|
|
<li>For all checks, if the initial threshold is not met, then the grids are considered
|
|||
|
|
consistent by definition. In other words:</li>
|
|||
|
|
<ul>
|
|||
|
|
<li>If SnowAmt < 0.5 inches, then SnowAmt and QPF are always consistent.</li>
|
|||
|
|
<li>If SnowAmt < 0.1 inches, then SnowAmt and Wx are always consistent.</li>
|
|||
|
|
<li>If QPF = 0, then QPF and PoP are always consistent.</li>
|
|||
|
|
<li>If QPF = 0, then QPF and Wx are always consistent.</li>
|
|||
|
|
</ul>
|
|||
|
|
</ol>
|
|||
|
|
If the procedure finds any inconsistencies, it will highlight the inconsistent grids and create
|
|||
|
|
temporary grids which show where the inconsistencies occur. The values in all the temporary grids
|
|||
|
|
are either zero (consistent) or one (inconsistent). The procedure does not modify any grids.
|
|||
|
|
It's left up to the forecaster to determine how, if at all, to handle the inconsistencies.
|
|||
|
|
The issue of a check only versus a check/force procedure was discussed by the STSIT and the
|
|||
|
|
consensus recommendation was a check only procedure. The STSIT feels strongly that there are
|
|||
|
|
no meteorologically sound ways to force consistency of these grids.
|
|||
|
|
<br><br>
|
|||
|
|
When the procedure is run, the forecaster is presented with several choices. The first is whether
|
|||
|
|
to run checks or to “Cleanup”. By default, the procedure will run checks. The “Cleanup” option
|
|||
|
|
will undo any highlighting and remove any temporary grids. If you leave “Check” selected, then
|
|||
|
|
you can choose which of the checks you wish to run by toggling on and off the appropriate button.
|
|||
|
|
By default, all checks will be run.
|
|||
|
|
</font>
|
|||
|
|
</body>
|
|||
|
|
</html>
|