Weather and Tools for Ballooning Mark Roberson

FAR Part Preflight Action Each pilot in command shall, before beginning a flight, become familiar with all available information concerning that flight. This information must include— For civil aircraft other than those specified in paragraph (b)(1) of this section, other reliable information appropriate to the aircraft, relating to aircraft performance under expected values of airport (field) elevation, aircraft gross weight, wind and temperature.

Wx Tool Box Thought process – inverted triangle Gathering wx data and forecast information The internet Identifying RED FLAGS Time to fly

The forest for the trees

Words of Wx Wisdom "Understanding current conditions is the starting point, and the most critical part, of any weather forecast."

Wx Triangle

National Weather

Regional

Local

Balloon Weather and the Internet All forecasts are not created equally

Internet Weather – A great resource when used wisely Easy access, PCs, laptops, cell phones, etc. Forecasts, radar, satellite, current conditions all available with just a few clicks Access to new experimental forecast information Available almost anywhere you fly

Who makes Internet weather forecasts? National Weather Service Private Weather Services Universities Government organizations/research

This is “who” really makes internet forecasts…..

…..and a Good Computer Geek

How are Internet Weather Forecasts Made? Almost all are automated, NO HUMAN INTERFACE Database driven Updated when computer models are completed (many different models) Based on either the NWS database or proprietary models owned/run by private weather services Some “fudging” involved

Recipe for Internet forecasts

Forecast

Even Weather Maps are Automated

Computer Models ETA/NAM GFS NOGAPS Canadian ECWMF UKMET NGM MM5 …and others..

Internet Forecasts Different websites may use different models Most or all websites will not change to particular model on a day by day basis Most websites use a “blend” of the computer model information

Who uses what Weather.com (aka, The Weather Channel) – stopped using NWS forecasts, uses own model Weather Underground – NWS Accuweather – own model Intellicast – owned by weather.com WSI – owned by weather.com CNN, FOX, etc. usually contracts with above vendors National Weather Service – taxpayer provided database, resources, etc.

Accuracy?

Points to Ponder Pilots who obtain internet forecasts from commercial providers should use the information ONLY as a guide Many internet forecasts do not contain other elements such as wind forecasts Add the human element whenever possible, either yourself or a weather briefer

Ask the Briefer Fronts/troughs within 50 miles of launch site? Low pressure centers within 50 miles of launch site? Precipitation/virga on radar within 50 miles of launch site?

Info from the Briefer 1,000ft winds, greater than 20 mph? 3,000ft winds, greater than 50 mph? Precipitation? Visibility less than 5 miles? Temperature and Dewpoint difference 5 degrees or less? Wind Speed greater than 10 mph? Wind Direction from an easterly direction? Large pressure differences? TAFS

What is an Outflow Boundary? Thunderstorms often push a mass of cold dense air ahead of them generated by the cooling effect of the rain. These are called outflows.

When and Where Do They Occur? Sometimes in a 360 degree radius around thunderstorms Rain showers Virga

Development of Outflow

Outflow Diagram

Outflow

Cold air begins to descend from the middle and upper levels of a thunderstorm. As the colder air strikes the Earth's surface, it begins to “roll”, much like water as a boat moves through it. As the colder air “rolls” out, it is compressed causing winds to increase dramatically - at times even stronger than a hurricane!

Virga Can Produce Outflow

What Do Outflows Look Like?

Examples:

Real Life Examples - Hot Air Balloons On June 8, 1997 the Great Plains Balloon Race was being held just south of Sioux Falls. The evening balloon flight was expected to be rather tranquil. Instead, a surprise gust front from two isolated thunderstorms caused some balloons to land with speeds approaching 30 mph. The outflows from these two small storms traveled for four to five hours merging and intensifying as they reached Sioux Falls. The two gust fronts continued to move across South Dakota and were about half way across the state, before they finally died out. South Dakota is about 400 miles wide. The front traveled in excess of 350 miles. Most of the rest of the travel was after sunset.

Saturday, July 15, 1995 at DEERFIELD, MA The pilot arrived at a balloon festival at 5:30 am and obtained a weather briefing from three other pilots and the Balloon Meister. He determined that thunderstorms were due in the area at about 10:00 am.

Saturday, July 15, 1995 at DEERFIELD, MA (Cont.) He departed with two passengers at 6:20 am. The pilot subsequently encountered a wind shift and strong gusting winds. He reported that the balloon throat closed due to the winds. After that, the balloon began descending and collided with trees.

Saturday, July 15, 1995 at DEERFIELD, MA (Cont.) About 25 miles south at Westfield, Ma, the 6:45 am wind was from 090 degrees at 5 knots; at 7:45 am, the wind had changed to 360 degrees at 20 knots with gusts to 40 knots.

Saturday, July 15, 1995 at DEERFIELD, MA (Cont.) About 50 miles northwest of the departure point at Albany, severe thunderstorms with heavy rain and wind squalls were reported at 6:50 am. The peak wind at Albany was reported to be from 310 degrees at 67 knots at 6:41am.

Forecasting Outflow Boundaries Know if thunderstorms are possible in a 360 degree radius from launch site Are thunderstorms going to occur overnight or during the morning? Watch the sky - Is there virga, dissipating thunderstorms or showers in the area? Remember….in a 360 degree radius Check radar and satellite images Ask briefer if outflow boundaries are present or HAVE been detected overnight/within 3 to 6 hours of launch

Tools to Detect Outflow NEXRAD Radar Surface Observations Your Eyes Your Crew

NEXRAD Radar - Coverage

NEXRAD Radar - Examples

NEXRAD Radar – Examples- 360 degrees

NEXRAD Radar – Examples

Surface Observations Are there any locations reporting current thunderstorm activity or recent activity? Are there any reporting stations in a 360 degree radius reporting strong winds gusts or erratic winds? Are you in an area with complex topography which may intensify outflow speeds?

Your Eyes Scan the horizon- do you see areas of dust on the horizon Do you see low clouds with ragged edges? Do you see virga? Do you see towering Cumulus or CB’s in the distance (in a 360 degree radius)

Your Crew Rapid increase in surface wind Dust on the horizon Other balloons in the air showing a rapid increase in air speed

Wx websites bin/findweather/hdfForecast?query=orl&se archType=WEATHER bin/launch/code.cgi?Submit=Go&sta=KGI F&model=avn&state=FL nesstraveler/local/USFL0372?from=recent search

Wx websites continued her.pl?st=fl&icao1=KMCO&icao2=KGIF &icao3=KMCO&fb1=KMLB&fb2=KPIE& fb3=KJAX&When=TM&Submit=Get+Bal loonCast

Questions?