Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 10/08/18
Area Forecast Discussion
National Weather Service La Crosse WI
638 PM CDT Sun Oct 7 2018
.SHORT TERM...(This evening through Monday)
Issued at 329 PM CDT Sun Oct 7 2018
At 3 PM, showers over central Wisconsin were just exiting the
area. Meanwhile, another shortwave trough was producing another
area of showers across western and southern Iowa. The CAMs are
trying to dissipate much of this rain before reaching our area.
They did a similar thing with the showers that moved through the
area this morning. Considering the increasing 925 mb and 850 mb
moisture transport that shows up in all of the models tonight,
just do not see the dissipating trend verifying, so went with a
faster trend in increasing the rain chances late this afternoon
and evening.
The RAP like many of the other models do not increase the most
unstable CAPES until after midnight tonight. As a result,
restricted the thunderstorms chances until after midnight.
Rainfall totals for tonight will range from a half to 1.5 inches.
On Monday, the models are in agreement that the warm front will
gradually move northward during the day. Since it will be moving,
this will like reduce the risk of flooding. Additional rainfall
totals will be up to three quarters of an inch. The highest
amounts will likely be across north-central Iowa, southeast
Minnesota, and north of Interstate 90 in Wisconsin which is
further north and northwest than tonight.
.LONG TERM...(Monday night through Sunday)
Issued at 329 PM CDT Sun Oct 7 2018
On Monday night, many of the models have a low pressure system
moving along the quasi-stationary front extending central Iowa
northeast toward western Upper Michigan. This will enhance the
convergence along the front. With precipitable water values around
1.8 inches and warm cloud depths around 3.5 km, the showers and
storms will be efficient rain producers. In addition the front
will be focus for training storms. Additional rainfall totals will
likely range from 1 to 3 inches. Due to this, WPC has put this
area in a moderate risk of excessive rain. Considered issuing a
Flood Watch for this time period, but due to some uncertainty on
the location of this front held off for now.
From Tuesday into Wednesday, the models continue to differ on the
timing of the eastward progress of this front. Due to this, there
is uncertainty on where the heavy rain axis will occur and how
wide it may be. If it is faster, the rain amounts will be lower
and the swath of heavier rain axis will be wider. If it is slower,
the axis will be narrower and the rainfall amounts will have to be
increased. Due to this uncertainty, WPC has a wider moderate risk
of excessive rain.
From Tuesday night into Wednesday morning, the models continue to
differ on the strength of negatively tilted trough moving through
the region. Like the past couple of the days, the GFS remains
weaker than the GEM and ECMWF. This means it has far less shear
than the others. SPC has a Slight Risk of severe weather for the
area, so we will have to watch this period closely.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 638 PM CDT Sun Oct 7 2018
Conditions expected to deteriorate through the overnight hours,
with widespread LIFR ceilings eventually expected later tonight
into Monday morning as moisture advances into the area ahead of a
warm front slowly lifting north through the area. We will also see
periods of showers/rain and some drizzle mixed in as well, with a
round of dense fog also possible at RST later tonight into Monday
morning as cloud heights lower toward the ground. Gradual
improvement is expected at both locations later on Monday,
especially by afternoon, with LSE standing the best chance to see
ceilings lift to MVFR levels (maybe even briefly VFR by late
afternoon) while RST sits in IFR much of the day.
&&
.HYDROLOGY...
Issued at 329 PM CDT Sun Oct 7 2018
Periodic showers and a few thunderstorms can be expected across much
of the forecast area through Wednesday. With precipitable water
values in the 1.5 to 2 inch range across much of the region...the
showers and thunderstorms will be efficient rain producers.
Rainfall amounts of 3 to 4 inches are expected...with locally
higher amounts possible. The combination of current forecast
rainfall amounts and antecedent soil conditions...will cause
higher water levels and rises on area rivers...streams and creeks.
River flooding is expected through the middle of this week.
Please see the latest river statements for river forecasts.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
IA...None.
&&
$$
SHORT TERM...Boyne
LONG TERM...Boyne
AVIATION...Lawrence
HYDROLOGY...DTJ
Area Forecast Discussion
National Weather Service Caribou ME
1026 PM EDT Sun Oct 7 2018
.SYNOPSIS...
High pressure will build across the region tonight and then
move into the Canadian Maritimes on Monday. A warm front will
cross the region later Monday night into Tuesday with the same
front crossing back through the region as a back door cold front
Tuesday night and Wednesday.
&&
.NEAR TERM /THROUGH MONDAY/...
1030 PM Update...Satl imagery showed clouds thinning out across
the northern 3rd of the CWA, while clouds were holding from
KHUL on south. The interior Downeast region was starting to fill
in w/a nnw flow. The 01z RAP was doing well w/its depiction of
the cloud scheme as it showed some clouds filling in across the
Downeast to the coast while northern areas thin out. Decided to
follow this trend and keep clouds around the eastern and coastal
areas through 4-5 AM. This in turn will keep overnight temps up
while areas starting to clear such as to the n, will allow for
temps to drop. Tweaked the overnight lows to keep warmer temps
Downeast. Otherwise, the current forecast looks in good shape.
Previous Discussion...
Persistent stratocumulus cloud field across northern Maine as
of late this afternoon is starting to give way to some breaks
across portions of the central highlands and downeast Maine.
Across the far north, very little in the way of breaks in the
clouds, although one doesn`t have to go too far north to find
some breaks across the Gaspe Peninsula and northern New
Brunswick. Near term guidance, as can be typical this time of
year, not doing a very good job handling the sky cover.
As the center of the Canadian high pressure system across
Quebec continues to build east overnight, think we will
eventually see partial clearing, even across the north. The
temperature forecast will ultimately depend on how quickly skies
clear tonight, have gone with a general model blend for lows
tonight. Thus, expect mid 20s to lower 30s north and upper 30s
to lower 40s downeast.
High pressure will settle across the region early Monday and
then move east into the Canadian Maritimes by afternoon. After
a mainly sunny start, we will begin to see increasing afternoon
clouds, as warm front begins to approach from the southwest.
Any showers; however, will tend to hold until after sunset on
Monday. Highs on monday will range from the low 50s north and
mid to upper 50s central and downeast.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
Clds will be on the increase Mon eve with rn/shwrs ahead
of a warm front front late Mon ngt into Tue morn, mainly for Nrn and
Cntrl ptns of the Rgn with max rnfl totals of a quarter inch
plus across the far N where we went with categorical PoPs.
Almost all of the longer range models bring the warm front about
as far N as the St John vly by Tue aftn which should lift the
rn/shwr zone just N of our FA by this tm. A zonal s/wv topping
the upper ridge from Nrn Ont thru Cntrl QB will result in the
front slowly dropping back SSW thru our FA Tue ngt into Wed as
a back door cold front with low cldnss, lgt rn and dz. Temps
will b e challenging durg this ptn of the fcst, spcly hi temps
Tue, but in general well abv avg temps spcly Cntrl and Downeast
areas Tue will cool for Tue ngt and spcly Wed.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
More general rnfl ahead of low pres and a cold/cold occlusion
frontal system from the upper great lks will begin to move into
the Rgn late Wed ngt and cont thru Thu with the most enhanced
rnfl rates just ahead of the front mid to late Thu aftn where we
again went with categorical PoPs. behind to cold front, drier
conditions are anticipated for ovrngt Thu into Fri with NNW sfc
wind likely resulting in stubborn SC cld cvr ovr spcly Nrn ptns
of the FA with near seasonal temps. Otherwise, follow-up weak
s/wvs associated with re-enforcements of cooler air will keep
cld cvr arnd and a slgt chc to low chc PoPs of shwrs into the
weekend. For now, we discounted the latest 12z ECMWF dtmnstc run
with the Gulf system tracking alg the E coast toward Nova
Scotia, which is not supported attm by long range ensm model
solutions, but something to watch as we get closer to next
weekend.
&&
.AVIATION /02Z MONDAY THROUGH FRIDAY/...
NEAR TERM: MVFR ceilings will persist through late this
afternoon before clouds break, giving way to decreasing clouds
overnight with VFR conditions. VFR and light winds expected on
Monday.
SHORT TO LONG TERM: IFR/MVFR clgs and/or vsbys can be xpctd
for Nrn TAF sites in rn/shwrs/dz and patchy fog Mon ngt thru
Wed while Downeast sites remain VFR. Conditons then lower to IFR
for all TAF sites ovrngt Wed into Thu in more general rnfl
and/or patchy fog with conditions improving to VFR clgs Downeast
sites and MVFR Nrn TAF sites ovrngt Thu and contg so thru Fri.
&&
.MARINE...
NEAR TERM: Wind/seas will remain below SCA levels through
Monday.
SHORT TO LONG TERM: Initially no hdlns for Mon ngt into Tue
morn, with winds and seas building close to low end SCA
thresholds for Tue aftn/eve. Another potential SCA pd will be
from late Thu into Fri with Srly winds ahead and winds behind a
cold front. Kept close to WW3 wv hts this fcst update with
initial primary swell wv pds of arnd 10 sec Mon ngt
transitioning to short wind fetch wv pds of 4 to 7 sec on Tue
and contg so into the late week.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...None.
MARINE...None.
&&
$$
Near Term...Hewitt
Area Forecast Discussion
National Weather Service Cheyenne WY
931 PM MDT Sun Oct 7 2018
.UPDATE...
Issued at 905 PM MDT Sun Oct 7 2018
Complex weather situation over the next 48 hours, which will
likely have impacts into Tuesday night and possible Wednesday as a
secondary trough moves into the area. Most locations across
southeast Wyoming are observing fog with drizzle along the I-25
corridor. West of I-25 shows periods of off/on light snow with
some dense fog in and near the mountains, such as the Laramie
Range and northern slopes of the Snowy Range. Cold air is starting
to move into the eastern plains with mid 30s reported across
mainly locations, although the southern Nebraska panhandle still
shows temperatures in the low 40s at this hour with drizzle and
light rain. Colder air is actually a little ahead of schedule,
even based on the colder 12z NAM guidance.
Expect a gradual increase in snow with lowering snowlevels west
of I-25, with some snow accumulations expected by early Monday
morning. Not so clear along and east of I-25, especially across
the eastern Wyoming plains and the northern Nebraska panhandle
where a mix of freezing drizzle, light snow, and patchy dense fog
are all possible. Although the NAM continues to show very light
QPF in drizzle, most other models including the high res HRRR show
bands of precipitation moving northward out of Colorado, with
some of these bands containing moderate to heavy precipitation.
The initial band is currently across central/eastern Colorado and
rapidly pushing northward. Question remains, will it hold together
or will dry air aloft result in a gradual decrease in coverage.
For now, delayed the onset of freezing drizzle by a few hours due
to temperatures holding above freezing through midnight, and
increased the chances for snow, mainly across the eastern plains
of southeast Wyoming. May actually see a combination of some snow
and ice accumulation along and just east of I-25 with mainly rain
and drizzle across the southern panhandle through Monday morning.
&&
.SHORT TERM...(Tonight - Tuesday Night)
Issued at 327 PM MDT Sun Oct 7 2018
An early season winter storm will impact a large portion of south
east Wyoming and the western Nebraska Panhandle over the next 24-
36 hours. The main forecast challenges continue to revolve around
multiple precipitation types, as well as the placement of a heavy
band of rain or snow later on Monday.
A vigorous upper-level low continues to dig into the Four Corners
region this afternoon. An excellent fetch of deep low & mid-level
moisture was observed streaming northward across CO/NM per recent
GOES-16 Water Vapor satellite imagery. Easterly low-level upslope
will continue to support fog along/E of the Laramie Range, mainly
over the I-80 Summit & adjacent foothills where locally dense fog
persists this afternoon. The Dense Fog Advisory has been extended
until 3 AM MDT. Precipitation is likely to become more widespread
over the next few hours as multiple pieces of energy eject north-
east from the parent trough. NAM/GFS forecast soundings suggest a
change over from rain to snow for Further tracking of high-res model
solutions and additional forecast will continue to track potential
for both sites. r most areas west of I25 by 0z or so.
Sounding profiles remain very intriguing along & east of I25 over
night and through Monday. Deep saturation between 0 and -10 deg C
with dry air aloft suggests minimal ice crystal introduction, and
thus the potential for freezing drizzle. Model cross sections are
also showing deep upward omega within this layer, so we could see
heavier drizzle leading to ice accumulation. High-res guidance is
suggesting areas of up to two tenths of an inch over the northern
Nebraska Panhandle and areas near Cheyenne. Soundings continue to
support freezing drizzle potential thru late Monday night, so the
consensus was to issue a Winter Weather Advisory from 03z tonight
until 12z Tuesday for areas along/east of the Laramie Range. Snow
will eventually begin to fall as cold air damming develops during
the afternoon on Monday. This could result in extremely dangerous
travel conditions.
On Monday afternoon/evening, the models show strong dynamics with
a 120-130 knot H25 jet extending from north-south across the high
plains. Low-level convergence along a pronounced inverted surface
trough extending from a 995-998 mb low in southern CO should help
provide further forcing for ascent. A variety of models show some
variation of a heavier frontogenetical band of snow, but disagree
on the exact placement somewhere between Rawlins & the Interstate
80 Summit. It is quite possible this band may drop well in excess
of 6 inches of snow, but uncertainties preclude any upgrades to a
Winter Storm Warning at this time. We did, however, decide to add
a Winter Weather Advisory to remaining lower elevation zones over
western area including Laramie/Rawlins. Later shifts will need to
monitor this closely. Precipitation is expected to gradually come
to an end by Tuesday morning.
.LONG TERM...(Wednesday - Sunday)
Issued at 327 PM MDT Sun Oct 7 2018
A brief break of precipitation could occur Tuesday night through
mid-day Wednesday but another quick moving winter storm could
shift across the region late Wednesday into early Friday of next
week. Another round of winter weather advisories could be needed
for this time frame.
Model disagreements occur by mid-week as the EC is more
progressive with another shortwave trough over WY while the GFS
delays the shortwave by 18 hours. Despite this timing difference
both models indicate increased divergence aloft and supportive
cold temperatures for more snow mid- to late-week. Travel impacts
could be possible again so stay tuned to the latest following
this first round of winter weather.
&&
.AVIATION...(For the 00Z TAFS through Monday afternoon)
Low CIGS, precipitation and low VIS will keep TAF sites fluctuating
back and forth between mainly IFR and LIFR conditions through the
period. Expecting light rain and drizzle to transition over to snow
during the overnight hours, especially along and west of I-25.
Concern after 06z will be the development of freezing drizzle across
the southeast Wyoming plains and the northern Nebraska panhandle.
Confidence is increase with the potential of a light glaze by Monday
morning. IFR to LIFR conditions will likely persist through Monday
with periods of rain/snow, drizzle, and snow.
&&
.FIRE WEATHER...
Issued at 349 AM MDT Sun Oct 7 2018
Mountain snow and valley rain over the next few days will
significantly limit fire weather concerns over the course of
the next week. Cooler temperatures will also aid in fire
containment issues. A brief break in shower potential Tuesday
night into Wednesday will be followed by another round of snow by
Thursday.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...Winter Weather Advisory until 6 AM MDT Tuesday for WYZ101>110-
112-113-115>119.
Dense Fog Advisory until 3 AM MDT Monday for WYZ116-117.
Winter Storm Warning until 6 AM MDT Tuesday for WYZ114.
NE...Winter Weather Advisory until 6 AM MDT Tuesday for NEZ002-095-
096.
&&
$$
UPDATE...TJT
SHORT TERM...CLH
LONG TERM...JSA
AVIATION...TJT
FIRE WEATHER...AB
Area Forecast Discussion...UPDATED
National Weather Service Austin/San Antonio TX
700 PM CDT Sun Oct 7 2018
.AVIATION...
/00Z TAFS/
Cigs/vsbys should remain VFR for the most part for the I-35 sites
this evening. Cigs are expected to lower to MVFR category around
midnight tonight for KAUS, KSAT and KSSF and stay that way through
late Monday morning. Some showers are expected across these terminals
mainly by day break on Monday with a second round of scattered
showers and thunderstorms from mid to late afternoon. During that
time, cigs and vsbys should be MVFR. Winds are expected to be from
the southeast at around 10 knots for most of the forecast period with
higher gusts during thunderstorm activity.
KDRT is expected to be impacted by thunderstorm activity this
evening into the overnight hours with storms moving across or nearby
the terminal for the period. These storms are capable of producing
frequent cloud to ground lightning and wind gusts of 20 to 25 knots.
There may be a break around 07Z Through 09Z with most of the
activity to the east of the airport and VFR cigs could occur for a
short period before going back down to MVFR through mid afternoon on
Monday.
&&
.PREV DISCUSSION... /ISSUED 247 PM CDT Sun Oct 7 2018/
SHORT TERM (Today through tonight)...
The current weather pattern is characterized by a large, high
amplitude trough across the western CONUS with the center of the
upper low currently situated over northern Arizona/southern Utah and
slowly progressing eastward. This has yielded southwest flow aloft
across south central Texas, which is bringing a steady stream of
Pacific moisture across Mexico and into the region, primarily focused
out west along the Rio Grande (which can be seen via GOES-16 water
vapor imagery). PWATs, as analyzed by the SPC mesoanalysis, are up to
1.7" in this area, which registers above the 90% percentile per
climatology. A few subtle perturbations embedded within the upper
level flow as well as weak forcing due to some weak positive
vorticity advection from the approaching trough, paired with this
area of ample moisture, will create the threat for heavy rainfall
this evening and overnight tonight across the Rio Grande and southern
Edwards Plateau. The SPC HREF shows a strong signal for heavy
rainfall, and single deterministic CAMs such as the HRRR and the NAM
nest also continue to suggest a locally heavy rainfall threat for
this region. As such, WPC does indeed highlight this area with a
slight risk for excessive rainfall. Thus, a Flash Flood Watch has
been issued for this region and will be in effect from 7 pm tonight
through 7 am Monday.
While the focus for heavy rainfall should remain confined to the
western portions of the region, the rest of south central Texas
should see isolated to scattered showers and thunderstorms overnight
tonight, with overnight lows ranging from the low to mid 70s.
LONG TERM (Tuesday through Sunday)...
Scattered to widespread showers and thunderstorms are expected to
continue through Wednesday morning as the region remains under the
influence of the approaching trough and eventual surface cold front.
Locally heavy rainfall will be possible, and even some strong to
marginally severe storms are also possible. The trough axis and cold
front should move through the region on Wednesday, bringing rain
chances to an end as weak upper level ridging begins to build. Highs
will be in the upper 70s to low 80s for Thursday through Saturday
with lows in the upper 50s to mid 60s. Highs on Sunday are only
expected to reach the low to mid 70s across the region.
The remnants of Hurricane Sergio (in the Pacific) will come ashore
across Baja California and is progged to be absorbed into an upper
level trough in the vicinity of the desert southwest. This feature may
approach the region as we head into next weekend, so have re-
introduced some 20 to 30 percent PoPs for Saturday and Sunday.
&&
.PRELIMINARY POINT TEMPS/POPS...
Austin Camp Mabry 73 83 72 83 68 / 30 50 40 80 60
Austin Bergstrom Intl Airport 73 84 72 84 68 / 30 50 40 80 60
New Braunfels Muni Airport 72 83 72 84 68 / 30 50 50 70 60
Burnet Muni Airport 71 80 70 80 64 / 30 50 50 80 50
Del Rio Intl Airport 71 82 70 84 65 / 80 60 60 60 20
Georgetown Muni Airport 72 83 72 82 66 / 30 50 40 80 60
Hondo Muni Airport 73 82 72 84 67 / 60 60 50 70 40
San Marcos Muni Airport 72 83 72 85 68 / 30 50 50 70 60
La Grange - Fayette Regional 74 87 74 87 70 / 20 40 30 60 60
San Antonio Intl Airport 73 83 73 85 69 / 40 50 50 70 50
Stinson Muni Airport 73 83 73 85 70 / 40 50 50 70 50
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
Flash Flood Watch through Monday morning for Bandera-Edwards-Kerr-
Kinney-Maverick-Real-Uvalde-Val Verde-Zavala.
&&
$$
Mesoscale/Aviation...17
Synoptic/Grids...Huffman
Area Forecast Discussion
National Weather Service Wilmington OH
926 PM EDT Sun Oct 7 2018
.SYNOPSIS...
Very warm and humid weather will persist through mid week with
high pressure centered off the Atlantic Coast. A strong cold
front will push through Wednesday night into early Thursday
morning. Temperatures will fall below normal for the end of the
week.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
A semi stationary boundary situated across northern Indiana and
northern Ohio this evening looks to be making a bit of a
southward push across our far northern areas. This has allowed
for some lower clouds and areas of fog to work down into a few
or our northwest counties over the last couple of hours. How far
these clouds actually make it is somewhat in doubt, but the
last few runs of the HRRR suggest they should not make it too
much farther south, before possibly retreating a bit later
tonight. Given the current push as noted on satellite though,
will allow for the clouds to make it a little farther south than
suggested by the HRRR and then also be a little slower to trim
them back later tonight. Elsewhere across our area, expect
mainly clear skies overnight. This will likely allow for some
areas of river valley fog to develop across our southern areas
later tonight. Overnight lows will be in the mid to upper 60s.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
Stagnant pattern results in little change in conditions from day
to day. Cumulus will develop with heating and isolated afternoon
convection will be possible. Clouds will diminish at night.
Highs and lows will remains near persistence.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
The expansive and anomalously strong mid/upper level ridging that
has remain anchored across the mid-Atlantic region for several days
will become somewhat suppressed and flattened by late Tuesday into
early Wednesday. Before this occurs, one more day of /very/
unseasonable temperatures will linger in the Ohio Valley, with highs
in the mid/upper 80s and lows in the upper 60s for Tuesday night.
Although pcpn chances should remain relatively low on Tuesday, due
mainly to the lack of any focused forcing, low-level boundary
conditions more representative of a typical August day should lend
itself to at least a non-zero threat of a spotty shower/storm during
peak diurnal heating. This threat, should it evolve, would be
favored for western portions of the ILN FA.
By Wednesday a major pattern shift will begin its transition as a
potent trof over the central U.S. pivots northeastward, shunting the
best midlevel ridging further south/east of the Ohio Valley. Dynamic
forcing, including influences of an enhancement of the low level
jet, should allow for an increase in precipitation during the day on
Wednesday -- initially from the south/west before pcpn associated
with the front itself holds off until mainly the overnight period.
Guidance has come into a bit better agreement with timing the FROPA
through the ILN FA (06-12z Thursday), but there continue to be some
discrepancies in depiction of the pre-frontal environment and just
how much precipitation will be present before frontal forcing
increases and takes over late Wednesday evening. The GFS continues
to show a bit more widespread pcpn during the day Wednesday,
including in the morning, while the ECMWF shows the bulk of the pcpn
holding off until the front actually begins to progress east through
the Ohio Valley (Wednesday evening and beyond). Nevertheless, an
increase in shower with embedded thunderstorm activity is expected
from both the south and the west Wednesday evening into the
overnight period. There remains some uncertainty as to the degree of
instability that will remain entrenched in the pre-frontal
environment during this period, but dynamics and sufficient (but not
overly strong) deep-layer shear itself should at least lend itself
to widespread rain showers, even if instby remains somewhat lacking.
This setup will be monitored in the coming days, but model guidance
has remained fairly consistent showing the upper level energy being
strung out and becoming less focused as the front pushes through the
local area. This would suggest that any severe potential should
remain on the low side, but the specifics, including
juxtaposition/overlap of greatest forcing/shear/instability, will
continue to be watched in the coming days.
A sharp transition to drier and cooler air will occur in the area
early Thursday morning, with many locations drying out during the
daytime period as best shower/storm coverage moves south/east of the
local area. Highs will range from the lower 60s in the northwest to
the upper 60s in the southeast before lows drop into the low/mid 40s
area wide Thursday night. Highs near 60 degrees are anticipated for
Friday.
Model solution spread begins to increase towards next weekend and
therefore confidence decreases in exactly when the next chance for
precipitation will arrive. However, current long-range data
suggests that a secondary shortwave will provide a reinforcing
shot of cool air late Friday, setting the stage for temperatures
that will actually be below normal by next weekend.
&&
.AVIATION /01Z MONDAY THROUGH FRIDAY/...
Mostly clear skies are expected overnight. With relatively
light winds, some areas of mainly river fog will likely develop
once again later tonight. This will mainly affect KLUK where
some VLIFR conditions will be possible late tonight into early
Monday morning. Otherwise, expect to see some sct cu
development through the day on Monday. An isolated shower or
thunderstorm can not be ruled out Monday afternoon, but chances
are low enough to leave any mention out of the TAFs.
OUTLOOK...No significant weather is expected at this time.
&&
.CLIMATE...
Anomalous upper level ridge centered over the eastern conus
will offer summer like temperatures into early next week. Below
is a table of records for Sunday 10/7 through Wednesday 10/10.
CVG
Record highs and year Highest Minimum Temperature and year
10/7 90 in 2007 10/7 68 in 1982
10/8 91 in 2007 10/8 69 in 1939
10/9 90 in 1939 10/9 70 in 1982
10/10 89 in 1913 10/10 69 in 1883
DAY
Record highs and year Highest Minimum Temperature and year
10/7 89 in 2007 10/7 66 in 1931
10/8 88 in 2007 10/8 68 in 1939
10/9 86 in 1939 10/9 69 in 1939
10/10 86 in 2010 10/10 66 in 1904
CMH
Record highs and year Highest Minimum Temperature and year
10/7 91 in 2007 10/7 68 in 1879
10/8 90 in 2007 10/8 68 in 1879
10/9 88 in 1939 10/9 69 in 1879
10/10 87 in 2010 10/10 66 in 1879
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...None.
KY...None.
IN...None.
&&
$$
SYNOPSIS...
NEAR TERM...JGL
SHORT TERM...
LONG TERM...KC
AVIATION...JGL
CLIMATE...
Area Forecast Discussion
National Weather Service Pueblo CO
352 PM MDT Sun Oct 7 2018
.SHORT TERM...(This evening through Monday)
Issued at 351 PM MDT Sun Oct 7 2018
...Snow for the higher mountains, thunderstorms for the plains some
potentially strong to marginally severe tonight and again on
Monday...
Closed upper low is currently spinning across southern UT/northern
AZ and will send impulses of energy northeastward across CO tonight
and Monday. The upper low is not progged to move that much tonight
before gradually lifting northeastward through Monday. First impulse
and round of thunderstorms will lift northeastward this
evening...spreading heavy snow into the eastern San Juan mountains
and a line of thunderstorms across the southeast plains as strong
upglide overtop of the frontal boundary allows elevated CAPE to be
realized. Plenty of shear for a few strong to perhaps severe
thunderstorms across southern portions of the southeast plains this
evening...however will have to wait for mid level lapse rates to
steepen a bit more this evening. HRRR continues to indicate a line
of thunderstorms developing across the I-25 corridor and northeast
NM...which lifts northeastward across the southeast plains through
the night. There will likely be a few rounds of
showers/thunderstorms with the heaviest rainfall potential east of a
line from La Junta to Kim...with the best chance across Baca county.
Earlier runs were also hinting at the possibility for training
thunderstorms across portions of El Paso county but have since
shifted the heavier precipitation east a bit. Will carry highest
pops across the Continental Divide, far eastern plains and northern
El Paso county.
Snow levels will be dropping to around 9.5-10kft across the
mountains and waves of convective showers will result in the
potential for advisory criteria snowfall for the higher elevations
above 10kft. How quickly snow levels drop will play a large role as
far as impacts to travel...but given this is an early season storm,
and there is the potential for some locally intense snowfall at
times across the passes, will put up a winter weather advisory for
the eastern San Juan mountains tonight through Monday evening. Snow
will be off and on in nature tonight...with a lull towards morning,
then potentially another round or two tomorrow. All in all, not a
terribly heavy event with sustained accumulations...but grids have
solid advisory snowfall amounts for this area. Higher elevations of
the Sawatch range will also pick up some snowfall accumulations but
with less favorable orographics during the early part of the storm
will limit impacts there.
Models still differ with the placement of the front on Monday across
the plains with GFS still lifting the front the farthest north
across northeast CO. NAM keeps the front south of the Arkansas
River through much of the day before advancing it back southward
towards the New Mexico border towards 00z. Have sided closer to the
NAM solution and kept generally cooler/wetter conditions to the
north...and warmer conditions to the south. Will have to watch Baca
county closely for the potential for severe thunderstorms...though
it does appear that threat will be shifting south of the area during
the afternoon. Across the rest of the area...expect waves of showers
and isolated embedded thunderstorms through the day with best
chances across the mountains. Snow levels hover around 9000-10kft
through the day.
.LONG TERM...(Monday night through Sunday)
Issued at 351 PM MDT Sun Oct 7 2018
...Freezing temperatures across portions of Southeast Colorado
Tuesday night and Wednesday night...
Monday night-Tuesday night...Still some differences in timing and
location of the broad upper trough lifting out across the area
Monday night and Tuesday with the 12Z GFS remaining a tad further
north and not as cold as the further south solutions of the NAM, EC
and Canadian models. With that said, the forecast followed the
consensus blend with the further south solutions bringing a sharper
cold front across all of the Eastern Plains Monday night. The best
precipitation chances are expected over and near the higher terrain
Monday evening, shifting to the far southeast plains Monday night
and into Tuesday morning, with moisture and lift associated with the
trough overrunning the colder air behind the passing system. West to
northwest flow aloft increases again through the day Tuesday, as
more energy digs across the Pacific Northwest and into the Northern
Great Basin Tuesday afternoon. This will lead to scattered showers
for areas over and near the higher terrain once again, with showers
diminishing across the far Southeast Plains, with subsidence and
downslope flow, with showers across the higher terrain diminishing
Tuesday evening. As for snow fall, snow levels drop to around 6000
ft Monday night, with a dusting of snow possible across the Palmer
Dvd and a few inches possible across all of the higher terrain as
the trough lifts out, with accumulations of 1 to 4 inches possible
across the higher terrain again on Tuesday, with best accumulations
across the Central Mts with the westerly orographic flows. Could
also see temperatures across the San Luis Valley and along the
Palmer Dvd fall into the upper 20s to lower 30s Tuesday morning, as
colder air associated with the passing system filter into the
region. With that said, issued a freeze watch for these areas,
including Colorado Springs and southern El Paso County Tuesday
morning. A more widespread freeze looks in the offing across
Southeast Colorado Tuesday night into Wednesday morning.
Wednesday-Sunday...Low confidence in weather pattern through the
rest of the work week into next weekend, with continued timing and
location differences of more Pacific Northwest energy digging across
the Great Basin and the Rockies. Even bigger differences in models
for Friday into Sunday, as the operational GFS is taken the remnant
moisture Pacific Hurricane Sergio across New Mexico and into
Colorado by next Saturday. This solution is an outlier and followed
the blended models which keeps any moisture associated with the
remnant tropical system well south of the area. At any rate,
another upper trough translates across the area Wednesday and
Thursday, with best precipitation chances remaining across the
higher terrain along and west of the ContDvd Wednesday, with pops
spreading east across all of the higher terrain Thursday and across
the Southeast Plains Thursday night with another frontal passage.
Drier and warmer westerly flow then looks to be in the offing for
Friday and into next weekend.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 351 PM MDT Sun Oct 7 2018
MVFR to IFR stratus will fill back in across the plains this evening
with the potential for LIFR conditions returning at KCOS through the
evening. A wave of showers and embedded thunderstorms may develop
across the I-25 corridor this evening before shifting eastward
tonight. There may be a window for -SHRA/-TSRA in both KCOS and
KPUB this evening as this line of showers and thunderstorms takes
shape. Tonight...activity will shift eastward and the cold front
will advance back southward into the plains bringing a northerly
wind shift to both KCOS and KPUB after 06z. This will help raise
Cigs and Vis at KCOS and KPUB though cigs may still remain in the
IFR to MVFR category. On Monday...persistent IFR to MVFR conditions
will be possible with rounds of showers possible for both terminals.
KALS will continue to see gusty southwest winds 20 to 40 kts this
evening before winds decrease to around 10-15 kts overnight. VCSH
will be possible at the TAF site through Monday morning. Winds will
increase again from the south by mid morning.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory from 6 PM this evening to midnight MDT
Monday night for COZ068.
Freeze Watch from late Monday night through Tuesday morning for
COZ069>071-084-085.
&&
$$
SHORT TERM...KT
LONG TERM...MW
AVIATION...KT
Area Forecast Discussion
National Weather Service Tucson AZ
855 PM MST Sun Oct 7 2018
.SYNOPSIS...Expect isolated to scattered showers and thunderstorms
with unseasonably cool temperatures into Monday afternoon. Drier
conditions with a warming trend will occur Tuesday into Wednesday.
However, daytime temperatures will remain several degrees below
normal. Increasing moisture from tropical system Sergio should bring
more showers and thunderstorms later this week.
&&
.DISCUSSION...Isolated to scattered showers and thunderstorms were
occurring at this time across southeast Arizona. A northeast-to-
southwest oriented line of shower and thunderstorms extended from
south of Clifton to east of Sierra Vista. This line of showers/
tstms was adjacent a surface cold front that continues to move
eastward. Meanwhile, additional showers and thunderstorms were
mainly across eastern Pima County including the Tucson metro area.
Finally, other isolated showers/tstms were moving eastward across
south central Pinal County. Mostly cloudy to cloudy skies prevailed
elsewhere.
Various HRRR solutions as well the 08/00Z NAM12 were quite similar
with depicting showers/tstms to decrease in coverage during the next
few hours, with the bulk of showers/tstms progged to end by around
09Z Monday (2 am MST Monday). Thereafter, these solutions remained
quite consistent with depicting generally precip-free conditions
through Monday morning. Showers/tstms are then depicted to be mainly
confined Monday afternoon only to the White Mountains or perhaps as
far south as Safford. Dry conditions are depicted elsewhere Monday
afternoon.
Although these solutions seem fairly reasonable with the bulk of
showers/tstms Monday to be mostly north of this forecast area, cold
mid-level temps associated with upper trough over the area and
residual moisture may generate showers/tstms further southwestward
than suggested via these solutions.
Thus, the official forecast was updated for the rest of tonight and
Monday with PoPs trended downward versus the inherited forecast. The
upshot is that showers/tstms should continue to decrease in coverage
during the next few hours with isolated showers/tstms later tonight
closer to the New Mexico state line. Scattered showers/tstms to
redevelop Monday afternoon especially east of Tucson, and have opted
for precip-free conditions across western Pima County.
Forecast high temps Monday across much of the area will be a few
degrees cooler versus this afternoon. However, high temps Monday
across far southeast sections including Douglas will be nearly 10
degrees cooler versus today. As such, high temps Monday will range
about 5-15 degrees below normal depending upon location.
Please refer to the additional sections for further detail.
&&
.AVIATION...Valid through 09/06Z.
Isolated to scattered -TSRA/-SHRA mostly ending around 07Z-09Z
Monday followed by generally dry conditions through Monday morning.
Scattered -TSRA/-SHRA Monday afternoon and evening especially east
of KTUS. MVFR conditions and brief IFR conditions with stronger
TSRA. Otherwise, cloud decks generally 4k-8k ft AGL into Monday
evening. Surface wind variable in direction mostly less than 12 kts.
Aviation discussion not updated for TAF amendments.
&&
.FIRE WEATHER...Scattered showers and thunderstorms redeveloping
Monday afternoon with the greatest coverage expected east of
Tucson. Rain coverage and chances decrease Monday night. A
few lingering showers may occur Tuesday across the White Mountains.
Otherwise, dry conditions Tuesday into Wednesday with daytime
temperatures remaining several degrees below normal. Increasing
moisture associated with tropical system Sergio is expected to
provide more showers and thunderstorms later this week. 20-foot
winds terrain driven generally under 15 mph much of this week.
&&
.CLIMATE...The forecast low temperature at Tucson International
Airport Monday morning is 54 degrees. The last time when the low
temperature was this cool, or cooler, was May 4 when the recorded
low temperature was 52 degrees.
Also, the record rainfall for Tucson on October 7 is 0.64 inch
recorded in 1977. The measured rainfall through 8:45 pm MST today
at Tucson International Airport is 0.40 inch.
&&
.PREV DISCUSSION /157 PM MST/...As we slide into Monday the deep
upper trough axis is sitting over the area which will result in a
cool day with scattered showers developing in the afternoon. The
dynamics will be east of the area so the convection will be weaker
and random in nature with fairly low snow levels pushing near 8000
feet. It will likely be the coolest day of the week with many higher
elevation valleys remaining in the 60s and the lower deserts
struggling to reach the mid 70s.
Tuesday into Wednesday we will be on the back side of the upper
trough with drier conditions and warming but still cooler than
normal temperatures. This period is just the calm before the storm?
Models continue to indicate that the area will be impacted by the
remnants of Sergio in some form or fashion in this complex large
scale pattern that is evolving. Last nights solutions handled the
interaction between the tropical system and the westerlies in a very
different manner than the previous runs with more recent runs sorta
leaning back to what was there before with significant differences
between the GFS and the ECMWF. Have leaned toward the GFS a bit as
it was the better model with Rosa. That said, we are still five days
out with a complicated situation that models have historically had a
problem resolving at longer time ranges so we will continue to
monitor and adjust as needed.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...None.
&&
$$
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