Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Buffalo New York
342 PM EDT Tuesday Jul 22 2014
as a cold front approaches the region from the west...the influx
of increasingly humid air will lead to a warm and muggy
night...then to showers and scattered thunderstorms by Wednesday
morning. Cooler and fair weather will follow this cold front for
the remainder of the week.
Near term /through Wednesday/...
surface high pressure centered off the middle Atlantic coast and low
pressure passing north of the Great Lakes will maintain a very
warm and humid southwesterly breeze across the region for the
remainder of the day and through the night. The axis of the upper
ridge will slowly move to the east this evening but will continue
to suppress and convection with a broad region of subsidence.
The influx of warmth and moisture will continue through the evening
and night with overnight lows in the upper 60s to lower 70s across
the region...a muggy and humid night.
Showers and scattered thunderstorms will precede a cold front late
overnight through Wednesday morning. Nam12 and rgem were models of
choice for timing of the precipitation...most of the rainfall will have
crossed the forecast area before noontime...followed shortly
thereafter by the cold front. High dewpoints and 8kft to 10kft depth
of moisture will yield precipitable water values ranging from 1.6 to
1.8 inch and the greatest Omega is within the lower moist layer...
indicating exclusive warm rain process and the potential for some
downpours. The cold front crosses the region during the early
afternoon with much drier air by the end of the day.
High temperatures may recover a couple of degrees in the morning with
readings in the middle to upper 70s.
Short term /Wednesday night through Thursday night/...
latest model cycle continues to depict a faster cold frontal
progression through the local area Wednesday. Forecasted frontal
timing suggesting the best chances for convection will be
Wednesday morning through middle afternoon...possibly lingering
through latitude afternoon across southeast portions of the region.
Unfavorable timing will likely limit severe threat. Low level
anticyclone to build back into the area behind the front Wednesday
night into Thursday to provide dry and cooler conditions through
Thursday night. Enough lingering low level moisture for decent
diurnally driven cloudiness Thursday afternoon with temperatures
holding in the 70s.
Long term /Friday through Tuesday/...
Friday and Saturday look great with high pressure moving slowly from
the Ohio Valley toward the middle Atlantic coast. Expect minimal clouds
aside from any typical morning valley fog. Temperatures should be
slightly below normal on Friday with excellent sleeping weather
overnight /highs in the upper 70s and lows mostly in the
50s...cooler well inland/. By Saturday highs will reach to near
average with lower 80s at lower elevations away from the lake
Sunday and Monday are more in question with the next system
beginning to affect the region. There are a variety of possibilities
with this next system...with a surface low west or south of the
region by Sunday. A middle level trough or even a middle level closed low
will develop over the western lakes by Monday and provide periods of
large scale ascent and deeper moisture as lobes of vorticity move
downstream of the closed low. This looks to be an unsettled period
starting Sunday and going through the first half of next week.
Aviation /18z Tuesday through Sunday/...
expect VFR conditions for the rest of the day and most of the night.
Precipitation preceding a cold front late tonight through Wednesday
morning may result in MVFR ceilings and locally heavy downpours. VFR
conditions return as the front crosses the area during Wednesday
Wednesday...MVFR in showers and thunderstorms during the morning.
Thursday night through Saturday...mainly VFR...save for IFR/MVFR in
patchy southern tier valley fog later each night/early each morning.
Sunday...VFR/MVFR scattered showers.
high pressure along the eastern Seaboard will maintain the light
winds across the lakes and rivers this evening. This area of high
pressure will slip eastward and allow for a cold front to cross the
lakes on Wednesday. Winds will increase in speed ahead of the cold
front tonight...and become southerly. Behind the cold front...waves
2 to 3 feet will be possible on both lakes Wednesday night and into
Thursday. Winds will lessen Thursday afternoon and waves will