Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 02/05/19
Area Forecast Discussion
National Weather Service Wichita KS
520 PM CST Mon Feb 4 2019
...Updated Aviation Discussion...
.SHORT TERM...(This evening through Thursday night)
Issued at 250 PM CST Mon Feb 4 2019
Old man winter made a rude return as a strong cold front plowed
through the region early this morning. Temperatures closer to
normal will be rule for the short term along with some patchy wintry
precipitation as well. By this evening the CAA will weaken some and
the mid level winds will turn to the south ahead of a short wave
trough progged to come through the region Tuesday night and into
Wednesday. However, the NAM and RAP are indicating some patchy
freezing drizzle during the morning hours Tuesday ahead of this.
shortwave. The GFS and the ECMWF are much drier and do not indicate
the precip. This makes for a challenging forecast for the short
term. Increased POPs for tonight to allow for some patchy freezing
drizzle tomorrow morning to compensate. This challenge will carry
through Tuesday night and into Wednesday morning as well. This same
set up looks to remain until the next short wave passes through the
region. Low level temperatures Tuesday to remain close to normal
which create the chance for some additional freezing drizzle Tuesday
night and Wednesday morning. Only areas of extreme Southeast Kansas
are likely to escape the freezing drizzle. Additionally, if the
ECMWF is correct as a whole, the extent of the freezing drizzle will
be reduced even further to the north.
By Wednesday afternoon and into the evening, the next short wave is
expected to have moved through the region. Very strong CAA will
return behind this front. Additionally, the pressure gradient is
expected to be very tight allowing for some gusty north winds
creating some dangerous wind chill conditions as well during the
afternoon and evening. Fortunately, nearly all the models agree
this system, while vigorous, will be too progressive and will pull
out of the region before any significant snow can occur. As such,
only expecting flurries at this time for Thursday and Thursday
night.
Metzger
.LONG TERM...(Friday through Monday)
Issued at 250 PM CST Mon Feb 4 2019
The extended range looks rather quiet but cold. Generally normal to
just below normal temperatures are expected into the weekend.
Temperatures are likely to warm up some Saturday night and into
Sunday as a new weather system approaches. This system`s approach
will allow southerly winds to return to the region and allow
temperatures to approach normal for Sunday. However, the ECMWF and
the GFS both indicate this system will be fast moving which will
temper the warm up as colder air is expected to return Sunday
evening and into Monday.
Metzger
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 513 PM CST Mon Feb 4 2019
Early this evening, VFR flight conditions are observed across
central, south central, and southeast Kansas. As previous
discussions mentioned, these conditions will be short lived with
overrunning of low level moisture this evening and overnight
tonight. This will introduce MVFR ceilings at most sites by the
early morning hours, though southeast Kansas may experience IFR
ceilings at KCNU for a period of time. It is not out of the
question that moisture within the column could become deep enough
to produce some patchy freezing drizzle across south central and
southeast Kansas briefly, but confidence in this remains low so
have left the mention out of the TAFs for now. Winds will be
fairly uniform throughout the period, generally from the the
northeast at roughly 10kts.
&&
.FIRE WEATHER...
Issued at 250 PM CST Mon Feb 4 2019
Fire weather conditions are expected to remain low for most of the
week due to persistent drizzle and colder temperatures. Thursday is
likely to have the highest Grassland Fire Danger indices due to the
brisk north winds but the fire danger is not expected to get above
"high" due to the ground being moist and the below normal
temperatures that will be expected for much of the week.
Metzger
&&
.PRELIMINARY POINT TEMPS/POPS...
Wichita-KICT 26 40 33 53 / 20 20 30 30
Hutchinson 24 37 28 48 / 20 10 20 20
Newton 24 37 29 47 / 20 20 30 30
ElDorado 26 39 32 52 / 20 30 30 30
Winfield-KWLD 28 44 37 59 / 20 30 30 40
Russell 19 32 23 39 / 10 10 10 20
Great Bend 20 35 25 45 / 10 10 10 20
Salina 21 33 24 42 / 10 10 10 20
McPherson 22 35 26 46 / 10 10 20 20
Coffeyville 31 46 40 62 / 20 50 50 60
Chanute 28 41 36 55 / 20 50 40 60
Iola 27 39 34 53 / 20 50 40 50
Parsons-KPPF 30 44 39 59 / 20 50 50 60
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SHORT TERM...ELM
LONG TERM...ELM
AVIATION...TAV
FIRE WEATHER...ELM
Area Forecast Discussion
National Weather Service Lincoln IL
907 PM CST Mon Feb 4 2019
.UPDATE...
Issued at 907 PM CST Mon Feb 4 2019
For the most part the current forecast is right on track with
clouds departing tonight behind the front that moved through the
area this afternoon. Temperatures will continue to fall through
the night and current forecast still looks good with this too.
Will have to make some cloud cover updates due to the clouds being
slower to move to the east. The clearing line has just now reach
Galesburg and previous models had clearing line already reaching
PIA before now. So update for slower cloud cover will be sent
shortly.
&&
.SHORT TERM...(This evening through Tuesday)
ISSUED AT 249 PM CST Mon Feb 4 2019
Fropa is pushing through central Illinois this afternoon. A weak
band of showers is associated with the leading edge of the frontal
boundary, currently along a Danville to Shelbyville line.
Immediately behind the front, colder air is filtering into the
region, and will continue to usher colder temps into central
Illinois overnight. Clouds will diminish overnight, to mostly
clear skies by 06z, based on NAM12 and RAP models. Tuesday will
start out dry, and linger clear skies through the morning, before
more clouds build into the area ahead of the next large weather
system.
.LONG TERM...(Tuesday night through Monday)
ISSUED AT 249 PM CST Mon Feb 4 2019
Starting Tuesday evening, numerous weather systems will progress
through the region during the week. The main focus with todays
forecast was Tuesday night through Thursday. Precipitation will
arrive Tuesday evening across portions of western Illinois,
bringing chances for rain and freezing rain. Using the GFS20,
ECMWF, and NAM12 upper air soundings, freezing rain is forecast to
initiate near 21z in GBG while holding off until 00z for PIA. This
system will move east north-east through the night, impacting
Bloomington and locations north by 03z. A winter weather advisory
has been issued for locations along a Rushville to Bloomington
line, as total ice accumulations are forecast in the one to two
tenths of an inch range Tuesday night through Wednesday morning.
South central and southern Illinois will see rainfall with this
system. Another system will quickly shift into the region
Wednesday afternoon, bringing more wet weather to the Midwest.
Temperatures during this system will remain above freezing,
allowing for rainfall to be the precipitation type. Finally, one
last round of rain and snow will move through Thursday morning
into the afternoon. Most of the main models have this final system
arriving as all rain, during the morning, then a rapid change to
light snow in the afternoon as fropa occurs. Behind this cold
front, another blast of colder Arctic air will move overhead to
end the week. Current storm total QPF values for the mid-week
events are in the half inch to two and a half inch range, from GBG
to LWV respectively. Further investigation over the next 24 hours
will occur, and if needed, flood products will be issued. Periods
after this were not analyzed in detail, due to more attention on
the short term.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 553 PM CST Mon Feb 4 2019
Cloud cover will continue across the area early this evening but
clearing will occur during the evening hours. Used satellite loop
to time the clearing line into the sites, though kept sky cover
tonight as scattered. All sites will become scattered, though
CMI/DEC/BMI will become scattered couple hours later than SPI and
PIA. Expecting cirrus later tonight and then broken cirrus toward
morning in advance of the next weather system. MVFR (IFR at BMI) clouds
around 1kft will then advect into all sites tomorrow morning with
the next weather system. Could have some precip at PIA and SPI
during the afternoon, but only chance pops so will hold off on
introducing precip in TAFs at this time. Winds will be northwest
this evening and then become northerly overnight, then
northeasterly tomorrow morning, followed by easterly tomorrow
afternoon. Wind speeds will be 10-15kts this evening but then
decrease for tonight and be less than 10kts tomorrow.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory from 3 PM Tuesday to 6 AM CST Wednesday
for ILZ027>029-036-037-040-041.
Winter Weather Advisory from 6 PM Tuesday to 6 AM CST Wednesday
for ILZ030-031-038.
&&
$$
UPDATE...Auten
SHORT TERM...Baker
LONG TERM...Baker
AVIATION...Auten
Area Forecast Discussion
National Weather Service Key West FL
930 PM EST Mon Feb 4 2019
.CURRENTLY...
Main item of interest today has been areas of low stratus and
even fog drifting around the Lower Keys and the Gulf waters. The
00z KEY sounding showed warming and drying on the sounding above a
very shallow 400-foot deep surface-based moist layer. Latest
GOES-16 fog imagery shows the area of low stratus shrinking
between Sand Key and the Dry Tortugas. Surface dewpoints are
currently 67F and 65F at Key West and Marathon, which is down 3
degrees at both sites since the same time last evening.
.DISCUSSION...
Current trend of shrinking stratus coverage and a 24-hour
decrease in dewpoint of 3 degrees suggests low stratus and fog
will be more sparse on Tue AM, compared with this morning. No fog
in the forecast over the islands.
A strong upper level high pressure ridge will expand from the
southwest Gulf across Central and South Florida Tue night and Wed.
It will settle south across the Keys from Friday through Sunday.
It will weaken and exit off to the east next Monday.
This pattern will really suppress shower activity until the upper
ridge starts to weaken and break down from Days 5 through 7. GFS
time height section over the next week shows substantial mid-level
drying occurring on Tuesday, with very dry mid-level air well
into Saturday.
Next Saturday, the Keys will come under the southern periphery of
a very strong surface high center passing across the Great Lakes.
This should bring breezy east winds. The surface-based moist layer
will deepen. GFS ensemble mean increases Precipitable Water
values quickly next Saturday, peaking near 1.3" on Sunday. The
strong easterly flow will support small-scale lines which could
finally focus and support a few passing showers over the island
chain from Saturday through Monday.
&&
.MARINE...
No visibility reduction is forecast over the Keys waters tonight
and Tue morning. It now looks like merely some low clouds that
should have little if any effect on surface visibility.
Through Tuesday evening, a surface high pressure center will drift
around north-central and northeast Florida and the waters off the
First and Space Coasts. Close proximity of a surface high center
will keep winds tame, with light and gentle N-NE breezes expected.
Late Tue night, the surface high will start to elongate off to the
northeast, with the eastern portion of the ridge axis settling
toward Bermuda on Thu. Net effect is that by Thu night, an
elongated surface ridge axis will stretch from northeast Florida
to Bermuda. Sensibly, easterly breezes will freshen on Tue night
and Wed, with moderate to fresh easterly breezes expected on Thu
and Fri. On Saturday, a very strong high pressure center will push
across the Great Lakes region, with strong pressure gradients on
its southern periphery pushing into the Keys. Further freshening
of east wind is expected Saturday, with strong wind expected.
Looks like rough waters next weekend. This is the first chance of
seeing Small Craft Advisory conditions in the forecast.
&&
.AVIATION...
LIFR cigs are the main forecast concern for the next 12-18 hours.
Current trend of shrinking stratus coverage and a 24-hour
decrease in dewpoint of 3 degrees suggests low stratus and fog
will be more sparse on Tue AM, compared with this morning.
Reduced visibility has been removed from the TAFs, but still
holding on to LIFR and IFR cigs at EYW late tonight and Tue
morning.
Latest GOES-16 fog imagery shows a band of low stratus from near
Sand Key out to the Dry Tortugas, drifting slowly to the south
away from the EYW terminal. Have amended the TAF to reflect
prevailing VFR for the rest of this evening. The 00z HRRR shows
about a 500-foot ceiling developing over parts of the Lower Keys
around 06z (1 am), with low cigs exiting the Lower Keys by 12z (7
am). The 18z NAM carries a near-saturated boundary layer until
about 18z Tue. So there is ultimately still some risk of LIFR cigs
of 005 or less on Tue AM. However if such conditions develop, it
should also be interspersed with holes and breaks until
dissipation later Tue morning.
MTH stands even less chance of LIFR conditions than EYW. No LIFR
cigs are forecast there, just some low SCT layers. Even that may
be overdone.
&&
.CLIMATE...
In 1951, the daily record cold high temperature of 59 degrees was
recorded in Key West. Temperature records date back to 1872.
&&
.KEY WATCHES/WARNINGS/ADVISORIES...
FL...None.
GM...None.
&&
$$
Public/Marine/Fire...Haner
Aviation/Nowcasts....Haner
Data Collection......SD
Visit us on the web at weather.gov/key
Follow us on Facebook and Twitter at:
www.facebook.com/nwskeywest
www.twitter.com/nwskeywest
Area Forecast Discussion
National Weather Service Melbourne FL
1030 PM EST Mon Feb 4 2019
.UPDATE...
High pressure will settle over north Florida tonight resulting in
very light to calm winds. There will be some cirrus streaming high
overhead but this will have little effect on temps. With high sfc
humidity, expect patchy to areas of fog to form, locally dense in
spots. Already seeing some stratus developing along the coast in St
Lucie county and some evidence on satellite data over Mosquito
Lagoon. HRRR guidance is focusing on north and east of Orlando for
best chance for reduced visibilities while LAMP guidance encompasses
more of metro Orlando and Lake county. The trend though is to reduce
the coverage of fog esp in the HRRR. Did not make any changes to min
temps which will be in the low to mid 50s most areas. On Tue, the
fog and stratus should erode more quickly than today resulting in a
very pleasant afternoon with light and variable winds and max temps
in the upper 70s interior and lower 70s along the Volusia/Brevard
coasts.
&&
.AVIATION...
Stratus has begun developing along the coast and will produce IFR
CIGs initially then settle toward the ground and produce IFR VSBYs.
Model guidance is hitting TIX-SFB-DAB the hardest with VSBY
reductions late tonight/early Tue but all terminals will have a
chance. Conditions should improve more quickly on Tue with VFR conds
returning to all terminals by 15Z.
&&
.MARINE...
Tonight-Tue...Light N/NW flow 10 knots or less tonight will veer NE
to E Tue along the coast. Seas 3 to 4 feet mainly in a E/NE swell.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 70 52 74 58 / 0 0 0 0
MCO 76 57 78 58 / 0 0 0 0
MLB 72 56 74 59 / 0 0 0 0
VRB 74 56 75 61 / 0 0 0 0
LEE 76 56 78 58 / 0 0 0 0
SFB 74 55 77 58 / 0 0 0 0
ORL 75 58 77 58 / 0 0 0 0
FPR 74 56 76 61 / 0 0 0 0
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...None.
AM...None.
&&
$$
Kelly/Bragaw
Area Forecast Discussion
National Weather Service New York NY
954 PM EST Mon Feb 4 2019
.SYNOPSIS...
Weak high pressure gives way to frontal system approaching from
the Great Lakes and Ohio Valley states tonight. The front
crosses the area late Tuesday afternoon into early evening. High
pressure briefly follows for Wednesday before a series of
frontal waves impact the area Wednesday night through Friday.
High pressure returns for the weekend.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
Low pressure continues to retreat off the Mid Atlantic coast
tonight, while a cold front approaches from the Great Lakes and
Ohio Valley states. Weak high pressure will also gradually lose
it footing across the area with light and variable winds through
the night.
Starting to see signs of stratus development on the south shore
of Suffolk County, although fog extent remains patchy. Forecast
remains on track, with hourly temps and dews remaining
challenging this eve. As the stratus expands these should level
off, although it will be a few hours before a decent extent
develops, at least along the coast. Still unsure how far west
and inland this will get, although NAM and to a degree the RAP
and HRRR are still showing a very shallow layer of moisture near
the sfc, even into NYC. GFS is likely too dry in the boundary
layer, however, even last night the fog was only confined to far
eastern Long Island and southeast Connecticut. 00Z OKX sounding
shows a strong and very shallow low-level inversion. NAM has
been showing this for the last couple of days. This profile
allows for good radiational cooling at the top of the boundary
layer and thus a preference for cooler air to mix down to the
surface. Still though, confidence on the coverage is not high.
That being the case, this is third night of a weak return flow
and dew points in the 30s. Thus, leaning toward widespread fog
encompassing much of the area late tonight, some of which may
become dense.
As for the aforementioned cold front, as it approaches weak warm
advection may trip off a shower well north and west of NYC.
Best thermal forcing and dynamics resides well north and west of
the area. Thermal profiles only support rain.
Lows are forecast to be in the upper 30s to lower 40s, about 10
to 15 degrees above normal.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/...
Areas of morning fog will gradually dissipate from west to east
as a W-SW flow develops out ahead of the approaching cold
front. There is the potential for lows clouds and fog to linger
across eastern Long Island and southeast Connecticut into early
afternoon. Cold front moves through dry during the late
afternoon and early evening hours with clearing skies. While not
record warm, highs in the warm sector will rise well into the
50s, possibly the lower 60s. Along the immediate coast,
especially eastern coastal locations, temperatures struggle to
get out of the upper 40s. The latter of which will depend on the
duration of fog/low clouds.
Weak cold advection and northerly winds will return temperatures
closer to normal for lows Tuesday night, but still a few
degrees above normal.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
High pressure keeps us dry through at least Wednesday morning. A
wave of low pressure then forms along a warm front across the Mid-
Atlantic before passing to our south Wednesday night into Thursday
morning. This will bring primarily rain across the area, with most
of it falling during Wednesday night, but chances begin Wednesday
afternoon and linger into Thursday. Surface temperatures across some
of the northernmost suburbs however may still be at freezing or
below for a period as the low to our south helps back winds into a
more northerly direction. With plenty of warm air aloft to preclude
snow and sleet, these spots could pick up light ice accumulations.
Will hold off on any advisory issuance with this being a 5th period
event and not enough confidence in adequate coverage.
The warm front remains to our south throughout Thursday with low
level moisture still lingering over the forecast area, so still a
chances of light rain or drizzle. Low pressure then moves through
the Great Lakes Region Thursday night and then through Southeast
Canada Friday. This low appears to be strong enough, along with help
of a developing low level jet, to push the warm front north through
the forecast area late Thursday night into Friday morning before a
trailing cold front moves through later in the day Friday. Will
maintain at least a chance of light rain and drizzle before rain
becomes likely once again with the cold front passage. Temperatures
Thursday and Friday will be above normal.
High pressure will then return with dry weather and below-normal
temperatures through the weekend. Weak low pressure then brings a
chance of snow or potentially mixed precipitation Sunday night into
Monday.
&&
.AVIATION /03Z TUESDAY THROUGH SATURDAY/...
High pressure shifts farther offshore tonight. A cold front
passes Tue aftn.
Conditions will continue to lower to MVFR and IFR as fog
develops thru 06Z. The fog is expected to be more widespread
than previous nights and some areas may even lower to LIFR late
tonight. Conditions are expected to slowly improve back to VFR
between 12z-15z Tuesday morning. A few patches of mvfr cigs are
possible behind the front on Tue.
Winds are expected to be light and variable to calm tonight.
Wind speeds will remain less than 10 kt. Winds become nwly
behind the front on Tue.
.OUTLOOK FOR 00Z WEDNESDAY THROUGH SATURDAY...
.Tuesday Night...VFR with NW flow.
.Wednesday...VFR.
.Wednesday night-Friday...MVFR to IFR with rain. There is a
slight chance of some freezing rain and sleet across the Lower
Hudson Valley into interior southern Connecticut late Wednesday
night into early Thursday morning.
.Saturday...Mainly VFR.
&&
.MARINE...
Stratus development has begun over land in Suffolk County and is
expected to continue to expand through the remainder of the
evening and overnight. Will reissue the MWS for LI Sound and
surrounding bays as well as the waters east of Fire Island
Inlet for the time being. Remaining waters may be added later
tonight as conditions appear favorable for expansion.
Additionally, a dense fog advisory may even be needed for at
least part of the coastal waters.
Otherwise, a southerly swell from low pressure east of the Mid
Atlantic states will bring seas to around 5 ft on the ocean
waters Tuesday afternoon. Since seas are marginal and of long
period, plan to hold off on issuing a SCA at this time.
Sub-SCA conditions last through Wednesday with a weak pressure
gradient over the waters. A swell may build on Thursday with weak
low pressure in the vicinity, so ocean seas could build to 5 ft. A
better chance for all waters to have at least SCA conds will be
Friday into Saturday with the approach and passage of a cold front.
Gusts behind the cold front may even reach gale force for some of
the waters Friday night into Saturday morning.
&&
.HYDROLOGY...
A half inch to an inch of rainfall is anticipated from late-day
Wednesday through Thursday. Given the relatively wet antecedent
conditions, there is the possibility of at least the ponding of
water in urban/known poor drainage areas and a low risk of minor
flooding.
Additional light rainfall is expected Friday with dry weather this
weekend.
&&
.EQUIPMENT...
NYC Central Park winds are out of service until further notice.
Loss of data is due to a severed cable. Parts are on order.
NYC NOAA Weather Radio Station KWO35 (162.55 MHz) will remain off
the air for an extended period of time.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...None.
&&
$$
SYNOPSIS...JC/DW
NEAR TERM...24/DW
SHORT TERM...DW
LONG TERM...JC
AVIATION...BC/JMC
MARINE...JC/DW
HYDROLOGY...JC/DW
EQUIPMENT...
Area Forecast Discussion
National Weather Service Reno NV
327 PM PST Mon Feb 4 2019
.SYNOPSIS...
Periods of snow and gusty winds will continue impacting the area
through Tuesday morning, with blizzard conditions in the mountains.
Cold temperatures and mainly dry weather will settle in for the
balance of the week. Another storm is possible this coming weekend;
however, predictability in intensity and impacts is low.
&&
.SHORT TERM...
Ongoing Storm through Tuesday Afternoon
* Waves of snow showers continue across the region within colder,
more unstable airmass. The key is convection developing over CA
central valley which then pivots E/NE into our region as heavy
snow, spilling into the valleys of W Nevada at times. We expect
this on/off snow to continue through tonight and into Tuesday
morning per the latest HRRR and NAM 3km guidance. Forecast
message of blizzard conditions and travel being unwise in the
mountains remains in effect.
* For valleys things are more complicated. Of course. We do expect
spillover snow showers, heavy at times, into W Nevada this
afternoon with 1-2 more waves tonight. With cooler temps after
sunset we should start seeing road impacts in the cities
regardless of how much snow totals end up being. Tuesday morning
commute will be slow going, and the commute this evening could
even be problematic.
* For areas above 5000 feet plus Virginia City, Carson City,
Minden areas - snow impacts are much more likely with heavier
spillover and potential lake effect seen in HRRR. Winter storm
warnings overall look good from an impact standpoint. Should a
band of snow settle over one particular spot, not too
predictable and low probability, but that could easily produce
6-12" in short order given higher snow ratios - that can`t be
entirely ruled out from Reno to Minden.
* Gusty winds will also continue region-wide associated with
pronounced thermal gradient. One area we`re watching closely is
Hwy 95 near Hawthorne and Walker Lake where gusts could reach
50+ mph based on latest obs and HRRR wind trends.
* Snow showers becoming more widely scattered and disheveled
Tuesday afternoon. More instability driven. While guidance
doesn`t show it, lake effect could continue E/SE of Tahoe and
maybe even Pyramid.
-Chris
.LONG TERM...Tuesday night through Monday...
For Tuesday night through Thursday, dry and cold conditions will
prevail with decreasing clouds Wednesday followed by increasing
clouds (mainly mid and high) again Thursday. Highs Wednesday and
Thursday are expected to be mainly in the 30s, although any lower
elevation valleys which still have more than ~2 inches of snow on
the ground will likely be stuck in the 20s as ground heating is
blocked by snow cover. Note that this is not advertised in the
forecast as uncertainty remains on where residual snow cover will be
in far western Nevada and northeast CA (take a look out your door
Wednesday afternoon!).
Wednesday night looks to be the coldest night of the week due to the
combination of limited cloud cover and light winds. As snow cover
would affect highs, lows Wednesday night could also be affected by
snow cover. Even without snow cover, lows are expected to fall into
the high single digits to mid teens in the lower valleys, with any
snow-covered lower valleys likely to fall closer to 0 (again, not in
the forecast). For the Sierra valleys, lows Wednesday night are
expected to be generally between 5 below zero and 5 above (warmer
right at the shores of Lake Tahoe), with as low as -15 in the very
coldest valleys (such as Bodie). Clouds are expected to increase
after Wednesday night so lows should modify substantially for later
in the week.
Friday into early next week, another round of cold disturbances are
expected to affect the region. The first wave still looks more like
a glancing blow affecting mainly the Sierra, with the second round
centered around Sunday having a better shot at affecting both the
Sierra and western Nevada with snowfall. However, it could take
several days to hone in on details as where exactly the lower level
boundary/cold front sets up will greatly affect the intensity and
impacts of snowfall. This is especially true east of the Sierra
where events can live and die on where the smaller-scale frontal
boundaries set up (very uncertain right now). In addition, the time
of day is becoming more important this time of year as the sun`s
intensity increases and becomes more efficient at melting snow.
-Snyder/MJD
&&
.AVIATION...
For the Sierra through tonight, widespread IFR/LIFR conditions with
prevailing sub-landing mins conditions expected to continue as
moist, upslope flow persists ahead of low pressure dropping south
into northern California. Terminals in the Sierra (KTRK/KTVL/KMMH)
likely to see another 5 to 10 inches of snowfall.
For western and west-central NV, the system looks to under-perform
for many spots through tonight with perhaps up to an inch or two
of snowfall on untreated surfaces after dark. However, there is a
medium probability for more substantial snowfall (2-5 inches)
near and south of Highway 50 in far western NV (including KCXP/KMEV)
and for the higher elevations of west-central NV (west of KHTH,
south of Yerington). This is due to recent high-resolution
simulations and the possibility for snow enhancement off of Lake
Tahoe late tonight. Again, the confidence is only medium due to
uncertainty as to where the heavier snow shower bands set up.
After some residual snow showers Tuesday with light but sporadic
accumulations possible, the region dries out through Thursday.
Additional cold storms (mainly snow) are expected late week and
into next weekend. -Snyder
&&
.REV Watches/Warnings/Advisories...
NV...Winter Storm Warning until 7 AM PST Tuesday NVZ005.
Blizzard Warning until 10 PM PST this evening NVZ002.
Winter Storm Warning until 4 PM PST Tuesday NVZ002.
Winter Weather Advisory until 4 PM PST Tuesday NVZ001.
Winter Storm Warning until 10 AM PST Tuesday NVZ003.
Winter Weather Advisory until 10 AM PST Tuesday NVZ004.
CA...Winter Storm Warning until 4 PM PST Tuesday CAZ071.
Winter Storm Warning until 7 AM PST Tuesday CAZ070.
Winter Storm Warning until 4 PM PST Tuesday CAZ073.
Blizzard Warning until 10 PM PST this evening CAZ072-073.
Winter Storm Warning until 4 PM PST Tuesday CAZ072.
&&
$$
For more information from the National Weather Service visit...
http://weather.gov/reno
Area Forecast Discussion
National Weather Service Las Vegas NV
304 PM PST Mon Feb 4 2019
.SYNOPSIS...Active weather pattern continues as multiple rounds
of mountain snow and valley rain showers remain in the forecast
through at Wednesday morning. Snow levels will be dropping
as a cold front moves through, and significant snow accumulations
are possible again in the higher terrain of Southern Nevada, the
Sierra, and northern Mohave County.
&&
.SHORT TERM...Tonight through Wednesday.
We`re seeing precip coverage and intensity increasing on schedule
this afternoon across the Las Vegas Valley. While this second area
of moisture comes across and phases with impressive upper level
dynamics, we should see the heaviest precip between now and 10PM
tonight per the HRRR and other hi-res solutions, however some
enhancement may develop across northern Mohave County and southern
Utah per these same models. Latest IR satellite shows this area of
enhanced cloud development which is also beginning to be reflected
on radar across the Colorado River Valley. Latest QPF guidance
shows high elevations of Mohave could see 6-10 inches above 5000
inches with the multiple rounds of banded precip that could occur
over the next 24 hours, thus a Winter Weather Advisory was issued
for this part of the county beginning tonight at 06Z.
Otherwise, the forecast has not changed substantially other than
to decrease PoP potential from west to east a little earlier now
with a more progressive cold front passage depicted as well as
less moisture availability on the back end of the low pushing
east. That being said, model QPF values have increased with the
12Z runs for Mohave county after 00Z Wednesday so followed suit in
the grids.
For the prospect of valley snow Tuesday night into Wednesday
morning...snow levels still look to be plenty low enough to
warrant precip to reach the valley floor late Tuesday, but the
confidence in precip lingering after 00Z Wednesday tomorrow night
looks less and less likely. Latest forecast soundings in the
valley show a moist low level layer, enough to precipitate, for a
brief window of opportunity tomorrow afternoon and evening, but
drying out quickly after 00Z. Thus, it looks like perhaps if
snowflakes make it to the valley floor, it may be tomorrow
afternoon and evening.
By Wednesday morning, precip should be exiting east finally other
than possibly some lingering precip on the back end of the low in
Lincoln County. Other than that, dry and cold conditions will
prevail into the long term.
.LONG TERM...Thursday through Monday.
The long term begins quiet and cold - with some of the coldest
days/mornings so far this year. Widespread lows at or below freezing
for most of the region, excluding the Colorado River Valley.
The pattern resumes it`s active nature for the weekend. Currently
tracking a pair of systems that look to impact the region into next
week. The first system will be digging down from the gulf of Alaska
in the Pacific on Friday, swinging across the region Friday night
through Saturday. With moisture being shunted quite far south in the
middle of this week, this first weekend system looks to be mainly a
rain event, with precipitation confined to the Sierra Nevada and
Great Basin. The second system arrives Sunday, and should have more
of an opportunity to wrap more moisture back into the area with any
subsequent system having better precipitation chances. Details and
timing are far from certain, so confidence remains low.
Long term models in good agreement with keeping and active pattern
with Alaska ridge and west coast troughing for the next several
weeks, so warm, calm, dry weather will likely only be brief until
the pattern shifts again.
&&
.AVIATION...For McCarran...Stubborn southeast winds should find
their way to the southwest as a potentially more organized band of
showers moves through. CIGs could dip below 5 Kft in some showers
before low-level drying overnight along with stronger winds should
help to raise CIGs to 8 Kft or above. Cold air mass for tomorrow
with lingering moisture will likely lead to a number of clouds with
a few showers around as well. They should remain fairly light, with
timing and location nearly impossible to pin down. Clouds will
continue to carry supercooled water, so expect icing to remain a
threat along with turbulence through the period.
For the rest of southern Nevada, northwest Arizona and southeast
California...Lingering showers and ceilings between 5 Kft and 10 Kft
continuing tonight, with southwest winds kicking back up by Tuesday
afternoon. A cooler airmass with lingering moisture will help
reinforce a cloud deck between 5 Kft and 10 Kft once again tomorrow,
with a stray airmass shower or two possible. Turbulence and icing
remain threats through the TAF period for all sites.
&&
.SPOTTER INFORMATION STATEMENT...Spotters are encouraged to report
any significant weather or impacts according to standard operating
procedures.
&&
$$
SYNOPSIS/SHORT TERM...TB3
LONG TERM/AVIATION....Steele
For more forecast information...see us on our webpage:
http://weather.gov/lasvegas or follow us on Facebook and Twitter