RWY INCURSION BY A B737 DURING TAXI OP IN A TSTM AT MSY; LA.

Narrative

WE WERE WAITING FOR A TSTM WITH LIGHTNING TO PASS OVER THE ARPT IN NEW ORLEANS. AFTER WAITING 10 MINS OR SO; SOME OF THE LIGHTNING STOPPED AND WE PUSHED OUT OF GATE. AFTER THE ENGS WERE STARTED; WE CALLED GND FOR A TAXI CLRNC AND WERE INSTRUCTED TO TAXI TO RWY 10. I LOOKED DOWN AT THE TAXI CHART AND NOTED THAT THE RAMP AREA LED TO TXWY E AND TO RWY 10. THERE WAS VERY HVY RAIN AND THE VISIBILITY WAS POOR. AS WE STARTED TAXIING OUT; I CALLED FOR THE TAXI CHKLIST. MY EYES WERE INSIDE THE COCKPIT; CHKING THE SPD BOOK THINKING I WAS TAXIING TO TXWY E. INSTEAD; I WAS TAXIING TOWARD TXWY F AND TOWARD RWY 10. OUR NOSE WAS PAST THE HOLD LINE ON TXWY F; WHEN THE GND CTLR SAID 'IT APPEARS YOU ARE TAXIING ONTO RWY 10. TAXI ONTO RWY 10; THEN MAKE A L TURN ONTO TXWY E.' I TURNED ON THE WIPERS AND REALIZED THAT WE HAD ALMOST TAXIED ONTO RWY 10 (ACTIVE RWY). WE TAXIED TO RWY 10 IN HVY RAIN. WE WERE CLRED TO TKOF; MADE A L TURN AWAY FROM THE HVY CELLS. NORMAL FLT. SUPPLEMENTAL INFO FROM ACN 616315: WE WERE PUSHED DEEP INTO TXWY E (RAMP AT THIS POINT) TO NEAR INTXN WITH TXWY F. WIND SHIFT REQUIRED USE OF RWY 10. I WENT 'HEAD DOWN' TO LOOK AT RADAR TO EVALUATE WX TO THE E THROUGH W AS WE TURNED. JUST AS I LOOKED UP TO CHK STATUS OF TURN AND POS ON RAMP; I REALIZED THAT WE WERE ENTERING TXWY F AND ABOUT TO PROCEED ONTO RWY 10/28. AT THE SAME TIME; GND CTL NOTICED AND COMMANDED A STOP (NOSE OF ACFT JUST OVER STOP BARS). ACFT POS RELATIVE TO TXWY F AND TXWY E WAS A WIDE AREA OF PAVEMENT WITH 'SOFT' DIAGONALS THAT LED TO AN EARLY STOP OF TURN. TAXI RTE WAS BRIEFED FOR RWY 28 WITH LAST MIN CHANGE THAT THOUGH DISCUSSED EARLIER AS A POSSIBILITY; DIDN'T TAKE INTO ACCOUNT THE DEEP PUSH AND PROX TO TXWY F. CLRLY; THE ONGOING WX ISSUES CAUSED THE DISTRS THAT LED TO THE RWY INCURSION.