Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 10/13/17
Area Forecast Discussion
National Weather Service La Crosse WI
633 PM CDT Thu Oct 12 2017
.SHORT TERM...(This evening through Friday)
Issued at 238 PM CDT Thu Oct 12 2017
Afternoon upper air analysis showed a ridge axis moving through
lower Michigan with surface analysis showing a surface trough and
cold front extending north to south across the Dakotas. Low clouds
remained in the area throughout the day, but continue to slowly
decay from from west to east from central Minnesota into north-
central Missouri. May see a brief break in the clouds by late
Thursday afternoon/early evening, but additional clouds will quickly
move in/develop as the cold front approaches the area from the west.
RAP BUFKIT soundings have consistently shown saturating low levels
after midnight, especially east of the Mississippi River, coupled
with decent negative omega and some isentropic lift, so have added
drizzle mention for these areas.
For Friday, 12Z guidance shows the surface cold front moving into
the northwest part of the forecast area by Friday morning, with
frontogenesis increasing across the southern part of the forecast
area during the afternoon. The best moisture transport does not
reach the area until Friday evening, so have delayed the highest
PoPs a bit, but rain still appears likely for much of the southern
half of the forecast area by late Friday afternoon. Any instability
looks to remain to the south during this time period, so have left
out thunder mention.
.LONG TERM...(Friday night through Thursday)
Issued at 238 PM CDT Thu Oct 12 2017
Wave of low pressure rides up along the baroclinic boundary laid
up across eastern IA into northern IL Friday night into Saturday
morning. Increasing moisture transport/isentropic lift over this
frontal boundary will produce more showers and a few
thunderstorms, mainly across far northeast IA/southwest WI.
Will continue to keep a close eye on Saturday afternoon/evening as
our far southeastern forecast area will be on the cusp of being in the
warm sector. Right now, looks like better CAPE stays just to our
southeast. However, if we can get a bit deeper into the warm
sector/better CAPE, we will have more than plenty Bulk Shear and
impressive hodographs for a severe storm threat. Will maintain
mention of a few stronger storms in the Hazardous Weather Outlook.
Another aspect to consider will be heavy rain threat as
precipitable water values creep up into the 1.5-2 inch range.
Attention then turns to strong/deepening low pressure coming
through the area later Saturday night into Sunday. Most models
have central pressure dropping 15-20mb in 12 hr (Sun 00-12z) as
the low lifts from northeast IA into eastern Lake MI...impressive!
Models drive a dry slot into the area as the low pulls into
northeast WI/southern Upper MI. At the same time, expecting winds
to pick up significantly from the west as the low rapidly deepens.
Could see winds sustained in the 20-30 mph range with some gusts
over 40 mph through Sunday morning, then tapering through the
afternoon as the low pulls into eastern Ontario. Cooler air also
filters in on these gusty winds with highs only in the upper 40s
to the middle 50s.
Clear/cold conditions set up for Sunday night/Monday morning as
high pressure settles in across the region. Lows will be in the
30s and looks like it will produce frost for the majority of the
area.
Looks like quiet conditions then through Thursday as a ridge of
high pressure builds over the central CONUS. Temperatures are
expected to be at or a couple degrees above seasonal normals.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 633 PM CDT Thu Oct 12 2017
A tricky cloud/ceiling forecast through the overnight hours. Some
clearing made its way into the RST area briefly late this
afternoon, though lower clouds are again increasing from the south
at this very moment and should result in a return to MVFR ceilings
by 01Z at the latest. LSE looks to remain socked in with MVFR
conditions through the night, but with a risk that ceilings will
lower even farther to IFR levels around RST as moisture deepens
just ahead of an approaching cold front. Seeing enough signals
that will occur to justify taking them down to IFR by around 05Z,
though the exact timing could slip. Similarly, should clouds by
chance clear out for a little while, there could be a risk for
some fog at RST as well, though confidence on that is very low.
Things should improve back to VFR levels from west to east as the
front passes during the morning hours, though thicker mid level
clouds and some showers are expected into the afternoon and
evening hours of Friday. Winds will start off southerly and then
swing around northerly by later Friday, generally in the 8-15 knot
range.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
IA...None.
&&
$$
SHORT TERM...CA
LONG TERM...DAS
AVIATION...Lawrence
Area Forecast Discussion
National Weather Service Grand Rapids MI
1012 PM EDT Thu Oct 12 2017
LATEST UPDATE...
Update
.SYNOPSIS...
Issued at 317 PM EDT Thu Oct 12 2017
A cloudy night with pockets of light drizzle will give way to
partial sunshine and milder temperatures on Friday. A frontal zone
will waver over the area Friday night through Saturday night as a
wave of low pressure tracks through the northern Great Lakes.
Occasional rain and thunderstorms will develop in the vicinity of
this front. Appreciable rain appears likely in areas north and
west of Jackson, with a soaking rainfall over 2 inches possible in
Central Lower Michigan. Cooler and drier weather will be in place
early next week followed by moderating temperatures mid-week.
&&
.UPDATE...
Issued at 1012 PM EDT Thu Oct 12 2017
Have issued a quick update to expand the mention of patchy
drizzle to include the entire area. Several ob sites have carried
drizzle this evening or have had rain began/end times in the
remarks indicative that some light precip has occurred. This
should continue on and off overnight as RAP bufkit overviews
show ocnl weak omega in the cloud layer.
&&
.SHORT TERM...(This evening through Saturday night)
Issued at 317 PM EDT Thu Oct 12 2017
A moisture-laden thermal trough at 850 mb will advect through the
area tonight. Steep lapse rates within the stratus layer (between
about 1 to 5 kft AGL) may encourage enough upward vertical motion
to grow droplets large enough to precipitate. Low-level moisture
in areas north of Holland and Grand Rapids will be augmented by
flow off Lake Michigan. As such, the greater potential for precip
tonight will be in west-central Lower Michigan. Dry air in layers
colder than +3 C and a lack of cloud ice in the column will limit
the potential for measurable precipitation, as cloud droplet size
may only grow large enough for drizzle.
Warmer low-level air (around 10C at 850mb) will flow into the area
on Friday. With breaks in the clouds, could see highs reaching 70
near/south of Holland to Lansing.
Light rain will overspread portions of the area Friday night under
mid-level moisture transport and isentropic ascent. There may be
just enough elevated instability for convection to reach the -10 C
layer to introduce thunder chances early Saturday morning.
Occasional thunderstorms will develop Saturday in the vicinity of
the surface warm front, which should lift north late Saturday as
southerly flow strengthens ahead of the deepening surface low.
Temperatures could reach the mid 70s in southern Michigan if rain
stays north.
Stronger storms with locally heavy rainfall are possible Saturday
evening and overnight as low level winds a couple thousand feet
off the surface exceed 50 knots, MUCAPE values climb above 500
J/kg, and PW values climb to around 1.5 inches. If the surface
stays warm enough overnight to maintain DCAPE where elevated
convection tracks, isolated severe wind gusts would not out of the
question. Rainfall potential is discussed further in the Hydrology
section.
.LONG TERM...(Sunday through Thursday)
Issued at 317 PM EDT Thu Oct 12 2017
Strong storm system will be exiting the region Sunday...leaving
significantly colder air and a strong and gusty west to northwest
wind in its wake. Strong cold advection will likely result in
falling temperatures Sunday afternoon...indicated in the grids.
Sunday night frost could be more widespread than currently
indicated if the wind can ease faster than expected.
Cold air will linger Monday but warmer air will return quickly in
the progressive mid level flow. Strong warm advection pattern
develops later Tuesday into Wednesday...which should provide a
return to unseasonably warm temperatures. Dry frontal passage on
Thursday will be followed by another episode of warm and windy
weather into next weekend.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 755 PM EDT Thu Oct 12 2017
Widespread/persistent MVFR conditions are expected tonight into
Friday morning, with ceilings of 1500-2500 ft and ocnl reductions
of vsbys to 3-5 miles due to areas of drizzle/mist. Localized IFR
conditions are also possible tonight and early Friday.
Conditions on Friday afternoon are expected to improve to VFR,
with the highest confidence and quickest arrival anticipated south
and east of GRR. MKG could stay locked in with MVFR cigs Friday
afternoon due to moist southwest flow off Lk MI.
&&
.MARINE...
Issued at 317 PM EDT Thu Oct 12 2017
Winds veering southwest tonight will build waves to 2-3 feet north
of South Haven on Friday. Winds will shift southeast on Saturday
but thunderstorms are a possibility. Gales appear increasingly
likely Saturday night into Sunday.
&&
.HYDROLOGY...
Issued at 1236 PM EDT Thu Oct 12 2017
We are monitoring the potential for heavier rains and possible
flooding for this weekend. A frontal system settling over the area
beginning Friday night and lasting into Sunday will bring multiple
periods of rain.
Precipitable water values will be about as high as possible by
mid-October standards with values over 1.5 inches expected. This
will bring the potential to see locally heavier downpours, and
some narrow bands of heavier accumulations through the period.
The axis of the heaviest rain for now looks to occur generally
north of a line from South Haven to Saginaw Bay. This is still
subject to change depending on where exactly the front sets up.
Right now, heaviest amounts looks to be over 2 inches, with some
areas possibly seeing locally up to 4 inches.
Thankfully this is displaced a little north from the heavier
rains earlier this week. We still could be looking at some minor
flooding.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...None.
LM...None.
&&
$$
UPDATE...Meade
SYNOPSIS...CAS
SHORT TERM...CAS
LONG TERM...MWS
AVIATION...Meade
HYDROLOGY...NJJ
MARINE...CAS
Area Forecast Discussion
National Weather Service Wilmington NC
929 PM EDT Thu Oct 12 2017
.SYNOPSIS...
A cold front will drop southward across the area tonight and
further south before stalling in the vicinity of the Savannah
River late Fri. High pressure will follow and ridge across the
Carolinas from the NE States Fri thru Sunday. A much stronger
cold front will approach the area from the northwest early
Monday of next week, sweeping across the region and off the
Carolina coasts to well offshore by early Tue. Look for a return
to normal temperatures under cool high pressure for the mid to
late week period of next week.
&&
.NEAR TERM /THROUGH FRIDAY/...
As of 845 PM Thursday...A broken line of convection has now
developed across the ILM CWA, extending from Wilmington across
Whiteville, Mullins, Effingham to Lamar. This broken line
is basically the cool front that is slowly dropping southward
across the FA. Looking at the soundings, the post frontal
airmass remains quite shallow in the vertical with moisture
trapped below the low level temp inversion. Will likely observe
low stratus cloud decks later tonight thru atleast midday Fri
with ceilings in the 500 ft to 1500 ft range, with lowest
ceilings in a 5 hr window centered at sunrise. As the airmass
after the CFP increases in the vertical, look for the low
stratus overcast cloud decks to scour out by late Fri morning,
leaving diurnally driven cu/sc clouds in it`s wake.
Low temperatures tonight will run only 15 to 20 degrees above
normal, as if it were late August. Widespread 70s for mins
except upper 60s possible across the northern portions of the
ILM CWA if enough cool air advects southward into the FA.
Previous....................................................
As of 300 PM Thursday...several distinct boundaries are
showing up on radar with the primary boundary appearing to be
the front from just north of Wilmington to Florence and then it
drops to the southwest of Florence. While there is little
forcing aloft, the surface boundaries are producing weak meso-
scale lift as convection begins to develop near them.
The latest HRRR is showing the convection continuing along
these boundaries through midnight before weakening. Overnight
the models indicate stratus and fog developing and not breaking
until the mid- day in the Carolinas. Scattered convection is
expected to develop later in the day on Friday.
Low temperatures will be in upper 60s to lower 70s on the
southern coast tonight. With the extensive cloud cover expected
on Friday high temperatures are expected in the lower 80s but
if clouds break early than forecast, highs could reach the
middle 80s.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SATURDAY NIGHT/...
As of 300 PM Thursday...High pressure to the north will
continue to extend down into the Carolinas as it shifts east
through the period. At the same time a lingering trough just
off the coast to the east will weaken. Northeast flow will
continue between the high and trough and will bring drier air
down into the area. Pcp water values will drop from around 1.5
inches Fri eve down to less than 1.25 inches on Sat. Therefore
the overall column moisture will diminish, but there will be
just enough shallow moisture to produce some fog close to
daybreak each morning lifting through the morning and some
afternoon cu Sat aftn. The model soundings show a pronounced
subsidence inversion right around 12 k ft with plenty of dry air
and subsidence above this layer. Included only a very slight
chc of pcp mainly near the coast but overall expect fair and
warm weather with temps and dewpoints lower than the past
several days, but still above normal for this time of year.
High temps will be in the lower 80s and lows in the mid 60s.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
As of 300 PM Thursday...The chief headline this period remains
the pattern change more indicative of early Autumn, arriving
early next week, as the upper trough presently over the Pacific
NW and northern Rockies, translates toward the US East Coast.
GFS and ECMWF depictions appear in very good agreement on this
scenario and certainly reckons to be more in sync with climo,
and well overdue with the exceptionally warm pattern recently.
As a result, a cold frontal passage is expected across NE SC
and SE NC Monday, with the surface front reaching the FL
peninsula by Tuesday. We may see 80s persist into Monday if the
front arrives in the afternoon, but by Tuesday, maximum
temperatures should run 9-13 degrees Fahrenheit cooler, with the
drier and cooler pattern holding through mid-week. Beyond this
, high pressure wedge pattern appears to portrayed, which should
keep a near normal temperatures regime in place. Showers or a
TSTM looks to be favored Monday ahead of the front, but looking
at cross-sections of RH and column moisture, no guarantee
because the moisture profiles are not all that wet.
&&
.AVIATION /01Z FRIDAY THROUGH TUESDAY/...
As of 00Z...MVFR/IFR conditions this evening will have the
potential to further degrade to LIFR conditions from mainly
lowered ceilings with a secondary from reduced vsby from fog.
This a result of a cool front slowly sinking south across the
area tonight, and stalling in the vicinity of the Savannah
River mouth by Fri evening. Scattered convection along and
south of the ILM to FLO line initially, will sink southward
along and ahead of the cool front overnight into Fri. Looking at
progged soundings for various TAF sites across the area, the
common sounding for all terminals is the nearly saturated air
mass from the sfc to 925mb, and a subsidence inversion
immediately on top, from 925mb to 800mb. This will result in low
stratus ceilings for tonight, mainly after the cool front that
pushes thru. A secondary result from these progged soundings is
the increasing potential for fog. The majority of the various
model MOS guidance does not hit the fog too hard, but
concentrates on the sub 1k foot ceilings that could lower 500ft
or less in a 5 hr window around sunrise Fri. Improving
conditions will be met by late Fri morning and beyond. Winds
will become NE around 5 kt after the CFP and should increase to
around 10 kt by daytime mid-morning as high pressure begins to
ridge across the forecast area from the NE states.
Extended Outlook...MVFR/IFR conditions are possible during
Fri and Sat mornings from reduced ceilings and/or vsby from low
stratus and/or fog. Isolated to scattered MVFR/IFR produced
convection is expected each day, with the best chance occurring
on Monday ahead of a strong cold front.
&&
.MARINE...
NEAR TERM /THROUGH FRIDAY/...
As of 900 PM Thursday...As the cold front slowly sinks
southward across the local area, winds will become NNE-ENE in
its wake at around 10 kt. Weak cool air advection combined with
a tightening gradient from a 1030+ mb high ridges southward from
it`s center across the NE States. Models may have winds too low
for later tonight into Fri given the latest sfc pg tightening
after the CFP along with some weak cool air advection. May have
to also bump up winds hier for Fri. Significant seas will run 2
to 3 ft with 4 footers possible outer waters off Cape Fear and
north of Romain respectively. the easterly swell at 9+ second
periods will initially dominate the seas followed by an input
from the low period NE wind driven waves.
Previous....................................................
As of 300 PM Thursday...A frontal boundary is expected to shift
off the coast overnight. Light south to southwest winds will
continue through most of the evening and turn to the northeast
after 03 UTC as the front moves off the coast. Seas will run
between to 2 to 3 feet through Friday afternoon.
SHORT TERM /FRIDAY NIGHT THROUGH SATURDAY NIGHT/...
As of 300 PM Thursday...Winds our of the northeast 10 kts or
less will weaken further through the period and become more
easterly by Sun morning as lingering trough off the coast
weakens and high pressure to the northeast dominates. Seas will
basically stay around 3 ft most waters through the period.
LONG TERM /SUNDAY THROUGH TUESDAY/... As of 300 PM Thursday...A
manageable southerly flow will prevail Sunday into early Monday,
ahead of a cold front, shifting to north sometime on Monday.
Expecting a lagtime, from when winds shift to north, to when a
surge of wind buffets the waters. As a result we may not see
`Advisory` or `Cautionary` conditions until Monday night, which
may persist through Tuesday. The winds at 15-20 kt, with higher
gusts will build seas to 4-5 or 4-6 feet late Monday and
Tuesday, and as a result an SCA is certainly possible,
especially with mild water in place, aiding mixing of robust
boundary layer wind-speeds.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...None.
NC...None.
MARINE...None.
&&
$$
SYNOPSIS...DCH
NEAR TERM...DCH/DRH
SHORT TERM...RGZ
LONG TERM...MJC
AVIATION...DCH
Area Forecast Discussion
National Weather Service Lincoln IL
845 PM CDT Thu Oct 12 2017
.UPDATE...
Issued at 845 PM CDT Thu Oct 12 2017
The extensive low cloud deck remains over the area this evening
however the evening sounding shows it to be only a few hundred
feet thick at this time and satellite imagery shows a break in
cloud cover from Bloomington through Paris, and a back edge from
Quincy to Litchfield moving northeastward. Clearing behind the
back edge should result in patchy fog forming as radiational
cooling increases, and is depicted by several runs of the HRRR and
other models. Main update tonight, then is to add patchy fog to
southern and western portions of the forecast area. Otherwise,
lows in the lower 50s and light southerly winds look good for
tonight so have made no changes to temperatures and winds.
&&
.SHORT TERM...(This evening through Friday)
ISSUED AT 315 PM CDT Thu Oct 12 2017
Extensive deck of low stratus clouds continue to blanket IL/IN
and into eastern IA and northeast MO at mid afternoon. These
clouds trapped in a strong inversion under nearby high pressure
ridge to our northeast and light winds which will likely keep
skies cloudier into tonight. Could even be some patchy fog and
drizzle again overnight into early Fri morning especially in east
central IL where low clouds linger into Fri morning. Lows
overnight in the lower 50s, with some mid 50s in east central IL.
An increasing southerly flow on Friday should help break up low
clouds as skies become partly sunny and temperatures to warm up to
75-80F Fri afternoon. A frontal boundary setting up from central
KS ne to along the IA/IL border will initially keep chances of
convection nw of CWA during the day on Friday.
.LONG TERM...(Friday night through Thursday)
ISSUED AT 310 PM CDT Thu Oct 12 2017
The frontal boundary will get closer to our nw counties on Fri
night, bringing isolated convection to areas nw of the IL river
Fri night after sunset. Then a better chance of convection spread
se across areas north of I-72 overnight Fri night into Saturday,
with likely pops over the IL river valley. Lows friday night in
the upper 50s and lower 60s, coolest readings in eastern IL.
Unseasonably warm highs in the low to mid 80s on Saturday except
upper 70s over far northern CWA.
Surface low pressure to eject ne from central KS into west central
WI by sunset Saturday and deepen ne of the Great Lakes by sunrise
Sunday. This to push the cold front se across CWA during Sat
night. SPC day3 outlook has marginal risk of severe storms nw of
I-55 while slight risk is just west of Knox, Fulton and Schuyler
counties for Sat night. 12Z models are in better agreement with
quicker exit of cold front on Sunday and have trended pops
downward on Sunday morning with dry conditions over IL river
valley, likely pops in southeast IL early Sunday, then dry across
area by Sunday afternoon. Breezy nw winds bring in much cooler air
on Sunday with highs ranging from upper 50s and lower 60s over IL
river valley, and upper 60s in southeast IL. Seasonably cool lows
in the lower 40s Sunday and Monday night, with a few spots
reaching upper 30s north of I-72 sunday night as high pressure
settles into the area early next week.
A pleasant stretch of dry fall weather expected from Monday
through Thu night as high pressure stays nearby just southeast of
central IL. Seasonably cool highs in the lower to middle 60s
Monday to warm into the upper 60s to near 70F on Tue and low to
mid 70s Wed/Thu. The Climate Prediction Center (CPC) 8-14 day
outlook for Oct 20-26th continues 70% chance of above normal
temperatures and 40% chance of above normal precipitation for CWA.
So the growing season likely continues at least two more weeks
over central and southeast IL.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 638 PM CDT Thu Oct 12 2017
An extensive low cloud deck continues over central IL terminals
this evening with MVFR cigs 2000-3000 ft AGL predominant. Little
change is expected for several hours, but eventually a back edge
to cloud cover approaching from the southwest, currently visible
on satellite near the Mississippi River may arrive at KSPI-KDEC
after 06Z. Otherwise, very moist conditions will continue
overnight, leading to a good chance of MVFR vsby in fog developing
toward morning. Southerly flow on Friday should dissipate low
cloud cover through the morning, becoming SCT at 2000-4000 AGL.
Winds S 3-7 kts through the period.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...37
SHORT TERM...07
LONG TERM...07
AVIATION...37
Area Forecast Discussion...UPDATED
National Weather Service Marquette MI
905 PM EDT Thu Oct 12 2017
.SHORT TERM...(This evening through Friday)
Issued at 412 PM EDT THU OCT 12 2017
WV imagery and RAP analysis indicated a mid/upper level ridge from
the Gulf Coast to the ern Great Lakes and a trough over the nw CONUS
resulting in sw flow from the plains to the nrn Great Lakes. At the
surface, srly flow was strengthening over the upper MS valley and
nrn Great Lakes between a ridge over Quebec and nrn New England and
a cold front/trough from nrn Manitoba into the cntrl Dakotas. The
southerly winds have also brought in enough to low level moisture to
support an extensive area of low clouds over much of the region.
However, there was enough dry air over the ern cwa along with
additional daytime mixing for at least partial clearing over the
west half of Upper Michigan.
Tonight, Low level RH fcst and satellite trends suggest that clouds
will fill back into the area this evening. 925-900mb winds veering
from s to sw late and increasing to 30-35 knots will provide enough
low level lift to sustain the low clouds and possibly produce some
drizzle where srly upslope flow prevails and especially where
additional moistening occurs off of Lake Michigan, such as locations
from ISQ-ERY overnight.
Friday, A low pressure system is expected to lift ne through Hudson
Bay dragging a cold front across the Upper Michigan. Limited
moisture transport and weak forcing along and ahead of the cold
front may only result in a narrow band of isolated to scattered
light showers or sprinkles along the frontal passage.
.LONG TERM...(Friday night through Thursday)
Issued at 414 PM EDT THU OCT 12 2017
Only significant impacts in the long term are due to winds and waves
late Sat through late Sun.
Models have generally trended farther N and strong with a shortwave
and SFC low. For the most part there are two camps with the low
track/strength. The GFS and NAM are very similar in deepening the
low from around 1,000mb over SW WI 00Z Sun to mid 990s mb over S-
central Upper MI 06Z Sun to 986mb over far eastern Lake Superior 12-
15Z Sun, then quickly E into Quebec by 18Z Sun. The CMC and ECMWF
are weaker, only deepening to the mid 990s mb, and tracking farther
south over northern Lake Michigan and eastern Upper MI. Still plenty
of uncertainty with the exact track and strength so definitely favor
the blended guidance for winds. Current "middle of the road"
forecast has increasing E-NE winds Sat afternoon into early Sat
night, but nothing significant over land through that time. Winds
switch to N-NNW through the rest of the night while increasing up to
gusts up to 35mph in land areas near central and western Lake
Superior. Stronger NW winds and CAA then kick in Sun morning and
early afternoon, with shorelines gusts to 45-50mph east of
marquette, and gusts of 35-45mph elsewhere near Lake Superior. Winds
then decrease Sun evening and night. This will lead to waves in
excess of 8ft along all exposed Lake Superior shorelines in the CWA,
and in excess of 12ft east of Marquette. Last season we saw beach
erosion issues at 8ft and lakeshore flood issues around 14ft.
However, lake levels are 6 inches higher than this time last year,
so those thresholds may be lower. Of course, if the NAM/GFS
solutions verify, winds will be stronger, with potential for
shorelines gusts to 60mph. If the ECMWF/CMC verify, winds will be
weaker. Will continue to promote the impacts in the HWO/EHWO.
Only changes made to blended initialization was to pull winds to
downwind shore areas late Sat through late Sun. Otherwise, no
significant impacts expected and blends performed well.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 904 PM EDT THU OCT 12 2017
Advection of low-level moisture around high pressure to the east of
Upper Michigan has resulted in large area of stratus over the
region. MVFR conditions to IFR conditions are expected tonight
through the early morning hours Friday. There could also be some
light drizzle or sprinkles tonight into Friday morning. By late
Friday morning into early Friday afternoon, drier air will begin
to push in from the west allowing for steadily improving
conditions. Most sites will likely become VFR by late morning.
&&
.MARINE...(For the 4 PM Lake Superior forecast issuance)
Issued at 412 PM EDT THU OCT 12 2017
...NE to N gales possible on Lake Superior Sat night into Sun
afternoon...
A tightening pres gradient btwn high pres to the e and low pres
tracking ne to s central Canada will lead to an increase in srly
winds to generally 15-25kt across much of Lk Superior through
tonight. Winds will diminish slightly for Fri/Fri night as
weakening cold front associated with low pres tracking to Hudson
Bay moves across the Upper Lakes. New low pres will then lift ene
along the frontal boundary this weekend, passing across the Great
Lakes Sat night/Sun morning. Depending on the strength of the low
and cold air moving in behind the low, there may be a period of NE
to N gales Sat night into Sun morning over the west half of Lk
Superior and then Sun morning into mid Sun afternoon for the east
half of Lk Superior. Winds should be down to less than 20 kts by
Mon.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
None.
Lake Michigan...
None.
&&
$$
SHORT TERM...JLB
LONG TERM...Titus
AVIATION...KEC
MARINE...JLB
Area Forecast Discussion
National Weather Service San Francisco Bay Area
857 PM PDT Thu Oct 12 2017
.SYNOPSIS...Seasonably cool conditions will persist overnight into
Friday before a warming trend develops over the weekend and into
Monday. Another round of very dry conditions along with locally
strong and gusty offshore winds will return Friday night into
Saturday, especially over the North Bay Mountains and East Bay
Hills. A cooling trend will begin next Tuesday and rain chances
are forecast to develop late Wednesday into Thursday.
&&
.DISCUSSION...As of 8:55 PM PDT Thursday...Winds have eased across
our entire region and skies remain clear of clouds (although
widespread smoke persists). Lack of cloud cover along with light
winds will mean another cool night tonight with overnight lows
forecast to be mostly in the 40s, except mid to upper 30s in the
coolest interior valleys.
Friday will be a day much like today with near normal temperatures
and continued poor air quality in many areas due to smoke from the
North Bay Fires.
Surface high pressure is once again forecast to build to our north
and east on Friday night and Saturday morning, setting the stage
for another round of locally strong and gusty winds in the hills.
Winds are expected to be strongest in hills of the North and East
Bay where gusts of between 40 and 50 mph are possible across the
higher terrain. Based on the latest WRF, winds will be at their
strongest in the hills from about midnight Friday night through
midday Saturday. In addition, renewed drying will take place
across the region. These developments will create critical fire
weather conditions and so a new Red Flag Warning has been issued
for the North and East Bay Hills from 5 pm Friday through 11 pm
Saturday (see fire weather discussion below for more details).
Drier air by Saturday will result in warmer temperatures. The
warming trend will then continue into Sunday as an upper ridge
builds over California. High temperatures are expected to be in
the 80s in most areas on Sunday, even near the coast. These warm
conditions will carry over into Monday as well.
A cooling trend will commence on Tuesday as the upper ridge moves
off to our east and onshore flow develops. Rain is then possible
late Wednesday into Thursday as a broad upper trough develops
along the West Coast. Rain chances will mostly be confined to the
North Bay, although the 12Z ECMWF develops light rain as far south
as Monterey County.
&&
.AVIATION...as of 4:30 PM PDT Thursday...Haze and smoke
from the North Bay wildfires continue to be the challenge of the
forecast. North winds aloft have brought a smoke layer into the
SFO Bay Area where there have been reports of vsbys down to 4-5
miles and 3000 foot cigs. Smoke clouds and vsbys will improve
a little tonight as winds decrease and the airmass stabilizes.
Latest HRRR smoke model shows more smoke spreading south from the
fires on Friday as winds pick up again.
Vicinity of KSFO...Could see some periods of MVFR for cigs and
vsbys associated with haze and smoke from the North Bay Fires
through 04Z. Improving conditions expected after 04Z.
West to northwest winds to 16-18 kt through 04Z.
SFO Bridge Approach...Similar to KSFO.
Monterey Bay Terminals...Generally VFR with some smoke aloft
through Friday.
&&
.FIRE WEATHER...As of 8:30 PM PDT Thursday...Winds had decreased
across the fire district by late Thursday afternoon, even in the
hills. Winds are forecast to remain relatively light through much
of Friday. Thus, the Red Flag Warning was allowed to expire at 5
pm Thursday. However, dry offshore winds are forecast to increase
again late Friday and become locally strong and gusty by Friday
night and Saturday morning, especially in the North and East Bay
Hills where local gusts of up to 50 mph are likely. In addition,
relative humidity recoveries are expected to be very poor in the
hills on Friday night, and RH values are forecast to drop to
10-20 percent on Saturday. Due to these upcoming deteriorating
conditions, a new Red Flag Warning has been issued for the North
and East Bay Hills from 5 pm Friday through 11 pm Saturday. Winds
will be locally gusty elsewhere in the hills Friday night and
Saturday morning, but the magnitude of the winds outside the North
and East Bay are not expected to be sufficient to warrant a Red
Flag Warning. Winds will diminish in all areas Saturday afternoon
and evening, although locally gusty north to northeast winds will
persist in the North Bay Mountains through Saturday night.
Warmer temperatures, along with continued dry conditions, are
forecast for Sunday and Monday, but winds on those days are
expected to be light.
&&
.MARINE...as of 4:50 PM PDT Thursday...Breezy northwest to north
winds will continue overnight and into Friday as high pressure
resides over the eastern Pacific. Winds will begin to subside
overnight Friday and into the weekend. Strong winds this evening
and tonight will result in steep fresh swell across the waters.
Expect smoke from the North Bay wildfires to reduce visibilities
at times -- especially over the San Francisco Bay.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.Tngt...SCA...Pt Arena to Pt Reyes 0-10 nm
SCA...Pt Reyes to Pigeon Pt 0-10 nm
SCA...Pigeon Pt to Pt Pinos 0-10 nm
SCA...Pt Pinos to Pt Piedras Blancas 0-10 nm
SCA...Pt Arena to Pigeon Pt 10-60 nm
SCA...Pigeon Pt to Pt Piedras Blancas 10-60 nm
SCA...Mry Bay until 9 PM
&&
$$
PUBLIC FORECAST: Dykema
AVIATION: W Pi
MARINE: Rowe
FIRE WEATHER: Dykema
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Area Forecast Discussion
National Weather Service Spokane WA
504 PM PDT Thu Oct 12 2017
.SYNOPSIS...
Cooler and showery weather is expected for the rest of the work
week. Snow will fall in the mountains and at elevations as low as
3000 feet. A slow warming trend and drier weather will arrive for
the weekend and persist through at least Monday night. Much wetter
weather is expected to arrive by Tuesday and persist through much
of next week.
&&
.DISCUSSION...
Tonight through Friday night...Satellite imagery shows a cold
upper trough over the region with a mid level wave over the WA
Cascades tracking towards SE Washington this afternoon. Models are
struggling with the details of this wave tonight with varying
placements of heavier qpf but most solutions support the 12z ECMWF.
which as of 18z had the best handle on the intensity and
placement of this wave. The ECMWF shows a broad swath of light to
locally moderate precipitation with the initial wave as it tracks
across Eastern WA/N Idaho this evening followed by moist and
unstable westerly flow into the palouse, Central Panhandle
Mountains, and Blue Mountains overnight into Friday morning. The
ECMWF places 0.75-1.00 inch of qpf in this area. The latest 19z
HRRR run agrees with this idea...with a band of moderate to heavy
showers in the form of valley rain and mountain snow over Benewah,
Latah, and southern Shoshone counties overnight into Friday
morning. Snow accumulations in these areas will range from 3 to 6
inches above 3000 feet...but its possible the mountainous terrain
above 4000 feet around Clarkia and Deary could pick up 6 to 11
inches where upslope will be maximized. Snow levels may briefly
lower down to 2500 feet where the band of heavier showers sets
up. With the best lift passing over SE WA into the Central
Panhandle Mountains...snow amounts don`t look as high for the
northern mountains with 2 to 4 inches expected above 4000 feet
with up to 2 inches possible between 3-4k feet. Winter weather
advisories remain in place for several mountain zones.
Showers will linger into Friday afternoon before coming to an end
Friday night as drier air moves in from the northwest. This dry
air will allow for chilly overnight lows...especially the northern
valleys where a hard freeze is expected with lows in the upper
teens to mid 20s. JW
Saturday through Monday...Confidence is quite high that the
unusually cold and unstable upper level low is expected to exit
the region at the beginning of this period. This will bring dry
weather to the entire region with the exception of a small chance
of showers early Saturday near the Idaho/Montana border. The main
forecast challenge during this period will be how widespread will
valley fog become and if it does form how persistent will it be.
Given that it`s still October, we don`t think it will be too
widespread and it should readily burn off each day. Based on the
expected precipitation during the next day or so, we expect to see
most of the fog to form over NE Washington and the Idaho
Panhandle Valleys. Temperatures will rebound from their current
readings with highs in the 50s to middle 60s. Meanwhile lows will
slowly moderate with widespread freezing temps on Saturday night
climbing into the 30s to lower 40s for Sunday and Monday nights.
Tuesday through Thursday...Models are in agreement that the dry
ridge will break down via two distinct disturbances. The first
comes through as a cold front on late Tuesday. This is a rather
progressive feature and should not produce much precipitation.
Rather it should produce a brief breezy period with most of its
precipitation expected near the Cascade Crest and the Idaho
Panhandle. The front will likely arrive too late to bring much
cooling to the region, except perhaps near the Cascades. The
second system is the much more dynamic of the two features as this
one looks like it will be accompanied by an atmospheric river.
Timing from this is less certain as the GFS delivers precipitation
by Wednesday morning, meanwhile the EC and Canadian models hold
off until Wednesday night. We hedged the forecast toward the
latter solutions, but suffice it to say all solutions would
support the potential for widespread moderate precipitation. Since
this is associated with an atmospheric river, snow levels should
be considerably higher than what we are dealing with now. Looks
like most of the snow will begin at elevations of 6000 feet or
higher followed by the threat of showers as low as 4000 feet
beyond this period. fx
&&
.AVIATION...
00Z TAFS: A weather disturbance will spread mountain snow and
valley rain into the region tonight. MVFR/IFR ceilings and some
brief LIFR conditions will be common over NE Washington, N Idaho,
and the palouse through 18Z Friday. The potential exists for snow
to mix with rain in KCOE aft 10Z. Also downslope flow off the
Blue Mountains into KLWS should keep CIGS VFR. -RA will end aft
12-15Z but showers around the region will continue...mainly in
the mountains...but could impact the eastern TAF locations.
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 35 46 31 48 33 54 / 90 60 20 0 0 0
Coeur d`Alene 35 45 30 48 32 54 / 90 70 20 10 0 0
Pullman 35 45 32 49 34 56 / 100 80 20 0 0 0
Lewiston 40 52 35 56 37 62 / 80 60 20 0 0 0
Colville 35 49 23 50 27 54 / 60 50 20 0 0 0
Sandpoint 34 44 28 45 26 51 / 90 80 40 10 10 10
Kellogg 33 41 29 43 30 51 / 90 90 40 10 10 10
Moses Lake 37 55 27 56 32 60 / 60 20 0 0 0 0
Wenatchee 36 52 32 56 36 60 / 40 20 0 0 0 0
Omak 35 54 27 55 30 59 / 40 20 10 0 10 0
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Winter Weather Advisory until 11 AM PDT Friday above 4000 feet
for Northern Panhandle.
Winter Weather Advisory until 11 AM PDT Friday above 3000 feet
for Central Panhandle Mountains.
WA...Winter Weather Advisory until 11 AM PDT Friday above 4000 feet
for Northeast Blue Mountains-Northeast Mountains-Okanogan
Highlands.
&&
$$
Area Forecast Discussion
National Weather Service Paducah KY
713 PM CDT Thu Oct 12 2017
.UPDATE...
Issued at 713 PM CDT Thu Oct 12 2017
Fog imagery shows the persistent low cloud cover is nearly
stationary across the area, with a light ESE trajectory seen from
the surface up through HRRR initialized 925mb data. The NAM and
RAP/HRRR continue to be the best guidance available. They suggest
our current cloud forecast is too quick with the clearing.
Satellite confirms this to some extent. Will raise lows a few
degrees east of an I-57, I-24, Highway 45 line. Our gridded
forecast for cloud cover/clearing will be based close to the
NAM/HRRR. More weight to the NAM. Left the fog mention over SEMO
counties where clearing will hold. There may be some light fog
elsewhere, especially close to the clearing line.
CN
&&
.SHORT TERM...(Tonight through Saturday night)
Issued at 205 PM CDT Thu Oct 12 2017
Main forecast challenges will be the departure of the opaque cloud
cover from the WFO PAH forecast area and the timing of the
precipitation associated with the approach of the next cold front
into the area late Saturday night (early Sunday morning).
Isentropic lift and forcing remain marginal across the area,
especially east of the surface ridge axis which extends from the
Mississippi River northeast into Southwest Indiana. Even at 1 pm
CDT, cloud thickness over parts of southern IL and parts of
Southwest Indiana remain in excess of 1500 ft.
Warm air advection tonight and Friday should continue to erode the
cloud layer from above and below as the ridge axis slowly moves
east. Given the weak advection, there may still be some
cloudiness, albeit not 100 percent coverage, across the west
Kentucky Pennyrile region and southwest Indiana, this evening.
Where skies remain clear over southeast Missouri, could see some
localized fog development overnight, even with very weak warm
advection (most significant at and above the boundary layer).
The influence of the ridge axis will likely yield to some diurnal
cumulus cloud development early on Friday, before clearing out
for the remainder of the day.
Utilized the short range ensemble guidance (SREF) to address the
timing, coverage, and intensity of rain late Saturday along and
ahead of the approaching cold front. Limited instability aloft
mitigated any differential mention of thunderstorms through
Saturday night.
.LONG TERM...(Sunday through Thursday)
Issued at 205 PM CDT Thu Oct 12 2017
The only real weather maker in the long term period will be a
frontal passage early Sunday which will bring our only chance for
rain.
Models have definitely sped up the timing of this front and
associated rainfall. At 12Z Sunday, the NAM/GFS show the actual cold
front in our far eastern counties with most of the precipitation
post frontal. The ECMWF and Canadian indicate the front a bit
further west at that time.
The speed difference between models of the aforementioned front does
not seem to have much affect on the forecast, as the best chances
for rain for our area will still come between 12Z-18Z Sunday.
Whatever precipitation is left Sunday afternoon, will be across
parts of west KY. Not sure how much thunder will be involved as most
of the instability will be tied to the front and directly behind the
front.
Will need to make changes to our going POP forecast however
in order account for the more rapid arrival and departure of the
precipitation. Will likely have to take rain chances out for Sunday
night. Temperatures on Sunday will be tricky depending on how fast
the cooler air filters into the area. We may be dealing with a non
diurnal trend. Model guidance is suggesting falling temperatures
through the morning hours so our high will likely be first thing in
the morning.
By late Sunday afternoon, a large 1028-1030mb surface high will be
situated over Kansas and Oklahoma. This sfc high will start
migrating eastward Sunday night and into Monday, really helping to
dry things out locally.
The center of this sfc high pressure system will be overhead by late
Monday night into Tuesday morning. With clear skies and calm winds,
Monday night into Tuesday morning should be our coldest, with lows
dropping into the lower to mid 40s. High pressure will dominate for
the rest of the week, which will aid in keeping any chances for
precipitation at bay. Temperatures will remain in the 70s for highs
and upper 40s to lower 50s for lows from Tuesday and beyond.
&&
.AVIATION...
Issued at 640 PM CDT Thu Oct 12 2017
The back edge of a widespread area of MVFR cigs was nearly
stationary near the Mississippi River early this evening. Low level
winds are so weak that not much movement is expected through the
early morning hours. MVFR cigs are forecast to persist at most taf
sites through at least mid-morning Friday. The exception is kcgi,
which was right on the clearing line early this evening. The
clearing line should budge just a little east of kcgi this evening.
Some fog is likely at kcgi after skies clear, with IFR vsbys likely
at times early in the morning.
As winds become southeast on Friday, VFR conditions are expected at
all sites as the clouds move out.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...None.
MO...None.
IN...None.
KY...None.
&&
$$
SHORT TERM...Smith
LONG TERM...CW
AVIATION...MY
Area Forecast Discussion
National Weather Service Raleigh NC
1000 PM EDT Thu Oct 12 2017
.SYNOPSIS...
A backdoor cold front will settle south of North Carolina tonight.
Behind the front, a cool high pressure area will build down the East
Coast through Saturday.
&&
.NEAR TERM /THROUGH TONIGHT/...
As of 1000 PM Thursday...
The backdoor cold front has pushed south of our region into SC
this evening. A line of showers and thunderstorms was preceding the
front, but well south of Fayetteville and moving south. CAA has
begun in earnest across central NC with temperatures now in the
lower 60s across the northern NC Piedmont. That combined with the NE
breeze at 8-15 mph was creating "natures air conditioning"
considering the previous 5 days of record warm and moist conditions.
Low overcast was observed over most of central NC with the overcast
spreading SW with time. Other than patchy drizzle, there have been a
few showers over the western Piedmont back into the Mountains, but
mostly light and scattered thus far.
Low level moist isentropic upglide is forecast to increase and
deepen overnight with an increase in the areas of light rain and
drizzle, especially over the western Piedmont. The latest HRRR
indicates scattered showers over the western Piedmont as well
through daybreak. QPF of less than 0.25 is expected in the west,
with only trace or 0.01 in the east with the drizzle.
Lows generally 55-60 NE ranging to 65 south.
&&
.SHORT TERM /FRIDAY AND FRIDAY NIGHT/...
As of 315 PM Thursday...
The damming wedge will hold in place through central NC through Fri
and Fri night, with low level stability reinforced by an anticyclone
just above the surface-based stable pool extending through the mid
levels. Heating will result in some lifting and breaks in the
stratus through the day across the southern and eastern sections,
along the shallower edges of the wedging ridge. Isentropic upglide
wanes during the morning, leaving just small chances of patchy light
rain through the day, mainly in the NW. Low level thicknesses will
still be slightly above normal, but with the cloudiness, highs
should be closer to normal, from around 70 N to upper 70s to near 80
far SE. Shallow fog is possible Fri night, as a lack of clouds aloft
allows for good radiative cooling down to the dewpoint within light
winds. Lows 59-65. -GIH
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
As of 245 PM Thursday...
Wedge airmass will be cut off from reinforcing cool air advection as
the surface ridge progresses offshore well east of the Mid Atlantic.
As such, the cool air will be undergoing modest erosion from the top
down, and the south and east may break out during the afternoon.
Deeper cool and moist axis across the western Piedmont will likely
hold the cloudiness in all day, with highs stalling in the mid 70s
in the northwest while the southeast reaches low to possibly mid
80s. Return flow will be underway as the cooler airmass will be
scoured and mixed out by Sunday, with highs rebounding to the low
and mid 80s.
Latest GFS is ~6 hours faster bringing our long awaited cold front
across the mountains Sunday night. This timing difference won`t be a
huge concern, as the front will be moving quickly and be strongly
sheared, which will just about eliminate any Gulf connection to
provide additional moisture advection. In addition, instability will
be very low as well due to the fronts moving through early in the
day, so potential for strong convection will be very limited and
confined to the southeast in the early afternoon. Cold air advection
will be underway early as well, with highs barely reaching 70 in the
northwest, with some very low 80s southeast.
Cool high pressure settles in Monday night through midweek...with
highs Tuesday and Wednesday mostly in the mid 60s north to very low
70s south...warming a bit by late week to the low and mid 70s as the
airmass modifies. Mins will be downright chilly....falling mostly
to the mid and upper 40s each morning from Tuesday through Thursday.
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
As of 810 PM Thursday...
24 Hour TAF Period: Adverse aviation conditions are expected to
continue through the 24 hour TAF period, as a CAD airmass
encompasses all of central NC. This will lead to east to
northeasterly low level across the area with lowering cigs
overnight. Expect cigs will fall in to the IFR category later this
evening/into early Friday morning, with even some LIFR cigs early
Friday/Friday morning. Patchy drizzle and light rain will also be
possible tonight into Friday, with the best chance at KGSO/KINT.
Cigs will slowly increase some on Friday, though likely remaining
IFR at KGSO/KINT and MVFR at KRDU. Cigs may briefly rise late in the
day at KFAY AND KRWI to VFR.
Outlook: IFR/LIFR conditions should return for Fri evening through
much of Sat morning. Slow improvement of cigs through the MVFR
category to low-end VFR is expected Sat afternoon. Sub-VFR
conditions may return late Sat night through daybreak Sun but won`t
be as thick or long-lasting as tonight`s poor conditions. VFR
conditions are expected Sun, but a strong cold front pushing through
Sun evening will bring sub-VFR conditions Sun night through early
Mon. Improvement to VFR is expected during Mon, with clearing skies
Tue.
&&
.CLIMATE...
Record high minimum temps for October 12:
GSO: 64 in 2002
RDU: 68 in 1990
FAY: 68 in 1990
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
None.
$$
SYNOPSIS...Hartfield
NEAR TERM...Badgett
SHORT TERM...Hartfield
LONG TERM...mlm
AVIATION...BSD/Hartfield
CLIMATE...MWS
Area Forecast Discussion...Updated
National Weather Service Tucson AZ
420 PM MST Thu Oct 12 2017
.SYNOPSIS...Expect isolated showers and thunderstorms southeast of
Tucson early this evening. Dry conditions with above normal daytime
temperatures will then prevail into the middle of next week.
&&
.UPDATE...KEMX WSR-88D detected isolated 40-50 dBZ echoes across
portions of Cochise County at this time, and somewhat stronger
echoes were detected near the International border adjacent Cochise
County. Although a dry near-surface regime exists such that
measurable rainfall chances are quite low, a few lightning strikes
have been detected, particularly just east of Coronado National
Memorial. Based on radar trends as well as a couple of recent HRRR
solutions, have opted to insert isolated showers and thunderstorms
through 13/03Z (8 pm MST) generally southeast of a San Simon-
Cochise-Sierra Vista arc.
&&
.DISCUSSION...Latest visible satellite imagery depicts clear skies
west of Tucson with mostly clear to partly cloudy skies from Tucson
eastward under a cumulus field with a few build-ups. This matches up
nicely with the moisture fields across the area as satellite derived
PWAT values are 0.75" to 1.00" east of Tucson with lesser values to
the west. KEMX radar imagery is showing just a few weak echoes
across Cochise County. Will keep PoPs below 10 percent but a
sprinkle or two can`t be completely ruled out this afternoon into
early this evening.
In the broader picture, the forecast area lies between an expansive
anticyclone aloft across the southeast and Gulf Coast states and
troughing across the Pacific Northwest with southwesterly flow aloft
currently in place. Limited moisture will tend to hang on to the far
southeast portions of the state into Friday but once again not
really expecting much more than a few build-ups. Thereafter, even
with the storm track well to our north, a shortwave pushing across
the northern Rockies will push in some drier air area-wide by
Saturday with westerly flow. This theme of westerly flow aloft will
continue through Wednesday as we remain between high pressure aloft
across northern Mexico and the storm track across the northern tier
of states. A weak southern stream system is progged to move into the
region on Thursday but there are some timing and amplitude
differences. Have introduced slight chance PoPs on Thursday for
northern areas.
Otherwise, an easterly push with a back door cold front will move in
Sunday with some breezes and a few degrees of cooling into early
next week. Locales from Tucson westward will continue with well
above normal temperatures for mid October.
&&
.AVIATION...Valid thru 14/00Z.
Isolated -TSRA/-SHRA generally southeast of a San Simon-KFHU line
through 13/03Z. Otherwise, scattered to broken clouds at 8k-12k ft
AGL KTUS vicinity eastward into this evening becoming clear skies to
few clouds above 10k ft AGL area-wide later tonight into Friday
morning. Scattered to broken clouds at 8k-12k ft AGL mainly east of
KTUS Friday afternon. Surface wind wly/nwly 10-18 kts early this
evening becoming variable in direction less than 12 kts after 03Z
and continuing into Friday. Aviation discussion not updated for TAF
amendments.
&&
.FIRE WEATHER...Isolated showers and thunderstorms early this
evening across the southern portion of Fire Zone 152. Otherwise, dry
conditions into the middle of next week. Expect terrain driven winds
generally less than 15 mph, although some gusty east to southeast
winds may occur east of Tucson on Sunday.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...None.
&&
$$
Francis
DISCUSSION...GL
AVIATION/FIRE WEATHER...JKP
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