Bermuda Weather Service Forecast Discussion

For Thursday, March 23, 2023  08:00 UTC

FORECASTER - Troy Anderson 

Nowcast (Thursday)
Overnight, partly cloudy skies continued as low-level moisture from 
the east caused a few light showers to drift into the area. Light 
to moderate northeasterly winds veered towards the east and eventually 
southeast. A few light showers passed through the area from the east 
during the evening before exiting overnight.

The latest GOES 16 IR imagery shows Bermuda within few to scattered 
amounts of maritime stratocumulus clouds and under thin upper cirrus 
spilling over from the west. The latest RADAR imagery remains clear 
and echo-free in our immediate area. In the upper-level outlook, 
Bermuda moves to the backside of a broad upper trough with a strong 
upper ridge moving in from the west. This will help encourage the 
suppression of surface development from aloft through the day. Near 
the surface, a ridge of high pressure is due to move from our north 
to our northeast and eventually east. This will move Bermuda towards 
the western flank of the ridge maintaining the settled regime and 
allowing plenty of sunshine for the day. Light to moderate easterly 
winds begin the day before veering towards the southeast and south 
overnight. 

Cloud cover within the NWP suite remains variable today but diminishes 
during the afternoon. QPFs remain near 0 mm and a rather dry day 
is anticipated. A few partly cloudy spells are likely during the 
day as Bermuda transitions towards the western flank of the high. 
Wind data eases and veers winds from the E towards the SSE. Global 
models continue to align quite well with the pattern and moderate 
to high confidence exists. Temperatures begin to rebound slightly 
under the traversing high. Ranges increase towards the mid-to-upper-60s 
and minimums falling towards the mid-to-low 60s (F). With the passage 
of low-level cloud cover, easing and veering east to southeasterly 
flow, and WAA, temperatures will likely reach the expected high of 
66F (+/- a degree or so). The UK and GFS wave models continue to 
reduce states from the 6-8-foot range through the day and moderate 
seas are slated to persist. The latest OPC analysis shows 6-8-foot 
seas offshore within our area with the expectation for heights to 
gradually fall. With all forecast parameters below the watch and 
warning criteria, no watches or warnings are anticipated for the 
nowcast period. 

Aviation: VFR conditions begin the period at TXKF as light to moderate 
winds near 08-12 knots from 080-100 degrees veer towards southeast 
and ease towards the 5-8 knot range. RWY 12 will likely be active. 
For more information, please see www.weather.bm/aviation  

Short-Term (Friday- Saturday) 
During the short term period, strong upper ridge moves in from the 
west and maintains the suppressive forcing from aloft through the 
period. This will continue to suppress surface development through 
the period. Near the surface, high pressure will weak slightly as 
the center of the ridge moves off to the distant east and a low pressure 
to the distant northwest moves into the Atlantic. This will move 
Bermuda south of the warm sector of the passing low pressure system 
through Friday. Then on Saturday, while the first low moves to the 
northeast, a second low will near the US northeast coast. A boundary 
is due to link the two and this feature will begin to sink down towards 
the Island. Global models keep the regime quite dry as Bermuda transitions 
from warm sector to warm sector. Wind data swings winds around to 
the southwest and increases speeds later on Saturday towards the 
upper bounds of the moderate criteria. There exists a brief window 
for winds to become moderate to strong from the evening and overnight 
periods, especially as the boundary creeps closer and closer. Then 
on Saturday, winds veer towards the west and then begin to ease. 
A good mix of sun and clouds will continue through the short term 
period with increases to cloud cover during the nights. The UK and 
GFS wave models both hold moderate states through the period with 
heights 4-6 feet on Friday and 5-8-feet on Saturday. A Small Craft 
Warning becomes likely from Friday evening and lasts through the 
night. Thereafter, no other watches or warnings are anticipated.

Long term (Sunday- Monday)
Then on Sunday, Bermuda slips into the second warm sector of the 
low moving from the northwest to our north. This pattern looks to 
increase winds out of the WSW and SW becoming moderate once again 
within the 12-18 knot range. Temperatures continue to gradually increase 
pushing into the 70s F and low nearing the mid-60s. A boundary will 
descend from the north and graze the area from the north. The consensus 
within the global models keeps the boundary outside of the area to 
the north before the stalling. Then, another low moving into the 
Atlantic from the northwest will merge with the moisture to the north 
and is expected to lift northward. A warm front will help bring rain 
and showers nearby overnight. Concerning seas, states and heights 
fall remain below the 9-foot threshold and are expected to fluctuate 
within the 5-8-foot range. No watches or warnings are anticipated 
for the long term period.