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

Station:

KOAK

Date/Time:

25 APR 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 Thu 54 54 NW 3 3563 5810 0 Blue 0
6 AM Thu 52 52 NW 3 3563 5810 0 Blue 0
7 AM Thu 52 52 NW 3 3563 5810 0 Blue 0
8 AM Thu 54 54 W 3 3563 5810 0 Blue 0
9 AM Thu 57 59 W 3 3563 5810 0 Blue 0
10 AM Thu 60 64 W 3 3563 5810 0 Blue 0
11 AM Thu 63 68 S 5 4879 5810 0 Blue 0
12 Noon Thu 66 72 S 5 9572 6945 1135 Blue 4
1 PM Thu 67 73 S 5 10245 7947 2137 Blue 5
2 PM Thu 68 74 SW 7 11542 8768 2958 Blue 6
3 PM Thu 69 74 SW 7 11542 8768 2958 Blue 6
4 PM Thu 69 73 SW 7 10245 7947 2137 Blue 5
5 PM Thu 68 70 W 8 8046 5810 0 Blue 2
6 PM Thu 67 67 W 8 3896 5810 0 Blue 0
7 PM Thu 65 65 W 8 3563 5810 0 Blue 0
8 PM Thu 63 63 NW 8 3563 5810 0 Blue 0
9 PM Thu 61 61 NW 8 3563 5810 0 Blue 0
10 PM Thu 59 59 NW 8 3563 5810 0 Blue 0
11 PM Thu 58 58 NW 7 3563 5810 0 Blue 0
12 Midnight Fri 57 57 NW 7 3563 5810 0 Blue 0
1 AM Fri 56 56 NW 7 3563 5810 0 Blue 0
2 AM Fri 56 56 NW 7 3563 5810 0 Blue 0
3 AM Fri 55 55 NW 7 3563 5810 0 Blue 0
4 AM Fri 54 54 NW 7 3563 5810 0 Blue 0
5 AM Fri 53 53 N 9 3563 5810 0 Blue 0
6 AM Fri 53 53 N 9 3563 5810 0 Blue 0
7 AM Fri 54 54 N 9 3563 5810 0 Blue 0
8 AM Fri 55 55 N 8 3563 5810 0 Blue 0
9 AM Fri 57 59 N 8 3563 5810 0 Blue 0
10 AM Fri 60 63 N 8 3563 5810 0 Blue 0
11 AM Fri 62 67 NW 6 3896 5810 0 Blue 0
12 Noon Fri 64 70 NW 6 8046 5810 0 Blue 2
1 PM Fri 65 72 NW 6 9572 6945 1135 Blue 4
2 PM Fri 66 72 NW 6 9572 6945 1135 Blue 4
3 PM Fri 67 72 NW 6 9572 6945 1135 Blue 4
4 PM Fri 67 71 NW 6 8863 5810 0 Blue 3
5 PM Fri 66 68 W 7 4879 5810 0 Blue 0
6 PM Fri 65 65 W 7 3563 5810 0 Blue 0
7 PM Fri 62 62 W 7 3563 5810 0 Blue 0
8 PM Fri 60 60 W 7 3563 5810 0 Blue 0
9 PM Fri 58 58 W 7 3563 5810 0 Blue 0
10 PM Fri 57 57 W 7 3563 5810 0 Blue 0
11 PM Fri 56 56 S 7 3563 5810 0 Blue 0
12 Midnight Sat 55 55 S 7 3563 5810 0 Blue 0
1 AM Sat 54 54 S 7 3563 5810 0 Blue 0
2 AM Sat 54 54 S 7 3563 5810 0 Blue 0
3 AM Sat 54 54 S 7 3563 5810 0 Blue 0
4 AM Sat 54 54 S 7 3563 5810 0 Blue 0
5 AM Sat 53 53 W 7 3563 5810 0 Blue 0
6 AM Sat 53 53 W 7 3563 5810 0 Blue 0
7 AM Sat 53 53 W 7 3563 5810 0 Blue 0
8 AM Sat 54 54 W 7 3563 5810 0 Blue 0
9 AM Sat 56 58 W 7 3563 5810 0 Blue 0
10 AM Sat 59 62 W 7 3563 5810 0 Blue 0
11 AM Sat 61 66 W 8 3563 5810 0 Blue 0
12 Noon Sat 63 69 W 8 7021 5810 0 Blue 1
1 PM Sat 64 70 W 8 8046 5810 0 Blue 2
2 PM Sat 65 71 W 8 8863 5810 0 Blue 3
3 PM Sat 65 70 W 8 8046 5810 0 Blue 2
4 PM Sat 65 68 W 8 4879 5810 0 Blue 0
5 PM Sat 64 66 W 8 3563 5810 0 Blue 0
6 PM Sat 62 62 W 8 3563 5810 0 Blue 0
7 PM Sat 60 60 W 8 3563 5810 0 Blue 0
8 PM Sat 58 58 W 8 3563 5810 0 Blue 0
9 PM Sat 56 56 W 8 3563 5810 0 Blue 0
10 PM Sat 55 55 W 8 3563 5810 0 Blue 0
11 PM Sat 53 53 SE 6 3563 5810 0 Blue 0
12 Midnight Sun 53 53 SE 6 3563 5810 0 Blue 0
1 AM Sun 52 52 SE 6 3563 5810 0 Blue 0
2 AM Sun 51 51 SE 6 3563 5810 0 Blue 0
3 AM Sun 51 51 SE 6 3563 5810 0 Blue 0
4 AM Sun 50 50 SE 6 3563 5810 0 Blue 0
5 AM Sun 50 50 NE 7 3563 5810 0 Blue 0
6 AM Sun 50 50 NE 7 3563 5810 0 Blue 0
7 AM Sun 51 51 NE 7 3563 5810 0 Blue 0
8 AM Sun 52 52 NE 7 3563 5810 0 Blue 0
9 AM Sun 54 56 NE 7 3563 5810 0 Blue 0
10 AM Sun 57 60 NE 7 3563 5810 0 Blue 0
11 AM Sun 59 64 S 8 3563 5810 0 Blue 0
12 Noon Sun 61 67 S 8 3896 5810 0 Blue 0
1 PM Sun 62 68 S 8 4879 5810 0 Blue 0
2 PM Sun 63 69 S 8 7021 5810 0 Blue 1
3 PM Sun 64 69 S 8 7021 5810 0 Blue 1
4 PM Sun 64 67 S 8 3896 5810 0 Blue 0
5 PM Sun 63 65 S 8 3563 5810 0 Blue 0
6 PM Sun 61 62 S 8 3563 5810 0 Blue 0
7 PM Sun 59 59 S 8 3563 5810 0 Blue 0
8 PM Sun 56 56 S 8 3563 5810 0 Blue 0
9 PM Sun 55 55 S 8 3563 5810 0 Blue 0
10 PM Sun 54 54 S 8 3563 5810 0 Blue 0
11 PM Sun 53 53 SW 8 3563 5810 0 Blue 0
12 Midnight Mon 52 52 SW 8 3563 5810 0 Blue 0
1 AM Mon 51 51 SW 8 3563 5810 0 Blue 0
2 AM Mon 51 51 SW 8 3563 5810 0 Blue 0
3 AM Mon 51 51 SW 8 3563 5810 0 Blue 0
4 AM Mon 50 50 SW 8 3563 5810 0 Blue 0
5 AM Mon 50 50 N 6 3563 5810 0 Blue 0
6 AM Mon 50 50 N 6 3563 5810 0 Blue 0
7 AM Mon 50 50 N 6 3563 5810 0 Blue 0
8 AM Mon 51 51 N 6 3563 5810 0 Blue 0
9 AM Mon 53 55 N 6 3563 5810 0 Blue 0
10 AM Mon 56 59 N 6 3563 5810 0 Blue 0
11 AM Mon 58 63 W 7 3563 5810 0 Blue 0
12 Noon Mon 60 66 W 7 3563 5810 0 Blue 0
1 PM Mon 61 67 W 7 3896 5810 0 Blue 0
2 PM Mon 62 68 W 7 4879 5810 0 Blue 0
3 PM Mon 62 67 W 7 3896 5810 0 Blue 0
4 PM Mon 62 65 W 7 3563 5810 0 Blue 0
5 PM Mon 61 63 W 9 3563 5810 0 Blue 0
6 PM Mon 59 59 W 9 3563 5810 0 Blue 0
7 PM Mon 57 57 W 9 3563 5810 0 Blue 0
8 PM Mon 54 54 W 9 3563 5810 0 Blue 0
9 PM Mon 53 53 W 9 3563 5810 0 Blue 0
10 PM Mon 51 51 W 9 3563 5810 0 Blue 0
11 PM Mon 50 50 W 9 3563 5810 0 Blue 0
12 Midnight Tue 49 49 W 9 3563 5810 0 Blue 0
1 AM Tue 48 48 W 9 3563 5810 0 Blue 0
2 AM Tue 47 47 W 9 3563 5810 0 Blue 0
3 AM Tue 46 46 W 9 3563 5810 0 Blue 0
4 AM Tue 46 46 W 9 3563 5810 0 Blue 0
5 AM Tue 46 46 NW 9 3563 5810 0 Blue 0
6 AM Tue 45 45 NW 9 3563 5810 0 Blue 0
7 AM Tue 45 45 NW 9 3563 5810 0 Blue 0
8 AM Tue 46 46 NW 9 3563 5810 0 Blue 0
9 AM Tue 47 49 NW 9 3563 5810 0 Blue 0
10 AM Tue 50 53 NW 9 3563 5810 0 Blue 0
11 AM Tue 52 57 W 10 3563 5810 0 Blue 0
12 Noon Tue 54 60 W 10 3563 5810 0 Blue 0
1 PM Tue 55 61 W 10 3563 5810 0 Blue 0
2 PM Tue 55 61 W 10 3563 5810 0 Blue 0
3 PM Tue 56 61 W 10 3563 5810 0 Blue 0
4 PM Tue 56 60 W 10 3563 5810 0 Blue 0
5 PM Tue 55 57 W 10 3563 5810 0 Blue 0
6 PM Tue 54 54 W 10 3563 5810 0 Blue 0
7 PM Tue 52 52 W 10 3563 5810 0 Blue 0
8 PM Tue 50 50 W 10 3563 5810 0 Blue 0
9 PM Tue 48 48 W 10 3563 5810 0 Blue 0
10 PM Tue 46 46 W 10 3563 5810 0 Blue 0
11 PM Tue 45 45 NW 10 3563 5810 0 Blue 0
12 Midnight Wed 44 44 NW 10 3563 5810 0 Blue 0
1 AM Wed 43 43 NW 10 3563 5810 0 Blue 0
2 AM Wed 42 42 NW 10 3563 5810 0 Blue 0
3 AM Wed 42 42 NW 10 3563 5810 0 Blue 0
4 AM Wed 42 42 NW 10 3563 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