Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 04/06/24
Area Forecast Discussion
National Weather Service Cheyenne WY
516 PM MDT Fri Apr 5 2024
.KEY MESSAGES...
- Thunderstorms are possible Saturday afternoon in portions of
the Nebraska panhandle. Severe weather is not expected at this
time.
- Strong winds are expected for the wind prone areas with gusts
of up to 90 MPH possible. Wind gusts of 60 to 75 MPH are
expected across the rest of the eastern plains into the
Nebraska panhandle.
- Confidence is increasing in a significant winter storm
impacting portions of the area Saturday through early Monday.
The Pine Ridge (US-20 corridor) and have the highest
probability of significant impacts.
&&
.DISCUSSION /THROUGH FRIDAY/...
Issued at 430 PM MDT Fri Apr 5 2024
Latest GOES imagery shows wave clouds that were positioned over much
of the area this morning, continuing to clear to the east and thin.
This delayed morning warming across much of the area, but
temperatures have warmed into the 60s and even low 70s for a few
spots so far today. This has led to a slow start to potential
critical fire weather conditions this afternoon for the areas under
a Red Flag Warning, but RHs continue to drop near critical
thresholds through the early evening. West of the Laramie Range,
latest SPC mesoanalysis shows around 500 J/kg of SBCAPE with showers
developing along the North Laramie Range and in Carbon Co. We could
still see a few lightning strikes out of these storms through early
this evening. Additionally, southwest Carbon Co has seen strong
winds this afternoon up to 60 mph with a stream of enhanced 700mb
flow ahead of the upper level low over northern NV, continuing to
march this way.
Upgraded to High Wind Warnings this evening for the northern NE
panhandle including Alliance and Chadron, however strongest winds
are expected along the Pine Ridge. A stronger LLJ looks to develop
early this evening with better upper level divergence beginning to
approach the region. While hi-res guidance is not as aggressive as
yesterday for the wind potential tonight, latest HREF has
probability of exceeding 60 mph wind gust tonight > 50% from 10 PM
to 2 AM. Even if areas don`t reach high wind criteria, gusty winds
are expected across the NE panhandle tonight likely keeping
overnight lows on the higher side, mostly in the 40s again.
More widespread precipitation will begin to approach the CWA later
tonight, starting over Carbon Co as the initial front with this
system moving across our area from the west. Accumulating snowfall
is possible in the Snowy and Sierra Madres leading to the need for a
Winter Weather Advisory beginning at 9 PM tonight. This front will
continue to move across the Laramie Range early Saturday morning
with strong west/northwest flow developing behind the front (see
next paragraph). Hi-res guidance continues to favor lee cyclogenesis
in northeast CO with good southeast moisture advection into central
NE, possibly reaching as far west as Morrill through Dawes Co.
Latest RAP brings over 500 J/kg of MLCAPE into these areas as
precipitation becomes more widespread with the better upper level
dynamics with this system overhead. Right now, leaning towards
widespread afternoon rain showers for most areas east of I-25 with a
few rumbles of thunder in the NE panhandle, but severe thunderstorms
could be possible just to our east in central WY.
The more significant high wind event looks to begin across southeast
WY wind-prone locations Saturday morning, spreading out across the
Laramie Range and adjacent foothills by midday. Wind gusts exceeding
65 mph are likely during the afternoon hours for much of the I-80
corridor from Elk Mountain through Sidney with stronger winds
expected Saturday night. Latest NAEFS guidance shows 700mb winds
along the South Laramie Range and Foothills climbing above the
climatological 99th percentile to near climo max values late
Saturday afternoon into Saturday night.
As we head into Saturday evening, the strong, negatively tilted
trough aloft will support impressive surface cyclogenesis, with a
sub 990-mb low located most likely just east of our eastern row of
counties. The Saturday evening through Sunday morning will be the
most impactful period of the system, with the sting jet peaking and
the TROWAL becoming established, wrapping precipitation back around
into our area in the cold sector of the system. This is looking more
like an upper-tier wind event, even for our area. In addition to the
impressively strong 700-mb winds, the negatively tilted trough aloft
will result in a fairly rare set-up for our area. Since the surface
low will be located in a favorable position underneath the upper
level trough, forecast soundings actually show easterly flow atop
the sting jet, with the core of this layer around 300 to 400-mb. A
flow reversal aloft is very rare for westerly wind events, but this
feature will cause vertically propagating mountain waves to be
reflected back to the surface, potentially amplifying surface winds
further. We also have an inversion present in the forecast sounding.
While this is initially forecast to be centered around 550-mb (much
too high for the mountain-top inversion that favors wave-breaking
and amplification at the surface), both the NAM and GFS show a
secondary inversion developing around midnight at about 700-mb,
which is closer to mountain-top height in our area. With this,
expect winds to peak during the hours from about 10PM Saturday to
5AM Sunday. By sunrise Sunday, models show that the upper level
trough will have propagated far enough to the north to remove the
flow reversal aloft, which should allow winds to ease from an upper-
tier wind event to just a normal wind event. During the peak period
though, would not be surprised to see gusts of 90+ MPH showing up in
the wind prone areas, and possibly 75+ MPH even into the Cheyenne
area. Elsewhere in the High Wind Warning, widespread gusts of 60 to
70 MPH are expected through midday Sunday.
Moving on to the wet side of this system, we`ll have precipitation
filling back in across our northern and eastern areas on Saturday
afternoon/evening as the TROWAL develops. While isentropic flow
actually looks more or less parallel to the isobars (not promoting
lift), low level convergence between the north to northeast flow
over South Dakota and the sting jet over our area will promote a
nearly stationary area of impressive frontogenesis. As guidance has
come into better agreement on the exact low position, we have
improved confidence in a few areas, but the periphery zones still
have some uncertainty. Almost all guidance how shows areas SW of a
Wheatland to Kimball line solidly outside of the TROWAL, and thus
with fairly minimal precipitation. While the mountains will continue
to pick up on and off snow, the valleys (aside from perhaps Laramie)
are not expected to receive more than a dusting to an inch or so of
snow. Almost all guidance has the area from eastern Converse County
towards Chadron within the region of heavy precipitation, which
boosted confidence enough to upgrade Niobrara and northern Sioux
counties to a Winter Storm Warning. Ensemble mean total QPF is
running 1.5 to 2.0 inches along the Pine Ridge, including Lusk and
Harrison. Above about 4500 to 5000 feet, this is expected to be
mostly snow. While ratios could be on the low side, that much liquid
will lead to heavy snow in any scenario. Wouldn`t be surprised to
see a report approaching 2 feet, although it will be very difficult
to measure with widespread 50 to 60 MPH winds. The remaining
question for Niobrara and Sioux counties is if we`ll be able to
reach blizzard criteria. Right now, at least localized blizzard
conditions look likely, but will let it continue as a strongly
worded Winter Storm Warning to allow for a few more model cycles to
come in.
There are also a few lower confidence points remaining. First,
models have trended slightly east with the TROWAL over the last 24
hours or so, which could put Converse county on the periphery. With
a sharp cutoff expected on this edge, this kept confidence too low
to upgrade this area, as well as the northern Laramie range.
Additionally, the trend towards more WNW (rather than north) winds
in this area is less favorable for upslope in the Douglas area and
northern Laramie Range. Shaved snow totals slightly for this area
with this update, but will let the Winter Storm Watch continue as we
are now right around the low end of criteria for both zones. Further
east, the main uncertainty is less in the TROWAL edge, but in the
temperatures and snow levels. Snow levels should end up between 3000
feet and 4000 feet, but unfortunately that band includes the
majority of population centers in the Nebraska panhandle, including
Scottsbluff, Alliance, and Chadron. There is fairly high confidence
in Warning criteria (and potentially 12+ inches) falling in the Pine
Ridge south of Chadron, but confidence decreases heading into the
city itself. Just a slight difference in temperature and snow level
could mean the difference between a few flakes that mostly don`t
stick, or a high impact winter storm. Therefore, decided to expand
the Winter Storm Watch to include Dawes, Box Butte, and southern
Sioux counties. The southern half of the panhandle could also see
winter impacts, but most guidance ends up under Winter Storm Warning
Criteria, but later shifts will need to consider an Advisory as we
get closer.
After that, look for a very gradual warming trend, hampered by a few
weak disturbances moving around the slow to depart upper level
trough. Better confidence in ridging over the area returns towards
the end of next week.
&&
.AVIATION /00Z TAFS THROUGH 00Z SATURDAY/...
Issued at 509 PM MDT Fri Apr 5 2024
Main immediate concern this evening will be strong winds over
the Nebraska Panhandle...where High Wind Warnings are in effect
for both KCDR and KAIA. Looking at 50+ knots after roughly 03Z
tonight...lasting through early Saturday morning. After a brief
lull Saturday morning...winds will once again increase across
all of southeast Wyoming. Forecasting 50+kts at KCYS and KLAR
that will continue increasing through the afternoon into the
evening hours Saturday. Could even see 60+kts at KCYS...when the
cold front comes through and turns winds to the northwest.
Behind the front...snow is expected to develop along with these
strong winds. So LIFR and IFR conditions expected to return.
Ahead of the front...looks like a good bet at seeing some
thunderstorms in the Nebraska Panhandle for a few hours before
the front moves through. IFR/LIFR conditions widespread Saturday
night through Sunday all airports.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...High Wind Warning from noon Saturday to 3 PM MDT Sunday for
WYZ107-108-115-118-119.
Red Flag Warning until 7 PM MDT this evening for WYZ430-431.
Winter Storm Warning from 3 PM Saturday to 6 AM MDT Monday for
WYZ102.
Winter Storm Watch from Saturday afternoon through late Sunday
night for WYZ101.
Winter Storm Watch from Saturday morning through late Sunday
night for WYZ103.
High Wind Warning from 6 AM Saturday to 3 PM MDT Sunday for
WYZ106-110-116-117.
High Wind Warning until 8 PM MDT this evening for WYZ111.
Winter Weather Advisory from 9 PM this evening to noon MDT
Saturday for WYZ112-114.
NE...High Wind Warning until 4 AM MDT Saturday for NEZ002-003-095.
Winter Storm Watch from Saturday evening through late Sunday
night for NEZ002-003-096.
High Wind Warning from noon Saturday to 3 PM MDT Sunday for
NEZ019>021-054-055.
Red Flag Warning until 7 PM MDT this evening for NEZ437.
Winter Storm Warning from 3 PM Saturday to 6 AM MDT Monday for
NEZ095.
&&
$$
SHORT TERM...MN/MB
LONG TERM...MN
AVIATION...GCC
Area Forecast Discussion
National Weather Service Hastings NE
610 PM CDT Fri Apr 5 2024
.KEY MESSAGES...
- Significant impactful weather expected over the weekend.
- Strong non-thunderstorm wind gusts of 50-60 MPH develop
Saturday afternoon and continue for at least portions of the
area into Saturday night and Sunday. Blowing dust and reduced
visibilities may develop as a result.
- A line of thunderstorms is likely (60-90 percent) to develop
along a surging dry line Saturday afternoon. There is a slight
risk (level 2 out of 5) for severe weather.
- Dangerous fire weather also expected each day this weekend,
even in areas where humidity doesn`t necessarily fall to
critical levels, due to the very strong winds. The worst
combination of wind and low humidity will be in N KS.
- Forecast for next week is much quieter, with high temperatures
mostly in the 50s and 60s. At least partial cloud cover is
forecast locally for the eclipse on Monday, though widespread,
dense cloud cover appears unlikely (<20% chance)
&&
.DISCUSSION...
Issued at 445 PM CDT Fri Apr 5 2024
Forecast Details:
Very busy forecast over the next ~48 hours. Will discuss fire
weather concerns in dedicated section below.
The next 12 hours should remain fairly quiet, though breezy, as
low pressure deepens along the lee of the Rockies and mid to
high clouds stream in from the SW.
Forecast concerns ramp up by around midday Saturday, first due
to forecast very strong non-thunderstorm/gradient SErly winds.
Model guidance remains in good agreement in developing a
45-55+kt low level jet tonight that only slowly shifts east and
weakens with time on Saturday. Forecast soundings suggest much
of the area will mix up into the decaying low level jet and
begin to mix down solid 45 to 55 MPH wind gusts around early
afternoon. NBM guidance suggests at least 50% chance for wind
gusts over 50 MPH, and this is backed up by raw model guidance such
as the RAP/HRRR/EC, which are generally stronger and suggest
potential for gusts up to around 60 MPH. Hi-res guidance is
particularly strong with the gradient SErly winds in the ~3hrs
preceding a dry line and expected line of thunderstorms - or
roughly 2-6PM CDT. Have upgraded the High Wind Watch to a
Warning to account for this potential. With the strong winds
will come fire weather (see below) and blowing dust concerns.
Exact magnitude and impacts from blowing dust are always
difficult to pin down given that the most widespread dust is
often transported in from source regions along the High Plains.
However, we can and do occasionally produce our own, often more
narrow but more intense, plumes locally. This is particularly
true during the shoulder months of the growing season (Mar-Apr,
Oct-Nov). Have added mention of blowing dust to the grids and
HWO, but headlines are often more of a nowcasting situation for
our local area.
Severe thunderstorm potential will ramp up by early to mid
afternoon hours Saturday, as an intense upper trough ejects onto
the Plains and forces a strong dry line into central NE/KS.
Latest model consensus is for a sub 990mb low pressure center to
develop over NE CO/W NE, with a warm front extending eastward
from there. This would place vast majority of the area in the
warm sector by mid-aftn, with temps rising into the 60s and
lower 70s, perhaps locally warmer depending on cloud cover.
Moisture return is the biggest question mark with this system,
and whether or not there will be enough time to advect moisture
in from the TX gulf coast region. Current dew points locally are
only in the 20s, and the closest 50F dew point is near DFW...so
there`s a lot of work to be done in this department. However,
18-24 hours can be enough time to advect at least a narrow
swath of marginally favorable moisture when low level winds are
as strong as they`re forecast to be tonight-Sat. As such, model
consensus has crept a little higher with forecast dew points for
Sat aftn, at least in a very narrow corridor along and
immediately ahead of the surging dry line, into the low to mid
50s range. Sometimes models overdo the magnitude/rate of
moisture return in early season events, but the model consensus
seems reasonable given aforementioned strong winds and more
SErly component to low level flow. Mid level lapse rates will be
sufficiently steep, amidst strong deep layer shear 40-60kt, for
severe hail, with the main limiting factor being instability.
Especially early on, the shear will likely be too strong for
updrafts to withstand, so severe hail may be somewhat limited.
More likely impact will likely come from damaging straight line
winds owing to already strong ambient flow and linear storm
mode. Add in the fact storms will be racing at 45-55 mph, and it
just won`t take much to get severe 60-70 MPH winds to mix to the
surface. Finally, assuming the low to mid 50s Tds do in fact
make it in time, then certainly a decent chance for some QLCS
tornadoes given 0-3km shear/CAPE of 30-40+kts and 150+ J/kg.
This could be a very similar situation to Oct 12th 2023, but
with a tad more warmth and moisture. Main timeframe of concern
is 1PM to 8PM from SW to NE.
Focus will shift back to strong gradient winds for Saturday
night and into Sunday as the sfc low bottoms out around 985mb
just NW of the area in the Neb. Sandhills. Increasingly negative
tilt to upper trough will promote very strong and uniform W/NW
low to mid level flow and deep mixing, esp. for overnight
standards. Hi-res guidance suggests a lull in strong wind gusts
Sat night, but prefer the stronger EC given it`s such a dynamic
low pressure system which continues 45-50+ MPH gusts for at
least our far W counties, that are higher elevation, through
the night. As mixing depth incr further with daytime heating
Sunday, expect a corridor of 50-60 MPH gusts to develop roughly
along and SW of a line from Lexington to Osborne, with even some
60-65 MPH gusts possible for some areas in Furnas, Phillips, and
Rooks Counties Sun aftn. Wind gusts should be lower, though
still not pleasant, in the 30-45 MPH range N of this line where
mixing will be lesser owing to cloud cover, and closer proximity
to sfc/mid level low center. Given the latest forecast trends,
opted to extend the High Wind Warning only for the W/SW zones
beyond 00Z Sun. Could argue nearly E half of HWW is overdone Sat
night, but didn`t want to make an already difficult to
communicate wind forecast even worse with a 3rd segment. As is
the case on Sat, would expect areas within the HWW to again have
some blowing dust issues, either from local sources or
additional transport from E CO/W KS. Winds should finally decr
more substantially Sun eve as we lose daytime heating and the
trough begins to fill/weaken.
Was not able to spend much time on the rest of the forecast,
which is good since it appears to be mainly dry and seasonable
temperature wise with highs in the 50s and 60s, perhaps low 70s
by late next week. Even though we`re not within the path of
totality locally, will still likely be some interest in
observing the 60-80% eclipse on Monday. Latest model guidance
suggests some wrap around moisture from the departing upper
trough to possibly generate some clds for portions of south
central Nebraska, though appears the thick/widespread cloud
cover favors areas further N closer to NE/SD border. KS zones
look to have the best chance for clear to mostly clear skies.
&&
.AVIATION /00Z TAFS THROUGH 00Z SUNDAY/...
Issued at 544 PM CDT Fri Apr 5 2024
It is looking breezy/ windy over the next few days as a strong
low pressure system will slowly move across the Plains. Wind
gusts tomorrow afternoon are expected to gust into the 40-46kts
range. Looking at the HRRR for VCTS timing, it is looking like
the afternoon time frame when a line of SHRA/TSRA could move
through the area. 20-21 is best guess for now, but wouldn`t be
surprised if they came in a little faster.
&&
.FIRE WEATHER...
Issued at 455PM CDT Fri Apr 5 2024
Rest of today:
Bit of a sneaky fire weather day this aftn as several sites have
been hitting or at least flirting with RFW criteria. Breezy
SErly winds were a given, but humidity values have come in 5-10%
lower than forecast. Onset of nocturnal cooling should allow for
RH recovery into at least the 40-60% range overnight, though
winds will remain quite strong out of the SE.
Fire weather concerns ramp up with the incr winds mid to late
Sat AM pretty much area wide. RH values will probably remain in
the 30-50% range late AM and early aftn (prior to the arrival
of the dryline), which is well above traditional critical
criteria of 20%. However, the stronger the winds get (esp. 45+
MPH), the less important RH becomes to fire behavior, esp. with
cured fine/1hr fuels...so definitely still a concern. Debated
issuing a RFW for at least central and eastern Neb. zones
(similar to what OAX did for their area), but felt the HWW could
capture/convey the fire threat as well given the somewhat
marginal RH and even some potential for sprinkles or very light
rain showers ahead of the front. The more "traditional" overlap
of strong winds AND low RH <30% will be over north central KS
immediately behind the dryline. Here, some models suggest RHs
may plummet even lower than the currently forecast upper teens
to mid 20s, given very deep mixing and strong S-SW- WSW winds
gusting 40-50+ MPH. Haven`t gone quite this bad in latest
grids/messaging, but opted to upgrade these areas to a Red Flag
Warning to capture the highest end threat.
Finally, opted to issue another Fire Weather Watch for Sun aftn
for portions of the outlook area. Wrap around moisture should
keep RHs N of the state line fairly high in the 40-50%+ range,
and cloud cover should even keep wind gusts lower. However,
appears lesser cloud cover (thus, deeper mixing) and warmer
temps could support aftn min RHs in the 20s to lower 30s for
portions of north central KS, which is also where wind gusts
will likely be highest in the 50-60 MPH range. Locally higher
gusts from Furnas to Rooks County is possible. These conditions
would support another round of high end fire weather and perhaps
another Red Flag Warning.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...High Wind Warning from noon Saturday to 7 PM CDT Sunday for
NEZ060-072-073-082>084.
High Wind Warning from noon to 7 PM CDT Saturday for
NEZ039>041-046>049-061>064-074>077-085>087.
KS...High Wind Warning from noon Saturday to 7 PM CDT Sunday for
KSZ005-006-017>019.
Red Flag Warning from 3 PM to 8 PM CDT Saturday for KSZ005>007-
017>019.
Fire Weather Watch from Sunday afternoon through Sunday
evening for KSZ005>007-017>019.
High Wind Warning from noon to 7 PM CDT Saturday for KSZ007.
&&
$$
DISCUSSION...Thies
AVIATION...Beda
FIRE WEATHER...Thies
Area Forecast Discussion
National Weather Service Goodland KS
923 PM MDT Fri Apr 5 2024
.KEY MESSAGES...
- Areas of smoke overnight through mid morning from southern
wildfires across eastern portions of the area.
- Multiple hazards Saturday including severe weather, blowing
dust and west to northwest winds gusting 40 to 55 mph. Shower
and thunderstorm chances in the 20%-60% range.
- Strong wind gusts along and north of I-70 Saturday night with
gusts of 40 to 60 mph.
- Multiple hazards Sunday including fire weather, blowing dust
and northwest winds gusting 45 to 65 mph.
&&
.UPDATE...
Issued at 918 PM MDT Fri Apr 5 2024
Near surface smoke from the 00Z run of the HRRR is lining up
very well with current observations of 4sm or less across
central and south central Kansas so did opt to include in the
forecast overnight through the mid morning.
18Z run of the GFS continues to strongly suggest blowing dust
both tomorrow and Sunday. There is some concern for a Haboob
developing across eastern Colorado with the main cold front as
all in office dust parameters are being met along and just
behind the front and moves along with the front. 18Z run also
does show it dispersing some as it gets into western Kansas but
also does continue to show another potential plume developing
from Logan/Washington/Phillips counties in Colorado which is
known source region for dust. With all of this did get a bit
aggressive with the coverage of dust in the forecast.
&&
.UPDATE...
Issued at 810 PM MDT Fri Apr 5 2024
Relative humidity is increasing with the loss of diurnal heating
and winds have relaxed; albeit still breezy gusting from the
southeast at 30 mph at times. As a result of the lack of critical
fire weather conditions the Red Flag Warning has been allowed to
expire on time.
&&
.SHORT TERM /THROUGH MONDAY/...
Issued at 245 PM MDT Fri Apr 5 2024
Tonight...the forecast area remains in between low pressure systems
over the west of the Rockies and Mid Atlantic states. A 10mb surface
pressure gradient over the area supports some breezy to windy
southerly winds with gusts up to 40 mph. Low temperatures are
forecast to be in the upper 30s to around 50. Stratus (low clouds)
are anticipated from Trenton to Oakley and points east a few hours
prior to sunrise.
Saturday-Saturday night...at 500mb, low pressure is forecast to
redevelop over southeast Colorado in the morning, lifting northeast
into southwest Nebraska by 00z then into central Nebraska during the
night. At the surface, low pressure across eastern Colorado moves
toward the CO/KS border by 18z then into central Nebraska by
00z then slowly moving toward south central South Dakota
overnight.
Southeast winds in the morning gradually veer to the southwest then
west and northwest through the day, remaining from the west and west-
northwest overnight. Wind gusts will be highest from late morning
through the afternoon with gusts of 45 to 60 mph. The highest gusts
overnight are generally north of Interstate 70 with values of 30 to
50 mph.
Regarding blowing dust potential, based on local research findings,
GFS and GEM models (both excellent track records for blowing dust)
forecasts of 0.5-1km wind speeds exceeding 44kts and steep 0-2km
lapse rates exists generally along and north of I-70 from around 18z-
00z. An enhanced area of blowing dust is possible across Yuma county
toward the KS/NE border counties where potential plume slowly lifts
north. 2-2.5km lapse rates below 5C/km suggest dust would not be
able to dissipate into the atmosphere, basically becoming capped in
the 0-2km layer and supporting higher dust concentrations and thus
lower visibilities.
High temperatures are forecast to range from the lower 50s to around
60 in far eastern Colorado to the lower 70s across Norton and Graham
counties. For the western 1/2 of the area, high temperatures will
occur earlier in the day than usual, basically ahead of the cold
front. Low temperatures are forecast to be in the lower 30s to lower
40s.
Regarding precipitation chances, they`ll increase from late morning
through the afternoon as the upper low moves across from the
southwest. Areas from Tribune/Leoti northeast toward Oakley may get
dryslotted so for now they look to be dry. Overnight, wraparound
moisture in the 850-500mb layer favors light rainfall for locations
generally along and north of I-70 with the highest chances across
extreme southwest Nebraska. The extreme northeast and eastern parts
of the area are outlooked with a Marginal Risk of severe weather.
Presently, the window for this to occur would be from early to mid
afternoon.
Sunday-Sunday night...the main concern is for blowing dust and
potential for a wall of dust to impact the area. GFS/GEM models were
used along with local research findings (results listed for Saturday
time period) and support blowing dust from mid morning through the
afternoon for locations generally north of a line from Flagler to
Leoti. Of greater concern is for a prolonged plume or wall of
blowing dust to impact areas from around Yuma and Wray southeast
toward Colby and Oakley. Very low visibilities are possible if not
likely given current data. Northwest winds gusting 50 to 65 mph are
forecast. Overnight, northwest winds decrease into the 10 to 15 mph
range.
There will be a 20%-30% chance for wraparound rain showers during
the day along and north of the KS/NE border with dry weather
forecast overnight. High temperatures are forecast to be in the
middle 50s to middle 60s with low temperatures in the middle 20s to
middle 30s.
As a result of all the strong winds and wind gusts expected, a
High Wind Warning is in effect Saturday 18z through 00z Sunday
for wind gusts up to 65 mph.
Monday...dry weather is forecast with high temperatures in the upper
50s to middle 60s.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
Issued at 217 PM MDT Fri Apr 5 2024
Looking into the long term, we begin with a continuation of the wet
pattern due to an area of low pressure moving over the Texas
Panhandle and Red River Valley Monday night through Wednesday.
Confidence in rain chances is low to medium given how far south the
low is projected to go; however, a slight wobble to the north can
lead to higher confidence and chances. PoPs currently are forecast
to be in the 20s to mid 30s with the best chances for rain (25+%)
generally south of I-70. Locales along and north of the interstate
may see little to no rainfall the further you are away from it. QPF
amounts in areas with the currently forecast best chances for
moisture remains low at less than 0.10". An upper ridge moves across
the Western CONUS and over the High Plains beginning on Thursday.
This will bring a return of dry conditions to the area for the
remainder of the work week.
Temperatures Monday night are forecast to be in the upper 20s to mid
30s. Highs are expected to be similar day to day Tuesday through
Thursday with temperatures in the 60s across the Tri-State area.
Overnight lows are forecast to be in the 30s with some locales only
falling into the lower 40s. Friday looks to be the warmest of the
period with temperatures currently forecast to reach the mid to
upper 70s. Overnight lows could be in the 40s.
&&
.AVIATION /00Z TAFS THROUGH 00Z SUNDAY/...
Issued at 430 PM MDT Fri Apr 5 2024
For KGLD, currently VFR conditions are expected through the
forecast period. Winds, south-southeast around 25-40kts through
about 18z Saturday, then veering southwest 25-35kts. By 22z,
becoming westerly around 35-45kts. LLWS 03z-15z Saturday
160@55kts.
For KMCK, mainly VFR conditions are expected for the forecast
period. MVFR ceilings around BKN015 around 11z-17z. There is a
low chance for the terminal to see some potential thunder during
the latter portion of the forecast. Low confidence on timing,
so have left out for now but later forecast will begin to
include. Winds, southeast 20-40kts through about 20z Saturday,
then veering southwest around 30-40kts. LLWS 11z-17z Saturday
180@50kts.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...High Wind Warning from noon MDT /1 PM CDT/ Saturday to 6 PM
MDT /7 PM CDT/ Sunday for KSZ001>004-013>016-027.
CO...High Wind Warning from noon Saturday to 6 PM MDT Sunday for
COZ090-091.
NE...High Wind Warning from noon MDT /1 PM CDT/ Saturday to 6 PM
MDT /7 PM CDT/ Sunday for NEZ079>081.
&&
$$
UPDATE...Trigg
SHORT TERM...99
LONG TERM...KMK
AVIATION...JN
Area Forecast Discussion...Updated
National Weather Service Lincoln IL
733 PM CDT Fri Apr 5 2024
.KEY MESSAGES...
- Low temperatures will drop below freezing tonight. Precautions
should be taken to protect sensitive vegetation.
- The next chance for rain will arrive late Saturday night into
Sunday. There is a Marginal Risk (less than 15% chance) for
severe weather Sunday afternoon/evening.
- 20-40% cloud cover is expected during the solar eclipse on
Monday.
&&
.UPDATE...
Issued at 732 PM CDT Fri Apr 5 2024
Stratocumulus erosion has been steady on the northeast flank of
the cloud deck this evening, with the northern edge currently
extending from about Lac on southeast to Paris. RAP low level
humidity cross-sections continues to suggest a steady erosion over
the next couple hours, though skies may not be completely clear
as patches of cirrus continues to stream in from the west. The
cirrus should not make a significant dent in the temperature
forecast, which still looks good with lows in the upper 20s. Main
updates were to adjust the sky trends over the next several hours.
Geelhart
&&
.SHORT TERM... (Tonight through Saturday)
Issued at 220 PM CDT Fri Apr 5 2024
Cloud cover continues to blanket central Illinois early this
afternoon thanks to moisture trapped beneath a strengthening
subsidence inversion at around 800mb. Cloud elements have scattered
further north across Wisconsin/far northern Illinois and this
trend will continue southward into the KILX CWA early this
evening. RAP forecast soundings have consistently shown the
shallow moist layer eroding toward sunset, so think skies will
become clear across the board by mid-evening. With a ridge of high
pressure overhead and winds becoming very light, radiational
cooling will allow overnight low temperatures to drop below
freezing. 12z HREF shows a high probability (50-70% chance) of
temps dipping below 30F along/northeast of a Galesburg to
Effingham line...but a less than 5% chance for going lower than
28F. As a result, think lows will bottom out in the upper 20s to
around 30 degrees. Will continue the Freeze Warning for points
along/south of a Rushville to Danville line where the early stages
of the growing season have begun. High pressure will gradually
shift east of the region on Saturday, resulting in ample sunshine
with cool high temperatures in the middle to upper 50s.
As a deep upper low visible on 18z/1pm water vapor imagery over
Nevada pivots northeastward, the next chance for rain will arrive
in central Illinois by late Saturday night. Given initially dry
E/SE boundary layer flow, have removed PoPs in the Illinois River
Valley during the evening...and have reduced overnight PoPs east
of I-57 to just 20%. Further west, it appears light showers will
spread as far east as a Bloomington to Shelbyville line after
midnight.
Barnes
.LONG TERM... (Sunday through Next Friday)
Issued at 220 PM CDT Fri Apr 5 2024
After a period of showers early Sunday, a lull in precip chances
is likely from late morning through mid-afternoon before an
occluded frontal boundary approaches from the southwest. While
instability will initially be meager, NAM suggests a narrow band
of MUCAPEs of 400-800J/kg along/ahead of the front late Sunday
afternoon into Sunday evening. Despite the weak instability,
strong deep layer shear with 0-6km bulk shear values of 50-60kt
will lead to a Marginal Risk for severe. NAM 0-3km VGP values
increase to 0.15-0.2, so if cells do indeed form along the
boundary, low-topped supercells with hail/gusty winds will be
possible.
Once the boundary passes, drier air will advect northeastward into
central Illinois late Sunday night into Monday. This will lead to
at least partial clearing for the eclipse Monday afternoon. There
are still some concerns about high cloudiness, so am not expecting
crystal clear viewing conditions. Instead think there will be
20-40% cloud coverage into the afternoon with much warmer
temperatures in the lower to middle 70s.
After that, warm and unsettled weather will be the rule for the
remainder of the week as the primary baroclinic zone remains
draped across the Ohio River Valley. While heavy rainfall looks
unlikely, rain chances will linger across at least the southeast
two thirds of the KILX CWA Tuesday through Thursday before the
front gets pushed further southeast by Friday.
Barnes
&&
.AVIATION... (For the 00z TAFs through 00z Saturday Evening)
Issued at 609 PM CDT Fri Apr 5 2024
Ceilings around 4500-5000 will linger for a couple more hours,
but the back edge of the lower cloud deck is moving in from the
northeast and should clear the TAF sites by mid evening. After
that, just scattered high clouds are expected through Saturday.
Winds will gradually trend toward the east/southeast over the next
24 hours, with an increase to around 10 knots or so occurring by
mid afternoon Saturday.
Geelhart
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
Freeze Warning from midnight tonight to 8 AM CDT Saturday for
ILZ040>057-061>063-066>068-071>073.
&&
$$
Area Forecast Discussion
National Weather Service Pueblo CO
454 PM MDT Fri Apr 5 2024
.KEY MESSAGES...
- Strong winds and widespread critical fire weather conditions
will persist into this evening across the plains and San Luis
Valley. Widespread critical conditions then return to the
plains and I-25 corridor on Sunday.
- Strong/damaging winds are likely over the mountains, San Luis
Valley and I-25 corridor Saturday into Sunday morning, the
windiest conditions will occur Saturday night. Areas along the
east slopes of the Rampart Range and near Cheyenne Mountain
may see extreme gusts over 75 mph.
- Snow squalls and blowing snow expected over the higher
mountains tonight and Saturday, with potentially some
difficult travel over high mountain passes.
- Windy again on Sunday, with critical fire weather conditions
possible across the eastern plains.
- New system comes in Mon-Weds, bringing more snow to the mountains
and rain to the plains. Speed of the passing system is still
uncertain.
&&
.SHORT TERM /THROUGH SATURDAY NIGHT/...
Issued at 239 PM MDT Fri Apr 5 2024
SW winds gusting in the 35-45 knot range were widespread across
the area this afternoon, while humidity has plummeted into the
single digits over the plains. Red Flag Warning was verifying
at most locations today, and a significant wildfire was
currently burning on the north side of Pueblo at mid-afternoon.
Wind will diminish slightly this evening as mixing ends, though
with strong winds aloft and rather tight surface gradient on
the plains, expect breezy to windy conditions through the night.
Will let Red Flag run until 9 pm, then humidity improves just
enough to allow it to expire. As upper low moves through the
Great Basin overnight, cold front will race eastward across
Colorado, bringing a quick burst of wind and snow to the higher
peaks along the Continental Divide from sunset through early Sat
morning, with front and snow impacting the Sangres after
midnight. Will keep winter wx advisories going for higher
mountain zones overnight into Sat morning, and wouldn`t be too
surprised to see a brief thunderstorm/snow squall accompany the
frontal passage.
Upper low then moves quickly through nrn Colorado on Saturday,
before stalling out over wrn Nebraska Saturday night/Sunday.
Could see a brief burst of rain/snow showers over the eastern
mountains and Palmer Divide Sat morning as bora cold front
races through, though main impacts may be more convectively
induced strong winds (50-60 mph) than any precip. Surface low
spinning up in nern CO and strong mixing once again will drive
surface winds close enough to high wind threshold to warrant
high wind warnings from the San Luis/Upper Arkansas Valley
eastward into the I-25 corridor, while speeds on the plains look
just low enough (40-50 mph) to preclude any wind highlights.
Converted fire weather watch for I-25/plains to a warning, though
did drop Kiowa County, where enough low level moisture wraps
southward around the surface low to keep RH above 15 percent.
Max temps Sat will run much colder than the past few days, with
most locations struggling into the 40s/50s.
From late afternoon Sat into Sun morning, window opens for
mountain wave induced high winds, as main upper jet stays south
of the CO/NM border, while strong mid level nwly flow develops
on the backside of the now stalled upper low over wrn NE.
Mountain top inversion begins to develop after 22z, with very
impressive reverse shear profile (70 kts near the surface/15
kts at 500 mb) in place overnight into Sunday morning. CAMs have
consistently pointed toward the eastern slopes of the Rampart
Range/Cheyenne Mountain as having the highest likelihood of
extreme winds, with some gusts over 80 mph certainly possible.
HRRR has also begun to highlight areas in the lee of the Sangres
for high winds, so didn`t get too cute with the High Wind
Warning and have it covering all of the southeast mountains/I-25
corridor at this point. Also added areas in the upper Arkansas
River around Salida and Buena Vista, as howling west winds
downslope off the Sawatch Range. Winds drop off fairly quickly
east of I-25, but suspect there will be a few pulses of 50-60 kt
gusts making it across Pueblo and Colorado Springs overnight.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
Issued at 239 PM MDT Fri Apr 5 2024
Sunday...
Breezy northwest winds will continue across the area on Sunday as
the upper low passes out of our region. Gusts will be stronger in
the morning, slowly waning throughout the day and weakening in the
evening. Along with this, poor humidity recovery overnight, coupled
with downsloping west winds, will result in more widespread critical
fire weather conditions across the eastern plains Sunday afternoon
for several hours. High temperatures will increase a few degrees,
hitting the mid-60s over most of the plains and mid-high 50s over
the valleys and parts of the higher terrain.
Monday-Wednesday...
As we move into the first part of the work week, the low that passed
through on Monday will slowly meander to our northeast as a second
low and associated trough dig down into the Four Corners region.
Showers will spread across the higher terrain late morning into
early afternoon, before spreading to the I-25 corridor and parts of
the southeast plains overnight into Tuesday. Coverage will increase
across the CWA as the low moves past us to our south Tuesday into
Wednesday, but at that point forecast confidence decreases a bit as
model solutions split. While most of the deterministic guidance is
consistent on sending the low across the states to our south, the
speed of the passing system is still in flux, which will have
notable impacts on the amount and duration of the precipitation the
plains get, especially late Tuesday and Wednesday. High temperatures
remain pretty consistent throughout the first half of the week,
mainly high-50s to 60s over most of the area, meaning that when
considering precip type for the upcoming system the mountains should
see light to moderate snowfall while the lower elevations strictly
receive rain.
Thursday Onwards...
The latter half of next week is still a bit uncertain in the model
data, but in general long-term solutions show the start of an upper-
level ridge building in overhead. Thursday and Friday will likely
see a quick warming trend, with the NBM hitting the high-70s over
the plains Friday afternoon. At this time, winds seem too light for
more fire weather concerns, but it cannot be ruled out quite yet.
&&
.AVIATION /00Z TAFS THROUGH 00Z SUNDAY/...
Issued at 444 PM MDT Fri Apr 5 2024
*** WINDSTORM TOMORROW ****
An intense mainly windstorm will move directly over central
colorado early tomorrow morning and will bring strong to intense
winds to the KCOS and KPUB TAF sites later tomorrow morning
into tomorrow afternoon.
For KCOS...strong southerly winds this evening into tonight
will dramatically shift to NNW around sunrise tomorrow and will
gradually intensify through tomorrow morning and reaching
speeds over 50 knot tomorrow afternoon. There may be a period of
intense snowfall at KCOS tomorrow morning around sunrise as the
central of the intense low moves over the Pikes Peak region.
KALS will be windy, but not as windy as KCOS or KPUB. There may
be a brief period of snow tomorrow morning.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory until midnight MDT Saturday night for
COZ058-060.
High Wind Warning from 8 AM Saturday to 11 AM MDT Sunday for
COZ060>063-072>088.
Winter Weather Advisory until 6 PM MDT Saturday for COZ066-068.
Red Flag Warning until 7 PM MDT this evening for COZ224.
High Wind Warning from 8 AM to 8 PM MDT Saturday for
COZ069>071.
Winter Weather Advisory from midnight tonight to noon MDT
Saturday for COZ073-075.
Red Flag Warning until 9 PM MDT this evening for COZ226>237.
Red Flag Warning from 11 AM to 8 PM MDT Saturday for
COZ227>233-235>237.
&&
$$
SHORT TERM...GARBEROGLIO
LONG TERM...PETERSEN
AVIATION...HODANISH