Bermuda Weather Service Forecast Discussion

For Wednesday, February 20, 2019  07:00 UTC

FORECASTER - Gary Hall 

NOWCAST (Wednesday morning through Wednesday night)
Widespread stratocumulus seem in the cool air field overhead and 
upstream as low level cold air advection continues due to as high 
pressure building in from the north. Temperature advection is expected 
to become neutral by this evening, thus holes in the broken decks 
should increase heading into the next period. Both the UKMO and GFS 
peak our surface pressure at 1030MB this evening then as weak warm 
air advection returns late tonight and beyond the pressure will subsequently 
begin to fall. Model output is in good agreement for the current 
to moderate to strong winds to decrease steady moderate this morning 
then further easing to light by tonight while veering northeasterly 
then settling southeasterly late overnight. Current rough seas are 
also expected to abate to moderate levels by this afternoon, thus 
the Small Craft Warning that runs through this morning will be allowed 
to expire at its scheduled end time of noon today. MOS has the high 
today only reaching 63F, though if we see a brief poke of sun we 
could reach 64-65F, especially since our sea surface temperature 
is still in the 67-68F range. 

AVIATION: Ceilings in the 4K range will be dominant today and tonight 
with a very light sprinkle or two in the area, though no reductions 
in visibility expected. Winds begin northerly 10-15 knots then veer 
northeasterly this afternoon while decreasing 8-12 knots, and eventually 
settle southeasterly 4-8 knots late overnight. For current airfield 
information please visit: http://www.weather.bm/Aviation

SHORT TERM FORECAST (Thursday-Friday): 
A general warming will occur on Thursday while southwesterly winds 
increase through the day to reach Small Craft Warning criteria by 
late afternoon, or early evening at the latest. Cloud cover should 
also wane Thursday under the increased warm air advection, though 
some cirrus is likely to filter in Thursday night and Friday ahead 
of a weak cold front approaching from the north-northwest. There 
is not much upper level dynamic support with this front and at this 
time very little precipitation is expected with passage during Friday 
afternoon, though a brief period of drizzle may intermix with a shower 
or two. The models continue to be in good agreement with the mid 
to late afternoon passage and wind veer to the northwest behind the 
front while decreasing to mainly moderate levels Friday evening and 
night. The Small Craft Warning will end shortly after frontal passage 
as well as the seas are not expected to stay at rough levels for 
very long. Cooler temperatures will return behind the front heading 
into weekend, with ocean stratocumulus likely returning. 

LONG TERM FORECAST: (Saturday-Sunday):
Pressure recovers on Saturday as a 1028MB high centre passes by 
to our near north. This will cause the winds to veer easterly by 
Saturday evening then southeasterly Saturday night all the while 
remaining rather light. Cloud will be on the decrease Saturday night 
and into Sunday, though there may be isolated shower activity develop 
during the day on Sunday as a distant low and warm front will be 
to our north. This will put us back into warm sector type weather 
with increasing southwesterly winds that will once again reach Small 
Craft Warning criteria by Sunday evening. The associated cold front 
is not expected to reach Bermuda until Monday so no cooling will 
occur during this period. Overall it looks to be a fairly nice late 
February weekend with sunny spells and a high of 70F come Sunday. 
Confidence continues to be high due a relatively simple pattern for 
the models to resolve.