Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Gray ME
1234 am EDT Sat Jul 12 2014
high pressure will build into New England overnight then slide
off the coast on Saturday...producing another day of sunny and
comfortable weather. A warm front will cross the area Sunday
morning...with a few scattered showers and thunderstorms possible
on Sunday. More humid air moves in Sunday night. A cold front will
approach from the west and stall over the area through Wednesday.
This will lead to a warm and humid period with scattered showers
and thunderstorms. The cold front will push through the region at
the end of the week with some improvement by Friday.
Near term /until 6 am this morning/...
updated to input latest observed data resulting in no changes to
the previous forecast.
High pressure will crest over the region tonight with clear skies
and light and variable winds. This will allow temperatures to drop into the
40s north and 50s S. Some patchy valley fog once again possible in
the Connecticut River valley late.
Short term /6 am this morning through 6 am Sunday/...
the center of high pressure will slowly move offshore but with a dry
west-southwest flow aloft. Another mostly sunny day expected. Temperatures
will be a few degrees warmer. Along the coast an afternoon sea breeze
is expected that may keep temperatures along the coast a little cooler.
Saturday night the return warmer southerly flow will be light but
allowing a slow increase in dew points. Some middle/high clouds will
overspread the region Saturday night so overnight temperatures
should be not as cool with lows in the 50s to lower 60s. Used a
blend of the models for temperatures.
Long term /Sunday through Saturday/...
500 mb troughing digs equatorward over the Great Lakes Sunday and
Sunday night...pushing a surface warm front across the region Sunday
which could set off a few scattered showers... especially in western
and northern zones. More humid air begins to work in as S-SW flow
develops...although Sunday will be more of the transition day with
dew points reaching into the low-middle 60s and highs upper 70s to
low 80s...with a mix of sun and clouds. The threat for
showers/thunderstorms will continue overnight as the surface cold
front creeps in from the west. Sunday will turn humid with lows in
By Monday...start to see Omega blocking develop across the
Atlantic at 500 mb with strong Atlantic ridging. This will hold up
the progress of the cold front somewhere in the vicinity of the
forecast area as it lines up with flow aloft. Monday will be humid
with dew points in the middle 60s to around 70 and we will scattered
showers/thunderstorms with the front nearby... and a mix of sun
and clouds. Monday night will be even less comfortable with lows
middle 60s to around 70. On Tuesday... it looks like a weak wave
will run NE along the front and will see more in the way of clouds
and a better chance for showers/thunderstorms during the day with
highs again upper 70s to low 80s.
The 12z Euro just came in much more progressive with the system
and clears it out by late Wednesday... while the 12z GFS stalls
it just offshore... as does the GFS ensemble mean. Keeping the
chance probability of precipitation for Wednesday... although could be some less humid
conditions if the front makes it through. Will have to watch for
how the models handle this block and the strength of the
Atlantic ridging... so forecast confidence late in the week is
low... but assuming the front makes it through... expect somewhat
less humid air behind the front for Thursday/Friday.
Aviation /06z Saturday through Wednesday/...
short term...VFR conditions through Saturday night except patchy
valley fog possible 06-12z at kleb.
Long term...while VFR looks predominant Sunday and Monday... some
scattered showers/thunderstorms could briefly reduce conditions
both Sunday and Monday during the day. Stratus and fog can be
expected to bring conditions to IFR Sunday night and again Monday
night. The best chance for for a more persistent period of flight
restrictions will be Tuesday in showers/thunderstorms.
short term /overnight through Saturday night/...updated to input
latest observed data. Lowered seas across the bays slightly for
the overnight period...otherwise no real changes. High pressure
builds into New England overnight then moves offshore Saturday
keeping winds and seas well below Small Craft Advisory levels through Saturday night.
An onshore flow around the departing high will be enhanced by a
sea breeze on Saturday afternoon into the evening.
Long term...while S-SW flow become persistent Sunday afternoon trough
Tuesday... winds will generally remain below Small Craft Advisory levels... although
could approach 25 knots Sunday night into Monday. The persistent flow will
likely bring seas up to around 5 or 6 feet in swell late Monday into