014 
fxus61 kphi 070215 
afdphi 


Area forecast discussion 
National Weather Service Mount Holly New Jersey 
1015 PM EDT Monday Oct 6 2008 


Synopsis... 
high pressure will remain over the region before moving offshore 
Thursday. A low pressure system over central Canada will push a cold 
front across the area Friday as an area of low pressure pushes north 
from the Carolinas. High pressure returns Saturday and hangs around 
through the weekend. A cold front is forecast to cross the region 
Sunday night into Monday. 


&& 


Near term /through Tuesday/... 
skies have cleared across the region where freeze warnings or 
frost advisory in effect and the winds have become calm. Temperatures 
will get down into the lower 30s across the southern Poconos and 
northwestern New Jersey. Some areas will see low to middle 30s just 
to the south of that area. Therefore the frost and freeze 
headlines have remained unchanged. We also added some patchy frost 
for the areas just outside of the advisory region, as temperatures 
in the higher elevations may drop down far enough to produce some 
frost. 


Overall a beautiful,albeit a cold, night is on tap. 


&& 


Short term /Tuesday night/... 
high pressure will remain entrenched over the region bringing clear 
skies for Tuesday into early Wednesday. Highs on Tuesday will be 
in the upper 50s to the upper 60s across the region. 


Cooler temperatures will be on tap for Tuesday night across parts of 
the region with most areas reaching into the upper 30s/lower 40s 
and the interior and northern areas staying in the low to middle 30s. 
Depending on how things pan out tonight, frost/freeze headlines 
may be warranted once again for Tuesday night, especially north 
and west of Philadelphia. 


Wednesday brings mostly clear skies to start with increasing 
clouds throughout the day. Highs will be in the middle 60s to lower 
70s across the region. 


A blend of mav/met temperatures was used throughout the period. 


&& 


Long term /Wednesday through Monday/... 
high pressure pushes offshore Thursday, bringing an end to the dry 
weather of late. A low pressure system over central Canada will push 
a cold front across the area Friday as low pressure pushes north 
from the Carolinas. The front looks to push the other system out to 
sea, but not before it has some kind of impact in the southern 
zones. The European model (ecmwf) is less amplified than the GFS with the Carolina 
low. HPC prefers the European model (ecmwf) throughout the period with the exception 
of this feature and for the most part we have followed suit. The GFS 
tracks the low up through our County Warning Area Friday and Saturday, bringing 
showers to the region. It then is expected to partially clear out 
with only a few stragglers, if any, left behind as we head into 
Sunday. High pressure will build in from the west Sunday and 
Monday. A low pressure develops from he Gulf into the plains 
states Sunday and traverses east, potentially affecting the region 
later Monday or Tuesday. 


With all of the uncertainty in the extended forecast we have carried 
at least slight chance probability of precipitation through Sunday, even though the European model (ecmwf) 
shows dry conditions across the area. Hopefully over the next day 
or two the models will come to a better agreement on the Carolina 
low and then again with what happens with the plains low/Gulf 
moisture. 


Maximum temperatures through period will be above normal with 60s in 
the northern most areas and 70s elsewhere. Lows will be in the 50s 
across the majority of the region. 


We followed HPC, which used the ECMWF, and then blended with a 
bit of the GFS due to the uncertainty previously mentioned. 


&& 


Aviation /02z Tuesday through Saturday/... 
VFR forecast will be continued in the next set of tafs. Actually 
there will be no clouds at all mentioned. There could be a few 
straggling cold air advection SC during the first hour at kacy and kmiv, but they 
will be gone by 01z or 02z. It looks like the cirrus band over West Virginia 
should be shunted south of the taf. The air mass is too fresh to 
support fog. Plus there might be a light north wind through the 
night. A wind change group will be carried on Tuesday morning to 
reflect the backing of the general wind toward the northwest and a last 
wind group was added to show the decoupling of winds at most of our 
taf sites toward sunset. 


Outlook... 
the high will move to the east Wednesday into Thursday allowing for 
a return flow. A storm system may approach the region for the later 
part of the week. However, there is considerable uncertainty with 
this next system. The European model (ecmwf) and GFS have flipped as to who is drier. 
Stay tuned. 


&& 


Marine... 
strong high pressure will drop south into our area during the next 
36 to 48 hours. The pressure gradient between the high to the north 
and low pressure to our southeast will strengthen and peak tonight. 
Winds and seas will increase, but are expected to peak below Small 
Craft Advisory criteria. 


The high will then slide to the east on Wednesday with a return flow 
becoming established. There is a tremendous amount of uncertainty 
with the upcoming storm system late this week. We will go middle of 
the Road between the European model (ecmwf) and GFS. The European model (ecmwf) is much more optimistic 
than the GFS, which would give US gusty winds and high seas late 
Friday into Saturday. 


&& 


Phi watches/warnings/advisories... 
PA...frost advisory from 2 am to 8 am EDT Tuesday for paz060>062. 
Freeze warning from 2 am to 8 am EDT Tuesday for paz054-055. 
New Jersey...frost advisory from 2 am to 8 am EDT Tuesday for njz007-008. 
Freeze warning from 2 am to 8 am EDT Tuesday for njz001. 
Delaware...none. 
Maryland...none. 
Marine...none. 


&& 


$$ 
Synopsis...meola 
near term...meola/eberwine 
short term...meola 
long term...meola 
aviation...gigi/rpw/Heavener 
marine...rpw/Heavener