NOUS41 KWBC 081348 PNSWSH TECHNICAL IMPLEMENTATION NOTICE 07-34 NATIONAL WEATHER SERVICE HEADQUARTERS WASHINGTON DC 947 AM EDT TUE MAY 8 2007 TO: FAMILY OF SERVICES /FOS/ SUBSCRIBERS... NOAA WEATHER WIRE SERVICE /NWWS/ SUBSCRIBERS... EMERGENCY MANAGERS WEATHER INFORMATION NETWORK /EMWIN/ SUBSCRIBERS... NOAAPORT SUBSCRIBERS.. OTHER NATIONAL WEATHER SERVICE /NWS/ CUSTOMERS AND PARTNERS... NWS EMPLOYEES FROM: PAUL HIRSCHBERG CHIEF... SCIENCE PLANS BRANCH OFFICE OF SCIENCE AND TECHNOLOGY /OST/ SUBJECT: UPGRADE OF GFS-BASED SKY COVER GUIDANCE: EFFECTIVE JUNE 5 2007 ATTENTION USERS OF THE MODEL OUTPUT STATISTICS /MOS/ GUIDANCE: EFFECTIVE JUNE 5 2007...STARTING WITH THE 1200 UNIVERSAL COORDINATED TIME /UTC/ MODEL CYCLE...THE NWS WILL REPLACE THE CURRENT GLOBAL FORECAST SYSTEM /GFS/-BASED MOS TOTAL SKY COVER GUIDANCE WITH NEW OPAQUE SKY COVER GUIDANCE. THE MOS SKY COVER GUIDANCE PREDICTS AN ESTIMATE OF THE TOTAL PERCENTAGE OF THE SKY COVERED BY CLOUDS IN TERMS OF THE FIVE CATEGORIES REPORTED IN THE METAR OBSERVATIONS /CLEAR... FEW... SCATTERED... BROKEN...OR OVERCAST/. THE CURRENT MOS TOTAL SKY COVER GUIDANCE DOES NOT DISTINGUISH BETWEEN OPAQUE AND TRANSLUCENT CLOUD COVER. THE NEW SKY COVER GUIDANCE PRODUCES AN ESTIMATE OF ONLY CLOUDS JUDGED TO BE OPAQUE. THE ANTICIPATED EFFECT OF THIS CHANGE WILL BE TO DECREASE THE NUMBER OF BROKEN OR OVERCAST FORECASTS AND TO INCREASE THE NUMBER OF CLEAR OR FEW FORECASTS WHEN ONLY CIRRUS CLOUDS ARE EXPECTED. THIS CHANGE WILL MAKE THE MOS GUIDANCE CONSISTENT WITH THE NWS REQUIREMENT FOR OPAQUE SKY COVER INFORMATION. THE COMMUNICATION IDENTIFIERS FOR THE TEXT AND BUFR PRODUCTS CONTAINING THIS GUIDANCE ARE SHOWN IN TABLE 1 BELOW. THE GUIDANCE WILL BE AVAILABLE FOR ROUGHLY 1750 STATIONS EVERY 3 HOURS OUT TO 84 HOURS IN ADVANCE FROM THE 0600 AND 1800 UTC MODEL RUNS AND OUT TO 192 HOURS IN ADVANCE FROM THE 0000 AND 1200 UTC MODEL RUNS. TABLE 1. COMMUNICATION IDENTIFIERS FOR THE GFS-BASED MOS PUBLIC WEATHER TEXT AND BUFR PRODUCTS TEXT WMO HEADINGS AWIPS ID FOPA20 KWNO MAVPA0 FOUS21 KWNO MAVNE1 FOUS22 KWNO MAVSE1 FOUS23 KWNO MAVNC1 FOUS24 KWNO MAVSC1 FOUS25 KWNO MAVRM1 FOUS26 KWNO MAVWC0 FOAK37 KWNO MAVAJK FOAK38 KWNO MAVAFC FOAK39 KWNO MAVAFG BUFR WMO HEADINGS BUFR WMO HEADINGS /SHORT RANGE GFS/ /EXTENDED RANGE GFS/ JSML30 KWNO JSMT30 KWNO JSML31 KWNO JSMT31 KWNO JSML32 KWNO JSMT32 KWNO JSML33 KWNO JSMT33 KWNO JSML34 KWNO JSMT34 KWNO JSML35 KWNO JSMT35 KWNO JSML36 KWNO JSMT36 KWNO JSML37 KWNO JSMT37 KWNO FOR QUESTIONS ABOUT THESE PRODUCTS OR THE MOS GUIDANCE... PLEASE CONTACT: KATHRYN GILBERT MDL/SILVER SPRING MARYLAND PHONE: 301-713-0023 EXT. 130 E-MAIL: KATHRYN.GILBERT@NOAA.GOV LINKS TO THE MOS PRODUCTS...ALONG WITH DESCRIPTIONS...CAN BE FOUND AT /USE LOWER CASE LETTERS/: HTTP://WWW.NWS.NOAA.GOV/MDL/SYNOP THIS AND OTHER NWS TECHNICAL IMPLEMENTATION NOTICES ARE AVAILABLE ON THE INTERNET AT THE /USE LOWER CASE LETTERS/: HTTP://WWW.NWS.NOAA.GOV/OM/NOTIF.HTM $$ NNNN