ThreatWeb

482 
FXUS61 KILN 211742
AFDILN

Area Forecast Discussion
National Weather Service Wilmington OH
1242 PM EST Thu Nov 21 2024

.SYNOPSIS...
An upper level low will migrate from the Great Lakes through the 
region through Friday before moving off to the east coast this
weekend. Multiple disturbances rotating around this low will bring
periods of snow showers mixed at times with rain showers, gusty winds,
and much cooler temperatures. Dry conditions return for the weekend 
as high pressure builds into the region with precipitation chances 
returning on Monday. Weekend temperatures return to seasonable 
normals.

&&

.NEAR TERM /THROUGH TONIGHT/...
Recent radar returns indicate the first wave of snowfall moving
southeast out of the CWA into JKL and RLXs areas. Some higher
reflectivity (~30dBZ or so) bands were embedded, dropping some
efficient snowfall rates. Observations indicate that road 
temperatures are still in the upper 30s to low 40s and ODOT
cameras show a lot of wet roads out there, but nothing snow
covered. 
As this pivots southeast out of the area, northwesterly flow
picks up in earnest, reinforcing the CAA and increasing our
winds. Sustained winds around 15-20 MPH with gusts to 30 MPH are
expected through the afternoon. With ambient temperatures in the
30s, stronger winds allow for "feels like" temperatures to drop
into the 20s. 


Previous discussion-> 
Deep mid level low centered over Lower 
Michigan to track across northern Ohio today and into PA 
tonight. A disturbance to rotate around this low thru the area 
this morning. As a result snow showers moving across Central 
Indiana will track east across the area this morning, with the 
possibility of some banded heavier areas of snow. These snow 
showers will be scattered, but areas under heavier snow showers 
or bands could have temporary reductions to visibilities. Model 
solutions have generally trended slightly north with the best 
coverage of snow showers looking to occur along and just south 
of the I-70 corridor. Road temperatures are starting out warm so
the reduced visibility looks to be the main impact with this 
initial snow this morning. Some lighter snow showers may 
continue into the early afternoon. 

A second mid level disturbance and associated surface low to
rotate around the 5H low thru Indiana/southwest Ohio this
evening and into KY overnight. In response to this feature,
a steadier area of snow will move into the area late in the 
afternoon and into this evening. Model solutions have trended a
little west with the best coverage of snow across southeast
Indiana, Southwest Ohio and Northern Kentucky - where 1 to 2
inches of snow are possible prior to tapering off overnight. 

Most of the snow will accumulate on grassy/elevated surfaces but 
given that Metro model shows pavement temperatures beginning to
drop into the mid 30s after sunset, some impacts on roads will 
be possible. With it being the seasons first snowfall - have 
issued a winter weather advisory from 4 PM to 4 AM.  

Snowfall moves southeast out of the region overnight. 

Cooler temperatures only reach highs today from the mid 30s 
northwest to 40 over the southeast. Overnight lows fall to the 
mid 20s to around 30. 

West winds to gust up to 30 mph today and 25 mph overnight.

&&

.SHORT TERM /FRIDAY/...
Deep mid/upper level low to move off to the east coast with a 
an impulse rotating around that system dropping south across 
the region on Friday. This will result in more showers Friday 
which starts as a mix of rain and snow showers before changing 
over to all rain as low level temperatures warm up. 

Temperatures will still be below normal on Friday, with highs 
in the lower and middle 40s.

&&

.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
Precipitation will be exiting to the east to start the long term 
period Friday night. In the wake of the departing upper low, heights 
will rise and surface high pressure will build into the Ohio Valley 
from the southwest Saturday into early Sunday. Temperatures will be 
above normal.

The next mid-level disturbance and an associated surface low will 
move into the Upper Midwest states late Sunday into Monday. This 
will pull deeper moisture into the region and cause rain on Monday. 
Our period of mild temperatures will end behind the system Tuesday 
into Wednesday as cold surface high pressure builds in from the
west.

&&

.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
Recent radar reflectivities indicate residual snow showers
moving through all TAF sites, but these will end from west to
east within the next hour or two. VSBYs improve once snow
departs. CIGs remain MVFR with patches of VFR moving through for
the next several hours. Thursday afternoon winds remain out of
the west/northwest, around 10-15 knots with gusts up to 25
knots. Winds decrease slightly during the overnight hours. 

Snow associated with next disturbance can already be seen on
radar, moving into northwestern and central Indiana, making its
way toward the Tri- State and OH/IN border. 

Recent guidance has trended this snow farther west, so have
removed mention of precip from KCMH/KLCK TAFs. In terms of 
timing, widespread snow will move into the OH/IN border and Tri-
State area around 22Z. VSBYs and CIGs will drop to IFR in these
areas, with patchy LIFR possible with heavier snow. Snow tapers
off shortly after midnight and VSBYs improve, but CIGs likely 
stay IFR through the night. CIGs lift to MVFR nearer to sunrise 
(KCMH/KLCK stay MVFR all night, barring any stray precip moving 
through). 

Friday again has chances for precipitation in the forecast,
however, temperatures rise enough that any precip will fall as
rain. Want to note that Friday precip looks patchy and not at
all widespread, therefore have left mention out from all sites
except KCMH/KLCK. Winds pick up again on Friday, out of the west
around 10-15 knots, with gusts up to 25 knots possible. 


OUTLOOK... MVFR ceilings likely continuing through Friday and 
into Saturday.

&&

.ILN WATCHES/WARNINGS/ADVISORIES...
OH...Winter Weather Advisory from 4 PM this afternoon to 4 AM EST 
     Friday for OHZ042-060>062-070>072-077>081.
KY...Winter Weather Advisory from 4 PM this afternoon to 4 AM EST 
     Friday for KYZ089>100.
IN...Winter Weather Advisory from 4 PM this afternoon to 4 AM EST 
     Friday for INZ050-058-059-066-073>075-080.

&&

$$

SYNOPSIS...AR
NEAR TERM...CA/AR
SHORT TERM...AR
LONG TERM...
AVIATION...CA

209 
FXUS61 KBOX 181708
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
1208 PM EST Mon Nov 18 2024

.SYNOPSIS...
Dry weather and above normal temperatures will continue into 
Wednesday. A developing low pressure system will likely deliver
much needed, widespread meaningful rainfall Wednesday night and
Thursday. Showers will linger Thursday night and Friday with 
potential for some accumulating snow over the highest 
elevations. Gradually drying out next weekend and blustery.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...

920 AM Update...

* Plenty of sunshine develops with highs upper 50s - middle 60s

A shortwave crossing the region at mid-morning brought a few
brief sprinkles earlier this morning. Most of these have already
departed...but may see a brief sprinkle across southeast MA for
the next hour or so.

Otherwise...bulk of the clouds have already pushed to the I-95
corridor at mid morning and will continue to quickly depart. 
Plenty of sunshine will quickly overspread the region over the 
next 1-2 hours. Given the mild start...high temps should recover
into the upper 50s across the high terrain to mainly the lower 
to middle 60s elsewhere. These temps generally 10 degrees above 
normal for this time of year. Bufkit soundings indicate 
northwest wind gusts of 20-25 mph developing later today...but a
very nice day for second half of November across the region!

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...

Monday night surface high pressure and mid-level ridging sets up to 
the west and while the ridge deamplifies throughout Tuesday, should 
have strong enough surface high pressure to allow for mostly clear 
skies. Despite the clear skies overnight, not expecting strong 
radiational cooling because of stronger gusts. Morning lows are in 
the upper 30s and low 40s. Will rebound to the middle and upper 50s 
by early afternoon under sunshine. Gusts diminish Tuesday to 15 and 
20 mph. With minimum RH values between the upper 30s and low 50s 
(away from Cape Cod) we will coordinate messaging for Tuesday with 
the state fire weather partners.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...

Key Points..

* Dry with slightly above normal temps Wed

* Much needed widespread, meaningful rain late Wed night into Thu. 
  Showers lingering Thu night into Fri with potential for some 
  accumulating snow over the highest elevations in northern MA

* Still the risk of showers Sat, but gradually drying out through 
  the weekend with gusty winds

Tuesday night and Wednesday...

Quiet weather with high pres building into the region. Chilly night 
Tue night with decent radiational cooling, then nice temp recovery 
on Wed with highs reaching mid-upper 50s.

Wednesday night through Friday...

Pretty dynamic system will be impacting the region as anomalous 
upper low dives into the Ohio Valley before moving into New Eng. 
Strong upper level dynamics acting on PWATs around 1 inch will 
result in a period of widespread rainfall late Wed night into Thu. 
EPS and CMC ensembles showing high probs (80-100%) probs of at least 
0.50 inch QPF with GEFS having somewhat lower probs, while 1"+ probs 
are low to moderate (highest in upslope areas in the east slopes of 
the Berkshires and Worcester Hills). Confidence is fairly high in 
0.50 to 1 inch of rainfall for SNE, with potential for higher 
amounts in the higher terrain. 

It appears the precip will become more showery Thu night and Fri as 
the surface low lifts to the north with low level flow becoming SW, 
but the upper low will be moving overhead so potential for some 
heavier convective showers and additional rainfall. The other 
forecast concern for Thu night and Fri is potential for accumulating 
snow over the highest elevations in MA, especially the Berkshires as 
heights fall with the approach of the upper low. The track and 
intensification of the mid level and surface low will play a big 
role in the extent of snowfall, and this will not be resolved for at 
least a few days. Low level temps are marginal so snowfall will be 
highly elevation dependent but some accums are certainly possible. 
The deterministic GFS snowfall continues to fall well outside of the 
90th percentile of its ensemble distribution, so it is a clear 
outlier.

Saturday and Sunday....

Improving conditions as the upper low gradually lifts northward into 
the Maritimes. Saturday will be the more unsettled day as the upper 
low and cold pool will be nearby. It will be gradually drying out 
Sat but the risk of showers will continue, then it looks mainly dry 
with NW flow next Sunday. Blustery and cool conditions next weekend 
with below normal temps.

&&

.AVIATION /17Z MONDAY THROUGH FRIDAY/...

Forecast Confidence Levels:

Low - less than 30 percent.
Moderate - 30 to 60 percent.
High - greater than 60 percent.

18z TAF Update...

This afternoon & tonight...High Confidence.

VFR. NW winds will gust to between 20 and 25 knots at times.
Strongest of those wind gusts will be across the interior this 
afternoon, but shift towards the coastal plain later tonight.

Tuesday...High Confidence.

VFR. NW winds of 5 to 15 knots with some 20 to 25 knot wind
gusts at times into mid afternoon.

Tuesday night...High Confidence.

VFR. Winds becoming Calm/Light with a continued NW direction.

KBOS Terminal...High Confidence in TAF.

KBDL Terminal...High Confidence in TAF.

Outlook /Wednesday through Friday/...

Wednesday: Mainly MVFR, with areas VFR possible. Breezy. Chance
RA.

Thursday: Mainly MVFR, with areas IFR possible. Breezy. RA.

Thursday Night: Mainly MVFR, with local IFR possible. Breezy.
RA likely.

Friday: Mainly MVFR, with local IFR possible. Breezy. Chance
RA.

&&

.MARINE...
Forecaster Confidence Levels:

Low - less than 30 percent.
Medium - 30 to 60 percent.
High - greater than 60 percent. 

Through Tuesday...High confidence.

* Small Craft Advisory for all waters except Narraganset Bay and
  Boston Harbor today and tonight, but could be extended into
  part of Tuesday. 

Seas between 2 and 4 ft today, increasing NW winds behind a 
front will then bring wind gusts around 25 kts late Monday and 
Monday night with seas increasing to 4-7 ft on the outer 
waters.

Tuesday seas are diminishing and area between 3-5 ft with gusts
less than 25 knots. 

Outlook /Tuesday Night through Friday/...

Tuesday Night: Winds less than 25 kt. Seas locally approaching
5 ft. 

Wednesday: Winds less than 25 kt. 

Wednesday Night: Winds less than 25 kt. Chance of rain. 

Thursday: Moderate risk for Small Craft Advisory winds with
gusts up to 30 kt. Areas of rough seas. Rain. 

Thursday Night: Moderate risk for Small Craft Advisory winds
with gusts up to 25 kt. Rough seas up to 10 ft. Rain. 

Friday: Winds less than 25 kt. Rough seas up to 10 ft. Rain
likely.

&&

.FIRE WEATHER...

* Special Weather Statement for 'Elevated Fire Weather Concerns'
  across southern New England today. 

While there are some improvement, minimum RH values are still on
the lower side, between 35 and 50%, plus gust up to 25 mph are
from the northwest today.

&&

.TIDES/COASTAL FLOODING...
* Coastal Flood Statement for eastern MA coast; including Cape
  Cod and Islands for Monday afternoon's high tide. 

Astronomical tides have peaked just under 12' MLLW and are slowly on 
the decline. Still, there will be minor coastal flooding, which is 
best described as sporadic and nuisance flooding, as the surge with 
Monday morning's high tide is close to 1 ft. A coastal flood 
statement is in effect for east coastal MA for the afternoon high 
tide.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...None.
RI...None.
MARINE...Small Craft Advisory from 7 PM this evening to 10 AM EST 
     Tuesday for ANZ231-251.
     Small Craft Advisory from 7 PM this evening to 7 AM EST 
     Tuesday for ANZ232>234.
     Small Craft Advisory from 4 PM this afternoon to 7 AM EST 
     Tuesday for ANZ235-237.
     Small Craft Advisory from 7 PM this evening to 1 PM EST 
     Tuesday for ANZ250-254-255.
     Small Craft Advisory until 1 PM EST Tuesday for ANZ256.

&&

$$

SYNOPSIS...KJC/Dooley
NEAR TERM...Frank
SHORT TERM...Dooley
LONG TERM...KJC
AVIATION...Frank/Dooley
MARINE...KJC/Dooley
FIRE WEATHER...KJC/Dooley
TIDES/COASTAL FLOODING...KJC/Dooley

415 
WUUS01 KWNS 190037
PTSDY1

DAY 1 CONVECTIVE OUTLOOK AREAL OUTLINE
NWS STORM PREDICTION CENTER NORMAN OK
0635 PM CST MON NOV 18 2024

VALID TIME 190100Z - 191200Z

PROBABILISTIC OUTLOOK POINTS DAY 1

... TORNADO ...

0.02   28809448 30129434 31619353 33219293 34339228 34419168
       33929131 32438976 31238810 30838777 30438759 29438757
0.05   28809437 29619430 30129426 30529399 31579339 33219280
       33319249 33119215 32299204 31259203 30069107 28708979
&&

... HAIL ...

&&

... WIND ...

0.05   28749461 30219446 32489326 34299249 35419192 35449158
       34959104 33919074 32578934 31928846 31528794 30568761
       29588752
0.15   28809436 30129426 30559399 31549340 33199279 33339248
       33129216 32309205 31249203 30049104 28698979
&&

CATEGORICAL OUTLOOK POINTS DAY 1

... CATEGORICAL ...

SLGT   28809437 30139425 30519400 31559340 32749296 33209279
       33329250 33129215 32279205 31259203 30059105 28698979
MRGL   28749460 30219445 30729420 32469326 34219252 35399192
       35449161 34989107 33919073 32578934 31528794 30578761
       29588752
TSTM   28129523 30609439 32529349 34239285 36889256 38579280
       39489370 39899500 39749607 39789724 40179796 40789816
       41629874 43259831 44569662 45009371 44619001 44168738
       42698411 41228321 37958382 35778534 32778532 28948710
       99999999 49552245 46342216 43552290 41762426 41742548

&&
THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 45 SSE
GLS 20 NW BPT 40 N BPT 20 SW IER 35 SSW ELD ELD 20 ENE ELD 40 E ELD
15 S MLU 20 SE ESF 40 NW HUM 50 SSW BVE.

THERE IS A MRGL RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 40 SSE
GLS 30 NW BPT 50 SE LFK 35 E SHV 35 W PBF 30 SSW BVX 20 S BVX 60 SSE
BVX 35 NNE GLH 40 WNW MEI 55 W GZH 25 WNW PNS 65 SSW PNS.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 70 SSE LBX 50 SSE LFK
20 ENE SHV 20 SE HOT 40 WNW UNO 35 W JEF 25 SSW CDJ 10 NNW STJ 35 SW
FNB 25 NE CNK 40 SE HSI 15 SSE GRI 25 ESE BUB 40 SSW MHE 20 NNE BKX
25 WNW MSP 20 SW CWA 15 E MTW 25 ESE LAN 30 ENE FDY 35 NW JKL 20 SW
CSV 15 NNE AUO 105 S PNS ...CONT... 50 N BLI 55 SE OLM 45 SSE EUG
CEC 65 W CEC.

204 
FXUS61 KCLE 220145
AFDCLE

Area Forecast Discussion
National Weather Service Cleveland OH
845 PM EST Thu Nov 21 2024

.SYNOPSIS...
Low pressure over the Great Lakes will merge with a low off the New 
England Coast tonight into Friday, leaving a surface trough 
lingering through Saturday. High pressure will nudge across the area 
on Sunday before another low pressure system impacts the region on 
Monday.

&&

.NEAR TERM /THROUGH FRIDAY NIGHT/...
Heavy band of lake effect snow has dropped between 3-6 inches of
snow in western Lake and Northeastern Cuyahoga County already
this evening. We are starting to see signs of the band starting
a southward shift which is expected to happen as the trough that
has been focused over Lake Erie finally pushes south this 
evening. Snowfall rates of 1 to 2 inches per hour have led to 
rapid accumulations but most of the snow is expected to push 
inland through 11 PM. This will bring more of a broad 1-2" of
snow to the rest of Cuyahoga and Geauga Counties and into
northern portions of the secondary snowbelt. As winds shift out
of the north we are still expected to see temperatures warm 
south of Lake Erie into the upper 30s after midnight with 
precipitation transitioning to a rain/snow mix or back to rain 
overnight. Some melting of the snow is likely overnight. 

Previous discussion...As an occluded low continues to impact 
the region into tonight, scattered snow showers are expected to 
continue. Given near freezing surface temperatures and a push of
colder air this evening, would not be surprised if some areas 
saw up to 0.5", especially in higher elevations. 

More notably is the band of lake effect snow that is currently 
residing over Lake Erie. As the aforementioned low begins to 
merge with a low pressure off the New England Coast, winds 
across the area will gradually shift to a more west-
northwesterly pattern. When this happens (expected sometimes 
between 21-23Z this evening) the aforementioned band of lake 
effect is expected to push inland. There is high model agreement
amongst hi-res guidance for heavy snow to occur across portions
of western Cuyahoga and Geauga Counties. The timing of this 
band is important to note as it will likely coincide with the 
evening rush hour and increase the likelihood of impacts. Given 
the warmer antecedent conditions, expect the first bit of snow 
to melt on contact before accumulating. However, with heavy 
rates of up to 1"/hr, visibilities will rapidly diminish and 
motorists should use caution and allow for extra time when 
traveling. As a result of the accumulating snow potential and 
the possible impacts, a Winter Weather Advisory has been issued 
until 12PM for the aforementioned counties.

Digging more into the nuanced aspects of this forecast through 
midnight tonight, there are multiple factors that could shift the 
forecast one way or another. To start off, models are consistent 
with strong omega forcing, a convergent boundary developing on 
the southern edge of Lake Erie, and very cold 850mb temperatures
of -5 to -7C pushing south which are all very conducive for 
lake effect showers, leaving much of the nuances to 
temperatures. Along the immediate lakeshore, much of the 
precipitation will remain as rain or a rain/snow mix as warm air
advects south off of the lake, but how far south this warming 
goes is a bit uncertain. Opted to decrease rain/increase snow 
potential along the higher terrain with colder temperatures 
expected. In addition, models suggest that there is a potential 
for more of a graupel/snow mix inland, although impacts will 
likely remain the same. To summarize, there is high confidence 
in an impactful lake effect band during the evening rush hour, 
but less confidence in snowfall totals associated with the band.


Tonight, precipitation chance should become isolated to the eastern 
portion of the CWA as the low merges in New England and leaves a 
surface trough over the area. With the occluded nature of the low, 
warmer air is actually expected to wrap around the center and result 
in warmer 850mb temperatures throughout the surface trough. As a 
result, precipitation should gradually change from snow to rain from 
north to south, ultimately becoming only rain by Friday morning. 
Although warmer, these 850mb temperatures coupled with a 
convergent boundary will result in a full transition to lake 
effect on Friday. The wind forecast will be critical in the 
placement of these showers. Currently, winds are expected to 
become more northerly throughout Friday, which has the potential
to result in a Lake Huron connection and areas along and east 
of I77 being impacted by widespread rain into Friday night. As 
the trough gradually shifts east Friday night, showers will 
follow suit and should shift to impacting primarily the snowbelt
by Saturday morning. 

Overnight lows tonight will drop into the upper 20s to low 30s, 
gradually increasing into the mid 30s Friday morning. Highs on 
Friday will climb into the low to mid 40s, remain nearly steady 
Friday night.

&&

.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
One more shortwave trough will rotate through the mean mid/upper 
longwave trough Friday night into Saturday morning as the closed low 
near New York City finally starts to drift into the Atlantic. Mid-
level PVA and enhanced low-level convergence as the trough crosses 
Lake Erie combined with continued NW flow across Lakes Huron and 
Erie will once again increase the coverage of lake-effect/lake 
enhanced showers Friday night into Saturday. H85 temps will have 
modified significantly by that time, with values of 0-2 C, and this 
will reduce the instability and prevent anything overly heavy. 
However, given the at least conditional instability, deep synoptic 
moisture, and enhanced lift, kept likely to categorical PoPs over NE 
Ohio and NW PA through midday Saturday. The lake-effect showers will 
very gradually taper off Saturday afternoon through Sunday morning 
over NE Ohio and NW PA as the flow backs southwesterly and drier air 
and a lowering inversion work in from the west in response to 
shortwave ridging slowly building across the Ohio Valley and 
southern Great Lakes. Lake-effect precip is almost always slower to 
end than guidance suggests, and there are hints at a final weak 
shortwave dropping through the exiting trough Saturday night, so 
maintained chance PoPs through Sunday. No snow is expected for the 
weekend as boundary layer temps will be too warm. The shortwave 
ridging combined with weak surface high pressure nosing into the 
Ohio Valley will finally bring dry conditions Sunday afternoon, but 
this won't last long before shower chances slowly return from west 
to east Sunday night as isentropic ascent ramps up ahead of the 
next system. More on that in the Long Term section.

Highs will range from the mid 40s to around 50 Saturday, warming 
slightly into the mid 40s to low 50s Sunday. Lows Saturday night 
will dip into the mid/upper 30s, with mid 30s to low 40s Sunday 
night.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
As mentioned above, another system will quickly follow for early 
next week since a very active pattern has finally developed after a 
quiet Fall. Quasi-zonal flow across the CONUS and mid/upper 
shortwave ridging over the southern Great Lakes Monday will somewhat 
break down to allow a fast moving mid/upper trough to cross the 
Great Lakes Monday night and Tuesday. This trough will deepen/dig 
slightly into the eastern Great Lakes by Wednesday, bringing another 
quick shot of cold air to the region. It will not be as cold as the 
previous airmass, with H85 temps averaging a marginal -5 C for lake-
effect, but it will lead to lake-effect rain/snow showers once again 
downwind of the lake. Expect widespread rain showers Monday as the 
cold front approaches and interacts with a 100-110 knot H3 jet, and 
this will transition to lake-effect rain and snow behind the front 
Monday night and Tuesday in the cold air advection. Wind direction 
and boundary layer moisture/shear are uncertain this many days out, 
but current indications are for a W to WNW flow, so placed the 
highest PoPs in the primary snowbelt of NE Ohio and NW PA. The lake-
effect precip will gradually taper off Tuesday night and Wednesday 
as the trough lifts out. Too early to think accumulations, but 
again, thermodynamics are marginal, so it would probably be hard to 
see much more than light accumulations on grassy surfaces Tuesday 
into Wednesday, mainly at night and away from the lakeshore. 

For Thursday into next weekend, deterministic and ensemble guidance 
continue to support a chunk of true arctic air moving into the 
northern Plains and Upper Midwest and eventually across the Great 
Lakes. This is in response to a blocking ridge developing over the 
North Pacific and Alaska which could bring more sustained cold 
through early December. Guidance has been suggesting a wave of low 
pressure to develop on the cold front Thursday or Friday, which 
would make sense given the dynamics, but track and strength are 
impossible to pinpoint 7 days out. At this time, brought in broad 
chance to likely PoPs Wednesday night into Thursday. The main 
message is that a rainy and windy system is possible around 
Thanksgiving followed by a cold weekend that could include some lake-
effect snow, depending on how everything aligns. Stay tuned!

&&

.AVIATION /00Z Friday THROUGH Tuesday/...
Heavy snow has been ongoing over Lake Erie and into the eastern
Cleveland suburbs as a trough has been nearly stationary over
Lake Erie. This trough is expected to push south of the lake
through 03Z and push this west to east band of snow south across
the metro area. Still expecting this band to bring moderate to
brief heavy snow to CLE for up to an hour which could lead to a
quick inch of snow. Snow is also likely to reach CAK/YNG with 
IFR possible but more in the 1-2 mile visibility range. ERI has 
been warmer and could see brief snow or a rain snow mix. Behind 
the trough, winds will shift to the north off warmer Lake Erie
and temperatures are expected to climb bringing a transition 
back to rain working north to south overnight. An increase in 
precipitation is also expected overnight into Friday at eastern 
terminals. Ceilings will tend to lower to IFR during the day on 
Friday as low pressure over eastern New York retrogrades 
westward. In NW Ohio brief snow showers are possible but will 
tend to be light with MVFR visibilities, mainly at TOL. 

Winds are starting off at southwesterly at less than 10 knots
but will veer to northwesterly and increase through the day on
Friday. Most sites will see winds gusting to around 25 knots on
Friday with locally up to 30 knots or higher at CLE and ERI
where stronger flow is expected off Lake Erie. 

Outlook...Non-VFR conditions will be possible Friday through 
Saturday in scattered lake effect rain showers, possibly mixed 
with snow showers at times early on Friday. Gusty winds from the
north and northwest up to 35 knots will also be possible Friday
through Saturday, especially areas closer to the lakeshore as 
as well NEOH and NWPA.

&&

.MARINE...
The lake will remain active over the next 5 days, typical for late 
November. A surface trough crossing the lake tonight as the upper 
low drifts southward will shift winds to the NW along with an 
increase in speeds to 20-30 knots late tonight and Friday. This will 
build waves to 6-10 feet before NW winds gradually taper to 15-25 
knots Friday night and Saturday while backing more westerly by 
Saturday night. Issued Small Craft headlines for the entire lake 
from tonight into the weekend, especially the central and eastern 
basins which will see higher winds and waves through midday Sunday. 
This is high confidence. However, there could be a marginal Gale (34 
knots) late tonight through Friday morning. This is low confidence 
since there is not much of an 850 mb jet compared to classic events. 
If it occurs, it would probably be due to the pressure gradient 
briefly tightening, but confidence was too low to issue a warning, 
so kept a Gale Watch at this time. As mentioned, it will definitely 
be a high end Small Craft Advisory. 

Winds will back to SW and briefly decrease to 5-15 knots Sunday into 
early Monday before WSW winds increase to 20-30 knots again late 
Monday into Tuesday, so additional headlines are likely at that 
time.

&&

.CLE WATCHES/WARNINGS/ADVISORIES...
OH...Winter Weather Advisory until midnight EST tonight for 
     OHZ011>013.
PA...None.
MARINE...Small Craft Advisory from 1 AM Friday to 10 AM EST Saturday 
     for LEZ142.
     Small Craft Advisory from 1 AM Friday to 7 PM EST Saturday for 
     LEZ143-144.
     Gale Watch from 4 AM EST Friday through Friday evening for 
     LEZ143>147-163>167.
     Small Craft Advisory until 7 AM EST Sunday for LEZ145>147.
     Small Craft Advisory from 1 AM Friday to 10 AM EST Sunday for 
     LEZ148-149.

&&

$$

SYNOPSIS...Campbell
NEAR TERM...Campbell/KEC
SHORT TERM...Garuckas
LONG TERM...Garuckas
AVIATION...KEC
MARINE...Garuckas

308 
CDUS43 KIND 210631
CLIGEZ

CLIMATE REPORT 
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
131 AM EST THU NOV 21 2024

...................................

...THE SHELBYVILLE IN CLIMATE SUMMARY FOR NOVEMBER 20 2024...

CLIMATE NORMAL PERIOD 1991 TO 2020
CLIMATE RECORD PERIOD 9999 TO 9999


WEATHER ITEM   OBSERVED TIME   NORMAL DEPARTURE LAST                  
                VALUE   (LST)  VALUE  FROM      YEAR                 
                                      NORMAL                       
.......................................................
TEMPERATURE (F)                                                          
 YESTERDAY                                                           
  MAXIMUM         54    309 PM  51      3       54                   
  MINIMUM         41   1149 PM  33      8       43                   
  AVERAGE         48            42      6       49                 

PRECIPITATION (IN)                                                    
  YESTERDAY        0.11          0.12  -0.01     0.08                 
  MONTH TO DATE    3.85          2.38   1.47     0.55                 
  SINCE SEP 1      6.41          8.72  -2.31     4.81                 
  SINCE JAN 1     41.63         38.94   2.69    32.09                 

DEGREE DAYS                                                           
 HEATING                                                              
  YESTERDAY       17            23     -6       16                    
  MONTH TO DATE  203           385   -182      291                    
  SINCE SEP 1    401           746   -345      540                    
  SINCE JUL 1    403           749   -346      540                    

 COOLING                                                              
  YESTERDAY        0             0      0        0                    
  MONTH TO DATE   15             0     15        2                    
  SINCE SEP 1    251           159     92      224                    
  SINCE JAN 1   1489          1148    341     1266                    
.......................................................


WIND (MPH)                                                            
  HIGHEST WIND SPEED    29   HIGHEST WIND DIRECTION    NW (300)       
  HIGHEST GUST SPEED    42   HIGHEST GUST DIRECTION    NW (300)       
  AVERAGE WIND SPEED    10.9                                        


SKY COVER                                                             
  AVERAGE SKY COVER 0.5                                                 


WEATHER CONDITIONS                                                    
THE FOLLOWING WEATHER WAS RECORDED YESTERDAY.                         
  LIGHT RAIN                                                          
  FOG                                                                 


RELATIVE HUMIDITY (PERCENT)
 HIGHEST    93           200 AM                                      
 LOWEST     41           800 PM                                      
 AVERAGE    67                                                        

..........................................................


THE SHELBYVILLE IN CLIMATE NORMALS FOR TODAY
                         NORMAL    RECORD    YEAR                     
 MAXIMUM TEMPERATURE (F)   51        MM        MM                      
 MINIMUM TEMPERATURE (F)   33        MM        MM                      


SUNRISE AND SUNSET                                                    
NOVEMBER 21 2024......SUNRISE   735 AM EST   SUNSET   523 PM EST     
NOVEMBER 22 2024......SUNRISE   736 AM EST   SUNSET   523 PM EST     


-  INDICATES NEGATIVE NUMBERS.
R  INDICATES RECORD WAS SET OR TIED.
MM INDICATES DATA IS MISSING.
T  INDICATES TRACE AMOUNT.




$$