Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 01/26/17
Area Forecast Discussion
National Weather Service Albany NY
944 PM EST Wed Jan 25 2017
.SYNOPSIS...
Another approaching low pressure system will bring some
scattered light rain showers to valley areas, and a mix of light
sleet, rain and possibly freezing rain for some higher elevations
and northern areas tonight. A cold front will cross the region
Thursday with some rain showers. Colder air will follow in the wake
of the front, with some lake effect snow showers expected across
portions of the Mohawk Valley and Adirondacks Thursday night into
Friday.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
As of 930 PM, not much change to the forecast as showers
continue to remain scattered and spreading across the region.
Mesonet observations show mainly elevations above 1000 feet
where temperatures are close to freezing. Dewpoints are
increasing which is reducing the potential for freezing rain and
more rain/snow showers. As low level moist and warm advection
continues overnight, some fog may develop and mainly rain
showers late tonight. Otherwise, cloudy conditions will prevail
as mid level jet streak approaches and broad and increase
isentropic lift continues.
Prev Disc... A very weak low level ridge will translate across
the region early this evening. This may allow for some very
brief breaks in the clouds to develop, especially in valley
areas, before mid level clouds associated with increasing
isentropic lift ahead of the next system overspreads the area.
Depending on where and how long any breaks develop, sfc temps
could drop back into the lower 30s or even slightly lower,
before rising once again later tonight as more clouds and a
light south wind develop.
An area of very light precipitation currently across NW PA was
moving E/NE, in association with the aforementioned isentropic
lift. Hi-Res models such as the HRRR and RAP13 suggest the
possibility for some very light precipitation to develop between
roughly 9 and 11 PM, initially across the NE Catskills and
Mohawk Valley, the into the Capital Region, Lake George/Saratoga
region and Berkshires. Temperatures across isolated portions of
these areas could be close to freezing, and with warmer air
moving in aloft, there could be spotty freezing rain in a few
areas. Since overall coverage of any freezing rain is expected
to be limited, have issued an SPS, but no headlines at this
time. If radar trends suggest greater areal coverage of incoming
precipitation, and also sfc obs indicate colder temps, then a
short fused winter weather/freezing rain advisory may be needed
for some of the aforementioned areas. Also, some sleet/wet snow
could occur on the leading edge of the precipitation, mainly
across the southern Adirondacks and southern VT. Localized
accumulations of a coating to less than an inch could occur.
The best chance for precipitation later tonight should be mainly
across the mid Hudson Valley, and western Adirondacks, but
again, fairly light and perhaps just sprinkles.
Temperatures should fall into the lower/mid 30s this evening,
with possibly some upper 20s across portions of the southern
Adirondacks/southern VT, with temps then rising slightly after
midnight as clouds and wind increase.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/...
Thursday, a band of light rain or showers will be possible
across portions of the mid Hudson Valley, NW CT and the
Berkshires in the morning. Then, there could be a general lull
in the precip, with even some breaks in the clouds possible, esp
in valley areas from I-90 south and east.
A cold front and upper level trough will then approach from the
west in the afternoon. Isolated/scattered showers, mainly rain,
will develop just ahead of this front, and also ahead of the
upper level trough. There could be some graupel in taller
showers, along with stronger wind gusts of 30-40 mph.
In the wake of the front and trough, colder air will begin
overspread the region on gusty west winds. Some additional
spotty rain showers/sprinkles could occur in valley areas, with
snow showers across higher elevations by late afternoon. Also,
some lake effect snowbands may develop and extend into northern
Herkimer CO by late afternoon with accumulations of 1-2 inches
possible.
Temps may spike into the lower/mid 40s in valley areas late
Thursday morning, and perhaps to around or over 50 across
portions of the mid Hudson Valley in the afternoon, before
strong and deepening cold air advection allow temps to fall off
late in the afternoon.
Wind gusts behind the front could gust up to 30-40 mph at times
late Thursday afternoon.
Thursday night-Friday night, continued cold air advection and a
tightening low level pressure gradient will allow for blustery
conditions, although temps in valley areas still will not be
very cold. Lake Effect snowbands will occasionally extend into
Herkimer/western Hamilton Cos, although with several shortwave
troughs passing through, they will likely oscillate north and
south quite frequently, and may limit overall accumulations in
any one particular area. At this time, no headlines, although it
is quite possible that advisory level snowfall could occur in
at least northern Herkimer CO during the overall duration of Thu
nt-Fri nt, with localized amts of 4-6 inches or slightly higher
possible over the 30+ hour period. Elsewhere, some filaments of
Lake Effect bands may occasionally extend down portions of the
Mohawk Valley/Schoharie CO and perhaps into the Capital Region,
Berkshires and central Taconics, especially Thursday night and
Friday as cold air aloft and a multi-lake connection works in
tandem with low/mid level cyclonic flow. Localized accumulations
of a coating, to 2 inches could occur where any of these
snowbands/snow showers persist. Thu night lows will range from
the lower/mid 20s across higher elevations, to lower 30s in
valley. Highs Friday should range from the mid 20s across higher
elevations, to mid/upper 30s in valley areas. Lows Friday night
should mainly be in the 20s, with some teens possible across
the southern Adirondacks.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
A return to a more winter pattern across the northeast corridor of
the CONUS as ridge attempts to build across western North America
and trough evolves over the east. This will bring about periods of
clouds and snow showers with increasing potential for lake effect
snow developing downwind of Lake Ontario through the weekend. The
most potent wave seen in the global model consensus arrives Sunday
night into Monday timeframe. While the heart of the cold air is
forecast to remain north of local area, enough instability should
allow for more scattered snow showers and squalls downwind of Lake
Ontario.
Thereafter, a fast moving clipper is expected to approach the Great
Lakes region which will temporarily allow for downstream ridging for
late Monday into Monday night before we increase the chance for
additional snow showers toward Tuesday.
Temperatures through the long term will average near normal with the
exception Sunday into Monday with below normal values expected.
&&
.AVIATION /03Z THURSDAY THROUGH MONDAY/...
MVFR conditions will persist across the area this evening for
KALB-KGFL-KPSF with VFR conditions at KPOU. Later tonight,
MVFR to IFR conditions are expected to return as the next
system approaches. Have gone with mostly VCSH in the TAFs due to
the expected coverage of the showers but also included some
mixed precip at the onset of the event. Showers and BR may
linger through the end of the TAF period with persistent low
level moisture.
Westerly winds will shift to the southwest and south this
evening ahead of the approaching system tonight. The winds will
be brisk and gusty at KALB and KPSF much of the day with some
gusts expected at KGFL and KPOU for a period on Thursday.
Outlook...
Thursday Night: Moderate Operational Impact. Breezy Scattered SHRA...SHSN.
Friday: Moderate Operational Impact. Windy With Gusts To 33.0 Scattered SHSN.
Friday Night: Low Operational Impact. Breezy Slight Chance of SHSN.
Saturday: Slight Chance of SHSN.
Saturday Night: No Operational Impact. NO SIG WX.
Sunday: Low Operational Impact. Slight Chance of SHSN.
Sunday Night: No Operational Impact. NO SIG WX.
Monday: Slight Chance of SHSN.
&&
.HYDROLOGY...
The recent coastal storm brought widespread precipitation to the
region over the past several days, but river and streams levels
generally held steady or only rose very slowly due to much of
the precipitation being freezing or frozen. River levels will
generally hold steady over the next few days with little
precipitation expected and temperatures generally near to above
normal.
Temperatures will turn colder for Friday into the weekend. There
may be some lake effect snow showers and flurries, but this will
have little immediate impact on rivers and streams. With colder
temperatures returning, especially for the higher terrain, some
ice may start to reform or strengthen this weekend on rivers,
lakes and streams.
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...Frugis/KL
NEAR TERM...KL/BGM
SHORT TERM...KL
LONG TERM...BGM
AVIATION...BGM/JVM
HYDROLOGY...Frugis/KL
Area Forecast Discussion
National Weather Service State College PA
1050 PM EST Wed Jan 25 2017
.SYNOPSIS...
A cold front will push across the region late tonight and early
Thursday morning. Breezy and colder weather is then in store
through the end of what has been a very mild month.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
Radar shows most of the showers have dissipated as the HRRR
advertised. Regional mosaic shows new showers over southern Ohio
taking aim at SW Pa so the earlier idea of rain redeveloping
over southern areas after midnight still looks good. The showers
are forecast to move across mainly the southern half of the CWA
between about 2 and 6 am.
One last mild night in store ahead of the cold front. Overnight
lows will exhibit only about a 10 deg spread from NW to SE
(low- mid 30s north and lower 40s Southern valleys). Lows will
average about 20 degrees above normal.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/...
Some concern surrounds our far SE zones for lingering showers
(or even a few hour period of steady light rain) as a weak wave
of low pressure ripples quickly NE along the cold frontal
boundary.
Elsewhere, a transition to fairly steady-state, windy and colder
conditions will occur in the wake of the cold front with mostly
cloudy to cloudy skies dominating the weather for the rest of
the short term, and through most of the long term period as
well.
Thickening lake effect/orographically enhanced clouds and
numerous snow showers will begin to fly during the mid to late
morning hours Thursday across the Western Mtns, with sprinkle or
isolated rain showers changing to flurries and scattered snow
later in the afternoon. The snow showers will continue across
the west thur night, but taper off in number heading SE off the
Allegheny Plateau.
The real cool-down across the Central Ridge and valley region
will wait until the passage of a secondary cold front Thursday
afternoon and evening. High temps in all areas will be 8-10F
above normal.
The gusty westerly wind (30-35 kts at times) Thursday into
Friday) will lead to rather strong llvl cold advection and
greatly flatten to nearly negate the normal diurnal temp rise
across the western mtns. High temps elsewhere will be reached
during the late morning then slowly fall in the afternoon.
Expect some minor snow accumulations before the end of the day
in the NW. It might be too warm over much of the rest of the
area for any snow to stick - esp SE of KAOO-UNV-KIPT.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
A stretch of seasonably colder weather will return to Central
Pennsylvania Friday through the weekend, as the upper-air pattern
shifts from a trough in the Western U.S. to one in the Great Lakes
and Northeast. This pattern will be conducive for lake-effect snow
downwind of the Great Lakes into the Northwest Alleghenies and
Laurel Highlands, with the hardest-hit snowbelt/high terrain
areas likely picking up 6+ inches by Sunday. The long duration
of the event makes it difficult to focus on a window of opportunity
for potential lake-effect headlines, and have decided to hold
off in coordination with WFO CLE. The highest risk for heavy LES
appears to be in southwest NY in BUF CWA where LES warnings are
in effect. We will continue to highlight the LES accumulation
in the HWO. Clipper system embedded in the cyclonic flow may
expand snow accumulation to the east of the Allegheny Mountains
Sun-Mon. Global model and ensemble consensus keeps a mean trough
in the Eastern U.S. next week which should favor continuation
of typical late- January/early February cold. No major winter
storms on the horizon.
&&
.AVIATION /04Z THURSDAY THROUGH MONDAY/...
A ridge of high pressure slides east of the area overnight,
followed quickly by thickening and lower clouds with widespread
MVFR (valley) to IFR (mtns) developing in rain showers along and
ahead of a cold front.
Expect a 4-7 hour period of LLWS early tonight thanks to a
fairly strong (35-45 kt) low-level jet ahead of the cold front.
Low cigs and frequent snow showers with greatly varying flying
conditions will persist Thursday and Thursday night in the wake
of the cold front across the Western Mtns with mainly MVFR cigs
and VFR to MVFR visbys across the Central Ridge and Valley
airfields.
Winds at low levels and aloft shift more to the west-northwest
Thursday into Friday with sfc gusts between 25 and 35 kts.
Outlook...
Fri-Mon...IFR to MVFR in snow showers west. VFR-ocnl MVFR east.
&&
.EQUIPMENT...
KCCX radar will remain down at least until mid day Thursday
awaiting parts.
KFIG observation will be offline for an extended period of time
due to failed power feed to the DCP.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SYNOPSIS...La Corte
NEAR TERM...La Corte
SHORT TERM...Lambert
LONG TERM...Steinbugl
AVIATION...Lambert/Ceru
EQUIPMENT...La Corte
Area Forecast Discussion
National Weather Service Grand Rapids MI
847 PM EST Wed Jan 25 2017
LATEST UPDATE...
Update
.SYNOPSIS...
Issued at 330 PM EST Wed Jan 25 2017
We will gradually sink back into winter across all of Southwest
Michigan, as the rain switches over to snow overnight. Periods of
light snow will continue through the rest of the work week, but
accumulations are expected to remain low. Two to four inches can be
expected for areas north of Highway 20 through Friday night, while
two inches or less can be expected for areas to the south of Highway
20. High temperatures will be in the 30s for both Thursday and
Friday.
We will remain near normal temperatures this weekend and into early
next week. More occasional snow will occur, with the best chances
coming Sunday, and again Monday night and Tuesday.
&&
.UPDATE...
Issued at 848 PM EST Wed Jan 25 2017
I did a quick update to the forecast tonight into tomorrow
morning using the latest time lagged HRRR / RAP model data which
suggests slightly colder temperatures toward morning. That would
mean slightly more snow but I am thinking even if this does happen
it will only accumulate on grassy surfaces etc as soil
temperatures have been warmed by the thaw over the past week or s.
&&
.SHORT TERM...(This evening through Friday night)
Issued at 330 PM EST Wed Jan 25 2017
We will gradually change over from rain to snow from northwest to
southeast overnight. Then periods of light snow continue through
Friday night, but nothing heavy is expected.
Surface low pressure was cutting through the state late this
afternoon. As it passes to the east tonight it will drag the
deformation zone pcpn over the region and also drag in cooler air. A
transition to snow will occur, but the main surge of cooler air does
not arrive until late evening and into the wee hours of Thursday
morning. So early evening rain will still be commonplace, except
for the Highway 10 region which will have snow, with other locations
switching over between 04Z and 08Z. Since Highway 10 will be mostly
snow through the night, have a 1-3 inch accum there and generally
less than an inch elsewhere.
Deformation snow will continue into Thursday morning, but it will
gradually exit to the SE toward mid day. Temps will generally be in
the mid 30s, so not expecting much if any impacts. And additional
accums will be minimal, a half inch or less.
As we move into the Thursday night through Friday night periods,
lake effect enhancements come into play. There will also be a short
wave coming through late Thursday night/early Friday morning. So
expect light snow to continue. However heavy snow is not expected.
This will not be arctic air moving in, as H8 temps only drop to
around -11C, and even occasionally coming up to -8C, only creating
marginal lake instability. So the lake enhancement is not expected
to be all that strong, and should come in waves. Looks like a peak
will come with the short wave Friday morning when some areas will
have likely POPs. Otherwise will carry chance POPs in this time
frame. Any additional accums in these three periods will generally be
an inch or less, with localized two inches over the far SW corner of
the state.
.LONG TERM...(Saturday through Wednesday)
Issued at 330 PM EST Wed Jan 25 2017
Made some changes to Superblend in the extended. Bumped up POPs
significantly for Saturday and Sunday for lake effect snow and
lowered temperatures a degree through the period.
Snow showers should be extensive on Saturday into Sunday morning
with the passage of trough/arctic front which features a Lake
Superior connection and strong sfc convergence across the SW zones.
We could see a persistent band forming along the I-94 corridor
Saturday night into Sunday.
Lake effect snow should decrease by Monday as shortwave ridging
moves in ahead of a clipper and arctic front that arrives Tuesday
night. Any synoptic snows will be fairly light as the sfc low passes
to the north, with briefly milder temperatures late Tuesday. West
flow lake effect snow showers expected on Wednesday as arctic air
returns.
&&
.AVIATION...(For the 00Z TAFS through 00Z Thursday evening)
Issued at 639 PM EST Wed Jan 25 2017
IFR conditions in rain/drizzle and fog early tonight will turn to
IFR to LIFR conditions in the 06z to 15z time frame as a band of
snow moves west to east across the TAF sites. The back edge of
that snow band will bring conditions to MVFR so western TAF sites
could see that by 18z or so while eastern TAF sites may have to
wait till 21z to 00z for that. Winds may get gusty Thursday during
the day as the colder air comes in from the north.
&&
.MARINE...
Issued at 330 PM EST Wed Jan 25 2017
We will be going into a long duration period where conditions will
be hazardous to small craft, starting tonight. It will likely last
through at least Friday night.
North northwest winds will kick up to 20-30 knots behind the system
tonight. They will gradually go northwest Thursday, and west
Thursday night and Friday. Looks like they diminish a bit by Friday
night, but still around 20 knots.
&&
.HYDROLOGY...
Issued at 330 PM EST Wed Jan 25 2017
Relatively high river levels are continuing, including some minor
out-of-bank flooding in the central Grand River basin. This looks to
continue for at least the next 7 days at Ionia and Maple Rapids.
Recent snowmelt in the Muskegon River basin is causing Evart and
Croton to creep closer to bankfull. With rain and wet snow today, a
little runoff may encourage those river points to approach bankfull
the next couple days before they likely start to drop. Fortunately
the temperature pattern is falling back to near normal, and much of
the precipitation that falls in the next week will be snow. This
will limit runoff into rivers and help them recover to more
manageable levels.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...None.
LM...Small Craft Advisory until 7 PM EST Friday for LMZ844>849.
&&
$$
UPDATE...WDM
SYNOPSIS...JK
SHORT TERM...JK
LONG TERM...Ostuno
AVIATION...WDM
HYDROLOGY...NJJ
MARINE...JK
Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
923 PM EST Wed Jan 25 2017
.SYNOPSIS...
Mild high pressure will remain over the region before a cold front
crosses the forecast area early Thursday. At the same time, a broad
upper level trough will develop over the eastern part of the country
allowing seasonally colder temperatures to return on Friday and persist
into early next week.
&&
.NEAR TERM /THROUGH THURSDAY/...
As of 915 PM: A closed upper circulation moving east across the
Midwest this evening is extending a broad trough back through
west TX. Deep layer southwesterly flow has set up ahead of these
features across the Southeast. Deeper moisture just ahead of a
cold front over the lower MS Valley is pushing northeast to the
base of the southern Appalachians tonight. Earlier convection has
diminished over TN, but a new linear feature is present over NE
AL. SBCAPE trends from the RAP look quite limited as the moisture
band crosses our CWFA. A few rumbles of thunder cannot be ruled
out but showers look much more likely. Shallow upglide may permit
some precip generation over the Piedmont in the wee hours of the
morning regardless of whatever develops in the convergence zone.
The low level jet is still expected to peak around 40 to 50 kt.
Despite the reasonably good shear, the low level flow will not be
very backed and SHERB values will be in the unimpressive 0.6 to
0.7 range overnight. Despite the lack of significant convective
wind gusts, gradient winds may gust at times overnight.
PoPs will end quickly from the west through Thursday morning,
but then west or west-northwest upslope flow will develop into
the western NC mountains. The should be just tight enough during
the post-frontal cold advection push to send gusts to near/above
Wind Advisory levels in the northern NC mountains. Following
collaboration with WFO RNK, will post a daytime wind advisory for
the northern three zones tomorrow. Snow levels will fall quickly
across the western mountains through the later part of the day
Thursday, with light accumulations getting started at the higher
elevations. Temperatures will follow a non-diurnal trend with
the fropa, but with some midday bounce east of the mountains in
downsloping flow.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
As of 215 PM EST Wednesday: Initially a fast H5 flow aloft (nearly
zonal) will start this part of the forecast cycle. Heights will be
falling through the period, and the flow aloft gradually becoming
more cyclonic.
Meanwhile, from the surface to H85 - the flow will quickly turn
cyclonic and cold advection will commence. Outside of the North
Carolina (NC) mountains cold air cumulus should be the rule,
although downsloping may even cut that back!
However in the NC mountains, upslope snow showers should be ongoing
or starting. The trajectories do not appear ideal, but over this
period of the forecast there will probably be two enhanced periods.
These two episodic periods look to be Thursday night, and again
Friday night. In between these periods, snow showers will still be
around the NC mountains, but perhaps not as concentrated.
We kept POPS in the upper chance range, with the the highest numbers
in our northern mountains. Our accumulations are slightly above the
previous package and very close to WPC. At this juncture we did not
use the deterministic GFS or NAM. The GEFS plume data has come in
line with SREF plume information, therefore we followed such - again
while blending WPC data. We will continue to monitor.
The roller coaster ride with temperatures continues, with a downward
trend, as suggest by all thermal pattern data. There appears to be a
nice clustering in the temperature profile, and we followed the
blended suite of guide into Saturday for the specifics.
The winds should also be fresh, at least through part of period,
with some single digit wind chill in the mountains Friday night.
This is certainly a sharp change from our recent warm spell.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
As of 215 PM EST Wednesday: The extended begins Saturday night with
continued mean troughing aloft over the eastern third of the
country, with a tight northwest to westerly flow gradient aloft
around the base of the trough. As we start the period, the strongest
shortwave in the series will dive down the upstream side of the
trough. The GFS is a bit of an outlier in that it has a little
bowling ball of a shortwave across the Mid-South ahead of the
primary feature over the Upper Mississippi Valley (which is depicted
on both operational GFS and ECWMF). The Mid-South feature gets
absorbed by the more significant shortwave and the result is that on
the GFS this ends up a much stronger and wetter system. For sensible
weather impacts, an enhancement in the NWFS from the short term can
be expected as the Upper Mississippi shortwave dives toward the
southern and central Appalachians, but if the GFS ends up right (or
at least righER) some of this snow could break containment and make
it across the Piedmont (well, actually since this would be Sunday
afternoon into the evening, it would just be rain). For now have
kept pops lined up more with the mountains and foothills, with a
slight increase in highest pops over the mountains. Would not be
surprised to see a few inches of accumulation out of this event but
with current data still below advisory criteria. Winds will be
another issue to monitor with the tight gradient.
Behind the shortwave, CAA will compete with downsloping NW flow on
Monday, but the flow aloft will gradually decrease in amplitude as
we push toward the middle of the week and we should see an increase
in afternoon high temperatures, finally getting back to above
seasonal normal levels. Another round of troughiness develops across
the Great Lakes toward the very end of the period and again the GFS
is wetter than the ECMWF, with a stronger front pushing down as
well. For now, have left the forecast dry into mid-week.
&&
.AVIATION /03Z THURSDAY THROUGH MONDAY/...
At KCLT and Elsewhere: The overall expectations remain the same as
during the previous cycle. Clouds lower over the next few hrs as
prefrontal moisture band moves in from the west; deep southwesterly
flow will precede this line, with some low-end gusts continuing
at the sfc. Based on hi-res guidance, a narrow mildly convective
line will cross the Appalachians in the early morning hours,
with MVFR clouds and some showers developing out ahead of it in
the ensuing moist upglide. Expect a period of MVFR vsby during
showers. Some sites may briefly see IFR cigs, but more likely MVFR
will prevail. Winds shift to NW in the morning and remain gusty
thru the day as colder air pushes back into the region.
Outlook: A colder airmass and NW flow moisture is expected to setup
through the weekend. Chances for restrictions are low at all sites
aside from at KAVL as stratus/fog could develop in the mtn valleys.
Confidence Table...
02-08Z 08-14Z 14-20Z 20-00Z
KCLT High 100% High 82% High 100% High 100%
KGSP High 98% High 80% High 100% High 100%
KAVL High 97% Med 69% High 100% High 100%
KHKY High 100% Med 79% High 100% High 100%
KGMU High 97% High 83% High 100% High 100%
KAND High 95% High 84% 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 and ensemble forecasts
are available at the following link:
www.weather.gov/gsp/aviation
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...None.
NC...Wind Advisory from 7 AM to 7 PM EST Thursday for NCZ033-049-
050.
SC...None.
&&
$$
SYNOPSIS...JPT
NEAR TERM...HG/Wimberley
SHORT TERM...TS
LONG TERM...TDP
AVIATION...Wimberley
...Update to aviation forecast discussion...
.SHORT TERM...(This evening through Thursday)
Issued at 257 PM CST Wed Jan 25 2017
Stiff northwesterly flow behind our departing low pressure system
brought continued CAA to the region today with highs struggling to
reach the mid to upper 30s. Light snow showers over southeastern
Nebraska have been eroding as they approach the Kansas border owing
to lower RH values across the area. This trend is expected to
continue through the rest of the afternoon and evening and have
removed flurry wording from the forecast. The surface pressure
pattern will change very little through tonight and tomorrow with
only a gradual relaxation of the pressure gradient. Lowered min
temps for tonight into the upper teens NW to mid 20s SE given the
current readings in the 20s upstream in Nebraska. The lack of strong
radiational cooling tonight (given the persistent stratus deck),
coupled with continued differential CAA, could result in near
adiabatic lapse rates in the BL up to 900 mb through a large portion
of the night as hinted by both the NAM and RAP bufr soundings. This
may result in continued gusty winds through the overnight hours and
have trended winds slightly higher to account for this possibility.
Highs for tomorrow will be very similar to today with skies
gradually clearing.
.LONG TERM...(Thursday night through Wednesday)
Issued at 257 PM CST Wed Jan 25 2017
By tomorrow night the area will be under the influence of northwest
flow aloft, which will keep temperatures near normal. Over the
weekend several shortwaves will keep the main trough over the
eastern US. Each wave will reinforce the air mass in place as the
area gets clipped by the cooler temperatures over the Great Lakes.
Each wave may also bring a chance for precipitation in far northeast
KS, but moisture especially in the low levels will be a limiting
factor. Therefore the bulk of the precipitation should stay
northeast of the area. Next week the upper level ridge over the west
coast will begin to break down. This will allow the temperatures to
moderate slightly, but also allow weak fast moving waves to track
over the northern plains and upper Midwest that will send cold
fronts into the area.
&&
.AVIATION...(For the 00Z TAFS through 00Z Thursday evening)
Issued at 530 PM CST Wed Jan 25 2017
MVFR to start the forecast as low clouds continue to advect in
from the northwest. Back edge of this deck is MVFR but will take a
few hours to propagate to the east. Kept winds gusty through the
night, may need another group for tomorrow afternoon but winds in
the mixed layer are generally 20kts or less. Clouds start to break
up but will likely be on the high end of scattered for the day.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Skow
LONG TERM...Sanders
AVIATION...67