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Snow – December 15, 2008 Gina McGuire

Snow – December 15, 2008 Gina McGuire. First…Let’s just look at some Amendments from Dec. 14 th and see what we think. We will look at a few TAFs that went out on the afternoon/evening of Dec. 14 th between 15/00z and 15/06z.

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Snow – December 15, 2008 Gina McGuire

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  1. Snow – December 15, 2008Gina McGuire

  2. First…Let’s just look at some Amendments from Dec. 14th and see what we think • We will look at a few TAFs that went out on the afternoon/evening of Dec. 14th between 15/00z and 15/06z. • Observe the difference between the scheduled TAFs and any amendments that were sent out (focus on first 6 hours) • Compare the scheduled and amended TAFs to observations • Determine if the amendments were warranted and if they helped the TAF and operations • Then, we will look at the Dec. 15th event and see how we did!

  3. Reno TAFs – Let’s look at Content and why Amendments were issued? • KRNO 142321Z 1500/1524 18012G20KT P6SM VCSH SCT045 BKN070 FM150300 16008KT 4SM –SN BKN030 OVC050 TEMPO 1503/1506 2SM –SN BKN018 OVC030 FM150600 16006KT 1SM –SN BR BKN008 OVC015 TEMPO 1506/1510 1/2SM SN FG VV006 FM151200 18006KT 2SM –SN BR BKN012 OVC020 FM151900 24007KT P6SM VCSH SCT015 BKN025 TEMPO 1519/1523 4SM –SHSN BKN015 • KRNO 0052Z 1501/1524 18010KT 6SM BR SCT035 BKN060 TEMPO 1501/1503 1 1/2SM –SN BR SCT010 OVC018 FM150300 16008KT 5SM –SN BKN035 OVC050 TEMPO 1503/1506 1SM –SN OVC012 FM150600 16006KT 1SM –SN BR BKN008 OVC015 FM151200 18006KT 2SM –SN BR BKN012 OVC020 FM151900 24007KT P6SM VCSH SCT015 BKN025 • KRNO 0259Z 1503/1524 18010KT P6SM SCT035 BKN060 TEMPO 1504/1506 1 1/2SM –SN BR SCT010 OVC018 FM150600 16006KT 1SM –SN BR BKN008 OVC015 FM151200 18006KT 2SM –SN BR BKN012 OVC020 FM151900 24007KT P6SM VCSH SCT015 BKN025

  4. Reno TAFs – Why the Amendments? • KRNO 0259Z 1503/1524 18010KT P6SM SCT035 BKN060 TEMPO 1504/1506 1 1/2SM –SN BR SCT010 OVC018 FM150600 16006KT 1SM –SN BR BKN008 OVC015 FM151200 18006KT 2SM –SN BR BKN012 OVC020 FM151900 24007KT P6SM VCSH SCT015 BKN025 • KRNO 150457Z 1505/1524 18010KT P6SM SCT035 BKN060 TEMPO 1505/1506 3/4SM –SN BR VV008 FM150600 16006KT 1SM –SN BR BKN008 OVC015 FM151200 18006KT 2SM –SN BR BKN012 OVC020 FM151900 24007KT P6SM VCSH SCT015 BKN025 TEMPO 1519/1523 4SM –SHSN BKN015 • Let’s look back at the 01Z amendment… • KRNO 0052Z 1501/1524 18010KT 6SM BR SCT035 BKN060 TEMPO 1501/1503 1 1/2SM –SN BR SCT010 OVC018 FM150300 16008KT 5SM –SN BKN035 OVC050 TEMPO 1503/1506 1SM –SN OVC012 FM150600 16006KT 1SM –SN BR BKN008 OVC015 FM151200 18006KT 2SM –SN BR BKN012 OVC020 FM151900 24007KT P6SM VCSH SCT015 BKN025 • Let’s look at the observations…

  5. Observations • KRNO 142355Z 20011KT 10SM FEW045 BKN070 BKN100 OVC140 01/M08 A2971 RMK AO2 SLP073 SHSN DSNT SE-W MTN TOPS OBSCD DSNT SE-W • KRNO 150055Z 17011KT 7SM -SN SCT030 BKN040 OVC100 M01/M05 A2970 RMK AO2 SNB55 SLP075 SHSN DSNT SE-NW MTNS OBSCD DSNT S-NW • KRNO 150155Z 15004KT 10SM SCT030 BKN060 BKN080 M02/M06 A2968 RMK AO2 SNE08 SLP069 P0000 T10171056= • KRNO 150255Z 00000KT 10SM BKN030 OVC070 M02/M05 A2967 RMK AO2 SLP062 60000 T10171050 58011= • KRNO 150355Z 17006KT 10SM OVC060 M02/M05 A2965 RMK AO2 SNB15E39 SLP058 P0000 T10171050= • KRNO 150416Z 15006KT 1 3/4SM -SN BR BKN018 OVC060 M02/M04 A2965 RMK AO2 TWR VIS 2 SNB00 P0000= • KRNO 150431Z 19005KT 2SM -SN BR OVC013 M02/M03 A2965 RMK AO2 SNB00 P0000= • KRNO 150435Z 20004KT 1 1/4SM -SN BR OVC011 M02/M03 A2964 RMK AO2 TWR VIS 2 SNB00 P0000= • KRNO 150440Z 18005KT 3/4SM -SN BR VV008 M02/M03 A2964 RMK AO2 TWR VIS 2 SNB00 P0001= • KRNO 150455Z 00000KT 3/4SM -SN BR VV004 M02/M03 A2964 RMK AO2 TWR VIS 1 SNB00 SLP049 P0002 T10221033= • KRNO 150503Z 00000KT 1SM -SN BR OVC005 M03/M04 A2963 RMK AO2 SFC VIS 1 1/4 P0000= • KRNO 150509Z 00000KT 2SM -SN BR BKN007 BKN047 OVC060 M02/M04 A2963 RMK AO2 TWR VIS 3 P0000= • KRNO 150515Z 00000KT 3SM -SN BR SCT007BKN044 OVC060 M03/M04 A2963 RMK AO2 SFC VIS 4 P0000= • KRNO 150532Z 00000KT 9SM -SN BKN026 BKN041 OVC060 M02/M04 A2964 RMK AO2 P0000= • KRNO 150545Z 00000KT 2SM -SN BR FEW020 BKN024 OVC060 M02/M03 A2963 RMK AO2 SFC VIS 3 P0000= • KRNO 150552Z 00000KT 1 1/4SM -SN BR SCT018 BKN024 OVC029 M02/M03 A2963 RMK AO2 TWR VIS 2 P0000= • KRNO 150555Z00000KT 1SM -SN BR FEW010 BKN018 OVC024 M02/M03 A2963 RMK AO2 TWR VIS 1 1/2 SLP042 P0001 60003 T10221033 10006

  6. More Reno TAFs – Why the Amendments? • KRNO 150526Z 1506/1606 VRB03KT 6SM –SN BR SCT015 BKN035 BKN060 TEMPO 1506/1509 1SM –SN BR VV007 FM151200 VRB03KT 3/4SM –SN BR VV008 FM151800 24007KT P6SM VCSH SCT015 BKN035 FM160200 VRB03KT 3SM –SN BR SCT010 BKN020 OVC035 • KRNO 150914Z 1509/1606 00000KT 2SM –SN BR BKN010 OVC020 TEMPO 1509/1512 4SM –SN BR VV008 FM151800 24007KT P6SM VCSH SCT015 BKN035 FM160200 VRB03KT 3SM –SN BR SCT010 BKN020 OVC035 • KRNO 151132Z 1512/1612 15006KT 6SM –SN BR SCT012 BKN030 TEMPO 1514/1518 2SM –SHSN BR BKN010 OVC020 FM152000 20010KT P6SM VCSH SCT030 BKN050 FM160400 25006KT 3SM –SN BR BKN010 BKN020

  7. Observations • KRNO 150555Z 00000KT 1SM -SN BR FEW010 BKN018 OVC024 M02/M03 A2963 RMK AO2 TWR VIS 1 1/2 SLP042 P0001 60003 T10221033 10006 • KRNO 150603Z 00000KT 1 1/2SM -SN BR SCT008 BKN016 OVC022 M02/M03 A2962 RMK AO2 P0000= • KRNO 150633Z 00000KT 1 1/2SM -SN SCT034 BKN050 OVC065 M02/M03 A2962 RMK AO2 SFC VIS 8 P0000= • KRNO 150655Z 03003KT 1 1/2SM -SN FEW008 SCT048 OVC060 M02/M03 A2961 RMK AO2 SFC VIS 10 SLP038 P0000 T10171033= • KRNO 150709Z 04003KT 1 1/2SM -SN BR FEW018 BKN023 OVC035 M02/M03 A2961 RMK AO2 SFC VIS 2 1/2 P0000= • KRNO 150737Z 02004KT 1 1/2SM -SN BR FEW016 BKN032 OVC060 M02/M03 A2960 RMK AO2 SFC VIS 6 P0000= • KRNO 150755Z 35004KT 1 1/2SM -SN BR SCT019 BKN036 OVC065 M02/M04 A2960 RMK AO2 SFC VIS 3 SLP035 P0000 T10221039 400281061= • KRNO 150824Z 00000KT 1 1/4SM -SN BR BKN008 OVC022 M02/M03 A2960 RMK AO2 TWR VIS 1 1/2 P0001= • KRNO 150836Z 00000KT 1 1/2SM -SN BR BKN008 OVC022 M02/M03 A2959 RMK AO2 P0001= • KRNO 150844Z 35003KT 1 1/4SM -SN BR BKN008 OVC018 M02/M03 A2960 RMK AO2 TWR VIS 1 1/2 P0001= • KRNO 150850Z 00000KT 1 1/2SM -SN BR SCT008BKN016 OVC022 M02/M03 A2959 RMK AO2 P0002= • KRNO 150855Z 00000KT 1 1/2SM -SN BR SCT014BKN022 OVC065 M02/M03 A2959 RMK AO2 SFC VIS 3 SLP029 P0002 60002 T10221033 • KRNO 150952Z 00000KT 1 1/4SM -SN BR BKN008 OVC016 M02/M03 A2960 RMK AO2 TWR VIS 1 1/2 P0000= • KRNO 150955Z 01003KT 1 1/2SM -SN BR BKN012 BKN016 OVC025 M02/M03 A2960 RMK AO2 SLP031 P0000 T10221033= • KRNO 151002Z 00000KT 1 1/2SM -SN BR FEW017 OVC024 M03/M04 A2960 RMK AO2 SFC VIS 2 1/2 P0000= • KRNO 151017Z 36003KT 1 1/2SM -SN BKN035OVC060 M02/M04 A2961 RMK AO2 SFC VIS 7 P0001= • KRNO 151044Z 36003KT 1 1/2SM -SN BR FEW007 BKN033 OVC060 M02/M03 A2962 RMK AO2 SFC VIS 4 P0001= • KRNO 151055Z 09004KT 1 1/2SM -SN BR FEW007 SCT025 OVC055 M03/M04 A2962 RMK AO2 SFC VIS 5 SLP039 P0001 T10331044= • KRNO 151117Z 00000KT 10SM FEW012 SCT035 BKN055 M04/M05 A2961 RMK AO2 SNE08 P0000= • KRNO 151155Z 22005KT 6SM MIFG FEW014 SCT055 M04/M06 A2961 RMK AO2 SNE08 SLP039 P0000 60003 70006 T10441056 11017 21056

  8. On to December 15th… • Look at radar data between 15/12z and 16/06z • Discuss radar features that would be important in TAF writing • Look at TAFs and Amendments issued • Discuss good/bad elements in the TAF and see how we did!

  9. What do you observe about the radar? What jumps out at you? • Precipitation Nature • Showery? Stratiform?  Stratiform initially over the Sierra, then becomes showery over time in wrn Nevada. • Is showery precip harder/easier to forecast for a TAF as opposed to stratiform?  Usually more difficult due to variances in cig/vis/shower intensity • Any issues with spillover, or lack there of?  Spillover doesn’t seem to be an issue as showers are having no trouble making it into wrn NV. • Any areas of concern? • What might you look at to determine how intense any precipitation is? • Satellite • Upstream Metars (KTRK for KRNO at times) • Web Cams • RAWS possibly • Road conditions • CHP Website

  10. Reno TAFs • KRNO 151132Z 1512/1612 15006KT 6SM -SN BR SCT012 BKN030 TEMPO 1514/1518 2SM -SHSN BKN010 OVC020FM152000 20010KT P6SM VCSH SCT030 BKN050 FM160400 25006KT 3SM -SN BR BKN010 BKN020 • Based on TAF…Next shower band expected 14z-18z dropping conditions to 2sm/BKN010…let’s look at the radar again. • KTRK was reporting 1/4sm +SN at 14z… What do you think of 12z TAF now?  Conditions may not be low enough at KRNO depending on how heavy the showers make it into NV…looking at TRK is not always definitive. • Amendment issued at 1540z… • KRNO 151540Z 1516/1612 VRB03KT 4SM -SN BR SCT012 BKN025 TEMPO 1516/1519 1/2SM SHSNBKN008 OVC020FM152000 20010KT P6SM VCSH SCT030 BKN050 FM160400 25006KT 3SM -SN BR BKN010 BKN020 • Look reasonable so far based on all we’ve seen?  Yes. I don’t have later observations in this presentation, but the amendment did work out. • Now the 18z TAF… • KRNO 151749Z 1518/1618 VRB03KT 4SM -SN BR BKN015 OVC025 TEMPO 1518/1522 1/2SM SHSN FZFG BKN008 OVC020 FM152200 20010KT 5SM -SHSN BKN020 OVC035 FM160300 25006KT 1 1/2SM -SHSN BR BKN010 BKN020 FM161200 VRB03KT P6SM VCSH BKN025 OVC040 • Does this TAF look reasonable based on radar at 17z-18z?  Yes.

  11. Some Verification Numbers for Dec. 15th • Scheduled KRNO TAFs Only (NWS / GFS) – for ceiling 1000 feet / visibility 3 sm • POD – 0.78 / 0.23 • FAR – 0.25 / 0.60 • Amendments for KRNO Only • POD – 0.89 • FAR – 0.32 • Amendments DID improve the forecast with respect to POD…with only a slight decrease to FAR…however, what the numbers don’t show is when the amendments were issued the category (ie. IFR)…so where ALL of the amendments necessary? • Scheduled KRNO TAFs Only (NWS / GFS) – for ceiling 1000 feet / visibility 1 sm • POD – 0.42 / 0.31 • FAR – 0.82 / 0.89 • Amendments for KRNO Only • POD – 0.41 • FAR – 0.92 • Amendments did not improve the forecast (and hurt with respect to FAR) when we look at the conditions that would traditionally shut down the airport.

  12. Reno Airport Minimums • For Standard Operations • Aircraft with Special Instrument Approach: (all commercial aircraft) • Ceiling 200 feet, Visibility ½ SM • Aircraft without Special Instrument Approach: (all GA) • Ceiling 1100 feet, Visibility 4 SM • For Alternate Operations when sustained winds are N or NNW at least 5 kts • Aircraft with Special Instrument Approach: • Ceiling 700 feet, Visibility 1 ¾ SM • Aircraft without Special Instrument Approach • Ceiling > 1100 feet, Visibility > 4 SM • Remember that your TAF is a forecast service for the airport, not a nowcast. Customers look for future guidance, not a repeat of the current observation.

  13. TAF Reminders • TAF Format • Length of TAF • Use only 2 cloud categories • Try to keep under 6-8 lines in active weather • Keep detail to first 6 hours • Try to avoid TEMPOs beyond 6-9 hours • Forecast Tools • Satellite • Radar • TAF site and neighboring obs • Look out the window! • In active or rapidly changing weather, do not issue the TAF until the last possible moment (40 past the hour)…this could save you a quick amendment • Use the Aviation section in the AFD to voice uncertainty, or areas where the TAF may go wrong…no need to put every uncertainty in the TAF with TEMPO/PROB groups

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