Detailed Predictions for: Merriam Crater
Launch Altitude (f): 6800
LZ Altitude (f): 6000
Sounding

Station:

KFGZ

Date/Time:

20 AUG 2019

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)
6 AM Tue 66 66 W 3 7362 7325 525 Blue 17
7 AM Tue 66 66 W 5 7362 7325 525 Blue 17
8 AM Tue 68 69 SW 5 7399 7361 561 Blue 20
9 AM Tue 71 74 S 6 7455 7423 623 Blue 25
10 AM Tue 75 80 SE 7 9336 7829 1029 Blue 31
11 AM Tue 79 86 E 7 15170 10964 4164 Blue 37
12 Noon Tue 83 91 E 8 18206 17653 10853 Blue 42
1 PM Tue 86 94 E 8 19659 18113 11313 Blue 45
2 PM Tue 90 97 SE 8 21664 19417 12617 Blue 48
3 PM Tue 92 97 S 8 21664 19417 12617 Blue 48
4 PM Tue 94 97 SW 9 21664 19417 12617 Blue 48
5 PM Tue 95 96 SW 9 21502 18592 11792 Blue 47
6 PM Tue 94 94 W 9 19659 18113 11313 Blue 45
7 PM Tue 92 92 W 10 18437 17751 10951 Blue 43
8 PM Tue 89 89 W 10 17790 14987 8187 Blue 40
9 PM Tue 85 85 W 12 11728 10340 3540 Blue 36
10 PM Tue 82 82 W 12 10410 8726 1926 Blue 33
11 PM Tue 79 79 W 12 8774 7620 820 Blue 30
12 Midnight Wed 76 76 W 12 7630 7444 644 Blue 27
1 AM Wed 75 75 W 10 7465 7434 634 Blue 26
2 AM Wed 74 74 W 9 7455 7423 623 Blue 25
3 AM Wed 72 72 W 8 7434 7398 598 Blue 23
4 AM Wed 69 69 W 6 7399 7361 561 Blue 20
5 AM Wed 67 67 W 5 7374 7337 537 Blue 18
6 AM Wed 65 65 W 3 7350 7312 512 Blue 16
7 AM Wed 66 66 W 3 7362 7325 525 Blue 17
8 AM Wed 68 69 SW 5 7399 7361 561 Blue 20
9 AM Wed 72 75 SW 5 7465 7434 634 Blue 26
10 AM Wed 77 82 SW 6 10410 8726 1926 Blue 33
11 AM Wed 82 88 SW 8 17691 11669 4869 Blue 39
12 Noon Wed 86 93 SW 9 18909 17883 11083 Blue 44
1 PM Wed 89 96 SW 10 21502 18592 11792 Blue 47
2 PM Wed 91 97 SW 12 21664 19417 12617 Blue 48
3 PM Wed 93 98 SW 13 21991 19889 13089 Blue 49
4 PM Wed 95 98 SW 14 21991 19889 13089 Blue 49
5 PM Wed 96 97 SW 15 21664 19417 12617 Blue 48
6 PM Wed 95 95 SW 15 20089 18342 11542 Blue 46
7 PM Wed 93 93 SW 16 18909 17883 11083 Blue 44
8 PM Wed 89 89 SW 16 17790 14987 8187 Blue 40
9 PM Wed 85 85 SW 16 11728 10340 3540 Blue 36
10 PM Wed 82 82 SW 16 10410 8726 1926 Blue 33
11 PM Wed 80 80 SW 16 9336 7829 1029 Blue 31
12 Midnight Thu 78 78 SW 15 8193 7464 664 Blue 29
1 AM Thu 76 76 SW 15 7630 7444 644 Blue 27
2 AM Thu 74 74 W 13 7455 7423 623 Blue 25
3 AM Thu 72 72 W 12 7434 7398 598 Blue 23
4 AM Thu 69 69 W 10 7399 7361 561 Blue 20
5 AM Thu 66 66 W 9 7362 7325 525 Blue 17
6 AM Thu 65 65 W 8 7350 7312 512 Blue 16
7 AM Thu 66 66 W 9 7362 7325 525 Blue 17
8 AM Thu 69 70 W 9 7411 7374 574 Blue 21
9 AM Thu 73 76 SW 10 7630 7444 644 Blue 27
10 AM Thu 77 82 SW 12 10410 8726 1926 Blue 33
11 AM Thu 81 88 SW 12 17691 11669 4869 Blue 39
12 Noon Thu 85 93 SW 13 18909 17883 11083 Blue 44
1 PM Thu 88 96 SW 14 21502 18592 11792 Blue 47
2 PM Thu 91 98 SW 15 21991 19889 13089 Blue 49
3 PM Thu 93 98 SW 16 21991 19889 13089 Blue 49
4 PM Thu 94 97 SW 16 21664 19417 12617 Blue 48
5 PM Thu 94 95 SW 17 20089 18342 11542 Blue 46
6 PM Thu 93 93 W 17 18909 17883 11083 Blue 44
7 PM Thu 90 90 W 16 17974 15593 8793 Blue 41
8 PM Thu 86 86 W 15 15170 10964 4164 Blue 37
9 PM Thu 83 83 W 14 11020 9280 2480 Blue 34
10 PM Thu 80 80 W 13 9336 7829 1029 Blue 31
11 PM Thu 78 78 W 12 8193 7464 664 Blue 29
12 Midnight Fri 77 77 W 10 7840 7454 654 Blue 28
1 AM Fri 75 75 W 9 7465 7434 634 Blue 26
2 AM Fri 73 73 W 9 7444 7410 610 Blue 24
3 AM Fri 71 71 SW 8 7423 7386 586 Blue 22
4 AM Fri 68 68 SW 8 7386 7349 549 Blue 19
5 AM Fri 66 66 SW 7 7362 7325 525 Blue 17
6 AM Fri 65 65 SW 7 7350 7312 512 Blue 16
7 AM Fri 67 67 SW 7 7374 7337 537 Blue 18
8 AM Fri 69 70 SW 6 7411 7374 574 Blue 21
9 AM Fri 72 74 SW 6 7455 7423 623 Blue 25
10 AM Fri 72 75 W 6 7465 7434 634 Blue 26
11 AM Fri 73 77 W 5 7840 7454 654 Blue 28
12 Noon Fri 76 81 W 5 9881 8154 1354 Blue 32
1 PM Fri 83 87 W 6 15780 11320 4520 Blue 38
2 PM Fri 89 92 SW 6 18437 17751 10951 Blue 43
3 PM Fri 91 93 SW 6 18909 17883 11083 Blue 44
4 PM Fri 87 88 SW 7 17691 11669 4869 Blue 39
5 PM Fri 79 79 SW 7 8774 7620 820 Blue 30
6 PM Fri 74 74 SW 8 7455 7423 623 Blue 25
7 PM Fri 74 74 SW 8 7455 7423 623 Blue 25
8 PM Fri 77 77 SW 9 7840 7454 654 Blue 28
9 PM Fri 80 80 SW 9 9336 7829 1029 Blue 31
10 PM Fri 79 79 W 9 8774 7620 820 Blue 30
11 PM Fri 76 76 W 9 7630 7444 644 Blue 27
12 Midnight Sat 72 72 W 9 7434 7398 598 Blue 23
1 AM Sat 70 70 W 9 7411 7374 574 Blue 21
2 AM Sat 69 69 W 8 7399 7361 561 Blue 20
3 AM Sat 68 68 W 8 7386 7349 549 Blue 19
4 AM Sat 67 67 W 7 7374 7337 537 Blue 18
5 AM Sat 66 66 W 7 7362 7325 525 Blue 17
6 AM Sat 66 66 W 6 7362 7325 525 Blue 17
7 AM Sat 67 67 W 6 7374 7337 537 Blue 18
8 AM Sat 69 70 W 6 7411 7374 574 Blue 21
9 AM Sat 70 73 W 6 7444 7410 610 Blue 24
10 AM Sat 72 76 W 6 7630 7444 644 Blue 27
11 AM Sat 74 79 NW 6 8774 7620 820 Blue 30
12 Noon Sat 78 84 NW 6 11379 9817 3017 Blue 35
1 PM Sat 83 88 NW 6 17691 11669 4869 Blue 39
2 PM Sat 88 93 NW 5 18909 17883 11083 Blue 44
3 PM Sat 91 94 W 5 19659 18113 11313 Blue 45
4 PM Sat 91 93 W 5 18909 17883 11083 Blue 44
5 PM Sat 89 90 W 5 17974 15593 8793 Blue 41
6 PM Sat 86 86 W 6 15170 10964 4164 Blue 37
7 PM Sat 84 84 W 6 11379 9817 3017 Blue 35
8 PM Sat 83 83 W 7 11020 9280 2480 Blue 34
9 PM Sat 80 80 W 8 9336 7829 1029 Blue 31
10 PM Sat 76 76 W 9 7630 7444 644 Blue 27
11 PM Sat 71 71 W 9 7423 7386 586 Blue 22
12 Midnight Sun 68 68 W 10 7386 7349 549 Blue 19
1 AM Sun 66 66 W 10 7362 7325 525 Blue 17
2 AM Sun 66 66 W 10 7362 7325 525 Blue 17
3 AM Sun 66 66 W 9 7362 7325 525 Blue 17
4 AM Sun 66 66 W 9 7362 7325 525 Blue 17
5 AM Sun 66 66 W 9 7362 7325 525 Blue 17
6 AM Sun 66 66 W 8 7362 7325 525 Blue 17
7 AM Sun 67 67 W 7 7374 7337 537 Blue 18
8 AM Sun 69 70 W 7 7411 7374 574 Blue 21
9 AM Sun 71 74 W 6 7455 7423 623 Blue 25
10 AM Sun 73 78 W 5 8193 7464 664 Blue 29
11 AM Sun 75 81 W 5 9881 8154 1354 Blue 32
12 Noon Sun 79 86 W 5 15170 10964 4164 Blue 37
1 PM Sun 84 91 W 5 18206 17653 10853 Blue 42
2 PM Sun 89 95 W 6 20089 18342 11542 Blue 46
3 PM Sun 92 96 W 7 21502 18592 11792 Blue 47
4 PM Sun 92 94 W 8 19659 18113 11313 Blue 45
5 PM Sun 89 90 W 9 17974 15593 8793 Blue 41
6 PM Sun 86 86 W 10 15170 10964 4164 Blue 37
7 PM Sun 84 84 W 12 11379 9817 3017 Blue 35
8 PM Sun 82 82 W 12 10410 8726 1926 Blue 33
9 PM Sun 80 80 W 12 9336 7829 1029 Blue 31
10 PM Sun 77 77 W 12 7840 7454 654 Blue 28
11 PM Sun 74 74 W 12 7455 7423 623 Blue 25
12 Midnight Mon 71 71 W 10 7423 7386 586 Blue 22
1 AM Mon 68 68 W 10 7386 7349 549 Blue 19
2 AM Mon 67 67 W 9 7374 7337 537 Blue 18
3 AM Mon 66 66 W 8 7362 7325 525 Blue 17
4 AM Mon 66 66 W 8 7362 7325 525 Blue 17
5 AM Mon 67 67 W 7 7374 7337 537 Blue 18

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