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fxus61 kokx 040135 
afdokx 


Area forecast discussion 
National Weather Service Upton New York 
935 PM EDT Thursday Jul 3 2008 


Synopsis... 
a cold front will move into the area tonight...and remain in the 
vicinity through the weekend. Waves of low pressure will develop 
and move east along this front causing periods of showers and 
thunderstorms through the Holiday weekend. 


&& 


Near term /until 6 am Friday morning/... 
with the loss of heating and the short wave weakening as it moves 
into the area showers and thunderstorms have become more 
scattered. Also the threat of stronger to severe thunderstorms has 
ended with less instability. Layer moisture increases and low 
level Theta-E...warm air advection will sustain a few showers and 
possible thunderstorms through much of the night. Have updated the weather 
grids for the rest of the evening. Rest of the forecast is on 
track. 


Surface cold front from the Massachusetts-New Hampshire-Vermont 
border into north central Pennsylvania will move into the area 
around midnight and then become nearly stationary. 


As for temperatures...followed MOS blend...with readings above normal in 
SW flow. 


&& 


Short term /6 am Friday morning through Sunday/... 
just enough low level ridging to push front just to our south 
early Friday. GFS still appears to be an outlier with regard to the 
amount of drying that occurs behind the front. As such...more sun 
and warmer temperatures the result. Will lean toward other model 
solutions...and add more sky cover to database...and lower temperatures 
from mav output a tad. 


Then steering flow remains parallel to surface front...and the front 
will remain hung up in the local vicinity. In the 
meantime...precipitation water content increases and remains in the 1 1/2 
to 2 inch range. Middle and upper level impulses move along middle and 
upper level SW flow. Any impulse will be enough to trigger 
showers and thunderstorms at any time. It appears deepest moisture ahead 
of next shortwave will result in highest rain probabilities Friday 
night and Saturday. However...convective threat remains through 
Sunday. 


Plenty of cloud cover will put a lid on maximum heating Sat and 
Sunday...and daytime temperatures will run a few degrees below 
normal. Muggy conditions persist...and patchy fog a possibility at 
night...although not enough to affect public forecast. 


&& 


Long term /Sunday night through Thursday/... 
an active and unsettled weather pattern will remain in place through 
the long term period. Low pressure will pass north of the area by sun 
evening...allowing a warm front to pass north of the region Sun 
night. Bermuda high pressure then sets up offshore...and deep southwest 
flow will allow a very warm and humid airmass to overspread the 
region with highs in the upper 80s to around 90 and dewpoints in the 
upper 60s. Diurnally driven convection will result in scattered 
afternoon and evening showers and thunderstorms. A cold front will 
push into the region on Wednesday...resulting in another round of showers 
and thunderstorms. High pressure builds back into the region on Thursday to 
provide slightly cooler and less humid weather. 


&& 


Aviation /02z Friday through Tuesday/... 
a cold front will approach slowly from the northwest during the 
evening and become stationary in the vicinity through the forecast 
period. Showers and isolated thunderstorms will be possible at the 
terminals through about 06z. With the scattered nature and chances 
of hitting any of the terminals low have only included vicinity 
showers. 


The next best chance of showers will be Friday afternoon as next 
short wave moves along the boundary. 


The forecast of ceilings...winds and chances of showers and 
thunderstorms depends on the location of the boundary Friday. 
Behind the front a northeasterly flow will be developing and 
ceilings could become MVFR while to the south winds will be 
southeasterly to south with VFR ceilings. Not a high confidence 
forecast. 


Outlook for 00z Saturday through Tuesday...very unsettled weather 
pattern ahead. Showers and thunderstorms trek from west to east through 
the period along the front. As such...multiple chances for sub 
VFR ceilings and visibilities in showers and thunderstorms. 


&& 


Marine... 
seas at buoy 44025 about 6 1/2 feet with occasional gusts to about 
25 knots...and seas at buoy 44017 about 5 1/2 feet. Will continue 
with the small craft overnight. Weather grids are on track. 


Will not update the marine forecast at this time. 


Southwest winds diminish later this evening and overnight as surface 
front sags across the waters. Small Craft Advisory conditions will 
be dropped first across all Harbor and sound locations. Ocean 
waters will hang in there through the overnight as seas will take 
sometime to subside below 5 foot thresholds. 


Otherwise...front remain in the waters vicinity through the weekend. 
As such...winds will remain rather tranquil. Main concern for 
mariners through the weekend will be the presence of showers and 
thunderstorms. The threat remains through the weekend. In this juicy 
airmass...any shower or thunderstorm will produce heavy rainfall. 


Sun night through Tuesday...persistent south to southwest flow will 
dominate area waters through the period. Seas will gradually build 
during the period... approaching Small Craft Advisory criteria on the ocean waters 
Monday night and Tuesday. There is the potential for a southerly swell to 
once again develop early next week. 


&& 


Hydrology... 
scattered showers and thunderstorms expected through the evening. The 
potential for a brief heavy rainfall exists with any of this 
activity. The storms diminish in coverage and intensity later 
tonight. 


Additional showers and thunderstorms will remain in the forecast through 
the weekend. Good chance for heavy rainfall scattered across the 
region. As such...flash flooding will remain a threat...especially 
Friday night and Saturday. 


&& 


Okx watches/warnings/advisories... 
CT...none. 
New York...none. 
New Jersey...none. 
Marine...Small Craft Advisory until 6 am EDT Friday for anz355. 
Small Craft Advisory until 8 am EDT Friday for anz350-353. 


&& 


$$