Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 02/27/24
Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
854 PM CST Mon Feb 26 2024
.KEY MESSAGES...
- A cold front crossing the region tonight into Tuesday will bring
significantly colder temperatures and strong northerly winds with
gusts 45 to 50 mph. While snowfall accumulations are expected to be
light (probability of snow of 1" or more is 15 to 40% along the
ND/SD border), snow falling on warmer roads may lead to some travel
impacts.
- Cold to start the long term, but temperatures trending to above
normal by late week and into the weekend. Mainly dry until
Sunday/Monday.
&&
.UPDATE...
Issued at 844 PM CST Mon Feb 26 2024
Continue to watch the progression of the cold front dropping south
across ND and into northwest SD. Winds have turned northerly
across the northwest CWA, with the strongest cold air advection
and quickly falling temps lagging a couple hours behind the wind
shift. Overall, forecast still appears in fine shape in regards to
frontal passage timing and PoPs associated with the area of
snowfall expected behind the front. Don`t anticipate any changes
to the start times of the headlines either, which is 06Z across
north central SD.
UPDATE Issued at 534 PM CST Mon Feb 26 2024
Aviation discussion updated below for the 00Z TAFs.
&&
.SHORT TERM /THIS EVENING THROUGH TUESDAY NIGHT/...
Issued at 142 PM CST Mon Feb 26 2024
At 1 PM CST, under a mostly sunny sky, temperatures are warming
through the 50s and 60s on a southwest breeze of 5 to 15 mph. Some
locations will easily pass the 70F threshold this afternoon. New
high temperature records are being set. Low level WAA is noted
occurring over the entire CWA this afternoon, with a surface low
analyzed up along the Canada/ND border north of Walhalla. The much-
talked-about strong surface cold front is analyzed back to the west
from this surface low along the international border before dipping
down into central/north central Montana.
In the near term, the latest RAP guidance progs this cold front to
be entering/nearing the far northwest corner of the CWA by 6 PM CST
this evening, all the while developing a new surface wave of low
pressure along the boundary and working east across the CWA
overnight, while the cold front pushes south and east. The front
should be clear of the far southeast corner of the CWA by 6 AM CST
Tuesday.
Still dealing with really strong low level CAA, 9-15hpa 6hrly
pressure tendencies/rises, and enough overlap of forcing/lift along
and behind the frontal boundary to support some light snowfall from
late tonight through late Tuesday morning, mainly across north
central South Dakota, or northwest of a line from Eagle Butte to
Britton. The rest of the CWA likely sees enough low level moisture
wrung out of the PBL to support some brief snow showers across the
rest of the CWA; enough to notice that it snowed, but probably not
enough to "measure". Will convert the wind advisory across Corson,
Campbell and McPherson Counties to a winter weather advisory, as
they currently hold the highest probability of seeing at least an
inch of snow (35-65% chance). Elsewhere, the probabilities are much
lower. The strength of the low level CAA and pressure rises
continues to drive the need for a wind advisory elsewhere across the
CWA late tonight into the day on Tuesday. 925hpa temperatures by 12Z
Wednesday are progged to range from near -17C across Jones County to
-26C across Traverse, Big Stone and Roberts Counties, so very cold
air is progged to be in place across the CWA by the end of the
period. Wind chill values across the CWA are progged to fall below
zero late tonight into Tuesday morning, with the coldest wind chills
between -10F and -15F across the northern half of the CWA. Wind
chill values dip down again into the -10F to -20F range late Tuesday
night across the northeastern third of the CWA.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
Issued at 142 PM CST Mon Feb 26 2024
The long term portion of the forecast begins on Wednesday with an
upper level trough over the Great Lakes region, and ridging over the
northern Rockies. The ridge will build into the region throughout
the day, with high temps ranging from the mid 20s, in western MN, to
the upper 30s, west of the Missouri River valley. The warm air
advection will continue Thursday through Friday with highs by Friday
reaching the upper 50s, to the mid 60s. The probability of seeing 60
degrees on Friday from the NBM is 50 to 70 percent.
The forecast period become more challenging Saturday through Monday
as a storm system will bring a wide range of potential outcomes. All
deterministic and ensemble means show a storm system impacting the
northern plains early next week, with wintry pcpn and colder
temperatures possible. There are some indication the eastern CWA
could see showers Sunday afternoon, while colder air moves into the
western Dakotas where snow could be possible. Models are struggle
with the intensity and duration with this storm system, causing a
low forecast confidence with regards to potential impacts. As of
now, a few deterministic model solutions are moving the storm
through in two chunks. The first wave appears to move into North
Dakota on Sunday, where the majority of the pcpn may occur. A
secondary wave develops south of the area, with an inverted surface
trough over much of Minnesota, where the majority of the pcpn may
occur. Under this scenario, a good portion of the CWA may miss out.
Again though, an abundance of model spread yields a low forecast
confidence on a storm 5 to 8 days out.
&&
.AVIATION /00Z TAFS THROUGH 00Z TUESDAY/...
Issued at 534 PM CST Mon Feb 26 2024
Terminals KABR,KATY,KPIR,KMBG
A strong cold front will move through the region tonight, bringing
strong northerly surface winds gusting from 35 to perhaps 45
knots. MVFR CIGs and potentially IFR (mainly KATY) will also move
in overnight with this frontal passage. -SN is also expected from
KMBG to KABR Tuesday morning, with MVFR/IFR VSBY with potential
BLSN as well.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...Wind Advisory from 6 AM to 8 PM CST Tuesday for SDZ006>008-011-
018>023.
Winter Weather Advisory from 11 PM this evening to 11 AM MST
Tuesday for SDZ003.
Winter Weather Advisory from 3 AM to 6 PM CST Tuesday for SDZ004-
005.
Wind Advisory from 3 AM CST /2 AM MST/ to 6 PM CST /5 PM MST/
Tuesday for SDZ009-010-016-017-033>037-045-048-051.
Wind Advisory from 11 PM this evening to 11 AM MST Tuesday for
SDZ015.
MN...Wind Advisory from 6 AM to 8 PM CST Tuesday for MNZ039-046.
&&
$$
UPDATE...TMT
SHORT TERM...Dorn
LONG TERM...SD
AVIATION...TMT
Area Forecast Discussion
National Weather Service Grand Forks ND
955 PM CST Mon Feb 26 2024
.KEY MESSAGES...
- Winter impacts are expected tonight through midday Tuesday in
association with a strong cold front.
- Widespread heavy snow is not supported; however, a narrow
band of heavy snow is possible, where we could see upwards of
6 inches of snow or more.
- There is a 60 percent chance for blizzard conditions for
portions of the area where the heavy snow band correlates with
the highest wind gusts of up to 50 mph. Currently, the
highest probability of blizzard conditions is in the Central
Red River Valley.
&&
.UPDATE...
Issued at 955 PM CST Mon Feb 26 2024
Winds are beginning to pick up right on time with radar returns
entering the area as well. Expect conditions to deteriorate
overnight, and travel will be difficult in the central Red River
Valley up to NW Minnesota. Forecast remains on track.
Issued at 752 PM CST Mon Feb 26 2024
All winter storm watch counties have been upgraded to winter
storm warnings. Confidence has increased enough in the
possibility of warning impacts for it to be issued. Otherwise,
still uncertain on the setup of the mesoscale band in our area
that will lead to 6" + accumulations in some areas. Forecast
remains on track.
Issued at 647 PM CST Mon Feb 26 2024
Clouds are already making their way into the northern Red River
Valley and the Devils Lake Basin this evening. Seeing some
returns on radar as well, but not seeing observational ground
truth to any precipitation resulting from them. Uncertainty
still remains with heavy snow locations tonight, otherwise Forecast
remains on track.
&&
.DISCUSSION...
Issued at 345 PM CST Mon Feb 26 2024
Impacts today into Tuesday hinge upon a strong cold front that will
move across the area this afternoon through Tuesday morning. Strong
thermal gradients will combine with slightly above average moisture
to facilitate heavy snow along a rather narrow band that will form
along and slightly behind the front. North winds are expected to
gust into the range of 40 to 50 mph, with the highest wind speeds
likely to occur within the Red River Valley.
Snowfall totals will vary substantially depending upon the spatial
placement of the heaviest band of snow. Snowfall rates of 1 to 2
inches per hour are well supported by HREF members including HRRR
and NAMNest, which push through the area starting after midnight and
persist through around sunrise. Snowfall totals will be directly
linked to where this band sets up, with amounts as low as 1 to 2
inches possible on the low end, and upwards of 6 or more inches on
the high end. As of this writing, the majority of HREF members,
CAMs, and global ensemble members are painting a stripe of heavy
snow from southwest to northeast along a line from Valley City
through Lake of the Woods and the Red Lakes Region. This has changed
only slightly over the last 8 hours; however, this band could shift
north or south, thus changing the corridor of heavy snow.
Impacts, where we see heavy snow correlate with 40 to 50 mph wind
gusts, will be pushing into winter storm or blizzard territory.
There is good support for blowing snow and low visibility of 1/4
mile or less, along with drifting snow where this interaction
occurs. The only uncertainty at that point will be the temporal
footprint, which could be less than a few hours due to the
rapid progression of the front. Winds are expected to gust
through much of the morning however, which could extend blizzard
conditions far enough to cause longer lasting impacts through
mid-morning or later where we receive the higher snowfall
totals. Blizzard probability is 80 percent or higher with
active snowfall, but falls to 60 percent after snowfall ends
and we are left with just the wind.
Outside of the heaviest band of snow, the progressive nature of the
cold front will limit snowfall accumulations. A sharp cutoff is
expected between areas with up to an inch or two, and areas with six
or more inches of snow. It is in these areas where we will see
impacts more consistent with a winter weather advisory.
&&
.AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/...
Issued at 530 PM CST Mon Feb 26 2024
Look for conditions expected to rapidly deteriorate late this
evening and into the overnight period. IFR or brief LIFR
conditions are possible as snow and blowing snow accompany a
cold front that will pass through the area overnight. North
winds will pick up rapidly from north to south starting around
03Z and are expected to continue through much of Tuesday. Gusts
up to 40 knots are possible, especially for KGFK and KFAR due
to the tendency for north winds to funnel down the Red River
Valley. Outside the Valley, gusts could reach the 30 to 35 knot
threshold. Blowing snow is expected with this system starting as
early as 04Z and persisting through at least mid to late
morning.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...Winter Storm Warning from 1 AM to 6 PM CST Tuesday for NDZ024-
026>030-038-039.
Wind Advisory from 1 AM to 6 PM CST Tuesday for NDZ008-014>016-
054.
Winter Weather Advisory from 1 AM to 6 PM CST Tuesday for
NDZ049-052-053.
MN...Winter Storm Warning from 1 AM to 6 PM CST Tuesday for
MNZ001>003-005>009-013>017-022-023.
Wind Advisory from 1 AM to 6 PM CST Tuesday for MNZ004.
Winter Weather Advisory from 1 AM to 6 PM CST Tuesday for
MNZ029.
&&
$$
UPDATE...AK
DISCUSSION...Lynch
AVIATION...AK
Area Forecast Discussion
National Weather Service Grand Rapids MI
935 PM EST Mon Feb 26 2024
.KEY MESSAGES...
- Threat of Severe Weather Continues Tonight and Tuesday evening
- Colder Temperatures, Snow, and Gusty Winds Wednesday
- Dry Stretch and Gradually Warming Thursday into Monday
&&
.UPDATE...
Issued at 935 PM EST Mon Feb 26 2024
Very dry air remains in place this evening, evident in 00Z DTX
raob and even in soundings farther southwest such as ILX, DVN and
and SGF where H8 dew pt depressions are still around 15C. This
dry air may be the big limiting factor in convective WAA-related
coverage overnight, although newer RAP guidance is still sending
PWATs near 1" northward toward south cntl/se lwr MI overnight.
The expected steep lapse rates are very evident on the ILX
sounding so little doubt that the elevated instability will be
present overnight, with 700-500 mb lapse rates near 9C supportive
of hail (if storms actually develop). Will leave the going fcst
mostly as is, with highest pops south and east of GRR, peaking
09Z-12Z.
Other limiting factor is that the 45-50 kt southerly low level
jet is in a broad corridor/swath from IN to nrn Lk Huron. A more
ideal situation would be to have a convergent leading edge (or
"nose") of a low level jet pointed at the area later tonight and
that does not appear to be the case.
&&
.DISCUSSION...
Issued at 345 PM EST Mon Feb 26 2024
- Threat of Severe Weather Continues Tonight and Tuesday evening
We are still expecting two rounds of thunderstorms both with a risk
of severe weather. The first occurs tonight with the initial surge of
moisture and instability. The threat tonight is centered in the 1am
to 7am time frame and for the most part will be a hail threat.
Tonight`s storms will fire on a 50 knot low level jet and be working
on 1,000-2,000 j/kg of MUCAPE. A weak shortwave at 500mb is the
impetus for convection. Based on the HREF showing multiple runs now
of storms firing overnight and sweeping east late, we feel this is
the likely morphology with this initial event. The updraft helicity
swaths within the HREF tell the story that enough shear is present
(40 knots) for rotating updrafts centered between 1am-7am or maybe
even 8am. The area of concern will be the southeast CWA from GRR to
the south and east. Given the shear and instability severe hail is
certainly possible with the stronger updrafts.
The second round of storms looks to potentially be the more
impactful. We continue to lean on the HREF for guidance as it us
usually always the best convective guidance we have. It continues to
show a severe threat Tuesday evening from at the earliest maybe
around 600pm in far Southern Lower Michigan to 2am or 3am Wednesday
morning before the convection sweeps off to the east. All severe
weather hazards are in play with wind and hail being the main threats
but we cannot rule out an isolated tornado as well.
As a deep trough swings through the plains another shortwave aloft
will move through our area Tuesday evening. A low will be working
northeast through the area moving from IL to northern Lake Huron by
Wednesday morning. Models have remained steadfast that this will be a
formidable low reaching mid 980s mb depths by 7am on Wednesday. As
such significant moisture levels will be pulled into far Southern
Lower Michigan by February standards. Surface dew points will reach
the mid 50s F and 850mb dew points will be at similar values. These
values are very elevated obviously for February. That moisture
combined with strong wind fields will set the stage for a round or
two of convection Tuesday evening. MUCAPE values in the HREF reach
2,000 j/kg. 2,000 MUCAPE values is strong almost any time of the
year, but when combined with the wind fields of a deepening February
system the concern level is raised. 40-60 knot low level jet winds
and similar values in the mid levels will provide rotating storms.
0-6km shear values are strong near 60 knots. A 200 knot jet core in
the Plains will put us in the left exit region of the jet streak
providing strong lift for updrafts.
As for the details of the Tuesday evening threat we expect storms to
break out in the late afternoon to our south and southwest and sweep
northeast through the area during the evening and overnight. Linear
bows and lines will have the potential to produce wind damage and the
strong updrafts will also be capable of hail to severe levels. HREF
updraft helicity swaths are strong and have values capable of all
hazards. In regard to the tornado threat it will likely come down to
where the warm front is around 6pm-10pm time frame as the low moves
northeast pushing the warm front with it. If storms interact with
that boundary an isolated tornado cannot be ruled out.
Temperatures plunge overnight Tuesday night after the convection
goes east. Precipitation will be switching over to snow as the
temperature plunge commences.
- Colder Temperatures, Snow, and Gusty Winds Wednesday
The upper level trough with the vorticity maximum and surface front
move through Wednesday morning. This will bring plenty of lift along
with a surge of cold air. 925mb temps quickly fall to around -10C
behind the front with a transition to all snow expected early
Wednesday morning. Winds also increase behind the front with
northwest winds gusting around 30 to 40 mph. The combination of
falling temperatures, snow, and gusty winds will likely impact the
Wednesday morning commute. There is some uncertainty in exact
snowfall amounts at this time as seen within the ensembles and
probabilistic fields. Amounts range generally in the 25th to 75th
percentiles of amounts less than an inch to around an inch to 3
inches with the highest amounts along the lakeshore and along and
north of M-20. Dry conditions look to return Wednesday evening with
winds gradually becoming lighter Wednesday night into Thursday.
- Dry Stretch and Gradually Warming Thursday into Monday
Upper level ridging and subsidence move in for Thursday and continue
into the beginning of next week. The only hiccup we`ll have to watch
is a shortwave that moves through Friday that could bring some rain
to the area. Within the ridge temperatures warm once more with highs
starting in the mid to upper 30s Thursday, reaching the mid to upper
50s by Friday, and then 60s once more for Sunday and Monday.
&&
.AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/...
Issued at 720 PM EST Mon Feb 26 2024
Low level wind shear developing this evening as southerly winds
increase to nearly 50 kt just above the sfc whereas sfc winds will
only be 10-15 kts. Threat ending early Tuesday as the low level jet
departs to the east.
Conditions remaining VFR for much of tonight although scattered
tstms becoming possible after 06Z, mainly south and east of GRR.
Confidence in overnight storm potential/coverage remains on the low
side so stuck with the PROB30 thunder risk which was already in the
earlier 18Z TAFs. However did remove the thunder chance at MKG as
most guidance indicates it will be east of there if it occurs. Any
late night storms which develop will be capable of producing IFR
vsbys in briefly heavier rain and potentially some hail as well, and
will exit to the east by 12-13Z Tue.
A period of IFR cigs and light fog/mist is expected late tonight
into Tuesday morning related to the incoming warm front and higher
dew points. LIFR cigs/vsbys cannot be ruled out at MKG due to the
rising dewpoints coming across the cold waters of Lk MI.
VFR expected Tuesday afternoon as warm front lifts north, with next
round of showers and storms holding off until after 00Z Wed.
&&
.MARINE...
Issued at 345 PM EST Mon Feb 26 2024
We have an ongoing Small Craft Advisory which continues through
300pm on Tuesday. This timing looks good, although it may go an
hour or two longer in length. We will monitor this. Right now
the Muskegon Buoy and Southern Lake Michigan buoy are only
showing 1-2 footers. The strongest winds and therefore largest
waves should be tonight though based on BUKFIT overviews. Winds
in this advisory will be 15-25 knots with waves of 3-5 feet.
The bigger event which may reach gale force will occur Tuesday
overnight through Wednesday midday. At this point not enough
confidence to issue a Gale Watch in the nearshore waters but it
will be close. Models are indicating winds in the 30-35 knot
range which is right on the fence for a Gale Watch/Warning. Very
strong cold air advection occurs with these northwest winds so
waves are going to jump. Waves look to peak Wednesday morning in
the 9 to 13 foot range.
&&
.CLIMATE...
Issued at 312 AM EST Mon Feb 26 2024
Record high maximums and minimums are possible Tuesday.
GRR LAN MKG AZO
High Maximum 67-1976 64-1867 62-1976 67-1976
High Minimum 37-2018 38-2018 35-1999 43-1987
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...None.
MARINE...Small Craft Advisory until 3 PM EST Tuesday for LMZ844>849.
&&
$$
UPDATE...Meade
DISCUSSION...Duke/RAH
AVIATION...Meade
MARINE...Duke
CLIMATE...04
Area Forecast Discussion...Updated
National Weather Service Lincoln IL
814 PM CST Mon Feb 26 2024
.KEY MESSAGES...
- Another day of record warmth is expected on Tuesday, along with
breezy southerly winds gusting 30 to 40 mph in the afternoon.
- Scattered severe storms are possible Tuesday evening, mainly
between 6 PM and midnight.
- A sharp cold front moves through Tuesday night, resulting in
dramatically cooler temperatures on Wednesday as highs struggle
to reach the mid 30s. There is a 40-60% chance for a band of
snow early Wednesday morning after the front passes.
&&
.UPDATE...
Issued at 814 PM CST Mon Feb 26 2024
Made some minor tweaks to hourly winds/dewpoints this evening to
better depict a surge of higher momentum air flowing northward
along the I-55 corridor. Southerly winds have recently gusted
30-40mph at K3LF/KSPI/KTAZ and have now increased at KAAA/KDEC as
the jet lifts northward. HRRR shows the stronger winds passing
through KBMI/KCMI later this evening before exiting into northern
Illinois toward midnight. The increased southerly flow has brought
a distinct increase in boundary layer moisture, with surface
dewpoints increasing from the middle 40s to the middle 50s. Skies
remain mostly clear along/west of I-55...with low/mid clouds
quickly increasing further east. CAMs continue to suggest a few
showers/thunderstorms will develop along/east of I-57 over the
next few hours and linger until around daybreak. Previous forecast
had a good handle on the PoPs, so made little change to the rain
chances across the E/SE KILX CWA tonight.
Barnes
&&
.DISCUSSION...
Issued at 241 PM CST Mon Feb 26 2024
A sfc low currently over the northern Plains will deepen and
progress east towards the Great Lakes over the next 48 hours,
resulting in several noteworthy forecast considerations across
central IL during that time. The forecast highlights include:
record setting warmth and breezy winds through Tuesday, scattered
showers/storms east of I-57 tonight, the potential for severe
thunderstorms Tuesday evening, then a dramatic cool down late
Tuesday into Wednesday, which could be accompanied by a band of
snow behind the cold front.
1) RECORD WARMTH & BREEZY WINDS
With clear skies and persistent southerly flow, high temperatures
had no trouble exceeding both the forecast and the record values
today, with all three of our official climate sites setting record
highs today. There should be more cloud cover around tomorrow,
which adds a layer of uncertainty to exactly how warm the temps
will climb, but the expectation is that we`ll once again set
records with highs in the mid to upper 70s.
As the sfc low continues to deepen and shift closer to the Great
Lakes on Tuesday, southerly winds will increase, with sustained
winds approaching 20 mph and gusts of 30-40 mph. Forecast
soundings do suggest the potential to sporadically mix down gusts
near wind advisory criteria (45 mph) Tuesday afternoon, especially
south of I- 70, however, probabilistic guidance did not have a
strong signal for exceeding 45 mph gusts. Also, we tend to
underperform wind gust guidance in WAA setups as mixing is not as
robust and can be stymied by cloud cover. Despite the stronger
winds, fire danger should be lower than Monday as low-level
moisture advection results in increasing RH.
2) SCATTERED SHOWERS/STORMS EAST OF I-57 TONIGHT
Low-level WAA is expected to increase tonight, focused across E
IL/IN/KY. This forcing could help kick off a few showers and
storms. There is decent elevated instability present, with the
HREF showing mean MUCAPE values of 1000-1500 J/kg, which could
support an isolated hail threat, however, activity quickly pushes
east of our area and may do so before storms have a chance to
organize. The latest SPC outlook for tonight does not include a
threat for the ILX CWA, but there is a marginal risk (level 1 of
5) for areas to the east. The primary time frame to keep an eye
out for any activity in our CWA tonight is be between 10 PM/04z
and 2 AM/08z.
3) TUESDAY EVENING SEVERE STORM POTENTIAL
There is potential for severe thunderstorms Tuesday evening/night.
Models continue to show a favorable parameter space, with robust
instability (1000+ J/kg of SBCAPE) and deep layer shear (50+
knots). However, stout capping will be in place through much of
the day, and even the most bullish members of the 26.12z HREF do
not show storm initiation until after 5 PM. The cap strength does
vary by model, with the GFS showing 850mb temps around +15 degC
while the RAP/NAM are warmer, approaching +18 degC. Even with
favorable jet dynamics and strong forcing along a mesoscale
boundary, capping as strong as that in the latter solution could
limit convective coverage, so observations and model trends
regarding the cap strength will need to be watched into tomorrow.
There is still some variation in the CAMs as to how this event
plays out. The more common solution is for t-storm development
along a dryline as it shifts into central/eastern IL tomorrow
evening. In this solution, low-level wind profiles have less
curvature and at least initially hail looks like the primary
threat, although if there is sufficient forcing to transition to a
linear storm mode the wind threat could increase into the
evening. The 12z NAMNest puts forth a different, outlier
solution, showing a secondary sfc low tracking across the CWA with
storms initiating further west near a triple point. This solution
would have backed sfc winds and greater tornado potential, but
again this solution is an outlier. With these solutions in mind,
storms appear most likely in areas east of I-55, with less
certainty to storm development further to the west. Overall,
thoughts on the threat timing haven`t changed too much, with 6 PM
Tues to 12 AM Wed the most likely timeframe for any severe storms.
The Storm Prediction Center has maintained a slight risk (level 2
out of 5) of severe storms for nearly all of the ILX CWA.
4) DRAMATIC COOL DOWN/SNOW CHANCES
A sharp cold front crashes through the ILX CWA Tues night into
Wed, ushering in significantly cooler air. 850mb temps are
forecast to fall nearly 25 degrees in a span of 24 hours (from
around +15 degC on Tues to around -10 degC on Wed), and as a
result sfc highs could struggle to reach freezing just a day after
near record warmth. Winds behind the front will be quite breezy
as well, with sustained northwest winds around 20 mph and gusts
30-40 mph. That will result in wind chill values generally in the
teens during the day Wednesday.
Models are hinting at a band of snow developing behind the front,
owing to f-gen forcing. This feature will trail the sfc cold
front by a few hours, and guidance currently suggests it impacts
areas west of I-55 between midnight and 6 or 7 AM Wednesday. Will
have to keep an eye on the potential for minor snow accumulations
(~1") from this band, but warm ground temps and the progressive
nature of the band are both factors that would limit
accumulations.
Beyond Wednesday, another warm up appears in store, with temps
climbing back into the 60s/70s by the weekend.
Erwin
&&
.AVIATION...0Z TAFS THROUGH 00Z WEDNESDAY/...
Issued at 544 PM CST Mon Feb 26 2024
S/SE winds will continue to gust over 20kt through this evening
before veering to S/SW toward midnight. A strong S/SW breeze
will then persist for the remainder of the 00z TAF period. A
blanket of high clouds will be observed across the entire area
this evening: however, models continue to suggest lower clouds
developing east of the I-55 corridor overnight into Tuesday
morning. The greatest probability for MVFR ceilings will be at
KCMI between 08z and 13z, although these lower clouds could
linger longer. The next aviation forecast challenge will be
trying to pin down the timing/location of scattered convection
along/ahead of a cold front Tuesday evening. With precip not
likely to impact any of the central Illinois terminals until
after 00z Wed, have opted to leave mention out of the forecast
at this time.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
Area Forecast Discussion
National Weather Service North Platte NE
539 PM CST Mon Feb 26 2024
.KEY MESSAGES...
- Long-track range fires are underway in Logan and Custer
counties. The town of Stapleton is being evacuated. Winds will
subside with the approach of sunset lessening the spread of
these fires.
- An arctic blast is heading toward Nebraska. Temperatures
Tuesday afternoon will be 50 to 60 degrees colder than Monday
afternoon.
- The models show another bout of low 850-700mb RH, between 20
and 40 percent, Wednesday through Saturday. Red Flag criteria
will be probably be reached, most likely Saturday, but
potentially Thursday and Friday.
&&
.SHORT TERM /THROUGH TUESDAY NIGHT/...
Issued at 420 PM CST Mon Feb 26 2024
The RAP and HRRR models are the basis for falling temperatures
throughout the day Tuesday. These two models suggest mid afternoon
temperatures in the teens across nrn Nebraska and 20s across srn
Nebraska. The HRRR was the basis for scattered fast moving snow
showers associated with strong frontogenesis and moisture below
700mb. The fast motion will limit snow accumulations to just a trace
to less than an inch. It`s worth noting several models, the
majority, show a dry slot of air between 750-700mb nullifying snow
accumulations. So, the snow forecast is generous with 20-40 POPs in
place.
The powerful arctic blast moving in Tuesday will support a 20mb sfc
pressure rise in 12 hours. The wind forecast of sustained winds 20
to 30 mph is somewhat generous given the 500m AGL winds suggest 20
to 25 mph winds. The wind gust tool suggested gusts of 35 to 45 mph,
about 5 mph stronger than the HRRR and RAP model wind gusts. Thus,
the wind gust forecast is also generous, especially since the h850mb
winds are in the 30 to 40kt range. All of this is out of respect of
the very strong sfc pressure rises predicted to move through
Nebraska Tuesday.
The arctic sfc high pressure will be moving overhead Tuesday night
and the guidance blend is in place for lows in the teens and single
digits. Winds will be light, 850-300mb RH around 30 percent and
precipitable water falls to 0.10-0.15 inches. All of this suggests
the potential for strong radiational cooling.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
Issued at 420 PM CST Mon Feb 26 2024
Once again, it`s one-and-done with this arctic high pressure
system. Milder air will begin moving in Wednesday with high
temperatures in the 40s. H850mb temperatures will be in the single
digits. The warming trend, or warm air advection, strengthens
Thursday with h850mb temperatures warming to around 10C. This
supports the highs in the lower 60s.
Further warming at the h850mb level is expected Friday as
temperatures at that level rise to around 15C. This warm air will
remain in place Saturday followed by a strong cold front Sunday. The
blended forecast temperatures Thursday through Saturday get a nudge
from the NBM 50th percentile for highs in the 60s to lower 70s.
There`s been speculation by the NBM that highs around 80 are
possible Saturday and that certainly is possible given h700mb warm
to 2-4C. Later forecasts may mark up highs further.
Rain changing to snow is possible with the passage of a cold front
and a deep upper low late Sunday into Monday. The upper low and best
dynamics will pass north and west of the wrn and ncntl Nebraska.
Nebraska will be in a 700mb warm air advection zone which makes the
forecast tricky as there is the potential for dry air to get
advected from the south.
&&
.AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/...
Issued at 524 PM CST Mon Feb 26 2024
Strong, gusty westerly winds up to 35kts will remain possible
through sunset across western and central Nebraska (including
KLBF) before quickly subsiding to 10kts or less overnight. For
northern Nebraska, westerly winds up to 25kts will continue
tonight ahead of a frontal passage expected to reach KVTN by 08Z
Tuesday. This FROPA will bring an abrupt wind shift towards the
north/northwest with strengthening winds directly along and
behind the FROPA gusting 35 to 40+ kts Tuesday afternoon. The
front is expected to reach KLBF by 12Z Tuesday morning with
strengthening winds behind it. This frontal passage will also
bring MVFR/IFR ceilings for Tuesday afternoon and the potential
for some snow showers. Confidence on timing and intensity of
snow showers remains meager, thus opt to not include with this
TAF issuance. However, inclusions and amendments will be
possible should confidence increase.
&&
.FIRE WEATHER...
Issued at 420 PM CST Mon Feb 26 2024
The models show another bout of low 850-700mb RH, between 20 and
40 percent, Wednesday through Saturday. This will lead to sfc
RH around 20 percent but possibly lower Saturday when warm air
advection will peak. The wind forecast is somewhat uncertain
for a number of reasons. The sfc low pressure is a bit higher
than the 992mb currently underway and winds aloft are slightly
weaker. Plus, the winds Saturday are southwest vs west for the
ongoing setup. The feeling is Red Flag criteria will be reached,
most likely Saturday, but potentially Thursday and Friday.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
Red Flag Warning until 9 PM CST /8 PM MST/ this evening for
NEZ204-206-208>210-219.
&&
$$
SHORT TERM...CDC
LONG TERM...CDC
AVIATION...Viken
FIRE WEATHER...CDC
Area Forecast Discussion...Updated
National Weather Service Saint Louis MO
948 PM CST Mon Feb 26 2024
.UPDATE...
Issued at 945 PM CST Mon Feb 26 2024
Low level jet (40 to 50kts) ramping up across the region this
evening with decent instability, MU CAPES of 500 to 1000 J/kg as
well as steep mid level lapse rates of 8-9C/km. Isolated showers
have begun to develop over western MO, just south of Kansas City
on the nose of the low level jet. As the jet veers from southwest
to west overnight, the activity will slide east across the region,
mainly along and south of the I-70 corridor. So added mention of
isolated/scattered showers and storms between 05z and 12z. With
convection being elevated in nature, the main threat will be
marginally severe hail and potentially a few stronger wind gusts
before the storms exit the area.
Byrd
&&
.KEY MESSAGES...
- Another afternoon of critical fire danger is expected on
Tuesday, mainly in parts of central Missouri. A Red Flag
Warning has been issued for these areas where burning of any
kind is once again highly discouraged.
- Record-breaking warmth is forecast on Tuesday, followed by a
drastic cooldown (high temperatures 40-45 degrees cooler) for
Wednesday thanks to a potent cold front.
- There remains a threat for strong to severe thunderstorms late Tuesday,
but there remains a lot of uncertainty with when and where
thunderstorms will develop.
- An area of light snow is forecast behind the cold front Tuesday
late evening into the early overnight hours. Amounts of 0.5-1.0"
are forecast, mainly in parts of northeast Missouri and west-
central Illinois.
&&
.SHORT TERM... (Through Late Tuesday Night)
Issued at 243 PM CST Mon Feb 26 2024
(Tonight)
Mild temperatures along with southerly winds are forecast overnight
tonight. Lows are only forecast to drop back into the upper 40s to
upper 50s across the bi-state region. These readings are about 10-20
degrees warmer than this morning.
(Tuesday - Tuesday Night)
A very busy 24 hours of weather complete with critical fire danger,
potential for severe weather, very gusty winds, and accumulating
snowfall are all forecast across the CWA.
A very strong cold front is forecast to gradually move through the
region late Tuesday/Tuesday night. Ahead of the front, another very
warm day is on tap along with gusty south/southwest winds. Highs are
forecast to break records at all three of our climate stations
(KUIN, KCOU, KSTL) and could threaten all-time monthly records for
February. Leaned toward the warmer guidance for tomorrow due to
plenty of sunshine over most of the area, deep mixing, and favorable
surface southwesterly surface winds. These winds will downslope off
of the Ozark Plateau across parts of central, east central, and
southeast Missouri where the warmest high temperatures are forecast
(low 80s). Speaking of winds, model guidance shows unidirectional
flow within the mixed layer with maximum speeds over 45 knots in
parts southeast Missouri and southwest Illinois Tuesday afternoon.
These soundings are favorable for the mechanical transport of these
higher gusts down to the surface. Therefore, have issued a wind
advisory in parts of southeast Missouri and southwest Illinois.
Confidence in convective initiation and location remains very
difficult to discern for tomorrow afternoon/evening. Model guidance
varies sharply with respect to the boundary layer tomorrow as well
as the strength of the cap. The NAM is on one end of the spectrum
showing lesser mixing, higher dewpoints, and a very strong cap (300-
400+ J/kg CIN) centered around 925 hPa. The RAP and the HRRR are on
the opposite end of the spectrum with very deep mixing (up to ~700
hPa), lower dewpoints, and weaker capping. However, dewpoints at the
surface mix out sufficiently to greatly limit instability (even
elevated). The exception would be further to the southeast where a
narrow moist axis (dewpoints above 55F) is likely to exist, but the
question is where is this moist axis located? The odds would favor
parts of southwest/south central Illinois where the combination of
some low stratus in the morning and less downslope off of the Ozark
Plateau should create some type of moisture gradient from
west/northwest to east/southeast. While highly conditional, there
may be enough surface convergence for a very narrow temporal (~21Z-
0Z) and spatial (south-central Illinois) window for convective
initiation. If this does occur, convection may also stay or quickly
move out of the CWA to the northeast. However, any storms likely
would quickly become supercellular given >70 knots of deep-layer
shear with an orthogonal component to the moist axis/boundary. Large
hail and damaging winds would be the main threats. Later on in the
evening, there is a bit more confidence for convective initiation
along the synoptic cold front. While there remains some timing
differences (NAM the slowest), the general consensus is for the
front to approach the I-44/I-55 corridors in Missouri and Illinois
respectively around 0300 UTC and then clear the CWA to the south and
east around 0600 UTC Wednesday. Deterministic model guidance shows
increasing surface convergence by 0300 UTC. This combined with some
weak mid/upper level diffluence and height falls (cooling aloft)
should help yield at least widely scattered convection by late
evening. This means that storms are most likely in parts of
southeast Missouri and southwest Illinois in the 0300-0600 UTC time
frame, but a slightly faster (slower) front would shift the threat
further to the southeast (northwest). Damaging winds are the main
threat, though isolated tornadoes are also possible given very
strong 0-1km shear/helicity values.
Meanwhile, further northwest, an area of precipitation is forecast
to move into parts of northeast Missouri between 0400 and 0600 UTC.
This precipitation should be snow, as temperatures behind the front
crash into the 30s. Temperatures should continue to fall overnight
into the upper 10s to 20s for northwestern sections of the forecast
area. Deterministic guidance shows strong low/mid level
frontogenesis moving gradually east/southeast overnight before
weakening sharply between 0900 and 1200 UTC Wednesday. There is even
some negative EPV (reduced stability) above this layer of strong
frontogenesis, which suggests some enhanced banding at least of
snowfall. The signal is pretty strong/consistent, but there is some
areal differences of where this band of relatively higher snowfall
totals will reside. Most areas will see less than 1", but wouldn`t
be surprised to see a narrow axis with amounts of to 2" somewhere
tomorrow night. While surface temperatures at the onset of snow will
likely be near or just above freezing, they should drop back into
the mid to upper 20s. When temperatures get that cold, snow at
least begins to stick on everything (particularly at night), so
would not be surprised to see at least some brief/light
accumulations on untreated surfaces in/around the "heaviest" of the
snowfall.
Gosselin
&&
.LONG TERM... (Wednesday through Next Monday)
Issued at 243 PM CST Mon Feb 26 2024
(Wednesday - Wednesday Night)
What a difference a day makes! After daily record highs expected on
Tuesday, high temperatures are forecast to be some 30-40+ degrees
colder on Wednesday behind the cold front. Gusty northwest winds
will make it feel quite a bit colder, in the 10s/20s in the morning.
Definitely a shock to the system after the 70s to low 80s on
Tuesday. Lows Wednesday night are expected to be in the low to mid
20s areawide, or about 5-10 degrees below normal for the end of
February.
(Thursday - Next Monday)
A general warming trend is forecast for the end of the work week
with well-above normal high temperatures expected next weekend into
early the following week.
In terms of precipitation chances, ensemble guidance probabilities
for measurable rainfall have increased for the Thursday night/Friday
night time period. There remains some subtle timing/location
differences, but the highest probabilities for rainfall (60-80+%)
are in parts of southeast Missouri and southwest Illinois. NBM
probabilities for precipitation are quite a bit less (20-40%) due to
these differences, but if this signal maintains itself, PoPs would
climb with future forecast updates. Light is the key word however,
as probabilities for at least a tenth of an inch drop sharply (10-
30%). In other words, this system may bring some light rainfall to
at least parts of the area but it does not appear to be anything
substantial to help with the persistent dryness since the beginning
of February.
Another chance of showers and some thunderstorms look increasingly
likely Sunday night into Monday. This would be associated with
anomalous midlevel troughing coming out of the Rockies and a surface
cold frontal passage. This far out, there is unsurprisingly quite a
bit of uncertainty with any specifics, but the large-scale pattern
appears favorable for at least a low threat for strong-severe
thunderstorms regionally.
Gosselin
&&
.AVIATION... (For the 00z TAFs through 00z Tuesday Evening)
Issued at 525 PM CST Mon Feb 26 2024
VFR flight conditions through the forecast period. Main issue will
be the winds. Gusty south winds will diminish at onset of
forecast period. For tonight, despite strong winds aloft, do not
expect any issues with LLWS as surface winds will remain high
enough to offset that. On Tuesday, winds will pickup by mid
morning with gusts up to 30kts at times from midday through the
afternoon hours ahead of a cold front. As the front begins to
move through the region, winds will veer to the southwest to west.
Byrd
&&
.FIRE WEATHER...
Issued at 329 AM CST Sun Feb 25 2024
Warm, very dry, and breezy conditions today have prompted the
expansion of the Red Flag Warning to include a greater portion of
Missouri and into western Illinois. With a southerly wind today,
downsloping conditions north of the Ozarks will set up strong and
deep mixing across the Missouri River Valley where we expect the
warmest temperatures and driest air. Further east it will still be
warm, dry, and breezy, leading to Elevated Fire Danger but we will
likely fall short of critical conditions.
Better moisture begins to move into the area tonight, so while we
are even warmer in some areas on Tuesday the humidity won`t be as
low. Relative humidity values are likely to fall below 30 percent
across central Missouri again with winds even a bit stronger out
of the southwest gusting to 35 mph. Elevated Fire Danger is likely
in this area again. Thunderstorm chances Tuesday night are limited
and most likely across southeast MO and southern IL.
A very cold Arctic air mass moves in behind a strong cold front
Tuesday night, shifting winds to the northwest. As this air mass
leaves on Thursday we begin to gradually warm back up, but
humidity remains very low in the wake of the Arctic air. Thursday
may have the lowest humidity of the week although winds will be
lighter out of the south and temperatures only in the 40s to low
50s.
Kimble
&&
.CLIMATE...
Issued at 257 PM CST Fri Feb 23 2024
Record climate information for St. Louis, MO (KSTL); Columbia, MO
(KCOU); and Quincy, IL (KUIN).
-------------------------------------------
Daily Record High Temperatures:
|__TUE 2/27___|
KSTL 79 F (1981)
KCOU 75 F (1976)
KUIN 73 F (1976)
-------------------------------------------
February Record High Temperatures:
KSTL 85 F (2/29/1972)
KCOU 82 F (2/29/1972)
KUIN 77 F (2/20/2017)
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...Wind Advisory from noon to 6 PM CST Tuesday for Crawford MO-Iron
MO-Madison MO-Reynolds MO-Saint Francois MO-Sainte
Genevieve MO-Washington MO.
Red Flag Warning from 11 AM to 7 PM CST Tuesday for Boone MO-
Callaway MO-Cole MO-Crawford MO-Dent MO-Franklin MO-
Gasconade MO-Moniteau MO-Montgomery MO-Osage MO-Warren MO.
IL...Wind Advisory from noon to 6 PM CST Tuesday for Randolph IL.
&&
$$
WFO LSX
Area Forecast Discussion
National Weather Service Blacksburg VA
622 PM EST Mon Feb 26 2024
.SYNOPSIS...
A large low pressure system will cross the United States tonight
through Wednesday, resulting in scattered showers Tuesday, and
numerous showers on Wednesday, as a strong cold front passes through
the area. Gusty winds are expected Wednesday and Wednesday night with
this system as well. Temperatures will be unseasonably mild ahead of
the front, and return to near normal as dry high pressure builds
into the area for Thursday.
&&
.NEAR TERM /THROUGH TUESDAY/...
As of 610 PM EST Monday...
Key Messages:
1. Scattered light showers ending this evening, but more
scattered showers Tuesday
2. Temperatures above normal.
Actually had a few cloud to ground lightning strikes near the
office around 530pm. Mesoanalysis showed SBCAPE reached above
100 J/kg, and just enough heating and cooler air aloft to
trigger some growth in the clouds and result in the lightning.
Showers will head east and out of the forecast area this evening
and mainly be confined along an area near the Roanoke River.
Previous discussion...
Have adjusted timing and location of scattered showers based on
radar trends and the 12Z/13Z HRRR guidance. No changes needed to
temperatures at this time.
Scattered light showers will continue over the area this
afternoon but while the overall region of lift and moisture
tracks to the northeast. Expecting a break in the precipitation
and clouds overnight.
Southwest winds ahead of the large low pressure system in the
Central Plains will result in warmer temperatures and more moisture
across the region on Tuesday. Warm air advection and isentropic lift
will generate rain across the area. Increasing southwest wind speeds
just above the surface will also result in gusty winds in the
piedmont. Bufkit was showing enough mixing to have wind gusts
potentially as high as 25 to 35 mph range at Lynchburg, Farmville,
and Danville. Some question about the amount of mixing for the lower
elevations, but ridges will tap into a 40 to 60 knot low-level jet.
Warm air advection and wind will also inhibit much of the
temperature drop tonight, even with the clouds becoming scattered in
the evening. Lows tonight will be 10 to 20 degrees above normal. The
clouds return early on Tuesday, but because of the mild temperatures
to start the day, highs will still rise into the 50s to mid 60s.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/...
As of 100 PM EST Monday...
Key Messages:
1. Widespread rain showers Wednesday into early Thursday morning.
2. Strong and gusty winds on Wednesday.
3. Warmer Wednesday, colder on Thursday.
A 500mb trough will continue to track across the US through the
first half of the work week, with its associated surface low
pressure system and trailing cold front reaching the eastern US by
Wednesday. Strong southwesterly flow will bring in warmer and
moisture-rich air to the region, increasing temperatures and
dewpoints through Wednesday. Temperatures will be warmest on
Wednesday, with probabilities of maximum temperatures exceeding 60
degrees between 90% to 100% for most locations outside of the higher
elevations along and west of the Blue Ridge.
The main front will cross the region Wednesday afternoon/evening,
bringing an area of rain showers, potentially moderate to heavy,
reaching the western part of the forecast area as early as Wednesday
morning, although the heaviest rain showers are more likely later in
the day. There is a slight chance for thunderstorms, especially west
of the Blue Ridge, during Wednesday afternoon, with the strong
forcing and low level wind shear. The limiting factor will be
instability, but there is potential for CAPE to reach up to 200 to
300 J/kg by the early afternoon. The greater instability and thus
greater potential for severe weather is farther to the west in the
Ohio Valley region. However, given the increasing dewpoints, forcing
from the front and upper trough, and low level wind shear, the
potential for thunderstorms in the southeast West Virginia,
southwest Virginia, and northwest North Carolina cannot be ruled out.
Behind the front, cold air advection and strong pressure rises will
lead to strong and gusty winds Wednesday afternoon through early
Thursday morning. Winds will decrease through Thursday as the
pressure gradient relaxes between the exiting cold front and
approaching surface high pressure. Winds at 850mb reach 50 knots
just out ahead of the front, so will likely also see gusts in the 20
to 30 knot range in the east, and up to 35 knots along the higher
terrain Tuesday night into Wednesday morning, but the stronger winds
and gusts are expected Wednesday night into Thursday morning.
Temperatures drop on Thursday following the front, so some of the
lingering showers in the western mountains may transition to snow
showers. However, this front moves eastward quickly, bringing an end
to the precipitation by midday Thursday.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
As of 100 PM EST Monday...
Key Messages:
1. Precipitation chances throughout weekend.
2. Low confidence on coverage, timing, and amounts of precipitation.
3. Temperatures trend warmer through weekend.
Surface high pressure builds back into the area briefly following
the frontal passage in the short term forecast period, before
shifting east by Friday and Saturday. There are considerable
differences among long range deterministic guidance for the next
approaching system that may bring precipitation to the area. A
southern stream shortwave trough develops over the southern Plains
and pushes eastward through the week. Some deterministic models have
this tracking farther north, which would result in more rain to the
area, whereas others keep it across the south, which would mean
lesser coverage and intensity of rain, also considering the dry
airmass that will be overhead by Friday. Models show this low
eventually moving offshore and deepening some time during the
weekend, but again, little to no agreement on timing between the
global models. As this system comes from the southern US, expecting
temperatures to be on a warming trend through the weekend, based on
increasing positive 850mb temperature anomalies shown in the
ensemble guidance.
&&
.AVIATION /23Z MONDAY THROUGH SATURDAY/...
As of 612 PM EST Monday...
Mainly VFR expected through the 18z Tuesday, but should see
ceilings lower Tuesday afternoon to 1-3kft, though some models
hint at sub-1kft in the piedmont/Roanoke, but confidence is low.
Showers will be scattered around Tuesday with best chance from
15z-20z from west to east.
Southwest flow increases such that there will be gusty winds to
20-25kts Tuesday.
Low level winds will increase, but latest guidance suggests that
LLWS will be iffy at the terminals, but something to be mindful
of overnight if flying.
Average confidence in ceiling, visibility, and wind.
AVIATION OUTLOOK...
There will be a break in the rain Tuesday night and clouds will
become scattered.
Gusty wind will continue Tuesday night and especially Wednesday
as a strong cold front approaches. Winds will be S to SW ahead
of the front and turn to the NW as the front crosses the area
Wednesday. Showers with MVFR conditions will cross the area
along with the front. Thunderstorms also possible.
Return to VFR Wednesday night and Thursday behind the front,
except for MVFR upslope clouds and rain and snow showers at BLF
and LWB. A system will be developing in the Southern Plains and may
bring some showers to the our region Saturday wit sub-VFR.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...None.
NC...None.
WV...None.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS/WP
SHORT TERM...AS
LONG TERM...AS
AVIATION...AMS/WP
Area Forecast Discussion
National Weather Service Topeka KS
549 PM CST Mon Feb 26 2024
.KEY MESSAGES...
- Updated Aviation discussion for the 00Z TAFs.
- Record warmth today and very dry with elevated fire danger
- Strong cold front Tuesday afternoon leads to gusty winds. Red Flag
Warning has been issued for Lyon, Coffey, and Anderson Counties.
- Brief light snow possible Tuesday night followed by decreasing
winds into Wednesday with much colder temperatures.
- Thursday brings a return to more widespread fire weather concerns.
&&
.DISCUSSION...
Issued at 257 PM CST Mon Feb 26 2024
Bigger changes are ahead and the upper air pattern is indicative of
this as of 20Z this afternoon. Mainly zonal flow is over the
forecast area, but a water vapor loop shows that the cut-off low
that has been off the CA coast is starting to phase into the
northern stream trough, which is amplifying over the PNW. At the
surface, low pressure is centered on the northern Plains. WAA today
has helped temperatures surge into the upper 70s with some low 80s
being observed as well, setting new daily records at both TOP and
CNK for today. With only a short time window left for peak heating,
there isn`t much time left to make a run at the warmest February
temperature, but it may come close.
Focus turns to the strong system set to move through the area
Tuesday. While there are still some timing discrepancies with the
passage of the cold front (for example, the 15Z RAP is on the slower
side), we`re starting to see better consensus among the ensemble
solutions and confidence is increasing now that we`re within range
of CAMs. The quicker trend has continued into this forecast cycle,
bringing the front into our north central KS counties by about noon,
then bisecting the CWA by mid-afternoon, and then pushing all
the way through by 5 or 6pm. As such, counties south of I-35
stand the best chance of reaching the upper 70s or even low 80s
again given this is the area that would see the strong southerly
winds (and associated WAA) the longest. North central KS should
reach the upper 50s to low 60s by midday before falling the
rest of the afternoon as CAA takes over behind the front. The
strongest winds are still anticipated after frontal passage
given rapid pressure rises, and could be near advisory-level
mainly for sustained winds from mid/late afternoon into the
evening. However, even the HREF 75th percentile is a bit spotty
on that potential and would like to see those winds on a more
widespread basis and for a longer period of time before issuing
any headlines, so have opted to hold off for now.
Most short-term guidance is showing a brief period of banded
snowfall behind the front Tuesday night, and forecast soundings
support all snow with this precip. The quick-moving nature of this
should keep amounts light with up to a dusting at best, though warm
ground temperatures should minimize any impacts. Much colder
temperatures move in as lows fall to the teens to low 20s by
Wednesday morning. Even though winds diminish into the daytime
hours, CAA still will keep temperatures below average in the upper
30s to low 40s for most.
Active pattern continues the rest of the week as a shortwave trough
passes just south of the area on Thursday, leading to another breezy
day. Temperatures moderate and warm up again towards the end of the
week, back into the 70s for highs by next weekend.
&&
.AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/...
Issued at 541 PM CST Mon Feb 26 2024
Expect VFR conditions for the next 24 hours. light southwest
surface winds tonight will increase to 12 to 14 KTS with gusts
of 20 to 24 KTS through the mid and late morning hours into the
early afternoon hours. A cold front will switch winds to the
northwest after 20Z TUE with slightly higher gusts expected.
&&
.FIRE WEATHER...
Issued at 257 PM CST Mon Feb 26 2024
Despite less wind today, very low RH in the 10-20% range today will
keep elevated fire danger through the afternoon. Have continued to
lean on the NBM 10th percentile for dew points into Tuesday. With
the warmest temperatures expected in Lyon, Coffey, and Anderson
Counties, combined with gusty southwest winds to 25-30mph and RH
down to 20%, have opted to issue a Red Flag Warning for this area
Tuesday afternoon. Conditions will not be good for burning
regardless area-wide as those gusty southwest winds will shift to
the northwest and become stronger behind the cold front, sustained
15-25mph gusting up to 40mph in the evening hours.
Thursday looks to be perhaps a more concerning fire weather day area-
wide with RH dropping as low as 18-25% and strong southwest winds
strengthening as a lee sfc trough develops. Sustained speeds of 20-
25mph with gusts of 35-45mph are currently forecast, and fuels are
anticipated to only continue to dry out and cure throughout the week.
&&
.CLIMATE...
Updated at 1145 AM CST Mon Feb 26 2024
Record High Forecast High
Topeka Feb 26 78 in 1896 83
Feb 27 76 in 1932 75
Concordia Feb 26 79 in 1896 83
Feb 27 77 in 2016 64
Record Warmest February Temperature
Topeka 84 on Feb 29, 1972
Concordia 86 on Feb 29, 1972
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
Red Flag Warning from 11 AM to 6 PM CST Tuesday for KSZ054-
KSZ058-KSZ059.
&&
$$
DISCUSSION...Picha
AVIATION...Gargan
FIRE WEATHER...Picha
CLIMATE...Poage