Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 12/21/21
Area Forecast Discussion
National Weather Service Lincoln IL
719 PM CST Mon Dec 20 2021
.SYNOPSIS...
Issued at 244 PM CST Mon Dec 20 2021
Quiet weather will prevail across the region this week. Seasonable
temperatures in the upper 30s and lower 40s are anticipated for
the next couple of days...followed by a big warming trend that
will see readings climbing into the upper 50s and lower 60s by
Christmas Eve.
&&
.UPDATE...
Issued at 719 PM CST Mon Dec 20 2021
Weak cold front was roughly centered along I-55 this hour, and is
progged to reach east central Illinois after midnight. No real
impacts at the moment. Earlier concern was for areas of dense fog
where this front settled up overnight. However, latest high-res
models have significantly backed off this potential, with only the
RAP showing a narrow corridor from about Danville southwest to
Pana with a significant potential for dense fog. Forecast
soundings are dry much of the lower atmosphere but show an
inversion around 500 feet late tonight, which could trap some of
the surface based moisture and cause another frosty morning with
patchy slick spots on bridges and overpasses. Will not remove the
dense fog mention at this point, but continue to monitor as the
remainder of the evening high-res model suite arrives over the
next couple hours.
&&
.SHORT TERM...(This evening through Tuesday)
ISSUED AT 244 PM CST Mon Dec 20 2021
A weak cold front currently approaching the Illinois River will
settle southeastward into central Illinois tonight. Winds will
become light/variable near the frontal boundary, which will lead
to the formation of fog. CAM solutions have varied from run-to-run,
but are honing in on lowered visbys centered along a Danville to
Taylorville line after midnight into Tuesday morning. RAP/HRRR
have consistently featured dense fog east of the I-55 corridor,
while the GFS LAMP has just recently lowered its visbys across
this area. Current dewpoints east of I-55 are slightly higher than
previously forecast in the lower 30s. This is the same area that
saw patchy 5-6 mile visbys early this morning. Given expected
placement of front later tonight and better agreement among the
high-res models, have added fog to the forecast everywhere
along/south of a Rantoul...to Lincoln...to Jacksonville line.
While confidence for widespread dense fog and an advisory are not
quite there yet, have opted to mention areas of dense fog. With
temperatures well below freezing in the middle 20s, scattered
slick spots may develop on area roadways toward dawn...especially
on bridges and overpasses. Will issue an SPS and mention this
hazard in the afternoon HWO. After the morning fog dissipates, a
return to mostly sunny and dry weather is anticipated by Tuesday
afternoon with highs topping out in the lower to middle 40s.
&&
.LONG TERM...(Tuesday night through Monday)
ISSUED AT 244 PM CST Mon Dec 20 2021
Zonal flow across the CONUS will allow a series of fast-moving
systems to skirt along the US/Canadian border this week. Given
this particular storm track, any precip associated with the waves
will remain well north of Illinois. The next wave and its associated
cold front will quickly arrive by Tuesday evening. Given the far
northerly track and the overall lack of deep-layer moisture, am
expecting little sensible weather other than a shift in the wind.
End result will be dry weather with seasonable temperatures in the
30s and 40s Tuesday and Wednesday.
After that, a significant short-wave trough is progged to dig into
the western CONUS...resulting in downstream ridging over the
Midwest/Great Lakes. Thanks to rising upper heights and a return
to southerly flow, temperatures will climb well above normal for
this time of year by the end of the week. In fact, highs will
likely soar into the upper 50s and lower 60s by Christmas Eve.
While a slight cooling trend is expected by next weekend,
continued zonal flow will ensure any cold/winter air masses
remain locked well to the north across Canada through the
remainder of the extended and beyond.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 515 PM CST Mon Dec 20 2021
Main forecast concern will be potential for low clouds and fog
near KDEC/KCMI late in the night, near a weak surface boundary.
High-res models have been a little variable recently with the
expected coverage. However, will keep a mention of IFR
visibilities at these sites as introduced in the previous TAF set.
Further north behind the boundary, VFR conditions should prevail.
While winds gradually turn northerly this evening, they should
become gusty from the southwest by late Tuesday morning.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Geelhart
SYNOPSIS...Barnes
SHORT TERM...Barnes
LONG TERM...Barnes
AVIATION...Geelhart
Area Forecast Discussion
National Weather Service Lake Charles LA
952 PM CST Mon Dec 20 2021
.UPDATE...
Upper level low over northwest Louisiana and southwest Arkansas
continues to push the light rain off to the east and northeast.
Skies to remain cloudy through the overnight in southeast Texas
and southern Louisiana as the low pushes eastward. Dew points are
currently in the 30s across northern Louisiana with low 40s in
southeast Texas and southern Louisiana. But the lower dew points
will push into the region overnight allowing temperatures into the
30 towards sunrise with north winds.
Tomorrow looks to be warmer with highs into the 50s as a general
warmup becomes established. Current zones are fine at this time.
.PREV DISCUSSION... /issued 553 PM CST Mon Dec 20 2021/
DISCUSSION...
For the 12/21/2021 0000 UTC TAF package.
AVIATION...
Deeper cloud cover continues exiting to the east along with the
light to modt RA that affected parts of the area earlier today. A
swath of SC continues to blanket the region, but has begun to
erode acrs SE TX. How quickly these clouds will dissipate acrs the
area is somewhat in question, with MOS guidance and HRRR guidance
suggesting clouds will linger (with cigs lowering some) overnight
before sufficient mixing develops Tuesday morning to help scatter
and clear the cloud cover. That said, expect BPT will be the lone
terminal to stay VFR through the period, with just some SCT low
clouds overnight. MVFR cigs are expected to reform at the LA
terminals between 04-07Z, with at worst some IFR cigs for a few
hours late tonight at AEX/LFT/ARA. All sites should return to VFR
by mid to late Tuesday morning, with N winds 5 to 10 KT.
24
PREV DISCUSSION... /issued 356 PM CST Mon Dec 20 2021/
SHORT TERM [Today through 12Z Thursday]...
Showers have mostly moved out of the area, with only a few left in
the eastern part of the area. Cloud cover has decreased enough in
the western portions of the area to allow for a short warm up
into the low 50s. Areas to the east will likely remain in the 40s
for the high today with significant cloud cover still present
while passing peak heating for the day.
Temperatures are expected to drop significantly tonight as low
cloud cover will be expected. Temperatures are expected to drop
into the mid to upper 30s throughout much of the area overnight.
High pressure will build into the area which will allow for low
cloud cover over the next several days with a warming trend.
55
LONG TERM [Thursday through next Monday]...
At the beginning of the period surface high pressure will be located
over roughly the southeast US and Mid-Atlantic coast and some
resemblance of this high pressure system will remain over that area
during the period and ridge into the forecast area. This will allow
southerly flow from the Gulf and a return to the unseasonably warm
and humid conditions.
Guidance is in fairly good agreement with temperatures. The values
from the National Blend of Models was used in the forecast and these
are close to the ensemble means of both the GFS/ECMWF. Therefore,
daytime high temperatures and overnight lows will be some 15 to 20
degrees above climo norms. Basically the forecast overnight lows
will be what the normal daytime high would be, and these high/low
readings would be more like what you would expect in April.
With it being the Christmas Holiday weekend this is probably not
good news to those wanting to have temperatures and conditions more
in line with the holiday.
Further looking at the climo for Christmas, the forecast values are
close to the all time Christmas record highs.
Climate Site..........Forecast High....Normal High.....Record High...
Lake Charles..............78F..............64F...........79F in 2016.
Beaumont/Port Arthur......79F..............64F...........82F in 2015.
Alexandria................78F..............60F...........81F in 1942.
Lafayette.................79F..............63F...........80F in 2016.
New Iberia................80F..............64F...........81F in 2016.
During this period a mainly benign zonal pattern in the upper levels
will keep any northern stream storm systems to the north. That,
along with an upper level ridge over the Gulf of Mexico expanding
northward into the forecast, will not expect any significant shower
activity or rainfall, as drier air in the mid/upper levels will keep
the atmosphere capped.
The main concern during this time frame could be the fog potential,
Normally when we see this unseasonably warm and muggy conditions
during the winter season, we normal see fog. Looking back at the
times it was this warm during Christmas, there was also fog
reported. With dewpoints expected to above near shore waters
temperatures by Christmas Eve night into the weekend, and the
southerly flow, there is probably a good bet at this time for low
stratus and fog, just too early to say if low ceilings or dense fog
will be the bigger problem. So it looks like Santa might need to use
Rudolph`s shiny red nose to navigate around the area.
Only other note during the period could be some quite breezy
conditions on Friday (Christmas Eve) as decent looking surface low
traveling from the Plains to the Midwest could tighten the pressure
gradient with the high to the east. Marine wind hazards, or even a
wind advisory over land areas, will be possible during that day.
Rua
LCH WATCHES/WARNINGS/ADVISORIES...
LA...None.
TX...None.
GM...Small Craft Exercise Caution until midnight CST tonight for
GMZ470-472-475.
&&
.PRELIMINARY POINT TEMPS/POPS...
AEX 34 57 36 63 / 0 0 0 0
LCH 36 58 39 65 / 0 0 0 0
LFT 37 57 38 64 / 0 0 0 0
BPT 37 60 41 66 / 0 0 0 0
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...None.
TX...None.
GM...Small Craft Exercise Caution until midnight CST tonight for
GMZ470-472-475.
&&
$$
Area Forecast Discussion
National Weather Service Melbourne FL
406 PM EST Mon Dec 20 2021
.DISCUSSION...
...Flood Watch from Volusia to Indian River Through Tonight...
...Strong to Severe Storms Possible Tuesday...
...Hazardous Boating Conditions Continuing Through Mid Week...
Current...A messy day for most of east central FL as marine showers
over the Atlantic move onshore in increasing northeast to east flow
with dense low stratus blanketing all of the Panhandle and most of
northeast and north central FL. All of this due to increasing
moisture ahead of an approaching currently centered over the central
Gulf of Mexico. Last night`s cold front has stalled over the FL
Straits today, which will interact with the nearing low over the
next 12 to 18 hours.
Earlier today, northerly winds maintained showers paralleling the
coastline restricting to just the coastal waters, however as winds
veer onshore, activity has now pressed farther onshore, now reaching
towards I-95 in Brevard County. Multiple rounds of light to moderate
showers will be expected for the Space and Treasure Coasts over the
next few hours with the HRRR really hitting hard an increase in
coverage by 4pm. WPC highlights these mentioned coastal areas in a
Marginal threat for excessive rainfall with a weak trough just
offshore enhancing the rainfall threat which explains the higher
coverage advertised by the HRRR. So far, upstream signal not latching
on to this higher coverage in the afternoon, but available moisture
supports the possibility so will not rule it out. PoPs through
sunset highest at the coast at 40%, tapering to 20% over the
interior, which honestly will likely be even lower. Dense stratus
keeps a stubborn hold for areas along and north of I-4 which has
kept temperatures below 70 degrees today.
Tonight...After sunset, marine shower and storm activity will
rapidly increase which is really the focus that prompted the
issuance of a Flood Watch earlier today. Rainfall totals along the
coast could easily surpass 3 to 4 inches, with locally higher
amounts up to 6 inches through daybreak, especially for areas east
of I-95. A brief look at severe parameters overnight suggest the
potential for rotation over the Atlantic (i.e. waterspouts), with
higher helicity values remaining just offshore. While activity will
push westward, embedded waterspouts should generally remain away
from the coast but cannot be completely ruled out nearing the
barrier islands.
By midnight, the stalled front south of the FL Keys is anticipated
to lift back northward as a warm front, captured by the surface low
poised to be just offshore from Tampa Bay later tonight. The
evolution and progress northward of the warm front tonight will have
a large impact on the outlook for severe weather tomorrow, but more
on that below. Coverage of stratus will only increase tonight, with
lowered ceilings anticipated nearly everywhere. As a result,
temperatures will range from the low 60s north of I-4 to the upper
60s to lower 70s for the Treasure Coast.
Tuesday...The next 24 hours will prove to be the most active period
we have seen in awhile (at least so far in December). The deepening
surface low will reach the west FL coast by daybreak with upper
support in a 500 mb closed low digging south near MS/LA. The surface
low will shift over the peninsula through the day, with good
agreement in the center tracking along I-4 from dawn until dusk,
exiting offshore Daytona Beach by sunset. Uncertainty in the severe
threat is still present tomorrow, as latest model runs favor a dry
slot encompassing much of the area, with drier air wrapping around
the southern periphery of the low and the cold front extending south
towards the Keys. Focus for stronger activity still appears to begin
soon after sunrise and lasting through the late morning to early
afternoon, with deep-layer of dry air arriving by the afternoon
hours. Forecast soundings support this thought, but dry air arriving
in the mid levels early will offer the potential for strong to
severe wind gusts. DCAPE increases rapidly after 12Z up to 1200 J/kg
by late morning, suggesting wind gusts of 50-60 mph will be possible
prior to noon along with the potential for a tornado or two. Heavy
rainfall will remain a threat tomorrow morning, but most of the
precip will fall prior to sunrise, with higher totals occurring in
embedded thunderstorms. All signs point to the severe threat rapidly
diminishing through the afternoon with the mentioned arrival of dry
air on the south side of the low. Rain chances continue above 80%
through midday trending down to 60% by the afternoon, although this
appears too high and will likely be reduced. Highs tomorrow will
struggle to reach 80 degrees across the area due to the dense clouds
and cooling rainfall.
Tue night...By Tue evening, the low pressure will be off the coast
of South Carolina and lifting to the northeast through the night.
As it moves away from the local area, the cold front will be
pushing south of the peninsula with drier air intrusion from the
northwest. The evening will be a transition period as the moisture
exits our area through the Atlantic. A few showers and storms
will still be possible over land but these will be either
dissipating or transiting toward the local Atlantic waters. Winds
will start the night from the west and will veer to the northwest
late. Lows will reflect the passage of a cold front as these are
forecast to drop to the upper 40s for interior Volusia/NE Lake,
mid 50s interior, upper 50s Martin county.
Wed-Sun (previous modified)...While the primary mid level short
wave ejects rapidly NE, a rather deep trough remains in place over
FL Wed, driving post frontal high pressure and much cooler/drier
air SE into FL. Model guidance has trended cooler through Wed
night, showing highs only in the L-M60s far north and U60s-70 far
south. Chilly Wed night with mins L40s north to U40s south.
Zonal flow takes hold through late week, with a broad mid level
ridge building from the GOMEX across FL next weekend. Post-
frontal high pressure settles SE across the peninsula through late
week and this weekend. This will keep dry weather in place with
steadily warming temps through the period. U60s-L70s/M40s-L50s
Thu, M-U70s/ L- M50s Fri-Sat, and U70s-80F/M-U50s Sun and Mon.
&&
.AVIATION...
Prevailing MVFR/IFR conditions are expected through the TAF period
with drops to LIFR possible through midday tomorrow. Numerous
showers will continue at coastal terminals through the overnight
hours with the potential for embedded thunderstorms into the evening
and again tomorrow morning. A surface low pressure system will
approach the west FL coast through the overnight, crossing the
peninsula through the day on Tuesday. Impacts expected at nearly all
terminals over the next 24 hours, with SHRA at the coast and low
stratus prevailing across the interior. Shower activity will become
widespread overnight and last through 15-16Z tomorrow with less
confidence in terminals south of KMLB. East winds will increase this
afternoon with gusts to 20 knots, diminishing briefly overnight and
veering south to southwest by Tuesday, increasing again by mid
morning. VFR conditions will gradually arrive late tomorrow, just
beyond the end of the current TAF period as the low drifts northeast
from KDAB late in the day.
&&
.MARINE...
Tonight-Tomorrow...Hazardous boating conditions will continue
through late Tuesday as east to northeast winds increase this
afternoon above 20 knots, reducing only briefly overnight and
veering southerly. Tomorrow, southwest winds increase rapidly to 20-
25 knots and gusts up to 30 knots across all Atlantic zones with
seas 6-8 ft spreading southward through the period. A Small Craft
Advisory remains in effect. Numerous to widespread showers prevail
this afternoon and overnight, with added potential for isolated
thunderstorms and a brief waterspout through mid morning Tuesday.
Tue night-Wed...Transition period on Tue night as the low
pressure lifts to the northeast and away from the local waters.
West winds over the offshore waters will start at 20-25 kt then
become northwest on Wed morning while decreasing through the day
to near 15 kt by afternoon. Meanwhile, nearshore will feel the
"shadow" of land and winds will be lower at 15-20 kt and seas 4-6
kt on Tue night decreasing to 10-15 kt and 4-5 ft on Wed.
Wed night-Sat...High pressure will build from the north and remain
over the area through Sat. Lingering seas of 5-7 ft on Wed night
will continue to subside and be 5 ft or below by Thu morning.
Winds below 15 kt through the rest of the forecast period.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 65 75 50 66 / 90 80 40 10
MCO 66 76 54 68 / 70 80 30 0
MLB 68 78 53 69 / 70 80 30 0
VRB 69 80 56 72 / 60 70 40 0
LEE 62 73 51 67 / 80 80 30 0
SFB 66 75 52 67 / 80 80 30 0
ORL 66 76 54 67 / 70 80 30 0
FPR 67 80 54 70 / 50 70 40 0
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...Flood Watch through late tonight for Coastal Volusia-Indian
River-Northern Brevard-Southern Brevard.
AM...Small Craft Advisory until 10 AM EST Wednesday for Flagler Beach
to Volusia-Brevard County Line 0-20 nm-Volusia-Brevard
County Line to Sebastian Inlet 0-20 nm.
Small Craft Advisory until 10 PM EST Wednesday for Sebastian
Inlet to Jupiter Inlet 20-60 nm.
Small Craft Advisory until 10 PM EST Wednesday for Flagler Beach
to Volusia-Brevard County Line 20-60 nm-Volusia-Brevard
County Line to Sebastian Inlet 20-60 nm.
Small Craft Advisory from 7 AM Tuesday to 10 AM EST Wednesday
for Sebastian Inlet to Jupiter Inlet 0-20 nm.
&&
$$
Smith/Negron/Combs
Area Forecast Discussion
National Weather Service Marquette MI
719 PM EST Mon Dec 20 2021
.SHORT TERM...(This evening through Tuesday)
Issued at 326 PM EST MON DEC 20 2021
RAP analysis and GOES imagery show a shrtwv trof and cold front
passing over the UP this afternoon as a sharp band of snow is
dropping south along this frontal axis. Temperatures have slowly
fallen across the west and central today as the colder air advects
in behind the front. It`s become a bit blustery, especially across
the Keweenaw where gusts have been around 30mph or so through most
of the day. Some lake-effect will develop and continue this evening
into tonight, but accumulations look on the low-end. Inversion
heights are quite low, with dry air moving in behind the front.
While there is decent instability and saturation through 3-4kft,
this won`t allow much more than some lighter snow showers. Across
the west half, with inversion heights near 4kft, dropping to around
3kft by tomorrow morning, should see light snow continue through the
evening, winding down overnight tonight. South towards IWD,
conditions look more bleak for snow, with inversions falling even
lower and sooner as sfc high pressure skirts by just to the SW
tonight. Conditions across the east are a little more favorable,
with inversions around 5kft, dropping to 3kft by tomorrow morning.
Snowfall amount of an inch or two by tomorrow morning will be
possible. Temps tonight will be on the cooler side, potentially
falling to around or slightly blo 0 along the Wisconsin state line
with lighter winds developing and some clearing potential with the
high pressure moving through.
By tomorrow, a quick-moving clipper system will ride in along a 70kt
500mb flow and 100kt jet. WAA/isentropic ascent will get some light
snow going around 12Z across the west, quickly spreading over the UP
by lunch time. There is pretty strong forcing with FGEN and jet
moving overhead and this forcing remains well within a deep DGZ.
Model soundings suggest 12-14kft deep DGZ with strong forcing
throughout the column, so SLRs will be on the higher side for
synoptic snow...somewhere in the 17-20:1 range. With mean winds
through the column of 30-40kt, could see some breaking dendrites
though. Across the east, southerly flow off Lake Michigan with
inversion temps near -14 to -15C will be more than enough to get an
additional enhancement of both QPF and forcing. While most of the UP
will see lighter snow throughout the morning and afternoon up to
half an inch an hour, HREF suggests a 4-5 hour period of 1+ inch an
hour across portions of the east.
All this considered, went with an advisory across the western
counties for a combination of synoptic and trailing LES tomorrow
through early tomorrow night. Snowfall of 3 to 6, locally up to 8
inches across Gogebic and Ontonagon over 18 hours is reasonable.
Opted to go with a warning across southern Schoolcraft and a high-
end advy for the surrounding counties for tomorrow afternoon through
evening. As mentioned, there is potential for 1+ inch an hour from
around lunch time through dinnertime along US2 from around Thompson
through Naubinway, north to around M28 from Seney to Newberry.
Totals across the east will be around 4 to 6 inches from Nahma to
Shingleton east to Seul Choix to Newberry, with locally higher
amounts to around 8 inches from around Manistique to Curtis.
.LONG TERM...(Tuesday night through Monday)
Issued at 413 PM EST MON DEC 20 2021
Flow across N America for at least the next 10 days will be driven
by an anomalously strong ridge over the N Pacific and Aleutians,
extending to the Bering Sea at times. This will force a downstream
western N America trof, which in turn will tend to force ridging
farther downstream over eastern N America. However, a -AO and -NAO
are also present. The AO is forecast to remain in the negative phase
while the NAO remains mostly in the negative phase. The negative
phase of both should work to temper eastern ridging and the
potential warmth downstream into the Great Lakes that would result
from the mean western N America trof. End result of this pattern
will be a series of shortwaves ejecting from the western trof with
associated sfc low presures tracking across the Great Lakes region.
Amplitude of western troffing/eastern ridging at the time of the
passage of each wave will determine how much warm air surges
northward with each. Waves will affect the Upper Great Lakes on Tue,
Thu, Christmas Eve, and probably early next week. The wave Tue will
be an accumulating snow producer, the wave Thu will be a minor snow
producer, the wave for Christmas Eve will likely feature mixed pcpn,
including rain for at least some of Upper MI, and the wave early
next week should be a snow producer. As it stands now, none of the
events beyond Tue look to produce significant pcpn. As for temps,
temps will fluctuate due to the series of shortwaves moving across
the Great Lakes region. However, overall thru early next week,
expect temps on the majority of days to be near normal or above
normal as the bulk of the coldest air will be held up over western
Canada underneath the mean western trof.
Beginning Tue night, the synoptic pcpn, including lake enhancement
off Lake MI from Tue`s shortwave will be exiting the e around 00z.
Attention then turns to nw flow LES in the wake of the system.
Fairly sharp sfc trof will drop se across Lake Superior during the
evening, providing at least a quick burst of mdt/hvy LES for much of
western and northern Upper MI. Given a still deep moisture profile
upwards of 10kft initially before thinning out thru the night and a
fairly well positioned DGZ in the convective layer, local
accumulations up to 4 inches could occur Tue night, but otherwise,
1-3 for the areas favored by nw flow LES.
Sfc high pres ridge will shift across the area on Wed, backing winds
to the s to sw and shifting lingering light LES offshore. The next
shortwave will then track e to the Great Lakes region on Thu. This
will be a weaker wave than its predecessor, but the waa/isentropic
ascent may still produce a short period of -sn for much of the fcst
area. Could be a little lake enhancement off Lake MI if air mass
does not modify too much under the waa regime.
Attention then turns to the Christmas Eve wave. This wave will move
from the W Coast Thu aftn and take on a negative tilt as it swings
to the Great Lakes Fri evening. Overall, the ECMWF has had a
consistently warmer look with this wave for many runs, indicating
pcpn will be rain as it arrives. For most of the recent runs, the
GFS/CMC have at least indicated some of the pcpn will fall as rain.
So, at this point, it appears that at least a portion of this pcpn
event will occur as rain and probably at most locations across Upper
MI. Could be some risk of -fzra, but that will remain more uncertain
until we get closer to the event. Expect a change back to snow as
the pcpn winds down/ends Fri night/early Christmas morning. There
are some indications a sfc low may develop along the cold front as
it passes across the Great Lakes region Fri evening. If so, there
could be an accumulating snowfall Fri night, probably over the
eastern fcst area, closer to the potential sfc low development.
Since this shortwave will remain an open wave as it swings negative
tilt across the area, pcpn will end quickly with its passage, and it
may not be cold enough on the backside for any LES to develop to
provide snowflakes in the air for Christmas Day. Otherwise, looks
generally like a quiet weekend unless the next wave early next week
arrives soon enough to bring some snow to the area late Sun instead
of only on Mon.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 654 PM EST MON DEC 20 2021
Low-level moisture with abundantly dry mid-levels will bring VFR to
MVFR conditions at all TAF sites through this evening. Could see
some light lake-effect snow showers at times, but vsbys aren`t
expected to fall too much with dry air. Gusty W to NW winds in the
wake of today`s cold fropa will persist through this evening. A
ridge building in from the west will then bring calming and
backing winds and perhaps some VFR conditions at IWD and SAW
tonight. Conditions will then fall into IFR, to potentially LIFR
vsbys, tomorrow as a system brings UP wide snow through the day.
&&
.MARINE...(For the 4 PM Lake Superior forecast issuance)
Issued at 326 PM EST MON DEC 20 2021
NW gales of around 35 knots will continue this evening across the
east half of the lake behind a cold front moving through this
afternoon. As sfc high pressure shifts through Wisconsin tonight, NW
winds will decrease through the evening, before becoming southerly
by tomorrow morning. A system will move overhead tomorrow afternoon,
as a low deepens overhead. This will bring a quick period of NW
gales of 35 to 40 knots across the central and eastern portions of
Superior for Tuesday night. Winds will relax again for Wednesday
with a ridge of high pressure overhead...but then the active pattern
will continue through the rest of the week with another low pressure
system moving through Christmas Eve through Christmas.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
Winter Weather Advisory from noon to 8 PM EST Tuesday for MIZ006-
007-013-085.
Winter Weather Advisory from 7 AM EST /6 AM CST/ Tuesday to 1 AM
EST /midnight CST/ Wednesday for MIZ001>003-009.
Winter Storm Warning from noon to 8 PM EST Tuesday for MIZ014.
Lake Superior...
Gale Watch from Tuesday evening through late Tuesday night for
LSZ249>251-266-267.
Gale Warning until 7 PM EST this evening for LSZ249>251-265>267.
Gale Watch from Tuesday evening through late Tuesday night for
LSZ248-265.
Lake Michigan...
None.
&&
$$
SHORT TERM...JAW
LONG TERM...Rolfson
AVIATION...Voss
MARINE...JAW