Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 10/12/16
Area Forecast Discussion
National Weather Service Albany NY
1021 PM EDT Tue Oct 11 2016
.SYNOPSIS...
High pressure will drift east of the region tonight into
Wednesday. Temperatures will rise back above normal into the
midweek, as a cold front will approach for Thursday. The cold
front will bring scattered showers during the afternoon and into
the early evening with a return to more seasonable temperatures to
close the week.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
As of 1000 PM EDT...High and some mid level clouds continue
advancing northeastward per enhanced satellite imagery as average
500-300mb RH fields were greater than 80 percent per RAP hourly
analysis. These clouds will move across most of the region overnight
to partly cloudy then to mostly cloudy sky.
Through the night expect nearly calm winds, perhaps very light
south winds in some areas. Periods of mid and high clouds will
allow for some radiational cooling but no frost or freeze
headlines tonight. Lows in the upper 30s to lower 40s, but some
mid 30s in the southern Adirondacks and in colder areas that had
the growing season end this Tuesday morning.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/...
Mid and high clouds should thin out and exit through the day
Wednesday as south winds increase a little. Some sun and warm
advection should help temperatures to reach the mid to upper 60s.
Some fog should develop in some areas Wednesday night as low level
moisture slowly increases. Clouds will also increase in western
areas as an upper system and associated cold front approach. A few
isolated showers may just reach far western areas by daybreak
Thursday.
Fog may become stratus as it lifts Thursday morning and deeper
moisture approaches through the morning. The upper system looks
like it will track through quickly and lift into eastern Canada
Thursday night. The cold front looks a little frontolytic and low
level flow ahead of the cold front is southwest. This suggests
that coverage of showers associated with the cold front could be
limited. So, indicating likely showers far west and northwest but
just scattered everywhere else. There may only be a narrow band of
scattered showers as suggested by guidance. Highs Thursday in the
mid 60s to around 70 but lower 60s southern Adirondacks.
Any lingering late afternoon or evening showers will end and cold
advection should strengthen through Thursday night and Friday.
Depending on the timing of the cold frontal passage, there may be
some cooling Thursday afternoon in some areas. Sunshine and
cooler temperatures expected Friday with high pressure building
in. Highs Friday in the upper 50s to lower 60s, with lower to mid
50s southern Adirondacks.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
Global model consensus favors a mainly tranquil upcoming weekend
with some discrepancies showing up with respect to Sunday into
Monday forecast.
A fairly large surface high coinciding with building heights aloft
will provide plenty of clear skies Friday night through early
Sunday. As thermal column moderates a couple of degrees each day,
so too will the afternoon high temperatures. Valley temperatures
will climb into the 60s which will be an average of 5 degrees above
normal with near seasonable overnight lows.
The aforementioned discrepancies show up during later Sunday into
Monday. The ECMWF is a bit more aggressive with the approach of the
frontal system with the GFS/GGEM a bit slower hence a drier
forecast. Per the latest blended approach, we will continue with
the chance PoPs mainly west of the Capital District later Sunday
before spread the chance PoPs across the remainder of the region
Sunday Night into Monday. Temperatures should remain rather mild
with H850 temperatures at or above +10c.
Overall temperatures should average above normal with precipitation
below normal.
&&
.AVIATION /23Z TUESDAY THROUGH SUNDAY/...
VFR conditions are expected through the TAF period; 00Z/Thursday.
Ridging across the region at all levels of the atmosphere will
shift eastward and weaken. Mid and high level clouds will stream
over the region. This thin blanket of clouds should be enough to
prevent radiational fog from developing at this time.
Light and variable will become calm this evening with light winds
developing Wednesday morning. A light southerly winds evolves through
the daylight hours Wednesday.
Outlook...
Wednesday Night: No Operational Impact. Patchy FG.
Thursday: Moderate Operational Impact. Scattered SHRA.
Thursday Night through Sunday: No Operational Impact. NO SIG WX.
&&
.FIRE WEATHER...
High pressure will drift east of the region tonight into
Wednesday. Temperatures will rise back above normal into the
midweek, as a cold front will approach for Thursday. The cold
front will bring scattered showers during the afternoon and into
the early evening with a return to more seasonable temperatures to
close the week.
The relative humidity values will recover to 90 to 100 percent
tonight and Wednesday night with frost and dew tonight. The RH
values will fall to 35 to 50 percent Wednesday afternoon and 50 to
75 percent with scattered showers Thursday afternoon.
Winds will be light and variable in direction at 10 mph or less
tonight. Wednesday will feature south to southeast winds at 5 to
15 mph, becoming southwest Thursday.
&&
.HYDROLOGY...
No hydro problems the next 5 days ending Saturday.
Dry weather is expected through Wednesday night. Scattered showers
are expected Thursday with most areas seeing a quarter inch of
rain or less. The higher totals will be over the northern portion
of the HSA.
The latest US Drought Monitor continues to show drought conditions
across much of the region. Precipitation departures this calendar
year have been 3 to 12 inches below normal, with the greatest
departures across southeastern parts of the HSA. As a result,
streamflow and ground water levels have been running well below
normal.
Dry weather returns for Friday into Saturday with high pressure
building back into the region.
For details on specific area rivers and lakes, including observed
and forecast river stages and lake elevations, please visit the
Advanced Hydrologic Prediction Service /AHPS/ graphs on our website.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
MA...None.
VT...None.
&&
$$
SYNOPSIS...NAS
NEAR TERM...BGM/NAS
SHORT TERM...NAS
LONG TERM...BGM
AVIATION...IAA/BGM
FIRE WEATHER...NAS
HYDROLOGY...NAS
Area Forecast Discussion
National Weather Service Sioux Falls SD
1031 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 06Z TAFS through 06Z Wednesday night)
Issued at 1027 PM CDT Tue Oct 11 2016
Light rain will gradually build back into the area overnight as
mid-level forcing moves through. Ceilings along and east of I-29
will bounce between MVFR to VFR at times as a layer of dry air
moves through the area. Further west, KHON may have also bounce
between VFR and high MVFR ceilings through daybreak.
Any precipitation tonight should remain on the light side, moving
east of the area after 14Z. Ceilings will gradually lift through
the morning, with clear skies and light winds by the early
evening.
&&
.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...Dux
Area Forecast Discussion
National Weather Service Lincoln IL
906 PM CDT TUE OCT 11 2016
.UPDATE...
Issued at 906 PM CDT Tue Oct 11 2016
Light showers and isolated thunderstorms have begun to develop
over parts of central IL and northeast MO this evening. HiRes
short term models continue to show this continuing during the
overnight hours, but dissipating toward morning hours. Will be
updating for current radar trends, but will likely keep some small
chances in the grids for the overnight hours. Cells are moving
west to east so will be keeping pcpn north of I-70 overnight.
Remainder of forecast looks ok, but will be taking a look. Updated
grids and forecast will be out shortly.
&&
.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 00Z TAFS through 00Z Wednesday evening)
Issued at 650 PM CDT Tue Oct 11 2016
VFR conditions will begin at all sites this TAF period, with
scattered AC moving into the area currently. Mid level warm air
advection will increase during the evening and all short range
models hint at scattered showers during the overnight hours at all
sites with a mid cloud deck around 7kft. Then during the morning
hours as the frontal system moves into the area, showers and
isolated thunderstorms will effect the sites...beginning at PIA
around 15z, then SPI and BMI around 16z, DEC at 17z, and then last
at CMI at 18z. Vis and cig heights will drop into the MVFR
category due to increasing low level moisture ahead of and along
the front. Around 18z, the threat of thunder at PIA will diminish,
but continue at the other sites during the afternoon hours. MVFR
cig and vis conditions will continue as well but get a little
lower. Will include scattered IFR clouds for the afternoon at all
sites, but may have to become broken in later forecast since it
will be around the front passage. Winds will be southerly tonight
and then become southwest during the morning ahead of the front,
then west to northwest as the front passes tomorrow afternoon.
&&
.ILX Watches/Warnings/Advisories...
NONE.
&&
$$
UPDATE...Auten
SHORT TERM...Barnes
LONG TERM...Smith
AVIATION...Auten
Area Forecast Discussion
National Weather Service Northern Indiana
830 PM EDT Tue Oct 11 2016
.SYNOPSIS...
Issued at 805 PM EDT Tue Oct 11 2016
Southerly flow will continue to support mild conditions tonight
into Wednesday. Lows tonight will be in the 50s with highs on
Wednesday into the 70s. Dry weather will continue tonight with
just a slight chance of showers after daybreak across far
northwest Indiana and southwest lower Michigan. A round of rain
will accompany a cold front late Wednesday into Wednesday night,
with a perhaps a rumble of thunder across Indiana and southern
Michigan mid afternoon through early evening. Cooler and drier
conditions are expected Thursday through Saturday as high pressure
builds in. Sunday into next week will likely trend more active and
mild with periodic chances for rain.
&&
.UPDATE...
Issued at 805 PM EDT Tue Oct 11 2016
Previous forecast is in good shape this evening, with update sent
mainly to refresh late afternoon wording. Low level flow will
veer and strengthen overnight in advance of larger scale trough
moving into the northern Plains. A smaller scale vort max across
north central Iowa will track across the southern Great Lakes
early Wednesday morning. A strengthening low level jet ahead of
this feature will allow low level theta-e ridge to nose into the
area which may provide enough weak elevated instability for a few
isolated showers across the far west/northwest after 09Z. 23Z HRRR
does bring in some showers across the far west after 08Z, but
given initial dry subcloud layer will opt to maintain later timing
from previous forecast closer to the 12Z timeframe.
&&
.SHORT TERM...(This Evening through Wednesday Night)
Issued at 322 PM EDT Tue Oct 11 2016
Temperatures will remain well above normal into tonight and
Wednesday as southwest flow deepens/strengthens in advance of an
upper trough modeled to dig into the north-central US. Spike in mid
level RH/ascent tied to a weak lead/lower amplitude wave lifting
into the northern Great Lakes may generate a few sprinkles or very
light/high based showers into nw IN/lower MI this afternoon into
early this evening. Another weak lead perturbation near CO will get
a kick ene into the lower Great lakes later tonight/Wednesday
morning. Hard to completely rule out a few showers with this feature
into far western IN/sw Lower MI as LLJ and weak elevated instability
on leading edge of height falls fold in, though chances remain
too low for a mentionable PoP in most locations.
A several hour period of rain continues to look more and more likely
into nw IN/lower MI later Wednesday afternoon/evening and points
east into Wednesday night as strong frontal forcing (enhanced by mid
level dcva and upper level divergence associated with the
approaching upper level trough) translates through. Narrow, yet
sufficient, corridor of moisture return and this forcing support
going categorical PoPs and modest QPF. Limited lapse
rates/instability should limit thunder coverage/intensity, though
cannot rule out embedded thunder/locally heavy rain along and west
of I-69 mid afternoon through early evening.
&&
.LONG TERM...(Thursday through Tuesday)
Issued at 322 PM EDT Tue Oct 11 2016
Subsidence/drying/CAA/northwest winds expected in wake of front
Thursday morning as 850 mb temps crash nearly 10 degrees C. Lake-
850mb lake differentials in the mid-upper teens may be enough to
keep low stratocu around a little longer than modeled on Thursday
morning, though expect significant drying to preclude any lake
effect shower activity.
High pressure then builds in later Thursday through Friday night
providing a stretch of cool/quiet weather. Cool airmass and optimal
radiational cooling should provide lows into the mid/upper 30s and
possibly frost Thursday night.
A strong north pacific jet will send several more waves from the
Western US northeast through the Great Lakes region this weekend
into next week. The result will be a somewhat active and mild
pattern with better rain chances Saturday night/Sunday and again
Monday night/Tuesday.
&&
.AVIATION...(For the 00Z TAFS through 00Z Wednesday Evening)
Issued at 805 PM EDT Tue Oct 11 2016
The initial short wave which brought a few sprinkles to northern
Indiana earlier this afternoon has departed to the east. VFR and
dry conditions are expected for the remainder of the night,
although some low end potential may exist for isolated shower at
KSBN after 09Z as southwesterly LLJ ramps up in advance of next
weak short wave. Rain showers are expected to overspread northern
Indiana Wednesday afternoon/evening as larger scale trough kicks
out of the northern Plains allowing a cold front to push eastward.
Cannot rule out isolated thunder at KSBN late Wednesday afternoon,
but instability should be limited and point probabilities appear
too low at this time for thunder inclusion at this forecast
distance. Otherwise, gusty southwest winds in store for Wednesday
afternoon into the 20 to 25 knot range ahead of the cold front.
Have kept KFWA dry this cycle, although rain will overspread
northeast Indiana toward end of this forecast period.
Deteriorating aviation conditions are expected at both terminals
behind the front just after this forecast valid period.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...Small Craft Advisory from 4 PM Wednesday to 4 PM EDT Thursday
for LMZ043-046.
&&
$$
UPDATE...Marsili
SYNOPSIS...Marsili
SHORT TERM...Steinwedel
LONG TERM...Steinwedel
AVIATION...Marsili
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Area Forecast Discussion
National Weather Service Marquette MI
730 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 00Z TAFS through 00Z Wednesday evening)
Issued at 729 PM EDT TUE OCT 11 2016
The arrival of some llvl dry air in the sly flow ahead of a slowly
aprchg cold fnt wl result in VFR conditions thru this evng. But as
this flow taps more llvl mstr just in advance of the fnt, lower cigs
wl arrive and fall into the IFR range right behind the fropa as a a
shallow cool airmass moves into the area in an incrsg nw flow. Gusty
nw winds wl grdly advect drier air into the area, bringing some
improvement late in the TAF period.
&&
.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.
&&
$$
SHORT TERM...Voss
LONG TERM...Rolfson
AVIATION...KC
MARINE...Voss
Area Forecast Discussion
National Weather Service Tulsa OK
835 PM CDT TUE OCT 11 2016
...UPDATE...
.DISCUSSION...
A few showers/thunderstorms have developed across northwest
OK...east of the dryline and south of the approacing cold
front in a ribbon of higher dewpoint air. Recent runs of the
HRRR eventually shift this activity east toward northeast OK
later this evening...with some increase in coverage overnight
as the cold front nears.
Overnight forecast is in reasonable shape...although introduced
some low PoPs the remainder of the evening for the far northwest
portions of the forecast area.
&&
.PRELIMINARY POINT TEMPS/POPS...
TUL 65 70 45 66 / 30 40 10 20
FSM 65 82 57 68 / 10 20 20 20
MLC 68 79 51 67 / 10 20 10 30
BVO 63 68 41 63 / 50 40 10 20
FYV 63 76 47 66 / 10 60 40 20
BYV 64 76 46 63 / 10 60 40 10
MKO 66 75 49 68 / 10 40 10 20
MIO 66 71 44 65 / 40 60 10 10
F10 67 75 48 68 / 10 40 10 30
HHW 66 83 57 71 / 10 10 10 30
&&
.TSA Watches/Warnings/Advisories...
OK...None.
AR...None.
&&
$$
SHORT TERM...18
Area Forecast Discussion
National Weather Service La Crosse WI
336 AM CDT Wed Oct 12 2016
.SHORT TERM...(Today and tonight)
Issued at 336 AM CDT Wed Oct 12 2016
Latest water vapor satellite imagery showing upper level trough
digging over the Northern Plains. 08z surface analysis indicate cold
front extending from over Lake Superior into northern Missouri.
Scattered showers or light rain/drizzle is occurring behind the
front over southern Minnesota and northern Iowa per latest mosaic
radar. This is in response to 850-700mb QG forcing per 12.06z.
Surface cold front pushes east of the forecast area by 18z today.
The deterministic 12.00z GFS/NAM and 12.06z RAP are in decent
agreement in developing showers behind the surface front this
morning...due to 850-700mb QG forcing. With forcing/lift
diminishing/decreasing and exiting the forecast area this afternoon
...the showers will exit the eastern parts of the forecast area
around 21z today.
Colder airmass filters in behind surface front/upper level trough
this afternoon into tonight. The 12.00z GFS/NAM/ECMWF suggest 925mb
temperatures by 12z Thursday to fall to around zero degrees celsius
to plus 2 degrees celsius across the forecast area. With light
winds and clear skies tonight...temperatures will drop into the
middle 20s to around 30 across much of the forecast area and
possibly into the lower 20s in the favored cold locations. Have
issued a Freeze Warning tonight across the forecast area...except
Taylor County in north central Wisconsin.
.LONG TERM...(Thursday through Tuesday)
Issued at 336 AM CDT Wed Oct 12 2016
Upper level shortwave/surface ridge builds into the Great Lakes
Region Thursday into Friday. Subsidence underneath ridge will allow
for dry weather across the forecast area. High temperatures Thursday
will be slightly below normal with highs in the upper 40s to middle
50s. Tighter pressure gradient occurs Friday...as surface ridge
slowly pushes to the east of the forecast area. Breezy conditions
are expected...especially over higher terrain and open areas.
Main forecast concerns Friday night into Tuesday are precipitation
chances through the period. The 12.00z GFS/ECMWF/GEM are in decent
agreement in developing west to southwest flow aloft through Sunday
night...then begin to diverge significantly on strength of
deepening upper level trough over the Rocky Mountains early next
week. The 12.00z GFS deepens upper level trough and closes upper
level low over the Upper Great Lakes Region by 00z
Wednesday...while the 12.00z ECMWF remains west to east zonal flow
across the northern tier United States. The deterministic models
are in agreement moving first shortwave trough to impact the Upper
Great Lakes Region Saturday into Saturday night. This will provide
a chance for showers/thunderstorms across the forecast area...with
subtle timing differences in the shower/thunderstorm chances.
Next concern is deepening upper level trough over the Rocky
Mountains or shortwave troughs embedded in the west to east zonal
flow aloft early next week. With the 12.00z GFS/ECMWF showing
significant differences in the overall flow pattern...confidence in
timing of precipitation chances into the forecast area remains low.
However...the deterministic models indicate an active weather
pattern developing for early next week...with periodic precipitation
chances Monday into Tuesday.
&&
.AVIATION...(For the 06Z TAFS through 06Z Wednesday night)
Issued at 1119 PM CDT Tue Oct 11 2016
MVFR to IFR conditions are expected tonight into Wednesday. Look
for ceilings to lower to 800 ft at KRST and to around 1500 ft at
KLSE. Also, rain showers will overspread the region but should be
on the light side with minimal visibility restrictions to around
6SM expected. Northwest winds will also be on the increase tonight
into Wednesday. Ceilings will rise to VFR Wednesday afternoon and
skies will become clear by Wednesday evening as high pressure
builds into the region.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...Freeze Warning from 2 AM to 9 AM CDT Thursday for WIZ029-032>034-
041>044-053>055-061.
MN...Freeze Warning from 2 AM to 9 AM CDT Thursday for MNZ079-086>088-
094>096.
IA...Freeze Warning from 2 AM to 9 AM CDT Thursday for IAZ008>011-018-
019-029-030.
&&
$$
SHORT TERM...DTJ
LONG TERM...DTJ
AVIATION...WETENKAMP
Area Forecast Discussion
National Weather Service Cleveland OH
603 AM EDT Wed Oct 12 2016
.SYNOPSIS...
High pressure over New England will bring a southerly flow of mild
air to the region Today ahead of a cold front. The cold front
will cross the area Tonight and early Thursday. High pressure and
cooler air will move into the area Thursday night and Friday.
&&
.NEAR TERM /THROUGH TONIGHT/...
Update...Watching showers advance towards the area across northern
Indiana however still feel they will miss the local area to the
northwest so will continue with a dry forecast. Will increase
clouds in the grids to get better resolution in the zones showing
morning debris clouds...then partly cloudy.
Original...Weak short wave energy has helped showers and
thunderstorms to develop and expand across Central and Northern IL
early this morning. Satellite has this complex moving ENE but
while the cloud shield may reach into NWRN Ohio this morning the
HRRR has the precip moving just northwest of the area as it
weakens. A cold front will move east across the area beginning
tonight into early Thursday morning. Clouds will increase from the
west this afternoon as moisture proceeding the system moves into
the area. Will again hold off pops for today.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY NIGHT/...
Update...Will add the mention of patchy frost to the forecast for
areas away from Lake Erie early Friday morning. Otherwise no
changes.
Original...The cold front will move into the area from the WNW
late this evening with guidance now taking the front to a position
just east of the area by 12z Thursday. Will have cat pops for all
areas overnight...lingering into Thursday morning far east. By
afternoon Thursday believe it will be dry everywhere. The rest of
the week should be relatively uneventful with high pressure
building into the area from the west. Saturday both the ecmwf and
gfs show a short wave spreading moisture into the area on the back
side of the high as it exits east. For now will introduce slight
chance pops south for the day Saturday increasing to chance west
and slight chance elsewhere saturday night as another cold front
approaches from the west. Thursday should be the coolest day with
highs 55 to 60. Friday just a few degrees warmer. Saturday mainly
65 to 70.
&&
.LONG TERM /SUNDAY THROUGH TUESDAY/...
The long term forecast begins on Sunday with the first of a pair of
upper level troughs looking to move through the Great Lakes region.
This first trough looks to support a surface cold front which will
bring rain to the area on Sunday and into Monday. This front has
been progged for a couple days now and both models are in fairly
good agreement so have likely pops for the entirety of Sunday and
into the first couple hours of Monday. Temperatures on Sunday look to
be into the 70s, well above normal ahead of this cold front. Behind
this cold front on Monday, a warm front will be quick to move
north and will allow for some rain to linger over the area and
temperatures to not really change. Thus, have left a slight chance
to chance pop in the forecast for Monday and then temperatures to be
above normal again.
For Tuesday and beyond, the models to begin to differ quite a bit on
the evolution of the second upper trough that will begin next week.
The ECMWF brings the next system through fairly quickly on Tuesday,
leaving a dry Wednesday. Whereas, the GFS deepens a surface low,
which would extend a cold front over the area late Tuesday into the
first half of Wednesday, and then drying out the area for
the second half of Wednesday into Thursday. For now, a blend of the
solutions should suffice with a slight chance to chance pop for
Tuesday and the first half of Wednesday. Temperatures will remain
warmer than average for Tuesday, but the cold front will have passed
for Wednesday, allowing for temperatures closer to average.
&&
.AVIATION /06Z Wednesday THROUGH Sunday/...
Cirrus coverage has generally diminished early this morning with
most spots reporting scattered or less. However, any cirrus
remaining will still linger ahead of a cold front that is expected
to pass through the area early Thursday morning. The big story is
throughout the day, winds are expected to be on the increase from
the south/southwest ahead of the front and a couple spots may see
gusts at or above 20 kts. KERI may even see the wind gusts to 25
kts with enhanced downslope flow as the cold front moves in
closer. Not expecting any ceiling or any visibility/weather issue
through the day on Wednesday, but some mid to high level clouds
will be about and perhaps some diurnal cumulus may form if the
temperatures really do soar well into the 70s Wednesday afternoon.
Late in the TAF period, the cold front will be just off to the
west of KTOL and KFDY and any precipitation associated with the
front will begin to impact the western TAF sites late Wednesday
night into early Thursday morning. The best timing for rain looks
to be in the overnight hours and with any rainfall brings the
chance for non-VFR conditions...although the rain won`t be all
that heavy so any cig/vsby change would be gradual.
OUTLOOK...A period of non-VFR possible Thursday Morning in
showers.
&&
.MARINE...
A cold front approaching from the west will allow for increasing
southerly to southwesterly winds through the day today. Winds should
start around 10 knots and will likely increase into the 15 to 20 knot
range as the front gets closer to Lake Erie. The front itself looks
to pass through Lake Erie Thursday morning and winds will
quickly shift from the southwest to the northwest and will stay at
about the 20 knot mark. With the wind shift, winds and waves will be
close to small craft advisory conditions, but it still looks
somewhat marginal at the moment and perhaps for only a couple hours
at that, so have not issued a SCA, and will let future shifts
evaluate.
Behind the front, high pressure will build in from the west and
become centered over the eastern Great Lakes on Friday morning.
Winds will decrease over time on Thursday and become 10 knots or
less and from the north by Friday, before shifting to the east by
Friday afternoon. From there, lake conditions look to be relatively
benign through much of the weekend, until the next cold front
approaches late Sunday.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...None.
PA...None.
MARINE...None.
&&
$$
SYNOPSIS...TK
NEAR TERM...TK
SHORT TERM...TK
LONG TERM...Sefcovic
AVIATION...Sefcovic
MARINE...Sefcovic
Area Forecast Discussion
National Weather Service Cheyenne WY
223 AM MDT Wed Oct 12 2016
.SHORT TERM...(Today through Friday)
Issued at 223 AM MDT Wed Oct 12 2016
Some lingering very light pcpn will end across the CWA early this
morning as any weak lift is ended behind a departing shortwave.
fairly widespread low clouds will then break up this morning as
winds turn south to southwesterly on the back side of a surface
high sliding east over the central plains with sunny skies across
the CWA this afternoon. A cool day on tap with max temps generally
in the 50s. Cool tonight with winds turning sw to westerly
allowing for warmer air to begin its return. Much warmer
conditions for Thursday under westerly flow aloft with winds
becoming breezy over se Wy around the mtns. Similar pattern for
Friday with temps a little warmer still. May see some elevated
Fire weather concerns Thursday and Friday as humidities get rather
low in the afternoons and winds become breezy.
.LONG TERM...(Friday night through Tuesday)
Issued at 223 AM MDT Wed Oct 12 2016
Windy conditions expected in the long term. Wind headlines
certainly possible.
Upper low pressure tracking through Alberta Canada Friday night
into Saturday. GFS 700mb winds increasing to 50 knots across
Carbon and Albany Counties in response to the low and associated
cold front to the west. Craig to Casper 700mb height gradient
close to 90mtrs. Wind prone areas will probably be reaching high
wind warning criteria Friday evening.
Winds ease a little Saturday morning as gradient weakens down to
around 50mtrs and 700mb winds drop to 35 knots during the
afternoon. But they increase again Saturday night into Sunday as
the front moves into western Wyoming. This event looks to run
through Sunday afternoon before easing.
Front finally makes it into southeast Wyoming Monday with the
possibility of a winter event over the Snowy and Sierra Madre
Ranges. GFS total QPF for these mountains around .6 to .7 inches,
so we could be looking at least Advisory criteria out that way.
Secondary shortwave behind the departing low will bring
possibility of snow across Converse/Niobrara Counties and the
northern Nebraska Panhandle for Tuesday. Bora event for southeast
Wyoming as 700mb winds from the northwest at 60-65kts.
&&
.AVIATION...(For the 06Z TAFS through 06Z Wednesday night)
Issued at 1056 PM MDT Tue Oct 11 2016
Upslope flow to keep IFR/MVFR conditions going across the Nebraska
Panhandle and here at Cheyenne through the overnight hours. HRRR
guidance agrees on keeping low ceilings at KCYS and KSNY through
roughly 15-16Z.
&&
.FIRE WEATHER...
Issued at 223 AM MDT Wed Oct 12 2016
No concerns for today with cool temperatures and generally light
winds. Concern then increase Thursday and Friday as much warmer
air returns and winds increase in the afternoons. Dry for the rest
of the week.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...None.
NE...None.
&&
$$
SHORT TERM...RE
LONG TERM...GCC
AVIATION...GCC
FIRE WEATHER...RE
Area Forecast Discussion
National Weather Service Dodge City KS
408 AM CDT WED OCT 12 2016
...Updated Short Term and Long Term Sections...
.SHORT TERM...(Today and tonight)
Issued at 407 AM CDT Wed Oct 12 2016
On the whole, the inherited forecast appears to be on track. Both
the southern stream and northern stream branches of the upper
tropospheric jet were pushing east fairly quickly. Convective
activity was pushing into central and south central Kansas as of
0830z, with only very isolated, very light rain showers lingering
across west central KS. This will wane in time as subsidence enters
the picture over a large depth of the troposphere. Strongest winds
will be 20 to 25 knots sustained for about a 3 hour period or so (12-
15z roughly), tied to the passage of the isallobaric high. Winds
will drop off as the isallobaric high passes to the southeast and
the MSLP gradient relaxes as well. Diurnal temperatures were dropped
a couple degrees, in line with the WRF-ARW and the latest runs of
the HRRR and RAP models, suggesting lower to mid 50s into the
afternoon given such strong cold advection. The sun will come out by
afternoon to offset the cold advection, but it may be a case of too
little too late.
As we head into tonight, the main question will be how cold we get.
Latest indications are that a fair amount of cirrostratus will move
into western Kansas in the 03-06z time frame late this evening.
After an initial quick fall in temperatures after sunset with
mostly clear sky, temperatures will likely fall at a much slower
rate if not stabilize all together in the 06-12z time frame.
Nevertheless, temperatures should still reach 34 to 37F over a good
chunk of the southwest and west central KS region. Locations with a
forecast low of 34 (Ellis, Trego, and Rush County) will carry with
it a Frost Advisory, which was collaborated with surrounding offices
(Hastings, Wichita, Goodland).
.LONG TERM...(Thursday through Tuesday)
Issued at 407 AM CDT Wed Oct 12 2016
One major, extended polar jet will move into the West late in the
week through the weekend. The jet will be pass across the Northern
Rockies into the Northern Plains through the Upper Midwest region,
and this will keep southwest Kansas in a (very) warm sector.
Temperatures well above average will result, with one or two days
seeing highs for much of the southwest KS region into the upper 80s,
perhaps touching 90. Given the strength of extended jet, the low
level leeside trough will be pushed out a bit farther east than
usual, and this will actually act to reduce our surface winds with
the strongest MSLP gradient off to our east. It will also keep low
level moisture displaced farther east, so our precipitation chances
will be next to zero through just about the entire forecast period.
&&
.AVIATION...(For the 06Z TAFS through 06Z Wednesday night)
Issued at 1230 AM CDT Wed Oct 12 2016
A strong cold front will continue to push quickly south through
the TAF period. Strongest winds will be from 09-15z with sustained
winds in the 25 to 30 knot range at times, gusting in the 35 to 40
knots during the period of most rapid pressure rise behind the
front. A stratus ceiling will accompany the front, but ceilings
will likely remain in the MVFR range, and only for about a 3 to 5
hour period. Lighter winds and VFR will occur by late afternoon
and especially into the evening with the high pressure center
moving in.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 57 37 61 47 / 0 0 30 10
GCK 56 38 63 46 / 0 0 10 0
EHA 56 39 66 47 / 10 10 40 0
LBL 57 39 63 47 / 10 0 40 0
HYS 53 34 61 44 / 10 0 10 0
P28 58 41 60 48 / 10 0 40 30
&&
.DDC Watches/Warnings/Advisories...
Frost Advisory from 4 AM to 9 AM CDT Thursday for KSZ030-031-046.
&&
$$
SHORT TERM...Umscheid
LONG TERM...Umscheid
AVIATION...Umscheid
Area Forecast Discussion
National Weather Service La Crosse WI
556 AM CDT Wed Oct 12 2016
.SHORT TERM...(Today and tonight)
Issued at 336 AM CDT Wed Oct 12 2016
Latest water vapor satellite imagery showing upper level trough
digging over the Northern Plains. 08z surface analysis indicate cold
front extending from over Lake Superior into northern Missouri.
Scattered showers or light rain/drizzle is occurring behind the
front over southern Minnesota and northern Iowa per latest mosaic
radar. This is in response to 850-700mb QG forcing per 12.06z.
Surface cold front pushes east of the forecast area by 18z today.
The deterministic 12.00z GFS/NAM and 12.06z RAP are in decent
agreement in developing showers behind the surface front this
morning...due to 850-700mb QG forcing. With forcing/lift
diminishing/decreasing and exiting the forecast area this afternoon
...the showers will exit the eastern parts of the forecast area
around 21z today.
Colder airmass filters in behind surface front/upper level trough
this afternoon into tonight. The 12.00z GFS/NAM/ECMWF suggest 925mb
temperatures by 12z Thursday to fall to around zero degrees celsius
to plus 2 degrees celsius across the forecast area. With light
winds and clear skies tonight...temperatures will drop into the
middle 20s to around 30 across much of the forecast area and
possibly into the lower 20s in the favored cold locations. Have
issued a Freeze Warning tonight across the forecast area...except
Taylor County in north central Wisconsin.
.LONG TERM...(Thursday through Tuesday)
Issued at 336 AM CDT Wed Oct 12 2016
Upper level shortwave/surface ridge builds into the Great Lakes
Region Thursday into Friday. Subsidence underneath ridge will allow
for dry weather across the forecast area. High temperatures Thursday
will be slightly below normal with highs in the upper 40s to middle
50s. Tighter pressure gradient occurs Friday...as surface ridge
slowly pushes to the east of the forecast area. Breezy conditions
are expected...especially over higher terrain and open areas.
Main forecast concerns Friday night into Tuesday are precipitation
chances through the period. The 12.00z GFS/ECMWF/GEM are in decent
agreement in developing west to southwest flow aloft through Sunday
night...then begin to diverge significantly on strength of
deepening upper level trough over the Rocky Mountains early next
week. The 12.00z GFS deepens upper level trough and closes upper
level low over the Upper Great Lakes Region by 00z
Wednesday...while the 12.00z ECMWF remains west to east zonal flow
across the northern tier United States. The deterministic models
are in agreement moving first shortwave trough to impact the Upper
Great Lakes Region Saturday into Saturday night. This will provide
a chance for showers/thunderstorms across the forecast area...with
subtle timing differences in the shower/thunderstorm chances.
Next concern is deepening upper level trough over the Rocky
Mountains or shortwave troughs embedded in the west to east zonal
flow aloft early next week. With the 12.00z GFS/ECMWF showing
significant differences in the overall flow pattern...confidence in
timing of precipitation chances into the forecast area remains low.
However...the deterministic models indicate an active weather
pattern developing for early next week...with periodic precipitation
chances Monday into Tuesday.
&&
.AVIATION...(For the 12Z TAFS through 12Z Thursday morning)
Issued at 556 AM CDT Wed Oct 12 2016
The post frontal showers have not expanded much in coverage
overnight as the forcing from the short wave trough still has
caught up with them. The 12.09Z RAP suggests the pv advection in
the 500-300 mb layer should increase the forcing this morning and
the hi-res meso scale models are still showing a general increase
in the showers this morning. Plan to show a period of light rain
for both airports with no visibility restriction for the mid to
late morning hours. Observations indicate MVFR ceilings are not
very far to the west of KRST and expect that these will work in as
the showers are ending with KLSE staying MVFR into the afternoon.
As high pressure builds in from the west, the clouds should
scatter out late this afternoon and then become clear for the
overnight hours. The northwest winds will have gusts of 20 to 25
knots for most of the afternoon before diminishing around sunset.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...Freeze Warning from 2 AM to 9 AM CDT Thursday for WIZ029-032>034-
041>044-053>055-061.
MN...Freeze Warning from 2 AM to 9 AM CDT Thursday for MNZ079-086>088-
094>096.
IA...Freeze Warning from 2 AM to 9 AM CDT Thursday for IAZ008>011-018-
019-029-030.
&&
$$
SHORT TERM...DTJ
LONG TERM...DTJ
AVIATION...04
Area Forecast Discussion
National Weather Service Cheyenne WY
456 AM MDT Wed Oct 12 2016
.SHORT TERM...(Today through Friday)
Issued at 223 AM MDT Wed Oct 12 2016
Some lingering very light pcpn will end across the CWA early this
morning as any weak lift is ended behind a departing shortwave.
fairly widespread low clouds will then break up this morning as
winds turn south to southwesterly on the back side of a surface
high sliding east over the central plains with sunny skies across
the CWA this afternoon. A cool day on tap with max temps generally
in the 50s. Cool tonight with winds turning sw to westerly
allowing for warmer air to begin its return. Much warmer
conditions for Thursday under westerly flow aloft with winds
becoming breezy over se Wy around the mtns. Similar pattern for
Friday with temps a little warmer still. May see some elevated
Fire weather concerns Thursday and Friday as humidities get rather
low in the afternoons and winds become breezy.
.LONG TERM...(Friday night through Tuesday)
Issued at 223 AM MDT Wed Oct 12 2016
Windy conditions expected in the long term. Wind headlines
certainly possible.
Upper low pressure tracking through Alberta Canada Friday night
into Saturday. GFS 700mb winds increasing to 50 knots across
Carbon and Albany Counties in response to the low and associated
cold front to the west. Craig to Casper 700mb height gradient
close to 90mtrs. Wind prone areas will probably be reaching high
wind warning criteria Friday evening.
Winds ease a little Saturday morning as gradient weakens down to
around 50mtrs and 700mb winds drop to 35 knots during the
afternoon. But they increase again Saturday night into Sunday as
the front moves into western Wyoming. This event looks to run
through Sunday afternoon before easing.
Front finally makes it into southeast Wyoming Monday with the
possibility of a winter event over the Snowy and Sierra Madre
Ranges. GFS total QPF for these mountains around .6 to .7 inches,
so we could be looking at least Advisory criteria out that way.
Secondary shortwave behind the departing low will bring
possibility of snow across Converse/Niobrara Counties and the
northern Nebraska Panhandle for Tuesday. Bora event for southeast
Wyoming as 700mb winds from the northwest at 60-65kts.
&&
.AVIATION...(For the 12Z TAFS through 12Z Thursday morning)
Issued at 454 AM MDT Wed Oct 12 2016
Low ceilings across the southern Nebraska Panhandle and here at
KCYS will give way to VFR conditions towards mid morning. Used
latest HRRR guidance which shows ceilings lifting around the
15-16Z timeframe.
&&
.FIRE WEATHER...
Issued at 223 AM MDT Wed Oct 12 2016
No concerns for today with cool temperatures and generally light
winds. Concern then increase Thursday and Friday as much warmer
air returns and winds increase in the afternoons. Dry for the rest
of the week.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...None.
NE...None.
&&
$$
SHORT TERM...RE
LONG TERM...GCC
AVIATION...GCC
FIRE WEATHER...RE
Area Forecast Discussion
National Weather Service Dodge City KS
541 AM CDT WED OCT 12 2016
...Updated aviation section...
.SHORT TERM...(Today and tonight)
Issued at 407 AM CDT Wed Oct 12 2016
On the whole, the inherited forecast appears to be on track. Both
the southern stream and northern stream branches of the upper
tropospheric jet were pushing east fairly quickly. Convective
activity was pushing into central and south central Kansas as of
0830z, with only very isolated, very light rain showers lingering
across west central KS. This will wane in time as subsidence enters
the picture over a large depth of the troposphere. Strongest winds
will be 20 to 25 knots sustained for about a 3 hour period or so (12-
15z roughly), tied to the passage of the isallobaric high. Winds
will drop off as the isallobaric high passes to the southeast and
the MSLP gradient relaxes as well. Diurnal temperatures were dropped
a couple degrees, in line with the WRF-ARW and the latest runs of
the HRRR and RAP models, suggesting lower to mid 50s into the
afternoon given such strong cold advection. The sun will come out by
afternoon to offset the cold advection, but it may be a case of too
little too late.
As we head into tonight, the main question will be how cold we get.
Latest indications are that a fair amount of cirrostratus will move
into western Kansas in the 03-06z time frame late this evening.
After an initial quick fall in temperatures after sunset with
mostly clear sky, temperatures will likely fall at a much slower
rate if not stabilize all together in the 06-12z time frame.
Nevertheless, temperatures should still reach 34 to 37F over a good
chunk of the southwest and west central KS region. Locations with a
forecast low of 34 (Ellis, Trego, and Rush County) will carry with
it a Frost Advisory, which was collaborated with surrounding offices
(Hastings, Wichita, Goodland).
.LONG TERM...(Thursday through Tuesday)
Issued at 407 AM CDT Wed Oct 12 2016
One major, extended polar jet will move into the West late in the
week through the weekend. The jet will be pass across the Northern
Rockies into the Northern Plains through the Upper Midwest region,
and this will keep southwest Kansas in a (very) warm sector.
Temperatures well above average will result, with one or two days
seeing highs for much of the southwest KS region into the upper 80s,
perhaps touching 90. Given the strength of extended jet, the low
level leeside trough will be pushed out a bit farther east than
usual, and this will actually act to reduce our surface winds with
the strongest MSLP gradient off to our east. It will also keep low
level moisture displaced farther east, so our precipitation chances
will be next to zero through just about the entire forecast period.
&&
.AVIATION...(For the 12Z TAFS through 12Z Thursday morning)
Issued at 536 AM CDT Wed Oct 12 2016
Windy conditions are anticipated this morning as strong northerly
winds blow at around 25 knots with gusts over 30 knots. These
winds then decrease to around 20 knots by this afternoon then
below 12 knots by this evening. IFR conditions are expected this
morning due to ample low level clouds AOA015. VFR conditions
return by this afternoon as cloudiness decreases and ceilings
rise.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 57 37 61 47 / 10 0 30 10
GCK 57 38 63 46 / 0 0 10 0
EHA 56 39 66 47 / 10 10 40 0
LBL 57 39 63 47 / 10 0 40 0
HYS 53 34 61 44 / 10 0 10 0
P28 59 41 60 48 / 10 0 40 30
&&
.DDC Watches/Warnings/Advisories...
Frost Advisory from 4 AM to 9 AM CDT Thursday for KSZ030-031-046.
&&
$$
SHORT TERM...Umscheid
LONG TERM...Umscheid
AVIATION...Hovorka_42
Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
409 PM EDT WED OCT 12 2016
.DISCUSSION...
As of 19Z, the primary synoptic scale cold front is in place over
sections of far southeastern Wisconsin and northern Illinois. The
main theta e corridor is east of the cold front with the low level
moisture max over western lower michigan. The lead edge of the theta
e corridor just now pushing into southeastern Michigan, with a low
to midlevel cyclonic circulation attached to this boundary over far
northern Illinois. Model data ejects the cyclonic circulation
northeastward while shearing out, pushing near the Saginaw Valley
and Saginaw Bay around 00Z this evening. The added warm advection
provided by this cyclonic circulation will provide the push to begin
precipitation for this event. Model data has been a little noisy the
past 24 hours both with regards to both the start times for
categorical rain chances and the end time of the event.
Latest hi res explicit convection allowing solutions have slowed the
onset, to as late as 23-00Z. Current trends of convection
initiating over western Lower Michigan casts doubt on that slow of
timing, but the categorical rains should fall between 23-05Z. Main
item to monitor is the potential for thunderstorm activity during
the next 3 to 6 hours. Latest observational analysis including the
RAP based mesoanalysis supports SBCAPE of between 500-1000 J/KG with
ML CAPE of around 500 J/KG. Evolution of forecast CAPE is bearish
with the integrity of the surface based instability ribbon as it
arrives locally. As a result, not overly excited about strong wind
potential with the convection but there has been enough surface
observational evidence to support that gusty winds will be possible
with this convection. An isolated wind gust to 40 mph will be
possible this evening.
Data has really abandoned the solution that supported a secondary,
separate fgen response later tonight. The overwhelming trend has
been to consolidate both the fgen response with the main warm air
advection support and right entrance region dynamics. Thus, expect
the bulk of the rain to push out of the area already by 06z. There
may be some lingering drizzle for a time as low level cold air
advection ramps up, but the model signal is not overly strong there.
A big change to the forecast was to increase clouds substantially
for Thursday in the wake of the cold front. Satellite and surface
observations have shown stout stratus in place over the Eastern
Dakotas today directly within the eastern hemisphere of the surface
high pressure. A very good structure to the low or midlevel
subsidence inversion supports keeping cloud, moisture, saturation
locked in. Did go aggressive with clearing trend in the late
afternoon. Did lower the offered guidance by a degree or two, but
still could be too warm. Current surface temperatures this
afternoon over portions of Wisconsin remain in the middle 40s.
Sprawling surface high pressure will be in place for Thursday night.
Numbers come in a little cooler with these successive runs. At this
time, looks like a good bet on frost advisories for just about
everyone, and may need to even look at possible Freeze Warnings
especially across the northern CWA.
High pressure centered over the Northeastern US and low pressure
centered over Manitoba/Ontario allow southerly winds to bring in
warm air, pushing temperatures into the the mid to upper 60s for a
daytime high, with a shot at 70 closer to the MI/OH border on
Saturday. As low pressure moves further east into Ontario, it will
drag along with it a cold front through Michigan, which is expected
to bring scattered showers with a rumble of thunder possible into
the region. Next week looks to be a fairly active one as a series of
low pressure systems from the Central Plains pushes northeast into
Michigan. As the lows move over us, the chance for additional rain
showers will exist. Otherwise, the early part of next week looks to
remain mild as 12-15C 850 mb temps sits over the region.
&&
.MARINE...
The strongest wind event of the young autumn season is getting
underway as gusty fresh southerly flow continues to develop in
advance of an approaching cold front. Passage of the front will
bring a sharp shift in winds to northwesterly with near-gales likely
across the open waters of Lake Huron and possibly the exposed
nearshore waters of the Thumb. Brief or isolated gale-force wind
gusts will be possible but are forecast to be short-lived. The
highest liklihood of gale-force wind gusts will be along the front
itself. Significant wave heights will approach 10 feet over the open
waters of central Lake Huron. Small craft advisories remain in
effect for nearshore zones.
&&
.HYDROLOGY...
Abundant moisture streaming north in advance of a strong cold front
will bring widespread showers tonight. Showers are forecast to reach
the Saginaw Valley area around 6 PM local time eventually reaching
the Detroit Metro area between 8 PM and 9 PM. Widespread rainfall
amounts approaching one half inch are expected with the heaviest
rain falling prior to 11 PM at all locations.
&&
.PREV DISCUSSION...
Issued at 111 PM EDT Wed OCT 12 2016
AVIATION...
Southwest wind expected to become gusty to 20-25kt as mixing
increases this afternoon. Modest VFR CU up this afternoon before
cigs fall to MVFR stratus with the approach of the upstream moisture
plume over the MS Valley and Western Great Lakes this evening. Gusts
will fall off after loss of diurnal heating, but gradient will
remain elevated through the night. Showers begin from west to east
roughly 23z to 02z save for some isolated warm advection showers
lifting through MBS this aftn. Chance of thunder expected to be
minimal...best chance north of KPTK 20-23z. Wind shift to NW will
occur with passage of the cold front. Cold advection and lake
enhancement will support MVFR stratus into Thursday morning.
//DTW Threshold Probabilities...
* Medium for cig aob 5kft after 22z. High after 02z.
* Low for thunderstorms with the cold front 01-03z.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
Lake Huron...Small Craft Advisory until 5 AM EDT Thursday FOR LHZ422.
Small Craft Advisory from 10 PM this evening to 10 AM EDT Thursday
FOR LHZ441-442.
Small Craft Advisory until 10 AM EDT Thursday FOR LHZ421.
Lake St Clair...NONE.
Michigan waters of Lake Erie...NONE.
&&
$$
DISCUSSION...CB/AM
MARINE.......JVC
HYDROLOGY....JVC
AVIATION.....JVC
You can obtain your latest National Weather Service forecasts online
at www.weather.gov/detroit.
Area Forecast Discussion
National Weather Service Grand Forks ND
250 PM CDT Wed Oct 12 2016
.SHORT TERM...(This evening through Thursday)
Issued at 212 PM CDT Wed Oct 12 2016
The forecast challenge for tonight will be sky trends and impacts
on overnight lows. Current vis imagery showing stratocu across
majority of area with a hole over the Grafton area. Back edge of
cloud cover vcnty of Missouri river basin should arrive in
western zones around 23Z to 00Z per HRRR low layer RH field.
CONSSHORT is slightly slower clearing out southeast ND and do
prefer the slower solution, however with cellular nature of clouds
do expect some gradual dissipation along with clearing line
advecting east. Less confidence across the north where HRRR keeps
mostly cloudy skies across portions of northwest MN through the
overnight period. However, given trends to the west along intl
border, does appear modeled low level RH and sky cover may be
overdone. Winds will become lightest in the mid evening hours as
sfc ridge shifts east of the CWA and westerly winds subside before
turning southwesterly for remainder of night.
Overnight lows will fall into the mid-20s by morning if
widespread clearing does occur...bringing the coldest night and
hardest freeze...of this fall. Issued a special weather statement
declaring an end of the growing season with no further frost or
freeze products planned for 2016.
Full solar but weak flow will allow daytime highs to rebound into
the mid 40s to upper 50s, from north to south, across the region
on Thursday. Any stronger than expected mixing across the south
could bump temperatures above the 60 mark, but the warmest
temperatures will arrive in the early part of the long term
period.
.LONG TERM...(Thursday night through Wednesday)
Issued at 212 PM CDT Wed Oct 12 2016
Models begin the long term period Thursday night in good agreement
with 500mb zonal flow aloft. 850mb WAA and strong LLJ, increasing to
30 to 40kts, persisting through the day Friday into Friday night
will allow max temps to rise into the 60s to end the week with
strong south winds turning to the west for Saturday. SFC trough will
push through on Friday night or early Saturday morning with limited
moisture. Will keep a slight rain mention confined to the northern
areas late Friday into Saturday.
By Sunday afternoon the next shortwave in the SW flow aloft begins
to influence the region. Increasing chances for showers and possibly
an isolated thunderstorm into the evening hours with showalters
around zero and a strong LLJ nosing into the southern valley. Models
begin to diverge with their solns by Monday with the energetic 500mb
flow. The GFS continues to wind up a storm system in the central
plains whereas the ECMWF maintains a more progressive soln.
&&
.AVIATION...(For the 18Z TAFS through 18Z Thursday afternoon)
Issued at 1256 PM CDT Wed Oct 12 2016
Sites in and west of the Red River Valley will see VFR cigs
gradually dissipate by mid-evening. MVFR cigs at TVF and BJI will
continue to rise to VFR by early evening, with expectation they
will scatter out of BJI area by midnight tonight. High pressure to
the south should provide enough westerly-to-southerly winds to
keep fog from generating tomorrow morning.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...None.
MN...None.
&&
$$
SHORT TERM...Speicher
LONG TERM...JK
AVIATION...Speicher
Area Forecast Discussion
National Weather Service Goodland KS
410 PM MDT Wed Oct 12 2016
.SHORT TERM...(This evening through Thursday)
Issued at 120 PM MDT Wed Oct 12 2016
19Z Water vapor imagery RAP analysis indicated strong short wave
trough moving across MN and IA forcing strong cold front into
central TX and eastern OK. 1028 MB Sfc high was settling over the
GLD area begins front with persistent area of low clouds on
western periphery of high. Main concern tonight will be possible
frost...followed by increasing winds tomorrow morning and
afternoon.
Most prevailing concern is area of stratus that continues across
eastern Colorado and adjacent areas. While it is breaking up
currently...doubtful that it will totally dissipate and may
advect back into the area tonight. Further complicating
things...clouds will precondition environment for potential fog
development just ahead of developing return flow. Despite small
T-Td spreads and favorable hydrolapse rates...increasing southerly
winds should create enough mixing to offset radiational fog
development so am not anticipating a widespread fog event. The
combination of increased clouds and increasing southerly flow will
limit freeze/frost potential in the west. However for eastern
areas...skies will clear and winds will decouple quickly
tonight...well before mid level clouds begin to increase ahead of
next system. Think widespread 30-33 lows likely and would not be
shocked to see an isolated hard freeze in a few areas and river
valleys. Would consider a greater threat for hard freeze...but
soundings indicate moisture increasing with height near boundary
layer and does not look like a pattern where tds will crash with
the sfc temp and may actually promote a bit of fog instead.
On Thursday gusty southerly winds will increase across the area as
sfc high departs. Expect to see a few 30 mph gusts...but do not
anticipate a significant wind event. Temps will remain somewhat
cool near departing sfc high and expect a sharp gradient in
temperatures from west to east. The cooler temps will minimize the
fire wx threat even with the stronger winds.
.LONG TERM...(Thursday night through Wednesday)
Issued at 209 PM MDT Wed Oct 12 2016
With a dry forecast expected through the middle of next week across
the Central High Plains region, the forecast focus is on
temperatures, wind, and the possibility of elevated fire weather
conditions on Friday.
A short wave trough aloft is transported east of the Rockies and
across the southern and central high plains region on Thursday
afternoon in the westerly flow aloft. The surface trough deepens
over eastern Colorado Thursday night into Friday. Gusty south winds
and high temperatures in the lower to mid 80s are expected ahead of
the surface trough on Friday afternoon. Dry downslope winds along
the Front Range will extend onto the plains with dewpoints in the
20s producing RH values in the 10-15% range over the far western
sections of the forecast area.
The westerly to south southwesterly flow aloft strengthens as a
series of short wave troughs travel through the northern branch of
the upper flow across the U.S./Canada border region. Models are in
reasonable agreement through the weekend and into Monday of next
week, but begin to differ to a greater degree into the middle of
next week. The GFS amplifies the initial through tracking east of
the Rockies Monday into Tuesday while the ECMWF amplifies the second
trough that moves through late Wednesday, while both amplify a ridge
over the western U.S. late next week in the wake of the upper
troughs. The CONSALL seems to be favoring the stronger initial wave
depicted on the GFS as the upper pattern sagging further southward
with the incoming westerly troughs, areas east of the Rockies are
opened up to colder airmasses spreading southward from the northern
high plains through the plains states. This is reflected in the
cooler temperatures expected on Tuesday and Wednesday as gusty north
to northwest winds move in behind a cold front that sweeps across
the region Monday evening.
Have not identified any strong targets of opportunity to improve the
forecast over the Superblend primary grid initialization between the
Period 2 and Day 7, so have left things pretty much as they are.
With precipitation hinted at late Wednesday as the second upper
trough moves east of the Rockies, can see the need to monitor the
middle to latter part of next week a little more closely as that
time period moves closer and the models begin to converge towards a
single solutions.
&&
.AVIATION...(For the 00Z TAFS through 00Z Thursday evening)
Issued at 410 PM MDT Wed Oct 12 2016
For KGLD and KMCK, vfr conditions expected through the period. A
weather disturbance is forecast to move across the tri-state area
from early this evening through mid morning Thursday. Moisture is
confined to the mid and upper levels of the atmosphere...generally
above 10K ft. A few showers are possible as it moves through but
at this time too low to include in the forecast. Clearing is
expected late in the day as it continues moving away from the
area. Winds generally light at taf issuance with an expected veer
to the south 10kts or less by 07z continuing through sunrise.
During the mid to late afternoon hours winds increase from the
south with gusts around 25kts expected.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...Frost Advisory from 1 AM to 10 AM CDT Thursday for KSZ001>004-
014>016-029.
CO...NONE.
NE...Frost Advisory from midnight MDT /1 AM CDT/ tonight to 9 AM MDT
/10 AM CDT/ Thursday for NEZ079>081.
&&
$$
SHORT TERM...JRM
LONG TERM...LOCKHART
AVIATION...99