Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 10/20/23
AREA FORECAST DISCUSSION
National Weather Service Albany NY
1040 PM EDT Thu Oct 19 2023
.SYNOPSIS...
Clouds will be thickening and lowering overnight, as a
storm system starts approaching the region. As a frontal boundary
approaches from the west and a coastal storm forms, some rain will
begin during the day on Friday and it will become steady for Friday
night into Saturday. Some lingering rain showers, along with cool
and breezy conditions, will continue into Sunday before drier
weather returns for next week.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
As of 1039 PM EDT...Mid and high clouds increase overnight
ahead of warm front/thermal trough with a strong storm system
over the Midwest. The lead edge of warm advection with the
trough will bring some light showers in from the south and west
towards daybreak. Some increase of the clouds were adjusted in
the forecast based on the IR satellite picture. We also adjusted
temps/dew points based on the hourly observations. We backed
PoPs off slightly based on the latest 3-km HRRR after sunrise.
Lows in the 40s to lower/mid 50s will be common.
PREV DISCUSSION [0339 EDT]...Some breaks in the cloud cover
finally occurred for this afternoon, with partial sunshine for
much of the area. However, clouds will be returning for this
evening and into tonight. Some high clouds can already be see
upstream of the area on satellite imagery to the south and west
and these clouds will gradually be spreading into the area for
tonight. The low- level flow will be southerly for tonight,
which will return return some low level moisture to the region
as well. With the best forcing still remaining west of the
region, it should stay dry through the overnight hours for most
locations.
Overnight lows will mainly be in the upper 40s to low 50s across
the region.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/...
The upper level shortwave trough will be continuing to head
eastward towards the area for Friday. It will begin to take on a
negative tilt as it gets closer to the region. Meanwhile, a strong
jet streak at 250 hpa (perhaps aided by a weak surface as well)
will help initiate some showers on Friday morning across NJ/NYC
area/Lower Hudson Valley and these will be lifting north-
northeast across the Hudson Valley/Taconics and into western New
England for Friday. This rain could also impact parts of the
Capital Region and Lake George Saratoga Region, although the
exact western extent is still uncertain. A steadier area of
rain may form from this activity as it lifts northward. Some
embedded moderate bursts can`t be ruled out within this
rainfall, especially for areas where the terrain may enhance the
rainfall as well. With the southerly flow, temps will still be
mild, despite the rain and clouds, with highs in the upper 50s
to mid 60s.
As the upper level trough gets closer, a line of showers will be
approaching along the storm`s cold/occluded front from the west
for Friday night. Meanwhile, a surface low will begin forming
off the mid Atlantic coast and this will be rapidly deepening
as it lifts northeast. The combination of these two features
will allow for a large area of stratiform rain to develop across
the area for Friday night into Saturday. Although the best
moisture surge will likely remain east of the region, persistent
steady rain looks to occur for the region for all of Friday
night and into most of Saturday. There are still some
differences in the models regarding the exact timing, track and
QPF, so have generally stayed close to the NBM blend and WPC
precip forecast through this time period. At this point, most
areas in New York will see about 0.50" to 1.50" of rain between
Fri and Sat. Western New England may see slightly higher (about
1 to 2 inches of rain with localized totals over 2" at the
highest peaks of the southern Greens). This rainfall may lead to
some river rises and ponding in urban or low lying areas, but
the rainfall rates and total QPF should be low enough to avoid
any bigger flood issues. Temps will remain fairly steady in the
50s for Fri night into Saturday thanks to the clouds and rain.
West to northwest winds will start to pick up for late Saturday
into Saturday night, although the strongest gusts will be behind
the storm for Sunday. Some lingering light rain may continue
into Saturday night, although this will ultimately depend on the
exact speed of this system.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
Depending on the exact speed of this system, some lingering
deformation light rain will continue into Sunday as the large
upper level trough slowly moves across the area. The best
chance of additional light rain on Sunday will remain over far
northern and eastern areas. Temps will remain cool in the 40s to
low 50s on Sunday. In addition, the breezy conditions (gusts up
to 35 mph) will make it feel even colder. A few lingering rain
or snow showers will be possible over the Adirondacks on Sunday
night, but this looks very spotty and no snow accumulation is
expected and precip should finally be winding down everywhere by
Monday morning.
Behind this system, dry weather will return for much of next
week. Temps will remain a little chilly to start the week, but
should moderate each day. Although the growing season will be
officially done by that point, some frost may occur across much
of the area for Monday night if it clears out enough and the
wind lightens up. The next chance of rain showers will be with
a northern stream system for mid to late week, but any precip
looks very light.
&&
.AVIATION /03Z FRIDAY THROUGH TUESDAY/...
VFR conditions continue this evening with mainly just cirrus clouds
overspreading the terminals. As we approach the pre-dawn hours,
mainly 09 - 12 UTC, ceilings will lower from south to north ahead of
approaching showers. Expecting POU and PSF to observe MVFR ceilings
first during this window with showers spreading from south to north
by 10 and 14 UTC. MVFR ceilings will lower at ALB a few hours later
as showers reach the area towards 12 and 16 UTC. GFL will be the
last to observe a flight category reduction and should remain VFR
until near or shortly after 18 UTC. The incoming rain will likely
support mainly VFR visibility but there could be some steadier
periods so include high end MVFR visibility during the rain at POU,
PSF and ALB.
The steadiest rain should exit from west to east in the afternoon
through about 18 UTC but light intermittent showers could linger
through the end of the TAF period. Show improving ceilings from west
to east mainly near and after 21 UTC.
Southeasterly winds remain elevated tonight sustained 5 to 10kts
with gusts up to 15kts, especially at PSF. Breezy southeasterly
winds continue after 12 UTC becoming sustained 8 to 15kts with gusts
up to 15 - 20 kts possible at ALB, PSF and POU through the end of
the TAF period.
Outlook...
Friday Night: High Operational Impact. Definite RA.
Saturday: High Operational Impact. Definite RA.
Saturday Night: High Operational Impact. Breezy. Likely SHRA.
Sunday: Moderate Operational Impact. Windy With Gusts To 31 kts. Chance of SHRA.
Sunday Night: Low Operational Impact. Breezy. NO SIG WX.
Monday: No Operational Impact. NO SIG WX.
Monday Night: No Operational Impact. NO SIG WX.
Tuesday: No Operational Impact. NO SIG WX.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
MA...None.
VT...None.
&&
$$
SYNOPSIS...Frugis/Wasula
NEAR TERM...Frugis/Wasula
SHORT TERM...Frugis
LONG TERM...Frugis
AVIATION...Speciale
Area Forecast Discussion
National Weather Service Boston/Norton MA
959 PM EDT Thu Oct 19 2023
.SYNOPSIS...
Increasing clouds overnight will yield to periods of showers on
Friday as rain chances increase from southwest to northeast. More
widespread rain expected overnight Friday through Saturday night as
a coastal low tracks northeast from the mid-Atlantic into the Gulf
of Maine. Winds increase behind the departing low, but overall, a
much drier day Sunday before dry and seasonably mild conditions set
up for next work week.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
10 PM update...
Only change to the forecast was to add some low pops to
Cape/Islands for the overnight period. Some of the CAMs are
indicating some light showers developing over the ocean and
moving NE within a plume of higher theta-e air which lifts
across SE New Eng. Otherwise, leading edge of larger area of
showers approach western MA/CT toward daybreak.
Previous discussion...
Dry conditions persist through much of the overnight, but
clouds will increase, and lower, as amplifying mid level trough
continues to pivot eastward toward southern New England and high
pressure that was in place for Thursday shifts out to sea. Hi-
res guidance is in agreement that the arrival of light rain will
be delayed until after 12Z, with the 12Z HRRR showing the
earliest onset of showers across southern Connecticut at 10Z.
Thus, while a mainly dry night, cannot rule out a few showers,
especially across our western zones, during the predawn hours.
Temperatures will be heavily influenced by increasing moisture
(dewpoints) and cloud cover. Given persistent southerly flow and
climbing PWATs, increasing some 0.25" over the next 12 or so hours,
and a lowering cloud deck, radiational cooling is off the table.
Overnight lows look to range from the upper 40s to low 50s region
wide, with patchy fog development possible.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/...
355 pm update...
Aforementioned mid level trough deepens over the course of the day
Friday, taking on a slight negative tilt by Friday evening as its
associated low pressure begins to drift eastward in to southern
Ontario and Quebec. Additionally, a second low develops off the mid
Atlantic coast Friday afternoon before strengthening and lifting
north towards southern New England Friday evening.
Prefrontal shower activity will begin Friday morning given deep,
persistent southerly flow advecting moisture and forcing provided by
a weak warm front lifting northward through the region. There is
still a question to how widespread and potent these showers will be
given a solid mid level layer of dry air, which could preclude
widespread moderate rain, but the general idea is that both coverage
and intensity will increase from southwest to northeast through the
day. With that said, much of eastern MA could remain dry as late as
18Z. The best forcing looks to hold off until after sunset Friday
with the cold front well to the west of southern New England and the
mid-Atlantic coastal low still in it`s early stages of development.
Friday Night...
While the standout coastal low wont impact the region until late
Saturday, there appears to be the potential for a series of
preceding coastal lows, the first presenting as a weak feature
southeast of Nantucket overnight Friday. Depending on the track of
this first low, more moderate widespread rain looks to develop
overnight; highest confidence for appreciable rainfall after 00Z
Saturday across the Cape and Islands. Global and hi-res models
differ on how strong this first low will be and how close it will
pass by southern New England given it will still be in it`s
developing stages. With a closer to the coast solution realizing
more expansive precipitation during the overnight hours while "Out
to sea" solutions, well, at least with the low southeast of the
benchmark, yield more showery precipitation overnight. Regardless of
the track of the overnight low, total QPF though 12Z Saturday
morning looks to amount to between 0.5-1.0".
Temperatures overnight will also be quite mild for this time of year
given continued moisture advection into southern New England. Lows
will range mainly in the 50s, with upper 50s possible along the
south coast.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
355 pm update...
12z suite of guidance continue to come in more agreement amongst
all the individual models with regard to the Saturday/Sunday
system. High confidence in a scenario where low pressure will
organize south of New England early Saturday morning and rapidly
strengthen and move northeast to a position offshore to our east
by Saturday evening, with surface pressure falling to around
980mb by that time. By early Sunday morning, that low should be
over the Canadian Maritimes.
So that means for Saturday morning, we will have a general
southeast flow across most of the area, and with precipitable
water values somewhere in the 1 to 1.25" range, the atmosphere
will be rather moist. The SE flow will also lend itself to some
upslope enhancement of precipitation across the Worcester Hills
and eastern slopes of the Berkshires. However as the low
consolidates and moves northeast -- likely moving across SE MA
and then to our east by late in the day, winds will turn
northwesterly and start to pull in a drier airmass and bringing
an end to the rain. We should end up seeing rain totals of .75
to 1.5 inches by that time. No flooding issues are expected. One
other item to note, models do show some weak instability aloft,
with Showalter Index values dropping down near 0 on Saturday.
This suggests an isolated embedded rumble of thunder is not out
of the question. As such, have included that possibility in the
forecast.
Unlike other developing low systems, this one won`t have any
strong winds on the north or east side, but rather it will be on
the south side as the low moves away. So as the winds turn
northwest, they will start to strengthen and become gusty. Those
gusty winds will last through Sunday. Model sounds via BUFKIT
show decent mixing up to 3000-4000ft (depending on the model)
developing on the backside of the low Saturday evening and
continuing through Sunday. That will be able to tap into
moderately strong winds several thousand feet above the surface.
Looking at the probabilitic guidance, we don`t see any strong
signal for wind gusts over 45 mph (which is about where we would
start to see more wind related issues). The probabilities of 45
mph gusts tops out at about 20%, and even then it`s across the
higher terrain of western and central MA and northwest CT. That
said, probabilities of 35-40 mph peak gusts are above 60% for
much of the region. Thus, high confidence in a breezy/gusty
Saturday night and Sunday, however these values are below wind
advisory thresholds. It is that time of year where Mother Nature
gives us wind to help take the leaves off the trees.
A period of dry weather is expected from Sunday through at least
mid week. Still a bit breezy on Monday, but as high pressure
builds in, those winds will weaken. Stuck with NBM blend for
much of that period.
&&
.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...
Overall moderate confidence in the forecast.
Easy part of the forecast is 00z through about 09z. VFR will be
the rule. Increasing mid/high level clouds. Could be some
isolated BR, but have removed any mention from the TAFs due to
low confidence. BAF and BED would be the two locations that
could see some late tonight.
After 10z, there could be a few showers coming up from the south
into CT, and perhaps approaching BDL and BAF after 12z. Still
quite a bit of uncertainty in this timing. In any case, shower
activity should develop by 15z (if it hasn`t already) across
western areas and slowly push eastward, and expected to be
getting into RI and eastern MA somewhere around 20z. Error bars
of a few hours on this timing, so the TAF represents the best
estimate but is likely to change in later updates.
Ceilings will be VFR to start, but as the -SHRA expands, we
should start to see MVFR conditions also develop.
Friday Night...conditions are expected to range from MVFR to IFR
area wide as widespread moderate rain will occur.
KBOS Terminal...Moderate confidence in TAF. South winds tonight
become SE tomorrow and then ESE by early evening. Timing of
precipitation in the afternoon is uncertain. Although not
included in the TAF at this point, there is the potential for
IFR conditions developing between 00-06Z Saturday.
KBDL Terminal...Moderate confidence in TAF. Uncertainty in
timing of precipitation in the morning, and how soon MVFR
conditions develop. May not actually be raining for periods of
time on Friday, but too hard to pinpoint those times, so have a
more general -SHRA for most of the day.
Outlook /Saturday through Tuesday/...
Saturday: Mainly MVFR, with areas IFR possible. Windy with
local gusts up to 30 kt. RA, isolated TSRA.
Saturday Night: MVFR/IFR conditions possible. Windy with gusts
up to 35 kt. Chance RA, slight chance SHRA.
Sunday: Mainly VFR, with areas MVFR possible. Strong winds with
local gusts up to 40 kt. Chance SHRA.
Sunday Night: Mainly VFR, with local MVFR possible. Strong
winds with local gusts up to 40 kt. Slight chance SHRA.
Monday: VFR. Breezy.
Monday Night through Tuesday: VFR.
&&
.MARINE...
Forecaster Confidence Levels:
Low - less than 30 percent.
Medium - 30 to 60 percent.
High - greater than 60 percent.
330 pm update...
High confidence.
Persistent southwesterly flow becomes more southeast during the day
on Friday, but generally less than 15 knots through the period.
Showers and isolated thunder possible, especially for the southern
waters, Friday, before rain chances increase across all of the
marine zones Friday night. Waves build ahead of approaching low
pressure such that SCA conditions develop around 12Z Saturday. Given
there is potential for Gale Conditions later in the weekend, elected
to hold off on issuing SCAs to evaluate the need for a Gale Watch
over the next few forecast cycles.
Outlook /Saturday through Tuesday/...
Saturday: Winds less than 25 kt. Local rough seas. Rain,
isolated thunderstorms.
Saturday Night: Strong winds with gusts up to 40 kt. Rough seas
up to 10 ft. Chance of rain, slight chance of rain showers.
Sunday: Strong winds with gusts up to 35 kt. Rough seas up to
10 ft. Slight chance of rain showers.
Sunday Night: Strong winds with gusts up to 35 kt. Areas of
rough seas. Slight chance of rain showers.
Monday: Low risk for Small Craft Advisory winds with gusts up
to 25 kt. Local rough seas.
Monday Night: Winds less than 25 kt. Areas of seas approaching
5 ft.
Tuesday: Winds less than 25 kt. Seas locally approaching 5 ft.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...None.
RI...None.
MARINE...None.
&&
$$
SYNOPSIS...KS/Nash
NEAR TERM...KJC/KS
SHORT TERM...KS
LONG TERM...Nash
AVIATION...KS/Nash
MARINE...KS/Nash
Area Forecast Discussion
National Weather Service Corpus Christi TX
640 PM CDT Thu Oct 19 2023
...New AVIATION...
.SHORT TERM...
(Tonight through Friday night)
Issued at 255 PM CDT Thu Oct 19 2023
The tail end of a mid-level trough is pushing through the area
today, but with very little moisture (PWAT values at or below 1"),
we are not really seeing any signs of it. There is a surface
boundary associated with this disturbance that is currently across
the Hill Country up toward North Texas. This boundary will
continue to drift down, and will likely make it into our northern
counties tonight but will have to fight a shallow marine layer to
make it closer to the coast. Some indications are that after
sunrise tomorrow it could sag a bit farther south and allow some
drier air to briefly spread over more of the region. Current
thinking is that while it could allow min temps to drop into the
50s in the Victoria Crossroads and northern Coastal Plains, but
most of the area will likely remain in the lower to middle 60s. In
areas south of the boundary we could also see fog develop
overnight as shallow surface moisture is pushing back in pretty
strongly today.
A low level (below 800mb) westerly flow and drier air will allow
temperatures to warm well above normal tomorrow with highs in the
lower to mid 90s for most of the region. By tomorrow afternoon
though, we`ll see the front retreat back to the north and onshore
flow redevelop once again ushering the shallow surface moisture
back in. Lows tomorrow night will be pretty similar to what we
will see tonight.
&&
.LONG TERM...
(Saturday through next Wednesday)
Issued at 255 PM CDT Thu Oct 19 2023
The forecast looks to remain on track from the previous forecast
cycle. We will continue to be influenced by an area of high pressure
in the Gulf through this weekend. Temperatures will be in the upper
80s to lower 90s through the period, though given the lower dew
points heat index values are not expected to exceed 100 degrees.
That area of high pressure will begin to track east early next week
in conjunction with, moisture associated from a tropical system
making landfall over western Mexico moving into the area.
Consequently there is a chance for showers and thunderstorms that
remains through most of the week (Pops 30-40%). PWAT values remain
just below to above 2.00 inches(up to 2.40 inches) through the week
which will allow any shower or thunderstorm that does get started,
to have plenty of moisture to work with. QPF for the period is
calling for about an tenth of an inch to about a quarter of an inch
possible mainly along the eastern portions of the Coastal Plains and
the Victoria Crossroads.
&&
.AVIATION...
(00Z TAFS)
Issued at 640 PM CDT Thu Oct 19 2023
Dewpoints in the mid to upper 60s have moved into the coastal
region behind a very weak sea breeze. A weak frontal boundary
south of a CLL-SAT line will drift south to near a VCT-COT line
by daybreak where it will stall. With light winds and high
boundary layer moisture over the coastal region, expect fog
with MVFR vsbys will develop around 10Z and continue through 15Z
Friday. SREF probabilities for LIFR vsbys increase along a line
from PKV-CRP-BKS by 12Z Friday with the latest HRRR model showing
potential for dense fog in this area. Placed a TEMPO for IFR
vsbys/LIFR ceilings at CRP from 10-14Z Friday. ALI and VCT are a
little more inland from the higher boundary layer moisture and
will only show a TEMPO for MVFR vsbys from 09-13Z Friday. VFR
conditions under clear skies are expected after 15Z.
&&
.MARINE...
Issued at 255 PM CDT Thu Oct 19 2023
Expect light and variable winds across the waters tonight through
tomorrow. Weak to moderate south to southeasterly flow is
expected over the weekend with a more moderate flow possible early
next week. Isolated to scattered showers return to the forecast
Monday night.
&&
.PRELIMINARY POINT TEMPS/POPS...
Corpus Christi 64 93 65 91 / 0 0 0 0
Victoria 57 94 60 93 / 0 0 0 0
Laredo 61 93 65 94 / 0 0 0 0
Alice 60 95 61 94 / 0 0 0 0
Rockport 65 91 67 86 / 0 0 0 0
Cotulla 60 96 63 95 / 0 0 0 0
Kingsville 62 94 64 92 / 0 0 0 0
Navy Corpus 69 90 70 86 / 0 0 0 0
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...None.
GM...None.
&&
$$
SHORT TERM...PH
LONG TERM....NP
AVIATION...TMT/89
Area Forecast Discussion
National Weather Service Goodland KS
504 PM MDT Thu Oct 19 2023
.SHORT TERM...(This evening through Saturday night)
Issued at 154 PM MDT Thu Oct 19 2023
Across the region this afternoon, with high pressure to our west,
and a low to our east, sunny skies prevail with a strong
northwesterly gradient impacting the area. Temperatures as of 100 PM
MDTre ranging in the upper 70s into mid 80s.
The latest RAP 500mb analysis and water vapor imagery do show a
persistent NW flow loft as an amplified ridge over the western
portion of the country remains dominant. Some areas are seeing gusts
into the 30-40 mph range this afternoon, drying some locales out
further. This is allowing for some Red Flag criteria to be reached.
RH values are dropping into the 13-15% range. No fires currently
impacting the CWA, but do expect some locales to see criteria (1-2
hrs) to be breached through sunset before tapering off.
For the Friday/Saturday timeframe, upper ridge will sink south going
into Saturday, allowing for NW flow aloft to go zonal. A weak front
does push through the region Friday night w/ high pressure lifting
north of the CWA. Surface flow going north Fri night to eventually
S/SE by Sat-Sat night. Overall dry wx ensues through the first half
of the weekend. Lighter winds Friday will allow for more heating
under full sunshine. Looking for well above normal numbers to be
reach, some close to records. Dry wx will also continue the threat
for elevated to near critical fire wx conditions area-wide. Please
refer to the Fire Wx section below for further information. Cooler
and dry for Saturday as ridge rolls through the Plains.
For temps, looking for highs on Friday to range mainly in the mid to
upper 80s. A few spots could even approach 90F. These highs could
allow for some locales to see record/near record numbers. Please
refer to the Climate section below for further information. Going
into Saturday, cooler with 70s expected area-wide. Overnight lows
will mainly range in the 40s for the short term period. Some upper
30s are possible Saturday night.
.LONG TERM...(Sunday through Thursday)
Issued at 109 PM MDT Thu Oct 19 2023
The latest runs of the GFS and ECMWF continue to bring broad upper
level ridging over the Plains region Sunday into next Monday, with a
shift from zonal to SW flow aloft. A weak shortwave/impulse does
ride through the northern periphery of the ridge Sunday
afternoon/evening. Both models do show some weak potential for
showers more so the ECMWF, but placement east of the CWA seems more
likely due to the inconsistency show between the two runs.
Going into Tuesday and on through Thursday, this timeframe continues
to show increased chances for rain. A cutoff upper low digging into
the 4-Corners region Tuesday, then meandering slowly east into the
southern Plains. Surface front ahead of this low will be the focus
for increased low level moisture/instability to trigger showers. As
with previous runs, the placement of the front continues to have the
eastern CWA seeing best chances for rain. Some wrap-around moisture
Wed night-Thursday will bring low chances to northern zones before
ending.
A second low will move E/SE from the northern Rockies Thu-Thu night,
but track mainly north of the cwa. The northerly flow behind the
aforementioned front w/ high pressure digging south could trigger
some lingering light precip. Colder air does work south by Thursday
night. Most if not all moisture should be east of the CWA by then.
Potential for some light snow showers to form in Yuma county, but
for now have left out. Temps will drop below freezing, but the
airmass does dry out further due to the progression of the ridge
southward, but should be monitored nonetheless.
For temps, the region will looking for daytime highs on Sunday to
peak only into the upper 60s to the lower 70s. A slightly warmer day
for next Monday with a range from the mid 70s into the lower 80s.
With a frontal passage bringing CAA, clouds and precip, mainly 60s
for highs from Tuesday onward are expected. Some locales on Thursday
in northeast Colorado could only see the upper 50s.
Overnight lows Sunday night will range from the upper 30s into the
mid 40s. With colder air working into the region overnight(s), a
range from the upper 30s west to the upper 40s east is expected.
Colder air arrives Thursday night upper 20s west into the lower/mid
30s east on tap.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 503 PM MDT Thu Oct 19 2023
VFR conditions are anticipated to prevail through the forecast
period at both KGLD and KMCK. Northwesterly winds near 10 knots to
start out with will back to become more westerly, remaining light in
the 5-10 knot range overnight and into the morning. By ~19Z, winds
return slightly more northwesterly near 10 knots sustained with
occasional gusts in the teens.
&&
.FIRE WEATHER...
Issued at 154 PM MDT Thu Oct 19 2023
Friday...the entire region will see humidity values drop into the
lower and mid teens. West to northwest winds with gusts up to the 20
mph range are expected. Strongest gusts to remain along/west of
Highway 27 and combined with low RH potential, will create elevated
to near critical fire conditions.
&&
.CLIMATE...
Issued at 154 PM MDT Thu Oct 19 2023
Here are the record high temperatures for Friday, October 20th:
Goodland, KS 89F in 2007+
McCook, NE 89F in 1947
Burlington, CO 90F in 1921
Hill City, KS 94F in 1947
Colby, KS 95F in 2003
Tribune, KS 94F in 2003
Yuma, CO 89F in 2003
A (+) symbol denotes a record in multiple years.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...JN
LONG TERM...JN
AVIATION...CC
FIRE WEATHER...JN
CLIMATE...JN
Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
922 PM EDT Thu Oct 19 2023
.SYNOPSIS...
A cold front approaches from the west tonight and crosses our area
on Friday. Expect breezy conditions behind the front through
Saturday. Dry high pressure slowly builds in through the weekend
and remains in place through the middle of next week.
&&
.NEAR TERM /THROUGH FRIDAY/...
As of 9:20pm EDT Thursday: Only a light touch needed for this
update as things remain on track. A few traces of rain did manage
to hit the ground up in Western NC, but radar is now nearly clear.
Partly cloudy tonight and light winds will eventually give way to
FROPA. Front is currently over Western TN and is on track to begin
affecting the GSP CWA around 3am with some light showers entering
the Southern Applachians, moving eastward. Showers will generally
move with the front, with some thunder still possible with a bit of
surface CAPE in the afternoon in areas still ahead of the front.
The main concern for this forecast is the passage of a relatively
deep mid/upper trof and associated cold front and what might happen
as the front passes. The trof axis is expected to make slow but
steady progress to the east overnight as an upper low closes off
over the Great Lakes. Oddly enough, the forcing shown in the
model guidance looks weaker than one might expect with such a
feature. Nevertheless, the guidance shows this system making the
most of what its got with a well-timed increase in low level SW
flow bringing more moisture in from the SW ahead of the front to
develop a band of showers and maybe a few embedded thunderstorms
over the TN valley late tonight. Warm advection and increasing
cloud cover overnight should keep low temps above normal. This
band of precip would spread east over the mtns in the pre-dawn
hours and then move east of the mtns after daybreak. The initial
activity warrants a likely to categorical prob over the mtns,
but the relatively weak forcing precludes much more than a low-end
likely prob east of the mtns as it crosses thru late morning. After
that, the situation gets more interesting. The model guidance has
been showing a break in the action between the departing morning
rain and the arrival of the main cold front in the late afternoon,
long enough to allow some air mass recovery over at least the lower
Piedmont up to the Charlotte metro area. The RAP shows a plume of
sfc-based CAPE of nearly 1000 J/kg lifting northeast over the area
east/southeast of I-85 in the afternoon, along with effective shear
of nearly 30 kt. Altho the trend on the shear has been downward
as of late, the trend on the buoyancy has been upward. As we have
said in the past, we`ve done more with less. The 12Z HREF looks
somewhat compelling with reflectivity features developing ahead
of the front in the mid/late afternoon east of the mtns that would
suggest a low-end wind damage threat over the east. Both the HRRR
and NAMNest have some 30kt-ish wind gusts, so that suggestion
seems plausible. The severe weather prospects are conditional on
the development of the instability, but things being what they are,
an upgrade to the Day 2 risk to Marginal is warranted. The lack of
well-organized mid/upper forcing will probably be limiting factor
in keeping this from being something more significant. The storms
should move east by the early evening. Temps will turn out on the
warm side of normal most likely, at least east of the mtns.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
As of 139 PM EDT Thursday: A very dry airmass will arrive Friday
night, with axis of min thicknesses crossing the region around
daybreak Saturday. Even so, H850 temps won`t get cold enough to
warrant any snow embedded in the NW flow showers that develop in
the mountains that morning. Following a period of breezy winds
lasting well into Saturday afternoon, weakening high pressure
will slide across the Southeast, sandwiched beneath a weak and
moisture-starved clipper shortwave dipping across the VA Blue
Ridge Saturday night. Thereafter, heights will begin to rise and
sfc high pressure will become established. Temps will be up to a
category above normal on Saturday, falling to at least a category
below normal Saturday night and Sunday.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
As of 201 PM EDT Thursday: The upper pattern will become less
amplified Sunday night and afterward with broad ridging extending
from the Gulf of Mexico into much of the eastern CONUS. The
northern stream will fail to dislodge this ridge through at least
Thursday, such that dry high pressure will become established over
the Carolinas for the entirety of the extended period. After the
coolest temps on Monday morning, which may even support frost over
the mountains and foothills, temperatures will gradually warm
through the period as high pressure deepens, to at least 1-2
categories above normal by Thursday.
&&
.AVIATION /02Z FRIDAY THROUGH TUESDAY/...
At KCLT and elsewhere: This evening, stratocu deck has mostly
dissipated following the end of the days solar heating, with some
high clouds remaining ahead of next incoming storm system. Winds
are light and generally southerly to southwesterly. Main forecast
issue will be the progress of a storm system that is expected to
give some thunder Friday afternoon along a cold front, the passage
of which will also veer winds to become gusty westerly and
northwesterly. Current guidance has a line of weak showers passing
through Friday morning followed by a short period of an hour or 2
prior to frontal passage around 18Z with chances for storms and wind
changes with the FROPA. Active showers at times will give MVFR (or
lower) conditions due to reduced visibility.
Outlook: The cold front will pass across the region in the late
afternoon and early evening Friday. Gusty winds will remain in
place Friday night thru late Saturday. However, drier conditions
will return Saturday into early next week as high pressure builds
in behind the departing cold front. Mountain valley fog and low
stratus will be possible each morning around daybreak.
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...None.
NC...None.
SC...None.
&&
$$
SYNOPSIS...DEO
NEAR TERM...PM/WJM
SHORT TERM...MPR
LONG TERM...MPR
AVIATION...WJM
Area Forecast Discussion
National Weather Service Huntsville AL
951 PM CDT Thu Oct 19 2023
...New NEAR TERM...
.NEAR TERM...
(Rest of tonight)
Issued at 951 PM CDT Thu Oct 19 2023
Isolated, very light showers continue to shift eastward across
the TN Valley this evening, within the warm/moist sector to the
east of a amplifying mid-level trough. Embedded within this
dynamic system, a 125-135 knot high-level speed max is predicted
to dig south-southeastward from northeastern IA into upper
portions of the TN Valley by 12Z, and enhanced UVMs beneath the
left exit region of this feature are likely responsible for both
an axis of light convective showers extending from southern IN
into northwestern TN, as well as a recent intensification of
deeper convection (capable of producing lightning) along the
surface cyclone`s cold front (extending from southern KY into
northern Middle TN).
Although recent trends in radar data suggest that the frontal
convection may tend to backbuild further southwestward with time
late this evening, present indications are that activity should
largely miss our forecast area to the north/east (perhaps only
grazing our southern Middle TN counties). Thus, we have reduced
the spatial coverage of thunderstorms in the updated weather
grids, and confined this to locations generally along and north of
the TN River. We also made a minor reduction to POPs for the
entire CWFA, but left a medium (40-50%) chance for measurable
precipitation in place north of the river, mainly due to
extrapolation of light postfrontal showers to our northwest. Low
temperatures were also increased a degree or so (mainly for
outlying portions of the local area), due to the anticipated
coverage of mid-level clouds overnight and existence of a SSE wind
of 5-10 knots.
&&
.SHORT TERM...
(Friday through Sunday)
Issued at 143 PM CDT Thu Oct 19 2023
The aforementioned upper trough looks to pivot towards the
northeast through the weekend, with an upper ridge building into
the region from the west. At the surface, a reinforcing cold
front is expected to quickly move through the Tennessee Valley
later on Saturday, with high pressure taking hold by late weekend.
The bulk of the shower and storm activity likely will have moved
east of the local area by Friday morning, with only 10-20% PoPs
possible over our far northeast Friday morning. By Friday
afternoon, dry weather will take hold area-wide and persist
through the weekend. Breezy conditions will also continue, as
sustained northwest/west winds to around 15 mph and gusts to
between 20-25 mph are possible Friday and Saturday (particularly
during the day). Winds are then expected to slacken some by
Sunday.
Temperatures will gradually increase to be in the upper 70s for
much of the local area by Saturday. However, cooler conditions
will follow the second cold FROPA, leading to highs merely
topping out in the upper 60s to lower 70s on Sunday. Lows are
forecast to mainly be in the 40s through Saturday night.
&&
.LONG TERM...
(Sunday night through Wednesday)
Issued at 315 AM CDT Thu Oct 19 2023
143 PM Update - not too much has changed with the long term
forecast. The main difference from the midnight shift is that
model guidance have come into better agreement with a drier
forecast through Wednesday night. At this point, the next chance
at rain (albeit low, 15-20%) is Thursday.
High pressure will dig south across the Great Lakes region on
Sunday behind a cold front. Will notice these cooler temperatures
as afternoon highs will be about 10 degrees lower than the
previous day, only reaching the upper 60s/lower 70s. Sunday night
will feature the coldest temperatures in the forecast for now,
with lows falling into the lower 40s in the higher terrain of
southern middle TN and northeast AL, then mid 40s elsewhere. As
upper ridging builds aloft, will see temperatures warm slightly
through the first half of the work week, with afternoon highs
rising into the low to mid 70s and overnight lows largely in the
50s. Dry conditions will persist through at least Wednesday
morning, with low (20%) chances for rain over northwest AL
Wednesday evening. Given model discrepancies at this range, have
stuck with NBM for PoPs but may need to be adjusted in future
updates as models come into better agreement. No relief in sight
to the ongoing drought, but temperatures do look quite nice for
late October.
&&
.AVIATION...
(00Z TAFS)
Issued at 637 PM CDT Thu Oct 19 2023
Recent trends in Doppler radar data suggest that a few showers
will continue to progress eastward across northern AL this
evening, ahead of a sfc trough. However, at this time, it appears
as if coverage will remain rather low invof the terminals and we
have decided to only include VCSH in the prevailing line thru
2Z/MSL and 4Z/HSV based on latest output from the HRRR model.
Furthermore, the risk for deeper updrafts capable of generating CG
lightning flashes appears as if it will remain confined to Middle
TN, and we will not mention VCTS, but will monitor conditions in
the event that AWWs may be warranted. Mid-lvl clouds will become
bkn-ovc in nature in the wake of the trough axis, with some lower
(MVFR-lvl) stratus and light postfrontal rain possible around 12Z.
However, this should be displaced to the N/E of the terminals and
will create no impacts at HSV or MSL. Skies will rapidly clear
from W-to-E over the course of the morning, with winds veering to
NW and increasing to 10G18 knots by 15Z.
&&
.HUN WATCHES/WARNINGS/ADVISORIES...
AL...None.
TN...None.
&&
$$
NEAR TERM...DD/RAD
SHORT TERM....26
LONG TERM....26
AVIATION...DD/RAD
Area Forecast Discussion...UPDATED
National Weather Service Indianapolis IN
708 PM EDT Thu Oct 19 2023
.Forecast Update...
Issued at 708 PM EDT Thu Oct 19 2023
Showers are confined to flank of DPVA/ascent from first wave, now
departing our southeast counties, and northern Illinois in response
to ascent from the second low-amplitude shortwave trough. It appears
upstream ascent will maximize and interact with residual moisture
for greatest shower coverage after midnight and through the predawn
hours. Current forecast handles this well and no significant
adjustments were needed.
&&
.Short Term...(This evening through Friday)
Issued at 259 PM EDT Thu Oct 19 2023
- Cloudy with rain possible tonight.
- Rain ending on Friday with decreasing clouds in the afternoon.
Surface analysis this afternoon shows low pressure centered over the
Michigan Upper Peninsula. The low was providing cyclonic flow across
the Great Lakes and Indiana. Central Indiana was still residing in
the warm sector. An associated cold front was found extending from
the low across Central WI to SE IA. Another trough within the
cyclonic flow was found over Eastern IL and radar showed an area of
showers over western Indiana ahead of this feature. Water Vapor
showed strong ridging in place over the western United States, while
a trough axis was found from the western Great Lakes to the Wabash
valley and extending south to Mississippi. A plume of tropical
moisture was found ahead of the trough streaking across OH and PA.
Otherwise GOES16 shows cloudy skies across Indiana and Illinois.
Tonight...
Models show the deep upper trough axis remaining over Indiana
through the night. This will be the main weather feature through
tonight. As the upper trough axis slowly pushes across the region,
the associated surface low also slowly pushes across the Great
Lakes, keeping lower level cyclonic flow across Central Indiana.
HRRR shows this afternoons band of showers exiting the area prior to
00Z, but overnight, spotty, very light showers are depicted
overnight as the upper trough axis digs over Central Indiana.
Forcing with the wave aloft appears to be weak, but forecast
soundings and time heights show plentiful moisture within the column
through the night. Thus will trend toward a cloudy sky, and keep
some low to moderate pops across the forecast area due to the weak
forcing and plentiful moisture. Best pops will be across the
northern parts of the forecast area where forcing appears best as
depicted by the HRRR. Overall, any precip amounts should be rather
light.
Regarding temps, the cold front associated with this system
continues to remain west of Indiana through the morning. Thus we
will remain within the warm sector overnight and lows in the lower
50s will be expected.
Friday...
On Friday the upper trough axis is shown to finally begin to exit
Central Indiana. Weak ridging aloft builds across the upper midwest
during the afternoon, while much strong ridging within the lower
levels builds across Illinois and Indiana within the mid level flow,
promoting subsidence. Forecast soundings show this, particularly
showing strong drying within the afternoon, with eventually an
unsaturated column by 00Z Sat. Thus after a cloudy start to the
stay, with perhaps lingering showers across the area, we will trend
toward a decreasing cloudiness type sky cover particularly in the
afternoon. The cold front is suggested to pass during the morning
hours, but cold air advection appears limited as 850mb temps remain
in a rather steady state around 4C. Ultimately this will lead to
highs on Friday in the upper 50s to near 60.
&&
.Long Term...(Friday night through Thursday)
Issued at 259 PM EDT Thu Oct 19 2023
* Breezy and mild Saturday
* Potential for frost Monday morning
* Warmer next week with chances for rain mid to late week
.This Weekend...
The long term period begins with weak and quick ridging developing
over the region ahead of another weak, moisture starved wave diving
southward from Canada. Despite a surface ridge drifting across the
Ohio Valley late Friday night, RH progs and model soundings continue
to show the presence of a shallow but notable inversion with a
likelihood that low stratus persists into early Saturday morning.
Continued the trend of the previous forecaster and nudged cloud
coverage up from the model blend/ The aforementioned wave and
associated surface low will dive out of the Canadian prairies and
across the lower Great Lakes early Saturday with the potential for
another round of scattered showers focused especially across the
northeast half of the forecast area through the first half of the
day. For much of central Indiana however, the frontal passage will
be defined by a brief increase in clouds and gusty winds to 20-30
mph, especially as cold advection develops within the postfrontal
airmass with winds veering to northwest. Low level thermals do
support a mild day in the 60s before the cooler air arrives.
Dry and cool weather will follow for Sunday as high pressure expands
into the region. Highs on Sunday will range from the mid 50s to
around 60 from northeast to southwest. There remains a growing risk
for frost Sunday night and Monday morning as the center of a high
pressure system slides south into the region on the back side of the
strong storm system over New England. Optimal conditions for
radiational cooling should be maximized as the high builds overhead,
winds lighten, and skies largely remain clear. Low to mid 30s look
increasingly likely for Monday morning focused particularly across
the northeast half of the forecast area. In coordination with
surrounding offices, have added patchy frost for much of the
northern and eastern half of Central Indiana. Left frost out of most
of Indianapolis as the urban heat island effect may keep low
temperatures just high enough to prevent frost.
.Next Week...
The expansion of broad ridging aloft by early next week as the deep
upper low over New England moves off to the east in tandem with
developing return flow on the back side of high pressure will bring
warmer air into the region. Highs will rise to above normal levels
for Tuesday and Wednesday with low to mid 70s as strong southwest
flow develops. The presence of a lingering surface ridge will keep
an approaching front to our north through midweek but eventually
this will drift into the area mid to late next week bringing the
next threat for rainfall. Latest 12z guidance is in agreement with
holding back precipitation until Thursday or Friday, so have lowered
PoPs from what the NBM had for Wednesday and Wednesday night and
raised max temps for that period. While timing differences remain
this far out within the various pieces of the model suite, growing
confidence that the passage of the front will usher in potentially
the coolest air of the Fall by next weekend as a strong upper level
trough takes hold over the Northern Plains and expands south and
east.
&&
.Aviation...(00Z TAF Issuance)
Issued at 550 PM EDT Thu Oct 19 2023
Impacts:
* Periodic showers through early Friday
* MVFR ceilings, possibly IFR
Discussion:
Uncertainty with regards to MVFR vs IFR ceiling heights early Friday
morning are the largest source of forecast uncertainty this TAF
cycle. MVFR ceilings are likely and we extended the end time later
into Friday. Showers are possible at any point through Friday
morning but may be most concentrated later tonight through the
predawn hours, when the second shortwave trough approaches. Gradient
may be enough to support 12-15 knot winds Friday, with gusts to 20-
25 knots.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
Update...BRB
Short Term...Puma
Long Term...CM
Aviation...BRB
Area Forecast Discussion
National Weather Service Morristown TN
917 PM EDT Thu Oct 19 2023
...New UPDATE...
.UPDATE...
Issued at 910 PM EDT Thu Oct 19 2023
Currently a line of scattered showers with some embedded
thunderstorms is making its way across Middle Tennessee and
central Kentucky. Storms are losing some of their intensity as
they move eastward with the sun having set, but cannot completely
rule out seeing a brief wind gust up to 30 mph or possibly a bit
of pea size hail before midnight. Coverage of these storms should
remain fairly scattered to isolated with some places unfortunately
missing out on the needed rainfall. Outside of some minor tweaks
to the timing of the incoming precipitation and PoPs no major
changes have been made to the forecast for the rest of the
evening.
&&
.SHORT TERM...
(This evening through Friday)
Issued at 241 PM EDT Thu Oct 19 2023
Key Messages:
1. Band of showers tonight, additional scattered showers and a
couple thunderstorms possible Friday afternoon.
2. Additional breezy winds tomorrow, with afternoon gusts of 20 to
25 mph possible.
Discussion:
Current radar shows light rain falling along the Tennessee Alabama
border. This cluster will move east and pass through the
southernmost counties in East Tennessee over the next couple of
hours. Observations in the area have very light precip making it
to the ground, so not expecting much out of this.
This evening a large trough axis will pass by, and a 130 knot jet
streak will be punching southwards over the Upper Mississippi River
valley towards the Mid-South. In response, strengthening low
level flow will spur isentropic lifting and generate a band of
showers that will move across Tennessee tonight, bringing light
but measurable rainfall for at least a couple hours to a wide
portion of the area.
After daybreak on Friday, 850 flow pivots from parallel to the
Appalachians to more of an upslope flow regime as a cold front
passes by. Simultaneously we`ll have some better dynamics
arriving, with lower heights and steepening lapse rates resulting
in 300-500 MLCAPE. The HRRR and HREF takes this and produces
scattered convection, primarily in the central TN valley and
north, which will bring additional rainfall and possibly a few
rumbles of thunder in stronger cells. Rain chances will diminish
with time into the late afternoon and evening as cells move
eastward into the mountains. Strong mixing behind the front should
yield another afternoon of breezy winds, especially in the
Knoxville metro and south.
&&
.LONG TERM...
(Friday night through next Thursday)
Issued at 241 PM EDT Thu Oct 19 2023
Key Messages:
1. Windy Saturday afternoon, for both the valley and the mountains.
Strongest valley winds likely north of the I-40 corridor.
2. Dry and mild for Sunday onward, with temperatures warming a
few degrees above normal by mid week.
Discussion:
The main message for the long term period is going to be an extended
period of dry and tranquil weather. There is a little bit of weather
to contend with Saturday, with widespread breezy conditions
expected. But by Sunday we dry out and begin to warm up, with that
trend continuing through likely the end of next week.
Friday night into Saturday will see northwest aloft set up overhead
as we lie between a departing trough and a digging trough/shortwave
over the upper midwest. This dives southeast through the day, with a
surface low developing over Iowa and tracking southeast through
Kentucky during the day. Will keep some low PoPs going over the
northern mountainous terrain Fri night into Sat. But, I have to say
that guidance has come in considerably more dry than this time
yesterday so wouldn`t be surprised if there`s little to no rainfall
in our CWA after 00z Sat. Main forecast concern for this system will
be the winds on Sat. Tightening surface pressure gradients and H85
flow climbing above 35kt, combined with sufficiently deep mixing to
bring those winds to the surface, will create windy conditions
across the forecast area Sat afternoon. Guidance has lowered winds
ever so slightly over the last 24 hrs, but it`s going to be a windy
day. Gusts of 30 mph may be within reach in the lower elevations
north of the I-40 corridor, especially the northern TN valley and
southwest VA counties. Meanwhile, gusts of around or slightly over
40 mph could occur in the mountains. Will need to consider some wind
related headlines, most likely an advisory, if these trends continue
tonight but it is a little too far out to hoist them up with the
afternoon package.
Aforementioned shortwave and surface low are east of the area by
midnight Sat night, giving way to dry conditions through the end of
the period. Northwesterly upper flow continues on Sun as the
synoptic scale upper trough/closed low pushes east of the Great
Lakes. But by Monday upper ridging builds overhead as a ridge
strengthens over the northern GOMEX and Florida panhandle, which
lasts through the end of next week. After being well below normal on
Sunday with cool northerly flow from the surface high to our north,
temperatures will rise to 3-5 degrees above normal by Wed as high
pressure builds overhead.
&&
.AVIATION...
(00Z TAFS)
Issued at 714 PM EDT Thu Oct 19 2023
Line of showers expected to move through nearing midnight, but it
will likely be a broken line so have gone with VCSH and a TEMPO
group during the most likely period for showers to impact the
airports. Cannot completely rule out brief isolated
thunderstorms, but have kept -RA in the TAFs for now since its
more likely that it`s just rain. Rain chances will continue
tomorrow along with increasing winds out of the west. Have kept
broad periods of rain in the TAFs to keep the length down and will
go into more detail as we approach tomorrows rain chances.
&&
.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN 57 72 47 77 / 80 40 0 0
Knoxville McGhee Tyson Airport, TN 55 65 46 72 / 90 80 10 0
Oak Ridge, TN 54 65 44 73 / 90 80 0 0
Tri Cities Airport, TN 51 60 46 66 / 90 90 30 0
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&
$$
SHORT TERM...
LONG TERM....CD
AVIATION...