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

Station:

KOAK

Date/Time:

23 FEB 2018

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 Fri 23 23 N 15 3921 5810 0 Blue 0
5 AM Fri 22 22 N 15 3921 5810 0 Blue 0
6 AM Fri 22 22 N 15 3921 5810 0 Blue 0
7 AM Fri 23 23 N 15 3921 5810 0 Blue 0
8 AM Fri 25 25 N 15 4503 5810 0 Blue 0
9 AM Fri 29 30 N 15 8160 7137 1327 Blue 4
10 AM Fri 33 35 N 12 9951 8424 2614 White 9
11 AM Fri 36 39 N 12 10787 10773 4963 White 13
12 Noon Fri 38 42 N 12 11410 11410 5600 White 16
1 PM Fri 40 44 N 7 11822 11822 6012 White 18
2 PM Fri 40 43 N 7 11616 11616 5806 White 17
3 PM Fri 40 42 N 7 11410 11410 5600 White 16
4 PM Fri 38 38 NW 6 10579 9944 4134 White 12
5 PM Fri 36 36 NW 6 10161 8715 2905 White 10
6 PM Fri 33 33 NW 6 8755 8146 2336 Blue 7
7 PM Fri 31 31 NW 8 8280 7400 1590 Blue 5
8 PM Fri 30 30 NW 8 8160 7137 1327 Blue 4
9 PM Fri 30 30 NW 8 8160 7137 1327 Blue 4
10 PM Fri 31 31 N 9 8280 7400 1590 Blue 5
11 PM Fri 30 30 N 9 8160 7137 1327 Blue 4
12 Midnight Sat 30 30 N 9 8160 7137 1327 Blue 4
1 AM Sat 30 30 NW 10 8160 7137 1327 Blue 4
2 AM Sat 30 30 NW 10 8160 7137 1327 Blue 4
3 AM Sat 29 29 NW 10 7894 5811 1 Blue 3
4 AM Sat 29 29 NW 12 7894 5811 1 Blue 3
5 AM Sat 28 28 NW 12 7424 5810 0 Blue 2
6 AM Sat 28 28 NW 12 7424 5810 0 Blue 2
7 AM Sat 28 28 NW 13 7424 5810 0 Blue 2
8 AM Sat 29 29 NW 13 7894 5811 1 Blue 3
9 AM Sat 31 31 NW 13 8280 7400 1590 Blue 5
10 AM Sat 33 34 W 14 9071 8265 2455 Blue 8
11 AM Sat 34 35 W 14 9951 8424 2614 White 9
12 Noon Sat 35 36 W 14 10161 8715 2905 White 10
1 PM Sat 36 37 W 15 10369 9004 3194 White 11
2 PM Sat 36 37 W 15 10369 9004 3194 White 11
3 PM Sat 36 36 W 15 10161 8715 2905 White 10
4 PM Sat 35 35 NW 15 9951 8424 2614 White 9
5 PM Sat 33 33 NW 15 8755 8146 2336 Blue 7
6 PM Sat 32 32 NW 15 8462 7840 2030 Blue 6
7 PM Sat 30 30 NW 15 8160 7137 1327 Blue 4
8 PM Sat 30 30 NW 15 8160 7137 1327 Blue 4
9 PM Sat 30 30 NW 15 8160 7137 1327 Blue 4
10 PM Sat 30 30 N 7 8160 7137 1327 Blue 4
11 PM Sat 29 29 N 7 7894 5811 1 Blue 3
12 Midnight Sun 29 29 N 7 7894 5811 1 Blue 3
1 AM Sun 29 29 N 7 7894 5811 1 Blue 3
2 AM Sun 29 29 N 7 7894 5811 1 Blue 3
3 AM Sun 30 30 N 7 8160 7137 1327 Blue 4
4 AM Sun 30 30 NW 8 8160 7137 1327 Blue 4
5 AM Sun 30 30 NW 8 8160 7137 1327 Blue 4
6 AM Sun 30 30 NW 8 8160 7137 1327 Blue 4
7 AM Sun 30 30 NW 8 8160 7137 1327 Blue 4
8 AM Sun 32 32 NW 8 8462 7840 2030 Blue 6
9 AM Sun 35 36 NW 8 10161 8715 2905 White 10
10 AM Sun 38 40 W 9 10995 10995 5185 White 14
11 AM Sun 40 43 W 9 11616 11616 5806 White 17
12 Noon Sun 41 44 W 9 11822 11822 6012 White 18
1 PM Sun 42 45 W 9 12026 12026 6216 White 19
2 PM Sun 42 44 W 9 11822 11822 6012 White 18
3 PM Sun 41 42 W 9 11410 11410 5600 White 16
4 PM Sun 40 40 W 10 10995 10995 5185 White 14
5 PM Sun 37 37 W 10 10369 9004 3194 White 11
6 PM Sun 35 35 W 10 9951 8424 2614 White 9
7 PM Sun 33 33 W 10 8755 8146 2336 Blue 7
8 PM Sun 32 32 W 10 8462 7840 2030 Blue 6
9 PM Sun 32 32 W 10 8462 7840 2030 Blue 6
10 PM Sun 32 32 W 10 8462 7840 2030 Blue 6
11 PM Sun 32 32 W 10 8462 7840 2030 Blue 6
12 Midnight Mon 31 31 W 10 8280 7400 1590 Blue 5
1 AM Mon 31 31 W 10 8280 7400 1590 Blue 5
2 AM Mon 31 31 W 10 8280 7400 1590 Blue 5
3 AM Mon 31 31 W 10 8280 7400 1590 Blue 5
4 AM Mon 30 30 W 9 8160 7137 1327 Blue 4
5 AM Mon 30 30 W 9 8160 7137 1327 Blue 4
6 AM Mon 29 29 W 9 7894 5811 1 Blue 3
7 AM Mon 29 29 W 9 7894 5811 1 Blue 3
8 AM Mon 29 29 W 9 7894 5811 1 Blue 3
9 AM Mon 30 30 W 9 8160 7137 1327 Blue 4
10 AM Mon 32 33 NW 14 8755 8146 2336 Blue 7
11 AM Mon 33 34 NW 14 9071 8265 2455 Blue 8
12 Noon Mon 34 35 NW 14 9951 8424 2614 White 9
1 PM Mon 35 36 NW 14 10161 8715 2905 White 10
2 PM Mon 35 36 NW 14 10161 8715 2905 White 10
3 PM Mon 34 34 NW 14 9071 8265 2455 Blue 8
4 PM Mon 33 33 N 20 8755 8146 2336 Blue 7
5 PM Mon 32 32 N 20 8462 7840 2030 Blue 6
6 PM Mon 30 30 N 20 8160 7137 1327 Blue 4
7 PM Mon 29 29 N 20 7894 5811 1 Blue 3
8 PM Mon 28 28 N 20 7424 5810 0 Blue 2
9 PM Mon 27 27 N 20 7159 5810 0 Blue 1
10 PM Mon 27 27 NE 10 7159 5810 0 Blue 1
11 PM Mon 27 27 NE 10 7159 5810 0 Blue 1
12 Midnight Tue 26 26 NE 10 5903 5810 0 Blue 0
1 AM Tue 26 26 NE 10 5903 5810 0 Blue 0
2 AM Tue 26 26 NE 10 5903 5810 0 Blue 0
3 AM Tue 26 26 NE 10 5903 5810 0 Blue 0
4 AM Tue 26 26 N 14 5903 5810 0 Blue 0
5 AM Tue 26 26 N 14 5903 5810 0 Blue 0
6 AM Tue 26 26 N 14 5903 5810 0 Blue 0
7 AM Tue 27 27 N 14 7159 5810 0 Blue 1
8 AM Tue 29 29 N 14 7894 5811 1 Blue 3
9 AM Tue 33 34 N 14 9071 8265 2455 Blue 8
10 AM Tue 36 37 N 10 10369 9004 3194 White 11
11 AM Tue 38 40 N 10 10995 10995 5185 White 14
12 Noon Tue 40 43 N 10 11616 11616 5806 White 17
1 PM Tue 41 43 N 10 11616 11616 5806 White 17
2 PM Tue 42 44 N 10 11822 11822 6012 White 18
3 PM Tue 42 43 N 10 11616 11616 5806 White 17
4 PM Tue 41 41 NW 9 11202 11202 5392 White 15
5 PM Tue 39 39 NW 9 10787 10773 4963 White 13
6 PM Tue 36 36 NW 9 10161 8715 2905 White 10
7 PM Tue 33 33 NW 9 8755 8146 2336 Blue 7
8 PM Tue 32 32 NW 9 8462 7840 2030 Blue 6
9 PM Tue 32 32 NW 9 8462 7840 2030 Blue 6
10 PM Tue 31 31 NW 9 8280 7400 1590 Blue 5
11 PM Tue 31 31 NW 9 8280 7400 1590 Blue 5
12 Midnight Wed 31 31 NW 9 8280 7400 1590 Blue 5
1 AM Wed 30 30 NW 9 8160 7137 1327 Blue 4
2 AM Wed 30 30 NW 9 8160 7137 1327 Blue 4
3 AM Wed 31 31 NW 9 8280 7400 1590 Blue 5
4 AM Wed 30 30 NW 10 8160 7137 1327 Blue 4
5 AM Wed 30 30 NW 10 8160 7137 1327 Blue 4
6 AM Wed 30 30 NW 10 8160 7137 1327 Blue 4
7 AM Wed 30 30 NW 10 8160 7137 1327 Blue 4
8 AM Wed 31 31 NW 10 8280 7400 1590 Blue 5
9 AM Wed 33 33 NW 10 8755 8146 2336 Blue 7
10 AM Wed 35 36 W 8 10161 8715 2905 White 10
11 AM Wed 36 37 W 8 10369 9004 3194 White 11
12 Noon Wed 38 40 W 8 10995 10995 5185 White 14
1 PM Wed 39 41 W 8 11202 11202 5392 White 15
2 PM Wed 39 40 W 8 10995 10995 5185 White 14
3 PM Wed 39 40 W 8 10995 10995 5185 White 14
4 PM Wed 38 38 W 9 10579 9944 4134 White 12
5 PM Wed 37 37 W 9 10369 9004 3194 White 11
6 PM Wed 35 35 W 9 9951 8424 2614 White 9
7 PM Wed 34 34 W 9 9071 8265 2455 Blue 8
8 PM Wed 34 34 W 9 9071 8265 2455 Blue 8
9 PM Wed 34 34 W 9 9071 8265 2455 Blue 8
10 PM Wed 34 34 W 9 9071 8265 2455 Blue 8
11 PM Wed 34 34 W 9 9071 8265 2455 Blue 8
12 Midnight Thu 33 33 W 9 8755 8146 2336 Blue 7
1 AM Thu 33 33 W 9 8755 8146 2336 Blue 7
2 AM Thu 33 33 W 9 8755 8146 2336 Blue 7
3 AM Thu 33 33 W 9 8755 8146 2336 Blue 7

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