Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 11/02/24
Area Forecast Discussion
National Weather Service Cleveland OH
930 PM EDT Fri Nov 1 2024
.SYNOPSIS...
High pressure will build in tonight and remain overhead through
Sunday morning. High pressure exits east on Sunday, allowing a warm
front to lift north across the area Sunday night. The next cold
front approaches towards the middle of next week.
&&
.NEAR TERM /THROUGH SATURDAY NIGHT/...
Lake effect clouds will continue to gradually clear in NW Ohio
while remaining across much of Northeast Ohio and Northwest
Pennsylvania into Saturday. Temperatures have been slow to cool
so far but will fall quickly after clearing with high pressure
building in from the west with light winds. Only real change
overnight was to remove the mention of patchy fog as this seems
unlikely to be a concern with the drying airmass.
Previous discussion...A very quiet first half of the weekend is
in store as Canadian high pressure builds in. Stratus off the
lake will persist tonight and into a good portion of Saturday
across Northeast OH and Northwest PA. There have been some very
light radar returns across far Northeast OH and Northwest PA
this afternoon, with Ashtabula County Airport reporting a bit of
light rain at times. These very light lake effect rain showers
will be most prevalent through early this evening as a weak
trough axis drops southeast off the lake. Have some minimal
(20%) shower chances persisting tonight across parts of far
Northeast OH and Northwest PA, with high pressure expected to
build in enough by pre-dawn Saturday to end any lake effect rain
showers. Lake effect clouds will finally break completely later
Saturday afternoon or evening. Locations farther west should
see skies go mostly clear this evening and remain mostly
clear/sunny through the rest of the near term. Winds will go
light and variable tonight as high pressure builds in.
Certainly quite the airmass change from the record or near-record
warmth the last few days, with temperatures close to seasonal
averages through the near term. Lows tonight will range from the low
to mid 30s in Northwest OH where skies will clear to the upper 30s
and lower 40s where lake effect clouds persist. Highs on Saturday
will range from the low to mid 50s in Northeast OH and Northwest PA
to the upper 50s to near 60 in Northwest and Central OH. Lows
Saturday night will generally be in the 30s, with a few upper 20s
likely in colder pockets of far Northeast OH and Northwest PA.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
Going to get into a relatively familiar pattern in the short term.
High pressure drifts into New England and low pressure develops in
the central plains region. Flow aloft now southwesterly with an
upper level ridge to the southeast, and all of this sets up for
another period of warmth characterized by increasing southwesterly
winds in a tightening pressure gradient in the warm sector ahead of
a baroclinic zone. Upper 50s to mid 60s Sunday become mid 60s to mid
70s Monday as 850mb temperatures climb back into the teens. While
the cold front will be a long term forecast period event, waves in
the aforementioned southwest flow aloft bring the next chances for
rain to the CWA. Another scenario where thunder is being left out of
the forecast for now, but gusty shower potential returns. Might see
some fluctuations in the POPs with these upper level disturbances
moving through, and timing/coverage differences should be expected
in upcoming forecasts. Could see developing wind issues once again.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
Long term begins with eyes on the upper level flow continuing, which
is where the best chances for convection will exist prior to the cold
front arrival. Have POPs on the gradual increase as a result, and
first cold front will arrive late Tuesday night into early
Wednesday. Also likely to see a secondary cold front reinforcing the
colder airmass towards the end of the week which could generate some
precipitation coming off the lake in onshore flow. Like the short
term, wind issues prior to and after frontal passage could develop.
&&
.AVIATION /00Z Saturday THROUGH Wednesday/...
Broken to overcast skies are in place at all terminals at 00Z
with a clearing trend developing in southern lower Michigan
which will tend to work into NW Ohio terminals between 02-04Z.
Ceilings have ranged from 2800-3500 feet with most locations on
the VFR side. Clearing will be slower overnight from North
Central Ohio into Northwest Pennsylvania where northwest flow
will maintain a shallow lake effect cloud deck. RAP guidance
shows low level RH at 925mb increasing overnight which is
possible as high pressure expands and inversion heights lower
into Saturday. Due to this have clouds trending lower into the
MVFR range overnight into Saturday morning. Skies are expected
to scatter out in the 15-19Z window on Saturday.
Northwest winds will generally decrease overnight to 5 knots or
less. The exception is at ERI where flow may remain in the 5-10
knot range off Lake Erie. A land breeze is forecast to try to
develop at CLE so winds may back to southwesterly for a period
of time overnight. Otherwise, winds will tend to be northerly to
easterly on Saturday.
Outlook...Non-VFR possible with scattered rain showers Sunday
through Tuesday.
&&
.MARINE...
Northwesterly winds, easing through tonight and Saturday with wave
heights eventually falling below 2ft become east southeasterly 10-
15kts Sunday where open water wave heights return to 1-3ft while
protected nearshore zones will be under 2ft. Winds then become
offshore 15-30kts Monday and beyond, similar to events from this
past work week, ahead of an approaching and strengthening low
pressure system. Wave heights will increase rapidly away from shore
through Tuesday night with rough conditions expected in the open
waters.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...None.
PA...None.
MARINE...Small Craft Advisory until 11 PM EDT this evening for LEZ149.
&&
$$
SYNOPSIS...Sullivan
NEAR TERM...KEC/Sullivan
SHORT TERM...26
LONG TERM...26
AVIATION...KEC
MARINE...26
Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
807 PM EDT Fri Nov 1 2024
.SYNOPSIS...
Cool high pressure moves from the Great Lakes eastward going off the
New England coast by Monday. This high pressure keeps temperatures
across our region closer to normal for this time of year through
early next week. A warmer southerly flow of air develops around mid
week bringing well above normal temperatures back to our area.
&&
.NEAR TERM /THROUGH SATURDAY/...
Key Messages...
2) Light Rain Showers Will Redevelop Overnight into Saturday
Morning, Mainly over the western Piedmont
3) Patchy to Locally Dense Fog Returns to the Mountain Valleys
Overnight into Daybreak Saturday
As of 751 PM EDT Friday: A weak cold front just east of the mtns
will continue to move slowly eastward across the forecast area
overnight. Satellite imagery continues to show extensive cloudiness
along the boundary, so sky cover was bumped up again. Radar
looks fairly quiet, so it would appear the shower activity has
diminished as expected. The last few runs of the HRRR continue to
show redevelopment along the front early Saturday, mainly over
the western Piedmont zones, so we re-introduce a slight chance
before daybreak. Amounts will be minimal. As for the mtns, the
usual valley fog might be hindered by the lingering cloud cover.
Otherwise, the cold front should slip south of the forecast area
early on Saturday, but clouds will linger across the region. It
might take until well into the afternoon before we see much
sun. Highs on Saturday will be slightly cooler behind the front,
thanks to flow turning northeasterly, but will still end up about
4-8 degrees above climo.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
As of midday Fri: Fairly strong, high pressure will drift across the
northeastern CONUS Saturday night and Sunday. Cold front will ooze
south of the area; based on reduced thicknesses alone this should
result in temps being a few degrees cooler on Sunday compared to the
previous day. Although the synoptic setup is reminiscent of CAD over
the weekend, this high is a few mb too weak to support classical CAD.
Furthermore, 925-850mb winds should veer to northerly over portions of
NC/SC in the wake of the front, but continue to appear light (15 kt or
less). This will limit the degree of airmass change. Low-level ridge
is shown to remain centered near the Southeast coast, and some model
solutions maintain southerly flow over the front within the CWA
Saturday night, particularly the western areas. With time southerly
flow is increasingly likely to occur within that layer, and moistening
generally occurs as a result. This warrants some cloud cover lingering
Saturday night, diminishing diurnally Sunday, and then redeveloping
Sunday night and lasting most of Monday. The deterministic models
develop very little to no QPF until Sunday night or Monday, but even
then their response is small and limited to the southeasterly upslope
areas (below the Blue Ridge Escarpment) and the Savannah River Valley.
If precip does develop, it could promote hybrid CAD, although by then
the parent high will have drifted into a somewhat less favorable
position. More persistent cloud cover should lead to Monday`s max
temps trending still cooler, finally returning to around normal in
many spots. The currently small chance of CAD further
supports such a trend as cooler solutions are incorporated into model
blends; if CAD does transpire temps likely would end up at least a
little below normal for the majority of the CWA.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
As of 200 PM Fri: Influence of high pressure to our northeast will
diminish at least slightly Monday night as it weakens and moves further
offshore; flow in the 925-850mb layer atop it will veer, becoming more
southerly than SE`ly Tuesday. Precip chances increase a bit with
somewhat better model response developing, with upglide persisting and
moisture flux possibly being enhanced as next cold front moves into
the MS Valley. The airmass will modify and thicknesses increase a
little, so temps are most likely going to be at least slightly warmer,
although any warming trend will be muted by abundant cloud cover that
day, if not the effect of weak/shallow in-situ CAD developing with
precip. The moist southerly flow regime will continue until the front
reaches the area, which currently does not look likely to occur until
after the end of the period Thursday night, so periodic cloud cover
and small PoPs remain in the forecast through then. Temps warm back to
around 10 degrees above normal Wed and still warmer Thursday. It is
worth pointing out that NHC has an area of interest in the southern
Caribbean which has a high probability of developing into a tropical
cyclone in the southern Gulf of Mexico late next week. The Canadian
GDPS is a fast outlier in bringing this system north and allowing its
moisture to be pulled into the frontal zone Thursday, resulting in
considerably higher QPF over the CWA at that time. Other models
(GFS/EC and their ensembles) do not develop this interaction and keep
QPF low-impact thru the end of the period.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
At KCLT and elsewhere: VFR at all terminals through the late evening
as a cold front moves slowly across the region. The boundary
should keep moisture pooled across the region, particularly on
the poleward side, with satellite imagery showing a wide band of
ceiling restrictions. The guidance seems to hit this fairly hard
with MVFR or worse ceiling restrictions developing around daybreak
Saturday at all terminals. The LAMP is quite pessimistic with the
possibility of brief IFR/LIFR at most terminals. We will lean in
that direction, but conservatively for now. Seems likely that a low
cloud ceiling will redevelop with some daytime heating Saturday,
most likely MVFR into the early afternoon. The wind should be
mostly NE behind the boundary into Saturday afternoon.
Outlook: MVFR restrictions may linger through Saturday evening,
especially at KAVL. Drier weather and VFR conditions are expected
Sunday into Monday as dry high pressure builds back over the
terminals. Another weak cold front approaches out of the west
Tuesday into Thursday bringing light rain chances, and possibly
restrictions, back to the terminals. Mountain valley fog and low
stratus may develop each morning.
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...None.
NC...None.
SC...None.
&&
$$
SYNOPSIS...DEO
NEAR TERM...AR/PM
SHORT TERM...Wimberley
LONG TERM...Wimberley
AVIATION...PM
Area Forecast Discussion...UPDATED
National Weather Service Jackson MS
900 PM CDT Fri Nov 1 2024
...New MESOSCALE UPDATE...
.MESOSCALE UPDATE...
Issued at 900 PM CDT Fri Nov 1 2024
No noteworthy changes are planned for the near term forecast at
this time. The area is currently split between a region of low
stratus over northern portions of the area and higher clouds and
scattered showers over the southern half. Occasional breaks in
these clouds have resulted in brief fog development already in the
Meridian area early this evening. Showers have been decreasing in
coverage and are expected to continue to do so overnight,
remaining limited to mainly southwest MS and northeast LA. With a
seasonably humid airmass and wet grounds, any breaks in the clouds
overnight will encourage additional fog development. And if this
is sustained, fog could be locally dense. It remains somewhat
difficult at this stage to pin down where that is most likely to
occur. The HRRR which was previously showing little fog has
trended toward more development in recent runs, especially in the
area where the HREF has showed greatest potential, across eastern
and central MS. For now, we will continue with a more generic
limited fog threat graphic and adjust or consider an advisory if
needed as things evolve overnight. /DL/
&&
.DISCUSSION...
Issued at 317 PM CDT Fri Nov 1 2024
Tonight into Saturday:
As the upper-level trough continues to pull northeast away from our
region, we`re left with the southeastern CONUS ridge overhead today.
A portion of the upper-level energy was trapped beneath the ridge -
or at least some convectively driven vorticity - as remains evident
on satellite imagery over southeast LA today. Reinforcing cold air
north of the front has been slowing the mixing out of low clouds
today, but clearing overnight is expected with the loss of daytime
heating and drier air easing in. When the rain shower activity winds
down overnight and skies begin to clear in patches, temps should
cool below today`s dewpoint values and initiate fog development.
Guidance is a bit varied in where the best potential is for dense
fog, so have broadly included "patchy fog" wording in the weather
for the whole area tonight and included a Limited threat for the
local hazard graphics. Tomorrow, the arrival of some warmer and
drier air should mix out clouds better than today and give us highs
more in the lower 80s range. /NF/
Saturday night through next week...
The pattern across the CONUS will remain active with an amplified,
progressive upper pattern. High pressure will generally be in
control through Monday as a stalled front dissipates across the area
this weekend with fair, warm conditions expected. Highs likely in
the mid 80s for most through the weekend with above normal humidity
keeping overnight lows elevated, in the 60s F.
Our next chance at rain comes Tuesday into Wednesday when an upper
trough digs into the Southern Plains before ejecting into the
Mississippi Valley. Associated surface cold front will likely bring
a band of showers and potentially thunderstorms, a few of which
could be stronger with some gusty winds, through the area during the
day Tuesday. This front will likely have some similarities to the
front currently stalled across the area, resulting in a modest
decrease in temperatures into midweek with highs in the middle 70s F
north to mid/lower 80s F south. Temperatures in a similar range will
continue through the week as the front will likely fail to bring a
substantial cooldown and itself stalls despite its best efforts as
the upper ridge remains stout.
The lingering front and the period of somewhat lower heights with
boundary layer moisture not scoured out will likely allow for clouds
and some rain chances through the end of the week. This pattern of
light winds, boundary layer moisture, wet ground, and
stalled/decaying frontal boundary will also allow for patchy and
possibly dense fog to develop each night. The degree of fog
potential and areas most favorable will be assessed each day but it
is possible that hazardous weather outlook graphics or Dense Fog
Advisories could be needed at times this upcoming week.
Regarding the tropics...
We are down to the last month, now, of Hurricane Season and we do
have an area of interest that the National Hurricane Center in
Miami, FL has designated as having a high chance (70%) of
development into next week. Model guidance as would be expected at
this stage has a large spread of outcomes as the system in the
western Caribbean lifts north. It does seem likely now that the
disturbance will attempt to organize and could end up in the Gulf of
Mexico by later next week. While it`s too early to be confident,
recent seasonal cooling of Gulf water and expected frontal activity
near our area make the potential for a higher end hurricane impact
local to the ArkLaMiss low at this time. That said, the system has
some potential to bring local impacts of some kind in the D7-10 time
frame and we will be watching closely with numerous updates on the
progress of the disturbance in coming days. /86/
&&
.AVIATION...
(00Z TAFS)
Issued at 624 PM CDT Fri Nov 1 2024
An MVFR stratus deck encompasses areas mainly north of a HEZ to
JAN to GTR line early this evening with scattered mainly light
SHRA persisting across parts of south MS and central LA. SHRA will
begin to decrease overnight, though a few areas of -RA will
remain possible. However, fog development is expected tonight
through Saturday morning resulting in MVFR visibilities, though
localized LIFR to IFR is possible. Improvement is expected by mid
to late morning, with VFR conditions expected through the
remainder of the TAF period. /DL/
&&
.PRELIMINARY POINT TEMPS/POPS...
Jackson 64 83 63 83 / 30 10 0 10
Meridian 63 82 61 83 / 10 0 0 0
Vicksburg 65 82 61 84 / 30 10 0 10
Hattiesburg 64 86 62 85 / 10 0 0 10
Natchez 66 82 63 83 / 30 10 0 10
Greenville 63 80 62 83 / 10 20 0 0
Greenwood 63 82 63 84 / 10 10 0 0
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...None.
LA...None.
AR...None.
&&
$$
DL/NF/86