Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 11/18/16
Area Forecast Discussion
National Weather Service Charleston SC
956 PM EST Thu Nov 17 2016
.SYNOPSIS...
High pressure will prevail through late week. A dry cold front will
advance through the area on Saturday, followed by much cooler high
pressure through the middle of next week. Another cold front will
move through next Thursday.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
Temperatures continue to fall a bit quicker than expected. Made
further adjustments to hourly temperatures and overnight lows in
a few locations to account for this. Also introduced "areas of
fog" in the Savannah-Moncks Corner corridor where both the H3R
and RAP are hitting the fog prospects the hardest. The rest of
the forecast is on track.
Thermal falls are beginning to accelerate this evening within a
decoupled boundary layer and prime radiational conditions are
expected to prevail once again. Opted to nudge temperatures down
a few degrees across the coastal corridor and introduce some
stronger mesoscale influences over some of the normally colder
areas such as the Francis Marion National Forest to account for
the expected radiational setup. Also nudged temperatures over
Lake Moultrie up by several degrees given trends noted at
Pinopolis over the past several mornings.
Conditions favor another night of shallow ground fog across the
area with the better fog parameters looking to align across
mainly the central and southern zones. Smoke generated by
wildfires burning over the Southern Appalachians and the
foothills of North Carolina will not be as much of an issue
tonight, but it will linger in many places as the nocturnal
inversion strengthens. A late afternoon MODIS image clearly
showed a large smoke plume in place across much of South
Carolina and Georgia, but it was certainly not as thick as
previous days given the more northerly steering trajectory.
The South Carolina DHEC has issued a CODE ORANGE Air Quality
Alert for Charleston and Beaufort Counties for Friday. As a
reminder, the Georgia Department of Natural Resources` Air
Protection Branch does not issue Air Quality Alerts for
Southeast Georgia.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/...
The large ridge will persist through Friday night before
shifting off the coast as a potent shortwave approaches.
Unseasonably warm temps expected Friday through Saturday, then a
cold front will sweep through late Saturday afternoon with much
colder air resulting. No rain expected with the front though
breezy conditions expected Saturday. By Sunday, high temps
will only peak in the upper 50s to lower 60s despite a full day
of sun. A decent gradient will produce 10-15 mph winds on
Sunday.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
Cold/dry high pressure will build across the region behind a cold
front departing well offshore Sunday night, bringing some of the
coldest temps so far this season. The main issue will be overnight
temps as cold air continues to advect into the region aloft while
sfc winds become light. At this time, Sunday night lows should
approach the low/mid 30s away from the coast with a few areas
potentially hitting the freezing mark well inland and north of I-16.
Given the setup, a freeze watch/warning could be needed. Cooler
conditions will persist into Monday with high temps peaking in the
upper 50s north to low/mid 60s south, but temps should be a few
degrees warmer Monday night, keeping temps slightly above freezing.
Temps will gradually recover into the middle of next week under a
zonal flow. In general, temps will peak into the mid/upper 60s
Tuesday, then upper 60s to lower 70s on Wednesday. Another dry cold
front should then approach the region on Thursday.
&&
.AVIATION /03Z FRIDAY THROUGH TUESDAY/...
VFR for much of the period, although shallow ground fog could
reduce vsbys to high-end MVFR at KSAV 09-12z. Smoke/haze will
continue to impact both terminals for Friday.
Extended Aviation Outlook...VFR conditions are expected at both
KCHS and KSAV terminals. Breezy Saturday/Sunday with a passing
cold front.
&&
.MARINE...
Tonight: Tranquil conditions expected with high pressure in
control. Could see some patchy smoke which could reduce
visibilities below 5 NM at times.
Friday through Tuesday: High pressure will dominate the coastal
waters through early Saturday with sub-advisory winds/seas. A
dry cold front will then move through the waters Saturday
evening with strong cold air advection and 25-35 kt low-level
winds resulting in Small Craft Advisory conditions across most
if not all of the waters. Conditions improve Monday into Tuesday
with high pressure settling over the waters.
&&
.TIDES/COASTAL FLOODING...
Minor salt water flooding is expected around the times of the
morning high tide Friday and potentially into Saturday until a
cold front sweeps offshore. Coastal Flood Advisories are likely.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...None.
SC...Air Quality Alert until midnight EST Friday night for SCZ048-
050.
MARINE...None.
&&
$$
Area Forecast Discussion
National Weather Service Cheyenne WY
410 PM MST Thu Nov 17 2016
.SHORT TERM...(This evening through Saturday Night)
Issued at 155 PM MST Thu Nov 17 2016
Upper low progressing east across central Colorado this afternoon
with snow expanding slowly across the CWA. Some enhanced banding
of snow seen on radar over far se Wy into the sw Panhandle...
looking associated with a small circulation center southwest of
Cheyenne. This will likely bring a period of more moderate snow to
the area through late this afternoon. Current hilites/snowfall
amounts look to be in good shape overall though some concern
about snow amounts over the northern Panhandle. Will not make any
changes at this time to the hilites.
The upper low over Colorado will turn northeast and accelerate
tonight while a surface low moves across Kansas into Iowa. This
will bring an end to the snow with only a few lingering flurries
expected after midnight. A cold surface high will settle into
Wyoming overnight with temps falling into the teens to lower
20s...with some single digits over western valleys. Friday will be
cool with clearing skies across the CWA as high pressure slides
across the area into the central and southern plains. Chilly again
Friday night with mainly clear skies and light winds. Dry and
warmer Saturday as upper ridging moves across the region.
.LONG TERM...(Sunday through Thursday)
Issued at 155 PM MST Thu Nov 17 2016
This discussion is abbreviated due to ongoing, high-impact weather
across the region. Mild and dry conditions will prevail for Sunday
with upper-level ridging in place. Medium range models are in good
agreement with the development of a more unsettled pattern on Mon/
Tue as a fast-moving shortwave tracks across the Great Basin. This
system will not be as strong as the current one, but does have the
potential to produce minor snowfall accumulations depending on the
timing of the cold front. Quiet weather is likely for Wednesday as
the CWA will be in between weather systems.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 409 PM MST Thu Nov 17 2016
IFR/LIFR conditions to continue this evening for the Nebraska
Panhandle airports as well as KCYS. Used latest HRRR guidance with
improving conditions from west to east through the evening and
overnight hours.
&&
.FIRE WEATHER...
Issued at 155 PM MST Thu Nov 17 2016
Fire weather concerns pretty much nil through the weekend with
cool to mild temperatures expected. Snow across the area into this
evening will end overnight then mainly dry through the weekend.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...Winter Weather Advisory until 8 PM MST this evening for
WYZ101>119.
NE...Winter Storm Warning until midnight MST tonight for NEZ002-095.
Winter Weather Advisory until midnight MST tonight for NEZ003-
019>021-096.
&&
$$
SHORT TERM...RE
LONG TERM...CLH
AVIATION...GCC
FIRE WEATHER...RE
Area Forecast Discussion
National Weather Service Lincoln IL
839 PM CST Thu Nov 17 2016
.UPDATE...
Issued at 838 PM CST Thu Nov 17 2016
Winds are starting to settle down a bit across the northwest CWA,
but some gusts of 20-30 mph continue in the Bloomington-
Springfield areas, although this will diminish a bit as well. High
clouds continue to stream northeast across most of the forecast
area, and this general trend will continue through the night.
Temperatures have been staying up a bit than earlier expected due
to the stronger winds, so low temperatures have been nudged up a
bit in a few areas, mainly west of I-55.
Main low pressure associated with the storm system to our west has
reached south central Kansas early this evening, with a secondary
low over central Iowa. Early look at the 00Z NAM and the hourly
HRRR/RAP indicates the main low will continue to ride northeast
along the boundary into central Iowa by sunrise. Associated cold
front should move into west central Illinois by late morning and
will be near the Wabash River by 6 pm. General trend of the
earlier forecast still looks good, and only some minor tweaks were
done to Friday PoP`s to reflect the latest timing.
&&
.SHORT TERM...(This evening through Friday)
ISSUED AT 248 PM CST Thu Nov 17 2016
A 999 mb low pressure over west central Iowa has a cold front
extending sw through central KS to deepening 994 mb low pressure
near the OK panhandle and NM border. Breezy SSW winds of 10-20 mph
and gusts of 25-33 mph along with filtered sunshine through thin
cirrus clouds was giving unseasonably mild temps in the 70s.
Springfield was 79F and already broke their record high of 75F.
Flora was also 79F and Effingham was 78F and some more record highs
will likely be set this afternoon.
Dry conditions should continue tonight as mid/high clouds increase
from the west. A mild night ahead with south winds 10-20 mph, with
lows of 53-59F, mildest over western IL where more cloud cover
expected tonight. The models take strong low pressure ne from OK
panhandle into central Iowa by 12Z/6 am Friday and then to western
upper MI by 6 pm Friday. This will push a strong cold front east
into the IL river valley by 18Z/noon Friday and pass east of IL by 6
pm Fri. Expect a band of showers and thunderstorms ahead of this
front to spread eastward toward I-57 by late Fri morning and across
eastern IL early Fri afternoon. Have highest pops Friday afternoon
across central and eastern IL. SPC day2 has general risk of
thunderstorms east of the IL river on Friday while marginal risk of
severe storms with high winds was over AR and southeast MO. Highs
Fri to range from mid 60s over IL river valley to lower 70s near the
Wabash river. Temperatures to fall behind the cold front during
Friday afternoon as fairly strong SSW winds 15-25 mph and gusts of
30-40 mph turn westerly during Fri afternoon. Mercury levels to fall
into the upper 40s over IL river valley by 6 pm Fri and lower 60s
near the Wabash river.
.LONG TERM...(Friday night through Thursday)
ISSUED AT 248 PM CST Thu Nov 17 2016
Gusty northwest winds will be ongoing across central and southeast
Illinois to start the period. These winds will be ushering much
colder temperatures into the region, with temperatures for the
weekend expected to be colder than normal for a change. Wrap around
moisture on the back side of the departing storm system will brush
far northern portions of the forecast area Friday night into
Saturday, possibly producing very light rain or snow showers.
However, forecast soundings suggests the low level moist layer is
will be pretty shallow, so if it does precipitate, it will not
amount to much.
Upper-level heights rise, and low-level flow turns southerly, to
start the next work week. This scenario is supportive of dry weather
and temperatures trending back to normal or above to start the week.
A system will stream in off the Pacific, reaching the Midwest by
Tuesday into Wednesday. This system will bring the next chance of
precipitation to the area, but current trends indicate it will be
warm enough for all rain. The system will be east of the area by
Thanksgiving, with dry weather and seasonable temperatures returning.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 536 PM CST Thu Nov 17 2016
Main concern in the short term is LLWS. Current upper air sounding
from our office showing winds of 180/43kt at just 1500 feet off
the ground, and latest RAP model guidance shows the low level jet
persisting through the night, with the core of it shifting a bit
eastward before diminishing a tad around 09Z. Later in the
morning, the surface winds will be increasing as a strong low
pressure system lifts northeast across Iowa, with gusts to around
30 knots likely by mid morning. A trailing cold front will advance
eastward across Illinois, crossing the central Illinois TAF sites
between about 17-22Z, bringing showers and scattered storms, as
well as a few hours of MVFR or low VFR ceilings. Once the front
passes, ceilings will rapidly increase late in the period, but the
strong winds will persist out of a westerly direction.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Geelhart
SHORT TERM...07
LONG TERM...Bak
AVIATION...Geelhart
Area Forecast Discussion...UPDATED
National Weather Service North Platte NE
541 PM CST Thu Nov 17 2016
.SYNOPSIS...
Issued at 340 PM CST Thu Nov 17 2016
A vigorous H5 trough of low pressure continues to track across
southern Colorado this afternoon. Instability in association with
this system has increased this afternoon along the front range of
Colorado as abundant convective cloudiness has developed. This
instability has spread north into the Nebraska panhandle where vis
satellite imagery has some convective clouds as well. At the
surface, low pressure was centered near Omaha with a second
developing low over southeastern Colorado. A cold front extended
east of the second low across southwestern Kansas, northeast into
southeastern Nebraska. As of midday temperatures across Nebraska
ranged from 31 at Alliance to 70 at Falls City. Light snow has begun
to develop across the northern panhandle over the past couple of
hours. Highway cameras have indicated some light accumulations
across northern Sheridan county around Hay Springs. Across western
and north central Nebraska under cloudy skies, 3 PM CST temperatures
ranged from 37 at Valentine, Thedford and Ogallala, to 43 at
O`Neill.
&&
.SHORT TERM...(This evening through Friday)
Issued at 340 PM CST Thu Nov 17 2016
Tonight and Friday...Snow accumulations and impacts
from the approaching winter storm are the main forecast concern over
the next 24 hours. Through Friday, a strong upper level low and
associated surface low will track from eastern Colorado into the
upper Mississippi valley. Accumulating snows and strong winds will
be the main impacts to the forecast area over the next 24 hours. The
latest NAM12 solution this morning has now trended further east
toward the GFS solution with its heaviest area of snow across the
eastern portion of the forecast area. Further support for this shift
lies with the latest RAP and HRRR solutions as well. Also, the
models do agree on a strong potential for convective precipitation
ie. thunder snow which could lead to some better than 1 inch per
hour snow accumulations. That being said, with the more eastward
shift in the models this morning, went ahead and added Lincoln and
Custer counties to the winter storm warning and increased snow
accumulations. For the remainder of the forecast area, felt snow
accumulations were a tad light and increased them across the board.
This was a result of a earlier change over from rain to snow
forecast for tonight. Temperatures today have remained steady in the
30s to around 40, not the 40s to near 50 as was forecasted
overnight. These cooler temps should facilitate an earlier change
over from rain to snow, thus the higher amounts. With the increases
in accumulations, snow totals with this system will range from
around 2 inches in the far southwest and southeastern panhandle to
around 7 inches in the northeastern forecast area. For most of the
forecast area, these amounts are sub warning criteria, however strong
winds behind the exiting system are a major concern, as well as the
blowing and drifting snow threat. Also, this is the first major
winter storm of the season, so feel warning headlines remain
justified here.
Snow will taper off to flurries from southwest to northeast
overnight tonight through mid morning Friday. Very strong
northwesterly winds will impact the forecast area with the strongest
winds expected from central into north central Nebraska and points
east. In these areas, bufkit soundings indicate a strong potential
for 50+ MPH wind gusts centered around 12z Friday morning. This will
produce considerable blowing and drifting snow which will make for a
bad commute Friday morning. Winds will begin to diminish Friday
afternoon with the blowing snow threat winding down Friday
afternoon. Highs Friday will be cool as readings struggle to get out
of the lower 30s.
.LONG TERM...(Friday night through Thursday)
Issued at 340 PM CST Thu Nov 17 2016
Friday night will be cold as a fresh snow pack will combine with
clear skies and light winds. Coldest night this fall for all with
teens and even some single digits possible in favored cold spots.
Although a chilly start to the day on Saturday a nice rebound of
temps as ridging builds in for the weekend. Highs still a little
below normal as the snow cover dampens the warming, although areas
that see some snow free ground may be a little warmer than going
forecast.
Warming trend continues on Sunday and Monday with highs in the 40s
and 50s, coolest across north central Neb as cold air recycles into
the region.
Next system ejects across the Rockies late Monday into Tuesday. A
much warmer system than current system with precip type now looking
at more rain than snow, although that which falls overnight could be
a mix.
This is another short lived system with a rebounding ridge for Wed
into the Thanksgiving holiday. Highs in the 50s with lows in the 20s
to around freezing.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 541 PM CST Thu Nov 17 2016
IFR/LIFR in snow and low CIGS are expected to become widespread
this evening from west to east.
Flight conditions will improve to IFR/MVFR in snow and low cigs
from west to east around 09z.
MVFR/VFR/local IFR cigs are expected to spread from west to east
around 15z.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory until 6 PM CST /5 PM MST/ Friday for
NEZ022-056>058-069>071.
Winter Storm Warning until 6 PM CST /5 PM MST/ Friday for
NEZ004>010-023>029-035>038-059-094.
&&
$$
SYNOPSIS...Buttler
SHORT TERM...Buttler
LONG TERM...Masek
AVIATION...CDC
Area Forecast Discussion...Updated
National Weather Service Saint Louis MO
939 PM CST Thu Nov 17 2016
.UPDATE...
Issued at 938 PM CST Thu Nov 17 2016
Have updated forecast to delay onset of showers and thunderstorms
by a few hours early tomorrow. Latest runs of the RAP is not
showing the low level moisture convergence moving into central
Missouri until mid morning. This shows up well in the latest runs
of the HRRR which keeps most of the showers and thunderstorms
moving into the area after 12Z. Still looks like a mild night with
the clouds and the wind staying up. Only made minor adjustments to
the lows.
Britt
&&
.SHORT TERM... (Through Late Friday Afternoon)
Issued at 252 PM CST Thu Nov 17 2016
The synoptic pattern early this afternoon features an amplified
ridge across much of the eastern CONUS, with an upstream deep trough
digging into the central and southern Plains. This trough will be
the main focus of the short term period, as it will move into the
Midwest by Friday evening, driving a strong cold front through the
region as it does.
Lee cyclogenesis is occurring late this afternoon across portions of
western Colorado and eastern Nebraska, all in response of the
aforementioned deep trough ejecting out into the Plains. This
cyclogenesis will enhance the surface pressure gradient over the
region tonight, keeping winds up around 10-15 mph with a few higher
gusts overnight. These winds in combination with increasing cloud
cover will keep temperatures very mild tonight, in the upper 50s to
low 60s.
The surface low will slide northeast into Wisconsin tomorrow, with a
trailing cold front quickly pushing through MO and IL by late Friday
afternoon. Guidance has come into fairly good agreement on the
timing of the front, entering central MO Friday morning, reaching
the St. Louis metro near midday, and pushing out of the CWA
completely by early Friday evening. Ahead of this boundary, low-
level moisture will attempt to advect northeastward with dewpoints
expected to reach the upper 50s. While not great, this surface
moisture coupled with the incoming steep lapse rates aloft should be
able to push SBCAPEs to near 500 J/kg across southeast MO and into
southwest IL.
Initially Friday morning, the precip along the front will not be
very widespread. However, precipitation should increase both in
coverage and intensity as the boundary pushes into eastern
MO/western IL. This uptick in coverage/intensity will be due to the
upper-level divergence of the approaching right jet exit region,
along with a strong PV anomaly rotating through the base of the
trough, enhancing upper-level ascent as the trough takes on more of
a neutral tilt. This strong upper-level forcing coupled with the
slab-like ascent along the front should lead to a linear storm mode.
Flow just off the surface will be swift (50 knots around 5,000
feet), so if enough instability is realized, then storms may be
strong/deep enough to mix down a few strong/damaging wind gusts
across southeast MO and perhaps into southwest IL. The latest data
suggests that SPC`s Marginal Risk may need to be nudged a but
northeastward with the next update to account for this potential.
Otherwise, temperatures tomorrow will be tricky and will all depend
on the timing of the front. Have gone with upper 50s across central
MO where the front will move through in the morning, with low 70s
over western IL where the front will not move through until the
afternoon.
KD
.LONG TERM... (Friday Night through Next Thursday)
Issued at 252 PM CST Thu Nov 17 2016
(Friday Night through Sunday)
Not a lot has changed in the past 12 hours regarding mdl guidance.
While precip shud be out of the CWA by 00z Sat, have kept some low
PoPs across ern portions of the CWA to account for any lingering
stratiform precip. That said, by 03z, all precip shud be out of the
region with the cdfnt near the IN/OH border and into ern KY. The
remainder of this period remains dry as a sfc ridge builds into the
region.
Fri night continues to be well mixed across the region with good
momentum transport as the low pulls ewd. Have continued with gusts
in the 30+ kts range. Currently expect winds to remain below adv
criteria, but will need to be monitored.
As for temps, trended twd the warmer guidance for Fri night across
the ern and nrn portions of the CWA where more mixing will persist
overnight. Trended aob the coolest guidance for wrn and srn areas.
These areas may still be too warm if winds diminish more than
currently suggested, especially in low lying sheltered areas.
Trended warmer for all but ern areas on Sat. The ern counties shud
see more clouds, longer into the day.
Sat night still appears to be the coolest night in the forecast
period. The sfc ridge shud be over the area with light winds and a
clear sky. In general, trended aob the cooler guidance.
(Monday - Wednesday)
Main focus for the extd will be the next system approaching the area
on Tues and Wed after a brief warmup on Mon and Tues. Areas with
best chances for precip are nrn portions of the CWA. However, much
of the region shud see some light precip. Have kept mention of TS
out of the forecast for now.
Tilly
&&
.AVIATION... (For the 00z TAFs through 00z Friday Evening)
Issued at 550 PM CST Thu Nov 17 2016
Low level jet will set up between 1000-2000ft AGL causing LLWS at
all of the terminals through mid morning. The LLWS will end by mid
morning. Scattered showers and thunderstorms will develop ahead
of a cold front that will move across the area on from west to
east on Friday which will cause winds to shift from south to west.
There will be some areas of MVFR ceilings and visibilities with
the showers and thunderstorms. Do not have enough confidence to go
with move than just VCTS at this point.
SPECIFICS FOR KSTL:
Low level jet will cause LLWS overnight. Then there will be
scattered showers and thunderstorms that will move through the
area midday on Friday that could affect the terminal. Do not have
enough confidence to go with more than just VCTS at this point.
There could be some MVFR ceilings and visibilities with any
showers and thunderstorms that do affect the terminal. A cold
front will pass through the terminal early in the afternoon that
will winds to shift from south to west.
Britt
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...None.
IL...None.
&&
$$
WFO LSX
Area Forecast Discussion
National Weather Service Norman OK
834 PM CST Thu Nov 17 2016
.DISCUSSION...
Rather mild temperatures for mid November remain in place this
evening, but a much cooler airmass will surge southward
late this evening and overnight.
The wind will remain rather strong ahead and behind the front. A
few wind gusts over 40 mph have been record just ahead of the
front in northwestern Oklahoma during the last hour. RAP and NAM
soundings suggest some gusts over 35 mph will be possible behind
the front, especially across the northern half of Oklahoma.
Farther south, scattered showers and perhaps a few storms may
develop mainly along and southeast of a Seminole to Ardmore line.
Although rather meager, somewhat better moisture is in place
across southeast Oklahoma.
Overall, will leave high chance POPs in place and increase winds
some for the late evening and overnight period.
&&
.PREV DISCUSSION... /issued 554 PM CST Thu Nov 17 2016/
UPDATE...
Cancelled the Red Flag Warning and Wind Advisory. Expanded the
Freeze Watch a bit farther northwestward Friday night into
Saturday morning.
DISCUSSION...
Made the cancellation to the Red Flag Warning in northwestern
Oklahoma since surface relative humidity values stayed above 20%
and since there wasn`t any significant wildfire activity in the
warned area this afternoon.
Cancelled the Wind Advisory since most gusts stayed below 40 mph
late this afternoon likely due to reduced vertical mixing from
incoming thick mid/level cloud cover.
The Freeze Watch was expanded northward to include all of northern
Oklahoma except Harper county where a hard freeze (surface lows
28F or lower) has already occurred.
Products have been updated.
Aviation discussion for the 00 UTC is below.
06/17
AVIATION...
Overall, VFR conditions are expected to continue.
Gusty south surface winds will continue at many sites before the
passage of a cold front that will quickly move northwest to
southeast across Oklahoma and western north Texas 03-12 UTC. A
wind shift to the north/northwest will occur behind the front with
surface winds increasing and become very gusty at all sites by 15
UTC.
Added non-convective low level wind shear at KLAW before 05 UTC
where confidence of occurrence is moderate.
Brief MVFR ceilings may form near and just behind the cold front
at many sites. Did not mention due to low confidence of
occurrence. KPNC has the greatest chance for MVFR ceilings
06-18 UTC.
MBS
PREV DISCUSSION...
/issued Issued by National Weather Service Fort Worth TX/
DISCUSSION...
Afternoon water vapor imagery depicts a strong upper trough
becoming negatively tilted as it progresses across the Central
Plains. This is prompting strong surface cyclogenesis with a surface
low deepening across the OK Panhandle. As a result, strong
southerly winds will continue within the warm sector of this low
with sustained winds around 20 mph and gusts up to 35 mph. The
Wind Advisory will be allowed to continue through this evening
for our northeastern counties. In addition, a Red Flag Warning
remains in effect for Harper, Ellis, and Roger Mills counties
through this evening where humidity along an ill-defined dryline
has fallen to 30% or less.
Tonight, the strong cold front associated with the aforementioned
surface low will push through all of OK. As the front reaches the
more favorable low-level moisture southeast of the OKC area, a
thin band of showers and storms should form immediately along the
front and track to the southeast. With storms quickly being
undercut by the advancing colder air, storms should struggle to
become strong despite some favorable deep-layer shear. In the
wake of the cold front, temperatures will fall into the low 40s
across western and northern OK Friday morning.
Breezy north winds will follow behind the front causing cold/dry
air advection to continue into Friday. With much drier air and
still gusty winds at times on Friday afternoon, some elevated fire
weather conditions will be possible across the western half of the
state. High temperatures however will be slightly below normal
ranging from around 50 in the northwest to 60 in the southeast.
Very favorable radiational cooling conditions will be present on
Friday night and Saturday morning with clear skies, light winds,
and dry air at the surface. This should cause temperatures to
tank to their lowest values of the season so far with most of the
area falling below freezing. Have issued a Freeze Watch with this
forecast package except for our far southeastern counties along
the Red River (this also omits counties that have already had both a
freeze and a Freeze Warning). This Freeze Watch will likely be
upgraded to a Freeze Warning for most of the area, but some
locations in northwest OK may fall to near or below 28 degrees
which could make a Hard Freeze Warning necessary. Lows on Sunday
morning should be slightly warmer as light southerly winds return
to the area.
As upper ridging takes hold in the wake of the upper trough, a
gradual warming trend will occur into early next week. A
progressive weather pattern will be the story for next week with
a pair of strong shortwaves and cold fronts expected to affect the
area. The first storm system should impact the area on Tuesday
through early Wednesday when scattered storms will be possible
mostly across central OK along a weak cold front. At this time,
Thanksgiving looks dry and seasonably cool. However, the next
storm system appears that it may begin to affect OK late Thursday
night or Friday morning, although the GFS and ECMWF still differ
on the timing and depth of this latter shortwave that would bring
additional thunderstorm chances with another cold front through
the region.
PREV DISCUSSION... /issued 501 AM CST Thu Nov 17 2016/
DISCUSSION...
12Z TAF discussion below.
AVIATION...
VFR conditions expected through the TAF period with mid and high
clouds streaming across the region. Winds will increase today and
shift towards the NW this evening into Friday morning as a cold
front moves across the region. Rain is expected to remain south
and east of the TAF sites late tonight/Friday morning.
&&
.PRELIMINARY POINT TEMPS/POPS...
Oklahoma City OK 47 53 28 53 / 10 0 0 0
Hobart OK 45 54 28 53 / 10 0 0 0
Wichita Falls TX 50 57 30 57 / 10 0 0 0
Gage OK 39 49 23 54 / 10 0 0 0
Ponca City OK 46 50 26 51 / 10 0 0 0
Durant OK 59 60 34 56 / 50 10 0 0
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...Freeze Watch from Friday evening through Saturday morning for
OKZ005>042-044>046.
TX...Freeze Watch from Friday evening through Saturday morning for
TXZ083>090.
&&
$$
Area Forecast Discussion
National Weather Service Shreveport LA
940 PM CST Thu Nov 17 2016
.DISCUSSION...
Cold front moving into OK panhandle and lacking in nocturnal
convection thus far. Areal 0z soundings quite dry across the
south, and even very marginal for any convection at KOUN sounding.
HRRR is still in line with chance of late night pops north of I-30
so will not change pops. However, adjusted eastern CWA overnight
lows upwards at least a couple of degrees as south winds and
dewpoint trends suggest overnight lows to remain above 60 degrees
across most of northcentral LA and sw AR./VII/.
&&
.PREV DISCUSSION... /issued 555 PM CST Thu Nov 17 2016/
AVIATION...
VFR conditions occurring this evening but conditions are expected
to deteriorate throughout the TAF cycle courtesy of an approaching
upper level disturbance. Ahead of the disturbance, will be the
development of MVFR-IFR cigs for all the terminals overnight, as
well as the potential for MVFR-IFR fog particularly at klfk for a
brief period. Elsewhere, fog may be hard-pressed to develop given
wind speeds staying up at around 10 kts. This disturbance will
bring with it chances for -SHRA/-TSRA commencing around daybreak
for western terminals and spreading to the remaining terminals
throughout the day with kmlu and keld likely just starting to
experience -SHRA just beyond the scope of this TAF period. Winds
will veer to the northwest by the end of the TAF period with the
impingement of a cold front, thus winds will stay up in the 10-12
kt range.
PREV DISCUSSION... /issued 240 PM CST Thu Nov 17 2016/
DISCUSSION...
Another very unseasonable warm mid November day with current
temperatures a degree or two either side of 80 degrees once again.
All that will come crashing to a halt with the arrival of a
strong cold front moving through our region on Friday...bringing
with it showers and thunderstorms and an end to these well above
normal temperatures.
Strong pressure gradient currently in place across the entire Four
State region ahead of our upper level storm system which is
currently across the Inter Mountain West. Strongest winds by far
today have remained across our far western counties across
Northeast Texas and Southeast Oklahoma. Current Lake Wind Advisory
goes until 4 pm across these counties and will allow it to expire
on time. Upper trough axis begins to push into the Plains
overnight tonight with moderate to strong PVA pushing eastward
into Eastern Oklahoma/North Texas Friday morning. Should begin
seeing a broken line of showers and thunderstorms developing
across this region between midnight and sunrise Friday morning
with this line slowly moving eastward into our region during the
post sunrise hours Friday morning.
Ingredients for severe thunderstorms are not spectacular as the
best dynamics associated with the trough will be north of our
region. However...our area should see the greatest instability
with MLCAPE ranging from 250-750 J/KG with Deep Layer shear in the
vicinity of 30-40kts. Low level shear is weak as flow should begin
veering just ahead of the line of storms on Friday. All this to
say that we cannot rule out a strong to severe thunderstorm with
thunderstorm wind gusts being the main threat followed by a hail
threat but at this time...widespread severe thunderstorms does not
appear likely.
Expecting much colder temperatures behind the front along with
strong northwest winds that could approach post frontal Lake Wind
Advisory Criteria Friday Afternoon across some areas before winds
try to decouple Friday Night. Rainfall amounts are not great...but
we will take anything we can get given the increasing drought
conditions across most of our region and the current Burn Bans in
place. We will approach freezing temperatures across our portions
of Southeast Oklahoma and Southwest Arkansas early Saturday
Morning despite the winds staying up which is a true nature of the
strong Cold Air Advection our area will be dealing with behind
this cold front.
Saturday...while sunny...will be a chilly one with temperatures
struggling to reach the 60s by afternoon which coupled with strong
northerly winds will make it feel even colder. A 1035mb sfc ridge
axis will quickly move our way Sat Night/Sun Morning and this will
result in these winds quickly decoupling and becoming near calm
across much of the region. While there may be some thin cirrus
across Eastern Oklahoma and Central Arkansas...it should not
influence ideal radiational cooling conditions which means that
much of our region should see its first freeze of the fall season
Saturday Night/Sunday Morning. We will likely be issuing Freeze
Warnings for the region for this period as the weekend approaches.
As fast as the sfc ridge gets here Sat Night...its east of us Sun
Night/Mon Morning but not before our eastern zones could see
freezing conditions again during this period.
The upper pattern appears to be becoming more progressive through
much of next week with at least 2 additional troughs fcst to
influence our region...the first on Tue and perhaps another one on
Black Friday. This more progressive pattern should result in less
prolonged warming trends with of course better chances of rain
with the arrival of each trough.
Thanks for the coordination this aftn...FWD...TSA...JAN. Prelims
to follow...13.
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 64 74 41 61 / 10 80 0 0
MLU 62 80 42 61 / 10 80 70 0
DEQ 61 67 32 59 / 40 80 0 0
TXK 64 69 37 60 / 30 80 0 0
ELD 61 74 36 60 / 10 80 0 0
TYR 65 68 39 60 / 20 80 0 0
GGG 64 70 39 61 / 20 80 0 0
LFK 63 76 41 63 / 10 70 0 0
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...None.
LA...None.
OK...None.
TX...None.
&&
$$
Area Forecast Discussion
National Weather Service SAN ANGELO TX
533 PM CST Thu Nov 17 2016
.AVIATION...
/00Z TAFS/
VFR conditions continue across West Central Texas, although a
shield of high cloudiness is working its way across the area. The
high resolution data suggests that MVFR cigs will make a run into
portions of the area overnight, perhaps as far north as KSJT (San
Angelo) ahead of the strong cold front. The front should reach
KABI (Abilene) shortly after midnight and then clear the rest of
the terminals by around sunrise. Showers and a few storms are
possible along the front, but should remain brief and not very
widespread. Gusty north winds to be the main issue for Friday.
&&
.PREV DISCUSSION... /issued 320 PM CST Thu Nov 17 2016/
SHORT TERM...
(Tonight and Friday)
Main concern for tonight is the threat for thunderstorms in the
Northwest Hill Country as the cold front approaches. Latest NAM12
model soundings show decent Most Unstable CAPE values for this time
of year between 09z and 12z. The values ranged from 1500 to 1700
J/KG near Junction with dewpoints in the low to mid 60s, but the CIN
of -30 to -50 may be enough to sustain the capping inversion. HRRR
and the Texas Tech WRF show a fine line of precipitation forming,
but nothing of consequence.
At any rate, if a storm can break through the CAP, it could produce
an isolated strong thunderstorm, with some small hail and gusty
winds tomorrow morning, mainly along and southeast of a line from
San Saba to Mason to Junction. Will highlight this threat in the
Hazardous Weather Outlook. Have continued the trend of chance Pops
for the Northwest Hill Country.
The cold front should slide across the area between Midnight and 6
AM tonight, sweeping the low level moisture east and ushering in
cool and breezy north winds to the region tomorrow. Highs on Friday
will only climb into the upper 50s north to the low to mid 60s
south.
LONG TERM...
(Friday Night through Sunday)
As surface high pressure settles over the area this weekend along
with a dry airmass, ideal radiational cooling will be in place
Friday and Saturday nights, especially south of the I-20
corridor. The MEX guidance is still indicating lows in the upper
20s to lower 30s across across the Northwest Hill Country and
Heartland on west along the I-10 corridor by Sunday morning. The
first freeze of the season may be possible across these areas.
Going with lows in the lower to mid 30s, with upper 20s possible
Sunday morning, especially low lying areas and river valleys.
Going to continue the SPS for possible freezing temperatures and
areas of frost. Highs will be in the upper 50s to mid 60s.
(Sunday Night through Thursday)
For early next week, expect a warming trend and mainly a dry
forecast. A few showers and thunderstorms are possible Tuesday
across the Big Country and Heartland. The temperatures will be
little cooler Wednesday due to the passage of a cool front. Also,
expect gusty south to southwest winds on Tuesday. Highs will be in
the upper 60s to mid 70s, with lows in the 40s and 50s.
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 51 60 34 57 / 10 0 0 0
San Angelo 53 62 35 59 / 20 5 0 0
Junction 58 65 35 60 / 20 30 0 0
Brownwood 55 61 36 57 / 30 10 0 0
Sweetwater 49 58 34 56 / 5 0 0 0
Ozona 51 61 34 58 / 10 5 0 0
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
07
Area Forecast Discussion
National Weather Service Tampa Bay Ruskin FL
826 PM EST Thu Nov 17 2016
.UPDATE...
01Z water vapor and H4 RAP analysis shows an amplified upper level
flow over North America this evening. Most impressive
feature...and all eyes go directly to the potent trough/shortwave
digging out of the inter-mountain west...and about to overspread
the central Plains. This feature will support an area of low
pressure that will lift quickly toward the upper MS valley over
the next 24 hours...and result in thunderstorms to the south of
its track and areas of blizzard conditions to the NW/west of its
track. So...folks across the central and north-central parts of
the country have some inclement weather to get through.
However...not so for the southeast conus and Florida peninsula.
WV imagery shows our region protected and under the control of
strong mid/upper level ridging extending from the Gulf of Mexico
to the TN/OH valleys and eastward to the FL peninsula.
This evening`s 00Z KTBW sounding is impressively dry due to the
synoptic suppression of the upper ridge with a measured PW value
around 0.4". This reading is very low for anytime of year. The
sounding profile shows large dewpoint depression through the
extent of the troposphere...and it is no wonder our skies are
completely clear region-wide this evening.
Overall synoptic pattern will not change much during the next 24
hours. If anything...the height falls across the middle/lower MS
valley on Friday will help push the upper ridge axis eastward and
directly overhead. Closer to the surface the ridge centered over
coastal GA/Carolinas will settle southward into north
Florida...providing true stacked ridging for the final day of the
work week. We may see just enough Atlantic moisture below 850mb by
the afternoon for a shallow few-sct cumulus field to form from the
I-4 corridor southward...but that would really be the only change
for the forecast from Thursday. Mostly sunny vs sunny. Low temps
early Friday morning ranging from the mid/upper 40s for Levy
County...to the lower/mid 50s across the I-4 corridor...and
middle/upper 60s around Fort Myers. Normally warmer spots under
easterly flow (southern Pinellas/Coastal Charlotte/Lee should stay
in the lower/mid 60s. High temperatures Friday afternoon within a
degree or two of 80 region-wide.
Still looking for a well defined frontal boundary to cross the
region Saturday evening/overnight...however...extremely limited
column moisture and weak synoptic lift should keep this a dry
frontal passage. Temperatures look like they will at least take a
brief tumble...although nothing record breaking is in the
forecast. However...the kids will likely need a jacket at the bus
stop Monday morning.
The biggest impact from this frontal passage will be rapidly
increasing winds and seas over the coastal waters Saturday
night/Sunday morning in the wake of the front. Boaters planning
maritime activities this weekend should check the latest forecast
before heading out as small craft advisories are likely to be
required for the second half of the weekend.
&&
.AVIATION (18/00Z through 19/00Z)...
VFR conditions prevail through the duration of the TAF period.
Clear skies overnight with a light northeast wind. Friday will
feature mostly clear skies in the morning with a shallow few-sct
cumulus field above 4Kft for the afternoon. Winds increase to
between 6-10 knots out of the northeast and north during the late
morning and afternoon.
&&
.Preliminary Point Temps/PoPs...
TPA 59 81 62 78 / 0 0 0 0
FMY 59 82 60 81 / 0 0 0 0
GIF 57 80 59 80 / 0 0 0 0
SRQ 58 79 60 78 / 0 0 0 0
BKV 52 79 54 78 / 0 0 0 0
SPG 62 79 64 77 / 0 0 0 0
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...Beach Hazards Statement through Monday afternoon for
Coastal Charlotte-Coastal Manatee-Coastal Sarasota.
Gulf waters...None.
&&
$$
UPDATE/AVIATION...Mroczka
...Update to aviation forecast discussion...
.SHORT TERM...(This evening through Friday)
Issued at 229 PM CST Thu Nov 17 2016
This afternoon, a surface front was located across the northwest
portion of the CWA creating both a temperature and wind gradient
across the area. Ahead of this front, southerly winds have been
gusty with sustained winds near 25 mph and gusts up to 45 mph in
some areas. Near this boundary, winds are near calm with light
northwesterly winds behind the front. Due to the progression of
this low and observations from this afternoon, have opted to keep
the wind advisory, but not expand it to any areas generally north of
I-35. As the main mid-level trough digs across the Central Plains
this evening and overnight, another surface low builds into
southwestern Kansas and will move across the state by early morning
bringing the surface front through northeast Kansas. An increase of
winds in east central Kansas ahead of this secondary low is
expected, although with winds only on the cusp of advisory criteria
today, have decided not to extend the advisory with only gusts up to
40mph possible through the evening. Post frontal precipitation is
possible with the best chances in very north central Kansas as
precipitation wraps behind the departing low. While the NAM does
show light precipitation forming along the trough very early morning
near the KS/MO boarder, this seems to be the outlier. Temperatures
overnight will vary due to the frontal passage with mid 30s expected
in north central Kansas and mid-40s near east central Kansas. For
tomorrow, colder temperatures stream in behind the front along with,
once again, strong winds. Sustained winds near 20 mph with gusts up
to 40 knots will be seen throughout the morning and afternoon.
Overcast to broken skies in the morning look to linger on through
the day. Highs tomorrow will be even slightly below average in the
mid 40s to low 50s.
.LONG TERM...(Friday night through Thursday)
Issued at 229 PM CST Thu Nov 17 2016
Expansive high pressure will build southward behind the departing
system this weekend. Cooler temperatures and light winds will allow
lows to drop into the 20s both Sat and Sun morning. Return flow
develops on Sunday causing the temperatures to moderate back to near
normal with highs in the highs in the 50s and lows in the 30s. Weak
ridging aloft moves across the central US also keeping temperatures
from dropping. Towards mid week quasi-zonal flow aloft brings a few
shortwaves over the region. Both systems do not appear deep enough
to tap into the arctic air, which is mild anyway. The system on
Tuesday tracks fairly close by and some models are producing a
decent amount of QPF, while the system on Friday appears to be much
drier. Some of the models are showing some instability on Tuesday
therefore thunder will be possible.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 542 PM CST Thu Nov 17 2016
A cold has moved through MHK as of 00Z, hence the winds have
veered to the northwest. These winds will become gusty by 06Z with
sustained 15-20 knots and gusts 25-30 knots. MVFR cigs are also
expected to brush the MHK terminal, however these cigs should
remain north of the Topeka terminals. The wind shift is expected
at the Topeka terminals near 08Z with sustained westerly winds
similar to MHK, eventually veering to the northwest by dawn
Friday morning. Winds may begin to lighten near the end of the
period.
&&
.FIRE WEATHER...
Issued at 229 PM CST Thu Nov 17 2016
Very high fire danger conditions today as gusty southerly winds
continue at 20 to 30 mph sustained with gusts up to 40 mph through
early afternoon. Main uncertainty lies with dewpoints. Due to the
poor handling of dewpoints mixing heights from guidance yesterday,
trended towards the drier HRRR and RAP solutions for this type of
setup. Combined with the warm temps in the upper 70s to near 80
degrees, could only calculate minimum humidity values in the lower 30
percent range, which occurs during the late afternoon period. Winds
however weaken some by this time as a prefrontal sfc trough bisects
the area. Still should see winds in excess of 20 mph sustained for
eastern and far northeast Kansas during this time, however RH values
are forecast to not reach 20 percent. For this forecast, will
mention the very high fire danger wording, but do not plan on
issuing headlines.
Winds on Friday will be sustained in the 20-30 mph range with
occasional gusts to 35 mph or stronger out of the northwest.
Temperatures will be much cooler and this will keep RH values in
check with MinRH probably holding in the 35 to 43 percent range.
While this has been as strong storm system, it will result in
little to no precipitation for the local are so any fuels should
still be rather dry through Friday.
The next good chance for rain comes early Tuesday morning through
Tuesday night. This appears to be a pretty good chance for
widespread rain showers.
&&
.CLIMATE...
Issued at 310 PM CST Tue Nov 15 2016
Current Record High Temperatures
----------------------------------------------------------
November 17
Topeka 76
(year) (1999)
Concordia 76
(year) (1943)
Current Record Warm Low Temperatures
----------------------------------------------------------
November 17
Topeka 56
(year) (1941)
Concordia 57
(year) (2004)
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
Wind Advisory until 6 PM CST this evening for KSZ040-054>056-058-
059.
&&
$$
SHORT TERM...Heller
LONG TERM...Sanders
AVIATION...Baerg
FIRE WEATHER...Prieto
CLIMATE...Prieto
Area Forecast Discussion
National Weather Service Billings MT
207 AM MST Fri Nov 18 2016
.SHORT TERM...valid for Tdy and Sat...
There was a small area of weak radar echo mainly over northern
Big Horn County early this morning. There were possibly flurries
occurring with this echo as a wave was moving through the area.
Models had this wave along the border of SE MT by 12Z so will keep
the forecast for today dry. Left some patchy fog near and W of
KBIL this morning as light fog keeps redeveloping over KBIL and
the HRRR supported some patchy fog. Otherwise, cloud cover should
keep fog from becoming widespread.
A flat NW flow will be over the area today and will transition to
an upper ridge that will prevail over the region through Sat.
night. No precipitation was forecast for the period, but
occasional clouds will move through the region as a weak Pacific
system crosses the area. Soundings showed limited mixing today, so
have lowered temperatures slightly. Also a drainage wind will keep
Billings on the cool side. Saturday looked warmer...in the
40s...due to a moderating airmass. Some areas, like KLVM, will be
breezy on Sat. due to better mixing and a faster flow aloft.
Arthur
.LONG TERM...valid for Sun...Mon...Tue...Wed...Thu...
Ridging on Sunday breaks down Monday as a trof pushes over the
area. Dynamics are pretty weak with this system at this point with
main jet support well south of the area. However push of Pacific
moisture with the trof should bring a good chance of snow to area
mountains...while the lack of dynamics keeps weak chances across
the lower elevations Monday into Monday evening. Shortwave ridging
builds in for Tuesday and Wednesday before another trof pushes
across on Thanksgiving. This trof does have more support aloft
with a southwesterly jet moving over the area early in the morning
then a second impulse later in the day providing some coupled
dynamics along with more Pacific moisture. For now will keep
precipitation chances low outside of the mountains but will have
to keep an eye on this system for further development over time.
Temperatures will be pretty consistent in the 45 to 55 degree
range through the extended period. Overall pattern also favors
periods of gusty winds along the western foothills, particularly
ahead of the aforementioned trofs. Chambers
&&
.AVIATION...
Patchy fog expected this morning over low lying areas and in the
KBIL vicinity. Expect localized visibilities down to 1/2sm with
any fog. Fog and VFR ceilings will erode through the morning
hours along with any lingering snow flurries. No aviation hazards
expected this afternoon into tonight. Chambers
&&
.PRELIMINARY POINT TEMP/POPS...
Tdy Sat Sun Mon Tue Wed Thu
-------------------------------------------------------
BIL 035 021/044 029/050 033/049 031/046 028/044 030/046
0/U 00/B 00/B 11/E 21/B 10/B 12/W
LVM 038 024/048 034/052 033/048 030/044 029/045 030/042
0/U 00/N 01/N 23/W 22/W 11/N 33/W
HDN 039 017/047 022/052 031/050 030/047 027/046 028/046
0/B 00/B 00/B 11/B 21/B 10/B 12/W
MLS 039 022/044 025/052 030/050 031/045 026/046 028/046
0/B 00/B 00/U 01/B 21/B 10/U 02/W
4BQ 035 014/040 020/050 029/050 030/046 026/046 026/047
0/B 00/B 00/U 11/B 21/B 10/U 02/W
BHK 034 015/039 019/050 028/047 029/042 024/043 026/045
0/B 00/B 00/U 00/B 21/B 10/U 02/W
SHR 035 011/042 022/049 029/047 028/043 022/043 024/045
0/U 00/B 00/U 01/B 31/B 10/B 02/W
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...None.
WY...None.
&&
$$
weather.gov/billings
Area Forecast Discussion
National Weather Service Cheyenne WY
1025 PM MST Thu Nov 17 2016
.UPDATE...
Issued at 1016 PM MST Thu Nov 17 2016
Latest IR imagery showing warming cloud tops out across the
Nebraska Panhandle this evening. The associated low looks to be
now in south central Nebraska this evening with the colder wrap
around cloud tops east of our CWFA. Based on this and METAR obs
out in the Panhandle reporting visibilities better than 1 mile,
went ahead and cancelled winter headlines early.
&&
.SHORT TERM...(This evening through Saturday Night)
Issued at 155 PM MST Thu Nov 17 2016
Upper low progressing east across central Colorado this afternoon
with snow expanding slowly across the CWA. Some enhanced banding
of snow seen on radar over far se Wy into the sw Panhandle...
looking associated with a small circulation center southwest of
Cheyenne. This will likely bring a period of more moderate snow to
the area through late this afternoon. Current hilites/snowfall
amounts look to be in good shape overall though some concern
about snow amounts over the northern Panhandle. Will not make any
changes at this time to the hilites.
The upper low over Colorado will turn northeast and accelerate
tonight while a surface low moves across Kansas into Iowa. This
will bring an end to the snow with only a few lingering flurries
expected after midnight. A cold surface high will settle into
Wyoming overnight with temps falling into the teens to lower
20s...with some single digits over western valleys. Friday will be
cool with clearing skies across the CWA as high pressure slides
across the area into the central and southern plains. Chilly again
Friday night with mainly clear skies and light winds. Dry and
warmer Saturday as upper ridging moves across the region.
.LONG TERM...(Sunday through Thursday)
Issued at 155 PM MST Thu Nov 17 2016
This discussion is abbreviated due to ongoing, high-impact weather
across the region. Mild and dry conditions will prevail for Sunday
with upper-level ridging in place. Medium range models are in good
agreement with the development of a more unsettled pattern on Mon/
Tue as a fast-moving shortwave tracks across the Great Basin. This
system will not be as strong as the current one, but does have the
potential to produce minor snowfall accumulations depending on the
timing of the cold front. Quiet weather is likely for Wednesday as
the CWA will be in between weather systems.
&&
.AVIATION...(For the 06Z TAFS through 06Z Friday night)
Issued at 1016 PM MST Thu Nov 17 2016
Used latest HRRR guidance for the 06Z TAFs. Showing low clouds
pulling off to the east as the low pressure system continues to
move east into central Nebraska. A few more hours of snow and low
clouds and then we should see improving conditions at KCDR, KAIA
and KSNY.
&&
.FIRE WEATHER...
Issued at 155 PM MST Thu Nov 17 2016
Fire weather concerns pretty much nil through the weekend with
cool to mild temperatures expected. Snow across the area into this
evening will end overnight then mainly dry through the weekend.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...None.
NE...None.
&&
$$
UPDATE...GCC
SHORT TERM...RE
LONG TERM...CLH
AVIATION...GCC
FIRE WEATHER...RE
Area Forecast Discussion
National Weather Service Houston/Galveston TX
1154 PM CST Thu Nov 17 2016
.AVIATION...
Main aviation concerns for the 18/06Z TAFs continue to revolve
around timing of a cold front and associated TSRA/SHRA during the
day Friday, with isolated to scattered SHRA ahead of the front and
increasing northerly winds behind the front. Additionally, LLWS
may result in impacts for College Station and possibly Huntsville
tonight.
Southerly surface winds have fallen to 10 knots or less at the
terminals, but the KGRK VAD wind profiler shows a 45-50 knot low
level jet has developed across Central Texas. Have included a LLWS
group at College Station as a result as loss of daytime heating
has allowed the surface pressure gradient to relax a bit despite
the approach of a cold front in Northwest Texas. Expect Huntsville
to be on the eastern core of this jet and have not included a
mention, but amendments may be needed should the jet shift farther
east.
Otherwise, expect VFR conditions are expected to prevail across
the Southeast Texas terminals tonight and through Friday evening.
Increasing moisture will allow for the development of VFR ceilings
around 4-6kft AGL. May see a lower, scattered deck develop but
anticipate the higher deck to keep conditions VFR through the
night.
A cold front will reach the Southeast Texas terminals tomorrow and
have updated timing based on latest runs of the HRRR and linear
extrapolation of the front`s movement. Expect the front to reach
and clear College Station between 17-20Z, the Houston terminals
between 20-23Z, and Galveston 23-02Z. Isolated SHRA will be
possible ahead of the front, with a broken line of SHRA/TSRA
expected to accompany the front. Temporary MVFR ceiling and
visibility restrictions MVFR are possible with TSRA. Expect
southerly winds around 10 knots Friday morning to veer to the west
around 10-15 knots ahead of the front in response to the
prefrontal trough. Northerly winds 10-15 knots (with stronger
gusts 20-25 knots) are expected with and behind the front.
Stronger winds are expected for Galveston, with northerly 20-25
knot winds gusting to 30-35 knots Friday evening. Expect skies to
gradually clear behind the front as drier air moves into the
region.
Huffman
&&
.PREV DISCUSSION... /ISSUED 954 PM CST Thu Nov 17 2016/
UPDATE...
A few sprinkles moving onshore with speed convergence near the
coast this evening and should continue overnight. Will carry
slightly chance pops for the coastal areas and nearshore waters
through sunrise. A short break in the cloud cover this evening but
after midnight expect skies to begin to fill in with cloud cover
and by morning most areas should be mostly cloudy. The WAA will
keep it warm and humid tonight. The big cold front is moving into
the Panhandle with snow in Nebraska. As the cold front moves into
the region during the afternoon and departs the Gulf waters in the
evening expecting scattered showers and thunderstorms to move
through the region with a good chance (60-80 percent) of rainfall.
May see a few showers or thunderstorms to the west of or around
Matagorda Bay after sunrise. Post frontal it is going to be the
coldest air of the season so far and wind chill readings will
tumble into the 30s for most sites by sunrise Saturday and
struggle to reach the mid 50s by noon so be sure to dress warmly
if you will be outdoors Saturday morning.
Will hoist a Gale Watch for the marine areas in anticipation of
the strong CAA over the warm Gulf waters with 975-875mb level
winds in excess of 40 knots giving the potential for sustained
north winds across the marine waters of 25 knots and possibly
gusting 35 to 40 knots.
45/14
&&
.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL) 67 73 42 62 37 / 10 70 0 0 0
Houston (IAH) 68 80 46 64 40 / 10 70 10 0 0
Galveston (GLS) 74 80 53 63 51 / 20 60 40 0 0
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...Gale Watch from Friday evening through Saturday morning for the
following zones: Coastal waters from Freeport to the
Matagorda Ship Channel out 20 NM...Coastal waters from High
Island to Freeport out 20 NM...Galveston Bay...Matagorda
Bay...Waters from Freeport to the Matagorda Ship Channel
from 20 to 60 NM...Waters from High Island to Freeport from
20 to 60 NM.
SMALL CRAFT SHOULD EXERCISE CAUTION until 6 AM CST Friday for
the following zones: Coastal waters from Freeport to the
Matagorda Ship Channel out 20 NM...Coastal waters from High
Island to Freeport out 20 NM...Waters from High Island to
Freeport from 20 to 60 NM.
Small Craft Advisory until 6 AM CST Friday for the following
zones: Waters from Freeport to the Matagorda Ship Channel
from 20 to 60 NM.
&&
$$
Discussion...45
Aviation/Marine...14
Area Forecast Discussion
National Weather Service North Platte NE
329 AM CST Fri Nov 18 2016
.SYNOPSIS...
Issued at 326 AM CST Fri Nov 18 2016
At 09z...The upper closed low was centered near Kearney Nebraska. A
broad area of light to moderate snow continued across much of
Nebraska into central and eastern South Dakota. temperatures mainly
in the upper 20s in western Nebraska with northwest winds 25 knots
gusting to 35 knots in some areas.
A cold front has advanced through western Nebraska with northerly
winds of 10 to 20 mph and temperatures in the low to mid 40s.
Snowfall occurring over portions of Montana, Wyoming, and Utah.
&&
.SHORT TERM...(Today and tonight)
Issued at 326 AM CST Fri Nov 18 2016
Today...The winter storm has brought widespread snowfall amounts of
3 to 5 inches to most of western Nebraska, while new snowfall will
accumulate across the eastern half of the forecast area this
morning. Forecast storm total snow amounts look close to observed so
far. Northwest winds have increased with recent gusts now as high as
35 knots at LBF, and this is causing considerable blowing snow.
The winter storm system is beginning to lift out of southwestern
portions of the forecast area. A well development deformation band
extends south from near Newport through Brewster to Callaway. The
RAP13 and HRRR both indicated this band will fill in and rotate
northeast early this morning, exiting the forecast area by 18z.
Likely to definite pops beginning at 12z from east of Springview
through Burwell. Up to 1.5 inches of new snow these areas with only
a dusting up to an inch to the west from Valentine thorugh Broken
Bow. The existing Winter Storm Warning and Winter Weather Advisory
will continue until 18z with impacts from blowing snow to continue
this morning across the west. The winter Storm Warning to continue
across the northeast zones this afternoon as impacts from blowing
snow may continue.
The northwest winds will begin to diminish by mid afternoon.
Although mostly sunny skies will return to the west, a widespread
blanket of snow across the region will limit high temperatures.
Highs were lowered slightly below model guidance, from 30-32 north
central, to 33-36 across the south.
Tonight...Mainly clear skies this evening, then increasing high
cloudiness after midnight as the upper ridge axis builds across the
Central Rockies. Went below previous forecast lows a few degrees to
the upper single digits to low teens most areas. Winds chills will
fall into the low single digits in most areas late this evening
and overnight.
.LONG TERM...(Saturday through Thursday)
Issued at 326 AM CST Fri Nov 18 2016
Upper level ridging aloft will dominate the weather Saturday through
Monday. Highs will gradually warm from 35 to 45 degrees Saturday to
48 to 58 degrees by Monday. The cooler readings will be across
eastern portions of north central Nebraska, with the warmer readings
across southwest and western Nebraska.
Another system is slated to move across the area Tuesday. This will
be another quick moving system, but is expected to pack somewhat of
a punch with decent upper level dynamics crossing the area. Still
appears temperatures aloft will be several degrees warmer than what
is occurring with this current system, and most of the precipitation
will fall as rain. Some wet snow is possible, but little if any
impact is expected from the snow at this time. As mentioned this
will be a quick moving system, with upper level ridging and warmer
weather returning for Wednesday and Thanksgiving.
&&
.AVIATION...(For the 06Z TAFS through 06Z Friday night)
Issued at 1127 PM CST Thu Nov 17 2016
The ongoing widespread IFR/local LIFR in snow and low CIGS is
expected to translate slowly east overnight and exit Holt County
around 15z Friday morning. Flight conditions will improve from
west to east as this happens with MVFR developing.
Widespread VFR/MVFR CIGS are expected from 15z-23z Friday.
VFR is expected all areas 23z-06z Friday but there is a slight
chance that MVFR cigs will continue across areas east of KVTN-
KTIF.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory until noon CST /11 AM MST/ today for
NEZ022-056>058-069>071.
Winter Storm Warning until noon CST /11 AM MST/ today for NEZ004-
005-023>026-035>038-059-094.
Winter Storm Warning until 6 PM CST this evening for NEZ006>010-
027>029.
&&
$$
SYNOPSIS...Roberg
SHORT TERM...Roberg
LONG TERM...Taylor
AVIATION...CDC
Area Forecast Discussion
National Weather Service Saint Louis MO
340 AM CST Fri Nov 18 2016
.SHORT TERM... (Through Late Tonight)
Issued at 340 AM CST Fri Nov 18 2016
An upper level trough centered over south central Nebraska and an
associated developing surface low over northwestern MO with a
trailing cold front extending southwest into central OK will move
eastward through our forecast area today. Upper level divergence
will ramp up over our area this morning ahead of the upper level
trough. A band of showers should develop and move through parts of
northeast and central MO this morning, then the intensity and
coverage of the precipitation should increase late this morning and
this afternoon just ahead of the cold front across east central and
southeast MO and southwest IL as the atmosphere destabilizes. The
HRRR model depicts thunderstorms across southeast MO and southwest
IL this afternoon. Could not rule out a few severe storms with
damaging winds. This will be a low CAPE/high shear environment with
a 70-80 knot mid level jet streak moving through the area. Strong
low level cold air advection behind the cold front will lead to
falling temperatures late this morning across northeast and central
MO and across the rest of our area this afternoon. The wind will be
strong and gusty again today due to a tight surface pressure
gradient. It appears that most of the convection will shift
southeast of our forecast area by early evening as the cold front
shifts southeast of the area with low level cooling and drying
behind the cold front as a strong 1035-1040 mb surface ridge builds
southeastward into our region behind the cold front. Much colder
temperatures are expected tonight with decreasing cloudiness from
southwest to northeast later this evening and overnight. The 850 mb
temperature will drop down to around 6 degrees below zero C in STL
by midnight tonight. Although the low temperatures tonight will only
be a couple of degrees below normal it will feel cold after the
unseasonably warm weather of the past two days, plus winds will be
relatively strong for the nighttime hours. Lows will be below 32
degrees across parts of northeast and central MO into the Ozarks and
also in west central IL.
GKS
.LONG TERM... (Saturday through Thursday)
Issued at 340 AM CST Fri Nov 18 2016
(Saturday - Monday)
A quiet period of wx is expected with slowly warming temperatures.
Northwest flow aloft will prevail and be disturbance free in a
largely dry column. The coolest day will be Saturday in the wake
of the departing storm system in a brisk NW surface flow, but temps
will only be relatively cool as forecast high temps will be a mere 5
degrees below average. By Monday, with the surface RIDGE to our
east, temps will have recovered some to where daytime max temps are
expected to be about 5 degrees above average.
(Tuesday - Thursday)
The lone pcpn event during this stretch is slated to occur towards
the middle of next week with flow aloft switching from the southwest
and upper level disturbances quickly follow. Moisture return should
be significant with not just a favorable flow aloft but also an open
Gulf of Mexico flow at the low levels. Instability looks marginal
at best and will continue what previous shifts have done, and
maintain the thunder-free rain probabilities for Tuesday and Tuesday
night. Moisture rapidly gets shunted off to the east by Wednesday
but low level moisture is slower to clear out and may result in a
small window for very light pcpn early in the day. Dry weather is
then expected for Thursday with surface high pressure in control.
Daytime max temps thru this period will remain above average, even
after the cold FROPA on Wednesday, with the building high pressure
into Thursday is a milder Pacific airmass and not a chillier Canadian
one.
TES
&&
.AVIATION... (For the 06z TAFs through 06z Friday Night)
Issued at 1141 PM CST Thu Nov 17 2016
Latest estimated wind data from KLSX is showing a south southwest
low level jet 1000-2000ft AGL that will likely cause LLWS through
mid morning at all of the terminals. Scattered showers and
thunderstorms are still expected to develop ahead of a cold front
that will move across the area on from west to east on Friday
which will cause winds to shift from south to west behind fropa.
MVFR ceilings and visibilities will be possible with showers and
thunderstorms. Still do not have enough confidence to go with
move than just VCTS at this point in the terminals...though do
expect these conditions will be more widespread across southeast
Missouri and southern Illinois.
SPECIFICS FOR KSTL:
A 40 knot low level jet will cause LLWS through mid morning Friday.
Scattered showers and thunderstorms are still expected to develop
by midday on Friday that could affect the terminal. Do not have
enough confidence to go with more than just VCTS at this point.
MVFR ceilings and visibilities will be possible with showers and
thunderstorms. A cold front will pass through the terminal early
in the afternoon that will cause winds to shift from south to
west.
Britt
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...None.
IL...None.
&&
$$
WFO LSX
Area Forecast Discussion
National Weather Service Omaha/Valley NE
321 AM CST Fri Nov 18 2016
.SHORT TERM...(Today through Sunday)
Issued at 320 AM CST Fri Nov 18 2016
Headlines for winter weather and winds will be the main focus in
the short term. Will leave previously issued highlights as is for
now, but the winter headlines will probably need to be adjusted
later today. We still look for possibly five inches of snow or
more in our northwest counties, and a fairly fast decrease in
amounts southeast of a line from about Platte county to Thurston
county.
Main features from the 00Z upper air maps included the following.
At 300 mb...southeast winds of around 90 to 100 knots extended
from southwest Kansas up into southern Minnesota. At 500 mb...a
closed low was forming over northeast Colorado and 12 hour height
falls of up to 110 meters were noted over western Kansas. A fairly
tight thermal gradient was in place at the 700 mb level from the
Four Corners region into the Northern Plains. The zero degree
isotherm at 850 mb stretched from eastern South Dakota into
central Nebraska, then into northwest Kansas. The KOAX sounding
from 00Z was fairly moist overall, with a PW of 0.74 inches but
there was a dry layer from about 850 mb to 550 mb. Water vapor
satellite loop in combination with recent RAP model
initializationsshowed that the closed mid tropospheric low had
moved into central Nebraska as of 09Z. Surface analysis had a low
pressure over northwest Missouri, with a cold front extending
south into Oklahoma at 09Z.
Today...precipitation will continue through at least mid morning,
heaviest across our northern counties. But that precipitation will
be decreasing later today, as the main forcing lifts northeast
toward the Great Lakes region. Strong winds should occur much of
the day, so will leave the wind advisory headline in effect for
areas outside of the winter headlines. Winds are expected to
decrease tonight, especially after midnight, as a ridge of high
pressure at the surface builds in from the west. With winds
decreasing and clouds clearing, have gone with lows in the teens
where we expect there to be some snowcover tonight. That cold
start should only allow highs to reach 35 to 40 in our northwest
counties but lower and mid 40s elsewhere, even with sunny to
partly cloudy skies.
Dry weather is expected to continue into Sunday and southerly flow
will strengthen. Highs should reach the upper 40s and lower 50s
south and in the 40s north.
.LONG TERM...(Sunday night through Thursday)
Issued at 320 AM CST Fri Nov 18 2016
A 500 mb ridge should stretch from Texas up into Alberta and
Saskatchewan at the start of this period, and a shortwave trough
will be along with west coast. There is some model agreement that
a trough will be over Wyoming and Colorado by Monday night, then
move off to our east by early Wednesday. But there are differences
with the strength of the system and resultant QPF. Will go with a
chance of rain most areas from Monday night through Tuesday
evening, but a mix of rain and snow could occur in our northern
counties late Monday night into Tuesday morning. The chance for
any snow accumulation seems fairly low at this time.
Temperatures next week will be a lot closer to normal, compared to
the last several weeks. Highs should be mainly in the 40s and 50s,
with lows in the 20s and 30s.
&&
.AVIATION...(For the 06Z TAFS through 06Z Friday night)
Issued at 1128 PM CST Thu Nov 17 2016
Showers and isolated thunderstorms are rapidly overspreading
northeast Nebraska as of 0530z with a change over to all snow
anticipated by 10z at KOFK. Expect IFR ceilings to prevail there
through 12z with winds strengthening from the northwest at 25 kts
with gusts to 35 kts. Precipitation should end by mid morning at
KOFK with ceilings lifting to MVFR by early afternoon. At KOMA and
KLNK, precipitation coverage and duration remain much more in
question. Therefore, have opted only only include a VCSH mention
at this juncture. Ceilings should gradually fall to MVFR overnight
before rising to VFR by late morning at KLNK and late Friday
afternoon or early evening at KOMA. Similar to KOFK, winds will
strengthen from the northwest at 25 kts with gusts to 35 kts and
continue through the day.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...Wind Advisory from 6 AM this morning to 6 PM CST this evening
for NEZ015-033-034-043>045-050>053-065>068-078-088>093.
Winter Weather Advisory until 6 PM CST this evening for NEZ018-
030>032-042.
Winter Storm Warning until 6 PM CST this evening for NEZ011-012-
016-017.
IA...Wind Advisory from 6 AM this morning to 6 PM CST this evening
for IAZ043-055-056-069-079-080-090-091.
&&
$$
SHORT TERM...Miller
LONG TERM...Miller
AVIATION...Mead
Area Forecast Discussion
National Weather Service Shreveport LA
1137 PM CST Thu Nov 17 2016
.AVIATION...
VFR conditions tonight is anticipated to quickly deteriorate
overnight ahead of an approaching cold front. MVFR-IFR cigs across
the terminals with a brief period of MVFR-IFR fog developing at
klfk. Fog potential at the remaining terminals looks dismal given
south to southeast surface wind speeds expected to stay up in the
10-13 kt range overnight. Associated with the cold front will be
increasing chances for -SHRA/-TSRA commencing across the western
terminals of kggg, klfk and ktyr a few hours after sunset,
spreading eastward to keld and kmlu by late afternoon/early
evening. A wind shift to the west and eventual northwest will
occur after the cold frontal passage, with speeds staying slightly
breezy /10-12 kts/. Towards the end of this TAF period, conditions
will improve to VFR at kshv, ktxk, kggg, ktyr and klfk as the
precipitation shifts east. The remaining terminals /keld and kmlu/
will improve to VFR just beyond the scope of this TAF cycle.
&&
.PREV DISCUSSION... /issued 940 PM CST Thu Nov 17 2016/
DISCUSSION...
Cold front moving into OK panhandle and lacking in nocturnal
convection thus far. Areal 0z soundings quite dry across the
south, and even very marginal for any convection at KOUN sounding.
HRRR is still in line with chance of late night pops north of I-30
so will not change pops. However, adjusted eastern CWA overnight
lows upwards at least a couple of degrees as south winds and
dewpoint trends suggest overnight lows to remain above 60 degrees
across most of north-central LA and sw AR./VII/.
PREV DISCUSSION... /issued 240 PM CST Thu Nov 17 2016/
DISCUSSION...
Another very unseasonable warm mid November day with current
temperatures a degree or two either side of 80 degrees once again.
All that will come crashing to a halt with the arrival of a
strong cold front moving through our region on Friday...bringing
with it showers and thunderstorms and an end to these well above
normal temperatures.
Strong pressure gradient currently in place across the entire Four
State region ahead of our upper level storm system which is
currently across the Inter Mountain West. Strongest winds by far
today have remained across our far western counties across
Northeast Texas and Southeast Oklahoma. Current Lake Wind Advisory
goes until 4 pm across these counties and will allow it to expire
on time. Upper trough axis begins to push into the Plains
overnight tonight with moderate to strong PVA pushing eastward
into Eastern Oklahoma/North Texas Friday morning. Should begin
seeing a broken line of showers and thunderstorms developing
across this region between midnight and sunrise Friday morning
with this line slowly moving eastward into our region during the
post sunrise hours Friday morning.
Ingredients for severe thunderstorms are not spectacular as the
best dynamics associated with the trough will be north of our
region. However...our area should see the greatest instability
with MLCAPE ranging from 250-750 J/KG with Deep Layer shear in the
vicinity of 30-40kts. Low level shear is weak as flow should begin
veering just ahead of the line of storms on Friday. All this to
say that we cannot rule out a strong to severe thunderstorm with
thunderstorm wind gusts being the main threat followed by a hail
threat but at this time...widespread severe thunderstorms does not
appear likely.
Expecting much colder temperatures behind the front along with
strong northwest winds that could approach post frontal Lake Wind
Advisory Criteria Friday Afternoon across some areas before winds
try to decouple Friday Night. Rainfall amounts are not great...but
we will take anything we can get given the increasing drought
conditions across most of our region and the current Burn Bans in
place. We will approach freezing temperatures across our portions
of Southeast Oklahoma and Southwest Arkansas early Saturday
Morning despite the winds staying up which is a true nature of the
strong Cold Air Advection our area will be dealing with behind
this cold front.
Saturday...while sunny...will be a chilly one with temperatures
struggling to reach the 60s by afternoon which coupled with strong
northerly winds will make it feel even colder. A 1035mb sfc ridge
axis will quickly move our way Sat Night/Sun Morning and this will
result in these winds quickly decoupling and becoming near calm
across much of the region. While there may be some thin cirrus
across Eastern Oklahoma and Central Arkansas...it should not
influence ideal radiational cooling conditions which means that
much of our region should see its first freeze of the fall season
Saturday Night/Sunday Morning. We will likely be issuing Freeze
Warnings for the region for this period as the weekend approaches.
As fast as the sfc ridge gets here Sat Night...its east of us Sun
Night/Mon Morning but not before our eastern zones could see
freezing conditions again during this period.
The upper pattern appears to be becoming more progressive through
much of next week with at least 2 additional troughs fcst to
influence our region...the first on Tue and perhaps another one on
Black Friday. This more progressive pattern should result in less
prolonged warming trends with of course better chances of rain
with the arrival of each trough.
Thanks for the coordination this aftn...FWD...TSA...JAN. Prelims
to follow...13.
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 64 74 41 61 / 10 80 0 0
MLU 62 80 42 61 / 10 80 70 0
DEQ 61 67 32 59 / 40 80 0 0
TXK 64 69 37 60 / 30 80 0 0
ELD 61 74 36 60 / 10 80 0 0
TYR 65 68 39 60 / 20 80 0 0
GGG 64 70 39 61 / 20 80 0 0
LFK 63 76 41 63 / 10 70 0 0
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...None.
LA...None.
OK...None.
TX...None.
&&
$$
29/07/13
Area Forecast Discussion
National Weather Service SAN ANGELO TX
1123 PM CST Thu Nov 17 2016
.AVIATION...
/06Z TAFS/
MVFR cigs are noted on satellite, developing rapidly across the
Hill Country and spreading northwest. Latest model data suggests
the low clouds should make it to a line roughly from San Angelo to
Abilene (KSJT to KABI) during the early morning hours, and then
run into the advancing cold front. Cold front will surge south and
eventually clear all of the area shortly after sunrise. Models
suggest a few showers possible across the southern terminals, but
coverage should be spotty and short lived. Gusty north winds for
all areas for Friday, with gusts over 25 knots likely.
&&
.PREV DISCUSSION... /issued 533 PM CST Thu Nov 17 2016/
AVIATION...
/00Z TAFS/
VFR conditions continue across West Central Texas, although a
shield of high cloudiness is working its way across the area. The
high resolution data suggests that MVFR cigs will make a run into
portions of the area overnight, perhaps as far north as KSJT (San
Angelo) ahead of the strong cold front. The front should reach
KABI (Abilene) shortly after midnight and then clear the rest of
the terminals by around sunrise. Showers and a few storms are
possible along the front, but should remain brief and not very
widespread. Gusty north winds to be the main issue for Friday.
PREV DISCUSSION... /issued 320 PM CST Thu Nov 17 2016/
SHORT TERM...
(Tonight and Friday)
Main concern for tonight is the threat for thunderstorms in the
Northwest Hill Country as the cold front approaches. Latest NAM12
model soundings show decent Most Unstable CAPE values for this time
of year between 09z and 12z. The values ranged from 1500 to 1700
J/KG near Junction with dewpoints in the low to mid 60s, but the CIN
of -30 to -50 may be enough to sustain the capping inversion. HRRR
and the Texas Tech WRF show a fine line of precipitation forming,
but nothing of consequence.
At any rate, if a storm can break through the CAP, it could produce
an isolated strong thunderstorm, with some small hail and gusty
winds tomorrow morning, mainly along and southeast of a line from
San Saba to Mason to Junction. Will highlight this threat in the
Hazardous Weather Outlook. Have continued the trend of chance Pops
for the Northwest Hill Country.
The cold front should slide across the area between Midnight and 6
AM tonight, sweeping the low level moisture east and ushering in
cool and breezy north winds to the region tomorrow. Highs on Friday
will only climb into the upper 50s north to the low to mid 60s
south.
LONG TERM...
(Friday Night through Sunday)
As surface high pressure settles over the area this weekend along
with a dry airmass, ideal radiational cooling will be in place
Friday and Saturday nights, especially south of the I-20
corridor. The MEX guidance is still indicating lows in the upper
20s to lower 30s across across the Northwest Hill Country and
Heartland on west along the I-10 corridor by Sunday morning. The
first freeze of the season may be possible across these areas.
Going with lows in the lower to mid 30s, with upper 20s possible
Sunday morning, especially low lying areas and river valleys.
Going to continue the SPS for possible freezing temperatures and
areas of frost. Highs will be in the upper 50s to mid 60s.
(Sunday Night through Thursday)
For early next week, expect a warming trend and mainly a dry
forecast. A few showers and thunderstorms are possible Tuesday
across the Big Country and Heartland. The temperatures will be
little cooler Wednesday due to the passage of a cool front. Also,
expect gusty south to southwest winds on Tuesday. Highs will be in
the upper 60s to mid 70s, with lows in the 40s and 50s.
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 51 60 34 57 / 10 0 0 0
San Angelo 53 62 35 59 / 20 5 0 0
Junction 58 65 35 60 / 20 30 0 0
Brownwood 55 61 36 57 / 30 10 0 0
Sweetwater 49 58 34 56 / 5 0 0 0
Ozona 51 61 34 58 / 10 5 0 0
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
07
Area Forecast Discussion
National Weather Service North Platte NE
545 AM CST Fri Nov 18 2016
.SYNOPSIS...
Issued at 326 AM CST Fri Nov 18 2016
At 09z...The upper closed low was centered near Kearney Nebraska. A
broad area of light to moderate snow continued across much of
Nebraska into central and eastern South Dakota. temperatures mainly
in the upper 20s in western Nebraska with northwest winds 25 knots
gusting to 35 knots in some areas.
A cold front has advanced through western Nebraska with northerly
winds of 10 to 20 mph and temperatures in the low to mid 40s.
Snowfall occurring over portions of Montana, Wyoming, and Utah.
&&
.SHORT TERM...(Today and tonight)
Issued at 326 AM CST Fri Nov 18 2016
Today...The winter storm has brought widespread snowfall amounts of
3 to 5 inches to most of western Nebraska, while new snowfall will
accumulate across the eastern half of the forecast area this
morning. Forecast storm total snow amounts look close to observed so
far. Northwest winds have increased with recent gusts now as high as
35 knots at LBF, and this is causing considerable blowing snow.
The winter storm system is beginning to lift out of southwestern
portions of the forecast area. A well development deformation band
extends south from near Newport through Brewster to Callaway. The
RAP13 and HRRR both indicated this band will fill in and rotate
northeast early this morning, exiting the forecast area by 18z.
Likely to definite pops beginning at 12z from east of Springview
through Burwell. Up to 1.5 inches of new snow these areas with only
a dusting up to an inch to the west from Valentine thorugh Broken
Bow. The existing Winter Storm Warning and Winter Weather Advisory
will continue until 18z with impacts from blowing snow to continue
this morning across the west. The winter Storm Warning to continue
across the northeast zones this afternoon as impacts from blowing
snow may continue.
The northwest winds will begin to diminish by mid afternoon.
Although mostly sunny skies will return to the west, a widespread
blanket of snow across the region will limit high temperatures.
Highs were lowered slightly below model guidance, from 30-32 north
central, to 33-36 across the south.
Tonight...Mainly clear skies this evening, then increasing high
cloudiness after midnight as the upper ridge axis builds across the
Central Rockies. Went below previous forecast lows a few degrees to
the upper single digits to low teens most areas. Winds chills will
fall into the low single digits in most areas late this evening
and overnight.
.LONG TERM...(Saturday through Thursday)
Issued at 326 AM CST Fri Nov 18 2016
Upper level ridging aloft will dominate the weather Saturday through
Monday. Highs will gradually warm from 35 to 45 degrees Saturday to
48 to 58 degrees by Monday. The cooler readings will be across
eastern portions of north central Nebraska, with the warmer readings
across southwest and western Nebraska.
Another system is slated to move across the area Tuesday. This will
be another quick moving system, but is expected to pack somewhat of
a punch with decent upper level dynamics crossing the area. Still
appears temperatures aloft will be several degrees warmer than what
is occurring with this current system, and most of the precipitation
will fall as rain. Some wet snow is possible, but little if any
impact is expected from the snow at this time. As mentioned this
will be a quick moving system, with upper level ridging and warmer
weather returning for Wednesday and Thanksgiving.
&&
.AVIATION...(For the 12Z TAFS through 12Z Saturday morning)
Issued at 545 AM CST Fri Nov 18 2016
As a winter storm system moves into the western Great Lakes
today, it will produce winds 33022G31KT today to the klbf and kvtn
terminals. There remains light snow at kvtn along with MVFR
ceilings near bkn015. The snow will end soon after 12z with
ceilings quickly becoming VFR for the remainder of the taf period.
The winds across western Nebraska will quickly diminish by 23z to
at or below 10 kts.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory until noon CST /11 AM MST/ today for
NEZ022-056>058-069>071.
Winter Storm Warning until noon CST /11 AM MST/ today for NEZ004-
005-023>026-035>038-059-094.
Winter Storm Warning until 6 PM CST this evening for NEZ006>010-
027>029.
&&
$$
SYNOPSIS...Roberg
SHORT TERM...Roberg
LONG TERM...Taylor
AVIATION...Roberg
Area Forecast Discussion...Updated Aviation
National Weather Service Saint Louis MO
552 AM CST Fri Nov 18 2016
.SHORT TERM... (Through Late Tonight)
Issued at 340 AM CST Fri Nov 18 2016
An upper level trough centered over south central Nebraska and an
associated developing surface low over northwestern MO with a
trailing cold front extending southwest into central OK will move
eastward through our forecast area today. Upper level divergence
will ramp up over our area this morning ahead of the upper level
trough. A band of showers should develop and move through parts of
northeast and central MO this morning, then the intensity and
coverage of the precipitation should increase late this morning and
this afternoon just ahead of the cold front across east central and
southeast MO and southwest IL as the atmosphere destabilizes. The
HRRR model depicts thunderstorms across southeast MO and southwest
IL this afternoon. Could not rule out a few severe storms with
damaging winds. This will be a low CAPE/high shear environment with
a 70-80 knot mid level jet streak moving through the area. Strong
low level cold air advection behind the cold front will lead to
falling temperatures late this morning across northeast and central
MO and across the rest of our area this afternoon. The wind will be
strong and gusty again today due to a tight surface pressure
gradient. It appears that most of the convection will shift
southeast of our forecast area by early evening as the cold front
shifts southeast of the area with low level cooling and drying
behind the cold front as a strong 1035-1040 mb surface ridge builds
southeastward into our region behind the cold front. Much colder
temperatures are expected tonight with decreasing cloudiness from
southwest to northeast later this evening and overnight. The 850 mb
temperature will drop down to around 6 degrees below zero C in STL
by midnight tonight. Although the low temperatures tonight will only
be a couple of degrees below normal it will feel cold after the
unseasonably warm weather of the past two days, plus winds will be
relatively strong for the nighttime hours. Lows will be below 32
degrees across parts of northeast and central MO into the Ozarks and
also in west central IL.
GKS
.LONG TERM... (Saturday through Thursday)
Issued at 340 AM CST Fri Nov 18 2016
(Saturday - Monday)
A quiet period of wx is expected with slowly warming temperatures.
Northwest flow aloft will prevail and be disturbance free in a
largely dry column. The coolest day will be Saturday in the wake
of the departing storm system in a brisk NW surface flow, but temps
will only be relatively cool as forecast high temps will be a mere 5
degrees below average. By Monday, with the surface RIDGE to our
east, temps will have recovered some to where daytime max temps are
expected to be about 5 degrees above average.
(Tuesday - Thursday)
The lone pcpn event during this stretch is slated to occur towards
the middle of next week with flow aloft switching from the southwest
and upper level disturbances quickly follow. Moisture return should
be significant with not just a favorable flow aloft but also an open
Gulf of Mexico flow at the low levels. Instability looks marginal
at best and will continue what previous shifts have done, and
maintain the thunder-free rain probabilities for Tuesday and Tuesday
night. Moisture rapidly gets shunted off to the east by Wednesday
but low level moisture is slower to clear out and may result in a
small window for very light pcpn early in the day. Dry weather is
then expected for Thursday with surface high pressure in control.
Daytime max temps thru this period will remain above average, even
after the cold FROPA on Wednesday, with the building high pressure
into Thursday is a milder Pacific airmass and not a chillier Canadian
one.
TES
&&
.AVIATION... (For the 12z TAFs through 12z Saturday Morning)
Issued at 454 AM CST Fri Nov 18 2016
Cold front extending from surface low over southwestern IA
south-southwest through western MO and eastern OK will move east
southeastward through the taf sites today. A relatively fast
moving line of showers and storms is along this front. The best
coverage of showers and storms should occur in the St Louis metro
area late this morning and early this afternoon. The prevailing
cloud ceiling may also drop into the MVFR catagory. A southwest
low level jet will continue to bring low level wind shear
conditions to the taf sites early this morning with southwest
winds at 2000 feet in height around 45 knots. Strong and gusty
southerly surface winds this morning will veer around to a
westerly direction this afternoon after fropa. Strong and gusty
northwesterly surface winds can be expected tonight as a surface
ridge builds into the area behind the cold front. Low level, VFR
post frontal cloudiness can be expected tonight.
SPECIFICS FOR KSTL: Cold front extending from surface low over
southwestern IA south-southwest through western MO and eastern OK
will move east southeastward through the STL area around 18Z
today. A relatively fast moving line of showers and storms is
along this front. Showers and storms can be expected late this
morning and early this afternoon. The prevailing cloud ceiling may
also drop into the MVFR catagory. A southwest low level jet will
continue to bring low level wind shear conditions to STL early
this morning with southwest winds at 2000 feet in height around 45
knots. Strong and gusty southerly surface winds this morning will
veer around to a westerly direction this afternoon after fropa.
Strong and gusty northwesterly surface winds can be expected
tonight as a surface ridge builds into the area behind the cold
front. Low level, VFR post frontal cloudiness can be expected
tonight. These clouds will clear out early Saturday morning.
GKS
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...None.
IL...None.
&&
$$
WFO LSX
Area Forecast Discussion
National Weather Service Marquette MI
650 AM EST Fri Nov 18 2016
.SHORT TERM...(Today and tonight)
Issued at 509 AM EST FRI NOV 18 2016
WV imagery and RAP analysis indicated a vigorous negatively tilted
shortwave trough lifting northeast through ern Nebraska. At the
surface, low pressure was located over sw IA with a trough
extending to the northeast into wrn WI. An area of rain over nw WI
and wrn Lake Superior into ne MN was supported by 300k isentropic
lift and increasing moisture advection in the 850-700 mb frontal
zone ahead of the low. Otherwise, abundant low level moisture and
low clouds/fog prevailed over west/cntrl Upper Michigan to the
north of a warm front from cntrl WI into nrn lower MI.
Today, expect the rain to gradually expand over the west as the
shortwave and low pres lift to the northeast. The strongest 700-300
mb qvector conv ahead of the shrtwv will reach the area late today
with the rain area finally expanding into the cntrl areas by mid to
late afternoon. Despite the thick clouds, temps will remain well
above normal with highs in the mid to upper 50s cntrl and east.
Tonight, the low pressure center into west cntrl Upper Michigan
around 00z is only slowly expected to lift into Lake Superior by 06z
and to the se end of the lake by 12z. Expect a lull in the pcpn over
much of the cwa, as the dry slot takes over cntrl and east during
the evening. Then, winds will quickly increase as the strong
isallobaric component with 3 hr pres rise of 7mb develops with the
deepening low. So, expect a rapid temp drop and changeover to snow
from west to east btwn 03z- 09z. Even through the strongest dynamics
with the mid level trough will move off to the northeast, lake
enhanced snow will become heavy over the west and then the cntrl
late, especially in upslope flow locations, as 850 mb temps drop to
-12c and nrly 925 mb winds increase to 50-60 knots. So, winter storm
warning headlines for the combined hazards of highs winds and hazards
with sn/blsn and poor driving conditions were issued with winter wx
advisories beginning farther inland.
.LONG TERM...(Saturday through Thursday)
Issued at 424 AM EST FRI NOV 18 2016
Main fcst concerns in the medium range period wl be on potent lo
pres fcst to impact the area on Sat with hi winds, hi waves near Lk
Sup, as well as some lk enhanced snow. Although the cold airmass
following the departing lo wl feature some marginally blo normal
temps, the contrast with the recent warmth wl make the change feel
more sgnft. Another lo pres passing thru the Lower Lks may bring
more mixed pcpn late on Tue thru Wed.
Sat...Deep sfc lo pres over ern Lk Sup at 12Z Sat wl tend to slide
slowly to the se and over nrn Lk Huron by 00Z Sun as a shrtwv moving
e thru the Lower Lks intensifies the upr trof stretching fm Upr MI
to near Detroit and also due to the impact of lk warming of the cold
airmass surging into the area that wl tend to support lowering mslp.
H925 nnw winds up to 50 kts under the sharp pres gradient on the wrn
flank of the sfc lo pres wl impact the e half of Upr MI most of the
day and draw h85 temps as lo as -15C over the wrn cwa by 00Z Sun.
The strong caa wl enhance mixing of the strong winds to the sfc, and
result in wind gusts at least aprch wrng thresholds near Lk Sup. The
best chc for the stronger winds wl be at exposed locations near Lk
Sup over the Keweenaw and e of about Marquette, where the pres
gradient/h925 winds are fcst to be the strongest and where a sharper
isallobaric wind component to the s of an intense 14mb/6 hr pres
rise center to the nnw of the sfc lo pres wl enhance the wind speeds.
These strong winds wl also whip up waves aoa 20 ft at exposed
locations along the shore...resulting in some shoreline flooding/
beach erosion. The combination of the sharp cyc flow and decreasing
stability over Lk Sup, where water temps are still arnd 8C, wl
result in some lk enhanced les, especially where the strong nnw flow
upslopes downwind of Lk Sup. The strong winds and local warming
along Lk Sup wl likely result in the heavier sn falling a bit
farther inland than is typical. Deep dgz shown on fcst sdngs within
the area of hier mstr would enhance snow accums further, but the
strong winds might tend to break up the resulting larger flakes and
thus limit this potential. This enhancement wl tend to diminish over
the w half thru the day as dnva/deep lyr qvector dvgc in the wake of
the slowly exiting upr trof axis overspreads the area and lowers the
invrn base toward 4k ft agl. Expect as much as 3 to 5 inches of sn
on Sat over the ncentral to less than an inch over the far scentral,
where the llvl flow wl downslope. Blowing snow wl also be an issue.
But as the dayshift pointed out, lingering dead vegetation/absence
of prior snow cover wl probably limit the intensity of the blowing
snow.
Sat ngt...As the upr trof axis shifts to the e, sharp dnva/deep lyr
qvector dvgc/subsidence wl overspread the e and cause the invrn
there to subside toward 3-4k ft agl, resulting in diminishing les
intensity in that area. But persistence of h85 temps as lo as -15C
and h85-lk water temp contrast in excess of 20C under llvl cyc nnw
flow wl cause lighter les to persist in the favored sn belts. The
slowly weakening cyc flow and passage of pres rise center to the se
as the sfc lo pres exits to sw Quebec wl result in diminishing winds
even over the e.
For headlines, opted to upgrade winter storm watch for Gogebic/
Ontonagon Counties and hi wind watches for the Keweenaw and
Marquette/Alger/Lue to winter storm warnings. While hi winds at
least aprchg wrng criteria wl be the main threat for
Marquette/Alger/ Luce, snow accums at aoa advy criteria in some of
these areas warrant a winter storm mention. Also included some
winter wx advys for inland areas to account for wind gusts near advy
criteria along with some snow/blowing snow. Went with a marginal
wind advy for Menominee/Dickinson Counties as well.
Sun/Sun ngt...The aprch of trailing sfc hi pres/more acyc llvl flow/
warming h85 temps as the invrn lowers further wl tend to end the les
w-e over at least the w half on Sun/Sun ngt. This pcpn wl be most
tenacious to the e of Marquette, where a steadier nnw flow wl
persist under h85 thermal trof near -12C. If there is some clrg of
the lo clds over the interior w as the sfc hi pres rdg moves nearly
ovhd, the light acyc flow/pwat aob 0.25 inch would allow temps to
fall well into the teens.
Mon/Mon ngt...Hi pres rdg under aprch shrtwv rdg axis wl bring a dry
period of wx even if some clds linger near Lk Sup in those areas
impacted by light upslope nne flow. More hi clds wl arrive fm the w
on Mon ngt as next shrtwv over the scentral Plains lifts to the ne
toward the wrn Great Lks.
Tue thru Fri...Some of the longer range models, especially the 00Z
GFS, have trended deeper with the next shrtwv lifting newd out of
the central Plains on Tue and into the Great Lks on Wed. The GFS
shows a more negatively tilted disturbance, with a deeper sfc lo
farther to the nw resulting in some mixed pcpn beginning late on
Tue. The 00Z ECMWF indicates a somewhat weaker disturbance passing
farther to the s, with mainly snow as ptype. After a period of dry
wx on Thanksgiving with trailing sfc hi pres passing thru the wrn
Great Lks, another disturbance may bring some light rain and snow to
the area on Fri.
&&
.AVIATION...(For the 12Z TAFS through 12Z Saturday morning)
Issued at 649 AM EST FRI NOV 18 2016
Overall, expect conditions to remain low in the LIFR/VLIFR category
into this evening as moisture surges into the area ahead of a strong
low pressure system. Fog will continue this morning, and will be
most extensive at KSAW where upslope forcing will be strongest. Rain
will change over to snow at IWD this evening, at CMX overnight and
at SAW early Saturday morning and will become moderate to heavy at
times. North winds will become gusty to near 40 knots as the low
moves away leading to blsn.
&&
.MARINE...(For the 4 AM Lake Superior forecast issuance)
Issued at 509 AM EST FRI NOV 18 2016
A strong storm system over IA this morning will move through Lake
Superior tonight and to the east of the area Saturday. Prolonged
storm/gale event are expected. NE gales will increase to storm today
over the west. Winds will become nnw this afternoon into tonight
with storm force winds spreading into the east half of the lake.
The most intense winds will be just behind the compact deepening low
as it moves through and out of the area. The high winds will also
quickly build waves into the 14 to 17 ft range over the western lake
today, then 14 to 22 ft late tonight into early Saturday with waves
gradually subsiding late Saturday into Saturday night. See marine
forecasts and hazards statements for more information.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
Winter Weather Advisory from 1 AM EST /midnight CST/ to 4 PM EST
/3 PM CST/ Saturday for MIZ004-010-084.
Winter Weather Advisory from 7 AM Saturday to 1 AM EST Sunday
for MIZ013-014-085.
Winter Storm Warning from midnight tonight to 7 PM EST Saturday
for MIZ001-003.
Winter Storm Warning from 7 PM EST /6 PM CST/ this evening to 4
PM EST /3 PM CST/ Saturday for MIZ002-009.
Coastal Flood Warning from 7 AM Saturday to 1 AM EST Sunday for
MIZ006.
Winter Storm Warning from 5 AM Saturday to 1 AM EST Sunday for
MIZ006.
Coastal Flood Warning from 10 AM Saturday to 1 AM EST Sunday for
MIZ007.
Winter Storm Warning from 7 AM Saturday to 1 AM EST Sunday for
MIZ007.
Coastal Flood Warning from 4 AM to 7 PM EST Saturday for MIZ005.
Winter Storm Warning from 3 AM to 10 PM EST Saturday for MIZ005.
Wind Advisory from 6 AM to 3 PM CST Saturday for MIZ011-012.
Lake Superior...
Storm Warning from 7 AM to 4 PM EST Saturday for LSZ251-267.
Storm Warning from 1 AM to 4 PM EST Saturday for LSZ249-250-266.
Gale Warning until 7 PM EST this evening for LSZ243-244-264-266.
Storm Warning from 1 AM to 1 PM EST Saturday for LSZ245-248-265.
Gale Warning until 1 PM EST this afternoon for LSZ245-265.
Storm Warning from 10 PM this evening to 1 PM EST Saturday for
LSZ243-244-264.
Gale Warning until 1 AM EST Sunday for LSZ246-247.
Storm Warning until 7 AM EST /6 AM CST/ Saturday for LSZ162-
240>242-263.
Gale Warning from 7 AM EST /6 AM CST/ to 7 PM EST /6 PM CST/
Saturday for LSZ240>242-263.
Gale Warning from 7 AM EST /6 AM CST/ to 4 PM EST /3 PM CST/
Saturday for LSZ162.
Lake Michigan...
Gale Warning from 1 PM this afternoon to 1 AM EST Sunday for
LMZ221-248-250.
&&
$$
SHORT TERM...JLB
LONG TERM...KC
AVIATION...JLB
MARINE...JLB
Area Forecast Discussion
National Weather Service Omaha/Valley NE
603 AM CST Fri Nov 18 2016
.SHORT TERM...(Today through Sunday)
Issued at 320 AM CST Fri Nov 18 2016
Headlines for winter weather and winds will be the main focus in
the short term. Will leave previously issued highlights as is for
now, but the winter headlines will probably need to be adjusted
later today. We still look for possibly five inches of snow or
more in our northwest counties, and a fairly fast decrease in
amounts southeast of a line from about Platte county to Thurston
county.
Main features from the 00Z upper air maps included the following.
At 300 mb...southeast winds of around 90 to 100 knots extended
from southwest Kansas up into southern Minnesota. At 500 mb...a
closed low was forming over northeast Colorado and 12 hour height
falls of up to 110 meters were noted over western Kansas. A fairly
tight thermal gradient was in place at the 700 mb level from the
Four Corners region into the Northern Plains. The zero degree
isotherm at 850 mb stretched from eastern South Dakota into
central Nebraska, then into northwest Kansas. The KOAX sounding
from 00Z was fairly moist overall, with a PW of 0.74 inches but
there was a dry layer from about 850 mb to 550 mb. Water vapor
satellite loop in combination with recent RAP model
initializationsshowed that the closed mid tropospheric low had
moved into central Nebraska as of 09Z. Surface analysis had a low
pressure over northwest Missouri, with a cold front extending
south into Oklahoma at 09Z.
Today...precipitation will continue through at least mid morning,
heaviest across our northern counties. But that precipitation will
be decreasing later today, as the main forcing lifts northeast
toward the Great Lakes region. Strong winds should occur much of
the day, so will leave the wind advisory headline in effect for
areas outside of the winter headlines. Winds are expected to
decrease tonight, especially after midnight, as a ridge of high
pressure at the surface builds in from the west. With winds
decreasing and clouds clearing, have gone with lows in the teens
where we expect there to be some snowcover tonight. That cold
start should only allow highs to reach 35 to 40 in our northwest
counties but lower and mid 40s elsewhere, even with sunny to
partly cloudy skies.
Dry weather is expected to continue into Sunday and southerly flow
will strengthen. Highs should reach the upper 40s and lower 50s
south and in the 40s north.
.LONG TERM...(Sunday night through Thursday)
Issued at 320 AM CST Fri Nov 18 2016
A 500 mb ridge should stretch from Texas up into Alberta and
Saskatchewan at the start of this period, and a shortwave trough
will be along with west coast. There is some model agreement that
a trough will be over Wyoming and Colorado by Monday night, then
move off to our east by early Wednesday. But there are differences
with the strength of the system and resultant QPF. Will go with a
chance of rain most areas from Monday night through Tuesday
evening, but a mix of rain and snow could occur in our northern
counties late Monday night into Tuesday morning. The chance for
any snow accumulation seems fairly low at this time.
Temperatures next week will be a lot closer to normal, compared to
the last several weeks. Highs should be mainly in the 40s and 50s,
with lows in the 20s and 30s.
&&
.AVIATION...(For the 12Z TAFS through 12Z Saturday morning)
Issued at 550 AM CST Fri Nov 18 2016
MVFR conditions with some occasional IFR/LIFR at KOFK with reduced
visibilities/ceilings with snow and blowing snow this morning. A
few flurries may make it into KLNK or KOMA, however not confident
enought to include. Northwest winds 20-30kt with gusts 30 to
40kts. Ceilings will improve later this afternoon and surface
winds will decrease later tonight.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...Wind Advisory until 6 PM CST this evening for NEZ015-033-034-
043>045-050>053-065>068-078-088>093.
Winter Weather Advisory until 6 PM CST this evening for NEZ018-
030>032-042.
Winter Storm Warning until 6 PM CST this evening for NEZ011-012-
016-017.
IA...Wind Advisory until 6 PM CST this evening for IAZ043-055-056-069-
079-080-090-091.
&&
$$
SHORT TERM...Miller
LONG TERM...Miller
AVIATION...Zapotocny
Area Forecast Discussion
National Weather Service Spokane WA
447 AM PST Fri Nov 18 2016
.SYNOPSIS...
The weather today across the Inland Northwest will be generally
dry with areas of morning fog and low clouds due to a brief visit
of an upper level ridge. The exception to the dry weather could
involve a few flurries near the Cascades. The weather pattern
becomes more active going into the weekend through next week, with
several chances for precipitation. This includes the potential
for occasional winter travel impacts around the mountains and
mountain passes.
&&
.DISCUSSION...
Today...The weather during the next 24 hours will be generally
impacted by the increasing presence of a 500 mb shortwave ridge.
Temperatures at this level will warm almost 10c compared to
yesterday resulting in a much more stable air mass than we have seen
for the last 2 days. In fact, the only residual instability was
associated with a few showers detected by radar over NE Washington
north of a line from Kettle Falls to Ione. These showers should
disappear rapidly as the warmer air aloft continues to surge in from
the southwest. The dendritic layer will also see a rapid desiccation
which will also take a toll on these showers.
While the threat of showers will disappear from most locations
today, a majority of the models continue to forecast some very light
precipitation near the lee of the Cascades. Model cross- sections in
this area continue to show a layer of moisture from the surface to
6000 feet accompanied by weak upslope ascent due to ESE winds into
the crest. This is well below the dendritic layer which for most of
the day will remain dry. This suggests that if the precipitation
really comes to fruition, it will mainly consist of flurries.
Otherwise the main forecast issue today will be the fog and low
clouds which have rapidly filled northern portions of the Columbia
Basin with the departure of some mid-level cloudiness. The HRRR and
NAM have been quite persistent on burning these clouds off early
this morning as the easterly low level winds in this area intensify.
Not sure about this scenario as the fog has formed around Spokane
and Coeur d`Alene despite NE winds up to 10 mph.
For tonight the NE-SW oriented band of moisture seen on IR satellite
off the Oregon coast and associated with a cold front will head
toward the Cascades overnight. This will gradually moisten the
atmosphere, including the dendritic layer which will consequently
result in an increasing chance of precipitation as well as the weak
upslope flow continues into the Cascades.
Snowfall amounts should be light. fx
Saturday through Tuesday night...A closed low off the Washington
coast will send a series of waves into the region this weekend
bringing occasional light rain and mountain snow. Snow levels will
continue to rise. Near the Canadian border snow levels climb from
near 2000 feet Saturday morning to 3000 feet Saturday night to 4500
feet Sunday afternoon. From the Blue Mountains to the Central
Panhandle Mountains snow levels climb from 2500-3500 feet Saturday
morning to 5000-6000 feet by early Sunday. Near the East Slopes of
the Cascades the colder air will be slower to modify...with snow
levels near 1500 feet Saturday morning rising to 2000-3000 feet
Saturday night and Sunday morning before rising to near 4000 feet.
As the trough axis moves inland on Monday snow levels area wide will
be between 4000-5000 feet. A break in the weather will occur Monday
night before the next system spreads an increasing chance of rain
and snow across the area Tuesday into Tuesday night. Precipitation
should be primarily valley rain and mountain snow once
again...although valley rain may mix with snow in the Methow Valley
and near the Canadian border. JW
&&
.AVIATION...
12Z TAFS: Widely varying conditions expected for all the sites this
morning as expansive low clouds and fog will continue over the GEG
SFF COE area. These clouds should primarily deliver IFR conditions
through the morning, but not confident about how long they will
last. Moderate NE winds up to 10 mph should theoretically scour out
the low clouds earlier than usual and models show a breakup for all
these sites by 16z, however this flies against conditional
climatology and consequently we will opt to hold onto the poor
conditions a little bit longer. Suffice it to say confidence is low,
especially at COE where the conditions are varying rapidly despite a
fairly uniform appearance on the fog product. Once the low clouds
break we are quite confident that VFR conditions will prevail
through the remainder of the forecast. VFR conditions will also
prevail at all other sites except EAT as mid/high level clouds
thicken through the period. EAT should maintain fairly consistent
MVFR cigs through much of the morning due to moist upslope flow.
This regime will weaken by afternoon and tonight resulting in
improving conditions. fx
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 43 34 43 36 46 37 / 0 0 60 30 60 50
Coeur d`Alene 44 33 42 36 45 37 / 0 0 70 30 60 60
Pullman 46 36 45 37 49 39 / 0 10 60 40 60 40
Lewiston 50 37 50 38 52 41 / 0 10 50 30 50 40
Colville 44 33 41 35 43 37 / 0 0 70 40 70 40
Sandpoint 42 30 41 36 43 35 / 0 0 80 50 70 60
Kellogg 41 31 42 35 44 36 / 0 0 70 50 60 70
Moses Lake 48 34 48 38 47 35 / 0 20 50 40 50 30
Wenatchee 44 35 43 35 45 37 / 10 20 60 50 50 20
Omak 45 34 42 35 43 36 / 10 10 70 60 70 30
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
Area Forecast Discussion
National Weather Service Cleveland OH
357 PM EST Fri Nov 18 2016
.SYNOPSIS...
Low pressure over the western Great Lakes will move east and reach
Maine by early Sunday. A strong cold front associated with this
low will sweep east across the local area late tonight and early
Saturday. High pressure will begin to build over the region from
the southwest on Sunday.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
Clear skies to begin this evening but clouds will increase from
the west during the evening. Have rain moving into western
counties after 8pm. The nam12 shows capes of 200to 800j.kg get
into the western counties this evening and lightning data shows a
decent amount of lightning along the front in eastern Illinois so
will have a slight chance of thunder west half through the
evening. Temps at 850mb will drop below freezing after 09z in the
western counties so all precip should be rain. will have
categorical pops for all and attempted to move the band of rain
east across the area through the night in the grids. Temps ahead
of the boundary will be quite mild into the night with warm
advection ahead of the system. Used HRRR and rap13 for insight
into hours temps with cold advection moving in from the west after
06z.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY NIGHT/...
Cold air will continue to fill in saturday behind a strong cold
front that will be exiting the area around sunrise.
Initially...slightly drier air and subsidence will fill in behind
the front but wrap around moisture will fill back in during the
day so will keep pops high chance to categorical with best chance
north. Precip type should be all rain to start but -8c air at
850mb fills in quickly from the west during the morning. This
should allow snow to mix in from the west during the morning with
the transition shifting east through the day reaching eastern
counties mid/late afternoon. Accums should not be much of anything
as ground temps will remain above freezing and air temps as well
should remain above freezing through the day. Saturday night most
precip will be snow except possibly over the lake where low level
warmth off the lake will change the snow to rain near the surface.
Based on Bufkit forecast soundings and coordinating with WPS and
surrounding offices...best snow accums should occur across NWRN PA
inland with the lakeshore likely too close to the warm Lake Erie
to accumulate warning criteria snow. Inland however...expect the
event to drop upwards of around a foot in the highest elevations
east. Have issued a Lake Effect Snow Watch. Started it at 21z
Saturday to cover any mix or transition but best chance for lake
effect snow comes after midnight. Lake/850mb instability reaches
extreme and winds stop consistent from the northwest after
midnight Saturday continuing into Sunday night before tapering
early Monday so will continue the watch through Monday morning.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
Cold air will continue to flow across the warmer waters of Lake Erie
on Monday. So this will keep Lake Effect snow showers going through
the day across NE OH in NW PA. They will likely linger the longest
over the higher terrain of inland NW PA. The snow should end at some
point Monday evening as high pressure increases its influence. This
area of high pressure will then become the dominant feature through
Tuesday afternoon. Models are then in good agreement on the movement
of another strong storm system that will emerge from the Southern
Plains. All locations will warm ahead of this low Tuesday into
Wednesday. Locations that do not get significant snow this weekend
will warm to near or slightly above seasonal levels. The cold front
will sweep across the area Wednesday night with another round of
showers. Winds will again increase with this storm system.
&&
.AVIATION /18Z Friday THROUGH Wednesday/...
Low pressure moving into the western Great Lakes will assist in
tightening the surface pressure gradient through the afternoon.
Strongest southerly winds will be across NW Ohio. Overnight winds
will shift to the southwest and eventually the west as a strong
cold front moves into the region. The front will sweep across the
region from west to east through 15z. Showers will develop ahead
of the front with some of them becoming gusty. Gusts to 40+ knots
will be possible. The showers will assist in lower the cloud cover
ahead of the front with MVFR cloud cover expected to spread across
the region in the wake of the front. All precipitation will likely
remain liquid into Saturday afternoon.
OUTLOOK...Non-VFR conditions in showers will change to snow
Saturday night and linger into Monday...primarily across extreme
NE OH and NW PA.
&&
.MARINE...
Strong area of low pressure will move across the western Great Lakes
tonight then redevelop over southern Ontario on Saturday. Expect the
pressure gradient to increase ahead of this storm system tonight but
the strongest winds will develop as the cold front passes. Strong
cold advection in the wake of the front will assist in bringing
stronger winds down to the surface. It appears gale conditions will
develop late Saturday morning into the afternoon then continue into
Sunday. Will go ahead and change the Gale Watch to a Gale Warning
shortly. Winds will decrease Sunday night with an extended period of
small craft conditions expected into Monday night. High pressure
will then briefly take control of the region Monday night into
Tuesday.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...None.
PA...Lake Effect Snow Watch from Saturday afternoon through Monday
morning for PAZ002-003.
MARINE...Gale Warning from 1 PM Saturday to 4 AM EST Monday for LEZ061-
145>149-165>169.
Gale Warning from 10 AM Saturday to 4 PM EST Sunday for
LEZ142>144-162>164.
&&
$$
SYNOPSIS...TK
NEAR TERM...TK
SHORT TERM...TK
LONG TERM...Mullen
AVIATION...Mullen
MARINE...Mullen
Area Forecast Discussion
National Weather Service Grand Rapids MI
255 PM EST Fri Nov 18 2016
LATEST UPDATE...
Synopsis/Short Term/Long Term/Marine
.SYNOPSIS...
Issued at 255 PM EST Fri Nov 18 2016
The very mild weather from the last couple of days will come to a
screeching halt tonight as a strong cold front blows through the
area. This cold front will be accompanied by showers and a few
storms with some gusty winds possible.
Rain showers will then change over to snow showers Saturday morning
as the coldest of the air comes in. Some accumulating snow will be
possible as some heavier bands look possible. 1-3 inches will be
possible southwest and northwest of Grand Rapids. Strong wind gusts
of 40-50 mph will be expected with the highest winds expected along
the lakeshore.
The weather will then gradually quiet down Saturday night and Sunday
and last through the early portion of the week. Another system is
expected to move in for the mid-week time frame.
&&
.SHORT TERM...(This evening through Sunday night)
Issued at 255 PM EST Fri Nov 18 2016
We will not be making any changes to the ongoing headlines or the
updated forecast from earlier with the afternoon package. A wind
advisory remains in effect for the lakeshore for Saturday. We will
be holding off on a possible Winter Weather Advisory for now with
uncertainty as to how much snow can accumulate and the associated
impact to the area.
The leading edge of a few showers and a storm has moved over the NW
portion of the CWFA. The main cold front looks to be located from
Central Wisconsin through Central Illinois as of 19z. More showers
and a few storms extend from Chicago down to the SSW ahead of the
front. We expect that these will move up into the area over the next
few hours. The thunder threat will remain with the strong cooling
aloft with the upper wave moving over the warmer low levels in
place. We believe the biggest threats are a narrow line of wind
gusts of 40-50 mph in the outflow ahead of the showers and storms,
along with a small hail threat.
We will see the dry slot move in then this evening initially behind
the front. The more widespread showers and storms will diminish for
a short time. We will then see the secondary cold front/cold
conveyor belt surge in toward 12z Sat from West to East. We will see
rain showers increase as this occurs. The rain will then change over
to snow fairly soon thereafter as the atmosphere becomes
sufficiently cold. We will then see the winds pick up significantly
at that time. The worst winds look to occur right along the
shoreline.
All areas will see some rain changing over to snow Sat morning.
There will likely be some enhanced bands that take shape as the
lake will become a significant player with over-water instability
increasing to over 20C. The flow will start out W, and shift to NW
fairly quick. This will focus some bands of snow showers to the NW
and SW of Grand Rapids. The only locations that may be limited under
these bands would be right at the lakeshore where the temps will be
moderated some by the 50+F water.
We are still considering an advisory for the potential of some quick
accumulating snow, but remain not confident enough to issue at this
time. The warm weather today will have road temps quite warm and sfc
air temps will be above freezing. Heavier snow rates in the bands
could overcome this, but we are just not sure about how much impact
they will create. Grassy areas should see some accums, but this will
have little to no impact.
We will see the snow diminish quite a bit then Sat evening as the
deep moisture with the low will pull away. The upper low will be
pulling away, and the flow aloft will become anti-cyclonic. Some
residual snow showers will remain, but they should not carry much of
a punch. Any snow covered or wet roads will freeze Sat night as
temps will drop down in the 20s for most areas.
Snow showers will end on Sun, and clouds will likely linger,
especially closer to the lakeshore with a NNW flow. Some clearing
could take place inland Sun night as better ridging builds in.
.LONG TERM...(Monday through Friday)
Issued at 255 PM EST Fri Nov 18 2016
With the polar jet now being farther south we can expect more
frequent precipitation events. Our next event will largely be rain
(could be mixed with snow at the start) in the Wednesday into
Thursday morning time frame. The next system will be moving into the
area early next weekend, which at this point looks more like rain
than snow. Temperatures will be close to normal with highs mostly in
the 40s and lows from 20s to the mid 30s.
As per my discussion yesterday both the GFS and ECMWF ensembles like
the idea of having a negative NAO and AO becoming even more negative
early in December. The PNA (where the upper ridges and troughs are
over NA) goes slightly negative next week only to go positive the
first week of December. This suggests we may turn even colder in
another week. One thing for sure, the significantly warmer than
normal temperatures we have seen for a very long time do seem to
done at least into mid December and likely well beyond that.
The system on Wednesday is another southern stream system which will
allow it to transport Gulf of Mexico moisture into our area. This
will give us a significant precipitation event as a result of that.
The track of the system is significantly farther south than one
passing trough our area now so we do not get south of the warm front
like we did today. Even so we still have forecast precipitable water
values reaching just short of an inch in our southern CWA Wednesday.
It should be wet system for sure. The rain / snow line is well north
with this system so snowfall should not be much of an issue. One
problem with this system is that it does seem to be slowing down.
That suggests it may be raining yet on Thanksgiving morning. There
does not seem to be not much cold air being pulled down behind the
system so I do not expect a change to snow as with the system this
weekend.
Once that system gets out of the area yet another one follows for
next weekend. It too should be a weaker system so as it tracks over
Northern Michigan. This would seem to be another rain event.
Bottom line is cooler and wetter weather expected.
&&
.AVIATION...(For the 18Z TAFS through 18Z Saturday afternoon)
Issued at 1250 PM EST Fri Nov 18 2016
There is currently line of showers and scattered thunderstorms
from north of MKE to CHI to DEC heading east. The question is when
will it reach our TAF sites. The HRRR kills what we see out there
now and redevelops storms overhead MKG/GRR in the 23z time frame.
Not being so sure that will really happen I have VCTS MKG by 21z
but if those storms hold together they would get there sooner than
that. The storms may have gusty winds as they roll through the
TAF sites.
Once the storms are through the area it should be breezy with vfr
cigs. Toward 09z-10z I expect rain showers to develop and impact
the MKG and GRR taf sites. These will spread inland and impact all
of the taf sites by 15z. Enough cold air moves in so that all taf
sites should see a change to snow by 15z expect MKG which is to
close to big lake with water temps in the mid 50s. At AZO I could
see snow showers being much heavier than I now have in the tafs.
That too will have to be watched. I will become very windy
tomorrow I could see winds in the afternoon being 30 kts gusting
to 45 kts at times.
The bottom line is VFR conditions early this afternoon my be
briefly MVFR with showers and thunderstorms later this afternoon
into this evening and solid IFR by mid morning Saturday.
&&
.MARINE...
Issued at 255 PM EST Fri Nov 18 2016
We will keep the headlines as is for the time being. Gales are a
solid bet, with storm force gusts not out of the question. Winds
that will be able to be tapped from above should stay just below
storm force. We may get a gust or two at storm force during the peak
winds Sat afternoon, but not enough to justify an upgrade at this
time.
&&
.HYDROLOGY...
Issued at 1003 AM EST Fri Nov 18 2016
River levels are returning closer to November normals following
two weeks of mostly dry weather. A quarter to half inch of total
precipitation is expected through Saturday, first from rain and
possibly a thunderstorm Friday evening, then from lake-enhanced
rain/snow on Saturday. Only minor rises in river levels would
result. The next opportunity for precipitation is Tuesday night
into Wednesday.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...Wind Advisory from 10 AM to 10 PM EST Saturday for MIZ037-043-
050-056-064-071.
LM...Gale Warning until 5 AM EST Sunday for LMZ844>849.
&&
$$
SYNOPSIS...NJJ
SHORT TERM...NJJ
LONG TERM...WDM
AVIATION...WDM
HYDROLOGY...CAS
MARINE...NJJ
AREA FORECAST DISCUSSION
National Weather Service New Orleans LA
351 PM CST Fri Nov 18 2016
.SHORT TERM...
The upper level ridge that was over the area is quickly
progressing east today while a trough is moving across the
central/high plains. A strong cold front on the leading edge of
the trough is currently moving across north Louisiana Friday and
should entering the northwestern CWA between sunset and 03z.
Shouldn`t take but about 6 hours for the front to move completely
across the forecast area. In terms of rain, radar trends over the
last few hours shows some filling in of the line as it moved from
TX into LA. The HRRR and even medium range models shows this
holding together through the northwestern third of the CWA before
breaking up and diminishing in coverage from there southeastward.
The latest forecast pops were adjusted to attempt to show this
with near 50% chance of rain NW of BTR down to 20-30% along the LA
coast.
.LONG TERM...
Post frontal air mass will be the coldest temperatures the region
has seen since last spring. Highs over the weekend will barely reach
into the lower 60s. Elevated winds behind the front will keep temps
from falling too much Saturday night, but still likely to see mid to
upper 30s in the northern half of the CWA (40-50 south). Monday
morning will be the coldest and dropped forecast lows a couple more
degrees from the previous forecast. MAV/MET guidance looks to better
capture the clear/calm conditions compared to blended models, so
thinking lows in the lower to mid 30s along and north of I-12 in LA
and I-10 in MS with a handful of locations dropping to freezing or
even just below 30. Widespread frost is expected in those areas.
Temperatures will then begin to moderate Monday and Tuesday as a
weak upper ridge slides across the northern Gulf Coast. Following
on its heels, a more southerly oriented trough will pass across the
Rockies Tuesday and shoot off to the northeast Wednesday. This will
bring another front to the forecast area but with the upper trough
moving away from the area then, the front will likely washout as it
gets here. Some rain expected but should be fairly weak convection
an decreasing in coverage as the boundary moves in.
Meffer
&&
.AVIATION...
mostly VFR conditions are expected through Saturday. The exception
will be as a convective band of isolated to scattered SHRA and a few
TSRA, associated with a strong cold front, move through southeast LA
and south MS from northwest to southeast between 03z and 11z
Saturday. Isolated SHRA could also develop late this afternoon and
early this evening in advance of the main band. Some lower MVFR
category conditions due to CIGS and/or VSBY may impact the
terminals, so have indicated VCSH or PROB30 -SHRA. Stronger and
gusty northwest to north winds will follow cold frontal passage late
tonight into Saturday. 22/TD
&&
.MARINE...
Strong cold front is expected to move through Lakes Maurepas and
Pontchartrain between 2 and 3 am tonight and the sounds and coastal
waters between 3 am and 9 am Saturday. Small Craft Advisory (SCA)
conditions with occasional gusts to near gale force are expected to
develop fairly quickly behind the front, so the timing of the start
of SCA headline has been set accordingly. SCA conditions are then to
continue through at least mid morning on Sunday as colder air and
high pressure build into the region. The exception is Lakes
Pontchartrain and Maurepas where there should be a drop below SCA
Saturday afternoon before winds and waves pick back up in the
evening and overnight hours Saturday night.
High pressure will build in closer to the coast Sunday afternoon,
then gradually move east Monday into Tuesday. Winds and seas are
expected to subside from late Sunday morning through Monday. Another
weaker cold front is expected to move through the marine area
Wednesday night shifting winds from southerly back to northerly
again, but staying below SCA criteria. 22/TD
&&
DECISION SUPPORT...
DSS code: Blue
Deployed: None.
Activation: None.
Activities: Drought Monitoring, Enhanced Fire Danger Risk Saturday,
and Small Craft Advisory late tonight through Sunday morning.
Decision Support Services (DSS) Code Legend
Green = No weather impacts that require action.
Blue = Long-fused watch, warning, or advisory in effect or
high visibility event.
Yellow = Heightened impacts with short-fused watch, warning or
advisory issuances; radar support.
Orange = High Impacts; Slight to Moderate risk severe; nearby
tropical events; HazMat or other large episodes.
Red = Full engagement for Moderate risk of severe and/or
direct tropical threats; Events of National Significance.
&&
.PRELIMINARY POINT TEMPS/POPS...
MCB 47 61 34 63 / 50 0 0 0
BTR 50 62 35 62 / 50 0 0 0
ASD 53 63 37 63 / 40 0 0 0
MSY 56 62 45 62 / 40 0 0 0
GPT 56 65 38 62 / 40 10 0 0
PQL 55 65 36 63 / 40 10 0 0
&&
.LIX WATCHES/WARNINGS/ADVISORIES...
LA...None.
GM...Small Craft Advisory from 6 AM Saturday to noon CST Sunday for
GMZ532-534-536-538-550-552-555-557-570-572-575-577.
Small Craft Advisory from 3 AM to noon CST Saturday for GMZ530.
MS...None.
GM...Small Craft Advisory from 6 AM Saturday to noon CST Sunday for
GMZ534-536-538-550-552-555-557-570-572-575-577.
&&
$$
Area Forecast Discussion
National Weather Service San Francisco Bay Area
258 PM PST Fri Nov 18 2016
...Widespread Rain Expected Over the Weekend...
.SYNOPSIS...Widespread rain is forecast to spread from north to
south across the district beginning tonight through Saturday.
Periods of rain will continue on Sunday. Dry weather will likely
return by Monday, but rain is possible once again by the middle of
next week.
&&
.DISCUSSION...As of 3:00 PM PST Friday...In general everything
appears to be coming together for a substantial change in the
weather this weekend as a Pacific Storm System continues to
approach the West Coast. Currently the center of circulation is
around 750 miles west of Seattle while a longwave trough stretches
southwestward. At the same time a substantial cold front ahead and
south of the low will advance to the coast later today with
associated rainfall forecast to move into the North Bay starting
this evening. KBHX radar nicely shows the leading edge of
precipitation which the HRRR appears to have initialized close to
reality.
Rainfall will move to the NW Sonoma coast close to 8 PM and then
down to San Francisco around 4 AM. Rain will continue to progress
to the south and be in the Monterey Bay Region just after sunrise.
Rain rates will pick up during the day as the cold front moves to
our CWA which could lead to moderate or even briefly heavy
rainfall at times. Behind the front rain is still expected to
continue through Sunday, although coverage and amounts will be
considerably less. Totals are only slightly different from
yesterday and the overnight shift with the greatest numbers still
forecast for the North Bay. Still looking at 2-4" for the North
Bay Mountains with 1-2" for the rest of the North Bay and the
Santa Cruz Mountains. Around SF Bay generally 2/3" to 1 1/3" can
be expected with lesser amounts to the south.
Winds will be the other story with gusty southerly winds forecast
just ahead of the front. Based off of latest guidance which now
has speeds near 50 KT just above the surface both along the coast
and some of the higher elevation spots, a wind advisory is now in
effect (please see SFONPWMTR for details). Even locations around
San Francisco Bay will see gusty conditions -- possibly to around
40 MPH on Saturday.
After a dry Monday and Tuesday the models indicate that two more
systems will move through the remainder of next week. Timing has
gotten a bit better with most of the solutions now brining rain
through on Wednesday and Friday. Neither of these systems appear
strong.
Both the 6 to 10 and 8 to 14 day outlooks continue to favor wetter
than normal conditions.
&&
.AVIATION...As of 9:52 AM PST Friday...For 18z tafs. Approaching
storm system will bring deteriorating ceilings, rain, and increasing
southerly winds through the TAF period. Cigs generally VFR today
then decreasing down to MVFR as front approaches.
Likewise, southerly wind gusts will strengthen as the front
approaches. Some favored areas could see gusts up to or exceeding 35
knots near the front. Rain will begin to move into the North Bay as
early as 04Z Sat before spreading southward through the night and
into Saturday.
Confidence high.
Vicinity of KSFO...VFR through today then becoming MVFR late tonight
into early tomorrow as front arrives. Southerly winds will gradually
increase through the TAF period with gusts up to 30 KT possible.
Visibility may briefly drop following the frontal passage and
heaviest rains. Rain expected to begin before sunrise.
SFO Bridge Approach...Similar to KSFO.
Monterey Bay Terminals...VFR. Mostly clear skies and light winds
today with ceilings beginning to deteriorate late tonight into
tomorrow morning. Rain tomorrow morning after sunrise.
&&
.MARINE...as of 02:21 PM PST Friday...Southerly winds will
increase significantly tonight and into tomorrow ahead of an
approaching storm system. gale force gusts and periodically
moderate to heavy rain are expected as the front moves into the
area. gusts will generally range from 35 to 45 kt with localized
bursts to 50 kt possible. winds will veer northerly behind the
front by sunday with a building nw swell.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.Tngt...Wind Advisory...Various locations including coastal
areas plus SF Bay Region and most higher
elevation spots.
SCA...Pigeon Pt to Pt Pinos 0-10 nm
GLW...Pigeon Pt to Pt Pinos 0-10 nm from 4 AM
GLW...Pt Pinos to Pt Piedras Blancas 0-10 nm from 4 AM
SCA...Pt Arena to Pigeon Pt 10-60 nm until 3 PM
GLW...Pt Arena to Pigeon Pt 10-60 nm
SCA...Mry Bay until 1 AM
SCA...Pt Reyes to Pigeon Pt 0-10 nm until 1 AM
SCA...Pigeon Pt to Pt Piedras Blancas 10-60 nm until 1 AM
GLW...Pt Reyes to Pigeon Pt 0-10 nm from 1 AM
GLW...Pigeon Pt to Pt Piedras Blancas 10-60 nm from 1 AM
SCA...Pt Arena to Pt Reyes 0-10 nm until 7 PM
GLW...Pt Arena to Pt Reyes 0-10 nm from 7 PM
SCA...Pt Pinos to Pt Piedras Blancas 0-10 nm
SCA...SF Bay from 1 AM
&&
$$
PUBLIC FORECAST: Bell
AVIATION: DRP
MARINE: DRP
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