Detailed Predictions for: Dunlap
Launch Lat, Long, Altitude (f): 36.765278, -119.098444, 4600
LZ Altitude (f): 2200
Sounding

Station:

KVBG

Date/Time:

16 SEP 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 Thu 70 70 ENE 6 12 5978 4794 194 Blue 3
1 AM Thu 69 69 ENE 5 11 5584 4690 90 Blue 2
2 AM Thu 68 68 E 4 10 5184 4600 0 Blue 1
3 AM Thu 67 67 E 4 9 4794 4600 0 Blue 0
4 AM Thu 66 66 E 4 8 4691 4600 0 Blue 0
5 AM Thu 65 65 E 4 8 4587 4600 0 Blue 0
6 AM Thu 64 64 E 4 8 4483 4600 0 Blue 0
7 AM Thu 64 64 E 3 7 4483 4600 0 Blue 0
8 AM Thu 72 72 SE 1 2 6750 5572 972 Blue 5
9 AM Thu 77 78 SW 3 4 8954 7835 3235 Blue 11
10 AM Thu 81 84 SW 4 5 11926 9942 5342 Blue 17
11 AM Thu 85 90 SW 5 5 15390 13591 8991 Blue 23
12 Noon Thu 89 95 SW 5 6 17372 16202 11602 White 28
1 PM Thu 91 97 WSW 6 7 17783 17144 12544 White 30
2 PM Thu 92 98 WSW 6 7 17989 17598 12998 White 31
3 PM Thu 93 98 W 6 8 17989 17598 12998 White 31
4 PM Thu 93 96 W 6 7 17579 16679 12079 White 29
5 PM Thu 91 92 W 6 7 16392 14686 10086 Blue 25
6 PM Thu 88 88 W 6 8 14323 12406 7806 Blue 21
7 PM Thu 77 77 NW 3 6 8597 7469 2869 Blue 10
8 PM Thu 74 74 NE 5 12 7503 6346 1746 Blue 7
9 PM Thu 72 72 ENE 7 15 6750 5572 972 Blue 5
10 PM Thu 70 70 ENE 6 13 5978 4794 194 Blue 3
11 PM Thu 69 69 E 5 12 5584 4690 90 Blue 2
12 Midnight Fri 67 67 ENE 4 10 4794 4600 0 Blue 0
1 AM Fri 66 66 ENE 4 9 4691 4600 0 Blue 0
2 AM Fri 65 65 ENE 4 9 4587 4600 0 Blue 0
3 AM Fri 65 65 ENE 4 8 4587 4600 0 Blue 0
4 AM Fri 65 65 E 4 8 4587 4600 0 Blue 0
5 AM Fri 64 64 E 4 8 4483 4600 0 Blue 0
6 AM Fri 64 64 E 4 9 4483 4600 0 Blue 0
7 AM Fri 64 64 E 3 8 4483 4600 0 Blue 0
8 AM Fri 71 71 S 0 0 6367 5177 577 Blue 4
9 AM Fri 76 77 WSW 3 3 8597 7469 2869 Blue 10
10 AM Fri 81 84 SW 4 4 11926 9942 5342 Blue 17
11 AM Fri 86 91 SW 5 5 15898 14148 9548 Blue 24
12 Noon Fri 89 95 SW 6 6 17372 16202 11602 White 28
1 PM Fri 91 97 WSW 5 6 17783 17144 12544 White 30
2 PM Fri 93 99 WSW 6 7 18194 18042 13442 White 32
3 PM Fri 93 98 WSW 6 6 17989 17598 12998 White 31
4 PM Fri 93 96 WSW 5 6 17579 16679 12079 White 29
5 PM Fri 91 92 WSW 5 5 16392 14686 10086 Blue 25
6 PM Fri 89 89 W 4 6 14866 13011 8411 Blue 22
7 PM Fri 77 77 NNW 1 3 8597 7469 2869 Blue 10
8 PM Fri 74 74 ENE 5 12 7503 6346 1746 Blue 7
9 PM Fri 72 72 ENE 6 13 6750 5572 972 Blue 5
10 PM Fri 70 70 E 5 11 5978 4794 194 Blue 3
11 PM Fri 68 68 E 4 9 5184 4600 0 Blue 1
12 Midnight Sat 67 67 E 4 9 4794 4600 0 Blue 0
1 AM Sat 66 66 E 4 8 4691 4600 0 Blue 0
2 AM Sat 64 64 E 4 8 4483 4600 0 Blue 0
3 AM Sat 64 64 E 3 8 4483 4600 0 Blue 0
4 AM Sat 64 64 ENE 3 6 4483 4600 0 Blue 0
5 AM Sat 63 63 ENE 3 7 4379 4600 0 Blue 0
6 AM Sat 63 63 ENE 3 8 4379 4600 0 Blue 0
7 AM Sat 63 63 ENE 3 7 4379 4600 0 Blue 0
8 AM Sat 70 70 SSE 1 1 5978 4794 194 Blue 3
9 AM Sat 75 76 SW 4 4 8237 7100 2500 Blue 9
10 AM Sat 79 82 SW 4 5 10536 9255 4655 Blue 15
11 AM Sat 83 88 SW 5 5 14323 12406 7806 Blue 21
12 Noon Sat 86 92 SW 5 6 16392 14686 10086 Blue 25
1 PM Sat 89 95 SW 5 6 17372 16202 11602 White 28
2 PM Sat 90 96 SW 6 8 17579 16679 12079 White 29
3 PM Sat 90 95 WSW 7 8 17372 16202 11602 White 28
4 PM Sat 90 93 W 7 8 16873 15207 10607 Blue 26
5 PM Sat 88 89 W 6 8 14866 13011 8411 Blue 22
6 PM Sat 85 85 WNW 6 8 12566 10399 5799 Blue 18
7 PM Sat 74 74 NNW 3 6 7503 6346 1746 Blue 7
8 PM Sat 71 71 NE 6 12 6367 5177 577 Blue 4
9 PM Sat 68 68 ENE 6 13 5184 4600 0 Blue 1
10 PM Sat 66 66 ENE 5 11 4691 4600 0 Blue 0
11 PM Sat 65 65 E 5 12 4587 4600 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 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