Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 10/07/19
Area Forecast Discussion
National Weather Service Goodland KS
455 PM MDT Sun Oct 6 2019
.SHORT TERM...(This evening through Monday)
Issued at 155 PM MDT Sun Oct 6 2019
RAP 500 mb heights and water vapor show a weak upper disturbance
pushing across the region today. As a result, some light rain
showers moved through areas along the Nebraska border this morning
and early afternoon. Around 2 PM MDT, northerly winds were at 10
to 15 mph, with occasional gusts up to 25 mph. Skies were clearing
across the region as showers exited to the east. Temperatures
ranged in the upper 50s to low 60s.
Skies continue to clear from west to east the remainder of the
afternoon. For Sunday night, surface high pressure is anticipated to
move over the area, leading to light winds, clear skies and a drier
air mass. These conditions will allow for temperatures to fall into
the middle 30s across most of the region overnight/early Monday
morning, making frost a concern once again. Have expanded the
Frost Advisory to include the entire region.
A lee side surface trough along the Front Range strengthens on
Monday as the high pressure moves out. Winds turn to the south and
filter warmer air into the area, with highs mainly in the low 70s
under sunny skies. Relative humidities are forecast to fall between
15 and 20 percent for a couple of hours in the afternoon. South
winds gusting around 25 mph make this a tough call, but it appears
that conditions will fall short of meeting criteria for a highlight
at this time. This will need to be monitored, and elevated fire
weather conditions are anticipated along and west of the Colorado
border Monday afternoon. Winds lighten some Monday night as
temperatures fall into the upper 30s to upper 40s.
.LONG TERM...(Monday night through Sunday)
Issued at 304 PM MDT Sun Oct 6 2019
Synopsis: A busy long term period, with several nights of Frost
Advisories expected, potential Freeze Advisory, and our first snow
of the season Thursday Night.
Tuesday, westerly flow aloft will prevail as the trough aloft
exits our area. Warmer and dryer conditions will move in bringing
our daily highs to the mid to upper 70s. Wednesday, flow aloft
will begin to turn southwest ahead of a strong pacific NW trough
located over Washington State. The system will not arrive until
Wednesday night, so we will see daily highs once again climb up
into the mid to upper 70s. Went with NBM at this time for the
timing of the FROPA as guidance is still a little inconsistent
with the arrival. At this time, introducing pops at 00Z Thursday.
Rain will start off and our NW CWA will see some wintry mix going
into the overnight hours.
Rain, wintry mix, and snow chances will continue through Thursday
and Friday mid-morning. Thursday and Friday we will see a wide
varying gradient of daily highs and lows before the front makes it
through the area. Both days will have highs from the low 30s to
upper 40s, with overnight lows on Thursday night in the lower 30s
to upper 40s, followed by Friday night lows in the upper teens to
lower 30s.
Come Saturday, after the system completely exits our area,
ridging will begin to build back in over central Arizona. We will
begin to warm back up with highs climbing to the 50s on Saturday
and to the 60s on Sunday, with lows in the upper 20s to upper 30s
each night.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 455 PM MDT Sun Oct 6 2019
For KGLD and KMCK, vfr conditions through the period. Light winds
at taf issuance will continue the night with increasing south to
southwest winds during the day Monday. Wind gusts to 25kts or so
are expected. Winds subside and lose the gusts around 23z.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...Frost Advisory from midnight MDT /1 AM CDT/ tonight to 8 AM MDT
/9 AM CDT/ Monday for KSZ001>004-013>016-027>029-041-042.
CO...Frost Advisory from midnight tonight to 8 AM MDT Monday for
COZ090>092.
NE...Frost Advisory from midnight MDT /1 AM CDT/ tonight to 8 AM MDT
/9 AM CDT/ Monday for NEZ079>081.
&&
$$
SHORT TERM...JBH
LONG TERM...EV
AVIATION...99
Area Forecast Discussion
National Weather Service Wilmington NC
924 PM EDT Sun Oct 6 2019
.SYNOPSIS...
High pressure will slowly shift off the coast this evening and
overnight. A cold front will move east across the area early
Tuesday, with seasonably cool and dry weather much of this week,
accompanied by a slow drying and warming trend into the weekend.
Another cold front will cross the coast Sunday.
&&
.UPDATE...
No significant edits were made with the evening updates.
&&
.NEAR TERM /THROUGH MONDAY NIGHT/...
High pressure ridging in from the NE US will give way during the
period as a cold front moves in from the NW. With onshore flow, the
approaching front and falling heights aloft as an upper trough moves
into the area, rain chances will gradually increase during the
period. Isolated showers will become more scattered Monday and
Monday night with some potential for thunder. Lows tonight should
fall to the low to mid 60s most areas with upper 60s nearer the
coast. Highs Monday will reach the lower 80s with mins Monday night
in the mid to upper 60s.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
Cold front in the area Tue pushes offshore around midday or so with
high building in from the north. Mid-level dry air spreads over the
region Tue following the front, but low level moisture will linger.
Skies will remain cloudy Tue with light rain/sprinkles lingering
into the afternoon. Confidence is low as far as measurable rainfall
goes, but certainly expect Tue to be damp. Highs Tue are tricky.
Forecast soundings suggest wedge setting up with low clouds and
drizzle Tue into Tue night and continuing Wed. A wedge would keep
skies cloudy, limiting heating. Highs would occur early in the day,
likely before noon, with temperatures falling in the afternoon. If
clouds were to decrease, even slightly, highs could easily rise into
the low 80s. Guidance continues to struggle with the strength of the
wedge and will go in the middle of the NAM/GFS/EC solutions, with a
slight nod to the cooler solutions.
Front pushes farther off the coast Tue night into Wed, but the
combination of lingering low level moisture and high wedging down
the coast will keep skies cloudy, but rainfall chances will be
limited. Highs will be right around climo, unless cloud cover is
less than expected. Low temps each night will be near climo, helped
by clouds and northeast winds.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
Brief mid-level ridging over southeastern Canada and New England mid
to late week keeps 5h cutoff low lingering off the East coast
through Sat. The resulting pattern aloft will maintain deep
northwest flow aloft with low level north to northeast flow.
Strength of northerly flow will be determined by strength of surface
low under the 5h cutoff and the high building down the coast. Late
in the week strong mid-level trough lifts from the west into the
Great Lakes region, driving a cold front across the region Sun.
Front is far displaced from the parent low and the lack of deep
moisture suggests the front will pass dry.
-Limited rainfall chances through the period due to lack of a
deep moisture.
-Temperatures near climo Thu rising above climo Fri and
remaining above climo through Sun, warmest on Sat.
&&
.AVIATION /01Z MONDAY THROUGH FRIDAY/...
The HRRR has been pretty consistent in bring in nocturnal
showers from offshore. Very warm water will support this
scenario, with a possible land breeze right at the coast. Expect
MVFR conditions in the showers overnight. Monday, more showers
are expected with low LFCs along the coast.
Extended Outlook...Predominately VFR. Some light showers are
possible on Monday and Tuesday, with MVFR ceilings again possible.
Fog/stratus possible Wednesday and Thursday mornings.
&&
.MARINE...
E winds of 10 to 15 KT will become SE Monday and turn to the NE
Monday night. Seas of 4 to 6 FT are expected through the period
with the 6 footers expected in the SCA area northern waters.
Northeast flow will dominate Tue through Fri with slow moving low
pressure looping off the East coast. On Fri confidence in both the
location and strength of the low is limited, but expect winds will
back to more northerly as inland ridging weakens. Gradient starts to
relax late in the week with speeds dropping under 15 kt Fri. Speeds
will be 15 to 20 kt Tue through Thu with solid 20 kt possible Tue
night through Wed night. Seas in the realm of Small Craft Advisory
are possible Tue into Thu followed by a decreasing trend Thu and
Fri. Northeast to east wind wave around 5 seconds will be the
dominant wave feature with periods gradually increasing late in the
week.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...None.
NC...None.
MARINE...Small Craft Advisory until 7 AM EDT Tuesday for AMZ250-252.
&&
$$
SYNOPSIS...ILM
UPDATE...8
NEAR TERM...RAN
SHORT TERM...III
LONG TERM...III
AVIATION...43
MARINE...III/RAN
AREA FORECAST DISCUSSION
National Weather Service Wilmington OH
1019 PM EDT Sun Oct 6 2019
.SYNOPSIS...
A cold front will slowly move southeast overnight. Precipitation
will end from northwest to southeast Monday as the front
continues to move away. High pressure will build into the Great
Lakes Monday night. The high will then extend across the area
into mid week.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
Cold front is located in the southeastern parts of the fa,
running from Mason County KY up to Pike County OH. Thunderstorm
activity appears to be limited to the vicinity of front. As the
front continues to slip southwest overnight, so will the chance
of thunder.
Behind the front and thunderstorms is an area of showers. The
backedge has worked to about the Ohio/Indiana border. Latest
runs of the RAP and HRRR redevelop the activity around
Louisville and lift it northeast across southeast Indiana later
tonight. This will also help keep the PoPs high for locations
farther east in the cwa.
Still looking at temperatures falling into the lower to mid
50s tonight.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
On Monday, the mid level trough will cross our region. As this
occurs, precipitation will gradually shift southeast and should
exit our southeast zones during the afternoon. Surface high
pressure will begin to build into the region from the west late
in the day. Pcpn and lingering clouds will hold highs down in
the southeast (upper 50s to around 60) while the northwest zones
will being to see some filtered sunshine in the afternoon,
which will result in highs in the upper 60s.
For Monday night, the center of the surface high will build east
into the Great Lakes. Drier air is expected to filter south and
east along with clearing skies. Lows will fall into the lower to
mid 40s.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
Long term period will likely have an increasingly amplified
pattern, with temperatures rising through the work week ahead of
a deep surface low pressure system likely impacting sensible
weather for the weekend.
Low impact weather dominates Tuesday through Friday as surface
high pressure ridge extends over the CWA from the high`s center
to the northeast. As the high exits toward New England, low
level flow shifts from the east on Tuesday around to a return
southeasterly flow on Wednesday and Thursday. Temperatures will
rise through this period from near normal on Tuesday to 6-8
degrees above normal by Thursday.
Models continue to disagree somewhat for Friday/Saturday as a
"temporary" blocking pattern sets up off the East Coast and an
elongated upper level trough closes off over the northern Plains
states. The development and position of the upper level low
varies widely by deterministic model, and still is varying run-
to-run for each model. This leads to differences in position of
the associated cold front. On Friday, low level winds veer to
the south ahead of tightening gradient, and in full warm air
advection mode. The GFS pushes the cold front through the CWA
early Saturday morning, providing a post-frontal Saturday with
rain and temperatures falling through the 50s, while the Euro is
still running a few hours behind. Another interesting note is
that through the 06Z run, the deterministic GFS positioned the
front well ahead of GEFS members, with most members lagging the
thickness falls by 12-24 hours. Based on this, will trend slower
with precip and temp falls as well.
Models agree wind gusts in the cold air advection will be
something to keep an eye on, so will do that. For now,
deterministic runs through BUFKIT show 25-35 mph behind the
front, but will trim that back a bit based on lower than normal
confidence with timing.
&&
.AVIATION /02Z MONDAY THROUGH FRIDAY/...
The tafs are now on the northside of the cold front and surface
winds are generally from the north northwest. Showers and maybe
a thunderstorm will affect the region this evening as upper
level support associated with an advancing H5 s/w affects the
area.
Limited the mention of thunder to the srn tafs through 04Z, when
the threat should work east of the tafs. During this time
showers will affect all the tafs. As lower levels of the
atmosphere reach saturation ceilings are expected to drop down
to MVFR later this evening. KDAY is expected to stay VFR as it
will be on the northern edge of the better pcpn.
Between 09-12Z the deeper moisture will begin to be shunted
eastward. This will allow drying to begin from west to east.
Precipitation will also see a west to east trend, with the back
edge of the precipitation moving through the I-71 corridor
around 12-14Z. As all this occurs, ceilings will begin to rise,
reaching VFR between 14Z and 18Z.
While the low clouds dry out, some cirrus will linger through
18Z, when high pressure building in from the west, will scatter
that out too.
OUTLOOK...No significant weather expected.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...None.
KY...None.
IN...None.
&&
$$
SYNOPSIS...Hickman
NEAR TERM...Sites
SHORT TERM...Hickman
LONG TERM...Hogue
AVIATION...Sites
Area Forecast Discussion
National Weather Service Lincoln IL
651 PM CDT Sun Oct 6 2019
.SYNOPSIS...
Issued at 238 PM CDT Sun Oct 6 2019
A cold front near the Ohio Valley, will cause unsettled weather to
continue south of the I-70 corridor, into tonight. Farther north
dry weather will prevail for central Illinois. The front will push
well southeast of the area on Monday, as high pressure moves in.
This high will provide dry and mild weather through mid-week.
&&
.UPDATE...
Issued at 651 PM CDT Sun Oct 6 2019
A short-wave trough noted on 2330z/630pm water vapor imagery over
Nebraska/Kansas is producing a shield of mid-level cloudiness
across central Illinois early this evening. Despite a very dry
boundary layer, a narrow band of 35-40dBZ radar echoes along/east
of the Illinois River has yielded sprinkles at a few ob sites.
With HRRR showing this band shifting eastward with time, think a
few sprinkles may be observed everywhere east of the Illinois
River throughout the evening. Further south, a weak wave of low
pressure tracking along a nearly stationary frontal boundary just
south of the Ohio River will bring scattered showers to locations
along/south of I-70. As the Nebraska/Kansas wave tracks eastward,
skies will eventually clear across the Illinois River Valley
shortly before midnight...then further east to a Danville to
Taylorville line overnight.
&&
.SHORT TERM...(This evening through Monday)
ISSUED AT 238 PM CDT Sun Oct 6 2019
Cold front has stalled near the Ohio River this afternoon and will
remain nearly stationary tonight as a shortwave lifts northeast
into the Ohio Valley. This will cause frontogenesis north of the
boundary, which will produce periods of showers south of I-70,
into tonight. A few embedded thunderstorms are possible into
early evening. After the shortwave lifts out the rain will
diminish late tonight.
Farther north, satellite imagery reveals a large area of mid to
high level clouds, associated with a sheared shortwave and mid
level trough axis over the upper Midwest. This area of cloudiness
will continue shifting southeast, affecting the area through this
evening and diminishing after midnight as the upper level forcing
slides east. With clearing late, lows should drop into the lower
40s west of the IL River. With clouds hanging strong in SE IL,
lower 50s lows will be common.
An excellent stretch of fall weather will begin across the entire
area on Monday. High pressure over the central Plains begins to
shift east, providing light winds and dry and mild weather. Upper
60s/lower 70s highs expected.
.LONG TERM...(Tuesday through Sunday)
ISSUED AT 238 PM CDT Sun Oct 6 2019
The upper level pattern through mid-week features a deepening
trough over the western U.S. with a closed low forming over the
northern Rockies Wednesday. Downstream, upper level ridging
amplifies over the Midwest, while a surface ridge axis extends
from the Great Lake southwest over the local area. This to produce
dry and gradually warming temperatures, reaching a few degrees
above normal by Wednesday.
The pattern turns more active for Thursday and Friday as the
closed low rolls east, inducing lee cyclogenesis. The first
classic fall cyclone of the season is forecast to track through
the Plains and upper Midwest, putting us on the warm side of the
storm. Warm/moist advection will increase showers and isolated
storms from the west Thursday/Thursday night, while highest pops
and thunder chances accompany the cold frontal passage on Friday.
GFS is in better agreement with EC solution of a Friday frontal
passage, though timing will be key to another day of much above
normal temperatures, and thunderstorm timing. Regardless, after
the front sweeps east, blustery westerly winds will advect in the
coldest airmass of the season. 850mb temps are progged to dip as
low as -2 to -5C Friday night and Saturday. The deep closed low is
forecast to spin over the northern Great Lakes through the
weekend. This would keep well below normal temperatures in place,
with upper 30s lows and 50s highs common.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 635 PM CDT Sun Oct 6 2019
VFR conditions will prevail through the entire 00z TAF period. A
short-wave trough evident on latest water vapor imagery over
Nebraska/Kansas is creating a shield of mid-level cloudiness
across central Illinois early this evening. These clouds are
depicted quite well by the NAM 700-500mb layer RH field, so will
be following this closely for the cloud forecast. As such, have
included OVC120 at all sites initially...with clearing arriving at
KPIA by 06z...then further east to KDEC/KCMI by 09z. Skies will
then remain clear for the remainder of the period. Winds will be
light/variable this evening, then will become NW at 5-10kt at all
sites on Monday.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Barnes
SYNOPSIS...25
SHORT TERM...25
LONG TERM...25
AVIATION...Barnes
Area Forecast Discussion
National Weather Service Key West FL
1047 PM EDT Sun Oct 6 2019
.DISCUSSION...
A turn to wetter weather is expected over the next 24-30 hours.
The wind field shown by surface obs depict an inverted trough axis
off the Southeast Florida coast this evening. Loops of radar
imagery and PW imagery both show a westward-moving spin as well,
with an increase in PW values within the trough. Have increased
PoPs late tonight over the Upper Keys to account for an increase
in showers behind this vort lobe.
On Monday, a broad east-west trough currently near the south coast
of Cuba will lift northward across the Keys. MIMIC PW imagery
currently shows a sharp increase in moisture south of the trough
axis, and this air mass will arrive over the Keys as the trough
passes. Recent mesoscale models and the 18z NAM spread precip
across nearly the entire island chain by mid- day Monday. The 12z
ECMWF holds off until Monday evening, and the 18z GFS and
experimental 00z Caribbean HRRR splitting the middle with an
afternoon arrival anticipated. Have conservatively nudged PoPs on
Monday from 20 up to 30 percent, with room for the next shift to
adjust the forecast even wetter.
&&
.MARINE...
Wind speeds are on a decreasing trend this evening. Have therefore
been able to drop the Small Craft Exercise Caution headline for
all marine zones except the Straits for the rest of tonight.
From synopsis, a weak trough of low pressure stretches from the
Bay of Campeche to the Bahamas. The portion of this trough
currently over Cuba will lift slowly northward through Monday. By
Tuesday, this trough axis will stall to the north of the Florida
Keys. High pressure will build southward down the Sunshine State
Thursday through Friday.
&&
.AVIATION...
VFR conditions will prevail at both terminals through at least
Monday morning with continued dry conditions and light east winds
less than 10 knots. Sometime late Monday morning, a passing shower
cannot be discounted. Also during the morning, BKN clouds near FL200
to FL160 will build into the region. This will both limit sunshine
and indicate showers and possible thunderstorms affecting either or
both terminals during Monday afternoon. East winds near 10 knots
with occasional gusts near 20 knots starting Monday afternoon.
&&
.KEY WATCHES/WARNINGS/ADVISORIES...
FL...None.
GM...None.
&&
$$
Public/Marine/Fire...Haner
Aviation/Nowcasts....Chesser
Data Collection......DR
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Area Forecast Discussion
National Weather Service Memphis TN
940 PM CDT Sun Oct 6 2019
.UPDATE...
A cold front that pushed into the Mid-South this afternoon has
slowed its progression southeastward and is now nearly stationary
along the I-40 corridor. Showers and thunderstorms will continue
to stream northeastward along the front during the overnight
hours. This may lead to flash flooding in areas that have already
seen a lot of rain this evening. An upper trof will swing into the
area by Monday morning which will allow the front to start moving
again. Cooler temperatures are not that far away as temperatures
have dropped into the 50s across Missouri and even the last ob at
Corning, Arkansas showed a temperature of 59 degrees. May tweak
POPS and temperatures slightly. Otherwise, current forecast looks
good.
KRM
&&
.DISCUSSION... /issued 250 PM CDT Sun Oct 6 2019/
Surface analysis this afternoon places a cold front from Southern
Indiana back through Southeast Missouri, Central Arkansas, and
into the Red River Valley of Texas and Oklahoma. KNQA WSR-88D
radar trends have shown an increase in scattered showers and
thunderstorms across the Mid-South in the past couple of hours. As
of 2 PM CDT, mostly cloudy skies prevail across the forecast area
with temperatures ranging from the 70s to around 80 degrees north
of I-40 and middle 80s to around 90 degrees elsewhere.
Short term models including Convective Allowing Model (CAM)
solutions indicate the aforementioned cold front will move
through the Mid-South tonight with better coverage of showers and
thunderstorms mostly behind the front. A few strong thunderstorms to
perhaps a severe thunderstorm is possible mainly through early
this evening with damaging winds as the primary threat for any
thunderstorms that reach severe limits.
Much cooler and drier air will filter into the Mid-South on
Monday with highs struggling to reach the lower 70s. A shortwave
ridge will bring mainly rain free weather and moderating
temperatures through mid-week.
Long term models continue to indicate southwest flow aloft
returning to the Lower Mississippi Valley late this week ahead of
a deep upper level trough and cold front that will move into the
Middle and Lower Mississippi Valleys late this week into the start
of next weekend. Model run to run continuity problems continue to
persist for the Thursday night through Saturday time frame
resulting in a slightly slower trend than previous forecasts and
lower rain chances. These rain chances will likely needed to be
raised accordingly once models converge on better timing of the
next cold front in subsequent forecasts.
CJC
&&
.AVIATION...
00Z TAFs
Frontal-forced convective line was lifting through AR at 23Z,
an hour or two earlier than the HRRR (the better performing member
of the CAMs) depicted. A weak southerly jet above FL020, and the
position of an upper jet core over the northern Ohio Valley will
help sustain scattered TSRA well to the rear of the advancing
surface front through late evening.
Deepening frontal inversion and waning elevated instability should
limit TS potential at all but TUP after 09Z. Low MVFR ceilings
will likely be the main impact toward sunrise, followed by a slow
transition to VFR from northwest to southeast on Monday.
PWB
&&
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...None.
MO...None.
MS...None.
TN...None.
&&
$$
Area Forecast Discussion
National Weather Service Marquette MI
745 PM EDT Sun Oct 6 2019
.SHORT TERM...(This evening through Monday)
Issued at 409 PM EDT SUN OCT 6 2019
Water vapor and RAP analysis show a mid-level trof extending from
northern Ontario to the central Plains. Within the trof, a couple of
shortwaves are approaching Upper MI, one in northern MN and the
other dropping se thru southern Manitoba. In the wake of the
shortwave that passed last night and which is now over southern
Hudson Bay, it`s been a breezy day across the fcst area with winds
gusting to 25-35mph for the most part, but up to 35-45mph on the
Keweenaw. KCMX gusted to 48mph today, and out on Lake Superior, the
strongest observed wind gust was 60mph at Stannard Rock. While the
morning turned sunny across the fcst area, clouds have rapidly
developed this aftn due to combination of daytime heating and
approaching shortwave from MN. Didn`t take long for sct shra to
develop either.
Gusty winds will continue for the next several hrs before subsiding
toward sunset. Otherwise, as upstream shortwave over MN moves
closer, expect sct shra to continue to develop. Latest SPC
mesoanalysis shows SBCAPE up to around 200j/kg. So, not totally out
of the question that there could be a rumble of thunder. Second
shortwave currently over southern Manitoba will be over Upper MI at
12z Mon. This wave will help to maintain isold/sct -shra thru the
night though pcpn should take on more of lake enhanced look with
time due to the combination of cyclonic flow, weak synoptic forcing
and 850mb temps falling to around 0C over sfc water temps ranging
from 9-13C. The lake enhanced shra overnight will affect areas
favored by w to wnw low-level winds. Expect low temps in the 40s.
On Mon, with departure of shortwave, ongoing lake enhanced shra into
the ne fcst area under wnw winds will end by 18z. Daytime heating
will likely lead to an expansion of clouds in the morning to mostly
cloudy for much of the area before 850mb thermal trof begins to
shift e. Clouds will then decrease from w to e in the aftn. High
temps will be in the 50s.
.LONG TERM...(Monday night through Sunday)
Issued at 409 PM EDT SUN OCT 6 2019
Overall, the main forecast highlights moving forward this week are:
late-season warm up with temperatures running 5-10 degrees above
normal for this time of year, and the arrival of a potent storm
system progged to impact the region late in the week/next weekend.
This storm system will bring with it the potential for moderate to
heavy rain late in the week, windy conditions, and the potential for
the seasons first snowflakes out west and plummeting temperatures
over the weekend.
Monday night return flow becomes established from west to east
across the region as surface ridging center over lower Michigan
slides eastward over the New England area. Expect this return flow,
warm air advection regime to remain in place throughout much of the
week as warm air advection increases, building the ridge over
eastern Canada and a weak trough becomes further established off the
coast of New England, essentially forming a weak rex block over the
Northeast. This will keep the Upper Peninsula sandwiched between
surface ridging well to our east, and a developing open wave/surface
trough well to our west. Therefore, expect breezy southerly winds to
accompany the warming trend through much of the week. Afternoon
highs are expected to warm into the 60s, could see some downsloping
effects further warm temperatures in some locations. Overnight lows
will remain fairly mild, especially as better moisture arrives later
in the week and given the breezy overnight conditions expected.
Given the orientation of the surface pressure fields, magnitude of
the pressure gradient and enhanced winds off the surface we will
likely see wind gusts in excess of 20 mph throughout the week. Given
the warm air advection and reduced insolation this time of year, it
may end up being more intermittent gusts then persistent at times.
Late Thursday through the weekend still looks to be the time period
within the extend to keep a close eye on. While some timing is
addressed below, please note that as we get closer the forecast will
continue to be refined as confidence grows. A deep, potent trough
will dig across the central CONUS, before lifting north across the
Upper Great Lakes and eventually transitioning into a cutoff low. As
the main trough digs south across the central CONUS, late Thursday
we will start to see the return of better, deeper moisture and PWATs
approaching the 90th percentile to near-record high for this time of
year. Increasing large-scale lift, along with a strong baroclinic
zone will allow the potential for moderate to heavy rain with the
first wave of precipitation arriving Thursday night through Friday.
With the moisture transport aimed north to south during this time
period, it is possible that we could see some training precipitation
and decent rainfall amounts. Opted to leave thunder out of the
forecast. With the pressure gradient increasing further during this
time period as well, stronger south to southeast winds will be
possible.
Late Friday into the weekend, longwave troughing will start to pivot
across the Upper Mississippi Valley and lift north eventually
becoming cutoff. This will favor cyclogenesis along the northern
edge of the open wave/baroclinic zone. As quickly as the low
pressure system develops and deepens, it quickly becomes occluded
and slowly pivots across the Upper Great Lakes through the weekend.
As the colder air wraps around the system, it is possible that we
could see some wrap around snow make it into western parts of Upper
Michigan. Further to the east, a potent dry slot looks to develop.
When the cold air advection arrives, given the occluded nature of
the system we will be under a unique southwest flow regime so don`t
expect much in the way of a lake-component to the snow potential
through Saturday. By Saturday night and Sunday, or rather depending
on when the main cutoff low starts to gradually push eastward across
Lake Superior, we will start to see more of a west-southwest to west
flow regime setting up, which would favor more of a lake-component
and additional chance for snow out west. The longer the cold air
aloft lingers, it does look to gradually modify, so when timing
becomes more clear, will need to see how moisture and thermodynamics
are looking for lake-enhanced snow potential towards the latter half
of the weekend. On top of the chance for the first snowflakes of the
season, temperatures will certainly plummet behind the occluded
front with daytime highs over the weekend expected to be 10+ degrees
below normal for this time of year and it does still looks to be a
fairly windy. Certainly a time period to keep a close eye on as we
get closer, especially if you have any outdoor recreational plans
this weekend.
&&
.AVIATION...(For the 18Z TAFS through 18Z Monday afternoon)
Issued at 130 PM EDT SUN OCT 6 2019
VFR conditions should prevail thru this fcst period at
KIWD/KCMX/KSAW. However, there is some potential for a period of
MVFR cigs at KCMX late tonight and at KSAW Mon morning as an
increase in low-level moisture occurs for a time following a
passing disturbance. Otherwise, winds will remain gusty at KCMX
tonight with gusts between 25-30 kt. An approaching disturbance
will generate isold/sct -shra into tonight. Only VCSH was included
in the fcst given the uncertainty on whether any of the shra will
impact the terminals directly. &&
.MARINE...(For the 4 PM Lake Superior forecast issuance)
Issued at 409 PM EDT SUN OCT 6 2019
Ongoing marginal gales (gusts to around 35kt) across portions of
western and central Lake Superior should end this evening. Westerly
winds won`t diminish much though as gusts to around 30kt will
continue across much of Lake Superior thru the night. Winds will
diminish more notably on Mon as sfc high pres ridge approaches. With
the arrival of the ridge Mon evening, winds will have fallen off to
mostly under 15kt. With the departure of the high pres ridge to the
e and a low pres trof moving out over the Plains for Tue/Wed,
southerly winds on both days will probably gust frequently to 20-
25kt, strongest over the e half of Lake Superior. Winds should begin
to increase a little on Thu as the low pres trof moves closer. Low
pres will then organize on the trof and lift n as it deepens,
passing over or just w of western Lake Superior on Fri. Depending on
the strength and track of the low, may be looking at s, sw to w
gales on Lake Superior Fri and/or Sat.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
Gale Warning until 10 PM EDT this evening for LSZ243-244-263-264-
266.
Gale Warning until 9 PM EDT this evening for LSZ242.
Lake Michigan...
None.
&&
$$
SHORT TERM...Rolfson
LONG TERM...Ritzman
AVIATION...Voss
MARINE...Rolfson
Area Forecast Discussion
National Weather Service Shreveport LA
1024 PM CDT Sun Oct 6 2019
.SHORT TERM.../Tonight through Monday/
We have updated the forecast with short term progs for sky, winds
and dew points. The cold front is just now edging into the cwa in
our NW corner with sfc gusts to 34KT at Idabel. The boundary will
spread SE across the four state area bringing most of any
rainfall during the overnight hours. The HRRR kind of backdoors
some activity out of AR in LA with more development along I-30
after midnight. The new 00Z NAM is very similar with much light
QPF and pockets of downpours. We will stay pat on our high pops
tonight. No changes to pops per say aside from making an overnight
grid from 03-12Z to relieve some excess after midnight wording.
Get ready here comes fall overnight with 50s areawide first in the
morning, while still under clouds with a wind chill. /24/
&&
.PREV DISCUSSION... /issued 711 PM CDT Sun Oct 6 2019/
AVIATION...
For the ArkLaTex terminals, expect shifting and gusty winds
overnight with a decent fropa. Shwrs/isold TS 03-06Z along I-30
and shifting down across I-20 by 09Z and KMLU/KLFK shortly after.
South winds will shift to N/NW10-20KT along the boundary and then
veer to N/NE 5-15KT. We will see MVFR over the cooler surface only
slowly improve all morning, but lifting to VFR by Noon or so.
Some nice fall weather will ensue with yet another fropa on
Friday. /24/
PREV DISCUSSION... /issued 341 PM CDT Sun Oct 6 2019/
SHORT TERM.../Tonight through Monday Night/
Main feature dominating the short term is the cold front progged
to move across the region overnight. Front currently located along
the Red River from Wichita Falls Texas to Ardmore to Mcalester
Oklahoma. Thunderstorms forecast to increase in coverage along
the I-30 corridor late this afternoon. Surface heating combined
with a positively tilted mid-level trough will support convection
along the frontal boundary through the mid to late evening. MLCAPE
values of around 2000 J/kg will provide sufficient instability to
support strong thundersorms with isolated damaging wind gusts and
small hail.
Front to move across the region overnight with convection forecast
to evolve into widespread rain and embedded thunderstorms
areawide. North to northeast winds around 15 mph with higher gusts
will usher in much cooler air on Monday with high temperatures
forecast to only climb into the mid 70s. Post frontal low clouds
to persist through much of the day before gradually clearing from
the northwest during the afternoon. Overnight lows on Monday night
forecast to fall into the low to mid 50s. /05/
LONG TERM...Tuesday through Sunday/
High pressure will continue to build into the region bringing in
much cooler and drier air. Temperatures will struggle to reach the
80 degrees across the region on Tuesday with lows Wednesday morning
in the 50s areawide. The High shifts east Wednesday allowing for
southerly flow to return. Temperatures will warm into the low to mid
80s Wednesday and into the mid to upper 80s on Thursday ahead of
another approaching cold front on Friday. Can`t rule out strong to
severe storms with this front but there are some uncertainties with
this system at this time. Our region will likely see the coldest air
of the season thus far behind this front on Saturday and Sunday with
highs in the lower 70s and overnight low temperatures in the mid to
upper 40s. /20/
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 65 75 55 79 / 80 30 0 0
MLU 66 77 56 80 / 70 40 0 0
DEQ 58 75 50 76 / 90 20 0 0
TXK 59 74 52 76 / 90 20 0 0
ELD 59 74 51 79 / 90 30 0 0
TYR 63 75 55 79 / 80 30 0 0
GGG 64 75 54 79 / 80 30 0 0
LFK 69 75 57 80 / 50 30 0 0
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...None.
LA...None.
OK...None.
TX...None.
&&
$$
24/05/20