Bermuda Weather Service Forecast Discussion

For Tuesday, March 28, 2023  09:00 UTC

FORECASTER - Anton Wiltshire 

Nowcast: Today through Tonight
Upper level cloud continued to stream over the area as low cloud 
occasionally moved in overhead. Cloud bases generally were in the 
800-1000ft range with ceilings dropping to 800ft at times during 
the night. Moderate westerly winds backed west southwesterly through 
the night increasing 15-20 knots while maintaining its direction. 
A warm front is currently just to the north of the area which brings 
the increased cloudy conditions through the area. Despite clouds 
rolling through, no showers were reported at the airfield. As the 
low pressure system moves to the northeast, the warm front will lift 
away from BDA and the island will slip into the warm sector for a 
while before the cold front comes barreling towards us. This will 
bring an ease to the cloudiness for a while and allow temperatures 
to climb into the low 70s F. In the upper levels, a near zonal flow 
is dominant aloft which keeps the neutral pattern. Most of the sferics 
to the northwest gradually diminished during the night with only 
a couple strikes observed during the morning. As the cold front moves 
overhead later, GFS model QPFs are still in the 2-2.5mm range, EC 
near 5mm and UK near 4mm.   A look at the latest satellite GOES IR 
imagery shows mostly cloudy skies across the area as cloud continue 
to drift in from the west/northwest with thicker cloud passing within 
150-200km to the north. The latest radar imagery shows the area echo 
free within 100km and a few moderate echoes further north of the 
island. The surface analysis at 0600Z shows a low pressure system 
to our north extending a frontal boundary to the northeast and high 
pressure holding to the south. West southwesterly to southwesterly 
winds 16-22 knots will decrease later this afternoon then veering 
west 10-15 knots by evening. Winds may become variable overnight 
for a while. The latest OPC analysis indicates seas near 6-7ft, which 
aligns well with global models and seas will maintain that moderate 
state. 
WARNINGS: A Small Craft Warning is valid this morning through this 
afternoon for winds in the 15-20 knot range. 

Aviation: VFR conditions will occasionally drop MVFR or possibly 
IFR as cloud move through later today with lower ceilings and weather 
that may wet the runway. Moderate to strong winds 16-22 knots from 
230-250 degrees will diminish 10-15 knots later and then possibly 
variable during the night. For more information, please visit www.weather.bm/aviation 
 

Short Term Forecast: Wednesday  Thursday 
On Wednesday as the upper trough further descends into the area, 
zonal flow swings into cyclonic flow aloft with BDA on the front 
side of the upper trough but as the trough moves out to the east 
Bermuda then moves to the backside of the trough by Thursday afternoon. 
At the surface, as a frontal boundary sinks into the area, fragmentation 
occurs along the boundary as it drifts overhead which may allow a 
few settled gaps interspersed with cloudy conditions and showers. 
As the boundary lingers, a low to the west is dragged through the 
area into early Thursday. GFS and ECMWF QPFs hint at near 1.25 of 
accumulated rainfall expected on Wednesday while the UK model solution 
is just above 0.5, either way Wednesday sees a bit of rainfall. 
As the boundary slips out to the southeast, high pressure builds 
in from the west bringing settled weather into the area though a 
few showers may linger. With a northerly flow, cooler and drier air 
is pushed into the area allowing temperatures to drop near average. 
With the favorable upper support, influx of moisture, and development 
of the low on our doorstep, the potential for thunderstorm development 
increases to a moderate level, especially on Wednesday. Wind data 
within the model suite differs quite a bit with a 15-20 knot difference 
between the GFS and the UK and EC. Both European models are hinting 
at a southwesterly wind 20-30 knots while the GFS has winds light 
to moderate at 6-12 knots. Seas remain moderate during the short 
term.  

Warnings: No watches or warnings are currently expected, though 
if the UK/EC models are right then a Small Craft Warning may be needed 
on Wednesday. A Thunderstorm Advisory may become warranted on Wednesday. 


Long Term Forecast: Friday  Saturday 
On Friday as surface ridging takes hold, an early shower or two 
is possible as moisture moves around the edges of the high. On Saturday 
things remain quite bright and sunny. Light to moderate near northerly 
winds veer to the east then to the south by Saturday. Winds then 
ramp up overnight on Saturday into the moderate to strong range which 
would trigger the issuance of a small craft warning.  Upper level 
ridging amplifies on Friday into Saturday which will provide suppression 
from aloft. Temperatures slightly warm going into Saturday with a 
maximum in the low 70s F. Seas are expected to remain in a moderate 
state during the long term forecast period. 

WARNINGS: A Small Craft Warning may be required Saturday night for 
strong winds. No other watches or warning are currently anticipated 
during the long term period.