Area Forecast Discussion
Issued by NWS Binghamton, NY
FXUS61 KBGM 010841
Area Forecast Discussion
National Weather Service Binghamton NY
441 AM EDT FRI JUL 1 2016
Scattered showers and thunderstorms are likely today from midday
through evening. Some storms may produce gusty winds and hail,
especially near interstate 81 and areas to the east. We will be
drier and more comfortable Saturday, with dry and warmer weather
Sunday into much of next week.
.NEAR TERM /THROUGH TONIGHT/...
430 AM Update...
The main focus will be on the severe weather threat today
especially across the eastern half of our forecast area. SPC which
placed a marginal risk for severe weather across our far eastern
forecast area yesterday morning, continued the westward trend
later yesterday and again this morning. Now a slight risk for
severe weather is on a line from Towanda to Owego to Syracuse and
points east, with a marginal risk west of this line.
A prefrontal trof looks to be the trigger to get things going
between 15Z and 18Z today, with a cold front keeping shower and
thunder chances going into the early evening. While the threat
for severe weather is similar in aerial extent to the last event
we had (I-81 east again the prime area), a few important parameters
are different and may lead to a greater potential for damaging
winds today. We are not as moist as last time and the NAM seems
the most resonable with dewpoints climbing into the lower to
middle 60s this afternoon at best. The NAM also seems more
resonable with MLCAPES this afternoon between 800 and 1200 J/KG
and I don`t buy the lower CAPE values on the GFS. Despite not
being as moist, we have much steeper lapse rates than the last
event. The steepest lapse rates are from the surface up through
about 700 mb. It is around this level we will have a weak cap late
this morning, but this should be easily broken with the surface
trof and upstream shortwaves providing plenty of lift. While the
lapse rates weaken a bit above 700 mb, they are still quite
decent. The steep lapse rates combined with 0-6 KM bulk shear
values of 35-40 KTS and dry air in the mid levels, points to a
damaging wind threat being the primary concern along with large
hail. Overall low level rotation is pretty weak for much of the
day, with 0-1 KM bulk shears of 10 kts or less, which is not
conducive to a tornado risk. However, SPC does have our extreme
far east in a 5% risk. This is likely do to an increase in low
level shear late in the day in these areas as 0-1 KM bulk shears
increase to around 20 kts. Still high resolution model guidance
combined with the parameter`s mentioned above point to an
evolution of small linear lines developing between 15Z and 18Z
just west of near I-81, then progressing east- southeast. It will
be during this time (18Z and onward) and areas east of I-81, that
our potential for severe weather will be the highest as these
lines try to become longer lived and longer in aerial extent north
to south. The steeper lapse rates also lead me to believe that we
may have more reports of wind and hail than the last go around.
Storm threat clears the far east of 03Z with drier weather
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
430 AM Update...
Behind the storms mentioned above, cooler air will filter into the
area over the weekend. 850 temps around 10C will translate into
highs in the 70s Saturday, and perhaps touch near 80 in the
warmest spots Sunday. All in all a great weekend weatherwise, lets
just hope some of our drier locations in the Finger Lakes can see
some rain today for the farmers!
.LONG TERM /MONDAY THROUGH THURSDAY/...
2 pm Thursday update...
The largely cyclonic pattern aloft this weekend will shift to a more
zonal flow through the week...which will allow the cooler/milder air
to move out and usher in a warmer air mass through the middle of the
week. There is still the potential for a few showers and storms
across the Twin Tiers and NE PA Tuesday as an embedded upper wave
and associated inverted trough track through the mid-Atlantic
region. There is still some uncertainty regarding the nwd extent of
this precip shield...but confidence is decreasing as the latest 12Z
model runs have all shifted the bulk of the precip well to the
south. The one exception is the Canadian model...which still brings
a swath of 1 inch of rain along and south of the NY/PA border. High
pressure builds in across the region into the middle to latter half
of the week. Should remain dry for most of the region with no
significant chances for accumulating rain.
High temperatures will warm from the low to mid 80s early in the
week...into the mid to upper 80s, close to 90 by late in the week.
Lows will warm as well...into the lower/mid 50s on Monday, into the
upper 50s and 60s later in the week.
.AVIATION /08Z FRIDAY THROUGH TUESDAY/...
Clr skies and lgt winds may allow some mvfr fog to form briefly at
ELM this mrng, otrw vfr conds will prevail into the aftn hrs. Cold
fnt will pass thru the area during the aftn and brings shwrs and
isltd tstms that could bring isltd mvfr conds and gusty winds.
Beyond the storms tngt, VFR conds with lgt winds will prevail thru
the end of the TAF pd.
Friday night through Tue...Mainly VFR except for possible predawn
valley fog for KELM after Saturday.