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

Station:

KFGZ

Date/Time:

29 NOV 2020

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 Sun 21 21 NW 3 7195 7162 362 Blue 4
6 AM Sun 22 22 NW 3 7205 7173 373 Blue 5
7 AM Sun 21 21 NW 3 7195 7162 362 Blue 4
8 AM Sun 25 25 NW 3 7235 7205 405 Blue 8
9 AM Sun 33 33 N 3 7313 7283 483 Blue 16
10 AM Sun 37 38 N 5 7361 7332 532 Blue 21
11 AM Sun 39 41 N 6 7391 7361 561 Blue 24
12 Noon Sun 43 45 N 7 7434 7400 600 Blue 28
1 PM Sun 45 47 N 7 7459 7421 621 Blue 30
2 PM Sun 47 49 N 7 7484 7446 646 Blue 32
3 PM Sun 47 48 NE 6 7472 7433 633 Blue 31
4 PM Sun 48 48 NE 6 7472 7433 633 Blue 31
5 PM Sun 43 43 NE 5 7410 7381 581 Blue 26
6 PM Sun 38 38 N 3 7361 7332 532 Blue 21
7 PM Sun 35 35 NW 5 7332 7303 503 Blue 18
8 PM Sun 33 33 NW 6 7313 7283 483 Blue 16
9 PM Sun 32 32 NW 7 7303 7274 474 Blue 15
10 PM Sun 31 31 NW 7 7293 7264 464 Blue 14
11 PM Sun 30 30 NW 6 7284 7254 454 Blue 13
12 Midnight Mon 29 29 NW 6 7274 7245 445 Blue 12
1 AM Mon 28 28 NW 5 7264 7235 435 Blue 11
2 AM Mon 26 26 NW 5 7245 7215 415 Blue 9
3 AM Mon 25 25 NW 5 7235 7205 405 Blue 8
4 AM Mon 24 24 N 3 7225 7194 394 Blue 7
5 AM Mon 23 23 N 3 7216 7184 384 Blue 6
6 AM Mon 22 22 NW 2 7205 7173 373 Blue 5
7 AM Mon 22 22 NW 2 7205 7173 373 Blue 5
8 AM Mon 26 26 W 2 7245 7215 415 Blue 9
9 AM Mon 33 33 E 2 7313 7283 483 Blue 16
10 AM Mon 36 37 E 3 7352 7322 522 Blue 20
11 AM Mon 39 41 E 5 7391 7361 561 Blue 24
12 Noon Mon 42 44 NE 5 7421 7390 590 Blue 27
1 PM Mon 44 46 NE 5 7446 7410 610 Blue 29
2 PM Mon 45 46 NE 6 7446 7410 610 Blue 29
3 PM Mon 45 46 NE 5 7446 7410 610 Blue 29
4 PM Mon 44 44 NE 5 7421 7390 590 Blue 27
5 PM Mon 42 42 NE 3 7400 7371 571 Blue 25
6 PM Mon 38 38 N 2 7361 7332 532 Blue 21
7 PM Mon 34 34 W 2 7323 7293 493 Blue 17
8 PM Mon 31 31 W 3 7293 7264 464 Blue 14
9 PM Mon 29 29 SW 3 7274 7245 445 Blue 12
10 PM Mon 29 29 SW 5 7274 7245 445 Blue 12
11 PM Mon 29 29 SW 3 7274 7245 445 Blue 12
12 Midnight Tue 29 29 SW 3 7274 7245 445 Blue 12
1 AM Tue 27 27 W 2 7255 7225 425 Blue 10
2 AM Tue 26 26 NW 3 7245 7215 415 Blue 9
3 AM Tue 24 24 NW 3 7225 7194 394 Blue 7
4 AM Tue 23 23 NW 2 7216 7184 384 Blue 6
5 AM Tue 23 23 NW 3 7216 7184 384 Blue 6
6 AM Tue 24 24 NW 3 7225 7194 394 Blue 7
7 AM Tue 25 25 NW 3 7235 7205 405 Blue 8
8 AM Tue 28 28 N 5 7264 7235 435 Blue 11
9 AM Tue 32 32 N 6 7303 7274 474 Blue 15
10 AM Tue 37 38 N 7 7361 7332 532 Blue 21
11 AM Tue 41 43 N 8 7410 7381 581 Blue 26
12 Noon Tue 45 47 N 9 7459 7421 621 Blue 30
1 PM Tue 47 49 N 10 7484 7446 646 Blue 32
2 PM Tue 48 50 N 10 7504 7458 658 Blue 33
3 PM Tue 48 49 N 10 7484 7446 646 Blue 32
4 PM Tue 46 46 N 10 7446 7410 610 Blue 29
5 PM Tue 44 44 N 10 7421 7390 590 Blue 27
6 PM Tue 40 40 N 9 7381 7351 551 Blue 23
7 PM Tue 35 35 N 9 7332 7303 503 Blue 18
8 PM Tue 32 32 N 8 7303 7274 474 Blue 15
9 PM Tue 31 31 N 8 7293 7264 464 Blue 14
10 PM Tue 30 30 N 8 7284 7254 454 Blue 13
11 PM Tue 30 30 N 8 7284 7254 454 Blue 13
12 Midnight Wed 29 29 N 7 7274 7245 445 Blue 12
1 AM Wed 28 28 N 7 7264 7235 435 Blue 11
2 AM Wed 26 26 N 7 7245 7215 415 Blue 9
3 AM Wed 25 25 N 7 7235 7205 405 Blue 8
4 AM Wed 24 24 N 7 7225 7194 394 Blue 7
5 AM Wed 23 23 N 7 7216 7184 384 Blue 6
6 AM Wed 23 23 N 7 7216 7184 384 Blue 6
7 AM Wed 24 24 N 6 7225 7194 394 Blue 7
8 AM Wed 25 25 N 6 7235 7205 405 Blue 8
9 AM Wed 28 28 N 7 7264 7235 435 Blue 11
10 AM Wed 31 32 N 8 7303 7274 474 Blue 15
11 AM Wed 35 37 N 9 7352 7322 522 Blue 20
12 Noon Wed 38 40 N 10 7381 7351 551 Blue 23
1 PM Wed 41 43 N 12 7410 7381 581 Blue 26
2 PM Wed 43 45 N 13 7434 7400 600 Blue 28
3 PM Wed 43 44 N 13 7421 7390 590 Blue 27
4 PM Wed 42 42 N 12 7400 7371 571 Blue 25
5 PM Wed 39 39 N 12 7371 7342 542 Blue 22
6 PM Wed 35 35 N 13 7332 7303 503 Blue 18
7 PM Wed 31 31 N 13 7293 7264 464 Blue 14
8 PM Wed 28 28 N 14 7264 7235 435 Blue 11
9 PM Wed 27 27 N 14 7255 7225 425 Blue 10
10 PM Wed 27 27 N 13 7255 7225 425 Blue 10
11 PM Wed 27 27 N 12 7255 7225 425 Blue 10
12 Midnight Thu 26 26 N 12 7245 7215 415 Blue 9
1 AM Thu 25 25 N 10 7235 7205 405 Blue 8
2 AM Thu 23 23 N 10 7216 7184 384 Blue 6
3 AM Thu 22 22 N 10 7205 7173 373 Blue 5
4 AM Thu 20 20 N 9 7184 7152 352 Blue 3
5 AM Thu 19 19 N 9 7173 7149 349 Blue 2
6 AM Thu 19 19 N 8 7173 7149 349 Blue 2
7 AM Thu 19 19 N 8 7173 7149 349 Blue 2
8 AM Thu 21 21 N 8 7195 7162 362 Blue 4
9 AM Thu 23 23 N 9 7216 7184 384 Blue 6
10 AM Thu 27 28 N 10 7264 7235 435 Blue 11
11 AM Thu 31 33 NE 12 7313 7283 483 Blue 16
12 Noon Thu 34 36 NE 13 7342 7312 512 Blue 19
1 PM Thu 37 39 NE 13 7371 7342 542 Blue 22
2 PM Thu 39 41 NE 13 7391 7361 561 Blue 24
3 PM Thu 40 41 NE 12 7391 7361 561 Blue 24
4 PM Thu 39 39 N 12 7371 7342 542 Blue 22
5 PM Thu 37 37 N 10 7352 7322 522 Blue 20
6 PM Thu 34 34 N 10 7323 7293 493 Blue 17
7 PM Thu 31 31 N 10 7293 7264 464 Blue 14
8 PM Thu 29 29 N 10 7274 7245 445 Blue 12
9 PM Thu 27 27 N 10 7255 7225 425 Blue 10
10 PM Thu 27 27 N 10 7255 7225 425 Blue 10
11 PM Thu 26 26 N 9 7245 7215 415 Blue 9
12 Midnight Fri 26 26 N 8 7245 7215 415 Blue 9
1 AM Fri 25 25 N 7 7235 7205 405 Blue 8
2 AM Fri 23 23 N 6 7216 7184 384 Blue 6
3 AM Fri 22 22 N 6 7205 7173 373 Blue 5
4 AM Fri 21 21 N 6 7195 7162 362 Blue 4
5 AM Fri 20 20 N 6 7184 7152 352 Blue 3
6 AM Fri 20 20 N 6 7184 7152 352 Blue 3
7 AM Fri 22 22 N 6 7205 7173 373 Blue 5
8 AM Fri 24 24 N 6 7225 7194 394 Blue 7
9 AM Fri 28 28 N 7 7264 7235 435 Blue 11
10 AM Fri 32 33 N 8 7313 7283 483 Blue 16
11 AM Fri 36 38 NE 9 7361 7332 532 Blue 21
12 Noon Fri 40 42 NE 10 7400 7371 571 Blue 25
1 PM Fri 42 44 NE 12 7421 7390 590 Blue 27
2 PM Fri 44 46 NE 12 7446 7410 610 Blue 29
3 PM Fri 44 45 NE 10 7434 7400 600 Blue 28
4 PM Fri 43 43 N 9 7410 7381 581 Blue 26
5 PM Fri 40 40 N 8 7381 7351 551 Blue 23
6 PM Fri 37 37 N 8 7352 7322 522 Blue 20
7 PM Fri 33 33 N 8 7313 7283 483 Blue 16
8 PM Fri 30 30 N 8 7284 7254 454 Blue 13
9 PM Fri 29 29 N 8 7274 7245 445 Blue 12
10 PM Fri 29 29 N 9 7274 7245 445 Blue 12
11 PM Fri 29 29 N 9 7274 7245 445 Blue 12
12 Midnight Sat 28 28 N 9 7264 7235 435 Blue 11
1 AM Sat 27 27 N 8 7255 7225 425 Blue 10
2 AM Sat 25 25 NW 7 7235 7205 405 Blue 8
3 AM Sat 24 24 N 7 7225 7194 394 Blue 7
4 AM Sat 23 23 N 6 7216 7184 384 Blue 6

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