|Monthly Weather Summary|
Monthly Weather Summary
NATIONAL METEOROLOGICAL SERVICE OF BELIZE
Climatology shows that the main features influencing weather across the country of Belize in December are cold fronts, upper level troughs and the development of moist northeasterly airflows in the area. There was no frontal passage in December of 2016. However, rainfall was above normal for most areas and this was caused by a rather moist tropical air mass that affected the country. Additionally, an upper level ridge persisted over the southwest Caribbean for a major part of the month. This blocked the fronts from entering the area and also supported instability aloft which resulted in deep convection over the area particularly on the 26th of the month.
On the first day of December a marginally moist and light easterly airflow over the area supported cloudy skies at times with a few showers mainly over northern coastal areas of the country. A slack pressure pattern dominated from the 2nd through to the 3rd and moisture also decreased over the area. This supported mainly fair conditions with only isolated showers across the country. The flow veered even further to the east-southeast on the 4th and 5th supporting mainly fair, warm and mostly dry weather. Similar weather continued on the 6th but isolated showers affected inland areas on that day.
In response to a cold front that descended into the Bay of Campeche on the 7th and later became stationary over extreme northern Yucatan, the surface flow backed to the east on the 7th and then to the east-northeast on the 8th through to the 11th. This resulted in a gradual increase in moisture over the area. While the 7th was still mainly fair with only isolated showers, the 8th became cloudy at times with a few showers across the country and similar weather persisted through to the 11th of the month.
Moisture would increase further on the 12th as a trof developed over the western Caribbean linked to a low pressure system crossing Nicaragua. This resulted in cloudy skies with a few showers and periods of rain. The trof was almost over the country on the 13th causing a moist northeasterly surface flow to develop. Furthermore, the upper levels were quite divergent and this supported cloudy skies with several showers, periods of rain and thunderstorms over the country. This was the first major rainfall event for the month resulting in rainfall totals of over an inch in the Belize City, Ladyville and the San Pedro Area. Conditions continued moist and unstable on the 14th but rainfall occurred mostly in the south that day with Punta Gorda receiving about an inch of rainfall.
Moisture decreased on the 15th and 16th but a few showers still affected southern and central areas of the country. Improvements continued on the 17th as the flow veered more to the east and by the 18th a dry easterly to southeasterly flow supported mainly fair conditions with only isolated showers.
The surface flow shifted abruptly to the east-northeast on the 19th as a cold front entered the central Gulf of Mexico. Additionally, the flow was convergent and gusty over the area. This factor coupled with an increase in moisture supported cloudy skies at times with a few showers across the country on the 19th and 20th of the month. Additionally, a broad trof developed over the northwest Caribbean on the 20th and persisted through to the 21st. Therefore, the gusty northeasterly flow persisted but showers decreased on the 21st. By the 22nd conditions were mainly fair with only isolated showers. Conditions continued relatively dry over the area on the 23rd but moisture increased later in the night resulting in an increase in showers.
Conditions were relatively moist on the 24th and 25th resulting in cloudy skies at times with a few showers. These occurred mostly in the south on Christmas Day. Weather conditions deteriorated further on the 26th as an upper ridge east of the area coupled with trofing to the west supported a divergent and moist South-Southwesterly flow aloft. Skies were cloudy to overcast that day with some showers, thunderstorms and periods of rain over most areas. This was the second major rainfall event for the month. Belmopan in the west and Kendall in the south recorded almost an inch and a half of rainfall.
Relatively moist conditions persisted over the area from the 27th through to the 29th although the upper levels had become less divergent. The result was cloudy skies at times with a few showers mainly over central and southern areas. Moisture decreased further on the 30th and 31st resulting in partly cloudy skies with shower activity becoming generally isolated.
The graph and maps below show the rainfall recorded in December 2016 versus the climatological mean for the month for a few of the weather stations across the country. These graphics show most stations recorded above average rainfall except for those in the western Cayo District that recorded below average.