Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 06/04/24
Area Forecast Discussion
National Weather Service La Crosse WI
1048 PM CDT Mon Jun 3 2024
.KEY MESSAGES...
- Showers and storms continue through the evening across
portions of northeast Iowa and southwestern Wisconsin. Small
hail and locally heavy rainfall are the primary threats with
these storms.
- Additional showers and storms will progress through the region
Tuesday evening bringing rainfall amounts of 0.5 to 1" with
locally higher amounts possible. An isolated severe storm or
two are possible across portions of southeast Minnesota and
northeast Iowa.
- Below normal temperatures with shower chances are expected
into the latter half of the week with highs holding in the 70s
for much of the region. Gusty winds to 30-40 mph are possible
during the afternoon Wednesday and Thursday.
&&
.DISCUSSION...
Issued at 253 PM CDT Mon Jun 3 2024
* REST OF THIS AFTERNOON/EVENING: Showers and Storms across
Northeast Iowa, Southwest Wisconsin
Currently, showers and storms have developed across portions of
northeast Iowa along a residual boundary resulting from clearing
skies further west allowing for differential heating to take place.
MLCAPE values in this region are around 1500-2000 J/kg certainly
plenty of fuel to keep storms going into southwestern Wisconsin.
However, with shear profiles being fairly unfavorable (20-30 kts of
bulk shear), resulting in fairly messy convective development with
storms struggling to maintain any organized updraft. As a result,
primary threats with storms moving through will be locally heavy
rain and hail (up to quarter sized) with initial updraft
development. Storms will progress eastbound and should push east of
the local area by 7-8pm at the latest. With prior rainfall across
portions of northeast Iowa and southwest Wisconsin, may have to
watch for some localized flooding concerns with already saturated
soils.
* TUESDAY/TUESDAY NIGHT: Showers and Storms, Additional Robust
Rainfall Amounts With Some Severe Potential
Tuesday will feature an amplified upper-level trough progressing
through the region with an accompanying surface cold front. Earlier
in the day, moisture advection will work its way into the region
with southerly surface flow allowing dewpoints to reach well into
the 60s for the afternoon with precipitable waters reaching to
around 1.5" to 1.75" shown in the 03.00z HREF by late afternoon.
With the increased moisture expecting fairly respectable instability
with values of MLCAPE of around 1500 J/kg into the evening in the
03.15z. While the morning and much of the afternoon should
remain mostly dry, cannot rule out a shower or two ahead of a
subtle warm front that will push its way north into the region
ahead of the aforementioned cold front.
Getting into the evening hours, the recent CAMS push convection into
our region from west to east along the incoming cold front.
Currently, the 03.09z RAP really diminishes instability as the
cold front pushes eastbound with only around 750-1000 J/kg of
MLCAPE for the linear convection to work with as it pushes east
of the Mississippi River. This combined with fairly marginal
shear to work with as much of it is behind the boundary. This is
reflected fairly well in the 03.00z joint CAPE/shear probs in
the HREF which has very low probabilities (5-15% chance) for
both 500 J/kg and 30 kts of bulk shear or greater. As a result,
expecting minimal severe potential with low-mid level in model
soundings only reaching to around 35-40 kts. So would be the
kind of setup where a few gusts approach 50-55 mph or a quarter
sized hail stone are possible and would be isolated in nature.
This would be more likely to occur at onset of convection moving
into the local area across portions southeast Minnesota and
northeast Iowa where SPC has a slight risk (Threat level 2 of
5).
Otherwise, with the aforementioned ample moisture and warm cloud
depths of around 3500m shown in the 03.12z NAM/GFS. Expecting there
could be some fairly efficient rainfall with the line of showers and
storms that pushes through. Currently, 03.12z GEFS/EC ensemble show
very good agreement (70-90% chance) on rainfall amounts of 0.5" or
greater, with amounts of 1" or greater certainly possible (20-40%
chance). The 03.12z HREF is in fairly similar agreement with roughly
similar probabilities for 1" or greater. Consequently, river
locations may want to be alert to potential rises in light of some
of the prior rainfall that has fallen this week.
* WEDNESDAY INTO THE WEEKEND: Mild Temperatures and Breezy Late Week
With Shower Chances
As we get through Tuesday, a broad scale upper-level trough will
entrench itself over the eastern half of the CONUS with a broad
ridge situated over the west subjecting our region to northwest
cyclonic flow on the western periphery of the trough. As a result,
expecting temperatures to trend below normal through the end of the
week which essentially means highs persisting in the upper 60s to
upper 70s this time of year. Current deterministic soundings show
weak instability in the low levels each afternoon suggesting some
cyclonic cumulus and spotty showers, particularly the further
northeast you get. Additionally, with increasing low/mid-level wind
fields increasing on the western flank of the synoptic trough and
diurnal mixing to aid momentum transfer to the surface, would expect
to see some increase in wind gusts late week. This would primarily
be during the afternoon with the 03.06z EC ensemble showing
respectable probabilities (40-70% chance) for wind gusts approaching
40 mph, particularly in more open areas across southeast Minnesota
and northeast Iowa. Some subtle ridging Friday into Saturday may
help moderate temperatures closer to normal ahead of a potential
secondary trough ejection where guidance still tends to deviate
in its position and timing.
&&
.AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/...
Issued at 1047 PM CDT Mon Jun 3 2024
Due to the combination of light winds and low level moisture in
the valley, kept a broken IFR cloud deck and BCFG for KLSE
between 04.10z and 04.13z.
Used the CAMS to time the showers and storms late Tuesday
afternoon and evening. Currently have showers and storms in the
KRST TAF between 04.01z and 04.04z and for the KLSE TAF between
04.03z and 04.06z.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
IA...None.
&&
$$
DISCUSSION...Naylor
AVIATION...Boyne
Area Forecast Discussion
National Weather Service Bismarck ND
1004 PM CDT Mon Jun 3 2024
.KEY MESSAGES...
- Showers and thunderstorms tonight through Tuesday morning. A
few storms could be severe this evening.
- Strong northwest winds Tuesday through Thursday.
- Seasonable temperatures expected through the week with
slightly warmer temperatures possible late in the week.
&&
.UPDATE...
Issued at 953 PM CDT Mon Jun 3 2024
Broad area of rain stretches from north to south through central
and parts of western North Dakota, which continues to move to
the east-northeast. Some thunderstorms continue over southern
portions of the area where modest instability remains, with a
few lightning flashes noted here and there further north.
Further west, a line of showers with a few lighting flashes
continues to move east through eastern Montana affiliated with
an approaching cold front. This should move into western North
Dakota during the next hour, though some additional showers are
starting to fill in a bit over northwest North Dakota between
the systems. All this activity will then push towards the east
overnight, with chances lingering over central North Dakota into
Tuesday morning.
UPDATE
Issued at 704 PM CDT Mon Jun 3 2024
Line of convection has developed over southwest North Dakota
right along the corridor of stronger CAPE values (~1000 J/Kg),
though storms are now starting to push to the east of the higher
values. Latest guidance tries to pull the core of elevated
instability east, but appears that the storms may continue to
push ahead of this. We did have one severe event (quarter size
hail) over Adams County with our strongest storm, but that has
since weakened, and the strongest storm in the area remains
over Perkins County, SD. Would not be surprised to see a few
more storms increase in intensity and become strong with gusts
to 50 mph and small hail, but the severe risk remains low,
though can`t be ruled out given the marginal shear in place. At
this time, the Perkins County storm is the one to keep the
closest eye on as it gradually makes its way northeast towards
our area. Current area of storms will continue to move east,
with additional showers/storms later tonight affiliated with a
cold front now pushing through central into eastern Montana make
their way east.
&&
.DISCUSSION...
Issued at 203 PM CDT Mon Jun 3 2024
A potent storm system will track from the Pacific North west
this afternoon, across the Northern Rockies and close off into
a closed upper low as it moves into the southern Canadian
Prairie Provinces by Tuesday. Strong upper level divergence is
expected to develop over western ND this afternoon, while
increasing low level convergence develops along the
Montana/North Dakota border. The latest satellite imagery shows
an increasing cumulus field over southeast Montana and into the
western Dakotas. As far as potential convection this afternoon
and evening, not much has changed from this morning. Modest
500-1000 J/Kg MUCape with 30-40 knots of bulk shear will provide
the potential for a few strong to severe storms. As for the
storm mode, starting around 21 UTC the bulk shear is pretty much
perpendicular to a thermal trough the looks to develop along
the MT state line. A more stable airmass on satellite looks to
be situated from around Beach northward, and also looks to be
lifting to the north. Cumulus is building southwest and
expected to continue building northward this afternoon. This
could set the stage for a few discrete cells developing this
afternoon. Current CIN is pretty high over southwest into south
central ND, but you can see a min in the CIN poking into
southeast MT that should lift northward late this afternoon. The
SPC HRRR does show that CIN then increases quickly early this
evening. By this time the shear backs to the southwest and
trends to more parallel to the trough, but not completely, so
you could have a mixed mode of convection with a trend towards
a mixed or linear mode later in the evening and overnight as the
forcing increases with the approaching. However, CIN also
increased and elevated convection would be favored. Therefore
the best bet for strong to severe storms looks to be late
afternoon the southwest and possibly north into the west
central, depending on how the more stable atmosphere in
northwest ND erodes. All hazards would be possible here but the
window appears small. A few NUCAPS soundings over the Mondak
regions shows around 2000 J/KG cape in near Baker MT, but a nice
bump of mid level warming providing a nice C cap. A Buffalo SD
sounding showed a much more unstable atmosphere with MUCAPE
above 3000 J/KG but also with a cap, albeit a not as strong.
Both these soundings may be a bit warm for surface temperatures
as well. A sounding north of Dickinson shows a more modest 1000
J/KG MUCape but was less capped than those soundings to the
west. Not much vertical development of any CU at this time in
southeast Montana, but possibly will develop more with heating
and as cumulus meanders a bit farther east. Low level flow over
ND is more south to southeast, ahead of the thermal trough,
potentially yielding a longer residence time of any developing
updrafts. Will certainly need to monitor. As for the threats, we
mentioned all three, the tornado threat we think would be quite
early on in the convective development with strong surface
heating and some low level shear present. Large hail look to be
a threat if we could get a rotating mesocyclone. Otherwise, CAPE
in our local are seems less favorable for large hail compared
to farther south into South Dakota. Thus quarter size seems
reasonable. The wind threat would be more favored later on if we
get some liner convection or bowing segments. But also here,
the later we get into the evening, the more likely convection
would be elevated. Thus 60 mph also seems reasonable. The strong
shortwave will keep at least a small threat of strong winds as
convection moves into the central part of the state, but
overall, we think the severe potential would be quite a bit less
later and farther east, especially after around 10 PM and east
of the Highway 83 corridor.
Overall we think the NBM probabilities of convection may be a
bit high, especially this afternoon and early evening. However,
showers and thunderstorms should become more widespread (but not
severe hopefully) as we go through the late evening and
overnight hours.
Over central ND, ahead of the convection we could see some fog
develop again from the James River Valley to the Turtle
Mountains. However uncertainty in this is pretty high so we did
not include fog at this time. Late tonight and into Tuesday we
could also see some fog post convection but again, too uncertain
for any one area.
Showers and thunderstorms will exit the area on Tuesday with a
strong westerly surface flow moving in from the west. Tuesday
looks to be breezy over western North Dakota.
Wednesday, however, looks to be the most likely day for wind
highlights as a strong northwest surface flow develops beneath
the Canadian upper level low. At this time it looks like a wind
advisory will likely be needed for at least northern and western
portions of the forecast area, and possibly all of western and
central ND. The ECMWF continues to show a pretty good signal (80
percent probability) for significant winds and gusts over much
of the forecast area, with the 90 percent probability
approaching the northwest. With a strong upper jet in the area,
a case could be made for possible HWW criteria winds given the
strength of the winds aloft. There does seem to be quite a bit
of low and mid level cloudiness around and some upward motion
limiting the wind potential. Will need to monitor this as well.
Wind potential shifts into eastern ND on Wednesday, but breezy
to windy conditions could be felt over the central portion of
the state.
Beyond Wednesday we look to dry out with temperatures possibly
showing a small warming trend as we head towards the weekend.
Mid week will be more seasonable with 60s and 70s. Late in the
weekend into next week the warming trend could continue but high
NBM ensemble high temperature spreads increase so confidence in
anything warmer is not high at this time.
&&
.AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/...
Issued at 704 PM CDT Mon Jun 3 2024
Showers and thunderstorms over western North Dakota will
continue to spread east this evening, with additional
showers/storms passing through overnight. This will bring
periods of MVFR/IFR visibility. In addition, small hail and
gusty winds will be possible with the storms. The storms will
exit from west to east late tonight into Tuesday morning, but
westerly winds will be on the increase behind a cold front,
possibly gusting to around 35 kts.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
UPDATE...JJS
DISCUSSION...TWH
AVIATION...JJS
Area Forecast Discussion
National Weather Service Dodge City KS
1040 PM CDT Mon Jun 3 2024
...Updated Aviation...
.KEY MESSAGES...
- Areas of fog, possibly dense, early Tuesday morning as higher
dewpoints push back north into southwest Kansas on southeast
winds.
- Thunderstorm chances minimal through Thursday as the main
polar front remains south of southwestern Kansas.
- A wetter/stormier pattern is likely beginning Friday evening
going into the upcoming weekend with severe weather and heavy
rainfall potential increasing.
&&
.SHORT TERM /THROUGH TUESDAY NIGHT/...
Issued at 339 PM CDT Mon Jun 3 2024
The large mesoscale convective system (MCS) earlier this morning
left in its wake a cooler, more stable airmass across much of
Kansas. The focus for surface-based severe local storms will be to
the south of our southwest Kansas area of responsibility...down into
the eastern Texas Panhandle and west central/southwestern Oklahoma
where low level convergence will be enhanced from the MCS`s remnant
outflow boundary.
For our area tonight early Tuesday morning, we will be looking at
return southeasterly flow in the low levels, including the surface,
which will draw northward higher dewpoints...as high as the upper
60s to around 70 across the south central Kansas counties (generally
east and southeast of Dodge City). Elsewhere, mid 60s dewpoints will
be common. The slight upslope component to the surface winds and
temperatures falling into the upper 60s, we will likely see the
development of low stratus and/or fog. The latest official forecast
will follow closely the 12Z HREF means/probabilities for fog as the
HREF has fairly widespread 30-40% probabilities of 1/4 mile or less
visibility centered across the central portions of our forecast
area. Each run of the HRRR model that goes out to 12Z Tuesday shows
a fairly consistent signal of 1/4 mile visibility as well. The next
shift will need to continue to monitor obs, satellite, and hourly
HRRR trends for possible dense fog headline, but we will hold off on
any such issuance this ESTF cycle. Something else we will need to
monitor is late nocturnal convection developing in an increasingly
convergent low level flow field ahead of a frontal boundary across
northwestern Kansas and southwestern Nebraska. There is slight
signal in thunderstorm activity developing across northwest Kansas
and clipping the I-70 corridor around daybreak or after, but the
prospects of a large MCS like the past couple mornings are very
small.
The rest of the Short Term forecast is fairly straight-forward with
rather benign sensible weather as a cold front pushes southeast
during the day Tuesday, pushing any thunderstorm risk southeast of
our forecast area, with the exception, perhaps, of Barber
County/vicinity.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
Issued at 339 PM CDT Mon Jun 3 2024
The early portion of the Long Term period...Wednesday and
Thursday...will be fairly quiet with convective activity focused
across the Southern Plains as a formidable upper tropospheric jet
streak crosses the Midwest Region, pushing the polar front well to
the south of southwest Kansas. The Midwest/Great Lakes system will
push east quickly, and the polar front will stall out somewhere near
the Red River region late Thursday/Thursday Night. By early Friday,
very moist Gulf of Mexico air mass to the south of the old front
will begin to pull back northward toward western Kansas as westerly
winds in the mid levels across the Rockies induce lower level
leeside troughing. All of the global models show a nicely
established leeside trough with long north-south corridor of
south/southeast winds east of a sharpening dryline/leeside trough.
This will set the stage for a potential multiple day/night severe
weather setup across the western Great Plains, including southwest
Kansas, along with multiple mesoscale convective systems (MCS) in
the favorable broad west or west-northwest flow aloft. The flat
ridge centered across Arizona and New Mexico with several shortwave
troughs moving around the northern periphery of this ridge, along
with abundant low level moisture on south/southeast winds is the
classic pattern for multiple MCSs across the central High Plains.
This pattern is favored for a 3 or 4 day/night period beginning
Friday Night. Obviously, each day/night`s thunderstorm forecast will
depend on the magnitude and track of previous day/night`s MCS
activity, but the synoptic setup certainly favors increased
thunderstorm chances beginning Friday evening.
This pattern may be break around Tuesday of next week (11 June) when
ensemble means suggest increased amplification of the upper level
pattern (ridge in the west, trough in the east), which would push
the effective synoptic polar front to the south of southwest Kansas
with much drier/stable air mass in place.
&&
.AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/...
Issued at 1040 PM CDT Mon Jun 3 2024
VFR will continue for the next few hours, through 06-07z Tue,
before widespread MVFR/IFR stratus spreads over the airports on
light moist SEly upslope flow during the 07-12z Tue timeframe.
MVFR ceilings should prevail, and areas of fog will limit
visibility to 1 sm or less toward 12z Tue, with the highest
confidence at GCK/DDC. Given recent rainfall and standing water
in the GCK/DDC vicinity, the boundary layer may more easily
reach saturation, and fog may become locally dense, with
visibility down to 1/4sm. This trend will watched closely
through 12z Tue. Stratus and fog will dissolve quickly, no later
than 15z Tue, with VFR/SKC Tuesday afternoon. A cold front is
expected to provide a N/NEly wind shift to the airports around
15z Tue, followed by N/NE wind gusts of 25-30 kts, with the
strongest winds at GCK/LBL.
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SHORT TERM...Umscheid
LONG TERM...Umscheid
AVIATION...Turner
Area Forecast Discussion
National Weather Service Austin/San Antonio TX
902 PM CDT Mon Jun 3 2024
...New UPDATE...
.UPDATE...
Issued at 855 PM CDT Mon Jun 3 2024
Some isolated convection did manage to develop over portions of the
Rio Grande plains and the current forecast has this covered well. We
did opt to remove the precipitation chances for portions of the Hill
Country and I-35 corridor based on radar trends and recent runs of
the HRRR model. Otherwise, only minor changes were made to the hourly
temperature and dew points to account for observational trends.
&&
.SHORT TERM...
(Tonight through Tuesday night)
Issued at 217 PM CDT Mon Jun 3 2024
Scattered to broken cloud cover continues to hold on for most places
and has kept temperatures a bit lower, but with some breaks, we
should see highs warming later this afternoon. Will continue the
Heat Advisory out west for this afternoon. Most of the area should
remain dry today and tonight but there are two possible areas to
watch for possible activity in our CWA. The first is in the
southwestern CWA late this afternoon or evening. Already seeing one
storm well west of the Rio Grande and some of this activity could
push east of the Rio Grande later today. In addition, latest runs of
the HRRR had shown some lower chances of some possible activity in
the Fort Worth CWA clipping out northeastern counties this evening.
Will include a 20 PoP for both of these regions for now for the
overall low chance of rain with the higher probabilities of no rain.
Instability is high and therefore, can`t rule out a strong storm
with anything that does affect the CWA late this afternoon and
evening. Large hail and perhaps damaging winds would be the main
risk associated with any stronger storm.
The remainder of the area overnight will be rain free with warm
temperatures continuing. Should see another round of low clouds for
most of the area with lows in the middle 70s to near 80 degrees.
Mostly dry weather is expected tomorrow with temperatures on the
increase. The low-level thermal profile warms by 2-3C tomorrow which
should lead to a 3-4 degree increase in highs tomorrow compared to
today. Will likely need a Heat Advisory for most of the CWA tomorrow
outside of the Hill Country and Edwards Plateau for the expected
elevated heat index values. Another round of nocturnal stratus and
lows in the middle 70s to near 80 degrees can be expected tomorrow
night into early Wednesday morning.
Heat Precautions: Never leave people and/or pets alone within a
closed car, stay hydrated with plenty of water, wear loose-fitting
and light colored clothing, and take frequent breaks within the
shade and air conditioning.
&&
.LONG TERM...
(Wednesday through Monday)
Issued at 217 PM CDT Mon Jun 3 2024
The hot weather conditions continue on Wednesday through the
extended forecast period. Another Heat Advisory is likely for most
of South-Central Texas on Wednesday as heat index values are
forecast to range from 108 to 112 over parts of the Hill Country,
I-35 corridor and coastal Plains and up to 117 along the Rio Grande.
By Thursday, the subtropical high builds across the desert southwest
and continues through the latter part of the work week into the
weekend. The subtropical ridge is forecast to slowly moves to the
east through next week. In the mean time, several upper short waves
are forecast to move across the southern plains through the period,
and provide enough lift and instability for storms to develop to the
north and east of the local area while we remain dry.
As far as temperatures go, they are going to be slightly above the
normal climate values (95-100) across the Hill Country, I-35 and
coastal plains and well-above climate normals for areas along the
Rio Grande where afternoon highs could range from the 100 to 106
degrees.
&&
.AVIATION...
(00Z TAFS)
Issued at 641 PM CDT Mon Jun 3 2024
Convection well west of the Rio Grande will continue to be monitored,
but radar trends suggest this activity will stay locked up over the
higher terrain of Mexico. For now, we will not mention any convection
in the TAFs through the evening into Tuesday morning. We will see
plenty of high clouds from the above mentioned convection this
evening, along with low cloud development after 06Z along I-35. Low
clouds will lead to MVFR conditions through mid to late morning, then
lift and scatter to VFR. Confidence in low cloud development and
restrictions to VFR is lower at DRT, so we will keep the forecast
VFR.
&&
.PRELIMINARY POINT TEMPS/POPS...
Austin Camp Mabry 77 97 77 96 / 10 10 10 10
Austin Bergstrom Intl Airport 76 97 78 96 / 10 10 10 10
New Braunfels Muni Airport 77 99 77 99 / 10 10 10 10
Burnet Muni Airport 74 95 75 94 / 10 10 10 10
Del Rio Intl Airport 81 106 81 109 / 10 0 0 10
Georgetown Muni Airport 75 96 76 95 / 10 10 10 10
Hondo Muni Airport 78 102 78 101 / 10 10 10 10
San Marcos Muni Airport 76 98 77 97 / 10 10 10 10
La Grange - Fayette Regional 78 95 78 94 / 10 0 10 10
San Antonio Intl Airport 78 100 78 99 / 10 10 10 10
Stinson Muni Airport 79 101 79 101 / 10 10 10 10
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
Short-Term...Platt
Long-Term...05
Aviation...Platt
Area Forecast Discussion
National Weather Service Grand Junction CO
533 PM MDT Mon Jun 3 2024
.KEY MESSAGES...
- A surface front will bring some showers and a few embedded
storms to northern portions of the forecast area. The CO/WY
border will see this precip first before shifting to the
northern mountains and Flat Tops later this evening.
- Some high clouds will persist tomorrow with a clearing trend
Tuesday afternoon onwards.
- Temperatures will remain above normal into the coming week.
The warmest temperatures of the season thus far will be
Thursday and Friday at 10 to 15 degrees above normal.
&&
.SHORT TERM /THROUGH TUESDAY/...
Issued at 256 PM MDT Mon Jun 3 2024
Plenty of high clouds continue to stream into the area ahead of the
next system. Currently, the surface front is located in southern
Idaho down into northern Nevada and will keep moving eastward
through the afternoon. Some showers and a few embedded thunderstorms
will accompany frontal passage later this evening.
The cloud cover and weak cap may limit the convection and the latest
NAMNEST and HRRR guidance is also showing some slight decrease in
activity. That being said, isolated to scattered showers and storms
remain in the forecast with the most coverage from 6PM through
midnight. Favored areas will be along the CO/WY border in the early
evening hours shifting to the northern mountains and Flat Tops as
the evening progresses. After that, some residual showers will
continue mainly for the northern and central mountains but these
will decrease through the early morning hours.
By Tuesday morning, a stray rain shower may persist over the higher
terrain but better chances are for all precip having ended.
Northwest through northwesterly flow sets up over the area on
Tuesday bringing drier air to the region though neutral advection
will keep high temps very similar to what we saw today...maybe a few
degrees cooler. Some high clouds will be moving overhead during the
day becoming mostly clear heading into the early evening hours.
&&
.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
Issued at 256 PM MDT Mon Jun 3 2024
High pressure building overhead will continue the heat streak across
the Western Slope. By Wednesday temperatures are progged to rise ten
degrees above normal for early June and continue to climb through
Friday. Looks like Moab, Grand Junction and areas down to Delta will
likely reach their first 100 degree day this year. NBM probabilities
suggest over a 90 percent chance of a 100 degree day in Moab on
Friday, with GJ not trailing far behind (80% chance of max T`s
exceeding 99 degrees). Stay hydrated, my friends, summer is here,
just a little early this year.
Forecast highs are expected to peak on Friday, while the ridge`s
axis sets up directly overhead. A low pressure system spinning off
the Baja Peninsula will eventually nudge the high eastward. However,
there are discrepancies amongst deterministic guidance with regard
to how soon and where the low becomes embedded with stirring flow to
our north. More specifically, the trajectory of the low this weekend
will influence how much moisture is pulled from the southern Pacific
and Gulf of Mexico into the Western Slope. Precipitation
probabilities definitely favor the front range this weekend, though
the spine of the Rockies may bode well under this regime, as well.
Afternoon showers and thunderstorms would favor higher terrain on
Saturday, with adjacent valleys showing less than a 20 percent of
measurable precipitation. Fortunately, if the aformentioned low
crosses the area as an open wave on Sunday, that will boost the
chance for showers across high valley floors by the afternoon/
evening. Desert floors may not feel a spit of rain Saturday or
Sunday, although, passing clouds would bring some relief to this
early June heat wave.
Concerns for a blocking pattern developing upstream may maintain
this stagnant, and warmer than usual, weather pattern for early
June. Climate Prediction Center`s latest 6 to 10 and 8 to 14 day
outlooks both show temperatures likely above normal through the long
term period...and beyond.|
&&
.AVIATION /00Z TAFS THROUGH 00Z TUESDAY/...
Issued at 530 PM MDT Mon Jun 3 2024
Cloud cover and pockets of stable atmospheric conditions haven`t
favored thunderstorm activity thus far along the front`s
boundary. Even rain reaching the ground has been difficult to
detect upstream. Thus, have removed VCTS and replaced with VCSH
for evening TAFs. Gusty winds along and ahead of the boundary is
the main concern for most terminals. However, KHDN, KASE and
KEGE still have the greater potential for seeing measurable
precipitation and/or conditions dipping below ILS breakpoints
later this evening. Still anticipate clearing conditions in the
wake of today`s front, with widespread VFR conditions expected
tomorrow.
&&
.HYDROLOGY...
Issued at 530 PM MDT Mon Jun 3 2024
High pressure building overhead through the end of the week will
result in an unseasonably warm period across the Western Slope.
Simultaneously, as those temperatures rise, so will the rate of
snowmelt across our high terrain. Even though low to mid elevations
have already melted out, there`s still an abnormally high amount of
snow left over basins generally at and above 11,000 ft. As a result,
we`ll see creeks, streams and major tributaries along the Upper
Colorado River Basin rise. Seasonal peak flows are expected over the
next 10 days, with the Upper Gunnison, Upper Yampa and Colorado
Headwaters basins potentially peaking this weekend. Current
guidance oscillates diurnal peaks cresting the Action Stage for
portions of Gore Creek and Eagle River in Eagle County and the
Elk River in Routt County Colorado. We will continue to monitor
these evolving forecasts to see if any Flood products are
warranted. But for now, we just want to pass on the message:
As scorching temperatures lure folks to the water, please
remember the potential hazards associated with high flows during
the snowmelt season. Fast flows are not just dangerous for
those choosing to float the rivers. In addition, high diurnal
swings may drastically change the depth and flow for normally
small creeks and streams. Swift currents and cold water
temperatures can catch you off guard, so please be vigilant with
current conditions and look for forecast updates when
recreating or working near the water`s edge.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...None.
UT...None.
&&
$$
SHORT TERM...TGR
LONG TERM...ERW
AVIATION...TGJT
HYDROLOGY...ERW
Area Forecast Discussion
National Weather Service Goodland KS
514 PM MDT Mon Jun 3 2024
.KEY MESSAGES...
- Conditional potential for isolated severe thunderstorms in
vicinity of the Interstate 70 corridor in northwest Kansas
Tuesday morning (~4-10 am MDT / ~5-11 am CDT). The storms will
also produce heavy rain which may lead to localized flooding.
- A less active weather pattern is anticipated through the
remainder of the work week (late Tuesday through Friday),
with above normal high temperatures in the 80s and 90s.
&&
.SHORT TERM /THROUGH WEDNESDAY NIGHT/...
Issued at 128 PM MDT Mon Jun 3 2024
Low pressure across central Kansas is holding thick cirrus strong
across eastern portions of the CWA. The RAP seems to have the best
handle on the cirrus with 50-70% RH at 300 mb so opted to go with
that for sky cover. Drier air aloft looks to move in from the west
ahead of an incoming shortwave which should help dissipate the
stratus by 22Z. Also did increase high temperatures a few
degrees for the day as am expecting more mixing with sporadic
wind gusts around 20 mph to help warm us up even more; so
brought western portions of the area into the low 90s where dew
points are lower and cloud free.
Tonight, winds will become southerly and we will see strong moisture
advection return to the area. Winds will be sustained around 20-25
mph through the early morning hours as this is going on. A surface
trough, then nudges into the area from the north bringing a
period of nearly calm winds along its leading edge followed by a
switch to NW winds. Have went ahead and added in patchy fog
along and south of a Hill City to Tribune line where the
moisture advection looks to be the strongest and with the
lightest winds. RAP was suggesting near 100% RH within in this
area as well in the 850-700mb levels.
As for precipitation there is a 20-30% chance starting this
evening as a shortwave moves off of the Front Range bringing
some showers and storms to the NW portion of the area. Severe
weather is not expected with this activity. Throughout the
remainder of the night, as the above mentioned trough nudges
into the area this will be the source for additional scattered
showers and storms to develop. Currently it appears that the
most favored area for this development would be east of Kansas
Highway 27. These showers and storms look to be efficient rain
producers with PWATS int he 1.1-1.3 range and slower Corfidi
vectors would support slow moving cells, which may lead to some
localized flooding concerns especially for those that saw the
most rain last night. There is also a low (less than 5%) chance
for severe hail to occur with these cells as well with MLCAPE
around 1500 j/kg and MUCAPE around 3000 j/kg; the main question
will be how organized will they be as 0-6 shear is around 15-20
knots. The favored time for severe weather looks to be between
10-16Z (4am- 10am MT).
Tuesday and Wednesday will see a return to drier conditions as
ridging develops. Moisture will still be in place (although not
to the extent of late) so those with sensitivity to heat may
need to be aware. The warmest day currently looks to be
Wednesday with highs in the low to mid 90s. Winds tomorrow will
be out of the NW and breezy around 20 knots behind the trough
before becoming more westerly Wednesday as downsloping aids in
our warmup. Wednesday winds look to also feature deep mixing
with sporadic gusts of 25-30 knots as sustained winds will be
in the 10-15 knot range.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
Issued at 105 PM MDT Mon Jun 3 2024
Thursday...similar to 24 hours ago, daytime hours look to be
precipitation free with a 20% chance for showers and thunderstorms
to develop during the night south of Interstate 70 as 850-500mb
moisture increases from the southeast while a weather disturbance
move east off the Palmer Divide and Cheyenne Ridge and into our
area. High temperatures in the 80s with low temperatures in the 50s.
Friday...similar to Thursday and more generally speaking the past
week, we`ll be waiting for a weather system to move off the Colorado
front range and across our area, mainly in the very late afternoon
through midnight/overnight hours. Presently, we have 40% chances for
showers/thunderstorms during the night. High temperatures remain
above normal with middle 80s to lower 90s forecast. Low temperatures
fall into the middle 50s to lower 60s.
Saturday-Sunday...we`ll continue to have 20% to 50% chances for
showers and thunderstorms, mainly during the afternoon and overnight
hours and mainly west of Highway 25 due to continued weather systems
moving through from the west. High temperatures cool a bit into the
80s with low temperatures in the middle 50s to lower 60s.
Monday...500mb flow is a bit more from the northwest. There is
pretty good agreement between the GFS/ECMWF that a weather
disturbance moves through during the afternoon and overnight
hours, supporting 20%-50% chances for showers and thunderstorms.
High temperatures are forecast to be near normal in the 80 to
85 degree range with low temperatures in the 55 to 60 degree
range.
&&
.AVIATION /00Z TAFS THROUGH 00Z TUESDAY/...
Issued at 512 PM MDT Mon Jun 3 2024
VFR expected to prevail at both KGLD and KMCK through the TAF
period. Isolated showers and thunderstorms will be possible
through Tuesday morning, but the probability of directly
impacting either terminal is low.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...None.
CO...None.
NE...None.
&&
$$
SHORT TERM...Trigg
LONG TERM...99
AVIATION...024
Area Forecast Discussion
National Weather Service Gray ME
1033 PM EDT Mon Jun 3 2024
.SYNOPSIS...
Weak high pressure builds in from the north through Tuesday for
mostly fair weather outside of a few afternoon showers both
days. Temperatures will run above normal through mid week with
afternoon sea breezes bringing cooler conditions to the coast. A
trough approaches from the west Wednesday and will linger near
New England through the weekend with unsettled conditions.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
0235Z Update...
Showers have dissipated with the loss of heating this evening.
Leftover cloudiness conintue across portions of western Maine
and New Hampshire. Minor modifications made to the near term
forecast this evening for temperatures and dew points.
Otherwise, forecast remains on track with patchy fog forming
after midnight.
Update...
Isolated showers in the mountains and foothills will continue to
diminish as we move through sunset this evening. The latest HRRR
has the precipitation ending by around 00Z as well. Have removed
the chance for thunder this evening as the cool and stable
maritime airmass continue to push into the interior.
Otherwise, only minor tweaks to the near term temperature, dew
point and wind forecasts.
Prev Disc...
More instability and a better moisture profile has lead to a
pretty robust cumulus field from the foothills northward across
western ME and also into northern NH, but dry air aloft has
limited precip to only a few light showers thus far. Over the
next 2-3 hours, expect coverage of showers to increase somewhat
(with perhaps a storm or two) over these areas as more
boundaries come together, but with the dry air aloft aloft I
kept limited PoPs to 20-30%. Northerly steering flow aloft could
bring some of this activity farther south, but at the same time
it`s cooler and much more stable to the south where the
seabreeze has gone through.
Convection diminishes by sunset with dry conditions expected
overnight. Skies will range from partly to mostly cloudy with
patchy fog developing in some areas.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY/...
High pressure will be overhead to start Tuesday morning but will
gradually sink south through the day. The weak pressure gradient
will again allow for quick development of the seabreeze, keeping the
coast a bit cooler while the interior again warms into the mid 70s-
lower 80s, perhaps reaching the mid 80s across western and northern
NH.
A pocket of dry air aloft will keep most dry, but more instability
and the depth of the low-level moisture will be more favorable
across western and northern NH for isolated-scattered afternoon
showers. Following the diurnal cycle, showers will diminish by
sunset or so.
Going into Tuesday night, the upper ridge axis will be centered west
of the area, and models are showing weak PVA entering northern New
England on the eastern periphery of the ridge. With this source of
lift and a small amount of elevated instability, additional
showers could develop during the course of the night with this
looking to be mainly across northern NH. Outside of any precip
that develops, sky will be generally partly cloudy with patchy
fog possible with lows in the 50s.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
Overview: Rain chances improve during the long term. Expansive
low pressure will slowly slide east from the Great Lakes,
bringing periods of showers. The lows residence time will keep
unsettled conditions in the region at least through the weekend.
Details: Surface high pressure will be pulling SE off the New
England coast Wednesday, with slight boundary draped across many
northern New England states. Return flow from the low will
enhance onshore component of wind, leading to packing of
temperature gradient fairly far inland. Amid the increase in
convergence and instability, will see shower chances jump in the
afternoon for much of the interior and mountains.
The environment does bear some analysis here. Long, skinny CAPE
is presented in soundings, with PWAT values progged to surpass
the 75th percentile in the region and improving. So, precip
efficiency in any showers or storms would be decent...but mid
level RH is fleeting with a warm cloud depth that just gets
around 8 to 10 kft. Storm motion also looks marginal initially
with slow cloud layer winds but speedier up and downshear winds.
The concern here is a marginal environment becoming more potent
if developed storms interact with a boundary that forms from
seabreeze or terrain. We saw this a couple times last year that
lead to localized flash flooding. Considering the dry antecedent
conditions, this isnt a large concern at this time. But, storm
modes in models are starting to resolve single cells that
produce over an inch of rain in isolated areas. This seems to be
focused across the foothills and mountains of ME and NH, while
also including parts of interior ME.
Wednesday night, surface instability falls off with some
elevated instability remaining. This could prolong some showers
into the evening, but coverage should be on the downtrend.
Surface dewpoint depression closes across much of the interior
overnight. This could result in fog developing for much of the
interior. New developing low over the eastern Great Lakes will
hoist a warm front into southern New England Thursday morning.
This will lead to more synoptic forced rain moving into the
region slowly Thursday. While this surface low is expected to
pass off the coast, upper low and occluded front to the west
will prolong shower chances into the afternoon and evening
hours. This system will continue the unsettled pattern for a
greater portion of the extended forecast through the weekend.
A chance of rain runs into early next week in the forecast, and
unfortunately due to the upper low, it will be difficult to
provide much more resolution in timing and coverage at range.
One hedge would be the chance for showers to increase during the
day and afternoon as daytime heating enhances avail instability.
The upper low will slowly move northeast through early next
week.
&&
.AVIATION /03Z TUESDAY THROUGH SATURDAY/...
Short Term...VFR the rest of the day with a few showers, mainly
away from the coast and closest to HIE and AUG. Should these
pass over any terminal, brief VFR restrictions are possible, but
these will dissipate by 00Z. For tonight, light onshore flow
will lead to the possibility of patchy fog/low stratus and MVFR
to IFR restrictions. Conditions return to VFR through Tuesday
morning, which will again prevail through the day with coverage
of showers again much too low for VCSH in the TAFs. Patchy fog
will be possible again Tuesday night.
Long Term...SHRA for interior terminals Wednesday, but
restrictions should be minimal. Patchy fog may develop
overnight, with trend to IFR ceilings is expected through
Thursday. Thurs will also feature invading SHRA/RA through the
afternoon. With unsettled weather expected through late week and
the weekend, restrictions will be likely at times amid fog,
showers, and lowered ceilings.
&&
.MARINE...
Short Term...Winds and seas continue to remain below SCA levels
through Tuesday night. Light east to southeast flow becomes
northeasterly tonight and then returns to more southerly Tuesday
afternoon with the seabreeze and high pressure sinking south of the
Gulf of Maine. High pressure becomes centered just to the southeast
of Cape Cod Tuesday night and will result in a southwest wind at or
below 10 kt. Patchy fog is possible tonight through Tuesday
night.
Long Term...Below SCA conditions expected, although with a humid
airmass arriving, fog development over the waters is expected
from mid week through the weekend. This could reduce visibility
at times for portions of the coastal waters. Broad, upper low
pressure will slowly track towards the region during this time,
lifting north early next week.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...None.
NH...None.
MARINE...None.
&&
$$
NEAR/SHORT TERM...Cannon
LONG TERM...Cornwell
Area Forecast Discussion...Updated
National Weather Service Lincoln IL
814 PM CDT Mon Jun 3 2024
.KEY MESSAGES...
- There is a 20% chance for a thunderstorm west of I-55 this
evening. If a storm develops, it could produce locally gusty
winds and hail.
- There is a 40-50% chance for thunderstorms tomorrow afternoon.
The strongest storms could produce locally damaging wind gusts
and hail.
&&
.UPDATE...
Issued at 812 PM CDT Mon Jun 3 2024
A weakly sheared environment is present across much of MO/IL this
evening. Earlier this afternoon, thunderstorms that developed
over E MO produced an outflow boundary that has steadily
progressed northward, kicking off additional scattered showers and
storms. The lack of shear is resulting in updrafts being short-
lived, and while some showers/storms will percolate near that
aforementioned outflow boundary (along a corridor from the SE tip
of Iowa towards Flora/Olney) for another hour or two, the
expectation is that these will remain sub-severe and wane as
diurnal heating is lost. CAMs continue to suggest another round of
showers/storms develops late tonight along the leading edge of a
low-level jet, reaching southern portions of the ILX CWA after
sunrise, but then weakening thereafter. No significant changes
were made to the gridded forecast at this time, just PoP edits in
the first few hours to better reflect the short-term precip
evolution.
Erwin
&&
.DISCUSSION...
Issued at 107 PM CDT Mon Jun 3 2024
At 18z/1pm, SPC`s mesoanalysis suggested 1500-2500 J/kg SBCAPE
across central Illinois, but effective bulk shear under 20 kt and
lack of a forcing mechanism suggests we might just escape without
storms today. The 12z NAMNest and FV3 suggest something might
clip our west where one/more convective outflow boundaries could
stall, so we`ll have one eye on the radar, but at this point
convection is expected to stay to our northwest and southwest
until tomorrow. In the meantime, we`ll enjoy an afternoon of
summer-like warmth as temps continue to climb into the upper 80s
and dewpoints hover about 20 degrees lower.
The deterministic models bring some sort of meso-low/MCV out of
the Central Plains and into the region tomorrow morning/early
afternoon, with CAMs varying considerably in their depiction of
convection firing near it. The HRRR and ARW have storms developing
across our west and central CWA, while the FV3 has storms mainly
east of I-57 and the NAMNest has them split across our area - some
storms near/south of I-72 and others west of the IL River. Given
there will be more shear tomorrow in the vicinity of this MCV,
storms would have the potential to be a bit more sustained, though
instability is less certain and will ultimately depend on whether
any breaks in cloud cover can materialize ahead of it. Sometimes
these MCVs can produce "sneaky" severe weather events, so we`ll
have one eye on things. The output from the CAMs certainly
suggests a threat for localized damaging wind gusts and hail with
storms - wherever they track - tomorrow afternoon, but widespread
and/or significant severe weather is not anticipated. In terms of
temps tomorrow, highs should be generally a few degrees cooler
than today given (1) convection, (2) cloud cover, and (3)
increasing low level moisture with WAA ahead of the cold front
slated to arrive tomorrow night. High temps will vary considerably
by location (NBM`s 10th-90th range is mid 70s to mid 80s) for
these reasons, though we`ve got low 80s in the forecast area-wide
due to lack of confidence in the exact placement of
convection/clouds.
Then attention turns to another round of possible showers and storms
along the cold front tomorrow night. However, depending on how
overturned the atmosphere is from afternoon storms with the
aforementioned MCV, there may not be much instability leftover to
fuel convection along the front - especially with it moving into the
area so late. We will have a LLJ maintaining warm/moisture transport
conducive to at least marginal elevated instability, but with even
the 90th percentile sfc-500mb wind shear from LREF at only ~30-35 kt
along the front it`s not like we`re going to have so much shear that
it makes up for the lack of instability and results in widespread
storms. In fact, the 12z CAMs are suggesting the upstream line of
storms will break apart and much of the area could miss out on rain
altogether tomorrow night. Near/east of I-57, however, renewed
development is a possibility (see the 12z NAMNest) Wednesday should
the front slow down at all. We`ll keep an eye on that, but for now
have lowered PoPs slightly tomorrow night into Wednesday; we may
need to further lower those in forthcoming forecast updates if the
trend toward more sparse convection along the front continues.
Once the cold front clears the area, surface high pressure will
build in to hopefully keep us dry for a while. However, with temps
aloft cooling considerably (GFS has 850mb temps dropping to sub 2
degC across northern Illinois late Thursday), we can`t completely
rule out a surface based instability driven shower or storm
Wednesday through Friday; coverage would be sparse at any rate, so
we`ve kept PoPs around 10% (i.e., sub-mentionable) through that time
period.
This weekend into early next work week, ridging will attempt to
build into the region in the wake of the upper trough departing
slowly to the northeast, resulting in cool and stable northwest
flow. Models generally keep the ridge-riding MCSs to our southwest,
but we`ve maintained slight (20%) chances for precip early next week
for the possibility one of them sets up far enough northeast to clip
our area.
Bumgardner
&&
.AVIATION... (For the 00z TAFs through 00z Tuesday Evening)
Issued at 602 PM CDT Mon Jun 3 2024
Storms are possible near KSPI during the first few hours of the
period, but storms are looking less likely to reach KPIA, so
removed the VCTS mention there. Southerly or south-southeasterly
winds will continue through the period. Gusts subside after 01-02z
tonight, then pick back up by late morning (15-16z). VFR
conditions should be predominant, with scattered diurnal cumulus
around 4-6kft during the daytime hours. Scattered to widespread
thunderstorm development is expected across the region between
18-00z on Tuesday, but there was enough spread in the placement
and timing of the storms among various models to warrant PROB30
rather than VCTS.
Erwin
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
Area Forecast Discussion
National Weather Service Lake Charles LA
1002 PM CDT Mon Jun 3 2024
...New UPDATE...
.UPDATE...
Wx map shows high pressure off the Southeast U.S. coast ridging
across the Northern Gulf of Mexico, keeping southeast winds across
the region. Radar showing large MCS over Northeast Texas and North
Louisiana, now traveling more east-southeast. Large outflow boundary
just now entering Northern Rapides/Avoyelles parishes. This boundary
likely to generate some showers and a few thunderstorms for Central
Louisiana, but mostly watching the secondary bow echo now entering
Northwest Louisiana possibly affecting this region in a couple of
hours. Last few HRRR runs still going with the bulk of this activity
travailing more easterly as well, and weakening significantly. Grid
updates earlier this evening, with a few modifications to timing,
increased chances of showers and thunderstorms in the 30-50% range
across Central Louisiana for the next 2-3 hours, and diminishing
rapidly after Midnight. Slightly cooler temperatures into the lower
70s behind the outflow boundary, upper 70s to lower 80s ahead of
it. Overnight low temperatures remaining in the lower to mid 70s
north of I-10, mid to upper 70s further south.
08/DML
&&
.SHORT TERM...
(Tonight through Wednesday night)
Issued at 330 PM CDT Mon Jun 3 2024
Mid-afternoon sfc analysis shows high pressure centered off the
Carolina coast ridging wwd over the sern CONUS, maintaining a
moist srly low-level flow over the region. Water vapor imagery
shows weak ridging extending from nern Mexico and up through the
Sabine Valley trying to hold on while multiple disturbances riding
over try to break it down...the first of which has helped fire up
an MCS dropping ssewd from ern OK/wrn AR at the moment. Closer to
home, local 88Ds indicate diurnal convection has been slow to get
going today as a decent cap noted in the 12z KLCH sounding has
evidently been holding firm despite good warming.
Recent guidance is in agreement that the approaching MCS will
continue to do so into this evening...however the agreement
generally ends there as all sorts of solutions exist as far as
what shape the system will be in and where it will have the most
impact once in our area. Thereafter, there are hints in the
guidance that a 2nd complex could develop later tonight and move
into the forecast area prior to sunrise...blended guidance is
really having issues with latching on to this one, which is
evident in the first period POP/wx grids this afternoon. Perhaps
this is the feature that is being picked up dropping through the
area Tuesday morning into early afternoon, with minimal convection
expected the remainder of the day courtesy of a worked over
airmass. Stay tuned. Regardless of timing, SPC has included much
of the forecast area in at least a marginal risk for severe
weather through tomorrow with damaging wind gusts being the
primary threat. Likewise, WPC has included the same areas in a
marginal risk for excessive rainfall through tomorrow given the
very wet grounds from multiple rounds of sometimes heavy precip
the last several days.
The mid-level ridge building over the area which has been
advertised since late last week and which was supposed to suppress
convection through much of this week has pretty much disappeared
from the medium range global models as of this afternoon...
replaced by a continued nwrly flow aloft containing periodic
passing disturbances. The first of which is now progged to cross
the area Wednesday and combining with reasonable moisture (mean RH
values again to near 60 percent and PWATs to around 1.7 inches),
yet another round of showers/storms are expected, peaking during
the afternoon hours with max heating.
25
&&
.LONG TERM...
(Thursday through next Sunday)
Issued at 330 PM CDT Mon Jun 3 2024
The long term forecast is marked by uncertainty as models continue
to struggle over the synoptic pattern. On Thursday, a large stacked
low pressure system will be situated over the Great Lakes, while mid-
level ridging builds across the Rockies/Four Corners region. At the
surface, a cold front associated with the low pressure system will
be diving towards the Ark-La-Tex, while weak high pressure will be
to our east providing a light onshore flow across the CWA. Models
are at least in good agreement with moving the low pressure system
towards New England from late Thurs into early Sat however, it still
remains uncertain how this will impact the local area. Current
guidance wants to push the associated cold front all the way to the
coast by Sat morning, while previous runs hang the front up to our
north and/or wash it out completely. Regardless if the front does
make it through the CWA or not, its passage will be hardly
noticeable, with little more than a weak wind shift expected.
In addition, models continue to struggle with the evolution of the
western CONUS ridge towards the end of the week. Guidance is in
agreement with building the ridge eastward however, how far east it
actually builds will largely affect our weather pattern for the
later part of the forecast period. If ridging stays more to our west
and keeps us in a NWrly flow aloft we will continue to see daily
rain chances and potentially more rounds of severe weather. On the
other hand, if the ridge is able to build more directly overhead we
will trend towards a drier pattern.
With the lack of good agreement among guidance I opted to stick
closely with NBM, which paints small POPs each day with a trend
towards a drier pattern over the weekend. Temperature wise, highs
will be just slightly above normal for Thurs and Fri (in the low to
mid 90) before trending back towards seasonal norms (low 90s) Sat
and beyond. Overnight lows will generally rang from the low to mid
70s each night, with a few spots inland potentially reaching the
upper 60s.
17
&&
.AVIATION...
(00Z TAFS)
Issued at 607 PM CDT Mon Jun 3 2024
A line of storms currently entering North LA may move into the
vicinity of KAEX late tonight to around midnight while weakening.
An additional round of storms may occur again Tuesday afternoon,
but move farther south. Outside of convection, MVFR ceilings may
occur late tonight into early Tue as well. Outside of convection
winds will be generally south.
&&
.MARINE...
Issued at 330 PM CDT Mon Jun 3 2024
Caution headlines have been introduced on the wrn/cntl coastal
waters as srly winds are progged to increase to criteria this
evening thanks to a tightening gradient courtesy of low pressure
moving into the srn Plains.
25
&&
.PRELIMINARY POINT TEMPS/POPS...
AEX 72 89 73 91 / 50 30 0 40
LCH 77 88 77 89 / 20 20 0 20
LFT 76 88 77 91 / 30 20 0 20
BPT 78 88 77 91 / 20 20 0 10
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...None.
TX...None.
GM...None.
&&
$$
SHORT TERM...08
LONG TERM....17
AVIATION...05
Area Forecast Discussion
National Weather Service New Orleans LA
626 PM CDT Mon Jun 3 2024
...New UPDATE, AVIATION...
.UPDATE...
Issued at 613 PM CDT Mon Jun 3 2024
Like the previous night watching the MCS to our northwest closely.
Once again it appears that the remnants of the MCS should get into
the northwestern portions of the CWA and unlike previous nights
the CAMs actually are trying to hold onto it and just get it in
here before it completely dissipates. Like last night the belief
is that the MCS should maintain itself through northwest LA and
then after it gets on the other side of the theta e ridge and the
instability max there should be slow but steady weakening
approaching southwest MS just before midnight. This is about the
same thing as last night maybe an hour earlier. Not expecting
anything strong severe from this but likely a wetting rain for the
same locations that got it between 5z and 9z last night. /CAB/
&&
.SHORT TERM...
(This evening through Tuesday night)
Issued at 335 PM CDT Mon Jun 3 2024
Upper pattern is a bit west-northwesterly across the area with a
shortwave to the northwest across Kansas, and a stronger trough
across the Pacific Northwest. Isolated precipitation tried to
develop around 18z, but with low level flow from the south and
upper flow from the northwest, it appears that shear has stopped
most or all of the updrafts from becoming deep up to this point.
Temperatures at 3 PM CDT were generally in the upper 80s with dew
points in the lower and middle 70s.
Main concerns over the next 36 hours will be the potential for
mesoscale convective systems to the northwest of the area to
travel southeastward and reach the area. One such area is
currently over Kansas. Most guidance dissipates this complex
during the evening, but the runs of the HRRR since 12z bring it
pretty close to the CWA before dissipating it around midnight.
While we currently aren`t carrying precipitation mention across
southwest Mississippi late this evening, threat is not zero.
A somewhat more significant threat appears to be possibly shaping
up for the afternoon hours tomorrow, as a second complex is
forecast to develop over Oklahoma after midnight tonight and
follow much of the same track southeastward. While most guidance
doesn`t indicate this system reaching the area tomorrow, the
recent runs of the HRRR have it reaching the area around midday
tomorrow, and this does have the support of the ECMWF operational
model. Forecast soundings from the GFS do show potential for the
cap to be broken with CAPE values exceeding 3000 J/kg, low level
lapse rates of 7.5 to 8C/km and DCAPE values exceeding 1300 across
northern portions of the area. SPC on their midday Day 2 update
spread the Marginal Risk into our area, and can`t really discount
it. So, we will continue carrying thunderstorm chances for
tomorrow across the area, although the GFS/NAM solutions argue
dry. The HRRR solution has it through the CWA by about 02z
Wednesday, but tends to be a bit slow, especially if it becomes
cold pool dominant, so a dry forecast for Tuesday night isn`t
totally unreasonable.
Don`t see much need to diverge much from NBM temperature numbers,
although might nudge overnight lows up a bit based on
verification.
&&
.LONG TERM...
(Wednesday through Sunday night)
Issued at 335 PM CDT Mon Jun 3 2024
As has been the case for the last week or more, ridging to the
west of the local area and troughing to the east, global models
have struggled to agree. Timing of shortwaves and/or convective
complexes lead to a low confidence in details. The operational
ECMWF is the wetter solution for Wednesday and Thursday, then
dries out for the weekend. The operational GFS is comparatively
dry for Wednesday and Thursday, then becomes the wetter model for
the weekend. The current NBM deterministic numbers trend toward
the ECMWF solution, but it is not a high confidence forecast at
this time.
Until a definitive trend regarding precipitation chances becomes
apparent, can`t see making large changes in the NBM deterministic
temperature forecast.
&&
.AVIATION...
(00Z TAFS)
Issued at 613 PM CDT Mon Jun 3 2024
Right now all terminals are in VFR status and likely to remain
that way through the rest of the evening. After 5z convection
likely begins to move in from the northwest with MCB and BTR again
the most likely terminals to see minor impacts. Convection is
expected to be weakening and only anticipating cigs and vsbys to
drop into MVFR status from the convection.
Elsewhere low clouds will be a possibility again early in the
morning. Most sites should only drop into MVFR status with cigs
between 1500-2500 ft but one or two terminals could see cigs drop
below 1k ft for a period or two. /CAB/
&&
.MARINE...
Issued at 335 PM CDT Mon Jun 3 2024
Main marine concern over the next few days is likely to be the
potential for thunderstorms, with one such period possible
tomorrow afternoon. Confidence in timing is fairly low. There
could be brief periods where Small Craft Exercise Caution
headlines are necessary. One would be around sunrise tomorrow over
the western waters. That one is rather borderline, so we`ll let
the evening shift take a look at that one before a final decision.
&&
.PRELIMINARY POINT TEMPS/POPS...
MCB 70 89 71 90 / 40 40 0 40
BTR 76 93 76 94 / 30 30 0 30
ASD 75 91 75 93 / 10 40 0 30
MSY 77 90 77 92 / 10 30 0 30
GPT 77 88 77 89 / 20 40 10 30
PQL 74 90 75 91 / 20 30 0 20
&&
.LIX WATCHES/WARNINGS/ADVISORIES...
LA...None.
GM...None.
MS...None.
GM...None.
&&
$$
SHORT TERM...RW
LONG TERM....RW
AVIATION...CAB
MARINE...RW
Area Forecast Discussion...Updated Aviation
National Weather Service Saint Louis MO
1042 PM CDT Mon Jun 3 2024
.UPDATE...
Issued at 1041 PM CDT Mon Jun 3 2024
Updated forecast for tonight, since early evening activity has
diminished, I have removed POPs for a majority of the forecast
area through 08z Tuesday. Then as the trough and/or any remnant
MCVs approach the region from the southwest, increased POPs from
southwest to northeast through 12z Tuesday.
Byrd
&&
.KEY MESSAGES...
- Several rounds of showers and thunderstorms are expected through early
Wednesday. Isolated severe storms are possible through this
evening and again on Tuesday, capable of producing large hail
and damaging winds. Locally heavy rainfall is also possible.
- Dry weather is expected mid-late week followed by a chance (20-
40%) of showers and thunderstorms this weekend.
- Temperatures are expected to be at or just below normal through
early next week.
&&
.SHORT TERM... (Through Late Tuesday Night)
Issued at 346 PM CDT Mon Jun 3 2024
Scattered showers and thunderstorms have developed across central
and southeast Missouri along outflow boundaries that moved into the
area. The atmosphere is very unstable over the CWA right now with
MLCAPES between 1000-2000 J/kg with no CIN which the RAP shows
holding on through sunset. The latest water vapor imagery is
showing a trough over the eastern Plains that will move slowly east
into Missouri tonight. This trough is far enough west that there is
little ascent or low layer or deep layer shear for organized
thunderstorms tonight. As such, should only see isolated
instances of strong-severe hail and wind through mid evening.
There may also be some locally heavy rainfall with any training
thunderstorms given the high PWATS and warm cloud depths.
I have lowered PoPs late this evening into the overnight hours as
CAMS have backed off on the coverage of showers and thunderstorms
overnight. Still expect an uptick in scattered showers and
thunderstorms again on Tuesday as the HREF is bringing the
aforementioned trough across the area. It is possible that a MCV
from overnight Plains activity will move across the area sparking
additional convection. The CAPE/shear parameter space tomorrow
afternoon into tomorrow evening will once again support isolated
severe storms with locally heavy rainfall. The coverage of showers
and thunderstorms will become more widespread later in the evening
and overnight as the NAM/GFS is showing a upper trough dropping
southeast into Missouri and Illinois with an attendant cold front.
Britt
&&
.LONG TERM... (Wednesday through Next Monday)
Issued at 346 PM CDT Mon Jun 3 2024
There is general agreement between the deterministic models and the
LREF that the upper flow will stay northwesterly late week through
the upcoming weekend. Wednesday through Friday still looks dry as a
large surface high will move southeast across the Midwest with very
few of the ensemble members producing precipitation over the area
during this timeframe. There is more uncertainty as we go into
the weekend as each of the models are showing slight differences
in the timing and strength of two shortwaves on Saturday and
Sunday which will determine the placement and amount of the QPF.
There is an increase in LREF ensemble members producing rain
(20-40%) with these two shortwaves over the weekend. There are
lower chances as we go into next Monday with the model consensus
showing a surface high moving back into the area.
Temperatures will not stray too far from early-mid June normals as
850mb temperatures will stay in the 10-15C range. The NBM IQR is
around 5 degrees, though it does increase by early next week behind
a cold front.
Britt
&&
.AVIATION... (For the 06z TAFs through 06z Tuesday Night)
Issued at 1041 PM CDT Mon Jun 3 2024
Dry, VFR flight conditions expected through the morning at TAF
sites. Then added vicinity thunderstorm mention at KUIN, KCOU and
KJEF between 17z and 20z Tuesday and between 18z and 22z Tuesday
in the St. Louis metro area for any afternoon activity that pops
up as trough/remnant MCV moves through. Could see brief period of
MVFR ceilings during this period, but confidence is low so did not
add mention.
Then as cold front approaches the forecast area, have another
round of showers and storms, after 03z-04z Wednesday for KUIN,
KCOU and KJEF. For St. Louis metro area, showers and storms will
not move in until after 06z Wednesday.
Otherwise, winds will persist from the south through the forecast
period.
Byrd
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...None.
IL...None.
&&
$$
WFO LSX
Area Forecast Discussion
National Weather Service Little Rock AR
702 PM CDT Mon Jun 3 2024
...New AVIATION...
.SHORT TERM...
(This evening through Wednesday)
Issued at 211 PM CDT Mon Jun 3 2024
Tricky forecast on tap in the short term with multiple storm systems
set to move through the state over the next 24 hours. Currently the
remnants of an early morning system is pushing east of Little Rock
and continues to weaken. These storms have created quite a bit of
stability to the atmosphere across the northern half of the state.
A second line of storms is pushing into western Arkansas as I type,
however with the more stable air in place across northern and
central parts of the state from this mornings convection, the severe
weather threat across that area is fairly low. However, the
southern half of the state remains prime for severe weather with
ample SB CAPE in place across those portions of the state.
Later this evening, Hi-Res CAMS are showing yet another round of
showers and thunderstorms to move into western Arkansas during the
overnight/early morning hours on Tuesday. While models disagree in
the strength of the system, they do agree that there will be an
additional round of rain to the region.
Beyond the near term, nearly zonal flow aloft will continue with
continued short wave troughs...the next being early Wednesday
morning as yet another storm system is forecast to move through the
state.
Despite this unsettled weather, temperatures will remain right
around normal for this time of year. High temperatures will be in
the mid to upper 80`s with lows ranging from the 60`s to lower 70`s.
&&
.LONG TERM...
(Wednesday Night through next Monday)
Issued at 211 PM CDT Mon Jun 3 2024
A break in precip chances will be in the forecast for the Thu-Fri
period. H500 NW flow will be in place with a sfc ridge extending
south into the state behind a front. Drier air and slightly cooler
temperatures will be noted by Friday with temperatures on Thursday
expected to be quite hot.
Rain chances return to the forecast by the weekend into early next
week as a new front sinks south toward the state and becomes the
focus for additional showers and thunderstorms at times.
&&
.AVIATION...
(00Z TAFS)
Issued at 700 PM CDT Mon Jun 3 2024
Line of storms will cont to impact eastern and southeast AR early
this evening, with MVFR/IFR conds at times mainly at KPBF and
KLLQ. Rain wl cont to taper off from the west this evening behind
the convection. Looking at VFR conds thereafter, with some low
clouds forming later tngt resulting in MVFR/low end VFR ceilings.
Low fcst confidence conts regarding convective trends heading
into Tue. Included PROB30 groups late tngt and Tue mrng, mainly
based on the HRRR trends attm.
&&
.LZK WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SHORT TERM...65
LONG TERM....67
AVIATION...44
Area Forecast Discussion
National Weather Service Marquette MI
1029 PM EDT Mon Jun 3 2024
.KEY MESSAGES...
- Showers and a few thunderstorms progress eastward across west
and central Upper MI today. Greatest coverage will be over the
west. Severe storms not expected.
- Frequent opportunities for showers and thunderstorms over the
next 7 days, with a break on Tuesday.
- Above normal temperatures through Wednesday, then turning
cooler for the second half of the week.
&&
.UPDATE...
Issued at 1027 PM EDT Mon Jun 3 2024
Rain showers have almost completely cleared out of south-central and
eastern Upper Michigan as of 10 PM with satellite imagery
showing clearing skies across most of the area. The exception to
that is across the central UP especially farther south, where
CAMs had been indicating fog development tonight. While fog
development is still possible in these areas, recent satellite
imagery show the stratus deck becoming more continuous. If this
trend continues, the radiational cooling necessary for fog
development may not occur and have begun to trim back on fog
coverage/intensity in the forecast. Also, even though showers
have largely left the area, SPC mesoanalysis still indicates
250-500 J/kg of MUCAPE across most of the western UP where the
LCL to LFC layer is around 80% RH. However, recent satellite and
radar trends indicate this is sufficiently dry to cap
additional shower development, especially considering the loss
of daytime heating. Have therefore decided to remove mentionable
rain chances from the remainder of tonight`s forecast.
&&
.SHORT TERM /THROUGH TODAY/...
Issued at 141 PM EDT Mon Jun 3 2024
RAP analysis shows a 500mb shortwave over Minnesota generally
flattening with time this morning and early afternoon. This
correlates with the decrease in rain shower intensity with a
broad line of showers over the central UP at 15Z per KMQT radar
reflectivity and METAR obs. CAMs consistently show this
deteriorating trend continuing as forcing continues to decrease
and precipitation battles dry air. However, a break in the
showers altogether will be brief at most as a shortwave over
Iowa will progress northeast throughout the day today and force
another round of showers through central to northern Wisconsin
by 20Z today. The main source of uncertainty is the northern
extent of the showers and thunderstorms, as cloudy conditions
associated with the current shortwave are limiting the ability
of the atmosphere over Upper Michigan to destabilize. The 12Z
HREF shows some SBCAPE recovery in the west, but with forcing
being limited to the south and central UP, where even HREF max
SBCAPE struggles to reach 250 J/kg, severe weather is not
expected, and thunder chances are limited to below 33%. As far
as high temperatures go, clearing behind the showers in the west
and the persisting dry air over the east will make the west and
the east ends warm into the low 70s today while the central UP
stays in the 60s.
Overnight, as heating decreases, so too will shower coverage, with
HREF probabilities of hourly QPF > 0.01" not exceeding 40% after 03Z
tonight. Persistent cloud cover and a more moist surface airmass
will limit radiational cooling, with lows around the mid 50s and low
60s tonight. In the wake of showers, marine dense fog over Lake
Superior is 60%+ likely per the HREF, with the central UP seeing
30-60% chances to see patchy dense fog overnight. With the wide
range of probabilities, no land-based dense fog advisories are
going to be issued with this forecast package until a bit more
certainty is gained in regards to the moistening of the
atmosphere by the showers.
&&
.LONG TERM /TUESDAY THROUGH MONDAY/...
Issued at 404 PM EDT Mon Jun 3 2024
Another subtle shortwave moving through the Great Lakes will keep a
potential for a few sprinkles, light rain showers, and a few rumbles
of thunder across the eastern UP into Tuesday morning. Otherwise,
with plenty of lower level moisture behind today`s rain showers and
partially clearing skies behind the front, much of the UP should
be starting off with some patchy fog. This mixes out soon after
sunrise with our high sun angles, then a brief dry period is
expected until late afternoon over the far west at the very
earliest as a second, stronger cold front approaches from the
Northern Plains. With warm air advection continuing ahead of the
cold front, expect the warmest temperatures of the week to
occur Tuesday, with highs getting into the 80s across some of
the interior areas, particularly over the west and downslope
areas near Lake Superior where the increasing southerly
downslope winds throughout the day could locally increase
temperatures by at least a few degrees; the warmest temperatures
will likely be around Ontonagon to the Porcupine Mountains. In
addition to the warm temperatures, Tuesday may also feel pretty
muggy, with much of the guidance showing dewpoints in the lower
to mid 60s across the UP.
The cold front looks to begin bringing showers and thunderstorms to
the western UP Tuesday evening, though guidance is hinting at some
earlier convection during hte late afternoon courtesy of a pre-
frontal trough rippling through. With quite an unstable airmass
(SBCAPE in excess of 1000j/kg) and an inverted-v type sounding, any
stronger cells that can get going could bring down some marginally-
severe winds or hail. That said, bulk shear remains lackluster even
as the cold front approaches, with values generally less than 30
knots likely not enough to sustain a severe threat much further
eastward into the UP. What may be more of a concern is the threat
for heavy rainfall, with ensembles generally showing PWATS around and
even in excess of 1.5in. Soundings show plenty of deep moisture and
impressive warm cloud depths, with storm motion largely parallel to
the cold front. Training could be a problem, particularly throughout
the western UP where we were able to pick up on widespread rainfall
amounts around and in excess of half an inch over the past day. For
its part, HREF ensemble mean rainfall totals show a widespread 0.5-
0.75in across the western half of the UP, but higher totals in
excess of an inch are possible with some members even as high as
1.5in.
The cold front continues through the eastern half of the U.P.
Wednesday as a secondary shortwave drops down from Canada and brings
light rain showers and maybe a thunderstorm or two back across the
western half of the U.P. Wednesday afternoon behind the front.
Behind the cold front, expect cooler temperatures to dominate the
rest of the extended forecast period as a synoptic troughing set-up
settles over Canada and rotates multiple shortwaves across our
region throughout the rest of this week and upcoming weekend. This
will bring multiple light rain shower chances across our area for
the rest of the extended period, and maybe a thunderstorm or two
during the afternoon hours when daytime heating becomes maximized.
With cooler and a somewhat drier airmass working in, it is not out
of the question that RH falls into the 30s at times throughout the
extended period...but will note that this isn`t very certain given
hit and miss rain chances, rather a cloudy period, and lackluster
mixing in soundings. Winds may be elevated at times throughout the
period, particularly Thursday and Friday with a tighter pressure
gradient over the area, which could enhance drying at the surface.
This would all point to a concern for fire weather into the extended
period, but mitigating this will be the early-week rainfall.
&&
.AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/...
Issued at 831 PM EDT Mon Jun 3 2024
Very tricky forecast with clearing skies aloft over a moist and
stagnant low level air mass that has potential to result in
dense fog and VLIFR cigs/vsby. At this time, the worst
cigs/vsby are expected at SAW where cigs have already lowered to
IFR and southerly upslope flow may allow for continued lowering
despite clearing aloft. However, overall confidence is
generally low. Skies recently cleared at IWD/CMX but there are
low clouds around and a bank of fog on Lake Superior that
appears to be expanding this evening. Radiation fog may also
develop at each terminal overnight tonight, but confidence is
highest at SAW. Am not expecting rainfall for most of this TAF
period though drizzle is possible if fog gets thick enough. A
TEMPO group was put in at CMX/SAW overnight to address these
low-probability, but high- impact scenarios. Regardless,
improvement is expected after sunrise with surface heating help
to dissipate fog, where it develops. There is also a chance for
a thunderstorm late in this period, mainly at IWD. Otherwise,
light southerly winds prevail at SAW/IWD with southeast or
easterly winds at CMX.
&&
.MARINE...
Issued at 404 PM EDT Mon Jun 3 2024
Winds generally out of the SE remain elevated across the eastern
half of the lake, gusting to around 20-25 knots for the most part.
However, especially around the Keweenaw where downsloping comes into
play, higher gusts around and even in excess of 30 knots remain
possible into the early evening hours. Winds fall back below 20
knots overnight while a high pressure ridge briefly builds into
the region. This tranquil period will be short-lived as winds
pick up again later in the day Tuesday ahead of our next
approaching frontal system. SSE winds gust to around 20 knots
across most of the lake Tuesday evening through Tuesday night,
with some higher gusts of 25- 30 knots north of the Keweenaw.
After winds briefly fall back behind the passing cold front
Wednesday morning, we could see southwest to westerly winds pick
up to around 20 knots over the west half of the lake Wednesday
afternoon as a secondary shortwave moves through. As additional
shortwaves rotate through our area the rest of this week through
this weekend, expect winds to increase from the west and
northwest at times; we could see westerly winds gust up to 20 to
30 knots Thursday and again to 20 to 25 knots from the
northwest Friday as shortwave lows impact the Upper Great Lakes.
As for other marine concerns this week, expect lingering patchy fog,
dense at times, across most of the lake tonight through Tuesday in
the wake of our rounds of rain today. This patchy fog looks to
persist until the second, stronger cold front moves through Tuesday
night and Wednesday, when the cooler air behind the front could
allow the moisture to mix out. Thunderstorms return late Tuesday
afternoon as the second cold front moves into the far western lake;
some severe weather could be seen over the far west Tuesday
afternoon and evening near Duluth, although the chance for severe
weather is still rather low (~5%); severe hail and winds are the
primary concerns. The thunderstorm activity continues across Lake
Superior from west to east Wednesday until leaving into northern
Ontario late in the day.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
Dense Fog Advisory until 9 AM EDT /8 AM CDT/ Tuesday for
LSZ162-240>243-263.
Dense Fog Advisory until 9 AM EDT Tuesday for LSZ266.
Lake Michigan...
None.
&&
$$
UPDATE...
SHORT TERM...GS
LONG TERM...LC
AVIATION...EK
MARINE...LC
Area Forecast Discussion
National Weather Service Omaha/Valley NE
553 PM CDT Mon Jun 3 2024
.KEY MESSAGES...
- A few spotty thunderstorms possible (10-15% chance)
this afternoon in far southeast Nebraska and far southwest
Iowa.
- Higher storm chances Tuesday afternoon (60-90%) with a
15-20% chance of severe storms, mainly in southeast Nebraska
and southwest Iowa. Large hail and damaging winds are the
primary threats.
- Saturated soils continue to keep flooding a concern as showers
and storms move through northeast Nebraska tomorrow afternoon.
- Mostly dry Wednesday into the weekend with highs in the mid
70s to mid 80s.
&&
.DISCUSSION...
Issued at 316 PM CDT Mon Jun 3 2024
Today and Tomorrow:
Water vapor imagery this afternoon features a vigorous shortwave
trough entering the Pacific Northwest, with a broad band of ascent
stretching ahead of it from CA to WY/MT. To the east, an MCV
over Kansas continues to power an MCS traveling the ArkLaTex
region while additional shortwaves continue to waft to the north
and east. Drilling down to the surface, a local surface low was
analyzed over far northwest Kansas with a surface
trough/convergent boundary stretching north/northwest into
eastern Montana. To the direct south of the forecast area, the
aforementioned MCS has turned over much of eastern Kansas, but
has left southeast Nebraska into southwest Iowa with leftover
instability on the order of 1500-2000 J/kg. A combination of
convergence in those areas and some northward component of the
advection of the MCV to the south will help create a few pop up
showers and storms in extreme southeastern Nebraska and
possible into southwest Iowa. While there is some decent
instability, shear will be on the low end with HRRR forecast
soundings depicting around 3 kts of shear, giving storms little
to work with and maintain healthy updrafts for any meaningful
amount of time (with any chances diminishing by 7 PM). Highs
will continue to peak in the mid-to-upper 80s with light winds
and provide a splendid evening for those getting off work.
The main concern of the forecast period comes into focus tomorrow,
as the aforementioned trough moves east towards the area
dragging a cold front. Increasing warm air advection will being
to develop after 7 AM, and could help spark a few morning storms
in eastern Nebraska ahead of the incoming front, where dry low
levels could result in a stray strong gust or two due to
evaporative cooling. During the afternoon, sufficient
instability is expected to develop and strong convergence along
the front is expected to result in an increasing-in-coverage
line of showers and storms. Timing of any showers and storms
continues to lean towards an initiation time of 3 or 4 PM to the
northwest of the Omaha and Lincoln Metros, with those storms
exiting to the east by 9 PM. Weak shear of less than 20 kts will
lower the ceiling of any severe threat with storms tomorrow
afternoon. The highest potential for severe storms is expected
to occur at peak heating and shortly after when instability is
maximized, with largely straight line hodographs pushing the
main hazard towards damaging hail and wind (though a tornado
can`t be ruled out in far southeast Nebraska and southwest
Iowa). One wildcard to watch would be a slow progression of the
MCV to the south, which could increase cloud cover and limit
instability if it moves east slower than models anticipate ahead
of the front. Additionally, it won`t take much rainfall to
create flooding issues for already saturated soils and
watersheds.
Wednesday and Beyond:
With the front moving off to the east for Wednesday, we`ll find
ourselves in a northwesterly mid/upper flow pattern with the main
jet streak settled nearly overhead to just north of the area. Rain
chances for the remainder of the work week remain low, but there
could be a pop up storm or two that develops as a shortwave
moves through the flow Wednesday or Friday evening. Highs during
this time will remain nice in the upper 70s to 80s with typical
afternoon winds of 20 to 25 mph keeping things from feeling
stagnant outside. Beyond the forecast period, our next best
chance for widespread showers and storms return Monday as a more
dynamic system swings south and across the area.
&&
.AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/...
Issued at 547 PM CDT Mon Jun 3 2024
Southerly winds are expected to persist at all TAF sites through
the overnight hours, with sustained speeds under 12 knots.
Between 09Z and 13Z, there is a low chance of a stray shower or
two moving through or near KOFK. Though non-zero, the
probabilities are too low to include in TAFs at this time. May
put in a TEMPO group for these if the signal persists at the 06Z
TAF issuance. Otherwise, after 18Z, scattered thunderstorms are
expected to develop across southeast Nebraska and southwest Iowa
(KOMA and KLNK). Will likely include a TEMPO group for these
storms in a subsequent TAF issuance as well.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...None.
IA...None.
&&
$$
DISCUSSION...Petersen
AVIATION...Darrah
Area Forecast Discussion
National Weather Service Topeka KS
625 PM CDT Mon Jun 3 2024
.KEY MESSAGES...
- Hit or miss thunderstorms remain possible this afternoon into
early evening. Severe chances look low, but there could be hail or
gusty winds with stronger storms.
- Severe thunderstorms are possible Tuesday late afternoon into
evening with large hail and damaging wind as the main hazards.
- Dry weather returns mid-week, then low chances of mainly
nighttime storms arrive into this weekend.
&&
.DISCUSSION...
Issued at 301 PM CDT Mon Jun 3 2024
Convectively induced vort max and MCV have been slowly moving across
the area throughout the day. A broader view of the upper air pattern
depicts the next trough over the Intermountain West, which will set
the stage for tomorrow`s weather. In the meantime, some breaks in
the cloud cover have allowed for some destabilization at the
surface, and CAPE between 1000-2000 J/kg will keep thunderstorm
chances around with the MCV into the early evening hours. The HRRR
has been the only one of the CAMs that has captured the ongoing
convection in central portions of the CWA, although even that has
been inconsistent with the evolution of any further convection
through the afternoon and evening. With time, lift should be best in
eastern portions of the area as the MCV continues to progress, but
instability also decreases slightly as you go east. Have kept low
chances (15-30%) of showers and thunderstorms mainly into this
evening, then decreasing in coverage overnight into early Tuesday.
For Tuesday, the aforementioned upper trough is progged to move
across the northern Plains while pushing a cold front across the
region. Most short-term guidance has this boundary starting to move
into north central KS counties in the late afternoon hours with
convergence helping to develop convection shortly thereafter (around
23Z). However, some guidance is later with a broken line of
thunderstorms, closer to 01Z. Northeastern KS counties remain closer
to the best upper support, where thunderstorms would have the best
chance of sustaining themselves. Increasing dew points into the
afternoon should allow for plenty of instability with 2000-3000
J/kg, and deep-layer shear around 35 kt should be sufficient for
organized updrafts assuming there is enough forcing to get them
going. Storms should exit the forecast area by around midnight.
Upper ridging develops over the southwestern CONUS mid-week,
favoring a dry pattern Wednesday and Thursday. Wednesday looks warm
with highs in the upper 80s to low 90s. Thursday sees a slight cool-
down into the 80s. Northwest upper flow develops over the area by
the end of the week with weak perturbations rounding the ridge,
bringing chances for storms mainly during the overnight periods
Friday night into Saturday and Saturday night into Sunday. Chances
remain low due to the low-predictability nature with these weakly
forced systems.
&&
.AVIATION /00Z TAFS THROUGH 00Z TUESDAY/...
Issued at 625 PM CDT Mon Jun 3 2024
There is some potential for mvfr to ifr cigs after 11Z at TOP
and FOE, otherwise VFR is expected at all locations. Winds
southerly generally 10kts or less through the period. Potential
for tsra increases after 21Z and will look at inclusion with
next issuance.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
DISCUSSION...Picha
AVIATION...53