Detailed Predictions for: Dunlap
Launch Altitude (f): 4460
LZ Altitude (f): 1950
Sounding

Station:

KOAK

Date/Time:

17 JAN 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)
4 AM Wed 42 37 NE 6 2224 4460 0 Blue 0
5 AM Wed 41 36 NE 6 2224 4460 0 Blue 0
6 AM Wed 41 36 NE 6 2224 4460 0 Blue 0
7 AM Wed 42 37 E 6 2224 4460 0 Blue 0
8 AM Wed 45 40 E 6 2224 4460 0 Blue 0
9 AM Wed 50 45 E 6 2224 4460 0 Blue 0
10 AM Wed 55 50 W 1 2224 4460 0 Blue 0
11 AM Wed 59 55 W 1 3019 4460 0 Blue 1
12 Noon Wed 63 59 W 1 3595 4460 0 Blue 5
1 PM Wed 65 61 W 2 3792 4460 0 Blue 7
2 PM Wed 67 62 W 2 3921 4460 0 Blue 8
3 PM Wed 67 62 W 2 3921 4460 0 Blue 8
4 PM Wed 65 60 W 2 3679 4460 0 Blue 6
5 PM Wed 62 57 W 2 3439 4460 0 Blue 3
6 PM Wed 57 52 W 2 2224 4460 0 Blue 0
7 PM Wed 54 49 E 1 2224 4460 0 Blue 0
8 PM Wed 51 46 E 1 2224 4460 0 Blue 0
9 PM Wed 50 45 E 1 2224 4460 0 Blue 0
10 PM Wed 49 44 NE 5 2224 4460 0 Blue 0
11 PM Wed 48 43 NE 5 2224 4460 0 Blue 0
12 Midnight Thu 47 42 NE 5 2224 4460 0 Blue 0
1 AM Thu 47 42 NE 6 2224 4460 0 Blue 0
2 AM Thu 46 41 NE 6 2224 4460 0 Blue 0
3 AM Thu 45 40 NE 6 2224 4460 0 Blue 0
4 AM Thu 44 39 NE 5 2224 4460 0 Blue 0
5 AM Thu 43 38 NE 5 2224 4460 0 Blue 0
6 AM Thu 43 38 NE 5 2224 4460 0 Blue 0
7 AM Thu 44 39 NE 7 2224 4460 0 Blue 0
8 AM Thu 47 42 NE 7 2224 4460 0 Blue 0
9 AM Thu 52 47 NE 7 2224 4460 0 Blue 0
10 AM Thu 57 52 S 3 2224 4460 0 Blue 0
11 AM Thu 62 57 S 3 3439 4460 0 Blue 3
12 Noon Thu 65 61 S 3 3792 4460 0 Blue 7
1 PM Thu 68 64 S 5 4189 4460 0 Blue 10
2 PM Thu 68 63 S 5 4051 4460 0 Blue 9
3 PM Thu 67 62 S 5 3921 4460 0 Blue 8
4 PM Thu 65 60 SE 3 3679 4460 0 Blue 6
5 PM Thu 62 57 SE 3 3439 4460 0 Blue 3
6 PM Thu 59 54 SE 3 2378 4460 0 Blue 0
7 PM Thu 56 51 SE 3 2224 4460 0 Blue 0
8 PM Thu 54 49 SE 3 2224 4460 0 Blue 0
9 PM Thu 52 47 SE 3 2224 4460 0 Blue 0
10 PM Thu 51 46 SE 5 2224 4460 0 Blue 0
11 PM Thu 50 45 SE 5 2224 4460 0 Blue 0
12 Midnight Fri 48 43 SE 5 2224 4460 0 Blue 0
1 AM Fri 47 42 SE 5 2224 4460 0 Blue 0
2 AM Fri 46 41 SE 5 2224 4460 0 Blue 0
3 AM Fri 45 40 SE 5 2224 4460 0 Blue 0
4 AM Fri 44 39 S 5 2224 4460 0 Blue 0
5 AM Fri 43 38 S 5 2224 4460 0 Blue 0
6 AM Fri 42 37 S 5 2224 4460 0 Blue 0
7 AM Fri 53 48 S 5 2224 4460 0 Blue 0
8 AM Fri 40 35 S 5 2224 4460 0 Blue 0
9 AM Fri 51 46 S 5 2224 4460 0 Blue 0
10 AM Fri 51 46 SW 6 2224 4460 0 Blue 0
11 AM Fri 51 46 SW 6 2224 4460 0 Blue 0
12 Noon Fri 51 46 SW 6 2224 4460 0 Blue 0
1 PM Fri 51 46 SW 6 2224 4460 0 Blue 0
2 PM Fri 51 46 SW 6 2224 4460 0 Blue 0
3 PM Fri 50 45 SW 6 2224 4460 0 Blue 0
4 PM Fri 49 44 NW 6 2224 4460 0 Blue 0
5 PM Fri 47 42 NW 6 2224 4460 0 Blue 0
6 PM Fri 45 40 NW 6 2224 4460 0 Blue 0
7 PM Fri 43 38 NW 6 2224 4460 0 Blue 0
8 PM Fri 42 37 NW 6 2224 4460 0 Blue 0
9 PM Fri 42 37 NW 6 2224 4460 0 Blue 0
10 PM Fri 41 36 W 5 2224 4460 0 Blue 0
11 PM Fri 40 35 W 5 2224 4460 0 Blue 0
12 Midnight Sat 39 34 W 5 2224 4460 0 Blue 0
1 AM Sat 37 32 W 5 2224 4460 0 Blue 0
2 AM Sat 36 31 W 5 2224 4460 0 Blue 0
3 AM Sat 35 30 W 5 2224 4460 0 Blue 0
4 AM Sat 33 28 NW 7 2224 4460 0 Blue 0
5 AM Sat 32 27 NW 7 2224 4460 0 Blue 0
6 AM Sat 31 26 NW 7 2224 4460 0 Blue 0
7 AM Sat 32 27 NW 7 2224 4460 0 Blue 0
8 AM Sat 34 29 NW 7 2224 4460 0 Blue 0
9 AM Sat 39 34 NW 7 2224 4460 0 Blue 0
10 AM Sat 43 39 W 3 2224 4460 0 Blue 0
11 AM Sat 46 42 W 3 2224 4460 0 Blue 0
12 Noon Sat 48 44 W 3 2224 4460 0 Blue 0
1 PM Sat 50 46 W 3 2224 4460 0 Blue 0
2 PM Sat 51 47 W 3 2224 4460 0 Blue 0
3 PM Sat 51 46 W 3 2224 4460 0 Blue 0
4 PM Sat 50 45 NW 7 2224 4460 0 Blue 0
5 PM Sat 47 42 NW 7 2224 4460 0 Blue 0
6 PM Sat 43 38 NW 7 2224 4460 0 Blue 0
7 PM Sat 41 36 NW 7 2224 4460 0 Blue 0
8 PM Sat 40 35 NW 7 2224 4460 0 Blue 0
9 PM Sat 41 36 NW 7 2224 4460 0 Blue 0
10 PM Sat 41 36 NE 5 2224 4460 0 Blue 0
11 PM Sat 39 34 NE 5 2224 4460 0 Blue 0
12 Midnight Sun 36 31 NE 5 2224 4460 0 Blue 0
1 AM Sun 34 29 NE 5 2224 4460 0 Blue 0
2 AM Sun 34 29 NE 5 2224 4460 0 Blue 0
3 AM Sun 35 30 NE 5 2224 4460 0 Blue 0
4 AM Sun 34 29 NE 7 2224 4460 0 Blue 0
5 AM Sun 33 28 NE 7 2224 4460 0 Blue 0
6 AM Sun 31 26 NE 7 2224 4460 0 Blue 0
7 AM Sun 31 26 NE 7 2224 4460 0 Blue 0
8 AM Sun 34 29 NE 7 2224 4460 0 Blue 0
9 AM Sun 39 34 NE 7 2224 4460 0 Blue 0
10 AM Sun 44 39 S 3 2224 4460 0 Blue 0
11 AM Sun 49 45 S 3 2224 4460 0 Blue 0
12 Noon Sun 52 48 S 3 2224 4460 0 Blue 0
1 PM Sun 55 51 S 3 2224 4460 0 Blue 0
2 PM Sun 56 51 S 3 2224 4460 0 Blue 0
3 PM Sun 56 51 S 3 2224 4460 0 Blue 0
4 PM Sun 54 49 SW 2 2224 4460 0 Blue 0
5 PM Sun 51 46 SW 2 2224 4460 0 Blue 0
6 PM Sun 47 42 SW 2 2224 4460 0 Blue 0
7 PM Sun 44 39 SW 2 2224 4460 0 Blue 0
8 PM Sun 42 37 SW 2 2224 4460 0 Blue 0
9 PM Sun 42 37 SW 2 2224 4460 0 Blue 0
10 PM Sun 42 37 E 6 2224 4460 0 Blue 0
11 PM Sun 42 37 E 6 2224 4460 0 Blue 0
12 Midnight Mon 42 37 E 6 2224 4460 0 Blue 0
1 AM Mon 42 37 E 6 2224 4460 0 Blue 0
2 AM Mon 40 35 E 6 2224 4460 0 Blue 0
3 AM Mon 38 33 E 6 2224 4460 0 Blue 0
4 AM Mon 37 32 E 5 2224 4460 0 Blue 0
5 AM Mon 36 31 E 5 2224 4460 0 Blue 0
6 AM Mon 37 32 E 5 2224 4460 0 Blue 0
7 AM Mon 39 34 E 5 2224 4460 0 Blue 0
8 AM Mon 43 38 E 5 2224 4460 0 Blue 0
9 AM Mon 48 43 E 5 2224 4460 0 Blue 0
10 AM Mon 53 48 E 6 2224 4460 0 Blue 0
11 AM Mon 55 50 E 6 2224 4460 0 Blue 0
12 Noon Mon 57 52 E 6 2224 4460 0 Blue 0
1 PM Mon 58 53 E 6 2224 4460 0 Blue 0
2 PM Mon 59 54 E 6 2378 4460 0 Blue 0
3 PM Mon 59 54 E 6 2378 4460 0 Blue 0
4 PM Mon 58 53 SW 5 2224 4460 0 Blue 0
5 PM Mon 55 50 SW 5 2224 4460 0 Blue 0
6 PM Mon 51 46 SW 5 2224 4460 0 Blue 0
7 PM Mon 48 43 SW 5 2224 4460 0 Blue 0
8 PM Mon 48 43 SW 5 2224 4460 0 Blue 0
9 PM Mon 48 43 SW 5 2224 4460 0 Blue 0
10 PM Mon 48 43 E 3 2224 4460 0 Blue 0
11 PM Mon 48 43 E 3 2224 4460 0 Blue 0
12 Midnight Tue 47 42 E 3 2224 4460 0 Blue 0
1 AM Tue 45 40 E 3 2224 4460 0 Blue 0
2 AM Tue 43 38 E 3 2224 4460 0 Blue 0
3 AM Tue 41 36 E 3 2224 4460 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