B737 flight crew and dispatcher reported confusion concerning the legalities of a departure with -pl...

Narrative:

Flight pushed at ewr and after push ATIS and metar changed to indicate -pl which would leave an allowance time of :10. Captain called and said no pellets just rain. While talking with captain ATIS and metar amended to delete pellets and show just -RA. Captain questioned whether as an onsite observer he could say no pellets just rain. Called chief and he stated that if company X was not reporting pellets then we were legal to go. Captain concurred and flight took off. Captain ACARS later to say the following:FYI we will do a reportabout the rapl WX at ewr..seems like a lot of.conflicting guidancebetween the fom+ the hot ACARS lwe information..it would be good to see what is the.master WX source..ATIS..eyeballs..or lwe..our weather service reported nothing but rain during the entire event.

Original NASA ASRS Text

Title: B737 flight crew and Dispatcher reported confusion concerning the legalities of a departure with -pl on the ATIS and only RA on the Hold Over Time app.

Narrative: Flight pushed at EWR and after push ATIS and METAR changed to indicate -pl which would leave an allowance time of :10. Captain called and said no pellets just rain. While talking with captain ATIS and METAR amended to delete pellets and show just -RA. Captain questioned whether as an onsite observer he could say no pellets just rain. Called Chief and he stated that if Company X was not reporting pellets then we were legal to go. Captain concurred and flight took off. Captain ACARS later to say the following:FYI WE WILL DO A REPORTABOUT THE RAPL WX AT EWR..SEEMS LIKE A LOT OF.CONFLICTING GUIDANCEBETWEEN THE FOM+ THE HOT ACARS LWE INFO..IT WOULD BE GOOD TO SEE WHAT IS THE.MASTER WX SOURCE..ATIS..EYEBALLS..OR LWE..Our Weather Service reported nothing but rain during the entire event.

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.

Attributes
ACN	1419134
Time
Date	201701
Place
Locale Reference	EWR.Airport
State Reference	NJ
Environment
Flight Conditions	IMC
Aircraft 1
Make Model Name	B737 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	Taxi
Flight Plan	IFR
Person 1
Function	Dispatcher
Person 2
Function	First Officer Pilot Not Flying
Qualification	Flight Crew Air Transport Pilot (ATP)
Experience	Flight Crew Type 13
Events
Anomaly	Deviation - Procedural Published Material / Policy

B737 flight crew and dispatcher reported confusion concerning the legalities of a departure with -pl on the ATIS and only RA on the hold over time app.