Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 12/04/23
Area Forecast Discussion...CORRECTED
National Weather Service Dodge City KS
544 PM CST Sun Dec 3 2023
...Updated Aviation Discussion...
.KEY MESSAGES...
- Strong northwesterly winds will impact southwest KS Sunday in
the wake of a cold front, with sustained winds in the 25-35 mph
range and gusts up to 50-55 mph.
- Warming trend will commence Monday through Thursday, with
temperatures potentially nearing record highs Thursday.
- Ensembles have trended significantly down regarding
precipitation potential this weekend.
&&
.SHORT TERM...(This evening through Monday night)
Issued at 200 PM CST Sun Dec 3 2023
Midday water vapor satellite imagery and RAP upper air analysis
reveals longwave troughing encompasses the entire CONUS, with a
pair of embedded shortwave troughs over the Midwest and central
plains. At the surface, a cold front is in the process of moving
through southwest KS associated with a low pressure system
centered near Grand Island, NE, with considerable northwesterly
winds in its wake. Surface observations in the post-frontal zone
indicate sustained winds in the 25-35 mph range with gusts of
50-55 mph are ongoing, and these will affect all zones over the
next few hours. Reduced visibility was also reported owing to
blowing dust as a result of these strong winds, so introduced
some patchy blowing dust to the weather grids for this afternoon.
Thankfully, very little cold air exists behind the front, and with
at least some sunshine, afternoon highs will reach the low 50s
north to upper 50s near the KS/OK border. After sunset, winds will
rapidly weaken with the loss of boundary layer mixing, reaching
the 5-15 mph range by midnight tonight. The combination of light
winds and clear skies will support overnight lows dropping into
the upper teens northwest to upper 20s southeast.
Daytime Monday, short range ensembles suggest the upper level
longwave trough will translate east as longwave ridging builds
over the western CONUS. Surface high pressure ahead of the upper
ridge will develop over the southern plains, with anticyclonic
flow causing southwesterly, downsloping winds across our area.
Adiabatic compression and abundant solar insolation will foster
the continuation of the warming trend, with afternoon highs
reaching the low 60s. Monday night, another upper level shortwave
trough on the western periphery of the longwave trough will dive
southeast out of the northern plains, sending another cold front
through the central plains. While northerly winds will be much
weaker behind this boundary compared to Sunday`s front, sufficient
mixing overnight will result in a slightly warmer night as lows
only drop into the low 20s northwest to low 30s southeast.
.LONG TERM...(Tuesday through Sunday)
Issued at 200 PM CST Sun Dec 3 2023
Medium range ensembles agree upper level longwave ridging will
gradually shift from the western CONUS to the High Plains Tuesday
through Thursday while dampening. Following a brief halt to the
warming trend owing to Monday night`s cold front, the warming
trend will resume as afternoon highs increase from the upper
50s/low 60s Tuesday to the upper 60s/low 70s on Thursday with no
chance for precipitation. Friday into the weekend, ensembles
suggest decreasing 500-mb heights will result in a cooling trend
as longwave troughing once again begins to overtake the CONUS,
aided by a cold front attached to a deep surface low ahead of a
strong upper level shortwave trough over the upper
Midwest/southern Ontario diving south through the central plains.
Afternoon highs will drop from the upper 50s/low 60s Friday into
the 40s and 50s Saturday and Sunday.
Unfortunately, latest ensembles have trended down substantially
regarding precipitation associated with the strong upper level
wave that will reach the central plains on Saturday. Probability
of QPF exceeding 0.1" is now in the 0-20% range off both the EPS
and GEFS, with fewer than half of their members resolving
precipitation. Furthermore, the deterministic counterparts mirror
this change, with the 12Z GFS depicting a dry weekend and the 12Z
ECMWF showing only a paltry QPF signal. Nevertheless, ensemble
trends will continue to be monitored as predictability at this
forecast range is generally low.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 505 PM CST Sun Dec 3 2023
Northwest winds at 10 to 15 knots this evening will decrease to
less than 10 knots over the next few hours as a surface high
builds into southwest Kansas and the atmosphere decouples. Light
northwest winds overnight will back to the southwest by early
Monday morning. These southwest winds will increase to around 15
knots after 15z Monday. VFR conditions can be expected over the
next 24 hours based on latest BUFR soundings and HREF
probabilities for VFR conditions being 100%.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 24 61 30 60 / 0 0 0 0
GCK 21 59 26 58 / 0 0 0 0
EHA 24 62 26 62 / 0 0 0 0
LBL 22 60 25 61 / 0 0 0 0
HYS 22 60 28 56 / 0 0 0 0
P28 27 59 33 58 / 0 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Springer
LONG TERM...Springer
AVIATION...Burgert
AREA FORECAST DISCUSSION
National Weather Service Eureka CA
256 PM PST Sun Dec 3 2023
.SYNOPSIS...Heavy rainfall continues to impact northern Humboldt and
Del Norte counties this afternoon through late tonight. Gusty
ridgetop winds are also accompanying the heavy rain. Additional
light to moderate rainfall is expected early next week, with a
stronger system with the potential of heavy rainfall to occur during
mid week.
&&
.DISCUSSION...Moisture flux associated with a moderately strong
atmospheric river has dropped southward toward Del Norte county
today to bring another round of moderate to heavy rain, mostly for
northern Humboldt and Del Norte Counties. Gusty southerly winds
from 25 to 40 mph are being recorded over the more prominent
coastal headlands and higher terrain across the northern portion
of the region. Late morning RAP mesoanalysis verified anomalous
PWAT values at 1-1.25 inches along the Far North Coast. Additional
rainfall amounts will be 1 to 2 inches for Del Norte and far
northern Humboldt counties from today through late tonight, with
locally higher amounts over higher terrain in Del Norte.
Maintained the Flood Watch for urban/small streams across Del
Norte and the northern portion of Humboldt counties, though it may
require trimming from the southern portion. Elsewhere, lighter
total amounts will range from few hundredths to half of an inch.
Moist onshore flow then continues into early next week and will aid
in additional shower activity. PWATS will remain anomalously high on
Monday, but the highest moisture flux will be north of the CWA, and
there will be more of an easterly component to the low level
winds. This will limit the potential for heavier precipitation
rates on Monday, but the soils will remain nearly saturated to
saturated over the Far North Coast. A stronger frontal system is
forecast to advance east across the NERN PAC as well, with hydro
hazards generally focused over WA/OR Monday night into Tuesday.
The front is then forecast to slide south toward NWRN CA Tuesday
night into Wednesday. A midlevel shortwave impulse may interact
with the front and yield an increase in precipitation rates as the
front moves onshore across the EKA CWA. After Wednesday, a
progressive upper flow regime is forecast to persist and aid in
additional rainfall, along with colder temperatures and some
mountain snow. ZVS/JJW
&&
.AVIATION...Conditions have stayed mostly VFR/MVFR today. There were sporadic
bouts of rain, especially over Del Norte where weather had a "yo yo"
effect: up and down from VFR-IFR. Impactful weather can be expected
for ACV and CEC through afternoon/evening as model data continues a
trend of rain for the northern areas; lesser amounts over Mendocino
and Lake Counties. Added the possibility of mostly directional low
level wind shear (LLWS) at CEC...which may be more concerning for
general aviation. Also, gusty southerly winds will continue at CEC
due a pronounced pressure gradient flow. Precipitation should remain
simply "RA", but a few embedded "SHRA" not out of the question
today. /TA
&&
.MARINE...Southerly winds gusting up to 30 kts will continue
through tonight, mainly focused in the northern zones. The southerly
winds will increase on Monday when gusts with near gale strength in
isolated northern areas. The southerlies will strengthen again
early Tuesday along a dynamic frontal system. A northwest swell
peaked this afternoon in the 12 to 15 foot range at 14 seconds.
The first of two long period west- northwest swells will build
tonight and through Monday, to the mid teens at 18 seconds. A
second larger, long period swell will then begin filling in on
Tuesday, peaking early Wednesday in the upper teens at 18 to 19
seconds.
&&
.HYDROLOGY...Additional moderate to heavy rainfall with a
moderately-strong atmospheric river will continue to impact the
northern portion of the CWA today. 24 hours total rainfall amounts
are forecast to range from 1 to 2 inches in Del Norte and far
northern Humboldt counties. More flash flooding impacts are
likely today mainly across Del Norte County due to additional rain
falling in a short amount of time. CREST soil moisture profile
continues to show the terrain to be saturated. As result, the
additional rainfall today will more quickly develop urban and
small stream flooding, or even flash flooding. In addition, small
rock and mud slides are possible in areas of steep terrain that
are already saturated. Reference the latest flood hazard products
for more information. /ZVS
&&
.BEACH HAZARDS...A long period northwesterly swell will begin to
build in through the coastal waters tonight, and will continue to
build into Monday to around 14 feet at 18 seconds. This swell will
be sufficiently powerful enough for sneaker waves from significant
set behavior and beach runup. Large, unexpected waves can sweep
across the beach without warning, sweeping people into the sea from
rocks, jetties, and beaches. These sneaker waves can also move large
objects such as logs, crushing anyone caught underneath. A second
larger, long period swell will then begin filling in on Tuesday,
peaking early Wednesday in the upper teens at 18 to 19 seconds. This
will generate High Surf Advisory level surf breakers up to 25 feet
Tuesday afternoon through Wednesday.
&&
.EKA WATCHES/WARNINGS/ADVISORIES...
CA...
Flood Watch through late tonight for CAZ101>103-105-106.
Beach Hazards Statement from Monday morning through Monday
afternoon for CAZ104-109.
NORTHWEST CALIFORNIA COASTAL WATERS...
Small Craft Advisory until 9 PM PST this evening for PZZ450.
Small Craft Advisory until 3 AM PST Monday for PZZ455-475.
Small Craft Advisory until 9 PM PST Monday for PZZ470.
&&
$$
Visit us at https://www.weather.gov/eureka
Follow us on Facebook and Twitter at:
https://www.facebook.com/NWSEureka
https://www.twitter.com/NWSEureka
For forecast zone information
see the forecast zone map online:
https://www.weather.gov/images/eka/zonemap.png
Area Forecast Discussion
National Weather Service Sioux Falls SD
728 PM CST Sun Dec 3 2023
.KEY MESSAGES...
-Areas of dense fog expected overnight into early Monday, mainly
east of the James River, and possibly expanding east into the
I-29 corridor and portions southwest Minnesota/northwest Iowa.
-More light snow chances (30%-40%) return Monday afternoon
mostly along the Hwy-14 corridor and Buffalo Ridge. However,
accumulation amounts should range from a trace to a few
tenths.
-Elevated fire weather concerns return Monday afternoon mostly
along and west of the James River.
-Above normal temperatures will continue for the remainder of
the week with the warmest conditions expected on Wednesday &
Thursday.
&&
.UPDATE...
Issued at 725 PM CST Sun Dec 3 2023
While we still have a widespread low cloud deck east of the
James River this evening, web cam imagery shows the coverage of
dense fog has increased quickly after sunset along and west of
these low clouds. Have issued a Dense Fog Advisory for a wedge
from roughly the James River Valley into the Highway 81 corridor
through early Monday morning.
Expect coverage of the lowest visibility to change through the
overnight as a light westerly flow becomes more prevalent, and
additions/subtractions to the advisory area are possible.
&&
.DISCUSSION...
Issued at 235 PM CST Sun Dec 3 2023
Rest of the Evening/Tonight:
A dreary day continues! Taking a look at satellite imagery, a
combination of low-level stratus and lingering patchy to dense fog
have limited our mixing and kept things on the drearier side for
most of the day. Expect the drearier conditions to continue for the
remainder of the afternoon before things clear our overnight with
the passage of a weak surface boundary this evening. With lighter
winds expected overnight with the arrival of a weak ridge, expect
another round of fog to develop in areas along the Hwy-81 corridor
and eastwards. Similar to today, some fog could be locally dense
with visibilities between 1-2 miles or less possible at times
especially in open areas and along the our river valleys. Otherwise,
depending on how soon things can clear out; temperatures will
gradually drop into the low to mid 20s for the night.
The Extended Forecast (Monday-Saturday):
Heading into the start of the work week, more light snow chances
return as a clipper system moves into the region from the northwest
along with a surface cold front. Looking aloft, mid-level warm air
advection (WAA) begins to strengthen ahead of the shortwave as more
moisture advects into region along the cold front. This along with
strong PVA and 850:750 frontogenesis should be enough to get trigger
a few flurries to light snow showers Monday afternoon and evening
along the Hwy-14 corridor and Buffalo Ridge. As far as amounts go,
the GEFS, Euro, and Grand ensemble members show medium to high
confidence that amounts should varying between a trace to a few
tenths with the higher amounts expected along a Brookings to Windom,
MN line. Nonetheless, snowfall amounts will remain below an inch for
most of the area with most of the activity clearing out before
sunset.
Otherwise, the SPG will tighten behind the cold front
causing northwesterly winds to become breezy to strong especially
west of the James where wind gusts between 35-45 mph will be
possible. After further discussion with neighboring offices, we`ve
decided to hold off on any wind headlines for now at least until the
next round of guidance arrives. Lastly, the combination of mild and
breezy conditions will lead to some elevated fire weather concerns
west of the James Monday afternoon. However, with the cold front
expected to pull through in the afternoon; there is some uncertainty
as to if we can get clear enough to get to those milder conditions
in the previously outlined areas. Unfortunately, its just one of
those situations where we`ll just have to wait and see. Shifting
gears to temperatures, expect daily highs to peak in the upper 30s
to low 50s with the warmest conditions expected in our far western
counties.
As cooler air continues to funnel into the area on Tuesday, a
pattern shift is on the horizon as a strengthening upper level ridge
arrives to the region bringing a much needed dose of mid-level WAA.
This will work to bring our 850mb temperatures back into the 8-12
degree C range on both Wednesday and Thursday which is between the
97.5th and 99th percentile of climatology. With this in mind, a
small warming trend will set up as daily highs shift from upper 30s
to lower 40s on Tuesday to the low 50s to mid 60s by Wednesday and
Thursday which is unseasonable warm for this time of year! Depending
on if these temperatures actually come to fruition, there is a
decent chance that we could tie or break a few new record across the
area on Thursday and Friday. Otherwise, a cold front will pull
through Thursday night shifting our temperatures back towards the
colder side as we head towards the weekend.
&&
.AVIATION /00Z TAFS THROUGH 00Z TUESDAY/...
Issued at 553 PM CST Sun Dec 3 2023
IFR-LIFR stratus and/or fog persists across much of the forecast
area to start this period, especially along and east of the
James River Valley. With loss of heating/mixing in the stratus-free
areas farther west, have seen rapid development of fog near/west
of the James River Valley. This could lead to a period of VLIFR
visibility at KHON this evening, and overall low confidence in
expected trends at KHON until westerly winds become more
prevalent and increase later tonight/early Monday.
Farther east, have shifted to a more pessimistic outlook for
much of this TAF period, as 1recent RAP runs and HREF ensemble
show moderate to high probabilities of IFR stratus persisting
through at least daybreak Monday, with greater potential for
improvement by late morning as stronger mixing commences.
Locations west of the James River toward south central SD could
see increasing west-northwest winds after 04/18Z, with gusts in
excess of 30-35kt possible. These stronger wind gusts are not
expected to impact TAF locations within this TAF period.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...Dense Fog Advisory until 9 AM CST Monday for SDZ038>040-
053>055-059>061-065-068.
MN...None.
IA...None.
NE...None.
&&
$$
UPDATE...JH
DISCUSSION...Gumbs
AVIATION...JH
Area Forecast Discussion
National Weather Service Gray ME
737 PM EST Sun Dec 3 2023
.SYNOPSIS...
Low pressure will track through the eastern Great Lakes this
evening, spreading rain and snow across the region. Significant
snowfall is forecast across the foothills and points northward
with a rain/snow mix elsewhere. There remains potential for
impacts into the Monday morning commute due to wintry
conditions. Accumulating snow tapers off Monday evening with
snow showers lingering through Monday night. A drying trend
follows into mid week.
&&
.NEAR TERM /THROUGH TONIGHT/...
730PM Update...No changes to the overall forecast with this
update. Just a couple of minor edits to temps and dewpoints
over the next couple of hours based on trends.
Previous...
A winter storm is underway this afternoon as low pressure
tracks north of the Ohio Valley this evening. This low is
forecast to track through Lake Ontario, before becoming a
inverted trough with low pressure consolidating outside of the
Gulf of Maine through Monday. Not much has changed from this
morning`s package.
For tonight, precipitation will continue. Precip types have
favored snow once precip rates increase. This makes sense given
the cool 925mb temps and surface temps just a few degrees above
freezing for much of the area. Temps in the mid to lower 30s are
expected to fall to around freezing for much of the area
tonight, and this will promote the bulk of the area flipping to
all snow. Points that may see more in the way of rain will be
the immediate Maine coast down to SE NH. Here the coastal front
may stay just a tad inland, particularly through the NH Seacoast
to keep precip mainly rain.
A few miles in from the coast, snow may fall for much of the
event. However, ratios and the ability for the snow to
accumulate may be hampered by the moderate temps. Moving inland
to into interior areas, this is where snow accum will pick up,
and be a heavy/wet consistency. Up to 4 to 6 inches will be
possible here, making it a potentially stressful cleanup come
Monday morning.
The greatest amounts will be found in the foothills and
mountains, where all snow is anticipated, and closer to climo
norm snow ratios are forecast. Local vis is already reduced to a
half or quarter miles in spots thanks to the strengthening low,
terrain convergence, and a saturated DGZ. Portions of this area
may well see a foot of snow, perhaps more through the day Monday
at higher elevation.
Into early Monday morning, guidance is showing what appears to
be a deformation axis or comma head of precip settling across
northern New Hampshire through western ME and towards the ME
Capitol Region. Timing would fall close to the beginning of the
morning commute, and patience/care cannot be stressed enough.
Snow rates may be the greatest during this period, perhaps
around 1 in per hour. This will also reduce visibility.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
The bulk of accumulating snow will be exiting the area by 10am
Mon morning. With the loss of upper level moisture and cloud
ice, drizzle or flurries may be left behind through early
afternoon. This will first be noticeable across southern NH,
and pulling through Portland area and central Maine through
noon.
With the low transitioning to an inverted trough across the
area, there will be remaining low level moisture and minor
forcing factors. In general, the deepest moisture remains across
northern NH and western ME through the day, prolonging snow, and
adding additional light accums. Elsewhere will depend on pockets
of lift to generate measurable precip outside snizzle or
drizzle. This lift may increase come Monday evening, providing
another shot of widespread light snow for the region overnight.
There is some uncertainty of enhancement along coastal front
features such as the NAMnest and HRRR suggest. Little confidence
is there to pinpoint this QPF at this time, but can`t rule out
some lingering accums overnight.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
Little change to the going forecast as currently focusing on
current storm. Deterministic and ensemble output hasn`t changed
much for the Tue-Weekend period. Some members indicate that
inverted trough may hang around into Wednesday with some light
snow for southeast zones. Will have to continue to watch trends
in this mostly mesoscale feature. Otherwise, warm front moves
toward the region Fri-Sat. Some indications that a significant
low pressure system affects the region Sun-Mon but we are a long
way out. But we`ll continue to monitor trends.
&&
.AVIATION /01Z MONDAY THROUGH FRIDAY/...
Short Term...Most terminals will remain IFR tonight through
Monday. Periods of LIFR will be possible combined with low vis,
especially in regions of SN across central and northern NH, and
much of interior Maine. Winds will slowly drift E to N through
Monday and monday night. Light snow continues with some drizzle
Monday.
Long Term...Lingering low cigs and SHSN will bring potential for MVFR
and at times IFR Tue morning. Conditions improve as Tuesday
progresses while there may be some lingering MVFR cigs. Mainly
VFR will prevail Wednesday into Thursday except perhaps a period
of MVFR across southernmost ME and southeastern NH depending on
where trough sets up.
&&
.MARINE...
Short Term...Winds will peak around 30kt this evening and
overnight as low pressure nears the coast. These will decrease
Monday afternoon to around 15 kt, becoming 20 kt from the north
Mon night.
Long Term...Low chance of SCA conditions Wed-Wed night,
otherwise relatively tranquil on the waters Tue-Fri.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...Winter Storm Warning until 1 PM EST Monday for MEZ007>009-
012>014-020>022.
Winter Weather Advisory until 10 AM EST Monday for MEZ018-019-
033.
Winter Weather Advisory until 1 PM EST Monday for MEZ025>028.
NH...Winter Storm Warning until 1 PM EST Monday for NHZ001-002-004.
Winter Weather Advisory until 10 AM EST Monday for NHZ003-
005>010.
MARINE...Small Craft Advisory until 1 PM EST Monday for ANZ150-152-154.
Small Craft Advisory until 4 AM EST Monday for ANZ151-153.
&&
$$
NEAR TERM...Combs/Cornwell
SHORT TERM...Cornwell
LONG TERM...Ekster
Area Forecast Discussion...Updated
National Weather Service Lincoln IL
923 PM CST Sun Dec 3 2023
.UPDATE...
Issued at 923 PM CST Sun Dec 3 2023
A complex scenario unfolding for tonight`s forecast in southern
portions of central IL and southeast IL regarding the evolution of
a compact low pressure system currently near Kansas City.
Precipitation with this low has been increasing the past few
hours, consistent with high resolution model forecasts which track
the low east to ESE along the I-70 corridor overnight, and the
I-64 corridor east from St Louis. Banded precipitation structures
associated with frontogenesis could produce some healthy
precipitation amounts reaching as high as the half to one inch
range just south of the central IL forecast area. The heavier
precipitation amounts could also change precipitation type to snow
given the expected temperatures just a few degrees above freezing,
resulting in potential for a quick inch or locally more. On the
other hand, the marginal temperatures could result in a mix of
rain and snow, and very little to no accumulation. With all that
said, it is possible very little or no precipitation will actually
reach as far north as the central IL forecast area, and the most
likely counties to get clipped with decent rain/snow are Scott,
Christian, Shelby, Effingham, Jasper, Crawford, Clay, Richland,
and Lawrence Counties. Have changed precipitation amounts just a
touch in portions of these counties to bring totals of a tenth to
a quarter inch, but kept snow accumulations zero due to likelihood
of only a mix of rain and snow. Otherwise, expect lows to range
from 31 to 35 across the area, with light winds becoming northeast
as the low passes by to the south toward morning.
37
&&
.SHORT TERM... (Tonight through Monday)
Issued at 313 PM CST Sun Dec 3 2023
Short-wave trough evident on 20z/2pm water vapor imagery over
Nebraska/Kansas will track eastward tonight, bringing a period of
light rain and snow to parts of central Illinois. Latest CAMs
have trended slightly further south with the track of the 500mb
vort max. As a result, have removed PoPs for locations along/north
of I-74 for late tonight into Monday morning. Have focused high
chance to likely PoPs along/south of a Jacksonville...to
Effingham...to Robinson line. Precipitation type remains in
question as NAM forecast soundings show a 2-3C warm layer aloft
which would at least partially melt any falling ice
crystals...while the RAP suggests ice crystals may be entirely
absent within the profile. Given the strength of the approaching
wave, think the deeper moisture layer shown by the NAM is more
reasonable. As a result, am anticipating a mix of light rain and
snow across the southern half of the KILX CWA. If sufficient
dynamic cooling occurs within any precip bands that develop, the
potential exists for a couple tenths of an inch of snow on grassy
surfaces. However am not anticipating any travel impacts for the
morning commute as surface temps remain above freezing where
precip is occurring. Once the system departs, a return to cool/dry
weather is expected by Monday afternoon with high temperatures
topping out in the lower to middle 40s.
Barnes
.LONG TERM... (Tuesday through Next Sunday)
Issued at 313 PM CST Sun Dec 3 2023
The next short-wave trough rapidly approaches from the northwest
by Monday night, spreading a mix of light rain and snow across
mainly the northern half of the CWA. This system will be deprived
of deep-layer moisture, so QPF will generally be less than one
tenth of an inch. Once the wave passes, dry weather will return
for Wednesday and Thursday. As has been advertised by the past
several model runs, upper troughing over the western CONUS will
result in downstream ridging across the Midwest/Ohio River Valley
by the end of the week. This will push temperatures above normal
for Thursday and Friday...with highs climbing well into the 50s
and perhaps exceeding 60 degrees in a few spots. The next
significant chance for precip will hold off until Saturday when
the western trough begins to shift eastward.
Barnes
&&
.AVIATION... (For the 00z TAFs through 00z Monday Evening)
Issued at 550 PM CST Sun Dec 3 2023
Cigs around 2500 ft are in place across central IL, but should
quickly depart from KSPI and KDEC as a weather system approaches
from the west and partial clearing ahead of the system surges
northward into these areas. With an expanse of MVFR cigs to the
north and diurnal trends favoring lower cigs, any improvement at
KPIA-KBMI-KCMI is more doubtful, however chances appear good
enough at KCMI that VFR cigs have been forecast from 06Z-14Z. The
weather system to the west should only affect KSPI and possibly
KDEC with -ra/-sn after 07Z until around 14Z. Winds SW around 5
kts or less, becoming light and variable, then NE 5-10 kts by
14Z.
37
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
Area Forecast Discussion
National Weather Service Jackson KY
1100 PM EST Sun Dec 3 2023
.UPDATE...
Issued at 1100 PM EST Sun Dec 3 2023
The forecast is on track so just a quick update to the grids
mainly to fine tune the Sky/T/Td grids per the latest obs and
trends. These tweaks have been sent the NDFD and web servers
along with a freshening of the zones and SAFs.
UPDATE Issued at 905 PM EST Sun Dec 3 2023
01Z sfc analysis shows eastern Kentucky between weather systems
as weak high pressure moving through the area has been enough to
slacken the winds and clear the skies. This is also setting up
radiational cooling for much of the JKL CWA. As such,
temperatures now vary from the mid 30s in the valleys to the
upper 40s on some of the ridges. Meanwhile, dewpoints are
running in the mid 30s. This ground level moisture combined
with light winds and mostly clear skies should cause some
valley fog to develop and perhaps become locally dense before
lower clouds move into the area later tonight. Have updated the
forecast mainly to adjust sky cover, lows, and add fog through
the night. Did also include the latest obs and trends for the
T/Td grids in the near term. These adjustments have been sent to
the NDFD and web servers along with a freshening of the zones
and SAFs.
&&
.SHORT TERM...(This evening through Monday night)
Issued at 311 PM EST SUN DEC 3 2023
Key Messages:
* Cooling pattern sets in as the first of a series of fast moving
disturbances aloft move through the region.
* Cooler than normal temperatures for Monday.
* Rain showers move in early Monday morning and spread across the
area through out the day. Rain ends early Monday evening.
* A few flakes of snow possible on highest ridges along the VA
border Monday evening.
* Another system brings rain showers to the area early Tuesday
morning.
Analysis and Discussion
Several models have a couple of clipper type systems bringing
increasing clouds and at least scattered rain showers to eastern
Kentucky to begin the new work week. As for today and tonight, we
should see steadily decreasing cloud cover through the late
evening. Late tonight, clouds will be on the increase yet again,
as the first clipper system moves through the area. The NAM,
NAMNEST, HRRR, and RAP models all have precip moving through on
Monday. A couple of the models were less robust than the others
and had less precip. Preferred the more detailed HRRR and NAMNEST
solutions since we already have cool air and plenty of moisture
in place and incoming over the next couple of days. Also preferred
blend of CONSMOS and CONSRAW for temperatures tonight through
Monday night, with some adjustments made to account for incoming
cloud cover and precip.
As far as areas of concern, there really aren`t any at this time
in the short term. General cloudiness and a couple of rounds of
precip are expected, with light winds. In summary, much needed
rain continues to be in the forecast going into the first of the
upcoming work week.
.LONG TERM...(Tuesday through Sunday)
Issued at 318 PM EST SUN DEC 3 2023
Key messages:
* A weather system will likely bring showers to at least a portion
of the area in the Tuesday to Wednesday morning time frame,
probably changing to flurries or light snow for most areas
before ending.
* Dry weather is forecast from late Wednesday through Friday.
* Another storm system, possibly a strong one, will bring a
potential for rain as we move into the weekend.
A mid/upper level shortwave trough and its coinciding surface low
will move southeast across the Midwest Monday night and Tuesday,
reaching the Ohio Valley by Tuesday evening. Warm air advection
along with support from the upper level system could bring us
showers Tuesday evening into the overnight, with the greatest
probability (chance category) in our northern counties. The system`s
cold front will pass on Tuesday night. Our best shot at precip will
be post frontal passage from shallow convection in the cold air
advection and upslope flow coinciding with the arrive of the upper
trough. As the atmosphere cools, present indications are that it
will get cold enough for a mix of rain and snow, or a changeover
from rain to snow, but not cold enough for any accumulation except
for perhaps an inch or two on the highest peaks near/along the
Virginia border.
Any remaining precip will taper off on Wednesday as the upper trough
departs eastward and surface high pressure builds in from the west,
easing cold air advection and bringing drier air. The surface high
or ridge will pass over on Wednesday night and bring our coldest
temperatures of the week. It then slips to our southeast late in the
week and warm air advection returns as transient ridging aloft
passes over from west to east, continuing dry weather through Friday.
The next mid/upper level trough will amplify as it moves east across
the CONUS late in the week. Both the GFS and ECMWF show it
developing a potent negative tilt as it arrives, supporting
development of a deep surface low. There are still differences in
timing and track at that long range, with quite a bit of forecast
uncertainty as a result. Have held the PoPs to chance category on
Saturday, with likely (60 to 70 percent) PoPs Saturday night into
Sunday.
Deviations from the NBM were made for Tuesday night and especially
for Wednesday, with the 5th percentile used for high temperatures
Wednesday given GFS and ECMWF 1000-850 hPa partial thicknesses
crashing below the critical 1300-meter threshold Wednesday morning
in cold advection regime with clouds and some precipitation.
However, it should be noted that the model trend is a bit slower
than previous runs in lowering thicknesses below the critical
threshold to support a changeover to snow across the area. The NBM
Deterministic forecast high was already just below 25th percentile
of the NBM probabilistic envelope, yielding increased confidence in
lowering high temperatures. QPF was also raised Wednesday toward the
90th percentile but overall this resulted in modest snow
accumulation changes, and at that only along the Virginia border
area.
&&
.AVIATION /00Z TAFS THROUGH 00Z TUESDAY/...
Issued at 725 PM EST Sun Dec 3 2023
VFR conditions overspread eastern Kentucky late this past
afternoon and will hold for much of the aviation forecast
period. Another approaching low pressure system does bring in
more clouds and a potential for some MVFR CIGs for Monday
morning along with scattered showers. Southwest to west winds
will continue to settle this evening decreasing to light and
variable by midnight. Look for them to pick up again from the
west at near 10 kts by midday, Monday.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
UPDATE...GREIF
SHORT TERM...AR
LONG TERM...CMC
AVIATION...AR/GREIF
Area Forecast Discussion
National Weather Service Melbourne FL
1011 PM EST Sun Dec 3 2023
...New UPDATE, MARINE, AVIATION, PREV DISCUSSION...
.UPDATE...
Issued at 918 PM EST Sun Dec 3 2023
KMLB radar imagery shows isolated showers over the local Atlatic
waters. This is well ahead of a cold front across the eastern
CONUS and northern Florida which will cross the Penisula Monday.
Current temperatures are in the upper 60s to low 70s with partly
to mostly cloudy skies. Isolated showers are forecast overnight
and into Monday morning over the local Atlantic waters, as well as
north of I-4. Patchy dense fog is also forecast within a few hours
leading up to sunrise and shortly after. Visibilities will have
the potential to drop to below one mile in spots, especially
across portions of Okeechobee, Osceola, Orange and Lake counties.
If you encounter patchy dense fog while driving, slow down, use
your low beam headlights, and leave plenty of distance ahead of
you. Any fog that develops should burn off by around 9am. Expect
overnight lows in the mid 60s to low 70s.
&&
.MARINE...
Issued at 918 PM EST Sun Dec 3 2023
Current-Monday... A cold front will cross the local waters Monday
afternoon. Isolated showers are forecast through Monday afternoon.
West-southwest winds around 8-14kts will build seas to 1-2ft with
up to 3-4 ft in the offshore waters (20-60nm).
Tuesday-Thursday... (Modified Previous Discussion) The
aforementioned cold front will stall across South Florida`s waters
and the Keys early Tuesday before diminishing. Behind the front,
conditions dry out as an area of high pressure builds across the
southeastern US. Expect northwest winds on Tuesday, with speeds
generally between 10 to 15 knots. On Wednesday, a reinforcing
frontal boundary will push southward across the Florida peninsula
and local Atlantic waters, resulting in the northwesterly winds
increasing to 15 to 25 knots across the local Atlantic waters. Winds
will veer to out of the northeast on Thursday and decrease back to
10 to 15 knots. Seas 2 to 4 feet on Tuesday, increasing to 4 to 8
feet on Wednesday due to the winds, and then decreasing slightly to
3 to 7 feet on Thursday.
&&
.AVIATION...
(00Z TAFS)
Issued at 918 PM EST Sun Dec 3 2023
TAFs start off VFR. IFR CIGs are forecast overnight into Monday
morning at KDAB, KLEE, KMCO, KSFB, and KLEE. Patchy fog is also
possible, especially across the interior. Cloud cover will
gradually decrease into the afternoon behind a cold front that
will cross the Penisula Monday. Expect west to southwest winds at
5-10kts.
&&
.PREV DISCUSSION...
Issued at 918 PM EST Sun Dec 3 2023
Tonight/Mon...The cold front remains well to the west near TLH
late this aftn but there is a pre-frontal trough or outflow
boundary pushing into northern sections sparking scattered showers
and isolated storms and a temporary wind shift out of the W/NW.
This activity will continue to push E/SE into this evening into
Osceola and Brevard counties and offshore. A brief downpour and
gusty wind up to 40 mph is possible with the stronger cells. The
front will slide into central FL overnight and early Monday and
bring isolated showers. The HRRR shows stratus and fog expanding
from the FL Gulf coast reaching southern and interior sections
late tonight. The low clouds could linger much of Monday morning
and even when they diminish, considerable mid and high clouds will
keep skies mostly cloudy. Not a lot of cooling immediately behind
this front. Max temps will range from the upper 70s Lake and
Volusia to the lower 80s south with a few mid 80s possible.
Tuesday... (Modified Previous Discussion) The aforementioned cold
front is progged to stall across South Florida and the Keys early
Tuesday before diminishing, with the Euro showing a faster decay
of the boundary than the GFS. At the surface, a high pressure
system over the central US will gradually strength and shift
eastward across the southeastern US behind the front. Locally,
northerly winds will help filter in the drier, cooler airmass into
east central Florida. Thus, rain chances will be less than 10
percent with lower relative humidities as well.
Afternoon highs on Tuesday will fall closer to climatological normal
for this time of year, with temperatures in the low to mid 70s
across east central Florida. Overnight lows on Tuesday in the upper
40s to low 50s.
Wednesday-Saturday... (Modified Previous Discussion) Dry conditions
are forecast across east central Florida through the remainder of
the period. A mid-level trough will sweep across the southeastern US
on Wednesday, pushing a reinforcing frontal boundary across the
peninsula at the surface, with even drier and cooler air forecast to
push in behind the front. As a result, clearing skies are forecast
across the area Wednesday through Wednesday night. As the surface
high shifts eastward towards the Atlantic, onshore flow will return
Thursday into Friday, leading to some increasing moisture across the
area and therefore increasing cloud coverage.
Coolest temperatures are forecast on Wednesday as a result of the
reinforcing boundary, with afternoon highs in the low 60s to low 70s
and overnight lows in the low 40s to mid 50s. Temperatures will then
gradually warm through the remainder of the week into the weekend,
with afternoon highs in the mid 60s to mid 70s on Thursday and in
the low 70s to low 80s Friday and Saturday. Overnight lows in the
mid 40s to upper 50s on Thursday and in the low 50s to mid 60s
Friday and Saturday nights.
&&
.HYDROLOGY...
Issued at 231 PM EST Sun Dec 3 2023
The Saint Johns River at Astor is forecast to continue a very
slow decline this week. The river is forecast to remain within
Minor Flood Stage through mid week, but could fall into Action
Stage later in the week.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 66 79 54 71 / 20 20 0 0
MCO 69 80 57 72 / 10 20 0 0
MLB 68 82 58 75 / 10 20 0 0
VRB 67 83 58 76 / 20 20 0 0
LEE 67 78 54 70 / 20 20 0 0
SFB 68 80 55 72 / 10 20 0 0
ORL 70 81 57 73 / 10 20 0 0
FPR 67 83 58 77 / 10 20 0 0
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...None.
AM...None.
&&
$$
Fehling/Sedlock
Area Forecast Discussion
National Weather Service Topeka KS
222 PM CST Sun Dec 3 2023
.DISCUSSION...
Issued at 220 PM CST Sun Dec 3 2023
Key Messages
- Progressive upper level wave develops light rain showers, perhaps
mixed in with light snow through early evening across far northern
Kansas.
- Clouds clear out tomorrow, commencing drier conditions and warmer
temps peaking in the 60s Wednesday and Thursday.
- Low confidence in next weekend`s system that may bring rain
chances and cooler temperatures once again to the region.
Shortwave trough axis is noted on water vapor imagery this afternoon
sliding across Nebraska into northern Kansas. The sfc low is
currently situated along the KS/NE border while the frontal boundary
bisects Kansas. Ahead of the boundary in northeast Kansas, mid to
high level clouds blanket the area as southerly winds pickup to near
10 mph. High temps have been able to climb into the upper 40s for
most areas, with the exception of north central Kansas in the low
40s. A wide swath of radar returns shifting over MHK and MYZ at the
current hour have not been observed reaching the sfc as cloud bases
remain near 10kft. Higher returns and lower cloud cover near the
KS/NE border are however reaching the sfc in the form of rain
showers with moderate confidence in light rain showers occurring
over northern Kansas through early evening as the sfc low crosses
through the CWA. As temperatures cool close to the freezing mark, a
few showers could mix or transition to light snow. Sounding profiles
are saturated for a brief time before drier air dissipates any
precip so overall qpf amounts would be a few hundredths at best. As
the sfc low passes by, winds on the back side veer to the west and
northwest becoming gusty this evening at 15 to 20 mph sustained.
Skies become sunny Monday morning as temperatures begin their
warmup, starting with the low and middle 50s Monday afternoon.
Increasing mid clouds skirt northern portions of the CWA in the
evening as another upper trough bypasses the area to the north. Mid
level height rises commence Tuesday onward, returning dry conditions
and mostly sunny skies each afternoon. Highs peak on Thursday in the
middle 60s before the next cold front approaches to the northwest on
Friday. Latest cluster analysis of ensemble data suggest large
disparities in an upper trough axis that drops southeast over the
central plains next weekend. 12Z operational GFS/EC signal higher
qpf totals focusing along the cold front to our southeast so overall
confidence remains low in precipitation chances for the CWA.
&&
.AVIATION...(For the 18Z TAFS through 18Z Monday afternoon)
Issued at 1136 AM CST Sun Dec 3 2023
VFR conditions at terminals as mid clouds dominate the afternoon.
Fropa timing has pushed a few hours, progged to arrive near 00Z
at KMHK and 02Z at KTOP/KFOE as winds veer to the west at 10 to
15 kts. Added VCSH at KMHK where confidence is higher for
scattered showers to develop, but may dissipate before impacting
KTOP/KFOE. Low stratus accompanies the boundary, however most
short term soundings are trending towards a faster clearing of
MVFR stratus btwn 06-09Z. The HRRR is also attempting to develop
low visbys on the back edge of the stratus so will need to watch
for that potential as well Monday morning.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
DISCUSSION...22
AVIATION...22