Detailed Predictions for: Ed Levin
Launch Altitude (f): 2150
LZ Altitude (f): 400
Sounding

Station:

KOAK

Date/Time:

25 APR 2019

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 58 58 S 5 1801 2150 0 Blue 0
6 AM Thu 57 57 S 5 1801 2150 0 Blue 0
7 AM Thu 57 57 S 5 1801 2150 0 Blue 0
8 AM Thu 60 60 S 6 1801 2150 0 Blue 0
9 AM Thu 65 67 S 6 1801 2150 0 Blue 0
10 AM Thu 66 70 S 6 1904 2150 0 Blue 0
11 AM Thu 68 74 SW 7 2337 2150 0 Blue 1
12 Noon Thu 72 79 SW 7 2915 2555 405 Blue 5
1 PM Thu 73 80 SW 7 3044 2653 503 Blue 6
2 PM Thu 75 82 W 8 3416 2910 760 Blue 8
3 PM Thu 76 81 W 8 3205 2782 632 Blue 7
4 PM Thu 76 80 W 8 3044 2653 503 Blue 6
5 PM Thu 75 77 W 8 2657 2335 185 Blue 4
6 PM Thu 74 74 W 8 2337 2150 0 Blue 1
7 PM Thu 71 71 W 8 2012 2150 0 Blue 0
8 PM Thu 68 68 W 5 1801 2150 0 Blue 0
9 PM Thu 64 64 W 5 1801 2150 0 Blue 0
10 PM Thu 62 62 W 5 1801 2150 0 Blue 0
11 PM Thu 60 60 SW 3 1801 2150 0 Blue 0
12 Midnight Fri 59 59 SW 3 1801 2150 0 Blue 0
1 AM Fri 58 58 SW 3 1801 2150 0 Blue 0
2 AM Fri 57 57 S 3 1801 2150 0 Blue 0
3 AM Fri 56 56 S 3 1801 2150 0 Blue 0
4 AM Fri 56 56 S 3 1801 2150 0 Blue 0
5 AM Fri 55 55 S 3 1801 2150 0 Blue 0
6 AM Fri 55 55 S 3 1801 2150 0 Blue 0
7 AM Fri 55 55 S 3 1801 2150 0 Blue 0
8 AM Fri 59 59 SW 5 1801 2150 0 Blue 0
9 AM Fri 64 65 SW 5 1801 2150 0 Blue 0
10 AM Fri 65 68 SW 5 1801 2150 0 Blue 0
11 AM Fri 67 70 SW 5 1904 2150 0 Blue 0
12 Noon Fri 71 75 SW 5 2447 2150 0 Blue 2
1 PM Fri 73 77 SW 5 2657 2335 185 Blue 4
2 PM Fri 75 79 NW 7 2915 2555 405 Blue 5
3 PM Fri 75 78 NW 7 2786 2445 295 Blue 4
4 PM Fri 76 78 NW 7 2786 2445 295 Blue 4
5 PM Fri 74 75 NW 7 2447 2150 0 Blue 2
6 PM Fri 74 74 NW 7 2337 2150 0 Blue 1
7 PM Fri 71 71 NW 7 2012 2150 0 Blue 0
8 PM Fri 68 68 NW 6 1801 2150 0 Blue 0
9 PM Fri 64 64 NW 6 1801 2150 0 Blue 0
10 PM Fri 62 62 NW 6 1801 2150 0 Blue 0
11 PM Fri 60 60 W 2 1801 2150 0 Blue 0
12 Midnight Sat 59 59 W 2 1801 2150 0 Blue 0
1 AM Sat 58 58 W 2 1801 2150 0 Blue 0
2 AM Sat 57 57 SW 1 1801 2150 0 Blue 0
3 AM Sat 56 56 SW 1 1801 2150 0 Blue 0
4 AM Sat 56 56 SW 1 1801 2150 0 Blue 0
5 AM Sat 55 55 N 3 1801 2150 0 Blue 0
6 AM Sat 55 55 N 3 1801 2150 0 Blue 0
7 AM Sat 55 55 N 3 1801 2150 0 Blue 0
8 AM Sat 59 59 NW 3 1801 2150 0 Blue 0
9 AM Sat 64 66 NW 3 1801 2150 0 Blue 0
10 AM Sat 65 68 NW 3 1801 2150 0 Blue 0
11 AM Sat 67 71 NW 3 2012 2150 0 Blue 0
12 Noon Sat 70 75 NW 3 2447 2150 0 Blue 2
1 PM Sat 72 78 NW 3 2786 2445 295 Blue 4
2 PM Sat 74 79 W 6 2915 2555 405 Blue 5
3 PM Sat 74 78 W 6 2786 2445 295 Blue 4
4 PM Sat 74 77 W 6 2657 2335 185 Blue 4
5 PM Sat 73 74 W 7 2337 2150 0 Blue 1
6 PM Sat 72 72 W 7 2120 2150 0 Blue 0
7 PM Sat 69 69 W 7 1801 2150 0 Blue 0
8 PM Sat 66 66 W 5 1801 2150 0 Blue 0
9 PM Sat 62 62 W 5 1801 2150 0 Blue 0
10 PM Sat 60 60 W 5 1801 2150 0 Blue 0
11 PM Sat 58 58 SW 3 1801 2150 0 Blue 0
12 Midnight Sun 57 57 SW 3 1801 2150 0 Blue 0
1 AM Sun 56 56 SW 3 1801 2150 0 Blue 0
2 AM Sun 55 55 SW 5 1801 2150 0 Blue 0
3 AM Sun 53 53 SW 5 1801 2150 0 Blue 0
4 AM Sun 54 54 SW 5 1801 2150 0 Blue 0
5 AM Sun 53 53 SW 3 1801 2150 0 Blue 0
6 AM Sun 53 53 SW 3 1801 2150 0 Blue 0
7 AM Sun 53 53 SW 3 1801 2150 0 Blue 0
8 AM Sun 56 56 SW 3 1801 2150 0 Blue 0
9 AM Sun 60 61 SW 3 1801 2150 0 Blue 0
10 AM Sun 61 64 SW 3 1801 2150 0 Blue 0
11 AM Sun 63 67 SW 10 1801 2150 0 Blue 0
12 Noon Sun 66 70 SW 10 1904 2150 0 Blue 0
1 PM Sun 67 72 SW 10 2120 2150 0 Blue 0
2 PM Sun 69 73 SW 10 2228 2150 0 Blue 0
3 PM Sun 69 73 SW 10 2228 2150 0 Blue 0
4 PM Sun 70 72 SW 10 2120 2150 0 Blue 0
5 PM Sun 69 70 SW 10 1904 2150 0 Blue 0
6 PM Sun 68 68 SW 10 1801 2150 0 Blue 0
7 PM Sun 65 65 SW 10 1801 2150 0 Blue 0
8 PM Sun 63 63 SW 10 1801 2150 0 Blue 0
9 PM Sun 59 59 SW 10 1801 2150 0 Blue 0
10 PM Sun 57 57 SW 10 1801 2150 0 Blue 0
11 PM Sun 56 56 SW 7 1801 2150 0 Blue 0
12 Midnight Mon 55 55 SW 7 1801 2150 0 Blue 0
1 AM Mon 53 53 SW 7 1801 2150 0 Blue 0
2 AM Mon 52 52 SW 7 1801 2150 0 Blue 0
3 AM Mon 51 51 SW 7 1801 2150 0 Blue 0
4 AM Mon 52 52 SW 7 1801 2150 0 Blue 0
5 AM Mon 51 51 SW 7 1801 2150 0 Blue 0
6 AM Mon 51 51 SW 7 1801 2150 0 Blue 0
7 AM Mon 51 51 SW 7 1801 2150 0 Blue 0
8 AM Mon 54 54 SW 7 1801 2150 0 Blue 0
9 AM Mon 58 60 SW 7 1801 2150 0 Blue 0
10 AM Mon 59 62 SW 7 1801 2150 0 Blue 0
11 AM Mon 60 65 SW 10 1801 2150 0 Blue 0
12 Noon Mon 63 69 SW 10 1801 2150 0 Blue 0
1 PM Mon 64 71 SW 10 2012 2150 0 Blue 0
2 PM Mon 66 72 SW 10 2120 2150 0 Blue 0
3 PM Mon 66 71 SW 10 2012 2150 0 Blue 0
4 PM Mon 66 69 SW 10 1801 2150 0 Blue 0
5 PM Mon 65 67 SW 10 1801 2150 0 Blue 0
6 PM Mon 64 64 SW 10 1801 2150 0 Blue 0
7 PM Mon 62 62 SW 10 1801 2150 0 Blue 0
8 PM Mon 60 60 SW 10 1801 2150 0 Blue 0
9 PM Mon 57 57 SW 10 1801 2150 0 Blue 0
10 PM Mon 54 54 SW 10 1801 2150 0 Blue 0
11 PM Mon 53 53 S 8 1801 2150 0 Blue 0
12 Midnight Tue 52 52 S 8 1801 2150 0 Blue 0
1 AM Tue 51 51 S 8 1801 2150 0 Blue 0
2 AM Tue 50 50 S 8 1801 2150 0 Blue 0
3 AM Tue 49 49 S 8 1801 2150 0 Blue 0
4 AM Tue 50 50 S 8 1801 2150 0 Blue 0
5 AM Tue 49 49 S 9 1801 2150 0 Blue 0
6 AM Tue 49 49 S 9 1801 2150 0 Blue 0
7 AM Tue 49 49 S 9 1801 2150 0 Blue 0
8 AM Tue 51 51 S 9 1801 2150 0 Blue 0
9 AM Tue 55 57 S 9 1801 2150 0 Blue 0
10 AM Tue 56 59 S 9 1801 2150 0 Blue 0
11 AM Tue 57 62 W 14 1801 2150 0 Blue 0
12 Noon Tue 60 66 W 14 1801 2150 0 Blue 0
1 PM Tue 61 68 W 14 1801 2150 0 Blue 0
2 PM Tue 62 68 W 14 1801 2150 0 Blue 0
3 PM Tue 63 68 W 14 1801 2150 0 Blue 0
4 PM Tue 63 67 W 14 1801 2150 0 Blue 0
5 PM Tue 62 64 W 13 1801 2150 0 Blue 0
6 PM Tue 61 61 W 13 1801 2150 0 Blue 0
7 PM Tue 59 59 W 13 1801 2150 0 Blue 0
8 PM Tue 57 57 W 13 1801 2150 0 Blue 0
9 PM Tue 55 55 W 13 1801 2150 0 Blue 0
10 PM Tue 53 53 W 13 1801 2150 0 Blue 0
11 PM Tue 52 52 W 8 1801 2150 0 Blue 0
12 Midnight Wed 51 51 W 8 1801 2150 0 Blue 0
1 AM Wed 50 50 W 8 1801 2150 0 Blue 0
2 AM Wed 49 49 W 8 1801 2150 0 Blue 0
3 AM Wed 48 48 W 8 1801 2150 0 Blue 0
4 AM Wed 49 49 W 8 1801 2150 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 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