922 
fxus61 kctp 050853 
afdctp 


Area forecast discussion 
National Weather Service State College PA 
440 am EDT Sat Jul 5 2008 


Synopsis... 
a wavy front will remain in the vicinity of the Mason-Dixon line 
today. This boundary will slowly lift northward of the region 
on Sunday...as low pressure from the plains tracks north of 
the Great Lakes. 


&& 


Near term /through today/... 
updated probability of precipitation and increased rainfall across the central mountains and 
ncent PA/West Branch region of the susq valley through the middle 
morning hours of today. A well defined upper shortwave and 
associated 80 knots...250 hpa jet maximum lifting NE across central Penn. 
This upper feature and the location of the 925 hpa front near 
Interstate 80 was creating an area of elevated...moderate to heavy 
showers near and to the NE of kunv. The right entrance region of 
this jet maximum will drag across the ncent mountains and middle susq valley 
through 14z...helping to expand the areal coverage of showers over 
the next few hours. A few hour lull in the precipitation is expected fop 
the late morning and early afternoon...before rain showers/thunderstorms and rain develop 
again this afternoon. 


Weighted the forecast more toward the GFS today than NAM...given 
current radar and satellite images. Showers and a few storms 
will be across much of the region today...especially through 
middle afternoon...as another weak wave tracks NE. While the bulk 
of the showers tracked eastward across S PA Friday afternoon... 
a few echoes have been stuck on the higher terrain since this 
after. Have a flood advisory out for Clearfield Colorado...as isolated 
rainfall has been estimated over 3 inches so far. Temperatures today 
will be similar to yesterday...just a shade below normal during 
the day...but above normal at night...given airmass in place. 
First real taste of an extended period of haze this season. 


&& 


Short term /tonight through 6 PM Sunday/... 
more showers and storms tonight into Sunday...as the upper level 
trough moves toward the area. Best chance of rain will be Sunday 
after. 


&& 


Long term /Sunday night through Friday/... 
still some chance on of showers and storms on Monday...then the 
chance of showers and storms decreases by Tuesday. Temperatures slowly warm. 


Subtle upper low overhead to start the period...although flow 
basically zonal except for this initial ripple. West-southwest flow kicks in 
Tuesday and Wednesday ahead of next system...then a decent chance of drier 
conditions by the later half of Thursday...as high pressure with 
lower dewpoints builds southward. 


&& 


Aviation /07z Saturday through Wednesday/... 
meandering quasi-stationary frontal boundary draped west-east near the 
Mason-Dixon line. Isolated showers have formed across parts of 
central PA tonight. 


Expect many locations to see some fog from tonight into Sat am. 
Mainly MVFR conditions will prevail...with some IFR conditions 
possible. For example...jst has been socked in for several 
hours...and should continue to be into early Sat am. 


Expect most areas to be VFR by 12z-14z on Sat...as fog and haze 
Burns off. MDT may hold onto the haze a little longer. 


Areas of MVFR ceilings and visibilities with scattered rain showers and thunderstorms and rain will linger into 
Sunday and possibly Monday...especially across southern and eastern PA...as the 
front gradually washes out. 


Another weak frontal boundary will approach the commonwealth late 
Tuesday or Wednesday...accompanied by an increased chance for rain showers and thunderstorms and rain. 


&& 


Ctp watches/warnings/advisories... 
none. 


&& 


$$ 
Synopsis...Martin 
near term...Martin/Lambert 
short term...Martin 
long term...Martin 
aviation...Martin/evanego