WINDSHEAR. GAR.

Narrative

DURING APCH (ILS DME RWY 13 LGA) BTWN 1000-800 FT MSL; THE 'WINDSHEAR' VISUAL (ADI) AND AURAL WARNINGS WENT OFF. WINDS WERE GUSTY; WITH SOME MODERATE TURB; BUT APCH WAS STABLE. LNDG CHK HAD BEEN COMPLETED. SURFACE WINDS WERE 150-170 DEGS AT 24 KTS; GUSTING TO 33 KTS. AIRSPD FLUCTUATIONS WERE NO MORE THAN PLUS OR MINUS 10 KTS. AS PER COMPANY PROC; A GAR WAS INITIATED. BTWN 1500-2000 FT MSL; AIRSPD BEGAN FLUCTUATING PLUS OR MINUS 15 KTS OR MORE AND A BRIEF STICK SHAKER WAS HEARD. ACFT HAD NOT BEEN CLEANED UP AT THIS POINT; AS PER WINDSHEAR TECHNIQUE. ABOUT 2000 FT ACFT BEGAN DSNDING AND VSI WENT TO 1000-1200 FPM DOWN. AIRSPD THEN INCREASED IMMEDIATELY 40 KTS IN AN 'INCREASING' TYPE OF WINDSHEAR. AT 1600 FT MSL VSI WAS INCREASED TO A CLBING RATE 1000 FPM AND THE AIRSPD STABILIZED. AFTER FLYING OUT OF WINDSHEAR ACFT WAS CLEANED UP AND GAR WAS CONTINUED. WE RPTED WINDSHEAR TO TWR DURING OUR GAR; BUT NO OTHER ACFT RPTED THIS WINDSHEAR. SUBSEQUENT APCH AND LNDG; ALBEIT TURBULENT; WAS STABLE AND UNEVENTFUL. NO FURTHER WINDSHEAR WARNINGS OCCURRED. I BELIEVE THE WINDSHEAR DETECTION; ALERT; AND GUIDANCE SYS ON OUR ACFT WAS GIVING US A WARNING THAT MIGHT OTHERWISE BEEN DISCOVERED TOO LATE.