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NATIONAL METEOROLOGICAL SERVICE OF BELIZE

FORECAST DISCUSSION

DATE: WEDNESDAY 20TH AUGUST 2014 (EVENING)  

SAT IMAGERY (VIZ) AND RADAR OBS SHOWED MOSTLY SHALLOW LOW CLOUDS PREVAILED ACROSS THE COUNTRY THIS AFTERNOON AND EVENING WITH ONLY ISOLATED SHOWERS DEVELOPING. WV IMAGERY SHOWED MOIST CONDITIONS OVER E'RN MEXICO AND THE W'RN GLF WITH SOME ADDITIONAL MOISTURE SPILLING EAST AND SOUTHEAST ACROSS S'RN MEXICO - GUATEMALA AND S'RN REGIONS OF CENTRAL AMERICA. LATEST MIMIC-PW IMAGE SHOW AVAILABLE MOISTURE IN THE RANGE 40-50mm OVER COASTAL WATERS DECREASING NORTH OF A LINE FROM SE'RN YUCATAN - NE'RN HONDURAS.

 

SFC ANALYSIS (TPC - 20 / 18Z) HAD A RIDGE ALONG 26N / 30N INTO THE W'RN GLFMEX WITH A HIGH (1020hPa) OVER THE NE'RN GLFMEX SUPPORTING A MOD E'LY FLOW OVER OUR AREA.  A TROPICAL WAVE WAS ANALYZED ALONG 52W / 53W WITH A LOW (1009hPa) ALONG THE AXIS NEAR 11N. THE STRONG RIDGE PATTERN DOMINATED THROUGH THE LOW-MID LVLS (850-500hPa) WITH A FRESH ESE'LY FLOW. AT UPPER LVLS (300-200hPa) AN UPPER RIDGE WAS CENTERED OVER S'RN MEXICO AND GUATEMALA AND A TROUGH EXTENDED NW'WARDS TO NEAR N'RN BELIZE / SE'RN YUCATAN FROM THE CARIBBEAN. THE UPPER LVL FLOW WAS N'LY - NW'LY AND THE PATTERN WAS WEAKLY CONVERGENT OVER SE'RN MEXICO / YUCATAN AND N'RN CENTRAL AMERICA. 

THE GFS (12Z / 18Z) MODEL RUNS FCST THE SFC - LOW - MID LVLS RIDGE OVER THE GLFMEX TO PERSIST TONIGHT, THEN WEAKEN TOMORROW. THE MOD AND AT TIMES GUSTY FLOW TONIGHT IS TO SUBSIDE SOMEWHAT TOMORROW THROUGH THE END OF THE CYCLE. THE GFS SHOWS THAT THE E'LY SFC FLOW TONIGHT / TOMORROW IS TO BECMG MORE ENE'LY THE FOLL TWO DAYS WHILE AT LOW LVLS THE ESE'LY FLOW IS TO ALSO BACK TO BECMG MORE E'LY TOMORROW THROUGH FRI. THE GFS FCST A WEAKLY CONVERGENT PATTERN THIS CYCLE WITH LOW LVL MOISTURE TO LIMIT / CONFINE BELOW 800hPa. AN UPPER LOW IS TO DEVELOP ALONG THE TROUGH AXIS NEAR JAMAICA AND DRIFT SW'WARDS TO OVER HONDURAS THROUGH FRIDAY. AS A RESULT THE WEAKLY CONVERGENT UPPER LVL PATTERN IS TO PERSIST THROUGH TOMORROW NIGHT, THEN BECMG  A BIT DIVERGENT DURING FRI DUE TO THE PROXIMITY OF THE UPPER LVL LOW. EXCEPT FOR THE CHANCE OF A FEW SHOWERS / ISOLATED THUNDERSTORMS OVER THE SOUTH TONIGHT, LARGELY DUE TO LOCAL EFFECTS.... SHOWER ACTIVITY IS EXPECTED TO CONTINUE GENERALLY ISOLATED. BACKING LOW LVL WINDS AND ADDITIONAL UPPER LVL DIVERGENCE WILL LIKELY SUPPORT A BIT MORE SHOWERS OVER-NIGHT INTO FRI.  

THE MODELS (GFS / NAM /NVG) GENERALLY AGREE AND FCST MOSTLY .10-.25ins/6hrs DURING THE CYCLE BUT WITH LOCALIZED AMTS OF .50ins/6hrs BY THE GFS DURING THE LATE NIGHT / EARLY MORNING..  

FORECAST:  PARTLY CLOUDY TONIGHT AND MOSTLY SUNNY TOMORROW. SHOWERS OR THUNDERSTORMS WILL BE ISOLATED, EXCEPT FOR A FEW MORE OVER THE SOUTH TONIGHT.

EXTENDED:   FOR THURS. NIGHT AND FRI. IS FOR SOME CLOUDY SPELLS WITH A FEW SHOWERS OR ISOLATED THUNDERSTORMS MAINLY OVER THE SOUTH AND COAST.

MARINE:  WINDS: EAST 10-20 KTS. WITH OCCNL HIGHER GUSTS.; SEAS:  MODERATE-ROUGH.; WAVES:  4-7 FT.; SMALL CRAFT CAUTION. 

FCSTR:  M.  GENTLE.