Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Buffalo New York
552 am EDT Wednesday Jul 23 2014
a cold front will start to cross the region this morning and be
south and east of much of the area by late this afternoon. Humid
air will keep the warm and muggy conditions in place across the
area through the early afternoon. Expect a round of showers and
scattered thunderstorms as the cold front crosses the region from
northwest to southeast today. Following the cold front...expect
dry and cooler conditions with temperatures averaging a bit below
normal through the end of the week.
Near term /through tonight/...
a broken line of convection currently stretches from roughly
Peterborough southwestward across Central Lake Erie. The northern
edge of the line is approaching western sections of the Niagara
Frontier early this morning. The line is currently weakening as it
moves into the area with just mainly showers...and very little in
the way of lightning. Expect this line of showers to make its way
across western and north-central New York this morning...reaching
eastern portions of the area by late this afternoon. Showers and
scattered thunderstorms can be expected. There is the potential
for a few stronger storms later this morning and through this
afternoon mainly east of The Finger lakes region. The cold front
will move through much if not all of the area before peak heating
occurs. This combined with 0-6km shear values of generally around
30kt and cape values of around 500-1000 j/kg...will help to
inhibit the overall severe threat.
Precipitable water values ranging from 1.7 to 1.9 inches 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 /Thursday through Friday night/...
this period will feature sharp ridging developing across The Rockies
and into the northern plains and troughing over northern Ontario and
the Great Lakes. At the surface...high pressure will slowly work its
way southeast through western New York and down across the Ohio
Valley. This will set the stage for dry...but cooler weather to
wrap-up the work week. A good amount of sunshine for Thursday with
some diurnally driven clouds...but a bit more middle and high level
clouds on Friday in advance of a system that will impact the area
this weekend. Thursday looks to be the cooler of the two days with
highs in the lower to middle 70s...rebounding to 75 to 80 by Friday.
Long term /Saturday through Tuesday/...
over the weekend into the start of next week an amplifying East
Coast 500mb trough forecasted by the medium range models will bring
back a threat of some showers and thunderstorms while keeping
temperatures near to a few degrees below average. Quite a bit of
uncertainty is present for saturdays forecast with models not in
alignment on the initial upper low dropping across the Great Lakes.
The 12z GFS is fastest bringing in showers by Saturday afternoon
while other models delay this. Have introduced a slight chance of
showers on Saturday across wny but over all feel the day will end up
Better agreement develops by Sunday into Monday where models shift
several shortwaves through the upper trough with each of these
bringing a threat for showers and thunderstorms. Have featured the
highest probability of precipitation on Monday where the best model alignment is found in
the 500mb pattern with the trough centered across the Great Lakes.
Tuesday the center of the trough looks to be over New York with a
chance of diurnal instability showers. This upper trough will keep
high temperatures limited to the low to middle 70s next week where we
typically would expect near 80.
Aviation /10z Wednesday through Sunday/...
expect increasing clouds from northwest to southeast across the area this morning
ahead of a cold frontal boundary crossing the area today. Showers
and isolated thunderstorms will pick up as the morning wears on.
This may result in localized conditions of lower ceilings and
locally heavy downpours...however the majority of the morning is
likely to remain VFR. After this...VFR/MVFR ceilings are likely to build
behind the front Wednesday afternoon and evening in the northwest flow.
Some of the latest guidance is suggesting that moisture in the lower
and middle levels may remain high into tonight behind the cold
front...especially across the western southern tier. VFR/MVFR
ceilings may hang on here through much of tonight.
Thursday night through Saturday...mainly VFR...except for IFR/MVFR
in patchy southern tier valley fog later each night/early each
Sunday...VFR/MVFR scattered showers.
a cold front will cross the lakes today. Winds will increase in
speed ahead of the cold front through middle morning...and become
southwest. Conditions may briefly approach small craft criteria on
Lake Erie this morning in this flow. 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