Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 08/30/20
Area Forecast Discussion
National Weather Service La Crosse WI
1100 PM CDT Sat Aug 29 2020
.SHORT TERM...(Tonight through Monday)
Issued at 100 PM CDT Sat Aug 29 2020
Pretty nice weekend to round out August with cooler and less humid
air under the influence of high pressure building in from the
northern plains. Looks like a pretty good setup for fog in the river
valleys for Sunday morning with high working overhead.
Upper level shortwave trough slated to move southeast out of western
Canada today, gradually dropping across upper mississippi river
valley Sunday night/Mon. Surface cold front accompanies the trough,
with the NAM/GFS/EC all on good agreement with sliding it across the
local area between 12-18z...but weakening as it does. 850 mb
moisture transport is meager, and mostly pointing north into the
shortwave. Little if any CAPE to play with shear mostly post front.
Looks like a decent shot for rain - better to the north under the
influence of the upper level trough - but thunder chances look
minimal. Amounts should be minor.
.LONG TERM...(Tuesday through Saturday)
Issued at 100 PM CDT Sat Aug 29 2020
Northwest flow a loft looks to persist into the upcoming weekend,
which will keep the area under relatively cool conditions, but still
not too far off the seasonable normals for the start of Sep.
After Monday`s rain chances, another shot to get wet comes in
Tuesday. A ripple in the upper level flow is progged to move out of
the southern plains, working along the lingering sfc front from
Monday. Some moisture transport to fuel shower/storm chances. Some
instability to play with, but much of that is slated to hold farther
south. Meanwhile the deeper shear hangs to the north. GFS/EC favor
pcpn chances from ne ia into central WI, with bulk of GEFS members
also onboard.
Next shortwave comes through the northern stream and skirts across
far northern portions of the region, dragging a cold front with it.
Saturation looks hard to come by south of the upper level wave with
GFS/EC and most of the GEFs members holding any QPF to the north.
Chimney could see some pcpn chances, but as it stands, could be a
mostly dry frontal passage for the local area.
&&
.AVIATION...(For the 06Z TAFS through 06Z Sunday night)
Issued at 1059 PM CDT Sat Aug 29 2020
The main forecast question for tonight is whether valley fog will
affect KLSE. The RAP and GFS keeps the area too dry for valley fog
development at the airport. Meanwhile, the NAM still hints at
valley fog development. However, with a 30.03z temperature/dew
point spread of 10F, the probabilities are not that high.
During the mid to late afternoon of Sunday, a 15-20K deck of
clouds will move into the area from the west as warm air advection
moves into the region ahead of an approaching shortwave trough.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
IA...None.
&&
$$
SHORT TERM...Rieck
LONG TERM....Rieck
AVIATION...Boyne
Area Forecast Discussion
National Weather Service Boston/Norton MA
1021 PM EDT Sat Aug 29 2020
.SYNOPSIS...
Any showers and storms coming to an end relatively soon here and
the cold front slides through. Sunday looks to feature a taste
of early Fall with cooler, blustery and much drier weather that
lingers into Monday. Then the weather becomes unsettled with the
risk for scattered showers and thunderstorms Tuesday through
Friday. No washouts are expected. Turning warmer and more humid
Wed, Thursday and possibly into Friday.
&&
.NEAR TERM /THROUGH SUNDAY/...
10 PM Update...
Have taken down the Severe Thunderstorm Watch as thunderstorm
activity has diminished as depicted by the high resolution
guidance. Still could have a rumble of thunder or two along with
brief gusty winds before storms completely die out. Updated
precipitation chances slightly with the latest HRRRE guidance.
Have also cleared skies by blending the previous forecast with
the latest HRRRE which matches up well with the latest
observations. Rest of the forecast remains on track and looks
good at this point in time.
730 PM Update...
Severe Thunderstorm Watch for Connecticut, western and central
Massachusetts until midnight.
Have updated precipitation chances a bit from the previous
forecast based on the last few HRRR runs and the earlier NSSL
WRF. No changes at all from the previous forecast in the risk
with the threats being damaging wind gusts, heavy rainfall and
there is a risk of tornadoes.
From SPC mesoanalysis still have 40-45 kts of effective bulk
shear, roughly 1000-1500 J/kg of MLCAPE in the watch area. On
top of this LCL heights are low, roughly 500-750 m, with 0-1 km
SRH of 100 to 150. Downdraft CAPE values are still a few hundred
J/kg.
Will need to keep a close eye on this activity as am a bit
skeptical in the decaying trends from guidance. Instability
does diminish, but still have roughly 500-1000 J/kg of MLCAPE to
work with around and after 03-05Z. Will continue to see how
things trend and update when things become clearer. The current
forecast goes along with the diminishing trend as shown by
several CAMs today.
335 PM Update...
* A few severe t-storms possible between 6 & 10 pm in western
MA/northern CT with the greatest risk west of the CT River
Scattered showers continue to impact mainly eastern MA/RI late
this afternoon. This activity is being caused by a modest
southwest low level jet coupled with the warm advection
pattern. The bulk of this activity should exit most of the
region over the next few hours, as best initial forcing/moisture
continue to move east.
The main concern will then turn to the risk for a few severe
thunderstorms across western MA/northern CT, with the greatest
potential west of the CT River. This will be in association
with a shortwave/cold front approaching from the west and
depend on if we can generate enough instability. While the
greater risk for severe weather will be west of our region, a
few severe thunderstorms may work into western MA and CT this
evening. We might be able to generate MLCapes on the order of
1000 to 1500 J/KG by early evening. This coupled with 40 knots
of effective shear may result in a few severe t-storms, roughly
between 6 and 10 pm this evening across western MA and northern
CT. If this is realized, the main severe risk would be localized
damaging wind gusts across western MA and northern CT. However,
enough low level backing and shear will generate 100 to 200
units of 0-1 KM helicity. Therefore, a low risk does exists for
a tornado.
So in a nutshell, whether we are able to see any severe weather
across our interior zones this evening will depend on how much
instability we can generate. The greatest risk will be west of
the CT River. If that does occur, expect activity to weaken as
it tries to work into eastern MA/RI with less instability later
this evening.
&&
.SHORT TERM /SUNDAY NIGHT/...
* Beautiful Sunday with pleasant temperatures/low humidity
although it will be breezy
Late Evening Into The Overnight Hours...
It is possible a few showers/t-storms survive into eastern
MA/RI given modest effective shear, but should be in a weakened
form and are not expected to be severe.
Otherwise, it will be dry late tonight into the overnight hours.
The main story will be a much less humid/cooler airmass working
in behind a cold front overnight. By daybreak, overnight low
temps should be down into the upper 50s to the middle 60s with a
nice northwest breeze.
Sunday...
A beautiful day is in store to close out the last weekend in
August. Partly to mostly sunny skies expected with a gusty
northwest wind are on tap in the post frontal airmass behind
tonight/s cold front. High temps should should generally be
between 75 and 80 degrees, but with low/comfortable humidity.
Northwest wind gusts of 20 to 30 mph are anticipated, so it will
be a bit breezy but overall a beautiful day.
Sunday night...
High pressure builds in from the west allowing for diminishing
winds and mainly clear skies. The dry airmass in place coupled
with light winds will allow for a cool night and good
radiational cooling conditions. Low temps will bottom out in
the middle to upper 40s in the normally coolest outlying
locations, to the lower to middle 50s in most other locations.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
Highlights
* Dry and quiet with seasonable temperatures on Monday.
* Temperatures trending upward for the rest of the week with chances
of showers and perhaps some thunderstorms.
Monday...
Ridge axis builds from eastern Ontario early on Monday into Quebec
and New England by later in the day. At the surface high pressure
will build over New England for much of the day before sliding
offshore during the afternoon.
Fall like feel temperature wise across southern New England, but
should not be breezy with the high building overhead. Winds aloft
shifting from the WNW to the W and eventually the SW/S. Will remain
comfortable dew point wise, but will see values starting to creep up
into the mid to upper 50s across the south coast during the
afternoon. Highs in the 70s.
Monday night through Tuesday night...
The ridge axis builds into eastern Quebec Monday night into early
Tuesday. A shortwave trough lifts from the Ohio River Valley on
Monday into southern New England by early Tuesday morning. Still
have spread in the amplitude and timing of the wave lifting in. A
relatively big change amongst guidance since 24 hours ago. The
shortwave interacts with a stalled out frontal boundary/baroclinic
zone offshore and develops a low south of region. The low remains
offshore, but keeps southern New England under easterly flow and
given the broad lift cannot rule out some rain showers. Have leaned
heavily on the NBM guidance for this timerange given the
differences, but if models continue to trend in the coastal low
direction...will need to lower temperatures due to the strong
persistent onshore flow in future updates.
Wednesday through Friday...
Confidence in the specific sensible outcomes during this time frame,
but do have confidence in temperatures and humidity levels on the
rise. Progressive pattern with a ridge over the Western US and
broadscale troughing over the Central into the Eastern US. This
timeframe features several waves moving in, but still have spread in
timing and amplitude. Appears that it will remain unsettled with
chances of showers and perhaps some thunderstorms, but no washouts
are expected.
Again fairly consistent signal of S/SW flow aloft through this
period. This will result in dew points and temperatures on the rise
a warm moist air advects in. By Thursday and Friday readings will be
back into the lower to middle 80s with dew points in the mid to
upper 60s.
&&
.AVIATION /02Z SUNDAY THROUGH THURSDAY/...
Forecaster Confidence Levels...
Low - less than 30 percent.
Moderate - 30 to 60 percent.
High - greater than 60 percent.
Tonight through 06Z...Moderate confidence
Generally VFR conditions, only exception is across FMH/ACK/HYA
where IFR conditions to start. Main concern is the thunderstorm
activity spreading in from west to east. Still anticipating a
diminishing trend per past several runs of the HRRR along with
other CAMs from today. Am a bit skeptical in the diminishing
trend given the SPC Mesoanalysis keeps a few hundred to 1000
J/kg of CAPE. So if activity lingers, eastern terminals will see
around 04-06Z. Have held off from including in the latest
update at BOS and PVD, but may be needed in future updates. Have
added VCTS at BDL/BAF/ORH, but will need to update based on
trends to add TSRA soon. Expecting reduction to MVFR/IFR and
possibly LIFR as a storm slides through with potentially
damaging wind gusts and possibly some hail.
After 06Z...High confidence
Improvement to VFR at most locations, except for the Cape and
especially ACK where low clouds and fog may hang on a bit
longer until the front sweeps through. Winds shift to the WNW
at 10 to 15 knots with some 20 to 25 knots in the typical non-
decoupling spots.
Sunday: High confidence.
VFR with NW wind gusts up to 25 knots.
Sunday night...High confidence.
VFR with wind becoming light.
KBOS Terminal...High confidence in TAF.
KBDL Terminal...Moderate confidence in TAF. Main concern is the
risk for a strong t-storm in the vicinity of the terminal
between 01z and 03z.
Outlook /Monday through Thursday/...
Monday: VFR.
Monday Night: Mainly VFR, with local MVFR possible. Slight
chance SHRA.
Tuesday: Mainly VFR, with areas MVFR possible. Slight chance
SHRA.
Tuesday Night: Mainly VFR, with areas MVFR possible. Chance
SHRA.
Wednesday: Mainly MVFR, with areas VFR possible. Chance SHRA.
&&
.MARINE...
Tonight and Sunday...High confidence.
Marginal southwest SCA wind gust of 20 to 25 knots will
continue this evening ahead of an approaching cold front. Winds
shift to the W overnight behind the cold front and then NW on
Sun. This should yield widespread 20 to 30 knot wind gusts
across all waters into Sun afternoon. Therefore, SCA headlines
are posted for all waters.
Sunday night...High confidence.
High pressure building in from the west will result in winds
dropping below SCA thresholds across all waters early in the
evening. Lingering 4 to 5 foot seas will persist a bit longer
across our southeast waters, so will carry marine headlines longer
in this region. However, all waters should drop SCA criteria by
daybreak Mon.
Outlook /Monday through Thursday/...
Monday: Winds less than 25 kt. Seas locally approaching 5 ft.
Monday Night: Winds less than 25 kt.
Tuesday: Winds less than 25 kt. Seas locally approaching 5 ft.
Slight chance of rain showers.
Tuesday Night: Winds less than 25 kt. Areas of seas approaching
5 ft. Slight chance of rain showers.
Wednesday: Winds less than 25 kt. Seas up to 5 ft. Slight
chance of rain showers.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...None.
RI...None.
MARINE...Small Craft Advisory until 8 PM EDT Sunday for ANZ231>235-237-
250-251-256.
Small Craft Advisory from 9 AM to 6 PM EDT Sunday for ANZ230-
236.
Small Craft Advisory until 2 AM EDT Monday for ANZ254-255.
&&
$$
SYNOPSIS...Frank/BL
NEAR TERM...Frank/BL
SHORT TERM...Frank
LONG TERM...BL
AVIATION...Frank/BL
MARINE...Frank/BL
Area Forecast Discussion
National Weather Service Brownsville TX
907 PM CDT Sat Aug 29 2020
.DISCUSSION...
Overall, only made a few minor changes for tonight. Added a slight
chance of showers for the offshore waters but otherwise kept the
remainder of the area dry. The latest HRRR and HREF have backed
off on rain chances for the nearshore waters and coastal areas for
tonight. Expect the better moisture surge to occur during the day
on Sunday per much of the model consensus. Still only expecting
isolated convection for mainly the waters and adjacent coastal
areas, aided in part by the seabreeze circulation. Kept temps
above normal for tonight with most of the lower valley remaining
around 80 to lower 80s for overnight lows.
&&
.PRELIMINARY POINT TEMPS/POPS...
BAYVIEW/PORT ISABEL 80 95 82 95 / 0 20 0 10
BROWNSVILLE 82 96 83 97 / 0 20 0 10
HARLINGEN 80 97 81 98 / 0 10 0 10
MCALLEN 80 99 82 100 / 0 10 0 0
RIO GRANDE CITY 79 103 80 105 / 0 0 0 0
SOUTH PADRE ISLAND 84 89 85 89 / 10 10 10 0
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...None.
GM...None.
&&
$$
This product is also available on the web at:
HTTPS://WEATHER.GOV/BRO
80-MB
AREA FORECAST DISCUSSION
National Weather Service Eureka CA
304 PM PDT Sat Aug 29 2020
.SYNOPSIS...Very warm and smokey conditions will continue across
much of interior northwest California through the weekend, though
northerly winds will help bring clearer skies Humboldt and Del
Norte counties. Areas of morning clouds will give way to sunshine
and breezy conditions each afternoon through Monday along the
Redwood Coast. Otherwise, dry weather will persist through next
week with near to above average temperatures.
&&
.DISCUSSION...Increasing low-level northerlies are aiding in
moving smoke southeast away from Humboldt and Del Norte counties.
Unfortunately, thick smoke remains over much of Mendocino and
Lake counties, which is resulting in areas of locally cooler
afternoon temperatures, as well as producing unhealthy air
quality (refer to the latest air quality alert for more
information). Beside smoke, stratus is dissipating along the
Humboldt/Del Norte coast. Model guidance is in strong agreement
depicting dry air spreading south and maintaining nearly stratus
free marine conditions through Sunday. Thereafter, a boundary
layer eddy is forecast to develop offshore from Mendocino county
and aid in renewed stratus development, though north winds north
of Cape Mendocino may prevent stratus from surging north up the
Humboldt/Del Norte coast.
Otherwise, upper heights and a building ridge are forecast to
develop over the western CONUS during early to middle portions of
next week. A warm deep-layer airmass will develop as a result and
aid in highs in the 90s to low 100s across many interior valleys.
Heat risk concerns will increase as a result. The marine layer may
also erode sufficiently for highs in the 70s along the coast.
Garner
&&
.AVIATION...Widespread haze lingers over Mendocino, Lake and
Trinity counties today today, with impacted visibilities in
Mendocino and Lake counties. HRRR smoke guidance is suggesting
visibilities in these areas will improve late this afternoon as
onshores push the smoke off toward the east, with vfr conditions
expected again overnight tonight.
Farther north in Del Norte and Humboldt counties, stratus from a
southerly surge overnight slowly eroding early this afternoon
while low-level gusty north winds move closer to the coast. Gusty
northerlies are expected to weaken and shift NNE tonight in Del
Norte, with a stronger offshore component aloft possibly
supporting LLWS at KCEC. HIRES guidance is indicating another
southerly wind reversal and associated northward surge of stratus
this evening as strong northerlies build offshore, however
offshore winds developing in Del Norte county overnight may keep
the stratus confined to the Humboldt Bay region and northern
Humboldt coast. Additionally, lighter offshore winds just above
the surface in Humboldt tonight may prematurely erode stratus
early this morning, however confidence remains low regarding if
these will be sufficient to do so. /TDJ
&&
.MARINE...ASCAT satellite wind data from a pass late this morning
suggests that winds have been a little slower to ramp up today
than expected, however most of the recent high resolution model
guidance (NAMNEST, ARW, NMMB, HRRR, etc.) continues to depict
strengthening northerlies this afternoon persisting through
tomorrow night. Wind speeds are then expected to receive another
strengthening push tomorrow afternoon as high pressure builds
further over the NEPAC and the local thermal trough is deepened by
afternoon heating, both acting to tighten the nearshore pressure
gradient. Sustained wind speeds of 30 to 40 kts with gusts nearing
50 kts are expected to develop in response tonight and persist
through early Monday morning within the strongest wind core in the
Northern Outers. These winds will generate seas of 14 to 18 ft
across the outer waters, largest during the day on Sunday. GALE
FORCE winds will likely reach close to the headlands of Point St
George and Cape Mendocino, but otherwise model guidance indicates
a sharp wind gradient toward the coast with significantly weaker
winds nearshore, with HIRES guidance indicating possible overnight
southerly wind reversals along the coast in northern Humboldt and
Mendocino counties.
Steep northerly seas propagate into all zones beginning this
afternoon, and hazard products remain unchanged with the afternoon
forecast package. Toyed with the idea of a issuing a Gale Warning
for the southern outers as a few models are depicting winds just
above the surface ripping around 50 kts...however model soundings
are showing the strongest winds lingering above the marine layer
inversion, and thus may have problems frequently mixing down to
the surface. Additionally, this band of possible GALE FORCE gusts
looks to be confined to the areas just south of Cape Mendocino and
the farthest northwesterly quarter of zone 475...while very steep
and hazardous seas propagate across most of the zone, thus
decided to leave haz seas as the predominant hazard. The southern
inners still look sufficiently protected in the lee of Cape
Mendocino that an SCY should suffice, however steep and hazardous
seas of 10 to 13 ft will plague Cape Mendocino through the
weekend.
Conditions look to significantly improve heading into next week
as the high currently building over the NEPAC slips overhead and
the pressure gradient relaxes, possibly bringing a period of
widespread light-and-variable-mixed-with-rounds-of-southerly winds
around mid- week. /TDJ
&&
.FIRE WEATHER...An upper-level trough is forecast to dig
southeastward across the Intermountain West Sunday through
Tuesday. That process will favor periods of northeasterly offshore
flow across portions of northwest California. The ridges of Del
Norte county will be particularly impacted tonight through Monday
morning. Gusts to 30 mph combined with low daytime humidity values
and poor overnight recoveries will yield locally critical fire
weather conditions. The inherited fire weather watch has been
maintained as a result.
In addition, north to northeast winds from 10 to 20 mph with gusts
to 30 mph will be possible over eastern Lake county Sunday night
through Monday morning. Those winds combined with a dry boundary
layer airmass will result in additional fire weather concerns.
&&
.EKA WATCHES/WARNINGS/ADVISORIES...
CA...Fire Weather Watch from Sunday afternoon through Monday morning
for CAZ203-204.
NORTHWEST CALIFORNIA COASTAL WATERS...Small Craft Advisory until
3 PM PDT this afternoon for PZZ450.
Hazardous Seas Warning until 3 AM PDT Monday for PZZ450.
Gale Warning until 6 PM PDT Monday for PZZ470.
Small Craft Advisory until 3 AM PDT Monday for PZZ455.
Hazardous Seas Warning until noon PDT Monday for PZZ475.
&&
$$
Visit us at https://www.weather.gov/eureka
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For forecast zone information
see the forecast zone map online:
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Area Forecast Discussion
National Weather Service El Paso TX/Santa Teresa NM
527 PM MDT Sat Aug 29 2020
.AVIATION...00Z TAF CYCLE...
Isolated showers and thunderstorms with visibility around 3
miles...skies BKN050-070 and wind gusts to 40 kt mainly 00Z-03Z
this evening and after 20Z on Sunday. Otherwise mostly VFR
conditions with skies SCT-BKN100 and wind speeds 5-10 kts.
&&
05-Rogash
.PREV DISCUSSION...258 PM MDT Sat Aug 29 2020...
.SYNOPSIS...
For Sunday and Monday, we will be not as hot with better chances
for rain. Then on Tuesday we will begin a drying trend that will
last much of next week. High temperatures next week will run just
a few degrees above average. By Friday and into next weekend, a
slight chance for rain will return to the forecast.
&&
.DISCUSSION...
.SHORT TERM...Tonight and Sunday...
SPC mesoanalysis suggests a good amount of CIN across much of the
region at this hour (~18Z), even more than the latest projected HRRR
run. If this is the case, convection will have a hard time
developing this afternoon, except for the higher terrain. That being
said, the deepest moisture still remains around the Cont Divide and
west/southwest, so storms expected in this region. Convection in
this area may shoot off some outflow that pushes east into the
evening and early overnight producing mildly breezy to breezy winds,
and perhaps the chance for a few showers with an embedded
thunderstorm not out of the question. Instability will remain very
weak overnight, so would be surprised if anything more than a few
rumbles of thunder develop from any low level collisions east of a
line from T-or-C and Deming, but perhaps showery enough for 20 POPs.
Moisture will increase on Sunday via west winds as the ridge
flattens and sags south, which all signs point to an uptick in
activity, at the very least. However, instability looks to remain
rather weak and minimal (according to the GFS/EC; NAM3KM is a little
more overdone, but nothing too significant, except for SW NM), so
have concerns about a lackluster performance on Sunday despite PWATs
well above an inch. Moisture will be elevated and above normal
though through the column, so all it takes is a decent outflow
boundary off the Sacs/Gila/SW NM to get things going. All in all,
expecting better chances for showers and thunderstorms on Sunday
with mildly breezy west winds, and temperatures in the mid to upper
90s.
&&
.LONG TERM...
On Monday our precipitable water values (PW`s) will continue to
increase. We could see PW`s of 1.50, which will be well above
average for this time of year (or anytime of the year). In
addition a shortwave trough out ahead of the main trough moving
across Colorado should give us some added lift. All in all on
Monday, it looks like we will see the best chances for rain that
we have seen for much of the summer. Depending on the amount of
clouds and rain our high temperatures might drop a hair below
average on Monday. For now I`ll stick with the slightly above
average temps in the forecast, but hey, cooler is cooler. We need
to make the most out of any rain we can on Monday, because on
Tuesday as the main upper level trough swings through northern
New Mexico, it will usher in much drier air. We will quickly dry
out on Tuesday, probably not fast enough to pull all the rain
chances on from the forecast, but we are looking pretty dry for
Wednesday and Thursday (PW`s running around 0.50). As the clouds
and rain leave we will see our high temperatures creep a few
degrees higher, but nothing like we have seen the last couple of
weeks. For the end of the week, the upper level ridge, that had
migrated all the way out to the West Coast, will drift a little
further east and settle over Utah and Nevada. That position will
give us a more northeasterly or easterly flow aloft. We will
continue to see mostly dry air move into the area, but we may
start to bring in a little moisture, so I can`t rule out a stray
thunderstorm or two on Friday and Saturday evenings. Temperatures
though look to continue pretty pleasant with highs running just a
few degrees above average for the end of the week.
&&
.FIRE WEATHER...
Thunderstorm chances gradually increase Sunday and again on Monday
as moisture flows in from the west. Heavy rain and gusty winds will
be the main threats with the strongest activity, especially on
Monday. A trough approaches on Tuesday, increasing wind speeds into
the breezy category, and ejecting a much drier and cooler airmass
(although still above normal temps) into the region. This dry air
will all but diminish storm chances through the end of the week,
except for the very isolated storms over the mtns. Regardless,
precipitation potential remains low through next weekend.
Min RH increases generally to 25-35% Sun-Mon, then decreases Tuesday
but remaining above critical levels, and especially on Wed/Thurs
with values just below 15% lowlands, and near 20-25% mtns.
Ventilation remains Poor to Good through Monday, increasing to
Excellent on Tuesday.
&&
.PRELIMINARY POINT TEMPS/POPS...
El Paso 76 98 74 94 / 20 20 20 20
Sierra Blanca 69 96 70 91 / 0 20 20 20
Las Cruces 71 95 68 91 / 20 20 20 10
Alamogordo 70 98 68 93 / 20 20 20 20
Cloudcroft 52 75 51 70 / 20 30 20 40
Truth or Consequences 71 94 70 91 / 20 20 20 20
Silver City 65 86 62 84 / 20 30 20 40
Deming 70 94 67 92 / 20 20 20 20
Lordsburg 70 90 67 89 / 30 30 30 40
West El Paso Metro 78 100 76 96 / 20 20 20 20
Dell City 70 101 71 95 / 10 20 20 10
Fort Hancock 75 101 75 98 / 10 20 20 20
Loma Linda 72 92 72 88 / 20 20 20 20
Fabens 76 99 75 95 / 20 20 20 10
Santa Teresa 73 97 71 93 / 20 20 20 10
White Sands HQ 74 96 72 92 / 20 20 20 20
Jornada Range 72 96 70 91 / 20 20 20 20
Hatch 71 96 68 92 / 20 20 20 20
Columbus 74 95 70 92 / 20 20 20 20
Orogrande 71 96 70 93 / 20 20 20 20
Mayhill 59 84 58 80 / 20 30 20 40
Mescalero 57 84 56 80 / 20 30 20 40
Timberon 57 83 55 78 / 20 20 20 30
Winston 58 86 56 83 / 20 40 20 40
Hillsboro 66 93 63 90 / 20 20 20 30
Spaceport 70 95 67 90 / 20 20 20 20
Lake Roberts 57 86 55 83 / 20 40 20 40
Hurley 65 88 62 87 / 20 30 20 30
Cliff 65 91 64 90 / 20 30 30 40
Mule Creek 65 86 64 84 / 20 30 30 50
Faywood 67 89 63 87 / 20 20 20 30
Animas 69 90 65 90 / 30 40 30 40
Hachita 68 90 65 90 / 20 30 30 30
Antelope Wells 68 88 65 89 / 30 40 40 50
Cloverdale 65 82 63 82 / 30 50 40 60
&&
.EPZ WATCHES/WARNINGS/ADVISORIES...
NM...None.
TX...None.
&&
$$
05-Rogash/34/05
Area Forecast Discussion...UPDATED
National Weather Service Austin/San Antonio TX
830 PM CDT Sat Aug 29 2020
.UPDATE...
The Heat Advisory was allowed to expire at 8 PM. The heat continues
on Sunday with forecast high temperatures near 100 to 105 degrees.
Heat index forecast values range from 105 to 112 degrees. If this
trend continue once the midnight shift crew downloads the latest
model data, it is likely to have another Heat Advisory for areas
east of Interstate 35 on Sunday. Otherwise, dry with a slight chance
for rain across the Coastal Plains on Sunday afternoon.
&&
.PREV DISCUSSION... /ISSUED 541 PM CDT Sat Aug 29 2020/
AVIATION...
/00Z TAFS/
VFR conditions are expected across area terminals through the
forecast period. Southeast to south winds of 5 to 10 knots are
forecast for the I-35 airports through Sunday evening. A more
east to southeast wind flow is forecast for KDRT through the period.
Some HiRes models suggest for a complex of storms to push down from
the Southern Plains into central Texas on Sunday morning. These
storms should stay well to the north and east of area terminals.
PREV DISCUSSION... /ISSUED 253 PM CDT Sat Aug 29 2020/
SHORT TERM (Tonight through Sunday Night)...
With upper level high pressure over our area the heat is on today.
Heat indices are already above 105 from New Braunfels to Austin,
Gonzales to Giddings, down to La Grange. They should continue to
increase through the afternoon and top out between 107 and 110 along
and east of the Interstate 35 corridor. With ambient temperatures
pushing up and over the Century mark for most places across South
Central Texas and afternoon dew points still well into the 60s the
resulting heat indices are the reason that the Heat Advisory remains
in place through this evening. The area should be precipitation free
today with the HRRR and other high resolution models keeping any
isolated showers and storms to our east from Bay City to Wharton
towards the Houston Metro area. Could a stray shower pop up in the
very moist surface environment once convective temperatures are
reached shortly (models soundings peg those around 100 degrees)?
Sure, but as we have seen the last few days those will be very
isolated and the exact location hard to determine until the storm
pops up. Still though, those chances are low and not mentioned in the
afternoon package.
The ridge does very little to loosen its grasp of the weather here
in South Central Texas for Sunday. With this, high resolution models
have also backed off on any Coastal Plains precipitation for Sunday
as well and have gone with a dry forecast. Have also decided to not
hoist up another Heat Advisory at this time. It looks like dew
points may mix out slightly better for Sunday afternoon, keeping
heat index values just below criteria levels. Will let the midnight
crew tonight assess the 00z models and make a final determination on
any potential Heat Advisory for tomorrow. The night tonight will be
partly cloudy and mild with overnight lows from the mid 70s to near
80 degrees. Record high minimums for yesterday were within 1 to 3
degrees of record values along the Interstate 35 corridor, and this
will be the case again overnight tonight. At Del Rio for Friday the
record high minimum temperature was blown out of the water. the
previous record was 80 degrees from a year ago. It only got down to
84 degrees for Friday at DRT. Record highs though won`t be in
jeopardy with ambient temperatures running close to 100 and the
records mostly from 105 to 110 due to this normally being the
hottest part of the year.
LONG TERM (Monday through Saturday)...
We start out the week just as hot or even hotter than we left it.
Monday has highs from 100-105 across most of the area with the
exception of the Hill Country where it will be a crisp 97-99 degrees.
Tuesdays temperatures will a bit more tricky, though still quite hot.
An upper trough ejects out of the Rockies and into the Texas
Panhandle bringing increases rain chances for the area Tuesday and
Wednesday. Best chances will be for the areas in the Hill Country and
Edwards Plateau. By Tuesday evening, the trough continues it`s trek,
further increasing chances for rain for most of the area. The models
still have some timing differences but general consensus is there
should be a decent chance for rain for the area. WPC has QPF of up to
and inch in our northern counties with at 1/4 to 3/4 for the I-35
corridor. These showers and increased cloudiness should help tamper
down the temperatures for Wednesday and Thursday.
&&
.PRELIMINARY POINT TEMPS/POPS...
Austin Camp Mabry 79 101 78 100 80 / 0 0 0 - 10
Austin Bergstrom Intl Airport 77 101 78 100 78 / 0 0 0 - -
New Braunfels Muni Airport 78 100 77 100 78 / 0 0 0 - -
Burnet Muni Airport 77 101 76 100 77 / - 0 0 - 10
Del Rio Intl Airport 80 105 80 105 81 / 0 0 0 0 10
Georgetown Muni Airport 79 102 78 101 79 / - - 0 - 10
Hondo Muni Airport 77 104 77 103 78 / 0 0 0 0 -
San Marcos Muni Airport 78 101 77 100 78 / 0 0 0 - -
La Grange - Fayette Regional 79 101 79 100 80 / - 10 0 20 -
San Antonio Intl Airport 79 101 78 101 80 / 0 0 0 - -
Stinson Muni Airport 79 101 79 100 80 / 0 0 0 - -
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
Short-Term/Aviation...17
Long-Term...Platt
Area Forecast Discussion...UPDATED
National Weather Service Gray ME
1006 PM EDT Sat Aug 29 2020
.SYNOPSIS...
Low pressure crosses the region through tonight with areas of
rain and a few storms. An upper level trough will produce a few
clouds and scattered showers across the higher terrain on Sunday,
with the remainder of the region being breezy. High pressure
will build in from Canada early next week for a period of dry
weather possibly followed by some more rain midweek.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
10 PM Update...
Have updated the forecast to drop Cheshire Co from the severe
thunderstorm watch. Still some heavy rainfall and slightly gusty
winds with these storms, as well as lightning. Patchy fog has
developed both ahead of and behind the convection. Wind shift
with westerly winds gusting into the 20-25 mph range is in VT
and NY state and will reach NH and ME overnight, clearing out
low level moisture and fog in the early morning hours.
745 PM Update...
Cheshire County NH has been placed in a severe thunderstorm
watch with some strong thunderstorms nearing from the west. Some
of this convection is moving more south than east with time,
and with the loss of daytime heating, we have a small window for
any severe weather to occur. The storms to the west have so far
produced damaging winds, hail, and at least one tornado in NY
state. In any case the watch will most likely be cancelled well
before midnight.
630 PM Update...
Minor changes to adjust forecast temperatures and PoPs to match
recent observations. A few stronger storms are affecting
southern VT with stronger line segments moving through eastern
NY. We have had some clearing in southern NH around Keene and
Jaffrey. So far it looks like convection moving towards VT is
diving more south than east and looks like it will miss NH.
However, convection farther to the west may still eventually
reach the CT River valley later tonight. When/if it does it
will likely just be heavy rain with isolated thunder as
instability wanes. Will continue to monitor the evolution.
Previous discussion...
At this hour, RAP analysis shows a low pressure center shifting
east down the Saint Lawrence Valley with a pressure trough
extending all the way down the northeast CONUS, connecting with
the moist and disjointed remnants of Laura over the Mid-
Atlantic. A band of warm frontal, moderate to heavy rainfall is
exiting the forecast area to the east, but a digging northern
stream trough aloft driving the system is steeping lapse rates
in a dry slot over upstate New York. Our area is in a relative
lull at this hour but numerous showers and a few storms are
firing upstream and will track into the area by the evening.
Have included isolated thunder over our area coinciding with
this; while clear skies are helping destabilization upstream, we
remain cold-air dammed here which will stunt convective chances.
The caveat is that a few storms could maintain themselves in
elevated instability and track into our area. With very strong
shear in play... can`t rule out damaging wind gusts only in
strong storms but coverage will be low and CAMs are trending
toward less threat for our area.
The primary cold front with this system is currently hanging
back in the lower Great Lakes region. While showers and storms
will decrease in coverage late this evening, the cold front
will hang back a little - giving many areas a chance at fog
formation overnight until this front crosses by morning.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...
By tomorrow morning, the northern stream trough aloft will have
rotated negatively with its axis and deep moisture exited to the
east toward the maritimes. Its center remains nearby over the
Saint Lawrence however so with this upper support along with
sustained cold advection through the mid-levels am expecting
scattered rain shower activity to continue over the mountains
through the afternoon until upsloping moisture wanes. Stiff
northwest winds aloft along the base of the trough, along with
favorable mixing in cold advection, translate to a stiff breeze
and gusty afternoon/evening winds. Look for sustained winds in
the teens with gusts into the 20s kts, higher over the peaks and
ridges.
For temperatures... a thermal trough featuring h850 temps in the
low to mid single digits drops into New England by the middle
of the day with high temperatures lucky to see 60 over the
northern/mountain zones between CAA, clouds, and showers. South
of the mountains, downsloping and sunshine help temperatures get
into to 60s to around 70, perhaps into the into the mid-70s
near the NH Seacoast. The low level gradient slackens quickly
Sunday night as low pressure tracks east away from our area, so
winds will drop off fairly quickly and some radiational cooling
will be had especially back over the Connecticut River Valley
with lows in the 40s and 50s.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
Perfect day on Monday if you like light winds, sunny skies, low
humidity and a bit below normal temperatures. Thereafter,
Tuesday should be a fine day also but with an increase in clouds
as a southern stream short wave trough approaches from the
southwest. Guidance consensus is that this southern stream wave
stays just far enough south to keep our forecast area mainly dry
through Tuesday night into Wednesday morning. Either way, a
northern stream short wave trough looks to approach on Wednesday
allowing for an increase in chances for showers and
thunderstorms during the afternoon and nighttime hours.
Unsettled weather is possible thereafter on occasion as
occasional short wave troughs possibly traverse through the
westerly/southwesterly flow aloft.
&&
.AVIATION /02Z SUNDAY THROUGH THURSDAY/...
Short Term...Widespread IFR or worse conditions continue today
as low pressure crosses. Conditions will gradually improve
tonight from west to east, but won`t improve over central Maine
until morning. Winds will increase out of the west tonight, then
become fairly stiff out of the northwest tomorrow with around
15G22kt for most sites. MVFR is likely to linger at HIE until
about midday.
Long Term...VFR Monday and Tuesday. Some low stratus possible
Tuesday night through Wednesday night ahead of a cold front
which may bring widespread showers later Wednesday and Wednesday
night.
&&
.MARINE...
Short Term...A wave of low pressure crosses the waters tonight
with seas building to near 5 ft over the outer waters, lasting
into tomorrow. A stiff northwest wind develops tomorrow with
gusts near 25 kts, relaxing late in the evening. Thus a SCA is
posted through tomorrow evening.
Long Term...Marginal SCA conditions possible Wednesday into
Thursday in association with cold frontal passage.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...None.
NH...None.
MARINE...Small Craft Advisory until 7 PM EDT Sunday for ANZ150-152-154.
&&
$$
NEAR TERM...Hanes
SHORT TERM...Casey
LONG TERM...Ekster
Area Forecast Discussion
National Weather Service Memphis TN
843 PM CDT Sat Aug 29 2020
.UPDATE...
Tranquil conditions are currently occurring across the Mid-South
at this time. However, showers and thunderstorms are developing
across Southern Missouri and Western Arkansas. This convection
will move into the Mid-South during the overnight hours. There
still remains some risk of storms becoming severe, but the threat
is not as high as what was thought earlier today as showers and
thunderstorms that occurred earlier this evening has created a
more stable airmass over the Mid-South. The expectation is that
the severe storms that are currently occurring across Western
Arkansas will dive southeast of the Mid-South within the area of
unstable air. Bigger threat may come from possible flash flooding
as convection moves over areas that have already received a lot of
rain over the last several days. Made some minor adjustments to
POPS earlier this evening. Current forecast has a good handle.
Will only update to add some mention of fog during the overnight
hours.
KRM
&&
.DISCUSSION... /issued 309 PM CDT Sat Aug 29 2020/
Its very hot and unstable across the Midsouth. Tropical moisture
remains in place with temperatures in the upper 80s to low 90s
across most of the area resulting in Heat indices near or above
100 degrees for much of the area.
Outflow from an MCS that peaked over Southeast Kansas early this
morning has moved across Arkansas sparking a line of
thunderstorms currently approaching East Arkansas. The airmass
ahead of this line is very unstable featuring surface based capes
over 5000 j/kg. Effective shear is not that impressive at 20-30
kts, but a favorable thermodynamic environment characterized by
strong instability and moderate mid- level lapse rates around
7-7.5 C/km should be sufficient for large hail and damaging winds.
Shear gets even weaker farther south and East so storms may
weaken some as they move into the Midsouth. Short term guidance
also suggests this will be the case. The HRRR weakens storms
substantially this afternoon but features another round of storms
after midnight tonight as a weak shortwave tracks out of East
Arkansas into West Tennessee and North Mississippi. It is also
possible that the storms currently moving into East Arkansas
limits overnight redevelopment resulting in lots of uncertainty
this evening and tonight.
A cold front associated with the shortwave is expected to stall
along the Tennessee Kentucky state line to near Little Rock
tonight. This feature will lift back to the North early Sunday in
response to a stronger shortwave approaching West Arkansas.
Widespread showers and thunderstorms are expected Sunday but we
will lack the instability we have in place today. Isolated
occurrences of damaging wind and large hail will be the primary
threat. The Storm Prediction Center has nearly all of the Midsouth
in a Marginal Risk for severe thunderstorms. High temperatures
Sunday are expected to range from around 80 North of the front in
far northern portions of the Midsouth to near 90 in the far
South.
Early next week we begin with northwest flow and a mean storm
track across Southern Arkansas into into Middle Mississippi.
Temperatures should rebound a bit across the northern half of the
Midsouth, but remain below 90 degrees area wide. As a result we
should see more instability and the possibility for some stronger
storms.
Late Monday through Midweek we will see a deep trough develop
over the Rockies resulting in a quick transition to Southwest flow
across the Southern Plains and over the Midsouth. This pattern
will remain in place through at least Wednesday night as a cutoff
low and associated longwave trough gradually shift East. Several
rounds of heavy rain and thunderstorms look likely through late
Wednesday or Thursday before the longwave trough shifts across the
area into Middle Tennessee and Alabama. This prolonged period of
rain and thunderstorms may result in flooding problems across the
Midsouth, especially across Northeastern Arkansas, the Missouri
bootheel and Northern portions of West Tennessee. Current expected
rainfall totals over the next 7 days range from over 6 inches in
far Northeast Arkansas to around 1-1.5 inches in Northeast
Mississippi.
A strong cold front associated with the longwave trough will usher
in cooler and drier conditions Friday into next weekend.
30
&&
.AVIATION...
Mainly VFR conds across the Mid-South this evening. A weak front
is draped across the Mid-South. Expect this to be a focus for
SHRA/TSRA activity for the period. CAMs have been all over the
place with timing of convection overnight into Sunday. Expect
SHRAs/TSRAs to start spreading into the area by midnight with KJBR
and KMEM having the best chances for activity. Confidence in
occurrence is moderate though confidence in timing is low. Should
be a good deal of low clouds and perhaps some light fog during
the morning hours before a return to VFR by afternoon. Winds will
be light through the period outside of TSRAs.
SJM
&&
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...None.
MO...None.
MS...None.
TN...None.
&&
$$
Area Forecast Discussion
National Weather Service Melbourne FL
1018 PM EDT Sat Aug 29 2020
.DISCUSSION...
Showers and thunderstorms moved generally east over east central
FL this afternoon reaching the coastal areas from Daytona Beach
to Sebastian. Then these moved over the Atlantic waters. By 9 pm,
an area stretching over Okeechobee county was still producing
moderate to heavy rain and lightning strikes as it was moving
east and it is expected to reach the coast in the next hour or so.
For the rest of the night, showers and storms moving off Lake
Okeechobee will affect Martin county and possibly reach the
nearshore waters. Additional activity moving from the west coast
of FL will reach Lake and Osceola counties after 930 pm. The HRRR
model seems to continue to be 1-2 hours late in their analysis but
it shows this west coast activity reaching our local forecast
area and moving it towards Volusia and northern Brevard. Forecast
had mention of this activity and so 30-40% chance of showers and
lightning storms remains through 2am and decreasing afterwards.
Lows expected to remain around the mid 70s.
&&
.AVIATION...
Lingering and additional storms this evening have triggered
amendments to TAFs. SHRA/TSRA possible for KLEE, KSFB and perhaps
KISM, KMCO and KDAB through 30/06z. Kept VCTS for KSUA but it
seems activity will remain to their south. VFR for the rest of the
terminals.
&&
.MARINE...
Showers and thunderstorms will exit the Atlantic waters east of
the Volusia and Brevard by around 1130 pm. We will continue to
monitor the showers and storms over Martin county moving east
that could reach the waters east of St Lucie and Martin counties.
Otherwise, southwest to west winds 5-15 kt. Seas 1-4 ft.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 74 87 74 91 / 40 70 30 70
MCO 75 88 75 92 / 40 60 20 70
MLB 75 89 75 91 / 50 60 20 60
VRB 74 90 74 91 / 50 60 20 60
LEE 75 86 75 91 / 50 70 30 70
SFB 75 88 75 93 / 40 70 30 70
ORL 76 88 75 92 / 40 70 20 70
FPR 74 91 74 92 / 50 60 20 60
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...None.
AM...None.
&&
$$
Negron/Sedlock/Leahy
Area Forecast Discussion
National Weather Service Springfield MO
604 PM CDT Sat Aug 29 2020
.SHORT TERM...(This evening through Sunday)
Issued at 238 PM CDT Sat Aug 29 2020
Tonight: Convection and the associated cold pool that produced a
swath of severe winds from southeast Kansas into southwest
Missouri has pushed an effective sfc front from southeast MO into
northern and west central AR. A subtle shortwave over eastern KS
will move east-southeast through the area this evening. Really
have low confidence, but there should be a small area of
convection that should develop somewhere over southern MO/northern
AR this evening along and just north of the front. With rich/deep
moisture w/PWATS well over 2 inches, convection will be very
efficient with high rainfall rate potential. WPC slight risk over
far southern MO looks good where 1-2 inch general rainfall looks
possible with higher amounts where storms can reside longer due to
training. Overall best chances look to be along/south of Highway
60. Not planning a flash flood watch with this forecast issuance
given still general dry soils, but next shift will monitor trends
closely.
Sunday: In general convection should push off to the south and be
more confined to the frontal boundary over AR, but some chances
will still exist, especially over far southern MO.
.LONG TERM...(Monday through Saturday) Issued at 238 PM CDT Sat
Aug 29 2020
Monday-Wednesday: Should be relatively quiet Monday. Some
elevated convection will be possible late Sunday night into Monday
morning favoring far southwest MO. Meanwhile a shortwave moving
from the Northern Plains into the Midwest will support a sfc cold
front that will eventually slow, stall, and weaken near or just
west of the area Monday night into Tuesday. Another upper level
system will shift into the central/southern Plains and the sfc
front will be the focus for additional showers/thunderstorms
Monday night into Tuesday with some heavy rain potential. Low
confidence exists beyond Tuesday in the placement of convective
driven features. Rain chances overall look higher during the
Tuesday-Wednesday period.
Thursday-Saturday: Good basic agreement with large scale features
with a longwave trough moving into the Midwest and Great Lakes
with a sfc cold front moving well south of the area. Should see
cooler weather late in the week Friday/Saturday.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 601 PM CDT Sat Aug 29 2020
HRRR continues to develop convection over southern Missouri
starting in an hour or two, but not convinced this will occur.
Morning convection pushed boundary and better instability further
south. Have not kept convection in the TAFS for now, and will
further monitor situation. May see some IFR conditions develop
later tonight as ceilings begin to lower across the area.
&&
.SGF WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&
$$
SHORT TERM...DSA
LONG TERM...DSA
AVIATION...Lindenberg
Area Forecast Discussion
National Weather Service Tallahassee FL
824 PM EDT Sat Aug 29 2020
.UPDATE...
No significant changes to the previous forecast appear necessary.
The focus for localized heavy rainfall tonight will shift to the
southeast big bend, particularly across portions of Dixie,
southeast Taylor, and southern Lafayette counties where SPC
mesoanalysis depicts precipitable water values in excess of 2.5
inches with fairly strong moisture transport into that vicinity.
The RAP currently analyzes an 850 mb jet of 35 knots in that area,
and radar shows convection with efficient, tropical rainfall
streaming into the area from Apalachee Bay. The low level jet is
forecast to weaken somewhat during the overnight hours, but this
is the area to watch for locally heavy rainfall amounts overnight.
&&
.PREV DISCUSSION [652 PM EDT]...
.NEAR TERM [Through Sunday]...
The wet pattern continues through Sunday with shortwave energy in
the southwest flow aloft acting on an air mass characterized by
Precipitable Water values over 2.0 inches. The heaviest precip will
shift to the Forgotten and Nature coasts into the Southeast FL Big
Bend this evening in association with the low-level jet/greatest
moisture transport. This is already evident on GOES-16 with cooling
cloud tops downstream over the Gulf of Mexico.
The western FL Panhandle received heavy precip this morning and
afternoon, with radar estimates in excess of 4 inches in spots.
Southport in Bay County has received 3.90 inches of rain in the past
24 hours!
Thunderstorms have also developed this afternoon west of the Flint
River Valley into the Wiregrass Region as well as in the Southeast
FL Big Bend, along differential heating boundaries due to the
clouds. An isolated wind gust to 40 mph is possible with steeper
low-level lapse rates and stronger environmental winds, especially
in the Southeast FL Big Bend.
Sunday will be similar to today with showers and thunderstorms
developing along the coast and spreading inland during the day.
Similar PoPs in the 60-80 pct range.
Localized flooding of low-lying/poor drainage areas will continue to
be a concern through this evening and again on Sunday, especially
where rainfall amounts near 2"/hr or 4-5" over several hours. Cannot
rule out an isolated flash flood as well.
High temperatures will remain below normal in the middle to upper
80s due to the clouds/precipitation.
.SHORT TERM [Sunday Night Through Monday Night]...
Deep moisture and a lingering mid-level trough will keep rain
chances elevated on Monday. However, with the low-level flow more
westerly, overall coverage may be slightly lower than Sunday.
Precipitable water will still be well over 2 inches, so locally
heavy rainfall will continue to be a possibility. The relatively
high PoPs and expected cloud cover will keep high temperatures in
the 80s.
.LONG TERM [Tuesday Through Saturday]...
The subtropical ridge will build back over the forecast area
starting on Tuesday. While deep moisture will remain in place
(PWAT over 2 inches), the synoptic forcing will be diminished,
with rain chances dropping back towards climatology for the low-
level flow regime. The lower rain coverage will also allow high
temperatures to push back into the lower 90s for the remainder of
the work week.
.AVIATION...
[Through 00Z Monday]
Widespread MVFR cigs for the with brief IFR possible around 12Z.
MVFR cigs will persist much of Sunday with a slow return to VFR
around 18Z. But there will be additional SHRA/TSRA overspreading
the terminals in the 12-18Z time frame, with brief MVFR possible
thru 00Z Monday. Southwest winds 5-10 knots through the period.
.MARINE...
Exercise caution conditions will continue into the evening as
moderate southwesterly flow continues. Conditions will gradually
improve on Sunday, but remain in the 10 to 15 knot range through
Monday. Lighter winds are expected by Tuesday into the middle of
the week.
.FIRE WEATHER...
Outside of low dispersions in the Florida Big Bend on Sunday,
there are no other fire weather concerns at least for the next
several days.
.HYDROLOGY...
Localized heavy rain has generally been confined to the coastal
portions of Bay and Walton County (as well as parts of Jackson
County today), with a few observations of 4+ inches. Rain chances
will remain high over the next few days with increased tropical
moisture and some high rain-rate tropical convection. Widespread
1-3 inch rainfall totals can be expected south of I-10 with
locally higher amounts. Localized poor-drainage flooding cannot
be ruled out into Monday in these areas. Three-day rainfall totals
will generally be under an inch north of the Florida border.
.SPOTTER INFORMATION STATEMENT...
Spotter activation is not requested. However, spotters are always
encouraged to safely report significant weather conditions when they
occur (while following all local, state, and CDC guidelines) by
calling the office or tweeting us @NWSTallahassee.
&&
.PRELIMINARY POINT TEMPS/POPS...
Tallahassee 74 86 73 87 74 / 30 70 30 70 20
Panama City 76 85 77 86 78 / 50 90 40 70 20
Dothan 74 88 73 87 73 / 30 70 20 70 20
Albany 75 89 74 89 75 / 30 60 20 70 20
Valdosta 73 86 73 87 73 / 20 50 20 70 10
Cross City 74 85 74 88 74 / 70 80 40 70 20
Apalachicola 76 84 76 86 77 / 50 80 50 70 20
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
FL...High Rip Current Risk through late Sunday night for Coastal Bay-
Coastal Gulf-South Walton.
GA...None.
AL...None.
GM...None.
&&
$$
UPDATE...DVD
NEAR TERM...LF
SHORT TERM...Camp
LONG TERM...Camp
AVIATION...LF
MARINE...Camp
FIRE WEATHER...LF
HYDROLOGY...Camp
Area Forecast Discussion
National Weather Service Tulsa OK
854 PM CDT Sat Aug 29 2020
.DISCUSSION...
It took most of the afternoon, but storms did eventually fire
along a westward advancing outflow impinging on a stalling front.
These boundaries acted to lift very unstable air and resulted in
some severe hail and wind reports. As a SWrly LLJ increases
tonight and interacts with these boundaries, a transition to
scattered to numerous elevated storms is expected, focusing across
northwest Arkansas and neighboring far eastern OK. Toward Sunday
morning, storm chances increase from the west as what is left from
an MCS developing from afternoon convection on the High Plains
moves into the region. The severe threat should wane with time and
transition to a heavy rain and flood threat. While the bulk of the
heavy rain thus far has fallen just east of the forecast area,
some pockets of heavy rain have fallen just south of FSM, with
scattered lighter amounts across NW AR. Depending on where and how
heavy the overnight storms are, the threat for flooding will
increase and thus the flash flood watch will be left in place.
Lacy
&&
.PREV DISCUSSION... /Issued 623 PM CDT Sat Aug 29 2020/
AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM/KROG.
Convective chances will mainly be in the 00-12z time frame across the
the AR sites and KMLC. Cigs will lower during the period to MVFR,
possibly to IFR with MVFR vsbys in TSRA. MVFR cigs expected mid to late
morning with VFR elements expected after 18-19z and prevailing for the
remainder of the period.
PREV DISCUSSION... /Issued 254 PM CDT Sat Aug 29 2020/
.Corrected WWA Headers...
DISCUSSION...
Cold front has continues to make steady progress south into this
afternoon and currently is situated along or just to the north of
I-40. A very unstable airmass resides south of the front with
MUCAPES analyzed 4000-5000 j/kg from southeast Ok into west
central AR. 12z OUN sounding did indicate a stout cap and thus far
it continues to hold. Still expect to see some storms develop
later this afternoon with coverage likely expanding during the
evening with strengthening low level flow, with the greatest
coverage ultimately becoming focused just north of the boundary.
Any more discrete storms initially will pose a large hail and
wind threat, with overall trend to more damaging winds through the
evening. Any more discrete cells that stay close to the boundary
could develop some low level rotation and a non-zero tornado
threat.
More significant threat however may be flash flooding as
substantial moisture transported north, potentially leading to
additional rounds of convection in the same areas through a good
part of tonight. Given the anomalously high moisture content
present, efficient rain producing storms with 1-2"/hour rain rates
could add up some hefty rain totals across parts of western AR and
possible adjacent areas of eastern OK. Have elected to add LeFlore
and Sequoyah counties to the existing watch with some support from
High-res models and given more aggressive southward push of the
front...but worth noting the HRRR continues to target NW AR more
aggressively. Expect most precip to shift out of the area Sunday
morning.
A relative lull Sunday appears likely, but the active pattern will
continue through mid week at least. Another surge of moisture
looks possible Sunday night into Monday with increasing rain and
thunderstorm chances. A more substantial and widespread rain event
may be shaping up Tuesday into Wednesday as a stronger wave
slowly moves across the southern plains. Additional flood
headlines will likely be needed for at least a part of the area by
then.
There remains considerable spread among the guidance on the
eventual progression of this system with the ECMWF trending even
more in keeping the low back to the west. Given this will stick
with NBM guidance through the extended period with low POPs
maintained through Friday.
&&
.PRELIMINARY POINT TEMPS/POPS...
TUL 70 88 71 90 / 30 20 40 60
FSM 73 87 72 90 / 80 70 50 70
MLC 73 89 72 88 / 40 50 30 70
BVO 68 86 68 87 / 30 20 40 60
FYV 70 82 67 87 / 80 70 50 70
BYV 69 82 67 89 / 80 60 60 70
MKO 71 86 71 87 / 50 50 40 70
MIO 68 84 68 88 / 40 20 50 70
F10 71 88 70 87 / 50 50 40 60
HHW 74 91 75 92 / 40 40 20 60
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...Flash Flood Watch until 5 AM CDT Sunday for OKZ072-076.
AR...Flash Flood Watch until 7 AM CDT Sunday for ARZ001-002-010-011-
019-020-029.
&&
$$
SHORT TERM...30