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

Station:

KOAK

Date/Time:

15 OCT 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 Mon 53 51 N 12 2687 3400 0 Blue 0
6 AM Mon 52 50 N 12 2687 3400 0 Blue 0
7 AM Mon 52 50 N 12 2687 3400 0 Blue 0
8 AM Mon 53 51 N 9 2687 3400 0 Blue 0
9 AM Mon 57 55 N 9 2687 3400 0 Blue 0
10 AM Mon 61 60 N 9 2687 3400 0 Blue 0
11 AM Mon 65 66 NE 9 4851 3958 558 Blue 4
12 Noon Mon 68 70 NE 9 5003 4886 1486 Blue 8
1 PM Mon 70 72 NE 9 5595 4962 1562 Blue 10
2 PM Mon 71 73 NE 9 6011 5000 1600 Blue 11
3 PM Mon 72 73 NE 9 6011 5000 1600 Blue 11
4 PM Mon 72 72 NE 9 5595 4962 1562 Blue 10
5 PM Mon 70 68 NE 6 4927 4810 1410 Blue 6
6 PM Mon 66 64 NE 6 4564 3400 0 Blue 2
7 PM Mon 62 60 NE 6 2687 3400 0 Blue 0
8 PM Mon 58 56 N 7 2687 3400 0 Blue 0
9 PM Mon 57 55 N 7 2687 3400 0 Blue 0
10 PM Mon 56 54 N 7 2687 3400 0 Blue 0
11 PM Mon 56 54 NW 7 2687 3400 0 Blue 0
12 Midnight Tue 56 54 NW 7 2687 3400 0 Blue 0
1 AM Tue 55 53 NW 7 2687 3400 0 Blue 0
2 AM Tue 55 53 N 7 2687 3400 0 Blue 0
3 AM Tue 54 52 N 7 2687 3400 0 Blue 0
4 AM Tue 54 52 N 7 2687 3400 0 Blue 0
5 AM Tue 54 52 N 7 2687 3400 0 Blue 0
6 AM Tue 53 51 N 7 2687 3400 0 Blue 0
7 AM Tue 53 51 N 7 2687 3400 0 Blue 0
8 AM Tue 55 53 N 7 2687 3400 0 Blue 0
9 AM Tue 59 57 N 7 2687 3400 0 Blue 0
10 AM Tue 64 63 N 7 3981 3400 0 Blue 1
11 AM Tue 68 69 N 8 4965 4848 1448 Blue 7
12 Noon Tue 72 73 N 8 6011 5000 1600 Blue 11
1 PM Tue 74 76 N 8 6754 5968 2568 Blue 14
2 PM Tue 75 77 NE 8 6963 6311 2911 Blue 15
3 PM Tue 76 77 NE 8 6963 6311 2911 Blue 15
4 PM Tue 76 76 NE 8 6754 5968 2568 Blue 14
5 PM Tue 74 72 E 6 5595 4962 1562 Blue 10
6 PM Tue 70 68 E 6 4927 4810 1410 Blue 6
7 PM Tue 65 63 E 6 3981 3400 0 Blue 1
8 PM Tue 62 60 E 6 2687 3400 0 Blue 0
9 PM Tue 60 58 E 6 2687 3400 0 Blue 0
10 PM Tue 60 58 E 6 2687 3400 0 Blue 0
11 PM Tue 60 58 N 5 2687 3400 0 Blue 0
12 Midnight Wed 59 57 N 5 2687 3400 0 Blue 0
1 AM Wed 58 56 N 5 2687 3400 0 Blue 0
2 AM Wed 57 55 N 5 2687 3400 0 Blue 0
3 AM Wed 57 55 N 5 2687 3400 0 Blue 0
4 AM Wed 56 54 N 5 2687 3400 0 Blue 0
5 AM Wed 55 53 N 5 2687 3400 0 Blue 0
6 AM Wed 54 52 N 5 2687 3400 0 Blue 0
7 AM Wed 54 52 N 5 2687 3400 0 Blue 0
8 AM Wed 55 53 N 5 2687 3400 0 Blue 0
9 AM Wed 59 57 N 5 2687 3400 0 Blue 0
10 AM Wed 63 62 N 5 3377 3400 0 Blue 0
11 AM Wed 68 69 NE 5 4965 4848 1448 Blue 7
12 Noon Wed 71 73 NE 5 6011 5000 1600 Blue 11
1 PM Wed 73 75 NE 5 6545 5557 2157 Blue 13
2 PM Wed 74 76 NE 5 6754 5968 2568 Blue 14
3 PM Wed 74 75 NE 5 6545 5557 2157 Blue 13
4 PM Wed 73 73 NE 5 6011 5000 1600 Blue 11
5 PM Wed 71 69 S 2 4965 4848 1448 Blue 7
6 PM Wed 67 65 S 2 4813 3400 0 Blue 3
7 PM Wed 62 60 S 2 2687 3400 0 Blue 0
8 PM Wed 59 57 S 2 2687 3400 0 Blue 0
9 PM Wed 57 55 S 2 2687 3400 0 Blue 0
10 PM Wed 57 55 S 2 2687 3400 0 Blue 0
11 PM Wed 57 55 N 2 2687 3400 0 Blue 0
12 Midnight Thu 57 55 N 2 2687 3400 0 Blue 0
1 AM Thu 56 54 N 2 2687 3400 0 Blue 0
2 AM Thu 55 53 N 2 2687 3400 0 Blue 0
3 AM Thu 54 52 N 2 2687 3400 0 Blue 0
4 AM Thu 53 51 N 2 2687 3400 0 Blue 0
5 AM Thu 53 51 N 3 2687 3400 0 Blue 0
6 AM Thu 54 52 N 3 2687 3400 0 Blue 0
7 AM Thu 56 54 N 3 2687 3400 0 Blue 0
8 AM Thu 59 57 N 3 2687 3400 0 Blue 0
9 AM Thu 62 60 N 3 2687 3400 0 Blue 0
10 AM Thu 66 65 N 3 4813 3400 0 Blue 3
11 AM Thu 69 70 NE 2 5003 4886 1486 Blue 8
12 Noon Thu 71 73 NE 2 6011 5000 1600 Blue 11
1 PM Thu 73 75 NE 2 6545 5557 2157 Blue 13
2 PM Thu 74 76 NE 2 6754 5968 2568 Blue 14
3 PM Thu 75 76 NE 2 6754 5968 2568 Blue 14
4 PM Thu 75 75 NE 2 6545 5557 2157 Blue 13
5 PM Thu 74 72 W 2 5595 4962 1562 Blue 10
6 PM Thu 72 70 W 2 5003 4886 1486 Blue 8
7 PM Thu 70 68 W 2 4927 4810 1410 Blue 6
8 PM Thu 68 66 W 2 4851 3958 558 Blue 4
9 PM Thu 65 63 W 2 3981 3400 0 Blue 1
10 PM Thu 63 61 W 2 2687 3400 0 Blue 0
11 PM Thu 60 58 N 3 2687 3400 0 Blue 0
12 Midnight Fri 58 56 N 3 2687 3400 0 Blue 0
1 AM Fri 57 55 N 3 2687 3400 0 Blue 0
2 AM Fri 56 54 N 3 2687 3400 0 Blue 0
3 AM Fri 56 54 N 3 2687 3400 0 Blue 0
4 AM Fri 56 54 N 3 2687 3400 0 Blue 0
5 AM Fri 58 56 N 3 2687 3400 0 Blue 0
6 AM Fri 59 57 N 3 2687 3400 0 Blue 0
7 AM Fri 62 60 N 3 2687 3400 0 Blue 0
8 AM Fri 65 63 N 3 3981 3400 0 Blue 1
9 AM Fri 68 66 N 3 4851 3958 558 Blue 4
10 AM Fri 70 69 N 3 4965 4848 1448 Blue 7
11 AM Fri 73 74 N 3 6335 5139 1739 Blue 12
12 Noon Fri 75 76 N 3 6754 5968 2568 Blue 14
1 PM Fri 77 79 N 3 7378 6727 3327 Blue 17
2 PM Fri 78 80 N 3 7572 6934 3534 Blue 18
3 PM Fri 78 79 N 3 7378 6727 3327 Blue 17
4 PM Fri 78 78 N 3 7171 6519 3119 Blue 16
5 PM Fri 77 75 NE 2 6545 5557 2157 Blue 13
6 PM Fri 75 73 NE 2 6011 5000 1600 Blue 11
7 PM Fri 73 71 NE 2 5172 4924 1524 Blue 9
8 PM Fri 70 68 NE 2 4927 4810 1410 Blue 6
9 PM Fri 68 66 NE 2 4851 3958 558 Blue 4
10 PM Fri 65 63 NE 2 3981 3400 0 Blue 1
11 PM Fri 62 60 N 3 2687 3400 0 Blue 0
12 Midnight Sat 60 58 N 3 2687 3400 0 Blue 0
1 AM Sat 59 57 N 3 2687 3400 0 Blue 0
2 AM Sat 57 55 N 3 2687 3400 0 Blue 0
3 AM Sat 57 55 N 3 2687 3400 0 Blue 0
4 AM Sat 57 55 N 3 2687 3400 0 Blue 0
5 AM Sat 58 56 N 3 2687 3400 0 Blue 0
6 AM Sat 60 58 N 3 2687 3400 0 Blue 0
7 AM Sat 62 60 N 3 2687 3400 0 Blue 0
8 AM Sat 64 62 N 3 3377 3400 0 Blue 0
9 AM Sat 67 65 N 3 4813 3400 0 Blue 3
10 AM Sat 70 69 N 3 4965 4848 1448 Blue 7
11 AM Sat 72 73 NE 3 6011 5000 1600 Blue 11
12 Noon Sat 74 75 NE 3 6545 5557 2157 Blue 13
1 PM Sat 76 78 NE 3 7171 6519 3119 Blue 16
2 PM Sat 77 79 NE 3 7378 6727 3327 Blue 17
3 PM Sat 77 78 NE 3 7171 6519 3119 Blue 16
4 PM Sat 77 77 NE 3 6963 6311 2911 Blue 15
5 PM Sat 76 74 E 2 6335 5139 1739 Blue 12
6 PM Sat 74 72 E 2 5595 4962 1562 Blue 10
7 PM Sat 72 70 E 2 5003 4886 1486 Blue 8
8 PM Sat 69 67 E 2 4889 4531 1131 Blue 5
9 PM Sat 66 64 E 2 4564 3400 0 Blue 2
10 PM Sat 63 61 E 2 2687 3400 0 Blue 0
11 PM Sat 61 59 N 2 2687 3400 0 Blue 0
12 Midnight Sun 59 57 N 2 2687 3400 0 Blue 0
1 AM Sun 57 55 N 2 2687 3400 0 Blue 0
2 AM Sun 56 54 N 2 2687 3400 0 Blue 0
3 AM Sun 56 54 N 2 2687 3400 0 Blue 0
4 AM Sun 56 54 N 2 2687 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