Results 1 to 8 of 8

Thread: Fly Thursday 7 April

  1. #1
    Join Date
    Jan 2011
    Location
    Schleicher ASW-24
    Posts
    2,107

    Fly Thursday 7 April

    I have tentatively booked the WSC ASW24-88 to fly on this Thursday based on the TV forecast. The TV says it is going to be about 90 degrees on Wednesday.
    In April? 90 degrees? Really?

    Also, the TV says the Temp on Thursday will be less than Wednesday.
    RASP shows strong surface winds Tue and Wed in the WSC area.
    RASP and BLIP don't extend to Thursday - yet.

    More than a 48 hour Fcst in this situation by me is unreliable, and I readily admit that it may be more hopefulness than science at this point.
    I will look at it again tomorrow morning - when the RASP is published for the 48+ hours fcst for Thursday.

    FYI, OJ is still not booked.
    Peter Kelly

  2. #2
    Join Date
    Jan 2011
    Location
    Menlo Park, CA
    Posts
    939

    Re: Fly Thursday 7 April

    My $0.02 is that high pressures on top of us, unless accompanied with moister air, seem to rarely benefit us in the thermal dept at WSC. The few times I've thought it might work it out, there were very few strong thermals but widely separated. A low level high, OTOH, is great and can produce spectacular days.

    As of this morning, the Wed RASP is looking pretty dry with a lid on the Mendos at 7K.
    Kemp
    ASH-25 (FNX)

  3. #3
    Join Date
    Jan 2011
    Location
    Schleicher ASW-24
    Posts
    2,107

    Re: Fly Thursday 7 April

    Quote Originally Posted by Kempton View Post
    My $0.02 is that high pressures on top of us, unless accompanied with moister air, seem to rarely benefit us in the thermal dept at WSC. The few times I've thought it might work it out, there were very few strong thermals but widely separated. A low level high, OTOH, is great and can produce spectacular days.

    Update - Monday night.

    As of this morning, the Wed RASP is looking pretty dry with a lid on the Mendos at 7K.
    Good info Kempton and thank you for adding. I agree, but of course, that was mostly Wednesday that you were talking about.

    As I was hoping would happen, the pressure patterns are changing. Thursday is looking better for sure.
    Hope is better than science, at least for me.
    Peter Kelly

  4. #4
    Join Date
    Jan 2011
    Location
    san jose, ca
    Posts
    137

    Re: Fly Thursday 7 April

    I will be monitoring the rasp and if conditions look fairly good i will fly up on thursday.

    Key

  5. #5
    Join Date
    Jan 2011
    Location
    Schleicher ASW-24
    Posts
    2,107

    Re: Fly Thursday 7 April

    Quote Originally Posted by key dismukes View Post
    I will be monitoring the rasp and if conditions look fairly good i will fly up on thursday.

    Key
    Good plan... To recheck RASP before you make the trip.
    What Kempton stated certainly has been my experience also. Thermals don't usually go very high with the high pressure over the top of us.

    The reason the RASP +2 (the Thursday fcst) looked promising last night is that the hot Valley air was coming up the Mendos from the east. The wind cross section/ parallel section portrays the expected thermals on the Mendos pretty well. Trouble is, they will be spaced several miles apart from each other. And, they may not be any further south than Snow Mtn.

    Name:  boxwmax.curr+2.1300lst.d2.png
Views: 169
Size:  17.6 KB
    If we get any pressure changes in the model, and we get a stronger flow, we may not get thermals very high. The soundings at goat and black butte both indicated a strong inversion.
    But I hope it's good, and I hope you fly up.
    Last edited by Peter Kelly; 04-06-2016 at 10:07 AM.
    Peter Kelly

  6. #6
    Join Date
    Jan 2011
    Posts
    168

    Re: Fly Thursday 7 April

    Quote Originally Posted by Peter Kelly
    ... Thursday is looking better for sure.
    Hope is better than science, at least for me.
    I agree completely. Hope is better than science - and it is easier to grasp. The Weather Underground forecast shows decreasing pressure on Thursday for the valley, so I hope that means the lid may be coming off the inversion. I too will monitor the RASP and, if the forecast allows, try to escape the plethora of mundane tasks that have put a high pressure lid on my personal ability to get out and enjoy soaring with friends.
    Jim D. - 1B

  7. #7
    Join Date
    Jan 2011
    Location
    Schleicher ASW-24
    Posts
    2,107

    Re: Fly Thursday 7 April

    Update Wednesday, predawn.
    I won't try to portray the upper atmosphere. Not the usual , that's for sure. Read the discussion by the San Fran nws office if you're interested.
    It's wait and see for flying on Thursday. It could go either way.
    Besides chances of winds and unsettled Wx coming up from the south!, we can also monitor the high cirrus that will likely be moving over, eventually by Friday.

    The sacramento nws also has a good descriptive discussion.
    Peter Kelly

  8. #8
    Join Date
    Jan 2011
    Location
    Schleicher ASW-24
    Posts
    2,107

    Re: Fly Thursday 7 April

    Update - 9 AM Wednesday.
    RASP and BLIP combined tell the story.
    And, although it would be interesting to go the gliderport and fly during the transition periods of no wind/ wind and clouds/ no clouds, and lift/ no lift over the 20 gap area, I think I will cancel my reservation to fly and wait for a more settled day.

    Doug Armstrong always talked about diurnal temp changes approaching 40 degrees as being an especially good indicator of good soaring conditions in the high desert. Of course, that doesn't apply here: 1. this isn't high desert, and 2. he didn't say that rule applied in these types of situations.

    Looking at the Live Oak Station (as shown on WSC Weather page (top left)) the low temp this morning was 50 deg at 7 AM, High today is fcst to be 89, and even over 90 in some spots, giving us 40 deg spread, but the baro pressure peaked at 8 AM today at 30.19 and is expected to drop to 29.81 by 6 PM tomorrow (nearly a 400 foot drop in altimeter readings).

    RASP for today shows nearly zero for BS and minimal strength on the thermals - air mass at WSC for today is quite (make that - extremely) stable.
    Last edited by Peter Kelly; 04-06-2016 at 10:10 AM.
    Peter Kelly

Similar Threads

  1. Fly - Thursday 5/26
    By Peter Kelly in forum News & Discussion
    Replies: 10
    Last Post: 05-28-2016, 03:19 PM
  2. Fly - Thursday 3/24/2016
    By Peter Kelly in forum News & Discussion
    Replies: 12
    Last Post: 03-27-2016, 07:08 PM
  3. Fly - Thursday 2-25-16
    By Peter Kelly in forum News & Discussion
    Replies: 19
    Last Post: 02-29-2016, 09:15 AM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •