Dispatcher reports on events and actions when weather goes down for one of his flights arriving SAN.

Narrative

TAF for time of Arival: FM0300 30012KT P6SM FEW005 FM1000 29006KT P6SM BKN007 - Metar at time of dept: SAN 19003KT 10SM FEW005 22/19 A2986 Forecast was right on. I planned this flt to arrive SAN with 6000lbs fuel remaining. Checked METAR as flight was approaching SAN: XA51z 18006KT 10SM FEW001 20/18 (looks good). I get an ACARS from this flt that reads; 'MIGHT HAVE 2 DIVERT DUE 2 WX WHERE DO U WANT US 2 GO.' At this point it had only been 21min since I had last checked the METAR and had received no WX alert from the WX vendor we are trying out. So I check the METAR again: XB09Z 19003KT 1SM BR BKN001 18/18 A2987 (this was 18min later). At this time I pulled up all flights heading into SAN via flight explorer to see they are changing runways to land RWY 09. The mins for RWY 09 are 1 mile vis and 336 ceiling. Other aircraft were going missed and I checked FOB which was 6400lbs at which time I advised flight to 'plz proceed to LAX ASAP' as it was a 2500lbs burn (to the Capt's credit he was; I believe below 10000ft; and the ACARS message may not have been received). I then advised the ops manager that it appeared the crew was continuing the approach and if they didn't make it in they would most likely not have the fuel to make it to LAX and SNA would be the divert airport (and at a very min fuel if not emergency). At this point I was told by the ops manager that SNA was not an option. I told him we have no choice due to the unforecast conditions and lack of fuel. I was again told that SNA was not an option and not to send the aircraft there. At this point I told him that's were we were going and that was that. As luck would have it we made it on the ground in SAN at XB27Z with 5600lbs on board. We were the last aircraft to make it in as the METAR 2 min later was: SAN XB30Z 19004KT 1/2SM FG BKN001 OVC002 18/18 A2988. We wouldn't have even been able to initiate an approach. Issues here: Due to sudden and unforecast WX unable to communicate with pilots in a timely manner. Wx Vendor not providing wx alerts in a timely manor. An operations manager that was more concerned with the impact of the operations rather than the safety of the aircraft and put undue pressure on a dispatcher to do something to put the flight into further danger.