Date: 201911
Local time of day: 1201-1800
Location: ZZZ.TRACON, US
Flight conditions: Mixed
Weather elements / visibility: Rain; Thunderstorm; Turbulence
Light: Dusk
Aircraft: B737-800
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Climb
Airspace: Class E ZZZ
ATC / advisory: TRACON ZZZ
Aircraft component: Weather Radar
Component problem: Malfunctioning
Reporter organization: Air Carrier
Reporter function: First Officer; Pilot Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Multiengine
Human factors: Communication Breakdown; Situational Awareness
Anomaly: Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy; Flight Deck / Cabin / Aircraft Event Smoke / Fire / Fumes / Odor; Ground Event / Encounter Other / Unknown; Inflight Event / Encounter Weather / Turbulence
Detector: Person Flight Crew
When detected: Aircraft In Service At Gate; In-flight; Pre-flight
Result: Flight Crew Landed in Emergency Condition; Flight Crew Returned To Departure Airport; General Flight Cancelled / Delayed; General Maintenance Action
Contributing factors: Aircraft; Human Factors; Procedure; Weather
Primary problem: Procedure

Narrative: We arrived at the aircraft for our flight to find the ramp closed due to heavy rain and lightning at the field. After a few minutes the lightning moved off the field and the ramp re-opened; but it was still raining. I went to the aircraft and found the Main Cabin door and cockpit door were left open during the heavy rain; resulting in water in the cockpit. When the Captain arrived we discussed and decided to have Ops bring us some absorbent pads to clean it up. With the cockpit floor now dry again we performed a normal preflight and departed uneventfully. Upon passing about 15;000 feet MSL we turned on the radar because of storms up ahead. The radar then failed in all positions (Manual and Auto; both sides). We discussed between ourselves and decided that continuing onto the oceanic tracks at night without radar; with storms in the area to be a bad idea. We had decided we would probably return to ZZZ; but would discuss with Dispatch prior to commencing the return. The Captain then attempted to make a call to Dispatch on SATCOM 2; only to have it fail as well. At that point we theorized that the water we found in the flight deck upon arriving at the aircraft might have leaked down into the floor and to the [Company] bay; causing shorts. The Captain was eventually able to get through to Dispatch on SATCOM 1; and all this information was relayed. After about a 15 minute call with Dispatch and Maintenance Control; it was decided to return to ZZZ. We started the diversion and ATC was notified. When we started the descent; the aft FAs (flight attendants) called to tell us that they smelled 'something burning' in the aft galley; but could not locate it. At that point the Captain took the aircraft and requested priority handling. I took the QRH and ran the Smoke or Fumes in the Cabin QRH Checklist. We had enough time and were able to complete the entire QRH and all the required items before landing; pertinent to the diversion. About 10 minutes after the initial call the FAs called us to tell us that the smell had dissipated and they were never able to locate the source. We landed on Runway 8R and stopped on the runway to have airport rescue and firefighting in ZZZ confirm that they didn't see anything on the outside of the aircraft. After a successful inspection from airport rescue and firefighting we taxied to the gate and deplaned the Passengers.




Synopsis: B737-800 flight crew reported water in the flight deck due to L1 door and flight deck door being left open during a severe rain squall.