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

Station:

KOAK

Date/Time:

25 NOV 2020

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)
4 AM Wed 42 40 NW 7 2710 3400 0 Blue 0
5 AM Wed 42 40 NW 7 2710 3400 0 Blue 0
6 AM Wed 40 38 NW 7 2710 3400 0 Blue 0
7 AM Wed 41 39 NW 7 2710 3400 0 Blue 0
8 AM Wed 46 44 NW 7 2710 3400 0 Blue 0
9 AM Wed 48 46 NW 7 3053 3400 0 Blue 0
10 AM Wed 50 49 N 8 3671 3400 0 Blue 3
11 AM Wed 51 50 N 8 3797 3416 16 Blue 3
12 Noon Wed 52 52 N 8 4049 3667 267 Blue 5
1 PM Wed 55 54 NW 9 4471 3918 518 Blue 7
2 PM Wed 55 54 NW 9 4471 3918 518 Blue 7
3 PM Wed 54 52 NW 9 4049 3667 267 Blue 5
4 PM Wed 47 45 NW 8 2710 3400 0 Blue 0
5 PM Wed 42 40 NW 8 2710 3400 0 Blue 0
6 PM Wed 41 39 NW 8 2710 3400 0 Blue 0
7 PM Wed 39 37 NW 8 2710 3400 0 Blue 0
8 PM Wed 39 37 NW 8 2710 3400 0 Blue 0
9 PM Wed 39 37 NW 8 2710 3400 0 Blue 0
10 PM Wed 38 36 N 8 2710 3400 0 Blue 0
11 PM Wed 39 37 N 8 2710 3400 0 Blue 0
12 Midnight Thu 39 37 N 8 2710 3400 0 Blue 0
1 AM Thu 39 37 N 9 2710 3400 0 Blue 0
2 AM Thu 39 37 N 9 2710 3400 0 Blue 0
3 AM Thu 38 36 N 9 2710 3400 0 Blue 0
4 AM Thu 38 36 N 12 2710 3400 0 Blue 0
5 AM Thu 38 36 N 12 2710 3400 0 Blue 0
6 AM Thu 38 36 N 12 2710 3400 0 Blue 0
7 AM Thu 42 40 N 13 2710 3400 0 Blue 0
8 AM Thu 44 42 N 13 2710 3400 0 Blue 0
9 AM Thu 48 46 N 13 3053 3400 0 Blue 0
10 AM Thu 49 48 N 14 3545 3400 0 Blue 2
11 AM Thu 52 51 N 14 3923 3542 142 Blue 4
12 Noon Thu 55 55 N 14 4877 4044 644 Blue 8
1 PM Thu 57 57 N 13 5218 4436 1036 Blue 10
2 PM Thu 56 55 N 13 4877 4044 644 Blue 8
3 PM Thu 54 52 N 13 4049 3667 267 Blue 5
4 PM Thu 50 48 N 10 3545 3400 0 Blue 2
5 PM Thu 47 45 N 10 2710 3400 0 Blue 0
6 PM Thu 45 43 N 10 2710 3400 0 Blue 0
7 PM Thu 44 42 N 10 2710 3400 0 Blue 0
8 PM Thu 43 41 N 10 2710 3400 0 Blue 0
9 PM Thu 42 40 N 10 2710 3400 0 Blue 0
10 PM Thu 42 40 N 10 2710 3400 0 Blue 0
11 PM Thu 42 40 N 10 2710 3400 0 Blue 0
12 Midnight Fri 42 40 N 10 2710 3400 0 Blue 0
1 AM Fri 42 40 N 10 2710 3400 0 Blue 0
2 AM Fri 42 40 N 10 2710 3400 0 Blue 0
3 AM Fri 41 39 N 10 2710 3400 0 Blue 0
4 AM Fri 41 39 N 10 2710 3400 0 Blue 0
5 AM Fri 41 39 N 10 2710 3400 0 Blue 0
6 AM Fri 42 40 N 10 2710 3400 0 Blue 0
7 AM Fri 44 42 N 7 2710 3400 0 Blue 0
8 AM Fri 46 44 N 7 2710 3400 0 Blue 0
9 AM Fri 50 48 N 7 3545 3400 0 Blue 2
10 AM Fri 54 53 N 7 4175 3793 393 Blue 6
11 AM Fri 57 57 N 7 5218 4436 1036 Blue 10
12 Noon Fri 60 60 N 7 5730 5199 1799 Blue 13
1 PM Fri 61 61 NE 8 5848 5429 2029 Blue 14
2 PM Fri 59 58 NE 8 5445 4867 1467 Blue 11
3 PM Fri 56 54 NE 8 4471 3918 518 Blue 7
4 PM Fri 53 51 NE 6 3923 3542 142 Blue 4
5 PM Fri 49 47 NE 6 3419 3400 0 Blue 1
6 PM Fri 46 44 NE 6 2710 3400 0 Blue 0
7 PM Fri 44 42 N 5 2710 3400 0 Blue 0
8 PM Fri 43 41 N 5 2710 3400 0 Blue 0
9 PM Fri 42 40 N 5 2710 3400 0 Blue 0
10 PM Fri 42 40 N 3 2710 3400 0 Blue 0
11 PM Fri 42 40 N 3 2710 3400 0 Blue 0
12 Midnight Sat 43 41 N 3 2710 3400 0 Blue 0
1 AM Sat 43 41 N 3 2710 3400 0 Blue 0
2 AM Sat 42 40 N 3 2710 3400 0 Blue 0
3 AM Sat 41 39 N 3 2710 3400 0 Blue 0
4 AM Sat 39 37 N 5 2710 3400 0 Blue 0
5 AM Sat 39 37 N 5 2710 3400 0 Blue 0
6 AM Sat 40 38 N 5 2710 3400 0 Blue 0
7 AM Sat 42 40 N 6 2710 3400 0 Blue 0
8 AM Sat 45 43 N 6 2710 3400 0 Blue 0
9 AM Sat 49 47 N 6 3419 3400 0 Blue 1
10 AM Sat 53 52 NE 6 4049 3667 267 Blue 5
11 AM Sat 57 56 NE 6 5022 4169 769 Blue 9
12 Noon Sat 60 60 NE 6 5730 5199 1799 Blue 13
1 PM Sat 61 60 NE 6 5730 5199 1799 Blue 13
2 PM Sat 60 59 NE 6 5612 5009 1609 Blue 12
3 PM Sat 58 56 NE 6 5022 4169 769 Blue 9
4 PM Sat 54 52 E 5 4049 3667 267 Blue 5
5 PM Sat 51 49 E 5 3671 3400 0 Blue 3
6 PM Sat 48 46 E 5 3053 3400 0 Blue 0
7 PM Sat 45 43 NW 5 2710 3400 0 Blue 0
8 PM Sat 43 41 NW 5 2710 3400 0 Blue 0
9 PM Sat 42 40 NW 5 2710 3400 0 Blue 0
10 PM Sat 42 40 NW 6 2710 3400 0 Blue 0
11 PM Sat 43 41 NW 6 2710 3400 0 Blue 0
12 Midnight Sun 44 42 NW 6 2710 3400 0 Blue 0
1 AM Sun 44 42 NW 6 2710 3400 0 Blue 0
2 AM Sun 43 41 NW 6 2710 3400 0 Blue 0
3 AM Sun 42 40 NW 6 2710 3400 0 Blue 0
4 AM Sun 41 39 NW 6 2710 3400 0 Blue 0
5 AM Sun 41 39 NW 6 2710 3400 0 Blue 0
6 AM Sun 42 40 NW 6 2710 3400 0 Blue 0
7 AM Sun 44 42 N 6 2710 3400 0 Blue 0
8 AM Sun 46 44 N 6 2710 3400 0 Blue 0
9 AM Sun 49 47 N 6 3419 3400 0 Blue 1
10 AM Sun 53 52 N 6 4049 3667 267 Blue 5
11 AM Sun 57 56 N 6 5022 4169 769 Blue 9
12 Noon Sun 60 59 N 6 5612 5009 1609 Blue 12
1 PM Sun 61 60 E 7 5730 5199 1799 Blue 13
2 PM Sun 60 59 E 7 5612 5009 1609 Blue 12
3 PM Sun 57 55 E 7 4877 4044 644 Blue 8
4 PM Sun 54 52 E 6 4049 3667 267 Blue 5
5 PM Sun 50 48 E 6 3545 3400 0 Blue 2
6 PM Sun 48 46 E 6 3053 3400 0 Blue 0
7 PM Sun 46 44 NW 6 2710 3400 0 Blue 0
8 PM Sun 45 43 NW 6 2710 3400 0 Blue 0
9 PM Sun 44 42 NW 6 2710 3400 0 Blue 0
10 PM Sun 44 42 NW 6 2710 3400 0 Blue 0
11 PM Sun 44 42 NW 6 2710 3400 0 Blue 0
12 Midnight Mon 44 42 NW 6 2710 3400 0 Blue 0
1 AM Mon 44 42 NW 6 2710 3400 0 Blue 0
2 AM Mon 43 41 NW 6 2710 3400 0 Blue 0
3 AM Mon 42 40 NW 6 2710 3400 0 Blue 0
4 AM Mon 41 39 NW 6 2710 3400 0 Blue 0
5 AM Mon 41 39 NW 6 2710 3400 0 Blue 0
6 AM Mon 42 40 NW 6 2710 3400 0 Blue 0
7 AM Mon 43 41 NW 7 2710 3400 0 Blue 0
8 AM Mon 46 44 NW 7 2710 3400 0 Blue 0
9 AM Mon 48 46 NW 7 3053 3400 0 Blue 0
10 AM Mon 51 49 NW 7 3671 3400 0 Blue 3
11 AM Mon 54 53 NW 7 4175 3793 393 Blue 6
12 Noon Mon 56 55 NW 7 4877 4044 644 Blue 8
1 PM Mon 57 56 W 8 5022 4169 769 Blue 9
2 PM Mon 56 54 W 8 4471 3918 518 Blue 7
3 PM Mon 53 51 W 8 3923 3542 142 Blue 4
4 PM Mon 51 49 W 7 3671 3400 0 Blue 3
5 PM Mon 49 47 W 7 3419 3400 0 Blue 1
6 PM Mon 47 45 W 7 2710 3400 0 Blue 0
7 PM Mon 46 44 NW 6 2710 3400 0 Blue 0
8 PM Mon 45 43 NW 6 2710 3400 0 Blue 0
9 PM Mon 44 42 NW 6 2710 3400 0 Blue 0
10 PM Mon 43 41 N 7 2710 3400 0 Blue 0
11 PM Mon 43 41 N 7 2710 3400 0 Blue 0
12 Midnight Tue 44 42 N 7 2710 3400 0 Blue 0
1 AM Tue 43 41 N 7 2710 3400 0 Blue 0
2 AM Tue 43 41 N 7 2710 3400 0 Blue 0
3 AM Tue 42 40 N 7 2710 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