Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 10/12/18
Area Forecast Discussion...UPDATED
National Weather Service Fort Worth TX
920 PM CDT Thu Oct 11 2018
.UPDATE...
Overall, the short term forecast is in good shape. However,
updates were made to overnight and early Friday PoP/Wx grids based
on latest expectations and incoming 00 UTC hi-res NWP.
Generally tranquil conditions were noted this evening across much
of North and Central Texas...but the increase in mid and upper
level clouds signal what will likely be the end of our fair
weather conditions that we`ve experienced over the past 48 hours.
The aformentioned mid/upper level clouds are indicative of
ongoing isentropic ascent and comparison between the 12 UTC Thu/00
UTC Fri FWD RAOB show that this lift has likely yielded an increase
in moisture within the 700-850mb layer. RAP and NAM isentropic
progs show continued lift through the overnight hours with
several SPC HREF members indicating scattered to numerous
convective elements between the 9-15 UTC Friday time frame. I`ve
increased PoPs into the likely category across the Big Country and
towards the Red River Valley with these factors in mind. Thunder
prospects generally look low at this time owing to low amounts of
instability as seen in forecast soundings and while I cannot rule
out a rumble of thunder or two...the overall chances look too low
to include an explicit mention of thunderstorms in the forecast
at this time and rain showers should suffice.
Otherwise, the rest of the short term forecast is in excellent
shape and no other changes were needed. Updated products have
already been transmitted.
Bain
&&
.AVIATION... /Issued 724 PM CDT Thu Oct 11 2018/
00 UTC TAF Cycle
Concerns---Rain potential at all TAF sites. MVFR potential and
wind shift in the D/FW extended.
VFR will prevail through the first 24 hours of the TAF with
easterly winds becoming southeasterly. Speeds should remain at or
below 12 knots. Lift will overspread from the Big Country and
overspread the TAF sites early Thursday morning. Showers will
approach from the west and hi-res guidance indicates that the rain
will be widespread and I`ve prevailed showers at all TAF sites.
Showers appear most probable around 12 UTC at the Metroplex and 18
UTC at Waco. With the dry air at the surface, there`s a chance
for some turbulence below FL070. Showers should come to an end
before Friday evening. Cigs will be between FL050 and FL070.
A front will approach from the north and surface winds should
turn more towards the east and possibly east-northeast around or
after 00 UTC Saturday. This may necessitate a change back to north
flow. These east winds coupled with abundant low level moisture
should facilitate a round of MVFR...possibly IFR cigs Friday
evening. For now, I`ll go with cigs around FL025, but it`s
possible a lower flight condition will need to be advertised in
subsequent TAFs.
Bain
&&
.SHORT TERM... /Issued 352 PM CDT Thu Oct 11 2018/
/Tonight/
The surface high pressure across the Northern Plains leading to
our northeasterly winds will be moving to the east, and allow for
a gradual veering of the winds overnight. The southeasterly winds
will allow for better moisture to stream northward, ahead of a
mid-level disturbance. As the disturbance approaches late tonight,
isentropic ascent will begin to increase, leading to a gradual
uptick in precipitation through the early morning hours.
Given the increasing cloud cover due to the surge in moisture,
low temperatures across Central Texas will not be as cool as last
night. Lows are expected to be in the low 50s across the
northeast, to around 60 degrees across the southwest.
Hernandez
&&
.LONG TERM... /Issued 352 PM CDT Thu Oct 11 2018/
/Friday Through Wednesday/
Low level warm advection in correlation with increasing isentropic
ascent in the 305K-315K layer(or basically 700mb-850mb) will
continue to modify our environment from west-east Friday/Friday
night. This will be in advance of a strong shortwave disturbance
exiting out of our detached upper low over the East Pacific and
strong shortwave energy moving across the Central/Northern Plains
into the Midwest Friday afternoon. Column moisture(PWAT) will
increase quickly to 1.5-1.75 inches across a good chunk of Texas
in response the the aforementioned warm advection by the end of
the day. In addition, the NAM12 (not the GFS) will have a
reinforcement of shallow and cooler low level airmass moving into
our northern counties through the day, but this is not the main
cold front we`ll be experiencing later in the weekend. The
combination of these elements will result in scattered showers
with the ascent from the shortwave enhancing mid level lapse
rates enough for some embedded rumbles of thunder later Friday
morning and lasting until the afternoon. A brief reprieve in
between our lead shortwave and a strong shortwave dropping
southward across the plains can be expected Friday evening, but
it`s not a certainty that all outdoor events or high school
football will be unaffected. Otherwise, the additional shallow
frontal surge across the north and increased cloud cover and
scattered precipitation will result in a wide range of
temperatures for highs Friday. Highs may struggle into the 60s
north of I-20/30, while warming to between 75 and 80 degrees
across our far southern Central Texas counties.
The weekend continues to look very wet, and even potentially
stormy across Central Texas Saturday into Saturday night. Deep and
intensifying warm advection/isentropic ascent occurring in advance
of what will be the remnants of Eastern Pacific Hurricane Sergio
will commence. The GFS looks to bomb surface cyclogenesis across
the Permian Basin and Southeast New Mexico during the day
Saturday, while the NAM12(and European to a slightly lesser
extent) mainly forms a broad and weaker surface low off the lee
of the Davis Mountains in Far West Texas. I believe with the GFS,
it is likely underestimating the shallow cool surge across West
Texas, along with carry low level characteristics from the
Sergio`s remnants that it believes this circulation would survive
the mountain ranges it will be crossing. I will be leaning with
the cooler and wetter NAM12/European blend across our area, with
mid level shortwave energy tracking slightly further south as
Sergio`s remnants get absorbed with the northern stream energy
quickly. If the GFS was to be believed, the entire area would be
warm section with the bulk of showers and thunderstorms being
confined north of I-20 and across the I-40 corridor from Amarillo
to OKC. I just don`t believe this will be the case with the
aformentioned northern stream energy digging south allowing the
shallow front to move well into northern and western Texas.
So what does this mean for North and Central Texas? Well, I
believe a small warm sector will be confined south of I-20 where I
believe if low levels can warm and destabilize enough with
steepening lapse approaching from the west and increasing westerly
effective bulk shear of 40-50 knots, a window for local strong to
severe storms could develop in a corridor south and west of a
line from Comanche, to Hillsboro, to Cameron or Hearne, maybe even
further east depending on the how all these elements transition.
The threat across these areas could linger well into the evening
hours as southerly low level winds in the lowest 1-3km increase
to, or in excess of 20 knots. IF this scenario were to evolve,
that could result in a few shallow, rotating, discrete supercells
across parts of Central Texas late Saturday. What needs to be
stressed here is confidence on evolution, track, and timing of
both surface and features aloft this weekend is not overly high
and forecast changes could change if the initial surface front
either stalls or drives further south than what is currently
forecast. I`m sure more adjustments and changes are to come, but
interests, especially those outdoor activities such as college and
high school football and other events need to be vigilant.
Rain chances will continue on Saturday night, as a strong upper
level jet max near the Red River Valley and embedded mid level
shortwave energy continues interacting with the rich moisture in
place. Best chances should be from the DFW Metroplex northeast to
Paris, with more scattered coverage across Central Texas. A strong
cold front still appears poised to arrive later on Sunday, before
clearing the area toward the Texas Coast Sunday night into Monday.
Mostly scattered rain chances will occur, with the better chances
along the low level convergence due to the strong cold front,
especially Central Texas during this time period. Temperatures
starting off mostly in the upper 50s and 60s will likely only warm
into the 60s across the northwest counties, with 70s in Central
Texas falling in the afternoon.
For Sunday night into the early half of next week, a noticeable
difference in temperatures will be noted behind the cold front
and with an approaching mid level trough resulting in plenty of
cloudiness and off/on post-frontal rainfall Monday into at least
early Tuesday. Highs Monday may not make it out of the mid-upper
40s across the northwest, with the remainder of the area
struggling into the lower-mid 50s with low level cold advection,
precipitation, and zero insolation to assist in diurnal warming.
If you really wanted Fall to arrive, well here ya go!
Lastly and most importantly will be the potential impacts from
consecutive days of rainfall later this weekend into the early
half of next week. Widespread amounts of 2-4 inches and isolated
amounts up to 6-7 inches will eventually begin to run off quickly
due to antecedent and moist soil conditions. Though flash flooding
is not expected to be a "widespread" threat, localized flash
flooding will be possible. In addition, main stem rivers,
especially those on the upper Trinity and Brazos basin are already
responsive and run off into these tributaries will likely occur
quickly after the first inch or more of rain this weekend. This
will likely lead to at least minor, if not a few points seeing
moderate flooding on these tributaries.
It`s not going to be pleasant weather late this weekend into
early next week with brisk, wet, and almost chilly conditions
Sunday night through Tuesday, so prepare for it now. The unsettled
pattern will continue through much of the week, but for now will
keep POPs at low values until details become more clear. Highs
will only modify into the 60s mid-late week.
05/
&&
.PRELIMINARY POINT TEMPS/POPS...
Dallas-Ft. Worth 57 69 61 70 63 / 10 60 40 80 70
Waco 57 77 64 77 67 / 5 20 40 50 50
Paris 53 63 56 66 61 / 5 40 20 60 80
Denton 55 67 59 67 61 / 20 60 30 80 70
McKinney 54 65 58 67 62 / 10 60 30 70 70
Dallas 58 70 62 70 64 / 10 50 40 70 70
Terrell 55 72 60 71 65 / 5 30 40 60 70
Corsicana 57 73 62 75 65 / 0 20 40 50 60
Temple 58 79 65 80 68 / 0 10 30 40 40
Mineral Wells 56 71 60 68 60 / 20 60 40 80 50
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
24/79
Area Forecast Discussion
National Weather Service Hastings NE
958 PM CDT Thu Oct 11 2018
.UPDATE...
Issued at 956 PM CDT Thu Oct 11 2018
Held off on start time of precip, but it is on the way on radar. A
potential frontogenetic band is setting up to the west and
spreading east and perhaps will concentrate in a corridor
including Kearney and Grand Island, but a tough call.
&&
.SHORT TERM...(This evening through Friday)
Issued at 351 PM CDT Thu Oct 11 2018
Aloft: Aircraft obs and RAP model dynamic tropopause analyses
showed low-amplitude WSW flow over the Cntrl Plns...with a shortwave
trof over the Nrn Rckys. This trof will dive SE and quickly cross
the CWA during the AM Fri followed by NW flow.
Surface: 1024 high pres was over Neb/KS at 20Z. This high will drift
E into IA/MO tonight while a weak low and trailing sfc trof move in
and cross the rgn tomorrow. Meanwhile...a warm front will form in
the lee of the Rockies.
Tonight: Becoming cldy. Satellite shows a large area of low clds
overtaking the CWA from the SW at 20Z. These clouds will overspread
the entire CWA. Light rain will develop this evening associated with
large-scale ascent from the approaching trof.
Clds will keep temps from being as cold as this AM. Lows will be in
the upr 30s to near 40. Believe the boundary layer will remain warm
enough to keep precip all rain. RAP/GFS Fcst soundings show there
will be some wetbulb cooling...but the low-lvl column is fcst to
saturate above frzg. The NAM does fcst the temp profile to drop to
near frzg at LXN...but that is after ice leaves the cld.
Amounts: Overall this will be a light rain event most places with
0.10-0.25". However...some models suggest a narrow FGEN band could
be embedded with the larger rain shield. If that occurs...there
could be a narrow strip of 0.50" or so.
Fri: Rain in the AM with rain ending from W-E by noon...then
decreasing clds from W-E late AM into afternoon. Temps will climb
into the 40s/50s...still much cooler than normal.
.LONG TERM...(Friday night through Thursday)
Issued at 351 PM CDT Thu Oct 11 2018
A pattern change will allow temps to return to near normal next wk.
Aloft: The longwave trof will remain over the Cntrl USA thru Mon.
Another chunk of cold air will slide SE out of Canada...associated
with an amplifying trof that will slowly cross the area Sun-Mon.
Once this trof passes...weakening NW flow will prevail thru Wed with
rising heights as split flow develops over the Wrn USA. Uncertainty
increases next Thu and beyond. A cut-off low is fcst to be
meandering over the Desert SW. Some models fcst this low to lift
toward the Cntrl Plns late next week...while others suggest another
trof will dig over the Nrn Plns.
Surface: A warm front referenced above will move thru Fri night as a
Clipper makes its way across Srn Canada. Its trailing cold front
will slam thru late Sun afternoon or eve. Expect a burst of wind in
CAA. Chilly and unseasonably strong high pres (possibly 1035+ mb)
will slide down the lee side of the Rckys Sun and into the Srn
Plns Mon. Another Canadian front (not nearly as cold) is fcst to
move thru Tue...but it may just brush the area and/or quickly move
E of the rgn as warm front Wed. Downslope warming should prevail
Wed-Thu.
Temps: A nice rebound back to near normal Sat...but then another
unseasonably cold day with highs jammed in the 30s to near 40 Sun. A
little recovery Mon but still way below normal...then back into the
50s Tue...and 60s Wed-Thu.
Precip: A little light rain/snow is currently fcst to move thru Sat
night. A small precip shield should develop (as it looks now) and
there will probably be a mix of rain/snow with snow being favored as
cold air rushes in. Where snow lasts the longest...it could
accumulate and this conts to look like this will occur over parts of
N-cntrl KS. Right now the fcst has snow changing back to rain as
temps increase a bit Sun...but this may be optimistic. Once it goes
to snow...it may remain all snow.
This is still more than 48 hrs away...but it currently looks like 1-
2" could occur...possibly up to 3 in a few spots if it comes down
hard enough.
&&
.AVIATION...(For the 00Z KGRI/KEAR TAFS through 00Z Friday)
Issued at 653 PM CDT Thu Oct 11 2018
Ceilings will gradually lower tonight as an upper trough moves
through from west to east. Light to perhaps moderate rain will
likely be ubiquitous late tonight into early Friday morning until
the trough of the upper wave moves east. Rain should fill in
outside of this band and already showing signs of this as the
upper trough approaches.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...None.
KS...None.
&&
$$
UPDATE...Heinlein
SHORT TERM...Kelley
LONG TERM...Kelley
AVIATION...Heinlein
Area Forecast Discussion
National Weather Service Wichita KS
944 PM CDT Thu Oct 11 2018
.UPDATE...
Issued at 944 PM CDT Thu Oct 11 2018
850-700h Warm advection/moisture transport continues to increase
across the TX panhandle as this time, with the latest IR satellite
showing increasing mid level clouds and precip. Latest RAP and
other hi-res models suggest that this warm advection will gradually
increase late this evening and overnight, with saturation leading to
light rain breaking out (or moving northeast) across central KS
sometime after midnight. This advection is being aided by a
shortwave expected to move out of the northern rockies late tonight
and sweep east across the forecast area for the morning hours on
Fri. As the lift associated with the shortwave increases, think the
light rain showers will become more numerous by early Fri morning,
and especially by sunrise Fri. As the lift increases could see some
pockets of moderate rain develop, across portions of central KS and
eventually across SE KS, as warm advection and lift increases.
Latest model guidance suggests that instability will be limited so
not expecting alot of thunder, if any at all. but will leave the
mention in for now. This will thankfully limit the heavier rain
potential, with most locations seeing generally a quarter of an inch
of rainfall by Fri afternoon.
Current timing in the grids/zones looks okay with only minor updates
expected.
Ketcham
&&
.SHORT TERM...(This evening through Friday night)
Issued at 312 PM CDT Thu Oct 11 2018
A broad area of high pressure is situated over the Plains states
this afternoon. Beneath this high, lows this morning fell below
freezing for a few of our far northwest counties thanks to lighter
winds and less cloudcover. Meanwhile, the latest surface analysis
suggests a weak lee-side low is beginning to develop over
southwest Colorado, possibly in response to a weak PV anomaly
ejecting out of the central Rockies. This low may deepen some, but
a lack of more substantial height falls should keep any deepening
at a minimum. East of the low, a modest LLJ will develop by this
evening, with a broad area of WAA developing across much of
Kansas. The increasing low-level flow should aid in quicker
moisture advection with PWats nearing 1" across southern Kansas.
Initially, we should see some increase in shower activity early
this evening within the WAA regime. Later this evening through the
overnight hours, a s/w trough will drop SE out of Montana,
providing at least some enhanced lift/convergence over Kansas.
This should lead to an increased coverage/intensity of the rain,
with one or two bands of moderate rain developing across the area.
Of note, though, the models have backed off some on the lift
associated with this wave and instead of a band of moderate to
heavy rain, we may end up seeing more of a broad area of light to
occasionally moderate rain. Forecast soundings and hi-res guidance
still suggest some banding potential with embedded thunder, but
the greater potential seems to be shifting south of I-70 and east
of I-135. The main takeaway here is that QPF amounts were lowered
some compared to previous forecasts due to the expectation of
somewhat weaker lift/convergence. That said, there is still some
potential for a few locations to see over a half an inch (likely
east-central through southeast Kansas). This is important because
of any implication it could have on river levels/forecasts. For
now, the main impact looks to be slowing the fall of rivers
currently in flood, which would extend, at least briefly, the
flooding impacts. Precip should quickly move out from west to east
late Friday morning through Friday afternoon. Please see they
"Hydrology" section for additional information on the ongoing
river flooding.
Martin
.LONG TERM...(Saturday through Thursday)
Issued at 312 PM CDT Thu Oct 11 2018
The extended portion of the forecast continues to be a complex one
as we deal with the remnants of "Sergio", followed by the
potential of some wintry precipitation.
Tropical Storm "Sergio" has already begun to get pulled northeast
by the larger-scale upper trough that extends from California to
Hudson Bay. Medium range guidance continues to remain in good
agreement regarding the upper level pattern and associated track
of the remnants of "Sergio". As it lifts northeast, it should
transition to a mid-latitude system over the Southern Plains,
producing a swath of heavy rain from Texas through the Ohio
Valley. Model and WPC guidance have all shifted a bit south with
the axis of heavy rain and for now I see no reason to disagree
with this consensus. Ultimately, this should keep QPF amounts
directly associated with "Sergio" on the lower side for our CWA.
As what is left of "Sergio" races east, we should begin to see a
phasing of the northern and southern branches of the jet stream by
Sunday. Meanwhile, an initially shallow cold front is forecast to
surge south down the lee of the Rockies late Saturday into
Sunday. While the exact evolution of the SFC and upper level
features will continue to be refined in coming days, the latest
model guidance suggests an overrunning setup could develop on
Sunday. Within this setup, low-level CAA and moderate precip
rates could lower temps enough for rain to mix with, or perhaps
even change to, a wet snow for a portion of our forecast area.
The coldest air may lag the main precip shield leading to a
somewhat limited opportunity for wintry precip, but synoptically,
the potential is definitely there. Given this is still 3-4 days
out, confidence remains somewhat lower as the wintry potential may
be very much rate- driven and dependent on how quickly the cold
air arrives. Initial thought is that the best opportunity for some
wintry precip will be central Kansas, roughly northwest of a
Great Bend to Salina line, but the latest forecast will reflect
the potential of a rain/snow mix as far south and east as the
Wichita metro. Warmer ground/road temps and temperatures
near/just above freezing will likely be limiting factors for any
accumulation and it is too early to even speculate on potential
amounts (if any occurs at all). Stay tuned...
What is more certain is a shot of abnormally cold air in the wake
of this system, with some records potentially in jeopardy. A
widespread freeze seems plausible as well. The colder air looks
to be short- lived, though, as temperatures should moderate as
return flow ensues.
Martin
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 711 PM CDT Thu Oct 11 2018
Expect deteriorating aviation conditions for the next 6-12 hours.
A mid level disturbance will lead to rain showers moving across
the forecast area late this evening through Fri morning. As the
light rain moves in, expect cigs to initially drop to MVFR, first
in central KS for KGBD, KRSL and KSLN and eventually for
KHUT/KICT. As the showers move east to west across the area,
through the morning hours on Fri, cigs will slowly to drop IFR in
some locations. Some of the heavier showers may also drop vsbys
briefly to MVFR as well.
The system will be quick hitting with aviation conditions improving
across portions of central KS (KRSL/KGBD) by Fri afternoon.
Ketcham
&&
.HYDROLOGY...
Issued at 312 PM CDT Thu Oct 11 2018
The number of river flood and areal flood warnings have gone down,
but significant impacts from river flooding continue. With
a couple more weather systems on the horizon, water levels will be
slow to recede and flooding impacts could conceivably linger
through the upcoming weekend. Please continue to monitor
statements for the most up-to-date information for rivers in your
specific area.
QPF amounts through the weekend look to be in the 0.25 to 0.75"
range, with the highest amounts expected from south-central
through southeast Kansas. Far southeast Kansas could potentially
near or exceed 1", depending on the track of "Sergio`s" remnants.
Martin
&&
.PRELIMINARY POINT TEMPS/POPS...
Wichita-KICT 46 56 40 57 / 80 80 0 40
Hutchinson 45 55 39 56 / 100 80 0 40
Newton 45 53 40 57 / 90 90 0 30
ElDorado 45 53 40 57 / 80 90 0 30
Winfield-KWLD 46 56 40 58 / 70 90 0 40
Russell 42 55 38 59 / 80 50 0 20
Great Bend 43 55 39 58 / 80 40 0 30
Salina 44 53 39 58 / 100 80 0 30
McPherson 44 53 38 57 / 100 80 0 40
Coffeyville 46 54 41 60 / 60 90 10 20
Chanute 44 51 40 58 / 70 90 10 10
Iola 44 50 39 58 / 70 90 10 10
Parsons-KPPF 45 53 41 59 / 60 90 10 20
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
UPDATE...Ketcham
SHORT TERM...RM
LONG TERM...RM
AVIATION...Ketcham
HYDROLOGY...RM
Area Forecast Discussion
National Weather Service Lincoln IL
844 PM CDT Thu Oct 11 2018
.UPDATE...
Issued at 844 PM CDT Thu Oct 11 2018
Most of forecast is fine with clear skies and light winds.
However, this means that temps may drop further than current
forecast...but mainly in southeast IL. So will be updating
forecast for lower temps in southeast IL, which results in more
patchy frost southeast IL and more areas of frost across central
part of the state. Will not be adding more counties to the frost
advisory at this time. Update will be out shortly.
&&
.SHORT TERM...(This evening through Friday)
ISSUED AT 318 PM CDT Thu Oct 11 2018
Skies have cleared across most of the KILX CWA this afternoon,
with partial cloudiness persisting west of the Illinois River.
Any residual clouds will quickly fade away by sunset, followed by
clear skies across the board through the evening hours. Meanwhile,
a short-wave trough evident on 20z/3pm water vapor imagery over
Montana will dive southeastward into Nebraska by dawn Friday. WAA
ahead of this feature will result in increasing mid/high clouds
from west to east well after midnight. Models are showing some
significant timing differences...with the NAM suggesting overcast
conditions arriving at KPIA as early as 09z, while the HRRR delays
the clouds until later Friday morning. Will take a middle-of-the-
road approach here and bring cloud cover into the Illinois River
Valley by 12z/7am while areas further east remain mostly clear.
Thanks to the clear skies and diminishing winds, overnight lows
will bottom out in the 30s. Frost Advisory will remain in effect
for locations along/north of a Beardstown...to Lincoln...to
Danville line where readings will dip into the lower to middle
30s. Clouds will rapidly increase Friday morning, with overcast
conditions expected everywhere by midday. Rain showers will
develop across the S/SW by mid to late morning, then will spread
further east across the remainder of central Illinois during the
afternoon as the atmospheric profile slowly moistens from the top-
down. Due to thick cloud cover and occasional rain showers, high
temperatures will be held in the 40s.
.LONG TERM...(Friday night through Thursday)
ISSUED AT 318 PM CDT Thu Oct 11 2018
Once the wave passes, the showers will end late Friday afternoon
and skies will partially clear Friday night. With temperatures
once again dipping into the 30s, patchy frost will be likely.
Sunshine and slightly warmer conditions will prevail on Saturday
as high temps top out in the lower to middle 50s.
A pair of short-waves will interact early next week to produce a
period of unsettled weather Sunday into Monday. The southern-
stream feature will spread rain across Missouri into far southern
Illinois as early as Saturday night: however, this precip will
remain well S/SW of the CWA until Sunday. Meanwhile the northern-
stream wave will come into the picture on Sunday, resulting in
increasing rain chances Sunday/Sunday night. These features will
settle into the Ohio River Valley, with PoPs lingering into Monday
along/south of I-70. After that, a cool/dry airmass will dominate
for much of next week.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 630 PM CDT Thu Oct 11 2018
VFR conditions will prevail rest of the night, overnight and into
the morning hours. Clear skies will last through the night and
into the early morning hours. However, mid clouds will begin to
move into the area and overspread the TAF sites during the morning
hours after 13z. Cig heights will begin to lower later in the
morning to around 7kft with sprinkles possible...which is covered
with VCSH. Then around noon, or early afternoon in the east,
predominate rain will move into the TAF sites with MVFR cigs
around 2.5kft. Winds will decrease in speed as sunsets this
evening and then become light and variable for the overnight and
early morning hours. Then winds will become west to northwest for
the late morning to afternoon.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
Frost Advisory from 1 AM to 8 AM CDT Friday for ILZ027>031-
036>038-040>048.
&&
$$
UPDATE...Auten
SHORT TERM...Barnes
LONG TERM...Barnes
AVIATION...Auten
Area Forecast Discussion
National Weather Service Charleston WV
722 PM EDT Thu Oct 11 2018
.SYNOPSIS...
Cold front exits east this evening. Much colder air
behind the front will drop lows into the 40s tonight. Cold fronts
cross Friday night, and early next week, then high pressure mid week.
&&
.NEAR TERM /THROUGH FRIDAY/...
As of 715 PM Thursday...
Cold front at 23Z appears to be just to the east of the forecast
area. Strong cold air advection is occurring behind the front,
with a decent temperature drop observed across the area this
evening, with most of the CWA in the 50s. Gusty winds behind the
front will continue for at least the next several hours, but
should generally slacken somewhat overnight, but remain around
enough to prevent any widespread fog formation, although there
will remain the very slight possibility of some patches along
protected waterways. Some clearing is starting to take hold
across parts of the lowlands, but generally, mountainous
counties will continue to have cloud cover linger for much of
the night.
As of 245 PM Thursday...
Cold front exits east of the Appalachians to end pcpn activity
by this evening. Dry and cold airmass behind the front is
evident in model dewpoints dropping into the upper 30s
overnight. Downglide isentropic flow brings cold advection at
the sfc. H850 temperatures drop around 3C lowlands, and into the
minus 2C northeast mountains.
The forecast problem of the day will be whether or not dense
fog would develop over relatively warmer river waters and over
areas that received rainfall overnight. Dense fog formation
will be likely if the sky clears tonight. However, models show
different solutions in sky cover behind the front. MOS guidance,
SREF and WRFnmm suggest clear skies spreading from west to east
across the lowlands overnight. However, the NAM, RAP13, and
HRRR bufkit soundings keep some low level stratus developing
tonight across the lowlands. Believe some light fog could
develop along protected river valleys, while a gentle breeze
will prevent fog from forming elsewhere. ss Friday night, and
early next week, then high pressure mid week.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
As of 300 PM Thursday...
An upper level trough will swing through Friday night into Saturday,
bringing an area of light rain in from the west. Precip could linger
into Saturday morning, especially across the northern mountainous
counties of WV where enough cold air could be in place for some snow
flakes mixing in across the highest ridges. The NAM is the coldest
solution, with 850mb temps dropping into the -2C to -4C range by
sunrise Saturday. The GFS is a bit warmer, on either side of 0C,
with the ECMWF just a touch warmer than that. Did include some
snow in the weather grids, but did not include any accumulation
due to the warm and wet ground.
High pressure will then move in for the remainder of Saturday and
into Saturday night, brining clear and cool conditions. Depending on
how quickly clouds arrive ahead of the next system, frost may be
possible in sheltered valleys in the WV mountains Sunday morning.
The GFS is the fastest bringing moisture back in early Sunday
morning, while the ECMWF and NAM hold off until later in the day.
Temperatures will run below normal through the short term
period.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
As of 300 PM Thursday...
Keeping an eye on a couple features through the long term period.
The first half of the work week looks to be fairly active, with
several upper level waves and a surface cold front working their way
through the middle Ohio River Valley and central Appalachians.
Waxing and waning chances of showers are expected as these features
approach and pass. Temperatures remain warm enough to keep
precipitation as rain.
The second half of the work week looks to be fairly quiet, with high
pressure in place and another round off below normal
temperatures.
&&
.AVIATION /23Z THURSDAY THROUGH TUESDAY/...
As of 720 PM Thursday...
Cold front has moved east of the area, with gusty northwesterly
winds taking hold. Will see somewhat of a decrease in winds
overnight, generally less than 10 kts, although higher terrain
will continue to keep northwesterly winds in the teen to lower
20 kt range. In addition, many lowland taf sites have improved
to VFR, and should generally remain VFR for the remainder of the
TAF period, however, MVFR stratus is expected to linger across
the higher terrain counties through at least 15Z Friday.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z SATURDAY...
FORECAST CONFIDENCE: High.
ALTERNATE SCENARIOS: IFR/MVFR ceilings could last longer behind
the front than currently forecast.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 22 23 00 01 02 03 04 05 06 07 08 09
EDT 1HRLY 18 19 20 21 22 23 00 01 02 03 04 05
CRW CONSISTENCY M H H H H H H H H H H L
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY M H H H L M M H H H M M
EKN CONSISTENCY L H M M L L H H H H H H
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY M L H H H H M M H H M M
AFTER 00Z SATURDAY...
IFR fog possible Friday night through the weekend.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...None.
OH...None.
KY...None.
VA...None.
&&
$$
SYNOPSIS...ARJ/MZ
NEAR TERM...ARJ/SL
SHORT TERM...MZ
LONG TERM...MZ
AVIATION...SL