Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 09/26/22
Area Forecast Discussion
National Weather Service Gaylord MI
1148 PM EDT Sun Sep 25 2022
.UPDATE...
Issued at 941 PM EDT Sun Sep 25 2022
Cool, damp, dreary, wet, chilly, raw. We`ll keep on keeping on.
Widespread light rain is occurring in eastern upper and far ne
lower MI. More vigorous shower activity is over portions of
northern Lake MI and nw lower MI. This is a mix of lake-effect
and leftover diurnal convection. Keeping an eye on whether any
sort of gusty winds emerge from this shower activity, though
actual diurnal instability and associated steepening of low-level
lapse rates was stronger to our w and s.
Shower activity will continue to be most vigorous in nw lower MI,
and locally heavy rain can be expected. Most recent RAP has
localized 1"+ rainfall amounts tonight from TVC to Wellston. (At
least it isn`t snow.)
&&
.NEAR TERM...(Through Tonight)
Issued at 315 PM EDT Sun Sep 25 2022
...Showery and Brisk Tonight...
High Impact Weather...None is expected, although a few rumbles of
thunder are possible near Lake Michigan.
Showers have increased as expected per APX radar and surface
observations. This trend will continue into this evening with
widespread showers expected across northwest lower and scattered
to numerous showers across the remainder of the region. This is
due to upper level disturbances rotating around a deepening area
of low pressure off to our east as well as decent over lake
instability. There could even be some embedded rumbles of thunder
near Lake Michigan overnight but nothing severe is anticipated.
Northwest winds will be gusty. Temperatures will drop off by a few
degrees with lows ranging from the mid 40s to low 50s.
&&
.SHORT TERM...(Monday through Wednesday)
Issued at 315 PM EDT Sun Sep 25 2022
High Impact Weather Potential: Low for now.
Pattern Synopsis:
Amplified longwave troughing will settle over southeast Canada and
the Great Lakes through the first half of the week. This system will
become increasingly vertically stacked through Monday, eventually
leading to the weakening of an associated surface cyclone meandering
east of the region as more favorable advections are cut off. This
troughing will begin to depart towards New England on Wednesday as a
large ridge slides over the Rockies and northern Great Plains.
Subsidence aloft at the inflection point of these upper-level
features will provide ample subsidence aloft that will begin to
build surface high pressure from the upper Midwest into the Great
Lakes by Wednesday evening.
Forecast Details:
Well-advertised cool, wet weather will continue across northern
Michigan through the first half of the week. The steadiest rainfall
during this stretch may be ongoing at the start of the period.
Forecast soundings display impressive moisture in place with
saturation that extends through the depth of the troposphere. This
moisture, combined with warm lake surface temperatures and a few
hundred J/kg of buoyancy will support lake effect rain showers into
Wednesday. A few rumbles of thunder cannot be ruled out given the
aforementioned instability. An additional 0.5 - 1.5" of rainfall on
top of what will have already fallen will be possible across
portions of northwest lower Michigan beginning Monday morning and
ending Tuesday morning. Lesser amounts are expected elsewhere.
Additional rainfall will continue into Wednesday as previously
mentioned, but accumulations appear to be around 0.5" or less at
this time.
Northwest winds will also pick up Monday and Tuesday afternoons,
gusting to 25-35 mph at times -- especially near the Lake Michigan
shoreline. Otherwise, temperatures will continue to cool through the
beginning of the week. Highs in the mid 50s are expected on Monday,
but will cool into the upper 40s and low 50s Tuesday and Wednesday.
Low temperatures may dip into the mid/upper 30s for some areas
Tuesday night/Wednesday morning, but sufficient cloud cover and
winds are currently expected to prevent frost formation.
.LONG TERM...(Wednesday night through Sunday)
Issued at 315 PM EDT Sun Sep 25 2022
High Impact Weather Potential: Widespread freeze expected Wednesday
night across interior northern Michigan.
Troughing will continue to slide over New England Wednesday night as
ridging moves over the Great Lakes through the end of the week.
Strong surface high pressure will build directly overhead Wednesday
night and encompass much of the Great Lakes through the long term
period. As advertised in previous forecast cycles, the main concern
will be widespread freeze conditions expected across interior
northern Michigan Wednesday night/early Thursday morning. Strong
high pressure will lead to clear skies and calm winds, resulting in
efficient radiational cooling overnight. Low temperatures are
expected to drop into the mid/upper 20s away from the lakeshores
with the potential for localized low-lying areas to dip into the
upper teens and low 20s before sunrise.
&&
.AVIATION...(For the 06Z TAFS through 06Z Monday night)
Issued at 1148 PM EDT Sun Sep 25 2022
VFR to MVFR tonight. Mostly MVFR Monday.
Plenty of moisture in place, and will remain in place, circulating
around low pressure just to our east. MVFR cigs will become more
widespread very late tonight and into Monday. Spotty showers will
occasionally/briefly reduce cigs/vsbys, especially into TVC/MBL
overnight/early Monday.
Nw winds will become gustier on Monday.
&&
.MARINE...
Issued at 315 PM EDT Sun Sep 25 2022
Northwest winds will continue to increase especially later
tonight as slowly deepening low pressure pushes east of the
region. Expect widespread small craft advisory conditions across
northern Lake Michigan...spreading across the remainder of our
nearshore waters on Monday. A few gale force gusts are expected
later tonight into at least Monday morning on parts of Lake
Michigan. Winds will gradually subside Monday night into Tuesday.
Definitely a wet period of weather the next few days, with periods
of showers right through Tuesday. Will need to also be on the
lookout for waterspouts and isolated thunderstorm potential.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...Beach Hazards Statement from 4 AM EDT Monday through Monday
evening for MIZ016-020-021-025-026-031-098-099.
LH...Small Craft Advisory until midnight EDT Monday night for
LHZ345>349.
LM...Small Craft Advisory until midnight EDT Monday night for LMZ323-
341-342-344.
Gale Warning until noon EDT Monday for LMZ345-346.
LS...Small Craft Advisory until midnight EDT Monday night for LSZ321-
322.
&&
$$
UPDATE...JZ
NEAR TERM...AJS
SHORT TERM...DJC
LONG TERM...DJC
AVIATION...JZ
MARINE...AJS
Area Forecast Discussion
National Weather Service Binghamton NY
937 PM EDT Sun Sep 25 2022
.SYNOPSIS...
A slow moving upper level trough will bring unsettled weather to
the region, with showers and a chance for thunderstorms expected
today and Monday. Cooler temperatures with showers are expected
Tuesday and Wednesday, with improving conditions on Thursday.
&&
.NEAR TERM /THROUGH MONDAY NIGHT/...
930 PM Update...
The band of storms that moved across PA, became weaker by the
time it made it to NEPA. This line associated with a cold front
has made it into the Catskills and will slowly exit the region
over the next couple of hours. Other than some showers in
northern NY, most of the region is dry and skies have cleared
out behind this line of showers. This clearing and light winds
will result in some patchy fog formation overnight. There is
some uncertainty on the fog formation though. While winds will
be light at the surface, just above, flow is strong. However,
BUFKIT soundings show shallow inversions present at many sites
that could trap low-level moisture and limit mixing. Model
guidance also show chances for visibilities to decrease late
tonight. Because of this, patchy fog was added to the river
valley locations. The rest of the forecast was doing well and
required few to no changes.
630 PM Update...
The main activity from this afternoon and early evening is
moving out of the region. Some scattered showers remain across
the region. While the HRRR is handling the activity in our CWA
well, the NAMNest is handling the line of storms moving across
PA better. This line will move through the Wyoming Valley this
evening. Gusty winds and heavy rain is expected with this line
and is not expected to be severe since instability is limited.
To update PoPs, a blend of the previous forecast, NBM, HRRR, and
NAMNest were used, while favoring a solution closer to the
NAMNest for this evening. Isolated to scattered showers will be
possible late tonight and into Monday morning. The hourly
temperatures were adjusted slightly cooler given the recent
observations. Otherwise the rest of the forecast was doing well
and needed only minor changes.
340 PM Update...
Some partial clearing over south-central NY and NE PA has
allowed some weak instability to develop, and together with
larger scale forcing, some areas of convective showers and
thunderstorms have developed. An isolated severe-criteria wind
gust can`t be ruled out from the Twin Tiers south into NE PA
through this evening, but the greater risk for severe
thunderstorms remains further to our south.
Otherwise, additional bands of showers will continue into the
evening hours, with more showers cropping up on Monday as we
remain in broad cyclonic flow with several weak impulses set to
rotate through the area. By Monday night, the risk of rainfall
will mainly shift north of the Thruway corridor.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
3 PM Update
Unsettled weather dominates this period, as a broad upper level
trough slowly pushes eastward through Central NY and Northeast
PA. This will keep shower chances in the forecast, along with
temperatures cooling to below average levels. Mean level flow
will generally be southwest which leads to the best chances for
rainfall generally closer to Lake Ontario and the immediate
northeastern side of the lake. Clouds will remain abundant over
the region as another round of PVA slides the slow moving
through and deeper moisture arrives with perhaps even a bit of
instability. This should combine for scattered to numerous
showers across CNY, with isolated to scattered showers possible
in NE PA. A few degrees cooler, despite breezy southwest winds
continuing. Highs are progged to be in the upper 50s to mid-60s.
By Tuesday night, the positively tilted upper level trough axis
finally crosses the region. Winds will shift more northwesterly
late at night, and this will increase the lake enhancement of
the rain showers for parts of our area. Cool with lows in the
40s to around 50 expected.
Much cooler air aloft and even at the surface moves into the region
for Wednesday into Wednesday night as 850mb temperatures fall to
around 0C. This will provide plenty of lake induced instability in
the now northwesterly flow over lake Ontario and the Finger Lakes
for additional scattered to numerous rain showers over CNY and at
least the northern tier of NE PA. It will be partly to mostly cloudy
Wednesday & Wednesday night, with NW winds 8-15 mph. High
temperatures only reach the 50s to perhaps lower 60s in the valleys
of the Twin tier and NE PA. Overnight lows Wednesday night are
currently forecast to reach the upper 30s to mid-40s...just warm
enough to keep all precip in the liquid form. Overall, total rainfall
Monday night through Wednesday night will be rather light for
our area...only 0.10 to 0.50 for CNY, and less than 0.25" in NE PA.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
3 PM Update
Upper level trough begins to exit the area off into New England and
Atlantic Canada by Thursday afternoon; at the same time a strong
surface high pressure system approaches from the Central Great Lakes
region. In the lower levels of the atmosphere, we will still
have a chilly northwest flow over CNY and NE PA through the day,
and this will likely mean some lingering lake effect/upslope
clouds and perhaps even an isolated shower. Ensemble means
continue to point to this period from as a fair bit below climo
means so I`ve continue to trend forecast temps below guidance.
By Thursday afternoon high pressure starts building over the
region with broad scale subsidence. This leads mean mainly
clear/sunny skies and lighter NE winds. With decoupling winds
and radiative cooling we anticipate another round of frost
across most of the region as lows dip into the 30s in most
locations. Temperatures gradually warm up Friday afternoon, into
the upper 50s to mid-60s for highs.
Heading into next weekend, the focus will be on the remnants of
Tropical Cyclone Ian. There remains too much uncertainty in the
latest guidance to pin down any details for our area this far
out in time. The strong high will continue to funnel dry air
into the region from the northeast, so this should at least act
to slow down any incoming rain from the remnants of Ian. For
now, continued to go with the NBM ensemble guidance, which keeps
Saturday dry over the area with increasing clouds. Then slight
chance to low end chances for showers were introduced into the
forecast for next Sunday, as a majority of the guidance shows
this potential. Temperatures continue a gradual warming trend
next weekend, getting back closer to seasonal values (highs
well into the 60s and lows in the 40s to around 50).
&&
.AVIATION /01Z MONDAY THROUGH FRIDAY/...
Stacked low pressure system will rotate east across the northern
Great Lakes/southern Ontario area through the next 24 hours with
broad cyclonic flow across central NY and ne PA. This cool flow
pattern will keep clouds around the region...ranging from low-
end VFR to MVFR tonight with light south/swly flow. There could
be periods of fuel alternate ceilings or IFR vsbys in fog
tonight due to the recent rain today creating a highly moist
near-sfc layer. However, ceilings will become mostly VFR after
14Z Monday with some showers on and off through the day...mainly
ITH north. The showers refocus north of SYR/RME after 22Z with
winds backing to a more southerly direction ahead of short wave
that will be starting to round the bottom of the long wave
trough.
Winds may gust up to 17 knots out of the west/sw from late
Monday morning into the afternoon.
Outlook...
Monday Night...Precipitation will continue to lift north, but
some patchy fog and low clouds are possible late in the night.
Tuesday and Wednesday...Restrictions likely with lake enhanced
rain showers expected.
Thursday and Friday...VFR likely.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...None.
NY...None.
&&
$$
SYNOPSIS...MPH
NEAR TERM...BTL/MPH
SHORT TERM...RLD
LONG TERM...RLD
AVIATION...BJT/MPH
Area Forecast Discussion
National Weather Service Columbia SC
738 PM EDT Sun Sep 25 2022
.SYNOPSIS...
A cold front, with limited moisture, will move through tonight, with
fair weather expected behind it for early to mid week. Moisture is
expected to increase late week into the weekend with possible
tropical impacts.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
Cold front still west of the Carolina Mountains at 23z. Showers
ahead of the surface front and mid level short wave trough in
eastern Tennessee. Moisture is somewhat limited east of the
Mountains. Can`t rule out a few light showers mainly across the
north Midlands and before midnight as short wave trough moves
through the area. But latest high resolution HRRR and other guidance
suggests showers will be quite limited so cut pops back.
The main front will not move into the forecast area until after
06z, then will slowly push into the eastern Midlands and
southern CSRA towards morning. Cloud cover ahead of the front
and approaching upper trough axis, along with continued
southwesterly low- level winds, will keep overnight lows a
little warmer, with readings between 60 and 65 expected.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY NIGHT/...
Beautiful weather is expected to continue to start the new workweek.
Well advertised cold front is going to be pushing through tonight
and tomorrow morning, with guidance generally pushing the front
through the forecast area between 4a and 9a on Monday. Behind this,
winds will shift out of the west and west-northwest and PWs will
tank to below 1" by Monday afternoon. Despite this, 850 hPa temps
still look fairly warm, so expect the combination of these things to
lead to temps in the mid and upper 80s again during the day. Temps
will likely be pretty cool on Monday night as dewpoints fall into
the mid 40s by Tuesday morning. A strong low level jet may keep
surface winds up just a bit, which could keep us from fully
radiating. Still gonna go a couple degrees below guidance as we`ll
likely still get pretty cool. Tuesday looks terrific; sunny skies
and highs in the upper 70s and low 80s as the strong surface high
from Canada begins to establish itself to our north. I don`t think
we`ll radiate as efficiently Tuesday night as we should begin seeing
an increase in gradient winds as that surface high creates a strong
pressure gradient on its southern side. As a result, the mid 50s are
reasonable for lows at this point.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
Still quite a bit of uncertainty in the forecast but details are
beginning to become a bit clearer. Synoptic pattern at the beginning
of this period is in decent agreement amongst the models and
ensembles, with a deep trough across the eastern CONUS. Meanwhile, a
strong ridge is forecast to build into the central US behind this.
At the surface, a very strong Canadian High pressure system will
build southeastward into the northern Plains and Great Lakes region.
This is expected to have a pressure between 1028mb and 1032mb, which
is in the 90th-99th percentile for this time of year according to
NAEFS. The larger fly in the ointment is one the placement of what
is now TS Ian. Generally, models have been shifting the position of
this TS into the eastern GOM (Gulf of Mexico) over the past 24h,
similar to the track the ECM and EC Ens have been pointing towards.
We`ll begin to feel Ian push up against the surface high over the
Great Lakes on Wednesday in the form of a strong surface pressure
gradient that will begin developing. We`ll likely see winds gust in
excess of 20 mph through the day out of the northeast. Otherwise,
Wednesday looks fairly nice. We`ll likely see some high clouds
pushing in from the south, and this will help keep temps below
normal across the area. Look for highs in the mid 70s, with
overnight lows in the mid and upper 50s. Clouds will continue
increasing overnight on Wednesday.
This is where the forecast gets tricky, but models are starting to
get a good handle on it. As I mentioned before, models are now
honing in on TS Ian being in the eastern GOM somewhere by Wednesday,
where it is forecast by NHC to be Hurricane strength. However,
there is still quite the spread amongst guidance on where
exactly Ian actually is in the eastern GOM. The GFS and ECM are
still ~150 miles apart, with the GFS on the western end of the
guidance and the ECM on the eastern end. What is interesting is
that despite this difference, the ECM, GFS, Canadian, and their
ensembles are all in decent agreement that the trough draws Ian
northward into Georgia and then into the TN Valley/central
Appalachians as a weakening low in the Fri-Sat period of next
week. This would likely bring impacts to the area, but the
extent of those is highly uncertain at this point given the high
model variance on eventual track. I am confident that moisture
will quickly increase on Thursday night ahead of Ian, with PWs
rising to near 2" across the area from south to north. This
should result in precipitation developing and possibly becoming
heavy on Friday and Friday night, with most models and ensembles
forecasting Ian or Ian`s remnants to push northeastward after
Saturday. Other than possible heavy rainfall and below normal
temps from widespread cloud cover (70s and possibly 60s for
highs) in the Thur-Sat period, I`m not really confident about
other details. Hopefully the rest of the 12z guidance and
subsequent models runs will give more details as to what will
actually occur once Ian is in the eastern GOM.
&&
.AVIATION /23Z SUNDAY THROUGH FRIDAY/...
VFR conditions likely continue over the next 24 hour period.
Expect dry weather tonight with light winds. Air air will
generally preclude fog or stratus development. AGS may again
experience a brief period of low visibilities due to shallow
fog however any impacts are expected to be brief with highest
chances around 09-10Z. Winds will be more out of the west
behind a front on Monday, with speeds between 5 and 10 knots in
the morning and around 10 kts in the afternoon with gusts up to
20 kts.
EXTENDED OUTLOOK...Possible restrictions associated with moisture
from tropical cyclone Ian mid to late this week.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
GA...None.
SC...None.
&&
$$
Area Forecast Discussion
National Weather Service Duluth MN
641 PM CDT Sun Sep 25 2022
.DISCUSSION...(This evening through Saturday)
Issued at 333 PM CDT Sun Sep 25 2022
Summary: Autumnal conditions will continue through mid-week. A
widespread freeze is possible Tuesday night and Wednesday morning.
Temperatures will trend warmer for the latter portion of the week
with daytime highs in the upper 50s to upper 60s Thursday into
next weekend.
At 20Z a broad upper-level trough was centered over the Great
Lakes with a seasonally strong 300 mb jet streak angling south-
southeastward out of Manitoba, the Northern Plains, and the Upper
Midwest. Several lobes of vorticity were noted both in the RAP
analysis and GOES-E water vapor imagery. Cold air advection atop
diurnally warmed surface conditions has resulted in numerous
showers and isolated storms over northeast Minnesota and northwest
Wisconsin. Another cold front was located across the Canadian
Prairies into far northern Ontario.
The upper-level trough will advance slowly eastward through
Monday night and will keep the Northland under strong cyclonic
flow aloft and cold air advection. Showers should become less
numerous overnight. Isolated thunderstorms will continue through
this afternoon and will slowly dissipate with the loss of heating
this evening. Gusty northwest winds will weaken slightly overnight
and will otherwise persist through Monday. The wind will keep the
boundary layer mixed, limiting the frost threat tonight and
Monday morning. The Canadian cold front will move southeastward
across the Northland starting just after midnight in the Arrowhead
and during the afternoon over northwest Wisconsin. Low
temperatures will dip into the upper 30s for portion of northern
Minnesota with values in the low 40s along the North Shore,
central Minnesota, and northwest Wisconsin. Highs on Monday will
trend a little cooler, in the upper 40s and low 50s in the
Arrowhead to the upper 50s in central Minnesota and low to upper
50s in northwest Wisconsin.
Monday night through Thursday morning, the main concern shifts to
frost and freeze potential. High pressure will gradually drift
southward over the Northland in response to rising heights in the
wake of the upper-trough. Winds should weaken Monday night with
mostly clear skies. Low temperatures will dip in the low to upper
30s. Portions of northeast Minnesota and the Arrowhead could
experience their first freeze of the season Tuesday morning with
widespread frost likely. Temperatures tumble a few more degrees
Tuesday night and Wednesday morning with lows in the upper 20s
and low 30s. A widespread freeze is possible Tuesday night and
Wednesday morning. Lows in the 30s are expected again Wednesday
night and Thursday morning providing another chance of frost.
A gradual pattern shift will occur Wednesday into Thursday. An
upper-level ridge will push eastward into the Upper Midwest
Wednesday and Thursday. Low-level winds will turn southerly
ushering in warmer temps at 850 for Thursday. Highs will climb
into the upper 50s to low 60s. The southerly warm air advection
will continue through the end of the week keeping temps near
normal. There`s a chance of showers and perhaps a few storms next
Sunday. Confidence is low at this point due to downstream effects
from the various solutions for the eventual remnants of Ian.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 638 PM CDT Sun Sep 25 2022
Numerous showers and some scattered thunderstorms have been sliding
northwest to southeast through the afternoon. Some of these cells
have dropped pea sized hail as they traverse the region. Activity
will taper off over the next several hours with VFR conditions
expected. Gusty winds out of the northwest are expected to
continue through the evening but not be quite as fast as the
afternoon. There is some concern for low level wind shear
developing if surface winds manage to decrease overnight as winds
in the lower levels will remain quite accelerated. But for now we
believe the winds at the surface should remain breezy and prevent
this from happening.
&&
.MARINE...
Issued at 333 PM CDT Sun Sep 25 2022
Strong northwest winds of 15 to 25 knots with gusts 25 to 30
knots will continue tonight and Monday. Occasional gale-force
gusts of 35-40 knots are possible particularly near the Twin Ports
and the Outer Apostle Islands. A Small Craft Advisory remains in
effect for the nearshore waters. A Gale Warning may be needed
later tonight if persistent gales are observed. Isolated showers
and storms are likely through this evening and the strongest
storms may briefly product gusts of 35 to 40 knots.
Winds will gradually weaken and turn northerly Monday night and
Tuesday.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 43 55 36 53 / 20 10 10 0
INL 37 53 32 52 / 20 10 10 0
BRD 42 58 38 57 / 10 0 10 0
HYR 41 55 33 53 / 30 10 10 0
ASX 45 57 37 54 / 50 10 20 0
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
LS...Small Craft Advisory until 1 PM CDT Monday for LSZ121-140>143-
146>148-150.
Small Craft Advisory until 7 AM CDT Monday for LSZ144-145.
&&
$$
DISCUSSION...Huyck
AVIATION...Britt
MARINE...Huyck
Area Forecast Discussion
National Weather Service Quad Cities IA IL
619 PM CDT Sun Sep 25 2022
...AVIATION UPDATE...
.SYNOPSIS...
Issued at 221 PM CDT Sun Sep 25 2022
Dry conditions were observed across the region this afternoon, with
some partly to mostly sunny skies seen on the GOES-East satellite
imagery. Observation sites across the area are indicating current
wind gusts between 25 to 35 mph for most locations, with an isolated
gust of 41 mph observed at Burlington, IA early this afternoon.
&&
.SHORT TERM...(This evening through Monday)
Issued at 221 PM CDT Sun Sep 25 2022
Summary...gusty northwest winds this afternoon will gradually
subside this evening and overnight before strengthening once again
Monday. Overall, dry conditions will remain in the picture.
The large-scale pattern won`t change much over the next 36 hours,
with a longwave upper-level trough over the northeastern CONUS, and
a very large upper-level ridge axis centered over the Intermountain
West states. This pattern should support overall dry conditions
across the region, although we can`t rule out a stray shower late
this afternoon into the early evening over Stephenson county in
Illinois as a mid-level PVA impulse dives to the southeast. Forecast
rainfall amounts are expected to remain very light, if any.
Thanks to a tight surface pressure gradient and deep boundary layer
mixing, wind gusts today have ranged between 25 to 35 mph for most
locations, with an isolated 41 mph gust at Burlington around 1 PM.
Eventually, as the boundary layer decouples, the winds will taper
off this evening. However, winds will reintensify during the
daylight hours Monday. Model soundings from the GFS, NAM, and RAP
guidance suggests mixing heights on Monday shouldn`t be quite as
high as they were today, but gusts are still forecast to range
between 25 to 35 mph.
.LONG TERM...(Monday night through Sunday)
Issued at 221 PM CDT Sun Sep 25 2022
Summary...dry conditions will persist through the week, with more
fall-like temperatures expected. Our first opportunity for frost is
possible this week for Tuesday night/Wednesday morning, and perhaps
once again for Wednesday night/Thursday morning.
Overall, the synoptic pattern doesn`t change much, meaning dry
conditions will continue. In fact, a large, strong area of high
pressure is expected to build into the region Tuesday night and
remain in control through Friday. In fact, the NAEFS MSLP
climatological percentiles are indicating values greater than 97
percent of climatology, meaning this high pressure will be strong
for this time of the year, with central pressure progged around 1033
hPa. The surface high should help support lighter winds and clear
skies at night, resulting in efficient radiational cooling. Low
temperatures for Tuesday night and Wednesday night are forecast in
the middle to upper 30s for most locations, so some frosty
conditions are expected. Otherwise, high temperatures for this time
frame will be in the upper 50s into the 60s, with overnight lows in
the 40s. With the anticipated arrival of what is now Tropical Storm
Ian into Florida, that will help to block the large-scale
atmospheric movement, so expect this period of dry conditions to
last a while in our region. By next weekend, temperatures look to
warm up to closer to seasonal average, with highs back in the lower
70s for most locations.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 616 PM CDT Sun Sep 25 2022
Main aviation concern will be another gusty day Monday across the
area. All TAF sites are expected to remain VFR with gusts in the
20 to 30 kt range tomorrow.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
SYNOPSIS...Schultz
SHORT TERM...Schultz
LONG TERM...Schultz
AVIATION...Gibbs
Area Forecast Discussion
National Weather Service Grand Rapids MI
949 PM EDT Sun Sep 25 2022
LATEST UPDATE...
Update
.UPDATE...
Issued at 937 PM EDT Sun Sep 25 2022
The convection tracking through the CWA has started to show some
signs of weakening with the decrease in lightning activity.
Earlier we did increase POPs to account for the radar trends.
Gusts were high closer to Lake MI with multiple sites topping 35
knots with a few that approached 50 knots. Some power outages
occurred as well. Looking at the rest of the night...while storms
are still possible...they should not be as strong as the
instability is trending downward.
&&
.DISCUSSION...(This evening through next Sunday)
Issued at 300 PM EDT Sun Sep 25 2022
-- Strong storms possible mid-late evening tonight --
We continue to monitor the potential for some strong to locally
severe storms that could affect the area west of U.S-131 mid to late
evening tonight. SPC has pulled the Marginal risk of severe weather
to the U.S.-131 corridor for this evening, as was indicated they may
do that after coordination this morning.
We have showers that have been affecting the area for the last few
hours starting to wind down at the lakeshore and moving east out of
the area. These showers were associated with a well defined short
wave that is starting to push east of the area per WV imagery. The
visible satellite imagery shows some breaks developing in the clouds
in the wake of the first wave.
We are expecting to see another increase of showers by mid evening,
with potentially a line of storms moving in toward and just after
00z this evening. This line of storms will be driven by the more
potent short wave that is pushing into Central Wisconsin this
afternoon. The models and ensemble means are in fairly good
agreement showing a few hundred J/kg of CAPE over the lake ahead of
this wave. Then as the wave moves over the lake, it jumps to around
1,200 J/kg of MU/SB CAPE. Forecast soundings shows this instability
well.
These types of events tend to overperform given the strong heat and
moisture flux off of the mid 60s F lake water interacting with the
colder air aloft. The HRRR and HREF members are showing good
potential of gusty winds, which makes sense given the setup. Deep
layer shear is only around 30 knots, which could be better. The
storm outflow, and unstable conditions over the lake will help to
compensate for the ok shear. Mid level lapse rates around 7.0 C/km
will also help with some hail generation.
The thunder threat should drop a bit after this wave moves through
later this evening. We can not rule out an isolated storm along the
immediate lakeshore tonight and Monday with the upper low/trough and
associated cold pool firmly entrenched over the area.
-- Unsettled weather to persist through Tuesday and end Wednesday --
This cool, damp, and unsettled weather pattern will linger into at
least Tuesday for all of the area, before shifting more toward the
lakeshore for Wednesday, and then ending after that.
The cyclonic flow and cold pool aloft with the upper low in place
and jet stream to our south will help to ensure some showers will
persist. We will continue to see tough to time short waves move
through in the general NW flow. The showers will eventually be more
driven by lake effect processes as delta t`s will be around 20C with
inversion heights at least 9-10k ft high if not higher. NW flow
favored areas will see much of the shower activity.
Tuesday night and early Wednesday, the cyclonic flow will persist.
However, the orientation of the flow with ridging trying to build in
will turn the flow to NNE and push lake effect rain showers offshore
except near Little and Big Sable Points. We will see ridging build
in by Thursday, and bring seasonable temperatures and dry weather
for Thursday and Friday.
-- Some rain next weekend from "Ian"? --
We are watching the medium to longer range for next weekend for the
possibility of some rain making it to Michigan from "Ian". There
remains a lot of uncertainty with this. If Ian can miss the upper
trough moving out, it may meander a bit more west around the Bermuda
High and possibly bring some rain on its NW flank. If it were to
move further east, we would likely miss it, and stay dry and mild
with ridging overhead while it moves out of the way.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 655 PM EDT Sun Sep 25 2022
Gusty showers and thunderstorms will be on the increase for the
TAF sites in Southwest Lower MI to start the period. Radar trends
show the storms to the west of KAZO extending into eastern WI. The
strongest activity should occur prior to 04z here in Southwest
Lower MI. IFR and lower conditions look likely and wind gusts
could top 35 knots as the showers and thunderstorms roll through.
Widespread MVFR conditions should settle in overnight and continue
into Monday. There is a potential for the cloud bases to lift to
VFR in the afternoon but confidence on that happening were not
high enough to reflect the trend. Any stronger shower could
temporarily lower the conditions to IFR through the period.
&&
.MARINE...
Issued at 300 PM EDT Sun Sep 25 2022
We believe we have the upcoming wind/wave event handled well at this
point with the upgrade to the Gale Warning earlier. The Small Craft
Advisory in effect until 8 pm tonight looks good with winds
frequently gusting to around 20 knots or so, and waves at the buoys
and on webcams around 3-4 ft.
We expect that a line of storms will come through this evening,
mainly south of Grand Haven. These storms have a good potential for
producing winds of 40-50 knots. Then behind the storms, the winds
will stay up around 30-35 knots in the colder air filtering in
behind the line. There looks to be two or three surges of gales
after the storms this evening, through tomorrow evening.
We continue to advertise the potential of some waterspouts this
afternoon and evening with the colder air coming in over Lake
Michigan. The waterspout potential will likely go down a bit as the
stronger winds make the conditions a little more hostile for the
formation of waterspouts.
It looks like headlines are likely to persist through Tuesday night
before winds and waves will come down enough.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...Beach Hazards Statement through Wednesday morning for MIZ037-043-
050-056-064-071.
LM...Gale Warning until 8 PM EDT Monday for LMZ844>849.
&&
$$
UPDATE...MJS
DISCUSSION...NJJ
AVIATION...MJS
MARINE...NJJ
Area Forecast Discussion
National Weather Service Morristown TN
822 PM EDT Sun Sep 25 2022
...New UPDATE...
.UPDATE...
Issued at 813 PM EDT Sun Sep 25 2022
The threat of severe weather has ended across the forecast area
with a few isolated showers were ongoing. This activity is
associated with the last bit of energy translating through the
trough. The front will continue to move southeast and provide some
cooler air to the region. Have made some minor hourly temperature
and dewpoint tweaks overnight as well as tried to better refine
the hourly PoPs to account for the isolated showers. Expect these
to persist for the next couple of hours before dissipating or
moving out of the area.
&&
.SHORT TERM...
(This evening through Monday)
Issued at 256 PM EDT Sun Sep 25 2022
Key Messages:
1. Numerous showers and scattered thunderstorms will affect mainly
the northern half of the area through the rest of afternoon. The
potential for severe storms appears low.
2. A weak cold front will pass through the area this evening,
bringing a drier air mass and clear skies for Monday.
Discussion:
Coverage of showers has started to increase in SW VA and the
northern Cumberland Plateau early this afternoon as a cold front
moves E-SE across KY. The HRRR depicts the current storms expanding
and merging into a line that moves across the northern and central
TN Valley, then another line of storms along the cold front moves
through between 22-01Z. The potential for these storms to reach
severe levels appears to have lowered due to the extensive cloud
cover that has blanketed the northern half. There are still some
steep lapse rates, strong winds aloft, and a low WBZ height, so a
few strong storms with hail and gusty winds will be possible.
All showers should be out of the area by midnight as the front will
be located near the spine of the Appalachians by then. If winds drop
off to near calm tonight, then fog will likely develop. Will mention
patchy fog tonight. High pressure over the Plains and a dry NW flow
will build over the area through Monday. Since the main upper trough
axis will still be over the upper Midwest and not strongly
amplified, and the upper jet remains well north of our area, the
frontal passage will not bring a strong push of cold air. So highs on
Monday will be in the 70s across the Valley.
&&
.LONG TERM...
(Monday night through next Sunday)
Issued at 256 PM EDT Sun Sep 25 2022
Key Messages:
1. Cool mornings will accentuate the dry fall weather pattern
through Thursday.
2. Next best chance for rain will hinge on how Ian`s forecast and
exact track develops for Friday and Saturday.
Discussion:
The first part of the extended period will be dry, cool, fall
weather. A deep upper trough over the eastern US will persist
through midweek before exiting to the northeast. At the surface, a
reinforcing shot of cool air courtesy of a surface high coming out
of Canada will maintain the cool weather. Lows will be in the mid to
upper 40s for the Tennessee valley to begin the period before rising
into the 50s going into the weekend. Highs will be in the low 70s
all week.
Towards the end of the period, the remnants of Ian may be drawing
near East Tennessee. For any of our local residents who may be
traveling to the Gulf Coast this week, follow local officials`
orders and pay close attention to the National Hurricane Center`s
forecasts. For our area specifically, the ensembles bring Ian`s
remnants into the southern Appalachians by Saturday afternoon.
Continuing high uncertainty regarding the exact track of Ian will
determine the eventual magnitude and extent of impacts here as we
draw closer. For now, possibly heavy rain with some gusty winds
Friday into Saturday.
&&
.AVIATION...
(00Z TAFS)
Issued at 718 PM EDT Sun Sep 25 2022
The tail end of the convective line will be ending at KTRI over
the next few minutes. KTYS and KCHA will remain VFR the remainder
of the evening. Lowering visibilities will occur a couple hours
before sunrise at KTRI along with a lower ceiling. Current
thinking is IFR conditions but could drop to LIFR closer to
sunrise. After brief IFR, all TAF sites will be VFR.
&&
.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN 58 79 50 74 / 10 0 0 0
Knoxville McGhee Tyson Airport, TN 56 76 46 72 / 30 0 0 0
Oak Ridge, TN 54 77 45 71 / 20 0 0 0
Tri Cities Airport, TN 53 73 42 68 / 30 0 0 0
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&
$$
SHORT TERM...
LONG TERM....Wellington
AVIATION...