Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 10/09/18
Area Forecast Discussion
National Weather Service Amarillo TX
633 PM CDT Mon Oct 8 2018
00Z TAF Cycle
VFR conditions at all three TAF sites will become MVFR and even
IFR to LIFR after 02Z to 04Z Tuesday through 00Z Wednesday as
showers and thunderstorms track across the the Dalhart, Guymon and
Amarillo TAF sites. East and southeast winds 5 to 15 knots will
become north 10 to 20 knots with gusts near 25 to 30 knots after
02Z to 07Z Tuesday.
.PREV DISCUSSION... /Issued 402 PM CDT Mon Oct 8 2018/
SHORT TERM...Through tonight
PREV DISCUSSION... /Issued 137 PM CDT Mon Oct 8 2018/
Storms have shifted focus to the east as expected. There is some
clearing east of a trough that could allow a few discrete cells to
form out that direction and the HRRR shows a few popping late
this afternoon. This will have to be watched given continued high
bulk shear and low LCLs that could lead to some quick spin- ups.
Forecast sounding do show some veer/back/veer to the profiles, so
it isn`t a textbook profile. As has been the case the last two
days, the marginal instability should be the key that helps save
us from a more significant/widespread severe event.
Otherwise we may head into a slight lull, but arguably
the strongest upper dynamics of the event will swing across the
area overnight leading to another complex or storms that sweeps
across the area from SW to NE between midnight and sunrise for
most. Minimal instability may have limit the svr potential (per
the marginal to slight risk favoring the SE), but hi-res model
agreement on on more significant complex of rain and storms moving
across the area as the front approaches and moves through makes
Updated grids a bit earlier to account for the timing and trends
above and also raise POPs in the east/NE.
LONG TERM...Tuesday through Monday
Cold front will clear all of forecast area by Tuesday morning,
with clouds and cooler conditions expected. Additional strong
dynamics with incoming shortwave trof will assist in precipitation
production in regime of isentropic lift. Highest pops will be in
northeast where richer moisture will linger near mid-level
circulation. Lowest pops in southwest where drier air expected
to create semblance of an intruding dry slot. Precipitation
expected to end by Tuesday evening.
Tuesday night will be cold as surface high pressure ridge settles
into area. Lows Wednesday morning in the lower- to mid-30s
expected for the northwest 1/3 of the forecast area.
Next mid-level trof takes shape Wednesday and Wednesday night
across the Great Basin, with southwest flow aloft resuming over
Panhandles. Remnants of Hurricane Sergio in eastern Pacific get
ingested into this southwest flow, with moisture and circulation
expected to impact West Texas mainly Friday night and Saturday.
TX...Flood Watch through Tuesday morning for the following zones:
OK...Flood Watch through Tuesday morning for the following zones:
Area Forecast Discussion...UPDATED
National Weather Service Austin/San Antonio TX
927 PM CDT Mon Oct 8 2018
New showers and thunderstorms have developed south of Bexar County
the last hour and now affecting parts of Bexar County and areas along
the I-35 corridor. Looking at the latest water vapor images, there
is an upper level short-wave moving across the southern part of
south central Texas where the activity is taking place. Also, the SPC
Mesoscale Analysis website points out to an area of upper-level
divergence right over the area where the upper level wave is moving
across and lineup well with the I-35 corridor. Latest HRRR model
guidance suggest for this activity to continue through late tonight
with another pulse of energy coming across over same areas
overnight. There could be pockets of 1 to 2 inches of rainfall with
stronger storms as pwats remains between 1.8 to 2.0 inches over those
Things out west are not bad at this present time with only one
cluster of strong storms barely touching the northwest part of Val
Verde County. This situation may not last long as things get
interesting close and after midnight tonight as the main upper level
disturbance over the four corners region moves to the northeast.
Expect the threat for heavy rain and flash flooding to continue
overnight as the severe threat diminishes.
.PRELIMINARY POINT TEMPS/POPS...
Austin Camp Mabry 72 83 66 83 60 / 40 70 50 10 -
Austin Bergstrom Intl Airport 72 84 66 83 59 / 40 70 50 10 -
New Braunfels Muni Airport 73 83 66 84 60 / 40 70 50 10 -
Burnet Muni Airport 71 80 61 81 56 / 50 80 40 - -
Del Rio Intl Airport 71 84 63 86 66 / 80 60 10 - 10
Georgetown Muni Airport 72 82 63 81 57 / 40 70 50 - -
Hondo Muni Airport 73 84 65 86 61 / 50 70 40 10 -
San Marcos Muni Airport 73 83 67 84 60 / 40 70 50 10 -
La Grange - Fayette Regional 74 86 69 85 61 / 40 60 50 10 -
San Antonio Intl Airport 73 84 67 85 61 / 40 70 50 10 -
Stinson Muni Airport 74 84 68 86 63 / 40 70 50 10 -
Flash Flood Watch until 7 AM CDT Tuesday for Bandera-Edwards-Kerr-
Flash Flood Watch through Tuesday afternoon for Gillespie-Llano.
Area Forecast Discussion
National Weather Service Fort Worth TX
1041 PM CDT Mon Oct 8 2018
A strong warm and moist air advection regime continues to supply
North and Central Texas with sufficient moisture and lift to
allow showers to continue well into the evening hours. An overall
weakening trend is expected for the activity lifting north along
I-35, but the high coverage of light precipitation warranted a
grid update to increase POPs for tonight. Meanwhile, a line of
thunderstorms just west of the forecast area is showing signs of
weakening as it approaches our western counties. However, its
outflow boundary is about to collide with the northwestward-moving
outflow which pushed through the Metroplex earlier this evening,
which may cause an increase in convection for an hour or so across
the western row of counties. Likely POPs have been moved up in
time for this reason for the west and northwest. Brief heavy rain
and localized flooding will be the primary concern with this
Additional thunderstorms will organize out west and approach the
area Tuesday morning ahead of the strong upper trough over the
Four-Corners region. Likely POPs will remain in place for areas
along and west of I-35 Tuesday morning, with a few strong to
severe storms possible. At this time it still appears that the
better severe threat will occur Tuesday afternoon and evening when
the best instability will be in place.
.AVIATION... /Issued 742 PM CDT Mon Oct 8 2018/
00 UTC TAFs
Concerns---Short term rain/thunder potential at all TAF sites.
Return of MVFR stratus overnight into Tuesday morning along with
rain/storm potential through the day.
Showers and a few storms continue to lift northward this evening
between ACT and the Metroplex TAFs. Total lighting information
indicates that much of this activity is losing some of its vigor
and given the loss of daytime heating plus earlier storms across
the Metroplex, I`ll abstain from a VCTS mention at this time and
advertise SHRA. If activity persists a little longer, I`ll include
a brief 2-3 hour period of VCTS at Metroplex TAFs. Regardless, impacts
to southbound traffic and the Glen Rose/Cedar Creek cornerposts
do appear probable. Storms have cleared Waco, but a few showers
will remain possible through the overnight hours.
MVFR stratus is expected to blanket the area during the overnight
hours with cigs falling to near FL012. Given the moist airmass, I
wouldn`t completely rule out a few brief periods of IFR,
especially at Waco. At this time, however, the potential is too
low to include. Storms appear like a good bet at Metroplex TAFs
between 1500 and 1900 UTC and will likely have some impacts on the
Tuesday morning to early Tuesday afternoon push. There should be
a brief reprieve from the potential for TS in the afternoon
before another round of TS develops to the west during the evening
at the Metroplex. At this time, it appears that the most likely
window for this second round of convection will be between 0200
and 0400 UTC Wednesday. At Waco, storms will likely re-fire in the
afternoon, closer to 2000 UTC Wednesday. Surface winds will
become westerly Tuesday evening before becoming northwesterly
around midnight with a potential for post-frontal MVFR stratus.
.SHORT TERM... /Issued 355 PM CDT Mon Oct 8 2018/
Another afternoon of showers and thunderstorms is underway as we
remain positioned downstream from a deep upper trough. Lift from
this system has contributed to a broad area of convection across
the western portion of the forecast area, as well as isolated
convection farther to the east. This trend should continue for the
next few hours before activity wanes later this evening. Through
the peak heating hours, a couple strong storms will be possible,
mainly due to the presence of strong surface based instability.
SBCAPE values are 1500-2000 J/kg across much of the forecast area,
where some breaks in the clouds have contributed to surface
heating. Moderate shear values and unidirectional profiles should
continue to limit the organization of strong or severe storms.
However, strong winds would be the main hazard with more robust
convection, along with brief heavy rain and lightning. Otherwise,
the broad area of showers and isolated storms ongoing from Killeen
to Gatesville should make northeastward progress towards the I-35
corridor later this evening, while also weakening.
Overnight, a potent shortwave digging through the upper trough
will generate a large complex of thunderstorms across West Texas
which will move towards our western counties prior to daybreak.
Some of this convection may reach strong/severe limits at times
with predominantly a wind threat. However, its intensity may be
declining after it enters our forecast area as it outruns upper
support to the west. Heavy rain and flooding will also be a
concern early Tuesday morning, especially if this line was to
slow down or stall, causing cell training to occur. The evolution
of this line and subsequent weather threats on Tuesday are
.LONG TERM... /Issued 355 PM CDT Mon Oct 8 2018/
/Tuesday through Monday/
Our slow moving upper trough to the west will finally be on the
move Tuesday spreading rain and thunderstorms across the region. A
fairly well organized line of thunderstorms should be ongoing
early Tuesday morning across west Texas as strong forcing for
ascent spreads across the Panhandle and into the Southern Plains.
This line of storms will likely be approaching our western
counties prior to sunrise. Latest runs of the high resolution
guidance continue to show a weakening trend through the early
morning as the line approaches the I-35 corridor. This makes sense
given that the upper trough will likely eject north-northeast,
taking the best upper jet dynamics and forcing for ascent with it.
In addition, the strongest portion of the low level jet will also
As we get into midday and the early afternoon, the upper trough
axis will spread into west Texas. Despite our being removed from
the best upper forcing, the system will remain quite dynamic
across our region and we should see a reinvigoration of convection
near the I-35 corridor as the atmosphere destabilizes. With deep
moisture (PWs of 1.8 to 2") remaining in place and an increase in
low level convergence expected in the uncapped environment, we
should see rapid development of new convection into the afternoon
and evening hours. The latest 3km NAM and HRRR are most aggressive
with this scenario and are also the slowest of the guidance. With
the upper trough moving almost due north initially, this would
keep deep meridional flow in place across North Texas, and would
suggest a slow eastward movement initially with any new
convection. This would also allow several hours of afternoon
destabilization to occur along and east of I-35. The upper trough
will eventually swing through late tomorrow evening allowing any
additional convection to spread eastward. The severe threat will
be dependent upon how much morning activity occurs and how late
the afternoon convection develops. If the latest trends in the
high res guidance continue then it appears we will become quite
unstable by tomorrow afternoon, especially across our eastern
counties. While lapse rates are marginal, the hail threat appears
pretty low, but damaging winds would certainly be possible with
the strongest storms. There will continue to be a conditional
tornado threat given the low LCL`s and instability, and would
certainly have to be monitored in areas where surface winds are
backed in the vicinity of any mesoscale boundaries. We`ll have
high PoPs across the entire area for tomorrow and will hang on to
them a little longer into the evening hours given the likelihood
that the entire system is a little slower to depart the area.
Concerning the flash flood potential...there will be a threat for
heavy rainfall with any of the storms from this evening through
Tuesday evening since we keep the near 2" PWs in place. Storm
motions will be fast given the strong deep layer southerly flow,
so despite rainfall rates of 1.5-2"/hr, they should not persist in
any one area for very long. The only exception may be with the
line of showers/storms during the early morning hours. We`ll have
to watch the organization of this overnight. If it appears that it
will make farther eastward progress than currently anticipated,
then we could have some issues over our western counties. We`ll
hold off on issuing any flash flood watches at this time.
Rainfall should end from west to east quickly Tuesday night with
Wednesday and Thursday being rather nice days. We`re still
monitoring the potential for the remnants of Sergio to interact
with a southward moving cold front later this week across the
Southern Plains. We`ll keep 20-40% PoPs in for the Saturday-Sunday
timeframe at this time with the best chances on Sunday. There may
be some potential for heavy rainfall with this system.
Temperatures behind this cold front will be much more fall like
with highs in the 60s on Sunday into early next week.
.PRELIMINARY POINT TEMPS/POPS...
Dallas-Ft. Worth 72 80 62 77 56 / 50 90 70 0 0
Waco 72 83 64 82 58 / 50 80 70 0 0
Paris 70 80 64 77 54 / 50 70 90 0 0
Denton 70 79 60 76 55 / 50 90 70 0 0
McKinney 70 79 61 76 54 / 50 90 80 0 0
Dallas 73 81 64 78 57 / 50 90 80 0 0
Terrell 72 85 65 81 57 / 50 80 90 0 0
Corsicana 72 82 64 79 57 / 40 80 80 0 0
Temple 72 83 64 82 59 / 60 80 70 0 0
Mineral Wells 69 79 56 76 53 / 60 90 30 0 0
Area Forecast Discussion
National Weather Service North Platte NE
632 PM CDT Mon Oct 8 2018
.SHORT TERM...(This evening through Tuesday)
Issued at 326 PM CDT Mon Oct 8 2018
Main forecast concern this period is precipitation for the rest of
today and overnight and precipitation chances on Tuesday along with
where the rain/snow line will set up. Drier air has moved in across
southwest Nebraska and the HRRR seems to be the best model to have a
handle on this so have trended towards the HRRR for precipitation
chances tonight. Decided to get rid of the likely rain chances
across southwest Nebraska keeping only chances in overnight as
rainfall across this area should take a break for the next 6 to 12
hours. That being said have also reduced rainfall amounts overnight.
Precipitation will stick around a little longer across north central
Nebraska. Areas of patchy fog will mostly likely develop overnight
towards morning, keeping visibilities low at times.
For Tuesday, the upper level low, currently situated over southwest
CONUS will continue to move northeastward across the High Plains
region. High temperatures will remain cold with highs hovering above
freezing across the northwest Sandhills. Bufkit soundings show cold
air both at the surface, through the mid layer into the dendritic
layer giving confidence that areas across the northwest Sandhills
will see wet snow. The forecast becomes trickier the farther east
and south just where the rain/snow line will set up. Current
thinking is the rain/snow line will slowly progress eastward during
the day but temperatures should remain just warm enough to keep most
areas across southwest and north central Nebraska all rain through
the day before changing over to a rain/snow mix in the evening. The
best area for snowfall on Tuesday will be across the Sandhills,
snowfall amounts will be light through the day.
.LONG TERM...(Tuesday night through Monday)
Issued at 326 PM CDT Mon Oct 8 2018
All of the 12z models, SREF and 18z NAM models have tightened up and
track a closed h700mb low through ncntl Nebraska Tuesday and Tuesday
night. This should position a rain snow line across wrn Nebraska
Tuesday afternoon which will move east Tuesday night. The
frontogenesis is fairly strong and about 0.33 to 0.75 inches of
liquid rain/snow is predicted by the models as this low lifts
through. Rain changing to snow should end by 12z Wednesday morning
with temperatures below freezing. The best guess on snowfall is 1 to
3 inches using snow ratios between 5 and 10 to 1.
Road temperatures are still in the upper 30s to lower 40s across
northwest Nebraska but another night of cooling could lower them
into the 30s and then below freezing Tuesday night. The potential
for icy roads Tuesday night appears high and a winter weather
advisory is in place for parts of wrn and ncntl Nebraska beginning
late Tuesday afternoon and ending Wednesday morning.
A second storm system will follow on the heals of the system Tuesday
affects wrn and ncntl Nebraska Thursday night. Todays model runs
split a large portion of this storm through the Rockies and as a
result, rain/snow chances across wrn and ncntl Nebraska are much
lower. Lastly, the remnants of "Sergio" could produce a mix of rain
and snow across srn Nebraska Saturday.
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 632 PM CDT Mon Oct 8 2018
Periods of rain and possibly snow will continue through the
forecast period, though the heaviest precipitation and greatest
chances for snow come after 15z Tuesday. Expect IFR or lower
through much of the period, with the potential of reduced
visibility when the precipitation occurs, especially true at the
KVTN terminal late Tuesday when a changeover to snow is expected.
Overall confidence is high do to strong model agreement, but
timing on the categorical changes is low, expect updates to the
forecast as we follow the trends.
Winter Weather Advisory from 4 PM CDT /3 PM MDT/ Tuesday to 9 AM
CDT /8 AM MDT/ Wednesday for NEZ004>006-008-022>025-035-036-094.
Area Forecast Discussion...UPDATE
National Weather Service Portland OR
851 PM PDT Mon Oct 8 2018
Updated Aviation section.
.SYNOPSIS...Cloudy skies and period of rain and drizzle will continue
across the region through Tuesday as a weak disturbance moves across
the forecast area. Some showers continue late Tuesday, but begin to
decrease after a cold front pushes south through
the forecast area. Drier and milder weather will come later in the
week as an upper level ridge of high pressure builds across the
.SHORT TERM...Tonight through Thursday...Another impulse crossing the
region today is maintaining abundant low clouds and light rain or
drizzle across much of the forecast area. While any particular hourly
total has been rather light, the persistent nature of this rain is
adding up with anywhere from one to three tenths of an inch across
many locations in the Willamette Valley, and locally higher totals
along the coast and in the terrain of the Coast Range and Cascades
where up to three-quarters of an inch have been measured in the last
24 hours. Not much change in the pattern of rain and clouds is
expected for the next day or so. The strong shortwave moving through
the Gulf of Alaska as it rounds the strong upper level ridge over the
eastern Pacific will drop southeast across Washington and Oregon on
Tuesday. Forecast models remain rather consistent with this feature,
so have maintained the relatively high PoPs as this impulse moves
through the region for one last organized round of rain this week.
Behind this disturbance, some showers will linger but these showers
will then becoming confined to the higher terrain of the Cascades by
Tuesday night. Dewpoints will remain rather high and the rather moist
lower levels of the atmosphere will keep low clouds and areas in fog
in place both tonight and tomorrow night. This widespread cloud cover
will also serve to keep temperatures a few degrees or more below
seasonal normals for the next couple of days.
Lingering low-level moisture into Wednesday should maintain some
morning clouds, but a drying north to northeast flow should develop
to begin to bring a return of clearing skies by Wednesday afternoon.
This will likely result in a chilly and clear Wednesday night into
Thursday morning, outside of patchy fog developing in portions of the
valley. Thursday`s temperatures will trend to near seasonal normals
with afternoon sun after the morning fog as high pressure strengthens
over the region.Cullen
.LONG TERM...Thursday night through Monday...The 12z GFS and 12z
ECWMF are still in good agreement through the extended forecast
period. A massive upper level ridge will be the dominating feature,
as the weekend approaches the ridge axis looks to tilt slightly
positive. As a result the surface high over the Columbia River
basin, which in turn will cause a tightening of the surface pressure
gradient leading towards an offshore flow pattern. This could lead
to the most significant east winds so far this season, with gusts up
to 35 to 45 mph near and in the western Gorge. Look for these gusts
from late this week into the weekend. Overall during this time
period the area will stay dry, along with temperatures around
seasonal to slightly warmer than seasonal. Highs in the upper 60s to
lower 70s, and lows in the mid to upper 40s. /42
.AVIATION...Overall inland areas have seen the most improvement
this evening with mainly VFR conditions south of KPDX. KPDX
northward continues with MVFR to IFR cigs, and LIFR at the coast.
Latest HRRR model show another impulse moving in from the
northwest that may clip areas north of KSLE with lowering
conditions overnight so could see low MVFR or IFR cigs return for
a few hours. But after 12Z or so cooler air aloft should help mix
the lower layers to improve to high end MVFR or VFR during the
day Tuesday. Coastal areas likely to remain IFR or worse through
midday Tuesday, perhaps longer. But forecast sounding do show a
improving trend with cigs slowly lifting in the afternoon.
Light offshore flow develops Tuesday night into Wednesday so
expect a mix of IFR fog and stratus late Tuesday night.
KPDX AND APPROACHES...Low end VFR to MVFR cigs in the immediate
area of KPDX but IFR cigs not far away. HRRR model shows
increasing chance of rain after 09Z Tues and satellite & radar
show this feature. Based on that do think lower conditions are
possible for several hours, the gradually improving as cooler air
aloft arrives. /mh
.MARINE...Weak fronts will move across the waters through the
first half of the week. The next one will bring advisory winds as
well as increasing NW swell, enough that we`ve issued a Small
Craft Advisory for Hazardous Seas in addition to the Small Craft
Advisory for Winds which was issues this morning. Wind gust
strength will be marginal south of Cascade Head, so haven`t
issued anything for winds there. Models have been steadily
increasing the seas forecast with the incoming swell, so while
the current forecast is for a peak of 11-12 ft for the waters
within 10 nm of the coast, they could end up even a foot or two
higher than that.
High pressure will build over the waters starting Wednesday
afternoon, bringing the return of a summer-like northerly wind
pattern for a few days. Seas will decrease during this period,
staying around 5 to 6 ft Wednesday night through at least
PZ...Small Craft Advisory for winds until 7 PM PDT Tuesday for
Waters from Cape Shoalwater WA to Cascade Head OR from 10
to 60 NM.
Small Craft Advisory for hazardous seas from 5 AM Tuesday to 5
AM PDT Wednesday for Coastal Waters from Cape Shoalwater
WA to Cascade Head OR out 60 NM.Waters from Cascade Head
to Florence OR from 10 to 60 NM.
Small Craft Advisory for winds from 5 AM to 2 PM PDT Tuesday
for Coastal waters from Cape Shoalwater WA to Cascade Head
OR out 10 NM.
Small Craft Advisory for hazardous seas from 2 PM Tuesday to 5
AM PDT Wednesday for Coastal waters from Cascade Head to
Florence OR out 10 NM.
Small Craft Advisory for Rough Columbia River Bar from 2 AM to
7 AM PDT Tuesday.
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This discussion is for Northwest Oregon and Southwest Washington
from the Cascade crest to 60 nautical miles offshore. This area is
commonly referred to as the CWA or forecast area.
Area Forecast Discussion
National Weather Service Blacksburg VA
1033 PM EDT Mon Oct 8 2018
A warm and moist southeast flow will continue over the region
through midweek as high pressure begins to shift off the coast. This
will lead to more clouds than sun with overnight areas of fog, with
temperatures remaining above-normal for early October. Hurricane
Michael is expected to move out of the Gulf of Mexico through the
southeastern US by mid to late in the week. Impacts, if any, from
Michael remain uncertain.
.NEAR TERM /THROUGH TUESDAY/...
As of 1030 PM EDT Monday...
Radar showed squattered showers from Grayson County Virginia
into the northwest North Carolina mountains. HRRR and Hi-Resarw
maintained at least isolated showers in that area through
00Z RNK sounding showed moisture through the lowest 3000 feet of
the atmosphere with southeast winds extending up to about
10,000ft. With that upslope expect clouds to continue to
develop. Models showed widespread cloud cover by 06Z/2AM across
much of the Blue Ridge and foothills. Similar to past few
nights, fog will fill in the valleys, especially where it takes
longer for clouds to form. Only minor changes made to overnight
For Tuesday, there`s a good deal of uncertainty timing when low
clouds and interspersed foggy areas from the overnight can thin out.
Similar to today, will likely see continued overcast through a good
part of the morning based on BUFKIT soundings, with breaks in the
cloudiness becoming more apparent by the afternoon. Western extent
of the wedge begins to weaken and will start to tap into the
subtropical feed of moisture now across the SC/GA coast. This should
help to encourage a greater coverage of showers tomorrow from along
and east of the Blue Ridge during the afternoon hours. Though
forecast CAPE values would support a threat of thunder, there is
still a considerable amount of dry air aloft that will likely lead
to shallow convective growth Tuesday. As such, think showers should
again predominantly be the case versus thunder.
For high temperatures, started with continuity but utilized
more of the cooler raw guidance to lower temperatures a couple
degrees to readings in the lower to mid 70s generally,
approaching 80 in Southside and the northern NC Piedmont. If
cloud cover should prove to be more stubborn, this could still
be too warm by a few degrees.
Confidence is moderate tonight, but is low to moderate for
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/...
AS OF 345 AM EDT Monday...
Large scale flow pattern features highly amplified and active
longwave trough over the Rockies with Bermuda High over the
western Atlantic. This pattern is forecast to deamplify by the
end of the week as Hurricane Michael gets a sling shot across
the southeast states per interaction with the western long wave
trough. Net result for our forecast area will be a wholesale
increase in the rain threat from Wednesday into Thursday per
deep southeast fetch of Atlantic moisture Wednesday, followed by
left quadrant swipe of tropical moisture from the remnants of
Michael on Thursday. Model consensus has the center of Michael
passing across the Carolinas during the day Thursday with the
axis of the heaviest rain passing to our southeast. That said,
48 hour rain totals (WED-THU) for our CWA are still expected to
be respectable, with amounts in the 1 to 3 inch range.
As the tropical system gains latitude late Thursday, surface
front from the western trof is expected to pass through the
forecast area Thursday night. This will begin a period of drying
as it shunts the deeper tropical airmass off the east coast.
Dewpoints just behind the front are progged in the 40s, so it
will be a noticeable airmass change.
.LONG TERM /FRIDAY THROUGH MONDAY/...
As of 400 PM EDT Monday...
Upper level pattern will deflate over the weekend and into the
following week as the Bermuda high gives up the October ghost.
One last surge of higher dewpoint air will try to work back into
the area Sunday ahead of what will be the remnants of Hurricane
Sergio which is expected to get drawn into the southwestern U.S
Saturday and into the base of the central CONUS long wave
trough. Attm it appears the energy associated with this feature
will pass through the OH valley Sunday with showers primarily
to our northwest. However, with the passage of this feature it
will open the door for a pattern change with the northern jet
stream making dive into the central and eastern CONUS, a feature
that will favor below normal temperatures across much of the
central and eastern U.S. by the middle of next week.
As for the details, the upcoming weekend as a whole does not
look that bad...featuring dry conditions and near seasonal
temperatures. Near seasonal temperatures however, means
temperatures at night will be in the 40s, so it will feel
noticeably cooler compared to our extended summer-like nights.
By Monday, showers associated with the deepening upper level
trough to our northwest are expected to move across the area.
After that...it dries out for the middle of next week, but the
bottom drops out of the thermometer. Will there be frost for
Wednesday or Thursday mornings of the 17/18th? Time will tell.
.AVIATION /03Z TUESDAY THROUGH SATURDAY/...
As of 755 PM EDT Monday...
Scattered VFR/MVFR ceilings in the 2000-4000 agl range across
southwest Virginia, southeast West Virginia and northwest North
Carolina this evening.
IFR ceilings and MVFR fog will fill in across much of the region
overnight with guidance showing high relative humidity below
850MB from 06Z/2AM through mid morning. Low Level winds increase
from the southeast tonight and the resulting upslope will
result in areas of MVFR drizzle and light rain, especially along
the Blue Ridge and over the foothills of Virginia and North
Carolina. Some river valleys west of the Blue Ridge may have
LIFR fog, including at KLWB and possibly at KBCB. Ceilings will
gradually lift Tuesday afternoon with isolated to scattered
Confidence is above average tonight and below average on timing
of returning to VFR Tuesday afternoon.
Showers are expected to increase in coverage by Wednesday and
Thursday as tropical moisture shifts northward ahead of
Hurricane Michael and a cold front moving in from the west.
Rain may be heavy at times Thursday. Conditions will improve
back to VFR on Friday behind the front, then VFR over the
Area Forecast Discussion
National Weather Service San Angelo TX
649 PM CDT Mon Oct 8 2018
Look for Challenging flight weather to dominate West Central Texas
tonight and much of tomorrow. As an upper disturbance moves east,
across Texas, watch for a line of thunderstorms to sweep, from
west to east, across West Central Texas. The HRRR brings this line
into West Central Texas, from the west, around 06Z tonight. By
tomorrow afternoon, this line should be exiting West Central
Texas, and conditions should return to VFR.
.PREV DISCUSSION... /issued 614 PM CDT Mon Oct 8 2018/
Just sent a forecast update for a Severe Thunderstorm Watch for
some of our central and western counties through 1:00 AM CDT
PREV DISCUSSION... /issued 250 PM CDT Mon Oct 8 2018/
(Tonight and Tuesday)
Radar this afternoon shows scattered showers and thunderstorms over
Crockett County and the Concho Valley, while an area of light rain
was occurring over the Heartland and Northwest Hill Country. Hi-res
models indicate that this evening will not be too active with
showers and storms, but considering that they have not caught on to
the activity already occurring in the Concho Valley, would not be
surprised if we continue to see scattered convection through the
evening hours in the western half of the forecast area, and so the
PoPs this evening reflect that possibility. Models remain in very
good agreement with a large line of thunderstorms and showers moving
through the region from west to east late tonight through early
Tuesday afternoon as a front gets pushed through. The additional
heavy rainfall associated with this activity will result in a higher
threat of flash flooding, so the Flash Flood Watch continues through
7 am Tuesday for the Big Country, Concho Valley, Northern Edwards
Plateau and Kimble and Menard counties. There`s also a threat for
flash flooding through Tuesday afternoon for the Heartland counties
and Mason county, so the Flash Flood Watch was expanded into those
areas. In addition, there is a threat for severe thunderstorms today
and tonight with any storms that develop... then a higher threat for
strong to severe storms will occur as that aforementioned line of
storms moves through late tonight into Tuesday morning. CAPE values
of 1000-1500 J/KG and 0-6 km bulk shear 40-50 kt support rotating
updrafts, and 0-1 km bulk shear of 30 kt shown by the NAM12 model
indicates the potential for a few embedded tornadoes within the line
of storms. Thunderstorm/shower activity should diminish from west to
east across the Tuesday morning and afternoon, with mostly dry
conditions likely by late Tuesday afternoon.
(Wednesday through Monday)
The upper trough moves off to the east of the region Tuesday night
with drier air filtering into West Central Texas on Wednesday.
Expect mostly sunny skies on Wednesday and Thursday. PoP`s
re-enter the forecast for the latter half of the week as another
upper level low deepens across the southwest U.S. There remains
model disagreement as to the timing of disturbances in the
southwest flow aloft and the evolution of the upper low...thus
will keep PoP`s in the 20-40 percent range from Thursday through
the end of the week. Also, a strong cold front may dive southward
into west Texas by next weekend.
.PRELIMINARY POINT TEMPS/POPS...
Abilene 65 77 53 73 / 90 80 10 0
San Angelo 65 79 55 78 / 90 80 10 0
Junction 69 80 57 81 / 80 90 20 0
Brownwood 67 77 56 76 / 70 90 20 0
Sweetwater 63 75 52 73 / 90 70 10 0
Ozona 65 77 54 78 / 90 70 10 0
Flash Flood Watch through Tuesday morning for Callahan-Coke-
Flash Flood Watch through Tuesday afternoon for Brown-Coleman-