Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 07/01/24
See below for an aviation forecast discussion for the 00Z TAFs.
&&
.SHORT TERM /THIS EVENING THROUGH MONDAY NIGHT/...
Issued at 210 PM CDT Sun Jun 30 2024
Winds will remain elevated as we move into Monday. Winds gusting 30-
35kts have been common west of the MO River, with a few higher
values. The 2 to 3mb pressure falls in 6 hours due to the tight
pressure gradient between the surface high over eastern MN/WI and
low across WY will continue to spread east this evening. While
winds will relax around 5kts, they will remain gusty through
Monday. The low across WY will push into the western Dakotas early
Monday morning.
Storms over western ND overnight may clip our western, but mainly
far northwestern counties 09-13Z Monday. While the main threat for
strong to severe storms in the form of hail around 1" in diameter or
winds around 60mph will be across far western ND, there is still a
Marginal Risk (level 1 out of 5) of severe weather for counties
mainly west of the MO River.
Low level moisture will steadily increase during the daytime hours
Monday, with relative humidity values staying at or above 60
percent during the day Monday. The 12Z runs of the NSSL WRF and NAM
Nest have been a little more robust with the showers and a few
thunderstorms developing over our eastern SD counties and remaining
through much of the daytime hours. We have steadily increasing
chances of precipitation (increasing from 20 to 70 percent)
through the day. There are differences in when thunderstorms will
develop or move over central SD Monday. The latest HRRR and and a
couple of the FV3 runs indicate the potential as early as 21Z,
others hold off until late afternoon with the storms developing
over eastern WY/Black Hills of SD sliding into our western
counties around 00Z. Much of this could be a result of the warmer
air aloft capping some of the convection. The NAM is near 14C over
central SD, while the HRRR is closer to 11C (weaker capping).
There is plenty of room for change in this period, so we will
continue to highlight that people be prepared for strong to severe
storms as early as mid afternoon with golf ball sized hail and
winds over 60-70mph, along with a tornado threat over central SD
(2% tor off the latest SPC convective outlook). CAPE values peak
across central SD 15Z Monday to 00Z Tuesday, with 0-3km computed
cape values of 1500 to around 2000 J/kg, diminishing significantly
after 00Z. A similar trend is noted with shear and lapse rates,
diminishing as storms move east.
Winds will diminish to less than 15kts Monday night as the surface
trough tracks east and resides either near the SD/MN border or all
into MN by 12Z Tuesday.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
Issued at 210 PM CDT Sun Jun 30 2024
A passing upper level long wave trough, cold air advection and steep
low level lapse rates may result in daytime heating showers and
thunderstorms Thursday afternoon. Expect anything that can get going
will be isolated in nature. Perhaps just enough CAPE (~ensemble mean
500 J/KG) to get a stronger pulse storm or two, but the severe
threat is low at this time.
High pressure will make a brief appearance Tuesday night/Wednesday
morning, but won`t last long as the next system moves into the
region Wednesday night and Thursday. A strong closed low system is
expected to develop and slide across the north plains Thursday
afternoon. Current model timing and location of this system varies
pretty significantly, so forecast confidence is low. A few solutions
bring a more defined surface low with a warm front lifting over our
eastern CWA resulting in a longer period of unstable air over the
region. While other solutions have a very ill defined surface
pressure pattern or keep the low east of our CWA altogether,
resulting in a cooler, more stable airmass. It is a pretty large,
slow moving system however, so rainfall may linger into Friday
afternoon before exiting the region. Models are generous in their
QPF, and the WPC values are currently over an inch for the eastern
2/3 of the CWA.
Models really diverge toward the weekend and early next week. Some
solutions try to build high amplitude ridge over the southwest
CONUS, placing us into a persistent northwest flow aloft. Whereas
other models maintain a more zonal flow first, before making the
transition to northwest flow aloft.
&&
.AVIATION /00Z TAFS THROUGH 00Z MONDAY/...
Issued at 624 PM CDT Sun Jun 30 2024
Terminals KABR,KATY,KPIR,KMBG
VFR conditions are forecast to persist until Monday morning, at
which point sub-VFR stratus is forecast to materialize as low
level moisture increases into the region on these southerly winds
of 15 to 25 knots with gusts up to 35 knots.
There could be a shower or thunderstorm at/near KMBG Monday
morning (~11Z to 15Z). Otherwise, there are increasing chances at
all four terminals for a shower or thunderstorm after 21Z Monday.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...None.
MN...None.
&&
$$
UPDATE...Dorn
SHORT TERM...KF
LONG TERM...Serr
AVIATION...Dorn
Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
229 PM AKDT Sun Jun 30 2024
.SYNOPSIS...
Warm weather will continue over much of the Interior through the
weekend and into early next week. Areas of dense smoke from fires
burning is reducing visibilities over the Middle Tanana Valley.
Smoke is very thick and unhealthy around the Fairbanks area today.
Dense smoke advisories expected to continue into Monday. Isolated
storms will persist into the weekend.
&&
.DISCUSSION...
Analysis and Model Discussion...
A strong vertically stacked low will remain in the central Bering
Sea then drift across the Aleutians on Sunday as a 540 dam Low.
Ridging will persist over the Interior this weekend. A trough will
push across the eastern North slope late Sunday into Monday. A
strong shortwave over Russia will push a front across Northwest
Alaska Tuesday into Wed bringing heavy rainfall and strong winds.
Ridging over the Interior will slowly break down Monday and
Tuesday. Models in good agreement through the short term. The HRRR
smoke model showing smoke persisting over the Interior through
Monday.
Interior...Warm weather will continue over much of the Interior
through the weekend. Highs in the mid 80s and a few upper 80s over
the Yukon Flats. Air across Fairbanks and North Pole is very
unhealthy today. Dense smoke advisories have been extended into
Monday. Smoke may thin and visibility may improve late Monday
and Tuesday as winds become westerly and disperse some of the
stagnant smoke. Isolated to widely scattered thunderstorms return
over the southern Interior on Sunday. A cooler and wetter pattern
expected by late Wed into Thursday as a front will bring much
needed wetting rains to the Interior. Southwest flow will continue
into late next week with more chances for rain.
West Coast and Western Interior... Western Interior will remain
warm over the weekend with highs in the upper 70s to low 80s.
Showers continue to rotate around the Yukon Delta from the low in
the southern Bering through the weekend. Widely scattered
thunderstorms are possible from Grayling to Mcgrath on Sunday.
Some of these storms will be fairly strong and may produce small
hail and gusty winds with copious lightning. Monday is another
warm day, with increasing southwesterly winds as a low approaches
the NW Arctic. Change in the pattern by Tuesday with temps
cooling and a front bringing rain showers to the west coast. Temps
could drop to the 60s Tuesday into Wednesday.
North Slope and Brooks Range...Isolated thunderstorms are again
possible Sunday mainly over the E Brooks Range, with some showers
on Monday over the crest of the range. Otherwise, weak high
pressure along the coast will promote periods of sun and
stratus/fog at times, although it will not be extremely
widespread. Tuesday into Wednesday, a strong front originating
from E Siberia will push across the entire region bringing heavy
rainfall and strong southwest winds 15 to 30 mph with higher
mountain gap winds.
Extended Forecast Days 4-7...Long range models are coming more
inline with a fairly large pattern shift beginning Tuesday, as a
front from E Siberia moves inland across the NW Arctic and shifts
east along the Brooks Range and eventually into the Interior on
Thursday. This will bring increasing west-southwest winds across
the Mainland with increasing chances for rainfall and cooler
temps.
Coastal Hazard Potential Days 3 and 4...Strong southwest winds to
gale force will bring elevated water levels of 2 to 3 feet above
the normal high tideline from Norton Sound to the Chukchi coast
beginning Tue and lasting into late week.
&&
.FIRE WEATHER...
Warm and relatively dry over the Interior through the weekend and
into early Next week. Smoke and unhealthy air continues over the
Middle Tanana Valley down to Delta Junction. Dense Smoke Advisories
still in effect through Monday. On Sunday, isolated to widely
scattered thunderstorms return over the southern Interior and
western Interior from Grayling to McGrath.
Major pattern shift begins Tue and Wed as the upper ridge breaks
down and a strong front moves into the NW Arctic and shifts east
through the week, bringing potential wetting rains and much cooler
temps, although strong southwest winds may create some critical fire
weather conditions prior to that. Near red flag conditions
possible on Tuesday over the northern Interior and possibly
continuing into Wednesday for the Yukon Flats. The Red flag
conditions will be short lived with wetting rains moving across
the Interior on Thursday.
&&
.HYDROLOGY...
Glacial fed rivers including the Tanana are slowly rising as
warming temperatures lead to increased high elevation snowmelt and
glacial melt.
Beginning next week around Wednesday, heavy rainfall will move
across the W Brooks Range with 1-3 inches of rainfall through next
weekend, with 0.75 to 1.5 inches over parts of the Interior.
Expect river rises with this amount of water across the Mainland.
&&
.AFG WATCHES/WARNINGS/ADVISORIES...
AK...Dense Smoke Advisory for AKZ834-837-839>844.
PK...Small Craft Advisory for PKZ851.
&&
$$
Area Forecast Discussion
National Weather Service Bismarck ND
945 PM CDT Sun Jun 30 2024
.KEY MESSAGES...
- Isolated to scattered strong to severe thunderstorms are
possible tonight, with up to a Level 2 of 5 risk in portions
of the far west and a level 1 of 5 risk over the rest of the
area. The main hazards are hail up to quarter size, and wind
gusts up to 60 mph.
- Breezy conditions are expected tonight.
- There is a Level 2 of 5 risk for severe thunderstorms Monday
in southern North Dakota, and a Level 1 of 5 risk for much of
the rest of the area. The main hazards are hail up to ping
pong ball size and wind gusts up to 60 mph.
- The chance for showers and thunderstorms on Independence Day
is 60 to 80 percent across all of western and central North
Dakota.
&&
.UPDATE...
Issued at 920 PM CDT Sun Jun 30 2024
Thunderstorms have increased over southeast Montana over the
past hour from around Garfield and Hysham east to Miles City.
This is within an areas of strong low level and mid level lapse
rates and MUCAPE up to 2000 J/KG. Coordinating with SPC GGW and
BYZ, will be issuing a Severe thunderstorm watch that includes
Golden Valley, Billings and McKenzie counties in North Dakota.
Uncertain about the eastward extent of the convection, but with
current activity increasing and the low level jet expected to
increase think it`s warranted to include at least a portion of
ND in the watch. Will always be able to then cancel of things
don`t pan out, or expand a bit later if needed. Updated text
products will be transmitted shortly.
UPDATE
Issued at 603 PM CDT Sun Jun 30 2024
Thunderstorms continue over central ND and are also develop in
the higher elevations of Wyoming and southeast Montana. , as
well as around the Black Hills. Any convection over southeast
Montana would have a hard time making it into the state this
evening. Later this evening and overnight, aided by an
increasing low level jet, convection from Montana will have a
better probability of making it into western ND, and perhaps
strong to severe. Until then, look for breezy to windy
conditions this evening with variable cloudiness. Made some
small adjustments to sky cover with more cloud over eastern
portions of central ND early this evening and then increasing
clouds late from west to east.
&&
.DISCUSSION...
Issued at 314 PM CDT Sun Jun 30 2024
This afternoon, a very shallow upper ridge was moving over
eastern Montana, with an upstream trough deepening over the
Pacific Northwest. At the surface, a low pressure continued to
deepen over northern Wyoming, while a broad surface high
stretched across Minnesota, creating breezy to windy southeast
winds across western/central North Dakota in between these
surface features. These winds have been gusting up to around 40
mph, but have been staying below advisory criteria as expected.
Scattered radar returns have been persistent through the day,
although with such high cloud bases, these have been virga, with
no evidence of precipitation making it to the ground.
The main forecast concern tonight is the potential for strong to
severe thunderstorms, particularly across western North Dakota.
High-res guidance has been painting a similar picture through
the morning, with convection developing off the higher terrain
in central Montana later this afternoon ahead of the trough base
before moving east into North Dakota. A 50kt low- level jet is
also forecast to develop over eastern Montana and western North
Dakota late this evening. Moisture will be a bit lacking, with
both current and upstream dewpoints (as far south as Nebraska)
only in the 50s, and the 12Z HREF paints a narrow plume of
MUCAPE values of 1000-1500 J/kg across western North Dakota. The
main concern we see at this point is that forecast soundings
continue to advertise significant capping across the entire
forecast area. Although a Level 2 of 5 risk does extend into far
western North Dakota, at this point the potential for any severe
thunderstorms tonight is quite conditional, but recent CAMs runs
support the idea that convection will weaken as it crosses into
North Dakota. The low-level jet will sustained scattered showers
and thunderstorms, however, as the wave moves west to east
across the forecast area through the night.
As the previous shift noted, there is a low but non-zero chance
for storms to re-intensify as they get further into central
North Dakota late tonight into Monday morning, entering an
environment with slightly greater moisture. We are still
carrying the Marginal Risk (level 1 of 5) across most of our
central counties, which seems appropriate to cover this
potential.
The convection overnight and into Monday morning is a large
forecast concern in determining how the potential severe
thunderstorm threat on Monday will evolve. The deeper trough
base aloft will approach from Montana, while at the surface a
weak cold front and surface low will progress west to east
through the day. Continued southerly low-level flow and richer
moisture will boost dew points into the 60s, with a plume of
higher instability extending north-south across the central
Dakotas and overlaid with around 40 knots of 0-6km shear. CAMs
are consistent in developing scattered storms across much of the
Dakotas, although are inconsistent in storm mode and
progression through the evening. HRRR forecast soundings
advertise long hodographs, favoring a hail threat, although the
uncertainty in storm mode is still a concern when deciding the
threat ceiling. We did decide to increase the hail size in our
messaging to up to the size of ping pong balls, and kept the
damaging wind gust magnitude at 60 mph.
Storms exit the area through Monday evening, but precipitation
chances return briefly on Tuesday as a transient wave moves
through cyclonic flow aloft. The active pattern is the main
story of the work week as we stay in a broad troughing pattern,
with temperatures near to slightly below normal Monday through
Wednesday.
Unfortunately, chances for precipitation on Independence Day
continue to increase, with the latest blended POPs advertising
widespread 60 to 80 percent chances of rain through the day.
Ensemble members are honing on a deep trough base and
potentially closed low moving through the Northern Plains
Thursday into Friday, bringing showers and thunderstorms to the
area. CSU Machine learning probabilities continue to show a
low chance for severe weather on the holiday, however. With
this wave of precipitation, most locations have a 50 percent
chance of at least 0.25" of rain. Thursday also looks like the
coolest day of the extended period based on NBM temperature
percentiles, with highs in the lower to mid 70s. Behind the
upper trough, ridging is likely to begin building over parts of
the western CONUS, leading to warmer temperatures on Friday and
Saturday.
Ensemble members are then advertising a few different solutions
regarding the evolution of the synoptic pattern. Guidance is
split on where the ridge axis will be located by the end of the
weekend, with one potential solution having it over the Northern
Rockies, while another has it much further west off the coast
of British Columbia with subsequent downstream region over the
Northern Plains. There seems to have been a slight downward
trend in potential high temperature ranges from the latest NBM
runs, although precipitation chances still look relatively low
starting Saturday and continuing into the middle of next week.
&&
.AVIATION /00Z TAFS THROUGH 00Z MONDAY/...
Issued at 603 PM CDT Sun Jun 30 2024
Strong southeast winds to begin the 00Z Taf period.
Thunderstorms move west to east across the area late this
evening through Monday morning, and redevelop again Monday
afternoon, especially from around KBIS to KJMS. LLWS is possible
over mainly the southern TAF sites for a period tonight. Widespread
MVFR to IFR ceilings are also possible over a large portion of
the forecast area late tonight into Monday.
VFR conditions initially with strong southeast surface winds.
Winds remain breezy through the night. We also kept the LLWS
across the southern TAF sites of KDIK-KBIS and KJMS with a low
level jet developing. Strong southeast winds remain over central
ND MOnday but shift west over western ND. Thunderstorm activity
moves into western ND late this evening and tracks across the
forecast areas through the overnight hours. Brief Strong winds
and MVFR cigs/vsbys possible in any storm but in general as
showers and thunderstorms move through, low level stratus may
develop in their wake and remain into Monday morning and
potentially through the afternoon for portions of central ND. On
Monday, once showers and thunderstorms exit during the morning,
there will be another chance for showers and thunderstorms in
the afternoon, with the highest chances extending from KBIS east
to KJMS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
UPDATE...TWH
DISCUSSION...Jones
AVIATION...TWH
Area Forecast Discussion
National Weather Service Boston/Norton MA
1118 PM EDT Sun Jun 30 2024
.SYNOPSIS...
A strong cold front will move off the coast tonight pushing
showers and thunderstorms offshore. An upper level disturbance
will bring hit or miss showers Monday and possibly an isolated
thunderstorm, otherwise dry weather with below normal
temperatures. High pressure brings dry weather, seasonably warm
temperatures and low levels of humidity for Tuesday and
Wednesday. Turning more humid and unsettled for the Fourth of
July thru the early part of the weekend with a couple of
disturbances offering chances for showers and thunderstorms.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
11 PM Update...
Highlights
* Dry for most other than portions of the south coast where
showers/storms will be exiting offshore as the night
progresses.
* Humidity levels and cloud cover decreasing elsewhere. Lows
around seasonable levels.
The main shortwave that triggered earlier convection is offshore
at this point. A trough will dig into the eastern Great Lakes
late tonight. The cold front is in the process of working its
way through southern New England. Will completely slide through
by late tonight. A surface trough will extend from a low riding
along the front into southern New England.
Main change in the latest update from the previous forecast was
to focus the shower/storm risk more to portions of the south
coast. This is where there is still a few hundred to 1000 J/kg
of MUCAPE in place. Really will mostly be focused for Nantucket
and Marthas Vineyard, but could see some activity leak into the
Cape. Not anticipating any strong to severe activity in this
area given the marine layer is place and any storms would have
quite the inversion layer to overcome per latest RAP guidance.
Rest of the forecast generally on track with cloud cover
decreasing and humidity levels dropping as flow turns more NW to
N as the night progresses. Think that despite some areas
receiving rain will be tough for fog formation as the boundary
layer should be pretty well mixed as colder air is filtering in.
Anticipate it remains breezy overnight with 10-15 mph winds and
gusts up to 20 mph at times. Low temps around seasonable levels
in the 60s.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
Monday...
Sharp mid level trough with cold pool will be moving across the
region with 500 mb temps dropping to -16 to -18C. This cold pool
combined with daytime heating will result in BKN CU developing along
with widely scattered showers, mainly east of the CT valley and
especially across eastern MA. Marginal instability develops with
CAPES up to 500 J/kg so can`t rule out an isolated t-storm with
small hail given cold temps aloft. Temps will be a bit below normal
in post-frontal airmass with highs in the 70s and dewpoints in the
50s, to lower 60s near the coast.
Monday night...
Mid level trough moves offshore with rising heights as high pres
builds in from the west. Any diurnal clouds will melt away in the
evening leading to a mostly clear and somewhat cool night with light
north winds. Lows will range through the 50s, except lower 60s outer
Cape/Islands and Boston metro.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
Highlights:
* Dry and warm with tolerable humidity levels for Tue and Wed.
* Turning more humid and active for Independence Day, and
potentially into Fri/Sat too, with clouds, showers and storms
possible. Exact timing remains uncertain.
30/00Z guidance suite was in rather good agreement with the overall
synoptic pattern. Broad mid level ridging to start out this portion
of the forecast is expected to transition to broad troughing towards
next weekend. At the surface, a large high pressure should be over
southern New England Tuesday into Wednesday. This high pressure
should be far enough offshore to permit a cold front to approach
from the west on Independence Day, but it is a little complicated.
The offshore high pressure may not permit this front to make it all
the way into, or through, our region before being driven back north.
Dry weather with near to slightly above normal temperatures Tuesday
and Wednesday. Increasing risk for some showers and isolated
thunderstorms Wednesday night into Thursday. Also expecting
increased humidity with above normal temperatures Thursday into
Saturday. The timing and coverage of these showers and thunderstorms
remains the most uncertain aspect of this forecast. With many
outdoor plans for the holiday, it would be best to monitor the
forecast over the coming days.
This uncertainty lingers late this week. As such, stayed close the
NationalBlend solution for now, as it is ensemble-based. This meant
a broad chance for showers and thunderstorms Friday into Saturday,
but am not expecting it to be raining this entire time.
&&
.AVIATION /03Z MONDAY THROUGH FRIDAY/...
Forecast Confidence Levels:
Low - less than 30 percent.
Moderate - 30 to 60 percent.
High - greater than 60 percent.
Tonight...Moderate confidence.
Showers and t-storms especially south of the MA Pike will end
from N to S through midnight. VFR interior with partial clearing
overnight. IFR-LIFR south coast and Cape/Islands improving to
VFR after midnight but lower cigs lingering at ACK. Wind shift
to NW 00-06z from W to E.
Monday...High confidence.
VFR cigs 4-6k ft developing with scattered showers developing
late morning through the afternoon, especially eastern MA. Can`t
rule out an isolated t-storm with small hail. N wind gusts to
20 kt.
Monday night...High confidence.
VFR with diminishing wind.
KBOS TAF...Moderate confidence in TAF.
Expect a few t-storms developing 20-00z with brief lower
conditions and potential for strong wind gusts. Included a
TEMPO group to highlight this potential. Otherwise VFR. SW
winds shift to W this evening then NW overnight.
KBDL TAF...Moderate confidence in TAF.
One cluster of t-storms moving to the E but expect additional
showers and storms into early evening. VFR but brief lower
conditions and strong wind gusts in any storms. Wind shift to
NW around 00z.
Outlook /Tuesday through Friday/...
Wednesday: VFR. Breezy.
Wednesday Night: VFR. Breezy. Slight chance SHRA.
Independence Day: Mainly VFR, with local MVFR possible. Breezy.
Slight chance SHRA.
Thursday Night: VFR. Breezy. Slight chance SHRA.
Friday through Saturday: Chance SHRA.
&&
.MARINE...
Forecaster Confidence Levels:
Low - less than 30 percent.
Medium - 30 to 60 percent.
High - greater than 60 percent.
Tonight through Monday night...High confidence.
Gusty S-SW winds to 25 kt will be diminishing this evening as
modest low level jet moves offshore. Winds shift to NW overnight
then N during Monday with gusts to 20 kt. Diminishing N winds
Mon night. Showers and t-storms through this evening, moving
offshore from the south coastal waters late tonight.
Outlook /Tuesday through Friday/...
Wednesday: Winds less than 25 kt.
Wednesday Night: Winds less than 25 kt. Slight chance of rain
showers.
Independence Day through Thursday Night: Winds less than 25 kt.
Seas locally approaching 5 ft. Slight chance of rain showers.
Friday through Friday Night: Winds less than 25 kt. Seas
locally approaching 5 ft. Chance of rain showers.
Saturday: Winds less than 25 kt. Areas of seas approaching
5 ft. Chance of rain showers.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...None.
RI...None.
MARINE...Small Craft Advisory until 6 AM EDT Monday for ANZ254>256.
&&
$$
SYNOPSIS...KJC
NEAR TERM...KJC/BL
SHORT TERM...KJC
LONG TERM...Belk
AVIATION...Belk/KJC/BW
MARINE...Belk/KJC
Area Forecast Discussion
National Weather Service Charleston SC
1039 PM EDT Sun Jun 30 2024
.SYNOPSIS...
A cold front will impact the area Monday into Tuesday before
dissipating offshore. High pressure will return for the latter
half of the week.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
The strong ridging aloft has weakened enough with a short wave
moving through, and that along with the associated slightly
lower heights, and an approaching cold front has allowed for
convection to occur.
That convection has congealed into cold pool clusters, which
continues to ride south and southeast along a moisture axis and
also where we find higher Theta-e air, plus the better MLCAPE.
We show 50-70% PoPs as a result from northern Colleton, Hampton,
and Allendale, into the interior counties of Georgia. Rainfall
rates of at least 2-3 inches an hour in some areas will produce
some minor flooding concerns, as PWat is 2.4 to 2.6 inches. The
DCAPE is less than earlier, down to just 500-600 J/kg. So there
is only a small chance of isolated gusts in excess of 40 mph in
the stronger storms. Lightning networks are not showing any
diminishing trend as of late Sunday, and with echo tops in
excess of 45 or 50K feet, and cloud top temperatures as cold as
minus 70-75C, it could be awhile before lightning diminishes.
The HRRR has been doing an excellent job of depicting the more
southward movement to convection, showing it mostly avoiding the
Charleston Tri-County district. It also has greater Georgia of
the convection making it to the Savannah area, where we have 40%
PoPs occurring after midnight.
The bulk of the convection will be over with after about 3 am,
although given lingering boundaries there could still be some
isolated activity after that time.
It`ll be another warm and muggy night even with the storms,
since dew points are still so high. In general low temperatures
will be just in the mid and upper 70s, with even some coastal
sites not dropping below 80F degrees. The temperature at KCHS
for June 30 could be a record high minimum if it doesn`t rain
between now and the end of the day (See CLIMATE section below).
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY/...
Monday: Models continue to advertise a heavy rain/flooding
signal along parts of the Georgia and lower/middle South
Carolina coast for Monday. Subtropical ridging aloft will
quickly give way to broad troughing along much of the Eastern
Seaboard during the day as pronounced shortwave energy embedded
in the northwest flow aloft approaches the Carolina coast. This
will help push a slow moving cold front south into southern
South Carolina, propagating south of the Santee River by early
afternoon. Modified soundings ahead of the front show solid
mixed-layer instability (MLCAPE 1500-2000 J/kg with K-indices
pushing 40C) developing by late morning embedded within a weak
shear environment (0-6km bulk shear averaging ~15 kt). Moisture
is also abundant with surface dewpoints progged to hold in the
mid- upper 70s with PWATs nearing 2.50" at times (daily max for
KCHS for July 1 is just over 2.30" per SPC sounding
climatology).
Expect convection to develop near the Santee River in the
vicinity of the front by late morning, then slowly spread south
through the rest of southern South Carolina into Southeast
Georgia into the afternoon/evening hours in tandem with the
front. Given the degree of instability and moisture coupled with
surface moisture convergence values surpassing 50 g/kg/12hr at
times near the front and some forcing aloft with approaching
shortwave energy, the setup looks favorable of periods of
extremely heavy rainfall with hourly rainfall rates potentially
exceeding 3 in/hr. This is reinforced by the 30/12z HREF QPF
progs showing an ~90% chance for 3+ inches to fall in 3 hours
clustered in the Savannah-Charleston corridor. There are even
some signals that a few spots could see localized amounts in
excess of 6 inches (noted 12-hr probs of >5" averaging 70-75%
over central Charleston County, including Downtown Charleston).
Although antecedent conditions are fairly dry with D0 and D1
drought conditions in place, there is an increasing concern that
pockets of significant flash flooding could occur given the
intense hourly rainfall rates expected with the slow moving
convection, especially in urban areas such as Beaufort and both
the Charleston and Savannah Metro Areas. Complicating matters is
heavy rains could be falling at the afternoon high tide which
could enhanced the flood risk, especially in Downtown Charleston
and nearby communities. A Flood Watch has been issued from Noon
until 9 PM Monday for the South Carolina and Georgia coastal
counties, including Effingham, Hampton, Inland Colleton,
Dorchester and Inland Berkeley. Storm total QPF Monday into
Monday night will run 2-4" with localized amounts in excess of
6". Categorical pops 80-100% look reasonable, which is a bit
higher than the various 12z statistical guidance packages, but
closer to the 30/13z NBM. Highs will warm into the upper
80s/lower 90s, warmest across Southeast Georgia.
Convection will slowly wane through night, although elevated
pops will hold through daybreak Tuesday as the front moves south
and northeast onshore winds will keep moisture in place. This
will be especially true for coastal Georgia. Lows will range
from the upper 60s/lower 70s well inland to the near 80 along
the Georgia and far southern South Carolina beaches.
Tuesday and Wednesday: The front will slowly dissipate to the
south and offshore through the period as subtropical ridging
aloft builds back to the east. The pattern will return to more
typical summer time convective regime with onshore winds
supporting higher low- level moisture values across Southeast
Georgia. Scattered to numerous shower/tstms are expected each
afternoon and evening with activity diminishing during the
overnight hours. Highs will only warm to the mid-upper 80s
Tuesday with upper 80s/lower 90s for Wednesday. Lows Tuesday
night will range from the lower 70s well inland to the upper
70s/near 80 at the beaches.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
An impressive upper-level anticyclone will setup across the
Deep South and Southeast U.S. mid-late week. The risk for
showers/tstms will generally average below climatological
normals as a result. The heat will also steadily build with
highs reaching the upper 90s/near 900 inland Friday into the
weekend. Heat indices will push the 108 Heat Advisory criteria
during this time as well.
&&
.AVIATION /03Z MONDAY THROUGH FRIDAY/...
KCHS/KJZI/KSAV: Upstream convection associated with a short wave
and cold front will continue to approach the terminals during
the late evening and first part of the post-midnight period.
Recent guidance and trends suggest that this activity will fade
before getting to KCHS and KJZI. We`ll show VCTS from 04Z to 06Z
since there does remain various boundaries from convection to
form along. KSAV has a better chance of convection from 04Z to
07Z. We might need to include a period of TSRA with gusty winds
and flight restrictions if the upstream activity holds together.
The next chance for convection and prolonged flight restrictions
will occur Monday afternoon and evening as a cold front stalls
nearby. Considerable moisture, low level convergence, and
instability will favor several hours of at least MVFR weather
with moderate to heavy rains in SHRA and TSRA. Some potential
for IFR at times, and we can adjust in later TAF issuances if
necessary.
Extended Aviation Outlook: Brief flight restrictions are
possible in showers and thunderstorms, mainly in the afternoon
and evenings through the period.
&&
.MARINE...
Tonight: There remains a fairly tight gradient between an inland
cold front and Atlantic high pressure across Florida. This will
produce S and SW winds as high as 15 or even 20 kt, which in
turn allows for seas of at least 3 feet throughout. The inland
t-storms will weaken as they approach the coastal waters. But if
they hold together enough, a few of them could generate some
strong winds and lightning strikes on the waters south of
Edisto into the Georgia waters after 1 or 2 am.
Monday through Friday: A cold front will drop south through the
waters Monday with east/northwest winds prevailing all areas
Monday night. Widespread showers/tstms with heavy rain could
reduce vsbys to less than 1 NM at times and be accompanied by
gusty winds and cloud- to-ground lightning. There will be a bit
of a post-frontal surge Monday night into Tuesday with speeds
increasing to 15-20 kt over the South Santee to Edisto Beach
nearshore leg with 10-15 kt elsewhere. Northeast winds will
gradually veer more southerly for Thursday and Friday. Seas will
average 2-4 ft through the period, except up to 5 ft over
portions of the South Carolina nearshore waters in the northeast
flow behind the cold front.
&&
.CLIMATE...
Record High Minimum Temperature for June 30:
KCHS: 78F set in 1977. (Low so far today 79F)
Daily Rainfall Records for July 1:
KCHS: 2.66 set in 1948
KCXM: 1.64 set in 1966
KSAV: 2.76 set in 1871
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...Flood Watch from Monday afternoon through Monday evening for
GAZ101-116>119-137>141.
SC...Flood Watch from Monday afternoon through Monday evening for
SCZ042>045-047>052.
MARINE...None.
&&
$$
NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...
Area Forecast Discussion
National Weather Service El Paso Tx/Santa Teresa NM
543 PM MDT Sun Jun 30 2024
...New AVIATION...
.SYNOPSIS...
Issued at 100 PM MDT Sun Jun 30 2024
Daily thunderstorm chances will continue with Wednesday expected
to be the most active day. Temperatures will remain warm,
generally a few degrees above average.
&&
.DISCUSSION...
Issued at 100 PM MDT Sun Jun 30 2024
A subtle disturbance is approaching the CWA from the southwest.
WV satellite shows this ripple near the SW corner of Hudspeth Co.
at this typing. Vis is showing an increasingly agitated Cu field
with a few storms already noted on the radar. Current trajectory
has these moving into El Paso within the next 30-45 minutes, so
it`s time to complete this discussion to focus on near term
impacts. HRRR showing activity overspreading the entire CWA
between 21 and 22z as this subtle disturbance continues to lift
northward. Main threat today will be heavy rainfall and localized
flash flooding, especially if storms can train. Current dewpoints
are near 60 with PWAT values near 1.3" toward the International
Border with less than 1" for the northern part of the CWA. 850mb
moisture transport shows a northwestward transport, so I suspect
these values will increase for our northern areas. Damaging winds
will also be a concern this afternoon with DCAPE values over 1000
J/kg. HRRR showing activity decreasing after dark, but with
lingering showers or storms continuing well into the evening.
As we head into Monday and Tuesday, a little bit drier air pushes
into the region from the south, forcing the main moisture plume
toward AZ. Storm chances will be favored west but all locations
have at least a slight chance for thunderstorms each day. Highs
will warm with the drier air and re-alignment of the ridge axis
overhead. On Wednesday, a digging trough from the north will split
the ridge with a prominent center off the coast of CA and a larger
center covering much of the Deep South. This will allow the
subtropical plume to center over NM and Far W. TX. With the
expected alignment of the trough axis and richer moisture (GFS
showing 1.3-1.6" PWAT), Wednesday will be our best bet for storms
of the period.
Thursday onward, drier is set to push in from the northwest,
shifting storm chances to the south. Models continue to struggle
with how far south this moisture will be shoved. Additionally,
this pattern opens us up to disturbances aloft and frontal
intrusions. Both global models continue to show a frontal
intrusion on Saturday, which will enhance our rain/storm chances.
As it stands now though, there continues to be uncertainty with
rain / storm chances Thursday onward, and it will depend on which
factor wins out: dry air versus frontal boundaries and / or
disturbances aloft. Regardless, temperatures to finish out the
period look to be just above average, but NBM continues to show
5-7 degree spread between the 25th and 75th percentile for highs
at El Paso Thursday onward.
&&
.AVIATION...
(00Z TAFS)
Issued at 529 PM MDT Sun Jun 30 2024
Scattered showers and thunderstorms will continue accross the
area this evening through 06z. Previously, storms occurred at
KELP and KRUR but have diminished with some stabilization
occurring. More thunderstorms for KELP and KLUR are not expected
this evening but light showers may still occur. KTCS is undergoing
a thunderstorm with strong wind gusts. Additional thunderstorm
activity is expected. Focus of thunderstorm activity has shifted
west and will impact the area from KDMN to the AZ state line
through the evening. Lingering light showers will continue after
06z through 12z. Thunderstorm focus for tomorrow afternoon after
18z will be more to the west of a line from KDMN to KTCS. Areas to
the east will have much less convective activity.
&&
.FIRE WEATHER...
Issued at 100 PM MDT Sun Jun 30 2024
No significant fire concerns for the period. Monsoonal moisture
will remain in place for the period. Monday will feature slightly
drier conditions, which will limit thunderstorm coverage some as
well as allow min RH values to drop into the lower and middle 20s.
Tuesday will continue the drier trend as well as see an increase
in temperatures. Wednesday looks to be the most active day in
terms of thunderstorm coverage with an increase in moisture.
Starting Thursday, the forecast becomes a bit uncertain in terms
of moisture content and thunderstorm coverage. Winds, outside of
thunderstorm influences, looks light for the period. Venting will
generally range good to very good, decreasing to poor to good on
Wednesday.
&&
.PRELIMINARY POINT TEMPS/POPS...
El Paso 80 101 82 103 / 50 10 30 30
Sierra Blanca 69 94 72 96 / 30 10 20 30
Las Cruces 73 99 74 100 / 60 20 20 40
Alamogordo 70 96 71 97 / 40 20 20 30
Cloudcroft 52 74 54 75 / 50 40 30 60
Truth or Consequences 72 94 72 93 / 70 50 30 70
Silver City 65 88 66 89 / 80 70 40 80
Deming 72 98 72 98 / 80 40 30 60
Lordsburg 70 95 70 95 / 80 60 40 70
West El Paso Metro 77 99 79 100 / 60 20 30 30
Dell City 72 99 73 100 / 20 10 10 20
Fort Hancock 74 101 76 103 / 40 10 20 20
Loma Linda 70 93 72 94 / 50 20 20 30
Fabens 76 100 78 103 / 40 10 20 30
Santa Teresa 74 98 74 98 / 60 20 30 30
White Sands HQ 75 96 77 98 / 60 20 30 40
Jornada Range 70 96 70 97 / 70 30 30 40
Hatch 71 98 71 99 / 70 30 30 60
Columbus 73 98 74 98 / 70 30 40 40
Orogrande 72 96 73 97 / 50 20 20 40
Mayhill 58 85 59 86 / 40 40 20 60
Mescalero 57 85 59 86 / 40 40 30 60
Timberon 55 83 57 84 / 40 30 20 50
Winston 60 84 60 83 / 70 80 40 90
Hillsboro 68 92 69 91 / 80 60 40 80
Spaceport 67 95 67 95 / 60 40 30 60
Lake Roberts 62 87 62 87 / 80 70 40 90
Hurley 65 91 66 92 / 80 60 30 70
Cliff 65 97 66 97 / 80 60 30 70
Mule Creek 66 90 68 90 / 80 70 40 70
Faywood 67 90 68 91 / 80 50 40 70
Animas 69 95 69 95 / 70 60 30 60
Hachita 68 95 69 95 / 70 50 40 60
Antelope Wells 68 95 69 95 / 70 50 50 70
Cloverdale 66 90 67 90 / 60 60 40 70
&&
.EPZ WATCHES/WARNINGS/ADVISORIES...
TX...None.
NM...None.
&&
$$
FORECASTER...04-Lundeen
Area Forecast Discussion
National Weather Service Grand Junction CO
557 PM MDT Sun Jun 30 2024
.KEY MESSAGES...
- A Flood Watch for southeast Utah and southwest Colorado
remains in effect through Monday afternoon. Abundant monsoonal
moisture will bring a heavy rainfall rate threat to these
areas through tomorrow.
- The stonger thunderstorms will be capable of producing gusty
outflow winds, large hail, and plenty of cloud-to-ground
lightning.
- Monsoonal moisture gets forced east on Tuesday, and afternoon
showers will be far more isolated in nature.
&&
.SHORT TERM /THROUGH MONDAY/...
Issued at 119 PM MDT Sun Jun 30 2024
Another day, another round of storms. It took awhile for
convection to get going today thanks to a fairly strong cap.
The morning sounding showed a strong midlevel inversion from 400
to 500mb so it took some time to break through. Once it did,
convection started going which is exactly what happened. In 2
scans (approximately 8 minutes), radar returns of 20dBZ jumped
to 58dBZ...not too shabby. PWATs remain high and there`s little
change in that regard. Flow around a high situated over Texas
continues to pump in moisture from the south. PWATs hitting 250
to 300% of normal is still in the forecast with models showing
this being 2 to nearly 4 standard deviations above normal. The
deepest moisture is still expected to remain over the southern
half of the forecast area so the Flood Watch will remain in
place. CAPE values as per SPC`s Mesoscale Analysis are forecast
to reach between 1500 to 2000 J/kg from 4PM onwards. The highest
CAPE values currently remain over the San Juans. The stronger
storms will produce some gusty outflow winds, large hail, and
torrential rains that will increase flooding concerns. The 18Z
HRRR guidance is keeping convection in the forecast through this
afternoon and evening and continuing for the overnight. Looks
like a second wave will move through around 9PM and though convection
will die down, some, lightning, gusty winds, and the continued
threat of heavy rain will continue.
Monday morning, some lingering, moderate to occasionally heavy,
showers will be found across the higher terrain of the southern
portion of the CWA. By noon, another round of showers and storms
begins...rinse and repeat. One would think the residual clouds
would inhibit convection but forecast CAPE for tomorrow varies
from 500 to 1500 J/kg while midlevel lapse rates will reach 7 to
9C/km. Yep, there`s plenty of instability that will get worked
on as an upper level trough moves through. Furthermore, a weak
jet streak will also be moving overhead bringing some upper
level divergence that will also aid in lift. All that being
said, look for very similar conditions tomorrow as we`ll see
today.
&&
.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
Issued at 119 PM MDT Sun Jun 30 2024
The upper level trough exits the region on Tuesday with dry
northwesterly flow in its wake. This will serve to shunt
monsoonal moisture south and eastward, effectively turning down
the tap we`ve been drinking from the last week. This will spell
out dry conditions over the western half of the CWA, but remnant
moisture hanging on along the terrain will likely get worked on
another day Tuesday for some afternoon showers and
thunderstorms. Temperatures will remain on the mild side behind
this pseudo- frontal passage Tuesday, with only our desert
valleys hitting 90`s. Temperatures quickly surge back upward
Wednesday, as the passing wave flattens into a zonal regime
thanks to a strong northwesterly jet digging into the PACNW.
This will find us in a bit of an ambivalent flow pattern with a
southwest lean to it. Desert valleys will again flirt with
triple digits, both Wednesday and Thursday. The broad cyclonic
flow to our north finally exits Thursday afternoon and northwest
flow returns another downturn in temperatures as well as more
dry air. The drying trend from Wednesday onward proposes some
uncertainty into precipitation forecasts. While shower and storm
coverage will be notably less, it remains risky to commit to a
dry forecast. For now, we`ll stick with isolated showers on the
terrain through the end of the week. The dry surface conditions
in the northwesterly regime should allow for some gusty outflow
winds under collapsing storms. This drying trend continues
through the weekend thanks to an amplifying ridge over the West.
The return of warm, dry conditions will once again turn our
attention back to fire weather late week as well. Wednesday and
Thursday look like the best bets for winds and relative
humidities to coincide for critical fire weather. While RH
values will be there, winds still look pretty marginal. The
arrival of the Fourth of July holiday and return of a dry
pattern after a very wet period will warrant some vigilance.
&&
.AVIATION /00Z TAFS THROUGH 00Z TUESDAY/...
Issued at 540 PM MDT Sun Jun 30 2024
Widespread showers and storms continue this afternoon and will
continue through the evening and overnight hours. Included VCSH,
VCTS and -TSRA for all TAF sites except for KVEL and KCNY
through tomorrow morning. Flight conditions will remain mostly
VFR north of I-70 with better chances for lower flight
condition south of I-70. Heavy rain, small hail, and gusty
winds remain the concern due to the convection. Some areas of
MVFR, possibly IFR, can`t be ruled out especially overnight due
to low ceilings and stratiform rain. These similar conditions
are likely as well tomorrow.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...Flood Watch through Monday afternoon for COZ009-011-012-014-
017>023.
UT...Flood Watch through Monday afternoon for UTZ022-028-029.
&&
$$
SHORT TERM...TGR
LONG TERM...LTB
AVIATION...TGJT
Area Forecast Discussion
National Weather Service Goodland KS
529 PM MDT Sun Jun 30 2024
.KEY MESSAGES...
- Much cooler highs today due to cloud cover most of the day.
- Hot weather returns Monday behind a warm front with highs
returning to the low 100s east of the Colorado border.
- Chances for storms each day, mainly during the evening.
&&
.SHORT TERM /THROUGH TUESDAY NIGHT/...
Issued at 255 PM MDT Sun Jun 30 2024
Across the region this afternoon, skies are a wide mix of sunny to
cloudy as many locales still seeing lingering low cloud cover from
this morning. Temperatures as of 200 PM MDT are ranging mainly in
the lower and mid 60s east where clouds are most prevalent, to the
upper 60s and into the 70s where sunshine has finally broke through
due to dissipating clouds. With a front to the west and high
pressure east, winds remain southerly with a tight gradient in the
west closest to the front and associated low, with gusts still 25-35
mph at times.
Main weather concerns in the short term period will focus on the
return of hot conditions, mainly Monday, along with the chances for
strong to severe storms later today and again on Monday and Tuesday.
For this afternoon into the evening hours, the front to the west
will be the focus of trw initiation via the latest CAMs (HRRR, RAP
and NamNest). There are some timing differences between the 3 models
but overall around the 23z-01z timeframe will start west pushing
east ahead of the front through 06z Monday before tapering off. SPC
has a Marginal Risk for storms in place for this afternoon and
tonight along/west of Highway 27. Model soundings do show
instability over the first few hours of starting, will taper in time
as activity shifts east. Some locales could see some locally heavy
rainfall this evening per WPC`s latest Day 1 Outlook for Excessive
Rainfall.
Going into Monday, the aforementioned front will lift into the
northern CWA with some lingering precip during the morning. The next
chance for storms will occur around midday as convection initiates
along the front. Hot conditions in the warm sector has prompted a
Heat Advisory for eastern locales, with areas west seeing conditions
variable due to the timing/positioning of cloud cover along the
front. Heat indices for zones along/east of Highway 83 up to the 103-
105, that may be extended later as the cloud cover along the
boundary may slow its advance increasing temps further west.
Along and north of the front, SPC has a Marginal to Slight risk area
for severe storms with mainly hail/wind threat. While a low chance
for any potential tornadoes due to less shear, can`t rule out a land
spout potential for any storms along the front. CAMs shift all
activity east of the CWA by 06z-12z Tuesday.
On Tuesday, the aforementioned front/low will shift south of the
area creating best chances for storms south of the Interstate. Ample
low level moisture will create better storm chances (30-50%) for the
area as easterly flow will aid in storm production. Best instability
will lie along the front to the south, and SPC has a Marginal Risk
area in place for locales along/south of I-40. A slow wavering of
rain/storms moves east along the boundary Tuesday night, tapering
going into Wednesday.
For temps, daytime highs on Monday will range in the mid 90s
west/northwest through the lower 100s east of a line from McCook,
Nebraska southwest to Goodland, Kansas and south to Tribune, Kansas.
Cooler on Tuesday with mid 80s to lower 90s expected.
With the hot temperatures on Monday expected, areas east of a front
and associated increasing cloud cover in the northwest portion of
the CWA, will see heat indices increase into the lower and even mid
100s. The area of focus at this time is most locales along/east of
highway 83 where a Heat Advisory is now in effect.
Overnight lows tonight will range in the lower to mid 60s, giving
way to a wide range Monday night from the upper 50 to mid 60s west
into the upper 60s to lower 70s east. By Tuesday night, mid 50s west
to the mid 60s east are expected.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
Issued at 207 PM MDT Sun Jun 30 2024
The latest runs of the GFS and ECMWF, show the upper ridge over the
southern portion of the country shifting more eastward and southward
as the week progresses. The arrival of a decent closed low at 500mb
that swings through the northern Plains will keep the flow aloft
mainly zonal. There will be a few weak shortwaves that interact with
weak cold fronts at the surface, that will trigger low chances for
storms potential. Overall a (20-40%) chance on Wednesday, will trend
to (30-40%) Thursday night with some lingering convection Friday
morning (20%). Next chances (20%) will occur over the evening hours
next weekend as a low tracks south over eastern Colorado. The main
concerns other than the low storm chances will be the return to near
to above normal temperatures for much of the extended.
For temps, daytime highs for the extended period will range in the
upper 80s midweek. On Thursday, mid 80s to the lower 90s are
expected, then trending lower on Friday to the lower to mid 80s.
Going into the upcoming weekend, upper 80s to lower 90s on Saturday
give way to lower to mid 90s next Sunday.
Overnight lows will range from the mid 50s west to the lower 60s
east Wednesday through Friday, then for the weekend, upper 50s to
mid 60s are expected.
&&
.AVIATION /00Z TAFS THROUGH 00Z TUESDAY/...
Issued at 525 PM MDT Sun Jun 30 2024
Low ceilings, and potentially heavy rain, are expected to impact
flight categories at KMCK and KGLD throughout the period,
including down to LIFR. Storms and showers will be moving in
from the west and are expected to impact KGLD around 2Z with any
heavier stuff moving out around 5Z. KMCK`s prime time for
stronger storms look to be between 4-9Z. Strong gusts up around
50 kts could be possible with storms and the outflows they
produce. Light showers and sprinkles are possible throughout the
remainder of the period. For KGLD IFR look to linger until an
hour or two after sunrise, KMCK may get out of IFR ceilings
around 18Z, it depends on how quickly dry winds move into the
area. Near the end of the period, a cold front looks to move in
a bring more storms with it. Some guidance is suggesting patchy
fog around 6Z tonight, but confidence is low this will occur
with any ongoing convection.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...Heat Advisory from 1 PM to 8 PM CDT Monday for KSZ003-004-015-
016.
CO...None.
NE...Heat Advisory from 1 PM to 8 PM CDT Monday for NEZ081.
&&
$$
SHORT TERM...JN
LONG TERM...JN
AVIATION...CA
Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
850 PM CDT Sun Jun 30 2024
.KEY MESSAGES...
- Dangerous swimming conditions at area beaches through tonight
due to breezy onshore winds and high waves.
- Return to more typical summer temperatures and humidity
Tuesday onward with periods of showers and thunderstorms at
times too.
&&
.UPDATE...
Issued at 849 PM CDT Sun Jun 30 2024
No significant changes to going forecast tonight into Monday.
Sprawling, 1026 mb surface high pressure was centered over far
northern WI/upper MI this evening, and will continue to build
slowly southeast across Lake Michigan by morning and then into
the central Great Lakes region through the day Monday. Breezy
north-northeast flow along the southeastern periphery of the
high will linger across the area (especially over Lake Michigan
and into parts of the metro and northwest Indiana) through the
evening, before gradually diminishing overnight as the high
approaches. Clear skies, light winds and a cooler/drier air mass
will support overnight low temperatures around 50 (some upper
40s possible in the coolest spots) away from the core of the
Chicago metro, with upper 50s downtown and along the immediate
lake shore.
With the surface high off to the east of the area on Monday,
modest winds will turn east-southeasterly, with lake cooling
limiting temps to the lower 70s along the IL shore, while
warming into the mid-70s elsewhere. Mostly sunny skies are
expected, with only some increasing thin cirrus later in the
day.
Ratzer
&&
.DISCUSSION...
Issued at 300 PM CDT Sun Jun 30 2024
Through Monday Night:
Early this afternoon, a fair weather cumulus deck overhangs the CWA,
but drier air being fed into region is slowly eroding the cloud
cover. Cold advection driven by a prominent region of high pressure
centered up in Minnesota has kept temperatures in the middle 60s to
near 70 degrees, cooler than what you would typically expect on the
last day of June. Meanwhile, breezy northerly winds over the lake
since last evening have been consistently churning waves in the 5
to 7 foot range with several peak waves reported at just under 10
feet. Gusts are gradually waning this afternoon and that, for the
most part, should continue through this evening and overnight, and
waves will respond accordingly. However, several pieces of high res
guidance are resolving one final surge of wind, especially along the
far southern lakeshore, during the mid to late evening. Most models
suggest more 20 to 25 kt gusts are in store, although the HRRR has
been saying over numerous runs now that a period of near 30 kt
gusts could be on the table along the Indiana lakeshore. That
said, decided to extend the ongoing beach hazards statement and
small craft advisory through 12Z Monday across all zones.
The aforementioned high will propagate southeastward across the
Great Lakes region tonight and tomorrow. This will keep conditions
nice and quiet during the day and the milder return flow will bump
afternoon temperatures into the middle and upper 70s. Meanwhile, the
large upper high in the Plains responsible for the fair weather will
get shunted to the east Monday night by a digging trough. The
surface response will be a center of low pressure working across the
Plains during the night. The more appreciable rain chances arrive
during the day on Tuesday as the storm system approaches, but a
developing warm frontal boundary could extend eastward from the
storm and bring a few showers to our far northwestern CWA before
daybreak. The brunt of the storm is covered in the long term
discussion below.
Doom
Tuesday through Sunday:
Following a quiet and seasonably cool start to the week on Monday,
an active belt of west-southwesterly upper level flow is expected
to set up across much of the Midwest into the western Great Lakes
downstream of aggregate upper troughing settling over the
northern Plains. Accordingly, conditions will become supportive
for a few episodes of showers and thunderstorms through the to
later portion of the period as a warm and humid airmass works
back northward across the region.
The first period of showers and thunderstorms is expected to set
up mainly to our west-northwest across the upper Midwest Monday
night in response to a corridor of enhanced theta-e advection
along a strengthening southwesterly low-level jet axis (45-50 kt).
This activity is expected to track east-northeastward into WI and
perhaps as far south as parts of far northern IL (north of I-88)
late Monday night into Tuesday morning. Since most of this
activity is likely to outpace the instability axis, much of this
convective activity should be in a weakening state by early
Tuesday morning. Nevertheless, we continue to carry some chance
POPs into Tuesday morning, highest along the WI state line.
Following any lingering morning showers it appears much, if not
all of the afternoon may be precipitation free across the area as
the really humid and unstable axis remains to our west in closer
proximately to an approaching cold front. However, temperatures
will be on an uptick during the day on breezy southerly winds.
Accordingly, readings are likely to top out in the low to mid 80s
on Tuesday.
Afternoon convection is expected to develop to our west Tuesday
as the prefrontal airmass destabilizes in the vicinity of the
aforementioned approaching cold front. This front, as well as any
associated thunderstorms, will then shift eastward into our area
into Tuesday night. This is certainly not a favorable diurnal
timing for robust convection in our area. However, given
respectable deep layer bulk shear and a stout low level jet, it`s
possible scattered thunderstorms could persist well into the night
despite the stronger synoptic forcing remaining well north the
area. Nevertheless, it appears the higher threat area for any
strong to severe storms will largely remain west of the area on
Tuesday. Following the cold frontal passage late Tuesday night,
the front is expected to lay out in a west-east orientation
somewhere across central parts of IL and IN on Wednesday. If it
ends up setting far enough south, we could end up with a primarily
dry day Wednesday, albeit a very warm one, with highs well into
the 80s.
Heading into the July 4th holiday on Thursday, the front is
forecast to gradually lift back northward as a warm front
Wednesday night into the day on Thursday. Depending on how far
north the front gets will determine the extent of shower and storm
coverage during the Thursday into Friday timeframe as another
shortwave trough pivots into the Great Lakes. At this point,
guidance is favoring an afternoon and evening show for our area on
Thursday with the greatest coverage in our southern CWA. However,
this general timing is still low confidence given that we are
still several days out and existing storms on Wednesday will play
a role in frontal placement. Therefore, those with outdoor plans
for the 4th should keep an eye on this period.
Regardless of how Thursday plays out, it does appear that
another front should push through on Friday and finally bring
the periods of showers and storms to a close heading into next
weekend. Though the typical late June early July heat and
humidity is forecast to remain through the period with highs in
the mid to upper 80s and dew points in the 60s to around 70 each
day.
KJB/Yack
&&
.AVIATION /00Z TAFS THROUGH 06Z MONDAY/...
Issued at 611 PM CDT Sun Jun 30 2024
- Breezy NNE winds diminish through late evening.
- East winds Monday, becoming southeast Monday evening.
Fine VFR flying conditions will persist through the TAF period.
Diurnal cu will fade with sunset, with clear skies overnight and
then some gradually increasing high cirrus Monday afternoon into
Monday night
Surface high pressure over the northern Great Lakes will drift
southeast across Lake Michigan overnight and to the central
Lakes by Monday evening. Breezy north-northeast winds will
linger this evening, especially across the metro terminals and
particularly at KGYY right along the lake, but will diminish
late evening and overnight. With the high off to the east on
Monday, winds will start out easterly as we mix out in the
morning, turning east-southeast and eventually southeast in the
afternoon inland. Winds will remain more easterly into early
evening at KORD/KMDW however due to the lake breeze. Winds will
turn light southeast later Monday evening for KORD/KMDW.
Ratzer
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...Beach Hazards Statement until 7 AM CDT Monday for ILZ006-
ILZ103-ILZ104.
IN...Beach Hazards Statement until 7 AM CDT Monday for INZ001-
INZ002.
LM...Small Craft Advisory until 7 AM CDT Monday for the IL and IN
nearshore waters.
&&
$$
Visit us at weather.gov/chicago
Area Forecast Discussion
National Weather Service Shreveport LA
1047 PM CDT Sun Jun 30 2024
...New UPDATE...
.UPDATE...
Issued at 1041 PM CDT Sun Jun 30 2024
Decided to make a few changes to POPS and overnight lows based on
current trends and short-term progs. Also, added some fog to
our SE Oklahoma, SW/South-Central Arkansas zones, and portions of
NE Louisiana overnight. In addition to this, decided to let the
Excessive Heat Warning expire, but replace most of it with a Heat
Advisory, and kept a Heat Advisory in place for all of our East
Texas zones. For the remainder of the night, expect precip to
continue to diminish, with overnight lows generally in the mid to
upper 70s.
&&
.SHORT TERM...
(This evening through Monday Night)
Issued at 246 PM CDT Sun Jun 30 2024
Nice little clusters of showers and thunderstorms are going from
SE OK across S AR and just edging into N LA now. We see spotty
convection farther south. All this activity is trying to
establish a little cool pool north, but lots of holes in that
cheese so far. The HRRR does a decent job of representing the
areas of concern and drifting southward into the evening as well.
This rain should make for a slightly cooler day tomorrow with heat
index 105 or less for at least S AR. Elsewhere, heat calculations
will generally be in the 106 to 110 range with another heat
advisory for Monday. We may see another warning upgrade if we end
up with some compressional heating tomorrow, but for now
considering current warning, we are sticking with another heat
advisory for Monday for our counties in OK/TX and all our LA
parishes, excluding S AR to some extent. Barring some decent
rainfall, it will be another night with some near record warmth
for lows at most locales, but some rain cooled areas will be
possible. Highs will be in the middle 90 range for most under
added clouds and the humidity will still running soupy, boosting
those HI numbers. The chance for more convection continues along
and south of I-20 for the most part on Monday and then dries up
going forward for a while. Lows tomorrow night should see the
benefit of the weak front with a little cooler range for lows in
the low to mid 70s on Tuesday as the 1027mb core stays in the
Great Lakes. /24/
&&
.LONG TERM...
(Tuesday through next Saturday)
Issued at 246 PM CDT Sun Jun 30 2024
Much like this last little air mass, we are grazed by the
northeast winds briefly and see just one day and one night of
slightly cooler temps. Mid to late week will continue with mid to
upper 90s and lows in the mid to upper 70s widespread once again.
The sea breeze will spread into the parishes under the building
upper high and not much else during midweek. The models are
trending closer to average for next weekend as a deeper and
stronger upper low edges another front down into our neck of the
woods. So model pops are in the 20-40 range again by the end of
the forecast period keeping back the triple digits perhaps. /24/
&&
.AVIATION...
(00Z TAFS)
Issued at 618 PM CDT Sun Jun 30 2024
Conditions forecast to improve across area terminals through this
evening and convection gradually dissipates. Stable conditions
expected overnight with VFR conditions mainly prevailing with
light and variable winds. Could see MVFR ceilings just after
daybreak across MLU/ELD/TXK, which are expected to improve to VFR
by 01/15Z. Otherwise, VCTS conditions possible across most
locations except TYR/ELD after 01/18Z. /05/
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 80 96 77 100 / 20 40 0 10
MLU 77 94 72 97 / 20 20 0 10
DEQ 75 93 72 96 / 20 20 0 0
TXK 76 93 73 100 / 20 30 0 0
ELD 74 93 69 97 / 20 20 0 0
TYR 80 97 78 100 / 10 20 0 0
GGG 79 96 77 99 / 10 30 0 10
LFK 78 97 77 98 / 10 40 0 10
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...Heat Advisory until 8 PM CDT Tuesday for ARZ059-070.
LA...Heat Advisory until 8 PM CDT Tuesday for LAZ001>006-010>014-
017>022.
OK...Heat Advisory until 8 PM CDT Tuesday for OKZ077.
TX...Heat Advisory until 8 PM CDT Tuesday for TXZ096-097-108>112-
124>126-136>138-149>153-165>167.
&&
$$
SHORT TERM...24
LONG TERM....24
AVIATION...05
Area Forecast Discussion
National Weather Service Tallahassee FL
907 PM EDT Sun Jun 30 2024
...New UPDATE, MARINE...
.UPDATE...
Issued at 859 PM EDT Sun Jun 30 2024
Similar to yesterday evening`s forecast update overnight rain
chances were adjusted to account for the latest radar trends and
HRRR run. Clusters of scattered thunderstorms are ongoing across
the region and have been accompanied by heavy rain rates and
frequent lightning. Storm motions have been gradually from north
to south, though erratic outflow boundaries and chaotic collisions
have caused some random movement at times.
The airmass remains very moist and unstable despite the loss of
daytime heating. Instances of localized flooding are possible,
particularly around I-75/Valdosta area where merged cells have
gotten hung up a bit. There is also the potential for strong/gusty
winds. We still expect a steady diminishing trend the next few
hrs with lingering convection over Apalachee Bay.
&&
.NEAR TERM...
(Through Monday)
Issued at 252 PM EDT Sun Jun 30 2024
Ample moisture remains in place across the region as indicated by
precipitable water values (PWATs) of 2.2" to 2.5", or above the 90th
percentile for late June/early July. Throw in a weak
shortwave/inverted trough moving across Florida and an approaching
cold front and there is the potential for quite a bit of rain in
short amount of time this afternoon and again on Monday. Ensemble
guidance is indicating a 30% chance or higher of experiencing 3"+
much of the Florida Big Bend and parts of southern Georgia. There
are also non-zero chances of experiencing 5"+ and 8"+, primarily
across the southeastern Florida Big Bend, on the HREF. This means
there is the potential for localized areas of flash flooding over
the next 36 hours or so. As a result, a Flood Watch was issued
starting this afternoon and lingering until at least Monday night
for areas east of the Apalachicola River in Florida and portions of
southwestern Georgia. It is worth noting that there is expected to
be a lull in activity tonight as we lose the heating of the day
before showers and thunderstorms blossom with the daytime heating
Monday.
Another thing worth mentioning is that fog is also possible tonight
into early tomorrow morning for areas that experience the heaviest
rain later this afternoon into the evening. However, confidence was
not high enough in any one location to include in the official
forecast at this time.
As far as temperatures go, we`ll be near to slightly above normal
outside of any showers and thunderstorms with highs reaching into
the lower to middle 90s. Overnight lows will drop into the middle
70s. With rain coverage anticipated to be pretty high, have opted
against issuing a Heat Advisory at this time. However, if we end up
being drier than expected, heat indices could approach the 108
degree threshold. Something to monitor tomorrow.
&&
.SHORT TERM...
(Monday night through Tuesday night)
Issued at 252 PM EDT Sun Jun 30 2024
A stalled front is expected to remain draped over the area from west
to east through the short term period. This feature may provide a
focus for widespread showers and thunderstorms throughout the day on
Tuesday, with gusty winds and locally heavy rainfall the primary
threats. Depending on how much rainfall we receive today and Monday,
any saturated areas would be more susceptible to flooding from
additional rainfall on Tuesday. Due to a combination of increased
rain chances, the front, and cloud cover, highs are only forecast in
the upper 80s to low 90s. Lows generally remain in the mid 70s.
&&
.LONG TERM...
(Wednesday through Saturday)
Issued at 252 PM EDT Sun Jun 30 2024
A transition to a hotter and drier pattern is expected for the long
term as ridging builds back in overhead. Rain chances will gradually
diminish Wednesday into Thursday, with only isolated to scattered
coverage of showers and storms expected by the end of the week and
weekend. Along with the ridge, high temperatures will once again
soar into the mid to upper 90s and may even approach 100 in a few
areas. Lows overnight will not provide much relief, remaining in
the mid to upper 70s.
&&
.AVIATION...
(00Z TAFS)
Issued at 701 PM EDT Sun Jun 30 2024
Scattered showers and thunderstorms potentially affecting all
terminals will continue through the evening. Light to calm winds
can be expected during the overnight hours, and the potential for
patchy fog may develop around the TLH, ABY, and VLD terminals.
Showers and thunderstorms pick up yet again tomorrow, with some
storms possibly strong with gusty winds and frequent lightning.
Heavy rain could bring down vsbys at some sites. Winds will be
northerly during the morning hours, then vary during the rest of
the TAF period due to scattered thunderstorms.
&&
.MARINE...
Issued at 859 PM EDT Sun Jun 30 2024
Offshore buoys were reporting westerly winds between 10 and 15 kts
with 2-3-ft seas and a dominant period of 7-8 seconds this
evening.
From CWF Synopsis...Overnight maritime convection aims to focus
over Apalachee Bay. Southwesterly flow around 10 knots and seas
around 3 to 4 feet will prevail until a weak frontal boundary
pushes into the Gulf late Monday and winds become light and
variable in its wake. Scattered showers and storms are expected
through the weekend and early next week with activity generally
greatest in the overnight and early morning hours as the diurnal
land breeze circulation is at its peak.
&&
.FIRE WEATHER...
Issued at 252 PM EDT Sun Jun 30 2024
No fire weather concerns are expected the next few days as
dispersions are expected to be fair to good across the region.
Scattered to numerous showers and thunderstorms are possible the
next few days. Gusty and erratic winds and heavy downpours are
possible within any of the storms. Otherwise, temperatures will
climb into the middle 90s with heat indices pushing 105 to 108 the
next couple of days.
&&
.HYDROLOGY...
Issued at 252 PM EDT Sun Jun 30 2024
A Flood Watch was issued for the Florida Big Bend and portions of
southwest Georgia for later this afternoon into Monday evening.
Widespread rainfall amounts of 1" to 3" are possible the next couple
of days, so widespread flooding or river flooding is not expected.
However, abundant moisture combined with an inverted trough and a
cold front nearing the region means there is the potential for a few
localized areas of 3"+ of rain in a short amount of time, similar to
what we experienced in Gadsden/Leon and Houston Counties Saturday
evening. Recent HREF and ECAM guidance shows non-zero probabilities
of 5"+ over the next 24 to 36 hours. This will likely lead to
localized flash flooding, especially in poor drainage and urban
environments due to extremely efficient rain processes and high
rainfall rates expected. It`s also worth noting that there will be a
lull in the activity tonight into early tomorrow with additional
showers and storms expected later Monday morning that will last
through Monday afternoon and into the evening.
Additional afternoon showers and storms are possible each afternoon
leading up to the 4th of July and may bring the chance of very
localized nuisance flooding underneath any of the stronger storms.
No river flooding is anticipated for the next several days.
&&
.SPOTTER INFORMATION STATEMENT...
Spotter activation is not requested. However, spotters are always
encouraged to safely report significant weather conditions when they
occur by calling the office or tweeting us @NWSTallahassee.
&&
.PRELIMINARY POINT TEMPS/POPS...
Tallahassee 77 92 76 91 / 80 70 40 70
Panama City 78 90 78 89 / 90 70 30 50
Dothan 76 95 74 90 / 80 50 30 60
Albany 75 94 74 88 / 60 60 50 60
Valdosta 75 93 74 91 / 90 70 50 70
Cross City 75 91 75 92 / 60 70 40 70
Apalachicola 79 89 79 88 / 60 70 30 50
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
FL...Flood Watch through Monday evening for FLZ015>019-026>029-034-
115-118-127-128-134.
High Rip Current Risk through late Tuesday night for FLZ108-112-
114-115.
GA...Flood Watch through Monday evening for GAZ143>148-155>161.
AL...None.
GM...None.
&&
$$
UPDATE...IG3
NEAR TERM...Reese
SHORT TERM...Merrifield
LONG TERM....Merrifield
AVIATION...Montgomery
MARINE...Merrifield/IG3
FIRE WEATHER...Reese
HYDROLOGY...Reese
Area Forecast Discussion
National Weather Service Tucson AZ
831 PM MST Sun Jun 30 2024
.UPDATE...
As convection has ended across southeastern Arizona and the gust
front from earlier convection has pushed into Maricopa county, the
Blowing Dust Advisory and Flood Watch have both been cancelled.
&&
.PREV DISCUSSION... /issued 121 PM MST Sun Jun 30 2024/
.SYNOPSIS...Active monsoon pattern for the next 7 days will bring
daily chance of showers and thunderstorms. Some storms will
generate strong winds and locally heavy rainfall.
&&
.DISCUSSION...Latest visible satellite imagery this afternoon is
showing an MCV near Rocky Point with generally partly to mostly
cloudy skies across much of southeast Arizona. The clouds held
on a bit more than expected through the midday hours so that has
certainly slowed the warming and destabilization process. Where
skies have cleared out for sufficient time, we`re seeing
thunderstorms from in the last hour across portions of
Graham/Greenlee/Cochise Counties. Another mid level disturbance is
quickly approaching from the east-southeast and that will help aid
in deeper layer lift this afternoon into the evening hours. MLCAPE
values will increase to around 1000-1500 J/KG as CIN diminishes over
the next hour or two. This will be enough to result in convective
development and the latest HRRR and UofA WRF model runs are in
agreement on this. Given the anomalously high moisture levels, flash
flooding will be a concern along with strong and gusty outflow winds
as DCAPE values range from about 800-1200 J/KG across our forecast
area. These gusty outflow winds may produce a large area of blowing
dust to the NW of Tucson. A Blowing Dust Advisory is in place for
this and any short fuse intense dust storms will be covered with
Dust Storm Warnings if needed. Convective activity may persist well
into the evening hours, especially from Tucson westward.
Abundant moisture remains in place for Monday, though just how much
activity we see will partially be dependent on what takes place
today/tonight. The flow does become a bit more southwesterly on
Monday. The moisture will remain with us through about Wednesday
with PWAT values ranging from about 1.4 inches to 1.7 inches across
the forecast area to keep the active period ongoing. Thereafter,
the ensembles are showing the mid/upper high reconsolidating to our
north/northwest. This will change the flow to become more
northeasterly. However, some drier air will also start filtering in
from the north and keep the best chances for daily showers and
thunderstorms from Tucson south and eastward.
&&
.AVIATION...Valid through 02/00Z.
SCT-BKN clouds at 8-12k ft AGL thru the fcst period. Scattered-
numerous SHRA/TSRA 30/20Z-01-04Z, then becoming isolated -SHRA/-TSRA
overnight. Another round of SCT -SHRA/-TSRA aft 01/18Z thru the end
of the fcst period. Expect brief MVFR conds nr storms. SFC winds 10
kts or less with the occasional afternoon gusts, except stronger due
to gusty outflows from storms. Aviation discussion not updated for
TAF amendments.
&&
.FIRE WEATHER...Relatively deep moisture will stick around through
the forecast period. Scattered ton numerous showers and
thunderstorms this afternoon and tonight. The upcoming week will see
daily chances of afternoon and evening showers and thunderstorms.
Strong and erratic gusty winds of 40 mph or higher can be expected
with any storm development, along with locally brief heavy
rainfall. Outside of thunderstorm winds, 20-foot winds will
generally be 15 mph or less each afternoon with the occasional gust
of 20 mph. Min RHs will generally be around 20% in the valleys and
30s in the mountains with good overnight recoveries.
&&
&&
.TWC WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
Update...Edwards
Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson
Area Forecast Discussion
National Weather Service Las Vegas NV
811 PM PDT Sun Jun 30 2024
.SYNOPSIS...Hot and breezy conditions will continue across most
of the region today. Monsoonal moisture will move back into
northwest Arizona today, bringing slight chances for thunderstorms
in eastern Mohave County through the middle of the upcoming week. A
strong ridge of high pressure will build Wednesday through the
Independence Day weekend, with temperatures climbing to dangerous
levels for several days.
&&
.UPDATE...Winds continue to decrease this evening as the sun sets,
thus the Red Flag Warning for Lincoln County has been allowed to
expire at 8 PM. With today`s high and low temperatures pretty much
locked in at this point, we can do a little number crunching to get
June`s numbers for our climate sites. Long story short, it was a hot
one. All 7 climate sites recorded a top-5 warmest June, with Las
Vegas shattering its June records. Coming back to the forecast,
we`ll be monitoring the potential for some showers/storms creeping
into southern Mohave County tonight. Should convection reach this
area, the main concerns would be isolated heavy downpours, but the
chance of flash flooding is less than 10%. Rain chances through mid-
week will be confined to Mohave County as the edge of monsoonal
moisture noses in. Otherwise, our forecast area remains dry and hot,
with temperatures running 3-6 degrees above normal. During the 2nd
half of the week, heat becomes more excessive as high pressure
builds. Many locations will likely be flirting with daily records,
and it`s possible a few all-time highs could be challenged. Stay
cool out there.
&&
.SHORT TERM...tonight and Through Tuesday Night.
Will need to watch the moisture pool that is situated over the
Sonoran Desert this afternoon and how it may influence the weather
in southern Mohave County tonight. The latest HREF and hi-res models
do develop showers and thunderstorms that might rotate into
southeast portions of Mohave County tonight. This is when HREF shows
30%-40% probabilities for SB CAPE over 500J/kg and a brief increase
of PWATs to 1.0-1.5 inches. The probability for dewpoints over 60F
also increases to 80%-90% this evening and tonight in areas south of
I-40 in Mohave County. Based on this change in the atmosphere since
the previous forecast and ensemble trends, ensured there was a
mention of precipitation tonight through the area. Focused on the
far southeast corner of Mohave County, will monitor trends and model
output to see if precipitation chances need to be brought further
west tonight. Even with all this, chances will be low (30% or less)
and impacts would be limited. Lightning is noted on HRRR models
tonight and with some midlevel instability seen on model soundings
in the area, lightning will be the main threat. Gusty outflow winds
and brief heavy rain will also be possible. Will need to watch for a
potential outflow winds pushing in from convection that develops
further south. A few hi-res wind models do show a south to southeast
outflow moving through southern Mohave County this evening and
tonight, but no impactful winds were noted.
Across the rest of the region, it will remain dry. Breezy winds this
evening will subside tonight but should pick up again Monday
afternoon. Winds Monday afternoon will be slightly lower than
today;s winds as the upper level system that brought breezy winds to
the area lifts north.
Most of the region will remain dry through Tuesday night. There is a
low chance for isolated showers and thunderstorms in far eastern
Mohave County at the moisture that may push in tonight lingers over
that area. PWATs start to decrease Monday afternoon through so any
precipitation will be very isolated and impacts will be limited. By
TUesday, PWATs drop enough that precipitation is not expected across
the region including Mohave County. Temperatures will begin an
upward climb on Tuesday as high pressure builds back into the region
as the shortwave lifts away. Monday`s high temperatures will be
similar to today, then on Tuesday it will warm a few degrees and a
moderate heatrisk is expected in most locations outside of the
Southern Great Basin. Anyone with outdoor plans or who are sensitive
to the heat should be aware of the heat on Tuesday, drink extra
water and take breaks in cooler areas.
.LONG TERM...Wednesday through Saturday.
The extended outlook continues to point to an excessively hot period
setting up for a large portion of our area midweek and beyond.
Wednesday looks like the start of an extended period of dangerously
hot conditions with multiple days of near record or record heat
forecast across the Western Mojave Desert including the Barstow
area, across much of Inyo and central and southern Nye counties
including Death Valley National Park, Pahrump, and Beatty, and in
the Las Vegas Valley. Major to extreme Heat Risk is forecast in
these areas through the period where temperatures could approach,
tie, or even break daily heat records. Probably the biggest forecast
challenge will be in deciphering the daily fluctuation in Heat Risk
levels across areas generally south of the I-15 and how this
information will be best relayed to emergency management officials
and to the public. Moderate to major Heat Risk is indicated
throughout the period with Friday standing out as the peak day
featuring widespread high Heat Risk.
This magnitude of heat is dangerous to everyone and proper safety
precautions are recommended including limiting time outdoors and
staying hydrated.
&&
.AVIATION...For Harry Reid...South to southwest breezes are expected
through the afternoon, with gusts over 20KT expected and a moderate
probability (60% chance) for gusts over 25KT between 20Z-02Z today.
Winds will decrease this evening with gusts ending around 03Z-04z.
Moderate confidence in the overnight wind speed forecast. Will be
southwest much of the night before transitions to the south Monday
early morning, however its a 50% chance for winds to remain elevated
at 8-10KT through the night. Kept the elevated winds in through the
night however they may be lighter overnight, especially after
09Z.1031 High confidence that winds increase again Monday morning
after sunrise with the probability for wind speeds over 10KT jumping
back to 80% or higher at 15Z. South to southwesterly breezes are
expected again Monday afternoon with wind speeds and gusts slightly
lower than today`s winds. No significant clouds or weather are
expected through the forecast period. 100F temperatures are likely
19Z to 02Z today and Monday.
For the rest of southern Nevada, northwest Arizona and southeast
California...Souther to southwest winds will gust 20-25KT across
much of the region this afternoon. Winds at KDAG will favor a more
westerly direction but like likely (80% chance) still see gusts over
20KT after 21Z. KBIH will follow typical diurnal directional
patterns through much of the afternoon until a west push moves in
around 00Z. Gusts up to 20KT are possible (60% chance) with the west
winds at KBIH. Winds will decrease this evening and should follow
typical wind patterns overnight. Elevated north to northeast winds
are possible at KBIH 03Z-06Z before typical northwest winds at 8KT
or less set up for the overnight period. Will need to watch for
outflows coming out of south-central Arizona that could push through
southern Mohave County into KEED and KIFP after 09Z, which would
turn winds southeast and bring gusts to around 20KT. No significant
clouds or weather are expected through the forecast period.
&&
.SPOTTER INFORMATION STATEMENT...Spotters are encouraged to report
any significant weather or impacts according to standard operating
procedures.
&&
$$
UPDATE...Woods
SHORT TERM...Nickerson
LONG TERM...Salmen
AVIATION...Nickerson
For more forecast information...see us on our webpage:
https://weather.gov/lasvegas or follow us on Facebook and Twitter