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

Station:

KOAK

Date/Time:

19 JUN 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 Tue 62 60 NW 3 2720 3400 0 Blue 0
6 AM Tue 64 62 NW 3 2743 3400 0 Blue 0
7 AM Tue 67 65 NW 3 2793 3400 0 Blue 0
8 AM Tue 71 70 N 2 2891 3400 0 Blue 0
9 AM Tue 74 75 N 2 6174 3400 0 Blue 5
10 AM Tue 78 80 N 2 8831 7250 3850 Blue 10
11 AM Tue 81 85 NE 5 9465 9142 5742 Blue 15
12 Noon Tue 84 89 NE 5 9859 9541 6141 Blue 19
1 PM Tue 85 90 NE 5 10204 9637 6237 Blue 20
2 PM Tue 86 91 E 5 10591 9733 6333 Blue 21
3 PM Tue 87 91 E 5 10591 9733 6333 Blue 21
4 PM Tue 87 90 E 5 10204 9637 6237 Blue 20
5 PM Tue 85 86 W 6 9562 9252 5852 Blue 16
6 PM Tue 82 81 W 6 9005 7798 4398 Blue 11
7 PM Tue 79 77 W 6 7281 5710 2310 Blue 7
8 PM Tue 75 73 W 7 5038 3400 0 Blue 3
9 PM Tue 72 70 W 7 2891 3400 0 Blue 0
10 PM Tue 70 68 W 7 2844 3400 0 Blue 0
11 PM Tue 69 67 W 3 2827 3400 0 Blue 0
12 Midnight Wed 68 66 W 3 2810 3400 0 Blue 0
1 AM Wed 67 65 W 3 2793 3400 0 Blue 0
2 AM Wed 66 64 W 2 2777 3400 0 Blue 0
3 AM Wed 65 63 W 2 2760 3400 0 Blue 0
4 AM Wed 63 61 W 2 2726 3400 0 Blue 0
5 AM Wed 63 61 N 3 2726 3400 0 Blue 0
6 AM Wed 64 62 N 3 2743 3400 0 Blue 0
7 AM Wed 67 65 N 3 2793 3400 0 Blue 0
8 AM Wed 71 70 NE 2 2891 3400 0 Blue 0
9 AM Wed 75 76 NE 2 7067 4998 1598 Blue 6
10 AM Wed 79 81 NE 2 9005 7798 4398 Blue 11
11 AM Wed 82 86 E 6 9562 9252 5852 Blue 16
12 Noon Wed 84 89 E 6 9859 9541 6141 Blue 19
1 PM Wed 86 92 E 6 10949 9829 6429 Blue 22
2 PM Wed 86 92 S 7 10949 9829 6429 Blue 22
3 PM Wed 87 92 S 7 10949 9829 6429 Blue 22
4 PM Wed 87 90 S 7 10204 9637 6237 Blue 20
5 PM Wed 85 86 W 10 9562 9252 5852 Blue 16
6 PM Wed 82 82 W 10 9176 8488 5088 Blue 12
7 PM Wed 79 77 W 10 7281 5710 2310 Blue 7
8 PM Wed 75 73 W 10 5038 3400 0 Blue 3
9 PM Wed 72 70 W 10 2891 3400 0 Blue 0
10 PM Wed 69 67 W 10 2827 3400 0 Blue 0
11 PM Wed 67 65 W 5 2793 3400 0 Blue 0
12 Midnight Thu 66 64 W 5 2777 3400 0 Blue 0
1 AM Thu 65 63 W 5 2760 3400 0 Blue 0
2 AM Thu 64 62 W 5 2743 3400 0 Blue 0
3 AM Thu 63 61 W 5 2726 3400 0 Blue 0
4 AM Thu 62 60 W 5 2720 3400 0 Blue 0
5 AM Thu 62 60 S 3 2720 3400 0 Blue 0
6 AM Thu 63 61 S 3 2726 3400 0 Blue 0
7 AM Thu 66 64 S 3 2777 3400 0 Blue 0
8 AM Thu 70 69 S 3 2861 3400 0 Blue 0
9 AM Thu 74 75 S 3 6174 3400 0 Blue 5
10 AM Thu 79 82 S 3 9176 8488 5088 Blue 12
11 AM Thu 83 88 E 5 9755 9444 6044 Blue 18
12 Noon Thu 86 92 E 5 10949 9829 6429 Blue 22
1 PM Thu 87 94 E 5 11463 10489 7089 Blue 24
2 PM Thu 89 95 E 5 11763 10880 7480 Blue 25
3 PM Thu 90 95 E 5 11763 10880 7480 Blue 25
4 PM Thu 90 93 E 5 11207 10121 6721 Blue 23
5 PM Thu 89 90 W 5 10204 9637 6237 Blue 20
6 PM Thu 85 85 W 5 9465 9142 5742 Blue 15
7 PM Thu 81 79 W 5 8582 7037 3637 Blue 9
8 PM Thu 76 74 W 5 5778 3400 0 Blue 4
9 PM Thu 73 71 W 5 2960 3400 0 Blue 1
10 PM Thu 70 68 W 5 2844 3400 0 Blue 0
11 PM Thu 69 67 NW 5 2827 3400 0 Blue 0
12 Midnight Fri 69 67 NW 5 2827 3400 0 Blue 0
1 AM Fri 68 66 NW 5 2810 3400 0 Blue 0
2 AM Fri 68 66 NW 5 2810 3400 0 Blue 0
3 AM Fri 67 65 NW 5 2793 3400 0 Blue 0
4 AM Fri 66 64 NW 5 2777 3400 0 Blue 0
5 AM Fri 66 64 N 7 2777 3400 0 Blue 0
6 AM Fri 67 65 N 7 2793 3400 0 Blue 0
7 AM Fri 69 67 N 7 2827 3400 0 Blue 0
8 AM Fri 73 72 N 7 3250 3400 0 Blue 2
9 AM Fri 77 78 N 7 8055 6132 2732 Blue 8
10 AM Fri 82 85 N 7 9465 9142 5742 Blue 15
11 AM Fri 87 92 N 7 10949 9829 6429 Blue 22
12 Noon Fri 90 96 N 7 12265 11136 7736 Blue 26
1 PM Fri 92 99 N 7 13735 12111 8711 Blue 29
2 PM Fri 94 100 N 7 14221 12595 9195 Blue 30
3 PM Fri 95 100 N 7 14221 12595 9195 Blue 30
4 PM Fri 95 98 N 7 13229 11643 8243 Blue 28
5 PM Fri 93 94 W 6 11463 10489 7089 Blue 24
6 PM Fri 90 90 W 6 10204 9637 6237 Blue 20
7 PM Fri 85 83 W 6 9272 8797 5397 Blue 13
8 PM Fri 80 78 W 6 8055 6132 2732 Blue 8
9 PM Fri 77 75 W 6 6174 3400 0 Blue 5
10 PM Fri 75 73 W 6 5038 3400 0 Blue 3
11 PM Fri 73 71 NW 6 2960 3400 0 Blue 1
12 Midnight Sat 72 70 NW 6 2891 3400 0 Blue 0
1 AM Sat 71 69 NW 6 2861 3400 0 Blue 0
2 AM Sat 70 68 NW 6 2844 3400 0 Blue 0
3 AM Sat 69 67 NW 6 2827 3400 0 Blue 0
4 AM Sat 68 66 NW 6 2810 3400 0 Blue 0
5 AM Sat 68 66 N 6 2810 3400 0 Blue 0
6 AM Sat 69 67 N 6 2827 3400 0 Blue 0
7 AM Sat 71 69 N 6 2861 3400 0 Blue 0
8 AM Sat 75 74 N 6 5778 3400 0 Blue 4
9 AM Sat 79 80 N 6 8831 7250 3850 Blue 10
10 AM Sat 84 87 N 6 9659 9348 5948 Blue 17
11 AM Sat 89 94 N 10 11463 10489 7089 Blue 24
12 Noon Sat 92 98 N 10 13229 11643 8243 Blue 28
1 PM Sat 94 101 N 10 14579 13066 9666 Blue 31
2 PM Sat 96 102 N 10 14907 13526 10126 Blue 32
3 PM Sat 97 102 N 10 14907 13526 10126 Blue 32
4 PM Sat 97 100 N 10 14221 12595 9195 Blue 30
5 PM Sat 96 97 NW 9 12753 11390 7990 Blue 27
6 PM Sat 92 92 NW 9 10949 9829 6429 Blue 22
7 PM Sat 88 86 NW 9 9562 9252 5852 Blue 16
8 PM Sat 83 81 NW 9 9005 7798 4398 Blue 11
9 PM Sat 80 78 NW 9 8055 6132 2732 Blue 8
10 PM Sat 77 75 NW 9 6174 3400 0 Blue 5
11 PM Sat 75 73 N 7 5038 3400 0 Blue 3
12 Midnight Sun 74 72 N 7 3250 3400 0 Blue 2
1 AM Sun 73 71 N 7 2960 3400 0 Blue 1
2 AM Sun 72 70 N 7 2891 3400 0 Blue 0
3 AM Sun 71 69 N 7 2861 3400 0 Blue 0
4 AM Sun 70 68 N 7 2844 3400 0 Blue 0
5 AM Sun 70 68 N 7 2844 3400 0 Blue 0
6 AM Sun 71 69 N 7 2861 3400 0 Blue 0
7 AM Sun 73 71 N 7 2960 3400 0 Blue 1
8 AM Sun 75 74 N 7 5778 3400 0 Blue 4
9 AM Sun 79 80 N 7 8831 7250 3850 Blue 10
10 AM Sun 83 86 N 7 9562 9252 5852 Blue 16
11 AM Sun 87 92 NE 3 10949 9829 6429 Blue 22
12 Noon Sun 90 96 NE 3 12265 11136 7736 Blue 26
1 PM Sun 92 99 NE 3 13735 12111 8711 Blue 29
2 PM Sun 94 100 NE 3 14221 12595 9195 Blue 30
3 PM Sun 94 99 NE 3 13735 12111 8711 Blue 29
4 PM Sun 93 96 NE 3 12265 11136 7736 Blue 26
5 PM Sun 91 92 SW 7 10949 9829 6429 Blue 22
6 PM Sun 88 88 SW 7 9755 9444 6044 Blue 18
7 PM Sun 84 82 SW 7 9176 8488 5088 Blue 12
8 PM Sun 79 77 SW 7 7281 5710 2310 Blue 7
9 PM Sun 76 74 SW 7 5778 3400 0 Blue 4
10 PM Sun 72 70 SW 7 2891 3400 0 Blue 0
11 PM Sun 70 68 W 6 2844 3400 0 Blue 0
12 Midnight Mon 68 66 W 6 2810 3400 0 Blue 0
1 AM Mon 67 65 W 6 2793 3400 0 Blue 0
2 AM Mon 66 64 W 6 2777 3400 0 Blue 0
3 AM Mon 65 63 W 6 2760 3400 0 Blue 0
4 AM Mon 64 62 W 6 2743 3400 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