Forecast Discussions mentioning any of
"ACARS" "MDCRS" "AIRCRAFT" "TAMDAR" "AMDAR" "WVSS" received at GSD on 11/30/22
Area Forecast Discussion
National Weather Service Indianapolis IN
944 PM EST Tue Nov 29 2022
.Forecast Update...
Issued at 943 PM EST Tue Nov 29 2022
A few adjustments to the forecast with this evening`s update.
Current surface observations around the region and to the west show
wind gusts underperforming for the most part... which speaks to the
stability of the boundary layer. Latest IND ACARS sounding shows a
relatively stable boundary layer with weak lapse rates and a small
inversion around 1 km agl. Strong southwesterly low level jet around
50 kts is located right around the inversion height; however with
such a stable boundary layer, it has been a struggle to get higher
gusts over 25-30 kts down to the surface. Even post frontal,
observations from western Illinois only show max wind gusts up 40
mph. Low level instability increases post frontal as cold air
advection works to steepen lapse rates; however the low level jet is
weaker so still expecting sub wind advisory criteria winds later
tonight and into tomorrow. Lowered winds in the forecast
accordingly.
The other story this evening is the potential for strong showers and
storms with the frontal passage. Current look at radar shows a line
of showers and a few embedded storms headed for the IL/IN border.
Very little instability in the low levels combined with very dry air
aloft is preventing much intensification and upward building from
this line. Expect this line to move through the state from west to
east between 04z and 07z with the strongest cells producing wind
gusts over 40 mph. Low level stability, dry air aloft, and the fact
that the best dynamics and moisture are not aligned well has led to
convection remaining weak. More detailed information can be found in
the Mesoscale Discussion.
&&
.Mesoscale Update...
Issued at 822 PM EST Tue Nov 29 2022
Ongoing light showers across central Indiana are resulting from a
shallow convective process beneath capping EML. Latest water vapor
channel imagery shows midlevel trough and associated DCVA/forcing
still well west of the area, moving quickly eastward into Illinois
now. As this trough approaches, cooling/ascent should make
thermodynamic profiles more favorable for at least a broken line of
convection within a narrow weak instability axis immediately ahead
of the front.
So far, convection over central Illinois continues remains weak in
appearance on radar and there are some negative factors against more
robust convection: 1) dry conveyor belt and entrainment into parcels
that are only weakly buoyant to begin with, 2) deepest moisture per
CIRA layered moisture products is on the western flank of the core
of the low-level jet that is displaced eastward from frontal
forcing.
Nevertheless, strong frontogenetic circulation and steepening low-
level lapse rates as the trough approaches could support strong to
possibly isolated severe gusts from the band of shallow convection,
though confidence has decreased somewhat. Even the pre-frontal
gradient winds are underperforming relative to earlier forecasts
given the relatively stable PBL. Given trends in observational data
and the above reasoning to be skeptical of a significant increase in
convective intensity, we think mesovorticies/tornadoes are unlikely.
&&
.Short Term...(This evening through Wednesday)
Issued at 223 PM EST Tue Nov 29 2022
* Gusty gradient winds to 40 mph this afternoon
* Strong to severe storms 10PM-3AM, wind gusts to 50 mph during
frontal passage
* Much colder temperatures tomorrow.
This evening and Tonight.
Active weather is expected tonight with a frontal passage along with
gusty winds and an isolated strong to severe storm. Synoptically, a
995mb surface low is pushing through Iowa into Wisconsin with a
strong cold front stretching to the south. This cold front is
expected to pass through central Indiana between 04Z and 08Z and
will bring gusty gradient winds along with convectively strengthened
gusts.
A Wind Advisory will be in place from 00Z to 09Z to account for
these gradient winds ahead and along the front and the stronger
convective winds near the front. Finer scale details associated with
this weather event will be handled via Meso-Discussions that can be
viewed above.
Temperatures will rapidly fall behind the front with lows falling to
the mid to upper 20s by early tomorrow morning. Dry air will advect
in behind the front and allow for clouds to clear out around sunrise
tomorrow.
Tuesday.
Winds will remain strong through the day tomorrow in the aftermath
of the frontal passage. Strong CAA will keep temperatures near
steady even with the relatively abundant sunshine. There will be
some lake enhanced clouds over the far northern and northeastern
counties by late afternoon which will further help to limit the
temperature rise.
&&
.Long Term...(Wednesday night through Tuesday)
Issued at 223 PM EST Tue Nov 29 2022
Ridging will build aloft within a modest zone of NVA. Ensemble
members are in a reasonable agreement this ridge will remain rather
broad over the next several days. In the low levels, conditions will
be much more variable however, with a succession of weak short
waves. The first short wave looks to arrive late on Friday. With
ridging aloft, the moisture profile will most likely be shallow,
limiting the rainfall efficiency, but a few tenths of QPF is
possible. More robust moisture return is expected within a secondary
wave Sunday, leading to higher chances for precipitation. There is
still some uncertainty on where the short wave will track through
the Midwest and Ohio Valley, but most solutions are producing some
QPF over central Indiana during the afternoon and evening on Sunday.
Temperatures will vary throughout the week, beginning on the cool
side Thursday. This will slowly increase Friday and low level winds
shift to out of the SW/S. Expect highs on Friday to be above normal;
between 50-55. The weekend will see two swings. Initially,
temperatures will drop in the wake of the 1st wave, with highs in
the low to mid 40s before quickly rebounding Sunday night into
Monday. Monday`s highs should return to the low 50s.
&&
.Aviation...(00Z TAF Issuance)
Issued at 645 PM EST Tue Nov 29 2022
Impacts:
* MVFR cigs through the overnight hours with brief MVFR to IFR
visibility during storms
* Southerly wind gusts to 35kts becoming westerly after frontal
passage 04-06z
* Low level wind shear through around 04-06z
Discussion:
Potent frontal system approaching Indiana from the west with a
strong low level jet just above the surface will pose a threat to
aviation through the overnight hours.
Winds: Southerly winds between 160-180 degrees this evening will
gradually veer to 200-220 by around 04-06z... just ahead of the
approaching cold front. 23z IND ACARS soundings shows a strong low
level jet to around 50 kts coming out of the southwest across the
region, resulting in wind shear at the TAF sites. Winds turn rapidly
with height from 160 at the surface to near 200 degrees at 2kft,
therefore keeping wind shear in the TAFs through the overnight
hours. Frontal passage and a sharp wind shift to the west (260-280)
should occur from west to east around 04-06z. LLWS should be less of
an issue after FROPA as the low level jet moves off to the east and
winds within the lowest 2kft will be out of the same direction and
at similar speeds. Elevated westerly winds with gusts to 30 kts are
still expected through much of the day tomorrow with a tight
pressure gradient and a well mixed boundary layer.
Ceilings and Vis: Expect ceilings to continue falling from VFR to
MVFR as the front approaches this evening. Brief periods of IFR
ceilings and visibility expected under heavier showers and storms,
especially as the front passes through around 04-06z. Expect
ceilings to improve behind the front rising from MVFR to VFR by
sunrise. Brief periods of lower visibility expected during showers
and storms; however for most of the evening visibility should stay
up outside of convection.
Precipitation/storms: A few lightning strikes have been observed
with storms along the main front in Illinois this evening. Best
chance for thunderstorms at any of the TAF sites will be between 04-
06z tonight. Do not expect excessive lightning with storms as CAPE
and instability is very low; however confidence in thunderstorms is
high enough during the frontal passage to include it in the TAFs.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
Wind Advisory until 4 AM EST Wednesday for INZ021-028>031-
035>049-051>057-060>065-067>072.
&&
$$
Mesoscale...BRB
Update...CM
Short Term...White
Long Term...Updike
Aviation...CM
Forecast Discussion: Over the long term, battle continues between
Gulf ridge and cold intrusions out of Canada. Upper trough moves
across the northern U.S. Friday through Sunday. Next trough drops a
bit deeper into the Plains and Great Lakes early next week.
High pressure settles over the area Thursday with below normal
nighttime temperatures expected Wednesday night and Thursday night.
The first trough spins up a strong surface low over the Plains
Friday and drives it northeast into the Canadian maritimes through
the weekend. That will push a weak cold front through here Saturday
morning. Gusty winds and some rain is likely with the front Friday
night and Saturday. Southwest flow will drive moist air and above
into the area Monday. This will set the stage for what could be a
couple day rainfall event as a warm front sets up nearby starting
Sunday and continuing into the early next week. Another cold front
moves through the area later Tuesday with colder air/below normal
temperatures behind it.
&&
.Aviation...(00Z TAF Issuance)
Issued at 639 PM EST Tue Nov 29 2022
IMPACTS:
-Gusty winds through tonight, including LLWS roughly WS020/19050KT
-Widespread showers and storms this evening into the overnight
-MVFR ceilings/visibility at times; possible IFR in strongest storms
DISCUSSION:
Low pressure system still on track to impact area terminals with
gusty southerly winds, thunderstorms, and MVFR ceilings and
visibility this evening into the overnight hours. IFR conditions
are also possible in the strongest of storms. Low level wind shear
will also be an impact around 2K feet from the south around
40-50kts, ending by 6z. By daybreak, VFR conditions should return
as the front passes by late Wednesday morning with skies clearing
and WNW winds through Wednesday evening.
CONFIDENCE:
Medium on all elements.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
IN...None.
KY...None.
&&
$$
Mesoscale...RAS
Short Term...CG
Long Term...KJF
Aviation...MK
Area Forecast Discussion
National Weather Service Midland/Odessa TX
520 PM CST Tue Nov 29 2022
...New AVIATION...
.SHORT TERM...
(This afternoon through Wednesday night)
Issued at 204 PM CST Tue Nov 29 2022
500mb RAP initialization shows the upper trough centered across
Colorado this afternoon. Its associated jet max passing overhead
is contributing to a very windy day across the region. The
strongest winds remain out west across the Guadalupe and Davis
Mountains where a High Wind Warning remains in effect through late
this evening. Strong winds have found their way into the Permian
Basin as well, prompting an expansion of the Wind Advisory through
north-central Lea County and the northwestern Permian Basin. As
the jet max departs and diurnal mixing subsides after sunset,
winds will come back down to more modest levels.
After a mild day with high temperatures reaching the mid 70s for
most thanks to downsloping westerly winds, high pressure building
southeastward through the central Plains will push a cold front
through overnight. Temperatures will tumble back below freezing
north of I-20 with lows in the 30s and 40s to the south. High
temperatures tomorrow will be 10-15 degrees below average behind
the front with east-northeasterly winds, topping out in the 40s
north of I-20 and the 50s and 60s to the south. Northerly flow
behind the front will be short lived as the high pressure center
moves into the Mississippi Valley and southeasterly winds return
Wednesday night. Lows will be a little bit warmer as a result,
with freezing temperatures limited to the far northern zones and
the higher elevations.
-Munyan
&&
.LONG TERM...
(Thursday through Monday)
Issued at 204 PM CST Tue Nov 29 2022
Zonal flow is expected across the United States through at least
early next week. This westerly flow will favor warm, downsloping
winds keeping temperatures near to above normal. A series of upper
level troughs will develop and move east within the flow but will
remain well north of our CWA. Normally this means little chance
for rainfall, however the arrival of a cold front on Saturday will
coincide with Pacific moisture and a strengthening jet stream to
give a chance of rain from southeastern New Mexico to the Permian
Basin. Rain chances will continue into Saturday night before drier
air arrives Sunday.
&&
.AVIATION...
(00Z TAFS)
Issued at 502 PM CST Tue Nov 29 2022
Winds across the plains are starting to decrease and by 01Z should
be below 12kts at all TAF sites. Cold front still n of LBB as is
generally expected to be HOB/MAF 04Z-05Z, INK about 06Z. By 12Z
winds will light, then e-se Wed. Low-level water imagery shows
wave action across/downstream of mtns as such light low flying
aircraft can expect severe turbulence INVOF mtns into the evening.
&&
.PRELIMINARY POINT TEMPS/POPS...
Big Spring 73 31 50 36 / 0 0 0 0
Carlsbad 70 32 49 32 / 0 0 0 0
Dryden 81 39 56 39 / 0 0 0 0
Fort Stockton 76 35 56 38 / 0 0 0 0
Guadalupe Pass 62 34 47 34 / 0 0 0 0
Hobbs 66 27 48 32 / 0 0 0 0
Marfa 69 31 60 30 / 0 0 0 0
Midland Intl Airport 73 31 51 37 / 0 0 0 0
Odessa 72 32 51 37 / 0 0 0 0
Wink 73 31 52 36 / 0 0 0 0
&&
.MAF WATCHES/WARNINGS/ADVISORIES...
TX...High Wind Warning until 10 PM CST /9 PM MST/ this evening for
Guadalupe Mountains Above 7000 Feet-Guadalupe and Delaware
Mountains.
Wind Advisory until 7 PM CST this evening for Davis Mountains
Foothills-Eastern Culberson County.
High Wind Warning until 7 PM CST this evening for Davis
Mountains.
NM...High Wind Warning until 9 PM MST this evening for Guadalupe
Mountains of Eddy County.
Wind Advisory until 6 PM MST this evening for Eddy County Plains.
&&
$$
Area Forecast Discussion
National Weather Service Raleigh NC
1039 PM EST Tue Nov 29 2022
.SYNOPSIS...
A warm front will lift northward into the area tonight, followed by
a cold frontal passage from west to east on Wednesday. Cool high
pressure will build in from the west Wednesday night through Friday.
&&
.NEAR TERM /THROUGH 7 AM WEDNESDAY/...
As of 1030 PM Tuesday...
A closed mid-level low is currently centered over SE Manitoba, with
the associated trough digging over the Plains. This trough will push
east into the MS Valley by tomorrow morning as the closed low
becomes centered near Lake Superior. At the surface, a 990 mb low
centered over Lake Superior will continue to deepen and lift north
into Ontario tonight. As it does so, it will drag a strong cold
front that currently extends south from Lake Michigan into the lower
MS Valley east into the central and southern Appalachians by
tomorrow morning. Increasing southwesterly flow aloft from the
approaching trough combined with a mid-level disturbance is
resulting in an area of widespread showers across eastern TN,
western NC, and northern GA, with enough instability for storms
across MS and AL. Thanks to the departing subtropical ridge, the
environment is still very dry across central NC this evening, as dew
points are only in the 40s in most places and PW values are around
half an inch.
However, the atmospheric column will quickly moisten overnight as
southwesterly flow aloft advects PW values of 1.25" to as much as
1.50" into central NC by 12z Wednesday. This is about 150-175% of
normal. As a result, a deck of mid and high level clouds is already
beginning to stream into the region, and these clouds will gradually
thicken and lower, with all of central NC becoming overcast over the
next few hours. The area of showers to our west will also begin to
move into the NW Piedmont after midnight, reaching the US-1 corridor
by around 12z. Given the high PW values, the rain could be heavy at
times, making for a messy morning commute in the Triad and possibly
as far east as the Triangle if it gets there quickly enough. The
wind fields will also be impressive with mid-level flow as high as
60-70 kts by early tomorrow morning. But given the time of day and
dew points still only in the upper-40s to lower-50s, instability
will be lacking and any real MUCAPE will stay to our southwest. So
not expecting any thunder overnight. Due to the increasing cloud
cover, low temperatures will be about 10-15 degrees above normal
(mid-40s to lower-50s) and likely occur around midnight before
slowly increasing through the night.
&&
.SHORT TERM /7 AM WEDNESDAY THROUGH WEDNESDAY NIGHT/...
As of 245 PM Tuesday...
Rain will spread across most of central NC Wednesday morning as the
upper trough swings by to our north and a cold front begins to move
east across the TN/NC border. The severe threat has diminished over
the past day, and SPC only has most of our area now in general
thunder. 0-1 km shear of 30-40 kt may help organize some stronger
storms, which could generate heavy rain and some lightning across
areas south of the Triangle and Triad where dewpoints flirt with 60
degrees. The main wave of rain will quickly exit east by early
afternoon, then a small line of showers may develop along the cold
front as it digs across the region in the afternoon. Additionally,
southwesterly winds will become breezy ahead of the cold front, with
gusts of 25-35 mph possible through the afternoon and diminishing
through the evening. Highs will be in the 60s, with a few areas near
70 possible close to the SC border.
Skies will quickly clear behind the front Wednesday evening, and
cold and dry air advection will be in full effect throughout the
night. Dewpoints will drop from the 50s and 60s down to the 20s by
late Wednesday night as a cold surface high builds from the Mid-
Mississippi River Valley to the Mid-Atlantic. Overnight lows will
dip into the 30s, with a few of the usual cold spots lowering to the
upper 20s.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
As of 235 PM Tuesday...
The long term period will begin with a benign pattern of an exiting
upper level trough across the Northeastern U.S. early Thursday
combined with a ridge across the Gulf of Mexico resulting in a west
and southwesterly flow aloft across the Carolinas. Mainly clear
skies across are expected on Thursday with below normal temperatures
and highs between 48 and 56. It will be chilly with lows in the mid
20s to around 30 on Friday morning. Increasing clouds are expected
on Friday and especially Friday night as an upper trough moves into
the Great Lakes. Slightly milder highs, mainly in the mid to upper
50s, are expected on Friday. Lows will be moderated by clouds and
a stirring wind and range in the lower to mid 40s.
An active jet associated with a broadening upper level trough that
shifts east with time will extend from the southern Plains into the
northeast. Central NC will be on the eastern periphery of this
feature with more impactful weather located to the north and west. A
modest cold front will move across central NC late Saturday with
limited moisture and rain chances. Dry weather is expected on Sunday
with another chance of showers late Monday, most favored across the
northwest, as a warm front lifts north across the area. Dry weather
should follow on Tuesday before another modest cold front approaches
late Tuesday night into Wednesday. Near normal highs on Sunday in
the mid 50s to around 60 will warm above normal on Monday and
especially Tuesday when highs will range in the mid 60s to around 70
if not a little warmer. -Blaes
&&
.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
As of 655 PM Tuesday...
Current VFR conditions across central NC will give way to worsening
conditions down to IFR from west to east starting tonight,
associated with an approaching front preceded by a solid band of
showers and isolated embedded storms. Mid and high clouds will
increase and thicken this evening from W to E with steadily lowering
bases. INT/GSO are then expected to drop to IFR by 08z; RDU by 11z;
and FAY/RWI by 13z Wed, with the onset of showers with MVFR/IFR
vsbys and IFR cigs (and a period of LIFR cigs is possible). Rain
will taper down W to E in the afternoon (by 17z W terminals and by
21z E terminals), but IFR to MVFR cigs will linger, trending to VFR
after 21z at INT/GSO but staying sub-VFR in the E terminals through
the end of the TAF valid period. Surface winds will be mostly light
through tonight from the E or SE under 10 kts, and while low level
wind shear is not likely late tonight, the presence of increasing
winds aloft from the S to around 20-25 kts after 09z tonight may
cause difficulty with aircraft handling. Surface winds will then
increase from the S and SW after 12z at 10-15 kts with gusts to 18-
24 kts expected through the afternoon.
Looking beyond 00z Thu, VFR conditions are expected to return to
eastern terminals by 03z Thu. These VFR conditions will dominate
areawide through Fri. The next chance for rain and sub-VFR
conditions will be Fri night through Sat night, as another front
moves through. High pressure and VFR conditions should return for
Sunday, although confidence in the details is low. -GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SYNOPSIS...Danco/Hartfield
NEAR TERM...Danco
SHORT TERM...JJT
LONG TERM...Blaes
AVIATION...Hartfield