Area Forecast Discussion
Issued by NWS State College, PA-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
FXUS61 KCTP 251859
Area Forecast Discussion
National Weather Service State College PA
259 PM EDT THU AUG 25 2016
A weather disturbance will bring showers and thunderstorms to
western portions of the area this evening. These storms will
diminish as they more into east later this evening. A seasonally
warm and humid late- summer weather pattern will continue across
Central Pennsylvania into next week.
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
HRRR runs show convection entering nw cwa this evening. A few of
these storms will be quite strong with frequent lightning...gusty
winds and brief heavy downpours accompanying them as the move
east and southeast. Convection will weaken after sunset with loss
of heating...somewhere close to Centre County and points north
south...likely not making it much further east. After convection
diminishes look for another warm and humid night.
.SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/...
Ridging will bring warm temperatures aloft to limit threat of
convection. Slight less surface moisture will make things feel more
comfortable though temperatures will once again top out well
Sfc high will build over the region Friday night, resulting in a
fair and mild night. Will have to watch for the possibility of
patchy valley fog over the northern mtns late.
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
-- Changed Discussion --Medium range guidance is in good agreement in keeping an anomalous ridge
aloft in place over the region into the early days of next week.
This will assure we remain warmer than normal with daytime highs
in the mid to upper 80s, low to mid 90s over southeastern areas,
at least into Tuesday.
By mid week week, weak troughing rippling through southern Canada
and the Great Lakes is made to erode the northern portion of the
northeastern ridge a bit, but only to the extent that upper
heights and temperatures fall back closer to normal values.
The NAEFS and GEFS end up carving out a weak mean trough by the
end of the week, but once again heights and temps are forecast to
be near seasonal norms so it should remain quite pleasant with
the biggest chance being a break in the humidity.
Chances for rain will be generally limited to scattered diurnal convection
each day, but with warm air aloft the chances should remain small
in the absence of well defined forcing. There is a period later
Sunday into Monday morning as we come under the northern edge of
the subtropical ridge and a weak cold front approaches, which
could be the first hints at the development of a more significant
MCS upstream. But with such a strong ridge aloft it`s hard to be
confident at this range.
Main item of difference is the tropical system the ECMWF blows
up over the southeastern Gulf of Mexico early next week that the
GFS doesn`t do much with at all. Both model suites agree with
the northern stream trough mentioned above to be enough to keep
any possible tropical developments well south of the local area.
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.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
Scattered convection this evening across nw portion of area with
improving conditions late evening.
Fri...A.M. restrictions possible; becoming VFR. Isold thunderstorms
possible southern 1/4 airspace in the afternoon.
Sat...Patchy A.M. fog. Otherwise no sig wx expected.
Sun...Isold thunderstorms possible western 1/3 airspace in the
Mon...Isold-sct thunderstorms possible.
LONG TERM...La Corte