1. Brian Collins Meteorologist Southwest Airlines Brian.Collins@wnco.com
Aviation Weather Hazards in the Western U.S. and the NWS Role in Corresponding Decision Support
Southwest Aviation Weather Safety Workshop
Albuquerque, NM Oct 26, 2011
Brian Collins
Meteorologist
Southwest Airlines

2. Topics of Discussion Quick look at SWA Facts and Figures
SWA Weather Overview
Western Weather Hazards and the corresponding decision making process
NWS Product Suite – Consistency is key
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3. SWA Facts and Figures 3400+ daily flights from 72 airports
550 Boeing 737 aircraft (300’s, 500’s, 700’s)
Average flight length is 653 miles
Shortest: 133 miles (RSW-MCO)
Longest: 2,295 miles (BWI-SAN)
Southwest consumed 1.4 billion gallons of jet fuel in 2010
New aircraft expected to begin sevice next Spring (increase passenger capacity from 137 to 175)
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4. SWA Cities
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5. SWA Cities
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6. Top 10 SWA Airports Cities Daily Departures Number of Gates
Nonstop Cities Served
Established
MDW
226 29 55
1985
LAS
222 19
1982
PHX
186 24 49
BWI
177 22 46
1993
DEN
155 17 42
2006
HOU
133 32
1971
DAL
127 15
LAX
113 11 21
OAK
107 13
1989
SAN 95 18
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7. SWA Weather Big picture is a major responsibility
Significant involvement in strategic decision making process (i.e., large scale aircraft movement, weather related station decisions)
Involvement in tactical decision making as needed
Rely solely on NWS TAFs for individual flight planning decisions
Twice daily briefings to ops-related groups (Dispatch, Pilots, Maintenance, Ground Operations, Reservations, Crew Scheduling, Executive Office, Customer Service)
Significant participation in various industry workgroups
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8. Convection in the Western U.S.
Implications and decisions for SWA operations
Decisions not always clear cut, sometimes risk/reward thought process is necessary
Traditionally it would be go, go, go until forced to stop…..that has changed
Sometimes holding flights upstream can pay off more than sending them all
Connections also big part of the puzzle
Factors besides actual weather also influence decisions
What is the specific airport?
Is it a maintenance and/or crew base? Handle crew timing out?
Aircraft availability for swaps on late lines?
Potential for taxi/ramp congestion, ATC initiatives (can get planes caught)
Late operations - airport curfews, station staffing (able to support sig late ops)
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9. Convection in the Western U. S
Convection in the Western U.S. Getting flight in ahead of significant weather
Positives
Maintain schedule times
Potential to turn & go before sig weather hits
Weather could diminish prior to impacting station
Negatives
Aircraft may be in path of potential damage (hail, strong winds, lightning, dust deposits)
Cost of damaged aircraft quite high
Crew timing out possible if departures stopped for any length of time
Less control when wx impacts a station (it’s not easy to speed up a departure)
Gridlock can develop if flights come in but are not getting out
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10. Convection in the Western U. S
Convection in the Western U.S. Holding flights (in air or on ground) ahead of sig weather
Positives
Protect aircraft from possible damage
Multiple aircraft damaged by hail this year (DAL, OMA, TUS)
Dust has accounted for OTS aircraft at PHX in several events this season
Can address possible crew timeout issues upstream (position new crew)
When held upstream, better control of aircraft into station after weather moves off
Negatives
Passengers aren’t there yet!
Airborne flights have increased diversion potential with holding limitations based on fuel
Distant alternates, minimal services, unpleasant passenger experience
Cost of diversions quite high
Post-divert return to original destination not a guarantee (dependent on wx)
Lost time (also increases delays down line)
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11. Significant Dust in LBB (Oct 17th, 2011)
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12. Decision Support from the NWS
Aviation portion of AFD is a huge asset
Adds clarification, conveys forecast confidence, and presents potential “if then” secondary scenarios
Provides access to local NWS office expertise on timing and type of precip, wind variations, ceiling/vis issues
Breaking out specific airports (LAS, PHX, LAX) is VERY helpful
TAF Highlights
Amend in timely manner when necessary, even if near end of TAF cycle (Important with regard to planning for fuel load!)
Utilization of VCTS and CB in TAF are key and can be very helpful
Same notation can have different interpretation in west vs east U.S.
East - frequently means potential for T-storms with rain/showers, or timing of storms still somewhat uncertain
West - terrain factors play large role, with these terms used often in storm season
Frequently depict distant high terrain T-storms
AFD usually brings out the potential for actual terminal impacts
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13. Decision Support from the NWS
NWS products (and consistency among them) are key in being prepared to make operational decisions
Multiple products are viewed and utilized for various aspects of operational planning
TAF is first and foremost among tools, but dispatchers frequently look at other supporting products
Gridded Forecasts & Zone Forecasts
AFD
Convective Products (CCFP, SPC, LAMP, Model Output)
Special Weather Statements
Airport Weather Warnings
Advanced outlook event statements are big help (LBB, PHX)
Can sometimes be significant variation in forecast products (at terminal or within the local airspace)
Inconsistent products can be a source of confusion in flight planning (especially in terms of the fuel load)
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14. Decision Support from the NWS
Mixed Messages (Example #1)
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
656 AM EDT MON AUG
AVIATION /12Z MONDAY   AFTER 12Z TODAY…SCATTERED SHOWERS AND THUNDERSTORMS SHOULD BEGIN TO FIRE BY LATE MORNING INTO EARLY AFTERNOON WHICH MAY RESULT IN LOCALIZED LOWER CONDITIONS. MAIN HAZARDS WITH ANY TSTMS WILL BE HEAVY RAINFALL.        KBOS TERMINAL...MEDIUM CONFIDENCE IN TAF.  ITS UNCERTAIN HOW QUICKLY LOW CLOUDS BURN OFF LATER THIS MORNING AND AFTERNOON. IN  ADDITION...SCATTERED SHOWERS AND THUNDERSTORMS MAY AFFECT THE TERMINAL AT TIMES TODAY.  VFR CONDITIONS ARE EXPECTED BY TONIGHT.  
ZONE FORECAST PRODUCT FOR SOUTHERN NEW ENGLAND
715 AM EDT MON AUG  
INCLUDING THE CITIES OF...BOSTON...CHELSEA...REVERE...WINTHROP  
715 AM EDT MON AUG
TODAY: MOSTLY CLOUDY. A CHANCE OF SHOWERS WITH ISOLATED THUNDERSTORMS THIS MORNING...THEN NUMEROUS SHOWERS AND SCATTERED THUNDERSTORMS THIS AFTERNOON. AREAS OF FOG THIS MORNING. LOCALLY  HEAVY RAINFALL POSSIBLE THIS AFTERNOON. HIGHS IN THE UPPER 70S. NORTHEAST WINDS 5 TO 10 MPH. CHANCE OF RAIN 60 PERCENT.
KBOS Z 0812/ KT 4SM BR FEW008 SCT060
      FM KT P6SM SCT012 BKN070
      FM KT P6SM BKN050
FM KT P6SM SCT050
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15. Decision Support from the NWS
Mixed Messages (Example #2)
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW ORLEANS LA   1214 PM CDT TUE SEP     AVIATION   STRONG OUTFLOW BOUNDARY GENERATED FROM OVERNIGHT MESOSCALE   CONVECTIVE SYSTEM IN CENTRAL MISSISSIPPI CURRENTLY PASSING THROUGH   SE LOUISIANA AND OFF THE MISSISSIPPI COAST. MORNING SOUNDING   SHOWED HIGH INSTABILITY SUPPORTIVE OF CONDITIONALLY STRONG   THUNDERSTORMS AS TEMPERATURES EXCEED 88F. MAY NEED TO INCLUDE   BRIEF TEMPO GROUPS AT A FEW TERMINALS FOR ANTICIPATED CONVECTION   BUT WILL TRY TO SHOW DISCRETION TO MOST LIKELY LOCATIONS...LEAVING   OUT OTHERS WITH LESS THAN 30 PERCENT EXPECTATIONS.
KMSY Z 2718/ KT P6SM FEW040 SCT250
TEMPO 2719/2722 VRB20G40KT 1SM +TSRA BKN025CB
FM KT P6SM SCT015
TEMPO 2809/2813 5SM BR BKN012
NWS New Orleans/Baton Rouge, LA
Point Forecast: New Orleans International Airport LA  (29.97°N 90.25°W):
This Afternoon: Mostly sunny, with a high near 91. West wind around 10 mph.
Tonight: Partly cloudy, with a low around 74. West wind around 10 mph.
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16. Summary & Thanks Going the Extra Mile Additional Helpful Actions
Allowing us to be included in conference calls initiated for media or emergency management on significant weather events….very helpful.
Accepting our calls for brief discussions as conditions warrant…..is a huge help.
Additional Helpful Actions
Familiarity with your airports operating criteria and local minimums
Working closely with your CWSU to ensure forecast consistency and awareness of traffic flow status
Web sites have become excellent sources for keeping up with current weather events and looking ahead to upcoming events
Overall increased attention to aviation weather has been very recognizable!
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