Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 11/17/24
Area Forecast Discussion
National Weather Service Binghamton NY
950 PM EST Sat Nov 16 2024
.SYNOPSIS...
High pressure overhead will lead to dry conditions through
Sunday. The gusty west to northwest winds in place will
gradually ease this evening. Some showers are possible later
Sunday night into early Monday, mainly across Central New York
then shower chances increase toward midweek.
&&
.NEAR TERM /THROUGH SUNDAY NIGHT/...
950 PM Update...
Latest 01z HRRR has backed off on the development of widespread
stratus development overnight, while the 00z 3km NAM still
suggests fairly widespread fog/stratus developing over CNY and
the northern tier of PA. Thus far, the stratus cloud deck over
Western NY/PA is struggling to expand eastward, with occasional
scattered to broken clouds developing over the I-90 corridor
late this evening. Blended in some of the latest guidance for
the overnight cloud cover, which decreased it slightly...still
only low to moderate confidence on just how widespread low
clouds and/or fog will be tomorrow morning.
635 PM Update...
No significant changes to the near term forecast at this time.
Skies are clear this evening, but model guidance is still
hinting at a developing stratus cloud deck and patchy fog
overnight into Sunday morning for much of Central NY and
portions of NE PA. Confidence on the development and areal
extent of these clouds is moderate at best; used a blend of the
HRRR and 18z 3km NAM to create the sky cover forecast. Also took
down cloud cover slightly for midday and Sunday afternoon as the
low clouds dissipate and should be replaced by sct high clouds.
temperatures will be cool tonight where skies remain clear the
longest, getting down into the 20s...but holding in the low to
mid-30s for the Twin Tiers, Finger Lakes and Wyoming Valley.
Will issue an SPS for low RH values and fire weather concerns
over the Catskills tomorrow late morning and afternoon. Luckily
winds are forecast to be much lighter on Sunday, only 3-8 mph.
330 PM Update...
Surface high pressure will be settling in overhead tonight
along with strong ridging aloft, leading to a dry and seasonably
chilly night. However, low level moisture at 925 mb is expected
to advect back in over the Finger Lakes region, Southern Tier
and into portions of NE PA. This can lead to at least a broken
lower stratus deck through this area similarly to what was seen
this morning, so cloud cover was increased from the NBM early
tomorrow morning. East of I-81 is expected to remain mainly
clear and with winds becoming light, and the uptick in low level
RH, there may be a few areas of patchy fog in the valleys. Lows
tonight will be in the upper 20s to the mid 30s.
Dry conditions will remain in place tomorrow with high pressure
still in control. Some sunshine is expected to give way to an
increase in clouds during the afternoon. Winds will be lighter
tomorrow, but with RH values in the upper 20s to the mid 30s
across the Catskills and portions of NE PA, especially Pike
County, and dry fuels, the risk for quickly spreading brush
fires remains elevated. Highs tomorrow will mainly be in the
upper 40s to the mid 50s.
As the upper ridge breaks down some tomorrow night, a weakening
cold front will be approaching from the west with a chance of
mostly rain showers, mainly after midnight and across CNY. With
plenty of dry air in place, the shower activity will struggle as
the front pushes eastward, so rainfall amounts do look to be
generally less than a tenth of an inch. Lows tomorrow night
range from the mid 30s to the low 40s.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
210 PM Update:
The upper level shortwave and associated surface cold front will
finish working its way through the area on Monday and will be
replaced by high pressure building in. As a result, some
lingering rain showers will be possible in Central NY Monday
morning into the early afternoon, but otherwise a drying trend
will be present along with gradual clearing skies. A northwest
flow may keep some clouds around for parts of Central NY, but
elsewhere, mostly sunny skies are expected by the afternoon.
Temperatures are expected to be above normal with highs in the
lower 50s to near 60.
High pressure will briefly be in control for Monday night
through at least Tuesday morning, before a relatively weak area
of low pressure centered across the western Great Lakes will
allow for a series of fronts to approach the area. Dry
conditions are expected to remain for Monday night and likely
through all of Tuesday as well. Temperatures on Tuesday will be
closer to normal (although still a few degrees above normal)
with highs likely in the upper 40s to mid 50s.
Then by Tuesday night, a few rain showers will be possible
(mainly across Central NY). This system will be lacking moisture
with drier air in place, so overall coverage of these showers
will not be high.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
210 PM Update:
The weaker low pressure system across the western Great Lakes
will dissipate as a stronger low pressure system develops across
the Ohio Valley and central Great Lakes region on Wednesday. A
few isolated showers cannot be ruled out during the afternoon on
Wednesday, but chances are much greater that Wednesday remains
precipitation-free with partly sunny skies. Temperatures
Wednesday will be above normal again with highs in the lower 50s
to lower 60s.
The weather then becomes quite unsettled beginning Wednesday
night and likely persisting through the remainder of the long
term period as the slow moving and moisture laden system slowly
pivots through the region. This system will initially bring
periods of rain before colder air filters in behind the system
with wrap-around/lake enhanced rain and snow showers. At some
point during the progression of this complex system, there will
likely be a dry slot that will move in, although when exactly
that will occur is a bit uncertain this far out. PoPs were
reduced slightly from the NBM for this reason, especially
farther to the south towards Northeast PA.
Temperature-wise, near-normal temperatures (mid 40s to near 50) are
anticipated for Thursday with the rainfall, but colder air will
filter in behind the system for Friday and Saturday with highs
only topping out in the upper 30s to mid 40s.
&&
.AVIATION /03Z SUNDAY THROUGH THURSDAY/...
VFR through the evening. However, another MVFR cloud deck likely
to move into KELM,KBGM and KITH overnight. The cloud deck may
reach KAVP as well but shouldn`t reach KSYR or KRME. Clouds
break up after sunrise then VFR with winds under 10 knots.
Outlook...
Sunday night and Monday...Restrictions possible with showers.
Low to moderate confidence.
Tuesday into early Wednesday...VFR. Moderate confidence.
Wednesday afternoon through Thursday... restrictions possible
with a chance of rain showers.
&&
.FIRE WEATHER...
A special weather statement will be issued for enhanced risk of
wildfire spread over the Catskills on Sunday; this is collaborated
with WFO Albany and NY DEC. Minimum RH values look to fall
between 30-45% in the late afternoon over portions of Delaware
and Sullivan counties. Winds will be much lower than Saturday;
out of the west-northwest at 3-8 mph, with a few gusts up to 12
mph possible.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...None.
NY...None.
&&
$$
SYNOPSIS...DK
NEAR TERM...DK/MJM
SHORT TERM...BJG
LONG TERM...BJG
AVIATION...MWG
FIRE WEATHER...
Area Forecast Discussion
National Weather Service Goodland KS
649 PM MST Sat Nov 16 2024
.KEY MESSAGES...
- Areas with snow cover (far western Kit Carson/Cheyenne
counties, CO) will continue to see below average temperatures
the next couple days.
- Slight chance (15-20%) of a period of freezing drizzle across
central and western Cheyenne county Colorado Sunday evening.
- Moderate to heavy rain (~1") possible east of Highway 83
during the day on Monday.
- Near 0F wind chills possible Wednesday morning in the western
CWA.
&&
.UPDATE...
Issued at 621 PM MST Sat Nov 16 2024
For tonight I lowered forecast low temperature down a few more
degrees in wake of the cold front as dew points in the low to
mid 20s work into the area. Winds are forecast to remain light
and variable along with clear skies should result in the
potential for optimal radiational cooling.
The other change that was made was to introduce freezing drizzle
into the forecast across central and western portions of
Cheyenne county from 5p-11p MT Sunday (00Z-06Z). The warm nose
that I was observing on the NAM last night across the same area
remains and now the RAP is also suggesting the same along with a
similar forecast sounding as well. Both RAP and NAM show a
850-700mb layer boundary draped across the area along with
modest omega along the boundary as well which indicates to me
lift. The reason why I`m thinking more freezing drizzle than
freezing rain at this time is due to the lack of mid level
moisture, albeit it will be increasing during this time I don`t
believe it will be enough to fully become freezing rain/rain. At
this time, no ice accumulation is anticipated but for those
traveling during this time be prepared for slick spots
especially on bridges and overpasses. My confidence for freezing
drizzle occurring is currently around 15-20% as it isn`t the
most slam dunk set up as I would like to see a bit more moisture
just above the lower level saturations as it may be to dry for
anything to develop but is enough to warrant putting into the
forecast.
&&
.SHORT TERM /THROUGH MONDAY NIGHT/...
Issued at 149 PM MST Sat Nov 16 2024
Across the region this afternoon, skies are sunny as a front has
pushed through the region earlier today and is currently sitting
just east and south of the cwa. Temperatures as of 100 PM MST are
ranging in the 60s in NE/KS, and a 50s/60s mix in Colorado except in
western Kit Carson/Cheyenne counties where area snowpack is only
allowing 40s. Winds over the area are westerly close to the front in
the east and northwest-north behind it with so decent gusts at times
in the 20-30 mph range.
The main weather concerns in the short term are going to be focused
on the rainfall chances over the area Sunday night into Monday night.
Currently for the remainder of the afternoon hours, the CWA will
continue to see great conditions persist into sunset. From there
some increased cloud cover expected from the south along the front
that has stalled E/S of the CWA. This will affect overnight
temperatures. Going into Sunday, surface ridge over the area during
the day ahead of an approaching upper level trough/closed low, will
allow for another nice and cool day for the area.
For Sunday night into Monday night, the attention turns to the
closed 500mb low that guidance forms in the Desert SW and lifts
E/NE. NAM/GFS/ECMWF guidance are different as to the path the low
will take as it lifts northeast into the central Plains by 12z
Monday. The ECMWF is the outlier puling the system a bit further
west, but will continue to have better confidence with the GFS/NAM
which lifts the system into central Oklahoma and eventually central
Kansas before lifting out Monday night. The surface low associated
with the system will lift northward in tandem along the remnants of
the aforementioned front. This is going to allow the best
lift/dynamics/QPF focused mainly in the eastern CWA. The current
track will put the best/highest QPF in the east which is consistent
with the previous forecast shift, with numbers changing ever so
slightly. There will be wrap-around moisture the will kick some
shower activity westward, but the northerly flow working into the
western area will allow for a sharp cutoff in the highest pops(20-
50% west of Highway 25 and 50-90% east of Highway 25). QPF will
range at this time from a few hundredths to a few tenths of an inch
along/west of Highway 27, increasing east to 0.30-0.50" up to
Highway 83. East of there, locales (could) receive up to an inch
based on current track. Note...any further shift east or west will
change the expected totals. As the system exits going into Monday
night, NW flow gusting to 20-30 mph could bring about cold wind
chill readings area-wide.
For temps, highs on Sunday will mainly range in the 50s, except in
the 40s for locales in western portions of Kit Carson and Cheyenne
counties in Colorado still impacted by area snowpack. Going into
Monday, with the expected precipitation and cloud cover, a mix of
40s and 50s is expected.
Overnight lows tonight will range widely in the 20s and 30s, warmest
in the E/SE where increased cloud cover will slow radiational
cooling effects. Sunday and Monday nights will be similar but the
area of 30s will be pushed further west due to increased/persistent
cloud cover.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
Issued at 1148 AM MST Sat Nov 16 2024
The latest runs of the GFS and ECMWF are continuing to show the main
weather concerns in the extended focused on the Tuesday through
Wednesday morning timeframe. Both models continue to show a quick
moving shortwave swinging through the region with a surface ridge
moving southeast out of the central Rockies in tandem. The two
models continue to differ on placement/timing of this system moving
through, but the overall trend is for a 15-20% chance for light snow
showers to fall mainly across northeast Colorado. Current light QPF
could bring about a few tenths of an inch to the Flagler, Colorado
area during this time. North/south of this little to no accumulation
is expected at this time. There will be a persistent strong
northwest gradient ahead of the ridge from the west. While initially
over areas from Highway 27 and west, it will overspread the rest of
the CWA into Wednesday. Gusts could approach the 25-35 mph range
before tapering off.
As the threat for light snow showers decreases and the wind
increases, CAA(Cold Air Advection) increases late in the day into
the evening/overnight hours. This will be aided by clearing skies
aiding in radiational cooling of the area, bringing below normal
overnight lows. These numbers combined with the brisk winds will
create low wind chill readings, especially for areas along/west of
Highway 27 into Colorado.
As winds subside during the morning hours Wednesday, both models
bring broad 500mb ridging into the Plains from Wednesday night
through the end of the week. This will result in dry conditions with
above normal temperatures area-wide.
For temps, looking for daytime highs on Tuesday and Wednesday to
continue to range below normal mainly in the 40s for most locales.
Areas in Colorado still seeing impacts of snowpack may only see the
mid and upper 30s. This may trend a bit warmer as guidance catches
up with area snowmelt over this weekend`s warmth into next Monday.
For Thursday into next Saturday, near to above normal conditions
with mainly mid and upper 50s expected. There could be a few spots
around 60F.
Overnight lows will be coldest on Tuesday night w/ teens and 20s
expected. Thereafter, mainly mid and upper 20s to around 30F. With
wind accompanying the cold overnight lows, especially Tuesday night,
wind chill readings will range in the single number to mid teens
above zero Tuesday night into Wednesday morning. Thereafter, teens
Wednesday night will give way to 20s for Thursday and Friday
nights.
&&
.AVIATION /00Z TAFS THROUGH 00Z MONDAY/...
Issued at 346 PM MST Sat Nov 16 2024
VFR conditions remain forecasted across the area for this TAF
period. RAP does show a few hours of LLWS affecting each
terminal from a north to south moving progressive jet that is
forecasted to be through the area around 06-07Z. Winds will
then slowly back to the west and then finally to mainly the
south around late morning Sunday.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...None.
CO...None.
NE...None.
&&
$$
UPDATE...Trigg
SHORT TERM...JN
LONG TERM...JN
AVIATION...Trigg
Area Forecast Discussion...Updated
National Weather Service Lincoln IL
858 PM CST Sat Nov 16 2024
.KEY MESSAGES...
- Rain and gusty winds will overspread the region on Monday. The
rainfall forecast is generally between 0.25" - 1", and we are
anticipating 30-40 mph wind gusts by Monday evening.
- A powerhouse autumn storm system will push into the region
Wednesday and Thursday, bringing gusty winds (30-40 mph) and
showery precipitation (40-60% chance).
- Much colder temperatures arrive Thursday - Saturday with sub-
freezing overnight lows likely (> 60% chance) at some point
during this stretch.
&&
.UPDATE...
Issued at 858 PM CST Sat Nov 16 2024
Moist warm advection has been producing mid level cloud cover near
the Mississippi Valley this evening ahead of a frontal zone
stretching from MN to west TX. Although some weak echoes have been
detected on radar, surface observations indicate most or all of
this isn`t reaching the ground, especially farther east into west
central IL. Nevertheless, this band of echoes looks to keep
shifting eastward overnight, and should result in at least a
potential for sprinkles reaching as far east as I-55 as additional
moisture continues to advect into the area. Cloud cover has been
more sparse than expected in eastern IL so have decreased sky
cover there. Breezy south winds around 10 mph will continue across
the area tonight. Otherwise, lows still appear to be on track for
mid 40s tonight, with the lowest readings likely east of I-57
where clearer skies and lighter winds are more prevalent.
37
&&
.DISCUSSION...
Issued at 149 PM CST Sat Nov 16 2024
Afternoon water vapor imagery currently depicts two areas of
interest: (1) a short-wave trough moving across the Black Hills,
and (2) a deep trough digging into Baja California. While both
waves will be responsible for bringing sensible weather to
central Illinois, the latter is expected to be more impactful in
the week ahead.
By late tonight, a pre-frontal surface trough and trailing cold
front associated with the northern track shortwave will move
across the mid-Mississippi Valley. A plume of low-level moisture
and weak isentropic ascent ahead of this feature could result in
a few sprinkles Sunday morning west of I-55. Some guidance (e.g.
RAP & NAM) supports sprinkles through much of the day on Sunday as
the cold front pushes into central Illinois and stalls out.
Whatever precip we`re able to squeeze out Sunday, it`s going to
have to be from low- level processes, with the upper forcing
sailing well out of our area.
Attention then quickly turns to Monday as the southern stream
trough lifts across the Southern Rockies and pivots into the
Plains. Strong temperature advection associated with this
disturbance will increase baroclinic instability and result in
rapid cyclogenesis throughout Monday. While the main impact from
this system, at least for central Illinois, appears to be gusty
winds, there will be widespread rainfall as well. A robust influx
of sub-tropical moisture surging northward from the western Gulf
will help bring 1.5" PWATs into central Illinois, which exceeds
the 99th percentile of available moisture for mid-November
climatology. With strong synoptic lift (jet dynamics) juxtaposed
to a moisture-laden airmass, we should be able to take another
healthy bite out of our drought. With hi-res guidance not out far
enough to resolve this frontal system, we are relying on NBM and
LREF guidance for our rainfall goalposts (10th-90th percentile),
which look to fall between 0.25"-1". More impactful, hmoistrureowever,
will the be the gusty winds. With the deepening surface low
positioned to our northwest, synoptic wind gusts will be in the
30-40 mph range. Worth monitoring, though, will be the potential
for convective showers to help transfer momentum downward from a
50 kt, 925-mb jet core. If this were to happen, we could be
dealing with a few 40-50 mph gusts, particularly Monday night.
After the Monday system goes through its occlusion and phases
together with another trough digging out of the Pacific
Northwest, the Midwest will once again be facing a powerhouse
late-autumn storm system. While all signs point to a deepening
upper- level low bottoming-out somewhere over the Great Lakes,
just how deep and exactly where it develops remains an enigma.
Honing-in on deterministic global guidance such as the GFS and
ECMWF has largely been useless, with the storm track frustratingly
bouncing back-and-forth somewhere between Indy and Cleveland.
This, of course, can dramatically change our wind and snow
forecast. But, if we key-in on the blended (NBM) and ensemble
(LREF) guidance, we can take a more probabilistic approach which
leads us to a few early conclusions: (1) gusty winds in the 30-40
mph realm; (2) a low probability (< 15% chance) for a 2" snowfall;
and (3) a high probability (> 50%) chance for sub-freezing
overnight temperatures sometime between Wednesday night and Friday
night. As always, we will need some more time to monitor snow
trends. Even taking an ensemble approach, the mean often
camouflages the variance.
MJA
&&
.AVIATION... (For the 00z TAFs through 00z Sunday Evening)
Issued at 543 PM CST Sat Nov 16 2024
Low level moisture ahead of an approaching frontal zone will bring
decreasing ceilings late tonight into early Sunday afternoon, as
well as a chance for scattered sprinkles. Numerical and
statistical guidance points to cigs reaching MVFR by around 14Z at
KPIA and KBMI to as late as 20Z at KCMI, with little chance for
IFR cigs. Although scattered sprinkles are possible, there is
little chance for any MVFR vsby to develop. Winds SSE around 10
kts overnight, shifting to SSW by around 14Z.
37
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
Area Forecast Discussion
National Weather Service Newport/Morehead City NC
1006 PM EST Sat Nov 16 2024
.SYNOPSIS...
A ridge of high pressure will build into the Carolinas
tonight and on Sunday gradually moving offshore early next week.
Another front will approach the area mid next week.
&&
.NEAR TERM /THROUGH SUNDAY/...
As of 1005 PM Sat...Temperatures continue to fall into the low
40s with almost all areas fully decoupled, including along the
Outer Banks where MinTs needed to be lowered another few
degrees. Some very spotty fog has been reported across the
coastal plain, but it has been very transient and highly
variable in density. This trend will continue through the night,
becoming more predominant around dawn.
Prev disc...As we get into tonight expect high pressure ridge
to become centered over the Carolinas this evening allowing
winds to decouple across the Coastal Plain, but allow for a
slight breeze closer to the coast where the pressure gradient is
pinched. In addition to this, clear skies will remain overhead
setting up good conditions for strong radiational cooling this
evening. As the evening wears on dry air over the area will help
to tank dewpoints into the mid to upper 30s allowing lows to
get into the mid to upper 30s inland and low 40s to low 50s
along the coast and OBX. This will bring two forecast challenges
for tonight. The first will be the potential for patchy ground
fog across the Coastal Plain. While the HRRR remains rather
aggressive with fog chances, the rest of the Hi-Res suite is
unimpressive and HREF probs for visibilities remain at about
10-20% across our SW`rn zones. Even with these potential lower
chances, given pattern recognition it appears that there is at
least a low end threat for some patchy ground fog so have added
that into the forecast for tonight.
In addition to this, with good radiational cooling expected,
lows look to get down into the mid to upper 30s inland and with
calm winds frost is possible. HREF probs for temps below 38 F
and light winds are around 20-40% for the Coastal Plain which is
supportive for at least a patchy frost threat inland especially
across sheltered locations and as a result have issued a frost
advisory for Martin, Pitt, Greene, Lenoir, Duplin, Washington,
and Beaufort Counties where the highest chance`s for frost are
set to occur. Further east and closer to the coast a light N`rly
breeze should help hinder any potential frost threat and keep
temps slightly elevated tonight.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH 6 PM SUNDAY/...
As of 4 PM Sat...High pressure ridging remains overhead on
Sunday promoting fair weather to end our weekend. High temps are
about the same on Sunday getting into the low to mid 60s across
ENC. Light and variable winds in the morning will gradually
become S`rly by Sun evening as high pressure ridge begins to
push offshore.
Coastal flood concerns will continue into Sunday as well, with the
greatest risk for Hatteras and Ocracoke Islands through the next few
high tide cycles with potential for additional ocean overwash. See
CF section below for additional details.
&&
.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
As of 0300 Saturday...High pressure in place through early next
week bringing seasonable temperatures and dry weather to the
region ahead of the next front Wed-Thurs.
Monday...Ridge of high pressure continues to gradually push
offshore early next week with dry weather expected. Temps will
be near climo through this period with highs in the 65-70 degree
range and lows in the lower 40s for most.
Tuesday through Wednesday...The ridge of high pres amplifies and
sfc high traverses south of the region during this period, with
temps warming back to above climo, into the 70s and lows in the
upper 40s to mid 50s. Conditions still appear to remain mostly
dry, though an approaching cold front may bring a small shower
threat. However, the GOM will be cut off from this quick moving
low amplitude system, and will therefore not be much moisture to
work with. Have silent 20 pops in the grids over land for now
with higher PoPs up to Chc along the immediate coast.
Late week...Aforementioned front will have passed through, and
gusty wsw winds in it`s wake are expected as tightened gradient
will be in place. Weather appears to remain on the dry side with
low RH`s expected and seasonable highs in the 60s.
&&
.AVIATION /03Z SUNDAY THROUGH THURSDAY/...
SHORT TERM /through Sunday Morning/...
As of 730 PM Sat...VFR conditions prevail across all terminals
this evening under high pressure, clear skies, and calm winds.
Main concern tonight, like yesterday, is shallow fog. 18Z HREF
hasn`t deviated much from the previous forecast, favoring at
least MVFR visibilities mainly south of ISO-EWN. Saturated
inversion layer will be extremely shallow and any fog should be
transient. Given OAJ`s historical ease in fogging over in
radiational cooling regimes, added a TEMPO group for this
terminal but left other TAFs with no visibility restrictions.
VFR conditions return tomorrow with light north winds gradually
veering southerly as the surface high shifts offshore.
LONG TERM /Sunday afternoon through Thursday/...
As of 0300 Saturday...Predominantly VFR flight cats through the
period outside of early morning fog potential through early
next week Next frontal system to impact the area middle of next
week.
&&
.MARINE...
SHORT TERM /through Sunday/...
As of 4 PM Sat...High pressure continues to build in from the
north and west allowing the pressure gradient to relax across
the region. This has allowed for SCA`s to end across all inland
sounds and rivers today with SCA`s left across the Coastal
Waters tonight. Ongoing 10-20 kt winds with 25+ kt gusts along
the coastal waters should ease by Sun morning down to 10-15 kts
with gusts around 20 kts. With high pressure centered overhead
by Sun evening winds across all waters will ease even further
down to 5-10 kts. With winds easing, seas along our coastal
waters will also gradually ease through the weekend. Latest obs
show widespread 6-9 ft seas across our coastal waters this
afternoon north of Ocracoke with with 4 to 6 ft seas noted south
of Ocracoke. Tonight, seas south of Ocracoke will lower closer
to 3-5 ft which will end the SCA`s across our southern waters.
Seas lower further on Sunday as winds ease to 3-5 ft everywhere
allowing all SCA`s to end across our coastal waters on Sunday.
LONG TERM /Sunday through Thursday/...
As of 0300 Saturday...Boating conditions continue to improve
Sun with seas falling below 6ft across all area waters Sun
night. Tuesday will be the best boating day with ridge of high
pres nearby with light winds less than 10 kt and seas of 2-4 ft.
Winds become more S-SWerly 10-15 Tues afternoon, 15-20 late Wed
ahead of the next front which will likely bring strong SCA
conditions at a minimum.
&&
.TIDES/COASTAL FLOODING...
As of 4 PM Sat...Coastal flood warnings and high surf
advisories have since ended across the area with Coastal Flood
advisories in effect across the OBX and Crystal Coast through
Sunday mornings High Tide Cycle. NC-12 between the Ferry
terminal and the Pony Pens on Ocracoke has just recently opened,
but NCDOT-12 has noted it will once again close at 6PM due to
potential for some additional ocean overwash and coastal
flooding during the coming high tides. While winds and seas will
be on the downtrend, elevated water levels will persist through
at least the next two High Tide Cycles and inundation values up
to two feet will remain possible along the OBX, Crystal Coast
and adjacent tributaries.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...Frost Advisory until 8 AM EST Sunday for NCZ029-044-045-079-
080-090-091.
Coastal Flood Advisory until 11 AM EST Sunday for NCZ195-196-
199-203>205.
MARINE...Small Craft Advisory until 10 AM EST Sunday for AMZ150.
Small Craft Advisory until 1 PM EST Sunday for AMZ152-154.
&&
$$
SYNOPSIS...MHX
NEAR TERM...MS/RCF
SHORT TERM...RCF
LONG TERM...SK/CEB
AVIATION...MS/CEB
MARINE...CEB/RCF
TIDES/COASTAL FLOODING...MHX
Area Forecast Discussion
National Weather Service Phoenix AZ
437 PM MST Sat Nov 16 2024
.UPDATE...Updated 00z Aviation Discussion.
&&
.SYNOPSIS...
A mostly dry weather system will traverse the region this weekend,
bringing occasional breezy conditions and much cooler temperatures.
For South Central Arizona, precipitation chances remain near zero
except over the high terrain of Southern Gila County on Sunday.
Today has shaped up to be the coolest day of the next 7, with lower
desert highs only reaching the lower to middle 60s. Temperatures
will moderate Sunday through early next week in the upper 60s to
lower 70s before a more distinct warming trend commences during the
latter half of the upcoming work week.
&&
.DISCUSSION...
Current mid-level wv imagery and 500 mb RAP analysis depicts an
elongated, positively-tilted upper level trough with its axis
aligned from just off the Baja California coast all the way up
through the Intermountain West and Northern Plains. Despite the
strong dynamics with this trough, evidenced by a 140+ kt jet streak
at the 250 mb level along its eastern edge, its orientation combined
with limited moisture over the forecast area will make for near zero
precipitation chances today. However, the possibility for some
periods with isolated virga showers cannot be ruled out through
tonight over Southwest/South-Central AZ. Models remain in excellent
agreement that over the next 24-36 hrs the upper level trough will
begin to detach from the northern stream, becoming more
characteristic of a closed low, with the strongest negative height
anomalies centered somewhere over the Gulf of California/Northern
Sonora before ejecting to the northeast Sunday night into Monday.
With the closed low centered south of the region, strong southerly
flow along its eastern flank will begin to draw better quality
moisture into the Desert Southwest, though mainly well to the east
of the forecast area. As a result, the best chances for
precipitation will remain over the southeastern corner of AZ and
along prominent terrain features of far eastern AZ on Sunday. Some
wrap around showers may make their way into Southern Gila County
tomorrow, resulting in very light accumulations, if any.
Temperatures are forecast to remain in a below normal category
through Tuesday, with today being the coolest, as broad troughing
remains present over the Western US through early next week.
Temperatures so far this afternoon are around 5-10 deg F below what
they were at this time yesterday, and they will peak mostly in the
lower to middle 60s across the lower deserts today. Ensembles
continue to advertise a shortwave trough diving southeastward into
the Great Basin Region and passing to the north Monday night into
Tuesday, reinforcing the negative height anomalies aloft, and
helping to keep highs in the upper 60s to lower 70s each day. Aside
from maintaining the cooler temperatures, the only other sensible
weather impact from this shortwave trough will likely be breezy
conditions along the typically wind-prone locations such as the
Lower Colorado River Valley.
By Wednesday, a warming trend is expected to begin, as high pressure
builds over the Western US. Ensemble guidance shows an upper level
pattern setting up where persistent, deep troughing develops off the
West Coast and over the Eastern US, with ridging over much of the
Western US. Upstream troughing off the West Coast seems to be the
main determining factor as to how much heights aloft will increase
over the Desert Southwest late next week, and uncertainties in the
strength and location of upstream troughing are quite apparent in
the WPC cluster analysis. The latest probabilistic NBM output
reflects the uncertainty in how amplified ridging over the Western
US will become late next week, with IQRs for the forecast high
temperatures increasing to a modest 5-8 degrees Wednesday onward.
For now, the inherited NBM deterministic forecast shows widespread
highs in the upper 70s to around 80 degrees across the lower deserts
late next week into early next weekend.
&&
.AVIATION...Updated at 2345Z.
South Central Arizona including KPHX, KIWA, KSDL, and KDVT:
Extended periods of variable wind directions will be the greatest
weather issue through Sunday afternoon as 7K-8K ft AGL cigs
develop during the daytime hours. Confidence is very low with
respect to exact timing of wind shifts and prevailing wind
directions through much of the period. Directions will generally
favor a west component this evening into the overnight, with some
indication of a E/NE component Sunday morning. However, there may
be prolonged periods of variability across the Phoenix airspace,
albeit with speeds under 10kt.
Southeast California/Southwest Arizona including KIPL and KBLH:
No major weather issues will exist through Sunday afternoon under a
few passing midlevel cloud decks. Northerly winds will generally be
preferred through the period with some tendency for KIPL directions
to back to a west component on occasion. Some increased gustiness
will be possible Sunday afternoon.
&&
.FIRE WEATHER...
An overall dry weather system will push through the region this
weekend bringing periodic breeziness, higher humidities and below
normal temperatures. Any precipitation chances are expected to be
limited to the eastern Arizona high terrain on Sunday, but CWR will
still be less than 10%. MinRHs today will mostly range between 20-
30% across the lower deserts before gradually lowering into the
teens by Monday as high pressure begins to move back into the
region. Expect temperatures to gradually warm back to normal by
around Wednesday and even above normal late next week under even
drier conditions.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...None.
CA...None.
&&
$$
DISCUSSION...Whittock/Kuhlman
AVIATION...Young/18
FIRE WEATHER...Kuhlman
Area Forecast Discussion
National Weather Service Riverton WY
354 PM MST Sat Nov 16 2024
.KEY MESSAGES...
- Snow showers this afternoon should dissipate for most areas
after sunset.
- Gusty to strong wind will develop late tonight and Sunday in
the favored southwesterly flow areas.
- The next Pacific trough and cold front will bring the next
round of snow from late Sunday night through Monday.
&&
.DISCUSSION...
Issued at 118 PM MST Sat Nov 16 2024
he main things that is occurring today is, to quote the most well
known song from the classic movie "The Sound of Music", one of my
favorite things. However, this is also combined with a heavy dose of
my Gen X / New Englander sarcasm. This thing is convective snow
bands, the things that make my pull out what is remaining of my
thinning hair.
The main concerns here is near South Pass, where as I write this
around 12:30 pm, one appears to be forming with the favorable
northwest flow. The HRRR continues to depict this well. However, it
has backed off snowfall amounts. There will likely be a couple
of inches of snow over the Pass, but the heaviest amounts would
stay over the higher elevations. It could be a rough couple of
hours trying to go through there though. This should dissipate
around sunset as we lose the instability of the day. Another
area of concern may be near Highway 120 and west where some
northeast upslope flow may enhance snow showers somewhat. Again,
most of these should end shortly after sunset.
There is no rest for the weary though, as the next Pacific trough
and cold front will be on its heels. The first impact will be strong
wind, which will arrive later tonight into tomorrow in the favored
southwest flow areas. This is mainly South Pass and from Muddy Gap
through Casper. As for high wind, it is questionable. There will be
a 100 knot jet streak moving over the area late tonight. However,
most guidance is showing 700 millibar knot winds remaining under 50
knots, with the core of these stronger winds remaining over Carbon
County. There is a greater than 3 out of 5 chance of wind gusts past
40 mph here though. So for now, we will hold off on any highlights.
The other concern is around and west of Cody. Again, the chance of
wind gusts past 40 mph is fairly high, generally greater than a 2
out of 3 chance. The chance of high winds, (gusts past 50 knots),
is less than 1 out of 10 in town and even in the favored areas to
the west, it is only 1 out of 10. So again, no wind highlights would
be needed. The main time of concern here would be late tonight, with
less of a chance through the day on Sunday.
The main concern then shifts to snow. Moist westerly flow will keep
snow showers going in the northwestern mountains through Sunday,
but amounts will remain light. The steadier snow looks to break out
after midnight and continue through Monday before tapering off
Monday night as the trough axis moves to the east. Highlights will
likely be needed for this system. Right now, we would be leaning
toward advisories rather than warnings. Probabilistic guidance shows
greater than a 4 out of 5 chance of 6 inches or more in the Tetons
and southwest Yellowstone, with greater than a 50 percent chance in
portions of the Salt and Wyoming Range and western Bighorn Range. As
for warning level amounts, the most likely area is southwest
Yellowstone, with a 3 out of 5 chance of a foot or more. However,
impacts from this would be minimal since Yellowstone is mostly
closed right now, especially that portion of the park. In conjunction
with surrounding offices, we will let later shifts make the
decision. Snow showers will be possible in the lower elevations
East of the Divide as well. However, like today, this would be
showery or banded snow that is impossible to pinpoint this far
out.
Mainly lighter showers continue into Tuesday. Following that,
ridging will likely build northward and bring warmer and dry weather
for most of the area. The question here is whether or not the ridge
will be flatter and allow a couple of waves to brush by to the
north, bringing some lighter precipitation to the northern mountains.
Guidance remains in poor agreement with the main deterministic
models, the GFS and European, flip flopping with their solutions.
For now, given the uncertainty, we have made few change to
continuity.
&&
.AVIATION /00Z TAFS THROUGH 00Z MONDAY/...
Issued at 348 PM MST Sat Nov 16 2024
Snow in the region has become more limited and banded, and those
prone areas remain away for local airport, so not expecting any
more cig or vis limits from snow through the next 24 hours. Most
aerodromes have generally cleared out, but mountainous areas
will likely remain obscured through the night. Skies will
remain mostly clear on Sunday, with only high clouds moving into
western WY in the afternoon. Gusty winds return to KCOD/KCPR,
with gusts 30 to 40kts in the afternoon. Some gusty winds could
stretch into KRKS and KLND as well, but probabilities are much
lower in these locations at this time.
&&
.RIW WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
DISCUSSION...Hattings
AVIATION...Straub