Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 08/13/19
Area Forecast Discussion
National Weather Service Dodge City KS
1020 PM CDT Mon Aug 12 2019
...UPDATE TO SYNOPSIS...
.SYNOPSIS...
Issued at 1020 PM CDT Mon Aug 12 2019
WV imagery indicates a westerly flow aloft prevailing across the
Western High Plains. Near the surface, a near stationary frontal
boundary extends from the Texas Panhandle eastward into western
Oklahoma.
&&
.SHORT TERM...(This evening through Tuesday)
Issued at 312 PM CDT Mon Aug 12 2019
A weak surface front was located along the southern counties with
Oklahoma this afternoon. A few thunderstorms will persist along
this boundary through about 9 pm before moving father south into
Oklahoma. By Tuesday evening, upslope southeasterly flow is
expected to develop across the plains, with an area of surface
convergence in extreme northeastern Colorado. Thunderstorms will
develop in this convergence with surface heating and propagate
southward and southeastward into western Kansas in the evening.
The storms will be severe with large hail and damaging winds in
the evening, especially before reaching as far south as I-70, then
gradually decrease in severity during the late evening and
overnight. It is uncertain how this storm cluster will track; but
the most favored area for now is from Scott City southward to
Garden City and Meade. High winds and heavy rain may be a concern
into the early morning hours Wednesday in places like Garden City,
Ulysses and Liberal. If the storm cluster is father east then
Dodge City and Jetmore could receive heavy rain as well.
.LONG TERM...(Tuesday night through Monday)
Issued at 312 PM CDT Mon Aug 12 2019
Another cluster of thunderstorms is expected Wednesday evening in
a similar setup. Much of western and central Kansas has a chance
of thunderstorms Wednesday night. The same pattern will hold
through Friday, with the best storm chances shifting north to
around Interstate 70. But the aforementioned upper level ridge
should suppress rainfall over the weekend to a more isolated
basis. In general, temperatures will continue to be warmer along
the Oklahoma state line and cooler near I-70.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 619 PM CDT Mon Aug 12 2019
Scattered thunderstorms will be possible over the next few hours
near the Oklahoma border which will include the Liberal area. Wind
gusts in excess of 35 knots is not completely out of the question
with these storms. Bufr soundings indicate mainly lower VFR
ceilings through 03z Tuesday at Liberal. VFR conditions can also
be expected across western and north central Kansas early Tonight.
Winds tonight outside the thunderstorms will be northerly at less
than 10 knots. RAP and NAM soundings do suggest that there will
be an increase in moisture in the 2000 to 3000 ft AGL level at
Dodge City, Garden City and Hays after 09z Tuesday. This may
produce some scattered ceilings around daybreak in the MVFR
category. Any clouds that do develop late tonight will erode by
15z Tuesday.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 66 91 64 89 / 10 0 30 10
GCK 62 91 62 90 / 10 0 60 20
EHA 63 91 63 90 / 20 0 60 20
LBL 65 91 63 90 / 40 0 50 20
HYS 66 90 63 86 / 10 0 30 20
P28 69 91 66 90 / 40 0 20 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...JJohnson
SHORT TERM...Finch
LONG TERM...Finch
AVIATION...Burgert
Area Forecast Discussion
National Weather Service Grand Forks ND
1004 PM CDT Mon Aug 12 2019
.UPDATE...
Issued at 1004 PM CDT Mon Aug 12 2019
Stalled frontal zone near our western CWA still delineate more
unstable air mass and trends continue to show thunderstorm
activity weakening as it moves further east away from favorable
region into more stable air mass. Still, we are we are seeing some
redevelopment towards west central MN, lingering showers in the
northern RRV, and closed low upstream progressing eastward with
shower/storm cluster approaching our west. CAMS still indicate
more widespread activity spreading northwest to southeast late
tonight thorugh midday Tuesday before decreasing in coverage and
ending west to east. Adjustments made to reflect current trends
and towards CAMs consensus.
UPDATE Issued at 642 PM CDT Mon Aug 12 2019
Better defined "lull" in measurable precip returns on radar
across our south and west with redevelopment of showers across
north north central valley, while more reorganized areas of
showers transition east from our far eastern CWA. Adjustments made
to reflect these trends and better time upstream redevelopment of
showers. RAP analysis does show some instability along stalled
frontal zone in our west, but this should show decreasing trends
,and with isolated activity may redevelop (or just some drizzle)
overall there should be a "dry" period during evening/overnight
before next upper low transitions in from the northwest.
Thunderstorm can`t be ruled out in our far west and south, but
trend will be for showers to be favored due to decreasing
instability trends over our CWA.
&&
.SHORT TERM...(This evening through Tuesday)
Issued at 343 PM CDT Mon Aug 12 2019
Rainfall continues to be the main story in the short term. The
rain has pretty much ended at Fargo and is almost done now at
Grand Forks too. The steadiest rain has shifted into northwest
Minnesota, but it will continue to decrease in coverage there
this evening. This will bring somewhat of a break in the steady
precipitation across the area. How much of a break is the main
question. The 500mb low over northeast Montana and northwest ND
will continue to push slowly eastward tonight. There has been
some clearing across the western Dakotas, where some modest
instability has developed. There is decent bulk shear, but not
seeing much of a low level jet tonight. The best forcing will be
right around the 500mb low. SPC did issue a mesoscale discussion a
little bit ago talking about the potential for a few strong
storms across northwest and north central ND late this afternoon
into the early evening.
High resolution model guidance also shows a few stronger storms
developing out west and possibly holding together as they track
into central ND later this evening. Will have to keep an eye on
that possibility. Otherwise, extensive cloud cover remains across
the entire FA, which limited the instability here. However, models
show this cloud cover holding overnight and into Tuesday, which
will hold temperatures up tonight and down Tuesday. Think pcpn
chances will increase again on Tuesday as the 500mb short wave
moves through, but the bigger story is that constant precipitation
is not expected. There will be breaks at times tonight into
Tuesday.
.LONG TERM...(Tuesday night through Monday)
Issued at 343 PM CDT Mon Aug 12 2019
The rain should finally begin to exit out of the FA Tuesday night.
Cool and dry weather mid week will give way to more seasonal late-
summer weather with highs in the 70s/low 80s and chances for showers
and thunderstorms.
Wednesday...
Surface high pressure building in behind the Mon/Tues storm system
will be accompanied by a cooler airmass that will keep temperatures
in the upper 60s and low 70s for Wednesday. Light westerly winds
under partly to mostly cloudy skies will allow for comfortable
weather for mid-August.
Thursday...
Guidance continues to indicate northwesterly flow aloft will allow a
weak upper level impulse and an attendant surface trough to move
into the region Thursday/Thursday night. Since forcing for ascent
will generally be weak only light and scattered showers are
expected. The potential for thunderstorms will largely be dependent
on the timing of the wave. A later arrival time will aid in low to
moderate destabilization via prolonged daytime heating and low level
moisture advection into the region. However, confidence in timing,
and therefore thunderstorm chances, is low at this time due to high
model spread.
Friday through Sunday...
Ensemble and deterministic guidance continue to suggest a return to
a more typical summer time pattern by the late week/weekend period
with more zonal flow aloft and temperatures/dewpoints back into the
80s and low 60s respectively.
Chances for showers and thunderstorms will accompany this warmer
weather as upper level impulses propagate through the region within
the mean flow. Confidence is generally low on specific timing for
rain/T-storm chances with high variation in both deterministic and
ensemble member solutions noted within this period.
Monday...
Long range ensemble guidance suggests that the start of the next
work week should be more quiet than the weekend with mostly dry
weather and seasonal temperatures.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 642 PM CDT Mon Aug 12 2019
Showers continue to transition along and north of Highway 2
corridor with best coverage in north central MN. Stalled front to
our west with high low level moisture had led to widespread
stratus with ceilings varying from 500ft to 3500ft AGL, and
overall trend for tonight twill be for IFR (if not LIFR) ceilings
to prevail. Patchy fog can`t be ruled out, but most vis
restrictions will be dependent on timing of current shower
activity, or next round expected to move into northeast ND late
tonight and shift southeast through the day Tuesday. VFR
conditions may begin to return by the end of the TAF period as
this second system moves east and drier air moves back into our
region from the northwest.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...None.
MN...None.
&&
$$
UPDATE...DJR
SHORT TERM...Godon/Wasilewski/Long
LONG TERM...Godon/AM
AVIATION...DJR
Area Forecast Discussion
National Weather Service Hastings NE
614 PM CDT Mon Aug 12 2019
...Aviation Update...
.SHORT TERM...(This evening through Tuesday)
Issued at 235 PM CDT Mon Aug 12 2019
Aloft: AMDAR/aircraft winds along with WV imgry and RAP dynamic
tropopause analyses indicated moderately-amplified flow dominated
by a subtropical high over the lwr MS river vly. The flow was less
amplified and more zonal at 500 mb with the main belt of
Westerlies acrs the Nrn USA. A small low and accompanying shrtwv
trof was over SA-MT-WY. This trof will cross the Nrn Plns tonight
and begin weakening tomorrow as it mvs into MN. Meanwhile...as
heights begin to rise in its wake over the Rckys...the subtropical
high will retrograde back into NM. This will result in W winds
over NEB/KS becoming WNW.
Surface: Wk low pres was over Srn SA. A wk cool front extended
from this low down to a triple pt low near MCI and then SW to the
OK panhandle. While the front mvs further E and S...the low over
SA will sink into ND with cold frontogenesis to its W. Wk high
pres will develop over NEB tomorrow while this front sags to the
NEB/KS border by 00Z/Wed.
Rest of this afternoon: Partly sunny. Extensive mid-lvl altocu
are associated with a very wk shrtwv trof arcing from NM-KS...with
diurnally-driven stratocu underneath. Temps will peak in the 80s
3-5 PM. Muggy.
Tonight: Diurnal stratocu will dissipate early...and the mid-lvl
clds associated with the very wk trof should move E of the CWA as
that trof does. GFS/NAM/RAP/RDPS (Canadian) all bring in some mid-
lvl RH from the SW after midnight. So skies should become mostly
clr this eve and then turn partly cldy after midnight.
Low-mid 60s...except in the Valleys from LXN-ODX where upr 50s
are likely.
Tue: The fcst reads mostly sunny...but may not have gone high
enough with sky cover. Believe tomorrow will average partly cldy.
Highs in the 80s. But Rooks county could reach 90F. Should be
very comfortable with dwpts fcst to drop into the lwr 60s W of Hwy
81. That will be a nice albeit brief break from the humidity.
.LONG TERM...(Tuesday night through Monday)
Issued at 235 PM CDT Mon Aug 12 2019
Aloft: The last 2 runs of global mdls are tightly-clustered on
low- amplitude WNW flow cont Wed-Thu. Spread begins to increase
Fri and conts to increase thru the wknd. The last 3 EC runs and
its ensemble mean place more emphasis on a low (currently offshore
of BC) dropping into or just offshore of the Pac NW. This induces
a transition to SW flow over NEB/KS. All other global mdls place
more emphasis on a potent trof crossing the Can Prairies...which
maintains WNW flow over the rgn. Interestingly...just looking at
the 12Z mdl runs...the EC has come into the camp maintaining WNW
flow as it keeps the BC low further W than its 2 prvs runs. So
there may be a consensus forming toward WNW flow. Once the Can
Prairies trof moves into Ontario Sat night...a broad ridge is fcst
to form over the Plns.
Surface: The cool front along the NEB/KS border should slip thru
Tue night quickly followed by Nrn Plns high pres Wed. This high
will slide to the E Thu with return flow developing. A Canadian
cool front will drop into the Nrn Plns and cross the CWA Thu night
or Fri mrng. Because of the uncertainty aloft...it`s uncertain
what will happen with this front. Will it stall acrs Nrn KS or
head into OK? Either way...it should dissipate. The EC tells a
diff story. Another Canadian cool front is fcst to sag thru the
Nrn Plns Sat...but it might not make it here if low pres forms
over SW Canada. Lots of uncertainty heading into this wknd.
Temps: Wed will be the coolest day of the wk. Much of S-cntrl NEB
will only reach the 70s. Still a little below normal Thu...then
near normal Fri-Mon.
Precip: As is usual for summer...confidence is not high. Isold-
sct tstms will form each day over the high plns (out to the W). As
is typical...the GFS/NAM look overly aggressive...but there
probably will be a small number of isolated storms that make it in
here during the evening/nighttime hrs. There`s always a chance
enough storms could form to grow upscale into an MCS that slides
into the CWA. Just not enough confidence to say much more.
&&
.AVIATION...(For the 00Z KGRI/KEAR TAFS through 00Z Tuesday)
Issued at 610 PM CDT Mon Aug 12 2019
VFR conditions with light winds are expected through this TAF
period.
Midlevel clouds will diminish this evening, leaving mostly clear
skies through most of the overnight. Then scattered and high
clouds are expected to move back in Tuesday morning.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...None.
KS...None.
&&
$$
SHORT TERM...Kelley
LONG TERM...Kelley
AVIATION...Mangels
Area Forecast Discussion
National Weather Service Goodland KS
445 PM MDT Mon Aug 12 2019
.SHORT TERM...(This evening through Tuesday)
Issued at 158 PM MDT Mon Aug 12 2019
Seeing subtle height rises today in mainly zonal flow aloft in the
wake of last nights shortwave trough. The ridge to the west will
amplify on Tuesday putting the central High Plains under more of a
northwest flow. Appears to be a weak impulse coming out of Wyoming
Tuesday afternoon and evening. At the surface, cold front has just
about cleared the forecast area this afternoon with northwest
winds behind it. Surface dew points have dropped slightly, but
still remain mostly in the 60s, with the exception of far western
areas where they drop off rapidly into the 40s and 50s. For
tonight, expecting quiet weather. Did include a mention of patchy
fog in south/western parts of the area where HRRR and RAP show
reduced visibilities towards 12z, possibly moisture pooling along
leading edge of return flow/frontal boundary stalled to the west.
On Tuesday, expecting scattered thunderstorms to develop in
northeast Colorado 19-21z as shortwave moves out of Wyoming and
near cyclonic surface convergence associated with mesolow which
develops in northeast Colorado. CAM ensemble mean shows a surface
based instability axis of up to 2000 j/kg extending from
northeast Colorado south/southeast along the Kansas-Colorado
border area. Surface to 500 mb shear is forecast to be around
30-40 kts. Due to weak forcing, storm coverage will be somewhat
limited, but those parameters suggest a few severe storms will be
possible as storms track down the instability axis, with large
hail and wind the primary hazards. Global models show QPF
bullseyes Tuesday evening up to 2 inches, so cant discount locally
heavy rainfall either.
Temperatures through the short term period will be near to
slightly below normal, with lows in the 60s and highs on Tuesday
in the mid to upper 80s.
.LONG TERM...(Wednesday through Monday)
Issued at 249 PM MDT Mon Aug 12 2019
Synopsis... Showers and thunderstorms may be possible Wednesday
through Friday, mainly in the afternoon and evening hours. Some
isolated severe weather may be possible. Drier conditions are
expected this weekend, but showers and thunderstorms may return to
the Central High Plains early next week. High temperatures will
increase from the mid to upper 80s Wednesday to the low 90s
Thursday through Monday. Low temperatures will similarly increase
from the mid 50s and low 60s Wednesday morning to the low to upper
60s this weekend.
Discussion... Biggest change from previous forecast for the long
term forecast period is that shower and thunderstorm chances have
been increased for Thursday and Friday in the afternoon and
evening hours. The increased chances for precipitation are
generally for the eastern portion of the forecast area east of US
Hwy 83. Not expecting widespread severe weather on either Thursday
or Friday. The reason for the change is that newer model guidance
is showing that the upper-level ridge over the southern United
States is taking longer to strengthen and lead to reduced
precipitation chances for the Tri-State area. At this point, some
moderately strong northwesterly upper-level flow will be possible
over the forecast area Thursday and Friday which could lead to
some isolated showers and thunderstorms.
There is a threat of severe weather Wednesday afternoon and
evening. Lingering convection from overnight Tuesday may disrupt
the thermodynamic support for thunderstorm formation later in the
day on Wednesday, but forecast models are still indicating the
possibility of 1500 to 2500 J/kg of CAPE as well as 40 to 50 kts
of deep layer wind shear over much of the Tri-State area during
that time frame. With a surface low developing on the lee side of
the Rocky Mountains in eastern Colorado, there may be some
enhanced surface convergence which would provide the initial
lifting mechanism for storms. Right now, current thinking is the
main threats are large hail and damaging winds, especially with
any discrete convection which may form. While later this week may
be drier, chances for showers and thunderstorms will likely return
Sunday night and Monday afternoon and evening as an upper-level
trough develops over the western United States.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 445 PM MDT Mon Aug 12 2019
KGLD, vfr conditions expected through the period. Winds at taf
issuance from the northeast under 10kts decreasing to 5kts or less
while veering to the east then northeast overnight. After 14z
winds become southeast under 10kts rising toward 12kts by late
afternoon. Fog/br possible in the 11z-13z timeframe and for now
have visibility down to 5sm but could be lower. After 23z
thunderstorms are anticipated near the terminal and could produce
strong winds and locally heavy rainfall producing sub vfr
cigs/vis. For now have VCTS to start things off.
KMCK, vfr conditions through the period. A north wind under 10kts
at taf issuance will become light and variable overnight then
establish an east or east-southeast direction under 10kts after
18z.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...024
LONG TERM...PATTON
AVIATION...99
Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
1023 PM EDT Mon Aug 12 2019
.SYNOPSIS...
Rainfall chances will slowly increase during the first half of the
week, peaking on Wednesday with a weak cold front and remaining
higher than normal into the weekend. Hot and humid conditions will
persist through mid week, with a cooling trend toward the end of the
week.
&&
.NEAR TERM /THROUGH TUESDAY/...
As of 1020 PM EDT: A few convection-allowing models, most notably
the recent HRRR runs, have isolated showers regenerating just east
of the southern Appalachians through the early morning hours.
However, this appears overdone given the ongoing stabilization and
general lack of overnight forcing. Thus, the rest of the night
should remain quiet with regard to precipitation, with mainly
mountain valley fog and low stratus making another appearance.
Otherwise, the upper ridge over the Southern Plains will continue to
build over the southeast thru the near-term, as troughing continues
to push off over the Atlantic. An upper shortwave crossing the Upper
Midwest tonight will move a sfc low toward the Great Lakes, with the
associated front working its way toward the OH Valley by the end of
the period. PoPs will ramp up most strongly near the end of the
period Tuesday afternoon. The combination of expected mid 90s
temperatures and low 70s dew points Tuesday afternoon has required
posting a Heat Advisory from Franklin County, GA southward.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
As of 145 PM EDT Monday: A slight increase in mean mid-lvl flow and
falling heights is expected Tuesday night. Within this regime,
organized gusty tstms should develop upstream of the cwfa. Deep
convection and/or it`s remnants may sag into the mountain Tuesday
evening. Otherwise, warm and muggy conditions will linger. The
bubble of the very warm and humid airmass will be displaced eastward
a tad on Wednesday, but middle 90s are still probable along and SE
of I-85 with another afternoon of heat index values in the lower
100s. The atmosphere as a whole remains moist on Wednesday and the
upper pattern broadly cyclonically curved. Based on this, ensemble
and blended model solutions blossom deep convective coverage to
numerous in the afternoon. PWAT plan view progs show a continental
airmass attempting to impinge upon the region but really makes only
a limited penetration into the NC mtns on Thursday. Therefore,
would not expect much deviation from climo pop as we return to
maximum temperatures closer to normal.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
As of 2 PM EDT Monday: Starting Thursday evening with the 500mb
pattern showing a broad trough over the East with axis from the
Great Lakes to FLorida and a elongated ridge over the SW. The
surface front by Friday will be becoming stationary from the NE Gulf
to the Carolina coast into early next week. Models continue to
depict some sort of low development along the front over the Gulf.
The GFS is a bit back and forth as to low development. The EC has a
low to form on Friday and lingers this low wobbling around the FL
Panhandle through the first half of next week. Perhaps there will be
better agreement later in the week as to what happens with this low
and how it will affect our weather. Keeping POPs at slight to low
chance with the current uncertainty. The GFS has a strong northern
stream shortwave crossing the Great Lakes on Sunday and bringing a
weak cold front to our region by late Monday. The EC delays the
arrival of the shortwave until at least Tuesday. May raise POPs a
bit for northern zones late Monday. Temperatures will be near or
slightly below normal.
&&
.AVIATION /03Z TUESDAY THROUGH SATURDAY/...
At KCLT and elsewhere: Showers and thunderstorms have dissipated
quickly this evening and conditions should remain dry overnight.
Confidence is fairly high in mountain river valley low stratus and
fog making an appearance since higher stratus is not really
indicated in profiles. Any low stratus east of the mountains is much
less certain, but with MOS hinting at some lower end MVFR stratus in
the Piedmont near KCLT. Will feature FEW010 there. Any thunder
chances ramp up slowly on Tuesday as a front gradually approaches
from the northwest. Will feature late day PROB30 for now, with the
earliest onset in the mountains around KAVL. Expect light and
variable winds to pick up from the southwest at less than 10 kt east
of the mountains, except NW at KAVL.
Outlook: Coverage of showers and thunderstorms will increase Tuesday
night into Wednesday as a cold front and associated moisture/forcing
arrive from the northwest. The boundary will stall southeast of the
area mid to late week, with lower end convective chances persisting.
Early fog/stratus will be possible each day across mountain valleys.
Confidence Table...
02-08Z 08-14Z 14-20Z 20-00Z
KCLT High 100% High 100% High 80% High 100%
KGSP High 100% High 100% High 100% High 100%
KAVL Low 55% Low 58% High 80% High 100%
KHKY High 100% High 95% High 100% High 100%
KGMU High 100% High 100% High 100% High 100%
KAND High 100% High 100% High 100% High 100%
The percentage reflects the number of guidance members agreeing
with the scheduled TAF issuance flight rule category. Complete hourly
experimental aviation forecast consistency tables and ensemble forecasts
are available at the following link:
www.weather.gov/gsp/aviation
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...Heat Advisory from noon to 8 PM EDT Tuesday for GAZ026-028-029.
NC...None.
SC...None.
&&
$$
SYNOPSIS...DEO
NEAR TERM...HG/JPT
SHORT TERM...CSH
LONG TERM...DEO
AVIATION...HG
AREA FORECAST DISCUSSION...UPDATED
National Weather Service Jackson KY
1106 PM EDT Mon Aug 12 2019
.UPDATE...
Issued at 1106 PM EDT MON AUG 12 2019
Clouds have redeveloped across the area this evening. Temperatures
currently range from the low to mid 70s across most locations.
Very deep convection has initiated across IL, close to the warm
front aligned from west to east. The latest model guidance
continues to suggest convection conglomerating more into an MCS
and moving into the I-64 corridor towards dawn. The latest
mesoanalysis page shows the better instability gradient stalling a
bit in the previous few hours. Still, a modest low level jet
should develop overnight, helping to advect in at least some
additional moisture/instability across eastern Kentucky. Given
the model agreement, have increased PoPs to likely along and north
of the I-64 corridor towards dawn. This complex should weaken as
it moves southeast into the morning hours, and have attempted to
reflect this in the grids, before additional convection refires in
the afternoon. The rest of the forecast remains on track. Updates
have been sent.
UPDATE Issued at 810 PM EDT MON AUG 12 2019
Higher clouds are diminishing across the Commonwealth through
early this evening. Given the trend, will allow for more of a mostly
clear first half of the night. Clouds will then increase out of
the northwest for the second half of the night, as convection
develops across the Ohio Valley and looks to threaten our area
closer to dawn. Based on the latest higher resolution model
guidance and trends in observations, did slow the higher PoPs down
a bit for now. Will re-evaluate PoPs later this evening. The rest
of the forecast is on target. Updates have been sent.
&&
.SHORT TERM...(This evening through Tuesday night)
Issued at 505 PM EDT MON AUG 12 2019
Late today an upper level ridge was over TX and the lower
Mississippi Valley, and largely zonal flow was over the northern
part of the CONUS. Within the flow there was a shortwave trough
embedded over the Midwest, with an associated surface low over IA.
Very hot and humid air was present under the ridge, with
temperatures in the 90s and dew points of 75-80 upstream from us
over AR and West TN. The shortwave and surface low will move east
during the short term period, passing to our north on Tuesday. Our
low level flow will increase tonight and Tuesday ahead of the
system`s cold front advancing toward us. This will advect hot and
humid air into the region. Although increasing clouds will
probably hold temperatures to near 90 (or possibly cooler) on
Tuesday, our dew points will likely climb to the mid 70s. A broad
upper trough will also be developing southward over the Ohio
Valley and Mid Atlantic region on Tuesday, bringing lower
geopotential heights and cooling in the mid/upper levels. This
combo will result in very unstable conditions, with CAPE likely to
reach 3-4K J/Kg. With a modest amount of shear expected as well,
severe thunderstorms will be a threat. Because of the very warm
atmosphere, wind is the primary concern. However, the large amount
of instability could also present a hail threat from the most
intense updrafts. This is all assuming convective development
occurs with peak heating. While soundings seem to support it, the
NAM and HRRR are looking very stingy, holding off main
development on Tuesday to an area along the cold front as it is
getting ready to exit our area to the south at the end of the day.
To varying extents, models also show nocturnal development
progressing east southeast across our area late tonight into
Tuesday morning in association with the shortwave and low level
advection/isentropic lift. This could obviously play a factor in
the evolution on Tuesday. All this said, it`s not a high
confidence forecast, and is a matter of presenting probabilities.
Whatever occurs, activity is expected to be on the decline from
northwest to southeast on Tuesday night, with most of it coming to
at least a temporary end by morning.
.LONG TERM...(Wednesday through Monday)
Issued at 401 PM EDT MON AUG 12 2019
There is good model agreement with the overall upper air pattern
forecast for the beginning of the forecast period, as troughing
continues to dominate the eastern U.S. with upper ridging centered
over the southwest U.S. This mean pattern will transition early next
week as the upper ridging over the southwest U.S. expands eastward
and the westerlies retreat north. There is some disagreement on how
quickly this occurs, with the GFS tending to be slower in the
evolution of the pattern and with the rising heights forecast for
our area this weekend. While timing differences exist, the overall
trend will be for warming temperatures as we move into the start of
next week.
At the surface a cold front will be southeast of the area by
Wednesday morning. A few lingering showers could still occur on
Wednesday before surface high pressure builds into the area for the
end of the week. Dry weather will then prevail into early next week,
though there will be a small chance for a few terrain induced
thunderstorms near the VA border Sunday afternoon. Temperatures will
be cooler in the wake of the cold front, but as surface high
pressure shifts east over the weekend temperatures will once again
be on the upswing. The 12Z GFS, which may be holding onto the
eastern U.S. troughing a little too long pushes another cold front
through the area late in the weekend or early next week. A more
likely scenario, which is supported by the ECMWF, is that the front
will stall in the OH Valley, not making it through eastern KY, and
then pull back north. In either case the front should make it close
enough to our area to bring a small chance of showers and
thunderstorms for Monday.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
ISSUED AT 810 PM EDT MON AUG 12 2019
VFR conditions will prevail through 06z. Clouds will then be on
the increase from the northwest between 06 and 12z, with the
potential of showers and thunderstorms threatening between 08 and
12z. KSYM would stand the best chance of seeing localized impacts,
but there is still some uncertainty regarding the intensity of the
convection as it moves in late, so will only include VCTS for now.
This convection will likely weaken as it moves southeast across
the area; however, additional convection, some of which could be
robust, will redevelop in the afternoon as a cold front
approaches the area after 16z. There still remains some timing
uncertainty with this, so will only mention a several hour window
of VCTS at all TAF sites at this point. Light winds overnight will
turn southwesterly at around 10 kts during the day on Tuesday,
with gusts of 15 to 20 kts at times during the afternoon hours.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GEOGERIAN
SHORT TERM...HAL
LONG TERM...SBH
AVIATION...GEOGERIAN
Area Forecast Discussion
National Weather Service North Platte NE
621 PM CDT Mon Aug 12 2019
.SHORT TERM...(This evening through Tuesday night)
Issued at 254 PM CDT Mon Aug 12 2019
Mainly dry conditions seen through the day will continue into the
night across most of the CWA. A shortwave trough is tracking along
the US/Canadian border just north of North Dakota this afternoon. A
weak disturbance associated with the trough will travel into eastern
South Dakota and northeastern Nebraska late this afternoon. The
models are in some disagreement with precipitation in our CWA,
however, the HRRR model continues to show very isolated showers
and thunderstorms across north central Nebraska. Bounced back and
forth with the thunderstorm chances across our north central
counties late this afternoon and evening, but since a stray shower
and thunderstorm cannot be completely ruled out, kept small PoP
chances across this area for this afternoon. Elsewhere, conditions
will remain dry through the remainder of the afternoon and into
the overnight hours. Seasonable temperatures are expected
overnight with lows in the 50s across western Nebraska and in the
low 60s across central Nebraska. On Tuesday, temperatures will be
slightly below seasonable normals with highs in the lower 80s
across the region. A surface boundary across northeastern Colorado
and southeastern Wyoming will interact with a disturbance by
Tuesday afternoon which will increase precipitation chances across
western Nebraska. Through the evening and overnight hours, any
storms that do develop will track towards the east across the CWA.
The greatest chance for strong thunderstorms at this time appears
to be confined to portions of southwestern Nebraska.
.LONG TERM...(Wednesday through Monday)
Issued at 254 PM CDT Mon Aug 12 2019
Precipitation...The aforementioned surface boundary will remain
anchored to the west of the CWA on Wednesday before shifting east
later in the week. This boundary will continue to bring thunderstorm
chances to the area through the end of the week as it shifts east
and transitions out of the area. The best chances for widespread
precipitation will be on Wednesday and Thursday from west to east.
By Friday, precipitation chances begin to decrease, with the
exception of some light PoPs across portions of northern Nebraska
Friday evening, as high pressure begins to build back into the
southern plains.
Temperatures...Wednesday will be the coolest day of the week with
high temperatures generally in the 70s across the area, which is
around 5 to 10 degrees below seasonable normals. Temperatures will
begin to increase from the southwest starting on Thursday. By the
weekend, temperatures will return to the upper 80s to lower 90s in
response to the aforementioned high pressure building over the
southern plains.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 620 PM CDT Mon Aug 12 2019
Skies becoming clear this evening, followed by increasing clouds
later tonight into Tuesday. Indications a few showers possible
Tuesday morning across the western Sandhills, which could affect
the KLBF terminal after 19Z. Introduced a tempo for -TSRA 20Z-
24Z. At KVTN, some increase in clouds Tuesday with VFR conditions
expected.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SHORT TERM...Thorne
LONG TERM...Thorne
AVIATION...Roberg
Area Forecast Discussion
National Weather Service Marquette MI
730 PM EDT Mon Aug 12 2019
.SHORT TERM...(This evening through Tuesday)
Issued at 354 PM EDT MON AUG 12 2019
Water vapor loop and RAP analysis shows a quasi-zonal flow across
the Upper Great Lakes and models indicate this will remain over the
next 24 hours. A weak shortwave noted moving through MN and
western/southern WI was supporting light to moderate showers across
much of MN into nw and southern WI this afternoon. General confluent
flow aloft and sfc ridging into the area from high over Saskatchewan
has kept conditions dry across the U.P. thus far today, although
there is plenty of cu around with inland sfc dewpoints well into the
50s and 0-3 km lapse rates around 7C. Temps this afternoon despite
clouds and the development of lake breezes have reached well into
the 70s, except for 60s readings near the Lake Superior shore.
Model soundings indicate there could be some weak instability along
the WI border to support an isolated shra into early evening, but
otherwise dry conditions are expected with cu likely dissipating
after sunset but some high clouds could remain through the night.
More prominent shortwave trough over the western Dakotas will slowly
be approaching the region late tonight into Tue, so there could be
an increase in weak forcing late tonight into Tue for some isolated
shower activity, but again model trends suggest best chance for an
isolated shower would be along the WI border as better forcing with
shortwave stays south of area. Plenty of daytime cu is expected
again on Tue.
Expect min temps tonight generally falling into the lower 50s with
even a few upper 40s readings at typical inland cold spots. Readings
near the Great Lakes will be in the mid to upper 50s. Highs Tue will
again be in the 70s with cooler 60s readings near Lake Superior
shore in prevailing ne flow across area ahead of building sfc high
pressure from nw.
.LONG TERM...(Tuesday night through Monday)
Issued at 327 PM EDT MON AUG 12 2019
Quiet weather looks to prevail through Thursday, with a gradual warm
up expected through the end of the week and throughout the weekend.
With the warm up, increasing humidity levels and chance for
precipitation will return.
As high pressure remains in control over the Upper Peninsula through
Thursday, the weather is expected to remain fairly quiet. Tuesday
night into early Wednesday there could be an isolated shower or two
that works into southern parts of Upper Michigan as an inverted-
trough digs south across Minnesota and Wisconsin. Otherwise,
Wednesday and Thursday are shaping up to be beautiful days!
Friday, high pressure shifts off to our southeast and a trough
upstream of the region starts to drop towards the Upper Great Lakes.
This will allow the pressure gradient to strengthen across the area
with winds becoming southwesterly. This south-southwest flow will
begin to bump in additional moisture back into the region, bringing
back chances for showers and thunderstorms.
Over the upcoming weekend, the upper-level pattern becomes
increasingly amplified as a lead shortwave lifts northeast across the
Upper Great Lakes, followed by the main shortwave tracking eastward
across across the region later on. Therefore, we likely will be
looking at multiple rounds of showers/storms Friday night through
early Sunday morning. Models are still a bit inconsistent with the
timing/placement, so overall confidence is low in regards to where
and when the best chances for precipitation will be over the
weekend. Given the warm, moist advection pattern, coupled with
mid/upper level lift, this will support a period of active weather.
MUCAPEs do not get terribly impressive over the weekend, but
depending on the magnitude of the moisture transport and PWATs there
certainly may be heavy rain that accompanies any thunderstorm
activity. During the latter half of the weekend into early next
week, the secondary, stronger shortwave will push east of the region
putting us briefly under a stint of cold air advection and drier
conditions.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 730 PM EDT MON AUG 12 2019
VFR conditions are likely to prevail thru this fcst period at
KIWD/KCMX/KSAW. -SHRA may occasionally occur at KIWD thru Tue
morning, but probably not much more than sprinkles this evening. Not
out of the question that a -shra or sprinkles could occur at KCMX
this evening. Winds will be under 10kt thru the period.
&&
.MARINE...(For the 4 PM Lake Superior forecast issuance)
Issued at 354 PM EDT MON AUG 12 2019
Winds over the lake are expecteds to stay at or below 20 knots for
the entire forecast period.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
None.
Lake Michigan...
None.
&&
$$
SHORT TERM...Voss
LONG TERM...Ritzman
AVIATION...Rolfson
MARINE...Voss
Area Forecast Discussion
National Weather Service Pueblo CO
803 PM MDT Mon Aug 12 2019
.UPDATE...
Issued at 800 PM MDT Mon Aug 12 2019
HRRR indicating some convection may fire in the next hour or so from
the greater Canon City area ESE down towards Colorado City.
Likewise have bumped up POPs this area for this evening.
HRRR also showing it could be a rather busy day tomorrow on the
far eastern plains as a few supercells moving south-Southeast are
being indicated in the 00 UTC run. /Hodanish
&&
.SHORT TERM...(This evening through Tuesday)
Issued at 245 PM MDT Mon Aug 12 2019
Drier air has moved into the area today and only a few showers and
thunderstorms have developed over and near the higher terrain. The
I-25 corridor and westward will continue ot be the most favored area
for thunderstorms development through this evening. However, there
is still the possibility of a few storms developing/moving across
the southeast corner of the state. Most, if not all storms end by
about midnight.
Tue the upper ridge will be centered over NM, and moisture will
again be limited over southern CO. However, there will still be
enough moisture and instability for some showers and thunderstorms
to develop over and near the mtns. Tue afternoon, a disturbance
moving out of WY and across northeast CO, could bring some
thunderstorms into Kiowa county, but the forecast models are
currently keeping the storm activity north of Kiowa county until
after 00Z. Temps on Tue should reach highs in the upper 80s and
lower 90s over the plains, with upper 80s and lower 80s in the high
valleys.
.LONG TERM...(Tuesday night through Monday)
Issued at 245 PM MDT Mon Aug 12 2019
A flat ridge remains centered over Texas/Arizona/New Mexico/northern
Mexico through much of the extended forecast period, leaving
generally weak and undisturbed westerly to west-northwesterly flow
over Colorado. TPW over the high terrain will run 50%-75% of normal,
limiting convective potential somewhat, especially when compared
to this past weekend and last week. Still, given strong afternoon
heating, expect isolated to scattered storms to develop each
afternoon over the mountains, with very isolated activity
spreading to the valleys and I-25 corridor along outflow
boundaries. The main threat with storms each day will be cloud to
ground lightning, with flash flooding a slight possibility should
one of the few slow-moving storms move over a burn scar. Gusty
winds and small hail could be possible with a couple of storms,
but weak shear and marginal instability will limit the threat.
Now for some specific deviations from that discussed above. Tuesday
night, a shortwave pushing east across the northern plains will have
sent a cold front down the central plains. Models continually
produce a south-moving MCS along the CO/KS border, fueled by moist
southerly flow. Given this system will move through overnight, the
main threats will be gusty winds, heavy rainfall, and cloud to
ground lightning. It appears as though the main areas impacted will
be Kiowa, Prowers, Bent, and Baca Counties. A similar setup is
plausible Wednesday night, with the MCS likely slightly further
east, just clipping the CO/KS border. On Friday and Saturday, the
ridge flattens further as a series of shortwaves move across the
northern Rockies, potentially enhancing shower and thunderstorm
development over the plains those afternoons and early evenings,
depending on the southward extend of the waves and outflow
activity from northern storms. Models build the ridge back over
Colorado Sunday and Monday, limiting the majority of precipitation
to the mountains once again.
Afternoon temperatures during the extended period will remain
above normal, with highs spanning the 90s across the plains, near
90 in Colorado Springs, and 80s across much of the high valleys.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 245 PM MDT Mon Aug 12 2019
KCOS, KALS, KPUB could see showers/tstms in the vicinity this
evening, and then again during the afternoon and evening on Tue. The
main storm threats will be lightning, gusty outflow winds and
brief locally heavy rain.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...HODANISH
SHORT TERM...28
LONG TERM...LINE
AVIATION...28