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NATIONAL METEOROLOGICAL SERVICE OF BELIZE

FORECAST DISCUSSION

  

DATE: TUESDAY 28 JULY 2015 (EVENING)

SAT IMAGERY (VIZ) AND RADAR OBS SHOWED SOME CLOUDY SPELLS AND A FEW SHOWERS AFFECTED INLAND AREAS OF THE COUNTRY THIS AFTERNOON.... THEN DRIFTED ACROSS THE W'RN BORDER DURING THE EVENING HOURS. WV IMAGERY LOOP SHOWED MOIST CONDITIONS ACROSS CENTRAL AMERICA - S'RN MEXICO / YUCATAN AND MOST OF THE GLF. HOWEVER, LATEST MIMIC-PW IMAGE (22Z) SHOWED A DECREASE IN AVAILABLE MOISTURE WITH VALUES IN THE RANGE OF 37-47mm OVER COASTAL WATERS.

SFC ANALYSIS (TPC - 28 / 18Z) HAD A TROPICAL WAVE OVER COASTAL BZE - YUCATAN ALONG 88W / 89W.... ANOTHER ALONG 73W / 75W AND A THIRD ALONG 53W. A RIDGE EXTENDED ACROSS THE N'RN GLFMEX WITH A HIGH (1018hPa) BETWEEN SOUTH FLORIDA AND W'RN CUBA. THE RIDGE PATTERN SUPPORTS A MOD E'LY FLOW OVER OUR AREA. THE RIDGE PATTERN ACROSS THE GLFMEX ALSO DOMINATES AT LOW LVLS (850-700hPa) WITH THE RIDGE EXTENDING ACROSS YUCATAN AT MID LVLS. THE FLOW BACKED SLIGHTLY FROM ESE'LY AT LOW LVLS TO ENE'LY AT MID LVLS. AT UPPER LVLS THE FLOW WAS N'LY - NW'LY AS A RIDGE DOMINATED ACROSS THE GLFMEX AND TROUGH AXIS ACROSS YUCATAN FROM A LOW OVER CENTRAL - W'RN CUBA. THE UPPER LVL PATTERN WAS NEUTRAL - WEAKLY CONVERGENT.     

 

THE GFS FCST THE RIDGE PATTERN TO PERSIST AT SFC - LOW LVLS DURING THE NEXT 2-3 DAYS. THE NEXT APPROACHING TROPICAL WAVE IS EXPECTED OVER OUR AREA LATE TOMORROW NIGHT INTO EARLY THURS. THE GFS FCST E'LY - ENE'LY SFC WINDS THIS 3-DAY CYCLE. HOWEVER SLIGHT VEERING / WAVING IS FCST AT LOW LVLS (850-700hPa) BY TOMORROW EVENING AS AN E'LY FLOW SWINGS TO ESE'LY AFTER MID-CYCLE. THE GFS SUGGEST A MIN IN LOW LVL MOISTURE OVER-NIGHT TONIGHT AND A MAX TOMORROW NIGHT BEFORE ANOTHER DRY 850-450hPa LAYER DEVELOPS BY MID-DAY THURS. THE GFS ALSO FCST A SURGE IN LOW LVL CONVERGECE LATER TOMORROW THEN BECMG WEAKER AFTER. AT UPPER LVLS THE TUTT IS TO DROP SOUTH ACROSS YUCATAN - BZE WITH A WEAK LOW TO DEVELOP OVER BZE TOMORROW NIGHT THROUGH THURS. NIGHT. THE N'LY COMPONENT TO THE UPPER LVL FLOW IS TO SWING TO S'LY AFTER MID-CYCLE AND THE WEAKLY CONVERGENT PATTERN IS TO BECMG WEAKLY DIVERGENT TOMORROW NIGHT. THE SYNOPTIC PATTERN SUGGEST MINIMAL SHOWER ACTIVITY TONIGHT AND TOMORROW WITH A SLIGHT INCREASE OVER THE SOUTH AND ALONG THE COAST TOMORROW NIGHT / EARLY THURS ASSOCIATED WITH THE TROPICAL WAVE.

THE MODELS GENERALLY AGREE WITH ONLY LIGHT RR AMTS DURING TH EFCST PERIOD THEN AN INCREASE DURING THE EARLY EXTND WITH THE GFS GOING FOR .75ins/6hrs AND THE NAM TO A LESSER EXTEND WITH .25ins/6hrs. THE NVG GOES FOR 8-12mm/12hrs WED NIGHT AND THURS.      

FORECAST:   PARTLY CLOUDY TONIGHT AND SUNNY WITH A FEW CLOUDY SPELLS TOMORROW. SHOWERS OR THUNDERSTORMS WILL BE ISOLATED. 

OUTLOOK:   SOME CLOUDY SPELLS WITH A FEW SHOWERS AND ISOLATED THUNDERSTORMS MAINLY OVER THE SOUTH AND ALONG THE COAST WED. NIGHT THEN BECOMING GENERALLY ISOLATED THURS. 

MARINE:  WINDS: EAST 10-20 KT; SEAS: CHOPPY - MODERATE.; WAVES: 3-6 FT. 

FORECASTER:     M.  GENTLE.