Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 10/07/17
Area Forecast Discussion
National Weather Service Albuquerque NM
602 PM MDT Fri Oct 6 2017
.AVIATION...
18Z TAF CYCLE
Isolated showers and thunderstorms are expected to linger across
southeast areas until mid evening. Mesoscale models show this
convection staying north of ROW. Meanwhile, a Pacific cold front
will also finish crossing eastern areas from the northwest by mid to
late evening. The pressure gradient with the front will enable gusty
winds to persist a few hours after dark this evening, especially east
of the Rio Grande. Lighter winds are expected with dry weather on
Saturday.
44
&&
.PREV DISCUSSION...304 PM MDT Fri Oct 6 2017...
.SYNOPSIS...
Much drier air is racing eastward across NM today on breezy west
winds. The strongest winds will focus over the high plains of
eastern NM then taper off after sunset. Remnant moisture along the
Texas state line will still allow for a showers and storms to fire
up into this evening. A few storms may become strong to severe. The
weather over the weekend will be very nice with mild temperatures,
lighter winds, and much cooler overnight temperatures. Many areas
will see their coldest readings so far this fall season. The next
storm system will approach New Mexico from Colorado on Monday and
bring more fall like weather to the state. The first noteable
snowfall is possible for the Sangre de Cristo Mountains through
Tuesday morning. Much colder air will invade the state behind this
system. Milder and more tranquil weather is expected Wednesday and
Thursday.
&&
.DISCUSSION...
Impressive changes have developed today as dramatically drier air
shifts east across NM. Surface dewpoint have fallen from the 50s and
60s early this morning into the single digits and teens. This much
drier air along with decoupling overnight will lead to the coldest
overnight lows of the season so far for much of the state.
But first, abundant moisture still in place over far eastern NM
along with strong afternoon heating and instability will lead to a
few strong to severe storms thru early this evening. The SPC storm
outlook still shows a marginal risk along the TX state line with a
slight risk just across the bow. Latest radar trends are in line
with where the HRRR shows storms firing up today. Left some chance
PoPs thru early tonight across the high plains and Caprock area.
The weekend looks absolutely gorgeous with dry air, clear skies, and
overall light winds across NM. Afternoon temps will be mild while
overnight lows fall to near seasonal normals. This will of course
feel chilly after our recent warm and moist stretch. Inversions will
favor northern and western valleys each night where lows in the 20s
and 30s will be common.
The first real cool season storm system will approach NM from CO on
Monday and increase the potential for accumulating snowfall in the
Sangre de Cristo Mts Monday thru Tuesday morning. Guidance shows an
approximate 558dm H5 upper low developing southward into the Four
Corners region while a potent back door front enters eastern NM on
Monday. This front will surge west thru the central mt chain and
bring gap winds into the ABQ area Monday night and Tuesday morning.
Meanwhile, strong 700mb cold advection will focus over the northern
mts where readings fall to near -6C. This will be plenty cold enough
for snow, however, the focus area for accumulations will be brief. At
this time a quick 2 to 5" is entirely possible. Elsewhere, skies
will remain mainly clear with breezy to windy conditions within the
base of the upper low.
Mild daytime temps will return Wednesday and Thursday as upper flow
becomes more west/southwest. Overnight lows will still be rather
chilly for valley locations. A slow moistening trend is expected as
we approach the end of next week.
Guyer
&&
.FIRE WEATHER...
Significant drying underway as a Pacific cold front races east
across the state. The latest 24hr surface dewpoint temperature
change values are running -30 to -45 across central and western
portions of the area, indicating a change of atmosphere. Several
central and western sites are currently hitting critical threshold
for wind and humidity, but moist soil conditions from recent rains
and only moderate Haines values are not supportive of large fire
growth. Drying will continue across the Eastern Plains this evening
and overnight. Cooler and drier conditions with much lighter winds
will prevail Saturday in the wake of the Pacific front. A lee side
trough will deepen Sunday in response to an approaching upper level
trough/low, with winds and daytime temperatures trending up some. By
Sunday afternoon, highs are forecast to be above normal almost
areawide.
An upper level trough/low and associated cold front will impact our
area Monday. Although there is some model disagreement on the track
of the upper low, the latest solutions agree on chances for wetting
precipitation ramping up across northern New Mexico late Monday into
Monday night. Several inches of snow are possible, mainly in the
Northern Mountains and nearby Highlands. Much colder conditions will
follow behind the front going into Tuesday, with temperatures
forecast below normal.
Relatively moist conditions will prevail from mid to late next week
as moisture comes back, with the upper high parked to the east and
an upper level trough making slow eastward progress across the
Intermountain West. The timing of the moisture advection is a lower
confidence forecast given some differences between the latest ECMWF
and GFS, but should begin sometime Wednesday or Thursday. Chances
for wetting rain will ramp up again during this period, with the
best chances across the East Central and Southeast Plains.
11
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
Area Forecast Discussion
National Weather Service Albany NY
1028 PM EDT Fri Oct 6 2017
.SYNOPSIS...
Fair weather expected through this evening hours. A stalled
front across the region will move north as a warm front
overnight into Saturday ushering a warmer airmass into the
region. There are good chances for showers Sunday as a
disturbance and cold front move across the region. A widespread
rainfall is expected Monday and Monday night as the remnant low
from the once tropical cyclone Nate interacts with front across
the region.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
As of 1028 PM EDT...A stationary frontal boundary continues to
be draped across the western and central New York and extending
eastward across the Catskills and mid-Hudson Valley and into NW
CT. IR satellite imagery shows plenty of cloud cover associated
with boundary, although observations and radar imagery is not
showing much precip falling from these clouds aside from a few
light sprinkles over the eastern Catskills and mid-Hudson
Valley.
Through the overnight hours, the stationary front will start to
lift northward as a warm front, as a deepening storm over the
Great Plains lifts towards the Upper Midwest and western Great
Lakes. The 3km HRRR suggests most of the night is dry, although
some showers could reach into the western Mohawk Valley and
western Adirondacks towards daybreak as the front lifts
northward. As a result, most of the overnight will remain quiet
with overcast skies.
Due to the cloud cover tonight will be a mild night with lows
mainly in the 50s; about 10 degrees above normal.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/...
As the warm front lifts north as warmer airmass will be ushered
in for the weekend with temperatures 15 to 20 degrees above. The
southerly flow that develops will also usher more humid air
into the region with dew points rising into the 60s across much
of the area.
Any threat of showers associated with the warm front is expected
to be limited to the far northwest portion of the forecast area
Saturday morning. Otherwise fair weather is expected with
decreasing cloud cover with temperatures topping out mainly in
the 70s with some 60s above 2000 feet.
A potent short wave and cold front will be on the approach late
Saturday night into Sunday and will be good chances for showers
to the area along with the possibility for a few thunderstorms
as the warm and humid airmass destabilizes. A strong 850 mb jet
jet will accompany this feature as it quickly moves through.
However the front is expected to become stalled across the
region in the deep southwesterly. Southerly winds will become
breezy Sunday with gusts up to 25 to 30 mph.
Tropical Cyclone Nate will continue weaken as it moves across
the southeastern United States Sunday and is expected to weaken
at a depression by Monday morning. Refer to the National Hurricane
Center for the official forecast on Nate. What is left of Nate
will interact with the stalled boundary across the area and
bring a widespread rainfall to the region. There are still
uncertainties in the forecast but at this it 1 to 2 inches of
rainfall is expected developing late Sunday night/early Monday
morning into Monday night. Due to antecedent dry conditions,
flooding is not anticipated at this time. This would be the
first widespread rainfall since early September when moisture
from Tropical Cyclone Jose impacted the region. It will cooler
but since humid with above normal temperatures Monday with highs
from the mid 60s to lower 70s.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
At the start of the long term period, the remnant low from what was
once TC Nate will be moving across the northern mid-Atlantic States,
the NYC metro area and into southern New England for Monday night
into Tuesday morning. The remnant low will be post-tropical by this
point and won`t have any strong winds associated with it. However,
the surge of tropical moisture into the region will allow PWAT
values to remain elevated on Monday evening, with values around 2.00
to 2.25 inches across our area, which is about 2 to 4 STD above
normal for this time of year. These values should be lowering by
Tuesday morning, as the deepest moisture shifts east of the region,
as the low departs away.
As a result, we can continue to expect some showers on Monday night,
although the coverage will likely be starting to lower by Tuesday
morning. With the high PWATs and high FZL level (around 15 kft),
warm rain processes will dominate and any showers will continue to
be capable of producing locally heavy downpours. It should be
cloudy and muggy for all of Monday night and lows will only fall
into the upper 50s to mid 60s, which is well-above normal for this
time of year.
The chance for rain will decrease through the day on Tuesday and
some breaks of sun should return by the afternoon hours. It will
continue to be mild, with highs reaching into the 70s in most
locations, as upper level heights remain rather high behind the
departing remnant low.
High pressure will be building into the area for the middle to
latter part of the week from southern Canada. At the same, a weak
shortwave will be rounding the top half of the upper level ridge,
but looks to be weakening. We cannot totally rule out a brief
shower at some point Wednesday into Thursday with this feature, but
most areas look to remain dry, with a partly to mostly cloudy sky.
However, this shortwave may help dampen the ridge somewhat and allow
temps aloft to cool off somewhat, so temps should return closer to
normal values by later in the week. Although highs on Wednesday will
likely still be above normal in the mid to upper 60s for most valley
areas), they should be lowering towards the lower to middle 60s for
Thursday and Friday. Overnight lows look to be in the 40s for most
locations.
&&
.AVIATION /03Z SATURDAY THROUGH WEDNESDAY/...
IR satellite imagery and surface observations shows bkn-ovc cigs
around 5 kft thanks to a stationary boundary draped across the
region. This front will slowly lift northward as a warm front
for the overnight hours and into the day on Saturday. Model
soundings suggest skies skies will remain bkn-ovc through at
least midday Saturday, although ceilings heights should remain
VFR. Any showers with this boundary should remain west of the
region. Light to calm winds are expected overnight into Saturday
morning. With the clouds in place, no radiational fog is
expected to form.
By Saturday afternoon, the warm front will be north of the area,
and sky cover will start to improve. Ceilings will continue to
rise and start to become sct in coverage, especially by late in
the day. VFR conditions will continue and winds will pick up
from a southerly direction at 5-10 kts.
Outlook...
Saturday Night: Moderate Operational Impact. Chance of SHRA.
Sunday: Moderate Operational Impact. Breezy Chance of SHRA...TSRA.
Sunday Night: Moderate Operational Impact. Chance of SHRA.
Columbus Day: High Operational Impact. Likely SHRA.
Monday Night: High Operational Impact. Likely SHRA.
Tuesday: Moderate Operational Impact. Chance of SHRA.
Tuesday Night: Low Operational Impact. Slight Chance of SHRA.
Wednesday: Low Operational Impact. Slight Chance of SHRA.
&&
.FIRE WEATHER...
Fair weather expected through this evening hours. A stalled
front across the region will move north as a warm front
overnight into Saturday ushering a warmer airmass into the
region. There are good chances for showers Sunday as a
disturbance and cold front move across the region. A widespread
rainfall is expected Monday and Monday night as the remnant low
from the once tropical cyclone Nate interacts with front across
the region.
It will become breezy on Sunday with s winds from the south to
southwest at 10 to 15 mph with gusts up to 25 mph.
&&
.HYDROLOGY...
Fair weather expected through this evening hours. A stalled
front across the region will move north as a warm front
overnight into Saturday ushering a warmer airmass into the
region. There are good chances for showers Sunday as a
disturbance and cold front move across the region.
A widespread rainfall is expected Monday and Monday night as
the remnant low from the once tropical cyclone Nate interacts
with front across the region. One to 2 inches of rainfall is
expected at this time with locally up to around 3 inches possible.
Due to antecedent dry conditions, flooding is not anticipated
at this time. This would be the first widespread rainfall since
early September when moisture from Tropical Cyclone Jose
impacted the region.
For details on specific area rivers and lakes, including observed
and forecast river stages and lake elevations, please visit the
Advanced Hydrologic Prediction Service /AHPS/ graphs on our
website.
&&
.CLIMATE...
Record highs for Sunday October 8th
Albany NY: 79 degrees 2011
Glens Falls NY:77 degrees 1993
Poughkeepsie NY: 89 degrees 2007
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
MA...None.
VT...None.
&&
$$
SYNOPSIS...IAA
NEAR TERM...IAA/Frugis
SHORT TERM...IAA
LONG TERM...Frugis
AVIATION...Frugis
FIRE WEATHER...IAA
HYDROLOGY...IAA
CLIMATE...
Area Forecast Discussion
National Weather Service Des Moines IA
647 PM CDT Fri Oct 6 2017
.SHORT TERM.../Tonight through Saturday/
Issued at 352 PM CDT Fri Oct 6 2017
Concerns for tonight remain focused on the heavy rain potential
over much of the forecast area. There is a brief window for severe
weather late this afternoon into the early evening over the west
to southwest portions of the CWA. Leaned closer to the HRRR/ESRL
HRRR for convective trends and location this afternoon and tonight
as they seem to have a good handle on current radar trends.
NAM12/GFS/ECMWF even have a decent handle on pops and timing of
cold front overnight into Saturday morning.
Surface front, evident on visible satellite and surface obs (as of
20z), has stalled between Atlantic and Audubon and extends north-
northeast through north of Perry and Webster City then eastward
across the northeast portion of the forecast area. This will be the
location of severe weather potential this afternoon and the heavy
rain threat through the overnight hours.
Severe weather potential this afternoon and evening over the
southwest will be in the vicinity of the front. As of 20z, MLCAPE
values have increased over 500 J/kg with effective helicity and 0-
1km helicity around 300m2/s2 and 150m2/s2 respectively. Creston
forecast sounding per HRRR and RAP suggest even higher helicity
amounts this afternoon and the concern for a brief window of a
tornadic threat has increased. Even the Significant Tornado
Parameter (effective layer) has increased to 0.5 this afternoon.
Any clearing in the southwest should help erode any cap and
increase the surface based instability. Current satellite trends
suggest the cloud cover to remain over southwest Iowa for now, even
though some clearing creeping into northwest Missouri. By sunset or
shortly after, much of the convection will likely turn to more to
the heavy rain threat. For a detailed discussion on the heavy rain
potential, see the hydrology section below.
.LONG TERM.../Saturday night through Friday/
Issued at 352 PM CDT Fri Oct 6 2017
The weather through this period will start off more uneventful
with only one potential precip window of significance. Overall
there will be little change in the long wave pattern with varied
degrees of a western CONUS trough and eastern ridge with Iowa in
persistent southwest flow aloft in between. The weekend will
start with fair weather but several short waves which will drive
a weak cold front through late Sunday. They will be moisture
starved however so while the forcing will be moderate it will
struggle to generate much if any precipitation.
The upstream long wave trough will mature into early next week
however and eventually develop a full blown cool season cyclone
with strong deformation zone forcing through Iowa or northern MO
depending on the track. Both the 12z GFS and ECMWF depict strong
theta-e advection and frontogenetic response through the def zone
in impressive baroclinicity. There have been recent timing issues
but runs are now focusing more on Monday Night into Tuesday so if
these trends continue fully expect PoPs to increase during this
time frame, especially for southern Iowa. With Iowa being in the
cool sector, instability is fairly weak with little to no severe
potential. There may be some potential for at least moderate rains
however as all liquid deformation zones often produce. There
should be sharp subsidence behind this system as it moves away
with the aforementioned model agreement beginning to favor frost
potential far north, especially northwest. Persistent SW flow to
end the work week will eventually develop strengthening
warm/theta-e advection with an associated surface warm front in or
somewhere Iowa. Thus have started patchy low chances for showers
Thu Night into Fri.
&&
.AVIATION.../For the 00Z TAFS through 00Z Saturday evening/
Issued at 645 PM CDT Fri Oct 6 2017
Areas of convection will continue through 12z with occasional IFR
cigs/vsby. Main corridor of activity will be centered on
KDSM/KFOD/KMCW/KALO with bulk of worst avn conditions through 06z
in these areas then a large shield of rain/embedded sct convection
will overspread the region through 12z...tapering off east of I35
by 18z. Overall expect poor conditions to remain with IFR/MVFR
occasionally lowering to LIFR in heavier precipitation bands.
Confidence on timing of bands low...but increase in coverage aft
06z higher confidence. Will update as needed through period. /rev
&&
.HYDROLOGY...
Issued at 352 PM CDT Fri Oct 6 2017
Deep moisture convergence along the front in southwest
Iowa continues to increase and some elevated convection has begun to
develop in this location. Unprecedented October dew points south of
the front in the upper 60s to lower 70s with PWAT values in the 1.5
to near 2.0 inches...which are well above normal for this time of
year. Warm layer cloud depths in the 3500-4000 meter range this
evening with good moisture transport into the state to continue feed
the convection tonight. Rainfall rates likely to range from 2 to 4
inches per hours at times and Corfidi vectors parallel with the
storm motion tonight, so training is certainly a potential.
Confident in the widespread heavy rain of 1 to 2 inches with several
locations in the current watch location to see over 3 to 5 inches
possible.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
Flash Flood Watch through Saturday morning for IAZ033>036-
044>048-057>060-070>073-081>083-092>094.
&&
$$
SHORT TERM...Podrazik
LONG TERM...Small
AVIATION...REV
HYDROLOGY...Podrazik
Area Forecast Discussion
National Weather Service Austin/San Antonio TX
741 PM CDT Fri Oct 6 2017
.AVIATION... /00Z TAFS/
Vfr skies should hold up for most of the night. The surface pressure
gradient should remain light in advance of an approaching weak front.
Low clouds forming in the overnight hours over the Hill Country may
have trouble expanding out into the I-35 terminals, but have added a
mvfr cig at SAT based on the WRF low cloud simulated at 10Z. Post
daybreak cloudiness should be partly in the borderline ifr/mvfr level
and mostly in the 3000-5000 ft layer based on model time sections.
Mixing to vfr cigs is forecast by late afternoon over most areas as
the front becomes diffuse and replaced by a general light northeast
flow on the far western periphery of Northward moving Tropical Storm
Nate. Slightly better frontal zone convergence is forecast for DRT,
and a few light and generally insignificant showers could form over
the western counties. Low vfr level cigs are forecast to continue
into the late periods of the TAFs, but confidence is poor on whether
some of these will hold together at the mvfr level. Currently only
the SAT terminal forecast shows a persistent mvfr cig and will take
a closer look in the 06Z update.
&&
.PREV DISCUSSION... /ISSUED 320 PM CDT Fri Oct 6 2017/
SHORT TERM (Tonight through Saturday Night)...
The main concern in the short term portion of the forecast will be
monitoring the potential for isolated convection across portions of
the Rio Grande plains and southern Edwards Plateau this evening. Some
cu development is noted over the lower Trans Pecos region as of mid-
afternoon. The latest HRRR does capture this activity, but weakens
any convection that manages to sustain itself while moving eastward.
The Texas Tech WRF also shows a similar scenario, but is roughly 3 to
4 hours too slow in developing this convection. Given low confidence
in convection reaching western Val Verde county, we will not mention
in the forecast. Otherwise, look for another mild night with
overnight lows in the mid 60s to lower 70s. For Saturday, a weak cold
front should manage to drift slowly southward into the southern
Edwards Plateau and western Hill Country late Saturday afternoon into
the evening. The models do show some low potential for convection to
develop along this front. At this time, with weak forcing along the
front, we prefer to keep the forecast dry. The leading edge of this
front may drift close to the I-35 corridor, but should not have a big
impact on our weather. We did opt to lower some overnight lows
Saturday night behind the front as some drier along with clear skies
and light winds should drop some lows into the upper 50s to near 60
in the Hill Country.
LONG TERM (Sunday through Friday)...
Southerly flow and a warming trend are expected across all areas on
Sunday and Monday, with the warmest temperatures of the forecast
period expected on Monday. Based on recent trends in the GFS and
ECMWF MOS guidance, we have increased high temperatures on Monday.
This should result in highs in the 90s across most areas. Relief from
the heat is still expected either late Monday night or early Tuesday
as a strong cold front moves into the region. The ECMWF continues to
trend faster than the GFS and Canadian solutions. Given the
consistency in the ECMWF, we will continue to trend closer to this
solution. Some showers and storms are possible Monday night into
Tuesday as the front moves through. With the front likely remaining
the only source of lift, we will keep rain chances fairly low
(20-40%). Rain chances will end quickly behind the front as drier air
in the low-levels moves in from the north. Below normal temperatures
are expected Tuesday and Wednesday, followed by a slow warming trend
for late in the upcoming work week.
&&
.PRELIMINARY POINT TEMPS/POPS...
Austin Camp Mabry 68 88 68 91 71 / 0 - - 0 0
Austin Bergstrom Intl Airport 66 88 66 91 68 / 0 - - 0 0
New Braunfels Muni Airport 66 88 67 91 69 / 0 - - 0 0
Burnet Muni Airport 68 85 64 89 67 / 0 10 - 0 0
Del Rio Intl Airport 71 87 68 92 71 / 10 10 0 0 0
Georgetown Muni Airport 67 86 65 90 69 / 0 - 0 0 0
Hondo Muni Airport 69 87 67 93 70 / 0 10 0 0 0
San Marcos Muni Airport 66 88 66 90 69 / 0 - - 0 0
La Grange - Fayette Regional 66 89 70 91 70 / 0 - - - 0
San Antonio Intl Airport 69 88 68 91 71 / 0 - - 0 0
Stinson Muni Airport 69 88 70 92 71 / 0 - - 0 0
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
Mesoscale/Aviation...Oaks
Synoptic/Grids...05
Public Service/Data Collection...Treadway
Area Forecast Discussion
National Weather Service Indianapolis IN
1100 PM EDT Fri Oct 6 2017
.UPDATE...
The AVIATION Section has been updated below.
&&
.SYNOPSIS...
Issued at 153 PM EDT Fri Oct 6 2017
An upper level weather disturbance will exit Indiana late this
afternoon and early this evening. This will bring chances for
showers to an end across Central Indiana. Dry and warm weather is
expected for the first half of Saturday...as southerly flow is
expected ahead of a cold front.
The cold front will sweep across Central Indiana during the late
afternoon and evening hours...bringing chances for rain showers
and perhaps a thunderstorm across the state.
Dry weather is then expected to arrive late Saturday night and
continue through Sunday afternoon in the wake of the front.
Remnants from Tropical Storm Nate are expected to sweep into
Eastern Kentucky on late Sunday afternoon into Monday. This may
bring some rain chances to southeast parts of Central Indiana.
More rain chances are possible on Tuesday as a warm front lifts
into the area. Above normal temperatures are expected for much of
the next seven days.
&&
.NEAR TERM /Rest of Tonight/...
Issued at 936 PM EDT Fri Oct 6 2017
Brought small chance showers a bit further south to just north of
Bloomington through 04z, based on radar and obs. Then, ther
overnight should be dry.
Previous discussion follows...
Issued at 153 PM EDT Fri Oct 6 2017
Surface analysis early this afternoon shows a warm front across
northern Indiana. GOES 16 shows a stream of cloud and moisture
stretching along the front from Missouri across Illinois and
Indiana. Radar shows a cluster of showers mainly across the
northern half of the forecast area...quickly moving east within
the flow aloft.
Models suggest the short wave currently responsible for the
showers across the area will drift east and exit Central Indiana
Late this afternoon. However Water vapor continues to show a
tropical plume of moisture streaming into Illinois and Indiana.
Forecast soundings reflect this idea well..showing drying the mid
and lower levels through the night...but keeping saturation
aloft...indicative of High clouds. Meanwhile within the tropical
flow aloft...a weak short wave over Missouri was producing some
showers. HRRR suggest this feature to arrive in Central Indiana
after 00Z...and GFS hints at a weak short wave. Thus given this
possible forcing and the moist flow in place aloft...will need to
keep some shower chances...albeit rather low in the forecast for
the first half of the evening before trending toward a dry
forecast late tonight.
Given the expected cloud cover will trend lows at or above the
forecast builder blend.
&&
.SHORT TERM /Saturday through Monday/...
Issued at 153 PM EDT Fri Oct 6 2017
GFS and NAM suggest the warm front north of Central Indiana will
quickly surge northward on Saturday a strong upper trough begins
to dig through the Central Plains states. This allows a
progressive southerly flow to establish across Indiana ahead of
the trough...allowing warm and moist gulf air to surge into the
Ohio valley. A strong Cold front associated with the upper wave is
expected to push across Central Indiana near 00Z Sunday. With
ample moisture and good forcing in place...showers and
thunderstorms seem very reasonable. Forecast soundings hint at a
saturated column and Time heights show good lift. Thus will try
and keep much of Saturday dry...but will include pops at or above
the forecast builder blends after 22Z and before 03Z Sunday as the
cold front passes.
Strong drying is then seen within the forecast soundings by 06Z
Sunday. Strong subsidence in the wake of the front is expected to
settle across much of central Indiana through Sunday morning. THus
will trend toward a decreasing cloudiness sky and stick close to
the blend on temps.
Models continue to suggest that the tropical plume of moisture
will be established just a bit farther east on Sunday afternoon
and Monday. This will allow remnants of Tropical Storm Nate to
sweep through the deep south and allow moisture to arrive in SE
Indiana by Late Sunday afternoon and evening. Confidence on how
for northwest moisture from this feature is low...particularly
with a tropical system.But for now will try and keep pops
contained to mainly the SE parts of the forecast area...and mainly
late in the day and evening hours on Sunday.
Models suggest dry weather and subsidence on Monday as the
forecast soundings show a dry column. Models suggest that the
tropical flow aloft appears to be diverted farther east...allowing
dry air from the west to build across the region. Meanwhile at the
surface Indiana appears to be under the influence of strong high
pressure system over the NW plains states and surface ridge
extending east to the Great Lakes providing anti-cyclonic
circulation. Thus will trend toward a dry forecast and stick
close to the blend on temps here.
&&
.LONG TERM /Monday night through Friday/...
Issued at 233 PM EDT Fri Oct 6 2017
The long term period will be active, with off and on chances for
showers throughout. An upper trough moving through will keep
chances for rain in the forecast as little upper waves move
through the upper trough. Temperatures will run near normal or
just above with low to mid 70s for highs and low to mid 50s for
lows. Confidence in timing of any particular wave is low, so
generally looking at low chance pops throughout. Instability
doesn`t appear to amount to much so left any mention of thunder
out.
&&
.AVIATION /Discussion for 070600z TAF Issuance/...
Issued at 1100 PM EDT Fri Oct 6 2017
Good confidence in mostly VFR conditions through at least 18z per
the SREF and GFS LAMP. Moderate to good confidence the overnight
will be dry.
Then, a cold front will approach the western terminals tomorrow
afternoon. Good chance of showers and possibly storms after 18z from
west to east. Could at times see tempo MVFR in the heavier
convection.
35 knot low level jet could result in some low level wind shear 07z-
13z at KLAF and KHUF. Otherwise, south winds around 5 knots will
increase to 10 to 15 knots after 18z. Gusts to 25 mph plus possible,
especially within any line of convection that forms.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...Puma
NEAR TERM...Puma/MK
SHORT TERM...Puma
LONG TERM....CP
AVIATION...MK
Area Forecast Discussion
National Weather Service San Angelo TX
615 PM CDT Fri Oct 6 2017
.AVIATION...
/00Z TAFS/
VFr conditions continue across West Central Texas early this
evening, and will continue into the overnight hours. Cold front
across Western Kansas will drop rapidly south overnight and move
into the area before morning. Latest HRRR has sped the front up
considerably over earlier models, and given the distance the front
has to come, this seems a little too fast. Will speed the timing
up on the front slightly through, just not to HRRR speeds. Will
trend with the HRRR however on a brief window of MVFR cigs along
the front, along with a few showers possible with the front at
KABI. MVFR cigs would be short lived however, with rapidly
clearing skies across the entire area for Saturday.
&&
.PREV DISCUSSION... /issued 335 PM CDT Fri Oct 6 2017/
SHORT TERM...
(Tonight and Saturday)
A potent shortwave trough currently moving across the Rockies,
will move east across the central and southern Plains states
tonight. An associated cold front will move south across the area
late tonight and Saturday morning. The front is expected to enter
the Big Country after 3 AM and clear far southern counties around
noon. Best lift associated with the upper trough will largely remain
north of the forecast area but will clip the Big Country overnight.
Latest Hi-Res model data shows a line of convection developing along
the front northwest of the area this evening, then tracking
southeast across the Big Country and weakening after midnight.
Will maintain chance POPs generally along and north of I-20 tonight,
with slight POPs extending south across northern portions of the
Concho Valley and Heartland counties. Precipitation is expected to
be light, with most areas seeing 1/0 inch or less of rainfall.
Breezy north winds will develop behind the front on Saturday, with
skies clearing during the day. Temperatures will be a little cooler
on Saturday, with afternoon highs in the low to mid 80s.
LONG TERM...
(Saturday night through Friday)
Light winds and mostly clear skies will result in ideal radiational
cooling conditions Sunday morning, allowing temperatures to drop
into the mid 50s to near 60 degrees for most locations.
Unseasonably hot temperatures are forecast on Sunday, with highs
in the upper 80s to lower 90s.
The next upper level trough is forecast to swing across the Plains
late Monday into Tuesday, sending a cold front through West Central
Texas sometime Monday afternoon into Monday night. Compressional
heating ahead of the front will result in hot temperatures, with
many locations getting into the lower to mid 90s. A faster cold
front would result in cooler temperatures by afternoon for many
locations. For now a compromise between the faster ECMWF and the
slower GFS was used, with the front moving through the region
during the late afternoon/evening hours. Isolated showers and
thunderstorms will be possible along the front, mainly across our
southeast counties where better moisture will reside. Much
drier/cooler temperatures are forecast behind the front. Highs on
Tuesday will mainly be in the low to mid 70s with overnight lows
in the upper 40s to lower 50s. A slow warm up will ensue through
the end of the work week.
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 66 82 56 89 / 30 5 0 0
San Angelo 67 85 57 92 / 10 5 0 0
Junction 68 85 59 91 / 10 10 5 0
Brownwood 67 84 57 89 / 20 5 5 5
Sweetwater 64 82 57 89 / 30 5 0 0
Ozona 65 83 57 89 / 10 5 0 0
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
07