Forecast Discussions mentioning any of "ACARS" "MDCRS" "AIRCRAFT" "TAMDAR" "AMDAR" "WVSS" received at GSD on 11/05/23

Area Forecast Discussion

National Weather Service Louisville KY

 912 PM EDT Sat Nov 4 2023

.Forecast Update...
Issued at 905 PM EDT Sat Nov 4 2023

The current forecast from the afternoon package remains in great
shape, and no significant changes are planned at this time. Upper
shortwave has brought an increase in mid and high level clouds as
expected, and a few radar echoes over the Wabash Valley. SDF ACARS
soundings reveal a deep dry layer extending from the sfc to around
600mb, so it`ll be fairly difficult for any precip to actually make
it to the ground as those echoes move across southern IN. Mid and
high level clouds linger through the overnight, but will clear from
west to east tomorrow morning. Given that the cloud coverage will be
diminishing by the coolest part of the morning, the main challenge
remains the low temperatures for overnight. These clouds may be high
enough (or clear out just in time) to allow for ridge/valley
temperature splits tonight, which we already see on the KY Mesonet
in the Cumberland County area. Because of this, will maintain cooler
temps in the valleys in the forecast update.

Otherwise, the associated sfc front will be passing through the
region tonight, but the lack of available moisture keeps the dry
forecast going.

&&

.Short Term...(This evening through Sunday)
Issued at 221 PM EDT Sat Nov 4 2023

An upper wave over the Midwest this evening will slide into the Ohio
Valley overnight. This feature will primarily be responsible for
bringing widespread mid-level clouds into the region, though a stray
sprinkle or two can`t be completely ruled out a few hours either
side of midnight along and north of Interstate 64. Temperatures will
be a little tricky tonight with clouds for much of the overnight
hours but then clearing at the climatologically coldest part of the
day. Will go with lows ranging from the upper 30s in southern
Indiana to the middle 40s in southern Kentucky, and cooler in
sheltered valleys given the nearly calm winds and just-in-time
clearing.

The clouds will continue to push off to the east Sunday, with mostly
sunny skies and light winds expected for the bulk of the day as a
surface ridge crosses the area. Afternoon temperatures will peak in
the 60s.

.Long Term...(Sunday night through Saturday)
Issued at 310 PM EDT Sat Nov 4 2023

Key Messages:

- Mostly dry conditions continue through early next week.

- Warmer temperatures with stronger winds by midweek with higher
chances of rain Thursday and Friday.

Synopsis...Progressive, quasi-zonal flow aloft will be present over
the Ohio Valley during most of the period as the broader mid-level
pattern exhibits split jet streams with some degree of amplification
towards the end of the forecast. Initially, a flattened mid-level
ridge building over the Ohio Valley area will dampen the influence
of a low-amplitude, northern-stream shortwave trough moving through
the Great Lakes on Monday. As a result, attendant cold front will
lose momentum and stall in the vicinity of southern Indiana/northern
Kentucky. By midweek, a larger trough will move inland from the
Pacific while the upper ridge briefly builds over the East CONUS,
helping lift the stalled boundary north. As the trough tracks east
across the Plains, it will deamplify while lifting and merging with
a stronger Canadian system. The additional injection of energy will
result in a surface cyclone quickly ejecting through the area on
Thursday with a cold frontal passage, and higher rain chances, by
the end of next week. Conditions will most likely turn dry and
cooler for next weekend but there is increasing model uncertainty
during this timeframe.

Model Evaluation/Confidence...Overall, there is decent model
consensus regarding the synoptic evolution through the middle of
next week and minor adjustments will be needed to capture the low
probability of light rain or any sprinkles that could happen Tuesday
and Wednesday as the front remains stalled north of the forecast
area. Model differences regarding timing of heavier precipitation
start to appear Thursday-Friday as the cold front sweeps the area.
In this case, GFS seems to be a slower solution (Friday) compared to
the deterministic ECMWF (Thursday) while the CMC could be seen as a
compromise of both solutions. Last but not least, model variability
continues to grow for next weekend as GFS has been showing
(inconsistently) some kind of detached trough/closed low pulling
enough moisture to host showers Sunday night into Monday. However,
run-to-run variability and lack of support from other models favors
dry and stable conditions.

Sun Night - Monday...Stable and increasingly warmer weather is still
expected for Monday as dry air remains anchored in the low- to mid-
levels. Approaching northern-stream shortwave and attendant cold
front will allow breezy conditions (gusts around 25 mph) to begin
Monday afternoon with some cloud cover over southern Indiana and
northern Kentucky as relatively modest LLJ pushes ahead of the
front.

Mon Night - Friday...Low probability of light rain showers and some
sprinkles will be in place for Tuesday and Wednesday as the stalled
front wobbles north of the area and finally starts to lift as a warm
front on Wednesday. Most importantly, the east-to-west oriented LLJ
will feature breezy conditions on Tuesday, especially for areas that
receive plenty of solar heating. As a result, higher wind gusts
could be experienced in southern KY compared to the northern half
where deeper cloud cover is expected. Even higher gusts (around 30
mph or more) are possible on Wednesday due to the combination of the
strengthening LLJ ahead of the ejecting surface cyclone and clearing
of the warm sector. Thursday and Friday will be influenced by the
cold front passage with higher rain chances, but no mention of
thunder at the moment given the lack of instability. Timing of
heaviest precipitation depends on model selection but should focus
between Thursday afternoon and Friday morning.

Next Weekend...Cooler and dry weather returns to the region as
surface high pressure brings a continental airmass to the region. A
light northerly breeze will develop in the afternoon while mostly
clear skies will predominate.

&&

.Aviation...(00Z TAF Issuance)
Issued at 700 PM EDT Sat Nov 4 2023

Mid and high level clouds will blanket the region overnight, though
VFR conditions will continue for the entire period. Winds will be
light and variable at all terminals overnight. For tomorrow, should
see the high level clouds clear out to SKC, and winds will remain
light and from the north.


&&

.LMK WATCHES/WARNINGS/ADVISORIES...
IN...None.
KY...None.
&&

$$

Update...CJP
Short Term...13
Long Term...ALL
Aviation...CJP



Area Forecast Discussion

National Weather Service Mount Holly NJ

 950 PM EDT Sat Nov 4 2023

.SYNOPSIS...
High pressure will be in control through tonight. A dry cold front
passes on Sunday, with high pressure moving in for Sunday night/Monday.
A warm front lifts through on Monday Night, with a cold front passing
on Tuesday. A brief period of high pressure moves in for Tuesday
night/early Wednesday with a few waves of low pressure moving through
towards the middle and end of next week.

&&

.NEAR TERM /THROUGH SUNDAY/...
Only notable change for the late evening update was to nudge
hourly temps up just a touch for the next few hours as the cloud
coverage has lead to a slower drop off after sunset. Recent PHL
ACARS soundings show the pronounced low level dry layer in
place as the broad shortwave evident on water vapor imagery
traverses the lower Great Lakes. The mid/upper cloud deck is
starting to break up some, but expect that scattered cloud
coverage will remain around through the overnight hours.

The low anchored along the cold front will lift northeast, away
from the region overnight. While the cold front approaches our
region on Sunday, frontolysis will be in effect, so expect to
see little in the way of cold air advection, and only a minor
shift to northwesterly flow. Very dry air will remain in place
between 900 and 500 mb, so don`t expect any precipitation
associated with the front.

The only potential complication is the possibility (40-50%
chance) for some very shallow ground fog to develop primarily
over the coastal plains late tonight. Some developed Saturday
morning, and with little difference expected by Sunday morning,
it appears that at least patchy fog will once again be possible.
Lows will be near normal in the upper 30s/low 40s areawide.

The SW flow should help keep overnight temperatures a bit higher
than what we have seen the last few days, with most areas
expected to stay above freezing. What little cold air advection
there may be behind the front, it isn`t likely to develop early
enough tomorrow to have any impact on high temperatures, to
highs tomorrow will be near if not a few degrees higher than
Saturday high temperatures.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH MONDAY/...
Dry during the short term despite a rather deep low passing by
to the north Mon/Mon night. We`ll have some extra cloudiness in
the grids for the northern CWA for those periods. Most of the
latest guidance is keeping the steadier rains across NY and NE
areas. We`ll follow along and only mention a chance pop for the
highest areas of the southern Poconos and north NJ for Monday
night. A dry cold front passes later Tue, so the mild temps Tue
will only be a one-day experience.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
Rather brisk flow aloft will keep frequent changes during the long
term period. We`ll start off with some pleasant weather Tue night
and Wed as high pressure moves across the region. Temperatures will
be near normal with highs Wed in the low/mid 50s for the NW areas
and upper 50s/low 60s for Delmarva and adjacent regions.

The weather will become a bit more active Wed night/Thu as low
pressure develops/moves up the Ohio Valley and towards the Great
Lakes. Milder and more humid air arrives ahead of the low providing
above normal temps for Thu when readings will climb into the upper
60s/low 70s for the southern half of the CWA. Even some mid 70s are
possible too. Up north, highs will mostly be in the upper 50s/low
60s. Pops will be, by-in-large, in the chance range from Wed night
thru Thu. Higher pop numbers across the north, closer to the storm
track. A cold front will follow for Fri, so readings will be back on
the downswing for the end of the week and into next weekend.

&&

.AVIATION /02Z SUNDAY THROUGH THURSDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY and surrounding areas...

Tonight...Mostly VFR conditions expected. There is a chance
(40-50%) that shallow ground fog will develop over the coastal
plains late tonight after 09z. Have included a tempo group at
KMIV to account for this with most hi res guidance reducing
visibility, otherwise do not expect any impacts to the other TAF
sites. Winds will remain light (5 kt or less) through the
period. Direction should favor SW, but could be variable at
times, especially after 22Z. High confidence on most aspects of
the forecast, but moderate confidence on the potential for
visibility restrictions at KMIV.

Sunday...VFR conditions expected. Winds starting light and
variable, but should settle out of the NW at 5 to 10 kt. High
confidence.

Outlook...

Sunday Night...VFR. Northerly winds around 5 kt. High confidence.

Monday...VFR. Variable winds becoming South around 5-10 kt. High
confidence.

Monday Night...Primarily VFR. South/Southwest winds increasing to
around 10-15 kt. Medium confidence.

Tuesday...VFR. Westerly winds around 10-15 kt and gusts 20-25 kt.
Moderate confidence.

Tuesday Night...VFR. Northwest winds around 10 kt. Moderate confidence.

Wednesday...Primarily VFR, though restrictions possible with showers
and cloud bases lowering for the NW areas. North/northeast winds
around 10 kt. Low confidence.

Thursday...Restrictions possible with chance for showers.

&&

.MARINE...
Winds and seas should stay below Small Craft Advisory criteria through
Sunday. There is a small chance (30%) for shallow fog to develop near
the shoreline of the Delaware Bay. Otherwise, no marine hazards are
anticipated.

Outlook...

Sun night/Mon... sub-SCA. Fair weather.

Mon night/Tue... SCA possible. Fair weather.

Tue night thru Wed... sub-SCA. Fair weather.

Wed night/Thu... SCA possibly developing Thu. Chance of showers.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...None.
NJ...None.
DE...None.
MD...None.
MARINE...None.

&&

$$

SYNOPSIS...Hoeflich
NEAR TERM...Brudy/Johnson
SHORT TERM...Hoeflich
LONG TERM...Hoeflich
AVIATION...Brudy/Hoeflich/Johnson
MARINE...Hoeflich/Johnson