Weather

724 
fxus61 kaly 281958 
afdaly 


Area forecast discussion 
National Weather Service Albany New York 
358 PM EDT Thursday Aug 28 2008 


Synopsis... 
the remnants of Tropical Storm Fay and a surface cold front will 
move across the region through the first half of the Holiday 
weekend. However...moisture will be less concentrated and rainfall 
amounts are expected to be light throughout the region. High 
pressure returns to the region for the second half of the Holiday 
weekend with cool temperatures and comfortable humidity levels. 


&& 


Near term /until 6 am Friday morning/... 
remnants of Fay continue to inch east...as strong upper low 
offshore provides downstream strong upper confluence...anchoring 
strong low level ridge in the northeastern U.S. Keeping low levels 
dry. Light rain in western New York/PA continues to inch east...and will 
eventually spread through the northeast U.S. In weakened form. 


Upper low offshore will retreat north and northeast tonight and 
tomorrow...allowing moisture to slowly spread from Ohio Valley and 
western New York/PA through tonight. Middle and upper level moisture will 
spread east first...so just some sprinkles and isolated showers 
affecting western areas before sunrise. Clouds will affect all 
areas by sunrise...but some partly cloudy sky this evening could 
allow temperatures to cool near dew point levels along and east of 
the Hudson Valley...resulting in cooler minimum temperatures and 
some patchy dense fog. So...around 50 cooler spots to middle to upper 
50s warmer spots. 


&& 


Short term /6 am Friday morning through Sunday/... 
low level ridging will weaken and retreat north and east in 
response to the weakening downstream upper ridging as upper low 
continues to move out. Scattered showers will expand across the 
region through the day tomorrow...but light amounts...as very 
little forcing. Remnants of tropical system...though...so even 
with weak forcing...enough moisture so that many areas will see 
measurable rain late Friday through Friday night...lingering in 
eastern areas through Saturday morning. With the cloud cover and 
scattered showers Friday...highs in the lower to middle 70s...cooler 
in mountains. 


Boundary layer wind shift...and boundary layer cooling takes place 
providing some slightly enhanced forcing Friday night and Saturday 
also supporting measurable rain. Upper level impulse dives 
southeast out of Canada and eventually strengthening offshore... 
potentially becoming another upper cut-off low. With at least 
morning cloudiness and scattered showers...some clearing through 
the afternoon in central and western areas...highs Saturday in the 
middle/upper 70s. Surface winds will shift to northwest once upper 
system and surface cold front exit. 


Some cold advection Saturday night...and some low level drying. 
Based on strengthening of upper system as it heads offshore...and 
strengthening downstream upper confluence...guidance may be 
underdoing the cold advection Saturday night and Sunday. Went on 
cooler side of guidance for Saturday night and Sunday...with lows 
in the 50s Saturday night...and highs in 70s to lower 80s Sunday. 


&& 


Long term /Sunday night through Thursday/... 
continued high pressure with sunny skies will dominate the extended 
period. Models not showing much change with ridge over the eastern 
third of the country. Temperatures will be above normal with maximum 
temperatures in the low to middle 80s in the valleys and upper 70s in the 
higher terrain. Min temperatures will start in the middle 50s in the valleys 
and upper 40s in the higher terrain. By the end of the period...min 
temperatures will be around 60 in the valleys and low to middle 50s in the 
higher terrain. 


The next chance for precipitation will be Thursday into Thursday night...as 
an upper low sits just northwest of James Bay with the accompanying 
cold front approaching from the Great Lakes. 


&& 


Aviation /19z Thursday through Tuesday/... 
high level clouds due to the lingering moisture from what was once 
ts Fay will continue to filter over the region through the afternoon and 
into the overnight period. Any precipitation should remain well enough to 
the south and west to not be a problem for the Hudson Valley 
terminals. With the higher dewpoint air advecting in and light 
winds...fog may be a problem tonight...but mainly at or near bodies 
of water. This could drop kgfl down to IFR for the second half of 
the night...but kalb and kpou likely won't go any worse than a brief 
period of MVFR fog for just prior to sunrise. After sunrise 
Friday...any fog should dissipate...returning flying conditions to 
VFR...but a broken middle level deck will continue through the morning 
hours. 


Outlook... 
Friday PM...VFR...slgt chance of rain showers west of the Hudson. 
Friday night-Sat...VFR-MVFR...chc of shra/tsra. 
Sat night-Mon...VFR...no sig weather. 


&& 


Fire weather... 
remnant moisture from Tropical Storm Fay and a surface cold front 
will move across the region through the first half of this Holiday 
weekend. Rainfall amounts are expected to be light though and 
likely be confined to the higher elevations. 


Relative humidities tonight will climb to above 90 percent and drop 
back to between 55 and 65 percent...higher values into the higher 
elevations. 


Winds will be generally from the south at less than 10 miles per hour through 
Friday. The keetch Byram drought index for the region is generally 
less than 300...slightly higher into the Catskills...middle Hudson 
Valley and northwest Connecticut. 


&& 


Hydrology... 
current United States geological survey /USGS/ streamflow condition 
maps from today show that stream flows are near normal in our New 
York and southern Vermont counties. Streamflows are normal across 
Berkshire County Massachusetts and Litchfield County Connecticut. 
USGS ground water monitoring Wells show ground water levels are near 
to above normal almost everywhere. The exceptions are one well in 
Saratoga County New York and one well in Dutchess County New York which show 
below normal levels. 


Dry weather is expected to continue through tonight so streamflows 
will continue to recede into Friday. The next chance for rain is on 
Friday and Saturday as the remnants of Fay interact with a cold 
front. At this time only scattered light rain showers are 
forecast...so not much change in stream levels is expected. Dry 
weather will return on Sunday and continue into the beginning days 
of September. 


For details on the rivers...please visit the advanced hydrologic 
prediction service /ahps/ graphs on our website. 


&& 


Aly watches/warnings/advisories... 
CT...none. 
New York...none. 
Massachusetts...none. 
Vermont...none. 


&& 


$$ 
Synopsis...bgm 
near term...NAS 
short term...NAS 
long term...kgs 
aviation...bjf 
fire weather...bgm/NAS 
hydrology...bgm 

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