Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 09/23/18
Area Forecast Discussion
National Weather Service Green Bay WI
1057 PM CDT Sat Sep 22 2018
Updated aviation portion for 06Z TAF issuance
.SHORT TERM...Tonight and Sunday
Issued at 232 PM CDT Sat Sep 22 2018
The latest RAP analysis and satellite/radar imagery show high
pressure centered over Lower Michigan and extending west over
Wisconsin. Mostly clear skies are prevailing over most of north-
central and northeast WI with only spotty cu forming, though a
more widespread cu field may rotate north from southeast WI into
east-central WI later on this afternoon. Meanwhile to the north,
a cold front extends from North Dakota to far northern Lake
Superior. Ample low clouds and spotty showers are present along
the front. As this front moves south and high pressure exits to
the east, cloud trends and temps are the main forecast concerns.
Tonight...High pressure will slide east to the eastern Great Lakes
while a Canadian cold front sags into the Upper Peninsula. Mid-
clouds will likely pass over northern WI ahead of the front, while
locations over central and east-central WI should largely enjoy a
mostly clear evening. As the front draws closer, models are
aggressive pushing in a low stratus deck into far northern WI
late. Backed off a little on cloud trends, since think models are
too aggressive based off the latest satellite imagery. As a
result, dropped temps a little, especially in some of the cold
spots over central WI, where some patchy fog is possible late. But
dont think temps will get cold enough for frost.
Sunday...The front will effectively stall over the Upper Peninsula
and far northern WI. Brought mostly cloudy skies south of
Rhinelander during the morning, but should see the stratus evolve
into a cu field in the afternoon, as winds back around to the
south at 850mb. Wouldnt be surprised to see a few sprinkles or
spits near the U.P. border during the morning. With partly cloudy
skies over central and east-central WI, temps will range from the
upper 50s in the far north to the upper 60s in the south.
.LONG TERM...Sunday Night Through Saturday
Issued at 232 PM CDT Sat Sep 22 2018
Dry weather will continue through Monday, with weak ridging at the
surface and aloft.
A cold front will move through the area Late Monday night into
Tuesday, bringing a chance of showers and isolated thunderstorms.
On Monday night, pops will be highest in the northwest (near the
cold front) and far southeast (WAA and a surge of tropical
moisture, with PWATs around 1.5 inches). On Tuesday, the main
focus should be over the southeast half of the forecast area,
where the frontal passage will still be occurring. Instability is
progged to be fairly weak during this event, with the greatest
instability (CAPE 500-750 j/kg) occurring in the Fox Valley region
midday Tuesday.
A mostly dry period is anticipated during the middle of the week
as the forecast area remains on the northern periphery of a
strong high pressure system.
Another cold front is forecast to arrive late Wednesday night into
Thursday, along with the next chance of showers. This system will
have even less instability to work with than the previous, so
will only mention a small chance of storms over north central WI
Thursday afternoon.
High pressure should bring another mainly dry period for the end
of the work week, but models disagree on the arrival time of
precipitation for the weekend.
&&
.AVIATION...for 06Z TAF Issuance
Issued at 1057 PM CDT Sat Sep 22 2018
VFR conditions are likely through Sunday, as high
pressure moves slowly east. Patchy ground fog is possible late
tonight across mainly the western TAF sites. There will be some
high to mid clouds over the northern portions of the area which
will help to limit cloud cover. Any fog would quickly dissipate
early Sunday morning if it does form. Additionally, some MVFR
clouds may approach RHI late tonight into Sunday morning; however,
these should steadily lift into the day Sunday.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......Kieckbusch
AVIATION.......Cooley
Area Forecast Discussion
National Weather Service Lincoln IL
850 PM CDT Sat Sep 22 2018
.UPDATE...
Issued at 850 PM CDT Sat Sep 22 2018
High surface pressure will provide quiet weather and light winds
the rest of the overnight. The only clouds of note will be cirrus
clouds streaming across southeast Illinois, on the northern edge
of a moisture plume in the southern stream jet. No precipitation
is expected in our forecast area, with any light rain showers
remaining closer to the Ohio River Valley.
Based on minimum dewpoints during peak heating this afternoon, low
temps tonight look on track to drop into the mid to upper 40s in
our northern counties, with low to mid 50s S of I-70.
Only minor updates were needed this evening. The latest forecast
info is already available.
&&
.SHORT TERM...(This evening through Sunday)
ISSUED AT 315 PM CDT Sat Sep 22 2018
A widespread area of rain showers along and southeast of Robinson
to Flora line at mid afternoon is starting to diminish a bit past
few hours, but will continue to affect far southeast IL thru much
of tonight. Shield of mid/high clouds west along and se of a
Rantoul to Taylorville line and has been slowly pressing se. The
rain showers are due to overrunning along a frontal boundary
extending from south central TN into northern LA to weak 1011 mb
low pressure in northeast TX. Meanwhile 1026 mb high pressure over
the central Great Lakes was bringing in drier and cooler air into
central IL today on ENE winds of 5-15 mph. Some light rain
showers should mainly be southeast of Lawrence county on Sunday
with skies becoming partly sunny in southeast IL. Lows overnight
in the mid to upper 40s in central IL and 50-55F in southeast IL,
mildest along and south of highway 50 where clouds continue. Temps
warm closer to normal on Sunday with highs in the mid to upper
70s.
.LONG TERM...(Sunday night through Saturday)
ISSUED AT 315 PM CDT Sat Sep 22 2018
The 12Z forecast models push moisture nw into southeast IL by
overnight Sunday night with more overrunning along frontal
boundary to out south. Have just slight chance of rain showers in
far southeast IL Sunday evening, then better push of moisture nw
overnight Sunday night with isolated showers up to I-72 and good
chance of showers in southeast IL. Lows Sunday night in the mid
50s northern CWA and lower 60s in southeast IL.
Chance of rain showers mainly southeast of the IL river on Monday
with isolated thunderstorms se of I-55 Monday afternoon. Models
are trending slower with a cold front moving into the upper
Midwest Monday afternoon and Monday night and to keeps its
convection chances nw of the IL river valley. Have just a slight
chance of convection nw CWA Monday night. SPC Day3 outlook has
marginal risk of severe storms nw of IL Monday night. Highs Monday
similar to Sunday in the mid to upper 70s. Milder lows Monday
night in the lower 60s northern CWA and upper 60s in southeast IL.
The cold front to push se toward the IL river valley late Tue
afternoon and thru rest of CWA during Tue night. Have 50-60%
chance of showers and thunderstorms Tue and Tue evening, then
diminishing chances of showers from nw to se overnight Tue night
behind cold front. SPC Day4 outlook for Tue has 15% risk of severe
storms in far southeast IL for Tue afternoon/evening along with
risk of heavy rains southeast of I-70. Highs Tue in the upper 70s
and lower 80s.
Dry, cooler and less humid air arrives for Wed and Thu across CWA
as high pressure settles toward IL by Wed night. Highs Wed in the
upper 60s and lower 70s, coolest nw of I-55. Lows Wed night in
the upper 40s and lower 50s, with mid 40s by Galesburg. Highs Thu
mostly in the lower 70s as clouds increase from the nw during Thu
afternoon. An upper level trof digging into the Midwest Thu/Thu
night to keep best chances of showers north of central IL, though
forecast builder carried isolated light rain showers over IL
river valley Thu evening. Ecmwf model keeps rain showers south of
Ohio river and north of IL on Thu and Thu night, and models have
been trending drier. 1025 mb high pressure settling into IA/IL on
Friday to bring a fairly nice day with highs in the lower 70s, and
some upper 60s north of I-74. A disturbance tracking eastward over
IA, northern MO and into central/northern IL during Friday night
into Sat morning could bring chance of showers and isolated
thunderstorms to areas north of I-70. Highs Sat in the mid to
upper 70s with coolest readings north of I-74. Models have trended
warmer next weekend as upper level ridge builds further north
across the southern states and upper level trof/low near the
Pacific Coast next Sunday. Southeast IL looks drier and warm next
weekend with better chances of showers and possible thunderstorms
over northern/nw IL including northern CWA.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 659 PM CDT Sat Sep 22 2018
VFR conditions are forecast to continue across the central IL
terminal sites through 7 pm tomorrow. High pressure at the
surface and aloft will remain established across central IL,
providing minimal cloud cover and light E-NE winds. Sustained wind
speeds should remain less than 10 kt.
The GFS and NAMnest are hinting at some MVFR or IFR fog late
tonight, but the NAM, HRRR, and RAP have no fog at all. Therefore,
we are siding toward no fog of consequence with this TAF issuance.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Shimon
SHORT TERM...07
LONG TERM...07
AVIATION...Shimon
Area Forecast Discussion...UPDATED
National Weather Service Jackson MS
936 PM CDT Sat Sep 22 2018
.UPDATE...
Updated for evening discussion.
&&
.DISCUSSION...
The cold front is now stalling from the ArkLaTex through the
ArkLaMiss Delta and northeastward across the Mid South. Anafrontal
stratiform light rain is ongoing across much of Arkansas, NW
Louisiana, and parts of NW Mississippi. Ahead of the front,
convection remains active across the Golden Triangle. Elsewhere,
most precip has now tapered off and there are a few breaks in the
clouds as well. Through the overnight, storms over the
northeastern part of the forecast area will continue lifting
northeastward and out of the area. Light showers, and perhaps an
isolated storm, will remain possible across the Delta closer to
the front. Over the southeastern half of the area, a lull is
expected with the loss of daytime instability and as the best
mid/upper level forcing remains north and west of the area. Some
minor tweaks were made to forecast POP/Wx to account for current
radar trends, but otherwise no significant changes were made to
the forecast. /DL/
Prior discussion below:
Tonight through Sunday night: Mid afternoon water vapor imagery
and RAP analysis showed the circulation around a low in the
northern Gulf and a weak shortwave over northeast Texas. The low
in the Gulf was helping some drier air aloft spill over into east
Mississippi from Alabama while the shortwave over Texas was aiding
convection along a stalled front just northwest of our CWA. This
will lead to a greater coverage of showers and thunderstorms
continuing into the evening over the western half of our CWA. The
convection will see a distinct diurnal trend over much of our CWA
this evening but due to the proximity of the stalled boundary and
the approaching weak shortwave, convection in our northwest will
likely continue through Sunday. Mid afternoon surface analysis had
an 1011mb low over northeast Texas with the old stalled front
meandering across the Arkansas/Louisiana state line and then back
across northwest Mississippi. The surface low will linger over
Texas into Monday while gradually weakening while the shortwave
over Texas tracks northeast across our delta region Sunday. Wl
still have a very moist airmass in place with PWATs greater than
two inches Sunday and the combination of daytime heating and the
shortwave will lead to the greatest coverage of storms across the
northwest half of the CWA again. The rain and associated cloud
cover will hold afternoon high temperatures to near 80F while
highs over east Mississippi will top out near 90F again.
Monday through Friday: Come Monday wl still have our moist airmass
with PWATs in excess of two inches and a deep but somewhat light
southerly-southwesterly flow. Warmer than normal temperatures
will continue across the whole CWA and mainly diurnally driven
convection. Scattered to numerous coverage of storms is expected
both Monday and Tuesday. Models appear to be in a little better
agreement this afternoon that upper level troughing will deepen
over the central CONUS and support a cold front dropping into our
CWA Wednesday. Models do differ on timing and how far south the
cold front will push through our CWA with the Canadian blowing the
front south our CWA by Thursday morning. Consensus is slower and
wetter for our CWA until Friday. Thus, the chance for rain will
increase Wednesday ahead of the front and continue into Thursday
before drier air and surface high pressure move into our CWA from
the north. /22/
&&
.AVIATION...
00Z TAF discussion:
Scattered SHRA/TSRA across the area continue to pose the potential
for brief gusty winds and categorical reductions. The main concern
for this activity through the night will be west of the JAN/GTR
area including the ArkLaMiss Delta. Otherwise, MVFR ceilings will
likely persist throughout much of the TAF period at GLH and spread
into the GWO area by Sun morning, with occasional reductions to
IFR possible as a front remains in the area. Outside of GLH/GWO,
VFR conditions will prevail this evening, with brief reductions to
MVFR possible around daybreak Sunday. After limited shower
activity during the morning hours, redevelopment of SHRA/TSRA is
expected in the afternoon hours with the greatest potential for
being impacted again at sites over the northwest half of the area.
/DL/
&&
.PRELIMINARY POINT TEMPS/POPS...
Jackson 71 88 71 87 / 17 43 34 54
Meridian 70 91 71 88 / 13 19 24 52
Vicksburg 71 87 72 88 / 19 71 54 58
Hattiesburg 71 91 71 89 / 10 51 22 61
Natchez 70 87 72 86 / 16 61 40 65
Greenville 68 81 70 85 / 60 63 44 61
Greenwood 72 85 71 85 / 51 73 61 61
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...None.
LA...None.
AR...None.
&&
$$
Area Forecast Discussion
National Weather Service Lake Charles LA
946 PM CDT Sat Sep 22 2018
.DISCUSSION...
Wx map shows stationary frontal trough Central and Northeast Texas
through the ArkLaTex. Over our region, light SE to calm winds,
with temperatures in the mid/upper 70s, which will not likely
change much through sunrise. Radar showing all of afternoon
convection dissipated. Changes to forecast this evening was to
lower chances of showers & thunderstorms to 30%, keeping it 50% or
better by 4 AM. Latest HRRR & NAM12 guidance continues to show
increased lift across SE TX/SW LA after midnight, particularly
after 4 AM through the morning hours. Remaining forecast on track.
DML
&&
.PREV DISCUSSION... /issued 650 PM CDT Sat Sep 22 2018/
AVIATION...Rain and a few heavier showers continue to slowly
decay across the region, however additional showers will develop
along the coast late tonight then work inland through Sunday
morning. Patchy lower ceilings are also occurring and will
continue through the period. Winds will be light.
PREV DISCUSSION... /issued 412 PM CDT Sat Sep 22 2018/
DISCUSSION...
Latest U/A analysis continued to show an upper trof over north
central TX sandwiched between a ridge off the Carolina coast and
another over the Four Corners. An upper low was also noted over
the NE Gulf. At the SFC, low pressured was centered near DFW, with
a CDFNT trailing to the south near CRP and a WMFNT extending east
along the LA/AR border. Regional radars depict two main areas of
convective cells, one along the Atchafalaya into SC LA and
another from roughly LFK to GLS that is starting to ease into our
interior E TX counties. Areas of mainly stratiform rain are
between these two main areas.
Little in the way of substantive changes were made to the
forecast this afternoon, in what continues to look like a
relatively wet end to September.
In the short term, while no high resolution guidance has a
perfect grip on current radar trends, recent HRRR runs depicting
an eastward exit/winding down of the ERN area of convection along
with a continued intrusion of the convection to our west the rest
of the afternoon and into the evening appears to capture the
overall idea. As was the case last night, a relative lull in
inland activity is possible as the convection over E TX eventually
wanes, but additional development is expected once again during
the overnight hours into SUN morning.
The upper trof over TX and associated SFC low will sink slowly TWD
the SE tomorrow, with yet another active period of showers and
thunderstorms expected amid the very moist airmass in place. These
features are expected to slowly weaken MON and TUE, but the
moisture axis, while not quite as robust, will remain in place
thus keeping above normal rain chances in the forecast.
For the mid to latter part of the week, global models are in
general agreement on a broad upper trof digging into the Central
CONUS, helping nudge a weak frontal boundary into the region. They
differ on exactly how far south the boundary will get, with the
CMC the most aggressive and the GFS the least. Despite this, the
actual differences in sensible weather are generally minimal,
with good rain chances still around through this period.
13
MARINE...
High pressure extending into the northwest Gulf will maintain a
light to occasionally moderate south to southeast flow into the
coming week. Scattered to numerous showers and thunderstorms are
expected the next few days courtesy of a slow moving upper trof
over Central Texas and abundant tropical moisture.
13
&&
.PRELIMINARY POINT TEMPS/POPS...
AEX 72 86 71 87 / 50 60 40 60
LCH 74 85 74 87 / 50 70 40 40
LFT 74 88 74 88 / 50 60 30 60
BPT 75 84 74 87 / 50 70 50 40
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...None.
TX...None.
GM...None.
&&
$$
PUBLIC...08
Area Forecast Discussion
National Weather Service Louisville KY
942 PM EDT Sat Sep 22 2018
.Forecast Update...
Issued at 942 PM EDT Sat Sep 22 2018
Drying has moved into southern Indiana, temporarily turning the rain
off for most areas north of the Ohio River. The RAP has had a good
handle on this and does still show another wave of rain moving in
from pre-dawn into the mid morning hours for the reasons outlined in
the previous update. So while the radar doesn`t look very impressive
right now, won`t back off PoPs or QPF for early Sunday morning quite
yet.
Issued at 613 PM EDT Sat Sep 22 2018
...Some Flooding Problems May Begin to Develop Early Sunday
Morning...
A corridor of light rain, with pockets of moderate rain, stretches
from central Ohio to southeast Missouri this evening. This rain is
expected to continue into the overnight hours.
Late tonight and towards early Sunday morning an increase in
rainfall rates is expected in north central Kentucky and far
southern Indiana. This region will be under the right entrance
region of a small upper jet streak across Indiana and Ohio. The low
level jet is not expected to be very impressive, but there is a
small speed max of 20-30kt showing up in the data during the wee
hours of the morning, the nose of which will be pointed toward the I-
65 corridor. Isentropic lift will be present, though weak.
Nevertheless, precipitable water values will be in the 1.5-2 inch
range with a K Index in the mid 30s, and heavy rain is certainly a
threat.
Right now it looks like the wave of heaviest rain should move into
the Louisville metropolitan area around 4am or so, and into the Blue
Grass 1-3 hours later. 6-hour flash flood guidance (FFG) values are
lowest along the lower Kentucky River and Elkhorn Creek valleys, on
the order of 1.7-1.9 inches, with values more in the 2.25-2.75 inch
range over the rest of the Flash Flood Watch. One hour FFG numbers
are generally just over two inches, but do lower to 1.75" in some
locations. The aforementioned lower Kentucky River and Elkhorn Creek
basins have the lowest values, around 1.25".
The major rivers and streams are in pretty good shape at this time
and right now no river flooding is expected at the river forecast
points. Peaks Mill on Elkhorn Creek in Franklin County will likely
rise just above its action stage of 8 feet. It should be noted,
though, that the river forecasts are dependent on the rainfall
forecast, so if we get more/less rain or it falls in a different
location than forecast, then the river forecasts could change.
General flooding issues could begin to develop by sunrise Sunday
morning, especially in locations that flood easily such as urban
areas and low-lying spots with poor drainage.
&&
.Short Term...(This evening through Sunday)
Issued at 340 PM EDT Sat Sep 22 2018
A cold front stretches west to east from western Tennessee to far
east-central Kentucky on through eastern Kentucky. The front is
tilted northward with the 700 mb level of the front just north of
the Ohio River. Low level northward flow is carrying lots of
moisture and overrunning the front producing widespread stratiform
rain. With weak instability (around 250 J/kg), thunderstorms aren`t
expected, but a few isolated cells are still possible. This flow is
in response to the CWA sitting under the right entrance region of an
upper level jet.
Recent short term models have trended higher precipitation amounts
further south than earlier global models. Tonight, the low level jet
is expected to increase precipitable water amounts to near 2" along
the Ohio River with higher amounts south. Areas along the Ohio River
are expected to see higher rainfall amounts with 2-3" expected near
Harrison County, Indiana and areas east into the Bluegrass Region.
Tomorrow morning, the quasi-stationary front will continue to
produce showers that are expected to drift to the east into the
Bluegrass and northeastern Kentucky with a line of higher rainfall
values tailing off to the southwest towards Nashville, Tennessee.
The ground is more saturated east of Interstate 65 and a few
counties west along the Ohio River. This coupled with higher
forecast rain amounts were the deciding factors for a Flash Flood
Watch and its location.
This rainfall will keep temperatures down as well. The morning`s
lows will be in the upper 50s in southern Indiana to the mid 60s
along the Kentucky/Tennessee border. Tomorrow`s highs are mostly
near 70 with mid 70s near the Tennessee border and mid 60s around
the Bluegrass.
.Long Term...(Sunday night through Saturday)
Issued at 240 PM EDT Sat Sep 22 2018
...UNSETTLED AND WET SEVERAL DAYS...
Sunday night, the front to our south will lift north. Focus for
heavier rains will be close to this boundary and where another low-
level jet is expected to develop overnight and cause added
convergence. Depending on short-term rain amounts, we could see some
additional flooding develop toward the Monday morning commute, even
with lower total QPF. Current watch ends Sunday night and can wait
and make a local extension if necessary then. As Monday continues,
we should see a brief break in convection. However, as we will be in
the warm sector of a moist airmass, any heating should help to
develop at least scattered thunderstorms that linger into the
overnight hours.
Monday night, we likely will be more firmly into the warm sector,
but having said that most models continue to show some overnight
rainfall. Think this is a bit overdone, and will go a little under
the SuperBlend guidance this period...but not by much in case the
location of the front ends up closer to our area.
Tuesday, a cold front will move into the Midwest, providing some
focus between it and the Ohio Valley for some banded convection.
Timing for the front seems just a tad slower, with the GFS/GEFS
implying it could get to the Ohio River more Wednesday morning now.
The CMC/00Z Euro both show a little faster progression. A slower
front would mean storms getting into the region with less stability
to work with. Winds aloft still warrant a watch for severe weather
with any afternoon/evening convection moving through.
Continuing their differences the GFS suite shows that front
lingering around close enough to keep in some rain chances for the
end of the work week, whereas the CMC/00Z Euro both a drier Thu/Fri
forecast. Given the spread will not make any major changes to the
blended forecast here, which keeps in at least slight rain chances
for Saturday in a quasi-zonal flow aloft.
Temperatures generally should be near or below normal for highs and
near or above for lows.
&&
.Aviation...(00Z TAF Issuance)
Issued at 713 PM EDT Sat Sep 22 2018
The band of rain that has been training across southern Indiana and
the northwest half of Kentucky will continue to do so through the
overnight hours, accompanied by low ceilings. A wave of heavier rain
is expected to move into the SDF and LEX areas in the pre-dawn hours
and last into mid Sunday morning. Ceilings may lower slightly
further during this time. In the afternoon rain will become more
scattered as the morning wave moves off, but ceilings will remain
low.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
IN...Flash Flood Watch through Sunday evening for INZ090>092.
KY...Flash Flood Watch through Sunday evening for KYZ029>031-033>043-
045>049-054>057-066-067.
&&
$$
Update...13
Short Term...KDW
Long Term...RJS
Aviation...13
Area Forecast Discussion
National Weather Service Marquette MI
629 PM EDT Sat Sep 22 2018
.SHORT TERM...(This evening through Sunday)
Issued at 403 PM EDT SAT SEP 22 2018
WV imagery and RAP analysis indicated zonal flow across the nrn
CONUS. A shortwave was sliding through James Bay and nrn Ontario on
the periphery of a deep mid/upper level trough over Hudson Bay. At
the surface, a cold front extended from the srn end of James Bay to
northwest MN. WAA ahead of the front supported mid clouds from ne MN
into northern Upper Michigan. Otherwise, breezy sotuhwest winds and
sunshine have pushed temps into the lower 60s.
Tonight, expect the cold front to slide quickly southward across
Lake Superior tonight. 900-700 mb fgen associated with the front
will support post frontal -shra into the keweenaw by around midnight
and into the rest of north central Upper Michigan overnight.
Incrasing ene flow will also enhance pcpn chances/coverage for
upslope areas in north central Upper Michigan. With the moisture
only up to around 700 mb behind the front, expect pcpn as mainly
drizzle or very light rain.
Sunday, the areas of pcpn over the north will only slowly diminish
into early afternoon given the persistent low level moisture and
upslope flow. Highs will struggle to reach 50 north but should climb
to around 60 south where light se winds prevail south of the front.
.LONG TERM...(Sunday night through Saturday)
Issued at 339 PM EDT SAT SEP 22 2018
No significantly impactful weather expected in the long term.
WAA could bring some rain to the far northern CWA, mainly over Lake
Superior, Sun night.
During the day Mon looks pretty dry with breezy southerly winds as a
low approaches the region from the W. The low passes N of the CWA,
dragging a cold front/trough across the area Mon night into Tue
morning. Best rain coverage should be over the northern CWA, with
more scattered to isolated over the southern CWA.
A couple of shortwave troughs moving through the region Tue night
and Wed may bring some rain showers, but coverage looks limited.
850mb temps drop down around 1C on Wed, so NW winds may lead to some
showers downwind of Lake Superior.
A stronger trough will then move N of the area Thu, bringing chances
for showers along the trough axis Thu then behind the trough Thu
night and Fri as models show lake effect rain showers in NW flow
with 850mb temps around or less than 0C.
High temps will fall into the 50s for the most part Wed through Sat.
Frost will be possible at times, but will need to be fine tuned as
precip and cloud cover can be better sorted out.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 629 PM EDT SAT SEP 22 2018
VFR conditions will prevail at KIWD/KCMX/KSAW into the evening
hours. With passage of the cold front overnight, low MVFR cigs will
set in, and there may be some -shra at KCMX late this evening and at
KSAW late tonight into early Sunday. Cigs may fall to IFR at KCMX
but are more likely to drop to IFR at KSAW due to upslope
conditions.
&&
.MARINE...(For the 4 PM Lake Superior forecast issuance)
Issued at 403 PM EDT SAT SEP 22 2018
A cold front front will sweep across the lake tonight, bringing a
sharp wind shift to ne winds at 20-30kt which will continue through
Sun. These winds will again be strongest over the western part of
the lake. During Sun, there may be some gale force gusts over the w.
Another cold front will approach on Mon, and this will keep winds
mostly in the 20-30kt range, though the strongest winds will shift
to eastern Lake Superior as winds become southerly. There could be
some gale force gusts over the eastern part of the lake on Mon.
Winds will shift to the nw at 15-25kt for Tue in the wake of the
passing cold front. May slip in a day with winds mostly under 20kt
on Wed.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
None.
Lake Michigan...
None.
&&
$$
SHORT TERM...JLB
LONG TERM...Titus
AVIATION...07
MARINE...JLB