Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 12/06/22
AREA FORECAST DISCUSSION
National Weather Service Albany NY
916 PM EST Mon Dec 5 2022
.SYNOPSIS...
Clouds will thicken and lower overnight ahead of
a warm front. The warm front will bring periods of mainly rain
tomorrow morning through the afternoon with above normal
temperatures into the mid week. The unsettled weather continues on
Wednesday ahead of a cold front before cooler more seasonable
temperatures return late in the week.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
Zone of clear sky from the eastern Catskills through the mid
Hudson Valley and near the Capital Region to the Berkshires and
NW CT is shifting east as more widespread high clouds are
spilling east to cover the entire region. The entire region will
be cloudy by midnight, but just high and thin clouds as the
deeper cloud cover spreads over our region more toward
daybreak.
The high clouds should limit the radiational cooling in areas
that have calm winds but until the clouds do spread,
temperatures will drop a degree or two before holding steady
between midnight and daybreak. Some temperatures have fallen
below the forecast, so some adjustments to temperatures and sky
cover through daybreak were made.
Steady south winds in many areas but some protected areas are
calm to near calm. There will be big differences in
temperatures in small distances depending on where it is calm
and where the steady south winds persist, also the clearing
versus the thicker cloud cover.
PREVIOUS DISCUSSION:
High pressure /1035 hPa/ continues to shift east/northeast of
Nova Scotia late this afternoon into tonight. The mid and upper
level flow continues to shift southwesterly ahead of the
northern stream trough over the northern Plains and central
Canada. The southern stream remains over the southern Plains and
Southeast. Split mid and upper level flow dominates across the
CONUS currently, and once again it looks like the forecast area
will get into a warm sector tomorrow ahead of the next cold
front with above normal temps.
Cirrus clouds continue to increase in the warm advection
pattern. Some thinning in the clouds is likely early tonight
with some decoupling. Sfc dewpoints remain in the teens and 20s
in the dry low-level air mass. Temps may drop off prior to
midnight into the 20s to lower 30s, but then steady or slightly
rise in the early morning hours. In the initial surge of warm
advection it will take some time for the column to saturate with
the dry low-level air mass. Clouds will thicken and lower with
some lower stratus possible along and east of the western New
England higher terrain. Some could reach locations south and
east of the Capital Region prior to daybreak.
Most of the guidance including some of the CAMs such as the
3-km HRRR have very little pcpn prior to daybreak. The one
exception is with the return low-level southeasterly flow from
the low onshore may allow for some spotty light snow mixed with
rain depending on how warm the sfc layer gets across the eastern
slopes of the southern Greens and Adirondacks. We have some
slight to low chance PoPs in these areas in the early to mid
morning hours.
Lows tonight will range from the upper 20s to lower 30s over the
higher terrain and sheltered valleys with lower to mid 30s in
the valley areas. Again, temps may steady or slightly rise with
the south/southeast breeze picking up.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/...
Tomorrow...A warm front approaches from the south and west in
the morning with the southwesterly low-level jet at 850 hPa
increasing to 35-45 kts. The moisture advection increases with
PWATs increasing to 1 to 2 STDEVs above normal based on the
latest NAEFS. Some shadowing is possible again in the Greater
Capital Region, portions of the eastern Catskills and Schoharie
Valley. The best isentropic lift on the 285/290K surfaces
occurs in the mid to late afternoon. We continued to increase
PoPs to categorical values across the entire region by then. We
should see a gradual increase from the southwest to northeast
during the late morning into the afternoon. A light wet
snow/sleet to rain transition may occur in the west/southwest
Adirondacks before transitioning to all rain. Any accumulation
would be light amounting to a light coating to a couple tenths.
In the low-level warm advection pattern, we increased temps
closer to the ECM MOS and NBM with highs in the upper 40s to
lower 40s in the valleys areas or below 1500 feet in elevation.
We went with upper 30s to mid 40s over the higher terrain above
1500 feet. A south to southeast breeze will increase 10-15 mph
or so and pick up overnight.
Tue night...A very mild December night is expected with periods
of light rain continuing, as the warm front lifts north and
east of the region. A lull in the precipitation is possible
overnight, as the warm front and associated weak short-wave move
across the region. The southeast to south winds may increase to
10-20 mph with some gusts 25-35 mph along the western New
England higher terrain and confluent area of the Capital Region.
PWATs increase to +2 to +3 STDEVs above normal. H850 temps rise
+1 to +2 STDEVs above normal based on the NAEFS. The lowest
temps may occur in the early evening, as temps may steady or
slightly rise overnight. Lows will be in the mid 40s to around
50F in many valley locations, and upper 30s to lower/mid 40s in
the higher terrain. Min temps will likely be 15-20 degrees above
normal. Some patchy fog may form in a few spots. Total rainfall
prior to daybreak Wed will range from a third of an inch to
three quarters of an inch in the valley areas with the favored
southwest flow orographic enhancement areas of the southwest
Adirondacks, southeast Catskills, and southern Greens ranging
from 0.75" to 1.50" with some locally higher amounts. Some hydro
issues are expected with only within bank rises.
Wednesday...The cold front to the system moves across the region
during the late afternoon with continued showers. The synoptic
forcing does not look particularly strong. The latest ECMWF has
a weak wave form along the front moving across PA and southern
NY. The latest NAM has some pockets of elevated instability
with Showalter stability indices of 0 to -2C. A rumble of
thunder is possible, but lack of appreciable CAPE and heating
will be an issue with lots of clouds that should inhibit any
strong thunderstorms at this time. SPC has general thunder
across most of the region. Max temps were favored close to the
ECM MOS and NBM with highs well above normal in the mid 40s to
around 50F over the higher terrain and lower to mid 50s in the
valleys with spotty upper 50s possible in the mid Hudson
Vally/NW CT. Additional rainfall will be fairly light with two
tenths of an inch to a third of an inch (unless convection
forms).
Wednesday Night...Cold advection occurs in the wake of the
front and possible wave moving east of Cape Cod. Some
west/northwest flow upslope rain showers and perhaps a rain/snow
shower mix occurs for the western Adirondacks, southern Green
and northern Taconics. Little or no snow accumulation is
expected overnight with perhaps a coating in a few spots. Lows
fall into the upper 20s to lower/mid 30s north and west of the
Capital Region, and expect upper 30s to lower 40s to the south
and east.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
Upper system exits through eastern Canada Thursday and as upper
confluence increases over eastern Canada, strengthening low level
ridging will build south out of Canada. Cold advection will be weak
at first, but then, by Thursday night and Friday the colder air will
build into our region. Highs Thursday with increasing sunshine in
the 40s to lower 50s with around 40 higher terrain.
Friday through Monday, there are major disagreements in the overall
upper pattern in sources of guidance/ensembles. Some sets of
guidance/ensembles suggest a complex evolution of an upper system
and low level forcing contributing to chances of rain and snow
showers Friday into the weekend. Other sets of guidance/ensembles
show a weakening upper impulse tracking well south of our region
while flat northern stream upper ridging continues over our region
through much of the weekend with little to no precipitation.
The mean of the ensembles suggest more clouds than sun and just
slight chances for rain and snow showers with the snow showers
mainly at night Friday night. Sunday could be mainly dry but again
more clouds than sun as a potentially more organized upper impulse
or developing closed low could begin an approach to our region later
Sunday into Monday. By Monday afternoon, there could be some chances
for isolated rain and snow showers.
Highs Friday around 40 to mid 40s with mid 30s to around 40 higher
terrain. Highs Saturday in the upper 30s to lower 40s with lower to
mid 30s higher terrain. Highs Sunday and Monday in the upper 30s to
lower 40s with mid 30s higher terrain.
&&
.AVIATION /02Z TUESDAY THROUGH SATURDAY/...
Through 00Z Wed...High clouds will thicken and lower through the
night as moisture steadily increases. There is potential for a lower
cloud deck (MVFR/IFR) to advect into the region off the ocean as
southeasterly winds increase. Went with a SCT mention at KPOU/KPSF
later tonight to hint at this potential. Otherwise, dry air at
midlevels will delay top-down moistening such that any vsby
restrictions due to rain hold off until after 18Z. MVFR cigs may
develop a few hours earlier, however. Expect conditions to
deteriorate to borderline MVFR/IFR with both cigs and vsby from 18Z
to the end of the TAF period as showers become more widespread.
Winds will be light and variable overnight, except south-
southeasterly at 5 to 10 kt at KALB. Winds will be mainly out of the
south to southeast on Tuesday at 5 to 10 kt. Borderline low-level
wind shear conditions will develop after 06Z at KGFL and after 12Z
at KPOU/KPSF. LLWS was omitted from KALB due to the expectation of
slightly stronger surface winds.
Outlook...
Tuesday Night: High Operational Impact. Breezy. Definite RA.
Wednesday: High Operational Impact. Definite SHRA...RA.
Wednesday Night: Low Operational Impact. Slight Chance of SHRA.
Thursday: No Operational Impact. NO SIG WX.
Thursday Night: No Operational Impact. NO SIG WX.
Friday: No Operational Impact. NO SIG WX.
Friday Night: Low Operational Impact. Slight Chance of SHSN.
Saturday: Low Operational Impact. Slight Chance of SHRA...SHSN.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
MA...None.
VT...None.
&&
$$
SYNOPSIS...Wasula
NEAR TERM...NAS/Wasula
SHORT TERM...Wasula
LONG TERM...NAS
AVIATION...Thompson
Area Forecast Discussion
National Weather Service Des Moines IA
932 PM CST Mon Dec 5 2022
.UPDATE...
Issued at 932 PM CST Mon Dec 5 2022
Another night, another southward shift in the precipitation area.
0z model data including the HRRR, NAM, and RAP (21z) have all
shown a 30 to maybe 60 mile southward shift in the chance of
precipitation. I emphasize `chance` as cross sections and
soundings continue to indicate a fairly dry sub-cloud layer, which
as earlier discussion noted would result in only light snow or
flurries. This may enter our west central counties between 3 and
6am before the focus of precipitation shifts closer to I-80 around
8 or 9am. With the shift southward, sprinkles/light rain cannot
be ruled out farther to the southeast in our forecast area. Any
snow accumulation will be a dusting at most. Comparing the
upcoming event to this morning`s event, this event does not have
the fgen band that helped to focus the wintry precipitation
corridor, but rather broad low level thermal lift. Further, last
night`s 0z HREF had a sub-county stripe of wintry precipitation
for this Monday morning. Tonight`s 0z HREF run has no (mean) QPF
over the state. Will continue to monitor trends and adjust the
forecast overnight as additional data becomes available.
&&
.DISCUSSION.../Tonight through Monday/
Issued at 217 PM CST Mon Dec 5 2022
Key messaging highlights:
* Light snow/flurries possible north Tue
* Appreciable precip anticipated Thu/Thu Night, with winter
travel impacts likely, but precip types still uncertain
* Seasonal temperatures continue
Our pattern will remain active through the period with token snow
chances initially tomorrow, a more significant system Thursday
into Thursday night, and then another potential system early next
week. At onset this afternoon, all the precipitation from earlier
today has ended but mid and high clouds continue to stream
through the MO Valley driven through the base of the polar trough
and Pacific stream. This will stay in place into tomorrow with a
weak upper wave ejecting out of the confluence of the two streams
from the northern Rockies and Midwest. Model trends have
diminished precip potential from 00z, but a few continue to
suggest a swath of light snow or flurries north. There isn`t a
whole lot to hang your hat on as a forcing mechanism other than
theta-e advection increasing across the persistent baroclinic
zone, but will keep at least a token mention in the forecast. A
system will track trough the base of the polar trough Wed, with
fairly deep thermodynamic and kinematic forcing, but limited lower
level moisture will keep any precip and impacts to our north.
Most of our attention should be turned toward the Thu/Thu night
system however, which will track through CA into early Wed before
ejecting through the central Plains. Deep, phased kinematic and
thermodynamic forcing will arrive through the day Thu blossoming
precipitation across central and southern Iowa later in the day.
There is medium to high confidence in this regard, but confidence
in how this plays out is much less with Iowa in the thermal
transition zone, both surface and aloft. The GFS/GEFS suite seems
to be the warmest solution, with mainly rain and only light snow
north, but much of the remainder guidance is on the cooler side
and more aggressive with at least several inches of snow farther
south. These solutions also include various degrees of separation
between the front/surface features, and dry slot aloft, so while
rain or snow seem to be the dominate precipitation types driven by
near surface wet bulbs, differences with the melting/warm layer
aloft and meridional dry slot placement also leave graupel or
freezing drizzle in play for brief periods. Some weak convection
can`t be ruled out along the northern fringe of where ever the
dry slot ends up either. Thus our initial messaging will be more
of the `heads up` variety with appreciable QPF rather than trying
to pin down any specifics.
The current forecast has precip ending Friday morning, although
if current trends hold it may extent through the morning commute
and beyond, with the start of the weekend looking dry. PoPs do
return late in the weekend into early next week however, with
wintry mix chances, but confidence is quite low at this point. How
the western CONUS trough evolves is still very much uncertain
with little model agreement and a wide range of solutions.
&&
.AVIATION.../For the 00Z TAFS through 00Z Tuesday evening/
Issued at 529 PM CST Mon Dec 5 2022
Mid and high level clouds will continue to pass over Iowa in the
wake of a cold front that has moved south of the state. Winds from
the north will become from the northeast and east by daybreak
Tuesday. While there is high confidence in VFR conditions through
the period, bases below FL100 will be possible several hours
either side of midday Tuesday.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Ansorge
DISCUSSION...Small
AVIATION...Ansorge
Area Forecast Discussion
National Weather Service Lincoln IL
740 PM CST Mon Dec 5 2022
.SYNOPSIS...
Issued at 740 PM CST Mon Dec 5 2022
A fair amount of clouds to prevail the rest of the week across
central and southeast Illinois, along with periodic chances of
rain. Areas of fog will likely develop overnight and lift
Tuesday morning, mainly impacting areas near and south of I-72,
and some of the fog may be locally dense. Light rain chances will
spread northeast over central and especially southeast Illinois
Tuesday afternoon into Tuesday evening, with dry weather expected
Wednesday. More widespread rains will occur Thursday into Friday
morning. Temperatures will be near or slightly above early
December normals, with highs in the 40s or 50s this week.
&&
.UPDATE...
Issued at 740 PM CST Mon Dec 5 2022
Low clouds starting to become more prevalent south of I-70 and
also scraping areas near I-74, with some light drizzle being
reported there. High-res models have been showing a band of light
rain or drizzle forming over northern Illinois later this evening
and mainly staying to our north, but close enough to warrant some
low PoP`s across the far northern CWA. Across the southeast CWA,
rain chances have been trimmed back some, but will keep a mention
of drizzle overnight as the lower clouds expand along with some
fog. Hit the fog a little harder in recent updates as CAM`s have
been persistent with this over the southern half of the forecast
area, and NBM 4.1 probabilities are around 25% chances of
visibility below a mile.
Some minor temperature updates have also been made, primarily
nudging them up a degree or two.
&&
.SHORT TERM...(This evening through Tuesday)
ISSUED AT 300 PM CST Mon Dec 5 2022
A weak southerly flow is gradually increasing low level moisture
into central and southeast IL this afternoon and stratus cloud
decks 1.5-3k ft cover much of the area. Though a large hole in
the low clouds is from Scott county sw into northeast MO where
temps warmed into the low to mid 50s. Temps over CWA were in the
low to mid 40s, mildest from Springfield sw. Radar mosaic is not
showing much over central/se IL at mid afternoon with light
showers and drizzle more over KY and moderate to heavier rains
from southern half of TN south. 21Z surface map shows 1002 mb low
pressure over the OK panhandle while a weak cold front was over se
parts of WI/IA into nw MO. Weakening southerly winds to veer NE
later this evening and overnight as low pressure moves into the
Ozarks by Tue morning. Strengthening inversion to trap more low
level moisture with CAMs showing more fog develop later this
evening and overnight from Lincoln southeast with locally dense
fog possible. Fog that develops to diminish during mid/late Tue
morning. Lows tonight range from around 30F nw of the IL river, to
the upper 30s to near 40F in southeast IL.
Weak low pressure to lift up into the lower Ohio river valley
early Tue evening and spread light rain chances northward into
central and especially southeast IL during Tue afternoon and
evening where around a tenth inch of rain expected. Isolated
thunderstorms should stay se of Lawrence county late Tue afternoon
into Tue evening closer to frontal boundary near the Ohio river.
Highs Tue in the mid to upper 40s in central IL, but range from
lower 40s by Galesburg to lower 50s south of I-70.
&&
.LONG TERM...(Tuesday night through Monday)
ISSUED AT 315 PM CST Mon Dec 5 2022
Weak lift to push east of central IL during overnight Tue night
with light rain chances diminishing. CAMs shows patchy fog just
south of CWA Tue night and for now keeping mention of fog out of
southeast counties though could be a little fog with low clouds
and light rain. Lows Tue night in the lower 30s nw of the IL river
and 40-45F in southeast IL.
Brief break rain chances during Wed and Wed evening with rain
chances focused along frontal boundary from OK/AR eastward into
KY/TN. Could be some breaks in the low clouds over northern CWA
Wed while central and especially southern parts stay more in the
low clouds on Wed. Highs Wed range from upper 40s northern CWA to
50-55F in southeast IL.
A stronger storm system to eject ne from OK Thu and near central
IL by noon Friday. Models have trended slower with this storm
system and brunt of rains to arrive Thu into Fri morning and
diminishing during Fri afternoon. Pops may need to be increased
for Friday with cutoff upper level lows tending to be slower to
move through as a 548 dm 500 mb low is along the northern IN/OH
border by 6 pm Fri with cyclonic flow still over central IL.
Rainfall amounts of a half to three quarter inch look likely over
area Thu into Fri morning while isolated thunderstorms have
shifted further southeast of CWA over KY and far se MO Thu
afternoon into Thu night. Also the rain/snow mix is along and
north of I-88 in northern IL and areas northward Thu afternoon
into Fri morning. Highs Thu similar to Wed with 45-50F northern
CWA and 50-55F southern CWA.
Weak upper level ridge moves over IL on Saturday with dry weather
expected Fri night into Saturday evening with highs around 40F
northern CWA and 40-45F southern CWA/se IL. Extended models differ
with how they handle wx system in an active wx pattern going into
early next week. Sunday does not look as wet with just 20% pops of
mainly light rain. A better chance of precipitation arriving next
Monday as another deep upper level trof digs over the Rockies and
likely ejecting another low pressure system ne from the
central/southern high plains toward the Midwest. Looks warm
enough for mainly rain chances with highs in the 40s next Monday.
CPC 6-10 Day outlook for Dec 11-15 has 55-65% chance of above
normal precipitation over central IL while 40-50% chance of above
normal temperatures.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 520 PM CST Mon Dec 5 2022
Widespread ceilings around 2000 feet early this evening, though
some higher ceilings above 3000 feet are likely to impact KPIA for
a time this evening. HRRR guidance suggests this higher surge
stopping before reaching KSPI/KBMI. After that, a large part of
central Illinois will see ceilings fall well below 1000 feet
overnight. High-res model guidance has been fairly steady with an
area of potentially dense fog over the southern half of Illinois
overnight into Tuesday morning, though at the moment looks to be
just south of the terminals. However, NBM probabilities of
visibility below a mile are around 25% at KSPI overnight and early
Tuesday morning, so something to keep an eye on through the
evening. While visibility reductions are likely to improve toward
mid morning or so, clouds will be slower to ascend, with ceilings
likely staying IFR or low MVFR through the end of the period.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Geelhart
SYNOPSIS...07/Geelhart
SHORT TERM...07
LONG TERM...07
AVIATION...Geelhart
Area Forecast Discussion
National Weather Service Jacksonville FL
852 PM EST Mon Dec 5 2022
...AREAS OF DENSE FOG TONIGHT...
.UPDATE...
Issued at 852 PM EST Mon Dec 5 2022
A diffuse frontal is across the area and so difficult to place
but appears to be near or just south of Flagler county and then
oriented west to northwest into the FL panhandle and into
southwest GA. This front will slowly work northward through
Tuesday. The JAX 00Z sounding, HREF, and HRRR all suggest
radiation fog formation tonight but the extent of it is a bit
unclear. At this time, the chances of a widespread dense fog event
seem a bit lower than last night. Nonetheless, the best chances
look to be over our western zones and perhaps a relatively small
area from JAX northward along the I-95 corridor and toward U.S.
highway 1. We can`t rule out another dense fog advisory for parts
of the area, mainly inland areas from about Alachua county northward
into interior southeast GA. For the update, there was little change
to the areas of dense fog advertised. Patchy fog was included for
the evening hours in the Suwannee Valley area where Live Oak has
reported fog. The POPs on average are less than 15 percent but
there are a few sprinkles possible inland zones tonight. Min
temps again from upper 50s to 60, with lower 60s possible where
any mid level clouds hang around. For the marine forecast, little
change was needed in the CWF with generally light and variable
winds tonight and seas of 3-5 ft, with dominant period near 10
seconds.
&&
.NEAR TERM...
Issued at 251 PM EST Mon Dec 5 2022
A weak pressure pattern will be in place through tonight with a
broad low level ridge across FL, a weak warm front across south GA
and a coastal trough offshore of the local Atlantic coast. Diurnal
heating across NE FL enabled a weak west coast sea breeze to form
with a few very light spotty showers drifting inland across our
Suwannee River Valley zones. A few weak returns and enhanced
cumulus were also noted near the St. Johns River basin where some
light sprinkles will be possible through early evening. The best
shot of measurable rainfall will focus near the Altamaha River
basin through tonight north of the lifting warm front, but rain
chances will be less than 20%.
The main weather impact tonight (and the next several nights) will
be late night fog. There is plenty of low level moisture in place
across the area and as the boundary layer cools and decouples, fog
and low stratus will once again develop through sunrise Tuesday.
High resolution guidance indicated the highest probabilities of
dense fog (visibility < 1/4 SM) along and west of the I-10
corridor from JAX to Live Oak, and near I-75 from VAD to GNV.
Mild temps wild range above climo in mid 50s to low 60s.
&&
.SHORT TERM...
(Tuesday through Wednesday night)
Issued at 251 PM EST Mon Dec 5 2022
Warm days and foggy nights are expected as high pressure builds
over the area, both at the surface and aloft with an anonymously
strong 500 mb ridge of 590-592 dam amplifying across the GOMEX
this period. Temps will generally range 6-12 deg above climo
values with highs in the upper 70s to low 80s inland with sea
breezes keeping the coast slightly cooler in the mid 70s. Lows at
night will range in the upper 50s to low 60s.
&&
.LONG TERM...
(Thursday through next Monday)
Issued at 251 PM EST Mon Dec 5 2022
Overall a continued dry pattern and above normal temperatures. A
weakening front with meager moisture moves across the region late
Friday into Saturday mainly brining passing clouds and not much
rain chance (< 10% across SE GA). A slight cool down into Saturday
as the front begins to stall across the FL peninsula but temps will
still generally range above normal into early next week. The
latest ECMWF is much faster with the approach of the next frontal
system compared to the GFS Sun-Mon, with the official forecast
displaying the NBM composite with a low chance of showers Sun
night into Mon.
&&
.AVIATION...
(00Z TAFS)
Issued at 702 PM EST Mon Dec 5 2022
Currently, TAFs remain at VFR with areas of ceilings around 5 kft
with a few sprinkles possible. A diffuse warm front lifting
slowly north from northeast FL area and plenty of low level
moisture and boundary layer coupling/decoupling will allow areas
of fog and low ceilings to develop tonight. Generally kept the
current trend for inland TAFs going to LIFR and VLIFR after
midnight, but show MVFR to possible brief LIFR for the coastal
TAFs. Again, the highest chance of IFR or lower is expected to be
at GNV and VQQ. The low vsby and celling restrictions should lift
by about 14Z-15Z, with VFR ceilings returning. Again, some
patches of MVFR still possible 15Z-18Z. Sfc winds will be going
toward calm tonight, and then variable Tue 13Z-17Z, shifting to
the east for coastal TAFs in the aftn due to sea breeze.
&&
.MARINE...
Issued at 251 PM EST Mon Dec 5 2022
A weak warm front will lift northward across south Georgia tonight
with fog potential impacting inlets after midnight. Light and variable
winds are expected Tuesday through Thursday as high pressure builds
over the local waters. A cold front will approach the waters from
the north late Friday and moves south of the waters through Saturday
as high pressure builds north of the region. Seas may near advisory
levels with the front Friday into Saturday over the outer waters.
Rip Current Risk: Moderate rip current risk through Tuesday.
&&
.PRELIMINARY POINT TEMPS/POPS...
AMG 59 77 58 80 / 10 10 0 0
SSI 60 74 60 75 / 10 0 0 0
JAX 58 77 58 78 / 10 0 0 0
SGJ 60 74 60 75 / 0 0 0 0
GNV 58 79 58 81 / 10 0 0 0
OCF 60 80 59 81 / 10 0 0 0
&&
.JAX WATCHES/WARNINGS/ADVISORIES...
FL...None.
GA...None.
AM...None.
&&
$$
...UPDATED AVIATION FORECAST DISCUSSION...
.SYNOPSIS...
Issued at 324 PM CST Mon Dec 5 2022
Key Messages:
-Snow is possible Thursday and again next Monday. Although
distant in time, it`s worth noting the systems Thursday and
Monday are the result of the deep Hudson bay upper level low
retreating north toward the North Pole. This pattern shift
appears to be opening the door for Pacific storm systems to track
through or near the Central Plains.
&&
.SHORT TERM...(This evening through Tuesday night)
Issued at 324 PM CST Mon Dec 5 2022
Radar has been indicating midlevel frontogenesis across wrn and
ncntl Nebraska all day. The RAP model shows this feature getting
stronger tonight and is the basis for a chance of snow showers. The
latest POP forecast uses the blend of GFS, NAM, SREF and ECM but
shifts the POP about 20 miles south to line up with the
frontogenesis as indicated by radar and satellite. QPF is very
light, less than 0.05 inches, and this is likely the result of dry
air below 700mb.
The temperature forecast tonight leans on the short term model blend
plus bias correction. Widespread cloud cover tonight should hold up
radiational cooling and this forecast is warmer than the NBM 50th
percentile. The NBM 50th percentile was very close to the RAP model
for highs Tuesday. The RAP model is the basis for lows around 10
north to 20 south Tuesday night. A warm front should move east
tonight and Tuesday morning followed by a weak back door cold front
Tuesday afternoon. The front will drift into the Sandhills Tuesday
evening and lift slowly north after midnight.
.LONG TERM...(Wednesday through Monday)
Issued at 324 PM CST Mon Dec 5 2022
The models continue to converge on a system closing off across
the cntl Plains Thursday. The NAM, GFS and ECM are closing off an
h700mb low across nrn KS/Neb and this should be sufficient to
product light snow across parts of wrn and nctrl Neb. There has
been little change in the ECM QPF amounts and the GFS and ECM
ensemble means suggest 1 to 3 inches of snow also. Higher QPF
amounts are expected across ern Nebraska. The system is currently
along the nrn CA coast and predicted to move south through srn
CA/NV and then east northeast through WY and into Nebraska.
Another snow chance is in place next Monday. Once again, the ECM/ECM
ensemble are leading the way suggesting a disturbance off the coast
of Japan will move east and be in the Gulf of AK Friday. The system
will then move southeast through the nrn Rockies and close off
across ern Colo Monday. Although distant in time, it`s worth noting
the systems Thursday and Monday are the result of the deep Hudson
bay upper level low retreating north toward the North Pole. This
pattern shift appears to be opening the door for Pacific storm
systems to track through or near the Central Plains.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 525 PM CST Mon Dec 5 2022
VFR conditions are expected to primarily prevail through tomorrow
evening. The exception will be in scattered -SN overnight, where
localized MVFR visibility would be possible. The most likely area
for this to occur is across the southern Panhandle into the
central Sandhills. -SN exits the area through sunrise tomorrow
morning, with clearing skies expected after. Winds shift from
north to south overnight, then back to west and northwest by
tomorrow evening, generally below 15kts.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CDC
SHORT TERM...CDC
LONG TERM...CDC
AVIATION...Brown
Area Forecast Discussion...UPDATED
National Weather Service Morristown TN
926 PM EST Mon Dec 5 2022
...New UPDATE...
.UPDATE...
Issued at 919 PM EST Mon Dec 5 2022
The main changes to the forecast this evening will be to the
PoP/Wx grids, based on current radar and satellite trends.
Upstream across Middle TN, we are seeing much lighter and more
scattered precip, with much warmer cloud tops on IR imagery. So we
should see less precip coverge in most of the area after midnight.
The CAMS show some resurgence of showers developing over our area,
which is certainly possible, but the main QG forcing will have
exited to the east around 06Z. The forecast update will cut back
on PoPs, as well as remove the slight chance of thunderstorms
tonight and tomorrow morning. No lightning strikes have been
observed anywhere near East TN this evening, and with the exit of
the main QG forcing and warmer cloud tops, it is very unlikely to
occur.
&&
.SHORT TERM...
(This evening through Tuesday)
Issued at 312 PM EST Mon Dec 5 2022
Key Messages:
1: Rain showers will continue to move across the area tonight
through tomorrow, with a slight chance for a few rumbles of thunder.
2. Low probability of localized flooding across portions of the
southern TN valley and southwest NC. If flooding issues arises,
it will likely be across low lying and flood prone areas.
Discussion:
A good slug of precipitation is currently moving across the
southern TN valley and southwest NC this afternoon. The HRRR and
RAP both show this first wave of moderate precip slowly sliding
to our east later this evening. However, additional showers will
develop and spread in from southwest to northeast through the
night as isentropic lift persists ahead of a warm front to our
southwest. Additional QPF overnight ranges from 0.5 to 0.75 inches
across the southern TN valley and southwest NC, around 0.5 inches
across the central and northern TN valley, and 0.25 inches across
northeast TN and southwest VA. If we see any minor flooding
issues it will be across the southern areas as mentioned above.
Also, low-end, elevated, instability is seen in soundings
overnight so will include slight chance for thunder.
There is some uncertainty on how POPs play out through the day
tomorrow. We remain in a moist environment with elevated PWATS but
precip will be determined on where the lift is focused, which will
be determined by where the front sets up. The NAM suggests that the
higher POPs shift north through the day tomorrow and into KY,
leaving much of TN valley on the drier side with only slight
chance/chance POPs in place. This idea is currently supported by the
NBM as well. This means that after good coverage of morning showers
we should start to see more spotty showers during the afternoon hours
with much less coverage. Highest POPs for tomorrow will be
focused along the TN/KY/VA state lines, where better lift is
expected.
Temperatures remain well above normal through the period due to the
southwest flow and abundant cloud cover.
&&
.LONG TERM...
(Tuesday night through next Monday)
Issued at 312 PM EST Mon Dec 5 2022
Key Messages:
1. Periods of rain will continue through the week. Some flooding
concerns still present for areas that see repeated rounds of
moderate to heavy rainfall. Best chance for this is generally north
of I-40 mid to late week.
2. Above normal temperatures Wednesday and Thursday will gradually
cool into the weekend.
Discussion:
Tuesday night through most of the rest of the work week will
continue to be cloudy, rainy, and pretty warm. Quasi-stationary
boundary will remain laid out in the southern Ohio Valley and
sometimes dipping into the Tennessee Valley. Continuous moisture
will be fed into the region as the low level flow generally remains
out of the south/southwest. Models continue the trend of keeping the
boundary and axis of heaviest precipitation Tuesday night into
Friday to our west and north, along West/Middle TN up into southern
KY. This is still close to the eastern Tennessee valley, and
therefore we`ll still likely see waves of rain throughout the week,
but am still expecting QPF amounts to be the highest further west and
north. For the middle of the week, areas north of Interstate 40, and
the Cumberland Plateau will likely see the highest rainfall totals.
Have continued to keep QPF amounts close to NBM/WPC guidance with a
slight bump up in totals in areas north of Interstate 40, and a
slight decrease in southeast TN into southwest NC. Forecasted
amounts generally remain 2-3" for the week with mostly light rain
expected, and periods of more moderate rain at times.
Model discrepancies crop back up as we move into Friday with regards
on how to handle the low moving into the Great Lakes region and
finally forcing through the front, and drying out the area. Will
continue with PoP chances lingering into Friday afternoon, but as we
get closer to the end of the week, hopefully we`ll be able to trim
back the temporal extent of the PoPs when models come into better
agreement on timing.
We`ll take a break from rain heading into the weekend before another
front that is forecasted to quickly sweep through the eastern U.S.
during the first part of next week. This system should help to usher
in a period of colder weather to start of next week.
&&
.AVIATION...
(00Z TAFS)
Issued at 614 PM EST Mon Dec 5 2022
Highly variable conditions are expected at the TAF sites as rain
spreads across the area tonight and tomorrow. Conditions have been
varying from VFR to IFR across the TN Valley, depending on where
the heavier rain occurs. CHA is expected to have the best chance
of IFR vis and cigs tonight as rain will be heavier there, with
TYS expected to have predominantly MVFR conditions with periods of
cigs dropping to IFR. At TRI, downslope winds off the mountains
have kept cigs VFR, but this should drop to MVFR when rain
increases there tomorrow morning. MVFR cigs will likely persist
through tomorrow, with IFR cigs possible.
&&
.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN 48 64 59 70 / 100 70 60 60
Knoxville McGhee Tyson Airport, TN 42 64 58 69 / 100 80 70 80
Oak Ridge, TN 43 61 56 67 / 100 80 80 80
Tri Cities Airport, TN 47 62 54 66 / 90 80 70 80
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&
$$
SHORT TERM...DGS
LONG TERM....ABM
AVIATION...DGS
Area Forecast Discussion
National Weather Service San Diego CA
130 PM PST Mon Dec 5 2022
.SYNOPSIS...
Partly cloudy cool weather will prevail the rest of this afternoon.
A colder system will bring light showers late tonight through
Tuesday night. Gusty westerly winds will occur at times through
Tuesday night in the mountains and deserts. Fair and dry but
continued cool weather will follow later Wednesday through Saturday.
Another system could bring more precipitation Saturday night
and Sunday.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
Partly cloudy conditions prevailed early this afternoon with a mix
of stratocumulus and cirrus. Temperatures were mostly in the upper
50s and lower 60s west of the mountains.
Broad troughing covers the western US with the main upper low just
west of Eureka. That upper low will move southeast to the Mojave
Desert by Tue night. RH values of mostly 90+ percent will extend
from near the surface to around 500 MB according to NAM and local
WRF late Tuesday afternoon, though dynamics will be modest including
little or no surface front. Some instability will occur with local
CAPE values over 200 J/kg late Tuesday/Tuesday night. GEFS/ENS
Ensemble members show mostly 1/10 inch or less near the coast and
mostly less than 1/4 inch near the coastal mountain slopes, but
given the convective banding that the HRRR and our local WRF are
indicating, there could be local amounts over 1/4 inch, and the 1.3
km resolution Cansac WRF shows some amounts around 1/2 inch in the
San Diego County Mountains. Hourly rainfall rates look mostly slim
in the high-resolution models, possibly up to 0.25 inch but mostly
less, so the risk of flooding or debris flow is minimal. Since this
will be a cold system, with 850 MB temperatures around 2 deg C, the
snow levels could fall to around 5000 feet MSL, especially Tue night
when nocturnal cooling and the coldest profile will occur. Thus,
a few locations in the mountains could get 1-3 inches of snow,
mainly above about 6000 feet.
We will continue with long-wave troughing over the West Coast after
the upper low passes to the east Wednesday due to a strong upper
trough off the Pac NW/British Columbia coast. A wave will deepen the
long wave trough this weekend and could bring some mostly light
precipitation Saturday night and/or Sunday. Enough ensemble
members and even WPC QPF indicate some measurable precip, so we will
add at least a slight chance of rain Sunday. Due to the long wave
troughing, don`t expect any warm weather anytime soon with daytime
highs 5-10 deg F below seasonal averages through early next week.
Nighttime lows will not be as far below average, and so far, NBM
10th percentile temperatures show the risk of valley frost to be low
late this week.
&&
.AVIATION...
052120Z...SCT-BKN clouds 1500-2500 ft MSL through 03Z Tue. Low
clouds increasing in coverage again aft 03Z Tue. Periods of BKN cigs
with VIS 1-3SM during showers between 06Z and 15Z Tue. Coastal
slopes and higher terrain will be obscured through Tue.
Mtns and Deserts...W-NW winds gusting 25-35 kt locally 45 kt through
today. MOD up/downdrafts and LLWS expected over/east of mtns.
&&
.MARINE...
There is a slight chance of light showers tonight through Wednesday
morning. Otherwise, no hazardous marine conditions are expected
through Friday.
&&
.SKYWARN...
Skywarn activation is not requested. However weather spotters are
encouraged to report significant weather conditions.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...None.
&&
$$
PUBLIC...Maxwell
AVIATION/MARINE...PG
Area Forecast Discussion
National Weather Service Tucson AZ
141 PM MST Mon Dec 5 2022
.SYNOPSIS...Patchy fog in the morning and drier conditions for
Tuesday. Another passing weather system on Wednesday will bring a
chance of showers to areas northeast of Tucson and cooler
temperatures areawide. Then dry conditions are expected into the
weekend with gradually moderating temperatures.
&&
.DISCUSSION...20z Visible satellite shows the last remnants of
the low stratus clouds and fog burning off in the valleys of
Southeastern Arizona. The fog took a little longer to burn off as
many locations observed 1/4 mile of visibility, or in some cases a
car length away. The sun has been trying to burn all of the fog
and the low stratus to dry out the area, but there was a lot of
cloud cover. So, the delay in the burned off has the potential
for another round of fog for Tuesday morning. Plus, with a good
radiation inversion developing during the night and the very light
winds, we can expect patchy fog for a few hours on Tuesday
morning. HREF and HRRR model runs shows patchy fog developing in
valleys with very isolated areas of dense fog such as near
riverbeds or bodies of water. Overall, the fog will not be as
severe as it was this morning due to dew point depression being
near 3 points instead of zero...like it was this morning. By 9am
Tuesday, any fog or low stratus will be burned off to pave the way
for a drier and sunny day with moderate daytime temperatures.
By Wednesday, a storm system will drop into region to bring some
showers mainly north and east of Tucson and cooler temperatures
areawide. The ensemble models are not enthusiastic for showers in
Tucson, but it could change if the shortwave trough deepens in
the next 24 hours. As for now, the favorite area is still north
and east of Tucson.
Thursday and through the weekend, the synoptic pattern
becomes a zonal and allowing us to dry out. Ensembles are hinting
at another storm system to come into the region by Monday with
another tease of showers. The ECMWF ENS model is optimistic on
the precipitation side while the GEFS is leans a little dry, aka
a sprinkle for Tucson for ten minutes.
&&
.AVIATION...Valid through 07/00Z.
FEW-SCT lower level clouds 2-5k ft AGL will continue thru 06/02z
and slowly becoming SKC till the end of the forecast period.
Patchy fog can develop after 06/06z mainly in valleys, including
KOLS, KDUG, and KTUS. By 06/16z the fog should start to lift and
burned off to clear skies. Expect westerly winds less than 8 kts
through 06/04z and becoming variable less than 5 kts until 06/18z
and returning to westerly flow at 8-12kts. Aviation discussion not
updated for TAF amendments.
&&
.FIRE WEATHER...Patchy morning fog can be expected in valleys
tomorrow and clearing by mid-morning. Mostly dry conditions
expected for the rest of Tuesday as dewpoints gradually drop. A
passing weather system on Wednesday will bring a threat of showers
to areas north and east of Tucson along with cooler temperatures.
Dry conditions are then expected into the coming weekend before
another weather system passes by late Sunday/Monday bringing a
threat of showers.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
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