737 flight crew reported entering restricted airspace due to severe weather deviation.

Attributes
ACN	1585470
Time
Date	201810
Local Time Of Day	1801-2400
Place
Locale Reference	ZZZ.ARTCC
State Reference	US
Environment
Light	Night
Aircraft 1
Make Model Name	B737 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	Descent
Route In Use	Vectors
Flight Plan	IFR
Person 1
Function	Enroute Pilot Flying First Officer
Qualification	Flight Crew Air Transport Pilot (ATP) Flight Crew Instrument Flight Crew Multiengine
Person 2
Function	Approach Pilot Not Flying Captain
Qualification	Flight Crew Instrument Flight Crew Multiengine Flight Crew Air Transport Pilot (ATP)
Experience	Flight Crew Last 90 Days 397
Events
Anomaly	Airspace Violation All Types Deviation - Procedural Published Material / Policy Deviation - Procedural FAR Inflight Event / Encounter Weather / Turbulence

Narrative:

We were on descent into ZZZ when dispatch ACARS messaged us an alternate airport with no other explanation. This got us questioning why. As we got closer to the airport; we could see that the weather returns showed a massive thunderstorm approaching ZZZ. We were trying to coordinate a route around the weather as well as manage our fuel and expectations of route delays if we were to go to alternate. As we were getting vectored; it became clear that we were not going to get to the airport with enough fuel to be able to make it to alternate if needed. There was no alternate on the release to begin the flight and not a lot of extra fuel. After we asked to divert to alternate; ATC kept giving us vectors either directly into the weather or away from our alternate. ATC kept issuing us vectors directly into very strong weather. When we told ATC that we could not accept those vectors; they said we have to because of a warning area. We told them we had to go into the warning area as we had no choice at that point due to fuel.as we were trying to get around weather; we made the decision to land at ZZZ1 as that was the closest airport that had good enough weather to get into. We did not think that we would ever make it to our alternate as that was back through the weather and was also experiencing thunderstorms.

Original NASA ASRS Text

Title: 737 flight crew reported entering restricted airspace due to severe weather deviation.

Narrative: We were on descent into ZZZ when Dispatch ACARS messaged us an alternate airport with no other explanation. This got us questioning why. As we got closer to the airport; we could see that the weather returns showed a massive thunderstorm approaching ZZZ. We were trying to coordinate a route around the weather as well as manage our fuel and expectations of route delays if we were to go to alternate. As we were getting vectored; it became clear that we were not going to get to the airport with enough fuel to be able to make it to alternate if needed. There was no alternate on the Release to begin the flight and not a lot of extra fuel. After we asked to divert to alternate; ATC kept giving us vectors either directly into the weather or away from our alternate. ATC kept issuing us vectors directly into very strong weather. When we told ATC that we could not accept those vectors; they said we have to because of a Warning Area. We told them we had to go into the Warning Area as we had no choice at that point due to fuel.As we were trying to get around weather; we made the decision to land at ZZZ1 as that was the closest airport that had good enough weather to get into. We did not think that we would ever make it to our alternate as that was back through the weather and was also experiencing thunderstorms.

Data retrieved from NASA's ASRS site 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.