Detailed Predictions for: Dumps
Launch Altitude (f): 200
LZ Altitude (f): 0
Sounding

Station:

KOAK

Date/Time:

27 MAY 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 Sun 51 31 SW 7 0 200 0 Blue 0
6 AM Sun 51 31 SW 7 0 200 0 Blue 0
7 AM Sun 51 31 SW 7 0 200 0 Blue 0
8 AM Sun 53 33 SW 9 0 200 0 Blue 0
9 AM Sun 54 35 SW 9 0 200 0 Blue 0
10 AM Sun 56 39 SW 9 0 200 0 Blue 0
11 AM Sun 58 44 SW 9 0 200 0 Blue 0
12 Noon Sun 59 46 SW 9 0 200 0 Blue 0
1 PM Sun 60 47 SW 9 0 200 0 Blue 0
2 PM Sun 60 47 SW 12 0 200 0 Blue 0
3 PM Sun 60 46 SW 12 0 200 0 Blue 0
4 PM Sun 60 44 SW 12 0 200 0 Blue 0
5 PM Sun 59 42 SW 13 0 200 0 Blue 0
6 PM Sun 58 39 SW 13 0 200 0 Blue 0
7 PM Sun 57 37 SW 13 0 200 0 Blue 0
8 PM Sun 55 35 SW 14 0 200 0 Blue 0
9 PM Sun 54 34 SW 14 0 200 0 Blue 0
10 PM Sun 54 34 SW 14 0 200 0 Blue 0
11 PM Sun 54 34 SW 13 0 200 0 Blue 0
12 Midnight Mon 54 34 SW 13 0 200 0 Blue 0
1 AM Mon 54 34 SW 13 0 200 0 Blue 0
2 AM Mon 54 34 SW 7 0 200 0 Blue 0
3 AM Mon 54 34 SW 7 0 200 0 Blue 0
4 AM Mon 54 34 SW 7 0 200 0 Blue 0
5 AM Mon 53 33 NW 2 0 200 0 Blue 0
6 AM Mon 53 33 NW 2 0 200 0 Blue 0
7 AM Mon 54 34 NW 2 0 200 0 Blue 0
8 AM Mon 55 36 W 5 0 200 0 Blue 0
9 AM Mon 57 39 W 5 0 200 0 Blue 0
10 AM Mon 60 43 W 5 0 200 0 Blue 0
11 AM Mon 62 48 SW 6 0 200 0 Blue 0
12 Noon Mon 63 50 SW 6 0 200 0 Blue 0
1 PM Mon 64 52 SW 6 0 200 0 Blue 0
2 PM Mon 65 52 W 8 0 200 0 Blue 0
3 PM Mon 65 51 W 8 0 200 0 Blue 0
4 PM Mon 64 48 W 8 0 200 0 Blue 0
5 PM Mon 62 45 W 16 0 200 0 Blue 0
6 PM Mon 61 42 W 16 0 200 0 Blue 0
7 PM Mon 59 39 W 16 0 200 0 Blue 0
8 PM Mon 57 37 W 16 0 200 0 Blue 0
9 PM Mon 56 36 W 16 0 200 0 Blue 0
10 PM Mon 55 35 W 16 0 200 0 Blue 0
11 PM Mon 55 35 W 12 0 200 0 Blue 0
12 Midnight Tue 54 34 W 12 0 200 0 Blue 0
1 AM Tue 55 35 W 12 0 200 0 Blue 0
2 AM Tue 55 35 W 12 0 200 0 Blue 0
3 AM Tue 55 35 W 12 0 200 0 Blue 0
4 AM Tue 54 34 W 12 0 200 0 Blue 0
5 AM Tue 54 34 W 9 0 200 0 Blue 0
6 AM Tue 54 34 W 9 0 200 0 Blue 0
7 AM Tue 54 34 W 9 0 200 0 Blue 0
8 AM Tue 55 35 W 9 0 200 0 Blue 0
9 AM Tue 56 36 W 9 0 200 0 Blue 0
10 AM Tue 57 38 W 9 0 200 0 Blue 0
11 AM Tue 58 44 W 13 0 200 0 Blue 0
12 Noon Tue 59 46 W 13 0 200 0 Blue 0
1 PM Tue 60 48 W 13 0 200 0 Blue 0
2 PM Tue 60 47 W 13 0 200 0 Blue 0
3 PM Tue 60 46 W 13 0 200 0 Blue 0
4 PM Tue 60 45 W 13 0 200 0 Blue 0
5 PM Tue 58 41 W 21 0 200 0 Blue 0
6 PM Tue 58 39 W 21 0 200 0 Blue 0
7 PM Tue 56 36 W 21 0 200 0 Blue 0
8 PM Tue 55 35 W 21 0 200 0 Blue 0
9 PM Tue 54 34 W 21 0 200 0 Blue 0
10 PM Tue 54 34 W 21 0 200 0 Blue 0
11 PM Tue 54 34 W 17 0 200 0 Blue 0
12 Midnight Wed 53 33 W 17 0 200 0 Blue 0
1 AM Wed 54 34 W 17 0 200 0 Blue 0
2 AM Wed 54 34 W 17 0 200 0 Blue 0
3 AM Wed 53 33 W 17 0 200 0 Blue 0
4 AM Wed 53 33 W 17 0 200 0 Blue 0
5 AM Wed 53 33 W 15 0 200 0 Blue 0
6 AM Wed 52 32 W 15 0 200 0 Blue 0
7 AM Wed 53 33 W 15 0 200 0 Blue 0
8 AM Wed 53 33 W 15 0 200 0 Blue 0
9 AM Wed 54 34 W 15 0 200 0 Blue 0
10 AM Wed 55 35 W 15 0 200 0 Blue 0
11 AM Wed 56 41 W 20 0 200 0 Blue 0
12 Noon Wed 56 42 W 20 0 200 0 Blue 0
1 PM Wed 56 43 W 20 0 200 0 Blue 0
2 PM Wed 57 43 W 20 0 200 0 Blue 0
3 PM Wed 57 42 W 20 0 200 0 Blue 0
4 PM Wed 56 40 W 20 0 200 0 Blue 0
5 PM Wed 56 38 W 21 0 200 0 Blue 0
6 PM Wed 55 36 W 21 0 200 0 Blue 0
7 PM Wed 54 34 W 21 0 200 0 Blue 0
8 PM Wed 53 33 W 21 0 200 0 Blue 0
9 PM Wed 53 33 W 21 0 200 0 Blue 0
10 PM Wed 53 33 W 21 0 200 0 Blue 0
11 PM Wed 53 33 W 15 0 200 0 Blue 0
12 Midnight Thu 52 32 W 15 0 200 0 Blue 0
1 AM Thu 53 33 W 15 0 200 0 Blue 0
2 AM Thu 52 32 W 15 0 200 0 Blue 0
3 AM Thu 52 32 W 15 0 200 0 Blue 0
4 AM Thu 52 32 W 15 0 200 0 Blue 0
5 AM Thu 52 32 W 18 0 200 0 Blue 0
6 AM Thu 52 32 W 18 0 200 0 Blue 0
7 AM Thu 52 32 W 18 0 200 0 Blue 0
8 AM Thu 53 33 W 18 0 200 0 Blue 0
9 AM Thu 54 35 W 18 0 200 0 Blue 0
10 AM Thu 54 36 W 18 0 200 0 Blue 0
11 AM Thu 55 41 W 17 0 200 0 Blue 0
12 Noon Thu 56 43 W 17 0 200 0 Blue 0
1 PM Thu 56 43 W 17 0 200 0 Blue 0
2 PM Thu 56 43 W 17 0 200 0 Blue 0
3 PM Thu 56 42 W 17 0 200 0 Blue 0
4 PM Thu 56 40 W 17 0 200 0 Blue 0
5 PM Thu 55 37 W 21 0 200 0 Blue 0
6 PM Thu 55 36 W 21 0 200 0 Blue 0
7 PM Thu 54 34 W 21 0 200 0 Blue 0
8 PM Thu 53 33 W 21 0 200 0 Blue 0
9 PM Thu 52 32 W 21 0 200 0 Blue 0
10 PM Thu 52 32 W 21 0 200 0 Blue 0
11 PM Thu 52 32 W 17 0 200 0 Blue 0
12 Midnight Fri 52 32 W 17 0 200 0 Blue 0
1 AM Fri 52 32 W 17 0 200 0 Blue 0
2 AM Fri 52 32 W 17 0 200 0 Blue 0
3 AM Fri 52 32 W 17 0 200 0 Blue 0
4 AM Fri 52 32 W 17 0 200 0 Blue 0
5 AM Fri 52 32 NW 14 0 200 0 Blue 0
6 AM Fri 52 32 NW 14 0 200 0 Blue 0
7 AM Fri 52 32 NW 14 0 200 0 Blue 0
8 AM Fri 53 33 NW 14 0 200 0 Blue 0
9 AM Fri 54 35 NW 14 0 200 0 Blue 0
10 AM Fri 55 37 NW 14 0 200 0 Blue 0
11 AM Fri 56 42 NW 9 0 200 0 Blue 0
12 Noon Fri 57 44 NW 9 0 200 0 Blue 0
1 PM Fri 58 45 NW 9 0 200 0 Blue 0
2 PM Fri 58 45 NW 9 0 200 0 Blue 0
3 PM Fri 58 44 NW 9 0 200 0 Blue 0
4 PM Fri 58 42 NW 9 0 200 0 Blue 0
5 PM Fri 57 39 W 16 0 200 0 Blue 0
6 PM Fri 56 37 W 16 0 200 0 Blue 0
7 PM Fri 55 35 W 16 0 200 0 Blue 0
8 PM Fri 54 34 W 16 0 200 0 Blue 0
9 PM Fri 53 33 W 16 0 200 0 Blue 0
10 PM Fri 53 33 W 16 0 200 0 Blue 0
11 PM Fri 53 33 NW 9 0 200 0 Blue 0
12 Midnight Sat 52 32 NW 9 0 200 0 Blue 0
1 AM Sat 53 33 NW 9 0 200 0 Blue 0
2 AM Sat 53 33 NW 9 0 200 0 Blue 0
3 AM Sat 53 33 NW 9 0 200 0 Blue 0
4 AM Sat 52 32 NW 9 0 200 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