Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Albany New York
955 PM EDT Tuesday Sep 30 2014
mostly cloudy conditions with a few showers are expected into
Wednesday. Dry and mild weather is expected Thursday and Friday. A
potent low pressure system will push a strong cold front across
the region late Friday night and Saturday, bringing widespread
rainfall and the potential for locally gusty winds. Typical Fall
weather is in store for Sunday and Monday.
Near term /through Wednesday/...
as of 945 PM EDT...little in the way of precipitation is currently
occurring. However...areas of light rain and drizzle are
developing across central and southern New England...and are
drifting northwest. We expect some of this rain to reach the
Berkshires...southeast Vermont and northwest CT shortly after midnight...expanding
north and west into the middle Hudson Valley...southeast Catskills...and
possibly into portions of the capital region closer to daybreak.
As such...probability of precipitation have been increased in these areas...with likelies
to the S/E...and chance probability of precipitation extending to the capital region. Min
temperatures should fall into the Lower/Middle 50s in most areas...as clouds
prevail despite some breaks initially.
It still looks like the upper low (which is sparking the
convection farther west) will move to a position over southern New
England by early Wednesday afternoon. This upper low will work
with the low level moisture to spawn areas of light
rain/drizzle...particularly across the Berkshires into northwest
Connecticut where likely probability of precipitation continue on Wednesday...with
chance probability of precipitation across the middle Hudson Valley extending into the Catskills
and capital region. Probability of precipitation decrease as you head further
northwest...becoming negligible as you reach the 'dacks.
Low confidence in the temperature forecasts with the models not
handling the low level moisture (and clouds) very well. In
general...Wednesday will feature coolest temperatures /low-middle
60s/ in south/east areas with some upper 60s to perhaps 70 more
north/west where it will be drier.
Short term /Wednesday night through Thursday night/...
as of 405 PM EDT...conditions will be improving Wednesday night,
at least with the showers coming to an end as the upper low slides
to the east. However, low level clouds will likely persist as the
low level flow remains light easterly. Again, took a blend of
guidance with regard to the clouds impacting temperatures remain.
In general, Thursday will feature highs in the 60s. Overnight lows
both nights won't be too far from normal -- 40s in the cooler
areas to 50s for everyone else.
Long term /Friday through Tuesday/...
as of 405 PM EDT...main weather event is during this period. A
potent low pressure system will swing through mainly on Saturday,
and in it's wake more typical Fall weather will be seen. 12z
guidance in fairly good agreement, so for the most part I took a
blend of GFS and Euro. Daily details below...
Friday: high pressure noses in, so it will be dry. Ridging aloft
means it should also be sunny as it looks like the moist easterly
flow should have moved out of the area. Temperatures above normal,
touching 70f in the warmer valleys
Saturday: precipitation starts coming in late Friday night/first
thing Saturday. Looks like a pretty strong low/middle level jet with
850mb winds 40-50kts. Could be some gusty winds in the higher
terrain and some valleys. Otherwise guidance suggests the system
will be tapping some decent moisture, so a good 8-12 hours of
rain, with some embedded heavier showers is expected. The clouds
and rain will keep temperatures in the 60s. Initial thinking is
that rainfall totals of 1/2 to 3/4 inch are possible.
Sunday: Post frontal conditions with perhaps some gusty
west/northwest winds. Should be fairly cloudy, thanks to lake
effect moisture streaming off Lake Ontario and Erie, though the
farther southeast you go, the more downsloping and better chance
for some sunshine. 850mb temperatures will be falling toward 0c by
late in the day, so fairly strong cold air advection will be
happening. Highs only in the 50s to a few lower 60s in the farther
south/east areas thanks to the warming downslope effects. Sunday
night will be chilly, with the colder areas dropping into the 30s,
but looks like winds will stay up enough to mitigate frost
Monday/tuesday: another system comes into the area. 12z guidance
has more differences, so kept with a more broadbrush forecast for
both days showing chance level probability of precipitation and a good deal of clouds.
Again a blend of guidance for temperatures as well. Seemed like
the best way to go.
Aviation /02z Wednesday through Sunday/...
widespread MVFR ceilings are expected to develop tonight...with some
pockets of IFR ceilings possible...especially at kpsf. Some spotty light rain
or drizzle may also reduce visibilities into the MVFR/IFR range at kpsf
and possibly kpou toward 12z/Wed.
On Wednesday...expect mainly MVFR ceilings to predominate. Visibilities should
range from VFR to occasional MVFR at kpsf/kpou and possibly
kalb in areas of light rain or drizzle...while remaining generally
VFR at kgfl where little if any rain or drizzle is expected at
Winds will be mainly from the east to NE at less than 5 knots through
daybreak...trending into the NE to north on Wednesday at generally 5-10 knots.
Wednesday night: low operational impact. Slight chance of rain.
Thursday: no operational impact. No sig weather.
Thursday night: no operational impact. No sig weather.
Friday: no operational impact. No sig weather.
Friday night: moderate operational impact. Chance of rain showers.
Saturday: high operational impact. Likely rain showers.
Saturday night: moderate operational impact. Chance of rain showers.
Sunday: no operational impact. No sig weather.
a passing upper level low will allow for isolated to scattered showers
tonight into tomorrow. Temperatures will remain slightly above
normal through the remainder of the work week...before a cold
front brings more widespread showers and cooler temperatures for
Relative humidity values look to recover to near 100 percent tonight with
light to calm winds. There will be a continued threat for some
light rain or drizzle...with the best chance across far southern
parts of the area. East to northeast winds will remain below 5 miles per hour.
Relative humidity values will only drop to 60 to 70 percent on Wednesday with
mostly cloudy skies areas of light rain or drizzle...mainly for
southern and eastern parts of the region. Northeast to north winds
will be around 5-15 miles per hour.
no hydrologic related issues are expected through this week.
Any showers overnight and Wednesday will not produce significant
rainfall amounts. Additional rainfall is expected Saturday. Though
rainfall totals will be heavier -- perhaps 3/4" or so --- no
significant responses are expected at this point on area rivers.
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