Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Albany New York
1001 am EDT Wednesday Jul 30 2014
disturbances will move over the region about a large low in the
upper levels of the atmosphere. One today will generate widely
scattered showers and thunderstorms mainly to the north and west of
the capital region this afternoon. A stronger one will produce more
numerous showers and thunderstorms by Thursday afternoon. Unsettled
weather is expected to continue through the upcoming weekend.
Near term /until 6 PM this evening/...
as of 1000 am EDT...still dealing with a good deal of middle level
clouds across our region as moisture remains trapped in this layer.
A look at the 12z aly radiosonde observation indicated moisture...trapped underneath a
The cap looks to weaken by late in the day...as a disturbance noted
over Michigan will cool the middle level column. This disturbance could spark
some widespread scattered showers and thunderstorms. Since this
disturbance looks to lift northwest and weaken...the best forcing
GOES to the north and west of the capital region.
We will continue to omit probability of precipitation from the capital region and points
southeast but there could be a few sprinkles.
We expect the clouds to break up some (already were here at our
office). Therefore...based on the latest radiosonde observation we will leave high
So...for the rest of today...look for an initial decrease in
clouds...then the possibility of shower or thunderstorm mainly north
and west of the capital region this afternoon as lots of cumulus
develops. Otherwise it will be mainly dry with afternoon highs 75-80
in the valleys...upper 60s to middle 70s higher terrain. These values
will be several degrees below normal.
Short term /6 PM this evening through Friday night/...
any lingering convection will diminish with loss of daytime heating
and the passage of the short wave this evening. More widespread
convection is expected Thursday as a stronger short wave rotates
about the upper low. This piece of energy will cause the upper
low to also shift southward. Guidance is in agreement with the
timing of this short wave and has it moving over the Great Lakes
region late tonight/early Thursday morning and off to our
northeast during the afternoon. So the best chances for convection
will be during the morning into the early afternoon hours and
especially to the northwest of the capital district. It will be
cool with highs 5 to 10 degrees below normal.
With the passage of this short wave a deep southwesterly flow will
develop for Friday as the low begins to lifts northward and weaken.
This will result in a warmer day...highs in the middle 70s to lower
80s...along with an increase in dew points/humidity levels. With
the heating of the day can not rule the threat for isolated to
scattered showers/thunderstorms especially during the afternoon.
Long term /Saturday through Tuesday/...
an unsettled weather pattern is expected through much of the
extended period. The general setup through the long term will
feature a longwave upper level trough over the eastern Continental U.S....with
the trough axis situated to the west of our area over the Great
Lakes and Ohio Valley...and a strong ridge situated east of the area
over the western Atlantic. The result will be a persistently moist
S-SW flow of air over the region.
Precipitable water values will be rising over the area over the weekend...with
central/southern areas having values between 1.50-1.90 inches by
late Sunday. With a nearby stationary surface boundary located just
south and east of the area...there will be the threat for showers
and thunderstorms each day over the weekend...mainly in the afternoon and
evening hours. Any shower/thunderstorm will be capable of producing heavy
downpours. Thunder may not be overly widespread...due to limited
instability thanks to all the cloud cover. Temperatures will be held down
somewhat due to clouds/possible precipitation....with maximum temperatures in the 70s
to near 80...and lows in the middle 50s to low 60s.
The stationary front will remain situated just off the eastern
Seaboard for Mon/Tuesday...which will keep the threat for showers
and isolated thunderstorms in the forecast. Eventually...the trough
to our west will start to weaken...and the upper level flow will
start to become more zonal towards middle week...as another cold front
moves towards the area from the northwest. Eventually...this front
will clear our area...and allowing for humidity levels to decrease
somewhat. While the threat for showers/storms will continue through
the middle week period...this slight chance in the upper level pattern
may allow temperatures to warm up by a few degrees...with low 80s for
valley areas...and overnight lows in the 60s...by Tuesday.
Aviation /14z Wednesday through Sunday/...
as of 1130z...VFR conditions were currently in place at all
terminals with broken-overcast ceilings at 7-9 kft and nearly calm winds. These
clouds will gradually decrease over the next few hours as a weak
upper level disturbance swinging around the main trough over
southern Canada moves across the area.
Although there will be a period of just scattered clouds by later this
morning...diurnal cumulus/stratocu at 5-7 kft will develop...allowing for
broken ceilings to return to most sites by the early to middle afternoon hours.
There is a slight chance of a brief light rain shower...but coverage
looks too small to include in the taf at this time. S-SW winds will
be light...generally around 5 kts.
Broken ceilings look to continue right into tonight. These clouds in place
will prevent any radiational fog from occurring...with continued VFR
conditions and light to calm winds.
Thursday night: no operational impact. No sig weather.
Friday-Sun: moderate operational impact. Chance of rain showers...tsra.
disturbances will move over the region about a large low in the
upper levels of the atmosphere. Isolated to scattered showers and
thunderstorms are expected mainly during the afternoon hours today
and Thursday. The activity will be more widespread on Thursday due
to a stronger disturbance. Unsettled weather is expected to continue
through the upcoming weekend.
the weather will be unsettled through the weekend with chances
for showers and thunderstorms mainly during the afternoon hours as
the region remains under the influence of a large upper level low
over eastern Canada. This low will wobble over eastern Canada as
short waves rotate about it and will move north and weak as we
head into the weekend.
Precipitable water values will increase especially over the
weekend so storms will be capable of heavy downpours.
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.