Detailed Predictions for: Marshall
Launch Altitude (f): 4040
LZ Altitude (f): 1700
Sounding

Station:

KNKX

Date/Time:

12Z 21 AUG 2017

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 Mon -999 -1001 - 2851 4040 0 Blue 0
6 AM Mon -999 -1001 - 2851 4040 0 Blue 0
7 AM Mon -999 -1000 - 2851 4040 0 Blue 0
8 AM Mon 66 64 S 1 3105 4040 0 Blue 6
9 AM Mon 70 70 S 1 3351 4040 0 Blue 12
10 AM Mon 72 74 S 2 3890 4040 0 Blue 16
11 AM Mon 75 78 SW 3 4581 4040 0 Blue 20
12 Noon Mon 79 83 SW 5 6849 5743 1703 Blue 25
1 PM Mon 81 86 SW 5 8997 6806 2766 Blue 28
2 PM Mon 82 86 SW 6 8997 6806 2766 Blue 28
3 PM Mon 82 85 SW 7 8683 6458 2418 Blue 27
4 PM Mon 82 83 SW 7 6849 5743 1703 Blue 25
5 PM Mon 81 81 SW 8 6141 4543 503 Blue 23
6 PM Mon 80 78 SW 8 4581 4040 0 Blue 20
7 PM Mon 74 72 SW 7 3612 4040 0 Blue 14
8 PM Mon 71 69 S 2 3246 4040 0 Blue 11
9 PM Mon 68 66 S 2 3149 4040 0 Blue 8
10 PM Mon 67 65 SE 1 3127 4040 0 Blue 7
11 PM Mon 65 63 E 1 3083 4040 0 Blue 5
12 Midnight Tue 64 62 E 1 3061 4040 0 Blue 4
1 AM Tue 63 61 NE 2 3039 4040 0 Blue 3
2 AM Tue 62 60 NE 2 3017 4040 0 Blue 2
3 AM Tue 62 60 NE 2 3017 4040 0 Blue 2
4 AM Tue 61 59 NE 2 2995 4040 0 Blue 1
5 AM Tue 61 59 NE 2 2995 4040 0 Blue 1
6 AM Tue 61 59 NE 2 2995 4040 0 Blue 1
7 AM Tue 63 61 NE 2 3039 4040 0 Blue 3
8 AM Tue 71 69 SE 0 3246 4040 0 Blue 11
9 AM Tue 76 76 S 0 4136 4040 0 Blue 18
10 AM Tue 78 80 S 1 5775 4282 242 Blue 22
11 AM Tue 81 85 SW 3 8683 6458 2418 Blue 27
12 Noon Tue 84 89 SW 3 10009 8938 4898 Blue 31
1 PM Tue 86 91 SW 3 10688 9604 5564 Blue 33
2 PM Tue 88 93 SW 7 11447 10262 6222 White 35
3 PM Tue 88 92 SW 7 11238 9934 5894 White 34
4 PM Tue 88 90 SW 7 10340 9269 5229 Blue 32
5 PM Tue 86 86 SW 8 8997 6806 2766 Blue 28
6 PM Tue 85 83 SW 8 6849 5743 1703 Blue 25
7 PM Tue 78 76 SW 7 4136 4040 0 Blue 18
8 PM Tue 74 72 SE 2 3612 4040 0 Blue 14
9 PM Tue 71 69 SE 2 3246 4040 0 Blue 11
10 PM Tue 69 67 SE 2 3177 4040 0 Blue 9
11 PM Tue 67 65 E 1 3127 4040 0 Blue 7
12 Midnight Wed 66 64 E 1 3105 4040 0 Blue 6
1 AM Wed 64 62 E 1 3061 4040 0 Blue 4
2 AM Wed 64 62 N 1 3061 4040 0 Blue 4
3 AM Wed 63 61 N 1 3039 4040 0 Blue 3
4 AM Wed 62 60 N 1 3017 4040 0 Blue 2
5 AM Wed 62 60 N 2 3017 4040 0 Blue 2
6 AM Wed 62 60 N 2 3017 4040 0 Blue 2
7 AM Wed 63 61 N 1 3039 4040 0 Blue 3
8 AM Wed 71 69 W 1 3246 4040 0 Blue 11
9 AM Wed 75 75 W 1 4006 4040 0 Blue 17
10 AM Wed 77 79 SW 1 5327 4132 92 Blue 21
11 AM Wed 79 83 SW 3 6849 5743 1703 Blue 25
12 Noon Wed 82 87 SW 3 9338 7371 3331 Blue 29
1 PM Wed 84 89 SW 3 10009 8938 4898 Blue 31
2 PM Wed 85 90 SW 7 10340 9269 5229 Blue 32
3 PM Wed 85 88 SW 7 9675 8600 4560 Blue 30
4 PM Wed 85 87 SW 7 9338 7371 3331 Blue 29
5 PM Wed 84 84 SW 8 7551 6106 2066 Blue 26
6 PM Wed 82 80 SW 7 5775 4282 242 Blue 22
7 PM Wed 76 74 SW 7 3890 4040 0 Blue 16
8 PM Wed 73 71 S 2 3448 4040 0 Blue 13
9 PM Wed 70 68 SW 1 3211 4040 0 Blue 10
10 PM Wed 68 66 S 0 3149 4040 0 Blue 8
11 PM Wed 67 65 E 1 3127 4040 0 Blue 7
12 Midnight Thu 65 63 N 1 3083 4040 0 Blue 5
1 AM Thu 64 62 S 0 3061 4040 0 Blue 4
2 AM Thu 63 61 NE 2 3039 4040 0 Blue 3
3 AM Thu 63 61 NE 2 3039 4040 0 Blue 3
4 AM Thu 62 60 NE 2 3017 4040 0 Blue 2
5 AM Thu 62 60 N 5 3017 4040 0 Blue 2
6 AM Thu 62 60 N 5 3017 4040 0 Blue 2
7 AM Thu 64 62 N 5 3061 4040 0 Blue 4
8 AM Thu 72 70 N 8 3351 4040 0 Blue 12
9 AM Thu 76 76 N 8 4136 4040 0 Blue 18
10 AM Thu 78 80 N 8 5775 4282 242 Blue 22
11 AM Thu 80 83 SW 3 6849 5743 1703 Blue 25
12 Noon Thu 84 88 SW 3 9675 8600 4560 Blue 30
1 PM Thu 86 91 SW 3 10688 9604 5564 Blue 33
2 PM Thu 87 91 SW 8 10688 9604 5564 Blue 33
3 PM Thu 88 91 SW 8 10688 9604 5564 Blue 33
4 PM Thu 87 88 SW 8 9675 8600 4560 Blue 30
5 PM Thu 86 86 SW 8 8997 6806 2766 Blue 28
6 PM Thu 84 82 SW 8 6497 5279 1239 Blue 24
7 PM Thu 79 77 SW 8 4289 4040 0 Blue 19
8 PM Thu 76 74 S 0 3890 4040 0 Blue 16
9 PM Thu 72 70 S 0 3351 4040 0 Blue 12
10 PM Thu 71 69 S 0 3246 4040 0 Blue 11
11 PM Thu 70 68 N 1 3211 4040 0 Blue 10
12 Midnight Fri 68 66 N 1 3149 4040 0 Blue 8
1 AM Fri 67 65 N 1 3127 4040 0 Blue 7
2 AM Fri 66 64 N 7 3105 4040 0 Blue 6
3 AM Fri 66 64 N 7 3105 4040 0 Blue 6
4 AM Fri 65 63 N 7 3083 4040 0 Blue 5
5 AM Fri 65 63 N 10 3083 4040 0 Blue 5
6 AM Fri 65 63 N 10 3083 4040 0 Blue 5
7 AM Fri 67 65 N 10 3127 4040 0 Blue 7
8 AM Fri 76 74 N 10 3890 4040 0 Blue 16
9 AM Fri 80 80 N 10 5775 4282 242 Blue 22
10 AM Fri 83 85 N 10 8683 6458 2418 Blue 27
11 AM Fri 86 89 S 3 10009 8938 4898 Blue 31
12 Noon Fri 89 93 S 3 11447 10262 6222 White 35
1 PM Fri 92 97 S 3 12275 12275 8235 White 39
2 PM Fri 93 97 S 8 12275 12275 8235 White 39
3 PM Fri 94 97 S 8 12275 12275 8235 White 39
4 PM Fri 93 94 S 8 11654 10602 6562 White 36
5 PM Fri 92 92 SW 9 11238 9934 5894 White 34
6 PM Fri 90 88 SW 9 9675 8600 4560 Blue 30
7 PM Fri 83 81 SW 9 6141 4543 503 Blue 23
8 PM Fri 79 77 SE 1 4289 4040 0 Blue 19
9 PM Fri 76 74 SE 1 3890 4040 0 Blue 16
10 PM Fri 74 72 SE 1 3612 4040 0 Blue 14
11 PM Fri 72 70 NE 1 3351 4040 0 Blue 12
12 Midnight Sat 71 69 NE 1 3246 4040 0 Blue 11
1 AM Sat 70 68 NE 1 3211 4040 0 Blue 10
2 AM Sat 68 66 NE 7 3149 4040 0 Blue 8
3 AM Sat 68 66 NE 7 3149 4040 0 Blue 8
4 AM Sat 67 65 NE 7 3127 4040 0 Blue 7
5 AM Sat 67 65 NE 9 3127 4040 0 Blue 7
6 AM Sat 67 65 NE 9 3127 4040 0 Blue 7
7 AM Sat 69 67 NE 9 3177 4040 0 Blue 9
8 AM Sat 77 75 NE 9 4006 4040 0 Blue 17
9 AM Sat 82 82 NE 9 6497 5279 1239 Blue 24
10 AM Sat 84 86 NE 9 8997 6806 2766 Blue 28
11 AM Sat 87 91 S 5 10688 9604 5564 Blue 33
12 Noon Sat 90 95 S 5 11861 10944 6904 White 37
1 PM Sat 92 97 S 5 12275 12275 8235 White 39
2 PM Sat 94 99 S 9 12688 12688 8648 White 41
3 PM Sat 95 98 S 9 12482 12482 8442 White 40
4 PM Sat 92 94 S 9 11654 10602 6562 White 36
5 PM Sat 88 88 SW 8 9675 8600 4560 Blue 30
6 PM Sat 82 80 SW 8 5775 4282 242 Blue 22
7 PM Sat 64 62 SW 8 3061 4040 0 Blue 4
8 PM Sat 52 50 SE 5 2851 4040 0 Blue 0
9 PM Sat 41 39 SE 5 2851 4040 0 Blue 0
10 PM Sat 36 34 SE 5 2851 4040 0 Blue 0
11 PM Sat 31 29 E 1 2851 4040 0 Blue 0
12 Midnight Sun 27 25 E 1 2851 4040 0 Blue 0
1 AM Sun 23 21 E 1 2851 4040 0 Blue 0
2 AM Sun 20 18 N 6 2851 4040 0 Blue 0
3 AM Sun 19 17 N 6 2851 4040 0 Blue 0
4 AM Sun 17 15 N 6 2851 4040 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