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

Station:

KOAK

Date/Time:

20 OCT 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 Sun 51 49 NW 5 2690 3400 0 Blue 0
6 AM Sun 52 50 NW 5 2690 3400 0 Blue 0
7 AM Sun 50 48 NW 5 2690 3400 0 Blue 0
8 AM Sun 53 51 NW 5 2690 3400 0 Blue 0
9 AM Sun 58 56 NW 5 2690 3400 0 Blue 0
10 AM Sun 60 59 NW 5 3452 3400 0 Blue 0
11 AM Sun 62 62 NW 5 5142 3445 45 Blue 3
12 Noon Sun 65 66 NW 5 6393 5443 2043 Blue 7
1 PM Sun 65 66 NW 5 6393 5443 2043 Blue 7
2 PM Sun 66 67 NW 5 6693 5755 2355 Blue 8
3 PM Sun 68 68 NW 5 7142 6057 2657 Blue 9
4 PM Sun 67 66 NW 5 6393 5443 2043 Blue 7
5 PM Sun 66 64 NW 5 5785 4832 1432 Blue 5
6 PM Sun 60 58 NW 5 3147 3400 0 Blue 0
7 PM Sun 58 56 NW 5 2690 3400 0 Blue 0
8 PM Sun 58 56 NW 5 2690 3400 0 Blue 0
9 PM Sun 57 55 NW 5 2690 3400 0 Blue 0
10 PM Sun 57 55 NW 5 2690 3400 0 Blue 0
11 PM Sun 57 55 NW 5 2690 3400 0 Blue 0
12 Midnight Mon 57 55 NW 5 2690 3400 0 Blue 0
1 AM Mon 57 55 NW 5 2690 3400 0 Blue 0
2 AM Mon 56 54 NW 5 2690 3400 0 Blue 0
3 AM Mon 57 55 NW 5 2690 3400 0 Blue 0
4 AM Mon 56 54 NW 5 2690 3400 0 Blue 0
5 AM Mon 56 54 N 5 2690 3400 0 Blue 0
6 AM Mon 56 54 N 5 2690 3400 0 Blue 0
7 AM Mon 55 53 N 5 2690 3400 0 Blue 0
8 AM Mon 59 57 N 6 2839 3400 0 Blue 0
9 AM Mon 65 63 N 6 5471 4447 1047 Blue 4
10 AM Mon 67 66 N 6 6393 5443 2043 Blue 7
11 AM Mon 71 71 N 6 7638 7116 3716 Blue 12
12 Noon Mon 73 74 N 6 8132 7612 4212 Blue 15
1 PM Mon 75 76 N 6 8844 7939 4539 Blue 17
2 PM Mon 77 78 N 7 9578 8400 5000 Blue 19
3 PM Mon 78 78 N 7 9578 8400 5000 Blue 19
4 PM Mon 78 77 N 7 9213 8103 4703 Blue 18
5 PM Mon 76 74 N 7 8132 7612 4212 Blue 15
6 PM Mon 72 70 N 7 7473 6655 3255 Blue 11
7 PM Mon 67 65 N 7 6090 5117 1717 Blue 6
8 PM Mon 64 62 N 7 5142 3445 45 Blue 3
9 PM Mon 62 60 N 7 4472 3400 0 Blue 1
10 PM Mon 62 60 N 7 4472 3400 0 Blue 1
11 PM Mon 63 61 N 7 4855 3400 0 Blue 2
12 Midnight Tue 62 60 N 7 4472 3400 0 Blue 1
1 AM Tue 61 59 N 7 3452 3400 0 Blue 0
2 AM Tue 61 59 N 7 3452 3400 0 Blue 0
3 AM Tue 60 58 N 7 3147 3400 0 Blue 0
4 AM Tue 60 58 N 7 3147 3400 0 Blue 0
5 AM Tue 60 58 N 7 3147 3400 0 Blue 0
6 AM Tue 59 57 N 7 2839 3400 0 Blue 0
7 AM Tue 59 57 N 7 2839 3400 0 Blue 0
8 AM Tue 60 58 N 7 3147 3400 0 Blue 0
9 AM Tue 63 61 N 7 4855 3400 0 Blue 2
10 AM Tue 68 67 N 7 6693 5755 2355 Blue 8
11 AM Tue 71 71 N 6 7638 7116 3716 Blue 12
12 Noon Tue 74 75 N 6 8471 7776 4376 Blue 16
1 PM Tue 76 78 N 6 9578 8400 5000 Blue 19
2 PM Tue 76 77 N 6 9213 8103 4703 Blue 18
3 PM Tue 77 77 N 6 9213 8103 4703 Blue 18
4 PM Tue 77 76 N 6 8844 7939 4539 Blue 17
5 PM Tue 75 73 N 6 7968 7447 4047 Blue 14
6 PM Tue 71 69 N 6 7308 6357 2957 Blue 10
7 PM Tue 67 65 N 6 6090 5117 1717 Blue 6
8 PM Tue 64 62 N 6 5142 3445 45 Blue 3
9 PM Tue 62 60 N 6 4472 3400 0 Blue 1
10 PM Tue 63 61 N 6 4855 3400 0 Blue 2
11 PM Tue 63 61 N 8 4855 3400 0 Blue 2
12 Midnight Wed 63 61 N 8 4855 3400 0 Blue 2
1 AM Wed 62 60 N 8 4472 3400 0 Blue 1
2 AM Wed 61 59 N 8 3452 3400 0 Blue 0
3 AM Wed 61 59 N 8 3452 3400 0 Blue 0
4 AM Wed 61 59 N 8 3452 3400 0 Blue 0
5 AM Wed 60 58 N 8 3147 3400 0 Blue 0
6 AM Wed 60 58 N 8 3147 3400 0 Blue 0
7 AM Wed 60 58 N 8 3147 3400 0 Blue 0
8 AM Wed 61 59 N 8 3452 3400 0 Blue 0
9 AM Wed 63 61 N 8 4855 3400 0 Blue 2
10 AM Wed 66 65 N 8 6090 5117 1717 Blue 6
11 AM Wed 69 69 N 10 7308 6357 2957 Blue 10
12 Noon Wed 71 72 N 10 7803 7283 3883 Blue 13
1 PM Wed 73 74 N 10 8132 7612 4212 Blue 15
2 PM Wed 74 75 N 10 8471 7776 4376 Blue 16
3 PM Wed 74 74 N 10 8132 7612 4212 Blue 15
4 PM Wed 74 73 N 10 7968 7447 4047 Blue 14
5 PM Wed 72 70 N 12 7473 6655 3255 Blue 11
6 PM Wed 69 67 N 12 6693 5755 2355 Blue 8
7 PM Wed 65 63 N 12 5471 4447 1047 Blue 4
8 PM Wed 63 61 N 12 4855 3400 0 Blue 2
9 PM Wed 62 60 N 12 4472 3400 0 Blue 1
10 PM Wed 62 60 N 12 4472 3400 0 Blue 1
11 PM Wed 62 60 NE 12 4472 3400 0 Blue 1
12 Midnight Thu 61 59 NE 12 3452 3400 0 Blue 0
1 AM Thu 61 59 NE 12 3452 3400 0 Blue 0
2 AM Thu 60 58 NE 12 3147 3400 0 Blue 0
3 AM Thu 59 57 NE 12 2839 3400 0 Blue 0
4 AM Thu 59 57 NE 12 2839 3400 0 Blue 0
5 AM Thu 58 56 N 12 2690 3400 0 Blue 0
6 AM Thu 58 56 N 12 2690 3400 0 Blue 0
7 AM Thu 58 56 N 12 2690 3400 0 Blue 0
8 AM Thu 60 58 N 12 3147 3400 0 Blue 0
9 AM Thu 64 62 N 12 5142 3445 45 Blue 3
10 AM Thu 68 67 N 12 6693 5755 2355 Blue 8
11 AM Thu 73 73 NE 10 7968 7447 4047 Blue 14
12 Noon Thu 76 77 NE 10 9213 8103 4703 Blue 18
1 PM Thu 79 80 NE 10 10323 9136 5736 Blue 21
2 PM Thu 81 82 NE 10 10796 9853 6453 Blue 23
3 PM Thu 82 82 NE 10 10796 9853 6453 Blue 23
4 PM Thu 82 81 NE 10 10597 9496 6096 Blue 22
5 PM Thu 79 77 N 8 9213 8103 4703 Blue 18
6 PM Thu 74 72 N 8 7803 7283 3883 Blue 13
7 PM Thu 68 66 N 8 6393 5443 2043 Blue 7
8 PM Thu 63 61 N 8 4855 3400 0 Blue 2
9 PM Thu 61 59 N 8 3452 3400 0 Blue 0
10 PM Thu 61 59 N 8 3452 3400 0 Blue 0
11 PM Thu 61 59 NE 6 3452 3400 0 Blue 0
12 Midnight Fri 61 59 NE 6 3452 3400 0 Blue 0
1 AM Fri 60 58 NE 6 3147 3400 0 Blue 0
2 AM Fri 59 57 NE 6 2839 3400 0 Blue 0
3 AM Fri 58 56 NE 6 2690 3400 0 Blue 0
4 AM Fri 57 55 NE 6 2690 3400 0 Blue 0
5 AM Fri 56 54 N 3 2690 3400 0 Blue 0
6 AM Fri 56 54 N 3 2690 3400 0 Blue 0
7 AM Fri 57 55 N 3 2690 3400 0 Blue 0
8 AM Fri 59 57 N 3 2839 3400 0 Blue 0
9 AM Fri 63 61 N 3 4855 3400 0 Blue 2
10 AM Fri 69 68 N 3 7142 6057 2657 Blue 9
11 AM Fri 74 74 E 5 8132 7612 4212 Blue 15
12 Noon Fri 78 79 E 5 9937 8770 5370 Blue 20
1 PM Fri 81 83 E 5 11021 10205 6805 Blue 24
2 PM Fri 82 83 E 5 11021 10205 6805 Blue 24
3 PM Fri 83 83 E 5 11021 10205 6805 Blue 24
4 PM Fri 82 81 E 5 10597 9496 6096 Blue 22
5 PM Fri 80 78 W 6 9578 8400 5000 Blue 19
6 PM Fri 75 73 W 6 7968 7447 4047 Blue 14
7 PM Fri 69 67 W 6 6693 5755 2355 Blue 8
8 PM Fri 64 62 W 6 5142 3445 45 Blue 3
9 PM Fri 62 60 W 6 4472 3400 0 Blue 1
10 PM Fri 61 59 W 6 3452 3400 0 Blue 0
11 PM Fri 62 60 NW 6 4472 3400 0 Blue 1
12 Midnight Sat 61 59 NW 6 3452 3400 0 Blue 0
1 AM Sat 60 58 NW 6 3147 3400 0 Blue 0
2 AM Sat 59 57 NW 6 2839 3400 0 Blue 0
3 AM Sat 58 56 NW 6 2690 3400 0 Blue 0
4 AM Sat 57 55 NW 6 2690 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 [email protected]