Weather

848 
fxus61 kbgm 071748 
afdbgm 


Area forecast discussion 
National Weather Service Binghamton New York 
148 PM EDT sun Sep 7 2008 


Synopsis... 
weak high pressure will bring drier conditions to upstate New 
York and northeast Pennsylvania through Monday. A few light 
showers may affect The Finger lakes this afternoon...with clearing 
skies later on. The next best chance for rain will be Tuesday, as 
a strong cold front crosses the area. High pressure will return 
for Wednesday and Thursday. 


&& 


Near term /through tonight/... 
as of 1150 am EDT... 
not many changes to ongoing forecast. Have tweaked placement of clrng skies 
a tad...with mosunny conds across west and southwestern zones and still 
mostly cloudy elsewhere. Expect conds to imprv around 18z...but only for a 
brief time before more expansive middle-deck mvs in ahead of shortwave. 


Given extent of rain mvng into central New York...have boosted probability of precipitation to 30 
across The Finger lakes. Models indicate this area will weaken as it 
heads east...but still expect to see showers slip into the western 
zones aftr 18z for a time today. Only expecting isolated covering along 
I-81 corridor. 


Some minor tweaks made to hrly temperatures. Temperatures are struggling to 
reach into the u60s where cool northwest flow and clouds are impacting the 
region. Not looking at much more of a temperature rise today...except 
maybe for an hour or two after clouds break. Thus...have modified hrly 
temperature rise from about 18z-20z with most locations struggling to 
reach 70 for afternoon maximum. No other changes needed at this time. 


Previous discussion... 
high pressure is building in as Hanna speeds NE from Cape Cod to 
southeast Canada. Clearing trying to work into County Warning Area but having trouble 
with north flow and added moisture off Lake Ontario. Much low 
clouds so higher elevations have some patchy fog now. In addition 
if clearing gets here the moist ground will create radiation fog. 
For these reasons have left patchy early morning fog in the 
forecast. 


&& 


Short term /Monday through Tuesday night/... 
a quick moving short wave and ul trough is moving NE from the Midwest 
into Ontario/Quebec. This will brush the northwest County Warning Area with clouds and 
some showers. Current radar has an area of showers from SW mich 
to central Illinois. Adding to the moisture will be a favorably aligned west-northwest 
low level flow off Lake Erie. 


Tonight with 850 temperatures dropping to +8c and Lake Ontario surface temperatures 
at 70 low level instability is conditional. Ll flow shifts 
slightly closer to west. Some forcing early as the short wave passes 
through in the evening. Have put a 20 to 30 pop for the extreme 
north. 


Surface high pressure is stronger over the County Warning Area on Monday as the next 
ul trough gets into the western Great Lakes. Ul heights rise and a SW 
flow increases. Maximum temperatures will be warmer. For the Monday PM the 
best warm air advection will be to the northwest so have kept it dry. 


On Tuesday...surface low and best forcing will be lifting NE into 
Ontario. Still a strong surface cold front with ul height falls and in 
rr quadrant of ul jet. Timing has slowed some over the last few days 
so the frontal passage will be in the afternoon. With the strength of the front 
and some surface heating into midday have kept the chance of ts. 


Tuesday night partial clearing with strong winds and cold air advection. Strong 
high builds in behind the front. Not confident on total clearing 
with northwest flow and conditional lake effect instability again. 850 
temperatures to fall to near 0c. 


&& 


Long term /Wednesday through Saturday/... 
current extended in good shape after looking at latest GFS/ECMWF. 
Once again only minor tweaks made and included chance probability of precipitation for 
Saturday as both GFS/European model (ecmwf) and HPC indicate frontal boundary in 
vicinity with surface wave in Great Lakes region. 


Previous disc... 
Wednesday and Thursday look like a nice couple of days as surface 
high moves across and east of the region. Moisture then increases 
Thursday night into Friday as another front pushes east. Looks 
like we then dry out again at the end of the period with weak high 
pressure in place. 


Temperatures may be a bit below seasonal averages behind the front 
Wednesday, but otherwise look to be not too far from normal for 
much of the period. 


&& 


Aviation /18z Sunday through Friday/... 
upper level trough of low pressure will swing north of the region this 
afternoon. VFR middle level broken-overcast ceilings will cross the flight area 
this afternoon and early evening with occasional light rain showers...esply kith- 
ksyr-krme. Clouds becmg sky clear-scattered tonight. Cooling near the river 
around kelm may allow LIFR fog/ceilings to develop shortly before 
sunrise. 


Outlook... 
Monday...VFR. Some early morning restrictions in fog most likely 
at Elm. 


Monday night to Tuesday...next front approaches late Monday 
night with MVFR restrictions in showers and possibly thunder along 
boundary Tuesday. 


Wednesday to Thursday...VFR. Restrictions possible in morning fog 
especially at Elmira. 


&& 


Bgm watches/warnings/advisories... 
PA...none. 
New York...none. 


&& 


$$ 
Synopsis...pvb 
near term...pvb 
short term...tac 
long term...jml/rrm 
aviation...jab/jml