Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 11/01/22
Area Forecast Discussion
National Weather Service Charleston SC
1037 PM EDT Mon Oct 31 2022
.SYNOPSIS...
A weak disturbance will bring unsettled weather to our area
through tonight. High pressure will then prevail across the
region the rest of this week.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
A few showers have finally developed in association with a pre-
frontal trough near and west of US-301, while showers offshore
have decreased in areal coverage from earlier. With continued
poor MLCAPE, lapse rates and instability, we don`t foresee too
much potential for anything more than isolated to maybe
scattered showers into the overnight period.
Guidance continues to indicate the potential for fog, some of
which will be dense. the highest probabilities from the NARRE-
TL, LAMP, NBM and SREF look to be over our South Carolina
counties into the coastal corridor of Georgia late at night.
Other guidance such as the RAP, HRRR and NAM also have some
potential across interior Georgia. Since there is this
discrepancy we hold onto the mention in all counties for the
Hazardous Weather Outlook. The overnight forecasters can fine
tune this as necessary.
It`ll be an exceptionally warm night with elevated dew points
and a southwest synoptic flow. Not quite at record levels, but a
solid 10-12F above climo, or at min values more typical late
September/early October, or mid May.
Previous discussion...
The main moisture convergence and the higher MLCAPE of around
1500 J/kg will stay offshore and out near the Gulf Stream. This
is where the better chances of showers will occur early on.
There is less moisture convergence and lower MLCAPE near 1000
J/kg situated near and west of the local counties. Eventually
some showers will form in proximity to those conditions, but
based on recent temp trends we have decreased PoP early on.
While we can`t entirely rule out a clap of thunder, since the
HREF 1 hour t-storm probabilities are less than 10% and CINH
will continue to increase, we have removed mention of t-storms
from the forecast.
With drier air aloft and considerable boundary layer moisture,
plus winds going light or calm, there is the potentially for
fog late tonight into Tuesday morning. Favorable condensation
pressure deficits and FSI values, moderate probabilities from
the SREF and HREF, and utilizing the LAMP guidance which did
outstanding last night with the dense fog, we have added mention
of a possible Dense Fog Advisory to the Hazardous Weather
Outlook. The main negative factor might be the showers that
could prevent it from occurring. We will continue to monitor
through the night.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/...
Tuesday: To begin the day, a weak cold front will be situated along
the coast. Throughout the morning, high pressure will build into the
region and push the cold front offshore and further away. By
afternoon, drier air moving in will keep the day rain-free. With
rising heights and thicknesses, high temperatures will be warm for
this time of year. Highs are forecast in the upper 70s to mid 80s.
Overnight, shortwave energy will approach from the west but with
subsidence in place, have maintained a dry forecast. Although, there
could be a few sprinkles, especially across the waters. Low
temperatures will be in the mid 50s to mid 60s.
Wednesday: Mid-level low pressure to the north will slowly drift
eastward throughout the day. Then overnight, it is expected to shift
southward. While the impacts should be limited by this feature, an
uptick in moisture is possible. At this time, with high pressure
lingering at the surface, any chance of shower development will be
quite limited due to extensive dry air. As for cloud cover, the day
will start with partly to mostly cloud skies then slowly clear out
by the overnight. High temperatures will be a few degrees cooler
than previous days. The forecast calls for mid 70s to low 80s. Low
temperatures will be in the 50s.
Thursday: The aforementioned mid-level low will continue to shift
offshore into the Atlantic as a mid-level ridge builds in the Gulf
of Mexico. At the surface, high pressure will prevail. Therefore,
another rain-free day is expected with limited cloud cover. The only
exception will be over the waters where there could be a few
sprinkles, especially in the overnight. High temperatures will be in
the mid to upper 70s.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
Mid-level ridging will shift into the region on Friday and then
drift northeast through the weekend. To the west, a mid-level low
will shift east while a cold front races across the U.S. While most
of the area is forecast to remain rain-free through the majority of
the period, there could be showers across the coastal waters and
just along the coast. Although, the forecast could change based on
the timing of the cold front. High temperatures will be in the mid
70s to mid 80s with lows in the mid 50s to mid 60s.
&&
.AVIATION /03Z TUESDAY THROUGH SATURDAY/...
All of the terminals will stay VFR through late tonight, before
stratus and fog develops within a very moist boundary layer
featuring a 2 to 3C inversion off the surface. Timing is a bit
uncertain since a cold front will be approaching, but leaning
toward climatology and the model consensus, we have MVFR
conditions developing at 08Z, with a period of IFR or even LIFR
to occur from 09-13Z. Our 00Z TAFs have conditions down to 2SM
in BR and OVC005, but even lower visibilities and/or ceilings
are likely. That potential will be addressed in the next TAF
set. The inversion lifts quickly by mid to late morning,
allowing for VFR to return.
Meanwhile, since the risk for showers in association with a cold
front and pre-frontal trough is so low tonight, this does not
require a mention with the latest TAF set.
Extended Aviation Outlook: Prevailing VFR.
&&
.MARINE...
Tonight: Winds are forecast to veer from the SE to S early on to
the SW by late tonight as a cold front approaches from the
west. Winds speeds are expected to remain around 10 kts or less.
Seas are forecast to range from 2 to 4 ft.
Areas to patchy fog and low clouds are expected to develop over
land late tonight, and if the winds can turn more toward the W
close to daybreak or thereafter, the fog would drift over the
Charleston Harbor and along the immediate coastal waters of GA
and SC late into Tuesday morning. We will closely monitor for a
possible marine Dense Fog Advisory
Tuesday through Saturday: Overall, high pressure will prevail at the
surface while a mid-level low to the northwest shifts east then
drops south and offshore by late week. West winds on Tuesday at 5 to
10 knots with seas less than 3 feet are expected. Thereafter, the
pressure gradient will tighten and Small Craft Advisories will be
possible come Wednesday for winds and seas and persist through at
least early weekend.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...None.
SC...None.
MARINE...None.
&&
$$
NEAR TERM...
SHORT TERM...RAD
LONG TERM...RAD
AVIATION...
MARINE...
AREA FORECAST DISCUSSION
National Weather Service Eureka CA
251 PM PDT Mon Oct 31 2022
.SYNOPSIS...A potent cold front will approach the North Coast
late tonight, and then move across the area Tuesday bringing rain
to the valleys, snow to the high mountains and gusty westerly
winds. Much colder temperatures, mountain snow showers and valley
rain showers are expected in the colder air behind the front
Tuesday night through Wednesday. High pressure will start to build
Wednesday night through Thursday, bring drier weather to Northwest
California. Freezing temperatures and frost in the valleys are
probable each morning Wednesday through Friday. A series of fronts
will bring more rain and mountain snow this upcoming weekend.
&&
.DISCUSSION...Satellite imagery showed a frontal boundary stretching
southwestward from central Oregon to about 40N west of 135W as of
2 PM. A wave has been slowing the eastward progression of the
front. The bulk of the rain will most likely not reach land areas
til late tonight due to this slower eastward progression. Most of
the forecast area will remain dry this evening. There are a couple
of caveats. Rain chances will increase above 50% after 8 PM for
the Del Norte county coast, though the heavier rain rates will
probably hold off til after 11 PM. Also, a few light showers or
sprinkles may also occur around the Humboldt Bay after about 8 PM
(20% chance). By far, the bulk of the rain will occur after 11 PM
or more likely toward early morning Tuesday for much of the North
Coast. The front will move south and east across the remainder of
the area Tuesday morning, providing much needed rainfall to the
entire the forecast area. Rain amounts will probably taper off for
the far southern portion of the forecast, through southern Lake
county could get 0.25 of an inch of storm total rain. The moisture
with this front is not very high, PWATS less than 1 inch. The
front has strong dynamics and thermal advection which will aid in
the upward vertical motion and higher rain rates intersecting with
the coastal terrain early Tuesday. About 1 inch of storm total
rainfall will be possible for Del Norte, portions of Humboldt and
portions of northwest Mendocino counties by afternoon Tuesday. It
will be a quick shot of rain. Models indicate the rain quickly
winding down for the North Coast by mid morning Tuesday right
behind the front. Gusty westerly and northwesterly winds will
probably develop after frontal passage. The strongest gusts to 30
or 40 mph will be confined to higher elevations/ridges and most
likely localized.
The coldest air so far this fall (-2C at 850mb) will follow in
the wake of the front on Tuesday. Most of the precipitation will
probably occur in the colder air behind the front Tuesday morning.
Snow levels will rapidly fall to 4500-5000 feet Tuesday morning.
HRRR and multi-model guidance indicates 12 hour accumulations of
2 to 3 inches for Scott Mountain Pass. Thus, a winter weather
advisory has been hoisted for northern Trinity county,
particularly for Scott Mountain Pass on highway 3. The ground may
still be too warm for the snow to stick on the road. Snow levels
will continue to lower Tuesday night through Wednesday, however
snow amounts may not be sufficient to warrant additional
advisories, generally under an inch. The high mountain peaks in
Del Norte and northern Trinity counties above 5000 feet will
probably have 6 inches or more through Wednesday afternoon.
The potential for thunderstorms will also begin to increase
Tuesday afternoon and evening for mostly the northern coastal
waters and the North Coast as 500mb temperatures fall to -30c
or less and lapse rates steepen. CAPE as usual with these maritime
cold air outbreaks from the Gulf of AK will be low, under about
200j/kg. The trough aloft does look to acquire a slight negative
tilt which may help to promote upward motion and offset the
downward vertical motion associated with deep layer cold air
advection. A secondary perturbation in the NW flow aloft will
follow early Wednesday and may increase the potential for low top
thunderstorms. The potential for small hail is still not looking
very great at this point. The depth of the near surface warm layer
should decrease Tuesday night and early Wednesday morning which
should allow some hail particles to reach the surface before
melting. The ground may be still be too warm for any accumulations.
High pressure will begin to build into the area Wednesday night
into Thursday. Drier weather and much colder temperature are
expected. Coastal area may still have some showers, mostly over
the waters into Thursday morning. Guidance at the moment indicates
easterly winds which will likely keep the shallow convection
offshore. We are probably going to have freezing and subfreezing
temperatures for many interior valleys Wed-Fri. Coastal areas may
also have frost and freezing temperatures, however confidence is
not as high with the potential for some cloud cover.
Deterministic models and ensemble means indicate another trough
sagging from the NW toward the latter portion of the week into
early next week. The timing and depth of this trough is uncertain.
Deterministic GFS and deterministic ECMWF has the first front
moving across the area on Saturday followed by another one
Sunday. It does look like we will stay in a cool and wet pattern
for the next 7 days, though details are up in the air.
&&
.AVIATION...Coastal TAF sites began reporting MVFR CIGS this morning
as a broad area of ST/SC expanded over land from the coast and
the coastal plane. Large areas of MVFR/IFR Vis due to haze were
also reported into afternoon at ACV, CEC and the Humboldt Bay
Area. The main weather feature to expect is an approaching cold
front that will pack more energy than recent weather disturbances.
This stronger front will bring rain to CEC in the early evening;
HREF guidance suggests things starting around 03z or maybe just a
little sooner. Models are in agreement that this front will have a
significant wind increase and wind shift as the front passes.
Above ground "increasing north winds" may briefly introduce the
threat of LLWS along the coast by mid-morning. Rain will convert
to showers in the latter morning. /TA
&&
.MARINE...A front is expected to pass through the coastal waters late
tonight bringing fresh to strong northerly breezes. Otherwise,
gentle to moderate northwest breezes should dominate throughout the
week. A strong NW swell has peaked, but will continue throughout the
coastal waters into late tomorrow night generally staying above 10
feet. Another NW swell will move through midweek, peaking at 11 to
12 feet. And yet another NW swell will move through later in the
week, peaking around 8 feet.
&&
.BEACH HAZARDS...A long-period northwest swell will continue to
bring the potential for large breaking waves this afternoon and
evening. Forecast breakers on area beaches should range from 16 to
21 feet and will result in larger than normal surf and possible
beach erosion. A Beach Hazards Statement remains in effect through
this evening. Beachgoers and mariners should continue to exercise
extreme caution and stay vigilant if venturing near the ocean.
&&
.EKA WATCHES/WARNINGS/ADVISORIES...
CA...
Beach Hazards Statement until 9 PM PDT this evening for
CAZ101-103-104-109.
Winter Weather Advisory from 5 AM to 5 PM PDT Tuesday for
CAZ107.
NORTHWEST CALIFORNIA COASTAL WATERS...
Small Craft Advisory until 9 AM PDT Wednesday for PZZ450-
455-470-475.
&&
$$
Visit us at https://www.weather.gov/eureka
Follow us on Facebook and Twitter at:
https://www.facebook.com/NWSEureka
https://www.twitter.com/NWSEureka
For forecast zone information
see the forecast zone map online:
https://www.weather.gov/images/eka/zonemap.png
Area Forecast Discussion
National Weather Service Grand Rapids MI
1056 PM EDT Mon Oct 31 2022
LATEST UPDATE...
Update
.UPDATE...
Issued at 1056 PM EDT Mon Oct 31 2022
Main concern for the overnight is fog and specifically the
potential for dense fog. At this point opting to hold off on a
Dense Fog Advisory given the lack of 1/4 mile visibilities at the
present time. Also, and maybe more importantly holding off due to
the wind increase noted in the 18z models below 1,000 feet
between 06z and 12z. Our thinking is the 10-20 knot winds
developing in that shallow layer may be enough mixing to keep
dense fog from forming and promote more of a stratus deck. Bottom
line, not enough confidence at this point to issue an Advisory.
&&
.DISCUSSION...(This evening through next Monday)
Issued at 227 PM EDT Mon Oct 31 2022
- Risk for locally heavy showers this afternoon into early evening
PWAT values are up around 200 percent of normal with a surface
wave moving in from the southwest this evening. Forecast soundings
are shown to be saturated through the mid levels...especially
near and southeast of Grand Rapids. Radar trends show that where
the showers are....they are not moving very quickly. Surface
convergence is maximized where the showers are developing. Some
instability has developed closer to the MI/IN border...which may
try to pivot slightly north as the surface wave moves in. High res
models have been showing showers increasing over the next couple
of hours. They are also generating small areas of over a half inch
of rain...which seems reasonable. A small risk for an isolated
thunderstorm exists as well. It does look like the showers will
persist into the early evening hours...especially southeast of
Grand Rapids. During the evening the moisture depth does drop off
steadily so that should eventually support a diminishing trend to
the shower activity.
- Dense fog risks into Wednesday morning
Given the recent rain and potential for at least partially
clearing skies...it will not take much cooling to generate more
fog tonight. The HRRR has been showing this trend and it seems
reasonable. Thus we included fog in the forecast for
tonight...mentioned the hazard in the HWO and on social media.
For Tuesday night...a better chance for clearing exists. The winds
will still be light and low levels relatively moist. This may
result in another period of fog that may impact the Wednesday
morning commute.
- Unseasonably warm weather for mid to the start of the weekend
Deep southwest flow sets up for Wednesday into Friday. Even into
Saturday...the surface cold frontal passage looking less likely
for Friday. The temperature at 925 mb rises from around 13 deg C
Wednesday to 14 deg C Thursday and 15 deg C Friday. Some near 70
degree max temperatures are looking possible. As a result we will
be warming up the temperatures...especially Saturday due to the
diminished chance for the frontal passage. With the wind expected
to persist Thursday night we may not fall below the record high
min temperatures for Friday.
- Strong fall frontal passage over the weekend
Several of the deterministic models(GFS and High Res Euro) are
showing a stronger mid to upper level wave tracking in from the
southwest later Saturday night with some indications of a possible
fold in the Trop. The winds at 500 mb make a run at 115 to 120
knots based on the latest runs. Strong surface winds are starting
to show up in the models with an increased risk for values
topping 40 mph around the passage of this wave...later Saturday
night into early Sunday morning. The ensemble wind gust
forecasts from these models are also showing an increasing number
of members with stronger wind gusts...especially the Jackson area.
Much can change between now and when this potential system
arrives...but we will need to monitor the trends closely in the
coming days.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 800 PM EDT Mon Oct 31 2022
Difficult aviation forecast tonight with wildly variable
conditions at the onset. At 00z, conditions range from VFR at GRR
and JXN but we also have below 2 mile visibility at LAN and
ceilings as low as 100 feet at LWA.
The trend tonight should be a deterioration of conditions with
widespread LIFR ceilings once again at most TAF sites by 07z. A
threat of widespread below 1 mile visibilities also exists. A
slight increase in wind between 250 feet and 1,000 feet off the
deck tonight may push conditions more towards a stratus deck vs
widespread 1/4 mile fog. Both are possible though and we will be
monitoring TAFs closely tonight.
A rapid improvement in conditions should occur on Tuesday between
14z and 17z. VFR conditions are expected for Tuesday afternoon.
Light and variable winds tonight will be southwest to west at 5-10
knots Tuesday afternoon.
&&
.MARINE...
Issued at 611 PM EDT Mon Oct 31 2022
We have issued a Marine Dense Fog Advisory for areas south of
Grand Haven through the night. The advisory is valid until 10am on
Tuesday morning. Dew points in the low to mid 50s combined with
water temperatures around the same temperatures has resulted in
dense fog. St. Joseph and South Haven webcams are currently
showing fog and we expect a northward expansion this evening.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...None.
LM...Dense Fog Advisory until 10 AM EDT Tuesday for LMZ844>846.
&&
$$
UPDATE...Duke
DISCUSSION...MJS
AVIATION...Duke
MARINE...Duke
Area Forecast Discussion
National Weather Service Lincoln IL
823 PM CDT Mon Oct 31 2022
.SYNOPSIS...
Issued at 222 PM CDT Mon Oct 31 2022
Clearing skies and light winds will lead to fog development for
parts of central and eastern Illinois tonight and Tuesday morning.
Some of the fog could be dense. After the fog burns off Tuesday
morning, mild and dry weather will dominate the region through
midweek.
&&
.UPDATE...
Issued at 823 PM CDT Mon Oct 31 2022
Main challenge overnight will be with the fog concerns. Low cloud
deck is roughly east of a Danville to Effingham line right now,
and RAP low level RH plots would suggest it would be out of the
area by midnight. 11-3.9 GOES fog satellite data is showing some
rapid fog development this evening in areas from Bloomington to
Shelbyville, where the clearing took place late and there wasn`t
much time to dry out before sunset. This is not being handled well
by the high-res guidance. Such guidance was focused more on the
period after about 2-3 am with dense fog potential south of a
Danville to Taylorville line. After coordinating with neighboring
offices, a Dense Fog Advisory has been issued from about I-55
southeast through 10 am Tuesday. To the west of there, a drier
atmosphere is noted (dew points low-mid 40s) and think there
shouldn`t be as much of a fog issue outside of some of the river
valleys.
&&
.SHORT TERM...(This evening through Tuesday)
ISSUED AT 222 PM CDT Mon Oct 31 2022
Latest water vapor imagery indicated the mid level shortwave was
lifting northeast of the area into western Indiana. Trailing
deformation zone rains have shown a marked decrease in coverage
and intensity between the I-55 and I-72 corridors over the past
couple hours. This trend will continue as the upper support
departs, leaving just a few showers over the eastern half of the
CWA into late afternoon. This will set the stage for decent
Halloween evening conditions with clearing skies, light to calm
wind and temperatures falling through the 50s (about 10 degrees
warmer than last year).
Overnight, winds remain calm and with mainly clear skies and damp
ground from rain the past couple days, conditions will be
favorable for fog development. High resolution guidance points to
areas east of I-55 for more widespread coverage. Will add fog
mention to grids but hold off on an advisory as confidence in
dense fog is not high enough, but this may be added with later
forecast updates.
After morning fog dissipates, skies turn mostly sunny as upper
level ridging quickly builds into the Midwest. By afternoon, 900
mb temps rise to the mid teens C, and will result in highs in the
upper 60s to around 70 degrees.
&&
.LONG TERM...(Wednesday through Monday)
ISSUED AT 222 PM CDT Mon Oct 31 2022
A stretch of nice early November weather looks to dominate the
area Wednesday into Friday as an upper level trough deepens over
the western U.S., allowing downstream ridging to amplify over the
Midwest. Little spread noted on temperatures from ensemble
guidance, leading to high confidence of temperatures running
10-15 degrees above normal through the period. Southwest gradient
flow increases Thursday and Friday, so light winds Wednesday will
turn breezy for the end of the week.
The main weather maker for the extended forecast is a deep cutoff
low centered near the four corners early Friday, which opens and
lifts northeast to the northern Great Lakes on Sunday. Ensemble
guidance offers up timing differences which are typical with a
closed low, which results in an extended period of PoPs from
Friday into Sunday. However a majority of operational and ensemble
runs sans the fastest Canadian/GEM, point to a wave of warm
advection rains ahead of the cold front crossing the region late
Saturday into early Sunday morning. The system appears fairly
dynamic with the upper wave opening and taking on a negative
tilt, along with strong wind fields aloft and a good surge of low
level moisture. Current blended guidance shows no thunder
probabilities but these may be added with later forecasts. Locally
heavy rain also possible with some solutions showing over 1" QPF.
Dry weather and seasonable temps look to move in behind this
system for late Sunday into early next week.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 626 PM CDT Mon Oct 31 2022
A bit of a challenging TAF forecast for this set. Last of the
current IFR/LIFR conditions will be moving out of KDEC/KCMI over
the next hour or two. However, conditions appear favorable for
more fog to form later tonight, as skies clear and winds remain
light. Latest HREF guidance from 18Z shows probability of LIFR
conditions at KCMI around 50-70% by 12Z. However, more recent
deterministic models favor areas a bit further south. Have
included KDEC/KCMI with a period of 1/2SM visibility toward 12Z
with a few hours of MVFR visibilities at the other sites. Once the
fog lifts around mid morning, skies should be mostly clear the
remainder of the forecast period.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
Dense Fog Advisory until 10 AM CDT Tuesday for ILZ038-042>046-
051>057-061>063-066>068-071>073.
&&
$$
UPDATE...Geelhart
SYNOPSIS...25
SHORT TERM...25
LONG TERM...25
AVIATION...Geelhart
Area Forecast Discussion
National Weather Service Memphis TN
929 PM CDT Mon Oct 31 2022
...New UPDATE...
.UPDATE...
Issued at 922 PM CDT Mon Oct 31 2022
Short term guidance has been hinting at less areal coverage and
intensity of fog overnight. This may be caused in part by
dewpoints underperforming across the area. Dewpoint depressions
around the TN Valley and north MS were forecast to be between 0
and 1 degree overnight, but latest obs and trends suggest DPDs
closer to 3 or 4 degrees, which would hinder fog potential. Patchy
dense fog could still certainly develop around 11 or 12Z, but
it`s looking to be a little less widespread now. The HWO covers
this well.
&&
.DISCUSSION...
(This evening through next Sunday)
Issued at 242 PM CDT Mon Oct 31 2022
A split flow pattern will persist across much of the CONUS
through midweek with the polar westerlies generally confined to
the US-Canada border. One shortwave trough is lifting northeast
across IL/IN while a second is moving through the Southern Plains.
Strong southwesterly flow aloft will continue downstream of the
positively-tilted trough axis with the Southern Plains trough
eventually moving across the Mid-South late Tuesday into
Wednesday.
A few light showers (or sprinkles) continue this afternoon, mainly
over West TN. Any lingering precipitation will end quickly by 00z
and cloud cover will scatter out. Moist soil conditions, light
winds, and clearing skies suggest the potential for fog tonight.
Fog may be dense in some areas and may eventually require a Dense
Fog Advisory. Otherwise, expect dry/warmer conditions the next few
days with highs in the 70s and lows mainly in the 50s.
Shortwave ridging will settle over the Lower MS Valley late
Wednesday and Thursday, continuing the dry weather pattern. This
ridge will attempt to build poleward through the Southeast into
the Delmarva area late in the week. Meanwhile, a strong trough
will dig over the western CONUS. This trough looks to bring
inclement weather to the Mid-South over the weekend, but the
aforementioned ridge over the east is expected to slow its
eastward progress. Ensemble clusters indicate that the GEPS
strongly favors a more progressive trough and weaker ridge,
bringing precipitation into the CWA late Friday while the GEFS
and, to a stronger degree, the EPS indicate stronger ridging over
the southeast and a later arrival. Experience is leaning toward
the latter (slower) solution.
This system will lift northeast as it moves out of the Southern
Plains and, like the past few systems, will quickly occlude as it
crosses the Ozarks. Strong kinematics will accompany this cyclone
with 40-50 kts of southerly flow at 850 mb and a meridional 125+
kt jet on its eastern flank. This will result in an uptick in wind
speeds Saturday and Saturday night with breezy conditions
anticipated over most of the area. This system will be filling as
it pulls away from the area, but the main question will be the
quality of the instability in the warm sector. The 12z ensemble
data maintains only very low probability for CAPE greater 500
J/kg. This system bears watching, but the signal for any
significant weather appears muted at this time.
MJ
&&
.AVIATION...
(00Z TAFS)
Issued at 630 PM CDT Mon Oct 31 2022
Main concern is fog formation overnight. Surface dewpoints were
running around 7 degrees F higher over middle TN where a solid
FL060 deck prevailed. This deck should clear near the TN RIver
later this evening, with fog likely likely developing along the TN
River and adjacent river valleys to the west. HREF, NBM shortblend
and HRRR depict greatest potential for LIFR at TUP, but the MKL
TAF is carrying an earlier onset hedge against guidance, due to
proxmity to the TN River and overall climatology.
Given the calm surface winds and weakening westerly flow off the
deck, urban heat island will likely delay and partially alleviate
IFR fog potential after 10Z.
PWB
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...None.
MO...None.
MS...None.
TN...None.
&&
$$
PUBLIC FORECAST...MJ
AVIATION...PWB
Area Forecast Discussion
National Weather Service Melbourne FL
906 PM EDT Mon Oct 31 2022
...New UPDATE, MARINE, AVIATION, HYDROLOGY...
.UPDATE...
Issued at 843 PM EDT Mon Oct 31 2022
Earlier shower and storm activity has diminished over land areas
by 9pm. However, a few showers continue to linger over the
Atlantic waters. Shower chances will persist here overnight and an
isolated storm cannot be ruled out well offshore.
With clearing skies, the main story tonight will be the potential
for patchy fog. The HRRR has taken the idea and ran with it,
blanketing a majority of the area by daybreak. Other mesoscale
models and LAV guidance are a bit more spatially conservative, so
have hedged closer to their solutions. Nonetheless, patchy fog is
expected from around southern Brevard and Osceola Counties
northward, especially along and north of the I-4 corridor. Fog may
become dense at times, with visibilities falling below 1 mile and
even to around 1/4 mile in some locations. Motorists should be
prepared for the potential for rapidly changing visibilities. If
encountering dense fog, reduce your speed, use only your low beam
headlights, and leave extra distance between your vehicle and the
one in front of you.
Any fog that forms will begin to diminish around sunrise, clearing
through the morning hours. Overnight lows in the upper 60s to low
70s, with light winds.
&&
.MARINE...
Issued at 843 PM EDT Mon Oct 31 2022
Generally favorable boating conditions persisting, although
showers will remain possible across the Atlantic waters overnight.
SE winds becoming S towards daybreak, then N/NE into Tuesday
afternoon. Wind speeds remaining around 10-12kts or less. Seas
3-5ft.
&&
.AVIATION...
(00Z TAFS)
Issued at 843 PM EDT Mon Oct 31 2022
Patchy fog is expected overnight tonight across much of the area
from around southern Brevard and Osceola Counties northward. Fog
may become dense at times, with TEMPOs included for IFR/LIFR VIS from
KISM/KMCO/KTIX northward, beginning by around 8Z at KDAB and
KSFB. More minor VIS reductions may be possible for the more
southern coastal terminals. However, VIS should remain VFR/high
end MVFR at these locations. Otherwise, VFR conditions prevailing,
with light winds becoming E/NE at less than 10kts Tuesday
afternoon. A few showers will be possible during the daytime
hours, but coverage is expected to remain low enough to negate a
VCSH mention at this time.
&&
.HYDROLOGY...
Issued at 843 PM EDT Mon Oct 31 2022
The St. Johns river at Astor will remain in Moderate Flood Stage
for the foreseeable future. The river is currently around 3.7
feet and is expected to slowly decline through this week.
Near Deland, the river will remain in Moderate Flood Stage as it
continues a very slow decline this week.
Near Sanford, the river will remain in Moderate Flood Stage through
mid week then is forecast to fall into minor flood stage late this week.
The river is currently at 7.1 feet and will continue a slow decline.
At Geneva above Lake Harney, the river will remain in Moderate Flood
Stage for the foreseeable future. The river is currently at 9.7 feet
and will continue a very slow decline.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 69 85 69 83 / 10 10 10 30
MCO 71 88 71 87 / 10 20 10 30
MLB 71 85 71 84 / 20 20 10 30
VRB 70 87 71 85 / 20 20 10 40
LEE 69 87 70 85 / 10 10 10 30
SFB 71 87 70 84 / 10 10 10 30
ORL 72 88 72 87 / 10 20 10 30
FPR 70 86 70 84 / 20 20 10 40
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...None.
AM...None.
&&
$$
Leahy/Sedlock
Previous forecast discussion...
As of 230 PM EDT Monday...
Showers ending from west to east this evening.
Broad area of lift associated with occluded front emanating
from a decaying cutoff low over the Ohio Valley will gradually
move north and east of the area this evening. This will allow
ongoing shower activity to come to an end. Elevated CAPE, on the
order of 200-600 J/KG has been supporting some of the embedded
heavier downpours, but I have yet to see any in-cloud lightning.
As such, have refrained from adding any thunder to the gridded
forecast...and will leave it out unless trends suggest
otherwise.
In spite of the rain coming to an end this evening, clouds and
areas of fog will likely persist overnight. It may take until
after daybreak Tuesday to get bonafide clearing associated with
deeper mixing in the wake of the current disturbance. Aside
from the airmass being rain cooled, temperatures are expected to
be above normal normal with respect overnight lows
tonight...lows between about 48-55 degrees...a full 10 degrees
above normal. This will set the stage for a warm day Tuesday
once the sun comes out with highs in the 60s/70s...or 5 to 10
degrees above normal.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/...
As of 120 PM EDT Monday...
Surface high pressure builds in Tuesday night, but will quickly be
covered by a closed upper level low by Wednesday. With no return
flow from the Gulf, this low may only cover the area with mid and
high clouds while keeping temperatures close to normal. But still,
with some heating under the cold pool, a stray light mountain shower
or sprinkle is possible Wednesday afternoon.
This low will slide off the Carolina coast Wednesday night. Cool
high pressure will then wedge south into the region on Thursday.
More sun is expected Thursday but northeasterly flow should keep
temperatures near normal for another day.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
As of 135 PM EDT Monday...
Surface high pressure will remain wedged over the area into next
weekend. Meanwhile, heights will increase aloft with an upper level
ridge becoming centered over the region over the weekend. With
abundant dry air and sunshine, afternoon temperatures will warm to
around 10F warmer than normal despite there being a wedge in place.
Rain chances begin to increase early next week as a cold front
approaches the region from the west.
&&
.AVIATION /02Z TUESDAY THROUGH SATURDAY/...
As of 220 PM EDT Monday...
Poor flight conditions tonight...
Low ceilings and fog have arrived behind the rain this evening.
This will continue to be an issue overnight. Likely ceilings
and visibilities will flip flop overnight, with low ceilings
being the dominating impact on flight conditions, but brief
windows of low visibilities also occuring.
Conditions are expected to quickly improve in the morning for
most sites. However, weak upslope flow will keep low clouds in
the west for a good portion of the day Tuesday.
Forecast confidence is average.
Extended Aviation Discussion...
A weak disturbance may bring some mid/upper level clouds for
Wednesday...producing virga, but little or no surface precip
expected. Aside for this disturbance, expect VFR conditions
Wednesday through Saturday with above normal temperatures.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...None.
NC...None.
WV...None.
&&
$$
SYNOPSIS...PM
NEAR TERM...DS/PM/RR
SHORT TERM...RCS
LONG TERM...RCS
AVIATION...PM/RR