Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 06/24/18
Area Forecast Discussion
National Weather Service Gaylord MI
949 PM EDT Sat Jun 23 2018
.UPDATE...
Issued at 947 PM EDT Sat Jun 23 2018
Overall pattern across the upper Great Lakes is pretty weak this
evening...weak low pressure (1005mb) lies over Lake Erie...with a
cold front to the north of the state just clipping far northern Lake
Superior. Well-defined short wave trough/PV anomaly over eastern
Iowa/northern Missouri evident in water vapor imagery...and showers
have been developing ahead of this feature along the Mississippi
River and tracking east-northeast. Had an "explosion" of light rain
across the tip of the mitt and Straits region starting late
afternoon...so already had to make one forecast adjustment to cover
that. Think forcing that is driving this precipitation will wane
this evening and this area of precipitation should thin over
northern Lower (but expand over northern Lake Michigan).
Meanwhile...Iowa short wave trough is expected to move across
southern Lower Michigan overnight...with an increase in shower
activity ahead of it as it interacts with deep moisture across Lower
Michigan (precipitable water values over 1.50 inches) and some weak
instability. Precipitation development likely to focus around
deformation axis to the north of this short wave trough...with some
potential for heavier downpours mainly along/south of the M-55
corridor. Flash Flood Guidance mostly over 3.00"/3hr across this
area so it`s unlikely this will be impactful. Fog also expected
to be an issue tonight over northeast Lower and the higher terrain
across the interior...could be dense in spots especially near
Lake Huron.
&&
.NEAR TERM...(Through Tonight)
Issued at 349 PM EDT Sat Jun 23 2018
...Significant rainfall possible late tonight for central Lower...
High Impact Weather Potential...Potential for locally heavy rainfall
along and south of M-55 late tonight into Sunday morning.
Pattern Synopsis/Forecast...Weakening vertically-stacked low over
the eastern Great Lakes is shearing out this afternoon with a weak
upper ridge sliding over northern Michigan in its wake. Abundant low
level moisture (PWs in excess of 1.5") over much of northern Lower
led to widespread stratus and areas of fog today, as well as
scattered morning showers. Those showers have mostly fizzled out
with the departure of the better forcing. Daytime heating across
northern Lower has been limited by the formidable cloud cover in
most areas, leaving temperatures generally stuck in the 60s (except
for Frankfort and Manistee...the only areas where temps have pushed
into the low 70s). Meanwhile, fewer clouds over eastern Upper
allowed temperatures to climb into the mid to upper 70s there. Late
this afternoon there is a possibility for some additional isolated
showers popping up south of Grand Traverse Bay. Weak low level
convergence is already starting to take shape in that area, and this
may be enough to trigger some convection, which most hi-res guidance
begins to develop around 5pm. Given weak forcing, virtually non-
existent instability, and light wind fields from the surface to the
mid levels per APX VAD wind profile and forecast soundings, this
activity should remain weak and diminish with loss of daytime
heating this evening. Had tossed in a slight chance of thunder
earlier today for this area when it looked like it might see more
sun, but since that hasn`t happened decided to remove it.
Later tonight, a digging longwave trough over eastern Canada will
carve out a potent shortwave over northwest WI and northern Lower
MI. This stronger forcing looks much more promising for producing
more significant rainfall south of M-72 where the corridor of higher
PWs (in excess of 1.5") will reside, and especially along/south of M-
55. Models have been hinting at this since at least yesterday, but
today there is good agreement, and 12Z hi-res guidance strongly
supports the idea. Time of arrival will be well after midnight,
perhaps closer to daybreak Sunday for some areas. The concern is
that this activity will be slow-moving given the anemic synoptic
wind profile, and combined with significant forcing and abundant
moisture...will this lead to prolonged heavy downpours for some
areas? Latest HRRR reflectivity paints this picture and frankly
looks a bit concerning. HREF ensemble mean precip shows localized
rainfall in excess of 1 inch along/south of M-55 by 8 AM Sunday, but
individual members do show potential for locally 2+ inches in spots.
Areas most at risk for this very heavy rainfall would be roughly
from around Manistee to Gladwin, with lighter amounts across the
rest of northern Lower and likely very little across eastern Upper.
The good news is that given how dry we`ve been lately (25 to 75% of
normal for month-to-date rainfall), think the ground shouldn`t have
too much issue handling these amounts...unless significant rainfall
occurs over a very short period of time. Latest 3 and 6 hour flash
flood guidance would require around 2 to 4" of rainfall to lead to
issues along/south of M-55, so not anticipating too much cause for
concern. But we`ll be monitoring this potential closely as new model
data comes in through the evening. Instability will be limited, but
forecast soundings show classic near-saturated column with tall,
skinny CAPE. Not anticipating storms given very low instability, but
wouldn`t entirely rule out a rumble of thunder or two.
&&
.SHORT TERM...(Sunday through Tuesday)
Issued at 349 PM EDT Sat Jun 23 2018
...Active weather pattern continues...
High Impact Weather Potential: Possible thunder Tuesday.
Pattern Synopsis/Forecast: A more active weather pattern continues.
Heavy rain is forecast south of M-55 with a shortwave over lower
Michigan. This may produce an additional 0.25 to 0.50" (locally
higher) than what falls during the overnight hours. Will have to
keep an eye out for any flooding threats. The rest of northern lower
will see lingering shower chances throughout the day...before
finally diminishing Sunday evening/night as high pressure centered
over Hudson Bay builds into northern Michigan along with much drier
air and aforementioned shortwave departs to the southeast. This high
pressure will diminish cloud cover from north to south beginning
Sunday night and provide a mostly clear and pleasant Monday
afternoon. Clouds will be on the increase once again Tuesday as a
low pressure system over the the central Great Plains brings our
next chances of rain Tuesday through Wednesday as it tracks through
the northern Great Lakes. Thunder chances will increase throughout
the day Tuesday as the warm front associated with the aforementioned
low pressure system provides some additional lift. Have thunder in
the forecast, but not too impressed with the bulk shear values (only
in the realm of 20-30kts). Best chances will be during the late
evening into Wednesday as a southwesterly low-mid level jet forms
ahead of the cold front associated with said system, along with
increasing ingredients for thunderstorm development. A fairly light
wind regime will remain throughout the forecast period.
Highs Sunday through Tuesday will reach into the 70s, while lows
will drop into the upper 40s to low 50s.
.LONG TERM...(Tuesday night through Saturday)
Issued at 349 PM EDT Sat Jun 23 2018
High Impact Weather Potential: Possible Storms Tuesday night into
Wednesday.
A shortwave moving in from the Northern Plains will support showers
and storms Tuesday into Wednesday. Some deep moisture and
instability have the potential to line up over the region, but
whether or not the best shear/support is in the right place at the
right time remains to be seen. As the frontal boundary sweeps
through the region on Wednesday, showers and thunderstorm chances
should diminish late in the day. A ridge starts to build into the
area late in the week, allowing temperatures to climb and stay above
normal to end the workweek.
&&
.AVIATION...(For the 18Z TAFS through 18Z Sunday afternoon)
Issued at 200 PM EDT Sat Jun 23 2018
IFR ceilings will gradually shrink in coverage as afternoon
heating develops, but MVFR will still be fairly widespread. Also
some stubborn BR holding on at APN with IFR visibilities expected
for the next few hours. Latest radar and satellite imagery show
showers and widespread cloud cover starting to slowly diminish,
but some additional light showers (perhaps a rumble of thunder)
may develop near TVC/MBL later this afternoon.
A fairly strong disturbance will cross northern Lower overnight.
With lingering abundant low level moisture, this will likely lead
to more widespread/heavier shower activity after 06Z. MBL and TVC
will be most impacted by any heavier rainfall. MVFR to IFR cigs
are likely once again, with some visibility restrictions from
heavier rainfall. APN is likely to be impacted by some additional
BR overnight. Shower chances diminish through the day Sunday with
cigs slowly improving towards afternoon. Winds will remain light
(< 10 knots) through the period.
&&
.MARINE...
Issued at 349 PM EDT Sat Jun 23 2018
Winds and waves will remain below SCA criteria through the
remainder of the weekend. Rain chances will remain for most of our
nearshore areas over Lake Huron today through Sunday as an area
of low pressure meanders over the Great Lakes. Lake Michigan may
see some rain showers tonight through Sunday morning. Do not
expect any thunderstorm activity thru the weekend.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&
$$
UPDATE...JPB
NEAR TERM...MK
SHORT TERM...TL
LONG TERM...STJ
AVIATION...MK
MARINE...TL
Area Forecast Discussion
National Weather Service La Crosse WI
623 PM CDT Sat Jun 23 2018
.SHORT TERM...(Tonight through Sunday Night)
Issued at 205 PM CDT Sat Jun 23 2018
Partly sunny skies prevailed across the region this afternoon.
Temperatures were in the middle 70s to lower 80s.
For tonight and Sunday, there is still a lot of uncertainty in
timing and location of precipitation chances. Models do show a weak
disturbance moving across the area on Sunday which could trigger
shower activity along with a small chance of thunderstorms. Per
coordination with surrounding offices, slowed down the chances of
rain until very late tonight, and more likely Sunday morning. The
GFS/Canadian are more aggressive with rainfall totals while the
ECMWF indicated the lowest rainfall totals during the day Sunday
which gives uncertainty in rainfall amounts and actual coverage of
showers. Based on the latest model trends, highest chances of rain
will be across southeast Minnesota, northeast Iowa and southwest
Wisconsin north of Interstate 90.
Took a blend of model guidance for lows tonight similar to the
trends of last night although slightly warmer in spots. Did not
stray far from guidance for highs on Sunday.
Shower/slight thunderstorm chances shift westward Sunday night as
better moisture transport redirects across central IA into southwest
MN.
.LONG TERM...(Monday through Saturday)
Issued at 205 PM CDT Sat Jun 23 2018
Main concern through this period will be heavy rain/severe potential
mainly Monday night into Tuesday as a vigorous mid-level closed
low/surface low rotates northeast through the area. NAM/GFS models
in good agreement with increasing feed of moisture transport into
the area which is maximized Monday night into early Tuesday morning
with noctural 850mb jet. As a result, precipitable water values
increase into the 1.5-2 inch range Tuesday. CAPE and bulk shear will
depend on track of the mid-level low. NAM keeps higher CAPE pool
south of I-90 while the GFS brings in a respectable n/s corridor of
2-3KJ/Kg across the entire area along with bulk shear in the 20-40Kt
range (mainly south of I-90). So, will definitely have to keep an
eye on heavy rain and severe thunderstorm potential for this time
frame.
Wednesday is looking dry at this point as a ridge of high pressure
builds over the area.
Thursday through Saturday could be active as several convective
complexes make their way out of the Plains and over the ridge into
our area. Bulk of this activity looks like it would be along and
north of I-94. Otherwise, look for high through the period well into
the 80s.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 623 PM CDT Sat Jun 23 2018
A few showers have developed late this afternoon as a weak short
wave trough moves across Iowa. Very limited instability in place
with maybe 750 J/kg of MUCAPE, but enough that there could be a
rumble of thunder. The showers are drifting slowly to the
southeast and will include a VCSH at KRST for a couple of hours
until the instability dissipates with the loss of daytime heating.
After that, some concern again for fog in the river valleys. The
cloud cover should diminish overnight but expecting some clouds to
remain for much of the night. Light winds again through a deep
layer will be favorable for formation but the 23.18Z NAM and
23.21Z RAP do not show saturation occurring at the surface. For
now, will not include any mention of fog and will monitor trends
through the evening for possible inclusion with later forecasts.
Another small chance for some showers Sunday afternoon west of the
Mississippi River as a short wave drifts into central Minnesota
and will maintain the VCSH at KRST.
&&
.HYDROLOGY...
Issued at 205 PM CDT Sat Jun 23 2018
Area rivers continue to run higher than normal with some minor
flooding occurring or forecast to occur in places. Concern is there
for the possibility of more flooding heading into next week. A
vigorous storm system rotating through the region Monday night
through Tuesday night may have the biggest impact as precipitable
water values increase into the 1.5-2 inch range. This could
translate into pockets of very heavy rainfall which could lead to
some flooding. Will be keeping a close eye on the evolution of this
system. Wednesday looks dry but then there is the potential for
several convective complex to rumble through the area Thursday
through Saturday. This keeps the concern for flooding notched up a
bit.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
IA...None.
&&
$$
SHORT TERM...RE/DAS
LONG TERM...DAS
AVIATION...04
HYDROLOGY...DAS
Area Forecast Discussion
National Weather Service Birmingham AL
939 PM CDT Sat Jun 23 2018
.UPDATE...
Evening Update.
&&
.SHORT TERM...
Canceled the Tornado Watch just slightly early as the convection
has decreased significantly in intensity and coverage. With the
loss of daytime insolation, temperatures have fallen allowing some
CIN to form. With very limited surface convergence, not expecting
much additional development overnight. Adjusted rain chances and
bumped them northward the remainder of the overnight hours.
75
Previous short-term discussion:
Several rotating storms have developed over areas from Vernon to
Double Springs. These storms will continue eastward the next few
hours with damaging winds, quarter size hail and a tornado
possible. The rotation has been well entrenched in the mid levels
and have not seen too much evidence of any lowering. It appears
that low level winds and convergence are weaker and the rotation
is having a very hard time building down. LCL`s do lower in
northern areas and we are also entering times just after sunset
where it typically goes down. Bulk Shear values are around 30kts,
so some organization is possible. This value is lower than
yesterday under nearly the same environmental parameters.
Effective helicity values are around 200, and as evidenced,
rotation is taking place. A mid level disturbance is moving over
the region and helping ignite this activity. Will monitor these
storms closely the next few hours and expect a decrease by mid
evening.
75
Previous short-term discussion:
Through early this evening.
We`re continuing to re-evaluate the forecast for this afternoon
and evening in terms of the severe weather potential across
Central Alabama. Earlier activity from the previous MCS has
weakened considerably, with the leftover outflow boundary now
pushing into Chambers and Lee County. Behind that cold pool lies a
much more stable airmass, and many locations remain in the 70s.
However, clouds are quickly trying to clear enough for some
daytime heating. We`re now at 82 degrees here at the Shelby
County Airport. Meanwhile, locations farther south and west that
were unaffected by the MCS this morning are already quite warm
into the upper 80s.
As the severe threat ends across the far northeast counties
through the early afternoon hours, we`ll continue to watch
additional development to our west. Large outflow boundaries from
previous convection are racing our direction from Mississippi and
Arkansas. Those boundaries may trigger additional convection this
afternoon within areas that will be very unstable. RAP forecasts
are pointing at 3000-4000 J/KG of SB CAPE building into at least
our far western/southwestern counties by late this afternoon.
However, the RAP is currently not doing a good job of taking into
account the large subsidence zone that`s currently in place. It`s
also unclear if we`ll have enough lift by those outflow
boundaries moving in from the west to trigger those storms. The
HRRR and other mesoscale guidance is starting to hint at more
development following almost no development a few hours ago.
Therefore, much uncertainty remains in today`s severe weather
forecast. For now, will leave our current forecast as-is with the
potential for additional development. Based on additional guidance
and observation trends this afternoon, we`ll likely be updating
our severe threat graphic by 4pm. Damaging straight-line winds
will remain the greatest hazard.
56/GDG
.LONG TERM...
Sunday through Friday.
Height rises on Sunday should lead to hotter conditions and very
minimal prospects for rainfall. The upper-level ridge should
continue to limit rain chances on Monday and Tuesday, but isolated
convection cannot be ruled out. The ridge may weaken on Wednesday
as a trough moves through the Great Lakes and Ohio Valley. There
is good model support for a weak shortwave near the base of the
trough over the Tennessee Valley which would lead to enhanced
rain chances. This features may end up getting pulled south and
west across the forecast area on Thursday and Friday as ridge
develops to our north. This scenario would lead to a continuation
of somewhat enhanced rain chances.
87/Grantham
&&
.AVIATION...
00Z TAF Discussion.
Next upper level disturbance was entering western Alabama and
kicking off a few thunderstorms. These storms will have the
potential of producing some gusty winds, a tornado and frequent
lightning. At this time, the storms are expected to diminish by
around 10 pm. but not completely go away. Added a mention of VCTS
at TCL/BHM and have skipped all other terminals. High pressure
builds over the region on Sunday and shower/storm chances go way
down. Will not mention any convection for Sunday but an isolated
storm is possible with chances only about 10 percent.
MVFR ceilings are possible again overnight. The best chance will
be south and have clouds around 015 after 06z. Northern areas was
not quite as confident but have a tempo group of ceilings at 025.
Ceilings rise and thin by 15-16z and southwest winds continue at
8kts or so.
75
&&
.FIRE WEATHER...
High rain chances will continue for today especially across the
northern third of the area. Patchy fog may develop in the
overnight and early morning hours where rainfall occurs. Rainfall
is not expected on Sunday as a suppressive ridge develops. There
are no fire weather concerns at this time.
&&
.PRELIMINARY POINT TEMPS/POPS...
Gadsden 69 91 71 92 71 / 40 10 10 30 10
Anniston 69 91 72 93 72 / 20 10 10 30 20
Birmingham 73 93 74 94 74 / 30 10 10 30 10
Tuscaloosa 74 95 74 95 74 / 10 10 10 30 10
Calera 73 92 73 93 73 / 20 10 10 30 20
Auburn 72 91 73 92 74 / 10 10 10 30 20
Montgomery 73 93 75 94 75 / 10 10 10 30 20
Troy 74 92 73 93 74 / 0 10 10 30 20
&&
.BMX WATCHES/WARNINGS/ADVISORIES/...
None.
&&
$$
Area Forecast Discussion
National Weather Service Burlington VT
730 PM EDT Sat Jun 23 2018
.SYNOPSIS...
Deeper moisture will linger over the North Country tonight with
plenty of cloud cover...the threat of some showers...and patchy
fog. We will lose the fog Sunday morning but expect plenty of
clouds and occasional showers as a trough of low pressure moves
into the region. Eventually the trough moves east of the region
on Monday with drier air returning to the area Monday into
Tuesday as high pressure builds in. Temperatures will be
returning to seasonal normals during this time period as well.
&&
.NEAR TERM /THROUGH SUNDAY NIGHT/...
As of 730 PM EDT Saturday...Opted to adjust PoPs somewhat
downward overnight from a area-wide perspective, generally into
the 20-40% range. Latest WV imagery showing weak shortwave
tracking across the southern tier of NY as of early evening.
Progs suggest this feature will swing through the area later
this evening but with areal shower coverage scattered at best
with many spots remaining largely dry overnight outside a
passing sprinkle. HRRR output seems to have the best handle on
this evolution so leaned in its direction accordingly. Cloudy
skies certainly the rule with weak low level blocked flow and
decent boundary layer RH, which suggests more of a low stratus-
type night as opposed to fog. As such, have adjusted areal
coverage of any real fog to elevations generally above 1000-1500
feet which have higher probabilities to lie within the cloud
layer itself. The rest of the forecast in regard to winds and
temperatures etc. remains on track. Have a great evening.
Prior discussion...
On Sunday we will see a somewhat similar scenario to Saturday.
After any fog burns off early Sunday we will still have plenty
of clouds around and as an upper trough moves into the
region...we should see showers flare up again. Not a complete
washout but periods of showers throughout the day...especially
in the afternoon. Highs will be in the upper 60s to the mid 70s.
Showers will begin to end from west to east Sunday night as the
upper trough slowly moves east of the region. Any showers will
mainly be across Vermont along with the most cloud cover. Lows
will generally be in the 50s.
&&
.SHORT TERM /MONDAY THROUGH MONDAY NIGHT/...
As of 410 PM EDT Saturday...North to northwest flow aloft will
remain over the area through much of this period. As a
result...complete clearing will be a slow process and there
could still be some showers around on Monday...especially over
eastern Vermont as one last shortwave drops down into the base
of the upper trough as it is exiting Vermont. Generally keeping
precipitation chances in the slight chance range. Highs will be
in the upper 60s to mid 70s. More pronounced clearing takes
place Monday night with high pressure building in. Lows will
generally be in the 40s to lower 50s with some upper 30s in the
mountains.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
As of 410 PM EDT Saturday...Quiet weather is expected for the
first part of the extended with sfc high pressure building in
behind a departing low pressure system to the east. High temps
Tuesday will be right around normal in the upper 70s to around
80. Lows Tuesday night will provide good sleeping weather with
temps in the mid to low 50s with minimal humidity. Clouds will
begin to increase overnight Tuesday into Wednesday ahead of our
next system approaching from the west. New 12z Euro guidance has
sped things up by a few hours with precip over- spreading VT by
00z Thursday, but have trended closer towards 00Z Euro and 12z
GFS with the idea of showers making their way into the St.
Lawrence valley towards 00z Thursday and moving eastward through
the overnight hours...with drier air in place at sfc, initial
precip may not reach the ground. Additionally, can`t rule out a
rumble of thunder across St. Lawrence valley with some minor
instability present, so have mention of slight chance of thunder
in the grids for points W of Adirondacks. As sfc low pressure
tracks slowly northeastward of international border, precip will
be slow to exit the area during the day Thursday. With a weak
disturbance passing along the international border behind the
main shortwave Thursday night have also kept some lingering
slight chance of showers and clouds in the grids through 12z
Friday.
After this system, our attention turns towards a potential heatwave
kicking off the second weekend of summer. Models are in good
agreement on a subtropical ridge over the eastern US towards the end
of next week with both GFS and Euro showing near 595dm thicknesses
positioned across the Mid-Atlantic/New England on Saturday. Initial
925 temps between 24-27C suggest high temperatures in the mid to
upper 90s but right now haven`t gone completely bullish on high
temps for Friday/Saturday...have adjusted Superblend temps up a few
degrees just to show warming trend. At this time, Friday/Saturday
highs are in the upper 80s Friday/low 90s Saturday but may need to
adjust up more as we get closer. Lows through this period will also
be significantly above normal with temps Friday/Saturday night in
the upper 60s to low 70s. Chances of precipitation look minimal
Friday/Saturday due to mid-level subsidence however have mention of
slight chance of thunderstorms in the grids...should anything
develop this warm environment will be conducive to producing
thunder.
&&
.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
Through 00Z Monday...Widespread MVFR and light winds through
much of the forecast period with scattered IFR overnight and
higher terrain obscured. Highest probs for IFR to occur at KSLK
and KRUT in the 06-13Z time frame. After 18Z Sunday some slow
improvement in cigs expected, especially at KMSS/KPBG/KBTV where
the forecast will show levels lifting to VFR. In terms of
precipitation widely scattered showers will traverse the area
through the period with best coverage overnight and again after
18Z on Sunday. Widely scattered to scattered nature of coverage
warrants only VCSH at this point however.
Outlook...
Sunday Night: Mainly VFR, with local IFR possible. Chance SHRA.
Monday: Mainly VFR, with local MVFR possible. Slight chance SHRA.
Monday Night: VFR. NO SIG WX.
Tuesday: VFR. NO SIG WX.
Tuesday Night: VFR. NO SIG WX.
Wednesday: VFR. Chance SHRA.
Wednesday Night: MVFR. Likely SHRA, Slight chance TSRA.
Thursday: MVFR. Chance SHRA.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...None.
NY...None.
&&
$$
SYNOPSIS...Evenson
NEAR TERM...JMG/Evenson
SHORT TERM...Evenson
LONG TERM...Banacos/LaRocca
AVIATION...JMG
Area Forecast Discussion...Updated
National Weather Service Billings MT
855 PM MDT Sat Jun 23 2018
.UPDATE...
Precipitation had remained generally isolated to scattered through
the evening as the upper low moved through the area. Some storms
likely produced heavy rainfall based on PW`s close to an inch and
the high reflectivities seen on radar. As of 0245Z, there were a
few dying echoes in the far E, a cluster of showers and isolated
thunderstorms over S. Big Horn and Sheridan Counties, and other
showers over Wheatland County. CAMS models had varying placement
of generally isolated showers/thunderstorms tonight, so went with
radar trends for early tonight, then blended with CONSShort, which
gave isolated PoPs overnight for most of the area, and scattered
PoPs over S. Big Horn/Sheridan Counties under track of the low
with it`s vorticity. RAP soundings were stable after 06Z across
the area, so removed thunder overnight. Adjusted sky cover and
winds based on current trends. Not concerned about fog as there
will be a fair amount of cloudiness overnight. Other forecast
parameters looked good.
The low will shift E into SD/NE during Sunday and an inverted
trough will keep a good chance of precipitation over the eastern
zones. Arthur
&&
.SHORT TERM...valid for Sun and Mon...
Upper trough over western Montana will drop southeast into NE
Wyoming by Sunday morning. This will create enough instability
and broad ascent to support isolated to scattered showers and
thunderstorms through Sunday evening. We may also see some snow
showers over the higher elevations tonight, including the
Beartooth Pass. EBS (effective bulk shear) is not very impressive
so we are generally expecting garden variety thunderstorms through
the rest of the weekend with small hail and perhaps brief heavy
rainfall. The upper low moves off to the east by Monday with some
ridging and drying over most of our CWA. Some risk of storms
will linger along the Montana/Dakota border Monday afternoon.
Highs Monday will push well into the 80s for most areas.
The main adjustments for this package were to lean the highest
PoP`s more toward the east Sunday as the latest progged QPF
suggest more widespread precipitation to our eastern counties.
This makes some sense as latest models have the upper low a little
further east than previous runs. BT
.LONG TERM...valid for Tue...Wed...Thu...Fri...Sat...
The extended did not have many changes with the latest guidance.
Tuesday still has a weak cold front move through the area. While
the models do not generate much QPF, have generally kept PoPs the
same. Given the moisture in the area cannot rule out there being
more activity than the models are project. Thursday looks to be
dry ahead of the next trough starting to work into the area
Friday. In general the models continue to show another active
pattern as a low drops down into the Northern Rockies. It still
looks like there could be some decent rainfall amounts again with
this next weekend. Reimer
&&
.AVIATION...
Isolated showers and a few evening thunderstorms will bring local
MVFR to IFR conditions due to heavy rainfall. Occasional mountain
obscuration can be expected through tomorrow morning. Otherwise
VFR conditions will prevail tonight. Chambers
&&
.PRELIMINARY POINT TEMP/POPS...
Sun Mon Tue Wed Thu Fri Sat
-----------------------------------------------------------
BIL 054/074 056/085 060/078 055/082 057/080 055/074 054/072
24/T 21/U 12/T 20/U 12/T 43/T 44/T
LVM 049/072 049/084 055/077 047/080 050/079 049/071 047/068
22/T 10/U 12/T 20/U 12/T 43/T 44/T
HDN 054/074 054/085 058/079 054/083 056/082 055/076 053/074
25/T 31/U 12/T 20/U 12/T 43/T 44/T
MLS 058/075 058/082 061/081 055/081 059/083 058/077 056/074
26/T 31/U 12/T 20/U 12/T 43/T 44/T
4BQ 056/072 056/080 058/083 055/083 058/084 057/077 056/076
26/T 42/W 11/U 20/U 12/T 33/T 54/T
BHK 055/073 056/077 057/083 053/080 056/082 055/076 054/075
26/T 42/T 11/U 20/U 12/T 44/T 45/T
SHR 052/069 051/080 056/080 052/082 055/082 053/075 050/074
65/T 31/U 11/U 20/U 12/T 33/T 44/T
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...None.
WY...None.
&&
$$
weather.gov/billings
Area Forecast Discussion
National Weather Service Cheyenne WY
227 PM MDT Sat Jun 23 2018
.SHORT TERM...(This evening through Monday night)
Issued at 225 PM MDT Sat Jun 23 2018
Scattered showers and a few storms developing over northwest parts
of the CWA ahead of the next upper low evident on satellite over
western Montana. Expect convection to continue to increase through
this evening as the upper low moves towards the CWA overnight. Some
potential for heavy rainfall exists especially over northern parts
so the current flood watch looks fine. Rain may taper off some later
tonight as suggested by the HRRR but should increase again Sunday
as the upper low drifts slowly east into western Nebraska.
Instability not too high Sunday/ CAPES about 500-900 J/kg over the
NE Panhandle/ and latest SPC outlook has slipped the Slight risk
east of the CWA but a few stronger storms still may occur over the
NE Panhandle. Locally heavy rainfall still possible with stronger
storms. The upper low will continue to drift slowly eastward Sunday
night and Monday with showers and a few storms persisting over the
NE Panhandle in wrap-around flow. Monday night looks dry with clearing
skies.
.LONG TERM...(Tuesday through Saturday)
Issued at 225 PM MDT Sat Jun 23 2018
Some changes gleaned from the 12Z medium range models/ensembles.
Northwest flow aloft downstream of upper ridge early Tuesday becomes
zonal as shortwave energy translates east across far southern
Canada through Wednesday night. Flow aloft backs to the southwest
as a upper trough deepens over the northwest CONUS Thursday and
Friday. The GFS is deeper/slower than the ECMWF with this trough.
A weak surface front slips southward into the high plains
Wednesday and stalls along the Laramie Range Wednesday night. No
convection is forecast with this boundary, which shifts northward
as a warm front Thursday. This front again drifts southward with
the passage of a shortwave across the Dakotas. Isolated convection
is possible Thursday evening north and east of a line from
Douglas to Scottsbluff. A low pressure system develops over
northern WY Friday and tracks to the east in SD Friday night, with
front sagging south into portions of eastern WY and northern NE.
Isolated to scattered convection may develop as far south as
Wheatland, Scottsbluff and Alliance Friday night and Saturday.
Above normal temperatures will prevail through the long term with
highs in the 80s to mid 90s Tuesday and Thursday, and 80s
Wednesday, Friday and Saturday.
&&
.AVIATION...(For the 18Z TAFS through 18Z Sunday morning)
Issued at 1155 AM MDT Sat Jun 23 2018
Generally VFR. Scattered showers and thunderstorms will develop this
afternoon, becoming more numerous this evening. Onset will be between
20Z and 23Z in southeast WY, and after 23Z in western NE Panhandle.
Brief gusty/erratic winds, moderate turbulence and small hail will
accompany the stronger convection along and east of I-25. TSRA will
weaken to SHRA later this evening. Winds will shift to northerly as
a cold front passes through this evening.
&&
.FIRE WEATHER...
Issued at 225 PM MDT Sat Jun 23 2018
A low pressure system in the upper atmosphere will move across the area
through Sunday bringing widespread showers and thunderstorms, with
wetting rainfall in many areas. Heavy rainfall is possible, especially
over northern districts. The low pressure system will move east of the
area Sunday night and Monday with rain coming to and end. Warmer and
mainly dry weather is expected by midweek.
&&
.HYDROLOGY...
Issued at 225 PM MDT Sat Jun 23 2018
Scattered to numerous showers and thunderstorms will develop this
afternoon and evening across southeastern Wyoming and the western
Nebraska Panhandle. 700 mb mixing ratios over 7 g/kg will be more
than adequate for heavy rainfall with the stronger cells, with
accumulations over an inch through Sunday evening. Although storm
motion will not be particularly slow, training storms and already
saturated ground may cause localized flooding across the flood watch
area.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...Flood Watch from 6 PM MDT this evening through Sunday evening
for WYZ101>103.
NE...None.
&&
$$
SHORT TERM...RE
LONG TERM...MAJ
AVIATION...MAJ
FIRE WEATHER...RE
HYDROLOGY...MAJ/ADL
Area Forecast Discussion
National Weather Service Grand Forks ND
950 PM CDT Sat Jun 23 2018
.UPDATE...
Issued at 946 PM CDT Sat Jun 23 2018
Convection continuing this evening along an east to west corridor
between Fargo and Grand Forks. Strength and coverage are
decreasing as lightning levels and cloud tops are less intense
over the past hour than earlier this evening. Activity will be
mostly finished by midnight as this rate with a few isolated
showers possible through the overnight mainly in the south valley.
&&
.SHORT TERM...(This evening through Sunday)
Issued at 309 PM CDT Sat Jun 23 2018
Showers and thunderstorms, their strength and coverage, will be
the main issue for the period.
Water vapor loop and rotation of the radar returns shows the main
upper low is still to our southwest over south central ND/north
central SD. There has been thunderstorm activity developing during
the early afternoon hours across a couple of old boundaries. One
lingering front in the Lake of the Woods area has created enough
surface convergence for some slow moving thunderstorms. Another
surface boundary stretching from the Devils Lake basin in to west
central Minnesota has been the focus for additional thunderstorm
development, with the greater coverage on the ND side. SPC meso
page has a non-supercell tornado parameter around 4, and low level
CAPE and surface vorticity are maxed out in that area. Surface
vorticity is much weaker with the cells down in west central MN.
Will have to keep a close eye for any funnel formation during the
next few hours, but the RAP has the best vorticity moving away
from the highest low level CAPE values by 21-23Z.
The loss of daytime heating will reduce coverage of showers and
thunderstorms as we head into the overnight hours. However, the
weakening upper low will still be drifting eastward into the area
and many of the high resolution models have lingering convective
activity hanging around into 06Z and beyond. Best chances will be
near the surface low in northeastern SD, so have some chance POPs
lingering in our south and west with more isolated activity
elsewhere. Temps should drop into the 60s overnight with at least
some clearing.
By tomorrow, the eastern upper low over our region will have
weakened and merged with the western circulation moving from the
Northern Rockies into the Northern Plains. More showers and
thunderstorms will develop again by afternoon thanks to daytime
heating, with the best chances in the southwest closest to the
upper system. It looks to be a another day with decent instability
(around 1000 J/kg of CAPE), but weak deep layer bulk shear.
Temperatures should be a couple of degrees cooler than today
thanks to cloud cover.
.LONG TERM...(Sunday night through Saturday)
Issued at 309 PM CDT Sat Jun 23 2018
Deepening upper low caught on the southern limb of split flow will
slide to the south and east of the region Sunday through Tuesday.
This will keep rain chances within the forecast Monday and Tuesday
will keeping temperatures mild and skies cloudy. Areas that hold
best chances for rain reside in the southern Red River Valley into
west-central Minnesota. Thunderstorm chances Monday will be limited
on these days due to clouds hindering diurnal destabilization and
weak mid level lapse rates. A cold front slowly approaches from the
west late Tuesday into Wednesday bringing the chance for scattered
showers and thunderstorms.
By mid week zonal flow aloft will set up transitioning to
southwesterly flow towards late week. This will allow thunderstorm
chances and the temperature trend to increase late next week.
Surface high pressure behind Wednesday`s stalling cold front should
keep conditions dry for at least one day, progged to be Thursday.
This is short lived as southwesterly flow aloft will swing embedded
disturbances over the Northern Plains. There may be an uptick in
strong to severe thunderstorm chances late next week as better wind
shear associated with the aforementioned embedded disturbances
develops over the Northern Plains along with the chance for
instabiility and moisture content to grow over the area. A number of
factors including frontal placement and shortwave passage timing
will prevent any further details from being forecast at this time.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 641 PM CDT Sat Jun 23 2018
Widespread convection will continue across the area this evening.
Light winds will persist through the TAF period with more showers
and thunderstorms tomorrow.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...None.
MN...None.
&&
$$
UPDATE...JK
SHORT TERM...JR
LONG TERM...CJ
AVIATION...JK
Area Forecast Discussion
National Weather Service Wichita KS
928 PM CDT Sat Jun 23 2018
.UPDATE...
Issued at 925 PM CDT Sat Jun 23 2018
Convective evolution remains a challenge overnight and on Sunday.
Per radar trends so far this evening, HRRR seems to be on the right
track. 0000 UTC surface/raobs show band of richer/deeper moisture
across southwest half of OK, pointing into far western KS. This
bodes well for HRRR idea of western KS convection continuing to
track southeast with the west-north west flow aloft. The main
issue is how far east the precipitation will go. HRRR pushes
precipitation all the way into southeast KS by mid morning. This
seems to be a stretch, given HRRR tendencies this past week, but
possible if 850MB flow veers. This complicates forecast for
Sunday, as HRRR breaks out a band of altocumulus castellanus and
showers in the elevated baroclinic zone over the Flint Hills,
while keeping the low level moisture/thermal gradient well west of
of the forecast area throughout the afternoon. This would
significantly delay the onset of robust convection in the forecast
area. Adjusted overnight forecast for now to increase the chance
of rain, and will let the mid shift watch trends overnight and
make adjustments to the Sunday afternoon-evening periods after
perusing the entire 0000 UTC model suite. -Howerton
&&
.SHORT TERM...(This evening through Tuesday night)
Issued at 405 PM CDT Sat Jun 23 2018
The main forecast concerns will be severe weather potential Sunday
into Sunday night.
Will maintain slight chances (20-30%) of thunderstorms tonight into
Sunday morning. This would be for the possibility of a storm cluster
or two propagating east-southeastward off of the High Plains, along
with strengthening 850-700 warm air advection and moisture
transport. The HRRR, 18z NAM-WRF, 12z GFS models are more aggressive
with this initial convective potential in comparison to some of the
other high resolution models. Strong/gusty winds would be the main
threat with any of these storm clusters. If this convection is more
widespread and lingers well into Sunday morning, possible outflow
effects will make overall convective evolution into Sunday
afternoon/night much more uncertain and challenging.
A strong shortwave trough will move out of the northern Rockies over
the Central Plains Sunday into Monday. A 40-50 knot southwesterly
mid-level jet streak will accompany this trough as it moves out over
Kansas. Barring widespread convective outflow effects (mentioned
above) materializing, a very moist and strongly unstable airmass
(MLCAPE of around 4,000 J/KG) and 35-40 knots of deep layer shear
will be in place ahead of the approaching cold front. Most short-
range models indicate storms developing on the cold front over the
central High Plains by midday Sunday, then traversing southeastward
Sunday afternoon into Sunday night. These storms should propagate
southeastward into central/south-central Kansas counties Sunday
afternoon or evening with upscale growth into one or more damaging
MCS`s. The main threats Sunday afternoon/night appear to be
widespread damaging winds, with high-end severe gusts possible. A
few large to very large hail reports are possible mainly Sunday
afternoon. Strong 850 mb moisture transport and upper divergent flow
will support the potential for thunderstorms across much of the
forecast area Sunday night. Anomalously high precipitable water will
support locally heavy rainfall/flooding, and strong to severe wind
gusts with storms Sunday night.
Will maintain a chance of thunderstorms Monday into Monday night
across eastern Kansas, however this will strongly depend on where
the effective front/boundary ends up due to outflow effects from
widespread storms Sunday night. A few strong to marginally severe
storms will be possible.
.LONG TERM...(Wednesday through Saturday)
Issued at 405 PM CDT Sat Jun 23 2018
Confidence is high in above normal temperatures given the large
scale upper pattern agreement with the GEFS and EPS medium range
guidance. Upper ridge development is progged over the south-central
Plains Wednesday into Thursday, before sliding over the
eastern/southeastern CONUS by Friday/Saturday. Mean upper troughing
will develop over the western states. Resultant lee troughing will
allow for breezy southerly winds and hot and humid weather across
the forecast area for mid to late week. High temperatures will
likely approach or exceed the century mark by a few degrees across
central/south-central Kansas, with lower-middle 90s in the
southeast. Balmy overnight lows in the 70s are expected. Peak
afternoon heat indices of 100-105 are projected. Residual chances of
thunderstorms could linger mainly over northeast Kansas Tuesday into
Tuesday evening, otherwise rain chances from Wednesday through
Saturday look slim to nil.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 640 PM CDT Sat Jun 23 2018
Convective evolution will be the main concern throughout the
period. Track of current storms in northwest KS problematic, with
a plethora of model solutions from which to choose. Would appear
that storms will turn to a more southerly track with onset of low
level jet. HRRR which seems to be handling ongoing storms best,
breaks out precipitation in moisture warm air advection on eastern
side of outflow boundary around 0900 UTC over the Flint Hills.
Course this is dependent on size and track of initial complex. All
of this then compounds what happens on Sunday with timing and
magnitude of storms. For now, have kept near term part of the
forecast dry, with some VCTS near end of the period at KGBD, KRSL
and KSLN. Confidence in forecast is low. -Howerton
&&
.PRELIMINARY POINT TEMPS/POPS...
Wichita-KICT 70 91 69 88 / 50 60 80 20
Hutchinson 69 90 67 88 / 40 80 80 20
Newton 69 89 67 87 / 30 70 80 20
ElDorado 69 88 68 86 / 40 50 70 30
Winfield-KWLD 69 90 70 88 / 40 30 60 40
Russell 68 86 64 88 / 30 70 70 10
Great Bend 68 87 64 88 / 30 80 70 10
Salina 70 89 68 89 / 20 80 80 20
McPherson 69 89 67 87 / 30 80 80 20
Coffeyville 70 89 72 89 / 30 20 50 50
Chanute 69 88 70 86 / 20 30 60 50
Iola 69 88 70 85 / 20 30 60 40
Parsons-KPPF 71 89 71 88 / 30 20 60 50
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
UPDATE...PJH
SHORT TERM...JMC
LONG TERM...JMC
AVIATION...PJH
Area Forecast Discussion...UPDATED
National Weather Service Lubbock TX
1027 PM CDT Sat Jun 23 2018
.UPDATE...
The thunderstorm activity that brushed the southern Rolling
Plains this evening has shifted to the south and east, so we`ve
lowered PoPs below mention for the remainder of the night.
&&
.PREV DISCUSSION... /issued 630 PM CDT Sat Jun 23 2018/
AVIATION...
Isolated to widely scattered thunderstorms currently developing
from southwest Oklahoma south-southwestward into the eastern
Permian Basin should remain south and east of the terminals this
evening. Even so, thunderstorms currently expanding in eastern
Colorado will likely form into a complex and track southeastward
into Oklahoma late tonight (early Sunday morning). Outflow from
these storms could briefly move through the terminals toward dawn
Sunday. If this happens a period of breezy northeasterly winds
will be possible, along with a threat for sub-VFR stratus. This is
far from certain, but certainly possible. Otherwise, relatively
light southeasterly winds this evening will yield to breezy
southerly winds Sunday afternoon, with VFR prevailing.
PREV DISCUSSION... /issued 250 PM CDT Sat Jun 23 2018/
DISCUSSION...
The cold front has drifted to our southern zones and is expected
to retreat northward later tonight as a surface low develops
across northeastern NM/southeastern CO ahead of an upper low that
will dig southward from MT. Models are hinting at some showers and
thunderstorms possibly developing along the Rolling Plains as the
front retreats. The likely area would be the southern Rolling
Plains as shown by the HRRR as the best convergence will be
located in that region of the FA. Surface winds will be out of the
south tomorrow ahead of another approaching front and will allow
highs to reach above the century mark. Monday will be almost 10
degrees cooler thanks to the front. The front will retreat late
Monday into early Tuesday as upper ridging begins to push into the
region. Models continue to show some convective development along
the front late Monday as it retreats and a shortwave moves over
the region. Given the small scale of the shortwave pops will
continue to be on the low end of mentionable.
Upper ridging will dominate the region from Tuesday into late week.
The GFS and ECMWF have started to line up on their weekend forecast
by having the upper ridge push eastward by Saturday while amplifying
an upper trough across the western CONUS. This may allow for the
weekend to be somewhat wet with dryline convection supplied by
Pacific moisture.
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
33
Area Forecast Discussion
National Weather Service Little Rock AR
908 PM CDT Sat Jun 23 2018
.UPDATE...
Latest subjective surface analysis indicates a boundary from near
Pine Bluff, then extending westward to near Atoka Oklahoma. A few
cells have attempted to develop along this feature during the
past 45 minutes. The boundary will move northward overnight, and
is expected to provide a focus for widely scattered convective
development overnight.
Also, will need to monitor MCS activity, currently developing
across the central high plains. Forecast storm motion vectors
indicate this activity will approach western sections towards
sunrise.
55
&&
.PREV DISCUSSION...(ISSUED 624 PM CDT Sat Jun 23 2018)
AVIATION...
As previously mentioned, forecasts of convective development are
complicated during the short term. A southerly surface wind
of <=9 kts will prevail during the second half of the forecast
period.
55
PREV DISCUSSION...(ISSUED 341 PM CDT Sat Jun 23 2018)
SYNOPSIS...
A complex forecast is evolving this afternoon, with the potential
for severe thunderstorms late this evening through the overnight
hours. While confidence in storms developing is low, if they do
materialize, damaging winds, isolated tornadoes, and torrential
rainfall will all be possible. The greatest risk appears to exist
across portions of central and northern Arkansas.
SHORT TERM...Today Through Monday
Unfortunately, concrete details pertaining to the forecast through
tomorrow morning remain elusive as a complex convective scenario
continues evolving. 19Z objective analysis highlights a favorable
synoptic pattern, characterized by broad mid-level troughing across
the central CONUS and surface troughing stretching from West TX
northeastward into southern OK. A belt of enhanced moisture at H850
stretches roughly west-to-east from the TX Panhandle to near
Memphis, TN and is generally juxtaposed with a broad area of deep
layer moisture flux convergence and lower boundary layer
confluent flow. Throughout the morning, light showers have
persisted where these subtle forcing mechanisms have been
favorably overlapped; although radar trends indicate a decrease in
precip over the last hour or so, likely due to dry air
entrainment near the OK/AR border.
At the surface, two fairly distinct boundaries were noted as of
early afternoon: a convectively-reinforced warm front stretching
from southwestern OK eastward into TN, and the aforementioned west-
to-east oriented confluence axis from western OK through central AR.
The overall PoP fields and severe risk are heavily predicated on how
these features evolve this afternoon, and this remains a major point
of contention with the going forecast. The current thinking has the
warm front gradually lifting north into central and perhaps northern
AR late this evening, after which the boundary should become quasi-
stationary and will act to focus any convection that manages to
develop.
An additional point of contention is the timing of an approaching
upper impulse noted on WV imagery. 19Z analysis places the impulse
across southern OK with the expectation it will eject across the
area this evening and overnight. The additional forcing it provides
could be enough to initiate convection, but it remains unclear how
favorable the timing of this approaching impulse will be with
respect to other key features, namely frontal timing/position.
Model guidance has offered little more than frustration so far
today, with the HRRR entirely out to lunch and questionable
consistency among other model solutions, although the going trend is
for less convective coverage or, more frustratingly, a failure for
convection to initiate. The NAM/NAMNEST have remained most insistent
in generating convection across west-central AR after 00Z this
evening, with storms overspreading northern AR in the 06-12Z time
frame. Other solutions have trended toward less convective coverage
or, more frustratingly, no convective initiation at all. Not ready
to wipe out PoPs altogether, so gave heavy preference to the RAP
given its relatively decent grasp on hourly trends. Incorporating
its solution with the remaining body of evidence yields lower-
confidence PoPs, initially across central AR, and shifting into
northern AR overnight. The timing and placement of PoPs was
generally tied to the position of the surface warm front as well as
a notable area of deformation and moisture axis aloft.
If convection can initiate, the overall environment will certainly
be supportive of severe storms overnight, with MLCAPE values on the
order of 3000 J/kg and over 1000 J/kg of DCAPE. Deep shear values
around 30 kts should promote minimal organization, although an
overall lack of significant kinematic support suggests any storms
that develop will be largely driven by cold pool dynamics. Damaging
winds appear to be the main threat, followed by the potential of an
isolated tornado, especially invof the warm front. Again, this is if
convection initiates in the first place. Confidence is low for
initiation, but high in severe potential if convection materializes.
As upper ridging begins building in later in the period, subsidence
will increase and precip chances will virtually disappear save for
far northwestern AR. Expect a warming trend through the end of the
period, with highs back in the low-to-mid 90s by Monday afternoon.
Lows will range from the low-to-mid 70s each night.
Cooper
LONG TERM...Monday Night Through Saturday
Models all in decent enough agreement that one model is not really
favored versus another. Models all agree in the general synoptic
pattern with the usual timing and strength differences that always
show up as the period progresses. Bottom line is all models are
showing a return to very warm and dry conditions across the CWA.
Period initiates with upper trough/upper low moving through the
central plains and broad ridging over the southeast CONUS. Strong
thunderstorms will be possible with this upper low Tuesday but it
looks like most will stay to the north of the state although a few
of them dropping onto far northern Arkansas can not be discounted.
Even after this upper system passes through, models continuously
generate convection Wednesday which again could skirt the northern
most counties.
Come Thursday and beyond, models all agree that upper level ridging
will build over the region. This will basically cut off any chance
of precipitation although a diurnally driven storm can never be
ruled out in this environment. High temperatures will soar into the
90s and its possible a couple of locations could see 100 degrees.
Heat related headlines may be needed as the week progresses.
Goudsward
&&
.LZK Watches/Warnings/Advisories...NONE.
&&
$$
Aviation...99
Area Forecast Discussion
National Weather Service Memphis TN
639 PM CDT Sat Jun 23 2018
.UPDATE...
Updated to include 00z aviation discussion.
&&
.PREV DISCUSSION... /issued 301 PM CDT Sat Jun 23 2018/
DISCUSSION...
Most of the region recovering from morning convection with cu
fields on satellite across the north and far south where the area
was untouched from precipitation. Temperatures still cool along
the Tennessee River with readings around 80F...hotter in the west
with near 90F temperatures in the southwest Delta. Winds were
breezy from the south in the wake of the morning storms as well.
Tricky next 24 hours with regards to convection timing. Latest HRRR
showing a few storms popping up early this evening over north
Mississippi that may train through the night with little to no
activity farther north until tomorrow. However...models from
yesterday and Thursday were in strong agreement of organized
convection sliding across the northern counties in the 06-12z
time frame. So have split the difference with 40-50 pops across
much of the region tonight. Temperatures tomorrow will be
near average. Storms may still be lingering across the north
tomorrow night where the midlevel westerlies remain strongest.
Monday through Wednesday...next shortwave to drop into the Plains
and evolve into an upper low is anticipated this period. The GFS
shows the entire Midsouth remaining in an active convective
swath...while the NAM and Euro focus storms in the north and
east with the southwest starting to heat up. Have leaned more
with this NAM and Euro consistency. Temperatures will range from
89F to the northeast to 95F in the southwest...with triple digit
heat indices building in. Heat advisories are possible for
portions of the area.
End of next week...both the GFS and Euro show the ridge building
even further over the Central States. Widespread mid 90`s will be
the rule with a few upper 90`s possible in the west. Heat indices
in the 103F-109F range...so heat advisories will be likely.
JAB
&&
.AVIATION...
00z TAF Cycle
VFR conditions are ongoing as all terminals have remained free of
any thunderstorm activity this afternoon and evening. A few storms
present near KTUP currently, so have kept VCTS prevailing until
midnight. Otherwise, models still hinting at a low stratus deck
developing overnight, bringing MVFR or lower ceilings to the
terminals. Also feel fog formation will be likely to reduce
visibility at KMKL and KTUP during the overnight and early morning
hours.
Another MCS will likely impact the region by late Sunday morning,
from west to east. Have handled this with VCTS currently, as
timing and exact coverage are near impossible to resolve, thus
extremely low confidence at this time. Regardless, VFR conditions
will return by late in the period. Winds will be from the SSW
throughout the majority of the period, generally less than 11
knots.
ZDM
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...None.
MO...None.
MS...None.
TN...None.
&&
$$
Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
754 PM CDT Sat Jun 23 2018
.UPDATE...
Issued at 722 PM CDT Sat Jun 23 2018
Updated to include 00z aviation discussion below.
&&
.SHORT TERM...(This evening through Sunday)
Issued at 239 PM CDT Sat Jun 23 2018
RAP h85 analysis has been depicting a pool of slightly higher
theta-e air across central MN, which is where we have seen some
isolated showers develop. The HRRR has has been showing this
activity much of the day and that combined with RAP h85 theta-e
forecasts supports this isolated activity continuing into the
evening, so have some low pops across central MN through 6z to
account for that.
Satellite and radar imagery both easily depict a shortwave over
central SoDak this afternoon. This feature will slide into western
MN and slowly shear out across southern MN Sunday. Precip has been
slow to develop to the east of this feature, so have really
slowed down the progression of PoPs into southwest MN tonight.
Tied arrival of chance pops on the movement a weak h5 vorticity
max the RAP brings out of SoDak and into western MN. The NMM,
though slow, probably is the CAM that is closest to what we are
currently thinking for precip evolution tonight.
Sunday, dewpoints will be a tick higher, with forecasting
soundings from the NAM/GFS showing 1000-1500 j/kg of largely
uncapped CAPE developing. Forcing wise, there is not much there,
so this looks to result in unorganized scattered convection. Like
today, Sunday will feature little shear and little in the way of a
severe threat. But, slow storm motion will result in some very
localized heavier precip amounts.
.LONG TERM...(Sunday night through Saturday)
Issued at 239 PM CDT Sat Jun 23 2018
The remainder of the week will see some progression of the large
scale upper air pattern during the first half of the week before
it gets bottled up toward the end of the period. The medium range
guidance is in fairly good agreement on the overall evolution of
the longwave features through the end of the week, with a bit more
disagreement by the end of next weekend. The somewhat split flow
currently over the central CONUS will become more phased by
midweek after we see a shortwave trough move through our area on
Tuesday and another passes by to our north Wednesday into early
Thursday. After that the western side of a very broad sub-tropic
ridge over the eastern US and western Atlantic will get pumped up
over the central US with troughing over the western US. This will
put us into what looks to be a potentially very busy period of
weather from late in the week into the first part of the July 4th
week. We should wind up hot and humid and will have forcing in
place just to our west in association with the upper trough. So,
could easily see a period of periodic MCSs moving through the
region as the surface frontal boundary and cooler/drier air
struggles to push east into the stubborn upper ridge.
We`ll have a good chance for some showers/thunderstorms across the
west Sunday night into early Monday, then eastward across the
remainder of the area Monday night through Tuesday as the
aforementioned southern stream shortwave trough moves through the
region and surface low moves northeast from the central Plains
across southern Minnesota. Widespread severe weather doesn`t
appear likely, but there may be enough instability and shear for a
few severe storms later Monday into Tuesday, particularly over
the southern and southeastern portion of the area. We should see a
break in precipitation chances Tuesday night and Wednesday as a
weak surface ridge builds into the area. The northern stream
shortwave trough moving by to our north later Wednesday and
Wednesday night could produce some precipitation in the northern
portion of the area, but most areas look to stay dry. After that,
we look to have recurring chances for showers/thunderstorms with
MCS passages from Thursday night through the remainder of the
forecast period as activity develops to our west and moves east
around the periphery of the upper ridge. At this point, it`s tough
to pin point too much for completely dry periods, but better than
one might expect at days 5-7 given better than typical agreement
in the guidance.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 722 PM CDT Sat Jun 23 2018
VFR conditions expected through Sunday morning with increasing
chances of showers and thunderstorms to follow going into Sunday
afternoon. A few isolated showers are possible in western MN this
evening but activity will become more organized overnight in far
SW MN then gradually spread east through central-southern MN
during the day and into western WI by the evening. Difficult to
run with anything other than VCSH at this point, since chances are
still around 30-40% and thunder chances are even less. So
confidence is fairly high of seeing showers/thunderstorms across
the region tomorrow but low confidence on exact timing/placement
of storms at this point. Low chances for fog overnight due to high
overcast expected across the area.
KMSP...Precip looks to hold off until at least midday, allowing
for more peak heating to tap into a moist/unstable atmosphere
which will spark showers/t-storms. Conditions may briefly drop
into MVFR/IFR should storms directly impact the terminal but VFR
will be most prevalent.
/OUTLOOK FOR KMSP/
Tue...MVFR possible. -SHRA/-TSRA likely. Wind SE bcmg NW 5-10
kts.
Wed...VFR. Winds NW 5-10 kts.
Thu...VFR. Winds SE 5-10 kts.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
&&
$$
UPDATE...JPC
SHORT TERM...
LONG TERM...MPG
AVIATION...JPC
Area Forecast Discussion
National Weather Service Blacksburg VA
946 PM EDT Sat Jun 23 2018
.SYNOPSIS...
Low pressure aloft over the Ohio Valley will lift northeast
tonight through Monday. High pressure aloft will build over the
eastern U.S. during the later half of the week. Much of the
upcoming week will feature warm and humid conditions with just
isolated to scattered mainly afternoon and evening showers and
thunderstorms.
&&
.NEAR TERM /THROUGH SUNDAY/...
As of 945 PM EDT Saturday...
No major updates with this forecast adjustment. Have only
tweaked hourly temperatures and dew points to reflect the latest
conditions and expected trends through midnight. Also, made
minor adjustments to the sky cover to reflect even less coverage
prior to the arrival of the activity currently making gradual
progress eastward through far southwest Virginia.
As of 645 PM EDT Saturday...
Very little remains in the way of showers across the region.
This trend should continue as we approach sunset and the loss of
the daytime heating. Additional showers will be possible later
this evening as a disturbance moves into eastern Tennessee. The
western quarter of the region may see isolated to scattered
showers after midnight through daybreak Sunday.
As of 300 PM EDT Saturday...
Water-vapor imagery shows a mid-level trough over the Ohio Valley
rotating eastward towards the Mid-Atlantic region this afternoon
into tonight. The upper low will lift out across the northeast U.S.
by Monday. SPC Mesoscale analysis at 18z showed that CAPEs have
rebounded top 1k to 2k J/Kg east of the Blue Ridge. Lis this
afternoon vary from minus one to minus three across eastern half of
our Forecast area. The HRRR and HiResW-ARW-east showed scattered
showers and thunderstorms developing this afternoon and moving east
across our region into tonight. The latest day one convective
outlook keeps a marginal threat of severe weather across eastern
portions of forecast area. There is a small window for an isolated
pulse severe thunderstorm in the east. However, the best instability
will be pooled across the coastal plain to our south and east. With
the loss of solar heating this evening expected scattered convection
to diminish and tapper off into tonight. Once again expect areas of
low clouds and fog to form overnight into Sunday morning. Low
temperatures tonight will range from around 60 degrees in the
mountains to around 70 degrees in the piedmont.
Quasi-zonal mid-level height regime will govern conditions aloft
across the East. Airmass should become moderately unstable which
should lead to the development of scattered showers and
thunderstorms Sunday afternoon. A couple of weak shortwave rotating
across our area should enhance thunderstorms formation. SPC does
have the far western portion of the CWA in a 5%/Marginal Risk of
severe weather on day two convective outlook, which seems
reasonable. High temperatures on Sunday will vary from the lower 70s
in the northwest mountains to the lower 90s in the piedmont.
/Confidence Levels/
Temperatures...High
Precipitation Chances... medium
Winds...Medium
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/...
As of 200 PM EDT Saturday...
Sunday afternoon and evening thunderstorms will gradually fade away
overnight as a weak front tracks across the region Sunday night into
Monday. Stable air behind the front will keep thunderstorms chances
low Monday, while temperatures will again warm above normal.
Temperatures Monday will range from the low to mid 80s west of the
Blue Ridge to near 90 east.
North to northeasterly flow Monday night into Tuesday will bring a
brief break from the heat as a wedge of high pressure skirts over
the Mid Atlantic states and south-central Appalachains. Temperatures
will range from the mid 70s to lower 80s west and low to mid 80s
east. The wedge will slowly erode over the mountains during the day
Tuesday as a cold front approaches from the west. Areas outside of
the wedge may see a few thunderstorms develop in the afternoon, then
fade during the evening hours. Areas that typically erode outside of
the wedge first are the Mountain Empire of southwest Virginia west
to the Bluefield-Richlands area. Greenbrier Valley may also come out
of the wedge late Tuesday, depending on if the front is still over
the Midwest or in the Ohio Valley. As the front continues to
approach the area Tuesday night, the wedge will erode over the
mountains, but remain entrenched across the foothills and piedmont
counties into Wednesday morning.
/Confidence Levels/
Temperatures - High
Precipitation Chances - Medium
Thunderstorm Chances - High
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
As of 220 PM EDT Saturday...
The GFS is quick to remove the wedge Wednesday morning, while the
ECM hangs on to it over the piedmont into the early afternoon. In
either case, scattered showers and thunderstorms will form over the
area as the wedge erodes, it is just a timing issue. As the front
tracks over the region Wednesday, more numerous showers and
thunderstorms will over take the area. The front stalls over the
piedmont overnight which may keep lingering showers in the area into
the early morning hours Thursday. The front is expected to move east
during the day Thursday with only an isolated chance for afternoon
thunderstorms in the afternoon. Temperatures Wednesday and Thursday
will run close to normal levels.
A heat dome of high pressure over the southern Plains early in the
week will move over the East Coast next weekend. Temperatures will
once again run warmer than normal, ranging from the mid 80s to lower
90s across the mountains and mid to upper 90s east. Scattered
thunderstorms are also expected to develop each afternoon and
evening.
/Confidence Levels/
Temperatures - Medium to High
Precipitation Chances - Low to Medium
Thunderstorm Chances - Low to Medium
&&
.AVIATION /02Z SUNDAY THROUGH THURSDAY/...
As of 730 PM EDT Saturday...
Isolated showers across the region are rapidly decreasing in
coverage and should continue to do so through sunset with the
loss of daytime heating. Additional showers are expected across
mainly the far western parts of the region after midnight as a
disturbances head east through Tennessee. Few ceilings exist
across the area, and those that are around are in the VFR range.
Ceilings will increase in coverage tonight, again with most
being VFR. Far western parts of the region may see areas of MVFR
ceilings. Patchy IFR/MVFR fog is possible late tonight into
early Sunday morning in the mountain and river valleys.
During Sunday, look for showers and storms to increase across
the entire region, especially in the afternoon, as low
instability increases once again thanks to surface heating and
an upper level disturbance will approach from the Ohio Valley.
As of 142 PM EDT Saturday...
VFR conditions prevail this afternoon with isolated MVFR
convection and low clouds. The entire forecast area is in the
warm sector as winds shift south-southwesterly.
Broad upper low over the Ohio Valley will continue to lift
northeast this afternoon into tonight with the best upper
support from this low also shifting north and east.
Weak disturbances tracking around the upper low in the
northwest flow and the moist, warm, unstable airmass
may trigger scattered showers and isolated thunderstorms.
Most taf sites will see a thunderstorm this afternoon,.
Any convection that passes across an airport is expected to
remain moving, with a brief period of heavy rain producing IFR
conditions.
With no real change in airmass, expect MVFR/IFR ceilings and
patchy fog to redevelop early Sunday morning across the region.
Morning low clouds and fog should lift by late sunday morning
return taf sites to VFR. Scattered MVFR showers and
thunderstorms will develop Sunday afternoon with best chances in
the west.
/Confidence Levels/
Ceilings...Medium
Visibilities...Medium
Wind...Medium to High
Thunderstorm Chances...Low to Medium
.Extended Aviation Discussion...
A cold front will finally sweep through the region by Sunday
night with improving mostly VFR conditions Monday and Tuesday.
Isolated to scattered MVFR showers and thunderstorms are
possible by Wednesday. Scattered MVFR convection continues
Thursday.
&&
.EQUIPMENT...
As of 338 PM EDT Saturday...
The NOAA weather radio transmitter in Hinton, West Virginia that
is WXM72 and broadcasting at a frequency of 162.425 MHz is off
the air. Parts are on order to repair the transmitter, but there
is no known time of restoration. We apologize for any
inconvenience.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...None.
NC...None.
WV...None.
&&
$$
SYNOPSIS...KK
NEAR TERM...DS/KK
SHORT TERM...RCS
LONG TERM...RCS
AVIATION...DS/KK/NF
EQUIPMENT...
Area Forecast Discussion
National Weather Service Springfield MO
655 PM CDT Sat Jun 23 2018
.SHORT TERM...(This evening through Sunday)
Issued at 302 PM CDT Sat Jun 23 2018
Overnight MCS skirted the area to the southwest across Oklahoma and
Arkansas. The main surface boundary now lays across southern
Oklahoma into central and southern Arkansas. This boundary will
slowly lift northward tonight and Additional storms may develop
within the frontal zone over Oklahoma and Arkansas during the
overnight period as the southerly low-level jet strengthens. Both
the NAM and NAMNest shows this, but the HRRR does not. Elevated
instability does increase overnight across far southern Missouri
as well. Did keep lower end probabilities to account for this
potential, but confidence not real high.
Depending upon what happen overnight, convection may linger into
Sunday morning across at least southern Missouri. Meanwhile, a
mid level low drops into western Nebraska intersecting the
westward extent of the warm front that will be lying across
northeast Kansas and northern Missouri by late afternoon. The warm
sector across Kansas will become quite unstable with MLCAPES
exceeding 4000 j/kg. Strong to severe convection likely to fire
and then progress eastward with time and continue into Sunday
evening with severe threat possible expanding eastward into
southeast Kansas and western Missouri late Sunday into Sunday
evening.
.LONG TERM...(Sunday Night through Saturday)
Issued at 302 PM CDT Sat Jun 23 2018
The entire system moves eastward on Monday, with surface cold front
setting up across eastern Kansas. Most unstable CAPES of 3000 j/kg
develop ahead of the front by afternoon, with the strongest deep
later shear closer to front over western into central and northern
Missouri. Give instability and shear will likely see the potential
for strong to severe storms by afternoon and into Monday evening.
Temperatures also look to be on the warm side, with highs in the
upper 80s to near 90.
It looks somewhat quiet but warm for Tuesday, with convective focus
north of the area. However, GFS showing the northern Missouri
convection developing into a southward moving MCS Tuesday night into
Wednesday morning.
Mainly quiet but hot weather is then expected from later Wednesday
all the way through Saturday. Upper ridge builds back across the
area and this will push temperatures back into the low to mid 90s
and heat indices back near 100 or slightly higher.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 654 PM CDT Sat Jun 23 2018
Pilots can expect VFR conditions to prevail at area terminals
tonight and Sunday. However the development of scattered storms
late tonight through Sunday will have to be monitored.
&&
.SGF WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&
$$
SHORT TERM...Raberding
LONG TERM...Raberding
AVIATION...Foster