A MD90'S #2 ENG EXCEEDED N1 AND EGT LIMITS. WX AVOIDANCE; TASK OVERLOAD AND FATIGUE CAUSED THE CREW TO MISS THE EVENT IN FLT. DURING POST FLT THE EXCEEDANCE WAS NOTED ALONG WITH A 4000 FT PRESSURE CHANGE WIND SHEAR.

Narrative

DURING A WX DIVERT FROM ZZZ1 (DUE TO TSTMS) TO ZZZ2 I NOTICED A MOMENTARY N1; OVERSPD ON ENG #2. I IMMEDIATELY RETARDED THE THROTTLE (AUTOTHROTTLES WERE ENGAGED). DUE TO HIGH COCKPIT WORKLOAD AND IMMEDIATE NEED TO AVOID NEARBY WX; MY ATTN WAS DIRECTLY BACK TO HDG; AIRSPD; AND SHORT-DISTANCE WX DEV/AVOIDANCE. THIS IS THE BEST OF MY RECOLLECTION AS TO WHEN EXACTLY THE OVERSPD MOST LIKELY OCCURRED; ALTHOUGH I AM NOT 100% CERTAIN. THE PROC FOR SUCH AN EVENT CALLS FOR A 'DOWNLOAD' OF ENG DATA (FROM THE ENG INST PANEL) PRIOR TO SHUTDOWN OF THE #2 ENG. IN THE BUSINESS OF THE SHORT DIVERT (ROUTINE; ATC CLRNC; WX AVOIDANCE; BRIEFING TO AN UNFAMILIAR AIRFIELD; COMS WITH FLT ATTENDANT; IAX; ATC; AND COMPANY; FOLLOWED BY ARRIVING AT A FIELD WITH UNKNOWN SUPPORT OR SVCS); I FAILED TO RECALL THE NEED TO ACCOMPLISH THE CHKLIST. WE DID; HOWEVER; ACCOMPLISH THE CHKLIST AFTER SHUTTING DOWN THE ENG AND PRIOR TO DEPARTING BACK TO ZZZ1. MAINT DISCOVERED A WINDSHEAR EVENT (4000 FT PRESSURE ALT CHANGE) AT THE TIME OF N1 OVERSPD. HUMAN FACTORS: POOR COM AND CRM COUPLED WITH HIGH COCKPIT WORKLOAD; POOR REST DURING PREVIOUS LAYOVER; AND FAILURE TO IMMEDIATELY RECALL NEED TO ACCOMPLISH THE CHKLIST PRIOR TO ENG SHUTDOWN. I RECALLED THE MOMENTARY EXCEEDANCE AFTER SHUTDOWN AND POSTFLT DUTIES HAD BEEN ACCOMPLISHED.