Narrative:

Obtained destination FSS forecast by land line from ZZZZ 4 hours prior to ETA ADIZ. Storm system leaving area; 4400 ft broken; 2200 ft scattered; 10 NM visibility wind westerly at 6 KTS; at destination. Flying VFR on top at 12500 ft to clear occasional cumulus clouds. Approximately 60 NM south of the border; unable to get ZZZ1 FSS for IFR border crossing clearance. Passed through thin tops of cumulus clouds; then passed through one and didn't come out to the sunny skies as forecast. I was in a thunderstorm with severe turbulence; windshield and wing icing and fluctuating airspeed indicator -- then to zero. Not planning on WX at that point; the pitot heat was off. Turning it on quickly brought the airspeed back to normal. Prayers answered. I didn't want to descend for warmer air because I was approaching the ZZZ2 airspace. Finally contacted ZZZ2 approach; received clearance to 9000 ft and passed me on to ZZZ1 approach. They vectored me to the VOR approach to ZZZ1. My concern is that I was flying a single engine aircraft in foreign country in IMC conditions (against their rules). The forecaster really missed it. Actually it was a circular storm that came back around again and again for two more days. Still; my responsibility.

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Original NASA ASRS Text

Title: A VFR SINGLE ENG ACFT PLT ENTERED A TSTM AND EXPERIENCED ICE; SEVERE TURB; AND LOSS OF AIRSPD INDICATOR.

Narrative: OBTAINED DEST FSS FORECAST BY LAND LINE FROM ZZZZ 4 HRS PRIOR TO ETA ADIZ. STORM SYSTEM LEAVING AREA; 4400 FT BROKEN; 2200 FT SCATTERED; 10 NM VISIBILITY WIND WESTERLY AT 6 KTS; AT DEST. FLYING VFR ON TOP AT 12500 FT TO CLR OCCASIONAL CUMULUS CLOUDS. APPROX 60 NM S OF THE BORDER; UNABLE TO GET ZZZ1 FSS FOR IFR BORDER CROSSING CLRNC. PASSED THROUGH THIN TOPS OF CUMULUS CLOUDS; THEN PASSED THROUGH ONE AND DIDN'T COME OUT TO THE SUNNY SKIES AS FORECAST. I WAS IN A THUNDERSTORM WITH SEVERE TURB; WINDSHIELD AND WING ICING AND FLUCTUATING AIRSPEED INDICATOR -- THEN TO ZERO. NOT PLANNING ON WX AT THAT POINT; THE PITOT HEAT WAS OFF. TURNING IT ON QUICKLY BROUGHT THE AIRSPEED BACK TO NORMAL. PRAYERS ANSWERED. I DIDN'T WANT TO DSND FOR WARMER AIR BECAUSE I WAS APPROACHING THE ZZZ2 AIRSPACE. FINALLY CONTACTED ZZZ2 APPROACH; RECEIVED CLRNC TO 9000 FT AND PASSED ME ON TO ZZZ1 APPROACH. THEY VECTORED ME TO THE VOR APCH TO ZZZ1. MY CONCERN IS THAT I WAS FLYING A SINGLE ENGINE ACFT IN FOREIGN COUNTRY IN IMC CONDITIONS (AGAINST THEIR RULES). THE FORECASTER REALLY MISSED IT. ACTUALLY IT WAS A CIRCULAR STORM THAT CAME BACK AROUND AGAIN AND AGAIN FOR TWO MORE DAYS. STILL; MY RESPONSIBILITY.

Data retrieved from NASA's ASRS site as of January 2009 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.