Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 09/11/20
Area Forecast Discussion...UPDATED
National Weather Service Corpus Christi TX
924 PM CDT Thu Sep 10 2020
Quick update to lower temps overnight across the board and also to
taper PoPs to isolated everywhere except the marine zones. Temps
at 9 PM had already eclipsed lows for some locations, with a
refreshing 69 degrees at CRP thanks to a break in low clouds.
Temps may not fall much more than this as some additional low
clouds should redevelop over the Coastal Plains later tonight.
Otherwise, rain chances appear sparse everywhere except along a
stationary front anchored from just E of Matagorda Bay south to
Buoy 20. Latest NAM and HRRR keep this boundary largely fixed
through Fri morning with little in the way of convection drifting
farther west toward our coastal counties.
.PREV DISCUSSION... /Issued 636 PM CDT Thu Sep 10 2020/
Good confidence in MVFR with occasional IFR CIGs holding tight at
COT and LRD through much of Friday, with less confidence in low
CIGs farther east. The leading edge of VFR was hanging just E of
ALI at 630 PM behind some showers, but models are mixed on how
persistent this VFR window will behave overnight. Generally we
expect some lower CIGs toward daybreak from VCT-CRP-ALI, but this
timing could be several hours off in either direction. VFR is
likely by midday over the eastern terminals with some spotty
showers at best. Expect steady N winds through the period.
.PRELIMINARY POINT TEMPS/POPS...
Corpus Christi 69 89 74 92 76 / 20 20 20 10 10
Victoria 68 90 72 92 74 / 20 20 10 10 10
Laredo 65 84 72 91 74 / 20 20 20 20 20
Alice 68 89 73 93 74 / 20 20 20 20 10
Rockport 71 90 76 93 79 / 20 20 20 10 20
Cotulla 66 87 71 91 74 / 20 20 20 10 10
Kingsville 68 90 74 92 75 / 20 20 20 20 10
Navy Corpus 72 89 78 92 80 / 20 20 20 10 20
Area Forecast Discussion
National Weather Service State College PA
1115 PM EDT Thu Sep 10 2020
A weak cold front will push south of the area later tonight.
Tropical moisture that brought portions of Southeastern PA in
excess of one inch of rain today will drift northeast of the
region and toward Long Island and the Southern New England
Coast tonight and Friday.
High pressure will slide across southeastern Ontario and into
northern New York State by late Friday. This weather feature
will push dry air south into the state during the day Friday.
An upper level trough and associated front are likely to push
into Pennsylvania Sunday. An extended period of dry and early
autumnal weather will occur for much of next week.
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
A weak cold front extended from KBGM to KUNV and KAOO at 0045Z
and will drift slowly SE overnight. Latest RAP model indicates a
fairly strong area of 925-850 mb Theta-E convergence
consolidating over the Central and Western Poconos along with
parts of the Middle Susq Valley between about 05-10Z Friday.
This Model highlights this feature the best while the HREFV2
shows a similar area of showers and possible areas of 0.10-0.25
of an inch of rain near and just to the south of a KSEG to KAVP
Elsewhere, and showers should be sparse and brief overnight and
mainly near and to the SE of I-81 in Scent PA.
An area of mainly clear skies was seen on nighttime cloud
microphysics channel - immediately behind the sfc front,
followed by a transition to widespread bkn-ovc stratocu clouds
across the NW zones. These clouds remain shallow and warm, so
no measurable precip is expected.
Min temps early Friday will vary from the mid 50s across the
northern tier to the mid and upper 60s in the Southeast.
Light and variable wind will become NNW at 4-7 mph late tonight.
.SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/...
Drier air should filter in from the north and mix down from
above. The lower clouds will break up over most of the area. We
could see a big drop in Td if we can mix higher than 3-4kft. 8H
temps get down to around 13C, but we may not get up to 8H with
the mixed- layer. We will hold the line on maxes with nr 70F in
the nrn mtns and just below 80F in the srn valleys.
.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
Friday night and most of Saturday continue to look dry. any
showers won`t mover into the Western Mtns and Laurel Highlands
until late in the day Saturday, or more likely after dusk as a
warm front lifts NE from the Ohio River Valley.
Pops increase to the Sctd-Likely range Sat night and early
Sunday, with the lowest chances of rain being across the Susq
Valley and points east, given increasing low-mid level
warm advection. Best forcing lifts northeast of our area, while
the better airmass is to the southwest.
The upper level trough and frontal boundary moves east and south
of the area rather fast clip, so later Sunday night into early
Monday, any left over showers mainly in the far southeast.
Monday into late Wednesday looks dry at this point, and cooler.
Perhaps some showers after this with secondary push of cooler
air behind returned southwest flow.
.AVIATION /03Z FRIDAY THROUGH TUESDAY/...
Lower clouds return overnight as winds turn northerly. IFR most
likely in JST/BFD, while MVFR likely elsewhere after 06z. These
will then break up in the morning - quickly over the east and
more gradually over the west.
Fri-Sat AM...Mainly VFR conditions expected. AM valley fog poss.
Sat PM-Sun...Lowered flight categories possible with SCT
Area Forecast Discussion
National Weather Service Wichita KS
926 PM CDT Thu Sep 10 2020
Issued at 922 PM CDT Thu Sep 10 2020
Low level moisture and low cloudiness has led to patchy areas of
drizzle across most of the forecast area this evening. So will a
drizzle mention going for the rest of the evening as low level
moisture remains high. Seeing more widespread rain moving north
across western OK, at this time, and expect this area of rain to
slowly lift N-NE into the forecast area late tonight or by early
Friday morning as main upper low over the Rockies continues to
lift to the E-NE. Latest RAP doesn`t show much instability as this
area of rain lifts north, so thinking mainly rain as it moves
across the area. So plan on taking out all thunder mention for the
As the upper low lifts E-NE, expect to see a scouring of the low
level moisture initially over the high plains and eventually from
west to east across KS during the day on Fri.
.SHORT TERM...(This evening through Sunday night)
Issued at 240 PM CDT Thu Sep 10 2020
A cold and stable post-frontal regime was firmly entrenched across
the Central Plains states today with light north winds and abundant
cloud cover keeping high temperatures well below climate normals for
Another batch of rain currently over the West Texas Rolling Plains
is progged to lift north and east towards the area tonight bringing
another round of light rain to much of south central and southeast
Kansas. Areas of drizzle will also be possible, especially in areas
that do not receive light rain.
The mid/upper trough over the Rockies will begin to lift north and
east toward the Northern Plains on Friday allowing light southerly
flow to return to the Central Plains region. This will result in
moderating temperatures across the area although highs will remain
well below normal for early September with values topping out in the
mid and upper 60s. Low pops were maintained over far southeast
Kansas although the best chances should be weighted early in the
period with some sunshine possible across parts of central and south
central KS before the day ends.
Sat-Sun...Dry and pleasant weather conditions are anticipated as we
move through the weekend. High temperatures are expected to climb
to around 80 for most areas with lows in the 50s.
.LONG TERM...(Monday through Thursday)
Issued at 240 PM CDT Thu Sep 10 2020
Tranquil weather conditions are expected to continue for much if
not all of the upcoming week as temperatures slowly moderate
becoming near normal toward the end of the period. There remains
some uncertainty towards the end of the period as the ECMWF drives
another sharp cold front southward towards the region while the
GFS maintains mid/upper ridging across the Southeastern U.S.
leading to increasing uncertainty as we move towards the latter
portion of the week.
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 638 PM CDT Thu Sep 10 2020
MVFR to IFR cigs will continue for all TAF locations overnight into
the morning hours on Fri. Expect most locations to see low end MVFR
cigs around 1200 feet AGL, but as the overnight progresses, widely
scattered showers may move north out of srn OK, and move into the
area. So will go with a VCSH for this chance. But as the SHRA
move in, saturation will lead to cigs dropping into the IFR range
around 900 feet AGL. Will not go with any vsby restrictions until
the SHRA materialize.
Main upper low currently over the Rockies will finally sweep E-NE of
the area on Fri, with a general scouring out of the low level
moisture by around 18z/Fri.
.PRELIMINARY POINT TEMPS/POPS...
Wichita-KICT 54 67 57 82 / 50 40 0 0
Hutchinson 52 66 54 82 / 40 30 0 0
Newton 52 66 56 81 / 50 40 10 0
ElDorado 53 65 57 80 / 60 50 10 10
Winfield-KWLD 54 66 57 81 / 60 50 10 10
Russell 51 68 54 79 / 40 30 0 0
Great Bend 50 67 53 79 / 40 30 0 0
Salina 52 67 55 81 / 40 30 0 0
McPherson 51 65 54 81 / 40 30 0 0
Coffeyville 56 65 59 81 / 60 50 20 10
Chanute 55 65 58 81 / 60 50 20 10
Iola 55 65 58 81 / 60 50 30 10
Parsons-KPPF 56 65 59 81 / 60 50 20 10
Area Forecast Discussion
National Weather Service Portland OR
252 PM PDT Thu Sep 10 2020
.SYNOPSIS...Easterly winds through the Gorge will end tonight as a
trough of low pressure in the Willamette Valley shifts east of the
Cascades. Widespread dense wildfire smoke and poor air
quality will likely persist into early next week. Onshore flow
returns to the region Friday and into the weekend bringing
progressively cooler air inland along with increased moisture levels.
A trough of low pressure early next week returns chances for showers
to the region.
.SHORT TERM...Tonight through Sunday...Offshore flow is weakening
across the area. Surface analysis shows the thermal trough over the
interior valley, south across the Rogue Valley into northern CA.
Light east winds from the Gorge will continue to ease tonight and
it`ll help keep parts the Portland/Vancouver metro area from the
worse air quality experienced to the north and south. By Friday
morning Portland/Vancouver areas will likely see poor air quality as
the Gorge outflow ends. HRRR smoke model and forecast soundings
indicate smoke will be trapped at low levels into Monday. Even for
the coastal areas as there is a lot of smoke over the waters that
will be advected back onshore. Models have not been performing well
with regard to temperatures with the thick smoke cover, so used
persistence as a forecast for the near term. So instead of 90s for
the interior valley it will be in the upper 70s to low 80s. Coastal
areas will be cooler as a southerly wind reversal has brought a
shallow marine layer there. The axis of the upper ridge shifts
inland Friday and Saturday while weakening slightly. Low level
onshore flow will begin to spread marine air, gradually bringing
cooler air inland with rising moisture levels.The upper ridge is
replaced by a southwest flow aloft Saturday night and Sunday as a
trough over the east Pacific shifts closer. This will strengthen the
onshore flow, bringing even cooler marine air inland along with
morning marine clouds into the Willamette and Lower Columbia Valleys.
.LONG TERM...Sunday night through Thursday...The early part on next
week brings even cooler temperatures and the promise of some
precipitation as an offshore trough approaches. The operational GFS
is the most progressive with the upper trough shifting inland on
Wednesday, but he ECMWF and GEM are tending to keep the low further
offshore with the forecast area on the edge of the precipitation
chances. For now will weight the forecast toward ECMWF/GEM and ECMWF
ensemble solution since the current GEFS operational ensemble member
on the wetter side of the ensemble mean. On Monday it looks like a
warm front should brush the forecast area with some light rain as
models are in similar agreement. By Tue afternoon if the GFS pans
out we may see a slight chance for thunderstorms over the interior,
from the interior valley to the Cascades. Confidence is low at this
time given the differences in the models but is worth mentioning at
this time. The remainder of the week will have a chance of some
light precipitation but as the upper trough nears or moves across the
forecast area.With greater marine influence, expect temperatures
next week to be more seasonable.
.AVIATION...Covering the 00Z TAF issuance...Little to no
improvement across the region as smoke continues. Reduced
visibility west of the Cascades will continue for the next 24
hrs. The OR/CA thermal low will continue to extend north over the
Willamette Valley bringing light and variable winds across the
region. Models still have little to no grasp on ceiling or
visibility conditions so persistence should still be expected.
Winds will have a southerly component to them so dense smoke from
central and southern Oregon will move north.
All inland sites aside from the Portland metro area are in MVFR
to IFR criteria. A smoke deck around 025 is being observed across
much of the Willamette Valley with visibility between 0.5 and
The southerly surge off the coast will continue to deepen the
marine boundary layer. Slight onshore winds will bring marine air
inland, however air off the coast is filled with smoke from the east
winds. Southerly stratus will be mixed with CA wildfire smoke
as well as smoke that has been drifting over the ocean. Current
conditions along the coast will continue to be IFR to LIFR
throughout the day.
Refer to http://weather.gov/zse for detailed regional aviation
weather and hazard information.
KPDX and APPROACHES...Light and variable winds are expected for
the next 24 hrs. Smoke will continue and worsen throughout the
day as winds push smoke north. A mix of IFR to MVFR conditions
are likely going into this evening. -BPhillips
.MARINE...Southerly surge of stratus will continue up the coast
going into this evening and through tomorrow morning. South winds
will be light with gusts less than 15 kt. There are multiple
small swell trains in the Pacific that range between 1 to 2 ft at
13-15 sec. Therefore, wind waves will be the primary component
of significant wave heights that will stay below 5 ft. The
primary hazard will be the smoke coupled with the stratus deck
moving north around 300 ft. This will reduce visibility along
the nearshore below 1 mile in some places. Patchy smoke is
likely out to 60nm. A front is expected to move across the
waters Monday night into Tuesday which may bring SCA winds across
the area. -BPhillips
Interact with us via social media:
Area Forecast Discussion
National Weather Service Shreveport LA
1017 PM CDT Thu Sep 10 2020
To tweak a few low temps and pops/wx for the overnight.
Still some very small, occasional showers popping up mainly in SW
AR with the stalled frontal boundary lying over E TX. Lowered a
few NE TX temps for the overnight with fair skies and some room to
fall before saturation. HRRR doesn`t really high light much area
wise, but a few QPF bubbles in SW AR and SE TX are to be noted.
Amounts from any showers will be trace for a few hundreths is all.
.PREV DISCUSSION... /issued 720 PM CDT Thu Sep 10 2020/
For the ArkLaTex terminals, a weak fropa is drifting Eastward
across Eastern TX from near KOCH to near KSHV to KTXK. We may see
a few vicinity showers overnight and once more thunderstorm
coverage will ramp up in the heart of our area during peak
heating 18-24Z again on Friday. In fact, the boundary will be
washing out in place for the most part into the weekend. Light N
winds will continue as our terminals with gusts near any heavy
downpours for Friday with similar coverage for this weekend too.
PREV DISCUSSION... /issued 306 PM CDT Thu Sep 10 2020/
SHORT TERM.../Tonight through Friday night/
The recently advertised frontal boundary has finally made it into
the region today. However, it has only progressed as far east as
East Texas and SE Oklahoma, generally along a line from Idabel
Oklahoma to Gilmer Texas to near Jacksonville Texas.
Unfortunately, for those expecting cooler conditions will be
disappointed as the frontal boundary is not expected to move much
more to the east as a Bermuda Ridge extending from the East Coast
of the US westward into the Lower Mississippi Valley will halt its
progression. Due to the shallow nature of the boundary, post
frontal low cigs have moved in place and should hold for the
remainder of today into Friday. The cloud cover along with the
post frontal airmass has resulted in cooler conditions, as most
post frontal locations have remained in the 70s today. Ahead of
the boundary, much warmer conditions exist, with temperatures in
the upper 80s to low 90s. Also, with less cloud cover, differential
heating has resulted in isolated to scattered showers and
thunderstorms developing over portions of Deep East Texas,
Northern Louisiana, and Southwest Arkansas. Look for this trend to
continue over the next several hours, with thunderstorms
eventually diminishing by late this evening. Temperatures will
fall into the mid to upper 60s for areas behind the boundary,
with low 70s across the remainder of the region.
By Friday, upper ridging will continue to build into the region
resulting in the frontal boundary mixing out. However, isolated
showers and thunderstorms will be possible again with the best
chances near the residual boundary. The range in afternoon
temperatures will remain as well, as highs will struggle to reach
the mid 80s in areas behind the previous boundary as low ceilings
should hold in place in those areas. The remainder of the region
will see temperatures in the upper 80s to lower 90s again.
Convection should be less in coverage tomorrow afternoon, with
activity diminishing around sunset. /20/
LONG TERM.../Saturday through Thursday/
To begin the weekend, the closed low will continue filling as it
proceeds across the Northern Great Plains. The cold front trailing
this low will continue to instigate convection throughout next week
as it dissipates. By the middle of next week, southerly flow will
return as the upper-level ridge continues to build in from the west,
allowing for a more active seabreeze, diurnal heating, and thus,
more scattered convection. Temperatures have been adjusted to be
slightly milder later next week as PoPs are slightly elevated in the
same time frame. /16/
.PRELIMINARY POINT TEMPS/POPS...
SHV 72 90 71 91 / 20 20 0 10
MLU 71 93 73 92 / 10 20 0 30
DEQ 68 84 68 88 / 20 20 0 10
TXK 69 86 69 88 / 20 20 0 10
ELD 69 90 69 90 / 10 20 0 10
TYR 65 84 68 88 / 10 20 0 10
GGG 69 86 69 91 / 20 20 0 10
LFK 71 89 71 93 / 20 20 0 10