Feb 16, 2021
- Problems getting data from National Weather Service began on Feb 11 impacting operation of the Soaring Predictor software.
The service seems to be working again at about 75% as of this morning, Feb 16.

Backup data is being sourced from however, their free service is limited to 3 days. If you see a three day forecast for your favorite site, thank the WeatherAPI folks. The full 5-day forecasts are receiving input data from the National Weather service (thank them too :-).



KTUS (alt)


26 SEP 2022

Temp/Wind data from:

NOAA Digital Forecast
Mon Tue Wed Thu Fri Sat
Wind Above
Wind Above
Wind Above
Wind Above
Wind Above
Wind Above
South Mountain SSE 26 9622 ESE 18 8184 E 11 6825 E 8 3707 E 5 3707 ESE 6 3707
Oatman Mt ENE 11 9471 E 13 9675 E 10 9267
Shaw Butte SE 12 10539 E 13 10539 ESE 13 10739
The Y SE 15 11671 SE 11 10663 ESE 15 11271
Phoenix Regional SE 18 0 SE 14 0 SE 14 0
Humbolt NNE 11 12223 SE 11 11824 ESE 13 11824
Miller Canyon ESE 21 10321 E 19 9705 ESE 19 10116
Box Canyon ESE 22 11632 E 19 11029 SE 19 11230
Mustang Mountain ESE 17 10604 ESE 17 9789 ESE 11 9789
Whetstone Mountain E 19 8440 E 18 8440 ESE 18 3699 E 11 1022 ESE 10 1766 E 9 3699
Mt Lemmon ESE 21 6315 ESE 16 6100 E 18 3128 E 13 723 E 11 2421 E 10 2421
A Mountain ESE 19 11902 E 17 11100 SE 17 11302
Rainbow Valley ESE 14 0 ESE 20 0 E 10 0 E 6 1935 SE 5 1935 SSE 5 3461
Pinal Peak ENE 16 6640 E 19 4507 ESE 19 3650 E 14 797 ESE 10 2114 E 8 2114
Harquahala ESE 12 11205 SE 17 11406 ESE 18 11406
El Tiro Gliderport SE 19 9250 S 18 9044 SE 12 7751 SE 6 3710 SE 5 4456 NW 6 5828
Mt Ord ESE 18 8188 SE 19 8188 ESE 14 7979 ENE 10 7558 NE 9 7558 ENE 8 7558

DISCLAIMER: These estimates are intended to assist in daily site selection only.  No warranty is made concerning the accuracy of these estimates.  These estimates cannot be used to determine if conditions are safe for flying.  Conditions should be evaluated at the launch site by experienced pilots before launching.

Sounding: This is the site at which the weather balloon was released.  If the flying site predicted is far from the sounding site, the estimate is not valid.  Also, the sounding is done at 12Z (4AM PST).  If a front comes through, the sounding is no longer valid. The sounding becomes less valid later in the day.

Thermal Ceiling: the lower of the height at which the thermal stops rising and the cloud level.  We can't fly into the clouds, so it doesn't matter how much higher the thermal goes.  Remember that we can't get to the top of the thermal because of our sink rate.  Our upper limit will be lower than the reported ceiling.

Soaring Ceiling: We will stop going up when the thermal is rising just fast enough to offset our sink.  It is estimated that this happens when the temperature difference between the thermal and the surrounding air is about 2 degrees F. This number is an estimate of the maximum altitude we might reach if we start at launch height, and should be more reflective of our chances of soaring than the thermal top. Please let me know how this compares with actually flying, and I will adjust it as necessary.

Above Launch: The difference between how high we might get and how high we start. This estimate does not account for ridge lift.

High Temp: This estimate is taken from the National Weather Service or website.  Puddle temperatures can exceed this temperature. 

Puddle Temp: This estimate is based on the High Temp and the National Weather Service or estimate of cloudiness, and the angle of the sun.  When the sun is directly overhead on a sunny day, the puddle temp is esimated to be 25 degrees warmer than the high ambient temperature. This estimate now includes a rigorous calculation of the Sun Angle, and accounts for the seasonal differences in zenith and daylight hours.

Wind: This estimate is taken from the National Weather Service or website.

Wind Gust: This estimate is taken from the National Weather Service or website.

Thermal Type: Blue (no cloud formation) or White (Cloud formation)

Thermal Index: This is the maximum difference in temperature between the rising packet of air (the thermal) and the surrounding air.  The difference in temperature is responsible for the buoyancy of the thermal, and larger temperature differences mean faster rising thermals.  A value of about 10 F or greater often means that the conditions are soarable.  Values above 20 could indicate rowdy thermals.

Validity of estimate: Many factors (including strong wind, fronts, cloud shadows, incorrectly predicted temperatures, etc) can affect the validity of the estimates. 

Author: Tad Hurst

Supported By: Alan Crouse [email protected]