Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 06/30/17
Area Forecast Discussion
National Weather Service Albany NY
1034 PM EDT Thu Jun 29 2017
.SYNOPSIS...
As a warm front pushes northeast across our area this evening
into tonight, showers and thunderstorms are expected, mainly for
areas north of the Capital Region. Behind the warm front, a
warmer and more humid air mass will be in place for Friday into
Saturday with additional showers and thunderstorms each day,
especially in the afternoon and evening hours. Some of the
storms could be strong to severe and produce heavy rainfall. A
cold front should cross the region by Sunday, with somewhat
cooler and slightly less humid conditions moving in for early
next week.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
As of 1030 PM EDT, An area of heavy rain and convection has
developed across northern NY and is tracking eastward. Some of
these storms have moved through the far northern reaches of
Herkimer and Hamilton counties with the bulk of the activity
staying just to the north of the forecast area. However, if
the heavy rain shifts southward, flash flooding could become a
concern as storms have been producing an inch to inch and a half
per hour. Additionally, lightning has been frequent with many of
these storms so have maintained chances for thunderstorms
throughout the night. Otherwise, freshened up the hourly temps
and pops to reflect most recent trends and sent updates to NDFD
and web servers.
Prev Disc...
As of 730 PM EDT, Scattered showers continue to
track across the Adirondacks and Lake George-Saratoga region
this evening. A few thunderstorms can be seen upstream and may
hold together long enough for a few rumbles of thunder later on
tonight. Due to the ongoing shower activity, there is a stark
contrast in temperatures across eastern New York with lower 60s
in the Adirondacks versus upper 70s in the mid-Hudson Valley. So
have adjusted hourly temps to reflect these differences.
Otherwise, the forecast remains on track.
Prev Disc...
As of 419 PM EDT...A warm front is in the process of lifting
northward across upstate New York. For the areas south of the
Capital Region, winds have switched to a southerly direction and
dewpoints have been rising into the lower 60s, while more
clouds are in place for northern areas with cooler and less
humid conditions at this time.
Ahead of this boundary, areas of rain showers have been sliding
eastward from western and central New York and Lake Ontario
into the Adirondacks and points eastward. On and off showers
look to continue into the evening hours for areas north of the
Mohawk Valley and Capital Region. Although most of these showers
have been light (rainfall rates under one tenth of an inch per
hour), a few locally moderate to heavy bursts (up to a quarter
inch per hour) are possible. Cannot rule out some thunder
(especially for after 00z), but any thunder appears to elevated
thanks to a stable layer within the boundary layer, so while no
severe weather is anticipated, cannot totally rule out some
rumbles from time to time.
Hi-res guidance (including the 3km HRRR and NAM) suggest the
best chance for rain showers and/or thunder will be through
about midnight or so. After that time, showers will be more
scattered in nature, as the better forcing starts to lift
northeast of the region, as we get into the warm sector.
Otherwise, skies will be partly to mostly cloudy for this
evening into the overnight, with the most breaks across southern
areas. It will be increasingly humid and staying mild through
the overnight hours thanks to the persistent southerly flow,
with lows only falling into the 60s.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/...
Strong to Severe Thunderstorms Possible Friday and
Saturday...
With our area fully in the warm sector, a warm and humid air
mass will be in place for Friday. With some breaks of sunshine
expected, highs should reach into the low to mid 80s for valley
areas, with dewpoints well into the 60s.
Although there won`t be any major surface boundaries nearby,
subtle disturbances sliding within the flow at 500 hpa, along
with lake-breeze boundaries, could allow for some convection to
get going on early Friday afternoon over central New York. This
activity should shift eastward into eastern NY and western New
England for the rest of the afternoon and evening hours. With
plenty of instability in place (at least 1500 J/kg of CAPE for
many areas) and 0-6 km bulk shear of 30-40 kts (especially for
northern areas), some of the thunderstorms may organize into
small lines or bows and be strong to severe. Will highlight this
threat within both the HWO and forecast zones, with gusty winds
being the main threat. With PWATs also expected to be near 2.00
inches, heavy rainfall will a threat with any thunderstorms as
well, any localized flooding will be possible due to any slow
moving or training thunderstorms.
Activity should wane for Friday evening thanks to the loss of
daytime heating, but it will remain muggy and mild for Friday
night with lows in the upper 60s to near 70. Another round of
convection looks to occur once again on Saturday, and this round
may be more widespread thanks to better forcing (a nearby pre-
frontal trough). Again, enough instability/shear looks to be in
place for storms to be strong to severe, so will highlight this
day also as well. Once again, gusty winds and heavy rainfall
look to be the main threat. Temps should well into the 80s on
Saturday and dewpoints will continue to be very sticky, with
values near 70 F.
The cold front will be getting closer for Saturday night,
although it may not cross until during the day on Sunday. Some
lingering showers and embedded thunder is possible, but the
severe threat looks to be limited to just the afternoon and
evening on Saturday. Lows will continue to be mild ahead of the
front, with readings in the 60s.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
Things start out only mildly unsettled as a weak cold front passes
through on Sunday. A second weak cold front will bring perhaps some
more showers on Monday. Outside of these two periods, things will
be mainly dry as high pressure builds in.
High temperatures will range from the upper 60s to mid 80s Sunday
and Monday...the upper 60s to lower 80s Tuesday and Wednesday.
Overnight lows will be mainly in the 50s and lower 60s...very close
to normal.
&&
.AVIATION /03Z FRIDAY THROUGH TUESDAY/...
A warm front will continue to lift north through the region
this evening from the southwest. A warm and humid air mass will
become entrenched across the region Friday, along with some
scattered, mainly afternoon thunderstorms.
Generally VFR conditions are expected across all TAF sites
tonight. Some showers with embedded thunder will affect KGFL
overnight tonight. These showers may intermittently also affect
KALB/KPSF between 03Z-12Z/Fri. Brief periods of MVFR/IFR could
occur if the cores of these showers/storms pass over a location.
Some MVFR Vsbys could occur after any showers/storms occur as
well due to increased low level moisture.
For Friday, mainly VFR conditions are expected in the morning,
with areas of mid level clouds likely. By the afternoon,
scattered showers and thunderstorms are possible, and may
briefly reduce conditions to MVFR/IFR at times.
Winds will be south to southwest at 5-10 KT through Friday,
with some gusts of 15-20 KT possible this afternoon.
There is a possibility of low level wind shear tonight at KPOU
if surface winds decrease to less than 8 KT, since winds aloft
around 2000 FT AGL remain from the south/southwest and increase
to 30-40 KT.
Outlook...
Friday Night: Moderate Operational Impact. Likely SHRA...TSRA.
Saturday: High Operational Impact. Likely SHRA...TSRA. Saturday
Night: High Operational Impact. Definite SHRA...TSRA. Sunday:
Moderate Operational Impact. Chance of SHRA. Sunday Night: No
Operational Impact. NO SIG WX. Monday: Moderate Operational
Impact. Chance of SHRA. Monday Night: Slight Chance of SHRA.
Independence Day: Low Operational Impact. Slight Chance of
SHRA...TSRA.
&&
.FIRE WEATHER...
No fire weather issues are anticipated over the next few days.
There will be showers and thunderstorms moving throughout the
region on both tomorrow and Saturday, some with locally heavy
rainfall. With a humid air mass in place, RH values will
elevated each day with a south to southwest wind at 5 to 10 mph.
&&
.HYDROLOGY...
A warm front will continue to move northward across the region
this evening into tonight. Some rain showers and perhaps some
embedded thunderstorms will occur for areas north of the Mohawk
Valley and Capital Region. Although most of the rain will be
light, some occasional moderate to heavy bursts are possible,
but no flooding is expected at this time.
Additional showers and thunderstorms are possible Friday and
Saturday as well, especially during the afternoon and evening hours.
With a warm and humid air mass in place, any thunderstorm will be
capable of producing locally heavy rainfall once again. Some showers
or t-storms may be possible on Sunday as well, although the cold
front will be pushing through. It looks like mainly drier weather
will build in for early next week, although a few showers cannot be
ruled out.
By the end of the weekend, the heaviest rainfall looks to be across
areas north and west of Albany, where basin average amounts look to
be at least one to two inches of rainfall, with less rainfall south
and east. However, thunderstorms may result in locally higher totals
in some spots throughout the HSA.
For details on specific area rivers and lakes, including observed
and forecast river stages and lake elevations, please visit the
Advanced Hydrologic Prediction Service /AHPS/ graphs on our
website.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
MA...None.
VT...None.
&&
$$
SYNOPSIS...Frugis
NEAR TERM...Frugis/JVM
SHORT TERM...Frugis
LONG TERM...ELH
AVIATION...KL/JVM
FIRE WEATHER...Frugis
HYDROLOGY...Frugis
Area Forecast Discussion
National Weather Service La Crosse WI
652 PM CDT Thu Jun 29 2017
.SHORT TERM...(This evening through Friday night)
Issued at 305 PM CDT Thu Jun 29 2017
Early this afternoon a weak surface boundary extended from northern
Iowa through southern Wisconsin. Extensive anvil blow-off from
convection across Missouri has somewhat limited diurnal
destabilization south of the front but MLCAPE has been rising into
the 1000-2000 J/kg range south of the front. Surface analysis
suggests some low-level convergence over northern Iowa near the
front/outflow boundary within the instability axis with some
convection beginning to fire in this area. High-res models do
indicate this area as the focus for continued convective
development this afternoon. This convection may extend into
northeast Iowa and southwest Wisconsin. Low-level wind fields are
very weak with some slight increase in deep layer wind fields by
late today, allowing deep layer shear to reach 30-35 kts early
this evening. Some hail/gusty winds/brief heavy rains are possible
across northeast IA/southwest WI if any storms form.
This evening a shortwave trough currently evident on water vapor
imagery over South Dakota will move eastward towards the region.
High-res models generally indicate convection firing in
western Iowa and eastern Nebraska late today and spreading
eastward this evening. Model solutions have shown some variability
on the placement of this convection through the evening, but these
storms may approach from the west later this evening. Unless
storms grow upscale into a more organized complex, would expect
any storms to be weakening. Showers and a few storms will remain
possible overnight into Friday morning as upper shortwave trough
advances across the area.
The shortwave will drag the front east of the area on Friday with
broad upper troughing developing over the Upper Midwest. Behind the
departing wave, additional diurnally driven showers/storms are
possible during the afternoon/evening associated with weak upper
shortwaves within the broader troughing. CAPE could rise into the
1000-2000 J/kg rise with the drier push of air not arriving until
Saturday. However, deep layer shear will be weakening, limiting a
severe threat, with mainly pulse type storms expected. Temps will
remain a bit below average with highs mainly in the 70s to near
80. Showers/storms should diminish with loss of heating during the
evening.
.LONG TERM...(Saturday through Thursday)
Issued at 305 PM CDT Thu Jun 29 2017
Northwest flow aloft will persist through the weekend with a few
upper shortwave troughs rotating through over the region. Surface
high pressure will be building into the area on Saturday. A few
showers/storms are possible. especially over north-central
Wisconsin, but with weak instability and just subtle forcing from
any weak impulses, any showers should remain isolated.
A stronger upper wave dropping into the northern Great Lakes will
help drive a cold front south on Sunday. 29.12Z models indicate a
corridor of higher MLCAPE of 1000-2500 J/kg extending from the
central plains northeastward ahead of the front with around 40 kts
of deep shear by Sunday afternoon/evening. This could provide a
better opportunity of scattered storms, especially across the
southern half of the area, and will be a time worth watching
heading into the weekend.
For much of next week upper ridging is expected to gradually build
eastward into the Midwest. This should result in temps near
seasonal averages gradually warming towards the end of the week.
Despite the developing upper ridge, 29.12Z models indicate the
potential for an upper shortwave trough to undercut the developing
longwave ridge somewhere across the Midwest, serving as a focus
for precipitation. Confidence is quite low on this evolution at
this time, and will only mention some low rain chances at this
point.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 652 PM CDT Thu Jun 29 2017
Watching an area of showers and storms over northwest Iowa that
is ahead of a short wave trough moving across southern South
Dakota. This wave is shown by both the 29.21Z RAP and 29.18Z NAM
to continue moving east but weaken as it does. This trend is also
reflected by the 29.21Z HRRR which brings the convection east and
then rapidly weakens it east of Interstate 35 with just some
showers possibly reaching the forecast sites around midnight. For
now, will handle this with a VCSH for both airports and update if
the activity looks to be stronger as it comes in. Otherwise, VFR
conditions expected with a mid level ceiling expected through the
period. This should preclude any fog formation overnight despite
having plenty of low level moisture and light winds.
&&
.HYDROLOGY...
Issued at 305 PM CDT Thu Jun 29 2017
River flood warnings continue along the Turkey River near Elkader
and Garber following yesterday`s heavy rains. The crest has occurred
along the Turkey at Elkader while downstream near Garber the river
is near its crest just below moderate flood stage. Falling stages
are expected to continue. Scattered showers and storms are possible
at times late today into Friday with brief heavy rainfall possible
with any storms. However, widespread heavy rainfall is unlikely.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
IA...None.
&&
$$
SHORT TERM...JM
LONG TERM...JM
AVIATION...04
HYDROLOGY...JM
Area Forecast Discussion
National Weather Service Bismarck ND
926 PM CDT Thu Jun 29 2017
.UPDATE...
Issued at 920 PM CDT Thu Jun 29 2017
Cold front was on a line from Minot to Baker Montana and pushing
south and east. Convection had ended west of Minot and down along
the Montana Border. With surface low pressure in place, the
associated front, and mid level wave, cannot fully count on
showers and isolated storms completely dissipating. Have continued
low pops for the central and east and in the grids have showed a
trend of at least decreasing pops and clouds even central as the
night wears on.
UPDATE
Issued at 606 PM CDT Thu Jun 29 2017
Showers and a few thunderstorms continue to move southeast across
the region along a frontal system. While a few stronger storms
remain possible, the overall trend is for storms weakening
limiting the overall severe threat over the last hour or two.
Populated POPs based on latest HRRR runs which seem to capture the
activity the best thus far. Expect most if not all activity to be
off to our south and east by 06-08Z.
&&
.SHORT TERM...(This evening through Friday)
Issued at 240 PM CDT Thu Jun 29 2017
Cold front moving through western North Dakota this afternoon will
be the focus for increasing thunderstorms across west into
central North Dakota this afternoon and evening. While the threat
for severe weather is low, an isolated large hail or gusty wind
event is possible.
Tonight the trend will diminish then end after midnight for all
but the James River valley. Showers will linger across the Valley
Friday then end by afternoon. Highs Friday will be cool, in the
upper 60s and mid 70s.
.LONG TERM...(Friday night through Thursday)
Issued at 240 PM CDT Thu Jun 29 2017
The focus for the long term will be the very warm temperatures
expected from the Fourth of July through Thursday. Highs will
easily reach the mid 90s across the region with the GEFS plumes
indicating the potential for highs in excess of 100. With little
rain in sight the drought will likely worsen. With a broad ridge
in place its likely any weak cold front will by dry and provide
little relief from the hot weather.
&&
.AVIATION...(For the 06Z TAFS through 06Z Friday night)
Issued at 920 PM CDT Thu Jun 29 2017
A cold front from Minot North Dakota to Baker Montana will push
slowly south and east through this Thursday night. Expect
scattered showers and the small possibility of a thunderstorm
ahead of the front. Localized MVFR ceilings in and near showers
but for the most part VFR through the forecast period. After
301400Z only the KJMS TAF site will still have a chance for
convection.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JPM
SHORT TERM...WAA
LONG TERM...WAA
AVIATION...JPM
Area Forecast Discussion
National Weather Service Birmingham AL
646 PM CDT Thu Jun 29 2017
.UPDATE...
00Z Aviation Discussion.
&&
.SHORT TERM...
Fairly widespread showers and a few thunderstorms were moving
northward across Central Alabama this afternoon. This trend should
persist into the early evening hours. Looking at the hourly RAP
data, bulk shear is minimal/0-1 and 0-3 SRH is minimal, SBCape is
in the 1000-2000 range, multiple level lapse rates are poor but
winds just off the surface are stronger with some directional
shear. It appears that a storm was rotating over Gardendale with a
potential funnel cloud, but this type of activity will be very few a
far between. Even with very little lightning and no significant
height, some of the isolated storms looked like they had some shelf
clouds, indicative of some wind gusts. No severe will be mentioned
at this time, but a gust of 30 mph in the stronger showers or storms
is possible. Due to the significant moisture in place, a brief
torrential shower is also possible.
A mid level low will inch northward from southern Louisiana and
lose its identity the next 12 hours or so. The atmosphere was
nearly saturated due to the tropical airmass that has invaded
Central Alabama from the Bay of Campeche. Therefore, rain chances
will remain high into Friday.
75
Previous short-term discussion:Today and tonight.
Well the dry weather had to come to an end, as we see a series of
shortwaves begin to move into the region. The shortwave that will
impact the area today is coming out of the Gulf of Mexico near the
LA coastline. This will help to increase the southerly flow across
the area and really pump in the rich gulf moisture during the day.
We will see an increase in shower and storm activity through the
day. Areas most likely to see rain this morning will be along and
south of the US 80/I-85 corridor and then activity will spread
northward quickly through the afternoon.
This wave looks to move out by 10 pm in the east and then we will
await a second shortwave that will develop during the afternoon
along the MS/LA border and slide eastward during the evening hours.
At this time it appears that the best chances will be after midnight
and move into the sw first and then slide northeastward through the
morning. Looks like this may be a fairly widespread rain event with
more or less scattered thunderstorms, so pops are quite high for
an overnight system.
16
.LONG TERM...
Friday through Wednesday.
Fairly widespread showers and thunderstorms should be ongoing
Friday morning as the shortwave trough interacts with tropical
PWATs over 2 inches and a 25-30 kt LLJ. Locally heavy rainfall
will be possible which will have to be monitored with creeks and
streams remaining elevated in the wake of Cindy. Best rain chances
will shift towards the eastern half of the state by midday with
decreased coverage in the west towards afternoon due to
warming/drying aloft caused by subsidence behind the shortwave and
rising mid-level heights. Rain will keep high temperatures down
around 80 in East Alabama with temperatures rebounding in West
Alabama to the upper 80s. Rain chances should largely diminish
Friday night.
For Saturday, 1000-500 mb mean RH values will be lower than
previous days with PWATs being lower but still elevated at around
1.7 inches. The upper-level flow will still be broadly cyclonic
due to a trough centered over the Great Lakes, while a frontal
zone will be located from Oklahoma to the Ohio Valley. Guidance
is hinting that at least outflow and/or an MCV from an MCS may
move in from the northwest Saturday morning. Therefore will
maintain the likely PoPs across much of the area, but did decrease
them very slightly in southeast Alabama closer to a strengthening
mid-level ridge located over the northeast Gulf/FL. Will have to
monitor for at least some strong storms depending on how things
evolve upstream due to steep mid- level lapse rates associated with
an EML and dry air aloft contributing to high DCAPE. Westerly low-
level flow will also result in warming temperatures, with heat index
values approaching 100 in the southern counties.
Sunday into next week the forecast area will mainly be under
northwest flow aloft between troughing over the northeast
US/eastern Canada and subtropical ridging over Texas and the Gulf.
A moist air mass will remain in place. Rain chances and strong
storm possibilities each day will depend on weak shortwaves in
the northwest flow aloft which are typically difficult to
track/time out far in advance.
32/Davis
&&
.AVIATION...
00Z TAF Discussion.
Periods of rain and possible thunder will continue tonight and
tomorrow, affecting all terminals in Central Alabama. There will
likely be a period this evening where coverage decreases and cigs
drop to IFR, before activity return to the area. Expect continued
periods of rain through much of the day tomorrow. Winds will be out
of the southeast tonight and shift to the southwest tomorrow
afternoon.
Rainfall could be heavy at times, reducing vis to IFR and brief
periods of LIFR.
14
&&
.FIRE WEATHER...
Widespread rain chances return today and tomorrow, and remain
elevated through the weekend. There are no fire weather concerns.
&&
.PRELIMINARY POINT TEMPS/POPS...
Gadsden 70 80 72 87 71 / 70 80 40 60 30
Anniston 71 80 72 88 71 / 70 80 40 60 30
Birmingham 70 81 73 88 72 / 70 80 30 60 30
Tuscaloosa 72 85 74 91 73 / 70 80 30 60 30
Calera 70 83 73 88 73 / 60 80 30 60 30
Auburn 70 83 71 87 73 / 60 70 30 50 30
Montgomery 71 86 73 91 73 / 80 60 20 50 30
Troy 70 86 72 90 73 / 70 70 20 50 30
&&
.BMX WATCHES/WARNINGS/ADVISORIES/...
None.
&&
$$
Area Forecast Discussion
National Weather Service Denver/Boulder CO
834 PM MDT Thu Jun 29 2017
.UPDATE...
Issued at 833 PM MDT Thu Jun 29 2017
Convection increasing again as expected as the lift associated
with the shortwave trough arrives. This should keep bands of
showers and storms around the Front Range into the early morning
hours, and on the plains most of the night. Intensity should be
less with cooler temperatures, although there is still enough
moisture to produce some decent updrafts. Cooler air still slated
to arrive overnight. It has looked a little slow coming across
Wyoming, though the pressure rises are now outrunning the
temperature gradient and are into southern Wyoming. At this point,
we expect some enhancement of the north wind behind the trough in
the early morning hours, but the higher dew points and cooler air
behind the trough will lag a bit behind. This should be get here
near or maybe a little after sunrise. This leaves the low cloud
and drizzle forecast in some doubt if it hasn`t saturated yet by
sunrise. At this point it still looks like a pretty good chance of
at least the low clouds and some chance of drizzle or light
showers, so I will leave this alone for now. Only minor changes to
the forecast details at this time.
&&
.SHORT TERM...(This evening through Friday)
Issued at 338 PM MDT Thu Jun 29 2017
Strong thunderstorm development has occurred on the Palmer Divide
this afternoon with hail up to golf ball size in Lincoln County.
Weaker and more high based thunderstorm activity has been moving
over Larimer and Weld Counties with more gusty winds than rain.
Northern Colorado remains under cyclonic westerly flow aloft with
an embedded short wave trough aloft that will move out of the
mountains later tonight. HRRR model runs have been showing a band
of storms moving out over the urban corridor after 9 PM. These
storms should produce more rainfall than this afternoon`s high
based storms. After that area of storms moves through, moist
upslope flow will continue through tomorrow morning. Stratus and
low clouds are expected to develop along with areas of drizzle,
especially near the foothills. Cooler conditions will prevail
through tomorrow, but soundings show the afternoon airmass will
begin to de-stabilize with CAPE values between 700 and 1300 j/kg.
The NAM shows an upper trough moving over northeast Colorado in
the afternoon as the upper air pattern amplifies over Idaho and
Nevada. A round of thunderstorms may develop early in the
afternoon and then sweep eastward as drier air begins moving in
from the west. Upper level jet dynamics from a departing jet may
also help to organize the afternoon thunderstorm activity. Cooler
temperatures will be the other story of the day with high
temperatures on the plains only in the lower to mid 70s.
.LONG TERM...(Friday night through Thursday)
Issued at 338 PM MDT Thu Jun 29 2017
Upper level high pressure building over the Rocky Mountain Region
will bring dry and warmer weather to north central and northeastern
Colorado over the weekend. There may be just enough moisture to
produce isolated late afternoon and early evening showers and
thunderstorms...mainly over the mountains and Palmer Divide on
Saturday.
On Sunday...a slight increase in mid level moisture may result in a
few more showers and storms across north central and northeastern
Colorado. Inverted V soundings suggest that the storms will be
high based with little rain and gusty winds. However...higher
dewpoints along the eastern border...combined with an upper level
disturbance...may result in a few stronger storms across the far
northeastern zones during the late afternoon and evening hours.
On Monday...models shows a short wave trough and associated cold
front moving across northeastern Colorado. A stable airmass behind
the front should limit precipitation chances across much of the
plains. However...greater instability across far eastern sections of
the state...combined with lift from the shortwave may result in a
better chance for storms in those areas.
A large upper level ridge of high pressure is forecasted to rebuild
over the Rocky Mountain Region from Tuesday through Thursday...which
should bring mostly dry weather along with warmer temperatures
temperatures to all of north central and northeastern Colorado.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 833 PM MDT Thu Jun 29 2017
Another round of showers and thunderstorms will move over the
Denver area through about 09z. Conditions will still be mainly
VFR, though some lower ceilings down to around 5000 ft AGL are
possible. Lower clouds are likely to form early Friday morning,
with areas of MVFR ceilings between 11z and 17z. Localized IFR
ceilings are possible for a couple of hours. Ceilings will
gradually lift during the day Friday, though instrument approaches
to KDEN may be needed into the afternoon. Scattered showers and
storms are expected again Friday afternoon with temporarily
lowered ceilings and wind gusts to 30 knots possible at times.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
UPDATE...Gimmestad
SHORT TERM...Dankers
LONG TERM...Kalina
AVIATION...Gimmestad
Area Forecast Discussion
National Weather Service Columbia SC
722 PM EDT Thu Jun 29 2017
.SYNOPSIS...
High pressure near the Mid Atlantic coast will move further
into the western Atlantic tonight. Increasing moisture from the
Gulf will bring mainly afternoon and evening showers and
thunderstorms Friday into the weekend. Scattered afternoon and
evening convection will persist next week as Bermuda high
pressure off the coast brings typical summer weather to the
region.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
As surface ridge shifts offshore....moisture has slowly
increased across the area with precipitable water ranging from
around 2 inches in the CSRA to 1.5 inches in the Pee Dee.
Moisture will continue to increase overnight ahead of short wave
trough. Instability remains weak across the region and
convection has been limited northeast of the CSRA. the latest
hrrr suggested convection will remain limited through the early
evening.
The short wave trough over southwest Ga at 23z will move over
the region tonight. The strongest moisture flux convergence and
isentropic lift appears to be strongest to the west of the area
through much of the overnight. the latest HRRR guidance suggest
convection will move across the region overnight but weaken due
to limited instability and forcing.
So will continue to carry high chance pops in the CSRA this
evening with a gradient to lower pops northward. Cannot drop
pops later tonight with upper trough approaching and deep
moisture over the region so will hold on to some mention of rain
throughout the night. Weak instability and shear minimize the
threat of severe weather.
Widespread stratus is expected to develop late tonight and blanket
the forecast area which should have some impact on overnight lows.
Expect min temps to be in the upper 60s to lower 70s across the
area.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/...
Disorganized mid level low will continuing pushing moisture into
the forecast area from the Gulf Coast...however dynamics in the
mid and upper levels will remain weak. Pwat values Friday will
be 2.1 to 2.2 inches with moderate instability and afternoon
high temperatures in the lower to mid 80s. Isentropic ascent
will also increase over the area resulting in increasing chances
of showers and thunderstorms during the morning hours with
likely showers and thunderstorms through the afternoon. Moisture
will remain over the region Friday night with chance pops
diminishing toward daybreak Saturday. Dynamics will remain weak
on Saturday...however with a bit more heating pushing
temperatures around 90 expect another round of diurnal
convection. Convection will dissipate Saturday night as the
moisture begins sliding away from the region and drier air moves
in.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
Models are in good agreement through early next week with some
differences from mid week onward. Weak surface boundary will
linger near the region Sunday through Tuesday with southeasterly
winds pushing moisture back into the region Wednesday and
Thursday. Upper level ridge will build over the eastern US over
the weekend with temperatures moving back into the mid 90s
through the middle of the week. With moderate moisture and warm
temperatures expect slight chance to low chances of convection
through the long term. Temperatures will be near to slightly
above normal.
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
Surface high pressure center and driest air east of the
terminals. A SE low level flow, and an upper shortwave
approaching from the SW, has led to an increase in atmospheric
moisture over the central and western forecast area (FA). Most
recent NUCAPS soundings and SPC mesoanalysis indicating
generally weak instability across the central Midlands, but
moderate instabilities along with precipitable water (PW) values
near 2 inches or higher, generally from the Savannah river
westward. Radar mosaic indicating weakening band of showers
near the Savannah river which appear to be struggling to hold
together as it encounters drier air. More substantial shower
and thunderstorm activity is still to our west over GA. Latest
high resolution models indicate this activity will gradually
weaken as it shifts ENE into our FA later tonight with the
shortwave. Will handle the activity later tonight with tempo
SHRA.
Outside of precipitation and associated restrictions, continued low
level moistening and precipitation may present a threat for
lowering CIGs tonight into early Friday morning. Latest guidance
indicating MVFR to IFR CIGS late tonight. A gradual return to
VFR is anticipated Friday morning to midday. A very moist
atmosphere in place Friday, along with diurnal heating, is
expected to lead to scattered mainly late afternoon and evening
thunderstorms.
EXTENDED AVIATION OUTLOOK...Late night/morning stratus/fog, along
with scattered mainly afternoon/evening thunderstorms expected.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
GA...None.
SC...None.
&&
$$
Area Forecast Discussion
National Weather Service Charleston SC
1042 PM EDT Thu Jun 29 2017
.SYNOPSIS...
High pressure to the north will extend across the area tonight and Friday.
A surface trough will develop inland on Friday and prevail through the
weekend. Atlantic high pressure will then build in for the early to
middle part of next week.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
As of 1035 PM: A band of weakening showers/rain was over SE GA,
slowly swinging to the NE. Latest run of the HRRR indicated that
the current activity will continue to weaken through midnight.
Activity may increase slightly late tonight as forcing from a
mid level S/W passes over the forecast area. I will keep PoPs
going through the night, but will attempt some detail to the
timing and placement. Otherwise, the forecast will feature
mostly cloudy to cloudy conditions and light SSE winds.
As of 955 PM: An area of light to moderate rain was lifting
north across SE GA, a few patches of rain was over the marine
zones. I will update the forecast to adjust PoP placement and
timing. The mention of TSRA could be lower, but I will continue
to use SCHC.
As of 740 PM: Latest SPC mesoscale analysis indicated little to
no normalized CAPE across the forecast area. KCLX indicates that
deep convection has generally ceased across the CWA, isolated
showers were over the Altamaha River Valley. I will adjust PoPs
lower, primarily north of the Edisto Basin.
Previous Discussion:
Tonight: A short wave ridge will lifts NE, allowing for a short
wave trough in SW GA and the FL panhandle to arrive during the
late evening and overhead within the SW flow aloft. Simultaneously
at the surface we find high pressure north of Bermuda that
slides further east, but expands back to the W-SW across much of
the forecast area. During this transition there could be the
formation of a subtle inverted trough just off the SE coast, but
otherwise the general synoptic flow will be SE veering to S
late. This will continue to advect deeper moisture into the
region, with PWat`s that are already 2" or greater south of the
Savannah River to encompass the entire CWFA before 12Z Friday.
While we will lose much of the diurnal convection by sunset, our
attention then shifts to two locations during the night. The
first will be a cluster of convection that is found in S-SW GA
early this evening. This arrives in combination with the short
wave aloft around 10 pm near the Altamaha River basin as it
lifts NE, reaching near the Savannah River around 12-1 am and
then into SC thereafter. It is during the post midnight period
where low level convergence from off the Atlantic, plus a boost
from isentropic ascent leads to marine induced convection merges
with the convection coming in from the SW. Since there is no
consensus with the models we prefer to show nothing more than
scattered PoP`s during the night time hours. However, it is
likely that higher PoP`s will be required once trends become
better defined, especially if the cluster of storms holds
together as it approaches.
Plenty of cloud cover will prevail, with the formation of late
night stratus/stratocumulus. This could result in some reduction
in surface visibilities, but condensation pressure are not low
enough to add fog to the forecast.
The extensive clouds plus the warm SE-S flow only allows for min
temps in the lower and middle 70s.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/...
A shortwave aloft will exit the region Friday before essentially
flat ridging fills in for the rest of the weekend. Broad Atlantic
high pressure, with a ridge axis extending just south of the area,
will remain in control at the surface through the period. Highest
PWATs (over 2 inches) will be in place through the day Friday as
efficient moisture transport continues in southerly low level flow
and proximity to shortwave aloft keeps modest dynamically-driven
instability in place. Have maintained above climo POPs through the
day Friday, especially north of the I-16. Saturday and Sunday look
like typical summertime airmass days, with sufficient moisture and
instability in place to support afternoon thunderstorms initiating
mainly along the sea breeze and outflow boundaries, with storm
coverage looking a bit less Sunday compared to Saturday owing to
increasing upper level subsidence and a more westerly component to
the synoptic low level flow. Storm type should be mainly pulse, with
overall severe threat is low owing mainly to unimpressive
instability.
Temps will be on the increase through the period owing to the
afore mentioned increasing subsidence and backing low level
flow.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
High pressure will prevail in the Atlantic while a surface
trough persists inland. Southerly flow around the high will keep
plenty of moisture advecting into the Southeast during this
time period. The result will be the typical summertime
shower/thunderstorm pattern.
&&
.AVIATION /03Z FRIDAY THROUGH TUESDAY/...
VFR conditions should prevail across the terminals through the
0Z period. However, it appears that VCSH will be possible near
KSAV this evening and overnight. Both the KCHS and KSAV TAFs
will feature PROB30 between 20z-24z Friday for TSRA with brief
restrictions.
Extended Aviation Outlook: Brief flight restrictions are possible
in afternoon showers/thunderstorms at both terminals into early
next week.
&&
.MARINE...
Tonight: A 10125 mb high to the north of Bermuda slides further
east and strengthens 1-2 mb by morning. Its associated ridge
axis extends W-SW across the local waters and into a large part
of the SE and Gulf of Mexico. While there could be the formation
of a weak inverted trough late over or near the area, the
synoptic flow that starts out from the E at or below 15 kt veers
around to the SE at or below 10 kt. Seas will average 2-3 ft
throughout. Isolated convection this evening will increase into
at least the scattered range overnight.
Friday through Tuesday: Mainly light to moderate west to
southwest breeze will persist through the period as the marine
areas remain on the northern periphery of a ridge axis. Waves
mainly 2-3 feet in small background swell and minor local
windswell, through occasional 4 ft waves are possible for the
offshore Georgia waters.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...None.
SC...None.
MARINE...None.
&&
$$
NEAR TERM...NED
SHORT TERM...
LONG TERM...
AVIATION...NED
MARINE...
Area Forecast Discussion
National Weather Service State College PA
1151 PM EDT Thu Jun 29 2017
.SYNOPSIS...
High pressure off the eastern seaboard will set up a warmer and
more humid airflow for the next several days. A cold front on
Saturday will bring a brief break in the humidity for the second
half of the weekend into Monday.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
Deep layer moisture continues to increase over central and
western PA this evening...focused along the OH/PA border along
the eastern periphery of 850 mb 35-40kt LLJ. Showers and isold
thunder have blossomed over the last few hours over Northwest
PA, and isold activity has now spread into my Northern
Mountains. Sct pops will hold for most overnight, with highest
POPs over the Northwest mountains where forcing is strongest.
Other than isolated to scattered showers/storm, mainly west and
north, it will be a warm- muggy overnight, a break from the
comfortable sleeping weather we have had for the last several
nights.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/...
Weak westerly flow on Friday making for summer type weather for
central PA with hazy and warm conditions. Pops in forecast for
more afternoon convection mainly for the elevated heat sources
as cap will be tough to break.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
Looking at more typical summer weather than we have seen so far
this season. Temperatures will be close to normal for the period
and dewpoints higher than what we have seen this season for the
most part.
The main change was to edge POPS a tad higher on Saturday and
take out showers and storms for Sunday, as models move the
cold front a little faster now.
Left Monday and the first part of the fourth of July dry.
For later Tuesday into Thursday, did adjust superblend POPS
some to fit with others and keep as low as possible. EC has
hinted on some runs that it may be mainly dry. Perhaps the
highest chc of rain will be across the far west on Thursday
for a brief time, hinted at by some of the guidance.
Overall, the cold front will be weak, given the time of
year and the front will not be very far to the south.
Still some variation again today by day 10, GFS and EC
show different solutions, do we see a flat ridge or another
large scale trough. Still a long ways out.
&&
.AVIATION /04Z FRIDAY THROUGH TUESDAY/...
A weakening batch of shower and thunderstorms will push eastward
across the I-80 corridor during the pre-dawn hours, potentially
affecting KUNV or KIPT. Based on 04Z radar trends and HRRR
output, believe there`s about a 50 pct chance for a brief
visibility reduction at KUNV/KIPT between 05Z-09Z. Elsewhere, a
moist southwest flow ascending the high terrain of northwest Pa
could result in tempo MVFR cigs at KBFD through Friday morning.
Model soundings indicate there will be enough diurnal heating to
support cigs rising to VFR at KBFD by afternoon. Despite
predominately VFR flying Friday, scattered showers and tstorms
will affect the entire region Friday afternoon, potentially
resulting in a brief reduction in some locations.
.OUTLOOK...
Sat...AM low cigs poss KBFD. Patchy AM fog poss elsewhere. Brief
PM tsra impacts possible.
Sun...Early AM low cigs possible BFD/JST.
Mon-Tue...No sig wx expected.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SYNOPSIS...Ross/Martin
NEAR TERM...Ross/DeVoir
SHORT TERM...Ross
LONG TERM...Martin
AVIATION...Fitzgerald
Area Forecast Discussion
National Weather Service Dodge City KS
940 PM CDT Thu Jun 29 2017
...UPDATE TO SYNOPSIS...
.SYNOPSIS...
Issued at 939 PM CDT Thu Jun 29 2017
WV imagery indicates a westerly flow aloft prevailing across the
Western High Plains. Near the surface, a near stationary frontal
boundary stretches from the Oklahoma Panhandle northeast across
central Kansas.
&&
.SHORT TERM...(This evening through Friday)
Issued at 208 PM CDT Thu Jun 29 2017
Convective allowing models are fairly aggressive with respect to
upscale thunderstorm growth across western into south central Kansas
this evening. The old cold front has already begun to wash out with
models shoeing more broad easterly surface winds heading into
tonight. As earlier concerns of initial development across the far
southeast have waned, models such as the HRRR have become more
aggressive with the upscale growth into a qlcs wind event well into
central Kansas before midnight. We`ve increased pops to account
for these latest model runs, as well as adjusted overnight lows
for early Friday morning downward. Large hail up to 2 inches may
be the primary threat in the western counties while a wind threat
and heavy rain threat may be more likely with time this evening
into central Kansas counties.
Friday the area will be under the influence of weak northeasterly
surface flow, as a a midlevel shortwave move across the KS/NE line by
the afternoon. This should produce scattered showers and
thunderstorms through the afternoon given the average MUCAPES
around 500 j/KG.
.LONG TERM...(Friday night through Thursday)
Issued at 208 PM CDT Thu Jun 29 2017
The front and major instability/CAPE axis moves farther southeast
into the southern Plains by Saturday. Any storm threats by Saturday
might be in the extreme west it at all. However, the entire southern
High Plains region maintains relatively high dew points, with richer
moisture not being scoured out. The GFS already has a trough across
the Rockies by Sunday with vorticity advection into Kansas by
Sunday night.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 603 PM CDT Thu Jun 29 2017
Short term models earlier this afternoon have been in good
agreement with bringing a cluster of strong to severe
thunderstorms across western Kansas early tonight. Strong winds
and heavy rainfall appear to be the main hazards. Timing so fair
has also been in decent agreement between the last few runs so
will follow the latest trend and introduce strong winds in excess
of 45 knots and at least IFR visibilities and ceilings with these
storms. Timing and track favors the Garden City terminal between
01z and 03z Friday and the Dodge City, Hays and possibly even
Liberal terminals between 02z and 04z Friday. Once these storms
pass the prevailing winds will become north northeast at 10 to 15
knots through the remainder of the night. Model soundings suggest
the potential for some MVFR stratus being possible between late
tonight, especially between 09z and 15z Friday.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 62 83 60 87 / 50 20 10 0
GCK 63 82 58 88 / 50 10 10 10
EHA 62 82 59 86 / 30 10 20 10
LBL 64 84 60 88 / 30 10 10 10
HYS 63 81 59 88 / 40 20 10 0
P28 69 86 63 89 / 70 30 20 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...JJohnson
SHORT TERM...Russell
LONG TERM...Russell
AVIATION...Burgert
Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
1149 PM EDT Thu Jun 29 2017
.AVIATION...
The passage of a mid level short wave will advance across Se Mi
during the early morning hours, providing showers and few embedded
thunderstorms. The chances will be much greater across the metro
Detroit terminals with coverage decreasing to the north toward
Saginaw. Recent model solutions continue to indicate that early
morning rain with some low level moisture advection will support
some MVFR based strato cu, lifting during the course of the morning
and afternoon.
For DTW...Precip should exit to the east by 09Z. Subsidence in the
wake of the short wave will inhibit convective development during
the morning and early afternoon.
//DTW THRESHOLD PROBABILITIES...
* Moderate in ceilings below 5000 ft this morning and afternoon.
* Moderate for thunderstorms tonight. Low Friday morning through
early afternoon, then moderate late Friday.
&&
.PREV DISCUSSION...
Issued at 900 PM EDT Thu Jun 29 2017
UPDATE...
A mid level short wave clearly evident on the recent water vapor
channels over nrn Illinois will lift across Se Mi overnight. The
approach of this wave is already leading to an increase in
convection across SW Lower Mi. Regional satellite data and sfc
observations indicate a low level boundary (remnant outflow from last
nights convection), extending from nrn Ohio across north-central
Indiana. Trends in the radar suggest this boundary will be the focus
for more vigorous convection this evening, fed by instability across
the srn Ohio Valley. Farther north, large scale ascent from the
short wave feature will generate showers with some embedded
thunderstorms. Fairly weak mid level lapse rates over southern Lower
Mi per 00Z DTX sounding and SPC meso analysis should limit the
strength of the convection across the forecast area. The forcing and
recent CAMS support current forecast thinking with higher pops across
the southern half of the forecast area. Given recent trends, an
update will be issued simply to make an upward adjustment to pops
along/south of an Ann Arbor to Detroit line. Timing of the rainfall
looks to be mainly between 03Z and 09Z (11 PM and 5 AM).
PREV DISCUSSION...
Issued at 350 PM EDT Thu Jun 29 2017
DISCUSSION...
Potentially active forecast over the next couple days as a longwave
trough over the region has several features of interest, both at the
surface and mid levels, track through it. Convective complexes
upstream riding along the main instability and theta e gradient
draped across southern MI and northern IL/IN/OH will complicate the
matter by adding clouds making diurnal instability harder to predict
and using up some of the existing instability. Overall chances for
thunderstorms exist this evening through Saturday before drier
weather returns.
This Evening and Tonight: First chance at showers and thunderstorms
will come during the overnight period as an upstream convective wave
works E/NE along the aforementioned theta e gradient. Best chances
will come after 03Z as the wave enters the area, although good
moisture depth and several smaller scale outflow boundaries and
differential heating boundaries may spark a few showers or storms
before that. Hires models have been pretty consistent with the
feature itself but do constantly adjust timing. Thus grids have been
adjusted to account for timing issues, mainly speeding up the MCS.
Looks like the backside of the complex will exit east of SE MI
around 10-12Z. Models are not too impressive with 850mb low level
jet development tonight, which should keep stronger storms more
isolated. Strong winds and heavy rainfall will be the primary
concerns. Current cloud cover, some owning to previous convective
debris from last night, has kept temps and winds in check for the
most part, though any small pocket of clearing typically results in
a quick pop of stronger wind and a temperature spike of a degree or
2. Gusts will diminish some tonight but winds overall will remain
elevated, generally above 10 knots.
Friday: Much of Friday`s forecast is dependent upon how fast the
area can recover from overnight convection and lingering cloud
debris. With a general lack of upper level flow across the country,
the current low over western Ontario will move very little over the
next 24 hours, while the next wave rotating through the trough lifts
up along the cold front draped over western lower MI. Timing of this
wave and semblance of a warm front lifting north will be in the
early afternoon, meaning the area will likely have about 6-8 hours
of recovery and heating after the morning wave. RAP CAPE values
increase to around 1500 J/kg, mostly elevated but soundings do show
the cap trying to break up allowing convection to become surface
based. Bulk shear values will average 35 knots as well. That said,
there remains a Slight Risk of severe weather Friday accounting for
this afternoon wave. PWATs consistently around 1.75 inches will also
keep heavy rainfall a good possibility. Models seem to target
locations between M59 and I69 at the moment for the highest QPF.
Friday Night and Saturday: Trailing deformation axis will swing
through overnight with the main longwave trough axis holding off til
Saturday evening. This said, chances of showers and thunderstorms
will linger through most of the overnight hours and through Saturday
before drier air is brought back into the region.
The Great Lakes will remain under a weak upper-level trough Sunday
into early Monday which will bring the slight chance to see a pop-up
shower or thunderstorm during this time. Additional rain chances
will be possible throughout Tuesday as a weak warm front pushes
across Southern Michigan, however, with ridging building in aloft
from the west and surface high pressure in place across Michigan by
Tuesday morning, conditions will not be favorable for precipitation.
PoP values will remain sub-30 throughout the early half of next
week, with the exception of late Sunday into early Monday, as a weak
cold front brings slightly better chances to see rain.
Otherwise, major divergence is seen across the long-range models
regarding precipitation chances for the late extended period. The
GFS run picks up on a low pressure system that moves from Iowa into
the Ohio Valley Thursday into Friday, bringing rain chances to the
region. The ECMWF run is trying to pick up on this feature, but the
low pressure is not well-developed and the brunt of precipitation
stays south of Michigan throughout Thursday. Additional convergence
between model runs will be needed to increase confidence regarding
precipitation timing and extent. Otherwise, seasonal temperatures in
the lower 80s for a daytime high are expected through next week, as
surface high pressure acts to keep winds and winds gust calm to
light.
MARINE...
Low pressure over central Lake Superior will move into northern
Ontario tonight and maintain moderate southerly wind over marine
areas. Small craft advisories remain in effect and are expected to
expire on schedule this evening. Marine wind conditions will then
remain favorable through the holiday weekend in a diffuse surface
pressure pattern while showers and thunderstorms remain active. Weak
high pressure arriving by Sunday will provide the best chance for a
period of dry weather into Sunday night.
HYDROLOGY...
The next round of thunderstorms is expected to continue organizing
over IA/MO/IL into northern IN during the late afternoon and then
move toward SE Michigan during late evening through the overnight
hours. Higher concentration of activity and potential for heavier
rainfall will be generally south of the I-69 corridor, with the
greatest potential closer to the Ohio border. Average rainfall
amounts up to a half inch are anticipated, but localized higher
totals in excess of an inch are possible where clusters of storms
are able to develop through mid Friday morning.
After a break during late morning and early afternoon, the active
period for showers and thunderstorms will continue into Friday
night. The potential for flooding will be dependent on the
cumulative rainfall totals at any one location during this active
period which will have wide variability across southeast Michigan.
It does appear like coverage will be greater along and south of the
I-69 corridor Friday into Friday night as well and this is where a
corresponding rise of area rivers and streams, as well as minor
flooding, will be possible. Central Lower Michigan will remain most
susceptible as the area continues to recover from recent flooding
but coverage is expected to be lower there.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
Lake Huron...NONE.
Lake St Clair...NONE.
Michigan waters of Lake Erie...NONE.
&&
$$
AVIATION.....SC
UPDATE.......SC
DISCUSSION...DRK/AM
MARINE.......BT
HYDROLOGY....BT
You can obtain your latest National Weather Service forecasts online
at www.weather.gov/detroit.
Area Forecast Discussion
National Weather Service Grand Forks ND
934 PM CDT Thu Jun 29 2017
.UPDATE...
Issued at 931 PM CDT Thu Jun 29 2017
Most of the shower and thunderstorm activity now across the
southeast half of the fa with minimal convection farther north and
west. There is another band of convection over western and central
ND however without a low level jet not sure how this will hold
together. Oriented chance/slght chc pops accordingly. No other
changes needed.
UPDATE Issued at 628 PM CDT Thu Jun 29 2017
Scattered thunderstorms continue to be dispersed across all but
the southeast quarter of the forecast area. With lack of shear and
only 10-15kt steering some of the heavier storms may put out 1-2
inch rainfall with locally higher amounts. With spotty nature of
storms did trim back on pops to chc/sct ranges. No other changes.
&&
.SHORT TERM...(This evening through Friday)
Issued at 300 PM CDT Thu Jun 29 2017
Main challenge for short term forecast will be general TSRA this
aftn...which is just starting west of the valley. In general short
term models have been poor indicating where TS would POP this aftn
until the first storms started to form, when the HRRR began
getting a better handle on it. SPC analysis shows MUCAPE values in
the 1000 to 1200 J/KG range over the valley...where storms across
Nelson county are initiating around 800 J/KG region. There is only
about 25 kts bulk shear over the region and this will not
increase. Expectation will be for pulsey storms with limited svr
potential, but slow movers could result in heavy rain vcnty of the
strongest storms. Upper/mid level forcing depicted by H500-H700
Q-vector convergence shows axis over the valley at 00Z...and
pretty much clear of the CWA by 06Z. Expect any remaining
convection at midnight to quickly deteriorate aft midnight, ending
activity by 09Z. For tomorrow, a repeat of today with Q-vector
convergence moving across mainly the northern tier of zones mid
day, and increasing across NW Minnesota in the late aftn. Expect
any morning convection to be mainly across the north and north
east and may spread south along our eastern zones in the aftn
hours. This is well depicted by most models QPF estimates with the
highest rainfall amounts along the intl border and cooler temps in
eastern zones as shower/TS activity increases by mid-aftn. Once
again little shear to work with tomorrow aftn and expect main
threat to be slow moving storms capable of producing small hail
and heavier rain shower due to storm motion.
.LONG TERM...(Friday night through Thursday)
Issued at 300 PM CDT Thu Jun 29 2017
High pressure will be poised to head south and east out of southern
Saskatchewan early in the weekend. This high will head down toward
the international border while another surface high takes up re
silence over the Central Plains. A weak boundary may set up
between these two, at this point though not much in the way of any
pcpn is expected. The most likely area for anything would be far
NW MN. On Sun the Canadian high will become the more prominent
feature, treating the forecast area to sun, light winds and temps
that will still be a few degrees below early July averages.
Mon-Thu...the early to midweek period will be characterized by a
building ridge to the lee of the Rockies moving over the Northern
Plains. Look for a reasonably dry period during this time with an
increase in temperatures. Most ensemble guidance indicates a
strong potential for warmer temperatures (above normal values).
The ECMWF is stronger than the GFS with this ridging, and thus
keep all thunder activity north of the region in true ridge rider
fashion. There is still lots of uncertainty with the strength of
this ridging, which will determine thunderstorm chances (and
severe potential).
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 628 PM CDT Thu Jun 29 2017
Spotty slow moving storms at this time not impacting any TAF sites
so maintained vcts/vcsh through the evening and will monitor. Cigs
remain VFR however guidance does bring in some mvfr cigs toward
morning.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...None.
MN...None.
&&
$$
UPDATE...Voelker
SHORT TERM...Speicher
LONG TERM...WJB
AVIATION...Voelker
Area Forecast Discussion
National Weather Service GRAND JUNCTION CO
816 PM MDT Thu Jun 29 2017
.UPDATE...
Issued at 814 PM MDT Thu Jun 29 2017
As expected, winds have died down considerably as the atmosphere
begins to decouple. Since Red Flag conditions are not being met
in most areas, it was allowed to expire. Current grids looking
good so no changes to going forecast.
&&
.SHORT TERM...(Tonight through Friday night)
Issued at 334 PM MDT Thu Jun 29 2017
Cool front boundary appears as though it has stalled across the
central corridor with shower activity across the northern
mountains and sprinkles over the northern valleys this afternoon.
With a split 80kt jet overhead to the north and south of this
boundary, this should continue to allow for mixing during peak
afternoon heating for winds and relative humidity meeting critical
fire weather thresholds once again. A Red Flag Warning remains in
place through this evening. See Fire Weather discussion below for
more details. Not expecting much precipitation out of these
showers as the atmosphere remains so dry, but gusty outflow winds
and lightning are the primary concerns. The back edge of this
upper level trough responsible for the Red Flag conditions the
last few days will finally exit to the east and push the cool
front across the rest of the forecast area this evening into the
overnight. Some showers may linger over the divide by Friday
morning as an area of channelized vorticity on the back edge of
the trough pushes through. High pressure will rebuild over the
Great Basin and slide over the region by Friday afternoon with
much lighter gradient winds as we lose the influence of the upper
level jet. This will result in a cooler morning and afternoon on
Friday with lighter winds and a reprieve from the widespread
critical fire weather conditions. There may be some occasional
breezes during the afternoon with localized critical fire weather
conditions, but winds should largely stay below critical
thresholds with mostly sunny skies.
Regarding the smoke from local and distant wildfires, the latest
HRRR shows the smoke from the Brian Head wildfire in SW Utah
continuing to transport smoke across SE Utah into SW Colorado this
evening and overnight into Friday morning. Introduced areas of
smoke back into the forecast again for these areas through Friday
morning. Smoke from the Lightner Creek wildfire northwest of
Durango is also seen in the HRRR model and is expected to shift
southward as the cool front moves southward overnight tonight.
Smoke is expected to settle into the Animas and San Juan River
Basins affecting the southern valleys of Durango and Pagosa
Springs through Friday morning and possibly the afternoon as the
gradient lessens and winds decouple causing the smoke to become
trapped in valley inversions. Highlighted this area for greater
smoke coverage in the forecast through Friday afternoon.
.LONG TERM...(Saturday through Thursday)
Issued at 334 PM MDT Thu Jun 29 2017
A ridge of high pressure will remain overhead Saturday but try to
break down as an upper level trough moves into the Great Basin.
Southwest flow is expected to increase by Sunday afternoon ahead
of this trough and track over the region Sunday evening into
Monday morning. The atmosphere remains dry with Precipitable Water
(PW) values mostly less than 0.3 inches, but some pockets of 0.5
inches show up which is enough to generate some isolated shower
and thunderstorm activity. Expect mostly virga and gusty outflow
winds with these showers. Regarding the gradient winds, H7 and H5
winds only increase to 20 kts with a weak upper level jet so not
expecting widespread critical fire weather conditions at this
time.
High pressure builds in firmly by Tuesday and remains in place
through Thursday with some moisture trying to sneak in under the
ridge by the latter half of the week. This will lead to mainly hot
and dry conditions with isolated thunderstorms possible over the
higher terrain each afternoon, but more likely towards the end of
the week as the profile saturates a bit more. H7 temps show a good
warming trend towards 20 degrees C by Wednesday and Thursday,
which translates to triple digit heat returning once again for
the Grand Valley and valleys of southeast Utah.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 518 PM MDT Thu Jun 29 2017
Gusty winds will continue for the next few hours before dying down
as the atmosphere decouples. Some convection that fired this
afternoon will also die down at this time. No concerns for any TAF
sites. Partly cloudy skies are expected tomorrow with a few gusty
winds in the afternoon though they should be less widespread and
also considerably weaker.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...None.
UT...None.
&&
$$
UPDATE...TGR
SHORT TERM...MDA
LONG TERM...MDA
AVIATION...TGR
Area Forecast Discussion
National Weather Service Goodland KS
600 PM MDT Thu Jun 29 2017
.SHORT TERM...(This evening through Friday)
Issued at 300 PM MDT Thu Jun 29 2017
An upper level disturbance currently moving southeast over the
Colorado front range is forecast to initiate showers and
thunderstorms generally along and south of the interstate and west
of highway 27 around 00z. Upper level jet divergence signature
suggests a cluster of thunderstorms which is also suggested by
hrrr model qpf. Severe weather is likely. This cluster of storms
is expected to move east and southeast across the area during the
evening and generally out of the area by midnight. Should have a
lull in activity during the early morning hours of Friday before
another disturbance and jet support moves in from the northwest
supporting another chance of showers/thunderstorms by sunrise. Mid
level moisture rather lacking during the afternoon so only slight
chance pops for now.
Low temperatures in the low 50s west to low 60s east. High
temperatures Friday in the low to mid 70s in far eastern Colorado,
mid 70s to low 80s elsewhere.
.LONG TERM...(Friday night through Thursday)
Issued at 137 PM MDT Thu Jun 29 2017
Flow aloft becomes northwesterly Friday night as a ridge builds over
the southwestern CONUS. High pressure moves east onto the region,
resulting in increased temperatures on Saturday as well as dry
weather. Models hint at a quick shot at precipitation overnight on
Saturday for the southern portion of the forecast area.
The next shortwave set to impact the area arrives on Sunday,
generating shower and thunderstorm chances in the afternoon and
evening. The shortwave strengthens a lee trough, with southerly
winds drawing moisture north. The increasing moisture along with
decent shear and instability should be enough for a few severe
thunderstorms. Will continue to monitor. Precipitation exits the
region overnight.
A somewhat active pattern continues into next week with the upper
ridge expanding northeast and some moisture filtering northward
underneath. A similar setup to Sunday will develop on Monday.
However, in addition to this, a disturbance traverses the Rockies
and advances across the area. This generates shower and thunderstorm
chances again in the afternoon and evening hours. Dry conditions are
anticipated on Tuesday as the system moves east.
Wednesday and Thursday: The upper ridge over the southwestern
portion of the country amplifies, expanding north and east, and flow
aloft remains from the north northwest during this period on the
eastern side of the high pressure. Guidance differs in the strength
and position of the ridge. Kept slight to low chance PoPs each
afternoon and evening as disturbances work their way through the
flow.
High temperatures during the period mainly range within the mid 80s
to mid 90s across the region. Low temperatures stay in the 50s and
60s.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 530 PM MDT Thu Jun 29 2017
TSRA with MVFR to VFR will start out the GLD TAF with a quick
return to VFR conditions once the discrete cell moves east of the
site after 01Z.
MCK will remain VFR through the TAF period with a few
thunderstorms moving through the vicinity between 02-06Z. Showers
may also move through the area of the MCK site between 14-20Z
during the day on Friday.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...BULLER
LONG TERM...JBH
AVIATION...LOCKHART
Area Forecast Discussion
National Weather Service Wilmington OH
1046 PM EDT Thu Jun 29 2017
.SYNOPSIS...
The threat for showers and thunderstorms will increase Friday
through Saturday as an upper level disturbance moves across the
area. A surface cold front will then push through the area
Saturday night / Sunday morning with drier weather expected
Sunday as high pressure builds in.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
A potent shortwave is currently pushing east this evening into
Illinois with widespread shower and thunderstorm development
occurring out in front. The track of the shortwave will be
towards the northeast with it generally starting to shear out as
it approaches the area. Not surprisingly high res models then
try to weaken the convection as it approaches the area. This
appears likely due to the weakening upper level disturbance and
waning instability. Looking at RAP forecast ML CAPE though does
show some elevated instability remaining. Due to this have
bumped up PoPs across the north to likely to account for this.
High res models have also been hinting at spotty development out
ahead of the shortwave which appears to be in response top weak
low level convergence (as hinted at by RAP 850/ 700 mb winds).
Friday afternoon showers and thunderstorms will begin to
redevelop as another shortwave ejects out of the Rocky Mountains
and heads east around the base of a strengthening shortwave
trough. Significant disagreement exists here between the NAM
and GFS. The latest GFS is much weaker with the strength of the
upper level jet and has lower instability values. The NAM is
much stronger with the shortwave in amplitude and upper level
jet streak strength. Overall think the NAM is overdone here.
Still though some storms could be strong to severe with SFC to 6
km shear around 30 kts. Due to the above SPC has us in a Day 2
slight risk.
Prev Discussion->
Extensive cu field has developed across the forecast area. A few
isolated showers have developed along and southeast of
Interstate 71. Some additional shower and thunderstorm activity
will be possible through the near term as a weak upper level
disturbance approaches the area. The severe threat appears
minimal, however cannot rule out an isolated damaging wind gust
tonight across the north. Went close to guidance for low
temperatures overnight.
Wind gusts will continue through the early evening hours before
beginning to dissipate for the overnight hours. Although, wind
gusts will subside expect winds to stay up some overnight.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/...
An upper level disturbance will move through the region on
Friday allowing for additional shower and thunderstorm chances.
There is a chance that some of the storms could produce damaging
wind gusts and therefore there is a slight risk and marginal
risk out across the region. Went close to guidance for
temperatures through the short term period. Winds will pick up
for the daytime hours on Friday, however do not expect wind
gusts to be quite as high as today.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
A cold front will push southeast across our area Saturday into
Saturday night. Ahead of this, a better chance for pcpn will exist
across southeast portions of our fa as a short wave lifts northeast
across the upper Ohio Valley. Meanwhile, a lingering chance of
thunderstorms will exist elsewhere across the area Saturday into
Saturday evening until the front moves through. Highs on Saturday
will be in the lower 80s.
High pressure and a drier airmass will build into the area for
Sunday with highs again mostly in the lower 80s. We will then
transition to more of a zonal flow pattern aloft as a weak boundary
pushes down from the north and possibly lays out across our area
through mid week. This will allow for several disturbances aloft to
work east across the region through the remainder of the period.
With a boundary also in place, this will lead to chances of showers
and thunderstorms at times through the later periods of the longer
term forecast. Highs will mostly be in the mid 80s through Thursday.
&&
.AVIATION /02Z FRIDAY THROUGH TUESDAY/...
Gusty southwest winds from this afternoon have slowly started to
decrease as the sun has started to set. A weak differential
heating boundary has formed across our northern zones this
afternoon which has allowed showers and thunderstorms to form.
Friday morning an upper level disturbance will move overhead
with another batch of showers and thunderstorms approaching
from the west. At the same time a band of low level convergence
will move across the region. The high res models show some
showers and thunderstorms developing along the nose of the jet
and pushing northeast. For now have added a VCSH to account for
this, but the placement remains semi- nebulous at this point.
The most likely genesis region appears to be along interstate 71
near KILN.
Friday afternoon showers and thunderstorms will then likely
pop back up. Later Friday afternoon an upper level disturbance
will move across the area helping to better focus development.
Timing on the global models mostly shows the better development
towards later Friday evening. As of now have left vicinity in
the TAFs but this will likely need to be upgraded in future
issuances. Friday morning into afternoon some gusty winds will
be possible but GFS and NAM forecast soundings show gusts in the
15 to 20kt range.
OUTLOOK...Thunderstorms possible at times from Friday into
Saturday night and again Monday through Tuesday.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...None.
KY...None.
IN...None.
&&
$$
SYNOPSIS...Haines/Novak
NEAR TERM...Haines/Novak
SHORT TERM...Novak
LONG TERM...JGL
AVIATION...Haines
Area Forecast Discussion
National Weather Service Lincoln IL
913 PM CDT Thu Jun 29 2017
.UPDATE...
Issued at 912 PM CDT Thu Jun 29 2017
A line of thunderstorms, a few of them strong to briefly severe is
aligned just east of the I-57 corridor through central IL and
moving slowly eastward. With sunset, instability is slowly waning
as the line organizes, with LAPS and RAP analyses showing around
1000 J/KG. SPC has reduced the severe thunderstorm outlook to
marginal risk from the slight risk of earlier today. This feature
should pass into Indiana around 11 p.m. to midnight. The next
feature will be a developing thunderstorm complex over northern
Missouri that 01Z HRRR model indicates should move ESE and affect
areas possibly as far north as Jacksonville, Springfield, to
Charleston/Mattoon from around Midnight to early morning. Will be
sending updates to PoPs to try to better specify these features in
short term forecast.
&&
.SHORT TERM...(This evening through Friday)
ISSUED AT 300 PM CDT Thu Jun 29 2017
An MCV over central MO had convection from central MO and
developing recently into central IL near I-72. Also have a band of
showers spreading east over the IL river valley. CAPES have
increased to 1200-2200k J/KG from I-72 south with 2-3k J/KG over
southern IL near I-64 and pockets over western/sw IN. Have a
lingering cap over central IL though this has been weakening se of
the IL river where more filtered sunshine and heating into the mid
to upper 80s. Dewpoints were higher today, in the mid 60s over IL
river valley and near 70F in southeast IL from Taylorville to
Danville se. 1st wave of scattered convection to spread east over
central IL this afternoon and depart by sunset, with a 2nd wave
spreading east from northern MO into central IL later this evening
and overnight. HRRR model has been quicker and further south with
its convection and 2nd wave gets into southeast IL overnight.
Good chance of showers and thunderstorms redeveloping over CWA
during Friday in unstable airmass. SPC has slight risk of severe
storms through tonight north of I-70 and marginal risk of severe
storms on Friday across CWA. Think areas se of I-55 will have
strongest storms on Friday afternoon thru sunset. Lows overnight
in the lower 70s, with some upper 60s nw of the IL river. Highs
Friday in the mid 80s, except lower 80s nw of the IL river.
.LONG TERM...(Friday night through Thursday)
ISSUED AT 300 PM CDT Thu Jun 29 2017
Highest convection chances shift into southeast IL during Friday
night as frontal boundary pushes through area. Lows Fri night
range from lower 60s nw of IL river to near 70F by Lawrenceville.
The front will be near the Ohio river valley and lingered isolated
convection se IL Sat morning. Highs Sat in the lower 80s over
central IL and mid 80s in southeast IL. Getting less humid during
the day Saturday with wnw flow as dewpoints slip into the upper
50s/lower 60s Sat afternoon in central IL and mid 60s in southeast
IL.
Dry weather expected from Sat afternoon through most of Sunday as
weak high pressure settles in. Lows Sat night in the lower 60s
with some upper 50s north of Peoria. Seasonable highs Sunday in
the mid 80s with dewpoints in the lower 60s. Isolated convection
could affect areas nw of the IL river late Sunday afternoon, then
have chance of showers and thunderstorms along and north of I-72
Sunday night. This due to a disturbance dropping into the Great
Lakes region where a weak upper level trof is located then.
More humid/tropical airmass returns Mon-Thu along with more
unsettled weather pattern and daily chances of
showers/thunderstorms. Best chances on Monday still appear north
of I-70 with just isolated convection se of I-70 Monday
afternoon. Better chances of convection with possible MCS arrive
across area Monday night, and more development of convection
Tue/Tue night with approaching upper level trof. This feature
moves east over IA/MO Tue night and Wed and into IL Wed night and
Thu and will likely bring more chances of showers and
thunderstorms. Seasonable highs in the mid to upper 80s Monday,
low to mid 80s Tue and mid 80s Wed/Thu. Rather humid as well with
dewpoints rising into the upper 60s/lower 70s.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 708 PM CDT Thu Jun 29 2017
Several disturbances may affect central IL TAF sites over the
upcoming 24 hours producing thunderstorm activity. In the short
term, a departing mesoscale convective vortex will continue to
produce a few thunderstorms through evening today, mainly for
eastern TAF sites KBMI-KCMI-KDEC where mention of thunder included
in 00Z TAFs. After approximately 06Z...convection over northern
Missouri will likely push eastward and may affect southern TAF
sites KSPI-KDEC. Finally, a shortwave over NB/IA this evening is
expected to develop significant thunderstorm activity pushing
eastward overnight. This system and an associated frontal boundary
pushing into the region Friday will bring good chances for rain
showers and thunderstorms, although timing of the feature remains
highly uncertain still. Winds generally S-SW under 10 kts
overnight, increasing to 10-15 kts after 12Z, although some
variability in direction associated with shower and thunderstorm
activity.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...37
SHORT TERM...07
LONG TERM...07
AVIATION...37
Area Forecast Discussion
National Weather Service Northern Indiana
731 PM EDT Thu Jun 29 2017
.SYNOPSIS...
Issued at 723 PM EDT Thu Jun 29 2017
Scattered showers and thunderstorms are expected tonight
especially over northwest Indiana and southwest Michigan where
some locally heavy rainfall could occur. Highs this afternoon
will range in the low to mid 80s with increasing humidity. Drier
and pleasant weather is expected this weekend. Highs will be in
the upper 70s to lower 80s.
&&
.SHORT TERM...(This Evening through Friday)
Issued at 210 PM EDT Thu Jun 29 2017
Water vapor imagery and latest RAP analysis depicting weak
disturbance/MCV emanating from previous nocturnal MCS is now moving
into northern MO with decent 50-55kt mid level flow. CAMs seem to be
keying in on this feature for potential convection over our area
late this afternoon thru tonight as it brings convective complex
along the W/SW mean cloud bearing wind. KIWX and surrounding radars
showing initial development underway this afternoon in advance of
this feature. Forecast soundings indicating decent amount of
instability to work with over our area tonight as increasing low
level moisture will have CAPEs around 1500J/kg. Hodograph becomes
linear with time as wind profile becomes more unidirectional
resulting in primary severe threat being damaging winds. Strength of
flow and forcing will be supportive for strong storms and possible
severe with 40-45kt LLJ and effective shear values around 45kts.
Frontal wave located over the central plains this afternoon will
lift E/NE through the period and eventually bring cold front into
the area by Friday afternoon. This will bring potential for another
round of storms...especially over the eastern CWA as timing will
favor diurnal destabilization of airmass ahead of the front with
CAPEs around 2000J/kg. Similar severe threat as wind profile remains
unidirectional.
&&
.LONG TERM...(Friday Night through Thursday)
Issued at 210 PM EDT Thu Jun 29 2017
Lingering chances for precip primarily in the eastern CWA Friday
night into Saturday morning as cold front slowly pushes through.
Remainder of the weekend looking rather pleasant as weak surface
ridging builds into the region providing dry weather and near normal
temps. Next week will have a series of weak short waves moving
through the northern stream flow across southern Canada while upper
level ridging builds over the four corners and along the gulf coast
leaving a stalled surface boundary and baroclinic zone in between.
This boundary will be the main player for our weather and much
uncertainty still remains as to its location and impact. Medium
range models currently show boundary a little further south as they
carve out a trough along the eastern flank of upper ridge over the
mid MS valley pushing surface boundary down into the OH/TN valley.
This would trend our area toward a drier forecast and lower precip
chances. As expected...plenty of spread amongst the ensemble members
so believe it prudent to both keep chance pops going days Mon-Wed
but also not go with anything in likely category until better
consensus is realized. ECMWF then has upper ridge shifting east
toward our area bringing dry and warmer weather by day 7 while GFS
still has boundary in the vicinity resulting in continued precip
chances. Temperatures through the period will be near seasonal norms
with highs in the 80s and lows in the 60s.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday Evening)
Issued at 723 PM EDT Thu Jun 29 2017
Sctd convection south of KFWA and sw of KSBN have prompted either
warnings or sig wx advisories. expect additional activity to
develop and move into northern IN later tonight after 03Z. Went
mainly with VCTS or tempo TSRA for a couple of hours during the
night. Expect MVFR cigs for a portion of Friday morning before
trending toward VFR during the aftn.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SYNOPSIS...Frazier
SHORT TERM...JAL
LONG TERM...JAL
AVIATION...Frazier
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Area Forecast Discussion...UPDATED
National Weather Service North Platte NE
711 PM CDT Thu Jun 29 2017
.UPDATE...
Issued at 710 PM CDT Thu Jun 29 2017
Updated forecast ot drop severe thunderstorm watch.
&&
.SHORT TERM...(This evening through Friday)
Issued at 343 PM CDT Thu Jun 29 2017
A SFC frontal boundary draped across Ncntl Neb near Oneill north to
around Winner SD is expected to be the focus for severe storm
development late this afternoon through early evening. Storm
coverage is expected to be isolated to scattered and quite severe
given the high CAPE and 50 kt 500mb winds aloft. The 15z-18z HRRR
radar product depicted a bow echo producing model generated winds
gusts as high as 95 mph. The forecast storm was east of Holt County
in the Missouri river valley. Some models like the NAM and HRRR EXP
were a bit farther west with storm initiation. The location of the
front around 21z this afternoon will likely dictate the location of
storm development.
There is a chance for storm development off the nrn portions of the
Front range and Laramie range this afternoon which could drift into
Swrn Neb this evening. Not sure if it will make it into Swrn Neb
since this area will be post-frontal.
Otherwise the forecast is dry tonight. The model consensus indicates
a weakly organized area of showers and thunderstorms, currently
affecting the Tetons and Big Horn range, will move into Garden
County Friday morning and affect the Cntl Sandhills throughout the
day. Blended guidance plus bias correction suggested highs in the
70s Friday with mostly cloudy skies. H700mb temperatures fall into
the low single digits celsius. Lows tonight fall into the 50s to
lower 60s using the same guidance blend.
.LONG TERM...(Friday night through Thursday)
Issued at 343 PM CDT Thu Jun 29 2017
The ECM is about 6 hours slower with the convective system forecast
to develop off the Black Hills Sunday afternoon. The model waits
until 06z to carry it into Nrn Neb. The GFS and GEM are faster
igniting storms off the Black Hills around 18z. The GFS model also
suggests storm activity forming on the Cheyenne Divide which moves
through Swrn Neb. The POP forecast is for scattered storm coverage
which is appropriate for a high CAPE capped atmosphere with H700mb
temperatures in the 10-12C range. Note GFS and ECM indicate HP
storm type QPF totals with bulls-eyes of 1-inch+ amounts.
There is a chance that the models are too fast developing storms
Sunday and the better rain chance could be Monday. The forecast
carries a chance POP Monday afternoon for storm development.
No other rain chances are in place; just isolated thunderstorms here
and there. The upper level ridge of high pressure across Old Mexico
will build north toward the Cntl Plains Sunday and present hot
weather Tuesday through Thursday. There is a chance rain cooled air
could enter Nebraska and take the edge off temperatures. This would
be the result of outflow from storms across the Nrn Plains.
The temperature forecast is for upper 80s to mid 90s Sunday and
beyond. This could be conservative given the 12-14C 700mb
temperatures that are forecast by the models.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 639 PM CDT Thu Jun 29 2017
Scattered thunderstorms will move out of the Nebraska Panhandle
into western Nebraska this evening with mainly high based
thunderstoms. North to northwest winds will become light over the
area tonight. and then increase Friday morning. Scattered
rainshowers are possible over western Nebraska on Friday as an
upper level systme moves to the southeast across the area. Visual
flight rules expected.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
UPDATE...Power
SHORT TERM...CDC
LONG TERM...CDC
AVIATION...Power
Area Forecast Discussion
National Weather Service New Orleans LA
959 PM CDT Thu Jun 29 2017
.UPDATE...
The isolated severe weather/tornado risk and flash flood risk
appeared to be winding down late this evening after an active late
afternoon and early evening on the Mississippi Gulf coast. A well
defined mesoscale cyclonic vortex was observed in radar imagery
earlier moving east across the upper Florida parishes and the near
the southwest Mississippi state line, but should no longer have a
significant factor in the forecast. The continue flux of deep
tropical moisture and unseasonably strong low level inflow was
responsible for the flood producing rainfall and rotating mini-
supercells, however the inflow has been gradually weakening during
the late afternoon and evening, and upper level support is also
waning. Have cancelled the Flash Flood Watch and updated the
forecast to lower rain chances overnight into the early morning
hours on Friday. 22/TD
&&
.AVIATION...
Any lingering SHRA/TSRA in the vicinity of KGPT should be
dissipating or moving away from the terminal, however there is
still a slight chance of one or two terminals seeing a brief
SHRA/TSRA overnight. The TAFs will likely not be indicating any
additional TSRA until Friday afternoon when a PROB30 group has
been included. Also, am expecting MVFR conditions (mainly due to
low CIGS) to develop overnight with a chance of IFR at one or two
terminals. Mostly VFR is expected to return by Friday afternoon.
22/TD
&&
.PREV DISCUSSION... /issued 348 PM CDT Thu Jun 29 2017/
SYNOPSIS...
Weak upper low currently over the area, enhancing development of
showers and thunderstorms. A few of these storms have developed
rotation, so worthy of keeping an eye on. In addition,
precipitable water values continue to run 2.25 inches or higher,
so heavy rain remains a threat late this afternoon and this
evening. Temperatures have had a difficult time getting past the
convective temperature in the lower 80s for very long.
SHORT TERM...
Upper low will only slowly shear out over the next 36 to 48 hours
and will have to continue mention of POPs in the 40-60 percent
range tonight and Friday. Organized heavy rain threat should
diminish after the current round of convection diminishes, per the
latest HRRR runs, and currently plan on letting FFA run until
expiration at 03Z. Evening shift can extend part or all of the
watch if radar trends necessitate it. Precipitable water values
are forecast to drop from the current 2.25 inches to about 1.7
inches for Saturday and Sunday, justifying lower rain chances.
Don`t think we will be completely dry all weekend, but any
activity should remain isolated in most areas.
With convective temperatures warming into the upper 80s tomorrow,
this should allow for somewhat warmer temperatures, but don`t see
many, if any, areas reaching 90 tomorrow. However, Saturday and
Sunday are a different matter. Expect lower 90s to be widespread
with the possible exception of immediate coastal areas where sea
breezes may hold temperatures in the upper 80s. Heat index
readings for Saturday and Sunday are likely to be around 100
degrees in many areas. We haven`t had too many oppressive heat
episodes so far this season, so be a little careful out there. 35
LONG TERM...
Weak upper ridging takes hold along the central Gulf Coast for
much of next week, but doesn`t look strong enough to totally shut
off convection. Expect that we will see more of a climatologically
consistent pattern, with isolated to scattered afternoon
convection. Highs will reach the lower 90s in most areas. 35
AVIATION...
Main issue over the next 6 hours will be convection, which is
being accounted for with TEMPO groups in all terminals showing
brief MVFR to IFR conditions. Areal coverage of convection should
diminish after sunset. Beyond 06Z...expect lower clouds to
redevelop, with most terminals going to MVFR conditions. Exception
likely to be MCB, where high end IFR ceilings are possible.
Anticipate redevelopment of scattered convection by late morning,
which will likely be addressed in 00Z TAF forecast package. 35/CAB
MARINE...
With high pressure moving into the area, wind and wave conditions
should remain below headline criteria outside of thunderstorms
through the forecast package. 35
DECISION SUPPORT...
DSS code: Yellow.
Deployed: None.
Activation: None.
Activities: Monitoring rainfall today across the area
Decision Support Services (DSS) Code Legend
Green = No weather impacts that require action.
Blue = Long-fused watch, warning, or advisory in effect or
high visibility event.
Yellow = Heightened impacts with short-fused watch, warning or
advisory issuances; radar support.
Orange = High Impacts; Slight to Moderate risk severe; nearby tropical
events; HazMat or other large episodes.
Red = Full engagement for Moderate risk of severe and/or
direct tropical threats; Events of National Significance.
&&
.PRELIMINARY POINT TEMPS/POPS...
MCB 72 88 74 92 / 40 50 10 20
BTR 74 89 75 92 / 20 50 10 20
ASD 76 89 77 91 / 30 50 10 20
MSY 77 89 77 91 / 20 40 10 20
GPT 77 87 78 89 / 70 50 10 20
PQL 76 87 76 89 / 70 50 10 20
&&
.LIX WATCHES/WARNINGS/ADVISORIES...
LA...None.
GM...None.
MS...None.
GM...None.
&&
$$
Area Forecast Discussion...Updated Aviation
National Weather Service Saint Louis MO
553 PM CDT Thu Jun 29 2017
.SHORT TERM... (Through Late Friday Afternoon)
Issued at 328 PM CDT Thu Jun 29 2017
Convection continues to develop across west central and central MO
and head for the St Louis metro area this afternoon. Some of this
convection was ahead of an MCV and along an outflow boundary from
morning convection. Development should continue into the early
evening hours with daytime heating and instability. Lot of model
differences with location and timing of another possible nocturnal
MCS for late tonight and Friday morning. Will follow the NAM and
experimental HRRR model solutions which bring an MCS southeastward
into northeast and central portions of MO around midnight, then
through the rest of the forecast area late tonight and Friday
morning. Warm and humid conditions can be expected tonight, then
slightly cooler high temperatures are forecast on Friday across
central and southeast MO and southwest IL due to morning cloud cover
and convection. Could not rule out redevelopment of convection
Friday afternoon with the approach of an upper level trough and as
the atmosphere tries to destabilize again, although the effective
boundary may be southeast of much of the forecast area by this time.
GKS
.LONG TERM... (Friday Night through Next Thursday)
Issued at 328 PM CDT Thu Jun 29 2017
Cold front will slowly work through the area and exit the region by
Saturday afternoon then move into southern Missouri bootheel by
Sunday morning. The front will then lift north northward late
Sunday and pushes to just north of the I-70 corridor early Monday
afternoon.
Saturday will likely be dry for most areas with the exception of
area closer to the front. Scattered showers and thunderstorms are
possible along and south of the warm front as it moves north on
Sunday. The front will be located roughly just south of the Missouri
and Iowa line by Tuesday morning then become qausi stationary. A
shortwave is forecast to push through the area Monday night into
Tuesday morning with a chance for scattered to numerous showers and
thunderstorms possible in central Missouri. A chance of scattered
showers and thunderstorms will linger through the 4th of July
holiday into early Wednesday. High pressure will slide into the
region by Wednesday afternoon and provide dry weather for the rest
of the period.
Temperatures are expected to be at or just below climatological
ranges for the duration of the extended forecast period.
Kelly
&&
.AVIATION... (For the 00z TAFs through 00z Friday Evening)
Issued at 530 PM CDT Thu Jun 29 2017
Current convection between COU and UIN may eventually spread into
UIN later this evening, with new convective development across
southeast KS into west central MO likely moving into COU late
tonight, and eventually may move into the St Louis metro area by
early morning. Still a lot of uncertainty as to the timing and
extent of nocturnal convection. MOS guidance fairly consistent
that we will have prevailing MVFR cig heights Friday morning,
otherwise VFR conditions outside of showers/storms. Mainly south-
southwesterly surface winds through the period, although at times
chaotic near thunderstorms and outflow boundaries.
SPECIFICS FOR KSTL: Convective development across southeast KS
into west central MO may move into the St Louis metro area late
tonight and early Friday morning. Still a lot of uncertainty as
to the timing and extent of nocturnal convection. MOS guidance
fairly consistent that we will have prevailing MVFR cig heights
Friday morning, otherwise VFR conditions outside of
showers/storms. Mainly south-southwesterly surface winds through
the period, although at times chaotic near thunderstorms and
outflow boundaries.
GKS
&&
.PRELIMINARY POINT TEMPS/POPS...
Saint Louis 75 87 70 86 / 40 50 40 10
Quincy 68 83 64 83 / 60 50 10 5
Columbia 71 83 65 84 / 50 40 30 5
Jefferson City 72 85 66 85 / 40 30 30 10
Salem 73 84 68 85 / 30 50 50 20
Farmington 70 82 67 84 / 20 50 60 20
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...None.
IL...None.
&&
$$
WFO LSX
Area Forecast Discussion
National Weather Service Memphis TN
630 PM CDT Thu Jun 29 2017
.DISCUSSION... /issued 310 PM CDT Thu Jun 29 2017/
Skies are partly cloudy across the forecast area this afternoon
with temperatures mainly in the 80s. Scattered showers continue to
move north across mainly the southern half of the forecast area
but seems to die off as it reaches portions of west Tennessee and
east Arkansas.
More showers and some thunderstorms are possible tonight as
moisture continues to stream north from the Gulf of Mexico with
the best chance of rain over North Mississippi. Temperatures will
remain seasonably warm with lows Friday morning in the lower 70s.
An upper level disturbance will move across the region on Friday
which will help trigger some additional showers and thunderstorms.
Temperatures will remain near normal levels with highs in the mid
80s to around 90 degrees.
By Friday night, a cold front will be moving into southern
Missouri. This will help produce a better chance of thunderstorms
especially over the northern half of the forecast area. By
Saturday, the cold front will be inching closer to the region so
there will be a better chance of thunderstorms over southern
sections of the forecast area. There is a marginal risk of severe
weather on Saturday with damaging winds being the main threat.
With more clouds and rain in the area, temperatures will be a
little cooler with highs in the mid to upper 80s.
The cold front will move into the northern part of the forecast
area by Sunday morning so there will still be some chance of
showers and thunderstorms for both Saturday night and Sunday. The
front will be weakening as it moves into the region so the chance
of rain will be less than during the day on Saturday.
By Sunday night, what is left of the cold front will lift back
north as a warm front with the best chance of thunderstorms over
northern sections of the forecast area. The remainder of the
forecast period will see mostly diurnally driven convection with a
chance of thunderstorms continuing from Monday through next
Thursday. The best chance of rain each day will be mainly during
the afternoon and early evening hours. Temperatures will remain
near or slightly below normal from Monday through next Thursday.
ARS
&&
.AVIATION...
00Z TAF Set
Scattered showers will dissipate by 01Z. Stratus will then invade
the Mid-South quickly this evening. KTUP will go IFR by 4Z
followed by KMKL at 6Z. Expect the stratus to stay out of KMEM
until 07Z. KJBR will then see the stratus later around 10-12Z.
The stratus will gradually lift during the morning hours. Expect
all TAF sites to be back to VFR conditions by 19Z. Chances for
convection will occur tomorrow but timing is all over the place
depending on what short term model you look at. Could be a line of
TSRAS moving in from the west during the late morning hours based
on the HRRR while the NSSL WRF-ARW shows one moving in from the
northwest during the late afternoon hours. Regardless, expect
isolated to scattered convection outside of this potential TSRA
line to develop around the CWA. Thus, have mention of VCSH/VCTS at
all TAF sites for now. S winds of 5-10 KTs will occur overnight.
Direction will shift to the SSW or SW during the day with speeds
maintaining around 10 KTS.
KRM
&&
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...None.
MO...None.
MS...None.
TN...None.
&&
$$
Area Forecast Discussion
National Weather Service Marquette MI
737 PM EDT Thu Jun 29 2017
.SHORT TERM...(This evening through Friday)
Issued at 357 PM EDT THU JUN 29 2017
WV imagery and RAP analysis indicated a mid/upper level trough into
the the n cntrl CONUS with several embedded shortwaves. One shrtwv
and associated sfc low was moving east from ern Lake Superior.
Scattered light showers associated with this feature were departing
from the ern cwa. The next signficant upstream shrtwv was located
over nw SD. Otherwise, only a few -shra were noted upstream in
cyclonic nw flow through ne MN and nw WI.
Tonight, expect mainly isold -shra into the wrn cwa, per upstream
trends and short range models. With abundant wrap-around low level
moisture over the area, areas of fog are likely especially where
upslope wnw flow prevails. CAA will help drop temps into the 50s.
Friday, the greatest impact from the SD upstream will reamin well to
the south through WI, closest to the sfc warm front and area of
higher instability where tsra will develop. Models suggest that a
weaker sheared shrtwv will move through Upper Michigan. With
lingering low level troughing into the area, developing lake breeze
boundaris along with daytime heating pushing SBCAPEs to around 500
J/Kg, sct shra and a few tsra should again develop. Highs should
remain in the low to mid 60s north but climb into the lower 70s
south.
.LONG TERM...(Friday night through Thursday)
Issued at 301 PM EDT THU JUN 29 2017
A break is expected in the recent cool and wet pattern that has
affected Upper Michigan the last few weeks. Have to get through the
weekend through as another upper level trough will bring cooler and
unsettled weather to the region. As of right now the 4th of July
looks dry with daytime temps near normal in the 70s.
Upper level troughing begins to affect the Upper Great Lakes later
Fri into Fri night. Upper level forcing should help strengthen sfc
boundary that will remain over the area in wake of the low moving
through currently. Overall into Sat appears stronger forcing and
more extensive moisture remains more north into the upper trough
over northern Ontario but daytime heating during the aftn and sfc
based instability could help shower chances increase aftn into
evening hours on Sat, especially inland west half. Perhaps enough
instability over south central for isolated thunderstorms too with
mid 70s temps and Td around 60 leading to sfc based CAPE 750-1000
j/kg. Though most areas will see temps into the 70s, general
northerly winds btwn main area of low pressure over northern
Ontario/Quebec and high pressure over central Plains, should
keep temps along Lk Superior in the 60s.
Greatest chances of rain this weekend likely will be Sun as stronger
shortwave trough in overall mean troughing works through. Unlike Sat
rain would not follow typical diurnal trends, as it could arrive as
early as overnight Sat night but then would pretty much end mid to
late Sun aftn west into Sun evening east as stronger subsidence
pushes in behind shortwave. Colder temps at h5 with the trough will
boost mid-level lapse rates over 6.5c/km on Sun so even though there
may be more cloud cover could see at least isold thunderstorms. Best
chances again south central. Low wetbulb zero levels 6-9kft both Sat
and Sun aftn would result in stronger storms being able to produce
small hail. Shear over 30 kts is supportive for possible severe
storms on Sun but as of right now the instability does not look too
impressive (sfc based CAPE less than 500 j/kg) with more abundant
cloud cover.
Upper trough moves to eastern Canada by early next week opening the
door for more zonal W-NW flow to dominate. High pressure will be the
main weather factor so dry weather should be the rule. Will be
interesting to see how daytime dwpnts to the very wet conditions
recently. Suppose if dwpnts stay up higher with overall warming
trend (temps inland making it into the 80s potentially) there could
be isold shra/tsra try to develop especially on the lake breeze
convergence zones. Coverage would be very isolated though since
larger scale pattern is not favorable for rain. Differences in
extent of ridging aloft show up in the GFS, ECMWF and GEM late next
week. Essentially the 00z ECMWF would hold larger scale ridging
central Plains into the Upper Great Lakes. Latest GFS and GEM, and
now the 12z ECMWF as well, break down the ridge and more or less
have increasing chances of rain late next week. Tend to favor the
that idea as it matches the overall mean pattern seen for quite some
time now (troughing east and ridging west) and since it is also
supported by NAEFS and ECMWF ensembles.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 737 PM EDT THU JUN 29 2017
With abundant low level moisture lingering over the area behind a
departing low pres, expect LIFR conditions to prevail into the
morning hrs at KIWD/KCMX due to upslope w to nw flow. Some influx of
drier air on Fri will allow conditions at KIWD to improve to MVFR in
the aftn with VFR expected late. Improvement to only low MVFR is
expected at KCMX by late aftn. At KSAW, downslope nature of the w to
nw flow should help to maintain MVFR cigs thru the evening. IFR is
expected late in the night into the morning hrs. Daytime heating
should then help cigs rise to MVFR by late morning thru the aftn.
Some -ra/-dz is possible at all terminals tonight along with BR at
KIWD/KCMX.
&&
.MARINE...(For the 4 PM Lake Superior forecast issuance)
Issued at 357 PM EDT THU JUN 29 2017
As low pressure track east of Lake Superior cyclonic winds near the
low will diminish through the evening. In some locations fog may be
locally dense, Into Friday morning, winds will relax to around 10 to
15 knots as the surface pressure gradient weakens with low pressure
exiting the region. Winds through the weekend and much of next week
are expected to remain 15 knots or less.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
Beach Hazards Statement until 8 PM EDT this evening for MIZ014.
Lake Superior...
None.
Lake Michigan...
None.
&&
$$
SHORT TERM...JLB
LONG TERM...JLA
AVIATION...Rolfson
MARINE...JLB
Area Forecast Discussion
National Weather Service Omaha/Valley NE
701 PM CDT Thu Jun 29 2017
.SHORT TERM...(Tonight through Sunday)
Issued at 405 PM CDT Thu Jun 29 2017
Storms are beginning to percolate across north central
and northeast Nebraska in uncapped enviroment ahead of
surface boundary. Per 18z OAX sounding and SPC MA, area south of
interstate 80 still somewhat capped. CAM have been little
erratic on convective development, with RAP doing the best
with initiation. Mid-level shear decent with OAX sounding showing
50-60kt in mid-levels. Weak shear in the low levels, so any
tornado development likely will be coincident with surface
low and along boundary that currenly arcs along and
east of Missouri River. Used consensus blend of CAM for PoP
and weather this evening and through the overnight. Approaching
H5 short weave will allow additional storm development along
boundary that will stretch southward into Kansas. Based on
CAM, bulk of activity will be out of forecast area by 08utc.
Cyclonic flow aloft and H8 convergence will provide focus for
isolated showers and perhaps a rumble of thunder during the
afternoon. Passage of vort max late in the day, will bring large
scale subsidence across the region and a reprieve from storms by
Friday evening. Little or no precipitation threat Saturday or
Saturday night. Warm air advection and return flow may allow
for isolated convection early Sunday morning, but expect activity
to diminish by late morning.
Accepted short-term model consensus temperatures for the most
part Friday through Saturday. On Sunday, GEFS members hinting
that temperatures could be a little warmer than consensus blend.
Due to combinations of upper level ridging, H8 thermal ridge and
compressional warming ahead of southward moving surface boundary,
decided to raise temperatures a few degrees.
.LONG TERM...(Sunday night through Thursday)
Issued at 405 PM CDT Thu Jun 29 2017
Medium range models have been consistent with MCS development
Sunday night into Monday, though timing and location have varied
from run to run. Due to ongoing inconsistency, keep PoPs only in
high chance range. Perhaps a little break from precip chances
later in the day on Monday, then unfortunately, shortwave moving
through the central plains on Tuesday may dampen holiday
activities. Accepted consensus/guidance temperatures.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 659 PM CDT Thu Jun 29 2017
Ongoing convection affecting KOFK TAF site, but expect storms
to move southeast of the area by 0200 UTC. Lowest ceilings
with convection will be higher end MVFR, with occasional
thunderstorm gusts to 50kt associated with severe storms. Lingering
showers may affect the area until 05UTC. VFR conditions will
persist after 05UTC.
KOMA and KLNK TAF sites likely will begin to see storms beginning
02-03UTC. The best potential for strong to severe convection will
be 03-04 UTC, when visibilties will be reduced to 1-3SM and
thunderstorm gusts 45-50kt could occur. Per convective allowing
models, storms will affect these areas until 05-06UTC. There is
some indication of MVFR ceilings developing between 07-12UTC, but
forecast models have been somewhat inconsistent, so for the
time being keep conditions VFR after 07UTC.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...None.
IA...None.
&&
$$
SHORT TERM...Fortin
LONG TERM...Fortin
AVIATION...Fortin
Area Forecast Discussion
National Weather Service Nashville TN
717 PM CDT Thu Jun 29 2017
.UPDATE...
FOR 00Z AVIATION DISCUSSION.
&&
.DISCUSSION...
Some scattered showers are around this afternoon. HRRR has these
dying down with the loss of daytime heating. Expect another round
of showers and storms tomorrow followed by a better chance of more
widespread activity Friday night and Saturday as some upper energy
sweeps through the area. Still think we could see a couple strong
storms on Saturday with the increased bulk shear provided by the
weak shortwave. Wet microbursts would be the concern. Sunday
continues to look like the drier day this weekend. There will
still be some diurnal activity with the greatest chances south of
I-40.
Temperatures for Friday and Saturday will see highs in the mid 80s
for most locations and lows near 70. Sunday will be a couple
degrees warmer given less cloud cover and shower activity.
Monday through Wednesday will be more of the same with scattered
thunderstorms. Highs will be another couple degrees warmer with
highs touching 90 in a lot of locations. Another shortwave will
try to make its way toward the area from the central plains but
models have really slowed down the progression. Will carry 40s
pops Wednesday and Thursday until models have a better handle on
what to do with this feature.
&&
.AVIATION...
00Z TAF DISCUSSION.
CKV/BNA/MQY/CSV...Diurnal shwrs/tstms should generally dissipate
by 30/03Z with at least VCNTY shwrs/tstms possible. Some MVFR fog
and MVFR/IFR ceilings possible terminals 30/03Z-30/15Z. Next round
of diurnal shwrs/tstms should commence 30/16Z-30/24Z with at
least vcnty shwrs/tstms possible...expect at CSV where moisture
depth once again will be prominent enough along with more
pronounced upper level troughing influences to support categorical
shwrs/tstms.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
DISCUSSION......Reagan
AVIATION........31
Area Forecast Discussion
National Weather Service Pittsburgh PA
859 PM EDT Thu Jun 29 2017
.SYNOPSIS...
Temperatures will continue to warm into the weekend, and
humidity levels will also increase. This will return the risk
for showers and storms, mainly Friday and Saturday.
&&
.NEAR TERM /THROUGH FRIDAY/...
BUFKIT soundings continue to advertise a fairly strong lid on
instability as was the case on the 12z sounding this morning.
This has hardly eroded, and it likely responsible for the weak
activity that has been attempting to form to our SW and work
NEward this evening largely falling apart as it has moved toward
and into our area.
However, as a second shortwave trough tries to stream through
the upper-level flow across the northern fringe of the area,
convective activity there may start to have better luck
overcoming the cap. Upstream convection has already developed to
a larger degree than earlier HRRR and hi-res guidance
prognosticated, which yields better confidence in continuing the
PoPs across the northern reaches of the CWA the remainder of the
evening and into the overnight as it streams eastward.
Convection is showing no signs of waning as it is encroaching on
our northern PA zones, and PoPs have been summarily increased
due to increased confidence in a continuation of cap busting as
this convection treks eastward along I-80 beyond sunset.
Dewpoints continue to rise with some locations in the Ohio River
Valley touching 70F as of last hour. This will place a fairly
high floor under our overnight lows. Tonight will be several
degrees warmer than the last few nights. Fries
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SATURDAY NIGHT/...
Friday will be a similar forecast to today, save for the
additional warming and higher dewpoints. This warming in the
mid-levels may further strengthen the cap, but the higher
dewpoints will encourage instability numbers. Large scale ascent
will again be dependent on evolution of upstream shortwave
troughs, but we will be closer to the deeper parent trough and
associated surface low. For these reasons, think that we still
stand a better chance at afternoon convection, especially points
north of Pittsburgh.
Temperatures Friday will be above normal with much more
noticeable humidity levels.
Finally, by Saturday the upper-level trough will shift east
crossing sweeping the surface cold front through the area. The
result is Saturday will remain the best chance for widespread
showers and thunderstorms. Exact timing will play a big factor,
but current thinking is enough instability and shear will exist
to develop a few strong thunderstorms. Thus the current Marginal
Risk from the SPC seems prudent.
Temperatures will remain near average values, but with dewpoints
nearing 70, muggy conditions will hold.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
Mostly dry weather is expected to return Sun/Mon as surface
ridging builds underneath the upper trough. Another trough is
progged to advance E from the Midwest and Plains regions Tue,
though with uncertainty in timing and location limited POPs to
the chance category for now on the 4th of July.
&&
.AVIATION /01Z FRIDAY THROUGH TUESDAY/...
Continued with prevailing VFR conditions through the next 24
hours, although there are a couple of caveats. FKL/DUJ in
particular will need to be watched over the next several hours
as a band of showers and thunderstorms crosses Ohio into
northern PA later this evening. Expect some weakening as diurnal
heating is lost, but an approaching shortwave should allow some
activity to continue past sunset. Handled with VCSH for now and
will amend if threat increases. Isolated activity at best is
expected south to near PIT, with a dry night further south.
Southwest wind gusts will diminish over the next couple of
hours.
There is a small potential for MVFR ceilings around sunrise
especially north and west of PIT, but will hold off on this for
now pending fate of evening convection.
Better thunderstorm chances will arrive Friday as there should
be less inhibition to convective development. Scattered coverage
is anticipated, and VCTS was used to highlight this.
.OUTLOOK...
Restriction chances will continue into Saturday with the
approach and passage of a cold front.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...None.
OH...None.
PA...None.
WV...None.
&&
$$
...Update to aviation forecast discussion...
.SHORT TERM...(This evening through Friday)
Issued at 342 PM CDT Thu Jun 29 2017
Outflow boundary from the morning convection has reached portions of
southern KS. As of now the boundary is south of the forecast area
and is not showing much signs of moving northward. The cape along
and south of this boundary is around 3000 j/kg and effective shear
is around 50 kt. Storms are expected to develop in the next few
hours as the cap erodes, although north of the boundary there is
still a decent cap at 750 mb. Convection initation maybe be
somewhere southwest of Wichita where temperatures are in the upper
90s. There is also an area of agitated cumulus along the boundary
extending into southeast KS. Some of these storms could move into
portions of east central near I-35 close to the boundary. The
enhanced low level shear associated with the boundary could support
isolated tornadoes with any supercell that can develop. Of course
large hail and damaging wind gusts are also possible this evening.
Later this evening the surface trough bisects the area from
southwest to northeast and could become the focus for elevated
convection. A handful of high resolution models are hinting that
storms train along this trough and therefore pose a flash flood
threat. The WRF and HRRR ensembles are highlighting probabilities of
2 to 3 inches of rainfall in 6 hours exceeding 50 percent mainly
across east central KS. Some areas received 2 to 4 inches last night
and this morning, with the highest amounts in north central KS. The
lowest rainfall that occurred was portions of east central KS so
these locations can take a decent round of rain. Although some
isolated flash flooding cannot be ruled out especially along I-70.
An MCS is expected to move out of eastern CO this afternoon and
track into south central KS tonight. The severe activity should stay
south of the forecast area, or maybe come close to the I-35
corridor. The MCS may follow the east to west orientated outflow
boundary that still has an identity. The chances for showers and
storms continues through tomorrow morning.
.LONG TERM...(Friday night through Thursday)
Issued at 342 PM CDT Thu Jun 29 2017
Upper trough axis is expected to move through northeast Kansas
Friday night. The forcing associated with the wave along with ample
shear, moderately steep lapse rates and about 1000 J/kg of mucape
will be sufficient for some thunderstorms across north central and
northeast Kansas. High pressure will build into eastern Kansas early
Saturday morning ushering in drier air. Northwest upper flow
expected through Sunday as a ridge builds upstream over the Rockies.
A couple of waves moving through on Sunday will bring another chance
of showers and thunderstorms across south central and southeast
Kansas. Additional energy ejecting out into the Plains Sunday night
may lead to the development of elevated thunderstorms or a possible
MCS late Sunday night into Monday morning as the low level jet
increases and transports Moisture northward into north central and
northeast Kansas. Models differ on the timing and speed of an upper
level trough early next week across the central Plains. The ECMWF
and the GFS have the upper trough over central and eastern Kansas on
Independence day while the Canadian has the trough axis over
Missouri by the evening hours. Given the likelihood of the upper
trough over eastern Kansas will maintain chances of thunderstorms
Thursday night into Wednesday. Dry weather is expected for next
Thursday. Temperatures will gradually warm from Saturday through the
end of next week. Warmest temperatures will be across north central
and central Kansas.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 635 PM CDT Thu Jun 29 2017
Confidence is again rather low on specifics with convective
potential, which is again the main concern. Have sided closer to
recent HRRR guidance with best potential for thunderstorms after
06Z. Outflow winds and brief visibility restrictions look to again
be the main impacts with any TSRA. Frontal passage should bring
steady VFR conditions back in by 12Z.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Sanders
LONG TERM...53
AVIATION...65