Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 11/01/24
Area Forecast Discussion
National Weather Service Cheyenne WY
715 PM MDT Thu Oct 31 2024
.KEY MESSAGES...
- Potentially brief high winds possible over the wind prone
areas of southeast Wyoming this morning and again on Friday
morning.
- The potential for more snowfall is expected to develop over
the area on Sunday night and continue into Monday morning.
&&
.UPDATE...
Issued at 714 PM MDT Thu Oct 31 2024
The High Wind Warning for the North Snowy Range Foothills ended
at 6 PM.
&&
.SHORT TERM /THROUGH SATURDAY NIGHT/...
Issued at 205 PM MDT Thu Oct 31 2024
Leeside trough lays along the east slopes of the Laramie Range
this afternoon that extends north onto northeast Wyoming and
central Montana. West of this trough...winds have come up in the
Arlington forecast zone with 62 mph reported at Foote Creek.
High wind guidance showing decreasing Craig to Casper 850/700mb
height gradients through the afternoon. But was forced to issue
a High Wind Warning for WYZ110 at least through 00Z this
afternoon. Further west...a 1013mb surface low located over
southern Idaho...with a cold front extending into central
Nevada.
See some energy from the upper low to our west this evening.
HRRR and RAP simulated radar showing some light snow showers
developing across northern Carbon County this evening...so kept
some low chance (30%) PoPs across Carbon County for this evening
before that energy shifts northeast after 09Z Friday.
Worried a little about strong winds once again Friday morning as
GFS 700mb winds increase to 50kts across the Laramie Range. High
wind guidance not showing a high wind event. But given what
happened today...evening and overnight shift may want to
consider a high wind warning for Bordeaux and possibly
Arlington again. Best zone looks to be Bordeaux as the strongest
wind max located right over WYZ106. It will be short
lived...maybe 09Z to 15Z Friday.
Temperatures at 700mbs roughly 3 to 4C warmer Friday over
today...so afternoon temperatures expected to be a bit warmer
over today. Warmer Saturday as 700mb temperatures climb to 0
to +4C. Corresponding afternoon highs in the low 60s across the
Panhandle and upper 40s to mid 50s west of the Laramie Range.
Next shortwave approaching Saturday night as an open trough
approaches from the west. Start to see PoPs increasing across
Carbon County Saturday night and have continued chance (30-40
percent) for Carbon County.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
Issued at 317 AM MDT Thu Oct 31 2024
Sunday is expected to be our transition day as cyclogenesis
begins in response to the stronger jet streaks lifting quickly
northeast ahead of the trof. There is a possibility that the
Nebraska panhandle could experience a fairly nice day with
afternoon highs approaching 60, after the low level inversion
breaks down and erodes the cloud cover/fog. Further west in
southeast Wyoming we are looking at the potential for
frontogenesis developing along and west of the I-25 corridor and
then pushing through areas east of the I-25 corridor during the
evening and overnight. This could trigger a band of snow as it
pushes through on Sunday evening. The deeper moisture and better
upper level diffluence is progged to be west of the I-25
corridor on Sunday night where they could see the potential for
accumulating snowfall with the GEFS RAW/NBM yielding to about
.3-.5 inches of QPF. Further east we are looking a bit less with
amounts generally around .1 to .2. However, we will need to
keep an eye on how this trof evolves. Currently, the models are
advertising the best cyclogenesis in eastern Colorado. If this
trends a bit further north we may be looking at more snowfall
along the I-80 corridor.
The upper level trof is progged to lift northeast and gets
absorbed into the upper level ridge by Tuesday. This should
bring an end to the snow on Monday morning with zonal flow
developing behind this trof on Tuesday. As a result, we are
looking at the potential for stronger winds on Tuesday before
our next surge of colder air moves into the Tuesday night into
Wednesday.
&&
.AVIATION /00Z TAFS THROUGH 00Z SATURDAY/...
Issued at 535 PM MDT Thu Oct 31 2024
Strong Jet Stream will remain over or near the area tonight and
Friday, which will continue to help in the development of mid to
high level cloudiness across the area. There is also a 15 percent
chance for snow showers across the southeast Wyoming terminals
tonight.
HAZARDS/WEATHER TRENDS: VFR conditions will prevail with very low
potential for low CIGS and fog. Can`t rule out a band of snow
showers developing and impacting KRWL and possibly KLAR between 03z
and 09z Friday. This may result in off and on CIGS below 2000
feet ago and IFR VIS below 2 miles at times.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...None.
NE...None.
&&
$$
UPDATE...RUBIN
SHORT TERM...GCC
LONG TERM...REC
AVIATION...MN
Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
1051 PM EDT Thu Oct 31 2024
.SYNOPSIS...
An upper ridge remains over our region until Friday, providing above
normal temperatures and continued dry weather. A cold front sags
south across our region Friday night into Saturday, bringing
slightly cooler temperatures for the weekend into early next week. A
return to well above normal temperatures appears likely in the
middle of next week ahead of the next front.
&&
.NEAR TERM /THROUGH FRIDAY/...
Key Messages...
3) A Cold Front Brings Light Rain Chances to the NC Mountains
Overnight into Friday
As of 1041 PM EDT Thursday...A quiet evening across the region, but
attention turns to the west and the approaching cold front. Made a
few alterations to the time of arrival of a band of light precip
over/along the TN border in the pre-dawn hours, and a few tweaks
to the temp trend.
Otherwise, the front will push across the western Carolinas and
northeast Georgia on Friday. Rain chances will linger across the
NC mountains through Friday so have chance PoPs in place through
early Friday evening. The 12Z HRRR shows shower activity spilling
east of the mountains but the 12Z NAMNest shows shower activity
dissipating before pushing off the mountains. If activity can
manage to hold together, a few light showers may survive east of
the mountains. However, with confidence being too low on this,
maintained dry conditions east of the NC mountains for now. Despite
the cold front, highs will remain around 10-15 degrees above climo
on Friday so it will be a warm start to November. Cloud cover
will gradually thin out Friday afternoon, especially east of the
mountains, but will likely remain in place across the mountains.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
As of 2:05 PM Thursday: The short-term forecast picks up at 00z on
Saturday with broad/flat upper ridging in place across the eastern
CONUS. Over the next couple of days, the large-scale upper pattern
will amplify as broad upper trofing digs down over the western CONUS
and the ridge amplifies over the east. At the sfc, a weak cold front
will be laying across our area as the period begins late Friday. At
the same time, broad high pressure centered over the Great Lakes will
slowly slide eastward as what`s left of the frontal boundary gradually
dissipates over our area. By the end of the period late Sunday, the
high is expected to be centered over New England as a wedge pattern
sets up over the western Carolinas. Other than a few lingering showers
possible early Saturday, the period should be dry. High temperatures
will remain well above climatology across most of the CWA on Saturday
and near to slightly above climo on Sunday. Lows will remain well above
climo both days.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
As of 2:15 PM Thursday: The extended fcst picks up at 00z on Monday
with broad upper ridging still dominating the eastern CONUS, while
a very broad/deep upper trof amplifies over the Rockies. Over the
next couple of days, the trof will gradually move up and over the
ridge and act to suppress it. Nonetheless, some degree of upper
ridging is expected to remain in place thru the middle of next
week as the period ends. At the sfc, broad high pressure will be
centered over New England with some amount of wedging over our area
as the period begins. At the same time, a sfc low will eject out of
the Rockies and lift NE towards the Great Lakes. This system is ex-
pected to eventually move a trailing cold front to our area towards
the end of the period. Most of the long-range guidance has this front
stalling-out near our western fringe as the period ends next Wed.
&&
.AVIATION /03Z FRIDAY THROUGH TUESDAY/...
At KCLT and elsewhere: VFR and fair through the end of operations
late this evening. A cold front will approach from the west
overnight. Warm advection ahead of the front and increasing clouds
should prevent the usual mtn valley fog/stratus problem. The front
gets hung up in the mtns during the middle part of the day, so a
PROB30 for showers was added to the fcst at KAVL. East of the mtns,
moisture remains available and pooled along this boundary. This
raises the possibility of a temporary MVFR ceiling restriction from
mid-morning to early afternoon, even though the model guidance
says no. The possibility should diminish by mid-afternoon as
the boundary layer deepens and lifts cloud bases into the VFR
range. The front may drift across the region late in the day,
but the fcst hardly reflects a passage with the wind remaining
from the same direction and mid/high clouds remaining overhead.
Outlook: Some restrictions may linger into Saturday morning behind
a departing cold front. Dry and quiet conditions return the rest
of this weekend into early next week as dry high pressure builds
back over 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...JPT
LONG TERM...JPT
AVIATION...PM
Area Forecast Discussion
National Weather Service Indianapolis IN
1000 PM EDT Thu Oct 31 2024
.KEY MESSAGES...
- Dry and breezy for trick-or-treating except for far southeastern
Indiana where light rain is likely.
- Cooler and dry Friday and Saturday.
- Periodic rain chances Saturday night through Tuesday night with a
warming trend.
&&
.FORECAST UPDATE...
Issued at 1000 PM EDT Thu Oct 31 2024
No significant changes required to this evening`s forecast.
The cold front, evident on radar as a fine line of reflectivity
stretching from near Winchester to Rushville and Bedford, is rapidly
progressing, and will be out of central Indiana within the next
hour. Post-frontal areas are quickly turning sharply cooler.
Have made some minor detail adjustments for timing of clearing of
the more widespread cloud deck and ending of measurable
precipitation chances. Mostly clear skies can be expected much of
the night, though some lower cloud associated with the upper low may
just skirt our northern boundary. Winds will continue to gust
occasionally, for the next hour or two, but this will gradually
subside with time overnight as well. Going lows in the mid 30s to
low 40s look fine. High temperatures on Friday will very likely fail
to reach this morning`s lows across the area, and indeed may fall 5-
10 degrees short.
&&
.SHORT TERM (This evening through Friday)...
Issued at 231 PM EDT Thu Oct 31 2024
Synopsis:
Surface analysis early this afternoon shows strong low pressure over
NW WI with an associated cold front extending south across Central
IL to SE MO and Arkansas. A moderate pressure gradient remained
across Central Indiana, with southerly flow ahead of the front.
Water vapor imagery, shows a plume of moisture streaming across
MO/IL toward Indiana, ahead of a negatively tilted upper trough over
WI/MN. Radar shows gaps developing in the rain shield that has been
arriving across Central Indiana through the day. Skies were cloudy
across Central Indiana and temperatures were falling in the 60s.
Halloween (Tonight) -
Beware! Models tonight reveal a chilling cold front sweeping across
Indiana in the witching hours from 5 PM to the end of trick or
treating. Forecast soundings show deep moisture lingering in the
shadows, rapidly drying out as eerie subsidence takes hold.
Aloft, an ominous upper trough is set to glide toward the eastern
Great Lakes, giving way to a nearly ghostly zonal flow by Friday.
The HRRR predicts that most of the spectral rainfall will creep to
SE Indiana between 8-10PM, fading into the night as it becomes
detached from the dynamic forces pulling away to the north. By 3 AM,
the pwats will drop below 0.35 inches, leaving behind a hauntingly
dry atmosphere.
A moderate pressure gradient will keep the winds howling this
evening, with gusts reaching 15-25 mph, creating an unsettling
chill. These winds will ease as high pressure rises from the plains
overnight. Prepare for strong cold air advection, with temperatures
at 850mb plummeting to a frigid 6C by dawn. Expect lows to dip into
the eerie lower 40s across much of Central Indiana. Stay cozy and
watch for ghosts and goblins in the night!
Friday -
The new month will arrive with sunny and cooler conditions. As
mentioned above, nearly zonal flow is expected aloft with little in
the way of forcing dynamics present. Meanwhile, strong high pressure
is expected to develop over the plains, strengthen and push toward
the Great Lakes. A strong mid level inversion and a very dry column
as seen on the forecast soundings will result in sunny skies with
light easterly winds. With cooler air in place, highs will only
reach the middle 50s to near 60s.
&&
.LONG TERM (Friday night through Thursday)...
Issued at 231 PM EDT Thu Oct 31 2024
The drier and cooler continental air mass will still be in place
Friday night but should begin to moderate Saturday as lower
tropospheric flow veers around to southeasterly. Temperatures should
be about five degrees above climatology. High-level Pacific moisture
and upstream cross-mountain flow should result in increasing cirrus
during the day, potentially becoming quite thick.
MSLP gradient will tighten between the eastward drifting high and
strengthening Plains cyclogenesis. This pattern will favor poleward
movement of deep subtropical moisture into Indiana Saturday night.
Warm/moist advection and weak broader isentropic ascent coupled with
a compact midlevel perturbation in southwesterly flow could result
in some precipitation Saturday night into Sunday. Multi-model
ensemble mean is sharper with the gradient on the eastern end of the
QPF maxima centered to our west, and generally has trended downward
for rainfall amounts in Indiana on Sunday. It appears the best
chance will be early in the day across the northwest half of our
forecast area, with minimal coverage the latter half of the day.
The entire synoptic trough/ridge pattern shifts slowly east Monday
placing the axis of QPF a little further east. A couple waves of
remnant convection will occur Sunday night and Monday, but timing
and amounts still need to be refined given the sensitivity of small
variations in modeling convectively-induced midlevel shortwave
perturbations and attendant precipitation footprint.
It appears the best chance of meaningful precipitation across
central Indiana will be Tuesday/Tuesday night as the Plains trough
and associated DCVA/forcing for ascent interact with the anomalous
moist plume resulting in a band of rain migrating through.
Convective intensity and potential for lightning will be limited by
the displacement of cooler midlevel temperatures closer to the
trough center to our north from the warm/moist lower troposphere
over us.
Post-frontal air mass Wednesday and Thursday will be similar to the
last couple of fronts. Drier, and near-climatology temperatures.
But, again, the southeast anomalous ridge holds and the departing
wave and associated cold continental air mass isn`t very intrusive.
The Day 8-14 period has below normal predictability. At the start,
there is quite a dipole in handling of western trough. The
deterministic GFS and a handful of its ensembles are aggressive with
eastward movement and a potentially significant precipitation event
late next week into the weekend, while the EPS and several other
multi-model ensemble members are more dominate with the ridge and a
dry pattern. So, there`s not much signal to determine if we`ll be
above or below normal precipitation, but a reasonably clear signal
on a warmer than normal pattern.
&&
.AVIATION (00Z TAF Issuance)...
Issued at 700 PM EDT Thu Oct 31 2024
Impacts:
- Sporadic gusts 17-22KT from 270-280 degrees through 02-03Z post
cold frontal passage
- Periods of MVFR ceiling through 02-03Z
Discussion:
A cold front is sweeping across the sites this evening, and winds
will rapidly become westerly where they have not already as it does
so. Sporadic gusts in the wake of the boundary will occur in the
first few hours before subsiding completely later this evening.
Additionally, occasional MVFR ceilings can be expected. Will cover
both gusts and MVFR ceilings with TEMPO groups early.
VFR conditions will return beyond 02-03Z and persist through the
remainder of the period as high pressure continues to build into the
region and skies rapidly clear. Winds will drop below 10KT overnight
into Friday, with wind directions veering to the northwest and then
northerly late in the period in response to the movement of the high.
&&
.IND WATCHES/WARNINGS/ADVISORIES...None.
&&
$$
UPDATE...Bates
SHORT TERM...Voorhees
LONG TERM...Krueger
AVIATION...Myers
AREA FORECAST DISCUSSION...UPDATED
National Weather Service Jackson KY
1002 PM EDT Thu Oct 31 2024
.KEY MESSAGES...
- Showers and isolated thunderstorms are possible this evening
into tonight with the approach of a cold front.
- Seasonable temperatures return for the weekend; near-record
breaking temperatures are possible on Tuesday.
- The next chance for widespread measurable rainfall arrives
Tuesday into Wednesday of next week.
&&
.UPDATE...
Issued at 1002 PM EDT THU OCT 31 2024
Initial line of showers, or what`s left of the line along with
associated gusty winds has just about completed its track through
the forecast area, and will be exiting to the east after getting
through another tier of counties. Winds with that initial line
were between 20 and 30 mph earlier this evening. However, any
precipitation associated with the initial line as well as the
winds have dissipated or weakened considerably. Another band of
light, to at times moderate rain, will continue to move across the
area through the rest of the evening and overnight. Forecast has
all of this handled well. Updated hourly grids top bring them in
line with surface observations. Otherwise, freshened up the zones
to remove evening references. Updated forecast products have been
issued.
UPDATE Issued at 645 PM EDT THU OCT 31 2024
Initial line of showers is just entering our forecast area this
evening, tracking west to east and has held together a little
better than earlier runs of the hrrr suggested. Based on current
trends in shower activity and regional radar, increased PoPs
across our western zones through the evening. Still dampened
activity as it moves eastward through our eastern zones during the
evening, but with a resurgance in activity after midnight over
those areas further east. Overall it would appear everyone should
see some rainfall accumulations, though exact totals are still
uncertain, but would seem to be generally between a tenth or so
and around a third of an inch, possibly up to a half inch for
locations along and west of I-75. In general the inherited
forecast had this covered well, with main changes to the forecast
being made within the first few hours of the evening period to
better capture most recent trends. Updated zones and grids have
been issued.
&&
.SHORT TERM...(This evening through Friday night)
Issued at 318 PM EDT THU OCT 31 2024
Current surface analysis is rather busy across the entire CONUS. The
most important feature is a surface low situated over Wisconsin.
From this low, a stationary boundary is extended eastward across the
St. Lawrence Seaway. Also, a cold front is extending southwest from
the low all the way down to the Texas Gulf Coast. Locally, increased
cloud cover ahead of the cold front is building into the area with
breezy southwesterly winds around 20 to 25 mph. Also, due to
southwesterly flow, temperatures are climbing into the upper-70s to
low-80s across eastern Kentucky. At the JKL Weather Office, the
previous high temperature record for today has been broken. These
record breaking high temperatures will continue to exist over the
area today before that aforementioned cold front brings increasing
rain chances this evening and overnight.
The approaching cold front is currently moving into far western
Kentucky at this moment but gusty showers are slowly working across
central Kentucky. Over the next few hours, those showers will
increase in coverage and move into the JKL CWA. Along with these
showers, isolated thunderstorms are possible but mainly along and
west of the I-75 corridor. While some instability exists in these
locations, severe weather isn`t expected. Showers will continue to
be possible through the overnight hours as the front quickly moves
through the area. Showers will begin to dissipate from northwest to
southeast through Friday morning before the front exits Friday
afternoon. Post-frontal high pressure will build back into the area
ushering near-seasonal, albeit still slightly above average
temperatures, back into the area for the remainder of the forecast
period.
.LONG TERM...(Saturday through Thursday)
Issued at 423 PM EDT THU OCT 31 2024
The 31/12z model suite is in good agreement to start the forecast
period on Saturday morning. An elongated ~589dam ridge extends
from the Gulf of Mexico northeastward to over Bermuda, resulting
in a quasi-zonal pattern over the Ohio Valley initially. At the
surface, there is an quasi-stationary frontal boundary over the
Tennessee Valley through Lower Mississippi Valley and then
northwestward into the Central High Plains. High pressure resides
north of this front over the Great Lakes. Looking upstream, a
trough extends from British Columbia southward through the West
Coast states to offshore the Baja California Peninsula.
During the first 48 hours of the forecast period, the upper level
trough will cross the Rockies and deepen while the downstream ridge
will amplify northward toward the Hudson Bay. As the surface,
high pressure shifts to over the Northeast and deep southerly
flow develops between the eastern upper level ridge and western
upper level trough. This will send the surface front surging back
at a warm front on Sunday, ushering in a very mild (12-14C at
850mb) and moist air mass (PWATs approaching or exceeding the 90th
percentile relative to climatology) over eastern Kentucky. The
upper level trough begins to dampen later Monday and Tuesday as it
tries to pivot eastward toward the Ohio Valley. The associated
surface cold front associated with the trough will initially race
through the Plains but then slow and hang up near/over the Ohio
Valley mid-week. Model solutions become increasingly divergent on
the weather pattern at this point as additional energy from the
North Pacific drops in the the trough and renews a deep trough or
closed low over the Central or Western CONUS. Depending upon how
the pattern unfolds, the stalled front could drop southeast of
the area, remain stalled nearby, or lift back north of the area
on Wednesday or Thursday.
In sensible terms, expect a drier day on Saturday amidst weak
northeasterly flow on the southern side of the Great Lakes high
pressure. Temperatures are expected to run slightly above normal
for early November with highs ranging from the mid 60s north of
the Mountain Parkway to the middle 70s in the upper portions of
the Cumberland River valley (e.g Middlesboro and Harlan). One of
or perhaps even the "coolest" night of the period follows Saturday
night with lows forecast to range from near 40 in the northern
hollows to the lower 50s near the Tennessee border and on thermal
belt ridges. Clouds increase later Saturday night and peak on
Sunday/Sunday evening as warm front lift through the area.
Isolated showers are possible with the front, best chances toward
the Bluegrass. Forecast highs range in the lower to upper 70s,
north to south, on Sunday. Very mild temperatures--highs in the
70s to near 80 and lows in the 50s to lower 60s--are expected on
Monday and Tuesday with partly to mostly cloudy skies. The next
substantial rain chances arrive on Tuesday with the next cold
front but the duration and QPF remains lower confidence due to
model spread. Temperatures are likely to cool closer to normal for
mid-week but specific details are uncertain.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
ISSUED AT 755 PM EDT THU OCT 31 2024
Showers and predominant MVFR flight conditions expected through
the overnight period, then improve through the day Friday. A
surface cold front approaches the area, with widespread, but
scattered showers ahead of the front. An initial line of shower
activity has entered eastern Kentucky and will continue to push
eastward, though with some dissipation of activity expected as it
progresses eastward. However, as the surface front enters into the
area during the overnight, additional showers will redevelop,
impacting all of our terminals during the night. CIGS will
gradually drop as the front enters and passes through the region.
FROPA is expected at KSYM around 08Z, KSME, KLOZ, and KJKL around
09Z, and KSJS around 10Z. Winds will be southerly, 5-10 kts with
some gusty winds up to 25 kts with the initial line of showers.
Winds shift out of the west for about an hour after the initial
line of showers, then turn southerly until the surface front
passes through the area during the early morning hours. Northwest
winds between 5-10 kts are expected immediately behind the surface
front before going variable at 5kts or less through the late
afternoon.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...RAY
SHORT TERM...VORST
LONG TERM...GEERTSON
AVIATION...RAY
Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
634 PM CDT Thu Oct 31 2024
.KEY MESSAGES...
- Snow gradually departs east through late afternoon. The
forecast appears to be dry for Trick or Treat across most of
Minnesota, however light snow may linger into the evening
across western Wisconsin.
- Areas of dense fog possible tonight where a surface snowpack
remains.
- Warmer (upper 50s/low 60s) temperatures will return this
weekend as the unsettled pattern continues with widespread
rain chances through early next week.
&&
.DISCUSSION...
Issued at 242 PM CDT Thu Oct 31 2024
~1002mb surface low has meandered east into western Wisconsin early
this afternoon. Radar captures the ongoing deformation band of snow
across eastern Minnesota and surface observations indicate that the
transition to snow is ongoing across western Wisconsin. Further
west, radar captures a decrease in coverage of light echoes
owing to drier air moving in. Snowfall intensity will gradually
decline over the next few hours as the low pivots further east,
though it seems plausible another inch or so of slushy accumulation
may occur under the heaviest band. The strong northwest winds
will begin to decrease from west to east as the low drifts out
of the picture and the pressure gradient begins to relax in
time. It looks like most of southern Minnesota will be good to
go for Trick or Treat, with perhaps a few lingering snowflakes
here and there. Our PoPs remain higher in western Wisconsin due
to the slow eastward movement of the low. Temperatures will
likely be the greatest concern for those out and about this
evening. Air temperatures in the low to mid 30s are expected
areawide, however the combination of cold air and gusty winds
will drop wind chills into the 20s across eastern Minnesota and
western Wisconsin. Bundle up with an extra layer or two if trick
or treating!
Skies will clear tonight and winds are expected to become light and
variable as high pressure builds in. Latest RAP forecast soundings
advertise a dense fog setup across central Minnesota, where the
majority of today`s snowpack will likely remain overnight. Warm
advection will increase by Friday afternoon, as a swift moving
wave slides across the Upper Midwest during the afternoon and
evening. Afternoon highs are forecast to range from the low 40s
in western Wisconsin to the low 50s in western Minnesota given
the expected warm advection out of the central Great Plains. A
surface low associated with the ripple aloft is progged to move
across west central Minnesota and may produce scattered showers
Friday evening into early Saturday. A dry period is expected
through the daytime hours as a thermal ridge builds over the
Upper Midwest. Highs are forecast to warm well into the 50s
Saturday and Sunday afternoon, amid the broad warm advection
regime.
The warming trend will be accompanied by the return of widespread
rain chances as early as late Saturday, but more likely into the day
on Sunday. Guidance depicts a deep trough across the Rockies Sunday
morning, with a of fetch of mid-level flow extending from the Gulf
to the Upper Midwest. PWATs are forecast to climb above 1" by Sunday
afternoon, which is well above the 90th percentile for November
sounding climatology. Broad isentropic ascent and anomalous moisture
return will likely produce widespread, beneficial rain across the
region Sunday into Monday. The longwave trough is forecast to slide
east into early next week, with a secondary surface low progged to
lift northeast into the Upper Midwest/Great Lakes region. Guidance
is in poor agreement with the track of the secondary surface low,
such that very wet and nearly dry solutions are in place across the
ensemble suite Monday into Tuesday. For now it appears that Sunday
into Monday is an areawide soaking rainfall, where as Monday into
Tuesday may be focused south and east across eastern MN/western WI
where NBM PoPS are near 80%. Ensemble means continue to advertise
the potential for up to 2" of rainfall through the multi-day period,
but that will be dependent on the track of the secondary low.
Quiet weather rounds out the forecast period with highs in the
low 50s and dry conditions for the middle to end of next week.
&&
.AVIATION /00Z TAFS THROUGH 00Z FRIDAY/...
Issued at 609 PM CDT Thu Oct 31 2024
Precip is slowly winding down this evening and should be done at
all terminals by 3z. Cigs are becoming VFR pretty quick as
precip ends, though the LAV and RAP forecast soundings show the
status could linger for several hours at EAU. We`ve seen a
general trend away from there being much in the way of fog
tonight as mid level clouds will be sluggish to clear, so kept
any fog mention out of the 00z TAFs. Fog can`t be ruled out, but
confidence in it occurring is too low to include in the TAFs.
The fog potential is actually looking better for Friday night.
Friday, we`ll start with mostly clear skies, but we will see
mid-level clouds increase from the west in the afternoon as a
batch of showers moves toward central MN.
KMSP...VFR cigs will move in quickly this evening, with VFR
conditions remaining through the rest of the period
/OUTLOOK FOR KMSP/
SAT...VFR. Wind S 5-10 kts.
SUN...MVFR/-RA likely. Wind SE 10-15 kts.
MON...MVFR/-RA likely. Wind SE 10-15 kts becoming W.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...None.
WI...None.
&&
$$
DISCUSSION...Strus
AVIATION...MPG
Area Forecast Discussion
National Weather Service Marquette MI
808 PM EDT Thu Oct 31 2024
.KEY MESSAGES...
- Winter Weather Advisory for Gogebic County this afternoon and
evening for wet snow accumulations of 1-4 inches.
- Rainfall transitions to snow this afternoon through tonight.
Widespread wet snow accumulations could create some slippery
conditions impacting the evening commute and trick-or-treating
hours.
- Blustery winds gusting up to 25-35 mph today. Potential (40-60%)
for gusts up to 40 mph near Lake Superior and in the interior
central/east.
- Mostly dry Friday and Saturday, but wet pattern returns
Sunday and next week.
&&
.SHORT TERM /THROUGH TONIGHT/...
Issued at 131 PM EDT Thu Oct 31 2024
Radar returns indicate numerous to widespread showers overspreading
much of the UP today. With the prior cold front now well to the
south and east, these showers are forced by a surface low that the
RAP analysis indicates is near 1002 mb in the La Crosse, WI
vicinity. Cool northerly flow is already keeping temperatures around
40 degrees this morning with some interior west and Keweenaw
Peninsula locations already approaching the mid-30s. Cool air aloft
filtering in has already begun to introduce some wintry precip
types, with various mPING reports in Houghton County of ice pellets
and wintry mix and webcams near Ironwood already showing snowfall.
Precip rates so far have not been particularly strong, with MRMS
estimates of hourly precip rates mainly at a tenth of an inch per
hour or less except for some isolated spots in Ontonagon County
which briefly saw quarter inch per hour rates earlier this morning.
The compression of the pressure gradient ahead of this low is also
forcing some gusty surface winds today, with KSAW already reporting
gusts of 30 kt as well as the Munising and Copper Harbor ASOS sites.
Expect the wind to continue today, with gusts up to 35 kt possible
(~50%) along the lakeshores and in the interior central and east
where the low will make its closest pass.
The main forecast question is going to be snow totals. There is some
uncertainty in the sticking ability of whatever does fall as soil
temperatures in the east half of the UP are still in the mid 50s,
though not much data is available in the west half of the UP where
the bulk of the wintry precip is expected. Road temperatures have
fallen faster than initially expected, with a road temperatures
sensor near Ironwood already at 40 degrees after being in the
mid to upper 40s last night. From the standpoint of the
atmosphere, snow rates in the west will be supported by good
lift in a DGZ that is between 2-4kft for a few hours this
afternoon and early evening out west. Should SLRs be around 10:1
(likely will be less given surface temps near freezing), the
12Z HREF suggests 30-50% chances that the west half high terrain
will see 1 inch per hour snowfall rates by this early evening.
Ultimately, little change in the current headlines are expected
as the highest snow totals are expected still in the Ironwood
area (justifying the WW.Y) and in the highest terrain of
Marquette and Baraga counties where impacts will be much less as
there`s few roads and even fewer people (justifying the SPS).
By 05Z tonight, synoptic precipitation will end as the low moves off
to the east. 850mb temperatures falling to near -7 C over Lake
Superior that is at around 10 C. This will support some lake effect
snow, though only light snow and only over the east half. The
spatial limitation is due to the ridging approaching from the west
already creating unfavorable conditions for snowband development by
tonight, though cyclonic flow is still present in the east half. The
NBM50th percentile comes in a few degrees lower than its
deterministic counterpart, though the general pattern of the
deterministic NBM showing above freezing temps at the shores down to
the mid 20s in the interior is favored.
&&
.LONG TERM /FRIDAY THROUGH THURSDAY/...
Issued at 336 PM EDT Thu Oct 31 2024
The active weather pattern continues through the extended period,
although we do start out dry with some ridging as we move into this
weekend. As the last of the lake-effect precipitation ends over the
east half Friday morning, high pressure ridging builds in to cut-off
the lake-effect and bring sunnier skies over us Friday, although
some of the lake-effect clouds may stubbornly hold over the central
and east until the late afternoon/early evening hours as antecedent
cold air remains aloft in the lower levels. Thus, even with the
sunnier skies, expect the highs Friday to be near to slightly below
normal, only getting into the lower to mid 40s across Upper
Michigan. As warm air advection moves over us Friday night into
Saturday via a shortwave lifting from the Northern Plains towards
Thunder Bay, we do have around a 10% chance of seeing some light
rain showers over the far west late tonight into Saturday. In
addition, we could see some light lake-enhanced light rain/drizzle
showers off of Lake Michigan over the southeast U.P throughout the
day Saturday as the warm air advection occurs (also around a 10%
chance). However, rainfall across the rest of the U.P. may have a
difficult time occurring as the dry air associated with the ridging
looks to stubbornly hold on in the lowest levels of the atmosphere;
with the better forcing over the Arrowhead of Minnesota, expect the
area to remain mostly dry Friday night into Saturday. Nevertheless,
the warm air advection will help to increase temperatures from
around normal to above normal by Saturday into early next week.
Precipitation looks to return in the form of rainfall Sunday as a
shortwave centered around a low pressure in the Plains rotates
northward into Upper Michigan. As warm frontogenesis moves through,
we could see some moderate to heavy rain showers at times as light
rainfall generally moves across the entire area. However, there is a
chance that the heavier rain chances miss us, as some models like
the GFS keep the better rainfall amounts to the east of us (the GFS
keeps most of the area almost completely dry). With this in mind,
expect the highest rainfall amounts in the east, and the least in
the west.
Even if we do miss out on good rainfall Sunday, expect additional
rain showers and maybe a rumble of thunder or two early next week as
the low pressure lifts into the Upper Midwest and brings its warm
front and cold front overtop us. We could see a much-needed soaking
rainfall over the U.P., especially the east where the LREF has up to
a 40% chance of seeing 1 inch or greater of liquid precipitation.
Given the anomalously warm air in the warm sector of the low, we
could see record high minimum temperatures, and maybe near record
maximum temperatures too to a lesser extent given the cloud cover
expected. Once the cold front passes through by the middle of next
week, a cessation of the rainfall is expected until late in the
forecast period as temperatures cool back closer to normal.
&&
.AVIATION /00Z TAFS THROUGH 00Z SATURDAY/...
Issued at 735 PM EDT Thu Oct 31 2024
A low pressure system over eastern Upper Mi is responsible for
the -SHRA to -SHSN over the terminals this evening. Gusty
northerly winds to 30 knots are also impacting CMX and SAW this
evening.
At IWD and CMX, Expect IFR conditions in -shsn to improve to
MVFR and then VFR by midnight or shortly thereafter as ridging
from the west ends the snow and disperses the low clouds as
20-30 kt winds lighten.
With SAW, cold air is slower to work in behind the system so the
transition from -shra to -shsn won`t occur until late evening or
closer to midnight. Being closest to the low pressure, north winds
will stay gustier longer with gusts to 30 knots through the
evening. Expect IFR conditions to improve to MVFR closer to 08Z
and then to VFR after sunrise Friday.
&&
.MARINE...
Issued at 336 PM EDT Thu Oct 31 2024
Northeasterly gales to 35 knots this afternoon shift to the north to
40 knots this evening over the east half before dying down to 20
knots or less Friday morning as ridging moves in (some gales up to
45 knots are possible over the east half this evening). Thus the
waves will increase from 8 to 11 feet this afternoon to 9 to 14 feet
over the east half this evening before decreasing to 4 feet or less
Friday afternoon. The light winds continue Friday into this weekend
as a shortwave passes through the Arrowhead Friday night/Saturday
and another shortwave rotates into the region Sunday evening. This
second shortwave, in conjunction with the warm front of a low
approaching from the Plains, is expected to increase winds from the
southeast to 20 to 30 knots, with a few gale force gusts up to 35
knots possible over the eastern lake (5% chance according to the
NBM). As the warm front continues pushing into Ontario, expect the
winds to become more southerly and to die down to 20 knots or less.
However, once the cold front of the low moves through around next
Tuesday, expect winds to shift to the northwest and gust up to 20 to
30 knots across the lake. Additional shortwaves behind the cold
front could keep the stronger winds going across Lake Superior as we
move towards the latter half of next week.
Outside of the winds some rumbles of thunder could be heard Monday
and Tuesday early next week as the warm and cold fronts move through.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
Winter Weather Advisory until 10 PM CDT this evening for
MIZ009.
Lake Superior...
Gale Warning until 11 PM EDT /10 PM CDT/ this evening for
LSZ240>242-263.
Gale Warning until 2 AM EDT Friday for LSZ243-244-264.
Gale Warning until 5 AM EDT Friday for LSZ245-248>251-265>267.
Lake Michigan...
Gale Warning from 11 PM this evening to 5 AM EDT Friday for
LMZ221-248-250.
&&
$$
SHORT TERM...GS
LONG TERM...TAP
AVIATION...Voss
MARINE...TAP
Area Forecast Discussion
National Weather Service Phoenix AZ
405 PM MST Thu Oct 31 2024
.UPDATE...
Updated Aviation section.
&&
.SYNOPSIS...
Dry and quiet weather conditions will continue into the start of
the weekend with temperatures near or slightly below normal.
Another weather system will move in during the later half of the
weekend bringing below normal temperatures and a chance of showers
to the region.
&&
.DISCUSSION...
Visible satellite imagery this afternoon shows mostly clear skies
over the region as zonal flow prevails. RAP analysis early this
afternoon showed that 500 mb heights have risen to around 576-578
dm with current temperatures generally running around 2-5 degrees
warmer in many areas compared to 24 hours ago. As dry, tranquil
conditions persist through the next couple of days under a quasi-
zonal flow, temperatures will be closer to near to slightly below
seasonal normals. High temperatures through Saturday across the
lower deserts will top out in the upper 70s to low 80s and mid to
upper 70s for higher terrain locations such as Globe, San Carlos,
and Tonto Basin. Dry conditions will persist into the start of
the weekend before a more unsettled weather pattern prevails later
in the weekend.
While quiet weather persists locally, the latest satellite WV
imagery shows troughing in place over the Pacific Northwest.
Guidance show this trough, along with a couple pieces of energy
currently near the Aleutian Islands, digging into the Desert
Southwest this weekend. Ensemble cluster analysis show much better
agreement amongst ensemble members compared to prior iterations,
with guidance now showing greater certainty that a progressive
trough will propagate through the region. This solution does
unfortunately favor lesser rainfall potential with the progressive,
inland trajectory limiting moisture and rainfall chances. Latest
guidance suggest a weaker cold front will push into our area late
Saturday into early Sunday with moisture along/ahead of the front
boosting PWAT anomalies upwards of 125-150% of normal. However,
forecast soundings show a less favorable profile for better rain
chances with moisture briefly increasing throughout the mid and
upper levels. Thus, NBM PoPs have begun to trend down from
previous runs. Opted to further trim down PoPs across the area
from the NBM as NBM PoPs are still too high. If trends continue,
we will continue to see a downward trend in PoPs for Sunday. WPC
QPF has also greatly come down as a drier solution becomes
increasingly favored amongst global ensembles. Latest WPC QPF is
now down to less than 0.10" across the lower deserts of south-
central Arizona and up to 0.25-0.50" across the southern Gila
County high terrain.
Outside of rain chances, temperatures will once again fall to below
normal readings as forecast highs drop into the low to mid 70s
starting Sunday. Morning low temperatures may also once again cool
into the 40s for some of the colder lower desert locales and 30s for
places like Globe and San Carlos early next week. This weather
system is also expected to bring an increase in winds, particularly
to parts of southeast California and along the Lower Colorado River
Valley for the start of next week. Uncertainty once again increases
going into the latter part of next week as ensembles suggest another
low pressure system will dig down into the southwest CONUS with one
solution showing an open wave trough while another solution shows a
closed/cutoff low developing. Still pretty far out at this point so
stay tuned as these details become better resolved.
&&
.AVIATION...Updated at 2305Z.
South Central Arizona including KPHX, KIWA, KSDL, and KDVT; and
Southeast California/Southwest Arizona including KIPL and KBLH:
The approach and passage of a weak upper level disturbance will
lead to some passing high clouds tonight and Friday but otherwise
have little discernible impact. Surface winds will remain light
(AOB 7kts) and generally follow familiar diurnal directional
patterns. For the Greater Phoenix area, that will mean westerly
components favored until 03Z before trending toward
downvalley/drainage patterns (favoring easterly component) by 06Z
followed by slow development of SW/Wly winds in the afternoon.
&&
.FIRE WEATHER...
Temperatures will be near to slightly below normal through
Saturday and fall back below normal by the beginning of next week.
Minimum afternoon humidity levels will be in the 10-25% range
today and tomorrow across the region and on Saturday for the
central and eastern districts. Fair to good overnight recovery
close to 30-60% continue through Saturday morning, with good to
excellent overnight recoveries of 60-80% Saturday night. Winds
will tend to follow their typical diurnal tendencies and be on the
lighter side with minimal afternoon upslope gusts. Highest
afternoon wind gusts are expected on Saturday afternoon with gusts
of 15-25 mph possible. Chances for wetting rainfall increase on
Sunday as another weather system moves into the region.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...None.
CA...None.
&&
$$
DISCUSSION...Smith
AVIATION...AJ
FIRE WEATHER...Berislavich
Area Forecast Discussion
National Weather Service Raleigh NC
855 PM EDT Thu Oct 31 2024
.SYNOPSIS...
Unseasonably warm, Bermuda high pressure will extend across the
Carolinas until a cold front moves through the region Friday night.
Mild high pressure will follow and build across the middle Atlantic
through the weekend.
&&
.NEAR TERM /THROUGH TONIGHT/...
As of 855 PM Thursday...
...Near Record Warm Tonight...
Southerly flow around the periphery of the offshore Bermuda high
pressure will support near record warmth tonight. A few
rural/outlying areas may cool down into the upper 50s, but temps
overnight at most locations should remain in the lower 60s, which
will challenge record hi-min temps at RDU and GSO climate sites.
Similarly to last night, the southern/central coastal plain and
sandhills are showing the best indicators for fog, potentially
dense. Otherwise, skies will vary from mostly clear to partly cloudy
as some lingering WAA stratocu persists across the area. Then
towards sunrise, western/northwestern portions of the forecast area
should see an increase in mid/high clouds, owing to the approach of
a cold front into the mtns.
&&
.SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/...
As of 255 PM Thursday...
A surface low will be over Quebec Friday morning with a cold front
extending southwest along the western side of the Appalachian
Mountains. Over the following 24 hours, the low will move over the
northern Atlantic Ocean, with the cold front crossing central North
Carolina during the late afternoon and evening hours. The European
ensemble has been the wet outlier for several days, but the latest
run keeps most precipitation to the north of US-64 Friday night.
Deterministic and ensemble guidance continues to disagree in the
precipitation potential. Several high-resolution models included in
the 12Z HREF do show potential for showers, although it still
appears that any rain that does occur will be light in nature. Will
continue with a slight chance of rain for most locations in the
forecast area, using a blend of the 12Z HRRR and the 06Z/12Z runs of
the Nam Nest for timing the spread of precipitation. Highs will be
very warm once again, although still below record values, ranging
from the mid 70s to the mid 80s. The cold air behind the front will
not arrive immediately, so Friday night`s lows won`t be too
different from tonight`s lows. Along the Virginia border, lows will
fall into the 50s; elsewhere, lows will still be in the lower 60s.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
As of 400 PM Thursday...
Zonal flow aloft on Saturday will gradually transition to a more
amplified flow with strong mid-level ridging over the Southeast US
and Mid-Atlantic by Monday and Tuesday. At the surface, high
pressure centered over the Lower Great Lakes on Saturday will shift
east into New England on Sunday. As the high ridges down the Eastern
Seaboard, NE flow will keep temperatures much cooler than previous
days this weekend but still slightly above normal. Highs from
Saturday through Monday will be in the mid-60s to mid-70s with lows
in the mid-40s to mid-50s. There will be some cloud cover around,
but no precipitation is expected.
The surface high will shift east into the Atlantic and Monday and
Tuesday, shifting the low-level flow to a SE direction especially by
Tuesday when there may be enough moisture and upslope flow to
generate some patchy light rain in western NC. A minority of GEFS
and EPS ensemble members extend this rain into our western Piedmont,
so carry slight chance POPs there on Tuesday and Tuesday night. Any
amounts would be light given the ridging in place aloft.
Temperatures will also increase with highs in the mid-70s to lower-
80s and lows only in the lower-60s.
As the ridging shifts east and offshore on Wednesday and Thursday, a
cold front may start to approach from the NW, so carry slight chance
POPs on Wednesday and slight to low chance on Thursday. However,
there are significant differences on the overall pattern between the
ECMWF and GFS, with the GFS lifting the front back north while the
ECMWF brings it through late Thursday. The GFS also indicates
potential for tropical development off the Southeast US coast, but
it is way too far out for any confidence at this time. Temperatures
will remain well above normal until the cold frontal passage.
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
As of 805 PM Thursday...
24 hour TAF period: Fairly confident VFR conditions will prevail
through at least 06Z and probably through 09Z most places, with just
some scattered clouds around 5 kft. Fog/low stratus is most likely
to develop at KFAY (where winds and sky cover are expected to be
lowest), between 09Z and 13Z Fri, and is possible at KRWI and maybe
KRDU, though confidence is much lower at the latter two terminals
given uncertainty regarding cloud cover and stirring. Where low
stratus does develop, it may take several hours to lift/scatter out
Fri morning. VFR conditions should return by Fri afternoon and
prevail through the end of the TAF period. The other aviation
concern is the potential for borderline LLWS conditions at the
northern 4 terminals (all but KFAY) between 05Z and 10Z Fri. For
now, the surface winds are expected to stay in the 5-8 kt range
during that time, which would keep the terminals below LLWS criteria
given the 30-35 kt LLJ. However, should the winds drop at any of
those terminals, LLWS criteria could be met. Winds could be a bit
breezy/gusty during the day Fri, especially across the north. -KC
Outlook: Nely flow, behind a backdoor cold front that will move
through the region Fri night, will favor low VFR or MVFR ceilings
Sat morning, lowest at KINT/KGSO. There could also be some light
rain late Fri night and Sat. The nely flow will persist through Sun
night, with a deck of (at least) low-end VFR cigs expected again Sun
and Mon mornings. The surface winds will veer around to more sely
Mon and Tue as another cold front approaches from the west. -KC/MWS
&&
.CLIMATE...
Record High Temperatures:
October 31:
KRDU: 85/2019
KFAY: 88/1933
November 1:
KFAY: 87/1961
November 5:
KFAY: 86/2003
November 6:
KGSO: 80/1975
KRDU: 83/2022
KFAY: 85/2022
Record High Minimum Temperatures:
November 1:
KRDU: 63/1919
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SYNOPSIS...MWS
NEAR TERM...CBL
SHORT TERM...Green
LONG TERM...Danco
AVIATION...KC/MWS
CLIMATE...RAH