Detailed Predictions for: Dunlap
Launch Lat, Long, Altitude (f): 36.760, -119.098, 4460
LZ Altitude (f): 1950
Sounding

Station:

KOAK

Date/Time:

12 MAY 2021

Temp/Wind data from:

NOAA Digital Forecast

Site Forecasts
Time
(Local)
High
Temp

Puddle
Temp

Wind
(mph)
Wind
Gust
Thermal
Ceiling

(ft)
Soaring
Ceiling

(ft)
Above
Launch

(ft)
Thermal
Type
Thermal
Index

(F)
12 Midnight Wed 73 68 ENE 6 13 3060 4460 0 Blue 0
1 AM Wed 68 63 ENE 6 13 2566 4460 0 Blue 0
2 AM Wed 64 59 ENE 6 12 2566 4460 0 Blue 0
3 AM Wed 63 58 ENE 5 12 2566 4460 0 Blue 0
4 AM Wed 62 57 ENE 5 11 2566 4460 0 Blue 0
5 AM Wed 62 57 ENE 5 10 2566 4460 0 Blue 0
6 AM Wed 66 61 ESE 4 8 2566 4460 0 Blue 0
7 AM Wed 71 66 SSE 3 5 2566 4460 0 Blue 0
8 AM Wed 75 71 S 2 2 4641 4460 0 Blue 0
9 AM Wed 79 77 SSW 3 3 8548 6056 1596 Blue 6
10 AM Wed 82 82 SW 4 4 11003 9264 4804 Blue 11
11 AM Wed 86 88 SW 4 5 15082 13094 8634 Blue 17
12 Noon Wed 88 91 WSW 5 6 16100 14949 10489 Blue 20
1 PM Wed 90 93 WSW 5 6 16759 15627 11167 Blue 22
2 PM Wed 93 96 WSW 6 6 18604 16614 12154 Blue 25
3 PM Wed 92 93 W 6 7 16759 15627 11167 Blue 22
4 PM Wed 92 91 W 6 7 16100 14949 10489 Blue 20
5 PM Wed 92 89 WNW 6 8 15426 13764 9304 Blue 18
6 PM Wed 91 87 SSW 6 8 14626 12384 7924 Blue 16
7 PM Wed 90 85 ESE 5 9 13315 10797 6337 Blue 14
8 PM Wed 88 83 NE 5 10 11834 9366 4906 Blue 12
9 PM Wed 86 81 NE 5 11 10129 8994 4534 Blue 10
10 PM Wed 84 79 ENE 5 11 9282 8022 3562 Blue 8
11 PM Wed 81 76 ENE 5 11 8174 5775 1315 Blue 5
12 Midnight Thu 76 71 ENE 5 11 4641 4460 0 Blue 0
1 AM Thu 70 65 ENE 5 10 2566 4460 0 Blue 0
2 AM Thu 64 59 E 4 10 2566 4460 0 Blue 0
3 AM Thu 64 59 E 4 10 2566 4460 0 Blue 0
4 AM Thu 63 58 ENE 4 10 2566 4460 0 Blue 0
5 AM Thu 62 57 ENE 4 9 2566 4460 0 Blue 0
6 AM Thu 66 61 SE 3 7 2566 4460 0 Blue 0
7 AM Thu 70 65 S 2 4 2566 4460 0 Blue 0
8 AM Thu 75 71 SW 2 2 4641 4460 0 Blue 0
9 AM Thu 78 76 SW 2 3 8174 5775 1315 Blue 5
10 AM Thu 82 82 SW 3 4 11003 9264 4804 Blue 11
11 AM Thu 86 88 WSW 4 5 15082 13094 8634 Blue 17
12 Noon Thu 88 91 WSW 5 6 16100 14949 10489 Blue 20
1 PM Thu 90 93 WSW 6 6 16759 15627 11167 Blue 22
2 PM Thu 93 96 W 6 7 18604 16614 12154 Blue 25
3 PM Thu 92 93 W 6 8 16759 15627 11167 Blue 22
4 PM Thu 92 91 W 7 8 16100 14949 10489 Blue 20
5 PM Thu 92 89 WNW 7 8 15426 13764 9304 Blue 18
6 PM Thu 91 87 SSW 6 9 14626 12384 7924 Blue 16
7 PM Thu 90 85 ESE 5 9 13315 10797 6337 Blue 14
8 PM Thu 88 83 NNE 4 10 11834 9366 4906 Blue 12
9 PM Thu 86 81 NE 5 11 10129 8994 4534 Blue 10
10 PM Thu 83 78 NE 5 11 9085 6888 2428 Blue 7
11 PM Thu 81 76 ENE 6 12 8174 5775 1315 Blue 5
12 Midnight Fri 75 70 ENE 5 11 3740 4460 0 Blue 0
1 AM Fri 70 65 ENE 5 11 2566 4460 0 Blue 0
2 AM Fri 64 59 E 4 10 2566 4460 0 Blue 0
3 AM Fri 64 59 E 4 9 2566 4460 0 Blue 0
4 AM Fri 63 58 E 4 9 2566 4460 0 Blue 0
5 AM Fri 63 58 E 4 8 2566 4460 0 Blue 0
6 AM Fri 66 61 SE 3 6 2566 4460 0 Blue 0
7 AM Fri 70 65 S 3 5 2566 4460 0 Blue 0
8 AM Fri 73 69 SW 3 3 3401 4460 0 Blue 0
9 AM Fri 77 75 SW 3 4 7020 5491 1031 Blue 4
10 AM Fri 81 81 SW 4 4 10129 8994 4534 Blue 10
11 AM Fri 84 86 SW 4 5 13988 11622 7162 Blue 15
12 Noon Fri 87 90 WSW 5 6 15765 14398 9938 Blue 19
1 PM Fri 89 92 WSW 6 7 16431 15290 10830 Blue 21
2 PM Fri 92 95 W 6 8 18161 16289 11829 Blue 24
3 PM Fri 91 92 W 6 8 16431 15290 10830 Blue 21
4 PM Fri 91 90 W 6 8 15765 14398 9938 Blue 19
5 PM Fri 90 87 WNW 6 8 14626 12384 7924 Blue 16
6 PM Fri 88 84 SSW 6 8 12600 9973 5513 Blue 13
7 PM Fri 87 82 SE 5 9 11003 9264 4804 Blue 11
8 PM Fri 85 80 ENE 5 10 9385 8479 4019 Blue 9
9 PM Fri 82 77 ENE 5 11 8548 6056 1596 Blue 6
10 PM Fri 80 75 E 5 11 7020 5491 1031 Blue 4
11 PM Fri 78 73 E 5 11 5794 4460 0 Blue 2

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 or WeatherAPI.com website.  Puddle temperatures can exceed this temperature. 

Puddle Temp: This estimate is based on the High Temp and the National Weather Service or WeatherAPI.com 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 or WeatherAPI.com website.

Wind Gust: This estimate is taken from the National Weather Service or WeatherAPI.com 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