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

Station:

KOAK

Date/Time:

16 FEB 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)
4 AM Sat 36 34 W 12 2713 3400 0 Blue 0
5 AM Sat 36 34 W 12 2713 3400 0 Blue 0
6 AM Sat 35 33 W 12 2713 3400 0 Blue 0
7 AM Sat 35 33 W 13 2713 3400 0 Blue 0
8 AM Sat 36 34 W 13 2713 3400 0 Blue 0
9 AM Sat 38 36 W 13 2713 3400 0 Blue 0
10 AM Sat 39 37 W 13 3328 3400 0 Blue 0
11 AM Sat 40 38 W 13 3934 3400 0 Blue 1
12 Noon Sat 42 40 W 13 4842 3400 0 White 3
1 PM Sat 43 41 W 13 5058 3921 521 White 4
2 PM Sat 43 41 W 13 5058 3921 521 White 4
3 PM Sat 43 41 W 13 5058 3921 521 White 4
4 PM Sat 42 40 W 10 4842 3400 0 White 3
5 PM Sat 40 38 W 10 3934 3400 0 Blue 1
6 PM Sat 38 36 W 10 2713 3400 0 Blue 0
7 PM Sat 37 35 W 9 2713 3400 0 Blue 0
8 PM Sat 35 33 W 9 2713 3400 0 Blue 0
9 PM Sat 34 32 W 9 2713 3400 0 Blue 0
10 PM Sat 34 32 W 7 2713 3400 0 Blue 0
11 PM Sat 34 32 W 7 2713 3400 0 Blue 0
12 Midnight Sun 34 32 W 7 2713 3400 0 Blue 0
1 AM Sun 34 32 W 5 2713 3400 0 Blue 0
2 AM Sun 34 32 W 5 2713 3400 0 Blue 0
3 AM Sun 33 31 W 5 2713 3400 0 Blue 0
4 AM Sun 32 30 NW 5 2713 3400 0 Blue 0
5 AM Sun 31 29 NW 5 2713 3400 0 Blue 0
6 AM Sun 31 29 NW 5 2713 3400 0 Blue 0
7 AM Sun 31 29 NW 3 2713 3400 0 Blue 0
8 AM Sun 32 30 NW 3 2713 3400 0 Blue 0
9 AM Sun 34 32 NW 3 2713 3400 0 Blue 0
10 AM Sun 36 34 NE 5 2713 3400 0 Blue 0
11 AM Sun 38 37 NE 5 3328 3400 0 Blue 0
12 Noon Sun 39 38 NE 5 3934 3400 0 Blue 1
1 PM Sun 40 39 NE 5 4251 3400 0 Blue 2
2 PM Sun 40 39 NE 5 4251 3400 0 Blue 2
3 PM Sun 40 38 NE 5 3934 3400 0 Blue 1
4 PM Sun 39 37 N 7 3328 3400 0 Blue 0
5 PM Sun 38 36 N 7 2713 3400 0 Blue 0
6 PM Sun 36 34 N 7 2713 3400 0 Blue 0
7 PM Sun 35 33 N 7 2713 3400 0 Blue 0
8 PM Sun 34 32 N 7 2713 3400 0 Blue 0
9 PM Sun 34 32 N 7 2713 3400 0 Blue 0
10 PM Sun 33 31 N 9 2713 3400 0 Blue 0
11 PM Sun 33 31 N 9 2713 3400 0 Blue 0
12 Midnight Mon 32 30 N 9 2713 3400 0 Blue 0
1 AM Mon 32 30 N 9 2713 3400 0 Blue 0
2 AM Mon 31 29 N 9 2713 3400 0 Blue 0
3 AM Mon 31 29 N 9 2713 3400 0 Blue 0
4 AM Mon 30 28 N 9 2713 3400 0 Blue 0
5 AM Mon 30 28 N 9 2713 3400 0 Blue 0
6 AM Mon 30 28 N 9 2713 3400 0 Blue 0
7 AM Mon 31 29 N 9 2713 3400 0 Blue 0
8 AM Mon 34 32 N 9 2713 3400 0 Blue 0
9 AM Mon 37 36 N 9 2713 3400 0 Blue 0
10 AM Mon 40 40 N 9 4842 3400 0 White 3
11 AM Mon 43 43 N 9 5488 5088 1688 White 6
12 Noon Mon 45 46 N 9 6129 6129 2729 White 9
1 PM Mon 46 47 N 9 6341 6341 2941 White 10
2 PM Mon 47 47 N 9 6341 6341 2941 White 10
3 PM Mon 47 46 N 9 6129 6129 2729 White 9
4 PM Mon 46 44 N 9 5702 5702 2302 White 7
5 PM Mon 43 41 N 9 5058 3921 521 White 4
6 PM Mon 40 38 N 9 3934 3400 0 Blue 1
7 PM Mon 37 35 N 9 2713 3400 0 Blue 0
8 PM Mon 35 33 N 9 2713 3400 0 Blue 0
9 PM Mon 34 32 N 9 2713 3400 0 Blue 0
10 PM Mon 34 32 E 8 2713 3400 0 Blue 0
11 PM Mon 33 31 E 8 2713 3400 0 Blue 0
12 Midnight Tue 32 30 E 8 2713 3400 0 Blue 0
1 AM Tue 32 30 E 8 2713 3400 0 Blue 0
2 AM Tue 31 29 E 8 2713 3400 0 Blue 0
3 AM Tue 31 29 E 8 2713 3400 0 Blue 0
4 AM Tue 31 29 N 7 2713 3400 0 Blue 0
5 AM Tue 30 28 N 7 2713 3400 0 Blue 0
6 AM Tue 29 27 N 7 2713 3400 0 Blue 0
7 AM Tue 29 27 N 7 2713 3400 0 Blue 0
8 AM Tue 31 29 N 7 2713 3400 0 Blue 0
9 AM Tue 34 33 N 7 2713 3400 0 Blue 0
10 AM Tue 37 36 N 7 2713 3400 0 Blue 0
11 AM Tue 39 39 N 7 4251 3400 0 Blue 2
12 Noon Tue 42 43 N 7 5488 5088 1688 White 6
1 PM Tue 43 44 N 7 5702 5702 2302 White 7
2 PM Tue 45 45 N 7 5916 5916 2516 White 8
3 PM Tue 45 44 N 7 5702 5702 2302 White 7
4 PM Tue 44 42 NW 7 5273 4235 835 White 5
5 PM Tue 42 40 NW 7 4842 3400 0 White 3
6 PM Tue 40 38 NW 7 3934 3400 0 Blue 1
7 PM Tue 38 36 NW 7 2713 3400 0 Blue 0
8 PM Tue 37 35 NW 7 2713 3400 0 Blue 0
9 PM Tue 37 35 NW 7 2713 3400 0 Blue 0
10 PM Tue 37 35 NW 5 2713 3400 0 Blue 0
11 PM Tue 36 34 NW 5 2713 3400 0 Blue 0
12 Midnight Wed 35 33 NW 5 2713 3400 0 Blue 0
1 AM Wed 35 33 NW 5 2713 3400 0 Blue 0
2 AM Wed 35 33 NW 5 2713 3400 0 Blue 0
3 AM Wed 35 33 NW 5 2713 3400 0 Blue 0
4 AM Wed 35 33 N 6 2713 3400 0 Blue 0
5 AM Wed 34 32 N 6 2713 3400 0 Blue 0
6 AM Wed 32 30 N 6 2713 3400 0 Blue 0
7 AM Wed 32 30 N 6 2713 3400 0 Blue 0
8 AM Wed 33 31 N 6 2713 3400 0 Blue 0
9 AM Wed 36 34 N 6 2713 3400 0 Blue 0
10 AM Wed 38 37 NW 6 3328 3400 0 Blue 0
11 AM Wed 40 39 NW 6 4251 3400 0 Blue 2
12 Noon Wed 42 41 NW 6 5058 3921 521 White 4
1 PM Wed 43 42 NW 6 5273 4235 835 White 5
2 PM Wed 44 43 NW 6 5488 5088 1688 White 6
3 PM Wed 44 42 NW 6 5273 4235 835 White 5
4 PM Wed 43 41 W 8 5058 3921 521 White 4
5 PM Wed 41 39 W 8 4251 3400 0 Blue 2
6 PM Wed 38 36 W 8 2713 3400 0 Blue 0
7 PM Wed 37 35 W 8 2713 3400 0 Blue 0
8 PM Wed 36 34 W 8 2713 3400 0 Blue 0
9 PM Wed 35 33 W 8 2713 3400 0 Blue 0
10 PM Wed 35 33 NW 10 2713 3400 0 Blue 0
11 PM Wed 34 32 NW 10 2713 3400 0 Blue 0
12 Midnight Thu 34 32 NW 10 2713 3400 0 Blue 0
1 AM Thu 33 31 NW 10 2713 3400 0 Blue 0
2 AM Thu 33 31 NW 10 2713 3400 0 Blue 0
3 AM Thu 32 30 NW 10 2713 3400 0 Blue 0
4 AM Thu 31 29 NW 10 2713 3400 0 Blue 0
5 AM Thu 31 29 NW 10 2713 3400 0 Blue 0
6 AM Thu 30 28 NW 10 2713 3400 0 Blue 0
7 AM Thu 30 28 NW 10 2713 3400 0 Blue 0
8 AM Thu 32 30 NW 10 2713 3400 0 Blue 0
9 AM Thu 34 32 NW 10 2713 3400 0 Blue 0
10 AM Thu 36 35 N 13 2713 3400 0 Blue 0
11 AM Thu 38 37 N 13 3328 3400 0 Blue 0
12 Noon Thu 39 39 N 13 4251 3400 0 Blue 2
1 PM Thu 39 39 N 13 4251 3400 0 Blue 2
2 PM Thu 40 39 N 13 4251 3400 0 Blue 2
3 PM Thu 40 39 N 13 4251 3400 0 Blue 2
4 PM Thu 39 37 N 16 3328 3400 0 Blue 0
5 PM Thu 38 36 N 16 2713 3400 0 Blue 0
6 PM Thu 36 34 N 16 2713 3400 0 Blue 0
7 PM Thu 34 32 N 16 2713 3400 0 Blue 0
8 PM Thu 34 32 N 16 2713 3400 0 Blue 0
9 PM Thu 34 32 N 16 2713 3400 0 Blue 0
10 PM Thu 34 32 N 14 2713 3400 0 Blue 0
11 PM Thu 33 31 N 14 2713 3400 0 Blue 0
12 Midnight Fri 33 31 N 14 2713 3400 0 Blue 0
1 AM Fri 32 30 N 14 2713 3400 0 Blue 0
2 AM Fri 32 30 N 14 2713 3400 0 Blue 0
3 AM Fri 32 30 N 14 2713 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