1 / 34

Weather briefing – Thursday 11 June 2009

Weather briefing – Thursday 11 June 2009. NCSU – team members… Note: Data from many of our usual forecast tools (e.g., Bufkit , SREF , high-resolution simulated radar , SPC mesoanalysis page , etc.) were not available in this retrospective mode… would show other/additional plots.

coby
Download Presentation

Weather briefing – Thursday 11 June 2009

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Weather briefing – Thursday 11 June 2009 NCSU – team members… Note: Data from many of our usual forecast tools (e.g., Bufkit, SREF, high-resolution simulated radar, SPC mesoanalysis page, etc.) were not available in this retrospective mode… would show other/additional plots

  2. 5 Ops Objectives

  3. Decisions/Things to Keep in Mind(as a forecaster) • Mission has to decide where to fly and what category of objective they’re fulfilling • The ER-2 needs 24 hours’ notice to fly • The ER-2 crew has strict rest policies • 12 hours after missions • 14 if mission is 8 hours • No more than 3 days without a down day • Calls need to be made about current missions with past and future missions in mind (for the above reasons) • The Citation should stay out of >35 dBZ • ER-2 takeoff no go if: • 25 knots maximum steady or 35 gusts regardless of dir. • 15 knot maximum crosswind • 1/4 mile minimum visibility • Lightning within 5 NM

  4. Overview • Day -1 (W 10th): Stationary front to north, zonal flow aloft. Humid & unstable with moderate shear. Organized convective storms in afternoon, some severe • Day 0 (Th 11th): Instability and shear appear to have increased somewhat this morning, ingredients in place for organized convection. MCV to W this morning • Day 1 (F 12th): Weak front drops southward during the day, possibly enhanced, organized convection over area • Day 2 (Sa 13th) and beyond: Weak front to south of area, & weaker shear: Weaker, less organized convection. Potential for offshore convection with stalled front.

  5. Day -1 surface analysis: 15 Z 10 June 2009

  6. Day -1 (10 June) • MCS move east, passed to south of study area, dissipated over GA • New convection developed ahead of MCV, some severe (hail, wind) with these cells

  7. Day -1 (10 June, 12-21 UTC)

  8. NAM 500-mb Z analysis: 00 Z 11 June 2009

  9. Nashville sounding, 00 Z 11 June 2009

  10. Analysis, Day 0 (11 June) • Shear and instability have increased this morning (e.g,. ~2400 J/kg BNA at 12Z); MCV to west • One MCS to our north this morning as well, in addition to MCV to west • Diurnal heating possible this morning, further increasing severe threat • Timing: MCS/MCV over TN, moving east. Storms in area by 18 Z? Severe threat increased

  11. GOES-13 IR, 1215 Z 11 June

  12. GOES-13 VIS, 1330 Z 11 June

  13. NAM 500-mb Z,  analysis: 12 Z 11 June 2009

  14. HPC surface analysis: 12 Z 11 June 2009

  15. NAM SLP, theta-e1000, 500Z valid: 12 Z 11 June

  16. Nashville sounding, 12 Z 11 June 2009

  17. SPC Day 1 outlook, valid 13Z 11th – 12Z 12th Primary: Hail, wind

  18. SE Radar Mosaic, 0-14 UTC 11 June

  19. SE Radar Mosaic, 14 UTC 11 June

  20. SE Radar Mosaic, with NLDN, 14 UTC 11 June

  21. Day 0 Forecast (11 June) • Organized convection, MCV to west will approach study area today; MCV in NAM initial condition • New convection could fire ahead of MCV currently over western TN (similar to yesterday) • Timing: Convective storms likely to develop between 17-20Z across study region (from west) • Aircraft threats: Lightning, hail @Robins afternoon, Convection (winds, hail, lightning) KAVL after 17Z

  22. NAM 12-h CAPE, CIN valid 12 Z 11 June

  23. NAM 18-h fcst, 6-h QPF, valid 18 Z 11 June

  24. NAM 18-h fcst sounding, valid 18 Z 11 JuneKAVL WBZ: ~9200 ft Freezing level ~11,000 Sfc-6 km shear ~ 30 kt

  25. Day 1 Forecast (Fri 12 June) • Weak cold front approaches, opportunity for organized convection ahead of front • Timing of weak front difficult to establish; merges with lee trough late in day (by 00Z Sat) • Now appears that passage will be around mid-day • Only weak drying, stabilization behind front, more so in wake of any organized convection that forms • As front stalls along coast, offshore convection potential increases early morning Sat and Sun (Day 2,3)

  26. F36 NAM SLP, theta-e, 12Z 12 June

  27. F48 NAM SLP, theta-e, 00Z 13 June

  28. Days 2-3 (Sat, Sun) • Following weak cold front passage day 1, focus for convection shifts southward, and to offshore waters • Shear, instability will weaken, but sufficient instability to support diurnal orographic showers • Frontal boundary advances northward again towards study area, potential for more showers Days 2, 3 (Sat, Sun) • GFS shows MCV-type feature bringing strong storms to area Sun, but skeptical given convective origin of forcing in model forecast

  29. 60-h NAM SLP, theta-e, 500 Z 12 Z 13 June

  30. Days 4+ • NW flow storms possible, shortwave passes north of area Saturday (model variability) • With ridge axis to west (aloft), NW flow regime becomes established • Longer term: Ensemble indicates very strong ridge developing over central US, study area in NW flow but dry with synoptic subsidence

  31. 60-h GFS 500-mb Z, SLP valid 12Z Sat 13 June

  32. 84-h GFS 500-mb Z, SLP valid 12Z Sun 14 June Spurious system?

  33. 120-h GFS 500 Z, SLP valid 00Z Tue 16 June

More Related