Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 09/04/23
AREA FORECAST DISCUSSION
National Weather Service Bismarck ND
1008 PM CDT Sun Sep 3 2023
.UPDATE...
Issued at 1007 PM CDT Sun Sep 3 2023
A line of thunderstorms continues to approach the North Dakota
border from Northeastern Montana. The storms will reach the
northwest in a few hours. Another line of storms is approaching
the southwest, but still remains a few hours out. Storms should
weaken as instability decreases, however storms will likely
continue overnight. CAMs have the southern line weakening and
diminishing by the state line. Some smoke continues to linger in
the north central, although visibilities continue to improve. No
updates were made to the current forecast as the forecast remains
on track.
UPDATE Issued at 626 PM CDT Sun Sep 3 2023
A cumulus field continues to build across eastern Montana ahead
of an upper level wave that is forecast to move through the region
tonight. Clouds will continue to increase as the wave approaches.
CAMs have storms moving in from Montana around 08Z tonight mostly
confined to the northern half of the state. Showers and
thunderstorms are possible tonight as the wave moves through,
severe weather is not anticipated tonight. Smoke will continue to
disperse this evening improving conditions across the state. No
updates are needed at this time as the forecast will remain on
track.
&&
.SHORT TERM...(This Evening through Monday)
Issued at 209 PM CDT Sun Sep 3 2023
Current surface analysis places trough through the upper midwest
into the central plains, while another low lingers to the lee of
the Northern Rockies. High remains over southeast Saskatchewan/southern
Manitoba into North Dakota. Upper level analysis places low
amplitude ridge passing over our area and to the east, while
low/trough now sliding over the Cascade Mountains/northern Sierra.
Southwest flow is starting to nudge towards far western portions
of our area with the gradual departure of the aforementioned
ridge. Over our area, main concern at this time is wildfire smoke
that is reluctant to depart when compared to latest HRRR forecast.
For tonight, upper ridge continues its departure with active
southwest flow developing over our area. Rain shower chances with
some thunderstorms will spread into the area as the lee side
surface trough pushes east and sets up over our area late tonight.
Severe threat remains low given meager instability and low deep
layer shear. With respect to smoke, will keep areas of smoke in
through the evening until the showers/storms start to move in. May
need to re-evaluate this a little later.
On Monday, shower chances with a few storms linger mainly over
northern areas through the morning as a cold front starts its
progression into the area. Concerns come more later in the day
mainly over southwestern into south central North Dakota where
models have been quite consistent with increasing instability
(1000-2000 J/Kg) over this area about the time the front slowly
moves through. In addition, deep layer shear will be quite
elevated, right around 40 to 50 kts at this time. Thus, the severe
threat continues mainly over this area where we are advertising
the possibility of ping pong ball size hail and 60 mph wind gusts
for later afternoon Monday into Monday evening. Now, as we go
through later Monday evening through Monday night into Tuesday,
the hail/wind threat will be on the decrease, but
shower/thunderstorm coverage will be on the increase which may
lead to some heavier rainfall, especially over the southwest and
south central where NBM probabilities for an inch or greater have
bumped up a little bit, now more in the 40 to 60 percent range for
most locations.
.LONG TERM...(Tuesday through Sunday)
Issued at 209 PM CDT Sun Sep 3 2023
System gradually departs from northwest to southeast
through the day into the evening Tuesday, with rather chilly
temperatures in the wake of the front. Highs only expected in the
60s over most locations.
Mainly quiet weather then expected through the remainder of the
week with only some low precipitation chances from time to time.
Temperatures climb back to near or a bit below average for the end
of the work week.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday Evening)
Issued at 626 PM CDT Sun Sep 3 2023
VFR conditions will continue across much of the region tonight.
Thunderstorms are expected to move into the western half of the
state tonight (08z) and the northern half early tomorrow
morning (12Z). Winds will switch out of the north as a front
approaches early tomorrow morning. MVFR conditions are possible
under thunderstorms as moderate showers could reduce visibilities
Smoke will continue to clear across the state this evening.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
UPDATE...Johnson
SHORT TERM...JJS
LONG TERM...JJS
AVIATION...Johnson
Area Forecast Discussion
National Weather Service Columbia SC
727 PM EDT Sun Sep 3 2023
.SYNOPSIS...
High pressure dominating the region will remain in place through
at least the middle of the week. Temperatures will be near
normal with afternoon highs in the low 90s though humidity will
remain low. The next chance of rain comes late this week as a
cold front approaches from the north. Temperatures will also
cool as the upper ridge is replaced by a trough.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
Clear skies and light winds remain over the region as high
pressure and upper level ridging dominate the eastern US.
Radiational cooling relatively strong overnight although there
may be a little mixing especially north of CAE as a weak trough
moves across northeast SC overnight. Rap and Nam indicate a
15-20 kt low level jet, GFS has weaker boundary layer winds.
Low temperature forecast a little below the Mos consensus. So,
lows in the low to mid 60s. A few patches of fog are possible
during the early morning and sunrise hours mainly in fog prone
locations and near area rivers.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY/...
High pressure aloft builds over the Southeast U.S. through the
middle of this week. Rising H5 heights will lead to above normal
temperatures with highs in the mid to upper 90s. Low level moisture
will be slow to increase with dew points climbing into the lower to
mid 60s, therefore humidity levels will remain lower than normal for
early September.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
The ridge axis breaks down over the Southeast U.S. late this week
and into the weekend as an upper level trough dives down into the
Great Lakes and Northeast U.S. This trough will push a cold front
into the region. This front should bring a slight chance or chance
of showers and thunderstorms Friday through Sunday. Temperatures
will cool off by next weekend with highs in the mid to upper
80s.
&&
.AVIATION /00Z SUNDAY THROUGH FRIDAY/...
VFR conditions expected to dominate the period with early
morning fog and stratus possible at AGS.
High pressure is expected to remain in control of the region
through the TAF period with clear skies and light and variable
winds. Winds become mainly south to southwesterly around 5 kts
after about 18z. The only concern is the potential for fog and
stratus during the early morning and sunrise hours. Have kept
the mention of MVFR fog at AGS from 04/08z to 12z and will
continue to monitor. Elsewhere, confidence remains too low to
include in the TAFs. If fog which does develop, it will likely
mix out rapidly with sunrise leaving the remainder of the
period VFR.
EXTENDED AVIATION OUTLOOK...No significant impacts to aviation
expected through Friday.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
GA...None.
SC...None.
&&
$$
Area Forecast Discussion
National Weather Service Cleveland OH
916 PM EDT Sun Sep 3 2023
.SYNOPSIS...
Broad high pressure over the Tennessee Valley and Appalachians will
expand north into the eastern Great Lakes through Labor Day.
This high will remain in control through mid week before a cold
front approaches Wednesday. This front will cross the region
by Thursday followed by a trough lingering into Friday.
&&
.NEAR TERM /THROUGH MONDAY NIGHT/...
900 pm update...
There were no adjustments needed to the ongoing near term
forecast with this update.
Previous discussion...
Unseasonably strong mid/upper ridging centered over the Mississippi
and Tennessee Valleys will continue to build tonight and Monday
as a deep mid/upper trough over the western CONUS this
afternoon gradually deamplifies and swings toward the northern
Plains Monday. This ejecting trough will push the mid/upper
ridge axis farther east over the Appalachians and NE CONUS by
late Monday and Monday night as the associated surface high
elongates from the eastern Great Lakes through the Appalachians
and Mid Atlantic. This will allow for continued warm air
advection and associated southwesterly low- level flow through
Monday night leading to a hot and humid Labor Day. This is in
stark contrast to the below normal temperatures that dominated
Summer 2023. Mid-level clouds from the central Great Lakes
spilling over the NE periphery of the mid/upper ridge will
continue to impact NE Ohio and NW PA at times this evening and
tonight. This combined with a lot of stratocumulus streaming
northeastward from Illinois and Indiana into Ohio this afternoon
due to the moisture advection has kept temperatures in the low
to mid 80s in most areas. NW Ohio is the only place that has
reached the upper 80s. The stratocumulus will dissipate by
sunset, although the occasional mid-level clouds will continue
in NE areas through tonight. The abundant low-level moisture and
continued warm air advection will lead to a very warm and muggy
night with lows only falling into the upper 60s/low 70s.
As the mid/upper ridge axis shifts east Monday, the mid-level cloud
deck will be shunted out of the area. This will lead to mostly sunny
skies other than a redevelopment of some afternoon cumulus. This
will allow highs to warm into the upper 80s to near 90 areawide.
Interestingly, 850 mb temps actually decrease Monday. Values peak at
around 22 C early tonight and fall to 17-19 C Monday as the tongue
of warmest 850 mb air emanating from the southern Rockies gets
deflected across the central Great Lakes instead. The latest NAM and
RAP are in agreement with this scenario, and it makes sense because
it follows the EML plume. With this being said, lowered high
temperatures 1 to 2 degrees for Monday. Did not go as cool as the
latest NBM, but it`s possible that highs stay in the upper 80s
except for NW Ohio where 90 is more likely. Nevertheless, dew points
staying in the upper 60s to low 70s will support afternoon heat
indices in the mid to upper 90s in NW and north central Ohio, so it
will be plenty hot and humid to get a final pool day in. Lows Monday
night will stay very warm and muggy again, only falling into the
upper 60s/low 70s.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
High pressure to the south of the region will remain in control for
most of the region Tuesday. However we will continue to see a hot
and humid airmass continues to advect into the region ahead of cold
front that moves into the central Great Lakes by Tuesday evening.
This may allow for low chances of thunderstorms across NW OH late
Tuesday afternoon into the evening. The better chances of showers
and thunderstorms arrives Wednesday afternoon into the evening as a
cold front moves west to east across the region.
Temperatures remain well above seasonal averages Tuesday and
Wednesday. High humidity levels will keep heat index values in the
90`s. A few locations across NW OH may attempt to touch 100 degrees
but at this time we believe the region remains just below the heat
advisory criteria.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
An upper level trough will take its time moving across the region
Thursday through Saturday. Best lift should move across the region
Thursday night into Friday. This lift will be enhanced with
afternoon heating Thursday and Friday afternoon`s. The cooler air
aloft should allow for thunder during the afternoon`s with
predominantly showers Thursday night and Friday night. By Saturday
any remaining showers would be located over NE OH into NW PA. High
pressure should take back control of the weather Saturday night into
Sunday with dry conditions returning.
Thursday looks to be the warmest day of the long term period with
highs withing a couple degrees of 80 (normal for this time of year).
Cooler Friday through Sunday with 70`s common. Lows mostly in the
50`s.
&&
.AVIATION /00Z Monday THROUGH Friday/...
VFR conditions will continue through this next period of TAFs
with no aviation weather concerns. Skies will be mostly clear to
fair weather skies through Monday afternoon and evening. Winds
will be from the southwest 5 to 11 knots with some midday and
afternoon gusts up t0 20 knots possible.
Outlook...VFR expected through early Wednesday. Non-VFR is
possible with scattered showers and isolated thunderstorms
Wednesday afternoon through Thursday.
&&
.MARINE...
A bit more of a westerly wind of 15 to 20 knots has been enough to
generate waves around 4 feet from Geneva On The Lake to Ripley this
afternoon. Seeing whitecaps on a lake cam near Ashtabula and several
buoy and CMAN stations around 20 knots made us hoist a short lived
small craft advisory. The winds should decrease quickly this
evening. Unfortunately it looks like a similar setup for Monday
afternoon and evening with a more westerly flow anticipated from
Geneva On The Lake to Ripley. So we could end up needing a short
time period small craft advisory and beach hazard statement. Later
shifts can dig into this and decide.
Southwesterly winds on Tuesday look to be a little bit lower as we
wait for low pressure to move across southern Ontario Wednesday
night into Thursday. Ahead of a cold front on Wednesday
southwesterly winds increase to 15 to 20 knots, especially across
the western basin. A cold front should cross the lake Thursday with
winds shifting to the west and northwest late in the day.
&&
.CLIMATE...
Temperatures during the first half of the week will be above normal
for early September. Temperatures are currently forecast to
approach record high values at a few sites.
Daily Record High Maximum Temperatures
Date Toledo Mansfield Cleveland Akron Youngstown Erie
09-04 95(1960) 92(1973) 95(1953) 96(2018) 94(1953) 97(1953)
09-05 95(1954) 95(1954) 99(1954) 98(1954) 99(1954) 93(2018)
09-06 95(1990) 94(1954) 98(1954) 96(1954) 93(1954) 93(2007)
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...None.
PA...None.
MARINE...None.
&&
$$
SYNOPSIS...Garuckas
NEAR TERM...Garuckas/Griffin
SHORT TERM...MM
LONG TERM...MM
AVIATION...Griffin
MARINE...MM
CLIMATE...
Area Forecast Discussion
National Weather Service Las Vegas NV
110 PM PDT Sun Sep 3 2023
.SYNOPSIS...Scattered thunderstorms remain possible through this
evening, mainly in Lincoln and northern Clark Counties. Otherwise,
drier air will move in for Labor Day with cooler than normal
temperatures to start the week...trending near average by next
weekend.
&&
.DISCUSSION...through next weekend.
Potent early-season shortwave trough will zip through the Great
Basin this evening, spreading drier air in from the west. This
will stunt thunderstorm chances across much of the area today and
this evening, though lingering moisture and instability combined
with 40-50 knots of deep layer southwesterly wind shear will
support the potential for a few stronger storms across Lincoln,
northern Clark, and northern Mohave Counties through this evening.
The Storm Prediction Center did coordinate a Severe Thunderstorm
Watch earlier this afternoon which includes Nye and Lincoln
Counties, though the threat for Nye county is mainly in the
hammerhead of the county across central Nevada. The HRRR continues
to suggest the potential for a supercell or two forming in Lincoln
or northeastern Clark Counties during the afternoon and early
evening which could produce severe wind and hail.
Once drier air overspreads the entire region later this evening,
the forecast for the rest of the forecast period is dry. A weak
cold front (the first of the meteorological fall season) does
drift through overnight with cooler than average Labor Day
conditions expected. Thereafter, a slow warming trend commences
with closer to typical temperatures of early/mid September
arriving by late week and into next weekend as a low amplitude
ridge builds across the Southwest.
&&
.AVIATION...For Harry Reid...Gusty southwest winds this afternoon
and evening, with gusts of 20-25 knots expected. Isolated storms are
also possible this afternoon, but impacts to the terminal are more
uncertain. Hi-res guidance doesn`t show much signal for outflows in
the valley, in part due to the gusty winds and the general
consensus that any convection in the valley will remain on the
north side or the high terrain there. Storm chances at the airport
remain less than 20% and fall below 5% by 00z. Gusty west-
southwest winds continue through the evening before weakening
tonight. A weak cold front moves in tomorrow morning, bringing a
northerly wind shift.
For the rest of southern Nevada, northwest Arizona and southeast
California...Gusty southwest winds across the region this afternoon,
with gusts between 20 and 30 knots. Gusty conditions continue
through the evening before gradually weakening overnight. Drier
conditions today, with only the Las Vegas Valley sites having a
noteworthy chance of convection (around 20% probability). Storm
chances end around 00z and skies begin to clear. A weak cold front
dropping south through the area will bring north winds to KBIH this
evening, and the remaining sites tomorrow morning.
&&
.SPOTTER INFORMATION STATEMENT...Severe Thunderstorms are possible
through this evening in Lincoln, northern Clark, and northern
Mohave Counties. Spotters are encouraged to report any
significant weather or impacts according to standard operating
procedures.
&&
$$
DISCUSSION...Outler
AVIATION...Woods
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