Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 06/12/17
Area Forecast Discussion
National Weather Service Gaylord MI
1145 PM EDT Sun Jun 11 2017
.UPDATE...
Issued at 937 PM EDT Sun Jun 11 2017
Slow-moving cold front remains just upstream of our CWA...
extending thru Upper Michigan into NW Wisconsin. Elongated area of
convection continues to fire along this boundary...with strong/svr
storms from the Western Upper Michigan/Wisconsin border into
portions of far Northern and NW Wisconsin. Wind remains the
primary threat given freezing levels are now at 14,700 ft per 00Z
APX observed sounding. All short term models try to steadily
diminish this convection both in areal coverage and intensity as
it moves into the NW half of our CWA overnight...with highest POPs
still expected over Eastern Upper Michigan. Still a marginal
chance for a severe storm overnight...but certainly better
instability and 850 mb theta E ridging will stay just west of our
CWA...a scenario that agrees with updated SPC Day 1 outlook.
Current forecast is handling the situation well...no changes
needed attm.
&&
.NEAR TERM...(Tonight through Monday)
Issued at 343 PM EDT Sun Jun 11 2017
...Severe threat over the next few hours...
Time/active wx precludes an especially lengthy discussion this
afternoon.
Incoming MCS has deteriorated somewhat, but has a lot of forward
momentum, and some interesting bookend vortex/MCV dynamics to help
things along. Instability gradient lies a bit north of the M-32
corridor, with eastern upper MI actually quite stable (dew points
in the upper 40s in spots. Activity will have to feed off
instability advecting in from the sw, while still staying north of
the strong cap in places in southern sections and points south.
Won`t be much of a lull behind this MCS before additional
convection returns. In fact, at the moment there is no lull, with
several linear convective segments in nw WI and central MN. Low
pressure near Hudson Bay will eventually drag a cold front thru
eastern upper MI late tonight, and the rest of northern MI
(barely) on Monday. Shower/t-storm threat will accompany the
slow-moving front, migrating southward with time. Precip threat
will persist north of the front, thanks to 850mb theta-e advection
across the frontal surface. Pops will thus not exit the forecast
area tomorrow; in fact, chancy pops in order across most of
northern lower MI thru the end of the day.
Svr potential (outside of the next few hours) looks to be
isolated, but certainly isn`t nil. HRRR runs showing multiple
linear structures moving thru tonight, with an attendant low-end
wind/hail threat. Ability to recharge for tomorrow ahead of the
front will be somewhat limited by cloud cover, with best sunshine
south of the forecast area and beneath the capping EML.
Min temps tonight very warm in northern lower, lower 60s to around
70f, with upper 50s in eastern upper. Max temps Monday in the 70s
in eastern and far northern lower, mainly 80s south of M-68, with
Gladwin perhaps taking a run at 90f.
&&
.SHORT TERM...(Monday night through Wednesday)
Issued at 343 PM EDT Sun Jun 11 2017
...Remaining warm with continued shower and thunderstorm chances...
High impact weather potential: Scattered thunderstorms possible at
times.
Pattern forecast: Flat upper level ridging/zonal flow to start the
forecast period will gradually amplify by late Tuesday in
association with closed upper level low pressure moving
northeastward through the Intermountain West. A moist/humid airmass
will remain in place through the middle of the week, especially
along and south of a nearly stationary boundary expected to be
draped from the northern plains through roughly the M-32 corridor by
Monday night. This boundary will be the focus for additional
scattered shower and thunderstorm development as it gradually sags
southward toward the M-72 corridor during the day Tuesday before
reorienting in a more NW to SE fashion Tuesday night through
Wednesday as the boundary gradually lifts back north. A few subtle
mid level impulses should provide additional support at various
times, again mainly across sections of northern Lower through
midweek. A potent cold front is scheduled to cross the region late
in the day Thursday, which should bring an end (at least
temporarily) to the unsettled conditions locally.
Primary forecast concerns/challenges: Timing and location of PoPs
through the period, along with gauging severe weather potential.
Sufficient moisture will continue across the region, mainly along
and south of the quasi-stationary boundary, with PWs greater than
1.50 inches Monday night through Tuesday. Deep layer moisture
diminishes somewhat during the day Wednesday before pooling again
pre-cold frontal passage Thursday. Expecting scattered showers and
thunderstorms to be commonplace along and south of the boundary
Monday night through Tuesday, leaving eastern Upper dry under partly
sunny skies and the highest PoPs limited to along and south of M-32.
Any severe weather potential Tuesday looks rather limited, but a
conditional risk does exist based on timing of additional support
provided by mid level impulses colocated with the greatest modeled
instability (500 - 1,500 J/kg of MLCAPE) situated across far
southwestern sections of the forecast area. At this juncture, any
isolated strong-severe storms looks to be confined to along and west
of US-131. Overall, not a complete washout Tuesday by any stretch,
but there will be various periods of showers and storms (potentially
heavy at times) to contend with. Decent temperature gradient is also
expected with highs in the low-mid 70s across eastern Upper warming
to the low-mid 80s with mid-60s dew points across the far southwest.
Well-advertised boundary gradually reorients in a more northwest-
southeast fashion across the forecast area by Tuesday evening with
high amplitude ridging become centered overhead Wednesday morning.
Additional scattered showers and thunderstorms are expected to
plague northern Michigan at various times throughout the day, but
again, far from a complete washout. Can`t completely rule out
another conditional and low end severe weather threat, but by far
the better threat looks to be focused to our west associated with
the cold front, which is supported well by SPC`s Day 4 outlook.
Similar high temp spread across the area Wednesday with near 70
north to the low-mid 80s far southwest.
.LONG TERM...(Wednesday night through Sunday)
Issued at 343 PM EDT Sun Jun 11 2017
Thunderstorm chances will continue into Thursday until a cold front
pushes through, settling things down at least briefly. Moisture
return should be fairly quick, with broad high pressure over the SE
advecting Gulf moisture north and a zonal jet over the northern tier
of states adding some Pacific moisture as well. With the broad upper
low still over the Hudson Bay region, it is not out of the question
some shortwave impulses could kick off some more showers over the
weekend. Temperatures will run above normal for most of the period,
cooling to more near normal levels by Sunday.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 1145 PM EDT Sun Jun 11 2017
A cold front will slowly slide thru Northern Michigan tonight
into Monday...stalling just south of our area by Monday afternoon.
Scattered showers and thunderstorms will impact Northern Lower
Michigan overnight thru Monday along this boundary. Conditions
will generally remain VFR overnight...but will drop to MVFR for
some locations on Monday just behind that boundary. LLWS will
continue to impact TVC and MBL overnight just ahead of the front.
&&
.MARINE...
Issued at 343 PM EDT Sun Jun 11 2017
Brief uptick in southerly winds expected on some waters late
tonight into Mon morning, particularly on our southern waters
(south of Gd Trav Light and Alpena). Not anticipating this
requiring further advisories for now, but will of course monitor.
Low pressure transiting Hudson Bay will drag a cold front south
across northern MI, cutting that southerly flow off, but
supporting showers/t-storms. Light northerly winds will move in
behind that front late Monday and Monday night.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&
$$
UPDATE...MLR
NEAR TERM...JZ
SHORT TERM...MJG
LONG TERM...ALM
AVIATION...MLR
MARINE...JZ
Area Forecast Discussion
National Weather Service Caribou ME
958 PM EDT Sun Jun 11 2017
.SYNOPSIS...
A weak cold front will cross the area this evening and stall
across the region overnight. The front will lift north as a warm
front on Monday as a weather disturbance tracks across the area
from the west. A cold front cross the area Monday night.
&&
.NEAR TERM /THROUGH MONDAY/...
10 pm update...
Frontal bndry currently sits from a Littleton-Patten-Jackman
line as of 01z. Dwpts to the north are in the u40s/l50s while
to the south of bndry they rmn arnd 60F. Winds hv diminished ovr
the past hr and expect they wl continue to lighten thru the
ovrngt bfr bcmg lgt/vrb around daybreak.
Latest HRRR guidance indicates showers wl lkly mv into nrn zones
shortly aft daybreak, lkly being forced by vort max just to the
north of Lk Ontario per latest WV imagery. This has the
potential to impact convective chcs acrs the CWA tomorrow aftn
by stabilizing airmass acrs the north or allowing differential
htg bndry to dvlp somewhere acrs the area and enhance potential.
Either way potential exists for strong storms in the aftn with
CAPES appchg 1200 J/KG.
Prev discussion blo...
Winds will diminish this evening as a weakening cold front moves
into the area and stalls. Tonight will then bring some cooling
across the north with lows dropping into the low 50s, but be
warm Downeast with lows in the low to mid 60s. Some fog may form
near coastal areas as the wind lightens. A weather disturbance
approaching from the west will then lift the stalled front north
as a warm front on Monday. Model soundings are showing strong
capes, up to 2K G/KG, over central areas with lower capes
across the north. Thunderstorms will be likely as this system
crosses the area Tuesday with the best chances for strong storms
across the central and interior Downeast part of the region.
Will mention gusty winds and small hail with the storms during
the mid to late afternoon from central areas south to interior
Downeast locations.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
A cold front is expected to push to the south of the region
Tuesday. At the same time strong high pressure will build in
behind the cold front through Tuesday night and Wednesday
bringing dry conditions to the State. Cooler temperatures are
expected during the day Wednesday as the cooler airmass moves
across the northeast.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
Strong high pressure is expected to moves across New England
during the day Thursday bringing continued dry weather to the
region. The high will then move to the east of the region into
the Atlantic Thursday Night. Showers are expected to develop
Friday and continue into Saturday as moisture moves northward in
the return flow on the west side of the high. A cold front will
approach from the west Sunday and cross the region Sunday Night
and Monday with more showers expected. More showers are expected
Tuesday as an upper level low pressure system passes to the
north of the State.
&&
.AVIATION /02Z MONDAY THROUGH FRIDAY/...
NEAR TERM: VFR next 24 hours at all terminals. Mid-deck will
move in around 12z from the west and may put damper on
convection expected tomorrow afternoon, thus have just mentioned
VCSH/VCTS at terminals north of BGR.
SHORT TERM: VFR conditions are expected Tuesday through Friday.
&&
.MARINE...
NEAR TERM: Winds will drop below SCA tonight and remain below
SCA on Monday. Some fog may limit visibilities on the waters
late tonight as winds diminish.
SHORT TERM: Have used the NAM to for wind grids. For Waves: The
primary wave system from Tuesday into the weekend is expected to
be southerly wind wave. Will use the Nearshore Wave Prediction
System for wave heights through Wednesday then transition to the
Wave Watch III.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...None.
MARINE...Small Craft Advisory until 1 AM EDT Monday for ANZ050-051.
&&
$$
Near Term...Bloomer/Farrar
Short Term...Mignone
Long Term...Mignone
Aviation...Bloomer/Farrar/Mignone
Marine...Bloomer/Farrar/Mignone
Area Forecast Discussion
National Weather Service Cheyenne WY
621 PM MDT Sun Jun 11 2017
.SHORT TERM...(This evening through Monday Night)
Issued at 154 PM MDT Sun Jun 11 2017
...Widespread Severe Weather Outbreak Likely on Monday...Including
Potential for Several Tornadoes...Very Large Hail...and Damaging
Winds...
The main focus over the next 24-36 hours will be a higher-end threat
for severe weather on Monday. However, there is some potential for a
few severe storms this evening as a mid-level shortwave lifts to the
northeast across the CWA. Increasing low-level moisture, combined w/
considerable warm advection aloft should yield the development of at
least isolated thunderstorms in the vicinity of the Laramie Range by
21z-00z, and perhaps the Snowy Range and adjacent Laramie Valley too
with enhanced low-level convergence in that area. If a storm were to
form near Laramie, RAP soundings suggest decent shear w/good veering
and increasing winds with height and around 1000 J/kg CAPE. A threat
for severe hail/wind, or possibly a tornado is there. Elsewhere, SPC
mesoanalysis shows excellent deep layer vertical shear and 1000-2000
J/kg CAPE which may support supercells with storms that develop. Not
much of a window for development though as soundings show only an hr
or two where the low-level inversion weakens sufficiently. Will need
to watch areas along/se of a line from CYS-AIA between 03z-09z w/low
level warm advection and a strong mid-level vort max progged to lift
across northeast CO and the southern NE Panhandle overnight.
Eventually, surface winds are expected to veer to the southeast from
their current northeasterly direction over the high plains. However,
any convective activity could impact low-level wind fields and delay
this until close to 12z Monday. That said, fog and low-level stratus
may not be as significant on Monday AM as earlier thought, but opted
to keep patchy fog in the grids between 09z-15z. Models are in quite
good agreement w/forecast soundings showing rapid erosion of low-lvl
stratus by mid-morning.
Our attention then shifts to what very well could be one of the most
significant severe weather episodes we have seen in recent years for
southeast WY and the western NE Panhandle. Models have been in great
agreement over the last several days w/ a significant upper low over
the Great Basin/Intermountain West at 00z Tuesday. The net result is
impressive upper-level difluence over the entire area along with sfc
cyclogenesis over northern CO. This 992 mb low then proceeds to lift
NNE across southeast WY and western NE through the day, which should
be a classic track for a potential tornado event. Thunderstorms will
become numerous along/e of the Laramie Range by 00z with the help of
low-level upslope, excellent convergence along w/steadily increasing
large scale ascent. Biggest remaining question is storm mode as some
models have trended toward a weak, almost negligable cap with no CIN
to be had which could be messy with too much forcing. However, GFS &
NAM soundings both show at least a shallow low-level inversion at 5k
feet AGL or so which could promote discrete cells early. It also may
help that the stronger dynamic support does not arrive until late in
the afternoon which could keep early storms from merging too quickly
and limiting storm intensity to some degree. By mid/late evening, we
expect storms to merge into one or more clusters across east central
WY or the northern NE Panhandle.
This convection, especially if discrete, will be associated w/a high
threat for severe weather. Steep mid-level lapse rates, coupled with
strong surface heating is expected to yield a moderately to strongly
unstable air mass characterized by MLCAPE over 2000 J/kg. Impressive
forecast soundings remain with 0-6 km shear over 50 knots across all
of our high plains zones. Very large, curved, and even a few sickle-
like hodographs are common along/n of the warm front between 00z-03z
as the low-level jet rapidly strengthens with 50 knot flow at 850 mb
and resulting 0-1 km/effective SRH over 400 m2/s2. This will support
intense supercells with low-level mesocyclones, likely being capable
of all facets of severe weather including tornadoes, extremely large
and damaging hail, flash flooding, and destructive winds. Any storms
which can become rooted in the boundary layer by evening will almost
certainly have the potential to produce a strong/violent, long-track
tornado given 0-1 km EHI of 2-4. SREF and NCAR Ensembles suggest STP
values of 3+ as well, which is impressive. Dew points in the 60s may
help promote low LCLs under 1000 meters, perhaps under 500 meters in
the early evening. Expect this to support a threat for tornadoes, as
long as the storm mode can at least stay quasi-discrete.
.LONG TERM...(Tuesday through Sunday)
Issued at 230 PM MDT Sun Jun 11 2017
All models show a much cooler day on Tuesday behind the strong
cold front with high temperatures mainly in the 60`s to mid 70`s,
warmest over western Nebraska. Some lower elevation locations
west of the Laramie Range may remain in the 50`s throughout the
day. Of more concern is the strong winds. A strong low to midlevel
pressure gradient will set up across southeast Wyoming as the main
upper level low slowly moves across northern Wyoming and eastern
Montana. May see High Wind criteria across portions of southeast
Wyoming, but not confident enough to add gusts 60+ mph due to it
being the time of the year where strong synoptic winds are
difficult to observe. Kept gusts between 50 to 55 MPH for now over
most of southeast Wyoming with gusts between 25 to 35 MPH across
western Nebraska through Tuesday evening. Any rain showers and
isolated thunder will be mainly confined to Carbon, Albany, and
Converse counties. Some light snow is possible above 9000 feet
across the Snowy range and Sierra Madre range as the upper level
low and southern extent of the cold pool push across the area
through Tuesday evening.
Expect drier conditions Wednesday through the end of the week with
zonal flow aloft across the area and the absence of any fronts or
llvl boundaries across the area. Expect temperatures to gradually
increase back into the mid 70`s (west) to mid 80`s (east) Friday
afternoon. Extended models are hinting at the next cold front
moving in from the north during the weekend, which will enhance
the threat for thunderstorms by Saturday afternoon.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 612 PM MDT Sun Jun 11 2017
VFR conditions are expected through 06Z across all sites. Isolated
thunderstorms will still be possible at CYS/SNY through the
evening. Low clouds will develop by late tonight (09-12Z) over
areas along the Colorado Border with IFR/MVFR cigs possible at
CYS/SNY. East to southeast winds will continue through the taf
period with the strongest gusts on Monday afternoon. There will be
a good chance of thunderstorms, some strong to severe, across the
area during the afternoon.
&&
.FIRE WEATHER...
Issued at 457 AM MDT Sun Jun 11 2017
A windy pattern shaping up across the districts for the first half
of the week as a strong area of low pressure spins through the
northern Rockies. Wind gusts of 35-50 mph will be a possibility
especially across southeast Wyoming Monday night and Tuesday as a
strong Pacific cold front moves through. Otherwise, expect two days
of possible severe weather, beginning today for areas in Wyoming
along and east of the Laramie Range. Monday afternoon/evening looks
to feature a better chance for severe weather for most areas along
and east of the Laramie Range. Temperatures cool on Tuesday, with a
warming and drying trend anticipated through the rest of the week.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...None.
NE...None.
&&
$$
SHORT TERM...CLH
LONG TERM...TJT
AVIATION...ZF
FIRE WEATHER...CAH
Area Forecast Discussion
National Weather Service Houston/Galveston TX
907 PM CDT Sun Jun 11 2017
.DISCUSSION...
Just some minor tweaks to the forecast this update, mainly to acc-
ount for the ongoing POP trends. So far, it appears that HRRR has
initialized the best this evening...and going forward it is indic-
ating an increase of SHRA coverage just off and at the coast over-
night. This activity is then expected to expand to cover a decent
chunk of the CWA by sunrise. 41
&&
.PREV DISCUSSION... /ISSUED 808 PM CDT Sun Jun 11 2017/
AVIATION...
Still a few showers going northeast of UTS with more to the south
of BPT well out into the Gulf. Upper low over the shifted east
throughout the day but should gradually fill and the moist axis
which was directed into Central LA coastal areas today will start
to retrograde back westward overnight into Extreme SETX-BPT area
by 21z Monday. GOES-R precipitable waters showing the moisture
plume already shifting back westward at 00z (ahead of schedule).
Overnight some patchy MVFR ceilings possible with only short lived
impacts. Toward morning though the convergence increases along the
western edge of the moist axis and showers should begin to develop
in and around the Galveston Bay area. Showers should gradually
expand inland 12-16z transitioning over to SHRA/Isolated TSRA with
little if any capping present by 17z. Coverage should be greater
than today. Will carry VCSH/VCTS with either PROB30 or TEMPO for
SHRA late morning through mid afternoon in around the Metro hubs.
45
PREV DISCUSSION... /ISSUED 249 PM CDT Sun Jun 11 2017/
Scattered showers will end early this evening with the loss of
daytime heating. Sfc dew pts have increased and overnight low
temps will only cool into the lower/mid 70`s. An upper level low
will remain over the region through Monday and the combination of
increased low level moisture and the upper level feature will
provide the area with scattered showers and isolated thunderstorms
on Monday. Fcst soundings still show weak capping in the 85-70H
layer but PW values are progged to increase to between 1.6 (GFS)
or 2.1 (NAM). Convective temps will also lower into the middle 80s
so would expect an increase in precip coverage on Monday.
The upper low begins to lose it`s identity on Tuesday as upper
level ridging over northern Mexico tries to expand into Texas.
Moisture levels remain high on Tuesday with PW values near 1.90
inches. Convective temps remain in the mid 80s and little to no
capping is observed in forecast soundings. Will maintain high end
chance PoPs on Tuesday. Upper level heights build on Wednesday as
the upper level ridge expands over SE TX. Convective temps warm
into the upper 80s and capping redevelops in the 85-70H layer.
Rain chances should begin to decrease with coverage becoming more
spotty.
PW values decrease significantly Wednesday night through Friday.
Capping near 850 mb will remain a hindrance for rain chances and
convective temps in the lower/middle 90s won`t provide much hope
for rain. Warmer 8560 mb temps will also translate into slightly
warmer sfc temps and would expect max temps warming into the lower
and possibly middle 90s.
Rain chances look to return for next weekend as the ridge retreats
west a bit and an upper trough over the eastern US retrograde west
and an inverted upper trough over the southern Gulf pushes west.
These features should help to lower heights and and reduce
capping. Low level moisture looks sufficient for diurnally driven
shra/tsra both Saturday and Sunday. 43
&&
.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL) 73 91 74 92 75 / 10 30 10 30 10
Houston (IAH) 75 90 77 90 76 / 20 50 10 40 10
Galveston (GLS) 81 87 82 89 81 / 20 50 30 40 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
Area Forecast Discussion
National Weather Service Jacksonville FL
927 PM EDT Sun Jun 11 2017
...Locally Heavy Rainfall in Daily Thunderstorm Activity remains
the main threat this week...
.UPDATE...East coast sea breeze has pushed westward past the
western edges of the interior SE Georgia and Northeast Florida.
Some locally heavy rain fell across northeast Florida where some
pockets of 2-4" rain amount occurred.In the wake of the sea-
breeze, stratiform rain continues across most areas of North
Floria west of I-95. This stratiform light rain as also persists
across interior SE Georgia. Another batch of light rain is pushing
up from north central Florida. The areal coverage of
precipitation should wane during the late evening hours. Both the
HRRR amd NAM show coverage of shower activity increasing toward
daybreak over coastal Georgia waters advecting in particular
toward the mouth of the Altamaha River Basin with offshore
Atlantic activity increasing during the post midnight hours. South
of the Georgia waters across the NE Florida waters...short range
models show little additional convection overnight except some
isolated activity across the offshore Atlantic waters late.
For Monday...Model guidance supports repeat performance with greater
coverage of afternoon showers/t-storms west of I-95 corridor in
onshore flow pattern. Once again...greatest threat will be very
heavy downpours and strong wind gusts. Consensus guidance supports
high temps in mid to upr 80s.
&&
.AVIATION...Scattered to Broken deck of IFR low clouds expected at
times through 02z where there is stratiform rain occuring on axis
from Gainesville to Cecil Field. Otherwise, VFR conditions
expected for most terminals during the remaining nocturnal hours
with mid to high clouds persisting overnight. Saint Simons being
the exception during the late night-time hours leading up to
daybreak, where Atlantic showers and low clouds may advect into
coastal Georgia with some intermittent IFR conditions possible
between 10-14z. Deep moisture and light easterly low level flow
will tend to focus scattered convection toward the interior by mid
to late afternoon on Monday. There will be a short window in the
late morning to mid afternoon for coastal terminals to see
isolated to perhaps scattered SHRA/TSRA before they transition
inland. Some heavy downpours may bring IFR conditions to Cecil and
Gainseville in the afternoon as showers push inland.
&&
.MARINE...High pressure ridge remains just north of the region
with a weak pressure gradient over the waters. This will support
generally light winds and low seas through the upcoming week.
Rip Currents: Moderate risk in the onshore flow.
&&
.PRELIMINARY POINT TEMPS/POPS...
AMG 72 87 71 89 / 20 60 10 50
SSI 76 83 75 84 / 20 30 20 30
JAX 73 86 71 87 / 20 40 20 40
SGJ 74 83 72 84 / 20 30 20 40
GNV 72 87 71 87 / 90 60 20 60
OCF 72 87 71 87 / 90 60 20 60
&&
.JAX WATCHES/WARNINGS/ADVISORIES...
FL...None.
GA...None.
AM...None.
&&
$$
Cordero/Enyedi/Nelson
Area Forecast Discussion
National Weather Service Lake Charles LA
832 PM CDT Sun Jun 11 2017
.UPDATE...
Updated POP/Wx grids and zones to bump up shower/tstm chcs acrs
the southern zones this evening. KLCH radar shows another cluster
of convection spreading northward acrs coastal southwest LA and
recent HRRR guidance suggests activity will continue to move
northward acrs the I-10 corridor the next few hours. Loss of
daytime heating should offset convective coverage through the
evening, with shower/tstm chcs decreasing some by midnight.
Further south over the coastal waters, expect increasing
convection overnight, with this activity shifting inland Monday
morning.
24
&&
.PREV DISCUSSION... /issued 635 PM CDT Sun Jun 11 2017/
DISCUSSION...
00Z taf issuance.
AVIATION...
Scattered to numerous showers with a few thunderstorms continue
across Central and Southern Louisiana into the coastal waters,
with less coverage over Southeast Texas, but will likely increase
with the convection coming off the Gulf. Latest HRRR guidance
shows this continuing for most of the evening roughly through 10
pm or so and diminishing briefly during the early morning hours.
However, showers expected to reform before sunrise over the Gulf
and possibly affect BPT/LCH/LFT/ARA by 10z Mon, placing VCSH, with
AEX by 15z. Thunder likely to add to the mix by 14z Mon for
BPT/LCH/LFT/ARA, thus changing it to VCTS, and by 18z for AEX.
Greatest chances for TSRA comes in the afternoon between 18-24z,
placing Prob30 groups for TSRA.
DML
PREV DISCUSSION... /issued 402 PM CDT Sun Jun 11 2017/
DISCUSSION...
Latest UA analysis/WV satellite imagery revealed an upper low
spinning over SE TX, with a sfc to mid level ridge over the
Carolinas/WRN Atlantic.
This latter feature has resulted in a long fetch of tropical
moisture pushing into the forecast area. Along with the upper low
and coupled with diurnal instability, this setup has yielded
scattered to numerous showers and thunderstorms across the area
today. Much of this activity will tend to wane with the loss of
that daytime instability, but will hang onto at least small PoPs
for the evening hours. Later tonight, expect nocturnal activity to
begin over the coastal waters and by early MON start pushing into
the coastal counties/parishes. Another active day of convection
appears on tap with the upper low(trof) progged to have moved only
a little east while gradually weakening. High temperatures should
be similar to today, generally topping out in the 85-90F range.
Rain chances will start to decrease on TUE as what remains of the
upper trof continues to fill leaving just a weakness in the height
field. Moisture will continue to be abundant, however, so still
expect scattered showers and thunderstorms to occur, again
primarily diurnally driven. Chances decrease further on WED as
low/mid level ridging builds in from the east while ridging aloft
builds in from the west. Moisture levels, which will start to
decline TUE, will continue to decrease.
THU through SUN, low to mid level ridge is progged to flatten out
and shift to the south while the upper ridge over MX shifts a
little to the west. This will allow rain chances to begin creeping
upward again late week, with a shortwave trof forecast to round
the western ridge enhancing them for the weekend.
13
MARINE...
Light to moderate southeast winds, periodically reaching exercise
caution criteria the next couple of nights, will continue as
surface high pressure remains over the southeast states and
adjacent Gulf waters. Deep tropical moisture will bring an
increase in shower and thunderstorm activity through Tuesday, with
rain chances decreasing mid to late week as mid to upper level
ridging builds aloft along with relatively drier air.
13
&&
.PRELIMINARY POINT TEMPS/POPS...
AEX 73 86 72 89 / 30 70 20 50
LCH 76 86 77 88 / 40 70 20 40
LFT 75 85 74 87 / 40 70 20 40
BPT 77 87 78 88 / 40 70 30 40
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...None.
TX...None.
GM...Small Craft Exercise Caution until 6 AM CDT Monday for GMZ452-
455-470-472-475.
&&
$$
Area Forecast Discussion
National Weather Service Medford OR
857 PM PDT Sun Jun 11 2017
.SHORT TERM...An upper low is centered just southeast of the area
and will gradually move northeastward into northern Nevada on
Monday. This low has brought numerous showers to the area today
and this evening. 24 hour precipitation totals were highest across
southeast portions of the area with around 0.3 to 0.75 inches
recorded across much of Modoc Lake, southeast Klamath and eastern
Siskiyou counties. The highest 24 hour rainfall was 1.30 inches
in Bolam in Siskiyou County and 0.91 inches in Lorella in Klamath
County.
Tonight into Monday, this upper low will continue to affect the
area bringing showers and strong gusty winds, especially to
eastern portions of the area. As a mid level jet circulates into
the area, strong gusty winds are expected to develop into eastern
portions of Lake and Modoc counties tonight and Monday morning.
Winds are expected to gust into the 45 to 50 mph range for these
areas. Please see the NPWMFR for details. Showers will also
continue over areas east of the Cascades, with the bulk of the
shower activity in Lake and Modoc counties tonight into Monday.
Isolated to scattered light showers are expected for areas from
the Cascades west tonight and Monday.
As the upper low continues to move east-northeast out of the
region Monday night, expect winds and showers to diminish.
However, a lingering cold air mass combined with light winds and
clearing skies across areas east of the Cascades will allow
temperatures to lower into the upper 20s to lower 30s. A freeze
watch is currently in effect for portions of the east side. Please
see the NPWMFR for details.
A warming trend follows Tuesday through late in the week.
Additionally, a weak disturbance moves inland Tuesday followed by
a weak front on Thursday. The main effect of the disturbance on
Tuesday will be increased clouds along with a slight risk for
rain in the Southern Oregon Cascades and portions of the Umpqua
and coast. The weak front on Thursday will bring a broader chance
for light rain along the coast, Umpqua and into the Southern
Oregon Cascades.
&&
.AVIATION...12/00Z TAF CYCLE...Moisture wrapping around an area of
low pressure will continue mainly light isolated to scattered
showers and snow showers across the area through Monday. There is
also a slight chance of thunderstorms this evening from around
Klamath Falls eastward. The showers will move in a fast northeast to
north flow aloft with a freezing level around 6000 to 6500 FT MSL,
and begin to diminish by Monday afternoon. This will result in
deteriorating conditions overnight into Monday morning with
increasing coverage of both MVFR cigs and mountain obscuration.
Coverage of VFR conditions will increase Monday afternoon though
with areas of MVFR likely to linger...especially near north to
northwest facing slopes including much of Coos and Douglas Counties.
-DW
&&
.MARINE...Updated 235 PM Sunday 11 June 2017...Winds and seas
will be highest south of Gold Beach, and at a peak this evening as
offshore high pressure builds into the waters. But, seas will remain
steep through Monday evening as wind waves combine with short period
northwest swell. There is now much better model agreement on a
slight strengthening of northwest winds on Tuesday with the
potential for winds to reach small craft advisory strength south of
Gold Beach in the afternoon through evening. Offshore high pressure
will weaken Wednesday as a front approaches the coast. Winds and
seas will be at a minimum on Wednesday evening then winds will
rapidly increase late night into Thursday. The front will move
through the waters Thursday into Thursday evening but will be
focused north of the waters. Light rain and small craft advisory
strength southerly winds are possible with the strongest winds north
of Cape Blanco. West swell dominated seas are likely Friday then
High pressure offshore and a thermal trough near the coast are
likely to produce another episode of moderate to strong northerly
winds during the weekend with the strongest winds south of Port
Orford. -DW
&&
.PREV DISCUSSION... /Issued 505 PM PDT Sun Jun 11 2017/
DISCUSSION...The latest IR and visible image shows what appears to
be a deformation zone of steadier precipitation from central
Siskiyou county north to northeast into northeast Klamath County.
The IR image trend over the last few hours are showing cooling cloud
tops. The high res HRRR shows this for the first couple of hours,
then basically goes away. Neither the NAM or GFS shows this feature
into this evening. I expect this deformation zone to continue into
early this evening with a slight shift to the west towards the
eastern part of the Rogue Valley. The forecast for the rest of the
afternoon and evening will reflect this thinking. This has allowed
some clearing to develop in Modoc, southeast Klamath and most of
Lake county allowing for daytime heating and increasing instability.
We have already seen a few lightning strikes in Modoc and suspect
we`ll see more into early this evening.
Meanwhile the closed upper low will continue to move south towards
Reno Nevada. Reno is about the furthest south the upper low will go
before moving east, then northeast tonight through Monday. The upper
low will be positioned just southeast of our area with the
deformation axis becoming north to south orientated with steady rain
and high elevation wet snow in Modoc and Lake county tonight through
Monday morning. Steady rain will gradually shift into eastern parts
of these counties Monday afternoon. The models are in pretty good
agreement showing rainfall totals 0.50-0.75 of an inch inch of rain
in these areas with local amounts up to an inch possible in far
eastern Lake County tonight through Monday morning.
Pressure gradients are still expected to tighten late this afternoon
through Monday morning. At the same time 700mb winds flow of 45 kts
are expected. This will result in gusty winds over portions of the
east side, especially in Lake and Modoc Counties. At this time were
not expecting gust to reach 45 mph due in part that we`ll be losing
daytime heating and the stronger winds aloft will probably not get a
chance to mix down to the surface. Therefore we`ll hold off on
issuing a wind advisory.
Showers along and west of the Cascades will decrease Monday morning,
then become isolated and mainly confined to the Cascades Monday
afternoon. Temperatures will be milder on Monday, but still below
normal.
Monday night into Tuesday morning, it should dry out across all of
the CWA, except for isolated showers near the Cascades and
Douglas/northern Coos Counties. Clearing skies and lessening winds
should bring the potential for frost/freezing conditions again over
the East Side. Thus, we`ll issue a freeze warning portions of the
east side. Details can be found at NPWMFR.
Tuesday will be dry and milder. A weak shortwave will move north of
the area Tuesday afternoon, but it won`t have any impact on our
weather. The models show a disturbance withing the westerly flow (a
warm front) approaching the area Thursday evening and night. The
models continue to show most of the QPF north of our area, but does
show some in our area. I still suspect the models may be tool
bullish with the southward extend of the precipitation due to the
fact the front will be nearly parallel to the upper flow and 500mb
heights are forecast to increase during the day. For now, kept a
slight chance of rain north of the Umpqua Divide with better chance
for rain in northwest Douglas and northern Coos County.
If nothing else, we`ll have plenty of cloud cover which will only
delay the warm up Thursday and possibly Friday. Model guidance
Thursday and Friday appear too warm given the above scenario and
have undercut the guidance, especially further north by a few
degrees on average both Thursday and Friday.
Dry and much warmer weather is on the horizon for Fathers Day
weekend with temperatures getting back into the 90s in the Rogue
Valley and highs in the mid to upper 80s on the eastside.
-Petrucelli
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...Freeze Watch from late Monday night through Tuesday morning for
ORZ029>031.
Wind Advisory from 2 AM to 1 PM PDT Monday for ORZ031.
CA...Freeze Watch from late Monday night through Tuesday morning for
CAZ084-085.
Wind Advisory from 2 AM to 1 PM PDT Monday for CAZ085.
Pacific Coastal Waters...Small Craft Advisory for hazardous seas until 11 PM PDT Monday
for PZZ350-356-370-376.
Small Craft Advisory until 11 PM PDT this evening for
PZZ356-376.
$$
CC/DW
Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
555 PM CDT Sun Jun 11 2017
.updated for 00z taf discussion below...
.SHORT TERM...(This evening through Monday)
Issued at 210 PM CDT Sun Jun 11 2017
The short term concern remains convective/severe weather potential
into tonight and again into Monday.
Latest SPC mesoanalysis showing MLCAPE increasing to the south
with values to 2500 J/kg into south central MN. The cap is still
rather strong over the area, especially over the northern cwa.
Some breaks/clearing pushing northeast into the southeast metro.
We should see that end and gradually fill back in this evening.
With mid level lapse rates are 7 to 8 C/km and and deep layer shear
40 to 50kts we should see some potentially severe storms with hail
and strong winds if/when convection develops into south central MN
closer to old outflow and developing warm front. It will be
critical in the 00z-03z time frame if the mid level cap can be
eroded. Elevated convection to the north will work east early and
should fill in over west central Wisconsin this evening similar to
the . latest HRRR and other HIRES model solutions. We will
continue the likely pops to the east into the evening and then
trend all pops off to the east and south after 06z.
With the front along the MN/IA border into Monday we will continue
the lower end chance PoP forecast until a stronger forcing
mechanism returns perhaps late Monday afternoon.
.LONG TERM...(Monday night through Sunday)
Issued at 210 PM CDT Sun Jun 11 2017
Tuesday through Wednesday...The stalled front which was
responsible for the severe weather of today will still be draped
over central MN into northern WI as a warm front at the start of
Tuesday. In addition, a large upper level low will be located over
MT/WY with solid SW flow across the WFO MPX coverage area.
Several trough axes rounding the southern periphery of the deep
low will help kick a low pressure center from northern CO into the
western Dakotas, which will help push the surface warm front
north. Moisture will be streaming into the area from the Deep
South with the SW flow, thus chances for precipitation will
continue for the area Tuesday and into Wednesday, during which the
associated cold front of this system will push through. Due to
continued high instability within the warm sector, strong jetting
at multiple levels and the approaching cold front, several periods
are available which could contain at least isolated strong to
severe thunderstorms (hence the Marginal to Slight Risks posted in
days 3 through 4). Highs will generally run from the mid 80s to
lower 90s Tuesday then in the 80s on Wednesday with lows in the
mid 60s to lower 70s Tuesday night. Factoring in dewpoints in the
60s and the deep moisture flow which will again push PWATs to
around 2 inches, the instability and deep moisture will be in
place along with strong deep shear and increasing low level
jetting to make all 3 modes of severe weather possible (hail,
damaging straight-line winds and tornadoes). In addition, pockets
or periods of heavy rain will be possible which could produce
isolated flooding.
Thursday through Sunday...The cold front of this system will have
pushed through the region by daybreak Thursday morning while the
upper level low will move into central Manitoba province on its
way northeast. Surface high pressure will move into the region
behind the front and generally prevail for the end of the week
through next weekend. Though there will be some minor upper level
waves moving through which may produce isolated showers or
thunderstorms during the latter half of the week, no organized
surface systems are evident which will mitigate precipitation
coverage and intensity. Best chances look to come late Friday into
Saturday morning when a nearby low pressure center from the
departed cold front, stalled over the central Plains, drifts north
to northern IA, but nothing significant. Temperatures will go on a
gradual cooling trend late week through the weekend, with highs
dropping to around 80 degrees and lows around 60 by next weekend.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 555 PM CDT Sun Jun 11 2017
Radar showing a couple of areas of convection this evening. This
will mainly affect far easter taf sites through about 05z. Then
indications are stratus/fog will develop over nw WI around 06z an
drops southeast overnight. Brought some of this IFS cig/fog to
eastern taf sites for now. Confidence has increased in stratus
development, but still low confidence on how widespread it will
become. The 15z SREF probs did increase over the last 2 runs or
so. This should lift and burn off 14z-17z with a few cumulus
during the day. Should remain dry at taf sites through 00z Tue.
KMSP...
Looks like convection around a couple hours this evening...before
main show develops to the east/southeast. Expect some IFR cigs to
develop overnight as rains and clearing sky expected to draw in
some stratus/fog in from the northeast. Will trend to vfr after
14z and then mention prob30 late in taf period for psbl tsra as
front lifts north again.
/OUTLOOK FOR KMSP/
Tue...VFR/MVFR with TSRA likely late. Wind S at 10-15kt.
Wed...VFR/MVFR with TSRA possible. Wind S-SW 5-10kt.
Thu...VFR. Wind W 5 to 10kt.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
&&
$$
SHORT TERM...DWE
LONG TERM...JPC
AVIATION...DWE
Area Forecast Discussion
National Weather Service San Francisco Bay Area
855 PM PDT Sun Jun 11 2017
.SYNOPSIS...Shower and thunderstorm chances will end by late
evening as an unseasonably cool upper trough currently over
northern California begins to move to the east. As the system
exits to our east on Monday, a warming and drying trend is
forecast to begin and then continue through the remainder of the
workweek and into next weekend. Near normal temperatures are
forecast to return Wednesday. Above average temperatures will
then develop by Thursday and continue through next weekend.
&&
.DISCUSSION...As of 8:55 PM PDT Sunday...Very active weather
developed across portions of our forecast area late this
afternoon as an unseasonably cold upper low tracked across
northern California. Lines of thunderstorms rumbled across the
North Bay, producing gusty winds and small hail and locally up to
a half inch of rain in Napa County. By early evening a line of
thunderstorms also developed over Contra Costa County. In
addition, isolated showers developed elsewhere in our forecast
area, but by far the most activity was across the North and East
Bay.
In addition to convective precipitation, brisk west to northwest
winds developed today. Wind gusts in excess of 40 mph occurred in
the hills this afternoon and also near the coast. San Francisco
Airport had a peak wind gust of 48 mph.
Shower and thunderstorm activity rapidly dissipated this evening
as surface heating abated. Current radar shows that nearly all
shower activity has ended. Latest NAM and HRRR model output
indicate that isolated showers are still possible through late
evening, but thunderstorm chances have ended and little additional
rainfall accumulation is expected overnight.
The airmass over our area is very cool for this time of year. The
high temperature in Livermore today was only 65 degrees which is
nearly 20 degrees cooler than average for mid June. In addition,
Half Moon Bay and Livermore had identical high temperatures today,
something that is exceedingly rare during the month of June.
Expect chilly conditions overnight with early morning lows on
Monday dropping into the 40s in many locations and perhaps into
the upper 30s in some of the colder inland valleys if skies clear.
One factor that may keep temperatures from dropping too much
overnight is brisk onshore winds, which will diminish slowly
overnight.
The cold upper low will move east and over Nevada by tomorrow,
allowing the airmass over our region to begin to warm. Look for
high temperatures to be about 5 degrees warmer tomorrow under
mostly sunny skies. Even so, temps will remain well below normal
across inland areas. Brisk westerly winds will develop in some
locations once again tomorrow afternoon. However, winds tomorrow
are not expected to be as strong as today.
The warming trend that will begin tomorrow is forecast to continue
on through the remainder of the week and into next weekend as
as heights/thicknesses gradually increase over the Golden State.
By late in the week and into next weekend the models agree that a
broad and flat upper ridge will be in place over California.
Temperatures are forecast to climb to near normal by midweek and
then above normal by the end of the week. The ECMWF builds the
ridge a bit more strongly over California during the extended
forecast period compared to the GFS and therefore the ECMWF
forecasts more robust warming late in the week and into next
weekend.
&&
.AVIATION...As of 10:30 AM PDT Sunday...An approaching upper level
low will bring increased instability and clouds to the area this
afternoon and overnight. The best chance for showers remains
across the north and eastern terminals. Have removed some of the
thunderstorms from SFO south. Not enough moisture. Biggest issue
today will be winds. Strong Northwest winds are expected through
the evening, tapering off only somewhat overnight.
Vicinity of KSFO...VFR/MVFR. Gusty westerly winds today and
probably most of tonight. Thermal trough reaches the SF Peninsula
later this morning into the afternoon with vicinity showers.
SFO Bridge Approach...Similar to KSFO.
Monterey Bay Terminals...VFR. Gusty westerly winds likely developing
by later this morning. Tempo MVFR cigs in a few showers later this
afternoon and overnight. MVFR cigs expected this evening and
overnight with a few lingering showers possible.
&&
.MARINE...as of 08:30 AM PDT Sunday...A cold upper level low will
track into northern California today bringing increasing
northwest winds and a slight chance of showers and thunderstorms
to the coastal waters, mainly north. High pressure and dry weather
then return early to mid next week with northwest winds remaining
moderate to strong.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.Tngt...SCA...Mry Bay
SCA...Pt Arena to Pt Reyes 0-10 nm
SCA...Pt Reyes to Pigeon Pt 0-10 nm
SCA...Pigeon Pt to Pt Pinos 0-10 nm
SCA...Pt Pinos to Pt Piedras Blancas 0-10 nm
SCA...Pt Arena to Pigeon Pt 10-60 nm
SCA...Pigeon Pt to Pt Piedras Blancas 10-60 nm
SCA...SF Bay
&&
$$
PUBLIC FORECAST: Dykema
AVIATION: Sims
MARINE: Sims
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Area Forecast Discussion
National Weather Service Omaha/Valley NE
1002 PM CDT Sun Jun 11 2017
.UPDATE...
Issued at 958 PM CDT Sun Jun 11 2017
Have made some significant changes to the going forecast...mainly
after midnight. Good reason to believe at this point cluster of
storms will increase in areal coverage on nose of steep sfc-3km
lapse rates...in conjunction with strengthening llvl jet. Thus
have increased pops mainly over the nrn and ern CWA to tonight.
&&
.SHORT TERM...(Tonight through Wednesday)
Issued at 330 PM CDT Sun Jun 11 2017
Forecast concerns in the short term will be the heat (near record
highs Monday??) and will the forcing be strong enough tonight to
break the cap and utilize the pooled moisture/instability...
thunderstorm chances/severe weather potential through Wednesday.
The 12Z upper air maps from this morning had closed h5 low pressure
centered over northern California with southwest flow across the
Rockies into the Northern Plains. Number embedded shortwave were
over eastern CO, eastern SD/MN. The hot dome of air was solidly
over Nebraska nosing into southeast SD and h7 moisture with 6-8 deg
C air was pooled from the Dakotas into MN. Closed h85 low pressure
was centered over west central Nebraska with a 60kt low level jet
from Kansas into central Nebraska. The 18 degree C h85 dewpoints
covered a large area from KS/NE into IA/srn MN/Central KS.
Clusters of storms formed over the western high plains and expanded
across South Dakota by midnight with a shortwave...then a bowing
mesoscale convective complex developing along the instability
gradient with 35 to 50kt h7 winds/waa and 0-3km shear vectors of 40-
50kts. The complex pushed eastward into Minnesota with widespread
damaging winds and hail reports.
At 20Z...the surface front was south of ONL and west of YKN.
Clouds held temperatures to the upper 80s north, however readings
were ahead of yesterday in the mid 90s with heat index values
around 100 and south winds 15 to 30 mph with gusts 30 to 35 mph.
The latest WSR-88D radar mosaic showed the most active storms over
northern Wisconsin...with a line of showers and thunderstorms
north of the warm front from eastern South Dakota into western
Minnesota. Water vapor satellite imagery highlighted the shortwave
over Colorado with quite a bit of cloudiness across the state.
SPC mesoanalysis graphics had MLCAPE of 3000-3500J/kg across the
local region with a weakness in the inhibition toward McCook and
in eastern South Dakota. The RAP fcst/trends is to continue to
weaken the cap while increasing CAPE to 4000J/kg. The H7
temperatures are around 16 deg C. so this limits confidence that
the RAP may be too quick in eliminating the inhibition. The latest
RAP13/HRRR/ESRL HRRR/HopWRF hint that isolated storms will
develop somewhere in central Nebraska and could stretch into
northeast Nebraska 01-03Z...with further development near the SD
border. The NAM12 generally holds off until the shortwave arrives
after 06Z. The GFS is similar to the NAM12 and the EC is a bit
more aggressive with an isolated storm in east central
Nebraska...then farther north toward the SD border with the
shortwave. The CMC and UKMet are similar with very limited
coverage.
The mid tropospheric pattern through Wednesday is for the h5 low
to track from northern CA to Nevada/Idaho Monday...slowly moving
across Montana Tuesday and finally lifting into southern Canada.
A shortwave trough embedded in the southwest flow aloft and
increasing upper level divergence tonight...but even moreso
Tuesday night will provide multiple rounds of storms with the cold
front hanging out in the central Nebraska...then lifting north
Tuesday and the push of the cold front through Tuesday night and
Wednesday morning.
Will include isolated to scattered thunderstorm mention in
northeast Nebraska tonight and metwatch areas farther south. Due
to the instability and deep layer shear, storms may become severe
with large hail and damaging winds. Tonight and Monday the
marginal risk for severe storms includes parts of northeast/east
central Nebraska with the slight/enhanced risk for WY/western
Neb/SD. There is a 30-40kt 0-3km wind max Monday morning with may
boost storm near the NE/SD or northward.
Showers and thunderstorms should be ongoing north of the front.Quite
a few clouds with the abundant moisture should re-develop
overnight across parts of the rest of the area...however look for
these to give way again across the southern part of the forecast
area. Breezy south winds will again help boost temperatures.
Highs are forecast with lower to mid 90s. With more clouds
north...readings may be held to 85 to 90. The records are a bit
out of reach between 99 and 101 at OFK/OMA/LNK.
Stronger forcing arrives Tuesday afternoon and Tuesday night and
should see a better chance for thunderstorms...enough to include
some likely pops. Very high CAPE (4-5 KJ/kg)/deep moisture 1.5-2
pwat/40-50kt 0-3km shear...point toward a good risk for severe
storms with damaging winds/large hail and locally heavy rain.
Highs Tuesday should again top out in the 90s.
The storms push out of the area Wednesday morning. Highs Wednesday
should mostly range from 85 to 90 with much drier air moving in.
.LONG TERM...(Wednesday night through Sunday)
Issued at 330 PM CDT Sun Jun 11 2017
The flow is more westerly with ripples in the flow that may touch
off thunderstorms. Highs Thu-Sun should range from the mid 80s to
lower 90s.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 615 PM CDT Sun Jun 11 2017
Broken mid level clouds between FL050 and FL080 will be common
much of the TAF period across eastern Nebraska. A weak cold front
will dip south of KOFK for a brief time this evening, the travel
back north, keeping generally south flow at TAF sites. Scattered
thunderstorms developing northwest Kansas and south central
Nebraska will track northeast toward northeast Nebraska, and could
affect KOFK between 04Z and 14Z, however expect storms to move
north of that site.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...None.
IA...None.
&&
$$
UPDATE...DEE
SHORT TERM...Zapotocny
LONG TERM...Zapotocny
AVIATION...Dergan
Area Forecast Discussion
National Weather Service Pueblo CO
518 PM MDT Sun Jun 11 2017
.UPDATE...
Issued at 517 PM MDT Sun Jun 11 2017
Updated forecast/zones to account for isolated shower and
thunderstorm activity over far northern sections of the forecast
district into this evening, including but not limited to portions
of Teller and El Paso counties.
&&
.SHORT TERM...(This evening through Monday)
Issued at 253 PM MDT Sun Jun 11 2017
A frontal boundary moved through some of the southeast plains,
hampering additional warming and increasing dew points.
Tonight an upper level low will move from along the central CA
coast, northeastward into northern NV, and then on Mon it should
move over southern ID. This will keep southwest flow aloft over
southern CO.
This evening the NAM and HRRR show some pcpn just north of the
Palmer Divide, with southern CO remaining dry. However, some
showers/tstms could get close to northern El Paso and northern
Teller counties this evening. The high level clouds that have been
covering much of the area today, are expected to move out of the
area early this evening. Then later tonight, the NAM and HRRR show
the potential for low stratus over portions of the southeast plains,
mostly after midnight. The mountain areas and high valleys should
see little in the way of cloud cover tonight.
Mon will be another dry and warmer than average day across southeast
and south central CO. Gusty south to southwest winds are expected
to develop in most areas for the afternoon hours. Relative
humidities should be quite low in the afternoon, less than 15
percent. Weather-wise, conditions will meet critical levels, but
with the fuels being green, no fire weather highlights will be
issued for Mon.
.LONG TERM...(Monday night through Sunday)
Issued at 253 PM MDT Sun Jun 11 2017
Minimal adjustments required from previous longer term meteorological
reasoning with main issues continuing to be generally above
seasonal mid-June temperatures, gusty winds at times and
increasing precipitation potential by later next weekend.
Latest longer term computer simulations, PV analysis and forecast
model soundings suggest that basically dry, warm and gusty winds
at times should continue to be noted over the forecast district
during the balance of the longer term as dry southwesterly to
zonal upper flow from Monday evening into Thursday transitions to
an upper ridging pattern becoming established over New Mexico by
next weekend.
It still appears that varying degrees of eastern Colorado lee-side
surface troughing should be noted from Monday evening into
Wednesday in advance of a northerly surge moving across eastern
sections Wednesday night.
In addition, meteorological parameters still appear to be coming
together to permit increasing precipitation chances over the
forecast district from later Saturday into at least next Sunday
evening.
Generally above seasonal mid-June minimum and maximum temperatures
are anticipated during the longer term with warmest temperatures
projected from Friday into Saturday.
Finally, the highest potential for gusty gradient winds during the
longer term are expected from Monday evening into Tuesday evening.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 253 PM MDT Sun Jun 11 2017
VFR conditions are expected during most of the next 24 hrs.
However, forecast models are showing the possibility of some low
stratus late tonight/early Mon morning for a few hours at, or in the
vicinity of KCOS and KPUB. If the low stratus moves into the area it
could lead to MVFR conditions. KCOS, KPUB and KALS should have
gusty south to southwest winds Mon afternoon, with gusts of 20-30
kts.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
Area Forecast Discussion
National Weather Service Blacksburg VA
757 PM EDT Sun Jun 11 2017
.SYNOPSIS...
Strong high pressure will dominate the weather through mid week
bringing summer-like weather.
&&
.NEAR TERM /THROUGH MONDAY/...
As of 755 PM EDT Sunday...
The only real change to the update was to increase cloud cover,
mainly for aviation grid purposes, as extensive high clouds
cover was spreading northeast from the southeast U.S. the 18Z
GFS indicates good potential for BKN-OVC 250 later tonight into
Monday. Otherwise, T/Td readings are generally on track.
Increasing cloud cover will likely lead to one of the warmest
nights of the year so far in many areas. Patchy fog remains a
possibility in a few decouples spots, like LWB and BCB. No other
changes needed at this time.
As of 230 PM EDT Sunday...
High pressure centered just off the southeast Atlantic coast
will slowly move east tonight into Monday. This will continue our
Summertime weather pattern into the first part of next week. Diurnal
afternoon cu will dissipate with the loss of solar heating this
evening. The HiResW-arw-east and hrrr are hinting at an isolated
showers across the higher terrain in the southwest mountains. CAP
this afternoon looked strong enough with subsidence to keep forecast
dry. The combination of light winds and low level moisture may
result in patchy fog/haze late tonight into Monday morning. Low
temperatures tonight will range from the lower 50s in the mountains
to the mid 60s in the Piedmont.
Southerly flow is push moisture up from the south and humidity will
notably increase Monday. Allowed for some isolated showers across
the southwest mountains Monday afternoon as supported by NAM, HiResw-
ARW-East, and GFS. Models are overdone on coverage for Monday with
CAP and weak lift still in place. High temperatures Monday will
range from the mid 70s in the mountains to the lower 90s in the
Piedmont.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
As of 240 PM EDT Sunday...
Stacked ridging across the region will linger into Monday night before
slowly weakening Tuesday as residual upper energy over the southeast
states works north along the Appalachians. Forecast soundings show
enough dry air/capping aloft to limit convection to perhaps an isolated
shower or two NC ridges early Monday evening before moisture quickly
returns Tuesday per forecast PWATS. This along with strong instability
given heating should allow convection to more readily unzip across the
mountains Tuesday afternoon at least in scattered fashion under a very
weak flow regime. Therefore bumped pops to higher chance far west and
included coverage out to the Blue Ridge, and perhaps isolated farther
northeast by early evening pending outflow. This in line with the
latest ECMWF and wetter GFS across the mountains, while basically
keeping the southeast sections dry where still under part of
the ridge/cap aloft. Will stay quite hot/humid with highs 80s
mountains to 89-93 east.
Upper ridge may briefly restrengthen by Wednesday in wake of the
Tuesday convection and ahead of a weak backdoor front sliding south
toward the area by late in the day. This could tend to delay coverage
somewhat into Wednesday afternoon while possibly giving rise to more
organized, at least pulse nature stronger storms over the ridges late,
and across the far north ahead of the boundary under very high
instability. However still uncertainty as to just how far south
and east best coverage will develop, so keeping chance pops
southeast third with likely pops elsewhere for now. Despite
potential for more convection, temps should stay on the hot side
espcly given some weak compression ahead of the backdoor front.
Thus leaned toward the warmer Mos given slight 850 mb warming
and more insolation early on which should push highs into the
90s in the east Wednesday afternoon.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
As of 130 PM EDT Sunday...
Ridging will continue to break down during midweek in response to weak
sheared shortwave energy over the southeast states but more so with the
approach of a bit stronger northern stream trough from Midwest by weeks
end. This feature will be associated with another weak cold front that
should gradually work toward the region but likely still remain west of
the mountains through Day7 given the strong ridging to the south/east.
In addition a weak backdoor type front ahead of the main system will
slip south perhaps reaching northern sections Thursday, and possibly
west to the Blue Ridge by Friday pending the degree of earlier
convection to help force it south. Otherwise moisture will increase
enough for at least scattered convection Tuesday evening and espcly
across the north-west Wednesday, where will carry likely pops given
forecast high instability and forcing ahead of the backdoor boundary.
A very warm/humid environment to exist Thursday into Sunday with pieces
of shortwave energy sliding across ahead of the passing upper trough on
Saturday. This should provide for daily rounds of showers/storms with
best focus perhaps Thursday/Friday and just ahead of surface front to
the northwest Sunday. However given uncertainty with coverage of daily
storms, will run with mainly afternoon/evening likely pops except a bit
less Saturday. Rather hot temps for midweek will taper back to just a
little above seasonal values into next weekend due to the backdoor
front including cooling aloft as well as clouds/showers.
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
As of 745 PM EDT Sunday...
VFR conditions expected to continue through the TAF valid period
with the possible exception of a brief period of MVFR BR at KLWB
and KBCB just before sunrise Monday. The synoptic pattern
features a strong 593dm subtropical ridge overhead. The upper
ridge will continue to shift east toward the coast Monday,
allowing deep Gulf moisture from a weak area of low pressure in
the eastern Gulf to spread northward on the backside of the
high. Expect an increase in CU and some swelling CU Monday
afternoon with the first potential for a few showers across the
western mountains, roughly along and west of the I-77 corridor.
Not enough confidence at this point to include the TAFs, but may
be something to add to the KBLF TAF with later issuances. While
mid clouds may become BKN at times Monday afternoon, not
expecting any ceilings below 045 at this time. Otherwise, an
extensive area of cirrus from the southeast U.S. will translate
north and northeast through the period creating a high-level
BKN-OVC condition at times, especially late in the day Monday.
With the increase in high clouds overnight and the warm
temperatures today, T/Td spreads are pretty good yet. However,
low-level moisture also continues to increase and dewpoints are
creeping up into the high 50s and low 60s across the CWA. We may
begin to see patchy fog just before sunrise at a few spots, the
most likely would be KBCB and KLWB, so have included that with
this TAF set. Confidence in development and how dense is low at
this point.
Winds will generally be SSW-SW through the period at speeds of
5-8kts as high pressure slowly slides to the east of the area.
High confidence in ceilings through the TAF valid period.
High confidence in visibility through the TAF valid period,
except medium confidence in the 08Z-13Z time frame Monday
morning.
Medium to high confidence in wind speed and direction through
the TAF valid period.
Extended Aviation Discussion...
Deep Gulf moisture will spread north and northeast from the
Midsouth and Southeast U.S. into the Mid-Atlantic region through
midweek. Expect an increase in diurnally driven showers and
thunderstorms beginning Tuesday, mainly west of the Blue Ridge
at first. By Wednesday, a backdoor cold front will be
approaching from northern VA and will interact with the deep
moisture to result in scattered to numerous showers and
thunderstorms. This front will linger in the area through
Thursday before retreating back to the north. A stronger cold
front and upper-level disturbance will arrive from the west late
in the week. Therefore, expect scattered to numerous convective
activity, mainly during the afternoon and evenings, throughout
the week beginning Wednesday. Wed-Fri offer the best
opportunities for widespread showers and thunderstorms and
extended periods of sub-VFR ceilings and visibilities. In
addition, radiational late night/early morning fog will be on
the increase once daily showers and thunderstorms commence,
hence Wednesday morning onward.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...None.
NC...None.
WV...None.
&&
$$
SYNOPSIS...KK/PM
NEAR TERM...KK
SHORT TERM...JH
LONG TERM...JH
AVIATION...KK/PM/RAB