Scientific Forecaster Discussion
fxus61 kaly 240836
Area forecast discussion
National Weather Service Albany New York
436 am EDT Sat Jun 24 2017
a cold front will move off to our east this morning bringing an
end to the showers and ushering in a drier, more comfortable
airmass. Isolated to scattered showers and perhaps a few
thunderstorms are expected Sunday afternoon as another cold
front approaches. A cooler airmass will be ushered in with the
passage this front with below normal temperatures for the start
of the new work week.
Near term /until 6 PM this evening/...
a warm and humid/muggy airmass is still in place across the
forecast area. This airmass will be replace today with the
passage of a cold front. The boundary is working its way across
the local area. It will move off to our east this morning bringing
an end to the shower activity. A drier and more comfortable
airmass will be ushered in on breezy and gusty westerly winds.
Dew points currently in the mid 60s to lower 70s will drop into
the 50s this afternoon. Will be warm again today up the Hudson
Valley into portions of the Berkshire and across northwestern
Connecticut with highs in the lower to mid 80s. Otherwise
temperatures expected to top out in the mid to upper 70s with
some cooler reading across the highest terrain.
Short term /6 PM this evening through Monday night/...
short waves will rotate about a large upper level low over the
hudson's Bay region deepening the trough over the Great Lakes
region and shifting it eastward.
The region will be between short waves tonight. Expecting fair
weather and seasonable temperatures with diminishing winds this
A short wave and its associated a cold front will be in the
approach Sunday. Scattered showers are expected as instability
develops with the heating of the day along with the threat for a
few thunderstorms. Threat will wane in the evening with the
loss of heating. Temperatures are expected to seasonable Sunday
and Sunday night with partly to mostly cloudy skies.
The next short wave will begin to sharpen the trough Monday into
Monday night. Again scattered convection is expected to develop
with help of instability from diurnal heating. However greater
coverage is expected as heights will begin to fall and this
will help to maintain threat for showers Monday night. The
chances for thunderstorms should be be tied to daytime heating.
With more cloud cover expected Monday temperatures will be
cooler with highs in the mid 60s to upper 70s.
Long term /Tuesday through Friday/...
on Tuesday, models are in generally good agreement that the
sharpening longwave trough axis will swing across the forecast area.
This will be an anomalously deep trough with h500 heights around -2
South Dakota per the gefs. The thermal profiles are also anomalously cool,
with h500/h850 temps around -22c/+7c per the European model (ecmwf). With the dynamic
forcing from the upper trough, as well as the midlevel cold pocket,
expect diurnally enhanced scattered convection to occur. The best
coverage would appear to be across the north. High temperatures
appear to come up well short of seasonal normals.
Northwesterly upper flow quickly builds in on the back side of the
trough, leading to subsidence and tranquil weather Tuesday night
into Wednesday. Temperatures still somewhat on the cooler side.
Thursday and Friday, quasi-zonal, fast midlevel flow sets up. At
lower levels, return southwesterly flow around the high will result
in a warm and moist advection pattern. A stalled low-level frontal
boundary may provide the focus for rounds of showers and
thunderstorms toward the end of the week within this warm and humid
environment, with lift possibly augmented by shortwave troughs
embedded within the midlevel flow. Low confidence with respect to
the timing and location of the lifting mechanisms, so a broad-brush
approach with chance pops was used until things become clearer.
Aviation /08z Saturday through Wednesday/...
showers have remained scattered within a very moist, weakly
forced environment. Coverage of showers should increase somewhat
through 10-11z as a cold front slowly approaches. Coverage
should be greatest over kpou/kpsf as the northern extent of a
broad precip shield associated with the remnants of tc Cindy
brushes those terminals. Confidence not high in IFR conditions,
but also not high enough to remove them from the going forecast.
Have targeted the 08-12z timeframe for the most likely period of
IFR with both vsby and cigs. Activity should remain more
scattered at kgfl/kalb, where VFR should prevail outside of
showers. Included a tempo through 10z for MVFR conditions in
showers, though cannot rule out brief period of IFR vsby as
showers could contain heavy downpours. Will amend if necessary.
Weak instability persists, but given dearth of lightning
upstream, have removed ts from the tafs. Cannot rule out a rogue
lightning strike, though.
Drier air filters in rather quickly after 12z with conditions
becoming VFR by mid to late morning at the latest. Few-scattered VFR
cu and perhaps some cirrus is all that's expected in the skies
for much of the daylight hours.
Winds will shift from south-southwest to westerly by 12-15z.
Speeds will be mainly around 5-10 kt through mid-morning before
becoming more gusty during the late morning into the afternoon.
Wind gusts of 20-25 kt are possible during the afternoon hours.
Sunday night: low operational impact. Slight chance of rain showers.
Monday: moderate operational impact. Chance of rain showers...tsra.
Monday night: moderate operational impact. Chance of rain showers.
Tuesday: moderate operational impact. Chance of rain showers...tsra.
Tuesday night: no operational impact. No sig weather.
Wednesday: no operational impact. No sig weather.
wind gusts of 25 to 30 mph expected this afternoon...
A cold front will move off to our east this morning bringing an
end to the showers and ushering in a drier, more comfortable
airmass. Westerly winds will increase to 10 to 15 mph today
with gusts of 25 to 30 mph. Relative humidity values are
expected to drop to minimums of 35 to 45 percent this afternoon.
Winds will diminish this evening. Winds will be westerly again
Sunday but not as strong at around 10 mph with gusts into the
teens. Isolated to scattered showers and perhaps a few thunderstorms
are expected Sunday afternoon as another cold front approaches.
Minimum relative humidity values of 45 to 55 percent are expected
hydrological problems are not anticipated through over the next
several days. A cold front will move off to our east this
morning bringing an end to the showers and ushering in a drier,
more comfortable airmass. Isolated to scattered showers and
perhaps a few thunderstorms are expected Sunday afternoon as
another cold front approaches. The weather will remain unsettled
early next week as another low pressure system approaches and
moves across the region with chances for convection Monday
afternoon into Tuesday.
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
kgfl Airport observations are coming in and we will continue to
monitor this trend.