Narrative:

During patient drop-off, called FSS and got a full briefing for the return leg. Told crew that it would be at least 30 mins before the rain cells that we encountered moved far enough east before attempting to return. Time had passed and crew had to clean the aircraft, so all went up to the helipad (18 stories up). While crew cleaned the aircraft, I called FSS again for a full update on WX en route. All major reporting points were reporting good VFR with lowest ceilings to be around 2100 ft and visibilities all around 8 mi in light rain. Western edge of the moderate rain was just east of ZZZ moving easterly and briefer stated that it looked pretty decent if I stayed west of the highway line south, which is our normal flight path between those points. Visibility on rooftop was better than 8 mi in all directions, so we departed and stayed with approach control during entire flight. En route cruise altitude stayed around 1500 ft with visibilities of 8 mi or better. XXX approach handed me off to ZZZ1 approach control and right after initial contact with them, went inadvertent IMC. Already in level flight, started a half standard rate turn trying to reverse course and head back to XXX. Did not climb for freezing levels were forecasted down to 3000 ft. Focused on flying the aircraft first. At this point, was in between approach agencies, barely in radio contact. As I was making contact with XXX approach to declare an emergency, broke out into VFR conditions. Total IMC lasted approximately 3 mins. Told approach of my intentions. Was over the lights of the city of ZZZ at this point in VFR conditions. Descended below 1000 ft briefly over the city once to maintain clear clouds/fog bank but other than that, remainder of the flight back to YYY was greater than 1000 ft 3 DME with flight following from approach control.

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Original NASA ASRS Text

Title: AFTER WAITING FOR THE WX TO IMPROVE AND ACQUIRING A DETAILED BRIEFING FROM FSS, A HELI PLT STILL ENCOUNTERED IMC WX ON HIS VFR FLT TO HIS HOME BASE.

Narrative: DURING PATIENT DROP-OFF, CALLED FSS AND GOT A FULL BRIEFING FOR THE RETURN LEG. TOLD CREW THAT IT WOULD BE AT LEAST 30 MINS BEFORE THE RAIN CELLS THAT WE ENCOUNTERED MOVED FAR ENOUGH E BEFORE ATTEMPTING TO RETURN. TIME HAD PASSED AND CREW HAD TO CLEAN THE ACFT, SO ALL WENT UP TO THE HELIPAD (18 STORIES UP). WHILE CREW CLEANED THE ACFT, I CALLED FSS AGAIN FOR A FULL UPDATE ON WX ENRTE. ALL MAJOR RPTING POINTS WERE RPTING GOOD VFR WITH LOWEST CEILINGS TO BE AROUND 2100 FT AND VISIBILITIES ALL AROUND 8 MI IN LIGHT RAIN. WESTERN EDGE OF THE MODERATE RAIN WAS JUST E OF ZZZ MOVING EASTERLY AND BRIEFER STATED THAT IT LOOKED PRETTY DECENT IF I STAYED W OF THE HWY LINE S, WHICH IS OUR NORMAL FLT PATH BTWN THOSE POINTS. VISIBILITY ON ROOFTOP WAS BETTER THAN 8 MI IN ALL DIRECTIONS, SO WE DEPARTED AND STAYED WITH APCH CTL DURING ENTIRE FLT. ENRTE CRUISE ALT STAYED AROUND 1500 FT WITH VISIBILITIES OF 8 MI OR BETTER. XXX APCH HANDED ME OFF TO ZZZ1 APCH CTL AND RIGHT AFTER INITIAL CONTACT WITH THEM, WENT INADVERTENT IMC. ALREADY IN LEVEL FLT, STARTED A HALF STANDARD RATE TURN TRYING TO REVERSE COURSE AND HEAD BACK TO XXX. DID NOT CLB FOR FREEZING LEVELS WERE FORECASTED DOWN TO 3000 FT. FOCUSED ON FLYING THE ACFT FIRST. AT THIS POINT, WAS IN BTWN APCH AGENCIES, BARELY IN RADIO CONTACT. AS I WAS MAKING CONTACT WITH XXX APCH TO DECLARE AN EMER, BROKE OUT INTO VFR CONDITIONS. TOTAL IMC LASTED APPROX 3 MINS. TOLD APCH OF MY INTENTIONS. WAS OVER THE LIGHTS OF THE CITY OF ZZZ AT THIS POINT IN VFR CONDITIONS. DSNDED BELOW 1000 FT BRIEFLY OVER THE CITY ONCE TO MAINTAIN CLR CLOUDS/FOG BANK BUT OTHER THAN THAT, REMAINDER OF THE FLT BACK TO YYY WAS GREATER THAN 1000 FT 3 DME WITH FLT FOLLOWING FROM APCH CTL.

Data retrieved from NASA's ASRS site as of July 2007 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.