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NATIONAL METEOROLOGICAL SERVICE OF BELIZE

FORECAST DISCUSSION

DATE:  FRIDAY 19TH DECEMBER 2014 (AFTERNOON)

SAT IMAGERY (VIZ) SHOWED MOSTLY CLOUDY SKIES THIS MORNING WITH SHOWERS GENERALLY ISOLATED. MOSTLY LAYERED CLOUDS, WITH SOME MODERATE CONVECTION WAS OVER COASTAL WATERS TO JUST EAST OF THE BAY ISLANDS AND FROM NE'RN HONDURAS - E'RN YUCATAN WITH A DISTINCT SWIRL CENTERED EAST OF N'RN BZE. WV IMAGERY DETECTED SOME MOISTURE FROM NE'RN HONDURAS - E'RN YUCATAN WHILE MOSTLY DRY CONDITIONS PREVAILED ACROSS S'RN MEXICO AND THE SE'RN GLF - CENTRAL AMERICA AND MOST OF THE CARIBBEAN. MIMIC-PW LOOP SHOW AVAILABLE MOISTURE HAS INCREASED AND LATEST IMAGE (14Z) SHOW VALUES RANGING 47-57mm.  

SFC ANALYSIS (TPC - 19 / 12Z) SHOWED A WEAK RIDGE ACROSS THE N'RN GLFMEX AND A TROUGH OF LOW PRESSURE FROM NE'RN HONDURAS TO NE'RN YUCATAN. A LIGHT N'LY - NW'LY FLOW PREVAILED OVER OUR AREA. THE SFC RIDGE REFLECTED THROUGH THE 850hPa LVL AND THE FLOW WAS MOSTLY E'LY WHILE AT 700hPa A HIGH WAS CENTERED OVER W'RN CUBA WITH A SE'LY FLOW OVER OUR AREA.... AND CENTERED OVER E'RN YUCATAN WITH A NE'LY FLOW AT 500hPa. ANALYSIS SHOW A DIVERGENT LOW LVL PATTERN OVER OUR BECMG CONVERGENT IN THE VICINITY OF THE SFC TROUGH. AT UPPER LVLS THE FLOW BECMGS W'LY - SW'LY AS A BROAD RIDGE PATTERN EXTENDS ACROSS THE W'RN CARIBBEAN - CENTRAL AMERICA INTO THE SE'RN USA. THE UPPER LVL PATTERN WAS CONVERGENT OVER OUR AREA INCREASING OVER THE YUCATAN CHANNEL AND YUCATAN. 

THE GFS (00Z / 12Z) MODEL RUNS FCST THE SURFACE / LOW LEVEL TROUGH AND ASSOCIATED VORTICITY MAX TO DRIFT NW'WARDS FROM OVER THE NW'RN CARIBBEAN TO OVER N'RN BZE - YUCATAN - GUATEMALA TONIGHT AND TOMORROW. THE WEAK RIDGE OVER THE GULF OF MEXICO IS TO WEAKEN LATER TODAY AS A WEAK FRONTAL LOW MOVESACROSS THE NW'RN GLFMEX. THE FLOW AT THE SFC - LOW - MID LVLS IS TO BECMG SE'LY TONIGHT AND CONTINUE AT THE SFC - LOW LVLS THROUGH THE END OF THE 3-DAY CYCLE WHILE AT MID LVLS THE HIGH IS TO RELOCATE E'WARDS WITH WINDS VEERING TO S'LY BY SUN. THE GFS FCST A WEAKLY CONVERGENT LOW LVL PATTERN DEVELOPING TONIGHT WITH LOW LVL MOISTURE TO SURGE / PEAK THRU MID LVLS AFTER MID-DAY TOMORROW AND REMAIN ELEVATED THRU SAT NIGHT. THE GFS ALSO SUGGEST MOD LIFT THRU THE MID LVLS AROUND MID-DAY TOMORROW. THE RIDGE PATTERN AND SW'LY FLOW AT UPPER LVLS IS TO PERSIST THIS 3-DAY CYCLE. HOWEVER UPPER LVL CONVERGENCE TODAY / TONIGHT IS TO DECREASE BECOMING NEUTRAL - WEAKLY DIVERGENT TOMORROW THRU SUN. IN THIS PATTERN SHOWER ACTIVITY IS EXPECTED TO CONTINUE GENERALLY ISOLATED THROUGH EARLY TOMORROW THEN INCREASE SLIGHTLY TO A FEW MOSTLY OVER N'RN AREAS AS THE SE'LY FLOW DEVELOPS.

THE GFS FCST ONLY TRACE RR AMTS TODAY / TONIGHT AND EARLY TOMORROW THEN INCREASES TO .25-.5ins/6hrs OVER THE NORTH AND INLAND TOMORROW AFTERNOON / EARLY TOMORROW NIGHT BEFORE RETURNING TO TRACE AMTS. THE NAM IS A BIT MORE ACTIVE OVER THE NORTH TODAY WITH ISOL MAX OF .50ins/6hrs BUT MOSTLY .10-.25ins/6hrs THROUGH SUN. THE NVG KEEPS CONDITIONS DRY THE NEXT 3-4 DAYS.  

FORECAST:  MOSTLY CLOUDY SKIES WITH SHOWERS GENERALLY ISOLATED. 

OUTLOOK:  MOSTLY CLOUDY WITH A FEW SHOWERS AND ISOLATED THUNDERSTORMS MAINLY OVER NORTHERN AND INLAND AREAS ON SAT. AFTERNOON AND NIGHT, THEN BECOMING GENERALLY ISOLATED DURING SUN. MORNING. 

MARINE:   WINDS: N-NE 5-15 KTS BECMG SE'LY TONIGHT.; SEAS: LIGHT CHOP - CHOPPY.; WAVES: 2-4 FT.

FCSTR:  M.  GENTLE.