Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 07/11/20
Area Forecast Discussion...Updated
National Weather Service Billings MT
849 PM MDT Fri Jul 10 2020
.UPDATE...
Updated the forecast to add a small chance of showers and
thunderstorms to the Beartooth/Absaroka Mountains and adjacent
foothills through midnight MDT tonight. Radar and satellite show
that a few showers and thunderstorms have developed over the
mountains and are moving east/northeastward over the foothills
before dissipating farther to the ENE. We think that with the lack
of upper air support, a drier air mass, and loss of solar
heating, these showers and storms should dissipate later this
evening. Otherwise just cleared out PoPs near the Dakota border
where activity has ended. Rest of forecast is in good shape. We`re
on track for a dry and very warm Saturday. RMS
&&
.DISCUSSION...
Tonight through Saturday Night...
Line of thunderstorms developed along and ahead of the cold front
this afternoon in an area of increasing vorticity advection from
the shortwave centered in N central MT. MLCAPE over SE MT was
1500-2000 j/kg and highest shear was over SE Carter County. Given
these parameters, supercells were not out of the question mainly
over Carter County. HRRR and EC Ensemble were handling the
situation well this afternoon and had precipitation exiting the
area by 00Z. This seemed reasonable given the line moving E at 30
to 40 mph. Thus went basically dry for tonight. Kept winds gusty
early in the evening. Upper ridging then builds over the area
tonight through Saturday night with dry weather and temps slightly
above normal. Arthur
Sunday through Friday...
Upper level ridge over the region on Sunday gets crashed by an
upper level trof moving into BC. Combination of warmest air aloft
and compressional warming ahead of a weak front will bring the
hottest day of the week with temperatures of 95-100 in many
locations though guidance has begun to slowly back off the
highest values a bit. Models indicate as a prefrontal trough
shifts east of the area some stronger winds aloft have a chance to
mix down so expect some gusty winds in the afternoon. The front
pushes through Sunday night and a few thunderstorms are possible
over southeast Montana.
The upper level trough slowly works across southern Canada Monday
through Thursday and this keeps a cooler west northwest flow over
the area with a mainly dry pattern. A few showers or
thunderstorms are possible as weak disturbances come through this
flow but does not look favorable for producing moisture.
Temperatures will be 10 degrees below normal for the early part of
the week before starting to warm on Friday. borsum
&&
.AVIATION...
VFR will prevail tonight. The Beartooth/Absaroka Mountains could
be obscured this evening in scattered showers and thunderstorms.
Showers could make it to the adjacent foothills and cause brief
MVFR conditions there. Shower/storm activity should dissipate by
06z Saturday. RMS
&&
.PRELIMINARY POINT TEMP/POPS...
Sat Sun Mon Tue Wed Thu Fri
-----------------------------------------------------------
BIL 058/089 060/095 060/080 054/081 055/083 057/085 059/087
00/U 01/U 11/B 22/W 11/U 22/T 22/T
LVM 050/088 054/089 053/078 047/079 048/082 050/084 051/085
00/U 01/U 11/B 21/U 11/U 23/T 33/T
HDN 055/090 060/097 059/081 054/082 054/085 057/087 058/089
00/U 00/U 11/B 22/W 11/U 11/B 22/W
MLS 055/085 060/096 060/080 054/081 055/083 057/085 059/087
00/U 01/U 21/B 32/W 11/U 21/B 22/W
4BQ 055/086 059/098 060/082 054/080 054/084 057/087 058/089
00/U 00/U 10/B 44/W 21/U 11/U 22/W
BHK 053/082 055/093 058/080 052/079 052/082 054/084 056/085
00/U 01/U 30/B 33/T 11/U 11/U 32/W
SHR 054/089 057/098 056/083 052/081 052/085 054/087 056/089
00/U 01/U 11/B 43/T 21/U 11/U 22/T
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...None.
WY...None.
&&
$$
weather.gov/billings
Area Forecast Discussion
National Weather Service Dodge City KS
554 PM CDT Fri Jul 10 2020
...Updated Aviation...
.SHORT TERM...(This evening through Saturday)
Issued at 203 PM CDT Fri Jul 10 2020
The main focus for the short term will be convective initiation
later today, if at all. A large area of stratus has been mixing out
through the day. An area of 850 mb warm advection was located over
south central Kansas where clouds have cleared out most efficiently
and allowed diabatic heating to ramp up, resulting in temperatures
reaching the upper 80s by noon. An inverted trough or outflow
boundary was from south central Kansas , nw to around hays. The
region located between the edge of this warm advection surge and
the boundary would be the general region of convection initiation
if the WRF-NMM model is right. The earlier run of the 4km NAM also
was producing afternoon convection but has also backed off. The HRRR
has just begin to begin to hint at convective initiation, but at
this point this afternoon is still unconvincing. If a storm can
become sustained, the supercell parameters are not bad with 35 knots
of bulk shear and at least 1500 j/kg of MLCAPE, assuming the CIN can
be eroded.
Next concern will be whether or not the stratus will redevelop
overnight. It looks like the best opportunity for stratus
redevelopment will be out west of highway 83 overnight, as points
east have too low of rh fields despite mainly a strong upslope flow
and component. There will be a little better convergence west of
Scott city and Garden City. Overnight lows can be far warmer across
the Pratt - Med Lodge areas (in the mid 70s) compared to mid 60s
forecast around Syracuse.
.LONG TERM...(Saturday night through Friday)
Issued at 203 PM CDT Fri Jul 10 2020
For day 2 on Saturday, a push of drier air will create light north
to northeast winds across central Kansas, reorienting the boundary
layer moisture from across western OK and far sw KS to eastern
Oklahoma for Sunday. Small chc pops are included for late day Sunday
and Sunday evening. likely initiating out in Colorado and moving in
late day. An 850 mb high shows up by Tuesday in the ECMWF over the
Dakotas which may increase moisture converge from the MissouriValley
into central Kansas. Other than that the extended period is one of
relatively low confidence in any widespread convective activity.
&&
.AVIATION...(For the 00Z TAFS through 00Z Saturday evening)
Issued at 554 PM CDT Fri Jul 10 2020
VFR is expected to continue through this TAF cycle. SKC is
expected to prevail overnight, with winds trending light and
variable. A dry cold front is expected to bring an abrupt
northerly wind shift to all airports around 12z Sat. Expect
N/NE winds to gust to near 30 kts after 15z Sat.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 71 95 66 95 / 10 10 10 10
GCK 69 95 64 96 / 10 10 10 10
EHA 71 97 67 98 / 0 10 10 10
LBL 70 100 66 99 / 10 0 10 0
HYS 72 92 64 91 / 10 10 10 10
P28 75 100 68 96 / 10 10 10 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Russell
LONG TERM...Russell
AVIATION...Turner
Area Forecast Discussion
National Weather Service Des Moines IA
918 PM CDT Fri Jul 10 2020
.UPDATE...
Issued at 918 PM CDT Fri Jul 10 2020
The big question this evening is the fate of two convective
clusters over NE and SD. The one along the NE/SD border is easily
the most significant at this point and should be the dominate
player for MO Valley weather later tonight. Effective inflow
along the 305-310K surfaces is not great, often 15-25kts, but the
associated moisture convergence is expected to intercept the MCS
over northeast NE with forward propagating Corfidi vectors
suggesting it would do no better than clipping southwest IA.
Have kept chance PoPs going overnight for the potential of cells
currently west of Aberdeen, which the forward propagating Corfidi
vectors would bring into central IA, but have concerns whether
this will have much support to mature further due to a lack of low
level convergence. It will be entering the persistent MUCAPE axis
however with moderate+ effective shear, so there is some
conditional strong to severe potential if it can mature somewhat.
&&
.DISCUSSION.../Tonight through Friday/
Issued at 259 PM CDT Fri Jul 10 2020
Overview...Primary concern in the near/short term will be storm
chances tonight and again on Saturday afternoon/evening. Beyond
this weekend, next chance for storms would come no earlier than
late Monday into perhaps the middle of next week. Drier and hotter
conditions are expected by late next week or next weekend.
Details...GOES-East upper level water vapor imagery shows a
shortwave trough moving across the western Dakotas late this
morning into this afternoon. Ahead of this shortwave,
thunderstorms have been moving eastward in the left-exit region of
a 105 knot, 250mb jet. This convection has waned, but has not
given up near the Nebraska border as of early afternoon. The area
of the western and central Dakotas is the area where strong
instability and high deep layer shear will develop by later this
afternoon allowing for additional storms to form as another
shortwave trough enters the Dakotas toward evening (see recently
issued MCD #1171). The storms should eventually grow upscale into
more than one mesoscale convective systems (MCS). Current guidance
suggests that the stronger of the two MCSs will follow the
instability gradient southeastward over eastern Nebraska and
western Iowa. This is supported by many convective allowing models
(CAMs) as well as most of the global models. The GFS is the
farther east among the global models bringing storm chances to
near I-35. Further, several runs of the HRRR this morning (13z,
17z) showed the MCS moving into central Iowa and other runs (6z,
12z, 15z) showed a weaker MCS passing through northern Iowa with a
strong MCS moving through eastern Nebraska/southwest Iowa after
6z tonight. 10/12z HREF have the bulk of updraft helicity tracks
going through eastern Nebraska and far western Iowa with a few
streaks toward or into north central Iowa. 16z SSCRAM (Statistical
Severe Convective Risk Assessment Model) also would seem to point
to eastern Nebraska/far western Iowa as being the main corridor
for severe risk with lower risk over northern Iowa.
All that stated, what can we expect? The most likely scenario at
this point will be a MCS with severe wind gusts moving through
eastern Nebraska and far western Iowa perhaps clipping our far
southwestern counties. It is possible that another MCS with mainly
sub-severe winds moves over northern Iowa late tonight a la the HRRR
and NAM. The less probable scenario is the stronger MCS moves
through northern to central Iowa with severe wind gusts.
After the overnight convection moves through early Saturday morning,
there should be a period of recovery assuming the unlikely scenario
does not play out. Another embedded shortwave in the northwest flow
will arrive by Saturday afternoon and should encounter by that time
an airmass characterized by MLCAPEs over 1000 J/kg with 0-6km shear
of around 35 to 40 knots. Primary storm mode with fairly straight
hodographs will be damaging wind gusts and hail as the storms move
southeastward over the northeastern third to half of the state.
In the wake of this shortwave trough, drier weather with seasonable
temperatures and lower humidity are expected on Sunday. The mid-
level ridge stretching from Texas into the southwestern US will be
suppressed some early next week as a longwave trough moves ashore
over British Columbia on Sunday and across the southern Canadian
provinces next week. A lead shortwave trough embedded in the
longwave trough with a surface boundary will move across the
northern states later Monday into Tuesday. This may bring some
chances of storms to the region with the highest chances over
northern Iowa into Minnesota later Monday into Monday night. With
Iowa on the periphery of the influence of the longwave trough, this
may foster additional storm chances into the middle of next week.
While current forecast does not veer away from the initial National
Blend of Models guidance given lack of clarity on a dry period
looking at a variety of global and ensemble models, there will
undoubtedly be periods of dry conditions. By late in the week, the
mid-level ridge will spread eastward over the south central into the
southeastern US and build poleward. This will result in increasing
temperatures and decreasing chances of storms as any shortwave
troughs will also move poleward. 850mb temperatures push into the
middle 20s Celsius by late next week into next weekend, which would
equate to highs well into the 90s to challenging the triple digits.
&&
.AVIATION.../For the 00Z TAFS through 00Z Saturday evening/
Issued at 650 PM CDT Fri Jul 10 2020
The primary concern will be convective trends, mainly overnight
and again Saturday afternoon. Initially confidence is high in VFR
conditions through the evening, but it begins to diminish into
Saturday. Clusters of thunderstorms will continue to move across
the Dakotas overnight, but there is still some uncertainty on
their eventual track. Have only included VFR VCSH wording at more
likely spots until trends become more clear. Additional storms are
likely to affect NE Iowa later Sat, and have added several hours
of VCTS there for a start where confidence is slightly higher, but
still not great.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
UPDATE...Small
DISCUSSION...Ansorge
AVIATION...Small
AREA FORECAST DISCUSSION
National Weather Service Kansas City/Pleasant Hill MO
1053 PM CDT Fri Jul 10 2020
.Discussion...
Issued at 308 PM CDT FRI JUL 10 2020
Forecast focus is on the MCS expected across western Missouri and
eastern Kansas late tonight/early Saturday morning.
Broad ridging in place across the northern Plains and Rockies. A
short wave trough currently traversing across the Montana High
Plains will be a contributor for convective development this
afternoon across the Dakotas. Convection will develop along the
northern reach of the elongated surface trough stretched across the
front range into the Black Hills. As convection evolves through the
evening and overnight across eastern Nebraska, the expectation is
for it to follow a traditional MCS like trajectory southward, riding
along the 1000-500mb thickness gradient into northeastern
Kansas/western Missouri. The CAMs have been rather consistent,
overall, with the HRRR handling the past few MCS rather well. There
is one big caveat in all of this, its the ongoing severe isolated
convection in central Nebraska this afternoon. This activity has not
been well captured by short range guidance, but continues to
maintain itself, supported by decent low level flow from the south
and stout surface based instability greater than 3000 J/Kg. This is
a tricky situation as this small cluster has left upper 50s and
lower 60s dew points in it`s wake. This could have implications for
tonight. On water vapor, the wave responsible for this afternoons
storms in the Dakotas and overnight tonight for KS/MO is still
there. The big question running through the next several hours will
be what is the impact of this cluster over central Nebraska.
If things pan out the way we anticipate, regardless of the current
ongoing activity, the overnight MCS will drop south out of eastern
Nebraska and moving into northeastern Kansas through 3 to 5 AM, with
remaining storms moving through eastern Kansas and western Missouri,
potentially the KC Metro by 5 to 7 AM. Strong to damaging wind would
be the greatest concerns.
&&
.Aviation...(For the 06Z TAFS through 06Z Saturday Night)
Issued at 1053 PM CDT FRI JUL 10 2020
Looks like VFR conditions will prevail for the next 24 hours.
Only issues will be around sunrise Saturday, as a complex of
thunderstorms shifts south across central Kansas, with a wind
shift to the north later in the morning.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
Discussion...Kurtz
Aviation...Cutter
Area Forecast Discussion
National Weather Service Grand Forks ND
1035 PM CDT Fri Jul 10 2020
.UPDATE...
Issued at 1024 PM CDT Fri Jul 10 2020
Made slight adjustments for precipitation timing with only light
precipitation expected through 06Z. After 06Z, scattered showers
and embedded thunderstorms are expected to work eastward through
at least sunrise. MUCAPE values will be in the 700 to 1500 J/Kg
range with modest shear available. A strong storm or two cannot be
ruled out, but widespread severe potential remains rather low.
UPDATE Issued at 646 PM CDT Fri Jul 10 2020
Latest CAMs and hi-res ensembles show thunderstorm activity
struggling to work eastward into the CWA later this evening. A few
stronger storms could make it into the southern portions of the
Devils Lake Basin, with the expectation that these storms would
become increasingly elevated over time. If storms are able to hold
together, hail upwards of one inch could remain a risk into the
early overnight hours. The time frame of most concern would be
between 05Z and 09Z.
&&
.SHORT TERM...(This afternoon through Saturday night)
Issued at 349 PM CDT Fri Jul 10 2020
Monitoring potential for isolated severe impacts this evening in our
far west roughly from Devils Lake to southeast ND. Confidence is
beginning to decrease that we will see any impacts, but it still
can`t be ruled out.
Influence of surface high has been keeping dryer more stable air
mass in place, with strong cap and limited instability (ML CAPE less
than 250 J/KG). RAP indicates minimal increases in our west. Main
forcing is still west west over Montana and timing of this wave is
favored for later tonight, lowering confidence that we would see
initiation locally. That means we are dependent on activity
developing into western ND holding together as it moves eastward
towards our CWA after 03Z. At that point parameters may not become
as favorable, though elevated instability around 1500 J/KG and
effective shear 30-35kt may support a strong to marginally severe
storm in that narrow corridor of our west for a brief period. HREF
has shown UH tracks remaining west/southwest and consensus of latest
short range CAMs barely shows any activity making into our
southwest. Overall, not a lot of confidence that instability will be
high enough for long enough before loss of daylight/stabilization
takes place.
Late tonight-Saturday night: With mid-upper level shortwave trough
passage and linger surface trough axis we may actually see better
chances for pockets of showers/thunderstorms late tonight into the
morning and then diurnally driven thunderstorms Saturday. ML CAPE
generally less than 1500 J/KG with weak shear (0-6km 20kt or less)
and decreasing forcing lowers confidence in more that diurnal pulse
type sub-severe convection midday Saturday into Saturday afternoon
(dry Saturday night with increasing subsidence/stability).
.LONG TERM...(Sunday through Friday)
Issued at 349 PM CDT Fri Jul 10 2020
Main focus still on severe thunderstorm potential Monday and Monday
night, with all severe modes possible depending on timing/evolution
of pattern.
Large scale pattern dominated by quasi-zonal progressive flow, with
most waves less defined, but a good signal for strong mid-upper
trough passage Monday-Monday night highlighting one period of higher
confidence where there is a stronger consensus from NBM/GEFS QPF over
our CWA. Temperatures trends will tend to remain near or a little
lower than seasonal averages (highs generally upper 70s to mid 80s).
Regarding severe potential Monday: Strong negatively tilted trough
is shown to progress across the Norther Plains during the day and
evening Monday rounding an upper low over Canada, with a more
defined cold front passage Monday night. Strong shear profiles and
moderate to potentially high CAPE could support discrete storm
development or upscale growth into a stronger organized MCS that
would then transition east if things line up correctly. The window
for better WAA/instability is narrower with this system though, and
at this range it is hard to know ultimately how the finer
details/smaller scale surface features line up that would impact
evolution of any severe threat.
&&
.AVIATION...(For the 06Z TAFS through 06Z Saturday night)
Issued at 1024 PM CDT Fri Jul 10 2020
VFR conditions prevail this evening with mid-level clouds
remaining persistent across the area. Showers and thunderstorms
will gradually work eastward into the KDVL region during the
overnight with this activity eventually moving into the vicinity
of the Red River Valley as sunrise approaches. While a few strong
storms and higher CB are possible, mainly embedded thunderstorms
are expected. For Saturday, additional diurnal convection is
possible through the day.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...None.
MN...None.
$$
UPDATE...Lynch
SHORT TERM...DJR
LONG TERM...DJR
AVIATION...Lynch
Area Forecast Discussion
National Weather Service Wichita KS
849 PM CDT Fri Jul 10 2020
.MESOSCALE DISCUSSION...
Issued at 847 PM CDT Fri Jul 10 2020
The cluster of storms that raced south across Nebraska has ran
into a more stable airmass over Kansas and also lost daytime
heating. Therefore expect things to remain quiet across Kansas
until the late night hours. Latest meso-analysis shows low-level
jet/moisture transport feeding complex of storms over northern
Nebraska. The low-level jet/moisture transport will lead this
complex of storms southeastward across Nebraska into eastern
Kansas for late tonight/Saturday morning. The areas greatest at
risk for severe weather will be for locations east of a Salina to
Wichita line. Damaging winds and torrential downpours would be the
main hazards.
-Jakub
&&
.SHORT TERM...(This evening through Saturday night)
Issued at 334 PM CDT Fri Jul 10 2020
This afternoon, upper level ridging remains established over the
Desert Southwest, with fast west/northwest flow aloft from the
central/northern Rockies into the central/northern Plains. Within
that flow exists a prominent s/w trough moving through Montana,
with convection beginning to develop across the NRN High Plains.
Elsewhere, a broad zone of WAA exists in the lee of the Rockies
from Nebraska south into Oklahoma. Within this zone, a couple of
clusters of convection are ongoing (one over northern Nebraska and
the other over southern Oklahoma).
Like yesterday, visible satellite imagery and SPC meso data appears
to show a mid-level baroclinic zone from the OK MCS northwest
through central KS and into central Nebraska. With continued WAA
through the day and into this evening, a narrow zone of
showers/storms may fester during that time. Some short-term
guidance try to develop some deeper convection along that
baroclinic zone this afternoon, but thinking warm low/mid level
temps and a more overturned airmass (in the wake of the early
morning MCS) will tend to keep a lid on deeper convection locally
in the very near term.
Late tonight into Saturday morning, it is likely that one or more
convective complexes will traverse the Central Plains/Midwest/Ozarks
regions from northwest to southeast. Recent MCS` have generally
followed the 12-14C 700mb temp line/mid-level baroclinic zone
(mentioned above). That said, some subtle mid-level warming seems
plausible tonight as the NRN Rockies wave moves across the NRN
Plains and into the Midwest. Additionally, as the LLJ develops,
the nose of the stronger elevated moisture transport may tend to
be focused a bit more north and east compared to last night. In
general, the thinking is that the above-mentioned factors will
keep the bulk of the MCS activity focused across the eastern third
of Kansas. One potential caveat is the ongoing convection across
north- central KS. The HRRR (which has performed well of late)
continues to insist that convection will diminish. However, strong
heating/destabilization downstream of that area may support some
semblance of that activity continuing well into the
afternoon/evening as it propagates SSE. That activity seems to be
rooted more along the mid-level baroclinic zone that resides
across central KS/NE. Should that convection continue, it may
survive into parts of KS, with maintenance possibly aided as the
LLJ develops this evening. I left some pops in this evening to
account for this potential.
Otherwise, the focus will remain on convection developing across the
NRN Plains, and what trajectory it takes. Model guidance is
highly varied (ranging from an MCS moving from Nebraska into Iowa
and completely missing Kansas, to something diving more southward
through central/eastern Kansas). We`ll keep the higher pops
focused across eastern Kansas for now, but leave the door open
further west (ie. along the mid-level baroclinic zone). Wherever
convection tracks, damaging winds, sporadic instances of hail, and
very heavy rain/flooding should be the primary threats.
During the afternoon hours Saturday, a SFC trough/cold front will
push southeast across central/eastern Kansas. If an MCS dives
southeast through eastern Kansas, then the front will probably
come through with little fanfare. However, if tonight`s
convection stays east of Kansas, then there may be a window for a
few storms to develop across SRN KS during peak heating ahead of
the front.
Martin
.LONG TERM...(Sunday through Friday)
Issued at 334 PM CDT Fri Jul 10 2020
Models continue to insist that the Southwestern US ridge will expand
east across much of the southern US next week. While the trend has
been to focus the center of the ridge a bit further south, we
won`t escape the building heat. Temperatures should warm well
into the 90s, with 100s likely for some. Continued southerly low-
level flow will keep higher dewpoints/humidity in place, with
dangerous heat likely for parts of the area, especially eastern
Kansas. The mid and upper level jet should remain just north of
the area, but embedded waves may provide a glancing blow at times
with isolated to scattered convection possible (mainly northern
Kansas).
Martin
&&
.AVIATION...(For the 00Z TAFS through 00Z Saturday evening)
Issued at 617 PM CDT Fri Jul 10 2020
VFR conditions will prevail for all TAF sites across
central/southern Kansas through the evening hours. Thunderstorms
in Nebraska are expected to move southeast during the night time
hours, and could affect CNU very late tonight. Otherwise winds
will switch around to the east then north as a cold front pushes
southward across the region during the day on Saturday.
&&
.HYDROLOGY...
Issued at 334 PM CDT Fri Jul 10 2020
Another MCS may impact portions of central or eastern Kansas later
tonight through Saturday morning. There remains quite a bit of
uncertainty regarding the track of any thunderstorm complexes
during this time. The general idea is that the heaviest rain will
be focused over eastern Kansas. Flash flood guidance is around
2-3" in a 3 hour period. Should an MCS impact parts of the area,
there would certainly be the potential for some heavier rainfall
rates and, at least, minor flooding.
Martin
&&
.PRELIMINARY POINT TEMPS/POPS...
Wichita-KICT 70 94 68 92 / 20 20 0 0
Hutchinson 71 92 66 91 / 30 10 0 0
Newton 72 91 67 90 / 30 30 0 0
ElDorado 72 91 67 90 / 30 30 0 0
Winfield-KWLD 71 95 68 93 / 20 30 10 0
Russell 72 90 64 91 / 20 10 0 10
Great Bend 71 91 65 91 / 10 10 0 10
Salina 74 90 66 91 / 40 20 0 0
McPherson 72 90 65 90 / 40 20 0 0
Coffeyville 70 92 70 91 / 30 50 10 0
Chanute 72 89 68 90 / 40 50 10 0
Iola 72 89 67 90 / 40 50 10 0
Parsons-KPPF 71 91 69 90 / 30 50 10 0
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
MESOSCALE...CDJ
SHORT TERM...RM
LONG TERM...RM
AVIATION...CDJ
HYDROLOGY...RM
Area Forecast Discussion
National Weather Service Wilmington NC
859 PM EDT Fri Jul 10 2020
.SYNOPSIS...
A weak front will move eastward into the Coastal Carolinas
tonight, stalling nearby, before another weak front reaches the
area on Monday. Bermuda high pressure will dominate the middle
and late part of the week.
&&
.UPDATE...
Updated PoP/Wx forecast grids to increase t-storm chances across
the upper Pee Dee region over the next couple of hours. The last
several HRRR runs indicate there may be a better potential for
the convective activity to survive east of I-95 than I earlier
thought, perhaps even approaching the coast by 2-3 AM.
&&
.NEAR TERM /THROUGH SATURDAY NIGHT/...
Fay is approaching the Jersey Shore this afternoon while its
trailing trough lingers off the Carolina coast. Convection has
remained isolated thus far, but some increase in coverage is
expected primarily across the SC areas later this afternoon and
evening. Overall, storms will diminish with the loss of heating
later this evening but are expected to develop again during
Saturday. The focus Saturday will be the sea breeze front and a
weakening surface trough approaching from the west also aided by a
mid/upper trough. The Heat Index will increase tomorrow but is
expected to remain in the 100-104 range, or just below Heat Advisory
criteria. Regardless, the heat/humidity will make it uncomfortable
for those outdoors, especially Saturday afternoon.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
Hot weather will continue through early next week. Temps will
soar into the 90s. Slightly drier air should work its way into
extreme western portions of forecast area through early Sun,
but overall, a humid air mass will remain in place with heat
index values just above 100 in many spots Sun and Mon aftn.
Subsidence and drier air through the mid levels behind exiting
shortwave should inhibit convective activity on Sunday, although
a weak trough will remain over area and may remain focus for
iso convective development. May also see a pop up along sea
breeze front Sun aftn. Another shortwave and weak front will
approach late Sun into Mon with increasing southerly flow ahead
of it. Models show more in the way of mid to high clouds moving
through Mon aftn than convection and looks like best chc may
come late Mon into Mon night. Overall, do not expect much in
the way of shwrs/tstms early next week.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
Mid to upper trough will shift off the coast on Tues as mid to
upper level ridge builds in behind it. Sfc high will build in
from the north, but looks like boundary may linger and remain
focus for convection along with sea breeze front through mid
week. Bermuda high pressure will dominate the weather by mid to
late week. The upper levels should act to limit convection and
thunderstorms through the week, though, as ridge builds across
the Southeast, but GFS is hinting at trough pushing far enough
east on Fri to increase convection. Too far out to tell with
much certainty. Hot and humid weather will continue through much
of the week with temps typical of summertime and heat index
values around 100.
&&
.AVIATION /01Z SATURDAY THROUGH WEDNESDAY/...
VFR conditions are expected to continue throughout the next 24
with two possible exceptions.
1: Scattered showers/t-storms moving eastward from the
mountains and foothills could affect the FLO airport between
02Z and 05Z tonight. Potential is low, however brief MVFR/IFR
visibility is possible in heavy rainfall.
2: New convection will develop Saturday afternoon along the
seabreeze front at the coast. Best potential (30 percent) for
impact on an airport is expected at ILM and MYR where brief MVFR
to IFR visibility is possible. A 20 percent chance or less is
expected elsewhere.
Extended Outlook...Diurnal convection will continue, especially
near the coast, with brief MVFR to IFR conditions expected
through the weekend. Increased risk of flight restrictions on
Monday, before seeing more of a VFR trend through mid next week.
&&
.MARINE...
Trailing surface trough in the wake of Fay will weaken across the
adjacent Atlantic waters as another trough moves into the
Carolinas and stalls through Saturday night. Southwesterly flow
will prevail across the coastal waters with the new trough
becoming situated to the west. Speeds around 10 knots are
expected initially then temporarily increasing to around 15
knots, especially across the outer coastal waters, by later
Saturday afternoon and evening. As the trough nudges closer to
the waters very late Saturday night winds speeds should drop
back down to around 10 knots or less. Seas will be 2 to 3 ft
tonight into Saturday then increase during the late afternoon
and evening. Seas will begin to subside again very late Saturday
night as the winds diminish.
Approach of weak front or trough from the west late Sun into
Mon should kick up southerly winds up to 15 kts or so. This will
combine with slightly longer period SE-S swell up to 8 sec to
push seas up to 3 to 5 ft and around 5 to 6 ft, mainly in the
outer waters off NC coast, where Small Craft Advisory conditions
may occur. Bermuda high pressure will dominate the local waters
through much of the rest of the week with southerly winds
around 10 kts or so and slightly longer period SE to S swell
mixing in. Winds and seas will spike up a bit each aftn near
shore in sea breeze.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...None.
NC...None.
MARINE...None.
&&
$$
SYNOPSIS...ILM
UPDATE...TRA
NEAR TERM...SRP
SHORT TERM...RGZ
LONG TERM...RGZ
AVIATION...TRA
MARINE...RGZ/SRP
Updated for 00Z Aviation Forecast Discussion below.
PREV DISCUSSION... /issued 353 PM CDT Fri Jul 10 2020/
DISCUSSION...
A hot and dry afternoon across the Mid-South for the first time
in awhile. Latest GOES east visible imagery shows a mature MCS
near the ArkLaTex, with associated high cirrus spilling into the
Mid-South from the west. Temperatures range from the upper 80s
across the north to lower 90s further south. Heat index values
have remained at 100 or below for much of the day. Northwest
winds have advected in a slightly drier airmass across the north,
characterized by upper 60s dewpoints. This drier airmass will
allow areas across west Tennessee and northeast Mississippi to
fall into the mid to upper 60s overnight. Further west, including
the Memphis Metro, lows will likely stay in the lower 70s.
By late tonight, a MCS is forecast to develop over Missouri and
track SSE into the Lower Mississippi Valley by late tomorrow
morning. CAMs are still struggling with the exact location of this
system as it translates downstream in to our area. Nonetheless,
have latched onto the HRRR`s general location and timing of the
system for this package. It appears that an MCV or remnant outflow
will move into northeast Arkansas as early as 11AM tomorrow and
push through the area through the afternoon hours. The instability
mass field will vary greatly tomorrow afternoon, as drier air
will still reside over portions of west TN and NE MS. However,
along and west of the MS River, a hefty amount of CAPE will exist.
Values may exceed 3000 J/kg of SBCAPE. Storm mode will be outflow
dominant clusters, as only 20 kts of shear will be on hand. If an
organized cold pool can maintain, a more widespread risk of
damaging winds can be expected.
The Mid-South will remain in northwest flow again tomorrow night.
The 18Z HRRR depicts another MCS lining up behind the afternoon
convection tomorrow evening. This system will also have the
ability to produce instances of damaging winds, if it materializes
and pushes through our area. All models suggest this solution, but
timing will still need to be sorted out for this period.
Nonetheless, will add the mention of strong to severe
thunderstorms to the HWO for both Saturday and Sunday.
The forecast is still on track for a July heatwave next week. The
expansive ridge out west will begin to build into the region
early next week. Right now, Monday looks to remain the coolest day
with highs only in the lower 90s. However, the ridge axis will
become nearly centered over the Lower Mississippi Valley by
midweek. Preliminary blended guidance suggests highs in the upper
90s to possibly 100F Wednesday through Friday next week. The
combination of highs in the upper 90s and dewpoints in the low to
mid 70s, will yield heat index values in excess of 105F. Heat
advisories will likely be needed for several days. Guidance
trends will need to be watched for Excessive Heat.
Some weakening of the ridge is possible by next weekend, which
could break the streak of excessive heat. Stay tuned.
AC3
&&
.AVIATION...
00Z TAFs
Few aviation weather issues tonight, with light winds and VFR
prevailing. Main concern remains potential for TSRA arriving from
the northwest Saturday afternoon, around the perimeter of the
southwest U.S. upper ridge. Model consensus suggests JBR under a
more direct path of the TSRA, with MEM along the perimeter in
slightly drier air.
PWB
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...None.
MO...None.
MS...None.
TN...None.
&&
$$
...Updated Aviation Forecast Discussion...
.DISCUSSION...
Issued at 317 PM CDT Fri Jul 10 2020
Forecast Summary:
A good chance for thunderstorms, some potentially severe, remains in
the forecast for tonight. Beyond that, a series of shortwaves
rolling through generally westerly flow in the Plains will bring off-
and-on thunderstorm chances through much of next week.
Tonight through Saturday:
Northwest mid level flow remained over eastern Nebraska and western
Iowa today, along northeast quadrant of high pressure centered over
New Mexico. A subtle shortwave was noted rippling through central
South Dakota which had spawned scattered convection there and in
north central Nebraska. Convective inhibition to the east of this
activity had squelched eastward push, with only showers remaining
over northeast Nebraska. HRRR had shown this evolution with morning
runs.
A second and more prominent shortwave was pushing into eastern
Montana, and was triggering convection there as of mid afternoon.
This activity is expected to increase in intensity this afternoon
and evening as it begins a turn to the southeast. This may offer our
best opportunity for severe in our area, but will likely arrive
after midnight.
Short-range convection-allowing models have been all over the place
in regards to evolution of storms this evening and tonight. One
thing in common is them showing a broken line of wind-producing
storms diving southeast through our CWA, but timing into our area is
varied from early evening to after midnight. Given current
convective trends, expect a later arrival of storms from the western
Dakotas. Cold pool development in high instability environment is
indicated by various models, so damaging winds may accompany any
activity overnight.
Another potential for severe is this evening as north central
Nebraska storms continue to bubble up and expand south and east as
capping gradually weakens. Cumulus field has expanded in central
Nebraska where steep mid level lapse rates, MLCAPE near 3000 J/kg,
and effective shear near 50kt resides. Will have to watch this
activity this evening for potential development. If storms do fire,
large hail and damaging winds will be the main hazards with
supercellular storms, and mainly affecting areas west of a Norfolk
to Lincoln line.
Any convection should be exiting to the southeast of our area
Saturday morning, though some lingering instability is forecast to
lag behind line keeping chance for a few showers or storms to remain
in the area through noon or so. Decreasing clouds and temperatures
rebounding into the mid and upper 80s should follow.
Sunday through Friday:
We appear to be getting back to a pattern that will favor periodic
thunderstorm chances through the week. Mid level high pressure
will remain suppressed to our south as mid level low spins
through central Canada. This keeps much of Nebraska and Iowa under
influence of westerly mid level flow, with occasional shortwaves
agitating environment to trigger storms from time to time.
There appears to be some agreement between ECMWF and GFS that a
strong shortwave rotating through the Northern Plains will drive a
cold front into our area Monday night, bringing a decent chance for
thunderstorms then. Wednesday also offers some overlap between
models showing convection in our south. Otherwise we will likely see
at least small chances for storms each day, with temperatures close
to mid-July normals.
&&
.AVIATION...(For the 00Z TAFS through 00Z Saturday evening)
Issued at 643 PM CDT Fri Jul 10 2020
VFR conditions with light winds, unrestricted visibility and
SCT-OVC AOA 7,000 ft AGL should continue through 05Z Saturday.
After 05Z Saturday, the potential for thunderstorms will be
increasing across the region from northwest to southeast. Any
storms between 05Z and 13Z Saturday may produce damaging winds
and/or large hail. As always, strong LLWS, up/downdrafts and near
zero visibility are possible with the strongest storms.
Confidence in storm timing and coverage for the TAFs is low.
Suffice it to say, any of the TAF sites (KOMA, KLNK and KOFK) may
be impacted overnight. Skies should clear after 13Z Saturday,
leaving VFR conditions and breezy north winds (sustained 10 to 18
mph with gusts 20 to 30 kt) Saturday afternoon.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...None.
IA...None.
&&
$$
DISCUSSION...Dergan
AVIATION...Albright
...Update to aviation forecast discussion...
.SHORT TERM...(This evening through Saturday)
Issued at 357 PM CDT Fri Jul 10 2020
Main focus for this forecast package has been on the thunderstorm
potential late tonight into tomorrow morning. The shortwave that
will be the driver of this convection is still in eastern MT/WY and
is progged to move southeast through the Dakotas and NE. Plenty of
variability still exists across the CAM solutions with respect to
timing and track of the resulting clusters of storms as they develop
in the Dakotas and NE and progress southeast. Morning CAMs had been
showing convection developing ahead of the main line associated with
the shortwave, perhaps generating along an outflow boundary,
suggesting the potential for multiple rounds to move through the
area overnight. Most recent runs of the HRRR, NamNest, GFS, NAM, and
ECMWF have all showed a slower trend and as such, have delayed PoPs
this evening with the bulk of the activity forecast between 06-12Z,
perhaps closer to sunrise Saturday morning. While the greatest
likelihood continues to be in the northeastern CWA east of a
Marysville to Emporia line (rounding the edge of the upper ridge),
cannot rule out expansion of storms further west as has been
indicated with multiple rounds and uncertainty of how these clusters
may interact. With CAPE between 2500-3500 J/kg and effective shear
between 40-50 kts, there appears to be no reason to believe the
storms wouldn`t sustain themselves as they dive south from NE, with
the primary threats being damaging winds and locally heavy rainfall.
Perhaps the biggest caveat to this forecast is the ongoing
convection in northern/central NE. The HRRR currently suggests this
will weaken and the 18Z NamNest isn`t picking up on it at all, so
overall confidence in how short-term models are handling this is
low. Will need to monitor this to see if it maintains itself and
reaches northern KS earlier this evening.
Thunderstorms look to linger across the area through at least part
of the morning hours, but drying conditions are expected into the
afternoon. Have trended highs slightly cooler in far northeast KS
due to the morning activity, and depending on how long clouds/rain
linger, could see cooler temperatures overall. But as it stands,
highs are forecast to be in the mid 80s toward the KS/NE border to
the low 90s further south.
.LONG TERM...(Saturday night through Friday)
Issued at 357 PM CDT Fri Jul 10 2020
Heading into next week, the upper ridge remains nearly stationary
over the southwestern US with northwest flow over the CWA. Another
shortwave passes through Monday night into Tuesday followed by a
frontal boundary on Tuesday night into Wednesday, which looks to
hang around the area with weak disturbances within the flow. Only
have low-end chances each day at this point with changes likely to
come this far out. Otherwise, heat continues to be the story with
temperatures warming back into the 90s across the area and heat
indices into the low 100s as we round out the week.
&&
.AVIATION...(For the 00Z TAFS through 00Z Saturday evening)
Issued at 639 PM CDT Fri Jul 10 2020
There remains uncertainty if a thunderstorms complex will affect
the terminals through the early morning hours of Saturday. Some of
the short-term model guidance shows the complex weakening as it
moves southeast across eastern NE, and may remain north and
northeast of the KTOP and KFOE terminals. The small complex of
storms near Kearney, NE will remain west of KMHK through the
evening hours. An outflow boundary will move southwest across the
terminals towards 11Z and switch winds to the northeast...again
if a complex of storms build south across the terminals, then the
northeast winds may be gusty from 11Z SAT through 15Z SAT.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Picha
LONG TERM...Picha
AVIATION...Gargan