Scientific Forecaster Discussion
fxus61 kaly 280741
Area forecast discussion
National Weather Service Albany New York
341 am EDT sun may 28 2017
the Holiday weekend is well underway as today will feature a mix
of clouds and sunshine. Temperatures will be milder, however,
there is a slight chance of a shower later this afternoon. The
chance for showers and some thunderstorms increase tonight
through Monday morning as a strong disturbances crosses the
region. Conditions improve a bit later Monday afternoon and
evening. Several quick moving systems will keep precipitation
chances in the forecast through mid-week with temperatures near
Near term /until 6 PM this evening/...
as of 330 am EDT...experimental GOES-16 depicts rather nicely
the stratus across 2/3rds of the County Warning Area this early Sunday morning.
However, breaks were occurring around the edges but being
replaced by convective debris from upstream convection with
CI/cs. So today will feature a diversity of cloud coverage as
even partial sunshine will assist with warming the boundary
layer. The hi-res nam3km and hrrr suggest with the daytime
heating, some initial terrain based showers develop once the
short wave ridge slides east of the region by early afternoon.
While difficult to ascertain any surface triggers, perhaps some
differential heating boundaries and weak instability might be
enough for isolated showers to develop as we will expand the
slight chance from the higher terrain into the valley locations
through the afternoon hours. Highs today should average between
70-75f for valley locations to 60s elsewhere. Marine influence
air may filter into the southern Catskills, Mid-Hudson valley
and northwest CT where clouds and slightly cooler temperatures may
Short term /6 PM this evening through 6 PM Monday/...
as seen in the experimental GOES-16 imagery, moisture transport
continues to advect northward across the Ohio Valley into the
central Great Lakes region. This moisture entrainment ahead of a
short wave racing across the Dakotas and into the upper
Mississippi River valley will aid in the development of showers
and thunderstorms upstream this evening. Model consensus
suggests this will evolve into a complex of showers and embedded
thunderstorms as low level jet magnitudes increase to at or
above 40kts overnight along and ahead of this impending complex.
Timing and placement points toward our western areas arriving
by 06z Monday then across The Heart of the County Warning Area around 12-18z
Monday. We will raise pops at or above categorical thresholds
per coordination with neighboring forecast offices. Overnight
lows will be milder with mainly 50s and highs on Memorial Day
rather cool with mainly 60s and upper 50s for the higher
terrain. The complex of showers/storms are expected to track
east of the region by mid afternoon, however, ample moisture
lingers along with mid level jet core arriving for the continued
threat for additional convection.
Long term /Monday night through Saturday/...
much of the extended period will be dominated by a longwave trough
in place over the northeastern United States, as a slow moving
closed off upper level low moves from the upper Great Lakes towards
eastern Canada through the week.
In the wake of the warm air advection/isentropic lift from Monday,
there looks to be a general lull in the precip for Monday night,
with just a few lingering rain showers, mainly for northern and
eastern areas. Have generally gone with slight to low chc pops for
Monday night, although it should remain fairly cloudy thanks to
plenty of lingering low level moisture with lows in the 50s.
Ahead of the approaching upper level, broad southwest flow will be
in place in the low to mid levels on Tuesday. A strong jet streak
of around 125 kts at 250 hpa will be approaching the area on
Tuesday, afternoon as some upper level energy slides around the base
of the upper level trough. 0-6 km bulk shear looks impressive, with
around 50+ knots of shear expected over the region. Instability may
be limited due to plenty of clouds around, but any breaks of sun may
allow for up to 1000 j/kg of cape. Although dewpoints will only be
in the 50s, considering the strong upper level forcing nearby, we
will need to monitor for the potential for some strong to severe
thunderstorms on Tuesday afternoon into early Tuesday evening. Storm Prediction Center
currently has the region in a "marginal" outlook for severe
thunderstorms at this time in their day 3 outlook. With a few
breaks of sun, highs should reach into the 70s for valley areas.
Although the best jet dynamics shift away from the area, some
additional rain showers will be possible on both Wednesday and
Thursday, mainly during the time of best diurnal heating, as the
somewhat cooler temps aloft combine with daytime heating and the
cyclonic flow in place to allow for instability-based showers. Temps
will generally be in the low to mid 70s for highs on Wednesday, with
mainly upper 60s to low 70s for Thursday. Sky cover looks to vary
between partly to mostly cloudy.
The flow aloft should briefly flatten out on Thursday night into
early Friday as the original upper level low weakens, however,
another closed off low will rotating out of central Canada through
the broad longwave trough towards the Great Lakes for the weekend.
While late Thursday night into Friday morning looks mainly dry, some
additional showers will return for Friday afternoon into the
weekend. Temperatures will be near to slightly below seasonal
Aviation /06z Sunday through Thursday/...
rather extensive mid level cloud deck with VFR conditions across
the taf sites this early Sunday morning. There are some breaks
occurring near kgfl where some IFR conditions with respect to
fog are possible overnight. Additional breaks in the clouds near
kpou may also result in temporary IFR conditions as well. Winds
to remain light and variable through the overnight period.
Skies should improve to all VFR through the daylight hours
Sunday as additional high and mid level clouds increase. Winds
will become southerly around 5-10 kt Sunday afternoon.
Sunday night: high operational impact. Likely rain showers...tsra.
Memorial day: high operational impact. Definite rain showers...tsra.
Monday night: low operational impact. Slight chance of rain showers.
Tuesday: moderate operational impact. Likely rain showers...tsra.
Tuesday night: moderate operational impact. Chance of rain showers...tsra.
Wednesday: moderate operational impact. Chance of rain showers.
Wednesday night: low operational impact. Slight chance of rain showers.
Thursday: moderate operational impact. Chance of rain showers.
seasonably mild temps today with relative humidity values mainly bottoming out
in the 50s with light to moderate southeasterly winds. Isolated
showers are possible this afternoon. An approaching system will
bring rainfall to the region tonight into Memorial Day, along
with cooler temperatures. Showers and thunderstorms will be
likely again on Tuesday with seasonable temperatures.
isolated showers are possible later today but chances for more
widespread rainfall arrives tonight. An approaching system will
bring showers and a few thunderstorms tonight into Memorial
Day, with total quantitative precipitation forecast ranging from 0.25-0.75" expected. Additional
periods of showers and thunderstorms are likely Tuesday and
Wednesday, with basin average quantitative precipitation forecast likely remaining less than an
additional half inch.
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.
the ASOS at the Floyd Bennett Memorial Airport in Glens Falls,
New York and Pittsfield Airport, Massachusetts continue to experience outages
with hourly metars occasionally missing. This will continue
until communications are fully restored.