ERJ-170 DEPARTING LGA; DEVIATED FROM SID TO AVOID WX. REQUEST FOR DEVIATION WAS DENIED BY ATC; AND FLT CREW RETURNED TO COURSE.

Narrative

THE DAY STARTED AT XA35 AT ZZZ1 ARPT. CLRNC TO LGA WAS RECEIVED INDICATING AN EDCT OF XC49. AFTER DISCUSSING THE CLRNC WITH THE CREW; PAX; AND STATION OPS; IT WAS DECIDED TO TAXI OUT AND WAIT FOR THE DEP TIME. AS WE WERE WAITING; WE WERE NOTIFIED THAT THE EDCT HAD BEEN CANCELED BECAUSE A GND STOP HAD BEEN ISSUED; AND OUR DEP TIME WAS INDEFINITE. AT APPROX XC15 WE WERE NOTIFIED THAT THE GND STOP HAD BEEN LIFTED; AND WE HAD A NEW EDCT OF XD43. WE DISCUSSED THIS BTWN OURSELVES; DISPATCH; AND OPS; AND DECIDED TO TAXI BACK TO THE GATE TO TAKE ON ADDITIONAL FUEL; AS WE HAD USED ALMOST ALL OUR ALLOTTED HOLDING FUEL WAITING TO DEPART. AFTER WE FUELED; WE WERE NOTIFIED THAT OUR TIME HAD BEEN MOVED UP TO XD36 AND WE DEPARTED AT THAT TIME FOR LGA. THE FIRST HR OF THE FLT WAS UNEVENTFUL. AS WE APCHED ETK; THERE WERE MULTIPLE LINES OF STRONG STORMS THAT WE HAD TO CROSS TO GET INTO LGA. WE LANDED SAFELY IN LGA AT XF20. AFTER DEPLANING THE ARRIVING PAX; WE CONTACTED DISPATCH AND DISCUSSED THE WX AND ROUTING BACK TO ZZZ1. IT WAS DECIDED TO HOLD OFF BOARDING BECAUSE ALL W DEP GATES WERE CLOSED; AND THE MINIMUM WAIT TIME FOR DEP WBOUND WAS 3 HRS. AT APPROX XG45 WE AGAIN DISCUSSED THE SIT WITH DISPATCH AND OPS; AND DECIDED TO BOARD UP AND TAXI OUT. MANY FLTS HAD CANCELED; AND GATE SPACE WAS NEEDED. WE CLOSED THE DOOR AND BLOCKED OUT AT XH16. OUR ORIGINALLY CLRED RTE WAS LGA 1 SID WHITESTONE CLB GAYEL. APPROX XH50 WE RECEIVED A NEW CLRNC THAT GAVE US THE RTE LGA 1 SID MASPETH CLB ELIOT. WE RECEIVED CLRNC TO START UP THE ENGS AND TAXI AROUND XI10. JUST AFTER STARTING THE #1 ENG; GND INFORMED US THAT THE PREVIOUS DEPS OVER ELIOT HAD REFUSED THE RTE ONCE AIRBORNE; AND THAT WE MIGHT GET ANOTHER RERTE. WE DID NOT; HOWEVER; RECEIVE ONE PRIOR TO BE HANDED OVER TO THE TWR CTLR. WE QUERIED TWR AND WERE TOLD THAT THE LAST COUPLE ACFT THAT HAD DEPARTED OVER ELIOT WERE GETTING OUT WITHOUT PROBS; AND WITH ONLY MINOR DEVS. WE TOOK THE RWY AND DEPARTED AT XI29. THE MASPETH CLB OFF OF RWY 13 IS AN IMMEDIATE R TURN TO A HDG OF 180 DEGS; THEN ANOTHER R TURN AT 4.1 DME OFF OF LGA TO A HDG OF 340 DEGS. AS WE COMPLETED THE R TURN TO 180 DEGS; WE SAW MULTIPLE STRONG TO SEVERE STORMS ON THE RADAR DISPLAY. THEY WERE SHOWING YELLOW; RED; AND PURPLE ON THE SCREEN AT BOTH THE 5 AND 12.5 MI RANGE. THE CAPT REQUESTED A L TURN TO AVOID THE WORST OF THE CELLS; WHICH THE FO IMMEDIATELY ASKED DEP FOR. DURING THIS REQUEST THE CAPT BANKED THE ACFT SLIGHTLY L TO AVOID A CELL. NEW YORK DEP STRONGLY REFUSED THE REQUEST FOR THE DEV; SAYING THAT WE WOULD HAVE STRAYED INTO THE ARR PATH FOR JFK. UPON HEARING THIS; THE CAPT IMMEDIATELY TURNED THE ACFT R TO FOLLOW THE SID AND TO TRY TO AVOID THE LARGE CELL DIRECTLY AHEAD OF OUR FLT PATH. WHEN THE FO RPTED TO THE CTLR THAT WE WERE TURNING R; THE CTLR STATED; 'IF YOU CANNOT COMPLY WITH THE SID; DON'T DEPART.' THE FO INFORMED HIM THAT THERE WAS NO WAY TO SEE THE WX FROM THE GND; AND THAT WE WERE COMPLYING WITH THE SID AT THAT TIME. THE CTLR THEN GAVE US UPDATED WX INFO; WHICH WAS THE FIRST TIME THAT ANY NEW WX INFO WAS MADE AVAILABLE TO US SINCE WE TOOK THE RWY IN LGA. TOTAL DEV TO THE L OF COURSE WAS LESS THAN 1/2 MI; AND FOR LESS THAN 10 SECONDS. WE CONTINUED TO CLB ON THE SID AND ATC INSTRUCTIONS; ENCOUNTERING HVY RAIN; MODERATE TURB; AND FREQUENT LIGHTNING. JFK WAS UTILIZING RWY 22L AT THE TIME FOR ARRS; WHICH WAS THE FURTHEST APCH CORRIDOR FROM LGA. NO FURTHER COMMENTS WERE RECEIVED FROM ANY CTLRS.