Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 08/17/22
Area Forecast Discussion
National Weather Service Dodge City KS
1100 PM CDT Tue Aug 16 2022
...updated aviation...
.SHORT TERM...(This evening through Wednesday)
Issued at 1257 PM CDT Tue Aug 16 2022
Main challenge tonight will be precipitation chances and
potential for heavy rainfall from storms moving across portions of
extreme southwest Kansas.
CAMS are coming into better agreement today with a moist upslope
flow developing this Tuesday afternoon across southeast Colorado
and the Panhandle of Oklahoma. This moist upslope flow combined
with afternoon heating will likely result in scattered afternoon
convection across southeast Colorado. These thunderstorms will
then track southeast along this moist instability axis overnight
and 700mb 10-12C temperature gradient which would place locations
near and southwest of a Lakin to Meade line in a favorable area
(30-80%) for overnight thunderstorms. Highest/most favorable area
will be Morton county (80%). Thunderstorms that do cross this area
overnight will be capable of producing heavy rainfall based on
the RAP forecast of precipitable water values in this area ranging
from 1.4 to 1.6in and 12z Tuesday HREF has a +70% probability of
>=1” 6hr rainfall appearing across Morton county from 00z to 06z
Wednesday. Later shifts will monitor the flash flood potential
but at this time given the high 1, 3, 6hr flash flood guidance
tonight and how isolated the heavy rainfall is expected have
decided not to issue a Flash Flood Watch for tonight for extreme
southwest Kansas. Isolated wind gusts of 50 to near 60mph will
also be possible early in the event, before sunset.
This cluster of thunderstorms will continue to track across the
Panhandle of Oklahoma/Texas Panhandle and into western Oklahoma
early Wednesday. Any lingering precipitation, mainly near the
Oklahoma border is expected to taper off after 18z Wednesday as an
upper level trough moves across western Kansas. Temperatures will
be unseasonably cool with highs ranging from the upper 70s to
lower 80s.
.LONG TERM...(Wednesday night through Tuesday)
Issued at 1257 PM CDT Tue Aug 16 2022
The key message in the later periods are the extended cooler,
more seasonal, temperatures. Will also be monitoring the potential
for some widespread rain returning to portions of southwest
Kansas.
The latest ECMWF and GEFS ensembles remain in generally good
agreement through the end of the week with the largest discrepancy
over the weekend being the strength and exact location of an
upper low that will be moving out of south central Canada and into
the western Great Lakes. A cold front will be working its way
south across the Northern Plains but at this time it appears that
this front and cooler air now will be ending up staying north
southwest Kansas. This further north cold front position solution
does support not introducing a cooling trend this upcoming
weekend..HOWEVER given that both the ECMWF and GEFS ensembles both
are showing that a 500mb deformation zone along with a increasing
moisture and lift over some part of southwest Kansas which would
not only favor increasing chance for precipitation but will also
result in cooler temperatures. Confidence at this time is not high
that far out in the forecast period on exactly where this
moisture, lift and cooler temperatures will be located so stay
close to the latest guidance for a chance for precipitation or
high temperatures from Sunday through early next week. Given all
this it appears southwest Kansas will enjoy highs in the 80s
through Friday with upper 80s to lower 90s being possible until
the clouds and precipitation returns due to the developing
deformation zone. The coolest temperatures late this weekend into
early next week along with improving chances for precipitation
will occur west and south of Dodge City. In this area highs only
in the 70s look to be a real possibility if everything comes
together.
&&
.AVIATION...(For the 06Z TAFS through 06Z Wednesday night)
Issued at 1111 PM CDT Tue Aug 16 2022
A weather system will impact the terminals through the overnight hours.
Showers with isolated thunder will continue across far SW Kansas, with
the main impacts at KLBL through the early morning. In addition, upslope
stratus will continue to fill in across the terminals through the next
several hours. MVFR/IFR cigs will be likely during this period. There
could be some patchy fog/br across central Kansas where the moisture
is more confined to the near sfc. Winds will remain NE 5-15 kt through
much of pd.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 61 79 58 88 / 30 20 0 10
GCK 61 80 57 87 / 50 10 0 10
EHA 61 76 58 86 / 70 60 0 20
LBL 63 78 59 87 / 70 60 0 10
HYS 62 81 57 88 / 10 10 0 0
P28 65 80 60 87 / 30 20 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Burgert
LONG TERM...Burgert
AVIATION...Sugden
Area Forecast Discussion
National Weather Service Pendleton OR
840 PM PDT Tue Aug 16 2022
.UPDATE...High pressure is forecast to dominate the areas weather
with dry conditions and hot temperatures for the remainder of the
week. Afternoon high temperatures across the Columbia Basin are
expected to climb toward 100 degrees and higher and a heat
advisory remains in effect for a large part of the region into
Friday.
Meanwhile high pressure just to our east will remain nearly
stationary and some moisture may rap around and into portions of
central Oregon tomorrow afternoon that could produce an isolated
thunderstorm.
Otherwise minor changes were done to sky and overnight
temperatures tonight and the present short term forecast appears
on track.
&&
.PREV DISCUSSION... /issued 445 PM PDT Tue Aug 16 2022/
SHORT TERM...The main challenges with the short-term forecast
revolve around a couple shortwaves anticipated to ride around the
upper-level ridge on Wednesday and Thursday. The first of these
waves is currently visible off the northern California coast on
water vapor imagery. Monsoonal moisture transport up the back side
of the ridge will reach central Oregon and the Cascade crest
Wednesday morning and afternoon. This moisture, combined with
some weak synoptic lift from the shortwaves may facilitate
elevated showers and isolated thunderstorms for the central Oregon
Cascades, central Oregon, and Ochocos Wednesday afternoon.
Overnight into Thursday, guidance advertises another vorticity
maximum moving onshore and forming a weak mid-level low. The
current track is forecast to move southwest to northeast across
eastern Oregon or northern Nevada, though guidance is still
struggling with this feature. Thus, while additional lift will be
provided by the low, confidence in exact placement of showers and
isolated thunderstorms is low for Thursday afternoon into
Thursday night. The majority of the moisture is anticipated to
push along the Cascade crest Thursday, with perhaps some spilling
into the rest of eastern Oregon Thursday evening and night. Have a
slight chance of thunderstorms forecast for the Cascade crest on
Thursday, as this is where the best instability and moisture is
expected.
The other concern for Wednesday and Thursday will be very hot
temperatures for much of our CWA. Widespread highs in the 95-105
range are forecast Wednesday, and multiple Heat Advisories will be
in effect Wednesday morning through Friday evening. Thursday, more
uncertainty surrounds afternoon temperatures with potential mid-
level cloud cover due to the monsoonal moisture and potential
convective debris from any activity on Wednesday. Highs in the
95-105 range are still forecast, but these may come down a few
degrees should cloud cover inhibit daytime heating. Regardless,
advisory level heat will likely continue through the short term.
Plunkett/86
LONG TERM...Friday through Tuesday...Upper ridge will continue to
weaken as an upper trough off the coast tries to move into the
region. The forecast area will be in the saddle between the upper
ridge to the east and the upper trough off the coast to the
northwest, and another upper ridge to the southwest along the CA
coast. There will be some weak instability, but very little
moisture, so Friday looks to be dry. However, cannot rule out an
isolated weak thunderstorm over Wallowa County, but the chances
are very small, with low confidence. Temperatures still look to be
in the upper 90s to lower 100s in the lower elevations and mostly
80s to lower 90s mountains on Friday. Friday night and Saturday,
the upper trough off the coast and the upper ridge over Montana
will cause a southwest to west flow over the forecast area. There
will also be a subtle upper low over the great basin, but that
will have no effect on the weather in the CWA. Therefore, at this
time, it looks to remain dry through Saturday night into early
Sunday. However, the upper trough off the coast is now forecast by
both the ECMWF and GFS to move into the region and forecast area
by Sunday afternoon. This will result in a slight chance of
thunderstorms over mainly the Elkhorn and Wallowa Mountains.
However, elsewhere it will stay dry. A slight chance of
thunderstorms will persist Sunday evening, and then dissipate
overnight. There may still be a few showers, mainly over Wallowa
County and the northern Blue Mountains Sunday night and Monday
morning. Then with afternoon heating on Monday, combined with the
upper trough that will still be moving across the region, there
will be another slight chance of thunderstorms over Wallowa
County. Then on Tuesday, a drier northwest flow will develop
behind the trough as it departs the region. Tuesday looks to be
dry. Temperatures on Monday and Tuesday will be cooler, with highs
in the 90s in the lower elevations, and mid 70s to mid 80s
mountains. While these temperatures are still above normal, it
will feel cooler compared to the triple digit heat in the short
term and in the early long term forecast period.
It will be breezy to windy in the eastern Columbia River
Gorge/north central OR area, as well as possibly the Kittitas
Valley Friday afternoon and evening. After that winds look to be
mostly light, except for the usual locations where winds tend to
increase during the afternoons and evenings, such as the eastern
Columbia Gorge and Kittitas Valleys.
AVIATION...vfr conditions are expected to continue for the next
24 hours. Winds are forecast to remain between 5 to 20 mph.
Meanwhile taf sites krdm and kbdn may experience few-sct100 after
20z.
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 61 101 65 99 / 0 0 0 0
ALW 63 104 67 102 / 0 0 0 0
PSC 64 104 68 103 / 0 0 0 0
YKM 60 101 67 103 / 0 0 0 0
HRI 62 105 67 103 / 0 0 0 0
ELN 60 102 66 103 / 0 0 0 0
RDM 56 99 64 95 / 0 20 20 10
LGD 59 100 62 96 / 0 0 0 0
GCD 59 104 64 97 / 0 0 0 0
DLS 67 105 75 103 / 0 0 0 10
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...Heat Advisory from 11 AM Wednesday to 11 PM PDT Friday for
ORZ041-044-049-050-502-503-505>508-510-511.
WA...Heat Advisory from 11 AM Wednesday to 11 PM PDT Friday for
WAZ024-026>030-520-521.
&&
$$
SHORT TERM...97
LONG TERM....99
AVIATION...97
Area Forecast Discussion
National Weather Service Las Vegas NV
830 PM PDT Tue Aug 16 2022
.SYNOPSIS...Scattered showers and thunderstorms will persist
through the week as monsoonal moisture remains over the region, and
any storms will be capable of producing locally heavy rain and
flooding. With the abundant moisture in place, temperatures will
remain near to slightly below normal into the weekend.
&&
.UPDATE...A few thunderstorms were persisting after sunset and
moving from southwest Lincoln County into the area around Indian
Springs and Mercury early this evening...similar to convective
development that occurred Monday evening. The 00Z Las Vegas sounding
and the most recent mesoanalysis indicate the environment is more
stable than 24 hours ago with mixed layer cape values around 100-200
J/kg and most unstable CAPE values around 200-400 J/kg. The
northeast steering flow aloft should direct any additional
development toward the Pahrump Valley. The latest HRRR indicates
this trend, but can`t completely rule out some showers or
thunderstorms brushing the northern portion of the Spring Mountains
and far northwest parts of the Las Vegas Valley through late
evening. -Adair
&&
.PREV DISCUSSION...
1227 PM PDT Tue Aug 16 2022
.SHORT TERM...through Wednesday night. Late morning satellite loop
showed shallow cumulus bubbling over much of the CWA, with deeper
convection beginning over the Hualapai Mountains and in southern
Esmeralda County. Surface obs showed temperatures running a few
degrees warmer than 24 hours ago, although still well below mid
August averages, and dewpoints a few degrees lower than yesterday.
With the deep moisture and some instability in place, no spot can be
completely ruled out for thunderstorm chances this afternoon and
evening, although the high resolution models are in decent agreement
that the lowest chances will be in the Death Valley region and the
lower elevations of Clark County. Models show a bit less instability
Wednesday, resulting in a bit less thunderstorm coverage as well.
However, this could be modified if any storm-scale circulation
generated today drifts nearby Wednesday. Nocturnal storm chances
look small tonight, but some of the high res models show storms
persisting Wednesday night in the southern Great Basin. Temperatures
will remain below normal thanks to the deep moisture and cloud cover.
.LONG TERM...Thursday through the weekend.
Continued southerly flow is expected across the region through the
weekend. While thunderstorms are possible Thursday afternoon, models
continue to highlight the Friday through Sunday period as period of
potentially higher impact monsoonal weather. PWAT increase across
the region to over 2 standard deviations over normal by Friday
afternoon as tropical moisture gets absorbed into mean flow.
While its hard to pin point mesoscale features this far in
advance, long range models hint at a wave moving around the main
flow Saturday into Sunday, which could enhance precipitation
chances/coverage. This potential uptick in activity and increased
risk of heavy rain leading to flash flooding is highlighted in a
few ensembles. ECMWF EFIs shows potential for anomalous QPF
through portions of Arizona into eastern portions of southern
Nevada FRI-SUN. Model ensembles also show increased probabilities
for 100 yr ARIs at times late Friday through Sunday. Finally, some
of the clusters show QPF over the ensemble means through the
weekend. While details are uncertain at this time, there is an
increasing signal for an increased thunderstorm activity, heavy
rain, and flash flooding this weekend. What is more certain is the
continuation of below-normal temperatures with the persistent
moisture and rain chances.
&&
.AVIATION...For Harry Reid...Monsoon moisture will remain in place
again today with FEW-SCT12-14k feet and SCT-BKN15-17k feet. Outside
of any thunderstorm influences, winds will generally be east around
6-8 kts. Conditions are expected to remain the same Wednesday with
scattered afternoon thunderstorms, majority remaining over the
higher terrain.
For the rest of southern Nevada, northwest Arizona and southeast
California...Thunderstorms were dissipating this evening and are not
expected to impact TAF sites, though outflow outflow winds from
decaying storms could affect TAF sites into this evening. Outside of
convection, winds will in general favor diurnal wind trends, except
at KBIH where gust southeast winds are expected this afternoon.
&&
.SPOTTER INFORMATION STATEMENT...Spotters are encouraged to report
any significant weather or impacts according to standard operating
procedures.
&&
$$
SHORT TERM...Morgan
LONG TERM...Nickerson
AVIATION...Gorelow
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