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An Overview of the AMS Chapter/Iowa Forecast Contest (AFC). Jeremy Grams. AMS/Iowa Forecast Contest. An advanced forecast contest for ISU. Forecast different elements. Public: Max/Min Temps, POPs, QPF, QSF Aviation: Ceilings, Visibilities, and Winds.
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An Overview of the AMS Chapter/Iowa Forecast Contest (AFC) Jeremy Grams
AMS/Iowa Forecast Contest • An advanced forecast contest for ISU. • Forecast different elements. • Public: Max/Min Temps, POPs, QPF, QSF • Aviation: Ceilings, Visibilities, and Winds. • Forecast for various days (from day 1 to 7). • Square the error scoring system. • Forecast again all MOS and the NWS. • Forecast across central Iowa. • 4 days per week (Mon. - Thurs.) • Must complete 12 of the 21, 2-week & 1-week periods. • Year-end tournament in late summer.
Schedule • Sep. 12th - Sep. 22nd Des Moines Day 1 T/P/Q • Sep. 26th - Oct. 6th Ames Day 2 T/P/Q • Oct. 10th - Oct. 20th Ottumwa Day 2.5 T/P/Q • Oct. 24th - Nov. 3rd Estherville Day 7/6/5/4 T/P • Nov. 7th - Nov. 17th Marshalltown Day 1 T/P/Q/S • Nov. 28th - Dec. 8th Waterloo Day 1 W/C/V • Dec. 19th - Dec. 22nd AMW & DSM Day 2 T/P/Q/S • Jan. 9th - Jan. 19th Mason City Day 1 T/P/Q/S • Jan. 23rd - Feb. 2nd Lamoni Day 5 T/P • Feb. 6th - Feb. 16th Marshalltown Day 4/3/2/1 T/P/Q/S • Feb. 20th - Mar. 2nd Ottumwa Day 1 W/C/V
Schedule • Mar. 6th - Mar. 9th Mason City Day 1 & 2 T/P/Q/S • Mar. 20th - Mar. 30th Des Moines Day 2 T/P/Q/S • Apr. 3rd - Apr. 13th Marshalltown Day 7/6/5/4 T/P • Apr. 17th - Apr. 27th Estherville Day 1 T/P/Q • May 8th - May 11th ALO & OTM Day 1 T/P/Q • May 15th - May 25th Lamoni Day 2.5 T/P/Q • Jun. 5th - Jun. 15th Mason City Day 1 W/C/V • Jun. 19th - Jun. 29th Ames Day 1 T/P/Q • Jul. 10th - Jul. 20th Des Moines Day 4/3/2/1 T/P/Q • Jul. 24th - Aug. 3rd Waterloo Day 2 T/P/Q • Aug. 7th - Aug. 17th ***Tournament***
Forecast Interval • Forecast submitted by 2330z (6:30 pm CDT). • Temperature • Min between 01z to 14z. • Max between 13z to 01z. • Precipitation • 00z to 12z and 12z to 00z. • Wind Speed • Highest sustained from 03z to 18z. • Ceiling and Visibility • Minimum prevailing between 03z to 18z.
Forecast Elements • All elements but temperature are categorized. • POP – Cat 0 to 10 (0-100%). • QPF QSF • 0 -- 0.00" or trace 0 -- 0.0" or trace • 1 -- 0.01 to 0.09“ 1 -- 0.1 to 1.9" • 2 -- 0.10 to 0.24" 2 -- 2.0 to 3.9" • 3 -- 0.25 to 0.49" 4 -- 4.0 to 5.9" • 4 -- 0.50 to 0.99" 6 -- 6.0 to 7.9" • 5 -- 1.00 to 1.99" 8 -- >= 8.0" • 6 -- >= 2.00"
Forecast Elements • HWS LRC • 1 -- 0 to 3 kts 1 -- < 200 feet • 2 -- 4 to 7 kts 2 -- 200 to 400 feet • 3 -- 8 to 11 kts 3 -- 500 to 900 feet • 4 -- 12 to 15 kts 4 -- 1000 to 1900 feet • 5 -- 16 to 19 kts 5 -- 2000 to 3000 feet • 6 -- 20 to 23 kts 6 -- 3100 to 6500 feet • 7 -- 24 to 27 kts 7 -- 6600 to 12000 feet • 8 -- >= 28.0 kts 8 -- >= 12000 feet or no ceiling • LRV • 1 -- < 0.5 miles 5 -- 3.0 to 5.4 miles • 2 -- 0.5 to 0.9 miles 6 -- 5.5 to 6.4 miles • 3 -- 1.0 to 1.9 miles 7 -- >= 6.5 miles • 4 -- 2.0 to 2.9 miles
Verification • All sites verified at airports with NWS/FAA ASOS. • POP • Verified as 0 for no precip or trace. • Verified as 100 for 0.01” or greater. • Snowfall will be at the official NWS coop site for that city. • Anytime snow or sleet is reported by ASOS. • NWS coop sites will be used.
Verification • Highest wind speed • Highest sustained speed reported at any hourly or special observation. • Gusts are not verified. • Lowest ceiling and visibility • Any observation (hourly or special) • If variable, will use only prevailing.
Scoring • Squaring the errors for differentiation. • Divide by normalization factor. • Temperature • 1 degF = 1 errors divide by 5 = 0.2 • 5 degF = 25 errors divide by 5 = 5.0 • 15 degF = 225 errors divide by 5 = 45.0 • POP • 10% = 1 errors divide by 2.5 = 0.4 • 50% = 25 errors divide by 2.5 = 10.0 • 100% = 100 errors divide by 2.5 = 40.0
Scoring • QPF/QSF • 1 cat = 1 errors divide by 0.5 = 2.0 • 3 cat = 9 errors divide by 0.5 = 18.0 • 5 cat = 25 errors divide by 0.5 = 50.0 • HWS/LRC/LRV • 1 cat = 1 errors divide by 1 = 1.0 • 3 cat = 9 errors divide by 1 = 9.0 • 6 cat = 36 errors divide by 1 = 36.0
Normalized Scores • All scores are normalized at the end of the period. • Since not all forecasters will attempt the same cities. • Normalized score = • [(raw score -mean)*10]/S + 80. • Mean is average of all forecasts. • S is standard deviation of all forecasts. • The lower your score is, the more accurate you are relative to other forecasters.
Absences • Must forecast 6 of the 8 days in a period. • Miss a forecast • Assigned consensus MOS. • If you know you will be absent. • You can email me with the specific MOS or combo you want.
MOS • GFS • MAV – short-term • MEX – long-term • MEC – long-term ensemble • Eta • MET – short-term • NGM • FWC – short-term • CMO & MAVMET • Consensus of above models.
NWS • Their forecasts through 2340z. • Point Forecast Matrix (PFM). • For Temperature, POP, QPF, QSF, and HWS. • Terminal Aerodrome Forecast (TAF). • For HWS, LRC, and LRV.
Year-End Tournament • Head-to-head battles between forecasters. • Will play only against another forecaster. • Winners move on to play other winners, while losers play other losers. • Seeding based on regular season scores.
How to Sign Up • Will need to register with username and password. • http://www.meteor.iastate.edu/~miraje/AFC/ • Click the “Add Yourself” link on the top of the page. • http://www.weatherforecastforyou.com/AFC/add.php • Please keep your username to 8 characters and all lower-case. • Your password will be encrypted in a database, so if you forget your password send me an email.
Questions • Web Site: • http://www.meteor.iastate.edu/ams/ • Click on AMS Forecast Contest link • Email: • Jeremy Grams (jgrams@iastate.edu)