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

Station:

KNKX

Date/Time:

25 APR 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 Tue 49 47 N 3 2500 4040 0 Blue 0
6 AM Tue 47 45 N 5 2467 4040 0 Blue 0
7 AM Tue 48 46 N 5 2467 4040 0 Blue 0
8 AM Tue 54 53 NW 8 4240 4040 0 Blue 4
9 AM Tue 59 59 NW 8 5553 4637 597 Blue 10
10 AM Tue 61 62 NW 8 6148 5517 1477 Blue 13
11 AM Tue 64 67 NW 8 6388 6239 2199 Blue 18
12 Noon Tue 66 70 NW 8 6758 6383 2343 Blue 21
1 PM Tue 68 72 NW 7 7010 6616 2576 Blue 23
2 PM Tue 69 72 W 6 7010 6616 2576 Blue 23
3 PM Tue 69 71 W 6 6884 6491 2451 Blue 22
4 PM Tue 70 70 W 6 6758 6383 2343 Blue 21
5 PM Tue 69 68 SW 7 6505 6287 2247 Blue 19
6 PM Tue 67 65 SW 7 6292 6143 2103 Blue 16
7 PM Tue 64 62 SW 6 6148 5517 1477 Blue 13
8 PM Tue 61 59 N 1 5553 4637 597 Blue 10
9 PM Tue 60 58 SE 1 5118 4503 463 Blue 9
10 PM Tue 59 57 E 2 4785 4369 329 Blue 8
11 PM Tue 58 56 N 10 4645 4234 194 Blue 7
12 Midnight Wed 57 55 N 13 4510 4100 60 Blue 6
1 AM Wed 57 55 N 14 4510 4100 60 Blue 6
2 AM Wed 56 54 N 16 4375 4040 0 Blue 5
3 AM Wed 56 54 N 17 4375 4040 0 Blue 5
4 AM Wed 56 54 N 17 4375 4040 0 Blue 5
5 AM Wed 58 56 N 17 4645 4234 194 Blue 7
6 AM Wed 56 54 N 17 4375 4040 0 Blue 5
7 AM Wed 57 55 N 17 4510 4100 60 Blue 6
8 AM Wed 63 62 N 14 6148 5517 1477 Blue 13
9 AM Wed 67 67 N 12 6388 6239 2199 Blue 18
10 AM Wed 69 70 N 8 6758 6383 2343 Blue 21
11 AM Wed 72 75 S 3 7761 6994 2954 Blue 26
12 Noon Wed 74 77 SW 5 8306 7304 3264 Blue 28
1 PM Wed 75 78 SW 5 8444 7699 3659 Blue 29
2 PM Wed 76 79 SW 8 8581 8089 4049 Blue 30
3 PM Wed 76 78 SW 8 8444 7699 3659 Blue 29
4 PM Wed 77 77 SW 8 8306 7304 3264 Blue 28
5 PM Wed 76 75 SW 9 7761 6994 2954 Blue 26
6 PM Wed 73 71 SW 8 6884 6491 2451 Blue 22
7 PM Wed 68 66 SW 6 6340 6191 2151 Blue 17
8 PM Wed 64 62 S 3 6148 5517 1477 Blue 13
9 PM Wed 62 60 SW 2 5902 4774 734 White 11
10 PM Wed 61 59 W 1 5553 4637 597 Blue 10
11 PM Wed 60 58 NW 1 5118 4503 463 Blue 9
12 Midnight Thu 59 57 NW 1 4785 4369 329 Blue 8
1 AM Thu 59 57 N 3 4785 4369 329 Blue 8
2 AM Thu 58 56 N 6 4645 4234 194 Blue 7
3 AM Thu 58 56 N 7 4645 4234 194 Blue 7
4 AM Thu 58 56 N 9 4645 4234 194 Blue 7
5 AM Thu 60 58 N 13 5118 4503 463 Blue 9
6 AM Thu 57 55 N 16 4510 4100 60 Blue 6
7 AM Thu 58 56 N 18 4645 4234 194 Blue 7
8 AM Thu 64 63 N 21 6196 5939 1899 Blue 14
9 AM Thu 68 68 N 18 6505 6287 2247 Blue 19
10 AM Thu 71 72 N 16 7010 6616 2576 Blue 23
11 AM Thu 73 76 N 14 8155 7119 3079 Blue 27
12 Noon Thu 75 79 NW 12 8581 8089 4049 Blue 30
1 PM Thu 77 81 NW 10 8856 8419 4379 Blue 32
2 PM Thu 78 81 NW 9 8856 8419 4379 Blue 32
3 PM Thu 78 80 NW 8 8719 8282 4242 Blue 31
4 PM Thu 78 79 W 8 8581 8089 4049 Blue 30
5 PM Thu 77 76 W 8 8155 7119 3079 Blue 27
6 PM Thu 74 72 NW 9 7010 6616 2576 Blue 23
7 PM Thu 67 65 N 9 6292 6143 2103 Blue 16
8 PM Thu 63 61 N 10 6080 5088 1048 Blue 12
9 PM Thu 60 58 N 12 5118 4503 463 Blue 9
10 PM Thu 59 57 N 13 4785 4369 329 Blue 8
11 PM Thu 57 55 N 14 4510 4100 60 Blue 6
12 Midnight Fri 56 54 N 15 4375 4040 0 Blue 5
1 AM Fri 56 54 N 15 4375 4040 0 Blue 5
2 AM Fri 55 53 N 15 4240 4040 0 Blue 4
3 AM Fri 55 53 N 17 4240 4040 0 Blue 4
4 AM Fri 55 53 N 20 4240 4040 0 Blue 4
5 AM Fri 57 55 NW 22 4510 4100 60 Blue 6
6 AM Fri 54 52 NW 22 4105 4040 0 Blue 3
7 AM Fri 55 53 NW 22 4240 4040 0 Blue 4
8 AM Fri 61 60 NW 22 5902 4774 734 White 11
9 AM Fri 65 65 NW 22 6292 6143 2103 Blue 16
10 AM Fri 68 70 NW 22 6758 6383 2343 Blue 21
11 AM Fri 70 74 NW 13 7362 6868 2828 Blue 25
12 Noon Fri 72 77 NW 13 8306 7304 3264 Blue 28
1 PM Fri 74 79 NW 13 8581 8089 4049 Blue 30
2 PM Fri 75 79 NW 13 8581 8089 4049 Blue 30
3 PM Fri 76 79 NW 13 8581 8089 4049 Blue 30
4 PM Fri 76 77 NW 13 8306 7304 3264 Blue 28
5 PM Fri 74 73 W 10 7137 6742 2702 Blue 24
6 PM Fri 72 70 W 10 6758 6383 2343 Blue 21
7 PM Fri 66 64 W 10 6244 6071 2031 Blue 15
8 PM Fri 62 60 W 10 5902 4774 734 White 11
9 PM Fri 60 58 W 10 5118 4503 463 Blue 9
10 PM Fri 59 57 W 10 4785 4369 329 Blue 8
11 PM Fri 58 56 N 8 4645 4234 194 Blue 7
12 Midnight Sat 57 55 N 8 4510 4100 60 Blue 6
1 AM Sat 57 55 N 8 4510 4100 60 Blue 6
2 AM Sat 56 54 N 8 4375 4040 0 Blue 5
3 AM Sat 56 54 N 8 4375 4040 0 Blue 5
4 AM Sat 56 54 N 8 4375 4040 0 Blue 5
5 AM Sat 58 56 N 17 4645 4234 194 Blue 7
6 AM Sat 55 53 N 17 4240 4040 0 Blue 4
7 AM Sat 56 54 N 17 4375 4040 0 Blue 5
8 AM Sat 61 60 N 17 5902 4774 734 White 11
9 AM Sat 65 66 N 17 6340 6191 2151 Blue 17
10 AM Sat 67 69 N 17 6632 6335 2295 Blue 20
11 AM Sat 69 73 NW 10 7137 6742 2702 Blue 24
12 Noon Sat 71 77 NW 10 8306 7304 3264 Blue 28
1 PM Sat 72 78 NW 10 8444 7699 3659 Blue 29
2 PM Sat 73 78 NW 10 8444 7699 3659 Blue 29
3 PM Sat 74 77 NW 10 8306 7304 3264 Blue 28
4 PM Sat 74 75 NW 10 7761 6994 2954 Blue 26
5 PM Sat 73 73 NW 8 7137 6742 2702 Blue 24
6 PM Sat 70 68 NW 8 6505 6287 2247 Blue 19
7 PM Sat 66 64 NW 8 6244 6071 2031 Blue 15
8 PM Sat 62 60 NW 8 5902 4774 734 White 11
9 PM Sat 60 58 NW 8 5118 4503 463 Blue 9
10 PM Sat 59 57 NW 8 4785 4369 329 Blue 8
11 PM Sat 58 56 N 6 4645 4234 194 Blue 7
12 Midnight Sun 58 56 N 6 4645 4234 194 Blue 7
1 AM Sun 58 56 N 6 4645 4234 194 Blue 7
2 AM Sun 57 55 N 6 4510 4100 60 Blue 6
3 AM Sun 56 54 N 6 4375 4040 0 Blue 5
4 AM Sun 57 55 N 6 4510 4100 60 Blue 6
5 AM Sun 58 56 N 12 4645 4234 194 Blue 7
6 AM Sun 56 54 N 12 4375 4040 0 Blue 5
7 AM Sun 57 55 N 12 4510 4100 60 Blue 6
8 AM Sun 63 62 N 12 6148 5517 1477 Blue 13
9 AM Sun 68 69 N 12 6632 6335 2295 Blue 20
10 AM Sun 70 73 N 12 7137 6742 2702 Blue 24
11 AM Sun 73 77 NW 8 8306 7304 3264 Blue 28
12 Noon Sun 75 80 NW 8 8719 8282 4242 Blue 31
1 PM Sun 77 82 NW 8 8994 8556 4516 Blue 33
2 PM Sun 78 82 NW 8 8994 8556 4516 Blue 33
3 PM Sun 79 82 NW 8 8994 8556 4516 Blue 33
4 PM Sun 79 80 NW 8 8719 8282 4242 Blue 31
5 PM Sun 77 76 W 9 8155 7119 3079 Blue 27
6 PM Sun 74 72 W 9 7010 6616 2576 Blue 23
7 PM Sun 69 67 W 9 6388 6239 2199 Blue 18
8 PM Sun 64 62 W 9 6148 5517 1477 Blue 13
9 PM Sun 62 60 W 9 5902 4774 734 White 11
10 PM Sun 61 59 W 9 5553 4637 597 Blue 10
11 PM Sun 60 58 N 6 5118 4503 463 Blue 9
12 Midnight Mon 59 57 N 6 4785 4369 329 Blue 8
1 AM Mon 59 57 N 6 4785 4369 329 Blue 8
2 AM Mon 58 56 N 6 4645 4234 194 Blue 7
3 AM Mon 58 56 N 6 4645 4234 194 Blue 7
4 AM Mon 58 56 N 6 4645 4234 194 Blue 7

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