|Monthly Weather Summary|
Monthly Weather Summary
NATIONAL METEOROLOGICAL SERVICE OF BELIZE
The month of October saw below average rainfall for most stations as rainfall from tropical waves were limited. Weather conditions were affected by persistent low surface pressures over the southwestern and western Caribbean Sea and transient upper level Tutt lows.
A few showers occurred over the north and coast over-night into the 1st and over the mountains in the south during the daytime. The broad circulation of Category 4 Hurricane Matthew centered over the southeastern Caribbean dominated our weather during the first few days of the month. This supported a light and relatively dry northeasterly airflow during the 2nd through the 4th as Matthew moved north across the Caribbean towards western Hispaniola / Haiti and eastern Cuba. At upper levels a Tutt low over the western / central Caribbean moved west of our area by the 2nd and back east of our area by the 5th. This initially supported a convergent northwesterly flow aloft. However on the 2nd it supported isolated thunderstorms in the vicinity of the PGIA and the northern slopes of the Maya Mountains. Then by the 5th and the upper level northwesterly flow became a bit convergent. Weather conditions were mainly fair during the 7th, however during the 8th to 11th a relatively slack pressure gradient supported light winds and in a deep layer southerly flow with increasing upper level moisture, isolated thunderstorm developed in the south at night-time with showers and rain spreading across the country.
The upper levels became drier by Wednesday 12th due to a north-northwesterly flow from a ridge to the west. At low levels a surface trough across the northwestern Caribbean supported a north-northeasterly flow and mainly fair conditions through Thursday 13th. High resolution satellite imagery detected a cyclonic swirl of low clouds centered near 18N 84W and this produced showers over and offshore the south over-night and along the north coast and higher elevations inland during the daytime. This activity was supported by a weakly divergent westerly - southwesterly flow aloft from an upper level low south of western Cuba. This pattern of diurnal shower activity continued Through the 16th. During the 17th and 18th, light winds resulted in land breeze effect over-night. Showers developed mostly over the sea due to coastal convergence and shower activity affected the south and coastal areas during the night and early morning hours with additional activity developing inland and in the higher elevations at peak daytime heating hours. During the 19th showers moved from the sea to northern coastal areas. Then with the upper level high centered over the Gulf of Tehuantepec, the resulting northwesterly flow supported a drying trend through the 20th. Night-time / early morning showers were confined to mostly coastal waters during the 21st with isolated showers over the Maya mountains on the 22nd.
By the 23rd a cold front stalled over northern Yucatan with a shear-line developing between Hisopaniola and northeastern Nicaragua. Over our area a convergent / long fetch northeasterly flow developed, while at upper levels a trough extended down to the northwestern Caribbean with a ridge extending north from the eastern Pacific across Mexico and into the central United States. Afternoon showers affected mostly southern and inland areas, becoming generally isolated over-night into Monday 24th.
Remnant moisture from the dissipating frontal boundary drifted south and southwest from the northwestern Caribbean and supported mostly low-topped showers and periods of rain over most areas during the 25th. By the 26th a Tutt low was centered over Yucatan and provided support for a surface trough extending from the Bay of Campeche to the northwestern Caribbean Sea. Showers, periods of rain and isolated thunderstorms developed over and offshore northern and central areas of the country through the 27th. During the 28th a surface low over the northwestern Caribbean supported a northwesterly flow over our area and weather conditions turned out mainly fair with clear skies at night and little or no rainfall.
Cloudy conditions (layered low and high clouds) prevailed during the 29th and 30th with a moist southerly flow aloft and northwesterly low level flow which confined most showers and thunderstorms to coastal waters east of the reef. However by the evening, showers and thunderstorms developed from near SandHill south-southeastwards to just west of Dangriga and drifted westwards, with a few more developing over southern coastal waters during the night.