Bermuda Weather Service Forecast Discussion

For Monday, October 21, 2019  20:00 UTC

FORECASTER - Kimberley Zuill 

NOWCAST (This evening & Tonight):
Moderate southerly winds have now veered slightly more SSW and a 
few observations from offshore sensors peak at 14 gusting 20 knots. 
Satellite imagery showed a narrow band of cloud depicting a convergence 
line just to our east, which this morning produced showers in our 
vicinity. We are now in a gap of cloud with only a few clouds at 
various layers spanning from cumulous to cirrus levels. As the night 
progresses and temperatures cool, the clouds upstream will shift 
over us turning our sky cloudy. Several narrow lines of convergence 
are seen on satellite images and models suggest the onset of moderate 
showers just before 06Z as the weakening front linked to a filling 
low to our northwest is dragged over us. Around and within showers 
winds are expected to become strong at times. Thus a small craft 
warning is in effect for early Tuesday morning, some of that timeframe 
is captured in the late night timing. OPC holds our seas around 4-5ft. 
No other watches or warnings are expected. 


AVIATION: Active RWY30 VFR, No watches or warnings in effect currently. 
For current airfield information please visit: http://www.weather.bm/Aviation

SHORT TERM FORECAST (Tuesday-Wednesday): 
There is global model consensus on the passage of the weakening 
front Tuesday morning, providing isolated showers, but little in 
the way of deep convection. K-index remains unimpressive as the boundary 
warms out and becomes shallow, due to the stretching out/thinning 
of the front as the low pulls more northwards and the overrunning 
higher pressure snuffing out existing activity. A brief reprieve 
is anticipated on Wednesday, though there may not be much in the 
way of sunshine, just a deck of SCu and light showers at times of 
thickening cloud. Winds remain in the southwest quadrant, setting 
up for the approach of the next weak front. Small craft warning is 
in effect for early Tuesday in the pre-front isobaric squeeze and 
convective shower activity, after which winds ease. 

LONG TERM FORECAST: (Thursday-Friday):
Whereas model guidance diverged for the long range in the 00Z run, 
the latest 12Z run has indicated more consensus on the synoptic pattern 
where winds remain light and variable under a small scale high centre 
and the narrow secondary front sinks slowly to our northwest, but 
does not officially cross over as the precipitation boundary remains 
to the north, almost using Bermuda as a fulcrum point as it pivots 
while simultaneously disintegrates to our immediate north. Wind remains 
light and variable for the long term forecast and showers remain 
either in the vicinity if not over the Island. Seas remain slight 
during that time. No watches or warnings are expected. 

TROPICAL: 
Tropical Weather Outlook
NWS National Hurricane Center Miami FL
200 PM EDT Mon Oct 21 2019

For the North Atlantic...Caribbean Sea and the Gulf of Mexico:

Tropical cyclone formation is not expected during the next 5 days.

...TROPICAL WAVES...

An eastern Atlantic tropical wave extends its axis along 39W from
03N-17N, moving W at 10-15 kt. Scattered moderate convection is
from 07N-15N between 33W-41W.

A central Atlantic tropical wave extends its axis along 47W from 

16N southward, moving W at 10-15 kt. Total precipitable water
imagery shows a large pocket of enhanced moisture coinciding with
the wave. Scattered moderate to isolated strong convection is
from 06N-11N between 41W and the wave axis.

A western Caribbean tropical wave extends its axis along 83W from
20N southward, moving W around 15 kt. This wave is depicted in 
model guidance. An upper-level low over eastern Nicaragua is
enhancing scattered moderate convection along the wave axis from
11N-14.5N between 81W-84W. Scattered showers are seen from 17N-20N
between 80W-85W.