Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 06/17/18
Area Forecast Discussion
National Weather Service Gaylord MI
1143 PM EDT Sat Jun 16 2018
.UPDATE...
Issued at 954 PM EDT Sat Jun 16 2018
Looking a bit more at the overnight hours, the idea for pops
ramping up somewhat still appears sound. The low level jet veers
to the wsw and strengthens into MI overnight. That will bring the
warmer/juicier airmass found west of Lake MI east. For most of
northern lower MI, there is no obvious trigger, beyond the general
warm/moist advection at low levels. So a small chance is fine
here, and Rap/HRRR qpf fields are in support of this. We have a
somewhat chance in eastern upper and perhaps the Straits, as a
warm front makes slow northward progress into northern WI. Ongoing
precip near/north of that boundary will reinforce that thermal
boundary, maintaining it as a forcing mechanism. That said, much
of the near-term guidance is not terribly excited in producing a
lot of QPF in eastern upper MI (the operational Nam is the primary
exception). So will maintain somewhat higher pops north of M-68
overnight, but not drastically so.
UPDATE Issued at 817 PM EDT Sat Jun 16 2018
Some forecast fine-tuning in order. Presently no precip in
northern MI, and mid-high clouds have been thinning a bit,
especially south of M-68. Temps in central and southern sections
are still near, or even at, their highs for today. However,
another batch of showers is forming in central upper MI, as a
series of MCVs interact with a warm/moist airmass. Have reduced
pops in northern lower for the 1st half of the night, maintaining
a slight chance near Lake MI and the Straits. Have kept and even
increased pops in eastern upper thru 06z/2am, especially western
Chip Co.
&&
.NEAR TERM...(Through Tonight)
Issued at 323 PM EDT Sat Jun 16 2018
...Warm and humid with a slight chance of showers and storms
tonight...
High Impact Weather Potential...A few thunderstorms possible with
heavy rain...
Pattern Synopsis/Forecast...Strong high pressure remains centered
over the Mid Atlantic states...while a complex area of low pressure
continues to develop over the Northern Plains and then Upper
Mississippi Valley. Several areas of convection continue to fire in
the vcnty of the low pressure center and along/north of the
associated warm front which is slowly lifting NE thru Michigan.
Upstream convection has been hard pressed to push eastward into our
CWA so far today thanks to the drier and more stable airmass in
place over our area. Latest near term models continue to support the
demise of the upstream convection over Lake Michigan during the rest
of the afternoon and early evening hours. Latest NAM12 is a bit more
robust with the idea of an area of convection driving eastward thru
Upper Michigan overnight...but the RAP still insists that this
convection will ride north of our CWA. Have opted to keep highest
chance POPs across Eastern Upper Michigan overnight...with mainly
slight chances of a shower or storm across Northern Lower Michigan
through tonight. Wind fields certainly do not support any chance of
severe storms despite better instability developing late this
afternoon/evening.
So far...thicker mid/high clouds from upstream convection have
greatly limited diurnal heating today...and have dropped expected
afternoon highs (and may need to drop them further). Expect a mild
and muggy night across Northern Michigan...with overnight lows
ranging from the low to mid 60s across Eastern Upper Michigan to the
lower 70s in our SW CWA.
&&
.SHORT TERM...(Sunday through Tuesday)
Issued at 323 PM EDT Sat Jun 16 2018
...Warm and humid to end the weekend and to begin the work week...
High Impact Weather Potential: Marginal as heat index nears 100
degrees Sunday with chances for convection and heavy rainfall.
Primary Forecast Concerns/Challenges: The main forecast concerns
through the period will be centered on high dew point air, afternoon
temperatures, and the corresponding heat index and chance for
thunderstorms through Monday.
Patten Synopsis/Forecast...The nearly stationary pattern that set up
over the eastern third of the country earlier in the weekend, will
eventually break down over the Great Lakes to begin to the upcoming
work week. The large area of high pressure over the mid Atlantic
through the weekend, will diminish and push further east into the
Atlantic which will allow the storm system in the Plains to push
across the state Monday, before exiting east of the region Monday
night. This pattern (surface and upper level ridging centered over
the Great Lakes), will keep pcpn chc limited over nrn Michigan
through Sunday afternoon. However, 850/700mb qvectors associated
with the approaching boundary, show some strong forcing influencing
northern Michigan between 06z Monday and 06z Tuesday, as the Plains
boundary slowly drifts south across the forecast area. Model
soundings and short term data show an unstable airmass across the
Great Lakes as the boundary drops south Monday.
Sfc dew pts will be in the upper 60s, 850mb dew pts near 16c, 0-3km
cape nearing 2000 j/kg with 850/700mb lapse rates around 7 c/km.
Model soundings show main threat with convection Monday will be
heavy rainfall (pwat around 2inch), while mid lvl warming and weak
vertical wind profiles hinder strong wind gusts and large hail.
Some concern continues about developing heat index over much of
northern Michigan Sunday with the potential for morning convective
cloud cover reducing afternoon heating (much like today) and
limiting overall heat Sunday. However areas around Saginaw Bay will
be most likely to see heat index value in the low 100`s in a thinner
veil of clouds, afternoon temps around 90 and surface dew points
nearing 70 degrees.
.LONG TERM...(Tuesday night through Saturday)
Issued at 323 PM EDT Sat Jun 16 2018
A fairly inactive, early summer, pattern is expected across the
Great Lakes region through much of the the forecast period as an
area of high pressure and nearly zonal flow aloft anchor in through
the end of the work week. 850mb temps in this pattern will linger
between 12c and 15c, helping continue warm temperatures in the 80s
across northern Michigan. The chance of rain increases for the
upcoming weekend, as a system lifts into the Ohio Valley and srn
Great Lakes.
&&
.AVIATION...(For the 06Z TAFS through 06Z Sunday night)
Issued at 1143 PM EDT Sat Jun 16 2018
Mainly VFR. LLWS at PLN early this morning. LLWS all sites Sunday
evening.
Warm/muggy air continues to make slow inroads into northern MI.
Might have to watch for some patchy ground fog at the TAF sites
overnight, but for now will keep things VFR. Increasing cloud
cover and a tightening pressure gradient will limit fog
potential. Some showers will skirt across eastern upper MI during
the night, perhaps getting into the neighborhood of PLN, but most
likely will stay to the north. Mainly dry, somewhat sunnier, and
warmer on Sunday.
Light s to sw breeze. LLWS at PLN overnight, with stronger sw-
erlies in place just off the surface. LLWS for all sites Sunday
evening.
&&
.MARINE...
Issued at 323 PM EDT Sat Jun 16 2018
Winds and waves will remain below SCA criteria thru Sunday night
despite the approach of a cold front and it`s expected arrival late
Sunday night and Monday. Chances of showers and thunderstorms will
steadily increase as this front moves closer to our CWA during the
remainder of the weekend. Otherwise...expect warm and humid
conditions.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...HEAT ADVISORY from 11 AM to 8 PM EDT Sunday for MIZ031>036-041-
042.
LH...NONE.
LM...NONE.
LS...NONE.
&&
$$
UPDATE...JZ
NEAR TERM...MR
SHORT TERM...SR
LONG TERM...SR
AVIATION...JZ
MARINE...MR
Area Forecast Discussion
National Weather Service Bismarck ND
830 PM CDT Sat Jun 16 2018
.UPDATE...
Issued at 820 PM CDT Sat Jun 16 2018
Have significantly lowered pops north of Interstate 94 and west of
highway 281 for tonight. Have also removed thunder from most of
that area and just went with rain showers.
The southern James River Valley counties will have a risk of
severe weather until around midnight or so with the highest
chances for that in Dickey County.
Have added patchy fog to the forecast, mainly west where 1-2
inches of rain fell today.
&&
.SHORT TERM...(This evening through Sunday)
Issued at 230 PM CDT Sat Jun 16 2018
The chance for severe thunderstorms and heavy rainfall over the
far south central and southern James River Valley highlights the
short term.
A closed off upper low, located over the Pacific Northwest, will
continue to spin and eject shortwaves through the rest of the
afternoon and overnight. Two embedded shortwaves were noted on
water vapor. One wave is located over western North Dakota and is
currently triggering widespread showers and thunderstorms over
western North Dakota, extending along a line from Bowman county
to just south of Harvey. Another wave was noted over western
South Dakota and will be the focus of stronger convection as it
interacts with a stalled out surface front currently draped over
South Dakota. As forcing approaches this boundary late this
afternoon and evening, expect thunderstorms to develop rapidly
over much of central and northern South Dakota. The latest CAMs
have some of this activity slowly drifting north into our south
central and southeastern zones tonight.
Given forecast MUCAPE values in the 500 to 2000 J/kg through 06z
over the far south with 35 to 50 knots of deep layer bulk shear, a
supercell or two cannot be ruled out as the stalled boundary
lifts north. There is still uncertainty in regards to how far
north the boundary will lift, with many different solutions
provided by the CAMs. The last few iterations of the experimental
HRRR have probably been some of the most aggressive runs with
northern propagation of the stronger storms tonight, reaching as
far north as Stutsman county, and trailing southwest into Sioux
county past 06z. While its solution has been somewhat consistent,
it remains an outlier at the moment. The expectation is that this
convective activity will be fairly elevated. Thus, the biggest
concern will be large hail with any of the stronger storms in the
window from 00z to 06z tonight.
Scattered light showers will linger through much of the day on
Sunday, mainly in the south.
.LONG TERM...(Sunday night through Saturday)
Issued at 230 PM CDT Sat Jun 16 2018
Some light shower activity will continue through Monday as
surface high pressure tries to move in, with only low chances
lingering mainly along our southern border. Mainly dry conditions
are expected on Tuesday as the upper low meanders over the
western CONUS with modest ridging setting up over our area ahead
of it.
Precipiation chances then remain low for the remainder of the work
week with a variety of weak disturbances moving through.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 820 PM CDT Sat Jun 16 2018
Severe thunderstorms are possible from KJMS and south into South
Dakota until about 06Z or so. Over the rest of the area a few
showers are forecast. After 06Z showers and storms may become
more widespread along the South Dakota border, especially south of
KBIS to south of KJMS.
In the rain of today, many locations in the west getting around an
inch and some areas an inch and a half of rain, patchy fog could
form. For TAF sites the main concern would be KDIK where IFR
ceilings are also a concern.
MVFR ceilings will be in and out across the south KDIK-KBIS-KJMS,
maybe even an IFR ceiling at KDIK.
For daytime Sunday, dry north with showers and a few storms along
the South Dakota border.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JPM
SHORT TERM...ZH
LONG TERM...ZH
AVIATION...JPM
Area Forecast Discussion
National Weather Service Birmingham AL
726 PM CDT Sat Jun 16 2018
.UPDATE...
For 00Z Aviation.
&&
.SHORT TERM...
Through early evening.
The stubborn mid to upper level low continues to spin across
southern Alabama as of midday. Scattered to numerous showers and
storms continue to be triggered across Pike, Barbour, and Bullock
counties with heavy downpours and occasional cloud to ground
lightning. Convection associated with the low is also located
where the most moisture is present, according to the GOES Total
Precipitable Water product. We`re expecting convection to continue
in those areas for the rest of the afternoon, with some additional
bands of showers & storms possible a bit farther north along the
I-85/U.S. 80 corridor later on this afternoon.
Elsewhere across Central Alabama, dry air aloft continues to play
a role in the forecast. The 12z KBMX sounding indicated much
drier air than yesterday across the profile with PWATS of 1.46
inches. Even drier air is being indicated across northeastern
Alabama and southeastern Tennessee according to GOES PWATS. The
dry air continues to help suppress convective development, but
we should still see at least scattered showers and storms as far
north as the I-20 corridor later this afternoon. We still can`t
rule out a few strong storms with gusty winds due to that dry air
aloft. Some guidance is hinting at a moderate microburst potential
across the northern half of Central Alabama. Conditions aloft are
also a bit cooler than they were yesterday according to this
morning`s sounding, so more unstable as well. RAP analysis is
indicating SBCAPE values of over 4000 J/KG across east and
northeastern Alabama as we rise into the 90s. Just to our east,
orographically triggered storms in northern Georgia have been
quite strong, so that`s something else we`ll have to keep an eye
on for our area as well.
In terms of the overall forecast, have bumped up temperatures
based on yesterday`s highs and current observation trends a few
degrees for most locations. Low to perhaps mid 90s are expected
for most locations in the northern half of Central Alabama, with
mid to upper 80s south. Temps really haven`t risen much at all in
the far southeast counties with widespread showers and storms
continuing.
56/GDG
Previous short-term discussion:Today and tonight.
Radar is a lot quieter this morning as compared to the previous two.
The main upper low that has been influencing the weather over the
past several days is now positioned generally south of Troy and will
begin to slide east-north during the day today and actually slide
northward, generally along and near the I-20 corridor through the
night. Based PoPs on the overall progression of the low. Clouds and
precipitation will play havoc on temperatures again, but look for
much of the same with 90s in the north and low to mid 80s in the
south. Best coverage today will be in the south but we should see a
little bit more in coverage this afternoon as the low moves
northward. Look for activity to diminish some after 10 pm, but may
see an uptick in coverage after Midnight across the north, so
increased PoPs through the early morning hours. This trend will
continue into Sunday.
16
.LONG TERM...
Sunday through Saturday.
The weak upper level meso low that we`ve been talking about the past
few days just won`t go away. It retrogrades back over Central AL and
lifts northward on Sunday, leading to increase rain/thunderstorm
chances across the area. I have increased PoPs for Sunday afternoon
and into Sunday night/Monday morning to account for the persistent
meso low.
A low pressure system in the Pacific NW digs into the Great Basin
Monday, which helps amplify the ridge across the Eastern CONUS. This
will shift the center of a high pressure system more over Central AL
through midweek leading to more limited afternoon convection. With
that said, we do have plenty of moisture in the region, so expect
roughly 30-40% chance of rain each afternoon for the majority of the
upcoming week, decreasing to 15-20% in the overnight hours.
Models hint at the ridge beginning to break down towards the end of
the week. The GFS brings in a few shortwave impulses through the Mid-
Mississippi Valley, which could lead to some extra lift across
Central AL. The ECMWF brings a stronger low pressure system through
the Upper Plains and into the Midwest, stretching a weak cold front
through our area by Friday into Saturday. At this time, I`m leaning
more towards the GFS as the ECMWF seems to be having some issues
resolving a couple of cut-off lows towards the end of the extended.
Therefore, will go with increased PoPs (40-50%) Friday and Saturday
with the increased lift for the afternoons.
Overall, looks to be a fairly typical week for the summer weather-
wise across Central AL with highs in the low 90s and lows in the low
70s with seasonal diurnal shower/thunderstorm activity.
25/Owen
&&
.AVIATION...
00Z TAF Discussion.
The general trend of the previous few days and the last issuance
will be kept going this package. Expect another night where
patchy fog and lower clouds develop. There will be areas where IFR
ceilings develop and areas where IFR vis develops, but both may
not be at all terminals.
An upper low and numerous boundaries were kicking off showers and
thunderstorms at this hour. Plenty of instability still around and
expect the storms to last a few more hours before a general
decrease is seen. As the upper low moves slowly northward into
east Alabama overnight, showers or storms may develop. Confidence
in this development was too low at this time to mention overnight.
Lows clouds and patchy fog expected for several hours around
sunrise. Redevelopment of thunderstorms likely by afternoon and
started with PROB30 again.
75
&&
.FIRE WEATHER...
Scattered to numerous showers and storms expected today and
tomorrow during the afternoons. Rain chances are lower for Monday,
but cannot rule out at least isolated coverage during afternoon.
Light fog and/or low clouds are possible each morning, and most
likely will be near locations that receive rainfall the previous
day/evening. RH values remain well above critical values. There
are no fire weather concerns at this time.
&&
.PRELIMINARY POINT TEMPS/POPS...
Gadsden 70 89 70 90 71 / 40 60 30 40 10
Anniston 70 88 69 90 70 / 40 60 30 40 10
Birmingham 72 89 71 90 72 / 40 60 30 40 10
Tuscaloosa 73 91 72 92 72 / 30 60 30 30 10
Calera 71 88 69 89 71 / 30 60 30 30 10
Auburn 70 87 70 89 71 / 40 50 30 40 10
Montgomery 71 90 71 91 72 / 40 50 30 30 10
Troy 71 89 71 91 72 / 40 40 30 30 10
&&
.BMX WATCHES/WARNINGS/ADVISORIES/...
None.
&&
$$
Area Forecast Discussion...Updated
National Weather Service Billings MT
826 PM MDT Sat Jun 16 2018
.UPDATE...
Some low topped convection developed over our western areas this
evening and is trying to push east. Other than an isolated severe
storm near Joliet/Boyd early in the evening, the convection has
been rather weak and unable to sustain itself much past Billings.
Nothing really developed early this evening over Sheridan county
so we reduced PoP`s in this area. We still have jet stream over
our region and another shot of moisture upstream headed for our
mountains later tonight into Sunday. BT
&&
.SHORT TERM...valid for Sun and Mon...
Precipitation continued to shift NNE this afternoon per radar
imagery. Lightning decreased over the eastern zones due to morning
convection modifying the airmass, and breaks in the cloud cover
were developing over the west. SW flow continues over the region
tonight, then upper ridging builds into the area from the SW on
Sunday. Models continued to show a convective bullseye developing
between 00Z and 03Z somewhere in NE WY. RAP sounding in KSHR
decreases CAPE rapidly this evening, but RAP did have CAPE
further E and S, so kept the mention of showers and thunderstorms
for SE MT and Sheridan County. Elsewhere just had chances for
showers and a slight chance of thunderstorms. Precipitable waters
will remain over an inch, with lesser values in the W, through the
period.
With upper ridging over the area on Sunday, just had chance PoPs
over most of the area. However, had likely PoPs over the far W in
the morning, as some diffluence will move into this area. 700 mb
temperatures will be 0 to +2 degrees C over the Absaroka/Beartooth
Mountains in the morning, so accumulating snow is likely over the
Beartooth Pass. Later shifts can evaluate the need for an Advisory
for the Beartooth Pass. Diffluence moves over the area Sun. night
and continues into Monday. Easterly flow develops from the surface
to 850 mb during this time and precipitation chances increase
again. Had highest PoPs from KBIL W through Monday with upslope
flow bringing extra lift to these areas. Kept just a slight chance
of thunder each afternoon and evening.
Upper low moves E over the area Mon. night and there will be a SE
low-level jet. Again, higher PoPs were central and W, with a
slight chance in the E. Highs will remain in the 50s and 60s both
days.
Will continue the ESF for possible rises next week on the rivers W
of KBIL. Arthur
.LONG TERM...valid for Tue...Wed...Thu...Fri...Sat...
Wet and unsettled weather looks to continue through the long term
as a cut-off low over the northern Great Basin meanders, and
slowly shifts east over time. Waves of energy are progged to move
over the region with upslope flow at the surface most days. The
energy interacting with modest moisture advecting into the region
from the south will produce periods of showers and thunderstorms
over the forecast area. As has been the case, models continue to
struggle with the precipitation amounts and placement due to the
convective nature. With warm temperatures aloft, the majority of
the precipitation looks to fall as rain, although the higher peaks
in the Beartooth/Absaroka mountains could see some snow. Will
continue to monitor for potential impacts the precipitation may
have on area rivers especially the Clarks Fork of the Yellowstone
at Edgar and Belfry where flood stages may be reached late Monday
into Tuesday.
High temperatures look to be below normal Tuesday and Wednesday
with 60s to lower 70s expected. Readings then will warm to normal
and slightly above Thursday into Saturday with upper 70s to around
80 degrees common. STP/Hooley
&&
.AVIATION...
Isolated showers and thunderstorms will continue through the
remainder of the afternoon and through the overnight hours.
However, widespread heavy rain is not expected through tonight.
MVFR conditions will prevail with occasional IFR conditions
through the night mainly due to low ceilings. Mountain
obscurations will be likely through the period. Hooley/AAG
&&
.PRELIMINARY POINT TEMP/POPS...
Sun Mon Tue Wed Thu Fri Sat
-----------------------------------------------------------
BIL 049/060 052/062 052/067 053/071 054/076 056/078 056/078
24/T 67/T 74/T 55/T 34/T 32/T 33/T
LVM 045/057 047/059 047/063 048/067 048/074 048/075 049/075
26/T 67/T 65/T 54/T 24/T 22/T 33/T
HDN 050/064 051/068 051/071 054/073 052/078 055/079 055/080
23/T 46/T 74/T 54/T 33/T 32/T 33/T
MLS 051/067 053/069 055/072 056/074 056/078 058/079 058/080
22/T 23/T 33/T 33/T 22/T 22/T 22/T
4BQ 053/064 052/069 052/072 053/073 054/078 056/078 056/079
33/T 34/T 24/T 44/T 23/T 32/T 22/T
BHK 049/066 049/069 050/072 052/075 053/077 054/078 054/079
22/T 12/T 22/T 23/T 22/T 21/B 12/T
SHR 049/060 050/067 049/069 051/070 049/075 052/075 052/075
35/T 55/T 65/T 64/T 44/T 33/T 43/T
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...None.
WY...None.
&&
$$
weather.gov/billings
Area Forecast Discussion
National Weather Service State College PA
1104 PM EDT Sat Jun 16 2018
.SYNOPSIS...
Mid summer-like heat and humidity will build in for Sunday and
Monday before a cold front cools things down for the middle of
next week.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
A few showers over Armstrong County are heading SE toward
the Laurel Highlands leading to the near term update nudging
POPs up slightly. The airmass is stable and the lapse rates are
weak and the HRRR shows these showers staying scattered and
disorganized. The remainder of the CWA should remain dry
overnight.
Lows will drop back into the upper 50s to lower 60s with
dewpoints on the comfortable side in the 50s. There may be some
patchy light fog in river valleys toward morning.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
Temperatures will ramp up on Sunday along with dewpoints rising
through the 60s. Very warm mid level air will act as an
effective cap for most of the region Sunday despite the increase
in humidity. The best chance for a shower or storm will be over
the south on the northern edge of the cool pocket aloft.
Highs will soar into the mid 80s to around 90 over the SE.
&&
.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
Dominant high pressure over the Mississippi valley will allow
for a ridge to remain entrenched over the Mid Atlantic region
through Monday. This will continue hot weather through Monday
with high temperatures in 90s. With dewpoints in the 70s the
danger of heat-related illnesses will enter the picture on
Monday as the heat index rises into the 90s everywhere, and near
or above 100 in the SErn valleys. The highest area of concern
will be urban regions in the SE.
While the heat index does not look to exceed 105 (warning),
there is a potential an advisory may be needed.
The previously mentioned broad and anomalous upper ridge will
dominate the pattern through most of Monday as relatively slow
moving low located in northern Canada drags a cold front through
the region Monday night through Tuesday. This should allow for
periods of showers Tuesday into Tuesday night. The 12Z long
range models now have the precipitation exiting mid to late
Wednesday, however the boundary could linger along the southern
border which could allow for precipitation into Thursday. Have
adjusted the POPS accordingly.
With the Maximum temperatures forecasted to be 10 to 15
degrees above normal on Monday, the cold front will drop
temperatures back to around normal through the rest of the week.
&&
.AVIATION /03Z SUNDAY THROUGH THURSDAY/...
A weak area of low pressure over Ohio will drift southeast this
evening, perhaps accompanied by a stray shower over southwest
Pennsylvania. However, the main concern will be the potential of
late night fog. Current model guidance suggests there will be
enough cloudiness associated with the aforementioned low
pressure system to limit radiational cooling and fog potential.
However, can`t rule out some localized visibility reductions
around dawn. Late evening dewpoint depressions, as well as
SREF/NAMNest, suggest northwest Pa (KBFD) stands the best
chance of significant vis reductions.
High pressure building in from the Ohio Valley should ensure
widespread VFR conditions and light wind Sunday. KLNS may have density
altitude concerns Sunday afternoon, as heat creeps into the
area.
.Outlook...
Mon...Patchy AM fog possible. High temperatures with density
altitude issues in the afternoon. Evening tsra impacts possible
north.
Tue...Early AM low cigs possible KBFD/KJST. Isold tsra impacts
possible southern tier.
Wed-Thu...Chance of showers/cig reductions southern Pa.
&&
.CLIMATE...
Record max temperatures for June 18th:
Harrisburg:97 in 1957
Williamsport: 97 in 1994
Altoona:92 in 1994
Bradford: 87 in 1994
State College:94 in 1923
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SYNOPSIS...La Corte
NEAR TERM...La Corte
SHORT TERM...Dangelo
LONG TERM...Ceru/Steinbugl
AVIATION...Fitzgerald
CLIMATE...
Area Forecast Discussion
National Weather Service Cheyenne WY
857 PM MDT Sat Jun 16 2018
.UPDATE...
Issued at 831 PM MDT Sat Jun 16 2018
Cancelled Severe Thunderstorm Watch 181 for our western NE Panhandle
counties as convective intensity and coverage trends have decreased
since 730 PM. HRRR models show an uptick in convection once again
after midnight tonight, with locally heavy rainfall possible. Cannot
rule out brief gusty winds in and near thunderstorm activity.
UPDATE Issued at 305 PM MDT Sat Jun 16 2018
...SEVERE THUNDERSTORM WATCH 181 IN EFFECT UNTIL 11 PM MDT THIS
EVENING. THIS INCLUDES THE FOLLOWING COUNTIES...
IN THE PANHANDLE OF NEBRASKA
BANNER BOX BUTTE DAWES
KIMBALL MORRILL SCOTTS BLUFF
SIOUX
IN SOUTHEAST WYOMING
GOSHEN LARAMIE
The environment across southeast Wyoming and western Nebraska has
become favorable for isolated severe storms this afternoon and
evening. Large hail and damaging winds will be the main threats
with any severe storms. More storms should develop along a stalled
stationary front in the Nebraska panhandle this afternoon and
evening.
&&
.SHORT TERM...(This evening through Sunday)
Issued at 107 PM MDT Sat Jun 16 2018
Main threats for today are the chance for severe storms this afternoon
and the heavy rainfall and possible flooding tonight. Aloft an
upper low was moving over the Great Basin. The 19z Surface
analysis showed a stalled stationary front over the western
Nebraska Panhandle. Pooled along the front was very deep moisture
with dewpoints in the middle 60s. Regional soundings and satellite
obs showed a well defined atmospheric river from the remnants of
Hurricane Bud. This mid level moisture and cloud cover will make
its way over the northern plains this afternoon and evening.
Showers and thunderstorms are expected to develop along the
stationary front this afternoon in an informant characterized by
moderate instability and deep layer shear. This should lead to
organized convection capable of damaging winds and large hail.
More storms will develop tonight over the mountains of northern
and central colorado moving north into southern Wyoming. These
storms will be tapping into abundant tropical moisture with 700 mb
mixing ratios over 12g/kg. These likely low topped storms will be
capable of very heavy rainfall up to several inches per hour in
the most intense cores. Heavy rainfall overnight and through
Sunday prompted a Flash Flood Watch as models show QPF well above
an inch for most areas with higher amounts possible where storms
move through.
.LONG TERM...(Sunday night through Saturday)
Issued at 107 PM MDT Sat Jun 16 2018
Thunderstorms will continue Sunday night before dissipating
Monday morning. Another round of storms is expected to develop
over the mountains and move east Monday afternoon as the upper low
cuts off over the Four Corners region. This will begin a week of
unsettled weather as multiple rounds of showers and storms move
through. Abundant moisture will exist through the week suggesting
a continued threat of heavy rainfall. In addition to the heavy
rain, temperatures will plunge compared to recent trends. Daytime
high temperatures will be limited to the 50s or the 60s across
southeastern wyoming and western nebraska. This is quite a
significant change compared to the 80s and 90s we have seen over
the last few days. Unsettled weather will continue in the long
term as a series of upper level troughs move across northern
Wyoming
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday afternoon)
Issued at 1238 PM MDT Sat Jun 16 2018
SHRA/TSRA coverage and intensity has decreased this evening,
however it will increase once again after midnight and persist
through Sunday afternoon. The majority of the short range models
forecast MVFR to IFR CIGS/VIS later tonight through Sunday, and
this will be maintained for the 06Z TAF.
&&
.FIRE WEATHER...
Issued at 107 PM MDT Sat Jun 16 2018
Fire Weather concerns will be low as a very wet and active period
develops this weekend amid a stalled front and ample tropical
moisture. The ongoing Badger Creek fire will likely see wetting
rain through the weekend which could lead to flash flooding on the
burn scar.
&&
.HYDROLOGY...
Issued at 107 PM MDT Sat Jun 16 2018
Deep moisture from the remnants of Hurricane Bud and a stalled
front will bring several rounds of showers and thunderstorms to
southeast Wyoming and western Nebraska this afternoon through
this weekend. The deep tropical moisture will lead to very
efficient rain producing cells capable of multi-inch per hour
rainfall rates. Flash Flooding will be possible through this weekend.
Of particular concern is the burn scar from the ongoing Badger Creek
Fire. Any storms that move over this area will need to be watched
closely as excess runoff from the burn scar could rapidly inundate
adjacent basins. The other area of interest will be along a stalled
frontal boundary through the Nebraska panhandle. Training cells
could produce heavy rainfall across this area through the weekend.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...Flash Flood Watch through Sunday afternoon for WYZ114.
Flash Flood Watch from midnight MDT tonight through Sunday
afternoon for WYZ107-108-118.
NE...Flash Flood Watch from midnight MDT tonight through Sunday
afternoon for NEZ002-003-019-095-096.
&&
$$
UPDATE...MAJ
SHORT TERM...ADL
LONG TERM...ADL
AVIATION...MAJ
FIRE WEATHER...ADL
HYDROLOGY...ADL/MAJ
Area Forecast Discussion
National Weather Service Dodge City KS
626 PM CDT Sat Jun 16 2018
...Updated Aviation Discussion...
.SHORT TERM...(This afternoon through Sunday)
Issued at 1200 PM CDT Sat Jun 16 2018
Widespread thick cirrus, associated with the remnant outflow
circulation aloft of the former Pacific hurricane Bud, has
overspread SW KS as of midday. Despite the cirrus this afternoon,
temperatures will still warm well into the 90s, and south winds
will again be strong, gusting 40-45 mph.
An interesting forecast scenario unfolding for tonight. 12z NAM
develops widespread convection, associated with the remnant Bud
circulation, through 7 pm across SE Colorado to NE New Mexico.
This development is already beginning per satellite imagery across
eastern New Mexico as of noon. The NAM is by far the most bullish
model with this development, and its eastward advance into SW KS
tonight, with very heavy rainfall depicted. Evidently, 12z NAM is
picking up on some spurious vorticity max in the remnant tropical
circulation, interacting with a very moist atmosphere
(precipitable water to 1.8"). While moist, instability on NAM is
quite poor, to be expected in a moist adiabatic tropical
environment, with CAPE only near 500 J/kg. Was ready to discount
the 12z NAM wet solution, but now the 12z GFS is picking up on
something very similar, spreading moderate to heavy rain west of
US 83 through midnight before weakening. Given this agreement, and
strong support from HRRR and other CAMs, had no choice but to
increase pop grids dramatically into the likely category across
the western zones this evening. Additional increases to the
chance/scattered category were necessary further eastward tonight,
as the anticipated band of rain/thunder weakens. Have high
confidence on rain tonight for the western zones (some of it
heavy), but have very low confidence on how far east this rain
will advance. Additional refinements in pop/QPF grids expected.
Temperatures tonight will struggle to fall in a moist/cloudy
airmass, with many locations holding above 70 through Sunday
morning.
Any rainfall will dissipate rapidly around sunrise Sunday. Strong
south winds will return once again after 10 am, averaging
25-35 mph, ahead of a cold front draped from near Limon Colorado
to near North Platte Nebraska by 7 pm. Rich moisture and modest
instability along the prefrontal trough will likely yield
scattered thunderstorm development Sunday afternoon. With weak
shear, severe hail/wind is not expected, but with high PWs and a
remnant tropical airmass sticking around, locally heavy rainfall
is likely.
.LONG TERM...(Sunday night through Saturday)
Issued at 217 PM CDT Sat Jun 16 2018
The daylight hours on Monday will be dry for most locations, as a
weakening/stalling frontal boundary sags into the region. 12z
ECMWF drapes this front across the N/NE zones Monday evening, and
favors the NE zones near Hays for convective development. This
matches well with SPCs Day 3 marginal hail/wind probabilities. Pop
grids favor the eastern counties, and are confined mainly to the
evening hours. With the front in vicinity weakening the pressure
gradient, we will finally enjoy a break from the Kansas winds on
Monday, reduced to 10-20 mph. Still plenty warm with highs in the
lower 90s.
Synoptic pattern for Tuesday and Wednesday continues to look
interesting. 12z MEX guidance continues to crank pops into the
likely range (60-70%) during this time frame, and these values
were accepted for the forecast. Locally heavy rain is likely, as
a stalled frontal boundary interacts with a moist atmosphere and
disturbances in westerly flow aloft. Around a closed 577 dm 500 mb
low in Montana, ECMWF depicts various shortwaves ejecting over
the plains late Tuesday through early Wednesday, resulting in
thunderstorm complexes (MCSs) across much of Kansas. Some storms
may be severe with hail/wind potential, given the boundary and
improved shear, but the main message is another opportunity for
beneficial rainfall. Additionally, heights and thickness begin to
drop off on Tuesday, yielding milder afternoon highs in the upper
80s.
By Wednesday, a rather odd synoptic pattern for June is evident,
with a closed low over Nebraska. Associated cold front will
approach the northern zones by late day, but even without that,
heights and thicknesses will continue to decline, forcing
temperatures to remain more squarely in the milder 80s. Pending
cloud cover, some locales may hold in the 70s as some bias-
corrected guidance suggests.
Closed low is forecast to drift into the Corn Belt Thursday and
Friday, keeping NWly flow aloft, and preventing heat from
returning. Afternoon temperatures in the 80s will be common.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 623 PM CDT Sat Jun 16 2018
Low level winds over the next 12 hours will behave much like the
last two days. The gusty south to southeast winds at 20 to 25
knots early this evening will fall back to around 15 knots by
midnight. Also overnight the south winds in the 1500 to 2000ft
level will increase to greater than 40 knots after midnight based
on the latest RAP and NAM BUFR soundings. Low level wind shear
criteria at this time however it will be close. As a result will
still include low level wind shear into the 00z TAFS. Clouds will
be on the increase overnight across western Kansas along with a
chance for thunderstorms, especially along and west of Highway
283. Also along with the chance for thunderstorms the ceilings are
also expected to lower into the MVFR category at Garden City,
Liberal, and even Dodge City between 06z and 15z Sunday. Moderate
to brief heavy rainfall possible so visibilities as low as 1-2
miles can be expected at times in the steadier and heavier
showers.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 74 94 72 93 / 30 20 10 20
GCK 72 92 68 91 / 60 20 10 10
EHA 65 90 64 90 / 80 10 10 10
LBL 72 92 69 92 / 60 30 20 10
HYS 76 94 72 91 / 20 20 20 10
P28 76 96 74 95 / 10 10 0 20
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Turner
LONG TERM...Turner
AVIATION...Burgert
Area Forecast Discussion
National Weather Service Duluth MN
957 PM CDT Sat Jun 16 2018
.UPDATE...
Issued at 956 PM CDT Sat Jun 16 2018
Issued a severe thunderstorm watch for much of the area as storms
begin to form north of a warm front.
UPDATE Issued at 638 PM CDT Sat Jun 16 2018
Updated aviation section below for the 00Z TAF update.
&&
.SHORT TERM...(This evening through Sunday)
Issued at 442 PM CDT Sat Jun 16 2018
Forecast focus today into Sunday will continue to be on strong to
severe storm potential and a risk for flash flooding.
A nearly stationary frontal boundary extended from north central
Minnesota into western Nebraska. Southerly 925mb to 850mb winds were
from 25-35 knots per area VWPs and expected to increase tonight
keeping strong moisture transport into much of the Northland. A
large pool of very unstable air was over the southern half of the
Northland and points south. A few showers and thunderstorms will
remain possible into the late afternoon hours but coverage will be
ramping up through the evening and overnight hours. Storms should
become likely and track east-northeast through the Northland. Some
of the storms could be severe, especially over our
southwest/southern zones including Cass/Crow Wing/Aitkin Counties
this evening. All modes of severe weather will be possible in those
areas through the evening with hail/damaging winds most likely
further north and east of there. In addition, copious amounts of
moisture is available making storms very efficient at producing heavy
rain. Flash flooding will be a threat and we expanded the Flash
Flood Watch to include southern Itasca, Cass, and Crow Wing Counties
into Sunday morning. Many areas of the Northland have received
significant rainfall over the past 24-36 hours leading to saturated
soils.
The showers/storms are expected to diminish in coverage Sunday
morning for a time but additional development will occur Sunday
afternoon/night as the frontal boundary finally makes some movement
to the southeast. Another round of severe storms and very heavy
rainfall will be possible over the Northland, with the severe threat
greatest over east central Minnesota into northwest Wisconsin.
.LONG TERM...(Sunday night through Saturday)
Issued at 442 PM CDT Sat Jun 16 2018
A stormy period is anticipated Sunday night and Monday morning, with
severe storms and flash flooding very much possible. A much drier
period of weather is forecast over the Northland through much of the
upcoming week, along with temperatures remaining near or above
seasonal normals.
The overall weather pattern doesn`t change much through the first
half of the long-term period, with a mid-level ridge settled over
the southeastern United States, and a longwave trough remaining over
the Intermountain West states. The upper-level low associated with
this trough will become cut-off and continue to churn over the
western states through mid-week. Initially, this longwave trough
will eject a few shortwaves into the Northland, which should keep
our weather active through Monday morning, mainly for our northwest
Wisconsin counties. A low-level baroclinic zone and FGEN forcing
will remain to support showers and thunderstorms, some of which
could be strong to severe. However, there are still some questions
regarding the magnitude of instability as the synoptic scale
guidances varies significantly. The NAM appears to be an outlier,
with MLCAPE values rising over 3000 J/kg, and the GFS, ECMWF, and
GEM models all going between 500 to 1500 J/kg. Considering the
better agreement with the latter three models, I`m thinking that
severe storms will remain isolated to scattered in nature, and only
confined to our Wisconsin counties where the better instability will
remain. However, confidence is still fairly high for some heavy
rainfall through Sunday night, particularly over areas of northwest
Wisconsin that already have saturated soils due to the precipitation
these last few days. Pwat values between the GFS and NAM models
continue to prog between 1.6 to 2.1", which according to the NAEFS
mean Pwat climatological anomalies are above 99% of climatology, and
perhaps even close to record values, so flash flooding will remain a
big concern for this time frame. On top of that, forward propagation
Corfidi vectors indicate storm motion right along the orientation of
the low-level baroclinic zone, so training convection is also very
possible.
Things will begin to dry out by late Monday morning as the low-level
baroclinic zone shifts southward. Once this occurs, the overall
synoptic pattern begins to change slightly to allow mid-level
ridging to build into the region. Surface high pressure will then
build into the region, and keep conditions mostly dry through
Thursday. There could be a weak shortwave that ejects across
southern Minnesota, which may graze our southern tier of counties
Monday night and Tuesday morning, but any rainfall amounts should
remain on the lighter side. Light winds are anticipated through much
of the upcoming week due to the high pressure overhead, and high
temperatures in the upper 70s to lower 80s over much of the region.
Eventually, the upper-level ridge over the southeastern U.S. will
flatten out, allowing the trough over the Intermountain West to
advance eastward and bring a shortwave with a decent positive
vorticity maxima with it, so the forcing will be more supportive of
showers and storms for the Friday and Saturday time frame. However,
confidence is fairly low due to differences in the placement of the
shortwave between the GFS/ECMWF/GEM models. So, will lean on the
consensus blends for now, which have only small chances.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 638 PM CDT Sat Jun 16 2018
Not a whole lot of change to this package as we`re still in the
sit and wait mode in regard to how/when/if thunderstorms develop.
They look likely tonight moreso than last night, but they still
have to overcome some capping. HRRR continues to show widespread
thunderstorms overnight with a tapering off by morning. Fog around
Lake Superior with a warm, moist air mass in place while LLWS
sneaks in from the west as well.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 59 81 58 73 / 80 70 60 20
INL 59 72 51 77 / 60 30 10 0
BRD 68 80 59 77 / 80 70 50 20
HYR 67 88 61 74 / 60 70 80 30
ASX 60 84 57 71 / 70 70 80 20
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
WI...Flash Flood Watch through Monday afternoon for WIZ001>004-
006>009.
MN...Flash Flood Watch through Monday afternoon for MNZ019-035>038.
Flash Flood Watch until 8 AM CDT Sunday for MNZ025-026-033-034.
LS...None.
&&
$$
UPDATE...Wolfe
SHORT TERM...Melde
LONG TERM...JTS
AVIATION...Wolfe
Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
1015 PM EDT Sat Jun 16 2018
.SYNOPSIS...
Hot high pressure will gradually build atop the region through the
middle of next week. Mainly scattered afternoon and evening
thunderstorms are expected each day, focusing over the mountains.
Moisture will increase towards the end of next week as a weak
frontal boundary sags toward the area.
&&
.NEAR TERM /THROUGH SUNDAY/...
As of 1000 PM: Convection just won`t give up over the Upstate; a new
cluster of t-storms has developed between Anderson and Greenville,
despite this area having been worked over by another cluster this
afternoon. Further north, cells developed near or after sunset over
the NC mountains/foothills but those seem to be on the downswing
for now. New PoPs continue to be as broad-brush as possible while
still recognizing that we can fairly confidently say that some
of the area (particularly the NC Piedmont and eastern Upstate)
will be dry thru the night. Unfortunately the hi-res guidance
is not representing reality very well. The latest HRRR wants to
keep the western Upstate cluster going for several more hours,
but that does seem like a stretch given that this is the second
round. Nonetheless a slow decline is anticipated from the current
coverage. Outflows are not as evident on radar, a good sign if
you want the precip to come to an end, but that could be a result
of less pronounced differences between the new outflows and the
cooler (in some cases, previously rain-cooled) air they are pushing
into. Also revised overnight temp/dewpoint trends now that cooling
has slowed, though new mins are close to the previous fcst.
Sfc moisture is a bit greater tonight than the past couple
nights. With clearing skies later tonight, patchy fog is expected to
develop over the mountain valleys, parts of the northern foothills,
and areas that received appreciable precip. Min temps will remain
1 to 2 categories above normal. Otherwise, a broad upper trof will
shift farther east off the Atlantic Coast as broad upper ridging
builds across the Eastern CONUS. At the sfc, high pressure will
also shift farther east and move offshore tomorrow, keeping the
fcst area under warm SLY to SWLY low-lvl flow. Much like today,
scattered convection is likely again tomorrow with similar areas
favored. A few thunderstorms that develop could become severe with
locally damaging straight-line winds and/or large hail. High temps
will be a bit warmer than today`s, with values in the low 90s across
the lower terrain and mid to upper 80s across the higher terrain.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
As of 215 PM Saturday: Sprawling high pressure will dominate the
eastern half of the country Monday through Wednesday, but with some
flattening of the upper ridge on Wednesday. Very hot temperatures
will be the main issue, with max temps in the mid to upper 90s east
of the mountains pushing Heat Index values into the 100 to 105 range
each day.
Diurnal convection will develop mainly along the Blue Ridge again on
Monday and Tuesday afternoon given the robust instability, and
possibly move into the adjacent foothills before dissipating during
the evening hours. The flattening ridge will permit a bit more
westerly steering flow which could bring a few more scattered
thunderstorms east into the piedmont from the mountains late day. A
few damaging wind and large hail storms will be possible despite the
warm profiles.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
As of 200 PM Saturday: The medium range picks up at 00Z Thursday
with a slight change in the upper pattern from earlier in the week.
The center of the upper subtropical ridge will be shifting off the
east coast by late Friday, though with an upper blocking pattern in
place over the central CONUS, heights will only fall marginally
through the weekend. Though a slight decrease in temperatures may
seem optimistic, increasing low-level moisture plus decreased deep-
layer mixing could very well result in heat indices staying near
levels seen earlier in the week. At this point, though, it does not
appear that heat indices will meet excessive heat criteria. Those
spending time outside through the end of next week should continue
to take caution,however, considering this is the first string of
extended very hot temperatures this year. Min temperatures will
actually increase through the period as well, which can be a factor
in increasing the risk of heat illness.
A frontal boundary associated with an upper trough over the
northeastern CONUS will sag southward closer to our area each day of
the medium range, possibly finally making it by Saturday. This
represents a departure from previous thinking, as global models were
in poor agreement on the progression of the front. Frontal placement
still remains uncertain, though at this point no significant airmass
modification is expected through next weekend and hot and humid
conditions will remain. Diurnal shower and thunderstorm activity
will become enhanced through the medium range as the approaching
frontal boundary provides a source of convergence/lift nearer to our
area.
&&
.AVIATION /02Z SUNDAY THROUGH THURSDAY/...
At KCLT and elsewhere: Heavy rain fell at KGMU this afternoon, and
very near KGSP and KAND. With surface dewpoint depressions expected
to be small and wet soils, periods of IFR are possible at KGMU,
and MVFR at KGSP/KAND. The other TAF sites should remain clear
of restrictions. Though remnant outflow has left winds perturbed
as of 00z, by late evening a very light SW flow should prevail
across the area, though KAVL may flip to light NW for a time. SW
winds redevelop everywhere Sunday. Scattered TSRA are expected
to develop, mainly over the mountains and western Upstate, but
warranting a mention at all sites except KHKY.
Outlook: Typical summertime potential for diurnally-driven showers
and thunderstorms will persist into midweek, with very hot and
humid conditions. Some morning fog will also be possible in the
mountain valleys and over lakes each day. Chances for precip look
greater late in the week as the ridge bringing the hot weather
begins to break down.
Confidence Table...
02-08Z 08-14Z 14-20Z 20-00Z
KCLT High 100% High 100% High 100% High 100%
KGSP High 100% High 100% High 100% High 100%
KAVL High 90% High 100% High 100% High 100%
KHKY High 100% High 100% High 100% High 100%
KGMU High 100% High 87% 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...HG
NEAR TERM...JPT/Wimberley
SHORT TERM...HG
LONG TERM...Carroll
AVIATION...Wimberley
Area Forecast Discussion
National Weather Service Northern Indiana
924 PM EDT Sat Jun 16 2018
.SYNOPSIS...
Issued at 740 PM EDT Sat Jun 15 2018
Hot and humid weather will persist through the remainder of the weekend
as an upper level ridge remains over the region. An isolated
storm remains possible into this evening along and south of Route
30 across mainly northwest Indiana. Otherwise no rain is expected
through Monday morning. Lows tonight will only drop into the
lower 70s, with highs back into the mid 90s for Sunday, along with
afternoon heat indices around 100.
&&
.UPDATE...
Issued at 916 PM EDT Sat Jun 16 2018
A few isolated storms developed this evening across northwest
Indiana and northwest Ohio. These storms developed along an
outflow boundary which was reinforced by lake breeze across
northwest Indiana. As of 01Z, last of storms persists across Allen
county Ohio. This storm did produce some pea sized hail in the
Ottoville area over the past hour. A downward trend has been noted
over the past hour and should see threat of storms diminish
shortly as surface based CIN develops. No major changes to
previous forecast other than minor tweaks to PoPs to account for
lingering isolated storms through 03Z.
&&
.SHORT TERM...(This Evening through Sunday)
Issued at 400 PM EDT Sat Jun 16 2018
Outflow boundary has slowed considerably, oriented from south of
Valparaiso to near Fort Wayne. While plenty of instability
exists, the few showers that have tried to form have struggled
against a strengthening inversion.Cu field slowly losing the fight
as well with vis sat showing less in the way of towering cu. Not
completely out of the woods for storms as we head towards evening
and the inversion weakens slightly with normal diurnal trends.
HRRR remains consistent in rapid development of storms along this
boundary. Will maintain slgt chc to chc pops in the SW areas into
early evening.
After this the heat will dominate as ridge continues to build into
the region with the hottest day so far (and maybe in a while) in
store for the area. Overnight lows will drop into the upper 60s to
lower 70s. This will give a great platform for temps to skyrocket
under what should be mostly sunny skies with highs reaching into
the middle 90s. Concerns have lingered about dewpoints, but with
upstream dewpoints across Illinois into central IN into the middle
70s see no reason it won`t come in to the area. After much
discussion with surrounding offices have hoisted heat advisory for
the entire area. Headlines may be needed into the long term
period, but didn`t want to lock next shift into anything further
at this point.
&&
.LONG TERM...(Sunday Night through Saturday)
Issued at 400 PM EDT Sat Jun 16 2018
Heat and humidity will continue into at least Monday with
overnight lows Sunday night in the mid 70s and highs Monday in the
lower to middle 90s. Areas south of US-30 could see heat indices
approach criteria once again but as noted in short term will not
issue anything beyond Sunday. Heat and humidity will become less
of a concern for the work week.
Frontal boundary will sink south into the area Tuesday as ridge
begins to lose its influence and flatten some. Weak disturbances
will ride along the edge of the ridge the remainder of the
forecast period to bring chances of precip. The best chances at
this point looks to be Tues into Tuesday night as well as towards
the end of the period when most pronounced waves move in.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday Evening)
Issued at 740 PM EDT Sat Jun 16 2018
The threat of showers and thunderstorms has diminished across the
terminals early this evening. Earlier outflow boundary which
dropped south of the terminals has shown some signs of slight
northward retreat. An isolated shower has developed along this
boundary over the past hour to the southwest of KPPO in northwest
Indiana. This boundary may trend to continue to lift northeast
over the next few hours, although some surface based CIN will be
developing after sunset which will limit additional shower
potential. Bulk of shower and thunderstorm coverage has been
confined to OH/east central IN, in association with weak MCV that
emanated from earlier convection. With this forcing mechanism not
likely to affect terminals, will go with a dry terminal forecast
this evening. Moderate sfc based instability expected to develop
on Sunday, although magnitude of instability will be more
tempered due to slightly weaker mid level lapse rates. Gradient
should provide southwest winds in the 10 to 15 knot range with
diurnal mixing by mid morning Sunday. VFR conditions are expected
to persist throughout this forecast cycle.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...Heat Advisory from 11 AM EDT /10 AM CDT/ to 8 PM EDT /7 PM CDT/
Sunday for INZ003>009-012>018-020-022>027-032>034.
MI...Heat Advisory from 11 AM to 8 PM EDT Sunday for MIZ077>081.
OH...Heat Advisory from 11 AM to 8 PM EDT Sunday for OHZ001-002-004-
005-015-016-024-025.
LM...NONE.
&&
$$
UPDATE...Marsili
SYNOPSIS...Marsili/Fisher
SHORT TERM...Fisher
LONG TERM...Fisher
AVIATION...Marsili
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Area Forecast Discussion
National Weather Service Paducah KY
512 PM CDT Sat Jun 16 2018
.UPDATE...
Issued at 509 PM CDT Sat Jun 16 2018
Updated Aviation discussion for 00Z TAF Issuance.
&&
.SHORT TERM...(Tonight through Monday night)
Issued at 241 PM CDT Sat Jun 16 2018
Most of the region has reached 100 heat indices as of 19Z, with the
exception of west Kentucky where readings are only in the upper 90s.
The current heat headlines look good at this point and do not plan
on any adjustments at this time.
A decent cu field has developed and a few isolated showers have
developed on opposite ends of the CWA. The latest CAM guidance
really does not show much, but the bottom line is that very
isolated thunderstorms cannot be ruled out over much of the
region through the remainder of the afternoon. We will maintain
the slightest of PoPs for it.
Tonight will be dry with light or calm winds. This should allow
temperatures to drop into the lower 70s, if not the upper 60s in
some locations, which should provide some relief from the heat.
Given the good radiational cooling conditions, some patchy light fog
will be possible.
Despite the mid and upper-level ridge holding strong over the area
12Z NAM and GFS soundings indicate a little better chance of deep
convection developing Sunday afternoon over southern portions of
the region and Monday as well. This is not saying much, but will
result in a very slight chance diurnal PoP over mainly southern
portions of the area each day.
Afternoon heat indices will climb into the 100-105 range Sunday
and Monday. The lone exception may be the southern Pennyrile. We
may need to consider expanding the Heat Advisory based on the
4-day 100+ threshold, but we will let the midnight shift consider
this further.
.LONG TERM...(Tuesday through Saturday)
Issued at 241 PM CDT Sat Jun 16 2018
Relatively good agreement among operational and ensemble model
solutions lends to somewhat higher than average confidence in the
overall synoptic pattern during the long term. This confidence is
tempered by less certainty over more specific temporal and spatial
placement of precipitation chances inherent in the type of pattern
forecast.
Starting with Tuesday, the upper level ridge over the southeastern
U.S. will be in the process of breaking down as energy from an upper
low over the Great Basin begins to spread east into the Plains.
Nevertheless, the influence of the ridge should keep much of Tuesday
dry, with only isolated thunderstorm chances primarily during the
heat of the day. It will be another hot one with highs forecast in
the lower 90s on Tuesday and lows Tuesday night from 70 to 75.
From Wednesday through the remainder of the week, the increasing
influence of energy approaching from the Plains paired with a weak
stationary frontal boundary draped just north of the forecast area
should help to focus greater shower and thunderstorm coverage. Even
though better chances should stay aligned with peak diurnal heating,
chances really cannot be ruled out at any time given the proximity
of the nearby frontal boundary and timing of individual vorticity
maxima. Very warm and muggy conditions are expected to persist with
forecast highs in the upper 80s to near 90 and lows in the lower
70s.
&&
.AVIATION...
Issued at 509 PM CDT Sat Jun 16 2018
Diurnally fueled convection is most active in our east, which
means KEVV and KOWB terminals may carry categorical or vicinity
mention. HRRR diminishes threat by 03Z, so after that all sites
return VFR xcp for chance late night/daybreak Fog, with MVFR
potential restrictions to Vsbys. Tmrw should be near repeat of
today with diurnal cu again developing by late morning/extending
into thru the pm/planning period hours and isolated convective
chances as well.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...Heat Advisory until 7 PM CDT Monday for ILZ075>078-080>094.
MO...Heat Advisory until 7 PM CDT Monday for MOZ076-086-087-100-
107>112-114.
IN...None.
KY...Heat Advisory until 7 PM CDT Monday for KYZ001>011.
&&
$$
Area Forecast Discussion
National Weather Service Tucson AZ
310 PM MST Sat Jun 16 2018
.SYNOPSIS...Scattered showers and isolated thunderstorms mainly east
to south of Tucson ending by daybreak Sunday. Dry conditions
will return Sunday and continue into next Saturday. A warming trend
will also begin Sunday with daytime temperatures warming to above
seasonal normals by next weekend.
&&
.DISCUSSION...Scattered showers with isolated thunderstorms were
occurring mainly east to south of Tucson at this time. However,
other isolated showers were also ongoing north of Tucson across
southeast Pinal County, and to the southwest of Tucson. Several HRRR
solutions suggest that the bulk of measurable rainfall will end
across this forecast area by midnight. For this forecast issuance,
have opted to maintain a slight chance of showers east of Tucson
late tonight.
However, this mention/depiction of showers may be removed from the
official forecast with the evening shift update. Have also opted to
include patchy fog late tonight into early Sunday morning for the
lower elevations of the Tucson metro area, Santa Cruz County and the
Upper San Pedro River Valley. These areas received fairly
substantial rainfall during the past 24 hours and clearing skies
later tonight should enhance the potential for fog formation.
The 16/12Z deterministic GFS/ECMWF and their respective ensembles
were quite similar regarding the progged upper pattern over the
western CONUS starting Sunday and continuing into next Saturday.
Increasing westerly flow aloft Sunday in response to a fairly deep
low pressure centered over the Great Basin will shunt deeper
moisture well east of this forecast area.
Thus, clouds will gradually decrease Sunday followed by clear skies
most sections Sunday night. Clear skies or mostly clear skies will
be the rule Monday into next Saturday as high pressure aloft builds
over the Desert Southwest. The markedly drier regime in combination
with increasing heights/thicknesses will translate into a pronounced
warming trend starting Sunday and continuing into the latter portion
of this forecast period. Forecast high temps especially next Friday
and Saturday will likely be at least a few degrees above normal.
&&
.AVIATION...Valid through 18/00Z.
Scattered -SHRA and isolated -TSRA mainly east to south of KTUS
expected to end around 17/06Z. Patchy fog may develop by 17/06Z and
continue into early Sunday morning in vicinity of KTUS and KOLS.
However, forecast confidence is too low to include in the TAFs at
this time.
Otherwise, cloud decks mainly 5k-10k ft AGL thru tonight then FEW-
SCT clouds 6k-12k ft AGL Sunday. Surface wind early this evening and
Sunday afternoon swly/wly 10-15 kts with gusts near 20 kts. Surface
wind variable in direction mainly less than 12 kts at other times.
Aviation discussion not updated for TAF amendments.
&&
.FIRE WEATHER...Scattered showers and isolated thunderstorms mainly
east to south of Tucson this evening. Dry conditions will then
prevail Sunday into next Saturday. 20-foot winds during the upcoming
week will mostly be terrain driven and under 15 mph. However, some
gustiness will occur during the afternoon hours due to daytime
heating.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...None.
&&
$$
DISCUSSION...Francis
AVIATION...Pegram
FIRE WEATHER...Pegram
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