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

Station:

KOAK

Date/Time:

25 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 Sun 73 68 E 3 2287 4460 0 Blue 0
6 AM Sun 72 67 E 3 2287 4460 0 Blue 0
7 AM Sun 72 67 E 3 2287 4460 0 Blue 0
8 AM Sun 77 72 SE 2 2287 4460 0 Blue 0
9 AM Sun 81 78 SW 2 2404 4460 0 Blue 0
10 AM Sun 85 84 SW 5 4394 4460 0 Blue 6
11 AM Sun 88 88 SW 6 6428 4994 534 Blue 10
12 Noon Sun 90 92 SW 6 7408 6760 2300 Blue 14
1 PM Sun 91 93 W 6 7516 7022 2562 Blue 15
2 PM Sun 91 93 W 7 7516 7022 2562 Blue 15
3 PM Sun 93 94 W 7 7988 7282 2822 Blue 16
4 PM Sun 93 91 W 7 7300 6373 1913 Blue 13
5 PM Sun 93 90 W 7 7060 5931 1471 Blue 12
6 PM Sun 92 87 W 7 5981 4460 0 Blue 9
7 PM Sun 89 84 W 6 4394 4460 0 Blue 6
8 PM Sun 86 81 NW 6 3599 4460 0 Blue 3
9 PM Sun 80 75 NE 6 2287 4460 0 Blue 0
10 PM Sun 77 72 NE 6 2287 4460 0 Blue 0
11 PM Sun 76 71 NE 5 2287 4460 0 Blue 0
12 Midnight Mon 76 71 NE 5 2287 4460 0 Blue 0
1 AM Mon 75 70 NE 5 2287 4460 0 Blue 0
2 AM Mon 75 70 E 5 2287 4460 0 Blue 0
3 AM Mon 74 69 E 5 2287 4460 0 Blue 0
4 AM Mon 74 69 E 5 2287 4460 0 Blue 0
5 AM Mon 74 69 E 5 2287 4460 0 Blue 0
6 AM Mon 73 68 E 5 2287 4460 0 Blue 0
7 AM Mon 73 68 E 5 2287 4460 0 Blue 0
8 AM Mon 78 73 NE 2 2287 4460 0 Blue 0
9 AM Mon 83 80 W 2 3023 4460 0 Blue 2
10 AM Mon 86 84 SW 3 4394 4460 0 Blue 6
11 AM Mon 89 88 SW 5 6428 4994 534 Blue 10
12 Noon Mon 91 91 SW 5 7300 6373 1913 Blue 13
1 PM Mon 92 92 SW 5 7408 6760 2300 Blue 14
2 PM Mon 92 93 W 6 7516 7022 2562 Blue 15
3 PM Mon 93 93 W 6 7516 7022 2562 Blue 15
4 PM Mon 94 92 W 6 7408 6760 2300 Blue 14
5 PM Mon 94 90 W 6 7060 5931 1471 Blue 12
6 PM Mon 93 88 W 6 6428 4994 534 Blue 10
7 PM Mon 90 85 W 6 5059 4460 0 Blue 7
8 PM Mon 87 82 N 5 3888 4460 0 Blue 4
9 PM Mon 83 78 N 5 2404 4460 0 Blue 0
10 PM Mon 79 74 N 5 2287 4460 0 Blue 0
11 PM Mon 76 71 NE 5 2287 4460 0 Blue 0
12 Midnight Tue 75 70 NE 5 2287 4460 0 Blue 0
1 AM Tue 75 70 NE 5 2287 4460 0 Blue 0
2 AM Tue 76 71 E 5 2287 4460 0 Blue 0
3 AM Tue 76 71 E 5 2287 4460 0 Blue 0
4 AM Tue 75 70 E 5 2287 4460 0 Blue 0
5 AM Tue 75 70 NE 6 2287 4460 0 Blue 0
6 AM Tue 75 70 NE 6 2287 4460 0 Blue 0
7 AM Tue 76 71 NE 6 2287 4460 0 Blue 0
8 AM Tue 78 73 E 3 2287 4460 0 Blue 0
9 AM Tue 82 79 E 3 2872 4460 0 Blue 1
10 AM Tue 86 85 E 3 5059 4460 0 Blue 7
11 AM Tue 90 89 SW 5 6796 5480 1020 Blue 11
12 Noon Tue 92 92 SW 5 7408 6760 2300 Blue 14
1 PM Tue 93 93 SW 5 7516 7022 2562 Blue 15
2 PM Tue 94 94 W 6 7988 7282 2822 Blue 16
3 PM Tue 95 94 W 6 7988 7282 2822 Blue 16
4 PM Tue 95 93 W 6 7516 7022 2562 Blue 15
5 PM Tue 95 92 W 6 7408 6760 2300 Blue 14
6 PM Tue 94 89 W 6 6796 5480 1020 Blue 11
7 PM Tue 91 86 W 6 5525 4460 0 Blue 8
8 PM Tue 88 83 W 5 4175 4460 0 Blue 5
9 PM Tue 84 79 W 5 2872 4460 0 Blue 1
10 PM Tue 80 75 W 5 2287 4460 0 Blue 0
11 PM Tue 77 72 E 3 2287 4460 0 Blue 0
12 Midnight Wed 76 71 E 3 2287 4460 0 Blue 0
1 AM Wed 76 71 E 3 2287 4460 0 Blue 0
2 AM Wed 76 71 E 5 2287 4460 0 Blue 0
3 AM Wed 75 70 E 5 2287 4460 0 Blue 0
4 AM Wed 75 70 E 5 2287 4460 0 Blue 0
5 AM Wed 75 70 E 5 2287 4460 0 Blue 0
6 AM Wed 75 70 E 5 2287 4460 0 Blue 0
7 AM Wed 76 71 E 5 2287 4460 0 Blue 0
8 AM Wed 78 73 E 3 2287 4460 0 Blue 0
9 AM Wed 81 78 E 3 2404 4460 0 Blue 0
10 AM Wed 85 84 E 3 4394 4460 0 Blue 6
11 AM Wed 89 89 SW 6 6796 5480 1020 Blue 11
12 Noon Wed 91 92 SW 6 7408 6760 2300 Blue 14
1 PM Wed 92 94 SW 6 7988 7282 2822 Blue 16
2 PM Wed 93 94 SW 7 7988 7282 2822 Blue 16
3 PM Wed 94 94 SW 7 7988 7282 2822 Blue 16
4 PM Wed 95 94 SW 7 7988 7282 2822 Blue 16
5 PM Wed 94 91 W 6 7300 6373 1913 Blue 13
6 PM Wed 92 88 W 6 6428 4994 534 Blue 10
7 PM Wed 89 84 W 6 4394 4460 0 Blue 6
8 PM Wed 86 81 W 5 3599 4460 0 Blue 3
9 PM Wed 82 77 W 5 2287 4460 0 Blue 0
10 PM Wed 77 72 W 5 2287 4460 0 Blue 0
11 PM Wed 74 69 NE 5 2287 4460 0 Blue 0
12 Midnight Thu 73 68 NE 5 2287 4460 0 Blue 0
1 AM Thu 74 69 NE 5 2287 4460 0 Blue 0
2 AM Thu 74 69 E 5 2287 4460 0 Blue 0
3 AM Thu 73 68 E 5 2287 4460 0 Blue 0
4 AM Thu 72 67 E 5 2287 4460 0 Blue 0
5 AM Thu 72 67 E 5 2287 4460 0 Blue 0
6 AM Thu 72 67 E 5 2287 4460 0 Blue 0
7 AM Thu 73 68 E 5 2287 4460 0 Blue 0
8 AM Thu 75 70 SW 2 2287 4460 0 Blue 0
9 AM Thu 78 75 SW 2 2287 4460 0 Blue 0
10 AM Thu 82 81 SW 2 3599 4460 0 Blue 3
11 AM Thu 86 87 SW 6 5981 4460 0 Blue 9
12 Noon Thu 88 90 SW 6 7060 5931 1471 Blue 12
1 PM Thu 89 91 SW 6 7300 6373 1913 Blue 13
2 PM Thu 90 92 W 6 7408 6760 2300 Blue 14
3 PM Thu 91 92 W 6 7408 6760 2300 Blue 14
4 PM Thu 92 91 W 6 7300 6373 1913 Blue 13
5 PM Thu 91 88 W 6 6428 4994 534 Blue 10
6 PM Thu 89 85 W 6 5059 4460 0 Blue 7
7 PM Thu 86 81 W 6 3599 4460 0 Blue 3
8 PM Thu 83 78 W 5 2404 4460 0 Blue 0
9 PM Thu 79 74 W 5 2287 4460 0 Blue 0
10 PM Thu 76 71 W 5 2287 4460 0 Blue 0
11 PM Thu 73 68 NE 5 2287 4460 0 Blue 0
12 Midnight Fri 72 67 NE 5 2287 4460 0 Blue 0
1 AM Fri 72 67 NE 5 2287 4460 0 Blue 0
2 AM Fri 72 67 NE 5 2287 4460 0 Blue 0
3 AM Fri 71 66 NE 5 2287 4460 0 Blue 0
4 AM Fri 71 66 NE 5 2287 4460 0 Blue 0
5 AM Fri 71 66 E 5 2287 4460 0 Blue 0
6 AM Fri 71 66 E 5 2287 4460 0 Blue 0
7 AM Fri 72 67 E 5 2287 4460 0 Blue 0
8 AM Fri 74 69 SW 2 2287 4460 0 Blue 0
9 AM Fri 77 74 SW 2 2287 4460 0 Blue 0
10 AM Fri 81 80 SW 2 3023 4460 0 Blue 2
11 AM Fri 85 85 SW 6 5059 4460 0 Blue 7
12 Noon Fri 87 89 SW 6 6796 5480 1020 Blue 11
1 PM Fri 88 90 SW 6 7060 5931 1471 Blue 12
2 PM Fri 89 91 W 6 7300 6373 1913 Blue 13
3 PM Fri 90 90 W 6 7060 5931 1471 Blue 12
4 PM Fri 90 89 W 6 6796 5480 1020 Blue 11
5 PM Fri 90 87 W 7 5981 4460 0 Blue 9
6 PM Fri 89 85 W 7 5059 4460 0 Blue 7
7 PM Fri 86 81 W 7 3599 4460 0 Blue 3
8 PM Fri 83 78 W 5 2404 4460 0 Blue 0
9 PM Fri 79 74 W 5 2287 4460 0 Blue 0
10 PM Fri 75 70 W 5 2287 4460 0 Blue 0
11 PM Fri 72 67 N 5 2287 4460 0 Blue 0
12 Midnight Sat 71 66 N 5 2287 4460 0 Blue 0
1 AM Sat 71 66 N 5 2287 4460 0 Blue 0
2 AM Sat 72 67 NE 5 2287 4460 0 Blue 0
3 AM Sat 72 67 NE 5 2287 4460 0 Blue 0
4 AM Sat 71 66 NE 5 2287 4460 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