Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 06/03/24
Area Forecast Discussion
National Weather Service La Crosse WI
628 PM CDT Sun Jun 2 2024
.KEY MESSAGES...
- Another rounds of showers, a few storms overnight through Mon
morning (60-90% chances).
- Additional showers and storms (70-90% chance) will push
through the region Tuesday bringing additional rainfall
amounts around 0.5-1" with locally higher amounts. Isolated
severe storms will be possible, mainly earlier in the evening.
- Below normal temperatures are expected for the second half of
the week with occasional shower chances into the weekend.
&&
.DISCUSSION...
Issued at 235 PM CDT Sun Jun 2 2024
* SHOWERS, A FEW STORMS TONIGHT - severe storms not expected
First for this afternoon and early evening, a broken band of north-
south running convection continues to press east from western MN,
along a weak ripple in the upper level flow. CAMS models shift that
band into eastern portions of the Gopher state by late afternoon,
but it becomes more broken and more favored in the north, following
the more dominate upper level feature. It is also pushing out of the
ridge of higher instability while running into a drier near sfc
layer. May have a smattering of mid level showers make it into
southeast MN, but coverage it expected to be spotty at best, favored
by a bulk of the CAMS. Will hold low end (20%) chances for the
afternoon/early evening west of the Mississippi River.
Moving back to tonight, more bits of upper level energy progged to
shift east out of the northern plains while a mostly MCV derived
feature from convection over the central plains lifts northeast
overnight. The instability axis will also ease a bit east, but not
by much according to the RAP (holds the main pool centered over
western/central MN). Some elevated instability around 500 J/kg could
spark a few storms, mostly west of the Mississippi river. Meanwhile
the low level jet/moisture transport push northward across the local
forecast area overnight/Mon morning, with PWs of 1.5+" and warm
cloud depths flirting with 3500 m helping to fuel pcpn chances. Some
disjointness between the various short term guidance in how the two
perturbation come together (if at all) and the resulting spread of
showers/storms. The mixed bag keeps forecast confidence low with
how the radar reflectivity will look as the pcpn moves in overnight,
but high that most of the local will get wet. Will follow the blend
for chances, leaning into the CAMS for some details in timing.
Expect some refinement to these chances as we move into tonight.
Current trends shift the pcpn east/southeast by 17-18z and generally
dry after that. There have been hints that a linger west-east sfc
boundary could layup over northern IA, working on the instability
pool with some help from the low level jet to trigger a thin line of
convection for the afternoon. Not a lot of support at this time, but
worth monitoring.
* TUESDAY/TUESDAY NIGHT: Warmer with Showers and Storms, Isolated
Severe Potential with Locally Heavier Rainfall
As we head into Tuesday, a deepening 500mb trough will eject
from the Rockies into the Northern Plains with a developing
surface cold front situated along the exit region of the
aforementioned trough. Ahead of this trough, fairly robust
southerly surface flow will allow for some moisture advection
into our region with precipitable waters in the 02.12z NAM/GFS
reaching to around 1.75", well above the 90th percentile for
KDVN sounding climo. Consequently, with this warm and moisture
rich airmass being pushed into our region, expecting
temperatures to warm well into the 80s with corresponding
dewpoints into the middle and upper 60s. Exactly how warm we get
will largely depend on a weak warm front noted with some subtle
theta-e advection shown in the 02.12z NAM during the late
morning and into the afternoon in addition to how any cumulus
deck and diurnal mixing plays out as well. There is some
potential this weak boundary could initiate shower activity
along it during the late morning and into the afternoon, however
guidance is a bit spotty in how this resolves. As a result,
kept with lower precipitation chances for now during this
period.
Eventually, the cold front approaches the region and convection will
spread into the local area from west to east during the evening
hours. Instability profiles shown during this period generally begin
to wane through the evening, however will have a reasonable amount
to work with initially as the 02.12 NAM/GFS show values of MLCAPE
approaching 1500-2000 J/kg by 7pm before diminishing rapidly as
convection pushes eastward towards midnight. Additionally, shear
profiles still appear fairly lackluster for any organized severe
threat with much of the more favorable bulk shear maintaining behind
the boundary. As a result, could end up having evening convection
manifesting as pulse thunderstorms that may produce some large hail
(up to quarter sized) earlier in the evening, before quickly turning
more into non-severe linear convection. Additionally, not overly
impressed with the low and mid-level wind profiles, reaching
only to around 25-40 kts, suggesting maybe you squeak out a
couple 40-50 mph gusts. Consequently, the SPC has a marginal
risk (Threat level 1 of 5) for the western two-thirds of the
local area for Tuesday.
Regardless of severe threat, there will likely be some healthy
rainfall totals with this system as well albeit expecting a fairly
progressive motion with these storms. Currently, ensemble guidance
in the 02.12z GEFS/EC ensemble, favors respectable probabilities (40-
70% chance) for over 0.5" of precipitation with the Tuesday round of
storms with localized amounts of up to an inch not completely out of
the question (10-30% chance) when considering the aforementioned
higher precipitable waters and deeper warm cloud depths (around
3.5km). When combined with the prior precipitation, this could
certainly result in widespread around 1" totals with locally
higher amounts from now through Tuesday night which could create
some river rises in areas that are already susceptible.
* WEDNESDAY INTO NEXT WEEKEND: Relatively Cooler Pattern
The second half of this week will feature a broad synoptic trough
that will entrench itself over the eastern half of the CONUS
subjecting our region to a general north/northwesterly upper-level
flow pattern. Consequently, expecting temperatures to trend below
normal into the weekend with the 02.00z grand ensemble (GEFS/EC
ens/Canadian ens) keeping median high temperatures in the lower to
middle 70s at La Crosse beginning Thursday. Keeping with lower end
precipitation chances into the weekend in accordance with the NBM to
account for the shower potential consistent with this type of
synoptic pattern.
&&
.AVIATION /00Z TAFS THROUGH 00Z TUESDAY/...
Issued at 628 PM CDT Sun Jun 2 2024
Main taf concerns are MVFR conditions along with showers/storms
tonight into Monday morning. Expect showers/storms to move
across the area along a surface cold front and to impact the taf
sites after 06z Monday. MVFR conditions are expected with the
convection. There are hints of a brief period of IFR conditions
with the stronger showers or storms. Though...will continue
with the MVFR conditions at both RST/LSE taf sites for now.
Conditions will improve to VFR after 18z Monday at both taf
sites. Latest model trends show instability across the region
tonight/Monday morning. Will introduce a period of when the most
likely time thunder could occur at the taf sites.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
IA...None.
&&
$$
DISCUSSION...Naylor/Rieck
AVIATION...DTJ
Area Forecast Discussion
National Weather Service Charleston SC
1005 PM EDT Sun Jun 2 2024
.SYNOPSIS...
High pressure will extend across the area through Wednesday. A
cold front will slowly move through on Friday, followed by high
pressure.
&&
.NEAR TERM /THROUGH MONDAY/...
The axis of a broad mid-level trough will remain over the
forecast area tonight. Deep moisture associated with the trough
should remain just west of the region. Late this evening, KCLX
detected a few weak showers over the Midlands of SC, dry across
SE GA and SC. Recent runs of the HRRR indicates generally dry
conditions across the land and water zones tonight. The updated
forecast will remove SCHC PoPs over the marine zones. Otherwise,
conditions should remain dry with plenty of mid and high
clouds. Low temperatures are forecast to range from the mid 60s
inland to the around 70 along the coast.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
Monday: Weak ridging will be situated aloft, with a subtle short
wave to pass near the Santee River in the afternoon. At the surface,
high pressure is the main feature, although there might be the
development of a weak lee side trough. There isn`t as much of a cap
per sounding data, so we will be able to some convection across the
region. Lapse rates are only so-so, and MUCAPE is forecast to reach
1000-1500 J/kg. But given the sea breeze becoming more active, and
upstream convection due to diurnal heating and the lee trough will
produce scattered showers and t-storms. The greatest chances (50%
PoPs) are near and west of I-95 in the afternoon when buoyancy is
the best. Since DCAPE is in excess of 1000 J/kg and sounding do show
an inverted-V trace, there would be a risk for some strong wind
gusts where boundary interactions occur. Thus the severe risk is non-
zero. The HREF does show a 50% potential for more than 1 inch of
rain late in the afternoon near and west of I-95. But other guidance
has much less probabilities of that happening. 850 mb temperatures
reach 15-16C, and will support max temperatures prior to convection
hitting the mid and upper 80s. Evening convection quickly diminishes
far inland, and the rest of Monday night looks to be rainfree.
Although winds do decouple, a south-southwest synoptic flow and
higher dew points will limit lows to just 66-70F inland, several
degrees warmer at and closer to the coast.
Tuesday: Ridging prevails aloft and the capping is better than on
Monday. As a result we hold PoPs down to just 20/30%, driven mainly
by the sea breeze and any mesoscale boundary interactions. DCAPE is
again favorable for strong wind gusts in a few storms, but given
poor lapse rates, the potential is less than on Monday. 850 mb
temperatures climb about another 1C, leading to highs making it to
the upper 80s and near 90F.
Wednesday: Surface ridging is a bit weaker, while aloft the flow
becomes more zonal. There is also a short wave that is progged to
move through, and with greater MUCAPE and slightly better lapse
rates, this will lead to a higher chance of convection, as we show
up to 50% probabilities. Temperatures aren`t much different than
Tuesday, with the slightly higher 850 mb temperatures negated by the
higher rain chances.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
An anomalous upper low digs through the Great Lakes region Thursday
and Friday, then into the Northeast and Mid-Atlantic vicinity during
the weekend. That upper air pattern will likely send a cold front
toward us late in the week, with model consensus showing that the
cold front does indeed make it through for the weekend. That`s
difficult to do this time of year, but guidance has been consistent
on that happening, so we maintain that forecast. There is a decent
short wave that passes through Thursday, leading to at least
scattered coverage, then less activity with the approaching front
Friday due to better capping, and then little to no chance for
Saturday and Sunday if there actually is the passage of the cold
front prior to then. Every day will be well above climo, mainly in
the lower to perhaps mid 90s, the combination of warm advection and
compressional heating in advance of the cold front, the due to an
offshore flow in its wake. Some heat indices will be near or above
100F Thursday and Friday, but not enough for any Heat
Advisories.
&&
.AVIATION /02Z MONDAY THROUGH FRIDAY/...
VFR conditions will prevail at KCHS, KJZI, and KSAV through 0z
Tuesday. Showers may develop near KSAV Monday afternoon. The
KSAV TAF will feature the mention of VCSH starting at 19Z.
Extended Aviation Outlook: Outside of any convection, conditions
will be VFR through the period.
&&
.MARINE...
Tonight: SE to SSE flow will prevail across the local waters,
with speeds mostly in the 10-15 knot range. The strongest winds
will likely be along the land/sea interface through early
evening and gusts up to around 20 knots will be possible. Seas
will average 2-3 feet.
Monday through Friday night: High pressure is the main weather
feature through the week, until a cold front approaches late in the
period. Winds will be mainly S or SW at 15 kt or less the entire
time, with seas no more than 2 or 3 feet. Of course in any
convection the winds and seas can be briefly higher. We`re into the
early part of our local waterspout season, so this will be something
that we`ll need to starting watching for.
&&
.TIDES/COASTAL FLOODING...
Due to tides running as much as 0.3 to 0.5 ft MLLW above
predicted astro tide levels, and increasing astronomical
influences, there is the risk for minor coastal flooding
starting Monday evening. The risk is greatest over coastal
sections of Charleston and Colleton County through the week. The
latest TWL forecast for Charleston Harbor shows 7.0 ft MLLW
Monday evening, 7.1 ft MLLW Tuesday evening, and 7.3 ft MLLW
Wednesday evening. As a result, Coastal Flood Advisories are
likely. The highest during that time at Fort Pulaski is 9.3 ft
MLLW Wednesday evening.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...None.
SC...None.
MARINE...None.
&&
$$
NEAR TERM...NED
SHORT TERM...
LONG TERM...
AVIATION...NED
MARINE...Adam
Area Forecast Discussion
National Weather Service Dodge City KS
1047 PM CDT Sun Jun 2 2024
...Updated Aviation/Key Messages...
.KEY MESSAGES...
- Typical early summer weather for the next several days, with
seasonably hot afternoons and little chance of rainfall.
&&
.UPDATE...
Issued at 850 PM CDT Sun Jun 2 2024
Linear outflow dominated thunderstorm complex is dissipating in
response to strong capping at 700 mb (14C on 00z DDC sounding).
With moist southeast winds ahead of the outflow boundary,
continued attempts at weak convection are possible, but the
threat of severe wind/hail has been reduced to near zero. Will
monitor for convection over the southeast counties through early
morning. After coordination with SPC, cancelled severe
thunderstorm watch #376 for all of SW KS.
&&
.SHORT TERM /THROUGH MONDAY/...
Issued at 222 PM CDT Sun Jun 2 2024
The atmosphere has been fairly worked over early this
afternoon in the wake of the morning storms. This is
particularly true for the central and eastern zones of the FA.
This does introduce some uncertainty in the forecast as far as
storm redevelopment goes. For example, the 3 km NAM has storms
developing, but quickly kills this activity as the storms heads
east towards the more stable air. This cam solution is different
than the HRRR and ARW. These two models reload the atmosphere
with 3000 J/kg of CAPE redeveloping across the western zones by
late afternoon. Examining surface dewpoints does show 60+
dewpoints advecting in, so am tempted to go with the solution
that shows another severe thunderstorm complex rolling across
the Kansas plains late this afternoon and into the mid evening
hours. Storms should develop along a lee trough late this
afternoon either along the Colorado border or just east of it.
This activity should then head east and be along the Highway 283
corridor by mid evening. As far as threats are concerned, the
primary threat is damaging winds of 60 to 80 mph. 1-3" hail is
also possible if there are supercell structures. Bulk shear
though is more marginal today, so think the primary threat would
be the microbursts. Activity should be diurnally driven with a
possible weakening trend as this activity heads east of Highway
283 to the far eastern zones late this evening. Otherwise, lows
tonight will be seasonal with values in the 50s and 60s. A more
quiet day is expected Monday. If there were to be any storms, it
would be relegated to the eastern zones and only slight pops at
that. Otherwise, highs will be seasonal with values in the
upper 80s to lower 90s.
&&
.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
Issued at 222 PM CDT Sun Jun 2 2024
EPS has a 500-hPa ridge developing across the spine of the
southern Rockies Wednesday and Thursday. This building ridge is
also reflected in EPS probabilities of +90F in the 50% to 70%
range midweek. The long and short of it is that a return to
summer-like weather is expected midweek with generally dry
conditions and hotter highs. Now how long these warmer
temperatures will last is in question as EPS flattens the ridge
next weekend. Several of the EC ensemble members show returning
storm chances next weekend. At this point, will just go with the
NBM solution due to the uncertainty. That has pops in the 15%
to 30% range by the end of the period. A general decrease in
temperatures may be possible with storms around, although that
is not 100% certain as some of the EC ensemble members are dry.
Will watch for now and look for any particular trends in the
ensembles as time goes forward in future runs.
&&
.AVIATION /06Z TAFS THROUGH 06Z TUESDAY/...
Issued at 1047 PM CDT Sun Jun 2 2024
Thunderstorms have failed to maintain this evening, and
remainder of the night is expected to remain dry as convective
debris diminishes. Consensus of short term models suggests MVFR
stratus may develop through 12z Mon southeast of DDC. Otherwise,
good flying weather is expected through Monday, with VFR/SKC and
much lighter winds compared to Sunday.
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
UPDATE...Turner
SHORT TERM...Sugden
LONG TERM...Sugden
AVIATION...Turner
Area Forecast Discussion
National Weather Service Des Moines IA
632 PM CDT Sun Jun 2 2024
...Updated for the 00z Aviation Discussion...
.KEY MESSAGES...
- Thunderstorm chances through Tuesday. Confidence in details
and severe potential is low however, especially tonight
through Monday night.
- Little or no precipitation Wed-Sun with seasonal temperatures
and lower humidities
&&
.DISCUSSION...
Issued at 241 PM CDT Sun Jun 2 2024
Our pattern will undergo a fairly significant change through
the period transitioning from one that remains active with lower
amplitude flow, to one less progressive with much higher
amplitude as a large eastern CONUS closed low and corresponding
western ridge keep a drier regime in place for at least several
days. The current scenario at mid afternoon is largely
inactive, but recent satellite imagery continues to suggest some
large scale ascent is still present from lingering synoptic
short waves and remnant MCVs, one of which is vaguely noted over
the DSM metro. Several CAMs and thus the 12z HREF are fairly
emphatic that peak heating development will occur soon across
the NW Iowa and the Siouxland area, although there doesn`t
appear to be much of a focus for initiation beyond the
aforementioned mid level triggers from overnight convection.
There is little noted with regard to surface features, and
recent HRRR runs have been more tranquil in those areas, so
confidence in that occurrence is diminishing, as is confidence
overall. Several missing RAOBs upstream across central and
southern Plains were missing model ingest with 12z launches
omitted (LBF/TOP/DDC/AMA/DNR). Recent RAP/HRRR runs have placed
less emphasis on the NE/KS wind potential, and its remnants
into IA overnight, and more emphasis into a MN MCS, which may
fit trends as RAP 0-2km moisture convergence trends shifts from
the Siouxland area northward. Convective trends still remain
uncertain though with lingering larger scale vertical motion
still drifting through the MO Valley in a low CINH ~1000 J/kg
MLCAPE regime across IA, and effective shear +/- 30kts. Thus the
HREF members increasing convection central/NW later this
afternoon and evening cant be discounted, with broad-brush
chance PoPs until increasing overnight when upstream convection
may still reach the state, or drop southward from MN.
Moving into tomorrow, behind whatever occurs overnight, there
isn`t much in the way of low level focus or baroclinicity with
Iowa in the generalized warm sector. Some chances will still
linger Monday and Monday night with weak waves continuing to
traverse the developing southwest flow aloft ahead of the
maturing northern Plains upper level trough. This changes by
Tuesday however with much higher confidence in evolution, as the
model signal has been fairly consistent over the past few days
with phased large scale support and low level convergence along
the associated surface front later in the day. Although recent
GFS and EC deterministic runs have depicted weak 0-6km shear
ahead of the boundary, seasonal instability of 1000-2000 J/kg
MLCAPEs should be in place still suggesting at least some severe
potential with a disorganized wind/microburst environment the
most likely concern. Recent GEFS/EC ensemble specific humidity
and precipitable water values are anomalously high for early
June too suggesting some heavy rain potential. Corresponding
recent deterministic runs also continue to reflect healthy 1-2"
amounts in or near Iowa with the system passage.
A pattern change can then be anticipated for the remainder of
the week and through next weekend. Persistent northwest flow
aloft will result in little if any precipitation chances with
minimal moisture or forcing. A few weak waves traversing the
flow could result in brief and infrequent light precip through
the Upper MS Valley at times, and the baroclinic zone through
the Plains may be active at times, but generally removed from IA
with little anticipated in between. Although temperatures
should remain at seasonal levels, northwest flow both aloft and
at low levels should keep dewpoints seasonally low with readings
no better than the 50s as the stagnant pattern keeps surface
high pressure no further east than the MO Valley.
&&
.AVIATION /00Z TAFS THROUGH 00Z MONDAY/...
Issued at 632 PM CDT Sun Jun 2 2024
VFR conditions will prevail for much of the 00Z TAF period, with
two exceptions. First, a period of scattered to numerous
thunderstorms is forecast overnight into early Monday morning,
moving eastward primarily between about 06Z and 12Z at the
terminals. Intermittent MVFR or lower conditions are expected in
and around the thunderstorms, however, confidence in timing and
coverage is too low to justify TEMPO or prevailing groups at
this time and have handled with VCTS for now, expecting
refinement of details in later updates. Also, there may be a
period of prevailing MVFR ceilings around sunrise Monday, mainly
around MCW and have included those in the outgoing TAFs.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...None.
&&
$$
DISCUSSION...Small
AVIATION...Lee
Area Forecast Discussion
National Weather Service Goodland KS
921 PM MDT Sun Jun 2 2024
.KEY MESSAGES...
- Conditional chance of severe hail east of Highway 25 in Kansas
Monday afternoon.
- A less active weather pattern develops Tuesday through Friday
with above normal high temperatures in the 80s and 90s.
&&
.SHORT TERM /THROUGH TUESDAY NIGHT/...
Issued at 105 PM MDT Sun Jun 2 2024
Outflow boundary emanating to the west from earlier day convection
is currently the main mesoscale feature that may help make or break
today`s severe weather potential. The overall magnitude of the
severe threat for today remains rather conditional; but still
remains the potential for significant severe weather to occur.
Dryline thus far has moved very little with majority of the area
remaining in southerly flow with gusty winds helping keep the
moisture in place. With the moisture remaining in place; have
lowered temperatures into the mid to upper 80s from the
previous forecast, which may still be to generous given
anticipated cumulus field development and more stable air
behind the westward propagating outflow boundary.
All of this does play a role into thunderstorm development as well
as RAP soundings do show a CAP in place with convective temperatures
in the low 90s. There is also concern for dry air aloft moving into
the area which would hinder intensification of any updrafts due to
entrainment. Outflow as well will play a role into whether or not
specific areas will see initial storm development if it continues to
push west, however if it stalls then this may help enhance
additional lift and make convective initiation a bit more than a
single cell.
With all of this said, there may be 3 potential scenarios that will
play out:
1) Outflow continues to trek west stabilizing the environment
for the afternoon storm threat, would then have to watch for
northern areas for clusters moving SSE from the Nebraska
Panhandle.
2) Outflow stalls, but dry air entrainment "chokes off" updrafts and
helps keep the CAP in place; but still have the Nebraska Panhandle
storms move into the area.
3) Dry air is slower to move into the area, outflow stalls and
initial cells are more widespread/intense; then round 2 with the
Nebraska Panhandle activity.
As for hazards, with the (potential) afternoon storms. These should
remain more isolated with supercell potential initially producing
very large hail up to Tennis Balls, damaging wind gusts and
potentially tornadoes especially if a storm interacts with the
outflow boundary or if multiple cells are present through storm
mergers. At 18Z, the KGLD VAD wind profile does support this
potential with 0-3 SRH of 180 and 0-1 SRH of 100 m2/s2. With the
anticipation of this increasing especially near the outflow
boundary and as the main shortwave approaches. At this time the
area of potential greater tornado threat looks to lie west of
Highway 25 but north of I-70 (Yuma, Dundy, Cheyenne (KS),
Rawlins, Thomas and Kit Carson counties).
For the potential for activity moving in from the Nebraska Panhandle
after sunset. At this time thinking that this should favor more of
the northeast counties (Hitchcock, Red Willow, Norton, Decatur).
This looks to be mainly a damaging wind threat with 70+ mph wind
gusts possible and heavy rainfall, which may exacerbate and
flooding issues from the past several days of heavy rainfall.
Will also have to monitor for potential redevelopment across the
area overnight as a cold front sags through the area and interacts
with the LLJ; at this time not anticipating this to be severe
but only a heavy rain potential. Due to uncertainty regarding
this afternoons mesoscale features and potential "interruptions"
to the environment will keep this as slight chance pops for
now.
Monday, zonal upper level flow looks to be in place. Some surface
convergence during the afternoon hours may bring some additional
thunderstorm development primarily east of Highway 25. Due to
lack of upper level support thinking is that this shouldn`t be
along lived event like today. Some severe threat may be present
with moisture remaining in place MUCAPE in excess of 3500 j/kg
and wind shear of 25-30 knots. Highs for tomorrow look to be in
the mid to upper 80s but with less wind as wind should remain
mainly light and variable. Another wave then moves across the
area Monday night and into Tuesday morning bringing another
round of thunderstorms; severe weather is not anticipated at
this time with that activity.
Split flow, then dominates the area Tuesday as temperatures
again rise into the 80s for all of the area. Not currently
seeing any signs for precipitation. Winds will become breezy
from the NW around 20 mph gusting 30-35 mph.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
Issued at 1230 PM MDT Sun Jun 2 2024
Wednesday...500mb heights slowly rise as upper level ridging
strengthens over the western half of the country. There is a hint of
moisture in the 700-500mb layer moving through the area from the
north during the day along or immediately behind some cooler air and
wind shift. Not much instability to work with and old school Totals
Totals only in the lower 40s and K Index values 20-25 dont generally
support any convection. Presently, the forecast is dry and thats
seems reasonable this moment. 850mb temperatures in the 25C to 32C
range support high temperatures in the 90s. Low temperatures are
forecast to be in the 50s to lower 60s.
Thursday...not a whole lot of change in the 500mb pattern. Daytime
hours look to be precipitation free with a 20% chance for showers
and thunderstorms to develop during the night as 850-500mb moisture
increases from the southeast while weather disturbances move east
off the Palmer Divide and Cheyenne Ridges and into our area. 850mb
temperatures are a little cooler, ranging from 19C to 27C. This
would typically support high temperatures in the 80s. Low
temperatures are forecast to be in the 50s.
Friday...the tongue of better moisture in the 850-500mb layer over
much of the area in the morning slowly moves east through the
morning and out of the area by late afternoon with associated 20%
pops with it. The next weather system per 700-500mb relative
humidity forecasts emerges off the Colorado front range and
potentially into far eastern Colorado by 00z Saturday, moving
across the remainder of the area during the night with 30%-40%
chances of showers and thunderstorms with it. High temperatures
remain above normal in the 80s to around 90 with low
temperatures in the 50s.
Saturday...generally speaking, any mornings showers across the
eastern half of the area should move out as the next weather system
moves off the Colorado front range and into perhaps far eastern
Colorado by the end of the day, continuing east across the entire
area during the night in some form or fashion. Presently, 20% pops
are forecast in the morning with 40% chances across far eastern
Colorado late afternoon and 40%-50% chances for showers and
thunderstorms during the night. High temperatures are forecast to be
in the 80 to 85 degree range with low temperatures in the 50s.
Sunday...similar large scale scenario as Saturday with any morning
showers/thunderstorms exiting in by late morning/early afternoon
then waiting for next wave to move across from eastern Colorado
during the night. Presently, 20%-40% chances for thunderstorms
during the day, 30%-50% during the night. High temperatures cool a
bit into the upper 70s to lower 80s with low temperatures in the
50s.
&&
.AVIATION /00Z TAFS THROUGH 00Z MONDAY/...
Issued at 512 PM MDT Sun Jun 2 2024
Scattered thunderstorms this evening may briefly impact either
KGLD or KMCK with gusty winds and reductions in visibility in
rain through about 04z before moving east. Overnight, some
patchy fog possible towards sunrise but confidence is on the low
side. If fog does form, it should dissipate by mid morning. Only
isolated thunderstorms are expected Monday afternoon.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...None.
CO...None.
NE...None.
&&
$$
SHORT TERM...Trigg
LONG TERM...99
AVIATION...024
Area Forecast Discussion...UPDATED
National Weather Service Jackson MS
727 PM CDT Sun Jun 2 2024
...New MESOSCALE UPDATE, AVIATION...
.MESOSCALE UPDATE...
Issued at 709 PM CDT Sun Jun 2 2024
In strong contrast to most deterministic guidance, an MCS has
taken shape and is maintaining itself well as it pushes east
across Northeast Texas as of 7 PM. Additionally, some sea breeze
convection is continuing along a line from Corsicana, TX
southeastward to the Lake Charles, LA area. The air mass north of
the sea breeze and east of the advancing MCS is marked by MLCAPE
of 2000-3000 J/kg and a Lifted Index of -8 to -10. A gradient of
PWAT is aligned parallel to the mid-level flow and deep-layer wind
shear (though flow is modest). Based on radar presentation and
anticipating cold pool dynamics to sustain an east-southeast
momentum for the MCS, have at least increased our POPs around
midnight tonight into the early morning into the "chance" range.
Short-term high-res models are struggling to capture the situation
with any more confidence, but latest few runs of the HRRR seem to
be reasonable with the general idea. As was the case last evening,
the MCS may be choked off of instability or start to compete with
the lingering sea breeze convection as the two areas interact.
That might limit the farther eastward extent, but will continue to
monitor the trends this evening. If storms do reach our area with
some organization, a damaging wind threat and heavy rainfall are
possible especially in northeast/central LA and southwest MS. /NF/
&&
.DISCUSSION...
Issued at 325 PM CDT Sun Jun 2 2024
Monday:
The active weather period will pick back up on Monday as
shower/thunderstorm chances return across the CWA. Another
shortwave disturbance from central TX is expected to push eastward
towards our area. As the shortwave approaches, model guidance is
suggesting that a MCV will approach the ArkLaMiss area in the
afternoon and evening hours and help to initiate storms. With
dewpoints in the 70s, decent instability, and lapse rates, some
storms could be strong to severe. A "Marginal" risk for severe
weather was expanded to include areas west of I-55. High
temperatures in the upper 80s to near 90 degrees are expected.
/SW/
Monday night through Saturday night: An active weather pattern
will continue through most of the upcoming week with perturbed
westerlies having the greatest influence on our forecast. As has
been the case recently, mid level flow will be more than
sufficient for organized convective systems, and moisture/instability
will occasionally support damaging wind and heavy rainfall
threats.
The biggest challenge will be forecasting the timing of any
systems, and it continues to look like the mid to late week time
frame will be the primary focus for a more significant convective
system to impact the area. With the upper level pattern becoming
more northwesterly and cyclonic, a cold front is expected to
approach the area Wednesday as a stronger perturbation crosses
the forecast area. Cold air aloft combined with a hot and humid
boundary layer will provide a favorable environment for strong to
severe convective wind during peak heating, so we`ll be monitoring
for potential convective systems and ramp up the messaging as
confidence increases. It seems late Wed/Thu/early Fri are when
the global models show the strongest convective signals.
Thereafter, guidance is bouncing around a good bit between
different solutions with some showing drier while others keep it
more warm and humid, and perhaps active in terms of convection
into the weekend. /EC/
.AVIATION...
(00Z TAFS)
Issued at 709 PM CDT Sun Jun 2 2024
Confidence on coverage and timing of SHRA or TSRA activity
throughout he period is too low to include in the TAFs at this
time for most sites, however typical seasonal pattern of
increasing chances during the 18Z Monday to 00Z Tuesday time frame
is expected somewhere in the forecast area. Will update TAFs with
timing or impacts as confidence increases. Otherwise, some low
stratus or patchy BR could produce MVFR conditions at a few sites
between the 09Z to 15Z Monday time frame. /NF/
&&
.PRELIMINARY POINT TEMPS/POPS...
Jackson 68 88 71 90 / 10 30 30 30
Meridian 67 89 70 90 / 10 30 20 40
Vicksburg 70 89 73 90 / 20 30 40 20
Hattiesburg 69 90 72 91 / 10 50 40 30
Natchez 69 88 71 90 / 30 50 40 20
Greenville 71 89 74 90 / 10 30 40 20
Greenwood 69 90 73 90 / 0 20 30 30
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...None.
LA...None.
AR...None.
&&
$$
SW/EC/NF
Area Forecast Discussion
National Weather Service Memphis TN
908 PM CDT Sun Jun 2 2024
...New UPDATE...
.UPDATE...
Issued at 908 PM CDT Sun Jun 2 2024
A few isolated showers will remain possible in portions of
northeast Mississippi over the next hour or two. By midnight, dry
conditions will prevail with patchy fog possible near the
Tennessee River.
Shower and thunderstorm chances will increase on Monday as an
upper level low, embedded in a shortwave trough, treks across the
Mid-South. The severe weather threat with these storms will be
hampered by lack luster shear values. However, SBCAPE on the
order of 3000 J/kg and low level lapse rates around 7.0 C/km will
support a Marginal Risk for severe storms with damaging winds and
large hail the primary concerns.
One interesting thing to note: The 00Z HRRR depicts a much more
organized line of storms pushing across Arkansas towards the
Mississippi Delta by early evening. If this solution materializes,
a greater severe weather threat may emerge. Updates regarding this
system will come as more data becomes available.
ANS
&&
.SYNOPSIS...
Issued at 310 PM CDT Sun Jun 2 2024
Warm and humid conditions will continue through mid-week. Several
upper level disturbances will keep shower and thunderstorm chances
in the forecast through Wednesday. There exists a potential for
strong to severe thunderstorm development along and west of the
Mississippi River tomorrow afternoon through evening with primary
threats of damaging winds and locally heavy rainfall. A weak cold
front will move through Thursday decreasing our rain chances and
cooling temperatures slightly.
&&
.DISCUSSION...
(This evening through next Saturday)
Issued at 310 PM CDT Sun Jun 2 2024
Weak upper level ridging continues to dominate the region leading to
a relatively dry day across the Mid-South. Upper level water vapor
imagery currently denotes a shortwave over northern Mississippi
where a few clusters of pop-up convection continue to form along. 20-
25% PoPs were held over northeast Mississippi through late this
evening to cover this continued pop-up convection. Upper ridging has
created a pretty warm, early June day with current temperatures in
the mid to upper 80s with light, variable surface winds. As light
to eventual calm surface winds remain across the Mid-South under
a thin cirrus deck, fog is likely to develop along the Tennessee
River, spreading east. Fog and reduced visibilities tonight do not
look as widespread as last night as the aforementioned cloud
cover will likely diminish widespread coverage.
Come tomorrow afternoon, shower and thunderstorm chances will
begin to increase in areas along and west of the Mississippi River
as an upper level trough and associated upper level low rotate in
over the Upper Mississippi Valley. Several shortwaves will eject
from this upper low leading to increased lift for possible strong
to severe thunderstorms tomorrow afternoon and evening. Grand
Ensemble members have a >60% chance of surface based CAPE >1500
J/kg and about a 30% chance of 0-6km bulk shear >30 kts over this
same area. Bottom line, there exists a conditional chance for
severe weather tomorrow afternoon and evening. Primary threats,
if any, will be damaging winds and localized heavy rainfall.
PWATs surge near the 90th percentile Tuesday and into Wednesday
as what looks like a few MCVs move across the area along decent
height falls and several shortwaves ejecting from the west.
Dewpoints also edge up into the mid 70s Wednesday morning into
afternoon leading to ample moisture availability in support of
continued showers and thunderstorms. Greatest rainfall amounts of
up to 2" will fall over northeast Arkansas and the Missouri
Bootheel through Thursday morning.
A low pressure system will push east and set up along the Great
Lakes and Canada border with an attendant, weak cold front. This
front will begin pushing across the Mid-South Thursday afternoon.
Shower and thunderstorm chances will diminish by Thursday evening
as mostly dry conditions continue through next weekend.
Temperatures will also decrease slightly behind this
aforementioned front with daily highs in the mid to upper 80s.
Daily high temperatures ahead of this front will be in the upper
80s to lower 90s. Good news, the CPC 8-10 day temperature outlook
has us slightly below normal heading into mid June.
AEH
&&
.AVIATION...
(00Z TAFS)
Issued at 611 PM CDT Sun Jun 2 2024
Both weak ridging aloft and weak surface high pressure should keep
us mostly VFR over the next 24-30 hour TAF cycles. However, patchy
MVFR fog is possible late tonight near TUP. Scattered
thunderstorms may impact JBR and MEM tomorrow afternoon resulting
in brief MVFR(or lower) conditions due to diminished VIS and brief
gusty winds. Prevailing wind will be light and variable tonight
and from the south to southwest tomorrow, generally 5-10kts. A
higher chance of storms will begin near MKL and TUP after 00Z
tomorrow.
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...None.
MO...None.
MS...None.
TN...None.
&&
$$
PUBLIC FORECAST...AEH
AVIATION...JDS
Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
729 PM CDT Sun Jun 2 2024
.KEY MESSAGES...
- Thunderstorms, a few with severe weather and localized heavy
rain possible this evening, especially across western and
central Minnesota.
- Another chance for widespread rain and potentially severe thunderstorms
is likely Tuesday.
- Pleasant, mainly dry weather, and breezy weather expected
Wednesday into next weekend.
&&
.DISCUSSION...
Issued at 316 PM CDT Sun Jun 2 2024
With a broad shortwave moving across the northern Plains, we`ve seen
southerly h85 winds and associated moisture transport increase
across MN out ahead of that shortwave. This isentropic lift and
moisture transport has resulted in the showers that we saw come out
of eastern SoDak early this afternoon. SPC mesoanalysis at 18z
showed a pocket of 1000+ j/kg of mlCAPE had developed down by St.
James and as soon as this area of showers got to the north of St.
James, a quick uptick in radar reflectivities was noted near Redwood
Falls. With SSE low level flow, this instability won`t make much
progress east, so the intensity of returns we`re seeing back west of
New Ulm at 230pm are not expected to maintain their intensity into
the Twin Cities as they run away from the instability.
For the rest of tonight, there are a couple of things to watch.
First, we`ve seen storms expand across NoDak, this has been the
region of QLCS generation we`ve been worried about the past couple
of days. The other concern we`ve been seeing from the last few runs
of the HRRR and its the potential for the development of scattered
storms this afternoon in eastern SoDak/western MN. Basically, the
HRRR is developing convection on the northeast fringe of the strong
pool of instability over south central SoDak (expected to build to
over 4000 j/kg of mlCAPE). The HRRR has been generating some updraft
helicity tracks with this activity, indicating the potential for
some supercell structures. This potential for more convection to
fire ahead of the NoDak activity has only led to more uncertainty on
how those storms will evolve through the night. The main trend we`ve
seen with the potential for any lines of storms tonight is less
organization. The biggest impact from the lack of organization is we
saw our QPF from WPC take a pretty good hit for tonight. Though
severe probabilities from the SPC have not changed through the day,
given less organization expected, our severe threat for tonight is
trending toward the downward direction.
Monday morning, we`ll see showers clear out of western WI, with dry
weather expected Monday afternoon and evening. Late Monday night, we
may see storm potential pick back up as southerly h85 winds and
associated moisture transport start to tick up. Models right now are
pretty muted on this potential, though as we`ve seen today, models
don`t have the greatest track record with generating enough
convection when you get into the patterns of broad isentropic lift
in a moist environment with a little bit of instability.
Tuesday will feature a strong, negatively tilted short wave working
across the Dakotas during the afternoon, with a cold front sweeping
across MN. With temperature expected to warm in into the low to mid
80s ahead of the front and dewpoints near 70, we`ll have ample
instability for storm development. The CAMs that go out that far
(NAMnest and FV3) both show a pretty healthy band of storms
developing during the heat of the afternoon ahead of the cold front,
which makes sense given the forcing. CSU machine learning severe
probabilities showed an uptick in severe probabilities across the
upper MS Valley, so an upgrade to a Slight Risk when the current Day
3 outlook becomes the Day 2 outlook tonight would not be a surprise.
Not much has changed with the forecast beyond Tuesday. A broad h5
trough will be in place across Canada, with a dip in the flow down
into the Great Lakes. This will put us in northwest flow. This will
result in some pleasant weather conditions as dewpoints fall into
the 40s for several days, with lows in the 40s/50s and highs in the
upper 60s to mid 70s. The only drawback for Wednesday through
Saturday is we`ll likely see northwest winds gusting over 30 mph
each afternoon. We mention it will be mostly dry, but we could see a
little light rain during this period if we see a shortwave working
through in the northwest flow, but there`s been little agreement on
when/where any of these hiccups may occur.
&&
.AVIATION /00Z TAFS THROUGH 00Z TUESDAY/...
Issued at 729 PM CDT Sun Jun 2 2024
Scattered storms ongoing now, mostly across central MN into the
southeast. The storms were generally moving to the ene and there does
look to be a short break this evening before more storms
develop and/or move in. After the second wave of storms later
this evening into early Monday, ceilings will likely be MVFR
for a number of hours, maybe even IFR for a little while early tomorrow
morning. Monday will be much quieter after the MVFR diminishes.
KMSP...One wave of storms just tracked barely south of KMSP
early this evening. The next batch looks likely to arrive around
midnight or 05Z, though it is possible that timing could be
delayed. Confidence on the timing is average at best.
/OUTLOOK FOR KMSP/
TUE...VFR early, then MVFR/SHRA with -TSRA/IFR possible. Wind S bcmg W 10-20 kts.
WED...VFR. Chc SHRA. Wind W 15-20G30 kts.
THU...VFR. Wind NW 15-20G35 kts.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...None.
WI...None.
&&
$$
DISCUSSION...MPG
AVIATION...TDK
Area Forecast Discussion
National Weather Service Marquette MI
820 PM EDT Sun Jun 2 2024
.KEY MESSAGES...
- Isolated afternoon showers possible interior eastern Upper MI
due to converging lake breezes.
- A round of showers and storms moves into the far western UP by early
Monday morning.
- Frequent rain chances this week including thunderstorm
potential through Wednesday. A few strong storms are possible
Tuesday evening and overnight.
- Above normal temperatures through Wednesday, then turning
cooler for the second half of the week.
&&
.SHORT TERM /THROUGH TONIGHT/...
Issued at 302 PM EDT Sun Jun 2 2024
Skies remain sunny across the area with weak ridging sliding over
the Great Lakes and plenty of dry midlevel air in place. Still, some
agitated cu is firing across the eastern UP, with converging lake
breezes off of Superior and Lake Michigan. Cloud tops remain fairly
low so far, and latest model and NUCAPS profiles still show some
thermal capping aloft. If this can be overcome, though, a few
showers out east cannot be ruled out.
Otherwise, temperatures across most of the UP are climbing well into
the 70s, but are a little cooler (mainly 60s) along the shorelines
of the Great Lakes. Dewpoints are dropping into the lower 40s and
even upper 30s in the interior-western UP, but light winds continue
to limit our fire weather concerns.
Meanwhile, RAP analysis shows midlevel troughing digging into the
Plains, with tightening 850mb flow and WAA over MN already touching
off some convection. This feature will continue to swing NE towards
the Great Lakes into tonight while phasing with another wave
currently moving across southern Saskatchewan. Showers finally reach
the far western UP by the early hours of Monday, while a LLJ core
becoming directed over the area potentially lending some divergence.
Some thunder will not be ruled out, but given an unfavorable onset
timing during the pre-dawn hours, would not expect any severe
convection.
Expect an otherwise mild night under increasing clouds. Temperatures
likely won`t fall below the 50 degree mark over most of the UP, save
the far east, where clear skies hold out the longest. There, we may
dip into the upper 40s.
&&
.LONG TERM /MONDAY THROUGH SUNDAY/...
Issued at 416 PM EDT Sun Jun 2 2024
Warm and moist southwest flow ahead of an upper level trough lingers
through Wednesday resulting in almost daily chances for showers and
embedded thunderstorms. There should be a general lull on Tuesday,
but rain chances linger into Tuesday morning across the east and the
next disturbance arrives Tuesday afternoon/evening across the west.
Tuesday looks to be the warmest day this week with highs warming to
near or above 80F except for 70s downwind of Lake MI. A chance for
strong thunderstorms and locally heavy rainfall accompanies a cold
front passage Tuesday night. A cooler but still humid air mass
follows the front as an upper level low establishes a broader trough
across the Great Lakes region late this week. As a result, rain
chances late this week appear much lighter with limited thunder
potential and primarily diurnal in timing.
Starting with Monday morning, the UP will be positioned between
surface ridging to the east and a surface low to the west. A fairly
tight pressure gradient is accompanied by a ~45-50 kt low level
jet that translates east and weakens to 35-40 kts during the
day. This suggests some potential for stronger winds/gusts, but
considerable cloud cover and rain showers inhibit mixing so kept
forecast winds close to NBM. I considered removing thunder
chances on Monday due to meager CAPE values around or less than
100 J/kg, but any breaks in cloud cover could allow for greater
destabilization. Rain showers gradually diminish while tracking
across the eastern UP Monday evening and clearing skies expected
shortly after the front passes. Conceptually, this scenario
suggests potential for terrestrial radiation fog and maritime
advection fog by Tuesday morning.
Terrestrial fog should dissipate Tuesday morning allowing for mostly
sunny skies and temperatures warming to around 80F across most of
the UP. Dew points around 60F indicate potential for unseasonable
destabilization during the day (perhaps in the 2000-3000 J/kg
range), consistent with EFI value of 0.5-0.7. Soundings suggest the
area stays capped on Tuesday until the cold front moves in Tuesday
night, but will need to monitor potential for a pop-up storm along
any lake breeze boundaries that develop. Bulk shear also increases
as the front approaches indicating an increasingly favorable
environment for strong to perhaps severe thunderstorms. Diurnal
timing is more favorable for severe storms to our west, but the warm
sector of a ~990 mb surface low in early June seems more threatening
than the marginal risk currently outlooked by the SPC suggests.
NAEFS guidance also indicates pwats increasing above the 90th
percentile Tuesday evening implying a heavy rain threat.
Model spread increases by Wednesday morning, presumably due to
differences in convective development late on Tuesday. Most
operational 12z models indicate the cold front will still be
overhead or at least nearby Wednesday afternoon implying potential
for afternoon redevelopment, mainly east. Modest mid-level cold air
advection may dynamically destabilize the area on Wednesday leading
to a round of diurnal showers/storms. However, I decided to pull
thunder chances for Wednesday night onward as dew points fall below
50F and cool/dry air advection continues. The upper level low tracks
southeast across the UP Wednesday thru Thursday night resulting in
an extended period of unsettled and showery weather. Total rain
amounts are expected to be light due to lack of quality moisture
while temperatures trend below normal, especially daytime highs.
&&
.AVIATION /00Z TAFS THROUGH 00Z TUESDAY/...
Issued at 819 PM EDT Sun Jun 2 2024
VFR conditions will prevail until an approaching disturbance
spreads showers across IWD/CMX after Mon 12Z, followed by SAW
on Monday afternoon. During rain chances, expect MVFR cigs to
prevail. IWD could see a return to VFR by the end of this TAF
period when the disturbance begins exiting the area, but CMX and
SAW should remain at MVFR. In addition, there will be a LLWS
threat at IWD and CMX early Monday morning with the low-level
jet ahead of aforementioned disturbance. Southerly surface winds
will also exceed the 12 kt threshold with some gusts up to 21
kts Monday morning and afternoon.
&&
.MARINE...
Issued at 416 PM EDT Sun Jun 2 2024
Light winds of 20 knots or less continue today into tonight as weak
surface high pressure continues over Lake Superior. However, as a
cold front moves through late tonight into Monday, southerly winds
gust up to 20 to 25 knots Monday, particularly over the north-
central lake and near tip of the Keweenaw. By Monday evening, winds
diminish to 20 knots or less and stay light until a cold front
approaches the lake Tuesday afternoon with southeast winds gusting
to around 20 kts. The front cross the lake late Tuesday night and
Wednesday with southwest winds to gusting up to 20 to 25 knots over
the western half of the lake behind the front. A low pressure stalls
over northern Ontario for the latter half of the week, resulting in
a prolonged period of unsettled weather including west or southwest
winds gusting to 15-25 kts through Friday evening. A few stronger
gusts up to 30 kts are possible on Thursday.
As for other marine hazards, patches of dense marine fog are
occurring across northeastern Lake Superior this evening. Dew point
temperatures well above lake water temperatures and several periods
of rain indicate potential for fog redevelopment on Monday through
Tuesday night. A few thunderstorms are possible across the western
lake tonight before spreading across the remainder of the lake
Monday and Monday evening. Another cold front Tuesday night brings
scattered thunderstorms across the lake from west to east from
Tuesday afternoon through Wednesday. While severe thunderstorms are
not expected at this time, a few stronger storms capable of hail,
gusty winds, and frequent lightning are possible Tuesday night into
Wednesday
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
None.
Lake Michigan...
None.
&&
$$
SHORT TERM...LC
LONG TERM...EK
AVIATION...TDUD
MARINE...EK
Area Forecast Discussion
National Weather Service Omaha/Valley NE
653 PM CDT Sun Jun 2 2024
.KEY MESSAGES...
- Strong winds and a line of storms is still on track to move
into the area after 9 PM this evening. Wind gusts potential is
decreasing to only as high as 70 mph, especially going east.
- Some flooding is possible overnight, but will be limited by
faster storm speed.
- Storm chances continues Monday and Tuesday, with the highest
potential for additional severe weather being Tuesday.
- Mostly dry Wednesday into the weekend with highs in the mid
70s through mid 80s.
&&
.DISCUSSION...
Issued at 357 PM CDT Sun Jun 2 2024
Today:
Water vapor imagery this afternoon continues to feature out messy
zonal pattern with a shortwave embedded in the zonal flow moving
into the the High Plains. Taking a look at a recent surface
analysis, a strengthening frontal interface stretches from
southeast Colorado northward into northwest South Dakota, with
falling surface heights, and as a result, increasing surface
moisture advection being seen along it. To the east,
temperatures generally in the 70s are in place across eastern
Nebraska and southwest Iowa, largely due to morning and early
afternoon convection that persisted. Gusty winds of 20 to 30 mph
are making for a breezy afternoon as well, with the strongest
winds being in eastern into central Nebraska. Weak showers and a
few sprinkles continue to waft across areas southeast of
Norfolk, but should not pose any severe threat due to the
limited instability in place.
The forecast for a potential line of storms or MCS to move into the
area this evening continues to stay on track, with impressive
instability and sufficient shear held in a narrow corridor just to
the east of the aforementioned frontal interface up the High Plains.
Supercells will continue to develop in those areas, eventually
growing upscale into a cluster of storms or an organized bowing
segment. RAP forecast soundings in central Nebraska show impressive
downdraft CAPE (DCAPE), which CAMs seem to be locked onto while
producing wind gusts over 80 mph in central Nebraska. The main
caveat for it`s progression into our area will be the
morning/afternoon`s influence on the convective parameters. Weaker
shear that will be less than 30 kts and a capped 2000-2500 J/kg of
CAPE will make the stronger wind gusts a lower probability as
it moves eastward. Additionally, a weaker gradient of
instability may also guide the bow southeast rather than
straight east. The weaker shear in our local area will provide
resistance to MCS maintenance, as it will trend closer and
closer to being outrun by it`s gust front (and subsequently
lowering the wind speed potential of the system). Regardless, we
still are expecting strong winds to move into eastern Nebraska
around 9 PM, before exiting/dissipating by 4 AM. The weaker
nature of the bowing segment should limit rainfall intensity to
go along with it`s fast movement, but soils in parts of
northeast Nebraska and into Iowa are still saturated and
flooding remains a possibility (though rainfall amounts
generally should stick below on inch).
Monday and Tuesday:
For Monday most of the area is expected to stay dry, with a few
pop-up showers and storms that many of the CAMs depict
developing during the afternoon, dissipating by sunset. Very
weak shear will make any severe weather unlikely, with coverage
of storms depending on how the residual inversion will be and
how strong storm outflows will be colliding.
Our next best chance at showers and storms come Tuesday afternoon
and evening, as deeper trough interrupts the zonal flow aloft and
drags a cold front through the region. Global deterministic models
indicate that ML instability will be hard to come by anywhere
outside of southeast Nebraska and Iowa, and those areas will
represent our best chances for and severe weather. On the bright
side, the sweeping front is expected to set the stage well for a
nice end to the week.
Wednesday and Beyond:
Behind the departure of Tuesday`s system, swift northwesterly flow
will find itself entrenched over the central CONUS. The main axis of
the mid/upper jet streak will be bisecting the forecast area,
guarding us from any of the better moisture return. Instead, we`ll
enjoy highs in the upper 70s to low 80s and afternoons with gusts of
20 to 25 mph to enjoy while we dry out a bit and give rivers and
soils some recovery time.
&&
.AVIATION /00Z TAFS THROUGH 00Z TUESDAY/...
Issued at 642 PM CDT Sun Jun 2 2024
Thunderstorm chances at the three TAF sites looks pretty
unlikely until a line of storms will push through from west to
east overnight (between 04Z and 08Z Monday). With the line of
storms, we`re expecting some heavy rain and occasional/temporary
IFR visibility. Damaging wind gusts are possible with these
storms, but 35-45 knot winds are the safest bet for max wind
gusts... generally along the leading edge of the precipitation
or even just prior to it.
Behind the line of storms, expect 5-15 knot winds from the west.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...None.
IA...None.
&&
$$
DISCUSSION...Petersen
AVIATION...Nicolaisen
Area Forecast Discussion
National Weather Service Paducah KY
618 PM CDT Sun Jun 2 2024
.KEY MESSAGES...
- An unsettled weather pattern is forecast to remain in place
through much of this week, resulting in on and off chances of
showers and storms, mainly Monday through Wednesday.
- The storms on Monday will be capable of producing very heavy
downpours, gusty winds and small hail. Localized flooding will
also be possible.
- High temperatures are projected to trend warmer, reaching the
mid to upper 80s Monday to Wednesday.
&&
.UPDATE...
Issued at 616 PM CDT Sun Jun 2 2024
Updated aviation discussion for 00z TAFs.
&&
.DISCUSSION...
Issued at 325 PM CDT Sun Jun 2 2024
High pressure has allowed for dry conditions today, with the
exception of a spotty light shower in the northeast this
afternoon. Temperatures have risen to the upper 70s to mid-80s
range. Some model guidance suggests minor visibility decreases
tonight in the east.
Active weather begins tomorrow as a disturbance moves
northeastward from Oklahoma. Model trends have been towards
delaying start time, with SEMO getting showers and storms
beginning during the afternoon hours. Showers and storms
continue through the evening and overnight hours. CAMs show a
fairly substantial spread regarding timing and location but
somewhat agree on a semi-organized line near sunset or
overnight, primarily affecting SEMO. HREF PMMs suggest the
potential for substantial rainfall in SEMO, and the Ozarks in
particular. However, this largely comes from the 12Z HRRR and
the NAMnest. The 18Z HRRR alters the location of heavier
rainfall and is lower on top end amounts, while the NAMnest is
an extremely wet outlier and most ambitious with shear that also
seems to be trending closer to the other models as the 18Z data
starts rolling in. Robust instability to 3000 J/kg will produce
convection but, with shear around 20 kts or less (aside from
the NAMnest), severe weather potential should be somewhat
limited, making heavy rain and flooding issues the primary
concern. Models weaken showers/storms that make it to eastern
portions of the Quad State, so better potential for strong
storms and rainfall will be in SEMO and nearby portions of
IL/KY.
Due in large part to variation in handling of the late Monday
to early Tuesday storms, models disagree on additional
showers/storms later in the day Tuesday, either via a smaller
scale disturbance or just delayed progression of the first
system. A much clearer source of showers and storms will be
ahead of the Wednesday frontal passage. Shear is a little
better, but instability reduced, keeping storm severity
potential fairly limited. Across the Monday-Wednesday time
period, 1-2 inches of rainfall is likely, with higher amounts
most likely to occur in SEMO.
Drier conditions move in for the end of the week as high
pressure moves southeastward. Strong mid-level low pressure in
the Great Lakes and high pressure in the Desert Southwest sets
up northwesterly flow aloft. Models favor a track southwest of
the Quad State for the primary NW to SE flow though a slight
chance of precip returns for the weekend.
&&
.AVIATION /00Z TAFS THROUGH 00Z MONDAY/...
Issued at 616 PM CDT Sun Jun 2 2024
Tranquil weather will prevail tonight as mid level cu will
diminish with the loss of diurnal heating. There is the
possibility of some BCFG at KOWB that may lead to MVFR vsbys
between 08-12z. Additional cu around 3.5-5.0 kft AGL can be
expected during the day Monday as a disturbance begins to
approach from the west. Isolated convection may begin to arrive
in the vicinity of KCGI towards the end of the TAF period after
22z. Winds will be light out of the south between 5-10 kts.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...None.
MO...None.
IN...None.
KY...None.
&&
$$
UPDATE...DW
DISCUSSION...ATL
AVIATION...DW
Area Forecast Discussion
National Weather Service Pocatello ID
556 PM MDT Sun Jun 2 2024
.UPDATE...
Latest high-resolution data continues to support heavy rain
development overnight tonight into Monday across the Sawtooth
area. Probability of rainfall amounts of up to 2 inches in this
region on top of snowmelt, looking at a high likelihood that we
could see 3 to 4 inches of liquid moving down small creeks and
streams towards the upper Salmon River. Although it still remains
unlikely that there will be much flooding on the Salmon itself,
those smaller tributaries will likely become overwhelmed. This
also means an increased potential that backcountry hikers and
campers could get trapped. So because of the increased confidence
in the long duration heavy rain forecast on top of snowmelt, have
decided to issue a flood watch mainly for areas west of highway 75
from Ketchum through Stanley.
13
&&
.PREV DISCUSSION... /issued 300 PM MDT Sun Jun 2 2024/
..STORM SYSTEM TO BRING SOME FLOODING AND WIND HAZARDS TO
SOUTHEAST IDAHO MONDAY...
SHORT TERM...TODAY THROUGH MONDAY NIGHT...
This afternoon remains "the calm before the storm" as weak troughing
supports breezy conditions over much of the CWA and perhaps a couple
showers or an isolated t-storm across the NE and E-cntrl highlands,
while the rest of the region holds dry. Winds may approach WIND
ADVISORY criteria across the Arco Desert/Mud Lake region this
afternoon, and may also approach LAKE WIND ADVISORY criteria for
American Falls Reservoir, but in both cases the scenario looks
borderline with not all guidance reaching criteria and stronger
winds are enroute for Mon, so we continue to let the forecast speak
for itself today. Highs will reach the upper 60s to upper 70s.
Now for the main event...later tonight through Monday, a low
pressure storm system and associated atmospheric river of moisture
remains progged to bring a period of moderate to heavy rainfall to
the mountains west of Ketchum, Galena Summit, and Stanley. This is
our main corridor of concern hydrologically. 1 to 2 inches of
rainfall is expected, with locally higher amounts along and west of
the spine of the Sawtooths, and lower amounts east of ID-75. A
couple thunderstorms are also possible, especially Mon afternoon.
Our official forecast (which leans on WPC calibrated QPF guidance)
continues to run near the 99th percentile of the NBM which has been
toward the lower end of our various guidance sources, and has
changed little compared to 24 hours ago except QPF totals have
decreased slightly in the valleys adjacent to the Sawtooths such as
the Sawtooth and Wood River Valleys (no real change up along the
ridgeline of the Sawtooths). Now that this event has drifted into
the period of the HREF, the ensemble mean is advertising 1.50" to
2.00" QPF in the Sawtooths which certainly supports the WPC
guidance, and the ensemble max even exceeds 3.00"! In addition,
temps holding above freezing throughout the event (including AM lows
Mon right up to near mntn peaks) will result in an additional 1 to 2
inches of liquid melting out of the high elevation snowpack east of
Stanley and Ketchum, and as much as 3 to 4 inches west of Stanley
and Ketchum, as modeled by NOHRSC. This combination of moderate to
heavy rain and melting snow may result in strong rises and localized
flooding along smaller creeks and streams, as well as localized
rockfalls and landslides. We can easily envision some backcountry
roads and trails may becoming impassable, and we`ll need to keep an
eye on the Ross Fork burn scar west of Galena Summit as well. The
period of greatest potential impacts up along this corridor of
greatest concern is expected from 2 AM early Monday morning through
8 PM Monday evening. Still a touch of overall uncertainty on whether
the current, much-higher-than-NBM QPF forecast will fully verify as
well as exactly how much heavy rainfall will be able to spill over
the Sawtooths on a westerly flow, and in general mainstem rivers are
not forecast to reach flood stage with this relatively limited 12-18
hour event. Thus, we continue to run with an SPS for messaging
(added some additional detail and timing information to the
statement) as opposed to issuing a FLOOD WATCH. Elsewhere across the
rest of SE Idaho, fairly widespread rain and/or shower activity is
expected from mid-AM Mon through at least early Mon afternoon,
transitioning west to east, before the regime becomes a bit more
convective with isolated t-storms possible, ending by sunset. On the
QPF side of things, the region should be able to easily handle a
widespread 0.10 to 0.50 inches of rain, with a few locally higher
amounts the Centennials, Big Holes, and Bear River Range. While
overall afternoon instability will be a bit modest, strong 700mb
flow as high as 50kts may assist a few storms in mixing strong gusty
winds down to the sfc.
The other main impact from this system will be moderate SW winds
ramping up by mid-late Mon AM, and continuing through about sunset.
Over the Arco/Mud Lake Deserts and Snake Plain...where speeds may
reach 25-35 MPH with gusts to 55 MPH...a WIND ADVISORY has been
issued from 9 AM to 9 PM. Our NBM-led forecast has trended just
slightly higher on peak winds over the last 24 hours, as has the
HREF and projected 700mb winds on the GFS, but at this time we still
feel this will be a solid advisory-level event vs. a high wind
event. Still, there is perhaps a 20% chance that at least the
Arco/Mud Lake Desert zone may be considered for an upgrade to a HIGH
WIND WARNING if guidance continues to trend higher. One concern is
modest low-level lapse rates of 6.5-7.5 degC/km advertised on
NAMNest and RAP forecast soundings even "out in the clear" behind
the steadier rain exiting eastward Mon afternoon which could damper
full mixing potential, although system dynamics could try to
overcome this (and certainly any stronger t-storm should be able to
tap into this flow). Can`t rule out localized blowing dust, but the
overall blowing dust risk may be mitigated by the rain and shower
activity moving through over the course of the day. Unless
guidance trends higher, main wind impacts are likely to be
difficult driving for high-profile vehicles and unsecured outdoor
objects blowing around. All impacts from this storm system are
expected to settle down by around sunset Mon eve. High temps Mon
will also hold about 10 degrees cooler compared to
today...generally upper 50s to upper 60s. - KSmith
LONG TERM...TUESDAY THROUGH NEXT SUNDAY...
Generally held with NBM guidance for the rest of the forecast as
main focus is on Monday`s system. Synoptically, a building ridge of
high pressure will take control and support drier conditions with a
solid warming trend resuming, although at least isolated diurnally-
driven showers and t-storms return to the forecast starting Thu
afternoon and beyond. Winds will still be breezy Tue afternoon, and
to a lesser degree Wed afternoon, before becoming light through the
remainder of the extended period. Forecast high temps have actually
nudged just a few degrees cooler, although still approaching 90 for
many lower elevation population centers each day starting Thu. - 01
AVIATION...
A wet system works into East Idaho beginning tonight. There is
still a very low probability of seeing a shower or thunderstorm
develop this afternoon around DIJ, otherwise rain shifts into the
state after midnight and spreads across all terminals by/around
sunrise. Expect CIGS to trend down from VFR to MVFR with
occasional IFR in heavier showers/potential thunderstorms during
the day. Gusty winds today weaken slightly overnight but return
with a vengeance during the day Monday. Expect the strongest winds
Monday afternoon from KPIH-KIDA and across the Arco Desert, 25-
30kts sustained with gusts around 45kts. - DMH
FIRE WEATHER...
The next system arrives this evening with precipitation reaching
the central mountains tonight. Widespread wetting rains will
overspread the region early Monday with chances for isolated
thunderstorms during the afternoon and evening. The Weather
Prediction Center has included portions of Fire Weather Zones 475,
476, and 422 in their Excessive Rain Outlook. The most
accumulated rainfall will be over the Sawtooths and Stanley
region, where 1 inch to 2.5 inches of QPF is forecast to fall
between this evening and Monday night. During this 24-hour or so
timeframe, 1.25" to 1.75" is forecast over the eastern half of the
Ross Fork burn scar, with 1.75" to 2.25" over the western half.
Elsewhere, generally 0.50" or less is forecast with higher totals
of 0.75" to 1" in the high terrain of the eastern mountains. Min
RH will continue to increase through Monday, ranging 20 to 35
percent for much of the region today before rising to 50 percent
and higher. Elevated winds aloft will support breezy conditions at
the surface each afternoon and evening beginning today and
continuing through Tuesday or Wednesday. The strongest SW to W
winds are expected across Fire Weather Zone 410, where SW winds
will range 25 to 35 mph with gusts 45 to 55 MPH. The pattern
turns dry and warmer beginning Tuesday as a ridge of high pressure
builds in from the Southwest. Temperatures may even reach into
the 90s for some portions of the Magic Valley and Snake River
Plain beginning Thursday into next weekend. Widespread minimum
humidities will begin to drop below 25 percent during this
timeframe, but winds should remain light. - Cropp
HYDROLOGY...
To review from the SHORT TERM section above...a general 1 to 2
inches of rainfall, coupled with 1-3 inches of SWE melt from
remaining high-elevation snowpack, is expected with Monday`s
system. This combination of moderate to heavy rain and melting
snow may result in strong rises and localized flooding along
smaller creeks and streams, as well as localized rockfalls and
landslides. Some backcountry roads and trails may become
impassable. The period of greatest potential impacts is expected
from 2 AM early Monday morning through 8 PM Monday evening. Anyone
with plans in the backcountry and mountains in the Ketchum,
Galena Summit, and Stanley corridor should monitor this situation
closely and be prepared for hazardous conditions. Consider
altering your plans to avoid being in the mountains or backcountry
during this period.
While this is a lot of water, in general this event is expected
to be more of a smaller creeks and streams issue with flooding
generally not expected along the larger rivers. The Salmon and Big
Wood rivers are currently expected to rise around 1 foot, and
Valley Creek in Stanley could reach bankful, if not higher.
Currently action stage on the Big Wood at Hailey is not forecast,
but action stage for the Big Wood at Hailey is possible depending
on actual snowmelt and rainfall. Looking east toward the WY
border, currently only small rises are expected on mainstem rivers
for Monday and Tuesday. Some streams in the mountains could
approach bankful. - Wyatt/KSmith
&&
.PIH WATCHES/WARNINGS/ADVISORIES...
Wind Advisory from 9 AM to 9 PM MDT Monday for IDZ052>054.
Flood Watch from midnight MDT tonight through Monday evening for
IDZ072-073.
&&
$$
Area Forecast Discussion...UPDATED
National Weather Service San Angelo TX
643 PM CDT Sun Jun 2 2024
...New AVIATION...
.SHORT TERM...
(This evening through Monday)
Issued at 204 PM CDT Sun Jun 2 2024
...Isolated to widely scattered storms possible again...
Severe convection is currently moving south into the Big Country
as of 2 PM this afternoon. This cluster of storms will likely lay
down an outflow boundary, while moving south. Outside of that, the
dryline will again tighten up to our west as shortwave energy
moves into west and west central Texas. Currently, surface based
CAPEs range from 3500 J/kg to as high as 5500 J/kg, and effective
bulk shear values generally 35 knots to 45 knots. With these
conditions, generally any storm that does develop will have a good
chance of strengthening to severe levels, and be capable of
producing hail over 2 inches in diameter, as well as wind gusts
over 60 mph. In addition, any storms that interact with any
outflow boundaries available will pose at least a small tornado
threat.
Outside of the storms just north of our area, expect dryline
storms to develop by late afternoon or early evening. HRRR
develops convection from the Caprock south into the northern
Permian Basin by late afternoon which then moves east into our Big
Country during the late evening hours. We could also see the
small complex of storms moving into Haskell and Throckmorton
counties right now continue south/southeastward into the eastern
Big Country during the late afternoon and early evening.
Outside of the thunderstorms, it will be another warm and muggy
night, with lows in the upper 60s to mid 70s, with temperatures
warming several degrees tomorrow. Highs will range from the mid
90s to around 100 degrees.
&&
.LONG TERM...
(Monday night through next Sunday)
Issued at 204 PM CDT Sun Jun 2 2024
For Monday evening, isolated thunderstorms are possible, if the
cap can be eroded, across mainly the Heartland and Northwest Hill
Country. A few storms may be severe with the main hazards being
large hail and damaging winds.
Otherwise, expect hot and mainly dry conditions for much of this
week due to an upper level ridge building across the Southern
Plains and a 850 MB thermal ridge of 28-30 deg C. Highs will be
upper 90s to around 106 Tuesday through Thursday. Also, heat index
values may reach 105 to 110 across the southern Heartland and
Northwest Hill Country Tuesday and Wednesday. Heat Advisories may
be needed for southern and western portions of west central Texas
on Tuesday and Wednesday. Please follow heat safety precautions.
Expect slightly cooler temperatures next weekend with highs in the
90s to around 100.
&&
.AVIATION...
(00Z TAFS)
Issued at 641 PM CDT Sun Jun 2 2024
As we progress into this evening, there remains a possibility for
a few thunderstorms. With low confidence in extent of development
and placement, not carrying thunderstorms in our TAFs at this
time. However, will monitor radar trends and update TAFs as
needed. Conditional thunderstorm hazards include localized gusty
winds, hail, and brief reductions in visibility and ceilings from
locally heavy rainfall. Gradual clearing is expected tonight,
followed by low cloud development and expansion late tonight and
early Monday morning. Expect MVFR ceilings with the low clouds.
By late Monday morning, low cloud cover should break up. Some
scattered VFR-based cumulus are possible over our eastern counties
early Monday afternoon, while generally clear skies are expected
farther west. Winds will be mostly from the southeast to south
tonight, and mainly from the south Monday morning. Expect increased
and somewhat gusty south or south-southwest winds Monday afternoon.
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 71 95 72 101 / 40 20 10 0
San Angelo 73 100 73 104 / 20 10 0 0
Junction 75 100 75 103 / 10 10 10 0
Brownwood 72 91 71 96 / 30 20 20 0
Sweetwater 72 98 73 101 / 30 10 0 0
Ozona 74 98 72 101 / 10 0 0 0
Brady 72 93 73 96 / 20 20 20 0
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SHORT TERM...20
LONG TERM....21
AVIATION...19