Cessna 210 pilot reported a near-mid-air-collision with a glider that was not observed on adsb.

Attributes
ACN	1516240
Time
Date	201802
Local Time Of Day	1201-1800
Place
Locale Reference	NEW.Airport
State Reference	LA
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	Cessna 210 Centurion / Turbo Centurion 210C 210D
Operating Under FAR Part	Part 91
Flight Phase	Climb
Route In Use	Direct
Flight Plan	None
Aircraft 2
Make Model Name	Sail Plane
Operating Under FAR Part	Part 91
Flight Phase	Cruise
Person 1
Function	Pilot Flying Single Pilot
Qualification	Flight Crew Commercial Flight Crew Instrument
Experience	Flight Crew Last 90 Days 70 Flight Crew Total 6000 Flight Crew Type 5500
Events
Anomaly	Conflict NMAC
Miss Distance	Vertical 100

Narrative:

On climbout passing through 3000 feet I observed a glider aircraft pass 100 feet beneath me. Too late to take evasive action. The glider was white in color under a gray broken overcast which made it blend in with the horizon and impossible to see until coming very close. The area where the event took place was not identified on the sectional as a glider area which may have heightened my awareness. In the future I will be more vigilant on climbout for this type of situation. If this glider had been equipped with a transponder it should have shown up on my adsb; but it didn't.

Original NASA ASRS Text

Title: Cessna 210 pilot reported a near-mid-air-collision with a glider that was not observed on ADSB.

Narrative: On climbout passing through 3000 feet I observed a glider aircraft pass 100 feet beneath me. Too late to take evasive action. The glider was white in color under a gray broken overcast which made it blend in with the horizon and impossible to see until coming very close. The area where the event took place was not identified on the sectional as a glider area which may have heightened my awareness. In the future I will be more vigilant on climbout for this type of situation. If this glider had been equipped with a transponder it should have shown up on my ADSB; but it didn't.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.