Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 11/09/20
Area Forecast Discussion...UPDATED
National Weather Service Amarillo TX
553 PM CST Sun Nov 8 2020
.UPDATE...
Seeing just enough H7 moisture influx to generate showers across
the area ahead of weak S/WV. Might be just enough instability to
generate an isolated TSTM as well. Increased POPs this evening
to 20-25% in central areas where best chances for measurable rain
are expected. Could make an argument for higher increase based on
HRRR and may need to make additional updates.
&&
.AVIATION...
SHRA and possibly a TSTM will impact central portions of the
Panhandle as a disturbance moves across the area. AMA has best
chance of seeing this activity as it lies in the middle of the
narrow moisture/instability axis. This activity will be somewhat
light and high based. Minimal impacts to CIGs is expected and
cloud bases should remain above MVFR levels, however did include a
TEMPO with minimal impacts in AMA TAF during evening hours for
TSTMs. Some MVFR visibility is possible in stronger cells, but chc
of this happening at terminal is low. MVFR stratus CIGs are
expected to mainly stay east of AMA to GUY for the early morning
hours on Monday and VFR conditions will develop across entire
region by late morning.
&&
.PREV DISCUSSION... /Issued 234 PM CST Sun Nov 8 2020/
SHORT TERM...Tonight through Monday Night...
Strong south to southwest flow will continue today and tomorrow over
the Panhandles. Breezy to windy conditions will continue through the
evening and into Monday as the system stays stalled over the Four
Corners area. Dewpoints have been kicking up under this south
southeast surface flow across the central and eastern Panhandles so
much that a Pseudo-dryline is expected to setup. Although it
doesn`t appear that we will see much of any showers or storms, the
is about a 10 percent chance that something could pop this afternoon
and evening. A pacific front is expected to move through mid
afternoon tomorrow with low RH values and breezy westerly winds.
Thunderstorms out ahead of the front will be possible, but it looks
like the front will be through to early and the storm development is
expected east of the Panhandles. A cold front is then progged to
enter the Panhandles from the north tomorrow night, bringing near
freezing temperatures to the southern Panhandles and below freezing
temperatures to the northern Panhandles by Tuesday morning. Cold
front is expected to be dry. It looks like the winds will relax by
Tuesday morning, and therefore the wind chill should not be too bad.
Weber
FIRE WEATHER...Today and Monday...
RFTI`s in the 2-4 range all driven by wind will continue today
across the western Panhandles. While ERC`s are in the 60+
percentile in the northwest, the rest of the western Panhandles is
below the 50th percentile, and therefore will only be elevated. Any
fires that occur on Monday and continue to burn into the late
evening, will be subject to a north wind shift with the cold front.
Otherwise winds out of the west 25-30 mph with some gusts up to 40
mph possible.
Weber
LONG TERM (Tuesday through Saturday)...
Overall, the long term is pretty quiet outside of a small chance
for rain and perhaps some thunderstorms Friday/Friday night.
Otherwise, highs in the 50s and 60s are expected with plenty of
sunshine through next weekend. Could see some clouds Friday with
those rain chances, and this day also looks to be our breeziest
day of the long term with sustained speeds around 15-25 mph.
In the upper levels, a Rex block is evident off the east
coast/Gulf of Mexico, while broad long wave troughing is evident
over much of the CONUS. The Rex block will slow the progression
of the trough eastward, with nearly all the embedded energy within
this trough staying north of the forecast area. So, not expecting
much if anything in the form of precipitation for the Panhandles
until we transition out of this pattern. Looks like the blocking
pattern breaks down Thursday and we begin to transition to a more
zonal flow over the Panhandles, and by Friday our first shortwave
trough looks to pass over the forecast area. Unfortunately for us,
the available moisture looks better east and south of our area,
so this only puts us in about a 20 percent chance for rain across
the eastern Texas Panhandle. Our CAPE values are not looking as
good as they did in the previous forecast. That said, with a few
hundred J/kg of MUCAPE we could get a thunderstorm or two to form
if any showers materialize. Another feature to watch will be an
upper level jet streak (300mb) around 110-125 knots which could
provide an additional source for lift. All in all, our chances for
rainfall appear slim at this time.
Guerrero
&&
.AMA Watches/Warnings/Advisories...
TX...None.
OK...Red Flag Warning until 6 PM CST this evening for the following
zones: Cimarron.
&&
$$
88/88
Area Forecast Discussion
National Weather Service Cheyenne WY
710 PM MST Sun Nov 8 2020
.UPDATE...
Issued at 702 PM MST Sun Nov 8 2020
...Light to occasionally moderate snow tonight for the eastern
plains...
Current forecast for tonight and early Monday looks on track, with
KCYS radar loop showing some midlevel snowfall developing along
and just east of the I-25 corridor. Expect this trend to continue
over the next few hours as the upper level trough near the four
corners region slides eastward. A strengthening upper level 135
knot jet will be located across the eastern plains tonight, with
impressive difluence aloft shown through noon Monday. For now,
kept the 1 to 2 inches of snow along and east of the I-25
corridor. However, we expect some locations to see as much as 3-5
inches in the heavier bands of snow. Low confidence in the
placement of these heavier snow bands, so will hold off on Winter
Weather Advisories for now. Did note some really low dewpoint
temperatures at the surface this evening, so the snow may take a
while to reach the ground.
&&
.SHORT TERM...(Tonight - Tuesday)
Issued at 232 PM MST Sun Nov 8 2020
Snow chances are expected to increase significantly this evening &
overnight as a deep upper-level low continues to spin over much of
the western CONUS. A more substantial piece of mid-level energy is
expected to eject northeast from the 4 Corners region after around
06z, impacting the high plains of southeast WY and western NE thru
18z Monday. There is growing concern that a band of heavy snow may
develop from near Cheyenne northeastward through Chadron overnight
tonight through early Monday. This area will be in the favored LFQ
of an intense/140 knot H25 jet, well-placed beneath persistent low
level frontogenesis. A broad area of negative saturated EPVS would
indicate the presence of instability and resultant locally heavier
snowfall rates. Ensemble plumes do not support significant amounts
of snow, but trends in the HRRR have been toward heavier, and more
widespread precipitation overnight. Confidence in a swath of snow-
fall amounts of 1-2 inches (locally 2+) is growing, so this is the
main change to the inherited forecast for tonight. Advisories will
hopefully not be needed, but this will be something to watch.
Snow showers will persist through much of the day on Monday w/ the
potential for light accumulations mainly west of the Laramie Range
and in the mountains. In general, expect an inch or two in the low
elevations with 3-6 inches in the mountains through late afternoon
on Monday. The focus will shift toward high winds Monday night and
Tuesday as another short wave sweeps east across the northern high
plains. The resulting pressure falls will increase 700/850 mb CAG-
CPR gradients into the 60-70 meter range along with 55-65 knots of
700-800 mb flow over the wind prone areas. We have gone ahead with
a High Wind Watch for 03z Tuesday through 06z Wednesday.
.LONG TERM...(Wednesday - Sunday)
Issued at 257 AM MST Sun Nov 8 2020
Generally cool to mild conditions across the CWA this period with
several shortwaves passing across in a progressive pattern. One
looks to scoot across late Weds with the next ones late Friday
and late Saturday. Not much in the way of pcpn with these outside
of the higher mtns where periods of snow showers are expected.
Temperatures fairly close to seasonal averages along with periods
of gusty winds with the passing of these systems.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 430 PM MST Sun Nov 8 2020
VFR conditions expected to persist for next 6 hours as a mid-level
energy coupled with frontogenic forcing will contribute to an
overnight increase in snow and MVFR to IFR conditions for majority
of terminals. Have trended TAFs a bit to LAMP guidance coupled
with lower visibility and CIGS in periods of expected snowfall.
CIGS will remain low through at least 18z with expectation that
forcing aloft will keep conditions low through much of the
daylight hours Monday.
&&
.FIRE WEATHER...
Issued at 257 AM MST Sun Nov 8 2020
Elevated fire weather conditions linger yet another day across the
western Nebraska Panhandle`s I-80 corridor with only a short
window of opportunity to receive light precipitation this morning
as a strong cold front passes through the region. This front is
currently situated just west of the Laramie Range, and has been
associated with strong and gusty winds. These winds will continue
to effect the region with High Wind Warnings in place for the
wind-prone areas of southeast Wyoming and most of the Nebraska
Panhandle. Quick, light shots of moisture will remain for most of
the week, though the mountains look to receive the most
precipitation. The windy pattern will remain as well. Minimum
humidities drop into the 20s again at the end of the week.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...High Wind Watch from Monday evening through Tuesday evening for
WYZ106-110-116-117.
NE...None.
&&
$$
UPDATE...TJT
SHORT TERM...CLH
LONG TERM...RE
AVIATION...WM
FIRE WEATHER...AB
Area Forecast Discussion
National Weather Service Quad Cities IA IL
256 PM CST Sun Nov 8 2020
.SYNOPSIS...
Issued at 130 PM CST Sun Nov 8 2020
Beautiful near-record warm conditions continue across the CWA
today. Temperatures are once again already in the 70s as of 1 pm
area wide. Dewpoints have climbed into the upper 50s/low 60s and
with temperatures nearing the convective temp, scattered Cu has
started to develop. Gusty south winds between 20-25 mph have also
been observed.
&&
.SHORT TERM...(This Evening through Monday)
ISSUED AT 230 PM CST Sun Nov 8 2020
Forecast focus in the near term is on temperature and cloud
trends.
This Evening-Tonight...high temperatures should fall just shy of
record highs for the date. Models have struggled today in terms of
cloud cover and temperatures, with bulk of guidance showing more
widespread clouds and thus lower temps. The 15z HRRR was the first
model to have a good handle on temps and used as a guide with
highs today. Winds will subside after sunset this evening, but
remain above 10kts. Stronger WAA aloft, higher dewpoints, and
more cloud cover, will keep temperatures in the low 60s
overnight. The 12z HRRR ensemble has higher probabilities of cloud
cover west of a FFL to DBQ line tonight, which may see warmer
readings than further east. Record warm lows will be possible for
Nov 9th and are listed in the climate section below.
Monday...another pleasant early November day is forecast with near
record temperatures and breezy south winds. A great day for any
activities outside. Pressure gradient will increase between a
surface low moving east over Nebraska and large high over the
eastern CONUS bringing strong southerly winds, gusting between
25-35 mph in the afternoon. Cloud trends and depth of mixing will
be the main factors as to how warm we get. Went with the 75th
percentile of all guidance for highs and still may be too cold.
Current forecast has temperatures within 1-2 degrees from record
highs. All 12z models and most hi-res solutions have now backed
off on developing light showers ahead of cold front during the day
and I have removed slight chances from forecast after
collaboration with neighboring offices. The better moisture and
forcing signal remain to our west until Monday night and Tuesday.
.LONG TERM...(Monday Night through Sunday)
ISSUED AT 230 PM CST Sun Nov 8 2020
Key Messages:
1) Strong cold front Tuesday with rain, thunder and wind
2) Colder /near normal/ temperatures mid to late week.
Forecast details:
Monday night
Breezy and continued unseasonably mild, with near record/record warm
lows for much of the area well into the 50s to lower 60s. The
exception potentially being some of our far northwest counties, or
areas roughly west of a Manchester to Marengo line where a cold
front could begin to make inroads late at night settling
temperatures into the 40s post-frontal. A lot of uncertainty though
to the progression of the front, as a wave of low pressure is
suggested to develop associated with an approaching vigorous mid
level shortwave. This will look to assist increasing rain chances
mainly west of the Mississippi River.
Tuesday and Tuesday night
Lifting mid level wave and attendant surface low rippling along the
cold front will provide more persistent and widespread rain across
our west/northwest areas on Tuesday. PWATs are shown to increase to
around 1.3 inches supportive of swaths of 1-2 inch rain potential.
The precipitation is likely to transition to more linear band(s) of
showers and embedded storms along and especially east of the
Mississippi River ahead of mid level dry slot and cold front. These
will bring brief bouts of heavy rain with overall amounts a bit
lower and generally 0.25 to 0.75 inch. Shear profiles remain fairly
impressive for nearly mid November, but instability is rather
weak. Nonetheless, will have to continue to monitor the late
morning until mid afternoon period ahead of dry slot for an
isolated severe threat /mainly wind/ with SBCAPEs progged 300-600
j/kg. Especially monitoring for any steepening of lapse rates and
potential pockets of solar insolation which could foster increased
threat of mixing down severe gusts to surface. In addition, will
have to keep a close eye on extent of the low level frontal
circulation, which could aid in backing low level winds resulting
in some brief tornado potential as well pending extent of BL
destabilization. Dry slot should rapidly shut down precipitation
in the afternoon from SW to NE. Winds ahead of the cold front on
Tuesday could be near advisory criteria at times along/east of the
Mississippi River near nose of strong low level jet. Most areas
are expected to see highs occur in the morning through midday
before falling after the frontal passage. Brisk west winds are
possible for a time Tuesday evening post-frontal in the wake of
the departing low. These winds will continue to usher in colder
air, with lows falling into the upper 20s to lower 30s.
Precipitation looks to be pulling away and any wrap-around staying
mainly north before colder air works in to create any change-over
concerns.
Wednesday through Friday
Colder /more seasonable/ temperatures look to persist through late
week. Continuing to see some signal in the late Thursday into early
Friday timeframe for a light mixed precipitation event. Confidence
however is very low, as models struggling namely with the
placement/magnitude of surface high pressure. Aloft, there`s good
agreement on a trough migrating across the Upper Midwest. Questions
revolve more around track of vort max and main upper forcing, and
location of the surface high pressure and attendant low level
reservoir of dry air. As mentioned, should we see any precipitation
it is expected to be light.
Next weekend
Signal continues to trend toward potentially another active period
sometime of the weekend, as additional Pacific energy shifts
eastward into the central CONUS. Considerable differences exist in
the medium range guidance in the track/timing of the energy although
starting to see a north/west trend, and if this continues would
expect another rain event. Strong jet and baroclinicity would
support potentially a fairly dynamic system, with possibly a severe
storm and wintry side so will be needing to watch this closely to
see how it evolves.
&&
.AVIATION...(For the 18Z TAFS through 18Z Monday Afternoon)
ISSUED AT 1117 AM CST Sun Nov 8 2020
VFR conditions to continue through this evening with gusty south
winds dissipating after sunset. With winds likely remaining above
10kts through the overnight hours, kept LLWS mention out of TAFs
for now. Clouds are expected to increase in eastern IA overnight,
with MVFR cigs possible. Southerly winds will again increase near
the end of TAF period, ahead of approaching system from the west.
&&
.CLIMATE...
ISSUED AT 230 PM CST Sun Nov 8 2020
Record Warm Lows for November 9...
Moline.........58 in 1931
Dubuque........53 in 1999
Record Highs for November 9...
Moline.........77 in 1999
Cedar Rapids...76 in 1999
Dubuque........74 in 1999
Burlington.....76 in 1999
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
SYNOPSIS...Gross
SHORT TERM...Gross
LONG TERM...McClure
AVIATION...Gross
CLIMATE...Gross
Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
952 PM EST Sun Nov 8 2020
.SYNOPSIS...
Warm and dry high pressure will become centered off the New
Jersey coast on Monday and remain there through Tuesday. Meanwhile,
a cold front will slowly approach from the west, while Tropical
Cyclone Eta tracks near southern Florida and into the Gulf of
Mexico. The front will slowly cross the forecast area Wednesday
through early Friday, keeping the weather unsettled.
&&
.NEAR TERM /THROUGH MONDAY/...
At 940 pm EST: Another very slight uptick in overnight mins
was warranted on the latest update, with obs running just a bit
warmer than forecast trends, and clouds poised to thicken and lower
beneath the subsidence inversion in the moist easterly flow. The
near-term models are very conservative on overnight precipitation,
but a few weak radar returns are already indicated in a few spots in
the mountains, and the RAP features slightly better sfc to 850 mb
moisture and upslope flow into the eastern escarpment from 06Z to
09Z. Isolated light rain showers will be featured in the upslope
areas through the early morning hours.
Otherwise, the overall synoptic pattern will not change much over
the near term period, with vertically stacked high pressure slowly
transitioning farther SE off the mid-Atl coast. Another round of
improving moisture flux in the onshore flow will permit low end
isolated to scattered PoPs to rebound once again late Monday in the
eastern escarpment upslope areas. Any precipitation amounts will be
quite light. Max temps Mon will be similar to Sunday, or perhaps a
touch less in cloudier areas, with readings in the low to mid 70s
east of the mtns and upper 60s in the mtn valleys.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/...
As of 155 pm Sunday: A high amplitude/non-progressive pattern will
persist through the short term, with deep anticyclone expected to
remain centered off the southeast coast, and broad/strong trough
over the West. Resultant deep SE flow will allow tropical moisture
plume/atmospheric river north and east of T.C. Eta to begin
streaming over the forecast area Tuesday and remain through the end
of the period. Pops will address increasingly moist SE upslope flow
with a gradual uptick and expansion from Tue morning through Tue
night, with 70-90 probabilities advertised across the entire area by
sunrise Wed. By and large, precip amounts should be manageable from
a hydrology perspective through at least Wed morning, as lifting
mechanism will generally be limited to upslope effects, although at
least locally heavy rainfall will be possible within a narrow axis
along the southern Blue Ridge escarpment.
This may change later Wed into Wed night, as frontal zone associated
with the first in a series of short wave troughs lifting out of the
Desert Southwest moves into the region. This will act as an
additional source of focused lift of a tropical air mass. That being
the case, the most likely time for a localized excessive rainfall
threat will be late Wed into Wed night, with additional heavy
rainfall potential coming from an increasing risk of thunderstorms,
as short term guidance is in good agreement in advecting at least
modest levels of instability Wed afternoon. By sunrise Thursday,
storm total amounts of 1.5 to 2.5 inches are expected to be
widespread across the area, with higher amounts quite likely along
the southern Blue Ridge as well as other areas of training tropical
showers. Max temps will remain a few degrees above climo, and min
temps well above normal, in fact jeopardizing maximum low temp
records, esp Tue night and Wed night.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
As of 220 pm Sunday: Confidence remains below normal in the medium
range, although the situation is gradually coming into better focus
for next weekend. Highly amplified pattern will persist through the
period, albeit with the western Atlantic anticyclone expected to
steadily weaken as a series of short wave troughs ejecting from the
western Conus result in increasing occurrence of height falls across
the East. In general, global models agree in allowing drier air to
build into the area in the wake of the cold front late in the week,
although at least small pops are retained into the weekend in light
of increasing uncertainty. Of course, the elephant in the room is
the eventual fate of TC Eta, and guidance generally continues to
exhibit very little consensus and poor run-to-run consistency in
this realm, but we will certainly not be out of the woods in terms
of another round of heavy rainfall late in the week, especially as
another frontal zone appears likely to impact the area in the day
6/7 time frame. Temps will generally remain above climo normal, but
generally returning closer to normal levels by the weekend.
&&
.AVIATION /03Z MONDAY THROUGH FRIDAY/...
At KCLT and elsewhere: Increasing low-level moisture advection from
the east overnight will combine with a persistent inversion in
profiles around 5 kft feet to allow cigs to thicken and lower
through the nighttime hours. With slightly better mixing forecast
than on earlier Sunday model runs, bases could be a tad higher
overnight, with mainly MVFR for a good portion of the nighttime
hours and the daytime hours on Monday, but with a 4 to 6 hour period
of IFR cigs possible around daybreak at all sites. The main
exception could be KAND, where the easterly flow moisture may not
pool as quickly and IFR could be avoided. Otherwise, expect
gradually increasing NE flow, SE at KAVL, with low end gusts with
mixing onset on Monday. A return to VFR cigs is likely at most
locations through the afternoon hours, and any showers worth
mentioning will hold off until Monday night at KCLT.
Outlook: Warm and moist flow at low-levels off the Atlantic will
continue to produce ceiling restrictions Monday night through
Friday, with the deepest moisture likely on Wednesday. Periods of
MVFR to IFR cigs can be expected, especially once a slow moving
front moves in from the west and greatly increases the chances of
rain mid week.
Confidence Table...
03-09Z 09-15Z 15-21Z 21-00Z
KCLT High 100% High 86% High 88% High 84%
KGSP High 100% High 88% High 86% Med 77%
KAVL Med 71% Med 68% High 80% High 86%
KHKY High 93% Med 75% Med 76% High 82%
KGMU High 96% High 81% High 86% Med 77%
KAND High 98% High 88% High 88% Med 75%
The percentage reflects the number of guidance members agreeing
with the scheduled TAF issuance flight rule category. Complete hourly
experimental aviation forecast consistency tables are available at
the following link:
www.weather.gov/gsp/aviation
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...None.
NC...None.
SC...None.
&&
$$
SYNOPSIS...DEO
NEAR TERM...HG/SBK
SHORT TERM...JDL
LONG TERM...JDL
AVIATION...HG