Here is a incomplete list of...
excuses for why that great lift did not materialize
like you planned, maybe even for the better:
Thermals: |
Mitigation/ |
Surface Heating |
|
| Obscuring of Sunlight, haze in the atmosphere, cirrus or other high clouds, humidity, smoke, pollution, mountain shadows for morning or afternoon. | High
resolution 1km/pixel satellite images. Animations show progression/movement. GEOS High Resolution Satellite images Geostationary Satellite Server Western US |
| Slow to heat day - often due to the sun's energy being used to burn off dew or moisture on the surface. Rain or wet ground. Snow cover reflects the sunlight. Fog/low cloudcover to burn off. | |
| Overdevelopment - too many cu build and block off the sun | OvercastDevelopment
Potential OvercastDevelopment Cloudbase (BL CL) |
| Thunderstorms |
CAPE
blipmap
CAPE Unisys CAPE K index, Lifted Index |
| Terrain influences, terrain that faces into the sun, or stays in shadows, or terrain height as many thermal related dynamics are AGL related rather than MSL. | |
Clouds |
|
| Blue or Cu - the key question on how confident you can fly |
COMPOSITE:
Cumulus Cloudbase for Cu Potential > 0 |
Winds |
|
| Surface Wind too light to kick off thermals, or wind too strong tearing apart thermals. | Buoyancy/Shear Ratio (B/S) |
| BL Convergence | BL Convergence |
| Wind Shear in the Boundary Layer | Wind Shear in the Boundary Layer |
| Wave suppression, wave above will enhance and suppress thermals in different zones. In 2006 the Cordele regionals day 1 was supressed by wave action, and Cordele GA is in the coastal plains well away from mountains, and it was mid-May not winter. | |
Stability |
|
| Stable sea breeze moves in under your courseline and kills the lift. | |
| Cloud cover at night traps in the day's heat, causing a stronger inversion to cap the lift. | |
| Building of high or low pressure. | |
| soundings:
Thermal Index Interactive SkewT soundings |
|
Forecast Model |
|
| Fronts in different position/timing than the computer model expects at time of flight. | Current
Frontal Analysis Plot Current Regional Surface Map |
| Virga or false rainfall/precipitation reflection on radar. The false readings on radar could cause computer models to assume the ground is wetter. | look at webcams to see if it is really raining, check local sources Georgia Webcams |
| Missing/obsolete/incorrect data in the computer forecast model. |
Check
forecast from several models AVN/ETA/RUC
etc |
| Forecast high temperature wrong. Sometimes the lift strength is very sensitive to 1 or 2° F changes, depending on the curve of the temperature profile. Forecasts are of limited accuracy for the exact high temperature for many reasons. | Check forecast from several models AVN/ETA/RUC etc |
Other |
|
| Daylight savings time, suntime not matching what you have on your watch. Each fall and spring you may need to recalibrate your expected timing to the new time setting. Similar things can happen when flying at extreme ends of timezones such as Marfa Texas at the far western end of Central Time Zone. | |
Ridge: |
|
| If Thermals do not trigger then often the higher wind speed airmass can just fly over the terrain. When thermals are active the upper and lower airmasses are "connected" allowing the higher speed upper level winds drag the surface level airmass along with it. | soundings:
Thermal Index Interactive SkewT soundings |
|
|
|
Wave: |
|
| The right stacking of stable and instable layers does not exist. | soundings:
Thermal Index Interactive SkewT soundings |
| Position of the jet steam | National
Jet Stream Chart Jet Stream Position Unisys NAM 300 mb Plot Jet Stream Analyses & Forecasts at 300 mb |
| Moisture moves in and creates a layer that you cannot climb up through or more dangerously down through if it develops suddenly. | soundings:
Interactive SkewT soundings |
Other links: |
Weather Archives |
| Can I obtain old BLIPMAP forcasts ? Two archive viewers are available: (1) NAM+RUC Archive Viewer can plot both NAM and RUC model archives, (2) RUC Archive Viewer with IGC overlay can plot only RUC model archives has the ability to overlay them with an IGC file trace. [from Dr Jack]. |
| Daily Forecast Map (National) from NCEP (2001 - to present) |
| Daily Surface Map w/ Fronts & Isobars from NCEP (2002 - to present) |
| Satellite Images: California Regional Weather Server - San Francisco State University |
| Weather Archives - Data and Maps |
| Observed Weather data DAILY CLIMATE REPORT - issued daily: Detailed daily weather statistics (usually for yesterday), including temperature, precipitation, degree days, wind, humidity, sunrise/sunset, and record temperature data for the following day. Precipitation data includes both calendar year and water year totals, percent of normal values, and comparisons to normal. This product is available for up to 2 months.GA, Middle AL North AL Middle TN Eastern TN |
| METARS (observations) for past 48 hours Courtesy Texas A&M |
| past weather information NOAA |
| Near-Surface Forecast Verification Statistics for Operational NCEP models: 2004-present Explaination |
| NOAA NWS NCEP REANALYSIS DATA DISPLAY BY NCEP HPC |
| U.S. Climate at a Glance |
Other tools to build comparisons between |
| HTTrack is a free (GPL, libre/free software) and easy-to-use offline browser utility. It allows you to download a World Wide Web site from the Internet to a local directory, building recursively all directories, getting HTML, images, and other files from the server to your computer. |
| BMapper is a program that overlays BLIP data (http://www.drjack.net/), onto any geographic projection raster map (BMP format) with known coordinates. The program comes with background maps similar to the above map. Additionally, BMapper allows screen capture of the background map from other programs you may own such as SeeYou and Delorme. |
| Forecast Verification - Issues, Methods and FAQ |
This has just begun, help me complete the incomplete list... contact:
2014-05-31
