Rainfall Associated with Disturbed weather in NW Caribbean
By NEMO Information Unit
Jul 3, 2008, 09:00 am
Rainfall activity during the night was concentrated
over the Toledo
district. Satellite loop showed heavy showers and thunderstorms over the
central and SW Toledo district before
midnight, but the thunderstorms died off by 2:00 am.
Around dawn, the satellite pictures were showing
weaker rainclouds over and offshore the southern Stann Creek and northern Toledo districts.
Forecast models are resolving another half-an-inch
to 1 inch of rainfall per day for today, Thursday and Friday. On Saturday,
rainfall rates are projected to increase to 3-4 inches especially over central
coastal areas as an active Tropical Wave move over the country. Another 2
inches are expected for Sunday, thereafter the rates decrease for Monday and
Tuesday.
Satellite imagery indicates that the strong tropical
wave and surface low over the eastern Atlantic Ocean
has become organized during the night, enough to now be classified as a
tropical depression. Satellite images also indicates that a strong burst of
convection has persisted for over 12 hours near or just west of the apparent
center of the system. Banding features are also becoming more pronounced in the
northwestern part of the circulation. Therefore, with all of this in mind, we
now have Tropical Depression #2.
A mid-level high pressure system is currently
steering the storm towards the west-northwest at about 10 mph. This high
pressure system is forecast to become stronger over the next couple of days,
which should speed up the forward motion of the storm. The global and track models are in good agreement with the forecast track until
the system potentially reaches a break in the high pressure ridge along around
50 to 55 West Longitude on Monday or Tuesday. The bottom line is the stronger the storm
becomes, the quicker it will turn out to sea. In addition, I also am tending to
lean more towards the UKMET and European model forecasts since it appears that
a slow intensification is more likely than the quick and robust intensification
of the GFS, HWRF and GFDL models. So, it is entirely possible that the NHC
forecast track may be slightly too far north and the storm may take a track
closer to the UKMET model. Either way, it looks like the storm should stay north
of Puerto Rico, the Virgin Islands and the Lesser Antilles.
Vertical wind shear is forecast to remain light for the next few
days near this system, so the biggest limiting factor on the future strength of
the depression is the cooler waters and more stable air in its path. After
Friday, sea surface temperatures in the path of the storm drop below 80 Degrees
Fahrenheit and stay below that threshold until around Monday. Thereafter, sea
surface temperatures warm slightly and most of the global models forecast an
environment that would favor some intensification. Therefore, the current SHIPS intensity model looks too strong and I think a slow
intensification is possible over the coming days with a break in
intensification on Saturday and Sunday.
We are also watching an active tropical wave near
the Lesser Antilles. This tropical wave is not
expected to develop further due to strong wind shear ahead of this wave. With
that said, this tropical wave is expected to bring showers and thunderstorms
with heavy rains and gusty winds to the Leeward and northern Windward
Islands today. This TW will be over our region by Saturday,
bringing more showery weather across Belize.
Update on
River Levels last-night and this morning…
The
additional rainfall during last-night over the Toledo district may cause rivers
in that district to rise a few feet more today before receding slowly on
Friday.
The
gradual reduction in the rains over the next 24-48 hours will result in further
recession of water levels around the country.
Water
levels in both the Chalillo and Mojellon reservoirs are falling slowly, while
the current storage behind the Chalillo dam is at about 65% capacity.
The next update will be issued at 11:00am, Thursday
July 3, 2008.
R. Frutos, National Meteorological Services of Belize