Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 03/08/17
Area Forecast Discussion
National Weather Service Gaylord MI
1032 PM EST Tue Mar 7 2017
.UPDATE...
Issued at 1023 PM EST Tue Mar 7 2017
Not much new to report at this hour. Incredible surface pressure
gradient between 965 mb blizzard across northwest Ontario and 1026
mb high pressure over central Plains remains. Luckily winds have
largely decoupled across most spots. Winds will ramp up once again
after daybreak as we get into better mixing. Current wind advisory
looks fine, though a few isolated gusts to high wind warning
criteria (58 mph) appear possible, especially near the Lake
Michigan shoreline. As far as tonight goes, still breezy or
actually brisk now with slow cold advection continuing. Very steep
lapse rates overnight moving in from the west may spark a few rain
or snow showers. APX 08/00z sounding showed very dry air to
overcome at mid/low levels with a precipitable water of only 0.15
of an inch. Even so, the RAP along with other hires model
guidance even prints out a few hundredths of an inch qpf which may
be hard to do. Current 30 pops look good for now and will monitor
to see what develops.
&&
.NEAR TERM...(Tonight and Wednesday)
Issued at 308 PM EST Tue Mar 7 2017
...Very gusty winds bring in a progressively colder airmass...
High Impact Weather Potential: Very gusty winds through Wednesday
could result in additional tree damage and power outages.
Pattern Synopsis/Forecast: Very gusty southwest winds found across
the Great Lakes, a product of a very tight pressure gradient between
still deepening low pressure over western Ontario (nearing 970mbs)
and broader high pressure centered over the Southern Plains. Cold
front and attendant shower threat now well removed to our east, with
overhead dry slot actually bringing quite a bit of sunshine to much
of northern lower Michigan. Cold air advection now fully
estabilished, with much of the area falling through the 40s. Next
surge of even more intense cold air advection rotating southeast
across the northern plains, with sub -30c h5 temperatures helping
drive an increasingly agitated, but elevated, cu field back across
South Dakota. This surge of cold anomalies will race east, entering
our area early this evening. This sets the stage for a much colder
and very windy Wednesday, when another round of wind headlines will
be needed.
Primary forecast concerns: High impact wind concerns through the
Wednesday. Addressing rain and snow shower potential tonight and
lake effect snow concerns Wednesday.
Details: First order of business tonight remains the winds.
Widespread wind gusts in excess of 40 mph through the remainder of
this afternoon, strongest across eastern upper Michigan. Winds are
expected to subside some tonight, but gusty winds will continue. As
mentioned, corridor of very cold H5 temperatures slides overhead
quickly this evening, helping drive H7-H5 lapse rates to above 8c.
Not a ton of moisture for sure, but nearly all guidance goes upscale
with that upstream cu field, kicking off band of showers in the
processes, and drives such through our area this evening. Given
satellite trends, hard to totally discount this idea. Will introduce
this potential, and with cooling low level thermal profiles, will
also introduce a rain/snow mix with time. Definitely not looking
like anything significant.
Deep mixing depth via continued cold air advection helps tap into
another robust low level jet Wednesday, bringing another round of
very gusty west winds. Most intense portion of low level jet passes
by just to our south. Still, bufkit soundings show good mixing up
through 50 knot jet, bringing a good portion of this momentum down
to the surface. Could easily see widespread wind gusts in excess of
40 mph, with more isolated gusts of 45 mph to 50 mph. This makes for
a complicated headline scenario across northern lower (earlier
issued wind advisory for eastern upper already goes through
Wednesday). Per collaboration with surrounding offices, will go
ahead and expire current wind advisory for northwest lower upon
forecast release this afternoon, issuing an area wide wind advisory
during the day Wednesday.
Secondary concern Wednesday centers around development of lake
effect snow showers. Most persistent activity expected in the snow
belts of eastern upper where deeper moisture and simple longer
upstream fetch reside. Could see an inch or two north of M-28 by
evening. Airmass is a much drier one south of the bridge, with
strong and elongated inverted-v signature noted on forecast
soundings. Simple breadth of caa will kick off some lake clouds and
a few flurries/very light snow showers, with only a dusting of snow
expected.
&&
.SHORT TERM...(Wednesday night through Friday)
Issued at 308 PM EST Tue Mar 7 2017
High Impact Weather Potential...Minimal.
Pattern Synopsis/Forecast...Winter will make a return appearance
to northern Michigan for the end of the week, at least with
regard to temperatures. Several reinforcing shots of cold air
associated with weak shortwave/fropa`s Wednesday night through
Friday. Extreme amounts of overlake instability developing by
Thursday into Friday, with delta T`s near 30 DegC. This would
normally evoke a strong lake effect response. But in this case,
not so much. The main limiting factor throughout this time frame
is moisture. With PWAT`s around 0.25 inches and only brief bouts
of slightly deeper moisture, robust lake effect will be difficult
to achieve. The exception to this will be north of M-28 in eastern
upper Michigan, where slightly deeper moisture will reside and
extend through the DGZ, resulting in more persistent snow shower
activity and likely at least minor snow accumulations. Over
northern lower, not much. Moisture just not deep enough and not
extending through the DGZ. Some of the coldest air of the year
plunges into the northern lakes for Thursday night and Friday,
with H8 temperatures of -22 to -24 degC. Most areas only in the
teens for high temperatures on Friday, with some areas possibly
remaining in the single digits over eastern upper. Quite a change
from the temperatures we have experienced recently.
Primary Forecast Concerns...Nothing significant. Will have to watch
the lake effect activity to see if we can generate more accumulation
than currently anticipated over parts of eastern upper. Hard to see
this becoming anything significant but several inches of snow
possible up toward Whitefish Bay along with breezy conditions, so
some areas of blowing snow a possibility. Temperatures are the
other thing to watch, as low temperatures below zero likely in some
areas toward the end of the week - which might be some of the
coldest temperatures of the winter in some areas.
.LONG TERM...(Friday night through Tuesday)
Issued at 308 PM EST Tue Mar 7 2017
Colder air will continue to filter into the forecast area as the
Great Lakes remains on the eastern periphery of a strong high
pressure centered near southern Alberta. Light lake effect snows
will be possible over eastern upper through Sunday as sufficient
moisture lingers along with the cold 850mb temperatures and
northwesterly wind regime. The next chance for widespread snow
will be Sunday night through Monday night as a developing low
pressure system over the central Great Plains tracks through the
southern Great Lakes. At this time this system appears to have the
potential to accumulate 2-4 inches of snow. An area of high
pressure will then move over the forecast area providing a brief
period of precipitation-free weather through Tuesday afternoon
before models hint at another system moving through the forecast
area Tuesday night into Wednesday.
Temperatures will remain in the mid 20s to low 30s throughout the
forecast period, while lows will be cold, in the single digits above
zero to low teens.
&&
.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 628 PM EST Tue Mar 7 2017
...Very gusty winds, especially Wednesday...
Winds are not nearly as gusty as they were earlier today, though
they will still be a little gusty tonight. The lower wind speeds
will lead to low level wind shear at all taf sites through early
Wednesday. Surface winds will ramp back up again Wednesday. There
could be a few passing rain or snow showers later tonight but
otherwise dry air should win out with no cig/vsby related issues
expected.
&&
.MARINE...
Issued at 308 PM EST Tue Mar 7 2017
Gale producing wind gusts expected across all nearshore
waters through Wednesday. Strongest core of southwest winds expected
through this afternoon, with another surge of very gusty west winds
expected on Wednesday.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...WIND ADVISORY from 7 AM to 7 PM EST Wednesday for MIZ016>036-041-
042.
WIND ADVISORY until 7 PM EST Wednesday for MIZ008-015.
LH...GALE WARNING until 7 PM EST Wednesday for LHZ345>349.
LM...GALE WARNING until 7 PM EST Wednesday for LMZ323-341-342-344>346.
LS...NONE.
&&
$$
UPDATE...AJS
NEAR TERM...MSB
SHORT TERM...JRK
LONG TERM...TJL
AVIATION...AJS
MARINE...MSB
Area Forecast Discussion...Updated
National Weather Service Billings MT
859 PM MST Tue Mar 7 2017
.UPDATE...
Winds have decreased across most of the area and this handled
well in going forecast. Temperatures have dropped into the 20s to
around 30 degrees with limited cloud cover. Clouds were increasing
over the west and this should help to slow down the descent. That
being said, did drop forecast lows a couple of degrees, more in
line with MAV guidance, with low dewpoints hover over southern
Montana and northern Wyoming. Current PoPs look in good shape.
Warm advection pattern producing the clouds over the west and
this, along with the tail of a jet, should produce areas of light
snow over parts of the western and central zones. Emphasis seems
to be over the northwest zones and latest HRRR runs support that.
Will leave PoPs alone as the projection of snow chances increasing
as the night wears looks looks good. TWH
&&
.SHORT TERM...valid for Wed and Thu...
Blustery day as strong west winds rocked the region. Gusts 45 to
50 mph were common in many locations. We do expect the winds to
quickly back off after sunset this evening from west to east as
the stronger 700 mb wind speeds exit the area and low level lapse
rates decrease. We also have some popcorn like convection showing
up on radar this afternoon. Low levels are quite dry (single
digit dewpoint at Billings), so most of this is virga. This should
diminish after sunset as well.
For tonight, a weak shallow surge of cold air into the CWA which
sets up some overrunning will combine with a Pacific impulse
moving over the region. The focus of lift then centers around our
northwest zones from Harlowton to Roundup. This area may pick up
an inch or two of snowfall overnight. We could even see some light
brief precipitation as far south as Billings by morning, but
probably not measurable this far south.
The main forecast problem for this shift though is the
significant discrepancy between the ECMWF and GFS concerning the
placement of QPF for Wednesday night through Friday. This is
largely being determined by how far the Canadian air mass to the
north slides south, and the depth of the cold air as well. The
ECMWF keeps the main pocket of precipitation over the east central
section of the state such as Lewistown. The GFS and NAM are
suggesting a deep portion of this cold air slipping down at least
as far south as Yellowstone County. While the ECMWF keeps the
deepest colder air further north through most of this event. While
we believe the sharply colder air may be dense enough to slip
south well into our CWA with little help, we are concerned about
the strong westerly flow in the mid levels limiting its southern
intrusion. We will bank on the deepest cold air (and thus best
overrunning) to stay a bit further north than what the GFS/NAM
suggest at this time. We have trended our snowfall totals and QPF
somewhat further north than the GFS guidance which limits
snowfall in the Beartooth foothills and place the heaviest from
Billings northward and northwest. At any rate, confidence in how
this turns out is low, and we may need to deal with this systems
evolution on the go or in the eleventh hour.
That said, we are coming up with totals over six inches from
Billings northward. This seems reasonable based on overrunning and
associated jet dynamics involved. We have decided to issue a
Winter Storm Watch for these locations Wednesday night through
Friday. Please see website for potential snowfall totals. By
Friday night the main precip threat should end as the jet dynamics
push to the Dakotas and upslope and moisture decrease. BT
.LONG TERM...valid for Fri...Sat...Sun...Mon...Tue...
Weather pattern will remain active through the weekend into the
first part of next week. Location of Canadian frontal boundary
will be a problematic feature with regard to both temperatures and
snow potential across our cwa.
Snow will continue Friday, shifting east over time as the cold air
shallows along our western foothills, eventually ending with
shortwave passage Friday night. Greatest snow amounts during this
time should continue to be over the mountains and away from the
foothills, per downslope component of 40-50 kt westerly flow at
700mb. Friday-Friday night may also offer the greatest potential
for snowfall across our eastern zones. Though model spread in sfc
temps remains high, pressure tendencies suggest the colder
Canadian airmass keep easterly winds and temps well below normal
across the plains on Friday, so have lowered expected highs a few
degrees.
Temperature forecast will be difficult Saturday through next
Monday as Canadian front remains nearby, with occasional cold
surges offset by brief periods of downsloping off the foothills,
courtesy of a couple Pacific shortwaves. Will stay near a model
average for now, with temps likely to be above normal along the
foothills and below normal in our east. Lower elevation snow cover
could help to keep lee side surface pressures elevated, so a
leaning on the cold side of the model spread seems prudent at this
time.
A series of fast-moving shortwaves will keep the chance of snow
showers going from Saturday night through Monday, again keeping in
mind that the location of the surface boundary will be important.
It does appear that the ridge axis will shift east and allow for a
greater chance of warmer downslope winds spreading east across our
cwa by Tuesday. With this in mind have raised temps to above
normal with highs into the 50s by next Tuesday. JKL
&&
.AVIATION...
Gusty NW surface winds will continue to decrease this evening.
Gusty SW winds in KLVM will decrease to light easterly around 06Z,
then increase again from the SW early Wed. morning. Expect LLWS
over KLVM when the winds become light. Chances for snow will
increase over the area from W to E overnight. On Wed. morning,
chances for snow will be confined to KLVM to KBIL to KMLS N. The
snow will be accompanied by MVFR/IFR conditions through Wednesday.
Chances for rain and snow showers will occur across the entire
area Wed. afternoon. Expect LLWS over KBIL on Wednesday.
Widespread mountain obscurations will affect the Beartooths,
Absarokas and Crazys through Wed., while localized obscurations
will affect the NE Bighorns. Arthur
&&
.PRELIMINARY POINT TEMP/POPS...
Wed Thu Fri Sat Sun Mon Tue
-----------------------------------------------------------
BIL 023/048 026/033 017/031 020/033 020/037 021/041 030/054
43/W 76/S 75/S 31/B 22/W 33/J 22/W
LVM 028/049 031/041 027/046 027/043 030/051 029/051 036/056
34/W 66/O 66/O 21/B 33/W 33/W 22/W
HDN 022/051 025/035 018/031 015/031 016/037 018/041 026/054
24/W 66/S 65/S 31/B 22/W 33/J 22/W
MLS 014/037 021/027 014/027 012/023 010/029 011/034 023/048
13/J 24/S 77/S 41/E 43/J 32/J 22/W
4BQ 019/047 025/036 017/029 015/033 018/039 017/041 027/055
11/E 44/S 66/S 51/B 22/W 42/J 22/W
BHK 010/035 018/025 008/020 010/022 012/028 010/031 020/045
01/E 23/S 57/S 52/J 44/J 32/J 22/W
SHR 018/050 027/041 023/042 023/045 025/051 024/051 029/058
11/B 33/O 33/S 51/B 12/W 32/W 22/W
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...Winter Storm Watch in effect from Wednesday evening through
Friday afternoon FOR ZONES 28>31-34-35-41-42-57-63.
WY...None.
&&
$$
weather.gov/billings
Area Forecast Discussion
National Weather Service State College PA
1051 PM EST Tue Mar 7 2017
.SYNOPSIS...
A cold front will push east across the state tonight and early
Wednesday. Windy but relatively mild conditions with a decent
amount of sunshine will follow the front for Wednesday. A weak
area of low pressure will likely track south of PA on Friday.
This system will likely bring between 1 and 3 inches of snow to
the area from late Thursday Night into Friday.
Another weak low moving south of PA on Sunday may bring more
light snow to the area on Sunday, mainly across the southern
part of the state.
A third and more complex area of low pressure may target the
area Monday Night into Tuesday with additional light snow.
Temperatures will trend below normal by Friday.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
Radar loop at 0330Z showing a distinct line of showers along
cold front pushing through the northwest mountains, with a
trailing area of light rain associated with upward motion
beneath jet streak entrance region.
Model timing of front ranges from 04Z-06Z across the central
mountains, to between 08Z-09Z over Lancaster County. However,
expect post fropa showers to continue for a couple hours in
region of favorable jet streak dynamics. By dawn, expect the
last of the showers to have ended, as cold front passes well
east of the area and jet streak forcing lifts northeast of the
state.
Based on latest model soundings, have added the chance of snow
wet snow mixing with the rain before ending across the high
terrain of the north, but no accums expected. Temps by dawn
expected to range from the mid 30s over the Allegheny Plateau,
to the mid 40s over the southeast counties.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH 6 PM WEDNESDAY/...
Based on the HRRR timing and the NCEP NAM/GFS, all the
significant shower and rain activity should be to our east on
Wednesday. The HRRR shows the lower dew points into the lower
Susquehanna Valley around 8 AM.
After a mostly sunny start to the day across the entire region,
expect increasing clouds and widely sct showers to develop
across northern Pa associated with steepening lapse rates ahead
of a weak secondary cold front. Increasing flow aloft will begin
mixing to the surface as boundary layer warms/deepens by late
morning. Although much of the area will be rather windy by
afternoon, Bufkit soundings continue to indicate the strongest
gusts of around 40kts will be across the western half of the
state. A wind advisory remains up for the western portion of our
county warning air from mid-morning into the evening.
Note the strongest winds will most likely be confined to near
the ridge tops and especially down the eastern slopes of the
higher terrain.
The air mass behind tonight`s cold front will be far from
chilly for early March. 850 temps between 0C and -2C along with
deep mixing should translate to highs Wednesday from the upper
40s over the northwest mountains, to around 60F across the Lower
Susq Valley.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/...
Some light snow indicated by the models and WPC after 06Z
Friday, as a weak low tracks east from the plains. Went close
to the current fcst. Heaviest snow most likely will fall across
the Laurel Highlands. Hard part of the fcst is to figure out
why models have nothing to the west of PA before 00Z Friday.
Increasing confidence in dry/chilly weather later Friday into
Saturday, when all med range guidance shows surface ridge
building southeast from the Grt Lks. There could be some upslope
snow showers early across the Laurel Highlands, but the flow is
rather northerly. A 1048 MB high is fcst to build into the
northern plains, with abnormally cold air this weekend.
Another weak low moving south of the region on Sunday may bring
some light snow to the area (mainly southern PA) early on
Sunday. 12Z EC and some other models show almost no snow for PA
now. I did cut POPS down some, but did not want to flip, flop
the fcst.
Still a third system possible with more light snow on Tuesday.
This system will likely be followed by another large high with
abnormally cold air.
&&
.AVIATION /04Z WEDNESDAY THROUGH SUNDAY/...
This evening, one batch of steadier rain can be found across the
Middle and Lower Susquehanna Valley region, with a second area
of showers poised to move into far northwest portions of Central
Pennsylvania associated with the cold front.
Mix of variable, and sometimes rapidly changing conditions
across the region...with VFR to IFR conditions being reported.
In general...look for restrictions to prevail most of the
evening into the overnight, until the passage of the cold front.
The air behind the front is rather dry so improvement in
conditions expected to occur rapidly after the frontal passage.
Frontal timing looks to be 02-04 UTC in the northwest...06-08
UTC in central areas...and 09-12 UTC in the southeast.
VFR conditions Wednesday behind the front, but winds will be
brisk and gusty. Could see frequent gusts 28-32 knots by
16-18z...with the higher gusts at the western airfields.
Outlook...
Wed...Mainly VFR. Isolated SHRA possible in the Northwest.
Thu...Mainly VFR. Though possible MVFR moving in overnight.
Fri...Possible MVFR and IFR with snow in central and southern
areas.
Sat...Mainly VFR.
Sun...Chance of some light snow and restrictions.
&&
.FIRE WEATHER...
It will be windy on Wednesday and RH levels will fall.
However, rainfall last night and today will result in
things starting off damp. Thus not seeing an elevated
fire risk at this point.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
Wind Advisory from 10 AM to 7 PM EST Wednesday for PAZ004-005-
010-017-024-025-033-034.
&&
$$
SYNOPSIS...Fitzgerald/Lambert
NEAR TERM...Fitzgerald
SHORT TERM...Grumm/Fitzgerald
LONG TERM...Lambert/Martin
AVIATION...Jung
FIRE WEATHER...
Area Forecast Discussion
National Weather Service Duluth MN
858 PM CST Tue Mar 7 2017
.UPDATE...
Issued at 858 PM CST Tue Mar 7 2017
We extended the Wind Advisory for northwest Wisconsin, excluding
Price County, and Pine County in Minnesota through midnight and
the rest of the Wind Advisory through 9 AM. The frequency of the
higher gusts may diminish but we still expect some into advisory
thresholds.
UPDATE Issued at 709 PM CST Tue Mar 7 2017
Deep low pressure located well north in northern Ontario along
with continued cold air advection has led to strong winds across
the Northland into this evening. The cold air and cyclonic flow
with embedded shortwaves was also causing snow showers and they
will continue tonight. The wind has diminished in spots this
evening but still remained high. Several observations continued
with sustained winds around 30 MPH with gusts 40 MPH to 50 MPH.
Forecast soundings show a gradual decrease in the depth of the
mixed layer tonight as would be expected, but the RAP does show
mixing to a bit higher than 850MB through Wednesday morning. We
monitor trends in the wind over the next hour or so but may have
to extend the Wind Advisory for portions of the Northland.
&&
.SHORT TERM...(This evening through Wednesday)
Issued at 338 PM CST Tue Mar 7 2017
A gradual downtrend in wind magnitudes are expected for this
evening before ramping up again during the day tomorrow. Through
this afternoon, most places have been gusting between 35 and 45
knots, with some gusts up to 50 knots observed over the Duluth
area. Model soundings are indicating gusts will continue through
the evening before boundary layer mixing weakens a bit overnight.
Winds will still gust between 25 to 35 knots, which is below the
Wind Advisory criteria. 850 mb level winds progged in the synoptic
models will gradually weaken overnight, but could still remain
strong through the evening, although the wind threat is a bit more
marginal. Thus, extended the current Wind Advisory through 03z
tonight. Will let the subsequent shifts make the decision
regarding to drop the Wind Advisory early. Winds are expected to
continue to be gusty Wednesday, but not as strong as was observed
today as the stronger low-level jet flow will move off to the
south and weaken. Winds could still gust between 25 to 35 knots
during the day Wednesday.
The Northland is expected to remain under the cyclonic flow from a
potent sfc low pressure system that will translate across
northwest Ontario and northeast towards Hudson Bay. The associated
mid-level shortwave trough is expected to eject a couple of
embedded positive vorticity advection lobes through the region,
keeping some modest support for a chance of snow showers,
especially across the northern portions of the forecast area.
Coupled with the gusty westerly winds tonight and Wednesday
morning, there is the potential of some blowing snow, mainly along
the Iron Range and points north. Chances of snow showers will
come to an end Wednesday afternoon as the better mid-level support
advances to the east. Temperatures will actually be below seasonal
averages tonight and Wednesday, thanks to enhanced cold air
advection as the system departs. Lows tonight look to drop into
the single digits north and the upper teens southeast. Highs
Wednesday will range from the mid teens north to the upper 20s and
near 30 south.
.LONG TERM...(Wednesday night through Tuesday)
Issued at 312 PM CST Tue Mar 7 2017
The upper level low will continue to move off to the north and east
Wednesday night, but the upper level flow will continue out of the
northwest for the end of the week and into the weekend. Some
scattered snow showers will be possible at times along the south
shore of Lake Superior, but overall, winds look a bit too westerly
for any appreciable snow accumulation. Otherwise, it is shaping up
to be a dry and relatively cool period from Wednesday night through
Saturday night. The next real chance of precipitation should arrive
on Sunday, and move out of the area on Monday. The GFS brings the
most prolonged period of light snow, with the ECMWF indicating a
quick shot of light snow during that time. Temperatures will be
below normal for much of the long term period with highs in the
teens and 20s from Thursday into Saturday with some moderation late
in the weekend and early in the upcoming work week.
&&
.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 544 PM CST Tue Mar 7 2017
Very strong winds continued across most of the Northland this
evening and they will only slowly decrease tonight but remain
strong into Wednesday. Snow showers will also occur and will
increase in coverage for a time this evening before diminishing
late. Mainly VFR ceilings will occur but some drop to MVFR is
expected. The visibility in the snow showers will drop to IFR at
times or even LIFR.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 12 20 6 24 / 50 10 0 0
INL 5 16 -2 14 / 60 30 0 0
BRD 13 27 10 27 / 50 10 0 0
HYR 17 27 10 29 / 30 20 0 0
ASX 17 24 12 28 / 40 30 10 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
WI...Wind Advisory until midnight CST tonight for WIZ001>004-006>008.
Wind Advisory until 9 PM CST this evening for WIZ009.
MN...Wind Advisory until midnight CST tonight for MNZ038.
Wind Advisory until 9 AM CST Wednesday for MNZ018>021-025-026-
033>037.
LS...None.
&&
$$
UPDATE...Melde
SHORT TERM...JTS
LONG TERM...DAP
AVIATION...Melde
Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
917 PM EST Tue Mar 7 2017
.SYNOPSIS...
A moist cold front will cross the region through the morning
Wednesday. Dry high pressure will then build in and persist through
Thursday before a weak area of low pressure quickly passes by on
Friday. A stronger low pressure system will cross the area late
Saturday into Sunday, bringing cooler temperatures and beneficial
rainfall.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
As of 910 PM: Turns out virtually all guidance was far too slow
in moving the prefrontal rainfall through the area. What was left
of the primary rain shield is now a showery area over the I-85
corridor and vicinity. This is moving east at about 40 mph, and
there should be a lull in activity before a narrow band arrives
within the frontal convergence zone (as currently seen along the
upper Ohio River and as far south as eastern KY). Since guidance
is universally handling the timing of the first wave poorly, the
grids basically have been drawn by hand. Followed the HRRR on the
later band, as it seems to be on track with that feature. Temps
are being adjusted per RAP, which will keep values warmer until
they fall fairly rapidly late in the night.
Behind the front on Wednesday, little post fropa cooling is expected
as the replacement airmass originated over the southern/central
Rockies. Thus, although dewpoints will fall off by nearly 20
degrees, afternoon highs Wed will be fairly similar to those Tue
given abundant insolation, especially over the Piedmont where
downsloping flow will prevail. All said, Wednesday looks to be a
fairly nice day across the region with modest nwly 15-20mph gusting
possible outside of mtns, gusting in the 25-35mph range over the
high terrain. Given the drier air advecting into the region as
mentioned above, RH levels look to fall to critical levels across
the vast majority of the fcst area during peak mixing on Wednesday.
Depending on the eventual placement/amounts of rainfall associated
with the fropa tonight, fire danger statements may be needed.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
As of 210 PM Tuesday, a fast quasi-zonal/low amplitude upper air
pattern will be in place across much of the eastern half of the
Conus during the short term, with dry (but warm) surface high
pressure dominating early in the period. Max temps will remain well
(i.e., more than 10 degrees) above climo through the period, while
the dry air/good radiational cooling conditions should allow
Wednesday night`s min temps to fall close to climo.
A strong short wave trough digging into the Northeast/upper
Mid-Atlantic late in the period will send another cold front toward
the western Carolinas and northeast Georgia on Friday. A consensus
of operational model guidance indicates moisture will be limited
primarily to the lower levels, while even that may dry up as the
front pushes east of the mtns within a westerly low level flow
regime. Pops will therefore be mainly limited to the mtns, and even
there, only 30-40 percent chances appear warranted attm.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
As of 2pm Tuesday: For the extended forecast, the main forecast
event will be the passage of an upper trough/frontal system Saturday
night and Sunday. This event is expected to bring a half inch to
three quarters of an inch of rain to most locations, with some snow
at the highest elevations in the mountains. The cold spot in the
forecast will be behind the front Monday morning with freezing
temperatures at higher elevations, and frost possible in the
Piedmont.
A brief period of northeasterly surface wedge flow is possible on
Saturday with a small surface high setting-up over eastern VA, but
this will be quickly disrupted by the next system, though cold
surface wedge in place will preclude any sort of deep convection
with that system.
EC and GFS models are fairly consistent in the handling of the
Saturday/Sunday system with precipitation moving across the TN/NC
line Saturday evening and exiting the area eastward by Sunday
afternoon. EC is somewhat heavier with precip., though a model
blend will be the best guess at this point. Temperatures Sunday
morning over much of western North Carolina will be cold enough for
some snow mixed with rain, but accumulations of up to a few inches
are only expected at the highest elevations in the mountains. A
fairly strong surface low develops off the Carolina coast as the
upper low moves east of the mountains, which will strengthen the
system as it exits the area and bring some stronger easterly winds
to Piedmont areas.
Northwesterly flow aloft continues behind the system passage on
Monday and Tuesday with some slight chance for precipitation from an
embedded shortwave, but dewpoints and moisture are kept dry with
persistent northwesterly 850mb flow. GFS tries to develop a trough
with precip. into western parts of the CWA early on Tuesday, but
this is ill-defined at this point, and is a detail completely
lacking in the EC model.
&&
.AVIATION /02Z WEDNESDAY THROUGH SUNDAY/...
At KCLT and Elsewhere: A cold front is set to cross the area during
the early morning hours. Preceding this front, patches of DZ and
SHRA will move across all sites in some fashion, before a more
contiguous band of RA arrives. Some guidance indicates a third
narrow band will develop in the convergence zone right along the
front later tonight. Guidance and upstream obs suggest the greatest
chance of prolonged restrictions will develop with that "middle"
band and persist for some time after it moves past each affected
terminal. While guidance supports mainly MVFR, obs suggest spotty
IFR cigs/vsby will develop therein. IFR could also return if the
later band develops. Lifting/scattering back to VFR, along with
the post-frontal shift to NW winds, is expected in the wee hours
at KAVL/KHKY and just before sunrise at the Piedmont sites. The
southwesterly flow overnight will bring some occasional minor gusts,
with more brisk gusts occurring under CAA regime during the day
(particularly at KAVL).
Outlook: Dry high pressure persists Wed night and Thursday. Another
cold front will likely move thru the area on Friday, however it
appears to be mostly dry. A passing low pressure system late in
the weekend might bring some precipitation to the region, and if
so would likely cause restrictions for at least some of the area.
Confidence Table...
02-08Z 08-14Z 14-20Z 20-00Z
KCLT High 97% High 89% High 100% High 100%
KGSP Med 76% High 90% High 100% High 100%
KAVL Med 70% High 91% High 100% High 100%
KHKY High 87% High 93% High 100% High 100%
KGMU High 83% High 87% High 100% High 100%
KAND High 95% High 80% High 100% High 100%
The percentage reflects the number of guidance members agreeing
with the scheduled TAF issuance flight rule category. Complete hourly
experimental aviation forecast consistency tables and ensemble forecasts
are available at the following link:
www.weather.gov/gsp/aviation
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...None.
NC...None.
SC...None.
&&
$$
SYNOPSIS...SBK
NEAR TERM...CDG/Wimberley
SHORT TERM...JDL
LONG TERM...WJM
AVIATION...Wimberley
Area Forecast Discussion
National Weather Service Honolulu HI
350 PM HST Tue Mar 7 2017
.SYNOPSIS...
Unsettled weather is in store for portions of the state into
Thursday. A strong upper level trough passing over the region will
create the potential for heavy showers and strong thunderstorms
during this time, especially along a stalled band of low level
moisture currently stretched over and near Maui County and
northern Big Island. A weak ridge will settle near the state on
Friday, bringing light winds and humid conditions for the weekend.
&&
.DISCUSSION...
A complex pattern remains in place this afternoon, with heavy
showers and thunderstorms favoring the eastern half of the island
chain. A band of low level moisture and convergence, the remnant
of an old front, has been stalled over Maui County and northern
Big Island all day, with precipitable water (PW) values hovering
around 1.25 to 1.6 inches. Meanwhile, a strong mid to upper level
trough centered about 300 miles northwest of Kauai continues to
dig toward the state. This feature is already producing enough
instability to trigger isolated heavy showers and thunderstorms
along the low level moisture band. The mid to upper level trough
is also driving a weak surface cold front that is being obscured
by a band of layered high clouds just northwest of Kauai.
Sandwiched between these features, a somewhat dry, northerly low
level flow with dew points in the lower 60s deg F range is fading
over Oahu.
The atmosphere will become increasingly unstable tonight and
Wednesday, upping chances for heavy showers and possibly strong
thunderstorms. Although the details remain elusive, the GFS and
ECMWF models are both showing a roughly 100 kt jet stream setting
up over the islands late tonight and Wednesday as the upper level
trough digs over the region. Temps at 500 mb will fall to the -13
to -16 C range, which is very cold by Hawaii standards. As a
result, CAPE values increase, especially along the stalled low
level moisture boundary, while 0-6 km bulk shear values remain
elevated at 35 kt or more. This instability will set the stage for
strong to possibly severe thunderstorms as early as late tonight,
but chances are higher during the day on Wednesday as CAPE is
maximized. The greatest threat will remain along the low level
moisture boundary centered over Maui County and northern Big
Island. We will also have to monitor the dissipating front moving
over Kauai tonight, since the HRRR model is suggesting that
thunderstorms could develop due to orographic forcing late this
evening.
Though the threat is marginal, mainly due to the isolated nature
of the potential heavy showers, we felt that a Flash Flood Watch
is appropriate, since there will be a prolonged period of heavy
shower potential and the possibility of anchored showers under
light winds. The Flash Flood Watch has been issued for all
islands, with the greatest flood potential remaining along the low
level moisture boundary.
By Wednesday night, the GFS and ECMWF show deeper moisture
surging northward over the state, maintaining the threat for
flash flooding. On Thursday, the upper level trough will gradually
weaken overhead, but conditions will remain rather moist and
unstable. The Flash Flood Watch currently runs through Wednesday
night but may need to be extended into Thursday.
The flood and thunderstorm threat will diminish on Friday as the
upper level trough weakens and pushes eastward. A weak low level
ridge will build just north of the state, ushering in weak trades.
The ridge will shift over the islands during the weekend,
promoting light winds and humid conditions.
&&
.AVIATION...
For the eastern Hawaiian Islands, moisture from a remnant frontal
boundary between the Big Island and Maui will continue to be the
focus of showers into the evening. At this time, this is
highlighted with VCSH for the nearby terminals at Kona and
Kahului. Thunderstorms with MVFR conditions will remain possible
into the evening for these locations and will continue to monitor
radar trends closely for the possible addition of tempo groups to
highlight heavier showers and thunderstorms for these terminals.
For the western Hawaiian Islands, the next frontal boundary will
move eastward across Kauai this afternoon into the evening and
eastward to Oahu and Maui overnight. This will allow for an
increased chance of showers with thunderstorms with gusty winds
and MVFR conditions possible as the boundary moves through.
AIRMET Sierra for mountain obscurations remains in effect for
windward sections of Maui. As moisture encroaches from the west
with the next frontal boundary, this may be needed for Kauai and
possibly Oahu overnight.
&&
.MARINE...
The west-northwest swell (290-320 deg) currently impacting the
islands and its resulting surf will gradually ease through early
Wednesday.
The latest surface analysis and satellite imagery showed a gale-
force low centered around 1000 nautical miles north-northwest of
the state tracking back toward the south-southeast. The latest ASCAT
pass late this morning still showed an area of gales out of the
northwest associated with this feature focused toward the local
area. This will result in a large reinforcing swell out of a more
northwest direction (330 deg) with expected impact to the Hawaiian
waters Wednesday through early Friday before gradually trending
down into the weekend. The ECMWF-Wave solution still brings this
swell in a bit earlier across the local waters with a peak up to
a couple of feet larger than the WAVEWATCH III. If this larger
solution verifies, surf may near warning levels late Wednesday
through Wednesday night. For now, have issued a High Surf Advisory
for exposed north and west facing shores for Wednesday and
Thursday. Large seas will also be an issue with this swell, so a
Small Craft Advisory will be needed. Seas and surf trend down once
again Friday through the weekend.
Local winds will remain light through the week as another front
approaches and moves into the area through mid-week. Periods of
heavy showers and a few thunderstorms remain in the forecast due
to a combination of this front and a disturbance aloft setting up
over the region.
&&
.HFO WATCHES/WARNINGS/ADVISORIES...
Flash Flood Watch from 6 PM HST this evening through late
Wednesday night for all Hawaii islands.
High Surf Advisory from 10 AM Wednesday to 6 PM HST Thursday for
Niihau-Kauai Windward-Kauai Leeward-Waianae Coast-Oahu North
Shore-Oahu Koolau-Molokai-Maui Windward West-Maui Central Valley-
Windward Haleakala.
Wind Advisory until 6 PM HST Wednesday for Big Island Summits.
&&
$$
Public...Wroe
Marine...TS
Aviation...Woodrum
Area Forecast Discussion
National Weather Service Wilmington NC
958 PM EST Tue Mar 7 2017
.SYNOPSIS...
A cold front will move across the area late tonight with a few
showers possible. High pressure will build in through Saturday
in the wake of this front. Low pressure will bring a chance of
showers late in the weekend.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
As of 10 PM Tuesday...Broken band of light rainshowers
impinging upon the CWA from the NW while a shower or two are
skirting the coast over our eastern fringes. Coverage will
gradually increase but given latest under-whelming depictions
from high-res guidance see no need to increase POPs from present
chance levels. Previous discussion follows:
A warm day will transition to a warm night as SW return flow
around offshore high pressure persists ahead of an approaching
cold front. Gusty S/SW winds have reached 20-25 mph this aftn,
and while gusts will ease tonight, sustained winds will remain
elevated as the gradient pinches ahead of the boundary. This
will keep temps elevated tonight, with mins expected to drop
only to a degree or two either side of 60. At the same time,
southerly flow may try to advect a few showers onshore this
evening, but have capped POP at SCHC for the coastal sections.
A better chance of rain occurs overnight and into the first few
hours of Wednesday, associated with the cold front. High-res
guidance including the HRRR and ARW both suggest precip coverage
will be waning as this front pushes across the region, exiting
offshore early Wednesday morning. Have capped POP at high CHC, with
the highest QPF expected across northern zones. Even there, total
rainfall will only reach around 0.1 inches, with less forecast to
the south. Cold advection behind this feature is weak to non-
existent, which combined with a rapidly drying column and increasing
W/NW (downslope) winds, will allow highs on Wednesday to reach
equally high, if not slightly warmer, than those which occurred
today. Highs on Wednesday will jump into the low to mid 70s, with
the warmest spots possibly being just away from the beaches where
downslope warming is maximized.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY NIGHT/...
As of 300 PM Tuesday...Basically a zonal mid level flow will
continue across the area through the period with high pressure
building at the surface. The subtle downslope component will
keep temperatures rather warm, some seven to ten degrees above
normal moreso for highs Thursday which range from the lower to
middle 70s under mostly sunny skies. Good radiational conditions
will allow Thursday morning mins to dip to near seasonal values
in the lower to middle 40s.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
As of 300 AM Tuesday...Strong Canadian high pressure should be
able to push a backdoor cold front through the area late Fri and
Fri night and we can not rule out a light shower during this
time. The front should push back into the area by Sat night.
Waves of low pressure will move along the front bringing a
likelihood for showers and some thunderstorms Sat night into
Sun. There is some potential for significant rainfall given the
magnitude and depth of the moisture return. As the final wave
moves across and then strengthens offshore, it will take the
front offshore. Cool and dry high pressure will follow from the
N and may attempt to wedge into the area early next week.
Highs in the lower to mid 70s Fri will cool into the 60s for the
remainder of the period. The coolest night will be Sun night
when most locations will dip to the upper 30s to lower 40s and
some spots could drop to the mid 30s.
&&
.AVIATION /03Z WEDNESDAY THROUGH SUNDAY/...
As of 00Z...A cold front will cross the terminals Wednesday
morning with scattered showers and increasing clouds, but VFR
will remain predominant. BKN to OVC cloud cover will overspread
the terminals ahead of the cold front, and MVFR is possible in
showers overnight. Our northern-most terminals of ILM and LBT
may see a brief period of IFR for low cigs in heavier showers.
Otherwise, the primary concern will be gusty S/SW winds of
10-15 kts through FROPA, becoming W/NW daytime Wednesday.
EXTENDED OUTLOOK...VFR except MVFR conditions possible in
showers Sat night.
&&
.MARINE...
NEAR TERM /THROUGH WEDNESDAY/...
As of 10 PM Tuesday...Southerly winds now in the 15 to 20 kt
range with seas of around 4 ft in advance of the next frontal
system. Forecast in good shape with no changes needed. Previous
discussion follows:
S/SW winds will steadily increase through tonight ahead of a
cold front which will cross offshore early on Wednesday. Winds
will rise to 15-20 kts this evening and tonight while slowly
veering more to the SW. Winds will then veer further on
Wednesday as the FROPA occurs during the morning, with gusty
W/NW winds of 15-20 kts easing slowly through the evening. These
gusty winds will create amplified short period waves, briefly
reaching 3-5 ft overnight, but will otherwise be 2-4 ft, falling
on the offshore winds late in the period.
SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY NIGHT/...
As of 300 PM Tuesday...The period begins with a light northwesterly
flow of ten knots or less with somewhat weak high pressure to the
west. By the end of the period the high will slowly recenter
offshore with a weak return flow developing. Once again the
gradient/systems are rather weak so it will be hard pressed to get
any winds over ten knots. Expect 2-4 feet seas early with the range
dropping off to 1-3 feet.
LONG TERM /FRIDAY THROUGH SUNDAY/...
As of 300 AM Tuesday...Strong Canadian high pressure should be
able to push a backdoor cold front through the waters late Fri
and Fri night. The front should push back into the waters Sat
night before finally getting shoved offshore by another front
Sun or Sun night as low pressure moves across the area and
offshore. The gradient may become pinched between building high
pressure and departing, but strengthening low pressure Sun and
Sun night.
SW winds Fri will shift to the N and NE Fri night. NE winds will
become E Sat and then veer to SE and S Sat night. The wind
direction on Sun will be SW, shifting to N Sun eve. The
strongest winds will occur Fri night, 15 to 20 kt. However, even
stronger winds are possible Sun and Sun night and a Small Craft
Advisory may be required. The highest seas will occur Fri night
and into the weekend, around 4 ft with 5 ft seas possible
across the outer waters. Seas could very well build to 6 ft or
higher during Sun and Sun night.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...None.
NC...None.
MARINE...None.
&&
$$
SYNOPSIS...SHK
NEAR TERM...JDW/SRP
SHORT TERM...SHK
LONG TERM...RJD
AVIATION...REK
MARINE...RJD/JDW/SHK
Area Forecast Discussion...UPDATED
National Weather Service Memphis TN
956 PM CST Tue Mar 7 2017
.UPDATE...
Light winds prevailed across the Midsouth at midevening. Skies
were clear over most of the region. High clouds from convection
along the central Gulf coast prevailed over northeast MS. 00Z GFS
depicted this high level moisture exiting during the overnight,
leaving clear skies.
Current setup favors efficient low level radiational cooling and
patchy fog formation in the low lying areas overnight. 9 PM
dewpoints were warmer than forecast overnight lows, but should
continue to slowly fall, in parallel with temps overnight. Last
several HRRR runs depicted low probabilities for dense fog, but
will continue to monitor.
PWB
&&
.PREV DISCUSSION... /issued 535 PM CST Tue Mar 7 2017/
UPDATE...
Updated to include 00Z aviation discussion below.
PREV DISCUSSION... /issued 341 PM CST Tue Mar 7 2017/
DISCUSSION...
The cold front has moved east of the area this afternoon, with
much drier air advecting into the CWA in its wake. Dewpoints have
fallen into the lower 30s across portions of northeast AR and the
MO Bootheel. Winds will become light and variable this evening as
the surface anticyclone settles over the area. Skies will continue
to clear and the dry air will promote radiational cooling.
Saturated soils should limit temperatures from getting below
freezing tonight, but we do anticipate a fair amount of low to mid
30s overnight, especially in low-lying areas and river valleys
across west TN and north MS. Farther west, return flow on the
backside of the surface high should keep the boundary layer a bit
more mixed. Patchy frost may be an issue overnight in the colder,
sheltered areas.
Generally benign weather is anticipated Wednesday and Thursday.
Southerly winds will resume across the area under strong quasi-
zonal flow aloft. The jet stream will remain well north of the
area tomorrow, settling over the Great Lakes. This will keep sky
conditions mostly sunny with afternoon temperatures of 65-70
degrees. Mid/high clouds are expected to increase across the Mid-
South by Thursday afternoon, but no precipitation is anticipated
through sunset. The increasing cloud cover could temper the
afternoon warm-up a bit on Thursday, but temperatures are expected
to reach the low to mid 70s across the area.
A compact, low-amplitude shortwave trough is progged to approach
the Mid-South Thursday night. Rain chances will increase during
the evening hours in the warm advection regime ahead of this
trough, but the primary focus will be the attendant cold front
diving south across the CWA during the late night and early
morning hours. Showers and thunderstorms are anticipated along
this front. SPC has highlighted part of the area in a marginal
risk for severe weather, but the greater probability of strong
storms will be farther west. Drier and cooler air will move into
the Mid-South on Friday, shunting rain chances south into northern
MS. High temperatures may remain in the 50s across the northern
portion of the CWA, but are still forecast to warm into the
mid/upper 60s south of I-40.
Generally dry weather is expected Friday night, but a stronger
shortwave trough is progged to affect the area on Saturday. A
reinforcing cold front is progged to sweep across the area during
coastal low deepens along the Gulf coast. Rain chances will
quickly ramp back up into the likely category (60-70%) Saturday
with a few strong storms possible along the cold front, mainly
over the southern counties. As the wave pulls out, cooler and
drier air will move into the CWA, bringing rain chances to an end
overnight. There is a brief window where a bit of light wintry
precipitation cannot be ruled out. A rain/snow mix was included
Saturday night, mainly north of a Jonesboro to Camden line. The
more likely scenario is that the precipitation pulls out before
the colder temperatures arrive, but there does remain considerable
uncertainty. We`ll continue to watch how this system evolves and
fine-tune the timing.
Both the Superblend and National Blend of Models indicate rain
chances on Monday, but the neither the GFS nor the ECMWF
deterministic solutions support this. Thus, dry weather is
currently forecast for Sunday and Monday. Temperatures will be a
bit cooler Sunday, with highs on the 50s, but should warm back
into the 60s early next week. We`ll have to watch temperatures on
Sunday morning as there is a potential for a few areas to
experience a light freeze. Stay tuned...
Johnson
&&
.AVIATION...
00Z TAFs
VFR conds through the period. Winds light and variable overnight,
becoming southwest 4 to 8 kts after 08/14Z.
AC3
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...None.
MO...None.
MS...None.
TN...None.
&&
$$
Area Forecast Discussion
National Weather Service Charleston WV
720 PM EST Tue Mar 7 2017
.SYNOPSIS...
Cold front passes this evening. High pressure Thursday.
A cold front crosses early Friday. Another system for next
weekend.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
As of 730 PM Tuesday...Made minor adjustments to refine PoP
based on radar trends and timing of frontal passage through the
region over the next few hours.
As of 645 PM Tuesday...Slightly tweaked sky cover with clearing
behind the front later tonight based on current movement and
meso model guidance.
As of 440 PM Tuesday...Updated PoP to reflect current RADAR
trends as two bands of rain push through the region this
evening. The first band is pushing through now and the second
band is associated with the cold front and will make it to the
Ohio River around 00Z. Between these two features I went ahead
and lowered PoP to slight chance with a clear gap indicated on
RADAR. However, I kept the forecast PoP fairly similar to the
previous forecast with the passing of the actual cold front.
Distinct clearing line behind the front seen on visible METSAT,
and next update will likely entail at what time to clear out
skies overnight.
As of 100 PM Tuesday...
Main forecast challenge hinges on timing precipitation today.
Leaned fairly heavily on a blend of HRRR, NAMNest and RAP
guidance. One area of showers moving through the northern
mountains early this afternoon will continue east away from the
CWA. Have more scattered showers for a time across central CWA,
before next band of more organized showers arrives from the
west. This band is currently making its way into SE Ohio, so
start with likely POPs there this afternoon, and gradually march
those across CWA from west to east. Models all fairly insistent
on another very thin line of shower with the actual cold front
which will move through this evening...so have another line of
likely POPs right with the front. Thought about taking out
thunder completely, but in the end decided to still leave an
isolated rumble in this afternoon across the central and
southern CWA.
Not a real cold punch behind the front, and have fairly mild
temperatures tonight and Wednesday. Do expect some gusty winds
on Wednesday. It`s fairly marginal, but decided to post a wind
advisory for the high terrain of Pocahontas and Randolph
counties late morning through the afternoon. Even across the
lowlands, winds will be on the gusty side...and with very dry
air at the surface we could hit some fire weather RH/wind
thresholds. However, ground should still be fairly soggy after
today`s rain, so fine fuels will likely not dry out enough to
cause enhance fire conditions. Will need to monitor this
tomorrow.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY NIGHT/...
As of 150 PM Tuesday...
The upper westerly flow transitions to a more northwesterly
component this period. This will allow a clipper type short
wave to push a cold front south and east across the area
Thursday night. A large Canadian high pressure system with much
colder air will then filter in behind the front. Enough
moisture and decent dynamics will be available to bring a band
of light rain showers with the front Thursday night, and change
to snow showers in the northern mountains before ending early
on Friday with little accumulation. Look for highs Thursday in
the 60s to highs Friday in the 40s.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
As of 200 PM Tuesday...
We still have a low pressure system to monitor over the weekend.
However, the models have shown a southward shift in the track
of the low across the southern states for Saturday and Saturday
night. It appears the northwest flow aloft over the eastern U.S.
will be be slower to lift out, thereby shunting the system
farther to the south. Thus, even though most of the models do
show most of the area experiencing at least some precipitation
from this system, the heaviest looks to be in the southern
portions of our area, while the heaviest of precipitation will
be south of the our area over the Tennessee valley and
Carolinas. On the other hand, this will help allow cold air to
hold over the area so that any precipitation that falls will
tend to be snow or a mix of rain and snow. Snow accumulations
are quite uncertain at this time frame as the track keeps being
adjusted by the models. It will definitely be a cold weekend
with temperatures well below normal. Then look for a warmup
early next week as the upper trough lifts out.
&&
.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
As of 750 PM Tuesday...
Cold front will be pushing through tonight with light rain and
low ceilings. Behind the front there is some drizzle and low
stratus before eventual clearing later tonight. Timing this
feature based on upstream observations and radar is a bit
tricky, but overall only thinking these IFR ceilings will last
about 2 hours or so. Dry air moves in behind a cold front for
around midnight and moves from west to east through early
morning. VFR conditions are expected with mostly clear skies
tomorrow.
Southerly winds will turn west-northwest behind the front. Will
be rather gusty on Wednesday.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z THURSDAY...
FORECAST CONFIDENCE: Medium tonight and high tomorrow.
ALTERNATE SCENARIOS: Timing of restrictions could vary with
passing cold front tonight.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE WED
UTC 1HRLY 00 01 02 03 04 05 06 07 08 09 10 11
EST 1HRLY 19 20 21 22 23 00 01 02 03 04 05 06
CRW CONSISTENCY L M M H M M L H H H H M
HTS CONSISTENCY H H M M H H H H H H H M
BKW CONSISTENCY M M H H H H M M H H H M
EKN CONSISTENCY M M H M L M M L M M H M
PKB CONSISTENCY H H H M H H H H H H H M
CKB CONSISTENCY M H H H M L L H H H H M
AFTER 00Z THURSDAY...
No widespread IFR conditions expected.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...Wind Advisory from 10 AM to 7 PM EST Wednesday for WVZ523-526.
OH...None.
KY...None.
VA...None.
&&
$$
SYNOPSIS...MZ/30
NEAR TERM...MZ/MPK
SHORT TERM...JMV
LONG TERM...JMV
AVIATION...MPK