Detailed Predictions for: Ed Levin
Launch Lat, Long, Altitude (f): 37.475633, -121.86, 2150
LZ Altitude (f): 400
Sounding

Station:

 KOAK

Date/Time:

 25 APR 2024

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 49 49 WNW 6 9 2368 2150 0 Blue 3
1 AM Thu 48 48 WNW 6 8 2312 2150 0 Blue 2
2 AM Thu 48 48 W 5 6 2312 2150 0 Blue 2
3 AM Thu 47 47 W 5 6 2257 2150 0 Blue 1
4 AM Thu 46 46 W 5 6 2149 2150 0 White 0
5 AM Thu 47 47 WSW 5 6 2257 2150 0 Blue 1
6 AM Thu 47 47 WSW 6 6 2257 2150 0 Blue 1
7 AM Thu 47 47 SW 8 9 2257 2150 0 Blue 1
8 AM Thu 48 48 WSW 9 10 2312 2150 0 Blue 2
9 AM Thu 48 48 WSW 10 12 2312 2150 0 Blue 2
10 AM Thu 49 50 WSW 10 13 2423 2256 106 Blue 4
11 AM Thu 50 52 WSW 12 14 2952 2367 217 Blue 6
12 Noon Thu 52 55 W 14 19 4123 2926 776 Blue 9
1 PM Thu 53 56 W 18 23 4359 3599 1449 White 10
2 PM Thu 53 56 W 20 24 4359 3599 1449 White 10
3 PM Thu 55 57 W 20 26 4575 3961 1811 White 11
4 PM Thu 53 54 W 20 26 3927 2508 358 White 8
5 PM Thu 53 54 W 20 26 3927 2508 358 White 8
6 PM Thu 52 52 W 20 26 2952 2367 217 Blue 6
7 PM Thu 51 51 W 19 25 2512 2311 161 Blue 5
8 PM Thu 51 51 W 18 23 2512 2311 161 Blue 5
9 PM Thu 51 51 W 18 23 2512 2311 161 Blue 5
10 PM Thu 50 50 W 16 21 2423 2256 106 Blue 4
11 PM Thu 50 50 W 16 20 2423 2256 106 Blue 4
12 Midnight Fri 50 50 W 13 18 2423 2256 106 Blue 4
1 AM Fri 50 50 W 13 18 2423 2256 106 Blue 4
2 AM Fri 50 50 W 13 17 2423 2256 106 Blue 4
3 AM Fri 50 50 WSW 13 18 2423 2256 106 Blue 4
4 AM Fri 50 50 W 14 20 2423 2256 106 Blue 4
5 AM Fri 50 50 W 17 24 2423 2256 106 Blue 4
6 AM Fri 49 49 WNW 17 23 2368 2150 0 Blue 3
7 AM Fri 49 49 WNW 18 23 2368 2150 0 Blue 3
8 AM Fri 49 49 W 20 25 2368 2150 0 Blue 3
9 AM Fri 49 49 WNW 20 24 2368 2150 0 Blue 3
10 AM Fri 49 50 WNW 20 24 2423 2256 106 Blue 4
11 AM Fri 50 52 W 21 27 2952 2367 217 Blue 6
12 Noon Fri 52 55 W 21 27 4123 2926 776 Blue 9
1 PM Fri 53 56 W 21 27 4359 3599 1449 White 10
2 PM Fri 53 56 W 25 31 4359 3599 1449 White 10
3 PM Fri 53 55 W 25 31 4123 2926 776 Blue 9
4 PM Fri 52 53 W 25 31 3709 2422 272 White 7
5 PM Fri 52 53 WNW 25 35 3709 2422 272 White 7
6 PM Fri 51 51 WNW 25 35 2512 2311 161 Blue 5
7 PM Fri 51 51 WNW 25 35 2512 2311 161 Blue 5
8 PM Fri 50 50 W 20 31 2423 2256 106 Blue 4
9 PM Fri 50 50 W 20 31 2423 2256 106 Blue 4
10 PM Fri 49 49 W 20 31 2368 2150 0 Blue 3
11 PM Fri 49 49 W 13 21 2368 2150 0 Blue 3
12 Midnight Sat 48 48 W 13 21 2312 2150 0 Blue 2
1 AM Sat 48 48 W 13 21 2312 2150 0 Blue 2
2 AM Sat 47 47 W 10 13 2257 2150 0 Blue 1
3 AM Sat 46 46 W 10 13 2149 2150 0 White 0
4 AM Sat 46 46 W 10 13 2149 2150 0 White 0
5 AM Sat 45 45 W 5 8 1237 2150 0 Blue 0
6 AM Sat 46 46 W 5 8 2149 2150 0 White 0
7 AM Sat 47 47 W 5 8 2257 2150 0 Blue 1
8 AM Sat 49 49 W 6 9 2368 2150 0 Blue 3
9 AM Sat 50 52 W 6 9 2952 2367 217 Blue 6
10 AM Sat 52 55 W 6 9 4123 2926 776 Blue 9
11 AM Sat 54 60 WNW 11 14 5234 4666 2516 White 14
12 Noon Sat 56 63 WNW 11 14 5875 5875 3725 White 17
1 PM Sat 57 64 WNW 11 14 6088 6088 3938 White 18
2 PM Sat 58 65 W 14 17 6300 6300 4150 White 19
3 PM Sat 59 65 W 14 17 6300 6300 4150 White 19
4 PM Sat 59 63 W 14 17 5875 5875 3725 White 17
5 PM Sat 58 60 W 18 26 5234 4666 2516 White 14
6 PM Sat 56 57 W 18 26 4575 3961 1811 White 11
7 PM Sat 54 54 W 18 26 3927 2508 358 White 8
8 PM Sat 51 51 W 14 20 2512 2311 161 Blue 5
9 PM Sat 50 50 W 14 20 2423 2256 106 Blue 4
10 PM Sat 49 49 W 14 20 2368 2150 0 Blue 3
11 PM Sat 48 48 WSW 10 14 2312 2150 0 Blue 2
12 Midnight Sun 48 48 WSW 10 14 2312 2150 0 Blue 2
1 AM Sun 48 48 WSW 10 14 2312 2150 0 Blue 2
2 AM Sun 48 48 SW 8 12 2312 2150 0 Blue 2
3 AM Sun 48 48 SW 8 12 2312 2150 0 Blue 2
4 AM Sun 48 48 SW 8 12 2312 2150 0 Blue 2
5 AM Sun 48 48 SW 6 10 2312 2150 0 Blue 2
6 AM Sun 48 48 SW 6 10 2312 2150 0 Blue 2
7 AM Sun 49 49 SW 6 10 2368 2150 0 Blue 3
8 AM Sun 51 51 WSW 6 11 2512 2311 161 Blue 5
9 AM Sun 53 55 WSW 6 11 4123 2926 776 Blue 9
10 AM Sun 55 58 WSW 6 11 4746 4111 1961 Blue 12
11 AM Sun 57 63 W 11 14 5875 5875 3725 White 17
12 Noon Sun 59 66 W 11 14 6512 6512 4362 White 20
1 PM Sun 60 67 W 11 14 6722 6722 4572 White 21
2 PM Sun 61 68 WNW 13 19 6931 6882 4732 White 22
3 PM Sun 61 67 WNW 13 19 6722 6722 4572 White 21
4 PM Sun 60 64 WNW 13 19 6088 6088 3938 White 18
5 PM Sun 59 61 W 16 21 5447 4739 2589 White 15
6 PM Sun 57 58 W 16 21 4746 4111 1961 Blue 12
7 PM Sun 55 55 W 16 21 4123 2926 776 Blue 9
8 PM Sun 53 53 W 13 18 3709 2422 272 White 7
9 PM Sun 52 52 W 13 18 2952 2367 217 Blue 6
10 PM Sun 50 50 W 13 18 2423 2256 106 Blue 4
11 PM Sun 49 49 WSW 9 13 2368 2150 0 Blue 3
12 Midnight Mon 48 48 WSW 9 13 2312 2150 0 Blue 2
1 AM Mon 48 48 WSW 9 13 2312 2150 0 Blue 2
2 AM Mon 47 47 WSW 9 12 2257 2150 0 Blue 1
3 AM Mon 46 46 WSW 9 12 2149 2150 0 White 0
4 AM Mon 46 46 WSW 9 12 2149 2150 0 White 0
5 AM Mon 46 46 SW 8 11 2149 2150 0 White 0
6 AM Mon 46 46 SW 8 11 2149 2150 0 White 0
7 AM Mon 47 47 SW 8 11 2257 2150 0 Blue 1
8 AM Mon 49 50 WSW 9 11 2423 2256 106 Blue 4
9 AM Mon 51 53 WSW 9 11 3709 2422 272 White 7
10 AM Mon 53 57 WSW 9 11 4575 3961 1811 White 11
11 AM Mon 55 61 WNW 10 14 5447 4739 2589 White 15
12 Noon Mon 58 65 WNW 10 14 6300 6300 4150 White 19
1 PM Mon 60 68 WNW 10 14 6931 6882 4732 White 22
2 PM Mon 61 68 WNW 13 18 6931 6882 4732 White 22
3 PM Mon 62 68 WNW 13 18 6931 6882 4732 White 22
4 PM Mon 62 66 WNW 13 18 6512 6512 4362 White 20
5 PM Mon 61 63 WNW 14 19 5875 5875 3725 White 17
6 PM Mon 59 60 WNW 14 19 5234 4666 2516 White 14
7 PM Mon 57 57 WNW 14 19 4575 3961 1811 White 11
8 PM Mon 54 54 W 12 17 3927 2508 358 White 8
9 PM Mon 53 53 W 12 17 3709 2422 272 White 7
10 PM Mon 52 52 W 12 17 2952 2367 217 Blue 6
11 PM Mon 51 51 WSW 9 11 2512 2311 161 Blue 5
12 Midnight Tue 50 50 WSW 9 11 2423 2256 106 Blue 4
1 AM Tue 50 50 WSW 9 11 2423 2256 106 Blue 4
2 AM Tue 49 49 SW 6 10 2368 2150 0 Blue 3
3 AM Tue 48 48 SW 6 10 2312 2150 0 Blue 2
4 AM Tue 47 47 SW 6 10 2257 2150 0 Blue 1
5 AM Tue 47 47 WSW 5 9 2257 2150 0 Blue 1
6 AM Tue 48 48 WSW 5 9 2312 2150 0 Blue 2
7 AM Tue 49 49 WSW 5 9 2368 2150 0 Blue 3
8 AM Tue 51 52 W 6 11 2952 2367 217 Blue 6
9 AM Tue 54 56 W 6 11 4359 3599 1449 White 10
10 AM Tue 57 61 W 6 11 5447 4739 2589 White 15
11 AM Tue 60 66 WNW 10 13 6512 6512 4362 White 20
12 Noon Tue 63 70 WNW 10 13 7055 6920 4770 Blue 24
1 PM Tue 65 72 WNW 10 13 7776 7000 4850 White 26
2 PM Tue 66 73 WNW 12 17 7987 7047 4897 White 27
3 PM Tue 66 72 WNW 12 17 7776 7000 4850 White 26
4 PM Tue 65 69 WNW 12 17 7008 6896 4746 Blue 23
5 PM Tue 63 65 WNW 16 20 6300 6300 4150 White 19
6 PM Tue 61 62 WNW 16 20 5661 4813 2663 White 16
7 PM Tue 58 58 WNW 16 20 4746 4111 1961 Blue 12
8 PM Tue 55 55 W 12 17 4123 2926 776 Blue 9
9 PM Tue 53 53 W 12 17 3709 2422 272 White 7
10 PM Tue 52 52 W 12 17 2952 2367 217 Blue 6

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 [email protected]