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

Station:

KVBG

Date/Time:

17 APR 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 Sat 57 57 ENE 4 10 8054 7017 2417 Blue 5
1 AM Sat 55 55 ENE 4 10 7384 4880 280 Blue 3
2 AM Sat 52 52 ENE 5 10 4882 4600 0 Blue 0
3 AM Sat 51 51 ENE 5 10 4228 4600 0 Blue 0
4 AM Sat 51 51 ENE 4 10 4228 4600 0 Blue 0
5 AM Sat 50 50 ENE 4 10 3505 4600 0 Blue 0
6 AM Sat 53 53 ESE 4 8 6503 4600 0 Blue 1
7 AM Sat 55 55 SE 3 5 7384 4880 280 Blue 3
8 AM Sat 58 59 SSE 2 3 8712 7687 3087 Blue 7
9 AM Sat 61 63 S 3 4 9992 8990 4390 Blue 11
10 AM Sat 64 68 SSW 4 4 12532 10345 5745 Blue 16
11 AM Sat 67 73 SW 4 5 14227 13981 9381 White 21
12 Noon Sat 69 76 SW 5 6 14838 14838 10238 White 24
1 PM Sat 72 79 WSW 5 6 15448 15448 10848 White 27
2 PM Sat 73 80 WSW 5 6 15651 15651 11051 White 28
3 PM Sat 73 78 WSW 5 6 15245 15245 10645 White 26
4 PM Sat 73 76 W 4 5 14838 14838 10238 White 24
5 PM Sat 73 74 W 4 5 14430 14430 9830 White 22
6 PM Sat 71 71 SSW 4 6 13816 12285 7685 White 19
7 PM Sat 68 68 ESE 4 8 12532 10345 5745 Blue 16
8 PM Sat 66 66 NE 4 9 10948 9937 5337 Blue 14
9 PM Sat 64 64 NE 5 11 10202 9308 4708 Blue 12
10 PM Sat 62 62 NE 6 13 9676 8669 4069 Blue 10
11 PM Sat 61 61 ENE 7 15 9358 8345 3745 Blue 9
12 Midnight Sun 59 59 ENE 6 14 8712 7687 3087 Blue 7
1 AM Sun 57 57 ENE 6 13 8054 7017 2417 Blue 5
2 AM Sun 55 55 ENE 6 13 7384 4880 280 Blue 3
3 AM Sun 54 54 ENE 6 13 7043 4600 0 Blue 2
4 AM Sun 54 54 ENE 6 14 7043 4600 0 Blue 2
5 AM Sun 54 54 ENE 6 14 7043 4600 0 Blue 2
6 AM Sun 57 57 ENE 5 11 8054 7017 2417 Blue 5
7 AM Sun 59 59 ENE 4 8 8712 7687 3087 Blue 7
8 AM Sun 62 63 E 3 5 9992 8990 4390 Blue 11
9 AM Sun 66 68 SE 3 5 12532 10345 5745 Blue 16
10 AM Sun 70 74 S 4 5 14430 14430 9830 White 22
11 AM Sun 74 80 WSW 5 5 15651 15651 11051 White 28
12 Noon Sun 75 82 WSW 5 6 16054 16054 11454 White 30
1 PM Sun 77 84 W 6 6 16457 16457 11857 White 32
2 PM Sun 79 86 W 6 7 16858 16858 12258 White 34
3 PM Sun 79 84 W 6 7 16457 16457 11857 White 32
4 PM Sun 78 81 WNW 6 7 15852 15852 11252 White 29
5 PM Sun 78 80 WNW 6 7 15651 15651 11051 White 28
6 PM Sun 77 77 SW 6 8 15042 15042 10442 White 25
7 PM Sun 75 75 SE 5 10 14635 14635 10035 White 23
8 PM Sun 74 74 NE 5 11 14430 14430 9830 White 22
9 PM Sun 73 73 NE 6 12 14227 13981 9381 White 21
10 PM Sun 72 72 ENE 6 13 14022 13174 8574 White 20
11 PM Sun 71 71 ENE 7 15 13816 12285 7685 White 19
12 Midnight Mon 66 66 ENE 6 14 10948 9937 5337 Blue 14
1 AM Mon 62 62 ENE 6 13 9676 8669 4069 Blue 10
2 AM Mon 57 57 ENE 6 12 8054 7017 2417 Blue 5
3 AM Mon 57 57 ENE 6 12 8054 7017 2417 Blue 5
4 AM Mon 57 57 ENE 5 12 8054 7017 2417 Blue 5
5 AM Mon 57 57 ENE 5 12 8054 7017 2417 Blue 5
6 AM Mon 59 59 ENE 4 9 8712 7687 3087 Blue 7
7 AM Mon 62 62 E 3 6 9676 8669 4069 Blue 10
8 AM Mon 65 66 E 1 2 10948 9937 5337 Blue 14
9 AM Mon 69 71 SE 2 3 13816 12285 7685 White 19
10 AM Mon 72 76 S 3 4 14838 14838 10238 White 24
11 AM Mon 76 81 SW 4 5 15852 15852 11252 White 29
12 Noon Mon 78 84 WSW 5 5 16457 16457 11857 White 32
1 PM Mon 79 86 WSW 5 6 16858 16858 12258 White 34
2 PM Mon 81 87 WSW 5 6 17059 17059 12459 White 35
3 PM Mon 81 86 W 5 6 16858 16858 12258 White 34
4 PM Mon 81 84 W 6 6 16457 16457 11857 White 32
5 PM Mon 80 82 WNW 6 7 16054 16054 11454 White 30
6 PM Mon 78 78 SSW 5 8 15245 15245 10645 White 26
7 PM Mon 75 75 SE 5 9 14635 14635 10035 White 23
8 PM Mon 73 73 NE 5 10 14227 13981 9381 White 21
9 PM Mon 71 71 ENE 5 12 13816 12285 7685 White 19
10 PM Mon 68 68 ENE 6 13 12532 10345 5745 Blue 16
11 PM Mon 66 66 ENE 6 14 10948 9937 5337 Blue 14

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