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NATIONAL METEOROLOGICAL SERVICE OF BELIZE

FORECAST DISCUSSION

  

DATE:  THURSDAY 3RD SEPTEMBER 2015 (EVENING)

SHOWERS WERE GENERALLY ISOLATED THIS AFTERNOON, BUT WITH A FEW OVER THE LADYVILLE AREA. SINCE EVENING, SHOWERS HAVE DECREAED TO LITTLE OR NONE, BUT WITH A FEW OVER THE S'RN BORDER AREA AFTER 01Z. SURFACE ANALYSIS FOR 18Z (NHC) SHOWED A 1017MB HIGH OVER THE NE GULF OF MEXICO SUPPORTING A MODERATE EASTERLY AIRFLOW OVER THE NW CARIBBEAN AND YUCATAN PENINSULA. THE MONSOON TROF EXTENDED FROM A 1006MB LOW OVER N'RN COLOMBIA ALONG 10N INTO THE E'RN PACIFIC. A TROPICAL WAVE WAS ALONG 83/84W SOUTH OF 16N AND WAS MOVING WEST AT 10-15KTS. THE HIGH WAS OVER FLORIDA AT LOW LEVELS, AND SUPPORTED AN EAST-SOUTHEAST FLOW AT THOSE LEVELS. AVAILABLE MOISTURE APPEARED MODERATELY HIGH WITH PWAT AROUND 50MM WEST OF 75W, BUT WITH THE LOW LEVEL MOISTURE BEING RELATIVELY LOW. THE HIGH LEVEL PATTERN WAS WEAKLY CONVERGENT OVER THE NORTH AND NEUTRAL OVER THE SOUTH, BUT DIVERGENT OVER HONDURAS AND NICARAGUA. A SMALL UPPER LOW WAS OVER THE GULF OF HONDURAS WITH TROF TO THE CAYMAN ISLANDS THEN TO ANOTHER LOW NEAR PUERTO RICO. 

THE GFS FORECASTS THE SURFACE PATTERN TO REMAIN SIMILAR THROUGH SATURDAY. THE SURFACE AND LOW LEVEL FLOWS ARE TO REMAIN EASTERLY AND EAST-SOUTHEASTERLY RESPECTIVELY. THE GFS DOES NOT RESLOVE THE TROPICAL WAVE WELL AND SHOWS NO SIG VEERING OF LOW LEVEL WINDS TONIGHT OR TOMORROW. THE LOW LEVEL MOISTURE IS TO REMAIN RELATIVELY LOW THROUGH TOMORROW, THEN INCREASE TOMORROW NIGHT, MAINLY OVER THE SOUTH. THE UPPER LOW IS TO MOVE SLOWLY NORTHWESTWARD ACROSS BELIZE DURING TOMORROW, THEN WEAKEN OVER NW YUCATAN EARLY SUNDAY. THE HIGH LEVEL PATTERN IS TO BECOME GENERALLY DIVERGENT TOMORROW NIGHT AND SATURDAY. THIS SUGGESTS THAT SHOWER ACTIVITY WILL CONTINUE ISOLATED TONIGHT AND TOMORROW, THEN INCREASE SLIGHTLY TO MODERATELY OVER THE SOUTH TOMORROW NIGHT AND SATURDAY. 

THE NAM AND NVG GENERALLY AGREE WITH THE GFS THROUGH SATURDAY. THE MODELS ALL GENERALLY GO FOR A SLIGHT INCREASE IN RAINFALL TOMORROW NIGHT AND SATURDAY. (THE GFS HAS BEEN OVER-FORECASTING THE RAINFALL LATELY.) THE GFS SHOWS UP TO 0.50 INS/6HRS OVER THE SOUTH TONIGHT THEN 0.25 INS/6HRS OVER SOME PARTS OF THE MAINLAND TOMORROW, WITH A SIMILAR PATTERN FOR TOMORROW NIGHT AND SATURDAY . THE NAM FORECASTS LIGHT AMOUNTS TONIGHT AND TOMORROW, THEN UP TO 0.25 INS/6HRS MAINLY OVER THE SOTH TOMORROW NIGHT AND SATURDAY. THE NVG GOES FOR LITTLE RAIN TONIGHT AND TOMORROW, THEN A SLIGHT INCREASE TOMORROW NIGHT WITH UP TO 16MM/12HRS OVER THE SOUTH. 

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

OUTLOOK:  CLOUDY AT TIMES WITH A FEW SHOWERS AND THUNDERSTORMS MOSTLY OVER SOUTHERN DISTRICTS.

MARINE:  EAST 10-20KTS; CHOPPY-MODERATE; 3-5FT.

FCSTR:  RUDON