Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 07/01/22
AREA FORECAST DISCUSSION
National Weather Service Albany NY
741 PM EDT Thu Jun 30 2022
.SYNOPSIS...
Mostly clear skies and dry conditions will continue into
tonight. Hot temperatures are expected on Friday, with some late
day showers and thunderstorms possible. A frontal boundary will
continue to bring showers and thunderstorms for Friday night into
Saturday, before drier and slightly cooler air arrives for Sunday
into Independence Day.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
Updated at 735 PM EDT. Current forecast is on track and just
made a few minor tweaks to the grids based on latest temperature
trends. Skies will remain mostly clear this evening with just
some high clouds and temperatures falling from the 70s into the
60s. It appears that the combination of high clouds and a light
breeze will be enough to keep much fog from forming, although a
few light patches will be possible around daybreak in the
valleys. Previous discussion is below.
As of 335 PM EDT...Weak upper level ridge axis is centered over
the area this afternoon with surface high pressure sliding
eastward across New England. With the surface high pressure
nearby, skies are fairly clear, with just some diurnal cumulus
around.
For this evening into tonight, skies will continue to remain
partly to mostly clear. The ridge axis will be slowly shifting
eastward through the overnight. While the diurnal cumulus will
dissipate this evening, patches of mid and high level clouds
may start to increase from the west, as the low to mid level
flow will start to increase out of the south to southwest.
While some warm advection will be underway aloft, limited
moisture in place won`t allow for any precip. Surface dewpoints
will slowly be increasing through the night as the low-level
flow shifts to the south, but the short duration of the
overnight and a light breeze will help prevent much radiational
fog from forming.
Overnight lows will be in the low to mid 60s for many areas,
although some upper 50s are possible across the Adirondacks and
southern Vermont.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/...
On Friday, 850 hpa temps will be around +16 to +20 thanks to the
southwest flow in place. Our area will be in a warm sector,
behind a departing warm front and ahead of a cold front over the
Great Lakes. With plenty of sun expected, temps will reach the
low 90s in valley areas, with 80s across the high terrain. Heat
Index values will be close to the actual temps, as dewpoints
won`t be overly muggy (mainly upper 50s to low 60s) so we should
fall short of heat advisory criteria through the day. Still,
anyone spending extended time outdoors should take precautions,
as it will be quite warm. While skies will be fairly sunny in
the morning, some patchy clouds are expected by afternoon,
thanks to some building cumulus.
CAMs (such as the 3km HRRR and NAMNest) show some convection
will start spreading towards our area by Friday evening (mainly
after 21z). This initial convection looks fairly isolated to
scattered and will be mainly impacting the northwestern part of
the area. A rogue strong storm can`t be ruled out with this
activity across the western Mohawk Valley or western Adirondacks
before sunset, as moderate amounts of instability (around
500-1000 J/kg of SBCAPE) and just enough mid-level flow (700 hpa
winds around 30 to 35 kts) to produce some locally strong wind
gusts.
Some additional round of showers and embedded thunderstorms are
expected into Friday night as the front continues to get closer
to the area. While the mid-level flow will be increasing, the
nocturnal stable layer near the surface will help limit
instability and keep the severe threat fairly low into Friday
night. Still, many areas may see some wet weather and rumbles of
thunder as activity passes west to east across the area. Temps
will remain mild and muggy into Friday night with temps in the
60s.
The front will be crossing the area on Saturday. While northern
areas will see the passage earlier in the day, it won`t be
crossing for areas south of the Capital Region until the
afternoon. This could allow for some instability to build up
ahead of the front and with 0-6 km bulk shear of 40 to 50 kts,
there could be some severe storms across southern areas for the
afternoon hours. Damaging winds are the main threat, although
some small hail can`t be ruled out within the strongest storms
as well. SPC has southern areas in a Slight Risk and this makes
sense considering the shear, strong forcing and potential
instability in place. Temps will range from the low to mid 70s
in the Adirondacks behind the front to the low to mid 80s ahead
of the boundary in southern and eastern areas.
The front should cross by evening, allowing for precip to wind
down and move southeast of the area. Cooler and less humid air
will move in for Saturday night with drying conditions. Lows
will generally be in the 50s.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
A general west to northwesterly zonal mid-level flow will be in
place Sunday and Monday with surface high pressure over the region.
This should result in drier weather to end the Fourth of July
weekend. Expect temperatures near seasonable levels with comfortable
humidity levels and a light west to northwesterly breeze each
afternoon.
The weather pattern then becomes a bit more uncertain and complex as
occasional upper-level troughs or shortwave pass through the
continued west to northwesterly flow Tuesday through Thursday. While
this should prevent any higher heat or humidity from advecting into
the region (temperatures remaining near seasonable levels and
humidity levels remaining in the comfortable range), but will bring
an increase in isolated to scattered shower or thunderstorm chances.
Global models have a large range of solutions during this period,
though it looks like we could get into a more unsettled weather
pattern at times. We generally ran with NBM pops for now which
highlights slight to low chance pops each day. Certainly, there will
be times of rain and times of dryness, but there is low confidence
on when to expect each.
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
Through 00z/Sat...A warm front will lift northward across the region
tonight and place the area within the warm sector of a system that
could bring some isolated showers and thunderstorms toward the end
of the TAF period.
Tonight will consist of mainly VFR conditions with just a few mid
and high clouds around. With the extra cloud cover, chances for fog
development are low and will not include in any TAF at this time.
The daytime hours Friday will start out with just some high cirrus
clouds, then diurnal cumulus will begin to develop around 18z with
bases around 8-10 kft. Isolated showers and thunderstorms may
develop later in the afternoon but due to the sparse coverage, will
leave out of the TAFs at this time.
Wind will be light and variable through the overnight, though should
pick up our of the south at KALB between 5-10 kt toward daybreak.
Wind then becomes southwesterly at 10-15 kt from late morning
through the afternoon with a few gusts around 20 kt possible,
especially at KALB/KPSF.
Outlook...
Friday Night: High Operational Impact. Likely SHRA...TSRA.
Saturday: High Operational Impact. Likely SHRA...TSRA.
Saturday Night: No Operational Impact. NO SIG WX.
Sunday: No Operational Impact. NO SIG WX.
Sunday Night: No Operational Impact. NO SIG WX.
Independence Day: No Operational Impact. NO SIG WX.
Monday Night: Low Operational Impact. Slight Chance of SHRA.
Tuesday: Low Operational Impact. Slight Chance of SHRA.
&&
.FIRE WEATHER...
Dry weather is expected tonight with light winds and RH
recovering to near 80 percent or higher. On Friday, a south to
southwest wind will be around 5 to 10 mph with afternoon RH
values as low as 30 to 40 percent. Some showers or t-storms are
possible late in the day and into Friday night. Some areas may
see some showers or thunderstorms lingering into Saturday as
well.
&&
.HYDROLOGY...
Dry weather is expected tonight into most of Friday. Some
showers and thunderstorms are expected Friday evening into
Friday night. As a frontal boundary settles south on Saturday,
some additional showers and thunderstorms are possible, before
dry weather returns for Sunday into Monday.
Rainfall amounts within showers and thunderstorms will be highly
variable. While basin average amounts look to be around a
quarter to a third of an inch, localized point totals up to an
inch are possible. While this rainfall may allow for brief
ponding in urban or low lying areas, the recent dry weather
makes this rainfall much needed and few hydrologic issues are
anticipated through the weekend.
For details on specific area rivers and lakes, including
observed and forecast river stages and lake elevations, please
visit the Advanced Hydrologic Prediction Service /AHPS/ graphs
on our website.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
MA...None.
VT...None.
&&
$$
SYNOPSIS...Frugis
NEAR TERM...MSE/Frugis
SHORT TERM...Frugis
LONG TERM...Rathbun
AVIATION...Rathbun
FIRE WEATHER...Frugis
HYDROLOGY...Frugis
Area Forecast Discussion
National Weather Service Cheyenne WY
535 PM MDT Thu Jun 30 2022
.SHORT TERM...(This evening through Saturday night)
Issued at 225 PM MDT Thu Jun 30 2022
Precip chances continue to be the primary forecast challenge in
the short term.
Currently...Surface frontal boundary lays along a line from
Sidney to just north of Cheyenne...westward to a low pressure
system analyzed just south of Riverton this afternoon at 18Z.
Surface winds still south here at Cheyenne and southwest out by
Laramie...so front has not come through as of yet at these two
locations. Had a line of showers come through the southern CWA
earlier this morning that has stabilized the atmosphere. But we
have seen pockets of sunshine with temperatures climbing to the
low 80s here at Cheyenne and mid 70s at Laramie. Seeing another
area of thunderstorms out by Rock Springs moving east along the
I-80 Corridor heading for Carbon County
Latest short term RAP guidance from SPC`s Mesoanalysis page
showing surface based CAPE increasing...currently at around 800 to
900 J/KG here at Cheyenne and near 1000 J/KG at Rawlins. We
continue to destabilize with continued surface heating. HRRR
simulated radar does show storms developing once again in the next
hour or so as CAPE increases.
HRRR/RAP guidance does increase PoPs across the area later this
afternoon and continuing it into the mid evening hours as front
stalls near the Laramie Range and an upper shortwave tracks across
the front. High PWAT values this afternoon up near .8 inches west
of the Laramie Range and near 1.2 inches in the Panhandle. Will
keep high PoPs going in the afternoon forecast today through
roughly 02-03Z before diminishing with surface heating ending.
Looks like a repeat for Friday with the upper shortwave moving
northeast into central South Dakota. SPC has a Slight Risk for
severe storms across the northern Panhandle and a Marginal Risk
for the rest of the Panhandle down into eastern Colorado. With the
surface front being pulled east with the upper shortwave...does
look like we stand a better chance for severe storms. 0-6km shear
values up near 45kts for the Panhandle Friday afternoon into the
east slopes of the Laramie Range. Could be a busy day Friday.
For Saturday...Looks like less coverage of PoPs as ridge axis
moves overhead. But still a chance for the mountains. We will
see. So far...the guidance has been pretty poor on PoPs as deep
monsoonal moisture has stayed south and east.
.LONG TERM...(Sunday through Thursday)
Issued at 225 PM MDT Thu Jun 30 2022
No major changes from previous forecasts were made with this
update. Convective potential for the Independence Day holiday
remains uncertain, but continued to nudge PoPs up slightly from
the NBM to maintain slight chance or chance for showers and
thunderstorms wording in the forecast for most of the area.
Similar nudging was done for Tuesday.
Previous Discussion:
Fairly active pattern setting up in the long term forecast, with a
chance for afternoon showers and thunderstorms just about every day.
Near zonal flow aloft will begin to give way to upper level ridging
over the western CONUS with an upper level low becoming near
stationary across the Pacific Northwest, amplifying the downstream
ridge. This feature is expected to become a decent blocking pattern,
ultimately locking the upper level low to the western seaboard and
preventing much movement within the flow. As mentioned previously,
main forecast challenges will remain with the chance for afternoon
convection just about every day in the extended forecast, which will
largely depend on surges of enhanced moisture advection into the
CWA. Current long range model guidance has precipitable water values
remaining on the higher side, ranging from 0.75 to 1.5 through the
weekend, as a plume of monsoonal moisture pushes northward. This
combined with several shortwave disturbances pulsing within the flow
should be enough for afternoon showers and thunderstorms to persist
this weekend, with Sunday remaining strong for a much better
monsoonal moisture push into our region and precipitable water
values remaining quite high. With focus being draw to this upcoming
holiday, will need to continually monitor the forecast trends, with
a high level of uncertainty due to model variability. Earlier GFS
model runs indicated a much more favorable environment on Monday for
gusty downburst winds and stronger thunderstorm potentials that the
recent runs have trended away from, keeping the majority of Gulf
moisture advection further to the east. Nevertheless, should be
enough residual moisture available to produce isolated showers and
thunderstorms in the afternoon. With that being said, it is still a
bit too far out to call and will need to be monitored throughout the
weekend. In terms of temperatures for the holiday, they are expected
to be on the warm side with southeastern Wyoming just slightly above
normal. Daytime highs are expected to be in the high-80s to low-90s
for areas east of I-25, mid to high-80s for areas to the west, and
60s across the higher terrains. For the Nebraska Panhandle, above
normal temperatures expected with daytime highs in the mid-90s.
&&
.AVIATION...(For the 00Z TAFS through Friday afternoon)
Issued at 535PM MDT Thu Jun 30 2022
Primary Aviation concern over the next 18 hours will mainly be this
evening as a band of moderate to heavy rain showers and
thunderstorms moves southeast across southeast Wyoming through 03z
this evening...and over southern Nebraska between 02z and 05z late
this evening as an upper level disturbance moves across the region.
This activity has a history of producing wind gusts of 40 to 55 mph
and 2-4 mile VIS across Carbon County.
HAZARDS/WEATHER TRENDS: KRWL should be finished with the
precipitation as of 00z to 01z, with KLAR and KCYS the next
terminals to see a sudden drop in CIGS and VIS as the line of
thunderstorms moves across Albany and Laramie counties. Expect
moderate to locally heavy rainfall at these two terminals between
00z and 03z. This activity will shift east into the KSNY area later
this evening. Added gusty winds and lower VIS to these terminals for
the 00z TAF package. Otherwise, will keep an eye on fog development
late tonight depending on rainfall amounts.
&&
.FIRE WEATHER...
Issued at 225 PM MDT Thu Jun 30 2022
Monsoonal moisture to remain in place today through the weekend
before shifting back to the southeast. Afternoon humidity expected
to stay above critical levels with this moisture. Good chances for
wetting rains this afternoon...especially along the I-80 Corridor.
Daily chances for wetting rains through Sunday...before we begin
to dry out again. Warmer temperatures and drier air could lead to
elevated to critical fire weather conditions next week.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...None.
NE...None.
&&
$$
SHORT TERM...GCC
LONG TERM...MN/MRD
AVIATION...TJT
FIRE WEATHER...GCC
Area Forecast Discussion
National Weather Service Goodland KS
505 PM MDT Thu Jun 30 2022
.SHORT TERM...(Through Friday night)
Issued at 203 PM MDT Thu Jun 30 2022
Today-Tonight: The Tri-State area remains situated on the
northern periphery of a broad upper level ridge -- at the far
southern fringe of the mid-latitude westerlies. Though the
synoptic pattern remains essentially the same (compared to
yesterday).. guidance continues to indicate a far greater
potential for convection during the late afternoon/evening..
perhaps assoc/w a subtle change in the orientation/magnitude of
the upper level ridge over the 4-Corners and stronger flow aloft
(at/above 300 mb) over the Intermountain West/northern Rockies
bringing small amplitude waves in closer proximity to the central
Rockies. 19Z (1 pm MDT) SPC mesoanalysis data (700-400 mb DPVA)
suggests that such a wave may be present invof the CO/WY/NE
border. Simulated reflectivity forecasts via the HRRR and NAM NEST
continue to suggest that convection will develop in the lee of
the Rockies during the mid-afternoon, increasing in coverage and
progressing downstream into western KS during the late aft/eve
(reaching the CO/KS border by ~00Z) -- and that separate/distinct
development may occur along a weak, SW-NE oriented thermal-
moisture boundary (TMB) -- invof a line extending from Oakley-
Norton-Hastings. Forecast soundings continue to indicate a dry
thermodynamic environment characterized by skinny, high-based CAPE
profiles and a kinematic environment characterized by weak low-
mid tropospheric flow (10-15 knot winds from the surface to ~500
mb). In such conditions.. organized convection is not anticipated.
19Z SPC mesoanalysis data indicates an exceedingly poor
thermodynamic environment in place over the region --
characterized by lingering convective inhibition and marginal
instability (~100-250 J/kg MLCAPE).. with perhaps ~500 J/kg east
of Hwy 283 (Norton-Hill City) near the moist side of the TMB --
and that little in the way of additional destabilization is
likely. In weak forcing regimes, convection allowing guidance
tends to be far less reliable. Confidence is low with regard to
whether or not convection emanating from the Rockies will
meaningfully intensify and/or persist downstream into western KS.
Seasonably/climatologically strong DCAPE and inverted-V
thermodynamic profiles will, of course, support brief/isold
instances of damaging wind in association with any deep updrafts.
Fri-Fri night: Similar to today (no significant change in the
synoptic pattern) -- except that forecast confidence is even
lower -- as lingering convection and/or convective remnants (late
tonight and Fri morning) may alter environmental conditions over
the region.
.LONG TERM...(Saturday through Thursday)
Issued at 310 PM MDT Thu Jun 30 2022
Models have an upper level ridge building back across the region on
Saturday and Sunday. The upper level high/ridge shifts southeast
across TX and the Gulf coast region on Monday. An upper level
trough moves across the central plains into Midwest late next
Wednesday into Thursday. Expect mainly upper level zonal flow
early in the period becoming southwest upper level flow and then
northwest upper level flow by the end of the period.
At the surface on Saturday a surface low is projected to be
across southwest SD/nw NE region with another across southern
Kansas with a weak boundary between them. By sunday a stationary
boundary is projected to be across southeast WY southeast to
southern KS. On Monday a surface low pressure is across western
Nebraska with a warm front across Nebraska southeast into southern
IN. A surface trough is across western Nebraska into eastern
Colorado. On Tuesday the surface low is across central Nebraska
with a stationary boundary across Nebraska southeast to OH valley
and a surface trough across southern Nebraska southwest to NM. By
Wednesday and Thursday the stationary boundary is projected to be
across southern Nebraska/northern KS southeast into northern KY.
Temperatures will start off lower in the upper 80s to lower 90s
for afternoon highs on Saturday. Sunday`s afternoon high
temperatures will be in the 90s. For Monday and Tuesday expect
afternoon high temperatures to climb back into the lower 90s and
lower 100s. Then slightly cooler by next Wednesday and Thursday in
the upper 80s to middle 90s. Overnight low temperatures will be
mainly in the lower 60s to middle 70s.
Expect some better precipitation chances during the extended
period early and then more isolated activity Monday into Tuesday
and then better chances late next Wednesday into early next
Thursday as upper level trough passes through.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 500 PM MDT Thu Jun 30 2022
KGLD...VFR conditions are expected through the period. Gusty north
winds at taf issuance may continue for another few hours before
setting below 12kts this evening. On Friday, winds veer to the
northeast then east at speeds up to 11kts. Regarding precipitation
chances, very difficult to lend any confidence to any of the
numerous model solutions. It appears that there is a chance in the
05z-08z timeframe so have included it into the forecast. Further
updates may be needed once storms get going and confidence
increases in impacting the terminal.
KMCK...VFR conditions are expected through the period. Northeast
winds around 11kts are expected from taf issuance through 15z.
After 16z, winds steadily veer to the east with speeds approaching
12kts at the end of the taf period. Regarding precipitation
chances, very difficult to lend any confidence to any of the
numerical model solutions and pinpoint a time that the terminal
may be impacted. So for now, have kept any mention of
precipitation out of the forecast and should confidence increase
amendments will be made.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...VINCENT
LONG TERM...EH
AVIATION...99
Area Forecast Discussion
National Weather Service Huntsville AL
1012 PM CDT Thu Jun 30 2022
...New AVIATION...
.NEAR TERM...
(Tonight)
Issued at 756 PM CDT Thu Jun 30 2022
Sporadic convection persists this evening, but has struggled to
remain deep for any prolonged period. At the present time, cells
were primarily along or north of the TN River where low level
lapse rates were steepest. The BMX sounding indicates a very
moist atmosphere with ~1.9 inches of PW, but low level lapse rates
drop off. The latest HRRR runs indicate a continued diminishing
trend after sunset, and our current forecast reflects that,
especially after 03-04Z. Will not adjust much at this point and
continue to monitor convective trends this evening.
&&
.SHORT TERM...
(Friday through Saturday night)
Issued at 241 PM CDT Thu Jun 30 2022
Short term model consensus suggests little change in the synoptic
pattern through the first half of the weekend, as a relative
weakness in the mid-level height field will remain positioned
from south TX northeastward into the TN Valley. Although we expect
convection to be largely initiated by mesoscale outflow
boundaries and closely tied to the diurnal warming cycle, weaker
subsidence aloft compared to points to our east and west should
allow for a greater coverage of storms on both Friday and Saturday
afternoon, and we have indicated POPs in the 40-50% range each
period. A thermodynamic environment similar to today`s may yield
brief gusty winds and frequent lightning with the strongest storms
both days. Given weak steering flow and precipitable water values
in the 1.75-2 inch range, locally heavy downpours could also
result in ponding of water and minor flooding in a few locations.
Highs will remain in the u80s-l90s, with lows in the u60s-l70s,
and patchy mist/fog will be a nightly occurrence, especially in
the vicinity of heavier rainfall swaths.
&&
.LONG TERM...
(Sunday through Thursday)
Issued at 241 PM CDT Thu Jun 30 2022
Global models suggest that the Atlantic subtropical ridge will
begin to slowly retrograde into the Gulf of Mexico this weekend,
and should both expand across the Gulf coast states and strengthen
early next week in response to the motion of a northern stream
trough across the Pacific Northwest. Although strengthening
subsidence aloft in this regime will lead to a gradual decreasing
trend in the coverage of afternoon/evening shower and thunderstorm
activity early next week, we will maintain a fairly low POP in
the updated grids to reflect an increasingly moist and unstable
airmass featuring dewpoints in the l-m 70s and precipitable water
in the 2-2.25 inch range. There are some indications that the
center of the subtropical ridge may migrate further westward into
the southern Plains by the end of the extended period, which would
result in moderately strong north- northwest flow aloft across
the TN Valley by Wednesday/Thursday. This could potentially allow
for a greater coverage of convection by the middle of next week as
clusters of thunderstorms may spread southeastward into the
region ahead of a slow-moving cold front, but due to uncertainty
in this scenario, we have kept POPs in the low chance range. Highs
will steadily warm into the l-m 90s, which may also lead to Heat
Advisory criteria being reached across portions of the region on
Tuesday/Wednesday/Thursday. Lows will respond to the increase in
dewpoints, with temperatures expected to only fall into the l-m
70s at night.
&&
.AVIATION...
(06Z TAFS)
Issued at 1010 PM CDT Thu Jun 30 2022
VFR conditions are expected through the period, with the exception
of in any SHRA or TSRA Friday. These should start to develop by
~16Z, with isolated to scattered coverage expected. Brief gusty
winds will be possible in and near TSRA.
&&
.HUN WATCHES/WARNINGS/ADVISORIES...
AL...None.
TN...None.
&&
$$
NEAR TERM...17
SHORT TERM....70
LONG TERM....70
AVIATION...17
Area Forecast Discussion
National Weather Service Lincoln IL
832 PM CDT Thu Jun 30 2022
.SYNOPSIS...
Issued at 617 PM CDT Thu Jun 30 2022
Mild and dry conditions are expected across central Illinois
tonight with lows dropping into the upper 60s to around 70
degrees. A cold front will sink southward into the region on
Friday, triggering scattered thunderstorms mainly during the
afternoon and evening. Highs will range from the lower 80s far
north around Galesburg...to the lower 90s along and south of the
I-72 corridor.
&&
.UPDATE...
Issued at 832 PM CDT Thu Jun 30 2022
Mostly clear skies prevail across central Illinois this evening
with 01z/8pm temperatures in the upper 70s and lower 80s. With
light southerly winds of 5-10mph expected to continue through the
night, lows will be a few degrees warmer than they were last night
in the upper 60s to around 70 degrees. Current forecast is right
on track and requires no update at this time.
&&
.SHORT TERM...(This evening through Friday)
ISSUED AT 238 PM CDT Thu Jun 30 2022
This afternoon, high pressure is centered just off the mid
Atlantic Coast with ridging extending back into the Deep South.
Low pressure is analyzed over northern Ontario with a front
stretching across portions of the Upper Midwest to the High
Plains. In between these features, moisture from the Gulf of
Mexico is beginning to spread north from the lower to the mid
Mississippi Valley and expect dew points in the 70s to return to
areas south of I-70 this evening and dew points near 70F for most
of central Illinois SE of the Illinois River by midday tomorrow.
The cold front to our northwest is expected to reach roughly the
Illinois River by midday Friday and dew points pooling in the
lower 70s ahead of the front will contribute to seasonably
modest instability peaking around 1500 J/kg during the afternoon.
The front will slip south of the I-72 corridor through the
afternoon. Some diminishing showers are possible early in the day
as the front initially moves into the forecast area, then expect a
lull in precip around midday before thunderstorms redevelop mid
afternoon into the evening as a low amplitude shortwave moves
across portions of central and northern Illinois. Overall forcing
remains weak along the tail end of the frontal boundary but
soundings show the column weakly capped or uncapped so expect at
least some widely scattered storms to be able to develop. Despite
the modest instability, deep layer shear is 30-40 kt which could
support rotating updrafts. In addition, steep low level lapse
rates (0-3km around 8 C/km), high DCAPE values (in excess of 1500
J/kg), and LCL heights in excess of 1 km all point to the
possibility of a wind/microburst threat at least during the late
afternoon and early evening hours. Storm coverage should stay on
the lower end with only an isolated severe threat expected at this
time.
Friday night, the frontal boundary is expected to settle across
portions of southern Illinois and precip should diminish across
central Illinois. Focus Friday night will be well to the west as a
low level jet develops across portions of Kansas and Nebraska then
shifts east overnight. Some of the decaying remnants of this
complex of storms associated with this low level jet could move
into portions of central Illinois during the day Saturday, but
otherwise expect the chance for stronger storms to redevelop along
the stalled frontal boundary over southern Illinois. Much of the
day should be dry Saturday barring the front slowing down
significantly. Temperatures will moderate closer to the seasonal
norms across central Illinois with afternoon highs in the mid 80s.
.LONG TERM...(Friday night through Thursday)
ISSUED AT 238 PM CDT Thu Jun 30 2022
Early Sunday, high pressure will be centered over the Great Lakes
and the frontal boundary should still be in place across southern
Illinois. Much of the day should be dry as a result but there is
at least a chance for showers and storms as the front begins to
lift north in response to a shortwave moving across portions of
the central Great Plains. Temperatures remain seasonable on the
cool side of the boundary.
Models begin to see more divergence the first half of next week
but the general idea is that low pressure will be in place over
the central Great Plains with the frontal boundary draped over
portions of the Upper Midwest and Midwest with daily chances for
showers and thunderstorms including nocturnal MCSs driven by the
low level jet. Central Illinois should remain on the warm side of
the boundary most of the period with temperatures warming into the
90s each day which coupled with dew points in the lower to mid
70s will result in peak heat indices around or in excess of 100
degrees each day.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 624 PM CDT Thu Jun 30 2022
Main aviation forecast challenge will be the potential for
scattered convection on Friday. Cold front will drop southward
into the area during the afternoon resulting in a few thunderstorms.
Exact areal coverage and timing is still somewhat uncertain:
however, model consensus suggests the need for VCTS in the TAFs.
Based on latest HRRR guidance, have included VCTS at KPIA between
17z and 20z...then further south to the I-72 terminals after 21z.
Winds will initially be southerly at less than 10kt tonight, then
will veer to W/SW and increase to 10-15kt ahead of the approaching
front Friday morning. Once the front passes, winds will become
northwesterly across the board by mid to late afternoon.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Barnes
SYNOPSIS...Barnes
SHORT TERM...Deubelbeiss
LONG TERM...Deubelbeiss
AVIATION...Barnes
Area Forecast Discussion...UPDATED
National Weather Service North Platte NE
747 PM CDT Thu Jun 30 2022
.UPDATE...
Issued at 747 PM CDT Thu Jun 30 2022
The shower and thunderstorm activity across WY this evening should
sweep through wrn Nebraska overnight. A forecast update is in
place using the HRRR, RAP and short term model blend. This delays
the arrival of the showers and thunderstorms across WY by a few
hours.
&&
.SHORT TERM...(This evening through Friday night)
Issued at 240 PM CDT Thu Jun 30 2022
The primary concern for the short term will revolve around the
potential for strong to severe thunderstorms both this evening and
tomorrow.
Currently, a cold front has progressed through the area this morning,
and is now positioned southwest-northeast from far northwest Kansas
into central Nebraska. Aloft, an upper shortwave, evident in GOES
upper level WV imagery, is progressing across portions of Utah and
western Wyoming.
The aforementioned shortwave will continue to push eastward this
evening, with increasing ascent aloft as it approaches. This should
promote widely scattered thunderstorm development across the higher
terrain of eastern Wyoming/Colorado through late afternoon.
Thunderstorms are then expected to push eastward through the
Panhandle this evening, impacting areas primarily along and south of
Highway 2. Forecast soundings indicate marginal deep layer shear, on
the order of 25 to 35kts. CAPE profiles remain long and skinny,
within a plume of increasing subtropical moisture aloft. H7-H5 lapse
rates remain somewhat meager (7-7.5C/km) as well, pointing to a
limited risk for large hail in any sustained updrafts. However,
nearly dry adiabatic low level lapse rates and inverted-v profiles
indicated in soundings suggest the potential for strong/damaging
outflow winds. Convection wanes locally after midnight and much of
the overnight is anticipated to remain dry.
The cold front will lift northward through tomorrow morning,
reaching near the SD/NE border by late afternoon. Yet another
shortwave will dive across the Rockies through the evening, helping
to promote additional convective initiation. Deep layer shear
remains somewhat marginal again tomorrow, though increasing mid-
level flow in advance of the shortwave should promote updraft
organization. High-res guidance remains in good agreement with
respect to initiation location (across the high terrain in far
eastern Wyoming into northwest Nebraska) though confidence wanes
with respect to storm mode and evolution. An increasing southerly
LLJ into the warm frontal boundary would suggest convection should
persist through much of the late evening into the early overnight
hours. The more aggressive high-res members show cold pool
development and a progressive MCS through much of the Sandhills and
into central Nebraska overnight. Trends with respect to storm mode
will need to be monitored, as any upscale growth would lead to
increasing damaging wind potential. Convection exits the area to the
south and east prior to sunrise Saturday.
.LONG TERM...(Saturday through Thursday)
Issued at 240 PM CDT Thu Jun 30 2022
Although temperatures are expected to fall back into the 80s on
Saturday, model guidance indicates that temperatures will return to
above the climatological norm through the extended period. These hot
temperatures will persist as the upper level ridge amplifies in
western portions of the US early next week. Daytime temperatures in
the 90s are expected across the region with temperatures peaking
into the upper 90s and low 100s on Tuesday. Temperatures only ease
back into the upper 80s and low 90s to round out the week, however
ensemble guidance is implying yet another heat spell by the weekend.
As the upper level ridge amplifies across the Plains through the
week, ensemble guidance suggests that 500mb heights may approach or
exceed the 97th percentile by the weekend. Southerly flow will allow
WAA to advect into the region which is suggested by the ensemble
guidance. Ensembles suggest that the 700mb and 850mb temperatures
approach or exceed the 90th percentile leading to well above normal
temperatures across the region. This is in agreement with what the
Climate Prediction Center (CPC) shows with the 8-14 Day Temperature
Outlook being `likely above normal` for the region.
Besides the heat, limited precipitation is expected in the extended
forecast. Low pressure is expected to linger over the PNW coast
allowing for numerous shortwaves to impact our area. These
shortwaves bring in sporadic chances of low-end PoPs to the forecast
throughout the week. If precipitation does occur, widespread QPF
amounts are unlikely and will remain localized.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 648 PM CDT Thu Jun 30 2022
VFR conditions expected through the forecast period. Aviation
concerns focus on early evening shower and weak convection
development. Activity for the most part has only skirted the edges
of LBF airspace and expected motion will keep it out of the
terminal. Additional activity will approach from the west later
tonight and early Friday morning and have included -TSRA mention
to account for this. Gusty, erratic winds cannot be ruled out with
this activity but overall trend will be for thunderstorms to
weaken with eastward extent so will need to monitor closely.
Attention then turns to Friday afternoon thunderstorm chances but
current thoughts are for this threat to fall just beyond the end
of the forecast period with the greatest impacts expected at VTN.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
UPDATE...CDC
SHORT TERM...Brown
LONG TERM...Viken/Brown
AVIATION...NMJ
Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
907 PM CDT Thu Jun 30 2022
.UPDATE...
Issued at 907 PM CDT Thu Jun 30 2022
No significant changes to the going forecast this evening, though
did slow the arrival of chance pops across the far southeast part
of the cwa into early Friday morning. Also lowered wind gusts a
bit for the remainder of the overnight hours.
Mild and somewhat breezy warm sector remains in place across the
forecast this area this evening. Gusts have diminished since late
afternoon, though we will likely continue to see a few sporadic
gusts near 20 mph at times overnight as 30-35 kt low level jet
spreads over our shallow decoupled boundary layer. Otherwise, main
weather feature is a cold front to our northwest which stretches
from unseasonably deep low pressure near Hudson Bay, through the
upper Mississippi Valley and into the Central Plains. This front
will slowly push southeast overnight, moving into northern IL
during the pre-dawn hours. Scattered shower and thunderstorm
chances will increase along/ahead of the front during this time in
confluent flow ahead of the approaching front, and the west-
southwesterly low level jet provides some moistening in the
750-800 mb layer. High-res CAM guidance continues to show some
spread in solutions with respects to coverage into early Friday,
though the greatest chances look to remain across the northwest
half of the cwa (roughly northwest of a UIN-PNT-VPZ line) through
mid-morning. Chances likely increase late morning into Friday
afternoon however, especially along and south of the front where
diurnal destabilization will be greatest. Broad larger scale
forcing in the form of a positive-tilt upper trough and the right
rear entrance region of an upper level jet streak will support
synoptic scale ascent, though it remains to be seen if any
convectively-enhanced mid-level vort will emerge from loosely
organized convection currently upstream across KS/NE.
At this point only shaved slight chance pops a bit in the
southeast early Friday based on timing depicted by current suite
of CAM guidance. Could see being able to trim pops from the north
a little more quickly in the afternoon, but will hold off without
the full suite of 00Z runs available at this time.
Ratzer
&&
.SHORT TERM...
Issued at 356 PM CDT Thu Jun 30 2022
Through Friday night...
Most of the area is sitting underneath some mostly sunny skies on
this hot and dry afternoon. Parts of the western CWA are seeing some
cirrus moving overhead, a precursor to the approaching cold front,
which will steadily propagate over the rest of the CWA over the next
several hours. Mostly cloudy skies will follow in behind overnight
tonight and early tomorrow morning. Meanwhile, temperatures in the
upper 80`s and lower 90`s are accompanied by some breezy conditions
with gusts upwards of 25-30 mph, hence the elevated fire risk today.
Temperatures will fall into the upper 60`s and lower 70`s tonight
with winds dying down through the evening.
Tomorrow will be an eventful day weatherwise with a few rounds of
rain likely and thunderstorm chances that will be occupying most of
the day across the area. This is the result of a cold front passing
through the CWA through the first half of tomorrow. This front is
currently draped across NW Iowa and eastern Minnesota. As the front
approaches, a notable amount of moisture surges into the low and mid
levels following a very dry day today, although, admittedly,
moisture advection ahead of the front isn`t overly impressive. A
line of broken showers and potentially some embedded thunderstorms
is expected to move in along the boundary as it enters the area from
the northwest. Best guess on timing is roughly 4AM for rain to start
moving into the far northwestern CWA and will gradually propagate
southeastward from here. A couple of light thunderstorms are
certainly possible along the front during this time with several
hundred joules of CAPE stored up ahead of and along the boundary.
The better chances for storms a little later in the morning and into
the afternoon. It`s still questionable how much instability will
build up ahead of the front tomorrow. Although, we know that the
southern and eastern CWA will manage to accumulate the most
instability simply given that these areas will experience more
daytime heating prior to frontal passage. Guidance is showing
anywhere between approximately 800 and 1,200 joules of CAPE building
along and south of the Kankakee River basin which should do well to
result in at least a few thunderstorms as the front passes through
in the late morning and early afternoon. Decent low level lapse
rates with ample midlevel moisture in conjunction with a fair amount
of CAPE and perhaps a little help from an upper level jet streak
could result in some stronger storms featuring heavy rain and gusty
winds in the far southern CWA. A predominantly zonal shear profile
with some backing occurring in the mid levels should keep severe
chances rather low, but they are non-zero. The front will exit the
area to the southeast by the early-mid afternoon.
There is a good signal for post-frontal rain and storm chances
through tomorrow afternoon and evening. Perhaps the biggest question
revolving around post-frontal storm chances is how much instability
can build following the frontal passage. Areas along and north of I-
80 appear the most favorable for post-frontal storms given that the
front should pass over these areas early enough to still benefit
from plenty of diurnal heating and accumulate a good deal of CAPE
for the afternoon and evening. However, there is a large spread
among models in how much post-frontal CAPE will build up. The RAP is
by far the most aggressive throwing up over 2,500 joules of CAPE
over the western and southern suburbs in the afternoon. However,
this is a rather sizable outlier with most guidance sitting in the
ballpark of around 1,000 joules while some models are forecasting
closer to 500 joules. One thing to consider, however, is once the
front passes over, any storms that pop up will have to be primarily
heat-driven with an LFC near 825 hPa. There is some signal for a bit
of a kink in the mid level trough with some enhanced flow, though I
wouldn`t quite classify it as a shortwave as the signal is very
subtle. Convective-allowing guidance is roughly 50/50 on simulating
post-frontal storms vs just some scattered showers. Overnight and
into daybreak Saturday, the area will be primarily dry with steadily
clearing skies and perhaps just a couple of isolated showers in the
southern CWA.
Doom
&&
.LONG TERM...
Issued at 307 PM CDT Thu Jun 30 2022
Saturday through Thursday...
The weather messages for the holiday weekend into next week:
* Primarily dry Saturday-Sunday
* Warm Sunday into Independence Day, with increasing humidity
Monday though still not to high impact levels
* Gradually increasing potential for a more active pattern later
Independence Day through Tuesday and possibly beyond
This portion of the forecast starts on Saturday morning with the
cold front noted in the short term having stalled well to the
south of the area and weak high pressure of 1019 mb prevailing
over the region. This high will have ushered in some drier low-
level air, characterized by dew points mainly in the mid to upper
50s. Onshore flow, albeit light, will keep lakeside readings
about 10 degrees cooler than inland mid 80s. Overall forecast
soundings with these low level conditions are not supportive of
pop up showers or storms. A subtle short wave in the Upper
Missouri Valley on Saturday is shown to slowly weaken as it
progresses toward the region Saturday night. So the chance of a
shower or storm really seems on the low end.
Sunday is more of the same in terms of any chances of rain being
low. Soundings do try to show more of a cumulus signature and
possibly a little CAPE above that, but still marginal low-level
moisture, and a lack of any low-level confluence or subtle height
falls indicate the rain chances stay small. Temperatures will
inch warmer on the back side of the high and flow turns more
southerly. This will still be weak enough to allow lakeside
cooling into Illinois. A couple 90s for highs are possible.
A pattern shift then happens, largely aided by the anomalously
deep upper level low in eastern Canada shifting eastward and
responsive low-level warm and moist advection building into the
region from the south-southwest. Height rises build in during the
latter part of the weekend into the start of Monday on the
synoptic scale, however guidance does show a greater signal for
short wave energy translating from the lee of the Rockies into the
Upper Mississippi Valley/Corn Belt region. This aligns with where
the low-level theta-e return flow will be, and has had two
consecutive runs of long range guidance with the look of a
possible MCS pattern later Monday into Tuesday. With the forecast
guidance solutions at present, our forecast area would be in/near
the stripe of more active weather as the Plains low-level jet
points more toward our region. With modulation due to convective
effects common in such a setup, it is just simply too far to get
into any specifics, or to improve much from a "chance of
thunderstorms" forecast for that Monday into midweek period. But
will have to keep an eye out for some possible heavy rain / severe
thunderstorm chances.
This pattern will also dictate temperatures. For now, Independence
Day does looks hot with highs around 90 if unimpeded by convection
or convective clouds, which is most favored in the southern CWA.
Dew points look to be around 70, making it the most humid day of
the long holiday weekend.
MTF
&&
.AVIATION...
For the 00Z TAFs...
The primary aviation concerns through the TAF period are:
* Weakening winds this evening
* Chances for precipitation tomorrow morning and afternoon,
including a chance for thunder
* Trends in wind direction through the TAF period.
Breezy southwest winds this evening will continue to slacken with
gusts becoming far less common over the next few hours. Sustained
winds near or just about 10 kt should continue through the
overnight hours as a 30 to 35kt LLJ increases overhead. Toward
daybreak, winds may trend toward 270 degrees/westerly as a
weakening surface front approaches from the north. However,
confidence is lower than average on exactly how fast winds will
veer tomorrow morning.
High resolution model guidance continues to advertise the
potential for a subtle wave to develop in the Central Plains
tonight and move over northern Illinois at some point tomorrow
morning, allowing for a period of scattered showers at the
terminals. However, a range of outcomes remains in the available
model guidance, forcing lower than average coverage in a single,
deterministic TAF forecast. If the wave arrives toward daybreak, a
2-4 hour period of showers would become possible at all terminals
ending by noon. However, should the wave arrive later toward
early afternoon, chances for thunderstorms at the terminals would
increase given building instability. Cigs with any shower or
thunderstorm should remain VFR with a mid-level deck likely
prevailing regardless. After collaboration with CWSU ZAU, opted to
maintain the inherited structure of 6-7 hours of prevailing VCSH
with targeted 3-5 hour TEMPOs groups for explicit SHRA but with
slightly later timing than the previous TAF package. Adjustments
appear all but likely as trends emerge in the 00Z suite of high
resolution model guidance and upstream observations.
With a weak surface pressure gradient expected to be in place
tomorrow afternoon, winds may flip northeasterly off Lake Michgian
at all but RFD by late morning. Toward the end of the TAF period,
winds should become light and variable and clouds should clear.
Borchardt
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...None.
IN...None.
LM...None.
&&
$$
Visit us at weather.gov/chicago
Follow us on Facebook, Twitter, and YouTube at:
www.facebook.com/NWSChicago
www.twitter.com/NWSChicago
www.youtube.com/NWSChicago
Area Forecast Discussion...Updated Aviation
National Weather Service Saint Louis MO
1028 PM CDT Thu Jun 30 2022
.SHORT TERM... (Through Late Friday Night)
Issued at 235 PM CDT Thu Jun 30 2022
The surface ridge which brought us the past few days of spectacular
late June weather is in the process of washing out/moving east.
Temperatures are already a few degrees warmer than yesterday, but
dew points are remaining in the 50s for the most part which is
actually producing a heat index that`s lower than the air
temperature at this time!
Unfortunately this low humidity will not prevail, and higher dew
points are already sneaking up the Mississippi Valley toward us as
evidenced both in the surface observations, and a field of cumulus
stretching out on the southern periphery of the drier air. Upper
60s/lower 70s dew point temperatures will creep up into our area
tonight into early Friday, just in time to be met by a weak cold
front which will drift into northern Missouri/central Illinois
tomorrow morning. All short range guidance including the CAMs
produce some precip over our area on Friday...mainly during the
afternoon and evening. The GFS and RAP are showing 2000+ J/Kg
MLCAPE Friday afternoon coupled with 30-40kts of deep layer shear.
This is certainly enough to produce strong/severe thunderstorms
along the front Friday afternoon, however low level convergence
doesn`t seem to be particularly strong, particularly as forecast by
the GFS. Coverage may therefore be limited...but SPC`s new DY2
marginal risk in the vicinity of the front looks very reasonable.
Storms should diminish with loss of daytime heating Friday
evening...although weak warm advection aloft across Missouri may
continue to produce isolated to scattered convection through much of
the night, particularly toward dawn Saturday morning as convection
which develops over the Plains spreads east.
Carney
.LONG TERM... (Saturday through Next Thursday)
Issued at 235 PM CDT Thu Jun 30 2022
Latest guidance shows the flow aloft becoming quasi-zonal by
Saturday morning. The lack of upper level support will cause the
front to stall over the Mid Mississippi Valley and remain quasi-
stationary at least through Sunday morning, if not into Monday. The
position of the front will largely be determined by convection along
it through the weekend. However most deterministic guidance shows it
settling across southern Missouri and far southern Illinois or
western Kentucky Saturday, and waving back north due to southerly
low level flow, then storms form along it and is pushed south again.
As with the position of the front, temperatures will be widely
influenced by clouds and precipitation this weekend, particularly on
Saturday which looks potentially wetter than Sunday. Temperatures
may not get out of the 70s and low 80s where afternoon storms
develop, but areas that receive full sunshine could easily top 90
either day. The latest deterministic guidance points to northern
Missouri and west central Illinois as being cooler with more rain
Saturday afternoon as a short wave passes through the Lower Missouri
and Mid Mississippi Valley...however confidence in this panning out
exactly as forecast is low since this wave looks suspiciously like
grid scale convective feedback generated by convection over the
Plains late Friday night. Indeed, the NBM probabilistic forecast is
indicating considerable uncertainty with the temperature forecast.
It shows the 75th and 25th percentile high temperature forecasts for
Saturday in our CWFA as about 92 and 84 respectively. The 90th and
10th percentiles are 94 and 80! Sunday`s spread in high temperatures
is only a couple of degrees tighter. The NBM deterministic guidance
leans toward the higher end of that range both days (except in
northern Missouri/west central Illinois on Saturday due to clouds
and precip in the afternoon), and I agree with the warmer
temperatures...assuming there will be breaks in the clouds and
showers.
The front will finally get shoved back to the north on Monday and
Summer will return in full force. An upper level ridge will build
east from the Great Plains for Monday through Wednesday, bringing
temperatures solidly back into the 90s. There may be some afternoon
thunderstorms each day, but the potential doesn`t look that great
under the influence of the ridge, so have kept PoPs in the low
chance/slight chance range. Another short wave may break through
the ridge Wednesday night/Thursday to bring a weak cold front and
possibly some rain to the region; however predicting a FROPA 7 days
out in July is always a low-confidence forecast.
Carney
&&
.AVIATION... (For the 06z TAFs through 06z Friday Night)
Issued at 1024 PM CDT Thu Jun 30 2022
VFR flight conditions will prevail across the region tonight, and
potentially through the entire TAF period. The only threat to
aviation interests will be the threat for isolated thunderstorms
along a cold front that sags south tomorrow afternoon into the
Mid-Mississippi Valley.
The best chance for any convection will be in the afternoon along
the front, but latest guidance is indicating that storms will be
more isolated than previously forecast. While VCTS remains in the
TAFs at the terminals for a period of time tomorrow afternoon, it
is quite possible that no impacts are realized given how isolated
the convection could be. As the front passes through, winds will
shift out of the north/northeast Friday night.
MRB
&&
.PRELIMINARY POINT TEMPS/POPS...
Saint Louis 75 96 72 87 / 0 30 40 50
Quincy 69 86 65 81 / 5 40 20 50
Columbia 69 93 69 85 / 0 40 40 60
Jefferson City 69 96 70 87 / 0 30 30 50
Salem 71 94 71 87 / 0 20 30 50
Farmington 70 94 71 88 / 0 20 20 60
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...None.
IL...None.
&&
$$
WFO LSX
Area Forecast Discussion
National Weather Service Marquette MI
731 PM EDT Thu Jun 30 2022
.SHORT TERM...(Through early this evening)
Issued at 314 PM EDT THU JUN 30 2022
...Strong to severe storms late this afternoon into this
evening...
Clearing has been occurring from W to E so far today, which is
assisting with recharging the atmosphere for a redevelopment of
storms. Latest RAP analysis courtesy of SPC`s mesoanalysis page
indicates that 500 to 1000 ML-CAPE is building across the Wrn half
of the forecast area with the cap slowly eroding. Satellite
imagery is showing spatial cloud growth ahead of the previously
advertised approaching frontal boundary with some weak returns
appearing on regional radar underneath. Over the next several
hours, expect this general trend to continue, supported by a
rather warm, moist airmass at/near the surface. While there are
some variances in timing amongst the various deterministic model
guidance, general consensus is a 4 to 5pm EDT start time for
convective initiation, although may initially struggle until the
cap is able to be overcome. From 6pm EDT onward will be the
highest chances for convection, particularly of the strong to
severe kind. With 50+ knots of 0-6km bulk shear, 30+ kts within
the 0-3km layer, low- to mid- level LRs of at least 7 C/km already
in place, and around 100 or so m2/s2 of 0-3km SRH, strong to
severe storms are still expected. Wind will be the primary threat
but hail will be possible given the LRs, lowering fz lvls, and at
least some turning within cells. Moderate rain will be highly
probable in storms, with locally heavy rain possible. PWATs aren`t
overly impressive for this time of year, but as alluded to
already, plenty of at least LL moisture abounds.
.LONG TERM...(Tonight through Thursday)
Issued at 135 PM EDT THU JUN 30 2022
Medium range models and their ensembles suggest a relatively benign
period of weather after this evening with more rain chances
returning for Independence Day. Behind the passing cold front
tonight, models suggest a mid-level low to slowly shift east to the
north of the Great Lakes. Meanwhile, a low pressure system off the
Pac NW will drive a deep trof along the W Coast, forcing a
downstream ridge to build across the Rockies, with more zonal to NW
flow across the Upper Great Lakes. As the weekend wraps up, this
trof shifts inland as the ridge axis shifts east across the CONUS.
This transitory period will bring a chance for showers and
thunderstorms across the UP for the holiday festivities as a LLJ and
baroclinic axis shifts through the Upper Midwest. By the middle of
next week, models suggest a broad, but weak ridge to remain across
the CONUS with relatively good agreement in the models. Look for
temps to remain near- to below-normal through most of the period,
trending towards above normal by the middle of next week.
As a cold front shifts across the UP tonight, tsra will be
ongoing/developing across the western/central UP. Latest RAP
guidance suggests the cold front to move into the wern UP around
23/00z this evening as daytime heating(though limited some by AM
clouds) and gusty winds efficiently mix out the boundary layer.
Impressive low-level lapse rates combined with a cold front boundary
should be able to overcome a small cap seen on model soundings.
While the instability isn`t overly impressive, there is sufficient
amount of shear that should be able to bring a threat of severe
weather. Low-level shear for any potential tornadic threat will be
tied directly to the frontal axis, as winds become unidirectional
behind the fropa...though this threat appears quite limited. Rather
strong winds and isolated larger hail appears to be the main threats.
With a sfc high pressure system moving in behind the front, the
column begins to dry out quickly heading into Friday. PWAT values
near 1.75 inches Thursday, quickly fall to around 0.4 inches by
Friday, and will remain low through at least Saturday. This sfc high
pressure will drift across the UP through the weekend, bringing
tranquil conditions across the area.
By Sunday, the UP will be in a transitional pattern with southerly
flow returning in the afternoon. This will begin to bring in
increasing amounts of moisture for at least the west half; however,
with the high pressure shifting to the Eastern Great Lakes Sunday
afternoon, NE flow off the higher terrain of Ontario could bring
elevated fire wx conditions for the east half of the UP.
The pattern becomes a bit more unsettled for Independence Day into
Tuesday as a quasi-stationary baroclinic zone will bring multiple
chances for showers and thunderstorms across the Northern Plains and
Great Lakes regions through the middle of the week.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 730 PM EDT THU JUN 30 2022
TSRA and RA ends over IWD in the next hour or two, whereas SAW
should begin seeing SHRA and TSRAs move in within the next hour.
Some hail and strong winds could be seen with these TSRAs early this
evening, as a few storms could be severe; MVFR conditions or lower
could be seen for a few minutes in the strongest parts of these
storms. Once we get past midnight, expect much calmer conditions,
with winds veering to the NW and VFR conditions dominating for the
rest of the period as a high pressure ridge moves overhead.
&&
.MARINE...(For the 4 AM Lake Superior forecast issuance)
Issued at 135 PM EDT THU JUN 30 2022
SW winds today will veer to the W to NW tonight behind a cold front.
Showers and thunderstorms are expected to develop along this frontal
axis, which could bring some localized gusty winds. By Friday,
surface high pressure will move over the lake, bringing benign
conditions through the weekend. As the high pressure moves into the
area, brief SW winds up to 20 knots will be possible across the west
half of the lake through Friday afternoon. Showers and thunderstorms
return for Independence Day into Tuesday, but winds appear on the
lighter side outside of any thunderstorms, before another high
pressure crosses the lake Wednesday.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
Beach Hazards Statement until 10 PM EDT this evening for MIZ014.
Lake Superior...
None.
Lake Michigan...
None.
&&
$$
SHORT TERM...lg
LONG TERM...JAW
AVIATION...TAP
MARINE...JAW
Area Forecast Discussion
National Weather Service Pocatello ID
320 PM MDT Thu Jun 30 2022
.SHORT TERM...Tonight through Friday night.
Weak high pressure over the region will keep weather fairly quiet
and temperatures slightly above normal today and tomorrow. High-
resolution models keep monsoonal moisture restricted to the far
eastern portion of our CWA, resulting in isolated showers and
limited convection across the eastern highlands this evening and
again tomorrow. The QPF associated with these showers and storms is
unimpressive and totals will generally range from a trace to 0.15"
tomorrow afternoon through evening. Expect breezy conditions across
the Central Mtns. tonight and again tomorrow, as well as for the
Upper Snake River Plane. Winds across the ridgetops of the Central
Mtns. could reach 30 mph tomorrow evening, with elevated winds
shifting further south across the Upper Snake Plain during the later
evening. Cropp
.LONG TERM...Saturday through next Thursday night.
There are two halves to this forecast. Up through Mon night is
the unstable, showery, and breezy to windy part. The Tue through
Thu night forecast is a dry and hot forecast. So, for part I a low
moving in from the Pacific, its low center getting onshore Sun
night. The southwest to southerly flow ahead of the low brings up
subtropical moisture and, combined with heating, generates
afternoon showers and thunderstorms for Sat through Mon. On Sat,
the threat of showers and thunderstorms is nearly everywhere, but
barely gets to chance threat in the upper Snake highlands. On Sun
and Mon, the showers and thunderstorms have a greater chance of
occurrence, getting to nearly likely at the ID- MT border, but
should cover only the central Idaho mountains, the upper Snake
highlands south to Swan Valley, and the extreme north end of the
Snake River plain. On Independence Day, the shower and
thunderstorm threat is limited to the northern half of the central
Idaho mountains and the ID-MT border region. The low will pass to
the north, and on Mon it sweeps a trough through eastern Idaho
during the day. This will mainly bring breezy to windy conditions
to the eastern Magic Valley and Snake River plain, with the
strongest wind (gusts up to 30 mph) over the Mud Lake region, Arco
Desert, and INL property. The wind will decrease after 900 pm to
10 to 15 mph, so perhaps not too impactful for the nighttime
fireworks shows. So stay tuned.
For the second half of the period, the upper level ridge reasserts
itself over the northern Great Basin. Strong warming will return
temperatures to the lower 90s in the Snake River plain by Wed, and
middle 90s on Thu. There are even some outlier guidance indicating
temperatures over 100 deg F for some valley locations on and after
Thu. Wind should be light and slope-valley driven with the upper
level ridge axis to the east. Messick
&&
.AVIATION...Just some occasional mid-level cloudiness, but the HRRR
indicates some isolated showers with the second round of clouds that
comes late tonight, around 01/05Z until 01/11Z when considering all
the airdromes. As these showers and clouds move in, the wind gets
fairly variable, the returns to the northerly to easterly flow that
is typical of drainage or slope-valley wind.
The only exception to the airports for the clouds and showers is
KSUN, which is far enough north and west to stay SKC and have its
normal slope-valley wind, which should stay light. Messick
&&
.FIRE WEATHER...Weak showers developed over the southern Sawtooth NF
and the Caribou-Targhee NF, but thunderstorm activity should stay
south of the Idaho border, in Utah. However, there is a slight risk
for the Bear Lake basin to see a thunderstorm tonight. Otherwise,
another round of light showers is possible late tonight over the
same area. On Fri, as a low in the Pacific gets closer, the wind
shifts more and more southerly, bringing up warm and moist air. This
will bring back thunderstorm activity, but cloud cover will make the
temperature change very little. Humidity will be up slightly, with
fewer areas of afternoon humidity getting below 15 percent. Showers
and thunderstorms continue for Sat. For Sun and Mon, the showers and
thunderstorms will be limited more to the northern half of the
forecast area. The low will have made land fall in Oregon on Sun
night. This will bring it close enough where a weak cold front,
rotating from south to north, will bring breezy to windy conditions
to the entire forecast area. On Tue, a fairly quick and radical
change develops as high pressure returns. Temperatures are expect to
spike up into the 90s for the lower elevations by Wed, and humidity
will crash strongly. On the brighter side, the thunderstorm activity
ceases. Messick
&&
.PIH WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
Area Forecast Discussion
National Weather Service Las Vegas NV
729 PM PDT Thu Jun 30 2022
.SYNOPSIS...Another day of isolated thunderstorm activity expected
for eastern Mohave County today before dry air moves into the
region. Troughing will bring gusty south-southwest winds this
holiday weekend, resulting in increased fire danger for southern
Nevada and northwestern Arizona. Otherwise, temperatures will drop
below average for the start of the work week, slowly increasing into
next weekend.
&&
.Update...Showers and isolated thunderstorms continue to dissipate
this evening and should end by 9 PM with mostly clear skies expected
overnight. We can expect to see another day of isolated afternoon
and early evening showers and thunderstorms mainly across northern
Mohave County as drier air begins to work in from the west. This
will bring breezy to windy conditions over the weekend along with an
increase in fire weather concerns.
&&
PREV DISCUSSION
137 PM PDT Thu Jun 30 2022
.DISCUSSION...Today through next Thursday.
One more day of isolated convection expected across portions of
Mohave County this afternoon. PWATs upward of an inch continue
across the western Mojave Desert, extending as far north as the
Arizona Strip. Despite numerous days of isolated-to-scattered
convection in the area this week, the low levels of Mohave County
remain dry, as shown by forecast inverted-V HRRR soundings. CAPE
values in northern Mohave are modest, around 250 J/kg, with DCAPE
between 1000 and 1500 J/kg. As such, gusty winds will be the primary
threat from storms that develop, but isolated flash flooding cannot
be ruled out, particularly in the event of training storms. PWATs
will be quick to retreat through the day on Friday as the monsoonal
high shifts eastward.
The primary focus of the forecast period becomes an incoming dry
trough that will enhance fire danger across southern Nevada and
northwestern Arizona through Independence Day weekend. In general,
skies will be clear and temperatures will be a few degrees below
seasonal normals, making for a seemingly pleasant (respectively)
Independence Day weekend. However, due to the incoming trough, ECMWF
EFI shows seasonally abnormal winds picking up across the southern
Great Basin this weekend. These gusty south-southwest winds will
pick up through the day on Saturday, with sustained winds around 20
mph and gusts to 35 mph. Winds will peak on Sunday, with gusts 30-40
mph across southern Nevada and northwestern Arizona. Lincoln County,
Nevada will experience the strongest winds on Sunday, with gusts to
45 mph possible as the closed low associated with this trough pushes
inland. Finally, south-southwest winds return on Monday with similar
speeds as Saturday. As such, a Fire Weather Watch has been hoisted
for southern Nevada and northwestern Arizona from Saturday morning
through Monday evening due to strong winds, afternoon relative
humidities in the lower-teens to single-digits, and increased
firework activity. Outdoor burning and firework usage is not advised
in these areas due to the increased chance of wildfire starts and
spread.
Otherwise, temperatures will bottom out on Monday with 4-6 degrees
below seasonal normals as the trough moves northeastward out of the
region. Heights will rise through the remainder of the week as
ridging builds back into the Desert Southwest, with temperatures
above-average going into next weekend.
&&
.FIRE WEATHER...Increased fire danger expected this weekend due to
an influx of dry air from an incoming trough. Gusty south-southwest
winds across southern Nevada and northwestern Arizona will pick up
Saturday, peak Sunday afternoon, and gradually diminish on Monday.
Strongest winds will focus in the southeastern Great Basin. Coupled
with afternoon relative humidities in the single-digits to upper-
teens, there will be increased chances of wildfire starts and
spreads. Fire Weather Watch in effect Saturday morning through
Monday evening. Outdoor burning and firework activity during this
time is ill-advised.
&&
.AVIATION...For Harry Reid...South southwest winds gusting around 25
knots will settle down to around 10 knots sustained after sunset.
There could be a short period of southeast winds Friday morning
before the gusty south southwest winds return around midday.
Slightly stronger gusts are expected Saturday with the strongest
gusts likely Sunday. No operationally significant clouds or weather
expected.
For the rest of southern Nevada, northwest Arizona and southeast
California...Aside from isolated thunderstorms in eastern Mohave
County this afternoon and early evening, dry weather is expected
areawide through the weekend. Southwesterly breezes are expected
each afternoon and evening, with gusts 20 to 25 knots Friday
afternoon increasing a few knots Saturday afternoon and a few more
knots Sunday afternoon, which is expected to be the strongest wind
day.
&&
.SPOTTER INFORMATION STATEMENT...Spotters are encouraged to report
any significant weather or impacts according to standard operating
procedures.
&&
$$
UPDATE...Gorelow
DISCUSSION...Varian
AVIATION...Morgan
For more forecast information...see us on our webpage:
https://weather.gov/lasvegas or follow us on Facebook and Twitter