Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 06/12/19
Area Forecast Discussion
National Weather Service Charleston SC
923 PM EDT Tue Jun 11 2019
Low pressure will track along a stalled front over our area
from tonight into Wednesday. Another front will sweep through
Wednesday night, followed by drier high pressure into the
weekend. As the high shifts east over the weekend, a more
typical summertime pattern will return.
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
This Evening: Latest EMC RAP analysis from SPC shows PWATS of
at least 2.25 inches pooling across Southeast GA bands of
convective rains persist, resulting in periods of heavy rains
with pockets of torrential downpours ongoing along the lower
Savannah River region of the forecast area. We will continue the
Flash Flood Watch in place on this update package.
Overnight, parameters are coming together for additional heavy
rainfall further up the coast as low pressure organizes along
the stalled front and propagates to the northeast. Strong moisture
convergence ahead of the low in the vicinity of the front coupled
with high PWATS and lingering nocturnal instability will support
a corridor of moderate to heavy rainfall extending from the
Georgia coast north into the Charleston Metro Area, including
Savannah and Beaufort. High resolution guidance are similar in
showing the heaviest rains falling in the Savannah to Charleston
corridor with general rainfall amounts of 2-5 inches with some
members showing amounts in excess of 6 inches. Although flash
flood guidance values are still somewhat high and D1-D2 drought
conditions linger, the high PWATS within a weak steering flow
environment suggest the resulting convection will be efficient
in rain production which could overtake the 1-hr and 3-hr flash
flood guidance values.
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/...
Wednesday: The mid-levels will consist of a trough building
towards the East Coast. At the surface, a stationary front will
spread from southwest to northeast over our area. A cold front
is expected to follow this front northward with time, starting
out over GA during the morning hours and then moving over SC
during the afternoon hours. Deep moisture is in place with PWATs
over 2", which is well above normal. Models are in good
agreement showing widespread showers across our area during the
day. There is some instability, so thunderstorms are also
possible. But the severe risk is low. The slow motion of the
storms and the deep moisture will lead to periods of heavy
rainfall with QPF exceeding 1". Some areas could receive more,
especially if thunderstorms stay over the same area. This
certainly could cause flooding in the typical areas. But if too
much rain falls in too short a time, flash flooding cannot be
ruled out. Hence, the Flash Flood Watch continues into our time
period. The rainfall will wind down from southwest to northeast
from the late afternoon through the night as the low moves away.
Additionally, a cold front from inland will approach the area,
helping to push the moisture away. Expected remnant showers
along the coast by daybreak Thursday.
Thursday and Friday: A much different pattern is expected both
of these days as high pressure builds towards the area. Drier
conditions are expected with the high along with fair weather.
Highs both days will generally be in the 80s.
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
High pressure will maintain dry weather into Saturday before we
return to a more typical summertime pattern by Sunday as the
high builds off the coast. Temperatures and dewpoints will be
back near normal by Sunday, along with scattered showers and
tstms each day.
.AVIATION /01Z WEDNESDAY THROUGH SUNDAY/...
KCHS: It appears showers will linger in the vicinity of the
terminal through the evening with the risk for isolated heavy
showers. The chances for showers and tstms should increase as
convergence builds along coastal areas after midnight into
Wednesday as a wave of low pressure approaches. Periods of
flight restrictions are likely in periods of rains and lower
KSAV: Showers and tstms appear likely during the evening hours
as strong level moisture convergence ongoing after dusk this
evening. Showers and tstms may focus more up the SC coast late
tonight, then convective rains should fill back in on Wednesday
as an area of low pressure approaches from the southwest. Deep
moisture will persist and and periods of flight restrictions
are likely with passing convective rains.
Extended Aviation Outlook: Flight restrictions will come to an end
Wednesday night as high pressure builds into the area. VFR will
Tonight: East to southeast winds will prevail as low pressure
approaches from the southwest. Speeds will average 10-15 kt with
seas 2-3 ft. Stronger flow will reside along the border with
the South Santee River Entrance area where speeds may reach
15-20 kt overnight as the pressure gradient pinches between high
pressure north and developing low pressure to the southwest.
Gusty winds and heavy rainfall dropping vsbys to 1 NM will be
possible where areas of heavy rain develop.
Wednesday through Saturday: A cold front moving through the area late
Wednesday will increase the surface pressure gradient, causing
winds to become gusty. However, it appears wind gusts will stay
just below our Small Craft Criteria of 25 kt. High pressure will
build towards the area Thursday into Friday. Over the weekend
our area will return to a more typical summertime pattern with
the sea breeze during the day.
GA...Flash Flood Watch through Wednesday afternoon for GAZ100-101-
SC...Flash Flood Watch through Wednesday afternoon for SCZ042>045-
Area Forecast Discussion
National Weather Service Lincoln IL
836 PM CDT Tue Jun 11 2019
Issued at 836 PM CDT Tue Jun 11 2019
Scattered mid level clouds linger over the area this evening, as
high clouds edge in from the west. Main area of rain is still
southwest-northeast across Iowa, extending southwest into Kansas.
Our evening sounding is quite dry, and upstream at the Quad
Cities, their sounding is also dry below about 12,000 feet. So, it
will take a bit of time for our atmosphere to moisten up, given
that dew points fell into the 30s and 40s earlier this afternoon.
Tweaked the arrival time of the rain a bit overnight and mainly
emphasized the areas west of the Illinois River, though the latest
HRRR wants to hold it off until later into Wednesday morning.
Temperatures needed some minor adjustments, but are generally on
.SHORT TERM...(This evening through Wednesday)
ISSUED AT 335 PM CDT Tue Jun 11 2019
Mostly sunny skies and winds less than 10 mph prevailed this
afternoon across central and southeast IL. Nice weather today
compliments of 1022 mb high pressure over lower MI and western
Ohio. Temperatures at 3 pm were mostly in the lower 80s, with a
few upper 70s in eastern IL. Low dewpoints of 35-45 degrees over
central IL and mid to upper 40s in southeast IL.
High pressure will slip off to the east over NY/PA overnight while
an mid/upper level trof digs into the Midwest and drives a cold
front se toward the IL/IA border by 7 am Wed. Dry conditions
expected to continue over CWA this evening, then have chances of
showers moving into the IL river valley from I-55 nw during
overnight. Isolated thunderstorms possible toward dawn far nw.
Mid/upper level trof dig into IL by sunset Wed while a cold front
pushes se to near the IL river by 18Z/1 pm Wed and sweep thru
central and southeast CWA during Wed afternoon. Have chances of
showers and some thunderstorms spreading se with the front during
the day, though likely not reaching the Wabash river valley until
mid to late Wed afternoon. SPC day1 outlook keeps marginal risk of
severe storms sw of CWA over central/southern MO on Wed afternoon
and also from Dayton OH to Bowling Green KY east where better
instability will be Wed afternoon/evening. Rainfall amounts do not
look too much due to limited instability and lift over our area.
Lows tonight in the upper 50s to around 60F, except mid 50s east
of I-57 and in southeast IL. Highs Wed range from around 70F over
the IL river valley, to the upper 70s near the Wabash river.
.LONG TERM...(Wednesday night through Tuesday)
ISSUED AT 335 PM CDT Tue Jun 11 2019
The upper level trof near IL will keep a good chance of showers
and some thunderstorms around early Wed evening, then diminishing
from the west after sunset Wed night, with most of the convection
east of area overnight Wed night. Have just isolated showers near
the IN border overnight Wed night into Thu morning. Return of
sunshine during Thu with nw breezes, and highs in the lower 70s,
with some upper 60s ne of I-74.
1020 mb high pressure moves east into the mid MS and TN river
valley during Thu night, bringing fair skies and lighter winds. A
cool night in store Thu night with lows in the lower 50s, with
some upper 40s possible.
Another nice day expected on Friday as high pressure drifts off
the southeast Atlantic coast Friday afternoon. Expected partly to
mostly sunny skies, sw breezes and milder highs in the upper 70s
across central/se IL.
The 12Z forecast models continue to show an unsettled weather
pattern over the area from Friday night through Mon evening as a
frontal boundary moves into the area this weekend. The first
disturbance will track into the area during Friday night,
spreading chances of showers and some thunderstorms with highest
pops overnight Fri night into Sat morning where likely pops are.
Convection chances become more scattered by Sat afternoon, but
ramp up again during Sat night with next disturbance and low level
jet. Heavier rains possible Sat night across area. Yet another
round of convection expected Sunday afternoon and Sunday night, as
heaviest qpf is shifted into southeast IL. The frontal boundary to
shift se toward the Ohio river valley Mon and shifting higher pops
into southeast IL by then. Total rainfall amounts from Fri night
thru Mon evening range from 1-3 inches over central IL (lowest nw
of IL river), with higher amounts of 3-4 inches possible se of
.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 613 PM CDT Tue Jun 11 2019
Main forecast concerns come after about 10Z, as ceilings lower
ahead of a cold front. Showers and scattered thunderstorms will be
approaching KPIA toward 12Z or so, and reaching KCMI by 18-19Z.
Some of the forecast guidance suggests ceilings below 3,000 feet
close to KPIA/KSPI by early afternoon, before rising a bit
immediately ahead of the front. Will include a TEMPO period at
KPIA for now, but hold off elsewhere with greater uncertainty.
Coverage of thunder is low enough to preclude a mention at this
time, but will re-evaluate for the next TAF set as the evening
AREA FORECAST DISCUSSION
National Weather Service Jackson KY
1048 PM EDT Tue Jun 11 2019
Issued at 1048 PM EDT TUE JUN 11 2019
Forecast remains in good shape late this evening, with only minor
updates needed to freshen up the near term temps, dew points and
winds. Latest observations were already fairly well on track with
the forecast. Scattered thin high clouds continue across much of
the CWA as well. Still expecting these to increase in coverage
throughout the overnight. All updates were published and sent to
NDFD/web. A new set of zones was also sent out to change to
UPDATE Issued at 742 PM EDT TUE JUN 11 2019
A few changes made over the last couple of hours. First, with
ongoing high clouds cover across much of the CWA, went ahead and
bumped up sky cover to scattered for this evening, increasing to
broken late in the night. Also, while convection is favored for
tomorrow, the likelihood for 100 percent coverage in such an
environment is not likely...so bumped pops down to around 80. This
matched up better with neighboring offices, and still conveys the
likely to widespread wording. Finally, to make sure the near term
forecast was on track with the current conditions, the latest
observations were loaded in. This resulted in only minor
adjustments. All updates have been published and sent to NDFD/web.
A new forecast package will also be sent to reflect these changes.
.SHORT TERM...(This evening through Wednesday night)
Issued at 435 PM EDT TUE JUN 11 2019
High pressure is solidly in control across the region today,
providing a very pleasant day with pleasant temperatures and low
humidity. The surface ridge will exit to the east tonight with
return flow developing across the area into the day Wednesday.
Surface moisture is expected to recovery quite quickly on
Wednesday as a shortwave trough pushes into the region. Strong
positive vorticity advection ahead of the trough will across
Kentucky leading to shower and thunderstorm development across the
area through the day. A few sporadic showers may be possible as
early as 8 or 9 am in our southwestern zones as the moisture
advects into the area. Better rain chances will come in late
morning into the mid afternoon hours.
We are in a marginal risk for severe storms on Wednesday, with
lots of uncertainty revolving around the marginal risk. First, we
will have lots of cloud cover and that could limit potential
heating and instability. Second, the flow will be southeasterly
(downslope flow)across much of the area which may keep dewpoints
from reaching the low 60s, which is where they would need to be to
even have a chance at 1000-1500 J/kg MLCAPE. However, there may
be a better shot at the moisture getting into our far southern
zones (Bell, McCreary, Whitley counties). The 18z HRRR does show
some updraft helicity swaths across our southern zones, which has
trended more aggressive from the 12z HRRR. We have pretty good
shear over the region tomorrow, both directional and speed. Thus,
with developing convection it may be possible to sustain some
organized updrafts. The low level shear could even briefly be
supportive of a brief spin up tornado with the sig tor parameter
on the HRRR getting close to 1. Due to the low confidence on
instability, opting to stay away from mentioning any tors in the
HWO for now. The better threat will remain gusty winds and hail.
.LONG TERM...(Thursday through Tuesday)
Issued at 435 PM EDT TUE JUN 11 2019
Scattered rain showers will remain across the area into Thursday
afternoon as the mid/upper level trough continues to push east
across the area, with lingering moisture over the area. Did remove
thunder for Thursday as instability is much weaker on the 12z
model runs. A surface ridge will spread east across the area
Friday into Saturday, providing another drier stretch of weather.
With the ridge sliding east this weekend, return flow will allow
heat and humidity to return to the region. The weather will also
turn more unsettled late Saturday through Tuesday as the upper
level flow flattens out and trends more towards zonal flow.
However, several shortwaves may take aim on the area from Sunday
into Tuesday keeping the weather very unsettled. Forecast will
will be very wet and could see some local flooding issues at some
point early next week, but too far out at this time to have any
kind of confidence on the setup.
.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
ISSUED AT 748 PM EDT TUE JUN 11 2019
VFR conditions are expected throughout the night and into the
morning. High clouds are currently in place and will likely
continue through the night, thickening as we head into the day
Wednesday. Light and variable winds will also be present during
the overnight. However, during the day Wednesday, another cold
front and center of low pressure will begin approaching the area.
This will lead to an increasing chance of showers and
thunderstorms throughout the day, with best coverage expected
during the afternoon and evening. MVFR CIGS will be present at
times, mainly during mid-day, and any heavier shower or storm
could also result in the temporary reduction of VIS. Otherwise,
expect winds to remain light and variable, though can`t rule out a
storm producing a few gusts.
Area Forecast Discussion...UPDATED
National Weather Service Norman OK
1004 PM CDT Tue Jun 11 2019
Main update was to tweak PoPs for the overnight period. Most model
solutions continue upscale growth of storms into central and
southern Oklahoma overnight. While deep layer shear remains
strong, instability will be lacking. With relatively steep lapse
rates and shear, we could still see marginally severe hail and
wind through the night.
.PREV DISCUSSION... /issued 636 PM CDT Tue Jun 11 2019/
The June 12-13 00 UTC TAF discussion follows:
A cold front with a northerly wind shift is expected to progress
from north to south tonight. Showers and thunderstorms are
expected to develop along and move ahead of the front. Brief MVFR
ceilings and/or visibilities and gusty winds will be possible with
Northerly winds and VFR conditions are expected behind the front
by later tomorrow morning and through the afternoon hours.
PREV DISCUSSION... /issued 305 PM CDT Tue Jun 11 2019/
Main challenge for this forecast period is timing and extent of
showers and storms this evening and overnight.
NAM and RAP are much slower with the front tonight than the GFS
(with the ECMWF holding more of a middle position). Thinking is that
the GFS is too aggressive with surface dewpoints resulting in
earlier convection. Leaning toward the NAM / RAP solution (also
supported by most CAMs) with showers and storms entering northern
Oklahoma closer to 4 or 5 Z. These storms will continue overnight
with some severe risk as deep layer shear continues around 50 knots
and instability decreases slightly.
A shortwave moving through may trigger storms off the dryline
Thursday afternoon potentially impacting western Oklahoma.
Scattered rain chances will continue through early next week with
zonal flow. After a relatively cool Wednesday and Thursday,
temperatures warm into the weekend.
.PRELIMINARY POINT TEMPS/POPS...
Oklahoma City OK 61 81 55 77 / 60 20 0 10
Hobart OK 63 83 57 78 / 60 30 10 30
Wichita Falls TX 63 84 60 82 / 60 60 0 10
Gage OK 58 79 53 75 / 40 0 10 40
Ponca City OK 60 78 52 77 / 40 0 0 10
Durant OK 61 83 58 80 / 10 20 0 0