Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 06/17/24
Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
907 PM CDT Sun Jun 16 2024
.KEY MESSAGES...
- Strong to severe thunderstorms are possible again late tonight
into early Monday. The main area of concern is along and south
of a line from Pierre to Watertown. Large hail will be the main
threat along with wind gusts between 60-70mph.
- The threat for strong to severe storms continues over the entire
forecast area Monday evening/early Tuesday, with large hail and
wind gusts between 60-70mph as the main threats.
- A moderate risk (40%) for excessive rainfall/flooding still
exists over far northeastern SD into west central MN, where 2"+
could fall tonight through early Tuesday. Trends have been for
lower confidence that this area will face multiple rounds of
thunderstorm activity, however.
- Showers and storms will linger across the east on Tuesday, with
a chance for a few strong to severe storms during the afternoon.
Otherwise,quiet and dry conditions return by Tuesday night
through Wednesday night and/or early Thursday before another
disturbances moves into the region with increasing chances
(60-80%) for showers and storms late this week.
&&
.UPDATE...
Issued at 904 PM CDT Sun Jun 16 2024
No major changes made to the forecast this evening. Still looking
for showers and thunderstorms to develop across the southern part
of the CWA around or shortly after midnight, then spread
east/northeastward overnight into Monday morning. No changes made
to winds or temperatures at this time.
&&
.SHORT TERM /THIS EVENING THROUGH MONDAY NIGHT/...
Issued at 302 PM CDT Sun Jun 16 2024
Elevated convection has developed across the forecast area this
afternoon however dewpoint depressions are on the order of 30+
degrees and cloud bases exceed that of the ASOS ceilometer...so
looking at just virga at this point.
Overnight tonight, CAMS support convection developing around 02-04Z,
though the focus for convective development has again trended more
south and east compared to previous runs. RAP MUCAPE values show a
gradient south to north across the CWA of around 1500/2000 j/kg and
about 500j/kg respectively, though what is much more impressive is
the shear which is 60-70kts. Pretty straight line hodographs support
a fast moving, splitting supercell environment with hail threat
across the southern CWA. 2-5km Updraft Helicity from the HREF points
to mainly right moving storms, and based off hodographs that should
cause the strongest storms to progress in a more or less eastward
direction, which is why CAMS are leaning towards a more eastward
progression of QPF compared to previous runs, which also means the
focus for heavy rainfall has also shifted, along with the more
organized threat for potential flooding, towards and south of the
Watertown area.
CAMS suggest convection is much less organized and with less
coverage elsewhere tonight/early Monday for the rest of the CWA.
Probabilities for just a half inch have fallen to only 40 percent for
Pierre and 20 percent for Aberdeen, and is negligible for Mobridge.
The probability for an inch accumulation for Watertown is 50
percent.
Focus then shifts to the second round of more organized convection
late Monday into early Tuesday. The main mechanism for severe storm
generation appears to be the development of a low level jet. The jet
intensity strength tops 60kts in the NAM with a focus up along the
Coteau. NAM MLCAPE is around 2000j/kg at 06Z up in that area and a
widespread 3000-4000j/kg MUCAPE thereafter. Shear is a more modest
40-50kts. BUFKIT still shows fairly stable boundary layer conditions
for most sites with an inverted trough across the area, and the
surface low doesn`t lift through until the early morning hours,
suggesting again mainly a large hail threat associated with this
outlook. CAMS also show a bit of random coverage of convection, so
at this point while heavy rain is still expected to present a
threat, its uncertain if storms will move over the same areas that
had previous convection/heavy rain. Thus, despite the WPC moderate
risk outlook, no watch at this time.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
Issued at 302 PM CDT Sun Jun 16 2024
The main forecast challenges in this period will continue to revolve
around the active pattern that has become entrenched across our
region as of late. We will get an initial break early from the
active storminess but it will be short lived as better opportunities
for showers and storms return the latter half of the forecast term.
Models are in fair agreement initially showing a sfc low pressure
system tracking across eastern SD into western MN Tuesday morning
with a trailing cold front passing west to east through our forecast
area during the day on Tuesday. Lingering showers and thunderstorms
will be possible during this time, especially east of the James
Valley through perhaps midday into the first half of the afternoon.
Guidance does hang onto some instability and decent shear in our
eastern zones into early afternoon. SPC has highlighted our far
eastern zones in a marginal(1/5) risk for severe weather. Timing
will be everything when it comes to the risk in our east by Tuesday
afternoon. That system will depart to our east by Tuesday night and
leave us with a fairly quiet, pleasant and mostly dry Wednesday. Sfc
high pressure will build in at that time. Sfc dew point temperatures
drop during the day into the 40s to low 50s with high temps mainly
in the 70s to near 80. Wednesday looks to be the nicest day of the
period.
The sfc high is progged to shift east of our area on Thursday. An
east to southeast low level flow is expected to develop. This return
flow will be the beginning`s of yet another active stretch through
the remainder of the period. Perhaps some of us will squeak out a
mostly dry daytime period on Thursday, especially our northern
zones. But, PoPs will be on the increase nonetheless by the latter
half of the day into Thursday night. Another sfc frontal boundary is
anticipated to set up shop in our southern zones or just to our
south later Thursday into Friday and perhaps into the beginning of
next weekend. Mid level flow will remain southwesterly that will
contain periodic shortwave energy that will rotate southwest to
northeast through the region the latter half of the week...a pattern
much similar to what is currently underway across our region. A good
chance for showers and storms will persist through at least Friday
and perhaps linger into Saturday. We`ll have to consider chances for
strong to severe storms again by late in the week as joint
probabilities for SFC CAPE/CIN and bulk shear show
increasing percentages for those favorable ingredients for storms.
&&
.AVIATION /00Z TAFS THROUGH 00Z MONDAY/...
Issued at 624 PM CDT Sun Jun 16 2024
Terminals KABR,KATY,KPIR,KMBG
Scattered showers will occur across mainly the eastern part of the
region this evening. VFR conditions will prevail across the area
through the early overnight hours, then look for showers and
thunderstorms to develop across much of the area later tonight.
The best chance for strong, to possibly severe, storms will be
along and south of a line from Sisseton to Pierre. Periods of MVFR
vsbys will be possible with any thunderstorms. The storm threat
will diminish Monday morning, but chances for rain showers will
continue, along with cigs falling to IFR/MVFR levels.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...None.
MN...None.
&&
$$
UPDATE...Parkin
SHORT TERM...Connelly
LONG TERM...Vipond
AVIATION...Parkin
Area Forecast Discussion
National Weather Service Columbia SC
812 PM EDT Sun Jun 16 2024
.SYNOPSIS...
High pressure, drier conditions, and slightly above normal
temperatures are then expected through mid-week. Unsettled
conditions are possible by late in the week into next weekend.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
Expect scattered convection into the evening again. Convection
which began along the sea breeze has pushed inland, sparking
additional showers and thunderstorms as outflow boundaries
collide. Ridging over the area has led to warm air aloft, which
will limit the threat of severe weather. However, PWAT values
around 1.6 inches and an inverted V sounding will support some
localized downburst winds likely below severe thresholds.
Patchy fog may be possible late tonight, especially in areas
that get rainfall. Much of tonight will be partly cloudy, but
towards morning some stratus is expected. Overnight lows remain
near 70.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY NIGHT/...
High pressure aloft builds over the Carolinas on Monday and then
expands northward to the Mid Atlantic States and New England Tuesday
through Wednesday. This H5 high center shunts the best moisture to
the west of the region with precipitable water levels decreasing to
around one inch. This should lead to dry weather conditions and near
normal temperatures.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
There is a fair amount of uncertainty in the forecast for the second
half of this week. The ensembles bring an inverted trough into the
Southeast U.S. Thursday through Thursday Night. The ensembles also
shift an H5 high pressure system southward in response to a
strengthening polar jet stream along the Canadian border near the
Great Lakes and New England. The ensembles vary on whether the H5
upper high center is directly over the Carolinas or offshore.
If the inverted trough moves onshore closer to the Midlands and
CSRA, the region would see a significant increase in moisture and
diurnal convective activity. Otherwise, if the H5 high centers
itself over the Carolinas, it should limit such convection. The
ensembles show a wide range on temperatures from Thursday
through next weekend which is indicative of model uncertainty.
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
Widely scattered showers diminishing early this
evening...focused near the AGS/DNL terminals. Restrictions
possible late tonight/around 12z in stratus.
A pressure ridge centered off the Mid Atlantic coast extends
southwest into the Carolinas. A persistent east-southeast low-
level moisture transport will continue overnight into Monday.
Model guidance including the lamp, HRRR and NBM support stratus
focused especially near the AGS/DNL terminals toward morning.
Moderate confidence for at least a period of MVFR strato-
cumulus at those sites with IFR possible toward 12z. Confidence
is lower at other terminals for restrictions, so kept VFR for
now at CAE/CUB and OGB. Low clouds should mix out by 15z and
expect scattered to broken cumulus into the afternoon with
southeast winds 5 to 10 knots. Capping appears stronger Monday
as upper ridge settles over the area. Moisture decreases by late
in the afternoon, so showers not expected at this time Monday
afternoon.
EXTENDED AVIATION OUTLOOK...Low probability of significant
restrictions.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...None.
GA...None.
&&
$$
forecast discussion). Monday still looks to be the hottest day of
this stretch of heat, with high temperatures in the middle to upper
90s, and heat indices in the middle/upper 90s, near 100 for
some isolated areas. We will have to watch closely for the
potential for Heat Advisory headlines as the latest guidance
indicates a period of at least 6 hours or more of 100+ degree
heat indices, mainly for our west-central Illinois/far
southeastern Iowa counties. Although the guidance has come into
better consensus on these values, there is still at least some
noticeable spread among the CAMs for dew point temperatures,
with a spread of around 2 to 5 degrees F between the 25th and
75th percentiles on the 16.12z HREF, so confidence is a bit
lower on how high the heat indices will reach. Regardless, it
will be a hot day all-around, so anyone that will be outdoors
for a period of time should take extra precautions to protect
themselves from the heat!
&&
.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
Issued at 221 PM CDT Sun Jun 16 2024
Monday night through Tuesday night will remain quite warm for this
time of the year, with yet another day of high temperatures into the
lower to middle 90s and heat indices into the middle to upper 90s
for Tuesday. Overall, Tuesday`s heat appears to be similar to what
we are experiencing today, so heat headlines aren`t expected at this
time for Tuesday. As we`ve been mentioning, new record highs aren`t
expected with this stretch of heat, but we are more confident
for record warm low temperatures to be broken, especially for
tonight, Monday night, and Tuesday night. See the Climate
section below for the list of records that could be tied or
broken.
A pattern change is expected to occur by Wednesday, as the upper-
level ridging over the eastern US breaks down, and a longwave trough
develops over the Intermountain West region. As the trough
approaches, an attendant cold front will sweep through the area,
which will bring widespread chances (30 to 60%) of showers and
storms. This should bring at least some relative relief to the
heat and humidity, although high temperatures in the upper 80s
to lower 90s south of the Highway 20 corridor will remain
possible for Wednesday through Friday. A few additional mid-
level shortwaves are expected to overtop the ridge into our
area, so additional chances of precipitation will be in place
through the end of the week. Chances for strong to severe storms
remains low, which is evident in the CSU severe weather
probabilities indicating either very low probabilities or none
at all for this period.
&&
.AVIATION /00Z TAFS THROUGH 00Z TUESDAY/...
Issued at 636 PM CDT Sun Jun 16 2024
VFR conditions are expected through the period. Winds will
become less strong overnight and then increase again tomorrow
AM. There is 15% chance for thunderstorms tomorrow, however due
to low coverage and confidence where they may form, have opted
to leave out of TAFs at this time.
&&
.CLIMATE...
Issued at 300 AM CDT Sun Jun 16 2024
Record High Temperatures:
June 17:
KBRL: 98/1944
KMLI: 98/1897
Record Warm Minimum Temperatures:
June 16:
KMLI: 77/1918
June 17:
KDBQ: 74/1921
KMLI: 78/2018
June 18:
KDBQ: 74/1921
KMLI: 77/2018
June 19:
KDBQ: 76/1931
KMLI: 78/1953
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...None.
IL...None.
MO...None.
&&
$$
SHORT TERM...Schultz
LONG TERM...Schultz/Uttech
AVIATION...Gibbs
CLIMATE...Schultz/Uttech
Area Forecast Discussion
National Weather Service Sioux Falls SD
655 PM CDT Sun Jun 16 2024
.KEY MESSAGES...
- Potential for a higher end severe weather risk tonight into
Monday across the CWA. Elevated supercells supporting large
hail to around baseball size will be very possible, with a
smaller wind risk. Best chances near and north of I-90.
- An increased risk for heavy rain and potentially flash
flooding will also be present late tonight into Monday.
Increased confidence that the heaviest rain will be near and
north of I-90 towards highway 14.
- Low confidence on Monday afternoon and evening but another environment
may develop which would support elevated supercells and large
hail.
- Very unsettled pattern through most of next week. Ensemble guidance
through the week suggests nearly a 50% probability for as
much as 4" of rain through next weekend. Flooding concerns
definitely grow during this time given expected pattern.
&&
.DISCUSSION...
Issued at 159 PM CDT Sun Jun 16 2024
By late this afternoon and this evening the low level front
should be near the Missouri River into parts of northwest IA
with the front around 850mb closer to somewhere between the Mo
River and I-90. Model soundings still pretty bullish with
capping of the lower levels, suggesting that any forcing or
parcel ascent below about 850mb will not produce any convection.
The models do have a very weak wave in northeast CO this
morning that moves towards northwest IA by early evening. A few
models try to produce some scattered convection but this seems
very unlikely. Some backing of the low level winds does try to
occur from about 6-8pm, but appears to be more focused
southwest of the area and motion northeast would be slow. The
nam seems too aggressive with moisture around 850mb late
afternoon and early evening which might be why the cap weakens
and some convection develops. Most other models do not have this
and given the latest 850mb analysis the better advection of the
deeper moisture will come later when the main wave ejects onto
the Plains.
Once this wave moves onto the Plains this evening forcing
across the boundary increases significantly and convection
should rapidly develop between about 3z and 6z. The latest HRRR
and Rap showing about 2500- 3000 J/kg CAPE and moderate shear
which will support scattered supercells with the main threat
being large hail, possibly around baseball size. With the deep
stable layer in the low levels tornadoes and wind will be much
lower threats. Model soundings still very consistent in
suggesting that lift from around 800 mb will see the least
amount of convective inhibition which makes that amount of
instability all the more impressive. The models are in good
agreement on the 800 mb front being roughly from Gregory SD to
Flandreau SD to Marshall MN from about 3-6z. The location of
this boundary will be something to watch through the evening in
case it slides a little farther south this afternoon. Once
development takes place supercell motion would likely be east
northeast with some potential to build southward into the lower
level forcing as deeper moisture and increased instability work
into the area.
The other concern with this set up will be heavy rain. The upper
level flow is still expected to be normal to the low and mid level
boundary and with the upper level wave slow to move northeast
backing of the mid level winds remains in place through at least mid
day Monday which will likely support continuous development through
Monday into Monday night. Latest models indicating a very good
chance for 2-4 inches of rain north of I-90 from around De Smet then
into southwest MN.
Really tough to say for sure what will happen from later Monday
afternoon into Monday night as tonight and Monday mornings activity
will dictate the environment a bit, but given the strength of the
wave will not be relying on only instability to get storms going
again. By Monday afternoon and Monday night an environment capable
of strong elevated supercells may exist once again and another round
of severe weather and heavy rain will exist. Once again the
environment would be most supportive north of I-90 and possibly west
of I-29. Some upper level ridging should keep northwest IA,
northeast NE and far southeast SD with very small chances for
thunderstorms Monday mid afternoon into Monday night.
Upper level troughing to the northwest begins to shift east Monday
night into Tuesday and will likely bring renewed chances for showers
and thunderstorms into Tuesday night with severe weather again
possible. The better chances will be east of the James and likely
east of I-29.
This system passes and cooler and less unstable air settles in, but
for now that does not look like the end of rain and thunderstorms.
The right entrance region of the upper level jet lifts northeast and
once again enhances low to mid level flow, bringing additional lift
and moisture into the area and thus more rain and thunderstorms. A
lot between now and then but right now this not does not look like
as big of a severe threat, but with the rain possible near and east
of I-29 again flooding concerns will begin to grow.
Thursday into Sunday will see continued chances for showers and
thunderstorms with mostly westerly flow aloft which brings in
occasional weak waves. Temperatures should be seasonally warm most
days.
&&
.AVIATION /00Z TAFS THROUGH 00Z TUESDAY/...
Issued at 646 PM CDT Sun Jun 16 2024
Multiple rounds of showers and storms are expected to impact the
area during this TAF period, reducing conditions to MVFR and
lower. Confidence in timing and coverage of any round remains
low, especially as you go later into the TAF period. For
tonight, some guidance has convection developing across northern
NE around 17.00-01z, moving into the KSUX and KCKP areas by
03-04z. Given that most guidance which has this development is
struggling with antecedent conditions, confidence is quite low
in this scenario. Otherwise, expect convection elsewhere tonight
to develop by around 17.05z, expanding in coverage through the
overnight hours. Again, confidence in timing/coverage is low for
every round. Strong to severe storms are possible through the
entire period.
Outside of convection, winds shift to east southeastern and
become breezy toward the end of the period with gusts to 30
knots. Lower stratus is expected during the latter half of the
period, especially if convection is more widespread.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...None.
MN...None.
IA...None.
NE...None.
&&
$$
DISCUSSION...08
AVIATION...SG
Area Forecast Discussion
National Weather Service Hastings NE
631 PM CDT Sun Jun 16 2024
.KEY MESSAGES...
- Strong to severe thunderstorms are possible this afternoon-
evening across western portions of the area IF the cap
breaks.
- Highs in the 90s on Monday with heat index values near 100 and gusty
southerly winds of 25-35mph and gusts to 45mph.
- Strong to severe thunderstorms possible Monday evening across western
portions of the area.
- Record warm low temperatures are possible on Monday for Grand
Island and Hastings: See climate section for more detail.
- The highest chance for rainfall comes Tuesday night into
Wednesday as a cold front stalls across southern portions of
the area, with heavy rainfall possible.
&&
.DISCUSSION...
Issued at 334 PM CDT Sun Jun 16 2024
This afternoon and Overnight...
Temperatures this afternoon have climbed into the 90s across most of
the area, with heat index values approaching the low 100s. A weak
front has kept northwestern portions of the area slightly cooler,
with in the 80s.
There continues to be large uncertainty with the potential
thunderstorm development this afternoon. The HRRR has remained
consistent over the past several model runs, keeping the environment
capped, with warm air aloft inhibiting thunderstorm development.
Other CAMs and HREF members indicate weaker capping, with
thunderstorms developing along the front in the McCook vicinity and
moving east into the area. Among the models with thunderstorms this
afternoon, there additional uncertainty to how widespread these
storms will be (due to capping). Some models indicate that only
isolated thunderstorms will be possible, with others showing a more
widespread cluster moving into the area. Areas in the SPC slight
risk have the highest chances to see thunderstorms this afternoon-
evening.
Strong to severe thunderstorms are possible with thunderstorms that
occur this afternoon/evening. Robust instability with SBCAPE values
around 4000 J/Kg will allow for storms to quickly become severe. 0-6
Km shear will be weak (30Kts or less) which will help to limit how
strong storms are able to get. The main concerns with thunderstorms
this afternoon will be for large hail and damaging wind gusts.
As the low level jet develops this evening/overnight, thunderstorm
chances will shift to northern portions of the area. While the
heaviest concentration thunderstorms will be north of the forecast
area, scattered thunderstorms will be possible for areas mainly
along and north of I-80.
Monday...
Any lingering thunderstorms across northern portions of the area
will come to an end Monday morning. Highs will climb into the 90s,
with dewpoints in the upper 60s. Heat index values will be similar
to today, as they peak around 100 degrees. Winds will be gusty
throughout the day on Monday, with sustained winds of 25-35mph and
gusts to 45mph.
Scattered thunderstorms that develop along the western High Plains
will move into western portions of the area during the evening hours
on Monday. While instability will be plentiful, with SBCAPE values of
3000-3500 J/Kg, storms will be entering an environment with
decreasing shear. Storms are expected to weaken as they move
northeast across the area, with rain coming to an end Monday night.
The main concern for these storms will be for damaging wind gusts,
though some large hail is possible if storms remain more discrete.
Tuesday and Wednesday...
A cold front will move across the area during the daytime hours on
Tuesday, bringing cooler weather to the area. Scattered showers and
thunderstorms are expected to develop along and behind the cold
front during the afternoon and evening hours. The cold front will
stall just to the southeast of the forecast area Tuesday night, with
storms becoming more widespread along and north of the front. PWAT
values 150% of normal along with the potential for training storms
will lead to an increased risk for flooding. The entire area is in a
WPC slight risk for excessive rainfall due to this potential for
flooding. Areas that receive multiple rounds of thunderstorms could
see rainfall in excess of 2". Modest instability and weak shear
could allow for a few strong to severe thunderstorms as well.
Showers and thunderstorms will continue through the day on Wednesday
and into Wednesday night. Precipitation is expected to become more
scattered over time. The potential for flooding will continue into
Wednesday, but will likely depend on precipitation Tuesday night.
Temperatures will be cooler on Wednesday with persistent cloud
coverage and precipitation. Highs will range from the mid 60s
(northwest) to the low 80s (southeast).
Thursday Through The Weekend...
The upper level trough over the Rockies which brought precipitation
on Tuesday and Wednesday will gradually lift north and begin to exit
the area Thursday night into Friday. Highs on Thursday and Friday
will return to the 80s along with breezy southerly winds. Scattered
precipitation chances continue on Thursday and Friday. Warmer
weather continues into the weekend with highs in the mid to upper
80s. Scattered thunderstorm chances continue into the weekend,
mainly during the evening-overnight hours.
&&
.AVIATION /00Z TAFS THROUGH 00Z MONDAY/...
Issued at 616 PM CDT Sun Jun 16 2024
For KGRI/KEAR Airports:
Currently have a dry TAF forecast with VFR conditions, with the
better chances for precipitation looking to be north/west of the
terminal areas. Continue the mention of LLWS at both sites from
about midnight on through 14Z, even with the gusty southerly
winds forecast. Some uncertainty with the winds later tonight,
as some models show the potential for outflow to sink south into
the area and in close proximity to the terminal areas.
Otherwise, gusty southerly winds continue on into the day
Monday, with gusts over 30 MPH expected.
&&
.CLIMATE...
Issued at 550 AM CDT Sun Jun 16 2024
-- Regarding possible RECORD WARM LOW TEMPS on Monday
(June 17th):
Both tonight-Monday morning and Monday night-Tues morning are
expected to remain very warm, with most of our CWA not dropping
any cooler than the low-mid 70s. As a result, calendar day
(midnight-to-midnight) records for warmest low temperature
COULD be threatened at Grand Island/Hastings airports (the 2
sites for which we issue formal Record Event Reports/RERs).
Any such records are most likely to be threatened on Monday,
because a cold front arriving Tuesday is currently expected to
drop temps safely below record territory by midnight that night.
- GRAND ISLAND
Record Warm Low Latest Forecast
Monday June 17th 74 (1906) 71
- HASTINGS
Record Warm Low Latest Forecast
Monday June 17th 72 (2020/2014/1946) 72
NOTE/REMINDER: in order for a new record warm low/minimum
temperature to become official it has to "survive" the entire
24-hour calendar day (in other words, it is not always based
solely on the early-AM low temp).
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...None.
KS...None.
&&
$$
DISCUSSION...Davis
AVIATION...ADP
CLIMATE...Pfannkuch
Area Forecast Discussion
National Weather Service Goodland KS
948 PM MDT Sun Jun 16 2024
.KEY MESSAGES...
- Temperatures will approach or exceed 100 degrees in many areas
once again on Monday. Strong south winds will affect the
majority of the area Monday afternoon. Sustained winds at 30
to 40 mph and gusts up to 50 mph may create hazardous travel
conditions, especially on west-east routes, such as I-70,
where cross winds will be strongest. Reductions in visibility
associated with blowing dust may exacerbate hazardous travel
conditions.
- Scattered thunderstorms may develop across portions of the
area during the afternoon hours on both Monday and Tuesday.
Isolated severe storms capable of producing large hail and
damaging winds are possible, should storms develop.
&&
.SHORT TERM /THROUGH TUESDAY NIGHT/...
Issued at 222 PM MDT Sun Jun 16 2024
Across the region this afternoon, skies are mainly sunny,
expect for mostly sunny skies across central portions of the
CWA. This is where a meandering frontal boundary resides, with
cumulus starting to pop up along it. Temperatures as of 100 PM
MDT are ranging in the 80s/90s north of boundary into Nebraska.
south of the boundary, 90s. For winds, south of the boundary,
S/SE flow persists with gusts into the 20-25 mph range at times.
Along the boundary, variable winds at times and to the north,
E/NE flow persists.
Weather concerns in the short term period will focus on the
potential for strong to severe storms over portions of the area
during the afternoon/evening hours today through Tuesday. Some
blowing dust is possible Monday afternoon. Increased chances for
rw/trw Tuesday/Tuesday evening could bring about heavy
rainfall/flooding concerns in addition to the threats from
severe storms(wind, hail, etc).
For the remainder of the afternoon hrs into this evening, the
wx threat will focus on where the aforementioned boundary
resides. SPC has increased the Marginal risk in areas
along/north of Highway 36 in NE/KS due to increased
instability/moisture with a more easterly fetch. Between the
HRRR, RAP and NamNest, the NamNest is the most aggressive with
storm potential starting along and north of the front/boundary
around 00z Monday, lifting north and east through 06z. HRRR/RAP
only shows a few isolated cells that amount to very little.
There is decent shear along/ahead of the front thanks to the
easterly flow. Soundings from the HRRR around 21z-22z do show
inverted-v profile and DCape around 1700-1800 j/kg, and SBCape
around 1100-1200j/kg. So if a storm could initiate, it could
grow fairly quickly with potentially all threat mode on the
table, especially damaging winds. With the uncertainty of
formation/coverage, plan on keeping close to previous forecast
(20- 30% pops) for now. The later evening hours do show the
potential for isolated rw/trw potential, so will trend a 20 pop
through the CWA into Monday morning.
Going into Monday, a similar situation to today. Front will
remain the focus for any strong to severe storms. Surface low on
the western side of the front in Colorado will focus increased
southerly flow to areas across NE/KS. Models are hinting at
40-50 mph gust potential, especially in KS. Numbers stay low
enough not to warrant a high wind watch, but need to be
monitored for next forecast issuance. Also, western portions of
Kit Carson/Cheyenne counties into Yuma county in Colorado will
be on the low end for RH during the afternoon hrs. Areal
coverage combined with winds meeting criteria warrants a fire wx
watch(17z Mon-02z Tue) at this time. Local guidance is close to
having patchy blowing dust in the southwest, so have kept a
mention in but decreased coverage from previous forecast.
The rest of the weather concerns will be on the threat for
storms. CAMs are showing best chance from 00z Tuesday onward
with the front lifting into northern tier CWA zones. This will
bring another round of hot conditions, drying lower levels out.
Model soundings show increased DCape values around 2000-2200j/kg
in the 00z Tuesday timeframe, with SBCape values around
1200j/kg. Again like today, the best CAM showing this activity
potential, the NamNest, keeps best chances along/north of the
front, Highway 36 and north. Activity clears quicker than
tonight, allowing for coverage to end by 06z Tuesday.
Both today and Monday will also have high PW values of an inch
plus, mainly in KS/NE, allowing for chances for heavy rainfall
and flooding concerns.
On Tuesday, the low associated with the front is pushed south
due to a nosing ridge from the northern Rockies. This is going
to push the front back south and east as well with it becoming
nearly stationary through the evening hours. This boundary will
interact with a passing 500mb shortwave creating rw/trw chances.
With a persistent feed of moisture into the front area, pops
have increased into the 60-80% range for the evening and
overnight hours. Highest chances east near the front. Excessive
rain along with another chance for strong to severe storms
occurs. This will be focused in the east where the front will
reside. Wind, hail threats will be on tap, along with chances
for heavy rainfall and flash flooding concerns. As with the past
couple days, precip chances do not let up going into the
midweek timeframe.
For temps, another hot day expected on Monday as highs will
range in the upper 90s to low 100s. Going into Tuesday, with a
front over the area, a wider range for highs is expected with
lower 80s in the northwest into the mid 90s in the east-
southeast. Overnight lows tonight will range from the 60s west
of Highway 25, through the lower to mid 70s along and east of
Highway 25. For Monday night, similar to tonight`s numbers, but
some upper 50s may be seen in portions of northeast Colorado.
Going into Tuesday night, cooler with mainly 50s expected. Some
locales east of Highway 25/south of Highway 24 will range into
lower 60s.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
Issued at 1238 PM MDT Sun Jun 16 2024
Generally west-southwesterly flow is anticipated through the
long term period as high pressure is centered over the Mid-
Atlantic coast, slowing eastward progression of upper troughing
over the western CONUS. In this setup, weak shortwaves will keep
daily chances for showers/storms over the area, generally in
the afternoon- evening hours. Wednesday is the exception, with
better chances (to around 60-70%) and more of a time window for
occurrence as chances continue throughout the day. It`s during
the latter part of the work week and into the weekend that the
upper trough starts eastward, eventually shifting flow west-
northwesterly with ridging building in upstream.
Regarding temperatures, Wednesday continues to trend down with
highs topping out in the middle 60s to middle 70s under cloudy
skies and with chances for showers/storms through the day.
Partly cloudy skies, continuing afternoon-evening shower/storm
chances, and a general warming trend to close out the work week
into the weekend, with highs in the 80s Thursday, mid-upper 80s
to low-mid 90s thereafter.
&&
.AVIATION /06Z TAFS THROUGH 06Z TUESDAY/...
Issued at 945 PM MDT Sun Jun 16 2024
GLD: VFR conditions are anticipated to prevail through the TAF
period. A period of LLWS associated with a strong southerly LLJ
(50-60 knot) is expected overnight. At the surface, SE winds at
10-20 knots will veer to the S and increase to 20-35 knots
overnight. Winds will veer to the SW and decrease to 15-25
knots for a period mid-late Monday morning.. then back to the S
and increase to 25-40 knots during the afternoon.. as a
developing lee cyclone tracks northeastward into northeast CO.
MCK: Severe convection invof the MCK terminal weakened and
dissipated ~0245 UTC. VFR conditions are anticipated to prevail
through the TAF period. A period of LLWS associated with a
strong southerly LLJ (~50 knot) is expected overnight. At the
surface, SE winds at 10-20 knots will veer to the S and
increase to 20-30 knots a few hours after sunrise.. further
increasing to 25-40 knots Monday afternoon.. as a developing
lee cyclone tracks northeastward into northeast CO.
&&
.FIRE WEATHER...
Issued at 242 PM MDT Sun Jun 16 2024
Monday, a Fire Weather Watch is in effect for northeast
Colorado from 11 am to 7 pm. Humidity will drop into the 10-15%
range as winds during the afternoon will increase from the south
towards 45 mph. Best criteria will be hit in western portions
of the counties.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...None.
CO...Fire Weather Watch from Monday morning through Monday evening
for COZ252>254.
NE...None.
&&
$$
SHORT TERM...JN
LONG TERM...CC
AVIATION...Vincent
FIRE WEATHER...JN
Area Forecast Discussion
National Weather Service Green Bay WI
648 PM CDT Sun Jun 16 2024
Updated aviation portion for 00Z TAF issuance
.KEY MESSAGES...
- Thunderstorms are possible tonight. A few storms may become
severe, especially over north-central Wisconsin. Large hail,
gusty winds and heavy rainfall will be the main threats.
- Well-above average temperatures are expected through Tuesday.
Heat indices may reach the lower to middle 90s at times Monday
and Tuesday across central, east-central, and portions of far
northeast Wisconsin.
- Periodic thunderstorm chances are possible through much of the
upcoming week. Some strong storms and locally heavy rainfall
may be possible at times.
- There is a marginal risk of excessive rainfall across portions
of north-central and central Wisconsin from tonight through
Tuesday. This may lead to localized flash flooding and rapid
rises in river levels.
&&
.DISCUSSION...
Issued at 445 PM CDT Sun Jun 16 2024
Short Term...Tonight and Monday
Precipitation/Thunderstorm Potential:
This afternoon`s surface analysis had a surface low pressure system
located over central MN with its warm front extending over central
WI. Conditions remained dry under partly to mostly cloudy skies this
afternoon due to capping in place. However, thunderstorms began to
develop at a triple point north of the surface low center in far
northern MN. How these thunderstorms evolve with the movement of the
surface low and its cold front over the next couple of hours will be
the deciding factor for the forecast area to see thunderstorms.
Based on the latest guidance, thunderstorms will remain tethered to
the front and have it progged to sag southeast into north-central WI
this evening. As the front reaches north-central WI, it will enter
an area of 3000 J/kg of MUCAPE, steep mid-level lapse rates, and
deep-layer shear of 30-35 kts. This will produce thunderstorms
capable of large hail, gusty winds, and heavy rainfall. Confidence
for severe storms decreases across the remainder of the forecast
area as the front will move into an area where deep-layer shear is
less supportive for long-lived storms. However, the potential for
showers and thunderstorms will continue across the remainder of the
forecast area through the night, but coverage will become scattered.
Any showers or thunderstorms will also contain heavy rainfall as
PWATs will remain between 1.50 and near 2 inches.
The front is progged to settle somewhere across the central part of
the state Monday morning. Another surface low will then move across
the Central Plains and cause the front to lift north as a warm
front. Additional showers and thunderstorms may develop along the
warm front as a result, but where they develop is still in question
due to the uncertainty where the front will stall over the state
Monday morning. Limited PoPs to chance wording Monday afternoon
because of this.
Temperatures:
Despite the cold front progged to move over the region, an
abnormally warm airmass will remain over the area and keep above
normal temperatures in the forecast. A mild night is expected with
lows ranging from the low 60s to low 70s. Temperatures will climb
into the 80s for most locations on Monday, in addition to dew points
in the middle 60s to low 70s. This will make for another humid day
with heat indices reaching into the low 90s for some locations
across east-central WI Monday afternoon.
Long Term...Monday Night Through Sunday
Models are in good agreement with the placement of a strong upper
high just off the mid-Atlantic states and an upper trough that
extended from south-central Canada to the Pacific Northwest at the
start of the period. The resultant southwest flow into WI will
bring periodic chances for showers and thunderstorms as several
shortwaves move across the area where plenty of moisture to
reside. This upper high eventually weakens and shifts south, thus
allowing for the upper trough to shift east and bring more rain
chances to northeast WI next weekend. Temperatures will run above
normal for much of the upcoming week, including humid conditions
through Wednesday.
Monday night and Tuesday...
A warm front initially over central WI early Monday evening is
forecast to gradually lift north into northern WI late evening and
into Upper MI by daybreak. Expect showers/thunderstorms to
accompany this front, thus highest pops to be placed over northern
WI. PW values of at least 1.5 inches with dew points in the 60s,
could bring locally heavy rain, so will need to watch for
localized flooding across the north. On the flip side, parts of
central and east-central WI may not see any rain, just a warm and
muggy night in the warm sector. Min temperatures to range from
the middle to upper 60s far north/near Lake MI, lower to middle
70s south. Northeast WI to reside in this warm sector on Tuesday
with the warm front to the north and an approaching cold front
into the Upper MS Valley. While no trigger is apparent, increasing
instability with MUCAPES > 2K J/KG could kick off random
thunderstorms during peak heating. The vast majority of the
forecast area will be dry Tuesday and quite warm/humid. Look for
max temperatures to be in the lower 80s along Lake MI, middle to
upper 80s north and upper 80s to lower 90s south.
Tuesday night and Wednesday...
The cold front is progged to slowly move east and reach north-
central to west-central WI by late Tuesday night. Even though the
air mass will not be as unstable due to the loss of daytime
heating, shear will be on the increase (25-35 knots). These
factors, combined with lift from both the cold front and the right
entrance region of the upper jet and hints of a mid-level
shortwave moving northeast into the region all point to another
round of showers and thunderstorms over the northwest half of WI.
Right now, the strongest storms are expected to our west, but will
need to watch the potential of stronger storms in later forecasts.
Eastern WI should stay dry Tuesday night with min temperatures to
range from the lower to middle 60s north-central WI, to the lower
70s east-central WI (cooler near Lake MI). This cold front will
move into northeast WI on Wednesday, but the question becomes how
far south and east this front can get before stalling as it
encounters the mid-Atlantic upper high. As long as this front is
is in our vicinity, we will have chances for additional showers
and storms. More clouds, more rain and a wind shift to the west
behind where the cold front passes will take temperatures down a
bit with readings on Wednesday in the middle to upper 70s north-
central, middle 80s east-central WI (inland from Lake MI).
Wednesday night and Thursday...
The nearly-stalled frontal boundary to remain parked over central
(or southern) WI depending on which model you buy into. Either
way, this boundary will be the focal point for more showers and
storms Wednesday night and Thursday. PW values of 1.5 to 2.0
inches dictate that more heavy rains will be possible and
depending on how much rain had fallen earlier in the week,
flooding concerns (both urban and river) will need to be
monitored. Max temperatures Thursday to be in the lower to middle
70s north/near Lake MI, upper 70s to lower 80s south.
Thursday night and Friday...
The frontal boundary to languish across WI through Friday,
although there a signs that the boundary may lift north a bit into
northern WI on Friday. Have no choice but to keep a chance of
showers/thunderstorms in the forecast for both Thursday night and
Friday. Max temperatures Friday to be in the middle to upper 70s
north/near Lake MI, lower to middle 80s south.
Friday night and Saturday...
Precipitation chances may taper off a bit headed into next
weekend, assuming the frontal boundary does become a warm front
and lifts north of the forecast area. This would leave northeast
WI in the warm sector and with plenty of moisture still over the
region, cannot rule out pop-up showers/thunderstorms, especially
on Saturday. Max temperatures to be in the middle to upper 70s
north/near Lake MI, lower to middle 80s south.
Saturday night and Sunday...
By the latter half of the weekend, the Pacific Northwest upper
trough to have traveled east and is forecast to be moving across
the Upper MS Valley, accompanied by a cold front and more rain
chances. Max temperatures for next Sunday to be in the middle to
upper 70s north/lakeside, upper 70s to lower 80s south.
&&
.AVIATION...for 00Z TAF Issuance
Issued at 647 PM CDT Sun Jun 16 2024
MVFR ceilings will linger at times across central and northern WI
this evening, with VFR conditions expected elsewhere. Models
showing some lower ceilings (MVFR and some IFR) developing across
central and northern WI overnight into Monday morning and possibly
again Monday afternoon. VFR conditions look to prevail for
most/all of the TAF period at GRB/ATW/MTW. We are still
monitoring upstream for shower/storm develop tonight as a cold
front approaches. Storms are having a hard time firing as a cap is
in place holding things in check, along with weaker lapse rates.
HRRR continues to show little to no development until Monday
morning, while the NAMNest and ARW remain on the more aggressive
side showing more widespread activity. Will lean toward the HRRR
at this point and remove the thunder from GRB/ATW/MTW, but keep
the mention for central and northern WI as this is where the
better instability will interact with the front later this evening
into early Monday and at least isolated showers/storms should be
able to develop. An additional round or two of showers and storms
will be possible on Monday as instability will be in place;
however, plenty of unanswered questions remain to when and where
the storms will form as details of where the boundary will end up
and if there will be any outflow boundaries to touch off the
storms. Rather than liter the TAFs with rain/storm chances, have
held off until the picture becomes clearer.
Gusty south winds will continue to diminish late this afternoon
as the better mixing ends closer to sunset. Winds aloft will
promote a few gusts to 20 kts overnight, mainly over eastern WI.
LLWS is expected tonight, mainly from sunset to 10z and southeast
of a Wausau to Wausaukee line, where winds at 2000 ft will remain
near 35 kts. Winds could be a little erratic on Monday due to
overnight boundaries/storms and questions on where the boundary
will stall, but should eventually become south/southeast.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
Beach Hazards Statement until 4 AM CDT Monday for WIZ022-040-050.
&&
$$
DISCUSSION.....Kruk/Kallas
AVIATION.......Bersch
Area Forecast Discussion
National Weather Service Northern Indiana
740 PM EDT Sun Jun 16 2024
.KEY MESSAGES...
- Far northern Indiana and southern Michigan may see showers and
thunderstorms between 8 pm and 4 am. Gusty winds and heavy
rain will be the main concerns.
- An Excessive Heat Watch remains in effect due to an extended
period of hot and humid conditions.
- Widely scattered afternoon and evening thunderstorms are
possible Monday and Tuesday.
&&
.UPDATE...
Issued at 740 PM EDT Sun Jun 16 2024
Potent MCV will lift into southern MI this evening and support
SCT convection given nearly 2000 J/kg MUCAPE. Boundary layer
stabilization will likely prevent any severe wind gusts/strong
convection but latest HRRR has suggested some storms continuing
through much of the overnight in our far northern counties.
Will update PoP`s accordingly. A few showers/storms are firing
along the gust front but HRRR and RAP suggest additional
development behind this front as the MCV passes.
&&
.DISCUSSION...
Issued at 226 PM EDT Sun Jun 16 2024
The main story of the upcoming forecast period remains with hot
and humid conditions already starting today and expected to
further intensify, especially in the second half of the week
with afternoon/evening heat indices in the 95 to 100 degree
range and limited cooling during the overnight hours. Extensive
coordination with surrounding offices as resulted in a
continuation of the Excessive Heat Watch with the reasoning to
be explained below. Regardless of what headlines may or may not
exist, the extended period of heat and humidity will still pose
an issue to those working or playing outdoors, those without
adequate means to cool off (both day and night) and those with
health problems made worse by the hot and humid conditions.
Afternoon temperatures have climbed into the upper 80s with some
potential for far SW areas to still touch 90. A large gradient
in dewpoints was also in place across the area with upper 40s
far NE to mid 60s SW. Overnight lows for tonight and much of the
upcoming week will end up in the lower to middle 70s, making for
rather unpleasant sleeping. While many areas will remain dry
into at least Monday morning, far NW locations may see a chance
for showers and thunderstorms later this evening into the
overnight hours as a well defined mcv heading towards the Quad
Cities, continues to move ENE and force additional showers and
storms across northern IL. SPC upgraded to a slight risk ahead
of this feature with the marginal risk being expanded slightly
to roughly a DeMotte to South Bend to Kalamazoo line. Models are
varying somewhat on the strength of storms as they pass over
Lake Michigan and enter SW Lower MI/far NW Indiana and move ENE.
Some models also expand the precipitation further south to at
least US-6 and maybe even a bit more. For the moment have
limited pops to slgt chc to chc and will defer any further
increases to the evening shift. Gusty winds and heavy rain will
be the main concerns.
While the hot and muggy conditions are fairly straight forward,
finer details in cloud cover, chances for showers/storms and
mixing out of dewpoints with drying ground conditions lead to
challenges in upgrading the watch to a Heat Advisory or
Excessive Heat Warning. The greatest concerns for the heat still
exist moreso Wednesday and beyond as the cumulative effects of
the heat as well as lack of rain chances all lead to greater
impacts. Weak disturbances and subtle forcing mechanisms could
help spark widely scattered showers and thunderstorms during the
afternoon and evening hours of Monday and Tuesday. One
mechanism could be any boundaries that may be left over from the
convection tonight. While it will be unstable and generally
uncapped, hard to assign more than a slgt chc to maybe chc of
convection at this point. Any storms that manage to form will
not move much and with the moist conditions will produce very
heavy rain and maybe locally gusty winds. Models do key in on a
disturbance working north Monday night that may help increase
chances for showers and storms, but think models may be overdone
somewhat with general consensus of offices being to keep pops
silent or slgt.
Chances for showers and thunderstorms may increase over the
weekend as the ridge axis orients more west to east and sinks
some. Best chances may exist Sunday but if these don`t pan out,
then the potentially dangerous heat will persist.
&&
.AVIATION /00Z TAFS THROUGH 00Z TUESDAY/...
Issued at 740 PM EDT Sun Jun 16 2024
Gust front associated with convection over IL will support some
isolated showers/storms and gusty winds at KSBN during the next
few hours. Additional development is also possible as the parent
MCV lifts into MI and have therefore added a VCTS mention.
Thunder coverage will likely remain low though and not expecting
anything at KFWA. Otherwise VFR conditions expected. Additional
isolated storms are possible Mon afternoon but confidence is far
too low to mention in the TAF at this point.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...Excessive Heat Watch from Monday morning through Friday
evening for INZ005>009-014-017-018-024>027-032>034-104-
116-204-216.
Air Quality Alert until midnight EDT tonight for INZ020.
OH...Excessive Heat Watch from Monday morning through Friday
evening for OHZ001-002-004-005-015-016-024-025.
MI...Excessive Heat Watch from Monday morning through Friday
evening for MIZ078>081-177-277.
Air Quality Alert from midnight tonight to midnight EDT Monday
night for MIZ078-177-277.
MARINE...None.
&&
$$
UPDATE...AGD
DISCUSSION...Fisher
AVIATION...AGD
Area Forecast Discussion
National Weather Service Marquette MI
758 PM EDT Sun Jun 16 2024
.KEY MESSAGES...
- Possible strong to severe thunderstorms this evening and
tonight. Large hail, damaging winds, frequent lightning, and
heavy downpours will be possible.
- Possible strong to severe thunderstorms Monday and possibly
Tuesday night/Wednesday.
- Very warm early next week, with frequent chances for showers and
thunderstorms throughout.
&&
.SHORT TERM /THROUGH TONIGHT/...
Issued at 142 PM EDT Sun Jun 16 2024
Rain showers continue to lift through the forecast area
atop a very moist surface layer. As of publishing this AFD,
rain showers were spread across the eastern and central UP with
dewpoints in the mid 50s to low 60s across the region.
Destabilization ahead of mid-level ridging building into the
west may support additional shower development, or some
thunderstorms in this afternoon across the east half before they
exit into Ontario. Severe weather is not expected in this wave.
The atmosphere will further destabilize ahead of a cold front/low
pressing eastward through Minnesota this afternoon. Guidance
continues to suggest this will result in shower and thunderstorm
development with quick upscale growth into an MCS, which will
progress east-southeast into Wisconsin and Upper Michigan this
evening. The strong destabilization in the pre-frontal space
stretching from Wisconsin into the U.P. is characterized by 2000-
3000 j/kg of elevated CAPE. While the region where this will develop
is expecting much stronger deep layer shear, guidance over Lake
Superior generally suggests around 30-40kts of 0-6km bulk shear
oriented off the boundary, suggesting the linear complex may survive
the transit and move into Upper Michigan. With DCAPE 500-1000j/kg
and increasing mid-level lapse rates to around 8C/km, strong to
severe thunderstorms will be possible if so. Main hazards will be
large hail up to 1 inch in diameter, strong or damaging winds
upwards of 60mph, frequent lightning, and heavy rain upwards of 1+
inches this evening. Primary risk areas will be across the
west/central, but some guidance packages, namely the RAP, ARW and
FV3, suggests the thunderstorms could hold together as they move
into the east half around midnight.
A warm and muggy night is projected after the convection ends. As
temps begin to cool, patchy dense fog may develop overnight.
Overnight lows and dewpoints are likely to remain in low to mid 60s
for most of the forecast area.
&&
.LONG TERM /MONDAY THROUGH SUNDAY/...
Issued at 332 PM EDT Sun Jun 16 2024
The active weather pattern doesn`t look like it will relent over the
rest of this week as troughing deepens over the western U.S. and
ridging amplifies over the Eastern Seaboard early this week. This
keeps us on tap for very warm and moist conditions Monday through
Tuesday, before the troughing pattern moves east and brings cooler
temperatures across our area Wednesday into Thursday; be careful if
working outside Tuesday, as the hot and humid weather could cause
heat exhaustion and heat stroke! Meanwhile, expect showers and
thunderstorms chances to continue across Upper Michigan throughout
the rest of this week into next weekend, with a few strong to severe
storms being possible Monday and Tuesday night/Wednesday. The severe
weather threat, should any occur, would be hail, winds, and repeated
heavy rainfall causing ponding. Additional details follow below.
Monday starts out with a band of showers and thunderstorms making
there way from west to east across the U.P. during the morning to
early afternoon hours due to a cool front kicking-off the
convection. While most of the CAMs show the convection weakening
with time, the most recent extended HRRR shows the convection
becoming quite vigorous in a couple of the cells. With 0-6 km bulk
shear being around 30 knots and MUCAPEs around 250-1000 J/kg across
the area, we could see a few strong to marginally severe
thunderstorms in this band of convection Monday morning through
early afternoon, with the primary threat being hail and the
secondary threat being winds. However, with cloud cover remaining
over the area throughout the day, the severe weather potential is
limited. Another band of showers and thunderstorms could move into
the western U.P. late in the afternoon Monday. With MUCAPE values
and shear being higher, the severe weather threat is likewise higher
with this round of showers and storms, with hail and winds being an
equal threat. In addition, these storms could train over the same
area that received the rainfall from the previous round during the
morning hours. With PWATs being about 1.50 inches (near the 90th
percentile of modeled climatology), heavy rainfall is possible. When
combined with the training aspect of these storms, we could see some
isolated ponding in the poor drainage areas. What may prevent the
severe weather, though, is if the better convection ends up further
south in Wisconsin. However, it appears that most of the CAMs bring
some strong to severe convection over us now during the late
afternoon hours over the west and central. Moving into the early
night hours Monday, the convection could keep going into the eastern
U.P. and Lake Superior (such as seen in the NAMNest). However, with
the loss of the daytime heating and weakening of the bulk shear, its
more likely that we will see the showers and storms weaken as they
move into the eastern U.P./Lake Superior Monday evening. As we
continue past midnight, expect the shower and thunderstorm chances
dwindle and move northwards as warm frontogenesis forces the
convection towards northern Ontario, bringing drier weather across
our area by Tuesday morning.
Expect sunny skies, muggy conditions, and probably the warmest
weather of the summer yet come Tuesday as we sit directly underneath
the warm sector of a low lifting through the Lake Winnipeg area.
Tuesday could also be fairly breezy, with the ECMWF EFI highlighting
unusually high southerly winds throughout the day. However, with a
low-level cap in place, it may be difficult to get the winds to gust
much more than 30 mph, save for the downslope areas near Lake
Superior where mixing could be locally enhanced. Expect temperatures
to get into the high 80s to low 90s during the afternoon hours, with
dewpoints reaching up into the low 70s. This will cause the heat
index to get into the 90s across much of the area, with a spot or
two possibly flirting with 100! Therefore, be sure to take lots of
water breaks if you are outside Tuesday, as heat exhaustion and heat
stroke are much quicker and easier to occur than normal; hopefully
the breezy southerly winds will provide a little relief from the
stifling hot and humid weather.
Moving into Tuesday night, showers and thunderstorms slowly move
back over us as the troughing pattern over the western U.S. slowly
trudges eastwards into the Plain states and weakens. We could see
some strong to severe thunderstorms yet again along the frontal
boundary as MUCAPEs could exceed 1000 J/kg and 0-6 km bulk shears
approach 40 to 50 knots. In addition, expect heavy rainfall, with
ensembles showing PWATs near the max of climatology/around 2 inches!
With storms possibly training ahead of the frontal boundary, some
ponding of water in poor drainage areas is certainly possible; while
the chance is low (<5%), we could also see other flash flooding
concerns such as ponding in better drainage areas and swollen creek
beds. As shortwaves continue along the frontal boundary during the
middle of this week, expect rain shower and thunderstorm chances to
continue. Weak high pressure looks to move into the Northern Plains
and northern Ontario along Lake Superior near the back-end of this
week, forcing most of the rain chances more so to the southern parts
of our area. Going into next weekend, a low pressure lifting off of
the Colorado Rockies and an upper level Clipper low look to phase
with each other over the Upper Midwest. This will bring additional
showers and thunderstorms across our area via warm frontogenesis
through at least the first half of next weekend.
&&
.AVIATION /00Z TAFS THROUGH 00Z TUESDAY/...
Issued at 724 PM EDT Sun Jun 16 2024
After a break in the showers and thunderstorms this afternoon
expect more showers and thunderstorms to pop up this evening,
although timing and extent of coverage of the convection will be
difficult to predict. It looks like IWD will be terminal most
likely to be impacted by showers/t-storms this evening as it
will be closer to the more unstable air mass to the south.
Some of these storms could be capable of large hail, damaging
winds, heavy downpours, and frequent lightning. After the
thunderstorm activity ends in the overnight hours, guidance is
keen on fog/mist developing, which may reduce visibilities at
each terminal to MVFR or potentially IFR. MVFR ceilings will
likely prevail at the terminals through much of the forecast
period. More showers and storms could redevelop on Monday.
&&
.MARINE...
Issued at 332 PM EDT Sun Jun 16 2024
Southerly winds of 20 to 25 knots over the eastern lake this
afternoon decrease to 20 knots or less by this evening as a
shortwave lifts from Lake Superior into northern Ontario. The light
winds continue through Monday before increasing from the south to 20
to 25 knots over the eastern half of the lake Tuesday. In addition,
expect some downsloping winds near the southern shoreline to gust up
to 20 to 30 knots, with a few gale force gusts up to 35 knots being
possible, particularly in the nearshores from Marquette to just west
of Whitefish Point. The winds weaken back down to 20 knots or less
again by Tuesday night/Wednesday morning as the frontal boundary
just west of the area finally begins moving across the lake. The
light winds look to continue through the rest of the week as weak
high pressure ridging settles over northern Ontario.
Showers and storms are expected across the lake from this afternoon
through Wednesday. Some strong to severe storms are possible during
this time, with hail and wind being the main threats.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
Beach Hazards Statement until 10 PM EDT this evening for
MIZ014.
Lake Superior...
None.
Lake Michigan...
None.
&&
$$
SHORT TERM...JTP
LONG TERM...TAP
AVIATION...Voss
MARINE...TAP
Area Forecast Discussion
National Weather Service San Angelo TX
617 PM CDT Sun Jun 16 2024
...New AVIATION...
.SHORT TERM...
(This evening through Monday)
Issued at 142 PM CDT Sun Jun 16 2024
Most of the state of Texas is between the 500mb subtropical ridge
across northwest Mexico and the 500mb ridge along the middle
Atlantic United States coastline. This will provide a shear axis
across the central and eastern portions of the state tonight into
Monday. The question tonight into early Mon morning is whether any
convection will develop across west Texas tonight and propagate into
portions of west central Texas similar to last night. The latest
HRRR does prog some thunderstorms developing across west Texas
this evening and outflow from this convection may provide a focus
for showers and thunderstorms to develop across portions of the
northern Edwards Plateau late tonight into early Monday morning.
Will mention a slight chance of showers and thunderstorms across
southwest portions of the CWA tonight into early Monday as a
result. Breezy conditions are expected to prevail tonight into
Monday as the pressure gradient remains relatively strong across
west Texas. Temperatures will continue to remain above normal
Monday afternoon.
&&
.LONG TERM...
(Monday night through next Sunday)
Issued at 157 PM CDT Sun Jun 16 2024
The focus for the long term continues to be the possibility of
heavy rainfall across parts of the area in the Wednesday through
Friday timeframe but especially on Thursday. Mainly dry conditions
will persist on Tuesday and most of Wednesday although we could
see some scattered showers and thunderstorms begin to spread into
our southeastern counties during the afternoon on Wednesday.
We continue to monitor a tropical disturbance in the southwestern
Gulf of Mexico which now has a 70% chance of developing into a
tropical depression or tropical storm. Whatever ultimately
develops will likely move across northern Mexico or south Texas
around the middle of the week. Deep easterly flow around this
system will advect abundant Gulf moisture into the region, with
precipitable water values increasing to as high 1.8-2.0 inches.
More widespread showers and thunderstorms are possible on
Thursday especially south of I-20 as this tropical moisture begins
to spread into the region. There are still differences amongst
the operational guidance regarding rainfall amounts- the ECMWF
continues to hold a stronger ridge over the area shunting most of
the tropical moisture to the south while the GFS shows upper
level troughing over the area and thus higher rainfall amounts.
Given the uncertainty in the ultimate evolution/track of the Gulf
system and subsequent rainfall amounts for our area will continue
to stick with the model blend for now which shows a 40-50% chance
of PoPs in the Thursday/Friday time frame. Please stay tuned as
we get a better handle on this potential Gulf of Mexico
disturbance and continue to refine rainfall amounts.
With the increasing rain chances and expected cloud cover
temperatures will be much cooler after Tuesday. Highs on Wednesday
though Friday will be mainly in the 80s, with overnight lows in
the 60s. Drier and warmer conditions will return for next weekend
as upper level ridging builds back into the region.
&&
.AVIATION...
(00Z TAFS)
Issued at 547 PM CDT Sun Jun 16 2024
Gusty winds around 18 to 25 kts kts will continue on and off
through the evening and overnight hours. Low clouds are expected
to move into KJCT, KSOA, and KBBD late tonight and early tomorrow,
bringing MVFR CIGs. Low clouds should move out by the mid to late
morning, leaving VFR conditions with breezy southeast winds.
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 74 94 73 92 / 0 0 0 0
San Angelo 74 99 74 98 / 0 0 0 0
Junction 74 97 74 95 / 0 0 0 0
Brownwood 74 91 73 89 / 0 0 0 0
Sweetwater 74 97 73 94 / 0 0 0 0
Ozona 73 96 72 95 / 20 20 0 0
Brady 73 92 73 89 / 0 0 0 0
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SHORT TERM...61
LONG TERM....42
AVIATION...AP
Area Forecast Discussion
National Weather Service Salt Lake City UT
339 PM MDT Sun Jun 16 2024
.SYNOPSIS...A strong cold front will cross the region Monday,
bringing a much colder airmass to the area for Tuesday.
Temperatures will quickly moderate midweek, with another period of
very hot temperatures by Sunday.
&&
.SHORT TERM (Through 00Z Wednesday)...The Beehive State is in for
a bit of a roller coaster ride, with the next 7 days including
the threat of freezing conditions in the Wasatch Back...to near
100 again by next Sunday across the Wasatch Front. So we`ll be
running the gamut here over the next week.
Afternoon upper air and satellite analysis indicates a longwave
trough is shifting south and east into the Pacific Northwest. This
trough is associated with an anomalously cold airmass...around the
lowest in the EPS climatology for this time of year. The
associated cold front will approach the Utah/Idaho border Monday
morning, blasting through the state and reaching southern Utah by
the first half of Monday night.
While the global models have been relatively dry with the frontal
passage, CAMS nearly universally depict convection during the
afternoon and evening associated with the strongest forcing,
mainly near and north Salt Lake City. Given the dry subcloud
environment, suspect a line of high-based convection with
microbursts mixing down stronger winds will be the predominant
mode during the afternoon and evening. Something to monitor going
forward.
Guidance still suggesting winds are likely to remain below wind
advisory criteria in most locations, with gusts to 45 mph or so
for an hour to two hours. It should be noted however that the
latest run of the HRRR has become quite bullish with wind gusts
with the front Monday evening into MOnday night, with widespread
gusts in excess of 60 mph across Washington County and perhaps
downsloping into Castle Country and the western Uinta Basin. HREF
probabilities for the Black Ridge Canyon area are approaching
100% for gusts over 55 mph. It should be noted that the high res
guidance notoriously overforecasts strong winds in this area...but
future shifts will need to monitor for a potential High Wind
Watch. For the SR-10 corridor in Castle Country...without jet
support...winds have a difficult time shifting off the terrain.
This will be another area to monitor for future shifts.
As far as the very cold temperatures, guidance continues to show
high probabilities of freezing temperatures across the Wasatch
Back...and thus have issued a Freeze Watch for Monday night into
Tuesday morning. Patchy frost will be possible across the Wasatch
Back, Cache Valley, Sanpete Valley and Rush Valley.
Highs on Tuesday will be well below average across much of the
region.
.LONG TERM (After 00Z Wednesday), Issued 403 AM MDT... In the
wake of Monday`s frontal passage, a much cooler and more stable
airmass will temporarily reside across the forecast area. Clearing
skies Monday night along with this much colder airmass will allow
min temps to fall near freezing across portions of the Wasatch
Back and potentially the Cache Valley as well, and Freeze
headlines may be needed if this trend holds. Max temperatures
Tuesday afternoon will run nearly 15F below climo across northern
Utah, where highs will struggle to reach the 70F mark across the
northern valleys. Further south temperatures will run closer to
10F below climo, with upper 80s to low 90s across the lower
elevations of southern Utah.
A mean trough axis will remain situated to the west of the forecast
area throughout the middle to latter portion of next week, leaving
the forecast area under a mild and dry southerly flow aloft. Max
temperatures will quickly rebound to near climo Wednesday, then
continue to trend a few degrees warmer each day from Thursday into
next weekend. Additionally, moisture being pulled into the southern
and central Rockies may gradually spread west during the latter
portion of next week, allowing for a small chance for showers and
thunderstorms mainly over the far eastern CWA.
&&
.AVIATION...KSLC...NW winds expected to linger into the evening,
flipping SE between ~05Z-07Z Mon. SE winds then persist, with an
early switch back NW ~13Z-15Z Mon as a cold front gradually sinks
through the region. Tightening gradient will result in increasingly
gusty NW winds throughout the daytime, generally in the 25kt to 35kt
range. Winds will gradually relax late Monday evening into the
overnight hours, with NW direction favored to persist. Precipitation
chances low (around 20%), but best chance noted from ~21z Mon to
~03Z Tue. Given high-based nature, any convection would be capable
of further gusty and erratic outflow winds.
.REST OF UTAH AND SOUTHWEST WYOMING...Winds expected to lighten up
and largely follow a diurnally normal pattern overnight. From Mon
morning on through the afternoon, a cold front will sink southward
through N UT and SW WY terminals, reaching S UT terminals by later
Mon evening. At northern terminals, NW winds become favored
following frontal passage, and gusty conditions set in during the
daytime hours (generally in the 25kt to 35kt range). Additionally, a
low chance (around 20%) of high-based convection is noted at
northern terminals during the afternoon. At southern terminals,
gusty SW prefrontal winds develop during the day, with at least some
potential noted for patchy smoke related haze to advect in from
fires in the SW CONUS. Winds at southern terminals flip N to NW
abruptly later Mon evening following frontal passage.
&&
.FIRE WEATHER...Critical fire weather conditions continue across
southern Utah this afternoon, with multiple sites seeing winds in
excess of 30 mph with humidities at or below 15%. Expect another
night of poor recoveries across southern Utah. A strong cold front
will cross the state Monday into Monday night. Ahead of this
front, expect gusty southerly winds across southern Utah with very
low humidities. The front will bring an abrupt change in wind
direction to the north to northwest...remaining strong and gusty
for several hours behind the front. While temperatures will be
considerably cooler in many locations Tuesday, humidities will not
rebound much across southern Utah. Another round of critical fire
weather conditions is possible Thursday into Friday across
southern Utah as southwest flow increases ahead of the next
system. Mid-level moisture may increase by Friday, spreading west
from the Gulf of Mexico, which may bring lightning to areas that
have been very dry for a considerable period of time across
southern Utah. Something to watch moving forward.
&&
.SLC WATCHES/WARNINGS/ADVISORIES...
UT...Freeze Watch from Monday evening through Tuesday morning for
UTZ108.
Red Flag Warning until 9 PM MDT Monday for UTZ495-496.
Red Flag Warning until 3 AM MDT Tuesday for UTZ498.
Red Flag Warning until midnight MDT Monday night for UTZ497.
WY...None.
&&
$$
Kruse/Warthen/Seaman
For more information from NOAA`s National Weather Service visit...
http://weather.gov/saltlakecity