Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Albany New York
125 am EDT Monday Apr 27 2015
an upper-level disturbance lingering across the region will
continue to bring cloudy skies tonight...with a few widely
scattered rain and snow showers primarily north of the capital
region. Mostly cloudy skies and widely scattered rain showers will
continue into the day Monday. High pressure will build across the
region Monday night into Tuesday bringing dry weather and partly
Near term /until 6 am this morning/...
as of 115 am EDT...infrared satellite imagery continues to show plenty
of clouds over the region...as a closed off upper level low
remains close to the region near southeastern Canada. Despite
these clouds...kenx radar doesn/T show much shower activity at the
current time...with only a few very light sprinkles near the Lake
George area. As moisture continues to rotate around the upper
level low...there will continue to be a slight to low chance for a
rain shower through the remainder of the overnight hours...mainly
for areas to the north of the capital region. With 850 hpa temperatures
at or just below freezing...it/S possible that a few high terrain
areas in the Adirondacks may see the precipitation may fall as snow
showers...but no accumulation is expected due to the very light
nature of any precipitation.
Overnight temperatures will fall into the 30s and 40s...with the coldest
temperatures in northern and high terrain areas.
Short term /6 am this morning through Wednesday night/...
the large upper low over the Gulf of Maine will thwart US for at
least one more day Monday. Guidance continues to indicate a slightly
stronger disturbance rotating through it...which will combine with
any heating of the day...to give US a better chance for scattered
showers on Monday (as opposed to widely scattered ones). These would
favor the higher terrain...but valley locations could certainly get
In fact...even with the clouds and scattered showers...we expect
similar high temperatures compared with today...55-60 in the
valleys....upper 40s to middle 50s higher terrain. A northwest wind
will pick up to 10-15 miles per hour with a few higher gusts.
The disturbance will move out Monday but the low will still impact
our weather with a few lingering clouds and perhaps showers. Lows
will be similar to Sunday night...generally bottoming out within a
few degrees of 40.
Tuesday into Tuesday night...the large upper low finally begins to
slowly migrate further east as the upstream ridge attempts to slide
in from the west. The question is whether or not the clouds are able
to scour out. Given it is nearly may with a 60+ degree angle sun at
solar noon...we lean a little more optimistically that we should at
least get some decent breaks of afternoon sunshine. As a
result...temperatures should get a bump on Tuesday...topping out in
the 55-60 range higher terrain...lower to middle 60s valleys. It will
turn a little breezy again...a north to northwest wind averaging 10
to 20 miles per hour. With a partially clear sky Tuesday night...northern areas
look to get chilly once more...tanking from the upper 20s to middle
30s...while areas from the capital region southward will bottom out
from the middle 30s to lower 40s...warmest right in the Tri-City
Wednesday looks like a decent day as that aforementioned weak ridge
builds over US along with h850 temperatures warming to about +5c.
With a good deal of sunshine...daytime highs could reach around 70
in the valleys...60s most of the higher terrain. The wind will be
northwest 5-15 miles per hour with a few higher afternoon gusts.
Dry weather will hold into Wednesday as some clouds increases. Look
for lows cooling to middle 30s to lower 40s.
Long term /Thursday through Sunday/...
the long term period starts out with a low confidence forecast as a
potential coastal storm impacts the region to end the work
week...with increasing confidence in dry weather for the weekend.
At the start of the long term period...weak ridging aloft will be
moving east of the region as a potent piece of shortwave energy
helps deepen a northern stream upper-level trough. Meanwhile...a
coastal low will be taking shape off the southeastern
There continues to remain much uncertainty regarding the evolution
and track of this coastal low...which will move northeast up the
eastern Seaboard during the Thursday and Friday timeframe. The main
player...which is having difficulty being resolved by the long range
guidance...is the aforementioned northern stream shortwave
energy...which will cause the upper-level trough to become cutoff
somewhere across the middle-Atlantic region. Depending on how far south
and east this shortwave energy GOES will determine how much and if
any interaction will occur between the coastal low and the northern
stream cutoff low.
If some phasing occurs...enough moisture could be thrown back
northwestward across the forecast area to result in a period of
rainfall Thursday into Friday night...with the best chance during
the day Friday. If little to no phasing occurs...the coastal low
will move well enough offshore to have limited effects on the
forecast area besides increased cloud cover and perhaps some
scattered showers across western New England. Since there continues
to remain much uncertainty and low confidence in this
forecast...have gone with a blended model approach and with chance
probability of precipitation Thursday through Friday...decreasing to slight chance Friday
As the coastal system pulls off to the northeast Friday night and
into the early portion of the weekend...forecast confidence
increases in a period of dry weather for the weekend as the region
is influenced by a sprawling area of high pressure occupying much of
the eastern third of the Continental U.S....resulting in partly cloudy skies
and gradually warming temperatures.
High temperatures Thursday will range from the upper 50s to middle 60s
with lows Thursday night ranging from the middle 30s to middle 40s. Friday
looks to be the coldest day of the long term...with highs ranging
from the upper 40s to near 60. Lows Friday night look to range from
the middle 30s to middle 40s. Temperatures will moderate Saturday and
Sunday...ranging from the middle 50s to middle 60s Saturday and upper 50s
to near 70 Sunday. Lows Saturday and Sunday night will generally
range from the middle 30s to middle 40s.
Aviation /05z Monday through Friday/...
mainly broken VFR ceilings are expected the remainder of the overnight
with a chance for borderline MVFR ceilings toward sunrise for kgfl-
kalb-kpsf. Some showers may impact kgfl where we will place a
Overcast VFR ceilings expected through the daylight hours Monday with
an increase in shower potential. We will begin with a prob30 group
north of kpou in the morning then place showers as a dominant
weather type through the afternoon hours. Kpou may remain dry due
to drier boundary layer and favorable downsloping component from
Winds will remain out of the north/northwest into the day
Monday...and generally be around 8-12 knots with gusts to 20 knots
Monday night: moderate operational impact. Chance of rain showers.
Tuesday through Wednesday night: no operational impact. No sig weather.
Thursday and Thursday night: low operational impact. Slight chance of rain showers.
Friday: moderate operational impact. Chance of rain showers.
it looks to remain rather cloudy through Monday. There is a slight chance
of showers this evening...and a better chance of showers by Monday
afternoon as disturbances continue to rotate through a large cutoff low
parked in the Gulf of Maine.
Rainfall amounts look light...well below a quarter of an inch.
The clouds will keep relative humidity from reaching very high levels tonight...generally
in the 75-80 percent range so only a partial recovery.
Relative humidity values on Monday will be in the moderate range (40-50 percent).
The wind will be northwest 10-15 miles per hour by afternoon with a few higher
Tuesday...it turns partly sunny and dry. Relative humidity values look a bit lower than Monday...
dropping to near 30 percent. The wind will a bit gusty possibly up to 25 miles per hour.
By Tuesday...it will likely be 5 days without any significant rainfall...so
we will have to monitor for any possible weather headlines.
Wednesday looks dry with rather low afternoon relative humidity values. However...
the wind should a little lighter than Wednesday.
the forecast will be dominated by a persistent upper level low
which will result in cool temperatures...breezy conditions at times
and chances for mainly light precipitation through early this week.
Any of this precipitation will have little if any impact on our
rivers and streams in our hydrological service area /hsa/.
Rivers and streams will continue to slowly recede with the cooler
temperatures and light scattered precipitation forecasted.
For details on specific area river and lakes...including observed
and forecast river stages and lake elevations...please visit the
advanced hydrologic prediction service /ahps/ graphs on our web-