Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Gray ME
331 am EDT Thursday Jul 28 2016
a weak frontal boundary will drop south out of Canada and into
northern New England today, bringing a chance for showers and
thunderstorms as it does so. The front slowly slips offshore on
Friday as low pressure track easts along the front offshore of
Cape Cod. This will bring another chance of showers Friday into
Friday night. Cooler, more seasonable temperatures return for the
weekend with dry conditions Saturday and another chance for
showers on Sunday into Monday.
Near term /until 6 PM this evening/...
a slow moving cold front will cross the forecast area from
northwest to southeast during the day today. Scattered showers and
possibly a thunderstorm will be ongoing over the northern
mountain regions early this morning. Instability will increase as
the system settles south this afternoon, triggering more showers
and thunderstorms. Dynamics appear to be insufficient for severe
weather today across Maine and New Hampshire.
It will continue to be hot, especially over southern interior
sections which will exceed 90 degrees this afternoon. A few
sections over southern interior New Hampshire could hit 95
degrees. This heat has been highlighted in some of our products.
Onshore winds will keep conditions cooler along the coastline.
However, this onshore component will increase dew point values
into the mid 60s.
Short term /6 PM this evening through 6 PM Friday/...
the cold front will slip off the coastline this evening and with
the loss of daytime heating, showers and thunderstorms will
gradually end over southern areas. This front will become quasi-
stationary once it reaches the southern New England coastline.
Patchy fog will once again redevelop over a more widespread region
than the last few nights.
Models are coming into better consensus as a coastal system moves
northeast along the front and across the southern New England
coastline Friday. Mesoscale models continue to indicate an area of
briefly heavy rainfall will cross southern sections during the
day, bringing temporary relief to the drought conditions. Further
to the north in northern New Hampshire and central Maine, the
precipitation will be much lighter.
The cloud cover and precipitation will keep temperatures confined
to the 70s on Friday. However modestly high dew points will make
it feel more humid once again.
Long term /Friday night through Wednesday/...
the models remain in general agreement on the long wave pattern
through early next week. A weak broad trough will offer some
relief from the heat early in the period as a slow-moving cold
front gradually pushes well south of the area. A weak low will
travel northeast along this slow-moving boundary late Friday
before the front finally clears the coast early Saturday. High
pressure and drier air follows for Saturday into Sunday. By late
Sunday the next shortwave and week surface reflection is
approaching from the south and west marked by increasing clouds
and a chance of showers. This system will linger on Monday with
clouds and unsettled weather. By Tuesday...the upper trough
retreats offshore with rising heights and a more westerly flow
aloft opening the door to building heat and humidity for the
remainder of the work week.
Aviation /07z Thursday through Monday/...
short term...VFR conditions are expected early this morning,
except for perhaps a few hours of patchy fog. VFR conditions
then becoming MVFR in developing scattered showers and
thunderstorms this afternoon and evening. After the showers end
this evening...fog will form and be more widespread.
Fri night...sct MVFR in -shra/-tsra.
Sun night - Mon...areas of MVFR in shra/tsra.
short term...conditions are expected to remain below small craft
thresholds through Friday...however winds may gust to as high as
20 kts today out over the open waters.
Sat...winds and seas may briefly approach small craft outside the bays.