Detailed Predictions for: Malibu - Castro Peak
Launch Lat, Long, Altitude (f): 34.08528, -118.7783, 2600
LZ Altitude (f): 0
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 59 49 E 3 4 2539 2600 0 Blue 0
1 AM Sat 59 49 E 3 4 2539 2600 0 Blue 0
2 AM Sat 58 48 E 3 4 2539 2600 0 Blue 0
3 AM Sat 58 48 ENE 2 3 2539 2600 0 Blue 0
4 AM Sat 58 48 ENE 2 3 2539 2600 0 Blue 0
5 AM Sat 57 47 NE 2 2 2539 2600 0 Blue 0
6 AM Sat 60 50 NE 1 2 2539 2600 0 Blue 0
7 AM Sat 62 52 NNE 1 2 2539 2600 0 Blue 0
8 AM Sat 64 55 NNE 1 1 2539 2600 0 Blue 0
9 AM Sat 68 60 SE 1 1 2666 2600 0 Blue 0
10 AM Sat 73 67 WSW 1 1 7590 5973 3373 Blue 4
11 AM Sat 77 73 N 1 1 9493 8492 5892 Blue 10
12 Noon Sat 77 74 NNW 1 1 9800 8805 6205 Blue 11
1 PM Sat 78 76 NW 1 1 10261 9422 6822 Blue 13
2 PM Sat 78 75 NW 1 1 10089 9115 6515 Blue 12
3 PM Sat 76 71 WNW 5 6 8870 7858 5258 Blue 8
4 PM Sat 74 67 WNW 9 11 7590 5973 3373 Blue 4
5 PM Sat 72 64 W 13 16 6138 3386 786 Blue 1
6 PM Sat 70 60 WNW 11 14 2666 2600 0 Blue 0
7 PM Sat 69 59 WNW 8 13 2539 2600 0 Blue 0
8 PM Sat 67 57 NW 6 11 2539 2600 0 Blue 0
9 PM Sat 67 57 SW 6 11 2539 2600 0 Blue 0
10 PM Sat 66 56 ESE 6 12 2539 2600 0 Blue 0
11 PM Sat 66 56 NNE 6 12 2539 2600 0 Blue 0
12 Midnight Sun 66 56 NNE 6 12 2539 2600 0 Blue 0
1 AM Sun 65 55 NNE 6 12 2539 2600 0 Blue 0
2 AM Sun 65 55 NNE 6 12 2539 2600 0 Blue 0
3 AM Sun 64 54 NNE 6 14 2539 2600 0 Blue 0
4 AM Sun 64 54 NNE 8 16 2539 2600 0 Blue 0
5 AM Sun 63 53 NNE 8 18 2539 2600 0 Blue 0
6 AM Sun 65 55 NNE 8 17 2539 2600 0 Blue 0
7 AM Sun 68 58 NNE 8 15 2539 2600 0 Blue 0
8 AM Sun 70 61 NNE 8 13 3404 2600 0 Blue 0
9 AM Sun 72 64 NE 13 17 6138 3386 786 Blue 1
10 AM Sun 75 69 NE 18 22 8236 7212 4612 Blue 6
11 AM Sun 78 74 NE 23 26 9800 8805 6205 Blue 11
12 Noon Sun 80 77 NE 22 25 10609 9727 7127 Blue 14
1 PM Sun 81 79 NE 22 25 11759 10217 7617 Blue 15
2 PM Sun 83 80 NE 21 25 12689 10434 7834 Blue 16
3 PM Sun 82 78 SE 19 22 11014 10029 7429 Blue 14
4 PM Sun 81 75 SSW 16 20 10089 9115 6515 Blue 12
5 PM Sun 79 71 WNW 14 18 8870 7858 5258 Blue 8
6 PM Sun 77 67 WNW 12 17 7590 5973 3373 Blue 4
7 PM Sun 76 66 WNW 9 15 7262 4723 2123 Blue 3
8 PM Sun 74 64 WNW 7 14 6138 3386 786 Blue 1
9 PM Sun 72 62 NW 6 13 4103 2600 0 Blue 0
10 PM Sun 70 60 NNW 6 12 2666 2600 0 Blue 0
11 PM Sun 68 58 NNW 5 11 2539 2600 0 Blue 0
12 Midnight Mon 67 57 SW 5 11 2539 2600 0 Blue 0
1 AM Mon 67 57 ESE 5 11 2539 2600 0 Blue 0
2 AM Mon 66 56 N 5 12 2539 2600 0 Blue 0
3 AM Mon 66 56 N 6 12 2539 2600 0 Blue 0
4 AM Mon 66 56 NNE 6 13 2539 2600 0 Blue 0
5 AM Mon 65 55 NNE 6 13 2539 2600 0 Blue 0
6 AM Mon 68 58 NNE 6 11 2539 2600 0 Blue 0
7 AM Mon 71 61 NNE 5 8 3404 2600 0 Blue 0
8 AM Mon 74 65 NNE 4 6 6932 4071 1471 Blue 2
9 AM Mon 78 70 E 4 4 8554 7537 4937 Blue 7
10 AM Mon 82 76 SE 2 3 10261 9422 6822 Blue 13
11 AM Mon 87 83 SSW 2 2 14155 12390 9790 White 19
12 Noon Mon 85 82 SW 5 6 13955 11456 8856 White 18
1 PM Mon 84 81 SW 8 10 13756 10947 8347 White 17
2 PM Mon 83 79 WSW 12 13 11759 10217 7617 Blue 15
3 PM Mon 81 75 WSW 11 14 10089 9115 6515 Blue 12
4 PM Mon 80 73 WSW 11 15 9493 8492 5892 Blue 10
5 PM Mon 78 69 W 11 15 8236 7212 4612 Blue 6
6 PM Mon 77 67 W 9 14 7590 5973 3373 Blue 4
7 PM Mon 76 66 WNW 7 12 7262 4723 2123 Blue 3
8 PM Mon 75 65 WNW 5 10 6932 4071 1471 Blue 2
9 PM Mon 73 63 SSW 4 8 4768 2663 63 Blue 0
10 PM Mon 72 62 ESE 3 6 4103 2600 0 Blue 0
11 PM Mon 70 60 NNE 2 4 2666 2600 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