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Area Forecast Discussion (AFD)

Issued by State College, PA (CTP)

                            
190 
FXUS61 KCTP 252335
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
735 PM EDT Mon Mar 25 2019

.SYNOPSIS...

Low pressure will track off the Mid Atlantic coast overnight.
Canadian high pressure and associated dry air mass will settle 
south across the area during midweek. A cold front is then 
likely to push southeast across the region next weekend.

&&

.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...

Radar shows the rain, with wet snow on the ridges, is dwindling
rapidly as the surface low moves through southern VA and starts
to redevelop along the NC/VA coast.

We had a couple of reports of wet snow over some of the higher
elevations with about a third of an inch or rain on average over
the southern 1/3 or so of the CWA..

Clearing skies are starting to edge south through the northern
counties, and by midnight or the wee hours of Tuesday, the 
forecast area should be under clear to scattered skies.

Overnight lows will bottom out in the teens and 20s, or some
5-10 deg colder than they should be in late March.

&&

.SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/...
Canadian high pressure will build into the region Tuesday,
accompanied by abundant sunshine and a light northerly breeze.
Mixing down model 850mb temps yields expected max temps ranging
from the upper 30s over the northern mountains, to the mid 40s
across the Susq Valley.

&&

.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
U.S. and Int'l EFS guidance show a strong consensus on waning NW
flow aloft and a large area of sfc high pressure building SE
from the Glakes and over the NE U.S., with the high amplitude 
upper ridge over the Rockies flattening out as it slides east 
across the Plains states. 

This evolution of the sfc and upper pattern will mean mainly dry
weather with a gradual warmup with above, to well above normal 
temps in the 50s to around 60F on Thursday. Generally light 
wind will become southwesterly thursday ahead of a cold front, 
that will slow or stall and string out nearly east to west 
across PA to close out the week and introduce the chance of 
showers Thursday afternoon into Friday. 

The front will retreat back slightly to the north as a warm 
front later Friday and Saturday as the northern stream trough 
races east across SE Canada, and a southern stream upr wave and 
sfc low approaches from the Central Plains and Mid Miss Valley.
We'll see temps soar in the 60s and perhaps top 70F in some of 
the southern valleys both Friday and Sat. 

The best chance for showers comes over the weekend, when east 
coast ridge breaks down and cold front pushes across the state.

U.S. and Euro models diverge early next week with the timing,
amplification and northern extent of influence with respect to a
southern stream wave. For now, will maintain a dry forecast
unless there is appreciable northern deviation from current 
guidance.

&&

.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
Wave well to our south is moving rapidly eastward and the 
precip shield over south central PA is drying up as it slides 
south and east. Precip likely over by 01Z at all terminals. Only
JST is at IFR currently (23Z) but should also be clearing out 
shortly. Massive high pressure and strong subsidence will bring 
clear sky tonight with only a small chc of some fog where it has
rained the most today. The near-zero dewpoints will come in 
rapidly, though, on light but steady north wind. Thus, have not 
mentioned fog in the TAFs at this point. Wind picks up just 
slightly late tonight or Tues AM, but stays from the N. Sfc high
will be overhead Tues night and VFR should hold through Friday.

.Outlook...

Wed...No sig wx.

Thu...Mainly VFR, but SCT SHRA poss NW along WFRONT.

Fri...SHRA N, mainly VFR elsewhere.

Sat...Mainly VFR, but SCT SHRA poss NW as CFRONT nears.

&&

.FIRE WEATHER...
A weak weather system will move south of the state today through 
tonight producing light precipitation, mainly over the southern 
half of the district. Behind this system, a large area of high 
pressure will build across the eastern third of the country 
through mid week. 

***This area of high pressure contains very dry air, with
 dewpoints in the single digits expected today, Tuesday and
 Wednesday across the northern half of the district. Dewpoints in
 the teens are forecast across the southern half on Tuesday and
 Wednesday. This will result in afternoon relative humidity below
 30 percent all three days. Given sufficient mixing, quick drops
 to below 20 percent are possible in some locations.

Winds are expected to remain on the light side /less than 10mph/ during
this period.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$
SYNOPSIS...La Corte/Ceru
NEAR TERM...La Corte/Ceru
SHORT TERM...Fitzgerald/Ceru
LONG TERM...Lambert
AVIATION...Dangelo
FIRE WEATHER...


000
FXUS61 KCTP 252335
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
735 PM EDT Mon Mar 25 2019

.SYNOPSIS...

Low pressure will track off the Mid Atlantic coast overnight.
Canadian high pressure and associated dry air mass will settle 
south across the area during midweek. A cold front is then 
likely to push southeast across the region next weekend.

&&

.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...

Radar shows the rain, with wet snow on the ridges, is dwindling
rapidly as the surface low moves through southern VA and starts
to redevelop along the NC/VA coast.

We had a couple of reports of wet snow over some of the higher
elevations with about a third of an inch or rain on average over
the southern 1/3 or so of the CWA..

Clearing skies are starting to edge south through the northern
counties, and by midnight or the wee hours of Tuesday, the 
forecast area should be under clear to scattered skies.

Overnight lows will bottom out in the teens and 20s, or some
5-10 deg colder than they should be in late March.

&&

.SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/...
Canadian high pressure will build into the region Tuesday,
accompanied by abundant sunshine and a light northerly breeze.
Mixing down model 850mb temps yields expected max temps ranging
from the upper 30s over the northern mountains, to the mid 40s
across the Susq Valley.

&&

.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
U.S. and Int'l EFS guidance show a strong consensus on waning NW
flow aloft and a large area of sfc high pressure building SE
from the Glakes and over the NE U.S., with the high amplitude 
upper ridge over the Rockies flattening out as it slides east 
across the Plains states. 

This evolution of the sfc and upper pattern will mean mainly dry
weather with a gradual warmup with above, to well above normal 
temps in the 50s to around 60F on Thursday. Generally light 
wind will become southwesterly thursday ahead of a cold front, 
that will slow or stall and string out nearly east to west 
across PA to close out the week and introduce the chance of 
showers Thursday afternoon into Friday. 

The front will retreat back slightly to the north as a warm 
front later Friday and Saturday as the northern stream trough 
races east across SE Canada, and a southern stream upr wave and 
sfc low approaches from the Central Plains and Mid Miss Valley.
We'll see temps soar in the 60s and perhaps top 70F in some of 
the southern valleys both Friday and Sat. 

The best chance for showers comes over the weekend, when east 
coast ridge breaks down and cold front pushes across the state.

U.S. and Euro models diverge early next week with the timing,
amplification and northern extent of influence with respect to a
southern stream wave. For now, will maintain a dry forecast
unless there is appreciable northern deviation from current 
guidance.

&&

.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
Wave well to our south is moving rapidly eastward and the 
precip shield over south central PA is drying up as it slides 
south and east. Precip likely over by 01Z at all terminals. Only
JST is at IFR currently (23Z) but should also be clearing out 
shortly. Massive high pressure and strong subsidence will bring 
clear sky tonight with only a small chc of some fog where it has
rained the most today. The near-zero dewpoints will come in 
rapidly, though, on light but steady north wind. Thus, have not 
mentioned fog in the TAFs at this point. Wind picks up just 
slightly late tonight or Tues AM, but stays from the N. Sfc high
will be overhead Tues night and VFR should hold through Friday.

.Outlook...

Wed...No sig wx.

Thu...Mainly VFR, but SCT SHRA poss NW along WFRONT.

Fri...SHRA N, mainly VFR elsewhere.

Sat...Mainly VFR, but SCT SHRA poss NW as CFRONT nears.

&&

.FIRE WEATHER...
A weak weather system will move south of the state today through 
tonight producing light precipitation, mainly over the southern 
half of the district. Behind this system, a large area of high 
pressure will build across the eastern third of the country 
through mid week. 

***This area of high pressure contains very dry air, with
 dewpoints in the single digits expected today, Tuesday and
 Wednesday across the northern half of the district. Dewpoints in
 the teens are forecast across the southern half on Tuesday and
 Wednesday. This will result in afternoon relative humidity below
 30 percent all three days. Given sufficient mixing, quick drops
 to below 20 percent are possible in some locations.

Winds are expected to remain on the light side /less than 10mph/ during
this period.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$
SYNOPSIS...La Corte/Ceru
NEAR TERM...La Corte/Ceru
SHORT TERM...Fitzgerald/Ceru
LONG TERM...Lambert
AVIATION...Dangelo
FIRE WEATHER...