Area Forecast Discussion Issued by NWS Albany, NY
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000
FXUS61 KALY 231048
AFDALY
AREA FORECAST DISCUSSION
National Weather Service Albany NY
648 AM EDT Mon May 23 2022
.SYNOPSIS...
Fair weather is expected today into Wednesday with high
pressure in control.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
High pressure gradually building into our region from the west
and the tight thermal gradient on the leading edge of deeper
cold advection will track through our region this morning. The
low level forcing and lingering boundary layer moisture will
support intervals of clouds and sun with increasing sunshine
through the afternoon.
Lots of high clouds well in advance of the system in the SE U.S.
also streaming into our region and will continue through
tonight. So, north to northwest winds, cooling at the boundary
layer and a mix of clouds and sun will limit heating somewhat
today. Highs in the upper 60s to lower 70s with around 60 to mid
60s higher terrain.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
Low level ridging continues to build into our region tonight and
Tuesday and low level winds will trend to light to calm.
considerable high clouds are expected tonight but there will be
periods of thinning high clouds, especially along and north of
I-90. By Tuesday morning, much of the high cloudiness should be
confined to the mid Hudson Valley and NW CT, if even that far
north. So, some intervals of thin high clouds over most of the
region should allow for more sun than clouds. Temperatures
should reach the upper 60s to lower 70s with mid 60s higher
terrain.
There are hints in sources of guidance/ensembles for a weak wind
shift boundary to drift north through our region later tonight
through Tuesday as high pressure shifts east of our region and
weak boundary layer warm advection begins. The northward
drifting weak wind shift boundary is expected to shift low level
winds to light southeast to south. Low level dew points will
begin to slowly rise as well.
So, there are uncertainties on whether low clouds will develop
in response to the weak boundary and increasing low level
moisture tonight through Tuesday. Indicating intervals of
clouds Tuesday and Wednesday with highs both days in the upper
60s to lower 70s. It could be a degree or two warmer, especially
Wednesday, if there is more sun and less clouds. Lows Wednesday
night with increasing clouds well ahead of the next upper
energy and associated cold front, in the upper 40s to lower 50s.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
Main forecast challenges for the long term are focused on the
Thursday night to Saturday period as an upper level trough from the
Midwest and associated surface cold front track eastward resulting
in a chances for showers and possible thunderstorms. Depending on if
the parent trough cuts off, unsettled conditions may linger into
Sunday but trends point to improving conditions. Otherwise,
temperatures remain seasonable or slightly above normal through the
majority of the period. Read on for details.
We start off the long term on Thursday with surface high pressure
sliding off the East Coast with southwest flow in place aloft over
the Northeast as a surface warm front attempts to push northward
through the region. In response to surface winds out of the
southeast ahead of the incoming front, temperatures Thursday look to
be seasonable or slightly cooler than normal due onshore flow. In
addition, guidance hints that a weakening disturbance from the Gulf
Coast States could get caught within the southwest flow and push
northward into the Northeast. Since guidance shows potential for
this system to result in some weakened showers for areas south of I-
90, we continue to show slight chance and chance POPs.
By Thursday night, the warm front should be north of our area with
the associated warm sector spreading into eastern NY and western New
England. Temperatures Thursday night should be rather warm as a
result with the humidity also rising. We will remain in the warm
sector on Friday as the surface cold front tracking eastward. At
this point, important discrepancies in the 500hPa pattern result in
different solutions for the rest of the Memorial Day Holiday.
The 00 UTC ECMWF suggests a northern stream shortwave tracking
through the Canada Prairie Provinces phases with a neutrally tilted
southern stream shortwave trough over the Upper Midwest Thursday
night. As a result, the phased shortwave rides up and over the
downstream ridge with the sfc cold front and trough both tracking
through the Northeast during the day Friday. With a rather clean
exit Fri night, high pressure builds back into the region for
Saturday suggesting a dry and warm start to the holiday weekend. On
the other hand, the CMC and GFS paint a more pessimistic picture,
suggesting the northern stream trough in south central Canada
outruns the southern stream trough and, as a result, the two
fail to phase. With strong downstream ridging still in place
over the western Atlantic, the southern stream wave slows down
and matures into a closed low before arriving in the Northeast
Friday night or Saturday. Not only does this enhance
precipitation along the incoming surface cold front but both the
GFS and CMC suggest the front could linger into Saturday. This
would keep chances for rain and possible thunderstorm in the
forecast. The GFS ensembles indicate a wide variety of
solutions, both wet and dry, but the GEFS show negative height
anomalies lingering into Saturday. While this is still a low
confidence forecast, we collaborated with neighboring offices
and decided to linger chance POPs in Saturday before showing
improving conditions by Sunday and especially Monday.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
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VFR conditions at all TAF sites will remain in place through the
end of the TAF period. Southwest flow aloft will allow high
clouds to continue spreading northeastward from the mid-
Atlantic over the TAF sites through the day resulting in SCT-BKN
clouds at or over 20kft.
North-northwest winds today will shift to the north-northeast
by 15 - 18 UTC and will remain a bit breezy sustained near 5
- 12kts through sunset.
Outlook...
Tuesday Night: No Operational Impact. NO SIG WX.
Wednesday: Low Operational Impact. NO SIG WX.
Wednesday Night: Low Operational Impact. Isolated SHRA.
Thursday: Moderate Operational Impact. Breezy. Chance of SHRA.
Thursday Night: High Operational Impact. Likely SHRA.
Friday: High Operational Impact. Breezy. Likely SHRA...TSRA.
Friday Night: Moderate Operational Impact. Chance of SHRA.
Saturday: Low Operational Impact. Slight Chance of SHRA.-- End Changed Discussion --
&&
.FIRE WEATHER...
Fair weather is expected today into Wednesday with high
pressure in control.
RH values will drop to the 35 percent to 45 percent range this
afternoon, then increase to above 65 percent tonight. RH values
drop again to the 35 percent to 45 percent range Tuesday
afternoon.
North to northwest winds to day increasing to around 15 mph,
then become light tonight. WInds Tuesday become southeast to
south at less than 15 mph.
The fair weather will continue into mid-week with unsettled
weather for the latter part of the week.
&&
.HYDROLOGY...
No hydrologic concerns are expected through at least the first
half of this week with fair weather expected. Unsettled weather
returns for the latter part of the week.
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...
CT...None.
NY...None.
MA...None.
VT...None.
&&
$$
SYNOPSIS...NAS
NEAR TERM...NAS
SHORT TERM...NAS
LONG TERM...Speciale
AVIATION...Speciale
FIRE WEATHER...NAS
HYDROLOGY...NAS