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NATIONAL METEOROLOGICAL SERVICE OF BELIZE

FORECAST DISCUSSION  

DATE:  MONDAY 22ND MAY 2017 (AFTERNOON)

SAT IMAGERY (VIZ) AND RADAR OBS SHOWED CLOUDY SPELLS AND A FEW SHOWERS AFFECTED THE CENTRAL AREAS OF THE COUNTRY THIS MORNING AND CONTINUE AT MID-DAY. LATEST MIMIC-PW IMAGE (16Z) SHOW MOD AMTS OF AVAILABLE MOISTURE IN THE RANGE OF 40-50mm ALONG CENTRAL - N'RN BZE WITH SMALLER VALUES TO THE SOUTH. WV IMAGERY DETECTED MOSTLY DRY CONDITIONS ALOFT ACROSS MOST OF MEXICO - N'RN CENTRAL AMERICA AND THE NW'RN CARIBBEAN. SKEW-T (12Z) SOUNDING SHOWED SOME LOW LVL MOISTURE BELOW 800hPa THEN BECMG DRIER WITH PW 48.68mm. THE INDICES (KI 21.30, SHOW 0.35, LIFTED -3.67 AND CAPE 1841j/kg) SHOW SOME RESIDUAL INSTABILITY. 

 

SFC ANALYSIS (HPC - 22 / 12Z) SHOWED HIGH PRESSURES DOMINATING THE NW'RN ATLANTIC - SE'RN AND S'RN USA AND CENTRAL MEXICO. A TROPICAL WAVE WAS ALONG 70W SOUTH OF 18N. THE PATTERN SUPPORTED A MOD AND AT TIMES GUSTY E'LY FLOW EARLIER THIS MORNING. WINDS HAVE SUBSIDED SINCE. THE RIDGE PATTERN THRU THE LOW LVLS SUPPORTED AN ESE'LY FLOW AT 850-700hPa, WHILE AT MID LVLS A CELL OF THE RIDGE TO THE WEST SUPPORTED A NE'LY FLOW. AT UPPER LVLS THE FLOW BECMGS NW'LY AND CONVERGENT BOUNDED BY BROAD TROUGHING TO THE EAST AND RIDGE FROM THE E'RN PACIFIC INTO MAINLAND MEXICO.  

 

THE GFS FCST THE SFC - LOW LVL RIDGE PATTERN TO CONTINUE DOMINATING THIS CYCLE WHILE WEAKENING AS THE HIGH DRIFTS AWAY TO THE EAST. A COLD FRONT IS TO APPROACH NW'RN YUCATAN BY THE END OF THE 3-DAY CYCLE, WHILE THE TROPICAL WAVE IS TO TRACK SLOWLY TO ALONG 80W DURING THIS TIME FRAME. THE FLOW IS TO BECMG MORE ESE'LY TONIGHT AND THE FOLL COUPLE OF DAYS. IN A DIURNALLY CONVERENT PATTERN THE MOISTURE IS TO DECREASE / SUBSIDE TONIGHT AND CONTINUE RELATIVELY LOW THRU THE END OF THE CYCLE. AT UPPER LVLS THE CONVERGENT N'LY - NW'LY FLOW IS TO CONTINUE THRU TOMORROW RTHEN WINDS BECMG W'LY - SW'LY AND WEAKLY DIVERGENT BY THE END OF THE CYCLE AS THE HIGH / RIDGE CROSSES OVER FROM THE E'RN PACIFIC TO THE SW'RN CARIBBEAN. THE MODELS (GFS / WRF DOM1 AND NAM) GENERALLY AGREE WITH LOW RR AMTS DURING THE NEXT 24-30 HOURS THEN DECREASING.  

FORECAST:  SUNNY WITH SOME CLOUDY SPELLS DURING THE DAYTIME AND PARTLY CLOUDY TONIGHT. SHOWERS WILL BE ISOLATED WITH A FEW MORE INLAND THIS AFTERNOON. 

OUTLOOK:  FOR TUES. AFTERNOON THROUGH TO MIDDAY WED. IS FOR MAINLY FAIR AND WARM CONDITIONS WITH ONLY ISOLATED SHOWERS.

MARINE:  WINDS: EAST 10-20 KT.; SEAS: MODERATE.; WAVES: 4-6 FT.; SMALL CRAFT CAUTION DISCONTINUED.

FCSTR:  M.  GENTLE.