Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 01/02/18
Area Forecast Discussion...UPDATED
National Weather Service Albuquerque NM
444 PM MST Mon Jan 1 2018
.AVIATION...
00Z TAF CYCLE
Northwest flow aloft with sct-bkn high clouds. Western extent of
upper trof passing thru ern CO and KS may allow for stronger nw-nly
winds aloft over ne NM aft 02/15Z. Otherwise, HRRR and RAP13 suggest
MVFR cigs may return to the Pecos Valley from KATS-KROW and nwd
possibly to KSXU aft 02/06Z and persisting until around 02/16Z.
&&
.PREV DISCUSSION...330 PM MST Mon Jan 1 2018...
.SYNOPSIS...
An upper level trough exiting the central Rockies on Tuesday will
steer a cold front into northern and western areas with a few degrees
of cooling, but the upper trough will actually help shift the
remnant Arctic airmass that has been over eastern New Mexico out of
the state. A general warming trend is then expected for the remainder
of the week as a ridge of high pressure crosses. Models depict a
disturbance crossing the Rocky Mountain states late this weekend
with cooler temperatures and wind, as well as a chance for
precipitation across portions of northern New Mexico.
&&
.DISCUSSION...
Cooler air will funnel into northwest areas tonight as an upper level
trough exits the northern and central Rockies onto the Great Plains.
The trough will send a back door front into the eastern plains with a
wind shift out of the north tonight as well, but the new airmass
will actually be warmer than the remnant Arctic airmass already in
place. Look for 6 to 12 degrees of warming across the plains Tuesday
afternoon compared to today`s readings, while most other places cool
a few degrees.
A ridge of high pressure aloft will gradually move inland over the
western US this week, before finally weakening and crossing NM at the
end of the week. The above normal warmth that has been entrenched
over western areas will spread eastward as the ridge approaches, with
highs across most of the plains finally rising above normal most
places starting Thursday.
The GFS and ECMWF Models differ on depth, but they agree somewhat
on the timing of a deeper upper level trough or low pressure system
that will cross this weekend. The system could bring cooler, windier
and wetter conditions on Sunday. The current track forecast by the
models suggests the northern and western mountains, and northwest
plateau, will be favored for wintry precipitation.
44
&&
.FIRE WEATHER...
Cold air will remain entrenched over eastern New Mexico on Tuesday
as an upper level trough clips the northeastern portion of the state
and reinforces the cold air over the plains. The upper level trough
will also bring a dry slot over NM, dropping dewpoints even lower
than they already area over the high elevations. Meanwhile, similar
to today, western areas will remain dry with above normal
temperatures.
An upper level ridge over the western CONUS will allow temperatures
to warm mid to late week, with all areas seeing above normal
temperatures by Friday. Main fire weather concern this week will be
poor ventilation, and areas that do see fair ventilation rates will
do so only for an hour or two most days. Additionally, the dry slot
will result in poor humidity recoveries over mountain tops Tuesday
night and Wednesday night, and daytime humidities will fall
near or below 15 percent for most areas Wednesday.
Models continue to indicate the ridge will break down next weekend,
but the ridge may build back in quickly thereafter. Even if it does
break down, models are not indicating much in the way of
precipitation any more.
34
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
See below for an aviation forecast discussion for the 00Z TAFs.
&&
.SHORT TERM...(This Evening through Tuesday Afternoon)
Issued at 345 PM CST Mon Jan 1 2018
The Arctic airmass that brought several days of brutally cold
temperatures will depart the region later tonight. With current
temps in the single digits and teens below, overnight lows should
easily drop several degrees tonight. The coldest readings should
occur along and east of the James River valley where they will be
influenced by the Arctic air the longest. However with westerly
mixing wind developing around 6Z, the eastern side of the Sisseton
hills may not fall into the teens below zero. Half km winds off the
NAM and ECAM support the potential of blowing snow tonight through
afternoon hours over the higher terrain areas of the Sisseton hills.
A clipper system will pass through the region between 15-21Z Tuesday
with gusty northwesterly and sct snow flurries possible. While the
ECAM, ARW, and NMM all show a narrow stripe of pops tracking
southward across the area, they do not generate QPF with the frontal
passage. Will maintain low chc pops along the boundary, but will
also mention sct flurries.
With decent mixing winds, the region should see it`s first above
zero day since December 29th.
.LONG TERM...(Tuesday Evening through Monday)
Issued at 345 PM CST Mon Jan 1 2018
The long term models show continued below normal temperatures across
the cwa through at least Friday as large scale upper level troughing
remains over eastern Canada and the eastern U.S. The ridge out
west/warmer air then builds east into the region and weakens as the
models then diverge a lot with the upper level flow and various
short waves in the flow affecting the central U.S. into Monday.
Overall, temperatures will be warmer for Saturday and Sunday. Upper
level heights then fall into Monday with cooler air pushing in.
Highs will be mainly in the single digits and teens for Wednesday
through Friday with 20s and lower 30s for Saturday and Sunday
cooling back to mainly the teens and lower 20s for Monday. Not much
of any significant systems for the long term. A weak system will
bring some chances of light snow to the eastern cwa on Thursday. The
model consensus then shows some more light snow chances again
Saturday night into Sunday and left these as is for now.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday Evening)
Issued at 536 PM CST Mon Jan 1 2018
Over the next 24 hours, conditions should be VFR at all four
terminals. That said, short-range guidance is depicting some sub-
vfr advection fog forming over the Missouri River valley tonight
and gradually spreading east toward the James River valley. There
is some low level moisture advection and warm air advection
developing right now across central and south central South
Dakota. It`s not entirely out of the realm of possibility that fog
could develop later this evening/overnight where the best low
level moisture advection and warm air advection sync up. For now,
the TAFs have been issued as VFR (no fog developing). But, if
satellite/obs indicate this fog scenario appears to be developing,
will be amending liberally.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...Wind Chill Advisory until 10 AM CST /9 AM MST/ Tuesday for
SDZ003>011-015>023-033>037-045-048-051.
MN...Wind Chill Advisory until 10 AM CST Tuesday for MNZ039-046.
&&
$$
UPDATE...Dorn
SHORT TERM...SD
LONG TERM...Mohr
AVIATION...Dorn
Area Forecast Discussion...UPDATED
National Weather Service Brownsville TX
518 PM CST Mon Jan 1 2018
.DISCUSSION...Last minute update to reduce pop coverage. Radar
echos have been decreasing in coverage over the last several hours
and and this meshes well with the latest HRRR and 12Z NAM.
Upper disturbance over Mexico has weaken considerably and is
likely moving over the SW Gulf and with drier surface air
continuing to advect into the area with lower dewpoints chance of
additional accumulating pops should fall below 20 percent for all
areas with exception to the immediate coast and over the Gulf
waters. Monitoring the latest observations and could expand the
freeze warning to the coast with temperatures in the mid to upper
30s and drier air continuing to filter into the region.
&&
.DISCUSSION...Updated for latest aviation discussion below.
&&
.AVIATION...Ceilings have been rising gradually this afternoon as
the cold air deepens across the region and rainfall also has been
diminishing in coverage as an upper level disturbance moves well
south of the region weakening the coastal trough. Flight
conditions to range from MVFR to VFR tonight and may lower down to
lower end MVFR by Tuesday morning, mainly at KBRO and KHRL, with
the approach of another disturbance moving south from the Central
Plains. Winds will continue to be the strongest near the coast
with some gusts near 20 knots this evening but will trend lower
overnight. Stronger north winds may develop late tomorrow
afternoon.
&&
.PRELIMINARY POINT TEMPS/POPS...
BAYVIEW/PORT ISABEL 35 43 31 47 / 20 30 10 10
BROWNSVILLE 33 43 31 50 / 20 30 10 10
HARLINGEN 32 42 30 50 / 20 20 10 10
MCALLEN 32 41 31 51 / 10 10 10 0
RIO GRANDE CITY 32 42 29 51 / 10 10 0 0
SOUTH PADRE ISLAND 39 45 36 48 / 20 30 10 10
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...Freeze Watch from late Tuesday night through Wednesday morning
for TXZ248>257.
Freeze Warning until 10 AM CST Tuesday for TXZ248>255.
Wind Chill Advisory until 10 AM CST Tuesday for TXZ248>257.
GM...Small Craft Advisory for winds until 6 PM CST this evening for
GMZ130-132-135.
Small Craft Advisory until 6 AM CST Tuesday for GMZ150-155-170-
175.
Gale Warning until 5 PM CST this afternoon for GMZ150-155-170-
175.
&&
$$
This product is also available on the web at:
HTTP://WEATHER.GOV/RGV
59/99
Area Forecast Discussion
National Weather Service Green Bay WI
527 PM CST Mon Jan 1 2018
Updated aviation portion for 00Z TAF issuance
.SHORT TERM...Tonight and Tuesday
Issued at 223 PM CST Mon Jan 1 2018
The latest RAP analysis and satellite/radar imagery show a large Arctic
high pressure centered across the central Great Plains early this
afternoon. Brisk west to northwest winds continue across the
region with wind chills only warming between 10 to 20 below zero
over eastern WI and 15 to 25 below zero over central and north-
central WI. Clouds and flurries have also retreated over far
northern WI as low level winds gradually back. With the next
system relatively far away over northern British Columbia, focus
of this forecast continues to revolve around temps and wind
chills.
Tonight...The Arctic high will gradually drop south into the mid-
Mississippi and Ohio Valleys, while the next Arctic cold front
slides southeast across central Canada. Between these two
features, the pressure gradient will tighten slightly, which
should maintain an 8-12 mph wind. Temps based on the best
performing guidance suggest readings will be warmer than last
night, which some cirrus pushing in from the north should only
help. But with the persistent wind, widespread wind chills of 25
to 35 below zero are anticipated again. Therefore, no changes to
wind chill headlines.
Tuesday...Winds will continue to back around to the southwest ahead
of an Arctic cold front, which will reach western Lake Superior
by late in the afternoon. Temps will be warmer, and should warm
enough to end the wind chill advisory by late morning or midday at
the latest. Though some scattered to broken cirrus will be around
to start the day, clouds will likely increase from northwest to
southeast during the mid to late afternoon hours. A small chance
that snow could reach far north-central WI 4-6pm. Highs ranging
from the upper single digits to low teens.
.LONG TERM...Tuesday Night Through Monday
Issued at 223 PM CST Mon Jan 1 2018
Cold arctic air will be in control of the western Great Lakes
through the early part of the weekend, keeping temperatures a good
10 to 20 degrees below normal for this time of year. Warmer
weather will then advect into the area late in the weekend into
early next week, sending temperatures to near normal levels and
possibly sending high temperatures at or above 20 degrees for the
first time since Christmas Eve.
A mid level PV anomaly coincident with a cold front will track
through Tuesday night, bringing a swath of snow through the
region. Although QPF amounts will be very light, on the order of a
few hundredths of an inch, fairly high snow to liquid ratios on
the order of 20 to 1 will squeeze a few tenths of an inch of snow
out of this system as it tracks through.
After this initial system tracks through the area, dry conditions
are expected for the rest of the week into the early part of next
weekend save for some Lake Effect Snow across the far north and
northern Door County at times. Snowfall from the LES bands should
generally be light during this period.
A large low pressure system will then track through the western
Great Lakes region during the second half of next weekend into
early next week. All models vary quite a bit in how they handle
the strength, timing and phasing of this system, making the
solution that far out difficult to interpret. From the available
data it appears the region could be in for a few inches of
measurable snow with temperatures warming closer to normal levels.
However the amount of snow will depend on if Gulf moisture can be
drawn this far north and if the northern and southern stream
systems can phase, and if they do phase do they phase over the
western Great Lakes or further downstream. Given the high degree
of variability will stick with the superblend solution out this
far and wait for a clearer solution to emerge from subsequent
forecast runs.
&&
.AVIATION...for 00Z TAF Issuance
Issued at 526 PM CST Mon Jan 1 2018
Good flying weather expected through Tuesday afternoon. Low level
wind shear possible late tonight and early Tuesday with west winds
of 5 to 10 knots at the surface and 30 knots at 1000 ft. Snow showers
and MVFR conditions expected Tuesday night as an upper level
disturbance moves by.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
Wind Chill Advisory until noon CST Tuesday for WIZ005-010>013-
018>022-030-031-035>040-045-048>050-073-074.
&&
$$
SHORT TERM.....MPC
LONG TERM......Kurimski
AVIATION.......RDM
Area Forecast Discussion...UPDATED
National Weather Service North Platte NE
531 PM CST Mon Jan 1 2018
.SHORT TERM...(This evening through Tuesday)
Issued at 330 PM CST Mon Jan 1 2018
The primary forecast challenge through Tuesday afternoon is...
surprise! Temperatures. Issued a new Wind Chill Advisory for the
entire CWA tonight through Tuesday mid-morning. This appears to be
more of a marginal event with a few spots around -25, but
nonetheless most of the CWA approaching or reaching -20.
As of 21z, pesky stratus has hung around all day across the western
2/3 of the CWA and has just begun breaking up along the edges in the
past hour or two. Lift has been strong enough along the mid-level
front and just enough moisture is present to squeeze out flurries
and some brief light snow showers. WAA has been fairly impressive
with H85 temps around -14C per RAP mesoanalysis. Highs ranged from
6F at ONL to 16F at IML (and 10F at LBF). WV imagery shows the next
shortwave near the Black Hills, progged to cross the forecast area
late tonight.
This evening/tonight... continued flurry chances for the heart of
the area through 00z with no accumulation expected. Model consensus
continues the dissipating trend of the stratus through the evening
with the most stubborn spots being generally from AIA to LBF/BBW. As
the shortwave comes through, the associated PV anomaly will help
clear the rest out. Subsidence is fairly strong aloft as the 1.5 sfc
reaches 550mb. Gentle isentropic upglide remains in the low levels,
but moisture is rather hard to come by. In short, expect efficient
boundary layer decoupling via clearing skies, light winds, and
remaining snowpack. Once again used the colder end of guidance for
min temps. Lows generally range from -5 to -10F.
.LONG TERM...(Tuesday night through Monday)
Issued at 330 PM CST Mon Jan 1 2018
The models, which are in good agreement, continue to show a return
to near average temperatures this week. A couple setbacks occur,
namely the backdoor cold front Wednesday and then a westward push to
the cold air behind this front on Friday. If things go as planned,
temperatures should rise into the 40s next Saturday. The GFS
ensemble, GFS operational, ECM and Canadian model are very close
building a 5-10C thermal ridge across Wrn and Ncntl Neb Saturday.
The warm-up this week will be compromised by the backdoor front
Wednesday with the h850mb temperatures dropping about 5 celsius.
Another minor setback occurs Friday as arctic high builds west and
south winds take hold which will limit mixing processes. The models
indicate west or northwest winds and deeper vertical mixing
Wednesday and Thursday.
The forecast is generally dry through Monday. Some model runs have,
at times, mustered sufficient forcing for widespread rain or snow
chances Sunday and Monday but the predictability of these weak
systems is low. So the forecast is mostly dry for now. The exception
is a snow chance Sunday night across northern Nebraska with the
arctic front. Note the slower GFS ensemble model would suggest a
more widespread light snow chance Monday so that model is worth
watching.
The model consensus today shows the potential for another arctic
front next Monday. The front appears to be preceded by a pacific
cold front Sunday. Thus, the temperature forecast peaks Saturday and
cools Sunday and Monday. The strength of the arctic push appears to
be fairly strong with h850 temperatures falling back to around -15C
and the high pressure system could be as strong as 1045-1050mb
across Montana according to the ECM and GFS.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 523 PM CST Mon Jan 1 2018
Stratus continues over western Nebraska to the west of a line from
KVTN to KODX. This area to slowly dissipate through the late
evening. Ceilings in MVFR categories. Southeast flow to decrease
through the evening with winds becoming light and variable
becoming west late Tuesday morning. VFR after 15z on Tuesday.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
Wind Chill Advisory from 9 PM CST /8 PM MST/ this evening to 10
AM CST /9 AM MST/ Tuesday for NEZ004>010-022>029-035>038-056>059-
069>071-094.
&&
$$
SHORT TERM...Snively
LONG TERM...CDC
AVIATION...Power