Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 04/12/24
Area Forecast Discussion
National Weather Service Binghamton NY
952 PM EDT Thu Apr 11 2024
.SYNOPSIS...
Rain showers, along with a few isolated thunderstorms return to
the area tonight and will persist through at least Friday
morning. Winds will become increasingly gusty tonight. Another
round of rain showers, mixing with snow showers will move in
Friday night along with gusty winds. Cooler air returns briefly
for the weekend, with a warming trend expected again early next
week.
&&
.NEAR TERM /THROUGH FRIDAY NIGHT/...
950 PM Update:
Minor tweaks to PoPs and QPF overnight into Friday based on
latest radar trends and the 00z HRRR guidance. Winds have been
gusting up to 40mph across the hilltops this evening, and are
expected to peak during the predawn hours....a few locations may
see gusts around 45mph, but this time there was not enough
confidence or coverage of these winds speeds to issue any
advisories. Thus far the heaviest rain showers and convective
activity has remained well off to our west, over western PA.
Latest CAMs show a period of moderate rain showers rolling
through now until around 3 AM, then perhaps another brief lull
before the leftover thunderstorms/convection push across our
area toward daybreak and into the day on Friday. Not seeing
anything overly concerning as far as a flood or severe weather
threat in the latest guidance for our CWA...but of course we
will continue to monitor trends and radar closely overnight.
720 PM Update:
Overall, no significant changes were made to the near term
forecast with this update. A period of light to moderate rain
will move through the region over the next couple of hours. By
late evening and overnight several additional periods of rain,
with embedded thunderstorms will move through; these could
produce locally heavy rainfall and/or isolated damaging winds.
Synoptic, large scale winds will also continue increasing out of
the southeast overnight, and look to get close to wind advisory
criteria across some of the hilltops/exposed locations. Overall,
expect winds of 15-25 mph with gusts 30-45 mph overnight.
Rainfall totals have not changed with this update and are still
on track. Instability remains low over our CWA for most of the
overnight...however toward daybreak a north-south corridor of
MLCAPE around 200 J/kg and modestly negative LIs moves into the
NE PA and the S. Tier...this is when a few of the storms could
become stronger, with gusty winds being transported to the
surface more efficiently.
A few things to keep an eye on further out in time are: strong
wrap around moisture, with rain changing to wet snow over the
higher elevations Friday night. As temperatures aloft cool to -5C
at 850 mb and surface temps fall into the low to mid-30s will
there be some minor snow accumulations? Best chance to see any
minor accumulations ( up to 2") will be for elevations above
1800 feet in Steuben, Yates, Cortland and Southern Cayuga
counties. Will also be watching for westerly winds to increase
and these very well may reach advisory criteria across the
Central southern tier and western Finger Lakes and Central NY
Friday night into Saturday as cold air advection strengthens
behind the 985mb low over southern Canada.
400 PM Update:
Overall, a rather active period of weather is expected in the
near term forecast period as a slow moving, deepening area of
low pressure will be moving through the Great Lakes Region
through Friday night. The initial round of rain showers from
this morning associated with a warm front has moved away from
the area, allowing for mainly dry conditions this afternoon.
While skies have been mostly cloudy, occasional breaks of sun
have occurred.
An additional round of showers and even some isolated
thunderstorms associated with this low pressure system will
move into the area this evening and persist through tonight.
With PWATs just over an inch, locally moderate to heavy rainfall
will be possible. However, the showers are expected to be rather
progressive which will limit the flooding threat. That being
said, cannot rule out some isolated instances of urban and poor
drainage flooding overnight and into Friday morning.
In addition, dynamics late tonight/early Friday morning become
marginally favorable for some gusty showers and perhaps a few
thunderstorms with the associated cold front (especially west
of I-81 and south of the Finger Lakes Region). Ample bulk shear
will be present (40-50kts), along with 0-1km SRH values of 200+
m2/s2. Some elevated instability will also be present. This
presents the potential for some isolated strong to severe
thunderstorms and even a low chance of a tornado. Potential for
all of this is on the low side (especially given the non-
favorable timing with it being the late overnight), but
definitely a non-zero chance. As such, SPC has the above
mentioned areas in a Marginal Risk for Severe Thunderstorms for
late tonight.
Also, gusty synoptic winds are expected tonight with a
tightening pressure gradient. Winds may gust up to 30-40 mph at
times, especially across the higher terrain.
Rain showers will be gradually tapering off from southwest to
northeast Friday morning as the cold front moves away from the
area. Additional scattered rain showers will be possible Friday
afternoon, but overall coverage is expected to be much less.
With cold air advection, temperatures will be slowly falling
through the day; starting in the mid 50s to near 60, but ending
up in the upper 40s to mid 50s in the afternoon.
Another round of more widespread showers is expected Friday
night as the upper low moves over the area. These showers will
start out in the form of rain, before temperatures become cold
enough at some of the higher elevations for some wet snow to
mix in. Lows are expected to be in the mid 30s to lower 40s.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
225 PM Update...
The upper level trough bringing rain to end the work week will
tilt negatively on Saturday, slowing the eastward progression of
the precipitation as the surface low lifts to the north. NW flow
will move over the region, advecting in the coldest airmass of
the week. Temperatures Saturday will only climb into the mid to
upper 40s across NY with low 50s in NEPA. NW flow off the lakes
will enhance the wrap around moisture already present in the
exiting trough, bringing rain showers across the region during
the day, slowly dissipating from SW to NE.
Rain should clear out by the early evening with clearing skies
moving in from the west as a weak ridge of high pressure builds
into the area. Temperatures will fall into the mid to upper 30s
across the region.
High pressure will not stick around long as another shortwave
digs into the region from the Great Lakes. A quick burst of WAA
should occur across the Finger Lakes and Twin Tiers during the
afternoon, bringing temperatures here to the mid 60s, while
north and east of this region seeing mid to upper 50s. This
should bring enough warmth to provide some elevated instability,
especially when the cold front pushes through the region during
the late afternoon early evening hours. Elevated thunderstorms
will be possible along the front, stretching from the Finger
Lakes into the Twin Tiers and Catskills from the afternoon into
the evening hours.
Sunday night will see temperatures in the upper 30s to mid 40s
with low level moisture trapped under a dry inversion moving
into the region from the NW. This will keep low level clouds
around overnight, helping moderate overnight temperatures.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
255 PM Update...
We finally see some relief from the rain with a ridge moving
into the region for the first half of the week. The warm air
from the ridge will battle the cooler air from the slowly
departing upper trough on Monday. Temps over the Twin Tiers and
Finger Lakes should be in the mid to upper 60s with areas north
and east in the upper 50s to low 60s. The ridge finally wins out
on Tuesday, injecting temps in the upper 60s to mid 70s on
Tuesday and Wednesday across the region. Unfortunately, this
nice weather will not stick around as another low moves into the
Great Lakes Wednesday, bringing rain showers back to the region
for the rest of the week.
&&
.AVIATION /02Z FRIDAY THROUGH TUESDAY/...
745 pm update...
VFR conditions exist now but cigs and vsbys will drop to MVFR in
rain showers tonight everywhere by 02z. IFR cigs are possible at
ELM/BGM tonight with IFR vsbys anywhere with moderate to heavy
rain. Isolated thunder will be possible as well, but confidence
continues to be too low to include in the TAFs at this time.
Rain showers start to taper off Friday morning, but ceiling
restrictions are expected to remain.
Tonight southeast winds will increase to 15 to 20 kts with
gusts as high as 30 kts. Friday winds drop to 15 with gusts to
25 kts.
Low level wind shear is likely everywhere with 2k foot winds
from 160 degrees at 45 to 50 kts sustained.
Outlook...
Friday night through Saturday...Possible restrictions from rain
and snow showers. Gusty winds continue.
Sunday...Chance for rain showers and possible restrictions.
Monday through Tuesday...Mainly VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...None.
NY...None.
&&
$$
SYNOPSIS...BJG
NEAR TERM...BJG/MJM
SHORT TERM...JTC
LONG TERM...JTC
AVIATION...TAC
Area Forecast Discussion
National Weather Service Boston/Norton MA
1014 PM EDT Thu Apr 11 2024
.SYNOPSIS...
A potent frontal system will bring a round of heavy rains,
strong winds and perhaps a few embedded thunderstorms overnight
into Friday morning. Drier and mild weather is expected by
Friday afternoon, but additional scattered showers may redevelop
generally across interior southern New England. A few showers this
weekend, but not a washout along with seasonable temperatures.
Drying out and a warming trend heading into early next week.
&&
.NEAR TERM /THROUGH FRIDAY/...
1000 PM Update:
Warm sector air mass has spread over most of SNE at this hour,
most notably across CT, RI and SE MA where dewpoints were
commonly in the 50s. However we`re still dealing with a shallow
NEly drainage flow seen in METARs across southern NH and into
northeastern/eastern MA where temps and dewpoints are in the mid
40s. Its this northeastern coner of MA where visbys in fog are
the lowest, as low as a quarter mile such as been the case in a
few obs at Boston Logan. On the fog front, expecting visbys to
improve a bit more once winds turn to more of a SEly direction,
which the HRRR and NAM-3km indicate occurs in northeastern MA
during the 03-05z timeframe. Will hold on any dense fog
advisories as instances of dense fog should be becoming
increasingly shorter-lived but visbys could still get pretty low
in Greater Boston/Metrowest/North Shore areas until midnight.
Expectations for the remainder of the night as described below
still seem on track with no appreciable change there. There are
some lighter showers taking place across interior MA and CT but
we are still a few more hours before we start seeing rain turn
steady and at times heavy. SE winds have just started to
increase a bit more too along the southeastern coast; did note
OKX`s VAD showing 925 mb winds around 50 kt, so the low level
jet is starting to increase too and expect a continued increase
in winds tonight as this jetcore moves along the southern
coastline.
Previous discussion:
* Areas of fog...locally dense this evening with scattered showers
* Heavy showers with a few embedded t-storms overnight into Fri AM
* Windy overnight - Fri AM with temps rising to near 60 by daybreak
The bulk of the earlier showers with the mid level warm front has
lifted north of the region. Otherwise...a bit of a lull in the
activity as of late this afternoon with mainly dry weather. We do
expect some more scattered showers to develop this evening in the
warm advection pattern. The other issue this evening will be areas
of fog. We will have to see if this becomes locally dense this
evening with sunset. Winds will be on the increase...but high
dewpoint air may allow dense fog to develop near the south coast.
Later shifts will have to monitor closely to see if a Dense Fog
Advisory will be needed for a time this evening.
The main concerns overnight into Friday morning will be for heavy
rain & strong wind gusts...which we will discuss more below.
1) Heavy Rain & embedded t-storm risk overnight into Fri AM...
The main show will be after midnight into Fri morning. Low pressure
across the Ohio Valley will be intensifying as it lifts northeast
tonight. This will induce a strong southerly LLJ 4-5 standard
deviations above normal. This will combined with increasing Pwats
that are on the order of 3-4 standard deviations above normal.
Putting those ingredients together...widespread showers with pockets
of heavy rainfall overspread the region after midnight and persist
into at least the first half of Friday morning. There also is some
elevated instability...with the SPC SREF and 3 KM NAM indicated a
few hundred J/KG of MUCape. Therefore...have included the risk for a
few embedded t-storms as well.
Rainfall amounts should generally be on the order of 0.75 to 1.50
inches with localized 2" amounts possible if any convection
materializes. This may result in pockets of typical minor street
flooding & make for a slower than normal commute for part of the Fri
am commute...but the rain is progressive enough to prevent the need
for widespread Flood Watches. That being said...we did continue a
River Flood Watch for the Pawtuxet River at Cranston as well as the
Wood River at Hope Valley. The heavy rain may result in minor River
Flooding developing in these locations.
2) Period of Strong Winds overnight into Fri AM...
The other concern will be for a period of strong winds overnight
into Friday morning. The southerly LLJ at 850 mb increases to
between 75 and 85 knots ahead of the shortwave. It is always tricky
to determine exactly how much wind will mix down given a modest
inversion in place. However...temps climbing to near 60 toward
daybreak will help to erode that a bit. That combined with
climatology prompted us to expand the Wind Advisory onto the I-95
corridor. A period of southerly wind gusts of 40 to 50 mph are
anticipated. Further inland...we think southerly wind gusts of 30-45
mph are expected too but kept things below thresholds for now.
&&
.SHORT TERM /FRIDAY NIGHT/...
Key Points...
* Drier Fri afternoon although some scattered showers re-develop
* Highs Fri in the 60s with breezy conditions
Details...
Friday afternoon...
The bulk of the heavy rain will have exited the region by Fri
afternoon. So drier weather expected by Fri afternoon...but vigorous
shortwave energy remains to our west. This coupled with some partial
clearing as the afternoon wears along will allow for a bit of
destabilization. The bulk of this energy will be west of our
region...but scattered showers will probably re-develop in the
afternoon. The bulk of which will be across interior MA/CT closer to
the main shortwave. Despite mid level temps dropping through the
day...a very mild start with temps near 60 at daybreak will support
a mild afternoon. Highs should top off well into the 60s in many
locations away from the south coast. It will also remain quite
breezy into Friday afternoon with southwest gusts on the order of 25
to 40 mph.
Friday night...
Vigorous shortwave energy still remains to our west. This is where
the main forcing for scattered showers will be Friday night. So much
of Friday night will be dry...but a few spot showers are still
possible mainly across interior southern New England. Overnight low
temps will be in the 40s.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
Highlights:
* A few spotty showers Saturday morning and late Sunday night,
otherwise looking more dry than wet for the weekend.
* Dry and warming up for early part of next week.
Saturday - Overall more clouds than sun with nuisance rain showers
due to a weak surface low pressure system developing off the south
coast, the good news, doesn`t seems to pack much moisture. With that
said, areas far western Massachusetts are likely to have the greater
chance of more numerous light showers. PWATs are around half an inch
and is fairly close to the climatological normal. QPF, is less than
a tenth of an inch, with a few hundredths near the coast. But there
are higher QPF values across far western Massachusetts because of
the upslope component along the Berkshires, due to the flow aloft
remaining out of the west/northwest. NBM POPs are reasonable, but
did nudge the POPs from zero up to slight chance ~ 15 POPs along the
I-95 corridor. In addition to these nuisance rain showers there will
be breezy westerly winds. Guidance this afternoon did shows the core
of the jet slightly further south than last night, but 30 knots of
wind aloft and downsloping will likely lead to periods of wind gusts
across the east slope of the Berkshires, gusting to 40 mph during
the afternoon, elsewhere wind gusts are 25 to 35 mph. Temperatures
are seasonable, highs reach the low and middle 50s.
Sunday - Mid-level ridging and brief high pressure should allow for
a dry with more in the way of sunshine. WAA allows for a comfortable
day, highs easily return to the low-60s across much of the coastal
plain and upper-50s to 60 degrees across the interior. Depending on
how much we clear and how deep the mixing of the boundary layer, we
could over achieve these temperatures by a few degrees. Clouds
filter in during the afternoon ahead of a quick moving surface low
pressure system. Guidance is still a bit over the place with the
exact placement, but the timing appears to be late Sunday afternoon
and exiting east of the waters before dawn on Monday. QPF is around
a quarter of an inch for western zones, while eastern zones are less
than a tenth of an inch. If the ECMWF were to hold true and pass
further south of the region, those total would need to be lowered.
Did run with a blend of WPC guidance and the NBM.
Monday through Wednesday - Any lingering rain showers should be east
of the waters shortly after sunrise, setting up a nice Patriots Day
with drying conditions and warming temperatures. The bigger picture
shows surface high pressure and mid-level ridging Monday through
possibly Wednesday, this likely results in a dry pattern. And for
those who enjoy the warmer temperatures, likely to have above normal
highs and may over achieve forecast due to downsloping flow, dry
airmass, and pre-greenup. Right now, looks solid that afternoon
highs climb into the upper-60s and low-70s both Monday and Tuesday,
though its possible a few mid-70s could sneak in there.
&&
.AVIATION /02Z FRIDAY THROUGH TUESDAY/...
Forecast Confidence Levels:
Low - less than 30 percent.
Moderate - 30 to 60 percent.
High- greater than 60 percent.
00z TAF Update...
Tonight...High Confidence.
IFR-LIFR cigs/vsbys will persist through tonight. Scattered
showers into this evening become widespread overnight with
pockets of heavy rainfall and perhaps even a few embedded
t-storms. Winds shift to the SSE with gusts increasing to
between 30 and 45 knots toward daybreak. Strongest of those
winds will be near and southeast of the I-95 corridor. LLWS is
also expected.
Friday...High Confidence.
Showers with perhaps even a few embedded t-storms impact the
region during the early-mid morning hours. Drier weather by
afternoon...but a few more showers may develop especially across
western MA/CT later in the day. IFR-LIFR conditions in the
morning improve to MVFR and eventually VFR from southwest to
northeast Friday afternoon into the early evening. S wind gusts
of 30 to 45 knots in the morning diminish to between 25 and 35
knots during the afternoon.
Friday night...High Confidence.
Mainly VFR but some MVFR ceilings are possible across the
interior late Friday night. SSW winds 5 to 15 knots.
KBOS TAF...High Confidence in TAF.
LIFR cigs and vsby overnight with spotty showers, east wind at
10 knots and LLWS. Rain reaches the terminal between 07z-10z
with slight improvements to vsby, increasing from 1/4SM to 1-3SM
and cigs becoming higher end IFR. Wind shifts to the SSE and
becomes gusty, by 10z nearing 40+ knot gusts. Overnight shift
will need to monitor for an airport weather warning. These gusty
wind and LLWS continues through morning push, with improving
conditions late morning into early afternoon.
KBDL TAF...High Confidence in TAF.
LIFR cigs and IFR vsby overnight night with winds becoming gusty
around 06z-18z from the SSE 30 to 35 knots. Rain showers
overnight continues into early Friday morning with improvements
to MVFR by early afternoon, and VFR by Friday evening. LLWS is
expected during the first half of tonight, 06z-12z.
Outlook /Saturday through Tuesday/...
Saturday: Mainly VFR, with areas MVFR possible. Windy with
gusts up to 35 kt. Slight chance SHRA.
Saturday Night: Mainly VFR, with local MVFR possible. Windy
with gusts up to 35 kt.
Sunday: VFR. Breezy. Slight chance SHRA.
Sunday Night: Mainly VFR, with local MVFR possible. Windy with
local gusts up to 30 kt. Chance SHRA.
Monday through Monday Night: VFR. Breezy.
Tuesday: VFR.
&&
.MARINE...
Forecaster Confidence Levels:
Low - less than 30 percent.
Medium - 30 to 60 percent.
High - greater than 60 percent.
** Gale Warnings Overnight into Friday **
Tonight and Friday...High Confidence.
Southerly LLJ will increase to between 4 and 5 standard deviations
above normal overnight into Friday morning. An inversion will limit
some of that wind...but still expect Southerly wind gusts of 35 to
45 knots to impact the waters overnight into at least part of Friday
afternoon. Gale Warnings remain posted for all the waters. In
addition...long southerly fetch will build sees on the order of 8 to
14 feet over the open waters by Fri afternoon. In addition...areas
of fog will impact the waters at times especially this evening.
Heavy showers and a few embedded t-storms are possible overnight
into early Friday afternoon.
Friday night...High Confidence.
Gradient will weaken Fri night...but seas will be slow to diminish
and we still expect southwest wind gusts on the order of 20 to 30
knots. We will need small craft headlines for most waters once the
Gale Warnings expire.
Outlook /Saturday through Tuesday/...
Saturday: Moderate risk for Small Craft Advisory winds with
local gusts up to 30 kt. Rough seas up to 11 ft.
Saturday Night: Low risk for Small Craft Advisory winds with
gusts up to 30 kt. Rough seas up to 10 ft.
Sunday: Low risk for Small Craft Advisory winds with gusts up
to 25 kt. Seas up to 5 ft.
Sunday Night: Moderate risk for Small Craft Advisory winds with
gusts up to 30 kt. Local rough seas. Chance of rain showers,
isolated thunderstorms.
Monday: Winds less than 25 kt. Areas of seas approaching 5 ft.
Slight chance of rain showers.
Monday Night: Winds less than 25 kt. Areas of seas approaching
5 ft.
Tuesday: Winds less than 25 kt.
&&
.TIDES/COASTAL FLOODING...
* Splashover and very minor coastal flooding overnight into Fri
We continued the coastal flood advisory for the south coast...this
is for both the late evening high tide and the late Friday
morning/early afternoon high tide. Fortunately...the strongest winds
look to occur in between those high tide cycles. Still expect a 2-3
foot storm surge which will result in some splashover and very minor
coastal flooding. No significant issues are expected.
We also did continue the coastal flood statement for the eastern MA
coast for the overnight/very early Friday morning high tide. This is
mainly for lingering high astro tides and onshore flow...which may
yield splashover or at worst very minor coastal flooding.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...Wind Advisory from 2 AM to 2 PM EDT Friday for MAZ007-015>024.
Coastal Flood Advisory until 2 PM EDT Friday for MAZ020-021.
RI...Wind Advisory from 2 AM to 2 PM EDT Friday for RIZ002>008.
Coastal Flood Advisory until 2 PM EDT Friday for RIZ002-
004>007.
MARINE...Gale Warning until 8 PM EDT Friday for ANZ230>237-250-251-
254>256.
&&
$$
SYNOPSIS...Frank/Dooley
NEAR TERM...Frank/Loconto
SHORT TERM...Frank
LONG TERM...Dooley
AVIATION...Frank/Loconto/Dooley
MARINE...Frank/Loconto/Dooley
TIDES/COASTAL FLOODING...Frank
Area Forecast Discussion
National Weather Service State College PA
1134 PM EDT Thu Apr 11 2024
.SYNOPSIS...
-Periods of locally heavy rain moving quickly across the area
late this evening through tonight; southeast wind gusts up to
45 mph
-Remaining windy Friday-Saturday with gusts 40+ mph and showers
ending by Saturday night; max/min temps cooling down by 10-15F
-Showers return on Sunday; temperatures trending above average
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
Radar loop at 03Z shows moderate to briefly heavy rain showers
(and a few embedded low-topped TSRA) expanding in coverage and
racing north across the CWA as a strong southerly 55-65 kt LLJ
heads our way.
The warm, low-topped convective elements are very efficient
rainfall producers with instantaneous rates in the 3-4 inch per
hour range across parts of our far western zones where DBZ
values are in excess of 40.
989 MB sfc low was centered over western Lake Erie and its
southward trailing cold front was surging toward eastern Ohio
ATTM. A potent and slightly neg-tilt short wave ahead of the
primary mid-upr level trough axis was moving north across WVA
and VA and will enhance precip rates and coverage over the next
6 hours. Additional rainfall will average 0.75 to 1.5 inches
overnight with some small areas of 2+ inches capable of
exceeding short term FFG values and causing some localized
flooding/flash flooding problems.
The additional focus for later tonight remains on the
possibility of locally strong to severe convection associated
with increasing large scale forcing ahead of a deepening mid
level trough over the Midwest and passage of the sfc cold
front/strong southerly LLJ axis.
Favorable upper jet dynamics, and anomalous pwats (+2-3 SD)
driven northward into CPA by a southerly 50+kt 850mb jet should
result in increasing coverage of showers, as stability decreases
ahead of the approaching cold front.
The convective environment will be characterized by high shear
and low CAPE, but given the magnitude of the low level flow it`s
conceivable that even with meager instability that we could see
an isolated wind gust of 50-60 mph. The latest RAP indicates
surface-based CAPE peaking around 300 J/kg across the southeast
half of the forecast area late tonight, in conjunction with ESRH
values near 300, which could be supportive of rotating updrafts
and low-topped supercells.
As for the flooding threat, strong flow aloft and quick
movement of convection will limit the flood threat in general
and precludes watch issuance at this time. However, wet
antecedent conditions make isolated minor flooding a possibility,
especially over the central mountains, where FFG values are the
lowest. Again, ensemble mean qpf through tonight is generally
between 0.75 and 1.5 inches.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/...
WINDY FRIDAY-SATURDAY: The deep upper level trough/closed low
carved out from the eastern Great Lakes into the southeast U.S.
on Friday will lift out over the weekend. Large scale forcing
associated with the upper low combined with the arrival of sub
zero air at 850mb, steepening lapse rates, and a blustery west
wind will result in considerable shower activity Friday into
early Saturday. Showers on Friday appear to be more instability
driven, while lingering showers early Saturday are more
orographically enhanced. Temps look cold enough for rain/snow
mix over the NW mtns Friday night-AM Saturday with a coating
possible on non paved surfaces.
Gusty west-southwest winds are anticipated in the tight gradient
behind the exiting cold front Friday. However, the stronger
signal for advisory level wind gusts comes Saturday, as large
scale subsidence overspreads the region behind the exiting
trough. Bufkit soundings and EPS plumes indicate 40kt+ gusts
are possible during the late morning into the afternoon. Gusty
winds should gradually fade by Saturday night along with
lingering showers over the Allegheny Plateau.
Conditions dry out Saturday night into early Sunday before POPs
ramp up again from northwest to southeast ahead of a cold front
pushing Southeast from the Great Lakes Sunday
afternoon/evening.
After a noticeably cool down Fri-Sat with gusty winds, expect a
nice warm up to end the weekend with highs rebounding +10-15F
into the 60-75F range.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
A cold front associated with a shortwave passing to our north
will lead to the possibility of some light rain and possibly a
thunderstorm into Monday morning. This front will then move back
of the area in the Tuesday/Wednesday time frame as a warm front
and will provide another chance for some light rain. All
guidance suggests that this rainfall will be light and will not
lead to any additional flooding concerns.
Ensembles currently support above average temps Sunday into
the middle of next week. EPS mean 850mb temps surge to around
12-13C by Tue/Wed, sufficient for highs in the 75-80F range
given enough sun.
&&
.AVIATION /03Z FRIDAY THROUGH TUESDAY/...
Conditions will gradually deteriorate into the evening as
showers and thunderstorms work their way in from the south and
west. At least a few hours of IFR conditions are expected for
all of central PA overnight. A few rumbles of thunder are
possible with the heaviest rain showers, but instability is
marginal.
A LLJ will intensify over central PA through the first half of
tonight. The low levels are stable enough that there have been
some periods of sfc wind gusts 20-30 kts, but other periods
where gusts have subsided. LLWS will be a concern during
periods of lighter sfc winds. Higher gusts will be possible in
any thunderstorms overnight, especially for western airfields.
Winds will shift to the west- southwest behind a cold front
early tomorrow morning and remain gusty into the afternoon.
Most guidance shows ceilings gradually improving into the early
afternoon Friday (MVFR in the west, VFR in the east). More
stratiform precip is expected farther north and west towards
BFD. As colder air moves in after 00z Sat, rain will turn to
snow across the west and north.
Outlook...
Sat...Scattered showers with sub-VFR possible over the western
airfields (KBFD and KJST). A gusty west wind continues.
Sun...Mainly VFR, but a chance of late day showers/thunderstorms
and brief restrictions.
Mon-Tue...A few lingering showers across the west.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SYNOPSIS...Lambert/Steinbugl
NEAR TERM...Lambert/Fitzgerald
SHORT TERM...Lambert/Fitzgerald/Steinbugl
LONG TERM...Fitzgerald/Bauco
AVIATION...Colbert/Bauco
Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
938 PM EDT Thu Apr 11 2024
.SYNOPSIS...
A cold front moves east and off the Carolina coast tonight as drier
air filters into our region from the west and northwest. Very windy
conditions develop Friday into Saturday. Dry and warm weather
returns for the weekend into the middle of next week.
&&
.NEAR TERM /THROUGH FRIDAY/...
Evening Update...The stronger convec activity has tracked east of
the FA with mainly light rain showers persisting ahead of another
cold front pushing across central GA. Not expecting much development
of these cells thru the evening as the atmos has been worked over
and remains rather stable now. Winds will continue quite gusty thru
the overnight with speeds near 30 mph at times across some locales.
As of 230 PM EDT Thursday: Showers continue lifting northward across
much of the forecast area this afternoon thanks to a low pressure
system lifting northeast across the TN/OH Valley. No lightning is
currently present in this activity, but some stronger storms are
noted in eastern TN as of the writing of this AFD. Mostly cloudy
skies continue across most locations, but breaks in cloud cover are
noted across the western North Carolina mountains and the southern
SC Upstate and portions of northeast Georgia. Any breaks in cloud
cover will allow for destabilization thanks to temps ranging from
the mid to upper 60s and dewpoints ranging from the low to mid 60s
across much of the forecast area. The latest SPC mesoanalysis shows
500-1000 J/kg of SBCAPE in place as of 2pm, and projects a plume of
1500 J/kg of SBCAPE across the southern and eastern zones later this
afternoon. A plume of DCAPE is also noted from 800-1000 J/kg across
the southern and eastern zones this afternoon. The mesoanalysis also
shows 60-70 kts of bulk shear over the area, with 0-1 km shear at 30
kts over the eastern half of the CWA this afternoon. All this to
say, any areas that see breaks in cloud cover will have the
potential to see isolated strong to severe storms develop. The main
threat with any storm that manages to become severe may produce
damaging wind gusts. However, an isolated, brief tornado cannot be
entirely ruled out this afternoon, especially over the NC Piedmont
along/near I-77. Thus, SPC`s Day 1 Marginal Risk looks well placed.
The severe threat will end by the early evening hours with the loss
of daytime heating and as the bulk of activity pushes east of the
forecast area. Highs this afternoon will climb a few degrees above
climo. Breezy S/SW winds will continue through this evening.
Rain chances will linger this evening into late tonight, especially
across the western North Carolina mountains thanks to a secondary
cold front tracking across the region. Thus, maintained chance PoPs
through midnight east of the mountains, with likely to categorical
PoPs across the western North Carolina mountains. Have Pops ramping
down to chance after midnight across the western North Carolina
mountains. Winds will gradually increase across the mountains
overnight becoming gusty while gusts east of the mountains will
gradually decrease throughout the overnight hours. With gusts
expected to reach advisory criteria (45-55 mph), a Wind Advisory was
issued for most of the North Carolina mountains starting midnight
tonight. Cloud cover will gradually diminish east of the mountains
overnight into early Friday morning becoming clear to mostly clear.
Lows tonight will end up a few degrees above climo despite the
decreasing cloud cover.
Cloud cover will linger across the western North Carolina mountains
through Friday while mostly sunny skies prevail elsewhere. Shower
and thunderstorm chances should return along the NC/TN border Friday
afternoon thanks to NW flow. Some of this activity may break
containment of the mountains, per the HRRR and NAMNest, but
confidence on this is low at this time. Thus, have highest PoPs
confined to the NC/TN border with lower PoPs elsewhere. Highs on
Friday will end up a few degrees below climo behind the departing
cold front. Winds will once again increase on Friday thanks to a
tight pressure gradient so the Wind Advisory will remain in place
for portions of the North Carolina mountains through Friday evening.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
As of 155 pm Thursday: Long wave trough axis will be in the process
of moving east of the area at the start of the period. Persistent,
rather strong/deep NW flow acting on lingering low level moisture
across the TN Valley into the western slopes of the southern
Appalachians to yield continued potential for upslope showers near
the TN/NC border. However, chance PoPs will steadily ramp down
through Fri night, as flow (finally) steadily weakens and moisture
depletes. However, conditions will remain gusty over the mountains
Fri night into at least the first half of Saturday. While critically
low RH is expected to be primarily confined to the Piedmont and
foothills, fire danger will nevertheless be enhanced across much of
the CWA during the daylight hours Saturday.
As trough progresses away from the East Coast during the latter half
of the weekend, the surface gradient will finally relax and winds
become tame. While RH is again expected to be quite low Sunday
afternoon, winds will be well below critical levels. The bigger
story will be the rather dramatic warm-up resulting from height
falls and return SW flow. After near-normal conditions that are
expected Fri night through Sat night, temps are expected to soar to
around 10 degrees above climo Sun afternoon, with widespread lower
80s expected across the Piedmont and foothills, while even the major
mountain valleys are expected to push the 80 mark.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
As of 210 pm Thursday: An upper ridge will build strongly across the
central Conus during the extended period...downstream of the next
major West Coast storm system. This will result in continued very
warm conditions through the period, with temps expected to range
from 10-12 degrees above climo...making it feel more like
mid-to-late May than mid-April. Conditions will otherwise remain
inactive over our area, with slowly moistening conditions expected
through the week. The western storm system is expected to kick out
across the Great Plains early in the week, but the strong ridge is
forecast to deflect this feature into the Great Lakes and Ontario
during mid-week. This may drag an occluding frontal system toward
our area for days 6/7, but indications in the global models is that
this will have little-to-no effect on our sensible weather, and only
token 20-30 PoPs are featured along the TN/NC border during this
time frame.
&&
.AVIATION /02Z FRIDAY THROUGH TUESDAY/...
At KCLT and elsewhere: Convective activity continues across the area
this evening, yet only isol cells are producing lightning. Have
included thunder mention at KCLT and KHKY thru 02z. Confidence
remains low across the other terminals for a much more than a rain
or vicinity shower mention this evening. Expect lowering CIGS likely
into the MVFR range, with passing activity this evening into the
early overnight, them a return of VFR conds thru the TAF period
across all sites thru the period. Southwesterly to westerly winds
remain gusty and increase in strength later in the period. Winds at
KAVL will begin the period sw/ly then shift nw/ly arnd midnight.
Outlook: Wind gusts will gradually taper off Friday night east of
the mountains, but will remain gusty across the North Carolina
mountains through Saturday. VFR conditions will persist this weekend
and early next week as high pressure builds across the terminals.
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...None.
NC...Wind Advisory until 9 PM EDT Friday for NCZ033-048>050-052-053-
059-063>065-501-503-505-507-509.
SC...None.
&&
$$
SYNOPSIS...DEO
NEAR TERM...AR/SBK
SHORT TERM...JDL
LONG TERM...JDL
AVIATION...SBK
Area Forecast Discussion
National Weather Service Marquette MI
655 PM EDT Thu Apr 11 2024
.KEY MESSAGES...
- Deepening low pressure tracking across the Lower Great Lakes
region tonight and into Quebec on Friday will bring gusty
north to northwest winds to 45 mph to the eastern forecast
area on Friday as well as high end gales to eastern Lake
Superior.
- Periods of showers into next week, including tonight into
Friday morning, late Saturday afternoon and night, and then
Monday through Thursday.
- Temperatures on most days will be above normal through the
first half of next week.
&&
.SHORT TERM /THROUGH TONIGHT/...
Issued at 348 PM EDT Thu Apr 11 2024
Current RAP analysis shows a few mid level shortwave troughs that
converge tonight over the Great Lakes. The northernmost shortwave is
over northwestern Ontario, the middle shortwave is currently digging
southeast into Iowa, and the southernmost shortwave is situated over
the Tennessee Valley. The northern two shortwaves are expected to
move east-southeast into the Upper Great Lakes/WI while the southern
shortwave lifts northeast toward the Lower Great Lakes into tonight.
Meanwhile, a weak sfc trough and cold front over central Upper
Michigan will move east across the rest of the UP through this
evening. In combination with a lake breeze off Lake Superior this
afternoon, this is supporting some isolated showers that will
continue to expand east into the evening hours, possibly accompanied
by some rumbles of thunder over the interior west where the best
instability is.
The sfc low associated with the southern shortwave is currently
analyzed over the Ohio Valley. Showers will continue to build over
the eastern UP tonight as the low lifts northeast into southern
Ontario, strengthening to a HREF mean of 980mb with the support of
the left exit region of the upper level jet. Q-vector convergence
with this low is confined to the eastern UP tonight, so the better
accumulations are expected over the east, aided by upslope northwest
flow. That being said, accumulations are expected to stay fairly low
around 0.1 to 0.20". The strengthening low will tighten the pressure
gradient overhead, increasing northwest winds tonight with gusts up
to 20-30 mph late. Lows tonight will settle into the 30s to low 40s,
colder near Lake Superior.
&&
.LONG TERM /FRIDAY THROUGH THURSDAY/...
Issued at 506 PM EDT Thu Apr 11 2024
An active period is on the way thru next week, resulting in frequent
opportunities of rainfall. Split flow will largely dominate, but
phasing of northern and southern stream energy will lead to
deepening low pres tracking across the Lwr Great Lakes region
tonight into Fri morning, then into se Canada Fri night. While that
occurs, a vigorous wave will fall out of the main branch of flow,
dropping from the ne Pacific and reaching the sw U.S. on Sun. To the
n, the main stream of flow will temporarily trend more zonal,
sending at least a couple of waves along the vcnty of the
International Border Sat thru Mon. Then, back to the w, the wave
over the sw U.S. on Sun will get kicked ne early next week by
another wave dropping from the Gulf of AK into the western U.S. The
wave will support a strong low pres system over the Plains that will
then weaken as it tracks thru the Upper Mississippi Valley, Upper MI
and into northern Ontario during Mon night thru Wed. The wave that
drops into the western U.S. may go on to support continued active
weather downstream into the Great Lakes late next week. Under this
active pattern, expect showers into Fri with the first system. After
a brief break early in the weekend, the waves tracking along the
vcnty of the International Border will support at least sct shra
late Sat aftn and night. While some shra may return during the day
on Mon, attention turns to the strong low pres developing over the
Plains. This low will bring widespread shra into Upper MI for Tue.
Shra will likely linger on Wed, but with diminished coverage. One or
maybe two more low pres waves may lift thru the Great Lakes late
next week as western troffing progresses downstream, providing
additional opportunities of pcpn. As for temps, expect temps to be
on the warm side of normal, except on Fri as gusty n to nw winds
drive cooler air into the area on the backside of the deep low
lifting thru the Great Lakes region. Then, in the wake of the low
pres moving across the area late Tue/Wed, mid-level troffing will
will reach the Upper Great Lakes late next week thru the weekend,
suggesting at least a short period of slightly blo normal temps at
that time.
On Fri, mid-level trof axis will run from northern Manitoba to
eastern Lwr MI to start the day, and associated deep sfc low pres
will track from vcnty of Georgian Bay into Quebec. While steadier
associated rainfall will be occurring over the eastern U.P. early,
additional shra will occur farther w under the mid-level troffing
which will feature a weak wave dropping into the Upper Great Lakes.
Track of that wave will provide best chc of shra over the w. In the
aftn, all of the pcpn will gradually end as height rises begin and
drier air advects into the area. Expect a windy day, especially e
half. Fcst soundings suggest mixing will easily support gusts to 35-
40mph with potential for gusts up to 45-50mph. While NBM
probabilities of gusts to at least 45mph are lower than viewed
yesterday, only up to around 10pct instead of 25pct over the eastern
fcst area, fcst soundings suggest a much higher risk, warranting
issuance of a wind advy. That potential will increase if clouds thin
out some to allow more solar insolation as is suggested by some of
the model guidance. Thinning clouds are more likely thru the central
U.P. Wind advy will run from Alger/Delta eastward. With potential of
less cloud cover in the central U.P., the prospect for more heating
and resulting higher mixing may require an expansion of advy to
another tier of counties westward. That will need to be reassessed
in later forecasts. With the gusty nnw winds on Fri, temps will
range from the low/mid 40s F w and n to the lwr 50s s central.
Sfc high pres ridge approaches Fri night. Normal decrease in winds
under increasing nocturnal stability will be aided by the weakening
pres gradient. This ridge will shift across Upper MI on Sat.
However, a wave tracking e along the vcnty of the International
Border will spread waa/isentropic ascent toward Upper MI by evening.
Combined with an advancing sharp 850mb theta-e gradient and healthy
upper diffluence from the right entrance of 100kt upper jet streak
extending from northern Lake Superior to the Lwr Great Lakes, sct
shra may begin to spread into nw Upper MI after 21z Sat. There will
be abundant low-level dry air to overcome, but given the fairly
strong forcing, will include 20-30pct chc of shra 21z-24z. Sct
-shra will then streak across the fcst area Sat night, ending by
sunrise Sun. Pool of elevated instability builds toward Upper MI for
Sat night, and it may be just sufficient toward the MI/WI stateline
for a rumble or two of thunder. Following the shra Sat night, Sun
will turn out to be nice mid Apr day under increasing sun. Highs on
Sun will be well into the 60s F across the interior w half.
On Mon, the nearly zonal flow vcnty of the U.S./Canada border will
be buckling as shortwave drops out of the Gulf of AK into the nw
U.S. Downstream, upper jet will be forced to lift n, again placing
right entrance upper diffluence over the area. There are also hints
of a weak shortwave tracking toward Upper MI. So, a mention of pcpn
is warranted at least across the w, but only 20-30pct chc for now.
Attention then turns to the wave over the sw U.S. that gets kicked
ne by the shortwave dropping thru the nw U.S. Sfc response will be a
deep sfc low organizing to the lee of Rockies. This low will reach
peak depth over the Plains, then it will weaken as it lifts ne to
Upper MI and to northern Ontario. With a good surge of gulf moisture
ahead of it (precipitable water increases to 225-250pct of normal),
expect shra, maybe some thunder, Mon night thru Tue night, but
especially Tue/Tue night. Will be breezy as well. Shra will linger
on Wed. A wave lifting out of the western trof will lead to shra
continuing on Thu as well.
&&
.AVIATION /00Z TAFS THROUGH 00Z SATURDAY/...
Issued at 655 PM EDT Thu Apr 11 2024
VFR conditions will continue into most of the overnight, but cigs
will deteriorate to MVFR levels at all TAF sites late tonight in the
wake of a cold front. MVFR cigs are expected late tonight into
Friday morning; highest confidence for IFR cigs at SAW. While the
CMX and IWD TAFs remain in MVFR tonight into Friday. Winds will
become strong out of the northwest late tonight, continuing on
Friday as low pressure system lifts north through the Lower Great
Lakes. Gusts up to 20 kts are expected at IWD with up to 30 to 35
kts at CMX and SAW.
&&
.MARINE...
Issued at 506 PM EDT Thu Apr 11 2024
Deepening low pres will lift into southern Ontario tonight and to
near Georgian Bay by Fri morning. In response, N to NNW winds will
ramp up tonight, reaching 35-40kt gales late tonight/early Fri
morning across the e half of Lake Superior. Winds will increase
further to 40-45kt across the eastern portion of the lake Fri
morning/aftn. Internal probabilistic guidance indicates a 20pct chc
of peak gusts reaching storm force over the far se part of the lake
btwn Grand Marais and Whitefish Pt. As the low pulls away and high
pres ridge arrives on Sat, winds will diminish to blo gale force
late Fri night and to 20kt or less during Sat. Winds will then
remain mostly under 20kt thru Sun. Another deep low will begin to
organize on the lee side of the Rockies late on Mon. Easterly winds
will begin to increase late Mon with gusts to 25-30kt by late Mon
night. Ensemble guidance indicates a 70-90pct chc of easterly gales
of 35-40kt Tue aftn and night across much of Lake Superior. The
gales may linger into early Wed.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
Wind Advisory from 8 AM to 8 PM EDT Friday for MIZ006-007-013-
014-085.
Lake Superior...
Small Craft Advisory from 2 AM to 8 AM EDT Friday for LSZ248.
Small Craft Advisory from 2 AM EDT /1 AM CDT/ to noon EDT /11
AM CDT/ Friday for LSZ240.
Small Craft Advisory from 2 AM EDT /1 AM CDT/ to 5 PM EDT /4
PM CDT/ Friday for LSZ241>243.
Small Craft Advisory from 1 AM to 8 AM EDT Friday for LSZ244-
245.
Gale Warning from 8 AM to 5 PM EDT Friday for LSZ244-264.
Gale Warning from 8 AM to 7 PM EDT Friday for LSZ245-248-265.
Small Craft Advisory from 5 AM to 11 PM EDT Friday for LSZ246-
247.
Small Craft Advisory from 2 AM to 5 AM EDT Friday for
LSZ249>251.
Gale Warning from 5 AM Friday to 2 AM EDT Saturday for LSZ249-
250-266.
Gale Warning from 5 AM Friday to 8 AM EDT Saturday for LSZ251-
267.
Lake Michigan...
Small Craft Advisory from 2 AM to 8 AM EDT Friday for LMZ221-
248-250.
Gale Warning from 8 AM to 8 PM EDT Friday for LMZ221-248-250.
&&
$$
SHORT TERM...Jablonski
LONG TERM...Rolfson
AVIATION...07
MARINE...Rolfson
Area Forecast Discussion
National Weather Service New York NY
1036 PM EDT Thu Apr 11 2024
.SYNOPSIS...
A cold front approaches tonight and moves through Friday as its
associated low pressure over southeastern Canada lifts north. A
series of surface trough moves through Friday night into
Saturday. A weak low moves through on Sunday. High pressure
takes over Monday, potentially followed by a warm front front
moving in late Tuesday into Wednesday.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
For this update, temperatures and dewpoints have been adjusted
based on the latest observations. Otherwise, the forecast
remains mainly on track.
The near term starts off with the area warm sectored and a dry
slot moving through will help to limit the rain and the
potential for flooding. WPC has lowered their excessive rainfall
category of slight for western Orange county to marginal. Thus,
the main threat for flooding should be limited to minor
nuisance and poor drainage flooding tonight into Friday. The
chance for showers increases overnight as a cold front
approaches from the west. There are some signs that a convective
line forms just ahead of the cold front late tonight around the
same time as the low level jet increases (see below) in the
CAMs and forecast soundings do show some elevated instability as
dew points rise into the low to mid 50s range. Will continue to
mention an isolated thunderstorm from around 2 am to 8 am
Friday. It is this line that will be associated with some
moderate to briefly heavy rainfall for western areas of the
forecast area late tonight.
A low level jet will increase tonight to 70 to 80 kt at around 925
hPa. This would normally bring some higher winds to the surface
but it is coupled with a low level inversion which will limit
some of this wind from mixing down to the surface. However, the
NBM is showing an 80% chance or higher for wind gusts of 46 mph
or higher from around midnight through 6 am Friday.
Additionally, the HRRR has been showing 10 m gust potential of
50 to 60 mph. Don`t think gusts will be that high, and this may
only be for an hour or two based on the HRRR, but it would be
enough to issue a Wind Advisory for Long Island (including
Queens and Brooklyn) and coastal Connecticut for gusts of 45 to
50 mph and an isolated gust of 50 to 55 mph is possible from
midnight tonight through 6 am Friday.
With area warm sectored and thus southerly flow established across
the area, coupled with clouds, temperatures will not drop much. In
fact, in some areas, they may rise slightly overnight. Lows are
expected to be in the 50s for much of the region.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY/...
The moderate to locally heavier rain should push east of the
forecast area by mid morning Friday, but another round of light
showers and possibly a thunderstorm will move through western
areas at the same time in association with a surface trough.
Chances for precipitation should lower during Friday afternoon
(though it will not be completely dry) as the main forcing for
the surface trough lifts north along with the low pressure. Any
shower or thunderstorm may be associated with gusty winds.
Speaking of this low pressure which is associated with the cold
front in southern Canada, it will strengthen slightly Friday
morning as it heads into southern Canada. So, although not as
windy as Thursday night, it will be a breezy day. Gusts up to 35
mph are expected as heights lower and more ideal mixing takes
place as lower heights build across the area with steeper lapse
rates and a trough swings through. A strong SW flow will then
become more westerly Friday night and into Saturday.
Another surface trough, along with the upper level low, which
transitions into an upper level shortwave, will move approach
and move through portions of the forecast area Friday night,
bringing another round of showers, mainly for areas north and
west of New York City.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
Light, isolated showers (mainly for northern zones) may still linger
in the vicinity Saturday morning as an impactful low pressure system
exits into Canada, clearing by Saturday afternoon with a cold front.
There will still be a bit of a pressure gradient around on Saturday
keeping things breezy until Saturday night when winds finally
diminish.
A second cold front on Saturday will aid in clearing clouds and any
lingering precip, as well as usher in cooler air with highs on
Saturday in the mid/low-50s. This will be supported by a strong
trough centering itself over the region.
A trough over the region exits to the east Saturday night into
Sunday morning with the upper-level pattern becoming zonal on Sunday
as surface high pressure noses in from the south. The zonal west to
east flow helps advect in higher moisture and mid-level energy,
leftovers from a weak low that moved into the Great Lakes. Unlike
yesterday, all models have now come into agreement on this solution.
We should see some scattered showers as this moves through on
Sunday. Isolated thunderstorms are also possible as there could be
some elevated instability, weak as it may be. A due north cold front
will clear clouds and precip Monday morning.
The upper-level pattern remains zonal through Monday before a strong
ridge builds Tuesday into Wednesday. This will lead to sunnier
weather and temperatures warming into the mid-70s to upper-60s,
supported by warm air advection aloft.
The ridge remains in place on Tuesday, though a strong upper-level
jet develops aloft with a warm front placing itself over the area
from a low in the northern Great Plains/Western Great Lakes. These
will act together to increase cloud cover through the day on
Tuesday, but expected warmer temperatures to remain due to warm air
advection aloft. This warm front which eventually becomes a stalled
boundary will lead to rain chances Tuesday night into Wednesday.
&&
.AVIATION /03Z FRIDAY THROUGH TUESDAY/...
A cold front passes through the area Friday.
IFR to LIFR with showers. There is a period where thunder is
possible late tonight into early Friday morning, but confidence
is too low in coverage and occurrence to add to the TAF.
Marginal improvement Friday with VFR likely returning in the
afternoon but ceiling improvements expected to be slow
occurring.
SE-S winds increase this evening with gusts 25-30kt later this
evening with gusts up to 40kt possible overnight. LLWS begins
this evening and peaks overnight/early Friday morning. SW gusts
still around 30 kt Friday morning, then subsiding a little in
the afternoon
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Amendments likely for ceilings and visibilities. Low confidence
in any thunder, will likely be isolated across the area.
OUTLOOK FOR 00Z SATURDAY THROUGH TUESDAY...
Friday night: VFR with brief MVFR/showers possible. SW-W winds
gust around 25kt.
Saturday: Chance of showers mainly NW of the NYC metros, mainly
VFR. W-NW winds G25-30kt.
Sunday: Mainly VFR. Chance of MVFR and showers in the afternoon.
SW-W winds G20-25kt.
Mon and Tue: Mainly VFR.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90
&&
.MARINE...
SSE gales are expected to develop during this evening and
spread NE across the waters late in the night, with gusts up to
45 kt. An isolated gust to 50 kt is possible. Gale conditions
should give way to small craft conditions from west to east late
Friday morning into Friday afternoon on a SW wind. Small craft
conditions will linger through Friday night with a WSW wind
gusting mainly 25 to 30 kt.
Seas will build quickly tonight with 10 to 15 ft ocean seas by
late tonight into Friday morning. Waves over the sound will
rise to 3 to 5 ft, with up to 9 ft possible for the extreme
eastern sound. Waves diminish Friday afternoon, but remain above
5 ft for the ocean waters and the eastern sound and even into
the entrance of the harbor through Friday night.
&&
.HYDROLOGY...
A period of moderate to briefly heavy rain is expected tonight
and into early Friday morning for eastern sections. At this
time the flooding risk from rainfall is limited despite the fact
that antecedent conditions/soil moisture remains rather high.
Due to the progressive nature of the system it is likely that
any flooding would be more of the minor, nuisance and urban-poor
drainage variety. WPC maintains a marginal risk of excessive
rainfall across the entire forecast area. Between 3/4 and 1 1/2
inches of rain is forecast, with the highest across inland
southern Connecticut.
&&
.TIDES/COASTAL FLOODING...
There has not been a significant change to the forecast thinking
this afternoon. Strengthening SE-S flow with a storm system tonight
into Friday morning will likely force widespread minor to locally
moderate coastal flooding. With increasing SE gusty flow, waves will
increase in height, setting up a widespread minor coastal flood
event for the forecast all area shorelines. Some localized moderate
coastal flooding is forecast, especially for some of the South Shore
Bays with tonight`s high tide cycle. Advisories are now in effect
everywhere this evening into early Friday morning`s high tide cycle.
One fly in the ointment with this forecast is the delay in the peak
surge timing relative to high tide, especially across the eastern LI
Sound and Atlantic facing south shore locations. Should peak surge
values come in a bit later, toward 06-09Z, as per the newer 12Z
guidance, some locations will not reach forecasted levels.
Winds will remain southerly through the event, becoming more
southwest toward daybreak Friday, as the surge begins to wane.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...Coastal Flood Advisory until 5 AM EDT Friday for CTZ009-010.
Wind Advisory from 2 AM to 8 AM EDT Friday for CTZ009>012.
Coastal Flood Advisory until 4 AM EDT Friday for CTZ011-012.
NY...Coastal Flood Advisory until 5 AM EDT Friday for NYZ071-073-
078-176-177.
Wind Advisory from 2 AM to 8 AM EDT Friday for NYZ075-078>081-
176>179.
Coastal Flood Advisory until 2 AM EDT Friday for NYZ072-074-
075.
Coastal Flood Advisory until 6 AM EDT Friday for NYZ079.
Coastal Flood Advisory until 5 AM EDT Friday for NYZ080-081.
Coastal Flood Advisory until 3 AM EDT Friday for NYZ178-179.
NJ...Coastal Flood Advisory until 2 AM EDT Friday for NJZ006-104-
106-108.
MARINE...Gale Warning until 4 PM EDT Friday for ANZ331-332-340-345.
Gale Warning until noon EDT Friday for ANZ335-338.
Gale Warning until 6 PM EDT Friday for ANZ350-353-355.
&&
$$
SYNOPSIS...JP/BR
NEAR TERM...JP/BR
SHORT TERM...JP
LONG TERM...BR
AVIATION...JC
MARINE...JP/BR
HYDROLOGY...JP/BR
TIDES/COASTAL FLOODING...
Area Forecast Discussion
National Weather Service Blacksburg VA
741 PM EDT Thu Apr 11 2024
.SYNOPSIS...
A complex low pressure system over the eastern United States
will produce showers and thunderstorms as a cold front pushes
off the Mid Atlantic coast by Friday morning. Gusty wind and
colder temperatures will follow this system for Friday into
Saturday with some showers in the mountains. Mainly dry and
warmer weather is on tap for the beginning of next week.
&&
.NEAR TERM /THROUGH FRIDAY/...
As of 725 PM EDT Thursday...
Key Message:
1. Tornado Watch until 11pm for portions of NW NC into southern
VA. Chance for severe storms with isolated tornadoes, locally
heavy rain, and gusty wind.
2. Wind Advisory remains in effect for Western Greenbrier
3. Wind advisory may be expanded into the southern Blue Ridge
for tonight
Low level environment favors spinning with 0-1km SRH 200-350.
Per coordination with SPC have a Tornado Watch for southern VA
into NW NC til 11pm. Once sun sets, instability will weaken but
shear remains high into the evening ahead of the front over the
piedmont, so will need to heed warnings. Have already had a
confirmed tornado in Wilkes County.
Previous discussion...
Not seeing much erosion of the stratus in satellite imagery over
Virginia, but ans area of clearing over Georgia and South
Carolina was advancing north. HRRR and HREF showed the time
range from 20Z/4PM through 03Z/11PM. The convective allowing
models show the potential for discrete supercells developing in
the foothills of North Carolina and tracking into central and
eastern Virginia and North Carolina.
The 12Z RNK sounding had about 300 J/kg of Convective Available
Potential Energy. But limited cooling at mid level is expected
and for now stratus and rain are hampering warming at low
levels so available instability may limit coverage of
thunderstorms this afternoon and evening.
Cold air aloft arrives on Friday. Bufkit forecast soundings
showed large lapse rates and much of the elevated CAPE above
the freezing level. Have maintained thunder during the daytime.
Low level jet shows a maximum just behind in the front in the
50 to 60 knot range out of the west. This brings wind gusts in
the higher elevations of the southern Blue Ridge. Gusty wind
continues through Friday. This also supported by strong cold air
air advection and healthy pressure rises. Daytime mixing Friday will
also produce another surge in wind.
Temperatures will hold in the 50s and 60s until the cold front
passes through in the late evening. 850MB temperatures drop to
near zero be Friday morning.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY NIGHT/...
As of 1245 PM EDT Thursday...
Key Messages:
1) Confidence is high for gusty winds persisting into Saturday
before fading by Saturday night.
2) A low chance of showers and thunderstorms returns by late
Sunday for southeast West Virginia.
Gusty winds will continue into Friday night and Saturday due to
a strong pressure gradient between low pressure deepening in
eastern Canada and high pressure in the lower Mississippi River
Valley. There may be gusts approaching advisory criteria along
the southern Blue Ridge. The wet soil from recent rainfall could
allow a few trees and power lines to be blown down more easily.
Upslope rain showers will gradually fade from Boone to
Lewisburg by Saturday morning, and there may be snow flurries
along the higher elevations of western Greenbrier County before
the moisture completely dissipates. High pressure should provide
lighter winds and drier weather for the remainder of Saturday
and through Saturday night.
An upper level ridge will build eastward from the southern
Plains to the Gulf Coast on Sunday. As high pressure drifts
offshore, the flow should turn towards the southwest. The rising
heights aloft and the increasing warm air advection should
boost temperatures notably above normal with widespread highs in
the 70s by Sunday afternoon. Meanwhile, a weak frontal boundary
will dive southeastward from the Great Lakes, but the building
upper level ridge will halt any further progress southward from
Pennsylvania. Some showers and thunderstorms may spill into
central West Virginia by Saturday evening, so a low chance of
rain exists for the Interstate 64 corridor. Elsewhere, dry
weather is expected for Sunday and Sunday night. Temperatures
will stay elevated during Sunday night with lows only falling
into the 50s.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
As of 1206 PM EDT Thursday...
Key Message:
1) Mainly Dry With Well Above Normal Temperatures
Forecast models agree in a building a ridge and 8h temps across
our area next week. Warm front close to the area Monday allows
for a few showers/storms but in general frontal systems will be
to our northwest through the period with limited chances for
showers or storms. Going to be more like early summer at times
with high temperatures in the 80s by midweek.
Highs and lows will be running 10-20 degrees above normal.
Forecast confidence is high on warmer pattern and moderate on
rain chances which will be mainly confined to the mountains.
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
As of 730 PM EDT Thursday...
NOTE: Have AMD NOT SKED at KDAN due to inconsistent wind data
outages.
Flying conditions will be poor at times this evening as
shower/storm activity will be widespread. Looking at potential
strong/severe storms along/east of a line from ROA-MWK through
03z.
Ceilings will rise to VFR east of the Blue Ridge with the west
wind behind the front.
Cold air aloft arrives on Friday. Bufkit forecast soundings
showed large lapse rates and much of the elevated CAPE above
the freezing level. Have maintained thunder during the daytime.
Some of the showers and thunderstorms will spread east into the
piedmont of Virginia and North Carolina during the afternoon but
kept precip out of the forecast in the east as will likely be
scattered.
Low level jet shows a maximum just behind in the front in the
50 to 60 knot range out of the west. This brings wind gusts in
the higher elevations of the southern Blue Ridge. Gusty wind
continues through Friday. This also supported by strong cold air
air advection and healthy pressure rises. Daytime mixing Friday will
also produce another surge in wind.
Forecast confidence is average.
OUTLOOK...
Friday night and Saturday, expect gusty northwest wind on the
west side of the exiting system with scattered to numerous upslope
showers and isolated thunderstorms for the mountains. Most
areas will trend to VFR east of the Blue Ridge.
By Sunday, VFR conditions are expected for all locations along
with weakening winds.
By Monday, a weak system may bring a return of some showers and
patchy sub-VFR conditions to Southeast West Virginia. Elsewhere,
VFR conditions are expected.
Mainly VFR through Tuesday with a few showers/storms possible
north of LWB-HSP.
Confidence in the above extended aviation scenario is moderate.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...Wind Advisory from midnight tonight to 9 PM EDT Friday for
VAZ009-012>020-022>024-032>035.
NC...Wind Advisory from midnight tonight to 9 PM EDT Friday for
NCZ001>003-018-019.
WV...Wind Advisory until 9 PM EDT Friday for WVZ508.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS/WP
SHORT TERM...PW
LONG TERM...WP
AVIATION...AMS/WP
Area Forecast Discussion
National Weather Service Sacramento CA
123 PM PDT Thu Apr 11 2024
.Synopsis...
Mild and mostly dry weather continues through today. Slight chance
of isolated thunderstorms this evening with more unsettled weather
Friday through Sunday bringing light to moderate mountain snow,
rain, and gusty winds.
&&
.Discussion...
Looking at satellite late this morning, weather conditions
continue to be relatively benign outside of scattered clouds over
the Sierra and portions of the Coastal Range. Our upper-level
ridge that has provided us our recent warm, dry stretch slides
eastward as an upper-level low from the Gulf of Alaska makes its
way down towards the Central CA coast today before moving inland.
Today will the last warm day of the week with temperatures in the
low 80s across the Valley cooling to the low 60s by Sunday as more
inclement weather and cloud cover develops.
We will start seeing initial impacts from the trough today as
there is the potential for isolated thunderstorms across the
Northern Sacramento Valley, mainly east of Redding. NBM
probability shows a 10-20% chance of thunderstorm development for
areas north of Red Bluff in the Northern Sacramento Valley. There
isn`t an overwhelming amount of conditions supporting substantial
thunderstorm development with the shear profile being west-
southwesterly, and the incoming system being a drier system.
However, there may be enough moisture advection, southerly
component to the winds, and energy from the system to support
very localized showers and an isolated thunderstorm. With any
storm that develops, small hail, lighting, brief heavy rainfall,
gusty winds, and lightning are all possible impacts. Current
higher resolution models don`t indicate any impactful development
with current HRRR maintaining our drier pattern today.
With the incoming system, light to moderate snowfall is
forecasted, beginning late night Friday through Sunday morning
across the mountains. Snow levels initially will be 5000 to 6750
feet lowering to 3500 to 5000 feet by Saturday afternoon. Impacts
will be minor with NBM probability showing a 10-40% chance of
LTDAFDSTOexceeding 4 inches over the Sierra, up to 65% south of
Hwy. 50 and near the Lassen National Park Area. Heaviest snowfall
will be Saturday morning for areas south of Hwy 50. and Saturday
night into early Sunday morning for areas north of Hwy 50.
Precipitation will start along the west side of the Valley,
moving down the mountains and Valley throughout Friday evening.
Periods of light to moderate rainfall will continue through Sunday
morning but impacts will be minor. Friday brings another chance
for thunderstorm development (15-30% chance), primarily south of
I-80 and over the Coastal Range. Forecasted totals from Friday
morning to Sunday morning is 0.50-1.00" in the Valley with
0.75-1.50" over the foothills and mountains. NBM probability shows
a 10-45% chance of exceeding 0.50" with a 50-90% chance of the
foothills and mountains, highest north of I-80 and in the Northern
Sacramento Valley. Rain in the Valley tapers off Saturday
evening, with dry conditions by Sunday late morning.
Sunday will see lingering showers over the foothills and light
snowfall over the Sierra with conditions quietening by Sunday
night.
&&
.EXTENDED DISCUSSION (Monday THROUGH Thursday)...
Ensembles still point to northerly flow developing as a ridge
moves through NorCal. With this, temperatures warm with drying
conditions over the area. Monday afternoon highs warm to upper
60s, low 70s across the Valley and continue through much of next
week. Gusty north winds are expected along and west of I-5 with
gusts 15 to 35 MPH, beginning early Tuesday morning. Strongest
winds look to be Tuesday afternoon through Wednesday afternoon
before tapering off by Thursday morning. NBM probabilities show a
30 to 60 percent chance of wind gusts exceeding 40 MPH over the
Sierra and along and west of I-5, north of Sacramento Tuesday and
Wednesday.
&&
.AVIATION...
VFR conditions next 24 hours except vicinity except brief local
MVFR possible isolated showers or thunderstorms over mountains
north of KRDD 00Z-06Z Friday, and then more widespread scattered
shower potential after 12z and isolated thunderstorms after 18z.
Surface winds generally less than 12 kts through 18z Friday,
followed by breezy southerly winds 12-20 kts with gusts up to
22-30 kts.
&&
.STO WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$