Vienna Wireless Society, VWS-8 Balloon Flight Predictions

Launch is currently scheduled for Saturday morning, May 1, 2010, at around 9:00 AM
The parameters used in estimating flight are 289 cubic feet of helium into a 3000 gram Kaymont balloon. With a 3.75 pound payload, this yields an ascent rate of 1310 feet per minute and a burst altitude of 114,000 feet.
Pete Norloff, KG4OJT

Saturday night, April 24, at 162 hours the GFS model predicts a 123 mile flight at 88.2 degrees:
The prediction shows burst over Greenbelt, MD, and a landing Centreville, MD.

Sunday night, April 25, at 138 hours the GFS model predicts a 98 mile flight at 76 degrees. This has a more northerly component and slightly slower winds. Wind speeds go from ~50 mph to 100 mph between ground level and 45,000 feet, then slow down aloft.
Burst is over Gaithersburg, and landing inside the Baltimore beltway.


Monday night, April 26, at 114 hours the GFS model predicts a 67 mile flight at 100 degrees. A pretty big departure from yesterday's prediction. This shows both slower winds aloft and a southerly component to the winds that wasn't there yesterday. Wind speeds reach only 70 mph at 45,000 feet.
Burst is over Centreville, VA, and landing is at the intersection of I-395 and Seminary Road.


Tuesday night, April 27, at 90 hours the GFS model predicts an 80 mile flight at 102 degrees. Wind speeds reach 75 mph at 45,000 feet.
Burst is over Centreville, VA, and landing is in Clinton, MD.


Wednesday afternoon, April 28, at 72 hours the GFS model predicts an 69 mile flight at 103 degrees. Wind speeds reach 60 mph at 40,000 feet.
Burst is over Centreville, VA, and landing is Near Huntley Meadows park in Alexandria.


Thursday mid-day, April 29, at 54 hours the GFS model predicts a 69 mile flight at 99 degrees. Wind speeds reach 60 mph at 40,000 feet, the same as yesterday.
Burst is over Centreville, VA, and landing is Near 395 and Quaker Lane in Shirlington.

If you look at the predicted track based on the 1200Z sounding from Dulles this morning (2010-04-29-1200Z), the track today would have been 94 miles at 118 degrees. Winds are reaching 105 mph at 30,000 feet.
Today, burst would have been over Dale City and landing would have been near Chaptico, MD and possibly back in the Wicomico River.


Thursday afternoon, April 29, at 48 hours the GFS model predicts a 70 mile flight at 105 degrees. Wind speeds reach 70 mph at 40,000 feet. These are slightly faster winds and an additional 5 degrees of azimuth from the prediction six hours ago.
Burst is over Centreville, VA, and landing is over in Hybla Valley near Huntley Meadows Park again.


Thursday evening, April 29, at 42 hours the GFS model predicts a 72 mile flight at 102 degrees. Wind speeds reach 80 mph at 40,000 feet. These are slightly faster winds than the prediction six hours ago.
Burst is over Centreville, VA, and landing is in the middle of the Potomac, just south of the Woodrow Wilson Bridge.


Friday Morning, April 30, at 36 hours the GFS model predicts a 70 mile flight at 104 degrees. Wind speeds reach 70 mph at 40,000 feet.
Burst is over Centreville, VA, and landing is in Hybla Valley near Huntley Meadows Park again.

Here's an alternate flight path with the launch moved west to Wardensville, WV. Moving the launch site moves the predicted landing to just south of Fairfax:


Friday Evening, April 30, I've revised the flight parameters to use 230 cubic feet of helium to reduce the ascent rate to 1040 feet per minute and raise the expected burst altitude to 120,000 feet. At 24 hours the GFS model predicts a 81 mile flight at 105 degrees. Wind speeds reach 66 mph at 40,000 feet.
Restoring our launch site to Strasburg, VA, burst is over Burke Lake, and landing is in Brandywine, MD.


Friday Evening, April 30, This morning's sounding from Dulles has no wind data in it, so I ran a prediction using the 1200Z sounding from Wallops Island. If we had flown today, (and the Wallops Island sounding reflected our winds), we would have seen a 122 mile flight at 116 degrees. Wind speeds reached 110 mph at 42,000 feet.
Launching from Strasburg, VA, burst is over Mechanicsville, MD, and landing is in the Bay past Lexington Park, MD.


Friday Evening, April 30,10:50 PM -- At 18 hours the GFS model predicts a 84 mile flight at 104 degrees. Wind speeds reach 67 mph at 40,000 feet.
RLaunching at Strasburg, VA, burst is over Burke, and landing is in Brandywine, MD.


The 0000Z sounding at Dulles Airport indicates higher speed winds aloft. If we flew this afternoon we would have had a 102 mile flight at 107 degrees. Wind speeds reach 90 mph at 43,000 feet.
Launching at Strasburg, VA, burst is over Accokeek, MD and landing is near Prince Frederick, MD. If we had similar winds tomorrow, we'll come very close to dropping in the Bay.

Post Flight:

Click here for selected photos from the VWS-8 Flight