Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 09/16/16
Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
823 PM CDT THU SEP 15 2016
.UPDATE...
Issued at 823 PM CDT THU SEP 15 2016
Radars showing shower/storm development out west this evening with
a short wave trough kicking northeast across South Dakota through
the night. Latest HRRR model was showing decent shower development
with this short wave as it lifts northeast. Have adjusted pops a
little and may have to also increase them some yet this evening.
UPDATE Issued at 645 PM CDT THU SEP 15 2016
00z aviation discussion updated below.
&&
.SHORT TERM...(This Evening through Saturday Night)
Issued at 1231 PM CDT THU SEP 15 2016
Short term fcst models having a difficult time with the ongoing
precip to our southeast, keeping it too far west. This is having an
impact on our severe weather chances for the rest of the afternoon,
which should stay mainly to our east. The 17Z weather map indicated
the sfc low set up between southwestern ND through
Stanley/Sully/Hughes Counties of SD. The 500MB low is still spinning
over WY and eastern MT. We will continue to see waves rotating
around the low as it moves into western ND by 00Z this evening,
while the sfc low moves across the central portions of our forecast
area. The sfc low will deepen/become better organized across eastern
ND as we move into the late evening and overnight hours, with the
cold front sliding to the eastern third of the cwa by 06Z Friday.
While the cold front exits east pretty quickly Friday morning,
chances for showers and even a few thunderstorms will remain as the
500MB low moves over eastern ND 15-18Z Friday. By mid afternoon,
light showers will be either gone, or just over the northeastern
counties. Dry weather should then be the rule through Saturday. All
this dry air will spell a return of lower dewpoints/RH Saturday
afternoon. RH values west river on Saturday could bottom out 25-30
percent. This will be accompanied by southwesterly winds of 10-15kts
with good mixing anticipated.
.LONG TERM...(Sunday through Thursday)
Issued at 1231 PM CDT THU SEP 15 2016
The long term continues to look mostly dry with zonal flow aloft.
Only weak sfc flow until Wednesday will keep forcing and moisture to
a minimum. On Wednesday a low will move across South Dakota and may
bring the only chances for precip, mainly to the eastern cwa.
Temperatures will be above average for most of the period with highs
in the upper 70s to lower 80s. Cloud cover and cool air advection on
Wed and Thu will push temps back to around average with highs near
70.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday Evening)
Issued at 645 PM CDT THU SEP 15 2016
A few showers and storms will lift northeast across the region
tonight and may affect the airports at or in the vicinity.
Otherwise, after the ifr ceilings move out of ATY this evening,
conditions should be mainly vfr through Friday at all locations.
There will be some wrap around stratus clouds later tonight and
Friday mainly affecting MBG and ABR. They may be mvfr for a time.
&&
.ABR Watches/Warnings/Advisories...
SD...NONE.
MN...NONE.
&&
$$
UPDATE...Mohr
SHORT TERM...KF
LONG TERM...Wise
AVIATION...Mohr
Area Forecast Discussion
National Weather Service La Crosse WI
630 PM CDT Thu Sep 15 2016
.SHORT TERM...(Tonight through Friday Night)
Issued at 145 PM CDT Thu Sep 15 2016
Deep/vigorous closed low and trough over the entering the Northern
Plains from MT/WY per latest water vapor imagery/RAP 500mb analysis.
Southwest flow ahead of this trough with embedded weak shortwave
activity was interacting with higher precipitable water
values/CAPE...producing some thunderstorm activity across
southwestern MN. Weaker showers were popping out ahead of
this...west of the Mississippi River on eastern fringe of increasing
850mb moisture transport. Otherwise...temperatures this afternoon
across the local area were hovering near seasonal normals in the
70s.
For tonight...latest HRRR convective allowing model....which was
handling convection best across southwest MN...take this complex of
storms and marches it into southeast MN/northeast IA by early this
evening and then across the rest of the area later this
evening/overnight. Latest RAP/NAM showing respectable amount of
CAPE in the 1000-1500J/kg range mainly south of I-90 but bulk shear
was lacking...generally hovering in the 20-25kt range. Thinking we
could see mainly pulse type/multicellular mode storms with a few of
the stronger storms capable of producing some sub-severe hail and
wind gusts. With higher precipitable water values increasing into to
around 1.5 inches...these storms will also be capable of heavier
rainfall. Not anticipating any flooding threat as these storms will
be fairly progressive in nature.
Mid-level low/trough pushes a cold front through the area Friday but
with ongoing convection/cloud cover/less cape and lack of good
convergence along the front and mid-level pv forcing heading north
of the area...not anticipating any severe threat. Main threat again
would be some heavier downpours and localized gusty winds.
A few lingering showers/isolated storms still possible mainly east
of the Mississippi River Friday evening...but then convection
expected to clear the area after midnight.
.LONG TERM...(Saturday through Thursday)
Issued at 145 PM CDT Thu Sep 15 2016
Cooler/drier air overspreads the area on Saturday. Given cyclonic
mid-level flow/cooler air aloft...expecting a fair amount of cumulus
development...mainly along/north of I-94. Also kept a small chance
of showers across Taylor county in north central WI. Look for highs
ranging from the upper 60s to the lower 70s.
Ridge of high pressure will provide a pleasant Sunday with highs
topping off in the 70s.
High-zonal mid-level flow will bring a trough across the Northern
Plains Sunday night with warm air advection taking place into our
area. Latest GFS/ECMWF showing some hint of light shower activity
pushing in...but not expecting anymore than isolated coverage.
A cold front slides through the area for Monday into Monday night
for a chance of showers and thunderstorms. May have to keep an eye
on this for a possible severe treat with GFS/EC showing 1500-
3000J/kg of MUCAPE and 0-3km bulk shear of 30-40kt.
Looks like another chance of showers and thunderstorms for Wednesday
into Thursday as both the GFS/ECMWF showing low pressure/warm front
pushing into the region.
Temperatures from Monday through Thursday look to be right around
or slightly above normal with highs in the 70s.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 630 PM CDT Thu Sep 15 2016
Upper level shortwave driving areas of shra/ts mostly eastward
across the area this evening...with more showery pcpn then likely
overnight into Friday. See some thunder potential with that...but
confidence in timing isn`t high enough to add to the forecast. That
said, will time the line of storm through this evening, with some
enhanced gusts...near 30kts...around them. Associated lower
cigs/vsbys with the storms...with the low cigs expected to hang
around into Fri morning. Mostly mvfr.
Expect some bump upwards in cigs as the day wears on Friday...which
could drop back down to at least mvfr levels overnight Fri/Sat as
a low pressure system moves northeast.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
IA...None.
&&
$$
SHORT TERM...DAS
LONG TERM...DAS
AVIATION...Rieck
Area Forecast Discussion
National Weather Service Columbia SC
1011 PM EDT THU SEP 15 2016
.SYNOPSIS...
High pressure will ridge into the forecast area from the north
and Julia will linger just off the South Carolina coast through
the weekend. Most of the moisture associated with Julia will stay
east of the forecast area.
&&
.NEAR TERM /UNTIL 7 AM FRIDAY MORNING/...
Julia has regained tropical storm status and is located off the
southern coast of South Carolina. Much of the associated moisture
will remain east of the forecast area overnight. Surface high
pressure over the Great Lakes region will move off the New England
coast overnight.
Latest composite radar showing no precipitation across the
Midlands or CSRA this evening. PWAT values still around 1.3
inches over much of the Midlands and CSRA.
Decent mixing will limit radiational cooling and fog formation
during the early morning hours. Overnight lows will be in the
lower 70s to around 70 and winds will become light. Latest HRRR
indicating some clouds filtering into area from the northeast
overnight so have increased cloud cover somewhat for the entire
area during the early morning hours.
&&
.SHORT TERM /7 AM FRIDAY MORNING THROUGH SATURDAY/...
The models have trended drier in the forecast area. High pressure
will ridge southward and into the area through Saturday. Julia
will linger just off the South Carolina coast. The models keep
most of the moisture associated with Julia east of the forecast
area. Forecasted just slight chance pops in the east part because
of wrap-around moisture associated with the offshore low and
heating. The NAM depicted weak instability with surface-based LI
values -2 to -3. High low-level moisture and nocturnal cooling
will likely result in stratus during the early morning hours.
Boundary layer wind should limit fog. Followed the guidance
consensus for the temperature forecast.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
The models have trended drier. The GFS and ECWMF show Julia
lingering near the South Carolina coast early but keep much of the
moisture east of the forecast area. There also appears to be
little moisture associated with a diffuse cold front in the area
Monday. The models display ridging in the forecast area Tuesday
and Wednesday but some lingering troughing just off the Southeast
coast. The GFS and ECMWF MOS have pops less than 30 percent
through the period with temperatures mainly above normal.
&&
.AVIATION /02Z FRIDAY THROUGH TUESDAY/...
VFR conditions expected through at least 06z but stratus late
tonight will result in restrictions toward morning at some of the
terminals.
Satellite early this evening indicating mainly clear skies across
the region. Tropical Storm Julia well offshore of South Carolina
expected to remain nearly stationary.will not impact the region.
Ridge of high pressure across the western Carolina with drier air
in the Midlands/CSRA. Dry air aloft tonight but models indicate
low-level jet and mixing expected in the boundary layer to limit
fog development. However...HRRR guidance and Lamp indicating
stratus will advect south from North Carolina late tonight and
spread across the Midlands during the early morning. So...a period
of MVFR or IFR conditions during the morning...but kept AGS/DNL
VFR with confidence lower that low clouds will spread across the
CSRA. Stratus mixing out around 15z. VFR rest of period with
northeast winds around 10 knots and scattered cumulus.
EXTENDED AVIATION OUTLOOK...Chance of mainly afternoon/evening
thunderstorms through early next week, as well as early morning
fog/stratus.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
GA...None.
SC...None.
&&
$$
Area Forecast Discussion
National Weather Service Dodge City KS
943 PM CDT THU SEP 15 2016
...UPDATE TO SYNOPSIS...
.SYNOPSIS...
Issued at 942 PM CDT Thu Sep 15 2016
WV imagery indicates an upper level trough of low pressure moving
eastward across the Northern Plains. Near the surface, a weak
Pacific cold front is pushing slowly southeastward across northwest
Kansas.
&&
.SHORT TERM...(This evening through Friday)
Issued at 203 PM CDT Thu Sep 15 2016
The short term convective allowing models, specifically the WRF
runs have shifted their solutions more toward what the HRRR had
been forecasting through the day in terms of convection. That
keeps the bulk of the storm initiating mid afternoon across
eastern colorado, as just isolated cells, but growing upscale into
north west and northcentral Kansas including the I-70 corridor by
mid evening). These storms will be initiating along the weak cold
front/surface convergence zone.
The aforementioned cold front will move into the area tonight,
probably reaching the southeast 1/3 or so of the DDC forecast
area by midday Friday. This will act to decrease highs by around
10 degrees from Today as well as act as a convergence zone for
potential late day surface based convection again on Friday. In
either case, the set up in weak opt moderate CAPE/instability and
very weak shear in the absence of an jets.
.LONG TERM...(Friday night through Thursday)
Issued at 203 PM CDT Thu Sep 15 2016
The best chance for weekend precipitation appears late Saturday
or Saturday night with a signal in the GFS of elevated shower and
thunderstorms set of by a moderate shortwave in the westerlies.
Otherwise, a mainly zonal upper flow and overall dry regime is in
place for the medium to extended period. A warming trend is also
forecast, with models and consensus blends indicated highs back to
around 90 degrees by early next week.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 612 PM CDT Thu Sep 15 2016
As a shortwave trough moves across the Central Plains tonight, a
cold front will move across western Kansas. The best chances for
isolated storms is in the KHYS area early tonight. The front
should be near a KHYS to KGCK area by 09-12Z, then at KDDC around
15Z. Some areas of IFR/MFVR conditions are possible mainly at KGCK
and KHYS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 61 81 58 81 / 20 30 30 10
GCK 58 76 55 80 / 20 20 20 10
EHA 58 77 56 79 / 10 20 30 30
LBL 61 80 58 80 / 20 30 30 20
HYS 60 77 55 80 / 50 20 20 10
P28 66 82 63 82 / 10 50 50 10
&&
.DDC Watches/Warnings/Advisories...
NONE.
&&
$$
SYNOPSIS...JJohnson
SHORT TERM...Russell
LONG TERM...Russell
AVIATION...Kruse
Area Forecast Discussion
National Weather Service Quad Cities IA IL
648 PM CDT THU SEP 15 2016
...AVIATION UPDATE...
.SYNOPSIS...
Issued at 320 PM CDT Thu Sep 15 2016
Increasingly warm and humid air moved into the area through early
afternoon. Temperatures ranged from the upper 70s to lower 80s
under a partly sunny sky. The bulk of the shower and thunderstorm
activity was confined to northwest Iowa into southern Minnesota.
&&
.SHORT TERM...(This Evening through Friday)
ISSUED AT 320 PM CDT Thu Sep 15 2016
Main forecast issues in the short term period
In the near term, isolated showers continue to pop up across the
southern counties. Given the weak layer shear and more favorable
forcing to the west, any storms that do develop should have a hard
time sustaining themselves. The western fringe of the forecast
area would be most favored for additional isolated development
before 00Z, but the bulk of the rain is expected to hold off until
late evening and overnight. Morning runs of the HRRR continue to
verify reasonably well, albeit a bit slow, and were generally
followed for pops through tonight. SPC has pushed the marginal
risk area to the west of the forecast area, with unfavorable
timing for much in the way of a severe threat. The main issue will
continue to be locally heavy rain, with a well above normal
precipitable water feed over 1.5 inches poised to stream into the
forecast area tonight.
On Friday, the most favorable moisture will shift along and east
of the Mississippi River, and additional localized heavy rain is
more likely in the south. Again, no severe storms are expected.
Abundant cloud cover will limit insolation and should keep
afternoon highs down in the mid to upper 70s.
.LONG TERM...(Friday Night through Thursday)
ISSUED AT 320 PM CDT Thu Sep 15 2016
Thunderstorm chances continue for much of Friday night into early
Saturday morning along and ahead of the cold front pushing through
the region. Highest pops and greatest thunderstorm chances are kept
in the evening period, which then wane overnight through Saturday
morning with less favorable diurnal timing, weak shear and limited
forcing. Will keep at least low pops for showers going through
Saturday morning across the southeast based on the timing of the
attendant upper level shortwave trough axis. Breezy west to NW
winds and clearing skies will then follow for Saturday afternoon
with incoming lower dewpoints and highs limited to the mid and
upper 70s. The surface ridge that follows Saturday night will
provide mostly clear skies, light winds and min temperatures in
the 50s, if not around 50 across the cooler northern valleys.
Sunday through Thursday will be marked by a warming trend that will
see temperatures back into the lower 80s by midweek as the upper
level flow becomes zonal and then SW with the passage of a broad
upper ridge to the south. There are significant model difference
with the track of a passing surface low late Monday into early
Tuesday leading to low chances for showers and thunderstorms, which
may need to be increased if the more southerly trending ECMWF and
Canadian solutions continue. Beyond, chances for thunderstorms
remain in the forecast for Wed into Wed night, where the latest GFS
and ECMWF were beginning to suggest a more northerly depiction of a
slow moving front. If this trend continues, then the pops for
these periods may be overdone. Thursday into Saturday looks like
an active period with continued above normal temperatures and
thunderstorm chances with moisture flowing into the region under
an active west to sw flow aloft.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday Evening)
ISSUED AT 642 PM CDT Thu Sep 15 2016
Slow moving complex of storms over north-central Iowa to affect
terminals later tonight, especially at KCID/KDBQ. Have greatest
confidence for impacts at aforementioned sites, so mentioned
TSRA in TEMPOs roughly 04-07Z/Friday. Expect reduced visibilities
and ceilings from any storms, and possibly wind gusts over 25-30
kts. Further SE, confidence in organized showers and storms is
much lower; scattered activity may be the dominant mode.
Later Friday morning into the aftn, low confidence on anything
beyond isolated showers/storms, thus left out of TAFs for now.
Uttech
&&
.HYDROLOGY...
Issued at 320 PM CDT Thu Sep 15 2016
High river levels, due to recent heavy rains that fell over portions
of east central and especially north central and northeast Iowa,
continued to affect eastern Iowa tributaries. The greatest impact is
along portions of the Cedar and Wapsipinicon rivers.
Along the Wapsipinicon: Routed flow and the contribution from
forecast QPF over the basin the next couple days is currently
forecast to lead to minor flooding at Dewitt beginning late
Sunday. Confidence in this occurring remains low, due to both
uncertainty in the routed flow and the variability of rainfall
coverage and intensity in the current convective environment.
Thus, will continue to hold off on any watches and warnings for
this site.
On the Cedar River near Conesville: An approaching upstream crest is
forecast to pass the site just below flood stage, although there is
a still a potential that it could still push the river into minor
flooding Friday afternoon, which will be watched closely.
&&
.DVN Watches/Warnings/Advisories...
IA...None.
IL...None.
MO...None.
&&
$$
SYNOPSIS...RP Kinney
SHORT TERM...RP Kinney
LONG TERM...Sheets
AVIATION...Uttech
HYDROLOGY...Sheets
Area Forecast Discussion
National Weather Service Green Bay WI
1035 PM CDT THU SEP 15 2016
Updated aviation portion for 06Z TAF issuance
.SHORT TERM...Tonight and Friday
Issued at 354 PM CDT Thu Sep 15 2016
Partly sunny skies with temperatures in the upper 60s to middle
70s prevailed across the region at mid afternoon. The fair weather
cumulus clouds will dissipate around sunset. However, high clouds
will be on the increase during the evening and overnight. At this
time, the latest HRRR model now suggesting precipitation will not
arrive until after midnight. Have small chances of showers late
this evening across the west, with showers likely with a slight
chance of thunderstorms after midnight. Northeast and east-central
Wisconsin should remain dry through the night due to an abundant
amount of dry air in this region.
The rain will make a slow progress eastward into north-central and
central Wisconsin late tonight and should work into northeast
Wisconsin Friday morning. Again, dry air may slow its arrival and
may delay it to mid or late morning. The best chances for rain
will be Friday afternoon and evening as upper level system moves
across the region. The risk for severe weather appears to be very
low due to cloud cover and ongoing rain. If stronger storms were
to be found, they would be across northeast and east-central
Wisconsin where this region will have a chance to warm up before
the rain arrives.
Due to expected rain and low clouds, lowered high temperatures
on Friday across portions of north-central Wisconsin. Across
northeast and east-central Wisconsin, high temperatures will be
around late morning into mid afternoon before the rain arrives.
.LONG TERM...Friday Night Through Thursday
Issued at 354 PM CDT Thu Sep 15 2016
NWP models continue to be fairly consistent in clearing out
showers and thunderstorms from west to east Friday night as a cold
front departs the region to the east. Despite the passage of this
surface feature, the mid level trough will not track through the
area until Saturday, bringing a continued chance for showers to
the region during the first part of the weekend. The best chances
will be across north central Wisconsin given better moisture and
proximity to the mid level trough, however the latest model runs
indicate chances will extend south into central Wisconsin during
the afternoon hours given a bit better moisture than was
previously forecast.
A ridge of high pressure is forecast to build in across the
western Great Lakes on Sunday, bringing drier weather to the
region. However the latest model runs do generate some showers
near the Michigan border with lingering steep low level lapse
rates and meager moisture. Despite this model trend there does not
appear to be much in the way of forcing and as was mentioned
moisture is meager, therefore will keep the forecast dry for the
second half of the weekend with an eye on model trends.
In the early part of next week another low pressure system will
track through the western Great Lakes, bringing a renewed chance
for showers and thunderstorms Monday and Monday night. Moisture
with this system will be fairly meager, therefore will maintain
chancy pops for this period.
A stronger low pressure system with more moisture is set to impact
the western Great Lakes during the middle to late part of the
week. Despite continued model discrepancies, there appears to be
some convergence late in the forecast with the ECMWF and GFS
bringing precipitation to the area Wednesday and next Thursday.
Therefore confidence is a bit higher this run with respect to pops
which is reflected in the pop grids.
&&
.AVIATION...for 06Z TAF Issuance
Issued at 1027 PM CDT Thu Sep 15 2016
WAA and an approaching short-wave trof were combining to bring
a rapid increase in clouds across the forecast area late this
evening. Showers will be ongoing over parts of north central and
central WI at the beginning of the TAF period, and will be closing
in on the RHI/AUW/CWA sites. The showers should make their way
into eastern WI late tonight into early Friday. Look for ceilings
to drop into the MVFR/IFR category in central and north central WI
late tonight and early Friday. Flight conditions will be slower to
deteriorate in eastern WI, and should not drop to MVFR until mid
to late morning. An upper level disturbance is expected to bring
another uptick in shower and thunderstorm activity during the late
morning and afternoon period, with decreasing pcpn occurring from
southwest to northeast during the late afternoon and evening. It
appears that most of the tstm activity will stay to our south
overnight, so the main tstm threat should occur with the arrival
of the short-wave trof in the late morning and afternoon.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....Eckberg
LONG TERM......Kurimski
AVIATION.......Kieckbusch
Area Forecast Discussion
National Weather Service Houston/Galveston TX
917 PM CDT Thu Sep 15 2016
.DISCUSSION...
Higher chances for precipitation should remain along the coastline
this evening and overnight. Surface low pressure situated over
the Western Gulf will move westward over night and gradually evolve
into a coastal trough which should help focus precipitation between
08 to 10Z over mainly the coastal counties. Water vapor imagery
shows a weak upper level trough situated over the Western Gulf, and
its orientation should help to bring increased moisture levels this
weekend. The 00z CRP and LCH soundings indicated precipitable waters
between 2.0-2.20 inches, with K index values in the lower 30s. The
00z LCH sounding specifically showed good saturation at 850mb, most
likely due to the influence of the coastal troughing. Short term
model guidance is also in agreement, indicating the development for
precipitation along the coast and offshore waters tonight, and into
Friday. The RAP specifically focuses the majority of the
precipitation Friday morning more focused over the eastern half of
the coastal counties.
For tonight, raised min temperatures by a degree in a few spots to
match current trends. Also increased rain chances along the coast
for late tonight into Friday. 08
&&
.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL) 74 92 74 91 74 / 10 20 20 30 10
Houston (IAH) 76 90 75 90 74 / 20 40 20 40 10
Galveston (GLS) 81 87 79 87 79 / 50 50 40 50 30
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
Discussion...08
Area Forecast Discussion
National Weather Service Lincoln IL
908 PM CDT THU SEP 15 2016
.UPDATE...
Issued at 908 PM CDT Thu Sep 15 2016
Storms have remained west of our forecast area so far this
evening, with a small cluster of storms in eastern Missouri that
continue to dissipate as they reach near far western Illinois. A bowing
line in Iowa continues to slowly progress toward NW Illinois. The
consensus of the evening models points toward showers/storms
progressing into or developing over western Illinois later
tonight. It appears that storms will affect our forecast area
after 3 am near Galesburg, then advance to near Peoria to
Springfield by 6-7am. The wave of storms is projected to advance
toward I-57 during the morning, with a break in the storms for
areas west of I-55 from late morning through early afternoon. Will
slow down the start of storms in our western counties the rest of
the evening, and keep the focus for storms later tonight with
increasing PoPs late. We still expect likely rain/storms for
periods of time on Friday across all of central and southeast IL,
which is covered well in the grids. Main updates this evening were
to weather tonight, with minor updates to temp/dewpoint/winds.
Updated forecast info is already available.
&&
.SHORT TERM...(This evening through Friday)
ISSUED AT 254 PM CDT Thu Sep 15 2016
High pressure over the the Great Lakes area and Low pressure over
the northern Plains will continue to shift eastward over the
upcoming day, shifting the advection of warmer moister air from the
south into Illinois...ahead of an approaching cold front. Currently
the front is located roughly north to south over the western Plains.
As the pattern shifts eastward central IL will see increasing
chances of thunderstorms overnight...with most of the area seeing a
chance by sunrise...especially west of I-55 where PoPs are in the
likely category. A continued shift eastward is expected through
afternoon. Central IL will be firmly into a 1.75 inch precipitable
water plume by Friday morning. Instability will increase to 500-1500
J/KG by Friday afternoon according to forecast soundings...while
surface-6km bulk shear values expected to be modest at 20-30 kts. As
a result...we should see rather disorganized scattered
thunderstorms...with a slow movement and mainly a heavy rain
potential in stronger storms.
Lows tonight should be quite mild with cloudy conditions and
seasonally high dewpoints in the 60s. Lows, as a result should be
mid and upper 60s. Highs tomorrow...low to mid 80s I-55
eastward...with upper 70s possible to the west in more prevalent
showers and cloud cover.
.LONG TERM...(Friday night through Thursday)
ISSUED AT 254 PM CDT Thu Sep 15 2016
A cold front will slowly move toward and through the CWA the first
part of the weekend, so showers and thunderstorms will remain likely
Friday night through Saturday. As this front moves east of the CWA,
high pressure will begin to move into the area and bring dry weather
to the region for the later part of the weekend and into the
beginning of next week. However, since the mid level trough will not
be moving through the CWA until early Sunday morning, showers and
isolated thunderstorms will remain possible in the east and
southeast through Saturday evening. Dry weather is then expected
over most of the area for the first part of the week. However,
another system will slide across the Great Lakes region Monday night
with a trailing cold front moving across Illinois. This front will
have limited moisture given the lack of return flow, so best chances
of precip will be in the north and northwest parts of the CWA for
Monday night. Then dry weather is again expected for the remainder
of the week.
Temps will be around normal for the weekend, but with zonal flow
over the northern half of the US and mid level ridging building into
the southern and southeastern US temps will be in the 80s for the
week, which is above normal for the middle of September.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 700 PM CDT Thu Sep 15 2016
A shortwave is progressing toward central IL from the S-SW in
southern Missouri. There have been waves of storms in western IL
already late this afternoon that have dissipated with time, but
dropped heavy rain of 1 to 1.5 inches in a short period of time.
The HRRR and RAP models are pointing toward storm chances mainly
increasing after midnight tonight, with a wave of storms between
10z and 15z progressing from west to east across the terminal
sites. A decrease in storm coverage is indicated for the 16-18z
time frame, with expanding coverage in eastern Illinois for later
Friday afternoon and evening. Will include prevailing rain/storms
with the late night/early morning line of storms, then stick with
VCTS the remainder of the TAF for now.
Winds will be SE for a majority of this TAF period, with a shift
to southerly Friday afternoon as the cold front approaches
Illinois. Wind speeds outside of storms should prevail at 10kt or
less.
&&
.ILX Watches/Warnings/Advisories...
NONE.
&&
$$
UPDATE...Shimon
SHORT TERM...Onton
LONG TERM...Auten
AVIATION...Shimon
Area Forecast Discussion
National Weather Service Omaha/Valley NE
751 PM CDT THU SEP 15 2016
.UPDATE...
Issued at 742 PM CDT THU SEP 15 2016
Very compact area of thunderstorms continues across northeast NE
and west central IA this evening. This cluster is being fed by
continued warm moist advection on the nose of low level jet. The
00z KOAX sounding yielded 1.83" of precipitable water, which is
just shy of the record 2.0 for this date. This cluster was
responsible for several supercells earlier with many reports of
funnel clouds and large hail. Through time, it has transitioned to
heavy rain and wind. The flash flood watch issued earlier captures
this area very well, and 4 flash flood warnings remain in effect.
We are now getting reports of water over streets and low lying
areas in many of the warning polygons, with radar estimating 2.5
to 3 inches over a very wide area. 1 severe warning remains in
effect for both wind and hail. The severe watch that was issued
late in the afternoon was trimmed a bit on the southern edge to
remove the Omaha and Council Bluffs metro areas since it appears
that storms were setting up just north of the area. The original
watch is valid until 9 pm and that appears to be working out, and
will make a final decision if any counties may need an extension
for within the next 45 minutes.
Meanwhile, storms are developing west of the region tonight across
central NE and northwest KS. These storms are expected to continue
to roll eastward overnight, moving into our forecast area as early
as 11 pm in northeast NE, then spreading eastward into other areas
through the night. These storms will also have a wind and hail
threat, but may also be fighting an unfavorable time of day.
&&
.SHORT TERM...(tonight through Sunday)
Issued at 301 PM CDT THU SEP 15 2016
Primary concern tonight is convective development and overall
effects as an upstream trough and cold front move into the region.
Convection has festered most of the morning in northeast NE and
while it was never strong, it was very efficient at generating
rainfall with a report of 4.3 inches in Knox county. Additional
convection has fired in northeast NE this afternoon in response to
the tail end of the first piece of energy moving away from the
region...within an overall very moist environment with PW values
around 150% of normal this morning.
20z objective surface analysis indicated the cold front was well
west of the forecast area, however a subtle warm front had pushed
through the mid Missouri valley with temps now in the lower 80s
across much of the area. Most recent HRRR model continues to
suggest strong and possibly severe storm development in northeast
NE into northwest IA...which may become more west/east oriented
resulting in training of cells through the evening north of the
Platte River. Am concerned that given environmental moisture which
is 1-2 standard deviations above normal, warm cloud depths, high
moisture transport on a continued low level jet, this is an area
that could be primed for flash flooding given 300-500% above
normal rainfall in the last 7 days. Thus will issue a flash flood
watch for a few counties north of the Platte River tonight.
Elsewhere, while heavy rain will be possible with storms as the
upper low pushes in from the west, enough of a cold pool may
develop to help keep storms progressive.
Regarding severe potential tonight, environmental shear of 30-40
knots combined with mixed CAPE of 2000-2500 J/Kg should be
sufficient for rotating storms with wind and hail potential in the
stronger storms, but given decent low level turning near the warm
frontal boundary there will also be a small tornado threat that
we`ll have to monitor. Will have fairly high pops 60-80% across
the forecast area tonight, with timing initially in northeast NE,
then spreading east southeast into the remainder of the forecast
area by late evening and overnight.
Storm chances linger in southeast NE on Friday, but should push
east of the forecast area Friday evening.
Dry and mild weather persists Saturday. Models hint at a weak wave
quickly moving across the Plains Saturday night so have added a
slight chance of rain for some areas. Wave should be east of the
area by Sunday with dry weather expected.
.LONG TERM...(Sunday night through Thursday)
Issued at 301 PM CDT THU SEP 15 2016
Dry weather early in the period, with rain chances returning by
Tuesday night through Thursday, although models are not in good
agreement with the GFS more bullish on precip and the ECMWF more
dry.
&&
.AVIATION...(00Z TAFS for KOFK...KLNK and KOMA.)
Issued at 645 PM CDT THU SEP 15 2016
Thunderstorms will be the primary concern tonight. Storms are
already in the vicinity of KOFK, but remain just north of KOMA,
and well away from KLNK. Tried to time storms into and out of the
TAF locations through, but ending by 06-09z, with showers that
linger beyond then. Somewhat low confidence of specific timing,
and will amend forecasts for higher impacts as necessary.
&&
.OAX Watches/Warnings/Advisories...
NE...Flash Flood Watch until 5 AM CDT Friday for NEZ015-032>034-
043>045.
IA...Flash Flood Watch until 5 AM CDT Friday for IAZ043-055-056.
&&
$$
UPDATE...DeWald
SHORT TERM...DeWald
LONG TERM...DeWald
AVIATION...DeWald
Area Forecast Discussion...UPDATED
National Weather Service SAN ANGELO TX
704 PM CDT THU SEP 15 2016
.AVIATION...
/00Z TAFS/
Scattered showers and thunderstorms will continue across the
Big Country, Concho Valley and Heartland areas through late
this evening, and for the most part should dissipate by
Midnight. Carrying a thunderstorm mention at the start of this
TAF period at KABI and VCTS at KSJT, based on radar trends.
VFR conditions are expected through most if not all of tonight.
Patchy low cloud development is expected early Friday morning
across southern parts of west central Texas, and carrying
scattered low cloud groups at KSOA and KJCT. A VFR-based
cumulus field is expected by midday. Scattered showers and
thunderstorms are possible Friday afternoon across the Big
Country, mainly north and west of KABI. Outside of convective
activity, winds will be mainly from the southeast and south
tonight, and mostly from the south on Friday.
&&
.PREV DISCUSSION... /issued 337 PM CDT THU SEP 15 2016/
SHORT TERM...
(Tonight and Friday)
Latest HRRR continues to show embedded disturbances in the flow
aloft tracking eastward primarily across the northern half of the
forecast area into this evening. Totals approaching 3 inches have
already fallen this afternoon over the eastern Big Country. The
northern half of the forecast area will remain the primary target
for additional rainfall through tomorrow. The main weather impact
will continue to be localized flooding.
Morning lows tomorrow will be a few degrees warmer than this
morning with temperatures mostly in the lower 70s. Afternoon highs
tomorrow should also be a few degrees warmer than today with
temperatures in the lower 90s expected.
15
LONG TERM...
(Friday night through next Thursday)
A summer-like pattern will control the weather in west central
Texas in the long term. Upper level ridging is in place from
southeastern Texas east across the Gulf of Mexico region.
Although there are weak disturbances embedded within this ridge,
these are not expected to affect west central Texas over the next
week.
This ridging puts our area right on the eastern edge of stronger
southwest flow. This flow, combined with abundant low level
moisture, and weak cold fronts and/or leftover boundaries from
previous convection will continue to result in a chance for
showers and thunderstorms for our area from Friday night into
Saturday evening with diminishing chances into early next week.
The best chances at this time appear to be late Friday night into
Saturday morning, depending on the timing of a disturbance moving
through the area Friday night, along with the southern reach of a
cold front expected to move into the Texas Panhandle region.
Following this, upper level ridging becomes centered more over
Texas from Sunday through the middle of next week. This will lower
our rain chances for next week, and result in warmer than normal
temperatures across the area.
20
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 70 89 69 89 / 20 30 50 40
San Angelo 70 93 70 91 / 20 10 30 20
Junction 70 92 70 93 / 20 5 20 30
Brownwood 70 91 70 91 / 20 20 40 40
Sweetwater 70 89 69 88 / 30 30 50 30
Ozona 70 90 69 90 / 20 10 20 20
&&
.SJT Watches/Warnings/Advisories...
None.
&&
$$
Area Forecast Discussion
National Weather Service Albuquerque NM
340 AM MDT FRI SEP 16 2016
.SYNOPSIS...
A back door cold front will provide the focus mechanism for
scattered to numerous showers and thunderstorms along and east of
the central mountains today. Another round of severe weather is
expected and will favor the east slopes of the Sangre de
Cristos...east central and southeast plains. The atmosphere will
begin to dry this weekend and also gradually warm as a low cuts
off well to the west of the state. The cut off low and subtropical
high will work in unison to usher abundant moisture northward
during the earlier half of next week. The moisture increase is
expected to favor the western half during this period although
expect some changes in the forecast as we get closer to that event
period.
&&
.DISCUSSION...
Main focus and forecast challenge today will be the back door
cold front position as it rapidly pushes south and westward. The
current frontal position which shows up on radar near I40 between
TCC and CQC appears to be a few hours fast compared to boundary
layer flow forecasts from the NAM/GFS. The latest RUC and
mesoscale models appear to have a better handle on it. Decided to
adjust highest PoP`s to reflect where the best sfc convergence and
upslope would be found. This boundary will also serve as a focus
for some severe weather. Shear...both directional and speed...
appear to be more than adequate while the higher CAPE values will
be largely dependent on the frontal intrusion. Dewpoints are lower
overall behind the frontal passage. Latest NAM appears to have a
better handle in the boundary layer moisture field than GFS. Both
models appear to forecast the stronger than normal subtropical
jet max position fairly well and will aid lift across portions of
the forecast area this afternoon/evening.
Models continue to show a drying trend for this weekend. Residual
frontal impacts and jet max exit region should produce scattered
storms across the east on Saturday. A drier southwest flow should
occur from west to east as the weekend progresses and lower
coverage patterns overall. Temperatures would begin to warm during
this period.
A pesky cut off low which is currently showing up in the satellite
data combined with a building subtropical high will be the main
weather drivers during at least the earlier half of next week.
Models have had a hard time dealing with this low and that is to
be expected. Thus a lower confidence period. Either way...still
looking for a moisture subtropical flow to develop over portions
of the forecast area during this period. It appears western areas
would remain favored. Some uncertainty as to how much moisture
would flow northward. The ECMWF and Canadian show some sort of
tropical tap from a system or wave that develops off the Mexican
coast. Current water vapor imagery shows some evidence of that
development so leaning towards the ECMWF/GEM. The GFS has been
trending this way somewhat past couple of runs. So some confidence
building there although still quite a bit of uncertainty. Despite
the heavier rainfall chances...sfc high temps appear to be above
normal due to higher than usual 700 mb temps.
The rest of next week will largely be determined by the evolution
of the cut off low translation as well as the next long wave
trough. Too early to say about drier westerlies vs some sort of
pseudo subtropical tap.
50
&&
.FIRE WEATHER...
While roughly the west third of NM will see very little to no
shower and thunderstorm activity today and Sat, there will still
be a good to excellent chance of same across the east half of the
state today and a decent, though a little lower, lingering chance
again Sat. Both afternoons and evenings there is once again a
risk of strong to even severe storms plus locally very heavy rain
across the east third to nearly half of the state. Across the
approximately west third of the state enough dry air will nudge
in to lower minimum RH near or below 15 percent and boost Haines
indices into the 5 to 6 range. All this will come about due to
the intrusion of quite dry air through a deep layer of the
atmosphere into that part of the state. A fairly weak back door
cold front will make some further progress south and to some
degree west across the east half of the state through the day
today. This will inject some additional low lvl moisture into
that part of the state and also help provide some extra focus for
storm development. The ventilation categories will generally
range from poor to fair today east of the central mtn chain,
though a few rather small pockets there may reach the good
category. Farther west will be good to excellent ventilation.
Pretty much all locales will see good to excellent rates Sat
and Sun.
It looks even more likely now that as the weekend progresses the
upper low developing west of NM will retrograde southwestward to
off the Baja Peninsula coast, while a moderate strength high
pressure ridge aloft will develop across west NM and east AZ.
This will dry the air mass out further across NM. Showers and
storms will be unlikely on Sun and Mon, though slight chances
have been kept in fcst for far south to southwest portion of the
fcst area. Widespread Haines of 4 plus is expected Sun and Mon
with 5 and 6 values covering more area Mon compared to Sun. as
daytime temps warm to a few to several degrees above normal
values for this time of year.
The Tue to Thu period of the coming work week will usher in more
moisture and increasing shower and thunderstorm chances as the
Baja low gradually opens up and heads northeast into the SW U.S.
Temps will also begin to cool and Haines indices will trend
downward as the better moisture arrives.
43
&&
.AVIATION...
06Z TAF CYCLE
VFR conditions prevail and are forecast to persist with a couple
of exceptions. MVFR conditions can be expected in/near storms Friday
afternoon/evening, with short-lived IFR conditions possible.
Terminals most likely to be impacted by storms Friday are KLVS,
KROW and KTCC, and generally ranking in that order in terms of
forecaster confidence. MVFR cigs may redevelop at KTCC overnight
and possibly KROW, but forecaster confidence generally low on
sub-VFR conditions. An east canyon/gap wind will develop Friday
evening and impact KSAF and KABQ, and may be stronger than
currently forecast.
&&
.PRELIMINARY POINT TEMPS/POPS...
Farmington...................... 80 44 81 44 / 0 0 0 0
Dulce........................... 75 37 76 35 / 10 10 10 5
Cuba............................ 73 45 74 42 / 20 20 10 5
Gallup.......................... 78 36 79 38 / 0 0 0 0
El Morro........................ 74 36 76 38 / 5 5 5 0
Grants.......................... 78 40 79 40 / 10 5 5 0
Quemado......................... 76 42 78 43 / 5 0 5 0
Glenwood........................ 82 52 84 53 / 0 0 0 0
Chama........................... 68 37 69 35 / 20 10 10 10
Los Alamos...................... 72 48 74 47 / 30 30 20 10
Pecos........................... 71 47 73 46 / 60 40 40 20
Cerro/Questa.................... 70 43 71 38 / 30 20 30 10
Red River....................... 60 38 61 34 / 40 40 30 10
Angel Fire...................... 65 34 67 32 / 60 50 30 20
Taos............................ 72 41 73 39 / 30 20 20 10
Mora............................ 66 43 69 42 / 60 50 40 20
Espanola........................ 77 51 79 47 / 20 30 20 10
Santa Fe........................ 72 49 74 47 / 40 30 30 20
Santa Fe Airport................ 76 49 78 47 / 20 20 20 20
Albuquerque Foothills........... 79 54 80 52 / 20 20 10 10
Albuquerque Heights............. 81 56 82 55 / 20 10 10 5
Albuquerque Valley.............. 83 55 84 55 / 10 10 10 5
Albuquerque West Mesa........... 82 54 83 53 / 20 10 10 5
Los Lunas....................... 83 53 84 54 / 10 10 10 5
Rio Rancho...................... 82 53 83 52 / 20 10 10 5
Socorro......................... 85 54 86 57 / 10 10 10 5
Sandia Park/Cedar Crest......... 74 49 75 48 / 30 30 10 10
Tijeras......................... 77 51 79 49 / 30 20 10 10
Moriarty/Estancia............... 75 48 77 46 / 30 30 20 20
Clines Corners.................. 72 47 75 47 / 60 30 20 20
Gran Quivira.................... 76 50 78 50 / 30 10 10 10
Carrizozo....................... 81 54 82 56 / 20 10 20 20
Ruidoso......................... 74 49 75 51 / 30 20 20 20
Capulin......................... 70 45 73 45 / 30 40 50 40
Raton........................... 74 45 76 43 / 40 50 50 20
Springer........................ 75 47 76 45 / 40 60 40 20
Las Vegas....................... 71 46 74 46 / 60 60 30 20
Clayton......................... 76 52 78 54 / 20 30 50 30
Roy............................. 74 49 75 50 / 30 50 50 30
Conchas......................... 80 57 82 59 / 30 50 40 20
Santa Rosa...................... 80 56 81 56 / 50 40 20 20
Tucumcari....................... 82 58 84 60 / 40 40 30 30
Clovis.......................... 79 57 81 59 / 50 60 40 30
Portales........................ 80 59 81 60 / 60 60 40 40
Fort Sumner..................... 80 59 82 59 / 50 50 30 20
Roswell......................... 85 61 85 61 / 50 30 20 20
Picacho......................... 79 55 79 57 / 40 20 20 20
Elk............................. 77 52 77 54 / 40 20 20 20
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
50
Area Forecast Discussion
National Weather Service Denver/Boulder CO
230 AM MDT FRI SEP 16 2016
.SHORT TERM...(Today and tonight)
Issued at 212 AM MDT Fri Sep 16 2016
The surface cold front has exited the state to the south this
evening and a ridge of high pressure has settled across most of
the state, resulting in nearly calm winds and mostly clear skies.
The mid and upper level trough will move off to the northeast
across the Red River Valley of the North by Friday afternoon.
Synoptic scale forcing on Friday will be neutral throughout the
day and into the overnight hours with the nearly zonal 500mb
flow. Precipitable water values decrease to 0.50-0.75" across the
Plains with low level downslope flow. There is some weak
instability, which is strongest along the foothills but only in
the 300-500 J/kg range. Models differ on available surface
moisture to generate and sustain thunderstorms from the mountains,
with the HRRR and RAP keeping most areas dry, while the NAM
appears to be the wettest model. Feel the NAM is overdone and thus
expecting at best only isolated thunderstorms primarily in the
mountains and foothills and along and east of the Palmer Divide.
In terms of Friday`s temperatures, expect them to be a few degrees
cooler than Thursday, but still warm into the low 70s across the
Plains and into the mid to upper 50s in the high country.
Overnight into Saturday morning again expect clearing skies and
light winds resulting in seasonally cool low temperatures in the
mid to upper 40s Plains to the lower to mid 30s in the mountains.
Lee troughing east of the Rocky Mountains should result in a
return to southerly low level winds Saturday morning.
.LONG TERM...(Saturday through Thursday)
Issued at 212 AM MDT Fri Sep 16 2016
On Saturday...an upper level trough of low pressure will stretch
from southern California into the northern Great Plains
States...with a moderate westerly flow aloft over Colorado. The
NAM...GFS and the ECMWF all show a decent upper level short wave
moving across northeastern Colorado during the afternoon. Models
also show a downslope flow across the foothills and Front Range
Urban Corridor by mid morning spreading eastward across the plains
during the afternoon...with a possible dryline setting up across far
northeastern Colorado. The downslope flow should limit precipitation
chances across the foothills and adjacent plains including Metro
Denver.
Convergence along the dryline...along with higher moisture
values and upward forcing from the shortwave may kick off some
showers and thunderstorms. The timing of the shortwave and how long
the higher dewpoints remain across the eastern zones will be
critical for storm development. The GFS shows the moisture flushing
out of the area by early afternoon with little cape. However...the
NAM holds in the moisture through late afternoon and has capes over
1000 J/KG along with some shear. If the GFS is correct...the plains
should remain mostly dry...with only isolated light to moderate
showers and storms. However...if the NAM verifies there could be
isolated to scattered showers and storms across our far eastern
zones...some of which could be strong to severe. The best chance for
the stronger storms looks to be across Lincoln and eastern
Washington Counties.
Warmer and drier weather is expected Sunday through Tuesday as upper
level high pressure builds over the Rocky Mountain Region. The GFS
tries to bring in some monsoonal moisture into the southwestern half
of Colorado by Tuesday...which may result in isolated storms across
the high country...mainly south of Interstate 70.
By the middle of next week...an upper trough develops over the the
Pacific Northwest...with a west to southwest flow aloft over
Colorado. Both the GFS and ECMWF try to pump some monsoonal into
Colorado...mainly across the western half of the state. Some energy
from the trough...combined with higher moisture values...should lead
to cooler temperatures and a little better chance for precipitation
Wednesday and Thursday
&&
.AVIATION...(For the 06Z TAFS through 06Z Friday night)
Issued at 212 AM MDT Fri Sep 16 2016
VFR expected through Friday night. Light and variable winds will
turn easterly after noon and remain light at all terminals. A
stray thunderstorm may generate a gust front that would
temporarily shift wind direction and increase magnitude in the
early evening, but overall expect excellent aviation weather
through 12Z Friday.
&&
.BOU Watches/Warnings/Advisories...
None.
&&
$$
SHORT TERM...Schlatter
LONG TERM...Kalina
AVIATION...Schlatter
Area Forecast Discussion
National Weather Service Columbia SC
333 AM EDT FRI SEP 16 2016
.SYNOPSIS...
High pressure will ridge into the forecast area from the north
and Julia will linger just off the South Carolina coast through
the weekend. Most of the moisture associated with Julia will stay
east of the forecast area. A weak cold front will cross the area
Monday with high pressure building into the area by the middle of
next week.
&&
.NEAR TERM /THROUGH TONIGHT/...
TS Julia will remain off the coast of South Carolina with its
associated moisture east of the midlands. Upper level ridge over
the Florida will extend northward into the Carolinas.
Surface high pressure centered just off the New England coast
will ridge into the area from the north. Satellite and surface
observations indicated low clouds moving into the Northern
Midlands from the north early this morning. Models indicated
these clouds will spread southward...reaching the CSRA around
sunrise and linger into late morning.
Dry weather is forecast today with subsidence over the area.
Once morning clouds clear...sunny skies are foreseen for the
afternoon. Precipitable water values will be less than 1.5 inches
with minimum instability over the area. We went with high
temperatures on the warm side of guidance...in the mid 80s north
to near 90 south. Kept overnight lows near consensus in the 65 to
70 degree range. Low clouds are expected to develop across the
area again late tonight given a moist northeast low level flow.
&&
.SHORT TERM /SATURDAY THROUGH SATURDAY NIGHT/...
High pressure will ridge southward and into the area through
Saturday night. Upper level ridging over the southeastern states
will begin to retreat southward Saturday night. Julia will linger
just off the South Carolina coast. The models keep moisture
associated with Julia east of the forecast area...so have
indicated another day of dry weather.
Followed the guidance consensus for the temperature forecast
with highs in the mid 80s to around 90 and lows in the mid 60s to
around 70 degrees.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
The GFS and ECWMF show Julia lingering near the South Carolina
coast early but keep much of the moisture east of the forecast
area. There also appears to be little moisture associated with a
diffuse cold front in the area Monday. The models display ridging
in the forecast area Tuesday and Wednesday but some lingering
troughing just off the Southeast coast. The GFS and ECMWF MOS have
pops less than 30 percent through the period with temperatures
mainly above normal.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
VFR conditions expected through at least 10z. HRRR then brings
stratus deck and mvfr or lower restrictions in from the north
between 10z-15z at cae/cub/ogb. Stratus may not make it to
ags/dnl.
Satellite showing low-level stratus pushing southward across North
Carolina. This stratus should continue pushing into South
Carolina, and will impact Midlands terminals by 10z. Dry air
aloft tonight but models indicate low-level jet and mixing
expected in the boundary layer to limit fog development.
Stratus mixing out around 15z. VFR rest of period with northeast
winds around 10 knots and scattered cumulus.
EXTENDED AVIATION OUTLOOK...Chance of mainly afternoon/evening
thunderstorms through early next week, as well as early morning
fog/stratus.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
GA...None.
SC...None.
&&
$$
Area Forecast Discussion
National Weather Service Grand Rapids MI
552 AM EDT FRI SEP 16 2016
LATEST UPDATE...
Marine
.SYNOPSIS...
Issued at 328 AM EDT Fri Sep 16 2016
Yet another system will stream gulf moisture into the area
this afternoon into Saturday morning. This will result in periods
of showers and a few thunderstorms from mid afternoon into the
early morning hours of Saturday. Rainfall may be locally heavy
during this time. The cold front moving through the area later
Saturday may trigger a few more thunderstorms but these will be
more widely scattered and not all areas will see these storms.
Some clearing is expected Saturday night but there will an
isolated thunderstorm can not be ruled out Sunday afternoon either.
Dry air return Sunday night into Tuesday... then when the warm air
tries to push back expect another period of showers and
thunderstorms with unseasonably warm temperatures during the mid
week.
&&
.SHORT TERM...(Today through Sunday)
Issued at 328 AM EDT Fri Sep 16 2016
There are many issues to deal with for this forecast. Mostly this
means timing the convection into Southwest Lower Michigan and
figuring out just how much rain will fall between noon today and
mid morning Saturday.
Currently there is a weakening area of thunderstorms over Iowa
into western Wisconsin at 3AM this morning. This is largely
associated with the surge of deep moisture being pushed north 90
knot polar jet core over western Minnesota and a 40 knot low
level jet. There is also a southern stream wave tracking northeast
from Missouri. All of this surges into Southwest Lower Michigan by
mid afternoon. The latest runs of the RAP and HRRR show the
instability makes a stronger run at us than the models had
forecast yesterday. Also the 1000 to 850 moisture transport
vectors look more focused than they did yesterday. The high
resolution HRRR and RAP model and our time lagged ensembles (not
to mention the SREF) have likely to conditional pops for our area
by mid afternoon into tonight as all this happens. Our
precipitable water values approach record values for this time of
year so heavy rainfall is possible. The deep layer shear is weak
and with the extensive cloud cover I do not see severe storms as
much of a issue but one can not rule out gusty winds in the
stronger storms.
The upper level low that has been booted out of the Southwest
CONUS still remains as a closed upper low into Saturday morning
(stronger than previously forecast by the models)... so I would
think there would be a decent chance of thunderstorms with the
cold front Saturday afternoon. We should see some clearly Saturday
night but there is enough cold air at mid levels and with the
upper trough lingering Sunday... an afternoon thunderstorm can not
be ruled out so I put 15 to 20 percent pops inland for that.
.LONG TERM...(Sunday night through Thursday)
Issued at 328 AM EDT Fri Sep 16 2016
Fair weather is expected Sunday night with a ridge of high pressure
in control of the wx pattern. The next chance for rain will come
late Monday through Monday night as a fast moving upper level
disturbance and cold front approach from the northwest.
Fair weather will return behind that system Tuesday through Tuesday
night as another sfc high pressure ridge builds in from the west.
However a warm front will bring potential for more showers and
perhaps a few storms late Wednesday and Wednesday night.
Temperatures will remain above to much above normal through the long
range forecast period and average around 10 to 15 degrees above
normal through the period.
&&
.AVIATION...(For the 06Z TAFS through 06Z Friday night)
Issued at 1129 PM EDT Thu Sep 15 2016
Vfr conditions will continue overnight through midday Friday.
Conditions will gradually deteriorate to Mvfr late Friday
afternoon through Friday evening as low clouds and showers move
in.
A few thunderstorms may also develop Friday evening but the threat
for thunderstorms is not sufficient enough to warrant mention in
any of the terminal forecasts at this time.
East winds overnight will gradually veer to the south on Friday
with wind speeds near to below 10 kts through Friday evening.
Brief reductions into the Ifr flight category are possible Friday
evening in heaviest showers.
&&
.MARINE...
Issued at 552 AM EDT Fri Sep 16 2016
SINCE WE ARE ALREADY GETTING 3 TO 4 FOOT WAVES AND 15 TO 25 KNOTS
WINDS IN OUR NORTHERN MARINE ZONES I DECIDED IT WAS BETTER TO
START THE HAZARDS NOW AND NOT WAIT TILL LATE THIS MORNING.
&&
.HYDROLOGY...
Issued at 1048 AM EDT Thu Sep 15 2016
Friday night into early Saturday will most likely produce
rainfall amounts between a quarter and half inch. Excessive
rainfall is unlikely given fairly weak and progressive forcing and
marginal instability. There is now some chance of afternoon
thunderstorm redevelopment on Saturday, but excessive rainfall is
not anticipated then either. Rivers are well within their banks.
&&
.GRR Watches/Warnings/Advisories...
MI...Beach Hazards Statement through late tonight for MIZ037-043-050.
LM...Small Craft Advisory until 5 AM EDT Saturday for LMZ847>849.
&&
$$
SYNOPSIS...WDM
SHORT TERM...WDM
LONG TERM...JK
AVIATION...Laurens
HYDROLOGY...CAS
MARINE...WDM
Area Forecast Discussion
National Weather Service Wichita KS
320 AM CDT FRI SEP 16 2016
.SHORT TERM...(Today through Sunday night)
Issued at 318 AM CDT Fri Sep 16 2016
Hit-or-miss clusters of showers/thunderstorms will affect the
forecast area today, as a cold front approaches from the north and
subtle upper waves approach from the west/southwest. Greatest
coverage early this morning will likely be generally the northeast
quarter of KS, with this activity likely largely diminishing by
mid-morning. Furthermore, weak isentropic ascent ahead of upper
energy approaching from the west should allow for at least widely
scattered showers/storms to eventually develop this morning over
south-central and southeast KS ahead of the cold front. This
activity could become widespread/numerous over far
southern/southeast KS.
Thinking the convectively-reinforced cold front will tend to race
southeast today faster than what NAM/GFS depict, limiting
afternoon/evening thunderstorm redevelopment across the forecast
area. This scenario is supported by the RAP and HRRR, and makes
sense given current southward speed of outflow/cold front. Will
still likely see at least a few storms in vicinity of the front
this afternoon-evening over southern KS, but probably not
widespread/numerous activity. Severe weather-wise, despite poor
mid-level lapse rates, modest instability along with adequate
deep layer shear may promote a few strong to marginally severe
storms throughout the day/evening, along with locally heavy rain.
Five-star weather expected across much of the area Saturday, as
high pressure settles south in wake of the cold front. An
approaching upper disturbance could result in a cluster of
thunderstorms over mainly western portions of KS and OK Saturday
night, with some of this activity possibly affecting locations
generally west of I-135. This activity could linger into Sunday
morning over far southern KS.
.LONG TERM...(Monday through Thursday)
Issued at 318 AM CDT Fri Sep 16 2016
Building upper ridging from the west should allow for dry weather
and above normal temperatures Monday and Tuesday. A weak front
should make its way into KS Mon- Tue, but weak convergence along
with poor upper support and warm mid- level temperatures should
keep the forecast area dry. Expecting thunderstorm chances to re-
enter the forecast by mid to late week, as model consensus
supports a slow moving front approaching from the north, in
concert with southwest CONUS cutoff low finally ejecting to the
east.
&&
.AVIATION...(For the 06Z TAFS through 06Z Friday night)
Issued at 1126 PM CDT Thu Sep 15 2016
Aviation concern will be storm chances overnight through Friday.
Storms over north central KS have pushed out some outflow that is
finally allowing storms to work south. In addition, mid level
theta-e advection will increase over central KS in the next few
hours. So, should see an overall increase in storms over central
KS through 09z. The tough question is how far south convection
makes it. For now will tempo storms at KRSL-KGBD-KSLN out of the
gate and VCTS at the remaining sites due to lower confidence on
southward progression. While the synoptic front should stay over
mainly central KS Fri, there should be some outflow over south
central or southeast KS. So, these features should provide a
couple different opportunities for storms on Fri with low
confidence on the areal extent.
&&
.PRELIMINARY POINT TEMPS/POPS...
Wichita-KICT 82 63 82 63 / 50 40 10 20
Hutchinson 80 60 82 61 / 50 30 10 20
Newton 79 61 81 61 / 50 30 10 20
ElDorado 80 63 82 61 / 50 40 10 10
Winfield-KWLD 82 64 83 63 / 50 50 10 20
Russell 78 56 81 59 / 20 10 10 20
Great Bend 78 56 82 59 / 20 10 10 20
Salina 80 59 82 60 / 50 20 10 20
McPherson 80 59 81 60 / 50 20 10 20
Coffeyville 83 66 84 63 / 50 50 20 20
Chanute 81 65 82 62 / 50 50 20 10
Iola 80 64 82 61 / 50 50 20 10
Parsons-KPPF 82 65 83 63 / 50 50 20 10
&&
.ICT Watches/Warnings/Advisories...None.
&&
$$
SHORT TERM...ADK
LONG TERM...ADK
AVIATION...RBL
Area Forecast Discussion
National Weather Service Lincoln IL
308 AM CDT FRI SEP 16 2016
.SHORT TERM...(Today and tonight)
ISSUED AT 306 AM CDT Fri Sep 16 2016
Today into tonight has the potential to be one of the wetter periods
across central and southeast Illinois for the next week. Therefore,
rainfall chances and timing are the primary forecast concerns.
A vigorous upper-level low is spinning across the northern Plains.
Additional weakener impulses are embedded within the southwest flow
ahead of this upper low and associated troffing. The surface cold
front associated with this system should stay to the north/west of
the forecast are for the bulk of the period, although it may begin
to push into western portions of the forecast area before daybreak
Saturday.
The explicit timing of the showers/storms ahead of the front will
prove quite difficult, as it is not very well agreed upon by the
model guidance. Expect some of the upstream convection (coming
mainly out of Iowa), or some of the more recent development (coming
out of Missouri) to push across much of the area today. However, it
should tend to diminish as it outruns the surface front and better
forcing by afternoon. Chances should increase again tonight as the
front draws closer and nocturnal low-level jet increases.
Shear/instability profiles are forecast to remain modest through the
period, suggesting a pretty low threat for severe storms.
&&
.LONG TERM...(Saturday through Thursday)
ISSUED AT 306 AM CDT Fri Sep 16 2016
A cold front will make slow progress across Illinois on Saturday,
possibly only reaching I-57 by 7 pm. The latest HPC frontal position
forecast actually lags the front back at the Illinois river at 7 pm
Saturday. Regardless of how far east the front moves on Saturday, it
will be losing is frontal circulation through the day as it becomes
parallel to the upper flow. Therefore, the precip chances should
wane with time from northwest to southeast on Saturday. Have kept a
band of likely PoPs Saturday morning southeast of a line from
Effingham to Paris, with chance PoPs as far NW as the Illinois River
Valley.
There will not be a significant airmass change as we head into
Saturday night, however, due to the cold front not making a clean
departure to the east-southeast. A few showers may continue south of
I-70 Saturday evening, per the GFS and ECMWF, but the GEM indicates
dry conditions in central and southeast IL by 7 pm Saturday.
Once the front dissipates or departs to the east Saturday night into
Sunday, high pressure should provide dry weather with mostly clear
skies. High temps will not change much from Saturday to Sunday, with
upper 70s to low 80s each day. Some warming is expected on Monday as
the next low pressure system moves along the Canadian border and a
cold front approaches IL. Highs should climb into the lower 80s
Monday. Some low rain chances return late Monday afternoon and
Monday night mainly north of I-74 as a weak cold front brushes our
forecast area. That front looks much more progressive in the
ECMWF/GFS/GEM models, with high pressure providing dry conditions by
Tuesday morning. The break in the rain should continue through
Wednesday. However, a 500 mb shortwave and developing warm front in
western Illinois will bring slight rain chances north of I-72 for
Wed night and Thursday.
Temps will remain above normal for Wed and Thurs, with highs in the
low 80s and lows in the upper 50s to low 60s.
&&
.AVIATION...(For the 06Z TAFS through 06Z Friday night)
Issued at 1108 PM CDT Thu Sep 15 2016
Satellite and radar trends are showing a longer delay of onset for
our showers and storms. The latest HRRR and RAP show nearly no
activity in our western forecast area until after 09z/4am, which
looks reasonable based on sat/radar. There are differing solutions
to the progression of storms during the morning, with the RAP
indicating a line of convection advancing from west to east
between 09z and 14z then stalling just southeast of the I-72
corridor. The HRRR indicates spotty storms until 15z, then
develops a line from SPI to CMI from 16z-17z in the last hour of
its valid time. The GFS/ECMWF/GEM/NAM seem to support RAP
solution, so will trend that way with storm timing in the 06z
TAFS. The cold front is projected to finally arrive after the end
of this TAF valid period 06z Friday night. That will set the stage
for prevailing surface winds to remain SE to S for the next 24
hours.
Forecast soundings indicate VFR cloud conditions should prevail
outside of thunderstorms. Some MVFR ceilings and VIS are likely
during heavier rains/storms, with IFR possible.
&&
.ILX Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...Bak
LONG TERM...Shimon
AVIATION...Shimon
Area Forecast Discussion
National Weather Service Indianapolis IN
425 AM EDT FRI SEP 16 2016
.UPDATE...
Aviation section has been updated below.
&&
.SYNOPSIS...
Issued at 301 AM EDT Fri Sep 16 2016
Chances for rain will increase across the area today into tonight
and continue into Saturday as a frontal system approaches the area.
Drier conditions will return to the area by Monday and should
continue into next week. Temperatures will be above average into
next week.
&&
.NEAR TERM.../Today/
Issued at 301 AM EDT Fri Sep 16 2016
The early morning should continue to be dry with thunderstorms
across Iowa moving northeast, and the rain across Missouri having
dissipated.
During the morning surface flow will become more southerly and flow
at 850mb will increase from the southwest. This will bring more
moisture and eventually lift into the area. This will continue
during the afternoon, and upper heights will begin to fall as an
upper trough approaches.
The result will be increasing chances for rain today. For now have
kept PoPs in chance category given some uncertainty in timing and
where best forcing will be.
Stayed with a model blend for high temperatures.
&&
.SHORT TERM.../Tonight through Sunday night/
Issued at 301 AM EDT Fri Sep 16 2016
Focus is on chances for rain through the period. Overall the models
are close enough for a continued use of a blend.
HRRR and 00Z ECMWF, and to some extent the NAM, are showing a
relative lull in rainfall coverage during the evening hours. With
better height falls overnight, and an upper jet approaching later
tonight, this seems reasonable. Will thus lower PoPs a bit during
the evening. However the aforementioned features will combine to
produce rain overnight, so went with likely to categorical PoPs all
areas.
Forcing will continue into Saturday morning then the focus should
shift to the southeast some as forcing from the stronger part of the
upper trough moves out of the area. Will allow PoPs to fall back
into chance category north during the afternoon.
Main forcing will move off to the east Saturday night into Sunday,
but the cold front itself will lag behind. Will continue to
gradually lower the PoPs from northwest to southeast through Sunday,
finally going dry Sunday afternoon as the front moves through.
Stuck with a model blend for temperatures.
&&
.LONG TERM /Monday through Thursday/...
Issued at 301 AM EDT Fri Sep 16 2016
It will be dry with warmer than normal temperatures Monday through
Thursday as an upper ridge over the central U.S. builds east across
our region. Will continue a slight chance of a thundershower across
the northwest half of our region Monday night as a weak cold front
moves our way and dissipates.
The rest of the long term period will be dry with high pressure
across the area.
High temperature`s will be in the lower 80s most areas with some
areas in the middle 80s by next Thursday as 850 MB tempertures
become a little warmer. Lows will be mostly in the 60s...except
upper 50s Tuesday night. In most cases stayed close to super blend
temperatures.
&&
.AVIATION /Discussion for 160900z KIND TAF Update/...
Issued at 425 AM EDT Fri Sep 16 2016
Minor tweaks made to KIND TAF to better match current conditions.
No other changes are needed at this time.
Previous aviation discussion follows... Good confidence that VFR
conditions will dominate through 18z or so.
Then, could see MVFR conditions in thunderstorms at times through
tomorrow night as a cold front approaches from the northwest and
upper waves interact with an increasing moist and unstable
atmosphere.
East winds less than 10 knots overnight will become southeast and
south this afternoon.
&&
.IND Watches/Warnings/Advisories...NONE.
&&
$$
SYNOPSIS...50
NEAR TERM...50
SHORT TERM...50
LONG TERM....JH
AVIATION...TDUD/JH
AREA FORECAST DISCUSSION
National Weather Service Jackson KY
430 AM EDT Fri Sep 16 2016
.SHORT TERM...(Today through Saturday)
Issued at 315 AM EDT FRI SEP 16 2016
A surface ridge resides across the Appalachian region this
morning, with widespread convection ongoing across the plains
associated with a mid level trough working eastward across the
region. The high pressure ridge will slowly erode through the day
today with some slow height falls expected across eastern Kentucky
by this afternoon. Strong heating, combined with an uptick in
850-700mb RH will lead to some shower/storm development along the
escarpment near the Cumberland Plateau region. HRRR has been
consistent now over 5 runs showing good coverage in showers and
storms this afternoon and evening. Meanwhile, NMM/ARW show very
little, although there is some convection, just not in that
region. The operational models (NAM/GFS/ECMWF) all show some
support for the development across our south central/southern
Kentucky today. With that in mind, have opted to go more
aggressive with the pops across this region today, going with
scattered to numerous coverage on showers and storms. This could
be the first measurable rain for London this month, so certainly
some beneficial rains if they occur as models advertise. If the
coverage indicated on the HRRR is correct, pops may need to go
higher this afternoon. Unlike the past few days, southwest flow
should keep things moving and prevent the potential for 1+ inch
rainfall potential. However, some brief heavy rain is still
anticipated. As the afternoon/evening progresses activity should
move northeast with the mean flow along any outflow from previous
convection. Eventually as instability drops off later this
evening, convection should begin to subside, but may linger on
past 7 or 8 pm before fading away. Best chances will stay across
southern and southeast Kentucky, but a few showers or storms could
impact much of the area. Thus, will even allow for some isolated
pops in the north. Highs today will soar well into the 80s to
around 90, helping to spark the afternoon/evening convection.
Tonight, we should see a lull as the main shortwave trough remains
to our northwest with a vort max spreading northeast into the
great lakes. However, the low level jet over the region, could
spark a shower/storm or two late tonight, mainly across northern
or northeast Kentucky. Saturday will feature another warm day with
highs again well into the 80s. Forcing remains weak or non-
existent through the day, so shower/storm coverage may be more
isolated, but the better rain chances will increase back to the
northwest closer to the mid level trough.
.LONG TERM...(Saturday night through Thursday)
Issued at 415 AM EDT FRI SEP 16 2016
The period is expected to begin with a shortwave trough moving
across the Great Lakes and from the Plains and into the OH and TN
Valleys and the Appalachian region. The axis of this trough
should move east of the area by late Sunday night or early on
Monday. Then, height rises should ensue through midweek with upper
level ridging building into the southeastern states and remaining
in place and dominant through the end of the period. At the sfc, a
cold front should move across the area from Sunday afternoon into
Sunday night. Surface high pressure should build in behind the
front for Monday. A shortwave moving through the Great Lakes
should push a weak cold front into the OH Valley from late Tuesday
into Wednesday. However, this front will wash out or become
diffuse over the area and should produce little more than an
increase in mid level clouds or cu. Another sfc high will build
into the area behind this boundary and remain in place through the
end of the period.
The most active portion of the extended period will be from
Saturday night into Sunday night as the cold front and shortwave
trough approach and then move across the area. This combination
should produce showers and a few thunderstorms across the area
during that period. The highest chances will be on Sunday when
daytime heating should bring enough instability for the greatest
coverage. Otherwise, the Monday through Thursday period should be
dry with above normal temperatures with no more than afternoon
cumulus each day as high pressure dominates.
&&
.AVIATION...(For the 06Z TAFS through 06Z Friday night)
ISSUED AT 125 AM EDT FRI SEP 16 2016
Valley fog will be a concern over the next 6 hours with the best
chances in the eastern valleys where dewpoints did not mix out
quite as well today. Thus, the fog may creep into the big sandy
airport overnight, with some light fog possible at Morehead.
Much drier air mixed down at Somerset and London and should limit
fog potential there. Jackson is a borderline situation, but opted
to leave fog out as it may not quite make it up to the ridge top.
Fog will quickly burn off Friday morning. VFR conditions will then
be seen through the remainder of the period, although an isolated
shower or storm could impact the area. Too much uncertainty on
this to include in the TAFS presently.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...KAS
LONG TERM...JP
AVIATION...KAS
Area Forecast Discussion
National Weather Service Saint Louis MO
336 AM CDT FRI SEP 16 2016
.SHORT TERM... (Through Late This Afternoon)
Issued at 334 AM CDT Fri Sep 16 2016
Still some confidence issues with how and where the storms will
develop today. Complex of storms extend from southern Iowa
southwestward to northwestern Missouri and eastern Kansas as of 08z.
In the meantime, scattered showers trying to pop up over
northeast/central down to southwestern Missouri, but little if any
of it is reaching the ground at the moment. HRRR models want to
develop storms over the next several hours, mainly north of I-70,
then eventually spread across majority of forecast area by 12z,
while complex to our north weakens. Will blend a bit of reality and
models for pops today, but did keep likely pops for most locations
at some point today. Won`t see an all day rain, but with plenty of
clouds and some rain, temperatures will struggle to warm up, so have
highs in the upper 70s to mid 80s.
Byrd
.LONG TERM... (Tonight through Thursday)
Issued at 334 AM CDT Fri Sep 16 2016
(Tonight - Sunday)
Expect TSRA to be ongoing at the beginning of the period across the
sern half of the CWA, roughly along and SE of a K3LF to KSTL to KVIH
line. An ULJ back-building into the region as well as an approaching
s/w shud support TSRA into the overnight hrs with help from an
increasing swly LLJ. Uncertain what coverage of TSRA near the actual
cdfnt will be like. Better low level forcing will remain further
south as mentioned above. The ECMWF suggests some ULJ coupling which
may support better coverage near the fnt, but this soln seems to be
an outlier. Still, think sct coverage is reasonable and have
therefore kept chance PoPs going near the fnt.
While the TSRA mentioned above shud push the effective sfc boundary
south of the CWA, the actual cdfnt will still be pushing swd thru
the region. Have kept PoPs in morning vs. afternoon with some
uncertainty in timing, but in general, morning convection shud
continue moving out of the region with any activity along the fnt
dissipating. Expect breaks in clouds to develop allowing some
recovery south of the cdfnt and redevelopment during the afternoon
hours. However, if these breaks do not occur, a dry fropa is
entirely possible. The GFS soln seems to suggest enuf CAA with the
805mb cdfnt that light RA will be possible much of the day. This
soln seems to be an outlier attm, but will keep in mind for future
updates.
With the fnt south of the CWA Sat night, the remainder of the period
remains dry.
As for temps, kept warmer trend going for tonight and Sat as the
region remains south of the fnt. Trended cooler for Sat night thru
Sun as the sfc ridge settles into the region.
(Monday - Thursday)
Temps shud warm quickly on Mon as the sfc ridge builds ewd. However,
this appears to be short lived as another cdfnt shud reach the
region by Mon night into Tues. Can not rule out precip along this
fnt, however, it appears best forcing will remain well north of the
region with the main upper trof over the Great Lakes and low level
forcing well out ahead of the fnt.
Temps shud warm again by mid-week as the upper ridge builds into the
region. Mdl solns differ somewhat with the GFS breaking down the
ridge sooner. Have kept PoPs low thru the end of the period, but
believe the upper ridge will remain in place a bit longer, keeping
the sfc fnt and the associated precip north of the area.
Tilly
&&
.AVIATION... (For the 06z TAFs through 06z Friday Night)
Issued at 1159 PM CDT Thu Sep 15 2016
Light fog has developed across parts of the region, particularly
in areas which received rainfall earlier today and where winds
were nearly calm. Convection across KS/NEB/IA will sink
southeastward overnight, likely reaching KUIN within the next few
hours followed by KCOU/KSTL/KSUS/KCPS a few hours afterwards. A
second round of SHRA/TSRA is expected during the afternoon hours,
but there is low confidence regarding the timing. Winds will
remain southeasterly to southerly through the period ahead of an
approaching cold front.
Kanofsky
&&
.PRELIMINARY POINT TEMPS/POPS...
Saint Louis 82 70 84 63 / 60 60 40 10
Quincy 80 66 81 57 / 70 50 30 10
Columbia 79 65 81 59 / 70 50 30 10
Jefferson City 80 65 82 60 / 70 50 30 10
Salem 83 69 83 62 / 60 70 60 30
Farmington 83 68 83 62 / 60 70 60 30
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...None.
IL...None.
&&
$$
WFO LSX
Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
432 AM CDT FRI SEP 16 2016
.SHORT TERM...(Today and tonight)
Issued at 433 AM CDT Fri Sep 16 2016
Early morning water vapor imagery paired with 500mb heights
indicates a cut off upper low over North Dakota and widespread
thunderstorm activity ongoing across parts of Kansas and Nebraska.
An active period ahead as we move this upper low through the area
today and tonight.
At the surface, low pressure across the eastern Dakotas yielded
southerly flow across our area with increasing moisture and
dewpoints in the low 60s. As the upper low pushes east today, we`ll
see the vorticity maxima rotating through. Out ahead of it, showers
and a few storms will develop, and mostly be focused across northern
MN into central MN where the lift and mid level lapse rates are best
owing to the upper low moving through that area.
The upper low will make it to Lake Superior by tomorrow morning,
which means central MN through northwestern WI will be the most
susceptible to showers moving through tonight within the close
proximity to the low. Thunderstorms are possible today but severe
weather is generally not expected at this time. Temperatures will
increase into the low to mid 70s and dewpoints into the mid 60s this
afternoon.
.LONG TERM...(Saturday through Thursday)
Issued at 433 AM CDT Fri Sep 16 2016
The first half of the long term forecast looks to feature mostly
dry weather and then finishes off with a decent potential for
showers and thunderstorms Wednesday through Friday.
Weak surface ridging will be present on Saturday, although cold
air advection in the cyclonic flow regime with the trough to the
northeast will yield stratus cloud cover over the area and
possibly a few showers and isolated (afternoon) thunderstorms over
Wisconsin. The cloud cover and cool flow will yield cooler than
normal high temperatures in the mid 60s to lower 70s.
By Sunday the ridge slides off to the east and southerly return
flow ensues. Highs will respond accordingly with decent mixing
yielding lower 70s (western WI) to lower 80s (western MN).
On Sunday night a low level jet of 40 kts and a weak mid level
impulse could generate a few showers and thunderstorms from
central/southern MN into western WI. For the most part however forcing
is displaced to the north given the jet dynamics are along the
International border. Slightly better chances arrive on Monday
afternoon/eve as a cold front passes during peak heating, although
moisture looks pretty scarce in the lower levels.
For the last part of the week, GFS and ECMWF models develop an
upper low over the Pacific Northwest, along with an associated
lee-side surface low over the Northern Plains. Given the
prolonged potential for a front in the area along with continued
southwest flow, there could be a heavy rain & severe threat
between Wednesday & Friday.
&&
.AVIATION...(For the 06Z TAFS through 06Z Friday night)
Issued at 1124 PM CDT Thu Sep 15 2016
Bulk of the precip has shifted off to the E and S, resulting in
low stratus taking center stage as the main issue for the
overnight hours through daybreak. Have already seen visibilities
drop to around 1SM at some sites with VV002, mainly where sites
have gone calm. As the precipitation shifts E, similar conditions
will impact KMSP and the WI TAF sites. Precipitation chances have
diminished greatly per HRRR and other local models so have scaled
back the precipitation mention at all TAF sites, including not
having CB/TS anywhere due to low confidence in timing/placement.
Conditions look to improve to VFR by tomorrow afternoon as winds
shift from S to W with the cold frontal passage late day tomorrow.
KMSP...Have indicated conditions dropping to IFR prior to daybreak
then remaining there through late morning. Ceilings will steadily
improve but may well remain below 1700 feet through midday. The
timing may change since the drop in ceilings is splotchy on IR
satellite imagery both locally and upstream. Otherwise, not much
difference locally for MSP compared to other TAF sites per the
discussion above.
/OUTLOOK FOR KMSP/
Sat...VFR. WNW wind 5-15 kt.
Sun...VFR. S wind 5-10 kt.
Mon...VFR. SW winds 5-10 kt...becoming NW.
&&
.MPX Watches/Warnings/Advisories...
WI...None.
MN...None.
&&
$$
SHORT TERM...SPD
LONG TERM...LS
AVIATION...JPC
Area Forecast Discussion
National Weather Service Morristown TN
357 AM EDT FRI SEP 16 2016
.SHORT TERM (Today and Tonight)...
Surface ridge extending southwest from New England across the
Middle Atlantic into East Tennesse will begin to shift east today.
With it, a return to southerly low level flow across much of the
area will start bringing a bit more moisture back into the area.
With 500 mb heights rising slightly ahead of an approaching weekend
shortwave trough, high temperatures will again reach into the 90`s
across much of the East Tennessee Valley. Combination of increasing
low level moisture and slightly building heights aloft will once
again confine bulk of diurnal convection to elevated terrain. In
agreement with latest HRRR model, best combination of instability
and moisture is found in the northern Plateau by afternoon and
looks to be the most likely area to see afternoon convection.
With dew points starting to rise, expect overnight lows to also
climb back above climatology ranging from the lower 60`s in SW VA
to near 70 in SE TN. Both daytime highs and overnight lows are
about 4-5 and 1-2 degrees respectively above MOS guidance, that is
struggling to handle the September heat.
.LONG TERM (Saturday through Friday)...
Upper level ridge that has been dominant across the Forecast area
finally breaks down Saturday night and Sunday allowing a shortwave
and associated cold front to move through Sunday and Sunday night.
A few showers and storms will develop during the heat of the day in
southwest Virginia and higher elevations of the Appalachians...
Smokies and plateau Saturday afternoon and evening. The actual cold
front will not approach until early Sunday and then be east of the
Forecast Area Monday morning. Best chance for precipitation will be
just ahead of front Sunday and Sunday evening. Some areas in
western sections may get over one half inch Sunday but eastern
areas less than one half inch mainly Sunday night. Went a couple
degrees above guidance Saturday which will be mid 80s northeast to
around 90 or lower 90s southeast. Another mild night Saturday night
with partly to mostly cloudy skies. Sunday reluctant to drop
temperatures much but will depend on how fast pre frontal clouds
move in. On Monday air mass will be drier but Upper level ridging
starts to move back in from the west and stays centered over the
eastern Tennessee valley through the extended period. Not much
relief from the hot weather. Highs still could reach 90 in the
central and southern valleys and 80s elsewhere. Still several
degrees above normal.
&&
.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN 94 70 90 70 / 10 10 10 10
Knoxville McGhee Tyson Airport, TN 92 67 89 68 / 10 10 10 10
Oak Ridge, TN 92 68 89 69 / 10 10 10 10
Tri Cities Airport, TN 90 63 86 63 / 20 10 10 10
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...None.
TN...None.
VA...None.
&&
$$
EJH/TD
Area Forecast Discussion
National Weather Service SAN ANGELO TX
331 AM CDT FRI SEP 16 2016
.SHORT TERM...
(Today and Tonight)
Mesoscale convective complex continues to roll across the Big
Country early this morning, moving east at a decent clip. Large
shield of rain on the back side will be slow to decrease, so highest
rain chances for the first period will actually be with whatever is
left at sunrise this morning. HRRR suggests that additional
convection may develop along the southern flank as the outflow moves
south, perhaps into the Concho Valley and Heartland as well. Have
increased first period PoPs for this possibility, but will continue
to monitor. Will almost certainly need to update PoPs across many
areas based on radar trends as we get closer to sunrise. After the
morning convection ends, wherever the outflow ends up should be an
additional focus for more showers and storms this afternoon.
Models suggest another similar situation for tonight as well, with
more showers and storms developing to the west and tracking east
across mainly the northern half of the area. Given how poorly the
models have handled this mornings convection, hate to jump on the
possibilities for tonight. Left the PoPs in the chance range for
tonight, and see if later data and pinpoint locations a little
better.
.LONG TERM...
(Saturday through Thursday)
An upper level low will be located offshore the northern coast of
Baha California on Saturday, while an upper level ridge across South
Texas begins to build. This will keep West Central Texas in a
general west flow aloft. There are a hints of a weak disturbance
moving across the region Saturday, resulting in scattered showers
and thunderstorms mainly across the Big Country. In addition a weak
cold front is forecast to be across the South Plain/Red River, but
at this time is expected to remain north of our area. Given the lack
of upper level forcing and uncertainty on the timing and strength of
the possible disturbance, PoPs were kept in the 20-30 percent range
across the area. A few storms may linger into the evening hours,
with most convection dissipating by late evening.
The aforementioned upper level ridge will begin to build over much
of Texas, including West Central Texas, Sunday through the middle of
next week. Isolated showers and thunderstorms cannot be ruled on on
Sunday, and slight chance PoPs were retained. Otherwise, expect a
mainly dry forecast for the upcoming work week. Highs on Sunday and
Monday will be well above seasonal normals, mainly in the mid 90s,
as the upper level ridge centers itself over the region. The center
of the ridge is eventually forecast to move toward the Mid/South
Atlantic Coast, which should result in slightly cooler temperatures
for West Central Texas.
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 90 70 90 71 / 30 50 30 20
San Angelo 93 69 92 71 / 20 30 20 10
Junction 94 68 93 70 / 10 20 20 10
Brownwood 91 71 91 71 / 20 40 30 10
Sweetwater 91 67 87 70 / 40 50 30 20
Ozona 90 71 92 70 / 20 20 20 10
&&
.SJT Watches/Warnings/Advisories...
None.
&&
$$
07/Daniels
AREA FORECAST DISCUSSION
National Weather Service Topeka KS
257 AM CDT FRI SEP 16 2016
.SHORT TERM...(Today and tonight)
Issued at 256 AM CDT Fri Sep 16 2016
Early this morning an outflow boundary, generated from more intense
storms last evening across west central KS and south central NE, was
moving southeast across the CWA and at 230 AM extended from near
Holton, southwest to Alma, then southwest to Hope. Isentropic lift
north of this boundary was causing numerous showers and scattered
elevated thunderstorms to develop across most areas northwest of the
outflow boundary. WV satellite showed an intense upper trough across
central ND and western SD with a trough axis extending southward
into western NE and northeast CO.
The higher resolution models such as the WRF and exp-HRRR forecast
the broad area of showers and thunderstorms across much of the CWA
to weaken by 12Z and rapidly shift southeast across the CWA through
the mid morning hours. The WRF and HRRR show the front moving
through most of the CWA dry early this afternoon with a line of
thunderstorms developing along the front after 21Z just to the
southeast of the CWA.
The NAM, GFS and ECMWF show the widespread showers and thunderstorms
across the northern and western half of the CWA to continue to
expand southeast and continue into the afternoon and evening hours
ahead of the the surface front and upper trough translating east
across the northern and central plains.
At this time I kept likely POPs this morning across much of the CWA,
with POPs decreasing across north central KS during the mid and late
morning hours. I kept chance POPs going across the CWA through the
afternoon hours and into the night across east central KS. If the
higher resolution models are more accurate, then POPs may be much
lower across the CWA during the afternoon hours with dry conditions
into the evening.
There is a risk for isolated flooding if some areas, if training of
showers and thunderstorms develop through the morning into the
afternoon hours. Though most guidance forecast QPF to remain below a
half inch. The areas to watch will be far northeast KS where heavy
rainfall occurred Tuesday night into Wednesday morning.
Highs Today will reach the mid to upper 70s but if the rain
continues through the day across northeast and east central KS, then
high temperatures may be cooler. Overnight lows will be slightly
cooler behind the front with mid to upper 50s across north central
KS and lower 60s across east central KS.
.LONG TERM...(Saturday through Thursday)
Issued at 256 AM CDT Fri Sep 16 2016
By Saturday morning, the upper level trough will be located over the
northern Great Lakes with the associated cold front extending down
into southern Oklahoma. Surface high pressure will move into
northeast Kansas later in the morning, providing clearing skies and
light winds through the day Saturday. Overall, a dry weekend and
early work week look to be in store, with the next chances for
precipitation beginning Wednesday and continuing until the end of
the period. Models continue to not be in very good agreement toward
the end of the period about a upper level trough tracking over the
northern CONUS, so confidence in PoPs right now is below average.
Temperatures look to be near climatology on Saturday and Sunday with
a warmup beginning by Monday where highs are forecast in the upper
80s and staying near the mid 80s through the week.
&&
.AVIATION...(For the 06Z TAFS through 06Z Friday night)
Issued at 1145 PM CDT Thu Sep 15 2016
Chances for thunderstorms remain on track to increase in the next
several hours as a cold front approaches. Both model and radar
trends suggest nailing down any specific time is difficult. Have
kept with VCTS for several hours, with front passing around 22Z
rapidly diminishing precip chances.
&&
.TOP Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...Gargan
LONG TERM...Heller
AVIATION...65
Area Forecast Discussion
National Weather Service Tulsa OK
409 AM CDT FRI SEP 16 2016
.DISCUSSION...
The latest runs of the experimental HRRR suggest that convective
complexes across Kansas and northwest Texas will merge later this
morning and affect parts of mainly northeast Oklahoma and
northwest Arkansas later this morning into this afternoon.
Additional convection may develop this evening and overnight as a
weak frontal boundary sags south into the area. One last chance of
showers and thunderstorms will occur late Saturday night and
Sunday as a weak upper level disturbance moves across the area.
Clouds and precipitation will tend to hold daytime temperatures
down a bit through this weekend, but most places will remain a few
degrees above the seasonal normals.
An unseasonably strong ridge of high pressure will build over the
area next week and will result in much above normal temperatures,
with little chance of any rainfall. Current forecast temperatures
may be conservative for much of next week, with 90s looking
likely for much of eastern Oklahoma and west central Arkansas each
afternoon. The upper ridge will break down late next week into the
following weekend, which may finally allow a more significant cold
front to drop south across the area
Stayed close to guidance temperatures the next couple days.
&&
.PRELIMINARY POINT TEMPS/POPS...
TUL 86 68 87 65 / 60 50 20 20
FSM 90 70 90 69 / 60 40 30 10
MLC 89 69 89 67 / 50 50 30 20
BVO 85 65 86 61 / 70 50 20 20
FYV 84 65 85 62 / 60 50 30 10
BYV 84 65 84 63 / 60 50 40 10
MKO 87 68 87 66 / 60 50 30 20
MIO 84 66 85 62 / 70 60 20 10
F10 88 68 88 67 / 50 50 30 20
HHW 91 71 91 70 / 40 30 30 10
&&
.TSA Watches/Warnings/Advisories...
OK...None.
AR...None.
&&
$$
SHORT TERM...10
LONG TERM....05
PLATE
Area Forecast Discussion...UPDATED
National Weather Service Albuquerque NM
610 AM MDT FRI SEP 16 2016
.AVIATION...
12Z TAF CYCLE
Some patchy MVFR and perhaps isolated IFR conditions to be
ongoing through 15Z or 16Z across the east central and se
plains and even in a few locales across the adjacent highlands
to the west. Also short-lived MVFR conditions can be expected
in/near storms this aftn/eve across roughly the east half of the
state. Terminals most likely to be impacted by storms today are
KLVS, KROW and KTCC, ranking for the most part in that order in
the likelihood of occurrence. Other than these exceptions VFR
conditions are expected to persist. An weak to moderate east
canyon/gap wind will likely develop this evening and impact
KSAF and KABQ, and may be a little stronger than forecast model
guidance currently indicates. Both storms in the east and the
central valley gap wind will diminish between about 06Z and 11Z.
43
&&
.PREV DISCUSSION...340 AM MDT FRI SEP 16 2016...
.SYNOPSIS...
A back door cold front will provide the focus mechanism for
scattered to numerous showers and thunderstorms along and east of
the central mountains today. Another round of severe weather is
expected and will favor the east slopes of the Sangre de
Cristos...east central and southeast plains. The atmosphere will
begin to dry this weekend and also gradually warm as a low cuts
off well to the west of the state. The cut off low and subtropical
high will work in unison to usher abundant moisture northward
during the earlier half of next week. The moisture increase is
expected to favor the western half during this period although
expect some changes in the forecast as we get closer to that event
period.
&&
.DISCUSSION...
Main focus and forecast challenge today will be the back door
cold front position as it rapidly pushes south and westward. The
current frontal position which shows up on radar near I40 between
TCC and CQC appears to be a few hours fast compared to boundary
layer flow forecasts from the NAM/GFS. The latest RUC and
mesoscale models appear to have a better handle on it. Decided to
adjust highest PoP`s to reflect where the best sfc convergence and
upslope would be found. This boundary will also serve as a focus
for some severe weather. Shear...both directional and speed...
appear to be more than adequate while the higher CAPE values will
be largely dependent on the frontal intrusion. Dewpoints are lower
overall behind the frontal passage. Latest NAM appears to have a
better handle in the boundary layer moisture field than GFS. Both
models appear to forecast the stronger than normal subtropical
jet max position fairly well and will aid lift across portions of
the forecast area this afternoon/evening.
Models continue to show a drying trend for this weekend. Residual
frontal impacts and jet max exit region should produce scattered
storms across the east on Saturday. A drier southwest flow should
occur from west to east as the weekend progresses and lower
coverage patterns overall. Temperatures would begin to warm during
this period.
A pesky cut off low which is currently showing up in the satellite
data combined with a building subtropical high will be the main
weather drivers during at least the earlier half of next week.
Models have had a hard time dealing with this low and that is to
be expected. Thus a lower confidence period. Either way...still
looking for a moisture subtropical flow to develop over portions
of the forecast area during this period. It appears western areas
would remain favored. Some uncertainty as to how much moisture
would flow northward. The ECMWF and Canadian show some sort of
tropical tap from a system or wave that develops off the Mexican
coast. Current water vapor imagery shows some evidence of that
development so leaning towards the ECMWF/GEM. The GFS has been
trending this way somewhat past couple of runs. So some confidence
building there although still quite a bit of uncertainty. Despite
the heavier rainfall chances...sfc high temps appear to be above
normal due to higher than usual 700 mb temps.
The rest of next week will largely be determined by the evolution
of the cut off low translation as well as the next long wave
trough. Too early to say about drier westerlies vs some sort of
pseudo subtropical tap.
50
&&
.FIRE WEATHER...
While roughly the west third of NM will see very little to no
shower and thunderstorm activity today and Sat, there will still
be a good to excellent chance of same across the east half of the
state today and a decent, though a little lower, lingering chance
again Sat. Both afternoons and evenings there is once again a
risk of strong to even severe storms plus locally very heavy rain
across the east third to nearly half of the state. Across the
approximately west third of the state enough dry air will nudge
in to lower minimum RH near or below 15 percent and boost Haines
indices into the 5 to 6 range. All this will come about due to
the intrusion of quite dry air through a deep layer of the
atmosphere into that part of the state. A fairly weak back door
cold front will make some further progress south and to some
degree west across the east half of the state through the day
today. This will inject some additional low lvl moisture into
that part of the state and also help provide some extra focus for
storm development. The ventilation categories will generally
range from poor to fair today east of the central mtn chain,
though a few rather small pockets there may reach the good
category. Farther west will be good to excellent ventilation.
Pretty much all locales will see good to excellent rates Sat
and Sun.
It looks even more likely now that as the weekend progresses the
upper low developing west of NM will retrograde southwestward to
off the Baja Peninsula coast, while a moderate strength high
pressure ridge aloft will develop across west NM and east AZ.
This will dry the air mass out further across NM. Showers and
storms will be unlikely on Sun and Mon, though slight chances
have been kept in fcst for far south to southwest portion of the
fcst area. Widespread Haines of 4 plus is expected Sun and Mon
with 5 and 6 values covering more area Mon compared to Sun. as
daytime temps warm to a few to several degrees above normal
values for this time of year.
The Tue to Thu period of the coming work week will usher in more
moisture and increasing shower and thunderstorm chances as the
Baja low gradually opens up and heads northeast into the SW U.S.
Temps will also begin to cool and Haines indices will trend
downward as the better moisture arrives.
43
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
Area Forecast Discussion
National Weather Service State College PA
1125 AM EDT FRI SEP 16 2016
.SYNOPSIS...
Dry weather will hold through Saturday morning thanks to high
pressure moving east of New England. Humidity will increase
tonight and Saturday ahead of a slow moving cold front that will
finally pass later Sunday. Temperatures will warm up for the
weekend before slipping back to near normal once again behind the
front.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Early visual satellite loops show the low clouds expanding north
and west. RAP low level RH fields indicate that the clouds should
begin slowly mixing out with at least partial sunshine developing
during the early to mid afternoon hours in most areas.
Highs will be quite pleasant once again...ranging through the 70s
which is very close to normal for this time of year.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/...
Eyes turn westward as moisture continues to increase ahead of slow
moving frontal system approaching from the Ohio Valley tonight and
Saturday. It appears that most rain will hold off east of the
Alleghenies until late Saturday afternoon or evening. Gradual
thickening of clouds is anticipated Saturday morning through early
afternoon...with showers arriving over the far west by midday and
slgt chc pops being introduced into the central mountains by early
afternoon. do not expect steady shower activity to arrive until
generally after dark Saturday evening across central and eastern
areas. Highs Saturday will be a few degrees warmer throughout...
ranging from the mid 70s north to the lower 80s southeast.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
Low pressure rolls through northern Ontario and Quebec early in
the period. But its associated cold front stalls in increasingly
parallel boundary layer and upper flow. The front finally pushes
through late Sunday. But Saturday night and Sunday look showery
for most. PW does not reach 2 inches, but the constant southerly
flow around the big high pressure off the coast will yield a long
period of deep moisture.
The first part of the new week looks dry as it is now, with a
surface high overhead. But, a very weak and moisture-starved front
moves along in the progressive westerly flow and could make a
passing shower on Tues or so depending on how fast it moves. But,
again, it holds almost no hope of rainfall for anyone, as the Gulf
is cut off and drought does beget drought. Dry for another few
days after that. Temps through the period will remain 5 to 10F
above normals for maxes and mins - and mins might be 10+ above
normal during the weekend with all the clouds and moisture.
&&
.AVIATION /15Z FRIDAY THROUGH TUESDAY/...
A wedge of low clouds stacked up against the terrain continues to
bring MVFR/IFR from JST-AOO northward. Still questionable whether
the low clouds will continue to back west and into BFD. Their
wind having gone more southerly may very well mark the westward
extent of the reduced conditions.
We still expect most terminals to improve to VFR by early to mid
afternoon.
A return of sub VFR conditions is likely again tonight into
Saturday morning as moisture begins to increase ahead of an
approaching cold front.
Outlook...
Sat-Sun...Scattered impacts as a slow moving frontal system moves
through the region.
Mon-Tue...no sig wx.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SYNOPSIS...La Corte
NEAR TERM...La Corte
SHORT TERM...La Corte
LONG TERM...Dangelo/DeVoir
AVIATION...La Corte
Area Forecast Discussion
National Weather Service Quad Cities IA IL
708 AM CDT FRI SEP 16 2016
.UPDATE...
Issued at 702 AM CDT Fri Sep 16 2016
Water vapor shows subsidence across Iowa which is helping to kill
the precip. Rap trends suggest the subsidence will weaken this
morning as another upper level disturbance approaches. The forcing
from this wave may be enough to regenerate precip late this
morning and into the afternoon. As a result, have trended pops
downward this morning for most areas.
Cloud cover raises concerns about high temperatures today. Sun
strength is the same as late March so temperatures could come in
lower than what is forecast. Will consider this scenario for a
possible later update.
&&
.SYNOPSIS...
Issued at 255 AM CDT Fri Sep 16 2016
06Z surface data has an inferred low east of KTVK. A boundary from
the thunderstorm complex ran from the MN/IA/WI border south between
KFFL and KMPZ and then west along the MO/IA border. Dew points were
in the 50s across the Great Lakes with 60s and 70s from the upper
Mississippi Valley to the Gulf Coast.
&&
.SHORT TERM...(Today and Tonight)
ISSUED AT 255 AM CDT Fri Sep 16 2016
Through sunrise, the bulk of the rain should remain over central
Iowa and the northwest parts of the area. Ahead of the main rain
area, isolated to scattered showers and thunderstorms will be
possible.
Starting around sunrise and continuing through mid-afternoon, the
overall forcing will increase across the area as the next upper
level disturbance moves east out of the Plains. Thus showers with
some thunderstorms should become more widespread across the area.
Cloud cover and precipitation may hold down temperatures today as
the sun strength is the same as late March.
Tonight, the next cold front will move through the area. Scattered
showers with some thunderstorms will be seen ahead of the front.
Precipitation will slowly end from west to east late tonight as the
better forcing moves east of the area.
.LONG TERM...(Saturday through Thursday)
ISSUED AT 255 AM CDT Fri Sep 16 2016
Generally slightly above to above normal temperatures with increasing
chances of precipitation late next week.
Long term forecast confidence...fair or average with main issue temperatures
diurnal ranges a bit underdone with most days highs slightly underdone
and mins may be 3 plus degrees or so too high due to longer days and
modest humidity.
Saturday and Saturday night...weak high pressure to bring near seasonable
temperatures and moderate dewpoints for nice early fall day. Highs mostly
in the 75 to 80 degree range and mins that night the lower to middle
50s with some upper 40s suggested in favored low lying areas along and
especially north of I-80 corridor.
Sunday and Monday...Warmer with highs mostly in the 78 to 84 degree
range and mins upper 50 to around 60 degrees. Low POPS suggested with
next front may be overdone for later shift to reassess due to limited
forcing and moisture.
Tuesday and Wednesday...Weak passing high presssure to result in possibly
slightly lower highs some locations but still mainly in the upper 70s
to lower 80s. Mins on Wednesday AM may be 3 degrees too high and Thursday
AM mins possibly a couple degree to mild.
Thursday and Friday...increasing clouds and chances of showers and storms
with timing and intensity still low. Highs still mostly in the upper
70s to lower 80s. Lows mostly within a few degrees of 60 degrees.
&&
.AVIATION...(For the 12Z TAFS through 12Z Saturday Morning)
ISSUED AT 637 AM CDT Fri Sep 16 2016
An upper level disturbance moving through eastern Iowa was
generating isolated to scattered SHRA/TSRA in eastern Iowa and
northern Illinois. Conditions range from MVFR to VFR with isolated
pockets of LIFR due to fog. Once the upper level disturbance moves
into the Great Lakes region, conditions should be VFR with
pockets of MVFR. Frontal passage after 06z/17 with VFR conditions
with pockets of MVFR conditions.
&&
.HYDROLOGY...
Issued at 255 AM CDT Fri Sep 16 2016
Rising river levels on a few eastern Iowa tributaries are expected
to continue due to runoff upstream from the past several days, and
because pockets of additional heavy rain tonight.
A Flood Warning has been issued for Conesville on the Cedar River
because confidence is high that minor flood stage will be reached
tonight.
A Flood Watch has been issued for both De Witt on the Wapsipinicon
River and Marengo on the Iowa River. Confidence remains low to moderate,
partially due to uncertainties on rainfall amounts through today. If
current trends continue, Wapello on the Iowa River may also require
a watch. It is important to monitor for forecast updates over the next
24-48 hours.
&&
.DVN Watches/Warnings/Advisories...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...08
SYNOPSIS...08
SHORT TERM...08
LONG TERM...Nichols
AVIATION...08
HYDROLOGY...Nichols
Area Forecast Discussion
National Weather Service Grand Rapids MI
1158 AM EDT FRI SEP 16 2016
LATEST UPDATE...
Hydro
.SYNOPSIS...
Issued at 328 AM EDT Fri Sep 16 2016
Yet another system will stream gulf moisture into the area
this afternoon into Saturday morning. This will result in periods
of showers and a few thunderstorms from mid afternoon into the
early morning hours of Saturday. Rainfall may be locally heavy
during this time. The cold front moving through the area later
Saturday may trigger a few more thunderstorms but these will be
more widely scattered and not all areas will see these storms.
Some clearing is expected Saturday night but there will an
isolated thunderstorm can not be ruled out Sunday afternoon either.
Dry air return Sunday night into Tuesday... then when the warm air
tries to push back expect another period of showers and
thunderstorms with unseasonably warm temperatures during the mid
week.
&&
.UPDATE...
Issued at 1104 AM EDT Fri Sep 16 2016
We have updated the forecast this morning to drop rain chances
some for this afternoon. We are still expecting some showers to
approach/develop this afternoon, especially across the West. The
initially dry air in place will take a bit to be overcome by the
increasing moisture transport this afternoon. This is evident in
the showers to our west this morning that have dried up as they
tried to move toward the area.
Thunder is still expected to become possible later this afternoon
and more so this evening. Most model fcst soundings indicate it
will take until 00z this evening for sufficient instability to be
present for thunder.
&&
.SHORT TERM...(Today through Sunday)
Issued at 328 AM EDT Fri Sep 16 2016
There are many issues to deal with for this forecast. Mostly this
means timing the convection into Southwest Lower Michigan and
figuring out just how much rain will fall between noon today and
mid morning Saturday.
Currently there is a weakening area of thunderstorms over Iowa
into western Wisconsin at 3AM this morning. This is largely
associated with the surge of deep moisture being pushed north 90
knot polar jet core over western Minnesota and a 40 knot low
level jet. There is also a southern stream wave tracking northeast
from Missouri. All of this surges into Southwest Lower Michigan by
mid afternoon. The latest runs of the RAP and HRRR show the
instability makes a stronger run at us than the models had
forecast yesterday. Also the 1000 to 850 moisture transport
vectors look more focused than they did yesterday. The high
resolution HRRR and RAP model and our time lagged ensembles (not
to mention the SREF) have likely to conditional pops for our area
by mid afternoon into tonight as all this happens. Our
precipitable water values approach record values for this time of
year so heavy rainfall is possible. The deep layer shear is weak
and with the extensive cloud cover I do not see severe storms as
much of a issue but one can not rule out gusty winds in the
stronger storms.
The upper level low that has been booted out of the Southwest
CONUS still remains as a closed upper low into Saturday morning
(stronger than previously forecast by the models)... so I would
think there would be a decent chance of thunderstorms with the
cold front Saturday afternoon. We should see some clearly Saturday
night but there is enough cold air at mid levels and with the
upper trough lingering Sunday... an afternoon thunderstorm can not
be ruled out so I put 15 to 20 percent pops inland for that.
.LONG TERM...(Sunday night through Thursday)
Issued at 328 AM EDT Fri Sep 16 2016
Fair weather is expected Sunday night with a ridge of high pressure
in control of the wx pattern. The next chance for rain will come
late Monday through Monday night as a fast moving upper level
disturbance and cold front approach from the northwest.
Fair weather will return behind that system Tuesday through Tuesday
night as another sfc high pressure ridge builds in from the west.
However a warm front will bring potential for more showers and
perhaps a few storms late Wednesday and Wednesday night.
Temperatures will remain above to much above normal through the long
range forecast period and average around 10 to 15 degrees above
normal through the period.
&&
.AVIATION...(For the 12Z TAFS through 12Z Saturday morning)
Issued at 746 AM EDT Fri Sep 16 2016
VFR currently prevails across all of our TAF sites. VFR should
continue to prevail into early afternoon (18z) before the showers
and thunderstorms from the frontal system to our west begins to
impact the TAF sites. I feel fairly strongly the TAF sites will
see rain at some point between 18z and 06z but I am not entirely
sure on the actual time. The RAP model supports the idea of
bringing in mvfr cigs in the 00z time frame and given how moist
the air upstream is that makes sense. I am thinking mvfr
conditions will continue into at least mid morning Saturday.
&&
.MARINE...
Issued at 552 AM EDT Fri Sep 16 2016
SINCE WE ARE ALREADY GETTING 3 TO 4 FOOT WAVES AND 15 TO 25 KNOTS
WINDS IN OUR NORTHERN MARINE ZONES I DECIDED IT WAS BETTER TO
START THE HAZARDS NOW AND NOT WAIT TILL LATE THIS MORNING.
&&
.HYDROLOGY...
Issued at 1158 AM EDT Fri Sep 16 2016
Rivers are running near to slightly above normal, but are stable
and remain well within their banks. Moisture will stream northward
out of the gulf late today into early Saturday, lending itself to
developing showers and a few thunderstorms. Some of the rain may
be locally heavy. Aerial averages should result in around one-
quarter of an inch. Widely scattered storms are possible Saturday
with lingering shower possible Sunday. Little additional
precipitation is expected. There are no flooding concerns through
the next several days with little to no signal of any bigger rain
producers.
&&
.GRR Watches/Warnings/Advisories...
MI...Beach Hazards Statement through late tonight for MIZ037-043-050.
LM...Small Craft Advisory until 5 AM EDT Saturday for LMZ847>849.
&&
$$
UPDATE...NJJ
SYNOPSIS...WDM
SHORT TERM...WDM
LONG TERM...JK
AVIATION...WDM
HYDROLOGY...JAM
MARINE...WDM
Area Forecast Discussion
National Weather Service Houston/Galveston TX
932 AM CDT Fri Sep 16 2016
.UPDATE...
Low pressure in the Gulf has resulted in quite a bit of convection
well offshore, but also on the edge of the 60 mile marine zones.
However, RAP analysis shows a wind field that would be more likely
to drag the main shield of convection northeastward towards
southwest Louisiana. As such, nudged PoPs downward a little
farther inland in order to keep the focus on the immediate coast
and up the eastern edge of our area, but the broad picture from
the previous discussion is still a good one. In association with
this low, precipitable water is moving back towards and over 2
inches, so isolated to scattered showers and storms should still
be expected today. Otherwise, nudged temps into line with
observations, but should still be on track to reach to around and
a little above 90 degrees across the area. Heat indices should
also be a touch higher today, reaching to around the century mark.
Luchs
&&
.PREV DISCUSSION... /ISSUED 429 AM CDT Fri Sep 16 2016/
DISCUSSION...
Precip coverage has been gradually increasing offshore in
association with a surface trof situated off the Tx coast. It will
continue its slow wwd progression and set up a convergent zone
along the coast today. This boundary should serve as a focus for
periods of shra/tstms throughout the day...esp as daytime heating
works its magic. There is a potential for some localized heavy
rainfall wherever stronger clusters set up near the sfc
trough/boundary considering that the overall steering flow is
fairly weak and available moisture will be well above normal (pw`s
2-2.3"). Majority of rain/storms should taper off by early evening
w/ the loss of heating - though there could be a couple lingering
cells around for the start of some of the high school football
games.
Coastal trof should wash out on Saturday...but there should still
be ample moisture for some scattered morning precip near the coast
that`ll spread inland during the daylight hours w/ heating.
Mid level ridge then starts building overhead on Sunday and
persists into the mid-late week time period. Look for rain
chances to start tapering off (but not completely shutdown) and
high temps to revert back to near August normals unfortunately. No
real good signals as to when our first decent fall front will
arrive. 47
MARINE...
Generally moderate east winds will prevail today with seas of 2 to 4
feet. However, the approach and passage of a trof/wave axis from the
NW Gulf into our marine areas is expected to produce widespread show-
ers and thunderstorms today and tonight. This unsettled weather will
help to increase winds/seas in and near the stronger storms. As this
system moves inland...winds should eventually veer to the SE through
the weekend. Looking ahead, light onshore winds and low seas will be
on tap for early next week. The slightly above normal tide levels of
late should also follow a gradual downward trend. 41
AVIATION...
Expecting a more active day today as deep Gulf moisture moves inland
in conjunction with a trof/wave axis. With low convective temps...we
will likely see widespread TSRAs starting around mid/late morning at
the coast...then spreading inland through the afternoon. Our current
TEMPO groups look to be on track. Otherwise VFR conditions to return
tonight as the activity dissipates. A repeat of this general pattern
is forecast for tomorrow as well. 41
&&
.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL) 93 76 94 76 94 / 20 20 30 10 20
Houston (IAH) 91 76 91 76 93 / 50 20 50 20 30
Galveston (GLS) 89 80 88 81 90 / 40 50 50 30 30
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
Discussion...99
Area Forecast Discussion
National Weather Service Wichita KS
645 AM CDT FRI SEP 16 2016
.SHORT TERM...(Today through Sunday night)
Issued at 318 AM CDT Fri Sep 16 2016
Hit-or-miss clusters of showers/thunderstorms will affect the
forecast area today, as a cold front approaches from the north and
subtle upper waves approach from the west/southwest. Greatest
coverage early this morning will likely be generally the northeast
quarter of KS, with this activity likely largely diminishing by
mid-morning. Furthermore, weak isentropic ascent ahead of upper
energy approaching from the west should allow for at least widely
scattered showers/storms to eventually develop this morning over
south-central and southeast KS ahead of the cold front. This
activity could become widespread/numerous over far
southern/southeast KS.
Thinking the convectively-reinforced cold front will tend to race
southeast today faster than what NAM/GFS depict, limiting
afternoon/evening thunderstorm redevelopment across the forecast
area. This scenario is supported by the RAP and HRRR, and makes
sense given current southward speed of outflow/cold front. Will
still likely see at least a few storms in vicinity of the front
this afternoon-evening over southern KS, but probably not
widespread/numerous activity. Severe weather-wise, despite poor
mid-level lapse rates, modest instability along with adequate
deep layer shear may promote a few strong to marginally severe
storms throughout the day/evening, along with locally heavy rain.
Five-star weather expected across much of the area Saturday, as
high pressure settles south in wake of the cold front. An
approaching upper disturbance could result in a cluster of
thunderstorms over mainly western portions of KS and OK Saturday
night, with some of this activity possibly affecting locations
generally west of I-135. This activity could linger into Sunday
morning over far southern KS.
.LONG TERM...(Monday through Thursday)
Issued at 318 AM CDT Fri Sep 16 2016
Building upper ridging from the west should allow for dry weather
and above normal temperatures Monday and Tuesday. A weak front
should make its way into KS Mon- Tue, but weak convergence along
with poor upper support and warm mid- level temperatures should
keep the forecast area dry. Expecting thunderstorm chances to re-
enter the forecast by mid to late week, as model consensus
supports a slow moving front approaching from the north, in
concert with southwest CONUS cutoff low finally ejecting to the
east.
&&
.AVIATION...(For the 12Z TAFS through 12Z Saturday morning)
Issued at 645 AM CDT Fri Sep 16 2016
Scattered to numerous convection this morning is expected to
diminish toward midday. However renewed convection is expected
along a cold front this afternoon as it moves across southern
Kansas. Most of the activity should push south into Oklahoma
by late tonight. Winds behind the mesoscale outflow boundary
early this morning will gradually veer from east-northeast to
southeast as the effective surface front becomes re-established
over central Kansas by midday. This front will then move south
across the area this afternoon into the evening. While a period
of IFR can be expected in and near convection this morning, mainly
MVFR or VFR is expected away from convection this afternoon.
KED
&&
.PRELIMINARY POINT TEMPS/POPS...
Wichita-KICT 82 63 82 63 / 60 40 10 20
Hutchinson 80 60 82 61 / 70 30 10 20
Newton 79 61 81 61 / 80 30 10 20
ElDorado 80 63 82 61 / 80 40 10 10
Winfield-KWLD 82 64 83 63 / 50 50 10 20
Russell 78 56 81 59 / 30 10 10 20
Great Bend 78 56 82 59 / 30 10 10 20
Salina 80 59 82 60 / 70 20 10 20
McPherson 80 59 81 60 / 80 20 10 20
Coffeyville 83 66 84 63 / 50 50 20 20
Chanute 81 65 82 62 / 60 50 20 10
Iola 80 64 82 61 / 70 50 20 10
Parsons-KPPF 82 65 83 63 / 50 50 20 10
&&
.ICT Watches/Warnings/Advisories...None.
&&
$$
SHORT TERM...ADK
LONG TERM...ADK
AVIATION...KED
Area Forecast Discussion
National Weather Service Indianapolis IN
1030 AM EDT FRI SEP 16 2016
.UPDATE...
The Aviation Section has been updated below.
&&
.SYNOPSIS...
Issued at 301 AM EDT Fri Sep 16 2016
Chances for rain will increase across the area today into tonight
and continue into Saturday as a frontal system approaches the area.
Drier conditions will return to the area by Monday and should
continue into next week. Temperatures will be above average into
next week.
&&
.NEAR TERM /This afternoon/...
Issued at 955 AM EDT Fri Sep 16 2016
Surface analysis late this morning shows High pressure across New
England. Low pressure was found over Iowa with a cold front
extending south to eastern Kansas. Weak southeast to south flow
was in place across Indiana...and showers and storms were
developing upstream across Missouri and Southern Illinois.
Isentropic lift and warm air advection are expected to get
underway in full swing this afternoon...allowing more humid air
to arrive in central Indiana. HRRR suggests current precip across
Illinois and Missouri will begin to propagate into Central Indiana
by mid afternoon. Given the approaching upper short wave as seen
within the water vapor imagery...the trend toward precip
development appears very reasonable.
Thus have ramped up pops slightly this afternoon. Given the
expected increasing clouds and precip...trended highs
cooler...closer to the 3 hourly MAV values.
&&
.SHORT TERM.../Tonight through Sunday night/
Issued at 301 AM EDT Fri Sep 16 2016
Focus is on chances for rain through the period. Overall the models
are close enough for a continued use of a blend.
HRRR and 00Z ECMWF, and to some extent the NAM, are showing a
relative lull in rainfall coverage during the evening hours. With
better height falls overnight, and an upper jet approaching later
tonight, this seems reasonable. Will thus lower PoPs a bit during
the evening. However the aforementioned features will combine to
produce rain overnight, so went with likely to categorical PoPs all
areas.
Forcing will continue into Saturday morning then the focus should
shift to the southeast some as forcing from the stronger part of the
upper trough moves out of the area. Will allow PoPs to fall back
into chance category north during the afternoon.
Main forcing will move off to the east Saturday night into Sunday,
but the cold front itself will lag behind. Will continue to
gradually lower the PoPs from northwest to southeast through Sunday,
finally going dry Sunday afternoon as the front moves through.
Stuck with a model blend for temperatures.
&&
.LONG TERM /Monday through Thursday/...
Issued at 301 AM EDT Fri Sep 16 2016
It will be dry with warmer than normal temperatures Monday through
Thursday as an upper ridge over the central U.S. builds east across
our region. Will continue a slight chance of a thundershower across
the northwest half of our region Monday night as a weak cold front
moves our way and dissipates.
The rest of the long term period will be dry with high pressure
across the area.
High temperature`s will be in the lower 80s most areas with some
areas in the middle 80s by next Thursday as 850 MB tempertures
become a little warmer. Lows will be mostly in the 60s...except
upper 50s Tuesday night. In most cases stayed close to super blend
temperatures.
&&
.AVIATION /Discussion for 161500z TAF Issuance/...
Issued at 1030 AM EDT Fri Sep 16 2016
Updated current conditions, and converted a prob30 to a tempo group
at KIND for later this afternoon. Previous discussion follows...
Mostly VFR...but briefly MVFR flight conditions possible near
scattered showers and a few thunderstorms from midday on.
For this morning expect only few-sct CU with increasing mid/high
clouds as a trough of low pressure over Iowa moves this way. Expect
scattered showers and a few thunderstorms from midday on. Went
mainly VCTS in TAFS with numerous showers at times later tonight.
Even with scattered showers and a few thunderstorms model soundings
ceilings will be mostly at or above 5 thousand feet. Could see MVFR
visibilities around 5 miles tonight as showers become more numerous.
Light southeast winds this morning will become south or southwest at
5 to 8 knots later today and tonight.
&&
.IND Watches/Warnings/Advisories...
NONE.
&&
$$
SYNOPSIS...50
NEAR TERM...PUMA
SHORT TERM...50
LONG TERM....JH
AVIATION...JH/CP
AREA FORECAST DISCUSSION
National Weather Service Jackson KY
1055 AM EDT Fri Sep 16 2016
.UPDATE...
Issued at 1055 AM EDT FRI SEP 16 2016
Based on 12z NAM and latest runs of the HRRR have updated NDFD
and associated products to reduce rain chances for this afternoon.
Latest thinking is convection will be more isolated to scattered
in nature, with most areas not seeing rain this afternoon. The
best chances for rain still appear to be in the south central and
southwest part of the area, but even there probabilties have been
cut back to 40 percent.
UPDATE Issued at 650 AM EDT FRI SEP 16 2016
RAP has come on board with the consistent HRRR solution for
convection this afternoon. Thus, confidence continues to increase
for a complex of showers and storms to track east across southern
Kentucky this afternoon eventually into southeast Kentucky this
evening. Looks like the primary threat for showers and storms
should stay south of the Mountain Parkway. Latest 06z NAM also
supports shower and storm chances across the southern portion of
the area. Showers and storms look to reach the Somerset/London
areas shortly after 2 pm, and reach Hazard by 4 or 5 pm. Activity
should reach Pikeville area sometime closer to 6 or 7 pm, as the
activity starts to fade off.
&&
.SHORT TERM...(Today through Saturday)
Issued at 315 AM EDT FRI SEP 16 2016
A surface ridge resides across the Appalachian region this
morning, with widespread convection ongoing across the plains
associated with a mid level trough working eastward across the
region. The high pressure ridge will slowly erode through the day
today with some slow height falls expected across eastern Kentucky
by this afternoon. Strong heating, combined with an uptick in
850-700mb RH will lead to some shower/storm development along the
escarpment near the Cumberland Plateau region. HRRR has been
consistent now over 5 runs showing good coverage in showers and
storms this afternoon and evening. Meanwhile, NMM/ARW show very
little, although there is some convection, just not in that
region. The operational models (NAM/GFS/ECMWF) all show some
support for the development across our south central/southern
Kentucky today. With that in mind, have opted to go more
aggressive with the pops across this region today, going with
scattered to numerous coverage on showers and storms. This could
be the first measurable rain for London this month, so certainly
some beneficial rains if they occur as models advertise. If the
coverage indicated on the HRRR is correct, pops may need to go
higher this afternoon. Unlike the past few days, southwest flow
should keep things moving and prevent the potential for 1+ inch
rainfall potential. However, some brief heavy rain is still
anticipated. As the afternoon/evening progresses activity should
move northeast with the mean flow along any outflow from previous
convection. Eventually as instability drops off later this
evening, convection should begin to subside, but may linger on
past 7 or 8 pm before fading away. Best chances will stay across
southern and southeast Kentucky, but a few showers or storms could
impact much of the area. Thus, will even allow for some isolated
pops in the north. Highs today will soar well into the 80s to
around 90, helping to spark the afternoon/evening convection.
Tonight, we should see a lull as the main shortwave trough remains
to our northwest with a vort max spreading northeast into the
great lakes. However, the low level jet over the region, could
spark a shower/storm or two late tonight, mainly across northern
or northeast Kentucky. Saturday will feature another warm day with
highs again well into the 80s. Forcing remains weak or non-
existent through the day, so shower/storm coverage may be more
isolated, but the better rain chances will increase back to the
northwest closer to the mid level trough.
.LONG TERM...(Saturday night through Thursday)
Issued at 415 AM EDT FRI SEP 16 2016
The period is expected to begin with a shortwave trough moving
across the Great Lakes and from the Plains and into the OH and TN
Valleys and the Appalachian region. The axis of this trough
should move east of the area by late Sunday night or early on
Monday. Then, height rises should ensue through midweek with upper
level ridging building into the southeastern states and remaining
in place and dominant through the end of the period. At the sfc, a
cold front should move across the area from Sunday afternoon into
Sunday night. Surface high pressure should build in behind the
front for Monday. A shortwave moving through the Great Lakes
should push a weak cold front into the OH Valley from late Tuesday
into Wednesday. However, this front will wash out or become
diffuse over the area and should produce little more than an
increase in mid level clouds or cu. Another sfc high will build
into the area behind this boundary and remain in place through the
end of the period.
The most active portion of the extended period will be from
Saturday night into Sunday night as the cold front and shortwave
trough approach and then move across the area. This combination
should produce showers and a few thunderstorms across the area
during that period. The highest chances will be on Sunday when
daytime heating should bring enough instability for the greatest
coverage. Otherwise, the Monday through Thursday period should be
dry with above normal temperatures with no more than afternoon
cumulus each day as high pressure dominates.
&&
.AVIATION...(For the 12Z TAFS through 12Z Saturday morning)
ISSUED AT 650 AM EDT FRI SEP 16 2016
Mainly VFR conditions will then be seen through today. However, a
complex of showers and storms may develop and track across
southern Kentucky this afternoon through early evening. This could
bring some brief MVFR visibility restrictions along with a brief
wind gust in and around thunderstorms. Will include a VCTS into
the TAFS for the best window of opportunity for storms today, with
timing information to be included a bit later on as confidence
increases. Any showers and storms will likely impact all TAF sites
except Morehead. Showers and storms will die off by mid to late
evening, with VFR conditions returning tonight. Depending on
rainfall later today and degree of clearing tonight, fog may be a
possibility late tonight, but not confident enough to include at
this point.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...SBH
SHORT TERM...KAS
LONG TERM...JP
AVIATION...KAS
Area Forecast Discussion...Updated
National Weather Service Saint Louis MO
1051 AM CDT FRI SEP 16 2016
.UPDATE...
Issued at 1049 AM CDT Fri Sep 16 2016
Thunderstorms have already produced pockets of 1-3+" of rainfall
this morning across parts of central and east Missouri as well as
southwest Illinois prompting this issuance of flood advisories.
Showers and thunderstorms continue to push along in the
southwesterly mid level flow late this morning. They are being
generated by low level moisture convergence underneath weak ascent
produced by a series of weak vort maxes in the mid level flow.
Expect the showers and thunderstorm to continue to generate and
move northeast across the southeastern two thirds of the CWA this
afternoon and early this evening. Will continue to watch for
potential heavy rainfall and possible flooding based on training
of cells. Temperatures will be held down by clouds and rain.
Britt
&&
.SHORT TERM... (Through Late This Afternoon)
Issued at 334 AM CDT Fri Sep 16 2016
Still some confidence issues with how and where the storms will
develop today. Complex of storms extend from southern Iowa
southwestward to northwestern Missouri and eastern Kansas as of 08z.
In the meantime, scattered showers trying to pop up over
northeast/central down to southwestern Missouri, but little if any
of it is reaching the ground at the moment. HRRR models want to
develop storms over the next several hours, mainly north of I-70,
then eventually spread across majority of forecast area by 12z,
while complex to our north weakens. Will blend a bit of reality and
models for pops today, but did keep likely pops for most locations
at some point today. Won`t see an all day rain, but with plenty of
clouds and some rain, temperatures will struggle to warm up, so have
highs in the upper 70s to mid 80s.
Byrd
.LONG TERM... (Tonight through Thursday)
Issued at 334 AM CDT Fri Sep 16 2016
(Tonight - Sunday)
Expect TSRA to be ongoing at the beginning of the period across the
sern half of the CWA, roughly along and SE of a K3LF to KSTL to KVIH
line. An ULJ back-building into the region as well as an approaching
s/w shud support TSRA into the overnight hrs with help from an
increasing swly LLJ. Uncertain what coverage of TSRA near the actual
cdfnt will be like. Better low level forcing will remain further
south as mentioned above. The ECMWF suggests some ULJ coupling which
may support better coverage near the fnt, but this soln seems to be
an outlier. Still, think sct coverage is reasonable and have
therefore kept chance PoPs going near the fnt.
While the TSRA mentioned above shud push the effective sfc boundary
south of the CWA, the actual cdfnt will still be pushing swd thru
the region. Have kept PoPs in morning vs. afternoon with some
uncertainty in timing, but in general, morning convection shud
continue moving out of the region with any activity along the fnt
dissipating. Expect breaks in clouds to develop allowing some
recovery south of the cdfnt and redevelopment during the afternoon
hours. However, if these breaks do not occur, a dry fropa is
entirely possible. The GFS soln seems to suggest enuf CAA with the
805mb cdfnt that light RA will be possible much of the day. This
soln seems to be an outlier attm, but will keep in mind for future
updates.
With the fnt south of the CWA Sat night, the remainder of the period
remains dry.
As for temps, kept warmer trend going for tonight and Sat as the
region remains south of the fnt. Trended cooler for Sat night thru
Sun as the sfc ridge settles into the region.
(Monday - Thursday)
Temps shud warm quickly on Mon as the sfc ridge builds ewd. However,
this appears to be short lived as another cdfnt shud reach the
region by Mon night into Tues. Can not rule out precip along this
fnt, however, it appears best forcing will remain well north of the
region with the main upper trof over the Great Lakes and low level
forcing well out ahead of the fnt.
Temps shud warm again by mid-week as the upper ridge builds into the
region. Mdl solns differ somewhat with the GFS breaking down the
ridge sooner. Have kept PoPs low thru the end of the period, but
believe the upper ridge will remain in place a bit longer, keeping
the sfc fnt and the associated precip north of the area.
Tilly
&&
.AVIATION... (For the 12z TAFs through 12z Saturday Morning)
Issued at 626 AM CDT Fri Sep 16 2016
Activity on the increase as of 11z, so added tempo mention at all
taf sites through 15z-16z timeframe. Could see a bit of a break
through early afternoon, before more storms fire up. This second
round to diminish during the evening hours. Conditions to remain
VFR outside of storms with south winds through forecast period.
SPECIFICS FOR KSTL:
Activity on the increase as of 11z, so added tempo mention through
16z timeframe. Could see a bit of a break through mid afternoon,
before more storms fire up around 23z. This second round to
diminish during the evening hours. Conditions to remain VFR
outside of storms with south winds through forecast period.
Byrd
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...None.
IL...None.
&&
$$
WFO LSX
Area Forecast Discussion
National Weather Service SAN ANGELO TX
947 AM CDT FRI SEP 16 2016
.UPDATE...
Made a quick update primarily to precipitation totals and POPS
through this afternoon.
&&
.DISCUSSION...
Upper disturbance in the eastward flow aloft has weakened
substantially and will result in hourly amounts less than a tenth
of an inch over primarily the western Concho Valley and Big
Country through the morning hours. Latest HRRR continues to
weaken this disturbance with the 12Z NAM keeping rain chances over
primarily over the Big Country through this afternoon.
&&
.PREV DISCUSSION... /issued 633 AM CDT FRI SEP 16 2016/
AVIATION...
/12Z TAFS/
Showers and storms have largely dissipated across West Central
Texas, with nothing approaching any of the terminals in the short
term. Outflow from the storms have moved south, with MVFR cigs
developing north of the boundary. These MVFR cigs should spread
south and then begin to break up and dissipate by mid morning.
Scattered storms will be possible again this afternoon and
evening, but trying to pin down the timing and location at this
point is questionable. Leave out of the forecast for now and
expect later forecasts to begin to narrow the locations and
timing.
PREV DISCUSSION... /issued 331 AM CDT FRI SEP 16 2016/
SHORT TERM...
(Today and Tonight)
Mesoscale convective complex continues to roll across the Big
Country early this morning, moving east at a decent clip. Large
shield of rain on the back side will be slow to decrease, so highest
rain chances for the first period will actually be with whatever is
left at sunrise this morning. HRRR suggests that additional
convection may develop along the southern flank as the outflow moves
south, perhaps into the Concho Valley and Heartland as well. Have
increased first period PoPs for this possibility, but will continue
to monitor. Will almost certainly need to update PoPs across many
areas based on radar trends as we get closer to sunrise. After the
morning convection ends, wherever the outflow ends up should be an
additional focus for more showers and storms this afternoon.
Models suggest another similar situation for tonight as well, with
more showers and storms developing to the west and tracking east
across mainly the northern half of the area. Given how poorly the
models have handled this mornings convection, hate to jump on the
possibilities for tonight. Left the PoPs in the chance range for
tonight, and see if later data and pinpoint locations a little
better.
LONG TERM...
(Saturday through Thursday)
An upper level low will be located offshore the northern coast of
Baja California on Saturday, while an upper level ridge across
South Texas begins to build. This will keep West Central Texas in
a general west flow aloft. There are a hints of a weak disturbance
moving across the region Saturday, resulting in scattered showers
and thunderstorms mainly across the Big Country. In addition a
weak cold front is forecast to be across the South Plain/Red
River, but at this time is expected to remain north of our area.
Given the lack of upper level forcing and uncertainty on the
timing and strength of the possible disturbance, PoPs were kept in
the 20-30 percent range across the area. A few storms may linger
into the evening hours, with most convection dissipating by late
evening.
The aforementioned upper level ridge will begin to build over much
of Texas, including West Central Texas, Sunday through the middle of
next week. Isolated showers and thunderstorms cannot be ruled on on
Sunday, and slight chance PoPs were retained. Otherwise, expect a
mainly dry forecast for the upcoming work week. Highs on Sunday and
Monday will be well above seasonal normals, mainly in the mid 90s,
as the upper level ridge centers itself over the region. The center
of the ridge is eventually forecast to move toward the Mid/South
Atlantic Coast, which should result in slightly cooler temperatures
for West Central Texas.
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 90 70 90 71 / 40 50 30 20
San Angelo 93 69 92 71 / 20 30 30 10
Junction 94 68 93 70 / 10 20 30 10
Brownwood 91 71 91 71 / 20 40 30 10
Sweetwater 91 67 87 70 / 50 50 30 20
Ozona 90 71 92 70 / 20 20 20 10
&&
.SJT Watches/Warnings/Advisories...
None.
&&
$$
99/99
Area Forecast Discussion
National Weather Service Tampa Bay Ruskin FL
1113 AM EDT FRI SEP 16 2016
.SYNOPSIS...
15Z water vapor and H4 RAP analysis shows a broad region of
weak mid/upper level ridging over the eastern Gulf of Mexico and
Florida Peninsula. The weakness of the ridge is keeping the
overall suppression low, and the column overhead on the 12Z KTBW
sounding was quite moist. Dewpoint depressions through much of
the trop were small...and the PW value was over 2". The profile
did not suggest many negative factors toward deep convection, but
also did not indicate much potential for strong updraft leading to
intense convection. The other factor to note was the lack of winds
through the convective steering layers. Wind are almost
light/variable between 800-250mb. Convection that does develop
during the afternoon/early evening is not going to have much push
behind it, and therefore, slow movement and localized heavy
rainfall potential. However...what might limit the overall rain
total potential...is that very slow movement means rapid inflow
cuttoff and updraft dissipation once precip begins to fall.
At the surface...the peninsula is within a fairly weak pressure
gradient between ridging nosing down into the NE Gulf from
GA/Carolinas...and Tropical Storm Julia off the GA/Carolina
coasts. The light flow will allow for sea-breeze circulations to
develop on both coasts and move inland. Good guidance agreement in
a scattering of storms developing through the afternoon hours. As
mentioned above, any storms are likely to be slow moving...and
dissipate rather quickly to the kinematics and thermodynamics
aloft. Temperatures climbing to within a degree or 2 either side
of 90 by mid-afternoon.
&&
.SHORT TERM...
Scattered evening storms dissipate within a few hours of sunset /
and or move offshore into the eastern Gulf. The remainder of the
overnight looks to have a seasonable yet warm forecast with low
temps in the low/mid 70 most spots...although mid/upper 70s will
be common at the beaches. Similar to past mornings...should see a
bit of patchy fog toward dawn...especially north of the I-4
corridor...however...no widespread or dense fog is anticipated.
Low level winds over the northern half of the peninsula do shift
out of the NE after midnight...and this direction with available
moisture and ridging aloft can be favorable at times for areas of
lower stratus to expand to the south and southwest toward the I-4
corridor of Polk/Hillsborough. Not much of an impact to the
sensible weather forecast, but potential impacts for the aviation
community and TAF forecasts.
The large scale synoptic pattern does not change much between
today and Saturday. One factor that will be monitored closely with
the 12Z Guidance package is the potential for some dry air arrival
aloft over the northern peninsula during the afternoon hours.
GFS/NAM/ECMWF all show a swath of drier column air (above approx
800mb) that rotates down into our northern areas around the
circulation of Tropical Storm Julia. By late in the day
Saturday...minimum thetaE values in the mid-levels range from
convectively very favorable values in the mid 330sK along and
south of I-4...to much less favorable mid 320sK up toward
Levy/northern Sumter counties. This is a fairly significant
moisture gradient, and one would think it will end up being
represented in the overall diurnal showers coverage. Now a thetaE
of 325K is not an extreme value by any means...but when compared
to readings further south, certainly suggest a more hostile
environment though updraft entrainment.
Given this drier swath of air...will have to keep rain chances
lower to the north of the I-4 corridor...especially the closer to
I-10 one travels, however, the environment does not support
completely removing all rain chances. Higher afternoon chances
for a passing storms will exit along and south of the I-4
corridor...in agreement with most explicit and parameterized
guidance ensembles. High temperatures for Saturday once again end
up a couple degrees above normal...with mainly lower 90s away from
the immediate coast.
&&
.AVIATION...
VFR conditions prevail across west-central and southwest Florida
late this morning as we a sct-bkn cumulus field begins to develop.
Eventually, a scattering of showers and storms will develop...
mainly after 17Z. While it is too early to determine which
terminal might see a storm, any storms that do develop are likely
to be very slow moving...meaning a longer heavy rainfall threat
under a specific cell. Storms fade by 03Z...followed by prevailing
VFR conditions for a least several hours. Late at night, pattern
favors and will watch for areas of lower stratus potential
arriving from the NE toward KLAL/KTPA after 08Z.
&&
.MARINE...
Weak high pressure nudges down into the eastern Gulf from the
Southeastern States. This ridge is holding what is currently
Tropical Storm Julia off the Carolina/Georgia coast. This storms
is not expected to move much through the duration of the upcoming
weekend...and should generally not impact our local waters. With
weak high pressure remaining in control...expect light winds and
low seas through the next several days...with onshore breezes
developing each afternoon.
&&
.FIRE WEATHER...
No significant fire weather concerns are anticipated through the
upcoming weekend. Generally light flow will remain in place across
the Florida peninsula...with abundant low level moisture to keep
relative humidity values above critical levels. We are likely to
see a daily scattering of afternoon storms...with temperatures and
rain potential near normal for this time of year.
Fog Potential...No significant areas of widespread or dense fog
are anticipated through the upcoming weekend.
&&
.Preliminary Point Temps/PoPs...
TPA 90 76 90 77 / 40 30 50 20
FMY 90 76 91 76 / 40 30 50 20
GIF 90 75 90 75 / 60 30 50 20
SRQ 89 76 88 76 / 30 20 50 20
BKV 90 74 90 73 / 40 30 50 20
SPG 89 78 89 78 / 30 20 50 20
&&
.TBW Watches/Warnings/Advisories...
FL...None.
Gulf waters...None.
&&
$$
SYNOPSIS/SHORT TERM/AVIATION/MARINE/FIRE WX...Mroczka
AREA FORECAST DISCUSSION
National Weather Service Topeka KS
633 AM CDT FRI SEP 16 2016
.SHORT TERM...(Today and tonight)
Issued at 256 AM CDT Fri Sep 16 2016
Early this morning an outflow boundary, generated from more intense
storms last evening across west central KS and south central NE, was
moving southeast across the CWA and at 230 AM extended from near
Holton, southwest to Alma, then southwest to Hope. Isentropic lift
north of this boundary was causing numerous showers and scattered
elevated thunderstorms to develop across most areas northwest of the
outflow boundary. WV satellite showed an intense upper trough across
central ND and western SD with a trough axis extending southward
into western NE and northeast CO.
The higher resolution models such as the WRF and exp-HRRR forecast
the broad area of showers and thunderstorms across much of the CWA
to weaken by 12Z and rapidly shift southeast across the CWA through
the mid morning hours. The WRF and HRRR show the front moving
through most of the CWA dry early this afternoon with a line of
thunderstorms developing along the front after 21Z just to the
southeast of the CWA.
The NAM, GFS and ECMWF show the widespread showers and thunderstorms
across the northern and western half of the CWA to continue to
expand southeast and continue into the afternoon and evening hours
ahead of the the surface front and upper trough translating east
across the northern and central plains.
At this time I kept likely POPs this morning across much of the CWA,
with POPs decreasing across north central KS during the mid and late
morning hours. I kept chance POPs going across the CWA through the
afternoon hours and into the night across east central KS. If the
higher resolution models are more accurate, then POPs may be much
lower across the CWA during the afternoon hours with dry conditions
into the evening.
There is a risk for isolated flooding if some areas, if training of
showers and thunderstorms develop through the morning into the
afternoon hours. Though most guidance forecast QPF to remain below a
half inch. The areas to watch will be far northeast KS where heavy
rainfall occurred Tuesday night into Wednesday morning.
Highs Today will reach the mid to upper 70s but if the rain
continues through the day across northeast and east central KS, then
high temperatures may be cooler. Overnight lows will be slightly
cooler behind the front with mid to upper 50s across north central
KS and lower 60s across east central KS.
.LONG TERM...(Saturday through Thursday)
Issued at 256 AM CDT Fri Sep 16 2016
By Saturday morning, the upper level trough will be located over the
northern Great Lakes with the associated cold front extending down
into southern Oklahoma. Surface high pressure will move into
northeast Kansas later in the morning, providing clearing skies and
light winds through the day Saturday. Overall, a dry weekend and
early work week look to be in store, with the next chances for
precipitation beginning Wednesday and continuing until the end of
the period. Models continue to not be in very good agreement toward
the end of the period about a upper level trough tracking over the
northern CONUS, so confidence in PoPs right now is below average.
Temperatures look to be near climatology on Saturday and Sunday with
a warmup beginning by Monday where highs are forecast in the upper
80s and staying near the mid 80s through the week.
&&
.AVIATION...(For the 12Z TAFS through 12Z Saturday morning)
Issued at 615 AM CDT Fri Sep 16 2016
periods of showers and a few thunderstorms will continue through
the morning hours across the terminals. The showers should move
southeast of the terminals during the afternoon hours. There may
be brief MVFR conditions during the heavier showers or
thunderstorms at the terminals.
&&
.TOP Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...Gargan
LONG TERM...Heller
AVIATION...Gargan
Area Forecast Discussion
National Weather Service Tulsa OK
816 AM CDT FRI SEP 16 2016
.DISCUSSION...
Outflow from 2 separate decaying storm complexes /one to the
north, one to the west/ will converge on Eastern OK and Northwest
AR later this morning. The synoptic cold front lies across KS and
will slowly move this direction given its nearly parallel
orientation to the flow aloft. Storms continue to develop along
the advancing outflow boundaries, and should continue to do so
with elevated instability in place over the region. Severe risk is
low this morning given strong SBCIN and modest shear, but could
increase this afternoon where the boundary layer destabilizes.
More storms will develop along the true cold front off to the
north and west this afternoon, and these storms will affect the
region tonight.
Lacy
&&
.PREV DISCUSSION... /Issued 545 AM CDT FRI SEP 16 2016/
AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM/KROG.
Timing of thunderstorms at area TAF sites was based on the latest
runs of the HRRR which affects the eastern Oklahoma TAF sites
this morning and the Arkansas TAF sites late morning into the
afternoon. Mainly VFR conditions are expected outside of the
thunderstorms.
PREV DISCUSSION... /Issued 409 AM CDT FRI SEP 16 2016/
DISCUSSION...
The latest runs of the experimental HRRR suggest that convective
complexes across Kansas and northwest Texas will merge later this
morning and affect parts of mainly northeast Oklahoma and
northwest Arkansas later this morning into this afternoon.
Additional convection may develop this evening and overnight as a
weak frontal boundary sags south into the area. One last chance of
showers and thunderstorms will occur late Saturday night and
Sunday as a weak upper level disturbance moves across the area.
Clouds and precipitation will tend to hold daytime temperatures
down a bit through this weekend, but most places will remain a few
degrees above the seasonal normals.
An unseasonably strong ridge of high pressure will build over the
area next week and will result in much above normal temperatures,
with little chance of any rainfall. Current forecast temperatures
may be conservative for much of next week, with 90s looking
likely for much of eastern Oklahoma and west central Arkansas each
afternoon. The upper ridge will break down late next week into the
following weekend, which may finally allow a more significant cold
front to drop south across the area
Stayed close to guidance temperatures the next couple days.
&&
.PRELIMINARY POINT TEMPS/POPS...
TUL 86 68 87 65 / 60 50 20 20
FSM 90 70 90 69 / 60 40 30 10
MLC 89 69 89 67 / 50 50 30 20
BVO 85 65 86 61 / 70 50 20 20
FYV 84 65 85 62 / 60 50 30 10
BYV 84 65 84 63 / 60 50 40 10
MKO 87 68 87 66 / 60 50 30 20
MIO 84 66 85 62 / 70 60 20 10
F10 88 68 88 67 / 50 50 30 20
HHW 91 71 91 70 / 50 30 30 10
&&
.TSA Watches/Warnings/Advisories...
OK...None.
AR...None.
&&
$$
LONG TERM....30
Area Forecast Discussion
National Weather Service Dodge City KS
312 PM CDT FRI SEP 16 2016
.SHORT TERM...(This evening through Saturday)
Issued at 211 PM CDT Fri Sep 16 2016
A stubborn corridor of low stratus has persisted along the surface
cold front boundary this morning into the mid afternoon. These
clouds should improve along the central corridor, as the frontal
boundary eventually shifts east later this afternoon and tonight
while redeveloping farther east when the BL cools. The HRRR is
still holding on to chances for convection along what appears to
be a SE advancing radar fineline late this afternoon. The window
for isolated storms is small however with the loss of differential
heating.
By Saturday, weak high pressure settle in behind the surface
boundary which should be over western OK. That will mean generally
light and variable winds in central KS with more of and easterly
component for much of our area, and slightly warmer temperatures
around 80 with more abundant insolation.
.LONG TERM...(Saturday night through Friday)
Issued at 211 PM CDT Fri Sep 16 2016
Models indicate a shortwave moving out of the Rockies into the
Plains by late Saturday. The recent WRF runs are perhaps the most
robust in terms of driving initial surface based colorado
convection into western and even central Kansas Saturday night. It
is likely the mid level instability will be more of a factor in
sustaining storms this far east, as the surface dew points in the
far west have decreased significantly. The rest of the extended
period will generally be dry as a zonal flow and high pressure pattern
takes shape for the central Plains. However the model blends
suggest a return of thunderstorm chances late in the week.
&&
.AVIATION...(For the 18Z TAFS through 18Z Saturday afternoon)
Issued at 1236 PM CDT Fri Sep 16 2016
IFR/LIFR stratus has held longer this morning than most of the
models have anticipated, leading to a few TAF amendments. Going
foreword, visible satellite imagery is showing significant breaks
and holes in the stratus layer, as area METARs show steady
improvement to the ceiling heights.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 55 81 59 88 / 10 0 30 10
GCK 53 81 57 88 / 10 10 30 0
EHA 55 81 58 88 / 20 30 30 0
LBL 56 81 59 89 / 20 20 40 10
HYS 55 81 58 87 / 10 0 20 0
P28 61 83 61 87 / 30 0 20 10
&&
.DDC Watches/Warnings/Advisories...NONE.
&&
$$
SHORT TERM...Russell
LONG TERM...Russell
AVIATION...Russell
Area Forecast Discussion
National Weather Service Quad Cities IA IL
307 PM CDT FRI SEP 16 2016
.SYNOPSIS...
Issued at 307 PM CDT Fri Sep 16 2016
More breaks in the clouds helped early afternoon temperatures warm
up into the lower 80s over much of the area. Areas behind a cold
front, from Freeport to Iowa City and points to the northwest,
were generally in the 70s. A broken line of showers and isolated
thunderstorms continued to develop along the cold front, near and
just west of the Mississippi River.
&&
.SHORT TERM...(This Evening through Saturday)
ISSUED AT 307 PM CDT Fri Sep 16 2016
The main forecast issued in the short term period are timing and
coverage of showers/thunderstorms through tonight.
Latest runs of the HRRR continue to model the current convective
development near the Mississippi River quite well and gradually
translate the broken line of showers and thunderstorms to the
east of the river through the early evening. Some isolated small
hail and gusty winds not out of the question with the strongest
storms, but the threat for severe weather remains low, mainly due
to relatively weak instability and deep layer shear. A few
showers/isolated storms will be possible again later tonight, but
have followed the 12z model trends in trimming back pops. Again,
areas along and east of the Mississippi will be most favored for
rain. Lingering cloud cover will influence lows tonight, with the
northwest Wapsi Valley areas favored for the most clearing. These
areas will likely dip into the mid 50s.
On Saturday, drier air will filter into the region behind the cool
front. Expect near normal highs from the low to mid 70s north, to
near 80 degrees south.
.LONG TERM...(Saturday Night through Friday)
ISSUED AT 307 PM CDT Fri Sep 16 2016
A shift toward a more zonal upper level flow, with the main jet
stream setting up along the U.S./Canadian border, will return
summer-like weather for much of next week. This will lead to
above to well above normal temperatures and seasonably high
humidity levels. Weak frontal systems will bring potential for
showers and thunderstorms Monday into Monday night, with a more
likely setup for widespread rain late in the week.
Sunday into Sunday night, the high shifts eastward with a breezy
return flow warming temperatures into the upper 70s to lower 80s.
Subsidence aloft and dry air should lead to mostly clear skies, but
winds should stay up enough overnight to result in warmer night with
mins from the upper 50s to lower 60s.
Monday, a shortwave passing well to the north is shown drawing
deeper moisture northward into the area, likely sufficient to
support at least scattered showers and thunderstorms with the
associated cold front in the afternoon and evening. Current timing
would allow enhanced prefrontal warming to boost temperatures into
the lower to mid 80s. High pressure that follows should allow mins
to return to the 50s over much of the area.
Tuesday will be between systems with slightly cooler temperatures.
Convection is shown by the ECMWF and especially the GFS setting
along a moisture convergence axis across the far north and NW late
Tue night into Wed. The developing southerly winds will bring
humidity back into the area with highs from the upper 70s north to
possibly mid 80s in the south through Friday. Rain chances increase
Thu and Fri as a the upper flow becomes more active from the
southwest ahead of a developing trough over the Pacific NW.
&&
.AVIATION...(For the 18Z TAFS through 18Z Saturday Afternoon)
ISSUED AT 127 PM CDT Fri Sep 16 2016
Expect mainly MVFR ceilings lingering this afternoon. A line of
scattered thunderstorms is developing and expected to impact KMLI
and possibly KBRL through mid afternoon. Otherwise, expect
clearing this evening, then increasing low VFR clouds and possibly
some MVFR fog overnight.
&&
.HYDROLOGY...
Issued at 127 PM CDT Fri Sep 16 2016
Adjustments were made this morning based on new forecasts and
increasing confidence of flooding enhanced by the heavy rainfall
that occurred last night over the upper reaches of the Cedar, Iowa
and Wapsipinicon river basins.
Along the Wapsipinicon River at DeWitt: New forecasts over the past
couple runs have indicated a change from expected minor to now
moderate flooding. With flood stage now looking increasingly more
likely to be surpassed within 48 hours, have upgraded the watch to a
warning for moderate flooding.
Along the Iowa River: At Marengo, will be continuing the flood watch
and monitor trends closely this afternoon as sharp rises continue
there and at points upstream. If current trends continue, the watch
may be upgraded to a warning for minor flooding this afternoon or
this evening. Further downstream, adjusted forecasts taking into
account release forecasts from Coralville no longer indicate
flooding at Wapello or other sites downstream from Iowa City.
including Wapello.
Minor flooding that began last night along the Cedar River near
Conesville continues this afternoon and the flood warning remains in
effect.
&&
.DVN Watches/Warnings/Advisories...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
SYNOPSIS...RP Kinney
SHORT TERM...RP Kinney
LONG TERM...Sheets
AVIATION...RP Kinney
HYDROLOGY...Sheets
Area Forecast Discussion
National Weather Service Grand Forks ND
257 PM CDT FRI SEP 16 2016
.SHORT TERM...(This evening through Saturday)
Issued at 257 PM CDT Fri Sep 16 2016
The main forecast challenge will be the potential for any strong
to severe thunderstorms across southeast ND into west central MN
into the early evening. On the positive side, the SPC meso page
shows sfc based lifted indices just slightly below zero across
most of the FA. Some holes in the clouds have allowed temps to
rise into the upper 60s across southeast ND and west central MN,
with dew points in the upper 50s. This has resulted in sfc based
CAPE values of 500-1000 J/kg. Water vapor imagery shows another
wave moving toward southeast ND, rotating around the parent upper
low over east central ND. It appears this area is being picked up
somewhat by the non supercell tornado parameter on the SPC meso
page, depicting a weak circle over southeast ND.
On the negative side, 0-6km shear is weak, with the higher values
moving into eastern MN. 0-3km VGP values around 0.1 are more over
southwest MN, water vapor shows a more disjointed low, and the sfc
pattern is weak. SPC maintains a marginal risk for severe weather
over west central MN through early evening. The Mayville radar has
shown an increase in popcorn showers and weak thunderstorms over
the past hour. The HRRR continues to show this activity spreading
into west central MN through the evening. So there is still a
window from late afternoon into early evening where a few strong
to severe storms are possible. Otherwise the pcpn will slowly
decrease from west to east tonight into early Saturday.
.LONG TERM...(Saturday night through Friday)
Issued at 257 PM CDT Fri Sep 16 2016
A pleasant Saturday should be followed by similar weather on Sunday.
Some cloud cover is likely to stroll from west to east along the
International border by afternoon, but surface low pressure should
remain far to the north over central Manitoba along with
accompanying forcing vis a vis 500 mb short wave. So slight pops are
featured only along far northern parts of the forecast area.
Elsewhere a southwest breeze will boost the mercury well up into the
70s. On Monday this system will head farther to the north and east
leaving the region with partly sunny skies and near seasonable
temperatures.
High pressure and zonal flow translates to another sunny and
seasonal day Tuesday but on Wednesday there is a risk of some
isentropically induced -RA/-SH north of a boundary lurking just
south of the forecast area. By Thursday a closed "bowling ball"
feature has a good shot of moving out of the northern high plains,
affecting our region with perhaps an extended period of pcpn later
Thursday on into Friday.
&&
.AVIATION...(For the 18Z TAFS through 18Z Saturday afternoon)
Issued at 107 PM CDT Fri Sep 16 2016
Ceilings have been bouncing all over the place today, so really
hard to nail things down. Have generally gone with MVFR
conditions, but there may be lots of local variation. Showers are
again at a lull, but think the activity will pick up again thru
the afternoon. As the system finally shifts off to the east later
tonight into early Saturday, ceilings should improve.
&&
.FGF Watches/Warnings/Advisories...
ND...None.
MN...None.
&&
$$
SHORT TERM...Godon
LONG TERM...WJB
AVIATION...Godon
Forecast discussion for routine afternoon forecast issuance
.SHORT TERM...Tonight and Saturday
Issued at 219 PM CDT Fri Sep 16 2016
Main band of showers and thunderstorms moving across eastern
Wisconsin as of mid afternoon. Once this afternoon exits the
area by late afternoon/early evening, most of the region
will be dry tonight. The only exception will be across the
north where lingering chances of showers will continue through
the night. Cloudy conditions will continue tonight with patchy
fog developing late this evening and overnight.
Clouds will be on the decrease Saturday morning across eastern
Wisconsin before clouds redevelop during the afternoon hours.
Mostly cloudy skies along with a chance of showers will prevail
across the north. High temperatures will range from the upper
60s north to the upper 70s across east-central Wisconsin.
.LONG TERM...Saturday Night Through Friday
Issued at 219 PM CDT Fri Sep 16 2016
An active mid to long term is set for the western Great Lakes for
a good portion of next week as a series of low pressure systems
track through the region.
The extended forecast start out relatively quiet during the latter
part of the weekend as a weak ridge of high pressure tracks
through the western Great Lakes. This period of quiet will be
relatively short lived as a cold front tracks through the western
Great Lakes Monday and Monday evening. This cold front will be
relatively weak, with not much in the way moisture with the best
forcing stays to the north. Therefore pops during this period will
continue to be low.
By the middle to late part of next week better moisture advects
north from the Gulf of Mexico as several additional low pressure
systems track through the western Great Lakes. This setup will
bring a better chance of rain to the area from Wednesday through
next Friday. Model solutions have come more in line with each
other during this very unsettled period, therefore confidence is a
bit higher than normal for this part of the forecast, hence the
higher pops in the forecast.
&&
.AVIATION...for 18Z TAF Issuance
Issued at 1205 PM CDT Fri Sep 16 2016
A band of showers and scattered thunderstorms was moving across
central into northeast Wisconsin early this afternoon. VFR
ceilings were occurring south of this band of rain. To the
north and west, IFR ceilings were noted across central into
north-central Wisconsin. Per the latest HRRR model, the band of
showers and storms should shift east into the remainder of
northeast and east-central Wisconsin. The activity should wane
or end across central and north-central Wisconsin this afternoon.
Ceilings across northeast and east-central Wisconsin will tank
this evening due to abundant low level moisture and light winds.
Sky cover a little tricker across central and north-central
Wisconsin. There may be a break in the IFR ceilings as latest
observations indicated VFR ceilings west of the area. Any
improvement in the clouds will be brief as low clouds should fill
back in quickly after sunset.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
Beach Hazards Statement until 1 AM CDT Saturday FOR WIZ022-040-
050.
&&
$$
SHORT TERM.....Eckberg
LONG TERM......Kurimski
AVIATION.......Eckberg
Area Forecast Discussion
National Weather Service Wichita KS
314 PM CDT FRI SEP 16 2016
.SYNOPSIS...
Issued at 305 PM CDT Fri Sep 16 2016
A trough over the Northern Plains with a negative tilt
will continue to trot eastward today. The cold front associated with
this wave is currently positioned from northeast to south central
Kansas and into the Panhandles.
&&
.SHORT TERM...(This evening through Monday night)
Issued at 305 PM CDT Fri Sep 16 2016
Forecast challenge - Precipitation for this evening and tonight as
the cold front pushes southeast.
Convection that began off of an outflow boundary from the overnight
activity ahead of the front has persisted in south central and
southeast Kansas throughout the day. Given the worked over
environment following this convection, it is not likely that there
will be widespread redevelopment in most of south central as the
front moves southeast. However, there was brief scattered
development along the front in the early afternoon. In the clearing
across southwest Kansas, scattered clouds have started to bubble
along front which may move into south central Kansas. Right now
reservation exists on how the evening will evolve. The HRRR and
other models show persistent activity in southeast Kansas which will
diminish after 0z with a complete exit by ~3z. Given the radar, it
could be even sooner.
Current thinking is the activity that would develop would be
mainly heavy rain producers for the area which could lead to
flooding. Ongoing convection falling onto the moist surface from
the storms of last evening has caused flooding problems in
southeast Kansas. Obviously any additional rainfall would
exacerbate the problem. Chances of precip were held through the
evening and overnight for now, yet anticipation in changes of the
current forecast are likely.
A ridge moves in for Saturday which will bring a pleasant day across
the Plains. Outdoor activities are encouraged to flourish. There is
a weak wave that will push through on Saturday night into early
Sunday, but this is a very subtle feature especially closer to the
surface. It is not out of the realm of possibility for scattered
shower and thunderstorm activity after midnight along the KS/OK
border. Slight chances were removed for the evening as the slight
possibility appears to be later.
.LONG TERM...(Tuesday through Friday)
Issued at 305 PM CDT Fri Sep 16 2016
A ridge builds back in for the first of the week and will encompass
a majority of the CONUS. The next trough will come from the Pacific
Northwest on Wednesday. There is another subtle wave along the lee
of the Rockies ahead of the main trough which will meander east for
the latter part of the week. Models have definitely come into better
agreement than yesterday with only slight timing differences; the
Northern Plains anticipated position will cap off the work week.
Current indications suggest this trough will be deepen more than the
system from this week. More changes are on the way for the evolution
of this system through model land.
&&
.AVIATION...(For the 18Z TAFS through 18Z Saturday afternoon)
Issued at 128 PM CDT Fri Sep 16 2016
Very challenging forecast. Weakening outflow boundary has pushed
into Oklahoma, with extensive rain showers/thunderstorms north of
the boundary. This was enhanced this morning by transient
shortwave evident in water vapor. Initially was thinking
shortwave and morning convection would suppress much/most of
afternoon convection. However in the past hour or so, convection
has attempted to develop near front in Central KS. MVFR-IFR
ceilings have been in/out at several sites and has been impossible
to track from satellite given higher overcast layer. Thinking
precipitation will need to be mentioned into the evening per
model. The big question is how quickly low level dry air will
overspread the area. There are some indications that given lack of
strong push on front, near saturated boundary layer may linger in
south Central KS for much of the night. Will trend forecast in
that direction, but not ready to go IFR yet. -Howerton
&&
.PRELIMINARY POINT TEMPS/POPS...
Wichita-KICT 62 82 63 85 / 30 10 10 10
Hutchinson 60 82 61 85 / 20 10 10 10
Newton 61 81 61 84 / 30 10 10 10
ElDorado 63 82 61 84 / 40 10 10 10
Winfield-KWLD 64 83 63 86 / 40 20 20 10
Russell 54 81 59 87 / 10 10 10 10
Great Bend 54 82 59 87 / 10 10 10 10
Salina 59 82 60 86 / 20 10 10 10
McPherson 59 81 60 85 / 20 10 10 10
Coffeyville 65 84 62 86 / 50 20 20 20
Chanute 65 82 61 84 / 50 20 10 10
Iola 64 82 61 83 / 50 20 10 10
Parsons-KPPF 65 83 62 85 / 50 20 10 20
&&
.ICT Watches/Warnings/Advisories...
None.
&&
$$
SYNOPSIS...VJP
SHORT TERM...VJP
LONG TERM...VJP
AVIATION...PJH
Area Forecast Discussion
National Weather Service Lincoln IL
259 PM CDT FRI SEP 16 2016
.SHORT TERM...(This evening through Saturday)
ISSUED AT 259 PM CDT Fri Sep 16 2016
Several disturbances ahead of a cold frontal boundary currently
extending from Minnesota southward through Oklahoma will be the main
features over the upcoming day. Presently, a small break between
thunderstorm clusters over central and southeast IL looks on track
for portions of the afternoon...then a disturbance currently over
Missouri looks to spread additional thunderstorms into the area for
the evening. latest HRRR model appears best on track with these
features and have used this solution as a guide for tonight bringing
back likely thunderstorms from around I-72 southward through the I-
70 corridor by 6 p.m. and 30-50 percent chance to the north.
Scattered thunderstorms should persist through the night...then
shifting slowly eastward through the day Saturday while tapering off
from west to east. Lows tonight in the mid to upper 60s in the moist
air mass ahead of the approaching cold front...then highs around 80
again Saturday as temperature contrast across the frontal boundary
is minimal compared with the change in dewpoint...which should begin
to drop into the upper 50s behind the front.
&&
.LONG TERM...(Saturday night through Friday)
ISSUED AT 259 PM CDT Fri Sep 16 2016
The cold front should finally move through the rest of the state
Saturday evening. With both the GFS and NAM hinting at additional
precip developing along the front, keeping a chance of showers and
storms in the forecast for the east and southeast parts of the CWA
is a good forecast. Dry weather is then expected for the rest of the
weekend and into the beginning of next week. However, with a
somewhat zonal flow, another weather system will approach the area
but will have limited moisture. The strongest part of this next
system is expected to move into the Great Lakes region, but a
trailing cold front will drop through the area Monday night. Will
maintain a chance of showers and storms in the northern part of the
CWA, mainly north of I-72. Another weather system is possible in the
zonal flow for the last half of the week, but again, moisture will
be limited. Also, models differ on placement and timing of the
precip so will just keep the model blend of 20 pct chance of precip
for Wed night through Friday.
Zonal flow across the northern half of the US, from the weekend and
through next week, will be conducive for an upper level high
pressure to build into the southern US. This will bring warmer temps
back into the area through most of the period. Expect highs during
the afternoon above normal, in the lower to middle 80s; with above
normal lows as well.
&&
.AVIATION...(For the 18Z TAFS through 18Z Saturday afternoon)
Issued at 1256 PM CDT Fri Sep 16 2016
Scattered showers and thunderstorms will impact the central
Illinois terminals during the 18Z TAF valid time. Outside of the
precipitation, VFR conditions should prevail. A break in
thunderstorms is expected for at least KSPI-KBMI-KPIA from
shortly after 18Z until around 21Z however an additional
disturbance is expected to enhance thunderstorm activity across
the area after 21Z and have incorporated VCTS in all TAFs at that
point with a TEMPO group for MVFR conditions in TSRA from around
00-04Z which will be the most likely time for thunderstorm impacts
at central IL terminals. Winds SSW around 10 kts becoming WSW late
in the period.
&&
.ILX Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...Onton
LONG TERM...Auten
AVIATION...Onton
AREA FORECAST DISCUSSION
National Weather Service Jackson KY
311 PM EDT Fri Sep 16 2016
.SHORT TERM...(This evening through Saturday night)
Issued at 311 PM EDT FRI SEP 16 2016
For the rest of this afternoon isolated showers and thunderstorms
will occur, mainly across the southern and eastern part of the
forecast area. Most areas will not see any rain this afternoon
though. Until forcing increases with the approach of the upper
level trough and surface cold front later in the weekend,
convection should remain scattered at best.
The models have not been handling the near term weather very
well. This includes the HRRR, which last night was more aggressive
with convection for today. As the day progressed the HRRR pulled
back on the afternoon convection but has recently been showing
more convection overnight, and even the GFS MOS is showing likely
probabilties of rain in spots tonight. Not surprisingly the CR
superblend came in with rather high probabilities tonight, but
mainly in the northeast part of the forecast area, with low
probability in the southwest. This at least makes sense with the
best chance for showers in the southwest this evening and the
northeast later tonight. With the model uncertainty in rain
chances will adjust the superblend precipitation probability with
the idea any convection will be spotty until Sunday and also
considering neighboring WFO forecasts.
.LONG TERM...(Sunday through Friday)
Issued at 311 PM EDT FRI SEP 16 2016
The period will begin with a shortwave trough moving across the
Great Lakes and Ohio Valley regions before pushing east of our
region by Monday morning. Nice weather, incident with height rises,
will ensue through midweek with upper level ridging building into
southeastern CONUS. This ridging is progged to remain in place
through the end of the period.
At the surface, a cold front will push through East Kentucky from
Sunday afternoon into Sunday night. High pressure will build in
behind the front on Monday and remain in place through Tuesday
morning. A quick-moving shortwave trough crossing through the Great
Lakes will push a weak cold front into the Ohio valley Tuesday
evening into Wednesday. This front is expected to wash out before
reaching our area and therefore shouldn`t provide the area with any
measurable precipitation. Another surface high builds into the
region Wednesday and should remain in place through the work week.
The only real chance for precipitation comes at the beginning of the
period with the trough and cold frontal passage. This combination
should produce showers and thunderstorms across the area Sunday
through Sunday night, with the best chance on Sunday afternoon when
there is plenty of instability for potential storms to tap into.
Beyond this frontal passage, the weather should remain warm and dry
with above normal temperatures, and slightly less humid conditions.
&&
.AVIATION...(For the 18Z TAFS through 18Z Saturday afternoon)
ISSUED AT 136 PM EDT FRI SEP 16 2016
VFR conditions will prevail through the TAF forecast period.
Isolated to scattered showers and thunderstorms are possible this
afternoon into this evening, mainly over the southern part of the
forecast area. However the likelihood of any given spot being
affected is low. With this in mind decided to carry VCTS in the
LOZ and SME TAF for a few hours late this afternoon into the early
evening. Looking further ahead, the best chance for showers and
thunderstorms still looks to be Sunday.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...SBH
LONG TERM...JVM
AVIATION...SBH
Area Forecast Discussion
National Weather Service Morristown TN
304 PM EDT FRI SEP 16 2016
.SHORT TERM (This Afternoon through Saturday)...
The heat across the area continues to be relentless. Temperatures at
3pm are in the upper 80s and low 90s across most valley locations.
Current water vapor imagery and RAP upper air analysis indicates
that the upper level ridge axis is beginning to shift to the east
with a trough moving eastward across the Northern Plains. Radar
returns are currently limited to areas across the higher elevations
where there is some additional orographic lift. PW values are in
the 1.6-1.7 inch range, which is around the 90th percentile for
mid-September. At the surface, a weak surface trough is near the
Ohio River. Although, moisture values are higher than yesterday,
the coverage of showers and storms are still limited due to the
lack of any synoptic support or low-level boundary. For tonight,
expect any ongoing shower/storms will quickly come to an end after
sunset. With the higher low-level moisture in place, patchy fog
will be possible later tonight near sunrise.
On Saturday, another warm day is expected with 500 mb heights still
around 590 dm. Models indicate that the best moisture will be across
SW VA where PW values will be around 1.5-1.6 inches. This is where
there is a slight chance to chance for showers/storms. A cold front
will move into the Ohio and Mid-Mississippi River valleys late in
the day. For the most part, expect most of the shower/storm activity
will hold off until after this timeframe. High temperatures on
Saturday will continue to be above average with highs still in the
upper 80s to low 90s for most valley locations.
.LONG TERM (Saturday Night through Friday)...
Some of the best rain chances during this long term forecast will
likely come at the beginning. A frontal boundary will approach the
area from the northwest and ahead of this winds will switch to out
of the southwest and bring in higher moisture. With the increased
moisture we could see showers through the weekend and into next
week. Best timing for storms currently looks to on Sunday during the
actual frontal passage. Behind the front drier air from the north
will move in allowing temps to cool off just a bit through the first
half of the week before we rebound back too near 90`s for most of
the area by the weekend. Mostly sunny skies and dry weather will
remain the main story through the work week until next week when
another system makes a run at our forecast area.
&&
.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN 70 91 70 89 / 10 10 20 50
Knoxville McGhee Tyson Airport, TN 68 91 68 87 / 10 10 20 40
Oak Ridge, TN 68 91 69 86 / 20 10 20 50
Tri Cities Airport, TN 63 88 63 83 / 20 20 20 40
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...None.
TN...None.
VA...None.
&&
$$
MA/ABM
Area Forecast Discussion
National Weather Service Omaha/Valley NE
330 PM CDT FRI SEP 16 2016
.SHORT TERM...(Tonight through Monday)
Issued at 325 PM CDT FRI SEP 16 2016
Little in the way of impactful short term weather. Near surface
soil moisture is high across the area due to heavy rainfall Thursday
night into early Friday morning. RAP, SREF and HRRR and conditional
LAMP guidance each hinting at some patchy ground fog, with
visibilities perhaps dropping down into the 6 to 8 mile range.
Decided to introduce a period of patchy fog from about 09 UTC
through 13 UTC. Diurnal mixing will dissipate any ground fog that
may form.
Saturday night into early Sunday, there is a slight chance of
nocturnal convection, as short wave feature enhances isentropic
ascent 305-312K. Moisture appears limited to mid-levels so not
confident that coverage will be too great. As such kept PoPs
below slight chance.
Temperatures will be seasonal through the weekend, and forecast
guidance looked reasonable and accepted consensus. By late in the
short range, temperatures will be on the rise, as mid-level ridging
builds over the central U.S. Downslope component to wind will allow
max temperatures to jump 5-10 degrees from Sunday to Monday.
.LONG TERM...(Monday night through Friday)
Issued at 325 PM CDT FRI SEP 16 2016
Upper flow remains predominately zonal across northern plains,
with large scale H5 ridging entrenched over southern plains. H5
heights suggests temperatures will remain slightly above
normal through Wednesday. Deterministic and ensemble models are
consistent in moving a cold front across the region Wednesday
evening into Thursday. Best dynamic forcing will be well to the
north of the forecast area, and question how far south front will
push as it encounters mid- level ridging across the southern
plains. As such, some sort of boundary linger across the area
providing a focus for convection. Thermodynamic/diabatic effects
will be enough to generate some convection and consensus solution
of low chance PoPs entering amd remaining in the forecast from
Wednesday night into Friday looks reasonable.
&&
.AVIATION...(18Z TAFS for KOFK...KLNK and KOMA.)
Issued at 1225 PM CDT FRI SEP 16 2016
Mesoanalysis at 17z placed a cold front from northwest Iowa to
south-central Nebraska. This boundary will continue southeast
through the remainder of eastern Nebraska and western Iowa today
with west-southwest winds shifting to northwest. A shield of mid
and high-level cloudiness stretching from Kansas through east-
central and southeast Nebraska and western Iowa will translate
east.
&&
.OAX Watches/Warnings/Advisories...
NE...None.
IA...None.
&&
$$
SHORT TERM...Fortin
LONG TERM...Fortin
AVIATION...Mead
Area Forecast Discussion
National Weather Service Blacksburg VA
403 PM EDT Fri Sep 16 2016
.SYNOPSIS...
High pressure will keep a wedge in place over our area tonight.
By Saturday, high pressure will still be located in the area with
Tropical Depression Julia stuck offshore of South Carolina. A cold
front enters the Ohio and Mid Mississippi Valley Sunday, moving
through the mid-Atlantic states Monday.
&&
.NEAR TERM /THROUGH SATURDAY/...
As of 345 PM EDT Friday...
A dirty wedge continues to dominate the region as low clouds were
seen by most today. Some areas did see clearing over the course of
the day, but will more than likely cloud over again this evening
as little change to the pattern is expected through Saturday
afternoon. At that point, some clearing can be expected and
temperatures should rebound a bit through the mountains. Current
HRRR shows that the best chances for precip for the duration of
the day exist over the Grayson Highlands and the Northwest
Mountains of NC, however rainfall amounts look to be very minimal.
More widespread showery activity should be anticipated on Saturday
ahead of an upper level trof approaching the region.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY NIGHT/...
As of 300 PM EDT Friday...
The weather pattern remains blocked with high pressure over the
western Atlantic. This blocking pattern will keep Tropical Storm
Julia hovering off the southeast coast and a cold front sitting over
the midwest Saturday night. A northern stream upper level trough
will begin to push the cold front slowly across the Ohio Valley
Sunday, then over the Mid Atlantic States Sunday night into Monday.
Prefrontal showers may clip the Greenbrier Valley Saturday night
into Sunday afternoon, but the bulk of the widespread light rain
will move across with the front Sunday night into Monday. Not much
forcing with the passage of this front, but enough lift may squeeze
out a half of an inch /0.50/ of rain across southeastern West
Virginia and around quarter of an inch /0.25/ over the southwestern
Virginia and northwest North Carolina mountains. The flow becomes
westerly fairly quickly as the front tracks across the mountains
Monday morning to limit rainfall to under a quarter of an inch east
of the Blue Ridge. A secondary line of showers may develop over the
piedmont Monday afternoon. At this time, models have this line
developing well east of Blacksburg CWA and in the coastal piedmont
of Virginia. Showers will taper off from west to east Monday
afternoon as the upper level trough pivots over the region.
Temperatures will warm above seasonal levels until the frontal
passage Monday.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 330 PM EDT Friday...
A cold front slides across the region Monday night, but clouds will
likely remains as theta-e ridging lingers over the area. The upper
level trough is expected to become a closed low over the
southeastern states as it begins to interact with Tropical Storm
Julia. An upper level ridge will build east from the Gulf States
Wednesday and center itself over the Carolinas by next weekend. This
ridge could take Julia westward across Florida and into the Gulf of
Mexico. For the immediate area, this ridge will bring several days
of warmer than normal temperatures and little chances for rain.
&&
.AVIATION /20Z FRIDAY THROUGH WEDNESDAY/...
As of 730 AM EDT Thursday...
MVFR ceilings are pretty widespread through the region due to a
summer wedge that has set up. As of now, DAN is not trapped under
the stratus deck and should remain so through most of the TAF
period before clouds fill in again overnight. BLF is on the
western edge of the clouds and experiencing only partly cloudy
conditions. Plenty of uncertainty exists with the fluctuation of
cloud height and coverage in this situation. MOS guidance and
forecast soundings indicate that any locations that are broken out
now, or expected to will fall back to at least MVFR conditions
tonight. Fog is forecast for BCB exclusively due to persistence.
Extended aviation discussion...
Friday night into Saturday low level winds will veer to the south
in advance of an approaching cold front. Sub-VFR clouds may
persist Friday night along with isolated rain showers mountains as
Atlantic moisture gets lifted upslope across the Blue Ridge.
Appears best chances of seeing more widespread sub-VFR Saturday
into Saturday night will remain along the KBLF-KLWB corridor with
showers just ahead of the front. Otherwise should return to a
period of VFR elsewhere Saturday with deeper south/southwest flow
ahead of the front.
Sunday-Monday still looks unsettled as a cold front stays close
to the area. Expect threat of showers and storms with possible sub-VFR
cigs/vsbys. Anticipating VFR Tuesday with the front south of us.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...None.
NC...None.
WV...None.
&&
$$
SYNOPSIS...RCS
NEAR TERM...JR
SHORT TERM...RCS
LONG TERM...RCS
AVIATION...AMS/JR
Area Forecast Discussion
National Weather Service Tampa Bay Ruskin FL
335 PM EDT FRI SEP 16 2016
.SYNOPSIS...
19Z water vapor and H4 RAP analysis shows a broad region of weak
mid/upper level ridging over the eastern Gulf of Mexico and
Florida Peninsula. The weakness of the ridge is keeping the
overall suppression light, and the column overhead on the 12Z
KTBW sounding was quite moist. Dewpoint depressions through much
of the trop were small...and the PW value was over 2". The profile
did not suggest many negative factors toward deep convection, but
also did not indicate much potential for strong updraft leading to
intense convection. The other factor to note was the lack of winds
through the convective steering layers. Wind are almost
light/variable between 800-250mb. Convection that does develop
through early evening is not going to have much push behind it,
and therefore, slow movement and localized heavy rainfall
potential. However...what might limit the overall rain total
potential...is that very slow movement means rapid inflow cuttoff
and updraft dissipation once precip begins to fall.
At the surface...the peninsula is within a fairly weak pressure
gradient between ridging nosing down into the NE Gulf from
GA/Carolinas...and Tropical Storm Julia off the GA/Carolina
coasts. The light flow has allowed for sea-breeze circulations to
develop on both coasts and move inland. Parameterized and explicit
forecast guidance in agreement of a scattering of storms
developing through the early evening hours. As mentioned above,
any storms are likely to be slow moving...but also tend to dissipate
rather quickly due to the kinematics and thermodynamics aloft.
Temperatures are just about at their highs for the day in the
upper 80s to lower 90s.
&&
.SHORT TERM (Tonight through Saturday)...
Scattered evening storms dissipate within a few hours of sunset /
and or move offshore into the eastern Gulf. The remainder of the
overnight looks to have a seasonable yet warm forecast with low
temps in the low/mid 70 most spots...although mid/upper 70s will
be common at the beaches. Similar to past mornings...should see a
bit of patchy fog toward dawn...especially north of the I-4
corridor...however...no widespread or dense fog is anticipated.
Low level winds over the northern half of the peninsula do shift
out of the NE after midnight...and this direction with available
moisture and ridging aloft can be favorable at times for areas of
lower stratus to expand to the south and southwest toward the I-4
corridor of Polk/Hillsborough. Not much of an impact to the
sensible weather forecast, but potential impacts for the aviation
community and TAF forecasts.
The large scale synoptic pattern does not change much between
today and Saturday. One factor that will be monitored closely with
the 12Z Guidance package is the potential for some dry air arrival
aloft over the northern peninsula during the afternoon hours.
GFS/NAM/ECMWF all show a swath of drier column air (above approx
800mb) that rotates down into our northern areas around the
circulation of Tropical Storm Julia. By late in the day
Saturday...minimum thetaE values in the mid-levels range from
convectively very favorable values in the mid 330sK along and
south of I-4...to much less favorable mid 320sK up toward
Levy/northern Sumter counties. This is a fairly significant
moisture gradient, and one would think it will end up being
represented in the overall diurnal showers coverage. A thetaE of
325K is not an extreme low value by any means...but when compared
to readings further south, certainly suggest a more hostile
environment though updraft entrainment.
Given this drier swath of air...will have to keep rain chances
lower to the north of the I-4 corridor...especially the closer to
I-10 one travels, however, the environment does not support
completely removing all rain chances. Higher afternoon chances
for a passing storms will exit along and south of the I-4
corridor...in agreement with most explicit and parameterized
guidance ensembles. High temperatures for Saturday once again end
up a couple degrees above normal...with mainly lower 90s away from
the immediate coast.
&&
.LONG TERM (Saturday Night-Friday)...
An area of high pressure aloft over the region this weekend will
shift westward a bit over the south-central part of the country for
early next week before shifting back over the southeast for the end
of the week. At the surface, what is currently Tropical Storm Julia
will continue to linger off the Carolina coast in some form before
eventually weakening, but possibly not until the middle part of the
week. A fairly weak pressure pattern will be in place over Florida
until Wednesday, when a stronger area of high pressure shifts into
the midwest and then toward the northeast by Thursday and Friday.
As far as rain chances go, a relatively weak steering flow across
the area through Tuesday/Wednesday will lead to diurnally-driven
showers and thunderstorms, mainly in the afternoon and evening
hours. Once the stronger area of high pressure builds in to our
north, we will see a more dominant easterly flow setting up across
the area. This would give us a rainfall coverage pattern typical of
those days, which would mean scattered showers moving east to west
across the interior and then consolidating near the west coast later
in the afternoon and evening. Overall, though, scattered to numerous
showers and thunderstorms are in the forecast for each day. High
temperatures through next week will run in the upper 80s to lower
90s.
&&
.AVIATION...
VFR conditions prevail across west-central and southwest Florida
with a sct-bkn cumulus field. A scattering of showers and storms
can be expected through mid-evening. While it is too early to
determine which terminal might see a storm, any storms that do
develop are likely to be slow moving...meaning a longer heavy
rainfall threat under a specific cell. Storms fade by
02Z...followed by prevailing VFR conditions for the next several
hours. Late at night, pattern favors a few areas of lower stratus
potential arriving from the NE toward KLAL/KTPA after 08-09Z.
&&
.MARINE...
Weak high pressure nudges down into the eastern Gulf from the
Southeastern States. This ridge is holding what is currently
Tropical Storm Julia off the Carolina/Georgia coast. This storms
is not expected to move much through the duration of the upcoming
weekend...and should generally not impact our local waters. With
weak high pressure remaining in control...expect light winds and
low seas through the next several days...with onshore breezes
developing each afternoon.
&&
.FIRE WEATHER...
No significant fire weather concerns are anticipated through the
upcoming weekend. Generally light flow will remain in place across
the Florida peninsula...with abundant low level moisture to keep
relative humidity values above critical levels. We are likely to
see a daily scattering of afternoon storms...with temperatures and
rain potential near normal for this time of year.
Fog Potential...No significant areas of widespread or dense fog
are anticipated through the upcoming weekend.
&&
.Preliminary Point Temps/PoPs...
TPA 77 90 77 90 / 40 50 20 30
FMY 77 89 76 90 / 30 50 20 50
GIF 75 90 75 92 / 20 40 20 40
SRQ 77 88 76 89 / 40 30 20 30
BKV 75 91 73 91 / 30 40 20 30
SPG 78 89 78 90 / 40 30 20 30
&&
.TBW Watches/Warnings/Advisories...
FL...None.
Gulf waters...None.
&&
$$
SYNOPSIS/SHORT TERM/AVIATION/MARINE/FIRE WX...Mroczka
LONG TERM/DECISION SUPPORT...Carlisle
Area Forecast Discussion
National Weather Service Tulsa OK
315 PM CDT FRI SEP 16 2016
.DISCUSSION...
It has been an interesting radar evolution over the past several
hours...as we started this morning with two outflow boundaries
with which to focus storms. The western MCS weakened as it moved
into NE Oklahoma...and most spots received just light
precipitation. In fact...KTUL only received 0.02" since 12z with
KRVS picking up 0.05". Area mesonet sites show the highest amounts
were along the KS/OK border and just west of our CWA. The storms
forming along the northern outflow slowed their southward
propagation as the western MCS moved in and the upper wave
approached. The active area now is across western AR where
scattered storms have developed but will likely dissipate by early
evening. Water vapor shows the upper wave over eastern OK is
quickly moving east and will take the moisture/lift with it.
Have lowered pops for the overnight period based on current radar
trends, stabilized airmass, and departing large scale forcing with
upper wave. Synoptic front is in KS...with a convectively
generated boundary in the TX panhandle. Will have to monitor these
areas for development...but these are the best options for any
storms overnight. Although the global models suggest precipitation
overnight and Saturday...the last few runs of the experimental
HRRR are not. Will keep low chance pops just in case for Saturday
if anything is able to develop overnight.
Otherwise...by Saturday afternoon...upper trough will be across
the Great Lakes. By Sunday we will be drying out as trough axis
is east of us. Upper ridge builds in for Monday/Tuesday with
another round of hot days with highs in the upper 80s/90s.
Corfidi
&&
.PRELIMINARY POINT TEMPS/POPS...
TUL 68 87 65 87 / 40 20 20 20
FSM 71 90 69 88 / 30 30 10 40
MLC 70 89 67 88 / 20 20 20 40
BVO 65 86 61 85 / 50 20 20 20
FYV 65 85 62 82 / 40 30 10 20
BYV 66 82 64 83 / 30 40 10 20
MKO 69 87 66 86 / 40 20 20 20
MIO 66 85 62 84 / 40 20 10 20
F10 69 87 68 87 / 40 20 20 40
HHW 71 91 70 91 / 20 20 10 30
&&
.TSA Watches/Warnings/Advisories...
OK...None.
AR...None.
&&
$$
SHORT TERM...07
LONG TERM....06