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

Station:

 KVBG

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 47 47 E 7 2546 4600 0 Blue 0
6 AM Thu 44 44 E 7 2546 4600 0 Blue 0
7 AM Thu 43 43 E 7 2546 4600 0 Blue 0
8 AM Thu 43 43 E 3 2546 4600 0 Blue 0
9 AM Thu 48 49 E 3 2546 4600 0 Blue 0
10 AM Thu 58 60 E 3 7786 4600 0 Blue 3
11 AM Thu 58 61 SW 5 7864 6425 1825 Blue 4
12 Noon Thu 62 66 SW 5 9404 8024 3424 Blue 9
1 PM Thu 63 67 SW 5 9799 8539 3939 Blue 10
2 PM Thu 61 64 W 5 8595 7855 3255 Blue 7
3 PM Thu 61 64 W 5 8595 7855 3255 Blue 7
4 PM Thu 63 65 W 5 9003 7934 3334 Blue 8
5 PM Thu 59 59 W 2 7586 4600 0 Blue 2
6 PM Thu 56 56 W 2 3718 4600 0 Blue 0
7 PM Thu 56 56 W 2 3718 4600 0 Blue 0
8 PM Thu 54 54 E 3 2546 4600 0 Blue 0
9 PM Thu 50 50 E 3 2546 4600 0 Blue 0
10 PM Thu 49 49 E 3 2546 4600 0 Blue 0
11 PM Thu 49 49 E 11 2546 4600 0 Blue 0
12 Midnight Fri 48 48 E 11 2546 4600 0 Blue 0
1 AM Fri 48 48 E 11 2546 4600 0 Blue 0
2 AM Fri 47 47 E 5 2546 4600 0 Blue 0
3 AM Fri 47 47 E 5 2546 4600 0 Blue 0
4 AM Fri 47 47 E 5 2546 4600 0 Blue 0
5 AM Fri 46 46 E 7 2546 4600 0 Blue 0
6 AM Fri 43 43 E 7 2546 4600 0 Blue 0
7 AM Fri 42 42 E 7 2546 4600 0 Blue 0
8 AM Fri 42 42 E 9 2546 4600 0 Blue 0
9 AM Fri 47 48 E 9 2546 4600 0 Blue 0
10 AM Fri 57 60 E 9 7786 4600 0 Blue 3
11 AM Fri 58 62 E 2 7943 7551 2951 Blue 5
12 Noon Fri 62 67 E 2 9799 8539 3939 Blue 10
1 PM Fri 63 69 E 2 10456 9339 4739 Blue 12
2 PM Fri 61 66 SW 4 9404 8024 3424 Blue 9
3 PM Fri 61 65 SW 4 9003 7934 3334 Blue 8
4 PM Fri 63 65 SW 4 9003 7934 3334 Blue 8
5 PM Fri 59 60 W 3 7786 4600 0 Blue 3
6 PM Fri 57 57 W 3 4588 4600 0 Blue 0
7 PM Fri 57 57 W 3 4588 4600 0 Blue 0
8 PM Fri 54 54 W 3 2546 4600 0 Blue 0
9 PM Fri 52 52 W 3 2546 4600 0 Blue 0
10 PM Fri 51 51 W 3 2546 4600 0 Blue 0
11 PM Fri 50 50 SE 2 2546 4600 0 Blue 0
12 Midnight Sat 49 49 SE 2 2546 4600 0 Blue 0
1 AM Sat 49 49 SE 2 2546 4600 0 Blue 0
2 AM Sat 49 49 SE 2 2546 4600 0 Blue 0
3 AM Sat 48 48 SE 2 2546 4600 0 Blue 0
4 AM Sat 49 49 SE 2 2546 4600 0 Blue 0
5 AM Sat 47 47 E 2 2546 4600 0 Blue 0
6 AM Sat 44 44 E 2 2546 4600 0 Blue 0
7 AM Sat 44 44 E 2 2546 4600 0 Blue 0
8 AM Sat 44 44 E 2 2546 4600 0 Blue 0
9 AM Sat 50 51 E 2 2546 4600 0 Blue 0
10 AM Sat 61 63 E 2 8181 7777 3177 Blue 6
11 AM Sat 63 67 SW 3 9799 8539 3939 Blue 10
12 Noon Sat 66 71 SW 3 11042 10115 5515 Blue 14
1 PM Sat 68 73 SW 3 12125 10680 6080 Blue 16
2 PM Sat 65 70 SW 3 10739 9730 5130 Blue 13
3 PM Sat 66 70 SW 3 10739 9730 5130 Blue 13
4 PM Sat 68 70 SW 3 10739 9730 5130 Blue 13
5 PM Sat 64 65 SW 2 9003 7934 3334 Blue 8
6 PM Sat 61 61 SW 2 7864 6425 1825 Blue 4
7 PM Sat 61 61 SW 2 7864 6425 1825 Blue 4
8 PM Sat 58 58 SW 2 6564 4600 0 Blue 1
9 PM Sat 55 55 SW 2 2765 4600 0 Blue 0
10 PM Sat 54 54 SW 2 2546 4600 0 Blue 0
11 PM Sat 54 54 E 3 2546 4600 0 Blue 0
12 Midnight Sun 52 52 E 3 2546 4600 0 Blue 0
1 AM Sun 52 52 E 3 2546 4600 0 Blue 0
2 AM Sun 51 51 E 3 2546 4600 0 Blue 0
3 AM Sun 51 51 E 3 2546 4600 0 Blue 0
4 AM Sun 51 51 E 3 2546 4600 0 Blue 0
5 AM Sun 50 50 E 5 2546 4600 0 Blue 0
6 AM Sun 47 47 E 5 2546 4600 0 Blue 0
7 AM Sun 46 46 E 5 2546 4600 0 Blue 0
8 AM Sun 46 46 E 5 2546 4600 0 Blue 0
9 AM Sun 50 51 E 5 2546 4600 0 Blue 0
10 AM Sun 58 60 E 5 7786 4600 0 Blue 3
11 AM Sun 59 62 SW 3 7943 7551 2951 Blue 5
12 Noon Sun 62 66 SW 3 9404 8024 3424 Blue 9
1 PM Sun 63 67 SW 3 9799 8539 3939 Blue 10
2 PM Sun 61 65 SW 3 9003 7934 3334 Blue 8
3 PM Sun 61 64 SW 3 8595 7855 3255 Blue 7
4 PM Sun 63 65 SW 3 9003 7934 3334 Blue 8
5 PM Sun 59 60 SW 4 7786 4600 0 Blue 3
6 PM Sun 57 57 SW 4 4588 4600 0 Blue 0
7 PM Sun 56 56 SW 4 3718 4600 0 Blue 0
8 PM Sun 54 54 SW 4 2546 4600 0 Blue 0
9 PM Sun 51 51 SW 4 2546 4600 0 Blue 0
10 PM Sun 50 50 SW 4 2546 4600 0 Blue 0
11 PM Sun 50 50 E 3 2546 4600 0 Blue 0
12 Midnight Mon 49 49 E 3 2546 4600 0 Blue 0
1 AM Mon 48 48 E 3 2546 4600 0 Blue 0
2 AM Mon 48 48 E 3 2546 4600 0 Blue 0
3 AM Mon 48 48 E 3 2546 4600 0 Blue 0
4 AM Mon 48 48 E 3 2546 4600 0 Blue 0
5 AM Mon 46 46 E 3 2546 4600 0 Blue 0
6 AM Mon 44 44 E 3 2546 4600 0 Blue 0
7 AM Mon 43 43 E 3 2546 4600 0 Blue 0
8 AM Mon 43 43 E 3 2546 4600 0 Blue 0
9 AM Mon 47 48 E 3 2546 4600 0 Blue 0
10 AM Mon 56 58 E 3 6564 4600 0 Blue 1
11 AM Mon 57 60 W 4 7786 4600 0 Blue 3
12 Noon Mon 60 64 W 4 8595 7855 3255 Blue 7
1 PM Mon 61 65 W 4 9003 7934 3334 Blue 8
2 PM Mon 59 63 W 4 8181 7777 3177 Blue 6
3 PM Mon 59 62 W 4 7943 7551 2951 Blue 5
4 PM Mon 61 63 W 4 8181 7777 3177 Blue 6
5 PM Mon 57 58 W 5 6564 4600 0 Blue 1
6 PM Mon 55 55 W 5 2765 4600 0 Blue 0
7 PM Mon 54 54 W 5 2546 4600 0 Blue 0
8 PM Mon 52 52 W 5 2546 4600 0 Blue 0
9 PM Mon 49 49 W 5 2546 4600 0 Blue 0
10 PM Mon 48 48 W 5 2546 4600 0 Blue 0
11 PM Mon 48 48 NE 3 2546 4600 0 Blue 0
12 Midnight Tue 47 47 NE 3 2546 4600 0 Blue 0
1 AM Tue 46 46 NE 3 2546 4600 0 Blue 0
2 AM Tue 46 46 NE 3 2546 4600 0 Blue 0
3 AM Tue 46 46 NE 3 2546 4600 0 Blue 0
4 AM Tue 46 46 NE 3 2546 4600 0 Blue 0
5 AM Tue 44 44 SW 1 2546 4600 0 Blue 0
6 AM Tue 42 42 SW 1 2546 4600 0 Blue 0
7 AM Tue 41 41 SW 1 2546 4600 0 Blue 0
8 AM Tue 41 41 SW 1 2546 4600 0 Blue 0
9 AM Tue 44 45 SW 1 2546 4600 0 Blue 0
10 AM Tue 51 53 SW 1 2546 4600 0 Blue 0
11 AM Tue 52 55 SW 6 2765 4600 0 Blue 0
12 Noon Tue 54 58 SW 6 6564 4600 0 Blue 1
1 PM Tue 55 59 SW 6 7586 4600 0 Blue 2
2 PM Tue 53 57 SW 6 4588 4600 0 Blue 0
3 PM Tue 53 56 SW 6 3718 4600 0 Blue 0
4 PM Tue 55 57 SW 6 4588 4600 0 Blue 0
5 PM Tue 51 52 NW 5 2546 4600 0 Blue 0
6 PM Tue 49 49 NW 5 2546 4600 0 Blue 0
7 PM Tue 49 49 NW 5 2546 4600 0 Blue 0
8 PM Tue 46 46 NW 5 2546 4600 0 Blue 0
9 PM Tue 44 44 NW 5 2546 4600 0 Blue 0
10 PM Tue 43 43 NW 5 2546 4600 0 Blue 0
11 PM Tue 42 42 E 5 2546 4600 0 Blue 0
12 Midnight Wed 41 41 E 5 2546 4600 0 Blue 0
1 AM Wed 41 41 E 5 2546 4600 0 Blue 0
2 AM Wed 41 41 E 5 2546 4600 0 Blue 0
3 AM Wed 40 40 E 5 2546 4600 0 Blue 0
4 AM Wed 41 41 E 5 2546 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