Detailed Predictions for: BJ
Launch Altitude (f): 582
LZ Altitude (f): 180
Sounding

Station:

KOTX

Date/Time:

21 AUG 2019

Temp/Wind data from:

NOAA Digital Forecast

Site Forecasts
Time
(Local)
High
Temp

Puddle
Temp

Wind
(mph)
Thermal
Ceiling

(ft)
Soaring
Ceiling

(ft)
Above
Launch

(ft)
Thermal
Type
Thermal
Index

(F)
5 AM Wed 58 58 S 2 0 582 0 Blue 0
6 AM Wed 59 59 S 2 0 582 0 Blue 0
7 AM Wed 58 58 S 2 0 582 0 Blue 0
8 AM Wed 59 59 SW 1 0 582 0 Blue 0
9 AM Wed 61 61 SW 1 0 582 0 Blue 0
10 AM Wed 62 62 SW 1 0 582 0 Blue 0
11 AM Wed 63 63 S 9 0 582 0 Blue 0
12 Noon Wed 64 64 S 9 0 582 0 Blue 0
1 PM Wed 65 65 S 9 2391 2388 1806 Blue 0
2 PM Wed 65 65 SW 8 2391 2388 1806 Blue 0
3 PM Wed 64 64 SW 8 0 582 0 Blue 0
4 PM Wed 65 65 SW 8 2391 2388 1806 Blue 0
5 PM Wed 64 64 S 8 0 582 0 Blue 0
6 PM Wed 65 65 S 8 2391 2388 1806 Blue 0
7 PM Wed 64 64 S 8 0 582 0 Blue 0
8 PM Wed 61 61 S 9 0 582 0 Blue 0
9 PM Wed 60 60 S 9 0 582 0 Blue 0
10 PM Wed 58 58 S 9 0 582 0 Blue 0
11 PM Wed 57 57 S 6 0 582 0 Blue 0
12 Midnight Thu 58 58 S 6 0 582 0 Blue 0
1 AM Thu 56 56 S 6 0 582 0 Blue 0
2 AM Thu 56 56 S 5 0 582 0 Blue 0
3 AM Thu 56 56 S 5 0 582 0 Blue 0
4 AM Thu 54 54 S 5 0 582 0 Blue 0
5 AM Thu 54 54 S 7 0 582 0 Blue 0
6 AM Thu 56 56 S 7 0 582 0 Blue 0
7 AM Thu 55 55 S 7 0 582 0 Blue 0
8 AM Thu 57 57 S 8 0 582 0 Blue 0
9 AM Thu 60 60 S 8 0 582 0 Blue 0
10 AM Thu 61 61 S 8 0 582 0 Blue 0
11 AM Thu 64 65 SW 8 2391 2388 1806 Blue 0
12 Noon Thu 66 68 SW 8 2407 2391 1809 Blue 3
1 PM Thu 66 68 SW 8 2407 2391 1809 Blue 3
2 PM Thu 68 71 W 8 2422 2406 1824 Blue 6
3 PM Thu 65 67 W 8 2401 2388 1806 Blue 2
4 PM Thu 67 68 W 8 2407 2391 1809 Blue 3
5 PM Thu 67 68 SW 3 2407 2391 1809 Blue 3
6 PM Thu 67 67 SW 3 2401 2388 1806 Blue 2
7 PM Thu 66 66 SW 3 2396 2388 1806 Blue 1
8 PM Thu 61 61 SW 3 0 582 0 Blue 0
9 PM Thu 59 59 SW 3 0 582 0 Blue 0
10 PM Thu 57 57 SW 3 0 582 0 Blue 0
11 PM Thu 56 56 SW 2 0 582 0 Blue 0
12 Midnight Fri 56 56 SW 2 0 582 0 Blue 0
1 AM Fri 54 54 SW 2 0 582 0 Blue 0
2 AM Fri 53 53 SW 2 0 582 0 Blue 0
3 AM Fri 54 54 SW 2 0 582 0 Blue 0
4 AM Fri 51 51 SW 2 0 582 0 Blue 0
5 AM Fri 51 51 SW 1 0 582 0 Blue 0
6 AM Fri 53 53 SW 1 0 582 0 Blue 0
7 AM Fri 52 52 SW 1 0 582 0 Blue 0
8 AM Fri 54 54 SW 1 0 582 0 Blue 0
9 AM Fri 58 58 SW 1 0 582 0 Blue 0
10 AM Fri 59 59 SW 1 0 582 0 Blue 0
11 AM Fri 63 64 SW 5 0 582 0 Blue 0
12 Noon Fri 66 67 SW 5 2401 2388 1806 Blue 2
1 PM Fri 67 68 SW 5 2407 2391 1809 Blue 3
2 PM Fri 69 70 SW 5 2417 2401 1819 Blue 5
3 PM Fri 66 67 SW 5 2401 2388 1806 Blue 2
4 PM Fri 68 69 SW 5 2412 2396 1814 Blue 4
5 PM Fri 67 68 SW 6 2407 2391 1809 Blue 3
6 PM Fri 68 68 SW 6 2407 2391 1809 Blue 3
7 PM Fri 66 66 SW 6 2396 2388 1806 Blue 1
8 PM Fri 62 62 SW 6 0 582 0 Blue 0
9 PM Fri 60 60 SW 6 0 582 0 Blue 0
10 PM Fri 57 57 SW 6 0 582 0 Blue 0
11 PM Fri 56 56 S 6 0 582 0 Blue 0
12 Midnight Sat 57 57 S 6 0 582 0 Blue 0
1 AM Sat 54 54 S 6 0 582 0 Blue 0
2 AM Sat 53 53 S 6 0 582 0 Blue 0
3 AM Sat 54 54 S 6 0 582 0 Blue 0
4 AM Sat 51 51 S 6 0 582 0 Blue 0
5 AM Sat 51 51 S 6 0 582 0 Blue 0
6 AM Sat 53 53 S 6 0 582 0 Blue 0
7 AM Sat 52 52 S 6 0 582 0 Blue 0
8 AM Sat 54 54 S 6 0 582 0 Blue 0
9 AM Sat 58 58 S 6 0 582 0 Blue 0
10 AM Sat 59 60 S 6 0 582 0 Blue 0
11 AM Sat 63 64 SW 8 0 582 0 Blue 0
12 Noon Sat 65 66 SW 8 2396 2388 1806 Blue 1
1 PM Sat 66 67 SW 8 2401 2388 1806 Blue 2
2 PM Sat 68 69 SW 8 2412 2396 1814 Blue 4
3 PM Sat 66 67 SW 8 2401 2388 1806 Blue 2
4 PM Sat 67 68 SW 8 2407 2391 1809 Blue 3
5 PM Sat 67 67 S 8 2401 2388 1806 Blue 2
6 PM Sat 67 67 S 8 2401 2388 1806 Blue 2
7 PM Sat 66 66 S 8 2396 2388 1806 Blue 1
8 PM Sat 62 62 S 8 0 582 0 Blue 0
9 PM Sat 60 60 S 8 0 582 0 Blue 0
10 PM Sat 57 57 S 8 0 582 0 Blue 0
11 PM Sat 57 57 S 6 0 582 0 Blue 0
12 Midnight Sun 57 57 S 6 0 582 0 Blue 0
1 AM Sun 55 55 S 6 0 582 0 Blue 0
2 AM Sun 54 54 S 6 0 582 0 Blue 0
3 AM Sun 55 55 S 6 0 582 0 Blue 0
4 AM Sun 52 52 S 6 0 582 0 Blue 0
5 AM Sun 52 52 S 7 0 582 0 Blue 0
6 AM Sun 54 54 S 7 0 582 0 Blue 0
7 AM Sun 53 53 S 7 0 582 0 Blue 0
8 AM Sun 55 55 S 7 0 582 0 Blue 0
9 AM Sun 58 58 S 7 0 582 0 Blue 0
10 AM Sun 59 60 S 7 0 582 0 Blue 0
11 AM Sun 62 63 SW 8 0 582 0 Blue 0
12 Noon Sun 64 66 SW 8 2396 2388 1806 Blue 1
1 PM Sun 65 67 SW 8 2401 2388 1806 Blue 2
2 PM Sun 67 69 SW 8 2412 2396 1814 Blue 4
3 PM Sun 64 65 SW 8 2391 2388 1806 Blue 0
4 PM Sun 66 67 SW 8 2401 2388 1806 Blue 2
5 PM Sun 66 67 S 7 2401 2388 1806 Blue 2
6 PM Sun 66 66 S 7 2396 2388 1806 Blue 1
7 PM Sun 65 65 S 7 2391 2388 1806 Blue 0
8 PM Sun 60 60 S 7 0 582 0 Blue 0
9 PM Sun 58 58 S 7 0 582 0 Blue 0
10 PM Sun 56 56 S 7 0 582 0 Blue 0
11 PM Sun 55 55 S 8 0 582 0 Blue 0
12 Midnight Mon 55 55 S 8 0 582 0 Blue 0
1 AM Mon 53 53 S 8 0 582 0 Blue 0
2 AM Mon 52 52 S 8 0 582 0 Blue 0
3 AM Mon 53 53 S 8 0 582 0 Blue 0
4 AM Mon 50 50 S 8 0 582 0 Blue 0
5 AM Mon 50 50 S 6 0 582 0 Blue 0
6 AM Mon 52 52 S 6 0 582 0 Blue 0
7 AM Mon 51 51 S 6 0 582 0 Blue 0
8 AM Mon 54 54 S 6 0 582 0 Blue 0
9 AM Mon 59 60 S 6 0 582 0 Blue 0
10 AM Mon 60 62 S 6 0 582 0 Blue 0
11 AM Mon 65 68 W 8 2407 2391 1809 Blue 3
12 Noon Mon 68 71 W 8 2422 2406 1824 Blue 6
1 PM Mon 69 73 W 8 2433 2417 1835 Blue 8
2 PM Mon 72 76 W 8 2454 2433 1851 Blue 11
3 PM Mon 69 72 W 8 2428 2412 1830 Blue 7
4 PM Mon 71 73 W 8 2433 2417 1835 Blue 8
5 PM Mon 70 72 W 5 2428 2412 1830 Blue 7
6 PM Mon 71 72 W 5 2428 2412 1830 Blue 7
7 PM Mon 69 69 W 5 2412 2396 1814 Blue 4
8 PM Mon 64 64 W 5 0 582 0 Blue 0
9 PM Mon 61 61 W 5 0 582 0 Blue 0
10 PM Mon 58 58 W 5 0 582 0 Blue 0
11 PM Mon 57 57 NE 8 0 582 0 Blue 0
12 Midnight Tue 57 57 NE 8 0 582 0 Blue 0
1 AM Tue 55 55 NE 8 0 582 0 Blue 0
2 AM Tue 54 54 NE 8 0 582 0 Blue 0
3 AM Tue 55 55 NE 8 0 582 0 Blue 0
4 AM Tue 51 51 NE 8 0 582 0 Blue 0

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 website.  Puddle temperatures can exceed this temperature. 

Puddle Temp: This estimate is based on the High Temp and the National Weather Service 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 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 ac_soaring@yahoo.com