Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 04/28/19
Area Forecast Discussion
National Weather Service Bismarck ND
1047 PM CDT Sat Apr 27 2019
.UPDATE...
Issued at 1044 PM CDT Sat Apr 27 2019
The latest data (NAM, RAP, HRRR etc.) suggests a slight shift
south and the latest satellite and radar trends suggest a slower
onset of precipitation. Therefore, expanded precip chances a bit
south with this update and delayed precip chances southwest for a
few hours. Overall the big picture of the forecast has not changed
much and snowfall amounts remain highly dependent on temperatures
rather than placement of highest QPF.
UPDATE Issued at 750 PM CDT Sat Apr 27 2019
The upcoming storm and the impacts that will follow are on track
with previous thinking. Only slight adjustments were made based of
the latest data (generally just a few tweaks to timing and a
slight lowering of temperatures north tomorrow). Initially, we`ll
see mainly rain west this evening, then as diurnal cooling and
dynamic cooling link up we`ll see a mix of rain/snow and then
finally all snow across the north by tomorrow morning. Initial
accumulations tonight may be tempered by melting as ground
temperatures remain well above freezing. As the system moves
overhead tomorrow and dynamic cooling is maximized and combined
with intense precipitation rates snow should quickly accumulate
north, especially across higher terrains and on grassy surfaces.
Temperatures will flirt with critical thresholds tomorrow and a
degree or two can have huge impacts on precipitation type and
accumulations. Therefore, snow amounts and road conditions could
vary wildly and change rapidly across short distances.
UPDATE Issued at 616 PM CDT Sat Apr 27 2019
Minor adjustments were made this evening to precipitation forecast
tonight as scattered/numerous showers remain over central North
Dakota. Also increased winds west were 20mph gusting to 30 mph
winds were common ahead of the next wave.
&&
.SHORT TERM...(This evening through Sunday)
Issued at 258 PM CDT Sat Apr 27 2019
Highlights include an upgrade of the winter storm
watch to a winter storm warning for heavy snow Sunday
morning through Sunday night. A winter weather advisory
will be issued surrounding the winter storm warning.
For the rest of this afternoon, a weakening mid level s
shortwave trough across western ND is resulting in scattered
rain showers from south central through north central. Will
maintain scattered PoPs north to likely Pops far south central
this afternoon and into the early evening.
For tonight and Sunday, the latest water vapor imagery shows our
next strong mid/upper level low now circulating over southern Alberta.
This will slide southeast into western North Dakota 12z-18z Sunday,
then into eastern North Dakota by 12z/7AM Monday. Models similar
with the track of the 700mb low, from around Trotters to Washburn
and east into Carrington Sunday into Sunday night. Generally the
heaviest snow is just to the north of this track, and concur with
this idea given what the models are suggesting in terms of heavy
snow placement. Very strong ascent atop strong low level frontogenesis
and steep mid level lapse rates linking in between are advertised
to develop late tonight through Sunday for northwest and north
central ND. Areas of instability at times show up tonight northwest,
then south central Sunday afternoon. Have mentioned some thunder
in the grids, with some potential of thundersnow Sunday, although
the better instability per BUFKIT soundings resides across the
south Sunday. Across the far north,gusty east to northeasterly
winds of up to 40 mph at times will result in near zero visibilities
along with wet heavy snow. Precipitation will slowly wane from
west to east Sunday evening/night.
.LONG TERM...(Monday through Saturday)
Issued at 258 PM CDT Sat Apr 27 2019
As our storm system exits to our east, cooler air remains in place
over the Northern Plains on Monday. After morning lows in the 20s
and lower 30s, and lingering snow/rain showers that taper off by
noon, temperatures will reach only into the upper 30s to mid 40s,
with Monday night lows mainly in the 20s.
By Tuesday, the upper flow becomes southwesterly as yet another
storm system develops over the US Rockies. This system will bring
another round of rain and snow to Montana, Wyoming, the Dakotas and
Minnesota Tuesday and Wednesday. For western and central North
Dakota, look for a chance of rain or snow showers in southwest and
south central North Dakota Tuesday, but more widespread rain/snow
showers Wednesday.
This active pattern continues, with another system setting up for a
chance of rain and a possible snow mix for next weekend. The models
hint at a chance of thunder as well Friday night and Saturday.
A cool first half of next week, with highs mainly in the 40s...then
a modest warming trend towards the end of the week, with highs in
the 50s to lower 60s.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 616 PM CDT Sat Apr 27 2019
A strong low pressure system develops over the region tonight
bringing initially -RA to western ND this evening. Heavy snow and
strong easterly winds develop Sunday morning, continuing through
Sunday night across northern North Dakota. MVFR and IFR cigs and
vsbys return at KDIK and KISN after 06z. IFR conditions expand to
KMOT-KBIS after 10z with rain at KBIS and rain changing to snow
and increasing winds at KMOT. The greatest potential for
accumulating snow with reduced visibility and cigs at KISN/KMOT
Sunday.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory from 5 AM CDT /4 AM MDT/ Sunday to 7 AM
CDT /6 AM MDT/ Monday for NDZ012-013-017>019-021>023.
Winter Storm Warning from 5 AM Sunday to 7 AM CDT Monday for
NDZ001>005-009>011.
&&
$$
UPDATE...AJ
SHORT TERM...KS
LONG TERM...JV
AVIATION...AJ
Area Forecast Discussion...UPDATED
National Weather Service Gray ME
950 PM EDT Sat Apr 27 2019
.SYNOPSIS...
After a brief break in an active weather pattern tonight into
Sunday...the next low pressure system will move by to our south
Sunday Afternoon and will spread more precipitation across
southern areas Sunday afternoon and evening. High pressure will
build into the region Monday, followed by another area of low
pressure passing by to our South on Monday Night into Tuesday.
Canadian high pressure will attempt to build back into the
region Wednesday, followed by yet more low pressure late in the
week.
&&
.NEAR TERM /THROUGH SUNDAY/...
945 PM Update...
Showers have diminished across the area except for a few
stragglers. Drier air is working its way in from the west now as
the upper level low lifts towards northeastern Maine. Winds are
also dying down steadily. Made a few minor updates to the
forecast, but no major changes to the PoPs as we may still see
some showers over the mountains and foothills.
6 PM Update...
Low pressure continues to pass by overhead bringing some
scattered showers to the region. These should diminish with time
from the south but have kept the showers /including some snow
showers over the higher terrain/ over a larger extent
temporally and spatially overnight as models are not handling
this system well. Only expecting minor QPF amounts, with a
cooler night than last night.
Previous discussion...
High Impact Weather Potential:
*Minor river flooding continues on the Presumpscot...Saco...and
Suncook Rivers. We expect flooding to occur later on the
Kennebec.
Pattern: Early afternoon water vapor imagery reveals an impressive
shortwave directly overhead with a moisture plume east of this wave
reaching all the way south into the tropical Atlantic. Drier air is
slowly filtering into the region as this moisture plume peels east
of the region. Looking to the west we see another smaller shortwave
disturbance quickly marching east which suggests that our break in
active weather will be rather brief. For the near term forecast
period tonight the focus will be on gradually improving conditions
as the aforementioned wave overhead lifts north and east into the
Canadian maritimes with a very weak ridge of high pressure building
into the region between the departing low and the approaching one
from the west.
Through this evening: While radar echoes have expanded over northern
NH and western ME this afternoon...drying continues to arrive from
the south and expect the ongoing shower activity to gradually become
increasingly restricted to the mountains. Temperatures will likely
fall below 40F in the mountains towards 8pm...with 40s dominates
elsewhere.
Tonight: Cyclonic flow this evening slowly loses it/s grip over the
region tonight as low pressure continues to pull north and east of
the region with a weak and narrow mid level shortwave ridge axis
arriving overnight. Shower activity will be confined to the
mountains and likely take the form of snow overnight with some
accumulating snow certainly possible in the upslope areas of the
Whites. Elsewhere expect a very gradual clearing trend with
northwesterly winds likely remaining coupled through the night. Cold
advection will already have largely ended...but with a cooler
airmass overhead...expect lows in the 20s in the mountains...and 30s
elsewhere.
&&
.SHORT TERM /SUNDAY NIGHT/...
High Impact Weather Potential:
* While river flooding will come to an end...river and lake levels
will remain high in many areas with some lingering flood impacts.
* Some potential for wet snow in the hills of southern NH Sunday
afternoon and evening.
Pattern: Secondary shortwave quickly scoots east along the southern
flank of longwave trough axis centered over Ontario/Hudson Bay...but
weakens somewhat initially as it runs into downstream shortwave
ridging...and passes south of New England Sunday afternoon/Sunday
night. It then strengthens as another upstream shortwave arrives
from the northwest and reorients the flow aloft but this happens too
late for any impacts here as the wave pushes east of the New England
coast. Thus...the primary forecast concerns through the short term
forecast period include precipitation with this wave as it passes
south of the region with a focus on any potential for snow.
Sunday: There is a good model consensus on surface low pressure
moving east from a position over northern West Virginia around
daybreak...off the southern Jersey coast by early afternoon and then
south of New England towards evening. Warm-advection induced
precipitation will make a run at southern New Hampshire by late
morning with the potential for a 6-8 hour period of precipitation
over southern NH and southwestern Maine during the afternoon and
evening. While the surface low and it/s track is well agreed
upon...the northern extent of the precipitation shield is not with
the 27.12Z NAM showing a complete miss...with a bit of a southward
adjustment in the northern extent of precipitation seen in the GFS
as well. Looking at the 27.12Z HRRR and the 27.12Z HREF shows a
much further north extent /LEB-LEW and points south/. Given the
scenario /weakening surface wave south of New England/ do not have
the confidence to go higher than likely PoPs over far southern
areas with this package. Also have to watch precipitation type.
At this point...it looks like wet bulb zero heights will be
around 2.5kft during the event...which should keep most spots
plain rain. As precipitation arrives...could see some of the
highest hilltops /above 1.5kft/ see some wet snowflakes. High
temperatures will not make it higher than the lower 50s along
the coast with 40s in the mountains.
Sunday Night: Low pressure will pull east of the region overnight
with clearing skies and northwesterly winds. Arriving airmass is
rather dry with PWATs falling to -1 to -2 sigma /below 0.25"/ and
surface dewpoints reaching the teens over northern areas and the 20s
south of the mountains. The gradient gradually slackens overnight
which should allow some locations in deeper valleys to decouple.
Here...expect lows around 20...with 20s to around the freezing mark
elsewhere...which is about 5F below normal.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
A rather active weather pattern will continue through the long term
portion of the forecast. Early in the period (Monday) weak high
pressure will result in dry and somewhat cool conditions over
the region. Monday Night into Tuesday the first of three areas
of low pressure will move east from the Ohio Valley. This low
will be weak with most of its precipitation staying south of the
region although light precipitation is possible over southern
areas. The 12z GFS is furthest north with the precipitation
shield while the 12Z Canadian is in line with the 00z ECMWF
keeping the northern extent of the precipitation area further
south. If the precipitation shield reaches to the lakes region
or north then snow showers are possible over those areas. High
pressure will nose south from Canada late Tuesday Night into
Wednesday.
A second area of low pressure will move NE from the Southern
Plains later Wednesday into Thursday. The ECMWF dries most of
the precipitation out as it runs into the dry Canadian airmass
associated with high pressure over Southern Canada. The GFS and
the Canadian models bring precipitation to Central and Southern
areas with the GFS again having the furthest north progress of
the precipitation shield. Similar to the first system, if the
precipitation shield makes it far enough north precipitation
type could be snow over central and northern areas. Given the
size of the Canadian High of Southern Canada would expect the
precipitation to weaken some as it moves NE.
High pressure will briefly build in later Thursday before a
third area of low pressure will moves east from the Great Lakes
Region Friday and Friday Night. All models develop a secondary
area of low pressure east of Cape Cod. Currently the models move
the secondary low pretty fast and offshore thereby limiting the
extend to the precipitation over the region...a closer to the
coast or slower solution would result in more precipitation.
While mostly rain is expected with this the mountains may see
some snow mixed in.
&&
.AVIATION /01Z SUNDAY THROUGH THURSDAY/...
Short Term...
Summary: Low pressure pulling away from the region will bring
improving flying conditions through tonight. Quick on its heels is
another system that will pass south of New England on Sunday and
Sunday night bringing rain to southern NH and potentially southwest
ME.
Restrictions: Conditions improving as of 18Z with VFR expected
to dominate most of the period through Sunday night. Exceptions
to this will be at HIE with lingering rain /and potentially
snow/ showers tonight with MVFR CIGS. Also...improvement has not
yet reached RKD...with IFR conditions expected to improve to VFR
over the next few hours. There is some potential for a period of
MVFR CIGS Sunday afternoon at MHT and perhaps CON...but
confidence is not high in this yet.
Winds: Southwesterly winds 15G25kts will diminish to 5-10kts
tonight with 10kt westerly winds expected for the day on Sunday
before diminishing to less than 5kts Sunday night.
LLWS: No LLWS expected through Sunday night.
Long Term...
VFR conditions on Monday will transition to areas of IFR
Monday Night into Tuesday over southern areas as low pressure moves
south of the region. MVFR conditions likely Later Tuesday into
Wednesday. Another area of low pressure with return areas of IFR
conditions late Wednesday into Thursday.
&&
.MARINE...
Short Term...
Small crafts continue as of this afternoon with residual waves
and westerly winds necessitating them through tonight for the
outer waters. For the bays...winds and waves have dropped far
enough to drop them from the SCA. While a brief break in
headlines is possible for the outer waters on Sunday...
strengthening northwesterly winds behind departing low pressure
Sunday night will renew the need for additional SCAs.
Long Term...
Waves below SCA levels into Wednesday. SCA level waves
possible late Wednesday through the end of the week as areas of low
pressure approach the region. Winds expected to stay below SCA
levels.
&&
.HYDROLOGY...
River flood warnings continue on the Androscoggin, Presumpscot,
Saco, Suncook, and Kennebec Rivers with many other rivers near
bankfull. We`re transitioning from headwater to main stem
flooding this afternoon and evening. Have dropped the flood
watch with no additional flood warnings expected and only minor
amounts of additional rainfall. All flooding is in the minor
category with all rivers likely falling below flood stage by
late Sunday/Sunday night.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...None.
NH...None.
MARINE...Small Craft Advisory until 6 AM EDT Sunday for ANZ150>154.
&&
$$
NEAR TERM...Hanes
SHORT TERM...Arnott
LONG TERM...Lulofs
AREA FORECAST DISCUSSION
National Weather Service Jackson KY
946 PM EDT Sat Apr 27 2019
.UPDATE...
Issued at 946 PM EDT SAT APR 27 2019
Did a quick update to include slight chance of thunder with a few
isolated strikes showing up on lightning detection. This is
brought in by a small ribbon of MUCAPE and EL temperatures colder
that -20 C based off the SPC mesoanalysis page. This will be more
and more limited as this band of light showers progresses east and
more favorable conditions mentioned above decrease. Otherwise,
mostly minor changes made to incorporate the latest obs and
trends.
UPDATE Issued at 748 PM EDT SAT APR 27 2019
The late afternoon surface analysis shows a warm front long and
just north of northern Kentucky and an area of low Pressure in
Missouri and cold front stretching from there back into the Texas
Panhandle. The warm front has been the focus for showers this
afternoon and will continue into this evening. Did update POPs to
reflect the better coverage of showers seen generally along and
north of I-64. Then once you move south the more downslope flow
and consequently drier air/high cloud bases have capped this more
as sprinkles in most cases. That said, the HRRR has been having a
hard time maintaining awareness of better POPs and actually
leaned toward the HREF placement for updated POPs. Overall feel
the grids are in reasonable shape and also blended in the latest
obs to allow for better trends.
&&
.SHORT TERM...(This evening through Sunday night)
Issued at 451 PM EDT SAT APR 27 2019
The latest surface map features low pressure currently centered
across northeast Missouri. A warm front is branched east of the
low into the Ohio Valley, with a cold front aligned southwestward
into the southern Plains. Aloft, fairly flat flow reigns for most
east of the Rockies. An embedded short wave through is noted
across the Midwest, aiming towards the Great Lakes/Ohio Valley
regions. Light precipitation has broken out across the Ohio
Valley, with some locations closer to the Ohio River having
measured thus far.
The models are in good agreement through the short term, with the
Midwest low pressure system dampening as it travels east across
the Ohio Valley tonight. This will spread some light rain showers
at times across eastern Kentucky. A cold front will move through
at around dawn, with a few showers lingering through Sunday
morning across far southeastern Kentucky. High pressure will then
quickly build in across the Great Lakes/Ohio Valley, bringing
drier weather to the Commonwealth through Sunday night.
Temperatures will drop off into the low to mid 50s tonight, with
highs on Sunday similar to today, generally upper 60s to lower
70s. Lows Sunday night under mostly clear skies will be cooler.
Some of the more sheltered valleys will drop into the low to mid
40s, while broader valleys and ridgetops remain in the upper 40s
to lower 50s.
.LONG TERM...(Monday through Saturday)
Issued at 410 PM EDT SAT APR 27 2019
A warm front will lift north through northeast Kentucky during the
day Monday, becoming a stationary frontal boundary north of the Ohio
River through the day Tuesday. A low pressure system will then ride
NE into the mid-Mississippi Valley and push the frontal boundary
farther northward, before dragging a cold front eastward into
Kentucky. This cold front is expected to sweep across the state
Thursday into Thursday night, exiting eastern Kentucky Friday
morning. High pressure and northerly flow will then follow behind
the passage of the cold front for the remainder of Friday,
continuing into Saturday as well.
Some passing showers and maybe a rumble of thunder will be possible
in the northern portion of the CWA Monday as the warm front pushes
north. After that generally dry weather should be on tap through mid-
week, with most of the precip remaining along the stationary front
located to our north. SW flow in place across eastern KY will boost
temperatures into the mid and upper 80s for most locations on
Tuesday and Wednesday (slightly cooler in the low to mid 30s on
Monday afternoon). As the cold front nears the CWA Wednesday, clouds
will be on the increase.
By Thursday, scattered pops will begin to overspread the region.
Coverage will continue to increase heading into Thursday night as
the front begins to pass over, with high pops remaining place
through Friday morning before tapering off throughout the afternoon
as drier air begins to filter in. Some instability will be present
ahead of the frontal passage on Thursday and Thursday night, so did
include thunder chances. However, most of this instability is lost
by Friday morning once the front has moved over, so thunder
potential will be more limited or not likely. Highs on Thursday will
be in the upper 70s to low 80s with the cloud cover and rain.
However, post frontal temperatures will be much colder as northerly
winds take hold. Highs on Friday may barely top 70 degrees in some
locations. A similar story will be had for Saturday as well as the
northerly flow continues.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
ISSUED AT 739 PM EDT SAT APR 27 2019
A warm front is now around northern Kentucky and nearer the Ohio
River, and an low pressure and attendant cold front are located
to our west around Missouri. We have some more scattered rain
shower activity along and just south of the warm front that has
brought some light showers to SYM, but the dry air is keeping
other areas capped to mostly sprinkles under high clouds bases.
Overall this will allow for VFR CIGs and VIS through much of the
night outside any temporary drops in VIS to maybe MVFR at SYM at
worst.
The low pressure and cold front will push east tonight and move
across the region early Sunday. While this system does become more
anemic in terms of moisture, we could see some showers along and
near this feature. This system will also bring some post frontal
low clouds with it and therefore kept the mention of MVFR toward
dawn Sunday. However, the LAMP and HREF probabilities of IFR
seemed lower overall and leaned away from that for now. The lower
clouds will decrease through the day Sunday and lead to a return
to VFR by Sunday afternoon.
The winds will increase out of the southwest tonight at 5 to 10
knots with some gusts of 15 to 20 knots not out of the question.
The winds will veer back around to the northwest and north as the
front passes through Sunday morning.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...DJ
SHORT TERM...GEOGERIAN
LONG TERM...JMW
AVIATION...DJ
Area Forecast Discussion...Updated
National Weather Service Saint Louis MO
943 PM CDT Sat Apr 27 2019
.UPDATE...
Issued at 923 PM CDT Sat Apr 27 2019
Isolated showers have moved out of the far eastern part of the
CWA ahead of the cold front. Northwest winds have occasionally
gusted up to 40 mph this evening behind the front, and these winds
will begin to slowly decrease during the late evening and
overnight hours as surface low over central Illinois moves off to
the east. Low clouds are progressing southeastward across the area
behind the front, and expect most of the area to remain mostly
cloudy through the night. Satellite trends and forecast soundings
still suggest that there will be some clearing across northeast
Missouri and west central Illinois late tonight. This coupled with
winds decreasing below 10 mph will be enough for some areas of
frost as temperatures fall to near freezing over the northern CWA.
Do not plan on issuing a frost advisory as extent of frost is
questionable given how quickly the clouds will be clearing out and
how quickly the winds will be decreasing late tonight.
Britt
&&
.SHORT TERM... (Through Late Sunday Afternoon)
Issued at 403 PM CDT Sat Apr 27 2019
Low pressure near Kirksville is dragging a cold front through
western Missouri. Strong southwest wind ahead of the front has
pushed temperatures well into the 70s along and west of the
Mississippi River this afternoon so far, and nearly 80 in central
Missouri where much of the morning cloudiness has dissipated. The
surface low is forecast to move rapidly east into the Ohio Valley
this evening which will push the cold front through through
southeast Missouri and southern Illinois by Midnight tonight.
Winds behind the front will turn sharply to the northwest and
current indications are that the wind will be just as strong
behind the front tonight as it was today ahead of it with gusts in
excess of 35 mph in some spots. Blended MOS guidance did not seem
to do justice to the strong cold advection behind the front, so I
used a blend of RAP and GFS 1hr 2m temperature grids to show the
downward spiral tonight. Most of the forecast area should stay
above freezing in the mid to upper 30s, but it looks like parts of
northeast Missouri and west central Illinois will just kiss 31-32
degrees for a short period Sunday morning. Unsure of frost
potential due to cold advection clouds behind the front and the
probability that wind will interrupt frost deposition, but can`t
rule out some patchy frost before sunrise Sunday morning.
Lingering stratus/strato-cu should dissipate before noon. However,
the morning cloudiness will dampen the warm up somewhat. With the
morning starting out primarily in the 30s, afternoon highs will
barely break 60 in most locations...and probably won`t get out of
the upper 50s in northeast Missouri and west central Illinois.
This is about 10 degrees below normal for late April.
Carney
.LONG TERM... (Sunday Night through Next Saturday)
Issued at 403 PM CDT Sat Apr 27 2019
Next week continues to look wet, with several rounds of potentially
heavy rain. The GFS and ECMWF both have the first wave developing
Sunday night and affecting primarily areas north of I-70 in central
and northeast Missouri and west central Illinois. A 40+ knot low
level jet and strong moisture convergence at 850mb make the model
output QPF of an inch or more very believable. The convection tries
to push the effective low level baroclinic zone further south into
central and east central Missouri on Monday, but persistent
southwest flow will continue to try to push the baroclinic zone back
closer to Iowa. Of course, the southwest flow across the
baroclinicity will also provide lift to continue to produce
precipitation. This process continues Monday night, through at
least Wednesday night and into Thursday. Both the GFS and ECMWF
primarily target northeast Missouri and west central Illinois for
the heaviest rain through the period. WPC total QPF through the end
of the week exceeds 3 inches in those areas...and given what the EC
and GFS are showing this looks reasonable.
Both the GFS and EC break the wet pattern with a broad upper level
wave moving through the Upper Midwest on Thursday afternoon/evening.
This should finally push a weak cold front through the mid
Mississippi Valley and bring us dry weather for Friday and Saturday.
Carney
&&
.AVIATION... (For the 00z TAFs through 00z Sunday Evening)
Issued at 615 PM CDT Sat Apr 27 2019
A cold front is moving across the area and causing winds to shift
out of the northwest at all of the terminal, with gusts expected
around 30KT tonight. These gusts will begin to diminish between
06-12Z. Low clouds will move in behind the cold front, with low
MVFR ceilings or possible IFR ceilings tonight. These clouds are
expected to clear out of the terminals on Sunday morning allowing
for dry and VFR conditions for most of the day on Sunday.
SPECIFICS FOR KSTL:
A cold front is moving through the terminal and causing winds to
shift out of the northwest, with gusts expected around 30KT
tonight. These gusts will begin to diminish toward 12Z. Low clouds
will move in behind the cold front, with low MVFR ceilings or
possible IFR ceilings tonight into Sunday morning. These clouds
are expected to clear out of the terminal late on Sunday morning
allowing for dry and VFR conditions for Sunday afternoon and
evening.
Britt
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...None.
IL...None.
&&
$$
WFO LSX
Area Forecast Discussion...UPDATED
National Weather Service Shreveport LA
958 PM CDT Sat Apr 27 2019
.UPDATE...
Strong convection is ongoing west of the DFW Metroplex. The HRRR
appears to be the only model that is accounting for this activity,
and it suggests the storms should dissipate shortly after
midnight. Latest mesoanalysis and regional 00z soundings suggest
the convection will encounter a more stable environment and
increasing convective inhibition as they approach the Metroplex
and locations farther east. In addition, latest radar loops show a
slight downward trend in overall thunderstorm activity. Thus, it
appears the HRRR seems to have a decent handle on the situation.
No additional showers or thunderstorms have developed along the
cold front across Southern and Southeast Oklahoma. Some light
radar returns have been present most of the evening north of the
Interstate 30 corridor. This is associated with a band of mid-
level moisture across the region. So far, none of this
precipitation has reached the ground, but an isolated observation
or two of light rain can`t be ruled out through the night.
PoPs were lowered into the slight chance category and were
generally confined to areas along and north of US Highway 82 in
Southeast Oklahoma, Southwest Arkansas, and extreme Northeast
Texas. The remainder of the grids were left largely intact.
CN
&&
.PREV DISCUSSION... /issued 657 PM CDT Sat Apr 27 2019/
UPDATE...
See below for 28/00z Aviation Discussion.
Gusty winds still persist in a few locations, but overall, wind
speeds have begun to diminish. Therefore, the Lake Wind Advisory
was allowed to expire.
CN
AVIATION...
For the 28/00z TAFs, VFR conditions should prevail at most
terminals until the early morning hours. Scattered convection may
develop throughout the period along a cold front, mainly affecting
Southeast Oklahoma, Southwest Arkansas, and extreme Northeast
Texas. This includes KTXK and KELD. However, confidence is not
particularly high regarding the timing or overall convective
coverage. Therefore, convection was not mentioned in the TAFs, but
amendments will be made if conditions change. Otherwise, low-level
southerly flow should result in low clouds and MVFR ceilings in
most locations for a few hours around sunrise Sunday morning, but
VFR flight conditions should return by late morning or early
afternoon.
CN
PREV DISCUSSION... /issued 405 PM CDT Sat Apr 27 2019/
SHORT TERM.../Tonight through Sunday Night/
A weak trough and associated cold front will continued to be
pushed southward toward the region by a short wave digging across
upper midwest. This boundary will stall near the I-30 corridor
this evening and will become the focus for widely scattered
convection mainly north of I-30 and possibly down to Interstate 20
tonight through early Sunday. With steep mid level lapse rates
and cool temperatures aloft, some large hail and isolated damaging
winds will be possible. Dry conditions should return on Sunday
across most of the region, although some leftover boundaries may
remain across areas north of I-30. With an unstable airmass in
place, some isolated diurnal convection could be possible. Highs
on Sunday expected to reach near 80 degrees with lows near 60.
/20/
LONG TERM.../Monday through Saturday/
A very unsettled pattern will define the long-term forecast with a
slow-moving frontal boundary across the Plains on Monday approaching
our region. The boundary is progged to stall out just to our NW and
linger through mid week as weak forcing begins encroaching on much
of our region. Additional lift will come with upper level impulses
transitioning through the increasing SW flow aloft, result in higher
rain chances by Tuesday and especially into Wednesday and Thursday.
This will occur as a strong shortwave pivots eastward out of the
Rockies and helps to nudge the front southward into our region late
Wednesday through Thursday. This is the general timeframe for the
possibility of a few strong to severe storms in addition to heavy
rainfall, especially along and north of the I-30 corridor. For now,
the concern is slightly higher for the threat of heavy rain
followed by possible flooding as rainfall amounts could exceed 4-5
inches in some areas across our NW through the end of the week.
The front is expected to eventually clear the region over the
weekend, but low rain chances could linger through at least Saturday
depending on how quickly the front shifts southward. Temperatures
will generally run near to slightly above average through much of
the period with highs mainly in the upper 70s to lower 80s and lows
mainly in the 60s.
/19/
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 62 83 60 83 / 0 10 10 10
MLU 62 80 59 84 / 0 10 10 10
DEQ 62 78 59 79 / 20 20 10 10
TXK 62 80 59 79 / 20 20 10 10
ELD 61 79 59 82 / 10 20 10 10
TYR 64 82 62 80 / 10 0 10 10
GGG 63 82 61 81 / 10 0 10 10
LFK 62 83 62 82 / 0 0 10 10
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...None.
LA...None.
OK...None.
TX...None.
&&
$$
09/15