Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 11/11/19
Area Forecast Discussion
National Weather Service Grand Rapids MI
919 PM EST Sun Nov 10 2019
LATEST UPDATE...
Update
.SYNOPSIS...
Issued at 330 PM EST Sun Nov 10 2019
-Snow develops overnight near and south of a Grand Rapids to Alma
line, accumulates 2 to 5 inches Monday
-Slippery Monday morning commute likely as temperatures fall into
the 20s overnight
-Bursts of heavy lake effect snow at the lakeshore from late
Monday into Tuesday; localized amounts of up to one foot possible
around Ludington and also near South Haven
-Much below average temperatures this week; record coldest high
temperatures possible Tuesday
&&
.UPDATE...
Issued at 905 PM EST Sun Nov 10 2019
I did raise POPs for tonight. Based on radar and model trends it
looks like the precipitation will move in a little sooner. Some
enhancement off of Saginaw Bay may support Gratiot county for
inclusion in the headlines. The wind direction will make all the
difference as far as where the enhanced moisture will go. Right
now the flow is northerly in that area which would angle the
moisture just east of of Gratiot. New guidance is still coming in
so will await before making changes to the headlines at this
time.
&&
.DISCUSSION...(This evening through next Sunday)
Issued at 330 PM EST Sun Nov 10 2019
Winter Weather Advisories were issued a few hours ago to cover
both the synoptic burst of snow late tonight and Monday near and
south of a GRR to Alma line, as well as for the localized heavy
lake effect at the Lake Michigan shoreline from late Monday into
Tuesday.
Still some question regarding the nrn extent of the synoptic snow
tonight, but latest HRRR supports idea of snow reaching about as
far north as a GRR to Alma line before pivoting to a more nw to se
orientation and working east out of the area Monday afternoon.
Depending on trends, it`s possible that a few more counties such
as Montcalm and Gratiot will need added to the advisory later.
Accums from the synoptic event are expected to be 2-5 inches, the
majority of that falling 12Z-18Z Monday. Totals in the NNW flow
favored snow belts expected to be up to one foot - although those
high end amounts should be rather localized. The Ludington and
South Haven areas are favored.
The synoptic event which comes together late tonight and Monday
morning is related to lift in the right entrance region of a
150kt H2 jet streak. Strong mid level FGEN forcing along the
tight baroclinic zone should result in a banded look to the
precipitation and may result in non-uniform snow totals across the
advisory area - despite the model consensus for higher QPF
amounts the farther south and east you go.
Mild pattern before arrival of the low level cold air will lead
to some light rain or a mix of light rain and snow along I-94
initially this evening before all snow late tonight. The current
warm road temps in the 40s will result in wet roads initially
that will freeze up abruptly late tonight as the cold air surges
in and snow becomes more widespread.
Also- A very high DGZ above 10,000 ft and a deep isothermal layer
should lead to small/fine wet snow flakes that when combined with
the arriving Arctic air mass can lead to icy road conditions.
The Ludington area lake effect sets up after midnight in NNE flow
and has a lake Superior connection. Latest high res guidance
continues to suggest inch per hour rates under this band, although
some uncertainty on precisely when/where this band sets up. Band
in that area will re-align as winds shift more NNW on Monday and
probably transition from a dominant band into multiple bands.
For the Allegan/Van Buren area... only a brief lull between
departing synoptic snow Monday afternoon and arrival of the heavy
lake effect band(s). Inch per hour snows certainly possible over
a small area Monday night and Tuesday morning, before only a
gradual diminishing trend Tuesday afternoon as upper trough lifts
out.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 640 PM EST Sun Nov 10 2019
Lots of MVFR clouds around to start the period. As the colder air
moves in from the north there could be a period this evening of
VFR conditions...mainly for the northern TAF sites KMKG...KGRR and
KLAN. Snow will be spreading in from the west later this evening
into tonight. The onset could feature a brief period of rain for
KAZO to KBTL and KJXN.
A steady snow is expected for much of Monday morning into mid
afternoon. IFR will be common with LIFR possible. Late afternoon
hours will likely feature the steady snow moving out of the the
region...leaving behind lake effect snow bands. Those bands could
feature heavy snow with impactful aviation conditions.
&&
.MARINE...
Issued at 330 PM EST Sun Nov 10 2019
Small craft advisories in effect through Tuesday night for a
period of strong northerly flow which could flirt with gales late
Monday into early Tuesday. Freezing spray may develop considering
that an Arctic air mass is pouring in.
Have also issued a Lakeshore Flood Advisory for Allegan and Van
Buren Counties to handle to high waves which drive in toward the
Saugatuck and South Haven areas via the north-northwest winds
from Monday afternoon through Tuesday. Beach and bluff erosion is
expected. Lakeshore flooding is also expected in low lying areas
and along river mouths.
&&
.CLIMATE...
Issued at 350 PM EST Sun Nov 10 2019
The current forecast of high temperatures in the mid 20s on
Tuesday would break the daily record for coldest highs (or lowest
maximum temperature). The low temperature forecast for Tuesday and
Wednesday would come within a few degrees of breaking daily
records at some locations.
Record coldest high temperatures for November 12:
Grand Rapids... 27 (1920)
Muskegon....... 27 (1940)
Lansing........ 29 (1995)
Kalamazoo...... 28 (1920)
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...Winter Weather Advisory from 3 AM to 7 PM EST Monday for
MIZ057>059-065>067-072>074.
Winter Weather Advisory from 3 AM Monday to 1 PM EST Tuesday for
MIZ037-043-064-071.
Lakeshore Flood Advisory from 1 PM Monday to 5 PM EST Tuesday
for MIZ064-071.
LM...Small Craft Advisory until 11 PM EST Tuesday for LMZ844>849.
&&
$$
UPDATE...MJS
SYNOPSIS...Meade
DISCUSSION...Meade
AVIATION...MJS
CLIMATE...CAS
MARINE...Meade
Area Forecast Discussion
National Weather Service Indianapolis IN
1000 PM EST Sun Nov 10 2019
.UPDATE...
The NEAR TERM and AVIATION Sections have been updated below.
&&
.SYNOPSIS...
Issued at 253 PM EST Sun Nov 10 2019
A frontal system is expected to pass through the local area tonight
into Monday. In the wake of this front, high pressure in general
will build into the area by the middle and later parts of the
week.
&&
.NEAR TERM /Rest of Tonight/...
Issued at 1000 PM EST Sun Nov 10 2019
The surface cold front has sunk south of Indianapolis and Terre
Haute by around 9 pm. HRRR shows development along or just north of
the front during the overnight, but it has been overdeveloping
precipitation all night so generally disregarding this solution.
Other models (and observations) show ongoing forecast on track and
no major adjustments anticipated. Previous discussion follows...
Models suggesting little in the way of organized lift tonight, and
deeper moisture is restricted to the lower levels. As a result, not
too impressed with precipitation chances tonight. Will restrict the
chance PoPs more towards the early morning hours of Monday, as a
result.
Low level thicknesses off the short term models suggest the GFS MOS
lows tonight are probably too cool. Will nudge up the guidance lows
a category.
&&
.SHORT TERM /Monday through Wednesday/...
Issued at 253 PM EST Sun Nov 10 2019
Model data suggest a strengthening 850mb front will pass across the
area during the day Monday. Best forcing looks to develop towards
the midday hours and on into the afternoon. Will continue with
chance PoPs during the morning, and go with high PoPs towards midday
through the afternoon.
Strongest low level cold advection on Monday looks to occur from the
late morning through the afternoon, roughly timed with the passage
of the 850mb front. This should allow for a change over to snow from
north to south, starting in the north by late morning or midday.
Forcing still looks pretty good for a period during the afternoon
near and behind the expected change over, so it may snow at a good
clip for awhile during Monday afternoon. Still some questions
revolving around how fast the change over occurs, but the potential
exists for a few inches of accumulation over the northern zones if a
quicker change over occurs. Advisories may be needed in these areas
for Monday afternoon if things trend towards a quicker
change over.
Will keep some PoPs going into Monday night for snow showers to
cover any lingering activity, and the potential for some activity
associated with a moisture plume off of Lake Michigan.
Outside of a lingering flurry chance over the northeast Tuesday
morning, Will keep the rest of the short term dry at this time, as
surface high pressure slides through the local area. Another
potential disturbance may drop into the western Great Lakes by
Wednesday afternoon, but operational and ensemble data suggest any
precipitation threat from this disturbance will remain off to the
northwest of the local area on Wednesday.
Given the stronger cold advection may hold off until later in the
day Monday, will nudge up the GFS MOS highs on Monday a few degrees.
The highs should occur during the morning hours, with temperatures
falling later in the day. Progged low level thicknesses suggest the
guidance temperatures later in the period look OK for now.
&&
.LONG TERM (Wednesday Night Through Sunday)...
Issued at 240 PM EST Sun Nov 10 2019
Models are close enough that the National Blend of Models
initialization was accepted for most items.
Although temperatures will gradually moderate through next weekend,
readings will remain below normal.
Another upper trough will move through Wednesday night into
Thursday, but the better forcing will remain north of the area.
Moisture is still not great, but there now looks to be enough
forcing and moisture to put in low PoPs in the extreme north
Wednesday night.
High pressure will then keep the area dry into next weekend. Models
differ on the speed of the next system, with some bringing in
precipitation next Sunday. With the uncertainty that far out,
decided to just keep the initialization`s dry forecast for then.
&&
.AVIATION /Discussion for 110300z TAF issuance/...
Issued at 1000 PM EST Sun Nov 10 2019
Updated current conditions only. Previous discussion follows...
VFR to start at the sites, with ceilings dropping to MVFR around 5
to 7z. Could see some light rain develop in a few spots after
around 9z. Initially expect rain, but then a changeover to a
brief mix and then snow is likely around 12-15z at KLAF, 17-19z at
KHUF and KIND, and 20-22z at KBMG. IFR ceilings and visibilities
are expected at times during the precipitation. Winds will shift
from light westerly and possible even variable overnight to
northerly and winds during the afternoon and early evening will
increase to around 10 to 15 kts with gusts to around 25 kts.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory from 11 AM to 8 PM EST Monday for INZ021-
030-031-038-040>042.
&&
$$
SYNOPSIS...JAS
NEAR TERM...JAS/CP
SHORT TERM...JAS
LONG TERM...50
AVIATION...CP
Area Forecast Discussion
National Weather Service North Platte NE
651 PM CST Sun Nov 10 2019
...UPDATE...
.UPDATE...Issued at 647 PM CST Sun Nov 10 2019
Have expanded the winter weather advisory southward to include far
southwest Nebraska. This is primarily for a period of freezing
drizzle that is occurring behind the southward moving cold front.
Models also agree that a bit heavier snowfall nearing 3 or 4
inches could occur in a band across portions of the central and
southern Panhandle into west central and southwest Nebraska. Have
tweaked snowfall totals up a bit in these areas. Also increased
wind speeds some as gusts exceeding 30 mph are likely this evening
due to strong cold air advection and pressure rises behind the
front.
&&
.SHORT TERM...(This evening through Monday night)
Issued at 300 PM CST Sun Nov 10 2019
Arctic air will continue to build into western and north central
Nebraska. Temperatures by Monday morning will be in the teens and
single digits with wind chill readings of 10 below zero across
northern Nebraska. Snow and near record cold following on the
heels of record/near record warmth Saturday will likely cause
hazardous travel tonight across much of western and ncntl
Nebraska.
The morning model runs of the HRRR, RAP and NAM are showing better
lift with the snow event tonight. The NAM is even phasing an upper
level disturbance across WY with the arctic air tonight. This is
producing a longer duration of seeder-feeder processes for light
snow tonight. The latest short term forecast blend suggests a more
expansive area of 2 inches of snow with totals near 3 inches across
wrn Cherry and Sheridan counties. The HRRR seems to have the best
handle on the freezing drizzle operating for a couple of hours
before the deeper moisture gets established. Snow is the primary
precipitation type in terms of impact on travel. The HRRR is showing
banded snow structures with visibility falling to less than 1 mile
in moderate to perhaps briefly heavy snow tonight.
The temperature forecast leans on the cooler hourly MET and MAV
guidance plus bias correction. High temperatures in the upper teens
to mid 20s are expected Monday. This is similar to the previous
forecast. If the snowfall forecast verifies, highs might be a few
degrees cooler but sun is expected in the afternoon. The predicted
lows in the teens and single digits tonight and Monday night are
similar to the previous forecast. Monday night`s lows will likely
occur around or before midnight with south winds developing
overnight.
.LONG TERM...(Tuesday through Sunday)
Issued at 300 PM CST Sun Nov 10 2019
nothing dramatic winter-wise occurs in the extended forecast.
A weak cold front Wednesday may produce a period of light rain and
snow across ncntl Nebraska. The temperature rebound to the upper 40s
across wrn Nebraska Tuesday might be overdone given the expected
light snow cover. Temperatures should still rise into the 40s.
Mild weather will continue through Saturday with no big cold
fronts or deep storm systems affecting wrn and ncntl Nebraska.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 631 PM CST Sun Nov 10 2019
A strong cold front is moving southward across the region this
evening. Low ceilings (IFR) are rapidly spreading south along with
areas of light freezing drizzle and snow. The freezing drizzle
will switch to all so after midnight (06Z). Gusty north winds to
near 30 kt are expected through the evening, with winds decreasing
somewhat but still gusty after midnight. Conditions rapidly
improve Monday morning as dry cold air moves into the region from
the north.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory until 7 AM CST /6 AM MST/ Monday for
NEZ004-005-008>010-022>029-035>038-056>059-069>071-094.
&&
$$
UPDATE...Taylor
SHORT TERM...CDC
LONG TERM...CDC
AVIATION...Taylor
Area Forecast Discussion
National Weather Service Marquette MI
658 PM EST Sun Nov 10 2019
.SHORT TERM...(This evening through Monday)
Issued at 353 PM EST SUN NOV 10 2019
...Persistent lake-effect snow expected through Tuesday...
Current GOES imagery and radar show a developing Lake Nipigon band
racing across Lake Superior as ongoing lake-effect -shsn continues
across the NW wind belts. The main challenge for this period is the
amount of saturation in the model soundings, and then the
corresponding snow ratios. The going forecast shows increasing
ratios as the cold air moves in with the highest elevations seeing
close to 30 to 1 with elsewhere showing 22-24 to 1. As CAA continues
across Upper Michigan, temps aloft are progged to fall
quickly...which will limit saturation through the DGZ. Despite
increasing inversion heights under continued CAA, depth of the DGZ
was concerning. Model soundings suggest the depth of the DGZ to be
on the order of 2.5 to 3 kft. Given that the airmass moving in to
the region is comparable to that of mid-January, ended up reducing
SLRs approximately 10% from the going forecast. Reducing SLRs didn`t`
affect snowfall totals too much with some changes to QPF, but
overall expecting snow intensity to pick up tonight, leading to 4 to
8 inches across the NW wind lake-effect snow belts in western Upper
Michigan through Monday evening. Across the eastern portions in the
NW wind belts, expect between 6 to 12 inches through Monday evening,
with isolated amounts up to 18 inches possible if the dominant Lake
Nipigon band trains over the same location. Lake-effect snow showers
will continue through Monday evening into Tuesday, more on that in
the long-term AFD.
Outside of the snowfall amounts during this period, expect
temperatures to continue to fall tonight with little rebound
tomorrow as continued CAA moves into Upper Michigan. For tonight
single digit lows across the west with some low teens across the
east. It does not appear likely that we will break any record lows,
but tomorrows high temperatures may break some records. Forecast
highs are in the teens across the west, with up to low 20s across
the east and along Lake Michigan. At the office, the record cold
high for tomorrow is 21, with a forecasted high temperature of 18
degrees. It seems likely that we will break this record; however, if
a dominant lake-effect band moves overhead, we might manage to warm
up a little more.
.LONG TERM...(Monday night through Sunday)
Issued at 344 PM EST SUN NOV 10 2019
Heavy lake effect snow will be ongoing in the NW to NNW wind belts
to start the long term Monday night as an unseasonably cold airmass
continues to funnel in from the northwest. An upper trough axis will
be moving across the region, and at the sfc low pressure will deepen
across the northeast while broad high pressure dips south through
the Plains. Prolonged moderate flow of cold air (850 mb temps as low
as -23 west and -20 east) across the warm lake waters of Lakes
Nipigon and Superior, combined with very deep inversion heights near
8-10 kft and plenty of lift will lead to big snowfall totals,
especially near IWD and east of Marquette. One limiting factor will
be that the airmass will be cold enough to prevent a very deep
environmental DGZ, but SLRs should still be in the 20-23:1 range for
the most part.
There remains some discrepancy in where the heaviest bands will set
up Monday night. Early in the evening, it will more likely be over E
Alger into N Schoolcraft, but confidence is increasing that winds
may take on more of a northerly component overnight, bringing
heavier banding westward and likely impacting far eastern MQT
County from Harvey to Skandia and points eastward. CMC and hi-res
WRF-NMM both point to this solution, with some hint in the ARW as
well. 18Z HRRR that goes out to 06Z Tuesday is not quite biting
on that yet, though.
There will also be ongoing snow showers over the western UP,
heaviest in western Gogebic County and at the tip of the Keweenaw,
but the heaviest banding is expected over the east where greater
fetch and additional convergence will lead to similar conditions
as were seen earlier this week. Snowfall totals 8pm Monday to 8am
Tuesday (in addition to what will have already fallen tonight
through 8pm Monday) will be 2-5" west with 4-8" in Gogebic
County. East, higher totals of 6-10" and locally more are
possible. Some blowing and drifting will be possible along the
lakeshore.
Regardless where the heavy bands set up overnight, they will push
back towards the east and gradually diminish through the day
Tuesday. As drier air moves in, inversion heights will quickly lower
and cut off most of the snow over the west completely by midday
Tuesday with snow ending east by the evening after additional
daytime accumulations of 3-6". This will be a short-lived break,
however. As high pressure moves eastward into the Ohio Valley, winds
will shift to southwesterly and almost due southerly over Lake
Michigan. With the cold airmass in place, a Lake Michigan LES band
is likely to set up over Schoolcraft/Luce counties and Advy level
snow is very possible with this event as well.
Following that, temperatures look to finally begin to modulate back
towards slightly below normal instead of downright cold. Monday
night through Wednesday, expecting overnight lows in the single
digits and wind chills approaching -10 in the early mornings.
Concerned about motorists becoming stranded in the heavy snows
Monday night/Tuesday that would have to deal with the dangerous
cold. For that reason, travel is not recommended except for folks in
the south-central away from the potential for heavy snow. But later
this week into the weekend, daytime highs will return to the upper
20s and 30s. Some light lake effect will be possible Thursday
night/Friday morning, and then some light to moderate synoptically
forced snow is possible Sunday as a shortwave approaches from the
west.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 655 PM EST SUN NOV 10 2019
Continued NW wind driven lake-effect -SHSN will impact all TAF sites
throughout the period. Highest confidence for CMX and IWD with SAW
remaining right along the border of conditions. Brief IFR vsbys can
be expected at times during -SHSN with prevailing MVFR for CMX/IWD
with VFR expected at SAW. For cigs, generally MVFR conditions at
all TAF sites with a chance for brief IFR at IWD and CMX, and a
chance at SAW to be VFR depending on where exactly lake-effect
bands set up. Otherwise, gusty conditions at times for all of
Upper Michigan with gusts on Monday between 20 and 25 knots.
&&
.MARINE...(For the 4 PM Lake Superior forecast issuance)
Issued at 344 PM EST SUN NOV 10 2019
NW wind gusts approaching 30 knots will gradually diminish through
this evening to 20-25 knots overnight. Monday, some gusts to 30
knots will return, perhaps with a few gale force gusts to 35 knots
over south-central portions of the lake. Winds will remain NW at 20-
30 knots Monday night, dropping to 10-20 knots Tuesday and then
shifting to the SSW Tuesday night. Speeds will be picking back up to
near 25 knots on Wednesday, and to 30 knots over the east half. This
up and down trend with the winds will continue throughout much of
the remainder of the week, with 25 to 30 knot sustained winds
looking to return Thursday into early Friday. This event will
feature winds out of the WSW to NW and will hold the next potential
for gale headlines with the details to be ironed out through the
week.
With unseasonably cold temperatures moving in tonight, expect some
freezing spray with those gusty winds into early Tuesday.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
Winter Storm Warning until 10 AM EST /9 AM CST/ Tuesday for
MIZ006-007-009-085.
Winter Weather Advisory until 10 AM EST Tuesday for MIZ002-005-
014.
Lake Superior...
None.
Lake Michigan...
None.
&&
$$
SHORT TERM...JAW
LONG TERM...KCW
AVIATION...Voss
MARINE...KCW