Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 06/25/18
Area Forecast Discussion...UPDATED
National Weather Service Albuquerque NM
548 PM MDT Sun Jun 24 2018
.AVIATION...
00Z TAF CYCLE
A challenging forecast across the east where outflow boundaries from
active convection along the NM/CO border will help kick down a
backdoor front tonight. Arrival of the front will first reach to KTCC
by 03Z-04Z, KLVS by 05Z, KROW by 07Z, and wrapping around the Sangre
de Cristo`s into KSAF by 09Z. The front will squirt through the
central mtn chain bringing gap wind gusts above 20kts to KABQ after
09Z to around sunrise. Low clouds are once again a likelihood at
eastern TAF sites, including KTCC, KCVN, KCVS, and KCAO. Confidence
is not very high at this time to include any MVFR cigs. Winds shift
out of the south across the east tomorrow, with westerly winds mixing
down across western and central NM.
24
&&
.PREV DISCUSSION...320 PM MDT Sun Jun 24 2018...
.SYNOPSIS...
An upper level low pressure system is slowly moving off of the
central Rockies and into the central plains of the nation. This
feature is bringing some breezy to windy conditions to portions of
New Mexico today. Dry conditions and hot temperatures are in place
over most of the state, but a surface boundary from decaying
thunderstorms did move into northeastern and east central New Mexico,
keeping temperatures cooler along with higher humidity. In addition
a cold front is expected to drop out of Colorado and into eastern New
Mexico later this evening and tonight. This will produce showers and
thunderstorms, mostly over the northeastern corner of New Mexico
with a few strong to severe storms possible. Gusty winds will
accompany the previously mentioned cold front as it slides down the
plains and then advances west into the Rio Grande valley tonight.
Temperatures will run a few to several degrees cooler in central to
eastern New Mexico Monday, before warming up through the middle of
the week. Low precipitation chances are expected through mid week
with high terrain areas in southern New Mexico being most likely to
observe an isolated storm.
&&
.DISCUSSION...
Early morning synoptic models were struggling with forecast details
over northeastern NM as the outflow boundary from the decaying MCS
over OK moved into our area earlier. This has kept some low clouds
in place over northeast NM with a more moist easterly flow also
expanding over northeast and even east central parts of our forecast
area. This outflow boundary stunted destabilization, but current
LAPS analysis shows increasing instability, and satellite trends
reveal the cumulus field along and just east of the Sangres is
gaining more vertical development. Latest 19Z HRRR shows the real
action arriving with the back door cold front this evening, likely
favoring Union county. This seems plausible, but would also not be
surprised if a stray storm or two roll off of the Sangres prior to
the front`s arrival. Healthy deep layer shear, high 0-3 km helicity
will be in place over northeast NM, keeping an elevated risk for
strong to severe storms, and SPC has expanded the enhanced risk into
our far northeastern zones. The front, likely aided by convective
outflow, will spill westward into the Rio Grande valley tonight with
gusty canyon winds ensuing near Albuquerque and Santa Fe.
The front will bring a brief uptick in dewpoints/relative humidity to
central zones, but veering surface winds by Monday afternoon should
mix the moisture back just east of the central mountain chain. Any
prospects for storms would be low and confined to the south central
mountains and points east. Temperatures would be notably cooler in
the eastern half of the state, and no need for heat advisories is
expected, at least for Monday.
High pressure aloft would be drawn closer to NM on Tuesday. Surface
winds would struggle to retain the south southeasterly direction in
the plains, and consequently the low level moisture will struggle to
hold on through the afternoon. Again, the best prospects would be
over the higher terrain of Lincoln county with chances quickly
falling off farther west, north and east of there. Temperatures would
start to climb back up, surpassing late June averages by 5 to 10
degrees.
By Wednesday, the dome of high pressure aloft will establish itself
more directly over NM, allowing subsidence to increase with rising
pressure heights and temperatures. Triple digit readings will be
more common in the valleys and eastern plains Wednesday. The GFS
indicates some faint mid level moisture will make it to the
southwestern and south central mountains, but suspect this would be
more of the virga or dry thunderstorm variety, as surface dewpoints
would not support any true wetting precipitation.
The GFS continues this trend of expanding meager mid level subtropical
moisture northward into more of NM through week`s end. There is
skepticism that any meaningful increase in the probabilities of
precipitation is warranted, as again the boundary layer moisture will
be lacking. The GFS is also more amplified with a western U.S. trough
that would aid the "squeeze" of mid level moisture northward into
NM, whereas the European carries a dampened trough into the northern
Rockies toward the weekend. For now, mostly slight chance POPs have
been built into the extended forecast, generally favoring high
terrain areas south of I-40.
52
&&
.FIRE WEATHER...
...CRITICAL FIRE WEATHER CONDITIONS THIS AFTERNOON AND EARLY EVENING
ACROSS NORTH CENTRAL AND NORTHWEST NEW MEXICO...
The base of the trough moving through southern CO this afternoon has
produced a band of stronger winds aloft across northern NM. West
winds 15 to 20 mph across northwest and north central NM this
afternoon and early evening will combine with low relative humidity
and an unstable atmosphere to produce critical fire weather
conditions in FWZ101 and FWZ102. A back door cold front will move
quickly across the eastern plains tonight and reach the central
mountains by around dawn. Increasing moisture behind the back door
cold front will result in good to excellent relative humidity
recovery east of the central mountains tonight.
Northwest flow aloft will bring drier air across northern and
central NM Monday. Relative humidity Monday afternoon will fall into
the single digits across western NM, but relative humidity across
the eastern plains will be in the upper teens and 20`s. High
pressure aloft will move over western NM Monday afternoon, and winds
will be less than 15 mph, except 15 to 20 mph across the northeast
highlands. Haines values will be low across the eastern plains and
moderate to high across the rest of the area Monday afternoon.
Strong high pressure aloft will settle over NM Tuesday through
Thursday with light winds, low to very low relative humidity, above
normal daytime temperatures and unstable atmospheric conditions.
Models are not in agreement on the longer term forecast for Friday
through Sunday. The GFS moves the upper level high to the east and
shows an increasing tap of subtropical moisture from northern Mexico
moving northward across NM, while the ECMWF keep a drier west flow
over NM.
28
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
Red Flag Warning until 7 PM MDT this evening for the following
zones... NMZ101-102.
Heat Advisory until 9 PM MDT this evening for the following zones...
NMZ538.
&&
$$
Area Forecast Discussion
National Weather Service Columbia SC
820 PM EDT Sun Jun 24 2018
.SYNOPSIS...
High pressure will extend from the Atlantic westward into the
Gulf of Mexico through Monday. Expect above normal high
temperatures in the mid 90s to around 100 degrees today and
Monday. A cold front will push into the area Monday night and
Tuesday bringing showers and thunderstorms. Tuesday should be
the coolest day in the past week or so due mainly to increased
cloud cover. A more climatological pattern unfolds for the
remainder of the period with increasing moisture and ridging
into the Southeast. This pattern supports scattered diurnal
thunderstorms and above normal temperatures.
&&
.NEAR TERM /UNTIL 8 AM MONDAY MORNING/...
Thunderstorms will continue crossing the forecast area through
06Z. Damaging wind will be possible with the thunderstorms this
evening.
The airmass remains moderately unstable with lifted indices
from minus 4 north to minus 8 south and CAPE values 2000 J/kg
north to 4500 J/kg. Latest HRRR and RAP still indicate scattered
thunderstorms mainly this evening across the north Midlands and
Pee Dee aided by mid level short wave trough rotating over an
upper ridge to our south. Less convective coverage across the
southern part of the forecast area. The storms should diminish
around 06Z. Overnight low will remain consistent...in the low
to mid 70s.
&&
.SHORT TERM /8 AM MONDAY MORNING THROUGH TUESDAY NIGHT/...
Mid-level ridging will be over the Southeast on Monday, with NW
downslope flow bringing hot and dry conditions into the
Midlands and CSRA. Subsidence over the area will result in a
capping inversion through much of the day. Without a surface
trigger, expect any showers and thunderstorms that develop
during the afternoon to be isolated to widely scattered. Despite
the limited coverage, warm, moist low-levels, and moderate mid-
level lapse rates will create moderate to strong potential
instability and a deep inverted V sounding. If stronger
convection develops, then damaging downburst winds will be a
threat, and the SPC has the region under a marginal risk for
severe storms. High temperatures will be in the mid to upper
90s, but dewpoints will be a few degrees cooler than Sunday,
keeping heat index values around 105 degrees, below advisory
criteria.
A cold front will sag southward into the forecast area Monday
night, accompanied by a digging upper level shortwave. Showers
and thunderstorms will be likely, especially over the northern
and eastern Midlands. Heavy rain is also indicated, with
precipitable water above 2 inches, and both the 12Z NAM and GFS
showing an MCV moving from the Ohio Valley into North Carlina
and then northern South Carolina. Elevated instability will
also remain over the forecast area through the night with
forecast soundings showing a deep elevated mixed layer. This
pattern typically supports thunderstorms and a threat of severe
weather. Cloudiness and increased mixing along the front will
keep low temperatures warmer than normal, in the low to mid 70s.
Some convection will likely persist through Tuesday morning, and
with the front stalled just south of the area, scattered showers
and thunderstorms will remain possible through the day. The increased
cloud cover and slightly cooler air behind the front should make
Tuesday one of the coolest days in the past week or so, with highs
only in the upper 80s to lower 90s.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
Transitional high pressure will build into the area on Wednesday.
While diurnal convection is still possible, much drier
conditions are expected. Both the GFS and ECMWF then show
another shortwave moving through the region on Thursday, and
scattered thunderstorms will be possible. A low will develop off
the coast on Friday, as high pressure amplifies over the
eastern US. Have kept chance PoPs across the area, but the
better chance for convection will probably be across the eastern
Midlands where there will be more moisture associated with the
low. Onshore flow increases Saturday and Sunday with high
pressure centered to the north, with supports warming
temperatures and a climatological pattern of scattered afternoon
convection. Expect highs in the mid to upper 90s and lows in
the 70s.
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
Scattered thunderstorms crossing the TAF sites this evening.
Strong gusty winds with storms. Expect mainly VFR conditions
after 06Z.
A cold front will approach the TAF sites from the north toward
the end of the TAF period bringing a chance of thunderstorms.
EXTENDED AVIATION OUTLOOK...Restrictions possible each day in
early morning fog and afternoon and evening thunderstorms.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
GA...None.
SC...None.
&&
$$
Area Forecast Discussion
National Weather Service Charleston SC
1132 PM EDT Sun Jun 24 2018
.SYNOPSIS...
High pressure will extend across the region through Monday. A
cold front will drop south into the area Monday and linger near
or just south of the area through mid-week. Low pressure could
develop off the Southeast U.S. next weekend.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
Late this evening: Well, it turns out the HRRR did a really good
job depicting the intensification of convection with the
convergence of outflow and the sea breeze. A strong line of
storms with plenty of momentum pushed into Berkeley County and
produced several downed trees around Lake Moultrie. Now the
upstream convection is undergoing further enhancement across
Orangeburg County where outflow from the west is interacting
with the sea breeze and this activity will push further south
into Dorchester and Colleton counties over the next hour or so.
The severe threat remains despite the surface being capped off
around 1,500 feet based on the 00z KCHS RAOB. The severe threat
continues along and ahead of this line, almost solely for
damaging winds. Adjusted rain chances to reflect current radar
trends and the follow the HRRR over the next several hours.
Early this evening: All is quiet right now with the sea breeze
progressing inland and just a few vertically challenged cumulus
across the forecast area. However, a glance at regional radar
imagery indicates convection is developing upstream and is on
track to approach the forecast area later tonight. This upstream
convection appears to be initiated and driven by some sort of
MCV and the prevailing deep layer flow puts it on track to head
toward at least the southeast South Carolina portion of the
forecast area. The environment ahead of this developing
convection is certainly unstable with MLCAPE on the order of
2,000-3,000 J/kg, which would seem to support further downstream
development. However, we are losing insolation after sunset but
the atmosphere is relatively untapped based on minimal
convection the past several days. Dry air in the mid and upper
levels results in DCAPE values around 1,000 J/kg which would
support at least some degree of a damaging wind threat. Hi-res
models such as the HRRR the the approaching convection
intensifying as it interacts with the sea breeze across the
Midlands. The idea is then that the convection progresses
further to the southeast and impacts mainly the Charleston Tri-
County region and Colleton County. Adjusted all forecast
parameters to favor such a solution. Current timing would bring
thunderstorms into the area around 9-10pm, then to the
Charleston County coast around midnight. The overall severe
threat is hard to judge given that thunderstorms will be coming
through in the late evening. But, since the atmosphere is
relatively untapped and DCAPE values are high, there is a
potential for damaging winds, especially if convection can get
organized along a line and become cold pool driven.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY/...
Few changes were made to ensure consistency with overnight
shift.
A cold front will approach from the northwest Monday and then
move south into the area Monday night before stalling nearby
through the rest of the period. This will mean a more unsettled
period with decent rain chances is expected Monday night into at
least Tuesday. Some of the storms could be strong late Monday
afternoon/evening, mainly across SC, given the high DCAPE values
(1000+ J/kg) and steep low to mid-level lapse rates.
Temperatures will remain above normal Monday ahead of the front
with heat indices peaking into the Heat Advisory range 105-108
inland, 108-112 coast.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
Minor changes were made per regional coordination with NHC/WPC
on the potential for low pressure developing off the Southeast
U.S. coast.
The latest medium range model guidance suggests the stalled
cold front will dissipate as an offshore high pressure/inland
trough pattern likely sets up. Low pressure is expected to
develop off the SC/NC coast by late week and drop southwest to
somewhere near or offshore of the GA/FL coast over the weekend
per track coordination with NHC/WPC. Depending on the eventual
development and track of the low, increased rain chances and
breezy conditions could develop.
&&
.AVIATION /03Z MONDAY THROUGH FRIDAY/...
The main concern is the potential for thunderstorms to impact
KCHS this evening. Thunderstorms are developing upstream of the
area and are expected to move through late this evening from the
northwest. Confidence is increasing based on recent hi-res model
runs, and prevailing VCTS has been added starting at 03z. A
TEMPO is then in effect from 03-05z with low end gusty winds and
MVFR visibilities. It does not appear thunderstorms will be a
concern at KSAV. For the rest of the period, VFR conditions are
expected.
Extended Aviation Outlook: Risk for tstm impacts possible
Monday Night into Tuesday and again by late week into the
weekend depending on track of low pressure offshore.
&&
.MARINE...
Tonight: An inland surface trough and high pressure in the
Atlantic will drive the weather pattern. Winds will peak along
the immediate coastline through early this evening. Though,
locally higher gusts are possible along the SC coastline. By
late evening the winds will ease a few kt, then a second surge
in winds is possible further offshore, lasting until almost
daybreak. Additionally, winds closer to the coast should veer
more towards the west around daybreak as the land breeze
develops. Seas will average 2-3 ft, except 3-4 ft across the
Charleston waters during the peak winds. There is a slight
chance strong thunderstorms may develop inland this evening and
move offshore tonight, producing hazardous weather for mariners.
Monday through Friday: Few changes were made through mid-week
to ensure consistency with the overnight shift. Southerly winds
will prevail ahead of a cold front Monday with enhanced sea
breeze influences possible. Front will backdoor into the region
Monday Night into Tuesday. There is potential for low pressure
to develop off the Southeast U.S. coast by late week. Small
Craft Advisory conditions are not expected.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...None.
SC...None.
MARINE...None.
&&
$$
NEAR TERM...BSH
SHORT TERM...ST
LONG TERM...RJB
AVIATION...BSH/ST
MARINE...MS/ST
Area Forecast Discussion
National Weather Service Cheyenne WY
524 PM MDT Sun Jun 24 2018
.SHORT TERM...(This evening through Tuesday night)
Issued at 235 PM MDT Sun Jun 24 2018
Upper low evident on satellite over east-central Wyoming this afternoon
with some bands of showers and storms over mainly the southern parts
of the CWA. little rain has fallen over the north and with only some
showers and maybe a few storms expected into this evening have cancelled
the Flood Watch as the threat for flooding appears to be quite low
now. Otherwise, the upper low will move east slowly overnight with
pcpn coming to and end. HRRR holds on to some pcpn over SE Wy this
evening, so have added in some low pops there.
Monday will see a return to drier and warmer weather with the upper
low continuing to drift east. Not out of the question to see some
showers over the eastern Panhandle in the afternoon with somewhat
cooler mid-level temps. Clear Monday night and Tuesday with a short
upper ridge passing across. Quite warm Tuesday with max temps low
to mid 90s over much of the NE Panhandle as 7H temps warm to over 20C.
.LONG TERM...(Wednesday through Sunday)
Issued at 235 PM MDT Sun Jun 24 2018
Zonal flow aloft Wednesday between upper ridge over the southern
Rockies/high plains and trough north of the US-Canadian border.
The flow aloft backs to southwest Wednesday night/Thursday with
strengthening ridge over central/southern Plains and upper trough
moving into the Pacific coast states. East-west oriented surface
front from central SD into southern MT will drift a bit further
south Thursday, however dry southwest flow aloft will prevail. The
southern extent of convection remains just north of Converse/Niobrara
counties through Friday. Front pushes south into the high plains
late Friday afternoon and evening with scattered convection developing
east of a Lusk WY-Kimball NE line. Front drifts west and stalls along
the Laramie Range Saturday, with scattered convection along and east
of the front into Saturday night. Models hint at a MCS developing
east of the front over the NE Panhandle. After isolated morning
showers or tstorms northeast plains, drier southwest flow will spread
across the CWA Sunday. Well above normal temperatures are forecast
Wednesday and Thursday with 700mb temperatures between 20 and 22
deg Celsius Thursday. High in the 90s will be common east of I-25,
with a few locations in the NE Panhandle equaling or exceeding 100
deg. Temperatures then cool back to near normal this weekend.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 523 PM MDT Sun Jun 24 2018
VFR. Wind gusts to 22 knots through 03Z, then up to 25 knots after
15Z Monday.
&&
.FIRE WEATHER...
Issued at 215 PM MDT Sun Jun 24 2018
An upper low pressure area over eastern Wyoming will move east overnight.
As it does so scattered showers and a few thunderstorms will come to
an end over the districts. The next few days will see a return to warmer
and mainly dry conditions which could increase fire weather concerns
a bit over western areas by mid-week.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...None.
NE...None.
&&
$$
SHORT TERM...RE
LONG TERM...MAJ
AVIATION...RUBIN
FIRE WEATHER...RE
Area Forecast Discussion
National Weather Service Sioux Falls SD
704 PM CDT Sun Jun 24 2018
.SHORT TERM...(This evening through Monday night)
Issued at 444 PM CDT Sun Jun 24 2018
Duo-faceted concern over the next couple of days, namely the
potential for severe storms and heavy rainfall. Deep trough pushing
through the Rockies with leading jet punching toward central
Nebraska, with pressures falling and development of an inverted
trough through central into eastern Nebraska. Another boundary was
located across southwest MN and into IA, reinforced a bit more
across southwest MN from earlier convection across Minnesota.
As we approach the peak of diurnal heating which has produced an
axis of MLCAPE approaching 2000 J/kg, storms have been bubbling up
along the more favored convergence axes, and toward better large
scale forcing pushing into south central SD. Overall, the deep-layer
shear remains fairly weak with the weak flow aloft near exiting mid-
level ridging, but low-level shear is a bit more notable especially
near the boundary. Likely that updrafts going into the evening near
these boundaries will be able to support stretching and potential
funnels/tornadoes along with some marginally large hail. Structures
are much more likely to evolve into a mass of multicell activity
fairly quickly in the period. Other concern is potential for heavy
rainfall, which is supported by higher PWAT values as well as the
relatively slow storm motion. Convection should be more greatly
favored east of I-29 heading through the evening, more scattered to
the west, then a slow decrease until deeper forcing returns later in
the night.
Disturbing developments in just the latest HRRR and 18z NAM which
produce an axis of 3+ inches rainfall from near Sioux Falls
northeast through southwest MN. Will have to keep an open mind as to
potential for some locally heavy rainfall this evening if cells can
align through the evening hours, but would likely become apparent
fairly quickly this evening if this was going to occur. For the most
part, heavy rainfall threats are expected to be more localized
through this later afternoon and evening. Coordinated with
neighboring offices and did not issue any additional flood watches
with a more localized threat for heavy rainfall tonight.
Main forcing with approaching upper wave looks to swing northeast
toward the Missouri River early morning with likely band of
showers/thunder rotating northward through the day and wrapping
gradually back into deformation northwest of upper low toward south
central SD. The later morning through afternoon period would likely
have the most widespread precipitation, but likely organized in
bands rotating northward through the area with lack of a good
thermodynamic boundary to work with. Rainfall could easily total a
half inch to inch and a half during this period.
Again must look more into later afternoon and early evening, behind
the leading surge of precipitation wrapping northward, where a bit
better MLCAPE recovery can occur toward northwest IA and northeast
NE, along with increasing shear as jet punches northward east of the
upper low through northwest IA. Shear increases to 30-40 kts, so
assuming a recovery toward 1-2kJ/kg, will again have to watch for
all modes of severe weather across mainly northeast NE, far
southeast SD and northwest IA, especially southeast of a KSUX-KSPW
line.
Heavier precipitation threat will return leading and closer to the
core of upper low around Monday night mainly toward northwest IA and
southwest MN. Looking quite likely that most areas will see
potential of system total rainfall from 1-3" through Tuesday
morning, which is certain to either return areas to flood along
mainstem rivers and streams, or slow the fall to peaking a second
time for those rivers already in flood. Needless to say, will be a
busy week on the hydrology front.
.LONG TERM...(Monday night through Sunday)
Issued at 444 PM CDT Sun Jun 24 2018
Upper low begins to slip away on Tuesday with residual moisture and
instability likely resulting in a scattering of showers and thunder
through the day, especially southwest MN into the Iowa Great Lakes
area. Temps recovering 4-8 degrees from Monday`s lower to mid 70s.
Beyond Tuesday and the exit of the upper-level low, will be seeing
temperatures warming impressively aloft (as much as +16 to +18C).
Wednesday night will see the push of the stronger EML along with a
little convergence of lower to mid-level flow, so continue to carry
a low chance for elevated convection mainly later in the night.
Otherwise, appears to be fairly low confidence in precipitation with
models diverging in the progression of the main frontal boundary
from Friday through Saturday and collapse of the warmer bubble aloft
as wave knocks down ridge, with more confidence of not having
convection than having convection by later Friday into Friday night.
Prospects would likely improve for convective development heading
toward Saturday night/Sun. All in all, will be a very warm and very
humid close to the week before moderation to temps over the weekend.
Could see a need for heat advisories at some point if dew point
readings are as high or higher than forecast.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 703 PM CDT Sun Jun 24 2018
With ongoing severe weather and flash flooding, limited time for
discussion. Outflow boundary approaching Sioux Falls may cause
brief period of gusts from 130 degrees after 0045 UTC tonight.
Winds will remain southeast for the remainder of the night.
Otherwise, looking for convection develop around Sioux City
between 06Z and 12Z and spreading north to Sioux Falls and Huron
during the morning. In addition to thunderstorms, MVFR ceilings
and visibilities will be possible with brief periods of IFR
conditions in the strongest storms.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...None.
MN...None.
IA...None.
NE...None.
&&
$$
SHORT TERM...Chapman
LONG TERM...Chapman
AVIATION...Schumacher
Area Forecast Discussion...UPDATED
National Weather Service Fort Worth TX
718 PM CDT Sun Jun 24 2018
.AVIATION...
/00Z TAFs/
VFR with gusty south winds. Morning stratus.
The MCS that doused Oklahoma today is clipping Northeast Texas.
The outflow has impacted the row of counties on the Texas side of
the Red River. While the wind shift will remain well north of the
Metroplex TAF sites, some backing of the surface flow will occur
on the south side of the boundary (though this will be largely
indistinguishable from typical evening backing).
Storms have developed along a West Texas dryline again this
afternoon, but the areal coverage is considerably less than the
previous day. This activity will attempt to push east across the
Big Country this evening, but increasing CINH and decreasing mid-
level lapse rates to the east should steadily dissipate the
activity well west of the Metroplex TAF sites.
The activity in southeastern Colorado will make a charge through
Oklahoma tonight. As with its predecessor, the thunderstorms and
associated outflow should remain north of the Metroplex early
Monday morning.
Breezy south winds will continue overnight. Despite a low-level
jet of 40kts, the lack of decoupling will help to shear the
invading stratus, delaying the onset of ceilings. Nonetheless,
MVFR conditions will prevail by daybreak. A similar scattering
trend will occur before midday.
The breezy winds will continue Monday night, and the next stratus
intrusion may need to be introduced into the extended portion of
the DFW TAF with the 06Z package.
25
&&
.SHORT TERM... /Issued 342 PM CDT Sun Jun 24 2018/
Primary concern for tonight`s forecast is the convective activity
currently to our north and the development of another complex in
the High Plains late tonight. The MCS in Oklahoma made a run at
the CWA, but as expected has encountered a drier and more stable
airmass over the region and is being deflected to the left. While
an outflow boundary is expected to move south of the Red River,
the region is likely too capped for this boundary to kick off any
surface based convection. In fact we suspect the MCS is still
elevated above a strong cap and is sustaining itself on unstable
parcels near 800 mb. Still a few elevated showers or storms may
develop over the northern counties over the next several hours on
the southern flank of this complex. The northeast counties may
have the best rain chances as the southern edge of the MCS should
try to move into northeast Texas. We will continue to watch trends
closely for signs of any atmospheric changes, but at this point
we will stay with low PoPs for just the northern zones.
Otherwise moderate southerly winds will prevail overnight and
result in another round of nocturnal stratus cloud cover for most
of the region. The combination of winds and clouds should ensure
another warm night with lows in the mid 70s to near 80.
TR.92
&&
.LONG TERM... /Issued 342 PM CDT Sun Jun 24 2018/
/Monday through Sunday/
An active pattern will remain in place across the central Plains
through Tuesday but most of the precipitation will remain north of
our area. By mid week, stronger ridging will build into the Plains
keeping things mostly hot and dry.
The main concern through the early part of the week will be
convective chances tomorrow morning and again tomorrow night into
Tuesday morning mainly across the north and northwest parts of the
region. Latest high resolution guidance continues to show another
strong MCS moving across Oklahoma tonight with a rather strong
outflow boundary pushing into North Texas Monday morning
accompanied by an increase in showers and perhaps a few
thunderstorms. While this scenario is certainly within the realm
of possibility, the high resolution guidance has done a terrible
job with the current elevated MCS activity across Oklahoma this
afternoon. In the wake of this complex of thunderstorms,
temperatures are still in the 60s across much of central and
northern Oklahoma, so the atmosphere would have to recover rather
quickly. While it is likely that additional thunderstorms will
develop later tonight across the TX Panhandle and northwest
Oklahoma, it appears unlikely that they will be quite as robust as
the last few nights. That being said, the associated outflow
advertised by the HRRR will probably be significantly weaker. For
now, we`ll hang on to some very low PoPs mainly along the
immediate Red River for Monday morning.
Later in the day farther south it looks like a slug of moisture
will spread inland off the western Gulf into southeast Texas. This
will likely allow for a few scattered sea breeze showers and
thunderstorms to spread inland into our southeast counties. We`ll
have some 20% PoPs across our southeast counties to account for
this.
By Monday evening, a strong shortwave trough will swing through
the Central Plains. The best forcing will be well removed from our
area but a weak frontal boundary will be draped across central
Oklahoma into northwest Texas. Scattered thunderstorms are
expected to develop along the boundary and may clip some of our
northwest counties. We`ll keep some 20% PoPs across the far
northwest into the overnight hours. This area will remain quite
unstable so any storms that develop could be strong to severe
although strengthening inhibition should mean a quick death as
they try to move east overnight.
Tuesday through the end of the week looks mainly hot and dry as
the main troughing over the central Plains moves east and stronger
mid level ridging builds in. Outside of some low rain chances in
the southeast associated with the sea breeze, most areas should
remain precipitation free. Highs will continue to top out in the
mid to upper 90s with low 100s well west of I-35.
Dunn
&&
.PRELIMINARY POINT TEMPS/POPS...
Dallas-Ft. Worth 79 96 77 98 79 / 10 5 5 5 0
Waco 78 96 76 98 76 / 5 20 5 5 0
Paris 78 93 74 95 77 / 50 10 10 5 0
Denton 78 97 76 98 79 / 10 5 10 5 0
McKinney 78 93 72 97 78 / 20 5 10 5 0
Dallas 80 96 79 99 79 / 10 10 5 5 0
Terrell 78 98 76 97 77 / 10 10 5 5 0
Corsicana 79 93 76 97 75 / 5 20 5 5 0
Temple 78 94 75 96 74 / 5 20 5 5 0
Mineral Wells 76 98 75 99 77 / 5 5 10 5 0
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
25/24
Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
1035 PM EDT Sun Jun 24 2018
.SYNOPSIS...
Scattered showers and thunderstorms will persist through Monday as
the region remains in a warm and humid airmass. A weak cold front
will drop into the forecast area early next week, bringing more
seasonable temperatures Tuesday. A passing trough will increase
chances for showers and storms Wednesday, with hot weather returning
to end the week.
&&
.NEAR TERM /THROUGH MONDAY/...
As of 1035 PM EDT Sunday: Minor adjustments made to temperatures,
PoPs, and winds to coincide with latest trends as the rest of the
near term forecast remains on track.
With a sfc high over the GOM extending northward through the
Southeast and a nearly stationary front just northwest of the
Carolinas, conditions have quieted down across the FA tonight as
shower and thunderstorm activity continues to progress well
south and east of the area. Expect these quiet conditions to
prevail overnight, though patchy fog is possible late overnight
into early Monday morning, mainly across the mountain valleys.
Overnight low temperatures are expected to drop into the lower
70s along and south of the I-85 corridor, cooling into the lower
60s back towards the NC mountains.
Otherwise, potentially more significant convection will occur on
Monday when SPC has the area in a marginal risk category with some
prospect for an upgrade to slight. NAM and extended HRRR have shown
an MCS with an MCV structure propagating along frontal zone from IL
to TN, reaching the GSP area Monday afternoon. Timing is favorable
for continuing any severe convection with this feature. If this
feature becomes sufficiently organized, more wide spread severe
winds may be possible. Temperatures will remain 5 or so degrees
above seasonal normals as weak sagging front does little to change
the air mass.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
As of 230 PM EDT Sunday: A potent packet of energy will be crossing
our forecast area (FA) Monday evening, all still tied into the NWLY
flow aloft. Meanwhile the meandering weak surface front will settle
into our southern forecast area (FA) Monday night, or just south by
Tuesday morning. Depending on how the convection works out earlier,
our trend is to decrease POPS from the west and north through Monday
night, with some low end chance in our south by daybreak Tuesday.
Tuesday appears to be an odd weather day with a surface wedge-like
configuration, while moisture tries to return to our southern and
western areas particularly on a developing east to southeast flow.
POPS will go back up, actually to likely in the afternoon, over our
east facing slopes. We have tried to have a minimum in POPS over our
northeast FA,
We then draw POPS back to slight chance in the mountains Tuesday
night, although some lingering light rain or drizzle might still be
in the cards for the far south. We will leave that out for now.
Another shot of energy will be approaching Wednesday. Although the
solutions from the various deterministic models vary on the
strength, the trend remains. We will follow with taking POPS back up
to likely in our western FA Wednesday afternoon, and chance POPS
elsewhere at this time.
Temperatures will be knocked back with the clouds and potential
precipitation, but fairly uniform with the guidance.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
As of 210 pm Sunday: Upper trough that will be impacting the region
during the short term is expected to shift east of the forecast area
Wed night/early Thursday, allowing the strengthening subtropical
ridge to build into eastern Conus from mid-to-late week. The
forecast area should be far enough displaced from the axis of the
ridge that sufficient instability and weak capping are expected to
support diurnal convection each day through the period. The main
story will be the persistent heat, as max temps in the mid-90s and
lows in the lower-to-mid 70s are expected across much of the
Piedmont and foothills through the period (around 90 in the mtn
valleys), with maximum heat indices likely reaching the 98-102 range
east of the mtns each afternoon.
&&
.AVIATION /03Z MONDAY THROUGH FRIDAY/...
At KCLT and elsewhere: VFR prevails across the FA and at all
terminals this evening, as latest radar imagery depicts isolated to
scattered showers and thunderstorms currently moving in across the
NC/TN line and northeastern GA. Per latest guidance, expect this
activity to continue it`s ESE push over the next few hours, while
losing it`s strength, especially with the loss of daytime heating.
Any -SHRA/-TSRA that reaches a terminal within the next few hours
may produce brief MVFR due to heavy downpours and gusts to near 15
kts. Though will note, do not anticipate the activity to reach KCLT.
Overnight, areas of patchy MVFR are possible, especially at KAVL and
KHKY, and across the mountain valleys. WNW winds at or below 10 kts
are expected through tonight, becoming light and variable overnight.
On Monday, expect VFR to prevail with isolated to scattered showers
and thunderstorms to return. WNW winds are expected once again,
increasing to AOB 10 kts by the afternoon hours. Anticipate any
showers and/or thunderstorms that move over a TAF site on Monday
will produce brief MVFR due to heavy downpours and possible gusty
winds.
Outlook: A slow-moving or stalled front will bring better chances
for convection starting Monday and continuing through the week.
Patchy morning fog and/or low stratus may increase as well in
mountain valleys and/or locations with wet ground.
Confidence Table...
02-08Z 08-14Z 14-20Z 20-00Z
KCLT High 100% High 100% High 100% High 93%
KGSP High 100% High 100% High 100% High 100%
KAVL High 100% High 81% High 100% High 100%
KHKY High 100% High 100% High 100% High 95%
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...None.
NC...None.
SC...None.
&&
$$
SYNOPSIS...Wimberley
NEAR TERM...SGL/WJM
SHORT TERM...TS
LONG TERM...JDL
AVIATION...SGL
Area Forecast Discussion
National Weather Service Wilmington NC
912 PM EDT Sun Jun 24 2018
.SYNOPSIS...
Hot and humid conditions will continue through Monday. Showers
and thunderstorms will become more numerous Monday and Tuesday
ahead of a cold front, which will bring some relief from the
heat for midweek. Temperatures will rebound to above normal
again late in the week, with the potential for another cold
front to approach the area on Friday.
&&
.NEAR TERM /THROUGH MONDAY/...
As of 920 PM Sunday...Multiple convective clusters are expanding
across the eastern Carolinas this evening. CAPE values in the
1000-3000 J/kg range plus a multitude of boundaries from earlier
convection should keep the radar quite active for the next
several hours. Cell motion is toward 120 degrees (southeastward)
driven by flow around a surface-500 mb ridge axis oriented
east-west across the Gulf Coast states.
A mid-level disturbance moving across the central Carolinas is
probably responsible for the current surge in activity. Models
analyze a packet of stronger 700 mb winds moving to the I-95
corridor now. As this modest mid-level jet is fed into the rear
of these developing convective clusters, strong winds will
continue to be a threat through at least midnight. Mid-level
lapse rates are climatologically poor this time of year, barely
reaching 5.5C/km (moist adiabatic) in many cases. Our current
airmass has somewhat steeper lapse rates aloft, approaching
6.5C/km, which likely explains the tenacious nature of tonight`s
storms. The HRRR has been very consistent showing convection
remaining active through midnight as it swells southeastward.
Forecast grids have been updated several times this evening.
This most recent update increases PoPs to 50-80 percent from
Kingstree to Georgetown, and also for Brunswick County where one
particularly strong cluster of storms is expected to track over
the next couple of hours. Forecast lows are in the mid 70s for
most areas, slightly cooler than earlier forecasts given the
anticipated rain-cooled airmass expected to develop or advect in
shortly.
&&
.SHORT TERM /MONDAY NIGHT THROUGH TUESDAY NIGHT/...
As of 300 PM Sunday...A potent shortwave ejecting from the main
closed low across the western U.S. will move across the area
Monday night. This along with a front at the surface further
combined with timing spells trouble in the way of a MCS and
possible severe weather across the CWA. Model guidance is in
unusual excellent agreement on these features as well. We are
maintaining likely pops for a good part of the overnight hours
as there should be a good trailing stratiform event as well. SPC
has the entire area in a Marginal Risk but cautions of a
possible upgrade in later releases. Tuesday looks wet as well
with the front lingering in the area or just to the south.
However, experience has shown that NVA in the wake of these type
of features kinda wins out so confidence is lower for Tuesday
regarding pops. At least it will be much cooler with, depending
on insolation most areas remaining below 90.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
As of 300 PM Sunday...Cold frontal boundary is progged to be
south of the forecast area Wednesday morning, though not as far
south as previous model runs. Also, ECMWF/GFS are both
indicating a weak low to develop along the remnant front,
somewhere off the South Carolina, or perhaps southeast North
Carolina coast. The 12Z GFS is quick to dissipate this feature
by Wednesday night, ahead of a 500 mb shortwave moving eastward
and off the Carolina coast on Thursday. The ECMWF is more
bullish with the development of this low, however the 12Z run
pushes it off to the northeast ahead of the 500 mb ridge which
builds eastward over the eastern U.S. late week into the
weekend. Either scenario would result in little direct impacts
on our tangible weather.
The approach of a late-week cold front will maintain the
potential for unsettled weather into the weekend, as it will
likely stall somewhere in the area. Overall, it will be
difficult to rule out some degree of shower and thunderstorm
development in the CWA during any period of the extended
forecast, however at this time, Wednesday would seem to have the
lowest chance, assuming a slightly more stable surface layer.
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
As of 00Z...VFR through the TAF valid period except vicinity
convection this evening. Have included VCTS at all TAF sites
for this evening. Confidence is low in timing and areal coverage
thus will cover with AMD`s and threat to the terminals. Showers
and thunderstorms will move offshore overnight leaving VFR and
enough wind to prevent any fog. Winds from the S/SW early this
evening will become westerly by morning.
A similar setup on Monday with S/SW winds ahead of a cold front
which will likely trigger showers and isolated TSRA during the
late morning and afternoon.
Extended Outlook...Mostly VFR. Mainly afternoon showers and
thunderstorms each day with short duration flight category
restrictions possible, except for Monday into Tuesday when a cold
front brings showers and thunderstorms.
&&
.MARINE...
NEAR TERM /THROUGH MONDAY/...
As of 920 PM Sunday...Thunderstorms near Topsail Island earlier
produced a 45 mph wind gust at a volunteer weather station along
the Intracoastal Waterway. These storms have since dissipated,
but we`re closely watching two additional clusters of
thunderstorms which will have the capability to produce
significant wind gusts over the next few hours. One cluster
will approach the Brunswick County coast and Cape Fear in the
next 60-90 minutes, while another will affect the Grand Strand
south into Georgetown closer to midnight.
Outside of thunderstorms, the synoptic wind is southwesterly
around 15 knots with gusts to 20 knots. Winds will be heavily
influenced by local thunderstorm outflow, but should gradually
veer more westerly with time and diminish in speed toward
sunrise. The CORMP buoy array near Cape Fear shows 3-4 foot seas
occurring currently.
SHORT TERM /MONDAY NIGHT THROUGH TUESDAY NIGHT/...
As of 300 PM Sunday...Erratic wind fields expected through most
of the period as a cold front will make a push south with
plenty of convection (MCS) while it is doing so. The best we can
do with the forecast (low confidence) is initial southwest
winds of 15-20 knots followed by basically "all of the above"
directions from southwest across southern zones to northeast
northern zones and east in between. A good consistent northeast
flow doesn`t develop until the very end of the period albeit
with light wind speeds. Significant seas generally 2-4 feet.
LONG TERM /WEDNESDAY THROUGH FRIDAY/...
As of 300 PM Sunday...A frontal boundary is expected to be
south of the waters early Wednesday, resulting in light
northerly flow, at least into early afternoon, and a minimal
amount of shower and thunderstorm activity expected. The front
will wash out Wednesday night, with a return to southerly flow
by Wednesday evening. Weak low pressure along the boundary will
lift off to the northeast with minimal direct impacts expected
across area waters at this time, other than briefly reinforcing
the northerly flow on Wednesday. Models have been having trouble
coming into agreement on this feature, so overall confidence
associated with it remains low. Another frontal boundary will
drop south into the Carolinas on Friday, but at this time it
appears it will stall inland. Potential for scattered showers
and thunderstorms will increase Thursday and Friday.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...None.
NC...None.
MARINE...None.
&&
$$
SYNOPSIS...CRM
NEAR TERM...TRA
SHORT TERM...SHK
LONG TERM...CRM
AVIATION...MRR
Area Forecast Discussion...UPDATED
National Weather Service Jackson MS
833 PM CDT Sun Jun 24 2018
.UPDATE...
Updated for evening discussion.
&&
.DISCUSSION...
Some of the latest CAM guidance is having problems resolving the
convection approaching out of AR, especially with the southern
extent. This convection continues marching east in a zone of high
low level theta-e which should help maintain it as it moves into
the ArkLaMiss Delta region over the next few hours. Have updated
pops in these areas to account for the increased likelihood of
being impacted./26/
Prior discussion below:
Tonight and tomorrow...
The primary focus will be for the build up of heat and humidity
for heat stress levels for Monday and limited chances of diurnal
convection.
Latest rap and satellite imagery showed an outflow boundary crossing
the region from a former morning MCS that came out of Arkansas.
It was triggering some isolated showers and thunderstorms across
the region. There was also a 2nd MCS over OK moving to the east.
Expect the activity to diminish during the early evening hours.
Models and CAM guidance hint at the second MCS moving over the
Midsouth region overnight. So coordinated with MEG on low
overnight pops in our northern counties to account for this.
Midshift will have to monitor for any outflows from that feature
which may affect our northern counties. For Monday expect build of
heat and humidity which will push our heat indices around the 105
degree mark. Will hold of on any heat advisory for now for
Monday.
As far as lows concern readings will be in the lower to middle 70s
as well as highs in the lower to middle 90s./17/
Monday night through the week...
The main story will be of the increasing heat and humidity across
the region through the week. Models continue to agree that the upper
ridge will be centered around the region, which will allow for
afternoon highs to reach into the lower and mid 90s. Low level
moisture will be in place, which could lead to some shower and
thunderstorm activity during the afternoons across the eastern and
southern sections of the ArkLaMiss. Given the blocking ridge in
place, any organized storm systems should remain well north of the
region. However, this low level moisture present will allow
dewpoints to reach into the lower and mid 70s. This, coupled with
highs in the 90s, will allow for heat indices to reach into the 100-
107 degree range. It appears this trend will continue, and thus heat
advisories will likely need to be issued for much of this week. Will
continue to mention this limited risk in the HWO and graphics. As
mentioned, the diurnal storm chances could bring some relief in
dropping temperatures in the afternoon for a lucky few, but will
keep muggy conditions in place. Overnight lows won`t provide a huge
amount of relief as lows are forecast to be in the lower to mid 70s.
/28/
&&
.AVIATION...
00Z TAF discussion:
Although isolated thunderstorms will continue across the region
until around midnight, most TAF sites will not see these
conditions. Thus, VFR conditions will prevail through the
period./26/
&&
.PRELIMINARY POINT TEMPS/POPS...
Jackson 75 97 74 94 / 13 4 3 15
Meridian 77 98 74 96 / 11 17 4 27
Vicksburg 75 96 74 94 / 17 5 3 8
Hattiesburg 75 97 74 94 / 8 16 6 28
Natchez 75 95 73 93 / 11 5 2 13
Greenville 74 95 74 94 / 24 4 2 4
Greenwood 75 95 74 94 / 17 4 2 7
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...None.
LA...None.
AR...None.
&&
$$
AREA FORECAST DISCUSSION
National Weather Service Jackson KY
1100 PM EDT Sun Jun 24 2018
.UPDATE...
Issued at 1100 PM EDT SUN JUN 24 2018
Forecast seems to be in good shape late this evening. Convection
has ceased across the southern CWA and south-central KY. Latest
HiResARW and NMM have come in and are more in line with the last
few runs of the HRRR, which brings precip into the CWA between 6
and 8Z, and spreads across much of the northern CWA through the
morning, while the far southern CWA may remain dry. More scattered
to numerous convection then develops throughout the day for the
remainder of the CWA. Did not end up changing pops for the
overnight in the south, as it would be better to see how things
are starting to materialize as convection nears closer, and we are
in good agreement with our neighboring offices. Will continue to
monitor and update as needed throughout the overnight. Also loaded
in the latest observations for temps, dew points, and winds to
make sure they were on track with the near term forecast. All
updates were published and sent to NDFD/web.
UPDATE Issued at 801 PM EDT SUN JUN 24 2018
The convection across the southern CWA has extended a bit farther
into the evening than originally forecast. We ahead and extended
pops by several hours, with convection expected to continue
deteriorating over the next 1 to 2 hours. As for the overnight,
latest CAMs are now suggesting that the next wave of showers and
thunderstorms won`t make it into the area until after 6Z in the
north and close to dawn for portions of the southern CWA. This is
several hours, at least, slower than previous runs and the ongoing
forecast. This may lead to some pop/weather adjustments for the
overnight forecast within the next hour or two. Otherwise, all
updates (including a refresh to temps and winds) have been
published and sent to NDFD/web. A new forecast package will be
sent out once pops/weather have been updated.
&&
.SHORT TERM...(This evening through Monday night)
Issued at 440 PM EDT SUN JUN 24 2018
20z sfc analysis shows a stalled frontal boundary across eastern
Kentucky while the pressure pattern is quite weak. In this
environment shower and storms were plentiful early in the day but
a lull ensued with mainly just some very light showers around
through the bulk of the day. This is starting to change now though
with the development of a line of storms - strong to severe - to
the southwest that should propagate east into our southern tier
through the remainder of the afternoon - per the latest runs of
the HRRR. Meanwhile, the earlier clouds broke up enough and became
cellular allowing the heating to reach the sfc with temperatures
reaching the mid to upper 80s while dewpoints remain quite high in
the upper 60s and lower 70s. Aside from the showers and storms
winds have generally been light and variable, though they have
picked up with deeper mixing this afternoon and are now running
west to northwest at 10 to 15 mph.
The models are only in fair agreement aloft through the short
term portion of the forecast. Right off the bat they deal
differently with the MCV moving east along the Ohio River this
evening with the Canadian weaker than the NAM and GFS. This
feature then progresses east and weakens tonight - riding along
the northern fringe of the southern 5h ridge. The remains of this
wave departs to the east later Monday afternoon as the ridge
rebuilds into the state ahead of a larger closed low trough coming
out of the Central Plains. This latter feature is poorly handled,
as well, with the NAM furthest north compared to the ECMWF and
GFS. Ridging should hold for eastern Kentucky into Tuesday morning
as the low approaches. Given the mesoscale nature of the key
elements aloft affecting the forecast - did start with a blended
solution for the grids, but leaned heavily on the last several
runs of the HRRR for details tonight into Monday morning.
Sensible weather will feature some activity in the far south
through the rest of the afternoon and into the early evening - a
few of the storms that develop could become strong or even severe
with gusty and damaging winds the main threat. Later in the
evening, the remnants of an MCS to the west should be fading out
as it moves into the area, though there is a chance it holds
together with a threat for showers and thunderstorms to continue
through the evening and past midnight. More likely, and in line
with the HRRR, the next iteration of MCS will develop to the west
of JKL`s CWA and press into the area late tonight with more
sustained showers and thunderstorms. This will bring heavy rains
with the strongest storms and training will be a concern for
localized flooding - especially as PWS approach 2.0 inches - late
tonight into the day Monday. Perhaps a subsequent MCS will
develop and continue to affect eastern Kentucky into the day
Monday before that energy aloft moves on to the east and
convection should settle down. Will highlight the storm chances
and heavy rain threat in the HWO as well as messaging in the
weather story. Later shifts may have confidence to go with a flood
watch for this MCS activity but for now will forego headlines.
Quieter weather commences Monday night with the expectation of
patchy fog, mainly in the valleys, late. Temperatures both nights
will be very mild with muggy dewpoints in place and only a
small difference between ridges and valleys.
Used the CONSShort and ShortBlend as the starting point for all
the grids with minimal adjustments to temperatures through the
short term portion of the forecast owing to the high dewpoints. As
for PoPs, adjusted them in favor of the HRRR depiction for the
specifics tonight into Monday.
.LONG TERM...(Tuesday through Sunday)
Issued at 320 PM EDT SUN JUN 24 2018
A shortwave trough will slowly push east through the middle
portion of the week, keeping the weather unsettled from Tuesday
through Wednesday night. Still some questions on how long
precipitation chances linger into the end of the week, but will
maintain a dry forecast for now with the lack of better forcing in
play. Summer like temperatures will make a big return late in the
week into next weekend with heat index readings exceeding 100 each
afternoon from Friday onward. Will maintain a mention in the HWO
for the heat. Heat advisories could be needed at some point next
weekend. While an afternoon shower may be possible Saturday or
Sunday in the high terrain, the cap will likely be too strong to
see much activity.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
ISSUED AT 815 PM EDT SUN JUN 24 2018
After convection impacted KLOZ and KSME earlier this evening,
expect VFR conditions to persist at all TAF sites through the
remainder of the evening. Confidence starts to lower a bit for the
overnight period. Previous forecast and hi-res models showed a
potential MCS bringing another round of showers/storms with
attendant low CIGS and VIS possible for the TAF sites overnight
and continuing through much of the day tomorrow. While this will
still likely be the case, the latest hi-res models are now showing
the system setting up farther north and maybe several hours
later. This will change the timing of impacts at each TAF site.
However, this convective development is highly dependent on the
upstream evolution of storm clusters that have not even formed
yet. Accordingly, will continue to monitor this situation and
will update TAF timing/impacts as necessary. Went with SHRA and
VCTS for the likely pops in place through tomorrow, with MVFR VIS
and CIGS. However, ultimately expect conditions to fluctuate
between VFR and IFR (or potentially lower in the heaviest storms).
Through the period, winds are expected to be relatively light and
variable outside of thunderstorms.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JMW
SHORT TERM...GREIF
LONG TERM...KAS
AVIATION...JMW
Area Forecast Discussion...UPDATED
National Weather Service Lubbock TX
927 PM CDT Sun Jun 24 2018
.UPDATE...
We have expired the heat advisory as well as trimmed PoPs/Wx and
adjusted several other near term grids.
A strong outflow boundary, dryline and intense heating were not
enough to overcome an impressive cap across the South Plains this
afternoon and evening. Temperatures peaked at a scorching 105 to
110 degrees over much of the central and southern South and
Rolling Plains. Officially Lubbock reached 108 degrees, just 2
degrees from the record set back in 1990. The hottest temperature
in our CWA was at Lake Alan Henry where it hit 112 degrees.
The heat was sufficient to break the cap across the eastern
Permian Basin and Big Country where a few stronger storms have
developed. This activity will largely stay to our south before
diminishing later tonight, though it could still seed a rogue
shower/storm into the southern Rolling Plains late this evening.
Hence we have maintained a minimal thunder mention over the
southern Rolling Plains through 06Z.
Otherwise, our attention turns to the north as the next MCS is
already well underway across southeast CO into western KS, with
recent development on its southern flank into the OK Panhandle.
Lastly, isolated convection has recently tried to develop just
east of Fort Sumner. If this activity can persist it could move
into our northwestern zones later tonight. Although the MCS
currently appears to be propagating mostly eastward, recent RAP
and HRRR runs continue to suggest an outflow aided front along
with glancing lift from the upper low emerging across the central
High Plains will be enough to spur additional convective
development southward through much of the western Texas Panhandle
over the next few hours. This seems plausible given the
strengthening southerly to southeasterly LLJ. Eventually the cap
and growing displacement from the upper support should thwart the
southward development of convection, though the southern flank of
the MCS could skirt our far northern zones. Should this happen,
the southern Texas Panhandle counties could see strong to severe
wind gusts, marginally severe hail and brief heavy rain before
the activity quickly shifts eastward toward dawn Monday. Hence, we
have trimmed the southern extent of mentionable PoPs, though we
have maintained solid chance values across the northern/northeastern
zones from 06-12Z.
Outside of storm chances through tonight, the main story will be
the "cold" front which will help knock temperatures back close to
average on Monday.
&&
.PREV DISCUSSION... /issued 643 PM CDT Sun Jun 24 2018/
AVIATION...
Outflow has passed south of KPVW and KCDS with gusty easterly
winds in its wake. The outflow and/or retreating dryline should
bring gusty southeast winds to KLBB in the next couple of hours.
An isolated storm could still develop on these boundaries and
affect any of the terminals this evening, though current trends
don`t look favorable for this. Instead, the winds may back more
southeast to southerly as a stout southerly LLJ cranks up.
However, an outflow aided cold front will then follow moving
through the terminals after midnight. Current guess has the FROPA
around 07Z at KPVW and KCDS and 08Z at KLBB, though this could
change a bit either way, depending on the magnitude of the outflow
push. Gusty northerly to northeasterly winds will follow the
FROPA. In addition, there is a chance the convective complex
moving across the Panhandles could graze the northern terminals,
KCDS appears to have the best chance of being impacted and we have
included a VCTS for now. The post-frontal winds will gradually
ease through the day on Monday, but a period of sub-VFR ceilings
look like a decent bet at the terminals.
PREV DISCUSSION... /issued 349 PM CDT Sun Jun 24 2018/
DISCUSSION...
Outflow boundary from storms passing through central Oklahoma
today has been stronger than previously forecast. As such it has
stabilized areas in the Panhandle and northeast Rolling Plains.
Also, dryline has pushed east through most of the South Plains.
For this afternoon main concern is over the Rolling Plains along
and south of the boundary...threatening areas from Guthrie
southward. Very warm middle atmosphere temperatures...around 16C
at 700mb...working as strong cap. As such, remains questionable as
to whether or not convection will break through the cap forming
storms. If they do form, convective potential energy is very high
and as such storms could produce damaging wind gusts.
Overnight tonight...vorticity max passing around southern edge of
an upper low moving SE into Nebraska is expected to form complex
of storms over eastern Colorado that should move southeast through
parts of the Panhandle and possibly parts of our forecast area.
Developing low level jet over Rolling Plains and eastern South
Plains should feed strong moisture plume into the storms overnight
keeping the storms going. Main question will be how far south the
area of storms will extend. Other than the southeast Panhandle,
the chances of overnight storms should be 20 percent or less.
The complex of storms to our north overnight will drive a
front/boundary well south through the area for tomorrow. As such
temperatures across the South Plains are forecast to be somewhat
cooler than today with highs mostly in the 90s. The remaining
boundary will leave the area with a slight chance of storms Monday
night extending from southern Oklahoma back through the Rolling
Plains into the South Plains.
For Tuesday and on through the remainder of the week, the upper
high will rebuild over the area providing mostly dry weather with
rain chances generally well below 20 percent. Temperatures will
remain on the hot side with highs from the mid 90s to near 102.
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
23
Area Forecast Discussion
National Weather Service Memphis TN
900 PM CDT Sun Jun 24 2018
.DISCUSSION...GOES-16 Water Vapor/Infrared satellite trends
indicate a Mesoscale Convective System (MCS) transitioning into a
Mesoscale Convective Vortex (MCV) across Arkansas this evening.
Showers and thunderstorms associated with this MCV is beginning to
approach Eastern Arkansas. Surface based CAPE values across the
Mid-South this evening are in the 2000-3500 J/kg range with a
small amount of Convective Inhibition present, and 0-6 km Bulk
Shear values between 30-40 kts with the highest values near the
MO/KY border. Short term models have been struggling with the
overall evolution of this evening`s convective activity and thus
leaning towards the HRRR solution for the remainder of the night.
A few strong thunderstorms to perhaps a severe thunderstorm or
two is still possible tonight.
Will make some adjustments to rain chances for the remainder of
the night and any other elements as necessary.
CJC
&&
.PREV DISCUSSION... /issued 705 PM CDT Sun Jun 24 2018/
DISCUSSION...
Updated for aviation discussion
PREV DISCUSSION... /issued 233 PM CDT Sun Jun 24 2018/
Currently through tonight...atmosphere recovering once again from
early morning convection with SPC mesoanalysis showing 2000 to
2500 j/kg of CAPE area wide and up to 50 kts of effective bulk
shear across the northwest counties. Cloud cover and morning
convection has kept temperatures down over the far northwest
counties...with mid 80s to low 90`s elsewhere. On satellite MCV in
southwest Missouri slowly advancing east providing the shear and
the anticipated trigger for new development...but when? HRRR
showing a line of storms forming before sunset in north central
Arkansas and tracking through the CWA with a strong potential of
backbuilding of storms through the night. Thus there may be a
greater area for localized flash flooding along and north of I-40
in addition to another threat for damaging wind gusts.
Monday through Wednesday...models showing the next shortwave to
quickly drop into the Central Plains tomorrow...then slowly
making its way to the Central Great Lakes by Wednesday. This
feature will keep a westerly component in the mid and upper level
winds...so the threat for convection will persist across most of
the Midsouth with the exception of the far southwest Delta
counties. Temperatures this period will range from near 90F in
the far northeast to the mid 90s in the west...where heat indices
could reach 105F both Tuesday and Wednesday. Lows in the 70s.
Thursday through next weekend...the GFS and EURO getting on a
better page with the amplification of the upper ridge over eastern
third of the nation. More widespread mid 90`s with a few upper
90`s...coupled with mid 70 dewpoints will yield likely heat
advisories for the entire Midsouth. Some relief will be seen though
as the high center drifts north of the Ohio Valley. Stronger
midlevel easterlies will bring better diurnal rain chances to the
eastern counties Thursday and Friday and then the entire Midsouth
later next weekend.
JAB
&&
.AVIATION...
The pattern remains conducive for convective development
overnight. Monitoring the evolution of the complex in western
Arkansas. Latest hi-res guidance brings that complex into the
western part of the Mid-South by 04z and through KMEM around 05z
and east to KTUP around 07z. Expect some gusty winds as the storms
roll through otherwise light south winds overnight. Shortwave
upper level ridging builds in on Monday which should limit
convection across the Mid-South. Southwest winds at 7-10 kts
expected Monday with higher gusts at KMEM and KJBR.
SJM
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...None.
MO...None.
MS...None.
TN...None.
&&
$$
Area Forecast Discussion
National Weather Service Miami FL
840 PM EDT Sun Jun 24 2018
.UPDATE...
Showers with isolated storms continue over the Gulf waters,
Atlantic waters off Palm Beach, and some of the northern half of
South Florida. Recent HRRR runs are going kind of crazy showing
plenty of rain over South Florida overnight. Although the HRRR is
undoubtedly overdoing it...it did initialize fairly well, and the
atmosphere over South Florida is quite moist. Other models also
show a few periods of isolated to scattered activity overnight.
Furthermore, the northern end of a westward moving Caribbean tropical
wave is over Cuba near our longitude and is helping to enhance
moisture over South Florida, as viewed from CIMSS TPW imagery.
Given all of the aforementioned factors, I am forced to raise PoPs
slightly overnight for this update. Basically, after 11pm, we
have now have 20 PoPs for most inland and western areas for most
of the night with 30s for the east coast. Therefore, there is a
slightly higher chance of overnight showers over land tonight
compared with previous nights, and this is mainly due to enhanced
moisture from the tropical wave.
&&
.PREV DISCUSSION... /issued 722 PM EDT Sun Jun 24 2018/
AVIATION...
The winds will be light and variable tonight over all of the taf
sites before going easterly around 10 knots after 14Z on Monday.
The only exception is at KAPF taf site where the winds will become
westerly after 18Z on Monday. VCSH will remain in the forecast
until 02Z tonight, before going dry for rest of the night hours
tonight. VCHS will then be back in the taf sites after 14Z on
Monday, except for KAPF taf site where VCTS will begin after 18Z
on Monday. The ceiling and vis will remain in VFR conditions
tonight into Monday, but could fall into MVFR conditions with any
passing shower or thunderstorm.
AVIATION...54/BNB
PREV DISCUSSION... /issued 359 PM EDT Sun Jun 24 2018/
DISCUSSION...This afternoon through Tuesday night: A weak
surface ridge over the northeastern Gulf will cause winds over
South Florida to be east-southeast through Monday. This flow will
bring conditions that are quite moist. On Tuesday, the ridging
over the northeastern Gulf weakens and moves north, leaving very
light to calm winds on Tuesday. We still expect conditions to be
quite moist on Tuesday as well. During this time, expect east
coast sea breeze to spark showers and storms in the eastern half
of the peninsula in the early afternoon, with the bulk of the
activity over the western half of the peninsula towards late
afternoon. Showers and storms will be favored over land during the
daytime hours, with scattered nocturnal storms over the Atlantic
and Gulf waters, although there is a higher chance of nighttime
activity over the Atlantic than the Gulf. Generally the storms the
next couple days should be typical summertime pulse storms. With
high freezing levels and warm conditions aloft, hail won`t be a
concern. Brief gusty winds and some isolated street flooding are
possible with the heavier activity along with frequent lightning.
High temperatures the next couple of days will be near normal,
especially for the east coast, due to the moist conditions,
numerous showers and storms, and easterly flow. West coast may be
a little warmer than normal in the early afternoon before the
storms arrive.
Long term (Wednesday through next weekend): Weak southeast flow will
continue as a weak ridge is nearly directly overhead or just to our
north. This will keep the same pattern of showers and storms moving
gradually from east to west through the day, with some nocturnal
activity possible over the water. Guidance indicates the
possibility of some dry Saharan Air moving near or over South
Florida late in the week. If this materializes, then it would
decrease the rain chances over South Florida. Therefore, I
decreased PoPs for the southern half of South Florida by about 10
percent from the previous forecast package Wednesday night through
Friday. High temperatures are likely to be above normal for
western areas mid to lake week with heat index values possibly
over 105 in spots.
MARINE...
Southeasterly to easterly wind flow will continue through the
week. We will see scattered nighttime and isolated daytime
showers and thunderstorms over the South Florida waters for the
next several days. Sea will be generally 2 feet or less. Locally
higher seas and gusty winds are possible with any gusty showers or
thunderstorms.
&&
.PRELIMINARY POINT TEMPS/POPS...
West Palm Beach 77 89 77 91 / 40 50 30 40
Fort Lauderdale 79 88 79 90 / 30 60 30 50
Miami 78 88 79 90 / 30 60 20 50
Naples 77 90 76 91 / 40 60 30 50
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...None.
AM...None.
GM...None.
&&
UPDATE...98/ABH
DISCUSSION...98/ABH
MARINE...98/ABH
AVIATION...54/BNB