Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 09/03/19
Area Forecast Discussion
National Weather Service Columbia SC
1035 PM EDT Mon Sep 2 2019
.SYNOPSIS...
High pressure north of the area will weaken as Hurricane Dorian
moves slowly northward along the eastern coast of Florida.
Moisture will spread inland through mid to late week as the
Hurricane approaches the GA/SC coast. This will result in a
chance of showers, with possible heavy rain across eastern SC by
midweek. Drier air will spread into the area late in the week
as the Hurricane moves away from the area. Please see the latest
forecast for Dorian issued by the National Hurricane Center.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
Showers in the east section have dissipated with the loss of
heating and further drying behind a mid-level shortwave trough.
Nocturnal cooling and high low-level moisture may lead of areas
of stratus and fog toward sunrise mainly in the east part
because of higher dew points. The HRRR favored stratus mainly
in the east section. The temperature guidance was consistent.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/...
Expect an area of subsidence to the north of Hurricane Dorian
to suppress convective activity on Tuesday with isolated or no
activity along the sea breeze front in the afternoon and
evening.
Hurricane Dorian is forecast to pass within 50 miles of the South
Carolina coast Wednesday Night into Thursday per the latest NHC
advisory. This track, timing, and forecast intensity (Category
2 or 3) would lead to windy conditions across most of the CSRA
and Midlands. Tropical storm force wind gusts and heavy rain
bands will be possible across the Eastern Midlands. There will
likely be a sharp cut off on precipitation amounts somewhere
south and east of I-20/I-26 with the highest totals of 2-4
inches.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
Hurricane Dorian moves away from the region Thursday Night through
Friday Morning. Winds will diminish with clearing skies in the
Eastern Midlands.
A northwest flow aloft behind Dorian will become westerly this
weekend. Expect dry weather with highs in the lower 90s and
lows in the mid to upper 60s.
&&
.AVIATION /03Z TUESDAY THROUGH SATURDAY/...
VFR expected except for early morning fog/stratus possible.
The upper level trough axis is now east of the area and drier
air has moved in. However, onshore flow has brought in enough
low-level moisture that cig/vsby restrictions in early morning
fog/stratus will again be possible, so have included MVFR/IFR
conditions 09z-14z. Mainly expect stratus though since good
mixing will limit fog, but some guidance still hints at fog
developing from the north where winds will be lighter.
Subsidence ahead of Dorian will bring VFR conditions to all
sites by 15z, and convection is not expected. Northeasterly
winds will increase again on Tuesday.
EXTENDED AVIATION OUTLOOK...Periods of restrictions possible
Wednesday through Thursday night associated with Hurricane
Dorian. Strong and gusty northerly winds also expected Wednesday
night through Thursday night.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
GA...None.
SC...None.
&&
$$
Area Forecast Discussion
National Weather Service Duluth MN
646 PM CDT Mon Sep 2 2019
.UPDATE...
Issued at 434 PM CDT Mon Sep 2 2019
Rain has developed/spread quickly into northern Cass and western
Itasca counties. Have updated pops and QPF to account for this
change.
&&
.SHORT TERM...(This evening through Tuesday)
Issued at 343 PM CDT Mon Sep 2 2019
Active weather is still on track to impact a decent portion of the
Northland for this evening and overnight tonight, with increasing
chances of thunderstorms, some of which could be strong to
severe. The main features that will drive this scenario is a
couple of mid-level shortwaves, with the first moving through
late this afternoon and evening from North Dakota, with a second
more amplified shortwave quickly moving in behind the first wave,
which will move through the region late tonight and during the day
Tuesday. A warm frontal zone, characterized by a low-level
baroclinic zone and 925-850 mb theta-e/CAPE gradient draped along
southeastern North Dakota and into central Minnesota and west-
central Wisconsin. There are some questions as to how this event
will evolve overnight as the stronger large-scale forcing is
actually closer to an 850 mb low that will translate across the
Canadian Prairies this evening and over southwestern Ontario late
tonight and Tuesday morning. Ahead of this low will be a very
strong 40 to 50 knot low-level jet (LLJ), which would help to
increase low-level moisture advection and instability, as well as
enhanced convergence at the nose of the LLJ over northeast
Minnesota near midnight tonight. The 02.12z NAM and RAP solutions
appear to have the bulk of the convection to the north, while the
HRRR and WRF ARW and NMM all have convection developing as an MCS
over eastern North Dakota this afternoon and translating
southeast along the theta-e/CAPE gradient. Most-unstable CAPE is
progged around 1000-3000 J/kg per the latest GFS and NAM
solutions, but there should be some strong effective bulk shear
with values around 50 to 70 knots thanks to the strong LLJ. The
main threats appear to be damaging winds, with a smaller threat
for large hail as the mid-level lapse rates are a bit more
marginal. The increased moisture advection could also lead to
periods of heavy rainfall across much of the Northland, which
could lead to some minor flooding in spots. However, a portion of
the forecast area is under a D0 drought from the US Drought
Monitor, so not expecting too much impact from the heavy rainfall.
Eventually, the stronger forcing from the amplified shortwave will
kick off to the east around mid-day Tuesday, helping to diminish
chances of shower and storms. There will be some lingering activity
in the afternoon hours. The main story for Tuesday will be the
region remaining under north to northwesterly cyclonic flow on the
backside of the departing low, which will help enhance cold air
advection aloft. Thinking that there will be minimal sunshine for
Tuesday, so decided to reduce the high temperatures by a few
degrees. Highs Tuesday will warm into the upper 50s north to the
upper 60s and lower 70s over northwest Wisconsin.
.LONG TERM...(Tuesday Night through Monday)
Issued at 337 PM CDT Mon Sep 2 2019
A progressive west-northwest flow pattern will continue to persist
through next weekend according to most large scale model guidance.
High pressure will be building into the western Great Lakes region
Tuesday night and Wednesday, with breezy conditions diminishing
rapidly Tuesday evening. Another fairly chilly airmass will take up
residence over the Minnesota Arrowhead, with temps dipping into the
30s again in many locations Wednesday morning.
The next upstream wave should affect the region Wednesday night and
Thursday, with another chance of showers and a few thunderstorms,
but instability appears less robust than with the wave tonight so at
this time any severe weather threat looks to be extremely limited at
best.
Thereafter, the next chance of organized precipitation appears to be
next weekend - although there are the usual differences in timing
and amplitude that far out, which renders confidence in any specific
solution rather low this far out in such a progressive flow
pattern.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 646 PM CDT Mon Sep 2 2019
VFR at the start of the forecast with some mid clouds from 7k to
12k ft underneath a cirrus shield. Some showers are beginning to
spread into the region from the west. As the rain becomes more
widespread, look for the cigs and vsbys to drop into the MVFR
range. With thunderstorms still possible, cigs and vsbys will drop
into the IFR range with some pockets of BR. Timing of storms is in
question, but still on track from previous forecast. As the system
departs by sunrise, the showers and storms will end and gusty
winds will form and continue to the rest of the forecast.
&&
.MARINE...
Issued at 337 PM CDT Mon Sep 2 2019
Northeast winds continue to gradually increase across all of western
Lake Superior this afternoon as the low level flow field starts to
respond to the strengthening low pressure area to our west. The UMD
offshore buoy is now gusting to almost 20 knots as of 3 PM, and wave
heights are starting to respond per area webcams. A small craft
advisory remains in place for all areas until Tuesday afternoon
as 15-20 knot winds with some higher gusts are expected, along
with wave continuing to build. In addition, widespread coverage of
thunderstorms is still expected overnight tonight, especially in
areas from Silver Bay to the Apostle Island and southward. A few
storms could be strong or severe with locally strong wind gusts
and frequent lightning.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 52 64 44 67 / 100 60 10 0
INL 52 59 42 68 / 90 80 10 0
BRD 60 66 46 69 / 90 10 0 0
HYR 58 70 45 67 / 100 60 10 0
ASX 53 70 45 68 / 100 70 20 0
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
WI...Beach Hazards Statement until 8 PM CDT this evening for WIZ001.
MN...Beach Hazards Statement until 8 PM CDT this evening for MNZ037.
LS...Small Craft Advisory until 10 AM CDT Tuesday for LSZ121-140>148.
&&
$$
UPDATE...GSF
SHORT TERM...JTS
LONG TERM...Miller
AVIATION...GSF
MARINE...Miller
Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
1153 PM EDT Mon Sep 2 2019
.AVIATION...
A modest degree of low level moisture remains in the wake of a weak
cold frontal passage overnight. This will maintain some pockets of
lower VFR cloud during the night, while also leaving the possibility
for some fog formation as winds remain light. Confidence in the
degree of fog formation remains low, but potential does exists for
one or more terminals to briefly dip into IFR during the early
morning hours. This moisture will mix out late morning as winds
steadily shift toward the south and deeper daytime mixing ensues.
This mixing will contribute to an increasingly gusty wind through
the afternoon hour, reaching in excess of 25 knots by afternoon.
Window for possible thunderstorms centered late Tuesday evening as a
strong cold front lifts across the area.
.DTW THRESHOLD PROBABILITIES...
* Low for cigs aob 5000 ft through Tuesday morning
* Low for thunderstorms Tuesday night
&&
.PREV DISCUSSION...
Issued at 342 PM EDT Mon Sep 2 2019
DISCUSSION...
Temperatures rising into the upper 70s to near 80 degrees this
afternoon, with dew pts in the lower 60s is yielding sbcapes around
1000 J/kg with surface cold front sinking south from central Lower
Michigan. Isolated thunderstorms remain possible through the early
evening hours, but RAP soundings suggest the dry mid levels and warm
nose around 600 MB will be difficult to bypass, and will continue to
highlight mainly scattered showers with the bulk of the cape
confined to the 850-650 MB layer.
Consolidating upper level PV/strengthening mid level circulation
taking place over southern Saskatchewan this afternoon, and this
strong PV anomaly looks to be tracking across southern Lake Superior
Tuesday afternoon, with extension of PV filament/jet streak tracking
through southern Lower Michigan during the early evening hours,
providing sufficient large scale forcing to overcome marginal cap
(temp of 9-10 C at 700 MB) and generating a broken-solid line of
storms (70+ pops) with the frontal convergence. Good consensus
amongst the models with the instability/moisture axis arriving
around 0z Wednesday (+/- 3 HRS), and may get storms going on the
prefrontal trough axis out ahead of the main cold front, which is
not too far behind crossing lake Michigan late in the day.
MLcapes of at least 1000 J/kg progged, but 850 MB computed cape
looks even a little better, with steep 700-500 MB mid level lapse
rates around 7.5 C/KM. However, the moisture plume is tending to get
pinched off as it comes out of the Midwest into lower Michigan
(trending more west-east aligned), and even with the strong low
level jet (core tracking through central Lake Huron), not sure the
70 degree dew pt at the surface/17 C dew at 850 MB advertised by the
12z NAM will be realized, which draws concern for the amount of
instability. Also, the active warm front/convective complex over
Wisconsin during the early morning hours of Tuesday is potentially
another factor, and some elevated convection could hold together and
impact the north half of the CWA, or convective debris at the very
least could prevent high temperatures from reaching the forecasted
maxes in the low to mid 80s (based off 850 MB temps aoa 17 C).
Assuming the warm front lifts cleanly north during the day, this
looks to be a solid severe risk for Michigan standards with the good
dynamics. 0-1 KM Bulk shear values hanging around in the 15 to 30
knot range looks to support rotating cells/isolated tornado threat
as well, in addition to the large hail and damaging wind threat.
Front and storms should be east of the CWA around midnight, with
brisk northwest winds advecting noticeably drier air into southeast
Michigan for Wednesday. Low level cold advection through the day,
with maxes likely holding in the lower 70s/around 70 degrees based
off 850 MB temps lowering to 7-8 C.
A favorable radiating/chilly night expected Wednesday night as
center of surface high pressure (1023 MB) settles over southeast
Michigan, with temperatures following the dew pts into the 40s,
outside of the urban heat island of Detroit. Light northerly flow
over Lake Huron could cause some low stratus development to brush
against the Eastern Thumb Region, which looks to be the only
possible fly-in-the-ointment.
The extended forecast begins on Thursday with dry conditions and a
near-neutral advection regime as high pressure begins to slide off
to the east. Column moisture reduction post-FROPA on Wednesday will
be maintained on Thursday with PW values in the 0.50-0.75 range and
surface dewpoints generally below 50F. High temps will be around 70F
on Thursday with overnight lows in the lower 50s. An upper trough
feature on Friday is now being resolved slightly differently as
Hurricane Dorian tracks along the eastern seaboard. Dorian looks to
absorb this first upper level disturbance, although most of the
forced shower activity should remain mainly north of the CWA, along
the coastal portion of the Thumb. A slight increase in low-level
moisture flux should be present with an uptick in WAA from weak
southerly flow elevating PW values above 1.00 by the evening hours.
A largely dry cold front will also move through with this wave and
modify the airmass behind it. Temperatures and dewpoints will be a
few degrees higher on Friday, closer to seasonal norms.
The second impulse aloft tied to a longwave feature will bring a
second trough through, but with a large amount of dry air between H8
and H7, not expecting any precipitation. The main impact from this
will be a sharp increase in wind speeds /up to 25 mph/ as +25 kt H8
winds mix down. Temperatures will decrease again from Saturday
onward as cool and dry Canadian air is funneled down into the Great
Lakes from high pressure over NE MN. The next chance for precip will
not come until the middle of next week.
MARINE...
Light northerly wind following a weak cold front tonight quickly
veers east to southwest as that front returns north during Tuesday
ahead of a strong low pressure system moving in from the Plains. The
strength of this low and a longer fetch of southerly wind brings a
time window for gales Tuesday afternoon across central and northern
portions of Lake Huron before warm air stabilizes conditions over
the water. A strong cold front then brings a line of strong to
severe thunderstorms adding to the hazardous marine conditions
followed by a period of NW gales Tuesday night into Wednesday. A
broad area of high pressure then brings much improved marine
conditions by Wednesday night through late week.
HYDROLOGY...
A strong cold front remains on schedule to move across Southeast
Michigan Tuesday night preceded by scattered to numerous showers and
thunderstorms. The strongest storms occur briefly in any one
location but with locally heavy downpours capable of rainfall
ranging from a quarter to three quarters of an inch. As is usually
the case with thunderstorms, total precipitation amounts will likely
show a high variability across the area. The potential for flooding
will be equally variable and limited to ponding of water on roads
and in poor drainage areas.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
Lake Huron...Small Craft Advisory from noon Tuesday to 4 PM EDT Wednesday for
LHZ441>443.
Gale Watch from Tuesday afternoon through Wednesday morning for
LHZ361>363.
Small Craft Advisory from 10 AM Tuesday to 10 AM EDT Wednesday for
LHZ421-422.
Lake St Clair...Small Craft Advisory from 2 PM Tuesday to 4 AM EDT Wednesday for
LCZ460.
Michigan waters of Lake Erie...Small Craft Advisory from 2 PM Tuesday to 4 AM EDT Wednesday for
LEZ444.
&&
$$
AVIATION.....MR
DISCUSSION...SF/KK
MARINE.......BT
HYDROLOGY....BT
You can obtain your latest National Weather Service forecasts online
at www.weather.gov/detroit.
Area Forecast Discussion
National Weather Service Houston/Galveston TX
1006 PM CDT Mon Sep 2 2019
.DISCUSSION...
A low pressure system over south-central Gulf of Mexico continues
to produce strong showers and thunderstorms. Environmental
conditions continue favorable for additional development of this
system. On the 8 PM EDT NHC Tropical Weather Outlook, a 60 percent
chance of formation through 48 hours and a 70 percent chance of
formation through 5 days was forecast. Regardless of the
development of this system, the track forecast continues a
westward motion into the eastern coasts of Mexico and is not
expected to produce direct impacts across southeast Texas. What is
expected however, are pulses of deep tropical moisture
transported across the Gulf waters and coastal regions from time
to time. This will produce showers and thunderstorms moving
periodically across our local waters and coastal counties
overnight into Tuesday. Elsewhere, a drier air mass and subsidence
will remain in place, limiting shower and thunderstorm
development. A shower or two could possibly develop further inland
across the Harris, Fort Bend, Wharton and Jackson counties
depending on how much moisture actually reaches these areas, if
at all. Lows tonight will range in the mid to upper 70s and highs
will once again reach the mid to upper 90s.
There were a few changes to the previous forecast. PoPs for
tonight and Tuesday were slightly increased for the local waters
and coastal regions. The sky forecast was also adjusted for the
areas expecting to have the highest cloud and rain development.
Additionally, temperatures were slightly adjusted to include the
current surface observation trend. Over the local bays and Gulf
waters, the local pressure gradient is expected to tighten. Wind
speeds were slightly increased for tonight through Tuesday night.
For additional information on the local marine conditions and
current hazards, please refer to the previous Marine Discussion.
The rest of the inherited forecast remains unchanged.
24
&&
.PREV DISCUSSION... /ISSUED 712 PM CDT Mon Sep 2 2019/
AVIATION...
Generally VFR conditions are expected overnight as dry air remains
entrenched over SE TX. NAM12 and the HRRR produce some showers
near the coast after 10z much like this morning but low level
convergence looks a bit weaker compared to last night. Guidance
has been a bit light on winds and bumped winds up a bit on
Tuesday. 43
&&
MARINE.../ISSUED 348 PM CDT Mon Sep 2 2019/
Will keep the SCEC in place for the coastal waters through Tues
evening as winds/seas remain elevated (mainly in response to the
possibly developing tropical wave over the south central Gulf).
All models are keeping the eventual track of this system into
northern Mexico (given the strong ridge of high pressure over the
state) late Weds/early Thurs. The SCEC will likely be extended or
upgraded depending on what this system does. In the meantime,
marine interests should stay up to date on the latest forecasts.
Looking ahead, light offshore winds are expected briefly
Thur/Fri, with light and variable winds possible by the weekend.
41
&&
.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL) 75 98 76 99 77 / 0 0 0 0 0
Houston (IAH) 78 98 78 98 79 / 0 10 10 10 10
Galveston (GLS) 83 93 82 93 82 / 30 40 20 20 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...High Rip Current Risk through Tuesday evening for the following
zones: Brazoria Islands...Galveston Island and Bolivar
Peninsula...Matagorda Islands.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION through Tuesday evening for
the following zones: Coastal waters from Freeport to
Matagorda Ship Channel TX out 20 NM...Coastal waters from
High Island to Freeport TX out 20 NM...Waters from Freeport
to Matagorda Ship Channel TX from 20 to 60 NM...Waters from
High Island to Freeport TX from 20 to 60 NM.
&&
$$
Discussion...24
Aviation...43
Marine...43/41
Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
931 PM CDT Mon Sep 2 2019
.UPDATE...
930 PM CDT
Overall there were no major changes to the going forecast.
However, I did push up the timing of early morning thunderstorms a
couple of hours, especially over north central IL. It appears
that we will have at least some scattered thunderstorms over far
northern IL early Tuesday morning as remnant overnight
thunderstorms to our northwest shift over parts of the area.
Currently we are watching a severe forward propagating line of
southeastward moving thunderstorms, currently about 65 miles to
the northwest of KMSP. This line of storms is likely producing
large hail and strong wind gusts in excess of 60 mph. The movement
is to the southeast at around 60 mph. Given that this movement
will be right along the instability gradient and along the
northward periphery of an EML, with very steep mid-level lapse
rates, it is likely that this MCS will continue for several more
hours tonight.
The main question for us in northern IL is will it make it all
the way into northern IL overnight? Its current movement would
put it near far north central IL around 4 am. While this remains
a possibility, it does appear that instability drops off with
southeastward extent over our area. This could result in the MCS
outrunning the instability overnight, possibly resulting in a
weakening trend as it shifts east-southeastward out of MN. While
questions remain as to how strong these storms will be as the
approach the area overnight, it does appear that some scattered
thunderstorms will already be around over far northern portions of
the area prior to daybreak, so POPs were increased over far
northern IL during this time.
No changes were made to the forecast after early Tuesday morning.
KJB
&&
.SHORT TERM...
220 PM CDT
Through Tonight...
Satellite shows a corridor of extensive cloud cover across
northeast and east-central Iowa this afternoon in conjunction
with a shortwave that is tracking east-southeastward. To the east,
surface obs show an area of convergence across far southern
Wisconsin with better organized and somewhat deeper cumulus
development associated with this which is drifting southeastward.
An axis of instability extends from west to east across this
general region as well. Have seen a few isolated weak radar
returns ins southern WI over the last little while but forecast
soundings show a decent capping inversion. Cannot rule out an
isolated shower across the northern tier or two of IL counties
into early evening which would probably be more closely associated
with the upper wave and be elevated in nature given the capping.
Otherwise, expect thunderstorm chances to hold off until after
daybreak Tuesday morning which will be discussed below. Winds will
be light this evening and will increase overnight as low pressure
tracks across northern Minnesota and high pressure departs the
local area. Expect lows in the mid 60s.
MDB
&&
.LONG TERM...
311 PM CDT
Tuesday through Monday...
The main item of interest for the rest of the short workweek will
be tied to a cold front, both gusty winds and thunderstorm
chances ahead of it on Tuesday, some possibly strong to severe,
as well as a heightened rip current risk for the Lake Michigan
beaches behind this front on Wednesday.
Tuesday`s thunderstorm chances continue to look as if they fall in
two primary time windows: 1.) the morning north of I-80 with
activity shifting out of Wisconsin and 2.) potential for
redeveloping scattered activity ahead of a cold front in the mid-
afternoon, most favored south and east of a Chicago O`Hare to
LaSalle-Peru line. While there is fairly good confidence in those
time windows, sizable uncertainty exists in convective morphology
and coverage within these. In addition, any morning activity will
likely play into the afternoon location of redevelopment and
potentially its magnitude. The main forecast changes were
primarily to refine timing some. Also collaborated with
neighboring offices and SPC to continue to reflect a Slight Risk
type verbiage, though the instability and shear spectrum that is
tapped includes isolated higher end potential conditional on
supercell mode being able to develop in the afternoon. That`s on
the lower end of confidence spectrum right now.
Upstream observational trends this afternoon across the Dakotas
and Minnesota play somewhat into what are expectations are for
early Tuesday morning. The more organized MCS behavior there is
across central Minnesota this evening and into
western/southwestern Wisconsin early overnight, the better
likelihood some activity makes it into far northern Illinois
Tuesday morning. The effective warm front has been struggling to
reach north downstream of the current North Dakota MCS, and as
such this may not yet be the primary convective show, with
potentially more developing further south through the night in a
semi-organized state, especially given the strength of the low-
level jet. This jet will orient across northern Illinois early
Tuesday morning with likely a convectively-enhanced short wave
traversing central Wisconsin. Whether some remnant MCS or elevated
scattered activity, it is likely some convection will be flirting
with far northern Illinois and if organized could make it down to
I-80 by later morning. The severe threat with this looks isolated
at this time, and tied to steepening mid-level lapse rates and
effective shear in the 1-6 km layer increasing to 45 kt.
The footprint of convection and any debris will be key for
afternoon pre-frontal recovery, but given the strength of the
surface pressure gradient and wind field, warm and moist advection
in the low levels should not be completely hampered in the case
of organized morning convection. The surface low, likely at or
just below 1000 mb, will be crossing the U.P. of Michigan through
Tuesday. This is still a ways from the CWA but is closer with a
stronger gradient than last Thursday`s setup, and thus this late
summer cold front will have greater moisture to work with to spark
renewed convection in the region. Southwest wind gusts by early
afternoon are forecast to be 30-35 mph with potential for 40 mph
gusts again dependent on cloud cover. The confluence along and
ahead of the boundary for maximized moisture/instability and
lifting of parcels improves the further northeast along the
boundary, especially into lower Michigan and northern/northwestern
Indiana by later afternoon. If little activity in the morning
though, this may be slightly further west including over Chicago
during peak heating. Dew points should be in the lower 70s at
least with possible mid 70s given upstream conditions.
Temperatures into the 80s, possibly upper, support mixed layer
CAPE in excess of 3000 J/kg in any pre-frontal locations that
receive even just filtered sun into the afternoon. The regime
favors plenty of deep layer shear again with 45-55 kt, and some
turning in the lowest 3 km.
If afternoon convection can redevelop in the CWA...again most
possible favored south and east of Chicago to LaSalle-Peru line...
the mode is likely to be semi-discrete given mainly perpendicular
flow to the boundary, with a trend into early evening to have
some more convective segments as it evolves southeast. Hazards
would include hail especially initially, and wind in segments.
The high instability and wide nature of the CAPE in the vertical
predicted on NAM and RAP soundings would support some significant
hail threat especially in any temporary supercell structures that
can initially develop. Any bowing segments too could be a little
more robust, but that`s even lower confidence in our area right
now. The tornado threat is low in our area compared to lower
Michigan where there is more of a warm advection, slightly backed
low-level flow regime, but any initial supercells would have a
non-zero threat. Overall if having to highlight an area that is
the better looking within the broader Slight Risk for our area,
that would be far northwest Indiana right now.
The front will advance through in the evening bringing drier
conditions. Winds will turn northerly late Tuesday night into
early Wednesday morning, with prolonged gusts of 25 mph into the
shore areas providing building waves and a heightened rip current
risk. A Beach Hazards Statement will be issued in time for this.
Highs on Tuesday look to be about 15 degrees cooler than Tuesday.
On Thursday Night into early Friday, a weak trough in the mid and
low levels will pass across the Great Lakes according to a blend
of the model guidance. This has very limited moisture return and
may struggle to have much for showers during the nighttime hours,
so continue dry for this portion of the forecast. A west-
northwest upper flow pattern will prevail with potential for
short wave disturbances including some semblance on 12Z guidance
of a stronger one Saturday night into Sunday, though centered
mainly just south of the area.
MTF
&&
.AVIATION...
For the 00Z TAFs...
Several concerns:
-Lake boundary pushing in from the north
-Thunderstorm chances and timing late tonight into early Tuesday
-Thunderstorm chances Tuesday afternoon
-Gusty SW winds on Tuesday
Lake boundary will continue to press in from the north, current
timing at ORD is 02z-0215z. MDW a tad later. Showers to the
north should remain there and dissipate as the forcing and focus
is weakening.
Meanwhile, attention is on MCS across MN. Current model suite is a
bit slow (except for maybe the 12z NSSL WRF) with location. If
storms hold their track and speed, they could reach RFD at 9z and
ORD at 10z, but current guidance shows the system moving SE then
more E later tonight, but develop additional showers and storms on
its southern edge. This latter is the solution we followed for the
this TAF set which is earlier than previous PROB30 group. Still
considerable uncertainty on coverage at this point until we follow
the MCS evolution, but feel there will at least be showers and
some embedded storms in the area late tonight into early Tuesday.
Post morning activity, we could have some MVFR or lower VFR
clouds, and this may limit mixing, but we still expect gusty SSW
to become a bit stronger 16-18z as the winds veer a bit more SW.
Soundings suggests low to mid 30s for gusts are possible, MOS is
less aggressive.
Afternoon TS chances at this point appear favored SE of the
terminals, but with soundings depicting some decent elevated CAPE
and good shear, it is possible some form in the vicinity, we just
have low confidence on coverage as much may hinge on the morning.
KMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...None.
IN...None.
LM...Small Craft Advisory...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-
LMZ745...7 AM Tuesday to 10 PM Tuesday.
&&
$$
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Area Forecast Discussion
National Weather Service Newport/Morehead City NC
1016 PM EDT Mon Sep 2 2019
.SYNOPSIS...
A trough of low pressure will linger along the coast through
tonight. Hurricane Dorian will continue to slowly cross Grand
Bahama Island and approach the east coast of Florida tonight into
Tuesday before riding up the Southeast coast through the end of
the workweek. Significant impacts are becoming more likely for
eastern North Carolina. Monitor updates from the National
Hurricane Center for the latest on Dorian.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
As of 1005 PM Monday...Showers have dissipated with loss of
heating and latest run of the HRRR shows no additional
development overnight, so will drop PoPs for the remainder of
the night. Otherwise, no major changes needed to the current
forecast. Conditions will become favorable for some patchy
areas of radiational fog late tonight with clearing skies and
light to calm winds. No changes made to the forecast with low
temperatures upper 60s inland and mostly lower 70s coast.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/...
As of 230 PM Monday...Upper trough will push off the coast as
flow becomes more zonal aloft. Not much forcing or moisture so
expect isolated to widely scattered showers and storms, mainly
diurnally driven. With decent amount of sun shld see highs in
the mid/upr 80s.
&&
.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
As of 230 PM Monday...Tropical Cyclone Dorian will track along
the Carolina coast Wednesday through Friday, bringing the
greatest impacts locally Thursday through Friday morning. Global
guidance has been relatively consistent with the track over the
past day or more, matching the NHC official forecast for the
center of circulation to track northeastward along the coast to
near Cape Hatteras, then departing off toward the northeast.
However, there is still potential for significant shifts in this
forecast track based on what Dorian, which is still over the
Bahamas, does over the next 24 hours and when it is expected to
make the turn northward and begin accelerating toward the
Southeast US. Regardless of the eventually realized track,
impacts will be felt well away from the center of the storm.
Have once again relied on a consensus of the global models for
the official forecast, with the disclaimer that a deterministic
forecast makes it difficult to reflect the range of
possibilities, including the potential for Dorian to track
inland, well off the coast, or potentially make landfall in
eastern North Carolina.
Heavy rainfall continues to be the threat for which there is the
most confidence, as guidance shows a large shield of heavy
precipitation on the west to north side of the system, where
low level moisture convergence is the greatest. Latest QPF has
values of up to 10 to 12 inches near the core of the system,
with locally higher amounts possible. The exact location of the
highest precip will depend on track, but the threat for heavy
rainfall and flash flooding will likely extend across most of
eastern NC.
The local impacts of other hazards, including storm surge and
tropical storm or hurricane force winds, are highly track
dependent. Based on the current track, the greatest threat for
damaging winds will exist along coastal areas, including
coastal Onslow County, the Crystal Coast, and the Inner and
Outer Banks. Also based on the current track, the greatest
threat for storm surge would exist across the southern Pamlico
Sound shorelines, including the soundside of the southern OBX,
Downeast, and the shores of the Neuse River. However, it must
be stressed that even minor adjustments in the track could
result in significant changes to the threats, and all residents
of eastern North Carolina should be preparing for hurricane
force winds and interests vulnerable to storm surge should
monitor subsequent forecasts closely.
Tornadoes are also possible with Dorian, with the right front
quadrant relative to the storm motion being the favored location
for tropical tornado development.
Overall, conditions will likely deteriorate rapidly Thursday
morning, with the greatest impacts felt Thursday through Friday
morning. Tropical Storm force winds could arrive as early as
later in the day Wednesday, so all preparations should be
completed by Wednesday morning.
Dorian is expected to move away from the area late in the day
Friday. Increasing heights aloft will bring a mostly dry
forecast despite the potential for a cold front to cross or
possibly stall over the area over the weekend.
&&
.AVIATION /02Z TUESDAY THROUGH SATURDAY/...
Short Term /through 00Z Wednesday/...
As of 705 PM Monday...VFR conditions continue this evening as a
few scattered showers and embedded tstms end quickly with loss
of heating. With clearing skies, high dewpoints and light to
calm winds, good conditions develop for radiational fog toward
morning and will continue to forecast a period of IFR fog at all
TAF sites from about 09z-13z. VFR conditions then prevail
through Tuesday with only scattered high clouds and minimal
threat of precipitation.
Long Term /Tuesday night through Saturday/...
As of 330 AM Monday...Mainly VFR expected into Wednesday
morning, with brief sub-VFR possible in occasional showers/storms.
Hurricane Dorian is expected to track along the Carolina coast
Wednesday through Friday. This would bring a prolonged period of
likely IFR ceilings, significant visibility reductions in
periods of heavy rainfall, and the potential for significant
LLWS. Dorian is expected to move out of the area by Fri
afternoon with a return to VFR conditions.
&&
.MARINE...
Short Term /through Tue night/...
As of 1015 PM Monday...E/SE winds persist on the coastal waters
at 5-15 knots this evening. Seas continue at 3-5 feet, with a
few 6-footers over the outer periphery of the coastal waters.
SCA`s continue south of Oregon Inlet for the precursor swell
from Hurricane Dorian for 4-7 seas. The swell could briefly
subside Tue before building again Tue night as Hurricane Dorian
begins it`s forecasted track along the SE coast. N/NE winds 5-15
kt early Tue becoming NE/E during the day, strongest winds
south of Hatteras.
Long Term /Wednesday through Saturday/...
As of 330 AM Mon...While there is still uncertainty with the
track of Dorian, there is high confidence that Dorian will bring
hazardous marine conditions to at least the coastal waters
through the end of the workweek. If Dorian tracks along the
Southeast coast as currently expected, conditions will rapidly
deteriorate across all waters later Wednesday through Thursday
morning. Conditions unsafe for any mariners, including strong
winds and exceptionally large dangerous seas, are possible
beginning Thursday. Mariners should continue to monitor the
latest forecasts from NHC concerning Dorian.
&&
.TIDES/COASTAL FLOODING...
As of 230 PM Mon...Elevated tidal levels from the recently
passed lunar perigee and new moon will continue into Tuesday.
Minor/nuisance flooding is expected across low lying areas
adjacent to the sounds once again during high tide. The most
susceptible areas will be along the Crystal Coast and Downeast
Carteret Co.
Swell from Hurricane Dorian will cont to impact the coast
through the rest of the week with an increased rip current risk
along area beaches.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...Beach Hazards Statement through Tuesday evening for NCZ195-196-
199-203>205.
MARINE...Small Craft Advisory until 6 AM EDT Saturday for AMZ152-154-
156-158.
&&
$$
SYNOPSIS...MHX
NEAR TERM...CTC
SHORT TERM...CQD
LONG TERM...CB
AVIATION...CTC/MS/CB
MARINE...CTC/CQD/CB
TIDES/COASTAL FLOODING...MHX
Area Forecast Discussion
National Weather Service Marquette MI
827 PM EDT Mon Sep 2 2019
.SHORT TERM...(This evening through Tuesday)
Issued at 441 PM EDT MON SEP 2 2019
Water vapor imagery and RAP analysis show a trof over eastern Canada
extending s into the Great Lakes and northeastern states. Upstream,
a vigorous shortwave moving across Alberta into Saskatchewan will be
the next feature of interest. At the sfc, cold front associated with
the eastern trof has moved s into central Lwr MI/WI. In its wake,
850mb thermal trof with temps as low as 5-6C into northern Upper MI
today has supported abundant stratocu across much of the fcst area.
With the thermal trof now slipping e, clouds are beginning to thin
out. Well upstream, shra/tsra are already spreading e from se
Saskatchewan and ND toward nw MN in advance of the aforementioned
vigorous shortwave.
Tonight will begin tranquil with sfc high pres initially over
central Lake Superior moving se, crossing eastern Upper MI during
the early overnight period. Brief window of mainly clear skies and
calm/light wind will allow for rapid cooling during the evening.
Favored the low side of guidance for min temps across the central
and east (low/mid 40s across the interior). Temps will likely slip
blo 40F at traditional cold spots. To the w, return flow on the
backside of the high in addition to an increase in clouds will hold
temps up. Increase in wind/clouds over the central/e overnight will
result in temps slowly rising late.
Attention then turns to the well-defined shortwave that will swing
across Lake Superior/Upper MI on Tue aftn. Vigorous dynamics/healthy
height falls (upwards of 150m/12hr at 500mb), and low-level jet
increasing to 45-55kt will likely support a band shra/tsra that will
move across the fcst area overnight/Tue morning. Models have trended
toward better agreement on this system, but as always, can never be
certain on the evolution of convection. Ongoing strong convection
over ND will likely become the main player. If so, it should track
ese track along the stronger MUCAPE instability gradient and pass
just s of Upper MI, perhaps cutting down on pcpn farther n. However,
that seems unlikely in this case given the vigorous dynamics. So, no
matter how the ND convection evolves/tracks, still expect to see
widespread shra/tsra, spreading w to e overnight/Tue morning. 12z
models do show some trend for a farther n push of greater MUCAPE,
and effective shear in excess of 40kt will support organized storm
potential. While stable low-levels will work to inhibit the
potential of strong wind gusts, locally hvy pcpn and low-level jet
upwards of 55kt support some risk of svr winds with strongest
storms. Large hail can`t be ruled out as well. With precipitable
water up to 1.5 inches/around 200pct of normal, expect locally hvy
rainfall.
Main area of shra/tsra will shift e of the fcst area late
morning/early aftn. Whether sfc based convection will then fire
along cold front prior to it exiting the fcst area remains to be
seen. S central and eastern fcst area would be susceptible to
stronger storms along front if they do develop. Otherwise, secondary
cold front/trof dropping into the area should result in sct to nmrs
shra in the aftn, especially across the w.
Finally, track of sfc low w to e across Lake Superior on a line
probably passing just n of Copper Harbor increases the potential of
strong winds in the aftn, especially across the Keweenaw under
favorable wnw wind direction. Decent caa, favorable track of the
vigorous vort max and pres falls upwards of 7-10mb/3hr exiting to
the e and incoming pres rises of 3-5mb/3hr from the w will be
enhancement factors for strong winds. For now, have gusts up to 40-
45mph across the Keweenaw in the aftn. In addition, ahead of the
front, there will be a brief window for strong winds over the
eastern fcst area during the late morning/early aftn as winds veer
thru the favorable southerly direction. Stability will be a
negative, but the passage of the pres fall max just n of that area
could be sufficient to lead to a couple of hrs of gusts to around
40mph.
.LONG TERM...(Tuesday night through Monday)
Issued at 359 PM EDT MON SEP 2 2019
This long-term period is quite symbolic of the transition from
summer to fall across Upper Michigan. An exiting low pressure system
Tuesday night will leave behind some remnant showers and persistent
clouds. Skies begin to clear again under high pressure on Wednesday,
only to fill back in Thursday afternoon. A weaker shortwave will
pass through Upper Michigan Thursday bringing showers across Upper
Michigan as another trough digs south through Canada, extending
chances for rain through Friday. Upper Michigan will see much cooler
weather this weekend under high pressure as a shortwave digs south
across the NW Pacific. This shortwave moves east on Monday bringing
another chance for rain during the early portions of next week.
An exiting low on Tuesday night will become slowly replaced by high
pressure and a broad area of subsidence by Wednesday morning.
Generally clear skies should be expected by mid morning across Upper
Michigan. With northerly flow remaining behind Tuesday`s shortwave,
not expecting much warming on Wednesday, as highs remain in the low
to mid 60s. This high pressure is expected to move east overnight on
Wednesday, allowing weak southerly flow to return to the UP. With an
incoming shortwave, not expecting much of a warmup Thursday with
increasing cloud coverage from weak WAA and q-vector conv. PoPs
slowly increase to chance ahead of the advancing shortwave on
Thursday morning. Overall moisture is lacking on Thursday as NAM and
EC keep things to the north. GFS tracks a fair amount across Upper
Michigan, but keeps QPF amounts under a 0.10 inch.
Slight chance PoPs persist through Thursday into Friday as an area
of low pressure to the north through Canada stretches a trough and
cold front south into the Upper Great Lakes region. Moisture for
this round looks better for the GFS, but differences between EC and
GEM leave some uncertainty. There remains differences between best
area of forcing as well as the cold front swings through Friday,
leaving CAA to cut off most of the lift by mid-afternoon. Overall, a
enough q-vector conv with weak WAA along the shortwave will produce
rain showers for most of Upper Michigan. Amounts remain uncertain
for now, but guidance would suggest no more than 0.25 inches.
Behind the cold front on Friday, CAA from Canada funnels in 850mb
temperatures to near 0C. Model timing differences remain, but it is
likely some locations near Upper Michigan will have 850 temps fall
below 0C. With NW to N flow expected, a few lake-effect showers may
persist into Saturday, as a high pressure sinks south from the
Canadian Rockies. Northerly winds will cut off as the high moves
further east through the Upper Great Lakes. Guidances for high
temperatures this weekend continue to forecast temps near or below
60 degrees on Saturday and Sunday.
Guidance for the early parts of next week begin to diverge as both
GFS and EC show a shortwave digging south across the Pacific NW
before moving eastward through the CONUS. Both show precip across
Upper Michigan in the early portions of the week, but GFS is more
Monday night, with GEM and EC on Tuesday night. Overall, looks like
an up and down forecast with typical fall UP weather becoming more
present.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 809 PM EDT MON SEP 2 2019
MVFR stratocu has finally cleared out at all the terminals early this
evening and expect VFR conditions to continue through this
evening. Overnight into Tue morning, a vigorous disturbance
approaching from the w will likely spread an area of shra/tsra
across Upper MI, resulting in conditions falling to IFR at all
terminals for at least a few hrs. Gusty se to s winds are also
expected to develop along with LLWS as 45-55kt low-level jet
translates across the area. Winds will become very gusty (30-40
kt) out of the w-nw in the wake of a cold frontal passage Tue
afternoon as cigs improve to MVFR and rain ends. &&
.MARINE...(For the 4 PM Lake Superior forecast issuance)
Issued at 441 PM EDT MON SEP 2 2019
Vigorous low pres system will track w to e across Lake Superior on
Tue. Ahead of this low pres, winds will ramp up tonight, and expect
se to s gales of 35-40kt to develop Tue morning over the e half of
Lake Superior, particularly at high obs platforms. The highest obs
platforms could see brief gusts to 45kt. Although gale warning does
not include western Lake Superior, strong thunderstorms moving
across the Upper Lakes late tonight/early Tue could result in a few
hrs of gale force gusts in that area as well. As the low tracks
across the lake on Tue, winds will switch to the w and then nw.
Track of the low pres should result in these winds reaching gale
force over s central/se Lake Superior Tue aftn/early evening. Winds
will then diminish w to e to mostly under 20kt Tue night/Wed. Light
winds will prevail on Thu. Low pres passing n of Lake Superior on
Fri will usher in a chilly air mass heading into the weekend. The
unstable conditions over the lake will likely result in gusty winds
up to 25-30kt.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
Lakeshore Flood Advisory from 8 AM to 8 PM EDT Tuesday for
MIZ014.
Beach Hazards Statement until 9 PM EDT this evening for MIZ005-
006.
Lake Superior...
Gale Warning from 8 AM to 9 PM EDT Tuesday for LSZ250-251-267.
Gale Warning from 7 AM to 9 PM EDT Tuesday for LSZ264>266.
Lake Michigan...
Gale Warning from 6 AM to 11 PM EDT Tuesday for LMZ221-248-250.
&&
$$
SHORT TERM...Rolfson
LONG TERM...JAW
AVIATION...Voss
MARINE...Rolfson
Area Forecast Discussion
National Weather Service Reno NV
200 PM PDT Mon Sep 2 2019
.Synopsis...
Extensive monsoon moisture will lift northward into the region
bringing increasing chances for showers and thunderstorms through
Thursday. Storms will be capable of producing strong outflow winds,
frequent lightning, and localized flash flooding. Drier and breezier
conditions move in late Thursday into Friday and the weekend.
&&
.Discussion...
* Main forecast concerns over the next few days center around
thunderstorm chances as an impressive monsoon moisture surge
lifts northward through Thursday. Forecast precipitable water
values over 200% of normal by Wednesday AM seen in ensemble
guidance. This generally leads to a flash flood focus but new
fire starts and strong outflows are of course on the table as
well.
* Isolated to scattered storms today and Tuesday. Eastern Sierra has
highest risk per recent HREF, but storms could also zip up the
Pine Nuts and even into Reno vicinity Tuesday PM along the zephyr
boundary.
* Wednesday is the wildcard where moisture overspreads the entire
region. Scenario with that much moisture usually favors extensive
cloud cover with just isolated showers and t-storms. But if we
break out some sun, storm coverage/intensity/risks would be
higher. Won`t really have a good handle on that until we get
within the 18-36 hour window of storm-scale HREF and HRRR guidance.
* Wednesday night into Thursday sees a Pacific trough kick through
providing more forcing for storms. That may be the timeframe of
greatest storm threat with better instability signals and stronger
flow aloft. Could see a few severe storms NE Cal and far NW Nev
(more so up into Oregon). Post t-storm W/SW gradient winds are
expected especially near/west Hwy 395 Thursday PM. Could present a
fire weather concern with any new starts from lightning, however
humidities will not be overly low.
* Into Friday and the weekend much drier conditions are favored.
Ensemble guidance has another, deeper trough moving into the
region this weekend into early next week, which would translate to
breezier days. Fire weather concerns if that pans out. Depending
on intensity of the trough, temperatures could cool well below
normal early next week along with a risk of some "fall" showers.
-Chris
&&
.Aviation...
Main forecast concerns over the next few days center around
thunderstorm chances as an impressive monsoon moisture surge
lifts northward through Thursday. Forecast precipitable water
values over 200% of normal by Wednesday.
* Isolated storms with strong outflows and brief heavy rains today
and Tuesday. Eastern Sierra (MMH) has highest risk these days.
Wednesday is the wildcard. Scenario with that much moisture
usually favors extensive cloud cover with just isolated showers
and t-storms. But if we break out storm coverage/intensity/risks
would be higher. Wednesday night into Thursday sees a trough kick
through providing more forcing for storms before drier and
breezier conditions sweep through from west to east late day. That
may be the timeframe of greatest storm threat.
* Rough probabilities for t-storm impacts including MVFR-IFR rains,
strong outflows, lightning, and hail at various TAF sites around
the region for Mon/Tue/Wed/Thurs: RNO, CXP, MEV 5/20/30/40%. TRK,
TVL 5/20/30/20%. MMH 25/70/70/40%.
-Chris
&&
.REV Watches/Warnings/Advisories...
NV...None.
CA...None.
&&
$$
For more information from the National Weather Service visit...
http://weather.gov/reno
Area Forecast Discussion
National Weather Service Las Vegas NV
234 PM PDT Mon Sep 2 2019
.SYNOPSIS...Increasing thunderstorm activity is expected this week
as monsoonal moisture overspreads the region. Daily thunderstorm
chances will be greatest over the higher terrain, but isolated
storms may drift into the valleys at times. Temperatures will be
at or above normal for early September.
&&
.DISCUSSION...through next Monday.
Extensive cloud shield associated with a MCV continues to lift north
across Inyo, Esmeralda and Nye counties. Radar detecting scattered
showers under the cloud shield with isolated thunderstorms
developing along the southern Sierra Crest. Elsewhere, area of
northern Arizona that has seen the greatest amount of sunshine seeing
isolated thunderstorms along Hurricane Cliff and around Mt.
Trumbull. Visible satellite shows agitated cumulus over the mountains
of southern Mohave, southern Clark and western San Bernardino
counties.
So far, the HRRR was spot on with development of northern Mohave
county, as well as ahead of the MCV. Consecutive HRRR runs continue
to suggest very limited action in area of subsidence on backside of
exiting MCV. Some of the other convective allowing models slightly
more aggressive this evening across the Mojave Desert than the HRRR
so kept some mention of thunderstorms in the forecast. A few showers
or thunderstorms will continue in vicinity of the MCV overnight as it
lift and begins to shear apart across Esmeralda and northern Nye
counties.
For Tuesday and Wednesday. Other than a trough nearing the northern
California coast Wednesday afternoon, no upper level feature evident
in the models moving around the western periphery of the ridge that
would help organize convection. Therefore, forecast based on
afternoon/evening thunderstorms primarily over the higher terrain.
Tuesday and Wednesday will be the warmest days with readings running
up to 6 degrees above normal. Can`t say bye to 105 for Las Vegas
quite yet.
Thursday and Beyond. A threat of showers and thunderstorms exists
Thursday ahead of incoming trough. Friday-Monday much of the area
will see the moisture get scoured out except Mohave County where a
slight chance of thunderstorms continues. Downward trend in
temperatures next weekend.
&&
.AVIATION...For McCarran...Can not rule out a shower or
isolated thunderstorm over the mountains south and west of Las
Vegas. Probability of a storm hitting the valley terminals is looking
less likely so leaning toward removing VCTS in the 00Z forecast
issuance. A nearby thunderstorm may produce gusty, erratic outflow
winds briefly, but overall winds should favor typical downvalley
overnight. Showers and thunderstorms look to favor the higher
terrain Tuesday with outflow winds potentially impacting the
terminal.
For the rest of southern Nevada, northwest Arizona and southeast
California...Scattered showers and isolated thunderstorms are
expected to continue into the evening across most of the southern
Great Basin and Mojave Desert. Gusty winds, localized heavy rain and
small hail will be possible with storms. Outside of thunderstorm
influence, southerly breezes around 10-15 knots are expected through
the late afternoon with generally light, diurnal winds overnight.
Showers and thunderstorms look to favor the higher terrain Tuesday
with gusty winds, heavy rain and small hail again possible.
&&
.SPOTTER INFORMATION STATEMENT...Scattered thunderstorms are
expected the next few days. Spotters are encouraged to report
flooding, wind damage, and dust impacts according to standard
operating procedures.
&&
$$
Pierce
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