Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 07/20/24
Area Forecast Discussion
National Weather Service La Crosse WI
1101 PM CDT Fri Jul 19 2024
.KEY MESSAGES...
- Slightly below normal temperatures and largely diurnal
showers and storms are favored over the next week.
&&
.DISCUSSION...
Issued at 155 PM CDT Fri Jul 19 2024
18z WV satellite reveals an upper ridge over the western CONUS and
troughing in the east with resulting northwesterly flow aloft over
the CWA. This general pattern looks to remain in place through the
seven day forecast, leading to temperatures just a few degrees below
normal for July with highs mainly around 80 or in the lower 80s.
Additionally, while enough moisture is available at 850mb to lead to
potential convection each afternoon - with the exception of this
afternoon as warm 800-600mb temperatures look to keep a lid on
things - lack of robust moist advection and anemic shear profiles
suggest the risk for heavy rainfall and severe thunderstorms will be
very low. Indeed, LREF joint probabilities and CSU ML outlooks
continue to suggest scant risk for severe convection and modeled
PWATs remain under 1.5", not notable compared to model climatology.
Coverage of convection each afternoon and the potential for it to
persist into the nighttime hours will depend on timing of upper
impulses in the northwesterly flow aloft, with the slow moving
trough seen across guidance Tuesday into Wednesday the best bet for
persistent scattered convection.
&&
.AVIATION /06Z TAFS THROUGH 06Z SUNDAY/...
Issued at 1101 PM CDT Fri Jul 19 2024
MVFR to low-VFR cigs are likely across the region during the late
morning and early afternoon hours as the 20.02z RAP shows fairly
robust low-level saturation. With mid-level cooling expected,
this should aid in marginally better instability profiles during
the day tomorrow which will in turn help develop more
aggravated cumulus and showers and isolated storms as well with
diurnal heating. Consequently. decided to hold a VCSH at KRST to
address these diurnal showers and isolated storms. Coverage in
showers and storms will diminish during the evening hours. Winds
will remain around 5 kts through the TAF period from the
south/southwest.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
IA...None.
&&
$$
DISCUSSION...Ferguson
AVIATION...Naylor
Area Forecast Discussion
National Weather Service Dodge City KS
1100 PM CDT Fri Jul 19 2024
...Updated Aviation/Key Messages...
.KEY MESSAGES...
- Scattered showers and thunderstorms will continue through
Saturday morning.
- Afternoon temperatures will remain several degrees below
normal for the next several days.
&&
.DISCUSSION...
Issued at 208 PM CDT Fri Jul 19 2024
19Z observations and upper air analysis show a developing MCS
situated from far northeast Colorado through central Nebraska with
our first severe report of wind northwest of Wray, Colorado. This
line is in association with a 500 mb shortwave and we also have a
shortwave in north central Colorado which will also be a focus for
thunderstorm development this evening. At the surface a 1009 mb low
in southeast Colorado has led to a stronger pressure gradient in
southwest Kansas thus we`ve had stronger south to southwest winds.
Tonight the advertised MCS will enter into our northwest zones
(Syracuse to Hays) roughly around 00Z and quickly move south and
east through the rest of our area through midnight. HREF ensembles
have the greatest CAPE and theta e advection roughly along and west
of highway 83 between 8-11 pm and CAM models have latched on to the
stronger wind gusts in these areas where up to 70 mph is possible.
What CAMs have been struggling with is timing as the RAP has sped up
the prog of the line and the HRRR has slowed it down with the RRFS
being in the middle. At this stage the RRFS is showing the best
timing which would put the highest impacts between 7-11 pm. Hail
looks less of a threat with the large amounts of water loading in
the line plus the mode likely transitioned from supercell to squall
line that quarters would be the largest hail expected. The
exception could be areas along and north of I-70 (WaKeeney to Hays)
where we still could have some supercelluar characteristics to the
storms. After 10 pm the CAMs and HREF ensembles seem to agree the
instability should quickly diminish and the line will become more
general thunderstorms with pockets of heavy rain. Ability of
reaching 0.25 inch or more of rain looks good as we have widespread
60-80% chances for almost all of southwest Kansas with the exception
of our far southeast and isolated 1 inch or more amounts are at 20-
30% for areas west of a Hays to Dodge City line.
Saturday the vort max should depart into central Oklahoma and DNVA
will lead to breaks in the clouds by late morning. Post MCS
environment should be worked over much of the morning and combining
with northerly winds we should see storm chances low (>20%) through
the early afternoon. Temperatures should be refreshing with highs
in the low 80s. By late afternoon HREF ensembles and CAMs have a
developing vort max and increasing 700-850 frontogenesis roughly for
areas along and east of highway 83. 20-40% POPs are placed in these
areas as the storm mode should widely scattered in nature. Currently
there is no severe risk for Saturday but with CAPE values ~1000
J/kg, higher theta e values, and 0-6 km bulk shear values at ~30 kts
by 7 pm near Pratt...we may see a marginal risk introduced for some
isolated hail up to quarters and 60 mph gusts.
Early next week ensemble clusters show the upper air pattern
continuing to have a long wave trough over the central and eastern
CONUS with the 594 dm anticyclone situated over Nevada. This will
keep northwest flow in place for early next week and 850 mb temps in
the 17-20 (C) range. Mean high temperatures will be in the lower
80s for Monday and Tuesday. With northwest flow in place we should
expect periodic shortwaves to move through the afternoon and evening
hours which will provide 20-30 POPs in southwest Kansas during this
time. Ensembles are trending in the day 5-7 range with the 594 dm
high moving eastward and spreading further into the Rockies. This
will both start to increase our temperatures and actively shut off
the rain chances.
&&
.AVIATION /06Z TAFS THROUGH 06Z SUNDAY/...
Issued at 1100 PM CDT Fri Jul 19 2024
Outside of any convective influences, VFR will continue through
this TAF cycle, with a mix of mid and high clouds. Radar at
04z depicted scattered thunderstorms in NW KS moving due south,
and these will spread south through SW KS through 12z Sat.
Confidence of direct convective impacts at any airport are very
low, so kept only some VCTS/CB mentions for now overnight. Winds
will remain light outside of convection, where strong erratic
outflows are possible. VFR and dry weather will prevail
Saturday, with light winds trending N/NEly.
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
DISCUSSION...Tatro
AVIATION...Turner
Forecast Discussion at weather.gov/mqt.
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...None.
WI...None.
MARINE...Small Craft Advisory until 8 PM CDT this evening for LSZ140.
&&
$$
DISCUSSION...Britt
AVIATION...Huyck
MARINE...Britt
Area Forecast Discussion
National Weather Service Hastings NE
603 PM CDT Fri Jul 19 2024
.KEY MESSAGES...
- Slight to Enhanced risk for severe thunderstorms this
afternoon and early evening, with overall greatest risk
focused SW of the Tri-Cities.
- Additional off and on scattered showers and thunderstorms will
be possible overnight into Saturday AM for parts of the area
- Periodic small chances (10-40%) for mostly non-severe
thunderstorms will be possible Saturday afternoon into early
next week. Temperatures will also remain below normal through
at least Tuesday.
- Warmer temperatures (80s to lower 90s) and dry weather are
anticipated for the latter half of next week.
&&
.DISCUSSION...
Issued at 314 PM CDT Fri Jul 19 2024
Main risk for severe weather has sped up compared to
expectations 12-24 hrs ago, thanks in large part to outflow from
last night`s thunderstorms over northern Nebraska. The earlier
arrival will likely lead to smaller area of concern given less
time for destabilization. Per latest mesoanalysis, greatest
concern will be SW of the Tri-Cities where they managed to warm
into the low 90s amidst dew points in the mid 60s. Combination
of strong instability and seasonably strong effective shear
40-45kt (despite overall weak mid level flow) is supporting
ongoing supercell just NW of Cambridge. Latest experimental WoFS
supports the conceptual model of upscale growth over the next
hr, which will only incr the wind potential for Furnas Co down
through Phillips and Rooks over the next 1-2 hrs. Very steep low
level lapse rates near 9 C/km, sfc T-Td depressions around 30
degrees, and DCAPE values in excess of 1000 J/kg ahead of the
convection argues for decent potential of sig severe wind gusts
of 70-80 MPH within this narrow corridor. Contrast the hot/humid
SW zones with the Highway 81 corridor having air temps in the
70s and Tds in the 50s and it`s pretty easy to see why severe
threat should be lower in this direction. Can`t completely rule
out a marginally severe storm, but weaker lapse rates should
really limit this to iso and brief.
With the earlier start time that should give a large chunk of
the forecast area more dryness for the evening hours. Additional
off and on scattered showers and non-severe thunderstorms will
be possible overnight as a vort lobe, perhaps convectively
enhanced by ongoing convection, pivots over the area within very
weak upper flow. Continued deep layer moisture convergence will
present at least an isolated chance pretty much anywhere, but
the scattered coverage should favor more towards SE half.
As for the weekend, think there will be chances for iso
shwrs/storms both afternoons, though this risk will really
depend on how ongoing convection plays out as that will
determine how far south the moisture/instability is pushed out.
Tend to think the slight chcs will favor E and S portions of the
forecast area, but no one will see a complete washout by any
means. The broad troughing aloft and NErly low level flow will
lead to seasonably cool/less humid conditions for the weekend
with highs in the 70s/80s and lows in the upper 50s to lower
60s. More opportunities to open up the windows at night!
Heading into next week, NNW upper flow will continue for
several days, steering multiple weak disturbances across the
local area along with helping to maintain seasonably cool
temperatures (70s and lower 80s) a couple more days. Later in
the week, the upper level ridge across the western interior is
forecast to expand eastward, helping bump up temperatures to
near and eventually above climatology by the end of the week in
addition to promoting a return to less unsettled (dry) weather
across the local area.
&&
.AVIATION /00Z TAFS THROUGH 00Z SUNDAY/...
Issued at 552 PM CDT Fri Jul 19 2024
Lots of uncertainty for tonight`s convection as models are all
over for TSRA placement and timing. The 21z HRRR is initializing
the best with what is currently on radar. The 21z HRRR brings in
some convection overnight and lingers it over GRI. Debated
about a TEMPO for GRI, but decided against one as none of the
other models have anything similar to the HRRR, will AMD as
needed.Winds will become northerly tomorrow morning and EAR is
looking like gusts in the upper teens currently. &&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...None.
KS...None.
&&
$$
DISCUSSION...Thies
AVIATION...Beda
Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
958 PM EDT Fri Jul 19 2024
.SYNOPSIS...
A nearly stationary front will meander across our region
through the first half of next week providing a focus for
above-normal chances of mainly afternoon and evening showers and
thunderstorms. Temperatures will be near normal or just a bit
cooler than normal.
&&
.NEAR TERM /THROUGH SATURDAY/...
As of 1000 PM EDT Friday: A nice meso-low developed over Chester
County in SC and is lifting northward this evening. The "strongest"
shower and thunderstorm activity is within the vicinity of this meso-
low, so some gusty winds cannot be ruled out with this feature.
Weaker shower activity is noted lifting northeast across the rest
of the forecast area this evening. The main concern with leftover
convection will continue to be locally heavy rainfall. The severe
risk, which was minimal at best to begin with, is over thanks to the
loss of daytime heating. Main changes needed this update were tweaks
to PoPs (and thunder) through the period based on the latest high-
res guidance. Otherwise, no other major changes were needed.
Broad upper trofing to our north will flatten/deamplify tonight as
broad upper ridging persists to our west and to our east. A weak
upper shortwave will lift over our area from the SW tonight
providing some amount of additional support for scattered showers.
At the sfc, we will remain sandwiched between weakening high
pressure to our NW and the western extent of the dominate Bermuda
High to our SE. A weak low pressure center will move off the NC
Coast and along what`s left of a stalled frontal boundary. With
deeper moisture lingering over our region, we can expect showers to
linger into the overnight hours. Lows overnight should be near
normal for mid-July, with areas of fog/low stratus likely developing
around daybreak Saturday.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
As of 130 PM Fri: Not really any meaningful change in the forcing
regime across the region thru Monday. Upper troughing generally will
persist over the lower Mississippi Valley; as shortwave fills and/or
advects toward the Mid-Atlantic coast late Sat into early Sun, weak
height rises over the Southeast are soon negated by upper low
swinging south out of the Missouri Valley. The seasonably diffuse
boundary or convergence zone remaining from the central Gulf Coast to
the VA/NC coast won`t become any better defined, but could pivot
and/or shift slightly further north by Monday. Its presence near the
region, combined with relatively deep SW flow and above-normal PWAT
values, suggest elevated precip chances each day: basically likely
for most of the Piedmont and categorical for the mountains. Any
northward movement in the boundary would probably result in a slight
uptick in daily dewpoints and PWAT, although only a minimal change in
those fields is depicted in synoptic guidance, so we cannot say with
much confidence that will actually increase precip coverage.
Mean cloud-layer flow and deep layer shear are nonzero but small, so
storms are likely to move only slowly, and could organize loosely
into clusters. Widespread cloud cover should limit diurnal temps,
keeping them 2-3 degrees below normal, and so diurnal CAPE should be
on the low side for the season as well. Sfc-midlevel delta-theta-e
values also will be muted on account of the moist profiles.
Altogether main impact weather for the short term looks to remain
locally heavy rainfall particularly where cells train.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
As of 200 PM Fri: On a large scale, the overall setup remains in
place through late next week: deep Bermuda anticyclone to our east,
persistent trough centered in the mid-Mississippi Valley, and broad,
ill-defined frontal zone in between, likely remaining just to our
northwest. The Bermuda high does look to strengthen Tue-Wed, and
that would seem only to push the front northward. However, by then
some guidance members depict the upper low or another embedded
disturbance moving toward the NE CONUS and driving the sfc boundary
eastward thru the Mid-Atlantic. This could allow the peak convergence
zone to shift back south into our area as soon as late Thursday, but
if so it would probably stall SE of the Appalachians to end the week.
Altogether, without a major pattern shift indicated by any of the
available guidance sources, we can`t confidently advertise a
significant trend in temps or precip chances. Daytime temps will
remain a little below normal due to cloud cover; PoPs diminish
slightly by Day 6-7 simply due to lower confidence with increasing
forecast range. Main concern will be slow-moving or training storms
producing locally heavy rainfall, and potential for deteriorating
antecedent conditions following what will by then be almost a week
under the influence of this moist and somewhat active pattern.
&&
.AVIATION /02Z SATURDAY THROUGH WEDNESDAY/...
At KCLT and elsewhere: Complex 00Z TAF period on board thanks to a
stationary boundary over the western Carolinas. Rounds of widespread
SHRA will continue across the terminals through late this evening,
with some terminals seeing a resurgence overnight. Have a TEMPO at
KCLT for SHRA this evening, with prevailing SHRA elsewhere through
the evening hours. Plentiful low-level moisture will allow CIGS to
gradually lower this evening into the overnight hours, with IFR to
MVFR cigs developing around/after midnight, lingering through
daybreak. Cigs will gradually improve to MVFR levels by the mid-
morning to early afternoon. High-end MVFR to low-end VFR should
stick around through late Saturday afternoon before VFR returns
everywhere early Saturday evening. Patchy IFR to MVFR fog will also
be possible overnight into daybreak Saturday, especially across
terminals that received heavy rainfall. Vsbys should gradually
improve to VFR levels around/after sunrise. Winds will be calm to
light and VRB this evening into tonight across the terminals. Winds
will pick up out of the SW Saturday morning. Winds will gradually
increase in speed, ranging from 4-7 kts, while remaining SW
throughout the day Saturday. Shower and thunderstorm coverage looks
to be lower Saturday afternoon/evening but went ahead and added
PROB30s across all terminals to account for TSRA. Confidence on the
timing of TSRA and SHRA through the period will be low as high-res
models are not in great agreement regarding the coverage/timing of
activity through the 00Z TAF period. The HRRR is more bullish with
the amount of convection on Saturday while the NAMNest shows less
activity overall.
Outlook: Expect scattered to numerous showers and thunderstorms each
afternoon/evening through early next week. Morning fog/low stratus
will be possible each day, especially in the mountain valleys and
across areas that received heavy rainfall the day prior.
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...None.
NC...None.
SC...None.
&&
$$
SYNOPSIS...Wimberley
NEAR TERM...AR/JPT
SHORT TERM...Wimberley
LONG TERM...Wimberley
AVIATION...AR
Area Forecast Discussion
National Weather Service North Platte NE
634 PM CDT Fri Jul 19 2024
.KEY MESSAGES...
- Scattered severe storms are possible late this afternoon and
tonight. The hazards are damaging winds, large hail and
locally heavy rainfall which may cause flooding in some areas.
The risk of a tornado is low but not zero.
- Isolated thunderstorms are possible Saturday through Monday.
The risk of severe storms is low.
- Dry weather and warming temperatures are expected Tuesday
through Friday.
&&
.SHORT TERM /THROUGH SATURDAY NIGHT/...
Issued at 315 PM CDT Fri Jul 19 2024
A plume of subtropical moisture will remain across wrn/ncntl
Nebraska this afternoon and this evening. PWAT values of 1.25 to
1.50 inches will be in place. Modest drying is expected after
midnight. Thereafter, PWAT falls to an inch or less Saturday and
Saturday night. This drying will be accompanied by cooler air aloft
with h700mb temperatures falling to 5 to 9 C.
Severe weather chances this afternoon and this evening hinge on an
increase in wind speeds aloft, most notably h500mb winds
increasing from 30kt to around 40kt. Warm air advection moving
north through KS is modest and being intercepted by ongoing
storms but warmer air aloft is lurking to the west across the
high plains of Colo and WY. The first round of 2 or perhaps 3
rounds of thunderstorms moved through wrn/ncntl Nebraska this
afternoon. A second round is attempting to organize across SD
and WY. Given that satellite shows the dynamics extending north
into wrn SD/nern WY, a second round of late afternoon/evening
storms seems likely. The very dry air across the high plains
make significant wind gusts the primary concern. High PWAT and
the potential for cell mergers, back-building and repeat storms
support the WPC excessive rainfall outlook highlighting swrn and
ncntl Nebraska for flood potential.
A third round of thunderstorms is possible late this evening and
overnight as temperatures aloft cool but the latest NAM12, HREF and
NAMnest are quiet about this. The RAP model supports scattered
storms late tonight. The model soundings show abundant CAPE, around
2500 J/KG but the winds aloft are backing with height which might
favor back-building and excessive rainfall vs severe weather.
Nonetheless, satellite and radar shows storms firing across ern MT
this afternoon and this disturbance will likely move south through
Nebraska overnight.
The peak heating period from 4 pm to 9 pm today would appear to be
the most favored time for severe weather but not all models agree on
this. The forecast leans toward the more aggressive NAMnest which
shows scattered storms developing late this afternoon into the
evening.
Isolated rain chances are in place Saturday, mainly for daytime
heating. The forecast is dry Saturday night. It is worth noting the
jet stream will shift west running north and south along the Laramie
and Front ranges Saturday. It is in this area the models show storms
forming. This activity would likely be steered south southeast and
remain west of wrn/ncntl Nebraska.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
Issued at 315 PM CDT Fri Jul 19 2024
Isolated to low-end chance POPs are in place Sunday and Monday.
Winds aloft at h500-300mb will be weak, generally less than
30kts and the risk of severe storms would likely remain low.
The forecast is dry Tuesday and beyond for a few reasons.
Upper level moisture in the models will be spartan and temperatures
aloft will be on the rise. Wrn/ncntl Nebraska will remain in
northwest flow which could support storm development off the Black
Hills or the Big Horns but the models suggest moisture will be too
limited.
&&
.AVIATION /00Z TAFS THROUGH 00Z SUNDAY/...
Issued at 634 PM CDT Fri Jul 19 2024
Isolated thunderstorms will move south this evening and may
affect the KLBF terminal between 01Z-02Z. After 06Z, stratus
will begin to develop and spread westward and affect the KLBF
terminal by 09Z and the KVTN terminal by 11Z. Ceilings should
range near OVC012, but will have the potential to fall to IFR
below OVC010. The stratus should become scattered after 15Z,
with VFR ceilings expected through the end of the TAF period.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SHORT TERM...CDC
LONG TERM...CDC
AVIATION...Roberg
Area Forecast Discussion
National Weather Service Medford OR
718 PM PDT Fri Jul 19 2024
.UPDATE...Updated the aviation section.
&&
.AVIATION...20/00Z TAFS...Along the coast, conditions are VFR
early this evening. Marine stratus will form again this evening and
move into the coastal valleys overnight, resulting in IFR
conditions. The IFR is expected to linger longer in the morning than
it did on Friday, and return earlier...(around 00Z at North Bend)
mainly by the start of Saturday evening.
Inland, VFR conditions will prevail through Saturday afternoon, with
an exception. The exception will be in the vicinity of the Trail
fire and various other fires in the vicinity of the Trail Fire. In
eastern Douglas County and across northern portions of Klamath and
Lake counties, visibility could end up between 3-5 miles. Visibility
could also be reduced southeast of the fires into northeast Jackson
County and the remainder of Klamath County, including possibly down
into Klamath Falls late tonight resulting in MVFR visibility.
A slight chance to chance of thunderstorms will develop across the
area Saturday evening and continue Saturday night. -DW
&&
.MARINE...Updated 800 PM Friday, July 19, 2024...A thermal trough
will return tonight into Saturday, then strengthening Sunday into
Tuesday. Moderate north winds and steep seas are expected south of
Port Orford beginning tonight and lasting through Saturday. Expect
conditions hazardous to small craft to expand across a larger area
on Sunday, then stronger, gale force winds are possible Monday
afternoon through Tuesday. -Spilde/DW
&&
.PREV DISCUSSION... /Issued 242 PM PDT Fri Jul 19 2024/
DISCUSSION...A high amplitude ridge remains in control of the
western third of the country, and with the trough to the northwest
over the Gulf of Alaska, this places southern Oregon and far
northern California under relatively dry and stable southwest
flow aloft. Meanwhile, a thermal trough has developed over
central California.
A shortwave impulse now lies along the southern periphery of the
trough to our southwest, and this feature will approach the area
through the day Saturday. The southerly flow ahead of the wave
will push this hot air into our area Saturday, resulting in very
warm temperatures across much of the inland areas. Most inland
valleys both east and west of the Cascades will easily reach upper
90s to low 100s for the daily high. This will be just enough
above normal to trigger Heat Risk for northern California and the
East Side, so Heat Advisories have been issued for those areas
for Saturday.
The shortwave will also provide instability and additional
moisture, while also acting is a sufficient lift mechanism to
produce a widespread slight chance to chance (generally 10-30%)
for thunderstorms Saturday into Sunday, including during the
overnight hours as the wave tracks through overhead. This event
looks very similar to the one from earlier this week, both in
overall pattern and in the dry lower layers of the atmosphere, so
we are concerned about lighting and gusty outflow winds once again,
especially given that any storms that develop will produce very
little, if any, precipitation. The focus of convection concerns
will shift to the East Side on Sunday as the wave exits the
region.
For the remainder of the week, the pattern will very slowly
progress to the east, with the Gulf of Alaska trough gradually
moving inland into Canada and Washington. As a result, we are
expecting temperatures to "cool" slightly, returning to near
normal values for this time of year, with relatively dry west to
southwest flow continuing through the week. -BPN
&&
.FIRE WEATHER...Issued 200 PM Friday July 19, 2024...
A dry and stable southwest flow continues into this evening with no
concerns for thunderstorms. However, afternoon relative humidities
will trend lower for most interior locations with values in the
single digits for portions of the East Side along with the typical
gusty afternoon and early evening breezes. This will result in near
critical conditions for portions of Fire zones 624, 625 and 285, but
were not expecting the combination of wind and RH to result in Red
Flag conditions.
The other concern for those involved in air attack on the various
fires in our area will be visibilities lowering to 3-4sm in the
vicinity of the Trail Fire and surrounding complexes near the Trail
Fire in eastern Douglas County. The latest run of the HRRR smoke
fields show the smoke being transported east to southeast late this
afternoon and evening. However there are fires up in Lane County
that will get transported into eastern Douglas County, so we may not
see any improvement through tonight. Meanwhile, smoke from the Trail
and other fires in eastern Douglas County will push southeast into
Klamath County late this afternoon, then into Klamath Falls proper
tonight, and visibility could be reduced to 4-6sm. Tonight, as the
mixing height decreases, the smoke will settle and be confined to
around the perimeter of the fires resulting in MVFR visibility
between 3-5sm. However, a northeast drainage winds could bring smoke
towards Medford resulting in visibility lowering to 5sm northeast of
the Medford Airport late this evening and tonight.
There is now an increased concern for thunderstorm this weekend.
Saturday, an upper trough will move up from the south just off the
California coast and could tap into some monsoonal moisture with a
southeast flow aloft. At the same time, there`s good agreement, the
upper trough will become negatively tilted Saturday afternoon into
Saturday night. Based in part on pattern recognition, this could be
problematic in that we could see storms break out mid to late
Saturday afternoon in portions of northern California, east of the
Cascades, and some could slip into the southern portions of Fire
zones 619, 620 and 621 late Saturday afternoon due to a stronger
flow aloft which could allow storms to come off the mountains and
move north into the lower elevations.
Saturday night, the axis of the upper trough is still south of our
area which heightens the concern for nocturnal storms west of the
Cascades, and portions of the eastside in Oregon Saturday night.
Many times the models will not show signs of unstable conditions
with this type of pattern, then the next thing you know something
breaks out of nowhere. The pattern that is setting up is one where
the instability is elevated, and thus the convection will be
elevated as well. The most recent data points to a heighten concern
for nocturnal storms along and west of the Cascades Saturday night
into Sunday morning. This has lead to a higher confidence for a Fire
Weather Watch for the Cascades west for abundant lightning on dry
fuels and a Fire Weather Watch has been issued. Keep in mind given
how dry and hot it has been for the interior and near the coast,
that lightning efficiency is high to very high for fire starts. Also
gusty and erratic winds are a concern which could further increase
fire activity on existing fires. Some of the high res guidance are
showing some reflectivity, and PWATS are higher, therefore there we
could see some rain out of these storms that could reach the ground,
but it will not provide much help in preventing new starts given how
dry and hot it`s been. Even though the Fire Weather Watch is for the
Cascades west, that does not mean the eastside will be in the free
and clear. There is concern for nocturnal storms in portions of Fire
zone 624 Saturday night, however the confidence is not as high for
isolated to scattered storms, so they were left out of the watch for
now, but this could change should future data shows evidence to the
contrary. With all that said, this is not a slam dunk, but at the
same time it cannot be discounted.
The upper trough axis shifts north during the day Sunday. Any threat
for storms could be confined to the early morning hours over the
northwest part of our area, then shifting north late Sunday morning
through Sunday afternoon with a drier and stable southwest flow
moving into the area. The exception could be in portions of Fire
zone 623, 624, 625 and along the Warners in Fire Zone 285 where
isolated storms are possible late Sunday afternoon.
Monday, a dry and stable southwest flow will set up with any chance
for storms shifting east and northeast of our area. It will be
cooler with gusty afternoon and early evening breezes for the
interior westside valleys and east of the Cascades.
The rest of next week is pointing towards dry weather, with ridging
nudging back into the area. This will result in afternoon
temperatures trending upwards from Tuesday and beyond. Also the
concern will shift towards moderate to locally poor overnight
recoveries for the mid slopes and ridges in southwest Oregon and
western Fire zone 280, and the typical gusty afternoon and early
evening breezes for the interior westside valleys and east of the
Cascades with low afternoon RH`s. -Petrucelli
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...Heat Advisory from 11 AM to 11 PM PDT Saturday for ORZ029>031.
Fire Weather Watch from Saturday afternoon through Sunday
morning for ORZ615>620-622-623.
CA...Heat Advisory from 11 AM to 11 PM PDT Saturday for CAZ081>085.
PACIFIC COASTAL WATERS...Small Craft Advisory from 2 AM to 11 PM PDT Saturday for PZZ356-
376.
Gale Watch from Monday afternoon through Tuesday evening for
PZZ356-376.
&&
$$
Area Forecast Discussion
National Weather Service Melbourne FL
1050 PM EDT Fri Jul 19 2024
...New UPDATE...
.UPDATE...
Issued at 1039 PM EDT Fri Jul 19 2024
Most of today`s lightning storms have finally dissipated or moved
out of east central Florida, but a few linger on from Daytona to
Leesburg as this line pushes north. Some isolated storms have
also found their way from Palm Beach County into Martin County and
the adjacent Atlantic waters. Most storm gusts this evening were
40 mph or less, one storm did manage to produce dime-sized hail in
Downtown Leesburg, according to a trained spotter. The primary
storm hazard was once again frequent to excessive cloud to ground
lightning.
Updated PoPs and skies a few times through the evening based on
trends and latest HRRR guidance which did a fairly good job,
keeping rain chances around 50 pct along and north of I-4 a few
hours later, and lowering chances to the south an our or two
earlier, than previously advertised. The rest of the forecast
remains in good shape with no changes needed. Most of ECFL has
already quieted down for the night, and those last few storms are
forecast to clear out in the next hour or two. Temperatures settle
to mainly the M-U70s, under partly to mostly cloudy skies that`ll
clear through the night, with light southeasterly winds.
&&
.AVIATION...
(00Z TAFs)
Issued at 751 PM EDT Fri Jul 19 2024
VFR conditions outside of convection. Line of +TSRA over KLEE
will push north over the next couple hours with TS diminishing by
around 02Z, but -RA could linger through 05Z and might even creep
back east towards the I-4 terminals as well. VFR conditions
prevail overnight and through Saturday afternoon, then rinse and
repeat with afternoon thunderstorms. ISO TSRA/SHRA forecast to
start developing near and along the ECSB INVOF the coastal
terminals around 17Z-18Z then push inland. TSRA/SHRA becomes SCT-
NUM as activity approaches the inland terminals around 20Z, with
TEMPOs likely needed in upcoming packages. Generally light SE
winds give way to the sea breeze and outflow from storms.
&&
.MARINE...
Issued at 235 PM EDT Fri Jul 19 2024
Generally good boating conditions will continue through at least
early next week as the weather pattern remains stagnant. A high
pressure ridge axis will remain near or just north of the local
Atlantic, promoting 5-12 KT S/SE winds that will enhance to 10-15 KT
along the coast and become ESE in the afternoon hours. Isolated to
scattered showers and a few storms are still forecast primarily in
the overnight and morning hours. Seas 2-3 FT, occasionally up to 4
FT well offshore.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 76 93 76 93 / 30 70 40 50
MCO 77 95 77 95 / 20 80 30 60
MLB 77 91 77 91 / 10 60 20 50
VRB 77 92 76 93 / 10 50 10 40
LEE 77 94 77 95 / 60 80 50 60
SFB 77 95 77 95 / 30 80 40 60
ORL 77 95 77 95 / 30 80 30 60
FPR 76 92 76 92 / 10 50 10 40
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...None.
AM...None.
&&
$$
UPDATE...Haley
AVIATION...Haley
Area Forecast Discussion
National Weather Service Spokane WA
412 PM PDT Fri Jul 19 2024
.SYNOPSIS...
Strong high pressure will continue to amplify, bringing
increasing heat that will peak on Sunday, with widespread
temperatures in the 100s and some areas reaching 110 or higher. A
weather system will bring lower temperatures beginning next
Tuesday, but will also bring increased winds, which, combined with
dry weather, will bring increased fire risk.
.DISCUSSION
Today through Sunday Night: Excessive heat continues to b e of
major concern, as temperatures will continue to increase past
already dangerous levels. Models are in good agreement that a
strong upper-level ridge will build into the area on Saturday and
remain potent on Sunday, with the ridge axis stalled over the area
during the weekend before slowly beginning to shift east into
Monday. Initial warming will be due to subsidence from the ridge,
but upper-level flow will become southerly on the back side of the
ridge as it shifts east, with 850mb temperatures forecast to
reach as high as 32C on Sunday. The HRRR does show smoke from
Oregon drifting northward, which could abate temperatures
slightly, but with little-to-no forecast cloud cover through the
weekend, surface heating will be extreme. Heat Advisories are
currently in effect through 11 am PDT Saturday, with Excessive
Heat Warnings in effect from 11 am PDT Saturday through 8 PM PDT
Monday. Vulnerable populations should plan well in advance to find
cooling, and animals should be brought indoors if possible or
given water, shade, and fans otherwise.
Monday through Thursday: On Monday, the 300mb low will continue
to strengthen in the Gulf of Alaska and reach farther south,
bringing west-to-southwest flow that will bring an embedded
shortwave into the region and allow the ridge to begin to break
down, bringing a bit lower surface temperatures but increasing
wind, especially central WA. Increasing winds in combination with
extremely dry air will be of concern for any existing fires.
Forecast CAPE (100-200 J/kg), positive vorticity advection (lift),
200-850mb shear, and elevated moisture raises concern for high-
based thunderstorms capable of dry lightning Monday.
Models indicate dry and breezy conditions will continue through next
week despite cooler temperatures Tuesday onward with high
temperatures in the upper 80s to mid 90s. Increased surface winds
in combination with continued extremely dry air will create
multiple days of elevated to critical fire weather conditions,
which will be closely monitored in the coming days. /Cooke
&&
.AVIATION...
00Z TAFS: A building upper level ridge will allow VFR conditions
to continue through the period. The only exception will be some
hazy conditions from smoke near wildfires that may reduce
visibilities along Lake Chelan, and the Methow Valley.
FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS:
With the exception of smoke near wildfires confidence is high for
continued VFR conditions.
-----------------------
Confidence descriptors:
Low - Less than a 30 percent chance
Moderate - 30 to 70 percent chance
High - Greater than a 70 percent chance
For additional probabilistic information for NWS Spokane airports,
please refer to the Aviation Dashboard on our webpage:
https:/www.weather.gov/otx/avndashboard
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 64 101 67 106 70 102 / 0 0 0 0 0 0
Coeur d`Alene 62 99 66 103 69 102 / 0 0 0 0 0 0
Pullman 59 97 63 102 63 98 / 0 0 0 0 0 0
Lewiston 71 107 72 112 75 107 / 0 0 0 0 0 0
Colville 53 99 56 104 60 101 / 0 0 0 0 0 0
Sandpoint 57 96 62 101 64 100 / 0 0 0 0 0 0
Kellogg 68 97 71 99 73 101 / 0 0 0 0 0 0
Moses Lake 61 102 65 109 68 102 / 0 0 0 0 10 10
Wenatchee 69 102 74 107 75 103 / 0 0 0 0 0 0
Omak 64 104 68 110 74 108 / 0 0 0 0 0 0
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Heat Advisory until 11 AM PDT Saturday for Central Panhandle
Mountains-Coeur d`Alene Area-Idaho Palouse-Lewis and
Southern Nez Perce Counties-Lewiston Area-Northern
Panhandle.
Excessive Heat Warning from 11 AM Saturday to 8 PM PDT Monday
for Central Panhandle Mountains-Coeur d`Alene Area-Idaho
Palouse-Lewis and Southern Nez Perce Counties-Lewiston Area-
Northern Panhandle.
WA...Heat Advisory until 11 AM PDT Saturday for Central Chelan County-
Lower Garfield and Asotin Counties-Moses Lake Area-
Northeast Blue Mountains-Northeast Mountains-Okanogan
Highlands-Okanogan Valley-Spokane Area-Upper Columbia Basin-
Washington Palouse-Waterville Plateau-Wenatchee Area-
Western Okanogan County.
Excessive Heat Warning from 11 AM Saturday to 8 PM PDT Monday
for Central Chelan County-Lower Garfield and Asotin
Counties-Moses Lake Area-Northeast Blue Mountains-Northeast
Mountains-Okanogan Highlands-Okanogan Valley-Spokane Area-
Upper Columbia Basin-Washington Palouse-Waterville Plateau-
Wenatchee Area-Western Okanogan County.
Fire Weather Watch from Sunday afternoon through Sunday evening
for East Portion of North Cascades National Park/Lake
Chelan National Recreation Area (Zone 697)-East Washington
Central Cascades (Zone 696)-East Washington North Cascades
(Zone 698)-Foothills of Central Washington Cascades (Zone
705)-Methow Valley (Zone 704).
Heat Advisory from 11 AM Saturday to 8 PM PDT Monday for Western
Chelan County.
&&
$$
Area Forecast Discussion
National Weather Service Raleigh NC
1016 PM EDT Fri Jul 19 2024
.SYNOPSIS...
A series of convectively-amplified disturbances in moist,
southwesterly flow aloft will overspread and interact with a surface
front that will remain nearly stationary over central NC through the
weekend.
&&
.NEAR TERM /THROUGH TONIGHT/...
As of 1015 PM Friday...
Amid swly flow downstream of a shortwave perturbation that will
pivot from sern MO/nrn AR newd and across the mid-South, a series of
convectively-amplified disturbances will be directed from the lwr MS
and TN Valleys to the srn Middle Atlantic. The most notable and
probably influential of these features for the sensible weather in
cntl NC was well-defined in regional radar data over n-cntl SC this
evening, including in KCAE velocity data that depict a deep
circulation from around 3 to 25 thousand ft ARL in wrn Chester and
Fairfield Co. SC. This feature will continue to move generally newd
and across cntl NC overnight. As it does so, it will encounter an
environment characterized by only weak instability from widespread
outflow and surface cooling from prior convection and otherwise
weak, 5-5.5 C/km lapse rates upward through 500 mb. As such, it
seems most likely that a mix of stratiform rain immediately
surrounding the approaching MCV, and occasional weak cellular
development preceding it, will spread newd into/across cntl NC
overnight. Hourly rainfall amounts in the stratiform rain have
generally been light, from several hundredths to a quarter inch over
nrn SC in the past couple of hours. Given that the stratiform rain
shield will likely continue to diminish in the absence of
additional, concentrated deep convection, beyond the sporadic/
isolated cellular development like that which has recently developed
from near FAY to CTZ to GSB, the risk of flooding overnight appears
low.
.PREV DISCUSSION... /ISSUED 318 PM EDT Fri Jul 19 2024/
The cold front is now a stationary front as it has moved little
since this morning. The best estimate position of the front, mindful
of an outflow boundary sagging south from the boundary, stretches
from Davidson/Randolph east into southern Wake and into Wilson
County. An outflow boundary exists south of this tied to convection
from Wayne to Lee counties. The front arcs to the southwest to near
CLT and into northern SC/GA/AL.
Since the front has not made any southward progress the main showers
and storms have occurred along and south of the boundary, along US-
64. Storm chances are thus highest over the next few hours in this
area. With time, southward movement of the outflow from convection
should aid increased coverage of storms in the southern Piedmont,
Sandhills, and southern Coastal Plain by early evening.
While convection along and north of the boundary should weaken near
sunset with loss of heating, additional convection is forecast to
move into the southern and western Piedmont later tonight and
overnight into early Sat. This would be tied to mid-level energy
from MS/AL and upstream convection that may congeal over GA/SC and
track ENE. Isentropic ascent could also favor showers over the Triad
and western Piedmont overnight. Guidance also suggests perhaps an
MCV may track into the Triad early Sat, which could also touch off a
few isolated showers/storms along and north of the boundary in the
Triangle and northeast Piedmont early Sat morning. How much of this
convection survives with nocturnal stabilization is unclear, but
have 30-60 percent PoPs mainly US-1 westward.
Outside of convection, low stratus is forecast to envelope the area
overnight, especially along and north to northwest of the boundary.
Overnight lows are expected to be in the upper 60s to low 70s,
coolest across the north.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
As of 230 PM Friday...
The damp pattern will persist through the weekend, including above-
normal cloud cover and rain chances, and near to slightly below
normal highs. A marginal severe threat persists for Sat, and locally
heavy rainfall will remain possible throughout the weekend.
Sat/Sat night: Rain chances will be high amidst PWs of 2.0-2.3", but
the highest pops are likely to be skewed to earlier in the day than
usual, morning through mid afternoon, as indicated by the HREF local
probability matched mean output. Southwesterly mid level flow over
the region will draw MCVs from the current Gulf Coast convection
northeastward across the western and central Carolinas starting Sat
morning. It`s tough to tell exactly where the weak surface boundary
will be, but the latest RAP runs depict it sitting nearly W-E over
NC as the low-mid level perturbation lifts northeastward. Light low
level winds will limit mass convergence, but this may still play a
role in focusing locally heavy downpours and slow-moving storm
clusters. The RAP output also favors warm rain processes, with an
LCL-0C depth over 4 km, and slow MBE movement will increase the risk
of localized flooding. The risk of strong to severe storms is
supported by an uptick in mid level flow from 15-20 kts to 25-35 kts
Sat, within persistent moderate SBCAPE and beneath a modest upper
divergence max. After high morning-through-midday pops, we may have
a relative lull period for a portion of the afternoon until we see a
redevelopment of scattered convection late in the day and into the
evening, perhaps lasting into the early overnight with at least
marginal elevated CAPE lingering amidst growing CINH. Expect highs
to range from the 80s to lower 90s, with lows in the upper 60s to
mid 70s.
Sun/Sun night: Attempting to pin down convection details (both
location and timing) becomes more difficult by Sun, but we`ll still
be in a regime featuring weak Gulf-source southwesterly low-mid
level flow, between baggy troughing over the E Plains/Miss Valley
and a strong NW Atlantic ridge extending WSW toward FL. Both PWs and
the vertical thermal/moisture profile will likely exhibit little to
no change, although mid level flow will once again weaken, leading
to a reduced threat of strong storms. See no reason to change from
the good chance/likely pops, with continued variably to mostly
cloudy skies. We should see highs in the 80s to near 90 and lows
mostly in the low-mid 70s. -GIH
&&
.LONG TERM /MONDAY THROUGH FRIDAY...
As of 300 PM Friday...
...Above normal rain chances will lead to seasonable to slightly
below normal temperatures next week...
Sandwiched between persistent upper level troughing that stretches
south from the Great Lakes to the southern US Plains and a strong
subtropical ridge that extends over the western Atlantic and SE US,
deep SW flow will keep moisture-laden plume of 120-140% percent of
normal PWATs entrenched across the region all next week. DPVA via
shortwave impulses embedded in the SW flow, in tandem with daytime
heating and interaction with seabreeze/outflow will lead to
high/likely chances of showers and storms each day. The above normal
rain chances and associated increase cloud cover and will result in
seasonable to slightly below-normal high temperatures and mild above
normal min temps. Highs generally 85-90. Lows in the 70s.
The super ensemble mean average cumulative rainfall during the long
term period is between 1-2", with higher amounts possible within any
heavier convection.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
As of 820 PM Friday...
Generally VFR conditions are expected to start the TAF period. A
stationary front is draped along/south of the northern terminals
(RDU/RWI). As the front is progged to lift slowly northward or
remain stationary across central NC, the best chance of
showers/storms overnight would be at GSO/INT/RDU, where lift and
instability is more focused. Most high-res guidance suggests this,
but uncertainty in the coverage means that it cannot be ruled out at
FAY/RWI early Sat. Outside of storm chances overnight, CIGs are
expected to lower to LIFR, with conditions slowly rising to MVFR to
VFR midday Sat.
Outlook: Showers and storms will continue into this weekend and
early next week as a front stalls over the area and several impulses
track through in the moist flow. Early morning fog and stratus will
be possible each day as well.
&&
.CLIMATE...
Record High Minimum Temperatures:
July 19: KGSO: 75/2016 KFAY: 77/2023
July 20: KGSO: 75/2019 KRDU: 76/2020
July 21: KGSO: 76/2011 KRDU: 78/1932 KFAY: 80/2017
July 22: KRDU: 78/2011
July 23: KRDU: 78/2011
July 24: KRDU: 79/2011 KFAY: 79/1945
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SYNOPSIS...MWS
NEAR TERM...MWS/Kren
SHORT TERM...Hartfield
LONG TERM...CBL
AVIATION...Badgett/Kren
CLIMATE...RAH
Area Forecast Discussion
National Weather Service Topeka KS
628 PM CDT Fri Jul 19 2024
.KEY MESSAGES...
- Chances for off and on showers and thunderstorms are expected
this weekend through Tuesday.
- Cooler than average temperatures into early next week, then
warming through late week.
&&
.DISCUSSION...
Issued at 234 PM CDT Fri Jul 19 2024
As of 19Z, shortwave energy is noted in the SD/NE vicinity in
between the ridge still parked over the Four Corners and the upper
low circulating over the Hudson Bay. Thunderstorms associated with
that shortwave are moving through central NE, and additional
clusters of storms are expected to develop in western KS later this
evening. It is uncertain whether the storms currently in central and
eastern NE will maintain themselves as they approach the area. Only
the HRRR brings any of this activity into northern KS. If it does
make it by late afternoon or early evening, can`t entirely rule out
one of these storms producing gusty winds in north central KS where
the inverted-V profile looks more favorable and effective shear
approaches 35-40 kts. However, lapse rates and instability overall
are far better in western KS. That said, even if any of the storm
clusters from out there manage to make it this far east late tonight
and overnight, they would be moving into a less favorable
environment for severe weather. CAMs have been tracking the
strongest storms west of the area with our area more favored to see
general thunderstorms as MUCAPE remains under 1000 J/kg and lapse
rates are only around 6 deg C/km.
Hit or miss showers and thunderstorms are expected through much of
the weekend as the upper shortwave develops into a cut-off low and
stalls over the Missouri River valley region. Coverage looks
scattered throughout Saturday and Sunday and should not be a
washout, though most thunderstorms should occur late Saturday
afternoon into evening when there may be pockets of MUCAPE of 1000-
1200 J/kg. Shear weakens by this point and looks to remain weak
until the system eventually moves away. The probability for any
particular location to receive an inch of rain is low, but the HREF
75th percentile does show isolated locations with 1-1.5" by Sunday
morning. Based on that, it seems reasonable that any spot that sees
thunderstorms could get a quick inch or more of rain.
The upper low should start to weaken by Tuesday, keeping chances for
scattered showers and storms in the area through Monday and
gradually tapering off through Tuesday. The trough then moves east
Wednesday, bringing an end to the rain chances. Clouds and rain keep
cooler temperatures into early next week with highs in the mid 70s
to low 80s. A warming trend is expected Wednesday onward as mid-
level heights rise, bringing afternoon temperatures back toward 90
degrees.
&&
.AVIATION /00Z TAFS THROUGH 00Z SATURDAY/...
Issued at 610 PM CDT Fri Jul 19 2024
Expecting to maintain VFR conditions even when showers enter
the area with cloud decks above FL050. Kept VCSH for now due to
the off and on nature of the showers or embedded storms. First
of multiple waves passes around mid morning which should result
in a break in the precipitation.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
DISCUSSION...Picha
AVIATION...Drake