122 
fxus62 kmhx 060743 
afdmhx 


Area forecast discussion 
National Weather Service Newport/Morehead City NC 
343 am EDT sun Jul 6 2008 


Synopsis... 
a trough of low pressure in the upper atmosphere with numerous 
disturbances moving through it will remain in place over the 
southeast through Monday. The trough will lift out Monday night. At 
the surface...high pressure off the East Coast will lose its 
influence by the middle of the week as a cold front approaches from 
the northwest. The front is expected to become stationary over 
Virginia by the end of the week then lift north next weekend. 


&& 


Near term /until 6 PM this evening/... 
little change from previous package. Went with likely probability of precipitation across 
the board. Forecast soundings are nearly saturated from the ground 
up in deep southwest flow around the high off the East Coast. 
Precipitable water values today average 2.05 to 2.10 inches. Upper 
trough remaining over the southeast with numerous hard-to-time 
disturbances moving through the flow will provide the trigger for 
showers and thunderstorms at just about any time. Strong divergence 
in the 200-300 mb layer shows very good upper venting for 
convection. 


&& 


Short term /6 PM this evening through Tuesday/... 
above reasoning will continue into tonight and Monday as well...so 
continued likely probability of precipitation. The upper trough will weaken and lift out to 
the northeast Monday night to be replaced by a more zonal flow. 
Still a good amount of low level moisture but dynamics not as strong 
so current chance probability of precipitation look good. 


&& 


Long term /Tuesday night through Saturday/... 
western Atlantic ridge will lose its grip around Wednesday...with a 
front approaching from the northwest. The front is forecast to 
become stationary over Virginia on Friday then lift back north next 
weekend. Overall can expect typical summertime weather...generally 
diurnal convection through the period. Highs generally in the low 
90s/upper 80s...and overnight lows in the low 70s. 


&& 


Aviation /08z Sunday through Thursday/... 
an unsettled period will continue over the terminals the next 
several days as a moist and unstable airmass combines with upper 
level support resulting in scattered showers and thunderstorms across 
the area. In addition the moist low levels in conjunction with 
light winds will allow fog and low clouds to develop over the 
areas that received significant rainfall early this morning and 
again Monday morning. Although much of the time VFR conditions 
will prevail there will be periods of MVFR and local IFR in the 
precipitation and fog. Wind speeds will generally be SW around 10 
to 15 knots during the day with lighter speeds at night and a slight 
diurnal backing of the winds during the afternoon hours. 


A somewhat drier airmass and less favorable forcing will lead to 
less coverage and mainly diurnal convection on Tuesday and Wednesday. 
A prefrontal trough in advance of a cold front will enhance 
precipitation chances on Thursday. 


&& 


Marine... 
moderate SW flow to continue over the area through the forecast 
period with Bermuda high offshore and weak troughing over inland 
areas. Mainly looking at 15 to 20 knots during the afternoon and 
evening hours with a decrease in wind speeds to the 10 to 15 knots 
range overnight into the early morning hours with loss of 
differential heating. Wavewatch is still indicating a period of 
higher seas (5 to 6 ft) occurring late today and tonight. 
However...wave watch is currently running 1-2 feet too high 
across the central and northern waters. The Swan model is 
forecasting 4 foot seas through tonight with 5 feet on Monday. 
Since the wavewatch is currently slightly overdone I will split 
the difference with the Swan and cap seas at 5 feet...just below 
advisory levels. A cold front moving across the NE states 
Wednesday into Thursday will pinch the gradient with winds and 
seas increasing but most likely remaining just below advisory 
levels. 


Looking ahead the ww3 guidance continues to indicate east/southeast swell 
overspreading the area by Tuesday/Jul 08 and continuing through next 
weekend as ts Bertha continues tracking west/northwest towards the western 
Atlantic. Significant uncertainty/model spread exists at this time 
with regards to the track Bertha will take during the beginning of 
next week. Despite track uncertainty there is reasonable 
confidence that the forecast long period swell (2-4 feet/13-15 sec) 
will begin to reach the NC coastal waters by middle week which would 
result in a prolonged period of a higher rip current threat along 
area beaches. 


Rip currents...low threat all beaches for today. 


&& 


Mhx watches/warnings/advisories... 
NC...none. 
Marine...none. 


&& 


$$ 
Synopsis...hsa 
near term...hsa 
short term...hsa 
long term...jbm/hsa 
aviation...jme 
marine...jme