Detailed Predictions for: Timberline
Launch Altitude (f): 5810
LZ Altitude (f): 1840
Sounding

Station:

KOAK

Date/Time:

17 FEB 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)
4 AM Sun 25 25 W 10 3770 5810 0 Blue 0
5 AM Sun 24 24 W 10 3770 5810 0 Blue 0
6 AM Sun 24 24 W 10 3770 5810 0 Blue 0
7 AM Sun 24 24 NW 10 3770 5810 0 Blue 0
8 AM Sun 25 25 NW 10 3770 5810 0 Blue 0
9 AM Sun 26 26 NW 10 3770 5810 0 Blue 0
10 AM Sun 27 27 NW 9 4071 5810 0 Blue 0
11 AM Sun 28 29 NW 9 5087 5810 0 Blue 0
12 Noon Sun 29 30 NW 9 6330 5810 0 Blue 1
1 PM Sun 30 31 NW 12 6818 5810 0 Blue 2
2 PM Sun 30 31 NW 12 6818 5810 0 Blue 2
3 PM Sun 30 30 NW 12 6330 5810 0 Blue 1
4 PM Sun 29 29 NW 10 5087 5810 0 Blue 0
5 PM Sun 28 28 NW 10 4463 5810 0 Blue 0
6 PM Sun 26 26 NW 10 3770 5810 0 Blue 0
7 PM Sun 25 25 N 13 3770 5810 0 Blue 0
8 PM Sun 24 24 N 13 3770 5810 0 Blue 0
9 PM Sun 24 24 N 13 3770 5810 0 Blue 0
10 PM Sun 24 24 N 17 3770 5810 0 Blue 0
11 PM Sun 23 23 N 17 3770 5810 0 Blue 0
12 Midnight Mon 23 23 N 17 3770 5810 0 Blue 0
1 AM Mon 22 22 N 17 3770 5810 0 Blue 0
2 AM Mon 22 22 N 17 3770 5810 0 Blue 0
3 AM Mon 22 22 N 17 3770 5810 0 Blue 0
4 AM Mon 22 22 N 12 3770 5810 0 Blue 0
5 AM Mon 22 22 N 12 3770 5810 0 Blue 0
6 AM Mon 22 22 N 12 3770 5810 0 Blue 0
7 AM Mon 23 23 N 12 3770 5810 0 Blue 0
8 AM Mon 24 24 N 12 3770 5810 0 Blue 0
9 AM Mon 27 28 N 12 4463 5810 0 Blue 0
10 AM Mon 29 31 N 9 6818 5810 0 Blue 2
11 AM Mon 31 34 N 9 7606 6797 987 White 5
12 Noon Mon 34 37 N 9 8253 8141 2331 White 8
1 PM Mon 35 38 N 9 8468 8468 2658 White 9
2 PM Mon 36 38 N 9 8468 8468 2658 White 9
3 PM Mon 36 37 N 9 8253 8141 2331 White 8
4 PM Mon 35 35 N 9 7821 7101 1291 White 6
5 PM Mon 33 33 N 9 7389 6301 491 White 4
6 PM Mon 31 31 N 9 6818 5810 0 Blue 2
7 PM Mon 29 29 N 9 5087 5810 0 Blue 0
8 PM Mon 28 28 N 9 4463 5810 0 Blue 0
9 PM Mon 27 27 N 9 4071 5810 0 Blue 0
10 PM Mon 27 27 N 10 4071 5810 0 Blue 0
11 PM Mon 26 26 N 10 3770 5810 0 Blue 0
12 Midnight Tue 25 25 N 10 3770 5810 0 Blue 0
1 AM Tue 25 25 N 10 3770 5810 0 Blue 0
2 AM Tue 25 25 N 10 3770 5810 0 Blue 0
3 AM Tue 25 25 N 10 3770 5810 0 Blue 0
4 AM Tue 25 25 NE 8 3770 5810 0 Blue 0
5 AM Tue 24 24 NE 8 3770 5810 0 Blue 0
6 AM Tue 24 24 NE 8 3770 5810 0 Blue 0
7 AM Tue 24 24 NE 8 3770 5810 0 Blue 0
8 AM Tue 26 26 NE 8 3770 5810 0 Blue 0
9 AM Tue 28 28 NE 8 4463 5810 0 Blue 0
10 AM Tue 31 33 N 8 7389 6301 491 White 4
11 AM Tue 34 36 N 8 8038 7403 1593 White 7
12 Noon Tue 36 39 N 8 8683 8683 2873 White 10
1 PM Tue 38 41 N 8 9109 9109 3299 White 12
2 PM Tue 38 40 N 8 8897 8897 3087 White 11
3 PM Tue 37 38 N 8 8468 8468 2658 White 9
4 PM Tue 36 36 W 8 8038 7403 1593 White 7
5 PM Tue 34 34 W 8 7606 6797 987 White 5
6 PM Tue 32 32 W 8 7126 5810 0 Blue 3
7 PM Tue 31 31 W 8 6818 5810 0 Blue 2
8 PM Tue 30 30 W 8 6330 5810 0 Blue 1
9 PM Tue 30 30 W 8 6330 5810 0 Blue 1
10 PM Tue 30 30 NE 6 6330 5810 0 Blue 1
11 PM Tue 29 29 NE 6 5087 5810 0 Blue 0
12 Midnight Wed 29 29 NE 6 5087 5810 0 Blue 0
1 AM Wed 28 28 NE 6 4463 5810 0 Blue 0
2 AM Wed 28 28 NE 6 4463 5810 0 Blue 0
3 AM Wed 28 28 NE 6 4463 5810 0 Blue 0
4 AM Wed 27 27 N 8 4071 5810 0 Blue 0
5 AM Wed 26 26 N 8 3770 5810 0 Blue 0
6 AM Wed 26 26 N 8 3770 5810 0 Blue 0
7 AM Wed 26 26 N 8 3770 5810 0 Blue 0
8 AM Wed 27 27 N 8 4071 5810 0 Blue 0
9 AM Wed 29 29 N 8 5087 5810 0 Blue 0
10 AM Wed 31 31 W 12 6818 5810 0 Blue 2
11 AM Wed 32 33 W 12 7389 6301 491 White 4
12 Noon Wed 33 34 W 12 7606 6797 987 White 5
1 PM Wed 34 35 W 12 7821 7101 1291 White 6
2 PM Wed 34 35 W 12 7821 7101 1291 White 6
3 PM Wed 34 34 W 12 7606 6797 987 White 5
4 PM Wed 33 33 NW 17 7389 6301 491 White 4
5 PM Wed 31 31 NW 17 6818 5810 0 Blue 2
6 PM Wed 29 29 NW 17 5087 5810 0 Blue 0
7 PM Wed 28 28 NW 17 4463 5810 0 Blue 0
8 PM Wed 27 27 NW 17 4071 5810 0 Blue 0
9 PM Wed 26 26 NW 17 3770 5810 0 Blue 0
10 PM Wed 25 25 NW 14 3770 5810 0 Blue 0
11 PM Wed 25 25 NW 14 3770 5810 0 Blue 0
12 Midnight Thu 24 24 NW 14 3770 5810 0 Blue 0
1 AM Thu 24 24 NW 14 3770 5810 0 Blue 0
2 AM Thu 25 25 NW 14 3770 5810 0 Blue 0
3 AM Thu 25 25 NW 14 3770 5810 0 Blue 0
4 AM Thu 25 25 NW 13 3770 5810 0 Blue 0
5 AM Thu 25 25 NW 13 3770 5810 0 Blue 0
6 AM Thu 24 24 NW 13 3770 5810 0 Blue 0
7 AM Thu 24 24 NW 13 3770 5810 0 Blue 0
8 AM Thu 25 25 NW 13 3770 5810 0 Blue 0
9 AM Thu 27 27 NW 13 4071 5810 0 Blue 0
10 AM Thu 29 30 N 14 6330 5810 0 Blue 1
11 AM Thu 30 31 N 14 6818 5810 0 Blue 2
12 Noon Thu 32 34 N 14 7606 6797 987 White 5
1 PM Thu 32 34 N 14 7606 6797 987 White 5
2 PM Thu 33 34 N 14 7606 6797 987 White 5
3 PM Thu 33 34 N 14 7606 6797 987 White 5
4 PM Thu 32 32 N 14 7126 5810 0 Blue 3
5 PM Thu 31 31 N 14 6818 5810 0 Blue 2
6 PM Thu 29 29 N 14 5087 5810 0 Blue 0
7 PM Thu 27 27 N 14 4071 5810 0 Blue 0
8 PM Thu 27 27 N 14 4071 5810 0 Blue 0
9 PM Thu 26 26 N 14 3770 5810 0 Blue 0
10 PM Thu 27 27 E 13 4071 5810 0 Blue 0
11 PM Thu 26 26 E 13 3770 5810 0 Blue 0
12 Midnight Fri 26 26 E 13 3770 5810 0 Blue 0
1 AM Fri 26 26 E 13 3770 5810 0 Blue 0
2 AM Fri 26 26 E 13 3770 5810 0 Blue 0
3 AM Fri 25 25 E 13 3770 5810 0 Blue 0
4 AM Fri 25 25 NW 10 3770 5810 0 Blue 0
5 AM Fri 24 24 NW 10 3770 5810 0 Blue 0
6 AM Fri 24 24 NW 10 3770 5810 0 Blue 0
7 AM Fri 24 24 NW 10 3770 5810 0 Blue 0
8 AM Fri 26 26 NW 10 3770 5810 0 Blue 0
9 AM Fri 28 28 NW 10 4463 5810 0 Blue 0
10 AM Fri 31 32 SW 8 7126 5810 0 Blue 3
11 AM Fri 33 35 SW 8 7821 7101 1291 White 6
12 Noon Fri 35 37 SW 8 8253 8141 2331 White 8
1 PM Fri 36 38 SW 8 8468 8468 2658 White 9
2 PM Fri 37 38 SW 8 8468 8468 2658 White 9
3 PM Fri 38 39 SW 8 8683 8683 2873 White 10
4 PM Fri 38 38 SW 8 8468 8468 2658 White 9
5 PM Fri 36 36 SW 8 8038 7403 1593 White 7
6 PM Fri 34 34 SW 8 7606 6797 987 White 5
7 PM Fri 32 32 SW 8 7126 5810 0 Blue 3
8 PM Fri 31 31 SW 8 6818 5810 0 Blue 2
9 PM Fri 30 30 SW 8 6330 5810 0 Blue 1
10 PM Fri 30 30 W 9 6330 5810 0 Blue 1
11 PM Fri 30 30 W 9 6330 5810 0 Blue 1
12 Midnight Sat 30 30 W 9 6330 5810 0 Blue 1
1 AM Sat 29 29 W 9 5087 5810 0 Blue 0
2 AM Sat 29 29 W 9 5087 5810 0 Blue 0
3 AM Sat 29 29 W 9 5087 5810 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