Detailed Predictions for: Marina Beach
Launch Lat, Long, Altitude (f): 36.600, -121.89, 60
LZ Altitude (f): 0
Sounding

Station:

KOAK

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 53 33 NW 0 1 0 60 0 Blue 0
1 AM Thu 52 32 WSW 0 0 0 60 0 Blue 0
2 AM Thu 52 32 WNW 0 1 0 60 0 Blue 0
3 AM Thu 52 32 ESE 0 0 0 60 0 Blue 0
4 AM Thu 52 32 WNW 0 1 0 60 0 Blue 0
5 AM Thu 51 31 WSW 0 1 0 60 0 Blue 0
6 AM Thu 52 32 W 1 3 0 60 0 Blue 0
7 AM Thu 51 31 WSW 1 3 0 60 0 Blue 0
8 AM Thu 56 36 W 2 3 0 60 0 Blue 0
9 AM Thu 60 41 W 2 3 0 60 0 Blue 0
10 AM Thu 63 46 W 3 3 0 60 0 Blue 0
11 AM Thu 66 50 W 5 6 0 60 0 Blue 0
12 Noon Thu 66 52 W 6 7 0 60 0 Blue 0
1 PM Thu 66 52 W 8 9 0 60 0 Blue 0
2 PM Thu 70 56 W 8 9 0 60 0 Blue 0
3 PM Thu 70 55 W 9 10 0 60 0 Blue 0
4 PM Thu 68 51 W 9 11 0 60 0 Blue 0
5 PM Thu 62 44 W 7 8 0 60 0 Blue 0
6 PM Thu 64 44 W 4 5 0 60 0 Blue 0
7 PM Thu 57 37 WNW 6 8 0 60 0 Blue 0
8 PM Thu 52 32 W 3 7 0 60 0 Blue 0
9 PM Thu 52 32 WNW 4 8 0 60 0 Blue 0
10 PM Thu 52 32 W 1 2 0 60 0 Blue 0
11 PM Thu 52 32 SW 1 2 0 60 0 Blue 0
12 Midnight Fri 52 32 WNW 4 9 0 60 0 Blue 0
1 AM Fri 51 31 W 2 4 0 60 0 Blue 0
2 AM Fri 52 32 NW 2 4 0 60 0 Blue 0
3 AM Fri 51 31 NW 2 5 0 60 0 Blue 0
4 AM Fri 52 32 E 0 1 0 60 0 Blue 0
5 AM Fri 53 33 SE 3 7 0 60 0 Blue 0
6 AM Fri 52 32 WNW 4 8 0 60 0 Blue 0
7 AM Fri 50 30 W 2 5 0 60 0 Blue 0
8 AM Fri 56 36 SW 1 1 0 60 0 Blue 0
9 AM Fri 61 42 W 1 1 0 60 0 Blue 0
10 AM Fri 64 47 WNW 4 5 0 60 0 Blue 0
11 AM Fri 67 51 W 5 6 0 60 0 Blue 0
12 Noon Fri 67 53 W 6 8 0 60 0 Blue 0
1 PM Fri 66 52 W 7 8 0 60 0 Blue 0
2 PM Fri 66 52 W 7 8 0 60 0 Blue 0
3 PM Fri 66 51 W 7 8 0 60 0 Blue 0
4 PM Fri 65 48 W 7 8 0 60 0 Blue 0
5 PM Fri 65 47 W 6 7 0 60 0 Blue 0
6 PM Fri 64 44 W 6 7 0 60 0 Blue 0
7 PM Fri 60 40 WSW 4 5 0 60 0 Blue 0
8 PM Fri 54 34 WSW 3 6 0 60 0 Blue 0
9 PM Fri 53 33 SW 2 6 0 60 0 Blue 0
10 PM Fri 53 33 SW 2 4 0 60 0 Blue 0
11 PM Fri 53 33 S 2 4 0 60 0 Blue 0
12 Midnight Sat 53 33 SSE 1 3 0 60 0 Blue 0
1 AM Sat 52 32 S 1 2 0 60 0 Blue 0
2 AM Sat 52 32 SE 2 4 0 60 0 Blue 0
3 AM Sat 52 32 SE 2 4 0 60 0 Blue 0
4 AM Sat 52 32 SE 2 5 0 60 0 Blue 0
5 AM Sat 52 32 ESE 2 4 0 60 0 Blue 0
6 AM Sat 52 32 SE 1 2 0 60 0 Blue 0
7 AM Sat 51 31 SSE 0 1 0 60 0 Blue 0
8 AM Sat 57 37 SE 0 0 0 60 0 Blue 0
9 AM Sat 61 42 SE 0 1 0 60 0 Blue 0
10 AM Sat 65 48 WNW 2 3 0 60 0 Blue 0
11 AM Sat 68 52 WNW 4 5 0 60 0 Blue 0
12 Noon Sat 68 54 WNW 6 7 0 60 0 Blue 0
1 PM Sat 68 54 WNW 6 7 0 60 0 Blue 0
2 PM Sat 69 55 W 6 7 0 60 0 Blue 0
3 PM Sat 69 54 W 6 7 0 60 0 Blue 0
4 PM Sat 71 54 WNW 9 10 0 60 0 Blue 0
5 PM Sat 64 45 W 7 8 0 60 0 Blue 0
6 PM Sat 63 43 WNW 6 6 0 60 0 Blue 0
7 PM Sat 59 39 W 4 6 0 60 0 Blue 0
8 PM Sat 56 36 WSW 2 5 0 60 0 Blue 0
9 PM Sat 56 36 SW 2 3 0 60 0 Blue 0
10 PM Sat 56 36 WNW 2 4 0 60 0 Blue 0
11 PM Sat 56 36 NW 3 5 0 60 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