Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

Area forecast discussion 
National Weather Service State College PA
235 am EDT sun Jul 5 2015

Synopsis...
a ridge of high pressure will drift slowly southeast across Pennsylvania
today. This weather feature will bring dry and warmer conditions
for the second half of the Holiday weekend.

Warm and humid conditions will move back into Pennsylvania early
next week with several opportunities for showers and
thunderstorms.

&&

Near term /until 8 am this morning/...
early morning 11-3.9u loop showing areas of low clouds/fog forming
under the east/west surface ridge that was stretched across northern Penn.
T/dew point spreads across much of central and northern Penn were 0-2 degree f.

Less fog was noted across the southern tier of the state...where
lingering low clouds were present...topped by cirrus streaming NE
from the Ohio River valley. T/dew point spreads across southern Penn at 05z
were still several degree f in many locations.

Expect the fog to get locally dense throughout the deeper river
valleys of central and northern Penn during the middle morning hours.

Will monitor for possible need of a dense fog advisory late
tonight.

Lows early this morning will vary from the chilly upper 40s
across the northwest mountains...to around 60f across the southern valleys.

&&

Short term /8 am this morning through 6 PM Monday/...
morning fog should burn off to mostly sunny skies by 13-14z...beneath
surface high. Ens mean 800 mb temperatures near 15c imply potential maximum temperatures well
into the 80s...but will temper the warm up just a bit based on wet
ground and potential of smoke from Canadian Forest fires dimming
the sunshine a bit. Early evening visible loop showed expansive smoke
plume over the Great Lakes and pushing toward PA.

&&

Long term /Monday night through Saturday/...
not a lot of change to the longer term grids.

Interesting Fourth of July here...one can see a nice circulation
center off the coast now...see visible satellite loop. Some spots
had over 2 inches of rain since yesterday evening...see pns.

Anyway...still looking a nice day on Sunday. Some high clouds will
work in late...with some chance of a shower by Monday morning
across the SW. Most likely there will be some smoke aloft again.
This was the case at times this past week. Can see some smoke on
the visible satellite loop today.

Did up temperatures some Monday across the north. Also did up probability of precipitation
up some late Monday into Tuesday. Models still want to bring moisture
back to the north later in the day. Highest probability of precipitation late Monday into
early Tuesday.

Cold front across the lower lakes may just fall apart later in the
week. Clue to forecast may be the 00z 7/4 ec run. This run shows
flatter flow at 500 mb later in the week...compared to the 7/3 12z
ec run and other models. Main change for now was to edge probability of precipitation
down later in the week...edge maximum temperatures up some...and lower min
temperatures some. Did not want to go too high with probability of precipitation...models may
have convective feedback issues. At the same time...have to look
at how much rain we got earlier today with a weak system.

Hope all have a good Fourth of July. Was on the cool side last
4th of July...but dry and sunny.

&&

Aviation /06z Sunday through Thursday/...
areas of fog and low stratus will impact several terminals across
central PA airspace early this morning with sub-VFR conditions.
Some local visbys and ceilings will be at or below airfield mins. The
fog and low clouds should dissipate by 14z giving way to high
cirrus veil increasing from the short wave and VFR flying for the rest
of the day.

A closed middle level system will lift northeast from the Tennessee Valley
tonight into the central Appalachians before shearing out over
the northern middle Atlantic Monday into Tuesday. An increasingly moist
south to southeast low level flow in advance of this system will
likely bring low VFR to MVFR ceilings into the airspace along with rain showers
and isolated thunderstorms Monday into Monday night. A cold front should
bring another round of rain showers/thunderstorms to the area on Tuesday into
Wednesday. The front is forecast to stall out near the PA/Maryland border
which will allow for additional opportunities for precipitation through the
end of the week.

Outlook...

Wed-Thu...VFR/MVFR with chance of showers/PM thunderstorms.

&&

Ctp watches/warnings/advisories...
none.

&&

$$
Synopsis...Fitzgerald/Lambert
near term...Fitzgerald/Lambert
short term...Fitzgerald/la corte
long term...Martin
aviation...steinbugl

National Weather Service Glossary of Abbreviations