Detailed Predictions for: Dunlap
Launch Altitude (f): 4460
LZ Altitude (f): 1950
Sounding

Station:

KOAK

Date/Time:

23 SEP 2017

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 Sat 45 40 E 5 2287 4460 0 Blue 0
6 AM Sat 44 39 E 5 2287 4460 0 Blue 0
7 AM Sat 44 39 E 5 2287 4460 0 Blue 0
8 AM Sat 46 41 E 5 2287 4460 0 Blue 0
9 AM Sat 51 47 E 5 2287 4460 0 Blue 0
10 AM Sat 56 54 E 5 2287 4460 0 Blue 0
11 AM Sat 61 60 SW 7 5832 4460 0 Blue 6
12 Noon Sat 65 65 SW 7 8480 6786 2326 White 11
1 PM Sat 68 69 SW 7 9317 9061 4601 White 15
2 PM Sat 70 70 SW 7 9525 9525 5065 White 16
3 PM Sat 71 70 SW 7 9525 9525 5065 White 16
4 PM Sat 72 69 SW 7 9317 9061 4601 White 15
5 PM Sat 71 67 SE 3 8900 7930 3470 White 13
6 PM Sat 69 64 SE 3 8060 6200 1740 Blue 10
7 PM Sat 65 60 SE 3 5832 4460 0 Blue 6
8 PM Sat 62 57 SE 3 3902 4460 0 Blue 3
9 PM Sat 59 54 SE 3 2287 4460 0 Blue 0
10 PM Sat 57 52 SE 3 2287 4460 0 Blue 0
11 PM Sat 55 50 E 7 2287 4460 0 Blue 0
12 Midnight Sun 54 49 E 7 2287 4460 0 Blue 0
1 AM Sun 53 48 E 7 2287 4460 0 Blue 0
2 AM Sun 52 47 E 7 2287 4460 0 Blue 0
3 AM Sun 51 46 E 7 2287 4460 0 Blue 0
4 AM Sun 50 45 E 7 2287 4460 0 Blue 0
5 AM Sun 49 44 E 6 2287 4460 0 Blue 0
6 AM Sun 48 43 E 6 2287 4460 0 Blue 0
7 AM Sun 49 44 E 6 2287 4460 0 Blue 0
8 AM Sun 51 46 E 6 2287 4460 0 Blue 0
9 AM Sun 57 53 E 6 2287 4460 0 Blue 0
10 AM Sun 63 61 E 6 6252 4460 0 Blue 7
11 AM Sun 69 68 SW 5 9109 8601 4141 White 14
12 Noon Sun 72 72 SW 5 9962 9962 5502 White 18
1 PM Sun 74 75 SW 5 10577 10577 6117 White 21
2 PM Sun 75 75 W 6 10577 10577 6117 White 21
3 PM Sun 76 75 W 6 10577 10577 6117 White 21
4 PM Sun 77 74 W 6 10372 10372 5912 White 20
5 PM Sun 76 72 NW 2 9962 9962 5502 White 18
6 PM Sun 72 67 NW 2 8900 7930 3470 White 13
7 PM Sun 67 62 NW 2 6847 4460 0 Blue 8
8 PM Sun 62 57 NW 2 3902 4460 0 Blue 3
9 PM Sun 58 53 NW 2 2287 4460 0 Blue 0
10 PM Sun 56 51 NW 2 2287 4460 0 Blue 0
11 PM Sun 55 50 NE 7 2287 4460 0 Blue 0
12 Midnight Mon 54 49 NE 7 2287 4460 0 Blue 0
1 AM Mon 54 49 NE 7 2287 4460 0 Blue 0
2 AM Mon 53 48 NE 7 2287 4460 0 Blue 0
3 AM Mon 52 47 NE 7 2287 4460 0 Blue 0
4 AM Mon 51 46 NE 7 2287 4460 0 Blue 0
5 AM Mon 50 45 E 7 2287 4460 0 Blue 0
6 AM Mon 49 44 E 7 2287 4460 0 Blue 0
7 AM Mon 50 45 E 7 2287 4460 0 Blue 0
8 AM Mon 52 47 E 7 2287 4460 0 Blue 0
9 AM Mon 58 54 E 7 2287 4460 0 Blue 0
10 AM Mon 64 62 E 7 6847 4460 0 Blue 8
11 AM Mon 70 69 SW 5 9317 9061 4601 White 15
12 Noon Mon 74 74 SW 5 10372 10372 5912 White 20
1 PM Mon 76 76 SW 5 10780 10780 6320 White 22
2 PM Mon 77 77 SW 5 10983 10983 6523 White 23
3 PM Mon 79 78 SW 5 11186 11186 6726 White 24
4 PM Mon 80 77 SW 5 10983 10983 6523 White 23
5 PM Mon 79 75 NW 5 10577 10577 6117 White 21
6 PM Mon 74 69 NW 5 9317 9061 4601 White 15
7 PM Mon 69 64 NW 5 8060 6200 1740 Blue 10
8 PM Mon 63 58 NW 5 4145 4460 0 Blue 4
9 PM Mon 60 55 NW 5 2657 4460 0 Blue 1
10 PM Mon 59 54 NW 5 2287 4460 0 Blue 0
11 PM Mon 59 54 NE 6 2287 4460 0 Blue 0
12 Midnight Tue 58 53 NE 6 2287 4460 0 Blue 0
1 AM Tue 57 52 NE 6 2287 4460 0 Blue 0
2 AM Tue 56 51 NE 6 2287 4460 0 Blue 0
3 AM Tue 55 50 NE 6 2287 4460 0 Blue 0
4 AM Tue 54 49 NE 6 2287 4460 0 Blue 0
5 AM Tue 53 48 NE 6 2287 4460 0 Blue 0
6 AM Tue 52 47 NE 6 2287 4460 0 Blue 0
7 AM Tue 53 48 NE 6 2287 4460 0 Blue 0
8 AM Tue 56 51 NE 6 2287 4460 0 Blue 0
9 AM Tue 61 57 NE 6 3902 4460 0 Blue 3
10 AM Tue 69 67 NE 6 8900 7930 3470 White 13
11 AM Tue 75 74 SW 3 10372 10372 5912 White 20
12 Noon Tue 79 79 SW 3 11388 11388 6928 White 25
1 PM Tue 81 82 SW 3 11989 11989 7529 White 28
2 PM Tue 83 83 SW 3 12189 12189 7729 White 29
3 PM Tue 84 83 SW 3 12189 12189 7729 White 29
4 PM Tue 84 81 SW 3 11789 11789 7329 White 27
5 PM Tue 82 78 NW 3 11186 11186 6726 White 24
6 PM Tue 78 73 NW 3 10168 10168 5708 White 19
7 PM Tue 72 67 NW 3 8900 7930 3470 White 13
8 PM Tue 67 62 NW 3 6847 4460 0 Blue 8
9 PM Tue 64 59 NW 3 4403 4460 0 Blue 5
10 PM Tue 61 56 NW 3 3262 4460 0 Blue 2
11 PM Tue 60 55 NE 5 2657 4460 0 Blue 1
12 Midnight Wed 59 54 NE 5 2287 4460 0 Blue 0
1 AM Wed 58 53 NE 5 2287 4460 0 Blue 0
2 AM Wed 57 52 NE 5 2287 4460 0 Blue 0
3 AM Wed 56 51 NE 5 2287 4460 0 Blue 0
4 AM Wed 56 51 NE 5 2287 4460 0 Blue 0
5 AM Wed 55 50 NE 6 2287 4460 0 Blue 0
6 AM Wed 54 49 NE 6 2287 4460 0 Blue 0
7 AM Wed 54 49 NE 6 2287 4460 0 Blue 0
8 AM Wed 56 51 NE 6 2287 4460 0 Blue 0
9 AM Wed 62 58 NE 6 4145 4460 0 Blue 4
10 AM Wed 70 68 NE 6 9109 8601 4141 White 14
11 AM Wed 77 76 SW 3 10780 10780 6320 White 22
12 Noon Wed 81 81 SW 3 11789 11789 7329 White 27
1 PM Wed 83 84 SW 3 12389 12389 7929 White 30
2 PM Wed 84 84 SW 3 12389 12389 7929 White 30
3 PM Wed 86 85 SW 3 12588 12588 8128 White 31
4 PM Wed 86 83 SW 3 12189 12189 7729 White 29
5 PM Wed 84 80 NW 5 11589 11589 7129 White 26
6 PM Wed 80 75 NW 5 10577 10577 6117 White 21
7 PM Wed 74 69 NW 5 9317 9061 4601 White 15
8 PM Wed 69 64 NW 5 8060 6200 1740 Blue 10
9 PM Wed 66 61 NW 5 6252 4460 0 Blue 7
10 PM Wed 64 59 NW 5 4403 4460 0 Blue 5
11 PM Wed 63 58 E 6 4145 4460 0 Blue 4
12 Midnight Thu 62 57 E 6 3902 4460 0 Blue 3
1 AM Thu 61 56 E 6 3262 4460 0 Blue 2
2 AM Thu 60 55 E 6 2657 4460 0 Blue 1
3 AM Thu 59 54 E 6 2287 4460 0 Blue 0
4 AM Thu 58 53 E 6 2287 4460 0 Blue 0
5 AM Thu 57 52 NE 6 2287 4460 0 Blue 0
6 AM Thu 56 51 NE 6 2287 4460 0 Blue 0
7 AM Thu 56 51 NE 6 2287 4460 0 Blue 0
8 AM Thu 58 53 NE 6 2287 4460 0 Blue 0
9 AM Thu 64 60 NE 6 5832 4460 0 Blue 6
10 AM Thu 70 68 NE 6 9109 8601 4141 White 14
11 AM Thu 76 75 SW 3 10577 10577 6117 White 21
12 Noon Thu 81 81 SW 3 11789 11789 7329 White 27
1 PM Thu 83 83 SW 3 12189 12189 7729 White 29
2 PM Thu 85 85 SW 3 12588 12588 8128 White 31
3 PM Thu 87 86 SW 3 12788 12788 8328 White 32
4 PM Thu 87 84 SW 3 12389 12389 7929 White 30
5 PM Thu 85 81 SW 5 11789 11789 7329 White 27
6 PM Thu 81 76 SW 5 10780 10780 6320 White 22
7 PM Thu 76 71 SW 5 9733 9733 5273 White 17
8 PM Thu 72 67 SW 5 8900 7930 3470 White 13
9 PM Thu 70 65 SW 5 8480 6786 2326 White 11
10 PM Thu 69 64 SW 5 8060 6200 1740 Blue 10
11 PM Thu 68 63 NE 5 7339 5695 1235 Blue 9
12 Midnight Fri 66 61 NE 5 6252 4460 0 Blue 7
1 AM Fri 64 59 NE 5 4403 4460 0 Blue 5
2 AM Fri 62 57 NE 5 3902 4460 0 Blue 3
3 AM Fri 60 55 NE 5 2657 4460 0 Blue 1
4 AM Fri 60 55 NE 5 2657 4460 0 Blue 1

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