+- Punaweb Forum (http://punaweb.org/forum)
+-- Forum: Punaweb Forums (http://punaweb.org/forum/forumdisplay.php?fid=3)
+--- Forum: Punatalk (http://punaweb.org/forum/forumdisplay.php?fid=10)
+--- Thread: Wind Storm Alert for Hawaii (/showthread.php?tid=17991)
RE: Wind Storm Alert for Hawaii - Durian Fiend - 01-22-2017
Puna's OK with strong trades. Here's a trippy website for showing world wind currents. Zero in on the Pacific with a point and click. http://earth.nullschool.net/about.html
RE: Wind Storm Alert for Hawaii - Ino - 01-22-2017
Why it’s not windy on our mountain’s summits with this event.
The answer is simplified for ease of understanding. A dome of ( relatively ) warm, dry, stable, subsiding air is moving across the North Central Pacific. Do you remember that rare crystal clear day here a few days ago- Last Sat. I think? The center of the dome was directly overhead. Now we’re on the edge of that dome.
When the center of the dome is overhead the inversion is strong and low in altitude -Inversions;
https://en.wikipedia.org/wiki/Inversion_(meteorology)
Determine inversion here;
http://weather.rap.ucar.edu/upper/phto.gif
I think the inversion was around 2-3k when the wx was so clear here. Then a disturbance or cold front comes along and raises the inversion. This creates weak spots on the edge of the dome. And the dome is more uniform when it moves across the flat ocean. This changes dramatically when the dome encounters obstacles like mountains.
On Friday the inversion here rose to 7k and is predicted to rise to 10k or higher- but still below the summits. Inversions mark the weight of the air above. The heavier the air the lower the inversion. Currently the center of this dome is at 33 N Latitude at 1031 mb. The dome is weakening as it fills the Storm Low off the West Coast. The winds at the surface correspondingly are weakening also. When the inversion rises above the summits then clouds and precipitation can develop there.
Currently the summits are in the part of the dome where the air is strongly subsiding but more by weight than by air movement. The surface is where the air masses are mixing and if you can visualize where the air is flowing out from the dome-much like a whoopee cushion. Lots of storm damage across the state especially Northern islands and areas;
http://khon2.com/2017/01/21/downed-trees-blown-roofs-power-outages-strong-wind-gusts-create-mess-across-state/
A cool resource- this illustrates very well where the wind is and if you’re into comparing the different wx models this one’s good for that-click on compare forecasts ;
https://www.windytv.com/19.580/-155.193?19.059,-155.193,8
Tuesday night/Weds. winds will start to ramp up there as the jet stream sags South, bringing strong Northerly flow aloft on the eastern flank of a dome- summit winds will increase;
http://www.stormsurfing.com/cgi/display_alt.cgi?a=npac_250
At that time you’ll have high winds but it’ll be (relatively)calm at the surface-a reverse of current conditions.
RE: Wind Storm Alert for Hawaii - Eric1600 - 01-22-2017
Ino, what are the x and y axis of that chart: http://weather.rap.ucar.edu/upper/phto.gif
windytv is a beautiful animation of the data.
RE: Wind Storm Alert for Hawaii - Ino - 01-22-2017
Eric1600 How long do you have? That could be a very long post-people would run. Hard to simplify this one although with practice it's easy to read.
Obtained twice a day (I think it's 1 pm and 1 am? ) by weather balloon from Hilo International;
https://www.esrl.noaa.gov/gmd/ozwv/wvap/hilo.html
Here's the basics;
http://www.theweatherprediction.com/thermo/skewt/
More detailed here;
http://airsnrt.jpl.nasa.gov/SkewT_info.html
RE: Wind Storm Alert for Hawaii - Frank - 01-22-2017
great stuff ino... a wx link
https://www.ventusky.com/?p=19.7;-155.1;4&l=wind
RE: Wind Storm Alert for Hawaii - HI_Someday - 01-22-2017
I may have gotten this link on Punaweb. Or not. But it's mesmerizing to watch. Similarly graphics to one link posted above. You can view sea temps and other stuff.
https://www.windytv.com/?19.231,-155.082,8
RE: Wind Storm Alert for Hawaii - Eric1600 - 01-22-2017
Thanks ino. Now that I understand it's log pressure vs relative saturation it makes sense. Is the upper left a distance plot of the track?
RE: Wind Storm Alert for Hawaii - TomK - 01-22-2017
Ino - thank you! I'll admit I never actually considered thinking of these systems as a dome, but it has really helped me understand things much better. I always had trouble understanding what "subsiding" meant when I read the MKWC summit forecasts, but it's like a lightbulb just went off.
I hope you continue to educate us, your posts are fascinating.
RE: Wind Storm Alert for Hawaii - kalakoa - 01-23-2017
It's like some kind of "certification" that we did have "high wind conditions"...
http://www.hawaiitribune-herald.com/news/local-news/wind-causes-thousands-lose-power
RE: Wind Storm Alert for Hawaii - Ino - 01-23-2017
Eric1600 I do not understand your question. I’m not an expert with the skew-T. It’s a very small sample ( a balloon thru the atmosphere- lucky there’s one launched in Hilo) and I mostly just use it to determine local inversions. Here are some more resources that might help. If you scroll down here you’ll find a graph and you can look at how the Skew-T Log- P is configured;
http://www.srh.noaa.gov/srh/jetstream/upperair/skewt.html
http://www.atmos.millersville.edu/~lead/SkewT_HowTo.html
TomK If you think of the atmosphere as a fluid, you’ll realize that it’s all a balancing act. Occasionally things get out of whack but it has always amazed me how related the Domes ( Highs ) and rising air features (Low) are. So much so that when we had our big amplified dome it was chasing a huge area of sharply rising air. The strength of the various pressure systems are directly related to what’s near them. As they reach their equilibrium the wx forces relax or if this equilibrium goes the other way the wx forces intensify.
Kalakoa my favorite wx thing to do is to verify what just happened. I try to learn and understand what went down –lots of resources for this. I won’t bury you but submit the following, We had a 84 mph wind recording at Kohala Ranch yesterday ;
http://www.raws.dri.edu/cgi-bin/rawMAIN.pl?hiHKOH
A good recap;
http://www.hawaiinewsnow.com/story/34317123/high-wind-warning-extended-as-powerful-winds-buffet-state
Official storm reports from the NWS;
http://www.prh.noaa.gov/hnl/pages/lsr.php
We did get a frontal passage yesterday. But by that time the gradient had relaxed. But a good example of how our mountains can sometimes protect us by deflecting the winds around them. That said it could have been a different story had the pressure pattern just been a little different.
ElysianWort It’s good to know your exposure very well. As wx system rotate in many times you’ll experience all the wind directions on a compass. Want to win a bar bet? The prevailing wind at Hilo is SW. Most people, even those who should know better think it is NE;
http://www.wrcc.dri.edu/htmlfiles/westwinddir.html#HAWAII