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

Station:

 KOAK

Date/Time:

 18 MAR 2010

Temp/Wind data from:

NOAA Digital Forecast

Time
(Local)		 High
Temp
Puddle
Temp
Wind
 (mph)		 Thermal
Ceiling
(ft)		 Soaring
Ceiling
(ft)		 Above
Launch
(ft)		 Thermal
Type		 Thermal
Index
(F)
5 AM Thu 46 46 E 9 1850 4460 0 Blue 0
6 AM Thu 44 44 E 9 1850 4460 0 Blue 0
7 AM Thu 44 44 E 9 1850 4460 0 Blue 0
8 AM Thu 45 45 E 6 1850 4460 0 Blue 0
9 AM Thu 51 52 E 6 1850 4460 0 Blue 0
10 AM Thu 57 59 E 6 1858 4460 0 Blue 0
11 AM Thu 61 64 SW 6 2867 4460 0 Blue 2
12 Noon Thu 64 68 SW 6 4692 4460 0 Blue 6
1 PM Thu 65 69 SW 6 6926 4460 0 Blue 7
2 PM Thu 67 71 W 6 7195 4679 219 Blue 9
3 PM Thu 67 70 W 6 7052 4501 41 Blue 8
4 PM Thu 68 70 W 6 7052 4501 41 Blue 8
5 PM Thu 68 68 W 3 4692 4460 0 Blue 6
6 PM Thu 65 65 W 3 3241 4460 0 Blue 3
7 PM Thu 60 60 W 3 2086 4460 0 Blue 0
8 PM Thu 57 57 E 3 1850 4460 0 Blue 0
9 PM Thu 54 54 E 3 1850 4460 0 Blue 0
10 PM Thu 53 53 E 3 1850 4460 0 Blue 0
11 PM Thu 51 51 E 9 1850 4460 0 Blue 0
12 Midnight Fri 50 50 E 9 1850 4460 0 Blue 0
1 AM Fri 49 49 E 9 1850 4460 0 Blue 0
2 AM Fri 47 47 E 6 1850 4460 0 Blue 0
3 AM Fri 47 47 E 6 1850 4460 0 Blue 0
4 AM Fri 46 46 E 6 1850 4460 0 Blue 0
5 AM Fri 43 43 NE 9 1850 4460 0 Blue 0
6 AM Fri 42 42 NE 9 1850 4460 0 Blue 0
7 AM Fri 42 42 NE 9 1850 4460 0 Blue 0
8 AM Fri 43 43 E 9 1850 4460 0 Blue 0
9 AM Fri 49 50 E 9 1850 4460 0 Blue 0
10 AM Fri 55 58 E 9 1850 4460 0 Blue 0
11 AM Fri 59 63 E 2 2714 4460 0 Blue 1
12 Noon Fri 62 67 E 2 4513 4460 0 Blue 5
1 PM Fri 63 69 E 2 6926 4460 0 Blue 7
2 PM Fri 65 70 SW 5 7052 4501 41 Blue 8
3 PM Fri 65 69 SW 5 6926 4460 0 Blue 7
4 PM Fri 66 68 SW 5 4692 4460 0 Blue 6
5 PM Fri 66 67 W 4 4513 4460 0 Blue 5
6 PM Fri 63 63 W 4 2714 4460 0 Blue 1
7 PM Fri 59 59 W 4 1858 4460 0 Blue 0
8 PM Fri 56 56 W 4 1850 4460 0 Blue 0
9 PM Fri 54 54 W 4 1850 4460 0 Blue 0
10 PM Fri 52 52 W 4 1850 4460 0 Blue 0
11 PM Fri 51 51 E 3 1850 4460 0 Blue 0
12 Midnight Sat 50 50 E 3 1850 4460 0 Blue 0
1 AM Sat 49 49 E 3 1850 4460 0 Blue 0
2 AM Sat 48 48 E 3 1850 4460 0 Blue 0
3 AM Sat 47 47 E 3 1850 4460 0 Blue 0
4 AM Sat 46 46 E 3 1850 4460 0 Blue 0
5 AM Sat 44 44 E 4 1850 4460 0 Blue 0
6 AM Sat 43 43 E 4 1850 4460 0 Blue 0
7 AM Sat 43 43 E 4 1850 4460 0 Blue 0
8 AM Sat 44 44 E 4 1850 4460 0 Blue 0
9 AM Sat 51 52 E 4 1850 4460 0 Blue 0
10 AM Sat 58 60 E 4 2086 4460 0 Blue 0
11 AM Sat 63 67 SW 4 4513 4460 0 Blue 5
12 Noon Sat 67 72 SW 4 7339 6907 2447 Blue 10
1 PM Sat 67 72 SW 4 7339 6907 2447 Blue 10
2 PM Sat 70 75 SW 4 7772 7316 2856 Blue 13
3 PM Sat 70 74 SW 4 7628 7172 2712 Blue 12
4 PM Sat 71 73 SW 4 7484 7033 2573 Blue 11
5 PM Sat 71 72 SW 2 7339 6907 2447 Blue 10
6 PM Sat 67 67 SW 2 4513 4460 0 Blue 5
7 PM Sat 62 62 SW 2 2539 4460 0 Blue 0
8 PM Sat 59 59 SW 2 1858 4460 0 Blue 0
9 PM Sat 56 56 SW 2 1850 4460 0 Blue 0
10 PM Sat 54 54 SW 2 1850 4460 0 Blue 0
11 PM Sat 53 53 E 6 1850 4460 0 Blue 0
12 Midnight Sun 52 52 E 6 1850 4460 0 Blue 0
1 AM Sun 50 50 E 6 1850 4460 0 Blue 0
2 AM Sun 49 49 E 6 1850 4460 0 Blue 0
3 AM Sun 48 48 E 6 1850 4460 0 Blue 0
4 AM Sun 47 47 E 6 1850 4460 0 Blue 0
5 AM Sun 45 45 E 8 1850 4460 0 Blue 0
6 AM Sun 43 43 E 8 1850 4460 0 Blue 0
7 AM Sun 43 43 E 8 1850 4460 0 Blue 0
8 AM Sun 44 44 E 8 1850 4460 0 Blue 0
9 AM Sun 51 52 E 8 1850 4460 0 Blue 0
10 AM Sun 59 61 E 8 2313 4460 0 Blue 0
11 AM Sun 63 66 SW 5 3978 4460 0 Blue 4
12 Noon Sun 67 71 SW 5 7195 4679 219 Blue 9
1 PM Sun 68 73 SW 5 7484 7033 2573 Blue 11
2 PM Sun 71 75 SW 5 7772 7316 2856 Blue 13
3 PM Sun 71 74 SW 5 7628 7172 2712 Blue 12
4 PM Sun 72 74 SW 5 7628 7172 2712 Blue 12
5 PM Sun 72 73 SW 4 7484 7033 2573 Blue 11
6 PM Sun 68 68 SW 4 4692 4460 0 Blue 6
7 PM Sun 62 62 SW 4 2539 4460 0 Blue 0
8 PM Sun 59 59 SW 4 1858 4460 0 Blue 0
9 PM Sun 56 56 SW 4 1850 4460 0 Blue 0
10 PM Sun 54 54 SW 4 1850 4460 0 Blue 0
11 PM Sun 52 52 E 4 1850 4460 0 Blue 0
12 Midnight Mon 51 51 E 4 1850 4460 0 Blue 0
1 AM Mon 49 49 E 4 1850 4460 0 Blue 0
2 AM Mon 47 47 E 4 1850 4460 0 Blue 0
3 AM Mon 47 47 E 4 1850 4460 0 Blue 0
4 AM Mon 45 45 E 4 1850 4460 0 Blue 0
5 AM Mon 43 43 E 5 1850 4460 0 Blue 0
6 AM Mon 41 41 E 5 1850 4460 0 Blue 0
7 AM Mon 41 41 E 5 1850 4460 0 Blue 0
8 AM Mon 42 42 E 5 1850 4460 0 Blue 0
9 AM Mon 48 49 E 5 1850 4460 0 Blue 0
10 AM Mon 54 56 E 5 1850 4460 0 Blue 0
11 AM Mon 59 62 W 6 2539 4460 0 Blue 0
12 Noon Mon 62 66 W 6 3978 4460 0 Blue 4
1 PM Mon 63 67 W 6 4513 4460 0 Blue 5
2 PM Mon 65 69 W 6 6926 4460 0 Blue 7
3 PM Mon 65 68 W 6 4692 4460 0 Blue 6
4 PM Mon 66 68 W 6 4692 4460 0 Blue 6
5 PM Mon 66 67 W 7 4513 4460 0 Blue 5
6 PM Mon 63 63 W 7 2714 4460 0 Blue 1
7 PM Mon 58 58 W 7 1850 4460 0 Blue 0
8 PM Mon 55 55 W 7 1850 4460 0 Blue 0
9 PM Mon 52 52 W 7 1850 4460 0 Blue 0
10 PM Mon 51 51 W 7 1850 4460 0 Blue 0
11 PM Mon 49 49 NE 2 1850 4460 0 Blue 0
12 Midnight Tue 48 48 NE 2 1850 4460 0 Blue 0
1 AM Tue 47 47 NE 2 1850 4460 0 Blue 0
2 AM Tue 45 45 NE 2 1850 4460 0 Blue 0
3 AM Tue 45 45 NE 2 1850 4460 0 Blue 0
4 AM Tue 44 44 NE 2 1850 4460 0 Blue 0
5 AM Tue 41 41 S 1 1850 4460 0 Blue 0
6 AM Tue 40 40 S 1 1850 4460 0 Blue 0
7 AM Tue 40 40 S 1 1850 4460 0 Blue 0
8 AM Tue 41 41 S 1 1850 4460 0 Blue 0
9 AM Tue 46 47 S 1 1850 4460 0 Blue 0
10 AM Tue 51 53 S 1 1850 4460 0 Blue 0
11 AM Tue 54 57 SW 6 1850 4460 0 Blue 0
12 Noon Tue 57 61 SW 6 2313 4460 0 Blue 0
1 PM Tue 57 61 SW 6 2313 4460 0 Blue 0
2 PM Tue 59 63 SW 6 2714 4460 0 Blue 1
3 PM Tue 59 62 SW 6 2539 4460 0 Blue 0
4 PM Tue 60 62 SW 6 2539 4460 0 Blue 0
5 PM Tue 60 61 NW 5 2313 4460 0 Blue 0
6 PM Tue 57 57 NW 5 1850 4460 0 Blue 0
7 PM Tue 53 53 NW 5 1850 4460 0 Blue 0
8 PM Tue 51 51 NW 5 1850 4460 0 Blue 0
9 PM Tue 49 49 NW 5 1850 4460 0 Blue 0
10 PM Tue 48 48 NW 5 1850 4460 0 Blue 0
11 PM Tue 46 46 E 6 1850 4460 0 Blue 0
12 Midnight Wed 45 45 E 6 1850 4460 0 Blue 0
1 AM Wed 44 44 E 6 1850 4460 0 Blue 0
2 AM Wed 43 43 E 6 1850 4460 0 Blue 0
3 AM Wed 43 43 E 6 1850 4460 0 Blue 0
4 AM Wed 42 42 E 6 1850 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