485 
fxus61 kaly 301044 
afdaly 


Area forecast discussion 
National Weather Service Albany New York 
644 am EDT Sat Aug 30 2008 


Synopsis... 
a cold front will move across eastern New York and 
western New England today with scattered showers and isolated 
thunderstorms. High pressure will build in from the Great Lakes 
region Saturday night. The air mass will produce warm and dry 
weather through the Labor Day Holiday. 


&& 


Near term /until 6 PM this evening/... 
a cold front is making steady progress across lakes Erie and 
Ontario this morning with a couple thunderstorms over western New York at 
0700 UTC. The latest ruc40 shows the upper level trough moving 
across Lake Huron and Georgian Bay. We agreed with the short range 
guidance the enough low level convergence with the front should 
allow scattered showers this morning into the early PM. The GFS is 
a little faster with the frontal passage across the northern two thirds 
of the forecast area compared to the NAM. We leaned closer to the GFS 
shear and instability profiles for the afternoon. SBCAPE values of 
250-500 j/kg are possible south and east of the capital region and 
southern Vermont with lifted indices of -1c to -3c. We included isolated thunderstorms and rain showers 
from 1800 UTC-2200 UTC. The winds should shift to the SW/west ahead 
of the front allowing some downsloping to occur before the 
dewpoint boundary breaks through. Maximum temperatures in the u70s to l80s 
will be common in the valleys...with u60s to m70s over the 
hilltowns and mountains we went close to a GFS/NGM blend. 


&& 


Short term /6 PM this evening through Monday/... 
surface high pressure quickly ridges eastward from the Great Lakes 
region Sat night. The h500 cold pool stays over southern Quebec with 
temperatures only falling to -10c at kalb. The weak low level cold air 
advection will occur Sunday morning. Clear skies and calming winds 
will allow some patchy river fog in the upper Hudson Valley /near 
kgfl/...the Mohawk River valley and the CT River Valley east of 
southern Vermont. 


Sunday...h500 heights rapidly rise upstream over the Great Lakes 
region with a strong ridge evolving. Subsidence associated with 
the ridge will yield sunny skies...low humidity levels...and 
slightly above normal maximum temperatures. 


Sunday night...good radiational cooling night with calm winds and 
clear skies with surface high nestled over the NE PA/New York border. We 
went close to the gfsmos mins here. 


Labor Day...the lovely Holiday weekend weather continues surface and 
upper level ridging dominating the northeast. H850 temperatures climb 
close to +13c...with maximum surface temperatures in the lower to middle 80s. We 
will continue to be on the anticyclonic shear side of the upper 
level jet into the middle week with temperatures soaring close to 10 degrees 
above normal for early sept. 


&& 


Long term /Monday night through Friday/... 
models in agreement on the longwave pattern. Amplified pattern with 
trough across the West...Ridge over eastern United States and 
stacked low off the northern New England coast through middle week. 
During the latter part of the week the ridge weakens...the stacked 
low heads northward and the trough shifts eastward. There are 
differences between the models with regards to the short waves 
moving into and through trough as we head into the weekend. Also the 
GFS and European model (ecmwf) track Gustav and Hanna differently...refer to the 
products issued by the National Hurricane Center for details. For 
the upcoming week looking at dry and warm weather with ridge 
dominating through Friday. Tuesday should be the warmest day with 
highs mainly in the middle to upper 80s. The record high for Albany New York 
for September 2nd in 100 degrees set back in 1953. 


&& 


Aviation /12z Saturday through Wednesday/... 
showers are moving across western and northern New York ahead of the 
cold front. Have vicinity showers in tafs to address threat as the 
cold front approaches and moves through. MVFR-IFR conditions across 
area will persist until the frontal passage. Conditions will improve 
to VFR after the frontal passage. Skies will clear this evening 
however conditions will be favorable for the formation of 
radiational fog especially after midnight. Winds...light southerly 
shifting to the west then northwest this afternoon with the frontal 
passage at less than 10 knots becoming light and variable to calm 
this evening. 


Outlook... 
Sat PM-Wed...VFR. No sig weather. 


&& 


Fire weather... 
a cold front will produce scattered showers and isolated 
thunderstorms south of the capital district into the afternoon. 
High pressure will bring fair and dry weather Saturday night 
through Sunday. 


Relative humidity values will fall to 50 to 70 percent this afternoon. They will 
quickly recover to near 100 percent Sunday morning. The relative humidity values 
will plummet to 30 to 50 percent Sunday afternoon. 


The winds today will shift from the south at 5 to 10 miles per hour to the 
west or northwest at 5 to 10 miles per hour in the afternoon. The winds will 
become light and variable at 5 miles per hour or less Saturday night. The 
winds will be north or northwest around 10 miles per hour on Sunday. 


&& 


Hydrology... 
no problems expected over the next 5 days with a cold front today 
producing scattered rainfall amounts less than a quarter of an inch. 


&& 


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


&& 


$$ 
Synopsis...wasula 
near term...wasula 
short term...wasula 
long term...iaa 
aviation...iaa 
fire weather...wasula 
hydrology...15