Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 08/11/17
Area Forecast Discussion...UPDATED
National Weather Service Albuquerque NM
738 PM MDT Thu Aug 10 2017
.UPDATE...
We coordinated with SPC and have agreed to drop Severe Thunderstorm
Watch 446 for northeast NM. Zones will be updated shortly. CHJ
&&
.PREV DISCUSSION...545 PM MDT Thu Aug 10 2017...
.AVIATION...
00Z TAF CYCLE
SCT to ISOLD showers and thunderstorms will generally move toward
the east/northeast around 10-20 mph through much of the night.
Storms across the NE will be capable of large hail and damaging winds
with an ISOLD tornado threat. Cells will probably cluster this aftn
and evening, and an organized line of storms will be possible across
the NE. A back door cold front will push southwestward through the E
plains tonight into Friday morning, allowing low clouds with IFR and
MVFR conditions into the NE quarter of the state. Greatest confidence
in TAF site flight category restriction is at LVS Friday morning,
with less confidence at TCC. Storms will increase in coverage on
Friday with locally heavy rain and wet microbursts likely with low
clouds and reduced visibilities. 40
&&
.PREV DISCUSSION...310 PM MDT Thu Aug 10 2017...
.SYNOPSIS...
Showers and thunderstorms will become more widespread and active
Friday and through the weekend before some drying pushes into west
central and northwest New Mexico early to mid next week. A few
strong to severe storms with large hail and damaging wind gusts are
most likely late this afternoon and evening over portions of
northeast New Mexico. Locally heavy rain on Friday, which could
result in flash flooding, may be most likely along portions of the
central mountain chain, Northeast and Central Highlands and the East
Central Plains. High temperatures for the next several days will be
near to below average while overnight lows will be near to above
average.
&&
.DISCUSSION...
Sure doesn`t seem like the monsoon season with the recent bouts of
severe weather and the ongoing SPC outlook, which still has the
marginal/slight risk area painted over Union, and the majority of
Catron and Harding counties through this evening. Sfc front/outflow
boundary forecast to surge into the northeast, but latest HRRR has
delayed it until 00Z or after. This seems reasonable as convective
development just starting to get frisky over ne NM and over se CO.
Given the placement of forecast rainfall and surface gradient, not
suspecting there will be much of an east wind, if any, into the
middle/lower RGV tonight. May have to watch the southeast tonight,
if the boundary is driven farther south because the inherited
minimal to nil pops were left in that region.
The upslope flow associated with the boundary sets the stage for a
more active Friday/Friday night, and potential for heavy rain over
portions of the central mt chain, Northeast and Central Highlands
and East Central Plains, where theta-e values increase significantly.
Severe storms are not in the outlook though. Did up pops to match
the guidance consensus. The far southeast and far northwest may be
the areas which are least likely to receive decent rainfall. Lowered
high temperatures Friday for parts of the northeast, although did
not go as cool as the MET guidance.
Saturday and Sunday look active also with a rather flat H5 ridge in
place. Another front may impact the northeast Sunday night and again
Monday night. Some drier air may push into west central and
northwest New Mexico next Tuesday/Wednesday to trim rain chances
there. High temperatures the next 7 days will be near to below
average, with lows near to above average.
&&
.FIRE WEATHER...
The mid-level high pressure system will migrate southeastward over
south TX today, allowing a more traditional flow of monsoon moisture
to stream north and northeastward over the forecast area. A couple
of moist back door cold fronts area also expected to dive south
southwestward through the eastern plains: one tonight and the other
Sunday night. An uptick in the coverage and wetness of showers and
thunderstorms is expected to begin Friday, with scattered to
numerous showers and thunderstorms expected each afternoon and
evening through Monday. With PWATs in the 1-1.6 inch range on
Friday, that day should be the wettest day overall, and Monday looks
to be a close second if Sunday night`s front comes in wet enough.
With all the moisture and some cool air advection with the fronts,
high temperatures will vary from near normal to several degrees
below normal Friday through Monday. Haines will vary around 3
through this period. There will also be areas of poor ventilation
Friday and Saturday, but probably some improvement Sunday before
vent rates fall again on Monday.
An upper level trough approaching from the west will steer drier air
into the state from the west and southwest Tuesday through the
middle of the coming work week. The coverage and wetness of
convection will decrease with each day, and there will be a
resulting increase in high temperatures. Ventilation will probably
also improve, though some stubborn pockets of poor may linger over
southwest areas. Haines around 5 are expected across northern areas
Tuesday and Wednesday.
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
40
Area Forecast Discussion
National Weather Service Birmingham AL
729 PM CDT Thu Aug 10 2017
.UPDATE...
For 00Z Aviation.
&&
.SHORT TERM...
This afternoon and Tonight.
As expected, the convective activity this afternoon has been
concentrated over western Alabama, along the leading edge of an
MCV, and along the Gulf Coast associated with the sea-breeze. The
HRRR model has had a good handle on the areal coverage but is
lagging in time by several hours. This models has these two areas
coming together into one concentrated mass of convection this
afternoon and tracking eastward across areas mainly along and
south of I-20. Highest pops this evening will be along and east of
I-65, with only a few showers remaining by midnight. Could see
some locally heavy rainfall over the southern counties as the
slower moving seabreeze storms interact with the MCV storms.
58/rose
.LONG TERM...
Friday through Wednesday.
The original weakening surface boundary is expected to be well to
our north on Friday. We should keep weak onshore flow around the
Atlantic ridge/or around weak ridging in the Northeast Gulf over
the weekend. A surface front approaches the Deep South on Friday,
but is not expected to make progress into Alabama over the weekend
as the main low over the Great Lakes pulls off to the east
quickly taking the main energy with it and leaving the approaching
front stalled well to our north. In the upper levels on Friday,
we have a first angled then flattening elongated ridge over the
southern third of the U.S. centered over Texas with W/NW then more
zonal weak flow across C AL. We should continue with a daily
bombardment of disturbances to enhance our convective activity.
By the beginning of next week, an upper trough tries to digs
across Eastern Conus and should help to push a surface ridge
southward across the same area to nudge the stalled front into the
N/NE portions of the CWA as a back door front during the first
half of next week. Some lower temperatures/dew points could drift
into the NE counties by the middle part of next week to round out
the forecast and would lower rain chances in the NE as well.
08
&&
.AVIATION...
00Z TAF Discussion.
Have re-introduced IFR/LIFR mention at the terminals overnight.
Additionally, showers and thunderstorms have developed late this
afternoon and will continue a few hours at minimum this evening.
The low clouds hung around parts of central Alabama until almost
mid day, this delayed the instability realization across the area.
Therefore, showers and thunderstorms are develop and continuing
this evening along these boundaries and what appears to be a
remnant sea breeze. Mentioned thunder at most sites through 03z.
The ceilings/vis will be briefly impacted and may last longer than
mentioned if merging of boundaries takes place.
With southerly flow in the low levels overnight, expect low clouds
to develop after 09z. The IFR/LIFR period appears to be from
around the 09-14z time frame. Heating should bump these clouds to
MVFR by 16-17z and VFR by afternoon. Did not mention any weather
tomorrow after 18z, but thunderstorms much like the previous
several days are expected. fog does not appear to be the main
issue but will monitor the latest developments.
**Note...had some technical issues with the TAF issuance this
evening. The forecast is now out and under corrected. Sorry for
this inconvenience.
75
&&
.FIRE WEATHER...
Above normal rain chances are expected through the weekend. There
are no fire weather concerns.
&&
.PRELIMINARY POINT TEMPS/POPS...
Gadsden 71 87 72 88 71 / 50 60 40 40 40
Anniston 72 86 72 87 72 / 60 60 30 50 30
Birmingham 72 87 74 89 73 / 50 60 30 50 30
Tuscaloosa 73 88 74 91 74 / 30 60 30 50 30
Calera 72 88 73 89 73 / 50 60 30 50 30
Auburn 72 87 73 88 73 / 60 60 30 50 30
Montgomery 74 90 75 91 75 / 60 60 30 50 30
Troy 73 88 73 90 73 / 60 60 20 50 30
&&
.BMX WATCHES/WARNINGS/ADVISORIES/...
None.
&&
$$
Area Forecast Discussion
National Weather Service El Paso Tx/Santa Teresa NM
345 PM MDT Thu Aug 10 2017
.SYNOPSIS...
Isolated to scattered thunderstorms will be most pronounced over
the higher terrain of the Gila Region, Sacramento Mountains, and
New Mexico Bootheel this evening, with a few strays elsewhere.
Thunderstorms may last a little longer into the evening over
Southwest New Mexico as they move north from the Sierra Madres. An
upper level disturbance will move across the area Friday night,
resulting in scattered thunderstorms across the area. Cloud cover
from these storms could linger into Saturday, resulting in cooler
temperatures. The overall pattern is favorable for an uptick in
thunderstorm coverage through the weekend and early next week.
&&
.DISCUSSION...
Water vapor imagery and RAP analysis shows the subtropical ridge
has shifted towards east-central NM, with an inverted trough at
the mid-levels extending from the northern Baja into the northern
Sierra Madre Occidental (SMO). This disturbance is largely
convectively-induced from last night`s very impressive MCS over
Sonora. The disturbance that initially helped trigger that MCS (an
upper-tropospheric inverted trough) is rapidly weakening over
southern Baja, but it`s difficult to find unless you do a water
vapor loop going back to yesterday afternoon. Regardless, the
present inverted trough is having some influence on convection
over the northern SMO which is drifting northwards into the
Bootheel Region.
Otherwise, thunderstorms are generally anchored to the higher
terrain in the San Andres and Sacramento Mountains, and is
strongest over the higher ranges of the Gila. Steering flow is
bringing storms from south to north, while upper level WSW flow is
taking the anvil blowoff to the ENE. This should help to allow
some scattered storms to work into the lower elevations of SW New
Mexico (e.g., Hidalgo and southern Grant Counties) as the storms
to the north and south aren`t spewing cirrus ahead of themselves.
Elsewhere, expect isolated thunderstorms...including parts of El
Paso and Hudspeth Counties where cu is somewhat enhanced.
The mid-level inverted trough will continue to move to the
northwest overnight, but will decoupling from its reflection
higher aloft. NAM/GFS show a strong PV anomaly (strongest at 345K)
making its way around the subtropical ridge and into SE Arizona by
Friday afternoon, and SW New Mexico Friday night. This may help
keep thunderstorms going well into the overnight hours across
much of the area Friday. Kept isolated to scattered PoPs going
through the night, with the best chances west of the Rio Grande.
Leftover clouds/debris will likely impact thunderstorm chances on
Saturday, though the overall pattern continues to favor a relative
uptick in convection, with mid-level moisture continuing to stream
up from Mexico (and maybe even tapping the mid-level moisture
remnants of Franklin or whatever it`s E Pacific name ends up
being assuming it can reorganize at the sfc).
With the risk of enhanced cloud cover/convective debris, I also
dropped the Max Temps for Saturday by a few degrees. High "bust"
potential with this one if we`re left with a mess of clouds Sat
AM.
Sunday...the subtropical ridge weakens and spreads out E-W with
the axis just south of the border. Any weak westerly disturbances
could keep enhancing thunderstorm chances.
Next week, the ridge appears to reorganize and re-center itself
over south Texas, with southerly flow keeping monsoonal moisture
in place over our area.
&&
.AVIATION...Valid 11/00Z-12/00Z...
Mostly VFR conditions thru period with the possibility of MVFR
near thunderstorms. Generally east to southeast winds AOB 12KTS
except gusts to 40KTS possible near thunderstorms. Showers and
thunderstorms will be mostly confined to the area mountains with
some isolated storms mainly west of a KTCS- KDMN line. Skies
generally FEW-SCT070-090 SCT-BKN200-250.
&&
.FIRE WEATHER...
Upper high will be shifting into central TX over the coming days
which will allow deeper monsoon moisture to return to the region.
Expect mainly scattered mountains storms and isolated lowland ones
through Friday but as moisture deepens, storm coverage will
increase over the weekend and into early next week. Temperatures
will also fall to near normal as moisture increases this weekend.
Models now showing little movement in the upper high for the later
half of next week with moisture plume shifting mainly over the
eastern half of the forecast area. Relative humidities through the
period will remain above 20 percent with winds generally less
than 15 mph except near storms.
&&
.PRELIMINARY POINT TEMPS/POPS...
El Paso 76 98 74 94 / 10 0 20 30
Sierra Blanca 70 95 71 92 / 10 0 10 30
Las Cruces 70 95 68 92 / 0 0 30 30
Alamogordo 69 93 68 91 / 10 10 20 40
Cloudcroft 54 73 51 69 / 30 40 30 50
Truth or Consequences 69 94 69 90 / 20 10 30 40
Silver City 63 88 61 83 / 40 50 50 50
Deming 69 96 68 93 / 20 10 40 40
Lordsburg 70 95 68 90 / 30 30 40 40
West El Paso Metro 74 97 72 93 / 10 0 20 30
Dell City 73 98 70 95 / 10 0 10 30
Fort Hancock 76 99 75 95 / 10 0 10 30
Loma Linda 68 91 65 88 / 10 0 20 30
Fabens 75 99 73 95 / 10 0 20 30
Santa Teresa 72 96 71 93 / 10 0 20 30
White Sands HQ 70 95 70 92 / 0 0 20 40
Jornada Range 69 95 70 91 / 10 0 30 40
Hatch 69 96 68 93 / 20 0 30 40
Columbus 71 98 68 93 / 20 0 40 30
Orogrande 72 95 71 92 / 10 0 20 30
Mayhill 58 81 56 78 / 20 30 30 50
Mescalero 58 82 56 78 / 30 40 30 40
Timberon 58 81 55 78 / 30 20 30 40
Winston 60 86 57 82 / 40 40 40 50
Hillsboro 66 92 64 87 / 30 30 40 50
Spaceport 69 95 68 91 / 20 0 30 40
Lake Roberts 59 86 56 82 / 40 50 50 50
Hurley 64 89 62 86 / 30 30 40 50
Cliff 66 94 64 89 / 40 50 50 50
Mule Creek 66 91 63 86 / 40 40 40 50
Faywood 65 91 63 87 / 30 30 40 50
Animas 69 96 67 90 / 40 30 40 40
Hachita 69 96 66 91 / 30 20 40 40
Antelope Wells 68 95 66 88 / 50 20 40 50
Cloverdale 66 91 64 85 / 50 30 40 50
&&
.EPZ WATCHES/WARNINGS/ADVISORIES...
NM...None.
TX...None.
&&
$$
25/26
Area Forecast Discussion...UPDATED
National Weather Service Fort Worth TX
950 PM CDT Thu Aug 10 2017
.UPDATE...
Earlier strong thunderstorms to our northwest have dissipated with
the loss of daytime heating, leaving behind just some additional
high-level cloud cover. Another disturbance pinwheeling around
the northern periphery of the mid-level high is lighting up an
additional area of convection across the Texas Panhandle and
extreme western Oklahoma. This activity will continue to congeal
into an MCS overnight and track steadily southeastward towards the
Red River. Veering low-level flow will act to protect North Texas
from the brunt of this activity as storm-relative convergence is
reduced. That said, it appears an outflow boundary may be able to
slide into the I-20 corridor on Friday morning, where subtle
isentropic upglide may help to spark off a couple showers and a
few thunderstorms. The greatest precipitation coverage (40%) is
still expected to remain across our northeastern counties,
however. Given the aforementioned meager winds and fairly scant
elevated instability, we`ve limited thunderstorm wording to
"isolated" in this update through Friday morning.
A cursory glance at the latest guidance points to the potential
for temperatures warming into the upper 90s to near 100 degrees
across parts of the region as the surface flow becomes more
southwesterly. At this time, it appears that any cloud cover or
precipitation of significance may diminish sufficiently during the
late morning/early afternoon to allow temperatures to realize this
potential in full. Combined with dewpoints in the lower 70s, heat
index values of 105-107 degrees appear possible across Central
Texas and into the Metroplex. We will, however, defer decision on
a two-day heat advisory for the midnight shift as convective
trends/outflow potential becomes a bit more clear.
Carlaw
&&
.AVIATION... /Issued 634 PM CDT Thu Aug 10 2017/
Scattered thunderstorms are ongoing this hour near Wichita Falls
within a zone of very strong heating. This thunderstorm activity
appears to be diurnally-driven, and thus should begin to wane here
over the next few hours, but will continue to cause issues at the
Bowie Cornerpost. We`re also watching a convective segment moving
swiftly into the Oklahoma City Metro. With plentiful instability
to its south, it`s possible this activity manages to slide south
of the Red River later this evening. Recent runs of the
experimental HRRR seem to be handling this ongoing convection the
best, and lends enough confidence to add in a few hours of VCSH
at the Metroplex sites after 05z. That said, recent warming cloud
tops indicate an ongoing weakening trend this hour.
Another complex of storms is expected to form across the Texas
Panhandle and track into Oklahoma overnight, and should gradually
head towards the Red River. Veering low-level flow ahead of this
feature should keep the brunt of shower/storm activity to the
north and east of the TAF sites. However, sufficient lift looks to
spread into the I-20 corridor to warrant another period of VCSH
towards daybreak on Friday. A brief north wind shift is also
expected to accompany this activity as outflow meanders south into
the Metroplex. Surface winds will eventually resume out of the
southwest by mid-morning.
The aformentioned outflow may provide a focus for renewed
convective development on Friday afternoon, but confidence in this
was too low to specify a period of VCSH or VCTS at this juncture.
We`ll continue a one-line TAF at Waco, where southerly winds and
VFR conditions are anticipated through the forecast period.
Carlaw
&&
.SHORT TERM... /Issued 342 PM CDT Thu Aug 10 2017/
Another hot and muggy day is underway with afternoon heat index
values climbing into the 100-104F range. Ample moisture positioned
east of I-35 allowed isolated to scattered showers and
thunderstorms to develop as convective temperatures were reached.
This activity is entirely diurnally-driven and will dissipate
with loss of heating. Latest satellite imagery already points
toward a downward trend in the vigor of the cumulus field. The
greatest remaining instability is across our southeast counties,
roughly southeast of Canton to Hearne, where the highest potential
for a thunderstorm or two still exists through sunset. Overnight
lows will be a few degrees warmer than last night, with urban
areas remaining in the upper 70s or even near 80 degrees for
overnight lows.
The primary focus for the overnight and Friday morning forecast is
on convection that is expected to develop in OK later tonight and
move ESE. This activity could affect parts of North Texas
especially our Red River counties by daybreak, as discussed below.
-Stalley
&&
.LONG TERM... /Issued 342 PM CDT Thu Aug 10 2017/
With an upper level high situated across the Texas Hill County,
North Texas will continue to be under northwest flow aloft
Friday. A shortwave currently over Colorado will continue moving
southeast, causing a complex of storms to develop across
southwestern Kansas late tonight and continue moving southeast
through the night and into tomorrow morning. The main bulk of the
precipitation will move across central Oklahoma, leaving North
Texas under a chance of showers and thunderstorms Friday morning.
As the MCS continues moving southeast, it is possible that it
will leave a remnant boundary across North Texas, continuing the
opportunities for showers and thunderstorms during the day.
Temperatures are expected to climb into the mid to upper 90s
during the day Friday. Combined with dew points in the low to mid
70s, heat index values may be between 105-107 across the
Dallas/Fort Worth metroplex and the I-35 corridor surrounding the
Waco/Temple/Killeen area. Although this may qualify for a Heat
Advisory, there is too much uncertainty at this time on whether or
not temperatures may be affected by any remaining rain, clouds,
or outflow boundaries in the area. If this is the case,forecast
temperatures would be a few degrees lower, and in turn, heat index
values would decrease..
With little movement in the upper level high across the Hill
Country, and upper level disturbances continuing to pivot around
it, another complex of storms is expected to develop late Friday
night into Saturday morning. The set up will be very similar to
Friday morning`s setup, with the main bulk of the precipitation
moving across Oklahoma. North Texas will be on the southern fringe
of showers and thunderstorms, pushing yet another outflow
boundary into our area, acting as a focus for additional
convection during the day Saturday. Temperatures will once again
climb into the mid to upper 90s across North Texas, with a few
locations across Central Texas reaching 100 degrees. Heat index
values will once again reach 105-107, mainly across areas south of
Interstate 20.
The better chances of rain will be late Saturday night into Monday
morning as another shortwave makes its way toward North and
Central Texas. This will take a slightly more southern track
compared to the two previous shortwaves, leading to the bulk of
the precipitation moving across Southern Oklahoma and North Texas.
Given the amount of rain that fell across the northeastern
counties the first half of this week, plus any additional rainfall
between Friday and Sunday, forecast rainfall totals will need to
be monitored closely. Any persistent heavy rainfall may lead to
flooding as soils have slowly become more saturated. There will be
additional rounds of rain possible Monday and Tuesday before the
center of the upper level ridge moves across Central Texas. This
will significantly decrease the rain chances across most of the
area, with only the Red River counties under a chance of rain.
Hernandez
&&
.PRELIMINARY POINT TEMPS/POPS...
Dallas-Ft. Worth 80 98 79 96 79 / 10 20 10 30 40
Waco 77 98 78 100 78 / 5 5 10 5 10
Paris 75 91 74 90 74 / 20 40 40 50 50
Denton 77 97 77 95 76 / 10 30 20 40 50
McKinney 76 96 77 94 76 / 10 30 20 40 50
Dallas 81 98 80 96 80 / 10 20 10 30 40
Terrell 76 96 77 95 77 / 10 20 20 30 40
Corsicana 77 97 77 97 77 / 10 20 10 20 20
Temple 75 98 76 100 76 / 10 5 10 5 5
Mineral Wells 74 98 75 97 76 / 10 10 10 20 30
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
90/58
Area Forecast Discussion
National Weather Service Lincoln IL
901 PM CDT Thu Aug 10 2017
.UPDATE...
Issued at 900 PM CDT Thu Aug 10 2017
A line of showers and thunderstorms has pushed eastward across the
CWA this evening, and was mainly located from about Springfield to
Pontiac as of 9 pm, with additional clusters of strong storms in
west central Illinois. Warming tops on satellite have correlated
to the general weakening trend as of late, although the storms
between Quincy and Havana still have a bit of punch to them. The
overall weakening will continue over the next few hours as the
line pushes toward the I-57 corridor, with showers and storms more
isolated by about 2-3 am. Zones/grids have been updated for the
latest PoP trends.
&&
.SHORT TERM...(This evening through Friday)
ISSUED AT 234 PM CDT Thu Aug 10 2017
Developing surface low over northern WI this afternoon has a front
stretched south and southwest through the Quad Cities and into the
Plains. A prefrontal trough has moved across the region today,
producing showers and thunderstorms north and south of Central IL,
but have so far remained clear of ILX warning area. Cumulus field
is pretty expansive across the region on satellite imagery, but
has done little to prevent the temperatures from climbing into the
low to mid 80s. Short term concern is the line of precipitation
and thunder that is currently firing to the NW, closer to the
actual front. HRRR and NAM settles the front across the area this
evening/tonight. The NAM barely brings much in the way of precip
through...whereas the HRRR is far more aggressive in settling the
thunderstorms into the area. RAP is falling somewhere in between.
Front slows considerably in the overnight hours and the precip
slows and stretches out east to west, in mainly parallel flow,
before weakening. Front is only expected to make it into the
southeast by tomorrow mid morning...and have to maintain pops in
the east central and southeastern portions of ILX through midday.
With the cold front, slightly cooler air moves into place, but
tomorrows highs will only vary by a couple degrees. The winds will
become more west/northwesterly but remain under 10kts through the
day.
.LONG TERM...(Friday night through Thursday)
ISSUED AT 234 PM CDT Thu Aug 10 2017
Cooler temperatures continue through the weekend as the highs top
out in the upper 70s/near 80. Friday night through most of Sunday,
the weather looks mild and dry, but a quick shortwave ripples
through at 500mb aloft. This wave will push another, quicker
system through the Midwest, bringing the next chance for
precip/thunderstorms. A brief respite from the rain for Tues/Tues
night, but here is where the models start to diverge pretty
distinctly. Both GFS and ECMWF start to hint at an active pattern
with a series of waves moving through an almost zonal set up
aloft. Details in the extended will surely shift through the next
few forecasts...but the set up is for a potentially active
pattern.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 540 PM CDT Thu Aug 10 2017
Widely scattered thunderstorms will affect some of our TAF
sites this evening which may bring about brief MVFR cigs
with heavy rain and gusty winds. Away from any thunderstorm
this evening, we are expecting mainly VFR conditions this
forecast period. One time frame of concern is between 13z
and 17z Friday when a cool front will be pushing across
the area. A few models have suggested some MVFR cigs will
be possible along and just after FROPA. At this point, will
lower cigs a bit but keep them above MVFR category Friday
morning. Southwest winds of 5 to 10 kts tonight, but much
higher in and near any strong TSRA, will become west to
northwest Friday morning and mainly northwest at 8 to 13 kts
across most of the area during the afternoon.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Geelhart
SHORT TERM...HJS
LONG TERM...HJS
AVIATION...Smith
Area Forecast Discussion...UPDATED
National Weather Service Jackson MS
1033 PM CDT Thu Aug 10 2017
.UPDATE...
Updated for evening discussion.
&&
.DISCUSSION...
Overall a quiet night is in store for the area as all of the
convection has winded down & decreased across the region. Most of
the area tonight will remain quiet as most of the strongest
moisture transport will be off to our east & only some limited
lift/divergence aloft will keep most of the area quiet overnight.
Some showers overnight can`t be ruled out before a shortwave &
cold front help spark more scattered showers & storms by tomorrow.
Decreased PoPs areawide overnight before some light showers begin
to move in from the east & gradually spreading back west through
the morning & day as the shortwave & front move towards the area.
Main forecast issue overnight will be some patchy dense fog. There
will be a combination of low clouds (stratus) & patchy dense fog
but a lot of the hi-res guidance, including the HRRR, ARW, NMM &
some global models show a very low condensation pressure deficits
areawide. This is due to such low dewpoint depressions & our
crossover temperatures are around 2-4+ degrees. Winds will be
fairly light overnight, mainly less than 3kts. This will help
potential for some patchy dense fog overnight. Time lagged HRRR is
also hinting at this idea as well. This looks to mainly be
between late tonight after midnight through mid- morning around
9AM Friday. Introduced a limited in the HWO/graphics for patchy
dense fog areawide. Will hold off on a dense fog advisory as the
combination in low stratus & patchy dense fog or any stronger
winds overnight may make it hard to get too dense or too large of
an area. However, these trends will be monitored. /DC/
Prior discussion below:
Only updates to the forecast were to let the flash flood watch
expire at 7PM due to the lessening rainfall rates & widespread
nature of convection gradually lessening. Adjusted PoPs to current
lessening trends but overall not much changes needed. Most
rainfall chances look later tomorrow as better moisture
convergence & upper divergence look to move in after daybreak,
with better chances of storms later as a shortwave & front
gradually drop down through the Plains and provide better focus
for storms later in the mid-late afternoon tomorrow. Took out the
limited flooding for tonight due to convection being more focused
into tomorrow. Adjusted the HWO & graphics to update the wording.
Another forecast update will likely be done in the next couple
hours. /DC/
Prior discussion below:
Tonight and Friday:
Wind field around MCV over the ArkLaMiss Delta providing good
convergence/forcing for the numerous showers and thunderstorms
over the area this afternoon. Satellite, model, and observed UA
data continue to show deep tropical moisture (PWs aoa 2 inches) in
place over the region and should continue to be the case. As
such, very little lift needed for cloud cover and convective
initiation.
In the mid levels, ridge continues to build over TX into southern LA
with the westerlies still in control of the majority of the forecast
area. Series of weak shortwaves will continue to impact the forecast
area mainly this evening and Friday afternoon. With these
conditions, numerous showers and thunderstorms will continue to
be possible with locally heavy rainfall. The lack of a low level
focus, however, should limit the widespread heavy rainfall/flooding
potential. Thus, will let the flood watch expire at 11/00Z, but
keep at least limited flood potential wording in the HWO. /26/
Friday Night through Wednesday Night:
That muggy soupy airmass is what we will continue to battle with
moving into the weekend and the start of the the following work
week. The weak cold front that dropped down from the Central Plains
on Friday will stall for the next few days around the
Ozarks/Northern MS region & continue our rain chances throughout
this time period. Despite WPC`s QPF maximum centered to the west of
our region (in Oklahoma) for the next five days, localized flooding
will continue to be a concern for the ARKLAMS area. With the ground
already super saturated in some areas, any moderate rainfall will
again create localized flooding concerns. However, trying to
pinpoint which location will be affected by flooding can`t easily be
detected. Given that ridge located over Texas alters from growing
stronger on Saturday morning and weakening come Sunday, fluctuations
on where showers/storms generate will be based on these subtle
changes. As of now, we will keep a limited threat for flooding
from Saturday into Tuesday for the the entire ArkLaMs area.
For Monday, that boundary will slowly propogate east, but POPs will
still be in the 40-50% range as diurnal showers and t-storms will
continue. A front moving in from the Central Plains on Monday
night/Tuesday morning will skirt to our north and may ignite some
storms in our northern areas, however the latest GFS run shows the
front fizzling out by the time is reaches this far south.
We may catch a break from the rain come midweek as another ridge
starts to build and center over Louisana--keeping rain chances to
our east. However, the price of the rain dying down will be hot
conditions returning. /12/
&&
.AVIATION...
00Z TAF discussion:
Scattered showers are gradually falling apart over most of the
region, except some lingering down towards HBG, PIB, MEI & NMM.
Overall main issues again will be lower ceilings (stratus) &/or
visibilities (patchy fog) overnight. Main time will be after
11/05-07Z MVFR ceilings/visibilities to move in before more IFR to
possibly LIFR ceilings &/or visibilities will move in areawide by
around 11/09-11Z. If any areas of patchy to patchy dense
visibilities (IFR or lower) develop, look for these to possibly be
near GLH, GWO, GTR, MEI & NMM. Expect these visibilities & stratus
to gradually lift around 11/14-15Z. More showers (VCSH) are possible
areawide at all TAF sites again tomorrow after 11/14-15Z and more
storms (VCTS) after 11/16-18Z. /DC/
&&
.PRELIMINARY POINT TEMPS/POPS...
Jackson 73 88 74 89 / 14 58 31 64
Meridian 73 88 74 89 / 20 61 26 59
Vicksburg 73 89 74 89 / 14 57 34 57
Hattiesburg 73 87 75 90 / 14 63 20 66
Natchez 73 88 75 88 / 14 59 25 65
Greenville 72 88 74 88 / 14 54 47 50
Greenwood 73 88 74 88 / 14 54 42 55
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...None.
LA...None.
AR...None.
&&
$$
DC
Area Forecast Discussion
National Weather Service Jacksonville FL
928 PM EDT Thu Aug 10 2017
...MUGGY TONIGHT WITH PASSING COASTAL SHOWERS...
.UPDATE...
Much less convective coverage across the area today compared to
recent days with the intrusion of some drier mid level air from
the NE on the subsident side of the broad low offshore of the
Florida Atlantic coast. Scattered sea breeze and outflow storms
were west of Interstate 75 this evening, with continued
dissipation expected through midnight. Closer toward the Atlantic
coast, convergent bands with light to moderate showers were
gradually increasing in coverage across our Florida Atlantic
waters as the broad low center drifts slowly NNW. Expect a gradual
increase in convection over the coastal waters through the night,
with the potential for some showers to move onshore impacting
coastal counties and the St. Johns River basin through sunrise.
Winds will remain elevated 5-10 mph along the coast tonight, while
inland winds will decouple under mostly clear to partly cloudy
skies. With recent rainfall and dry mid level air, potential for
fog inland exists. Updated the forecast for patchy fog for inland
areas west of Highway 301 before sunrise Friday morning, while a
chance of showers will exist along the coast. Min temps will range
in the 70s tonight with a continuation of muggy conditions.
&&
.AVIATION...
Waves of showers will move inland through the night with the
greatest potential of MVFR ceilings impacting SGJ tonight and
advertised prevailing BKN020 with VCSH. Shower potential and low
ceiling potential will increase south to north toward CRG and SSI
through sunrise, and then inland through the day Friday where VCSH
was advertised for inland terminals. Tonight potential for low
stratus and fog impacting the terminals was low via HRRR and SREF
visibility and low stratus model guidance, but there was a low (5%
chance of occurrence) of IFR cigs at GNV. Given low confidence,
refrained from inclusion in the 00Z TAF package.
&&
.MARINE...
A weak area of low pressure offshore of the central Florida
Atlantic coast will drift northwest tonight. Surface observations
indicated a slight tighter pressure gradient over the local waters
on the northern side of this low, and thus updated the forecast
leaning toward the NAM12 winds which resulted in forecast winds of
10-15 kts this evening, relaxing to 5-10 kts and backing NNE after
midnight as the low drifts northward toward the local waters.
Combined seas were running 3-4 ft with Canaveral East near 6 ft
last observation. Waves of showers, possibly some isolated
tstorms, will rotate across the waters through tomorrow around the
broad surface low.
Rip Currents: A persistent east-southeasterly ocean swell will
continue a moderate risk along NE Florida coast through Fri.
&&
.PRELIMINARY POINT TEMPS/POPS...
AMG 74 91 75 92 / 20 50 30 60
SSI 77 87 78 89 / 20 30 20 60
JAX 74 90 76 92 / 10 40 20 60
SGJ 76 88 76 90 / 20 40 30 50
GNV 73 91 74 92 / 10 60 40 50
OCF 74 91 75 91 / 10 60 40 50
&&
.JAX WATCHES/WARNINGS/ADVISORIES...
FL...None.
GA...None.
AM...None.
&&
$$
Enyedi/Zibura/McGinnis
Area Forecast Discussion...Updated Aviation
National Weather Service Saint Louis MO
656 PM CDT Thu Aug 10 2017
.SHORT TERM... (Through Late Friday Afternoon)
Issued at 252 PM CDT Thu Aug 10 2017
A cold front will push into northern Missouri early this evening
with scattered showers and thunderstorms will be possible along the
boundary over the western half of the region. The last several runs
of the HRRR generate scattered showers and storms but placement
varies run to run. The GFS/NAM/ECMWF are in consensus with moving
the cold front to the St Louis metro area or just to the south of
the city. Winds will switch from the south southwest to the
northwest but will remain light. The frontal boundary will push into
southeast Missouri and southwestern Illinois late Friday morning. A
series of upper level impulses will ride along the front providing
enough ascent for scattered showers and thunderstorms through Friday
afternoon. Temperatures will be at or just below climatological
normals.
Kelly
.LONG TERM... (Friday Night through Next Thursday)
Issued at 252 PM CDT Thu Aug 10 2017
A surface cold front will extend from the Ohio Valley across extreme
southern IL through southeast MO early Friday evening. This front
will continue to push southward on Friday night as the eastern U.S.
upper trof sharpens up and surface high pressure builds into the
upper and middle MS Valley. There will be a threat of some residual
isolated to widely scattered showers and thunderstorms in the
vicinity of the frontal zone during the evening, but the main
elements of interest with be cooler and drier air overspreading the
region in the wake of the cold front. The large scale pattern
continues to show a broad but deamplifying mean trof from the
Rockies eastward into the eastern U.S. through the weekend, and this
will maintain surface high pressure as the controlling feature
Saturday through Saturday night.
Greater model variability and poor run-to-run model consistency
exists Sunday through next week leading to less confidence in the
forecast details. The ECMWF has backed off the previous "wet"
forecast for Sunday, but both the GFS and NAM show a progressive
short wave trof moving across the region within the broad upper
trof. Lift with this wave and low level WAA/MCON attendant with a
weak southwesterly LLJ on the backside of the retreating surface
high are forecast to support showers and thundestorms, primarily for
central and northeast MO.
Differences on Monday with the strength and speed of a digging
shortwave trof once again result in uncertainty in the forecast. The
GFS is slower/stronger with QPF nearly everywhere within the 12h
period, while the ECWMF is faster and weaker and predominately dry.
Predicability continues to diminish as we head into midweek and the
pattern flattens. We see progression of a low-amplitude upper level
ridge/trof system, the models diverge on details and timing of any
precipitation chances. Below average temps still look on target
through at least the first few days of next week.
Glass
&&
.AVIATION... (For the 00z TAFs through 00z Friday Evening)
Issued at 656 PM CDT Thu Aug 10 2017
VFR conditions, outside of any SHRA or TSRA, are mainly expected
at the TAF sites thru the valid period. The best pcpn chances that
are worth mentioning will be initially this evening at UIN, with
more spotty pcpn dropping south later tonight into Friday morning
near a cold front at COU and STL metro sites.
TES
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...None.
IL...None.
&&
$$
WFO LSX
Area Forecast Discussion
National Weather Service Melbourne FL
834 PM EDT Thu Aug 10 2017
.UPDATE...
Tonight...A weak and elongated surface low offshore Brevard is
forecast to continue lifting slowly northward. Highest moisture has
been over the Treasure Coast and the models show it being pulled
northward along the coast. Wind fields will be light over land so
there will be weak low level convergence, but with the high
moisture, we will need a small chance for showers through the night
along the coast. Won`t carry thunder as afternoon convection had
little lightning and with loss of heating, any storms overnight will
be confined to the Atlantic. The HRRR and local WRF support this
general scenario. Only cosmetic changes planned to the previous
forecast.
&&
.AVIATION...Weak surface low crawling northward just offshore will
produce a moist low level cyclonic flow. This may lead to areas of
low clouds forming overnight. For now, will only carry some MVFR
ceilings across the interior terminals. The models are not showing
a lot of precip over land tonight, but high moisture associated with
the weak low could produce a few showers at the coastal terminals.
Moisture is forecast to be high areawide on Fri, so daytime heating
is expected to bring scattered to numerous showers and scattered
lightning storms.
&&
.MARINE...
Tonight-Friday...Weak surface low lifting northward through the
waters should keep the main tightened pressure gradient just to our
east. Southerly winds over the south and central offshore waters
may reach 15 knots tonight and across the north offshore waters Fri.
Otherwise, winds look 10 knots or less. Some fresh swell generated
by the tightened gradient to our east may keep seas 4-5 feet well
offshore tonight and around 4 feet Friday. Seas will be 2-3 feet
nearshore. Guidance is indicated scattered to numerous showers and
a few lightning storms through Friday.
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...None.
AM...None.
&&
$$
Forecasts...Lascody
Radar.......Sedlock
Aviation....Smith
Area Forecast Discussion...UPDATED
National Weather Service Norman OK
637 PM CDT Thu Aug 10 2017
.AVIATION...
11/00Z TAFs. Primarily VFR conditions expected outside of TSRA.
For the first 3 to 6 hours of the forecast, main impacts from TSRA
will be brief from KPNC to KOKC/KOUN to KSPS. More in the way of
widespread and longer lasting shower and storm activity still
appears possible overnight so will keep TEMPO and prevailing MVFR
conditions going into tomorrow morning. Outside of convective
strong wind gusts, prevailing winds will be light through the
period.
&&
.PREV DISCUSSION... /issued 229 PM CDT Thu Aug 10 2017/
DISCUSSION...
Will keep this short as strong storms are already ongoing. In the
broad sense, it is likely that we will experience a couple of
rounds of thunderstorms today and overnight. But the specifics are
still a little in question. The current storms in northwest
Oklahoma have lost a little punch as they moved in from the
Oklahoma panhandle. But they are moving into an area of much
higher surface based CAPE, so we expect some regeneration.
Meanwhile, additional storms are in the process of developing in
western Kansas, which may evolve into the main show tonight. And
now the last few runs of the HRRR have also been signaling the
possibility of storms in the southwest this evening as well. Will
not get too tricky on timing but have kept broad high POPs across
much of the area, and expanded them farther south with the HRRR
trends. Meanwhile, it appears we will remain in a relatively
active pattern with west-northwest flow aloft and waves moving
into the upper Midwest and the northern and central Plains.
Highest rain chances will be northeast, while still generally
drier and warmer southwest.
&&
.PRELIMINARY POINT TEMPS/POPS...
Oklahoma City OK 72 85 71 85 / 80 60 60 60
Hobart OK 72 89 73 89 / 50 30 40 50
Wichita Falls TX 75 97 76 95 / 30 20 20 40
Gage OK 67 81 68 83 / 70 30 60 60
Ponca City OK 69 84 69 83 / 80 60 40 50
Durant OK 74 95 74 90 / 20 40 40 40
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...None.
TX...None.
&&
$$
25/09/11
Area Forecast Discussion
National Weather Service Paducah KY
841 PM CDT Thu Aug 10 2017
.UPDATE...
Issued at 841 PM CDT Thu Aug 10 2017
The latest HRRR data keeps any convective activity to our
west/northwest until through 09Z, and then indicates scattered
showers and storms spreading into southern Illinois and southeast
Missouri through sunrise. Adjusted the forecast to delay the
arrival of convection overnight into Friday morning.
Temperatures are a bit tricky this evening, as clear skies and
calm winds have allowed some locations, especially in the east, to
drop faster than forecast. Would trend downward with temperatures
overnight, but clouds are expected to increase over most of the
region before sunrise. Decided to keep lows at the same general
levels, but have them occurring shortly after 06Z and then steady
or slightly warming through sunrise as the clouds increase.
&&
.SHORT TERM...(Tonight through Saturday night)
Issued at 241 PM CDT Thu Aug 10 2017
Showers from Perryville to northwest of Van Buren hitting a wedge
of drier air, and weak surface ridge. So little eastward progress
expected into the evening (we think anyway). In fact, the hi res
data dissipates activity through the evening. Then after midnight,
some redevelopment appears possible from southern IL into
southeast MO.
Friday, a mid level wave is forecast to move across the area from
WNW to ESE, Bumped up PoPs to likely by afternoon, though coverage
is still somewhat of a question. If you buy the NAM, we may see
some strong storms (isolated svr?) in west KY, though low level
flow is weak in the model. Mid level flow isn`t bad. The other
models aren`t as impressive on convective parameters. Never know
what to think of the GFS. The NAM has not been too bad lately for
near term trends, so we`ll monitor. Chances will decrease from
west to east Friday evening. Saturday into Saturday night will be
mainly dry. Maybe a slight chance of convection over SEMO.
Persistence and latest MOS used for temps. Favored the NAM overall
for PoPs/Wx.
.LONG TERM...(Sunday through Thursday)
Issued at 241 PM CDT Thu Aug 10 2017
Medium confidence in the extended period, with model disagreement
continuing with regard to timing and placement of shortwave energy
across the area.
Sunday starts off with weak surface high pressure that gradually
loses its grip on the region. 12z model guidance has generally came
in slower with timing of precipitation, with consensus supporting
Sunday evening into at least the first half of Monday now. 12z GFS
continues to be an outlier, keeping rain with the Sunday wave south
of the area, and has secondary stronger energy moving through Monday
into Monday night. Thus kept in small chance PoPs through Monday
evening/night. The highest QPF amounts are expected across the
southern half of the region, and northern counties may not end up
with much.
Surface high pressure builds in from the north on Tuesday, providing
a dry weather day. The 12z ECMWF and Canadian came in faster with
southerly flow/moisture returning and bring back in precipitation
chances for the western half of the area by Wednesday. GFS and its
ensemble mean continue to support a slower wave and keep it dry
until Wednesday night or Thursday. The blended approach stuck with
the slower solution with PoPs not returning until Wednesday
night and peaking again next Thursday.
Temperatures will continue to average below normal through the
period with highs generally in the low to mid 80s and lows dipping
into the mid 60s. Humidity levels also aren`t expected to get too
carried away with dewpoints in the mid to upper 60s much of the
time.
&&
.AVIATION...
Issued at 1209 PM CDT Thu Aug 10 2017
VFR conditions with light winds through midday Friday. Small
chance of showers and storms after 06z. Not enough confidence in
the chances and coverage to include in the TAF`s.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...None.
MO...None.
IN...None.
KY...None.
&&
$$
UPDATE...DRS
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