6-6 Figure 6-5. HEMS Satellite Imagery—Example
6.1.2.4 Icing.
The i cing severity product is a 3-D product and provides depictions at specified altitudes AGL at 1,000 ft-intervals up to 5,000 ft. In regions of steep terrain, these altitudes may have significant deviations from actual height above terrain given the limiting factor of grid cell size, which is approximately 13 km, and the resolution of the topography in the model. The icing severity product (see Figure 6-6, HEMS Icing Severity—Example) combines a multitude of weather observations (e.g., temperature, humidity, satellit e, observed surface weather and pilot reports, radar data) to diagnose areas of expected trace, light, moderate, and heavy icing. Separate overall icing probability (from 5 to 85 percent) (see Figure 6-7, HEMS Icing Probability—Example) i s provided as well.
These products originate from the Current Icing Product (CIP) and Forecast Icing Product (FIP) (see paragraph 5.21.1). These products start with data from the Rapid Refresh (RAP) model, which is run hourly. FIP has forecasts at 1, 2, 3, 6, 9, 12, 15, an d 18 hours. The time slider will use CIP for current and past times and time-adjusted FIP for future times.
Figure 6-6. HEMS Icing Severity-Example Helicopter Emergency Medical Services Tool INFO Feedback Weather Overlays View Configure 2023 UTC 8 May 2015 LSatellte
• None
•Flight Category celling Icing Severity >> OTUOU AGI @2000' AGL Icing Probability @3000' AGL Temperature >> @4000' AGL NOR TH D
•@5000' AGL Rel Humidity >> Wind speed >> OREGON
NEBRASKA Denver af 200 KANSAS ALL 200 mil Icing Severity at 5000 AGL NITED STAT E S RAP Windbarb at 5000'AGL SIGMET FIt Cat: •MVFR • IFR • LIFR PIREP Turb: ALGT AMOD A SEV PIREP Ice: LJ LGT / MOD (H/ SEV Trace Light Moderate Heavy
HEMS PDD The severity is colored in shades of blue, with the lightest for trace and the darkest for heavy.
Figure 6-7. HEMS Icing Probability- -Example Helicopter Emergency Medical Services Tool INFO Feedbac Weather Overlays Configure 2023 UTC 8 May 2015 Satellite Jone Flight Category ) Ceiling Visibility Icing Severity >> Icing Probability @1000' AGL 02000 ACL Temperature >> OSUOU AGL Rel Humidity >> 04000 AGL
•@5000' AGL Wind speed >>
ORE GOI
NEBRASKA Devel Kansas
ETED STAT ES AL 200 mi Icing Probability at 5000'AGL RAP Windbarb at 5000'AGL
SIGMET CWA GAIRMET FIt Cat: •MVFR • IFR • LIFR PIREP Turb: \ LGT AMOD A SEV PIREP Ice: L LGT (/ MOD ( SEV 15 25 35 45 55 65 75
HEMS PDD The probability is colored in shades starting at blue (5 percent), through yellow (50 percent), to orange (>75 percent).
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6.1.2.5 Temperature, Relative Humidity, and Wind Speed.
Temperature (see Figure 6-8, HEMS Temperature-Example), relative humidity (see Figure 6-9, HEMS Relative Humidity-Example), and wind speed data (see Figure 6-10, HEMS Wind Speed with Windbarb-Example) is derived from the AGL grids provided as part of the RAP model output.
Data are presented on 1,000 ft AGL increments to 5,000 ft. These grids are available from the RAP model output every hour and forecasts run 7 hours into the future. If the time slider is moved into the past, the RAP analysis for that hour is shown.
Figure 6-8. HEMS Temperature-Example Helicopter Emergency Medical Services Tool INFO Feedback Weather Overlays View Configure 1605 UTC 7 May 2015
• Satellite
- Radar
• None
• Flight Category.
• Ceiling
• Visibility.
Icing Severity >> Icing Probability >> Temperature >> @1000 AGL Rel Humidity >> • @2000' AGL Wind speed >> • @3000' AGL
• @4000' AGL
• @5000' AGL Source: Esri 500 km 500 mi RAP Temperature at 5000'AGL RAP Windbarb at 5000 AGL
SIGMET CWA FIt Cat: •MVFR • IFR O LIFR PIREP Turb: ALGT AMOD A SEV PIREP Ice: LJ LGT (/ MOD (p) SEV -40-30-20-10 0 10 30 The temperature data are colored from blues for the coldest temperatures to reds for the warmest. Delineation between light blue and yellow is used to show the freezing level.
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Figure 6-9. HEMS Relative Humidity-Example Helicopter Emergency Medical Services Tool INFO Feedback weather Overlays View Configure 1605 UTC 7 May 2015 .. Satellite Radar O None
• Flight Category
• Ceiling
• Visibility Icing Severity >> Icing Probability >> Temperature >> Rel Humidity >> @1000 AGL Wind speed >> • @2000' AGL
• @3000 AGL
• @4000' AGL
• @5000' AGL Source: Esri 500 km 500 mi RAP Rel humidity at 5000 AGI RAP Wingbarb at 5000 AGL
SIGMET CWA FIt Cat: •MVFR • IFR O LIFR PIREP Turb: ALGT A MOD A SEV PIREP Ice: LJ LGT / MOD H SEV 10 20 30 40 50 60 70 80 90 The humidity data are colored from oranges for very dry, to yellow for 50 percent, to dark green for near 100 percent. Oranges would be more indicative of clear skies while greens would show cloud or low-visibility areas.
Figure 6-10. HEMS Wind Speed with Windbarb-Example Helicopter Emergency Medical Services Tool INFO Feedback weduen Overlays View Configure 1607 UTC 7 May 2015
• Satellite
- Radar O None
- Flight Category
• Ceiling © Visibility..
Icing Severity >> Icing Probability >> Temperature >> Rel Humidity >> › @1000' AGL
• @2000' AGL
• @3000' AGL
• @4000' AGL _ Sourde: Esri 500 500 mi RAP Wind speed at 5000 AGL RAP Wing barb at 1000 AGL FIt Cat: •MVFR • IFRO LIFR PIREP Turb: ALGT AMOD A SEV PIREP Ice: LJ LGT / MOD (/ SEV 45 60 75 The wind speed data are colored from blues for the lightest winds to light green for stronger winds.
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6.1.2.6 Dat a Overlays.
The HEMS Tool allows the user to select multiple fields to be overlaid on the grids including: METARs/TAFs, Flight Category, PIREPs, Windbarbs, SIGMETs and G-AIRMETs (Graphical Airmen’s Meteorological Information), CWAs, and NWS hazards. These fields may be selected on or off in the drop-down Overlays menu. Figure 6-11, HEMS Data Overlays with Text METAR—Ex ample, is an example.
6.1.2.6.1 METARs/TAFs.
The METAR observations plotted using the standard station model where temperature, dewpoint, winds, altimeter setting, weather, ceiling, and visibility are displayed around the station location.
T he data plotted comes from the latest available observation, including Special Weather Reports (SPECI). The stations displayed follow a progressive priority scheme that will show more stations depending on how far the user zooms in. This density can be changed through the Configuration menu. If the time slider is moved into the past, the nearest observation before the listed time is displayed. If the slider is moved into the future, the TAF for that station is shown. It should be noted there are fewer TAF stations than available METAR sites. More configuration options are available, including parameters displayed, scale factor of graphic, and whether the TAF is included in the pop-up display.
6.1.2.6.2 Flight Category.
This displays only the flight conditions at a particular airport as a colored dot.
The flight category display uses the same priority filter system as the METAR plots, but the density is much higher.
6.1.2.6.3 PIREPs.
This displays turbulence and icing PIREPs. The default is to show only PIREPs reported in the last 90 minutes, and only those below 12,500 ft. These options can be changed in the Configuration menu.
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6.1.2.6.4 SIGMETs.
This displays the current valid SIGMETs. This will show both domestic and international SIGMETs. Individual SIGMET types can be toggled on and off through the configuration menu. SIGMETs can be distinguished by their red outline and red labels.
6.1.2.6.5 G-AIRMET.
This displays the current valid G-AIRMETs. This will show all G-AIRMET types, which can be cluttered. Each type can be toggled on and off through the Configuration menu.
6.1.2.6.6 Center Weather Advisories (CWA).
This displays the CWA issued by the Center Weather Service Units (CWSU) at each Air Route Traffic Control Center (ARTCC). CWAs can be distinguished by the black outline and black labels.
6.1.2.6.7 NWS Hazards.
This displays all current warnings, watches, and advisories. The Configuration menu will allow the user to select “Warnings” which will only show tornado, severe thunderstorm, blizzard, winter storm, and ice storm warnings.
6.1.2.6.8 Windbarbs.
This displays windbarbs from the RAP model based on the height selected through one of the weather displays (CVA, Icing and RAP temperature, relative humidity (RH), and wind speed). If the user selects temperature at 2,000 ft AGL, the display would also show the winds at 2,000 ft AGL. The windbarbs are filtered based on zoom level. As the display is zoomed in, more windbarbs will show.
Figure 6-11. HEMS Data Overlays with Text METAR-Example Helicopter Emergency Medical Services Tool INFO Weather Overlays View Configure 1625 UTC 7 May 2015 -A SPER • METAR/TAF
• FItCat 45
• PIREP
• SIGMET
• G-AIRMET
• CWA
- NWS Hazards
• Windbarb
• Highways
• Roads
- Counties IN ACE PR RNO
• Top Jetroutes
• ARTCC Boundaries
- Nav Aids
• Airports Runways
OLORADO
PL A TA OU 'MEX 100 mil 28 || KTCS
SIGMET CWA GAIRMET E FIt Cat: OMVFRO IFRO LIFR PIREP Turb: ALGT AMOD A SEV PIREP Ice: L LGT If MOD | SEV Note: Text information from these fields can be accessed by clicking on the station or in the polygon, or by selecting "hover" in the Configure menu and scrolling the mouse over the area of interest.
Data can be customized in the Configure menu (see Figure 6-12, Configure Menu-Example). The user can select the type of background map; the level of transparency for the weather overlays; the types of SIGMETS, G-AIRMETs, PIREPS, and NWS hazards they wish to view; the preferred satellite view; and the density of observations.
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Figure 6-12. Configure Menu-Example Helicopter Emergency Medical Services Tool INFO Feedback Weather Overlays View Contigure 1619 UTC 7 May 2015 Map >> Satellite >> Radar >> Weather >> METAR/TAF >> Parameters visible:
Flight Cat >> All • Temp Wind Alt PIREP >> • Vis OWx • Cover • Ceil SIGMETS >> None Dew OWgst • Id G-AIRMET >> Density: 0 Scale: 1 Hazards >>
• Hover • Include TAF • Decoded METAR ÍCO 100 km / 995 A RAW E 69 100 mil KROW
SIGMET CWA GAIRMET FIt Cat: •MVFR • IFRO LIFR PIREP Turb: ^ LGT AMOD SEV PIREP Ice: LJ LGT / MOD (/ SEV
6.1.2.7 ESRI Basemaps and Overlays.
The HEMS Tool has high-resolution basemaps for the entire United States.
More detail is revealed as the user zooms in. The user can select their preferred Environmental Systems Research Institute (ESRI) basemap through the HEMS Configure menu. Options include Terrain, Road, or Satellite, and the user can select a light, dark, or simple map background. The default basemap is the ESRI Terrain view.
Map overlays include highways, roads, counties, top jet routes, ARTCC boundaries, Navigation Aids (NAVAID), airports, and runways. These can be toggled on or off in the Overlays menu.
6.1.3 Strengths and Limitations.
6.1.3.1 HEMS Strengths.
1. One-stop shop for multiple data fields.
2. Focused on low-altitude flights common to HAA.
3. Simplified display for non-meteorologist users.
4. Available 24 hours a day, 7 days a week.
6.1.3.2 HEMS Limitations.
1. Due to limitations of the observations, the ceiling, visibility, and flight category grid cells are approximately 5 km apart. In data 6-13
6-14 sparse regions, the best possible estimate of ceiling and visibility is assumed from the nearest surrounding data and may not represent the actual conditions at a specific point.
2. Due to limitations of the radar, such as blockage by mountains, spacing of radar locations and over processing of clutter and AP, there may be precipitation when radar data does not detect or show a complete weather picture. The most commonly seen example is very shallow clouds with light precipitation, like freezing drizzle or snow. An excellent website with more information concerning radar technology and limitations is found at the NWS JetStream-Online School for Weather, under Radar Frequently Asked Questions (FAQ).
3. In regions of steep terrain, AGL altitudes may have significant deviations from actual height above terrain, given the limiting factor of grid cell size, which is approximately 13 km, and the resolution of the topography in the model.
6.1.4 Use.
The HEMS Tool has been specially designed to meet the needs of emergency first responders flying short-distance, low-altitude flight routes. This tool is not designed for General Aviation (GA) or commercial flights and does not constitute an official weather brief.
6.2 Flight Path Tool.
6.2.1 Description.
The FPT is a comprehensive, interactive, geographical display that brings together all of the weather products available at https://www.aviationweather.gov/flightpath. It runs as a Java desktop application on your computer for maximum performance.
The Flight Path Tool can overlay multiple fields of interest: icing (probability, severity, and Supercooled Large Drops (SLD)), turbulence potential, Convective diagnosis and forecast, ceiling, visibility, flight category, winds, relative humidity, temperature, radar (base and Composite Reflectivity), satellite observations (visible, infrared (IR), and water vapor wavelengths), AIRMETs and SIGMETs, METARs, TAFs, and PIREPs.
All 3-D data can be sliced horizontally at selected flight levels or vertically along a flight path. All data can be animated in time.
The tool lets you zoom in to any location on the globe. It automatically switches to the most appropriate projection for the viewed area. High-resolution base maps show selectively more detail as you zoom in.
In addition, the FPT can create vertical cross sections along your flight route.
Preferred views can be saved for quick recall later.
Discussion Credit: NOAA/NWS/AWC.
Figure 6-13. Flight Path Tool-Icing Severity Example (Image Credit: AWC) View Configure
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• Icing SLD
• Icing Severity
- Data Overlays _ Wind Barbs 6-15
Figure 6-14. Flight Path Tool-Windbarbs Example (Image Credit: AWC)
• Flight Path Tool (Default Configuration) File View Configure
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8.000 4,000 2,000 eet Valid at 05/03/17 182 cing Severit 2 hrtosttor 10000 Feet Valid at 05/0347 18z None Icing Severity 15:30Z 16:302 19:30Z 21:00Z 22:30Z 0:00Z 1:30Z 3:00Z 5/3 514 Data Layers Available Data Sets
• Wind Barbs •
• METARs — PIREPs
• AIR/SIGMETs 6-16
Figure 6-15. Flight Path Tool-Cross Section Example (Image Credit: AWC)
• Cross Section File View Configure
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