Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 10/28/19
Area Forecast Discussion
National Weather Service Duluth MN
628 PM CDT Sun Oct 27 2019
.SHORT TERM...(This evening through Monday night)
Issued at 332 PM CDT Sun Oct 27 2019
Cooler temperatures will be the trend in the short term following
the passage of a cold front earlier this morning, along with mostly
cloudy skies overnight.
Low level moisture will continue to be trapped under an inversion,
and with the thermal profile cooling this evening into tonight,
along with enough mixing, there may be just enough forcing to
squeeze out some sprinkles this afternoon turning into snow
flurries this evening into tonight. HRRR and RAP forecast soundings
show the top of the boundary layer hovering near the dendritic
growth zone for much of the night, which suggests that flurries will
be possible. These types of setups seem to favor horizontal roll
convection with low-level stratocumulus clouds, and this
organization is suggested in model reflectivity as well. The best
chance at seeing flurries or light snow showers will be in northeast
Minnesota as 500-mb cyclonic vorticity advection slowly pivots
across northern minnesota concurrent with a 250-mb jet max.
Temperatures will cool down into the 20s tonight. There will likely
be some partial clearing of the clouds later tonight as drier air
moves in, which may allow for some areas to reach the lower 20s,
while areas that remain under clouds will reach the mid 20s. Winds
will become light as the pressure gradient weakens overnight.
On Monday, a mix of clouds and sun is expected for most of the
region with temperatures only reaching the mid 30s under cool
westerly flow. Clouds will increase across northwest Wisconsin in
the afternoon into the overnight as a shortwave trough swings
through, followed by a clearing trend from west to east later in the
night. There could be a period of light snow in portions of
northwest Wisconsin, especially in Price and Iron counties, that may
bring a light dusting of snow.
.LONG TERM...(Tuesday through Sunday)
Issued at 332 PM CDT Sun Oct 27 2019
Fairly quiet conditions and below normal temperatures are
expected for the extended. Focus remains on a potential late week
system that may bring accumulating snowfall to parts of the
Northland.
An upper low will be over southwestern Hudson Bay at the start of
the extended with a trough extending southwest to another low over
the Intermountain West. To the east, surface low pressure is
expected to be located over lower Michigan with a vorticity maxima
traversing the Northland. This may lead to some light snow across
parts of northwest Wisconsin, but overall trends keep the bulk of
this system away from the Northland. As the upper trough to the west
moves through later Tuesday, a weak cold front will work across the
region and may bring a few light snow showers to areas along the
International Border Tuesday afternoon and night. High pressure will
then move in later Tuesday and remain in place into Thursday as a
second upper trough moves over the Northern Plains and into the
Northland Wednesday night. Skies should remain fairly clear,
however, allowing for good radiational cooling conditions both
Wednesday and Thursday mornings with readings in the teens and 20s.
Highs Wednesday will be right around freezing.
The trough will then move through on Thursday as an upper low
moves from the Central Plains to the Mid-Mississippi Valley. The
GFS and ECMWF remain in fairly good agreement bringing the surface
low from the lower Ohio Valley into southwestern Ontario Thursday
night. The 27.12 runs of both models have shifted the track a bit
to the east on this run, which keeps the effects of the system to
our south and east and brings no QPF to the CWA. The past few
runs of both the GFS and ECMWF have been waffling east and west
with the location of the low from run to run, so certainly not
ready to go with a dry forecast based on one model run when it
won`t take a huge shift in the track to bring effects to the area.
Some of the GFS ensemble members track the low much further to
the west across Wisconsin and into Upper Michigan, so we are far
from being out of the woods yet in terms of accumulating snowfall.
As such, we continue to run with NBM guidance until a more
consistent solution presents itself. A shortwave then drops out of
Canada heading into the weekend that will bring light
precipitation chances to the Northland. Highs will be in the 30s
for the end of the week and weekend with lows in the 20s.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 628 PM CDT Sun Oct 27 2019
Mainly VFR cigs at the start of the forecast. However, there are
pockets of MVFR cigs in the vicinity of the snow
showers/flurries/drizzle dotting the landscape. Will leave out
these lower cigs due to low confidence and carry VFR through the
forecast. Gusty winds will diminish by 02Z.
&&
.MARINE...
Issued at 332 PM CDT Sun Oct 27 2019
No hazardous conditions are expected across western Lake Superior
over the next 48 hours. Winds will gradually become westerly tonight
at 6 to 12 knots before becoming southwesterly on Monday at 10 to 15
knots. Winds will remain southwesterly on Tuesday at 10 to 15 knots.
Waves through the period will be under 2 feet.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 25 35 23 37 / 20 10 0 10
INL 24 34 21 34 / 0 0 0 0
BRD 24 35 23 36 / 0 0 0 10
HYR 25 36 23 40 / 0 10 20 10
ASX 27 38 25 42 / 10 10 10 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
LS...None.
&&
$$
SHORT TERM...JS
LONG TERM...BJH
AVIATION...GSF
MARINE...BJH
Area Forecast Discussion
National Weather Service Lincoln IL
907 PM CDT Sun Oct 27 2019
.SYNOPSIS...
Issued at 345 PM CDT Sun Oct 27 2019
After a sunny and pleasant fall day today across Illinois, a cold
front will push southeast into central IL during tonight, and
stay over the area on Monday. This will increase low clouds from
the northwest during tonight, with patchy fog possible overnight
into mid Monday morning east of the IL river. A cloudier day is
in store on Monday, with an increasing chance of light rain over
central and northwest IL late Monday afternoon and Monday night.
Light snow could mix in with the rain northwest of the IL river
overnight Monday night. Lows overnight will range from 38 to 45
degrees, coolest by Galesburg. Highs Monday will range from the
upper 40s and lower 50s northwest of the IL river, to the mid to
upper 60s in southeast IL.
&&
.UPDATE...
Issued at 907 PM CDT Sun Oct 27 2019
Monitoring two area of clouds this evening and working on timing
them into the CWA overnight. First area seen on satellite is over
central MO where clouds have finally begun to develop along the
approaching cold front. These clouds are expected to continue to
develop to the northeast across parts of central IL late tonight.
Second area of clouds is over southeast MO. HRRR has these clouds
advecting northward overnight and reaching into central IL toward
morning, but in southeast portions of the CWA. These two areas
will combine during the early morning hours, covering the whole
CWA around 6-7 am. So have made some adjustments to cloud cover
and lower high temps in the southeast for tomorrow. Will be
sending out an update shortly, but not sure it will change wording
of forecast all that much.
&&
.SHORT TERM...(This evening through Monday night)
ISSUED AT 345 PM CDT Sun Oct 27 2019
20Z/3 pm surface analysis shows 1017 mb high pressure over MS and
ridging into the TN and Ohio river valleys. This was providing a
sunny afternoon across the area with SSW winds 5-15 mph giving
seasonable temps of 60-65F. Aloft a 592 dm 500 mb high was over
the Southeast Atlantic coast while upper level trof extending from
central Canada back into the central Rockies and into CA. IL was
in a sw upper level flow so an active weather pattern lies ahead
this work week.
Latest CAMs bring a cold front from southeast IA and nw MO se
toward the IL river by early overnight and becoming quasi-
stationary in central IL later tonight into Monday. Post frontal
low stratocumulus clouds over central/western IA and nw MO will
likely move into central IL during overnight into Mon morning and
linger thru Mon night. Some patchy fog possible east of the IL
river overnight into mid Mon morning with low level moisture
trapped in a low level inversion and light winds. Could be some
isolated very light rain or sprinkles in west central and nw IL
late tonight. Lows overnight mostly 40-45F with upper 30s by
Galesburg. Models have trended wetter Mon afternoon over areas
from I-55 nw and have chance pops of light rain late Mon afternoon
along and west of the IL river, with likely to categorical pops
from I-55 west Mon evening. This due to increase forcing on cool
side of frontal boundary over central IL on Mon afternoon and into
Mon night. Highs Mon range from upper 40s by Galesburg to mid to
upper 60s in southeast IL. Lows Mon night range from mid 30s over
the IL river valley, with light snow possible with the light rain
nw of the IL river overnight Mon night. Milder lows in the low to
mid 40s in eastern IL with upper 40s by Lawrenceville.
.LONG TERM...(Tuesday through Sunday)
ISSUED AT 345 PM CDT Sun Oct 27 2019
Quiet weather returns briefly on Tuesday as IL will be in between
weather system, and forcing weakens behind the front by Tue
morning and weakening cold front exiting east of IL into eastern
parts of the Great Lakes and Ohio river valley by Tue afternoon. A
fair amount of clouds linger on Tue especially from the IL river
east with some sunshine possible west of the IL river Tue
afternoon. Highs Tue range from the mid 40s over the IL river
valley, to 55-60F in southeast IL.
Medium range models continue to dig an even stronger upper level
trof over the Rockies by mid week and eject some moisture ne into
central IL during Tue night and Wed. Again areas from the IL river
nw will see a chance of mixed pcpn overnight Tue night into early
Wed though little or no snow accumulations. Lows Tue night range
from near freezing at Galesburg to mid to upper 30s over much of
central IL and lower 40s in southeast IL. Highs Wed range from
lower 40s nw of the IL river to the low to mid 50s in southeast
IL.
The main storm system to eject ne on Thursday and bring the
highest chances of pcpn from Wed night and Thu evening. Between
1-2 inches of rain possible especially east of the IL river with
locally higher amounts possible in southeast IL. Much colder air
arriving during Thu night to change rain to snow showers and could
be some light snow accumulations then as ECMWF model had trended
colder during that time from. A widespread freeze likely to end
our growing season later Thu night with lows 27-32F. Dry and cool
weather expected Friday thru next Sunday with highs in the low to
mid 40s Friday and moderating a bit to upper 40s and lower 50s by
Sunday.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 637 PM CDT Sun Oct 27 2019
Skies are clear at all sites, but clouds will be moving in
tonight. Satellite loops show clouds slow progressing across
eastern IA behind a cold front. Thinking is that some VFR clouds
will arrive around midnight at PIA and then later at other sites.
However, MVFR cigs around 2-2.5kft will follow a few hours after
the clouds move in, followed by cigs below 2kft toward morning and
then lasting through rest of day. Winds will be southwest to start
and then become northerly to light and variable as the front moves
into the area and stalls over central IL. Northeast winds are
expected behind the front at PIA, with variable winds at the other
sites.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Auten
SYNOPSIS...07
SHORT TERM...07
LONG TERM...07
AVIATION...Auten
Area Forecast Discussion
National Weather Service Paducah KY
703 PM CDT Sun Oct 27 2019
.UPDATE...
Issued at 702 PM CDT Sun Oct 27 2019
Given the expansive overcast already invading the region from the
south early this evening, adjusted the forecast over the next 24
hours to reflect more sky cover than originally forecast. This had
the effect of reducing (but not eliminating) the anticipated fog
coverage overnight, in addition to raising temperatures tonight
and lowering temperatures on Monday. Used a blend of the CONSShort
and Experimental HRRR data, and blended into the NBM (National
Blend of Models). Further adjustments may be necessary. Remainder
of forecast is unchanged from prior.
&&
.SHORT TERM...(Tonight through Tuesday)
Issued at 200 PM CDT Sun Oct 27 2019
Potential exists for fog tonight, perhaps locally dense. MOS
indicates points west will be more conducive to fog
formation/density, but all sites are susceptible. Per collab with
neighbors, will highlight via SPS/HWO, vs headline.
It may take til mid-late Monday morning to scour remnant low
cloud/fog out, and burn thru the inversion. There is some model
disagreement on whether there will be any cloud above that...as a
frontal boundary makes its appearance on our northwest border.
Since most of the moisture advection/pcpn appears to lag the
front, will increase clouds west to east with time, but be a
little more gradual and less aggressive certainly with any pops
introduced in the short term forecast. Pending collab., may yield
late Monday night as we lean into Tuesday`s small pop mention in
our northwest.
Temps tonight in the 40s should recover into the 60s tmrw, pending
the aforementioned cloud clear out/slow beginning (west), while
they may push 70 south/east. More cloudiness/small pops appear
thereafter, so Monday night lows range from mid 40s-around
50. Tuesday temperatures should show a more substantial gradient
from 50s on our northwest/behind the front, to around 60 bridging
across the boundary/nearer the Ohio river, to approaching 70
again in the warm sector ahead of the boundary in our south/east.
.LONG TERM...(Wednesday through Sunday)
Issued at 200 PM CDT Sun Oct 27 2019
The extended period begins with a positively-tilted midlevel trough
located over the Four Corners region, with the PAH CWA under the
influence of strong southwesterly flow. At the surface, a stationary
front will be parked to our southeast, oriented southwest to
northeast across western Tennessee into central Kentucky. Ripples of
energy in this southwesterly flow will yield increasing chances for
showers Wednesday.
The midlevel trough will eject from the Four Corners region and move
through the Central Plain/Midwest through Friday. Surface low
pressure will develop over the ArkLaTex area and move northeastward
through the Lower Ohio Valley along the stationary boundary. Models
are in good agreement that this low will track to our south and
east. This will put us on the cooler side of the system, which will
preclude a severe weather threat for our area.
Main concerns with this system are precipitation amounts and timing
the end of the precipitation Thursday evening. Despite being on the
back side of the low, precipitable water values will once again be
two or more standard deviations above normal for late October, per
the latest GFS ensemble mean. Some models like the 12z GFS place our
region in a favorable area of upper-level divergence Thursday, which
could enhance rainfall rains as well. For precipitation totals,
leaned heavily on WPC guidance, with a blend of NBM. This yielded
storm total amounts of 1.5 to 2.5 inches. This will be over a fairly
long period, so flash flood concerns are low at this time. However,
given that we are suddenly soggy again, there may be flooding issues
in low-lying spots or in poorly-drained locations.
POPs decrease across the region late Thursday afternoon and evening,
but the rain may not be clear of a good portion of the area for
Trick-or-Treat time. Additionally, winds will pick up quite a bit in
the wake of the departing low, sustained at 15-20 mph with gusts of
25 to 30 with temperatures in the mid 40 to mid 50s, as colder air
works in.
Cold high pressure will dry us out for Friday into next weekend.
There will be a gradient in temperatures Wednesday-Thursday, with
highs ranging from the lower 50s in the northwest to the middle 60s
in the southeast. Behind the front, highs will only reach the upper
40s to lower 50s, with slowly moderating temperatures for the
weekend. There remains a possibility of widespread subfreezing
temperatures for next weekend.
&&
.AVIATION...
Issued at 554 PM CDT Sun Oct 27 2019
Late today, the leading edge of low clouds was from KPOF to KUCY
to KBNA. Trajectories around 1500 ft off in house model data
suggests a northward movement tonight, bringing MVFR cigs back
across the region, especially from 06z on at the Terminals. Winds
will be light as well. MVFR vsbys cannot be ruled out. A lot of
that will depend on the cloud cover. The lower cigs will likely
hang around Monday, with some improvement in base heights. Winds
should be light from the south.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...None.
MO...None.
IN...None.
KY...None.
&&
$$
UPDATE...RJP
AVIATION...08