Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 08/01/17
Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
639 PM CDT Mon Jul 31 2017
.UPDATE...
Issued at 633 PM CDT Mon Jul 31 2017
No major changes planned to the forecast as a front and some
associated convection continues to march south and southeast
toward the ABR cwa. The most likely area to see some showers and
thunderstorms over the next few hours will be across north central
SD. Activity is expected to fizzle out by late evening.
&&
.SHORT TERM...(This Evening through Tuesday Afternoon)
Issued at 313 PM CDT Mon Jul 31 2017
Starting to see convection fire up along the cold front as it
advances southward across ND and into extreme northwest SD. The
operational HRRR is doing a great job handling the development this
afternoon. It had nailed the initial updrafts/convection across far
northwest SD, then showed about an hour later what is currently
ongoing in southwest ND. Will therefore follow the HRRR pretty
closely in regards to additional development/movement of activity
over the next several hours. HRRR is showing additional development
over northeast ND in the next hour or so where there is currently a
cumulus field building. Then, there should be some degree of filling
in along the cold front as it moves south. Just how much of it fills
in is the question. Have adjusted POPs a bit to match current
thinking, but may go back shortly and make further adjustments
towards the HRRR/CONSShort POPs. Moderate instability exists ahead
of the front, with an area of steeper lapse rates out ahead as well.
Shear is the main hindrance though. All that said, expect to see a
few strong to perhaps severe storms along this front as it drops
south, perhaps affecting north central SD in the next few hours.
Otherwise, this activity is expected to wane as the sun sets and we
see the loss of daytime heating.
For Tuesday, front continues to slowly advance southward, with
additional shower and thunderstorm activity possible - mainly for
southern areas in the CWA. Have a feeling some of the low end POPs
Tuesday morning may be overdone a bit, with many locations staying
dry. May have to wait for the afternoon hours to see any more
scattered development of storms.
.LONG TERM...(Tuesday Evening through Monday)
Issued at 313 PM CDT Mon Jul 31 2017
Models are gaining consistency and consensus with the potent
shortwave expected to track southeast across the northern plains on
Wednesday. Still some difference in the surface features/mesoscale
details between models, but more and more they are indicating the
potential for a somewhat widespread precipitation event across the
CWA. Can`t rule out a few stronger storms, but severe potential is
low at this time due to lack of instability. High temperatures on
Wednesday may only rise to the mid 70s to low 80s, and that may even
be on the warm side if cloud cover moves in quickly Wednesday
afternoon. Still plenty of shear, both 0-6km and 0-1km, so will have
to see how the system progresses.
Cool air will then spread in the region behind the Wednesday system.
High temperatures on Thursday and Friday will likely be 10 to 15
degrees below normal. Should see a very gradual warm up and
temperatures should be nearing seasonal values by the weekend. The
next best shot at precipitation looks to be associated with another
shortwave in the Saturday time frame, but details on that system are
unclear at this point.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday Evening)
Issued at 633 PM CDT Mon Jul 31 2017
VFR conditions are expected to prevail through the period. Some
showers and thunderstorms may impact KMBG this evening as a front
marches southeast out of ND. Storms should fizzle out by 6z.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...None.
MN...None.
&&
$$
UPDATE...Wise
SHORT TERM...TMT
LONG TERM...Serr
AVIATION...Wise
Area Forecast Discussion
National Weather Service Hastings NE
945 PM CDT Mon Jul 31 2017
.UPDATE...
Issued at 941 PM CDT Mon Jul 31 2017
Made a couple changes to the forecast for the rest of tonight.
Short term/hires models are in pretty good agreement showing
little in the way of any precipitation, pulled PoPs across the
north/northeastern portions of the CWA. There`s also some hint at
the potential for some light fog across the west and southern
portions, so did insert a patchy mention for around sunrise.
Otherwise only minor tweaks were made.
&&
.SHORT TERM...(This evening through Tuesday)
Issued at 327 PM CDT Mon Jul 31 2017
There have been persistent showers in north central Kansas through
the afternoon. Otherwise, the showers have ended in central Nebraska
and there are some breaks in the clouds this afternoon.
Most of the models continue to bring some showers and thunderstorms
into the northeast part of the forecast area this afternoon, but the
HRRR has pushed it back until later this evening. Have kept some low
PoPs in the north/northeast part of the forecast area, and have kept
them later into the night. The next upper level wave moves into the
area on Tuesday and there will be some small chances for showers and
thunderstorms, mainly in the Nebraska portion of the area.
Temperatures will be similar to today.
.LONG TERM...(Tuesday night through Monday)
Issued at 327 PM CDT Mon Jul 31 2017
The weak flow continues Tuesday night and there is a chance for some
showers and thunderstorms, across the Nebraska portion of the area.
By Wednesday an upper level low is developing in the northern Plains
and a cold front is developing across the Dakotas. This system will
affect the area mainly Wednesday night into Thursday. This will be
the best chance for showers and thunderstorms and a few of them
could be strong to severe.
After the upper low moves to the east, there will be northwest flow
across the area for the remainder of the period. There will be
cooler temperatures Thursday into Friday as a surface high builds
into the area and there should be dry conditions. The northwest flow
will have a few waves that move through Saturday through Monday and
there are some on and off chances for thunderstorms.
&&
.AVIATION...(For the 00Z KGRI/KEAR TAFS through 00Z Tuesday)
Issued at 620 PM CDT Mon Jul 31 2017
VFR conditions are currently in the forecast for this TAF period.
Similar to the past few nights, there is a small chance for
scattered precipitation around the area, but with confidence in
any timing/location being so low, kept any mention out. Winds
tonight will be light/variable, some models/guidance suggest the
potential for some light fog around in the early morning hours, so
do have a 6sm mention. Will see how upcoming models evolve before
inserting anything lower.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...None.
KS...None.
&&
$$
UPDATE...ADP
SHORT TERM...JCB
LONG TERM...JCB
AVIATION...ADP
Area Forecast Discussion
National Weather Service Houston/Galveston TX
855 PM CDT Mon Jul 31 2017
.DISCUSSION...
The seabreeze moved inland of the I-10 corridor earlier this
evening. There have been a few isolated showers between 20 and 60
nm of Galveston through the first part of the evening. The Texas
Tech and HRRR both support at least isolated showers moving within
20 nm of the coast west of Freeport and tweaked the rain chances a
bit to account for this. Otherwise, the forecast is on track.
40
&&
.PREV DISCUSSION... /ISSUED 626 PM CDT Mon Jul 31 2017/
AVIATION.../00Z TAF/
Visible satellite and radar show sea breeze working inland but
not sure how far it will reach. Quite possible that winds at
KHOU/KIAH could turn more to the E or SE with its passing instead
of NE. Winds should decouple tonight and be calm for most
terminals. Oddly enough for the start of August, dewpoints may be
low enough that fog should not develop except for maybe CXO and
that is a small chance. Moisture should return tomorrow into
Wednesday. There might be a few showers tomorrow afternoon but
think best convective probabilities will be Wednesday through the
end of the week. Next chances for more widespread MVFR conditions
will be for the end of the week with any TSRA.
Overpeck
PREV DISCUSSION... /ISSUED 354 PM CDT Mon Jul 31 2017/
DISCUSSION...
Save for a few isolated showers across the offshore waters, most
of the region is dry (and feels noticeably cooler with 3 PM CDT
heat index values in the low to mid 90s) behind yesterday`s slow
moving front as drier air has settled into the region. This drier
air will be gradually replaced by returning Gulf moisture tonight
through Tuesday night as light offshore winds gradually become
onshore. As a result, isolated to scattered showers will remain
possible across the coastal waters tonight and Tuesday. Rain
chances for Southeast Texas Tuesday will be largely dependent on
how quickly this moisture pushes back inland, with coastal
counties having the main chances for rain Tuesday afternoon and
evening (20-40 PoPs... and even then 30-40s may be generous with
questions about the aforementioned moisture return given weak low
level flow). Otherwise, expect overnight lows in the 70s to low
80s to warm into the upper 80s to mid 90s by Tuesday afternoon.
Afternoon water vapor imagery shows a shortwave trough dropping
across South Dakota/Nebraska. This feature will continue to swing
into the Southern Plains on Tuesday, reaching Southeast Texas on
Wednesday and allowing northwest flow aloft to become established.
Coastal convergence will result in another round of coastal
showers and possibly a thunderstorm Tuesday night with diurnal
destabilization, lift from the shortwave, and ample Gulf moisture
(forecast precipitable water values 1.8-2 inches), allowing
scattered to numerous showers and thunderstorms to spread inland
on Wednesday. Given the amount of moisture present, cannot rule
out brief heavy rainfall but forecast storm motions around 20 MPH
and widespread rainfall deficits observed this month (areas west
and south of the Houston metro experiencing deficits roughly 1 to
3 inches below normal for July) should mitigate against any
flooding concerns outside of urbanized areas.
The remainder of the long term portion of the forecast will
follow a fairly similar pattern, with overnight marine convection
shifting inland with daytime heating. Enhanced coverage will be
possible as disturbances embedded in the flow aloft translate
across the region and, given the difficulty timing or pinpointing
these smaller waves this far out, have continued to advertise
scattered showers and thunderstorms (30-50 PoPs) through the end
of the week. With precipitable water values hovering near 2
inches, cannot rule out brief heavy rainfall with stronger
convection.
Another cold front looks to approach Texas this weekend as a
shortwave trough dives across the Great Lakes from Canada, but
with as quickly east as the wave moves have little confidence that
the front will push too far south into Texas. This would keep
deeper moisture in place across the region and allow for scattered
rain chances to continue through the upcoming weekend. Cloud
cover and rain should help keep temperatures near to slightly
below normal through the long term portion of the forecast, with
highs in the mid 80s to mid 90s and lows in the mid 70s to low
80s.
Huffman
MARINE...
Light to moderate NE winds are will begin veering through
tonight, become easterly by tomorrow, and continue on towards
becoming light and southeasterly by Wednesday. The second half of
the week will feature a number of weak upper disturbances that
will stretch chances for showers and thunderstorms across multiple
days. This may culminate in another summer cold front at the very
end of the week. At this time, the expectation for such a front
would be only to veer winds towards southwesterly for a time, but
a deeper push by the front could result in a more significant wind
change.
Luchs
&&
.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL) 74 95 75 91 74 / 0 10 20 40 30
Houston (IAH) 76 93 77 89 76 / 0 20 20 60 40
Galveston (GLS) 81 88 80 87 80 / 20 40 30 50 50
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
Discussion...40
Aviation/Marine...39
AREA FORECAST DISCUSSION...UPDATED
National Weather Service Jackson KY
1109 PM EDT Mon Jul 31 2017
.UPDATE...
Issued at 1058 PM EDT MON JUL 31 2017
Some high clouds are moving across the region which should not
limit radiational cooling little. Following warmer temperatures
and higher dewpoints this afternoon, low should be a couple of
degrees milder than this morning. The ongoing forecast had this
handled well, and hourly grids have been freshened up based on
recent observations.
UPDATE Issued at 803 PM EDT MON JUL 31 2017
Hourly grids have been freshened up based on recent observations
and satellite imagery. High pressure remains in control over the
region and no substantial changes were needed at this time.
&&
.SHORT TERM...(This evening through Tuesday night)
Issued at 410 PM EDT MON JUL 31 2017
19z sfc analysis shows high pressure in place over the Ohio
Valley. This has provided another quiet and fairly normal mid-
summer day, though temperatures are up along with a return of
moisture. Skies were mostly sunny through the day with some light
build up in cu during the afternoon and a layer of thin high
clouds drifting over the region. Readings are running in the low
to mid 80s most places with dewpoints varying from the mid 50s,
where some drier air had mixed down, to the stickier mid 60s
elsewhere. Meanwhile winds were light - generally out of the east
northeast. Not far away, though, a few showers did manage to show
up on our, recently returned to service, radar over western West
Virginia.
The models are in good agreement aloft through the short term
portion of the forecast. They all depict a pattern change of sorts
as a cluster of energy with a shortwave slips southeast into the
area tonight lowering heights. A relative weakness in the height
field will then hang around over the Ohio Valley through Tuesday
and into Wednesday morning. A fair amount of energy will pass
through during this time but none of it very consolidated. Given
the model agreement will favor a blended solution, though the
small scale features warrants particular attention to the higher
resolution NAM12 and HRRR for details.
Sensible weather will feature another similar night, but a bit
milder with mostly clear to partly cloudy conditions and some late
night patchy fog in the river valleys. For Tuesday, have included
some small PoPs for afternoon shower and thunderstorm chances over
the higher terrain in the southeast with the diurnal heating of
the day and no real triggers to key in on. Tuesday night will be
similar to the last few with lower clouds fading out in the
evening and temperatures a notch warmer, but still some river
valley fog around towards dawn.
Again used the CONSShort as a starting point for all the grids
through Wednesday morning with some point and terrain based
adjustments to temps tonight and Tuesday night. Also kept PoPs to
a minimum through the period, except for Tuesday afternoon in the
far southeast, in line with guidance.
.LONG TERM...(Wednesday through Monday)
Issued at 359 PM EDT MON JUL 31 2017
Longwave troughing will be the main story throughout the extended
portion of the forecast, encompassing much of the eastern conus,
including the Ohio Valley. A couple of secondary shortwaves will
travel through this longwave trough, the first one passing through
the state to start the period Wednesday. The second will develop
into a closed low as it makes its way SE into the Dakotas and
Minnesota during the day Thursday. This closed low will then shift
into the Upper Great Lakes region during the day Friday, deepening
heights further across Kentucky, before lifting back northward
into Canada and losing strength into the weekend. Longwave
troughing will still remain intact to finish out the period, with
another possible shortwave affecting the region during the day
Monday. Models are not in as good agreement about this feature
this late in the forecast however.
As for sensible weather, surface high pressure across much of the
region will remain intact for the day Wednesday. However it will
be far enough east of the region that light return SW flow will
begin to set in, and allow a bit warmer/moist air to advect into
the region. Temperatures are expected to make it into the mid 80s
for highs by the afternoon with slightly increasing humidity from
the day before. With the shortwave moving through in the upper
levels, this added moisture could interact to produce mainly
afternoon scattered showers and thunderstorms. Instability should
wane as we head into the overnight, so dropped thunder chances
generally after 6Z at night.
Much of the same is expected for Thursday as well, with isolated
to scattered convection expected in the afternoon, highs in the
80s, and more humid air continuing to advect in. The main
player on Thursday however will be a surface low pressure system
and associated frontal features that will begin to shift towards
the region from the NW during the day. This surface low will
continue to push NE in conjunction with the upper level flow, as
it continues to strengthen. The connected cold front will then
sweep eastward, traversing KY from west to east, starting in the
west Thursday night and exiting east of the sate Friday night.
Expect showers and thunderstorms to be on the increase throughout
the day Friday as the frontal system nears, and deep warm/moist
flow is in place. Instability as well as wind speed shear and
Pwats all look good during the day Friday, so can`t rule out some
scattered strong to severe storms during the afternoon. Will
continue to get a better handle on the event over the next couple
of days. Once the front passes through, winds will shift to a more
NW direction and allow drier air to take hold. This will cut off
best convective potential, though a few lingering storms will
still be possible into the overnight along the frontal lines.
Lingering rain may persist into Saturday, mainly in the high
terrain where upslope flow will have some influence, in addition
to the frontal boundary getting held up a bit over the high
terrain to our east.
Otherwise, Saturday and Sunday look to be quite pleasant, with
another cool and dry airmass taking hold from the north, much like
this previous weekend. Highs will be in the upper 70s on Saturday,
and in the low 80s on Sunday, with lower humidity values. The
unresolved possible shortwave on Monday could lead to another
round of scattered activity during the day to finish out the
forecast period, with temps in the low to mid 80s.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
ISSUED AT 807 PM EDT MON JUL 31 2017
With high pressure still remaining the primary player for our
weather through the TAF period, mainly VFR conditions are
expected. Some patchy dense fog is again expected in the river
valleys which should dissipate by 13Z to 14Z, but TAF sites
should not be affected. Otherwise high and perhaps a few mid
clouds will pass by from time to time with diurnally driven
cumulus field from 16Z. Winds will be light through the period.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JP
SHORT TERM...GREIF
LONG TERM...JMW
AVIATION...JP
Area Forecast Discussion...UPDATED
National Weather Service North Platte NE
627 PM CDT Mon Jul 31 2017
.SYNOPSIS...
Issued at 313 PM CDT Mon Jul 31 2017
H5 analysis from this morning had an elongated area of
high pressure extending from west Texas into southern Oregon. A low
amplitude ridge extended north of Oregon into swrn Canada, however
this ridge had flattened significantly from the 12z analysis from
Sunday. Across the central and northern plains, a tandem of
shortwaves were noted, one over swrn Kansas and a second over sern
South Dakota. These two disturbances had led to clouds and rain over
Kansas, as well as portions of eastern Nebraska earlier this
morning. Clouds remained across Kansas and eastern Nebraska this
afternoon with mainly clear skies in western Nebraska. At the
surface, low pressure was located over central South Dakota with a
surface trough of low pressure extending south, roughly along a line
from east of Ainsworth, to just west of Broken Bow, to southeast of
North Platte. Temperatures as of 2 PM CDT ranged from 81 at O`Neill
to 89 at Valentine.
&&
.SHORT TERM...(This evening through Tuesday)
Issued at 313 PM CDT Mon Jul 31 2017
Tonight and Tuesday...Over the next 24 hours,
precipitation chances will be the main forecast concerns. For late
this afternoon into tonight: Upstream of the two shortwaves
mentioned in the Synopsis, H5 hts are forecast to rise 10 to 30
meters this afternoon. No surprise, the latest NAM12 solution is
indicating some convective inhibition extending from the
northeastern Nebraska panhandle north into western and north central
South Dakota. further south and east, little or no cap exists which
would favor convective development by mid afternoon. However, SB
CAPES are much lower this afternoon compared to Sunday afternoon`s.
Shear this afternoon is weaker as well, especially where the
convective initiation is favored over north central Nebraska. That
being said, will leave in a mention of isolated thunderstorms late
this afternoon across north central Nebraska. The threat for
thunderstorms will gradually shift south and east into the early
evening hours before ending overnight in the east thanks to limited
shear and no low level jet. On Tuesday, a weak upper level
disturbance will track across western South Dakota, approaching
northwestern Nebraska Tuesday afternoon. By mid afternoon Tuesday,
the cap will weaken leading to thunderstorm development over
northern Nebraska. Wind shear continues to be marginal Tuesday with
sfc to 6km shear of 10 to 15 KTS, so any severe threat will be
limited to heavy rain and the threat for gusty winds.
.LONG TERM...(Tuesday night through Monday)
Issued at 313 PM CDT Mon Jul 31 2017
Tuesday night through Wednesday night...Convection will
drift south Tuesday evening an is expected to dissipate by late
evening, due to weak shear and the absence of a low level jet.
Shifting to Wednesday, a stronger upper level wave, will force a
cold front through the forecast area Wednesday night. This will lead
to the best chances for organized precipitation across the forecast
area during the forecast period. Convection will develop INVOF the
front which is progged to be focused along the SD/NE border by 00z
Thursday. This activity will track along with the front`s southward
progress Weds evening, and will persist into the overnight hours
thanks to a nice 30 KT low level jet, nosing into swrn Nebraska.
Thursday through Monday...Behind the exiting cold front Thursday,
much cooler temperatures are expected, as highs will struggle to
reach the middle 70s. Cool and dry conditions will carry over into
Friday with highs once again in the 70s. Thunderstorm chances will
begin to increase Friday night as a warm front pushes east of the
panhandle. At the same time, an upper level disturbance will ride
south from western South Dakota into northern Nebraska. Thunderstorm
chances will linger into Sunday as the frontal boundary will move
little through the weekend. Drier conditions will set in for Monday
as a strong disturbance forces the front well south of the area by
Monday morning.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 627 PM CDT Mon Jul 31 2017
The SREF, NAM and RAP models indicate patchy fog toward morning.
Dry air is moving in aloft and this should promote the necessary
radiation condition for the fog. Otherwise VFR is expected.
Isolated showers and thunderstorms this evening should dissipate
by 03z.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SYNOPSIS...Buttler
SHORT TERM...Buttler
LONG TERM...Buttler
AVIATION...CDC
Area Forecast Discussion
National Weather Service Omaha/Valley NE
624 PM CDT Mon Jul 31 2017
.SHORT TERM...(Tonight through Thursday)
Issued at 305 PM CDT Mon Jul 31 2017
Rain chances and temperatures will provide the primary forecast
challenges in the short term.
The large scale pattern features a 500 mb anticyclone that is
centered over the OR/NV/ID border area, with another high over
west TX. A fairly impressive shortwave trough was tracking across
western Ontario Canada. Our area was in weak northwest flow, with
a weak closed low dropping southeast across northern IA according
to recent water vapor satellite imagery. A trough extends back to
the southwest from that low into NE. Forcing for precipitation
will generally be weak tonight, but based on some of the
convection allowing models, will have to have at least some slight
chance POPs for tonight for parts of the area. Recent runs of the
experimental HRRR that chances will be best in our west and
northern counties until after midnight, then chances spread from
north to south overnight. Again, activity if any looks to be
fairly isolated. Look for lows tonight fairly close to MOS
guidance, around 60 to 65. Locations that have clear skies the
longest should be the coolest.
On Tuesday, a weak front should push down across the Dakotas and
MN. Some showers and storms appear possible along that front, into
parts of northeast NE by mid to late afternoon. Airmass ahead of
that front should warm a bit, and have highs on Tuesday a few
degrees warmer than today. Activity that develops would like
track/develop southeast through the evening and overnight.
Timing of a push of cooler air Wednesday and Wednesday night and
possible storms with that is somewhat in question. Will have POPs
into northeast NE Wednesday afternoon, but chance look better for
most of the forecast area for Wednesday night. Large scale forcing
will be stronger to our north/northeast as a mid level trough digs
over MN and WI, but we should see some scattered precipitation.
Current model timing suggests that Thursday will be mainly dry
(after a few showers possible in the morning for southeast NE and
southwest IA) and on the cool side as a ridge of high pressure at
the surface builds over the northern part of the Plains.
.LONG TERM...(Thursday night through Monday)
Issued at 305 PM CDT Mon Jul 31 2017
Mid level ridge will be over the far western US by Thursday night,
with a closed low near the MN/WI border and modest northwest flow
over our area. The ridge in the west should weaken, while a
broader trough from Hudson Bay back southwest toward the central
part of the Plains by Saturday/Sunday. This will continue to bring
in a cooler than normal airmass into our area. Chances for
precipitation should be highest from late Friday night into
Saturday night.
It seems that a cooler than normal pattern may continue into the
8 to 14 day period.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 619 PM CDT Mon Jul 31 2017
VFR conditions through the period with sct-bkn mid clouds
fl050-100. There is a 20% chance that thunderstorms could develop
near KOFK Tuesday...however the probability is too low to include
TAF at this time. Some patchy fog may try to develop Tuesday
morning. Not sure if it will occur at the TAF sites...so will
leave mention out at this time.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...None.
IA...None.
&&
$$
SHORT TERM...Miller
LONG TERM...Miller
AVIATION...Zapotocny
Area Forecast Discussion
National Weather Service Norman OK
644 PM CDT Mon Jul 31 2017
.DISCUSSION...
00Z TAFs.
&&
.AVIATION...
We will see some areas of showers and perhaps a thunderstorm,
especially in the west. There will likely be areas of MVFR
ceilings overnight and Tuesday morning as well.
&&
.PREV DISCUSSION... /issued 251 PM CDT Mon Jul 31 2017/
DISCUSSION...
Yesterday`s upswing in convection across the High Plains resulted
in a few MCVs drifting eastward today. This has complicated the
surface flow pattern. Furthermore, several days of convective
overturning has resulted in poor mid-level lapse rates across the
area. These convective-scale modifications have resulted in a
challenging forecast with regards to coverage and timing of
convection through the night.
Subtle ascent on 305-310k potential temperature surfaces that were
very moist resulted in some showers this morning in northwest and
north-central Oklahoma. These moved east and maintained throughout
the day bringing up to a hundredth of an inch at many locations in
northern Oklahoma. Latest radar mosaic shows a notable absence of
surface based convection. The only thunderstorms that have
developed as a result of diurnal destabilization have been over
the eastern Texas Panhandle. These are slowly moving eastward and
may begin to impact west-central Oklahoma by late afternoon.
Modified RAP soundings from northwest Oklahoma down toward western
north Texas all yield very weak MLCAPE <1,000 J/kg with skinny
CAPE profiles suggestion robust convection is unlikely.
Typically in these environments with nearly moist adiabatic lapse
rates at best, and pockets of subsidence and depleted low-level
moisture from convective overturning, we would be quick to scale
back precipitation probabilities significantly. In this case, mid-
level height falls from transient shortwave trough may provide
enough forcing for some convection tonight. Attendant steepening
of mid-level lapse rates is subtle and still results in meager
instability at best, so widespread significant convection isn`t
expected. Thus, we have lowered probabilities some tonight.
Until aforementioned mid-upper wave departs tomorrow and deep
moisture is pushed southward, convection remains a possibility.
The greatest concentration tomorrow should be across roughly the
southern half of the area. Lingering showers are possible near the
Red River Wednesday. Another wave in mean northwesterly flow will
force a cold front south bringing cooler weather Thursday night
into Friday, possibly preceded by sufficient forcing for some
convection late Thursday. Rain chances were trended up Sunday into
Monday based on a trend toward medium range guidance showing a
little stronger flow aloft as the pattern deamplifies some.
BRB
&&
.PRELIMINARY POINT TEMPS/POPS...
Oklahoma City OK 69 82 67 87 / 30 40 10 10
Hobart OK 70 81 67 88 / 50 50 10 10
Wichita Falls TX 71 81 69 88 / 30 50 30 20
Gage OK 65 82 63 87 / 40 40 10 10
Ponca City OK 68 86 67 89 / 30 30 10 10
Durant OK 69 83 68 86 / 20 30 20 20
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...None.
TX...None.
&&
$$
99/99/01
Area Forecast Discussion
National Weather Service Mount Holly NJ
927 PM EDT Mon Jul 31 2017
.SYNOPSIS...
High pressure over the Ohio Valley will drift south to the Carolinas
by Thursday. Meanwhile, a weak front should edge down into northern
sections of Pennsylvania and New Jersey Tuesday night and slowly dissipate
by late Thursday. The remains of Emily over Florida are destined
for a passage well to the east of the Carolinas during mid week.
A cold front will approach our area from the west on Friday and
move through the mid Atlantic states on Saturday. High pressure
will build in Sunday, probably followed by an approaching warm
front from the southwest next Monday.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
A cold front is dropping down across New York state and the
northeastern U.S. It will slowly track south and east through
tomorrow night, making it no farther south than the northern
portions of our cwa.
Temperatures tonight will be warmer than last night and closer to
normal. Temperatures will bottom out mainly in the 60s except
around 70 in Philly. The southern Poconos, northwest New Jersey
along with the eastern shore of Maryland have seen a quick drop
off in temperatures this evening. Lows for the overnight were
lowered a couple of degrees in those locations.
Some light patchy ground fog can not be ruled out but the
coverage at this time looks limited and not in the forecast
attm. Only the HRRR has soundings which would indicate a fog
potential in a couple of spots with the highest chances in
southern New Jersey.
Winds will be light and variable through the overnight.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/...
In general, high temps tomorrow are forecast to be several degrees
above today`s highs. Most will still see the 80s, but some lower 90s
across the urban I95 corridor can also be expected.
With a bit more moisture and instability tomorrow, a small chance of
showers and thunderstorms exist across the northern and western
zones. SPC has us in general thunderstorms.
Winds will be on the lighter tomorrow as well, but range from the
south to southwest.
Impacts...outside of some limiting visibilities around daybreak in
some fog, we are not expecting additional impacts.
&&
.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
500MB: Weak west southwest flow will prevail this week, then a -2SD
trough will develop in the Great Lakes region Friday, lifting north
into Canada this weekend, leaving a ridge of southwest flow
aloft, off the east coast into early next week.
Temperatures: Calendar day averages Wednesday-Saturday should range
between 3 and 7 degrees above normal on a daily basis cooling a bit
below normal on Sunday and possibly Monday.
Forecast basis: a 50 50 blend of the 12z/31 GFS/NAM MAVMET MOS was
applied Tuesday night-Wednesday night, then the 12z/31 GFS MEX MOS
for Thursday, and finally the 15z/31 WPC gridded elements of 12
hr max/min T, 12 hr POPS, 6 hrly td, sky, wind were all applied
almost as presented.
The dailies...
Tuesday night...a weak trough-cool front probably slips southward
to near I-80 during the late evening and may serve as a focus for
scattered convection which dies during the night. Patchy fog
possible late, if and where it may have rained. PWAT 1.25".
600J MLC avbl.
Wednesday...That trough still seems to sit near I-80 and again
serves as a focus for scattered heavy afternoon convection north of
I-78...and especially I-80 north with hailers and heavy rainers
possible (both GFS/NAM have fairly robust TT). Modest HOT PHL
~90/65. PWAT 1.5" 1600J MLC avbl esp se PA. GFS has a better chc
than on Tuesday but further se near I-95. Am favoring the NAM
soln.
Wednesday night...the trough may slip south at night along with its
dying convection. Higher BL RH and so patchy fog more likely
late at night near and north of I-78.
Thursday...the trough has eventually dissipated and light flow
from the south resumes everywhere by the end of the day. Almost
as HOT PHL ~90/67. Some of the model guidance is quite robust
for convection Thursday. 1600J MLC. Confidence on the probability
of rain forecast for Thursday is below average.
Friday...hints of drying out and so the convection chance
generally seem to diminish. Still very warm and humid and still
about 1400J MLC. Southerly flow.
Saturday...CFP, possibly early in the day, so smaller chances
of rain and much less chance of thunder. Confidence on rain
occurrence and any thunder after 12z is below avg.
Sunday...Should be a nice day...cooler and less humid. The front
could stall just to our south but for now we save the frontal
rains for Monday.
Monday...Warm air advection and lots of uncertainty regarding
when the next warm front approaches. Could be a pretty wet warm
front but timing uncertainty prevails at this early stage of
the forecast. For now...a conservative forecast.
&&
.AVIATION /02Z TUESDAY THROUGH SATURDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY and surrounding areas.
Tonight...Mainly VFR. Winds will be light, less than 10 kts. They`ll
start off from the southwest and become more west toward dawn. The
afternoon cumulus will dissipate. Some patchy fog is possible
around sunrise with the highest chance at KMIV. However, not in
TAFS attm because of limited coverage.
Tuesday...Mainly VFR. Winds will remain light, less than 10 kts.
They`ll remain from the southwest. The seabreeze should work west of
KACY. There should be more cumulus around tomorrow afternoon and
some showers north and west of the I95 airports. Best chances, which
are small, would be for KABE and KRDG. Can`t rule out thunder.
OUTLOOK...
Tuesday night...VFR conditions expected except small chance of a
shower vcnty KRDG and KABE as well as possible patchy FOG and
asstd vsby reduction early Wednesday morning. Light wind.
Wednesday through Friday...Mainly VFR conditions are expected.
South to southwest sustained winds around 10 knots or less, around
10 to 15 knots at KACY on Thursday and Friday. A chance for
afternoon/evening showers or thunderstorms each day with brief sub-
VFR conditions possible, mainly from KPHL and points north and west.
Most favored TAF sites for afternoon or evening thunderstorms
seems to be vcnty KABE/KRDG. Also there may be some early morning
IFR fog restrictions vcnty KABE and KRDG both Thursday and Friday
mornings.
Saturday...VFR with possible sub VFR conditions in showers...especially
the morning. Gusty westerly winds to 20 kt during the afternoon.
&&
.MARINE...
Winds and seas will stay below SCA conditions tonight and Tuesday. A
few gusts around 15 kt are possible tomorrow afternoon across the
northern NJ Atlantic coastal waters.
OUTLOOK...
Tuesday night through Friday morning...Sub-small craft advisory
conditions are expected to continue through this period
Friday afternoon...SCA winds are possible NNJ waters later in
the day.
Saturday...Small craft advisory westerly wind gusts may develop
during the afternoon.
Rip Currents...
The dominate ocean period could relax a bit tomorrow and
potentially yield a low risk. If this doesn`t come to fruition,
another day of moderate risk can be anticipated on Tuesday.
&&
.CLIMATE...
July average temps:
PHL will average 79.3 (normal 78.1) or 1.2 degrees above normal
ABE will average 75.6 (normal 73.4) or 2.2 degrees above normal.
The rest of the area will have averaged generally 1 to 2 degrees
above normal except GED about 3 above, and slightly below
normal at Mt Pocono, slightly above normal at ACY Marina,
July rainfall:
ACY rainfall 10.02 6th wettest on record (Pomona).
55N rainfall 6.42 14th wettest on record (Marina)
ABE rainfall 8.21 8th wettest on record
RDG rainfall 8.45 5th wettest on record but missing years in the
database for a less certain ranking withing the period of
record.
ILG rainfall 6.75 19th wettest on record
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...None.
NJ...None.
DE...None.
MD...None.
MARINE...None.
&&
$$
Synopsis...Drag
Near Term...Gaines/Kruzdlo
Short Term...Kruzdlo
Long Term...Drag
Aviation...Drag/Gaines/Kruzdlo
Marine...Drag/Kruzdlo
Climate...
Area Forecast Discussion
National Weather Service Reno NV
258 PM PDT Mon Jul 31 2017
.SYNOPSIS...
Intensifying high pressure will bring hot to record-breaking
temperatures to northeast California and western Nevada this
week. Isolated thunderstorms are possible each afternoon through
Wednesday, mainly south of Highway 50. As high pressure shifts
east late this week, more moisture is forecast to surge northward
with increasing thunderstorm coverage.
&&
.SHORT TERM...
Other than to narrow down thunderstorm timing through Wednesday
and add smoke and haze to some areas through Tuesday afternoon,
few changes were made to the short term forecast. The forecast
areas for smoke and haze is a rough estimate and depends much on
the intensity of northeast California fires and whether a light
northwest flow develops in the evening out into western Nevada.
Cumulus development this afternoon has been mostly shallow so far.
The 12Z/18Z NAM simulations show evening convection remaining
mostly west of the Sierra crest with easterly flow aloft; however,
the HRRR supports the possibility for a few cells near and west
of Highway 395 in Mono County. With these discrepancies in mind,
the forecast for isolated cells in Mono County, and perhaps north
of Portola in northeast California, remains intact.
Over the next couple days, the heat really builds as a ridge of
high pressure centers itself over the northern portions of
California and Nevada. This will send high temperatures into the
upper 90s to mid 100s for valleys below 5500 feet, with mid 80s to
mid 90s in the Sierra below about 7500 feet. As far as lows, they
will remain mostly in the 60s for lower valleys; however, for the
urbanized (without much vegetation) areas of Reno-Sparks lows may
not dip below 70 degrees after tonight. Temperatures will eventually
be moderated by increasing cloud cover later in the week. At this
time, temperature moderation from clouds is not expected until
Thursday when moisture begins to increase in earnest from the south.
-Snyder
.LONG TERM...Friday through Monday...
A broad and weak upper low will be lifting north across the
eastern Pacific Fri-Sat which will allow for increasing southeast
flow and moisture into the Sierra and western NV. GFS simulations
show PWATs reaching up to around an inch (at the higher end of
climatology for early August) over the weekend. Thunderstorms
with heavy rainfall and a potential for localized flash flooding
will develop with modest flow aloft and the higher end PWATs.
Temperatures will be a bit more seasonal in this pattern with low-
mid 80s for Sierra valleys and 90s for lower elevation valleys.
Early next week, the coverage of showers and thunderstorms could
decrease some as the upper low moves away and ridging rebuilds.
However, signs are pointing to at least some convective possibility
continuing as moisture/instability fails to scour out completely.
Snyder/Hohmann
&&
.AVIATION...
Any afternoon and evening thunderstorms through Tuesday will
remain isolated with the best chance along the eastern Sierra
south of Markleeville/KMAR. Wind gusts 30-40 kts will be the main
impact. Otherwise, hot afternoon temperatures through Wednesday
will result in high density altitudes which may affect some
airport operations. Snyder/Hohmann
&&
.FIRE WEATHER...
Very hot and dry this week as a strong ridge of high pressure brings
the hottest week of the year to the region. We could see as many as
4 days of 100+ degree heat with dry conditions keeping recoveries in
the poor to moderate range on the mid-slopes and ridges the next few
nights.
Exceptional heat and surge of moisture will bring a substantial
increase in thunderstorm activity for the second half of the week.
Weak isolated storms today are expected mainly in the
Mono/Mineral/S. Lyon county area with a few storms possible in
Lassen and Washoe. Small cells are expected with these storms so
lightning strikes outside of storm cores will be a definite
possibility. Tuesday and Wednesday should see a bit of a lull in the
storm coverage with storms most likely right along the highest
terrain of the Sierra crest in Mono and Alpine counties.
Thursday into Friday a surge of moisture from the south will bring
an increase in thunderstorm coverage. These are going to be the days
to watch for the potential of drier storms along the edge of the
incoming moisture surge, mostly for areas north of I-80. For
Thursday, there isn`t much storm motion, but by Friday southwest
flow aloft will keep storms moving, increasing the threat for
lightning strikes outside of storm cores. At this time there is
not enough coverage, and forecast confidence that storms will be
sufficiently `dry`, to issue fire weather products, however, this
will be an area that could be considered an elevated threat for
new fires.
Temperatures will moderate (closer to normal) for the end of the
week, but thunderstorm activity may continue through the weekend and
into next week. -Zach
&&
.REV Watches/Warnings/Advisories...
NV...Heat Advisory from 11 AM Tuesday to 11 PM PDT Thursday
NVZ001-003>005.
CA...Heat Advisory from 11 AM Tuesday to 11 PM PDT Thursday
CAZ070-071.
&&
$$
For more information from the National Weather Service visit...
http://weather.gov/reno
Area Forecast Discussion
National Weather Service Blacksburg VA
821 PM EDT Mon Jul 31 2017
.SYNOPSIS...
High pressure covered from the Upper Mississippi Valley to Virginia
this afternoon. This high will cover much of the eastern United
States through Wednesday. Thursday through Saturday low pressure
will track from the Upper Mississippi Valley across southeast
Canada, which will push a cold front through the Mid Atlantic region
Saturday.
&&
.NEAR TERM /THROUGH TUESDAY/...
As of 820 PM EDT Monday...
Due to persistence of showers across the Greenbrier and New
River Valley areas, have increased pops for the next couple of
hours, then taper to below 15% around 03Z, then to 0% by 12Z.
Would expect similar situation tomorrow, except a little further
southeast, say from Rockbridge County to Roanoke County to
Watauga County. Have increased pops a tad for Tuesday afternoon
in these areas to reflect this thinking.
Also, adjusted T/Td readings, mainly T readings, in accordance
with current temperatures and trends of cooler nights the past
couple of days. On average tonight should be about 3 degrees
warmer than last night.
As of 305 PM EDT Monday...
A weak mid level disturbance coming across the Ohio Valley this
afternoon is provided additional lift in a low level
convergence zone to generate a few showers across SE West
Virginia this afternoon. Along with modest CAPE values and
steepening lapse rates, storm are growing to a height around
25.0 kft. Not expecting storms to go severe with the -20C level
around 22.0 kft.
Impulse drops to the southeast overnight as the flow aloft
flattens under high pressure overhead. Soundings suggest some
residual mid deck around especially west early on where could
still have a shower or two around during the evening. Appears a
little more subsidence to return behind the passing wave late
when should return to mainly clear skies with some fog in
mountain river valleys. However lows likely to be a bit milder
with dewpoints creeping up, which should promote more in the way
of 60s, except for 50s in the valleys and outlying areas.
Moistening of the atmosphere will continue Tuesday as a broad
upper level trough drifts east of the Mississippi Valley through
the day. More cumulus clouds expected across the mountains
during the afternoon as compared to this afternoon. Adding in
diurnal heating in a weak capped environment, isolated mountain
showers are possible south of hwy 460 with slightly more
coverage of scattered showers north. Weak steering flow will
have these showers tracking northeastward and should not advance
east of the Blue Ridge. Temperatures Tuesday afternoon will
moderate back to seasonal levels with lower 80s west of the Blue
Ridge to upper 80s east.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
As of 215 PM EDT Monday...
Jet streak crossing through the Tennessee Valley along with
upper diffluence may prolong isolated to scattered showers and
thunderstorms into Tuesday evening.
Will be a few degrees warmer each day for high temperatures.
Even more of a rise in surface dew points, especially on
Wednesday with the surface and low level winds coming around to
the southwest.
Models not in great agreement on the location of where the
highest probability of precipitation is on Wednesday or
Thursday, but southwest winds favor along the southern
Appalachians. Will have the highest probability of precipitation
along the Blue Ridge south of Roanoke.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
As of 125 PM EDT Monday...
Models continued to forecast an amplifying upper trof over the
eastern half of the country. Thursday night a short wave will be
tracking through the base of the trough, then a stronger short
wave deepens the trof over the Great Lakes on Friday and
Saturday. On Monday there will still be troughing in the east
but the upper flow over the Mid Atlantic region flattens.
Not much change in the timing of the surface cold front on the
long range guidance. Expecting that boundary to cross the Mid
Atlantic States on Saturday. Most of the precipitation ahead of
the front on Friday will be from daytime heating. Low level
convergence and upper support on Saturday should result in more
areal coverage of precipitation throughout the day. A wave of
surface low pressure along the front on Sunday will hold deeper
moisture and the probability of precipitation over North
Carolina and southern Virginia on Sunday. Temperatures ahead of
the front will be slightly above normal and behind the front
slightly below normal.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
As of 750 PM EDT Monday...
A weak mid-level disturbance tracking southeast from a broader
upper trough to our northwest combined with weak surface
wind/moisture convergence across the Alleghanys has resulted in
isolated to scattered showers developing across the Alleghanys
this afternoon/evening, then pushing southward with the north-
northwest upper flow. The activity is low topped, so no
lightning has been observed. Showers thriving on differential
heating and diurnal heating and area already showing signs of
dissipating. HRRR agrees that most if not all of this activity
will be gone by 03Z. Attendant ceilings and visibilities are
still mainly VFR. This disturbance will weaken and continue to
move southeast into Tuesday. However, an area of weak
surface/moisture convergence will continue to also drift
southeast. Would once again expect isolated to scattered showers
Tue afternoon, but perhaps a little further south and east than
what was observed today. Some models suggest that activity
Tue could be a tad more widespread and of greater intensity, but
still looking at mostly showers, not thunderstorms, with minimal
instability indicated yet Tuesday as well as no deep moisture
present.
So, ceilings will be primarily VFR at the TAF sites through the
valid period. Non-vfr ceilings will be limited to late
night/early morning fog at KLWB and possibly also at KBCB. The
late day rain at both sites suggest greater potential for fog
development. A period of IFR-LIFR is possible at both sites in
the 09Z-13Z time frame. For other locations, fog is generally
not expected.
With weak high pressure remaining to our northwest, a
preponderance of easterly flow can be expected during the day
time at speeds of 4-6kts. Otherwise, winds will be light and
variable with many locations calm at night.
Medium to high confidence in ceilings through the TAF valid
period.
Medium to high confidence in visibilities through the TAF valid
period.
Medium to high confidence in wind direction and speed through
the TAF valid period.
Extended Aviation Discussion...
Mostly VFR conditions are expected to continue Wednesday as a
large area of high pressure lingers across the eastern OH Valley
through the period, gradually weakening. Some late night/early
morning fog will be possible in the mountain and river valleys.
Next chance of reduced visibilities in isolated convection may
occur by Thursday afternoon over the mountains. A cold front
will move into the area late Friday into Saturday with a more
extended period of associated sub-VFR ceilings and visibilities
in showers and thunderstorms.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...None.
NC...None.
WV...None.
&&
$$
SYNOPSIS...RCS
NEAR TERM...RAB/RCS
SHORT TERM...AMS
LONG TERM...AMS
AVIATION...RAB/RCS
Area Forecast Discussion
National Weather Service Shreveport LA
1007 PM CDT Mon Jul 31 2017
.DISCUSSION...
A quiet night areawide expected with many sites already calm.
Skies are variable and while some changes to sky grids were made,
the overall formatting for the 12 hour period is generally the
same as our previous zone issuance and as such no update is
needed here, but we have updated our two matrices products. The
HRRR keeps QPF at bay to our West for the greater part of the
night. Showers will be near by at daybreak with the coming NW flow
energy over the top of the ridge and around the trough entering
the Midwest U.S. /24/
&&
.PREV DISCUSSION... /issued 659 PM CDT Mon Jul 31 2017/
AVIATION...
VFR conditions will continue through the 01/00Z TAF period. The cu
field in place over the region late this afternoon should
eventually diminish by 02-03Z, although additional sct cu
redevelopment is possible after 06Z over N LA/extreme Ern TX and
spreading N into Srn AR by/after 12Z. Cu cigs should again develop
by 16-17Z over much of the region, with additional elevated
convective debris spreading SE into the region by late
morning/through the afternoon from areas of -SHRA that develop
over Cntrl and Ern OK. Sct -SHRA may develop/affect portions of NE
TX and SW AR along/N of I-30 after 15Z, but confidence is too low
to mention in the TYR/GGG/TXK terminals attm. Additional isolated
convection may also develop after 18Z over portions of N LA,
mainly S of the I-20 corridor (including SHV and MLU). Will re-
evaluate the potential for convection Tuesday afternoon/evening
for the 06Z TAF package as sct convection looks to develop and spread
SE across NE TX/SW AR by the end of the TAF period. Light ENE
winds tonight will remain either Lt/Vrb or light ESE after 15Z
Tuesday. /15/
PREV DISCUSSION... /issued 403 PM CDT Mon Jul 31 2017/
DISCUSSION...
Quiet and dry weather will persist through tonight and for much of
Tuesday for most of the area before a prolonged period of
unsettled weather takes hold.
A shortwave trough moving over the Midwest has provided enough
vertical ascent for the development of scattered showers over much
of Eastern Kansas and into portions of Oklahoma. In the Texas
Panhandle, a mesoscale convective vortex has helped scattered
convection persist throughout the day. Northwesterly flow aloft
will help to steer some this activity towards the area, mainly
locations along and north of Interstate 30. Most of this
convection is expected to weaken with eastward extent as it
encounters more stable air. However, a few isolated showers may
linger or redevelop during peak heating Tuesday afternoon, so will
maintain slight chance to chance PoPs. The weak upper trough will
drift southward during the day Tuesday into Southern Arkansas
before turning east towards the Southeast CONUS. This trough
should provide enough support for scattered convection across much
of the area Wednesday and Thursday. The highest rain chances will
be across portions of East Texas on Wednesday but will shift east
along with the trough into Southern Arkansas and Northern
Louisiana on Thursday.
A retrograding upper ridge over the Four Corners Region and a
longwave trough over the eastern half of North America will
strengthen the northwest flow aloft over the region. Another, but
stronger, shortwave trough will develop across the Upper
Mississippi River Valley on Thursday and will help to push a cold
front into the area. This front should provide a better focus for
convective development as the it moves through on Friday. Severe
weather potential appears low at this time as instability will be
rather meager.
The flow aloft will become slightly more zonal during the weekend,
but the parade of shortwave troughs across the region will
persist. Medium range models suggest the Friday cold front will
become quasi-stationary between Interstates 10 and 20 before
moving back north as a warm front late in the weekend and into
early next week. Combined with the continued series of shortwave
troughs, this will keep a decent chance for scattered showers and
thunderstorms across portions of the area nearly every day from
Saturday through next Tuesday.
This is certainly a much wetter and more unsettled pattern than is
typical for this time of year for our region. The added benefit to
the increased rain chances and associated cloud cover will be that
daytime temperatures will generally hold steady near or slightly
below normal. Depending on how much rain falls, some increased
humidity is likely, but the cooler temperatures should keep heat
index values below 100 degrees F for at least the next seven days.
CN
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 75 91 73 85 / 0 10 20 40
MLU 71 91 72 86 / 0 10 10 30
DEQ 70 85 68 86 / 10 20 20 30
TXK 71 87 70 84 / 0 20 20 40
ELD 71 89 70 85 / 0 10 20 30
TYR 73 90 71 84 / 0 20 30 60
GGG 73 91 71 84 / 0 20 20 60
LFK 72 92 74 87 / 0 10 20 40
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...None.
LA...None.
OK...None.
TX...None.
&&
$$
24/15/09
Area Forecast Discussion
National Weather Service Topeka KS
1051 PM CDT Mon Jul 31 2017
.UPDATE...
Issued at 1034 PM CDT Mon Jul 31 2017
Skies have been clearing out faster than progged and have adjusted
sky grids and added the potential for patchy to areas of fog in
locations that received rainfall earlier today.
&&
.SHORT TERM...(This evening through Tuesday)
Issued at 313 PM CDT Mon Jul 31 2017
19Z water vapor imagery shows an upper shortwave moving south along
the mid MO river valley while a broad area of high pressure remained
centered over the TX big bend region. At the surface, an expansive
high pressure system was centered over the upper Midwest with a
ridge axis stretching back west through northeast KS.
For tonight, the models have been struggling to show the light rain
very well even though they show some weak vorticity advection from
western KS. Eventually the shortwave to the north of the area should
propagate across the forecast area overnight. So with some signal
for forcing through the evening and since the HRRR has been the only
solution with a reasonable handle on the precip, think continued
light rain across east central KS through the evening as depicted by
the HRRR makes some sense. There does not appear to be much in the
way of instability within this airmass so the expectation is for the
rain to remain light with only a couple hundredths of an inch in
accumulation. With the precip, skies are expected to remain mostly
cloudy though a good portion of the night. Think this may help keep
temps a degree or two warmer and have lows forecast to be in the
lower and middle 60s.
The upper shortwave is progged to be exiting the area by Tuesday
morning. As a result, models think there should be general
subsidence across the area through the day. Because of this have a
dry forecast going for the daytime hours. Although a little better
surface based instability is expected to develop. So it may not be
out of the question for a shower to pop up. A lack of surface
feature to focus low level convergence makes the predictability
pretty low. The surface ridge axis is forecast to continue to
influence the region keeping winds light with no real temp advection
to speak of. So think highs will be driven mainly by insolation.
Think that there may be partly sunny skies through the day with
models keeping some mid level saturation over the region. So have
not gone quite as warm as the guidance and have highs forecast to be
in the middle 80s.
.LONG TERM...(Tuesday night through Monday)
Issued at 313 PM CDT Mon Jul 31 2017
Mid week through the weekend, the upper pattern will exhibit the
general western ridge and eastern trough pattern with mainly
northwest flow through the central CONUS. This will provide a few
opportunities for some needed rainfall over northeastern KS.
However, speed of the systems and overall moisture quality probably
won`t allow for much in the way of significant amounts of measurable
precip.
There isn`t a significant chance of rain or storms making their way
into the area on Tuesday night, but if an overnight complex from the
high plains can maintain itself there could be some showers make
their way into western and northern counties around the KS/NE border
area. The better chance comes into the Wednesday night and Thursday
morning time frame when a stronger H5 trough with associated vort
max works into the Northern Plains and Upper MS Valley region
helping to push a cold front into the area late afternoon into the
overnight period Wednesday. Currently, NAM, GFS and ECMWF are
largely in agreement on timing and strength of the front into the
area. Perhaps the GFS and NAM are just a touch faster moving the
boundary through than the EC. Overall, storms develop some type of
mixed mode in central Nebraska where instability and shear set up is
better along the front. By the time storms make a run into
northeastern Kansas, there may be some wind threat that could be
maintained due to steep low level lapse rates with higher
dewpoint depressions in place. But, a prolonged threat of
hazardous winds doesn`t seem to last too long as storms will
likely move into a much less favorable environment with little
instability, weak shear and overall poor mid level lapse rates for
any nocturnal storms to be sustained very long. Post frontal
showers could linger until the upper trough passes into the day on
Thursday.
Latter part of the weekend could see another shot as some showers
and storms as a stronger upper shortwave digs into the area helping
storms developing over the high plains of Northern into the Central
Rockies maintain support as they propagate into the Central Plains.
Temps overall during the period remain cooler in the low 80s due to
northwest flow in place with lower dewpoints also as return flow
doesn`t have as much opportunity to develop.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 626 PM CDT Mon Jul 31 2017
Light showers will push out of central and east central Kansas
this evening with otherwise VFR conditions and light winds
tonight into tomorrow. There may be some isolated showers and
storms tomorrow afternoon, but confidence was not high enough to
mention in any specific TAF.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Skow
SHORT TERM...Wolters
LONG TERM...Drake
AVIATION...Skow