soaring_hawk_sketch

BLIPMAP FORECASTS
BLIPMAPs give thermal soaring parameters over a geographic region.
BLIPMAP = Map of Boundary Layer Information Predictions
[The Boundary Layer (BL) is the region mixed by thermal eddies]
Created by Dr. John W. (Jack) Glendening, Meteorologist 


21Z  Montague  Forecasts
DEVELOPMENTAL 20km FSL RUC RESULTS    
Info on First Available Times   Forecasts are updated during the night

Current time & day:       (time="---" if none available for current day)

DrJack sez:
May 9:  I just found that the registration software does not detect whether your browser has cookies enabled and will blithely tell you a cookie has been "successfully sent" even when it was not successfully received!  The person who wrote that software has been informed and is working on a fix, but in the meantime if your browser might have that problem you can test it by clicking on the Cookie Tester to get a message "Cookies are enabled" or "Cookies are disabled" (if you get neither, then you must not have Javascript enabled!)
May 9:  I have implemented "cookieless" access for registered users, though it does not have the full flexibility of cookie-enabled access. 
May 8:  Updated the Contributors webpage.
May 7:  I added more information on how to deal with possible problems to the Registration Information webpage, although I have had remarkably few messages describing difficulties and so far 650 registered users have been able to successfully view forecasts.
May 6:  I implemented a module to let registered viewers who have forgotten their password or userID send that information to the email address supplied when registering. 
May 4:  For those who tried to access or "Login" this AM and received an error, that problem has now been corrected.  The long story is provided here.
May 2:  Updated the "Frequently Asked Questions" page (with answers).
May 1:  As of today I have implemented a system which registers users of DrJack forecasts.  The locations of the individual forecasts have therefore changed!  The primary reason for this change is to better assess present forecast use, particularly how many forecast users there are and the ratio of Sailplane to HangGlider to Paraglider use.  Registration is not required but is strongly encouraged because it will help me better determine the future course of forecast development (if you do not register your forecast viewings will not be counted as a use by your pilot group).  Those those who have bookmarked individual forecasts will need to create new bookmarks; also, the javascript viewer no longer works without registration.  In addition, if you have created a website with "hot links" to the individual maps you will need to contract me.  Further information is provided when you click on a forecast link, if you are not yet registered, and at the Registration Information webpage
April 29:  Updated BLIPMAP "to-do" projects list.
Apr 21:  THIS IS THE NEW WEBSITE !  If you are reading this then you are at the new website!  I have constructed it to (hopefully) be identical to the previous one, but if you find something that does not seem to work properly please let me know as there are likely undiscovered bugs/deficiencies.
Apr 2:  I got some feedback on the April 1 BLIPMAPs!
Apr 2:  Updated the monthly BLIPMAP usage statistics.
Mar 30  The clouds are fixed!   I finally got things sorted out and am now running a corrected program with BLIPMAP cloud predictions turned back on.  Bob Gibbons of Texas deserves thanks for having both the initiative to critically evaluate the "Cumulus Cloudbase" prediction and the knowledge to compare it to a simple surface-humidity LCL condensation formula.  As a check, the "EXPERIMENTAL" parameter in the BLIPs will give the approximate formula prediction, which should be within 5% of the printed "Surface LCL" - after the validity of the latter has been demonstrated I will remove the EXPERIMENTAL parameter print.  Those interested in additional details can read the "Sfc-humidity LCL: short and long stories" posting on the DrJack Forum.
Mar 24:  Contributors:  I have added an option to send you, if interested, a daily email when the first BLIPMAP is produced for your region (this is primarily useful on those days when the "first of the day" BLIPMAP is delayed and you may want to "filter" it to a mailbox separate from your main mailbox).  If you wish to be added to that list please let me know.
Mar 22:  BLIPMAP "help" page created:  A "first source for new BLIPMAP users" and summary of additional information is available at the BLIPMAP Help webpage.
Mar 21:  Updated the Info on First Available Times.
Mar 21:  Parameter descriptions changed  I have rewritten the parameter descriptions on this page and created a new linked page with "parameter details", with some diagrams, at the "MoreInfo" link of each parameter.  Having a "parameter details" page provide a good basis for further growth since info can be added to it which would be too cumbersome to add to the basic parameter description.  If you think anything can be improved upon or added to or leaves a question unanswered, please let me know and I will make changes.
Mar 21:  A Google Search specific to the drjack website has now been added (see bottom of this page)
Mar 15:  HAPPY BIRTHDAY TO BLIPMAP !!!    March 16 is the first anniversary of the day on which the first nationwide BLIPMAP forecasts became available.  When did you first hear about them??
Mar 13:  More timely forecasts!  Additional forecasts have just been implemented, so the BLIPMAPs you get will now have the the most timely information possible.  Last summer, when the processing was being done on my old, slow machine, I was forced to provide only half the possible forecasts, i.e. even though FSL provides updated forecasts every 3 hours I was skipping every other one.  Some users have noted that the forecasts sometimes change rapidly in the AM when conditions are uncertain.  Also, some have to leave their houses (and their internet connection) hours in advance to drive to the gliderport.  These additional forecasts will help such users, and all users, to have more timely forecasts than were previously possible.  I should note that this is being done only after coordinating with Bill Hall, and he has agreed to this change which requires more processing on his machine.  There is always the chance that this will later prove to be more of a burden than anticipated and have to be reversed - Bill is doing everyone a great service so this processing should not become bothersome to him.
Mar 7:  CA-NV Users:  Daily "WINDIP" forecasts of upper-air winds and a simple mt. wave forecast are once again available at the WINDIP webpage.
Feb 28:  Updated pilot flight experiences using BLIPMAPs.
Feb 28:  Added a "Rainfall and Soil Moisture" note to the model prediction notes.
Feb 13:  I have created climatology plots from the 2002 forecasts, giving the monthly average of each parameter for each time of day (when available).  In addition, I have computed statistics giving the average, standard deviation, minimum, and maximum for all parameters for all regions.  These plots and statistics can be accessed via the BLIPmap 2002 Climatology webpage
Feb 5:  In response to the many requests received on the first BLIPMAP User Survey, I have created a discussion group for thermal soaring forecasts and meteorology and I am asking that BLIPMAP users generally use that forum if they have a question or comment, since it likely is also of interest to someone else in the soaring community, rather than simply sending an email to me directly - although the latter is of course appropriate if there is some comment you wish to keep private.
Feb 3:  Updated the webpage giving information on creating new BLIP prediction locations nation-wide Note that there must be a contribution to the BLIPMAP effort, of either money or time, to create a new BLIP for your location.
Jan 28:  Activated two new parameters intended to help forecast the presence and cloudbase of small puffy cumulus clouds that form in the BL.  As indicated in their description, there is a theoretical difficulty with these parameters but I have had several reports that for some sites the method is nevertheless effective so decided to include them and let users evaluate how well these parameters work for their site.
Jan 27:  I'm glad I was able to meet many BLIPMAP users while at the SSA Convention in Dayton and at the Wright Aviation Museum and appreciate being presented with an SSA Exceptional Achievement Award there.  I have placed on-line the slides presented in my talk at the 2003 SSA Convention.
Jan 17:  Summarized results from the first BLIPMAP User Survey are now available
Jan 1, 2003:  Congratulations to the first three awardees of the newly created "Order of the BLIPMAP Hero":  Milt Hare (who flies his ASH-25 out of Williams, CA),  Bill Hall (who flies with the Greater Boston Soaring Council), and  John Whitney (who flies his ASW-20 at Blairstown, N.J.).  As a testimonial to the time and effort they have voluntarily put into helping make BLIPMAP a product useful to pilots across the country, they have been presented with a "BLIPMAP HERO"[tm] award suitable for displaying on any T-shirt, sweat-shirt, or undergarment of their choice!  These awards are not available for purchase in any store.  Let's have a hearty round of applause for our "heroes"! 
Dec 29:  In response to user requests, to aid orientation with respect to the smoothed model topography I have modified my plotting program so placename IDs can be plotted on a BLIPMAP region.  The first such plot has been created for AZ (SouthWest region) based on data provided by Gary Evans, so to see what one looks like you can view it here. There are currently (sparse) ID plots available for the CA-NV, NorthEast, SouthEast, OK-TX, NorthCentral, SouthCentral, and SouthWest regions:  to view your region's ID plot or if you are interested in adding IDs for your region, see the regional orientation webpage.
Sept 23:  Who Uses BLIPMAPs?  Of the 1,021 people who responded to a 3 week poll, 80% were Sailplane PIlots, 15% were HangGlider Pilots, 4% were ParaGlider Pilots, 0.6% were Weather Enthusiasts, 0.5% were Weather Workers, and 0.4% were None of the Above.  Based on SSA and USHGA membership numbers, equally random voting from SailPlane/HangGlider/ParaGlider pilots would have given respective percentages of roughly 50/25/25 - the difference between those percentages and the actual results suggests to me that those who fly longer distances are more likely to use BLIPMAPs.
Sept 2:  Remarkable convergence prediction!  Labor Day (today) was a remarkable day in the Sierras with many long flights.  I was particularly interested in reports of a very long convergence line which moved eastward with time, since the BLIPMAPs predicted the occurrence of just such a convergence!  Moreover, subsequence comparison to satellite photos confirms not only that BLIPMAP prediction but also it's prediction of a second (unflown) convergence line!  I have created viewers to look at the hourly development and movement of both the convergence line forecasts and the satellite photos, with viewing instructions and a brief description, here
Aug 18:  THE FUTURE ??  I have begun experimenting with BLIPMAPs using the NWS 12km ETA model instead of the FSL 20km RUC model.  Advantages of the ETA are its higher resolution, 12km instead of 20km, and it provides extended forecasts out to 84 hours.  Some results, for the "Current+2" and "Current+3" days only, can be viewed here  [Note: the ETA regional areas differ from those of the RUC FSL model due to differing map projections used - if you find a different region is needed, go to the regional ETA webpage].  The program is still under development and these forecasts are not being updated daily, but these plots do illustrate what can be done.  At present, the accuracy of ETA vis-a-vis RUC is not known and the accuracy of the longer-range forecasts is especially unknown.  Whether such products might become regular predictions is uncertain, as each forecast requires downloading a half-gigabyte file and there is a cost associated with that. 
July 25:  Added a link to an on-line version of the July 2002 SOARING magazine BLIPMAP article, which is a good "first thing to read" for potential BLIPMAP users.
Sep 17:  For the CA-NV region, multiple times can be viewed without javascript by using the Multitime CA-NV BLIPMAP Index.
Processing remains stable.  Forecast availability varies from day to day.
I only look at the webpages and maps that I use personally or that I suspect might contain an error.  If you notice a consistent problem with either, please let me know.
If there is not yet a BLIPMAP produced for today and you want to see what BLIPMAPs look like, try clicking on the "PreviousDay" links below or see this sample BLIPMAP

For BLIPMAP forecasts at times other than 21Z and/or overlaying multiple parameters, use the javascript viewer found at http://www.drjack.info/BLIPMAP/SPECIAL/viewer.html


Thermal Prediction Parameters:

Thermal Updraft Velocity (W*)      Latest      FirstToday      PreviousDay
Average dry thermal updraft strength near mid-BL height.  Subtract glider descent rate to get average vario reading for cloudless thermals.  Thermal strengths will be stronger if convective clouds are present.  W* depends upon both the BL depth and the surface heating.  MoreInfo
Height of Boundary Layer Top (TI=0 height)      Latest      FirstToday      PreviousDay
Height of the average dry thermal tops, or Thermal Index TI=0 height.  Over flat terrain maximum thermalling heights will be lower due to the glider descent rate and other factors.  However, thermal tops will be higher over small-scale topography not resolved by the model and some pilots have reported that in elevated terrain the heights they can reach over local terrain features correspond better with the TI=0 height than with Hcrit.  In the presence of clouds the thermal top will increase, but the maximum thermalling height will then be limited by the cloud base (see the "Cloud prediction parameters" section below).  [This parameter is truncated at 22,000 for plotting.]  MoreInfo
Height of Critical Updraft Strength (Hcrit)      Latest      FirstToday      PreviousDay
This parameter estimates the height at which the average dry updraft strength drops below 225 fpm and over flat terrain is expected to give better quantitative numbers for the maximum cloudless thermalling height than is the traditional TI=0 height given above, although the qualitative patterns should be similar for both parameters.  (Note: the present assumptions tend to underpredict the max. thermalling height.) In the presence of clouds the maximum thermalling height may instead be limited by the cloud base (see the "Cloud prediction parameters" section below).  [This parameter is truncated at 22,000 for plotting.]  MoreInfo
Thermal Height Variability      Latest      FirstToday      PreviousDay
This parameter estimates the variability (uncertainty) of the BL top (TI=0) height prediction which can result from meteorological variations.  Larger values indicate greater variability and thus better thermalling over local "hot spots" or small-scale topography not resolved by the model.  But larger values also indicate greater sensitivity to error in the predicted surface temperature, so actual conditions have a greater likelihood of differing from those predicted.  MoreInfo
Buoyancy/Shear Ratio (B/S)      Latest      FirstToday      PreviousDay
Dry thermals may be broken up by wind shear and unworkable if B/S ratio is 5 or less.  If convective clouds are present, the actual B/S ratio will be larger than calculated here.  [This parameter is truncated at 20 for plotting.]  MoreInfo

Wind Prediction Parameters:

Wind Speed in the Boundary Layer      Latest      FirstToday      PreviousDay
The speed of the vector-averaged wind in the BL.  This prediction can be misleading if there is a large change in wind direction through the BL (for a complex wind profile, any single number is not an adequate descriptor!).  MoreInfo
Wind Direction in the Boundary Layer      Latest      FirstToday      PreviousDay
The direction of the vector-averaged wind in the BL.  This prediction can be misleading if there is a large change in wind direction through the BL (for a complex wind profile, any single number is not an adequate descriptor!).  Note that there will be a abrupt artificial gradient at the "cross-over" between 0 and 360 degrees.  MoreInfo
BL Max. Upward Motion (BL Convergence)      Latest      FirstToday      PreviousDay
Maximum grid-area-averaged upward motion within the BL as created by horizontal wind convergence.  Positive convergence is associated with local small-scale convergence lines (often called "shear lines" by pilots) - however, the actual size of such features is much smaller than can be resolved by the model so only stronger ones will be forecast and their predictions are subject to much error.  If CAPE is also large, thunderstorms can be triggered.  Negative convergence (divergence) produces subsiding vertical motion, creating low-level inversions which limit thermalling heights.  This parameter can be noisy, so users should be wary.  MoreInfo

Cloud Prediction Parameters:

Cumulus Potential      Latest      FirstToday      PreviousDay
This evaluates the potential for small, non-extensive "puffy cloud" formation in the BL, being the height difference between the surface-based LCL (see below) and the BL top.  Small cumulus clouds are (simply) predicted when the parameter positive, but it is quite possible that the threshold value is actually greater than zero for your location so empirical evaluation is advised.  I would be interested in receiving end-of-season reports on what threshold value worked for your site.  Clouds can also occur with negative values if the air is lifted up the indicated vertical distance by flow up a small-scale ridge not resolved by the model's smoothed topography.  [This parameter is truncated at -10,000 for plotting.]  MoreInfo
Cumulus Cloudbase (Sfc. LCL)      Latest      FirstToday      PreviousDay
This height estimates the cloudbase for small, non-extensive "puffy" clouds in the BL, if such exist i.e. if the Cumulus Potential parameter (above) is positive or greater than the threshold Cumulus Potential empirically determined for your site.  The surface LCL (Lifting Condensation Level) is the level to which humid air must ascend before it cools enough to reach a dew point temperature based on the surface mixing ratio and is therefore relevant only to small clouds - unlike the below BL-based CL which uses a BL-averaged humidity.  However, this parameter has a theoretical difficulty (see "MoreInfo" link below) and quite possibly that the actual cloudbase will be higher than given here - so perhaps this should be considered a minimum possible cloudbase.  I would be interested in receiving end-of-season reports on how well this parameter worked for your site.  [This parameter is truncated at 22,000 for plotting.]  MoreInfo
BL Relative Humidity Maximum      Latest      FirstToday      PreviousDay
This parameter provides an additional means of evaluating the formation of clouds within the BL and might be used either in conjunction with or instead of the other cloud prediction parameters.  Larger values indicate greater cloud probability, but use of this parameter must be empirical since no theoretical guidance is available - for example, pilots must determine by actual experience the percentage that correlates with formation of clouds above local mountains.  The cloud base height is not predicted, but is expected to be below the TI=0 height.  MoreInfo
OverDevelopment Potential      Latest      FirstToday      PreviousDay
This evaluates the potential for extensive cloud formation (OverDevelopment) at the BL top, being the height difference between the BL CL (see below) and the BL top.  Extensive clouds and likely overdevelopment are predicted when the parameter is positive, with overdevelopment being increasingly more likely with higher positive values.  Overdevelopment can also occur with negative values if the air is lifted up the indicated vertical distance by flow up a small-scale ridge not resolved by the model's smoothed topography.  [This parameter is truncated at -10,000 for plotting.]  MoreInfo
OverDevelopment Height (BL CL)      Latest      FirstToday      PreviousDay
This height estimates the cloudbase for extensive BL clouds (OverDevelopment), if such exist, i.e. if the OverDevelopment Potential parameter (above) is positive.  The BL CL (Condensation Level) is based upon the humidity averaged through the BL and is therefore relevant only to extensive clouds (OverDevelopment) - unlike the above surface-based LCL which uses a surface humidity.  [This parameter is truncated at 22,000 for plotting.]  MoreInfo
CAPE      Latest      FirstToday      PreviousDay
Convective Available Potential Energy indicates the atmospheric stability affecting deep convective cloud formation above the BL.  A higher value indicates greater potential instability, larger updraft velocities within deep convective clouds, and greater potential for thunderstorm development (since a trigger is needed to release that potential).  Note that thunderstorms may develop in regions of high CAPE and then get transported downwind to regions of lower CAPE.  Also, locations where both convergence and CAPE values are high can be subject to explosive thunderstorm development.   MoreInfo

Fundamental BL Parameters:

Boundary Layer Depth      Latest      FirstToday      PreviousDay
Depth of the layer mixed by thermals.  This parameter can be useful in determining which flight direction allows better thermalling conditions when average surface elevations vary greatly in differing directions.  MoreInfo
Surface Heating      Latest      FirstToday      PreviousDay
Heat transferred into the atmosphere due to solar heating of the ground, i.e. the heating that creates thermals.   MoreInfo

Other meteorological predictions from RUC model:

Maps of standard meteorological parameters from FSL forecast products webpage
Link to menu of traditional meteorological forecast maps, including cloud ceiling, precipitation, surface wind/gusts and 850/500mb winds.  However, area covered differs from BLIPMAP region.  This webpage also indicates FSL model forecast availability in both the upper right corner and via the button coloring, so if BLIPMAPS are not available you can use this link to determine the likelihood of a BLIPMAP appearing soon.  (Red for all forecast plots indicates the model is down, green for early forecast hours indicates a later forecast may be forthcoming, and all green indicates all forecasts should be available.)
Time-series of standard RUC meteorological parameters
Link to time series of traditional meteorological forecast variables, including cloud base, precipitation, surface wind, and CAPE.  Only available for METAR locations.  Users may find this page to be more useful than the FSL RUC forcast products webpage above, to determine the model-predicted cloud cover for example, since times are given as actual date/hour rather than as model forecast period.
Sounding profiles from FSL interactive sounding webpage
Link to webpage generating temperature, humidity, and wind profiles on a skew-T plot.  Interactive capability provides additional functions (if your browser has java available).


Description:

    BLIPMAPs predict thermal soaring conditions resulting from surface heating of the Boundary Layer (BL), the scientific term for the turbulent atmospheric region mixed by surface-based thermals (so thermal tops occur at the top of the BL).  The BLIPMAP program post-processes numerical weather model predictions to provide parameters suited to the needs of soaring pilots.  Relative differences, both in location and in time, are expected to be more reliable indicators of soaring differences than are the precise numerical values.
    A sequence of forecasts, all for the same validation time, is produced during the night.  The most important link is the first link on each line, "Latest", which gives the most recent (shortest term) forecast. The following "FirstToday" link gives the first forecast from the current day, which can be used to determine whether the model is significantly altering its predictions during the updating.  The last link, "PreviousDay", gives the last forecast from the previous day's prediction sequence, useful for those who want to compare their experiences from yesterday's flight to the BLIPMAP predictions. 
    The parameters are averages over 20km grid squares forecast by NOAA's Forecast Systems Laboratory RUC model BLIPMAPs are updated as new meteorological observations become available.  However, the 20km FSL RUC forecasts are only semi-operational so forecast files are not always available.  Additional information is available at the Info on First Available Times webpage
    The parameter values are represented by color hues which increase in "warmness" as the value increases in magnitude.  When many gradations are required, two cycles are made through the color wheel with "light" and "intense" tints respectively representing ranges of lower and higher magnitude. A screen magnifying tool, such as the freeware Super Magnify for Windows machines or Xzoom for X11/Linux/Unix machines, helps when discrimination between adjacent contours is difficult.
    State outlines are depicted on each BLIPMAP in white.  The RUC topography is plotted as black contours, at 500 ft intervals with thicker lines at 2000 ft intervals, to assist in location identification but also to emphasize the smoothed nature of the model topography.  The BLIPMAP does not predict thermal lift created by small-scale terrain features which are not resolved by the model topography, which often give localized updrafts significantly stronger than those over the surrounding smoother terrain.
    BLIPMAPs can also be viewed using a regional javascript BLIPMAP viewer, which creates a BLIPMAP image sequence. The viewer is most useful for quickly cycling between or through BLIPMAPs since the images exactly overlie - but some might just consider it simpler to use than this index page.

Notes:

    As with all weather products, users should check the date on each map for currency.  Small anomalous diamonds, the size of an individual model gridpoint, may appear in the plots, particularly for more sensitive parameters such as convergence or cloud parameters; these result from numerical noise and should be disregarded.
    The BLIPMAP is still in development and there will likely be problems, changes, and tweaks.  Opinions on factors affecting its usability are solicited. 

Medal     Heros:  We all thank FSL's Stan Benjamin for providing access to the 20km FSL RUC results.  A special BLIPMAP hero is Bill Hall of the Greater Boston Soaring Council who is presently hosting the BLIPMAP processing on his machine.  I also want to personally thank those whose support is listed on the Contributors webpage.

Link to the javascript BLIPMAP viewer for this region
Link to the BLIPMAPs for all regions
Link to the latest BLIP forecasts for individual locations
Link to pilot flight experiences using BLIPMAPs.
Link to on-line version of BLIPMAP SOARING article, a good read for beginning users
BLIPMAP Help webpage.

Link to the latest TIP forecasts for longer predictions at individual CA-NV locations
Link to the latest Upper-Air WINDIP forecasts for CA-NV
Link to the latest LWIP fine-scale wave forecasts for Lake Tahoe and Owens Valley regions
Link to DrJack's home page