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NATIONAL METEOROLOGICAL SERVICE OF BELIZE

FORECAST DISCUSSION

DATE:  SATURDAY 23RD MAY 2015 (EVENING)

SAT IMAGERY AND SFC OBS SHOWED THAT SKIES WERE CLOUDY ACROSS THE COUNTRY THIS AFTERNOON AND EVENING. A FEW SHOWERS AND THUNDERSTORMS AFFECTED MAINLY CNTRL AND N'RN AREAS OF THE COUNTRY AT FIRST AND THEN DECREASED WHILE MOVING FURTHER NORTH LATER IN THE EVENING. WATER VAPOUR IMAGERY INDICATES MOIST CONDITIONS AT MID-UPPER LEVS WHILE LATEST PRECIP WATER ANALYSIS SUGGESTS HIGH AVAILABLE MOISTURE WITH PWAT OF AROUND 60MM NEAR BZE AND THE ENTIRE GULF OF HONDURAS.

SFC ANALYSIS (NHC-18Z) SHOWS THE COUNTRY UNDER AN E'LY SFC FLOW WITH THE ATLC HIGH PRESSURE RIDGE EXTENDING INTO THE E'RN GULF OF MEX. THE FLOW CONTINUED E'LY AT 850MB WHILE AN ESE'LY FLOW PREVAILED AT 700MB. AT THE UPPER LEVS A DIVERGENT SW-WSW'LY FLOW PREVAILED. THE MAIN FEATURE AT UPPER LEVS WAS A TROF OF LOW PRESSURE OVER THE E'RN PACIFIC AND A HIGH PRESSURE WITH AXIS JUST EAST OF BZE. 

THE GFS (12 AND 18Z) RUNS FCST THE SFC FLOW TO CONTINUE E'LY TONIGHT AND THEN BECOME MORE ESE'LY TOMORROW AS THE RIDGE PULLS FURTHER EAST. MOISTURE LEVS WILL REMAIN RELATIVELY HIGH TONIGHT AND THEN DECREASE TOMORROW. BY SUNDAY NIGHT INTO MONDAY MOISTURE WILL BE QUITE LOW WITH LIMITED AMOUNTS CAPPED IN THE LOW LEVS BELOW 800MB. AT THE UPPER LEVS THE FLOW WILL CONTINUE WSW'LY AT LEAST FOR THE NEXT 24 HOURS OR SO. AFTER THAT RIDGING WILL BECOME ESTABLISED TO THE WEST FORCING A MORE CONVERGENT WNW-NW'LY FLOW ALOFT. THE OVERALL SCENARIO SUGGESTS THAT CONDITIONS WILL CONTINUE A BIT MOIST AND UNSTABLE TONIGHT AND THEN IMPROVE TOMORROW. CONDITIONS SHOULD RETURN TO MAINLY FAIR BY SUNDAY NIGHT INTO MONDAY.

THE GFS SHOWS RAINFALL AMOUNTS DECREASING TONIGHT WITH ONLY SMALL AMOUNTS TOMORROW THROUGH TO MONDAY. THE NAM AND THE 5-KM WRF DID NOT HAVE RAINFALL AMOUNTS HIGH TO START WITH AND THEY BOTH SHOW AMOUNTS REMAINING LOW FOR THE NEXT 48 HOURS. THE 15-KM WRF IS A BIT MORE ACCURATE INITIALLY AS IT PICKED UP THE RAINFALL THAT OCCURED TODAY. IT SHOWS AMOUNTS CONTINUING RELATIVELY HIGH OVER S'RN AND COASTAL AREAS TONIGHT AND THEN DECREASING TOMORROW AND BEING CONFINED TO THE SOUTH BY SUNDAY NIGHT.

FORECAST:  CLOUDY AT TIMES TONIGHT WITH A FEW SHOWERS AND ISOLATED THUNDERSTORMS MAINLY ALONG THE COAST AND IN THE SOUTH. PARTLY CLOUDY TOMORROW WITH SHOWERS AND THUNDERSTORMS DECREASING AND BECOMING ISOLATED.

OUTLOOK:  FOR SUNDAY NIGHT AND MONDAY IS FOR A RETURN TO MAINLY FAIR WEATHER WITH ONLY ISOLATED SHOWERS.

MARINE:  WINDS: EAST 10-20 KTS ; SEAS: MODERATE ; WAVES: 4-5 FT

FCSTR:  R. Gordon