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NATIONAL METEOROLOGICAL SERVICE OF BELIZE

FORECAST DISCUSSION

DATE:  FRIDAY 19TH DECEMBER 2014 (EVENING)

SAT IMAGERY SUGGESTS THAT SKIES CONTINUED MOSTLY CLOUDY ESPECIALLY OVER THE NOTHERN HALF OF THE COUNTRY THIS AFTERNOON AND EVENING. LIGHT RAIN WAS OBSERVED AT THE AIPORT DURING THE EARLY PARTS OF THE AFTERNOON. SFC OBS FROM ACROSS THE COUNTRY SUGGEST THAT RAINFALL ACCUMULATED TO ONLY TRACE AMOUNTS AT MOST. WATER VAPOUR IMAGERY SHOW CONDITIONS RELATIVELY DRY ALOFT OVER BZE WHILE A PATCH OF MOISTURE IS OVER THE NW CARIBBEAN SEA. LATEST PRECIP WATER ANALYSIS (21Z) SHOW PWAT OF AROUND 47-50MM NEAR BZE AND HIGHER VALUES FURTHER EAST OVER THE NW CARIBBEAN.

SFC ANALYSIS (NHC-18Z) SHOW A TROF OF LOW PRESSURE WITH AN EMBEDDED LOW PRESSURE CENTER JUST EAST OF THE COUNTRY. THIS FEATURE SUPPORTED A N-NW'LY FLOW OVER THE COUNTRY FOR MOST OF THE DAY. THE FLOW WAS ESE'LY AT 850MB AND SE'LY AT 700MB. AT THE UPPER LEVS A BROAD RIDGE OF HIGH PRESSURE BUILDS N-NE'WARD FROM FROM THE SOUTH WITH AXIS JUST EAST OF BZE. THIS SUPPORTS A WEAKLY CONVERGENT WSW-SW'LY FLOW ALOFT.

THE GFS (12 AND 18Z) MODEL RUNS FCST THE SFC TROF/LOW TO MOVE NW'WARD AND CROSS THE COUNTRY OVERNIGHT. THIS WILL CAUSE SFC WINDS TO VEER TO THE E-SE TONIGHT AND REMAIN THAT WAY FOR THE NEXT 2-3 DAYS. A  MOISTURE SURGE IS FCST ACROSS THE COUNTRY BEHIND THIS SYSTEM WITH MOISTURE PEAKING AROUND MIDDAY TOMORROW THROUGH TO SUNDAY MORNING AND DECREASING THEREAFTER. AT THE UPPER LEVS THE PATTERN WILL NOT BE VERY CONDUCIVE FOR ORGANIZED DEEP CONVECTION WITH THIS SYSTEM. THE RIDGE AXIS TO THE EAST COUPLED WITH BROAD TROFING WEST OF THE AREA WILL CONTINUE TO SUPPORT THE WSW'LY FLOW. THE PATTERN WILL BECOME MORE CONVERGENT (ESPECIALLY AT 300MB) TONIGHT AND THEN WEAKLY DIVERGENT TOMORROW. 

THE OVERALL SCENARIO FAVOURS A  MODEST INCREASE IN SHOWERS LATE TOMORROW THROUGH TO SUNDAY MORNING AND THEN DECREASING AFTER. THE GFS FCST MINIMAL RAINFALL AMOUNTS TONIGHT WITH AMOUNTS INCREASING TOWARD MIDDAY TOMORROW AND PEAKING AT 0.5 INS/6HRS MAINLY IN THE NORTH. AMOUNTS GRADUALLY DECREASE SATURDAY NIGHT INTO SUNDAY. THE NAM DOES NOT FCST A SIG INCREASE IN RAINFALL WITH THE PASSAGE OF THE SFC TROF.

FORECAST:  MOSTLY CLOUDY TONIGHT WITH ISOLATED SHOWERS OR OCCASIONAL LIGHT RAIN MAINLY IN THE NORTH AND ALONG THE COAST. CLOUDY AT TIMES TOMORROW WITH A FEW SHOWERS MOSTLY IN THE AFTERNOON AND MAINLY IN THE NORTH.

OUTLOOK:  SHOWERS WILL DECREASE ON SATURDAY NIGHT AND BECOME GENERALLY ISOLATED BY SUNDAY. 

MARINE:   WINDS: E-SE 5-15 KTS.; SEAS: CHOPPY.; WAVES: 3-4 FT.

FCSTR:  R. Gordon