Detailed Predictions for: Blackhawk
Launch Lat, Long, Altitude (f): 34.344300, -116.820000, 6280
LZ Altitude (f): 3700
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 45 45 W 5 11 6997 6280 0 Blue 1
1 AM Sat 44 44 W 5 11 6287 6280 0 Blue 0
2 AM Sat 43 43 W 5 11 6073 6280 0 Blue 0
3 AM Sat 43 43 W 5 11 6073 6280 0 Blue 0
4 AM Sat 42 42 W 4 10 6073 6280 0 Blue 0
5 AM Sat 42 42 WNW 4 9 6073 6280 0 Blue 0
6 AM Sat 44 44 NW 4 8 6287 6280 0 Blue 0
7 AM Sat 47 47 NNW 5 7 7693 6286 6 Blue 3
8 AM Sat 49 50 N 5 6 8710 7677 1397 Blue 6
9 AM Sat 51 54 WSW 6 8 10022 9013 2733 Blue 10
10 AM Sat 53 57 SE 8 10 10991 9982 3702 Blue 13
11 AM Sat 55 61 NNE 10 11 14445 11551 5271 White 17
12 Noon Sat 57 64 NNE 11 12 15073 14268 7988 White 20
1 PM Sat 58 65 NNE 11 13 15282 15018 8738 White 21
2 PM Sat 59 66 N 12 14 15490 15490 9210 White 22
3 PM Sat 58 63 SE 13 15 14864 13455 7175 White 19
4 PM Sat 58 61 WSW 13 15 14445 11551 5271 White 17
5 PM Sat 57 58 N 14 16 11745 10199 3919 Blue 14
6 PM Sat 55 55 N 12 16 10223 9339 3059 Blue 11
7 PM Sat 52 52 N 11 17 9372 8352 2072 Blue 8
8 PM Sat 50 50 N 9 17 8710 7677 1397 Blue 6
9 PM Sat 49 49 NNW 8 15 8374 7335 1055 Blue 5
10 PM Sat 48 48 NNW 7 14 8035 6989 709 Blue 4
11 PM Sat 47 47 NNW 6 13 7693 6286 6 Blue 3
12 Midnight Sun 46 46 SW 5 11 7347 6280 0 Blue 2
1 AM Sun 45 45 SE 4 9 6997 6280 0 Blue 1
2 AM Sun 44 44 NNE 3 8 6287 6280 0 Blue 0
3 AM Sun 43 43 SE 4 10 6073 6280 0 Blue 0
4 AM Sun 42 42 WSW 5 12 6073 6280 0 Blue 0
5 AM Sun 42 42 N 6 14 6073 6280 0 Blue 0
6 AM Sun 43 43 WSW 7 13 6073 6280 0 Blue 0
7 AM Sun 45 45 SE 8 13 6997 6280 0 Blue 1
8 AM Sun 46 47 NNE 9 13 7693 6286 6 Blue 3
9 AM Sun 49 52 NNE 10 13 9372 8352 2072 Blue 8
10 AM Sun 52 57 N 11 14 10991 9982 3702 Blue 13
11 AM Sun 54 60 N 12 14 13666 10952 4672 Blue 16
12 Noon Sun 56 64 NNE 15 17 15073 14268 7988 White 20
1 PM Sun 58 66 NNE 17 20 15490 15490 9210 White 22
2 PM Sun 59 66 NNE 20 23 15490 15490 9210 White 22
3 PM Sun 59 64 NNE 19 21 15073 14268 7988 White 20
4 PM Sun 59 62 NNE 17 20 14654 12561 6281 White 18
5 PM Sun 58 59 NNE 16 19 12764 10400 4120 Blue 15
6 PM Sun 56 56 SE 13 17 10499 9662 3382 Blue 12
7 PM Sun 53 53 WSW 9 15 9698 8684 2404 Blue 9
8 PM Sun 50 50 N 6 13 8710 7677 1397 Blue 6
9 PM Sun 50 50 NNW 5 11 8710 7677 1397 Blue 6
10 PM Sun 49 49 NW 4 8 8374 7335 1055 Blue 5
11 PM Sun 48 48 NW 3 6 8035 6989 709 Blue 4
12 Midnight Mon 48 48 WNW 3 6 8035 6989 709 Blue 4
1 AM Mon 48 48 WNW 3 6 8035 6989 709 Blue 4
2 AM Mon 47 47 WNW 3 6 7693 6286 6 Blue 3
3 AM Mon 47 47 W 3 6 7693 6286 6 Blue 3
4 AM Mon 46 46 W 3 6 7347 6280 0 Blue 2
5 AM Mon 46 46 W 2 6 7347 6280 0 Blue 2
6 AM Mon 49 49 W 3 5 8374 7335 1055 Blue 5
7 AM Mon 52 52 WNW 3 5 9372 8352 2072 Blue 8
8 AM Mon 55 56 WNW 3 5 10499 9662 3382 Blue 12
9 AM Mon 58 61 NW 4 6 14445 11551 5271 White 17
10 AM Mon 60 65 NW 5 7 15282 15018 8738 White 21
11 AM Mon 62 68 NNW 6 8 15906 15906 9626 White 24
12 Noon Mon 64 72 NNW 7 8 16734 16734 10454 White 27
1 PM Mon 66 74 NNW 8 9 17146 17146 10866 White 29
2 PM Mon 68 75 NNW 8 10 17353 17353 11073 White 30
3 PM Mon 67 72 NW 8 10 16734 16734 10454 White 27
4 PM Mon 67 70 NW 8 10 16321 16321 10041 White 25
5 PM Mon 66 67 NW 8 10 15699 15699 9419 White 23
6 PM Mon 64 64 WNW 7 11 15073 14268 7988 White 20
7 PM Mon 63 63 W 6 11 14864 13455 7175 White 19
8 PM Mon 61 61 SW 6 12 14445 11551 5271 White 17
9 PM Mon 58 58 WSW 5 12 11745 10199 3919 Blue 14
10 PM Mon 55 55 WSW 5 11 10223 9339 3059 Blue 11
11 PM Mon 53 53 WSW 5 10 9698 8684 2404 Blue 9

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