382 
fxus61 kphi 062017 
afdphi 


Area forecast discussion 
National Weather Service Mount Holly New Jersey 
417 PM EDT Sat Sep 6 2008 


Synopsis... 
Tropical Storm Hanna will rapidly make its way though the area 
this evening and tonight, followed closely by a weak cold front. 
Weak high pressure will build in for late Sunday into Monday, 
before a cold front passes through late Tuesday. High pressure 
will build into the region for much of the upcoming week, before 
another cold front approches by the end of the week into next 
weekend. 


&& 


Near term /through tonight/... 
Tropical Storm Hanna is now making its way into the area. As the 
storm moves through, heavy rainfall will accompany the storm, 
before rapidly tappering off overnight. By sunrise tomorrow, all 
precipitation is expected to be out of the area as the storm races 
off to the northeast. We will continue with the Flood Watch through 
this evening as the heavy rainfall is moving through could cause 
some problems. With precipitable water values over 2.5 inches, some of this 
rainfall will be heavy at times this evening, and come down in a 
very short period of time. Drivers should be alert for high water 
on local roadways during any of these downpours. The Tropical 
Storm Warning, Tropical Storm Wind Warning, and wind advisroy all 
remain in effect. The storm is still producing some strong gusty 
winds as it is moving through the middle-Atlantic, and could give our 
area some strong winds as we go through the late afternoon and 
into the evening hours. Please refer to the latest statements for 
additional information. For the latest updates on Tropical Storm 
Hanna, please refer to the National Hurricane Center at 
www.NHC.NOAA.Gov 


&& 


Short term /Sunday through Monday night/... 
after Tropical Storm Hanna moves through overnight, Sunday should 
provide a fairly nice day. There may be some lingering clouds to 
start the day off, but they should begin to clear our during the 
day. A weak area of high pressure is forecast to build into the 
region late Sunday and remain through Monday. This should prevent 
any chance of precipitation through Monday night. 


&& 


Long term /Tuesday through Saturday/... 
with the ongoing situation related to the remnants of Tropical Storm 
Hanna, there was little change made to the extended period. We once 
again used HPC guidance as a starting point and made only minor 
adjustments. 


A cold front is still expected to sweep through the region Tuesday, 
most likely in the afternoon or early evening, bringing a chance for 
showers and thunderstorms. The front looks to stall well off to our 
south and east. High pressure will build in behind the front and 
persist through Friday. Another disturbance may impact the region as 
we head into the weekend. 


&& 


Aviation... 
we are in the midst of the tropical moisture associated with Hanna. 
MVFR conds prevail but drop to IFR and locally to LIFR in the 
heavier rain. These conditions will continue until the storm moves 
north of our area later this evening. Expect the worst to be over 
by 10 to 11 PM and all precipitation to have ended by 2 am. 
Conditions will improve to VFR by around midnight. Clearing is 
expected after midnight with clouds going to scattered at the taf sites. 
Blustery southeast to east winds will swing around to NE, N, and then northwest 
except for Acy, which is forecast to be just east of the center. 
At Acy, the winds will go from southeast to S to SW and then to west-northwest. 
A speed wind shear is in the tafs, except for our far northwest sites ridge 
and Abe. The shear will also end during the evening hours as the 
storm moves off to the NE. High pressure moving in behind Hanna 
will provide fair weather and VFR conditions Sunday into Tuesday, 
when a frontal system will move in with another possibility of 
showers. 


&& 


Marine... 
winds are increasing ahead of Hanna this afternoon. If the 
current forecast track is correct, Hanna will move across 
southern New Jersey and reach the coast somewhere near Long Beach island. 
This will present a very different scenario depending on whether 
one is north or south of the storm. North of the storm, winds 
will go from southeast to east to NE to north and then northwest. South of the storm, 
they'll go from southeast to S to SW and then to west-northwest. Wind gusts in the 
35 to 45 knots range are expected to peak near 55 knots during the 
evening hours. Seas of 10 to 14 feet on the ocean and surf wave 
heights of 6 to 9 feet will begin to drop off after the storm 
center passes. 


Weak high pressure is expected to build over the region in the wake 
of the storm for Sunday and Monday. Wind speeds and seas will 
continue to subside at that time. A cold front from the northwest 
is slated to arrive on Tuesday with at least scattered additional 
precipitation. Conditions may approach Small Craft Advisory 
criteria in the frontal zone. 


&& 


Rip currents... 
the high rip current risk today, as Hanna approaches, should subside 
somewhat for Sunday into Monday as the storm moves to our northeast 
and farther away from our region. However, swells from Ike may begin 
to arrive about that time. Even if that does not occur, the expected 
northeast fetch might increase rip currents again by Wednesday. 


&& 


Tides and coastal flooding... 
we are extremely fortunate that Hanna is arriving during the neap 
tide cycle. Also, the higher astronomical tides today along the 
ocean-front have already occurred or are currently occurring. 
There is a better coincidence of winds and tides in the bays and the 
tidal Delaware River than on the ocean. It now appears that the 
greatest area of concern will be the upper Delaware Bay where a 
surge of 1 to around 3 feet is expected. This could produce minor 
flooding in some areas. Drainage flooding on the back bays could 
also occur around the time of high tide if heavy rain is also 
occurring. Lastly, minor tidal flooding might persist into Sunday 
along tidal sections of the Delaware River because of the freshwater 
runoff. 




Phi watches/warnings/advisories... 
PA...Flood Watch through late tonight for paz054-055-060>062- 
067>071. 
Tropical Storm Wind Warning until 11 PM EDT this evening for 
paz067>071. 
Wind Advisory until 11 PM EDT this evening for paz054-055- 
060>062. 
New Jersey...Flood Watch through late tonight for njz001-007>010-012>015- 
017>020-022-025>027. 
Tropical Storm Wind Warning until 11 PM EDT this evening for 
njz001-007>010-012-015-017>019. 
Flood Watch until midnight EDT tonight for njz016-021-023-024. 
Tropical Storm Warning for njz013-014-016-020>027. 
Delaware...Flood Watch until midnight EDT tonight for dez001>004. 
Tropical Storm Warning for dez001>004. 
Maryland...Flood Watch until midnight EDT tonight for mdz008-012-015-019- 
020. 
Tropical Storm Warning for mdz008-012-015-019-020. 
Marine...Tropical Storm Warning for anz430-431-450>455-470. 
&& 


$$ 
Synopsis...Robertson 
near term...Robertson 
short term...Robertson 
long term...meola 
aviation...rpw 
marine...rpw 
rip currents...rpw 
tides and coastal flooding...rpw 

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