HEMS Tool - aviationweather.gov

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Matthew Rogers

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Matt R
Does anyone else use the HEMS Tool?
https://www.aviationweather.gov/hemst

Seems to be very powerful and a nice source of info, but I just discovered it and have not heard of it before. Check it out and let me know what you think and what it is missing.

It has weather/forecast -6hr/+6hr so it is not a good long term forecast, but looks great for a last look at the weather before going out.
 
I use "Aviation Weather from NOAA/NWS" app. It provides weather from all reporting airports, including TAFs where available.
 
Well it was designed for what I do (HEMS), so yes, I’m very familiar with it. It’s really designed for all aircraft operating below 5,000 ft.

It’s an excellent product for what we do because it provides a snapshot of our local and XC flying conditions. The color coding on ceiling and vis (flight conditions) can’t really be relied on but still gives a decent picture of what’s out there.

Unfortunately because of their precaution (ceiling & vis) statement and the FAA 8900.1, I can only use it as a sole source for a “no go.” A “go” decision must be made with supporting NWS products. I’ve written both AWC and the FAA to get that restriction lifted but have not heard anything back. What’s makes me laugh is, plenty of times I’m flying to a road intersection where there isn’t a AWOS / METAR in the entire county! But the FAA cares that I’m using a certified NWS product to decide how to get there. :rolleyes:
 
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So yes, that is what it seems like. Most GA flying is 5000' or less so it could be a good help.
 
I've been trying to remember to go look at it before I head for hangar.... I like it.... as Velocity said, a good tool for us lower and slower crowd.
 
The algorithm seems to work mostly off the AWOS/ASOS readings. It creates a 'blob' around the station and the shape of the blob is defined by the proximity of the next AWOS/ASOS.

Below is the output for eastern ND/western MN at this hour. That triangular 'blob' of LIFR is generated by a reading off the Moorhead,MN AWOS (200ft 1.5sm viz) even though the nearby Fargo,ND ASOS gives a MVFR reading (CLR 6sm viz). My mark1 eyeball tells me that I can see the tower lights at the interstate interchange two miles away. For anyone who has to rely on the tool, that triangular area south and west of Fargo is now a 'no-go' for HEMS operations although it may be a spurious reading, probably related to the 4in of powder we got last night.

hems_tool.jpg
 
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Matthew Rogers said:
So yes, that is what it seems like. Most GA flying is 5000' or less so it could be a good help.
Click to expand...

Some GA flying is 5000 msl or less. If the trip is 45 minutes or so each way, or it's really hot, I'll go to at least 6500 msl, and higher for longer trips.
 
Funny enough, that PDF document page was broken the day that Imfpund the HEMS Tool page. Tried to open it but was given a 404 error. Works now.
 
Hank S said:
Some GA flying is 5000 msl or less. If the trip is 45 minutes or so each way, or it's really hot, I'll go to at least 6500 msl, and higher for longer trips.
Click to expand...
I believe that the tool goes up to 5000’ AGL, not MSL. Makes a difference in some areas.
 
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