1000 km 1.25 h 1400 km / 1.75 h G-IV Pre-CalWater AR Experiment Mission Scientist Summary Marty Ralph (Scripps Inst. Oceanography); Friday 14 February 2014 IOP-6 Completed 14 FebIOP-7 Planned for 15 Feb TDR-Eval Module: 4.2 h, 4 sondes TDR + 2 AR boxes; 7 h, 14 sondes Saturday 12 FebFriday 14 Feb

WaypointLatLon (box 1 NW) (box 1 NE) (box 1 SE) (box 1 SW) (box 2 NE) (box 2 SE) (box 2 SW) (box 2 NW)32133 Drops in boxes 1 and 2 should be 50 nm apart. Legs are focused on TDR. NOTAM PtLatLon NW44126 NE43124 E central36123 SE27132 SW31136 Chief Scientist: Marty Ralph Drops every 50 nm on boxes 1 and 2, plus 2 drops TBD (total 14 drops) Waypoint not part of an AR Box Waypoint is part of an AR Box IOP-7 TDR + AR boxes: TO 930 AM 15 Feb; 14 drops

Daily Planning Summary Update: 14 Feb (Marty Ralph) Take Off date BaseChief Scientist AR characteristicsLikelihood of IOP Type of missionNotes Wed 5 FebTAFBN/ADown Day for G-IV crew Thur 6 FebTAFBN/ADown Day for G-IV crew Fri 7 FebTAFBFMRWell-defined AR with IWV > 3 cm and IVT > 600 units Done, 6 h, 23 drops 3 box module with IVT cross- section; used 23 sondes 3 boxes, each one about 1 hour to execute; Janet Intrieri onboard with FMR; Sat 8 FebTAFBFMRWell-defined AR with IWV > 3.5 cm and IVT > 700 units Done, 8 h, 29 drops Mesoscale frontal wave Used 29 sondes Mesoscale frontal wave; Dave Reynolds and Jay Jasperse onboard with FMR Sun 9 FebTAFBRSModerate AR makes landfall on central CA coast cancelledDown day for G-IV crewNear-shore track planned with military warning areas; Precip predicted to be onshore early; G-IV repair needed in Vegas Mon 10 FebTAFBN/AlowLikely down dayG-IV in Vegas under repair; return TAFB TBD – hopeful late today Tues 11 FebTAFBRSStrong AR Offshore OR IVT max >1600 units in GFS Done, 6 h, 36 drops (+2 AOC) 3 AR boxes Plus 25 nm spacing IVT cross section 1000 km long Box 2 is 50 nm larger north-south than IOP-1 due to uncertainty in AR axis position; did 25 nm dropsonde spacing on west side of boxes and between boxes for cross-section Wed 12 FebTAFBRSAR Landfall NorCalDone, 4.2 h; 15 drop IVT cross-section and TDR eval; FL380 and FL170-FL200, coastal Allen White onboard as Met support and familiarization; icing at FL , climbed to FL200 Thur 13 FebTAFBAWModerate AR off ORDone, 6 h 23 drops Long IVT x-section 3 AR boxes Major AR with occlusion Fri- 14 FebTAFBAWAR making landfall NorCalDone, 4 h, 4 drops TDR eval at 3 levelsCompleted new type of G-IV flight profile, including a lengthy leg at FL050 through clouds and some precipitation Sat 15 FebTAFBFMRAR offshore and landfallhighTDR only nearshore precip plus offshore 2 AR boxes Mon 17 FebTAFB to HNL Ferry; no targets en routehigh Tue 18 FebHNLRSKona Low + tropical tapmedium Wed 19 FebHNLnonePossible weak ARmedium

Forecast Summary (1/4) – Jay Cordeira Day-1 (Fri): Stalled AR located along NorCal Coast with forecast on track from yesterday Day-2 (Sat): Gulf of AK cyclone cold frontal AR bring AR conditions to NorCal/OR with south-southwest IVT vector Days-3-5 (Sun/Tue): “Extratropical AR” makes landfall PacNW and impacts as far south as NorCal Days-3-7 (Sun-Thu): complicated poleward water vapor transport (not really an AR) located out near HNL G-IV Pre-Calwater AR Experiment Friday 14 February 2014

Forecast Summary (2/4) Days-8-9 (Fri-Sat): Possible AR located in between HNL, ANC, TAFB which may move east toward within range of TAFB by day-9 Days 10-15: Possible AR activity across North Pacific. Models have not been too optimistic lately, but today’s forecast suggests some AR activity between HNL, ANC, TAFB G-IV Pre-Calwater AR Experiment Friday 14 February 2014

Executive Summary (3/4) G-IV Pre-Calwater AR Experiment Integrated Atmospheric Water Vapor Transport (IVT) and Direction from GFS Model: These possible ARs contain low IWV values and develop in extratropics

Overview through IOP-6 6 IOPs flown in 8 days – 3 AR box flights, 1 frontal wave flight and 2 TDR coastal flights – 9 AR divergence boxes and 5 IVT cross-sections (1 coastal) 35 h flown 130 drops used Start of experiment marked by very active period of moderate to strong Atmospheric Rivers hitting northern California, Oregon and Washington. Many locations with 3-day precipitation totals over 8 inches, with some over 12 inches. California’s 8-station Index went from 16% of normal to date to 40% of normal to date over 3-4 days (6-10 Feb) due to precipitation from landfalling ARs. Flooding in SW Oregon by 15 Feb as second series of landfalling ARs hit that region. New types of G-IV flight patterns focused on ARs were developed and tested. First low-altitude G-IV flight leg conducted at FL050 conducted about 100 nm from coast. New AR-focused forecast products developed to help guide flights and mission planning.

IOPs Completed

Forecast Summary (4/4) G-IV Pre-Calwater AR Experiment Friday 14 February 2014 WPC 7-day Precipitation Forecast ending 12Z Friday 21 Feb 2014

Synopsis of IOPs 1 and 2 3 AR boxes flown Friday 7 Feb – 6 h; 23/23 sondes – Modules captured desired conditions including AR core – Marty Ralph (CS), Janet Intrieri (Met), Ryan Spackman (Ops Center) Frontal wave flown Saturday 8 Feb – 8 h; 29/29 sondes – 3 transects with two points repeated – Moderate strength AR in well-defined frontal wave – Marty Ralph (CS), Dave Reynolds (Met), Jay Jasperse (Observer) Cancelled planned IVT mission for Sunday 9 Feb – Precip predicted to have ended offshore too early – Flight planning dealt well with military warning areas and ATC constraints – G-IV engine performance sensor repair needed; flew to Gulfstream in Vegas

03Z/8 00Z/8 21Z/7 18Z/ km 1.25 h 1000 km 1.25 h 1400 km / 1.75 h G-IV Pre-CalWater AR Experiment Mission Scientist Summary Marty Ralph (Scripps Inst. Oceanography); Sunday 9 February Z/9 00Z/9 21Z/8 18Z/8 03Z/10 00Z/10 21Z/9 18Z/9 AR axis is shown at different times (hh/date) Analyses courtesy of Jason Cordeira IOP-1 Completed 10 AM – 4 PM PTPossible IOP Take off Sun 9 Feb TAFBTakeoff 11 AM PT Sat 8 Feb TAFB DONE; 6 H MISSION, 23 DROPSDONE; 8 H MISSION; 29 DROPScancelled – due to too little precip offshore - And G-IV repair needed (Vegas)

TransectswaypointLatLon Final8 h 1 N S S b N b N b S b Trans ect Number Drops nm spacing Total29/29 IOP-2; Completed 11 AM – 7 PM PT Saturday 8 Feb; 29 drops Onboard: - Marty Ralph (Chief Scientist) - Dave Reynolds (Meteorologist) - Jay Jasperse (SCWA) Ops Center: - Ryan Spackman Transect 3 Transect 1 Transect 2

Box 1 Box 2 Box 3 AR boxLatLon 1 NE SE SW NW SW NW N center S center SE NE SW NW NE SE NOTAM PtLatLon NW41139 NE43133 SW28135 SE nm X 100 nm box 100 nm X 100 nm box IOP-1; Completed 10 AM – 4 PM Friday 7 Feb; 23 drops Onboard: - Marty Ralph (Chief Scientist) - Janet Intrieri (Meteorologist) Ops Center: - Ryan Spackman

1000 km 1.25 h 1000 km 1.25 h 1400 km / 1.75 h G-IV Pre-CalWater AR Experiment Mission Scientist Summary Marty Ralph (Scripps Inst. Oceanography); Friday 14 February 2014 IOP-3 Completed 11 FebIOP-5 Completed 13 FebIOP-4 Completed 12Feb 3 AR Box Module: 6.1 h, 36 sondes IVT-TDR Module: 4.2 h, 14 sondes IVT x-section; 6 h, 23 sondes Tuesday 11 FebThursday 13 Feb Analyses courtesy of Jason Cordeira Wednesday 12 Feb Thursday 13 Feb Tuesday 11 Feb

Overview of IOP-3: Ryan Spackman- Chief Scientist onboard 1720 – 2325 UTC, 11 Feb 2014 (6.1 h block) Strong AR west of OR Over 1600 units IVT Off the scale for the new ARDT-IVT GFS forecast initialized at 12 Z increased the max IVT by 200 units compared to 06 Z run Due to extreme nature of the event, the dropsonde spacing was decreased along the western sides of each box to 25 nm (46 km) to allow quantification of IVT in a cross-section of an extreme AR. This added about 9 sondes to the flight. Used 38 sondes, incl 2 special “slow descent sonde” for AOC testing. LLJ reached at least 87 kts km long cross-section from SW corner to NW corner of overall flight pattern with 25 nm (46 km) sonde spacing from UTC Cross-section with hi-res (25 nm; 46 km spacing)

NOTAM PtLatLon NW45140 NE49132 SW32133 SE nm X 100 nm box 100 nm X 100 nm box IOP-3: 920 AM – 330 PM Tuesday 11 Feb; 37 drops Onboard: - Ryan Spackman (Chief Scientist) -TBD (Meteorologist) -TBD (Observer) Ops Center: - Marty Ralph AR boxLatLon 1 NE SE SW NW SW NW N center S center SE NE SW NW NE SE nm X 150 nm box Box 1 Box 2 Box 3 Dropsonde spacing: 50 nm, except for 25 nm along western edges of the pattern to produce hi-res cross- section of an extreme AR.

NOTAM PtLatLon NW46127 NE46125 E Center42125 SE38126 W Center42127 SW36125 IVT trackFlight levelLatLon Pt Pt Pt 3Descend 410 to YYY* Pt 4 = Pt 2YYY Pt 5Ascend YYY to Pt 6 = Pt *Flight level YYY is determined from dropsondes between pts 1-2. FL YYY is set to be such that T < -12 C. along entire legs 3-4 and 4-5. Pts 1, 6 Pt 5 Pts 2, 4 Pt 3 IOP-4 IVT: TO 920 AM Wednesday 12 Feb; 4.2 h, 15 drops Chief Scientist: Ryan Spackman Meteorologist: Allen White Observer: Capt. Rebecca Stone (NPS) Dropsonde spacing: 60 nm to 39 N, then 30 nm Avoid ft on return where T= +2 C to -12 C

NOTAM PtLatLon NW48141 NE51137 SE31124 SW28128 IVT trackFlight levelLatLon Pt Pt Drops every 1 deg Latitiude from N Drops every 40 nm along track from N Drops every 1 deg Latitude from N IOP-5 IVT far-offshore: TO 920 AM Thursday 13 Feb; 6 h, 23 drops Chief Scientist: Allen White Meteorologist: None Observer: Capt. None Drops every 1 deg Latitude from N Drops every 40 nm along track from N Drops every 1 deg Latitude from N 2100 UTC 13 Feb

NOTAM PtLatLon NW NE SE SW TDR TrackFlight LevelLatLon Pt Pt Pt 2060* Pt 1060* Pt 1170* Pt 2170* *Flight level on mid and low legs determined from dropsondes from high leg. Decision on flight level for lower leg is decided based on Drops 3 and 4 probably during descent at Pt 2 Pt 1 Pt 2 IOP-6 Stacked TDR Flight incl FL050: TO 1038 AM, Fri 14 Feb; 4 h, 4 drops Chief Scientist: Allen White Routing: Pt 1 to 2 at FL380 (or higher) Pt 2 to 1 at FL060 (or below icing layer) Pt 1 to 2 at FL170 (or above icing layer) Icing Layer: +2 to -12C Dropsondes only on high leg at 38, 40, 41.5, 43N TAFB