Area Forecast Discussion
Issued by NWS State College, PA-- Remove Highlighting --
-- Discussion containing changed information from previous version are highlighted. --
FXUS61 KCTP 262326
Area Forecast Discussion
National Weather Service State College PA
726 PM EDT THU MAY 26 2016
A ridge of high pressure will set up shop over the western
Atlantic for the next several days bringing warm and increasingly
humid conditions to the region into the holiday weekend.
Cooler and showery weather may arrive for Memorial Day.
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
Last visuals show what little convection we had is diminishing
pretty quickly now that the sun is going down. Made some near term
tweaks to lower pops overall to fit radar trends as well as near
term high res guidance.
Lingering broken mid clouds for much of the overnight should
prevent anything more than than thin fog from forming. Should
there be a few spots that clear after seeing a shower, then
locally lower visibilities could prevail for a few hours until
just after sunrise.
Mins tonight will feel mid-summerlike in the 60s.
.SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/...
CAPE surges to much higher values than what we had today
(Thursday)as heights build aloft and drier air advects east into
the region AOA 6 kft agl.
Terrain and areas of enhanced sfc heating/weak sfc troughing will
likely be the primary trigger for potentially strong pulse
convection Friday afternoon/evening. Therefore...generic chc pops
will be followed with no specification as to which location will
see the greatest threat for the sct SHRA/TSRA.
What rain does fall could be heavy with almost zero storm motion
and PWATs will still be above 1 inch.
Partly cloudy skies...light wind and moderately high dewpoints Friday
night will lead to another mild night with the potential for light
fog late. Mins in the low-mid 60s will be common.
.LONG TERM /SATURDAY THROUGH THURSDAY/...
Summertime upper level ridge over the Mid Atlantic and Northeast
states is forecast to peak around 29/00z with above normal
heights returning to normal by early next week. Temperatures
should follow a similar trajectory with maxT departures of
+10-15F on Saturday /within 3-5 degrees of daily records/ before
trending modestly lower/toward climatology into the first week of
June. The tropical disturbance /Invest AL912016/ approaching the
Southeast U.S. coast will add additional moisture to an already
humid/unstable airmass in place through Memorial day weekend.
Widely scattered, diurnal convection remains probable Saturday
afternoon/evening with initiation likely triggering along the
Allegheny spine before drifting east. Some interaction between the
tropical disturbance and mid latitude trough crossing the Central
Appalachians likely favors the greatest pcpn risk/potential pcpn
coverage on Memorial Day (Monday) with a decreasing chance for
rain into Tuesday. The 26/12z deterministic and ensemble guidance
are in broad agreement in a dry period of weather from Tuesday
into Wednesday before pcpn risk gradually increases into the
second half of next week. Heights are forecast to rise a bit
around the end of the period before the large scale pattern
slowly shifts toward a western ridge/eastern trough configuration
by June 6th as depicted by the 26/12z NAEFS and 26/00z ECENS.
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
High pressure over the region will result in widespread vfr conds
with just a 6-10 kt south-southwesterly breeze continuing through
late this afternoon. Gusts in the mid to upper teens will occur
acrs the nrn and wrn mtns.
An approaching weak upper lvl disturbance and subtle sfc trough,
combined with an increasingly moist ssw flow, will produce sct
shra/tsra during the aftn and early evening. Although vfr conds
will predominate, a brief vis reduction is possible associated
with a passing shra/tsra.
Widely sctd evening shra/isolated tsra should become confined to
taf sites kmdt and klns this evening before tapering off, as the
disturbance passes east of the region.
The focus will then shift to the potential of patchy late night
fog under light and variable wind...especially in spots that
receive rain this aftn/evening. A moist swrly flow ascending the
mtns could also result in ifr cigs at KBFD late tonight, as latest
mdl soundings and SREF prob data suggest.
Fri and Saturday...Early am low cigs possible. Isold pm tsra
Sat-Mon...Isold pm tsra impacts possible.
NEAR TERM...La Corte/Lambert