Forecast Discussions mentioning any of
"ACARS" "MDCRS" "AIRCRAFT" "TAMDAR" "AMDAR" "WVSS" received at GSD on 04/23/22
Area Forecast Discussion
National Weather Service Lubbock TX
700 PM CDT Fri Apr 22 2022
.AVIATION...
Isolated thunderstorm development has been occurring west of I-27
early this evening. These thunderstorms have been struggling to
develop so far however thunderstorm development remains possible
through roughly 10 pm. Confidence in this activity impacting
KLBB/KPVW remain too low to include a mention at this time.
Outside of convection, southerly winds will remain gusty through
much of the overnight. These strong winds are leading to blowing
dust reducing the visibility at both KLBB and KPVW and this is
expected to continue after sunset. Winds will gradually diminish
early Saturday morning but then become breezy once again late
Saturday morning.
&&
.PREV DISCUSSION... /issued 218 PM CDT Fri Apr 22 2022/
SHORT TERM...
The main focus for this afternoon and evening will be the
possibility for strong to severe thunderstorms. Clouds have been
slow to clear the region resulting in temperatures just now reaching
the 80 degree mark. Temperatures should continue to slowly rise
through the afternoon as additional sunshine is attained. Cooler
temps have kept a fairly stout capping inversion overhead with 15Z
LBB AMDAR sounding showing a +6C inversion and a convective temp of
84F. Evidence of the still in place cap is evident on visible
satellite with low level cumulus present across much of the Caprock.
The CU field is most dense from Floyd county southwestward to Lea
county, New Mexico where surface moisture is abundant and surface
flow is somewhat convergent. Currently convective models are in a
general consensus that convective initiation should occur in this
general vicinity northward to the western Texas Panhandle as a
dryline works its way eastward from eastern New Mexico. Overall
upper level support for storm development appears to be marginal at
best which explains why models keep convective coverage isolated and
limited, if the model has convection at all. For now the forecast
will reflect low end storm chances. This will be due to storms
relying mostly on low level initiation which, like with the upper
levels, is lacking enthusiasm. If a storm is able to develop it will
have plenty of CAPE to work with as SPC RAP Mesoanalysis continues
to show MLCAPE between 2000-2500 j/Kg, 0-6 km shear around 50+
knots, and modestly steep lapse rates. The main threats will be wind
gusts up to 70 mph and large hail up to baseball size. The overall
lack of backed surface winds and weak 0-1 km shear will limit the
overall tornado threat, but it will not be null as dewpoints remain
near 60F. Storms will move quickly to the northeast with the overall
convective threat decreasing significantly after sunset.
The combination of a developing surface low over southeastern
Colorado and 40-50 knot LLJ will allow for a windy start to the
night with solid advisory level winds expected. GFS MOS is the most
bullish with sustained winds of 46 mph forecasted at LBB between 7
PM and 1 AM. NAM MOS keeps winds slightly lower at 40 mph. The wind
forecast has been increased accordingly for this evening to reflect
the potential for strong winds. The Wind Advisory will remain in
place through 1 AM tonight across the entire South Plains region.
The upper low currently over the Four Corners will push a Pacific
Front through the region late tomorrow morning into the afternoon.
Though still on the breezy side, winds will be lower tomorrow
afternoon than what is expected tonight (15-20 mph). Minimum RH
values will drop to near 10 percent area wide tomorrow afternoon
despite slightly cooler temps. This will result in elevated to
critical fire weather danger.
LONG TERM...
As the upper level trough spins off into the Northern Plains on
Saturday, it will send a cold front through the area late Saturday
through early Sunday. This will provide the area with several days
of cooler than seasonal average temperatures. This front is still
expected to stall out just to the south of the area after it moves
through on Sunday. Another short wave moving through the
central/southern Rockies will rotate around the larger scale trough
on Sunday. This will keep southwesterly flow aloft near the frontal
zone. Areas close to the front could see widespread heavy rainfall
which may affect portions of the southern Rolling Plains and
southern South Plains. The location of heavy rainfall will be highly
dependent on the position of the stalled out front. There will be a
strong demarcation between high and low precipitable water air. This
will last through the day Sunday into early Monday when a
reinforcing shot of surface ridging moves into the area.
Temperatures will be on the increase beginning mid-week with an
upper ridge moving overhead.
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
Fire Weather Watch from Saturday morning through Saturday
evening for TXZ021>044.
Wind Advisory until 1 AM CDT Saturday for TXZ021>044.
&&
$$
58/99/99
...Updated Aviation Forecast Discussion...
.DISCUSSION...
Issued at 350 PM CDT Fri Apr 22 2022
.Forecast Summary:
Strong winds continue tonight and Saturday. Dangerous fire-weather
conditions and some severe-weather threat developing on Saturday
afternoon. Trending cooler this weekend into Monday.
.Tonight:
A potent shortwave trough and attendant mid/upper-level jet streaks
over the lower-CO Valley into Four-Corners region as of early
afternoon will intensify while advancing into the northern and
central Plains tonight. In the low levels, a deepening lee cyclone
over southeast WY is forecast to develop into central SD while a
trailing Pacific front advances east through central parts of NE and
KS overnight.
12z regional soundings revealed a strong cap at the base of an
elevated-mixed-layer with recent ACARS data indicating that capping
has spread east/northeast over the Omaha vicinity since 12z. As
such, it appears that diurnally enhanced thunderstorm development
will likely remain confined to western and perhaps central NE late
this afternoon through evening, in closer proximity to the surface
low and increasing forcing for ascent ahead of the midlevel
system.
Of note, mid-afternoon visible satellite shows a growing cumulus
field over central NE, which some model guidance suggests could
eventually evolve into a small cluster of storms over north-
central NE by late afternoon or early evening. Expected storm
motions would likely keep that activity to the west of our area.
Otherwise, it appears that isolated showers and thunderstorms
could move into the area late tonight into Saturday morning within
the exit region of the upper-level jet streak nosing into the
mid-MO Valley. Forecast soundings suggest that residual capping
will limit the potential for surface-based storm development with
any convection likely being elevated in nature. Severe weather
potential currently appears low.
South winds will remain strong overnight owing to some
mixing/coupling with a 50-60 kt low-level jet. Therefore, we have
extended the Wind Advisory until 5 AM for many of our NE
counties.
.Saturday and Saturday night:
A deep-layer cyclone forming over SD late tonight/Saturday
morning will track east through the northern Plains on Saturday
and Saturday night. The aforementioned, trailing Pacific front is
forecast to move through our area on Saturday afternoon and
evening with a much drier low-level air mass overspreading the
region behind the boundary. Gradient winds will remain strong due
to the proximity of the low, so we have issued a Wind Advisory
areawide on Saturday. The winds will combine with the dry air
moving in behind the front to create a potentially dangerous
wildfire environment over portions of northeast into southeast NE.
Therefore, we have issued a Fire Weather Watch for a portion of
the area for Saturday afternoon and evening.
Meanwhile ahead of the front, a moist boundary layer coupled with
daytime heating will yield a weakly to moderately unstable air
mass by afternoon over far eastern NE into southwest IA. The
models suggest that a pre-frontal trough or confluence line may
be the focus for shower and thunderstorm development by mid/late
afternoon on Saturday from southwest IA into east-central and
southeast NE. Storms may tend to consolidate into a line as the
Pacific front overtakes that boundary during the early evening
hours.
Severe weather potential will be modulated by the degree of warm-
sector instability. Forecast hodographs exhibit a veer-back
signature, which combined with the deep-layer shear vector and
storm-relative anvil-level winds being aligned largely parallel
to the boundary suggest the likelihood of mixed and/or linear
modes (as mentioned above). Midlevel lapse rates will not be
particularly steep, so it appears that damaging wind gusts will be
the main hazard. However, sufficient low-level shear will exist
such that a brief tornado can`t be ruled out.
Highs on Saturday will be mainly in the 70s.
.Sunday and Monday:
Midlevel troughing is forecast to linger from the upper-MS into mid-
MO Valley, coincident with low-level ridging. That pattern will
support cooler temperatures with highs in the 50s and 60s.
.Tuesday through Thursday:
The 12z global models indicate that a low-amplitude ridge in the
midlevels will build east into the Great Plains next week with
mainly dry and warmer conditions expected. There is some model
signal that a weather system could move into region next Friday or
Saturday, which would support increased precipitation chances.
&&
.AVIATION...(For the 00Z TAFS through 00Z Saturday evening)
Issued at 608 PM CDT Fri Apr 22 2022
Strong south winds will persist through the forecast period with
LLWS developing tonight into Saturday morning. MVFR ceilings
could move back in early Saturday morning, with the best chance
for coverage over KOMA. Latest model data indicate that shower
and thunderstorm chances remain very spotty into Saturday
morning. Therefore, we will not include a mention at this time.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...Wind Advisory until 7 PM CDT Saturday for NEZ011-012-015>018-
030>034-042>045-050>053-065>068-078-088>093.
Fire Weather Watch from Saturday afternoon through Saturday
evening for NEZ012-015-017-018-030>034-042>044-050-051-065-
078.
IA...Wind Advisory from 10 AM to 7 PM CDT Saturday for IAZ043-055-056-
069-079-080-090-091.
&&
$$
DISCUSSION...Mead
AVIATION...KG