Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 01/18/21
AREA FORECAST DISCUSSION
National Weather Service Wakefield VA
916 PM EST Sun Jan 17 2021
.SYNOPSIS...
A series of dry surface troughs will cross the area early this week.
Meanwhile, high pressure slides southeast across the southern states
through Wednesday. Low pressure moves east but remains south of the
local area Thursday and Friday.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
As of 915 PM EST Sunday...
Not much in the way of changes to the current forecast. The most
notable change was to add a slight chance of rain/snow showers
across the far southwest (mainly Mecklenburg, Lunenburg,
Brunswick, Greensville, and Northampton NC counties) later
tonight. Latest high-res model guidance (particularly the HRRR
and RAP) continue to hint at the chance for a few showers with
a weak, mid-level shortwave tonight. Not anticipating any
notable QPF, but wouldn`t be surprised to see a few rain drops
or snowflakes across the SW. Otherwise partly cloudy skies/dry
conditions are expected for much of the area through the night.
SW winds remain elevated ~5 knots through the night. Fairly
similar low temperatures expected tonight compared to last
night, with lows ranging from the upper 20s to lower 30s (mid
30s at the coast/far SE).
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY NIGHT/...
As of 200 PM EST Sunday...
Little change seen in the overall synoptic pattern thru mid week as
the local area remains in a dry cyclonic flow arnd the deep area of
low pres well to the ne and high pres sliding ese across the sern
states. Models show a series of trofs rotating arnd this feature
with only enuf moisture to produce periodic cloud coverage. This
will also continue the wsw (downsloping) wind flow thru Tues, bcmg
NW by Wed behind a cold front. Highs Mon/Tue upr 40s-lwr 50s. Cooler
Wed with highs in the 40s. Lows Mon/Wed nites mid 20s-lwr 30s, with
upr 20s-mid 30s Tue nite.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
As of 200 PM EST Sunday...
Took pcpn out Thurs/Fri as the models have now kept the northern
extent of the first batch of moisture with the srn low across the
Carolinas. The GFS tries to bring a bit of pcpn north towards the
NC/VA border Fri nite ahead of a cold front as a second batch of
moisture moves ene across the Carolinas. This then gets pushed se
as Canadian high pres builds in from the nw early Sat. Meanwhile,
the ECMWF suppresses the systm south. The high dominates thru Sun
with the next systm apprchg from the west Sun nite.
Although I probably will end up getting burned by later model runs,
upshot from today`s data shows a "rare" 7 day dry forecast for the
middle of Jan. Highs Thurs/Fri mid 40s-lwr 50s. Lows Thurs nite in
the 30s. Lows Fri nite mid 20s-lwr 30s. Colder next weekend with
highs in the upr 30s-lwr 40s with incrg clouds Sun.
&&
.AVIATION /02Z MONDAY THROUGH FRIDAY/...
As of 630 PM EST Sunday...
VFR conditions continue through the 00z forecast period. SCT-
BKN mid/high level clouds are expected to move across the
region Monday morning into the afternoon. Gusty WSW winds
around 5 to 10 knots tonight, increasing to 10 to 15 knots with
gusts to around 20 knots by Monday afternoon.
OUTLOOK...
A persistent pattern keeps VFR conditions through Wed. Low
pressure passes south of the region Thurs/Fri.
&&
.MARINE...
As of 300 PM EST Sunday...
Improving conditions across the marine area this afternoon with
surface low pressure north of Maine and high pressure building in
from the southwest. Winds are westerly around 10 kt in the Bay with
10-15 kt more prevalent offshore. Waves are 1-2 ft with seas 2-4 ft.
Cancelled remaining SCA headlines for the northern coastal waters as
seas continue to fall this afternoon. Winds become W-SW this evening
and increase to ~15 kt in the Bay and ~15-20 kt offshore. A few
gusts to 20 kt are possible across the northern Bay zones late
tonight but coverage and duration are too low to warrant further SCA
headlines. An upper trough and weak surface reflection/front will
cross the region Monday afternoon/early evening with winds
increasing to 15-20 kt. Short-lived SCA headlines (6-9 hrs) are
possible for portions of the Bay and Currituck Sound Monday
afternoon. Winds are forecast to remain below SCA thresholds from
Monday evening until midweek when another front is expected to cross
the region with increased winds. Waves generally in the 1-3 ft range
with seas forecast to remain 2-4 ft through the upcoming week.
&&
.EQUIPMENT...
As of 200 PM EST Sunday...
NWS Wakefield (KAKQ) radar has suffered a transmitter malfunction
and is offline. The radar is expected to remain offline until
Tuesday afternoon (01/19/2021). The Newport/Morehead City radar
(KMHX) is also offline due to a scheduled generator upgrade.
Users are encouraged to access adjacent radars from Blacksburg
(KFCX), Raleigh (KRAX), Sterling (KLWX), and Dover AFB (KDOX)
through the outage period.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...None.
NC...None.
VA...None.
MARINE...None.
&&
$$
SYNOPSIS...MPR
NEAR TERM...AJB
SHORT TERM...MPR
LONG TERM...MPR
AVIATION...AJB
MARINE...RHR
EQUIPMENT...
AREA FORECAST DISCUSSION
National Weather Service Albany NY
947 PM EST Sun Jan 17 2021
.SYNOPSIS...
Cloudy with continued snow showers and flurries through
Monday as a cold front approaches and crosses the region. The best
chances for snow will be in the western Mohawk Valley and across the
high terrain of the southern Green Mountains tonight into tomorrow.
Fair and colder Monday night with more snow showers Tuesday and
Tuesday night as a low pressure system approaches and crosses the
region.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
As of 947 PM EST...A short-wave trough continues to approach
the forecast area tonight. A cold front is slowly approaching
from northern NY and northern New England.
A little lull in the snow shower activity but it should pick
back up west of the Capital Region between 10 pm - midnight
with some lake moisture being tapped with conditional
instability. The upstream radar trends show light snow over
western and central NY. This is associated with weak isentropic
lift as the boundary stalls a bit. The 00Z KALY sounding is dry
below 850 hPa and should moisten a bit overnight. The 3-km HRRR
has come in lighter with snow showers overnight into the Capital
Region and down the Mohawk Valley. We will see if these trends
continue.
We retooled the PoPs a little bit based on the
radar trends and the 3-km HRRR past few runs. The best chance of
accumulating light snow will be along and just north of the
I-90 corridor in the western Mohawk Valley. We continued the
highest PoPs here with 1-2" possible tonight.
Upslope snow will pick across the southern Green Mountains after
midnight. Snowfall accumulations will be very light across most
the region (dusting to a half inch) with some light to moderate
snowfall (2-4") with a few higher amounts possible above mainly
2000 feet in the southern Greens.
The clouds may thin a bit over the mid Hudson Valley and NW CT.
The rest of the region remains mostly cloudy/cloudy. Lows will
be in the teens and lower 20s over the southern Adirondacks and
southern Greens and 20s to around 30F over the rest of forecast
area.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY NIGHT/...
Upper trough axis and cold front cross the region Monday with
flow becoming nearly zonal Monday night. However, the northern
stream remains active and additional short waves dive out of
central Canada and will move across the Great Lakes Region
Tuesday night.
Chances for snow showers diminish Monday as the day progresses
as the trough axis moves off to the east. Expecting another
cloudy day with slightly above normal temperatures from the
lower 20s in portions of the southern Adirondacks to around 40
degrees in the mid Hudson Valley. Expecting partial clearing
Monday night and turning colder with lows dropping into the
single digits across the southern Adirondacks to mid 20s in the
mid Hudson Valley. Clouds on the increase Tuesday along with
chances for snow showers especially west of the Hudson River
Valley with some lake enhancement into the western Adirondacks
and western Mohawk Valley Tuesday night. Not as cold Tuesday
night.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
The weather pattern is finally resembling that of a La Nina. The two
main drivers of our weather during the long-term period will be a La
Nina and a high latitude atmospheric block. That said, the weather
pattern during the extended period will remain unsettled with a
series of shortwaves that will bring chances of snow showers to
eastern New York and western New England. Overall, light snow
amounts are expected with higher elevations via lake effect and
upsloping being most favored to see the highest amounts.
With Lake Ontario`s average surface temperature of 6C and 850 hpa
temperatures on the order of about -14C, delta T values between the
two will be more than sufficient enough to support lake effect
showers. So given the thermodynamics in place, we start off the long
term period with lake effect snow showers taking place across our
western zones (i.e. SW Adirondacks, western Mohawk Valley, Schoharie
Valley) and upslope snow taking place across our eastern zones (i.e.
southern VT, Berkshires, Rensselaer Plateau). This snow will be
associated with a shortwave, albeit weak, that will be passing over
the area. Snow showers are also possible across the Hudson Valley
including the Capital District on Wednesday. All of this activity
will come to an end by Wednesday night.
We`ll get a very brief reprieve from any snow shower activity
Wednesday night because right on the heels of this will be another
shortwave associated with a storm system approaching from our
northwest (Ontario, Canada).
Snow showers in connection with this next storm system will spread
over the area from northwest to southeast Thursday morning into
Thursday afternoon. Synoptic snow will persist for much of the
forecast area (that includes the Hudson Valley and Capital District)
through the day on Thursday before winding down Thursday night. By
Thursday night, lake effect snow (LES) showers will develop
impacting our western zones while upsloping will persist over
southern VT possibly extending into the Berkshires. With multiple
mid to upper level perturbations expected to move over the region,
snow showers will persist through the day on Friday. Snow showers
(mainly lake effect and upslope) will dwindle during the day on
Saturday. The Hudson Valley and Capital District should be mostly
dry on Saturday.
Sunday will be dry areawide with high pressure located to our north.
Forecast models are advertising another storm system that will have
the potential to bring the forecast area another round of wintry
weather early next week.
As far as temperatures, the overall scheme will resemble that of a
La Nina (cool north U.S. vs. warm southern U.S.) with flat upper
troughing over the northern U.S. and flat ridging over the southern
U.S. For the balance of the long-term forecast period, expect a
cooler than normal bias in temperatures across the forecast area.
High temperatures will mostly be in the 20s (teens higher
elevations). Outside of Thursday night/Friday morning, low
temperatures across the mid-Hudson Valley will be in the teens with
lows in the single digits elsewhere. The southern Adirondacks and
possibly parts of the Greens on southern VT will see low
temperatures falling below zero during this period.
&&
.AVIATION /03Z MONDAY THROUGH FRIDAY/...
An upper level disturbance and a cold front will move towards
and across the region tonight into tomorrow.
VFR conditions will continue early this evening at
KGFL/KALB/KPSF/KPOU with cigs in the 3.5-6 kft AGL range. Some
lake moisture will be utilized, as a short-wave trough approaches
from the south and west. Clouds bases will lower and some light
snow or intermittent snow showers will impact KALB-KPSF
northward starting between 06Z-09Z/MON, and continue until the
late morning in the 14Z-17Z/MON time frame. We used TEMPO or
PROB30 groups to bring the snow showers/light snow into KALB
first 06Z-09Z/MON, and then KPSF/KGFL 09Z-14Z/MON. We are
expecting mainly MVFR cigs/vsbys but some reductions to IFR
level vsbys are possible. KPOU will see some thinning of the
clouds overnight, as the low-level flow backs ahead other
disturbance and should stay VFR overnight.
MVFR cigs in the 2-3 kft AGL range will linger until the early
pm at KALB/KGFL/KPSF with some snow showers and flurries. We
kept VCSH groups in until 19Z at KALB/KGFL, and continued them
at KPSF. Cigs should rise to VFR levels in the 4-5 kft AGL range
at these two terminals after 19Z/MON. KPSF may hover at high
MVFR levels through the afternoon with a VCSH group included.
Further south, KPOU may see stratocumulus return in the pm with
the cold front moving through with cigs around 5 kft AGL.
The winds will be come light this evening from the south to
southwest at 3 to 7 kts. They will increase from the southwest
to west at 8-10 kts in the late morning and veer to the west in
the afternoon with the frontal passage at 8-12 kts with a few
gusts around 20 kts at KALB/KPSF.
Outlook...
Monday Night: No Operational Impact. NO SIG WX.
Tuesday: Low Operational Impact. NO SIG WX.
Tuesday Night: Low Operational Impact. Slight Chance of SHSN.
Wednesday: Moderate Operational Impact. Breezy. Chance of SN.
Wednesday Night: No Operational Impact. NO SIG WX.
Thursday: Moderate Operational Impact. Chance of SN.
Thursday Night: Moderate Operational Impact. Chance of SN.
Friday: Low Operational Impact. Slight Chance of SN.
&&
.HYDROLOGY...
No widespread hydrological issues are expected through the
upcoming week.
Precipitation will be in the form of snow and light QPF amounts
as a series disturbance approach and cross the region.
For details on specific area rivers and lakes, including observed
and forecast river stages and lake elevations, please visit the
Advanced Hydrologic Prediction Service /AHPS/ graphs on our
website.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
MA...None.
VT...None.
&&
$$
SYNOPSIS...IAA/Wasula
NEAR TERM...IAA/Wasula
SHORT TERM...IAA
LONG TERM...Evbuoma
AVIATION...Wasula
HYDROLOGY...IAA
Area Forecast Discussion
National Weather Service La Crosse WI
528 PM CST Sun Jan 17 2021
.SHORT TERM...(This evening through Monday)
Issued at 202 PM CST Sun Jan 17 2021
An upper low that passed by to our south overnight is slowly
retreating towards the Ohio Valley this afternoon. Meanwhile very
weak low-amplitude ridging and a drier airmass are encroaching from
the northwest, but a couple subtle shortwaves lie just upstream over
northern MN and eastern ND. On a smaller scale, some weak low level
frontogenesis bands have continued to produce light snow/flurries
and perhaps some patchy freezing drizzle at times across portions of
southwest and west-central WI since this morning. Conditions have
certainly improved since last night, and current weak radar returns
are not resulting in any reported impacts. Expect an overall
weakening pattern heading into the evening hours as the fgen slowly
fizzles out, but the RAP indicates some reinvigoration of the fgen
banding in this same general area later this evening. Have therefore
kept some slight chance PoPs going near and north of of the I-94
corridor into tonight. Hi-res guidance, particularly the RAP/HRRR,
has done a decent job capturing today`s weak precipitation so relied
on that for the general area of fgen-banded precip tonight. Will
likely need to be tweaked this evening as trends evolve, however.
Forecast soundings generally show low level saturation extending
deep enough into the snow-growth zone (or at least a seeder-feeder
setup in place) to support mainly light snow chances, but can`t rule
out a lack of ice in the clouds at times that could produce some
patchy freezing drizzle. The setup does not look to be a repeat of
last night, however. A light coating of snow will likely be the
extent of any accumulations.
Additionally, the aforementioned weak shortwaves will drop southeast
tonight, grazing our far western counties perhaps with a bit of
light snow. Most GEFS/EPS ensemble members show a weakening band of
light snow clipping portions of southeast MN and northeast IA
tonight, but current activity along the ND/MN border is far from
impressive. So have just gone with slight chance PoPs for this
feature as well. Little to no accumulation expected with this
feature as it passes through. Lows in the teens to around 20.
A drier airmass settles into the area on Monday with weak cyclonic
flow overhead. This should result in a dry day for the area, but
mostly cloudy skies will persist. Highs will be in the 20s.
.LONG TERM...(Monday night through Sunday)
Issued at 202 PM CST Sun Jan 17 2021
Generally under a west to northwesterly flow pattern through the
work week, with relatively dry conditions anticipated over the next
several days. However, a passing shortwave introduces some small
chances for precipitation on Tuesday. Forecast soundings would
suggest mainly light snow with sufficient saturation in the DGZ.
Temperatures start out on the cooler side with Tuesday afternoon
temperatures increasing into the teens to low 20s and overnight
temperatures decreasing into the single digits. Milder conditions
are in store over the middle part of the week with some influence of
warm air advection under more westerly oriented winds. High
temperatures in the upper 20s to 30s are expected Wednesday and
Thursday.
A stronger system dives southeastward through central Canada into
southern Ontario and northern Great Lakes region. However, better
chances for precipitation are expected to remain north of the
region. Colder conditions are anticipated as a surface cold front
extending from this system swings through the region Thursday night.
High temperatures on Friday may only get into the teens to low 20s
with overnight lows dipping to around 0. Next best chance for
precipitation returns over the weekend, but it is still too early to
determine exact details. Will continue to monitor as this
potentially impactful system draws closer.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 528 PM CST Sun Jan 17 2021
Pesky cyclonic flow will continue over the area through the period
with a weak trough moving through. Lift associated with this
trough will likely produce some very light snow or flurries at
times with minimal/trace amounts expected. Not discounting a brief
period or two of light freezing drizzle as well. Otherwise, IFR
cloud cover expected at KRST through 17z Monday, lifting into MVFR
range by afternoon. KLSE expected to remain MVFR through the
period. Winds will be northwesterly, generally below 10kt.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
IA...None.
&&
$$
SHORT TERM...Kurz
LONG TERM...Peters
AVIATION...DAS
Area Forecast Discussion
National Weather Service Boise ID
821 PM MST Sun Jan 17 2021
.DISCUSSION...Breezy post-frontal west and northwest winds are
starting to subside across the area this evening, with the
exception of the Magic Valley. For the lower Treasure Valley, Long
Valley, and central Harney County, areas of fog and low stratus
is anticipated overnight tonight as dewpoints remain relatively
high. High pressure will gradually return Monday and Tuesday, and
temperatures will be similar each day this week.
&&
.AVIATION...Mostly VFR. However, there will be areas of MVFR/IFR
in low stratus and fog that will expand in coverage tonight.
Conditions will improve after 16Z Monday. Surface winds: west to
northwest 5 to 15 kt, except 20 to 30 kts near KJER through 08Z.
Winds aloft near 10k feet MSL: northwest 30 to 45 kt.
&&
.PREV DISCUSSION...
SHORT TERM...Tonight through Tuesday night...Weak cold front
from the northwest has so far produced almost no pcpn. NamNest
hi-res model continues to forecast showers through late
afternoon, but HRRR has adjusted drier and now looks correct.
In any case, the weak front will be south/southeast of our CWA
by early evening. After that, except for possible flurries in
the Idaho central mountains Monday, near zero chance of pcpn
through Tuesday night. Statistical guidance develops patchy fog
overnight in the Treasure Valley between Boise and Ontario, but a
little denser in Harney County (Burns area). Little or no fog
indicated elsewhere. Northwest flow aloft today will change to
colder, drier northerly flow Monday, then dry northeasterly Tuesday
as a Pacific upper ridge comes inland. The ridge will warm higher
elevations Tuesday but valleys will stay cold. Winds will be
generally light, except moderate west/northwest winds in the Snake
Basin Monday afternoon.
LONG TERM...Wednesday through Sunday...An upper ridge will remain
overhead on Wednesday with dry northwest flow, resulting in
temperatures near to a couple degrees above normal. Models continue
to depict a deep upper trough moving into the Pacific Northwest on
Thursday and shift it inland from northwest to southeast Thursday
night and Friday. This will bring a chance of snow to parts of the
area. Models differ on the exact track of the trough, with most
models keeping the best moisture and dynamics to our west and south.
However, some of the models bring the core of the trough overhead,
which would result in a better chance of snow across the area. The
trough will usher in a cooler airmass for the weekend, with
temperatures a few degrees below normal on Saturday and Sunday.
Drier northerly flow aloft is favored on Saturday. Another strong
trough will take aim at the Pacific Northwest on Sunday, with a
chance of snow returning to the forecast area.
&&
.BOI WATCHES/WARNINGS/ADVISORIES...
ID...None.
OR...None.
&&
$$
www.weather.gov/Boise
www.facebook.com/NWSBoise
www.twitter.com/NWSBoise
DISCUSSION...SH
AVIATION.....SP
PREV SHORT TERM...LC
PREV LONG TERM....ST
Area Forecast Discussion
National Weather Service Charleston SC
910 PM EST Sun Jan 17 2021
.SYNOPSIS...
High pressure will prevail through much of next week. A weak
cold front is expected to pass through the area Thursday and
Friday.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
The back edge of the cirrus is poised to move offshore soon with
clear skies prevailing thereafter. A band of mid-level clouds
moving across portions of Mississippi and Alabama are timed to
push from west-east across area between 06-12z. This will bring
a period of mostly cloudy skies during the early morning hours
for many locations. While the sub-cloud layer is quite dry per
the 17/00z KCHS raob, a sprinkle or two can not be completely
ruled out as the band pushes through. In fact, both the RAP and
H3R simulated layer composite reflectivity fields depict some
very light returns brushing the far interior areas from Millen
to Walterboro and McClellanville. However, measurable rainfall
is highly unlikely and gridded pops 0-2% were maintained for the
late evening update. Lows from the mid 30s well inland to the
upper 30s near the coast with lower 40s at the beaches look on
track.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY/...
Dry high pressure will persist Monday into Tuesday, maintaining
clear skies. A weak upper disturbance will pass through Tuesday
night and Wednesday. Very limited moisture and westerly flow
should limit the chance for precipitation. However, a scattered
to broken cloud layer will move through Tuesday night. High
temps will show a gradual warming trend during the period with
readings in the lower 60s just about everywhere by Wednesday.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
Surface high pressure will begin to weaken Thursday as broad
low pressure tracks over Great Lakes region and into the
Northeast US. Gradual coupling of the polar and subtropical jet
will produce a zonal jet streak over the Ohio Valley/Mid
Atlantic states. Upper divergence in the right entrance region
of the jet will spawn a surface low over TX that will propagate
eastward toward the Carolinas. A weak, slow-moving cold front
associated with the low approaches the region from the west
Friday. Showers ahead/along the front are possible
Friday/Saturday. Thereafter, high pressure is expected to build
in the wake of the front. Slightly above normal temps will
persist Thursday and Friday with highs in the 60s, whereas
Saturday temps should return to near normal with the passage of
the front.
&&
.AVIATION /02Z MONDAY THROUGH FRIDAY/...
VFR.
Extended Aviation Outlook: VFR.
&&
.MARINE...
Tonight: Dry and cool sfc high pressure will prevail across
coastal waters while a large mid-upper lvl trough shifts toward
the Mid-Atlantic States late. A h5 shortwave rounding the base
of the trough will advance across local waters late tonight,
helping produce some cold air advection across the Atlantic
heading into daybreak. The pressure gradient should tighten
modestly and west winds gusting upwards to 15-20 kts are likely
after midnight. There is even a small chance of seeing wind
gusts up to 25 kt across northern South Carolina waters where
cold air advection is strongest, but a large portion of the low-
lvl wind field would have to mix toward the sfc to support a
long enough duration for a Small Craft Advisory. At this time,
wind gusts have been capped just below 25 kt. Seas will
gradually build during the overnight period, peaking near 3-4 ft
(highest across northern South Carolina waters and offshore
Georgia waters).
Monday through Friday: High pressure will continue to build
over the waters Monday through Tuesday. 20-30 kt westerly low-
level winds on Monday could produce some 25 kt gusts over the
outer portions of the Charleston nearshore waters and the GA
offshore waters. At this point it`s not clear whether frequent
25 kt gusts will occur so we held off on the issuance of a Small
Craft Advisory. Thereafter, benign conditions anticipated (1-2
ft seas and W/SW winds less than 15 kt) until Friday when
another WSW wind surge is anticipated.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...None.
SC...None.
MARINE...None.
&&
$$
Area Forecast Discussion...UPDATED
National Weather Service Corpus Christi TX
946 PM CST Sun Jan 17 2021
.DISCUSSION...Light southeast flow has pushed higher surface
moisture inland with dewpoint temperatures in the upper 40s to
lower 50s from the Brush Country to the Coastal Bend. Expect
radiational fog to form over the northern portions of deep
south Texas late tonight that will move northward into the
Brush Country and Coastal Bend. Latest HRRR model along with
SREF probabilities give more confidence that fog may become
dense over these areas.
&&
.PREV DISCUSSION... /Issued 557 PM CST Sun Jan 17 2021/
AVIATION...A weak surface high was located over the Victoria
Crossroads with a light onshore flow over the Coastal Bend has
brought dewpoints in the lower 50s inland. This higher boundary
layer moisture will continue to move inland into the Brush Country
this evening. Expect radiational fog/MVFR vsbys to form over the
southern Brush Country into the Coastal Bend by 09Z, and then
deteriorate to LIFR by 11Z with low stratus/fog moving north
into the northern Brush Country between 12-13Z. The Victoria
Crossroads will be a little drier, so only expecting MVFR vsbys
with IFR vsbys possible from 11Z-16Z. The fog will continue
over the rest of south Texas through 16Z with improvement to IFR
ceilings/MVFR vsbys between 16Z-18Z. Southerly winds will become
gusty Monday afternoon with VFR conditions area wide.
PREV DISCUSSION... /Issued 402 PM CST Sun Jan 17 2021/
SHORT TERM (Tonight through Monday Night)...
Deterministic runs move an upper trough/low across the Midwest/ERN
CONUS while a series of upper disturbances result in the
development of a mean upper trough over the WRN CONUS/Baja CA
during the period. The LFQ of an upper jet streak is predicted to
approach/enter the CWA Monday night. Increasing onshore
flow/moisture expected over the CWA/MSA, with PWAT values
near/above normal over the ERN CWA Monday night (per NAM/GFS.)
Anticipate that increasing upper forcing and moisture will
contribute to isolated showers over the ERN CWA Monday night. NAM
deterministic output/SREF probabilistic output suggest that fog
may occur over the inland CWA tonight/early Monday morning.
LONG TERM (Tuesday through Sunday)...
A surface low pressure located over Mexico Monday will approach the
area Tuesday and Wednesday. With onshore flow and the low pressure
to the west, WAA and moisture will continue to being pumped into
South Texas. A cold front is expected to attempt to push through
South Texas mid week, but appears like it will wash out just north
of our area. With PWATs expected to be near 1.5 inches or higher
Tuesday through the end of the week, which is in the 99th percentile
for this time of the year. With the approaching disturbance and near
record PWATs, isolated to scattered showers will be possible Tuesday
through Wednesday night with a slight chance of thunderstorms. Rain
chances are expected to taper off Thursday morning, however, due to
elevated PWAT values, mainly across the Coastal Bend, left enough
PoPs for slight chance of showers through the end of the work week.
Models are showing the possibility our next cold front sometime this
weekend, however, due to model disagreement the timing of the
front is still up in the air.
With the increase in cloud cover and possible showers Tuesday and
Wednesday, highs are expected to remain cool with temperatures
ranging in the lower to upper 70s. With onshore flow continuing and
cloud cover clearing up, temperatures are expected to warm into the
upper 70s and lower 80s across much of the area Thursday through
Saturday. Low temperatures are expected to remain mild in the lower
to mid 60s Tuesday night through Saturday.
MARINE...
In response to the development of upper level disturbances to the
west, increasing onshore flow and moisture expected during the
period. An upper level jet and significant moisture may result in
isolated showers Monday night. Small Craft Exercise Caution
conditions expected over the coastal waters Monday, with Small
Craft Advisory conditions over the offshore coastal waters Monday
night. A moderate to strong onshore flow will be in place until
Tuesday night, then becoming weak to moderate for the remainder of
the week. Small Craft Advisory conditions remain a possibility
through Tuesday night due to seas up to 7 feet, and possibly
returning next weekend. In the meantime, Small Craft Exercise
Caution conditions will be likely Wednesday through Friday night.
Rain chances will increase Tuesday through Thursday as a
disturbance approaches the area with a slight chance of
thunderstorms Tuesday and Tuesday night.
&&
.PRELIMINARY POINT TEMPS/POPS...
Corpus Christi 51 74 62 74 60 / 0 10 20 30 50
Victoria 42 72 60 74 58 / 0 0 20 30 30
Laredo 49 78 62 78 58 / 0 0 10 30 70
Alice 49 78 61 79 60 / 0 10 10 30 60
Rockport 52 71 62 74 59 / 0 10 20 30 40
Cotulla 47 79 61 76 56 / 0 0 10 40 80
Kingsville 51 77 62 76 60 / 0 10 20 30 60
Navy Corpus 57 70 64 71 63 / 0 10 20 30 50
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...None.
GM...None.
&&
$$
TMT/89...SHORT TERM
Area Forecast Discussion
National Weather Service Des Moines IA
533 PM CST Sun Jan 17 2021
...Updated Aviation Discussion...
.DISCUSSION.../Tonight through Sunday/
Issued at 254 PM CST Sun Jan 17 2021
Take Home Points:
*Multiple time frames for light snow next couple days
*Seasonable temperatures into mid-week, then warmer Wed/Thur
*Another round snow next weekend looks increasingly possible
Discussion:
Through Tuesday the general summary could be said to be: death by a
thousand flurries/light snow.
But first, the potent shortwave that passed through the state
overnight went roughly according to plan with light snowfall
accumulations, around an inch or two, over eastern portions of the
state and tapering off into central Iowa. However, a secondary
treat, weak shortwave/fgen band, developed over central Iowa this
morning and resulted in anywhere from a dusting to under two inches
of snow roughly along the I-35 corridor including the Des Moines
metro.
Back to the thousand flurries/light snow... synoptic and hi-res
guidance continues to signal multiple opportunities for
flurries/light snow driven by multiple short waves. While none look
to be of real significance, each may be capable of producing
localized 1+ inch amounts or more.
The first of which will be a very weak short wave that will slide
across northern/northeast Iowa this evening. While it has been
signaled the last couple of cycles, QPF generation has struggled.
Looking at soundings, it may very well be more of a light freezing
drizzle to light snow/flurries based on lacking to borderline ice
introduction and weak lift. Of note the last couple of HRRR cycles
is an uptick of QPF associated with a low/mid level fgen band. If
this does develop, could certainly see a very localized area receive
measurable snowfall, but there is very limited confidence in picking
out the location, resulting in some broad low PoPs instead.
Next, a stronger shortwave, currently exiting SW Canada into Montana,
will enter the region later Monday morning through the afternoon and
should blanket SW Iowa with predominantly light accumulating
snowfall. Some banded snowfall is likely and will ultimately result
in a narrow area likely receiving an inch or two versus the more
widespread roughly half inch or less within the current forecast.
The hits keep on rolling Monday night into Tuesday as another pair
of shortwaves sweep through central/southwest Iowa and northeast
Iowa respectively. The second of which will be concurrent with more
notable support through the profile and most likely to result in
measurable snowfall over the area. Once again, and similar to the
Monday shortwave, light measurable snowfall around and under a half
inch will be most common, but localized amounts of an inch or
greater will be possible if not likely in areas of any banded
development.
And that "should" bring an end to the numerous rounds of light
snow/flurries for the time being. When all said and done, expect a
fair amount of the state to have seen measurable snowfall, though
most look to only experience one or two of the previously mentioned
shortwaves versus any given area experiencing them all.
Looking into the middle of the week, warmer conditions continue to
the main story with weak ridging to zonal flow sliding in. Have kept
with previous trend of boosting temperatures toward the 75th
percentile with increasing confidence of a strong push of WAA
Wednesday. Some moderation but still on the warm side of normal
Thursday before a cold front originating from a surface low in south
central Canada. With dry air in place, the frontal passage will be
dry and the primary result will be cooler/colder temperatures into
the weekend, including potential for lows into the single digits.
Precipitation chances also continue to be reflected consistently
within the synoptic models by the latter half of the weekend,
yielding what would appear to be widespread mostly light to moderate
snowfall.
&&
.AVIATION.../For the 00Z TAFS through 00Z Monday evening/
Issued at 528 PM CST Sun Jan 17 2021
The endless MVFR stratus deck will remain for the majority of the
forecast period. Some light snow is possible over northeast Iowa
which may impact ALO and MCW this evening with MVFR visibility at
times. Some mid-level dry advection moves across the state late
Monday afternoon and there looks to be a brief break in the lower
stratus deck.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
DISCUSSION...Curtis
AVIATION...Podrazik
Area Forecast Discussion
National Weather Service Peachtree City GA
1028 PM EST Sun Jan 17 2021
.UPDATE...
Shortwave coming across has produced mainly mid level based clouds
and little precip emanating from them according to obs and mPing
reports. Should see some further saturation though and have
increased pops and expanded southward. Accumulation totals remain
unchanged and SPS should suffice in coverage half inch or less
totals.
Deese
&&
.PREV DISCUSSION... /issued 659 PM EST Sun Jan 17 2021/
PREV DISCUSSION... /issued 301 PM EST Sun Jan 17 2021/
SHORT TERM /Tonight through Monday Night/...
Strung out piece of vorticity brought some morning and afternoon
cloudiness across the area but is quickly moving east ahead of the
next system that will affect us tonight. Winds have picked up a
little bit this afternoon with some gusts getting up into the lower
20`s (mph) at a few locations that are a bit more open, and that
will continue until sunset. Tonight, yet another upper level wave
will move across the area moving in from the NW before heading to
the east, providing yet another shot at some high elevation snow
showers in the Appalachians. Hi-res model runs, including the past
several hours worth of HRRR runs, show a 4 to 5 hour window tonight
in which broad synoptic ascent will coincide with favorable
orographic lift and low level moisture to squeeze out a little bit
of snow in the NE mountains. As of now, expect that these
accumulations will remain below half an inch and occur mostly at
elevations above 2000 ft. Minor travel impacts could occur at
elevation, though these should be very isolated. Outside of the
mountains, some very light snow showers or rain showers mixed with
snow showers are possible across north GA, but no accumulations are
expected as temperatures should remain too warm and precipitation
too light.
Tomorrow, expect temperatures to be similar to today. Shortwave
trough moves by and NW flow replaces it. Pocket of mid level dry air
will provide the opportunity for some additional mixing of dry air
downwards into afternoon, so RHs will need to be monitored as these
days are typically where models struggle, keeping them too high.
Given fuel moistures, potential windiness, and possibility of RHs
tanking a bit lower, will need to monitor fire weather conditions.
Lusk
LONG TERM /Tuesday through Sunday/...
Weak upper wave/sfc boundary could bring a low end chance for some
showers to portions of north GA Tuesday night...have kept mainly a
persistence fcst of staying under 15 percent pops with it being
quite a weak feature but cannot rule out trends to raise chance a
bit. Otherwise main focus remains on the more persistent moisture
advection in largely zonal upper stream and resultant more
widespread rainfall Thursday/Friday. Some storm total QPF has come
in decently lower than previous run, but expecting more back and
forth given model discrepancies on moisture axis extent or how
progressive the sfc boundary is across the CWA along with a higher
PWAT airmass. Latest amounts mainly in 1-2 inch range but could be
higher in future updates and will need to watch isolated flood
threat. Little change to rest of fcst and previous discussion
follows...
Baker
PREV DISCUSSION... /Issued 630 AM EST Sun Jan 17 2021/
LONG TERM /Monday Night through Saturday/...
Dry start to the long term forecast as a surface high sinks down
and across the southeast US with slight NW upper lvl flow through
Tuesday evening.
As the high makes its trek southward towards FL, moisture returns
to the CWA on Wednesday as it moves around the edge of said high,
aided by a low pressure system near the California Baja. This low
pressure system will be the next rainmaker across the area
through Friday, although there are still slight model
discrepancies between the Euro and GFS on timing and overall
precipitation coverage as the low is absorbed into the flow and
ejects eastward. The GFS remains the more progressive and wetter
of the two models, with PWATS approaching 1 to 1.5" across the
CWA, while the Euro is still showing a slower and slightly drier
solution. Even with slight coverage discrepancies, kept Chance
PoPs with Storm Total QPF for Thursday morning through Friday
night sitting around 0.5-1" for central Georgia and 1.5-2.5"
across north Georgia.
Model differences continue to round out the extended through
Sunday with the Euro switching sides and becoming the wetter model
run. This is mainly in part to progging slower movement of the
outgoing system and keeping sharper SW flow with the surface high
further north over the Great Lakes Region. This is in comparison
to the GFS which sets the high up over New England and puts the
CWA in a wedging pattern. Still a ways out so went with mid-range
slight chance PoPs for Saturday morning to try and capture the
model differences.
Morgan
AVIATION...
00Z UPDATE...
After a brief respite, BKN conditions will return later this
evening but perhaps not as low as previously thought. Some
guidance indicating higher at 8K ft but will compromise for now
with that and the previous forecast and go around 6k.
Straightforward after that with clearing conditions for Monday and
just some limited gust potential at ATL.
//ATL CONFIDENCE...00Z UPDATE...
High on all elements.
Deese
&&
.PRELIMINARY POINT TEMPS/POPS...
Athens 32 51 30 57 / 5 0 0 0
Atlanta 33 50 30 56 / 5 0 0 0
Blairsville 29 43 27 50 / 20 5 0 5
Cartersville 30 50 28 56 / 10 0 0 5
Columbus 33 56 31 61 / 0 0 0 0
Gainesville 33 49 31 54 / 10 0 0 0
Macon 33 57 29 62 / 5 0 0 0
Rome 31 52 29 56 / 10 0 0 5
Peachtree City 31 53 29 58 / 5 0 0 0
Vidalia 36 57 33 61 / 0 0 0 0
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Deese
LONG TERM....Morgan
AVIATION...Deese
Area Forecast Discussion
National Weather Service Grand Forks ND
952 PM CST Sun Jan 17 2021
.UPDATE...
Issued at 952 PM CST Sun Jan 17 2021
Quite a bit of cloud cover across the Northern Plains and up into
Canada. Not seeing too many holes in the clouds cover, and some
guidence such as the RAP that clear things out and drop temps
lower than -5 don`t seem very likely at this point. Bumped up
clouds and made some minor adjustments to temperatures. Still
think there should be a drop into the single digits across the
north, but below zero looking less likely.
UPDATE Issued at 629 PM CST Sun Jan 17 2021
Fairly large area of clouds continues over the forecast area, and
a few lingering flurries. Will continue with an isolated flurry
mention for a while longer tonight. Temps already down into the
teens in the northern Red River Valley even with cloud cover. Will
keep the lows around zero that we have going for now, but
reevaluate as the night goes on.
&&
.SHORT TERM...(This evening through Monday night)
Issued at 245 PM CST Sun Jan 17 2021
Think the biggest impact in the next few days will be at the start
of the long term forecast, the Tuesday morning commute. That is
discussed in the long term section below.
North-northwest winds are well established now at all the
observations points in this FA. Activity on the Mayville radar
has been on the decrease, but surface observations still show
flurries around the area. May extend their mention into the
evening, as the clouds are holding tough. The parade of weak waves
will continue in the northwest flow, the next one should begin to
move through late tonight, continuing into Monday. At this point,
this one appears to possibly graze the far western FA, so it
should not be very impactful. The next wave arrives late Monday
night, bringing a little light snow to areas west of the Red River
Valley before sunrise on Tuesday. Neither of these waves are
accompanied by strong winds, which will minimize their impact.
.LONG TERM...(Tuesday through Sunday)
Issued at 245 PM CST Sun Jan 17 2021
Overview...
A few chances for minimal impact precipitation will be possible
throughout the week as a few quick moving systems affect the area on
Tuesday, Wednesday into Thursday, and Saturday respectively.
Otherwise, temperature trends will be sporadic as we warm up to well
above normal through Wednesday ahead of precipitation and then drop
back down toward normal by the weekend.
Ensemble guidance is in good agreement with the upper level pattern
for the long term period. Northwesterly flow is expected to stick
around through the late week until an upper level trough looks to
dig in over the western CONUS and shift our flow pattern to a more
zonal direction. The pattern is indicative of colder (near normal
temperatures) air sticking around and at least increased potential
for precipitation for the extended period, which coincides well with
the extended CPC outlooks as well.
Tuesday...
A transient shortwave is expected to ride the northwesterly flow
aloft into the region by Tuesday morning. The weak and quick moving
nature of this system should only result in light accumulations of
an inch or less, but the timing of snowfall onset could introduce
some Tuesday morning commute travel impacts. Cloudy skies will
likely stick around on Tuesday following the passage of the system,
but a westerly surface wind will work to advect temperatures in the
20s to areas west of the Red River Valley, while temperatures east
of the Valley are expected to remain in the teens.
Wednesday & Thursday...
The slight warming trend from Tuesday should continue into Wednesday
as a mid level ridge will briefly position itself over the northern
Plains. This warm bubble aloft and a west-southwesterly wind will
aid in bumping high temperatures on Wednesday into the 30s and low
40s prior to the next shortwave passing through. Ensemble consensus
is currently indicating that precipitation impacts will likely be
confined to the Lake of the Woods area, although some light wintry
precipitation cannot be ruled for other areas north of highway 2.
The primary impact from this system will be the introduction of
colder air and a return to normal temperatures to the forecast area.
Thursday will likely see high temperatures occurring just after
midnight as the aforementioned system moves through. Temperatures
are then expected to fall throughout the day as a north-
northwesterly wind will be advecting in cold air.
Friday & Saturday...
Ensemble guidance at this point is showing a good bit of variance
and as a result, confidence in any one solution is low. That being
said, near normal temperatures are likely to stick around moving
into the weekend. The biggest discrepancies lie with the next low
pressure system, currently expected for next Saturday. The exact
track of the low will determine what, if any, precipitation impacts
may affect the area. Current consensus has some potential for light
snow for areas south of highway 2, but confidence in this solution
is again, decidedly low.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 543 PM CST Sun Jan 17 2021
Fairly large area of MVFR ceilings with a few spots down to IFR
and some isolated flurries. This will continue for much of the
evening. Some sucker holes are not out of the question and some
guidance bounces between MVFR and VFR, but not confident enough
to include any meaningful improvement in the TAFs until tomorrow.
Think there could be some improvement to VFR (or MVFR at KBJI) by
the end of the period. Winds will remain mostly from the northwest
near 10 kts.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...None.
MN...None.
$$
UPDATE...JR
SHORT TERM...Godon
LONG TERM...Godon/Rick
AVIATION...JR
Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
928 PM EST Sun Jan 17 2021
.SYNOPSIS...
Another upper low will move past to the north tonight bringing a
resurgence of upslope snow showers to the North Carolina mountains
tonight and Monday. High pressure is expected to build into the
region late Monday and Tuesday, which should allow our area to
dry out and warm up above normal through mid-week. However, another
front will lay down across the region from Texas to the
Carolinas late in the week.
&&
.NEAR TERM /THROUGH MONDAY/...
As of 925 pm EST: The coverage and intensity of precipitation
continues to blossom on regional radars over the southern
Appalachians late this evening as the deep upper trough pushes east
toward the mountains. With cloud bases still 4000 to 6000 feet over
many mountain valley areas, the sub-cloud layer still has some
moistening to do to realize the better snowfall rates at the
surface, but web cams at high elevations are showing plenty of
steady snow already and the much steeper lapse rates are not far
away. PoPs have been raised to low end categorical for most mountain
locations above 3500 feet, and the current Winter Weather Advisory
appears well placed for 1 to 3 inch accumulations with some 4 to 5
inches on the highest ridge tops. There remains some concern for
isolated to scattered snow showers east of the mountains given the
pocket of 7 to 7.5 deg C/km lapse rates that crosses the region
overnight. However, the latest HRRR runs are less bullish on
coverage. Will keep isolated showers mentioned for mainly the I-40
corridor east of the mountains where the lapse rates are steepest,
and isolated rain/snow showers over the southern Piedmont where DPVA
will be best. Still anticipate some 35 to 45 mph gusts along the
higher peaks overnight and this wording is now wrapped into the
Winter Weather Advisory.
Anticipate the upslope moisture gradually waning through the morning
hours on Monday. The current cold airmass will be maintained,
however some measure of downslope warming along with good insolation
will allow highs to reach near normal levels outside the mtns Monday
afternoon. The mountain valleys will remain about 5 degrees below
normal.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
As of 200 pm Sunday: A low amplitude long wave trough will remain
over the eastern Conus through much of the short term. Within this
flow pattern, a speed max will dig into the Ohio Valley Mon night
into Tue. An attendant occluding frontal zone associated with
weakening cyclone will sag toward the forecast area by the end of
Tuesday. A lack of significant forcing and limited moisture will
yield small precip chances...at best...across the NC mountains Tue
afternoon into Tue night. Any subsequent chances for precip
associated with the front are expected to be south and east of the
forecast area through the end of the short term. Otherwise, temps
are forecast to be a little above climo through the period after a
relatively cold start Monday night.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
As of 210 pm Sunday: A transition to a flat/zonal flow pattern is
expected across much of the Conus during the medium range, with a
baroclinic zone lingering over the Southeast through much of the
period. In light of this expected transition, it is no surprise that
model guidance is struggling with the details of multiple low
amplitude short wave troughs that will likely interact with this
baroclinic zone. While this will result in some part of the
Southeast seeing a fairly active pattern, global models are showing
fairly disparate solutions and poor run-to-run consistency regarding
chances for precip across our forecast area during mid-to-late week.
As such, we`re hesitant to commit to anything more than wishy-washy
small pops, essentially from late Wed night through much of the
remainder of the period. Temps are forecast to begin the medium
range a little above normal, possibly returning to around climo by
the end of the period.
&&
.AVIATION /03Z MONDAY THROUGH FRIDAY/...
At KCLT and elsewhere: Anticipate VFR bases at the TAF sites as the
upper trough moves east over the region overnight. Ceilings will be
most likely from KAVL to KHKY, and possible at times at the other
sites. Cannot rule out a brief snow shower at KAVL and KHKY as well
as the steep upper-level lapse rates with the trough move through
the region, but confidence remains too low to mention in the TAFs
except at KAVL. Winds will be generally from the southwest to west-
southwest at sites east of the mountains, but turning more NW and
upvalley at KAVL the remainder of the period. Gusts will develop at
KAVL in the cold advection, but gusty winds will be possible east of
the mountains as well as mixing starts up late Monday morning.
Anticipate mainly just lingering FEW cumulus or high clouds Monday
after the upper wave passes.
Outlook: VFR conditions are expected Monday night through Wednesday.
Moisture and restrictions could return later in the week.
Confidence Table...
02-08Z 08-14Z 14-20Z 20-00Z
KCLT High 100% High 100% High 100% High 100%
KGSP High 100% High 100% High 100% High 100%
KAVL High 100% High 100% High 100% High 100%
KHKY High 100% High 100% High 100% High 100%
KGMU High 100% High 100% High 100% High 100%
KAND High 100% High 100% High 100% High 100%
The percentage reflects the number of guidance members agreeing
with the scheduled TAF issuance flight rule category. Complete hourly
experimental aviation forecast consistency tables are available at
the following link:
www.weather.gov/gsp/aviation
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...None.
NC...Winter Weather Advisory above 3500 feet until noon EST Monday
for NCZ033-048>052-058-059-062.
SC...None.
&&
$$
SYNOPSIS...DEO
NEAR TERM...HG/SBK
SHORT TERM...JDL
LONG TERM...JDL
AVIATION...HG
Area Forecast Discussion
National Weather Service Northern Indiana
1035 PM EST Sun Jan 17 2021
.SYNOPSIS...
Issued at 606 PM EST Sun Jan 17 2021
Light snow will continue overnight. Some minor accumulations near
Lake Michigan are expected. Slippery travel is possible late tonight
within lingering snow and with temperatures below freezing on wet
pavement. Look for more quiet weather with seasonable temperatures
through the workweek.
&&
.SHORT TERM...(This Evening through Monday)
Issued at 244 PM EST Sun Jan 17 2021
The large scale trough forcing the snow across the area digs to the
southeastern CONUS and the weakening mid level low pressure system
continues to shift to our east. The DGZ suffers some drying out and
weakening of omega this afternoon and overnight on the NAM, which
had been handling the morning precipitation the best so snow will
likely become weaker in the near term as the forcing passes by
overhead. Lows tonight fall back into the mid to upper 20s so any
wet areas could create black ice Monday morning.
Around 00z and shortly thereafter, a surface trough is modeled to
push southeast away from the lake and with a northwest wind, some
lake enhanced snow is possible this evening. It was interesting to
see that the HRRR modeled a meso low coming down the lake behind
this system, but it didn`t model the system correctly from the start
so we`ll need to take it with a grain of salt. However, with the
cooler air coming in, a relatively thick DGZ and residence time of
the column in that DGZ along with some low level theta-e lapse rate
instability and wind convergence, feel there could be some stronger
lake effect bands possible. As we approach Monday morning, a drying
out of the DGZ occurs on some soundings with some below DGZ omega
indicating riming so any lake effect snow will have a lower SLR and
it may just become more drizzle if continues sputtering into the
morning.
Less than 1 inch is expected in areas away from the lake and north
of US-30 and US-24 this evening with an additional 1 to possible
local 2 inches near the lake. The higher totals near the lake
includes totals as a result of the pivot point of the low, but also
because of some of the lake enhancement there and potentially
cooler pavement temps. Highs on Monday rise back to the low 30s.
&&
.LONG TERM...(Monday Night through Sunday)
Issued at 244 PM EST Sun Jan 17 2021
Moving forward, a southeast high pressure system and southwest
cutoff low takes hold. Meanwhile, the mid level flow looks flatter
across the eastern half of the CONUS, which helps to suppress the
low in the Tennessee Valley and pass by to our south on Tuesday
(with some model agreement to add some confidence). A second spoke
of vorticity rounds the upper low in southeast Canada to approach
our area for Tuesday night. This also has some model agreement to
work with despite timing issues and appears as a stronger low
pressure system that the one during the day time Tuesday. It`s got a
clipper-like look with a strong northern stream on its back end and
high pressure building in behind it. Sometimes these clipper systems
pack a sneaky wintry punch so it will require a continued watch as
models struggle during this pattern change. Some moisture does
appear to be able to be advected into it so that may be in its
favor.
Beyond Tuesday night, will continue with the previous dry
forecast as ridging moves in and the northern stream that
controls our weather moving forward is rather moisture starved.
Most systems in the northern stream flow pass by to our north so
we`re caught in the in-between. Temperature-wise, it`s a bit of a
roller coaster ride with a reach into the upper 30s to around 40
degrees on Thursday before highs fall back towards upper 20s on
Saturday. Lows Friday night and Saturday night fall into the upper
teens to low 20s which is more seasonable, actually, as opposed
to the mid 20s we`ve had.
&&
.AVIATION...(For the 06Z TAFS through 06Z Monday Night)
Issued at 1035 PM EST Sun Jan 17 2021
Overall trend towards slightly more optimistic with majority of
forecast period above fueling/alternate. Mesovort enhanced
snowband to track slowly southeast into KFWA early Monday morning
with tempo low end MVFR expected. Lake enhanced western edge of
mid level deformation near KSBN expected to weaken as parent mid
level circulation fills/shifts eastward into Lower Great Lakes.
Some signal for trough passage/enhanced low level convergence near
daybreak and also account for tempo low end MVFR period as well.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SYNOPSIS...Murphy
SHORT TERM...Roller
LONG TERM...Roller
AVIATION...Murphy
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Area Forecast Discussion
National Weather Service Louisville KY
748 PM EST Sun Jan 17 2021
.Forecast Update...
Issued at 747 PM EST Sun Jan 17 2021
While snow showers have diminished over the Bluegrass region this
evening, the next round of light snow is underway as moisture pushes
into the northwestern CWA. Scattered snow showers are presently
spreading east near and north of the Ohio River. A compact shortwave
trough can be seen on water vapor imagery, spinning ESE over
southern IL/IN. This feature will continue directly over the CWA
between now and 06-09z. Enhanced moisture extending up through the
DGZ is wrapping around the base of the trough and pushing east into
the area from western KY and SW Indiana. Some model guidance does
show some modestly enhanced lift aloft quickly sweeping east across
central and southern KY, so this round of light snow will include
the whole area and even extend south of the TN border. Light snow is
expected, but localized brief bursts of moderate snow are possible
over south-central KY.
Fortunately, south-central KY has road pavement temps around 40
degrees currently, but air temps have dropped off quickly in a dry
slot now pushing east of I-65. Pavement temps are hovering in the
low to mid 30s in southern IN and mid to upper 30s across the
northern half of central KY. Pavement temps will continue to slowly
fall overnight, so despite very light additional accumulation, some
travel impacts are possible tonight into early Monday.
Snow should be winding down by 09z (4 AM EST) in the eastern
forecast area. Air temps by that time will be in the upper 20s to
lower 30s, with pavement temps generally in the low to mid 30s.
Bridges and overpasses will certainly be below freezing, but some of
the cooler spots currently along I-64 in Indiana should be around
the freezing mark. Any lingering moisture from light snow
today/tonight could freeze, so motorists should be prepared for
slick spots during the morning commute.
&&
.Short Term...(This evening through Monday)
Issued at 311 PM EST Sun Jan 17 2021
An upper level low will move through the OH Valley overnight
resulting in continued chances of precipitation through Monday
morning.
Current water vapor imagery still shows the upper cyclonic
circulation located over central IL as surface trough axis extends
NE-SW through central KY between HNB and SDF. Radar continues to
show showers moving through the area, mainly north of the Parkways.
Steep low level lapse rates have resulted in more convective,
cellular showers as regional observations report a mix of p-types
ranging from all snow and rain/snow mix to short periods of graupel.
As surface temperatures begin to drop tonight, expect p-type to turn
to all snow. RAP soundings show enough saturation below 800mb for
some flurries to continue behind the main shower chances. Will also
continue to carry chance of flurries across southern Indiana and
parts of north central Kentucky into the late morning and early
afternoon Monday. Hi-res guidance does suggest a chance of some
light snow showers redeveloping again Monday afternoon as small
vorticity lobes ride out ahead of our next impulse that impacts the
area Monday night into Tuesday morning, more on that below in the
long term discussion.
Cooler air in the wake of the upper low and surface trough will see
Monday morning min temps fall below freezing across the area. Look
for lows in the mid 20s to low 30s. Have hoisted another Special
Weather Statement to cover any potential impacts overnight.
Accumulations of up to 1 inch are possible in southern Indiana, but
most locations will less than 1/2 inch on mainly grassy and elevated
surfaces. Some slick spots on bridges and overpasses may also be
possible overnight and during the Monday morning commute.
.Long Term...(Monday night through Sunday)
Issued at 250 PM EST Sun Jan 17 2021
...Minor Snow Accumulations Possible Monday Night...
Fairly low-confidence forecast, as the first half of the week is
marked by a series of disturbances swinging through a broad low-
amplitude upper trof, and then a progressive southern stream becomes
the main player later in the week.
A sheared-out Clipper will swing through the Ohio Valley on Monday
night, generating just enough isentropic lift for minor snow
accumulations along and north of the I-64 corridor. This could be a
more impactful snow than any of this weekend`s impulses as the QPF
is focused between 06-12Z Tue, close to the diurnal min in air and
sfc temperatures. Accumulations could push 1 inch in our
northernmost counties, and if forecast trends continue, later shifts
may be looking at a Winter Weather Advisory. However at this time
POPs are still in the 30-50% range, with the potential for a QPF
bust if the narrow stripe of snow is just 25-50 miles farther north,
and an impact bust if the system is slower and comes through in the
daylight.
Sfc high pressure building from the west will try to dry us out on
Tuesday, and another NW flow disturbance swings through the Great
Lakes Tue night. At this point it looks like that system will stay
far enough north to keep us dry.
A fast zonal pattern sets up in the latter half of the work week and
the southern stream becomes the main show. At this point the
pattern looks very suppressed, with most of the lift and the QPF
focused near a stationary sfc front across the Deep South. Biggest
question for our weather is just how far north any waves are able to
sling mid-level moisture. Operational models are keeping the Wed
night/Thu precip shield south of Interstate 40, but there are still
some ensemble members trying to bring precip into south-central
Kentucky. Will carry a slight chance across the board late Wed
night, and then limit any POP mention for Thursday to areas south of
the Western Kentucky and Bluegrass Parkways. Could see a brief mix
at onset, but plenty of warm advection should take us to all rain.
We`ll go dry Fri-Sat, and might even see some sunshine with
shortwave upper ridging overhead and sfc high pressure over the
Great Lakes winning the battle. Precip chances will ramp back up on
Sunday as the pattern starts to amplify and a decent Gulf moisture
feed sets up. Precip type at onset will depend on timing, but expect
it to go over to all rain. Daytime temps will run on the higher side
of normal for the latter half of the week, mitigating most p-type
concerns.
&&
.Aviation...(00Z TAF Issuance)
Issued at 655 PM EST Sun Jan 17 2021
Scattered light snow showers, mixed with graupel, continue this
evening near and just north of I-64. Drier air pushing in from the
southwest ahead of the next wave just upstream has scattered out the
MVFR clouds at BWG/SDF/LEX. A 2 hr window of VFR looks possible at
SDF/LEX, with MVFR returning at BWG by 04-05z. A compact mid-level
shortwave trough will swing ESE over the area through 03-09z
tonight. This wave brings enhanced moisture and modest lift, likely
resulting in additional light snow and flurries. This precipitation
will reach further south, getting BWG in on the activity. Brief vsby
restrictions are possible, but the snow will be fairly light in
general. Precipitation chances decrease by 09-12z, with drier
weather likely to continue through much of the daytime hours of
Monday. Some flurries could linger past sunrise north of I-64.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
IN...None.
KY...None.
&&
$$
Update...EBW
Short Term...CG
Long Term...RAS
Aviation...EBW
Area Forecast Discussion...UPDATED
National Weather Service Chicago/Romeoville, IL
906 PM CST Sun Jan 17 2021
.UPDATE...
905 PM CST
The going forecast is in solid shape. Similar to the past 48+
hours, there is a low potential for patchy freezing drizzle
between the light snow/flurry action through Monday morning.
The radar this evening continues to show areas of flurries with
transient zones of more light snow (such as out our window here
in Romeoville as of 845 PM). In northwest Indiana, the forcing for
this light snow was still associated with today`s primary short
wave as well as some lake enhancement and lake-induced
convergence. This is slowly tapering, but still some pockets of
light snow further west, likely owing to subtle lift from a
possible weak sheared wave on the backside of the broader cyclonic
mid-level flow. Satellite indicates cloud tops of -13C or so and
most reports, automated and from mPing, indicate light
snow/flurries. Aircraft soundings and the 00Z DVN sounding do show
a wee bit of spread in the temperature and dew point traces. That
hints that pockets of drizzle remain possible, and occasionally
we see an unknown precip automated report that is likely that.
But cloud bases are generally above 1,500 ft in most of northern
Illinois and southern Wisconsin, making it difficult for any
coating drizzle to manifest itself. So not expecting much of a
noteworthy threat with any of the precipitation over the next
several hours.
Further upstream observations over southeast Minnesota and far
northern Iowa do indicate some lower cloud bases and an area of
light precipitation -- primarily light snow/flurries. This is
associated with another backside sheared short wave. Will have to
watch how this angles into north central Illinois very late
tonight and possibly northeast Illinois around daybreak. Forecast
soundings from the RAP and NAM for northern Illinois do show some
weak omega during that time. This and the saturation look to be
collocated up to the -13C height, which would point toward
flurries/light snow if enough forcing can materialize this far
east-southeast.
MTF
&&
.SHORT TERM...
329 PM CST
Through Monday night...
While some of the heavier snow rates have gradually waned over the
last few hours, light snow continues to linger over much of the
region this afternoon. This will continue to be the case into the
evening hours when snow is expected to end from west to east as the
upper low/vort max over central Illinois pinwheels its way off to
the east.
It appears unlikely that any additional snow accumulations today
will exceed more than a few tenths, but depending on how much low-
level wind convergence we can muster out over the lake late this
afternoon and evening, surface-850 mb delta Ts of around 13 degrees
Celsius, equilibrium levels potentially rising to 7000-8000 ft
AGL, and the presence of 100-200 J/kg of lake-induced CAPE could
introduce some potential for lake-enhanced precipitation over
northwest Indiana. If this were to materialize, could see another
inch or so of snow falling there (mainly Porter County) before
accumulating snow ceases later this evening. Elsewhere, we`ll lose
much of the deep saturation through the dendritic growth zone as a
ribbon of drier air aloft advects in, but with just enough
saturation within the lower portion of the residual cloud ice layer,
could see us squeezing out some flurries through the overnight hours
provided that we can get enough forcing from any of the vort lobes
gyrating around the back end of the upper low. However, considering
that we saw some reports of drizzle mixing in with the snow earlier
this morning and that none of the hi-res guidance really had a
good handle on how things evolved today, we`ll have to watch for
the potential for freezing drizzle again tonight as perhaps cloud
tops may end up warmer/lower than currently progged.
Turning our attention to Monday, a shortwave disturbance over
eastern Montana will shoot southeastward towards central/southern
Illinois overnight and into tomorrow. The combination of DPVA,
favorable jet exit region dynamics, and modest isentropic upglide
look to foster the development of precipitation just out ahead of
this disturbance tomorrow afternoon and evening. However, with
the better forcing looking to stay well to our south, most, if not
all of the CWA should remain dry tomorrow. It`s not entirely out
of the realm of possibilities that the northern fringes of the
blossoming precip shield graze our far southern counties
(Livingston, Ford, Iroquois, and Benton) resulting in flurries up
to maybe a dusting of light snow, but there isn`t enough of a
signal in either ensemble or deterministic guidance at this time
that would justify a formal mention of precip in the forecast for
this.
Cloudy skies will keep our high temperatures for Monday capped in
the lower 30s. Clearing skies and cold advection behind the
aforementioned disturbance will result in Monday night being one
of our coldest nights of the year so far with low temperatures
ranging from the teens to the low 20s. However, these lows will
still generally be at or above the normal climatological minimum
temperatures for this time of year.
Ogorek
&&
.LONG TERM...
253 PM CST
Tuesday through Sunday...
The shortened work week (for some) will be relatively quiet from a
precipitation perspective, with current only chance for snow being
on Tuesday evening. Looking ahead into next weekend and early next
week, there is a chance for a more noteworthy wintry precipitation
producer.
Tuesday will feature below normal high temperatures in the 20s for
a change, along with breezy westerly winds gusting up to 25 mph.
The parent short-wave for Tuesday evening`s clipper and light snow
accumulation potential is currently way up in northern Canada
near the Arctic Circle. The wave will zip south and then southeast
with a weak surface reflection. With today`s 12z cycle, the ECMWF
has very good support from its 51-member ensemble, along with the
addition of the GFS, GEFS, and the CMC. Increased PoPs into the
chance range I-80 and north, which is the current preferred path
of the light QPF swath.
Tomorrow night`s clipper wave passing to our south was just a few
days ago modeled to affect the CWA, so certainly can`t rule out
changes of that nature with such a low amplitude feature for
Tuesday evening`s clipper. That said, barring big changes, would
expect higher than climo snow ratios around 15:1 and up to an inch
or so of snow possible. Light snow could spread into parts of
northwest/north central Illinois later Tuesday afternoon. Will
mention the potential for minor travel impacts in the text of this
afternoon`s HWO.
A much stronger clipper/hybrid will zip across the Canadian
Prairies to north of the Great Lakes Wednesday through early
Thursday. This will bring a minor warm-up, especially on
Thursday, which could be fairly mild in the 35-40F range ahead of
the cold front trailing from the aforementioned low. Westerly
breezes will pick up again ahead of and behind the front. A shot
of colder air (in the context of the mild winter thus far) will
follow for Thursday night into the weekend as expansive strong
high pressure overspreads the region. The cool and dry surface
high will set the stage for our possible winter system to close
out the weekend.
Regarding this potential for wintry precip, the general idea has
pretty solid ensemble support out on day 7, and will be associated
with energy ejecting from a trough in the southwest and low
pressure or troughing initially over the central/southern High
Plains. However, the eventual likely outcome in terms of evolution
and sensible weather impacts will remain in flux for several
days. If a stronger system occurs, may have to contend with the
potential for mixed precipitation Sunday into Sunday night, while
on the other hand a weaker wave could create an warm advection
/over-running type snow scenario, or a miss altogether if the
energy gets suppressed. For now, have a chance of snow in the
official forecast on Sunday. Stay tuned for the latest forecast
updates on this possible system. The pattern does look to remain
active into next week beyond day 7 thanks to western troughing
(-PNA pattern) amidst continued blocking in the Arctic and North
Atlantic (-AO/-NAO) and ridging near western Alaska.
Castro
&&
.AVIATION...
For the 00Z TAFs...
Synoptically-driven -SN is quickly exiting to the southeast at
TAF issuance, with intermittent MVFR visibilities lingering for
another hour or two at ORD/MDW. Ceilings will also quickly improve
to high- end MVFR and possibly VFR levels at times into the early
overnight hours amid isolated flurries or brief VFR -SHSN.
A low to mid-level wave over southern Minnesota will track
southeast into central Illinois through mid-morning Monday.
Ceilings are expected decrease into low-end MVFR (to perhaps IFR
at RFD) levels with a slight increase in -SHSN coverage. A small
chance exists for FZDZ to mix with the -SN during this time,
especially if ceilings lower further than expected. After daybreak
Monday, any remaining precip should diminish with gradually
increasing MVFR ceilings throughout the day.
Winds are expected to remain W to WNW around or under 10 knots
through the period, strongest Monday afternoon.
Kluber
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...None.
IN...None.
LM...None.
&&
$$
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AREA FORECAST DISCUSSION
National Weather Service Morristown TN
1032 PM EST Sun Jan 17 2021
.UPDATE...
EVENING UPDATE.
&&
.DISCUSSION...
Quick moving upper trough moving through the area tonight with
scattered rain and snow showers. Dry air at the surface has
limited totals for many locations this evening, but that should
become less of a mitigating factor through the night. Temperatures
across most of the lower elevations will be too high for
accumulating snow, but light accumulations of 1 to 3 inches will
be possible above 2500 feet. Otherwise forecast is on track with
minor updates for current observations.
JB
&&
.AVIATION...
00Z TAF DISCUSSION.
A system moving through the area tonight will bring another round
of light snow showers to the area with greatest coverage near TRI.
Impacts are forecast to be minimal at TAF sites with greatest snow
coverage across higher elevations. Cigs will decrease to MVFR at
TYS and TRI with improvement on Monday afternoon. Winds become
gusty Monday afternoon from 250-270 deg.
JB
&&
.PREV DISCUSSION...
/ISSUED 309 PM EST Sun Jan 17 2021/
SHORT TERM...(Tonight and Monday)...
Main story for the short term period will be chances of light
snow showers mainly across the mountains of East Tennessee,
southwest North Carolina, and portions of southwest Virginia. WV
imagery along with RAP analysis depicts a deep upper lvl low
moving into the Great Lakes this afternoon with several rounds of
vort energy rotating through the Tennessee valley. At the surface
an area of high pressure remains located across the northern Gulf
of Mexico with sw to w low level flow. Isolated to scattered -ra
or -sn showers are expected to develop across the area in response
to increasing upper lvl ascent. Highest PoP`s look to move
through the area late tonight and into Monday morning. Light
snowfall with light accumulations is especially possible across
the mountains of southwest North Carolina, the East Tennessee
mountains and portions of southwest Virginia. An SPS will remain
in place for these areas. Areas mainly above 3500 feet could see
1-3 inches of snow accumulations with a light dusting to a couple
tenths of an inch elsewhere in the higher elevations. Lows tonight
will range from 20`s in the higher terrain to low 30`s elsewhere.
On Monday the upper lvl low begins to lift toward the northeast with
weak west to southwest flow aloft. There may be enough moisture left
over for light snow flurries across extreme northeast Tennessee and
southwest Virginia and included a few hours of snow flurries after
18Z. Highs on Monday will remain cool with highs in the upper
20`s/low 30`s across the high terrain and upper 30`s to mid 40`s
elsewhere. Cloud cover looks to stick around for most areas
tomorrow and kept mostly cloudy skies in the forecast for much of
the day Monday.
Diegan
LONG TERM (Monday night through Sunday)...
The main word for the extended is uncertainty. The extended range
models have been inconsistent from day-to-day making confidence low.
This may be due to the flattening of the upper flow with most of the
period with a fast zonal flow. In this quick flow there is a battle
between the northern and southern stream and which is in control.
The main theme is from the deterministic models and GEFS/ECMWF Mean
ensembles is to pull the best chances of rain/and higher QPF farther
south into the Gulf Coast states for Thursday and Thursday night.
At the end of the extended, models show a good deal of energy
lifting out of the southwest U.S. into the mid-section of the
nation. The jet dynamics produces strong cyclogenesis over the Plain
States. A series of jet streaks will move into the Tennessee valley
next weekend increasing chances of showers. Confidence on how this
system evolves is low.
For the specifics...
For Monday night and Tuesday morning, a weak frontal boundary moves
across the region with limited moisture and dynamics. A few light
showers or sprinkles are possible but mainly dry.
For Wednesday and Wednesday night, ridging will produce dry
conditions and slight above normal temperatures.
For Thursday and Friday, jet energy moves across the Tennessee
valley and southern Appalachians. Again, models are having a
difficult time in the placement of the jet and associated dynamics.
Trend is for this forcing to be farther south into the Gulf Coast
states. Will maintain a chance of precipitation. Temperatures across
southwest Virginia/northeast Tennessee may be cold enough to support
a wintry mix initially. Again, confidence of the wintry mix is low.
For Saturday and Sunday, another stronger system may move out into
the mid-section of the nation with greater chances of showers due to
isentropic lift and jet dynamics.
DH
&&
.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN 32 47 33 52 36 / 10 10 0 10 10
Knoxville McGhee Tyson Airport, TN 33 42 31 49 34 / 30 10 0 0 10
Oak Ridge, TN 31 42 30 48 32 / 30 10 0 0 10
Tri Cities Airport, TN 29 37 26 45 29 / 50 40 0 0 10
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&
$$
AREA FORECAST DISCUSSION
National Weather Service Raleigh NC
934 PM EST Sun Jan 17 2021
.SYNOPSIS...
An upper level trough will swing across the region tonight, followed
by high pressure ridging from the Gulf Coast states northeast
through the Mid-Atlantic region through Tuesday.
&&
.NEAR TERM /THROUGH TONIGHT/...
As of 930 PM Sunday...
A shortwave will swing into the mid-Atlantic around the upper low as
it lifts northeast into Canada tonight. The surface high will remain
over the Gulf coast as a weak cold front moves into the area. The
front will largely be characterized by winds shifting to westerly
and caa. The big question will be if there will be if the column
saturates deeply enough to get precipitation to the surface as the
wave moves through. The best chances will be along and north of I-85
from west to east between 08Z and 12Z. The HRRR is the most bullish
with the moistening and generating rain/snow. The RAP also generates
some precipitation. The NAM does but to a lesser extent and the GFS
remains dry. For now have introduced a slight chance for rain during
the aforementioned time period, though should it be heavy enough
there could be some snow mixed in as well as the temperatures wet
bulb 0C. If precipitation does occur, it should exit the area by
daybreak Monday and no significant impacts are expected. However, if
there is enough moisture on the ground (which in not expected) with
temperatures falling to 32 degrees F or lower, there could be some
slick spots, especially the usual places like bridges and
overpasses.
&&
.SHORT TERM /MONDAY THROUGH MONDAY NIGHT/...
As of 235 PM Sunday...
The trough axis will kick east on Monday, yielding fast WNW flow and
more sunshine on the whole. Forecast soundings once again show some
clouds across the western Piedmont, likely resulting from mountain
wave setup and upstream moisture on the western side of the
Appalachians filtering east, with the potential for some orographic
cirrus Monday night as another lower amplitude shortwave brings a
batch of mid-level moisture across the region. Thicknesses will be
down a few meters behind the weak cold front mention above, so highs
look to be a tad cooler in the low/mid 40s west to near 50 east.
lows Monday night have the potential to reach the upper 20s and
lower 30s, with some mid 20s in the SW closer to surface high
pressure ridge axis shift across the SE US...though orographic
cirrus could end up keep some slightly warmer.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
As of 315PM Sunday...
High pressure over the Southeast US will slowly move offshore
Tuesday and the next shortwave trough will cross the area as a weak
and cold front moves in behind it. Wednesday the cold front will
exit the area bringing clear skies in the afternoon and overnight.
Temperatures will be in the 50s for most of the area with areas
closer to the VA border in the upper 40s. Lows will drop into the
low/mid 30s for most of the region with a few spots getting down in
to the upper 40s near the VA/NC border.
Some changes in model trends for the end of the week into the
weekend on how strong the next cold front will be moving into the
area. For now, a Slight Chance of PoPs for Thursday afternoon and
evening increasing to Chance PoPs in the south for overnight into
Friday morning. As the stalled front lingers over the area Friday,
overnight PoPs are kept to a Slight Chance in the southern portions
of the CWA, and clearing out by morning. High temperatures for the
weekend will be chilly with highs in the mid/upper 40s. Lows
Saturday night will be in the upper 20s with Sunday night lows in
the 30s.
&&
.AVIATION /00Z SUNDAY THROUGH FRIDAY/...
As of 700 PM Sunday...
High confidence in VFR conditions to start the TAF period. An
advancing cold front and mid-level shortwave will increase clouds
during the overnight hours. Some of the recent guidance has hinted
at a brief period of light showers as the mid-level shortwave passes
over between 08 and 13Z, primarily at GSO/INT/RDU. Have introduced a
TEMPO period for MVFR ceilings at this time. Otherwise VFR
conditions expected through the period. Southwest winds will remain
between 6 and 9 knots overnight. Criteria for LLWS remains marginal
at best, though cannot rule out a brief period between 06 and 09Z at
FAY as the low-level winds at 2000 feet approach 35 knots from the
southwest. Winds become westerly Monday afternoon, with gusts of 15-
20 knots.
Outlook: VFR conditions are expected Tuesday through Friday. A cold
front passes through Wednesday that could result in sub-VFR
conditions. However, at the moment, it is expected to be a dry
passage with only VFR ceilings.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SYNOPSIS...BLS
NEAR TERM...KC
SHORT TERM...BLS
LONG TERM...CA
AVIATION...Kren/KC