Define Flight Briefing?
What country are you getting it in?
If in the UK - where are you getting it from?
In the UK.
Yes, you can talk to a weather forecaster for a 1 to 1 briefing. It'll be a premium rate phone call or a "and your credit card is before I start talking sir?" affair. Alternatively you can dial the "Airmet" service from the Met Office and get a forecast for a specified area for a specified time period. These briefings will contain weather
only (Freezing level, upper winds, cloud cover with forecast base and tops, meteorological events and the outlook).
Alternatively most people either go to the
Met Office website or the (IMHO) superior
Avbrief site. Avbrief also has the advantage, as a subscriber, of providing NOTAMs as well. If you don't have access to them here you can get them from the
AIS site .
In the USA
Dial 1-800-WXBRIEF (Free phone call) - get put through to a personal briefer who'll give you weather, recommendations as to whether the route is VFR or not, will give you NOTAMs relevant to your journey, and then take and file your flight plan for you.
Anywhere else - don't know - I use AVBRIEF from my laptop when in Europe.