Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 10/29/21
Area Forecast Discussion
National Weather Service Charleston SC
1023 PM EDT Thu Oct 28 2021
.SYNOPSIS...
A low pressure system will impact the region through tomorrow.
High pressure will return on Sunday and prevail through the
middle of next week.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
The last of the heavier and steadier rains will pull north of
the Santee River by midnight with the passage of the triple
point. There can still be a few showers through the overnight in
various places due to the approach of the mid and upper level
low, but coverage will be sparse.
There has been enough clearing and a significant drop off in
winds where we have patchy fog through 12-1 am. Locally dense
fog is possible but not enough for a Dense Fog Advisory. Drier
air will steadily advance into the area from the southwest, and
as winds aloft align themselves more with surface winds and some
cool advection develops, there is also more mixing as surface
winds increase again.
Depending upon the strength of the cool advection and the amount
of clearing, min temps are a challenge. We will go with a blend
of the NBM, HRRR, RAP and MOS, arriving at a large range from
lower 50s across far interior Georgia, to the mid and upper 50s
most elsewhere, except 60-64F along the barrier islands and
across most of Charleston County.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/...
An impressive deep surface low extending into the upper levels over
the Tennessee Valley will slowly track northeast through the period,
eventually transitioning into a open wave over the New England
region Sunday. The forecast area remains in a somewhat dry slot
Friday and Saturday with much of the moisture/rain focused to our
west over the SC/GA Midlands as well as offshore to our east.
Isolated showers could breach the extreme inland counties and the
coastline, mainly in the afternoon hours Friday and Saturday. Thus,
POPs feature values between 10-15% across these areas. Sunday will
remain precip-free as dry surface high pressure builds in from the
west.
High temperatures Friday will range in the mid 60s inland to
low 70s along the immediate coast. Saturday will be a couple of
degrees cooler before warming on Sunday into the low 70s with nearly
full sunshine across the forecast area. The forecast features low
temps in the upper 40s most places and low to mid 50s along the
coast.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
High pressure will remain the dominant surface feature through much
of the period. Drier air and a lack of any notable forcing
mechanisms will support a rain-free forecast each day. A weak cold
front associated with an upper disturbance could approach the region
around the middle of next week. For now, guidance shows the greatest
moisture north of the region, which could maintain the dry forecast
into next weekend. High temperatures are expected to be near normal
with slightly above-normal min temps.
&&
.AVIATION /02Z FRIDAY THROUGH TUESDAY/...
The remains a risk for MVFR conditions either in light fog
and/or lower ceilings early tonight, and again briefly in any
isolated -SHRA/SHRA that might occur in association with an
approaching upper level low through Friday. Otherwise, mainly
VFR will prevail.
We have low level wind shear at all three sites early tonight
now that surface winds have calmed down, but strong winds remain
in the lower levels.
Winds are expected to increase again overnight or early Friday,
and continue through most of the remainder of the 00Z TAF cycle.
This is the combination of a tight gradient, rising pressures
and a higher mixing height.
Extended Aviation Outlook: VFR conditions are expected through
the middle of next week.
&&
.MARINE...
Overnight: The last remaining Gale Warning for AMZ350 will come
down at midnight, as the gradient has finally eased enough and
mixing is tempered somewhat by neutral or slight warm advection.
The other waters have improved enough where we have Small Craft
Advisories in effect, and once the Gale comes down, it will also
join the other waters with a Small Craft Advisory.
Late in the overnight period there is another surge as cool
advection develops and isallobaric pressure rises coincide with
a tightening of the gradient. This could result in a marginal
Gale Warning.
Seas that have been elevated will be very slow in coming down,
dropping only about a foot or so through the night.
Friday through Tuesday: Elevated winds and seas will persist on
Friday with Small Craft Advisories (SCAs) continuing across all
marine zones. We have extended the SCA for the Charleston Harbor
through Friday evening for gusts up to 25 kt. Conditions are
expected to improve Friday night as winds and seas decrease, with
SCAs over the Beaufort/Colleton County waters and GA waters out
20nm, and the Charleston Harbor coming down Friday night. The
remaining SCAs are expected to come down by Saturday morning, though
winds will likely remain in the 15-20 kt range through the day. No
marine concerns early next week as high pressure expands over the
region.
Rip currents: Gusty winds and longer period swell (11-12 seconds)
will lead to an elevated risk of rip currents Friday and Saturday. A
Moderate risk of rip currents is forecast for both days.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...None.
SC...None.
MARINE...Small Craft Advisory until 8 PM EDT Friday for AMZ330-352.
Small Craft Advisory until 8 AM EDT Saturday for AMZ350.
Gale Warning until midnight EDT tonight for AMZ350.
Small Craft Advisory until 8 AM EDT Saturday for AMZ374.
Small Craft Advisory until 8 PM EDT Friday for AMZ354.
&&
$$
NEAR TERM...
SHORT TERM...BRM
LONG TERM...BRM
AVIATION...
MARINE...
Area Forecast Discussion
National Weather Service Grand Forks ND
1058 PM CDT Thu Oct 28 2021
.UPDATE...
Issued at 1055 PM CDT Thu Oct 28 2021
The main concern for the overnight period will be potential and
timing of fog set up. Mist developed across the northern valley
for about two hours, however enough mixing with the NW winds
helped it erode with this last set of obs. Stratus ahead of a
Warroad to Sabin MN line will continue to move east leaving
clearing skies in its wake. As the surface ridge slides east,
winds will continue to decrease and enhance radiational cooling.
Models continue to target mainly NW MN (east of the valley) for
fog development by around 07Z. Have adjusted Wx grids for a bit
more fog coverage tonight, and will need to monitor for potential
headlines closer toward morning.
&&
.SHORT TERM...(This evening through Friday night)
Issued at 234 PM CDT Thu Oct 28 2021
Minimal impacts in the short term with high pressure ridge axis
traversing the area tonight. That said there is the possibility of
another night or morning of some fog impacts across portion of
NW MN as light winds and clear skies allow for radiational fog
development. Given the clouds today, recent rainfall and
saturated blyr persisting will add the fog mention from late
tonight through the morning commute Friday along the eastern edge
of the RR valley and into lakes country for portions of MN.
Tomorrow will see increasing mixing from west to east during the
day as southerly flow develops in response to developing low
pressure over the high plains. This mixing will bring highs to
near 60 in the west to low 50s east. Friday night will be the last
night above freezing with the southerly winds persisting and temps
holding in the upper 30s.
.LONG TERM...(Saturday through Thursday)
Issued at 234 PM CDT Thu Oct 28 2021
Principal chances for impactful weather really aren`t presenting too
much as we head into a tranquil a cooler weather period to begin
November.
Sat offers best pcpn chances as a wave/sfc cold front moves from DVL
early in the day to WC MN by late aftn/eve. Winds will shift to the
W and NW and become breezy behind the feature, but little if any
pcpn is likely along with it.
Flow will be generally NW from this point on, bringing dry and
cooler weather to the forecast area. To wit : 850 mb temps dipping
below freezing more consistently yielding overnight lows well down
in the 20s with corresponding afternoon maxima limited to the 30s.
&&
.AVIATION...(For the 06Z TAFS through 06Z Friday night)
Issued at 1055 PM CDT Thu Oct 28 2021
The back edge of the stratus has cleared TVF and should be through
BJI by midnight (05Z), definitely by the time the 06Z TAFs go into
effect. So think all sites will start off VFR (possible exception
of MVFR vsbys at TVF), with TVF/BJI seeing vsbys drop rapidly
somewhere in the 08Z to 10Z timeframe. Expect IFR cigs for early
morning flights as FG develops. Models area a bit slow
dissipating FG tomorrow morning, so late morning is possible and
will lean towards worse case as no strong confidence of a rapid
burnoff after sunrise.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...None.
MN...None.
$$
UPDATE...Speicher
SHORT TERM...JK
LONG TERM...WJB
AVIATION...Speicher
Area Forecast Discussion
National Weather Service Sacramento CA
231 PM PDT Thu Oct 28 2021
.SYNOPSIS...
Dry and mild weather through Friday. A weather system moving over
the far northern portion of California will bring a chance of
showers late Friday and Saturday, mainly to the northern mountains
and northern Sacramento Valley. Rain returns to the majority of
Northern California early next week.
&&
.DISCUSSION...
Fog and low stratus continued to build north into the northern
San Joaquin Valley and Sacramento Valley this morning, as far
north as the Sacramento metro area, and slowly dissipated through
the morning hours. The fog/stratus kept temperatures dampened in
the mid 60s through early afternoon in affected areas, whereas
temperatures in the far northern Sacramento Valley rose quickly to
the 70s. However, temperatures are bouncing back as high pressure
remains situated over California. Valley temperatures are
forecast to top out in the low 70s to near 80s across the Valley
today and tomorrow with 50s to 60s in the mountains and
foothills. HREF and HRRR guidance suggest patchy fog is possible
once again tomorrow morning in the Valley, mainly near and south
of the Sacramento area.
Ensemble guidance remains on track with a tight, closed upper low
approaching the forecast area tomorrow, bringing precipitation
chances late tomorrow night into Saturday. Guidance continues to
slow the weather system, and members are becoming more in
agreement on the timing. Precipitation chances are limited to the
Coastal Range, northern Sacramento Valley, Southern Cascades, and
adjacent foothills as the southern edge of the low brushes through
the forecast area. This system is looking a little more convective
in nature, with a chance of isolated thunderstorms on Saturday.
QPF amounts have increased slightly due to the convective nature
of this system. Precipitation amounts of 0.1 to 0.6 inch are
forecast, with the heaviest amounts expected in Shasta County.
Ensemble guidance has the upper low moving out of the forecast
area by Sunday as another longwave trough approaches the West
Coast, bringing dry weather to interior Northern California for
Halloween. Temperatures will cool to around 5 to 10 degrees below
normal Saturday and Sunday with Valley temperatures in the 60s and
mountains and foothills in the 40s to low 60s. -HEC
&&
.EXTENDED DISCUSSION (Monday THROUGH Thursday)...
Unsettled weather is forecast to continue through the extended
period as ensemble guidance shows longwave troughing continuing in
the Eastern Pacific through next week. Guidance is in good
agreement of a deeper wave brushing across northern California on
Monday. IVT forecast indicates it will tap into some tropical
moisture, bringing more widespread precipitation across the
forecast area. However, the front is expected to weaken as it
makes landfall as the main trough only brushes the forecast area,
so QPF amounts will be more limited than if the trough fully hit
the forecast area. Precipitation amounts in the Valley are only
around 0.1 to 0.3 inch with 0.25 to 1 inch in the mountains and
foothills, mainly north of Highway 50. This will be a warm system
with snow levels above 7,500 to 8,000 feet.
Weak ridging takes over on Tuesday, then ensemble guidance
indicates another upper trough approaching the coast Wednesday.
Timing and strength is still uncertain at this point, but guidance
brings in another round of precipitation in the
Wednesday/Thursday timeframe with this system. Temperatures
through the week will remain below normal with Valley in the 60s
and 40s to 60s in the mountains and foothills. -HEC
&&
.AVIATION...
VFR conditions next 24 hours expect local MVFR/IFR possible in
BR/FG from KCIC southward between 06z-18z Friday. Surface winds
remain under 12 knots.
&&
.STO WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
Area Forecast Discussion
National Weather Service Topeka KS
909 PM CDT Thu Oct 28 2021
.UPDATE...
Issued at 909 PM CDT Thu Oct 28 2021
Cancelled the Wind Advisory. Winds continue to diminish this
evening and have fallen below advisory criteria. Sustained winds
around 20 mph with gusts around 30 mph will remain possible
through the overnight hours.
&&
.DISCUSSION...
Issued at 244 PM CDT Thu Oct 28 2021
19Z water vapor imagery and profiler data show a closed upper low
over central MO slowly lifting north. The surface low with this
system was centered over southwestern MO. The strong pressure
gradient associated with the low pressure system has caused north
winds to gust between 30 and 50 MPH pretty consistently across the
forecast area today. Further west water vapor imagery showed
shortwave ridging over the southwestern U.S. extending up into the
northern Rockies. Another upper trough was noted off the west coast
of North America.
Models are in good agreement with the overall slow progression of
the low pressure system just west of the forecast area. This keeps
the upper level deformation and deeper moisture over far eastern KS
for much of the night. So the light rain and overcast skies are
forecast to continue through a good portion of the night. There
could be some light rain over eastern parts of Anderson and Franklin
counties through the mid morning hours Friday. The other sensible
weather will be the continued gusty winds through the night. The RAP
and HRRR want to keep wind gusts around 45 MPH into the evening,
high enough that I`ve considered extending the wind advisory. Would
like to say the pressure gradient relaxes a little overnight, but
the RAP and NAM both maintain the pressure gradient near the current
strength. And the RAP and HRRR show stronger wind gusts expanding in
area overnight. So will go ahead and extend the advisory through
tonight for the eastern two thirds of the forecast area where the
RAP/HRRR show the stronger gusts persisting.
Shortwave ridging is expected to move over the area by Saturday with
clear skies. This looks to create good conditions for radiational
cooling Saturday morning as winds at the surface become light and
variable. Because of this have inserted areas and widespread frost
across much of the forecast area with lows likely in the lower to
middle 30s. Will probably need a frost advisory and freezing warning
for parts of the area Saturday morning. Temps should warm somewhat
Saturday afternoon as southerly winds bring some warmer air north
ahead of the next cold front Saturday night. There isn`t much
moisture or forcing for the front to produce any precip. Increasing
cold air advection for Sunday is expected to keep highs in the lower
and middle 50s.
The next chance fore precip looks to come Monday as models hint at
some mid level frontogenesis moving in from the northwest as a weak
PV anomaly passes overhead. Mid levels look to saturate enough for
some light precip. Temps in the lower troposphere look to remain
warm enough for precip to mainly be in the form of rain, but temps
aloft look cold enough that there could be some wet snowflakes mix
in early in the morning. Northerly winds and limited insolation are
likely to keep temps in the 30s and 40s for Monday. There may be a
break in precip Tuesday before another shortwave passes aloft
Tuesday night. There are indications for moisture to possibly be
lifted back north of the surface front Tuesday night. However the
surface front is progged to be in central OK and that seems like a
long way for moisture to make it this far north. Because of this
there are only some small POPs (20 to 30 percent) across east
central KS. Both the ECMWF and GFS take the surface front well south
of the forecast area by Tuesday and keep it south through the end of
the forecast period. So confidence in the chances for precip after
Monday evening are low thinking moisture would be pretty limited
this far north into the surface ridge. Northerly winds through the
middle of next week are likely to keep temperatures below normal. In
fact areas across northern KS could see a hard freeze next week.
With the local growing season considered to be over after October
31, I don`t anticipate the need for frost or freeze headlines next
week with the colder temperatures.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 620 PM CDT Thu Oct 28 2021
VFR at KMHK through the TAF period with gusty north winds through
tomorrow morning. MVFR at KTOP/KFOE with gusty north winds
through tomorrow morning. VFR at KTOP/KFOE thereafter. Rain will
diminish this evening from west to east and finally move out of
the area by tomorrow morning.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Jones
DISCUSSION...Wolters
AVIATION...Jones
Area Forecast Discussion
National Weather Service Tulsa OK
1015 PM CDT Thu Oct 28 2021
.DISCUSSION...
Have allowed all wind advisories to expire, as most gusts have
fallen below 40 miles an hour. Every now and then, an isolated 40+
mile an hour gust appears, but they have been few and far between
since the sun has set.
Scattered to numerous showers continue to move south across
northeast Oklahoma and northwest Arkansas, mainly to the east of
Highway 75, and the latest HRRR says this trend will continue for
much of the rest of the night. Have expanded low pops west a bit
in the 06-12Z period to account for this.
The clearing line has moved little this afternoon and evening, and
have raised cloud cover overnight in most places. Also raised
overnight lows a couple degrees.
Update has already been sent.
&&
.PREV DISCUSSION... /Issued 649 PM CDT Thu Oct 28 2021/
AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM/KROG.
Northwest Arkansas TAF Sites...IFR/MVFR conditions along with
scattered rain showers and breezy/gusty winds will remain common
tonight and into Friday as the backside of the upper low continues
push off to the east. During the afternoon hours
Friday...conditions look to be more MVFR to low end VFR through
the end of the period.
Eastern Oklahoma TAF Sites...some scattered rain showers maybe
possible into the overnight period otherwise broken VFR conditions
and breezy/gusty winds are forecast. Late tonight into Friday
morning there could be a period of MVFR conditions and will carry
tempo groups for Northeast Oklahoma. During the day
Friday...conditions are expected to lift back to VFR by mid/late
morning with cloud cover scattering out during the afternoon hours
behind the exiting upper low.
PREV DISCUSSION... /Issued 157 PM CDT Thu Oct 28 2021/
DISCUSSION...
Gusty conditions persist this afternoon as strong northwesterly
winds wrap around the vertically-stacked cyclone currently across
southwestern MO. Have observed frequent gusts around 40-45 mph
across parts of eastern OK, with an occasional 50+ mph gust
(highest so far in our area has been a 53 mph gust at the Foraker
mesonet site in Osage county). Thicker cloud cover farther east
has limited the mixing and kept winds a bit in check, but still
seeing gusts of 35-40 mph for the bulk of eastern OK/northwest
AR. Wind Advisory products are scheduled to expire at 00Z for
eastern OK and 03Z for northwest AR. It`s possible these will need
to be extended and will defer this decision to the evening shift.
Otherwise, areas of mostly light showers will linger through the
night, with precipitation tapering off across northwest AR on
Friday.
Milder weather is forecast for the weekend as mid-level heights
rise in the wake of the exiting cyclone. Halloween weather is
looking great, with highs in the 60s/lower 70s and temperatures
falling into the upper 40s/mid 50s during the evening.
The initial wind shift associated with the next front will sag
through the area on Sunday, with deepening cooler air expected to
hold off until early next week. Rain chances could arrive as early
as late Monday, with the better chances expected later Tuesday
into Wednesday as a stronger wave zips across the region in the
southern stream. Temperatures are expected to remain below
normal, with highs generally in the 50s and lows in the 30s/40s.
Could see our first light freeze late in the week for parts of
northeast OK and northwest AR.
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...None.
AR...None.
&&
$$
SHORT TERM...20
LONG TERM....05
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