Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 11/06/18
Area Forecast Discussion
National Weather Service Charleston SC
910 PM EST Mon Nov 5 2018
.SYNOPSIS...
A warm front will lift north of the area Tuesday. A cold front
will move into the region Tuesday night. The front will become
stationary over the area Wednesday into late week. A stronger
cold front will cross the area by Saturday, followed by a cool
high into early next week.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
06/02z surface map placed the warm front over the southern
Midlands, CSRA into central Georgia with all of Southeast South
Carolina and Southeast Georgia embedded within the warm sector.
Dewpoints remain in the upper 60s/lower 70s, indicative of a
very warm and humid airmass for early November. Expect a mostly
dry night to prevail, although an isolated shower or two could
certainly develop at just about any time given the moisture
levels that are in place. Maintained 20% pops through the
overnight period.
The main forecast concern centers on the potential for widespread
fog and stratus. GOES-E fog product shows widespread stratus
with areas of fog have developed across much of the interior
within a large clearing band between two areas of cirrus. This
area of clearing will contiue to march to the coast, so expect
fog and stratus to build east. Later tonight, southeast winds
are expected to increase, which will tend to erode any fog and
status from southeast to northwest. This trend was captured well
in earlier runs of the RAP and H3R and matches output from the
latest NARRE-TL. Best chances for dense fog look to remain
across interior Southeast Georgia, especially from Reidsville-
Millhaven and points west for most of the night, although
patchier dense fog could occur just about anywhere before the
southeast winds increase.
Temperatures will not change much more given the high dewpoints
in place. Nudged lows up a degree per current trends with most
areas only bottoming out in the upper 60s/near 70.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/...
Tuesday: A warm front will lift north of the region. We will start
the morning with areas of fog and perhaps a few showers, especially
along the coast. Then, ahead of an approaching cold front,
convection should develop upstream and push into the region during
the afternoon. Between these episodes, precipitation coverage should
remain sufficiently to allow temperatures to recover into the lower
to mid 80s away from the beaches, well above normal for early
November and not far from record highs at KCXM and KSAV.
A marginal risk for severe thunderstorms encompasses a large swath
of the forecast area Tuesday afternoon and evening. Strongest
forcing for ascent and the associated greater risk for severe
thunderstorms is expected to pass north and west of the region.
However, sufficient instability/shear could develop to support
isolated damaging wind gusts within multicell clusters of
thunderstorms during the afternoon/evening hours. Nevertheless,
unless thermodynamic/kinematic parameters vary significantly from
forecast values, a significant severe weather event appears
unlikely.
Tuesday night into Wednesday: A weakening/slowing cold front will
push into the region. This will maintain at least isolated/scattered
showers, and isolated thunderstorms cannot be ruled out Tuesday
evening and again Wednesday afternoon. Also of note, the shallow
push of cooler air into a moist environment could support another
round of significant stratus/fog later Tuesday night into Wednesday
morning. Otherwise, expect Tuesday night low temps ranging from 60-
65F inland to around 70F on the beaches, followed by Wednesday high
temps in the middle/upper 70s north to the lower 80s south.
Wednesday night: By this time, the cold front will have
stalled/transitioned to a stationary front just south of the region,
and an associated baroclinic zone will set up over the area.
Meanwhile, a shortwave trough is progged to cross the region while
enhanced low/mid level moisture transport contributes to increasing
low-mid level moisture/PWAT values 1.75-2 inches. As a result,
expect precipitation coverage to ramp up. Latest PoPs are graduated
from high chance inland to likely elsewhere. Higher PoPs could
eventually be required. Also, will continue to assess the potential
for another round of significant stratus/fog.
Thursday: Deep-layered moisture and associated elevated PoPs will
persist, and latest PoPs range from chance inland to likely
south/east. the axis of deep moisture could push south/east of the
region as the shortwave trough exits Thursday afternoon, but this
solution remains uncertain.
Wednesday night and Thursday: Elevated high tide levels and rain
could produce Advisory level flooding in some coastal locations,
including downtown Charleston, especially around the times of the
evening and morning high tides.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
A relatively wet period is in store Thursday night through at
least Friday night, potentially lingering into Saturday morning
as the front remains stalled over the area and several low
pressure waves move along it. Fairly good model agreement that
cool, dry high pressure will expand over the area late Saturday
through Sunday, though another system could potentially affect
our area early next week.
&&
.AVIATION /02Z TUESDAY THROUGH SATURDAY/...
KCHS: MVFR cigs are expected to fill back in by mid-evening with
a period of IFR cigs and possibly some fog in the 03-06z time
frame. High resolution guidance then pushes the IFR or lower
conditions west of the terminal as southeast winds increase.
MVFR Cigs will prevail for much of the night before increasing
to MVFR by mid-morning. Confidence is low to moderate on how low
clouds and fog will evolve this evening.
KSAV: Fog and stratus are expected to redevelop over the
terminal overnight, but there are signals that as southeast
winds increase, lower vsbys could be pushed back to the west.
Maintained IFR cigs redeveloping overnight, but limited fog to
MVFR thresholds for now. Cigs were capped just above alternate
minimums. Confidence is low to moderate on how the fog and
stratus situation will evolve overnight.
Extended Aviation Outlook: Low-level moisture and precipitation are
expected to create periodic flight restrictions of varying magnitude
at both terminals through Friday.
&&
.MARINE...
Tonight: SSE winds 5-10 kt in the evening will gradually
transition to the S or maybe even SSW by daybreak while
increasing to 10-15 kt. Seas will average 2-4 feet, with some 5
footers possible in the offshore GA waters late. Additionally,
land fog could seep towards Charleston Harbor later at night,
possibly causing visibility reductions. But confidence is not
yet high enough to put patchy fog in the Charleston Harbor
forecast.
Tuesday through Saturday: This period will feature frequent wind
shifts. Southwest winds as high as 15-20 knots and seas of 3-5 feet
will prevail Tuesday/Tuesday evening. Then, a cold front will turn
winds to the to northwest then northeast around 10 knots,
accompanied by seas of 2-4 feet, Later Tuesday night into Wednesday.
passing low pressure will turn winds toward the southeast Wednesday
night then toward the northeast Thursday/Thursday night. Of note,
winds/seas could approach Small Craft Advisory levels in some areas
Thursday/Thursday night. Ahead of a stronger cold front, expect
winds to become southeast Friday, then winds will abruptly shift to
the north/northeast as the cold front passes and cooler high
pressure builds over the waters later Friday night/Saturday, and
Small Craft Advisory conditions are expected in most/all areas.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...None.
SC...None.
MARINE...None.
&&
$$
Area Forecast Discussion
National Weather Service State College PA
830 PM EST Mon Nov 5 2018
.SYNOPSIS...
A strong frontal system will sweep through the region on
Election Day. Our active weather pattern will continue with only
a short break Tuesday night into early Thursday, before another
storm system moves in for late in the week.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
The dreary day has continued into the now earlier evening with
widespread low clouds and areas of mainly light rain and
drizzle. The HRRR shows the rain diminishing but forecast
soundings show the low levels remaining saturated with a light
SSE flow, so look for the damp conditions to continue right up
until the time rain overspreads the region ahead of the
approaching frontal system just after sunrise.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/...
The cold front will speed across the CWA Election Day. All
guidance shoves the bulk of the precip off to the east of the
area by noon with the front roughly EWR- PHL- IAD at 18Z. Only
the far SERN sliver of counties could have thunder chc continue
into the aftn if the front drags along. SPC continues to
outlook that area with a SLGT risk, with a buffer of MRGL risk
to the NW about 2 counties deeper into the CWA. If timing
continues to look like the current fcst, this may be too far
north/west. Rain does look heavy at times but QPF has been
lowered. So while soils are saturated and the system is moving
fast, there is a marginal risk for localized flooding. While
most of them would be minor, a few of the river points could
experience significant rises, esp the tribs flowing directly
into the Lower Susq.
The brunt of the cold advection seems to pass to our north. The
fetch off the lakes looks like it would take any lake enhanced
showers Tues night off to our north into wrn NY. Clouds will
linger into the night over the Alleghenies, but might be gone
by Wed AM.
&&
.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
Moderately tight LLVL P-gradient in the wake of the cfront will
help to create gusty WNW winds and cooler air for Tuesday night
right into Thursday.
The falling temps and veering cross-lake fetch will bring some
lake effect rain showers down into the NW part of the CWA, and
could allow for some wet snow with minor accums of a coating on
the higher elevations Wed night as temps dip to near freezing.
mins elsewhere will be mainly in the l-m 30s. Subsidence
inversion base is within 4 kft agl, and cloud temps generally
AOA -6 to -8C, so QPF from the LER/S should be light.
Elsewhere, the period Tuesday night through early Thursday night
will afford generally dry conditions with temps near to a few
deg F above normal Wednesday, then slightly lower heights
aloft/thicknesses will help drop daytimes max temps to at least
several deg F below normal on Thursday with maxes mainly in the
40s and l50s.
Interesting pattern for Friday with a good chc for mainly clear
skies initially over the NE half of PA, and relatively cold air
in place - at least at LLVLs as 1030 mb sfc high pressure drifts
just NE of the state.
A nrn stream wave tries to phase with srn stream moisture. A
low develops in the Coastal Carolinas and heads NE. Many GEFS
members generate what could be a few hour period of accumulating
snow (or at least the threat for mixed precip) for the nrn
Alleghenies Fri/Fri night, and mainly rain following a brief
period of wet snow or mixed precip elsewhere. Latest 05/12Z
operational runs of GFS and EC remain supportive of this too,
though the thickness fields and onset timing of the precip later
Friday morning paint less of a threat for frozen precip.
A return to brisk, chilly and generally dry weather with just
some minor LES mixed rain/snow showers across the NW mtns will
follow for Sat into next Monday.
&&
.AVIATION /01Z TUESDAY THROUGH SATURDAY/...
A moist southeast flow over central Pa will result in
predominantly ifr/lifr cigs overnight. Some places are still
reporting mvfr cigs early this evening, but some modest
nocturnal cooling should cause even those locations to
transition to ifr cigs later tonight.
A frontal boundary will push through the area between 15Z-20Z,
preceded by several hours of rain, continued low cigs and
possible llws. Behind the front, expect clearing skies with a rapid
improvement to vfr and increasingly gusty southwest winds
Tuesday afternoon. Model soundings support afternoon gusts of
25-30kts over northwest Pa and 15-20kts across the southeast
part of the state.
.Outlook...
Wed...Gusty west winds possible.
Thu...No sig wx expected.
Fri...Rain/low cigs/llws possible.
Sat...No sig wx expected.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SYNOPSIS...Dangelo/La Corte
NEAR TERM...La Corte/Ceru
SHORT TERM...Dangelo/Ceru
LONG TERM...Lambert
AVIATION...Fitzgerald
Area Forecast Discussion
National Weather Service Grand Rapids MI
647 PM EST Mon Nov 5 2018
LATEST UPDATE...
Aviation
.SYNOPSIS...
Issued at 309 PM EST Mon Nov 5 2018
Steady rain moves in tonight and lasts through tomorrow morning
before fading to lighter showers. Gusty winds will likely develop
on Election Day, starting late in the morning and lasting into the
afternoon. A mix of rain and snow may impact the lake shore region
mid week with minor impacts expected. Snow showers will likely
impact our region Friday into early Saturday with some
accumulations possible as a cold blast of air moves in. After a
short break, another shot of cold air and some snow showers may be
in the offing for early next week.
&&
.DISCUSSION...(This evening through next Monday)
Issued at 309 PM EST Mon Nov 5 2018
The main items of interest continue to center on wind gust
potential on Tuesday along with a transition into a wintry
pattern later this week and into the weekend.
Rain still looks on track for tonight into Tuesday morning as an
area of low pressure approaches Chicago and eventually tracks over
Lake Michigan and deepens as it heads northeast, likely around
992 mb over Lake Huron by Tuesday morning or early afternoon. A
general half inch to three quarters of an inch of rain is expected
with this system. More impressive than the rainfall will be the
winds generated by cold air advection sweeping through the region
on the back side of the low. Mixing heights don`t look terribly
impressive, likely on the order of 1500-2000 ft or so, but it
won`t take much to mix down strong wind gusts.
Model soundings reveal a fine line between 30-40 mph sfc gusts and
40-50 mph, based on the depth of mixing and how strong the
925-850 mb winds are. This varies by model in spite of overcast
skies limiting the depth of mixing. For example, the NAM 3km has a
more conservative mixing height during the late morning and
afternoon while the RAP is more aggressive. This makes the
difference in power outage potential and hence whether we need a
Wind Advisory or not for Tuesday. Our in-house blend of models
indicates 30-40 mph will be the most likely (particularly near and
south of I-96), and this seems like a reasonable compromise given
model differences in mixing heights. The strong winds may begin
as early as mid to late morning and last through the afternoon.
Some branches may come down and there may be some isolated power
outages on Election Day. We will keep an eye on trends.
Light rain and snow showers are possible Wednesday into early
Thursday along the lake shore and by U.S. 10 as well, with
generally limited impacts expected, although some snow may stick
Wednesday night with perhaps some slick spots east of Ludington
and Pentwater and toward Reed City and Baldwin.
Models continue to advertise -10C to -15C at 850 mb later Friday
into Saturday as a fairly strong 500 mb shortwave trough zips
through the Great Lakes region. This may help lift a weak area
of low pressure into Ohio that could bring light snow to the region,
possibly mixed with rain to start (before the colder air
arrives). Temperatures initially in the mid to upper 30s will
quickly fall to below freezing in the evening and continue their
descent into the low to mid 20s Friday night. Lake effect snow
showers look likely Friday evening and into Saturday morning.
Conservatively taking -12C at 850 mb over the lake would yield
delta Ts of over 20C, given current lake surface temperatures.
Looking at RH and omega within the -12C to -18C (DGZ), the FV3 is
showing favorable conditions near and west of U.S. 131 for lake
effect snow bands Friday evening and Friday night. The heaviest
snow may end up staying further north of our region toward Grand
Traverse Bay and toward Grayling/Gaylord. Nevertheless, at least
some light accumulations are possible for our traditional
northwest flow regions.
Rising heights on Saturday should shut off the snow showers but we
may struggle to reach the mid 30s. The cold air may last into
early next week (perhaps worsen?) with additional periods of lake
effect snow showers. The ECMWF/GFS/FV3 are in general agreement
with this pattern though the GEM is not. At this point, the odds
currently favor below normal temperatures and occasional snow
showers.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 647 PM EST Mon Nov 5 2018
A developing storm system will track into the Southern Great Lakes
tonight and the center of the storm will track through the Detroit
area during the mid morning hours of Tuesday. This storm will
bring a variety of hazards tonight to Southwest Michigan. Expect
moderate to heavy icing above 9000 ft agl tonight and above 7000
ft agl Tuesday during the day. Also expect moderate to severe
turbulence above 7000 ft tonight into the mid morning hours of
Tuesday. During the day Tuesday the strong winds will cause
moderate to severe mechanical turbulence.
Beside those hazards a band of moderate to locally heavy rain will
develop and move across our TAF sites in the 04z to 09z time
frame. The MKG and GRR taf sites should see the heaviest rain and
thus the lowest cigs/vis... LIFR is more than possible. Once the
occluded front comes through around 12z winds will become
southwest and increase in speed. The steady rain will end but
shows and IFR/MVFR conditions will likely prevail into the
evening. All sites will see wind gusts in the 25 to 35 knot range
during the day hours but the LAN and JXN taf sites may see gusts
to near 40 knots.
&&
.MARINE...
Issued at 309 PM EST Mon Nov 5 2018
The SCA continues through 7pm this evening and we have gone ahead
with the Gale Warning (all zones) for Tuesday and Tuesday night.
The highest winds will likely be south of Whitehall with this
event where over 40 knots may be commonplace. Waves may reach or
even exceed feet with this event. Even though winds subside below
gales on Wednesday, waves will remain high, on the order of 6 or 7
feet potentially.
&&
.HYDROLOGY...
Issued at 1031 AM EST Mon Nov 5 2018
Rain through Tuesday night will likely cause within bank rises on
area rivers, but no rivers are expected to rise above flood stage.
We may see some ponding of water however, especially in low-lying
and poor draining areas by Tuesday.
Up to a half inch of rain fell last night into this morning. This
afternoon should be dry, but another round of rain will lift across
the area tonight and Tuesday. Rain may be heavy at times. Rainfall
totals with this system look to range between 0.5 and 1.0 inches.
Lake-effect showers will occur from Tuesday night into the weekend.
Rain/snow amounts look fairly light through Thursday night, but we
may see some snow accumulations Friday and Saturday. This should
have little impact on area rivers, and temperatures will not yet be
cold enough to worry about rivers freezing or ice jams forming.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...None.
LM...Small Craft Advisory until 7 PM EST this evening for LMZ844>849.
Gale Warning from 7 AM Tuesday to 1 AM EST Wednesday for
LMZ844>849.
&&
$$
SYNOPSIS...Hoving
DISCUSSION...Hoving
AVIATION...WDM
HYDROLOGY...63
MARINE...Hoving
Area Forecast Discussion
National Weather Service Jacksonville FL
752 PM EST Mon Nov 5 2018
.UPDATE...Radar continues to show a few showers and isolated
thunder across se GA...and virga/sprinkles with higher clouds
across ne FL. Recently, radar has shown an increasing area of
showers over the NE Gulf of Mexico and the westernmost counties
of the northern FL peninsula. The latest HRRR suggests, although
late by a few hours, these showers will spread E and NE across
NE FL thru 06z...then offshore after 06z. Have updated the hourly
POP/Weather grids to reflect this evolution...with decreasing
showers further north. Current mild low temperature forecast
Tonight supported by latest consensus guidance.
&&
.AVIATION...Maintained potential for showers and MFVR CIGs thru
04Z in latest TAFs...though that may need to be extended beyond
04Z for easternmost TAF sites. May see patchy light fog across
the TAF sites, but potential for more significant fog appears
less than last night per latest guidance.
&&
.MARINE...No significant changes planned in next CWF issuance.
Moderate southerly flow expected through Tuesday with 2-4 ft
nearshore seas and 4-5 ft offshore seas.
Rip Currents: A southeasterly ocean swell will reach area waters
on Tuesday, keeping a moderate risk in place through at least
midweek.
&&
.PRELIMINARY POINT TEMPS/POPS...
AMG 68 83 67 81 / 20 50 30 50
SSI 70 81 69 80 / 30 20 30 30
JAX 70 85 69 84 / 30 20 20 30
SGJ 71 83 71 83 / 30 10 10 30
GNV 69 85 67 86 / 30 20 10 30
OCF 69 86 67 86 / 20 10 10 20
&&
.JAX WATCHES/WARNINGS/ADVISORIES...
FL...None.
GA...None.
AM...None.
&&
$$
Wolf/Bricker
AREA FORECAST DISCUSSION
National Weather Service Jackson KY
1042 PM EST Mon Nov 5 2018
.UPDATE...
Issued at 1042 PM EST MON NOV 5 2018
The initial slug of showers is now moving across portions of the
Bluegrass at this late evening hour. The amounts have generally
been in the quarter of an inch pre hour range. The line of
convection we have been discussing for many days now has developed
and is pushing east into south central Kentucky this hour. This
did prompt a mesoscale discussion from the SPC discussing mainly
the wind threat, since you can see some bowing segments embedded
within this line. The chances of seeing this will be mainly toward
the Lake Cumberland region based on the radar trends and should
make it into this area by around 6Z to 7Z timeframe. We have seen
some instances of gusty winds out ahead of the convection mainly
in the 20 to 30 mph range, but some higher gusts remain possible
even ahead of this line of showers and thunderstorms. There is
some potential for isolated flooding of low lying areas, but the
overall forward speed of this is expected to pick up and this
should mitigate more widespread issues. Updated the grids to
better reflect the latest radar trends and hires guidance trends.
Also, still seeing some temperature splits in the far east, but as
winds increase temperatures will rise closer to the rest of the
area.
UPDATE Issued at 718 PM EST MON NOV 5 2018
The latest scans of the WSR-88D shows an area of showers and
thunderstorms moving into portions of western and central Kentucky
this evening. This activity has been slow to progress east as the
upper level trough become more negatively tilted across the
Midwest. The HIRES models are in good agreement taking this
initial slug of moisture northward and bring a line of showers
and thunderstorms through the region late this evening into the
overnight hours. The HRRR might be a little slower in the latest
runs and this will have to be monitored for subsequent updates.
Did introduce higher POPs a little earlier north of I-64, with
this initial slug of moisture. Otherwise more minor adjustments to
the overall POPs at this time. Now in terms of winds, they have
been slow to mix down in the western portions of Kentucky, and the
models may be a little overdone on the jet at this time based on
some of the VAD wind profiles. Either way it will only take on
decent storm or heavier shower to mix down the stronger winds
aloft through the late evening and overnight. Finally, the only
other issue addressed this evening is the clouds are not keeping
the far east from decoupling this evening and made some
adjustments to the temperature curve to better handle this idea.
&&
.SHORT TERM...(This evening through Tuesday night)
Issued at 459 PM EST MON NOV 5 2018
Late this afternoon, low pressure was developing over the mid
Mississippi valley. In the mid/upper levels, an associated impulse
was rotating through a large longwave trough over the CONUS. The
surface low will rapidly deepen as it moves north to the Great
Lakes as its associated upper level support ripples through the
larger scale trough. The low will propel a cold front east
through KY, with advection of mild/moist air occurring ahead of
it, underneath the advancing impulse. This will produce showers as
the cold front moves in tonight, and possibly some thunderstorms.
Deep layer instability will be weak. However, shear will be
exceptional, with an abundance of strong winds aloft. This will
present a threat of strong/damaging winds should the convection be
able to mix environmental flow aloft to the ground. The main
factor seems to be whether the lack of significant surface based
instability can be overcome in order to get winds to the surface.
Even outside of thunderstorms, it will become breezy, especially
as the cold front pushes through.
Some showers could linger into Tuesday morning, but will end
quickly, as surface ridging builds in from the west and southwest
and provides fair weather through the remainder of the short term
period.
.LONG TERM...(Wednesday through Monday)
Issued at 459 PM EST MON NOV 5 2018
The models are in good agreement with the upper level pattern for
the extended. A wave will move through Wednesday, bringing the
possibility for showers mainly for southeastern Kentucky into the
afternoon and through the evening. Near-zonal conditions will then
take hold until late week when a northern stream trough moves over
the central CONUS towards the Ohio Valley. This trough will move
through the Ohio Valley Friday and into early Saturday. Closer to
the surface, high pressure will dominate until a cold front moves
through Friday. This, along with strong upper level dynamics, will
bring at least likely PoPs for eastern Kentucky Friday morning and
into the afternoon, decreasing through the evening. High pressure,
and thus drier conditions, will again take hold for the remainder of
the weekend. Another system will approach the Commonwealth Monday,
but as this is at the end of the forecast period, there is greater
uncertainty. Future model runs will be monitored for the development
of this system.
High temperatures will begin in the mid to upper 50s Wednesday, but
then be on the decrease through late week. After the passage of the
cold front later on Friday, highs Saturday will range from the low
to upper 40s. Highs will then generally be around 50 degrees into
the start of next week. Low temperatures will be below normal
throughout the period, with the coldest lows occurring Saturday and
Sunday mornings. Also, due to clear skies and light winds, have
included the potential for ridge/valley temperature differences
Thursday and Sunday mornings. Colder valleys are possible Saturday
morning as well, but greater surface winds with frontal passage may
inhibit the decoupling of valleys.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
ISSUED AT 621 PM EST MON NOV 5 2018
The period is starting off VFR ahead of an approaching strong
storm system. However, conditions will worsen as showers and
thunderstorms along and ahead of a cold front progress toward and
move across eastern Kentucky tonight. The CIGs and VIS will drop
to MVFR, with IFR possible at times in heavier showers and
thunderstorms late this evening through tonight. There is a
strong low level jet associated with this system, and despite the
elevated winds at the surface added some LLWS to all the TAF sites
this evening into tonight. That said, winds will be most gusty in
heavier showers and thunderstorms along and near the cold front,
with gusts of 20 to 30 knots possible at times. It will remain
gusty even into Tuesday with gusts of 15 to 20 knots through the
day. The TAFs will return to VFR by late Tuesday morning into
Tuesday afternoon.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...DJ
SHORT TERM...HAL
LONG TERM...CGAL
AVIATION...DJ
Area Forecast Discussion
National Weather Service Marquette MI
650 PM EST Mon Nov 5 2018
.SHORT TERM...(This evening through Tuesday)
Issued at 259 PM EST MON NOV 5 2018
WV imagery and RAP analysis indicated a mid/upper level trough
through the central CONUS. An upstream shortwave trough and
associated sfc low was moving into western IA. Rain associated with
this feature was gradually lifting northeastward from IA and srn
MN. Otherwise, despite weak sfc riding moving into the area from nrn
WI, abundant low level moisture persisted below a 3k-4k ft
inversion.
Tonight, the models suggest that the pcpn will continue to gradually
spread into mainly the west and south by late this evening. There is
more uncertainty with how far or quickly the pcpn will spread
into the rest of Upper michigan overnight. So, only chance POPs
were included over the north and east. Forecast wet-bulb zero
heights suggest that any pcpn will fall predominantly as rain
despite temps remaining nearly steady in the mid 30s over the
inland west. Overall rain amounts will remain light, generally at
a tenth of an inch or less.
Tuesday, the strongest isentropic lift and 700-300mb qvector conv
associated with the shrtwv and sfc low is expected to remain well to
the southeast of Upper Michigan. However, areas of rain should still
persist through the day as sfc troughing and weaker 700-300mb
qvector conv remain over the area ahead of another shrtwv moving out
of the nrn Plains. There may be periods through the day, especially
north central, where there is little measurable rain, with just some
patchy drizzle.
.LONG TERM...(Tuesday night through Monday)
Issued at 302 PM EST MON NOV 5 2018
Busy extended forecast with the first good shot at accumulating lake
effect snow showers later this week and chances for widespread
precipitation as multiple systems track across the Upper Great
Lakes. Each of these systems will bring bouts of colder air down
from Canada. By the end of the work week and into this weekend day
time highs will struggle to reach the freezing mark, with overnight
lows expected down into the teens. During times when colder
temperatures combine with gusty winds, it certainly may become
blustery at times.
Wednesday through Friday, widespread lingering rain and snow are
expected as upper-level energy continues to slowly exit the region.
Behind this system, as 850mb temperatures cool down to around -8 to -
10C, lake enhanced snow showers will develop across the northwest
wind snowbelts downwind from Lake Superior. With lake induced
instability increasing and lingering large-scale lift, wouldn`t be
surprised if the lake effect snow falls moderately at times. Later
Wednesday night through the day Thursday, 850mb temperatures cool
further to around -11 to -13C. This will favor an uptick in the
intensity of ongoing lake effect snow showers. Late Thursday, lake
effect snow showers across the west half will push offshore as flow
backs southwesterly ahead of a troughing pivoting east across the
region. Still expect lake effect snow to linger across the east half
where flow will be slower to respond to this change. As the trough
pushes eastward on Friday, large-scale lift will increase and allow
for another chance for light snow across much of the area. With even
colder air progged to arrive behind this system late Friday, should
see efficient, moderate to perhaps heavy lake effect/enhanced snow
and the potential for some blowing snow, after it starts to
accumulate on the surface, near Lake Superior where gusty northwest
winds are possible.
This weekend into early next week, there is quite a bit more
uncertainty in how things will unfold with yet another system
progged to track across the Upper Great Lakes. Regardless, there
will be moderate to perhaps heavy lake effect snow showers ahead of
and behind this system, mainly across the northwest wind snow belts.
Where snow has accumulated on the ground, could see some issues with
blowing snow arise if the arrival of cold air and breezy northwest
winds come to fruition early next week.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 649 PM EST MON NOV 5 2018
MVFR conditions will prevail thru the evening at KIWD/KCMX/KSAW.
With a low pres system tracking ne into the Great Lakes tonight into
Tue morning, -ra will spread into the area, beginning first at KIWD
this evening, and then potentially at KCMX/KSAW overnight. Along
with the -ra, expect conditions to fall to IFR at KIWD overnight and
at KSAW Tue morning. IFR or low MVFR conditions will be the rule on
Tue under ocnl -ra.
&&
.MARINE...(For the 4 PM Lake Superior forecast issuance)
Issued at 259 PM EST MON NOV 5 2018
No gale events are expected through Thursday. Winds will continue to
diminish tonight to less than 15 knots Tuesday as the pressure
gradient relaxes with broad troughing expected to develop over Lake
Superior. Winds become northwesterly 20 to 30 knots Tuesday night
through Thursday as colder air moves through the northern Great
Lakes. From Friday into the weekend, north to northwest gales could
develop with a stronger push of cold air into the region behind a
cold front and strengthening low pressures system.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
None.
Lake Michigan...
None.
&&
$$
SHORT TERM...JLB
LONG TERM...Ritzman
AVIATION...Rolfson
MARINE...JLB
Area Forecast Discussion
National Weather Service Nashville TN
910 PM CST Mon Nov 5 2018
.UPDATE...
FOR EVENING DISCUSSION.
&&
.DISCUSSION...
Updated suite of forecast products to mention Tornado Watch Number
423 thru 06/09Z (3 AM CST) in zone forecast product. Latest HRRR
model depicting best squall line movement west to east across mid
state region and adjusted hrly grids with wx and pops
accordingly. Highlighted mention of damaging winds, tornadoes, and
heavy rainfall with this squall line as it moves across the mid
state region. Nashville Metro area continues to look like it will
be influenced by this squall line event between 10 PM CST and 1
AM CST. Tweaked hrly temp, dewpoint, and wind speed/direction
grids. Current temps trends in line with forecasted lows.
Remainder of forecast continues to be on track.
.AVIATION...
00Z TAF DISCUSSION.
CKV/BNA/MQY/CSV...Went very close to 18Z TAF discussion reasoning.
Several amendments probable at all terminal sites due to actual
fluctuations in wx, wind, vsbys, and ceilings thru at least
06/10Z. Reason behind this is that there is no way with forecast
wx resolution to do these very short term time period deviations
accurately in a concise terminal forecast format. One significant
change of note though is the introduction of LLWS with 60kts of
shear within 2 KFT of sfc. Preliminary data from 06/00Z OHX
sounding sounding profile depicting 50-60kts winds as close as 200
feet off sfc. Significant caution is urged for any aviation
interest across the mid state region thru 06/10Z. Latest models
continuing to support designated TEMPO group impacts and timing
windows of potential strong/svr tstms of a potential squall line
feature moving across terminal locations. During these TEMPO time
periods sfc gusts 40 to 50 kts if not locally higher are certainly
not out of the question. Sly sustained sfc winds 10-15kts with
gusts to 25kts will veer to the west as sfc cold front moves into
northwest portions of mid state by 06/04Z and proceeds
southeastward across and out of mid state by 06/12Z. Conditions
should rapidly improve to VFR/SKC conditions all terminals
06/14Z-06/24Z as sfc high pressure influences and a dry quasi swly
flow pattern becomes established across mid state region.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
DISCUSSION......31
AVIATION........31
Area Forecast Discussion
National Weather Service Pocatello ID
551 PM MST Mon Nov 5 2018
.SHORT TERM...Tonight through Wednesday. A quick update early this
evening to account for the band of showers extending from Taber into
the ERN mountains. The HRRR and to a lesser extent the UofA WRF both
show persistent shower activity over the mountains east of Blackfoot
and Idaho Falls through the evening with perhaps 1 to 3 inches of
accumulation at the higher elevations. See the previous discussion
below for more information. Huston
Isolated to scattered showers beginning to blossom through the area
near the Montana Divide. These will continue through the evening,
fueled by steepening low-level lapse rates. Persistent northwest
flow and continual moisture stream will keep showers in the forecast
through Wednesday, particularly from near Challis through Island
Park and stretching southward towards Bear Lake.
Terrain enhancement is expected with incremental snow accumulation
expected above 4000 - 5000ft. By late Wednesday, accumulations to
near half a foot is expected for near Pine Creek Pass and Targhee
Pass near Island Park. The long duration of the snow accumulation
precludes any need for Winter headlines.
Gusty west-southwest winds today will dissipate tonight and into
Tuesday as the pressure gradient begins to slacken. Daily high
temperatures will hold steady below averages through at least
Wednesday as the northwest flow maintains its grip on our area.
TAX
.LONG TERM...Wednesday night through Monday. This persistent
northwest flow pattern persists into the early part of the weekend.
We should dry out actually for Thursday and Friday. By late Friday
and Saturday, the models still want to drop another storm across the
Divide and potentially farther southwest across the state. The
ensembles and Blend of Models keep light precipitation (mainly snow)
going across the central mountains and eastern highlands very much
like we`ve seen for the past several days. The GFS has been
consistently farther southwest across the Divide, while the ECMWF
has been more consistent with it just brushing the Divide. We still
are leaning with the Blend of Model guidance, although limited the
snow chances across eastern highlands south of the Big Holes and
Palisades through Saturday. The models have been struggling even
more for Sunday and Monday, flip flopping between northwest flow on
the east side of the ridge or it still moving directly overhead. The
Blend of Models actually seems to have suddenly flipped to the
wetter scenario, which seemed to be heavily based off the European.
We actually went the other way and kept it dry across the region.
Precipitation amounts on a daily basis will remain light unless
there is a heavier shower or burst of snow. Winds aren`t expected to
be too strong, so any impacts related to wind will be minimal at
best. Temperatures remain below average for this time of year. Keyes
&&
.AVIATION...Northwest flow continues across eastern Idaho. We will
see occasional showers in similar places as we`ve seen in recent
days, favoring the eastern highlands and central mountains from
around Galena to Gilmore Summits. In terms of VCSH or actual -SHSN,
the only airports we see affected are KDIJ and KIDA. If a shower
happens to impact an airport directly, there could brief drops in
visibility/ceilings to MVFR or IFR and gusty winds. Otherwise,
expect VFR at this sites and all of the other TAF locations as well.
More widespread stronger winds will persist until sunset before
dying off rather quickly. Keyes
&&
.PIH WATCHES/WARNINGS/ADVISORIES...None.
&&
$$
Area Forecast Discussion
National Weather Service Raleigh NC
945 PM EST Mon Nov 5 2018
.SYNOPSIS...
An in-situ cold air damming high will extend across the central and
western Carolinas and VA through early Tuesday. A warm front will
briefly retreat northwestward into portions of central NC midday
through mid-afternoon Tuesday, ahead of a pair of cold fronts that
will cross the region late Tuesday afternoon and evening. Weak,
Pacific high pressure will follow for Wednesday.
&&
.NEAR TERM /THROUGH TONIGHT/...
As of 945 PM Monday...
A southerly flow a few thousand feet above the surface will
strengthen overnight as a well defined s/w and attendant sfc cold
front approach from the TN Valley. This sly flow will continue to
pump a warm moist air mass over the relatively cool stable air mass
near the surface, resulting in extensive low clouds along with
patchy drizzle/light rain and areas of fog. Potential for the fog to
become dense, especially over the Piedmont and adjacent sections of
the Sandhills overnight into early Tuesday. Latest HRRR suggest the
dense fog becoming prevalent after midnight. If HRRR trend verifies,
will likely need to go with an advisory after midnight.
The extensive cloud cover and a slow erosion CAD air mass in place
will lead to temperatures holding steady or slowly rising through
the overnight. By daybreak Tuesday, most locations should see
temperatures in the 60-65 degree range. If the rain coverage is
greater than anticipated overnight, this may actually "cleanse" the
atmosphere, temporarily reducing the threat for dense fog.
&&
.SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/...
As of 314 PM Monday...
The main player in our weather for Tuesday will be the approach and
passage of the cold front that is currently moving across the
Plains. As mentioned in the near-term, increasing S/SW flow ahead
of this front will mean gradual warming, but being that the CAD is
always slow and tough to erode, the best low level destabilization
is expected to occur across the eastern half of our CWA during the
daytime prior to the front. Most CAMs suggest a classic pre-frontal
band of showers and tstms will sweep across central NC from west to
east...first across the Triad and our western zones around mid-day,
the central Piedmont, Sandhills and the Triangle during the
afternoon, and finally across the I-95 corridor during the early
evening. In terms of severe potential, as mentioned, the best
instability will be across the eastern half of our CWA, but deep
layer bulk shear will be more than adequate (> 40kts) across our
entire CWA. Also noted that even where the CAD erodes and low level
warming occurs, forecast soundings depict several modest but
apparent inversions above the BL. Nevertheless, given the recent
rains and wet soils, event modest wind gusts assoc with any decent
convection that gets going...can result in a couple...perhaps even
several...downed trees across our CWA...with again the best chance
for severe convection across the eastern half of our CWA where it
will be the warmest.
Subsidence, drying, and CAA will commence in the wake of the cold
fropa Tuesday evening and night, with clear skies by sunrise
Wednesday.
Temp forecasts are always a challenge during the CAD erosion
timeframe, but attm is appears that readings may climb to around 70
across the Triad, to around 80 across our SE zones. Lows Tuesday
night from the mid 40s NW to mid 50s SE.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY NIGHT/... As of 235 PM
Monday...
Wednesday through Thursday: There`s quite a bit going on in the
extended forecast period. Expect the stalled cold front along the
Carolina coast on Wednesday to slowly retreat northwestward through
Thursday. Aloft, a very broad northern stream trough will extend the
width of the CONUS, amplifying over the Northern Rockies and High
Plains on Thursday. Perturbations along the surface boundary may
enhance some of the rainfall expected over the Carolinas. However,
the westward extend will depend on the location of the front. The
northwestern portions of the area will remain wedged in. The
location of the front and the wedge airmass will also impact
temperatures across the area. For now, expect highs within a
category of normal on Wednesday, upper 60s NW to mid 70s SE. Lows
may still be a bit above normal Wednesday night, upper 40s to mid
50s. As would be expected Thursday temperatures will be lower than
Wednesday, highs in the low to mid 60s and lows in the mid 40s to
low 50s.
Thursday night through Saturday: The upper level trough will
continue to amplify over the Midwest on Thursday and Friday, with a
front strengthening over the Gulf and Southeast. The front should
move through the Appalachians and into central NC Friday or Friday
night, eroding the weak wedge across the west and resulting in
another round of showers across the area. Best chances for showers
will come during the day and evening Friday, though will likely
start Thursday night over western NC and linger into Saturday
morning across the far east. As for temperatures, with little time
to warm in the NW, highs on Friday may only get into the mid 50s,
while farther to the southeast highs may approach 70 degrees. Lows
will be impacted by the timing of the front, but largely expect
upper 30s NW to mid 40s SE. Highs Saturday will likely top out in
the 50s.
Saturday night through Sunday night: Expect west to southwesterly
flow aloft as the trough axis broadens again, extending from New
England to TX. The surface high dives southward from Canada to the
ARKLATEX region through Saturday before building eastward. There is
uncertainty how efficiently it will cross the Appalachians, thus
adding to the uncertainty in the temperatures and weather for the
remainder of the weekend. For now, expect highs similar to Saturday,
however lows in the 30s are expected both nights across the area,
with some below freezing lows in the NW possible. Wind chills may
also be an issue, but will depend on the position of the high.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
As of 715 PM Monday...
Mainly IFR ceilings in cntl NC this evening, aside from lingering
MVFR ones near and especially southeast of FAY, will lower into LIFR
range --with areas of drizzle and dense fog-- overnight, amidst a
well-entrenched (in-situ) cold air damming air mass. The southeastern
edge of the aforementioned cold air damming regime will be marked by
a warm (wedge) front; and this front will retreat nwwd into cntl NC
and cause low ceilings and fog to slowly lift and disperse from
southeast to northwest, with a following breezy swly wind. That
front, and those more-markedly improving conditions to VFR, are most
likely to affect FAY and RWI, and least likely to affect Piedmont
sites, prior to the passage of a band of showers and storms and
related sub-VFR conditions and strong wind gusts. As such, Piedmont
sites, particularly INT and GSO, are likely to remain sub-VFR
throughout the 00Z TAF period, with only a brief improvement to VFR
possible at RDU.
Outlook: VFR conditions will follow area-wide, as high pressure
builds in behind the front later Tuesday night-Wednesday, though
patchy fog and/or low stratus cannot be entirely ruled out around
daybreak Thu, particularly at FAY. The nwwd retreat of that same
frontal zone will cause sub-VFR conditions and showers to return to
srn NC, including perhaps as far north as FAY, Wed night, then
otherwise and elsewhere Thu night and Fri.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SYNOPSIS...MWS
NEAR TERM...WSS
SHORT TERM...np
LONG TERM...KC
AVIATION...MWS