Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 05/06/19
Area Forecast Discussion
National Weather Service Bismarck ND
933 PM CDT Sun May 5 2019
.UPDATE...
Issued at 929 PM CDT Sun May 5 2019
Precipitation has finally moved out of the southwest, with light
rain continuing in south-central North Dakota. Expect this area of
precipitation to move out of the forecast area within the next
couple of hours, before the far southwest counties again have a
chance of snow beginning in the early morning. Patchy fog is
possible mainly in southwest North Dakota overnight per RAP
sounding analysis. Expect low temperatures tonight in the upper
20s to low 30s, with the colder temperatures in the north due to
slightly less cloud cover.
UPDATE Issued at 626 PM CDT Sun May 5 2019
Snow is continuing to fall in southwest North Dakota, with surface
observations showing temperatures only in the mid 30s. Had to
adjust grids to reflect a better chance of snow or at least a
rain/snow mix since precipitation is not transitioning to rain as
expected, even earlier this afternoon when surface temperatures
were in the upper 30s. Just now starting to get some light rain
here in Bismarck. A thick cloud deck continues to move east
through most of the forecast area, although the northwest corner
is seeing some sunshine. Precipitation is expected to diminish
within the next few hours.
&&
.SHORT TERM...(This evening through Monday)
Issued at 220 PM CDT Sun May 5 2019
Latest radar and satellite continues to indicate cloudy skies over
areas south and west of Lake Sakakawea and the Missouri River, and
rain and snow over southeast Montana into west central North
Dakota and parts of the southwest and far south central. The rain
and snow is making for a rather damp and dreary day over the
southwest with highs in the mid 30s to lower 40s. Elsewhere,
although rather cool, generally light winds and at least partial
sunshine is making for a cool but pleasant afternoon.
Scattered rain and snow showers will continue into the evening
hours over the southwest and far south central, with any
accumulating precip pretty much ended by midnight. Another impulse
within the broad upper trough currently situated over the
northern U.S. will bring some small precipitation chances to the
far southwest and south central again on Monday.
Lows tonight are expected to be in the mid 20s to mid 30s with
Highs Monday in the upper 40s to mid 50s. SuperBlend has been
doing quite well with temperatures as of late, especially MinT. We
used this for the minimum temps tonight and a blend of SuperBlend
and slightly warmer Mos guidance for Monday.
.LONG TERM...(Monday night through Sunday)
Issued at 220 PM CDT Sun May 5 2019
Cool temperatures will be the main forecast issue in the long term
period. A persistent eastern Pacific ridge and broad upper trough
will continue through much of the work week. As upper level
impulsed traverse the broad trough, expect mainly isolated shower
activity each day. The ridge/trough pattern advances slowly east
through the week, resulting in a slow warming trend from the upper
40s and 50s Monday and Tuesday, to the mid 50s to lower 60s on
Friday.
There is some indication of a slightly stronger shortwave moving
through the northern plains on Friday-Saturday but there is not
much model consensus among the deterministic models. The Global
GEM is colder and wetter with a closed upper low over the state
by Saturday morning and lingering over the area through Sunday
morning. The ECMWF is stronger with the western ridging and
shunts the shortwave farther east, and is mainly dry and warmer
through the weekend. The GFS is somewhat colder and wetter than
the ECMWF with a closed low over Minnesota by 18Z Saturday, but
certainly not as cool and wet as the Global GEM. The GFSEnsemble
supports more of a GFS or ECMWF solution. Will stick with the
model blend for now but will continue to monitor through the week.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 626 PM CDT Sun May 5 2019
Light snow is continuing to fall in southwest North Dakota,
causing KDIK to drop to IFR conditions. This precipitation is
expected to taper off within the next few hours. Otherwise, VFR
conditions are expected for the 00Z TAF cycle, with a low-level
cloud deck moving through and a chance of precipitation in far
southern North Dakota. Winds are currently 10-15 knots from the
northwest, becoming light overnight and then only increasing to
5-10 knots tomorrow during the day.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...MJ
SHORT TERM...TWH
LONG TERM...TWH
AVIATION...MJ
Area Forecast Discussion
National Weather Service Dodge City KS
741 PM CDT Sun May 5 2019
.UPDATE...
Issued at 740 PM CDT Sun May 5 2019
Much, much busier day than was planned. As of this writing, a
tornadic supercell continues in northern Meade county. Other than
the tornado/large hail threat, this slow -moving storm is
producing a serious flash flooding threat, with radar estimates now
passing 10 inches and still raining. Another supercell approaching
from the northwest will interact with this established supercell
over the next hour. The environment downstream from the Meade county
supercell looks favorable for supporting further tornadic potential,
as the low level jet increases. CAMs including the HRRR are
underperforming today, so will rely on radar trends.
Also, radar indicates a strong tornado passing through NE Stafford
county as of 740 pm. Drier more stable air has arrived roughly
north of US 50 as of 7:40 pm, where the severe thunderstorm watch
was cancelled early. Severe threat will continue for several more
hours in the counties adjacent to Oklahoma.
&&
.SHORT TERM...(This evening through Monday)
Issued at 103 PM CDT Sun May 5 2019
The focus for thunderstorm chances shift slighty east across
southwest Kansas and into portions of central Kansas this evening
ahead of a slowly deepening surface low in extreme southwest Kansas.
A prevailing southerly flow will further enhance moisture advection
into central Kansas as a sharpening dryline attendant to the surface
low remains situated across southwest Kansas. Steepening low/mid
level lapse rates ahead of the dryline and more than sufficient
instability will set the stage for thunderstorm development later
this afternoon as a series of H5 vort maxima eject out of the
Colorado Rockies into the high plains. SBCAPE values upward of 2500
to 3000 J/kg, favorable 0-3km shear at 30kt, and a modest +60kt
westerly flow aloft will increase severe potential with large hail
and damaging winds the main threat. An isolated tornado cannot be
ruled out.
As for temperatures, look for lows back down into the 50s(F) tonight.
For Monday, highs will be dependent on how far south a cold front
pushes southward into western/central Kansas before stalling out.
Highs are expected to be in the mid/upper 60s(F) to possibly near 70F
behind the boundary in central Kansas Monday afternoon with the
lower/mid 80s(F) more likely closer to the Oklahoma border.
.LONG TERM...(Monday night through Sunday)
Issued at 230 PM CDT Sun May 5 2019
Regardless of weak ridging aloft moving out of the Southern Rockies
into the Western High Plains Monday, thunderstorms will be possible
Monday evening in vicinity of a cold front projected to push
southward through much of western and central Kansas late in the
day. Although upper level westerlies will be relativly weak,
abundant moisture/instability and sufficient forcing associated with
the frontal boundary should be enough to trigger thunderstorm
development across portions of southwest and central Kansas toward
the evening hours. Thunderstorm chances continue each day through at
least Wednesday due to little movment of the aforementioned frontal
boundary while an upper level trough pushes ashore into the Desert
Southwest Tuesday, setting up an increasingly difluent southwest
flow aloft across the Western High Plains.
Near to a little below normal temperatures are likely dependent on
the orientation of a near stationary frontal boundary draped across
the area Tuesday. Should see highs generally up into the 60s(F)
and the lower/mid 70s(F). Cooler air begins to spread into western
Kansas behind a strong cold frontal passage late Wednesday. Could
see a wide range of temperatures Wednesday with highs possibly
only up into the 50s(F) toward west central Kansas to the 70s(F)
further southeast...all dependent on timing of the front.
Significantly cooler air spilling into the area may limit highs
to the 50s(F) Thursday.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 600 PM CDT Sun May 5 2019
Scattered thunderstorms will track slowly east-southeast across
southwest Kansas into central Kansas through late this evening,
potentially affecting all terminal sites with gusty outflow winds
and large hail. Otherwise, predominately VFR conditions can be
expected through late this evening. Low level stratus is then
expected to develop along and behind a cold front as it pushes
southward across western and central Kansas overnight. MVFR cigs
will be possible at KHYS initially generally after 09Z and
potentially IFR cigs toward daybreak. MVFR cigs may reach as far
south/southwest as KGCK and KDDC. Besides possible gusty outflow
winds from vicinity thunderstorms, southerly winds generally 10 to
30kt will persist across central and portions of southwest Kansas
through late this evening as a surface low remains anchored
across extreme southwest Kansas. Southerly winds are expected to
subside overnight with the loss of daytime heating.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 55 76 54 71 / 70 40 50 50
GCK 53 71 51 68 / 30 40 50 50
EHA 52 82 53 75 / 10 20 30 30
LBL 55 82 55 74 / 40 30 40 40
HYS 55 65 49 61 / 60 50 70 60
P28 57 80 57 73 / 40 50 50 40
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Turner
SHORT TERM...JJohnson
LONG TERM...JJohnson
AVIATION...JJohnson
Area Forecast Discussion
National Weather Service Pocatello ID
142 PM MDT Sun May 5 2019
.SHORT TERM...Tonight through Tuesday night.
A weak disturbance will move through the region this afternoon. This
will help to fuel a few isolated thunderstorms into the evening. On
Monday, a low pressure system over southern California will send a
bit more moisture into our region as a weak low pressure system
gradually develops across southern Idaho. We`ll see shower and
thunderstorm coverage pick up on Monday and more noticeably on
Tuesday as the low moves through eastern Idaho. Best chances for
storms will be during the afternoon and evening hours, while showers
may persist through the night Monday night into Tuesday morning.
Temperatures will remain mild on Monday but cooler Tuesday with more
clouds and showers around.
Valle
.LONG TERM...Wednesday Through Next Sunday.
By Wed, longwave troughing will be starting to shift east with the
main axis of the trough already east of our forecast area, but this
feature will still be in close enough proximity for moisture and
disturbances riding down the west side of it to spread showers/t-
storms into the region. Both days, this activity will focus on the
eastern/southern highlands largely south and east of the interstate
corridors, with drier conditions for everyone else. Temps both days
will remain cool and precip amounts generally light, so no major
triggers for hydrologic issues are foreseen. A strengthening ridge
of high pressure will build in from the west for Fri and the weekend
with increasing confidence in dry wx and progressively warming
temps, possibly reaching the upper 70s in the Snake Plain/eastern
Magic Valley by Sun. No high-impact wx is foreseen for this
period.
&&
.AVIATION...In many ways, today will seem very much like
yesterday for aviation interests. Forecast confidence is again
high in VFR if not unlimited cigs/vsbys at all terminals through
early Mon afternoon. We have yet another weak disturbance
approaching the region, and while we will again face limited lift
and moisture, high-res HREF ensemble members and HRRR are again
developing a few showers/t-storms late this afternoon/eve near
KIDA and KDIJ, with perhaps just slightly better confidence and
coverage than yesterday supported by higher atmospheric
instability. Now, the high-res guidance and NAM time- heights are
not strongly indicating a cell will move directly over either
terminal, so we do not have confidence to push beyond VCTS at this
time, but even if a cell did make a direct assault, low-level dry
air makes it unlikely we would see cigs/vsbys less than VFR, even
briefly. Some gusty/erratic winds would be possible. Otherwise,
diurnally-time winds will again increase at all terminals to
values that may be marginally of interest to some GA aircraft, but
trajectories should again align well enough with our runway
configurations to preclude crosswinds. Winds managed to stay
westerly at KSUN yesterday afternoon instead of following the
usual diurnal shift into the SE, and a similar evolution is
supported today by RAP/NAM/HRRR plan-view model projections, so
some crosswinds will be present here at up to 10kts. Beautiful
aviation wx again expected overnight with lighter winds and no
concerns. - KSmith/Valle
&&
.HYDROLOGY...Most streams and rivers are within their banks across
the region. We will see warming temperatures into the first half of
the week. We could start seeing bankful conditions once again on a
few rivers within the next few days especially the Big Wood at
Hailey.
Valle
&&
.PIH WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
Area Forecast Discussion
National Weather Service Pueblo CO
348 PM MDT Sun May 5 2019
.SHORT TERM...(This evening through Monday)
Issued at 348 PM MDT Sun May 5 2019
...Potential for Severe Thunderstorms increases for Monday but
details still murky...
Still under mid and high based moisture across southern CO, beneath
westerly flow aloft between the southern stream closed low moving
into southern CA and a broad trough moving through the northern U.S.
Rockies into the northern plains. Dry line has kicked eastward and
resides just east and south of the CWA though nicks very close to
the southeast corner of Baca county. Have seen some healthy
convection firing along/east of this boundary just over the KS and
OK border...but dew points in the 20s and teens across southern CO
has kept convection of the high based variety. Model soundings show
some very high based CAPE today with a couple hundred J/kg at most.
Main concern will be the potential for localized gusty winds around
50-60 mph given steep lapse rates and healthy amounts of downdraft
CAPE...particularly across the eastern 2/3rd of the area. Various
iterations of the HRRR have picked up on this potential in wind
gusts fields, though notion that locations will be correct is a bit
far fetched. Potential exists just about anywhere across the lower
elevations through early evening though threat will be highly
localized. Convection should simmer down with loss of heating this
evening. Warming aloft and westerly drainage winds overnight will
keep lows on the mild side of guidance.
Upper low moves into southern CA on Monday which shifts flow more
southwesterly aloft across the southern Rockies which will eject
another weak shortwave across the area Monday afternoon. Meanwhile,
models differ significantly in timing and position of a cold front
which moves into southeast CO Monday morning and stalls. GFS stalls
the front along a line from roughly KSPD...to KPUB to KCOS line by
21z Mon...with dew points along/north of the front creeping up into
the low 50s along the CO/KS border to the 30s along the I-25
corridor. NAM is a little stronger in its southward push, stalling
it along the northern slopes of the Raton Mesa with dew points in
the mid 50s across Baca county to the upper 30s/around 40 across
Pueblo and El Paso county. CAPE values along/behind the front are
highest in the NAM12 putting highest values 2000+ J/kg across Baca
county and portions of the southeast plains though soundings show a
stout cap north of the front. The I-25 corridor sees CAPEs of 1000
J/kg across Pueblo and El Paso counties if NAM is correct. Of
course, GFS is lower, and ECMWF leans towards the GFS solution. But
this still doesn`t lend much confidence given their lower
resolutions. High res ensemble members lean more towards the NAM
solution with strong to severe convection breaking out along the
northern slopes of the Raton Mesa region around 20z and spreading
eastward across the southern portions of the southeast plains
through 00z. Deep layer shears will be running 40-50 kts across
southern CO supportive of supercell thunderstorms producing large
hail and damaging winds. Palmer Divide will also be a place to
watch...though its quite possible KCOS and KPUB could get spared as
there may not be sufficient time to draw the deeper higher dew point
airmass all the way westward...but suspect some strong wind gusts
and at least some small hail will be possible. Hard to argue with
SPC Day2 Outlook for now with broad marginal risk across southern
CO. Suspect some areas may upgrade to slight depending on timing and
strength of westward advection of higher dew points...but too
uncertain now to tell. Of course, where sfc winds back more
easterly will provide the greatest SRH (200-300 m2/s2) and potential
for supercells with an isolated tornado risk. Two areas to watch
for this will be Palmer Divide and northern slopes of the Raton
Ridge. there are enough parameters in place to put mention of severe
in the grids.
Just to add to the challenge, temperatures in model guidance differ
by 15 degrees across the southeast plains depending on location of
the front. Playing the safe middle of the road answer for now but
probably not warm enough on the warm side, nor cool enough on the
cool side. Will hope for some more solid answers with next set of
model runs.
Farther west...still some mid/high based moisture for high based
convection with lightning and gusty wind potential the greatest
threats. Mountain areas will see breezy southwest winds mix down
during the afternoon and temperatures warming into the 40s and 50s
across the high country. This will likely enhance snow melt and
cause further rises along the rivers and creeks before temperatures
start to cool off towards mid week. -KT
.LONG TERM...(Monday night through Sunday)
Issued at 348 PM MDT Sun May 5 2019
...A Cool and Unsettled Weather...
Monday night-Tuesday...Uncertainty in location of frontal boundary
and the amount of instability across the southeast Plains continues
into the Monday night and Tuesday forecast period, as the NAM
continues to indicate the front further west and indicating a much
more stable atmosphere in place than the GFS and EC, which have the
front further east leading to better chances of severe weather
across the plains into Monday evening. SPC still is indicating a
marginal risk of severe storms across most of the Plains and a
slight risk across southeastern portions of Baca County, and will
need to continue to monitor later model runs to try and pin point
the best potential and location for severe weather tomorrow. At any
rate, have stayed with a blended model solution, which keeps
scattered showers in place across the eastern mountains and plains
through the overnight hours with developing waa within increasing
southwest flow aloft across the region. Cloudy conditions in place
across the eastern half of the forecast area early Tuesday with
scattered showers and thunderstorms expected to develop across the
area in the afternoon, as uvv increases ahead of a weakening upper
low translating across the Desert Southwest and Great Basin. Some
models try to lift the front north and east again across the far
southeast plains, with the SPC Day3 Outlook indicating a marginal
risk for severe storms across Baca County, though location of the
boundary remains in question.
Tuesday night-Thursday...Models continue to differ on the details
though continue to indicate that the weakening Desert Southwest
upper low merges with another deep upper trough digging across the
Intermountain West and into the Great Basin on Tuesday. The merged
system lifts out across the Central and Southern Rockies Tuesday
night through Wednesday night, as more energy digs down the backside
of the system into the Great Basin on Thursday. Although it is hard
to pin down the exact timing and location, this pattern supports a
much cooler and more unsettled weather pattern, with scattered to
numerous rain and snow showers spreading across the area in the
Tuesday night through Thursday timeframe. Snow accumulations of
several inches looks to be in the offing across the higher terrain,
with snow levels lowering to between 6000-7000 ft Wednesday night
and early Thursday morning. With that said, there may be some winter
weather highlights in the offing for this time frame, generally
above 10,000 ft, and would not be surprised to see some light
accumulations on grassy areas along the Palmer Divide and Raton Mesa
Wednesday night and Thursday morning. Wednesday and Thursday look to
be the coldest days of the week with highs in the 40s and 50s across
the Plains and mainly 30s and 40s across the higher terrain. We also
may need to issue freeze products through out this timeframe, with
subfreezing temperatures possible across portions of the plains.
Friday-Sunday...Models continue to indicate a warming trend back to
near seasonal levels into the weekend, as secondary energy digging
across the Great Basin continues into the Desert Southwest into
Friday and then slowly lifts out across the Southern Rockies through
Sunday. This pattern would keep the best chances of daily showers
and storms over and near the higher terrain through the period.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 348 PM MDT Sun May 5 2019
VFR conditions expected at the TAF sites with the potential for
localized gusty winds up to 40 kts with any high based VCSH/VCTS.
Threat will be greatest before 01z. Clouds should decrease this
evening, with a wind shift from the north at KCOS and KPUB between
12z-15z as a cold front moves through. Current set of simulations
do not look terribly strong with the winds behind the front but
wouldn`t be surprised to see some gusts to around 25 kts at either
or both terminals during the morning. Winds will shift around from
the east at KCOS and KPUB during the afternoon around 15 kts with a
better chance for thunderstorms.
KALS will see a return of gusty southwest winds on Monday with gusts
to around 25 kts. High based showers could result in local gusts to
around 40 kts again during the afternoon. -KT
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...KT
LONG TERM...MW
AVIATION...KT
Area Forecast Discussion
National Weather Service Springfield MO
636 PM CDT Sun May 5 2019
.SHORT TERM...(This evening through Monday Night)
Issued at 308PM CDT Sun May 5 2019
Main concern is potential for heavy rain/flooding and the severe
storms risks for late Monday/Monday night.
Quiet right now. High pressure over the region attm will shift
east. A weak shortwave over eastern KS/OK had some light showers
associated with it earlier, but only some remnant clouds and
sprinkles are left.
Another subtle wave over western KS will move into our western
counties overnight with additional chances for precip. Should be
elevated convection with modest instability. HRRR is the most
bullish, but high resolution cam`s all vary on placement and to
some extent timing. Pockets of heavier rain possible but not
planning on any flood watches for tonight but wouldn`t rule out a
hydro warning or two.
There are more concerns for Monday night as a sfc front drops
south extending from south central/southeast KS into central MO by
late in the day. Moderate instability develops along and south of
the boundary by late in the day, especially over the western half
to two thirds of the cwfa with progged mlcapes of 1500-2500 j/kg.
Convection looks to increase along the frontal zone after 21z and
initially could see a mix of multicell and supercell structures
before the instability gradually weakens during the evening hours.
Wind/hail risk will be the main concern over out northwest
counties.
With precipitable water/pwat values progged to reach at or above
the 90th percentile for this time of year as moisture continues
to pool near the frontal boundary, a heavy mesoscale rainfall
event looks increasingly likely somewhere over or nearby our
cwfa. In broad terms our northern cwfa looks to be more favored
for heavy rain at this point, closer to the front, where there
will be the potential for training storms. No headlines yet but
next shifts will have to try to be more precise with the risk
area for Monday night.
.LONG TERM...(Tuesday through Sunday)
Issued at 308 PM CDT Sun May 5 2019
Active weather is expected through Wednesday night with a quiet
and cool period late in the week.
Tuesday-Wednesday: A west-east oriented sfc front is expected to
extend from southeast KS into southern MO by Tuesday morning then
slowly lift north again as a shortwave moves ene out of the
central and southern Rockies and the associated sfc wave develops
over the High Plains. For Tuesday, expect showers-tstms to be
focused closer to the low level convergence along and just north
of the frontal boundary (wherever it sets up). Ripples/shortwaves
in the overall modest ridging aloft are hard to pinpoint this far
out. Overall instability looks more modest Tuesday so the main
focus will be the additional rainfall.
The sfc wave/low is expected to reach eastern KS/west central MO
by late evening as the shortwave swing northeast. By this time the
entire cwfa will be in the warm sector ahead of the advancing sfc
low and cold front. The GFS actually shows some modest capping in
the southwest flow aloft with heavier rains north of the warm
front, but eventually believe some strong to severe storms will be
possible either over the northern cwfa closer to the warm front,
and/or with the cold frontal passage as the low shift northeast
through MO. A look at vertical thermo profiles off the GFS would
indicate more of wind/hail threat but shear could support a
tornado threat embedded within a line of storms with the cold
fropa or over central MO closer to the warm front.
Added rainfall will also be a concern during this time and will
take it one day at a time as far as the setup for heavier rain
potential. Hard to pinpoint any particular areas and the modest
capping in the warm sector may limit amounts to an extent.
Thursday-Sunday: Quiet. High pressure and cool weather is expected
in the wake of the exiting low.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 616 PM CDT Sun May 5 2019
Area still remains under the influence of high pressure with
mostly clear skies and generally light winds. An upper level wave
moved through during the day producing some mid and upper level
clouds over central and southcentral Missouri. Another wave over
western Kansas should begin to approach the area after 06z and
could begin producing showers in the KJLN terminal area after 06z
and in the KSGF/KBBG areas after 12z.
A surface front...which currently extends from northeast Iowa into
south-central Nebraska will move into central Missouri by the end
of the forecast period. Expect coverage of showers to increase
through the morning hours with thunderstorms possible after 18z.
&&
.SGF WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&
$$
SHORT TERM...DSA
LONG TERM...DSA
AVIATION...Gaede
Area Forecast Discussion
National Weather Service Shreveport LA
925 PM CDT Sun May 5 2019
.UPDATE...
West TX/OK convection diminish overnight as they encounter much
drier air eastward, as seen on both FWD and SHV 0Z soundings.
Overnight lows either side of 60 degtrees expected as temps manage
to fall fairly close to dewpoints. Holding off on adding any
mention for significant fog although some patchy fog is possible
in wet ground and radiation cooling prior to cirrus canopy
arriving from the west later tonight./07/.
&&
.PREV DISCUSSION... /issued 600 PM CDT Sun May 5 2019/
AVIATION...
With cumulus quickly dissipating before sunset, vfr skc conditiosn
overnight. Some areas of fog possible after 06/08z at mainly kmlu
and keld. Low cloud return from gulf overnight will remain mostly
west of the cwa, although a few mvfr clouds may briefly affect
klfk. Lgt winds overnight becmg s-se 5 to 10 kts durg day Monday
as upper lvl clouds begin to increase. Isold cumulus possible in
aft at mainly ktxk and keld terminals./07/.
PREV DISCUSSION... /issued 404 PM CDT Sun May 5 2019/
SHORT TERM.../Tonight through Monday Night/
Sfc-H850 ridging anchored over the region this afternoon will
begin to shift E into the Lower MS Valley later tonight, with a
return SSE low level flow expected to commence with its departure.
This return flow will be light initially, but given the ample
insolation much of the area has received today once the stratocu
field had scattered out, any FG tonight should remain quite
patchy than what was observed this morning, and thus have omitted
mention from the forecast. Sct elevated convection has just begun
to fire this afternoon along the dry line in W TX, ahead of weak
shortwave energy that will progress E into the Srn Plains later
tonight. There is good agreement with the 12Z short term progs
suggesting that this convection will spread E across Cntrl OK and
WCntrl TX late this evening, before gradually weakening after 06Z
as this shortwave enters Ern OK and ECntrl TX. The deep lyr
moisture will be much more shallow across E TX into Wrn AR,
although there is some agreement with the 12Z HREF and latest HRRR
runs suggesting that some of this decaying elevated convection may
reach McCurtain County OK just prior to daybreak Monday, and for
this reason, have included slight chance pops for this area late
tonight before encountering a much drier and more stable air mass.
With the sfc ridge easing E of the region later this evening, min
temps tonight should be a bit milder than what was observed this
morning, especially over E TX/SE OK/adjacent SW AR/Wrn LA.
The low level moisture should again remain shallow Monday despite
the weak return Srly low level winds, with a sct cu field at best
beneath some residual elevated cirrus near and beneath the
passing/exiting shortwave trough. Another day of strong insolation
is expected, with max temps returning back above normal as most
areas top out in the mid 80s. However, this brief drying trend
will begin to end as the zonal flow aloft begins to transition to
SW by Monday night, with the progs in general agreement with an
initial shortwave trough over S TX beginning the shift NE into E
TX Monday night. While amplitude and timing discrepancies remain
with this approaching trough, there is general agreement
suggesting that some mainly elevated convection will develop over
Cntrl and SE TX and gradually spread ENE into the Wrn portions of
E TX just prior to daybreak Tuesday. The majority of the progs
suggest that much of the convection will await until after
daybreak before affecting much of E TX, and thus have tapered pops
down to slight chance for the Wrn sections of E TX, with the low
level moisture gradually deepening from W to E across the area
during Tuesday.
15
LONG TERM.../Tuesday through Saturday Night/
A series of upper troughs will lead to a prolonged period of
unsettled and wet weather for almost all of the long-term forecast
period. The first shortwave trough will move across East Texas and
South Louisiana on Tuesday. Rain chances should increase from
southwest to northeast during the daytime hours of Tuesday, with the
highest rain chances expected to be mainly across the Toledo Bend
Country of Western Louisiana and across East Texas south of
Interstate 20. Despite the rain and cloud cover, daytime high
temperatures will likely still be near or above normal in most
locations. Portions of Southern Arkansas and North Central Louisiana
may warm into the mid 80s due to the lower rain chances.
There may be a brief decrease in convective activity as the initial
shortwave departs to the east. However, another upper trough should
be over the Four Corners Region by Tuesday evening. As the upper
trough slowly moves northeast from the Southern Rockies into Kansas
on Wednesday, a surface low over the Southern High Plains will
rapidly develop and lead to a sharpening dryline trailing southward
from the low. Thunderstorms should develop ahead of the dryline
increasing in coverage and intensity while moving eastward towards
the Four State Region. Current thinking is a rather intense line of
storms will develop and move across our area from mid to late
morning through early to mid Wednesday evening. There should be
enough instability and deep layer shear to support severe
thunderstorms. Shear profiles above 850 hPa will generally be
unidirectional, which tends to favor a linear storm mode. However,
backed surface winds could provide just enough low-level shear to
yield an isolated tornado threat. The dryline will stall west of the
area, and convection is expected to redevelop Thursday both along
residual outflow boundaries left over from Wednesday and along the
cold front as it dives south towards the Gulf coast. More severe
weather will be possible Thursday.
The threat for severe weather should diminish by Thursday evening,
but the front will stall just north of the Interstate 10 corridor
over South Louisiana. Another cutoff trough over Southern California
will keep southwesterly flow and a rich plume of Pacific moisture
over the area. Isentropic ascent over the stalled frontal boundary
should tap into this moisture keeping high chances for rain in the
forecast Friday, especially south of Interstate 20. However, rain
chances may begin to diminish across the northern half of the area
on Saturday. Through Saturday evening, rainfall totals will likely
be above three inches across much of the area. Model guidance
continues to come into better agreement with the primary axis of the
highest amounts, which could be between six and eight inches,
generally southeast of a line from Tyler TX to El Dorado AR. Given
all of the rain the area has recently received, this forecast
certainly increases the potential for more flash flooding and
river/lake flooding in the coming days and weeks.
CN
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 62 86 65 82 / 0 0 10 30
MLU 58 85 63 85 / 0 0 0 10
DEQ 59 83 62 80 / 10 10 10 20
TXK 62 84 64 80 / 0 0 10 20
ELD 58 84 63 84 / 0 0 0 20
TYR 63 86 65 80 / 0 0 20 50
GGG 63 86 64 80 / 0 0 20 40
LFK 62 87 66 80 / 0 0 20 70
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...None.
LA...None.
OK...None.
TX...None.
&&
$$