Detailed Predictions for: Dunlap
Launch Altitude (f): 4600
LZ Altitude (f): 2200
Sounding

Station:

KVBG

Date/Time:

18 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 Thu 51 51 E 5 3973 4600 0 Blue 0
5 AM Thu 51 51 E 5 3973 4600 0 Blue 0
6 AM Thu 51 51 E 5 3973 4600 0 Blue 0
7 AM Thu 52 52 SE 6 3973 4600 0 Blue 0
8 AM Thu 54 54 SE 6 3973 4600 0 Blue 0
9 AM Thu 57 57 SE 6 3973 4600 0 Blue 0
10 AM Thu 59 59 S 5 3973 4600 0 Blue 0
11 AM Thu 60 61 S 5 4376 4600 0 Blue 0
12 Noon Thu 61 62 S 5 4758 4600 0 Blue 0
1 PM Thu 61 62 SW 8 4758 4600 0 Blue 0
2 PM Thu 61 61 SW 8 4376 4600 0 Blue 0
3 PM Thu 60 60 SW 8 3989 4600 0 Blue 0
4 PM Thu 59 59 S 7 3973 4600 0 Blue 0
5 PM Thu 56 56 S 7 3973 4600 0 Blue 0
6 PM Thu 53 53 S 7 3973 4600 0 Blue 0
7 PM Thu 50 50 S 9 3973 4600 0 Blue 0
8 PM Thu 49 49 S 9 3973 4600 0 Blue 0
9 PM Thu 49 49 S 9 3973 4600 0 Blue 0
10 PM Thu 48 48 S 12 3973 4600 0 Blue 0
11 PM Thu 47 47 S 12 3973 4600 0 Blue 0
12 Midnight Fri 46 46 S 12 3973 4600 0 Blue 0
1 AM Fri 45 45 S 10 3973 4600 0 Blue 0
2 AM Fri 44 44 S 10 3973 4600 0 Blue 0
3 AM Fri 43 43 S 10 3973 4600 0 Blue 0
4 AM Fri 42 42 S 6 3973 4600 0 Blue 0
5 AM Fri 41 41 S 6 3973 4600 0 Blue 0
6 AM Fri 41 41 S 6 3973 4600 0 Blue 0
7 AM Fri 43 43 S 6 3973 4600 0 Blue 0
8 AM Fri 40 40 S 6 3973 4600 0 Blue 0
9 AM Fri 41 41 S 6 3973 4600 0 Blue 0
10 AM Fri 41 41 W 6 3973 4600 0 Blue 0
11 AM Fri 41 41 W 6 3973 4600 0 Blue 0
12 Noon Fri 41 41 W 6 3973 4600 0 Blue 0
1 PM Fri 41 41 W 6 3973 4600 0 Blue 0
2 PM Fri 40 40 W 6 3973 4600 0 Blue 0
3 PM Fri 40 40 W 6 3973 4600 0 Blue 0
4 PM Fri 39 39 NW 10 3973 4600 0 Blue 0
5 PM Fri 38 38 NW 10 3973 4600 0 Blue 0
6 PM Fri 37 37 NW 10 3973 4600 0 Blue 0
7 PM Fri 37 37 NW 10 3973 4600 0 Blue 0
8 PM Fri 36 36 NW 10 3973 4600 0 Blue 0
9 PM Fri 35 35 NW 10 3973 4600 0 Blue 0
10 PM Fri 34 34 NW 12 3973 4600 0 Blue 0
11 PM Fri 33 33 NW 12 3973 4600 0 Blue 0
12 Midnight Sat 32 32 NW 12 3973 4600 0 Blue 0
1 AM Sat 31 31 NW 12 3973 4600 0 Blue 0
2 AM Sat 31 31 NW 12 3973 4600 0 Blue 0
3 AM Sat 30 30 NW 12 3973 4600 0 Blue 0
4 AM Sat 29 29 NW 6 3973 4600 0 Blue 0
5 AM Sat 29 29 NW 6 3973 4600 0 Blue 0
6 AM Sat 28 28 NW 6 3973 4600 0 Blue 0
7 AM Sat 28 28 NW 6 3973 4600 0 Blue 0
8 AM Sat 30 30 NW 6 3973 4600 0 Blue 0
9 AM Sat 33 33 NW 6 3973 4600 0 Blue 0
10 AM Sat 36 37 SW 8 3973 4600 0 Blue 0
11 AM Sat 37 38 SW 8 3973 4600 0 Blue 0
12 Noon Sat 38 39 SW 8 3973 4600 0 Blue 0
1 PM Sat 39 40 SW 8 3973 4600 0 Blue 0
2 PM Sat 39 40 SW 8 3973 4600 0 Blue 0
3 PM Sat 39 39 SW 8 3973 4600 0 Blue 0
4 PM Sat 38 38 NW 10 3973 4600 0 Blue 0
5 PM Sat 37 37 NW 10 3973 4600 0 Blue 0
6 PM Sat 36 36 NW 10 3973 4600 0 Blue 0
7 PM Sat 35 35 NW 10 3973 4600 0 Blue 0
8 PM Sat 35 35 NW 10 3973 4600 0 Blue 0
9 PM Sat 35 35 NW 10 3973 4600 0 Blue 0
10 PM Sat 35 35 NE 5 3973 4600 0 Blue 0
11 PM Sat 34 34 NE 5 3973 4600 0 Blue 0
12 Midnight Sun 32 32 NE 5 3973 4600 0 Blue 0
1 AM Sun 31 31 NE 5 3973 4600 0 Blue 0
2 AM Sun 31 31 NE 5 3973 4600 0 Blue 0
3 AM Sun 31 31 NE 5 3973 4600 0 Blue 0
4 AM Sun 31 31 E 5 3973 4600 0 Blue 0
5 AM Sun 30 30 E 5 3973 4600 0 Blue 0
6 AM Sun 30 30 E 5 3973 4600 0 Blue 0
7 AM Sun 31 31 E 5 3973 4600 0 Blue 0
8 AM Sun 33 33 E 5 3973 4600 0 Blue 0
9 AM Sun 37 37 E 5 3973 4600 0 Blue 0
10 AM Sun 40 40 SW 5 3973 4600 0 Blue 0
11 AM Sun 42 43 SW 5 3973 4600 0 Blue 0
12 Noon Sun 43 44 SW 5 3973 4600 0 Blue 0
1 PM Sun 44 45 SW 5 3973 4600 0 Blue 0
2 PM Sun 44 44 SW 5 3973 4600 0 Blue 0
3 PM Sun 44 44 SW 5 3973 4600 0 Blue 0
4 PM Sun 44 44 S 2 3973 4600 0 Blue 0
5 PM Sun 42 42 S 2 3973 4600 0 Blue 0
6 PM Sun 41 41 S 2 3973 4600 0 Blue 0
7 PM Sun 40 40 S 2 3973 4600 0 Blue 0
8 PM Sun 39 39 S 2 3973 4600 0 Blue 0
9 PM Sun 39 39 S 2 3973 4600 0 Blue 0
10 PM Sun 39 39 E 6 3973 4600 0 Blue 0
11 PM Sun 38 38 E 6 3973 4600 0 Blue 0
12 Midnight Mon 38 38 E 6 3973 4600 0 Blue 0
1 AM Mon 38 38 E 6 3973 4600 0 Blue 0
2 AM Mon 38 38 E 6 3973 4600 0 Blue 0
3 AM Mon 38 38 E 6 3973 4600 0 Blue 0
4 AM Mon 38 38 E 6 3973 4600 0 Blue 0
5 AM Mon 37 37 E 6 3973 4600 0 Blue 0
6 AM Mon 37 37 E 6 3973 4600 0 Blue 0
7 AM Mon 38 38 E 6 3973 4600 0 Blue 0
8 AM Mon 39 39 E 6 3973 4600 0 Blue 0
9 AM Mon 42 42 E 6 3973 4600 0 Blue 0
10 AM Mon 45 45 SW 3 3973 4600 0 Blue 0
11 AM Mon 46 46 SW 3 3973 4600 0 Blue 0
12 Noon Mon 47 47 SW 3 3973 4600 0 Blue 0
1 PM Mon 48 48 SW 3 3973 4600 0 Blue 0
2 PM Mon 48 48 SW 3 3973 4600 0 Blue 0
3 PM Mon 48 48 SW 3 3973 4600 0 Blue 0
4 PM Mon 47 47 N 2 3973 4600 0 Blue 0
5 PM Mon 46 46 N 2 3973 4600 0 Blue 0
6 PM Mon 45 45 N 2 3973 4600 0 Blue 0
7 PM Mon 45 45 N 2 3973 4600 0 Blue 0
8 PM Mon 44 44 N 2 3973 4600 0 Blue 0
9 PM Mon 43 43 N 2 3973 4600 0 Blue 0
10 PM Mon 43 43 E 5 3973 4600 0 Blue 0
11 PM Mon 43 43 E 5 3973 4600 0 Blue 0
12 Midnight Tue 42 42 E 5 3973 4600 0 Blue 0
1 AM Tue 42 42 E 5 3973 4600 0 Blue 0
2 AM Tue 42 42 E 5 3973 4600 0 Blue 0
3 AM Tue 42 42 E 5 3973 4600 0 Blue 0
4 AM Tue 41 41 E 7 3973 4600 0 Blue 0
5 AM Tue 40 40 E 7 3973 4600 0 Blue 0
6 AM Tue 40 40 E 7 3973 4600 0 Blue 0
7 AM Tue 41 41 E 7 3973 4600 0 Blue 0
8 AM Tue 43 43 E 7 3973 4600 0 Blue 0
9 AM Tue 46 46 E 7 3973 4600 0 Blue 0
10 AM Tue 50 51 SW 5 3973 4600 0 Blue 0
11 AM Tue 52 53 SW 5 3973 4600 0 Blue 0
12 Noon Tue 53 54 SW 5 3973 4600 0 Blue 0
1 PM Tue 53 54 SW 5 3973 4600 0 Blue 0
2 PM Tue 54 55 SW 5 3973 4600 0 Blue 0
3 PM Tue 54 54 SW 5 3973 4600 0 Blue 0
4 PM Tue 53 53 N 2 3973 4600 0 Blue 0
5 PM Tue 51 51 N 2 3973 4600 0 Blue 0
6 PM Tue 49 49 N 2 3973 4600 0 Blue 0
7 PM Tue 47 47 N 2 3973 4600 0 Blue 0
8 PM Tue 47 47 N 2 3973 4600 0 Blue 0
9 PM Tue 47 47 N 2 3973 4600 0 Blue 0
10 PM Tue 47 47 E 6 3973 4600 0 Blue 0
11 PM Tue 47 47 E 6 3973 4600 0 Blue 0
12 Midnight Wed 46 46 E 6 3973 4600 0 Blue 0
1 AM Wed 46 46 E 6 3973 4600 0 Blue 0
2 AM Wed 45 45 E 6 3973 4600 0 Blue 0
3 AM Wed 45 45 E 6 3973 4600 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