Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 10/05/23
Area Forecast Discussion
National Weather Service Dodge City KS
500 PM CDT Wed Oct 4 2023
...updated aviation...
.SHORT TERM...(This evening through Thursday night)
Issued at 200 PM CDT Wed Oct 4 2023
Latest water vapor satellite imagery and RAP upper air analysis at
midday depicts longwave troughing over the majority of the CONUS
between a pair of ridges over the east and west coasts. At the
surface, strong northerly winds behind last night`s cold front
have been slowly relaxing throughout the morning and early
afternoon, and this trend will continue as weak surface high
pressure builds into the central plains. As usual, a much cooler
airmass has accompanied these north winds, fostering afternoon
highs today in the low to mid 70s. Tonight, the typical diurnal
minimum in winds will combine with clear skies to support
temperatures dropping into the mid 40s to low 50s by sunrise
Thursday.
Little change is expected to sensible weather during the day
Thursday as the upper level longwave trough inches eastward while
a vorticity maximum rounds its base over the southern plains.
Surface pressure response to this shortwave feature will manifest
in an uptick in northerly winds during the late morning and
afternoon. However, any reinforcing shot of cool air associated
with this evolution will be offset by 850-mb temperatures warming
by 1-3 degrees C, resulting in a slightly warmer afternoon
Thursday with highs in the mid/upper 70s to near 80. Thursday
night, winds will once again weaken under mostly clear skies
allowing temperatures to drop into the mid 40s to low 50s for the
second consecutive morning.
.LONG TERM...(Friday through Wednesday)
Issued at 200 PM CDT Wed Oct 4 2023
Key Messages: Stronger surge in cold air expected early Friday,
knocking afternoon temperatures into the 60s. First freeze of the
season is possible Saturday morning, especially across the
northern zones. Warming trend begins Saturday afternoon through
the middle of next week.
Medium range ensembles are in good agreement suggesting a potent
vorticity maximum on the western periphery of the upper level
longwave trough will dig southeastward into the Midwest daytime
Friday. Behind this feature, a much cooler airmass will surge
southward through the northern and central plains via strong
northerly winds, resulting in afternoon highs in the 60s for most,
if not all, of southwest KS. Only areas along the KS/OK border
have a chance to approach 70. There is a hint some light rain
showers could materialize across the northern zones, however
ensemble meteograms have been trending downward with precipitation,
as now only a handful or two of the EPS members forecast any QPF.
As surface high pressure settles into our area Friday night into
Saturday morning, winds will weaken to light and variable with
clear skies. This will set the stage for the first potential
freeze of the season, primarily across the northern zones, as
temperatures plummet into the 30s. While ensemble probabilities of
reaching 32 degrees or lower are near zero, NBM lows are in the
32-34 degrees range along/north of US-50, which has prompted the
addition of frost in the weather grids.
Following the chilly Saturday morning, medium range ensembles
agree a warming trend will commence across southwest KS as the
upper level longwave trough finally departs, and building upper
level ridging over the western CONUS begins to take hold.
Afternoon highs will increase from the upper 60s/low 70s on
Saturday into the mid 80s by Tuesday/Wednesday. Furthermore,
synoptic-scale subsidence ahead of the ridge will likely inhibit
any widespread precipitation chances through the end of the
period.
&&
.AVIATION...(For the 00Z TAFS through 00Z Thursday evening)
Issued at 500 PM CDT Wed Oct 4 2023
VFR is expected through TAF pd. NE winds 5-15 kt becoming light and
variable as high pressure moves over tonight. A front will move across
the terminals during the morning tomorrow with NW to N winds increasing
15-20 kt through the day.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 48 77 47 64 / 0 0 0 10
GCK 46 74 45 63 / 0 0 10 10
EHA 46 76 46 67 / 0 0 0 0
LBL 46 76 47 66 / 0 0 0 10
HYS 48 74 46 61 / 0 0 10 10
P28 53 79 50 66 / 10 10 0 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Springer
LONG TERM...Springer
AVIATION...Sugden
AREA FORECAST DISCUSSION
National Weather Service Hastings NE
957 PM CDT Wed Oct 4 2023
.UPDATE...
Issued at 955 PM CDT Wed Oct 4 2023
Just sent a minor update to introduce some sprinkles to N/NE
portions of the forecast area late tonight. Model initializtions
and satellite data indicates a decently strong shortwave trough
over the Black Hills to North Dakota region that is forecast to
drop SE overnight. Latest trends of cooling clouds tops in NW Neb.
seems to jive with recent HRRR runs that have been showing incr
potential for very lgt QPF due to lift from aforementioned
shortwave and pocket of moisture in the 7-13K ft layer. Have
doubts we`ll get to full blown showers (and up to tenth of QPF)
that HRRR suggests...and quick glance of new 00Z HREF shows HRRR
to be on the aggressive side...but think its reasonable to believe
there will be pockets of virga and sprinkles for mainly N/NE zones
in the 06Z to 12Z time frame.
Also, trended temps and dew points a bit lower for Fri-Fri night
due to concerns for elevated fire weather Fri aftn, then
frost/freeze Fri night. Will pass along concerns to incoming mid
shift for potentially more signifcant grid adjustments and/or
headline decisions with the next main/full forecast package.
&&
.DISCUSSION...(This evening through Wednesday)
Issued at 322 PM CDT Wed Oct 4 2023
Key Messages:
* There is a slight chance of rain showers Thursday night across
most of the area.
* Low temperatures Friday night are expected to drop into the 20s
and 30s with widespread frost conditions likely. Freezing
temperatures are possible for portions of the area.
* Temperatures on Thursday will be similar to those today. A cold
front with gusty northerly winds is expected on Friday with
highs mostly in the 50s. Temperatures will warm through the
weekend.
Today through Thursday night...
A big upper trough extends from Canada south towards Arizona. North
to northwest winds are across south central and central Nebraska and
north central Kansas behind the cold front. High temperatures today
are expected to be in the mid 60s to mid 70s. Winds will become
southerly this evening then shift to the west later tonight. Low
temperatures tonight will mostly be in the 40s with mostly clear
skies. Northerly surface winds will move across the area on Thursday
as the upper trough moves slightly eastward. The northerly winds
will keep temperatures on Thursday fairly similar to those today.
Low temperatures Thursday night are expected to mostly be in the
40s. Rain showers are possible Thursday night across most of the
area.
Friday through Saturday night...
An upper low will move southeastward out of Canada within the main
upper trough on Friday. This will result in another cold front
pushing through Nebraska and Kansas on Friday as the upper trough
moves to the east. This front will result in high temperatures
mostly in the 50s on Friday with gusty north to northwest winds. The
surface high will move closer to the area Friday night with light
west to northwest winds and mostly clear skies. This will result in
temperatures plummeting into the 20s and 30s Friday night with
widespread frost conditions likely and possible freeze conditions
for portions of the area. The upper trough will continue to move
eastward on Saturday with a surface high present from Minnesota to
Texas. Winds on Saturday will generally be out of the southwest with
mostly sunny skies. High temperatures on Saturday are expected to
mostly be in the 60s. Temperatures Saturday night will warm up
slightly from the previous night with lows mostly in the 30s.
Sunday through Tuesday...
A warming trend is expected on Sunday as the upper trough moves
further east. High temperatures on Sunday are expected to mostly be
in the 70s. Even warmer temperatures are expected by Tuesday with
highs on Tuesday in the mid 70s to mid 80s.
&&
.AVIATION...(For the 00Z KGRI/KEAR TAFS through 00Z Friday)
Issued at 644 PM CDT Wed Oct 4 2023
VFR conditions likely through the period. Main concern will be
changing and increasing winds late tonight into Thursday AM with
the passage of a cold front. Expect a period of lgt and vrbl wind
through around midnight, before bec primarily SSW to WSW 5-10kt
thru around dawn. Winds will continue to veer to NW by mid-morning
and incr behind the front. Gusts around 25-30kt expected late
morning thru aftn before decr Thu eve. Patches of mid level clds
8-12K ft will pass thru late tonight into Thu AM. Confidence: High.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE...Thies
DISCUSSION...Schuldt
AVIATION...Thies
Area Forecast Discussion
National Weather Service Goodland KS
539 PM MDT Wed Oct 4 2023
.SHORT TERM...(This evening through Friday Evening)
Issued at 250 PM MDT Wed Oct 4 2023
At the beginning of the short term period, the latest RAP analysis
displays the CWA underneath the base of a positively tilted trough
which has its axis just to the west of the CWA allowing for a
southwesterly flow aloft. Current surface observations and satellite
imagery report dry conditions underneath some high clouds moving
east-northeastward across the region. Going through the remainder of
Wednesday, forecast guidance shows the trough axis passing over the
CWA causing the upper air flow to turn north-northwesterly
overnight. At the surface, dry conditions and relatively light winds
expect to continue through the evening while a surface high is
projects to move eastward along the KS/NE border. Overnight lows for
tonight look to be in the lower to middle 40s.
On Thursday, models show the CWA with a northwesterly flow through
the entire day as the CWA is underneath the rear portion of the
trough moving eastward with a trailing ridge moving over the western
CONUS. At the surface, a cold front is projected to move through the
region through during the day from the north bringing cooler air to
region along with a breezy northerly winds in the afternoon. Some
models also suggest at a slight chance for light showers for the
northeastern quadrant after midnight, but lower confidence in these
chances at the moment. Little to no QPF is expected if these showers
should occur. Daytime highs on Thursday expect to be in the upper
60s to middle 70s range while overnight lows drop to between the
middle 30s and the lower 40s.
On Friday, model guidance forecasts the northwesterly flow
continuing as the CWA is between the upper air ridge to the west and
the upper air trough to the east going into the evening. At the
surface, another cold front looks to pass through the region during
the day along with stronger winds with maximum wind gusts around 30
kts in some locations. In collaboration with neighboring WFOs, opted
to blend in some of the NBM 90th percentile for the winds to help
represent these winds in the forecast. A dry airmass moves in with
the cold as seen by the negative 850mb dew point temperatures
advecting in the CWA. Cooler daytime highs can be expected on Friday
being between the upper 50s and middle 60s.
.LONG TERM...(Friday night through Wednesday)
Issued at 1256 PM MDT Wed Oct 4 2023
The long term period will feature a few brisk fall mornings,
followed by a warming trend back to above normal for this time of
year. Along with the warming trend, the area will be drying out,
promoting potential for some increased fire weather concerns next
week.
At the start of the long term period, the area is under
northwesterly flow aloft with the upper level trough axis through
the Great Lakes region and ridging in place across the western
CONUS. Surface high over us will bring clear skies and relatively
light winds, veering from northeast towards the south by Saturday
morning, resulting in chilly temperatures with lows in the upper 20s
to low 30s and potentially the first frost/freeze of the season for
parts of the CWA. Eastward progression of the upper trough/ridge
will have the area beginning to undergo a warming trend Saturday
afternoon with highs in the middle 60s to low 70s.
West-northwesterly flow aloft, mostly sunny skies, and the warming
trend continue Sunday. Morning lows will be in the middle 30s to low
40s followed by afternoon highs in the middle 70s to low 80s. Monday
morning lows will be in the upper 30s to middle 40s before warming
again into the middle 70s to low 80s.
A shortwave trough is then expected to move through during the
Tuesday-Wednesday timeframe with some slightly breezier conditions
possible and a slight chance for precipitation towards Wednesday
evening-night. We`ll see highs in the mid-upper 70s to middle 80s
with lows generally in the 40s to low 50s.
For fire weather concerns, looking at elevated to near-critical
conditions for locations generally along/west of Hwy 27 where RH
drops into the teens Sunday on. Will need to continue to monitor in
case winds start to come up during this period.
&&
.AVIATION...(For the 00Z TAFS through 00Z Thursday evening)
Issued at 536 PM MDT Wed Oct 4 2023
VFR conditions forecast for the TAFs. Main concern was the
potential for LLWS at KMCK. Current data suggest the winds will be
close, but not quite enough to meet criteria. In the 9-12z
timeframe a cold front will move in from the northwest. Behind the
front winds will turn to the northwest. Around 15z the winds will
become breezy.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...076
LONG TERM...CC
AVIATION...JTL
Area Forecast Discussion...Updated
National Weather Service Lincoln IL
754 PM CDT Wed Oct 4 2023
.SYNOPSIS...
Issued at 751 PM CDT Wed Oct 4 2023
Rain is expected to become widespread over much of central and
southeast Illinois later tonight through Thursday, with about a
40 to 60 percent chance of seeing more than an inch of rain east
of I-55. Areas west of the Illinois River should see the rain more
scattered in nature, and the rain threat is likely to end by
midday Thursday. We will switch to a cool northwest flow late
this week, finally bringing more fall like temperatures to the
Midwest.
&&
.UPDATE...
Issued at 751 PM CDT Wed Oct 4 2023
Late this evening, a very slow moving cold front is located roughly
along a Kirksville, MO to Rockford, IL line. A lines of showers
and storms should eventually develop along the front late this
evening or shortly after midnight, while further east, scattered
showers will overspread the remainder of central Illinois
overnight in response to a strengthening low level jet. Main
forecast thinking has not changed much, though timing is a bit
slower than originally anticipated. The best chance for any
thunderstorms will be closely tied to the front where RAP
indicates that weak instability (around 300-500 J/kg MUCAPE) is
present. A few pockets of heavier rain remain possible due to high
PWats (1.39 inches on ILX 00Z sounding) and training of
showers/storms.
Deubelbeiss
&&
.SHORT TERM... (Through Late Thursday Night)
Issued at 305 PM CDT Wed Oct 4 2023
Showers have been struggling to make it into the forecast area
early this afternoon, with surface observations showing them just
starting to move northeast out of the St. Louis metro. Meanwhile,
a line of cumulus has been developing west of the Illinois River,
where skies have been mostly sunny and surface based CAPE`s are
500-1000 J/kg. Recent high-res models have been suggesting a few
showers/storms forming in that area mid to late afternoon, before
lifting into north central Illinois after sunset. Additional
showers and a few storms are also expected overnight in this area,
as the cold front gets closer to the area.
Further southeast, forecast soundings show slow moistening of the
lower atmosphere later this evening, with anything greater than
sprinkles likely holding off in areas near I-57 until closer to
midnight. After that, rain chances ramp up quickly as 850 mb low
level winds bring in moist air at the lower levels. Precipitable
water values around 1.7 inches will lead to some locally heavy
rain at times, north of I-72 after midnight and south of there
Thursday morning. By midday, rain should be mostly done west of
I-55, but will take until early evening to end east of I-55.
Latest NBM guidance shows chances of more than 1 inch of rain
about 40-60% east of I-55 and about 35-50% south of I-70.
Geelhart
&&
.LONG TERM... (Friday through Next Wednesday)
Issued at 305 PM CDT Wed Oct 4 2023
Well advertised lobe of cool fall air still on track to drop
southeast out of Canada late this week. A strong shortwave will
precede it, bringing scattered showers Friday afternoon mainly
north of I-74, and brisk northwest winds will gust from 30-35 mph
at times. In terms of the coolest air, blended guidance is backing
off a bit on temperatures, with about a 35% chance of less than 40
degree low temperatures near/north of I-74 Sunday morning.
Going into next week, the upper pattern still looks to be
dominated by a sprawling upper low centered over southern Quebec,
enhanced as the remains of Tropical Storm Philippe are drawn into
it this weekend. This will keep in a dry northwest flow, with
temperatures still below normal, though not overly so, for Monday
and Tuesday. Temperatures should begin to warm up mid to late
week, with the latest CPC 8-14 day outlook favoring an above
normal temperature pattern, especially west of the Mississippi
River.
Geelhart
&&
.AVIATION... (For the 00z TAFs through 00z Thursday Evening)
Issued at 631 PM CDT Wed Oct 4 2023
A slow moving cold front will approach central Illinois overnight
then pass across portions of central Illinois through the day
Thursday. Ahead of the front, scattered showers and a few storms
are expected overnight into Thursday morning. Ceilings will lower
to MVFR and eventually IFR late tonight into Thursday morning.
Expect some improvement back to VFR as SSW winds turn W/NW behind
the front Thursday afternoon.
Deubelbeiss
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
Area Forecast Discussion
National Weather Service North Platte NE
638 PM CDT Wed Oct 4 2023
...AVIATION UPDATE...
.SYNOPSIS...
Issued at 330 PM CDT Wed Oct 4 2023
Key Messages:
- A Freeze Watch will likely be issued tonight for the potential
for freezing temperatures Friday night.
- The wind gust forecast is for gusts to around 40 mph Friday
morning but later forecasts may need to adjust speeds up.
&&
.SHORT TERM...(This evening through Thursday night)
Issued at 330 PM CDT Wed Oct 4 2023
A weak cold front moving south through MT this afternoon will drift
through wrn and ncntl Nebraska tonight with a fresh batch of Pacific
high pressure building into the region Thursday. Wind speeds across
ncntl Nebraska Thursday get a boost for speeds of 20 to 25 mph.
Lesser speeds are in place south and west. The wind forecast
Thursday leans toward the 500m AGL winds near 25 mph shown by the
models.
The temperature forecast tonight and Thursday is uses a middle-of-
the-road approach for lows in the 40s and highs in the 60s. The
models suggest mid and high clouds will be overhead which would
limit the diurnal temperature range. The temperature forecast
Thursday night leans on the faster RAP model for lows in the lower
30s to around 40. The strong CAA and resulting steep low level lapse
rates make subfreezing temperatures Friday morning unlikely.
Interest turns toward the progress and arrival of a major cold
front. The associated 1034mb high pressure is across AK/NW territory
this afternoon. The models have sped up the arrival time of the
front by about 6 hr. The wind forecast gets boosted toward the NBM
50th percentile which is about 5 mph less than the 90th. Bufkit
suggests the potential for gusts to 40 to 50 mph as the front moves
through with the potential for sporadic stronger gusts. The culprit
is a belt of 60-100kt winds at h700-500mb circulating through nrn
Nebraska and PV1.5 sfc reaching down to near h700mb across ern SD.
The wind gust forecast is for gusts to around 40 mph but BUFkit and
the 12z HRRR suggest gusts to near 50 mph. Later forecasts may need
to adjust gust-speeds up.
There is little change in the projected FGEN the models show across
SD which is the basis for a slight chance of showers mainly after
midnight Thursday. Temperatures aloft could be cold enough for a
brief changeover to snow across nrn Sheridan county. It is worth
noting the front moving through tonight will scour out moisture
below 800mb and this is the basis for the top-down saturation the
model soundings show. Rain chances are limited to 20 percent for
this reason and the nearly dry WPC QPF. Earlier forecasts followed
the wetter ECM and CMC models for 20-40 POPs. The NAM, RAP, HREF and
GFS show a drier forecast.
.LONG TERM...(Friday through Wednesday)
Issued at 330 PM CDT Wed Oct 4 2023
The faster arrival of the strong AK sfc high pressure system
Friday also means a faster departure and the models show the high
could be centered across KS/OK 12z Saturday. The feeling is there
will be enough dry air, high pressure and light winds to foster
freezing weather Friday night into Saturday, even if temperatures
bottom out around midnight. The low temperature forecast Saturday is
conservative for this reason vs the Guidance blend which is several
degrees cooler. A Freeze watch will likely be issued tonight for
this event.
The rest of the extended forecast for wrn and ncntl Nebraska is very
uneventful. An anomalous upper level low will form across the Great
Lakes and James Bay as a nrn stream low absorbs a subtropical low
off the Carolina coast and a separate tropical storm progged to
reach New England in a few days. The result will be a blocked upper
level pattern lasting into next week and uneventful weather across
Nebraska.
&&
.AVIATION...(For the 00Z TAFS through 00Z Thursday evening)
Issued at 633 PM CDT Wed Oct 4 2023
VFR conditions will prevail over the next 24 hours. Winds will be
light and variable this evening then switch to the northwest after
midnight. Winds will become stronger by morning into the afternoon
across portions of the northern Sandhills into north central
Nebraska with gust up to 30 kts possible by afternoon.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CDC
SHORT TERM...CDC
LONG TERM...CDC
AVIATION...Gomez
Area Forecast Discussion...Updated Aviation
National Weather Service Saint Louis MO
1052 PM CDT Wed Oct 4 2023
.SHORT TERM... (Through Late Thursday Night)
Issued at 325 PM CDT Wed Oct 4 2023
Key messages:
1) Scattered showers and thunderstorms are still expected to develop
across central/northeast Missouri and west-central Illinois during
the late afternoon and early evening hours. A few storms could have
small hail and gusty winds.
2) Otherwise, rain chances will increase tonight through Thursday
along and ahead of a cold front crossing through the region. The
highest potential for rain (80-90%) will be south of a Columbia, MO
to Pittsfield, IL line. Strong thunderstorms are not forecast.
3) A secondary cold front will move through the region on Friday
ushering in much colder air. The colder conditions will persist
through the weekend. Still expecting localized areas of frost
Saturday night, especially in low-lying areas and small river
valleys, primarily west of the Mississippi River. Metropolitan areas
and larger river valleys will be largely spared of any frost.
Short term through Thursday Night
Initial round of showers and a few storms continue to slide to the
east northeast across portions of east central/southeast Missouri
and southwestern Illinois. In the meantime, a cold front has moved
into far northern portions of the forecast area. Ahead of the front,
skies have scattered out, allowing the atmosphere to recover and
become a bit unstable as surface dewpoints rise into the low to mid
60s. The latest RAP model run is indicating MU CAPE of 1000 to 1500
J/kg over portions of northeast Missouri and west central Illinois
by 21z Wednesday. However, despite the decent instability and 0 to
6km bulk shear between 40 and 50kts, the forcing along the front is
rather weak. So we could see a few strong storms mainly between 4 pm
and 8 pm (with some small hail and gusty winds to 40 mph), though
most of the activity will remain sub-severe.
With loss of daytime heating, the strong storm threat will quickly
diminish. Rain chances will be on the increase late tonight through
Thursday as another shortwave lifts northeast through the region
interacting with a strengthening low level jet. This combined with
PWs in excess of 1.5 inches will generate decent rainfall rates with
widespread half an inch amounts possible, especially along and south
of the Columbia, Missouri to Pittsfield, IL line. Thus have raised
POPs to categorical in this area for late tonight through midday
Thursday.
The rain will taper off Thursday afternoon/evening as the cold front
exits the region. Highs on Thursday will be in the upper 60s to
upper 70s with the coldest temperatures over southeast Missouri
and southwest Illinois where there is more cloud cover and
precipitation. Lows Thursday night will be in the mid 40s to mid
50s.
Byrd
.LONG TERM... (Friday through Next Wednesday)
Issued at 325 PM CDT Wed Oct 4 2023
On Friday a secondary cold front will move through the region,
ushering in much colder air. With lack of moisture, do not expect
any precipitation with this system. The coldest night will be
Saturday night/Sunday morning with lows in the mid 30s to low 40s as
a surface ridge builds into the region. With the cold temperatures,
clear skies and light winds, could see areas of frost develop,
mainly along and west of the Mississippi River in low lying areas.
Beyond the weekend, as the trough moves off to the east, southerly
flow will return to the region once again with temperatures warming
up back to near normal by Tuesday, with above normal temperatures on
Wednesday.
Byrd
&&
.AVIATION... (For the 06z TAFs through 06z Thursday Night)
Issued at 1049 PM CDT Wed Oct 4 2023
Primary concerns during the 06Z TAF period will be widespread
showers and a few thunderstorms overnight, along with low ceilings
that may persist into tomorrow afternoon.
Widespread showers and at least a few thunderstorms are likely to
impact most local terminals after roughly 08Z, with the possible
exception of UIN, for the latter half of the overnight period and
much of Thursday morning. Showers will linger longest in the
vicinity of STL, which may not see the end of the rain until
after mid day tomorrow. Strong thunderstorms are not expected,
but bursts of heavy rain and visibility reductions are possible,
plus erratic wind gusts.
Otherwise, ceilings have already fallen to MVFR levels in some
areas and will continue steadily lower through the night,
potentially reaching IFR levels. These low clouds are likely to
linger through the morning, and will diminish as a cold front
moves through the area sometime in the afternoon. There is some
uncertainty regarding just how long this will take, and reduced
ceilings could linger for much of the day in St. Louis as a
result.
BRC
&&
.PRELIMINARY POINT TEMPS/POPS...
Saint Louis 67 72 53 67 / 80 90 5 0
Quincy 62 77 49 62 / 40 30 0 10
Columbia 63 76 47 64 / 70 60 0 5
Jefferson City 64 76 48 66 / 80 70 0 5
Salem 64 69 52 68 / 80 90 20 0
Farmington 62 68 51 68 / 80 90 10 0
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...None.
IL...None.
&&
$$
WFO LSX
Area Forecast Discussion
National Weather Service Memphis TN
909 PM CDT Wed Oct 4 2023
...New UPDATE...
.UPDATE...
Issued at 902 PM CDT Wed Oct 4 2023
Some high clouds cover portions of the Mid-South this evening with
temperatures in the mid 60s to mid 70s. A few very light showers
are moving across extreme southern sections of the region at this
time. Currently, a cold front extends across northwest Illinois
through southeast Kansas and into northwest Texas. As the front
moves, a few showers and possibly a thunderstorm or two will move
into western sections of the Mid-South overnight. Will be updating
the forecast to remove evening wording.
ARS
&&
.SYNOPSIS...
Issued at 157 PM CDT Wed Oct 4 2023
Showers will continue to move west and along the Mississippi
River ahead of a cold front. Tomorrow, the cold front will
push through the area and bring more widespread showers and
a few storms throughout the region. Behind the cold front, highs
for the weekend are expected to be in the 60s and lows in the 40s.
&&
.DISCUSSION...
(This evening through next Tuesday)
Issued at 157 PM CDT Wed Oct 4 2023
Upper level water vapor imagery depicts an upper level ridge
pushing off of the East Coast as a broad upper level trough starts
to move in. Showers and a few thunderstorms will continue to form
ahead of a cold front, associated with the main trough, that will
move across the area Thursday and Thursday night.
Isolated to scattered showers are confined to areas west and
along the Mississippi River for today. Due to the lack of
instability, few thunderstorms are anticipated with CAPE values up
to 500 J/kg in east Arkansas. However, NAM model shows
precipitable water(PW) values around 2 inches in that area so
locally heavy rainfall is possible Thursday. QPF values could
reach up to 1.25 inches with the heaviest showers in the Missouri
Bootheel and the most northeastern part of Arkansas. Lower
rainfall amounts are expected as you head south and east towards
northeast Mississippi where only a tenth of an inch will occur.
Following the cold front, temperatures will drastically decrease
15-20 degrees through the weekend. Highs are expected to be in
the 60s and lows in the 40s. Dewpoints are also expected to be in
the 40s due to the cold front advecting drier air from the north.
By Monday, both temperatures and dewpoints will increase slowly as
an upper level ridge starts to build into the region.
&&
.AVIATION...
(00Z TAFS)
Issued at 657 PM CDT Wed Oct 4 2023
VFR conditions are expected to prevail through at least sunrise,
but ceilings will begin a steady decline throughout the morning
tomorrow as a cold front approaches. HRRR guidance is likely
overdoing low ceilings at MEM tomorrow evening (suggesting as low
as 800 ft), but borderline IFR/LIFR conditions at all sites
except TUP is the general consensus by 00Z Friday. Visibilities
may also drop to as low as 4SM along with the low clouds tomorrow
afternoon.
Pre-frontal showers are currently approaching the airspace and
should continue picking up in coverage after midnight. Expect -SHRA
intermittently impacting MEM and JBR through the overnight hours,
eventually becoming more widespread by sunrise. Thunder potential
looks negligible enough to leave out of the TAFs, but an isolated
thunderstorm cannot be completely ruled out as these showers
continue to traverse the airspace. Light southeast winds should
gradually shift to the west and eventually north post-FROPA
tomorrow evening.
CAD
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...None.
MO...None.
MS...None.
TN...None.
&&
$$
PUBLIC FORECAST...GNC
AVIATION...CAD
Area Forecast Discussion
National Weather Service Marquette MI
644 PM EDT Wed Oct 4 2023
.SHORT TERM...(Through Tonight)
Issued at 223 PM EDT WED OCT 4 2023
Highly amplified pattern continues across the CONUS with a pair of
ridges over the eastern Pacific and eastern seaboard/Quebec, with
troughing across the Intermountain West into the Plains states.
These features are gradually shifting eastward. At lower levels, a
1023 mb high is centered over the Mid-Atlantic while a 990 mb low
is analyzed over northern Ontario. Strong lower-tropospheric
south- southwesterly flow continues to maintain an unseasonably
warm airmass over the local area, although the airmass is tempered
compared to the last two days, especially given the mostly cloudy
skies across the central and eastern portions of the CWA.
Coverage of showers has been fairly paltry so far due to weak to
nonexistent surface-based instability and weakening low-level jet
magnitudes. Some CAMs still suggest an uptick in coverage for the
eastern UP later this afternoon, but so far HRRR has had the best
handle on things and it keeps coverage isolated to scattered
(20-40%). We reduced PoPs a bit across the board with an update
earlier this afternoon. Some peeks of sunshine are occurring over
the west half of the UP as a dry slot moves into the area. This is
accompanied by a slight wind shift at the surface from southerly
to southwesterly. The actual system cold front is moving into NW
WI/W LS, and is accompanied by a band of showers with brief heavy
downpours. These will likely work their way across the western
half this afternoon and early evening. It will remain breezy this
afternoon with gusts of 15-25 kt continuing, with some near 30 kt
in the Keweenaw.
Tonight, isolated to widely scattered (20-40% coverage) showers will
continue eastward over the eastern half along the cold front. Skies
should scatter out behind the front with cold advection occurring
and eventually low-amplitude surface ridging building in. The cold
advection will knock low temperatures down from the unusually warm
values of the last couple of nights back to something closer but
still above normal. Lows should range from the mid-40s interior west
to the low 50s along the lakeshores.
.LONG TERM...(Thursday through Wednesday)
Issued at 527 PM EDT WED OCT 4 2023
Key Messages:
-Cold fronts on Thursday and Friday bring rain shower chances and
progressively cooler air masses.
-Below normal temperatures and north winds off Lake Superior bring
lake effect rain showers and clouds Friday afternoon into the
weekend.
Starting with Thursday morning, shortwave ridging keeps the whole UP
dry but an approaching cold front brings rain showers and perhaps a
few rumbles of thunder Thursday afternoon and evening. Instability
is minimal but the relatively warm waters of southern Lake Superior
may add enough extra moisture to enhance activity across the lake.
Cold air advection behind the front results in lake-induced
instability/steep low level lapse rates. The westerly wind direction
is favorable for strong wind gusts on the Keweenaw where the current
forecast advertises gusts in the 30-35 mph range late Thursday
evening and early Thursday night. The period of strongest winds may
be accompanied by lake effect rain showers as 850 mb temps drop to
around 0C, but drying mid-levels and shallow inversion heights
around 4-5 kft suggest light rain rates.
Continued CAA and increasing synoptic scale ascent Friday morning
suggest increasing rain shower coverage. Synoptic scale ascent is
associated with the passage of a surface trough that tracks
southeast across Upper Michigan on Friday. Shower coverage should be
fairly high with this feature and steep lapse rates up to the
tropopause combined with favorable diurnal timing may allow for deep
convection and a few more rumbles of thunder. Considering the cool
environment any stronger updrafts will be capable of graupel or
small hail. There`s also a low-end potential for waterspouts with
the Szilagyi nomogram indicating a marginally favorable environment,
especially near Lake MI where water temps are warmer.
Behind Friday`s trough, 850mb temps cool into the -2 to -4C range
increasing lake delta-T values closer to 20C with lake effect
processes becoming dominant Friday night. Model soundings show the
mid/upper levels drying out by Saturday morning indicating purely
lake effect precip. The lake effect environment slowly becomes less
favorable over the weekend as inversion heights gradually lower and
inverted-Vs gradually raise. However, the upper level low deepens
and phases with a subtropical low on Sunday and shortwaves pivoting
around this amplified low may bring more meaningful rain chances
back into the eastern UP early next week. This low gradually decays
while lingering near the Ontario/Quebec province line before
shifting east late next week. Over the past 24-hours, EPS ensemble
members have trended toward cooler fall-like weather persisting
through next week.
&&
.AVIATION...(For the 00Z TAFS through 00Z Thursday evening)
Issued at 644 PM EDT WED OCT 4 2023
VFR conditions are expected to prevail through the TAF period. A
frontal boundary may bring a few showers Thu afternoon to the taf
sites.
&&
.MARINE...(For the 4 PM Lake Superior forecast issuance)
Issued at 527 PM EDT WED OCT 4 2023
A prolonged period of winds around 30kt will be the main story for
this forecast period with the potential for wsw gale gusts on Thu
and nnw gales Fri aftn thru Fri night. S winds at 20-30kt will
continue ahead of a cold front currently moving over western Lake
Superior. Immediately after the cold front passes, there will be
another short period when a few sw gale force gusts to 35kt are
possible over western Lake Superior (chance of gales is less than
20pct). SW winds diminish slightly overnight into early Thu before
increasing again Thu morning into Thu night as the next cold front
approaches and then passes. Expect the strongest winds over western
Lake Superior after frontal passage Thu aftn/evening. There has been
a slight increase in the risk of gales since the last forecast with
the chc of gales over the w half of Lake Superior Thu aftn/evening
now in the 40-50pct range. If stronger trends continue in the next
round of model guidance, a gale warning may be warranted. A third
cold front passes on Fri, bringing a wind shift to nw Fri then to
northerly Fri night into Sat. The coolest air mass since last spring
follows this front with NW to N gales already in the 40-70% chance
Friday afternoon and night, mainly across central portions of the
lake. Winds diminish below 20 kts across western Lake Superior on
Saturday, but winds of 20-30kt winds will likely continue over the
eastern half of the lake this weekend. A deepening low pressure near
the Quebec/Ontario province line Sunday evening may increase
winds across the eastern lake Sunday night.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
None.
Lake Michigan...
None.
&&
$$
SHORT TERM...Thompson
LONG TERM...EK
AVIATION...07
MARINE...EK
Area Forecast Discussion
National Weather Service Norman OK
1046 PM CDT Wed Oct 4 2023
...New AVIATION...
.SHORT TERM...
(This evening through Thursday)
Issued at 255 PM CDT Wed Oct 4 2023
Isolated severe storms originating east of the dryline on the
Southern Plains will be increasing across CWA west to east with
additional more linear severe convection possible along the cold
front/dryline currently stretched across northwest Oklahoma through
the Texas Panhandle. Ahead of the main/synoptic frontal boundary is
a very moist unstable warm sector with rich moisture in the boundary
layer to fuel storms, while the latest RAP analysis showing moderate
to near strong (2000-3000 J/kg CAPE values off the surface by early
afternoon. Although some high cloudiness but sufficient afternoon
heating to further destabilize/mix a weak to no capped boundary
layer while cooling coming through the upper trough may continue to
steepen mid-level lapse rates. The 12Z NAM run suggests SBCAPE
values up to 3500 J/kg while up to 4000 J/kg with the latest RAP run
all by late afternoon. In addition to moderate to strong
instability, deep-layer effective bulk shear up to 50 kts of will
also be sufficient for storm organization.
With the environment favorable for supercell development, there is
some uncertainty with the timing of the sluggish cold front across
our area which would be provide some of the strongest dynamic
forcing coming through the boundary layer. A general consensus of
the HRRR & NAM have the frontal boundary down to the I-44 corridor
between 5 to 7 PM and perhaps through our entire CWA late Thursday
morning. Certainly severe weather will be ongoing late this
afternoon into the evening hours. This highest risk area where
strong instability may be in place would be across the southwest
quadrant of our CWA, or south of I-40 to just east of I-35. Large
damaging hail up to baseball size will be the primary severe hazard
along with wind gusts up to 80 mph. The severe risk decreases
(slight) along and north of I-40 where hail could still be severe
but perhaps smaller.
An additional hazard would be flooding should any of these heavy
rain producing storms train across each other. With QPF values
exceeding 3 inches across southeast Oklahoma as far west to the
Arbuckles, will have a Flood Watch in effect in that area overnight.
The severe threat should diminish this evening a few hours after
sundown as we lose instability. Storms may continue into the
overnight hours as the upper trough starts moving through but these
are expected to be more elevated and non-severe. Although the
stronger cooling behind the cold front will be in the long term,
will see afternoon temperatures on Thursday returning to seasonably
average.
&&
.LONG TERM...
(Thursday night through next Tuesday)
Issued at 255 PM CDT Wed Oct 4 2023
Our forecast remains dry through early next week with a cooler drier
air mass coming down from the north. Although the main longwave
trough that came through mid-week will be well to our east, a
secondary trough over the Upper Midwest Region of the country will
push another but dry cold front through on Friday. A bit tricky
with Fridays MaxT as NBM is much cooler than the MEX perhaps due to
uncertainty with the timing of the cold front during the afternoon.
As a result, split the difference between the two using the NBM 50th
percentile to slightly warm up Friday closer to the MEX. Either
way, Saturday morning will still feel unseasonably cooler with lows
dipping into the upper 30s across northern Oklahoma to 40s elsewhere
and perhaps even a slightly cooler wind chill (mid-30s) across our
northern CWA. High surface pressure builds in on Saturday with an
upper ridge approaching from the west between an Omega Blocking
synoptic pattern. South winds return on Sunday with a warming trend
and continue into early next week as the upper ridge builds in with
temperatures becoming warmer than average by Monday.
&&
.AVIATION...
(06Z TAFS)
Issued at 1044 PM CDT Wed Oct 4 2023
IFR conditions expected first 4 to 6 hours of forecast across
central and southwest Oklahoma down toward KSPS terminal in post
rain moist environment, ahead of push of drier air associated with
slow moving cold front. Winds expected to back from southeast and
east around to northerly overnight, then helping to usher in drier
air. Mid-upper level trough will begin to move east of region
after 12Z, allowing for clearing skies.
&&
.PRELIMINARY POINT TEMPS/POPS...
Oklahoma City OK 62 77 54 74 / 90 10 0 0
Hobart OK 59 80 52 77 / 80 0 0 0
Wichita Falls TX 64 81 56 81 / 90 10 0 0
Gage OK 51 79 49 71 / 30 0 0 10
Ponca City OK 60 82 51 71 / 70 10 0 0
Durant OK 66 81 58 81 / 100 20 0 0
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...Flood Watch until 7 AM CDT Thursday for OKZ040>043-046>048-
050>052.
TX...None.
&&
$$
SHORT TERM...68
LONG TERM....68
AVIATION...11
Area Forecast Discussion
National Weather Service Pueblo CO
310 PM MDT Wed Oct 4 2023
.SHORT TERM...(This evening through Thursday)
Issued at 217 PM MDT Wed Oct 4 2023
Key Messages:
1) Sub-freezing temperatures expected tonight for the San Luis
Valley.
The latest RAP 500mb analysis indicates a short wave trough axis
extending from northeastern Colorado south-southwestward along the
Front Range and into the Sangre de Cristo Mountains. At the
surface, a broad area of high pressure extends from the Pacific
Northwest southeastward into the area. The latest visible satellite
imagery indicates diurnal cumulus mostly aligned orographically with
the mountain ranges with mostly sunny skies elsewhere. Showers this
afternoon are limited to just isolated coverage with snow showers
over the highest peaks of the southern Sangre de Cristos.
This evening into Thursday, the 500mb short wave trough will
slide southeastward across the area and high pressure will continue
to build in across the region. In the wake of the trough, a dry
northwesterly 500 mb flow will persist across the area. Model
relative humidity time-height cross sections are in agreement,
indicating a deep layer of dry air building in tonight and
persisting through Thursday. This will allow for skies to clear
overnight with light and variable winds expected across the area.
Sunny skies can be expected across the area tomorrow.
For temperatures, there is a good radiational cooling pattern setup
overnight. This will allow for a freeze to occur for the San Luis
Valley and thus the Freeze Warning remains in effect for tonight.
Lows tonight will range from the the lower to mid 20s in the higher
elevations to the mid to upper 20s in the mountain valleys to the
lower to mid 40s in the Plains. With abundant sunshine, models are
in agreement that temperatures will recover nicely across the area
tomorrow and thus the forecast is closest to the National Blend of
Models (NBM). Highs on Thursday will range from the lower 70s in the
Plains to the 60s in the mountain valleys to generally the 40s and
50s for mountain communities.
.LONG TERM...(Thursday night through Wednesday)
Issued at 217 PM MDT Wed Oct 4 2023
Key Messages:
1) Sub-freezing temperatures are possible Thursday night and again
Friday night across the San Luis Valley.
2) Lows on the Plains will fall into the 30s across the Plains
Friday night into Saturday morning.
Models continue to be in good agreement through much of the
extended with generally dry conditions across the region.
Temperatures will be the main concern, especially Thursday and
Friday nights. A warming trend is forecast through the weekend
into early next week.
Thursday night through Saturday...upper troughing over the Ohio
Valley, and upper ridging along the West Coast will put southern
Colorado under dry northwesterly flow during this period. Not
anticipating any precipitation at this this time, and temperatures
will be the main concern. Overnight lows Thursday night will fall
to near 30 across the San Luis Valley. Opted to not issue a freeze
watch given the uncertainty of how low temperatures will fall.
Lows across the Plains will fall into the 40s.
A cold front will arrive Friday morning, with winds shifting
northerly, ushering in cool air. Breezy conditions are forecast
near the Kansas border, where gusts in excess of 30 mph are
forecast. Afternoon highs will be cooler, with most areas on the
Plains reaching the 50s to lower 60s. Winds will weaken throughout
the evening, and skies will be clear. This should help
temperatures fall across the San Luis Valley into the upper 20s,
while lows on the Plains will fall into the 30s. The main issue
will be warm air moving in aloft, which could keep temperatures
from reaching freezing. But, low lying areas along the lower
Arkansas River Valley could dip briefly below freezing
Saturday morning. Those with sensitive outdoor plants may want to
start preparing to protect them. If the warmer air is slower to
arrive, temperatures could fall below freezing.
Saturday, upper ridging will begin to move east into Colorado.
This will allow for warming across the region back into the 70s.
Sunday through Wednesday...upper ridging is forecast to move
across Colorado for late in the weekend and early next week.
Temperatures will warm back into the 70s and 80s each afternoon
across the Plains, and 60s to lower 70s across the San Luis
Valley. Weak energy moving under the upper ridge will help moisten
the region. This will likely lead to isolated to scattered showers
and possibly thunderstorms over the Mountains. This looks
especially true for Tuesday into Wednesday. Mozley
&&
.AVIATION...(For the 00Z TAFS through 00Z Thursday evening)
Issued at 217 PM MDT Wed Oct 4 2023
High pressure will continue to build into the area, allowing
for skies to clear tonight. Thus, VFR conditions will prevail
across the terminals throughout the TAF period. Winds at 5-10
knots will decrease overnight to be variable at less than 5 knots.
Light and variable winds can be expected again on Thursday.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
Freeze Warning from 3 AM to 8 AM MDT Thursday for COZ069>071.
&&
$$
SHORT TERM...WOODRUM
LONG TERM...MOZLEY
AVIATION...WOODRUM
Area Forecast Discussion
National Weather Service Shreveport LA
1003 PM CDT Wed Oct 4 2023
...New UPDATE...
.UPDATE...
Issued at 1002 PM CDT Wed Oct 4 2023
Small update to introduce severe wording to the grids, and in
turn the zones. No other update is needed at this time.
/44/
&&
.SHORT TERM...
(This evening through Thursday Night)
Issued at 241 PM CDT Wed Oct 4 2023
Busy afternoon for the Texarkana vicinity with a good cool pool
now helping to move the heavier rain axis down toward the corner
of NW LA. We have seen inches and inches falling and flowing into
the Red River primarily, but the streets in Texarkana have become
rivers in their own right for some locales. Something we haven`t
had much to worry with lately, but the drought monitor is headed
for the back burner.
A widening area of lower 70s is sitting over SE OK/SW AR/NE TX
and is drifting to the southeastward toward NW LA. This focal
point of development started out as the warm front going
stationary, and now the rain cooled air is expanding a bit. If you
look at the water vapor, it looks like a moisture starved
Pineapple Connection all the way back to the E Pacific over Baja.
Thankfully the heavier axis is shifting southeastward now and
should continue to do so. We have seen rainfall over 5 inches in
a couple of Flash Flood Warnings issued earlier today. The HRRR
was working on moving this rain area all morning toward LA, but it
will only get so far. This model and most short term solutions
show the main push tonight and overnight with more focus for TX
counties eventually. And still the Gulf ridge holds over many
parishes for now.
We have some very warm air in place with low 90s over the LA
parishes well south of I-20, but a great contrast going up along
our I-49 corridor. Shreveport has cooled with some vicinty showers
and the muggy SE winds are a little gusty in places transporting
the rich moisture flow into our four state area. Lows tonight will
be mostly in the mid to upper 60s and highs tomorrow will likely
range in the 70s as the clouds and rain shifts across our region.
The cold front proper will seep in tomorrow, but the winds will be
shifting to the N/NW early behind the overnight convective push.
However, the deeper dry air will take tomorrow all day and evening
to really to work on moving out all of the rain areas. Low temps
tomorrow night will get down into the 50s across I-30 even under
the clouds. A large range of middle 60s along and south of I-20.
/24/
&&
.LONG TERM...
(Friday through next Tuesday)
Issued at 241 PM CDT Wed Oct 4 2023
By Friday morning, a strong surface cold front and the bulk of the
associated showers and thunderstorms should be southeast of the
forecast area. The vast majority of the model guidance pretty much
brings precip to an end by day break Friday. This seems reasonable
as the primary shortwave trough affecting us will also be southeast
of us. However, a northwesterly upper-level jet will strengthen
during the day as a deep longwave trough dives southeast from North
Dakota towards the Ohio River Valley. With the elevated frontal
boundary still across our southern zones, there could still be a few
lingering showers Friday morning southeast of line from Lufkin to
Monroe. Thus, I maintained slight-chance PoPs for this time period.
Rain chances should end entirely by midday Friday, and a dry
forecast is expected for the remainder of the period.
The big story in the long-term period will be the arrival of fall-
like weather during the weekend. The strong northwesterly flow will
drive a cold Canadian surface high southward into the Central CONUS.
Gusty northerly winds on Friday and Saturday will advect the coolest
weather into our area since May. Overnight low temperatures Friday
night/Saturday morning should fall below 60 degrees F areawide and
should cool into the mid 40s in Southeast Oklahoma and Southwest
Arkansas. Saturday night/Sunday morning will be even cooler as winds
diminish below 5 kts combine with clear skis for prime radiational
cooling. Most of the area will fall into the 40s, and I wouldn`t be
surprised to see an isolated reading in the upper 30s in the terrain
of Southeast Oklahoma. Daytime high temperatures on Saturday will
struggle into the mid 60s to lower 70s with the strong cold air
advection. However, temperatures will quickly moderate and warm for
the latter half of the weekend and into early next week. /CN/
&&
.AVIATION...
(00Z TAFS)
Issued at 649 PM CDT Wed Oct 4 2023
Very messy TAF`s are still anticipated over the next 24 hours, as
showers and thunderstorms grow in coverage into the overnight
hours. By 05/06z, look for TSRA and +TSRA at many of our E. Texas
terminals, with that activity moving south and east into the
morning. Widespread IFR CIGs are also anticipated past 05/09z,
and will likely be impacting all terminals by 05/12z.
/44/
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 70 79 65 82 / 90 90 50 10
MLU 69 81 66 82 / 50 80 60 20
DEQ 64 77 57 79 / 100 80 10 0
TXK 66 75 61 78 / 100 80 30 10
ELD 65 75 61 78 / 80 90 50 10
TYR 69 77 65 82 / 100 80 20 0
GGG 68 79 64 81 / 100 80 30 10
LFK 70 80 66 82 / 60 80 40 20
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...Flood Watch until 7 AM CDT Thursday for ARZ050-051-059>061-070-
071.
LA...None.
OK...Flood Watch until 7 AM CDT Thursday for OKZ077.
TX...Flood Watch until 7 AM CDT Thursday for TXZ096-097-108>112-
124>126.
&&
$$
SHORT TERM...44
LONG TERM....19
AVIATION...44