Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 10/23/16
Area Forecast Discussion
National Weather Service Albany NY
1048 PM EDT Sat Oct 22 2016
.SYNOPSIS...
Chilly and blustery conditions the rest of weekend as a large
slow moving storm continues to impact the region. The storm will
move gradually northward across eastern Canada. Precipitation will
gradually wind down tonight.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
A Winter Weather Advisory for snow has been issued for southern
Vermont, Berkshire County and eastern Rensselaer County for
elevations above 1500 feet.
Spotters in southern Vermont reported 2 inches of snow had fallen
earlier this evening. In addition mobile spotters reported
accumulating snow on Route 9 in southern Vermont and on the Mass
Pike in Berkshire County. Spotter reports and ALY evening sounding
show snow level about 1500 feet or so. Thus Advisory is in effect
for elevations above 1500 feet. The HRRR indicates that upslope
flow into the Taconics, Berkshires, and Green`s will continue into
the early morning hours. The HRRR is quite bullish with QPF within
this regime. Not quite buying the amounts produced by the HRRR,
but still looks reasonable for 3-6 inches of snow to accumulate in
the Advisory area through the night. The snow will be of the
wetter variety.
Wind Advisory is in effect for all but the mid Hudson Valley
through 6pm Sunday. PSF reported a wind gust to 43 mph at 915 pm.
The deepening storm is resulting in a tightening pressure gradient
across the region. West to northwest winds will increase with
stronger gusts developing tonight.
As the upper low moves to our north precipitation will gradually
wind down tonight lingering longest across the higher terrain in
cyclonic flow.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY NIGHT/...
Wind Advisory remains in effect for Sunday.
Even though the strongest winds will have move across the area
Saturday night into early Sunday morning good mixing will result
in the continued threat for wind advisory criteria gusts much of
the day Sunday.
The system will begin to fill and weaken on Sunday as it
continues to head northward. Expecting some sunshine as cloud
cover decreases especially east of the Hudson River Valley.
Looking at dry weather for most of the day. Temperatures will be
seasonable mainly ranging from the mid 40s to upper 50s. However
the blustery winds will make it feel colder.
Clouds will be on the increase Sunday night as a short originating from
the Pacific Northwest over tops the ridge to the west and
reinforces the trough over the eastern United States. The short
wave is expected to pass over the Ohio Valley and mid-Atlantic
region bringing chances for some light rain to area mainly south
of I-90. With its passage will have cyclonic flow across the
region with additional short waves moving through the flow. Slight
below normal temperatures Monday with highs from the upper 30s to
mid 50s.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
High pressure will build into the region Tuesday and Wednesday.
This will bring dry but chilly weather to our region. High
temperatures on Tuesday will be in the 40-50 degree range across
the valley regions and upper 30s to lower 40s across the higher
terrain. Lows will be in the upper 20s to lower 30s.
By late Thursday and Friday an area of low pressure system with
associated front will move through the region. This will bring
the next threat of rain showers across the region. Will include a
chance of rain showers Thursday and Friday. Highs on Thursday will
continue to be a few degrees below normal in the 40s to around 50.
With mostly cloudy skies Thursday night...Lows Thursday night into
friday will be in the upper 30s to around 40.
Saturday and Sunday...Will keep a chance of showers across the
northern portion of the region with the low pressure system
departing into the Maine coast. Any showers that occur Saturday
AM should be light and diminish by the afternoon. High temperatures
on Saturday will be a few degrees above normal in the upper 50s to
around 60. Lows will be in the upper 30s across the higher terrain
to mid 40s across the valley locations
&&
.AVIATION /03Z SUNDAY THROUGH THURSDAY/...
Updated TAF for KGFL. Expected winds to pick up there tonight.
This has not happened. 10pm ob shows wind 4 knots at GFL. I have
updated the TAF to reflect lower wind speeds. This requires the
addition of LLWS to the TAF. 00Z ALY sounding showed winds of
30532KT at 1000 ft and 30543KT at 2000 ft.
An upper level low responsible for our precipitation this
afternoon/evening is pulling slowly northeast of terminal sites.
As it does, the deformation induced precipitation is slowly
winding down. This should lead to generally improving conditions
for most terminals. Only exception will be KPSF where moist,
upslope flow should keep precipitation going to 06Z or so. PSF saw
some IFR SN earlier today, but for the last several hours only RA
occurring. Not out of the question that some SN or RASN could
still occur at PSF through the night. So have included a TEMPO IFR
group there for vsby and cigs. Otherwise, expect ALB and GFL to be
MVFR then transition to VFR overnight. With bulk of the
precipitation to the north of KPOU, expect this site to be VFR
through the forecast.
Other issue will be winds. Winds will be gusty tonight, and
through Sunday. Gusts likely will exceed 30 knots Sunday at
favored channeling sites of KALB and KPSF.
Outlook...
Sunday Night: Low Operational Impact. Slight Chance of SHRA.
Monday: Low Operational Impact. Breezy NO SIG WX.
Monday Night: No Operational Impact. NO SIG WX.
Tuesday: No Operational Impact. NO SIG WX.
Tuesday Night: No Operational Impact. NO SIG WX.
Wednesday: No Operational Impact. NO SIG WX.
Wednesday Night: No Operational Impact. NO SIG WX.
Thursday: Moderate Operational Impact. Chance of SHRA.
&&
.FIRE WEATHER...
West to northwest winds will gust up to around 50 mph tonight and
Sunday.
Chilly and blustery conditions the rest of weekend as a large
slow moving storm continues to impact the region. This storm has
brought a widespread soaking rainfall to the area and it will move
gradually northward across eastern Canada. Precipitation will
gradually wind down tonight.
&&
.HYDROLOGY...
Chilly and blustery conditions the rest of weekend as a large
slow moving storm continues to impact the region. This storm has
brought a widespread soaking rainfall to the area and it will move
gradually northward across eastern Canada. Precipitation will
gradually wind down tonight.
Dry weather returns Sunday and only some light rainfall is expected
Sunday night into early Monday morning as a short wave passes by.
Then mainly fair weather is then expected through mid week with
unsettled weather returning later in the week.
For details on specific area rivers and lakes, including observed
and forecast river stages and lake elevations, please visit the
Advanced Hydrologic Prediction Service /AHPS/ graphs on our website.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...Wind Advisory until 6 PM EDT Sunday for CTZ001-013.
NY...Wind Advisory until 6 PM EDT Sunday for NYZ032-033-038>043-
047>054-058-061-063-066-082>084.
Winter Weather Advisory until 8 AM EDT Sunday for NYZ054.
MA...Wind Advisory until 6 PM EDT Sunday for MAZ001-025.
Winter Weather Advisory until 8 AM EDT Sunday for MAZ001-025.
VT...Wind Advisory until 6 PM EDT Sunday for VTZ013-014.
Winter Weather Advisory until 8 AM EDT Sunday for VTZ013-014.
&&
$$
SYNOPSIS...IAA
NEAR TERM...IAA/OKeefe
SHORT TERM...IAA
LONG TERM...VTK
AVIATION...VTK/OKeefe
FIRE WEATHER...IAA
HYDROLOGY...IAA
Area Forecast Discussion
National Weather Service Bismarck ND
932 PM CDT Sat Oct 22 2016
.UPDATE...
Issued at 924 PM CDT Sat Oct 22 2016
No changes for tonight other than to blend to observed trends
through 02 UTC. Little to no precipitation across north central
North Dakota is reaching the ground with dry air below 700 mb.
UPDATE Issued at 640 PM CDT Sat Oct 22 2016
Added fog to northwest North Dakota for late tonight into early
Saturday morning with this update. As low pressure across western
North Dakota into central South Dakota this evening propagates
east through the night, low level moisture in southern Canada will
wrap around behind the low, with stratus spreading across much of
the area late tonight into Saturday morning. The best chances for
fog are favored across northwest North Dakota per the 20-22 UTC
HRRR/RAP/GLAMPMELD iterations. This is in with observed trends
across Canada.
&&
.SHORT TERM...(This evening through Sunday)
Issued at 315 PM CDT Sat Oct 22 2016
A low pressure system continues to push west to east across the
northern plains. Short range models have handled the precipitation
well. Rain for the most part has stayed in the northern tier
counties of North Dakota. Chances for rain will diminish as the
system pushes further east tonight.
The previous few HRRR runs have shown the potential for some fog
to develop overnight in the northwest. However with minimal low
level moisture and the potential for cloud cover in the area have
held off on the mention of fog at this time.
.LONG TERM...(Sunday night through Saturday)
Issued at 315 PM CDT Sat Oct 22 2016
Dry and mild as upper level ridging develops over the area late
Sunday. With the peak of the ridge in place over the northern
plains Monday, southerly flow will be breezy with gusts near 25
mph across central and western North Dakota.
A short wave and low pressure system looks to develop on Tuesday
over the central plains with some wrap around rain entering
eastern North Dakota Tuesday into early Wednesday. As of now the
ECMWF is slower and favors a more northern track of the central
plains low and is wetter than the GFS solution. Upper level
ridging again builds over the region behind these two waves,
bringing mild and mainly dry conditions through the remainder of
the work week.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 924 PM CDT Sat Oct 22 2016
Low pressure across central North and South Dakota as of 02 UTC
will move east through tonight. MVFR stratus across southern
Canada is expected to build across western and central North
Dakota tonight into Saturday morning. IFR fog is possible at KISN.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AYD
SHORT TERM...MM
LONG TERM...MM
AVIATION...AYD
Area Forecast Discussion
National Weather Service Caribou ME
1030 PM EDT Sat Oct 22 2016
.SYNOPSIS...
Low pressure will lift north of the area overnight. The low will
remain to our north Sunday into Monday as cold gusty winds circulate
into our region behind the low.
&&
.NEAR TERM /THROUGH SUNDAY/...
1030 pm update...
Lopres down to 982 mb and is located in the vicinity of the North
Woods. Strongest pressure falls located just to the north of the
Gulf of St. Lawrence and expect low to continue to track nwd. H5
system rotating up thru NH at this time. Most of the steadier rain
has come to an end acrs CWA with just scattered showers streaming
north.
Winds are kicking up as low conts to deepen with srn locations
gusting upwards of 30kts. Expect these wind gusts wl continue to
spread north as lopres mvs into Quebec, thus no chgs needed to
wind speeds for the ovrngt.
Hv adjusted temps for most of the ovrngt as temps to the east of
the sfc low wl rise for next svrl hrs before they start dropping.
Hv bumped mins up accordingly by 3-6 degrees for tonight as cldr
air does not get advected much into CWA until after 08z mainly
acrs the nw. Also rmvd tstms for ovrngt with just showers expected
thru the course of the night.
Prev discussion blo...
Strong wind gusts and much colder.
The latest sfc analysis showed low pres lifting n across the
coast w/an area of rain moving into the downeast area. Satl WV
imagery showed area of enhancement pulling through Nova Scotia and
another smaller area associated w/a vorticity max off the southern
New England coast. This vorticity max will lift across the region
this evening into tonight w/an area of stronger winds as picked up
by the mesoscale guidance including the NAM12, HRRR and RAP.
Bufkit showed gust potential UP TO 40+ MPH across mainly across
the downeast and eastern side of the CWA early tonight w/the
disturbance. Sounding profiles also hinted at convective potential
w/elevated CAPE of 200-400 joules and swi down below 0. PWATS of
1.30" this evening coupled w/0-6km shear will aid to the
potential. Best window for any convection will be this evening and
as it looks right now across the central and easter portions of
the CWA. One thing to note is that the trend for convection was
down from the 06 & 12z runs. Decided to keep the mention of tstms
in there this evening and will issue a Special Weather Statement
to address the winds and heavy rainfall. Temps will start out warm
but drop back by early Sunday morning.
Winds are forecast to crank back up Sunday morning and continue
into early Sunday evening as low pres intensifies as it moves into
Quebec. CAA on the way w/momentum transfer showing gust potential
to 50 mph especially across the higher terrain terrain and open
areas. The only thing holding back full gust potential is the
cloud expected for Sunday. Any substantial breaks in the clouds
would allow for winds allow to mix down. 12Z run of the guidance
was a bit weaker than the previous guidance in regards to the wind
field. After coordination w/GYX, decided to hold off on any wind
headline. Later shifts can assess this situation further. Will
beef up wording in the Hazardous Weather Outlook. Rain showers
will move back across the area on Sunday. Temps will be dropping
back into the mid and upper 30s n and west where some snow could
mix in w/the rain showers. Further e and s, early high temps of
low to mid 40s w/temps dropping off by the afternoon.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
A large area of low pressure will be located in eastern Quebec
Sunday night as strong winds continue to wrap around the low
pulling cold air across the area. The cold advection will continue
to result in deep mixing making for gusty winds. Skies will remain
mostly cloudy across the far north with partial clearing likely
Downeast as some drier air circulates in beneath the low. The
storm will remain in Eastern Quebec on Monday as some moisture
pivoting around the upper trough begins to back south into our
area. This will bring some rain and snow showers to northern areas
while Downeast remains partly cloudy. Moisture will continue
circulating back into the region, mainly across the north, Monday
night as boundary layer temperatures become cold enough for snow
across much of the region. Some light accumulation of wet snow is
possible, especially over the higher elevations to the west. Snow
and rain showers will continue into Tuesday across the north and
west while Downeast becomes mostly cloudy as the surface low
weakens and backs down to the south a bit.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
Moisture pooled in the upper trough will bring a mostly cloudy
and chilly day on Wednesday as low pressure both surface and aloft
weakens and moves off to the east. Upper level ridging and
Canadian high pressure will build across the region on Thursday
bringing a return of sunshine and tranquil weather. However, the
dry weather may be brief as another shortwave trough approaches
Thursday night into Friday with a chance of rain.
&&
.AVIATION /02Z SUNDAY THROUGH THURSDAY/...
NEAR TERM: IFR expected at all terminals this evening. Expect
restrictions to rise to MVFR at BGR and BHB after 09z then
progressing north during the afternoon hours. Big story will be
the winds with gusts to between 30-35kts in the afternoon from the
SW. A very brief period of LLWS also expected for a time tonight.
SHORT TERM: Strong gusty west southwesterly winds will affect all
sites Sunday night into Monday. Some stratocumulus will limit
conditions to MVFR over the north Sunday night and Monday with VFR
conditions expected Downeast. MVFR to IFR conditions are expected
north Monday night and Tuesday in continued low clouds with VFR to
MVFR conditions Downeast. MVFR conditions downeast and MVFR to IFR
conditions in low clouds over the north can be expected Tuesday
night into Wednesday. Conditions should return to VFR across the
area later Wednesday night into Thursday.
&&
.MARINE...
NEAR TERM: Decided to put the intra coastal area in a Gale Warning
as gusts to 35 kts are expected tonight and another round expected
for Sunday. Increased sustained winds on Sunday to 30 kts w/gusts
closing in on 40 kts especially over the outer zones. Southerly
swell out there attm w/11 period seconds and heights of 6-7 ft.
Expected seas to build later tonight and especially on Sunday
w/the increasing winds. Since, wind field will be offshore, not
expected any coastal flood or erosion problems.
SHORT TERM: A gale warning will likely be needed Sunday night
into Monday. Winds may diminish to SCA over the intracoastal
waters later Monday. An SCA will likely be needed Tuesday. Winds
will gradually diminish Tuesday night into Wednesday night then be
light on Thursday as high pressure builds over.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...None.
MARINE...Gale Warning until 8 PM EDT Sunday for ANZ052.
Gale Warning until midnight EDT Sunday night for ANZ050-051.
&&
$$
Near Term...Farrar/Hewitt
Short Term...Bloomer
Long Term...Bloomer
Aviation...Farrar/Hewitt/Bloomer
Marine...Farrar/Hewitt/Bloomer
AREA FORECAST DISCUSSION...UPDATED
National Weather Service Jackson KY
1051 PM EDT Sat Oct 22 2016
.UPDATE...
Issued at 1050 PM EDT SAT OCT 22 2016
Hourly temperatures have been freshened up based on trends in
observations. High pressure will bring mostly clear skies and
light winds overnight. Lows in the valleys should reach the mid to
upper 30s range with patchy frost especially in the normally
colder locations. Frost wording has been adjusted in the HWO for
patchy frost in more of the valleys.
UPDATE Issued at 755 PM EDT SAT OCT 22 2016
Temperatures in some of the deeper eastern valley locations have
already dropped into the low to mid 40s with winds having
slackened or decoupled there. This combined with afternoon
crossover temperatures in the mid 30s have opted to lower min T
for some of the typically colder valley locations a couple of
degrees on average. Patchy frost will be possible in some of these
locations.
&&
.SHORT TERM...(This evening through Sunday night)
Issued at 345 PM EDT SAT OCT 22 2016
19Z sfc analysis shows high pressure building into the area as low
pressure pulls away to the east. This is working to clear the sky
from west to east as the drier air advects in on northwest winds.
In general, the winds are running at 5 to 10 mph with a few gusts
to 15 mph, or so, thanks to good mixing. The return of sunshine
helped temperatures this afternoon climb into the mid 50s for
most locations while dewpoints mixed down to the low and mid 30s.
These lower dewpoints should make it tougher to get fog late
tonight but may hint at a potential for valley frost.
The models are in good agreement aloft through the short term
portion of the forecast as they all depict a large trough
gradually pivoting out of the Ohio Valley. The core of the initial
trough will depart tonight with heights rising locally, but
additional energy does dive into the Great Lakes, though on a
more shallow trajectory, Sunday night. Given the good model
agreement will favor a blended solution with a lean toward the
higher resolution HRRR and NAM12.
Sensible weather will feature a chilly night with mostly clear
skies and good radiational cooling. This should be enough for
some upper 30s in the valleys and a spot or two of mid 30s where
patchy frost is possible. Do not anticipate the frost being
extensive enough for an advisory tonight as it will be confined
to just the deepest, most sheltered valleys. Accordingly, will
highlight it in the HWO with a the potential for an SPS left to
the following shift. Saturday will be a very nice mid autumn day
with plenty of sunshine, breezy conditions, and temps in the mid
60s. A few wind gusts will approach 30 mph Sunday afternoon over
western parts of our area. Another cool night follows with mostly
clear skies and another ridge to valley temperature split, but
likely not quite cold enough for any frost.
Used the CONSShort and ShortBlend as a starting point for the
grids with some adjustments each night for lows - enhancing the
ridge to valley differences. PoPs are essentially zero - in line
with all guidance.
.LONG TERM...(Monday through Saturday)
Issued at 440 PM EDT SAT OCT 22 2016
The models are in fairly good agreement aloft through the bulk of
the extended. A flat ridge will spread through the South during
the first part of the week before another wave starts developing
over the Northern Plains moving east. It is this wave that leads
to a greater spread in the models as it moves into the Upper
Midwest with the GFS outpacing the ECMWF and both stronger than
the Canadian. The wave deepens into a strong trough Wednesday
into Thursday - deepening substantially as it moves into and
through the Great Lakes to end the work week. Its energy brushes
by the Ohio Valley with its trough axis passing through Kentucky
early Friday. Heights will then rise for next weekend, more so
from the GFS, and quicker, than the ECMWF. Given the broad
agreement through the majority of the period a blend looks to be a
reasonable starting point for the grids.
Sensible weather will feature a fairly nice stretch of weather
through mid to late week with dry conditions and moderating
temperatures. A dry front will shift east of the area Monday with
little change in air mass. The next cold front will move toward
and through the area on Thursday with a decent shot at showers
into Friday morning. Cannot rule out a stray thunderstorm with
this, but given the time of year will wait until it gets closer
to further evaluate the thunder threat. Dry weather follows into
the weekend, but there may be another front worthy of some PoPs by
Saturday afternoon per the GFS and that night in the ECMWF. For
now, will keep it dry Saturday while the models work this
difference out.
The main adjustments to the CR init was to hit the terrain effects
more each night and tighten up the PoPs late in the upcoming work
week.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
ISSUED AT 759 PM EDT SAT OCT 22 2016
VFR conditions will prevail throughout the period as high pressure
dominates. Some river valley fog cannot be ruled out but should
be confined to the deepest river valleys towards dawn and not
impact the TAF sites. Winds will slacken overnight, but pick up
around 15Z with some gusts approaching 20 kts possible under
clear/sunny skies.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JP
SHORT TERM...GREIF
LONG TERM...GREIF
AVIATION...JP
Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
1023 PM CDT SAT OCT 22 2016
.SHORT TERM...(This evening through Sunday)
Issued at 155 PM CDT Sat Oct 22 2016
Dry weather is expected now through Sunday evening. A cold front
will move through the region, but it will pass through dry although
strong winds are expected in its wake. The main story is early
Tuesday into Wednesday as a powerful storm system develops across
the region and brings 1 to 3 inches of rain across southern MN
and western WI.
For today through Sunday, continued with dry weather and breezy
conditions in the wake of the cold front.
.LONG TERM...(Sunday night through Saturday)
Issued at 155 PM CDT Sat Oct 22 2016
Confidence is increasing in rain late Monday into Wednesday
morning. A powerful storm system that is currently over the Gulf
of Alaska will round the base of the trough, while upstream a
longwave trough will remain over eastern Quebec. As a the Pacific
wave crosses the Rockies, it will amplify and the upper level
forcing associated with the curvature of the flow will lead to
widespread ascent, clouds, and precipitation. A
northwest/southeast oriented frontal boundary will serve as the
focus for banded precipitation, and should see stratiform
rainfall rates on the order of 0.25 to 0.50 inches per hour.
Several hours of this precipitation will lead to 2 to 3 inches of
total rainfall, which should fall across southeast MN and west
central WI. This rain will be stratiform, not anticipating any
flash flooding problems. Will likely see ponding of water in low
spots in fields, and some rises on the rivers and small creeks.
Increased pops based on the strength of the system, together with
the model agreement in both time and space, and feel there is
only a 5% chance or so of not seeing measurable precip along
I-90.
Looking ahead, dry weather will settle in for Thursday, and
Friday.
&&
.AVIATION...(For the 06Z TAFS through 06Z Sunday night)
Issued at 1023 PM CDT Sat Oct 22 2016
Few changes made to the TAFs with going forecast looking on track
in terms of timing the wind shift with the low and front coming
through late tonight/early Sunday morning. In addition, confidence
has increased further on MVFR cigs remaining north of the MPX
terminals, save for a small chance for some MVFR cigs at AXN
around 15z.
KMSP...the hrrr has been very stable with its timing of the wind
shift Sunday morning and confidence is high in a 14z fropa.
Confidence is high in the rest of the forecast as well.
/OUTLOOK FOR KMSP/
Mon...VFR. Winds bcmg SE at 5KT.
Tue...BCMG MVFR with -RA. Chc IFR late. Wind ESE at 10G20kt.
Wed...MVFR/IFR/-ra early. Then MVFR. Wind ENE at 5-10kt.
&&
.MPX Watches/Warnings/Advisories...
WI...None.
MN...None.
&&
$$
SHORT TERM...JRB
LONG TERM...JRB
AVIATION...MPG
Area Forecast Discussion
National Weather Service Goodland KS
228 AM MDT Sun Oct 23 2016
.SHORT TERM...(Today through Tuesday night)
Issued at 228 AM MDT Sun Oct 23 2016
Early morning WV imagery and RAP upper level analysis shows broad
ridge still in place across southern plains, with westerly flow
across the northern plains. A shortwave trough is currently moving
east through the main flow across the northern plains with the
southern extent of this feature over our CWa. A weak cold front has
moved into our northern CWA, and is now moving into our NW Kansas
counties.
Today-Tuesday night: Weaker ridging will be in place through Monday
allowing for more of a westerly zonal flow to dominate the Central
High Plains region. A shortwave is still projected to move out of
the northern plains and across Kansas, but as with previous days
trends are towards forcing/deep moisture to remain well east of our
CWA. There is still a weak precip signal Tue evening in our far
southeast, but confidence is low due to current track and the amount
of dry/stable air advecting over our CWA.
Regarding temperatures: Above normal temperatures will continue
today despite the weak cold front passage with upper 60s to lower
70s for most locations. Highs will gradually increase Monday and
Tuesday with 80F temps returning by Tuesday. Tue highs could be
complicated by any lingering stratus, but overall consensus is still
favoring these warmer temps. Lows Monday night could be particularly
mild as Tds increase and stratus may develop.
Regarding fog Monday night/Tuesday morning: NAM/SREF are still
showing a strong fog signal with potential for BL moisture pooling
against surface trough due to moist southeasterly flow. I increased
fog coverage in line with these trends. Potential exists for dense
fog, but GFS is still not showing BL RH quite as favorable for
much of our CWA (more to our northeast). This could be dependent
on timing/position of surface trough as low level flow begins to
shift to the SW behind this feature and drier air advects west to
east.
.LONG TERM...(Wednesday through Saturday)
Issued at 228 AM MDT Sun Oct 23 2016
H5 ridge will build eastward out of the Great Basin as we head into
Wednesday with northwest flow aloft. The axis of the ridge is
expected to remain to our west with its influence extending eastward
through Thursday and Friday, keeping dry air and warmer than normal
temperatures firmly entrenched across the central High Plains. A
shortwave will push across the region Friday with southwest flow out
ahead of the associated cold front. This will serve to bring
temperatures to near or just above 80 degrees on Thursday and
Friday. There could be a fire weather risk for Thursday and Friday
as dew points will be in the 30s in the western half of the CWA with
gusty winds. Cooler air moves in behind the front for Saturday and
Sunday with highs in the upper 60s to near 70 degrees; however this
is still around 5 to 8 degrees above the seasonal average for late
October.
&&
.AVIATION...(For the 06Z TAFS through 06Z Sunday night)
Issued at 1052 PM MDT Sat Oct 22 2016
VFR expected at both KGLD and KMCK through the TAF period. A cold
front will move through the terminals overnight with surface winds
shifting to the north before dawn.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...TL
AVIATION...024
Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
342 AM CDT SUN OCT 23 2016
.SHORT TERM...(Today and tonight)
Issued at 320 AM CDT Sun Oct 23 2016
Early morning water vapor imagery to the north nicely illustrates a
shortwave skirting the International border. This feature will
spread some clouds as far south as central MN/WI today, and spawn a
few showers across the north as well. At this point the forcing and
moisture sufficient for precipitation look to stay mostly north of
the forecast area, although a few early afternoon showers could make
it as far south as Ladysmith, WI. Breezy northwest winds will
develop this morning and afternoon as the associated surface trough
passes. The attendant cool air advection will cause temperatures to
be 5-10 degrees cooler than yesterday, with highs in the lower 50s
to lower 60s anticipated.
Tonight, clouds scatter out and winds become light and variable.
This will make for a chilly night, with Monday morning lows in the
30-35 degree range anticipated.
.LONG TERM...(Monday through Saturday)
Issued at 340 AM CDT Sun Oct 23 2016
Two concerns over the next several days as a strong storm system
begins to organize in the Central Plains and Upper Midwest
Tuesday/Wednesday.
First, precipitation onset remains questionable on Tuesday due to
initial dry air mass to the east and how fast moisture builds
northward across the plains. Due to this drier air mass to the
east, the onset of precipitation could hold off across eastern
Minnesota until late in the afternoon, early evening. West central
Wisconsin may not see any precipitation until late Tuesday
evening, or early Wednesday morning depending upon the strength of
isentropic lift and how it will be oriented from southwest to
northeast.
Secondly, this system is very dynamic and has very high anomalous
water content just to the south of MPX forecast area. Precipitation
water values of 1.0" to 1.2" along the Minnesota/Iowa border are
very rare for late October. Therefore, once this system become
very organized I would expect periods of heavy rainfall once the
setup develops along the nose of the low level jet Tuesday
evening. As with any system, any deviation of this jet and
orientation of the frontal boundary, will shift the heavier
rainfall amounts to the south or north.
Confidence remain very high on a wet period once the
precipitation starts, and will likely not end until the main short
wave moves through Wednesday afternoon/evening.
Further information on how much precipitation could fall is
evident in the latest GEFS QPF ensemble members which have
anywhere from 0.40" to 1.8" for the Twin Cities area by Wednesday
afternoon, with the mean and current operational run (00z/23) of
0.80". Further to the south across Iowa, these ensemble members
increase to 1.0 to nearly 2.4" with a mean and operational run of
1.1".
Past Thursday, the progressive pattern will continue with a long
wave trough across the west coast, and weak ridging across the
plains. This will lead to several fast moving short waves and
associated frontal boundaries across the Upper Midwest by the end
of next week, and into the weekend.
This mean upper flow regime will hold the near or above normal
temperatures profile through the first part of November over the
Upper Midwest. The orientation of the PNA and AO would also suggest
that the warm pattern will continue through the first week of
November. I don`t see any major cold waves until the PNA becomes
more positive or the AO becomes positive.
&&
.AVIATION...(For the 06Z TAFS through 06Z Sunday night)
Issued at 1023 PM CDT Sat Oct 22 2016
Few changes made to the TAFs with going forecast looking on track
in terms of timing the wind shift with the low and front coming
through late tonight/early Sunday morning. In addition, confidence
has increased further on MVFR cigs remaining north of the MPX
terminals, save for a small chance for some MVFR cigs at AXN
around 15z.
KMSP...the hrrr has been very stable with its timing of the wind
shift Sunday morning and confidence is high in a 14z fropa.
Confidence is high in the rest of the forecast as well.
/OUTLOOK FOR KMSP/
Mon...VFR. Winds bcmg SE at 5KT.
Tue...BCMG MVFR with -RA. Chc IFR late. Wind ESE at 10G20kt.
Wed...MVFR/IFR/-ra early. Then MVFR. Wind ENE at 5-10kt.
&&
.MPX Watches/Warnings/Advisories...
WI...None.
MN...None.
&&
$$
SHORT TERM...LS
LONG TERM...JLT
AVIATION...MPG
Area Forecast Discussion
National Weather Service Marquette MI
528 AM EDT Sun Oct 23 2016
.SHORT TERM...(Today and tonight)
Issued at 527 AM EDT SUN OCT 23 2016
Today: A shortwave now moving into northern Mn will slide across the
Upper Great Lakes today. Deepening moisture and deep layer q-vector
convergence associated with this feature and its associated sfc low
moving just south through northern Wi will spread rain showers into
western Upper Mi early this morning and into central and eastern
Upper Mi later this morning into the afternoon. Since this will be a
relatively fast-moving system with limited moisture, expect pcpn to
be fairly light. Temperatures will be a bit cooler than yesterday
with highs topping out in the upper 40s to lower 50s...coolest
northwest half.
Tonight: Increasing cold advection in a north-northwest flow will
lower h85 temps around -5C across eastern Lake Superior resulting in
a lake sfc-h85 delta-t of 17-18c. NAM and RAP Model forecast
soundings show inversion heights around 800 mb or above 5 kft with
lake induced CAPEs at or above 300 j/kg. This instability will be
enough to support scattered lake effect rain showers downwind of
Lake Superior so will maintain high chance pops into Alger-Luce and
northern Schoolcraft counties. Some lake effect showers will also
reach into the eastern portion of Marquette County in the evening
before shifting east overnight as winds back from a 340 (north-
northwest direction) to 320 or due northwest direction. The rest of
the CWA should be dry tonight. Min temps will range from the lower
30s over the interior west to the upper 30s/lower 40s east and along
the Great Lakes shores. Will likely be a bit breezy especially along
the Lake Superior shore from Marquette east to Whitefish Point as
northwest wind gusts may approach 30 mph at times.
.LONG TERM...(Monday through Saturday)
Issued at 344 AM EDT SUN OCT 23 2016
Highly amplified pattern aloft to start the week with deep trough
over Quebec and New England while sharp ridge builds over most of
west half of the Conus. NW flow across Lk Superior Mon-Mon night
will be seasonably chilly with h85 temps around -6c. These temps
along with Lk Superior water temps 10-13c will lead to sufficient
over-water instability for lake effect showers /rain as ptype per
wbzero heights over 1000ft agl/ with delta t/s 16-19c. Soundings
show unfavorable setup for lake effect over western Lk
Superior/western cwa with inversions less than 2kft while longer
over water fetch and cooler air aloft with inversions up to 6kft
over eastern Lk Superior/eastern cwa results in better chance of
at least scattered lake effect showers.
Could see isolated lake effect showers trying to move into the
ncntrl late Mon night into Tue morning as high pressure builds
across northern Ontario and ridge slides over western cwa. Ptype a
bit more tricky than in the east as wbzero lowering to 500-1000 agl
and onshore/upslope northeast winds could result in some snow mixing
in with the rain. Dry air blo inversion should limit coverage of
lake effect into Tue morning.
Attn late Tue night into Wed will be on shortwave crossing the
central plains that undercuts the ridge in place and an associated
sfc low pressure and warm front. Sfc-h85 lows remain south of Upper
Michigan so that likely will limit widespread precip with this lead
shortwave/sfc low. NAM is strongest with the sfc low/dry air holding
the initial surge of precip well to the south over southern WI
through 12z Wed. Even if precip begins to affect cwa later on Wed, as
the previous shift alluded to the main period of concern is Wed night
into Thu as this initial system may merge with another system
approaching in nw flow aloft. Depending how quickly this phasing
occurs, sfc low may track farther north across Lk Michigan and
northern lower MI and there would be enough precip and cold air
around to result in a mix of rain/snow mainly over west and ncntrl
cwa on Wed Night and possibly over parts of the east cwa later Thu.
Only a few model runs from the GFS/ECMWF/GEM have been completely
phased aloft/far enough north with sfc low/cold enough in terms of
h85 temps and low enough in terms of 1000-850mb thickness to support
accumulating snow Wed Night into Thu. Forecast sfc temps in the mid
30s Wed night into Thu morning also suggest minimal snow accumulation
as long as the more intense forecasts with regard to stronger low-mid
level forcing do not materialize. Degree of phasing aloft with this
system will be bigger thing to watch in the coming days as that will
affect how far north the sfc low tracks and how much cold air can
occur with a deepening system. Will keep with mix of rain and snow,
similar to previous forecast.
After the initial shortwave/sfc low tracks east of the Upper Great
Lakes Thu night into Fri, will still have scattered lake effect
showers continuing. Decent agreement that h85 temps will be down to
at least -6c across Lk Superior which with sufficient h85 moisture
and indication of stronger low-level convergence with lake induced
troughing should be enough to support the scattered lake effect
rain/snow showers. If stronger shortwave drops through in this flow
pattern with this already favorable low-level environment, then
coverage and intensity of the lake effect would increase late Thu
night into Fri.
&&
.AVIATION...(For the 06Z TAFS through 06Z Sunday night)
Issued at 140 AM EDT SUN OCT 23 2016
VFR conditions will prevail at all TAF sites overnight. Low pressure
will approach the area Sunday morning bringing the possibility of
rain showers at each of the TAF sites along with MVFR ceilings.
Conditions will improve to VFR by Sun evening at IWD as drier air
moves back in behind the low.
&&
.MARINE...(For the 4 AM Lake Superior forecast issuance)
Issued at 527 AM EDT SUN OCT 23 2016
Winds will remain below gales through the period. A tightening
gradient between a deep low pressure system moving through Quebec
and a high pressure ridge building into the Plains could lead to a
period of NW winds gusting to 30 knots over eastern Lake Superior
tonight into Monday. High pressure will build across the area Monday
afternoon through Wednesday, keeping winds generally light across
Lake Superior. There will be a trough passage on Thu but winds
will remain fairly light.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
None.
Lake Michigan...
None.
&&
$$
SHORT TERM...Voss
LONG TERM...JLA
AVIATION...07
MARINE...Voss
Area Forecast Discussion
National Weather Service Binghamton NY
1126 AM EDT Sun Oct 23 2016
.SYNOPSIS...
A strong low pressure system over eastern Canada will keep windy
and cool conditions over the region today. A fairly weak fast
moving disturbance will bring a quick shot of rain showers tonight
especially over the southern tier and northeast Pennsylvania. Monday
and Tuesday will be brisk and cold with high temperatures only in
the forties to around fifty.
&&
.NEAR TERM /THROUGH MONDAY/...
Updated at 11 am... Lake enhanced clouds continue to cover the
western 2/3 of the forecast area generally along and west of I-81
late this morning. Expect these clouds to linger into this
afternoon. Meanwhile another band of clouds and possibly even
scattered light showers is expected to develop over and east of
Lake Ontario later this afternoon as the flow goes to more
westerly and weak warm air advection / low-level convergence will
combine with some lake enhancement with 850 mb / lake temperature
differential aboutn +14 expected. The HRRR model in particular is
bullish in showing these showers developing after 5-6 pm.
Temperatures will rise slowly into the upper 40s to mid 50s. Will
keep the wind advisory going for the Catskill mountains into this
afternoon with gusts mainly 30 to 40 mph slowly diminishing by
late in the day. Previous discussion is below. Previous discussion
is below.
Today...A deep 980 mb vertically stacked low pressure system just
north of Maine will gradually continue lifting north into eastern
Canada today. This system will give the region another windy day
with eastern areas expected to see the highest gusts. A wind
advisory will continue for Otsego, Delaware and Sullivan counties
where the higher terrain will see gusts around 45 mph through mid
afternoon. Otherwise it will be a partly cloudy day with highs in
the upper 40s to middle 50s.
Tonight...A fast moving mid level wave in northwest flow will
swing through the region as weak surface low pressure tracks along
the New York/Pennsylvania border. The best timing for rain showers
will be from 03Z-09Z. Will continue with likely pops across much
of northeast Pennsylvania and high chance in the southern tier.
Early this evening as the wave approaches a brief enhancement of
lake effect rain showers may develop southeast of Lake Ontario.
Most models suggest this with the Canadian regional most robust.
Lows will range in the lower to middle 40s.
Monday...Behind this wave a cool northwest flow will develop under
partly cloudy skies. T85 drops to around -5C by midday under 300
flow so will keep slight chance pops for rain showers using this
orientation. Activity is mot expected to be widespread as airmass
is fairly dry. Highs will range in the middle 40s to around 50.
&&
.SHORT TERM /MONDAY NIGHT THROUGH TUESDAY NIGHT/...
This entire period a deep northwest flow of cold air as 850mb temps
fall to -8C. To start the low level flow is 300 but it goes to 330
or 340. This directions means multibands and light amounts.
Connection to Lake Huron may end so only a short fetch of Lake
Ontario to grab moisture. Dry air above this shallow moisture. Cold
enough with the dendrite zone at the top of the shallow moisture.
Snow accumulations will be light and mostly across the higher
elevations at night.
Low temperatures in the 30s Monday night rise into the 40s Tuesday
then drop to around 30 Tuesday night.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
A cool unsettled period with a nearly stationary upper level trough
over the northeast US. Cooler than normal to start then warming to
near normal next weekend. To start highs Wed and Thu only in the 40s
with lows around 30 Wed ngt. Warms to highs in the 50s Friday and
Saturday with lows around 40.
High pressure Wednesday moves through quickly. This followed by
strengthening of the trough as a surface low moves northeast through
the lower Great Lakes Thursday to Friday. If showers move in early
enough Thursday it could be a mix of snow and rain. Temperatures
will be around freezing. Some difference on timing with the Euro
slower than the GFS. Also the Euro is slower keeping the showers
into Saturday while the GFS is dry. Keep rain showers going into
Saturday. Given the source of the moisture rainfall amounts do not
look light even with the long duration.
&&
.AVIATION /15Z SUNDAY THROUGH THURSDAY/...
Winds will be the main aviation concern today with west/northwest
winds of 15-20 knots with gusts around 30 knots decreasing by mid
afternoon and becoming southwest this evening around 5 knots. Late
in the TAF period the winds will shift to the northwest around
5-10 knots.
VFR conditions are expected through early this evening. Ceilings
through today will be around 4k ft. Tonight a fast moving system
will bring MVFR ceilings to the southern terminals after 06Z with
vsby restrictions in showers at KELM/KBGM/KAVP.
OUTLOOK...
Monday...Restrictions possible as weak system moves through.
Tuesday - Wednesday...Mainly VFR.
Thursday...MVFR possible in showers.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...None.
NY...Wind Advisory until 6 PM EDT this evening for NYZ046-057-062.
&&
$$
SYNOPSIS...RRM
NEAR TERM...MSE/RRM
SHORT TERM...TAC
LONG TERM...TAC
AVIATION...RRM
Area Forecast Discussion
National Weather Service Bismarck ND
822 AM CDT Sun Oct 23 2016
.UPDATE...
Issued at 819 AM CDT Sun Oct 23 2016
Added areas of dense fog for a few hours southwest. ND DOT webcams
show fog at Dickinson, Trotters and Belfield. This is on the
southern edge of the cloud deck. Anticipate the fog will graduallylift
by mid morning.
UPDATE Issued at 622 AM CDT Sun Oct 23 2016
Forecast pretty much on track early this morning. Stratus has
dropped south to nearly Dickinson to Bismarck and Jamestown line.
Updated sky cover based on latest satellite imagery. Maybe a
sprinkle or two around the Turtle Mountains but otherwise
precipitation has ended. Just this past hour a couple of areas of
fog have developed (Sidney MT and Tioga) and HRRR still indicates
fog along the western fringes of the stratus layer. With light
winds and low temp/dwpt spreads from Williston down to Beach and
Dickinson, will add a few hours of patchy fog this morning. Winds
remain gusty over eastern portions of central ND but expect these
winds to continue to diminish through mid morning.
&&
.SHORT TERM...(Today and tonight)
Issued at 237 AM CDT Sun Oct 23 2016
A breezy start to the day south central with considerable clouds
northwest and central ND. Winds will quickly diminish this
morning with diminishing clouds from west to east by afternoon.
Currently, low pressure is situated over the Red River Valley
with pressure rises behind the low tracking across central ND.
This is producing some gusty winds across central ND Wrap around
moisture in the form of stratus is pushing southward across
western and central ND with any light precipitation remaining over
the Turtle Mountains area in the far north central.
Will likely bump up winds a bit early this morning based on
latest guidance. Have yet to see any fog development on the west
side of the stratus shield. Will remove the mention of fog this
morning unless we see some development before pushing out the new
package.
Surface high pressure tracks east across the forecast area today
so after this morning, expect light winds with a southeast flow
developing in the west by this afternoon. Given our warm start
went a little above guidance for temperatures except for eastern
portions of central ND. The southwest may well escape the low
stratus today. Elsewhere, mostly cloudy this morning with clouds
diminishing from west to east during the day. Highs today ranging
from the mid 40s northeast to mid 50s southwest.
High pressure over the area early tonight slides into Minnesota by
12 UTC Monday. Should have pretty good radiational cooling,
especially east and have lowered lows from given guidance. One
possible fly in the ointment will be the possibility of increasing
low stratus/fog after midnight with increasing low level moisture
in a southeast flow. Models agree on increasing low level moisture
and have increased clouds late tonight but still think there is
enough time to drop down a few degrees below guidance lows.
.LONG TERM...(Monday through Saturday)
Issued at 237 AM CDT Sun Oct 23 2016
Continued seasonable to mild through the extended period with a
few chances of showers as shortwave impulses work through a mean
western ridge.
Southeast flow continues on Monday and Monday night with
increasing low level moisture as an upper level ridge tracks
across the northern plains. a Pair of shortwaves moving through
the mean ridge bring a chance of showers to the area Tuesday
through Wednesday. The first tracks across South Dakota but models
are in reasonable agreement in bringing showers into south central
ND perhaps as early as late Monday night but certainly by Tuesday.
The second northern stream wave and its associated surface trough
keeps a southerly fetch of moisture through ND and into southern
Canada, with enough mid level forcing to induce showers northward
through all of central ND. Given guidance has a pretty good handle
on this, but we did pull the chance of showers farther north and
west Tuesday afternoon and Tuesday night. The best probability for
precipitation with these waves will be over the James River Valley
east into the southern Red River Valley Tuesday afternoon and
evening, with mainly isolated to scattered showers over the
northwest and remainder of the central Tuesday afternoon and
Tuesday night. The southwest is expected to remain mainly dry.
Upper level ridging builds behind these waves Wednesday night and
Thursday. After that there is considerable models differences in
how energy from another eastern Pacific low translates east across
the continental U.S. Will probably see a couple chances of light
precipiation somewhere in the forecast area late week into next
weekend but at this time model differences are great enough that
the blended guidance is not producing any significant
precipitation chances. We still remain seasonable to mild for
temperatures through the extended period.
&&
.AVIATION...(For the 12Z TAFS through 12Z Monday morning)
Issued at 622 AM CDT Sun Oct 23 2016
A low pressure center/cold front was over Minnesota/Iowa at 630 AM
CDT...and will continue moving east today. A large cloud
shield of MVFR and occasional IFR stratus behind the cold front
encompassed much of south central Canada and northern ND. This band
of MVFR stratus will continue moving southeast. Expect stratus to
begin dissipating during the early/mid afternoon hours. MVFR to IFR
vsbys in fog are possible at KISN on the western edge of the clouds
early this morning.
Gusty west/northwest winds behind the front at KJMS should decrease
with time this morning.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...WAA
SHORT TERM...TWH
LONG TERM...TWH
AVIATION...TWH
Area Forecast Discussion
National Weather Service Goodland KS
946 AM MDT Sun Oct 23 2016
.UPDATE...
Issued at 946 AM MDT Sun Oct 23 2016
Overall forecast in great shape as region under sunny skies with
temps currently in the 50s. Winds NNE in the 10 to 20 mph range...
especially in KS/NE. Some locales were a bit underdone based on
current obs...so have tweaked winds up thru the next couple hours.
&&
.SHORT TERM...(Today through Tuesday night)
Issued at 228 AM MDT Sun Oct 23 2016
Early morning WV imagery and RAP upper level analysis shows broad
ridge still in place across southern plains, with westerly flow
across the northern plains. A shortwave trough is currently moving
east through the main flow across the northern plains with the
southern extent of this feature over our CWa. A weak cold front has
moved into our northern CWA, and is now moving into our NW Kansas
counties.
Today-Tuesday night: Weaker ridging will be in place through Monday
allowing for more of a westerly zonal flow to dominate the Central
High Plains region. A shortwave is still projected to move out of
the northern plains and across Kansas, but as with previous days
trends are towards forcing/deep moisture to remain well east of our
CWA. There is still a weak precip signal Tue evening in our far
southeast, but confidence is low due to current track and the amount
of dry/stable air advecting over our CWA.
Regarding temperatures: Above normal temperatures will continue
today despite the weak cold front passage with upper 60s to lower
70s for most locations. Highs will gradually increase Monday and
Tuesday with 80F temps returning by Tuesday. Tue highs could be
complicated by any lingering stratus, but overall consensus is still
favoring these warmer temps. Lows Monday night could be particularly
mild as Tds increase and stratus may develop.
Regarding fog Monday night/Tuesday morning: NAM/SREF are still
showing a strong fog signal with potential for BL moisture pooling
against surface trough due to moist southeasterly flow. I increased
fog coverage in line with these trends. Potential exists for dense
fog, but GFS is still not showing BL RH quite as favorable for
much of our CWA (more to our northeast). This could be dependent
on timing/position of surface trough as low level flow begins to
shift to the SW behind this feature and drier air advects west to
east.
.LONG TERM...(Wednesday through Saturday)
Issued at 228 AM MDT Sun Oct 23 2016
H5 ridge will build eastward out of the Great Basin as we head into
Wednesday with northwest flow aloft. The axis of the ridge is
expected to remain to our west with its influence extending eastward
through Thursday and Friday, keeping dry air and warmer than normal
temperatures firmly entrenched across the central High Plains. A
shortwave will push across the region Friday with southwest flow out
ahead of the associated cold front. This will serve to bring
temperatures to near or just above 80 degrees on Thursday and
Friday. There could be a fire weather risk for Thursday and Friday
as dew points will be in the 30s in the western half of the CWA with
gusty winds. Cooler air moves in behind the front for Saturday and
Sunday with highs in the upper 60s to near 70 degrees; however this
is still around 5 to 8 degrees above the seasonal average for late
October.
&&
.AVIATION...(For the 12Z TAFS through 12Z Monday morning)
Issued at 516 AM MDT Sun Oct 23 2016
VFR conditions are expected through the TAF period at KGLD and
KMCK terminals. Winds have shifted to the north behind a front
that is now in SW Kansas. A brief period of low level wind shear
is ongoing behind this front, but should end as a LLJ transitions
southward early in the TAF period. There will be a slight increase
in winds from the northeast this morning with gusts 15-20kt
possible at KGLD. Winds eventually decrease below 12kt this
afternoon at both terminals, and shift from the northeast to the
east and then southeast as high pressure settles into the plains.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JN
SHORT TERM...DR
LONG TERM...TL
AVIATION...DR
Area Forecast Discussion
National Weather Service Marquette MI
752 AM EDT Sun Oct 23 2016
.SHORT TERM...(Today and tonight)
Issued at 527 AM EDT SUN OCT 23 2016
Today: A shortwave now moving into northern Mn will slide across the
Upper Great Lakes today. Deepening moisture and deep layer q-vector
convergence associated with this feature and its associated sfc low
moving just south through northern Wi will spread rain showers into
western Upper Mi early this morning and into central and eastern
Upper Mi later this morning into the afternoon. Since this will be a
relatively fast-moving system with limited moisture, expect pcpn to
be fairly light. Temperatures will be a bit cooler than yesterday
with highs topping out in the upper 40s to lower 50s...coolest
northwest half.
Tonight: Increasing cold advection in a north-northwest flow will
lower h85 temps around -5C across eastern Lake Superior resulting in
a lake sfc-h85 delta-t of 17-18c. NAM and RAP Model forecast
soundings show inversion heights around 800 mb or above 5 kft with
lake induced CAPEs at or above 300 j/kg. This instability will be
enough to support scattered lake effect rain showers downwind of
Lake Superior so will maintain high chance pops into Alger-Luce and
northern Schoolcraft counties. Some lake effect showers will also
reach into the eastern portion of Marquette County in the evening
before shifting east overnight as winds back from a 340 (north-
northwest direction) to 320 or due northwest direction. The rest of
the CWA should be dry tonight. Min temps will range from the lower
30s over the interior west to the upper 30s/lower 40s east and along
the Great Lakes shores. Will likely be a bit breezy especially along
the Lake Superior shore from Marquette east to Whitefish Point as
northwest wind gusts may approach 30 mph at times.
.LONG TERM...(Monday through Saturday)
Issued at 344 AM EDT SUN OCT 23 2016
Highly amplified pattern aloft to start the week with deep trough
over Quebec and New England while sharp ridge builds over most of
west half of the Conus. NW flow across Lk Superior Mon-Mon night
will be seasonably chilly with h85 temps around -6c. These temps
along with Lk Superior water temps 10-13c will lead to sufficient
over-water instability for lake effect showers /rain as ptype per
wbzero heights over 1000ft agl/ with delta t/s 16-19c. Soundings
show unfavorable setup for lake effect over western Lk
Superior/western cwa with inversions less than 2kft while longer
over water fetch and cooler air aloft with inversions up to 6kft
over eastern Lk Superior/eastern cwa results in better chance of
at least scattered lake effect showers.
Could see isolated lake effect showers trying to move into the
ncntrl late Mon night into Tue morning as high pressure builds
across northern Ontario and ridge slides over western cwa. Ptype a
bit more tricky than in the east as wbzero lowering to 500-1000 agl
and onshore/upslope northeast winds could result in some snow mixing
in with the rain. Dry air blo inversion should limit coverage of
lake effect into Tue morning.
Attn late Tue night into Wed will be on shortwave crossing the
central plains that undercuts the ridge in place and an associated
sfc low pressure and warm front. Sfc-h85 lows remain south of Upper
Michigan so that likely will limit widespread precip with this lead
shortwave/sfc low. NAM is strongest with the sfc low/dry air holding
the initial surge of precip well to the south over southern WI
through 12z Wed. Even if precip begins to affect cwa later on Wed, as
the previous shift alluded to the main period of concern is Wed night
into Thu as this initial system may merge with another system
approaching in nw flow aloft. Depending how quickly this phasing
occurs, sfc low may track farther north across Lk Michigan and
northern lower MI and there would be enough precip and cold air
around to result in a mix of rain/snow mainly over west and ncntrl
cwa on Wed Night and possibly over parts of the east cwa later Thu.
Only a few model runs from the GFS/ECMWF/GEM have been completely
phased aloft/far enough north with sfc low/cold enough in terms of
h85 temps and low enough in terms of 1000-850mb thickness to support
accumulating snow Wed Night into Thu. Forecast sfc temps in the mid
30s Wed night into Thu morning also suggest minimal snow accumulation
as long as the more intense forecasts with regard to stronger low-mid
level forcing do not materialize. Degree of phasing aloft with this
system will be bigger thing to watch in the coming days as that will
affect how far north the sfc low tracks and how much cold air can
occur with a deepening system. Will keep with mix of rain and snow,
similar to previous forecast.
After the initial shortwave/sfc low tracks east of the Upper Great
Lakes Thu night into Fri, will still have scattered lake effect
showers continuing. Decent agreement that h85 temps will be down to
at least -6c across Lk Superior which with sufficient h85 moisture
and indication of stronger low-level convergence with lake induced
troughing should be enough to support the scattered lake effect
rain/snow showers. If stronger shortwave drops through in this flow
pattern with this already favorable low-level environment, then
coverage and intensity of the lake effect would increase late Thu
night into Fri.
&&
.AVIATION...(For the 12Z TAFS through 12Z Monday morning)
Issued at 729 AM EDT SUN OCT 23 2016
VFR conditions will prevail at all TAF sites into this morning, but
then approaching low pressure from the Northern Plains will spread rain
into the area as conditions lower to MVFR at each of the TAF sites by
the afternoon. Expect conditions to improve back to VFR by this
evening at IWD and CMX as drier air moves in with the advance of high
pressure from the west.
&&
.MARINE...(For the 4 AM Lake Superior forecast issuance)
Issued at 527 AM EDT SUN OCT 23 2016
Winds will remain below gales through the period. A tightening
gradient between a deep low pressure system moving through Quebec
and a high pressure ridge building into the Plains could lead to a
period of NW winds gusting to 30 knots over eastern Lake Superior
tonight into Monday. High pressure will build across the area Monday
afternoon through Wednesday, keeping winds generally light across
Lake Superior. There will be a trough passage on Thu but winds
will remain fairly light.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
None.
Lake Michigan...
None.
&&
$$
SHORT TERM...Voss
LONG TERM...JLA
AVIATION...Voss
MARINE...Voss
Area Forecast Discussion
National Weather Service Bismarck ND
328 PM CDT Sun Oct 23 2016
.SHORT TERM...(This evening through Monday)
Issued at 248 PM CDT Sun Oct 23 2016
Focus in the short term is on cloud cover and the potential for
fog tonight into Monday morning.
Model guidance has had a difficult time with cloud cover through
the day as in most places clouds stuck around a bit longer than
previous thought. Latest HRRR runs show clouds more or less
sticking around central and north through the night while other
models are more optimistic that central and north may clear out.
Went with a blend of models through the night but will have to
keep a close eye on it as cloud cover will play a role on if and
how much fog develops overnight and overnight lows in the James
River Valley.
As for fog the NAM has done a good job the past two nights of
showing where fog will develop. Tonight into Monday morning the
best chance appears to be north central and northwest with some
potential development across the central and west early Monday
morning. Low level moisture will be ample across the area, however
depending on when southeasterly winds pick up across the southwest
and cloud cover south central will play a large role in whether or
not fog develops.
.LONG TERM...(Monday night through Sunday)
Issued at 248 PM CDT Sun Oct 23 2016
Focus in the long term is on the chances for rain Tuesday into
Wednesday.
Model guidance continues to show two upper level troughs develop in
the mean ridge Tuesday and Wednesday. The best chance for rain
comes from the southern wave that develops over the central
plains. Wrap around precipitation will bring rain to the
southeastern part of North Dakota Tuesday afternoon into early
Wednesday morning.
The second wave develops further north in Canada and progresses
more slowly. Model guidance is in less agreement on the track of
this upper level wave. Latest solutions of the ECMWF show chances
for rain across much of North Dakota for most of Wednesday while
the latest GFS solution keeps precipitation north of the border.
Either way any rain would be light across northern North Dakota
and for now have went with chances for rain for north central and
northeast.
&&
.AVIATION...(For the 18Z TAFS through 18Z Monday afternoon)
Issued at 1215 PM CDT Sun Oct 23 2016
Surface high pressure over the northern plains will drift east
today and tonight. The large stratus region will gradually break
up by late this afternoon. MVFR will become vfr across the region
between 21-23z.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...MM
LONG TERM...MM
AVIATION...WAA
AREA FORECAST DISCUSSION
National Weather Service Jackson KY
430 PM EDT Sun Oct 23 2016
.SHORT TERM...(This evening through Monday night)
Issued at 430 PM EDT SUN OCT 23 2016
19z sfc analysis shows high pressure to the south starting to
yield to an inbound dry cold front to the northwest. This front`s
approach is responsible for the tightening pressure gradient
helping, along with good mixing under sunny conditions, to keep
the winds going from the southwest at 10 to 15 mph, or so, with
occasional gusts around 25 mph. These breezes, again along with
the full sunshine, support temperatures climbing into the upper
60s and low 70s. Dewpoints, meanwhile, are running in the upper
30s to lower 40s.
The models remain in good agreement aloft through the short term
portion of the forecast as they all show Kentucky in the midst of
fairly fast northwest flow between a deep trough to the northeast
and rather flat ridging west. A weak trough will pass by to the
north tonight into Monday morning but its energy stays well off to
the northeast to have any real affect on our weather. Given the
good agreement have favored a general blend with emphasis on the
higher resolution guidance from the HRRR and NAM12, along with
some deference to the COOP MOS guidance - especially Monday
night.
Sensible weather will feature a bit milder of a night as the winds
stay up better and the front limits the strength of the inversion.
Will allow for some river valley fog near dawn as we have had the
past couple of mornings. Another pleasant day is expected on
Monday with mostly sunny skies, breezy winds switching to the
northwest post fropa, and afternoon temperatures in the mid to
upper 60s. Drier and cooler air moves in Monday night with a
better potential for frost in the valleys early Tuesday morning.
Have added that to the grids along with a mention in the HWO.
Again used the CONSShort/ShortBlend as the starting point for the
bulk of the grids with adjustments to the night-time temps for
terrain as well as knocking dewpoints down in the afternoon a tad.
PoPs were zeroed out through the period - in line with all
guidance.
.LONG TERM...(Tuesday through Sunday)
Issued at 345 PM EDT SUN OCT 23 2016
The models are in good agreement through the work week then diverge
in their solutions. At the start of the period, heights will rise as
high pressure scoots into the area from the south. This high
pressure will be over the region Tuesday afternoon through Wednesday
morning, allowing lower dew points to mix down. This will lead to
the best chance of the period for some patchy frost Wednesday
morning. Winds shift to the southwest ahead of a shortwave trough
passage, allowing for warmer and moist air to infiltrate the region
Wednesday afternoon. A cold front is then expected to swing through
East Kentucky by Thursday evening with a chance for some showers
throughout the day. High pressure shifts into the area Thursday
night but quickly exits by Friday evening. Beyond Friday, the
forecast is a bit up in the air as model solutions diverge. So have
decided to remain close to the CR Superblend solution beyond Friday,
with minor changes made to the temperatures to account for night-
time inversions.
Temperatures will remain fairly seasonable through the period with
afternoon highs in the 60s and low 70s. Morning lows will start out
near freezing in the valleys on Wednesday morning, with all temps
moderating into the 40s/low 50s through the rest of the period.
&&
.AVIATION...(For the 18Z TAFS through 18Z Monday afternoon)
ISSUED AT 240 PM EDT SUN OCT 23 2016
VFR conditions are expected through the period. Winds will be the
main concern this afternoon, as a cold front approaches from the
northwest. Southwest winds will be 10 kts, with gusts up to 15 and
20 kts through late afternoon. Winds will then diminish to between
and 5 and 10 kts by early this evening and continue that way
through the night before picking up again during the day Monday.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...GREIF
LONG TERM...JVM
AVIATION...GREIF
Area Forecast Discussion...UPDATED
National Weather Service North Platte NE
555 PM CDT Sun Oct 23 2016
.SYNOPSIS...
Issued at 306 PM CDT Sun Oct 23 2016
H5 hand analysis this morning had a continuation of the
broad ridging across the western and central portions of the CONUS.
Ridging aloft extended north into northern British Columbia and was
amplified by an upstream low off the coast of British Columbia.
The pattern across the western and central CONUS remains stagnant
this morning as little or no ht rises or falls were noted west of
the Mississippi river. Further east, a closed low was located over
southeastern Quebec with a trough of low pressure extending south
into New England. Ht. falls of 50 to 200 meters were from Maine
into the Canadian Maritimes. Further south, 50 to 100 meter rises
were noted over the Ohio Valley into the Carolinas. At the surface,
a cold front had passed through western and north central Nebraska
overnight and currently extended from southwestern Kansas into
northwestern Missouri. Skies were generally clear this afternoon
across the forecast area, with the exception of some mountain wave
cirrus across the southern third of the forecast area and some low
cloudiness trying to back into northeastern Nebraska from eastern
South Dakota. Afternoon temperatures as of 3 PM CDT ranged from 62
at Ainsworth to 67 at North Platte and Broken Bow.
&&
.UPDATE...
Issued at 554 PM CDT Sun Oct 23 2016
The ARW...NMM....HRRR and RAP models show some fog by morning
along highway 281. This would form near sunrise and lift mid to
late morning. The RAP model sounding seems conceivable so a new
forecast is in place for this feature.
&&
.SHORT TERM...(This evening through Monday)
Issued at 306 PM CDT Sun Oct 23 2016
Upper level ridging continues across the Rocky Mountain region as
high pressure slides slowly eastward across the upper Midwest.
Similar to the previous several days, quiet and dry conditions will
prevail. Clear skies tonight will allow temperatures to fall into
the mid to upper 30s across the forecast area.
On Monday, will continue to see dry weather, however, skies will
slowly become more cloudy throughout the day in advance of the
shortwave trough moving off the front ranges. This filtering in of
clouds from the west combined with cooler air filtering in on the
western side of the surface high will keep high temperatures across
the eastern forecast area a few degrees cooler than the last couple
days. Expect highs in the low to mid 60s across the eastern CWA.
Areas to the west across the eastern panhandle will still see highs
in the low 70s.
.LONG TERM...(Monday night through Sunday)
Issued at 306 PM CDT Sun Oct 23 2016
Monday night through Wednesday...In the mid range, the
main forecast challenges deal with the development of low clouds
and fog Monday night, along with the threat for precipitation
development Tuesday afternoon and Tuesday Night. For Monday night:
Thanks to increasing southeast winds, strong low level moisture
advection will commence across the forecast area, mainly east of the
Nebraska Panhandle. Dew points will increase into the middle and
upper 40s overnight which will lead to lows in the mid and upper 40s
Monday night-some 10 to 15 degrees above normal. Coverage of low
cloudiness will increase as well and as this cloudiness moves west,
fog will develop along the leading edge of the stratus. NAM12 BL RH
progs, as well as SREF fog probabilities indicate a high potential
for fog Monday night into Tuesday morning east of the panhandle and
west of a line from Valentine to Broken Bow. Ongoing forecast has
this mentioned right now and will be increasing coverage especially
over southwestern Nebraska based on the latest NAM12 and SREF visby
products which do indicate a high probability for fog development.
For Tuesday, fog and stratus will be slow to burn off from west to
east as a surface trough will track slowly from western into
central portions of the forecast area on Tuesday. The latest NAM12
is slightly faster with the track of the surface trough Tuesday
while the GFS20 is slower. This will limit any clearing along and
east of highway 83 Tuesday, leading to cooler temps in the eastern
forecast area given the expected cloud cover. Later in the
afternoon and evening, precipitation chances will increase in the
eastern forecast area, as a shortwave trough aloft, approaches the
surface trough. The models this morning are much weaker with the
capping inversion Tuesday afternoon/evening than yesterday`s runs,
which increases the confidence in thunderstorm development in the
east Tuesday night. Did make some changes to precipitation chances
in the east Tuesday afternoon/evening, mainly to draw pops further
west, however, they are still east of the highway 83 corridor.
Overnight, Tuesday night, the surface trough and upper level
disturbance will track slowly east-stalling across eastern
Nebraska. Boundary layer moisture will remain prevalent in the
northeastern forecast area, so low clouds are expected to persist
into Wednesday morning and possibly Wednesday afternoon in eastern
portions of the forecast area.
Wednesday Night through Sunday...Ridging will build back into the
central CONUS for Wednesday Night into Thursday Night. Temperatures
on Thursday may hit the lower 80s in far southwestern Nebraska as
H85 temps surge into the lower 20sC. This ridging will be short
lived however as a northern stream shortwave trough suppresses the
ridge-forcing a cold front into the forecast area later in the week.
There are some timing differences between the EC and GFS solutions
with their timing of this feature. The EC is 24 to 36 hours slower
with the front, so warm temperatures will carry over into Friday and
Saturday. Given the differences between the model solutions,
utilized the forecast blend for highs. As for lows, with a dry
airmass in place, blended lows were undercut 2 to 4 degrees to
better reflect the statistical guidance as well as climatology.
&&
.AVIATION...(For the 18Z TAFS through 18Z Monday afternoon)
Issued at 1254 PM CDT Sun Oct 23 2016
An upper level ridge will remain in place over the next 24 hours
keeping aviation conditions dry and quiet. Only major concern at
both terminals will be a change in wind direction overnight from a
north/northeasterly direction to a southeasterly direction by Monday
morning. Southeasterly wind gusts also increase to near 20 knots at
KVTN by late Monday afternoon. Gusts are expected to remain below 15
knots at KLBF.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
UPDATE...CDC
SYNOPSIS...Buttler
SHORT TERM...Kulik
LONG TERM...Buttler
AVIATION...Kulik
Area Forecast Discussion
National Weather Service Phoenix AZ
218 PM MST SUN OCT 23 2016
.SYNOPSIS...
A low pressure system will move towards the Pacific Northwest early
this week. This storm system will draw a considerable amount of
subtropical moisture into the Desert Southwest with the threat of
isolated showers and thunderstorms starting this evening and
continuing through Monday night. The best chance of showers will
occur Monday over south central Arizona, with afternoon thunderstorms
possible. Drier and warmer conditions will return by the middle of
the week.
&&
.DISCUSSION...
Latest streamline analysis shows a broad ridge encompassing the
southern states while a low pressure system in the eastern Pacific
approaches the Pacific Northwest. Southwesterly flow between these
two systems is transporting warm and moist air from the subtropics
into the region. In the lower levels, dewpoints have jumped abruptly into
the mid 60s across the Yuma in response to the low-level southerly
flow. Further east across southeastern Arizona, latest satellite
imagery shows that isolated convection has initiated, mainly across
the higher terrain.
Steering flow is generally 10 kt or less associated with the 700 mb
anticyclone centered near Nogales and the existing activity is not
expected to move towards central Arizona. However, some CAMs suggest
isolated cells will drift into portions of Pima and Pinal Counties
late this afternoon, though latest runs of the HRRR continue to
indicate little potential for convection this far north. PoPs were
again lowered slightly from Phoenix northward, but raised across
southwestern Maricopa County, albeit to only around 20 percent. Hi-
res guidance remains in good agreement that any activity that
develops will likely dissipate this evening.
Deeper moisture will continue to stream northeastward ahead of an
approaching southern-stream short-wave trough Monday. NAEFS IVT
appears to be strongest across southern CA and western AZ during the
late morning and early afternoon with a widespread area exceeding the
95th percentile. Nearly all CAMs are suggesting a large shield of
clouds/light rain and sprinkles will encompass the area during the
afternoon. Global models are also indicating that areas that see
less clouds will destabilize, supporting 100-300 J/kg of SBCAPE.
Conceptually, the best chance for precipitation will actually be
during the evening across central Arizona, when forcing for ascent is
maximized ahead of the vort max. Although organized thunderstorms are
not expected, SPC probabilities indicate at least a slight chance of
thunder across much of the area into the evening.
.PREVIOUS DISCUSSION...
A gradual clearing and drying trend from the west is expected Monday
night into Tuesday as the last short wave moves through central
Arizona and then quickly exits east into New Mexico, followed by
building high pressure and increasing subsidence. By Tuesday morning
there should be just a lingering slight chance of showers over the
higher terrain east of Phoenix with mostly sunny skies developing
over the central and western deserts. High temps will climb slightly
Tuesday and into the low 90s from Phoenix westward due to increasing
sunshine and mixing.
For Wednesday into Thursday, strong high pressure aloft is forecast
to build back into the desert southwest, as another large area of
low pressure sets up just off the west coast and pumps up the ridge
downstream and over our area. High temps will climb back into the
middle 90s, with a high of 95 forecast in Phoenix by Thursday; that
would be over 10 degrees above seasonal normals. It should stay dry
for the most part, though a minor short wave lifting out of the deep
trof will brush by far southeast California Thursday leading to a
slight chance of a shower over the higher terrain of Joshua Tree NP.
Latest ECMWF and GFS have come into much better agreement for the
latter portion of the extended forecast, and the GEFS members also
have come into better alignment; we expect that in general the ridge
will remain rather strong over the desert southwest but there will
be continued short waves moving out of the trof along the west
coast, riding across and over the top of the ridge and bringing in
some modest moisture and UVV, enough to warrant a slight chance of
showers over the western deserts - mainly over higher terrain areas
of southeast CA. The central Arizona deserts should remain dry and
warm through the period however. Latest NAEFS POPs trends also
support the relatively dry conditions during the Friday through
Saturday period.
&&
.AVIATION...South-Central Arizona including KPHX, KIWA, and KSDL:
Southeast California/Southwest Arizona including KIPL and KBLH:
A pacific weather system is expected to pull increasing amounts of
moisture into the region over the next 24 hours. This will result in
increasing mid and high-level cloudiness over the PHX area terminals
through the taf period. Chances for showers, and even an isolated
thunderstorm are also expected to gradually increase through the taf
period as well. However, there is not yet enough confidence in the
timing/coverage of any shower/TS activity to put anything more than
VCSH in the tafs at this time. Although winds are expected to remain
mainly on the light side (with normal diurnal patterns) through the
taf period, there is a remote possibility that stronger outflow
winds from thunderstorms could briefly affect one or more of the taf
sites, especially during the afternoon/evening hours on Monday.
However, confidence is still far too low at this time to put any
outflow wind shifts in the tafs at this time.
Aviation discussion not updated for amended TAFs.
&&
.FIRE WEATHER...
Wednesday through Sunday...
High pressure redeveloping over the Desert Southwest will bring dry
conditions and well-above normal temperatures to the region on
Wednesday and Thursday. Another weather system brushes the Desert
Southwest late Thursday through Friday for an increase in humidities
and a slight chance of showers -mainly for southeast California and
southwest AZ. Warmer and drier weather is expected to return for
next Sunday. No strong winds are anticipated through the forecast
period. Minimum humidities stay at or above 20% on the lower deserts
for the most part and overnight recovery remains at least good.
&&
.SPOTTER INFORMATION STATEMENT...
Spotters should follow standard reporting procedures.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...None.
CA...None.
&&
$$
Visit us on Facebook...Twitter...and at weather.gov/phoenix
DISCUSSION...Hirsch
PREVIOUS DISCUSSION...CB
AVIATION...Percha
FIRE WEATHER...Percha
Area Forecast Discussion
National Weather Service Las Vegas NV
235 PM PDT SUN OCT 23 2016
.SYNOPSIS...A Pacific storm system will impact the region tonight
through Monday. This will bring increased cloudiness as well as
chances for rain and isolated thunderstorms. More tranquil weather
is expected during the middle of next week before another series of
storms takes aim at the region late in the week through next weekend.
&&
.SHORT TERM...Through Wednesday Night
As for our current products. Based on latest observations and
guidance having a hard time justifying the Wind Advisory so am going
to cancel that product with the afternoon issuance. It does look
breezy to locally windy this afternoon and Monday in parts of Nye,
Esmeralda and Lincoln Counties but not widespread enough for
headlines.
So far more bark than bite in regards to rainfall. Lots of mid/high
level moisture streaming into the Mojave Desert/Southern Great Basin
but little in the way of dynamics or instability to help generate
any more than virga or probably just a light rain shower at the
higher elevations.
As the air mass continues to undergo moistening from the mid-levels
down to the surface tonight stronger dynamics should start to come
into play as jet noses into Southern California placing much of the
Mojave Desert and southern Nevada under the left front exit region.
Some discrepancy between the operational models and HRRR on exactly
where north/south lines of showers/embedded thunderstorms develop.
The operational models remain consistent developing a line between
the Morongo Valley-Spring Mountains-Caliente. Meanwhile, the HRRR is
further west between Ridgecrest-Beatty-Ely. In the end, both
solutions may turn out correct so did not much change to inherited
POP grids which paint the highest POPs in a corridor between Las
Vegas and Beatty tonight/Monday morning. By Monday afternoon the
lines should start dissipating with showers/thunderstorms becoming
more scattered in coverage under slightly more unstable air mass.
Any residual showers/thunderstorms will come to an end Monday night
as dry/more stable air mass develops under building ridge of high
pressure. High pressure stays in control of our weather regime
Tuesday and Wednesday.
.LONG TERM...Thursday through Sunday.
Southwest flow over the area with high pressure to the east and
troughing to the west on Thursday with extended models in agreement.
However, as with previous model runs differences really start to
show up Friday through the weekend. The ECMWF continues to be the
much faster and more progressive model compared to the slower GFS
and Canadian runs. By Thursday afternoon the ECMWF already has
precipitation reaching the southern Sierra while the other models
don`t bring in it until Friday morning. The one thing that the
models basically agree on is the placement of the main rain band
which stretches from far western San Bernardino County up through
Inyo and eventually across Lincoln County while leaving Clark,
eastern San Bernardino, and Mohave Counties generally dry except for
some light scattered showers. Went ahead and kept the current
rainfall timing alone in the grids due to the continued uncertainty,
but upped the pops for Inyo and Nye Counties with likely in the
higher terrain of Inyo. The southwest flow into the Sierra should
help limit how much rainshadowing occurs with a good possibility of
a decent rain event for Inyo County. Although the timing is off on
the models it looks like much of the precipitation will be out of
the area by Saturday as high pressure quickly reestablishes itself
over the area. This would bring a quicker warming trend back to the
area Saturday and Sunday. Even on Friday with the thicker clouds,
most areas will continue to see slightly above normal temperatures.
&&
.AVIATION...For McCarran...Light winds are expected through the
evening. However, with some of the showers and potential
thunderstorms that will move toward the area its possible that some
stronger winds associated with these storms will move into the
valley. The best window for this happening will be between 02z-08z.
Showers will also be possible in the valley, but thunderstorms look
to remain west and northwest. Cigs down to 8-10K feet overnight.
Scattered showers possible through midday Monday with cigs around
10k feet and south winds increasing to around 10-20kts in the
afternoon.
For the rest of southern Nevada...northwest Arizona...and southeast
California...Scattered showers and thunderstorms expected overnight
and Monday with a drying trend from west to east Monday afternoon.
Cigs around 8-10k feet over most areas. Gusty winds will continue
this evening for Inyo, Esmeralda, and central Nye Counties with
south winds over most areas Monday 10-20kts.
&&
.FIRE WEATHER...Expanded the Red Flag Warning to include Fire Zone
460 as local red flag conditions are being met. Winds will diminish
tonight only to increase again Monday. Humidity levels will be
higher on Monday so there is not threat of Red Flag conditions being
met. Drier and more stable weather is in the forecast Tuesday
through Thursday with unsettled weather returning late in the week
and next weekend.
&&
.SPOTTER INFORMATION STATEMENT...Chances for rain and perhaps
isolated storms will increase on Sunday and Monday. Spotters should
report significant weather according to standard operating
procedures.
&&
$$
Short Term/Fire Weather...Pierce
Long Term/Aviation...Gorelow
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