Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 03/06/24
Area Forecast Discussion
National Weather Service Grand Junction CO
442 PM MST Tue Mar 5 2024
.KEY MESSAGES...
- Weak disturbances will continue to move across the area over
the next few days bringing light snow to the northern and
central mountains and valleys.
- A stronger open wave is projected to pass by Thursday and
Friday. Some uncertainty still persists with this storm`s
track. Presently, accumulations favor the southern mountains
and northward along the Continental Divide.
- High pressure builds in for the weekend bringing a return to
dry and warm conditions.
&&
.SHORT TERM /THROUGH WEDNESDAY/...
Issued at 136 PM MST Tue Mar 5 2024
Radar returns are slowly diminishing this afternoon while
visible satellite is also showing cloud cover decreasing. This
follows as a disturbance moves over the area. Some light snow
continues for the northern valleys (Craig, Hayden, Steamboat
Springs) and from the central mountains up into the northern
mountains with clearing elsewhere. The good news is that since
we`re in March, most of the snow that falls on the roads is
melting. The bad news, the snow that falls overnight makes
things a bit tricky until a few hours after sunrise when roads
revert back to being just wet versus snowy/slushy. For the
remainder of today, light precip will continue in the same
general areas. Of note, the HREF and NAMNEST are indicating an
uptick for some snow over the central mountains late this
evening through 3AM. The HRRR disagrees and keeps the entire CWA
dry. The NBM is following the HRRR lead and lowering PoPS and
QPF across the CWA for much of the night. The NBM might be a bit
too aggressive with this downturn so later shifts may need to
bump up PoPS if the NEST turns out to be the way to go.
Not much change tomorrow as more banding is forecast to set up
with another round of snow expected. Like today, most snow that
falls overnight will melt quickly after the sun rises. Latest
guidance did bump up snowfall amounts through Wednesday evening
for the Flat Tops, and northern/central mountains but these
amounts still remain below advisory criteria. 2 to 4 inches is
still what`s expected but a few spots in the highest elevations
may reach around 6 inches. Midlevel instability still exists
with CAPE values of 200 to 400 J/kg being common where this
banding sets up. Thus, some very slight chances for a quick
rumble of thunder Wednesday afternoon exists. Wouldn`t expect it
but it`s happened in the past so a brief mention of this in the
forecast seems reasonable. Cloud and snow cover will dictate
high and low temps. Generally speaking, highs will be right
around or slightly below seasonal averages.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/...
Issued at 136 PM MST Tue Mar 5 2024
Thursday morning delivers what looks like the finishing touches
of a week-long push of spring adjacent/late winter weather here
on the West Slope. A strong southwesterly jet max carves out a
frontal boundary along a Baja California-Four Corners
trajectory. Before the jet pulls eastward Thursday, there should
be enough left-exit frontogenesis to deliver some appreciable
snowfall to our southern mountains, specifically the San Juans,
where it looks like winter highlights will factor in to the
forecast as we get closer to this event. Northward, we will see
lighter snowfall totals as moisture and forcing race away to the
Plains and we rely on cold air instability/shortwave energy in
the belly of the passing trough to deliver the goods. This will
likely deliver snowfall to much of the terrain across the CWA
through Friday, as we try to scour the last of the Pacific
moisture from this airmass ahead of an approaching ridge of high
pressure. Upper level moisture looks tapped out late Friday
night, with the exception of the southern Continental Divide,
where a few scattered snow showers will likely hang on into
Saturday. This will probably be good enough for an additional
few inches of snow on the eastern San Juans Saturday. Cool and
cloudy conditions on Thursday and Friday will usher in a warm up
on Saturday, when desert valleys out west will surge towards 60
again. Upvalley, temperatures will remain in the 30s and 40s
Saturday as we get rid of cloud cover and return March sunshine
to the formula.
Sunday afternoon will see the return of meaningful southerly
flow again, along with a generous warm up. Presently, it looks
like Sunday could be one of the warmest days of the forecast
period thanks to generous sunshine and subsidence overhead.
Temperatures will be widespread in the 50`s and perhaps a value
or two over the 60 mark. Deterministic models start hinting at
the next pattern shift Monday in the southwesterly flow ahead of
a trough coming ashore. Some invading cloud cover ahead of this
next wave would likely cool off the highs Monday afternoon.
Models are also bringing some more moisture into the CWA on
Tuesday, likely beginning another unsettled stretch of weather.
Spaghetti plots begin to unravel Monday and Tuesday hinting at
another stretch of troughy weather not unlike this week`s
pattern. If this is the case, the weekend warm up will cool back
off into a cloudy and cool period at the very end of this long
term forecast. March has arrived and is behaving as expected.
&&
.AVIATION /00Z TAFS THROUGH 00Z THURSDAY/...
Issued at 442 PM MST Tue Mar 5 2024
Unsettled and highly variable conditions are likely to persist
through the TAF period as a series of disturbances move through
the region. Intermittent, isolated to scattered mountain showers
will continue to cause ceilings and visibility to fluctuate in
the high elevations with brief periods of MVFR possible.
Ceilings will remain near or even below ILS breakpoints,
particularly near and north of I-70. Meanwhile, low elevation
terminals should stay mostly VFR for the next 24 hours. Winds
will primarily be light and terrain driven, but can become gusty
at times Wednesday afternoon near showers and across the high
elevation terminals in the south where winds aloft are stronger.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...None.
UT...None.
&&
$$
SHORT TERM...TGR
LONG TERM...LTB
AVIATION...TGJT
Area Forecast Discussion
National Weather Service Green Bay WI
544 PM CST Tue Mar 5 2024
Updated aviation portion for 00Z TAF issuance
.KEY MESSAGES...
- Relative humidities of 20 to 25 percent could produce
increased fire potential in north central Wisconsin Wednesday
afternoon.
- There is a chance (40-70 percent) for rain and snow Friday
into Saturday morning. Still high uncertainty if any
accumulating snow will occur.
&&
.DISCUSSION...
Issued at 203 PM CST Tue Mar 5 2024
Short Term...Tonight and Wednesday
The latest RAP analysis and satellite/radar imagery show a large
high pressure system centered across south-central Canada into the
far northern Great Plains. Blustery north to northeast winds
around the high are funneling in colder and drier air compared to
this time yesterday. Satellite-derived precipitable water are
estimated to be below 20% of normal over north-central and
northwest Wisconsin early this afternoon. Meanwhile, a compact
shortwave is spreading wintry weather across North Dakota and far
western Minnesota. This system should track over northeast
Minnesota later today into tonight. With the dry airmass remaining
across the region, forecast concerns mainly revolve around low
humidities and marine hazards.
Clouds...The high pressure system will slide northeast and north
of Lake Superior over the next 24 hours. But it will nose into the
western Great Lakes enough to maintain the very dry airmass
across the region. As a result, little to no cloud cover is
expected below 10 kft. Some high clouds will likely arrive
tonight, but they look thin on satellite imagery and should not
impact temps much.
Temps... Although the blustery northeast winds will subside
somewhat tonight, they will remain out of the northeast and likely
prevent winds from decoupling over northeast WI. However,
decoupling is expected over north-central WI and consequently
dropped low temps a few degrees. Slightly warmer 925mb temps
should result in max temps 2-3 degrees warmer on Wednesday.
Fire Weather...Low level mixing ratios suggest humidity levels
will approach critical levels over north-central WI on Wednesday
afternoon. However, sustained winds are expected to be relatively
light (under 10 mph) and fuels are not critically dry so will
forego any heightened fire weather products in this forecast
cycle.
Winds...Blustery northeast winds will gradually subside under 15
kts tonight before backing some on Wednesday. But the winds look
to subside a little slower than previous forecast indicated, so
extended the small craft advisory through 6 pm this evening.
Long Term...Wednesday Night Through Tuesday
Main focus for the extended period is Friday morning through
Saturday afternoon as a low pressure system passing just south of
the region brings the next chance for widespread rain and/or snow.
Otherwise, conditions for much of this weekend and early next
week trend dry.
Precipitation...With upper-level zonal flow setting up for
Thursday expect mostly dry conditions. Only, caveat is a compact
shortwave and surface low pressure system tracking across the
northern Plains and into the Arrowhead of MN then turning
northward toward Ontario that may bring some light snow to far
north-central WI late Thursday night. The best chance for light to
moderate area wide precipitation (40-70%) begins Friday morning
as a southern stream short-wave and associated surface low
pressure system push northeast across the upper-Midwest. Global
ensembles do show signs of frontogenetic forcing ahead of the main
surface low than could produce some locally heavier precipitation
Friday afternoon and evening. Thermal profiles indicate that the
precipitation type with this system will largely be dictated by
how deep the above freezing surface layer is. Current thinking is
that central, north-east and east-central WI will see primarily
rain Friday with periods of snow mixing in overnight into
Saturday, while areas of north-central WI will see mostly snow,
however, there is still considerable uncertainty with timing and
location of precipitation type transitions. Regardless any snow
snow accumulations should be light as ensemble guidance shows a
10-20% chance for over 2" across north-central and north-east WI.
High pressure then looks to build in Sunday returning dry
conditions to the region to end the weekend an into the early
parts of next week.
Temperatues...With mostly cloudy skies and winds having a more
northerly component for the end of this week and this weekend
temperatures are forecast to trend slightly cooler than recent
days, but with highs ranging from the upper 30s to low 50s
Thursday through Sunday there region will still be a few degrees
above normal for early March. Warmer air is expected to return
early next week as winds turn southwesterly. Highs are currently
forecast to be back in the mid 50s to low 60s next Monday and
Tuesday.
&&
.AVIATION...for 00Z TAF Issuance
Issued at 542 PM CST Tue Mar 5 2024
VFR conditions expected through the TAF period. Just some intervals
of mid and high clouds (120-250) moving through at times. The
very dry airmass in place across the region will minimize fog
potential tonight.
Northeast winds will subside to 5-15 kts tonight, staying elevated
closer the lakeshore.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
DISCUSSION.....MPC/GK
AVIATION.......JLA
Area Forecast Discussion...Updated
National Weather Service Lincoln IL
732 PM CST Tue Mar 5 2024
.KEY MESSAGES...
- A few showers and thunderstorms remain possible in southeast IL
this evening near a departing cold front this afternoon.
- Mild temperatures will stick around through the end of the week
with high temperatures peaking in the 50s to low 60s each afternoon.
- The next chance for precipitation is Thursday evening into
Saturday, with a few thunderstorms possible Friday afternoon and
evening.
&&
.UPDATE...
Issued at 732 PM CST Tue Mar 5 2024
Latest surface map shows the cold front was close to the Ohio
River, though showers continue to percolate just to its north. The
majority of these, with locally flooding rains, were about 20-25
miles east and south of Lawrenceville, though a few had recently
developed just south of Flora and also east of Robinson. Latest
HRRR shows this continuing for a few more hours, so some 20-30%
PoP`s were extended through the evening over far southeast parts
of the forecast area.
Elsewhere, clouds prevail, with the northern edge of the lower
cloud deck trying to make some southward progress past I-88. HRRR
and RAP guidance suggests some clearing could take place as far
east as I-55, and while the height of the clouds in this area will
show some improvement, a wholesale clearing seems a little more
skeptical. May be more of a partly cloudy scenario overnight,
though high clouds coming in from the west may negate things.
Temperatures generally are on track, with the coolest readings
(mid-upper 30s) west of I-55 and mid 40s south of I-70.
Geelhart
&&
.DISCUSSION...
Issued at 257 PM CST Tue Mar 5 2024
A cold front just southeast of I-70 as of 2 pm will continue to
shift slowly southeast of the Wabash River by 6 pm, with scattered
showers and a few thunderstorms possible again this afternoon as
lingering instability in the vicinity of the frontal zone continues.
Overnight, northerly flow behind the cold front will result in
cooler but still above normal temperatures as low cloud cover
lingers over most if not all of central IL as moisture remains
trapped below a low level inversion. Cloud cover combined with
around 10 mph north wind should hold back temperature falls
resulting in lows ranging from mid 30s NW of the Illinois River to
mid 40s south of I-70.
Cloud cover looks like it will linger especially over southeast IL
Wednesday, helping to hold temperatures down, although model time-
height plots show a thinning of the saturated layer, indicating some
breaks will be possible. Highs look to range from mid to upper 50s
across the area.
An axis of surface high pressure ridging looks to shift east of the
area on Thursday, as low pressure develops into the Plains as an
upper trough propagates east of the intermountain west. Warm
advection should allow precipitation to spread across central IL
Thursday night, with a cold front shifting through the area Friday
into Friday night. A model consensus suggests precipitation amounts
around an inch and a half, so this could have beneficial rainfall
over an extended period as conditions have been on the dry side over
all the past several weeks. Nevertheless, with enough instability
ahead of the cold front, some thunderstorms are possible Friday
afternoon into Friday evening, and there could be some locally
excessive amounts, and WPC depicts portions of the area in a
Marginal Risk for excessive rainfall. Temperatures will continue
well on the mild side Thursday into Friday with highs in the 50s to
lower 60s, then following the cold front 40s to lower 50s, closer to
normal, can be expected over the weekend.
Upper ridging should bring dry conditions and warming temperatures,
reaching the 60s again, by early next week.
37
&&
.AVIATION... (For the 00z TAFs through 00z Wednesday Evening)
Issued at 518 PM CST Tue Mar 5 2024
IFR ceilings continue over a large part of central Illinois this
evening, with some improvement to MVFR west of the Illinois River.
Not a lot of hope of that type of improvement near KCMI tonight,
though the remaining terminals may break through for a time. Based
on HREF probabilities of ceilings below 1,000 feet, ceilings
should descend into IFR range again between 06-10Z at
KBMI/KDEC/KSPI and continue into about mid morning. By midday,
ceilings should improve above 3,000 feet.
Geelhart
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
Area Forecast Discussion
National Weather Service North Platte NE
628 PM CST Tue Mar 5 2024
.KEY MESSAGES...
- Attention turns to the potential for a convectively enhanced
mesoscale snow event across either scntl or swrn Nebraska. The
GFS has been showing this feature across scntl Nebraska for
several runs while the ECM shows it across swrn Nebraska.
Either way, there is the potential for locally heavy snow
Thursday and Thursday night.
&&
.SHORT TERM /THROUGH THURSDAY/...
Issued at 339 PM CST Tue Mar 5 2024
Sfc low pressure across MT and the Pac NW will develop southeast
into wrn SD tonight. This will set up south winds and warm air
advection across wrn/ncntl Nebraska and the low temperature forecast
leans on the short term model blend for lows in the lower 30s;
similar to the previous forecast. Moisture will be on the increase
but there is a chance the very dry air in place will cause temps
to tank before midnight.
South winds and warm air advection will continue across most of the
region Wednesday but the model consensus shows a cold front dropping
into nwrn Nebraska during the afternoon. The temperature forecast
Wednesday is guarded by the short model blend plus the RAP model.
This forecast keeps highs in the 50s across far nw Nebraska. Highs
in the lower 60s are in place elsewhere. Our forecast is slightly
cooler than the NBM 50th percentile and a check on the RAP model
soundings indicates the south winds will limit vertical mixing
warranting the cooler forecast.
The cold front will sweep through wrn/ncntl Nebraska Wednesday
night. The short term model blend plus the HREF, CMreg and NAM12
models suggested a chance of rain changing to snow, mainly across
the wrn Sandhills. Given the caliber of the cold air, the NAMnest
suggested a period of light freezing rain. The dynamics for this
event are unclear as frontogenesis is weak. The forecast QPF is less
than 0.10 inches.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
Issued at 339 PM CST Tue Mar 5 2024
Attention turns to the potential for a convectively enhanced mesoscale
snow event across either scntl or swrn Nebraska. The GFS has
been showing this feature across scntl Nebraska for several runs
while the ECM shows it across swrn Nebraska. Either way, there
is the potential for locally heavy snow Thursday and Thursday
night. The focus in the GFS is a mid/low level inverted trof
while the ECM shows a stationary front along the KS border
across swrn Nebraska. The NAM and SREF are silent. The forecast
will wait on the RAP and HRRR models for clarification. The
location of the focus is uncertain, the dynamics will be weak,
but moisture will be plentiful. Our snow forecast leans toward
the SREF for 1 to 2 inches of snow across the Sandhills, swrn
and scntl Nebraska. WPC suggested a 30 percent chance of 4
inches or greater snowfall across a swath from Imperial to
Stapleton to Halsey.
It`s worth noting the cavalier nature of March and April weather
precludes discounting and any model solution completely. The storm
is off the California coast this afternoon will move ashore
Wednesday and then into the cntl Plains Thursday. The main dynamics
will track south of the Colo Rockies and this often favors KS/Colo
for the best QPF as suggested by the NAM.
Once this system clears the Great Plains Friday, the models are in
very good agreement building heights across the region and this
should lead to a warming trend Saturday through Tuesday.
Temperatures at h850-700mb warm to 12C and 0C, resp. Highs in the
50s and 60s are in place during this time which would seem to be
about right. Noteworthy, the NBM 50th suggests highs in the 50s, 60s
and 70s.
&&
.AVIATION /00Z TAFS THROUGH 00Z THURSDAY/...
Issued at 626 PM CST Tue Mar 5 2024
VFR conditions will prevail across all of western and north
central Nebraska through Wednesday. Southerly low-level wind
shear is a concern late tonight into Wednesday morning. Winds
will be gusty from the south on Wednesday. Winds shift to the
north in the afternoon across northern Nebraska.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SHORT TERM...CDC
LONG TERM...CDC
AVIATION...Taylor
Area Forecast Discussion...Updated Aviation
National Weather Service Saint Louis MO
551 PM CST Tue Mar 5 2024
.KEY MESSAGES...
-Temperatures are expected to be around 10 degrees above normal on
Wednesday and Thursday and around 20 degrees above normal on Friday
before falling to near normal over the weekend.
-Several rounds of rain and a few thunderstorms are expected
Thursday through Sunday with the chance over much of the area
of seeing at least 1" of rain from this rain exceeding 70%.
&&
.SHORT TERM... (Through Late Wednesday Night)
Issued at 305 PM CST Tue Mar 5 2024
Extensive cloud cover was found across the area this afternoon
behind the front as it was exiting the CWA. There were a few
showers and isolated thunderstorms over southeast Missouri that have
developed in an area of 1000 J/kg MUCAPE. The HRRR is showing that
there will be a small window for these showers and thunderstorms to
continue over southeast Missouri late this afternoon before exiting
to the southeast. Then dry weather is expected through Wednesday
evening as a low amplitude upper ridge and a surface high moves
across the Midwest. A chance of rain will return to parts of
central Missouri late on Wednesday night as a low level jet
increases beneath increasing ascent ahead of a mid-level trough.
We will see more some more sun tomorrow which will allow highs to
climb to around 10 degrees above normal given 850mb temperatures
will remain around 5C.
Britt
&&
.LONG TERM... (Thursday through Next Tuesday)
Issued at 305 PM CST Tue Mar 5 2024
We will be entering an active pattern late this week into the
weekend as there is reasonable agreement between the operational
models and their respective ensemble members. A series of shortwave
troughs will move across Missouri and Illinois in southwesterly flow
before a northern stream trough finally kicks the trough east of the
area on Saturday night. Before then, moisture will get drawn
northward from the Gulf of Mexico with PWATS around 1" which is
around the 90th percentile for this time of year. The most likely
time for rain will be late Thursday into Friday evening when a
surface low and a attendant front will be moving across the area.
There will also be the potential for a few strong storms during this
same time period as the warm sector will have MUCAPES in the 500-
1000 J/kg with deep layer shear around 40 knots, so some storm could
be capable of producing hail. In addition, ensemble guidance is
pointing toward a 70% chance of at least 1" of rain during this time
period with potential for 2 to 3" of rain in some spots. As
mentioned above, the rain will end as the trough moves off to the
east and subsidence sets in behind the trough. Dry weather is
expected through early next week as an upper ridge builds into the
Midwest.
Temperatures are expected to warm to around 20 degrees above normal
by Friday as the warm sector moves into the area. Temperatures will
fall back to normal over the weekend behind a cold front as 850mb
temperatures fall to just below 0C before highs climb back into the
60s early next week.
Britt
&&
.AVIATION... (For the 00z TAFs through 00z Wednesday Evening)
Issued at 550 PM CST Tue Mar 5 2024
Moisture at the back side of an exiting frontal boundary is
resulting in low stratus this evening. IFR seems to be winning
out, especially over metro terminals and westward through portion
of central Missouri. Elevation differences between KJEF and KCOU
may keep KJEF in MVFR tonight, but may need adjustment through
amendments if there are any signs of downward trends. The
northwest edge of the stratus deck extends from west-central
Missouri through southeast Iowa, where IFR improves to low end
MVFR and VFR further northwest. While IFR/MVFR will persist
overnight, improvement to MVFR/VFR is expected between late
morning and early afternoon Wednesday.
Maples
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...None.
IL...None.
&&
$$
WFO LSX
Area Forecast Discussion
National Weather Service Melbourne FL
900 PM EST Tue Mar 5 2024
.DISCUSSION...
...Couple Strong to Marginally Strong Storms Tonight and Again
Wednesday Afternoon...
Current-Overnight...ISOLD-SCT lightning storms developing over WCFL
this evening, the result of sea breeze collisions, will spread E/NE
into ECFL thru the evening. A couple storms could become strong to
marginally severe with primary impacts of cloud-to-ground lightning
strikes, gusty winds of 35 to 50 mph - 1 or 2 storms with gusts to
50-60 mph, small hail, locally heavy downpours, and an isolated
tornado cannot be ruled out due to favorable storm parameters.
However, latest guidance from the local HRRR is becoming less
optimistic with coverage and severe weather.
Greatest threat timing will be through around 2AM. Additional
convection over the GoMex associated with a MCS will move onto the
Gulf Coast later this evening and push steadily eastward across the
area overnight. Models do suggest a weakening trend with this
convection as it pushes across southern sections overnight. Much of
this activity should move off of the Treasure Coast by around 3-4
am. Overnight lows mild and in the 60s. Generally cloudy conditions.
Wed...Previous...With passage of the upper trough axis early in the
morning, there is some uncertainty on convective redevelopment
during the day esp across the north. Have drawn 40-50 PoPs Orlando
northward but this may be generous. A better chance for storms to
redevelop will occur over southern sections (60-70 percent PoPs).
Given slightly cooler temps aloft (-12C to -13C), a stronger upper
jet and sfc heating, any storms may become strong to marginally
severe with wind gusts and hail. The more unidirectional (SW) flow
through a deep layer will limit threat for tornadoes. The one caveat
is if a sea breeze can form along the immediate Treasure coast which
would locally enhance the low level shear. Highs in the U70s to L80s.
&&
.MARINE...Overnight-Wed...Southeast winds becoming southerly
overnight and SSW/SW into Wed ahead of approaching front. Wind
speeds 8-13 kts will increase 15-20 kts offshore thru Wed morning,
then relax a bit in the afternoon. Seas 3-4 ft near shore building
to 4-6 ft by daybreak Wed morning offshore all in an ENE swell.
Cautionary Statements necessary offshore (20-60nm). Increasing
threat overnight for SCT showers and lightning storms. Some storms
could become strong to marginally severe as they push off of the
coast. Primary storm threats include cloud-to-water lightning
strikes, gusty winds 35-45kts - 1 or 2 could approach 50 kts,
torrential downpours, and cannot rule out a waterspout. Additional
strong storms could form Wed afternoon and move off of the coast,
esp south Sebastian Inlet.
&&
.AVIATION...Unsettled weather developing over W FL and the GoMex
will push across the peninsula this evening and overnight. SCT
showers and lightning storms, a couple possibly strong to severe,
will spread E/NE across LEE/MCO/SFB/DAB btwn 01Z-07Z and
MLB/VRB/FPR/SUA btwn 04Z-09Z. ESE-SE winds will become southerly
overnight and SW to W on Wed ahead of an approaching front. Speeds a
little higher Wed 12-15 knots with some higher gusts. Remain less
confidence on rain/storm chances on Wed across northern terminals.
Will continue to handle with "VC" wording for now. Higher coverage
expected over southern terminals. Gusty winds 35 kts or greater may
accompany some of the storms.
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...None.
AM...None.
&&
$$
Sedlock/Heil
Area Forecast Discussion
National Weather Service Morristown TN
935 PM EST Tue Mar 5 2024
...New UPDATE...
.UPDATE...
Issued at 931 PM EST Tue Mar 5 2024
A few minor updates to the forecast this evening. Northeast TN and
southwest VA running quite a bit warmer than forecast. Raised
overnight lows by several degrees across these areas. Also, made
some POP adjustments based on latest radar trends and HRRR runs.
Tried to decrease POPS west of I-75 for the next few hours before
ramping things back up after midnight as the next wave spreads in
from the southwest. Still no flooding concerns at the moment but
will continue to keep an eye things as the night progresses. Main
area of focus will be across the southern TN valley east of I-75,
toward Cherokee and Clay NC.
&&
.SHORT TERM...
(This evening through Wednesday)
Issued at 327 PM EST Tue Mar 5 2024
Key Messages:
1. Showers and perhaps a few rumbles of thunder will continue
pushing northeastward across the forecast area this evening and
through the night.
2. Precipitation chances decrease into the day Wednesday.
Discussion:
An east northeast moving shortwave trough and corresponding weak
surface low will move just south of the area towards the coast by
late Wednesday. A stationary front drapes across the country to
our west. Due to the location and movement of the low, easterly to
southeasterly winds will cross perpendicular to the mountains,
which may delay onset of precipitation in the foothills. Low-level
flow peaks late tonight between 25 and 35KT. Locations prone to
high wind gusts, such as Cove Mountain, aren`t expected to exceed
40 mph, so there`s no concern for any sort of wind advisory. So, gusts
near 30 mph can be expected for higher elevation spots in the
Appalachians.
Precipitation amounts will be greatest across the southern CWA and
over mountain peaks around the GSMNP and southward. Chattanooga
for example, could see rainfall amounts over one and a half
inches by Wednesday evening. Along a line from Morgan County,
Knox, to Greene County may see around an inch or so of rainfall.
Northeast TN and southwest Virginia will amount to around three
quarters of an inch to nine tenths of an inch. Possible local
heavy rainfall across southeast Tennessee and extreme southwest
North Carolina, could lead to localized flooding.
Tomorrow, temperatures cooler as rain moves out with time into
Wednesday and cloud cover lingers. Rain chances decrease late
tomorrow morning into the evening. Winds across the mountains will
subside as the direction changes out of the north following the
lows passage.
&&
.LONG TERM...
(Wednesday night through next Tuesday)
Issued at 327 PM EST Tue Mar 5 2024
Key Messages:
1. Warm and dry on Thursday, but another system makes its way into
the area for Friday through Saturday bringing additional rainfall.
2. Turning colder to start the new week.
Discussion:
Western trough at 500 MB will open and push eastward, drawing Gulf
and tropical Pacific moisture into our area by Friday. Models
continue to suggest that two precip bullseyes will occur Saturday,
one to our south over GA, and one to our NW over the Ohio Valley.
Precip accumulations in our area will favor the heaviest to occur
over our southern areas, with another 1.5 inches on average. But we
can hold out hope that maybe those amounts will contract more toward
the GA bullseye, as the ground will be wet thanks to tonight-
Wednesday`s rain. A double punch of at least 1.5 inches, first on
Wednesday and then on Saturday, would make the Saturday event more
primed for flooding. Will continue to monitor developments.
Colder air moves in behind the departing late-week rain event, with
lows near freezing in the Valley for Mon and Tues mornings, but dry.
&&
.AVIATION...
(00Z TAFS)
Issued at 641 PM EST Tue Mar 5 2024
Unsettled weather will gradually build north into the overnight
hours, with predominant MVFR or lower flight conditions slowly
settling in at all three sites. By early Wednesday morning expect
IFR ceilings to settle in across the area. MVFR to IFR visibility
will be possible during periods of the strongest showers. CHA
would have the greatest chances to observe relief with low VFR
cigs by late Wednesday but have opted to hold MVFR clouds through
the period at this time. Wrap around moisture as the surface low
shifts eastward will keep precipitation lingering into the latter
half of the TAF cycle at TYS and TRI.
&&
.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN 56 69 50 71 / 100 80 0 0
Knoxville McGhee Tyson Airport, TN 54 61 50 67 / 100 90 10 0
Oak Ridge, TN 54 64 50 69 / 100 90 10 0
Tri Cities Airport, TN 55 59 48 65 / 90 90 30 0
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&
$$
SHORT TERM...
LONG TERM....GC
AVIATION...KRS
Area Forecast Discussion
National Weather Service Raleigh NC
745 PM EST Tue Mar 5 2024
.SYNOPSIS...
High pressure will linger over the Carolinas ahead of a low pressure
system that will move across the Southeast tonight and across and
offshore the Carolinas and Middle Atlantic Wednesday and Wednesday
night.
&&
.NEAR TERM /THROUGH TONIGHT/...
As of 745 PM Tuesday...
No significant changes to this evenings forecast update. Low clouds
are still lingering over the coastal regions and with that low level
moisture sticking around fog and low status is expected to develop
across NW portions of NC overnight. Some areas could experience
dense fog early Wednesday morning. A surface low centered over MS/AL
will continue to trek east-north-east overnight before moving over
NC and interacting with a retreating trough/frontal boundary early
Wednesday. Chances of precipitation will increase slowly overnight
from the west and the east before closing in with precip chances
area wide before sunrise. Lows overnight will be in the low 50s
north, to mid 50s south.
As of 325 PM Tuesday... A southern stream shortwave trough over the
lower MS Valley, consisting of multiple embedded disturbances, will
eject NE into the SE US and southern Appalachians overnight. Weak
cyclogenesis is forecast to ensue over the SE US this evening and
tonight, with a retrogression and sharpening of a warm front
occurring along the SE coast during the same time.
Clouds will steadily increase from the SW during the evening and
overnight hours. Additionally, as the low-level flow backs to NELY
with the sharpening of the coastal warm front front, it`s looking
increasingly likely that a layer of maritime stratus and/or fog will
advect inland into the central-northern coastal plain, and quite
possibly spilling west into the eastern Piedmont counties.
Otherwise, rain will begin to set in from the SW between 09 to 12z,
with the heavier rain elements confined to southern portions of the
forecast during this time period. Lows tonight in the lower to mid
50s, with the exception for some upper 40s across the northern
Piedmont counties.
&&
.SHORT TERM /WEDNESDAY AND WEDNESDAY NIGHT/...
As of 315 PM Tuesday...
Aloft, a s/w will lift NE from the Southeast US and through the
Carolinas Wed/Wed night. At the surface, a westward drifting
inverted trough will stall along/just inland of the Carolina coast
early Wed as a low moves through the Carolinas. For being less than
24 hours out, there is still some disagreement between the models
wrt where and when this low will track, with the NAM being the
primary outlier. The general consensus is for the low to swing
around the southern Appalachians and eastward through norther GA and
SC through early aft, then continue newd inland of the SC/NC coasts
through Wed eve/night. The best instability and shear will be invof
the low as it tracks northeast, but exactly how far west that track
will be remains somewhat uncertain. For now, the best chance for
showers/storms will be along and east of I-95, roughly Fayetteville
to Rocky Mount and points southeast. Otherwise, precipitation should
largely remain stratiform. With a low track along I-95, the 12Z HRRR
forecast soundings for Wed late aft/early eve are showing a period
of SBCAPE up to 500 J/Kg with 1-Km shear around 20 kts at KFAY and
roughly 300 J/Kg and 30 kts at RWI. Should the track be farther
east, that would decrease chances for storms for central NC, but a
farther west track would increase chances. Eastern NC is still in
general thunder from the SPC for Wed. Regardless of the thunder
potential, rainfall amounts should generally range from half an inch
to an inch across central NC through Wed night, with most of that
expected to fall between sunrise and sunset Wed. Following a brief
lull in precipitation as the surface low moves away, another round
of rain is possible Wed night associated with the s/w aloft as it
lifts through the Carolinas. Temperatures will depend to some degree
on the track of the low and the inland extent of the coastal warm
front, but for now expect highs around 60 degrees NW to around 70
degrees SE. Lows ranging from upper 40s NW to mid 50s SE are
expected.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
As of 310 PM Tuesday...
Although it is not a model consensus, the 12Z GEFS, 12Z ECMWF, and
15Z SREF all show rain lingering across northeastern counties
Thursday morning, and have added pops from Raleigh to the northeast
through mid-morning. High pressure will be centered over Quebec
Thursday, with a ridge briefly extending south into the Carolinas.
The ridging will be short lived as low pressure developing over the
central Plains moves northeast into the Great Lakes. Similar to the
midnight shift, the trend has been to further slow the arrival of
precipitation on Friday, only going with slight chance pops west of
the Triangle, and continuing into Friday night. The bulk of the rain
still appears likely to occur on Saturday. With limited instability
shown, have trimmed back the mention of thunderstorms to southern
counties, although there still remains a bit of uncertainty with
this in models. This appears to be another system where about an
inch of rain can be expected in all locations, and considering how
strong the moisture transport will be into the region, higher
amounts of rainfall could easily be seen in locations with
convection. An isolated shower could linger Sunday morning northeast
of the Triangle, but the rest of the 7 day forecast should be dry
with high pressure dominating the southeastern United States.
After highs around 70 on Thursday, highs will fall a few degrees on
Friday, then back near seasonal values Saturday through Monday
before rising into the 60s everywhere on Tuesday. Lows will be in
the 40s Thursday and Friday nights, then into the 30s Sunday and
Monday nights.
&&
.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
As of 700 PM Tuesday...
Fog and low stratus will likely redevelop tonight in areas where IFR-
MVFR ceilings and rain occurred and lingered longest during the past
24 hours (ie. the NC nrn Coastal Plain and ne Piedmont, including at
RWI, and perhaps for a shorter duration at Piedmont sites). A shield
of stratiform rain, moderate to heavy at times, and top-down
moistening and lowering of ceilings to IFR, will otherwise
overspread cntl NC from the southwest on Wednesday.
Outlook: Sub-VFR restrictions and areas of drizzle and light rain
may linger through Wednesday night, followed by a chance of MVFR
ceilings with daytime heating Thu morning through early afternoon.
Widespread rain and flight restrictions will result with the passage
of a frontal system on Sat.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SYNOPSIS...MWS
NEAR TERM...CA/CBL
SHORT TERM...KC
LONG TERM...Green
AVIATION...MWS