Detailed Predictions for: Marina Beach
Launch Altitude (f): 60
LZ Altitude (f): 0
Sounding

Station:

KOAK

Date/Time:

26 APR 2018

Temp/Wind data from:

NOAA Digital Forecast

Site Forecasts
Time
(Local)
High
Temp

Puddle
Temp

Wind
(mph)
Thermal
Ceiling

(ft)
Soaring
Ceiling

(ft)
Above
Launch

(ft)
Thermal
Type
Thermal
Index

(F)
5 AM Thu 47 27 N 5 180 180 120 Blue 0
6 AM Thu 47 27 N 5 180 180 120 Blue 0
7 AM Thu 47 27 N 5 180 180 120 Blue 0
8 AM Thu 48 28 W 6 180 180 120 Blue 0
9 AM Thu 50 30 W 6 180 180 120 Blue 0
10 AM Thu 53 33 W 6 180 180 120 Blue 0
11 AM Thu 54 36 W 10 180 180 120 Blue 0
12 Noon Thu 56 38 W 10 180 180 120 Blue 0
1 PM Thu 56 39 W 10 180 180 120 Blue 0
2 PM Thu 57 39 W 13 180 180 120 Blue 0
3 PM Thu 58 40 W 13 180 180 120 Blue 0
4 PM Thu 58 39 W 13 180 180 120 Blue 0
5 PM Thu 58 39 W 13 180 180 120 Blue 0
6 PM Thu 56 36 W 13 180 180 120 Blue 0
7 PM Thu 54 34 W 13 180 180 120 Blue 0
8 PM Thu 53 33 W 10 180 180 120 Blue 0
9 PM Thu 52 32 W 10 180 180 120 Blue 0
10 PM Thu 51 31 W 10 180 180 120 Blue 0
11 PM Thu 50 30 W 7 180 180 120 Blue 0
12 Midnight Fri 50 30 W 7 180 180 120 Blue 0
1 AM Fri 50 30 W 7 180 180 120 Blue 0
2 AM Fri 49 29 SW 5 180 180 120 Blue 0
3 AM Fri 49 29 SW 5 180 180 120 Blue 0
4 AM Fri 48 28 SW 5 180 180 120 Blue 0
5 AM Fri 48 28 S 3 180 180 120 Blue 0
6 AM Fri 47 27 S 3 180 180 120 Blue 0
7 AM Fri 47 27 S 3 180 180 120 Blue 0
8 AM Fri 49 29 N 5 180 180 120 Blue 0
9 AM Fri 51 31 N 5 180 180 120 Blue 0
10 AM Fri 54 35 N 5 180 180 120 Blue 0
11 AM Fri 56 41 NW 7 180 180 120 Blue 0
12 Noon Fri 57 43 NW 7 180 180 120 Blue 0
1 PM Fri 58 44 NW 7 180 180 120 Blue 0
2 PM Fri 59 45 W 13 180 180 120 Blue 0
3 PM Fri 59 44 W 13 180 180 120 Blue 0
4 PM Fri 59 42 W 13 180 180 120 Blue 0
5 PM Fri 59 41 W 14 180 180 120 Blue 0
6 PM Fri 58 38 W 14 180 180 120 Blue 0
7 PM Fri 56 36 W 14 180 180 120 Blue 0
8 PM Fri 54 34 W 14 180 180 120 Blue 0
9 PM Fri 53 33 W 14 180 180 120 Blue 0
10 PM Fri 52 32 W 14 180 180 120 Blue 0
11 PM Fri 51 31 NW 12 180 180 120 Blue 0
12 Midnight Sat 51 31 NW 12 180 180 120 Blue 0
1 AM Sat 50 30 NW 12 180 180 120 Blue 0
2 AM Sat 50 30 NW 12 180 180 120 Blue 0
3 AM Sat 50 30 NW 12 180 180 120 Blue 0
4 AM Sat 49 29 NW 12 180 180 120 Blue 0
5 AM Sat 49 29 NW 10 180 180 120 Blue 0
6 AM Sat 48 28 NW 10 180 180 120 Blue 0
7 AM Sat 48 28 NW 10 180 180 120 Blue 0
8 AM Sat 49 29 NW 10 180 180 120 Blue 0
9 AM Sat 52 32 NW 10 180 180 120 Blue 0
10 AM Sat 54 35 NW 10 180 180 120 Blue 0
11 AM Sat 56 40 W 14 180 180 120 Blue 0
12 Noon Sat 57 41 W 14 180 180 120 Blue 0
1 PM Sat 58 43 W 14 180 180 120 Blue 0
2 PM Sat 58 42 W 14 180 180 120 Blue 0
3 PM Sat 59 42 W 14 180 180 120 Blue 0
4 PM Sat 59 41 W 14 180 180 120 Blue 0
5 PM Sat 59 40 NW 16 180 180 120 Blue 0
6 PM Sat 58 38 NW 16 180 180 120 Blue 0
7 PM Sat 55 35 NW 16 180 180 120 Blue 0
8 PM Sat 53 33 NW 16 180 180 120 Blue 0
9 PM Sat 52 32 NW 16 180 180 120 Blue 0
10 PM Sat 51 31 NW 16 180 180 120 Blue 0
11 PM Sat 51 31 NW 14 180 180 120 Blue 0
12 Midnight Sun 50 30 NW 14 180 180 120 Blue 0
1 AM Sun 50 30 NW 14 180 180 120 Blue 0
2 AM Sun 49 29 NW 14 180 180 120 Blue 0
3 AM Sun 49 29 NW 14 180 180 120 Blue 0
4 AM Sun 48 28 NW 14 180 180 120 Blue 0
5 AM Sun 48 28 NW 12 180 180 120 Blue 0
6 AM Sun 47 27 NW 12 180 180 120 Blue 0
7 AM Sun 47 27 NW 12 180 180 120 Blue 0
8 AM Sun 49 29 NW 12 180 180 120 Blue 0
9 AM Sun 51 32 NW 12 180 180 120 Blue 0
10 AM Sun 54 36 NW 12 180 180 120 Blue 0
11 AM Sun 56 39 NW 10 180 180 120 Blue 0
12 Noon Sun 57 41 NW 10 180 180 120 Blue 0
1 PM Sun 58 42 NW 10 180 180 120 Blue 0
2 PM Sun 58 42 NW 10 180 180 120 Blue 0
3 PM Sun 59 42 NW 10 180 180 120 Blue 0
4 PM Sun 59 41 NW 10 180 180 120 Blue 0
5 PM Sun 59 40 W 15 180 180 120 Blue 0
6 PM Sun 58 38 W 15 180 180 120 Blue 0
7 PM Sun 56 36 W 15 180 180 120 Blue 0
8 PM Sun 54 34 W 15 180 180 120 Blue 0
9 PM Sun 53 33 W 15 180 180 120 Blue 0
10 PM Sun 52 32 W 15 180 180 120 Blue 0
11 PM Sun 52 32 NW 9 180 180 120 Blue 0
12 Midnight Mon 51 31 NW 9 180 180 120 Blue 0
1 AM Mon 51 31 NW 9 180 180 120 Blue 0
2 AM Mon 50 30 NW 9 180 180 120 Blue 0
3 AM Mon 50 30 NW 9 180 180 120 Blue 0
4 AM Mon 49 29 NW 9 180 180 120 Blue 0
5 AM Mon 49 29 NW 10 180 180 120 Blue 0
6 AM Mon 48 28 NW 10 180 180 120 Blue 0
7 AM Mon 48 28 NW 10 180 180 120 Blue 0
8 AM Mon 50 30 NW 10 180 180 120 Blue 0
9 AM Mon 51 32 NW 10 180 180 120 Blue 0
10 AM Mon 54 37 NW 10 180 180 120 Blue 0
11 AM Mon 56 40 NW 9 180 180 120 Blue 0
12 Noon Mon 57 42 NW 9 180 180 120 Blue 0
1 PM Mon 57 42 NW 9 180 180 120 Blue 0
2 PM Mon 58 43 NW 9 180 180 120 Blue 0
3 PM Mon 58 42 NW 9 180 180 120 Blue 0
4 PM Mon 58 41 NW 9 180 180 120 Blue 0
5 PM Mon 58 39 W 20 180 180 120 Blue 0
6 PM Mon 57 37 W 20 180 180 120 Blue 0
7 PM Mon 55 35 W 20 180 180 120 Blue 0
8 PM Mon 53 33 W 20 180 180 120 Blue 0
9 PM Mon 52 32 W 20 180 180 120 Blue 0
10 PM Mon 51 31 W 20 180 180 120 Blue 0
11 PM Mon 51 31 NW 14 180 180 120 Blue 0
12 Midnight Tue 50 30 NW 14 180 180 120 Blue 0
1 AM Tue 50 30 NW 14 180 180 120 Blue 0
2 AM Tue 49 29 NW 14 180 180 120 Blue 0
3 AM Tue 49 29 NW 14 180 180 120 Blue 0
4 AM Tue 48 28 NW 14 180 180 120 Blue 0
5 AM Tue 48 28 W 13 180 180 120 Blue 0
6 AM Tue 47 27 W 13 180 180 120 Blue 0
7 AM Tue 47 27 W 13 180 180 120 Blue 0
8 AM Tue 49 29 W 13 180 180 120 Blue 0
9 AM Tue 51 33 W 13 180 180 120 Blue 0
10 AM Tue 54 37 W 13 180 180 120 Blue 0
11 AM Tue 56 41 NW 7 180 180 120 Blue 0
12 Noon Tue 58 44 NW 7 180 180 120 Blue 0
1 PM Tue 59 45 NW 7 180 180 120 Blue 0
2 PM Tue 60 46 NW 7 180 180 120 Blue 0
3 PM Tue 60 45 NW 7 180 180 120 Blue 0
4 PM Tue 60 43 NW 7 180 180 120 Blue 0
5 PM Tue 60 42 W 12 180 180 120 Blue 0
6 PM Tue 59 39 W 12 180 180 120 Blue 0
7 PM Tue 57 37 W 12 180 180 120 Blue 0
8 PM Tue 55 35 W 12 180 180 120 Blue 0
9 PM Tue 53 33 W 12 180 180 120 Blue 0
10 PM Tue 53 33 W 12 180 180 120 Blue 0
11 PM Tue 52 32 W 1 180 180 120 Blue 0
12 Midnight Wed 52 32 W 1 180 180 120 Blue 0
1 AM Wed 51 31 W 1 180 180 120 Blue 0
2 AM Wed 51 31 W 1 180 180 120 Blue 0
3 AM Wed 50 30 W 1 180 180 120 Blue 0
4 AM Wed 50 30 W 1 180 180 120 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 website.  Puddle temperatures can exceed this temperature. 

Puddle Temp: This estimate is based on the High Temp and the National Weather Service 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 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