Selected Cities Summary, Travelers Forecast, and the National Digital Forecast Database

Selected Cities Summary, Travelers Forecast, and the National Digital Forecast Database Matt Peroutka Meteorological Development Lab May 2005

Overview • Background • Current Products and Process • Ideas to Improve the Products and Process • Character of the Day (One-word Daytime Forecasts; CoD)

Background • MDL was asked to develop techniques that generate two tabular products from NDFD. • Selected Cities Summary (SCS) • Travelers Forecast (TVL) • SCS and TVL are currently generated by NCEP using WFO input.

Current Products and Process

Sample Selected Cities Forecast SELECTED CITIES WEATHER SUMMARY AND FORECASTS...PART 1 OF 4 NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD 736 AM EST TUE NOV 09 2004 TEMPERATURES INDICATE DAYTIME HIGH...NIGHTTIME LOW B INDICATES TEMPERATURES BELOW ZERO PRECIPITATION FOR 24 HOURS ENDING AT 7 AM EST FORECAST FORECAST MON...NOV 08 TUE....NOV 09 WED....NOV 10 CITY HI/LO PCPN WEA HI/LO WEA HI/LO ABILENE TX 76 52 MOCLDY 67/55 CLOUDY 70/43 AKRON CANTON 43 28 PTCLDY 41/27 PTCLDY 54/40 ALBANY NY 45 23 PTCLDY 39/16 PTCLDY 42/32 ALBUQUERQUE 72 53 MOCLDY 62/40 PTCLDY 59/38 ALLENTOWN 49 28 PTCLDY 40/20 SUNNY 43/30 AMARILLO 66 44 MOCLDY 67/45 PTCLDY 60/31 ANCHORAGE 32 25 .05 WINDY 33/30 RAIN 43/35 ASHEVILLE 68 38 SUNNY 55/30 SUNNY 52/33 ATLANTA 69 47 SUNNY 62/38 PTCLDY 61/43 ATLANTIC CITY 52 26 SUNNY 47/27 SUNNY 49/35 AUSTIN 80 51 MOCLDY 74/57 MOCLDY 74/54 BALTIMORE 50 31 SUNNY 48/29 SUNNY 49/29

Sample Travelers Forecast TRAVELERS FORECAST TABLE...PART 1 OF 3 NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD 535 AM EST TUE NOV 09 2004 TEMPERATURES INDICATE DAYTIME HIGH...NIGHTTIME LOW B INDICATES TEMPERATURES BELOW ZERO FORECAST FORECAST TUE....NOV 09 WED....NOV 10 CITY WEA HI/LO WEA HI/LO ALBANY NY PTCLDY 39/16 PTCLDY 42/32 ANCHORAGE WINDY 33/30 RAIN 43/35 ATLANTA SUNNY 62/38 PTCLDY 61/43 BILLINGS PTCLDY 65/33 RNSNOW 40/19 BOISE FOG 42/36 MOCLDY 48/38 BOSTON FLRRYS 39/27 PTCLDY 43/35 CHICAGO SUNNY 54/42 PTCLDY 61/42 COLUMBUS OH SUNNY 47/31 PTCLDY 56/41 DALLAS FT WORTH PTCLDY 72/55 MOCLDY 73/57 DENVER MISG MM/MM MISG MM/MM DETROIT PTCLDY 45/32 PTCLDY 58/42 HONOLULU PTCLDY 85/72 SUNNY 86/73

Sample Coded Cities Forecast Max/Min Temperatures CoD letters 2-digit Forecaster ID Site ID PoPs ABI BB 080/044 074/046 067 14000 EEEEE 047/066 052/068 045/057 038/056 0-12111111 SJT BB 080/045 075/047 069 14000 EEEEE 049/067 053/070 045/059 039/057 0-12112111 JCT BB 080/044 077/045 071 14000 EEEEE 051/069 052/072 047/062 041/059 0-12112211

Comments on Current Products • Very “old-school.” I. e., capital letters, ellipses, columnar data. • Seems to be time to reconsider the format and content of these products. • Observation and forecast data combined. • Column widths limit forecast to 2 days.

Current Process for Generating SCS and TVL WFO Manual Local Digital Forecast Database NCEP CCF Product Generation Observations WFO Manual Product Generation Local Digital Forecast Database Manual CCF Product Generation SCS TVL WFO Manual Local Digital Forecast Database CCF Product Generation CCF = Coded Cities Forecast SCS = Selected Cities Forecast TVL = Travelers Forecast

Comments on Current Process • Forecasters responsible for timely generation of CCFs. • CoD is set at WFOs. • CCF formatter chooses a value, based on grids. • CCF algorithms vary from WFO to WFO. • Forecaster can edit final product. • Manual interventions at NCEP are problematic.

Ideas to Improve the Products and the Process • Introduce two new products • XML City Observations • XML City Forecasts • Pursue “retirement” of CCF, TVL, and SCS products. • CCF, TVL, and SCS could all be produced centrally from XML during transition.

XML City Observations • Produced twice daily by NCEP. • Includes same observational data as SCS. • MaxT/MinT/Pcpn for cities • National High/Low • Encoded in XML. • Some manual input required at NCEP.

XML City Forecasts • Produced hourly by NDFD Central Server. • WFO-resolution data obtained from IFPS Service Backup data feed. • MaxT/MinT/CoD for cities for all days in NDFD. • Encoded in XML.

Proposed Process for Generating XML City Products from NDFD WFO NDFD CSS NCEP Local Digital Forecast Database NDFD Observations Mosaic Grids Manual Product Generation WFO Product Generation Local Digital Forecast Database XML CityForecasts XML City Observations WFO Local Digital Forecast Database

What’s an XML? • Extensible Markup Language (XML) is a standard for data exchange that is popular in WWW applications. • Provides a flexible framework for encoding data. • Can be read by human eyes, but generally is not used that way. • Implemented successfully for NDFD WWW services. • Very well supported by public-domain software.

XML Sample <dwml xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi=“http://www.w3.org/2001/XMLSchema-instance”> <head> <product concise-name="time-series"> <creation-date>2004-02-13T21:29:11Z</creation-date> </product> <source> <production-center>MDL</production-center> </source> </head> <data> <parameters> <temperature units="Fahrenheit"> <value>45</value> <value>31</value> <value>29</value> <value>37</value> <value>41</value> <value>41</value> <value xsi:nil="true" /> </temperature> </parameters> </data> </dwml>

Character of the Day • Current NWSI 10-503 provides little guidance; maximizes forecaster judgment. • Producing summary forecasts from NDFD requires a shift away from WFO control.

Character of the Day Issues • Time: Daytime definition • Code set: 26 letters vs. 250 icons • Weather element precedence: • Threshold for wet/dry. • Threshold for windy. • Very hot/cold.

Summary • SCS, TVL, and CCF products deliver useful data in an outdated format. • XML offers a promising alternative. • More data • More flexible format • More streamlined process • Centralized production of new products and legacy products is do-able. • Encoding character of the day raises issues.

Selected Cities Summary, Travelers Forecast, and the National Digital Forecast Database