Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 03/24/18
Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
1157 PM EDT Fri Mar 23 2018
.AVIATION...
High pressure anchored over northern Ontario will sustain northeast
flow across the area throughout the TAF period. This will generally
maintain a dry low level environment, supporting predominant VFR
conditions. Small window does exist Saturday morning for some degree
of MVFR stratus development given the prevailing cold flow off Lake
Huron. Greater inland penetration of this moisture will be limited
given the existing deep dry layer, but some potential remains mainly
at MBS late morning. Any emerging stratus should progressively
scatter out under daytime mixing by afternoon. Northeast winds
increasing to 10-15 kts during the daylight period.
/DTW THRESHOLD PROBABILITIES...
* None
&&
.PREV DISCUSSION...
Issued at 404 PM EDT Fri Mar 23 2018
DISCUSSION...
Combination of high amplitude midlevel ridge from the central Plains
northward through Canada and well defined upper level confluence
will lead to surface high pressure over the the Great Lakes this
weekend. Deep, persistent anticyclonic flow lower column cold air
advection, promoting very stable conditions from approximately 2.5
to 20 kft agl over southeastern Michigan. Impressive stability and
amount of dry air as RAP soundings suggesting that PWATs will be as
low as 0.07 inch by Saturday evening. Omega blocking will take root
throughout the weekend with geopotential heights ballooning to the
northeast through Hudson Bay. This will actually cause some
retrograding of the surface ridge back into the state to close out
the weekend.
Low impact weather for Saturday as tight area of deformation will
remain south of Southeast Michigan. This will keep the low track and
precipitation over southern Indiana. Good bet for high cloud veil to
extend northward south of I 96 corridor, but uncertainty exists on
opacity of the cloud. Solid northeast flow directly into the state
will lead to little movement on temperatures. Highs will range in
the lower 40s for much of the area, lower 30s in the Thumb.
Surface and midlevel ridge axes will remain back in place over
Michigan Sunday. Cold anomaly is shown to advect into eastern
portions of the area while undergoing heavy modification. Despite
what should be again full insolation, temperatures will likely be a
few degrees colder particularly for the far eastern areas. Highs
Sunday will be in the 30s to near 40 degrees.
High pressure departing eastward on Monday will maintain one final
day of dry conditions. Meanwhile, an upper level ridge axis crossing
the region will bring increasing southerly flow through the day
allowing highs to make a run for the low 50s. A string of
disturbances ejecting out of a longwave trough over the Western US
along with increasing moisture under deep southerly flow will bring
the next chance of widespread rainfall to the region early Tuesday
through early Wednesday. A frontal boundary crossing the region
Wednesday will then end rainfall as a push of slightly drier air
arrives late Wednesday. Mild conditions look to continue through
midweek with highs in the low to mid 50s. Will then need to monitor
the potential for another round of precipitation late next week as a
southern stream wave ejects out of the Southwest US while a northern
stream wave brings a push of colder air to the region.
MARINE...
Strong high pressure over James Bay tonight will maintain northeast
winds of 15 to 25 knots over Lake Huron right through Saturday
night, with winds just modestly decreasing on Sunday. Elevated waves
in excess of 4 feet will persist over much of southern Lake Huron,
and small craft advisories remain in effect.
High pressure reaching the East Coast early next week will allow
winds to shift to the southeast and increase, with gusts approaching
gale force over the open waters of Lake huron as a frontal boundary
moves through during the mid week period.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
Lake Huron...Small Craft Advisory until noon EDT Sunday for LHZ421-441>443.
Small Craft Advisory from 8 AM Saturday to noon EDT Sunday for
LHZ422.
Lake St Clair...NONE.
Michigan waters of Lake Erie...NONE.
&&
$$
AVIATION.....MR
DISCUSSION...CB/JD
MARINE.......CB
You can obtain your latest National Weather Service forecasts online
at www.weather.gov/detroit.
Area Forecast Discussion
National Weather Service Sioux Falls SD
654 PM CDT Fri Mar 23 2018
.UPDATE...
Issued at 646 PM CDT Fri Mar 23 2018
Radar filling in dramatically at this time lending confidence to
the winter headlined areas. Southwest MN still looks to run the
biggest risk of accumulating snowfall as the precipitation works
its way eastward during the mid and late evening hours. Will watch
for the possibility of thunder snow in southwest MN and extreme
northwest IA which could really enhance snow rates briefly.
However, indications off of the latest RAP and NAM show elevated
MU CAPE values greatly decreasing between 00Z and 02Z, and remain
in our southern zones across the southern half of the rain shield.
Soundings also indicate that there could be some sleet mixed in
with the rainfall under the higher reflectivity returns this
evening. Interesting how the 12Z simulated comp reflectivity off
of the ARW and NMM are actually quite accurate right now. Both of
their 00Z reflectivity prognosis have the heavier returns very
close to the MO River valley, which is not too far south of where
the current activity is. The HRRR and experimental HRRR have been
struggling with this precip, although the latest HRRR has
improved.
&&
.SHORT TERM...(This evening through Saturday)
Issued at 341 PM CDT Fri Mar 23 2018
Forecast broadly remains on track for the CWA. Open wave currently
ejecting off the Rocky Mountains will translate eastward this
afternoon along the nose of an upper jet, bringing broad lift to the
region. This lift will interact with a frontogenetic layer around
850mb to lead to widespread precipitation by 00z. Main source of
uncertainty with the precipitation remains type, as surface
temperatures will be around 32 degrees as precipitation begins.
Temperatures have remained cool into the early part of the afternoon
so am not worried about rain failing to switch over to snow. Snow to
liquid ratios remain low as -12C heights look to be around 15kft,
which supports a wet snow solution. Main tweak to the forecast was
delaying the onset of precipitation and lowering amounts slightly in
deference to the relatively dry easterly flow that is ongoing today.
Snow amounts will remain robust in southwest Minnesota as a quick
changeover to snow is expected. The wild card is potential
convection in southwest Minnesota. Progged soundings show elevated
CAPE at or less than 50 J/kg that is spotty both spatially and
temporally. While the trend has been away from getting convective
snows, will stick with winter storm warning despite borderline snow
amounts, just in case.
Saturday will be cold as cloud cover lingers across the region.
Expect the fresh snowfall over southwest Minnesota to reinforce
their cold bias from the past several weeks.
.LONG TERM...(Saturday night through Friday)
Issued at 341 PM CDT Fri Mar 23 2018
While most of the focus of this forecast update was the impending
snowfall tonight, there is one highlight in the extended period.
Next chance for precip comes courtesy of advection driven lift and
an inverted trough on Monday. Precipitation type looks to be an
issue with this as well, with a warm nose aloft around 850mb and
the layer isn`t always saturated above -10C. This will bring
chances for freezing rain in addition to snow and rain.
The CWA will be affected for the remainder of the extended periods
by large scale troughing aloft, leading to temperatures at or below
normal. Multiple southern stream impulses far to our south will cut
off most of our access to moisture, leaving only scant chances for
precipitation after Tuesday.
&&
.AVIATION...(For the 00Z TAFS through 00Z Saturday evening)
Issued at 646 PM CDT Fri Mar 23 2018
Strong storm system lifting eastward will provide plenty of IFR to
MVFR conditions tonight, lasting right into Saturday. Tonight, we
are dealing with both lowered visibilities and ceilings in rain
and snow. Even TSRA at KFSD and KSUX is a threat early this
evening. Late tonight, some light freezing drizzle is a threat for
KFSD lasting through early Saturday. On Saturday, MVFR ceilings
will likely linger all day. The easterly fetch of winds will
decrease tonight, but will remain quite strong Friday evening with
frequent gusts of 25 to 35 knots.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...Winter Weather Advisory until 10 AM CDT Saturday for SDZ040-056.
MN...Winter Weather Advisory until 10 AM CDT Saturday for MNZ089-097-
098.
Winter Storm Warning until 10 AM CDT Saturday for MNZ071-072-080-
081-090.
IA...Winter Weather Advisory until 10 AM CDT Saturday for IAZ002-014.
Winter Storm Warning until 10 AM CDT Saturday for IAZ003.
NE...None.
&&
$$
UPDATE...MJ
SHORT TERM...Ferguson
LONG TERM...Ferguson
AVIATION...MJ
Area Forecast Discussion
National Weather Service Green Bay WI
1027 PM CDT Fri Mar 23 2018
Updated aviation portion for 06Z TAF issuance
.SHORT TERM...Tonight and Saturday
Issued at 248 PM CDT Fri Mar 23 2018
The latest RAP analysis and satellite/radar imagery show high
pressure stretching from Hudson Bay, across the western Great
Lakes, and to the Gulf Coast early this afternoon. Dry air
emanating out of the high is supporting falling humidities into
the 20 to 25 pct range over central and north-central WI. Meanwhile,
warm advection is occurring over the central to the northern
Plains, which is generating an arcing band of rain and snow from
North Dakota to Missouri. As this storm system slides southwest of
the region tonight, temperatures and humidities are the main
forecast concerns.
Tonight...Precipitation will continue to shift southeast across
Minnesota, Iowa, and Illinois. Slight cold advection will be
occurring further north across Wisconsin, with a tight pressure
gradient generating breezy northeast to east winds. Will have some
cirrus invade the region from the west on the edge of the storm
system, but think far NE WI will remain mostly clear through much
of the night. The combo of cirrus and breezy winds off the Lake
should lead to a warmer night at most locations. Low temps ranging
from the low to mid teens over Vilas county to the middle or upper
20s over the southern Valley and Lakeshore.
Saturday...The Hudson Bay high will continue to be dominant across
northern Wisconsin. A blanket of cirrus will persist over central
and east-central WI, on the northern fringes of the slow moving
storm system. Under filtered sunshine, gusty east winds will make
temperatures in the middle 30s to near 40 feel colder. Humidities
are forecast to not fall as far as they did today, and bottom out
in the 27-37 pct range over central to far northeast WI.
.LONG TERM...Saturday Night Through Friday
Issued at 248 PM CDT Fri Mar 23 2018
Mean flow to remain amplified, but slowly progressive next week.
The main features to consist of: an eastern Pacific upper ridge,
an eastward moving longwave trough across the CONUS and an east-
ward moving upper ridge from the eastern CONUS into the western
Atlantic. The main system of interest remains from Monday
afternoon through Tuesday night as a cold front slowly pushes
through WI, accompanied by a couple waves of low pressure. There
will be other small precipitation chances later next week as the
longwave trough arrives. Temperatures are expected to go above
normal early next week as the mean flow turns southwest.
Temperatures should then drop closer to normal by late week as the
flow turns northwest behind the trough.
High pressure over Quebec will extend southwest through the Great
Lakes into the Midwest Saturday night. Clear skies and diminishing
winds should bring yet another cold night to the region with min
temperatures around 10 above zero north-central WI, to the lower
20s across east-central WI. Quiet and seasonal conditions are
expected through Sunday as the region to remain on the southwest
flank of the high pressure. A slight wind shift from east-
northeast to east-southeast will also help raise temperatures a
bit. Under sunny skies, look for max temperatures to range from
the upper 30s to around 40 degrees near Lake MI/Bay of Green Bay,
mainly lower to middle 40s elsewhere although a couple sites west
of the Fox Valley could reach the upper 40s.
The high pressure is forecast to start losing its influence on our
weather Sunday night as a southwest flow aloft takes over the
central CONUS. Anticipate some increase in at least high clouds
into central WI after midnight, while eastern WI remains mostly
clear. The combination of these clouds and boundary layer winds at
around 30 knots will prevent temperatures from falling as far as
previous nights. Look for readings in the upper teens to lower 20s
far north, middle to upper 20s south. Clouds will continue to
thicken, overspread northeast WI on Monday as a new system
organizes over the central Plains. This system is expected to tap
gulf moisture and quickly transport this moisture into WI,
especially by the afternoon hours. The onset of WAA, combined with
pieces of shortwave energy moving through the southwest flow
aloft, will bring a chance of light rain to parts of northeast WI
primarily in the afternoon. Max temperatures to range from the
lower to middle 40s north/near Lake MI, middle to upper 40s south.
Precipitation will become more widespread Monday night as a cold
front pushes across the Upper MS Valley toward far western WI by
12z Tuesday. Plenty of moisture to be in place over WI with PW
values surpassing 1" over central/east-central WI. Not sure if we
have enough instability to justify carrying a thunder threat, but
will leave it in the forecast for now to avoid any yo-yo effect.
Precipitation type is also an issue as temperatures cool
overnight. Northern WI should see rain become mixed with snow
after midnight with the far north changing to all snow toward
daybreak. Any snow or mixed precipitation is expected to
transition back to rain Tuesday morning as temperatures warm. The
cold front is forecast to steadily move across the rest of WI on
Tuesday, thus higher end pops will continue over most of the
forecast area. As for thunder, there is better instability with a
little CAPE/LI`s approaching zero over east-central WI. Max
temperatures to range from the middle to upper 40s north/lakeside,
lower to middle 50s east-central WI.
Precipitation chances will continue into Tuesday evening over all
of northeast WI, then focuses more over eastern WI Tuesday night.
Precipitation type may be an issue once again depending on how
quick the precipitation diminishes and how fast cooler air pushes
into WI. Any lingering clouds in the east Wednesday morning should
quickly exit as a weak area of high pressure moves into the
western Great Lakes. Anticipate mostly sunny skies for most of the
day with max temperatures in the middle to upper 40s north/near
Lake MI, upper 40s to lower 50s south.
Another cold front is progged to push into the region Wednesday
night, however gulf moisture appears to be lacking due to a
stalled frontal boundary over the Gulf Coast states. Cannot
completely rule out a few rain and/or snow showers across
northeast WI later Wednesday night into Thursday. Models are
having timing issues with regards to a northern stream shortwave
trough Thursday night (ECMWF) or Friday (GFS). There is a pretty
good surge of CAA, along with mid-level forcing, but moisture is
again lacking. For now, have followed the model consensus which
brings a small chance of rain/snow showers to north-central WI on
Thursday, followed by a low-end chance pop for the entire forecast
area Thursday night. Max temperatures for late next week to be
near seasonal normals for late March.
&&
.AVIATION...for 06Z TAF Issuance
Issued at 1026 PM CDT Fri Mar 23 2018
The main aviation concern will be northeast winds, which will be
gusty at times, especially in east-central Wisconsin. Given the
very dry air at low-levels, will continue to downplay the
potential for any low clouds tomorrow morning.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......AK
AVIATION.......Skowronski
AREA FORECAST DISCUSSION...UPDATED
National Weather Service Jackson KY
1121 PM EDT Fri Mar 23 2018
.UPDATE...
Issued at 1115 PM EDT FRI MAR 23 2018
Not many adjustments have been made so far as recent guidance does
not support much in the way of change to the wintry precipitation
event upcoming other than the slow down the increase in pops prior
to 9Z. Temperatures in the higher terrain at Pike Co. Mesonet and
Harlan County Mesonet were running colder than the previous
forecast as were some of the eastern valleys where mid level
clouds have yet to thicken up. Hourly temperatures and dewpoints
were updated over the next few hours accordingly.
UPDATE Issued at 850 PM EDT FRI MAR 23 2018
Hourly grids have been adjusted based on recent observations and
trends for tonight. Clouds are gradually thickening and lowering
from southwest to northeast. With some lower clouds having moved
into parts of south central and middle TN. Some light rain has
been reported as close as KGLW. A few of the eastern valley
locations have experienced few if any mid level clouds so far and
have dropped off to around the 40 degree mark.
Taking a look at the upcoming event, not much in the way of
changes appear to be needed at this time. Looking at 18Z and
recent convective allowing models and making some slight
adjustments to hourly temperatures storm totals generally remained
very similar. Using smaller one hour time steps for snow to
liquid ratios and these hourly temperatures which are a tad cooler
int he north leads to a little less snow for upper end amounts in
northern Fleming, Rowan, and Elliott counties. For locations from
Estill to Letcher, this results in about half of an inch more
snow for Saturday morning. At this time, no changes are planned
for headlines, but each hourly run of HRRR will be evaluated for
any any need for changes. A refreshed WSW product and SPS will be
issued over the next couple of hours.
&&
.SHORT TERM...(This evening through Saturday night)
Issued at 444 PM EDT FRI MAR 23 2018
Extremely complex forecast as low pressure moves out of the
central plains and into the lower OH valley by Saturday evening.
Precipitation type is an extreme challenge as model soundings in
the north show some deep near freezing isothermal profiles, which
may hold through much of the day on Saturday. If such soundings
verify that could mean a very heavy wet clinging snow where even 3
or 4 inches may result in power outage problems. However, it also
means that just a degree temperature difference can result in a
very cold rain. With the trends of recent model runs, WPC guidance
and collaboration with neighboring office have opted to go with a
winter storm warning for our northern counties. Three to 5 inches
of snow is forecast for the warning area, but a few isolated 6 or
7 inch amounts cannot be ruled out. South and east of the warning
we continued the advisory, and also added a couple of counties to
the advisory.
There will be close to a 20 degree temperature spread from north
to the southwest part of the area on Saturday. And further south
some thunderstorms will be possible, mainly in the Cumberland
basin. Latest indications are that rainfall will be spread out
over a long enough time period that small stream flooding should
not be an issue. WPC also has not placed any of the area in the
excessive rainfall outlook. With that in mind have opted to not go
with a flood watch, which we had been considering earlier today.
However, a few points on the Cumberland river could reach flood
stage sometime on Sunday.
.LONG TERM...(Sunday through Friday)
Issued at 111 PM EDT FRI MAR 23 2018
The long term portion of the forecast will feature a deepening
upper level trough over the western U.S. early next week, with
deep southwest flow becoming established across the OH and TN
valleys. By the end of the week the trough will shift east, but
with southwest flow across the eastern U.S. continuing. There is
good model agreement with the overall upper air pattern though
some differences are to be expected with individual short waves
ejecting from the upper low that will be over the southwestern
part of the United States through the first half of next week.
With good model agreement with the overall pattern, the concern
for the coming week will be the potential for heavy rain somewhere
in the central to eastern U.S. with deep southwest flow becoming
established. Current indications are that the heaviest rains will
likely affect areas to our west early to mid week as a slow
moving front moves into the MS Valley. The front will eventually
move across our area during the second half of the week, but it is
possible it will stall again at some point near us or just to our
east. The greatest threat for heavy rains next week appears to be
over western KY and TN. While this is outside our forecast area
it is close enough that the coming week will need to be monitored
closely. Considering the heaviest rain potential is still 5 days
away or so, it is likely the forecast axis of heaviest rains will
shift during the coming days.
The southwest flow will also result in warming temperatures, with
above normal temperatures expected from Tuesday through at least
Thursday.
&&
.AVIATION...(For the 00Z TAFS through 00Z Saturday evening)
ISSUED AT 835 PM EDT FRI MAR 23 2018
VFR conditions will prevail for the first 6 to 9 hours of the
period, before deterioration to MVFR and then IFR for most
locations after 14Z. The IFR should then persist through the end
of the period as the lower levels saturate leading to low ceilings
with falling precipitation. Low pressure will move from the
central plains to the lower OH valley by Saturday evening. Clouds
will thicken and lower tonight with low level clouds moving into
the southwest part of the area during the next few hours and
advancing northeast ahead of the approaching system. Precipitation
should overspread the area between about 6Z and 13Z. Enough cold
air will remain in place over the northern part of the forecast
area that much of the precipitation will fall as snow or a rain
and snow mix Saturday morning for JKL, SYM, and SJS. Further
southwest just plain rain is expected. Some thunder will be
possible generally after 17Z, mainly at SME and LOZ.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
Winter Storm Warning until 2 AM EDT Sunday for KYZ044-050>052-
060-104-106.
Winter Weather Advisory until 2 AM EDT Sunday for KYZ059-107>110-
119-120.
&&
$$
UPDATE...JP
SHORT TERM...SBH
LONG TERM...SBH
AVIATION...JP
Area Forecast Discussion...UPDATED
National Weather Service North Platte NE
630 PM CDT Fri Mar 23 2018
.SYNOPSIS...
Issued at 339 PM CDT Fri Mar 23 2018
A high amplitude pattern continues across the CONUS
today as a ridge of high pressure extended from west Texas north
into western Saskatchewan. East of this feature, a trough of low
pressure extended from eastern Canada south to the outer banks of
North Carolina. West of the ridge, a closed low was present off the
coast of British Columbia with a trough extending south into the
eastern Pacific. Downstream of this feature, upper level
disturbances were present from northern Arizona into eastern
Montana. The leading edge of this energy had moved into western
Colorado as of midday with lightning strikes south of Grand Junction
CO to Cortez CO. At the surface, low pressure was present over east
central Colorado with a warm front extending east along the border
of Kansas and Nebraska. South of the front, temperatures had warmed
into the 60s and 70s this afternoon, while north of the front, winds
were easterly and temps were in the 50s to lower 60s.
&&
.SHORT TERM...(This evening through Saturday)
Issued at 339 PM CDT Fri Mar 23 2018
The primary forecast challenge through Saturday revolves around a
lee side surface low crossing the central Plains in conjunction with
a stout mid-level shortwave. Thunderstorms are possible this
evening, and then a notable cooldown is in store for Saturday.
This evening and tonight... The surface low pressure treks across
Kansas, reaching TOP by 06z, while the shortwave brushes northern
Neb. The triple point rides along the NE/KS border, which will be
the focus for potential severe storms. SPC RAP mesoanalysis
suggests the highest deep layer shear (up to 60kts) and modest
instability (up to 1000j/kg MUCAPE, 8C/km lapse rates) in the area
as of 20z. Primary threat will be hail given the elevated/cool
sector nature of the storms, but wind gusts can`t be ruled out if
some of the stronger flow aloft is transferred toward the surface.
Showers or general thunder coverage will extend into the Sandhills,
where moisture and speed convergence are helping precip develop
early this afternoon. Higher res model suites (RAP, HRRR, HREF) in
general agreement with the greatest coverage early evening, then
dissipating or being relegated to north central Neb by 06z. All
precip should be out of the area by morning when min temps are
achieved (upper 20s to mid 30s), negating the snow threat. However,
stratus will stick around northern Neb into the morning as strong
CAA takes over and trapping moisture in the lower levels. H85 temps
drop toward 0C by 12z in northerly flow.
Saturday... Dropped high temps a few degrees, especially across
north central Nebraska where northerly low level winds will be
strongest, thick cloud cover remains, and CAA continues into the
afternoon. Despite cool temps aloft, overall isentropic downglide
and drier air in the mid levels will limit precip chances. Farther
west toward the panhandle, return flow resumes in the afternoon and
H85 temps push 10C under mostly clear skies. Forecast highs range
from near 40F at ONL to near 60F at IML.
.LONG TERM...(Saturday night through Friday)
Issued at 339 PM CDT Fri Mar 23 2018
mid range...Saturday night through Monday...Low amplitude ridging
aloft will shift east of the forecast area Saturday evening. H5 flow
will transition to southwesterly, allowing a lee side surface trough
of low pressure to deepen along the front ranges of Colorado and
Wyoming. Southerly winds will increase overnight and surface low
pressure will begin to develop over eastern Colorado Sunday morning.
A warm front will extend east of the surface low, with an inverted
trough of low pressure extending north of the low across the
Nebraska Panhandle. East of the trough and north of the warm front,
cool easterly winds are expected and temperatures will struggle to
get out of the 40s Sunday. We may see some lower to middle 50s in
the eastern Panhandle INVOF of the inverted trough. Precipitation
chances will increase Sunday night as a lead disturbance lifts from
northeastern Colorado into northwestern Nebraska. As for Ptype
Sunday night, decided to keep most of the pcpn as all rain based on
the latest GFS soln. Will need to continue to monitor this however
as a downward shift of a few degrees, could result in accumulating
snows in the northwestern cwa Sunday night.
long term...Monday through Friday...Another shot of rain or snow
will track across the region Monday night in response to a northern
stream trough, which will track across the northern plains. Mainly
dry conditions are expected through the end of the work week,
however, temperatures will be below normal as a second cold front
tracks into the northern plains Wednesday night into Thursday.
&&
.AVIATION...(For the 00Z TAFS through 00Z Saturday evening)
Issued at 629 PM CDT Fri Mar 23 2018
Periods of light rain, heavier showers and isolated thunderstorms
are expected to exit wrn Nebraska around 05z this evening and
ncntl Nebraska around 12z Saturday. MVFR/IFR cigs are expected to
backfill ncntl Nebraska as the rain exits. MVFR cigs will likely
last through the afternoon along and east of highway 183 with VFR
west of highway 183.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SYNOPSIS...Buttler
SHORT TERM...Snively
LONG TERM...Buttler
AVIATION...CDC
Area Forecast Discussion
National Weather Service Marquette MI
619 PM EDT Fri Mar 23 2018
.SHORT TERM...(This evening through Saturday)
Issued at 413 PM EDT FRI MAR 23 2018
Water vapor imagery and RAP analysis show a ridge extending from the
Plains to central Canada and a trof over eastern N America. Result
is another day of nw flow over the Upper Great Lakes. Under a dry
air mass, it`s been another sunny day. However, there have been some
clouds off Lake Superior into a small part of n central Upper MI as
an area of shallow moisture and slightly colder air (a couple of C
drop at the inversion base) moved across the lake. Temps currently
range from the mid/upper 20s near Lake Superior to the mid/upper 30s
toward the MI/WI state line.
With loss of daytime heating, may see stratocu off the lake expand a
bit this evening into n central/nw Upper MI and perhaps spread well
inland under low-level ne to e winds. Could be bkn cloud cover
locally for a time. Overnight, winds veer more easterly which would
shift any lake stratocu to just mainly the Keweenaw. Otherwise, some
high clouds will gradually spread e into mainly western and s
central Upper MI. Cloud cover shouldn`t have a big impact on min
temps. Favored the lwr end of guidance since that has worked well in
recent days. Expect mins down into the single digits in the
interior, ranging up into the teens along the Great Lakes.
Another quiet day is on tap for Sat. There may be some morning
stratocu over the Keweenaw and perhaps also in Menominee county
under easterly flow. Otherwise, sun will be filtered by some high
clouds, especially w and s. Max temps will be similar to today,
ranging from around 30F near Lake Superior to near 40F toward the
MI/WI state line. There will be a cool ene wind.
.LONG TERM...(Saturday night through Friday)
Issued at 425 PM EDT FRI MAR 23 2018
The benign weather pattern that has been prevailing starts breaking
down toward the tail end of the weekend. Initially closed low over
the western through central Plains early next week becomes an open
wave as it approaches the U.P. Moisture out ahead of the approaching
system will pool into the region, allowing for precip chances to be
on the increase Monday into Tuesday. While snow looks probable at
the onset in the western U.P, precip type will transition over to
rain during the day Monday as temps rise well above the freezing
mark. As the temps drop back off toward freezing Monday night into
early Tuesday, a wintry mix looks more likely, with snow prevailing
over Lake Superior. Precip chances should clear out of the area late
Tuesday, although could remain a bit unsettled overall through the
end of the week.
&&
.AVIATION...(For the 00Z TAFS through 00Z Saturday evening)
Issued at 619 PM EDT FRI MAR 23 2018
VFR conditions are expected at KIWD/KCMX/KSAW thru this fcst period.
Some lake effect clouds are possible off Lake Superior at KSAW this
evening and at KCMX tonight into Sat morning. However, there is
uncertainty in coverage and location of cloud development, so only
sct clouds with bases around 2000ft were mentioned.
&&
.MARINE...(For the 4 PM Lake Superior forecast issuance)
Issued at 413 PM EDT FRI MAR 23 2018
Strong high pres over southern Hudson Bay will shift e, reaching
Quebec Sat and Sun. As this occurs, expect generally ne to e winds
of 15-25kt across Lake Superior tonight/Sat, except up to 30kt over
the far western part of the lake. Winds will then veer more e to se
on Sun with the stronger winds shifting to the eastern part of the
lake. Ahead of an approaching low pres trof, winds may reach up to
30kt at times over eastern Lake Superior Mon/Tue. Winds will be
lighter over the western part of the lake. Behind the trof, winds
should be under 20kt on Wed.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
None.
Lake Michigan...
None.
&&
$$
SHORT TERM...Rolfson
LONG TERM...lg
AVIATION...07
MARINE...Rolfson
Area Forecast Discussion
National Weather Service San Francisco Bay Area
855 PM PDT Fri Mar 23 2018
.SYNOPSIS...A cold front will spread rain from north to south
across much of the region tonight and Saturday morning. Additional
shower activity is forecast Saturday late afternoon and evening
with isolated showers possibly lingering into Sunday. Dry weather
is expected to return on Monday and continue through next week. A
warming trend is forecast for the first half of the week.
&&
.DISCUSSION...As of 8:55 PM PDT Friday...Satellite, radar, and
observations indicate that the cold front approaching from the
northwest is currently near Point Arena. Based on the latest HRRR
model, expect the cold front to spread rain across the North Bay
between about 10 pm and 2 am, then south across the rest of the SF
Bay Area between 2 am and 5 am Saturday, and finally through the
Monterey Bay Area between 5 am and 8 am. Several lightning strikes
have been detected along the northern California coast north of
Point Arena this evening, so a slight chance of thunderstorms have
been added to the North Bay for later this evening.
All of the models indicate little or no precipitation following
the front on Saturday until the cold upper low approaches late in
the day. Thus, most of Saturday may end up being dry under partly
cloudy skies. The evening forecast update included a reduction in
shower chances for most of Saturday.
Shower chances will increase late Saturday afternoon and evening
as the cold upper trough approaches the northern California coast.
Based on the 00Z models, shower chances will spread into our
forecast area from late Saturday afternoon into Saturday night.
But rainfall then is not expected to be as widespread as with the
cold front moving through tonight. There is also a slight chance
of thunderstorms late Saturday afternoon and early evening, mainly
across the North Bay where instability will be greatest.
Isolated showers may linger into Sunday, mainly near the coast in
the morning, and then along the eastern portion of our forecast
area in the afternoon. But for the most part Sunday is expected to
be a dry and cool day.
This incoming system will not have a whole lot of moisture to work
with and so rain totals from tonight through the weekend are
forecast to generally be a half inch or less, with highest amounts
in the North Bay. Some southern inland areas may see little, if
any, rainfall.
Snow levels will start off around 3500 feet tonight, but then drop
as low as 2500 feet by Saturday and Saturday night. Since the bulk
of the precipitation is expected to fall with the cold front
tonight and prior to the arrival of the coldest air, only light
snowfall accumulation is expected on the higher peaks.
Models continue to indicate dry weather through next week, along
with a warming trend, as a ridge of high pressure develops
offshore and then slowly moves eastward.
&&
.AVIATION...As of 04:39 PM PDT Friday...for 00Z TAFs. Currently
VFR conditions at all sites with scattered clouds and occasional
showers in the North Bay. A cold front is still expected to move
through late tonight bringing another round of steady showers. As
the front approaches expect cigs to begin to lower back to MVFR.
Shower chances will end early tomorrow morning once the front has
passed and VFR conditions should once again prevail.
Westerly winds will remain breezy through the evening at around 15
kt before taking a more southerly turn and somewhat decreasing.
Vicinity of KSFO...VFR anticipated through about 03z or so, with
FEW/SCT clouds between 3,000 to 5,000 ft AGL. Cigs expected to
lower to MVFR this evening, ahead of a cold front that is forecast
to pass through the terminal around 08-11z tonight. Models still
suggest a narrow band of rain as the cold front sweeps through.
Left a few hours of light rain in the tafs. Breezy southwesterly
winds expected to continue into tonight.
SFO Bridge Approach...Similar to KSFO.
Monterey Bay Terminals...VFR conditions through tonight. Cigs will
lower after midnight tonight, ahead of an approaching cold front
forecast to pass through early Saturday morning. Expect wet
runways from light rain as the front passes. Breezy westerly winds
will continue into the evening.
&&
.MARINE...As of 8:16 PM PDT Friday...Lightning strikes have been
observed off the Northern California coast near Fort Bragg.
There`s a slight chances of thunderstorms across the northern
waters over the next few hours. Light to moderate west to
southwest winds will prevail as a cold front makes its way through
the coastal waters late tonight. Light rain is possible along the
front, and winds will turn northwesterly in its wake. A second
cold front is expected Saturday evening into Sunday morning.
Northwest swell will increase slightly overnight tonight.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.Tngt...SCA...Pt Arena to Pt Reyes 0-10 nm
SCA...Pt Arena to Pigeon Pt 10-60 nm
SCA...SF Bay from 9 PM until 3 AM
SCA...Pt Reyes to Pigeon Pt 0-10 nm from 9 PM until 3 AM
&&
$$
PUBLIC FORECAST: Dykema
AVIATION: AS
MARINE: AS
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Area Forecast Discussion
National Weather Service Pueblo CO
619 PM MDT Fri Mar 23 2018
.UPDATE...
Issued at 616 PM MDT Fri Mar 23 2018
Winter weather, high wind and fire weather highlights all allowed
to expire for this evening. Conditions are no longer meeting
criteria. Regardless, fire danger remains high. Caution should
continue.
&&
.SHORT TERM...(This evening through Saturday)
Issued at 348 PM MDT Fri Mar 23 2018
...High Fire Danger returns to the I-25 corridor Saturday though
with slightly less wind...
Wind speeds appear to have peaked earlier this afternoon, as weak
line of convection under the upper trough moved off the mountains
and helped push gusts over 50 kts along much of the I-25 corridor,
with even a few 60 kt plus gusts near Colorado Springs and
Walsenburg. Surface obs and latest HRRR suggest winds are finally
beginning to lessen as of 21z, though will still keep the high wind
highlight in place into early evening, as gusts are still near 50
kts in places, and some weak convection still lurks west of
Trinidad, which may briefly enhance gusts along the srn I-25
corridor the next few hrs. Snow over the mountains was gradually
ending this afternoon, but will keep winter wx advisory up until
early evening to account for howling winds and blowing snow at/above
pass level. Winds diminish overnight as upper system lifts east and
cold front drops south through the plains, with speeds dropping
below 15 kts most locations by early Saturday morning.
On Saturday, S-SE return flow develops quickly over the plains, as
surface pressure begins to fall once again in the lee of the eastern
mountains. Certainly won`t be as windy as today, but with gusts in
the 20-30 mph range and humidity around 15 percent, upgrade of fire
wx watch to a Red Flag Warning looks warranted, mainly along and
just east of the I-25 corridor. Max temps will cool a few degf from
Friday`s rather toasty maxes, though most locations will end up
above late March averages, and some low to mid 70s will be likely
over the eastern plains.
.LONG TERM...(Saturday night through next Friday)
Issued at 348 PM MDT Fri Mar 23 2018
Relatively active conditions are expected to continue over the
forecast district during the balance of the longer term with
primary initial meteorological concerns being above seasonal
temperatures, gusty winds and critical fire weather conditions at
times into Monday, followed by cooled/unsettled conditions
developing over the majority of the CWA from Monday evening into
Thursday evening.
Outside of Continental Divide locations(where light precipitation
will be possible at times), project that the remainder of the
forecast district should experience dry conditions from Saturday
evening into Monday as dry, gusty and warm southwesterly upper
flow interacts with varying degrees of eastern Colorado surface
lee-side troughing. Fire weather highlights will most be likely
needed again Sunday and Monday due to the projected conditions.
Meteorological pattern then changes from later Monday(where even
some thunder is anticipated) into at least Thursday evening as
two upper systems interact with moist north-northeasterly surface
surges during this time-frame.
As of this discussion, it appears that the highest potential for
more widespread precipitation(including the potential for some
accumulating snow/blowing snow) over the forecast district during
the longer term should be realized from Monday evening into
Tuesday evening and then again on Thursday. As always, WFO Pueblo
will monitor closely.
Finally, warmest temperatures during the longer term are
expected from Saturday evening into Monday, while coolest
conditions should be realized from Tuesday into Thursday.
&&
.AVIATION...(For the 00Z TAFS through 00Z Saturday evening)
Issued at 348 PM MDT Fri Mar 23 2018
VFR conditions expected the next 24 hrs at all terminals, with any
patchy blowing dust at KPUB and KALS subsiding this evening.
Strong west winds, with gusts ranging from 35 to 45 kts, will
continue at all terminal forecast sites until early evening, with
much lighter winds overnight. On Saturday, winds will become gusty
once again, with S-SE winds gusting to 25 kts at KPUB and KCOS,
while S-SW gust to 20 kts at KALS. Over the mountains, -shsn
should end this evening, with clearing skies and VFR conditions
most locations by early Saturday morning.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
Red Flag Warning from noon to 7 PM MDT Saturday for COZ227>233.
&&
$$
UPDATE...LW