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

Station:

KFGZ

Date/Time:

1 DEC 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 Tue 26 26 NW 0 7217 7198 398 Blue 9
6 AM Tue 26 26 NW 0 7217 7198 398 Blue 9
7 AM Tue 26 26 W 1 7217 7198 398 Blue 9
8 AM Tue 30 30 W 2 7240 7222 422 Blue 13
9 AM Tue 36 36 NW 5 7276 7258 458 Blue 19
10 AM Tue 39 40 N 8 7300 7282 482 Blue 23
11 AM Tue 41 43 N 12 7321 7300 500 Blue 26
12 Noon Tue 44 46 N 15 7371 7320 520 Blue 29
1 PM Tue 46 48 N 16 7520 7339 539 Blue 31
2 PM Tue 47 49 N 17 7595 7368 568 Blue 32
3 PM Tue 47 48 N 16 7520 7339 539 Blue 31
4 PM Tue 46 46 N 15 7371 7320 520 Blue 29
5 PM Tue 43 43 N 13 7321 7300 500 Blue 26
6 PM Tue 37 37 N 12 7282 7264 464 Blue 20
7 PM Tue 34 34 NW 10 7264 7246 446 Blue 17
8 PM Tue 32 32 NW 9 7252 7234 434 Blue 15
9 PM Tue 31 31 NW 8 7246 7228 428 Blue 14
10 PM Tue 29 29 NW 7 7234 7216 416 Blue 12
11 PM Tue 28 28 NW 7 7228 7210 410 Blue 11
12 Midnight Wed 28 28 NW 6 7228 7210 410 Blue 11
1 AM Wed 27 27 NW 5 7222 7204 404 Blue 10
2 AM Wed 26 26 NW 5 7217 7198 398 Blue 9
3 AM Wed 25 25 NW 5 7211 7192 392 Blue 8
4 AM Wed 23 23 NW 5 7199 7180 380 Blue 6
5 AM Wed 22 22 NW 6 7193 7169 369 Blue 5
6 AM Wed 22 22 NW 6 7193 7169 369 Blue 5
7 AM Wed 21 21 NW 6 7187 7158 358 Blue 4
8 AM Wed 26 26 NW 7 7217 7198 398 Blue 9
9 AM Wed 31 31 N 8 7246 7228 428 Blue 14
10 AM Wed 34 35 N 9 7270 7252 452 Blue 18
11 AM Wed 35 37 N 9 7282 7264 464 Blue 20
12 Noon Wed 37 39 N 10 7294 7276 476 Blue 22
1 PM Wed 39 41 N 12 7306 7288 488 Blue 24
2 PM Wed 40 42 N 13 7312 7294 494 Blue 25
3 PM Wed 40 41 N 12 7306 7288 488 Blue 24
4 PM Wed 39 39 N 12 7294 7276 476 Blue 22
5 PM Wed 37 37 N 10 7282 7264 464 Blue 20
6 PM Wed 34 34 N 10 7264 7246 446 Blue 17
7 PM Wed 31 31 N 10 7246 7228 428 Blue 14
8 PM Wed 28 28 N 10 7228 7210 410 Blue 11
9 PM Wed 27 27 N 10 7222 7204 404 Blue 10
10 PM Wed 26 26 NW 9 7217 7198 398 Blue 9
11 PM Wed 26 26 NW 9 7217 7198 398 Blue 9
12 Midnight Thu 25 25 NW 9 7211 7192 392 Blue 8
1 AM Thu 24 24 NW 10 7205 7187 387 Blue 7
2 AM Thu 23 23 N 10 7199 7180 380 Blue 6
3 AM Thu 22 22 N 10 7193 7169 369 Blue 5
4 AM Thu 21 21 NW 9 7187 7158 358 Blue 4
5 AM Thu 20 20 NW 9 7180 7149 349 Blue 3
6 AM Thu 20 20 N 9 7180 7149 349 Blue 3
7 AM Thu 21 21 N 9 7187 7158 358 Blue 4
8 AM Thu 23 23 N 9 7199 7180 380 Blue 6
9 AM Thu 25 25 N 10 7211 7192 392 Blue 8
10 AM Thu 28 29 N 10 7234 7216 416 Blue 12
11 AM Thu 30 31 N 10 7246 7228 428 Blue 14
12 Noon Thu 33 35 N 10 7270 7252 452 Blue 18
1 PM Thu 35 37 N 10 7282 7264 464 Blue 20
2 PM Thu 36 37 N 10 7282 7264 464 Blue 20
3 PM Thu 36 37 N 10 7282 7264 464 Blue 20
4 PM Thu 35 35 N 10 7270 7252 452 Blue 18
5 PM Thu 34 34 N 10 7264 7246 446 Blue 17
6 PM Thu 32 32 N 10 7252 7234 434 Blue 15
7 PM Thu 29 29 N 9 7234 7216 416 Blue 12
8 PM Thu 27 27 N 9 7222 7204 404 Blue 10
9 PM Thu 26 26 N 9 7217 7198 398 Blue 9
10 PM Thu 26 26 N 9 7217 7198 398 Blue 9
11 PM Thu 26 26 N 9 7217 7198 398 Blue 9
12 Midnight Fri 25 25 N 9 7211 7192 392 Blue 8
1 AM Fri 25 25 N 9 7211 7192 392 Blue 8
2 AM Fri 24 24 N 9 7205 7187 387 Blue 7
3 AM Fri 23 23 N 8 7199 7180 380 Blue 6
4 AM Fri 22 22 N 8 7193 7169 369 Blue 5
5 AM Fri 21 21 N 8 7187 7158 358 Blue 4
6 AM Fri 22 22 N 7 7193 7169 369 Blue 5
7 AM Fri 22 22 N 7 7193 7169 369 Blue 5
8 AM Fri 24 24 N 7 7205 7187 387 Blue 7
9 AM Fri 27 27 N 8 7222 7204 404 Blue 10
10 AM Fri 30 31 N 10 7246 7228 428 Blue 14
11 AM Fri 33 34 N 12 7264 7246 446 Blue 17
12 Noon Fri 36 38 N 12 7288 7270 470 Blue 21
1 PM Fri 38 40 N 12 7300 7282 482 Blue 23
2 PM Fri 40 41 N 12 7306 7288 488 Blue 24
3 PM Fri 40 41 N 12 7306 7288 488 Blue 24
4 PM Fri 40 40 N 10 7300 7282 482 Blue 23
5 PM Fri 38 38 N 10 7288 7270 470 Blue 21
6 PM Fri 35 35 N 9 7270 7252 452 Blue 18
7 PM Fri 32 32 N 9 7252 7234 434 Blue 15
8 PM Fri 30 30 N 8 7240 7222 422 Blue 13
9 PM Fri 29 29 N 8 7234 7216 416 Blue 12
10 PM Fri 29 29 N 8 7234 7216 416 Blue 12
11 PM Fri 29 29 N 8 7234 7216 416 Blue 12
12 Midnight Sat 28 28 N 7 7228 7210 410 Blue 11
1 AM Sat 27 27 N 7 7222 7204 404 Blue 10
2 AM Sat 26 26 N 6 7217 7198 398 Blue 9
3 AM Sat 25 25 N 6 7211 7192 392 Blue 8
4 AM Sat 24 24 N 6 7205 7187 387 Blue 7
5 AM Sat 23 23 NW 6 7199 7180 380 Blue 6
6 AM Sat 23 23 N 6 7199 7180 380 Blue 6
7 AM Sat 24 24 N 6 7205 7187 387 Blue 7
8 AM Sat 26 26 N 6 7217 7198 398 Blue 9
9 AM Sat 29 29 N 7 7234 7216 416 Blue 12
10 AM Sat 33 34 N 8 7264 7246 446 Blue 17
11 AM Sat 36 37 N 9 7282 7264 464 Blue 20
12 Noon Sat 39 41 NE 10 7306 7288 488 Blue 24
1 PM Sat 42 44 NE 12 7330 7306 506 Blue 27
2 PM Sat 43 44 NE 12 7330 7306 506 Blue 27
3 PM Sat 43 44 NE 10 7330 7306 506 Blue 27
4 PM Sat 42 42 N 9 7312 7294 494 Blue 25
5 PM Sat 40 40 N 8 7300 7282 482 Blue 23
6 PM Sat 37 37 N 8 7282 7264 464 Blue 20
7 PM Sat 34 34 N 8 7264 7246 446 Blue 17
8 PM Sat 32 32 N 8 7252 7234 434 Blue 15
9 PM Sat 31 31 N 8 7246 7228 428 Blue 14
10 PM Sat 31 31 N 8 7246 7228 428 Blue 14
11 PM Sat 31 31 N 8 7246 7228 428 Blue 14
12 Midnight Sun 30 30 N 8 7240 7222 422 Blue 13
1 AM Sun 30 30 N 7 7240 7222 422 Blue 13
2 AM Sun 29 29 N 7 7234 7216 416 Blue 12
3 AM Sun 28 28 N 7 7228 7210 410 Blue 11
4 AM Sun 27 27 N 7 7222 7204 404 Blue 10
5 AM Sun 26 26 N 7 7217 7198 398 Blue 9
6 AM Sun 26 26 N 7 7217 7198 398 Blue 9
7 AM Sun 26 26 N 6 7217 7198 398 Blue 9
8 AM Sun 28 28 N 6 7228 7210 410 Blue 11
9 AM Sun 31 31 N 7 7246 7228 428 Blue 14
10 AM Sun 34 35 N 8 7270 7252 452 Blue 18
11 AM Sun 38 39 NE 9 7294 7276 476 Blue 22
12 Noon Sun 41 43 NE 10 7321 7300 500 Blue 26
1 PM Sun 44 46 NE 10 7371 7320 520 Blue 29
2 PM Sun 45 46 NE 10 7371 7320 520 Blue 29
3 PM Sun 45 46 NE 9 7371 7320 520 Blue 29
4 PM Sun 44 44 NE 9 7330 7306 506 Blue 27
5 PM Sun 42 42 N 8 7312 7294 494 Blue 25
6 PM Sun 39 39 N 8 7294 7276 476 Blue 22
7 PM Sun 36 36 N 8 7276 7258 458 Blue 19
8 PM Sun 33 33 NW 8 7258 7240 440 Blue 16
9 PM Sun 32 32 NW 8 7252 7234 434 Blue 15
10 PM Sun 32 32 NW 8 7252 7234 434 Blue 15
11 PM Sun 32 32 NW 8 7252 7234 434 Blue 15
12 Midnight Mon 31 31 NW 7 7246 7228 428 Blue 14
1 AM Mon 30 30 N 6 7240 7222 422 Blue 13
2 AM Mon 29 29 N 5 7234 7216 416 Blue 12
3 AM Mon 28 28 N 5 7228 7210 410 Blue 11
4 AM Mon 27 27 NW 6 7222 7204 404 Blue 10

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 [email protected]