Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 05/07/19
Area Forecast Discussion...UPDATED
National Weather Service Amarillo TX
601 PM CDT Mon May 6 2019
.AVIATION...
Thunderstorms may affect the AMA TAF site this evening. At this
point it appears that DHT and GUY will miss out on the
thunderstorms. Low clouds in the MVFR range are expected to
develop across AMA late tonight. These clouds may hang on for much
of day on Tuesday. GUY and DHT will likely have IFR/LIFR cigs
behind a cold front starting tonight. These low clouds are
expected to continue through the day on Tuesday. Winds will be
gusty from the south and southeast through Tuesday at AMA. Winds
will switch around to the northeast at GUY and DHT behind the cold
front overnight.
&&
.PREV DISCUSSION... /Issued 423 PM CDT Mon May 6 2019/
SHORT TERM...
PREV DISCUSSION... /Issued 241 PM CDT Mon May 6 2019/
SHORT TERM...This Afternoon through Tonight...
A mid-level shortwave is currently in the western Panhandles and
generating clouds. Radar is showing some precip up in southeastern
Colorado, where the wave meets the lee-side low that is
developing. Hi-res models are not showing convection starting this
soon; however, the HRRR about 2 hours ahead of now looks to match
up for precip location as well as the current temperature for
Amarillo. If we follow the HRRR staying 2 hrs ahead, we could
expect storms to pop in the Panhandles around 21Z. This would
likely match up well for the next shortwave to come into the
Panhandles. Forecast soundings for the HRRR show 1500-1800 J/kg
for CAPE available. The NAM shows forecast CAPE to be 2500-3000
J/kg. Short range models have been all over today with what will
happen with storms today. Some want to kick off just a few storms
that don`t look very impressive while other models produce more
storms that could have large hail, damaging winds, and a possible
tornado threat. Current best thoughts will be a few storms will
form with the possibility for large hail and damaging winds. Storm
motions will be slow, so localized flooding could be a problem as
well. Models bring the cold front to the Oklahoma border
overnight which could keep some precip in the northern zones
overnight. Not expecting severe weather from that precip. It could
however help set up a baroclinic zone for tomorrow`s convection
with low clouds hanging around tomorrow morning in the north while
the southern zones are clear and warming.
Beat
LONG TERM...
Tuesday through Monday...
Main concern remains threat for severe thunderstorms Tuesday,
mainly during the afternoon and evening. Dryline expected to
sharpen across western sections by Tuesday afternoon. Uncertain
of depth of intrusion of cold into northern sections and/or its
possible movement northward as a warm front. Both of these
boundaries will provide focusing mechanisms for thunderstorm
development. Airmass expected to be very unstable and adequately
sheared for strong to severe thunderstorms. Rich and deep
moisture will also be in place, leading to the potential for heavy
rains and the threat for flooding or flash flooding Tuesday
afternoon and evening.
Models in general agreement that Pacific cold front will move
eastward across the Texas and Oklahoma Panhandles during the
morning on Wednesday before polar cold front passes during the
afternoon and morning. Much cooler and more stable air arrives with
passage of polar front, with threat for thunder greatly reduced
Wednesday night and Thursday, with only rain showers expected.
Thursday expected to be coolest day of the forecast, when highs
fall about 20 degrees short of climo. Highs Friday and Saturday
also remain below normal with highs in the 60s. Rain showers
possible again Friday and Friday night as southeast low-level flow
resumes with departure of cool surface ridge. Return of modest
amounts of moisture and instability expected to support mention
of thunder Saturday and beyond. Severe threat looks low Saturday
through Monday owing to relatively cool conditions.
Cockrell
&&
.AMA Watches/Warnings/Advisories...
TX...None.
OK...None.
&&
$$
15/11
Area Forecast Discussion...UPDATED
National Weather Service Fort Worth TX
639 PM CDT Mon May 6 2019
.AVIATION...
/00z TAFs/
VFR conditions and SSE winds currently prevail at all TAF sites
which should continue through tonight. Around daybreak tomorrow,
MVFR stratus should overspread parts of North and Central Texas,
resulting in BKN cigs near or above 2 kft at the TAF sites. Some
lower cigs closer to 1 kft are possible at Waco. Statistical
guidance seems a bit to aggressive with prevailing MVFR almost
all day, but think a fairly quick improvement trend should
commence by late morning with cigs lifting to VFR for the
afternoon. Increased warm advection should allow showers and
perhaps a few storms to percolate with aid from diurnal heating,
and will continue some VCSH mentions through the afternoon. The TS
potential is less certain, and at this time confidence in
thunderstorm occurrence at DFW area airports is too low to warrant
inclusion in the TAFs right now. Chances appear to be a bit
better to the south and east, and will retain a VCTS mention at
Waco. Convective activity should decrease Tuesday evening with a
lull expected during the overnight hours. Additional low cigs may
precede an organized squall line Wednesday morning, both of which
will be addressed in subsequent TAFs.
-Stalley
&&
.DISCUSSION... /Issued 326 PM CDT Mon May 6 2019/
Afternoon water vapor imagery and RAP 500mb analysis indicate the
presence of a weak shortwave moving out of northern Mexico,
resulting in a complex of showers and thunderstorms across Deep
South Texas. This activity should continue northeastward along the
coast and into the Gulf of Mexico over the next several hours.
Other than some high level cirrus from this system, we`ve remained
generally precipitation free owing to some subsidence on the
north side of the complex. We should remain rain free most of the
evening and overnight, but we`ll hang on to some very low PoPs
across the far southern counties where some of this rain could try
to sneak into. It`ll be a warm night with overnight lows in the
upper 60s areawide.
On Tuesday, a compact shortwave trough currently over southern
California will spread eastward into the 4-corners region with a
100 kt upper jet nosing into west Texas. Farther east across our
area, persistent southerly flow and modest moisture advection will
lead to a relatively unperturbed warm sector with dewpoints in the
mid to upper 60s, although abundant low cloud cover will be in
place early in the day. With the shortwave trough well to the
west, large scale forcing for ascent will generally be absent from
the region, but strong heating by late morning into the afternoon
should result in surface parcels being able to reach their
convective temperatures fairly early. This should result in an
uptick in showers and a few thunderstorms, particularly south of
I-20. We`ll show increasing PoPs from south to north from late
morning through afternoon. Weak deep layer shear but strong
instability should support weakly organized clusters of storms
with primarily a strong wind threat through the afternoon. This
activity should be primarily diurnally driven with a decrease in
coverage by sunset.
The main concern for North and Central Texas appears to arrive
late Tuesday night into Wednesday morning. On late Tuesday
afternoon, as the upper shortwave spreads strong forcing for
ascent into the TX Panhandle, supercell thunderstorms are expected
to develop well west of our area. These should initially move
east-northeast with most of the activity remaining to the
northwest of our area by dark. As we get into the nighttime hours,
a low level jet strengthening to 40 kt will feed into a congealing
cluster of severe thunderstorms, allowing for the upscale growth
of a linear complex of storms by midnight. The orientation of a
broad 35-40 kt low level jet, along with a broad axis of
instability (1500-2000 J/kg) across North Texas late Tuesday night
suggests that MCS propagation will be east-southeast into our
region overnight Tuesday night. If this scenario pans out, which
is supported by most of the high resolution and global guidance,
it is unlikely that we`ll see a significant severe weather episode
on Wednesday. Usually when we get organized complexes of
thunderstorms through the region during the morning hours, it
becomes difficult for the atmosphere to recover in the absence of
a deep surface cyclone in the Plains to help strengthen moist
southerly flow or the absence of an additional upstream shortwave
trough.
Not to downplay the severe threat completely, but our current
thinking is that a linear complex of storms will develop and move
through during the late overnight/early morning hours on
Wednesday. This complex in itself could be severe with primarily a
damaging wind threat, even during the early morning hours. We`ll
have high PoPs across the northwest late Tuesday night, and across
most of the area before midday Wednesday, with considerably lower
PoPs Wednesday afternoon with the thinking that the atmosphere
across the region will be too worked over for additional severe
storms. This obviously comes with a big caveat. If the complex of
storms is considerably weaker or doesn`t pan out at all, then we
should have a pristine boundary layer to work with during peak
heating on Wednesday. An eastward surging dryline and convergence
along a southward moving front would be the primary foci for
convective development given that the shortwave will have pulled
off to the northeast. All modes of severe weather would be
possible in that scenario. It must be stressed that even with the
enhanced risk for severe weather in place across the region,
confidence is widespread significant severe weather is low.
The aforementioned cold front should swing through the region
late Wednesday night into Thursday and will result in some drier
and cooler air filtering into the region. The front will get hung
up across Central Texas and should become a focus for additional
precipitation through the end of the week and into the weekend.
The upper pattern will continue to feature broad troughing over
the western U.S. with periodic shortwave troughs ejecting into the
Plains. It won`t rain everywhere every day, but areas south of
I-20 will have the best chances Thursday into Friday night. The
late week severe weather threat is generally low.
Dunn
&&
.PRELIMINARY POINT TEMPS/POPS...
Dallas-Ft. Worth 68 82 69 81 67 / 5 40 60 80 20
Waco 68 80 69 79 68 / 10 50 40 80 20
Paris 64 82 66 77 67 / 5 30 50 90 60
Denton 67 82 68 81 64 / 5 30 70 80 10
McKinney 66 80 68 79 67 / 5 40 60 80 30
Dallas 69 82 69 81 67 / 5 40 50 80 20
Terrell 67 82 68 81 67 / 5 50 40 80 30
Corsicana 67 80 68 78 68 / 10 50 30 80 40
Temple 67 79 69 80 68 / 20 50 30 70 20
Mineral Wells 66 82 65 81 61 / 10 30 70 70 5
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
26/24
Area Forecast Discussion
National Weather Service Hastings NE
631 PM CDT Mon May 6 2019
.SHORT TERM...(This evening through Tuesday)
Issued at 353 PM CDT Mon May 6 2019
Showers and thunderstorms have been continuing during the afternoon,
but have been diminishing in the southwest part of the forecast
area. Clouds have a strong hold on the area. A warm front extends
through north central Kansas and is just south of the forecast area
at this time.
The thunderstorm potential has been a challenge this afternoon. The
short term models have not been handling the ongoing convection very
well, which leads to less confidence in the next few hours.
Initially, expected thunderstorms more this afternoon and evening,
but the morning and early afternoon convection has changed the
atmosphere. The latest run of the HRRR is finally starting to show
the current convection. Expect that the current convection should
continue to move to the east/northeast this afternoon and the
stronger thunderstorms will develop along the warm front a little
later in the afternoon/early this evening. There is also more
clearing to the south of the front which is making the temperature
difference along the front stronger.
The timing of the thunderstorms is a little bit of a challenge for
this evening. Expect that they will be a little later with the
daytime convection, so have pushed back the higher PoPs until a
little later.
There is a small flood threat with these thunderstorms. There could
be some heavy rainfall with the thunderstorms tonight and some could
train over the same locations. Most of this should be to the south
of the forecast area, but will need to watch the far southern part
of the area. The current flash flood guidance is for a couple of
inches. At first, it should be ok, but later on there could be a
concern. Will not be issuing any flood watches at this time.
Showers and some thunderstorms are possible across the area through
the night, but expect that the thunderstorm chances will be further
to the south. Showers and thunderstorms will continue into the day
on Tuesday with the better chances during the afternoon.
Precipitation amounts should be a little less during the day.
.LONG TERM...(Tuesday night through Monday)
Issued at 353 PM CDT Mon May 6 2019
The warm front that will be the focus of the thunderstorms tonight
will continue to linger in the vicinity, mainly to the south of the
forecast area Tuesday night into Wednesday, will move to the
southeast as a cold front Wednesday night. There will be chances for
thunderstorms Wednesday, then there will be showers that continue
through Wednesday night.
By Thursday, there will be a surface high that settles into the
area. Even with the surface high, there will be clouds that linger
during the day on Thursday, but start to clear out for Thursday
night. This creates a challenge for temperatures. The clearing skies
and light winds will allow the temperatures to fall off and there is
a chance for some frost, mainly in the northwest part of the
forecast area. That being said, the most clouds remain in the area
where the frost is which could keep temperatures from falling as
far. Will need to watch the temperatures during this period.
Friday and Friday night should remain dry and temperatures will warm
up a little from Thursday. The next wave will move through the area
Saturday afternoon and evening. There could be a few showers and
thunderstorms as the wave moves through.
Another dry period is expected Sunday and Monday. Temperatures will
warm up a little.
&&
.AVIATION...(For the 00Z KGRI/KEAR TAFS through 00Z Tuesday)
Issued at 625 PM CDT Mon May 6 2019
Models in good agreement showing the low level stratus not going
anywhere through this TAF period, and kept ceilings sub-1000ft the
entire time. There will be chances for at least scattered
precipitation later things evening and into tomorrow. Not
expecting much change in the winds, remaining generally easterly,
with sustained speeds around 15 MPH...could have occasional gusts
closer to 20 MPH.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...None.
KS...None.
&&
$$
SHORT TERM...JCB
LONG TERM...JCB
AVIATION...ADP
Area Forecast Discussion
National Weather Service Mobile AL
828 PM CDT Mon May 6 2019
.DISCUSSION...See updated information for land areas below.
&&
.UPDATE...Current forecast remains largely on track. With high
pressure over the region and fair skies tonight, some shallow fog
will again likely develop along river basins and low lying areas
and burn off rapidly after sunrise. /08
&&
.PREV DISCUSSION... /issued 632 PM CDT Mon May 6 2019/
DISCUSSION...Updated for latest aviation discussion below.
AVIATION...
00Z issuance...VFR conditions and light winds prevail through the
24-hour period. /49
PREV DISCUSSION... /issued 400 PM CDT Mon May 6 2019/
NEAR TERM /Now Through Tuesday/...Short-wave mid level ridge
advances eastward over the central Gulf coast in the near term
with a dry deep layer airmass to hold in place. At the surface,
weak high pressure slips eastward over the southeast US and
eastern seaboard thru Tuesday. Overnight lows tonight in the mid
to upper 50s interior to mid 60s closer to area beaches. The short
range ensembles indicate a small probability (10 to 20% chances)
of patchy late night fog development mainly aligned from southern
MS eastward into Mobile and Baldwin Co`s in AL. This is also
supported by the latest high resolution RAP and NAM outputs. Will
mention patchy late night fog in the forecast mainly over the
southwest zones. Under the short-wave mid level ridge, 1000-850 MB
thickness values are favored to increase during the day Tuesday
resulting in daytime highs some 6 to 8 degrees higher than
climatology. In fact, the latest forecast shows a few areas
getting into the lower 90s on Tuesday. These numbers will be
nearing record warmth in those areas for May 7th. /10
SHORT TERM /Tuesday night Through Thursday night/...A persistent
light south to southeast wind flow will occur through the short
term as a surface ridge of high pressure remains across the
southeast states and northeastern Gulf of Mexico. An area of low
pressure at the surface is forecast to develop across the Texas
panhandle by late Tuesday night, and lift northeast to the central
Great Lakes by Thursday night. Overall moisture is expected to
gradually increase throughout the short term.
Meanwhile, a weak upper level ridge of high pressure over the
southeast states will shift eastward over the western Atlantic
midweek, followed by a weakening upper level shortwave passing
over the lower Mississippi River. A dry weather pattern will
persist through midweek, with the exception of isolated showers
and thunderstorms west of the Tombigbee River on Wednesday. As the
surface low pressure area lifts northeast, an associated cold
front will approach the region from the northwest Thursday and
Thursday night, but stall before reaching the forecast area. An
upper level ridge of high pressure will build over the Gulf of
Mexico on Thursday, with another upper level shortwave passing
over the lower Mississippi River. This pattern will give us a
better chance of showers and thunderstorms on Thursday, especially
northwest of a line from Wiggins, Mississippi to Camden, Alabama
where widespread one-half to one inch of rainfall is expected. /22
LONG TERM /Friday Through Monday/...The upper level ridge of high
pressure will remain over the Gulf of Mexico into the weekend, and
then breakdown as a large upper level trough passes over the
eastern conus over the weekend into Monday. A moist west to
southwest flow aloft will prevail across our region prior to the
passage of the upper trough. This pattern, along with a persistent
moist southerly low level flow and a weak surface boundary
remaining just northwest of the forecast area will support keeping
scattered to definite showers and storms in the forecast each day
through the end of the long term, with heavy rain possible. /22
MARINE...No impactful weather in the near term. An evolving
moderate onshore flow into the middle of the week sets up between
high pressure to the east and a frontal boundary slipping eastward
out of the southern Plains and across TX. The result is a gradual
build in seas. Chances of storms increase Thursday through
Saturday. /10
&&
.MOB WATCHES/WARNINGS/ADVISORIES...
AL...None.
FL...None.
MS...None.
GM...None.
&&
$$
This product is also available on the web at:
http://weather.gov/mob
Area Forecast Discussion
National Weather Service Topeka KS
958 PM CDT Mon May 6 2019
.UPDATE...
Issued at 958 PM CDT Mon May 6 2019
Elevated thunderstorms have become a little more numerous across
north central KS. I think this trend is likely to continue with
more widespread showers and storms moving east across the area
overnight. Area profiler data shows low level winds at 850MB are
from the south and southeast. Models show this flow is promoting
isentropic upglide across the area. Additionally models indicate
an MCV from the convection off the high plains could lift across
northeast KS through the mid morning hours. So forcing and lift
along with continued low level moisture advection into northern KS
should promote increased coverage of storms. Forecast soundings
from the RAP show steep mid level lapse rates around 7.5 C/km with
reasonable effective bulk shear. So the risk for severe storms
could persist for several more hours. Flooding concerns will also
be on the increase with good moisture advection expected through
the night.
&&
.SHORT TERM...(This evening through Tuesday)
Issued at 350 PM CDT Mon May 6 2019
The region enters an active weather pattern starting late this
afternoon through tonight with severe weather and heavy rainfall
the main threats.
Early afternoon water vapor imagery depicted a quasi-zonal flow
WSW flow pattern across the Central Plains early this afternoon
with an upper level trough over the Northern Plains and low-
amplitude ridging across the Southwest Plateau. A cutoff low
making landfall over the California coast will produce a gradual
amplification of this zonal flow pattern throughout the course of
the period, with a more pronounced ridging and SW flow over the
High Plains. At the surface, early morning convection pushed the
effective baroclinic zone to along and south of the I-70 corridor,
but increasing southerly return flow and theta-e advection noted
in GOES-E PWAT imagery, visible satellite data, and surface
observations, will aid in lifting this relatively shallow
convergence zone back northward-- though how far northward remains
somewhat in question. The 19Z surface analysis shows that the
boundary has moved little in the last couple of hours, lending
credence to a more southerly solution taking the boundary to
around or just south of the I-70 corridor during peak heating.
Elevated multi-cell clusters with embedded supercell structures
developed around midday in north-central Kansas and south-central
Nebraska along the nose of the 500-1000 J/kg MUCAPE gradient and
have spread eastward along with this elevated instability/moisture
plume. Multiple reports of large hail have been received from
these storms This convection will aid in a southern reinforcement
and sharpening the boundary. This elevated convection should
persist for much of the afternoon and evening hours with
additional development further south and west closer to the nose
of the MLCAPE plume now located from Salina to Hays. The backing
of the low-level winds along the boundary has resulted in
effective helicity values rising to 200 to 400 m2/s2 and effective
shear values of 30-50 kts, and this environment should persist
and shift gradually east through the late afternoon and evening
hours.
Initially discrete supercells could develop within this corridor,
with a gradual upscale growth with merging cold pools later
tonight. With right-moving supercell motions paralleling the
boundary orientation, any storm that does ride this baroclinic
zone will have an increased risk for producing a tornado,
potentially on the longer-lived side. Additional convection
forming along the Front Range in response to an ejecting H500
shortwave will track eastward on the heels of this first round and
expend in coverage as it interacts with isentropic upglide over
the broad surface to H850 front. With PWATS of 1 to 1.5 inches and
increasing mid-level mixing ratios, the environment will be
primed for multiple rounds of training cells that could drop
several inches of rainfall during the late overnight hours. Have
increased QPF amounts along and south of the I-70 corridor to
account for this likelihood.
This convection may linger throughout the day on Tuesday, though
confidence decreases in its spatio-temporal characteristics. The
cold pools from this convection should usher the boundary
southward into southern Kansas, but more recent model runs are
hinting at the boundary lifting back northward towards the I-70
corridor as lee cyclogenesis intensifies on the Front Range
Tuesday afternoon. Should this latter solution transpire, we will
likely see a renewed severe weather threat along and south of I-70
tomorrow afternoon.
.LONG TERM...(Tuesday night through Monday)
Issued at 350 PM CDT Mon May 6 2019
Tuesday night into Wednesday will continue to see active weather
across the region, with quieter weather to end the week.
Additional rounds of strong to severe thunderstorms are likely
along and south of the warm front Tuesday afternoon and evening
with similar hazards to this afternoon. Additional moisture
transport along and up the front will provide another round of
heavy rainfall Tuesday night into Wednesday morning with one final
round of showers and storms Wednesday afternoon and evening as
the main lee cyclone ejects northeastward. Severe weather will
once again be possible Wednesday afternoon and evening with the
track of the low dictating the threat for tornadoes. The pattern
then cools and dries out for the end of the week as high pressure
builds southward, with the next chance of precipitation coming
over the weekend as as frontal boundary moves through.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 634 PM CDT Mon May 6 2019
Confidence is low in the forecast because the models seem to be
all over the place with showers and storms. There does appear to
be a signal for a shortwave to lift through the area late tonight.
So the thinking is once the current convection passes through,
there will be a break for several hours. Then additional showers
and storms could overspread the area during the overnight hours.
Have removed the mention of precip by the late morning thinking
subsidence behind the shortwave will bring another break from the
precip. Again this is a low confidence forecast and likely will be
amended.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
Flash Flood Watch through late Wednesday night for KSZ008>012-
020>024-026-034>040-054>056-058-059.
&&
$$
UPDATE...Wolters
SHORT TERM...Skow
LONG TERM...Skow
AVIATION...Wolters
Area Forecast Discussion
National Weather Service Tulsa OK
947 PM CDT Mon May 6 2019
...UPDATE...
.DISCUSSION...
This evening...convection was continuing to develop along a
surface front stretched across Kansas and along a dryline in the
Texas Panhandle/West Texas. To the south...a weak upper low was
located over the Texas Gulf Coast which was making its way east
northeast and pushing high level clouds across much of Eastern
Oklahoma and Northwest Arkansas. At the surface...for the
CWA...southerly low level flow was lifting the upper 60s/70 degree
dewpoints into Kansas with more mid 60 dewpoints south of I-40.
At the same time...with the loss of day time heating...the cap was
increasing northward into Northeast Oklahoma and also Northwest
Arkansas. Quite a bit of elevated instability remained over the
region while the better shear values where with the ongoing
convection across Kansas.
Overnight tonight...the ongoing convection...which has already
begun to develop into a MCS...is forecast to push east and southeast
into Southwest Missouri following the instability axis. Latest
HRRR runs indicate the MCS coming close to the northeast corner
of the CWA as it begins a more southeasterly push tonight...though
keeping it in Kansas and Missouri. With the strengthening cap and
the elevated instability forecast to weaken/lift northeast...have
lowered pops across much of the CWA for tonight into Tuesday
morning. Have continued with chance pops along the Kansas and
Missouri borders for the potential of the MCS. If the MCS does
push into far Northeast Oklahoma and far Northwest Arkansas...a
limited severe potential could be possible with locally damaging
winds the main threat. Also...locally heavy rainfall could become
a concern within any thunderstorm activity.
Increasing cloud cover along with dewpoints remaining in the 60s
overnight low temps should also remain in the low/mid 60s for most
locations. For the evening update...have added minor tweaks to
hourly temp/dewpoint grids based on latest trends and
observations...and also adjusted pops based on the mentioned
above. The rest of the forecast seems to be handling well at this
time.
&&
.PRELIMINARY POINT TEMPS/POPS...
TUL 65 82 65 79 / 20 20 70 80
FSM 64 87 65 78 / 10 20 60 80
MLC 64 83 66 79 / 10 20 70 80
BVO 63 79 64 76 / 30 30 80 70
FYV 63 82 64 74 / 20 20 60 80
BYV 62 83 63 76 / 40 20 50 80
MKO 64 82 64 77 / 10 20 70 80
MIO 64 82 64 76 / 40 30 70 80
F10 65 82 65 79 / 10 20 70 80
HHW 64 82 66 77 / 10 20 70 90
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...None.
AR...None.
&&
$$
SHORT TERM...20
Area Forecast Discussion
National Weather Service Las Vegas NV
620 PM PDT Mon May 6 2019
.SYNOPSIS...An atypical weather pattern this week will bring
increasing chances for showers and thunderstorms, especially later
in the week as a series of weather features come together. Expect
periods of gusty winds across portions of the area this week and
cooler temperatures as we approach the weekend.
&&
.EVENING UPDATE...
Made some adjustments to PoP/Wx grids due to ongoing radar trends.
Most model depictions were having a hard time resolving the upslope
winds creating convection on the Spring Mountains and underdoing
precip development over the northern Mohave County area. Added some
PoP and QPF in these areas. Also made some minor changes to the wind
grids for the valley as continued southeast winds are stubborn to
shift to the southeast as hi-res models are eager to do.
HRRR trends continue to indicate an area of showers and possible
thunderstorms pushing through the Colorado River Valley south of
Laughlin overnight tonight. This was well captured in the grids
currently so left this unchanged for now.
.DISCUSSION...through next Monday.
Low pressure currently centered along the southern California
shoreline is generating some high-based cumulus across our area this
afternoon. Seeing dry conditions and gusty winds 20-30 mph. Tonight,
the low tracks east across the southern California deserts into west
central Arizona. The best chance for showers and isolated storms
will be near the low center which hugs our far southern CWA as the
low moves east. Tomorrow, the low opens up and weakens as it lifts
off to the northeast across Arizona. The next disturbance moves
south through Utah Tuesday night with the trough axis staying east
of the forecast area. Moisture and instability is generally limited
to the eastern portions of the FA on Wednesday including eastern
Lincoln County and Mohave County where the best chance of seeing
showers and storms exists. In addition, a stray shower or two may
form over the Clark County mountains Wednesday afternoon.
A complex weather pattern develops in the second half of the week
bringing better precipitation chances to our area. A broad area of
low pressure forms over the Intermountain Region Wednesday night
with strong high pressure off the Pac NW coast. In the meantime, low
pressure approaches from the eastern Pacific. On Thursday, the high
remains anchored off the Pac NW coast while the low over the
Intermountain Region retrogrades southwestwards. The low approaching
from the west is forecast to weaken as it encounters the westward
retrograding low which, in turn, strengthens. The energy from the
approaching low gets ejected inland well south and east of our area
on Friday while the retrograding low becomes better developed as it
positions itself off the southern California coast. The low off the
So Cal coast moves inland and tracks east along or south of the
U.S./Mexico border through the weekend. Plenty of moisture is
available for shower/storm development in our area Saturday
afternoon and possibly Sunday afternoon.
The area will see elevated, gusty winds at times through the week
with increasing chances for thunderstorm induced strong winds.
Temperatures will tumble to well below normal by Thursday and remain
there through Saturday before warming back to around normal early
next week.
&&
.AVIATION...For McCarran...Southeast winds between 10-20 kts are
expected through much of the afternoon and into the early evening
before shifting more to the southwest after 02z this evening. Wind
speeds should generally decrease to around 10 kts after this point.
Some flat cumulus around with bases around 12k feet. There will be a
chance of thunderstorms in northwest Arizona overnight affecting the
Peach Springs approach corridor. East to southeast winds are
forecast to develop after 16z Tuesday with Few-Sct clouds around 12k
feet. There will be a a slightly better chance of seeing afternoon
showers and thunderstorms around the Las Vegas Valley affecting the
Beatty, Mormon Mesa, and Peach Springs corridors.
For the rest of southern Nevada, northwest Arizona and southeast
California...A circulation will slowly move from the southern
California Coast to southern Nevada this evening and overnight. This
will help produce isolated thunderstorms overnight across portions
of northwest Arizona mainly south of Kingman. Periods of southwest
to west winds gusting 25-30 knots will continue across the western
Mojave Desert and KDAG into this evening before diminishing. Other
sites will see southerly winds gusting around 20 knots into this
evening before decreasing to around 10 kts overnight. There will be
a slight increase in shower and thunderstorm chances Tuesday mainly
across southern Nevada and northwest Arizona.
&&
.SPOTTER INFORMATION STATEMENT...A series of systems will begin to
impact the region this week, with the most impactful weather
expected in the second half of the week. Spotter activation is not
anticipated at this time, but may be needed later in the week.
&&
$$
UPDATE...TB3
DISCUSSION...Salmen
AVIATION.....Gorelow
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