Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 05/03/18
Area Forecast Discussion
National Weather Service Brownsville TX
633 PM CDT Wed May 2 2018
.DISCUSSION...Updated for latest aviation discussion below.
&&
.AVIATION...Surface observations and satellite imagery shows that
MVFR ceilings have developed at BRO and HRL under broken to
overcast conditions. VFR conditions remain at MFE at the issuance
time of this discussion. This will be short lived as MVFR
ceilings will be expected to develop this evening at MFE as clouds
increase. Low end MVFR conditions develop at the TAF sites during
the overnight. Steady breezy southeasterly winds will be expected
to continue tonight and will once again pick up a bit more during
the afternoon on Thursday with gusts up to near 30 knots. Daytime
mixing on Thursday will allow for ceilings to raise to VFR levels
and for clouds to gradually break into and through the afternoon.
&&
.PREV DISCUSSION... /issued 251 PM CDT Wed May 2 2018/
SHORT TERM (Now through Thursday Night): Mild, muggy nights with
seasonally warm and a breezy/windy daytime will continue through
the short-term. Latest GOES-16 mid-level water vapor channel and
RAP analysis shows mid/upper-level low spinning over NW Arizona.
As the low elongates over the next 36 hours, the southern portion
of the trough will hang back over the Desert Southwest,
maintaining generally SW aloft over Deep South Texas. SE winds
will continue at the surface, between a low emerging into the lee
of the Rockies and the Bermuda high over the western Atlantic. The
gradient will finally weaken somewhat by late in the day on
Thursday as the low scoots off toward the upper Midwest.
As far as the details go, tonight`s lows should be in the mid-
upper 70s F, much like last night. Dewpoints also in the 70s will
make for a muggy feel, even with winds staying up near 15mph much
of the night. Not seeing much in the way of precip chances as
column moisture remains too shallow. Some near-term guidance
indicating that a weak shortwave in the SW mid-level flow or
dissipating showers coming off the higher terrain in Mexico may
reach the western CWA, but will hold PoP`s at 10% even there.
Mostly precip-free again on Thursday, though moisture continues
to pool over the northwestern Ranchlands ahead of surface
troughing/dryline over west-central TX. PW values rise to
1.7-1.8", but not any forcing to speak of. Temps should be rather
similar to today`s, with heat indices again pushing 100F along the
Rio Grande. Winds will still be on the breezy side, but a bit
less than today.
Some subtle changes come into play Thursday night. RH deepens (to
roughly H85) across the area, especially out west. Models
indicate overnight convection over the mountains of Mexico and/or
possible shortwaves rotating northward. Environment will be
relatively low CAPE/high CIN, though, and model QPF`s very low.
Will paint a slight chance of showers and thunderstorms after
midnight, mainly for Zapata/Starr/Jim Hogg/Brooks counties.
LONG TERM (Friday through Wednesday): High pressure over the Gulf
will continue to pump moisture into the region on Friday, pooling
up to around two inches inland ahead of an approaching cold
front, while a mid level short wave trough over the southwest
United States will continue to shear out and eject north and east.
The positive tilt trough will line up well over the weak surface
front moving southeast over Texas Friday and Saturday, helping to
steer any deeper convection developing in Mexico along the
boundary from west to east as well as possibly enhancing
instability. Strong weather will have better ingredients for
development over west Texas on Friday; however, mid level
perturbations moving over the Sierra Madre Orientals may enhance a
few moderate to strong thunderstorms which could then threaten
the CWA, especially during the overnight hours. As the front
stalls out over the area Friday night, the weak ejecting short
wave trough will push south and over the area, and this may be an
opportunity for a few thunderstorms to develop Friday night
through Saturday night. The best chance for storms to move into
the RGV, especially along the Rio Grande will be Friday and
Saturday nights, and with PWAT values expected to be relatively
high, above the 90th percentile, locally heavy downpours may
occur, especially if the expected training from the upper flow
develops. Friday night convection may be a little farther upstream
than that of Saturday night, but could definitely propagate down
river.
Conditions should settle down by late Sunday with mid level ridging
moving overhead and surface high pressure settling over the west
Gulf. The front should be south of the area by Sunday night, and
lingering convection would then be restricted to beyond the CWA.
Ridging will be over the area Monday and Tuesday as winds return to
southeast and temperatures, already near to slightly above normal,
will inch higher.
MARINE:
Now through Thursday: Small Craft Advisory (SCA) for Winds
currently in effect on the Laguna Madre seems to be verifying
reasonably well early this afternoon. It currently runs through
7am Thursday, but evening crew may have to take a look at ending
early (possibly around midnight) if winds de-couple. SCA will be
taking effect on the Gulf waters shortly (at 3pm CDT). May be a
little slow to get going, with current ob only indicating winds of
14G19KT with seas around 5 ft. Still confident that winds and
seas will come up this evening as low-level jet re-develops,
though. SCA`s may well need to be extended into Thursday afternoon
for all waters before gradient starts to weaken and Gulf seas
eventually subside to SCEC levels Thursday evening.
Friday through Monday night: Moderate southeast winds Friday and
Friday night will decrease to light to moderate Saturday through
Monday night, shifting to the northeast to east as a weak front
approaches and moves through the area. Offshore wave heights may
still be slightly elevated Friday, with possible small craft
exercise caution or brief small craft advisory conditons, but will
also decrease through the remainder of the long term. Showers and
thunderstorms will be possible Friday night through Sunday as a
weak cold front edges south through the marine areas.
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...None.
GM...Small Craft Advisory for winds until 7 AM CDT Thursday for
GMZ130-132-135.
Small Craft Advisory until 7 AM CDT Thursday for GMZ150-155-170-
175.
&&
$$
This product is also available on the web at:
HTTP://WEATHER.GOV/RGV
62
Area Forecast Discussion
National Weather Service Columbia SC
1052 PM EDT Wed May 2 2018
.SYNOPSIS...
High pressure will dominate through the end of the week with
dry weather and rising temperatures. A frontal system will move
into the area over the weekend bringing a chance of showers and
a slight chance of thunderstorms.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
Surface high pressure centered off the Southeast Coast will
continue to provide dry weather through the overnight period.
Light south/southwesterly winds overnight. There may be enough
of a low-level moisture increase for a period of late night
stratus or fog in the southeast section of the area. Overnight
low temperatures are forecast in the mid 50s.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/...
Warm and dry weather will persist Thursday and Friday with the
area under the influence of an upper level ridge. Surface high
pressure will remain centered offshore with southerly flow
bringing increasing moisture into the forecast area. A lack of
deeper moisture and general subsidence beneath the ridge should
support mostly clear skies during this period. However, there
could be some patchy stratus that develops late Friday night as
moisture becomes trapped beneath the inversion, especially over
southern portions of the area.
Temperatures this period will be above normal with highs in the
upper 80s to around 90 degrees and lows in the upper 50s to
lower 60s.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
High pressure will break down on Saturday as a long-wave trough
approaches from the west. The deepest moisture will remain west
of the area associated with a cold front, so the area should
remain mostly dry. Showers could move into northern portions of
the forecast area Saturday night, but precipitation will be
limited. Moisture will also increase along the coast and could
bring a few showers to eastern areas, but confidence is low as
to how for inland this will push. The front will move offshore
on Sunday but the upper trough will remain over the eastern half
of the country. There are a lot of detail differences among the
models from this point forward concerning individual
shortwaves, but the latest GFS and Canadian both show Monday and
Monday night as being the best time for showers and
thunderstorms as the trough axis crosses the area. Broad
troughing is expected to persist through midweek, so occasional
showers will also continue through Wednesday.
The unsettled weather will bring cloudy conditions which will be
the biggest factor in determining daily temperatures. Highs will
remain above normal on Saturday, and temperatures will slowly
cool to near normal by Tuesday. On Tuesday and Wednesday, highs
will be in the upper 70s to lower 80s, with lows in the mid to
upper 50s.
&&
.AVIATION /03Z THURSDAY THROUGH MONDAY/...
Patchy fog/low clouds possible 06Z-12Z...otherwise high
confidence for VFR conditions through Thursday evening.
A southerly wind flow created by a ridge of high pressure
centered offshore will lead to a gradual increase in low-level
moisture overnight. Boundary layer wind out of the southeast
tonight combined with nocturnal cooling, may lead to fog or
stratus, mainly for the fog-prone sites of AGS and OGB late
tonight into early Thursday morning. The NARRE model and SREF
probabilities as well as the HRRR and RAP models indicated IFR
cig/vsbys across the Low Country of SC into the Lower Savannah
River Area. Based on persistence and climatology, will indicate
IFR conditions at AGS and OGB 08Z-12Z. Near calm wind overnight
will become southwest less than 10 knots after 15Z. Could see a
few clouds with bases around 5000 feet during the afternoon.
.EXTENDED AVIATION OUTLOOK...
Increasing low-level moisture expected to provide increasing
chances of late night and early morning fog and low clouds
through Saturday. There is a chance of showers or possibly
thunderstorms with associated restrictions Saturday night
through Monday.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
GA...None.
SC...None.
&&
$$
Area Forecast Discussion
National Weather Service Cleveland OH
1120 PM EDT Wed May 2 2018
.SYNOPSIS...
High pressure over the SERN states will move off the SE coast
tonight. This will allow a cold front to push SE across the
forecast area Thursday night into Friday. Occasional showers and
thunderstorms expected tonight through Friday.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
Previous forecast thinking remains on track. Main adjustments
with this update reflect higher cat pops over the next couple of
hours, with high confidence in hi-res guidance placement of
convection through 06Z. Still think the severe threat remains
minimal over the area, with conditions rapidly stabilizing and
deep layer shear weakening as well. However, some well developed
multicell clusters still remain across northern IN, with a small
corridor of MLCAPE near 1000 j/kg nosing into northwest OH over
the next few hours, some gusty winds cannot be ruled out heading
into the overnight.
Previous discussion...
Still monitoring convection across northwest Indiana that is
tracking toward northwest Ohio. Hi-res guidance a bit
inconsistent with evolution of upstream storms, however the last
several runs of the HRRR brings a multicell cluster eastward
into northwest Ohio before weakening across northern Ohio into
the overnight hours. This makes sense given a sharp drop off of
instability and shear from west to east across northern Ohio,
with additional weakening of shear/instability expected over the
next couple of hours. Have maintained numerous/scattered
wording for the evening into the overnight. Think there will be
a decent lull in convective activity overnight, generally after
06-08Z across the area, with additional showers/thunderstorms
developing and moving across the area towards and just after
12Z. The latest HRRR seems to be picking up on an MCV
originating out of the convective complex across southeast
NE/northwest MO and advecting it into the southern Great Lakes
by 12Z. Remnant shower and isolated thunderstorm activity
possible with this feature, which would likely need an increase
in pops through the morning hours across the area.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY NIGHT/...
For Thursday into Friday There will be periods of showers and
thunderstorms, but models not in good agreement as to when and where
convection will develop. Best idea is that a wave will move through
tomorrow morning then there will be a lull before another wave
develops over the area Thursday afternoon into the evening hours.
Better chance of convection tomorrow night into Friday. Dew point
in the 60s so plenty of moisture. A ll jet of 40 knots will
develop and 300mb jet moves into the Central Lakes for added lift.
Front finally pushes south on Friday but the timing is still in
doubt.
A cold front will be moving through the forecast area on Friday.
Showers and a few thunderstorms should be ongoing during the morning
hours in advance of the front. The NAM and GFS differ slightly on
the timing with the NAM being the faster of the two models. Showers
will end from the west to east as the front moves across the region.
With the model difference, I will be more inclined to hold onto the
shower and thunderstorm threat through most of the day with the
exception of NW OH. The timing of the front may limit the severe
weather threat on Friday. However SPC has the region in a marginal
risk for severe thunderstorms and a possibility of a few stray severe
thunderstorms remains possible particulary for the eastern areas.
Sun and instability will likely play a key role in the severe
thunderstorm threat.
The models continue to differ for Friday night into Saturday. The
NAM quickly moves the front across the forecast area. The GFS on
the other hand is slower and shows a surface wave over central ohio
Friday night. This wave has the potential to keep a few showers
over the southern counties and parts of Northeast Ohio through
through midnight Saturday. High pressure will quickly build on
Saturday morning bringing an end to the precipitation.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
A boundary will dip down from the upper lakes on Sunday driven by a
northern plains shortwave. This feature is fairly weak and
unresolved in the models which show timing differences. This in
combination with northwest flow aloft will support some scattered
rain showers. The boundary will also shift winds to the north, so
have had to pull temps down into the 50s along the lakeshore. Inland
highs could reach upper 60s if cloud cover isn`t more widespread
than current thinking. The boundary will be slow to sink south so
could still see some isolated to scattered showers Sunday night. The
rain will clear from north to south as high pressure builds in from
the north. High pressure takes command Monday and lasts through
Wednesday. Temperatures will be in the 70s with lows in the 40s with
gradual warming through mid week.
&&
.AVIATION /00Z Thursday THROUGH Monday/...
Focus for this TAF period is convection across the region and
TSRA chances at terminals. Focus will be on upstream convection
currently across northern Indiana moving into northern Ohio
later tonight. Best chances for TSRA at this point at KTOL and
to a lesser extent and KFDY, with mention of TSRA prevailing or
TEMPO. Not confident enough in TSRA potential at this point for
other sites, so will keep TSRA potential to a VCTS/PROB30
mention. Another round of precip and MVFR ceilings possible
around/after 12Z as more convection moves across the region.
Winds will generally remain out of the southwest through the
period.
OUTLOOK...Non-VFR possible Thursday night through Friday in
showers/thunderstorms.
&&
.MARINE...
A moderate southwest flow will continue this evening over Lake Erie
as a ridge of high pressure shifts to the east. Winds should taper
below 20 knots after sunset. I will maintain the small craft
advisory until 10pm. An area of low pressure will move just north of
Lake Erie on Friday sweeping a cold front across the lake. Winds
will shift to the west Friday evening. A weak area of high pressure
will build on Saturday creating a somewhat light and variable flow
that will likely be dictated by local effects and a lake breeze on
the nearshore waters. The flow will become southwest again on
Saturday Night as another weak front front approaches. This front
will move across Lake Erie shifting the winds to the north and then
northeast on Sunday night. High pressure will build on Monday and
Tuesday keeping a light northeast flow over the lake for the early
part of next week.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...None.
PA...None.
MARINE...None.
&&
$$
SYNOPSIS...DJB
NEAR TERM...Greenawalt
SHORT TERM...DJB/Garnet
LONG TERM...Garnet
AVIATION...Greenawalt
MARINE...Garnet
Area Forecast Discussion
National Weather Service Austin/San Antonio TX
1000 PM CDT Wed May 2 2018
.UPDATE... /MINOR CHANGES TO POP & WX/
In the absence of a cap breaking focusing mechanism east of I-35
will drop the weather category to showers through tonight. Also
delayed the high PoP category for near I-35 to beyond 06Z as
successive runs of the HRRR have been good with consistency on a
complex developing over the western Hill Country and spreading east
to approach the I-35 corridor after 09Z. Based on the trends around
12Z, another overnight update may be necessary to increase the PoPs
early in the 2nd period over the Southeastern counties. Would prefer
not to change this until we have a chance to look at more 00Z
deterministic model data.
&&
.PREV DISCUSSION... /ISSUED 639 PM CDT Wed May 2 2018/
AVIATION...
All airports will be VFR with strong, gusty southeasterly winds
through the middle of the evening. Ceilings will lower MVFR and IFR
in Austin and San Antonio later this evening through the overnight.
Ceilings will increase to MVFR by late morning Thursday. There will
be a chance for showers and thunderstorms Thursday afternoon, but
probability is still low.
At DRT, some thunderstorms may develop this evening over the
mountains in Mexico and move into Texas. Any storms could bring
strong, gusty winds. Later in the evening ceiling will drop to MVFR
and remain there through the end of the period.
PREV DISCUSSION... /ISSUED 452 PM CDT Wed May 2 2018/
UPDATE...
The Storm Prediction Center has issued a Severe Thunderstorm Watch
for much of West Texas including Val Verde and Edwards County in
South Central Texas. There has already been two severe storms across
Terrell County this afternoon, just west of Val Verde County. The
HRRR, in addition the ARW and Texas Tech WRF show isolated strong
storms around Val Verde and Edwards County through the evening hours,
eventually becoming more liner to the north of the area towards San
Angelo. The HRRR and Texas Tech WRF also hint at a few Serranias del
Burro storms developing between 6pm and 9pm and moving northeast
towards the Rio Grande. We will continue to monitor radar trends, and
if some Serranias del Burro storms do develop and start to head
towards Kinney and Maverick Counties the Severe Thunderstorm Watch
may be expanded in spatial coverage.
PREV DISCUSSION... /ISSUED 248 PM CDT Wed May 2 2018/
SHORT TERM (Tonight through Thursday Night)...
The main forecast issue in the short term is the evolution of
convection across the western half of the area. The approach of the
first shortwave trough and dryline should initiate convection by 00Z
over the Serranias del Burro mountains or maybe as far northeast as
the Sanderson area. CAMs vary on the progression of storms after
that, but the bulk of the solutions have isolated severe supercells
over Val Verde and Edwards counties and just to the north, then cold
pools merging into a weak MCS progressing east to the I-35 corridor
by 12Z. That`s a plausible scenario based on climatology, especially
with the diurnal strengthening of the LLJ. If that happens, the
severe threat should be limited to the supercellular period late this
evening, and mainly in the far west for large hail and damaging
winds. Thursday would have morning storms for many areas, and only
recovery for another round of convection in the far west Thursday
afternoon. On the other hand, if the storms fail to initiate this
evening, or fail to form the MCS, then most of South Central Texas
would be primed for a greater chance of severe storms on Thursday.
Rainfall will be spotty and range from areas in coastal plains
receiving no rain at all, to maybe a few spots receiving up to two
inches in the Edwards Plateau.
LONG TERM (Friday through Wednesday)...
The situation for Friday into early Saturday is less complicated, as
the longwave upper trough ejects across Texas and drags a cold front
through our area. The net result will be a moist adiabatic profile,
deep warm cloud depth (i.e., above -10C), and slow-moving and/or
training of cells from west to east across the area. This should
result in widespread one to two inch rain amounts, with a few spots
in the Edwards Plateau possibly receiving up to four inches for the
entire three-day period.
High pressure will end the rain and bring clearing on Saturday,
followed by an extended period of dry weather and near normal
temperatures through the end of next week, as zonal flow occurs over
most of the CONUS.
&&
.PRELIMINARY POINT TEMPS/POPS...
Austin Camp Mabry 72 85 70 79 61 / 40 40 50 80 70
Austin Bergstrom Intl Airport 73 85 70 79 61 / 40 30 40 70 70
New Braunfels Muni Airport 72 86 70 81 62 / 30 30 40 70 70
Burnet Muni Airport 70 83 67 74 57 / 60 50 60 80 60
Del Rio Intl Airport 73 91 71 81 63 / 60 30 60 70 60
Georgetown Muni Airport 71 84 68 77 59 / 50 40 60 80 60
Hondo Muni Airport 73 87 71 80 62 / 30 30 50 70 70
San Marcos Muni Airport 72 86 70 80 61 / 30 30 40 70 70
La Grange - Fayette Regional 73 86 71 83 63 / 20 20 30 60 60
San Antonio Intl Airport 73 86 71 80 63 / 30 30 40 70 70
Stinson Muni Airport 73 86 72 81 64 / 20 30 40 70 60
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
Mesoscale/Aviation...05
Synoptic/Grids...Oaks
Area Forecast Discussion
National Weather Service Grand Forks ND
946 PM CDT Wed May 2 2018
.UPDATE...
Issued at 946 PM CDT Wed May 2 2018
The showers continue to fade away, just lingering now in the
Bemidji and Lake Itasca areas. There may also be a few sprinkles
back through the Detroit Lakes and Fargo-Moorhead areas. Think
this will taper off in the next hour or so. Clearing is spreading
into northeast ND and the northwest corner of MN, with some fog
being reported at Hallock. Not too confident on much fog, so will
continue to watch that for now.
&&
.SHORT TERM...(This evening through Thursday)
Issued at 324 PM CDT Wed May 2 2018
Precip chances will be the main issue for the period.
Weak shortwave trough moving through ND this afternoon with a
surface trough/wind shift currently pushing towards our far
western counties. There has been some fairly vigorous showers and
some thunderstorms entering our western counties, with the SPC
meso page showing CAPE values around 100-500 J/kg. The HRRR has
been doing a fairly decent job of capturing the current activity,
and it has some decent showers and storms entering the northern
Red River Valley in the next few hours, eventually weakening later
this evening as it moves into northwest MN. Followed this general
trend, keeping most of the mention as showers and isolated
thunder. Winds could become gusty near the showers as we get some
good mixing this evening, but the main issue will be lightning
and brief downpours of up to 0.10 inch.
The surface trough axis moves the rest of the way through the CWA
tonight, with weak cold air advection behind it. The HRRR has
shower activity further south along the boundary later tonight,
but think we will lose a lot of punch after sunset so kept it dry
for now. With clearing skies the northwestern counties should get
down into the 30s even with some mixing going on overnight, with
40s further south and east. Tomorrow, the main upper system will
be well to our south, and the northern branch shortwave up over
Canada. With weak surface troughing to our north winds will shift
to the west and warm air advection will kick in. Think we should
get a few degrees warmer than today, with eastern ND getting
into the low 70s. With strong mixing afternoon relative humidity
values will be in the 20s and 30s. Winds will be a little breezy
at around 15 kts, but at this point think they will be low enough
not to cause too many fire weather issues.
.LONG TERM...(Thursday night through Wednesday)
Issued at 324 PM CDT Wed May 2 2018
A dry cold front or more aptly, a wind shift line, moves through the
area from the north Thu night and the dry air left in its wake will
allow for efficient mixing during the day on Fri. We would look for
high temps Fri aftn most spots to be in the low to mid 70s.
Indications are that NW winds might not be as robust (previous model
inconsistencies regarding wind speeds have been ameliorated) as
previously indicated, but dry fuels and RHs dipping toward 25
percent will make it prudent to monitor the potential for critical
fire weather conditions.
A weak low pressure system rides along a baroclinic zone draped
northwest to southeast across North Dakota Fri overnight into early
Sat providing the chance for a quick passing shower or thunderstorm
followed by a cloudier and cooler Sat aftn. Sun now looks to stay
cool but sunny. A warming trend develops early next week as upper
level ridging will promote return southerly flow. There remains
uncertainty with precipitation chances early next week as long range
guidance differs in handling one or more mid level cyclones exiting
from the Pacific Northwest within weak flow aloft.
&&
.AVIATION...(For the 00Z TAFS through 00Z Thursday evening)
Issued at 652 PM CDT Wed May 2 2018
The shower activity will continue to affect KTVF for another hour
or so, and may yet glance KBJI. However, ceilings have all been in
the VFR range, and the pcpn minimal. Only other thing to watch
this evening is some gustier winds west of the Red River Valley.
These will likely affect KDVL into the evening, but probably not
so much for the other TAF sites. Winds will become light
overnight, then more westerly on Thursday.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...None.
MN...None.
&&
$$
UPDATE...Godon
SHORT TERM...JR
LONG TERM...WJB
AVIATION...Godon
Area Forecast Discussion...UPDATED
National Weather Service Jackson MS
835 PM CDT Wed May 2 2018
.UPDATE...
Updated for evening discussion.
&&
.DISCUSSION...
Satellite imagery showing some remnant cumulus skirting over the
far western periphery of the forecast area this evening. Otherwise,
skies were mostly clear as temperatures have fallen off into the
70s with diminishing winds, at least over the east.
The HRRR still wants to bring in some stratus after midnight over
western sections which seems reasonable given the boundary layer
moisture profile and espected isentropic ascent. Better boundary
layer decoupling over southeast portions with a somewhat drier
boundary layer may support better low level cooling and some
potential for fog formation. The HRRR is showing this, but seems
to keep it patchy at best./26/
Prior discussion below:
.Tonight and Thursday...Upper and surface ridging will continue to
prevail across the area through Thursday, with the very warm
conditions continuing. For tonight, lows will stay warm once again
with lows falling into the low to mid 60s. Hi-Res models suggest
there could be some patchy fog over the southeast early on
Thursday, before burning off by mid-morning. Skies will become
partly cloudy Thursday afternoon with high temperatures climbing
up into the mid/upper 80s once again. The winds will become breezy
out of the south Thursday afternoon with gusts from 20-25kts
possible, especially across the delta. /15/
Thursday night through Wednesday...
An overall quiet pattern will persist across the ArkLaMiss with the
main chances for scattered showers and thunderstorms on Saturday.
The period will start off Thursday night with a shortwave trough
becoming increasingly sheared across the Midwest and Great Lakes
region. An associated trailing cold front is progged to be draped
from northeast to southwest from Illinois to central Texas by
Friday morning. This front will slowly push through the area on
Saturday, however the best forcing and upper level support will be
displaced well northeast of the region so only scattered showers
and thunderstorms are expected. Weak lapse rates and marginal
instability and will greatly preclude any severe weather potential
but an isolated strong storm with sub-severe wind gusts cannot be
entirely ruled out. The front is expected to wash out and won`t
completely remove moisture from the area with low 60s dewpoints
lingering into early next week so a few diurnally driven showers
are possible each afternoon but overall coverage will be low.
Persistent northwest flow between the East Coast trough and West
Coast ridge will help send a reinforcing cold front through the
area around the middle of next week, but this frontal passage
should remain mostly dry. In terms of temperatures, expect
daytime highs to generally range in the low 80s with the exception
being on Saturday when cloud cover will help keep temps a few
degrees cooler and overnight lows in the low 60s to upper 50s.
/TW/
&&
.AVIATION...
00Z TAF discussion:
Mostly VFR conditions will prevail across the region through the
period. However, MVFR/IFR conditions will be seen at HBG between
03/10Z and 03/14Z as fog and low clouds spread into that vicinity.
Winds will generally be from the south and southeast around 10
knots with gusts around 20 knots by afternoon Thursday./26/
&&
.PRELIMINARY POINT TEMPS/POPS...
Jackson 63 87 64 84 / 0 0 2 10
Meridian 60 89 62 86 / 0 0 2 4
Vicksburg 65 87 66 83 / 0 0 3 11
Hattiesburg 62 87 63 87 / 4 1 6 4
Natchez 66 87 65 83 / 3 0 3 9
Greenville 66 87 68 82 / 0 1 4 20
Greenwood 65 87 66 83 / 0 0 3 15
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...None.
LA...None.
AR...None.
&&
$$
Area Forecast Discussion
National Weather Service Jacksonville FL
841 PM EDT Wed May 2 2018
.UPDATE...Easterly winds gradually decreasing this evening with a
dry capped airmass in place. HRRR and SREF models showing some
fog potential late tonight over inland se Ga where fog developed
early this morning. Temperatures tonight will fall into the
mid/upper 50s inland and low/mid 60s coast.
&&
.AVIATION...VFR conditions will continue tonight and Thursday.
&&
.MARINE...Surface ridge axis just north of the waters will
maintain easterly winds over the waters at 10 to 15 knots tonight
with seas in 3 to 5 foot range.
Rip Currents: Moderate risk.
&&
.PRELIMINARY POINT TEMPS/POPS...
AMG 56 84 60 88 / 0 0 0 0
SSI 65 74 66 78 / 0 0 0 0
JAX 61 80 63 84 / 0 0 0 0
SGJ 64 77 66 80 / 0 0 0 0
GNV 58 83 62 88 / 0 0 0 0
OCF 57 84 63 88 / 0 0 0 0
&&
.JAX WATCHES/WARNINGS/ADVISORIES...
FL...None.
GA...None.
AM...None.
&&
$$
Zibura/Peterson/McGinnis
Area Forecast Discussion...UPDATED
National Weather Service Memphis TN
1015 PM CDT Wed May 2 2018
.UPDATE...
Southern plains regional radar mosaic showed a linear convective
complex lifting east into the eastern half of OK. These storms
formed earlier along the dryline, but have since become fed by an
by 40 to 50 knot low level jet as they moved further east.
The low level jet will weaken with eastward extent overnight,
deeper into a midlevel ridge. In addition, NAM 925mb dewpoint
prog depicted dry air lifting north through the lower MS River
valley overnight. Recent runs of the RAP and HRRR models depict
storms edging into northeast AR, the MO bootheel and northwest TN
toward morning, likely diminishing in coverage with time.
PWB
&&
.PREV DISCUSSION... /issued 702 PM CDT Wed May 2 2018/
UPDATE...
Updated to include 00Z Aviation Discussion.
PREV DISCUSSION... /issued 322 PM CDT Wed May 2 2018/
DISCUSSION...
An upper level ridge of high pressure remains over the Mid South
and will keep mainly dry weather in place through most of tonight.
There will be the chance for a few isolated showers and
thunderstorms across far northeast Arkansas prior to sunrise with
decaying convection advancing east from the Plains this evening.
This activity may linger into early Thursday morning but should
diminish. Temperatures should remain mild tonight with most areas
remaining in the 60s, with highs again tomorrow reaching into the
lower 80s northwest to upper 80s southeast.
A potent upper level low pressure near the four corners region
this afternoon will lift out to the northeast and weaken through
tomorrow evening. As this occurs, additional convection should
develop by Thursday afternoon over the Ozarks and may spread into
northwest portions of the Mid South through Thursday night. A few
stronger storms will be possible, but the overall threat for
severe weather appears low as the upper trough shears out and
lapse rates remain modest. This convective activity should stall
and diminish to scattered coverage on Friday as the upper trough
lifts out to the northeast. Temperatures will be a few degrees
cooler for Friday, but still slightly above seasonal normals, in
the lower 80s.
Another stronger upper trough and attendant cold front will move
through the Mid South Friday night and Saturday. This will likely
result in another round of showers and thunderstorms. A few strong
storms will be possible during this period, especially across
northeast Mississippi on Saturday.
Surface high pressure briefly builds over the region for Sunday
before another shortwave trough in northwest flow aloft swings a
weak cold front through Sunday night into Monday. Isolated showers
and thunderstorms will be possible with the frontal passage, but
overall most locations will remain dry as moisture is limited.
Dry and seasonable weather will filter into the area behind the
front for Monday night through Wednesday of next week.
JLH
&&
.AVIATION...
00Z TAF set
VFR conditions expected for the next 24 to 30 hours. Mainly rain
free conditions expected tonight at MEM,MKL, and TUP. Weakening
upstream showers and thunderstorms may result in a few rain
showers and perhaps thunderstorms at JBR mainly from late morning
into Thursday afternoon. South winds will average between 10-15
kts with a few higher gusts at times.
CJC
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...None.
MO...None.
MS...None.
TN...None.
&&
$$
Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
1025 PM CDT Wed May 2 2018
.UPDATE...
Issued at 1025 PM CDT Wed May 2 2018
Updated to include 06Z aviation discussion below.
&&
.SHORT TERM...(This afternoon through Thursday)
Issued at 1157 AM CDT Wed May 2 2018
The surface cold front which pushed through the region yesterday
will remain stalled just to the south and east of the WFO MPX
coverage area through midday tomorrow. Meanwhile, a rotating upper
level low over the far southwestern CONUS will track northeast to
northwestern IA by late day tomorrow. This will help drag not only
a developing area of surface low pressure northeastward along the
front but also additional GOMEX moisture into the region. Tranquil
conditions are expected the rest of today through tonight and the
first half of tomorrow with winds going light/variable and cloud
cover steadily increasing. Will again look for late afternoon to
early evening showers/t-storms develop for far southern and
eastern MN into western WI. Just general thunderstorms are
expected though a rogue stronger thunderstorm close to the Iowa
border cannot be ruled out. Temperatures will run slightly higher
on Thursday than today, with highs climbing into the upper 60s to
lower 70s for most of the coverage area.
.LONG TERM...(Thursday night through Wednesday)
Issued at 337 PM CDT Wed May 2 2018
Thursday night through Saturday night...The aforementioned stalled
front will finally be kicked away to the southeast as the upper
level trough also pulls into eastern NOAM. This will bring an end
to the periodic showers/thunderstorms experienced over the past
few days across the WFO MPX coverage area. Weak high pressure with
drier northwest flow aloft will take hold over the area Friday
through Saturday morning. A weak low pressure center will then
arrive from the west late day Saturday, aligned with modest
Pacific moisture, to potentially produce isolated to scattered
showers and thunderstorms late Saturday through Saturday night. No
strong storms or even high amounts of QPF are expected (generally
0.25" or less of rain). The main impact of this combination of
features will be a noticeable jump in temperatures, nearly 10
degrees higher than earlier in the week. Highs on Friday and
Saturday will span the 70s across the area.
Sunday through Wednesday...A more tranquil period of weather is
expected for the start of the week as cooler high pressure drops
in from Canada. This will result in precip-free weather for Sunday
through most of Tuesday with highs running in the mid 60s to lower
70s. A more unsettled and uncertain pattern looks to take shape
for the middle of next week but nothing strong is looming per the
GFS/ECMWF. Have maintained generally chance-range probabilities
for precipitation for Wednesday. Highs will continue to run close
to normal.
&&
.AVIATION...(For the 06Z TAFS through 06Z Thursday night)
Issued at 1025 PM CDT Wed May 2 2018
Thinking remains similar to 00Z issuance, with some mid/high
clouds overnight, then the possibility of some lower clouds and
SHRA/TSRA Thursday afternoon/evening as another surface wave moves
northeast along the frontal boundary to our south. However, the
latest guidance from the RAP and NAM suggest this activity may
stay south of the forecast sites, so if anything things appear a
bit more optimistic. Didn`t make any significant changes to the
going forecast, and kept some VCSH in for the more
southern/southeastern locations.
KMSP...Main uncertainty is with chances for precipitation Thursday
afternoon. If anything it is now looking a bit less likely, so
removed the VCTS that was previously mentioned and only included
VCSH.
/OUTLOOK FOR KMSP/
Friday...VFR. Northwest wind 5 to 10 kt.
Friday night...VFR. Variable wind less than 5 kt.
Saturday...VFR. Southeast wind around 10 kt becoming southwest.
Saturday night...VFR. West wind around 10 kt becoming northeast.
Sunday...VFR. Northeast wind 5 to 10 kt.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
&&
$$
UPDATE...
SHORT TERM...JPC
LONG TERM...JPC
AVIATION...
Area Forecast Discussion
National Weather Service Norman OK
1058 PM CDT Wed May 2 2018
.AVIATION...
Most of the convection that formed this afternoon and evening
has moved east of all TAF sites at 4Z. Strong wake low winds
across north central Oklahoma will diminish by 6z. VFR ceilings
at 4Z should lower to MVFR overnight with breezy southeast winds.
Meanwhile, additional storms have formed across southwest Texas
this evening. At least scattered thunderstorms should move across
SPS/LAW/OUN/OKC from roughly 6Z through 12-13Z.
&&
.PREV DISCUSSION... /issued 709 PM CDT Wed May 2 2018/
AVIATION...
A line of strong to severe storms will move across most terminal
sites between 00z and 4z. The stronger storms may lower visibility
to around 1sm with mainly MVFR ceilings. More storms may develop
and move across the southern half of Oklahoma and western north
Texas mainly between 6z and 12z. After 12-13Z, mainly VFR
conditions are expected with a south to southwest wind.
PREV DISCUSSION... /issued 210 PM CDT Wed May 2 2018/
DISCUSSION...
Latest surface observations and satellite show enhanced cumulus
and some glaciation along a sharpening dryline now across the
eastern Texas Panhandle. Deeper convection has been ongoing for an
hour or so further north, near a weak surface front across the far
northern Texas Panhandle into the Oklahoma Panhandle. NSSL mobile
sounding at Elk City from 18z shows a weak capping EML and this
should continue to errode as forcing for ascent increases from
approaching deep closed low and embedded minor shortwave trough.
Latest RAP mesoanalysis shows moderate to strong instability has
already developed across western Oklahoma and western north Texas
with MLCAPE as high as 3,000 J/kg and effective shear of 50-60
knots. This parameter space, along with nearly perpendicular shear
vectors to the sharpening dryline, is more than favorable for
supercells. Other concerns include climatologically low LCL
heights. One mitigating factor to a potentially higher-end tornado
threat will be somewhat weak low level shear. Our bigger tornado
events tend to have larger 0-1km bulk shear and SRH values.
Nevertheless, 15-20 kt 0-1km shear and low LCLs with the
aforementioned parameter space is concerning and tornadoes,
including a few significant tornadoes are possible given the
proper storm evolution. Some cold pool expansion and resulting
consolidation may occur with the ongoing convection across
northeast Texas Panhandle and the Oklahoma Panhandle. This could
evolve into a cluster or line of convection that posses mainly a
damaging wind threat later in the evening across northern
Oklahoma. This evolution is uncertain at the moment and we`ll
continue to monitor trends.
Suite of CAMs have varied some from run to run and model to
model. The spectrum of solutions generally supports the above
thinking, and we`ll continue to watch the trends in observations
through the late afternoon and evening and add more detail to the
forecast when we can.
Regardless of how early on more discrete supercells evolve, some
tornado threat will persist into the night given such a moist
boundary layer with only modest stabilization. The threat could
persist into the early morning hours and some localized flooding
could occur particularly across eastern and southern sections of
the area once shear vectors become a little more parallel to a
potential cluster or line of convection. Depending on the extent
of convection and magnitude/breadth of convective overturning,
some thunderstorm threat and severe potential will persist across
roughly the southeast half of the area into tomorrow afternoon.
The rest of the forecast is relatively unchanged. Northwesterly
flow will gradually back and become more zonal with at least one
or two minor shortwaves resulting in convection by early next
week.
BRB
FIRE WEATHER...
Elevated fire weather conditions could occur tomorrow afternoon
across far western Oklahoma and portions of north Texas. Greenup
may limit the threat of significant spread however. ERC-G values
are on the high end of normal currently.
BRB
&&
.PRELIMINARY POINT TEMPS/POPS...
Oklahoma City OK 68 83 56 75 / 80 30 10 0
Hobart OK 66 86 55 77 / 50 20 0 0
Wichita Falls TX 69 86 60 75 / 70 40 10 10
Gage OK 61 81 50 76 / 20 0 0 0
Ponca City OK 69 85 54 75 / 50 30 10 0
Durant OK 70 78 66 73 / 60 70 40 30
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...None.
TX...None.
&&
$$
Area Forecast Discussion
National Weather Service Pueblo CO
752 PM MDT Wed May 2 2018
.UPDATE...
Issued at 750 PM MDT Wed May 2 2018
Updated for expiration of the Red Flag Warning.
UPDATE Issued at 714 PM MDT Wed May 2 2018
Updated forecast grids for issuance of a Winter Weather Advisory
for zones 58 and 60, the higher mts of Lake and Chaffee Counties.
Incorporated latest obs data. Was going to cancel the Red Flag for
the southeast corner, but obs in that area are currently showing
red Flag conditions, so another update is expected in the next
hour. Moore
&&
.SHORT TERM...(This evening through Thursday)
Issued at 255 PM MDT Wed May 2 2018
A Red Flag Warning remains in effect for eastern Las Animas and Baca
counties. As of 2 PM the gusty winds have not yet developed and
therefore the humidities are still relatively high. The HRRR is
still forecasting the increasing in the wind speeds shortly, and
observations just to the south and west of the Warning area are
showing the gusty winds and low humidities. Thus, will keep the
Warning in effect thru 8 PM.
Showers and a few thunderstorms were occurring from the I-25
corridor area and westward early this afternoon, with some snow at
the higher elevations. Satellite image this afternoon show an upper
low center over northwest AZ. This low is expected to move east-
northeast tonight and Thu, and will move acrs CO. There will
continue to be some showers and thunderstorms acrs southern CO this
evening, but by late tonight, the NAM shows a decrease in the
activity. The ending time of the Winter Wx Advisory at 06Z still
looks ok. One concern is that the HRRR is a little different from
the other models in the potential for precip late tonight over the
Pikes Peak area, El Paso and Pueblo counties and into Crowley
county. The HRRR brings another round of showers/tstms to that area
from about 06Z thru 09Z, although it could last a bit longer over El
Paso county. Will lean toward the HRRR solution and will go with
high precip chances in these areas late tonight.
With the upper low moving into northern KS and NE by Thu afternoon,
it looks like the best chances for precip behind this system, will
be over the northern half of CO, but this includes Lake and portions
of Chaffee county, and Teller and northern El Paso counties. The
southern mtns, the San Luis Valley and areas along the I-25 corridor
will probably see some precip chance on Thu, with the potential for
thunderstorms, especially in the afternoon hours. Temps on Thu will
be below average.
.LONG TERM...(Thursday night through Wednesday)
Issued at 255 PM MDT Wed May 2 2018
Thursday night...The upper trough axis is forecast to be exiting the
state Thu night, with brisk northerly winds as well as mountain
shower activity gradually decreasing through the evening hours. Min
temps will drop to around 30F for the high valleys, and mid 30s to
around 40F for the plains.
Friday through Sunday...An upper ridge of high pressure slowly moves
eastward across the Four Corners region over the weekend. Models are
still indicating diurnal mt convection each day though QPF amounts
remain light and POPs will be isolated to low-end scattered at
times. Fri is expected to be the coolest day of the extended period,
with highs in the 60s for the high valleys and mid 60s to mid 70s
for the plains. Temps warm up for Sat and Sun however, with highs
around 70F for the high valleys, and mid 70s to mid 80s for the
plains.
Monday through Wednesday...Another upper disturbance is expected to
cross the Pacific NW and the Rockies through the beginning of the
next work week, though it should stay mainly north of Colorado.
There is a slightly better shot of pcpn across all of the forecast
area, and not just the mts, but temps at this time still look to
remain warm. Look for maximum temps around 70F for the high valleys,
and lower 70s to lower 80s for the plains. Moore
&&
.AVIATION...(For the 00Z TAFS through 00Z Thursday evening)
Issued at 255 PM MDT Wed May 2 2018
Showers and thunderstorms will be possible at KCOS, KPUB and KALS
this evening. There is the possibility that showers and storms
could continue past midnight at KCOS and KPUB. It looks like low
stratus will be problem in the KCOS area after 06Z tonight, and into
early Thu morning. Precip in the vicinity of KCOS will be possible
thru much of the day Thu.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory until midnight MDT tonight for COZ068.
Winter Weather Advisory until 11 AM MDT Thursday for COZ058-060.
&&
$$
UPDATE...MOORE
SHORT TERM...28
LONG TERM...MOORE
AVIATION...28
Area Forecast Discussion
National Weather Service Sacramento CA
314 PM PDT Wed May 2 2018
.SYNOPSIS...
Isolated showers over the northern Sierra today south of Highway
50...otherwise drier and warmer through the end of the week. A
slight cooling next week with a chance of light showers at times
mainly over the mountains.
&&
.DISCUSSION...
It`s been sunny and generally warmer today as high pressure
ridging builds in. Skies have been clear, except for cumulus
clouds forming over the Sierra. The back end of the upper level
low which triggered a couple strong mountain thunderstorms
yesterday evening is exiting to the south and east of the area.
Before moving out, some afternoon and evening showers are
possible, mainly over the Sierra south of Highway 50. Radar
currently shows some showers beginning to develop in eastern
Amador County. The latest experimental HRRR model run shows most
of the convective activity should be focused over Tuolumne County,
though a few cells may develop over eastern El Dorado and Placer
counties.
Slightly warmer temperatures are expected Thursday and Friday as
the upper ridge axis moves inland. Valley highs are expected to be
in the 80s on Thursday, mid 80s on Friday. Upper ridging shifts
eastward enough by Saturday to allow an upper low over the
Pacific to approach Norcal. Saturday will see increasing cloud
cover and possibly just a little cooling. Isolated showers will
be possible over the northern Coastal Range by evening with enough
instability to potentially produce a couple thunderstorms. The
vast majority of the area will remain dry, though. EK
&&
.EXTENDED DISCUSSION (Sunday THROUGH Wednesday)
Ridge shifts east on Sunday as a series of disturbances move
across the region into midweek. Each wave is weak with best
dynamics likely remaining to the north of California. Therefore
just a small chance of a few showers across far northern portions
of the area (Shasta Co) Sunday and again by Tuesday/Wednesday.
Ridging may briefly build back in briefly in between each wave,
which should bring some warmer temperatures on Monday. A few
valley sites may approach the 90 degree mark.
CEO
&&
.AVIATION...
VFR conditions the next 24 hours at the TAF sites. Light winds
under 10 kts.
&&
.STO WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
Area Forecast Discussion
National Weather Service Las Vegas NV
900 PM PDT Wed May 2 2018
.SYNOPSIS...Isolated showers lingering around southern Nevada will
end dissipate early Thursday morning. Drier conditions and soaring
temperatures are expected Thursday into early next week, with
temperatures in Las Vegas likely to reach the upper 90s by Sunday.
&&
.UPDATE...Recent satellite and radar loops indicated showers moving
down through southern Nye and Lincoln counties early this evening. A
vorticity lobe on the back side of the exiting upper low may be able
to sustain showers as they move into northern and central Clark late
this evening before dissipating a few hours after midnight. The
latest HRRR and ARW models depict this scenario. The Pop/Wx grids
were updated to reflect this trend which may lead some flurries in
the Spring Mountains and some isolated late rain showers or
sprinkles making it primarily into northern parts of the Las Vegas
Valley. Once the shower activity ends, skies will clear early
Thursday morning and the warming trend will begin.
&&
.PREV DISCUSSION...
845 PM PDT Wed May 2 2018
.SHORT TERM...through Thursday night. Upper low was spinning over
far northern AZ early this afternoon and moving very slowly
northeast. As expected, convective clouds had been developing in
sunny areas, but had been shallower than previously thought, with
only one lightning strike in southern Nye County and two in northern
Mohave County as of early afternoon. In the Las Vegas area,
significant rainfall had been confined to the far western edge of
the valley and up into the Spring Mountains. As the low drifts
farther away, upper level temps will gradually warm, shutting off
what`s left of the convection. Given the underperforming trend thus
far, reduced PoPs a bit for the rest of the afternoon and overnight,
and cancelled the Winter Weather Advisory for the Clark County
mountains above 7000 feet. Expect dry weather areawide Thursday,
with temperatures five to 15 degrees warmer than today.
.LONG TERM...Friday through Wednesday.
Ridge of high pressure over the region will lead to well above
normal temperatures Friday and Saturday with readings about 10-15
degrees above normal. An area of low pressure will move inland
across northern California and northern Nevada Sunday, but little
impact from this system will be seen across our forecast area. As
the ridge breaks down Sunday, southwest winds will increase with
most areas seeing speeds generally 15-25 mph with some locally
higher gusts possible. However, we will not see much of a cool down
as this system passes to the north as temperatures are still
expected to remain about 10 degrees above normal for the first half
of next week. Confidence in the models however is fairly low beyond
Tuesday as the EC keeps a fairly strong ridge over the area while
the GFS is much more progressive with another system approaching the
coast by Tuesday and Wednesday. The GFS is showing some light
precipitation reaching the Sierra Tuesday afternoon, but due to the
differences in the models have elected to keep the forecast dry
through the period.
&&
.AVIATION...For McCarran...One last batch of showers moving down
from central Nye and Lincoln counties will brush the KLAS terminal
area accompanied by a northwest wind 6-10 knot near or shortly after
midnight local time with cloud bases generally 8-10 kft. Clouds and
showers will dissipate early Thursday morning leaving light winds
and mostly clear conditions Thursday through Thursday night.
For the rest of southern Nevada, northwest Arizona and southeast
California...Isolated to scattered showers move south at 10-15 knots
over southern Nevada and far northwest Arizona should dissipate
before 12Z Thursday. Skies will clear early Thursday morning with
light winds and VFR conditions across the region through Thursday
night.
&&
.SPOTTER INFORMATION STATEMENT...Spotters are encouraged to report
any significant weather or impacts according to standard operating
procedures.
&&
$$
UPDATE/AVIATION...Adair
SHORT TERM...Morgan
LONG TERM....Gorelow
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