Scientific Forecaster Discussion
fxus61 kaly 221031
Area forecast discussion
National Weather Service Albany New York
631 am EDT Fri Jun 22 2018
high pressure will be near New England today. Clouds will
increase ahead of a warm front tonight with showers moving in
for Saturday. A low pressure system approaching from the eastern
Great Lakes region will continue the threat of showers with
isolated thunderstorms Saturday night, as a cold front will keep
the threat of showers and thunderstorms going to close the
Near term /until 6 PM this evening/...
as of 622 am EDT...high pressure will be over northern New
England this morning, and then drift offshore during the
afternoon. It will be a delightful partly to mostly sunny day
with comfortable humidity levels. After a cool start with temps
in the 40s and 50s (a few 30s over the Adirondack park), temps
will rebound to seasonal normals. Some high clouds continue to
be over the south/southwest extreme of the forecast area based
on the observations and 10.35 micron clean infrared GOES-16 loop this
Some mid and high clouds will continue to increase south and
west of the capital region, as a closed h500 low embedded in a
mid and upper level trough moves over the Midwest. These clouds
will advance ahead of warm front over the Ohio Valley and mid
Atlantic states, as well as a secondary coastal wave near the
Carolinas. These high clouds could keep temps down a couple of
degrees over the eastern Catskills, Mid Hudson valley and northwest CT,
but we tended to lean towards the warmer European model (ecmwf) MOS and GFS MOS
values with highs in the upper 70s to lower 80s in the valleys
and upper 60s to mid 70s over the higher terrain.
Short term /6 PM this evening through Sunday/...
tonight...the mid and upper level riding weakens over the
northeast with the mid and upper level flow becoming
southwesterly ahead of the upper trough. Clouds continue to
increase, thicken and lower from the south and west. Some weak
isentropic lift well in advance the warm front will start to
saturate the column with spotty showers or light rain impacting
locations south and west of the capital region. Lows will be
milder than this morning with mainly 50s with a few upper 40s
in the southern Adirondacks.
Saturday...a cool, gray, and wet start of the weekend is likely
to occur with an mid and upper level trough moving over the
Great Lakes region and Midwest. In the southwest flow, moisture
convergence increases ahead of the sfc wave. Periods of showers
will start to overspread the entire forecast area by the lunch
time hour. The guidance is variable with the the European model (ecmwf)/CMC
having the strong isentropic lift and dynamics enhancing the
rainfall over the southern half of the forecast area, whereas
the NAM is over the northern tier. We tended to enhance the
rainfall to categorical values over the east facing slopes of
the Catskills and Adirondacks with the east/southeast boundary layer
flows. A few thunderstorms could pop up in the mid to late PM
with the showalter stability indices dipping below zero. We
trended the Max temps down more towards a blend of the
GFS/NAM/ECMWF guidance with highs only in the mid to upper 60s
over the valley areas, and upper 50s to lower 60s over the mtns.
Saturday night...weak elevated instability will still be around
in the evening, and decent moisture convergence occurs ahead of
the warm front and the weak sfc wave with the upper low that
turns neutral to negatively tilted. We tapered the showers to
chance or slight chance after midnight, as a pseudo warm sector
sets up over the forecast area. Min temps will not drop off too
much with lows not far off from saturdays highs with mid 50s to
Sunday...a more humid air mass will be over the region with sfc
dewpts in the upper 50s to mid 60s. Another short-wave and a
cold front will move south/southeast towards the region. Cloud
cover may be a problem limiting instability north and west of
Albany, but there are some trends for breaks in the clouds from
the capital region south and east. Better instability may
materialize with the GFS now showing sbcapes of 1000-1500 j/kg
across the southern zones with increasing shear. Some strong
thunderstorms may occur if this magnitude of instability is
realized. We placed a chance of thunderstorms across the
forecast area, especially in the afternoon with likely showers.
Highs will be closer to seasonal norms compared to
Saturday...with mid 70s to lower 80s from the capital region,
upper Hudson Valley, and Bennington, Vermont south and east, and mid
60s to lowers 70s north and west.
Long term /Sunday night through Thursday/...
for Sunday night...expect showers to linger as a secondary cold
front crosses the forecast area. While additional precipitation
amounts will not be that great, an additional tenth of an inch
or so of rain may fall. Lows Sunday night will be in the upper 40s
to mid 60s.
Dry weather is expected Monday through Tuesday night as high
pressure builds southeast from the upper Great Lakes Monday morning
settling across our region on Tuesday and moving just off the
eastern Seaboard by Wednesday. Highs on Monday will range from the
upper 60s to upper 70s, with lows Monday night in the upper 40s to
mid 50s. Highs on Tuesday will be in the 70s to around 80 with
lows Tuesday night generally in the 50s.
For Wednesday clouds will be increasing along with an increasing
chance of showers as low pressure tracks eastward from the upper
Great Lakes accompanied by a vigorous upper level trough. Clouds and
the threat of showers and thunderstorms will linger Wednesday
night into Thursday until the upper level trough passes east of the
area. Highs on Wednesday from the upper 70s to mid 80s. Lows
Wednesday night will be in the upper 50s to mid 60s with highs on
Thursday in the mid 70s to mid 80s.
Aviation /12z Friday through Tuesday/...
VFR conditions expected through the taf period /12z Saturday/
as high pressure moves across New England and then out to sea.
Clouds will increase today as low pressure approaches from the
Ohio Valley, and mid- level ceilings are forecast at kpou and
kpsf this by mid afternoon. A rain shower is possible at kpou
after 06z Saturday, but low chance so only vcsh in kpou taf for
Light and variable winds this morning will become southeast at
6-10 kts by this afternoon and continue tonight.
Saturday night: moderate operational impact. Likely rain showers...slight
chc thunderstorms and rain.
Sunday: high operational impact. Likely rain showers...chance thunderstorms and rain.
Sunday night: moderate operational impact. Chance of rain showers.
Monday: low operational impact. Slight chance of rain showers.
Monday night to tuesday: no operational impact. No sig weather.
high pressure will be near New York and New England
today, and then drift offshore tonight. A low pressure system
and a warm front will bring showers and isolated thunderstorms
to the region Saturday into Saturday night. A cold front will
focus some scattered showers and thunderstorms on Sunday.
The relative humidity values will lower to 30 to 45 percent this afternoon, and
then increase to 80 to 100 percent tonight. In the wetting
rainfall on Saturday the relative humidity values will remain elevated at 65 to
The winds will be light today from the southeast to south at
less than 10 mph. East to southeast winds will persist Friday
night into Saturday at 5 to 15 mph.
A widespread soaking rainfall Saturday through Sunday will
likely occur with the periods of showers and isolated to
no Hydro problems are expected over the next week. Most of the
entire Hydro service area /hsa/ is under abnormally dry
conditions according to the latest US drought monitor.
A dry air mass will be over the hsa until Saturday morning.
There is a high likelihood of widespread rainfall Saturday into
Sunday night with basin average rainfall amounts of a half an
inch to an inch, though locally higher amounts are possible with
Minimal rises are expected on the waterways. Dry weather
returns Monday afternoon into the midweek.
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.