Bermuda Weather Service Forecast Discussion

For Wednesday, April 17, 2024  09:00 UTC

FORECASTER - Duty Forecaster 

NOWCAST: (Today and tonight)
The night was partly cloudy for the most part and briefly became 
cloudier during the late night. No rainfall was observed over the 
island overnight, though isolated showers remained just outside of 
the border of the southeastern marine area. Latest satellite imagery 
shows partly cloudy skies as thin scattered to broken stratus cloud 
continue to stream over the island from the southeast. Latest radar 
imagery shows isolated to the southeast, finally beginning to dissipate. 
Upper troughing to the north begins to slide off to the northeast 
while upper ridging nudges in from the west from eastern CONUS as 
evident on WV imagery. Latest surface analysis shows a weakening 
frontal boundary descending from the north in between three areas 
of high pressure to our northwest, west-southwest and east-northeast 
respectively. This has initialized really well with global models 
and there is high confidence in the synoptic set up for today. Global 
models are in good agreement that the upper ridging continues to 
nudge in from the west and will become more dominant overnight. In 
addition, global models agree that the ridge of high pressure will 
once again keep lower pressure out of the area as the frontal boundary 
continues to dissipate as it nears the island. Nonetheless, the day 
should be mostly sunny with a slight increase in cloud expected overnight 
as the weak boundary draws near. Winds overnight at the airport and 
our AWOS, continued to vary in direction but generally backed from 
northeasterly to northwesterly whilst remaining around 5 knots.  
Currently, winds are still northwesterly near 5 knots and this has 
also initialized well with the global models and gives good confidence 
in the near term. Expect winds to veer northerly overnight while 
potentially becoming light and variable through the day and night. 
 Latest OPC has seas near 3-5ft which is in agreement with model 
initialization. Seas are forecast to remain in a mostly slight state.

Warning Strategy: No watches or warnings are in effect for today 
and tonight.

AVIATION: Runway 30 will be the active runway for the day as a northwesterly 
to northerly wind persists. VFR conditions may give way to MVFR and 
possibly IFR conditions early this morning as low cloud ceilings 
possibly develop per guidance from MOS and the UK cloud base model. 
No other aviation hazards are anticipated. For more information visit:

SHORT TERM FORECAST (Thursday through Friday)
Thursday begins with upper ridging but later in the day a shortwave 
trough approaches from the west to become set in by Friday morning. 
This upper pattern does suggest a trend to something more unsettled 
developing. At the surface, the pattern is complex and the models 
are not in especially good agreement. However, the general trend 
appears to be for ridging and mostly fair weather during Thursday. 
There is then likely to be an area of deepening low pressure towards 
the NW (in concert with the aforementioned upper trough) which introduces 
more in the way of cloud and a few showers to the area. The UK is 
the least aggressive of the models so far, and given the likes of 
the GFS can be overzealous in the medium range, the more conservative 
UK model approach is being taken for the moment. Seas will continue 
slight to moderate.

Warning Strategy: No watches or warnings are currently anticipated 
for the short-term period.

LONG TERM FORECAST (Saturday through Sunday)
The long-term period sees another weak frontal boundary passing 
through the area within a generally slack flow on Saturday before 
weak high pressure returns on Sunday. This should maintain generally 
fair weather, though occasional cloudy conditions can be expected 
with the chance of a few passing showers on Saturday. There is some 
model disagreement overnight on Sunday as the GFS advances another 
weak front well ahead of the model consensus. The forecast remains 
more tied to the UK and ECMWF solutions, which look more reasonable. 
The timing of weaker synoptic features is always a challenge to forecast, 
especially during transition months like spring. Nonetheless, the 
weekend does not look too bad. Winds remain light to moderate over 
the period and continue to vary within the slack flow. Slight to 
moderate seas persist.

Warning Strategy: No watches or warnings are anticipated for the 
long-term period.