Forecast Discussions mentioning any of
"ACARS" "MDCRS" "AIRCRAFT" "TAMDAR" "AMDAR" "WVSS" received at GSD on 12/16/21
Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
819 PM CST Wed Dec 15 2021
.UPDATE...
Issued at 819 PM CST Wed Dec 15 2021
Will be expanding the high wind warning to encompass remainder of
the CWA.
Quick update on latest thinking regarding synoptic damaging winds
and potential for convective damaging winds this evening.
Convective Threat:
Recent satellite and radar trends show a distinctive lessening in
the intensity of the convective line from southern IA south into
MO. Have seen the convection transition from more of instability
fed, beefy deep moist convective look on radar to that of more of
a thin strongly forced low topped line of convection. The 00z DVN
sounding has a very similar look to the 19z OMA sounding with an
extremely sharp and strong (~7C) capping inversion near 850mb.
Very strong synoptic ascent associated with the deepening cyclone
lifted through that capping inversion over eastern NE/western IA
early this afternoon, allowing for the intense convection. The
stronger synoptic ascent is lifting northeast, leaving our area
with far weaker ascent and a more pronounced cap/less instability
(warmer mid level temps). This strongly forced line of convection
should continue to encounter very gradually more hostile
conditions, so would anticipate at least a slow weakening trend
over the next several hours as it moves toward and into northern
Illinois. It is plausible that the fairly solid line to begin to
break up with gaps as it weakens and potentially dissipate or
nearly dissipate altogether by the time it reaches Chicago and the
eastern portions of our CWA.
The complicating factor is the ambient environmental winds are
already very strong and will continue to strengthen this evening.
Given the very strong flow just above the surface, it wouldn`t
take much even weakening convection void of lightning to
potentially transport severe criteria winds to the surface. This
has been well handled with our forecast and messaging thus far and
not planning any changes to the forecast/massaging for this part
of the forecast. Will continue to monitor radar and satellite
trends and as storm coverage decreases, will low pops accordingly
in the the grids, but for now not planning any changes.
Non-convective Damaging Wind Threat:
ACARS soundings over the past couple of hours have shown a subtle,
but important very near surface inversion, literally withing just
a couple hundred feet of the surface. The inversion is not strong,
sfc temps only about 1-1.5C from being dry adiabatic down the sfc.
Above this subtle inversion, ACARS soundings show winds already
up to 50-55kt within that mixed layer. The subtle near sfc
inversion has been preventing full and effective mixing of the
50kt+ winds just off the deck to the surface...so far.
Some important changes are expected to take place this evening.
First, forecast guidance is in good agreement in showing 0.5km
(~1500ft) AGL winds increasing to >60kt over the next couple few
hours as we see a nocturnal strengthening of the already very
powerful synoptic low level jet. Surface temps should remain
nearly steady through the evening, perhaps even inching up a
degree or so as the sfc thermal ridge in advance of the cold
front spreads east into northern IL. It is unclear if we will be
able to fully eradicate the subtle near surface inversion via
temps inching up and some slight cooling aloft due to some
increasing synoptic ascent.
Assuming the weak near sfc inversion persists and remains weak,
would still anticipate at least occasional transfers of the higher
momentum air just off the surface to the ground in gusts. This
should allow for at least occasional/sporadic gusts to 50kt+
developing in the next hour or two. Should the near surface
inversion weaken more due to slight cooling aloft or sfc warming,
then 50kt+ gusts could become fairly common with 60kt gusts even
possible. At this point, feel confident that at least sporadic
50kt+ gusts will occur with potential for a couple hours of fairly
sustained 50-60kt gusts possible late this evening. Low level jet
and stability are not forecast to be any less favorable in my
southern CWA as my northern CWA. Given SPI has already gusted to
49kt before the LLJ has fully ramped up, planning to expand the
high wind warning to cover the remainder of our CWA. It is highly
likely the high wind warning will be able to be cancelled prior to
the 15z expiration time, but not comfortable making changes to the
end time just prior to the event starting.
Updated products will be issued shortly.
- Izzi
&&
.SHORT TERM...
Issued at 300 PM CST Wed Dec 15 2021
Through Thursday...
* Damaging non-thunderstorm winds tonight into early
Thursday morning, when a High Wind Warning is in effect for
generally north of I-80, while an Advisory roughly along/south
of there. The peak winds look to be between 8 PM and 3 AM.
* Sandwiched within that high wind time will be a line of rapidly
moving convective showers and a few thunderstorms crossing
northern Illinois late this evening and gradually fading in
intensity during the overnight.
* The showers/thunderstorms may act to briefly further increase wind
gusts as they pass.
No major changes in forecast thinking and no changes to current
wind related advisories/warnings at this time. Deepening surface
low currently over central Nebraska continues to track
northeastward with the pressure gradient intensifying across the
Plains and Mississippi River Valley. The local area remains under
stratus cloud cover with gusty southerly winds continuing to
steadily increase. Temps have warmed into the 60s.
As far as winds, speeds continue to gradually increase with gusts into
the 30-40 mph range so far this afternoon. Winds will further
ratchet up this evening and continue into the overnight as the low
advances into southwestern MN and associated low level jet
rapidly increases overhead. The increased pressure gradient and
intensifying low level jet will bring 60 or so mph gusts to the
high wind warning area and speeds into the 50-55 mph range in the
advisory area. Gusts much above those values would likely need to
be tied to the expected broken/weakening line of showers and
thunderstorms that still looks to reach the I-39 corridor in the
approximate 10 or 11 pm time frame and in the approximate 11 pm to
midnight time from for the Chicago and I-55/57 corridors and just
after that across northwest Indiana. However, the intensity and
organization of the activity should be decreasing as it tracks
east. With ambient wind speeds at around 2000 ft above the ground
in the 70-75 or so mph range, thanks to the low level jet, gusts
into this range could reach the surface for a short time as the
showers/storms pass. The greatest threat for this will be across
areas generally west of Interstate 55 where better
coverage/intensity is likely, while the threat may become more
sporadic or even fade out to the east. Note that we will issue
severe thunderstorm warnings should these showers/storms generate
wind gusts meeting severe thunderstorm warning criteria even
though there is a high wind warning in effect for parts of the
area. Winds will begin to ease late tonight behind the front but
still remain gusty.
Temperatures will remain quite mild through the evening until a
cold front passes tonight, but even then the coldest lows, which
will be across north central IL, will remain above freezing. Temps
will rise a few degrees through the day Thursday northwest while
they fall from the lower 50s into the 40s southeast as colder air
spreads in. Winds will remain breezy through the day but ease
through the afternoon as high pressure moves into Missouri and the
strong surface low moves across central/eastern Ontario.
MDB
&&
.LONG TERM...
Issued at 308 PM CST Wed Dec 15 2021
Friday through Wednesday...
The long term period looks relatively quiet with seasonable
temperatures (highs in the 30s to lower 40s, lows in the 20s to
lower 30s), light winds, and occasional periods of cloud cover.
The next best chance of precipitation will be Friday night into
Saturday morning mainly southeast of I-55 as a wave rides along a
stalled frontal boundary well to our southeast. Depending on the
timing of the wave and overlap with nighttime cooling, a gradient in
precipitation type from snow along the northwest fringe to a wintry
mix and eventually plain rain to the southeast within the
precipitation shield will be fair game, though confidence in
pinpointing where each transition zone will line up (as well as how
far northwest precip extends into our area) is fairly low at this
time. Otherwise, precipitation chances through at least the middle
of next week appear slim with surface ridging parked over our area.
Borchardt/Petr
&&
.CLIMATE...
Temperatures this evening are likely to remain steady or possibly
even rise a degree or two ahead of the cold front. The cold front
should still be just west of Rockford at midnight and at least a
couple hours west of Chicago, putting the record high temperatures
for Thursday, December 16th in jeopardy at midnight, particularly
for Chicago. The current records for December 16 are:
Rockford...
Forecast Midnight High: 61 Current record high: 58 (1984)
Chicago
Forecast Midnight High: 60 Current record high: 60 (1984)
Finally, the all-time record latest snowfall at Chicago is
December 20, 2012. Unless 0.1" or more of snow falls Saturday
morning (currently appears unlikely), we appear poised to break
the record. We may also go through all of astronomical fall
without measurable snowfall at Chicago...an incredible feat.
NWS Chicago
&&
.AVIATION...
For the 00Z TAFs...
Issued at 551 PM CST Wed Dec 15 2021
The concerns include:
* Strong south to southwest winds gusting up to 35-45 kt through
tonight (direction 180-200 deg early evening)
* Period of stronger wind gusts up to 50-55 kt possible/probable
later tonight (~04z-08z), including gusts associated with a line
of SHRA
* Lower MVFR CIGs likely improving behind SHRA/cold front passage
* LLWS through the early overnight
The high impact period for aviation will peak tonight as deepening
low pressure tracks from near OMA this evening to north of Lake
Superior by 12z. Strong south to south-southwest winds will frequently
gust up to 30-35 kt (sporadic up to ~40 kt) early this evening and
then further increase in the mid to late evening when prevailing
gusts up to 45-48 kts will be common ahead of the system`s powerful
cold front. A fast moving line of showers left over from the severe
storms well to the west may be able to mix down 50-55 kt or higher
gusts from the southwest. Even outside of SHRA in the late evening-
early overnight timeframe, temporary 50-55 kt gusts are certainly
possible. Maintained going TEMPO groups and LLWS mention as well
with 60-70 kt at FL020.
Behind the cold front, should see lower MVFR CIGs improve with
40-45 kt SW gusts until pre-dawn hours, easing to mid 30s through
the morning and then around 30 kt from the west early-mid afternoon.
Forecast soundings appear well mixed enough that 20-25 kt gusts
should continue into or through Thursday evening, especially at
ORD and MDW.
Castro
&&
.MARINE...
Issued at 306 PM CST Wed Dec 15 2021
Rapidly deepening low pressure will track from the central Plains
to western Lake Superior late tonight. The strength and deepening
of this low will promote widespread strong winds in the Great
Lakes, and confidence is high in at least an upper end gale
tonight preceded by 30 to 35 kt gusts yest this afternoon. A
period within the gale of southerly to southwesterly storm force
gusts to 50 kt is expected tonight for especially the western
nearshores of Lake Michigan. Some storm force gusts may be reached
on the Indiana nearshore as well throughout the high end gale.
Winds will turn more westerly Thursday behind a morning cold
frontal passage. Gusts are still likely to be gale force later
Thursday morning and even into the early afternoon before further
easing.
While most of the wind direction through this event is offshore in
the Illinois and Indiana nearshore, the sustained speeds are high
enough to rapidly build wind-driven waves that will be slow to
ease throughout Thursday.
MDB/MTF
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...High Wind Warning...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-
ILZ011-ILZ012-ILZ013-ILZ019-ILZ020-ILZ103-ILZ104 until 9 AM
Thursday.
Wind Advisory...ILZ021-ILZ023-ILZ032-ILZ033-ILZ039-ILZ105-ILZ106-
ILZ107-ILZ108 until 9 AM Thursday.
IN...Wind Advisory...INZ001-INZ002-INZ010-INZ011-INZ019 until 9 AM
Thursday.
LM...Storm Warning...IL nearshore waters until 9 AM Thursday.
Gale Warning...IN nearshore waters until 3 PM Thursday.
&&
$$
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Area Forecast Discussion...UPDATED
National Weather Service Midland/Odessa TX
637 PM CST Wed Dec 15 2021
...New UPDATE...
.UPDATE...
Issued at 626 PM CST Wed Dec 15 2021
Winds have come down considerably in the past few hours across
portions of SE New Mexico and the Davis Mountains, thus we have
allowed the Wind Advisories to expire. However, wind gusts will
continue to stay elevated for the next few hours across the
Guadalupe & Delaware Mountains and adjacent plains in
Eddy/Culberson counties. A High Wind Warning remains in effect for
these locations thru 0500z.
-Munyan
&&
.AVIATION...
(00Z TAFS)
Issued at 508 PM CST Wed Dec 15 2021
Extensive cloud cover has limited mixing down of the stronger wind
aloft at most TAF sites except CNM. A High Wind Warning remains in
effect this evening for the Guadalupe and Delaware Mountains as
well as Eddy County and Eastern Culberson County... low flying
aircraft should avoid flying near the Guadalupe Mountains due to
severe turbulence. Pacific front moving across the area this
evening will shift the wind around to the West.
&&
.SHORT TERM...
(This afternoon through Thursday night)
Issued at 230 PM CST Wed Dec 15 2021
A potent 50-55 kt 700 hpa jet assocd with a deep mid lvl cyclone
over the Central Plains is raking northwest portions of our CWA this
afternoon. Abundant mid-high clouds have delayed the onset of
strong winds at GDP by a few hrs and kept our temperatures cooler
overall. However, these clouds are now clearing from NW-SE across
Eddy County. The windiest location so far today has been Artesia
where a 73 mph gust was recorded earlier! The Wind Advisory was
upgraded to a High Wind Warning for the Eddy County and eastern
Culberson County plains. Other locations in Lea County are now
approaching Wind Advisory criteria. Several gravity waves are
evident on latest IR satellite imagery over the Sacramento and
Guadalupe Mountains which is indicative of severe turbulence aloft.
The windy to very windy conditions will continue through this
evening and will quickly subside across the plains around sunset
as the boundary layer decouples. Strong winds could linger for
a few hrs post sunset across the Guadalupe and Delaware Mountains
where a mountain wave signature is still evident until 03Z or so.
A weak cold front will drop into the area tonight, however
high clouds and late arrival of dry air promote above normal lows
across central and eastern portions of the CWA. Tomorrow will be
much calmer and high temperatures will remain above normal as
return flow commences.
&&
.LONG TERM...
(Friday through Tuesday)
Issued at 230 PM CST Wed Dec 15 2021
On Friday an upper trough extending from Alberta down through ID
will curve back through Srn NV and CA. The northern portion of this
trough will move east crossing the Rockies onto the plains late
Friday while the southern portion remains back to the west forming a
cut off low Saturday. This low will wobble around before rolling
east across the area early Monday.
Temperatures will still be unseasonably warm Friday with most of the
region in the 70s but a fairly strong cold front will blow through
Friday night with highs Saturday mainly in the 50s. Lows Sunday
morning will be cold with many locations reaching or falling below
freezing and should only warm into the 40s during the afternoon.
After another cold morning Monday morning temps will warm will warm
into the 60s that afternoon. Highs in the 70s return Wednesday.
Will have a chance of precipitation Saturday and Sunday ahead of the
cut off low although believe models are overdoing it. Saturday
night will have a rain/snow mix possible for the higher elevations
from the Guadalupe mountains down to the Davis Mountains and Marfa
Plateau.
&&
.PRELIMINARY POINT TEMPS/POPS...
Big Spring 44 72 50 71 / 0 0 0 0
Carlsbad 39 68 39 70 / 0 0 0 0
Dryden 52 75 56 76 / 0 0 0 0
Fort Stockton 47 74 50 75 / 0 0 0 0
Guadalupe Pass 41 62 45 65 / 0 0 0 0
Hobbs 37 66 41 68 / 0 0 0 0
Marfa 34 72 36 70 / 0 0 0 0
Midland Intl Airport 43 72 50 72 / 0 0 0 0
Odessa 44 72 50 72 / 0 0 0 0
Wink 38 72 41 74 / 0 0 0 0
&&
.MAF WATCHES/WARNINGS/ADVISORIES...
TX...High Wind Warning until 11 PM CST /10 PM MST/ this evening for
Eastern Culberson County-Guadalupe Mountains Above 7000
Feet-Guadalupe and Delaware Mountains.
NM...High Wind Warning until 10 PM MST this evening for Eddy County
Plains-Guadalupe Mountains of Eddy County.
&&
$$
SHORT TERM...24
LONG TERM....72
AVIATION...24