Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 10/11/16
Area Forecast Discussion
National Weather Service La Crosse WI
629 PM CDT Mon Oct 10 2016
.SHORT TERM...(This evening through Tuesday)
Issued at 226 PM CDT Mon Oct 10 2016
Watching a well-defined short wave on water vapor imagery this
afternoon across eastern NE into western IA, which is forecast to
lift northeastward and across the forecast area overnight. While
latest RAP soundings show a relatively dry layer from the surface
to 5 kft through the night, a deeper saturated layer aloft should
result in at least scattered showers moving from southwest to
northeast across the area from 00Z tonight through 12Z tomorrow.
Low-level dry air should limit accumulations to a tenth of an inch
or less. While there could be a stray lightning strike or two
based on the strength of the wave aloft, models show no instability
through the atmospheric column, so will keep activity as all
showers. Under mostly cloudy skies and breezy southerly winds,
temperatures tonight will only drop into the 50s.
Once early morning showers push east of the forecast area, Tuesday
will be warm and dry with breezy southerly winds, gusting at times
to 25 mph. Highs will reach the mid 60s to lower 70s region-wide.
.LONG TERM...(Tuesday night through Monday)
Issued at 226 PM CDT Mon Oct 10 2016
Showers return late Tuesday night through Wednesday as a cold
front sweeps across the region. Perhaps a slightly better chance
for a few rumbles of thunder compared to tonight given models
depiction of a few hundred J/kg of MUCAPE ahead of the front, but
confidence not high enough to introduce thunder at this time with
much of the precip likely to be post-frontal. Rain amounts
Wednesday will not be undercut by low-level dry air, so up to a
quarter of an inch seems reasonable at this time. Wednesday`s
highs from the upper 40s to lower 50s will likely occur in the
morning with falling temperatures through the rest of the day
behind the front.
Skies clear out quickly Wednesday night into Thursday morning, and
with 925 hPa temperatures approaching zero Celsius, could see our
first widespread freeze of the season.
Thursday/Friday will be dry as high pressure moves across the
Upper Midwest. Cool temperatures from the upper 40s and 50s on
Thursday will warm to near 60 degrees to end the work week.
Precipitation chances return Saturday as another eastern Pacific
wave moves quickly across the nation`s mid-section. Modest low-mid
level moisture advection ahead of the wave suggests the potential
for a plume of higher instability, so will introduce a chance of
thunder Saturday afternoon and evening.
After a brief respite on Sunday with short-wave ridging aloft, the
next shot for showers and storms will arrive late Sunday night
into Monday with yet another stronger Pacific wave.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 629 PM CDT Mon Oct 10 2016
Mid level clouds in the 7-11k ft range will continue to thicken
through the evening in advance of an approaching upper wave of low
pressure. That feature should eventually deliver some showers to
the area later tonight but with conditions holding VFR through the
entire night. Watch for low level wind shear at the LSE terminal
through much of the night, while RST sees high enough surface
winds in the 12-16 knot range to preclude LLWS there. Showers
will end from west to east 9-13Z, with skies expected to clear
through midday Tuesday before additional mid level clouds roll in
from the west late in the day.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
IA...None.
&&
$$
SHORT TERM...ROGERS
LONG TERM...ROGERS
AVIATION...Lawrence
Area Forecast Discussion...Updated
National Weather Service Billings MT
828 PM MDT Mon Oct 10 2016
.UPDATE...
No changes planned this evening to the going forecast. Snow has
already begun to fall over western zones this evening with
temperatures dropping below freezing over northwest areas. Cold
front has pushed all the way through the forecast area with
temperatures ranging from 26 in Judith Gap to 43 degrees around
Alzada. Jet feature that is to produce snow into the late night
hours is pronounced on water vapor with enhancement showing up
all the way west into Oregon.
One concern this evening is that the orientation of the
initial precipitation band is a bit more north/south oriented
than expected. This may keep heaviest precipitation from working
into areas from Billings to Hardin and Miles City until the early
morning hours. NAM and HRRR both grabbing onto this thought, but
tend to lean toward the global models (GFS and ECMWF) for these
jet dynamic systems so holding off making any changes just yet. It
may be that the downslope off the eastern Beartooth is whats
inhibiting precipitation from orienting into the central zones
right now, but that as the colder air/northeast winds deepen
along the breadth of the foothills precipitation will shift
further southeast as the EC/GFS have been advertising. Also, cold
air is further south than models had been depicting by this point
which should pull the jet southward and thus orient
dynamics/precipitation a bit further southeast later tonight. If
not mid shift will have to adjust precipitation/snow accumulations
accordingly. All models continue to advertise a broad band of
precipitation spreading through the advisory area beginning around
sunrise and continuing through mid day Tuesday.
For Billings it still looks like the heaviest precipitation/snow
will occur between 3am and 9am, just in time for the morning
commute.
Remember that even though road temperatures look warm enough to
keep roads mainly wet in most areas, bridges and overpasses will
ice up quickly as temperatures hit freezing so be cautious
traveling tonight and tomorrow. Chambers
&&
.SHORT TERM...valid for Tue and Wed...
A large contrast in temperatures across the area late this
afternoon with 30s across the north and 60s to near 70 degrees
across southeastern portions of the area. Stubborn low clouds have
persisted across a large portion of central areas, but have begun
to lift as mixing increases with the approach of the next storm
system. Colder temperatures were surging in from the north along
with gusty northerly winds and will continue to spread across the
area through the evening.
Areas of south central and southeast Montana are still on track
to see wintry precipitation starting tonight and continuing
through Tuesday. Precipitation will begin to develop over the west
late this afternoon/evening as jet dynamics and strong vorticity
advection move over the area. This in concert with frontogenesis
associated with the cold air advection and upslope flow along the
foothills and mountains, will allow for a west to east
precipitation band to form across the area. Models remain in
agreement in a rain and snow mix this evening eventually turning
to snow overnight and continuing into Tuesday as colder
temperatures work in. Can`t rule out some isolated pockets of
freezing drizzle, but am not expecting it to be widespread. Upper
dynamics will gradually slide south and east through the day
Tuesday with just some flurries lingering across eastern portions
of the area by late in the day/early evening. Exact placement of
the precipitation band is still somewhat uncertain, but this is
only an issue with heaviest rates as all but the very SE zones
will likely see some amount of measurable precipitation.
Snowfall amounts may vary considerably across the area, and any
deviation in the placement of the aforementioned precipitation
band could mean more snow for some areas and less for others. Plus,
ground and road temperatures are relatively warm and should limit
accumulations until late tonight. Roads may remain wet to slushy
for a time. Bridges and overpasses will likely become icy. A
widespread 2 to 5 inches can be expected for the lower elevations
with locally higher amounts possible. As for the mountains,
amounts are generally expected to remain below our warning
criteria (12 inches), and initial snow ratios look low due to
shallow nature of coldest air.
All this being said, a widespread snowfall is expected and have
continued the Winter Weather Advisories for western and central
areas and have expanded them to include Custer and Fallon
counties. Advisories across the northwest will start this evening
with central zones starting late evening, and southern and far
northeastern zones starting late tonight, continuing into Tuesday.
Temperatures will struggle to make it out of the upper 20s and low
30s on Tuesday, with the coldest night of the Fall so far expected
for Tuesday night with temperatures in the teens to lower 20s
expected. This will vary depending on cloud and snow cover. Roads
will likely be icy Tuesday night due to recent snowfall. STP
.LONG TERM...valid for Thu...Fri...Sat...Sun...Mon...
Heights will rise as ridge builds in from the west Wednesday. This
will bring a period of dry wx along with warming temperatures
Wednesday and Thursday. Lower elevation snow cover will no doubt
melt with temps back to the 40s Wednesday and 50s to near 60F
Thursday.
Weather pattern will shift to one of moist Pacific flow from
Friday through next Monday. A series of shortwaves will result in
periods of rain/snow over our western aspects, including the
mountains around Cooke City. Have raised high elevation pops
during some of these periods. Lower elevations may see some
lighter rain showers at times, but otherwise downslope flow will
prevail. Temperatures will be near or above normal for mid
October.
JKL
&&
.AVIATION...
Snow and IFR conditions are already occurring in KLVM...and are
expected to continue to diminish. The developing weather system
will bring widespread snow and deteriorating flight conditions
through tonight and Tuesday. Expect MVFR- LIFR and mountain
obscurations across the region. Precipitation will taper off from
NW to SE tomorrow afternoon. JKL/AAG
&&
.PRELIMINARY POINT TEMP/POPS...
Tue Wed Thu Fri Sat Sun Mon
-----------------------------------------------------------
BIL 028/031 022/044 031/058 045/067 045/063 046/065 045/062
9+/S 10/U 00/U 11/B 22/W 11/B 12/W
LVM 030/035 023/051 034/061 044/063 045/059 044/061 043/059
86/S 10/N 00/U 12/W 22/W 22/W 22/W
HDN 031/033 021/042 029/058 040/065 043/063 044/066 044/062
6+/S 10/U 00/U 01/B 22/W 11/B 12/W
MLS 032/035 025/043 028/056 039/066 045/064 044/065 043/064
57/S 10/U 00/U 00/B 11/B 11/B 12/W
4BQ 035/036 024/047 030/060 041/073 046/066 044/069 044/067
16/S 30/U 00/U 00/B 21/B 11/B 11/B
BHK 030/035 021/040 026/055 036/066 042/061 040/063 042/062
37/S 20/U 00/U 00/B 11/B 11/B 01/B
SHR 035/036 022/048 029/060 040/068 042/062 041/066 043/062
26/S 30/U 00/U 01/B 12/W 11/B 12/W
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...Winter Weather Advisory in effect until 3 PM MDT Tuesday FOR
ZONES 28>31-34-35-40>42-56-63>66.
Winter Weather Advisory in effect from midnight tonight to 6
PM MDT Tuesday FOR ZONES 32-33-38-39-57-58.
WY...None.
&&
$$
weather.gov/billings
Area Forecast Discussion
National Weather Service Green Bay WI
1055 PM CDT MON OCT 10 2016
Updated aviation portion for 06Z TAF issuance
.SYNOPSIS...
Issued at 222 PM CDT Mon Oct 10 2016
Warm again tomorrow, then turning cooler mid-week. Scattered
showers tonight, with a better chance for rain Tuesday night and
Wednesday.
The amplitude of the upper flow over the eastern Pacific and North
America will peak during the next couple days. By mid-week, a
strong jet driving eastward from the Pacific will undercut the
sharp ridge near the West Coast. The jet will continue to expand
east, establishing a broad-low amplitude trough over the eastern
Pacific and western CONUS by next weekend.
Another day of above normal temperatures is expected tomorrow,
then readings will briefly drop back close to seasonal normals
mid-week, before returning to above normal levels for the weekend.
There appears to be sufficient opportunities for precipitation to
result in near or modestly above normal amounts for the period.
&&
.SHORT TERM...Tonight and Tuesday
Issued at 222 PM CDT Mon Oct 10 2016
The latest RAP analysis and satellite/radar imagery show the state
of Wisconsin located between high pressure centered over the eastern
Great Lakes, low pressure over the Dakotas, and a shortwave swinging
northeast over Kansas. A tight pressure gradient between these
features is contributing to gusty southwest winds up to 25 kts.
Cirrus ahead of the shortwave is working into southwest Wisconsin,
but precipitation remains well southwest of the region. As the
shortwave moves into the area late tonight, precip chances/trends
are the main forecast concerns.
Tonight...The shortwave over the central Plains will lift northeast
and move into the region late tonight. At the same time, a pwat
axis will shift east across the western half of the state. The
increasing moisture and forcing from the shortwave will therefore
lead to a chance of showers spreading from southwest to northeast
from late this evening into the overnight over central and north-
central WI. Drier air below 10kft should keep eastern sections of
the state dry though. Southerly winds and increasing clouds calls
for warmer low temps, and will go with low to mid 50s.
Tuesday...The chance of rain will spread to the east during the
morning hours as the shortwave progresses across the eastern parts
of the state. Low and mid-level moisture appears to thin out
somewhat as this occurs, so chances of precip will likely gradually
diminish through the morning. Then should see drier air arrive
behind the shortwave in the afternoon, when at least partial
clearing should occur from southwest to northeast. Not as confident
though about clearing occurring over north-central Wisconsin, due to
the closer proximity of a cold front, which will be pushing into
northwest Wisconsin in the afternoon. With at least some sun, temps
should rise into the 60s.
.LONG TERM...Tuesday Night Through Monday
Issued at 222 PM CDT Mon Oct 10 2016
The combination of the frontal system and shortwave crossing the
area Tuesday night and Wednesday should generate fairly widespread
rains across the area. The exact timing is still somewhat
uncertain, though the greatest chance for preciptiation will
probably be Wednesday. Still would not be surprised if the precip
lingers a little longer than currently forecast.
A brief return to cooler weather is expected as a Canadian air
mass sweeps into the area in the wake of the front. But the cooler
air will quickly shift off to the east. A shortwave and frontal
system will bring another chance of rain during the weekend.
&&
.AVIATION...for 06Z TAF Issuance
Issued at 1054 PM CDT Mon Oct 10 2016
Low-level wind shear will develop this evening ahead of an upper
level disturbance tracking in from the southwest. This disturbance
will bring lower cloud bases during the overnight hours. There
will also be a chance for showers later tonight, mainly across the
northern and western TAF sites where better moisture and lift
will exist. There will also be a chance for showers across the
eastern TAF sites Tuesday morning, however moisture and lift will
be too limited to include in this set of TAFs. There is potential
for MVFR cigs as well, mainly across the north-central Wisconsin
TAF sites late tonight and into Tuesday morning. VFR conditions
are expected to return later Tuesday afternoon and Tuesday evening
as another low pressure system approaches from the west.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS.......Skowronski
SHORT TERM.....MPC
LONG TERM......Skowronski
AVIATION.......Kurimski
Area Forecast Discussion
National Weather Service Lake Charles LA
1005 PM CDT MON OCT 10 2016
.DISCUSSION...Surface trof advancing west across the near coastal
waters and accompanied with a few showers. Ongoing forecast
has low end pops for this area. Forecast looks good and see no
need for an update.
&&
.PREV DISCUSSION... /issued 658 PM CDT MON OCT 10 2016/
DISCUSSION...
For 00z TAF issuance.
AVIATION...
Satellite imagery showing afternoon cu dissipating as we head
towards sunset...and skies should generally clear through the
night across much of the area. Kept the inherited light fog going
late tonight at KAEX where slight restrictions to visibility are
climatologically-favored. Tomorrow continues to look like a VFR
day with a little more cu with daytime heating. HRRR points at the
potential for a few showers near KBPT...will take a closer look at
this possibility with the 06z issuance.
25
PREV DISCUSSION... /issued 308 PM CDT MON OCT 10 2016/
DISCUSSION...High pressure is moving east across the Great Lakes
region this afternoon. This ridge had been producing a generally
northeast flow over the past couple of mornings which was
providing pleasant weather. The ridge will continue to move into
New England and this will turn the flow off the gulf which will
increase moisture levels and temps. With the return of moisture
tonight and into Tuesday, a few showers will be possible along the
coast of far SW LA and SE Tx tonight and across SE TX tomorrow.
Wednesday through Friday and upper lvl ridge will hold steady
while moisture increases. This will keep pops to a minimum while
temps run around 5 degrees above normal.
This weekend the upper ridge will break down allowing for a few
showers and storms, but overall pops will remain limited. No
significant cold fronts are expected, and this will keep temps
above normal into next week.
MARINE...A light to moderate east to southeast flow is expected
through the period.
&&
.PRELIMINARY POINT TEMPS/POPS...
AEX 59 86 59 87 / 0 0 0 0
LCH 67 85 66 85 / 10 10 0 0
LFT 64 87 63 87 / 10 0 0 0
BPT 67 85 68 87 / 10 20 0 10
&&
.LCH Watches/Warnings/Advisories...
LA...None.
TX...None.
GM...None.
&&
$$
PUBLIC...04
Area Forecast Discussion
National Weather Service Miami FL
802 PM EDT Mon Oct 10 2016
.UPDATE...
Northeast winds remain gusty this evening, but are expected to
wane slightly tonight. Relatively low dew points, in the mid 60s,
should make conditions feel less humid than previous nights and
allow temperatures to drop to the upper 60s (western interior) and
lower/mid 70s elsewhere. Through the remainder of tonight, the
HRRR and HiRes WRF models advect isolated light showers from the
Atlantic towards the east coast metro. A slight chance of
occurrence seems warranted, but not expecting much in the way of
accumulation.
&&
.PREV DISCUSSION... /issued 608 PM EDT Mon Oct 10 2016/
DISCUSSION...
Scattered stratocumulus clouds resided over South
Florida this afternoon with little in the way of convection,
according to IR satellite imagery. Northeast winds have been steady
over the past 12 hours, generally 10-15 mph with gusts up to around
20 mph. Less oppressive conditions were also noted today, due to the
lower than average maximum temperatures and dewpoints down to the
mid 60s. On this mornings MFL sounding, an extremely dry atmosphere
was observed both in the mid and upper levels. The PW value had
dropped to 0.81", a record low for this date. Tonight, isolated
showers over the Atlantic may advect towards the east coast metro,
but activity should be light. High pressure over the northeast Gulf
will maintain similar conditions for tomorrow with a very slight
increase in maximum temperatures and dewpoints. A stray shower can`t
be ruled out along the east coast, but with such dismal forecast
CAPE values, thunder doesn`t appear likely.
Wednesday through Saturday: Stagnant high pressure ridging over the
Southern CONUS will allow for a continued northeast flow across
South Florida. This pattern typically favors near normal
temperatures, gusty northeast winds, and periodic light to moderate
showers which mainly affect the eastern portion of the peninsula.
Instability parameters remain low through the week, so have kept the
mention of thunder out of the latest package. By early next week,
both the GFS and ECMWF shift aforementioned ridge of high pressure
off the central eastern seaboard, which would act return southeast
flow and increase moisture across southern Florida.
MARINE...
Strong northeast flow will continue to create rough seas,
particularly along the Gulf stream. Winds, 15-25 KT are expected
to continue through late Wednesday over the Atlantic waters, then
diminish slightly after mid-week. Seas will then follow suit.
Mariners should exercise caution and remain aware of the latest
forecasts.
BEACH FORECAST...
Strong northeast flow is creating an environment along the
Atlantic beaches that will allow for moderate to strong rip
currents. This elevated risk for rip currents will continue
through tonight.
&&
AVIATION...
VFR flying conditions are expected to prevail throughout the TAF
period. Some brief high-end MVFR ceilings and sprinkles will be
possible this afternoon at the east coast TAF sites, but
confidence and duration was not high enough to include in the TAFs
at this time. Northeast winds will be 10-15 knots with occasional
gusts of 20-25 knots this afternoon, diminishing to around 10
knots overnight.
&&
.PRELIMINARY POINT TEMPS/POPS...
West Palm Beach 75 86 77 85 / 20 20 20 40
Fort Lauderdale 75 86 77 86 / 20 20 20 30
Miami 74 87 76 87 / 20 20 20 20
Naples 68 87 70 87 / 10 10 10 10
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...High Rip Current Risk until 6 AM EDT Tuesday for FLZ168-172-173.
AM...Small Craft Advisory until 8 PM EDT Wednesday for AMZ650-651-670-
671.
GM...Small Craft Advisory for winds until 4 AM EDT Tuesday for GMZ676.
&&
$$
DISCUSSION...27/JT
MARINE...27/JT
AVIATION...92/IRL
UPDATE...27/JT
Area Forecast Discussion
National Weather Service Gaylord MI
332 AM EDT Tue Oct 11 2016
.SHORT TERM...(Today and tonight)
Issued at 330 AM EDT Tue Oct 11 2016
High impact weather potential: none.
High pressure is over the northeast states and moving east. A cold
front extends from James Bay, to just nw of Superior, to the central
high plains. Southerly low-level flow between these two features is
resulting in warm advection over northern MI. Ridging from the high
extends into the deep south, which is limiting the amount of
moisture return into the region. That largely holds thru tonight,
though an ejecting shortwave may result in some sct showers/
sprinkles. Precip and cloud trends are the main concern.
Today...upstream shortwave is contributing to shower/t-storm
activity in parts of Iowa, showers further ne into central WI, and
some sprinkles/virga e and n of that. Associated cloud field has
a very baroclinic-leaf-look on satellite, though there is no
surface reflection. This wave will eject ne, crossing Lake MI this
afternoon, as it presses into broad ridging aloft over the eastern
states.
Initial band of returns aloft is pushing into nw lower MI. Not
all of this is necessarily virga, as MTW reported some -RA at
around midnight EDT. But we have plenty of dry air present below
approx 805mb, per the 00z APX sounding (dew pt depressions
20-25C). Difficult to see more than a few sprinkles in nw lower
MI, mainly early this morning. Eastern upper will have a
considerably better chance for precip, as they benefit from a
stronger sw 850mb jet (30-35kt). In addition, the upstream
trajectory into eastern upper taps a more moist airmass. Will
mention sct sprinkles and showers in eastern upper MI this
morning, with the best chance west of I-75. Somewhat better
chance for rain in eastern upper looks to be late afternoon into
early evening, per recent Nam and Rap guidance. However, Rap
hour-to-hour runs have been somewhat inconsistent, so will keep
pops on the small side.
Cloud cover already expanding into northern MI, and those clouds
will further increase and thicken. Some thin spots will be seen
occasionally, which will help temps rebound. Max temps will range
mainly thru the 60s, though a few spots will take a run at 70f
(including TVC, thanks to a downsloping south breeze).
Tonight...shortwave and attendant area of mid/upper-level moisture
will exit off to the ne quickly in the mid/late evening hours. May
need to hang onto a few showers in eastern upper mi early on. Much
more prominent upper trof will dig into the northern plains.
Cyclogenesis will proceed on the upstream cold front in response,
with a deepening surface low moving from the MN/WI border area to
almost James Bay by morning. The front itself will push into central
upper MI and central WI my morning, still just upstream. Most precip
is progged to be post-frontal, in zone of strongest height falls.
Though a thin moist layer is progged on between 800 and 700mb, in
general northern lower MI will see at least partial clearing,
especially after midnight. Eastern upper MI will be something of an
exception, with ticker cirrus advecting in from the sw even as mid-
clouds thin. This will result in a window for radiative cooling,
especially in sheltered locales in n central and ne lower, where the
pressure gradient is more lax. Min temps will dip back into the mid
40s to around 50f there, vs 50s in nw lower and eastern upper MI.
.LONG TERM...(Wednesday through Monday)
Issued at 330 AM EDT Tue Oct 11 2016
...Transition from warm to cold midweek to be accompanied by
rain/wind...
High Impact Weather Potential: Rain on Wednesday...low probability
for thunderstorms across northern Lower during the afternoon but if
they do develop then a conditional gusty wind threat. Winds should
be gusty regardless...could be brief period of 30-40mph winds right
behind a passing cold front.
Pattern Forecast: Large scale pattern features a positive tilt upper
trough extending from a parent upper low north of Hudson Bay...
southwest across Saskatchewan/Alberta and extending into the Pacific
northwest. Broad southwest flow encompasses much of the continental
U.S...compact short wave trough rotating northeast across Iowa early
this morning. Focus for this week`s weather will be on the slow
eastward progression of the upstream height falls across the
northern tier of states...with the base of this trough expected to
swing through the Great Lakes in the later Wednesday/Thursday time
frame. Flow is expected to quickly become zonal again by Friday...
a relatively mild pattern downstream of rather persistent negative
height anomalies over the northeast Pacific. Short wave energy
being ejected from this persistent long wave troughing may have
impacts on Great Lakes weather this weekend (the latter half in
particular).
A stretched out cold front lying from northern Ontario southwest
across northwest Minnesota/South Dakota early this morning will take
its time move east over the next 48 hours...waiting on height falls
from its parent upper trough to give it a push. This front is
forecast to cross northern Michigan Wednesday afternoon/evening...
accompanied by a very noticeable drop in temperatures for Thursday.
High pressure will dominate Friday...before shifting east and
allowing temperatures to moderate again for the weekend. Another
cold front will be lurking for Sunday.
Primary Forecast Concerns: Evolution of rain event Wednesday/
Wednesday night associated with the approaching cold front is the
initial forecast concern. Does look like the forecast trend is a
bit slower...which should allow for a warmer afternoon and a later
onset of precipitation. As mentioned in this space last night...
uncertain whether heating ahead of the front and a modest low level
moisture return might be sufficient to kick off some thunderstorms.
A low probability event but enough to consider adding to the
forecast for northern Lower. Better chance looks to be across
southern Lower but may see remnants of this activity drift into
northeast lower during late afternoon. Will make some adjustments
to precipitation timing but looks like approaching post-frontal rain
band and pre-frontal convective development will result in
precipitation "filling-in" during the afternoon. A decent though
quick-hitting shot of rainfall expected with a nice push of 1.25
inch precipitable water values (about 2 standard deviations above
the mean and more than 200 percent above normal)...a tight
baroclinic zone and right rear quadrant jet forcing should be able
to squeeze out 0.50+ inch of rain in spots. Frontal rain band
expected to sweep into Lake Huron by the pre-dawn hours of
Thursday...but with 850mb temperatures plunging below zero some
northwest flow lake induced rain showers will be developing in its
wake heading into Thursday.
Precipitation along the leading edge of the frontal rain band...or
any pre-frontal convective development...may be accompanied by gusty
winds. There will be gusty "synoptic" winds associated with the
cold front...both ahead of the front with fairly deep mixing...and
right behind the front aided by tight isallobaric component. Gusts
ahead of the front likely over 30 mph...and at least that if briefly
not more with cold front passage.
Scattered lake induced rain showers should be ongoing Thursday
morning. Consensus PoP forecast was a bit dry so blended in SREF
PoPs in order to get the idea in the forecast. Boundary layer
should still be warm/deep enough to keep precipitation all rain
(with lake temperatures still at or above 15c...typically takes
850mb temperatures of at least -6C for snow across the interior...
and around -9c near the lakeshores). Precip coverage expected to
wane during the afternoon as high pressure/anticyclonic flow build
in. Temperatures a good 20 degrees below Wednesday highs with many
areas seeing temperatures remain in the 40s.
No weather impacts Friday...Saturday could be breezy while rain
chances expected to ramp up again Saturday night/Sunday. Mild
temperatures expected Saturday through Monday.
&&
.AVIATION...(For the 06Z TAFS through 06Z Tuesday night)
Issued at 1131 PM EDT Mon Oct 10 2016
Solid VFR conditions will persist overnight through Tuesday
evening although mid and high cloud cover will overspread the
region. A few sprinkles are possible, but no significant weather
is anticipated. LLWS is also a possibility overnight, as low
level flow increases off the surface. Some gustiness is possible
through the day Tuesday.
&&
.MARINE...
Issued at 330 AM EDT Tue Oct 11 2016
Breezy southerly winds will continue until Wednesday, when a sharp
cold front will slowly move across northern MI from midday thru
early evening. Those initial southerly winds and a long fetch
will result in small craft advisory conditions on Lake MI and
Whitefish Bay. Marine headlines will become more widespread on Wed
and Wed night, with gusty nw to n winds behind the front.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...SMALL CRAFT ADVISORY until 8 AM EDT Wednesday for LMZ323-341-342-
344>346.
LS...SMALL CRAFT ADVISORY until 8 AM EDT Wednesday for LSZ321.
&&
$$
SHORT TERM...JZ
LONG TERM...JPB
AVIATION...Adam
MARINE...JZ
Area Forecast Discussion
National Weather Service Houston/Galveston TX
345 AM CDT Tue Oct 11 2016
.DISCUSSION...
The most notable weather driver for the next week or so should be
a high pressure ridge aloft, but periodically interrupted by upper
troughs to the north for a few chances for scattered showers or
storms. The best potential for rain may come today, but there will
be another chance Thursday/Friday along with a weakening front.
Today through Wednesday night...
After a very dry stretch, precipitable water is in the process of
surging into the area thanks to onshore flow. Precipitable water,
which had been well below an inch, shows a moist tongue over our
Gulf waters right around 1.5 inches. In that region, radar shows
several showers popping up over the Gulf waters, and have even
begun to impinge on coastal areas both along the Louisiana border
and in Brazoria County. Would expect coastal areas to see
potential for isolated to widely scattered showers through the
morning. As the day brings further heating, moisture improves, and
support for vertical motion may be boosted by subtle vorticity
advection associated with a trough lifting towards the Great
Lakes, scattered showers and some storms should be expected even
farther inland. This shows up pretty well in CAMs such as recent
hours of the HRRR and the TTU WRF model. Both of these are
actually pretty aggressive with convection, and push showers well
inland even this morning, so I`ve nudged early PoPs up, but
still think it will take longer for the column to moisturize than
shown in these model runs.
After today, ridging aloft should reassert itself, so Wednesday
should be drier and warmer, with many locations pushing into the
upper 80s to around 90 degrees. There may be scattered spots that
see heat indices near 100 degrees to go along with that, but
should be very localized with most looking to max out in the mid
90s.
Thursday through Saturday...
Midlevel heights look to come down a touch Thursday, which could
allow for a bit of an increase in convection, but the better
chance would be associated as a cold front moves into Texas. The
GFS is a bit faster, which would further bolster potential on
Thursday, while the Euro is a bit slower and focuses more on
Friday (for what it`s worth, the NAM comes in between, shading
more towards the GFS on timing, but more like the Euro on strength).
The globals are much more pessimistic about this front`s
potential, looking like it washes out before pushing too far into
SE Texas and keeping best rainfall potential to our northwest. The
Euro and NAM seem to provide enough instability aloft with the
shortwave a bit deeper, but not strong enough that it could
overcome poor timing (hence the drier Euro). Still, if things line
up right, we could pop up some decent storms...I`m just not buying
that solution right now.
Next week...
The ridge aloft again reasserts itself, and we may again be
looking at temperatures right around 90 degrees for much of the
inland area. Onshore flow continues, which should at least keep
boundary layer moisture up. This won`t make afternoon convection
totally impossible, but would expect isolated showers/storms at
most. Tuesday might have the best shot with a potent trough along
the Canadian border possibly decreasing stability here a bit, but
that`s probably really stretching the potential there. It`s beyond
the scope of this forecast, but both the GFS and Euro seem to be
fans of digging a pretty significant upper trough next week,
moving into Texas late. However, the NAEFS mean is decidedly
unimpressed with near-average height fields, so while it`s fun to
drift to the next big deviation from the current dull pattern,
let`s not get carried away with this idea just yet.
25
&&
.MARINE...
Small craft exercise caution flags are up across the eastern waters
for elevated winds as a wave and associated showers and/or
thunderstorms moves across the area. Look for lowering winds tonight
and on into Wednesday with this light to moderate onshore flow
persisting for the rest of the week and on into the upcoming weekend.
If the current forecast holds, the area`s next cold front doesn`t
arrive until the middle to end of next week. 42
&&
.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL) 84 70 88 70 87 / 20 10 10 10 20
Houston (IAH) 83 71 87 70 88 / 30 10 10 10 10
Galveston (GLS) 83 76 85 76 85 / 30 10 10 10 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION through this evening FOR THE
FOLLOWING ZONES: Coastal waters from High Island to
Freeport out 20 NM...Waters from High Island to Freeport
from 20 to 60 NM.
&&
$$
Discussion...25
Aviation/Marine...42
Area Forecast Discussion
National Weather Service Gaylord MI
1148 AM EDT Tue Oct 11 2016
.UPDATE...
Issued at 1143 AM EDT Tue Oct 11 2016
Moisture starved short wave evident on water vapor imagery will
continue to move across the region this afternoon. Low levels
remain rather dry per model/observed soundings so only
sprinkles/virga expected except for a possible light shower or two
across eastern upper where moisture is a little deeper.
Temperatures continue to inch up (offset by evaporative cooling
aloft) but should still reach into the lower and middle 60s by the
end of the day.
&&
.SHORT TERM...(Today and tonight)
Issued at 330 AM EDT Tue Oct 11 2016
High impact weather potential: none.
High pressure is over the northeast states and moving east. A cold
front extends from James Bay, to just nw of Superior, to the central
high plains. Southerly low-level flow between these two features is
resulting in warm advection over northern MI. Ridging from the high
extends into the deep south, which is limiting the amount of
moisture return into the region. That largely holds thru tonight,
though an ejecting shortwave may result in some sct showers/
sprinkles. Precip and cloud trends are the main concern.
Today...upstream shortwave is contributing to shower/t-storm
activity in parts of Iowa, showers further ne into central WI, and
some sprinkles/virga e and n of that. Associated cloud field has
a very baroclinic-leaf-look on satellite, though there is no
surface reflection. This wave will eject ne, crossing Lake MI this
afternoon, as it presses into broad ridging aloft over the eastern
states.
Initial band of returns aloft is pushing into nw lower MI. Not
all of this is necessarily virga, as MTW reported some -RA at
around midnight EDT. But we have plenty of dry air present below
approx 805mb, per the 00z APX sounding (dew pt depressions
20-25C). Difficult to see more than a few sprinkles in nw lower
MI, mainly early this morning. Eastern upper will have a
considerably better chance for precip, as they benefit from a
stronger sw 850mb jet (30-35kt). In addition, the upstream
trajectory into eastern upper taps a more moist airmass. Will
mention sct sprinkles and showers in eastern upper MI this
morning, with the best chance west of I-75. Somewhat better
chance for rain in eastern upper looks to be late afternoon into
early evening, per recent Nam and Rap guidance. However, Rap
hour-to-hour runs have been somewhat inconsistent, so will keep
pops on the small side.
Cloud cover already expanding into northern MI, and those clouds
will further increase and thicken. Some thin spots will be seen
occasionally, which will help temps rebound. Max temps will range
mainly thru the 60s, though a few spots will take a run at 70f
(including TVC, thanks to a downsloping south breeze).
Tonight...shortwave and attendant area of mid/upper-level moisture
will exit off to the ne quickly in the mid/late evening hours. May
need to hang onto a few showers in eastern upper mi early on. Much
more prominent upper trof will dig into the northern plains.
Cyclogenesis will proceed on the upstream cold front in response,
with a deepening surface low moving from the MN/WI border area to
almost James Bay by morning. The front itself will push into central
upper MI and central WI my morning, still just upstream. Most precip
is progged to be post-frontal, in zone of strongest height falls.
Though a thin moist layer is progged on between 800 and 700mb, in
general northern lower MI will see at least partial clearing,
especially after midnight. Eastern upper MI will be something of an
exception, with ticker cirrus advecting in from the sw even as mid-
clouds thin. This will result in a window for radiative cooling,
especially in sheltered locales in n central and ne lower, where the
pressure gradient is more lax. Min temps will dip back into the mid
40s to around 50f there, vs 50s in nw lower and eastern upper MI.
.LONG TERM...(Wednesday through Monday)
Issued at 330 AM EDT Tue Oct 11 2016
...Transition from warm to cold midweek to be accompanied by
rain/wind...
High Impact Weather Potential: Rain on Wednesday...low probability
for thunderstorms across northern Lower during the afternoon but if
they do develop then a conditional gusty wind threat. Winds should
be gusty regardless...could be brief period of 30-40mph winds right
behind a passing cold front.
Pattern Forecast: Large scale pattern features a positive tilt upper
trough extending from a parent upper low north of Hudson Bay...
southwest across Saskatchewan/Alberta and extending into the Pacific
northwest. Broad southwest flow encompasses much of the continental
U.S...compact short wave trough rotating northeast across Iowa early
this morning. Focus for this week`s weather will be on the slow
eastward progression of the upstream height falls across the
northern tier of states...with the base of this trough expected to
swing through the Great Lakes in the later Wednesday/Thursday time
frame. Flow is expected to quickly become zonal again by Friday...
a relatively mild pattern downstream of rather persistent negative
height anomalies over the northeast Pacific. Short wave energy
being ejected from this persistent long wave troughing may have
impacts on Great Lakes weather this weekend (the latter half in
particular).
A stretched out cold front lying from northern Ontario southwest
across northwest Minnesota/South Dakota early this morning will take
its time move east over the next 48 hours...waiting on height falls
from its parent upper trough to give it a push. This front is
forecast to cross northern Michigan Wednesday afternoon/evening...
accompanied by a very noticeable drop in temperatures for Thursday.
High pressure will dominate Friday...before shifting east and
allowing temperatures to moderate again for the weekend. Another
cold front will be lurking for Sunday.
Primary Forecast Concerns: Evolution of rain event Wednesday/
Wednesday night associated with the approaching cold front is the
initial forecast concern. Does look like the forecast trend is a
bit slower...which should allow for a warmer afternoon and a later
onset of precipitation. As mentioned in this space last night...
uncertain whether heating ahead of the front and a modest low level
moisture return might be sufficient to kick off some thunderstorms.
A low probability event but enough to consider adding to the
forecast for northern Lower. Better chance looks to be across
southern Lower but may see remnants of this activity drift into
northeast lower during late afternoon. Will make some adjustments
to precipitation timing but looks like approaching post-frontal rain
band and pre-frontal convective development will result in
precipitation "filling-in" during the afternoon. A decent though
quick-hitting shot of rainfall expected with a nice push of 1.25
inch precipitable water values (about 2 standard deviations above
the mean and more than 200 percent above normal)...a tight
baroclinic zone and right rear quadrant jet forcing should be able
to squeeze out 0.50+ inch of rain in spots. Frontal rain band
expected to sweep into Lake Huron by the pre-dawn hours of
Thursday...but with 850mb temperatures plunging below zero some
northwest flow lake induced rain showers will be developing in its
wake heading into Thursday.
Precipitation along the leading edge of the frontal rain band...or
any pre-frontal convective development...may be accompanied by gusty
winds. There will be gusty "synoptic" winds associated with the
cold front...both ahead of the front with fairly deep mixing...and
right behind the front aided by tight isallobaric component. Gusts
ahead of the front likely over 30 mph...and at least that if briefly
not more with cold front passage.
Scattered lake induced rain showers should be ongoing Thursday
morning. Consensus PoP forecast was a bit dry so blended in SREF
PoPs in order to get the idea in the forecast. Boundary layer
should still be warm/deep enough to keep precipitation all rain
(with lake temperatures still at or above 15c...typically takes
850mb temperatures of at least -6C for snow across the interior...
and around -9c near the lakeshores). Precip coverage expected to
wane during the afternoon as high pressure/anticyclonic flow build
in. Temperatures a good 20 degrees below Wednesday highs with many
areas seeing temperatures remain in the 40s.
No weather impacts Friday...Saturday could be breezy while rain
chances expected to ramp up again Saturday night/Sunday. Mild
temperatures expected Saturday through Monday.
&&
.AVIATION...(For the 12Z TAFS through 12Z Wednesday morning)
Issued at 646 AM EDT Tue Oct 11 2016
VFR. LLWS early this morning, and again at MBL tonight.
Plenty of mid-level clouds out there today, as warmer and somewhat
more moist air enters the region. A few sprinkles can not be ruled
out, especially this morning, at MBL/TVC/PLN. But cigs/vsbys will
remain comfortably VFR. Clouds will thin out tonight.
Winds will be southerly, up to around 10kt. Early-morning LLWS
will last til 14Z or so. LLWS returns tonight at MBL, and is
marginal at the other sites.
&&
.MARINE...
Issued at 330 AM EDT Tue Oct 11 2016
Breezy southerly winds will continue until Wednesday, when a sharp
cold front will slowly move across northern MI from midday thru
early evening. Those initial southerly winds and a long fetch
will result in small craft advisory conditions on Lake MI and
Whitefish Bay. Marine headlines will become more widespread on Wed
and Wed night, with gusty nw to n winds behind the front.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...SMALL CRAFT ADVISORY until 8 AM EDT Thursday for LMZ323-341-342-
344>346.
LS...SMALL CRAFT ADVISORY until 8 AM EDT Thursday for LSZ321.
&&
$$
UPDATE...Sullivan
SHORT TERM...JZ
LONG TERM...JPB
AVIATION...JZ
MARINE...JZ
Area Forecast Discussion
National Weather Service Bismarck ND
913 AM CDT Tue Oct 11 2016
.UPDATE...
Issued at 855 AM CDT Tue Oct 11 2016
Previous forecast remains on track. The question remains to be
where the line of frontogenesis sets up. The latest HRRR runs push
the heaviest band of precipitation a bit further south into Slope
and Bowman counties. However, with the lack of radar coverage
where precipitation currently is and the Bismarck radar down for
maintenance initialization is expected to be a bit off. Thus have
kept the placement of the area of one to three inches of snow in
line with where the 12 UTC run of the NAM places the mid level
frontogenesis.
UPDATE Issued at 630 AM CDT Tue Oct 11 2016
Regional radars show precipitation lining up across eastern
Montana and will continue to develop into west Central North
Dakota this morning. Precipitation types this morning will
encompass the possibility of freezing rain...rain and snow,
eventually settling down to rain or snow as temperatures rise
above freezing late this morning. Will add some slight chance
rain across the east central following the latest radar trends.
Otherwise current forecast ok.
&&
.SHORT TERM...(Today and tonight)
Issued at 316 AM CDT Tue Oct 11 2016
The main focus for the short term is accumulating snow chances
west.
Early this morning a narrow band of snow has developed across
northwest North Dakota in association with 700 mb frontogenetical
forcing and an upper level jet. This narrow band of snow is
forecast to further develop this morning as an upper level trough
swings through the Northern Plains.
Short-term high-resolution models depict an area across west
central North Dakota of one to three inches of snow accumulation
with ensembles ranging from near zero snowfall to as much as 6
inches. Locations and amounts are always tricky when it comes to
mesoscale bands, but today`s forecast is especially tricky due to
temperatures remaining right near the freezing threshold. If a
mesoscale band sets up over an area for several hours this
morning, accumulations are likely.
For this forecast a blend of ensemble and deterministic guidance
was used. This yielded an area of one to three inches of snow for
Golden Valley, Billings, northwest Stark, Dunn and southern
McKenzie Counties. However, warm road surfaces should limit travel
impacts and keep the bulk of the accumulation to grassy surfaces.
Due to this fact we elected to forgo issuing any winter headlines
for this event. If later model runs show an increase in snowfall
amounts and dynamic cooling a winter weather advisory may be
warranted.
Further east across central North Dakota a mix of rain and snow is
expected with warmer temperatures in the upper 30s to low 40s.
Precipitation should come to an end from west to east this
evening.
.LONG TERM...(Wednesday through Monday)
Issued at 316 AM CDT Tue Oct 11 2016
Quiet and mild weather will highlight the long term forecast.
Temperatures will climb into the 60s by Friday. A cold front may
swing through Saturday morning. At this time only a minor drop in
temperatures is forecast as models keep the area dry as the front
passes. A more robust shortwave may impact the area Sunday into
Monday and bring chances rain.
&&
.AVIATION...(For the 12Z TAFS through 12Z Wednesday morning)
Issued at 630 AM CDT Tue Oct 11 2016
Widespread MVFR ceilings from northwest into central North Dakota
will accompany Rain and snow spreading from southwest into central
North Dakota after 15z Tuesday. Areas IFR ceilings and vsbys in
rain and snow KDIK-KBIS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...MM
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...WAA
Area Forecast Discussion
National Weather Service Houston/Galveston TX
928 AM CDT Tue Oct 11 2016
.UPDATE...
Previous forecast appears to be pretty much on track. A plume of
moisture over SE Texas will bring showers and thunderstorms along
with mostly cloudy skies to most of the area today. Showers so far
this morning have generally been moving along and east of the I-45
corridor, but shower and thunderstorm activity is expected to
shift slightly westward later this afternoon. High temperatures
for today are forecast in the 80s. 11
&&
.PREV DISCUSSION... /ISSUED /
AVIATION...
MVFR ceilings have developed across the area this morning along with
some RA/SHRA generally between IAH and GLS and then off the coast.
Activity is spreading to the north and northwest, and expect this
trend to continue during the day today with a gradual shift of the
best moisture axis westward as the afternoon progresses. 12Z TAFs
have VCSH for much of the morning and afternoon hours, and suspect
some TAF amending will occur today especially when SHRA (and possible
TSRA) get close. SHRA/TSRA decrease later this afternoon and this
evening, and then some sites might see some low clouds and fog develop
tonight through early Wednesday morning. Not confident enough at this
time to mention any of this in the TAFs. 42
PREV DISCUSSION... /ISSUED /
DISCUSSION...
The most notable weather driver for the next week or so should be
a high pressure ridge aloft, but periodically interrupted by upper
troughs to the north for a few chances for scattered showers or
storms. The best potential for rain may come today, but there will
be another chance Thursday/Friday along with a weakening front.
Today through Wednesday night...
After a very dry stretch, precipitable water is in the process of
surging into the area thanks to onshore flow. Precipitable water,
which had been well below an inch, shows a moist tongue over our
Gulf waters right around 1.5 inches. In that region, radar shows
several showers popping up over the Gulf waters, and have even
begun to impinge on coastal areas both along the Louisiana border
and in Brazoria County. Would expect coastal areas to see
potential for isolated to widely scattered showers through the
morning. As the day brings further heating, moisture improves, and
support for vertical motion may be boosted by subtle vorticity
advection associated with a trough lifting towards the Great
Lakes, scattered showers and some storms should be expected even
farther inland. This shows up pretty well in CAMs such as recent
hours of the HRRR and the TTU WRF model. Both of these are
actually pretty aggressive with convection, and push showers well
inland even this morning, so I`ve nudged early PoPs up, but
still think it will take longer for the column to moisturize than
shown in these model runs.
After today, ridging aloft should reassert itself, so Wednesday
should be drier and warmer, with many locations pushing into the
upper 80s to around 90 degrees. There may be scattered spots that
see heat indices near 100 degrees to go along with that, but
should be very localized with most looking to max out in the mid
90s.
Thursday through Saturday...
Midlevel heights look to come down a touch Thursday, which could
allow for a bit of an increase in convection, but the better
chance would be associated as a cold front moves into Texas. The
GFS is a bit faster, which would further bolster potential on
Thursday, while the Euro is a bit slower and focuses more on
Friday (for what it`s worth, the NAM comes in between, shading
more towards the GFS on timing, but more like the Euro on strength).
The globals are much more pessimistic about this front`s
potential, looking like it washes out before pushing too far into
SE Texas and keeping best rainfall potential to our northwest. The
Euro and NAM seem to provide enough instability aloft with the
shortwave a bit deeper, but not strong enough that it could
overcome poor timing (hence the drier Euro). Still, if things line
up right, we could pop up some decent storms...I`m just not buying
that solution right now.
Next week...
The ridge aloft again reasserts itself, and we may again be
looking at temperatures right around 90 degrees for much of the
inland area. Onshore flow continues, which should at least keep
boundary layer moisture up. This won`t make afternoon convection
totally impossible, but would expect isolated showers/storms at
most. Tuesday might have the best shot with a potent trough along
the Canadian border possibly decreasing stability here a bit, but
that`s probably really stretching the potential there. It`s beyond
the scope of this forecast, but both the GFS and Euro seem to be
fans of digging a pretty significant upper trough next week,
moving into Texas late. However, the NAEFS mean is decidedly
unimpressed with near-average height fields, so while it`s fun to
drift to the next big deviation from the current dull pattern,
let`s not get carried away with this idea just yet.
25
MARINE...
Small craft exercise caution flags are up across the eastern waters
for elevated winds as a wave and associated showers and/or
thunderstorms moves across the area. Look for lowering winds tonight
and on into Wednesday with this light to moderate onshore flow
persisting for the rest of the week and on into the upcoming weekend.
If the current forecast holds, the area`s next cold front doesn`t
arrive until the middle to end of next week. 42
&&
.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL) 85 71 89 70 85 / 20 10 20 10 20
Houston (IAH) 83 71 87 71 88 / 60 10 10 10 10
Galveston (GLS) 83 76 85 77 85 / 60 20 10 10 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION until 7 PM CDT this evening
FOR THE FOLLOWING ZONES: Coastal waters from High Island to
Freeport out 20 NM...Waters from High Island to Freeport
from 20 to 60 NM.
&&
$$
Discussion...11
Area Forecast Discussion
National Weather Service Blacksburg VA
1136 AM EDT Tue Oct 11 2016
.SYNOPSIS...
A large area of high pressure will continue to drift slowly east
across the region through Wednesday. A cold front from the Ohio
Valley will move through the region Thursday. Another large area
of high pressure will build back into the area behind this front
and remain in place until a weak disturbance arrives from the
Tennessee Valley late in the weekend.
&&
.NEAR TERM /THROUGH TONIGHT/...
As of 1120 AM EDT Tuesday...
Looking at a dry seasonal afternoon with mostly sunny skies. Just
a few high clouds to keep the sky from being 100 percent clear,
especially across the northern CWA. Temperatures look in track to
reach the mid 60s to around 70 for much of the region.
Previous valid discussion...
High pressure will drift to along the northern Mid-Atlantic coast
by evening, but ridge southwest into the Mid-south and southeast
states as well. Surface winds will veer more to the northeast and
east through the day.
Patchy frost in spots Wednesday morning possible as high clouds
decrease overnight. Not enough coverage to entertain another Frost
Advisory for Wed morning at this point.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY NIGHT/...
As of 210 AM EDT Tuesday...
A ridge of high pressure will remain situated along the lee of the
Appalachians through at least Wednesday night. Anticipate a
continuation of rain free days with limited cloud cover.
Temperatures will remain near or slightly above normal.
On Thursday, a cold front is forecast to try to make progress into
and through the ridge. Guidance has the focus for the best forcing
from roughly Pennsylvania and points north. South into our region,
forcing will be limited, and so will be the associated moisture. The
impact for our region will be primarily an increase in cloud cover
mainly across the mountains and isolated showers mainly over
southeast West Virginia and neighboring portions of southwest
Virginia near the Interstate 64 corridor. Temperatures will inch a
little higher by Thursday with readings about five degrees above
normal.
By Thursday night into Friday, high pressure is back in control of
our weather pattern with a return of dry conditions across the
entire region. Temperatures will cool to readings near normal by
Friday.
For several days now, guidance has been offering a solution that
brings a southern stream shortwave trough out of the Arklatex region
and into our region late Friday night into Saturday. The latest
rendition has trended a bit slower on arrival. Our forecast will
follow suit and offer only a slight chance of showers late Friday
night across the far southwestern portions of the region.
&&
.LONG TERM /SATURDAY THROUGH MONDAY/...
As of 345 AM EDT Tuesday...
Still a mainly dry and just above seasonal temp forecast overall.
Exception will be Saturday as a warm front moves across the Mid
Mississippi Valley into the Ohio Valley. Models showing some return
moisture and lift across a wedge front into our area. Will see how
deep this moisture is but think a chance of showers is worth mention
mainly over the mountains with less threat in the east.
Saturday will see more cloud cover and east to southeast flow.
Anticipate highs cooler in the wedge from the upper 50s to lower
60s, roughly from Greenbrier County WV to the New River Valley and
Roanoke, east to Danville and Lynchburg. Places like Bluefield to
Marion and west will be milder with upper 60s to lower 70s.
High pressure stays in place Sunday-Monday. However, some upper
level energy is progged to move across during this time, and may
bring an isolated shower to the mountains. Overall, looks to become
milder at night with lows in the 50s, while temperatures during the
day reach the lower to mid 70s.
&&
.AVIATION /16Z TUESDAY THROUGH SATURDAY/...
As of 740 AM EDT Tuesday...
Generally VFR conditions expected through the TAF valid period. A
large surface high continues to drift slowly east across the
region and by evening should be aligned near the eastern seaboard.
North to north-northwest winds early will become northeast through
the morning. The low and mid-level air mass will remain very dry,
but cirrus associated with an upper trough moving through the
Midwest will spread across the region today, especially the
northwest half. Cirrus could become BKN at times, then diminish
some overnight as the disturbance moves further away from the
area.
Only a very brief MVFR was noted at KLWB just before daybreak. At
this point, fog this morning appears unlikely, but given T near
Td, a brief MVFR at KLWB or KBCB cannot totally be ruled out.
Given an increasing pressure gradient and stronger northeast wind
flow along with a continued dry air mass, will not forecast fog at
this point for Wed morning. Will likely have to consider with
later TAFs.
Winds mostly northeast 4-8kts through the period, after 14Z. HRRR
suggests that winds could become a little stronger than earlier
thought across southeast WV during the afternoon/evening and veer
more to the southeast.
High confidence in VFR cigs throughout the TAF valid period.
Medium to high confidence in vsbys through 13Z, then high
confidence in VFR vsbys.
Medium to high confidence in wind speed/direction throughout the
TAF valid period.
Extended aviation discussion...
May see a period of sub-VFR upslope cigs behind a passing weak
cold front at KBLF/KLWB by Thursday night, otherwise should stay
VFR through the week. This is outside of any late night/early
morning fog across the valley locations. However with dry air in
place for much of the week, have less confidence on seeing very much
fog at this point. Slightly better potential for MVFR conditions
and possible showers late in the weekend.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...None.
NC...None.
WV...None.
&&
$$
SYNOPSIS...RAB
NEAR TERM...RAB/WP
SHORT TERM...DS
LONG TERM...WP
AVIATION...RAB
Area Forecast Discussion
National Weather Service Sioux Falls SD
334 PM CDT Tue Oct 11 2016
.SHORT TERM...(This evening through Wednesday)
Issued at 334 PM CDT Tue Oct 11 2016
The initial band of scattered sprinkles/light showers should push on
east this evening, and it is tempting to drop pops below mention
levels for a few hours, mainly late evening in the east, but both
HRRR models continue to hint at some spotty light rain appearing
ahead of the main band developing in the Huron to Gregory area
toward midnight. This band is handled with pretty good agreement by
models. There are some differences in timing, likely due to the
strong and fast push east the band should develop later tonight as
it moves across the area. But that this band will be moving across
is in no question, with strong support from a mid level jet that
sweeps across with the progressive wave. This will end the
precipitation quickly from the west after 07Z or so and into the
morning for northwest Iowa. While amounts will be fairly tame,
probably a tenth of an inch or less generally, I could see areas of
a bit greater rainfall, not not much more due to the fast movement.
Continued influx of colder air will make the air aloft cold enough
for a little snow before the precipitation ends north and west of
Sioux Falls, though no accumulations expected due to the stubborn
relatively warm near surface layer. Low temperatures tonight will be
in the mid 30s north and west of Sioux Falls, ranging to the lower
40s in northwest Iowa.
Continued fast movement of the wave will clear skies out quickly
from the west Wednesday, with lingering light rain unlikely to last
past mid morning. A band of cumulus may persist for a bit into the
early to mid afternoon before strong drying eats that up. It will be
chilly with highs in the mid 40s to near 50. A northwest breezy will
add a bit to the chill, although with the fast movement of the upper
system and also the surface high quickly arriving, the wind is
expected to stay below the breezy category.
.LONG TERM...(Wednesday night through Tuesday)
Issued at 334 PM CDT Tue Oct 11 2016
Cold northerly wind flow will start moving through, as a high
pressure system settle into the area Wednesday night. With clear
skies and light winds throughout the night, looks like Wednesday
night will be the coolest night of the season, thus far. Low
temperatures are expected to dip into the upper 20s across most
areas to lows 30s in south central South Dakota. Given that low
temperatures will remain below freezing for several hours, decided
to issue a freeze watch through Thursday 15Z. With the surface high
sliding off to the southeast fairly quickly, there is some concern
that return flow developing in south central SD may move in quickly
enough that temperatures stay above freezing in Gregory county and
surrounding areas. But considering that there may be some pockets
that drop below 32, will go ahead and place them in the watch.
A gradual warming trend will be in place by the end of the work week
with ridging building over the region. Thursday`s highs are expected
in the mid to upper 50s east of the James River to the 60s west.
This warming trend will continue on Friday with highs from the 60s
to near 80s. It will be a windy day, though with southerly winds
from 15 to 25 mph and gusting to around 35 mph, mainly north of I-
90. After a cold Wednesday night, milder nights will return with
lows in the 40s on Thursday night and in the 50s on Friday night.
Unsettled weather possible Saturday morning, as a cold front moves
into the area. Higher rain chances will fall across our far east,
where there are plenty of forcing and dynamics, along with strong
moisture due to southerly low level flow.
Models are consistent in pointing out a few disturbances moving
through the area next week. Strong low pressure system will be
increasing rain chances, possible thunder Monday night into Tuesday
evening.
&&
.AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon)
Issued at 1234 PM CDT Tue Oct 11 2016
Widespread ceilings 1-3k feet. Until 11/20z, areas of ceilings
below 1k feet east of HON/MHE/PKS line. Ceilings improving to 3-5k
feet HON/MHE/PKS and west after 12/06z with clearing that area
after 12/15z. Areas visibility 3-5sm in -RABR moving east across
the area 12/05z/15z. Brief and local visibilities 1-3sm -RASN
north and wets of FSD 12/05z-12z.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...Freeze Watch from late Wednesday night through Thursday morning
for SDZ038>040-050-052>071.
MN...Freeze Watch from late Wednesday night through Thursday morning
for MNZ071-072-080-081-089-090-097-098.
IA...Freeze Watch from late Wednesday night through Thursday morning
for IAZ001>003-012>014-020>022-031-032.
NE...Freeze Watch from late Wednesday night through Thursday morning
for NEZ013-014.
&&
$$
SHORT TERM...
LONG TERM.../JM5
AVIATION...
Area Forecast Discussion
National Weather Service Goodland KS
505 PM MDT Tue Oct 11 2016
.SHORT TERM...(This evening through Wednesday)
Issued at 1231 PM MDT Tue Oct 11 2016
18Z Water Vapor imagery and RUC analysis indicated large H5 trough
over the northern Rockies with fairly zonal flow across western
Kansas and eastern Colorado. At the sfc...initial surge of cold
air behind cold front has pushed across much of the area...with
persistent cold air advection across much of the area holding
temps back much more than previously expected.
Main forecast impacts/concerns will be timing of precipitation
tonight...followed by timing and impact of strong cold front
tonight.
Pocket of low static stability in place tonight as strong cold
front sweeps across the area around 6z. Forcing aloft rather
disorganized...but with strong period of forcing along frontal
zone and pocket of weak static stability expect a few showers to
develop. However...cloud bases remain fairly high where forcing is
maximized...so have some doubts that precipitation will be much
more than a sprinkle in most areas. As front dives south...winds
will increase to around 25 mph as it passes with a rather thick
low stratus deck spreading over the area. Besides aviation
impacts...this should help offset how cold things get by limiting
radiational cooling. By tomorrow morning...sfc high settling over
the area bringing strong subsidence/clearing skies and cooler
temperatures.
.LONG TERM...(Wednesday night through Tuesday)
Issued at 212 PM MDT Tue Oct 11 2016
For this extended forecast period, little in the way of hazardous
weather is forecast. The primary weather concern is the potential
for a frost or a light freeze tomorrow night into Thursday morning.
A cold front has moved into the forecast area today and a surge of
much colder air will move through later tonight. This colder air,
combined with mostly clear skies and light winds forecast, should
lead to a widespread frost across portions of the area Wednesday
night/Thursday morning. For this reason, decided to go ahead with a
frost advisory for this period. Did not consider a hard freeze
watch/warning (temps less than 28 degrees) due to criteria
differences with neighboring offices and low confidence a hard
freeze will occur. It would not surprise me if a few low spots
dipped into the upper 20s but was not confident enough to forecast
that at this time.
Beyond tomorrow night, a warming trend will begin across the High
Plains. Thursday`s highs should rise into the low 60s to low 70s.
Above normal temperatures return Friday, lasting through the weekend
with many locations climbing into the 80s each day.
Upper level disturbances should force a couple cold fronts south
across the Great Plains next week. According to latest guidance,
frontal passages should occur during the day Monday and again
Wednesday. Cooler weather can be anticipated behind each front,
particularly following Wednesday`s front. Will need to monitor
trends as the coldest air of the year, and potentially a widespread
freeze, may be possible behind the second front.
&&
.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 505 PM MDT Tue Oct 11 2016
KGLD, vfr conditions expected from taf issuance through 04z with
winds from the east 10kts or less. Could see some rain showers
near/over the terminal as well. From 05z-17z winds shift to the
northeast with gusts near 30kts possible as a cold front moves
through. Cigs lower into the mvfr category. After 18z cigs improve
to vfr with winds beginning from the northeast near 11kts then
veering to the east around 6kts by 23z.
KMCK, vfr conditions expected from taf issuance through 07z. Winds
begin the period from the east near 5kts becoming northeast and
gusting near 20kts by 03z then near 25kts by 06z. From 08z-17z
winds remain gusty from the north with mvfr cigs expected. A few
showers also possible. At 18z winds from the north around 11kts
becoming northeast near 5kts by 23z with vfr conditions returning.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...Frost Advisory from 1 AM to 10 AM CDT Thursday for KSZ002>004-
015-016.
CO...NONE.
NE...Frost Advisory from midnight MDT /1 AM CDT/ Wednesday night to 9
AM MDT /10 AM CDT/ Thursday for NEZ079>081.
&&
$$
SHORT TERM...JRM
LONG TERM...RRH
AVIATION...99
Area Forecast Discussion
National Weather Service Lincoln IL
303 PM CDT TUE OCT 11 2016
.SHORT TERM...(This evening through Wednesday)
ISSUED AT 250 PM CDT Tue Oct 11 2016
19z/2pm surface analysis shows sprawling ridge of high pressure
extending from New England to the Gulf Coast...while cold front
extends from Lake Superior southwestward to Nebraska. The pressure
gradient between these two features has tightened sufficiently to
produce gusty southwesterly winds across central Illinois this
afternoon. With southwesterly flow continuing tonight, low
temperatures will be several degrees warmer than in recent
nights...with readings remaining in the upper 50s to around 60
degrees. While airmass will initially be quite dry, most models
suggest decent mid-level moistening overnight as a 30-35kt 850mb jet
streak develops ahead of the approaching front. This will result in
increasing cloudiness and perhaps a few showers. Based on latest
HRRR and WRF-ARW, have included low chance PoPs for showers/thunder
along/northwest of a Danville to Shelbyville line after midnight.
As cold front pushes further eastward, showers and thunderstorms
will become more numerous across the entire area on Wednesday. Deep
layer moisture will be increasing substantially...with surface
dewpoints progged to reach the 60-65F range and NAM precipitable
water values climbing to around 1.50. Given ample moisture, strong
convergence along the front, and an upper wave digging into the
region, have gone with likely to categorical PoPs. Latest SPC Day 2
convective outlook still suggests a marginal risk for severe storms
across portions of central Illinois, although it appears both
instability and shear will be limited. Latest data suggests a
narrow corridor of SBCAPES of around 1000J/kg and 0-6km bulk shear
values of 30-35kt. This may be enough to trigger a few strong
storms with gusty winds. Storm initiation on most of the high-res
models is generally along/east of I-55...with the primary time frame
for potential strong storms from about 1 pm through 7 pm.
&&
.LONG TERM...(Wednesday night through Tuesday)
ISSUED AT 250 PM CDT Tue Oct 11 2016
The cold front should be progressing off to our east Wednesday night
with the showers and thunderstorms ending quickly from northwest to
southeast with showers linger into the early morning hours over far
southeast Illinois. Much cooler and drier air will filter into the
forecast area late Wednesday night into Thursday morning with the
potential for some patchy frost over our far northwest counties as
early morning lows drop into the mid 30s around Galesburg to the
upper 40s over extreme southeast Illinois.
Quiet weather then settles over the forecast area for Thursday into
Thursday evening as high pressure tracks across the region. Afternoon
temperatures on Thursday will be quite a bit cooler with readings in
the upper 50s to lower 60s. A shortwave embedded in the southern
stream will track well south of our area Thursday night into Friday
with the better rain chances staying south of the forecast area with
temperatures edging back into the 60s Friday afternoon. Southerly
winds will increase ahead of our next weather system on Saturday
which should help push temperatures well above normal again with
most areas forecast to soar well into the 70s. Another frontal
system will approach the area Saturday night into Sunday bringing
with it the threat for scattered showers and thunderstorms to the
area, with the threat for showers holding into Sunday as afternoon
temperatures climb well into the 70s.
As we head into next week, quite a bit of model variability with
respect to shortwave energy racing east and then either amplifying
into a deep 500 mb wave and surface system depicted on the GFS, or
a much flatter flow aloft seen on the 12z ECMWF. Both patterns bring
unseasonably warm temperatures into the Midwest with afternoon
temperatures Monday around 80 with readings on Tuesday in the 75 to
80 degree range. However, confidence not that great with respect to
timing of showers and storms into the area during this time frame.
Model blend suggests the better rain chances Monday night into
Tuesday, but that will be subject to change with the strong flow
forecast over the eastern Pacific into the Western U.S. early
next week.
&&
.AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon)
Issued at 1244 PM CDT Tue Oct 11 2016
Patches of mid/high clouds persist across central Illinois early
this afternoon, although latest satellite imagery is showing
clearing skies upstream across Missouri. Forecast soundings show
moist layer at around 10-12k ft drying as the day progresses,
leading to mostly clear conditions by late afternoon into the
evening. Warm advection increases overnight as 30-35kt low-level
jet develops ahead of an approaching cold front. Many high-res
models are hinting at scattered showers after 06z...so have
included a mid-level cloud deck and VCSH at all terminals
overnight. Cold front is progged to push into the Illinois River
Vally by late Wednesday morning, with most of the convection
developing after 18z along/east of the I-55 corridor. Based on NAM
forecast soundings, have lowered ceilings to low VFR and carried
predominant SHRA with VCTS at KPIA after 16z. Think potential
MVFR ceilings and widespread thunder will hold off until after 18z
Wed.
&&
.ILX Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...Barnes
LONG TERM...Smith
AVIATION...Barnes
Area Forecast Discussion
National Weather Service Marquette MI
424 PM EDT Tue Oct 11 2016
.SHORT TERM...(This evening through Wednesday)
Issued at 358 PM EDT TUE OCT 11 2016
Latest water vapor loop and RAP analysis shows a shortwave lobe
moving through the Upper Great Lakes and this shortwave and assoc q-
vector convergence and isentropic ascent ahead of it was still
supporting an area of showers over mainly the east half of Upper Mi
at 19Z. Models show this area of showers weakening and moving east
of the area by early evening with exiting shortwave.
Focus then shifts to approaching cold front over MN which is
forecast to move across the area late tonight into Wed morning.
Models indicate that the strong shortwave over MT will ride up
backside of front and favorable jet dynamics with upper divergence
in right entrance region of 120-130 kt 250-300 mb jet max along with
assoc strong mid-level fgen forcing will result in several hour
period of post-frontal rain showers moving through the forecast
area. Showers will move into far western counties late tonight and
then spread quickly eastward through the day on Wednesday. Will
maintain categorical pops on Wednesday given strong dynamics
depicted behind the front. Showers are expected to diminish from the
west in the afternoon with strong mid-level drying expected. With
pwat values into the 1.0-1.25 inch range and strength of the large
scale forcing, pcpn amounts up to 0.50 inch are likely. Northwest
winds will be gusty behind the front on Wed with highest gusts up to
30 mph possible along Lake Superior shore east of MQT.
.LONG TERM...(Wednesday night through Tuesday)
Issued at 423 PM EDT TUE OCT 11 2016
Prominent 500mb height anomaly currently over AK of 3 standard
deviations above long term climatology is fcst to retrograde to far
eastern Siberia and then weaken over the next week. As this occurs,
the W Coast ridge will collapse as a trof and negative height
anomaly centered just s of the Aleutians shift e and set up shop
over the ne Pacific thru this weekend. The deep trof setting up just
off the W Coast is warm signal for the Great Lakes as wsw/sw flow is
forced downstream. So, after a cool down back to a little blo normal
occurs into Thu in the wake of a trof passing across the area on
Wed, temps will rebound back to above normal by Sat. Although a
shortwave will pass across the area late Sat/early Sun, a Pacific
air mass will follow, resulting in little or no cooling for Sun.
Medium range guidance is in agreement showing stronger shortwave
energy ejecting from the ne Pacific trof and reaching the Great
Lakes region early next week, but timing is very uncertain. However,
it appears above normal temps will continue at least thru Mon.
Looking farther ahead, CPC/NAEFS outlooks indicate pattern will
continue to favor above normal temps overall into late month with
flow off the Pacific largely dominating. Any periods of blo normal
temps will likely be short lived. As for pcpn over the next 7 days,
after shra Wed and some lake effect pcpn into early Thu, dry weather
should be the rule into early Sat. Shortwave passing late Sat into
early Sun will bring the next round of shra. More shra are expected
early next week with a couple of additional shortwaves.
Beginning Wed night/Thu...850 mb temps dropping to -5 to -6C along
with water temps in the 10C-13C range will provide enough
instability for some lake effect pcpn for mainly nw flow favored
locations Wed night, especially during the evening over the e due to
better low-level convergence and inversion up to around 7kft.
However, with fcst soundings showing an increasingly well-mixed
boundary layer, especially pronounced on GFS fcst soundings, lake
effect pcpn will be limited across the area. Coverage will be
greatest into the eastern fcst area where longer fetch will work to
diminish the well-mixed layer. Wet-bulb zero height suggest snow may
be possible over the west half but with the moist layer mainly blo
-8C, little ice will be available for snow potential. No snow
accumulation expected. Slowly backing winds with developing waa will
bring gradual clearing on Thu from wsw to ene. Expect high temps
in the upper 40s/lwr 50s.
Sw flow into the Great Lakes strengthens on Fri as troffing expands
into the western CONUS. 850mb temps are fcst to rise to 5-8C by the
end of the aftn. Under mostly sunny skies, only dimmed by some high
clouds, expect max temps to reach the mid/upper 50s, perhaps 60F at
downslope locations. Tightening pres gradient will result in
strengthening low-level wind fields. With building mixed layer
tapping winds of 25kt or so, it will become a breezy day with gusts
into the 20-30mph range.
Shortwave ejecting from the trof over the ne Pacific/western CONUS
will reach the area Sat night/Sun morning. There are sufficient
differences among the models with where best forcing will occur to
favor a general consensus of current/recent model runs for
constructing pops. Shra chances will increase Sat aftn with a period
of likely pops mainly during Sat evening. Dry/warm weather will then
follow on Sun under mostly sunny skies. Low to mid 60s expected for
max temps Sat and Sun, but areas that see downsloping with a w wind
may reach the upper 60s on Sun.
Mon/Tue...there is good agreement that a weaker shortwave ejecting
out of the western trof will bring shra back to the area Sun night
into Mon morning. The GFS then becomes slower/stronger with the next
shortwave as it develops a strong low pres system that reaches the
Upper Lakes late Tue. There is not much support from GFS/Canadian
ensembles for a strong low pres, so the operational GFS is an
outlier at this point. For now, fcst will show a return of chc
pops on Tue, but low confidence.
&&
.AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon)
Issued at 134 PM EDT TUE OCT 11 2016
Scattered showers will move east of SAW in the next few hours so have
kept a mention of VCSH in SAW through 20Z. Low-level moisture and
MVFR clouds should also lift out of the TAF sites by late afternoon
with conditions improving to VFR. A cold front will move through
CMX and IWD late tonight and through SAW by late Wed morning,
followed by rain and gusty NW winds. CIGs will reduce to IFR to low
MVFR behind the front with lowest cigs at KCMX and KIWD in developing
upslope NW flow.
&&
.MARINE...(For the 4 PM Lake Superior forecast issuance)
Issued at 358 PM EDT TUE OCT 11 2016
Southwest winds will generally be less than 20 knots through
tonight, but as a potent cold front crosses Lake Superior late
tonight into Wednesday morning, strong cold advection will ensue
behind the front as northwest winds increase to 20 to 30 knots
Wednesday afternoon into the evening over Lake Superior, strongest
over the eastern half. Southerly wind winds ahead of another
approaching system for the upcoming weekend may gust to 30 knots
Friday afternoon through Saturday evening.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
None.
Lake Michigan...
None.
&&
$$
SHORT TERM...Voss
LONG TERM...Rolfson
AVIATION...Voss
MARINE...Voss
Area Forecast Discussion...UPDATED
National Weather Service Norman OK
524 PM CDT TUE OCT 11 2016
.UPDATE...
Increased rain chances and sky cover this evening across northern
Oklahoma.
&&
.DISCUSSION...
Some strong storms with gusty winds as the main hazard may impact
northern Oklahoma this evening (7 pm-midnight).
Made the changes above based on latest radar trends and HRRR
guidance. Ongoing weak high-based showers and storms over the
Oklahoma Panhandle will continue to rapidly move east during the
next few hours. This activity may grow in size and intensity
around 7 pm as it move into northwestern Oklahoma where the air is
more unstable (MUCAPE 1000-2100 J/kg) and where deeper low level
moisture exists with surface dewpoints in the upper 50s and lower
60s. Not to mention, the low level jet will be increasing.
Additionally, light echoes near Woodward and Arnett as of 520 pm
may grow upscale as well.
Steep low and mid level lapse rates suggest that strong winds may
be the main hazard with these storms if they grow in coverage and
intensity. Severe potential remains low, but not zero. Strong
shear (30-55 kt 0-6 km bulk shear) supports multicells and
supercells. Some hail could be possible as well.
For now, increased rain chances into the 20-40% range north of an
Arnett to Fairview to Stillwater line this evening.
There remains quite a bit of uncertainty this evening with storm
coverage, strength, and intensity across northern Oklahoma due to
the lack of large scale lift and the lack of deep moisture.
Products have been updated.
MBS
&&
.PREV DISCUSSION... /issued 225 PM CDT TUE OCT 11 2016/
DISCUSSION...
A cold front will arrive Wednesday around sunrise to northwest
Oklahoma and bring low clouds and gusty north winds along with
drier and cooler air. The front will reach central Oklahoma around
mid-day Wednesday as it continues south of the Red River by early
evening. There is a low probability for a brief period of light
showers and isolated thunder with the front, mostly over north
central and central Oklahoma. Temperatures will fall during the
afternoon over the northern half of the state into the 50s. Rain
and thunderstorm chances increase later Thursday and into Friday
when very warm and moist air moves north over the front stalled
over north Texas. Rainfall amounts are not expected to be as high
as previously thought, but large areas of south central and
southeast Oklahoma could see an inch or so. A strong warming trend
starts later Friday and temperatures by late weekend and early
next week are expected to be around 90 degrees under the influence
of an upper height ridge over southwest Oklahoma and areas to the
south and west while central Oklahoma is expected to be seasonably
hot into the middle 80s.
&&
.PRELIMINARY POINT TEMPS/POPS...
Oklahoma City OK 62 71 48 63 / 10 20 10 50
Hobart OK 62 71 47 61 / 0 10 10 50
Wichita Falls TX 62 80 52 65 / 0 10 10 40
Gage OK 54 59 39 62 / 20 10 10 40
Ponca City OK 61 66 43 63 / 40 20 0 20
Durant OK 65 86 55 71 / 10 0 10 20
&&
.OUN Watches/Warnings/Advisories...
OK...None.
TX...None.
&&
$$
17/26