Regional   Atmospheric   Soaring   Prediction
BLIPMAP FORECASTS
For Great Britain
Using a locally-run WRF model with 4, 5 & 12 km horizontal resolution and 52 vertical levels
BLIPMAP™ = Boundary Layer Information Prediction MAP
Created by Dr. John W. (Jack) Glendening, Meteorologist 

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DISCLAIMER
Site maintained by Paul Scorer
Comments to p.scorer_at_leedsmet.ac.uk

Page Last updated Thu Apr 8 14:33 BST 2010

IMPORTANT - EUROCONTROL PROPOSALS

The British Gliding Association, along with its airsports colleagues throughout Europe,
are extremely concerned about Eurocontrol’s proposals to standardise the rules of the air throughout Europe.
The proposals call for the removal of decades of appropriate and sensible national modifications and differences to the ICAO Rules of the Air.
These national differences - as seen for example in the UK ANO and in the series of exemptions put in place by UK CAA - are appropriate and safe
and to remove them will seriously damage gliding in particular and airsports in general.

The BGA response is available at the BGA Consulation Page

RASPtable is the simplest interface to all Parameter Maps. See the Introduction for usage.

PLEASE CHECK THE DATE AT THE TOP OF EACH MAP, AS THE SYSTEM IS SUBJECT TO GLITCHES.

The Status Check indicates if any run error was detected.

Please note that the Location of the LAND-SEA BOUNDARY is approximate.

Interpretation

Frequently Asked Questions (pdf format)

A link to some Webcasts on using RASP.
They have been done by some Paraglider people, and are hosted by Judith Mole.
Many Thanks to you all.
They are of general applicability, and include an excellent introduction to Soundings.


Below are some links to papers by Jean Oberson, a RASP maintainer in Switzerland.
They are, naturally, focussed on his site, but hopefully useful in the UK.
Note also that there are functional differences from RASP-UK,
for example my Sounding Locations on the map are not clickable - but I do have "Soundings Anywhere"

For more Information about the data in the maps, see DrJack's Website and especially the Parameter Descriptions

BlipSpot Maker provides text parameter values for all forecast times at a location.
You can also get a Sounding. You can copy the URL and add to your Favourites list.

Track Average indicates if a task specified by BGA Trigraphs is achievable

Track Start Time indicates the best time to start a task.
WARNING: it is very slow!

Note: Climb Rates are now in Knots

Wind Tool indicates whether Ridge Sites are expected to work

Experts may prefer a file-list interface to the Forecast Maps from the Day links below.
Today (12Km)    Monday    Tuesday   Wednesday   Thursday   Friday   Saturday   Sunday

The schedule explains what happens each day,
and indicates when forecasts are updated.

Thanks to:


FURTHER INFORMATION  (Links are to DrJack's Website; The Words are his too!)

Overview
      These forecasts are intended to help the meteorology-minded pilot better evaluate soaring conditions.  The maps are particulalry useful to cross-country soaring pilots, since they allow evaluation of conditions away from the home field.  Utilizing the forecasts can require some self-education (though that can't be too hard since over 2000 US pilots actively use BLIPMAPs in the US) as individualized assistance is not provided.  At first glance the website can seem intimidating since so many parameters are forecast - but most are "supplemental" forecasts to be used as needed and many users normally look only at the three or four they have found to be most useful, such as the expected lift strength or the maximum (dry) thermalling height or cloud potential/height forecasts, looking at additional parameters only under special conditions. 

How are these RASP forecasts produced ?  
      My traditional RUC and ETA BLIPMAP forecasts are obtained by post-processing forecast files output from NCEP prognostic models, so horizontal and vertical resolution is determined by that used in those models.  Here I am instead running a prognostic model myself, so am able to specify the vertical/horizontal grid (though of course subject to limits of practicality).  A WRF (Weather Research and Forecasting) model is being initialized and marched forward in time at 180 second time intervals to produce forecasts at 3 hr increments.  Initial and boundary conditions come from the larger-scale models run by NCEP, in this case from the GFS model having a resolution of around 100km.  To increase accuracy, forecasts are produced for three different grids:  a large-domain coarse-mesh grid (36 km), a 12 km grid nested inside it, and a small-scale fine-mesh 4km grid within that (but only results for the latter two grids are presented).  Since the data needed to make such runs is available globally, the forecasts can be made for anywhere in the world. 

Notes and Caveats: 
()  One is not supposed to believe all the details of these forecasts, particularly since the smallest-scale structure is constantly changing yet one a few snapshots at different times are shown.  Rather, one should be looking for patterns. 
()  Forecasts for points close to the boundary will be less accurate than for those located nearer the center of the domain, due to inevitable mis-matchings between the coarse and fine grids.  In particular, predictions of max/min BL vertical velocity are very noisy and inaccurate near the boundary (particularly where boundary condition problems exist).  To remind users of this, a dotted line marks the "frame" outside of which coarse-fine boundary interaction problems are most prevalent. 
()  The "Explicit CloudWater Cloudbase" estimates are based on cloud water predicted from internal model equations and problematical since there is no simple criterion for differentiating "mist" concentrations from "cloud" concentrations.  The criterion presently used is a first guess. 
()  The "Cu Potential" and "Sfc. LCL" predictions are based on a simple formula which considers only water vapor at the surface
()  This model does not ingest as much observational data as do the institutional models such as RUC and ETA, hence some effects are not included. 
()  The fact that these forecasts are only a snapshot in time of a fairly noisy field should be particularly emphasized for the 4 km resolution forecasts, as forecasts for, say, 30 minutes before or after would look different.  At this point it's difficult to figure how much value they really add anything, but one never knows til one tries. 
()  The "Vert. Velocity at 850mb (or 700mb or 500mb)" and "Vert. Velocity Slice at Vert.Vel.Max" parameters attempt to forecast mt. wave events, although strong vertical velocities resulting from deep BL convergence can also be found in the plots.  The first parameter gives a plan view of vertical velocity at the 850mb level, a height of roughly 1500 m MSL and thus often above the BL top.  The second parameter is a vertical slice taken at a point of maximum vertical velocity (as found at a height of approximately 1500 m AGL within a horizontal box which excludes ane outer edge of the domain; the position of that slice is indicated by a dotted line on the plot of the first parameter (with left-right on the slice always being left-right on the plan view).  A label above the plots gives the location and magnitude of the found maximum value.  Mt. wave predictions are best made using resultions no larger than 4km, since a coarser grid generally does not resolve the waves accurately. 
()  Time loops are provided to illustrate the variability, and hence uncertainty, over a 3 hour period.  Unfortunately the color scales are not identical for all maps in the loop, but generally they are roughly comparable.