php - ereg to preg_match conversion - getting barometer -

I need some help in changing an old ERR expression to preg_match. I am the barometer from the airport METAR (altimeter ).

  ereg ('^ (a | q) ([0- 9] {4})', $ part, $ pieces)   
 expression above I need to convert to preg_match. I tried it for the following, but it gives '0'.  
  preg_match ('/ ^ (A) ([0- 9] {4}) /', $ metar)   
 Unrecognized persons of MATAR For, it seems:  Clax 230353 J 26007 KT9 SM BKN 2009 9/16 A2 99 85 RMK AO SLP105 T01890161  is the Ultimate  A2985 .   
 
 
 You must remove the initial anchor  ^   
  if (preg_match ('/ ([AQ]) ([0- 9] {4}) /', $ meter, $ match) print_r ($ match);   
 Note that for more security, you can add word limits:  
  if (preg_match ('/ \ b ([AQ]) ([0- 9] {4}) \ B / ', $ meter, $ match) print_r ($ match);