Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Gray ME
318 PM EDT Tuesday Jul 29 2014
upper level low pressure remains over the northeast for the next
several days. This will result in the chance of showers and
possibly a thunderstorm each afternoon especially in the
mountains. A front will approach from the south on Saturday. A
long wave ridge will build in to start the week.
Near term /until 6 am Wednesday morning/...
expect clouds to dissipate this evening. With a clear sky and
light winds temperatures will drop into the 40s and lower 50s
tonight. Expect some patchy dense valley fog to develop around 07z
Short term /6 am Wednesday morning through Wednesday night/...
fog will burn off in the morning. And will leave a clear sky for a
short time but expect cumulus to develop with the chance of mountain
showers during the afternoon. Upper low will remain to the west
through Thursday with a lobe of energy moving in early Thursday.
This will kick off showers before dawn on Thursday so probability of precipitation
increase Wednesday night. Will add some patchy valley fog late
Wednesday night also although fog may not be a big factor
depending on when the clouds and showers move in.
Long term /Thursday through Tuesday/...
Thursday starts with a long wave tough in place from James Bay down
to the Great Lakes. We will see several short waves move through
this trough before it finally begins to break down on Saturday.
Thursday will see scattered showers and thunderstorms as a short
wave moves out of the Great Lakes and through the region. Aloft a
jet streak will serve to concentrate convection along a line
extending from ack to yqb. Forecast soundings show 800-1000 j/kg
of cape with a significant portion in the hail growth zone,
combined with unidirectional deep layer wind shear severe
thunderstorms are possible, however at this point confidence for
all the factors combining together at the right time is too low so
have left just thunderstorms for the moment.
Scattered diurnally driven shower will continue for Friday and
Saturday as a series of short waves continue to provide limited
Forecast confidence decreases significantly by the end of the
weekend as several global models try to replace the long wave trough
with a high amplitude ridge...with varying timing and Success. Have
left probability of precipitation fairly low based on a consensus blend, but expect to see
some variability with the start of next week as it gets closer.
Aviation /19z Tuesday through Sunday/...
short term...expect mostly VFR except IFR in patchy valley fog tonight.
Long term... expect mostly VFR conditions through the weekend.
short term...will extend the Small Craft Advisory for seas through 3am Wednesday
morning. Otherwise quiet on the waters.
Long term...quiet waters no headlines expected during the extended.
Marine...Small Craft Advisory for hazardous seas until 3 am EDT
Wednesday for anz150-152.