Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Albany New York
1006 am EDT Tuesday Jul 29 2014
high pressure will build into the region resulting in a fair
but cool day. Disturbances will move over the region about a large
low in the upper levels of the atmosphere as we head through the
middle of the week. Isolated to scattered showers and
thunderstorms are expected mainly during the afternoon hours
Wednesday and Thursday. The activity is expected to be more
widespread on Thursday due to a stronger disturbance.
Near term /until 6 PM this evening/...
some fair weather clouds are beginning to form...and most of the
clouds should affect areas of higher terrain. So...with sunshine
through this afternoon...decent mixing even as we advect cooler
air at low levels. Based on area 12z soundings and current
observations and trends...few changes if any to the forecast
through this afternoon. Highs in the 70s...but some 60s in higher
Short term /6 PM this evening through Thursday night/...
the region will be under the influence of the large closed low as it
wobbles over eastern Canada as short waves will rotate about it.
With the help of daytime heating isolated to scattered showers and
thunderstorms will occur. The activity is expected to be more
widespread on Thursday affecting more of the forecast area as a
stronger short wave approaches and passes overhead.
Daytime highs are anticipated to fall a bit short of normal for late
July. Nighttime will be on the cooler side running about 10 degrees
below normal tonight and around 5 degrees below normal Wednesday and
Long term /Friday through Monday/...
the long term period will be dominated by a trough over the
northeast...and strong ridging in the western portion of the Continental U.S..
The upper level low situated over southern Canada will be
weakening...however...enough of a weakness...combined with cyclonic
flow and daytime heating...will be enough to continue a threat for
showers and thunderstorms for Friday through the entire weekend. The
best chance of a shower/thunderstorm will be in the afternoon and early evening
hours...thanks to heating. Temperatures look seasonable...with highs north the
70s to low 80s...and lows in the 50s to low 60s.
There will be a continued threat for showers and thunderstorms even
into Monday as the upper level trough remains over the northeastern
Continental U.S....even though it won't be as pronounced and the trough won't
certainly be as sharp in amplitude. As a result...temperatures will be a
little warmer than the weekend for Monday...with highs in valley
areas reaching well into the 80s...but the threat for an
afternoon/evening shower or thunderstorm will continue.
Aviation /14z Tuesday through Saturday/...
an upper level disturbance is situated just north of the region over
Canada. Cyclonic flow around this system is allowing for some
passing clouds...especially in upslope favored locations of the Berkshires.
This is causing a period of MVFR ceilings at kpsf. However...as drier
air works in from the west...these clouds will start to scatter
out...and flying conditions will become VFR for all taf sites by middle
VFR flying conditions will be in place for the remainder of the day
with just scattered diurnal flat cumulus. Light westerly surface winds will be
around 5-10 kts. The clouds will start to mainly dissipate for
tonight...with just a few lingering clouds around 5-6 kft...and
winds becoming light to calm at all sites. This may allow for a
period of MVFR/IFR fog late tonight at kgfl/kpsf...otherwise VFR
conditions look to continue.
Wednesday night: no operational impact. No sig weather.
Thu: moderate operational impact. Chance of rain showers...tsra.
Thursday night: no operational impact. No sig weather.
Fri: moderate operational impact. Chance of rain showers...tsra.
Friday night: low operational impact. Slight chance of rain showers.
Sat: moderate operational impact. Chance of rain showers...tsra.
low pressure will move northward away from the region today allowing
higher pressure to build in resulting in a fair but cool day.
Disturbances will move over the region about a large low in the
upper levels of the atmosphere as we head through the middle of the
week. Isolated to scattered showers and thunderstorms are expected
mainly during the afternoon hours Wednesday and Thursday. The
activity is expected to be more widespread on Thursday due to a
Minimum relative humidity values are expected to be in the 40 to 50
percent range this afternoon and again Wednesday afternoon. A
recovery to 80 to near 100 percent is expected for the overnights.
dry weather is expected today which will allow river and stream
levels to recede. However...the weather will be unsettled this
week with chances for showers and thunderstorms mainly during the
afternoon hours as the region remains under the influence of a
large upper level low over eastern Canada. This low will wobble
over eastern Canada as short waves rotate about it. The low will
begin to weaken as we head into the weekend however the threat for
storms will continue.
For details on specific area rivers and lakes...including observed
and forecast river stages and lake elevations...please visit the
advanced hydrologic prediction service /ahps/ graphs on our website.