Detailed Predictions for: Potato Hill
Launch Altitude (f): 3400
LZ Altitude (f): 1700
Sounding

Station:

KOAK

Date/Time:

15 JUN 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 Sat 66 64 N 8 3246 3400 0 Blue 5
6 AM Sat 66 64 N 8 3246 3400 0 Blue 5
7 AM Sat 68 66 N 8 3295 3400 0 Blue 7
8 AM Sat 70 69 N 10 3367 3400 0 Blue 10
9 AM Sat 74 75 N 10 3454 3410 10 Blue 16
10 AM Sat 77 79 N 10 3552 3468 68 Blue 20
11 AM Sat 80 83 E 8 4809 3700 300 Blue 24
12 Noon Sat 82 86 E 8 5726 4797 1397 Blue 27
1 PM Sat 83 87 E 8 7688 5047 1647 Blue 28
2 PM Sat 83 87 SE 12 7688 5047 1647 Blue 28
3 PM Sat 83 86 SE 12 5726 4797 1397 Blue 27
4 PM Sat 83 85 SE 12 5400 4484 1084 Blue 26
5 PM Sat 83 83 SE 8 4809 3700 300 Blue 24
6 PM Sat 82 81 SE 8 3861 3508 108 Blue 22
7 PM Sat 81 79 SE 8 3552 3468 68 Blue 20
8 PM Sat 79 77 E 8 3482 3439 39 Blue 18
9 PM Sat 76 74 E 8 3439 3400 0 Blue 15
10 PM Sat 74 72 E 8 3410 3400 0 Blue 13
11 PM Sat 71 69 SE 6 3367 3400 0 Blue 10
12 Midnight Sun 70 68 SE 6 3344 3400 0 Blue 9
1 AM Sun 70 68 SE 6 3344 3400 0 Blue 9
2 AM Sun 69 67 N 3 3319 3400 0 Blue 8
3 AM Sun 67 65 N 3 3270 3400 0 Blue 6
4 AM Sun 66 64 N 3 3246 3400 0 Blue 5
5 AM Sun 65 63 N 2 3222 3400 0 Blue 4
6 AM Sun 66 64 N 2 3246 3400 0 Blue 5
7 AM Sun 69 67 N 2 3319 3400 0 Blue 8
8 AM Sun 72 71 N 2 3396 3400 0 Blue 12
9 AM Sun 77 78 N 2 3509 3453 53 Blue 19
10 AM Sun 81 83 N 2 4809 3700 300 Blue 24
11 AM Sun 84 86 E 6 5726 4797 1397 Blue 27
12 Noon Sun 86 89 E 6 9147 5696 2296 Blue 30
1 PM Sun 87 91 E 6 10325 8391 4991 Blue 32
2 PM Sun 87 91 SE 12 10325 8391 4991 Blue 32
3 PM Sun 87 90 SE 12 9749 7483 4083 Blue 31
4 PM Sun 87 89 SE 12 9147 5696 2296 Blue 30
5 PM Sun 86 86 SE 8 5726 4797 1397 Blue 27
6 PM Sun 85 84 SE 8 5071 3856 456 Blue 25
7 PM Sun 83 81 SE 8 3861 3508 108 Blue 22
8 PM Sun 81 79 SE 8 3552 3468 68 Blue 20
9 PM Sun 78 76 SE 8 3468 3424 24 Blue 17
10 PM Sun 75 73 SE 8 3425 3400 0 Blue 14
11 PM Sun 73 71 NE 6 3396 3400 0 Blue 12
12 Midnight Mon 72 70 NE 6 3382 3400 0 Blue 11
1 AM Mon 71 69 NE 6 3367 3400 0 Blue 10
2 AM Mon 70 68 NE 6 3344 3400 0 Blue 9
3 AM Mon 68 66 NE 6 3295 3400 0 Blue 7
4 AM Mon 67 65 NE 6 3270 3400 0 Blue 6
5 AM Mon 67 65 N 6 3270 3400 0 Blue 6
6 AM Mon 68 66 N 6 3295 3400 0 Blue 7
7 AM Mon 70 68 N 6 3344 3400 0 Blue 9
8 AM Mon 74 73 N 6 3425 3400 0 Blue 14
9 AM Mon 79 80 N 6 3705 3482 82 Blue 21
10 AM Mon 84 87 N 6 7688 5047 1647 Blue 28
11 AM Mon 87 91 NE 6 10325 8391 4991 Blue 32
12 Noon Mon 90 95 NE 6 13017 10702 7302 Blue 36
1 PM Mon 91 97 NE 6 13469 12469 9069 Blue 38
2 PM Mon 91 96 NE 6 13344 12154 8754 Blue 37
3 PM Mon 92 96 NE 6 13344 12154 8754 Blue 37
4 PM Mon 92 95 NE 6 13017 10702 7302 Blue 36
5 PM Mon 92 93 NE 7 12252 9618 6218 Blue 34
6 PM Mon 91 90 NE 7 9749 7483 4083 Blue 31
7 PM Mon 89 87 NE 7 7688 5047 1647 Blue 28
8 PM Mon 86 84 NE 7 5071 3856 456 Blue 25
9 PM Mon 83 81 NE 7 3861 3508 108 Blue 22
10 PM Mon 80 78 NE 7 3509 3453 53 Blue 19
11 PM Mon 78 76 N 6 3468 3424 24 Blue 17
12 Midnight Tue 76 74 N 6 3439 3400 0 Blue 15
1 AM Tue 76 74 N 6 3439 3400 0 Blue 15
2 AM Tue 75 73 N 6 3425 3400 0 Blue 14
3 AM Tue 74 72 N 6 3410 3400 0 Blue 13
4 AM Tue 73 71 N 6 3396 3400 0 Blue 12
5 AM Tue 72 70 N 7 3382 3400 0 Blue 11
6 AM Tue 73 71 N 7 3396 3400 0 Blue 12
7 AM Tue 75 73 N 7 3425 3400 0 Blue 14
8 AM Tue 78 77 N 7 3482 3439 39 Blue 18
9 AM Tue 83 84 N 7 5071 3856 456 Blue 25
10 AM Tue 89 92 N 7 10909 9023 5623 Blue 33
11 AM Tue 93 97 NE 7 13469 12469 9069 Blue 38
12 Noon Tue 96 102 NE 7 14898 13673 10273 Blue 43
1 PM Tue 96 102 NE 7 14898 13673 10273 Blue 43
2 PM Tue 97 103 NE 7 15414 13797 10397 Blue 44
3 PM Tue 97 102 NE 7 14898 13673 10273 Blue 43
4 PM Tue 97 100 NE 7 13843 13425 10025 Blue 41
5 PM Tue 97 98 W 7 13593 12791 9391 Blue 39
6 PM Tue 95 94 W 7 12570 10191 6791 Blue 35
7 PM Tue 92 90 W 7 9749 7483 4083 Blue 31
8 PM Tue 89 87 W 7 7688 5047 1647 Blue 28
9 PM Tue 85 83 W 7 4809 3700 300 Blue 24
10 PM Tue 82 80 W 7 3705 3482 82 Blue 21
11 PM Tue 79 77 NW 7 3482 3439 39 Blue 18
12 Midnight Wed 77 75 NW 7 3454 3410 10 Blue 16
1 AM Wed 76 74 NW 7 3439 3400 0 Blue 15
2 AM Wed 74 72 NW 7 3410 3400 0 Blue 13
3 AM Wed 72 70 NW 7 3382 3400 0 Blue 11
4 AM Wed 70 68 NW 7 3344 3400 0 Blue 9
5 AM Wed 69 67 N 5 3319 3400 0 Blue 8
6 AM Wed 70 68 N 5 3344 3400 0 Blue 9
7 AM Wed 72 70 N 5 3382 3400 0 Blue 11
8 AM Wed 76 75 N 5 3454 3410 10 Blue 16
9 AM Wed 82 83 N 5 4809 3700 300 Blue 24
10 AM Wed 87 90 N 5 9749 7483 4083 Blue 31
11 AM Wed 92 97 E 6 13469 12469 9069 Blue 38
12 Noon Wed 94 100 E 6 13843 13425 10025 Blue 41
1 PM Wed 95 102 E 6 14898 13673 10273 Blue 43
2 PM Wed 95 101 E 6 14364 13549 10149 Blue 42
3 PM Wed 96 101 E 6 14364 13549 10149 Blue 42
4 PM Wed 97 100 E 6 13843 13425 10025 Blue 41
5 PM Wed 97 98 SW 8 13593 12791 9391 Blue 39
6 PM Wed 95 95 SW 8 13017 10702 7302 Blue 36
7 PM Wed 92 90 SW 8 9749 7483 4083 Blue 31
8 PM Wed 88 86 SW 8 5726 4797 1397 Blue 27
9 PM Wed 84 82 SW 8 4590 3551 151 Blue 23
10 PM Wed 81 79 SW 8 3552 3468 68 Blue 20
11 PM Wed 78 76 W 6 3468 3424 24 Blue 17
12 Midnight Thu 76 74 W 6 3439 3400 0 Blue 15
1 AM Thu 74 72 W 6 3410 3400 0 Blue 13
2 AM Thu 72 70 W 6 3382 3400 0 Blue 11
3 AM Thu 70 68 W 6 3344 3400 0 Blue 9
4 AM Thu 68 66 W 6 3295 3400 0 Blue 7
5 AM Thu 67 65 N 6 3270 3400 0 Blue 6
6 AM Thu 68 66 N 6 3295 3400 0 Blue 7
7 AM Thu 71 69 N 6 3367 3400 0 Blue 10
8 AM Thu 75 74 N 6 3439 3400 0 Blue 15
9 AM Thu 79 80 N 6 3705 3482 82 Blue 21
10 AM Thu 84 87 N 6 7688 5047 1647 Blue 28
11 AM Thu 88 93 NE 8 12252 9618 6218 Blue 34
12 Noon Thu 90 96 NE 8 13344 12154 8754 Blue 37
1 PM Thu 91 98 NE 8 13593 12791 9391 Blue 39
2 PM Thu 91 97 NE 8 13469 12469 9069 Blue 38
3 PM Thu 92 97 NE 8 13469 12469 9069 Blue 38
4 PM Thu 92 95 NE 8 13017 10702 7302 Blue 36
5 PM Thu 91 92 SW 9 10909 9023 5623 Blue 33
6 PM Thu 90 90 SW 9 9749 7483 4083 Blue 31
7 PM Thu 87 85 SW 9 5400 4484 1084 Blue 26
8 PM Thu 85 83 SW 9 4809 3700 300 Blue 24
9 PM Thu 81 79 SW 9 3552 3468 68 Blue 20
10 PM Thu 78 76 SW 9 3468 3424 24 Blue 17
11 PM Thu 75 73 NW 8 3425 3400 0 Blue 14
12 Midnight Fri 73 71 NW 8 3396 3400 0 Blue 12
1 AM Fri 71 69 NW 8 3367 3400 0 Blue 10
2 AM Fri 70 68 NW 8 3344 3400 0 Blue 9
3 AM Fri 67 65 NW 8 3270 3400 0 Blue 6
4 AM Fri 66 64 NW 8 3246 3400 0 Blue 5

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