Excerpt from the Afternoon AFD from NWS Melbourne,FL. A bit long for a post but very informative.

VIRTUALLY EVERY AVBL MODEL(NAM/GFS/UKM/ECM/CMC/NGP) AND EVEN SOME
OF LESSER KNOWN ONES (JMA/KMA-GDAPS) SHOW A DISCRETE LOW PRES SYSTEM GRADUALLY SPINNING UP ACROSS THE NW CARIBBEAN OVER THE NEXT 2-3 DAYS... THEN TURNING N/NEWD AND MOVING ACROSS FL OR VERY NEARLY SO...WITH THE SAT DAYTIME PD...GIVE OR TAKE A BIT...BEING THE BROAD CONSENSUS ON TIME FRAME FOR POTENTIAL EFFECTS ON SENSIBLE WX.
HOWEVER...EVEN WITH THIS LOOSE CONSENSUS...AND THE FACT THAT THIS IS NOW GETTING INTO THE DAY 3 TO 4 FCST TIME FRAME...CAVEATS STILL ABOUND.

NOTWITHSTANDING THE PREVIOUS MODEL "FALSE ALARMS"...THERE REMAIN SIGNIFICANT DIFFS BETWEEN THE MODELS - ENOUGH SO TO REMAIN WARY OF COMPLETELY BUYING INTO A HIGH POP/QPF EVENT FOR AT LEAST PART OF THE
CWA. FOR INSTANCE...SOME OF THE GUIDANCE (ECM/NGP/GFS) STILL KEEP THE SYSTEM FAR ENOUGH SOUTH/EAST SUCH THAT MUCH OF THE PRECIP MISSES ECFL...ALBEIT NOT BY MUCH. OTHERS (UKM/CMC/JMA...WITH THE H84 NAM
HINTING AS SUCH) BRING THE LOW FAR ENOUGH NORTH ACROSS THE ERN GOMEX TO GIVE THE CTRL PENINSULA HIGH POPS/DECENT QPF.

http://www.srh.noaa.gov/productview.php?pil=AFDMLB&version=1&max=61

(QPF is roughly the quantitative precipitation forecast... the amount of rain that will fall over X amount of time)