Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

Area forecast discussion 
National Weather Service Albany New York
746 am EDT Sat Oct 25 2014

high pressure will briefly build in from the south this
morning. A cold front and an upper level disturbance will approach
from the Saint Lawrence River valley this afternoon with some
scattered showers. The scattered showers will persist Saturday
night into Sunday with brisk and cool conditions for eastern New
York and western New England.


Near term /until 6 PM this evening/...
as of 657 am EDT...surface anticyclone near the Ohio Valley and the
middle Atlantic region will remain south of the forecast area today.
A weak surface warm front/pre frontal surface trough will move across
upstate New York and western New England in the late morning through the a cold front approaches for the late afternoon and
evening. The cold front is on the leading edge of a strong upper
level trough. A strong h250 jet streak of 125-150 kts will
approach western New York by the early evening. The forecast area will be near
the left front quadrant or cyclonic exit region of the upper jet
streak. The best qg lift for showers in the late afternoon/early
evening will be north and west of the capital region for scattered-
numerous showers. The latest hires WRF brings the showers into
locations north and west of the Tri Cities between 19z-22z today. The
cold front looks to cross most of the region between 00z-06z.

Temperatures will rebound closer to seasonable levels ahead of the cold
front...with some sunshine after the patchy valley fog Burns off.
H850 temperatures of +4c to +7c with decent mixing and some sunshine
should allow maximum temperatures to reach u50s to m60s in the valleys. The
m60s will be mainly in the middle Hudson Valley...and u40s to m50s
over the mountains the winds will increase from the southwest to west
at 10 to 15 miles per hour.


Short term /6 PM this evening through Monday night/...
tonight...the best cyclonic vorticity advection with the upper
level trough impacts the forecast area with enough qg lift generated
for isolated to scattered showers over most of the region...and numerous
showers over the western dacks/western Mohawk Valley as some lake moisture
is utilized. As the previous discussion mentioned...the low and
middle level lapse rates steepen across the region with small amounts
of instability /100-300 j/kg/. The middle level lapse rates are
generally in the 6.5-7.5c/km range on the NAM/GFS. A rumble of
thunder may be possible from the capital region north and west
which is close to the general thunder forecast by Storm Prediction Center in the new day
1. The best jet dynamics sweep across the area overnight. Lows
will be in the 40s with some u30s over the southern dacks...southern greens
and eastern Catskills.

Sunday-Sunday night...the potent upper level low will drift across
the region. By 18z sun...the closed h500 circulation will be near
northern ME and New Brunswick. Instability showers will
occur...especially over the higher terrain...and downwind of Lake
Ontario. A strong cold advection regime will impact eastern New York and
western New England with the strong cyclonic flow aloft. H850 winds
increase to 35-45 kts. Decent momentum Transfer will favor brisk
conditions with west to northwest winds of 10 to 20 miles per hour with some gusts in
the 30 to 35 miles per hour range. Maximum temperatures will run a little below normal
with highs mainly in the lower to m50s in the valleys...and m40s
to near 50f over the hills and mountains the winds will only slightly
decrease overnight...since a noticeable surface pressure gradient will
set up over the area with high pressure near the middle Atlantic
region...and low pressure moving east of New Brunswick towards
Labrador. Isolated-scattered showers will linger overnight west of the
Hudson River valley. Lows will be chilly in the 30s in most
locations with some u30s to l40s in the capital district...middle
Hudson Valley and CT River Valley.

Monday-Monday night...moderating trend for temperatures as surface high ridges in
from the middle Atlantic region...and h500 anticyclone builds in from
Ontario and the Great Lakes region. Partly to mostly sunny
conditions expected to open the week in the warm advection regime.
H850 temperatures surge back to +6c to +11c by 00z/Tuesday according to the
GFS with temperatures trending above normal by Tuesday. Middle and high clouds
increase Monday night with a slight chance of showers over the western dacks
late. Lows will be milder in the lower to middle 40s in most
locations...except some middle and u30s over southern Vermont...the
Berkshires...southern dacks and parts of the eastern Catskills.


Long term /Tuesday through Friday/...
model guidance is in fairly good general agreement amplifying the
longwave pattern as we head through next week. Ridging over the
region shifts off to the east Tuesday with a trough returning. This
trough is expected to get reinforced late in the week. Differences
in the guidance grow as they deal with short wave energy diving
southeastward out of central Canada and its impacts on the longwave
pattern and the associated surface low/system.

Mild day expected for Tuesday with broad/deep southwest flow across
region as ridging shifts offshore and trough/low pressure system
approach. Highs are anticipated to be 10 to 15 degrees above normal.

The low passes well to our north and west with its trailing cold
front moving across the area Tuesday night into Wednesday
accompanied by some showers. Wednesday should be bit cooler
however temperatures are still expected to be above normal by 5 to
10 degrees. The cold front moves gradually off to our east...however
the upper trough will still need to swing through.

A return to seasonable temperatures expected as we head into
latter part of the week. Higher pressure is expected to build in
on Thursday with the flow aloft flat as the region will be between
short waves. Heights expected to begin falling Thursday night with
chances for showers returning on Friday.


Aviation /12z Saturday through Wednesday/...
the 11-3.9 microns satellite and observations indicate stratus
across portions of the western Adirondacks...Mohawk
Valley...southern Green Mountains and Berkshires. Kgfl has LIFR
conditions due to fog with kpsf IFR due to stratus. After sunrise
fog and stratus will burn off and lift.

Clouds will be in the increase this afternoon as a low pressure
system approaches from the west. The area is expected to be in the
system warm sector by this evening with chances for showers as the
cold front approaches. With isolated to scattered coverage expected
have addressed threat of showers with vcsh.

Winds are calm to light with direction driven by local effects.
Southwest-west winds will develop with a shift more to the south
in the warm sector. The winds will then shift back to the west
and northwest with passage of the cold front and increase in speed
with gusts to 20 kts on Sunday expected at kalb and kpsf.

Sun night-Tue: no operational impact. No sig weather.
Tuesday night-Wed: moderate operational impact. Chance of rain showers.


Fire weather...
no significant fire weather issues are anticipated over the next
several days due to the wet weather over the past 3 to 4 days.

High pressure will briefly build in from the south this
morning. A cold front and an upper level disturbance will approach
from the Saint Lawrence River valley this afternoon with some
scattered showers. The scattered showers will persist Saturday
night into Sunday with brisk and cool conditions for eastern New
York and western New England. West to northwest of 10 to 20 miles per hour
with some gusts in the 30 to 35 miles per hour range will be possible Sunday

The relative humidity values will lower to 45 to 70 percent this afternoon...then
increase to 80 to 100 percent tonight...before falling to 50 to 70
percent on Sunday afternoon.


no Hydro problems are expected the next 5 days.

Rivers flows will continue to decrease the next few days. Mainly
scattered showers are expected this afternoon into Sunday with
total rainfall amounts of a few hundredths to a few tenths of an
inch. Some controlled dam releases will have minimal impacts
immediately downstream on river points.

Dry weather with warming temperatures are expected Monday into the middle
of next week...which will allow levels to recede further.

For details on specific area rivers and lakes...including observed
and forecast river stages and lake elevations...please visit the
advanced hydrologic prediction service /ahps/ graphs on our website.


Aly watches/warnings/advisories...
New York...none.


near term...wasula
short term...wasula
long term...iaa
fire weather...wasula

National Weather Service Glossary of Abbreviations