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

Station:

KOAK

Date/Time:

21 NOV 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 Thu 49 47 N 7 2392 3400 0 Blue 0
5 AM Thu 48 46 N 7 2392 3400 0 Blue 0
6 AM Thu 49 47 N 7 2392 3400 0 Blue 0
7 AM Thu 47 45 N 6 2392 3400 0 Blue 0
8 AM Thu 49 47 N 6 2392 3400 0 Blue 0
9 AM Thu 52 50 N 6 3013 3400 0 Blue 0
10 AM Thu 52 51 NE 5 3196 3400 0 Blue 1
11 AM Thu 53 53 NE 5 3560 3400 0 Blue 3
12 Noon Thu 55 55 NE 5 4919 3400 0 Blue 5
1 PM Thu 56 56 NE 6 5436 3555 155 Blue 6
2 PM Thu 57 56 NE 6 5436 3555 155 Blue 6
3 PM Thu 56 54 NE 6 4232 3400 0 Blue 4
4 PM Thu 52 50 E 5 3013 3400 0 Blue 0
5 PM Thu 48 46 E 5 2392 3400 0 Blue 0
6 PM Thu 48 46 E 5 2392 3400 0 Blue 0
7 PM Thu 47 45 E 3 2392 3400 0 Blue 0
8 PM Thu 46 44 E 3 2392 3400 0 Blue 0
9 PM Thu 46 44 E 3 2392 3400 0 Blue 0
10 PM Thu 46 44 N 3 2392 3400 0 Blue 0
11 PM Thu 46 44 N 3 2392 3400 0 Blue 0
12 Midnight Fri 46 44 N 3 2392 3400 0 Blue 0
1 AM Fri 46 44 N 3 2392 3400 0 Blue 0
2 AM Fri 45 43 N 3 2392 3400 0 Blue 0
3 AM Fri 45 43 N 3 2392 3400 0 Blue 0
4 AM Fri 45 43 NW 3 2392 3400 0 Blue 0
5 AM Fri 45 43 NW 3 2392 3400 0 Blue 0
6 AM Fri 45 43 NW 3 2392 3400 0 Blue 0
7 AM Fri 45 43 N 3 2392 3400 0 Blue 0
8 AM Fri 48 46 N 3 2392 3400 0 Blue 0
9 AM Fri 51 49 N 3 2535 3400 0 Blue 0
10 AM Fri 54 53 NE 3 3560 3400 0 Blue 3
11 AM Fri 56 56 NE 3 5436 3555 155 Blue 6
12 Noon Fri 58 58 NE 3 6428 4882 1482 Blue 8
1 PM Fri 59 59 E 5 6905 5391 1991 Blue 9
2 PM Fri 59 58 E 5 6428 4882 1482 Blue 8
3 PM Fri 58 56 E 5 5436 3555 155 Blue 6
4 PM Fri 56 54 NW 2 4232 3400 0 Blue 4
5 PM Fri 53 51 NW 2 3196 3400 0 Blue 1
6 PM Fri 51 49 NW 2 2535 3400 0 Blue 0
7 PM Fri 49 47 NW 2 2392 3400 0 Blue 0
8 PM Fri 48 46 NW 2 2392 3400 0 Blue 0
9 PM Fri 48 46 NW 2 2392 3400 0 Blue 0
10 PM Fri 49 47 NW 3 2392 3400 0 Blue 0
11 PM Fri 49 47 NW 3 2392 3400 0 Blue 0
12 Midnight Sat 49 47 NW 3 2392 3400 0 Blue 0
1 AM Sat 49 47 NW 3 2392 3400 0 Blue 0
2 AM Sat 49 47 NW 3 2392 3400 0 Blue 0
3 AM Sat 48 46 NW 3 2392 3400 0 Blue 0
4 AM Sat 48 46 N 6 2392 3400 0 Blue 0
5 AM Sat 47 45 N 6 2392 3400 0 Blue 0
6 AM Sat 46 44 N 6 2392 3400 0 Blue 0
7 AM Sat 47 45 N 6 2392 3400 0 Blue 0
8 AM Sat 49 47 N 6 2392 3400 0 Blue 0
9 AM Sat 53 51 N 6 3196 3400 0 Blue 1
10 AM Sat 56 55 N 3 4919 3400 0 Blue 5
11 AM Sat 60 60 N 3 8284 5887 2487 White 10
12 Noon Sat 62 62 N 3 8708 6841 3441 White 12
1 PM Sat 63 63 N 3 8919 7536 4136 White 13
2 PM Sat 62 61 N 3 8497 6370 2970 White 11
3 PM Sat 60 58 N 3 6428 4882 1482 Blue 8
4 PM Sat 57 55 N 3 4919 3400 0 Blue 5
5 PM Sat 55 53 N 3 3560 3400 0 Blue 3
6 PM Sat 52 50 N 3 3013 3400 0 Blue 0
7 PM Sat 51 49 N 3 2535 3400 0 Blue 0
8 PM Sat 50 48 N 3 2392 3400 0 Blue 0
9 PM Sat 50 48 N 3 2392 3400 0 Blue 0
10 PM Sat 51 49 N 5 2535 3400 0 Blue 0
11 PM Sat 51 49 N 5 2535 3400 0 Blue 0
12 Midnight Sun 52 50 N 5 3013 3400 0 Blue 0
1 AM Sun 52 50 N 5 3013 3400 0 Blue 0
2 AM Sun 52 50 N 5 3013 3400 0 Blue 0
3 AM Sun 51 49 N 5 2535 3400 0 Blue 0
4 AM Sun 51 49 NW 3 2535 3400 0 Blue 0
5 AM Sun 50 48 NW 3 2392 3400 0 Blue 0
6 AM Sun 49 47 NW 3 2392 3400 0 Blue 0
7 AM Sun 50 48 NW 3 2392 3400 0 Blue 0
8 AM Sun 52 50 NW 3 3013 3400 0 Blue 0
9 AM Sun 55 53 NW 3 3560 3400 0 Blue 3
10 AM Sun 59 58 W 3 6428 4882 1482 Blue 8
11 AM Sun 62 61 W 3 8497 6370 2970 White 11
12 Noon Sun 64 63 W 3 8919 7536 4136 White 13
1 PM Sun 65 64 W 3 9098 8840 5440 Blue 14
2 PM Sun 64 63 W 3 8919 7536 4136 White 13
3 PM Sun 61 59 W 3 6905 5391 1991 Blue 9
4 PM Sun 58 56 W 5 5436 3555 155 Blue 6
5 PM Sun 55 53 W 5 3560 3400 0 Blue 3
6 PM Sun 52 50 W 5 3013 3400 0 Blue 0
7 PM Sun 50 48 W 5 2392 3400 0 Blue 0
8 PM Sun 50 48 W 5 2392 3400 0 Blue 0
9 PM Sun 50 48 W 5 2392 3400 0 Blue 0
10 PM Sun 50 48 NW 7 2392 3400 0 Blue 0
11 PM Sun 51 49 NW 7 2535 3400 0 Blue 0
12 Midnight Mon 51 49 NW 7 2535 3400 0 Blue 0
1 AM Mon 50 48 NW 7 2392 3400 0 Blue 0
2 AM Mon 50 48 NW 7 2392 3400 0 Blue 0
3 AM Mon 49 47 NW 7 2392 3400 0 Blue 0
4 AM Mon 48 46 NW 8 2392 3400 0 Blue 0
5 AM Mon 47 45 NW 8 2392 3400 0 Blue 0
6 AM Mon 46 44 NW 8 2392 3400 0 Blue 0
7 AM Mon 47 45 NW 8 2392 3400 0 Blue 0
8 AM Mon 49 47 NW 8 2392 3400 0 Blue 0
9 AM Mon 54 52 NW 8 3378 3400 0 Blue 2
10 AM Mon 58 56 N 13 5436 3555 155 Blue 6
11 AM Mon 61 60 N 13 8284 5887 2487 White 10
12 Noon Mon 63 62 N 13 8708 6841 3441 White 12
1 PM Mon 63 62 N 13 8708 6841 3441 White 12
2 PM Mon 61 59 N 13 6905 5391 1991 Blue 9
3 PM Mon 59 57 N 13 5938 4190 790 Blue 7
4 PM Mon 56 54 NW 12 4232 3400 0 Blue 4
5 PM Mon 53 51 NW 12 3196 3400 0 Blue 1
6 PM Mon 51 49 NW 12 2535 3400 0 Blue 0
7 PM Mon 50 48 NW 12 2392 3400 0 Blue 0
8 PM Mon 49 47 NW 12 2392 3400 0 Blue 0
9 PM Mon 49 47 NW 12 2392 3400 0 Blue 0
10 PM Mon 49 47 N 10 2392 3400 0 Blue 0
11 PM Mon 48 46 N 10 2392 3400 0 Blue 0
12 Midnight Tue 48 46 N 10 2392 3400 0 Blue 0
1 AM Tue 47 45 N 10 2392 3400 0 Blue 0
2 AM Tue 47 45 N 10 2392 3400 0 Blue 0
3 AM Tue 46 44 N 10 2392 3400 0 Blue 0
4 AM Tue 45 43 N 9 2392 3400 0 Blue 0
5 AM Tue 44 42 N 9 2392 3400 0 Blue 0
6 AM Tue 43 41 N 9 2392 3400 0 Blue 0
7 AM Tue 43 41 N 9 2392 3400 0 Blue 0
8 AM Tue 45 43 N 9 2392 3400 0 Blue 0
9 AM Tue 48 46 N 9 2392 3400 0 Blue 0
10 AM Tue 51 49 W 6 2535 3400 0 Blue 0
11 AM Tue 55 53 W 6 3560 3400 0 Blue 3
12 Noon Tue 57 55 W 6 4919 3400 0 Blue 5
1 PM Tue 57 55 W 6 4919 3400 0 Blue 5
2 PM Tue 54 52 W 6 3378 3400 0 Blue 2
3 PM Tue 50 48 W 6 2392 3400 0 Blue 0
4 PM Tue 46 44 S 9 2392 3400 0 Blue 0
5 PM Tue 43 41 S 9 2392 3400 0 Blue 0
6 PM Tue 42 40 S 9 2392 3400 0 Blue 0
7 PM Tue 42 40 S 9 2392 3400 0 Blue 0
8 PM Tue 42 40 S 9 2392 3400 0 Blue 0
9 PM Tue 42 40 S 9 2392 3400 0 Blue 0
10 PM Tue 42 40 NW 20 2392 3400 0 Blue 0
11 PM Tue 43 41 NW 20 2392 3400 0 Blue 0
12 Midnight Wed 45 43 NW 20 2392 3400 0 Blue 0
1 AM Wed 46 44 NW 20 2392 3400 0 Blue 0
2 AM Wed 46 44 NW 20 2392 3400 0 Blue 0
3 AM Wed 45 43 NW 20 2392 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]