Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 10/10/21
Area Forecast Discussion
National Weather Service Billings MT
825 PM MDT Sat Oct 9 2021
Latest HRRR and RAP guidance indicating some fog potential
overnight in far SE Montana, and this is backed up by Baker
reporting light fog since 7:30 PM, so patchy fog has been added
to the forecast out there until 6 AM. No other changes to the
Tonight through Sunday night...
Upper level low will move eastward into the Dakotas tonight and
cause any remaining shower activity to diminish. Through this
evening, snow showers are expected over the Bighorn Mountains
above 8700 feet (e.g. near Granite Pass) and isolated
thunderstorms are possible over far southeast MT. Behind this
upper low, an upper level ridge will move into the region
overnight into Sunday and bring dry conditions under mostly clear
skies. The clearing skies could facilitate the development of
patchy fog mainly east of Billings overnight. Low-level winds
look to increase enough later tonight that any fog could be
scoured out by sunrise. High temperatures will generally be in the
50s and 60s.
Sunday night, an upper trough will dig southward over the interior
West and bring large-scale ascent and forcing for some banded
precipitation over south central MT and northwest-north central
WY. Look for precipitation to develop as rain initially over the
lower elevations, including the western foothills, Sunday evening.
Late Sunday night, cooling from the rising air looks to change
rain over to wet snow over the western foothills. Through Sunday
night, conditions will likely be warm enough to limit snow
accumulation to a few 0.1 inch in the foothills. In contrast, the
mountains especially above 5000-7000 feet should receive 1 to 3
inches of snow Sunday night. Low temperatures Sunday night will
generally be in the 30s and 40s, coolest in the foothills and
warmest over southeast MT east of Billings. Temperatures in the
mountainous areas will drop to the 20s. RMS
Monday through Saturday...
Challenging forecast given time of year, ground temps, strength
of system and no cold air advecting into the area. High amplitude
trough will dig over the Western U.S. on Monday with a strong jet
on the back side of the trough. Area will be in a post-frontal
environment with 850 mb temps dropping to around 0 degs C during
the day. Moisture will overspread the region from W to E and rain
will mix with snow in the central and western zones. Western
mountains/foothills will pick up decent snow accumulations with
light accumulations in adjacent lower elevations. Expect several
inches of snow in the NE Bighorns and Pryors as well. NBM had a
60% chance of at least 6 in. of snow for the Bighorns and
foothills. Placed above areas in a Winter Storm Watch beginning
Sunday night. By 00Z Tue., placed Stillwater, Carbon and
Yellowstone in a Watch as well.
By Tuesday, a large upper low will be over the western portion of
the four-corners region. Clusters had .75-1 inch of 24 hr QPF
along the MT/north central WY border by 00Z Wednesday. Also on
Tue., the SOT from the EC EFI showed a 2 for snowfall in this area
with a small area of 5 in WY. NBM had a 50 percent chance of at
least 6 in of snow from Bighorn County W. 850 mb temps were below
zero with highs only in the 30s and 40s. Trowal moves W into MT
supporting high PoPs over the central and E zones, with rain in
the E, a mix in the central zones and snow W. Added Big Horn
County and Sheridan Foothills to the Watch Mon. night.
On Wed., clusters had the low ejecting into NE WY/W SD, NW NE.
Precipitation will gradually taper off from W to E on Wed. A
chance of rain or a mix will linger over the E Wed. night. Ended
the Watch for all zones 00Z Thu. Total QPF on the GEFS mean was
1.5-2.5 inches for the system. NAEFS, EC Situational Awareness
Table and SREF supported the high QPF. Northern tier will get
Area was under troughing on Thursday with mostly dry conditions,
followed by upper ridging for the rest of the period with a
warming trend. Arthur
Clouds will decrease the rest of the night. Most locations will
experience VFR conditions, but local fog is expected over
southeast Montana that could briefly lower conditions to MVFR-IFR.
Beartooth/Absaroka/Pryor/Bighorn Mountains will be obscured. TWH
.PRELIMINARY POINT TEMP/POPS...
Sun Mon Tue Wed Thu Fri Sat
BIL 040/066 037/043 032/036 029/041 030/046 029/049 032/054
00/U 88/O 99/O 74/O 21/B 00/U 00/U
LVM 034/062 030/041 025/038 022/043 024/044 022/050 026/057
01/N 99/O 97/S 32/S 32/S 00/U 00/U
HDN 036/067 036/046 031/038 029/041 028/048 026/051 026/057
00/U 67/R 99/R 85/O 31/B 00/U 00/U
MLS 039/063 041/049 035/044 033/042 032/048 030/053 031/057
00/U 14/R 79/R 87/R 51/N 00/U 00/U
4BQ 041/062 040/050 035/044 033/040 030/044 029/049 029/054
50/U 13/R 79/R 98/R 31/N 00/U 00/U
BHK 038/061 038/052 036/048 035/043 031/047 029/052 030/058
40/U 01/B 47/R 98/R 62/R 00/U 00/U
SHR 034/064 033/047 027/038 026/042 023/046 021/049 024/056
10/U 58/R ++/O 96/O 31/B 10/U 00/U
MT...Winter Storm Watch in effect from Monday evening through
Wednesday afternoon FOR ZONES 34-139-170-173-235.
Winter Storm Watch in effect from Monday morning through
Wednesday afternoon FOR ZONES 40-56-64>66-141.
Winter Storm Watch in effect from late Monday night through
Wednesday afternoon FOR ZONES 57-138-169.
Winter Storm Watch in effect from Sunday evening through
Wednesday afternoon FOR ZONES 67-68.
Winter Storm Watch in effect from late Sunday night through
Wednesday afternoon FOR ZONE 171.
WY...Winter Storm Watch in effect from late Monday night through
Wednesday afternoon FOR ZONE 199.
Winter Storm Watch in effect from late Sunday night through
Wednesday afternoon FOR ZONE 198.
Area Forecast Discussion
National Weather Service Duluth MN
641 PM CDT Sat Oct 9 2021
.DISCUSSION...(This evening through Friday)
Issued at 443 PM CDT Sat Oct 9 2021
An active pattern will occur through next week with several areas
of low pressure bringing showers and thunderstorms to the
Northland. Fog will again be a concern tonight, mainly around Lake
Much of the Northland has seen little in the way of rainfall today
but that will change overnight. As of this afternoon, there were
scattered thunderstorms over far northeast Minnesota with showers
over far northwest areas. An upper low will deepen a surface low
tonight with the low moving to near the North Dakota, South
Dakota, Minnesota border by 12Z Sunday. Forcing will be increasing
quite a bit overnight due in part to strong divergence in the
left front quadrant of an upper jet, a strengthening low level jet
with the RAP forecasting 850MB south/southeast winds to 50 knots
later this evening, and continued warm air advection. Showers and
storms will increase in both coverage and strength overnight with
MLCAPE values per the RAP increasing to 500-1400 J/KG and adequate
deep layer shear as well as low level shear due to the low level
jet. A few severe storms will be possible tonight. The CAMs seem
to have a decent handle on storm mode indicating a line of storms
forming and this is consistent with strong forcing. Damaging wind
will be a threat but with mid-level lapse rates rising to 7-7.5
C/KM, large hail will also be possible. The best chance for strong
storms will be late evening into the early morning hours. In
addition to the severe threat, heavy rain will also be possible
with several rounds of storms moving through and PWAT values
between the 97th and 99th percentiles for this time of year.
Strong storms may be ongoing Sunday morning but they may be far
enough removed from the better instability and be elevated enough
to lower the severe risk compared to earlier in the period. There
will likely be somewhat of a break in shower/storm coverage later
Sunday morning but the nearly vertically stacked low will be over
northern Minnesota by Sunday evening. More showers/storms will
develop in the afternoon under cooler temperatures aloft. A few of
these may become severe again in the afternoon. Lapse rates are
most favorable over the eastern half of the Northland but freezing
levels will be dropping so large hail will be a threat as will be
some damaging wind gusts. The showers/storms will diminish or end
from south to north Sunday night as the low moves into Ontario.
Areas of fog will occur tonight, especially around Lake Superior
and we issued a Dense Fog Advisory for the North Shore into the
Twin Ports area through 10 AM Sunday morning.
Yet another area of low pressure will be on the heels of the first
later Monday into Tuesday bring another round of showers to the
region, with chances highest over eastern portions of the
Northland. Temperatures will remain at or above normal into
The models remain in decent agreement with a third low pressure
system next Wednesday into Thursday. This system will be similar
in strength and track to the one tonight/Sunday. Widespread rain
will be possible with the low but instability is lacking for
widespread thunderstorm chances. Colder temperatures will wrap
behind this low lowering highs to below normal by late week.
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 637 PM CDT Sat Oct 9 2021
Went with a pessimistic forecast given all the low level moisture.
TAFs may be VFR to begin with but there is a lot of potential for
IFR or lower, so hanging onto the lower flight categories and will
ammend up if necessary, but want to give it several hours to play
out. A line of storms will cross overnight bringing heavy rain,
strong winds, and large hail to portions of the forecast area.
LLWS will be present this evening as a strong low spins to our
west bringing in strong flow. More storms follow Sunday.
Issued at 400 PM CDT Sat Oct 9 2021
There are several hazards in the short term including dense fog,
building waves and increasing wind, and strong thunderstorms. Fog
will remain over portions of Lake Superior and it will be dense in
spots. The most likely area for visibilities at or below a mile
will be along the North Shore into the Twin Ports area. We have
issued a Dense Fog Advisory for this area through noon Sunday. A
few thunderstorms will occur late this afternoon into Sunday
evening. Although the risk isn`t high, a few strong storms will be
possible which will produce gusty winds in excess of 40 knots,
hail, and frequent cloud to water lightning. The best chance for
strong storms will be late tonight into Sunday evening. A strong
area of low pressure will move toward the North Dakota, South
Dakota, and Minnesota border by 7 AM CDT Sunday then it will move
north during the day and into Ontario Sunday night. Easterly wind
will increase tonight with gusts of 20 to 25 knots. Waves will
build, especially along portions of the North Shore and we issued
a Small Craft Advisory from Grand Portage to Silver Bay late
tonight into late Sunday afternoon. It`s possible this may need to
be expanded further south.
As the low moves north of Lake Superior, winds will veer to
southwest Sunday night and may become strong enough to produce
hazardous conditions for small craft, most likely along the South
.PRELIMINARY POINT TEMPS/POPS...
DLH 56 66 49 64 / 90 80 50 10
INL 56 66 51 64 / 80 90 70 30
BRD 57 65 47 65 / 100 70 40 10
HYR 58 72 47 65 / 70 50 30 20
ASX 57 75 49 68 / 80 60 50 20
WI...Dense Fog Advisory until 10 AM CDT Sunday for WIZ001.
MN...Dense Fog Advisory until 10 AM CDT Sunday for MNZ020-021-037.
LS...Dense Fog Advisory until noon CDT Sunday for LSZ140>145.
Small Craft Advisory from 4 AM to 4 PM CDT Sunday for LSZ140>142.
Area Forecast Discussion
National Weather Service Fort Worth TX
653 PM CDT Sat Oct 9 2021
...New Short Term, Aviation...
.SHORT TERM... /NEW/
It`s 6:53 p.m. and Texas remains within deep southerly flow as
surface cyclogenesis takes place across the Great Plains. 21Z
surface analysis reveals a 999 mb low centered near Great Bend,
KS. An occluded front extends north of this low towards an
occluding surface low over southeast SD. A dryline extends
southwest from the KS surface low across the OK/TX panhandles and
into eastern NM with the main cold front further to the northwest
across southwest KS and southeast CO. In the upper levels, GOES-E
water vapor channel imagery and earlier 500 mb analysis show a
deepening trough across the Rocky Mountains with strong height
falls noted to the east of the trough axis. The increasingly
cyclonically curved flow and large-scale height falls will enhance
surface cyclogenesis/pressure falls across the Great Plains
through the next 24-36 hours.
Model guidance is in strong agreement that another surface low
will develop over eastern NM by 12Z Sun and track northeast,
reaching southwest OK by 00Z Mon. A cold front/warm front/dryline
triple point will become established near this surface low over
the Sooner State prior to this time. The warm sector to the
southeast of the surface low will be strongly capped initially as
an EML overspreads the region. In addition, gusty south winds can
be expected with a few wind gusts to around 30 MPH likely during
the afternoon hours. While this will be a little short of wind
advisory criteria, these gusty winds will certainly be felt on any
open bodies of water or east-to-west oriented highways.
HRRR and 3km NAM guidance as well as the multi-member HREF are in
strong agreement that convection will erupt near and to the
southwest of this triple point by this time. This convection will
back-build to the southwest down the dryline, reaching western
portions of North TX just after 00Z Mon (1900 CDT Sun evening),
and approaching the I-35 corridor by 02-05Z (2100-2400 CDT).
Forecast soundings ahead of the convection within the warm sector
show strongly curved low-level hodographs and steep mid-level
lapse rates. The strongly unstable environment and robust low-
level and deep-layer wind shear exceeding 60 KT will support
supercell thunderstorms prior to thunderstorms growing upscale
into a QLCS, as convection tracks eastward across North TX and
eventually into Central/East TX. The greatest tornado threat will
likely be to the north of the Red River where low-level flow will
be most backed near the triple point, but some tornado threat will
likely exist into parts of North TX as well. As thunderstorms
grow upscale into a QLCS, the severe weather threat will
transition towards a damaging wind threat, though a lower end
tornado threat may persist even after midnight, particularly near
any bowing segments within the line.
.LONG TERM... /Issued 419 PM CDT Sat Oct 9 2021/
/Sunday evening and Beyond/
Bottom line...Multiple rounds of showers and thunderstorms are
expected this upcoming week starting Sunday evening through
Friday. Some strong to severe storms are possible Sunday evening
and overnight across portions of North and Central TX. A brief
break from the rain is expected on Monday before we see rain
chances increasing again Tuesday-Friday as we stay under an
unsettled weather pattern aloft. The good news is that next
weekend looks pretty nice with below normal temperatures!
Sunday late afternoon and evening...A negatively tilted shortwave
trough is expected to move across the Southern Plains while a
surface low pressure, dryline, and cold front deepen across
southwestern OK and western North TX. Most guidance agrees that
the initial storm development will occur to our west near a
dryline late Sunday afternoon or early evening (between 5-8pm).
Parameter space continues to support isolated to scattered
supercells through the evening before they merge into a line as
they move east/southeastward across North and Central TX Sunday
night. These few initial discrete cells will have the potential to
become severe posing a threat for large hail, damaging winds, and
a few tornadoes. The tornado threat will highly depend on how
long the convection can remain discrete. At this time, most CAMs
agree that the convective mode will transition more into a line
mode as it moves across North and Central TX Sunday night. As
storms evolve into a line/cluster, the QLCS severe wind threat may
increase. This also means that the threat for a few QLCS
tornadoes can`t be ruled out.
One important feature about QLCS evolution is the orientation of
the line to the 500 mb flow. In this case, it looks like the line
of storms will be more parallel to the southwest flow which may
reduce the severe weather threat in some degree. However, we will
have to watch for any surges or bows within the line that could
tilt more north/south or northwest/southeast which will increase
the tornado and/or damaging wind potential. These mesoscale
details will be continue to be refined as new data becomes
available. In terms of timing, the forecast remains fairly similar
that the line of storms is expected to cross the I-35 corridor
around midnight and continue to the east through the overnight
hours. Most the activity should be east of our CWA by early Monday
What we need to do now is prepare and make sure we have multiple
ways to receive warnings. It important to highlight that greatest
potential of the severe storms is expected to occur during the
nighttime hours. Stay weather aware and have a plan before you go
to bed Sunday night.
The weather next week will remain pretty active with multiple rounds
of showers and thunderstorms Tuesday-Friday. A few passing upper
level systems will bring at least scattered showers/storms to our
region. A few strong storms will be possible as our area stays in
the warm sector pretty much all week. We will continue to monitor
the potential for heavy rainfall that could result in some
flooding, especially over those locations that see training
showers and/or multiple rounds of heavy rain. One last cold front
will move across North and Central TX on Friday bringing
seasonably cooler temperatures for next weekend. We could be
looking at highs in the 70s. Stay tuned for updates!
Gusty S winds will continue through the overnight hours as a
strong LLJ develops over the region. This LLJ will transport
moisture northward, allowing CIGs to drop to MVFR at all TAF sites
by 11Z. Winds may be just gusty enough to keep CIGs AOA 1,000 ft,
but very brief IFR cannot be totally ruled out at KACT. CIGs will
scatter out and lift by 18Z. Winds will increase further after
18Z, with sustained winds of around 20 KT with gusts to around 30
KT likely during the afternoon/evening hours. Wind directions will
remain from 170-190, but could begin to veer more southwesterly
just beyond the TAF period.
For the extended portion of the KDFW TAF, TSRA are expected to
develop initially to the northwest of the D10 TRACON area around
00Z, but will approach the TRACON area by 03Z. Despite this being
more than 24 hours away, confidence is high enough to warrant an
introduction of VCTS into the extended portion of the KDFW TAF.
Further refinements in timing are likely with an introduction of
TEMPO TSRA and possibly even prevailing TSRA in later issuances.
.PRELIMINARY POINT TEMPS/POPS...
Dallas-Ft. Worth 69 90 64 83 65 / 0 10 80 0 10
Waco 68 91 64 84 67 / 0 5 80 5 10
Paris 67 88 64 80 61 / 0 5 90 10 20
Denton 64 90 59 83 59 / 0 10 80 0 10
McKinney 67 90 62 82 61 / 0 5 90 5 20
Dallas 70 91 65 84 66 / 0 5 80 5 10
Terrell 67 90 63 83 62 / 0 5 90 5 20
Corsicana 68 91 66 84 66 / 0 5 80 10 10
Temple 67 92 64 85 66 / 0 5 80 5 10
Mineral Wells 64 90 57 83 60 / 0 10 60 0 10
AREA FORECAST DISCUSSION
National Weather Service Hastings NE
956 PM CDT Sat Oct 9 2021
Issued at 955 PM CDT Sat Oct 9 2021
Updated the forecast for late tonight for our far southeast to
bring in small chances of rain in our far southeast as some hi-res
models are indicating we may be clipped from some developing mid-
level frontogenetic forcing.
UPDATE Issued at 423 PM CDT Sat Oct 9 2021
Increased wind/wind gusts in our far northwest areas where good
pressure rises/low-level lapse rates exist with some strong
insolation before sunset. Also raised wind/wind gusts in our far
south where a tighter surface pressure gradient exists for the
next couple of hours. Later tonight as the cold front moves
southeast, I raised northwest wind gusts a solid 10-15 mph as
both the RAP and even more so ECMWF wind gusts indicate
potentially 15 to 30 mph wind gusts, especially associated with
the colder air that lags a bit farther behind the cold front.
Still keeping an eye on precipitation potential tonight with some
elevated instability behind the front and mid-level frontogenetic
banding potential in our far southeast. For now I will leave the
forecast dry as soundings indicate a significant amount of dry air
in the low and mid levels to overcome in order for rainfall to
make it to the ground.
.DISCUSSION...(This evening through Saturday)
Issued at 229 PM CDT Sat Oct 9 2021
The main forecast challenges this period are some short term rain
chances in the far southeast forecast area, and then the
significant weather system still on track for midweek.
Thick high level clouds across the area today have held down
temperatures in most areas, except in the far southeast
and Dawson county where clouds have frayed and thinned on
the edges. Though we are running behind expected 80 degree
temperatures in south central Nebraska especially, afternoon
temperatures in the lower to middle 70s are still pretty nice.
Temperatures have managed to make it into the 80s across
north central Kansas. Currently, low pressure in north
central is trailing a surface trough/windshift into the
western forecast area.
The initial surface front will push through the area the
next few hours and shift winds along with gradually dropping
dewpoints. A much stronger push of northwest winds, dry air
and cooler temperatures will come through during the overnight
hours and clear most of the forecast area. The exception in the
far southeast areas, like Mitchell County. Tightening midlevel
frontogenesis could spark a few sprinkles overnight in the south
but for now have continued to drier trend of only small, light
rain shower chances mainly southeast of a Hebron to Osborne
lingering Sunday and Sunday evening. That rain chance will be on
the sharp northwest side of an upper low moving up and out of the
Southern Plains. The rest of the area will be dry and breezy at
times, especially through the late morning hours before northwest
winds drop in the late afternoon. Temperatures will cool back
closer to season normals for highs.
Monday looks like a real keeper of a day with light winds, low
dewpoints, lots of sunshine and mild temperatures in the 70s.
Things change later Tuesday ahead of a strong upper level low
set move to the northwest of the forecast area Tuesday night
and Wednesday. Moisture is impressively quick given the Sunday
weather system will clear much of the low level moisture out of
the Southern Plains. Models seem to be settling on a warm and
developing breezy day Tuesday before the main shortwave rolls
across the area Tuesday night. The main timeframe of rain and
thunderstorms is Tuesday night and through about mid-morning
Wednesday. The precipitation shield is likely to lift quickly
out Wednesday with rapid clearly behind. Rain amounts could
vary widely, with some areas getting a tenth or two, but other
areas over one-half inch. Strong downward motion on the
south side of the system as it passes will result in gusty
west winds possible up to 40 mph for a time Wednesday afternoon.
Once this system passes, it appears dry and more seasonable
Thursday through Saturday. In fact, it might seem a bit
cool given our recent warm trend, but its really to be
expected for mid October. Overnight low temperatures Thursday
through Saturday morning may drop into the middle 30s at various
locations resulting in frosty conditions. It will really be
the first more widespread frost chances for the season, and
the first such chance of frost since about September 22.
Though just beyond this forecast period, temperatures warm
back up again October 18th and 19th.
.AVIATION...(For the 00Z KGRI/KEAR TAFS through 00Z Monday)
Issued at 650 PM CDT Sat Oct 9 2021
VFR conditions are forecast. Could be a bit gusty with colder air
punching in behind a cold front overnight tonight for a few hours
and then again toward late morning and afternoon on Sunday with
increasing lapse rates. Thick cirrus should start shifting south
Area Forecast Discussion...CORRECTED
National Weather Service Lincoln IL
809 PM CDT Sat Oct 9 2021
Issued at 302 PM CDT Sat Oct 9 2021
Near record-breaking warmth will be observed across central and
southeast Illinois on Sunday as afternoon high temperatures soar
into the middle to upper 80s. After that, a vigorous storm system
will track out of the southern Plains, bringing strong to
potentially severe thunderstorms to the area on Monday.
Issued at 808 PM CDT Sat Oct 9 2021
Steady stream of cirrus continues across the forecast area this
evening, though the thickness is not as prevalent south of I-72.
500-300 mb layer humidity plot off the RAP model keeps this
pattern going much of the night, with skies becoming partly cloudy
over the southeast half of the CWA by sunrise. South/southeast
wind will stay up through the night, generally around 10 mph,
which will keep temperatures from falling much farther than the
65-67 degree range. No significant changes needed to the earlier
Added a Climate section below with record highs Sunday, as well as
record warm lows, both of which will be in jeopardy.
.SHORT TERM...(This evening through Sunday)
ISSUED AT 302 PM CDT Sat Oct 9 2021
A warm front currently draped across central Illinois will lift
northward into the southern Great Lakes tonight. Ample mid/high
cloud cover will accompany the front, but will begin to clear from
south to north across the area late. Given cloud cover and a
southerly wind of 10 to 15mph, overnight lows will only drop into
the middle to upper 60s.
As a cold front slowly approaches the Mississippi River from the
northwest, several CAMs suggest scattered showers northwest of the
Illinois River Sunday morning. Have carried low chance PoPs
along/northwest of a Macomb to Minonk line accordingly. The front
will eventually stall or even retrograde westward during the day
Sunday, so any morning showers will come to an end. The remainder
of the area will see partly to mostly sunny skies along with gusty
southwesterly winds. Thanks to ample sunshine and strong WAA, high
temperatures will climb into the middle to upper 80s...with a few
spots south of I-70 potentially reaching the 90 degree mark.
.LONG TERM...(Sunday night through Saturday)
ISSUED AT 302 PM CDT Sat Oct 9 2021
As has been advertised for the past several days, a significant
storm system is slated to track into the Midwest on Monday. 12z
Oct 9 models are slightly faster with the low track...now taking
it through the Illinois River Valley by Monday afternoon. Given
the faster track, it appears the best focus for potential severe
weather will be along/east of the I-55 corridor during the
afternoon into the early evening. While instability is somewhat
lacking, a powerful low-level jet just off the surface will
enhance directional/speed shear sufficiently to support rotating
updrafts with the storms. 0-3km VGP peaks at 0.3 to 0.4,
suggesting the potential for embedded supercells within one or
more lines of convection expected to form across the area. Based
on these parameters, think the primary severe weather threat will
be damaging wind gusts...although an isolated tornado or two
cannot be ruled out.
Once the low lifts into the Great Lakes, thunderstorms will
rapidly come to an end Monday evening...followed by a return to
warm/dry weather for Tuesday. After that, another powerful storm
system developing over the central/northern Plains will push an
occluded front into Illinois late Wednesday into Thursday. While
instability will be sufficient to support thunder mention, the
strongest forcing/upper dynamics will remain well W/NW of central
Illinois...therefore, the severe risk looks low. Several waves may
track along the front late next week...keeping rain chances alive
into Friday. Once the boundary finally gets pushed eastward out
of the region, temperatures will drop back to near normal for this
of year in the upper 60s by next weekend.
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 621 PM CDT Sat Oct 9 2021
VFR conditions expected through the period. Main forecast concern
will be with the winds. Have continued the LLWS mention overnight
as low level jet ramps up, though surface winds will still be
around 10 knots or so. South winds expected to gust 20-25 knots by
mid morning, and continue through Sunday afternoon.
Issued at 800 PM CDT Sat Oct 9 2021
Record temperatures for Sunday:
Record High Record Warm Low
Bloomington..... 87 (2010) 67 (2018)
Champaign....... 86 (1962) 68 (1949)
Charleston...... 88 (2010) 71 (2017)
Decatur......... 89 (1938) 68 (1949)
Galesburg....... 87 (1962) 67 (1904)
Jacksonville.... 90 (1963) 67 (2018)
Lincoln......... 87 (1962) 64 (1973)
Olney........... 89 (1928) 69 (2018)
Peoria.......... 87 (1938) 65 (1973)
Springfield..... 89 (1963) 71 (1879)
Area Forecast Discussion
National Weather Service Phoenix AZ
438 PM MST Sat Oct 9 2021
.UPDATE...00Z Aviation Discussion.
A low pressure system passing through the region will bring slightly
below normal temperatures and occasionally breezy conditions during
the weekend. Winds will increase Monday ahead of a strong cold
weather system. Sharply cooler conditions will arrive Tuesday with
modest chances of precipitation. A gradual warmup begins in the
middle of the week, although temperatures remain below normal
through the late week period.
Latest RAP streamline analysis reveals a well-defined and
positively-tilted trough across the Sierra-Nevada. Some breeziness
is anticipated this afternoon and evening ahead of this system.
The trough axis will move through overnight, which will reinforce
the cooler and drier than normal conditions Sunday. NBM max
temperature distribution for Phoenix is tightly clustered for
tomorrow, indicating a high probability of high temperatures only
in the lower to mid 80s.
Models remain in good agreement depicting another highly
anomalous trough diving southward and deepening across the Great
Basin Monday. Main impact across the Desert Southwest will
initially be windy conditions ahead of trough Monday afternoon
through early Tuesday. ECMWF EFI values indicate the potential for
strong gusts, particularly across southeastern California Monday
afternoon and evening. GFS soundings also indicate 850 mb winds as
high as 40-50 kt across the Imperial Valley. However, the larger
ensemble including the CMC and EMCWF suites suggest the
operational GFS is likely in the top 10 percent of members.
Nevertheless, a Wind Advisory has been hoisted for the
southwestern corner of Imperial County and the areas just east of
JTNP, though this may be expanded eastward even as far as central
Arizona if current model trends continue.
Latest ECMWF continues to indicate the potential for a line of
showers along the cold front late Monday night and early Tuesday
morning. The grand ensemble suggests roughly a 20 percent of
measurable precipitation in the Phoenix area, though amounts will
be quite light if rain does develop. Better chance for
precipitation will be further north and east towards the stronger
ascent ahead of the low.
Exceptionally cool air will build into the region behind the
front early Tuesday. Latest NBM continues to trend cooler with a
high temperature of only 70 degrees in Phoenix. There is also a
33% chance the high may not even get out of the 60s, though the
all-time record low maximum of 66 degrees appears just out of
Lows on Wed morning will feel quite cold as temperatures drop to
the upper 40s to low 50s in Phoenix, and even the mid 40s in some
lower desert locales. Lows near Globe could fall to near 40
degrees with the low-mid 20s possible at Hilltop.
For the second half of the week Clusters favor broad W-Central CONUS
troughing and dry conditions, followed by a W CONUS ridge by Friday.
This pattern evolution should result in a slow warming trend for the
second half of the week with temperatures remaining below normal in
the 70s on Wed, and the low to upper 80s for later in the week.
.AVIATION...Updated at 2338z.
South-Central Arizona including KPHX, KIWA, KSDL, and KDVT:
No aviation weather concerns expected through the TAF period.
Periods of scattered high clouds will clear fairly quickly by
early evening as west winds prevail well into the overnight hours.
There may be a few instances of gusts around 20-25kt during the
mid evening with a frontal passage, but should have little impact
on operations. The typical switch to easterly should occur much
later than usual early Sunday morning. Extended periods of light
and variable winds may be common Sunday afternoon, but winds
should favor the west by the mid-afternoon. Skies will remain
Southeast California/Southwest Arizona including KIPL and KBLH:
Occasionally gusty winds will be the main weather impact through
the TAF period. A N/NW wind direction will be common through the
evening with some gusts 20-25kt (most prevalent at KBLH). There
may be a tendency for directions to back closer to west overnight,
then potentially be more light and variable Sunday afternoon.
skies will remain mostly clear through the TAF period.
Monday through Friday:
A mostly dry weather system will likely bring sharply cooler
temperatures and very breezy conditions to windy conditions to the
region Mon/Tue. Gusts exceeding 20-25 mph will be likely with even
higher gusts over any exposed terrain/ridgetops possible. Rain
chances are less certain but there is a brief 50-60% chance or so
for <0.10" across the mountains east of Phoenix Mon/Tue. Conditions
will settle down by Wed with a gradual warming trend but with highs
remaining below normal. Winds will then be mostly light and
diurnal/terrain influenced. Otherwise, afternoon RH values will
mostly fall between 12-18% while overnight recoveries reach 30-55%.
.SPOTTER INFORMATION STATEMENT...
Spotters should follow standard reporting procedures.
CA...Wind Advisory from 1 PM Monday to 1 AM PDT Tuesday for CAZ562.
Wind Advisory from 7 PM Monday to 1 AM PDT Tuesday for CAZ561-
Area Forecast Discussion
National Weather Service Blacksburg VA
739 PM EDT Sat Oct 9 2021
Low pressure along the Carolina coast will slowly move north
into Sunday, then push northeast Monday. High pressure will
build over the Mid Atlantic area later Sunday through Tuesday,
bringing drier weather and above normal temperatures by the
middle of next week.
.NEAR TERM /THROUGH SUNDAY/...
As of 611 PM EDT Saturday...
Made some minor adjustments in temperatures for this evening
into tonight utilizing the latest surface obs, their trends and
blended the NBM. The regional WSR-88D images showed scattered
showers and a few thunderstorms mainly in the western
mountains. The HiresW-ARW and HRRR showed convection will
diminish by 03z. More changes this evening...
As of 125 PM EDT Saturday...
Showers exiting by Sunday, sunshine returns.
Surface low off the NC/SC coast early this afternoon will
linger into Sunday, while low closes off at 5h in the same area,
while northern stream low weakens and moves away.
Appears best threat of showers will run its course this
evening, then deeper moisture heads east to the piedmont/coast
tonight, though vicinity of surface low and Atlantic fetch plus
some upper support to keep threat of a few showers around east
of Lynchburg/Danville into Sunday.
Issue tonight will be how much clearing we get and wet ground
leading to fog/low clouds. Appears this will likely occur
along/west of the wedge across SE WV into far SW VA, as think
1-3kft cigs will linger right into tonight and lower further
east despite some breaks appearing this afternoon.
Looking at sunshine mixed with clouds once low clouds/fog lift
Lows tonight will be slightly cooler than the past few mainly
in the west, but still above normal, with lower to mid 50s
mountains to around 60 east.
Although we will see sunshine behind departing system, the
airmass not really changing, so look for warmer temperatures
Sunday as highs run into the 70s, possibly even 80 around
Forecast confidence is average on showers and how east they
push out by Sunday, with above average confidence on temps/sky
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/...
As of 125 PM EDT Saturday...
High pressure and relatively drier air will wedge south into
the area Sunday night. Meanwhile, an upper level ridge over the
western Gulf will stretch northeastward into the Mid Atlantic
region. While under high pressure, the area should not see any
rain, but could see patchy to areas of fog in the morning hours.
There is a very low chance for isolated showers along western
slopes late Tuesday afternoon and early evening as a trough
approaches the region.
Forecast temperatures are a little more tricky, trying to
determine which feature (upper level ridging or surface wedge)
will be the dominate one. The surface wedge appears to be strong
enough early in the period with northeasterly flow helping to
keep afternoon temperatures around normal. As the wedge weakens
and becomes a cut- off bubble high, increasing heights aloft
will bring warmer than normal temperatures Tuesday. More mixing
is expected Tuesday afternoon as a surface trough approaches the
region from the west. Tuesday temperatures will range from the
low to mid 70s across the mountains to near 80F east of the Blue
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
As of 150 PM EDT Saturday...
A new area of high pressure will move over the region Wednesday
following the passing of a surface trough Tuesday night. With
little to no cold air behind this trough, upper level ridging
and abundant sunshine will help temperatures run 10F-15F warmer
than normal through Friday.
The Gulf low is expected to track eastward to Cuba through the
period. If this ridge stays well to the south, a cold front will
cross the region Saturday. If this ridge tracks to the
Southeast coast, as models were showing yesterday, the front may
not enter the area until Sunday. Based on the latest models,
scattered prefrontal showers are possible across the mountains
Friday afternoon/evening. A line of showers will move over the
.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
As of 739 PM EDT Saturday...
Poor flying conditions expected tonight into Sunday. Low level
moisture lingers across the region. Low cigs and pockets of fog
and drizzle expected overnight into Sunday at all sites. KLWB
is the taf site with the best chance for LIFR/IFR fog. Erosion
of low clouds may be slow Sunday but am thinking all sites
should be VFR by end of the taf period.
Forecast confidence is average on ceilings,visibilities and
winds during the taf period.
Extended Aviation Discussion...
A return to VFR this period with high pressure ridge in place,
though could see some late night fog at LWB/BCB. Isolated to
scattered MVFR showers are possible in the west Friday.
Area Forecast Discussion
National Weather Service Shreveport LA
948 PM CDT Sat Oct 9 2021
No major updates are needed to the short term forecast at this
time. RAP13 and HRRR continue to project dry conditions through
the overnight hours, with increasing cloud cover over deep east
Texas as we approach daybreak, based on Gulf moisture being
carried on the southerly flow. Winds will increase in speed
through the day Sunday, with gusts of 15-20 kts possible through
the afternoon. Ingested the latest temperature and dewpoint
obs and interpolated through to 10/12Z, when morning lows will
range from the mid to upper 60s across the ArkLaTex before
rebounding into the upper 80s to lower 90s Sunday afternoon.
.PREV DISCUSSION... /issued 630 PM CDT Sat Oct 9 2021/
For the 10/00Z TAFs, all area terminals will see VFR conditions
persist through the overnight hours, after which increasing cloud
cover brings MVFR cigs to our western zones after 10/12Z. VFR cigs
look to return during the afternoon hours. In advance of more
active weather Sunday evening, winds of 10-15 kts from the south
are expected Sunday afternoon, with gusts of 15-20 kts.
PREV DISCUSSION... /issued 231 PM CDT Sat Oct 9 2021/
SHORT TERM.../Tonight through Monday/
Bottom line up front: The chance for severe weather looks likely,
especially north of I-30 during the overnight hours of Sunday.
Damaging wind and isolated tornadoes will be the main threat with
The first two periods of this short-term will resemble much of
what we`ve seen the last few days. No real weather to speak of,
with temperatures continuing to run above average. The one notable
change in the weather pattern will be a tightening pressure
gradient ahead of Sunday night`s trough. This will allow for some
gusty afternoon winds, and a Lake Wind Advisory will likely be
considered with the next forecast package. Look for afternoon
highs in the upper 80s and low 90s, with overnight lows in the
upper 60s and low 70s for tonight.
Shower and thunderstorm activity will ramp up tomorrow night, as
the aforementioned trough and cold front continues to push east.
While the chance for severe weather looks likely, there are still
some questions regarding the extent of storm coverage and
strength. There is quite the discrepancy in guidance when it comes
to overall instability, and just how far north these best values
make it. For the most part, instability values will be tied to the
best surge of Gulf moisture tomorrow afternoon and evening. From
there, values are dependent upon a sustain southerly flow. Based
on some of the latest CAM guidance, the tail end of the cold front
will stall, allowing for it to become elongated, blocking off
further instability advancement. Wind shear values on the other
hand are rather impressive over a good portion of our area, as
the front moves through the region. The kicker here will be
unfavorable zones of forcing, and storms not being able to fully
tap into this shear in the atmosphere. The best chances for
things to all come together are the areas currently highlighted by
the SPC, which are most locations along and north of I-30. Once
again, given impressive wind shear values, the primary threat with
this thunderstorm activity will be damaging winds. However, the
tornado threat can not be discounted either. Hodographs maintain
quite the veering profile, even with storms expected to quickly
take a linear profile. Additionally, 0-1km shear in much of these
areas are 30+ knots during the prime storm timeframe. Once again
mentioning the storm`s linear profile, this would mean the
tornado threat would be embedded in the advancing QLCS, going
along side with the wind threat.
Shower and thunderstorms will become sub-severe as the morning
progresses, with lingering thunderstorm chances remaining into the
day on Monday. Behind the front, look for afternoon high
temperatures on Monday to range in the upper 70s to low 80s.
.PRELIMINARY POINT TEMPS/POPS...
SHV 67 91 71 85 / 0 0 60 30
MLU 65 89 71 86 / 0 0 20 40
DEQ 63 89 63 81 / 0 0 90 20
TXK 68 89 68 83 / 0 0 80 20
ELD 64 87 67 82 / 0 0 50 40
TYR 68 90 66 83 / 0 0 90 20
GGG 66 90 66 84 / 0 0 80 20
LFK 67 91 70 87 / 0 0 70 30
...Update to aviation forecast discussion...
Issued at 341 PM CDT Sat Oct 9 2021
There are two systems of interest in this forecast package that look
to bring thunderstorms and heavy rain to the area.
For starters, today has been an unseasonably warm early October day
across the region. At 20Z, many locations had warmed to 90 degrees
within a zone of strong southerly flow. Looking at the synoptic
setup across the country, upper level water vapor imagery is showing
an elongated trough extending from the Intermountain West to the
central California coastline. Within a stream of moisture ahead of
that trough, a thick batch of cirrus clouds had been in place
over much of the CWA today. Surface obs at 20Z show a 1000 mb area
of low pressure in central Nebraska and breezy southwesterly winds
in eastern Kansas.
Tonight, the western trough will split into two waves. One will
traverse the north-central US. That will cause the surface low to
move northeast, bringing an associated surface front into eastern
Kansas. Meanwhile, the southern stream wave will work across the
Four Corners and then across the Texas panhandle, Oklahoma and
into eastern Kansas Sunday and Sunday night. Have gone with slight
chance POPs early Sunday morning north of a line from Abilene to
Hiawatha where CAMS continue to show a signal. POPs then increase
area-wide by late afternoon as the southern stream wave and
associated surface low lifts into the area. The RAP shows about
1000 J/kg of SBCAPE developing near Anderson Co by 00Z Monday, but
the HRRR is slightly further south with that instability. HREF
only shows about 500 J/kg of MUCAPE developing near and south of
Interstate 35 as storm chances increase. If the higher instability
values can be realized, there will be a risk for severe
thunderstorms initially given effective bulk shear values around
50 kts. Heavy precipitation is the more likely hazard, especially
south of I-35 where up to 2.0 inches of rainfall could occur late
Sunday into Monday morning.
Our first system clears the area on Monday while the next one
deepens over the western CONUS. Rapid lee-cyclogenesis is forecast
to occur late Monday and Tuesday, and rich theta-e air will advect
back into Kansas on Tuesday. Long range models are not in great
agreement at this range on the timing of increasing POPs, but am
thinking that storms could develop in central Kansas Tuesday
afternoon, where severe weather could occur. Rain and
thunderstorm chances will increase in eastern Kansas Tuesday night
with another round of heavy rain possible. This looks like a very
dynamic system, so trends will be watched closely given timing
differences and the potential for another round of severe weather
for parts of the region.
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 639 PM CDT Sat Oct 9 2021
VFR continues this period. As sfc winds diminish this evening,
LLWS is expected to develop at TOP/FOE with a 45-50 kt LLJ
developing around 01Z. A frontal boundary approaches overnight and
causes the jet to weaken, and then brings a wind shift to the
northwest during the morning hours. There could be a few isolated
showers in the area during the morning with increasing chances
through the day, but confidence doesn`t become high enough to
introduce into the TAFs until the very end of the period. Have
held off mention for now, but will need to monitor for inclusion
in future issuances.
Issued at 302 AM CDT Sat Oct 9 2021
Very high fire danger is still forecast for parts of north
central Kansas this afternoon. However winds may not be as strong
as previously forecast with the stronger pressure gradient setting
up further to the east. Nevertheless southwest winds of 10 to 20
MPH with higher gusts along with RH values in the 20 to 25 percent
range look to create very high fire danger. Over east central and
northeast KS, minimum RH values should be higher around 30
percent and mitigating the fire danger somewhat. In any case, land
managers continue to report fuels are not critical with one and
ten hour fuel moisture in the 20 to 30 percent range. So will keep
the fire danger in the high to very high range and call for
avoiding outdoor burning.
Area Forecast Discussion
National Weather Service Tulsa OK
907 PM CDT Sat Oct 9 2021
A trough is very evident across the desert southwest with the
base of the trough located across southern CA into S NV and W AZ.
A small amount of riding was noted over the southern plains which
has loosely led to temperatures being well above normal. Ft. Smith
actually set a record high this afternoon with a temperature of
95. Dew points were relatively low this afternoon which helped
temperatures warm up quickly and allowed it to feel not quite as
hot. The moisture is still located deep in the Gulf but the latest
Total PWAT satellite imagery is showing the moisture starting to
push northward with southerly flow through 850mb. This will be the
fuel and the aforementioned trough will be a key ingredient for
our likely severe weather outbreak for tomorrow late afternoon,
evening, and overnight.
Taking a step back, the rest of this evening and overnight will
see elevated southerly winds overnight across the area thanks to a
tight surface pressure gradient. Winds will not be as gusty as
this afternoon, but expect winds to still be in the 10 to 20mph
range under partly cloudy skies. Lower clouds, signifying the
initial arrival of Gulf moisture, will likely start moving into SE
OK late tonight into early tomorrow morning. Dew points will
noticeably increase through the night with dews likely in the low
to mid 60s by sunrise.
Our attention then turns to the severe weather threat for
tomorrow afternoon. Overall, a significant severe threat is still
expected to impact most if not all of the area to some degree. ALL
SEVERE HAZARDS WILL BE POSSIBLE! Flash flooding will also pose a
threat as well. Taking a look at some of the details, the upper
wave will begin to become negatively tilted as it swings through
the region late Sunday into Monday which will help to strengthen
the surface low pressure thanks to enhanced divergence aloft. At
the surface, a cold front will slowly progress eastward across
central OK through the morning and afternoon. Look for this front
to initially trigger storms by late afternoon across west-central
and/or southwestern OK. Just ahead of the front, there will be
gusty southerly winds. These moisture-rich southerly winds will
allow for moisture pooling to occur along and just ahead of the
front which will locally enhance dew points and, perhaps more
importantly, will locally enhance CAPE values. These CAPE values
will need to watched as they will play an important role in the
significance of this severe weather outbreak. HREF mean for SBCAPE
is indicating values of 750 to 1000J/kg north of I40 in E OK
while locations to the south of I 40 in E OK are seeing values in
the 1000 to 1500J/kg. W AR SBCAPE values are a little lower but
still a modest 500 to 750J/kg. HREF max is indicating values of
1000 to 1500J/kg for NE OK, 1500 to 2500J/kg for SE OK, and 1000
to 1500J/kg for W AR. SREF is also in pretty good agreement with a
50 to 60% chance for greater than 1000J/kg across E OK with a 20
to 30% chance across for W AR. These lower values are largely
thanks to relatively poor mid level lapse rates of 6 to 6.5C/km
(some isolated pockets of 7C/km map be possible though SREF only
gives it a 30% chance at best for E OK with much lower chances for
W AR) with the low level lapse rates roughly the same by the time
the storms arrive. This is all indicative of a fairly low large
hail threat overall but the threat is definitely not zero.
The severe ingredient that is going to dominate and drive this
event by far will be the shear. Shear will be more or less off the
charts which means even marginal instability will sustain any
strong to severe storms. The 500mb trough swinging through will be
compact/potent with an 80+kt jet rounding the base Sunday night
into early Monday morning. Taking a look a little lower, we see
very strong 850mb flow (likely as a result of a strengthening low
as the mid level trough becomes negatively tilted) with winds from
the SSW in excess of 60kts over much of E OK and NW AR with some
locations (mainly NE OK) in excess of 70kts. At 925mb, strong flow
is still observed with 35 to 45kts from the south. At the
surface, especially ahead of the cold front, winds will be from
the south (likely some easterly component) at 10 to 15kts Sunday
evening/overnight. These winds can be see well with the use of a
forecast hodograph. One thing to really pick out from these winds
(especially the 850mb winds which is only about 1km AGL) is the
potential that these could translate to the ground if a strong
enough storm were redirect those winds which is entirely
reasonable. Thus damaging wind gusts of 70mph (maybe in excess?
More data is needed) will be very possible. Forecast hodographs
over the past few days have continued to be rather impressive with
rather large classic looking cyclic profiles The latest guidance
from a variety of models is in good agreement with 0-1km SRH
easily in excess of 200m^2/s^2 during the evening and overnight
hours. These values could exceed 300m^s/s^s by late evening as the
low level jet really begins to crank up. The 0-1km SRH appears to
be highest from about I-44 and southward for the late evening and
overnight timeframe. The mean HREF is also supportive of this
data as well. The 0-3km SRH presents slightly higher values (as
expected) across the area but offers a secondary area to watch
closer to the track of the surface low as it translates NE along
the cold front. Severe storms near the track of the surface low
may also benefit from slightly steeper lapse rates and thus a
greater potential for large hail. The 18Z HRRR run shows the
possibility of a stronger storm moving along I-44 into NE OK. As
Im finishing up this AFD it appears the 00Z HRRR is pretty much
in line with what the 18Z had. As it stands now, there appears to
be 2 areas of heightened concern (SE OK and NE OK) when it comes
to the overall tornado threat. Paintball plots from the HREF show
a cluster of UH > 75m^2/s^2 tracks across NE OK into NW AR. With
the threshold bumped up to 150m^2/s^2 we notice fewer paintball
plots but a somewhat disorganized cluster of NE OK. This data
seems to indicate that severe storms across NE OK could be
significantly severe thanks to aid from the nearby low. One thing
to note will be as the storms progress eastward into an increasing
low level jet, it will not take much for mesocyclones to develop
within the line of storms across E OK and eventually NW AR. The
instability may be lower for NW AR but there will be more than
enough shear (especially by the time the line arrives in NW AR)
for storms to maintain strength. There will likely be a few spin
ups/QLCS tornadoes that develop within the line during the late
evening and overnight hours across E OK and NW AR. The HRRR and
the HREF paintball plots show spotty enhanced tracks across E OK
into NW AR indicative of brief mesocyclones developing within the
line. Unfortunately these kinds of tornadoes can be very difficult
to detect on radar thus it is very important that EVERYONE ACROSS
E OK AND NW AR BE WEATHER AWARE TOMORROW EVENING/OVERNIGHT AND
HAVE A PLAN READY TO GO!
Taking a quick look at the flash flood threat, we notice enhanced
forecast PWAT values near 2" (easily in excess of the 90th
percentile for this time of year) across E OK and NW AR during the
evening and overnight hours with heighten values likely across NE
OK. This will translate into highly efficient rainfall rates with
any storm that develops. Rates of 1 to 2 inches per hour will be
common with some rates of 3 inches per hour (perhaps briefly
higher) being possible. The area to watch will be NE OK,
especially for locations along and northwest of the low track.
This area will likely see several rounds of storms training over
the same area which will lead to locally enhanced amounts and may
result in localized flash flooding. A Flash Flood Watch may be
needed if future forecasts become confident in an area of locally
very heavy rainfall. Locations, mainly south of I-44, will see a
line of storms that will bring heavy rainfall (in addition to the
aforementioned severe weather threat) but should be in and out
relatively quickly with minimal time for rain to accumulate. With
that said, there could still be localized flash flooding problems
as well given the very high rainfall rates that are possible.
A quick recap all modes of severe weather are possible
tomorrow across E OK and NW AR. The primary severe weather
hazards will be damaging wind gusts and a few tornadoes. Large
hail will be a lower threat though may be enhanced closer to the
surface low across NE OK. As for timing, storms may enter the
western portions of the CWA (NE OK portions) as early as 6PM. A
NNE to SSE roughly oriented line will likely be established west
of the CWA before it progresses eastward across CWA. Rough timing
to a line between Miami and Hugo is 10 to midnight and midnight to
3AM for the storms as they cross into NW AR. Keep in mind there
are still some uncertainties in timing and surges within the line
of storms could allow storms to arrive sooner at any given
location than expected. The other threat to monitor will be the
threat for heavy rainfall. Locations along and to the northwest of
the low track could see training storms which combined with the
highly saturated environment could lead to locally heavy rainfall
which may result in flash flooding. Stay safe and be weather
.PRELIMINARY POINT TEMPS/POPS...
TUL 70 88 60 78 / 0 40 100 10
FSM 67 90 64 79 / 0 10 90 20
MLC 67 87 59 78 / 0 10 100 10
BVO 67 87 58 75 / 0 50 100 10
FYV 63 86 59 75 / 0 10 90 30
BYV 67 85 61 73 / 0 0 90 40
MKO 67 85 60 75 / 0 20 100 10
MIO 69 85 60 73 / 0 20 100 30
F10 67 87 58 78 / 0 30 100 10
HHW 67 87 62 78 / 0 10 90 10