Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 10/10/16
Area Forecast Discussion
National Weather Service Green Bay WI
611 PM CDT SUN OCT 9 2016
Updated aviation portion for 00Z TAF issuance
.SYNOPSIS...
Issued at 209 PM CDT Sun Oct 9 2016
Warmer the next couple days, then some rain and turning cooler mid-
week.
Highly amplified flow over the eastern Pacific will result in
strong downstream amplfication over North America the next several
days. Then during the latter half of the forecast period, a strong
Pacific jet will undercut the sharp ridge along the West Coast,
and spread eastward across the CONUS.
Temperatures will return to above normal tomorrow, briefly drop
back close to seasonal normals mid-week, then warm again for the
latter part of the period. The main opportunity for precipitation
will be with a frontal system crossing the area mid-week. Somewhat
lower chances exist with a weaker shortwave arriving prior to the
main system, and possibly with a second frontal system late in
the period. Normal precipitation for a week at this time of year
is a little over 1/2 inch, and the pattern seems as though it will
support near-normal amounts.
&&
.SHORT TERM...Tonight and Monday
Issued at 209 PM CDT Sun Oct 9 2016
The latest RAP analysis and satellite/radar imagery show a large
high pressure system centered across the area early this afternoon.
Light onshore flow off of Green Bay and Lake Superior/Michigan have
contributed to cu popping with daytime heating earlier this morning.
Otherwise, conditions are relatively quiet. Looking upstream,
widespread mid and high clouds are pushing east over the far
northern Plains and southern Canada, but the northern Mississippi
Valley remains mostly clear. As high pressure slides east tonight,
cloud trends and temps remain the primary forecast concerns.
Tonight...High pressure will be sliding east of the area, causing
winds to shift to the southeast and then south in response. Ample
dry air will keep most of the region clear, except for possibly the
lakeshore, where lake clouds could shift onshore as winds shift.
Still some possibility for winds to decouple over sandy soil areas
in the route 141 corridor and have lowered temps here into the upper
30s. Though think temps will be too warm for widespread frost, did
add patchy frost to this area. Otherwise, low temps should range
from the upper 30s to middle 40s.
Monday...The region will be located between high pressure centered
over the eastern Great Lakes and a cold front positioned over the
northern Plains. While a southern stream shortwave will be moving
across the central Plains, very dry air will reside over the western
Great Lakes region, providing ample sunshine. Southerly flow will
bring in warmer air, with max temps rising into the mid and upper
60s.
.LONG TERM...Monday Night Through Sunday
Issued at 209 PM CDT Sun Oct 9 2016
Lead shortwave crossing the area late Monday night and Tuesday may
generate some light precipitation. Then there will be a lull in
the rain chances before the main shortwave and a strong frontal
system arrive in the area Tuesday night and Wednesday. Models
really don`t show it yet, but it appears the upper shortwave may
eventually result in some slowing of the main frontal system with
a secondary wave riding up the front. If that occurs, it could
result in rain chances lingering a little longer than what we
currently have in the 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 flattening of the upper flow will cause the
cool air to quickly shift off to the east, with milder
temperatures returning by next weekend.
&&
.AVIATION...for 00Z TAF Issuance
Issued at 611 PM CDT Sun Oct 9 2016
High pressure will be moving across the region through the end of
the taf period, resulting in good flying weather for most
locations. Patchy ground fog will again be possible late tonight
into Monday morning over northern WI. Conditions could drop to
LIFR at RHI with the patchy dense fog.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS.......Skowronski
SHORT TERM.....MPC
LONG TERM......Skowronski
AVIATION.......Kurimski
Area Forecast Discussion
National Weather Service North Platte NE
631 PM CDT Sun Oct 9 2016
.SYNOPSIS...
Issued at 239 PM CDT Sun Oct 9 2016
Long wave trough within the northern stream located across western
Canada early this afternoon with downstream ridging occurring across
the upper midwest and southern Canada as seen in water vapor
imagery. Height rises associated with the building downstream ridge
fairly significant, in the 50-100m range at H5. Some cooling of
cloud tops across the northern Rockies in somewhat disorganized warm
advection zone. Further south, weak upper low within broad southwest
flow now moving into southern CO with scattered showers in warm
advection across KS and wrn TX, and over the southern Rockies.
Coverage of precip with this feature is not great despite PW values
in excess of 150 percent. Otherwise full sunshine across NE this
afternoon and temps 5-10 degrees above ave for this time of year.
&&
.SHORT TERM...(through Tonight)
Issued at 239 PM CDT Sun Oct 9 2016
Main forecast challenge through tonight will be potential for fog
after about 3 AM or so. With low level moisture increasing through
this afternoon, a crossover temp would be in the 50-52 range for
much of southwest NE. Since low temps are forecast in the upper 40s
in the southwestern portion of the state, this would approximate a
favorable hydrolapse to support fog formation given primarily clear
skies overnight. This is further supported by vertical specific
humidity profiles in BUFR soundings from NAM and to some extent RAP
in the southwest. In addition, MOS guidance from NAM also in favor
of a fog situation. The only detraction to this setup would be
development of mid level clouds which would inhibit potential for
radiative cooling. For now thinking is the development of mid clouds
would favor areas east of the previously mentioned areas.
So have added patchy and areas of fog in portions of southwest NE
overnight. This would generally be east of the lee trough axis and
mainly west of Highway 83. This would also likely include the I80
corridor so impacts and extent of visiblity will be monitored
carefully through the night.
Going back to the development of mid level cloudiness...the
development of a low level jet tonight, associated with the
aforementioned weak low to the south, paired with isentropic
downglide associated with northern stream will lead to mid level
frontogenesis in a region of elevated instability. This will occur
primarily east of the area but may affect the resulting cloud
cover across the southern portion of the forecast area. Should
development occur earlier, this would limit radiational cooling
affecting low temps and also fog potential. Again this will be
monitored for updates.
.LONG TERM...(Monday through Sunday)
Issued at 239 PM CDT Sun Oct 9 2016
A well-defined dry line punching in from the west will determine how
low temperatures start in the morning. The GFS at 12z Mon for
example has a dewpoint of 52 degrees F in eastern Cherry county
while western Cherry county will be around 26 degrees F. Luckily
this dry air is not supposed to move in until we get closer to
sunrise so temperatures will not have much time to react. In
addition, there will be some fog forming along the dry line as
well that will help insulate but could create low visibilities for
the morning drive between Highways 61 and 83.
Southwest winds in advance of a cold front will help warm and dry
the boundary layer on Monday afternoon. High temperatures are still
expected to be 10-15 degrees above normal as high temperatures are
forecast to be around 80 degrees.
Given the aforementioned dry line and the above average high
temperatures, relative humidities will naturally be on the low side,
especially across the northwest. Model guidance continues to hold
wind speeds below Red Flag Warning criteria, at around 15 to 20kts,
with some gusts briefly exceeding criteria but again, this is
expected to be too brief to warrant a warning but at the same
time, it will definitely not be a great day to do any outdoor
burning.
The ridge continues to break down on Tuesday as a trough continues
to march southeast out of Canada. Winds will shift to be out of the
North on Tuesday with much cooler temperatures expected behind a
front, especially across the Sandhills where highs will struggle to
meet 50 degrees. The front itself is pretty dry but there will be a
chance for some precipitation later in the night as some stronger QG
forcing arrives along with the trough. It is certainly cold enough
aloft for some snowfall but given the mild surface temperatures, it
will have a tough time sticking but it can stick to elevated
surfaces and grasses, like we saw with the last system. However, we
don`t have the nearly stationary frontogenesis band that we had with
the last system, most of the precipitation will move in and out
fairly fast...that will also limit any snow that does have the
chance to accumulate. There will be rapid clearing behind the mid
level front as downward forcing behind the trough takes over. Frost
will be a concern Wednesday morning with highs only rebounding into
the upper 40s to lower 50s by afternoon.
After Wednesday, heights again rise into the weekend with a return
to 70 and even 80 degree temperatures by Friday and Saturday. The
forecast also remains dry after Tuesday Night.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 631 PM CDT Sun Oct 9 2016
Over the next 24 hours, skies will be mostly clear across western
and north central Nebraska. There is a small threat for fog
development at the KLBF terminal toward day break Monday morning.
Inherited forecast had a tempo group for 3 SM from 10z to 14z
Monday morning. Will eval this further with this evenings forecast
runs. Winds will be southerly or southwesterly at under 10 KTS
tonight, increasing to 10 to 20 KTS Monday.
&&
.FIRE WEATHER...
Issued at 239 PM CDT Sun Oct 9 2016
...Outdoor burning not recommended on Monday in Sheridan...
Cherry...Garden...Grant...Arthur...Keith...and Deuel Counties...
Unseasonably warm temperatures and the advancement of a dry line
early on Monday will drop Relative Humidity values into the upper
teens on Monday afternoon. In addition, winds will pick up in the
afternoon to around 20 mph with occasional higher gusts possible
across northwestern Nebraska. Areas east of a line from about
Valentine to Imperial will have significantly higher RH. A dry
cold front is forecast to drop into the area from the north after
midnight, shifting wind directions to the north with a period of
gusty wind but ushering in cooler temperatures and higher
relative humidities for Tuesday at the same time. There will be a
chance of wetting rain and/or snow on late Tuesday night and
Wednesday followed by high temperatures about 15 degrees below
normal.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SYNOPSIS...Stoppkotte
SHORT TERM...Stoppkotte
LONG TERM...Allen
AVIATION...Buttler
FIRE WEATHER...Allen
Area Forecast Discussion
National Weather Service Omaha/Valley NE
631 PM CDT SUN OCT 9 2016
.SHORT TERM...(tonight through Wednesday)
Issued at 315 PM CDT Sun Oct 9 2016
Forecast concerns in the short term will be shower and
thunderstorm chances late tonight through Monday evening and how
much the clouds will hold back temperatures...then precipitation
chances Tuesday night and Wednesday and if it be cold enough for
a mix of precipitation for parts of northeast Nebraska by
Wednesday morning.
Latest water vapor satellite imagery/h5 heights show a shortwave
trough over Colorado with a more expansive area of low
pressure/h5 trough from the Northwest Territories toward Vancouver
Island and the Pacific Ocean.
The visible satellite shows a disturbed area of clouds with the
shortwave over Colorado and Kansas. With the warmer air returning
and gusty south winds with the warmer air lifting
north...temperatures returned to the 70s today.
The short term forecast progs are in good agreement that the
shortwave trough over Colorado will move into the Plains. A
strengthening low level jet of 35 to 40kts and increasing h85
dewpoints to 10 to 12 deg C with theta-e advection will result in
the chance for showers and a few thunderstorms. A few echoes were
noted across Kansas. The SPC HRRR and the RAP/ESRL HRRR have the
echoes near the Kansas/Nebraska border mainly aloft...with
coverage increasing from isolated then scattered showers between
06-12z spreading into southeast Nebraska Monday morning then
shifting into Iowa. Precipitation should be generally along and
south of I80 in Nebraska then into western Iowa. CAPE appears
limited...however there is some elevated instability. pwat values
increase to around 1 to 1.25 inches. A few showers are expected to
linger in far southeast Nebraska and our southern Iowa counties
during the evening. Temperatures will be held down in southeast
Nebraska and western Iowa (upper 60s to lower 70s), however
farther north in northeast Nebraska highs should top out in the
mid and upper 70s.
The longwave trough from the Pacific Northwest and Canada
approaches from the north and by Tuesday...A cold front is moving
across the forecast area. There is instability ahead of the front,
however the precipitation appears limited. Isolated precipitation
appears post- frontal in northeast Nebraska Tuesday near the South
Dakota border. Tuesday night rain chances increase as the upper
level support strengthens. By Wednesday morning...h85 temperatures
drop to zero or cooler, however the bulk of the precipitation appears
to end before it can turn to a mix.
Tuesday should be in the 60s and 70s, however much cooler highs in
the upper 40s and 50s are forecast for Wednesday.
Brisk southwest winds are expected Monday and brisk northwest
winds are forecast behind the front Wednesday.
.LONG TERM...(Wednesday night through Sunday)
Issued at 315 PM CDT Sun Oct 9 2016
...After a cold start, the rest of the extended shows a
warming trend...
Surface high pressure is over the area at the start of the extended
with h85 temperatures around +4 deg C. Current forecasts have lows
30 to 35 across the forecast area and these will be highly dependent
on where the surface ridge is along with cloudcover and winds.
A weak shortwave moves across the southern Plains, clipping
southeast Nebraska and southwest Iowa...thus the shower chances
there Thursday afternoon and Thursday night. The models differ on
the timing and strength of the next front. The GFS tends to be a
little stronger with is and has the front through Saturday night,
while the EC is weaker and stalls the front Sunday. For now there
is a rain mention Saturday night and Sunday night, however northeast
Nebraska remains dry through the period.
Highs start out in the 50s Thursday...rise to the 60s Friday with
70s forecast for Saturday and Sunday.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 627 PM CDT Sun Oct 9 2016
Mainly VFR conditions are forecast through Monday afternoon. A low
pressure system will eject into eastern Nebraska late tonight, and
will bring lowering cigs and a chance for showers and isolated
thunderstorms. However cigs should remain VFR near FL050,
affecting KLNK and KOMA. Also, coverage of showers is expected to
be spotty, and any thunderstorms even more isolated. Thus have
omitted mention in TAF for now. South winds will kick up into the
15 to 25kt range after 12Z Monday. And there will likely be some
low level wind shear near KOFK and KLNK between 06Z and 15Z when
south to southwest winds at FL020 will average 40kt.
&&
.OAX Watches/Warnings/Advisories...
NE...None.
IA...None.
&&
$$
SHORT TERM...Zapotocny
LONG TERM...Zapotocny
AVIATION...Dergan
Area Forecast Discussion
National Weather Service Spokane WA
715 PM PDT Sun Oct 9 2016
.SYNOPSIS...
A moist frontal band will persist over southern Washington and
the southern ID panhandle tonight before exiting Monday with
moderate to heavy rainfall possible. Scattered rain and high
mountain snow showers will linger over north Idaho Monday and
Tuesday as dry and chilly Canadian air pushes in from the north.
Widespread freezing temperatures will be likely Wednesday morning.
Another wet and active weather period is expected Thursday through
next weekend.
&&
.DISCUSSION...
Main change to the forecast was to bump up rainfall amounts a bit
more across the Palouse and into the Central Panhandle Mtns for
overnight. Satellite is showing a dynamic shortwave trough of
lower pressure digging into western WA this evening. There has
been a noticeable enhancement of the rainfall on radar over
southwest WA and northeast OR as this wave approaches. The added
dynamics aloft combined with some stronger frontal dynamics is
expected to result in heavier rainfall once this wave pushes
across the Cascades after 10:00 PM this evening. Heaviest rainfall
will be across southeast WA and into the Central Panhandle Mtns
where orographics will also aid in additional lift.
The HRRR model suggest rain rates of up to 0.35 inches per hour
over a one to two hour period. Overall, we can expect an
additional 1-2 inches of rainfall for the wettest areas from the
Palouse to the Central Panhandle Mtns. We will continue to monitor
small streams and creeks for potential flooding issues. Paradise
Creek flowing through Moscow will be especially susceptible to
sharp rises overnight. I also expect puddling of water on roadways
that will increase the risk for hydroplaning. Heavy rain will also
result in rapid drops in visibility down to 1 mile at times. /SVH
&&
.AVIATION...
00Z TAFS: A frontal boundary remains stalled across southern WA
from the coast at the WA/OR border to western MT. Moderate to
locally heavy rain will occur along the leading edge of the front.
The band of rain will pivot slightly northward early this evening
with the northern edge of the rain reaching KGEG, KSFF and KCOE
around 02Z. Then the rain will shift southeast as a dynamic upper
level shortwave trough transverses across the area. This will
enhance the rainfall with a better chance for heavy rain across
the Palouse into the Central Panhandle Mtns and points
southeastward. IFR conditions are expected along and southeast
of a line from KMWH to KCOE with LIFR conditions possible at KPUW.
A very moist boundary layer will continue to result in IFR
conditions through the morning on Monday before improving by the
afternoon. /SVH
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 42 55 33 54 32 56 / 100 10 10 0 0 0
Coeur d`Alene 44 54 32 53 30 56 / 100 20 10 10 0 0
Pullman 45 56 32 54 31 57 / 100 20 0 10 0 0
Lewiston 50 62 39 59 38 63 / 100 20 0 10 0 0
Colville 44 57 30 56 28 57 / 20 20 0 0 0 0
Sandpoint 41 52 32 51 29 52 / 90 50 10 10 10 0
Kellogg 43 49 31 49 30 53 / 100 50 20 10 10 0
Moses Lake 47 66 32 61 30 61 / 70 0 0 0 0 0
Wenatchee 45 62 38 60 37 60 / 20 0 0 0 0 0
Omak 39 61 32 60 31 61 / 10 0 0 0 0 0
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
Area Forecast Discussion
National Weather Service Pueblo CO
602 PM MDT Sun Oct 9 2016
.UPDATE...
Issued at 553 PM MDT Sun Oct 9 2016
Minor updates this evening to match the forecast to current
conditions. Isolated to scattered showers and thunderstorms will
continue south of an Eads to Trinidad line over the plains before
dissipating after sunset. The strongest storms are over eastern
Kiowa County, where half inch hail and lightning will be the main
threats. Showers and thunderstorms will continue over the mountain
areas for the next several hours, and an inch or two of snow is
possible over the peaks. Mozley
&&
.SHORT TERM...(This evening through Monday)
Issued at 325 PM MDT Sun Oct 9 2016
...An Upper Level Disturbance will Drift Slowly East Across the Area
this Evening...
An upper level disturbance near the Four Corners Region will drift
slowly eastward through the remainder of the afternoon into the
evening. The disturbance has been dropping some precipitation over
the San Juan mountains this afternoon, including 0.48 inches so far
at Durango. Webcams around Cumbres and La Manga passes also show
the rain coming down with likely some wet snow above 11 thousand
feet or so. Radar is also starting to show some showers popping
over the southern San Luis Valley and southern Sangre De Cristos
now. A few showers will likely continue to develop and spread
eastward across the plains through the evening as the upper
disturbance comes across. There is enough instability for a few
thunderstorms with primary threats of lightning, wind gusts to
around 40 mph and spotty heavy rainfall. It continues to look like
most of the action will be south of Highway 50...near the upper low
center as it moves across. The HRRR develops the most intense
activity near the low center over the far southeast plains between
about 4 and 8 PM. We will see how that goes. The Storm Prediction
Center currently has Baca County, the southeastern half of Prowers
County and a small portion of far eastern Las Animas County under a
marginal risk for severe weather this afternoon and evening. Primary
threats in those areas would be wind gusts up to 60 mph and hail up
to 1 inch in diameter. Not a big threat this evening but something
to keep an eye on.
Westerly flow aloft will bring a warmer and drier day to most of the
area Monday. However, some mid and upper level moisture entrained
in the flow will bring just a slight chance for an afternoon or
evening shower or thunderstorm to the mountains. The primary
threats from any thunderstorms would again be lightning and gusty
winds. But this time around, the threat will be mainly north of
Highway 50 instead of south of it.
.LONG TERM...(Monday night through Sunday)
Issued at 325 PM MDT Sun Oct 9 2016
Not many adjustments required from previous meteorological
reasoning with primary longer term issues continuing to be
temperatures as well as generally low-grade to nil pops and
locally gusty winds at times.
Recent longer term computer simulations...forecast model
soundings and PV analysis continue to suggest that basically
zonal to southwesterly upper flow will continue over the forecast
district into next weekend with three relatively weak/fast moving
upper disturbances(per PV analysis...etc.) to contend with during
the longer term.
At the surface...eastern Colorado lee-side troughing is
anticipated from Monday evening into Tuesday with healthy
north-northeasterly to easterly surface surge impacting primarily
eastern portions of the forecast district Wednesday. Eastern
Colorado lee-side surface troughing then returns to eastern
Colorado from later Thursday into at least Saturday.
The highest potential of precipiation(including some higher
elevation light snow at times) should be noted from Tuesday into
Thursday and then again Saturday night with passing relatively
weak/quick moving upper level disturbances. Also...the highest
potential of gusty gradient winds is anticipated from Tuesday into
Tuesday night...Wednesday night and then again from Friday night
into Saturday.
It still appears that above seasonal mid-October minimum and
maximum temperatures should continue over the CWFA from Monday evening
into Wednesday morning with near to below seasonal temperatures
still expected from Wednesday afternoon into Thursday in advance
of warmer conditions returning from Friday into next weekend.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 325 PM MDT Sun Oct 9 2016
Upper disturbance near Four Corners Region will drift slowly east
across flight area this evening. System is currently bringing
precipitation to the San Juan Mountains. KDRO picked up at least
0.48 inches of rain today and has seen MVFR CIGS and VSBYS at times.
Webcams indicate rain and higher elevation snow has been falling
over the Cumbres and La Manga Pass areas at times, with the
surrounding peaks obscured in clouds and precipitation. Areas of
MVFR,IFR and LIFR flight conditions can be expected in precipitation
as this activity drifts eastward this evening. Could also be a few
thunderstorms this evening with primary threats of lightning, winds
gusting to around 40 mph and spotty heavy rainfall. Otherwise,
generally VFR across the flight area next 24 hours, including the
KCOS, KPUB and KALS TAF sites.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...MOZLEY
SHORT TERM...LW
LONG TERM...MOZLEY
AVIATION...LW
Area Forecast Discussion
National Weather Service San Diego CA
900 PM PDT SUN OCT 9 2016
.SYNOPSIS...
Patchy marine layer fog along the immediate coast is possible
tonight into Monday morning. Similarly hot in the mountains and
deserts Monday, but increasing onshore flow will bring cooler
conditions west of the mountains. Cooler for all areas Tuesday
through Wednesday with night and morning low clouds and fog
further into the coast and western valley areas. Stronger onshore
flow will also produce gusty west winds in the mountains and
deserts. Likely some warming on Thursday and Friday as high
pressure aloft builds, before cooler weather returns for next
weekend.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
Water vapor satellite this evening shows weak ridging over
Southern California with some upper level moisture still streaming
in from the west in the form of cirrus clouds. Today was likely the
hottest day of the week for inland areas, with highs reaching
5-10, locally 15, degrees above normal. Pressure gradients
continue to trend onshore, and dew points along the coast are
rising as well. This, in addition to increasing onshore flow
tonight, would indicate a better chance for dense fog/low clouds
to develop along the coast tonight. However, our local WRF and
the latest HRRR run show reduced visibilities mainly over the
coastal waters, with only a small patch or two near the southern
San Diego County coast.
Another hot day will occur in the mountains and deserts on
Monday, while strengthening onshore flow brings cooling to areas
west of the mountains as the ridge flattens across the region.
Cooling for all areas will occur Tuesday through Wednesday with
mainly zonal flow aloft and stronger onshore flow. This will also
result in a deepening of the marine layer and gusty west winds in
the mountains and deserts.
Thursday through Friday, the ridge to the south will likely build
and create a brief warming trend once again, with a shallower
marine layer. Another cool-down should commence next Saturday as a
trough deepens along the West Coast.
&&
.AVIATION...
100330Z...Coast...Small chance of low clouds along the immediate
coast tonight, with bases around 400 ft MSL and tops near 900 ft
MSL. Confidence is low in any of the coastal aerodromes developing a
ceiling. Otherwise SCT/BKN mid and high clouds tonight.
Valleys, Mountains and Deserts...SCT/BKN mid and high clouds
tonight. Unrestricted visibility and light winds will prevail
through Tue evening.
&&
.MARINE...
Very patchy fog, with a visibility of 1 NM or less, is possible over
the coastal waters late tonight through Monday morning. Otherwise,
no other hazardous marine weather is expected through Thursday.
&&
.SKYWARN...
Skywarn activation is not requested. However weather spotters are encouraged
to report significant weather conditions.
&&
.SGX Watches/Warnings/Advisories...
CA...None.
PZ...None.
&&
$$
PUBLIC...TS
AVIATION/MARINE...JJT
Area Forecast Discussion
National Weather Service Grand Forks ND
258 AM CDT Mon Oct 10 2016
.SHORT TERM...(Today and tonight)
Issued at 258 AM CDT Mon Oct 10 2016
Temperatures today and precipitation chances tonight will be the
main concerns for the period.
Southwesterly flow aloft will continue through today and tonight
as a positively tilted trough digs into the Northern Rockies. A
strong shortwave moving through Saskatchewan/Manitoba will help
push the surface trough and cold front into the CWA today. Surface
observations show the winds have just started to shift to the
northwest in the far northwestern counties, which fits the
HRRR/RAP/NAM solutions. These models all have the boundary into
the northern Red River Valley by sunrise, then continuing to push
southeast before slowing/stalling this afternoon. The front should
be stretching from the southwestern counties up towards Lake of
the Woods by this evening, although a few of the solutions such as
the experimental HRRR have the boundary further southeast. Even if
the front comes through Ransom and Sargent faster than expected,
with current temps in the 60s thanks to downslope off of the
Sisseton hills that area should have no problem getting into the
mid 70s. Further north, highs will be mainly in the 50s with 60s
between.
Tonight, the cold front will push the rest of the way through the
CWA. The models have a good signal for some precip developing over
the northeastern counties right around 00Z as mid level
frontogenesis gets going. The GFS, ECMWF, and Canadian all have
another band developing further west after midnight although the
NAM stays dry. So will keep the main area of precip over the
northeastern counties but will continue with some low POPs in the
Devils Lake Basin.
.LONG TERM...(Tuesday through Sunday)
Issued at 258 AM CDT Mon Oct 10 2016
Tuesday and Wednesday...The main upper low will be moving out into
the Northern Plains Tuesday and Tuesday night. With broad synoptic
lift and some mid level frontogenesis, there should be a good
chance for bands of light rain although exact placement is still
uncertain. Will continue to keep high chance POPs Tuesday
afternoon then tapering off from west to east Tuesday night. With
cold air advection throughout the day on Tuesday and the cold high
settling in Tuesday night, there could be some flakes mixing in on
the backside of the rain as temps fall from the 40s Tuesday to the
upper 20s and 30s Tuesday night. Not expecting any accumulation at
this point. Wednesday should be quiet and cool with high pressure
overhead. Temperatures will be similar to Tuesday with highs in
the 40s and lows in the upper 20s to low 30s.
For Thursday through Sunday....models in good agreement showing a
weak 500 mb ridge moving into the northern Plains. This will lead
to a warm up back to near or even above seasonal normals by Friday.
Next front due to move through Saturday, but the majority of the
moisture with this system to be south and east of our local region.
&&
.AVIATION...(For the 06Z TAFS through 06Z Monday night) Issued at
1118 PM CDT Sun Oct 9 2016
LLWS the concern at BJI and TVF in the overnight with 40 to 50 kt
LLJ and a decoupled SFC wind along the Valley and to the east.
CIGS maintain VFR until possibly near the end of the period as
winds turn to the northeast with FROPA tomorrow.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...None.
MN...None.
&&
$$
SHORT TERM...JR
LONG TERM...JR/Riddle
AVIATION...JK
Area Forecast Discussion
National Weather Service North Platte NE
308 AM CDT Mon Oct 10 2016
.SHORT TERM...(Today and tonight)
Issued at 308 AM CDT Mon Oct 10 2016
Today and Tonight...the models suggest a sunrise surprise this
morning with stratus forming after sunrise. Shallow mixing would be
the impetus for the formation of low clouds east of Ogallala to
Broken Bow. The SREF ceiling height probabilities for clouds below
3000 ft and 1000 ft spike at 15z and then vanish by 18z. Fog was
indicated along the dryline from Imperial to Ogallala.
The temperature forecast leans on the warmer ECS guidance plus bias
correction for highs in the upper 70s east to mid 80s west. The dry
line is expected to move east of highway 83 late this afternoon.
A Canadian cold front...currently across MT/ND should move into Nrn
Neb late tonight...after 06z. Stratus is expected along and behind
the front by Tuesday morning across Nrn Neb. Blend guidance plus
bias correction suggested lows mostly in the 40s. Very dry air would
remain in place across Western Nebraska supporting lows in the lower
40s.
.LONG TERM...(Tuesday through Sunday)
Issued at 308 AM CDT Mon Oct 10 2016
12z Tuesday and beyond. A cold front will be pushing across the
northwestern Sandhills early Tuesday...clearing the CWA by mid day.
A stark cooldown is expected behind the front as H85 temperatures
cool some 20-25 celsius in just 24 hours. Despite being a fairly
strong front it`s arrival should be fairly dry. The models hold off
on precipitation until late afternoon and evening Tuesday when large
scale forcing for precipitation arrives with the arrival of a
northern Rockies shortwave trough. The models are keying on the
development of showers along the mid-level front from generally the
west central Sandhills northeast through north central Nebraska.
Will maintain the highest pops in this area with lesser chances
elsewhere. Tropospheric profiles favor a changeover to snow across
northwest Nebraska as there is a fairly deep isothermal layer in the
-5 to -10C layer while decent omega is present with weak
instability. The best chances at seeing snow will be over northwest
Nebraska east through north central Nebraska. At this point
accumulations are unlikely due to a marginal sfc temperatures and
speed of the advancing system. The models key on rapid clearing
behind the advancing system...frost may be an issue Wednesday
morning over the northwestern third of the CWA. This area however
has seen a fairly stout freeze this Fall. Temperatures Wednesday
afternoon are forecast to be well below average. Highs in the 40s
to lower 50s appear likely. The models continue to trend downward
with these mid-week temperatures. Thursday through Friday a modest
warming trend is forecast as the upper levels transition to near
zonal. No precipitation is forecast owing to a lack of appreciable
omega. Temperatures stay mild into early next week as the zonal
pattern continues. A weak shortwave on Saturday may spark off a
shower or two...but at this point...chances are low.
&&
.AVIATION...(For the 06Z TAFS through 06Z Monday night)
Issued at 1152 PM CDT Sun Oct 9 2016
Expect clear skies over northern Nebraska and partly cloudy skies
over southern and central Nebraska over the next 24 hours. There
is a small threat for patchy fog which may impact the KLBF
terminal toward daybreak Monday. Decided to handle this with a
tempo group for 3sm. This is due to the abundance of mid and high
clouds expected overnight, which should keep visbys. from dropping
below 1sm. Winds will be from the south or southwest over the next
24 hours with speeds around 10 kts tonight-increasing to 10 to 20
kts on Monday.
&&
.FIRE WEATHER...
Issued at 308 AM CDT Mon Oct 10 2016
A check on the HRRR models...RAP and NAM indicates wing gusts
below 25 mph across Western Neb this afternoon. Only the GFS based
MOSGUIDE suggested gusts to around 25 mph. Winds at and below
700mb are 20 kts or less. Red Flag conditions are not expected
across Western Nebraska but relative humidity will fall to around
15 percent or less.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SHORT TERM...CDC
LONG TERM...Jacobs
AVIATION...Buttler
FIRE WEATHER...CDC
Area Forecast Discussion
National Weather Service Marquette MI
509 AM EDT Mon Oct 10 2016
.SHORT TERM...(Today and tonight)
Issued at 509 AM EDT MON OCT 10 2016
WV imagery and RAP analysis indicated a mid/upper level ridge from
the se CONUS to the central Great Lakes and a trough into the
pacific NW resulting in wsw flow through the nrn plains to the nrn
Great Lakes. A shortwave trough was located over wrn KS that
supported an area of shra/tsra over the cntrl plains. At the
surface, low pres was located over cntrl Manitoba with a cold front
into cntrl North Dakota. Southerly winds were increasing across the
Upper MS valley and nrn Great Lakes between the low and a ridge
sliding into the ern Great Lakes.
Today, waa and plenty of sunshine pushing mixing heights to around
900 mb (temps around 12C) will help boost temps well above normal
into the mid 60s. The strong pres gradient will result in winds
gusting into the 20-25 mph range.
Tonight, the combination of an approaching trough/front from the
west with increasing moisture advection, 300k-301k isentropic lift,
and a weak shrtwv lifting toward WI from the cntrl plains will
support increasing rain chances across the west half of Upper
Michigan, mainly aft 06z. However, overall pcpn should generally be
light with QPF of 0.10 inch or less.
.LONG TERM...(Tuesday through Sunday)
Issued at 414 AM EDT MON OCT 10 2016
Ahead of an upper trough, over the NW CONUS on Tue morning, SW flow
aloft and at the SFC will lead to shortwaves moving through Tue into
Tue night. This will bring chances for showers (and maybe some
thunder over the far W Tue Afternoon) Tue into Tue night. More
widespread rain is expected late Tue night and Wed as the upper
trough moves into the area and kicks a SFC low into the region,
dragging a cold front across the CWA.
NW low level flow and 850mb temps down to -5C will be sufficient for
lake effect Wed night into Thu, but invading SFC ridging will not
make for prime conditions for that lake effect. Precip will mostly
be rain, but some non-measurable snow is possible over the higher
terrain of the W.
Otherwise, Fri looks dry and there is a chance of rain for the
weekend. At this point, widespread rain looks likely late Sat and
Sat night.
&&
.AVIATION...(For the 06Z TAFS through 06Z Monday night)
Issued at 125 AM EDT MON OCT 10 2016
Expect llws at all the TAF sites this mrng with incrsg sly winds
above shallow radiation invrn. Some of the winds gusts could reach
the sfc at the more exposed IWD location. The stronger winds just
above this shallow radiation invrn wl mix out with daytime heating by
late this mrng and cause gusty winds in the evng. Since the incrsg
sly flow wl not tap any moist llvl air thru the TAF period, expect
VFR conditions this fcst period even though hi clds wl be on the
increase by this evng.
&&
.MARINE...(For the 4 AM Lake Superior forecast issuance)
Issued at 509 AM EDT MON OCT 10 2016
SW winds will increase to 30 kts today and tonight ahead of a low
pressure system then shift to the northwest to 20-30 kts behind the
system on Wed/Thu.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
None.
Lake Michigan...
None.
&&
$$
SHORT TERM...JLB
LONG TERM...Titus
AVIATION...KC
MARINE...JLB
Area Forecast Discussion
National Weather Service Bismarck ND
912 AM CDT Mon Oct 10 2016
.UPDATE...
Issued at 909 AM CDT Mon Oct 10 2016
A look at area webcams shows that most of the fog has diminished
over southwest North Dakota so will back coverage off to patchy,
and only keep it in for another couple hours. Also, cloud
coverage has become more widespread, with a broad area of low
clouds stretching down portions of the James River Valley into
portions of south central North Dakota. This has been addressed in
morning update.
UPDATE Issued at 624 AM CDT Mon Oct 10 2016
At 6 am CDT a cold front was moving slowly through the state. As
cold air was filling in behind the front an area of lower clouds
extended from Williston to near Dickinson. The HRRR model has
been consistently moving this area south through the region with
the leading patch of cool air. By mid morning the clouds will be
south of the state leaving partly to mostly sunny conditions south
and east and cloudy north. Latest HRRR keeps a very limited chance
for rain northwest today. Current forecast ok with minot
adjustments to clouds and rain chances.
&&
.SHORT TERM...(Today and tonight)
Issued at 241 AM CDT Mon Oct 10 2016
A cold front currently across central North Dakota will slowly
slide southeast tonight through the day. Isolated rain showers
will continue across far northwest North Dakota through the
morning hours. A significant baroclinic zone will set up across
North Dakota today. Highs will range from the upper 30s northwest
to lower 70s southeast.
Tonight, light rain or snow is possible as an upper level wave
moves across the region. Temperatures should be cool enough to
produce snow across western North Dakota, while central and
eastern North Dakota should remain warm enough keep it all rain.
During the early morning hours of Tuesday forecast soundings are
hinting at a chance for light freezing drizzle across northwest
North Dakota as there doesn`t appear to be any ice crystal
formation due to a dry layer aloft.
.LONG TERM...(Tuesday through Sunday)
Issued at 241 AM CDT Mon Oct 10 2016
Minor snow accumulations, an inch or less, are possible across
southwest North Dakota where temperatures should remain near
freezing through the night and into the morning hours Tuesday.
Elsewhere, expect colder air with lower to mid 40s in south
central North Dakota Tuesday afternoon. Soundings indicate that
rain mixing in with snow at times even into south central North
Dakota Tuesday evening. Precipitation will come to an end Tuesday
night with a cold northwest flow Wednesday. Highs Wednesday will
remain cool with readings in the low 40s.
Thursday through Sunday, a west to southwest flow aloft and
southerly return flow will bring warmer temperatures to the
region. Highs in the 60s are expected by the end of the week.
&&
.AVIATION...(For the 12Z TAFS through 12Z Tuesday morning)
Issued at 624 AM CDT Mon Oct 10 2016
At 6 am cdt a cold front extended from near Grand Forks to
Mobridge SD moving southeast. Areas of MVFR/IFR extended from
KISN-KDIK with vfr elsewhere. By 15-16z this area of low clouds
will move south and TAFs should be VFR until MVFR returns KISN-
KMOT after 04z.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JJS
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...WAA
Area Forecast Discussion
National Weather Service Grand Forks ND
940 AM CDT Mon Oct 10 2016
.UPDATE...
Issued at 938 AM CDT Mon Oct 10 2016
Main challenge through the day will be timing of slow moving cold
front and related temperatures across the FA. Front currently in
line with current forecast trends bisecting the FA from NE to SW.
Made some minor temperature and cloud cover adjustments but
overall current forecast good.
UPDATE Issued at 640 AM CDT Mon Oct 10 2016
A few spots right along the trough axis, currently across the
central CWA, have gone calm in winds and temps have dropped down
to the upper 30s. Think they should come back up quickly as winds
pick back up and things mix out.
&&
.SHORT TERM...(Today and tonight)
Issued at 258 AM CDT Mon Oct 10 2016
Temperatures today and precipitation chances tonight will be the
main concerns for the period.
Southwesterly flow aloft will continue through today and tonight
as a positively tilted trough digs into the Northern Rockies. A
strong shortwave moving through Saskatchewan/Manitoba will help
push the surface trough and cold front into the CWA today. Surface
observations show the winds have just started to shift to the
northwest in the far northwestern counties, which fits the
HRRR/RAP/NAM solutions. These models all have the boundary into
the northern Red River Valley by sunrise, then continuing to push
southeast before slowing/stalling this afternoon. The front should
be stretching from the southwestern counties up towards Lake of
the Woods by this evening, although a few of the solutions such as
the experimental HRRR have the boundary further southeast. Even if
the front comes through Ransom and Sargent faster than expected,
with current temps in the 60s thanks to downslope off of the
Sisseton hills that area should have no problem getting into the
mid 70s. Further north, highs will be mainly in the 50s with 60s
between.
Tonight, the cold front will push the rest of the way through the
CWA. The models have a good signal for some precip developing over
the northeastern counties right around 00Z as mid level
frontogenesis gets going. The GFS, ECMWF, and Canadian all have
another band developing further west after midnight although the
NAM stays dry. So will keep the main area of precip over the
northeastern counties but will continue with some low POPs in the
Devils Lake Basin.
.LONG TERM...(Tuesday through Sunday)
Issued at 258 AM CDT Mon Oct 10 2016
Tuesday and Wednesday...The main upper low will be moving out into
the Northern Plains Tuesday and Tuesday night. With broad synoptic
lift and some mid level frontogenesis, there should be a good
chance for bands of light rain although exact placement is still
uncertain. Will continue to keep high chance POPs Tuesday
afternoon then tapering off from west to east Tuesday night. With
cold air advection throughout the day on Tuesday and the cold high
settling in Tuesday night, there could be some flakes mixing in on
the backside of the rain as temps fall from the 40s Tuesday to the
upper 20s and 30s Tuesday night. Not expecting any accumulation at
this point. Wednesday should be quiet and cool with high pressure
overhead. Temperatures will be similar to Tuesday with highs in
the 40s and lows in the upper 20s to low 30s.
For Thursday through Sunday....models in good agreement showing a
weak 500 mb ridge moving into the northern Plains. This will lead
to a warm up back to near or even above seasonal normals by Friday.
Next front due to move through Saturday, but the majority of the
moisture with this system to be south and east of our local region.
&&
.AVIATION...(For the 12Z TAFS through 12Z Tuesday morning)
Issued at 640 AM CDT Mon Oct 10 2016
VFR conditions at all TAF sites. The cold front has already passed
through KDVL and should be moving through KGFK shortly, moving
further south and east before stalling just south of KFAR and KTVF
later this afternoon. Winds behind the front will be north to
northeast, eventually becoming northwest later tonight and picking
up to 12 to 15 kts. Some lower VFR to MVFR ceilings are possible
in some areas towards the end of the period. For now just have
KBJI going down to MVFR with around 3500 ft ceilings elsewhere.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...None.
MN...None.
&&
$$
UPDATE...Voelker
SHORT TERM...JR
LONG TERM...JR/Riddle
AVIATION...JR
Area Forecast Discussion
National Weather Service North Platte NE
723 AM CDT Mon Oct 10 2016
.UPDATE...
Issued at 723 AM CDT Mon Oct 10 2016
Dense fog is underway around Imperial. The dense fog has advisory
has been extended south through Chase and Perkins counties.
UPDATE Issued at 652 AM CDT Mon Oct 10 2016
Areas of dense fog are underway across Keith county in and around
Searle airport...aka KOGA. A dense fog adisory has been issued
for Keith County.
&&
.SHORT TERM...(Today and tonight)
Issued at 308 AM CDT Mon Oct 10 2016
Today and Tonight...the models suggest a sunrise surprise this
morning with stratus forming after sunrise. Shallow mixing would be
the impetus for the formation of low clouds east of Ogallala to
Broken Bow. The SREF ceiling height probabilities for clouds below
3000 ft and 1000 ft spike at 15z and then vanish by 18z. Fog was
indicated along the dryline from Imperial to Ogallala.
The temperature forecast leans on the warmer ECS guidance plus bias
correction for highs in the upper 70s east to mid 80s west. The dry
line is expected to move east of highway 83 late this afternoon.
A Canadian cold front...currently across MT/ND should move into Nrn
Neb late tonight...after 06z. Stratus is expected along and behind
the front by Tuesday morning across Nrn Neb. Blend guidance plus
bias correction suggested lows mostly in the 40s. Very dry air would
remain in place across Western Nebraska supporting lows in the lower
40s.
.LONG TERM...(Tuesday through Sunday)
Issued at 308 AM CDT Mon Oct 10 2016
12z Tuesday and beyond. A cold front will be pushing across the
northwestern Sandhills early Tuesday...clearing the CWA by mid day.
A stark cooldown is expected behind the front as H85 temperatures
cool some 20-25 celsius in just 24 hours. Despite being a fairly
strong front it`s arrival should be fairly dry. The models hold off
on precipitation until late afternoon and evening Tuesday when large
scale forcing for precipitation arrives with the arrival of a
northern Rockies shortwave trough. The models are keying on the
development of showers along the mid-level front from generally the
west central Sandhills northeast through north central Nebraska.
Will maintain the highest pops in this area with lesser chances
elsewhere. Tropospheric profiles favor a changeover to snow across
northwest Nebraska as there is a fairly deep isothermal layer in the
-5 to -10C layer while decent omega is present with weak
instability. The best chances at seeing snow will be over northwest
Nebraska east through north central Nebraska. At this point
accumulations are unlikely due to a marginal sfc temperatures and
speed of the advancing system. The models key on rapid clearing
behind the advancing system...frost may be an issue Wednesday
morning over the northwestern third of the CWA. This area however
has seen a fairly stout freeze this Fall. Temperatures Wednesday
afternoon are forecast to be well below average. Highs in the 40s
to lower 50s appear likely. The models continue to trend downward
with these mid-week temperatures. Thursday through Friday a modest
warming trend is forecast as the upper levels transition to near
zonal. No precipitation is forecast owing to a lack of appreciable
omega. Temperatures stay mild into early next week as the zonal
pattern continues. A weak shortwave on Saturday may spark off a
shower or two...but at this point...chances are low.
&&
.AVIATION...(For the 12Z TAFS through 12Z Tuesday morning)
Issued at 634 AM CDT Mon Oct 10 2016
Local LIFR in fog is underway from KIML to KOGA to KAIA including
parts of the western Sandhills. VFR is expected from 14z onward.
MVFR/IFR cigs in stratus may develop 13z-14z this morning from
KMCK-KLBF-KTIF and east. VFR is expected from 16z onward if these
cigs develop. Confidence is low with this feature.
VFR is expected all areas from 16z this morning to 09z tonight.
Thereafter...a cold front...currently located across northeast
WY/northwest SD will move into northern Nebraska. MVFR cigs are
expected along and behind the front.
&&
.FIRE WEATHER...
Issued at 308 AM CDT Mon Oct 10 2016
A check on the HRRR models...RAP and NAM indicates wing gusts
below 25 mph across Western Neb this afternoon. Only the GFS based
MOSGUIDE suggested gusts to around 25 mph. Winds at and below
700mb are 20 kts or less. Red Flag conditions are not expected
across Western Nebraska but relative humidity will fall to around
15 percent or less.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
Dense Fog Advisory until 9 AM MDT this morning for NEZ057-058-
069.
&&
$$
UPDATE...CDC
SHORT TERM...CDC
LONG TERM...Jacobs
AVIATION...CDC
FIRE WEATHER...CDC
Area Forecast Discussion
National Weather Service Marquette MI
752 AM EDT Mon Oct 10 2016
.SHORT TERM...(Today and tonight)
Issued at 509 AM EDT MON OCT 10 2016
WV imagery and RAP analysis indicated a mid/upper level ridge from
the se CONUS to the central Great Lakes and a trough into the
pacific NW resulting in wsw flow through the nrn plains to the nrn
Great Lakes. A shortwave trough was located over wrn KS that
supported an area of shra/tsra over the cntrl plains. At the
surface, low pres was located over cntrl Manitoba with a cold front
into cntrl North Dakota. Southerly winds were increasing across the
Upper MS valley and nrn Great Lakes between the low and a ridge
sliding into the ern Great Lakes.
Today, waa and plenty of sunshine pushing mixing heights to around
900 mb (temps around 12C) will help boost temps well above normal
into the mid 60s. The strong pres gradient will result in winds
gusting into the 20-25 mph range.
Tonight, the combination of an approaching trough/front from the
west with increasing moisture advection, 300k-301k isentropic lift,
and a weak shrtwv lifting toward WI from the cntrl plains will
support increasing rain chances across the west half of Upper
Michigan, mainly aft 06z. However, overall pcpn should generally be
light with QPF of 0.10 inch or less.
.LONG TERM...(Tuesday through Sunday)
Issued at 414 AM EDT MON OCT 10 2016
Ahead of an upper trough, over the NW CONUS on Tue morning, SW flow
aloft and at the SFC will lead to shortwaves moving through Tue into
Tue night. This will bring chances for showers (and maybe some
thunder over the far W Tue Afternoon) Tue into Tue night. More
widespread rain is expected late Tue night and Wed as the upper
trough moves into the area and kicks a SFC low into the region,
dragging a cold front across the CWA.
NW low level flow and 850mb temps down to -5C will be sufficient for
lake effect Wed night into Thu, but invading SFC ridging will not
make for prime conditions for that lake effect. Precip will mostly
be rain, but some non-measurable snow is possible over the higher
terrain of the W.
Otherwise, Fri looks dry and there is a chance of rain for the
weekend. At this point, widespread rain looks likely late Sat and
Sat night.
&&
.AVIATION...(For the 12Z TAFS through 12Z Tuesday morning)
Issued at 752 AM EDT MON OCT 10 2016
An increasing pres gradient and daytime mixing will result in gusty
srly winds today. Since the increasing srly flow will not tap any
moist llvl air through this evening, expect VFR conditions even
though high clouds will be on the increase by this evening. Late
tonight, some rain showers may develop but confidence is low that it
will drop conditions blo vfr.
&&
.MARINE...(For the 4 AM Lake Superior forecast issuance)
Issued at 509 AM EDT MON OCT 10 2016
SW winds will increase to 30 kts today and tonight ahead of a low
pressure system then shift to the northwest to 20-30 kts behind the
system on Wed/Thu.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
None.
Lake Michigan...
None.
&&
$$
SHORT TERM...JLB
LONG TERM...Titus
AVIATION...JLB
MARINE...JLB
Area Forecast Discussion
National Weather Service Las Vegas NV
840 AM PDT MON OCT 10 2016
.SYNOPSIS...Mild early October weather is expected over the region
through the week with high clouds moving overhead at times.
&&
.UPDATE...Thicker cloud cover which developed in the lee of the
southern Sierra Nevada over northern Inyo/Esmeralda Counties
overnight is starting to lift north based on satellite. However,
satellite shows more high clouds upstream over California and the
eastern Pacific.
Going to update and remove mention of thunderstorms over northeast
Mohave County this afternoon as new 12z NAM and HRRR show nothing
due to the lack of instability. No other updates needed.
&&
.PREV DISCUSSION...238 AM PDT MON OCT 10 2016
.Short Term...through Wednesday night.
An eastern Pacific trough and associated 90 kt jet produced a batch
of high clouds across much of the area overnight with additional
high clouds possible through the day as the trough inches closer to
the west coast. The ECMWF and GFS generate light QPF over
northeastern Mohave County this afternoon where weak instability is
forecast. Hi resolution models are dry for today. Decided to leave a
slight chance of showers in this area but removed any mention of
showers over the Sierra with model stability progs forecasting
stable conditions. Today will be a warm day under southwesterly flow
with high temperatures rising to 6-8 degrees above normal. Winds are
expected to be in the 10-15 mph range this afternoon with gusts to
around 20 mph possible.
The trough weakens as it moves into the area Tuesday leaving skies
mostly sunny and temperatures a couple of degrees cooler than
Monday. Winds will be light over the southern Great Basin with
southwesterly winds 10-15 mph continuing across the Mojave Desert.
High clouds may be on the increase again as another weak Pacific
trough approaches the west coast Tuesday night and then moves over
the area Wednesday. Models do not generate any QPF with this one
however some weak instability is forecast over northeastern Mohave
County. Will see how today plays out before adding any mention of
showers to the forecast for Wednesday. With the trough over the area
Wednesday, expect temperatures to ease back closer to normal.
.LONG TERM...Thursday through Sunday.
Model agreement is pretty good through Sunday with some differences
just starting to show up after Sunday. A large upper low will be off
the Pacific Northwest coast Thursday and Thursday night with a dry
westerly flow over our forecast area. Above normal temperatures are
expected with fairly light winds and some high clouds. The upper low
will move inland Friday and Friday night with a shortwave trough
racing through the base of the low across Nevada into Utah. This
will bring a chance of rain and snow showers to the Sierra Friday
afternoon and evening but it looks like any moisture east of the
Sierra will remain north of the CWA. This shortwave will bring some
breezy to windy conditions to the area but no significant
temperatures trends. A dry southwest to westerly flow will be over
the area Saturday and Sunday as another upper low moves toward the
Pacific Northwest. This will lead to some high clouds, locally
breezy conditions and above normal temperatures.
&&
.AVIATION...For McCarran...Mainly light winds following typical
diurnal trends are expected this morning. Southwest winds will
increase across the valley after 20z today, with gusts to around 20
kts possible. VFR conditions through the period.
For the rest of southern Nevada...northwest Arizona...and southeast
California...Occasional high clouds and increasing south to
southwest winds today with gusts up to 25 mph possible. VFR
conditions expected through the period.
&&
.SPOTTER INFORMATION STATEMENT...Spotter activation is not
anticipated this week however spotters are encouraged to report any
significant weather according to standard operating procedures.
&&
$$
Update...Pierce
Short Term/Aviation...Salmen
Long Term...Harrison
For more forecast information...see us on our webpage:
http://weather.gov/lasvegas or follow us on Facebook and Twitter
Area Forecast Discussion
National Weather Service La Crosse WI
226 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 18Z TAFS through 18Z Tuesday afternoon)
Issued at 1215 PM CDT Mon Oct 10 2016
Nice little short wave trough seen in the water vapor imagery near
Topeka at 17z, moving northeast toward the region. Expect
thickening and lowering clouds for the TAF locations through the
afternoon, and despite meager available moisture, there will
probably be some showers around. Indeed radar loops show light
showers advancing northward through IA. Have added some VCSH and
-SHRA to the TAFs for this evening and into the overnight hours.
Do not expect any worse than MVFR conditions at this point. Rain
risk should be gone before sunrise Tuesday. Another chance for
rain as a cold front sweeps in Tuesday night, but that is well
beyond this forecast period. Southerly wind will be a bit gusty
this afternoon into evening, especially near showers.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
IA...None.
&&
$$
SHORT TERM...ROGERS
LONG TERM...ROGERS
AVIATION...MW