Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

fxus61 kaly 270225 

Area forecast discussion
National Weather Service Albany New York
1025 PM EDT Mon Jun 26 2017

an upper level disturbance will move across the region this
evening with mainly isolated to scattered showers and
thunderstorms. An upper level low and a cold front will bring
additional scattered showers and isolated thunderstorms on
Tuesday, with cooler than normal temperatures. High pressure
will build in from the mid Atlantic region by Wednesday, but
temperatures will still run slightly below normal for late June.
A warm front approaching from the southwest will bring more
showers and possible thunderstorms for Thursday.


Near term /until 6 am Tuesday morning/...
as of 1015 PM EDT, scattered convection continues with a couple
line segments moving through mainly north of the Mid-Hudson
valley. While expectations are this convection to slowly
diminish through the late evening hours, water vapor loop reveals
an enhanced mid level jet rounding the base of the upper low.
Some showers have developed across eastern PA which per the hrrr
may bring another round of showers just south of Albany
overnight. For now, we will introduce a slight chance pop and
monitor trends. As for temperatures, where convection did
occur these values did drop back rather quickly. Overnight lows
look good per previous excellent forecast with no changes at
this time with regard to overnight lows. Did add some patchy fog
to the forecast/grids as well with moist lower level
environment, especially where precip occurred.

Prev disc...
latest WV satellite imagery suggests one small
upper level impulse tracking east/NE along the southern shore of
Lake Ontario, with another tracking east/NE across Lake Erie. The
combination of these two impulses will allow a continuation of
isolated to scattered showers/isolated thunderstorms to linger
well into this evening for areas mainly near and north of I-90,
with much less coverage, if any, to the south, which will be
farther from upper level dynamics and instability.

Again, any taller convective elements will continue to have the
potential to produce small hail/locally gusty winds this
evening, especially if any cells merge into small line

Convection should diminish toward and especially after midnight,
with partly cloudy skies continuing. Some patchy fog could form
in any areas which receive appreciable showers this evening.

It will be cool once again tonight, with lows mainly in the 50s.


Short term /6 am Tuesday morning through Thursday night/...
Tuesday, the main upper level trough is expected to slowly
translate east across the region during the late morning and
afternoon hours. The combination of forcing ahead of this
feature, and developing low/mid level instability with the cold
pool aloft and any breaks of morning sunshine should once again
contribute to scattered showers/isolated thunderstorm to develop
in the late morning through early evening hours, with the
greatest coverage once again expected mainly from the I-90
corridor and points north. Also, with low wet bulb zero heights
and still relatively strong winds aloft/evaporational cooling
potential, will continue mention of gusty winds/hail with
thunderstorms. Forecast soundings suggests similar sb cape
values to today, generally reaching 400-800 j/kg, perhaps
locally higher where dewpoint pooling occurs. Highs should reach
the lower/mid 70s in valleys, with mainly 60s across higher
terrain, however temperatures will likely fall into the
50s/lower 60s once the core of any showers/storms pass by.

Tuesday night, any lingering convection should diminish fairly
quickly after sunset, with some clearing expected. Once again,
it will be cool, and some patchy fog will likely form in some
areas where appreciable showers occur prior to any clearing.
Lows mainly in the 50s, with some 40s possible, especially
across higher terrain.

Wednesday-Wednesday night, although the main upper level trough
should finally move east of the region, lingering cold air aloft
and possible weak disturbances rotating south/southeast on the
west side of the departing trough could initiate isolated
showers or perhaps a thunderstorm across portions of the
southern Adirondacks, the Lake George region and southern Vermont in
the late morning through afternoon hours. Otherwise, mainly
sunny and a bit warmer, with highs reaching 75-80 in valleys,
and upper 60s to lower/mid 70s across higher elevations. For
Wednesday night, clear to partly cloudy, with clouds more likely
to increase toward daybreak. Lows mainly in the 50s.

Thursday-Thursday night, increasingly active weather expected
once again, as a warm front approaches from the southwest. A
strong low/mid level jet Max, with h850 winds 40-50 kt, will
impinge on western areas by late morning, and most central and
northern areas by afternoon. There could be some form of an mesoscale convective system
spreading across central/northern areas late morning into the
afternoon, possibly in a weakening form, although new convection
could refire along its southern edge given the strong low level
warm advection. Trends will have to be watched. For now,
certainly expect showers and some embedded thunderstorms to
develop from west to east across the region during the late morning
through afternoon hours, with additional clusters of
showers/thunderstorms potentially continuing well into Thursday
night, especially for areas near and north of I-90 where the
greatest forcing from warm advection should occur. Highs
Thursday mainly in the 70s, although some southern areas could
surge into the 80s late in the day depending on the placement of
the warm front, with mainly 60s expected for lows Thursday


Long term /Friday through Monday/...
active weather is anticipated through the duration of the long term
period, with the potential for showers and/or thunderstorms each day.

At the start of the long term period, our region will be situated
within west-SW flow in the low to mid levels, allowing 850 hpa temps
will have warmed up to about 16-18 degrees c. A Flat Ridge will be
in place over the area, and some subtle disturbances at 500 hpa will
be sliding through the fast flow aloft.

Despite no nearby surface boundaries, daytime heating will allow for
scattered showers and thunderstorms to develop on Friday, especially
across the higher elevations, and then drifting into the valley
areas. While not everywhere will see a shower or T-storm, there is
the chance for a brief one to occur just about everywhere across the
area, with temps rising into the 80s. It will also feel rather
muggy with dewpoints well into the 60s to near 70 f.

While the chance for showers/T-storms may slightly diminish on
Friday night, there will be another good chance to see some showers
and thunderstorms on Saturday, especially for northern areas, as a
pre-frontal trough starts to approach the area from the west. With
the warm and humid airmass in place, will need to watch for some
locally strong to severe T-storms on Saturday afternoon, although
this will ultimately depend on the exact amount of instability and
shear in place. It looks to be another warm and muggy way with highs
well into the 80s once again.

As low pressure passes by to the north across southern Canada, a
cold front will be passing through the area on Sunday. This will
allow for some additional showers and thunderstorms. If the timing
on the latest 12z GFS is correct, the best chance would be early in
the day, although this is certainly subject to change, as timing
differences can be expected this far out.

Behind the front, somewhat less humid air will start to work into
the area. Still cannot totally rule out a stray shower thanks to a
nearby upper level trough, but most places look dry behind the front
on Monday with temperatures near seasonable levels.


Aviation /02z Tuesday through Saturday/...
a quick update to the kalb-kgfl taf's. For kgfl, an area of
clearing before the next potential round of clouds and showers have
allowed for IFR conditions to quickly evolve. As for the line(s) of
showers, the deeper convective elements appear to be tracking south
of alb yet we will place a tempo group for the next few hours to
account for lightning activity that may evolve.

Otherwise, a couple rounds of showers are possible north of kpou
through this evening. While VFR conditions should prevail through
the taf forecast cycle ending 00z Wednesday, some exceptions could
occur with patchy fog development overnight and shower potential
through the daylight hours Tuesday with mainly lower ceilings.

Winds diminish to less than 6 kt tonight. Winds become south to
southwest Tuesday morning at less than 10 kt.


Tuesday night: isolated rain showers...tsra.
Wednesday: low operational impact. Breezy no sig weather.
Wednesday night: no operational impact. No sig weather.
Thursday: high operational impact. Likely rain showers...tsra.
Thursday night: high operational impact. Likely rain showers...tsra.
Friday: moderate operational impact. Chance of rain showers...tsra.
Friday night: moderate operational impact. Chance of rain showers...tsra.
Saturday: high operational impact. Likely rain showers...tsra.


Fire weather...
an upper level disturbance will move across the region this
evening with mainly isolated to scattered showers and
thunderstorms. An upper level low and a cold front will bring
additional scattered showers and isolated thunderstorms on
Tuesday, with cooler than normal temperatures. High pressure
will build in from the mid Atlantic region by Wednesday, but
temperatures will still run slightly below normal for late June.
A warm front approaching from the southwest will bring more
showers and possible thunderstorms for Thursday.

The relative humidity values will recover to 85-100 percent overnight, dropping
to values in Tuesday afternoon will be in the 35 to 60 percent

The winds will from the southwest to west at 5 to 10 mph
tonight. The winds will increase from the southwest to northwest
at 5 to 15 mph Tuesday.

Winds will be stronger, and variable in direction in and near
any thunderstorms.


no widespread hydrological problems are anticipated over the
next several days. Scattered showers and isolated to scattered
thunderstorms are expected this evening through Tuesday, mainly
during the afternoon and evening hours, as a series of
disturbances impact the region with an upper low. Basin average
rainfall amounts will generally be a tenth to a quarter of an
inch in some locations.

A brief period of mainly dry weather is expected most of
Wednesday into Wednesday night with ridging from the south. An
active pattern sets up Thursday into the weekend with showers
and thunderstorms possible with increasing humidity levels.
Rainfall amounts will vary based on where any convection
occurs. The most widespread potential rainfall is expected
Thursday and Saturday.

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


Aly watches/warnings/advisories...
New York...none.


near term...kl/bgm
short term...kl

National Weather Service Glossary of Abbreviations