Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 02/10/24
Area Forecast Discussion
National Weather Service Austin/San Antonio TX
532 PM CST Fri Feb 9 2024
...New AVIATION...
.SHORT TERM...
(Tonight through Saturday night)
Issued at 149 PM CST Fri Feb 9 2024
Per midday RAP analysis, a sfc low is currently centered near SE KS,
ahead of broad upper troughing over the western CONUS w/ axis west
of the Four Corners. The upper trough will not eject to the east of
there until Saturday evening. Although some of our western areas are
seeing some sunshine this afternoon, moist SW flow aloft will bring
high cloud cover back this evening and it will remain in place
through the short term. Despite low clouds over eastern areas and
isolated light showers, temperatures are warm. We`ll reach the 70s
nearly everywhere, potentially hitting 80 in a few spots out west.
A sfc trough/Pacific cold front will enter our area from the NW and
stall over the Hill Country/Rio Grande Plains overnight. Although
isolated showers can`t be ruled out through midnight, better rain
chances will gradually ramp up out west along this boundary before
daybreak. This batch of showers and storms will gradually work it`s
way eastward through the daytime, but there remains high uncertainty
in it`s timing and evolution. The 12Z NAM throws a bit of a wrench
into the southward extent of the heaviest rains through the AM as
well. How quickly this round is able to move east will determine the
timing of a second round of showers and storms, which could develop
over our western areas in the afternoon. A more certain 2nd (3rd?)
round will develop over the Edwards Plateau tomorrow night,
impacting mainly the Hill Country before daybreak Sunday.
There will be some low (mainly <500 J/kg) CAPE in place overnight
tonight through the morning hours Saturday, but this will increase
through the afternoon, to >1000 J/kg near the Rio Grande. Extremely
strong bulk shear of 70-80 kts will be in place, and this will
likely limit strong storm potential until instability is able to
build enough to sustain updrafts. That said, there is a Marginal
Risk for severe storms for tomorrow afternoon through the overnight
for all rounds of convection, which could produce isolated instances
of all hazard types.
In addition, a Marginal Risk of Excessive Rainfall will be in place
tomorrow through tomorrow night for eastern areas. Rainfall amounts
of less than 0.25" are forecast near the Rio Grande and south of San
Antonio, but 0.25-1" amounts are likely elsewhere, with isolated
higher totals approaching 2-2.5" not out of the question. These
higher amounts are most likely over the Hill Country, northern
Austin Metro, and Coastal Plains. This could lead to some ponding on
roadways or minor culvert flooding should it occur over urbanized or
saturated areas. This rain during the day will also limit daytime
highs to the mid and upper 60s over these areas Saturday, while mid
to upper 70s are likely along the Rio Grande and south of San
Antonio.
&&
.LONG TERM...
(Sunday through Friday)
Issued at 149 PM CST Fri Feb 9 2024
Rain chances appear to remain fairly high on Sunday morning from the
Hill Country eastward into the I-35 corridor and coastal plains as an
upper low over west Texas slowly pushes eastward into north
Texas/southern Oklahoma. A Pacific cold front and upper level jet
will aid in precipitation chances during the morning hours. As the
front moves from west to east across the region, drier air in the
low-levels should bring a quick end to precipitation chances for all
areas Sunday afternoon. Given the amount of lift still expected over
the region, would not be too surprised to see an elevated shower or
two develop behind the front Sunday afternoon or evening. However,
will opt to keep the forecast dry at this time and continue to
monitor. Gusty west to northwest winds will spread in behind the
Pacific front Sunday. Winds out west across the Rio Grande plains may
briefly approach the lower end of our Wind Advisory threshold
(sustained 26 MPH). For now, confidence in wind speeds meeting
criteria is not high enough, so we will keep wind speeds just below
Advisory levels for now. We could also see some elevated fire weather
conditions develop over the Rio Grande plains Sunday afternoon given
dry and gusty winds along with little expected precipitation over
this region.
Winds will not drop off Sunday night into Monday as a reinforcing
shot of high pressure moves in from the northwest. Northwest winds
will remain breezy through Monday afternoon, then decrease around
sunset. High temperatures on Monday will range from the mid 50s in
the Hill Country to mid 60s along the Rio Grande. As winds decrease
Monday night into Tuesday morning, clear skies and dry air will
provide good radiational cooling conditions yielding overnight lows
in the 30s to near 40 degrees. Low-lying areas over the Hill Country
and nearby I-35 corridor near Austin may see near freezing
temperatures. Temperatures begin to rebound on Tuesday with sunny
skies and fairly light winds for most areas. The warming trend
continues into Wednesday as cloud cover begins to increase from south
to north. It is worth noting the 12Z operational ECMWF model no
longer shows a cold front moving into the region on Wednesday. We
will continue to monitor model trends and adjust the forecast as
needed. It will be cloudy and mild on Thursday with the next upper
level weather system expected to take shape over the Baja peninsula
or nearby eastern Pacific waters. We`ve seen quite a bit of
variability in the models with regards to the forecast late next
week. The latest operational runs of the GFS, ECMWF and Canadian are
showing an uptick in precipitation chances beginning Thursday night
into early Friday morning over the Rio Grande plains. Rain chances
should spread northward fairly quickly as the day progresses on
Friday. Again, with lots of recent model variability, the forecast
remains uncertain as we head into late next week.
&&
.AVIATION...
(00Z TAFS)
Issued at 532 PM CST Fri Feb 9 2024
At the I-35 sites, VFR flying conditions this evening deteriorate
overnight to MVFR, then IFR as SHRA develop. Poor flying conditions
continue on Saturday with IFR prevailing with LIFR or MVFR, at
times. S-SE winds at 5 KTs or less turn NE-E at 5 to 10 KTs on
Saturday.
At KDRT, VFR flying conditions prevail this evening through Saturday.
However, a brief period of MVFR is possible with SHRA overnight into
morning. NW winds around 10 KTs decrease this evening into overnight,
then become SE 5 to 10 KTs on Saturday.
&&
.PRELIMINARY POINT TEMPS/POPS...
Austin Camp Mabry 59 68 55 68 / 30 80 60 50
Austin Bergstrom Intl Airport 60 68 56 69 / 30 80 60 50
New Braunfels Muni Airport 60 70 56 72 / 30 70 50 40
Burnet Muni Airport 56 65 52 64 / 40 80 80 40
Del Rio Intl Airport 58 78 53 70 / 30 30 30 0
Georgetown Muni Airport 58 65 54 66 / 40 80 70 60
Hondo Muni Airport 59 71 54 69 / 40 60 50 10
San Marcos Muni Airport 60 69 55 70 / 30 70 60 40
La Grange - Fayette Regional 62 68 59 70 / 20 80 40 60
San Antonio Intl Airport 60 70 56 69 / 30 70 50 20
Stinson Muni Airport 62 71 58 71 / 30 60 50 20
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
Short-Term...KCW
Long-Term...Platt
Aviation...04
Area Forecast Discussion
National Weather Service Hastings NE
516 PM CST Fri Feb 9 2024
.KEY MESSAGES...
- Broadly speaking, the majority of the forecast is dry with
near normal to above normal temperatures (40s and 50s).
- Precip chances (10-20%) for both today and Saturday
afternoon/night have trended down, with little to no
accumulation expected.
- A chance for light snow (10-30%) possible next Friday as a
cold front tracks south across the local area.
&&
.DISCUSSION...
Issued at 200 PM CST Fri Feb 9 2024
A quiet weather day thus far with mostly sunny skies across the
majority of the area, light northerly breezes and temperatures
in the mid to upper 40s. Some mid level cloud associated with a
dissipating shortwave is streaming across north central Kansas,
but so far the better returns (although likely just sprinkles)
remain to our southwest. As this aforementioned wave tracks east
through the remainder of today, could see some very light
showers or sprinkles develop mainly across north central Kansas,
but given the dry air near the surface, most locations will
remain dry. As a result trimmed pops a bit for the remainder of
the afternoon and evening, leaving only the potential for
sprinkles primarily south of I-80 in the forecast, which should
be plenty generous.
For Saturday, expect an upper level shortwave diving south along
the western edge of the longwave trough to help strengthen the
low across the southwest, with this low eventually transitioning
east and well south of the local area on Sunday. While the
combination of lift and moisture will be sufficient for snowfall
across the high plains and western Nebraska ahead of this low on
Saturday, models have backed off on much precipitation locally,
likely due to the lack of low level moisture across the local
area. By the time the atmospheric profile does begin to saturate
on Sunday morning, the main upper level low will be well south
of the local area and tracking eastward. As a result, trimmed
back pops to areas primarily southwest of the tri-cities
Saturday evening/night with little to no accumulation expected.
Thereafter...expect the upper level flow to become west
northwesterly and more progressive, steering a few weak/dry
disturbances across the local area - which are expected to
bring little more than some passing cloud cover to the region.
Towards the end of the week, and upper level disturbance
originating from the Pacific Northwest will reach the local area
potentially bringing a small chance for snow along with some
cooler air on Friday. Still a long ways off, but about half the
ensemble members of both the EC and GFS are hinting at a light
precip event (<.25"), which if realized, will be a nuisance
type light snow event over the Friday through Saturday time
frame.
&&
.AVIATION /00Z TAFS THROUGH 00Z SUNDAY/...
Issued at 512 PM CST Fri Feb 9 2024
At first glance, the NBM and HREF look favorable for VFR
conditions through the TAF period , but more recent runs of
HRRR and RAP have been insistent on MVFR stratus moving in from
the north Saturday morning, potentially lingering into the
afternoon. As such, went ahead and added some BKN025 into both
GRI/EAR.
Winds remain out of the north, gradually turning more
northeasterly through the day on Saturday.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...None.
KS...None.
&&
$$
DISCUSSION...Rossi
AVIATION...Mangels
Area Forecast Discussion
National Weather Service Goodland KS
434 PM MST Fri Feb 9 2024
.KEY MESSAGES...
- Rain/Snow showers end early this evening.
- ~50% chance of freezing fog developing Saturday morning.
- Greater coverage of accumulating snow starting late Saturday
morning through Sunday morning.
&&
.SHORT TERM /THROUGH SUNDAY NIGHT/...
Issued at 148 PM MST Fri Feb 9 2024
DPVA located mainly south of I-70 has lead to the development
of rain and snow showers. Localized bands of moderate
precipitation is seen mainly across Cheyenne and Greeley
counties whom are in closer proximity to a surface low and a jet
streak just outside of the CWA which is perhaps leading to
these "heavier" areas of precipitation. This system will be a
fairly quick moving system as all precipitation is forecast to
be out of the CWA by 03Z. As for snowfall amounts little to no
snowfall accumulation is currently forecasted as road/ground
temperatures are well above freezing. If any snowfall
accumulation were to occur it would be across southern portions
of Greeley and Wichita counties near sunset as temperatures
start to cool and precipitation briefly becomes all snow before
ending.
Tonight, winds will become more ESE with some weak moisture
advection occurring. Some freezing fog is possible mainly along and
west of Highway 25 and along and south of I-70 where winds will be
the lightest. HREF probabilities are suggesting at a 30% chance in
visibilities becoming 1/2 mile or less across portions of Sherman,
Wallace, Greeley, Wichita, Kit Carson and Cheyenne (CO) so did
adjust the "Area" wording to portions of those areas. Western
portions of Kit Carson and Cheyenne counties may only see
patchy fog if any as incoming precipitation may play a role in
fog/formation coverage.
Onto Saturday, timing of the system has slowed a bit as it may not
be until after 11AM MT before snowfall starts affecting western
portions of Kit Carson, Yuma, Cheyenne counties and may not make it
into NW Kansas until after sunset. Snowfall amounts haven`t really
changed much from the previous shift as 1-3 inches looks most likely
especially along and west of Highway 27. It is interesting to
note that both the NAM and RAP suggest some convective snowfall
potential impacting locations along and west of Highway 59 in
Cheyenne and Kit Carson counties. RAP has been the most
aggressive with this with SBCAPE of 25-50 J/kg with unstable
lapse rates of 8-8.5C. If this were to come to fruition then
snowfall amounts of 3-6 inches would be possible along with
periods of reduced visibility due to periods of heavy snow. The
time frame for this scenario is currently 1p-5p MT. A concern
that I do have with snowfall amounts however is the ground
temperatures. The current soil temperature at the NWS office is
near 40 degrees and CDOT sites in Seibert and Firstview in Kit
Carson and Cheyenne counties respectively are 35-37 degrees
along with road temperatures above 40 degrees. Due to the warm
ground temperatures the biggest caveat to this snowfall forecast
is how long will it take for the ground to be able to start
accumulating. Due to this concern will hold off on any winter
weather highlights at this time; but will pass along to the next
shift to keep an eye on any potential ground temperature
changes that may occur. Winds continue to not look like to be a
major impact, they have come up somewhat to 10-15 mph sustained
gusting to 20 mph; but due to the expected wetter nature of the
snow any blowing snow potential would be localized.
Light to moderate snowfall looks to continue throughout the night
and come to an end just after sunrise Sunday morning. Overall
forcing from the system moves out of the area Sunday. However some
mid to upper level moisture looks to remain at least through the
morning keeping cloud cover prevalent across the area. This
currently looks to limit how much we are able to warm up as highs
in the upper 30s across the west to the mid 40s across the east are
currently forecasted, which is still climatologically normal
for early to mid February standards.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
Issued at 123 PM MST Fri Feb 9 2024
As we move into next week, the upper closed low bringing winter
weather to the Rockies and portions of the Southern Plains is
expected to move over Eastern Kansas and Eastern Oklahoma towards
Southeast CONUS. As the trough moves east, a weak ridge is expected
to slide southeast over the Rockies to the Central High Plains. On
Tuesday, a weak shortwave is expected to move over the area. The
only impacts from the disturbance at this time remains increased
cloud cover as it moves through. Late Tuesday through Thursday the
area is expected to be under weak ridging to nearly zonal flow with
very weak disturbances moving across the Rockies bringing in some
cloud cover. The next potential with low confidence(less than 30%)
may move through the region on Friday. Long range guidance has some
disagreements over whether or not a trough will develop over the
Western CONUS. Otherwise, dry conditions are anticipated over the
Tri-State area through the end of the period.
Temperatures each day are expected to be similar day to day during
the period with highs in the 40s to 50s. Overnight lows will be
mainly in the 20s each night with locales at higher elevations
possibly falling into the upper teens Monday and Friday.
&&
.AVIATION /00Z TAFS THROUGH 00Z SUNDAY/...
Issued at 426 PM MST Fri Feb 9 2024
For KGLD... VFR conditions are forecasted for the first half of
the period with IFR conditions more likely around or after 12Z.
There is the chance for freezing fog and snow tomorrow with the
fog more likely early in the morning and snow more likely in the
late morning and afternoon hours. The chance for either is
around 40-60%. The main driver behind the IFR conditions though
will be the drop in ceilings, even if the fog or snow doesn`t
quite move over the terminal. The influx of moisture will help
ceilings lower and stay low through the afternoon hours.
For KMCK... VFR conditions are forecasted for most of the
period. There could be chances for fog or snow starting around
12Z, but the chance for either is closer to 20% which isn`t
enough to include in the TAFs at this time. MVFR conditions are
possible during the morning hours as ceilings could lower
depending on how much moisture moves into the area. Otherwise,
any lowering of the ceilings is forecasted to return to VFR
later in the afternoon.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...None.
CO...None.
NE...None.
&&
$$
SHORT TERM...Trigg
LONG TERM...KMK
AVIATION...KAK
AREA FORECAST DISCUSSION
National Weather Service Wilmington OH
937 PM EST Fri Feb 9 2024
.SYNOPSIS...
A weak cold front will move east and through the Ohio Valley
early Saturday, bringing a chance of rain to the region.
Building high pressure in the Great Plains will then set up a
north flow later in the day. Overnight, this cooler air will
undercut northward spreading moisture originating from a
surface low in the Tennessee Valley tracking northeast along
the remnants of the cold front. Rain will become increasingly
likely Saturday night the further south from the Ohio River you
go.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
The ILN CWA remains in the warm sector in advance of an
approaching cold front, which is currently located from south of
Chicago through southern lower Michigan. A few very light
showers have developed across the area this evening, but most of
the area remains dry -- and it appears dry conditions will be
likely through around 09Z.
A fast-moving shortwave is expected to progress through the area
after 09Z, underneath a very strong 300mb jet (over 130kts) and
also associated with an 80kt 500mb jet streak. A band of showers
will develop ahead of these features -- likely remaining a bit
ahead of the surface cold front, and forced more from these
features aloft. Cooling temperatures at 700mb will lead to
steepening lapse rates, and HRRR/RAP runs have been consistent
in showing some elevated instability in the 09Z-12Z time frame
across the ILN forecast area. Thunder will be added to the
forecast for roughly the southern half of the forecast area. If
the mid-level lapse rates are as steep as the RAP is indicating
they will be -- and the 00Z KILN sounding would suggest that is
likely the case -- then it looks quite possible that some of
the convective cells could produce small (sub-severe) hail.
Have adjusted temperatures downward slightly through the
overnight period based on current trends.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SUNDAY/...
The rain over the CWA early Saturday will be most prevalent
along and south of the Ohio River given the intrusion of more
moisture at the apex of a low level wind maxima. This rain will
have ended near daybreak along and northwest of I-71, and by
later morning for the remaining CWA with drier air in the post-
frontal atmosphere. Highs will still be mild and range from the
lower 50s northwest to the lower 60s southeast.
The colder air will not enter until overnight once high pressure
well to the northwest builds a ridge axis to the southeast and
winds become northerly in the Ohio Valley. This will allow lows
to drop to near 30 in the north and near 40 in the south. A low
pressure system in the Tennessee Valley will have moisture
overtop the cold air expected in the CWA and could wring out
some rain by daybreak Sunday in the southern third of the CWA,
more likely over KY and far southern OH.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
Rain associated with a weak low pressure system skirting south of us
toward the Appalachians will be coming to an end Sunday morning
along and southeast of I-71. The daytime highs will feel noticeably
cooler compared to Saturday, only reaching the low 40s in the north,
low 50s in the south. With that being said, these temperatures will
still be slightly above normals. The remainder of Sunday daytime
hours should remain dry, however, this reprieve from precip is short-
lived, as another system looms to our west.
A longwave 500H trough that had been moving through western CONUS
aids in the deepening and organization of an area of low pressure
near Texas/ Mexico. As this system deepens under an area of
divergence aloft, it moves northeast through the Tennessee Valley,
bringing ample moisture from the Gulf along with it. Looking at
ensemble guidance, most members between the ECMWF, GFS, and Canadian
suggest precipitation onset somewhere between Monday afternoon
through 00Z Tuesday. Since this system will move past us to our
south, the northern shield of precipitation will likely start
briefly as rain before transitioning to snowfall as cold air is
wrapped down into the region.
Still a bit early to determine where that transition zone will be
(along with what time), but ensembles suggest some accumulation
somewhere along and north of the Ohio River. However, given how far
out we are, any wiggles in storm track will obviously shift any
snowfall.
After this system progresses eastward out of our region, weak
convergent flow aloft and surface high pressure take over, drying us
out for mid week. The CPC 6-10 day and 8-14 day outlooks indicate
that the area will likely shift back to below normal temperatures.
Looking near the end of the extended, guidance hints at additional
shortwaves poised to move through the larger flow, bringing
additional chances for precipitation.
&&
.AVIATION /03Z SATURDAY THROUGH WEDNESDAY/...
VFR conditions will continue for the start of the TAF period. In
the 01Z-05Z time frame, some showers are expected to move
through the area. The chances for impacts at the TAF sites
appear low, so these will not be included. If necessary, a brief
period of -SHRA may be added in later.
MVFR ceilings (likely below 2kft) will move into the area later
in the overnight hours. Rain will move into the area after 09Z,
with the greatest chance at the Cincinnati airports -- though at
least some light rain will probably occur at all the TAF sites.
There is a low probability of some heavier showers, or even a
thunderstorm, at Cincinnati in the 10Z-12Z time frame. Ceilings
should break to VFR at some point in the morning to early
afternoon.
Winds will remain out of the SSW at around 10 knots through the
overnight hours. On Friday morning, winds will shift to the WNW,
again at around 10 knots.
OUTLOOK...MVFR to IFR conditions are possible Monday into
Tuesday.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...None.
KY...None.
IN...None.
&&
$$
SYNOPSIS...Franks
NEAR TERM...Hatzos
SHORT TERM...Franks
LONG TERM...CA
AVIATION...Hatzos
Area Forecast Discussion
National Weather Service Indianapolis IN
902 PM EST Fri Feb 9 2024
.Key Messages...
- Rain chances overnight with low chances of thunder.
- Partly cloudy and cooler on Saturday and Sunday.
- Rain and a mix of snow possible Monday into Monday evening; any
impacts look minimal.
&&
.Forecast Update...
Issued at 901 PM EST Fri Feb 9 2024
Weakening short wave will move quickly northeast in fast southwest
flow aloft to northern Illinois by Saturday daybreak as an
associated 90+ knot jet streak moves across northern Indiana
overnight. Meanwhile, a 40+ knot low level jet will move from the
Ozarks to western Kentucky, pumping in moisture to go with warm
advection and alas fuel for widespread convection ahead of a cold
front, approaching from northwest Indiana. In addition, the jet
streak will induce a wave along the front. Finally, the increased
dew points and steepening mid level lapse rates will come into play
and the result will be widespread convection, especially south and
east of of I-69, closer to the low level jet. CAMs and upstream
radar trends support widespread convection moving into southwestern
sections around 06z and departing our eastern counties shortly after
daybreak. 70% PoPs look good bordering PAH, LMK and ILN with lower
chances over the upper Wabash Valley.
Overnight lows in the lower 40s look good in the wake in the front
or near and west of I-69. Ahead of the front, temperatures should
get no lower than the lower 50s.
&&
.Short Term...(This evening through Saturday)
Issued at 140 PM EST Fri Feb 9 2024
Surface analysis early this afternoon shows deep low pressure north
of Lake Superior. High pressure was in place over the Carolinas.
These two systems continued to produce a moderate south to southwest
flow across Central Indiana of mild air. GOES16 shows some
scattered CU quickly dissipating across Central Indiana.
More importantly, Water Vapor shows a plume of tropical moisture
streaming across northern Mexico, into the southern plains and
across the deep south which is a classic El Nino type
teleconnections. The plume was just barely brushing southern Indiana.
Temperatures across Central Indiana remained very warm for February,
soaring near records in the mid 60s. Radar mosaics shows some
showers beneath the plume across the deep south.
Tonight -
Dry weather will be expected this evening. Rain chances will arrive
overnight.
Look for quiet weather this evening as the tropical plume to the
south continues to spread clouds across the Ohio Valley. Overnight a
quick moving area of weak low pressure found over Kansas along with
an upper level short wave within the flow is expected to toward and
across Central Indiana. As these features approach, model suggest
they will tap the tropical plume to the south, as it ripples
northward, providing some moisture. HRRR and DESI ensemble members
suggest the development of precipitation tonight as these features
quickly pass. Forecast soundings fail to show deep saturation
overnight as pwats only briefly reach about 0.70 inches. Ultimately
there is enough here to include at least chc to likely pops,
particularly across the southern parts of the forecast area, closer
to the more favorable moisture. Forecast soundings do briefly show
lapse rates favorable for convection, mainly aloft. Thus a rumble of
thunder cannot be ruled out should showers develop. Overnight, cold
air advection begins rather late in the wake of the wave. Thus lows
in the middle to upper 40s will be expected.
Saturday -
Models suggest that the upper moisture plume will remain over the
Ohio Valley on Saturday, providing clouds. This flow aloft is
suggested to evolve toward a ridge like feature. Meanwhile within
the mid levels, ridging is shown to be present along with
subsidence. Forecast soundings through the day show dry lower and
mid levels with subsidence. Thus partly cloudy will be the way to go
with some higher clouds still possible from the flow aloft,
particularly across the south. Given the cold air advection and
northwest winds expected tomorrow in the wake of the front, highs in
the upper 40s to lower 50s should be expected.
&&
.Long Term...(Saturday night through Friday)
Issued at 140 PM EST Fri Feb 9 2024
Saturday Night through Sunday...
The beginning of the long term will be fairly uneventful as central
Indiana fall into a baroclinic transition zone between low pressure
to the south and high pressure to the N/NW. Winds may be elevated
at times Saturday night, but a progression towards easterly winds
with an approaching surface low will weaken westerlies aloft and
lead to light winds on Sunday.
Temperatures will be cooler than previous days, but will remain
above normal and the continental Polar airmass originates from
adiabatically warmed air over the Plains. Current expectation is for
Highs in the upper 40s on Sunday.
Sunday night and Monday...
This middle stretch will be the most active in the long term;
associated with an approaching low from the SW. Deeper troughing
will progress into the plains with cooler air beneath. This in
combination with the tight baroclinic zone will foster the deepening
of a surface low over the Ohio Valley Sunday night through Monday.
Moisture attached with this low will be plenty sufficient for modest
precipitation rates; PWATs are expected to be well above seasonal
normals. The biggest uncertainty will be associated with P-Type and
timing.
Antecedent temperatures on Monday will be on the mild side with
temperatures prior to precip onset in the low 40s. Evaporative
cooling will push temperatures back into 30s, but there is a lot of
uncertainty as to how low dew points will be on the northern portion
of this low. Ensemble spread is between 32 and 38, of which would
have significant impacts on P-type. WAA looks minimal in the low
levels at least, limiting concerns for sleet/ice. One feature of
note is the consistent near to just blow freezing isothermal layer
near 900-850mb. This could allow for snow even within slightly above
freezing surface temperatures.
Regardless of p-type, impacts should remain low as multiple days
well above seasonal norms have elevated ground temperatures
considerably. Without consistent and prolonged snowfall/rates,
accumulation will be difficult to achieve. Even if QPF and snowfall
reach the 75th percentile in ensemble guidance, snow depth change
would remain below 2". With this said, central IN is still 72 hours
away from event onset, and changes to the forecast are possible.
When dealing with snow potential, its always advised to remain aware
of forecast updates, even if currently the forecast is for minor to
no impacts.
Tuesday onward...
Following the low pressure passage, winds will remain westerly with
minimal CAA. This should keep temperatures fairly mild with highs in
the 40s to low 50s. There is some increasing confidence in a
shortwave passage towards the end of next week, of which could lead
to rain chances and slightly warmer than expected temperatures
depending on location and timing.
&&
.Aviation...(00Z TAF Issuance)
Issued at 612 PM EST Fri Feb 9 2024
Impacts:
- MVFR conditions at times 05z-13z
- Shower chances 06z-11z with best chance at KBMG
- A lightning strike or two can`t be ruled out
Discussion:
A upper wave will move northeast across the western Great Lakes
overnight. In addition, a cold front will drop southeast to near the
I-70 corridor by morning. Increase in moisture and instability along
with the above features and a upper speed max and steep mid level
lapse rates will allow for shower chances overnight with the best
chances at KHUF and KBMG.
MVFR flying conditions with mainly stratocu will be possible
overnight as well. VFR conditions will return Saturday near or after
daybreak.
Southwest winds 8 to 12 knots will switch to west and northwest
after 07z from northwest to southeast as the cold front moves past.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
Update...MK
Short Term...Puma
Long Term...Updike
Aviation...MK
Area Forecast Discussion
National Weather Service Louisville KY
834 PM EST Fri Feb 9 2024
.KEY MESSAGES...
* Showers becoming widespread after midnight.
* A period of thunderstorms is possible toward dawn Saturday
morning. Some storms may be strong/severe with damaging wind
gusts being the main threat. Some marginally severe hail in some
of the stronger cores is possible.
* Two chances for precipitation are expected Saturday night into
Sunday morning and Monday into Monday night. Precipitation may
change to a brief period of snow Monday night, though forecast
confidence is low.
&&
.UPDATE...
Issued at 832 PM EST Fri Feb 9 2024
Quiet across the region at this hour, but the bigger story will be
convection ahead of a cold front near dawn tomorrow. Models still
continue to bring in a wave of convection to our western zones by
about ~8z-9z, and quickly push it eastward through the morning hours
Saturday. High-Res CAMs have some variability with the strength and
coverage of convection during the early morning hours, with the HRRR
unsurprisingly being the strongest of the bunch.
As mentioned in the afternoon discussion, the environment within the
warm sector will have strong low and deep layer shear. The biggest
limiting/conditional factor for severe weather will be marginal mid
level lapse rates and the strength of the low level/nocturnal
inversion. While severe chances are low, it does appear there could
be a narrow window mainly west of I-65 where the inversion could
potentially be very weak so that isolated surface based strong or
severe storms are possible (with a tornado/wind threat). Outside of
that, a low-end hail threat is also possible in more isolated
stronger storms. East of I-65, the low level moisture/Td`s and mid-
level lapse rates are lower/weaker, respectively, so severe
potential looks near nil out there. The overall thermodynamics are
fairly marginal, but with strong shear in place, you can never let
your guard down in these types of setups.
Overall forecast remains on track. Have tweaked some of the PoPs to
account for timing based on the latest guidance; otherwise,
everything else remains in good shape.
&&
.SHORT TERM /THROUGH SATURDAY/...
Issued at 320 PM EST Fri Feb 9 2024
Afternoon satellite imagery shows plenty of high clouds streaming
across the region. Underneath these high clouds, there is a bit of
low cloud cover covering much of southern Kentucky. A few showers
were located across our southern row of KY counties and into the
Lake Cumberland region. Temperatures under the thicker low clouds
have not responded that much and remain in the low-mid 50s. Further
north where only high cloud cover was observed, temperatures were a
little warmer with readings in the lower to middle 60s. For the
remainder of the afternoon, the best chances of any rain showers
looks to be in areas south of the Cumberland Parkway. Highs on the
day should occur in the next 30-60 min with temps falling back into
the upper 50s to around 60 by sunset.
For tonight, an area of low pressure over Missouri will lift
northeast and head toward the Great Lakes while weakening. The
trailing cold front will slide eastward toward the lower Ohio Valley
in the pre-dawn hours. Ahead of the front, combination of
isentropic lift and warm advection will move in after sunset. Some
spotty showers may develop as early as mid-late evening in areas
west of I-65, but for the most part, the evening period looks pretty
dry. The main thrust of lift and convective development is likely
to hold off until after midnight as the 45-50kt low-level jet axis
pushes into the region from the TN valley into eastern KY while a
mid-level jetlet pushes into IN/OH from IL.
Initial convection overnight may remain elevated in nature as model
soundings show a stable layer near the surface with steeper lapse
rates aloft yielding elevated instability. Most model progs
continue to show deep layer shear, but instability remains
uncertain. The HRRR is the most aggressive with instability while
the 3K NAM is a bit more restrained. There is a signal in the HRRR
data from the last several runs that some sort of linear convective
cluster may develop to our west around 10/06-07Z ahead of the cold
front and then spread eastward. Despite the weak instability, there
is a low end threat of at least isolated-scattered damaging wind
gusts with this line, if it develops and holds together. The wind
damage threat will also be augmented by how well the low-level
stability holds up. Some soundings do show this stable layer
weakening in the 10/09-11Z time frame. A spinup tornado within the
convective line is also possible, but overall tornado threat looks
to be the lowest of the overall convective threats. Additionally,
given the deep layer shear, steep lapse rates aloft, and low wet-
bulb zero heights, some marginally severe hail could occur, but I
think that would only be a threat in more isolated storms that can
develop out in the open warm sector. Given the overall setup and
uncertainties, the marginal risk from SPC appears reasonable for
areas mainly along and west of I-65. As for temperatures, I kept
things on the warmer side of guidance given the warm advection
scheme and the models usually handling these pretty badly. So plan
on lows in the mid-upper 50s.
For Saturday, surface cold front looks to cross the I-65 corridor
after sunrise and then continuing to push south and east through the
day. Thunderstorm activity will quickly diminish behind this front
from NW to SE with most areas north of the Cumberland Parkway going
dry by lunchtime. Will keep a chance of showers down along the
KY/TN border region through the afternoon hours as the frontal
boundary may hang up down there. Highs on Saturday will range from
the upper 50s over southern Indiana to the mid-upper 60s across much
of Kentucky.
&&
.LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/...
Issued at 320 PM EST Fri Feb 9 2024
Synopsis: Large-scale deep SW flow will continue for the second half
of the weekend through Monday evening, when the mid- and upper-level
trough axis is expected to pass through the Ohio Valley. Within this
SW flow regime, an active pattern will unfold as individual waves of
low pressure and precipitation will ride up and along this broad
baroclinic zone stretching from southern TX into the mid-Atlantic
states. Most of the forecast uncertainty during the late weekend
into early next week period centers around the exact positioning of
this zone, as a shift to the south (north) would result in less
(more) precipitation across southern Indiana and central Kentucky.
Once the upper trough axis clears to the east of the region Tuesday
morning, zonal or somewhat NW mid- and upper-level flow is expected
for the middle of next week, with sfc high pressure building across
the deep south, eventually extending into the TN and lower OH
valleys. By the end of next week, there is a general trend toward
amplification of the synoptic scale pattern, with a deepening of the
trough over the east coast of North America brought about by
multiple descending shortwaves which may clip the Ohio Valley. The
extent and speed with which this pattern amplification occurs is the
source of considerable disagreement in the models, and forecast
confidence drops off after next Wednesday.
Saturday Night and Sunday...
Low pressure system number 1 will slide across the Tennessee Valley
Saturday evening into Sunday morning, with an area of rain extending
northwest of the low into central Kentucky. There is increasing
agreement that the cutoff in precipitation will be fairly close to
the Ohio River, with heavier rain totals expected along and
southeast of the western KY/Bluegrass Parkways. Rain totals with
this wave are expected to range from a trace to 0.10" along the Ohio
River to 0.75-1" along the TN border and into the Lake Cumberland
region. There should be a brief break in precipitation chances
during the day on Sunday as the region sits between two waves of low
pressure, with a few breaks of sunshine possible, especially north
of the Ohio River.
Sunday Night through Monday Night...
Low pressure system number 2 will be associated with the main upper
trough passage Monday into Monday night as an initially cutoff low
opens up and ejects east-northeastward into the mid-Atlantic by
Tuesday morning. In the latest deterministic model guidance, there
is increasing confidence in a sfc low track across middle TN and
into southeastern KY on Monday, which should keep the bulk of any
strong/severe thunderstorm threat to our south (assuming perfect
prog). CIPS Severe Analogs and CSU Machine Learning probabilities
agree, keeping any severe threat confined to the deep south on
Monday. However, elevated instability should be sufficient for at
least a few rumbles of thunder, especially across south central KY.
By Monday evening, the sfc low will cross into eastern KY, with cold
advection wrapping around the northwest side of the low. As previous
discussions have mentioned, TROWAL axis/mid-level
frontogenesis/deformation features are consistently showing up in
medium range guidance, suggesting a possibility for increased
precipitation rates within a band on the back side of the system.
This would increase the probability of seeing a brief transition to
snow as precipitation ends Monday night, particularly across the KY
Bluegrass region. It is worth noting that both the ECMWF/GEFS
ensemble 50th percentile snow amounts now show accumulating snowfall
Monday night for portions of the CWA. Stepping back from the
statistical side of things, it still looks like it will take heavier
precipitation rates to see snow, as the near-sfc layer will be well
above freezing initially, requiring colder air aloft being dragged
down to the surface to avoid low-level melting. At this time,
considering warm antecedent sfc conditions, widespread impacts are
not expected, with any snow that falls likely melting fairly quickly
after precipitation ends.
Tuesday through the rest of next week...
Once the system clears the region Tuesday morning, there is medium-
high confidence in dry weather for the day on Tuesday and Wednesday
as high pressure dominates over the southeastern CONUS. The upper
level pattern which follows the Monday disturbance will initially be
fairly zonal, and any cold advection which overspreads the region
Monday night will be short lived with seasonable or slightly above
normal temperatures expected for the middle of next week.
By the end of next week, ensemble mean 500 mb flow pattern shows
digging troughing across the eastern CONUS, amplifying NW flow over
the Ohio and TN Valleys. Current model depictions show shortwaves
diving out of central Canada, bringing transient chances for
precipitation next Thursday and Friday. However, forecast confidence
is fairly low at this time as there is considerable spread in
specifics among the different medium-long range ensemble families at
this time.
&&
.AVIATION /00Z TAFS THROUGH 06Z SUNDAY/...
Issued at 601 PM EST Fri Feb 9 2024
MVFR cigs have nearly overspread the region at this hour and will
continue to expand in coverage overnight ahead of a cold front. Some
localized IFR cigs remain possible. Showers and even a few
thunderstorms will push in from the west after midnight, likely
arriving near dawn for many sites. Cigs/Vis in the heavier shower or
storms could be briefly reduced, and brief but strong wind gusts are
possible. The front should slide through the region by mid to late
morning, turning winds from the southwest to the northwest. We`ll
see a bit of a lull in precip at most TAF sites with the passage of
the front, but additional light precip looks to move in right at the
end of the forecast period for some central KY locations.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...None.
IN...None.
&&
$$
UPDATE...
SHORT TERM...MJ
LONG TERM...CSG
AVIATION...DM
Area Forecast Discussion
National Weather Service Norman OK
520 PM CST Fri Feb 9 2024
...New AVIATION...
.SHORT TERM...
(This evening through Saturday)
Issued at 425 PM CST Fri Feb 9 2024
With the passage of a cold front tonight, winds shift to the north
and overnight lows will range from near freezing (northwest OK) to
upper 40`s (southeast OK). Rain chances return to southern portion
of the area tomorrow morning and spread northward throughout the
day. However, best rain chances are confined to areas south of
I-40. Daytime highs will be a bit cooler than recent days with
highs in the 50s.
&&
.LONG TERM...
(Saturday night through next Thursday)
Issued at 425 PM CST Fri Feb 9 2024
Overall, recent model trends are farther south with axis of higher
QPF and less with snow accumulations and snow depth. Timing of
change over to snow remains uncertain with the HRRR and RAP
showing the earliest beginning time for snow.
Despite the wide swing in modeled snowfall (and track of the upper
low), there is still the potential for appreciable snowfall along
the backside of the mid/upper- level low as a TROWAL develops.
Currently, this appears to be over west-central, southwest Oklahoma,
with a sharp gradient in snowfall extending into parts of western
north Texas.
Interestingly, the 12Z observed upper air sounding in Washington
(which is where the upper level storm system was this morning), shows
a larger H500 height fall than depicted in models for that time.
This would suggest guidance is under predicting the strength of
the upper wave, even now. It seems the RAP has picked up on this
as it depicts a somewhat deeper low as it reaches the four corners
region tomorrow with a swath of heavy snowfall within the
deformation zone just west of the OKC metro and across southwest
OK into parts of western north TX. Hence, we think we are still in
play for some significant snowfall rates. A Winter Storm Watch
has been issued for parts of west-central and western Oklahoma and
adjacent western north Texas.
&&
.AVIATION...
(00Z TAFS)
Issued at 519 PM CST Fri Feb 9 2024
VFR will apply through the forecast period. The main aviation
concern will be a wind shift that occurs after 00Z and through
the overnight periods, as they become westerly, northwesterly, and
then finally northeasterly. High clouds will continue to dominate
the sky.
&&
.PRELIMINARY POINT TEMPS/POPS...
Oklahoma City OK 39 55 37 40 / 0 20 50 90
Hobart OK 38 56 36 38 / 0 20 60 90
Wichita Falls TX 43 58 43 46 / 0 40 70 90
Gage OK 32 50 31 39 / 0 20 60 40
Ponca City OK 36 53 36 45 / 0 0 20 40
Durant OK 47 61 46 49 / 10 60 50 90
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...Winter Storm Watch from late Saturday night through Sunday
evening for OKZ009-010-014>017-021>023-033>038-044.
TX...Winter Storm Watch from late Saturday night through Sunday
evening for TXZ083-085-086.
&&
$$
SHORT TERM...01
LONG TERM....01
AVIATION...03
Area Forecast Discussion
National Weather Service Pueblo CO
431 PM MST Fri Feb 9 2024
.KEY MESSAGES...
- Another round of moderate to heavy snow expected for the
southeast mountains, I-25 corridor and southern plains
Saturday through early Sunday morning.
- Normal to slightly above normal temperatures along with dry
weather return for much of next week.
&&
.SHORT TERM /THROUGH SATURDAY NIGHT/...
Issued at 249 PM MST Fri Feb 9 2024
Compact upper low continues to weaken and pull eastward into KS
this afternoon as the next upper low takes shape across the
northern Rockies. Jet energy digging southward will carve out an
upper low across southern UT/northern AZ tonight which will
eject eastward across NM through Saturday night into Sunday
morning. A lull in precipitation will continue across the area
through much of tonight before snow ramps back up from west to
east early Saturday as upper lift increases ahead of the
approaching system. Upglide around the north side of the upper
low increases Saturday morning with heaviest precipitation
blossoming across most of southern CO Saturday afternoon and
evening as isentropic upglide intensifies and the atmospheric
column saturates. While trends have been towards a farther south
solution with the storm track, the northern extent of
deformation band precipitation still has strong signals for
producing some heavy snow across southern portions of the
forecast area. As H7 winds pull easterly, heaviest accumulations
will be focused across the eastern slopes of the Wets and
southern Sangre De Cristo mountains and southern I-25 corridor
where 50-80% of National Model Blends show greater than 6 inches
of snow through Sun AM. Northern El Paso county also shows up
to 50% of members having 6"+ of snow...a weaker signal but still
significant. Per collaboration with neighboring offices will
upgrade watches to warnings, adding the Wet mountains where
easterly upslope will amplify totals. Will hoist advisories for
the remainder of the southeast mountains and I- 25 and highway
50 corridor counties with the heaviest falling to the west of
I-25 and south of highway 50. While Baca county shows a weaker
signal for warning criteria (6"+) of snow, high res models are
trending heavier with QPF and model soundings suggest diabatic
cooling will likely drive snow levels down to the surface in the
afternoon and evening. Snowfall rates could be heavy enough to
cause slushy and snow covered roads, especially as the heavier
snow sets up in the evening. So will lean towards the higher
side of totals for southern areas.
Some areas to watch will be the southern San Luis Valley and
eastern San Juan mountains. Some of the high res models are
picking up on the possibility of heavier QPF totals across these
areas as the wrap around precipitation shield sets up. Should
this occur earlier than the consensus of models shows, then
advisories may need to be expanded westward to include these
areas.
Otherwise, have kept temperatures on the cooler side of
guidance for high temperatures on Saturday. Snow will continue
heaviest through the evening with a convergent band setting up
and sagging southward across El Paso county in both the HRRR and
NAMNest solutions. Once this progresses southward,
precipitation will decrease towards 06z before diminishing
towards 12-15z Sunday across southern areas. -KT
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
Issued at 249 PM MST Fri Feb 9 2024
The large upper level trough will continue to shift southeast
of the region on Sunday, while any remaining snow quickly
diminishes. Some light snow may persist early Sunday morning
across the far southeast mountains and far southeast plains,
however, any impactful snow should be done at that point.
Clearing in the morning time frame will return sunny skies to
most of southern Colorado by Sunday afternoon, as highs rebound
into the upper 30s and low 40s for most locations. Northwest
flow with some additional mid level energy will likely move
across the region at the start of next week. Dry setup will
limit precip development, but this will help to limit additional
warming. Will see some ridging aloft and some warming through
mid week, as normal temps begin to become more above normal.
During this time frame, dry weather will likely persist. By the
end of next week, confidence is not overly high with the
anticipated setup. Will keep an eye on this period though, as
there are hints of a much colder air mass trying to make its way
south towards the area. Once again, low confidence on this
possibility at this time.
&&
.AVIATION /00Z TAFS THROUGH 00Z SATURDAY/...
Issued at 432 PM MST Fri Feb 9 2024
An upper level storm system will bring widespread snowfall to
much of south central and southeast Colorado on Saturday.
Expecting MVFR to IFR conditions developing at COS and PUB
between 10Z-14Z with IFR and LIFR conditions developing by 18Z
and then persisting through the rest of the taf period. Winds
will be generally light east to southeast through the period.
Snow accumulations at the terminals of 2 to 4 inches will be
possible through the day Saturday.
Mainly VFR conditions expected at ALS, with the potential for
brief MVFR conditions with scattered snow showers developing
after 10Z.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory from 5 AM Saturday to 5 AM MST Sunday
for COZ072-073-078-081>086-093-097-098.
Winter Storm Warning from 5 AM Saturday to 8 AM MST Sunday for
COZ074-075-087-088-094-099.
Winter Storm Warning from 5 AM Saturday to 5 AM MST Sunday for
COZ079-080.
&&
$$
SHORT TERM...TORGERSON
LONG TERM...RODRIGUEZ
AVIATION...WANKOWSKI
Area Forecast Discussion
National Weather Service Topeka KS
538 PM CST Fri Feb 9 2024
.KEY MESSAGES...
- Very light precipitation possible through this evening
- Precipitation chances Sunday into early Monday continue to diminish
- Mild and benign conditions much of next week
&&
.DISCUSSION...
Issued at 204 PM CST Fri Feb 9 2024
Regional radar data today has shown some weak returns to the north
and west of the local area, with most activity in western Kansas.
This is in association with a small though rather potent upper wave
which will make its way east-northeast tonight though weaken as it
does so. The surface front from southwest Kansas into east-central
Kansas early this afternoon will provide baroclinicity ahead of this
wave with mid-level lapse rates around 8 C/km, but the lack of
moisture looks to be a limiting factor for measurable precipitation.
Have backed off any mention to trace amounts. Temperatures could
fall enough to support wintry types in northern areas around
midnight. The front surges on south tonight for a cooler Saturday,
particularly if the RAP verifies with a shallow low stratus deck
building in. It is about the only model doing this, but has been
handling the stratus in northeast Nebraska the best today, albeit a
bit overzealous in coverage.
Model trends continue to show a farther south track to the next wave
moving through the southern Plains Saturday night through early
Monday. With a reinforcing shot of mid-level dry air behind a
northern Plains upper wave, chances for precipitation have nearly
been removed from the local area. The upper flow steadily becomes
more zonal into the middle of next week spelling warming
temperatures. There are indications of a change in the pattern late
in the week that could bring cooler conditions and at least small
chances for precipitation.
&&
.AVIATION /00Z TAFS THROUGH 00Z SUNDAY/...
Issued at 537 PM CST Fri Feb 9 2024
VFR is forecast for the period. Can`t rule out a stray sprinkle
this evening, but limited moisture would keep any precip brief
if it occurs at all. It`s still worth monitoring MVFR stratus
potentially dropping southward from NE and IA overnight into
Saturday morning; however, the guidance that currently has the
best handle on this does not bring it far enough south so have
opted to keep it out of TAFs. Otherwise, expect northerly winds
to prevail under 10 kt.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
DISCUSSION...Poage
AVIATION...Picha