186 
fxus61 kphi 161932 
afdphi 


Area forecast discussion 
National Weather Service Mount Holly New Jersey 
332 PM EDT Tuesday Mar 16 2010 


Synopsis... 
low pressure, located well off the middle Atlantic coast this 
afternoon, will continue to move farther out to sea. High pressure 
is forecast to build into our region gradually from the west for 
the period from Wednesday through Saturday. A cold front from the 
west is expected to arrive late on Sunday, with another area of 
high pressure following for the early part of next week. 


&& 


Near term /until 6 am Wednesday morning/... 
at 3:00 PM, the sky over our region was mainly clear and 
temperatures were mostly in the upper 50s and lower 60s. The wind 
was generally from the north at about 10 miles per hour. 


The sky will remain mostly clear for tonight, as high pressure 
tries to nose into our region from the west. It appears as though 
the wind will decouple at most locations. As a result, we are 
anticipating low temperatures mainly in the 30s. 


Even with the saturated ground conditions, there should be enough 
of a temperature dew point spread tonight to preclude the 
development of much fog. We maintained the mention of patchy fog 
in the Poconos and in far northern New Jersey for the sake of 
continuity. Both the NAM and the GFS MOS data suggests a little 
fog at kmpo around daybreak. 


&& 


Short term /6 am Wednesday morning through Friday/... 
the middle level low that was over Texas this afternoon should 
progress to the east, passing off the southeast coast late in the 
week. As the system moves out to sea, it is forecast to remain far 
enough to our south and east as not to have any impact on our 
region. 


High pressure will continue to nose into our region from the 
west. Dry weather conditions and mild daytime temperatures are 
anticipated for Wednesday, Thursday and Friday. The sky should 
remain mostly clear for Wednesday and Thursday, with perhaps some 
high clouds for Thursday night and Friday. 


We favored the high end of the statistical guidance for our 
temperature forecast, based on the performance of the numbers 
during our last stretch of dry weather. 


&& 


Long term /Friday night through Tuesday/... 
high pressure will build to our south on Saturday and move out to 
sea on Sunday. This should keep dry weather for our area through 
Saturday night into early Sunday. An area of low pressure and its 
associated frontal boundary is forecast to approach the area 
Sunday, then move through the area Sunday night. A good chance of 
rain is expected to accompany this frontal boundary Sunday night 
and possibly linger into early Monday morning. High pressure will 
then build in for Tuesday, leading to more dry weather. 
Temperatures in the extended are expected to start off well above 
normal for Saturday and Sunday, then return to normal or below 
normal for early next week behind the frontal passage. 


&& 


Aviation /20z Tuesday through Sunday/... 
the following discussion is for kphl, kpne, kttn, kabe, krdg, 
kilg, kmiv, kacy and surrounding areas. 


North to northeast winds gusting up to 20 knots at a few taf sites 
this afternoon should taper down to the 5 to 10 knots range late this 
afternoon and early evening, then perhaps become light and 
variable during the overnight hours. The few remaining high clouds 
should dissipate after sunset, so mostly clear skies with no visibility 
restrictions anticipated into the morning hours. The only 
exception may be ridge and miv where some ground fog is not out of 
the question, but is not in the taf. VFR conditions also expected 
on Wednesday under mostly clear skies and light winds. 


Outlook... 
high pressure remains mostly in control of our weather through 
Saturday. A sea breeze may develop Wednesday and Thursday 
afternoons and affect some of the eastern terminals. Perhaps of 
some concern is if fog can form at some spots during the early 
morning hours Wednesday and Thursday given the light winds and wet 
ground. Overall though, no significant weather is expected during 
this time frame. 


&& 


Marine... 
seas on the ocean were around 9 feet in the south and 7 feet in 
the north Tuesday afternoon. Even though the low is moving away 
from the area, it will take some time for these seas to drop below 
5 ft, so the Small Craft Advisory will remain in effect through a good part of 
Wednesday night. The ending time of this Small Craft Advisory might be able to be 
shaved off a little if conditions improve faster than expected, 
but there is time for that decision to be made. 


High pressure then gradually builds toward our area through the 
remainder of the week. This will allow the seas to subside more 
along with provide lighter winds. There may be a sea breeze 
circulation that develops Wednesday and Thursday afternoons, which 
would turn the winds onshore nearshore and funnel up Delaware Bay. 
A weak low pressure system may develop off the S.E. Coast 
Wednesday night, but is expected to pass out to sea south of the 
forecast waters on Friday. 


&& 


Hydrology... 
flooding continues on the Passaic, Pompton, Rockaway, Wanaque, 
great Egg Harbor and Maurice rivers and on the North Branch of the 
Rancocas Creek. Please see the latest warnings and statements 
regarding their status, as well as statements regarding the 
Delaware River near Trenton and the Susquehanna River near the 
Conowingo dam. 


&& 


Tides/coastal flooding... 
the coastal Flood Advisory along the coast and Delaware Bay 
remains in effect through 04z Wednesday to cover the high tides 
through this evening. The coastal Flood Advisory remains in effect 
through 10z Wednesday on the tidal portion of the Delaware River 
to account for the high tide early Wednesday morning. The 
continued freshwater runoff will help to keep the water levels 
higher than normal. 


No problems are anticipated along the Chesapeake Bay on the upper 
half of the Eastern Shore. 


&& 


Phi watches/warnings/advisories... 
PA...coastal Flood Advisory until 6 am EDT Wednesday for paz069>071. 
New Jersey...coastal Flood Advisory until midnight EDT tonight for 
njz012>014-020>027. 
Coastal Flood Advisory until 6 am EDT Wednesday for njz016>019. 
Delaware...coastal Flood Advisory until midnight EDT tonight for 
dez002>004. 
Coastal Flood Advisory until 6 am EDT Wednesday for dez001. 
Maryland...none. 
Marine...Small Craft Advisory for hazardous seas until 6 am EDT 
Thursday for anz450>455. 


&& 


$$ 


Synopsis...iovino 
near term...iovino 
short term...iovino 
long term...Robertson 
aviation...miketta 
marine...miketta 
hydrology...miketta 
tides/coastal flooding...miketta