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NWS Aviation Weather Meeting

Rick CurtisMyranda MuehlmanSouthwest Airlines

April 15, 2010

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“Why is my flight late?”

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Something magical seems to happen to us when we get to the airport

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We tend to get inside “the bubble” and we

sometimes forget about the “outside world” !

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However, nothing will stand in our way as we try to get to our business meeting,

or that well deserved vacation!

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“Just keep focusing on the goal”

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SWA Facts and Figures• 3200+ daily flights from 68 airports • 545 Boeing 737 aircraft (300’s, 500’s, 700’s)• Average flight length is 639 miles

– Shortest: 133 miles (RSW-MCO)– Longest: 2,363 miles (PVD-LAS)

• Southwest consumed 1.4 billion gallons of jet fuel in 2009.

• Southwest offers the most domestic flights of any airline

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Top 10 SWA Airports

As of 3/23/10

CitiesDaily Departures Number of

GatesNonstop Cities

Served Established

LAS 220 19 56 1982

MDW 219 29 50 1985

PHX 178 24 44 1982

BWI 171 20 41 1993

HOU 133 17 29 1971

DAL 132 15 15 1971

DEN 120 12 34 2006

LAX 113 11 18 1982

OAK 111 13 20 1989

MCO 104 12 32 1996

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Snow Events

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Snow EventsObvious - General

• Do we have airport weather minimums for takeoff?

• Do we have airport weather minimums for landing?

• Do we need an alternate?• ceiling < or equal to 2000’ • visibility < or equal to 3 miles)

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Snow EventsObvious - General

• Do we have airport weather minimums for takeoff?

• Do we have airport weather minimums for landing?

• Do we need an alternate?• ceiling < or equal to 2000’ • visibility < or equal to 3 miles)

Therefore, we should be good to go…right?

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Snow EventsNot So Obvious - General

• What limitations exist with the airport navigation equipment?

• What limitations are there with Air Traffic Control?

• What limitations are there with the aircraft?• What limitations are there with the Flight Crew?

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Snow EventsNot So Obvious - General

• De-icing capacity of the airport.• Where does de-icing take place?• What are the ramp conditions (breaking action)?• TSA Staffing?

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Snow EventsNot So Obvious - Airline

• Can the airline staff make it to work?• Can Customers make it to the airport?• Will there be a flight crew (Pilots and Flight

Attendants) if previous flights were diverted or cancelled?

• Will there be an airplane for the flight if previous flights were diverted or cancelled?

• Do we have enough de-icing fluid on hand?

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This just in…

...For these reasons the FAA is now requiring the use of the FAA Snow Intensity Table to determine appropriate holdover times in snowfall conditions (Table 1B, page 8 of the attached document) for all Types of anti-icing fluid (Type I, II, III, and IV). Because the FAA Snow Intensity Table, like the FMH-1 Table, uses visibility to determine snowfall intensities, if the visibility is being reduced by snow along with other forms of obscuration such as fog, haze, smoke, and etc. the FAA Snow Intensity Table need not be used to estimate the snow fall intensity for holdover time determination. Use of the FAA Snow Intensity Table under these conditions may needlessly overestimate the actual snowfall intensity and therefore the snowfall intensity being reported by the weather observer or ASOS, the FMH-1 Table may be used.

Source: Official FAA Holdover Time Tables and Allowance Times Winter 2009 - 2010

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Snowfall Intensity as a Function of Visibility

Time of Day

Temp. Visibility (Statute Mile)

DegreesCelsius

Degrees Fahrenheit

2 1/2 2 1 1/2 1 3/4 1/2 1/4

Day

colder/equal-1

colder/equal 30VeryLight

Very Light Light Light Moderate Moderate Heavy

Snowfall Intensity

warmer than-1

warmer than 30 VeryLight Light Light Moderate Moderate Heavy Heavy

Night

colder/equal-1

colder/equal 30 VeryLight Light Moderate Moderate Heavy Heavy Heavy

warmer than-1

warmer than 30 VeryLight Light Moderate Heavy Heavy Heavy Heavy

NOTE 1: This table is for estimating snowfall intensity. It is based upon the technical report, “The Estimation of Snowfall Rate Using Visibility,” Rasmussen, et al., Journal of Applied Meteorology, October 1999 and additional in situ data.NOTE 2: This table is to be used with Type I, II, III, and IV fluid guidelines.

HEAVY = Caution—No Holdover Time Guidelines Exist

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Ice Pellet Allowance Times Winter 2009-2010 (Type IV Fluid)

OAT -5°C or Above OAT Less Than -5°C

Light Ice Pellets 50 minutes 30 minutes

Moderate Ice Pellets 25 minutes 10 minutes

Light Ice Pellets mixed with Light or Moderate Snow

25 minutes Not Authorized Below -5°C OAT for moderate snow. 15 minute allowance for light snow. No takeoffs allowed for light snow combination when temp -10°C OAT or less.

Light Ice Pellets mixed with Light or Moderate Freezing Drizzle or Light Freezing Rain(Not Authorized below -10°C OAT)

25 minutes 10 minutesNot Authorized Below -10°C OAT

Light Ice Pellets mixed with Light Rain (OAT 0°C or Above)

25 minutes Not Authorized Below -5°C OAT

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Meteorological Data Collection and Reporting System (MDCRS)

• Seven Airline Participants (AA, Delta, FedEx, NWA, SWA, United, UPS)

• Real-time data access restricted to participating airlines (ESRL web site) and government agencies

– Aircraft obs are largely limited to winds & temp (water vapor is coming)

– Aircraft obs frequently over-reported at airline hubs, and under-reported at less-busy locations

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Desired Future State of MDCRS• Aircraft Weather Observations

– Reported where & when needed through some level of data optimization system

– Implement standardized reporting rate, fidelity, and format.

– Delivered over standardized comm. systems (NOAAport) and available to everyone that desires real-time access

• Implement an enhanced process for allowing additional program participants

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NWS Water Vapor Project• NWS contracts

– Awarded to ARINC for installation of 31 water vapor sensors on SWA aircraft• SWA teaming with ARINC and SpectraSensors on installation

and certification issues for the sensor– Awarded upgrade to UPS to retrofit 25 current water

vapor sensors on UPS aircraft with newly upgraded sensor.

• Schedule– First SWA aircraft reporting water vapor data in February

2010.– Second SWA aircraft began reporting in late March 2010.– Remaining 29 SWA aircraft to be installed at the rate of

approximately 1 aircraft per month.

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2009 Flight Delays - Weather Related

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25

30

35

40

45

50

Per

cen

tag

e o

f al

l D

elay

s (%

)

SWA

Industry

Source: FAA - RITA

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SWA Ongoing Meteorology Challenges

• Minimizing forecast variation for single station– TAF’s and more (Gridded Fcst, Zone Fcst, AFD, CCFP, SPC,

etc.)• TAF still makes dispatchers world go round• However, now more frequently utilizing other products (This is a

good thing)• Can be significant variation in forecast products (at terminal or

within the local airspace)

• Local Effects (terrain, lake/ocean boundaries)• Winter Weather

– Ice (Never clear cut; fine line between nuisance and major problem)

– Precipitation Type (Snow, Freezing Rain, Mixed)– Terminator/Originator Decisions

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SWA Columbus Operations

• SWA occupies 3 gates at Port Columbus Airport.• 5 terminating aircraft scheduled per night.• 25 flight arrivals per day.• All airplane de-icing is at the gate by SWA

employees.• SWA has 105 employees at CMH.

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Columbus “Issues”

• Often on the borderline between rain, snow and mixed precipitation.

• A “popular” SWA diversion city.• A station that is often “below the radar”.

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SWA Partnership with the NWS

• We only use NWS TAFs for operational decision making.• Participation in meetings and workshops to communicate

SWA operational decision criteria to NWS forecasters so they can better understand our use of their products.

• Always looking for ways to help promote NWS efforts.• Assist with all levels of the NWS concerning aviation

community usage of products and services.• SWA entered into an agreement with the NWS to install

water vapor sensors aboard 31 aircraft and report data during all flight phases for use by forecasters and forecasting models.

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Additional NWS support• TAF Suggestions

– Utilization of VCTS, VCSH, and CB in TAF can be very helpful– Amend in timely manner when necessary, even if near end of

TAF cycle (Important with regard to planning for fuel load!)– Watch Winter weather closely in terms of type(s) of precipitation

included and the timing; TAF as consistent as possible with other products.

• Aviation portion of AFD can be 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 in aviation section is VERY helpful

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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 site graphics and details for ongoing events……many offices now do that…..again tremendously helpful.