Wind map 3

Here is another wind map website.

Now there are three of these (links in the right column of the blog). Which one is your favorite?

The weather is better in Hobbs

Evan sent this image of yesterday's cloudbase forecast for Hobbs, New Mexico (X marks the spot). Red is good (note the scale at the bottom).

It could be better, I guess. We know what color comes after red.

T8's Wx Links for Mt Washington

I put all of these in a folder on my toolbar called "Mt Wash WX". Then all I need to do to get all the weather I need is click on the folder and select "Open All in Tabs".

There: I just saved you about three minutes a session and at least one case of carpal tunnel syndrome at the margin.

To use these, create a new bookmarks folder, then select the following list of bookmarks (as text) and copy into your new folder.

http://www.drjack.info/BLIP/ETA/NE/FCST/wfpm.curr.18z.png
http://www.drjack.info/BLIP/ETA/NE/FCST/blwindkt_blwinddeg.curr.18z.png
http://www.drjack.info/BLIP/ETA/NE/FCST/hft.curr.18z.png
http://www.drjack.info/BLIP/ETA/NE/FCST/sfcsunwm2.curr.18z.png
http://www.mountwashington.org/weather/cam/ravines/index.php
http://weather.yahoo.com/united-states/new-hampshire/gorham-2412336/
http://aviationweather.gov/adds/satellite/displaySat.php?region=ALB&isingle=multiple&itype=vis
http://aviationweather.gov/adds/progs/
http://aviationweather.gov/adds/winds/
http://www-frd.fsl.noaa.gov/mab/soundings/java/plot_soundings.cgi?airport=bml&start=latest&n_hrs=16&data_source=MAPS

I don't have an opinion on which sounding model is "best", let alone for what reasons. In addition to forecasting possible wave, it's useful to get some idea of temps aloft and forecast possibility of extensive clouds (alt., depth, timing). Maybe someone can chime in here if they have researched this.

Additional useful links solicited.

-T8

No flying today

Click here for the big version.


Credit: NASA.

Monday, Monday

And I'm at work, of course. It's gorgeous outside. That satellite view is the current one, and it's pretty good! Even more interesting is the satellite loop for the last couple of hours. Unfortunately, I can't figure out how to capture this. But it shows, among other things, that the cu that are decorating the PA ridges are moving SW along the ridge tops, clearly marking thermal convergence lift of the type that I've been talking about with some of you these last couple of weekends.

-T8

The Mother of all Omega Blocks

...is right here, right now.

Read all about 'em

These things persist for days and days. Now you know why the Region 2 contest at Mifflin Co PA was rescheduled for next week.

Spring Wave

A friend (Mark Lindberg) was skiing at Attitash last Thursday (3/17) and took these pictures looking toward Mt. Washington (to the left).

Here is the skew-t:

I guess the clouds were around 12,000'. Surprisingly light wind (multiply w/s in m/s times 2 to get kts). About 26 kts at 6,000', 40 kts at 12,000', 46 kts at 18,000'. The observatory on the summit of Mt. Washington was reporting 40 kts.

Tim

25 below

Here's a satellite photo from January 24, 2011 - which, if we're lucky, will turn out to be the coldest day of the year.

Click here for the big version and see if you can spot Gordon tossing the cup of hot water into the air.


The cloudstreets over the Atlantic are really cool, too.

Credit: NASA

This can't be good

Wave Season Has Started

Actually it started a couple of weeks ago. I have been watching the weather using Kevin’s article as a guideline. It seems to work pretty well. When the skew-T predicts wave there is usually signs of it in the clouds. Up until this weekend I wasn’t able to fly on promising wave days. On Saturday the skew-T looked good. Here is the skew-T for Saturday (historical info is available at this NASA site).

There were cloud streets and wave like clouds at 5-6K just like you would expect from the skew-T. Andy took the towplane up for a warm up and reported moderate turbulence (rotor). Bill (3J) and Tom (TH) went up first to scout things out and found usable lift to 5.5K under the clouds. Since they were sticking I took the next tow.

Off tow I was able to fly around at 5.5-6K with Tom and Bill in rough thermal/rotor lift. If I got to cloud base I would try to slide out into the clear air next to the clouds but could not contact any wave lift (in hindsight I was probably looking on the wrong side of the clouds).

After flying around Post Mills for about an hour and unsuccessfully trying to find wave lift I headed out on a cloud street going southwest. The street was working great and for the most part I could fly without circling. But if there was a clearing in the clouds I would circle up and look for wave lift. Nothing really felt like wave. The clouds seem to be honest. The darkest clouds had strong lift.

As you approach Killington Peak the terrain goes up and the fields disappear. The clouds still looked good and there was this clearing ahead so I felt pretty confident as I headed toward the peak.

This clearing turns out to be (I looked it up the next day) Plymouth VT and the Calvin Coolidge Homestead. As I approach the Green Mountains the clouds don’t seem to be working anymore. I can’t find any lift. I feel like I am kind of stuck because this is the only clearing for 5-10 miles so I don’t dare leave to go back to lower ground. As I sink lower I move closer to the clearing. Finally I fly over a steep ridge ½ mile west of the clearing and find some lift. It is strong lift but it is turbulent. I am now down to 3200’ msl which is only 1000’ over the ridge and 1500’ over the clearing. I try circling but get blown to the west and out of the lift. After struggling for what seems like a long time I figure out that if I “ridge soar” the little ridge by doing figure eight’s I can get a pretty steady climb. I stay in that same spot and finally get some altitude. As I get up to about 4,200’ I notice I am in the sunlight and there is a pretty well defined wave window right above me. The lift is consistent and getting stronger. I stay in that same spot and climb up through the window and after an hour I top at 14K (I am glad I put the oxygen tank in last week). The wave window is small and there is solid overcast west to NY, but there are larger windows to the east and I know I can get to them if my window closes.

The glide computer says I will arrive back at Post Mills at 9,600’ agl so I head for home. I can hop over the bands of clouds to stay over the wave windows but I don’t seem to be picking up much lift. I arrive at Post Mills still at 11K so I guess there must have been some. Its time to burn up some altitude and get below the clouds so I push up the speed and head towards Black Mountain. Going downwind the data logger trace shows a ground speed of 338 km/hr (210 mph!).

Sonny, Andy, Alexander and Kevin help me put the glider away when I land. Thanks!

The flight log is available here (thanks Rick):

And thank you Cal Coolidge for clearing that spot.

Tim

P.S. All day I couldn’t figure out exactly which way the wind was blowing. I should have realized that wave clouds and wave windows line up parallel to the mountain that produce them and not necessarily perpendicular to the wind. If the wind hits the mountain at a 30-degree angle the clouds will be at a 30-degree angle to the wind.

Avoiding depression

One way to avoid a tropical depression is to go flying before it arrives.


On Thursday, Tim (PM) and Tom (TH) took one look at the forecast and decided to go flying before it was too late. It was a very hot day (95°F) with weak lift to 4300 feet.

Thermal centering was complicated by wind shear, but Tim was able to figure it out:

After they landed, we tied down all the trailers. Here's the forecast for the start of the weekend:

Now that's depressing.

Dr. Jack

This may be old news but I didn't know... Dr. Jack's BLIP soaring forecasts are now free (the whole site). All you have to do is register. After you register look at the NAM blipmaps for the northeast (I find these the most useful). To get started look at the maps for thermal updraft velocity (how fast the thermals are going up), buoyancy/shear ratio (if the wind will break up the thermals, above 5 is good), critical height (how high a glider will top out) and Cu Cloudbase (where the bottom of the clouds are). Then don't trust anything you've seen.

http://www.drjack.info/

Tim

BLIPspot renewed

The BLIPspot forecasts for Montpelier, VT have been renewed for 2010 (by me - anybody want to help me pay for it?). They can be accessed via this link, which has been added to the list of Weather Links on the right.

If you are not familiar with the BLIPspot, see my long note from last year

- Moshe

Wave at Post Mills

The best wave day of the year may have been last Sunday. Too bad the gliders were put away. Paul and I flew in my Champ and Andy in his. Paul and I went to 11,000’ between PM and Montpelier. At times the rate-of-climb indicator showed over 1600 fpm (with the engine throttled back to produce zero sink). We probably could have gone higher, we weren't even trying. Wave windows and some lenticulars marked the wave over many oscillations. The winds were not that strong so it probably would have been easy to transition to the next crest upwind in a high performance glider. The picture (Paul’s) above shows a wave window and the backside of a lenticular. You can see the rest of Paul’s pictures at:

http://picasaweb.google.com/postmillsrc/2009126Paul

Here is the Skew-T for the day (sorry about the units). Wind was due west at 28 kts (14 m/s) at 9,500’ (2908 m).



Tim

Wave Camp Wx Links

Here are some useful weather links for Gorham. Please add your favorites:

Surface progs

More surface maps

BML Sounding

Richard Kellerman's tutorial on Skew Ts -- chiefly geared towards thermal soaring (anyone have a more wave oriented ref?)

View from Wildcat into the Ravines


View of Mt Wash from near Conway


Northeast US radar

Satellite view

Another satellite view

When weather looks better for web surfing than sky surfing, might as well check out the extra-terrestrial kind of weather, too.

Blip

For several years now "Dr. Jack" Glendening, a West-coast meteorologist, has arranged an on-line soaring-specific forecast based on National Weather Service data. Although that data is available elsewhere, putting it all together into a forecast of the day's thermal height and strength (and cloudiness) is a chore better left to a computer program. His setup also generates color-coded maps that neatly show the wider geographical patterns. But for local, or even short-range cross-country flying, you can't beat his one-page textual summary for a specific location, known as "BLIPspot". The closest BLIPspots to us were in Mass. and Ontario, and for years I've wanted one in our area.

So now I've gone ahead and asked Dr. Jack to make one for us, located at the Montpelier airport. Why there? It is not a soaring base per se, but the 3 soaring operations in Northern Vermont are within 20 miles around it. It does not boast elevation as high as nearby hills, but is 500 feet higher than the valleys, and represents the relatively lower ground between the mountains where some thermals are needed in order to soar cross-country in our area. We can then expect lift to be better in the mountains. If we were to base a BLIPspot on Spruce Mountain instead, for example, the forecast may be good for the mountains, but would be overly optimistic for most of the XC area. Also, this airport is a TAF, METAR and ASOS spot, and thus one can compare the actual temperature and dewpoint, reported hourly, with the forecast and adjust one's expectations accordingly.

BLIPspots are freely accessible to anybody, although you need to "register" with Dr. Jack's site. But the sponsor of a BLIPspot needs to pay an annual fee to create and maintain it. If you find the BLIPspot useful, consider helping me with the payment, this year or in the future.

The new BLIPspot can be accessed either via the main BLIPSPOT page, or directly at this link.

The location of the new BLIPSPOT is shown on the regional "grid orientation" map - it can be accessed via an "Identified Locations" map for the NE region.

Important message from Dr. Jack:

PLEASE PASS ALONG THE FOLLOWING INFORMATION TO ANY WHO WILL WANT TO ACCESS THIS BLIPSPOT:

This BLIPSPOT is available for viewing by anyone via the internet, but access to the "current day" forecasts (which everyone will want) does require that each user individually "register" (which is free) at this link. I require individual registration, rather than group registration, because knowing the number of individual users of each forecast product is important to me.

Registration also allows access to the other "free" DrJack forecasts, which includes "Thermal Updraft Velocity" BLIPMAPs, "Buoyancy/Shear Ratio" BLIPMAPs, all "Previous Day" BLIPMAPs, and all BLIPSPOTs. "Subscription" (which is not free) is required to gain access to the other DrJack BLIPMAP forecasts. Normally registered/subscribed access occurs through use of a DrJack registration "cookie", for which one's browser must accept cookies from the "drjack.info" domain. (In lieu of accepting cookies, more complex "cookieless" access methods are available.) For further information on DrJack registration, see this link.

Notes from Moshe:

* I use cookieless access by embedding my registered ID in the URL thusly:

http://www.drjack.info/BLIP/RUC/SPOT/FCST/montpelier_vt.txt?id=user&pw=password

* For BLIPMAPs go here.

* More details on the BLIPMAP and BLIPSPOT parameters can be found here - I've written up some interpretive text (shorter than the page linked above, longer than the brief definitions in the bottom of the BLIPspot page itself):

The BLIPspot includes forecasts for several times of day, the important ones for us would be: 15Z (11 am EDT), 18Z (2 pm), and 21Z (5 pm) - spanning the possible soaring hours. Note that the time dimension is only available in BLIPSPOTs, not in the BLIPMAPs.

Temp@2m is the forecast ground temperature (actually 2 meters above ground), on which the predicted thermals are based, and can be compared with actual temperature (as measured or reported in METARs, e.g. at 11am) to judge whether the BLIPspot forecast is working out.

BL throughout stands for "boundary layer", the part of the lower atmosphere mixed by the thermals.

BL Depth shows how high the thermals will reach AGL.

BL Top shows the altitude MSL at the top of the thermals.

Hcrit: the very tops of the thermals are too weak to use, "Hcrit" shows the expected top of the usable part of the thermals [ftMSL] (assuming blue thermals, otherwise cloudbase caps the usable top).

Hgt.Variab. shows the uncertainty or variability of the BL depth, it will be this much higher over hot spots (4 degrees hotter - or effectively so, via higher ground elevation). This variability is influenced by the temperature profile of the atmosphere: if there is a sharp inversion capping the thermals, for example, then this variability will be small. On the other hand, if the lapse rate is still high at the tops, the thermals will be significantly higher over hot spots (or lower, if the ground temperature turns out lower than forecast).

W* is the Thermal Updraft Velocity (in fpm - subtract glider sink rate (typically about 150 fpm) to get climb rate).

B/S = Buoyancy/Shear Ratio. This compares the upward buoyancy of the thermals to the horizontal shear due to the change in wind speed or direction with altitude. Thermals may be unworkable if B/S is 5 or less.

BL Wind = Wind Speed averaged through BL [kt] - keep in mind that wind speed may change quite a bit with altitude - look at the wind profile at the bottom of the BLIPSPOT.

Direction = Wind Direction averaged through BL [degTrue] - keep in mind that wind direction may change quite a bit with altitude - look at the wind profile at the bottom of the BLIPSPOT.

CLOUDpotent predicts the potential for the thermals to condense into cumulus clouds. Expect clouds if this is positive. If this is large then the clouds will be thick. (This number is the height difference between the top of the thermals (if they were blue) and the expected cloudbase (due to moisture).

sfcLCL = Base of Lowest Clouds, if CLOUDpotent>0 (LCL = Lifting Condensation Level based upon sfc. humidity) [ftMSL]. If that's higher than Hcrit then the prediction is that cloudbase will be unreachable.

ODpotential is the potential for "overdevelopment" - expect extensive clouds if positive. (This number is the difference between H(TI=0) & blCL) [ft].

bLCL = Base of Extensive Clouds, if ODpotential>0 (bl CL = Condensation Level based upon BL humidity) [ftMSL] - the difference between this and sfcLCL is that this is based on the moisture of the humidity of the whole BL, while sfcLCL is based on the humidity near the surface - if the air aloft is fairly dry, then there will not be "overdevelopment" and the condensation of the moisture brought up from near the surface will result in only limited cu.

CAPE = Convective Available Potential Energy [J/kg] - if this is high then the condensation in clouds will release a lot of additional "latent" heat and the cu will get thick and there may be thunderstorms.

DewPt@2m = Dew Point Temp. at 2m AGL [F] - this is the basis for the forecast of cloudbase (sfcLCL), and can be compared with actual dewpoint (as reported in METARs) to judge whether the BLIPspot forecast is working out.

As you can see, there is a lot of good info at-a-glance in the BLIPspot: not just how strong the thermals will be, but also their workable height, change during the day, and the potential for overdevelopment.

Additionally, the BLIPspot lists the predicted wind profile (speed and direction) at different altitudes at several times. The asterisks in this table bracket the BL top altitude.

One thing the BLIPspot does NOT offer is a sense of how things will be different in different places. If planning a long XC, one should also look at the BLIPmaps, which roughly describe many of the same parameters via color coding on a map. BLIPmaps for thermal strength and B/S ratio are available free (as are BLIPspots, once sponsored), while the other BLIPmaps are available by paid subscription.

- Moshe