Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 05/27/24
Area Forecast Discussion
National Weather Service Binghamton NY
1033 PM EDT Sun May 26 2024
.SYNOPSIS...
Our next system moves in late tonight into Monday with locally
heavy rain and a chance for thunderstorms. A few storms may
become severe Monday afternoon. Additional scattered showers
will linger through midweek, with drier conditions expected
towards the end of the week.
&&
.NEAR TERM /THROUGH MONDAY NIGHT/...
1030 PM Update...
Updated the timing of the PoPs by incorporating some of the
latest 00z HRRR and 3km NAM; otherwise the forecast remains on
track. The line of strong to severe storms over western PA looks
to dive south and weaken to just rain with a few embedded
rumbles of thunder possible for our CWA overnight.
630 PM Update...
Only minor adjustments to the near term forecast with this
update. Chances were decreased to just low end slight chance for
an isolated t`storm over Sullivan and Pike Counties this
evening. Otherwise, timing was tweaked for the arrival of
showers and t`storms late tonight into Monday. Much of the
morning hours could end up mainly dry on Monday, before showers
and storms quickly develop midday, becoming more widespread in
the afternoon and early evening.
254 PM Update...
Still a fair bit of fair wx cumulus across the area, but expect
cloud cover to continue to diminish for the remainder of the
afternoon. High clouds will begin to increase from SW to NE this
evening, which along with increasing SE winds, should keep valley
fog from developing overnight. There`s still a chance for an odd
shower or thunderstorm to pop up in the Catskills and/or Poconos
this evening, but coverage will be limited.
A shortwave trough, currently bringing thunderstorms to the Ohio
Valley, will move northeast tonight, lifting a warm front northwards
and bringing a band of showers and isolated thunderstorms across
the area after midnight. Additional rounds of showers will be
possible in a fairly messy warm sector during the morning and early
afternoon hours as additional upper level shortwave troughs move
through, and the broader area ends up under the right entrance
region of a 90 knot jet streak.
The "messiness" of the warm sector will be important later in the
afternoon as it will directly impact the amount of destabilization
that can occur ahead of the main shortwave and prefrontal surface
trough. By early afternoon, bulk layer shear will be around 35
knots, but more critically, 0-1km shear values will be 30-40 knots
across parts of NEPA and into the Catskills. This implies an all-too-
familiar local forecast dilemma of limited instability and high low
level shear which can lead to a tornado or two from a relatively low-
topped and grungy thunderstorm. SPC has put parts of NEPA into the
5% Tornado Risk in the Day 2 Convective Outlook, and has increased
the risk of severe thunderstorms to Slight Risk across all of our PA
counties, with Marginal for the balance of the region.
Destabilization will be key, and this given the shear values, the
greater risk could spread a little further east into the
Catskills, but much depends on how rainfall and cloud cover
holds in during the day tomorrow.
Localized heavy rainfall is also possible, but the risk of flooding
will be mitigated by a fairly progressive storm motion and forcing.
PW values still are on the high side, and spot flooding could still
occur in one or two areas where training of cells occurs. The most
likely area would be near and south/southeast of the I-88 corridor,
but the overall risk is too low for a flood watch at this time.
The heavy rain threat will push east of the area during the evening
hours.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
330 PM Update...
A long wave trough sitting over the NE US will be the main
weather driver for the period, bringing cooler temperatures and
rain showers.
On Tuesday, a shortwave trough will push through the region with
an associated surface low north of the area over Canada. Diurnal
heating combined with the lift from the shortwave will bring a
chance for afternoon rain showers and isolated thunderstorms.
With the weak forcing, lack of deep moisture, and cool
temperatures, severe weather is not expected at this time. Flow
during the day progressively shifts westerly, bringing a cooler
airmass overhead. Temps will climb into the upper 60s to low
70s across much of the region, with some of the warmer valleys
climbing into the mid 70s.
Tuesday night should be dry for most as the trough exits the
region to the ENE. Temperatures will fall into the upper 40s to
low 50s thanks to cool WNW flow. Conditions will not stay quiet
for long as another trough, this time positively tilted, moves
into the region from the NW. This will continue to push cooler
air into the region, with temps on Wednesday only climbing into
the low to mid 60s for most, and upper 60s to low 70s in NEPA.
There is still some uncertainty in the latest guidance as to
how the trough will unfold, with some showing most of the rain
missing us to the south, while others have light scattered rain
showers across the area. Given this synoptic pattern, severe
weather is not expected. The trough swings through the area by
the evening, ushering in much drier air and colder from Canada.
Temps Wednesday night will fall into the low to mid 40s.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
345 PM Update...
A positively tilted upper level trough remains overhead
Thursday into Friday, continuing NW flow and cooler
temperatures for the end of the work week. Suppression from a
surface high building into the region combined with a lack of
moisture in the atmosphere will keep conditions dry. Temps will
be in the 60s for highs and 40s for lows. A strong ridge builds
into the area on Friday night, making for quite a lovely
weekend. Temps will slowly warm as the ridge slides east,
bringing seasonable temperatures for the weekend.
&&
.AVIATION /03Z MONDAY THROUGH FRIDAY/...
VFR conditions will continue this evening with high and mid
clouds increasing tonight, followed by lower clouds as showers
return to the area after about 09Z. A few embedded thunderstorms
are possible as precip returns, but fairly low probability at
any given point. Shower coverage will likely diminish Monday
morning, only to return again towards midday or early afternoon,
with heavier downpours and thunder becoming increasingly likely.
Guidance hints at a short window of IFR ceilings at BGM/AVP as
showers move through, otherwise MVFR to Fuel Alt conditions are
expected at the remaining sites until the end of the period.
Outlook...
Monday afternoon and night...Restrictions likely with locally
heavy rain showers and thunderstorms expected.
Tuesday through Wednesday...Occasional restrictions likely from
multiple batches of showers and thunderstorms.
Thursday and Friday...Mainly VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...None.
NY...None.
&&
$$
SYNOPSIS...MJM/MPH
NEAR TERM...MJM/MPH
SHORT TERM...JTC
LONG TERM...JTC
AVIATION...ES/MPH
Area Forecast Discussion
National Weather Service Boston/Norton MA
1110 PM EDT Sun May 26 2024
.SYNOPSIS...
Downpours and thunderstorms persist through early evening.
Widespread shower activity tomorrow ahead of approaching cold
front that will bring renewed heavy rain and thunder chances to
SNE. Cold front moves offshore early on Tuesday, with decreasing
clouds and drier weather conditions. A cooler more seasonable
air mass then builds into Southern New England for the remainder
of the workweek into much of the weekend. Mainly dry weather
prevails as well, though there is a chance for rains on
Wednesday night.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
Convection had finally moved into northern New England late
this evening, taking it away from from the most favorable
environment per latest SPC mesoanalysis. Expecting a bit of a
relatively quiet period for a few hours.
The last several runs of the HRRR have been quite aggressive in
redeveloping convection after midnight into Monday morning.
However, it seems to be alone with that outcome. Stratus has
overspread that portion of the coastal waters and extended north
across RI and much of southeast MA. Having a hard time accepting
that outcome, but will be wary for the possibility overnight.
Maintained a mainly dry forecast until just before daybreak,
which is when a slow-moving front gets closer to our region.
Patchy fog is also expected, but without the widespread
visibility reduction to less than 1/4 mile, have held off on a
Dense Fog Advisory at this time.
710 PM Update:
Widely scattered and slow-moving heavy showers extend along a
narrow axis of surface wind convergence from roughly Marlborough
to near Amherst to Worthington MA in a regime of weak to
moderate instability (about 500-1500 J/kg of surface-based
parcel CAPE). We haven`t seen any lightning occur in any of
these heavier showers, and seems that shortwave ridging aloft
may be stunting deeper growth as radar all-tilts trends show
storm tops to around 25,000 ft but no higher. Nearing sundown,
waning instability, stabilizing PBL and the rain-cooling effect
over and in vicinity of these heavier showers as they rain
themselves out should cause activity to diminish by 9 PM if not
sooner.
Meanwhile to the south, starting to see the maritime airmass
advance northward, with layer of stratus expanding into eastern
CT, much of central and southern RI and most of southeast MA per
visible imagery. Expect stratus and areas of fog to develop and
expand north and west through the evening and overnight,
expected to take place as soon as temperatures cool off into the
low-mid 60s. It`s still a bit debatable if we`ll see fog -
BUFKIT hydrolapse profiles seem to indicate stratus as being
more favored than fog - but did include that in the forecast as
winds should go light. Removed mention of PoP for the
evening/overnight, think even drizzle could be hard to come by
as moisture layer is very shallow.
Previous discussion:
Downpours have begun to fire along the seabreeze boundary across
the far southern Hudson River Valley with a few rain showers
cropping up along the same boundary across northern CT and
central RI. Fortunately, storms are forming quickly but
transitioning to "orphan anvils" within a few scans, suggesting
our forecast of mainly sub severe storms is on track.
While storms remain innocuous as of this writing (at 19Z), do
continue to anticipate some slow moving strong storms to develop
along the I-90 corridor and perhaps south into northern Bristol
and Plymouth counties. 12Z CAMs continued to show initiation
"prime time" around 21Z with storms persisting through 00-01Z
this evening before subsiding quickly after sunset as
instability wanes. As for instability, models continue to
support 1500 J/kg SBCAPE combined with decent low and mid level
lapse rates of 7.5-8C/km and 6.5-7C/km respectively. Bulk
shear, while lackluster, will increase to between 30-40kt along
the MA/NH border later today, which will likely keep storms on
life support this evening.
Pockets of heavy rain continue to be the greatest threat
associated with storms this afternoon with PWATs around 1.25"
and weak flow aloft to keep storms moving. In general, many
communities will remain dry, but those under a potent cell could
see upwards of 1 to even 2" of rain, which may lead to some poor
drainage flooding especially if storms set up in the Boston
metro.
As mentioned, storms wane quickly after sunset but with easterly
flow, marine stratus and fog will expand from the nearshore
waters to at least the coastal plain. Places like the Cape and
Islands can expect to see dense fog, comparative in coverage to
last night. Prevailing wind direction should support more
expansive fog coverage overnight that may overspread inland to
the I-95 corridor.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
Low pressure over the Great Lakes continues east-northeast into
Ontario and Quebec as mid level trough digs into the Ohio River
Valley and mid-Atlantic. Warm front lifts from the mid-Atlantic
towards New England tomorrow but will fail to lift of ~central
NJ by mid day tomorrow. While we remain north of the warm
sector, will still have some prefrontal showers beginning as
early as 12Z across the western portions of the CWA before
tracking east through early afternoon with rain holding off in
places like Boston and Providence through around 15/16Z. Cold
front will fuel more potent line of rain after 20Z, with the 12Z
guidance speeding up the front`s arrival and departure by
several hours compared to last evening`s guidance; in fact, had
to stray significantly from the NBM given it`s know lag time to
derive PoPs through early Tuesday morning.
The greatest concern with tomorrow`s forecast will be the threat
for additional heavy rainfall, with PWATs climbing to near 2"
by late tomorrow afternoon and a decent southerly oriented LLJ
of between 30-40kt. Could certainly see some upslope enhancement
across the Berkshires and Worcester Hills, but fortunately the
jet lacks an easterly component that would really "ring out the
rain". HREF PMM and 24 hour MAX QPF ending early Tuesday morning
depicts local max QPF of 1.5-2" across the aforementioned
terrain features, with lesser amounts elsewhere. Warm cloud
depths near 12,000ft combined with very high PWATs should draw
one`s attention to the potential for tropical-like downpours
tomorrow afternoon, but the progressive nature of the front
should limit any flooding concerns to just poor drainage areas,
which is corroborated by WPC placing the entirety of the region
under just a "marginal" excessive rainfall outlook. Given a lack
of evidence pointing to widespread urban or flash flooding, did
not consider a flood watch with this package issuance.
Convective elements will likely be present, particularly along
the cold front, with tomorrow`s rain with modest instability
of 200- 600J/kg CAPE. With that said, convection looks to be
elevated, with really poor low level lapse rates below 5C/km.
Hodographs look quite curly tomorrow, but with no surface based
convection, the severe weather potential remains low. The one
saving grace for more prolonged convective showers would exist
due to bulk shear values approaching 50kt late tomorrow evening,
which may result in some locally gusty winds.
As previously mentioned, cold front should be east of the area
between 06-09Z Tuesday, which will lead to rapidly improving
conditions by sunrise Tuesday. Winds will shift from the E to
the south behind the front, which combined with residual
moisture, may drive another night of coastal fog.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
Highlights:
* Cold front moves offshore on Tue with decreasing rain chances
by later Tue AM and temps warming into the 70s to low 80s.
* Temps cool off to more seasonable levels starting Wed into the
weekend.
* Other than a chance for rain on Wed night into Thurs, much of
the rest of the workweek into the early weekend are generally
dry.
Details:
Cold front from Monday will continue to move offshore during the
morning hrs of Tuesday. There might still be some steadier rain
during the morning commute in eastern and southeast New England
but improving conditions are expected by later-morning, with
decreasing clouds allowing for temps to warm into the 70s to low
80s, with upper 60s/near 70 for the Cape and Islands.
A deep longwave trough becomes established over the Northeast
states as we move through the rest of the workweek into the
early part of next weekend. This trough will bring cooler than
normal 925-850 mb temps to Southern New England, bringing temps
closer to late- May/early-June climatological values (upper 60s
to lower to mid 70s). Though it is a generally dry weather
regime, we do have to watch around Wed night into Thurs for
chances for showers as an embedded shortwave disturbance aloft
rotates around the trough. There are differing answers as far as
the placement and track of this shortwave trough, with the ECMWF
the most bullish on bringing steadier rains to SNE for Wed night
into Thurs, with the GFS interestingly being dry while the
Canadian GEM too far south for any significant precip. NBM
guidance was showing 25-40% PoP for rains and opted to stay
close to that until there`s better agreement on the shortwave
trough. Other than the Wed night into Thurs timeframe, overall
it looks to be a decent stretch of weather. Our next chance of
rain may not arrive until very late Sunday or into next Mon.
&&
.AVIATION /03Z MONDAY THROUGH FRIDAY/...
Forecast Confidence Levels:
Low - less than 30 percent.
Moderate - 30 to 60 percent.
High - greater than 60 percent.
Tonight: High confidence in trends, though moderate on timing.
IFR to VLIFR fog and stratus expands north and west as the
evening/overnight progresses. IFR to VLIFT across RI and SE MA
through 12Z. IFR across northern CT into the CT River valley.
Light E to SE winds.
Tomorrow... High Confidence in Trends
IFR/LIFR for most. Scattered showers develop between 12-16Z.
Lull in shower activity expected from 16-19Z or so from west to
east. More robust line of rain associated with a cold front
develops after 19Z. Some embedded Thunder possible with the
second round of rain. Winds remain from the east, may gust as
high as 20kt tomorrow afternoon.
Tomorrow night... Moderate Confidence in timing
Rain will come to an end between ~03-06Z yielding improving
conditions with improvement from IFR to VFR around sunrise.
Winds shift from the E to the S, gusting to 20kt, behind frontal
passage.
KBOS TAF...High confidence in TAF trends, moderate in timing.
VFR initially, though IFR to LIFR stratus develops around 03z
and continues at least through the early afternoon. Guarded
optimism for one- category improvement in the early afternoon
but this isn`t certain; however rain then arrives later in the
day and especially Mon evening. Light E winds become SE 4-8 kt
tomorrow.
KBDL TAF...High confidence in TAF trends, moderate in timing.
VFR initially, though IFR-LIFR stratus develops around 03z and
continues at least thru early afternoon. Could see one-category
improvement to IFR-MVFR range but as that occurs, increasing
chances for steady rain. S winds tonight becoming SE and
increasing to around 10 kt.
Outlook /Tuesday through Friday/...
Tuesday: Mainly VFR, with local IFR possible. Breezy. Slight
chance SHRA.
Tuesday Night: VFR.
Wednesday through Thursday: VFR. Chance SHRA.
Thursday Night through Friday: VFR.
&&
.MARINE...
Forecaster Confidence Levels:
Low - less than 30 percent.
Medium - 30 to 60 percent.
High - greater than 60 percent.
Through Memorial Day... Moderate Confidence in fog.
Another night of dense marine fog expected as winds prevail from
the east. Increased shower activity early Monday before a cold
front brings the chance for more potent rain and embedded
thunder to the waters late tomorrow evening and early Tuesday
morning. Winds increase, gusting between 25-30kt from the east
before turning south behind the front. Waves climb in excess of
5 feet across the outer waters. SCA has been hoisted for the
eastern outer, and southern waters, including Nantucket sound
late tomorrow/tomorrow night.
Outlook /Tuesday through Friday/...
Tuesday: Winds less than 25 kt. Seas up to 5 ft. Chance of rain
showers, patchy fog.
Tuesday Night through Wednesday: Winds less than 25 kt. Seas up
to 5 ft.
Wednesday Night: Winds less than 25 kt. Areas of seas
approaching 5 ft. Chance of rain showers.
Thursday: Winds less than 25 kt. Seas locally approaching 5 ft.
Slight chance of rain showers.
Thursday Night: Winds less than 25 kt. Seas locally approaching
5 ft.
Friday: Winds less than 25 kt.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...None.
RI...None.
MARINE...Small Craft Advisory from 9 PM Monday to 11 AM EDT Tuesday for
ANZ232-233-235-237.
Small Craft Advisory from 6 PM Monday to 5 AM EDT Wednesday
for ANZ250-254.
Small Craft Advisory from 9 PM Monday to 5 AM EDT Wednesday
for ANZ255-256.
&&
$$
SYNOPSIS...Loconto/KS
NEAR TERM...Belk/Loconto/KS
SHORT TERM...Belk/KS
LONG TERM...Loconto
AVIATION...Belk/Loconto/KS
MARINE...Loconto/KS
Area Forecast Discussion
National Weather Service Burlington VT
937 PM EDT Sun May 26 2024
.SYNOPSIS...
A storm system moves through tomorrow and tomorrow night, bringing
rounds of rain, gusty winds, and a couple embedded thunderstorms.
There is a low risk of severe storms over northern New York. The
steady rain moves out Monday night but there will be a few chances
for showers mid and late week. Temperatures will generally be close
to seasonable.
&&
.NEAR TERM /THROUGH TUESDAY/...
As of 930 PM EDT Sunday...A quick update to expand 20-30% pops
across southern/eastern VT from roughly 02z-07z, as radar is
showing some showers and thunderstorms developing over southern
NH/VT. These showers with some lightning/rumbles will continue
to move northward toward our region over the next couple
hours. Rest of fcst in good shape.
Monday continues to look active, with the potential for a few
strong to locally severe storms across the St Lawrence Valley
and Western Dacks region if clearing/instability can develop.
Latest 00z HRRR indicates temps warming into the upper 70s to
near 80F, which combined with dwpts in the mid 60s, creates CAPE
values near 1000 J/kg, enough given the wind profiles to
support some localized strong/svr storms. Low level wind fields
are very strong, so won`t need much to mix stronger winds to the
sfc and given the turning profiles and large cyclonic
hodographs, rotating storms are possible and will need to be
watched closely.
Previous discussion below. Skies are
currently mostly clear with only some daytime cumulus present
over the higher elevations. The cumulus will dissipate this
evening but clouds will quickly move in from the west out ahead
of a relatively strong storm system. There will be periods of
rain during the day on Monday and chances for a few embedded
thunderstorms, particularly over northern New York. Instability
will be low but there will be strong 0-6KM and low-level shear
so there is a low chance of severe thunderstorms, mostly over
the parts of St. Lawrence Valley. That is the area with the
strongest instability. A low-level jet will pass overhead during
the day Monday, bringing winds up to around 50KTs at 925 mb.
There will be some breaks in the rain when the strongest part of
the jet will be overhead, so there is the opportunity for some
of the stronger winds to mix to the surface. The wind direction
will generally be SSE so this favors areas over the northern
Adirondacks seeing the strongest winds, where gusts above 40 mph
are possible. Steadier rain arrives and the low-level jet exits
in the evening, so winds will calm down a bit. The cold front
will move through Monday night and will bring the heaviest
precipitation. Overall, rainfall amounts look to range from
around a third of an inch over northern areas to around an inch
over southern areas. Areas that receive heavier convective
showers will see locally more. There is a low risk of flash
flooding where the strongest convective storms set up.
Therefore, the whole region is in a marginal excessive rainfall
outlook for a 5% chance of flash flooding. Behind the front
Monday night, there should be a break in the rain, but
temperatures will stay relatively mild. Lows should be in the
mid 50s to lower 60s.
&&
.SHORT TERM /TUESDAY NIGHT/...
As of 355 PM EDT Sunday...Troughiness will remain over our area for
Tuesday and Tuesday night as upper level trough lags behind surface
boundary which will push east of Vermont early Tuesday morning.
There will be a break in the precipitation chances Tuesday morning,
then increasing pops as we head into the afternoon hours with
vorticity swinging overhead. Showers will continue into the
overnight. Have a slight chance of thunder Tuesday afternoon in the
St Lawrence valley, then we lose surface based instability
overnight. Highs on Tuesday will range from the upper 60s in
Northern New York to upper 70s across the larger valleys in Vermont.
Overnight temperatures will range from the mid 40s to mid 50s,
coldest in the Adirondacks.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
As of 355 PM EDT Sunday...Expect another showery day on Wednesday as
upper trough still remains over the region. Some drier air will
finally work into the area behind departing upper trough on
Thursday. Thursday continues to look like the coolest day of the
period with highs only reaching the upper 50s to lower 60s, with
breezy northwesterly flow. Models are depicting building ridge
towards the end of the week with an overall drying trend
anticipated. Temperatures will trend back towards seasonal normals
headed into the weekend.
&&
.AVIATION /02Z MONDAY THROUGH FRIDAY/...
Through 00Z Tuesday...VFR conditions are expected to prevail
across all terminals for the next several hours ahead of an
approaching storm system. Ceilings will begin to lower
overnight as southerly winds bring increased moisture, with MVFR
ceilings possible at KMPV by 09Z or so and more widespread MVFR
ceilings expected by the afternoon. Precipitation will gradually
overspread the region during the day, with some MVFR, and some
localized IFR, conditions possible in the heaviest showers and
some thunderstorms will also be possible across northern New
York terminals (KMSS and KSLK).Winds will remain fairly light,
generally 10 knots or less, before a strong low- level jet
brings strong southeasterly winds for most of the forecast
period with gusts up to 25 knots possible. LLWS is expected to
develop across all terminals during the morning into the early
afternoon.
Outlook...
Monday Night: Mainly VFR, with local IFR possible. Definite SHRA,
Slight chance TSRA.
Tuesday: Mainly VFR, with local MVFR possible. Slight chance
SHRA.
Tuesday Night: Mainly VFR, with areas MVFR possible. Chance SHRA.
Wednesday: Mainly MVFR, with areas VFR possible. Chance SHRA.
Wednesday Night: Mainly VFR, with local MVFR possible. Chance
SHRA.
Thursday: VFR. Slight chance SHRA.
Thursday Night: VFR. Slight chance SHRA.
Friday: VFR. Slight chance SHRA.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...None.
NY...None.
&&
$$
SYNOPSIS...Myskowski
NEAR TERM...Myskowski/Taber
SHORT TERM...Neiles
LONG TERM...Neiles
AVIATION...Kremer
Area Forecast Discussion
National Weather Service Columbia SC
1047 PM EDT Sun May 26 2024
.SYNOPSIS...
A cold front will move through the area late Monday. Scattered
strong thunderstorms are expected ahead of the front with
temperatures remaining above normal. More seasonable
temperatures and drier conditions are expected behind the front
through mid to late week as a high pressure area builds in from
the upper Mississippi Valley.
&&
.NEAR TERM /UNTIL 7 AM MONDAY MORNING/...
The radar is much quieter at this hour with a singular thundershower
moving into Newberry County. The majority of the overnight
period is expected to be tranquil until the next MCS approaches
the forecast area from the northwest towards daybreak with a
slight chance of a few passing showers over the far northwestern
CWA. The evolution of this feature will dictate how the
potential severe weather plays out on Monday and will need to be
monitored as it approaches. Skies have cleared out over the
CSRA and this clearing trend will continue from southwest to
northeast during the next several hours. However, cloudiness
associated with the aforementioned MCS will increase towards
daybreak. It`ll be a muggy night with temperatures falling into
the lower 70s by daybreak.
&&
.SHORT TERM /7 AM MONDAY MORNING THROUGH TUESDAY NIGHT/...
The active weather pattern will continue Monday into Monday
night as low pressure tracks through the central Great Lakes and
pushes a cold front through the SE US. Although there is high
confidence the front will be moving through the region
confidence is currently low as to storm development and
coverage with much surrounding the convection and movement of
the MCS tonight. The MCS is expected to be moving toward Upstate
SC tonight however models continue to weaken the remains as it
crosses the mountains. Model soundings indicate some CIN in the
area Monday morning along with low level lapse rates under 5.5
C/Km and 850 mb winds turning more westerly. Even though
thunderstorms may not form in the morning and early afternoon
hours the front will still be west of the area and act as a
focusing mechanism for convection during the late afternoon and
evening hours as it crosses the region. CAPE during the
afternoon and early evening ahead of the front will be around
2000 J/Kg or higher with pwat values aoa 1.75 inches and DCAPE
around 1000 J/Kg. Divergence aloft during the late afternoon and
evening will be weak with winds at 35 kft expected to be a
maximum of 60 knots. With the potential for damaging winds and
hail SPC has expanded the slight risk to include the entire
forecast area tomorrow. High temperatures tomorrow will be in
the upper 80s to low 90s with lows Monday night in the mid 60s
to around 70.
Tuesday and Tuesday night are expected to be convection free as
the front will be offshore and high pressure along with drier
air will be building into the region. The upper level trough
will remain over the eastern US however with pwat values
dropping to under 1 inch by midday and 850-500 mb lapse rates
under 6.0 C/Km do not expect much in the way cloudiness and any
cumulus which develop will be vertically limited. Highs Tuesday
afternoon will be in the upper 80s to low 90s with lows in the
low to mid 60s.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
The upper level pattern will remain highly amplified and
progressive through the long term with changing conditions
across the region. Upper level trough will remain over the
eastern US through Friday while the surface will be controlled
by high pressure and drier air. This will keep partly clear
skies over the area with increasing clouds Thursday as a mid
level disturbance moves through the region. This feature will be
quickly ushered offshore as the upper level trough axis swings
through the region Friday afternoon. High pressure will be
moving across the region Saturday with increasing moisture
Saturday afternoon as return flow from the Gulf begins. By
Sunday the high will be east of the region with a trough of low
pressure moving into the area and possibly becoming a focusing
mechanism for convection. Temperatures through the long term
will be near to slightly below normal.
&&
.AVIATION /03Z MONDAY THROUGH FRIDAY/...
VFR conditions expected outside of any shower-storm activity
this evening and overnight.
Ridge offshore with south-southwest flow across the area. The
cumulus field has diminished across the area during the past
hour due to subsidence/loss of diurnal heating, drier air in the
central midlands. There may be some mid level capping as
suggested by RAP/HRRR soundings. However, the air mass remains
moderately unstable, deep layer shear is increasing across the
area ahead of an upper trough and upper heights will fall a bit
this evening. Thunderstorms have develop in the Upstate SC and
are tracking to the northeast. Based on radar trends think most
of the convection will stay north of the terminals this evening.
So expect mid level ceilings with southwest winds 5 to 10
knots. The boundary layer remains well mixed overnight so fog is
not expected. The HRRR is suggesting some stratus may develop
near the AGS/DNL terminals around daybreak but other guidance
remains VFR. Expect scattered cumulus to develop by mid to late
morning with mid level ceilings. Thunderstorm threat increases
in the afternoon as a cold front approaches from the Carolina
Mountains. The air mass is expected to be moderately to strongly
unstable and strongly sheared. Scattered strong thunderstorms
are possible mainly in the afternoon. The pressure gradient will
strengthen and expect southwest winds to gust to around 20
knots in the afternoon.
EXTENDED AVIATION OUTLOOK...Restrictions possible Monday evening
in scattered thunderstorms as a cold front moves through the
area. Otherwise, significant restrictions not expected.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...None.
GA...None.
&&
$$
Area Forecast Discussion
National Weather Service Corpus Christi TX
1058 PM CDT Sun May 26 2024
...New AVIATION...
.SHORT TERM...
(Tonight through Monday night)
Issued at 223 PM CDT Sun May 26 2024
Key Message:
- Dangerous heat continues Memorial Day with a major to extreme
risk of heat-related impacts
- Low chance (20%) of strong to severe showers and thunderstorms
4-9 PM over the Rio Grande Plains and northern Coastal Plains
Cloud coverage has been greater today than previously expected and
fortunately has limited surface heating. Temperatures currently in
the low to mid 90s with dewpoints in the upper 70s are causing
heat index values between 105 to 115. A few more hours this
afternoon will allow for these heat indices to bump up a few
degrees. Therefore, kept the Excessive Heat Warning and Heat
Advisory in effect through tonight and extended through Memorial
Day. Please continue to take heat precautions and follow the
guidance as described in the last paragraph of the long term
discussion.
Dewpoints remaining in the upper 70s to around 80 along with
increasing cloud coverage tonight will likely keep low
temperatures near the same, around 80. Currently, KCRP has
observed 150 hours straight of air temperatures at least 80
degrees, by far the earliest stretch of such length. The last
earliest stretch in the calendar year of at least 150 hours of 80
degree temperatures occurred last year from June 14-21st (166
hours). We don`t anticipate going below 80 until early Tuesday
morning at the earliest. This has led to 5 consecutive days of
record high minimums and 6 consecutive days of record heat
indices set at Corpus Christi. The lack of heat recovery
overnight and heat index values returning to 110-119 tomorrow has
warranted an extension of the heat products through Memorial Day.
Air quality will remain poor as HRRR near-surface smoke model
guidance continues to illustrate smoke ushering in from Central
America agricultural fires early this week.
Maintained the low chance (20%) of showers and thunderstorms late
Monday afternoon through Monday evening mainly for the Rio Grande
Plains and the northern tier counties. SPC has included all of
South Texas with the exception of the Coastal Bend in a marginal
risk for strong to severe storms. Throughout Memorial Day,
environmental conditions may become conducive over the Hill
Country and near the Sierra Madres in the warm sector east of the
dryline and south of stationary front over Central Texas. Any
storms that fire off may act as a lifting mechanism to help
overcome the cap between 4-9pm when cin is weakest. The
strengthening low-level jet and late afternoon sea breeze could
help aid in convection development. Confidence is low as CAMs
differ on keeping the convection over Mexico or persisting into
South Texas. Any isolated storm that does break the cap, has the
potential to bringing damaging winds and large hail with
instability near 5000 J/kg, DCAPE around 1300 J/kg, steep lapse
rates over 8 C/km, and effective shear around 50 knots.
&&
.LONG TERM...
(Tuesday through next Saturday)
Issued at 223 PM CDT Sun May 26 2024
- Low chances (10-25%) of rain chances daily this week
Quasi-zonal flow is expected to prevail in the long term as a weak
upper-level ridge will be parked to our south. Multiple mid-level
shortwave disturbances will move through the region, and with low-
level southeasterly flow in place, we should have plenty of moisture
to trigger low chances for rain and thunderstorms daily through
this week. However, it is a bit tricky to nail down locations and
amounts of rainfall, etc. as the weak ridge aloft won`t exactly
make the setup ideal. Additionally, with 700mb temperatures
remaining on the warm side, there will be decent mid-level capping
in place. Therefore, we are only including a low chance (10-25%)
for precipitation through next Sunday. Some periods of
thunderstorms and locally heavy rain may be possible at times, as
model SBCAPE values show 3000+ J/kg and PWAT values may reach 1.5-
1.75 inches. This is specifically true for Tuesday and Wednesday
as WPC has portions of the Brush Country and the northeast Coastal
Plains in a Marginal Risk (level 1 out of 4) for Excessive
Rainfall.
With the establishment of quasi-zonal flow, combined with slight
rain chances and increased cloud cover, high temperatures are
expected to be "cooler" this upcoming week compared to our recent
warm spell. Daytime highs are set to top out in the low to mid-90s
across the Coastal Plains, with the upper 90s to low 100s
expected farther west. Heat indices will remain generally below
112 degrees. Despite these "cooler" conditions, there remains a
medium to high chances (40-70%) of moderate to major heat-related
impacts, with a low to medium chance (10-40%) of an extreme risk
across portions of the Brush Country and the southern Coastal
Plains. This is due to anticipated poor overnight heat recoveries
that could impact individuals sensitive to heat and those without
adequate cooling measures, as well as some health systems and
heat-sensitive industries and infrastructure.
&&
.AVIATION...
(06Z TAFS)
Issued at 1044 PM CDT Sun May 26 2024
MVFR to IFR ceilings are expected in the eastern TAF sites
overnight. The likely timing of arrival for IFR ceilings will be
around 08-10Z. Some patchy fog could develop and mix in with haze
and further drop visibilities during the morning. COT will be the
only western site expected to briefly drop to MVFR ceilings.
Ceilings should transition to VFR at all sites by 15-18Z. There is
a low chance for showers and thunderstorms in the area during the
later half of the period. This will be reassessed in future TAF
issuances.
&&
.MARINE...
Issued at 223 PM CDT Sun May 26 2024
Weak to moderate south to southeasterly flow will continue through
Monday night. Weak to moderate onshore flow is expected Tuesday
through the end of the work week, with periods of strong 20-25
knot gusts on Friday. Seas will generally be between 4-5 feet,
increasing to 5-6 feet by next weekend. There will be low (10-25%)
chances of showers and thunderstorms each evening.
&&
.PRELIMINARY POINT TEMPS/POPS...
Corpus Christi 93 82 96 79 / 10 0 0 10
Victoria 94 79 97 76 / 10 0 0 20
Laredo 106 82 109 80 / 0 0 20 20
Alice 100 80 101 77 / 10 0 10 10
Rockport 91 82 90 79 / 10 0 0 10
Cotulla 105 82 108 79 / 0 0 20 20
Kingsville 96 81 98 77 / 10 0 10 10
Navy Corpus 91 82 90 82 / 10 10 0 10
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...Excessive Heat Warning until 8 PM CDT Monday for TXZ229-230-
239>243.
Heat Advisory until 8 PM CDT Monday for TXZ231>234-244>247-
342>344-346-347.
GM...None.
&&
$$
SHORT TERM...EMF
LONG TERM....KRS
AVIATION...NP/92
Area Forecast Discussion
National Weather Service State College PA
1111 PM EDT Sun May 26 2024
.SYNOPSIS...
A warm front will lift northeast into the state tonight, but
will likely stall its progress near or just to the east of the
Susquehanna Valley until later Monday.
Low pressure will pass over the Upper Great Lakes on Memorial
Day, dragging a cold front through late Monday/evening. An upper
level trough will build into the region for the remaining
portion of the week.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
The focus this evening is on an approaching band of strong to
severe thunderstorms entering Southwest PA at the nose of a
strong southwesterly low level jet. Latest HRRR, which should
perform well in a strongly forced scenario as this, tracks the
band of convection northeast across the entire forecast area
between 00Z and 06Z. However, it will be running into a much
less unstable environment, so anticipate a diminishing severe
weather threat. The best chance of severe weather should be over
Somerset County, where the 22Z SPC mesoanalysis shows capes in
the 500-1000J/kg range. RAP 0-3km shear vectors are around 30kt
and perpendicular to the convection, so can`t totally rule out a
brief QLCS tornado in the vicinity of Somerset Co, but the
greater threat is to the west of our area.
The band of showers and embedded tsra should lift north and east
of the forecast area by about 08Z tonight, as the associated
shortwave/low level jet lift into NY State. Generally rain-
free weather is expected during the pre-dawn hours with breaks
in the overcast. However, model guidance indicates an upsloping
southeast flow will yield developing stratus across the higher
terrain of Northern and Eastern PA.
Surging low level moisture and cloud cover should result in a
significantly warmer night than those recently, with min temps
in the 60s.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
Falling heights and surging pwats ahead of the next shortwave
lifting out of the Ohio Valley will spread numerous showers and
embedded tsra into the region later Monday morning. Initially,
low clouds and rainfall should hold temps and the severe wx
threat in check. However, breaks in the overcast/modest diurnal
heating, combined with favorable shear profiles, support
organized convection and a threat of severe weather during the
afternoon to early evening hours. The best chance of supercells
and an isolated tornado appears focused over the Susq Valley,
where low LCLs are anticipated and updraft helicity values from
at least one HREF member tops 150m2/s/2.
The most impressive pwats are progged to have shifted east of
the area during peak instability of the PM hours, so think any
flash flooding will be isolated at best. Ensemble mean qpf
between 0.25 and 0.50 inches appears the most likely rainfall
Monday for most of the area. However, HREF output supports
isolated totals near 2 inches associated with stronger tsra.
A seasonably strong surface low will track west of PA through
the Great Lakes Monday, dragging a trailing cold front through
the area Monday evening. The threat of showers/tsra will end
over most of Central PA with the passage of the front. However,
low level instability associated with a deepening trough over
the Grt Lks could result in late night showers over the NW Mtns.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
Medium range guidance continues to point to a period of cool
weather Tuesday through Thursday, as a deep upper level trough
pivots southeastward from the Great Lakes. Cold temps aloft
should support diurnally-driven showers/storms Tue and Wed,
with the highest POPs across the elevated heat source of the
Allegheny Plateau. The best overall chance of showers should
come with the passage of a strong shortwave on Wednesday.
PoPs will fall to slight chance on Thursday as drier air moves
in on the back side of the upper trough. This will begin a trend
toward drier and warmer weather Friday into Saturday, as the
upper level trough axis shifts east of PA and high pressure
builds into the region. An approaching frontal system could
bring our next round of showers/storms by next Sunday.
&&
.AVIATION /03Z MONDAY THROUGH FRIDAY/...
A fast moving line of convection will move northeast through
central PA this evening. The line will be strongest as it
impacts JST and then AOO, then weaken as it moves northeast
into east-central PA after midnight. Cigs will continue to
trend towards MVFR/IFR conds near and after 06Z, with lowest
cigs expected in the central ridge/valley region.
Included a several hour or longer period of LLWS at all TAF
sites later this evening into at least the early morning hours
Monday.
IFR to MVFR cigs will continue through much of Mon in the east.
Scattered TSRA are expected to form in the afternoon and
evening, perhaps forming into a line of convection. Cigs will
trend higher late in the day outside of thunderstorms as drier
air works in from the west.
Outlook...
Tue-Wed...Brief restrictions are possible in scattered showers,
but much of the time should be VFR.
Thu...Predominantly VFR.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SYNOPSIS...Lambert/Dangelo
NEAR TERM...Fitzgerald
SHORT TERM...Lambert/Fitzgerald
LONG TERM...Evanego/Colbert
AVIATION...Lambert/Colbert
Area Forecast Discussion
National Weather Service Des Moines IA
1055 PM CDT Sun May 26 2024
...Updated for the 06z Aviation Discussion...
.KEY MESSAGES...
- Some chances for showers and storms into Tuesday. A few
stronger storms and gusty winds possible northeast Monday.
- Dry Wednesday, then chances for showers and storms return off
and on later this week and into the weekend
- Fairly seasonal temperature regime continues
&&
.DISCUSSION...
Issued at 245 PM CDT Sun May 26 2024
Our weather pattern will remain somewhat active for the next
few days, albeit not to the extent as last week. After the
passage of Plains short waves to our south tonight, our weather
will be more influenced by the northern stream, and what will be
northwest flow behind a Great Lakes long wave trough. At onset
into tonight, have continued the mention of low chances
southwest per the latest mesoanalysis which shows uncapped ~1000
J/kg MLCAPEs south and west, and the latest RAP and HRRR still
hint at such development. The latest visible satellite trends
are uninspiring however, as is the surface moisture convergence, so
confidence in this occurrence is low. Any potential that there
is should end heading into mid-evening. The next concern would
be fog development overnight northeast where stratus continues
to linger late this afternoon, and temp/dewpoint spreads remain
5F or less. Although guidance doesn`t suggest much, this can be
a recipe for fog development, so have introduced patchy fog
wording for a start in those areas.
By tomorrow our attention will turn to the current MT short
wave as it reaches the Upper MS Valley by Memorial Day
afternoon. This will spread QG forcing mainly to our northeast,
but also modify the environment such that steep low level lapse
rates will be in place below 2km. This is expected to develop
scattered showers and storms over the northeast half of the
forecast area, and may result in some potential for somewhat stronger
convection with the potential for gusty winds with any
healthier cells. Soundings suggest gusts ~30 mph are possible
just due to mixing, with the potential for higher convective
gusts due to the steep lapse rates. 12Z HREF wind probabilities
suggest this as well with many members depicting wind potential.
The lack of adequate surface vorticity and boundaries may limit
the potential somewhat, but funnel clouds will be possible
northeast as well due to the proximity of the short wave and
200+ J/kg 0-3km CAPEs during peak heating and mixing. Machine
learning guidance from Nadocast also corroborates that potential
with small tornado probabilities. A bit farther south and west
the funnel environment would diminish with effective shear
rising to 40+ kts farther removed from the short wave, but this
would also result in a non-zero potential for some hail if
cells in the instability axis can tap that better deep shear.
This should all be diurnally driven, leading to dry conditions
later in the evening and overnight. Instability appears to be
more limited, but another short wave dropping into the Great
Lakes trough will introduce low chances for showers and a few
storms again into peak heating Tuesday, more driven by synoptic
lift in this instance.
We get a brief respite from precip chances midweek with surface
high pressure Wednesday and then upper level ridging into
Thursday. A central/northern Rockies long wave trough will begin
influencing our weather late in the week however with a few
short waves through its base Friday and Saturday. This will
reintroduce a few days with chances for showers and a few
storms. The severe weather potential appears low however based
on GEFS based CSU ML guidance, and deterministic GFS and EC
output both keeping any appreciable instability to our south and
west.
&&
.AVIATION /06Z TAFS THROUGH 06Z TUESDAY/...
Issued at 1051 PM CDT Sun May 26 2024
KALO remains in the vicinity of nuisance MVFR ceilings, which
may yet take a couple of hours to move out. At that point, all
sites will be VFR through a majority of the period. Have trimmed
back VCSH mentions in/around 12z Monday with guidance trending
weaker. Have also pulled VCTS mentions at KDSM/KOTM during
latter portions of the period with questionable southern extent
of convection tomorrow afternoon. Winds will pick up a bit out
of the NW with gusts into the mid 20s kts by the late morning
and through the afternoon.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
DISCUSSION...Small
AVIATION...Curtis
Area Forecast Discussion
National Weather Service Peachtree City GA
1031 PM EDT Sun May 26 2024
...Late Evening Update...
.UPDATE...
Issued at 1016 PM EDT Sun May 26 2024
Other than a few clouds all is quiet across North and Central
Georgia. Though this will be short lived as a line of showers and
thunderstorms, some being strong to severe, will approach the
area from the northwest in the early hours of Monday (Memorial
Day). Storms are currently slated to arrive in the northwest as
early as 3 to 5AM. Primary concerns, particularly in far
northwest Georgia, will be the potential for strong damaging
winds, hail up to an inch, and a few tornadoes. Additionally, low
clouds, locally heavy rainfall, frequent lightning and gusty
winds will accompany the line as it moves through Monday morning.
Latest hi-res trends indicate some weakening in the line as it
approaches the metro before reinvigorating tomorrow afternoon.
Made some tweaks to reflect current trends, though overall the
forecast remains on track.
&&
.SHORT TERM...
(This afternoon through Monday)
Issued at 227 PM EDT Sun May 26 2024
Clear and fair conditions today, with some nice cumulus across the
region. A few showers with potentially a rumble of thunder are
possible in far Northeast GA. These will be aided by outflow from an
mcs moving through TN and KY, however further south into our area
will remain dry due in part to some weak CIN. With the clear
conditions, temps will be toasty with highs reaching over 90 for the
vast majority of the area.
Looking overnight tonight into Memorial Day, a line of thunderstorms
will make its way out of TN. This line will have the potential to be
severe. Current models are indicating MUCAPE ahead of the line of
~2000 J/Kg. Shear will be high as well with 40 to 50 kts of speed
shear and SRH values of up to 150 m2/s2. CAMs are having a hard time
keying into the exact timing for the line to move through, however
the HRRR has probably been the most consistent. For now will look
for storms to move into North GA around 10Z and descend southward.
The challenge will come with the evolution of the line as it
descends through the Metro. Most models are weakening the line as it
moves through North GA. This seems suspect given MCS trends, the
shear available, and how cold-pools are handled in CAMs. As such the
more likely scenario will see the line move well through the metro
similar to yesterday. This should limit thunderstorm potential later
in the afternoon. Areas where the line does weaken tomorrow morning,
particularly in areas south of I-20, a few storms could redevelop as
the cold front itself moves through and become strong to severe.
We will closely monitor the evolution of the line tomorrow. The
main hazard will definitely be wind. Lapse rates also indicate a
hail threat, and brief "spin-up" tornadoes are not out of the
question.
QPF across the area hangs around the 0.5 to 1.5" at this time,
however locally heavy rainfall is likely with right moving storm
motions.
Temperature-wise tomorrow, have opted to drop temps from model
guidance by a degree or two to account for reduced solar heating in
the morning.
SM
&&
.LONG TERM...
(Tuesday morning through next Saturday)
Issued at 227 PM EDT Sun May 26 2024
Fairly quiet weather expected for the long term portion of the
forecast.
Monday`s front should settle to the south of the CWA by early
Tuesday. The models are progging a couple of waves to move along the
old boundary, but any precip should remain well to the south of the
outlook area. By the end of the week, a ridge in the mid levels
begins to build. Suspect the models are trending towards climatology
for pops by the weekend.
Overall, the forecast should remain mostly dry with temperatures
near normal. No major changes needed.
NListemaa
&&
.AVIATION...
(00Z TAFS)
Issued at 744 PM EDT Sun May 26 2024
VFR conditions will gradually give way to gradually deteriorating
conditions after 06z. A line of shra/tsra will move into the
region as early as 07-08z, approaching the metro ATL area as early
as 10-12z, and gradually moving southward. Cigs anticipated to
reach MVFR (possibly IFR) criteria and gusts winds (20 to 27kts)
as the line pushes through. As a whole, SW/WSW winds will largely
remain elevated through the period 5 to 12kts with gusts picking
up Monday aftn. Winds behind the line will switch to the W/WNW
with speeds diminishing after 23z. Cigs are expected to begin
improving after 18z.
//ATL Confidence...00Z Update...
Medium confidence on timing of convection, IFR potential and wind
gusts. High confidence on all other elements.
07
&&
.PRELIMINARY POINT TEMPS/POPS...
Athens 69 84 66 88 / 40 50 20 0
Atlanta 71 85 68 88 / 30 60 20 0
Blairsville 64 79 59 79 / 70 80 10 0
Cartersville 68 84 63 86 / 50 60 10 0
Columbus 72 86 69 91 / 10 50 30 0
Gainesville 68 82 65 85 / 50 60 10 0
Macon 70 86 68 90 / 10 50 30 10
Rome 69 85 64 86 / 60 60 10 0
Peachtree City 70 84 65 88 / 20 50 20 0
Vidalia 71 89 71 90 / 10 50 50 10
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SHORT TERM...SM
LONG TERM....NListemaa
AVIATION...07
Area Forecast Discussion
National Weather Service Hastings NE
641 PM CDT Sun May 26 2024
.KEY MESSAGES...
- Isolated showers and thunderstorms may develop late this
afternoon and move across the area from northwest to southeast
this evening. There may be some gusty winds and small hail
with these storms, but organized severe weather is not
expected.
- Dry and pleasant weather is expected Memorial Day with highs
in the 70s and low 80s. Monday will be breezy, with gusts
north of I-80 up to 30 mph in the afternoon.
- Most areas remain dry Tuesday and during the day Wednesday,
with showers and thunderstorms returning to much of the area
Wednesday evening, persisting through the end of the work week
and slight chances continuing into next weekend.
&&
.DISCUSSION...
Issued at 158 PM CDT Sun May 26 2024
This evening:
A shortwave moving across the central Plains will allow showers
and storms to develop later this afternoon and this evening.
CAPE and shear values are not super impressive, but steep mid-
level lapse rates (8 degrees C/km) and DCAPE values of near 1000
J/kg indicate the potential for an isolated marginally severe
hail/wind threat...and the HRRR has been consistently trying to
latch on to convective gusts of around 50 mph for the past few
hourly runs. Still, while an isolated storm may produce
marginally severe hail/wind as they move into the area, this is
expected to be isolated and storms should weaken as they move
southeast, especially after sunset.
Monday and Tuesday:
Monday, high pressure will move over the region, leaving the
area mostly dry with highs in the 70s and low 80s both days.
Monday will be breezy, especially north of I-80, where gusts up
to 30 mph are expected in the afternoon.
Tuesday night and Wednesday:
A messy shortwave / area of low pressure will develop across SW
KS, OK and northern TX Tuesday evening, and a few showers and
storms may make it as far north as our southwestern counties
Tuesday night and Wednesday AM. Otherwise, an upper ridge will
help keep the area dry and warm the rest of Wednesday...highs
will be in the 70s and low 80s once again.
Wednesday night through Friday:
The pattern is expected to change to a wetter one as the ridge
is pushed out of the area and a series of troughs/shortwaves
march across the region. Starting Wednesday evening, there will
be at least a 30 percent chance of showers and/or thunderstorms
through Friday evening. Currently, the best chances look to be
Thursday evening/night as one of the stronger fronts move
through, but model guidance does diverge some on the timing of
this and how widespread precipitation will be, so that can be
expected to change. While not in an official outlook, this
stronger frontal passage may also be our next chance for severe
weather, but details are too murky to be certain...just that it
will be something to watch out for.
Next weekend:
Going into next weekend, there will be a slight chance of
showers and storms but model guidance diverges far too much to
say beyond that. Obviously, the forecast for next weekend will
resolve more throughout the week.
&&
.AVIATION /00Z TAFS THROUGH 00Z TUESDAY/...
Issued at 637 PM CDT Sun May 26 2024
VFR conditions are expected through the forecast period at both
terminals. There is a line of showers and thunderstorms
extending from northwest of Broken Bow to southeast of North
Platte, moving to the east-southeast. These are still a couple
of hours away from the terminals and may result in some gusting
winds, wind shifts, and some slight reductions to visibility.
Once that line moves through the area, conditions should stay
dry for the rest of the night.
Winds become light and variable once the storms roll through,
turning to the northwest overnight. Winds are expected to
increase to around 10-15kts tomorrow morning.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...None.
KS...None.
&&
$$
DISCUSSION...Hickford
AVIATION...Wekesser
Area Forecast Discussion
National Weather Service Grand Junction CO
238 PM MDT Sun May 26 2024
.KEY MESSAGES...
- Isolated showers and thunderstorms are possible over the
northern mountains this afternoon with mostly dry and warmer
conditions area wide.
- Drier and warmer conditions expected this week with
temperatures warming to five to ten degrees above normal by
mid week.
- Precipitation chances remain low through most of the week with
any storm activity favoring the high terrain during the
afternoon period.
&&
.SHORT TERM /THROUGH MONDAY NIGHT/...
Issued at 238 PM MDT Sun May 26 2024
While much of the moisture from the previous storm system
yesterday has vacated the area, enough lingering moisture left
behind in a westerly flow is resulting in plenty of cumulus
clouds forming over the northern and central high terrain.
Visually speaking, these cumulus do not have much vertical
growth to them, hence very little if any shower activity
remains and is seen on radar. The hi-res CAMs are indicating
some isolated storms this afternoon favoring the northwest
Colorado mountains. The HRRR seems to have a better handle on it
than the overly aggressive NAMNest, so not really expecting too
much storm activity other than perhaps some very isolated
storms over the Park Range and Flattops late this afternoon,
with quick dissipation by sunset. A little bit of 0-3km MLCAPE
and some bulk shear remains over the Park Range according to
mesoscale analysis, but instability is fairly low otherwise.
For the most part though, drier and warmer conditions can be
expected today with breezy conditions, although much less than
yesterday given less storm activity.
High pressure continues to move in from the southwest with its
axis stretching over the Great Basin, although the flow will
shift to more southwesterly allowing some moisture to advect
back into the area. Regardless, Monday is expected to be mostly
dry with some isolated storm activity possible over the San
Juans during the afternoon. The warm advection continues with
highs on Memorial Day near to slightly above normal, which will
be about 4 to 8 degrees warmer than today.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
Issued at 238 PM MDT Sun May 26 2024
By Tuesday morning, the ridge axis will be centered over eastern
Utah and Western Colorado extending north over Montana into
Saskatchewan on its eastward trek across the region as a deep
low pressure system descends out of the Gulf of Alaska along the
British Columbia Coast. By Wednesday morning, the low will have
turned east to track across northern BC, Alberta, Saskatchewan
and Manitoba to the Hudson Bay by next Sunday. The trough
associated with this low will extend down into the Pacific
Northwest Tuesday shifting the flow aloft to the southwest
across the region to advect warm air into the area, warming
temperatures five to ten degrees above normal. These warm
temperatures will continue through Thursday as the trough tracks
along the Canadian Borders putting the region under a dry, more
zonal flow. Look for skies to remain mostly clear across the
region with afternoon build ups over the mountains from residual
moisture and diurnal heating. Could even see a few isolated
showers along the Divide each afternoon through the week. Cooler
air will push south into the northern 2/3rds of region late
Thursday into Friday and Saturday as the trough to the north
moves east of the Rockies, dropping temperatures back to near
normal for the end of May and first of June. The southern areas
along and south of the San Juan mountains will stay about five
degrees above normal through this period.
Looking way out into the extended period, next Sunday into the
following week, the ensemble models zero in with good agreement
on a strong ridge building in over the Intermountain West and
troughing over the Eastern States as the low settles in the
Hudson Bay. This is a common strongly persistent pattern over
the CONUS that can last for weeks at a time, characterized by
hot and dry conditions for eastern Utah and Western Colorado
that can usher in the start of the fire season. This far out,
there isn`t a lot of confidence in this forecast, but the fact
that the ensembles concur with low dispersion among the members
makes this something to watch. Stay tuned through the coming
week for updates.
&&
.AVIATION /18Z TAFS THROUGH 18Z MONDAY/...
Issued at 1112 AM MDT Sun May 26 2024
Expect mostly VFR conditions across the region today with breezy
to gusty west winds through the afternoon. The exception is residual
moisture generating periods with cloud decks just below ILS
breakpoints for KASE and KEGE this afternoon. Look for skies to
clear out overnight across the region with light terrain driven
winds through the remainder of the TAF period.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...None.
UT...None.
&&
$$
SHORT TERM...MDA
LONG TERM...DB
AVIATION...DB
Area Forecast Discussion
National Weather Service Grand Rapids MI
827 PM EDT Sun May 26 2024
.KEY MESSAGES...
- Risk for Storms into Tonight
- A few Thunderstorms possible Memorial Day, especially in the
evening
- Cool and unsettled weather continues Tuesday
- Dry weather with increasingly warmer temperatures Wed through Fri
- Rain chances return for next weekend
&&
.UPDATE...
Issued at 819 PM EDT Sun May 26 2024
We`re watching radar trends this evening and specifically the band
of strong/severe storms moving off of northeast IL just ahead of
the cold front. Mesoanalysis indicates 1k j/kg SBCAPE over the
far southwest cwa west of US-131 and as far north as northern
Ottawa County. However, progs are for this SBCAPE to diminish to
500 j/kg or less by 10 pm. Bulk shear, however, remains aoa 35kts
for the next several hours. Thus, the stronger storms that make it
across the lake will likely be along the I-94 corridor. The
threat for strong storms will diminish overnight once the cold
front moves through.
&&
.DISCUSSION...
Issued at 252 PM EDT Sun May 26 2024
- Risk for Storms into Tonight
One line of showers/thunderstorms will be pushing northeastward
through the CWA now through 7 or 8pm. With a narrow corridor of
elevated DCAPE values out ahead of it, gusty winds appear to the be
main risk. Upstream in northern IN there were some weather stations
that recorded gusts in the 20 to 30 knots range, KVPZ and KMGC. The
latest HRRR suggests we will see some wind gusts similar to those in
IN across our CWA, especially south. Isolated higher values are
possible. It`s worth noting that higher surface dewpoints were
being reported at a several sites downwind of Lake Erie with KTOL
showing 66 degrees. Thus there are elevated values of instability
and effective deep layer shear reaching now towards Jackson
County. That could be one area to monitor for possible enhanced
winds/convection.
By 8 pm the bulk of the activity should be moving northeast of KLAN
and KMOP. Additional storms are possible during the evening hours
but the coverage is expected to be scattered. However after midnight
the instability builds again with an increased potential for MU CAPE
values to make a run at 1000 J/kg ahead of the cold front. Thus,
the convection could increase once again. Deep layer shear is
forecast to diminish as the instability builds overnight so the
risk for organized convection will be limited.
- A few Thunderstorms possible Memorial Day, especially in the
evening
The atmosphere destabilizes as we go through the afternoon and into
the evening. With a cold pool overhead, scattered showers and a few
thunderstorm are expected to develop. A digging mid level vort max
arrives from the west northwest 02z to 06z and that will likely lead
to an increase in the activity, especially for the western zones.
Ensemble 6hr qpf values remain fairly low with most areas seeing
under a tenth of an inch and trends don`t really show much
increase/decrease.
- Cool and unsettled weather continues Tuesday
We will see more of the same weather from Monday, on Tuesday and
Tuesday night once again. This holds true as the broad upper
cyclonic flow and cold pool aloft remains entrenched over the upper
Great Lakes. The models are indicating that at least 3 to 4 short
waves will be rotating around the upper low and across Southern
Lower. This will ensure that cool weather prevails, and occasional
showers will remain possible at times. Tuesday afternoon/evening
will see a chance of some thunder as diurnal instability combined
with the cold pool aloft will provide sufficient instability for
some thunder.
- Dry weather with increasingly warmer temperatures Wed through Fri
There has been better agreement that the rain chances from early in
the week should pretty much move out of the area by Wednesday
morning. The final short wave in the series looks to pass through
late Tuesday night, before the upper ridge axis will move close
enough to keep the area dry Wednesday. This cooler air holding in
for Wednesday, combined with high pressure at the sfc will allow for
a fairly cool night Wednesday night/Thursday morning. It does look
like there is a chance of some frost across Central Lower.
Otherwise the upper ridge slowly building toward the area will bring
plenty of subsidence with it over the area, will keep the area dry
for at least a couple of more days through Friday. We will see max
temperatures warm from the 60s on Wednesday, to approaching 80 by
Friday as warm return flow sets up in the lower levels.
- Rain chances return for next weekend
We continue to watch for the potential for a period of rain sometime
next weekend, however the timing remains a bit uncertain. The key
factor in this scenario and the eventual timing of the rain will be
mostly based on the evolution of the upper low off of the New
England coast. This low is expected to close off a bit more, and
will hold up the weather pattern across the CONUS to some degree.
The stronger and more closed off it is, the more likely the pattern
will hold upstream. Rain could start moving in as early as by
Saturday afternoon, or as late as holding off until Sunday or beyond.
&&
.AVIATION /00Z TAFS THROUGH 00Z TUESDAY/...
Issued at 733 PM EDT Sun May 26 2024
As the earlier round of thunderstorms exits the area, all sites
will be initially VFR. After 02z, scattered showers and
thunderstorms will enter West Michigan and expand east over the
next few hours. Do not currently have confidence in TSRA directly
impacting the terminals to support TAF inclusion due to widely
scattered nature of TSRA but will reassess and amend as needed.
Locally gusty winds and IFR conditions are possible in any storms.
With the showers come lower cigs, initially MVFR before becoming
IFR at all sites after 05z (MKG may briefly go LIFR). Low cigs
remain through much of the day before lifting to MVFR for the I94
TAF sites Monday afternoon, and Monday Evening LAN becomes MVFR
while MKG/GRR become VFR. Scattered showers will continue through
the day Monday. South- Southeasterly winds tonight veer to
westerly Monday with 10-15 knot winds, gusting to 25 knots Monday.
&&
.MARINE...
Issued at 252 PM EDT Sun May 26 2024
Earlier we did issue a Small Craft Advisory and Beach Hazards for
Memorial Day. High confidence exists for winds to increase to 20
knots or higher and waves to reach 4 feet for much of the area.
North of Whitehall there may be a delay in the onset of hazardous
conditions as the surface low will be in that region 12z Monday,
however by noon conditions will deteriorate in that region.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...Beach Hazards Statement from 8 AM EDT Monday through Monday
evening for MIZ037-043-050-056-064-071.
MARINE...Small Craft Advisory from 8 AM to 8 PM EDT Monday for LMZ844>849.
&&
$$
UPDATE...04
DISCUSSION...MJS/NJJ
AVIATION...Thomas
MARINE...MJS/Hoving
Area Forecast Discussion...Updated
National Weather Service Lincoln IL
859 PM CDT Sun May 26 2024
.KEY MESSAGES...
- Another round of stronger storms are possible this evening for
areas south of I-72. Discrete cells with the threat of large
hail and isolated tornadoes are initially forecast before
becoming a line of thunderstorms, with hail and damaging winds
as the hazards.
- Localized heavy rain and flooding for areas near and south of
I-70 as storms, bringing high precipitation amounts, pass
through this evening.
- The weather calms down after tonight, providing us a benign week
of weather. The next chance (30-40%) of showers and
thunderstorms arrives Friday night into Saturday.
&&
.UPDATE...
Issued at 859 PM CDT Sun May 26 2024
A QLCS/linear thunderstorm system continues eastward along/south
of I-70 this evening, generating reports of wind damage and large
hail, but so far no confirmed tornadoes this far north. However,
a severe thunderstorm watch continues north of I-70 and a tornado
watch south of I-70. This feature should exit southeast IL into
Indiana by 10 PM. The cold front associated with this system
appears to be roughly along the Illinois River as of 830 PM,
however subsidence and increasing CIN behind the QLCS should
eliminate the severe weather threat. Overnight, the front will
continue to traverse the central IL forecast area, exiting the
area by around sunrise. Overnight, a few more showers and
thunderstorms could be triggered by the front, while winds will
switch to northwesterly and trigger some cooler temperatures with
lows in the mid 50s to lower 60s south of I-70. Updates have been
sent for trends in precipitation coverage this evening, and a
couple degrees off of lows for tonight.
37
&&
.DISCUSSION...
Issued at 233 PM CDT Sun May 26 2024
The next round of storms is possible this evening, mainly near and
south of I-72. There is some uncertainty whether this round will
make far enough north to be in the CWA or not but the newest HRRR
and ARW show it just south of I-72. These are likely to be supercell
structured with a large hail and tornado risk early in the event
(21z-00z). Then will merge into a more linear form as it exits
southeastern Illinois, posing more of a hail and damaging wind risk.
The HRRR 12z soundings show STP of 1, SHIP of 2.1, midlevel lapse
rates of ~8 C/km, and PWATs of 1.5-1.9 inches for this evening. We
kept the Flood Watch for south of I-70 because of the higher PWATs,
and the potential for training cells.
After this evening, the weather will clear out. Memorial Day will be
nice and dry with highs in the low to mid 70s. There could be some
breezy winds at times, particularly late in the day. From the 12z
HREF, there is a 50-60% chance of wind gusts greater than 30 mph
in the late afternoon into the evening hours, then calming down by
the overnight hours.
Temperatures through the extended forecast will gradually warm up by
next weekend. Low to mid 70s for highs through Thursday, then
reaching the upper 70s to low 80s. The next significant chance for
precipitation comes Friday night into Saturday, with 30-40% chance
of showers and thunderstorms.
Copple
&&
.AVIATION... (For the 00z TAFs through 00z Monday Evening)
Issued at 714 PM CDT Sun May 26 2024
A few thunderstorms will be near KDEC and KCMI until 02Z, then all
thunderstorm activity is expected to shift well south of the
central IL terminals as a cold front moves through this evening.
An area of BKN cigs over the upper Midwest will move southward
into the area behind the cold front, expected to reach KBMI, KCMI,
and KDEC northeastward by around 12Z, and linger through the
morning hours. Expect northwesterly winds overnight, although the
first few hours will see some lingering SW winds from I-55
eastward. Winds will be 8-12 kts with gusts 15-20 kts.
37
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
Flood Watch until 1 AM CDT Monday for ILZ066>068-071>073.
&&
$$
Area Forecast Discussion
National Weather Service Northern Indiana
641 PM EDT Sun May 26 2024
.KEY MESSAGES...
- Scattered showers and storms will remain possible into
tonight. A few strong to locally severe storms cannot be ruled
out, though the overall severe threat has diminished.
- Lingering showers and thunderstorms may impact activities
Memorial Day through Wednesday.
- Hazardous swimming conditions for Lake Michigan beaches in La
Porte County in Indiana and Berrien County in Michigan
Memorial Day through Wednesday.
&&
.UPDATE...
Issued at 520 PM EDT Sun May 26 2024
Line of sub-severe convection along a fgen/MCS outflow should
exit our eastern zones by 22/23z with a lull in activity for
most locations in its wake. Second round of convection for this
evening/overnight continues to look diminished/limited with most
of the area now worked over, with a more robust MCS on target
to pass south of the area during this time. Incoming trough on
the leading edge of an incoming vort max and weak sfc
reflection (now near WI/IL border), and some added convergence
from outflow bubble on the northern fringe of the maturing OH
Valley MCS, will bring renewed chances for widely scattered
showers/storms tonight. Cannot rule out an isolated strong-
severe cell into areas mainly west of IN-15 9p,-midnight EDT as
there will be adequate shear along the incoming sfc trough.
Buoyancy will be somewhat limited however with the bulk of the
energy going to what should be a dangerous MCS tracking east
along the OH River. Only minor adjustments made to PoPs/Sky
cover trends into tonight.
&&
.DISCUSSION...
Issued at 1220 PM EDT Sun May 26 2024
A deepening area of low pressure approaches the Western Great Lakes
today and moves into the Northern Great Lakes by Monday morning. As
it does so, a warm front pushes into Michigan by this evening.
Models expect low lapse rates to be the highest in the I-69 on
eastward where the greatest amount of sunlight and least amount of
thunderstorm overturning resides into the afternoon ahead of the
approaching storm-filled warm front. Much of the shear lags behind
this warm front so the most likely hazards out of a line like this
include strong to damaging wind gusts up to 60 mph with heavy rain
that could lead to flooding. There is some progressive nature to
this initial line so that will likely limit the residence time of
the rather moist ingredients including surface (into the 60sF) and
low level dew points (above 10C in many southern locations).
There has been some question about what happens behind this line. Do
we get clearing or does a potential cold pool keep cloud cover
around enough to restrict recovery of instability for an evening
batch of severe thunderstorms? Additionally, what time do storms
initiate? As late as the the 00z models, there were still a few
models that hang onto a possibility of pop storms after the line,
but it appears 12z guidance has since backed off that possibility.
The 6z RAP seemed keen on initiating around 5pm, but that seems less
likely than some of the other models bringing a line through our
southern zones or just to our south around 8pm. By this point, shear
would be better established with the low level jet overhead and
helicity would be present as well allowing the introduction of the
hazard of a few tornadoes. The mid level lapse rates are shown to be
replenished behind the initial warm front line that had 8C/km mid
lapse rates to work with this morning. This will also make large
hail a possibility with the potential afternoon resurgence. If
storms do initiate behind the line, storm motion will also be in
question as the continued moist environment could allow any slower
moving storms to produce quite of rain in a short time frame. The
NAM40 also seems keen on keeping some storms southeast of US-24 into
the overnight with strong to damaging wind and large hail being the
main threats along with heavy rain that could lead to flooding.
Aside from the lower res NAM, the HREF suite brings a midnight or
1am end time to this second batch of strong to severe storms with
potentially a few isolated cells thereafter as the EML and lingering
instability could keep a few cells going after dark. Again, 12z
guidance appears to back off this second batch possibility
altogether.
The cold front moves southeast vacating the area Monday morning
allowing surface dew points to drop back into the 50s indicating the
dry air mass behind the front. But it`s a quick reprieve as another
wave approaches the area for Monday night. Even the NAM only has 100
to 500 J/kg of MUCAPE around for this episode which indicates weak
thunderstorms would be the expected outcome at strongest outcome.
Highs Monday will also be cooler, in the upper 60s and low 70s with
the negative theta-e advection behind the previous departed
cold front. Still not much cooler for highs on Tuesday with
upper 60s to low 70s, but models want to generate some more
instability to the tune of 500 to 1000 J/kg, which would
indicate more thunderstorms are possible during the afternoon,
especially as another broad area of vorticity approaches Tuesday
afternoon/night.
Behind this area of vorticity, surface high pressure comes in and is
expected to provide dry weather from mid to late week as a large
ridge stations itself over the Central CONUS. Some lingering
moisture may be able to sprout a few showers Wednesday morning, but
that should be east of I-69. Expect 60s for Wednesday that trend
warmer, reaching the 80s on Sunday. Our next chance for rain likely
holds off until late Saturday.
&&
.AVIATION /00Z TAFS THROUGH 00Z TUESDAY/...
Issued at 641 PM EDT Sun May 26 2024
High MVFR to low VFR cu will fill in early this evening as a
warm sector briefly builds in tonight. Cold front does work
east through the area otherwise with chances for widely
scattered showers and a few storms at KSBN mid evening through
the early overnight, and at KFWA mainly after midnight. Winds
then turn to the wnw post-frontal with MVFR stratocu filling in
later tonight into tomorrow.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...None.
OH...None.
MI...Beach Hazards Statement from Monday morning through Monday
evening for MIZ177-277.
MARINE...Small Craft Advisory from 8 AM to 8 PM EDT Monday for LMZ043.
&&
$$
UPDATE...Steinwedel
DISCUSSION...Andersen
AVIATION...Steinwedel
Area Forecast Discussion
National Weather Service North Platte NE
632 PM CDT Sun May 26 2024
.KEY MESSAGES...
- Thunderstorms late this afternoon and early this evening pose
an isolated threat of large hail and wind damage. The area of
concern is generally across northwest Nebraska west of highway
83.
- Thunderstorms are likely Wednesday through Friday and the
potential for severe weather is under review the SPC.
- Marginal Excessive Rainfall Risk...some storms Wednesday and
Thursday may produce locally heavy rainfall which could
produce flooding in some areas.
&&
.SHORT TERM /THROUGH MONDAY NIGHT/...
Issued at 338 PM CDT Sun May 26 2024
A few severe thunderstorms with large hail are developing across
swrn SD this afternoon. The RAP model suggests these and other
potentially strong or severe storms will develop across nwrn
Nebraska this afternoon. Upscale growth is predicted by the RAP
model. Storm activity will move southeast through wrn and ncntl
Nebraska this afternoon and this evening before exiting the
region around 04z tonight.
Storms will be operating in and environment of steep lapse rates, 20-
30kt winds at h500-300mb, limited moisture and MLCAPE. Stronger
winds aloft and an upper level disturbance are operating across nwrn
Nebraska and this could certainly be influencing the downstream
environment.
POPs this afternoon and this evening use the short term model blend
plus the HRRR and RAP models. A 50 percent coverage limiter is in
place as a hedge against the more aggressive upscale growth the HRRR
model shows. The reason for this is simply, the CAMs over-forecast
storm coverage Saturday night. The RAP model forecast was more
conservative Saturday.
There are no rain chances Monday or Monday night. The storm system
operating over the Midwest will lift through the Great Lakes and
send a back door cold front into Nebraska. The models are in good
agreement building heights across the cntl Rockies in response to a
developing upper level trof across the West Coast. As suggested by
the HREF, this should present a stable environment across wrn/ncntl
Nebraska.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
Issued at 338 PM CDT Sun May 26 2024
The upper level low off the coast of British Columbia will move
inland initiating high latitude cyclogenesis across Alberta by
Wednesday. Deep moisture return will develop across the Great
Plains; initially across the high Plains, but spreading east
toward the Missouri Basin by Friday. Chance to likely POPs are
in place Wednesday through Friday with the best rain chances
across the high Plains Wednesday and spreading east Thursday and
Friday. There is a chance a front will have dropped through
wrn/ncntl Nebraska Friday closing off the warm sector. Severe
weather appears possible Wednesday and Thursday, and Friday also
depending on the progress of the front.
The storm environment across wrn/ncntl Nebraska will feature modest
winds aloft, WSW25-35 kts at h500-300mb, but low level winds, S20-30
kts at h850-700mb result in effective shear of 40 to 50 kts. WPC
suggested a marginal Day 4-5 ERO for Wednesday and Thursday which is
consistent with the fairly strong h850-700mb moisture transport in
the GFS and ECM. SPC is monitoring the severe weather potential for
this system.
There are no other significant rain chances in the extended forecast
but it`s important to remember strong daytime heating, a projected
warm front Tuesday and residual instability next weekend could
set off isolated to perhaps scattered thunderstorms in some
areas.
&&
.AVIATION /00Z TAFS THROUGH 00Z TUESDAY/...
Issued at 632 PM CDT Sun May 26 2024
A couple aviation weather concerns exist through the forecast
period, mainly scattered thunderstorms this evening and blustery
winds tomorrow. The bulk of the storm coverage this evening will
be from VTN to LBF and terminals east, then tapering after
sunset. Northwest winds strengthen around sunrise tomorrow with
gusts to 20 kts in the south (LBF) and 30 kts north (VTN).
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SHORT TERM...CDC
LONG TERM...CDC
AVIATION...Snively
Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
906 PM CDT Sun May 26 2024
.KEY MESSAGES...
- Showers and a few thunderstorms are still expected tomorrow
with a few stronger storms possible across far southern
Minnesota.
- Things will remain fairly quiet with seasonable temperatures
with the next chance for widespread rain arriving late in the
week.
&&
.UPDATE...
Issued at 854 PM CDT Sun May 26 2024
Given trends with the HRRR and RAP, have increased PoPs quite a
bit for tonight through Memorial Day for MN in particular.
Scattered showers across the Dakotas will continue east through
the night, reaching the Twin Cities mid-late morning where they
should start to fizzle out. In the afternoon, 500-1000 j/kg of
mlCAPE will be enough to support scattered convection, again
with the greatest coverage over MN. A strong wind gust or two
could be possible, but severe risk looks better down in Iowa,
where the h7 and h5 wind speed maximums will be.
&&
.DISCUSSION...
Issued at 226 PM CDT Sun May 26 2024
Today`s rain has largely failed to materialized across the MPX CWA,
with only a couple hundredths of rain recorded through early this
afternoon, mainly over far eastern Minnesota and western Wisconsin.
A surface low centered over extreme northeast Iowa and its
associated cloud shield have led to a decent temperature spread with
upper 50s and low 60s under the cloud cover to low to mid 70s in
western Minnesota. Looking at satellite, a boundary is evident across
west central Minnesota up through the Arrowhead. A couple of
isolated showers may develop along this boundary through late this
afternoon, but the remaining rain chances area wide through this
evening are low. However, PoPs will ramp back up overnight with an
approaching shortwave through the day tomorrow. Some embedded
thunderstorms are possible during the late morning and afternoon
with the highest chance across southern Minnesota. Severe chances
are slim, but a few damaging wind gusts are possible with any
stronger storms. QPF totals will range from around a quarter to a
half inch through Monday evening.
Heading into Tuesday, a second shortwave will once again bring
shower chances to eastern Minnesota and western Wisconsin. Rainfall
amounts with this round will be very light before we dry out for mid
week. Temperatures will be on the cooler side Tuesday (low to mid
60s) and gradually warm into the mid to upper 70s for the remainder
of the period as a ridge builds in. The next chance for rain will
arrive Thursday afternoon with continued low PoPs into at least the
first half of the weekend. Minnesota and Wisconsin will end up on
the western periphery of the ridge Thursday through Saturday with
embedded shortwaves responsible for these continued chances.
&&
.AVIATION /18Z TAFS THROUGH 18Z TUESDAY/...
Issued at 550 PM CDT Sun May 26 2024
Any lingering clouds and rain are beginning to clear out this
evening across central Minnesota and western Wisconsin. All
sites should stay in VFR throughout the period, until our next
wave of rain approaches from the west overnight. Most of the
rain will fall as scattered light showers, with isolated
thunderstorms possible (30-50%) during the afternoon. Areas
further south, including KRWF and KMKT, look to have the best
environment for thunderstorm development. The biggest impact
from these storms will be strong gusts of wind and brief
visibility reductions. Any lingering showers will start to
weaken and clear out heading into the evening. Winds will be out
of the NE tonight, before shifting more N/NW by tomorrow
morning.
KMSP...Introduced the PROB30 for TSRA given the potential
(roughly 20-40%) for storm development during the afternoon.
Otherwise expect off and on light rain showers throughout much
of the day.
/OUTLOOK FOR KMSP/
TUE...VFR. Wind NW 10-15 kts.
WED...VFR. Wind variable 5 kts.
THU...VFR. Wind SE 10-15 kts.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...None.
WI...None.
&&
$$
UPDATE...MPG
DISCUSSION...Dye
AVIATION...BED
Area Forecast Discussion
National Weather Service Nashville TN
811 PM CDT Sun May 26 2024
...New UPDATE...
.UPDATE...
Issued at 740 PM CDT Sun May 26 2024
One final round of severe weather approaches this evening as a MCS
surges SE. Latest CAMs show a bowing line draping over Middle TN
after 02z tonight. The greatest threat with this line of storms
will be straight line winds and hail. That being said, models
continue to show favorable parameters for all severe hazards
tonight. The 00z balloon launch does show a strong cap, but
forcing from the line and moistening of the low levels should be
enough to erode away this cap. With already saturated soils,
flooding will also be a concern with any periods of prolonged
heavy rain. Storm will continue to work SE through the early
morning, exiting the Mid State by mid morning on Monday.
&&
.SHORT TERM...
(Rest of today through Monday)
Issued at 1224 PM CDT Sun May 26 2024
With convection moving across Upper Cumberland Region presently
and moving into northwestern portions of our area around
noontime hour, will continue with Tornado Watch across locations
around and north of I-40 Corridor through 3 PM CDT. When it comes
to latest CAMs, and let`s also throw in latest regional to global
models also, none of them are really doing a good job of
initializing and having a realistic weather pattern evolution
through afternoon hours today. Less cloud coverage noted across
locations south of I-40 Corridor and around and west of I-65
Corridor around noontime hour. Thus many quandaries abound as it
comes to weather pattern evolution as these afternoon hours
progress today. Another upper level shortwave passage is expected
to traverse mid state region this afternoon and that should at
least keep convection as a possibility for locations currently
under the Tornado Watch. Certainly, some of that convection could
be strong to severe, along with brief heavy rainfall potential,
especially in locations that did not experience the morning round
of convection or left over boundaries from this mornings
convection provide a focusing mechanism for convective
development as this afternoon progresses.
While there is much disagreement and uncertainty as it comes to
this afternoons forecast, there continues to be much better
agreement as tonight progresses. Of all models looked over around
noontime hour, best two seem to be a blend of most recent HRRR
model run and latest GFS model solution. Still looking for a
convective complex, MCS form, that may take on more of a linear
structure as nighttime hours progress, to drop down out of
southwestern Ohio River Valley Region/Western KY and into mid
state region generally during a 9 PM CDT to 4 AM CDT time frame.
In taking an average of these two preferred model solution
forecasted sounding profile and associated derived indicies, MU
CAPE values will be around 2,000 J/KG, BRN Shear values around
58m2/s2, right turning hodographs, mid level lapse rates around
7.5 C/km, SRH 0-1 KM & 0-3 KM 300m2/s2, DCAPE values around 1,000
J/KG, with PW values approaching 1.75 inches, and an older
indicies favorite of mine, Total Totals, ranging in the mid 50s
along with negative LI`s in higher negative single digit values.
All modes of severe weather hazards continue to be possible.
Latest SPC Day One Outlook has expanded their enhanced risk of
severe thunderstorm area to entire mid state region. Still however
believe that strong to damaging winds will be main weather hazard
that Middle Tennessee will possibly have to deal with, with large
hail and tornadoes secondary, but not by much. Continued flood
watch for entire mid state region through 7 AM CDT Monday morning
also per previous rounds of showers & thunderstorms that have
occurred and those that look like they are coming through this
afternoon and tonight.
Look for showers and thunderstorms to eventually exit the mid
state region by Monday afternoon.
&&
.LONG TERM...
(Monday Night through next Sunday)
Issued at 1224 PM CDT Sun May 26 2024
Not much change as it comes to forecast for rest of the week into
upcoming weekend. Dry conditions will finally prevail by Monday
night with a dry surface cold front dropping from north as
Tuesday progresses with broad surface high pressure influences
prevailing. Along with broad upper level troughing across most of
eastern CONUS providing northwesterly flow across our neck of the
woods through at least Thursday, a progression to cooler
temperatures will commence beginning on Monday night with lows by
Wednesday and Thursday Nights spanning the 50s, possibly upper 40s
Cumberland Plateau Region, with highs on Thursday only in the
upper 70s to lower 80s, mid 70s Cumberland Plateau Region. A
warmup will begin on Friday into first part of next weekend with
temperatures once again several degrees above seasonal normal
values as upper level ridging influences move across our area. As
surface and upper level ridging influences begin to shift
eastward, a more southerly low level atmospheric flow pattern will
develop supporting increased moisture advection across our area
that could result in shower and thunderstorm chances returning to
mid state region as Friday night through the upcoming weekend
progresses.
&&
.AVIATION...
(00Z TAFS)
Issued at 626 PM CDT Sun May 26 2024
We will get a break in the action for a few hours but a line of
strong thunderstorms will start to push into the northwest part of
the area after 03z. This line will continue to push east through
11z. IFR/LIFR is expected with the line of thunderstorms due to
low cigs, low vis, heavy rain, and possible gusty winds. MVFR cigs
will linger behind the line through at least 16z. A few scattered
showers will be possible once again tomorrow in eastern areas
after 16z. Southerly winds 10-15 knots shifting more westerly
overnight and northerly tomorrow.
&&
.PRELIMINARY POINT TEMPS/POPS...
Nashville 70 85 64 85 / 90 20 0 0
Clarksville 68 82 61 82 / 90 10 0 0
Crossville 63 78 56 77 / 90 50 10 10
Columbia 68 85 61 85 / 90 10 0 0
Cookeville 65 79 58 79 / 90 40 10 0
Jamestown 64 79 57 77 / 90 50 0 0
Lawrenceburg 68 85 61 84 / 90 20 0 0
Murfreesboro 68 85 60 85 / 90 20 0 0
Waverly 67 83 62 84 / 90 10 0 0
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
Flood Watch until 7 AM CDT Monday for Bedford-Cannon-Cheatham-
Clay-Coffee-Cumberland-Davidson-De Kalb-Dickson-Fentress-Giles-
Grundy-Hickman-Houston-Humphreys-Jackson-Lawrence-Lewis-Macon-
Marshall-Maury-Montgomery-Overton-Perry-Pickett-Putnam-Robertson-
Rutherford-Smith-Stewart-Sumner-Trousdale-Van Buren-Warren-Wayne-
White-Williamson-Wilson.
&&
$$
UPDATE.......Cravens
SHORT TERM...JB Wright
LONG TERM....JB Wright
AVIATION.....Mueller
Area Forecast Discussion
National Weather Service Raleigh NC
930 PM EDT Sun May 26 2024
.SYNOPSIS...
A cold front will approach late today and move through the region
Monday night. Dry high pressure will settle into the region toward
the middle of next week.
&&
.NEAR TERM /THROUGH TONIGHT/...
As of 930 PM Sunday...
The severe thunderstorm watch remains in effect until 11 PM for our
northwestern counties. Satellite and radar imagery reveals a well-
defined MCV northeast of Mount Airy over far south-central VA. As
such, the strongest storms are currently along and east of this
feature, stretching from the northeast/northwest Piedmont and
southwest to just northwest of Charlotte. Based on latest trends,
the main severe risk looks to be across the northern and northwest
Piedmont. However, a strong line also exists just northwest of
Stanly County and this is roughly moving ESE. Damaging straight line
winds appear the main risk into late this evening. As the late
evening wears on, it is difficult to say how the storms may hold
together as they track into the Triangle, Sandhills, and Coastal
Plain. Most CAMs have the storms either splitting to the north and
south of the Triangle, though this will be something to watch for.
Certainly convective inhibition will play a role as the night wears
on, limiting overall storm coverage. We do think that the storms
should start to dissipate after midnight as the MCV pushes to the
east. However, upstream convection currently over MO/IL/KY is
forecast to reach portions of the southern Appalachians by early Mon
and could reach the Triad toward sunrise, though convective
inhibition will keep most activity sub-severe until the better
chance comes Mon aftn/eve. Lows should dip into the mid 60s to
around 70, with some patchy fog possible.
&&
.SHORT TERM /MONDAY AND MONDAY NIGHT/...
As of 316 PM Sunday...
There is decently high uncertainty wrt to thunderstorms on Monday.
An upstream MCS is forecast to interact with the mountains early
Monday morning. Most guidance suggests the mountains should eat this
up before reaching our western areas. However, there is will still
likely be some ongoing showers (and perhaps a little thunder)
through about mid-morning across the western to central Piedmont
associated with this decaying MCS. Lingering cloudiness may persist
through late Monday morning, however clouds should clear enough in
the afternoon to support the development of scattered thunderstorms.
The spatial extent for afternoon showers/storms will largely depend
on 1) where outflow boundaries set up from the upstream morning
convection and 2) where mid-level vorticity/MCV features traverse.
The recent RAP runs suggest mid-level features could maximize along
and south of the NC/SC border Monday afternoon. It`s therefore not
surprising that latest HRRR runs tends to focus late afternoon
convection across our Sandhills/Southern Coastal Plains (and moreso
active in central SC). Additional weaker perturbations are depicted
further north into central VA maximizing over the Chesapeake Bay. As
such, some high-res guidance (eg. NamNest, ARW) depict a bit more
activity further north across our central to northern
Piedmont/Coastal Plain Monday afternoon associated with these
perturbations.
Any storms that do develop Monday afternoon will have increasing
effective shear to work with (up to 30 to 40 kts). As such, severe
thunderstorms will be possible with any stronger storms that fire. In
fact, guidance is pretty riled up about some stronger mid-level
lapse rates (~7.5 to 8 C/km) developing across our far southern
areas eastward towards the coast. Additionally, model-derived
hodographs, HREF max/min helicity neighborhood probabilities, and
model-derived STP values all support the potential for rotating
storms (and possible tornadoes) from roughly US-1 east across the
inner/outer banks Monday afternoon and evening. Given this
potentially juicy parameter space, it`s no shock that the SPC has
outlined our area in a 15% probability for severe hail and wind
(supported by strong mid-level lapse rate potential), with a smaller
area of up to 5 % probability for tornadoes across locations east of
Raleigh. The overall mean-layer flow should be strong enough to
preclude any widespread flooding concerns, however, can`t rule out
isolated urban flash flooding with any heavier downpour.
Rain chances should diminish late Monday night into the overnight
hours. Persistent swly flow will promote highs in the mid to upper
80s/lower 90s.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
As of 155 PM Sunday...
By Tuesday morning, a cold front should be along the coastline of
the Carolinas or immediately offshore. This should keep a slight
chance of thunderstorms in the forecast along the I-95 corridor, but
by nighttime, a several day period of dry weather should begin. The
front will slowly push east, and a surface high will establish
itself over southwestern Ontario Wednesday morning. The high will
expand to the southeast through the rest of the week, with the
center reaching West Virginia by Saturday morning. An upper ridge
along the East Coast will begin to break down on Saturday, and a
shortwave could bring some isolated showers across western counties
Saturday afternoon/evening, although this scenario is only shown in
ensembles and not by deterministic models. A stronger shortwave
appears likely to move across the Appalachian mountains Sunday and
bring a chance of showers to all locations. Surprisingly, the GFS is
showing a decent cap on Saturday and Sunday, so do not have
lightning in the weekend forecast.
Temperatures will trend downward through the beginning of the
period, with highs ranging from the mid 70s to the low 80s on
Friday. High temps will then rebound for the weekend, returning into
the 80s. Thursday and Friday nights will be the coolest, with
widespread lows in the 50s.
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
As of 734 PM Sunday...
Main forecast challenge in the near-term will be the threat of
showers and storms with upstream convection over western NC and VA.
The radar trends the last few hours have brought high confidence in
TSRA reaching GSO/INT, roughly between 00 and 02z, with lesser
confidence at RDU/FAY/RWI. As such, greatest restrictions are
expected at GSO/INT. Confidence remains low on how the storms
upstream will hold together as they track ESE toward RDU/FAY and
perhaps RWI as well. As such, the TEMPO groups were retained but for
the MVFR range. Shower/storm activity should wane after 05-06z as
the storm complex pushes east of the terminals. Guidance indicates a
low-end chance of sub-VFR stratus or low VIS at GSO/INT Mon morning.
Otherwise, another upstream MCS in the Midwest could bring -SHRA in
the morning on Mon, most favored at GSO/INT/RDU. A better chance of
storms appears in the aftn/eve period ahead of a cold front.
However, confidence is low on where storms may develop. Right now,
guidance would suggest the best chance would be along/east of US-1.
Hence, we introduced PROB30 groups at RDU/FAY/RWI. Ahead of any
storms, southwest winds Mon afternoon will gust to 25-30 kt.
Outlook: A broken line of showers and storms may impact the
terminals Mon evening, with the highest chance at RDU/FAY/RWI.
Activity should move out by early Tue, with VFR persisting much of
the upcoming week.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SYNOPSIS...Badgett
NEAR TERM...Kren
SHORT TERM...Luchetti
LONG TERM...Green
AVIATION...Kren