Detailed Predictions for: Ed Levin
Launch Altitude (f): 2150
LZ Altitude (f): 400
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 54 54 W 5 2405 2371 221 Blue 10
6 AM Thu 53 53 W 5 2394 2360 210 Blue 9
7 AM Thu 54 54 W 5 2405 2371 221 Blue 10
8 AM Thu 56 56 W 6 2427 2393 243 Blue 12
9 AM Thu 56 56 W 6 2427 2393 243 Blue 12
10 AM Thu 57 58 W 6 2449 2415 265 Blue 14
11 AM Thu 58 64 W 10 2616 2505 355 Blue 20
12 Noon Thu 59 66 W 10 2793 2556 406 Blue 22
1 PM Thu 60 68 W 10 2971 2702 552 Blue 24
2 PM Thu 61 68 NW 14 2971 2702 552 Blue 24
3 PM Thu 61 67 NW 14 2882 2613 463 Blue 23
4 PM Thu 61 65 NW 14 2705 2529 379 Blue 21
5 PM Thu 60 62 NW 14 2529 2459 309 Blue 18
6 PM Thu 57 57 NW 14 2438 2404 254 Blue 13
7 PM Thu 52 52 NW 14 2383 2349 199 Blue 8
8 PM Thu 49 49 NW 8 2350 2316 166 Blue 5
9 PM Thu 48 48 NW 8 2339 2273 123 Blue 4
10 PM Thu 48 48 NW 8 2339 2273 123 Blue 4
11 PM Thu 48 48 W 6 2339 2273 123 Blue 4
12 Midnight Fri 48 48 W 6 2339 2273 123 Blue 4
1 AM Fri 48 48 W 6 2339 2273 123 Blue 4
2 AM Fri 47 47 W 5 2328 2206 56 Blue 3
3 AM Fri 48 48 W 5 2339 2273 123 Blue 4
4 AM Fri 48 48 W 5 2339 2273 123 Blue 4
5 AM Fri 47 47 W 3 2328 2206 56 Blue 3
6 AM Fri 46 46 W 3 2317 2150 0 Blue 2
7 AM Fri 47 47 W 3 2328 2206 56 Blue 3
8 AM Fri 49 49 W 6 2350 2316 166 Blue 5
9 AM Fri 49 50 W 6 2361 2327 177 Blue 6
10 AM Fri 51 53 W 6 2394 2360 210 Blue 9
11 AM Fri 52 57 W 8 2438 2404 254 Blue 13
12 Noon Fri 53 59 W 8 2460 2426 276 Blue 15
1 PM Fri 55 61 W 8 2506 2448 298 Blue 17
2 PM Fri 55 61 W 13 2506 2448 298 Blue 17
3 PM Fri 56 61 W 13 2506 2448 298 Blue 17
4 PM Fri 56 59 W 13 2460 2426 276 Blue 15
5 PM Fri 55 57 W 15 2438 2404 254 Blue 13
6 PM Fri 53 53 W 15 2394 2360 210 Blue 9
7 PM Fri 49 49 W 15 2350 2316 166 Blue 5
8 PM Fri 47 47 W 15 2328 2206 56 Blue 3
9 PM Fri 47 47 W 15 2328 2206 56 Blue 3
10 PM Fri 46 46 W 15 2317 2150 0 Blue 2
11 PM Fri 46 46 W 10 2317 2150 0 Blue 2
12 Midnight Sat 46 46 W 10 2317 2150 0 Blue 2
1 AM Sat 47 47 W 10 2328 2206 56 Blue 3
2 AM Sat 46 46 W 10 2317 2150 0 Blue 2
3 AM Sat 47 47 W 10 2328 2206 56 Blue 3
4 AM Sat 47 47 W 10 2328 2206 56 Blue 3
5 AM Sat 46 46 W 9 2317 2150 0 Blue 2
6 AM Sat 46 46 W 9 2317 2150 0 Blue 2
7 AM Sat 47 47 W 9 2328 2206 56 Blue 3
8 AM Sat 48 48 W 9 2339 2273 123 Blue 4
9 AM Sat 48 48 W 9 2339 2273 123 Blue 4
10 AM Sat 50 50 W 9 2361 2327 177 Blue 6
11 AM Sat 51 54 W 14 2405 2371 221 Blue 10
12 Noon Sat 52 55 W 14 2416 2382 232 Blue 11
1 PM Sat 53 56 W 14 2427 2393 243 Blue 12
2 PM Sat 54 57 W 14 2438 2404 254 Blue 13
3 PM Sat 54 57 W 14 2438 2404 254 Blue 13
4 PM Sat 54 56 W 14 2427 2393 243 Blue 12
5 PM Sat 54 55 NW 16 2416 2382 232 Blue 11
6 PM Sat 52 52 NW 16 2383 2349 199 Blue 8
7 PM Sat 49 49 NW 16 2350 2316 166 Blue 5
8 PM Sat 48 48 NW 16 2339 2273 123 Blue 4
9 PM Sat 48 48 NW 16 2339 2273 123 Blue 4
10 PM Sat 47 47 NW 16 2328 2206 56 Blue 3
11 PM Sat 47 47 W 6 2328 2206 56 Blue 3
12 Midnight Sun 47 47 W 6 2328 2206 56 Blue 3
1 AM Sun 47 47 W 6 2328 2206 56 Blue 3
2 AM Sun 47 47 W 6 2328 2206 56 Blue 3
3 AM Sun 47 47 W 6 2328 2206 56 Blue 3
4 AM Sun 47 47 W 6 2328 2206 56 Blue 3
5 AM Sun 47 47 SW 3 2328 2206 56 Blue 3
6 AM Sun 46 46 SW 3 2317 2150 0 Blue 2
7 AM Sun 48 48 SW 3 2339 2273 123 Blue 4
8 AM Sun 49 49 SW 3 2350 2316 166 Blue 5
9 AM Sun 50 51 SW 3 2372 2338 188 Blue 7
10 AM Sun 51 54 SW 3 2405 2371 221 Blue 10
11 AM Sun 52 56 W 10 2427 2393 243 Blue 12
12 Noon Sun 53 58 W 10 2449 2415 265 Blue 14
1 PM Sun 55 60 W 10 2482 2437 287 Blue 16
2 PM Sun 55 60 W 10 2482 2437 287 Blue 16
3 PM Sun 56 60 W 10 2482 2437 287 Blue 16
4 PM Sun 56 58 W 10 2449 2415 265 Blue 14
5 PM Sun 55 57 W 12 2438 2404 254 Blue 13
6 PM Sun 54 54 W 12 2405 2371 221 Blue 10
7 PM Sun 51 51 W 12 2372 2338 188 Blue 7
8 PM Sun 49 49 W 12 2350 2316 166 Blue 5
9 PM Sun 49 49 W 12 2350 2316 166 Blue 5
10 PM Sun 49 49 W 12 2350 2316 166 Blue 5
11 PM Sun 49 49 W 7 2350 2316 166 Blue 5
12 Midnight Mon 49 49 W 7 2350 2316 166 Blue 5
1 AM Mon 49 49 W 7 2350 2316 166 Blue 5
2 AM Mon 48 48 W 7 2339 2273 123 Blue 4
3 AM Mon 49 49 W 7 2350 2316 166 Blue 5
4 AM Mon 49 49 W 7 2350 2316 166 Blue 5
5 AM Mon 48 48 W 3 2339 2273 123 Blue 4
6 AM Mon 48 48 W 3 2339 2273 123 Blue 4
7 AM Mon 49 49 W 3 2350 2316 166 Blue 5
8 AM Mon 51 51 W 3 2372 2338 188 Blue 7
9 AM Mon 51 53 W 3 2394 2360 210 Blue 9
10 AM Mon 53 56 W 3 2427 2393 243 Blue 12
11 AM Mon 54 58 W 6 2449 2415 265 Blue 14
12 Noon Mon 56 61 W 6 2506 2448 298 Blue 17
1 PM Mon 57 63 W 6 2557 2482 332 Blue 19
2 PM Mon 58 63 W 6 2557 2482 332 Blue 19
3 PM Mon 58 62 W 6 2529 2459 309 Blue 18
4 PM Mon 58 61 W 6 2506 2448 298 Blue 17
5 PM Mon 58 59 W 13 2460 2426 276 Blue 15
6 PM Mon 56 56 W 13 2427 2393 243 Blue 12
7 PM Mon 53 53 W 13 2394 2360 210 Blue 9
8 PM Mon 52 52 W 13 2383 2349 199 Blue 8
9 PM Mon 51 51 W 13 2372 2338 188 Blue 7
10 PM Mon 51 51 W 13 2372 2338 188 Blue 7
11 PM Mon 51 51 SW 6 2372 2338 188 Blue 7
12 Midnight Tue 51 51 SW 6 2372 2338 188 Blue 7
1 AM Tue 51 51 SW 6 2372 2338 188 Blue 7
2 AM Tue 51 51 SW 6 2372 2338 188 Blue 7
3 AM Tue 51 51 SW 6 2372 2338 188 Blue 7
4 AM Tue 51 51 SW 6 2372 2338 188 Blue 7
5 AM Tue 50 50 S 2 2361 2327 177 Blue 6
6 AM Tue 50 50 S 2 2361 2327 177 Blue 6
7 AM Tue 52 52 S 2 2383 2349 199 Blue 8
8 AM Tue 54 55 S 2 2416 2382 232 Blue 11
9 AM Tue 54 56 S 2 2427 2393 243 Blue 12
10 AM Tue 56 60 S 2 2482 2437 287 Blue 16
11 AM Tue 58 63 N 9 2557 2482 332 Blue 19
12 Noon Tue 60 66 N 9 2793 2556 406 Blue 22
1 PM Tue 62 69 N 9 3060 2790 640 Blue 25
2 PM Tue 63 69 N 9 3060 2790 640 Blue 25
3 PM Tue 63 68 N 9 2971 2702 552 Blue 24
4 PM Tue 63 67 N 9 2882 2613 463 Blue 23
5 PM Tue 63 65 W 14 2705 2529 379 Blue 21
6 PM Tue 61 61 W 14 2506 2448 298 Blue 17
7 PM Tue 58 58 W 14 2449 2415 265 Blue 14
8 PM Tue 57 57 W 14 2438 2404 254 Blue 13
9 PM Tue 56 56 W 14 2427 2393 243 Blue 12
10 PM Tue 56 56 W 14 2427 2393 243 Blue 12
11 PM Tue 56 56 SW 5 2427 2393 243 Blue 12
12 Midnight Wed 56 56 SW 5 2427 2393 243 Blue 12
1 AM Wed 56 56 SW 5 2427 2393 243 Blue 12
2 AM Wed 56 56 SW 5 2427 2393 243 Blue 12
3 AM Wed 56 56 SW 5 2427 2393 243 Blue 12
4 AM Wed 56 56 SW 5 2427 2393 243 Blue 12

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