A a dispatcher released an oceanic flight with mdy as an ETOPS alternate but it was not legal becaus...

Narrative:

Released flight with ETOPS alternates of rjcc/mdy/cdb. Mdy (midway island) has NOTAM for ASOS not reporting visibility or altimeter setting; but had contacted mdy operations previously and had e-mail confirmation that they would provide observations during daylight hours. After the flight departed and airborne; looked at e-mail again and realized that they had also included in their e-mail that their observations would not include an altimeter setting. Per the jeppesen charts; all approaches into mdy require a local altimeter setting or they are not authorized. Flight not yet in ETOPS area of operations; and rjcc/cdb by themselves covered the ETOPS area of operations. Since rjcc/cdb covered the ETOPS area of operations; and flight had not yet entered ETOPS; contacted crew via ACARS and advised them to amend their release and removed mdy as an ETOPS alternate. Sent the crew a new ETOPS critical fuel summary based on just rjcc/cdb. Crew accepted amendment and pressed on.

Original NASA ASRS Text

Title: A a Dispatcher released an oceanic flight with MDY as an ETOPS alternate but it was not legal because of inadequate weather information. So while airborne; he altered the flight's ETOPS alternates.

Narrative: Released flight with ETOPS alternates of RJCC/MDY/CDB. MDY (Midway Island) has NOTAM for ASOS not reporting visibility or altimeter setting; but had contacted MDY Operations previously and had e-mail confirmation that they would provide observations during daylight hours. After the flight departed and airborne; looked at e-mail again and realized that they had also included in their e-mail that their observations would not include an altimeter setting. Per the Jeppesen Charts; all approaches into MDY require a local altimeter setting or they are not authorized. Flight not yet in ETOPS area of operations; and RJCC/CDB by themselves covered the ETOPS area of operations. Since RJCC/CDB covered the ETOPS area of operations; and flight had not yet entered ETOPS; contacted crew via ACARS and advised them to amend their release and removed MDY as an ETOPS alternate. Sent the crew a new ETOPS critical fuel summary based on just RJCC/CDB. Crew accepted amendment and pressed on.

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.

Attributes
ACN	1163677
Time
Date	201404
Local Time Of Day	1201-1800
Place
Locale Reference	ZSHA.ARTCC
State Reference	FO
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	Widebody Low Wing 2 Turbojet Eng
Operating Under FAR Part	Part 121
Flight Phase	Cruise
Route In Use	Oceanic
Flight Plan	IFR
Person 1
Function	Dispatcher
Qualification	Dispatch Dispatcher
Events
Anomaly	Deviation - Procedural FAR Deviation - Procedural Published Material / Policy Inflight Event / Encounter Weather / Turbulence

A a dispatcher released an oceanic flight with mdy as an ETOPS alternate but it was not legal because of inadequate weather information. So while airborne; he altered the flight's ETOPS alternates.