Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 10/11/18
Area Forecast Discussion
National Weather Service Billings MT
952 PM MDT Wed Oct 10 2018
No updated. Light snow will approach Billings from the west but
HRRR guidance shows just some flurry activity expected. borsum
.SHORT TERM...valid for Thu and Fri...
Area remains under cyclonic flow aloft tonight with another piece
of energy rotating into the area from the west overnight. This
will keep occasional flurries and snow showers in the forecast for
mainly locations west of a Forsyth to Broadus line through
tomorrow morning. Could see some light snow accumulation in the
north/east facing foothills and mountains tonight, otherwise just
a dusting in spots with no travel impacts anticipated at this
time. Temperatures tonight will not move much over central and
western zones as cloud cover insulates this area, but over
northeast zones from Miles City to Baker there will be some
clearing which will allow temperatures to drop into the teens to
around 20 degrees overnight. Will need to bundle up the kids for
the bus stop Thursday morning.
Trof exits south and east Thursday afternoon with clouds clearing
from northwest to southeast. Temperatures will remain cold
tomorrow with highs in the 30s to lower 40s. Lee side trofing
will allow westerly winds to increase helping to warm temperatures
into 50s to around 60 degrees on Friday with sunny skies to start
the day. Clouds will increase ahead of another shot of cooler air
Friday night that will push temperatures back into the 30s and
lower 40s with a chance of snow Saturday. Chambers
.LONG TERM...valid for Sat...Sun...Mon...Tue...Wed...
Northerly flow with cloudy skies and snow showers will make
Saturday a tough day for outdoor activities. Temperatures will
hold in the 30s to lower 40s but wind chills will make it feel
much colder. A 1035mb surface high and clearing skies will allow
temperatures to fall into the teens and lower 20s in most
locations, with single digits in the mountains. Sunday will
continue to be cold with highs again in the 30s to lower 40s.
A change to a warmer and drier regime begins on Monday as west
coast ridge bumps core of the coldest air path further into the
Dakotas, and increases downslope component of the low level flow
over our area. Will see one more chance for showers from late
Monday into Tuesday morning as the tail end of another Canadian
front drops into the area. A stretch of mainly dry conditions
follows through late next week. Temperatures will nudge into the
50s Monday and Tuesday, with some 60s possible Wednesday and
MVFR to IFR conditions will continue over western and central
areas through tonight as areas of light snow and low cigs impact
the region. Gradually improving conditions can be expected over
eastern areas, including KMLS and KBHK. Mountains will continue to
be obscured. STP
.PRELIMINARY POINT TEMP/POPS...
Thu Fri Sat Sun Mon Tue Wed
BIL 026/042 028/058 033/040 023/044 029/052 032/054 035/059
33/J 00/U 44/J 21/U 01/B 31/B 11/U
LVM 024/044 026/055 030/039 020/042 025/051 028/054 031/059
43/J 00/U 55/W 20/U 01/U 21/B 11/U
HDN 026/042 026/058 031/040 022/042 026/052 031/053 032/060
13/J 00/U 43/W 21/U 01/B 31/B 11/U
MLS 024/041 026/056 032/038 021/040 026/051 031/049 032/059
11/E 00/B 22/J 11/U 02/W 31/B 10/U
4BQ 023/041 026/057 032/041 021/039 024/051 031/050 032/059
11/E 10/U 23/J 11/B 02/W 31/B 11/U
BHK 019/040 024/053 029/036 018/037 021/048 028/046 028/056
00/B 00/B 12/J 10/U 02/W 31/B 00/U
SHR 022/041 023/055 029/038 018/039 020/051 028/051 028/059
33/W 20/U 46/W 31/B 11/U 31/B 11/U
Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
641 PM CDT Wed Oct 10 2018
206 PM CDT
Numerous showers, moderate to heavy at times, are expected
through the afternoon. There could be a few thunderstorms, but
with only 500 J/kg per the latest RAP analysis, storms should be
few and far between. Shear still looks favorable, but all other
parameters are not favorable for severe storms, so I`m not
expecting any severe storms. Showers shift east ahead of the
approaching cold front ending from west to east early this
The front is over the Mississippi River and will shift overhead
late this afternoon into tonight. Winds will become west and gust
to 30 MPH immediately behind the front. Gusts increase to around
35 MPH this evening as we mix higher into the column. If mixing is
greater than currently expected, gusts could be higher.
Most areas have reached their high temp for the day and
temperatures will continue to fall into the upper 30s to low 40s
overnight. Windchills will be in the low 30s Thursday morning.
233 PM CDT
Thursday through Wednesday...
No significant weather impacts appear to be in store through mid
next work week. However, the big story will be the sudden flip
from summer-like to late fall-like weather. On Thursday, strong
cold air advection will support fairly deep mixing, thus brisk
west-northwest winds will gust to 25-35 mph. As mentioned in
short-term AFD, after 2 days with highs in 80s this week and 70s
today, wind chill values for the Thursday morning commute will be
in the lower to mid 30s, quite a change. Broken to closed cell
stratocumulus will gradually erode during the afternoon, with
highs only in the upper 40s to lower 50s for most, except possibly
mid 50s far south.
Mostly clear to partly cloudy skies and diminishing winds
Thursday night into early Friday should set the stage for lows in
the lower to mid 30s outside of Chicago. With winds unlikely to
drop to calm, a bit hard to say how much true frost development is
in store, though do have areas to widespread mention outside of
downtown Chicago. Would anticipate a decent chance for
frost/freeze headlines being needed, unless clouds increase
quicker in advance of the next wave approaching from the west.
Models vary on precip coverage and northward extent on Friday
afternoon, with current focus of chance PoPs currently more so
south of I-80, though with latest ECMWF favoring northward, this
forecast is subject to change. Highs Friday will only be in the
mid 40s to lower 50s, again well below the normal lower to mid
Surface high will quickly move in Friday night into Saturday and
center just south of us. This will likely be close enough for
sufficiently light winds for good radiational cooling and lows
30-35 outside of Chicago (possibly a few upper 20s in typical cool
spots per MET MOS guidance), assuming skies do clear as expected.
Depending on how cold it gets, this has the potential to be a
killing freeze for sensitive outdoor plants. After highs mainly in
the 50s Saturday and a bit milder readings Saturday night, another
cold front will move across the area Saturday night into Sunday
with a small chance for light rain. Looking ahead to later Sunday
into Monday, ECMWF had been indicating a strong upper jet
interacting with lower-level baroclinic zone to blossom an area of
light precip much farther north than other guidance. Latest run
did back off a bit on this while other guidance keeps the rain
south. In deference to ECMWF and given the uncertainty, did
maintain some PoPs.
Monday will have highs in the 40s likely for all or most locations
north of I-80 and another near freezing night outside Chicago
Monday night. The long-wave trough responsible for the cool
weather and possible reinforcing cold shot by around mid week may
lose its grip later next week beyond day 7.
For the 00Z TAFs...
641 pm...Forecast concerns include strong/gusty westerly winds
through Thursday evening and mvfr cigs through Thursday afternoon.
A cold front will move east of the terminals early this evening
with westerly winds for the rest of the period. Speeds are likely
to be in the 15-20kt range with gusts 25-30kts through sunset
Thursday evening when speeds will diminish and winds will turn a
bit more to the northwest. Mvfr cigs will spread back across the
area in the next hour or so and continue into Thursday afternoon
when cigs should lift but how much the clouds scatter out is a bit
uncertain but its possible the low clouds may scatter out. cms
206 PM CDT
A strong cold front will pass early this evening. Following the
frontal passage this evening, wind gusts may briefly gust to near
35 kt gales, especially along the IL near shores, before gradually
settling down to near 30 kt overnight and into Thursday.
I think there will be a few gale force gusts, so I opted to go
with a Gale Warning. However, winds should diminish below gales by
mid Thursday morning.
LM...Gale Warning...Winthrop Harbor to Northerly Is. until 10 AM Thursday.
Small Craft Advisory...Northerly Is. to Michigan City IN until 4 AM
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
Area Forecast Discussion
National Weather Service Sacramento CA
300 PM PDT Wed Oct 10 2018
Weak weather systems will bring light showers to the Sierra today
and Thursday. Locally breezy north to east wind today into
Friday. Temperatures remain near normal through Friday, then
slightly above normal this weekend.
Interior NorCal sandwiched between high amplitude ridging in EPAC
and deep longwave troughing over U.S. Water Vapor imagery showing
short wave trough dropping through NorCal under northerly flow
aloft. Visible revealing clouds associated with this wave over
the Sierra Nevada and 88-D indicating scattered light showers.
Latest HRRR suggest showers will continue over higher elevations
of the Sierra Nevada til around 07z. Light snow is possible over
Sonora, Ebbetts, and Carson passes. Locally breezy northerly wind
possible in Shasta county and Northern Sacramento Valley into
Additional short wave trough drops south and digs offshore
Thursday as upper ridging builds into the PacNW. Models keep a
threat of showers over the Sierra Nevada with light snow again
possible over the passes, above 8000 feet. NEly flow aloft
develops over NorCal with locally gusty north to east wind.
Strongest wind, gusts to around 30 mph, expected northern and
western portions of the Sacramento Valley, east slopes of Coastal
Range, eastern foothills and favorably oriented canyons of Western
Plumas mountains and Sierra Nevada. Drying downslope flow will
Offshore trough develops into upper low Friday and digs Saturday as
upper ridging continues to build over NorCal. Locally breezy wind
persists into Friday morning then gradient weakens some. Near
normal temperatures today into Friday, then about 3 to 5 degrees
above normal forecast this weekend.
.EXTENDED DISCUSSION (Sunday THROUGH Wednesday)
High amplitude upper ridging in EPAC extends inland along the
West Coast Sunday into middle of next week with dry conditions.
Highs will be slightly above normal with 80s in the Central
Valley, and generally 60s to 70s for the mountains and foothills.
Locally gusty north to east wind possible at times with lowering
VFR conds ovr Intr NorCal nxt 24 hrs. Isold MVFR poss ovr Siernev
in -shra with -shsn poss abv 080 MSL til 07z. Lcl Nly sfc wnd
gsts to 20 kts in ptns of nrn and wrn Sac Vly til 02z and agn aft