Bermuda Weather Service Forecast Discussion
For Thursday, September 28, 2023
19:00 UTC
FORECASTER - Kimberley Zuill
NOWCAST: This Evening through Tonight
Another fair day while weak surface high pressure meanders nearby
keeping light winds NW until late afternoon when they backed W. Overnight
as the high drifts closer, light local winds will become variable
in direction then settle to the SE towards dawn. For the most part,
conditions will remain dry with a few cumulous clouds and the thin
veil of cirrus thickening at times into a broken layer. RADAR has
shown showers to our distant north, well beyond the marine area,
associated with the nearly stationary boundary located there. In
the upper levels we remain between anticyclonic flow to our SE and
broad troughing to our distant north. Latest OPC has seas near 5-7ft
which is in agreement with model initialization.
WARNINGS: No watches or warnings are in effect.
AVIATION: RWY30 W wind 5-8 knots become variable in direction then
settled SE by dawn. VFR conditions and no aviation hazards are anticipated.
For more information visit: http://weather.bm/aviation/
SHORT TERM FORECAST: Friday through Saturday
By Friday upper troughing to the north sinks further into our area,
while on the surface, a low becomes more organized to our northwest
and with the south through SW flow bands of convergence develop ahead
of the main front, which may bring a few showers overnight on Friday
with the main front reserved for Saturday morning. Temperatures rebound
on Friday into Saturday within the S through SW flow and the humidity
rises in advance of the first of a series of weak troughs approaching
from the W through NW. Seas of 5-7ft will decrease slightly Friday
night to become 5-6ft.
WARNINGS: No watches or warnings are currently anticipated for the
short-term period.
LONG TERM FORECAST: Sunday through Monday
In the early hours of Sunday, in the pre-frontal flow and within
any showers we may experience occasional gusty conditions. The UK
solution is still the more robust and indicates clusters of heavier
showers with indices supporting possible thunderstorms, whereas the
GFS has a more fragmented and shallow boundary. The timing of the
wind shift and cessation of rainfall is also delayed in the UK solution,
however overnight there will be less shower activity and eased westerly
winds that may fluctuate either side of west at times. Confidence
is low as the models keep fluctuating the location and intensity
of showers, as well as if the low in our region will be a single
centre or double or triple! The overall pattern places us in the
middle with 3-4 separate large scale surface lows looming on our
distant horizons, in all four corners of the compass! Moderate winds
fluctuate either side of west during Monday but confidence is low,
based on the uncertainty of if there will be a low centered to our
near north (UK solution) or to our NE (GFS). All models indicate
light precipitation in and around our area, possibly forming a secondary
trough, but we shall have to see the development and positioning
of the low in order to have higher confidence on those particulars.
By Monday as the low tends to start to lift out of our area but
light precipitation is scattered around, generally it looks like
there will be a drying trend and winds look to finally veer NW later
on Monday. Temperatures have been forecast as such, and therefore
we may have a brief “fall feel” to the air by Monday evening. Slight
to moderate seas persist.
WARNINGS: No watches or warnings are currently anticipated for the
long-term period, though if the UK solution trends towards reality
then a thunderstorm advisory may be issued for Sunday morning/early
afternoon.
TROPICAL: BWS are issuing TUBs on TS Philippe and TS Rina (which
formed at noon). Please refer to the latest Tropical Weather Outlook
(TWO) courtesy of the National Hurricane Center (NHC) for more details
via https://www.nhc.noaa.gov/