Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 06/12/23
Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
855 PM CDT Sun Jun 11 2023
.UPDATE...
Issued at 853 PM CDT Sun Jun 11 2023
Surface high pressure will be over the region tonight, with clear
skies, light winds, and cool temperatures. Overnight lows seem on
track for the time being, as well as other weather elements
through 12Z. No significant changes needed.
&&
.SHORT TERM...(This Evening through Monday Night)
Issued at 241 PM CDT Sun Jun 11 2023
Key Message:
* Canadian high pressure will bring dry conditions, with Monday`s
highs warming about 5 degrees from today.
Canadian high pressure over eastern ND has been leading to
northeasterly winds and comfortable conditions with temps in the
upper 60s and lower 70s and dewpoints in the low to mid 40s. This
high will drop south across the region tonight and continue
southward on Monday as an upper ridge builds over the western CONUS
and a trough spins over the Great Lakes.
With the high, expect a mostly clear sky, light winds, and near
normal highs through Monday. Lows tonight though will be about 5
degrees below normal under the high and fall into the mid-upper 40s
over much of the region. With dewpoints this afternoon in the low-
mid 40s, thinking that ground fog tonight will be limited and didn`t
add it to the forecast. If we were to see some fog, thinking it
would be in the low lying areas of the James River, where there`s
overland flooding that would provide a little more low level
moisture and the winds are the lightest. Finally, do want to mention
for some smoke aloft to move across the area tomorrow, as indicated
by the HRRR Smoke forecast. Didn`t adjust the sky cover forecast for
that yet, but will be something to watch.
.LONG TERM...(Tuesday through Sunday)
Issued at 241 PM CDT Sun Jun 11 2023
Key Message:
* Above normal temperatures and dry for the middle of the work week,
then increasing precipitation chances (20-40%) on Thursday as a
weak low moves through the area.
Dry conditions remain in place on Tuesday, but with increasing
influence of the upper ridge to the northwest, we`ll see
temperatures back above normal. Models continuing to highlight the
potential for a backdoor cold front on Tuesday night, but mainly
expect clouds for our northeastern CWA and the precipitation staying
to the northeast. The previously mentioned upper ridge will bring
continued warmth on Wednesday, with highs in the upper 80s.
There is the potential for an unsettled pattern for the second half
of the work week into next weekend, but confidence on any specific
solution is low right now. The larger scale differences can be seen
in the ensemble clusters for the Days 3-7 period, with differences
on the amplification/location of the upper trough in the Canadian
Prairies (leading to the surface low moving through SD on Thursday),
along with the next upper trough next weekend somewhere along the
western coast of CONUS/Canada.
For Thursday, the larger scale uncertainty is also influencing both
the forcing in our area and the instability in the
deterministic/ensembles. For example, the EC-Ens members are largely
sub 500 J/kg for SB CAPE, while the GEFS peaking out more towards
the 1000 J/kg area. While the 0-6km shear does depend on the
amplitude of the upper wave, there is some consistency in the
potential for some overlap of 20-35kt shear with some instability,
so thunderstorms are possible (20-40%), but severe threat will
depend on the finer scale details. CSU ML probs (GEFS based) do keep
the 5% probs to the south of the area for Thurs and since that`s the
more aggressive ensemble on instability, the severe threat is likely
low.
With the front/low moving through on Thursday, do expect a slight
cool down for Friday (near normal), but then warming back above
normal for the weekend and into next week. Precipitation chances
heading into the weekend will depend on any shortwaves ejecting out
of the developing upper trough along the west coast, so just general
slights (20%) cover into the weekend.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday Evening)
Issued at 635 PM CDT Sun Jun 11 2023
Terminals KABR,KATY,KPIR,KMBG
VFR conditions are forecast through the TAF period. Very isolated
pockets of shallow ground fog may be found early Monday morning
around the James River valley. Also, may be dealing with smoke
aloft once again by Monday afternoon/evening.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...None.
MN...None.
&&
$$
UPDATE...TMT
SHORT TERM...SRF
LONG TERM...SRF
AVIATION...TMT
Area Forecast Discussion
National Weather Service Goodland KS
547 PM MDT Sun Jun 11 2023
.SHORT TERM...(This evening through Tuesday Night)
Issued at 242 PM MDT Sun Jun 11 2023
At the start of the short term period, the latest upper air RAP
analysis shows the CWA having a generally westerly flow aloft being
underneath the peak of an upper air ridge with an upper air low
spinning over southern CA. Current surface observations along with
satellite imagery report mostly northwesterly surface winds along
with mostly cloudy skies across the CWA. Going into the evening,
models forecast a shortwave disturbance moving slowly through the
ridge and being seen mostly over the southern portions of the CWA as
well as off to the west. At the surface, model guidance shows
showers and thunderstorms developing in the Colorado Front Range
along a stationary front and moving eastward into the western
portions of the CWA during the evening hours. Upon looking at severe
weather potential, CAPE values look to be generally less than 1000
J/kg in the CWA today with the maximum being in the southwestern
quadrant around 500 J/kg. Forecast model 0-6km shear values look to
be around 30-50 kts across the region with again the higher values
once again seen in southwestern quadrant again. With the CAPE values
being rather low, the marginal risk that the SPC has for portions of
Kit Carson, Cheyenne, and a sliver of Greeley counties looks to be
well merited though it looks like the better chances for severe
weather will be west of the CWA tonight. Possible hazards if a storm
becomes severe looks to be large hail up to a quarter in size and
strong gusts up to 60 mph, but not the best confidence in this
occurring within the CWA tonight. The primary concern for tonight
looks to be possible heavy rain which may lead to flash flooding
particularly for areas in the southwestern quadrant. PWAT values in
these areas look to be around the 1 inch mark when showers and
storms pass through this evening and going through the night.
Currently, QPF values look to range between a few hundredths to
around 1 inch in central Cheyenne county. Will continue to monitor
these possible flash flooding concerns and issue flood products if
needed through the night. Overnight lows look to range between the
lower and middle 50s.
On Monday, model guidance shows the CWA still underneath the upper
air ridge being between an upper air low to the west over NV/UT and
another upper air low over Lake Michigan. By the evening hours, the
ridge over the CWA is pushed eastward by the western low moving
closer the CO and is flattened quite a bit by the strong eastern low
blocking it having moved into MI. A shortwave disturbance is seen
passing by the CWA in the flow to the south as well. At the surface,
forecast models show the precipitation chances from the previous day
continuing throughout the entire day and increasing quite a bit in
the evening along and west of KS-25 during the late afternoon and
evening hours. Models continue to forecast the good amount of
moisture coming into the area at the 850-500mb layer during the day
along with PWAT values across the CWA being between 1-1.3 inches.
Excessive rainfall looks to be a concern along with possible flash
flooding as the forecast shows a broader area in the western two-
thirds of the CWA with around 0.50 to around 1.25 inches of QPF.
This lines up well with the WPC`s marginal to slight excessive
rainfall risk in their latest Day 2 outlook, so will continue to
monitor these conditions going forward. When looking at model
forecast convective parameters, CAPE values look to be around 1000
J/kg along and west of the CO border with areas south of I-70 seeing
bulk shear values around 30-40 kts. When overlapping these 2 areas
of higher values, generally the same area from Sunday may see the
potential for an isolated severe thunderstorm or two on Monday.
Outside of the primary heavy rain threat, possible severe storm
threats include strong wind gusts and large hail. Will monitor this
as well. Monday`s daytime highs look to be in the lower 60s to
middle 70s range followed by overnight lows in the upper 40s to
middle 50s.
For Tuesday, forecast models depict a rather undetermined and
variable flow over the CWA day being north of the aforementioned
high throughout the day with the western low weakening a bit and
moving over the CWA by the evening. Another shortwave disturbance is
seen passing through the flow over the CWA once again in the
evening. At the surface, precipitation chances look to continue in
the morning and the afternoon before tapering off in the evening for
the CWA. When looking at convective potential, the NAM shows some
late afternoon CAPE values between 1000-2000 J/kg within the CWA,
but relatively low 0-6km shear compared to the previous days. Not
anticipating any organized severe weather for Tuesday at this time,
but will monitor in case future model runs begin to show otherwise.
NAM PWAT values look to be under an inch generally in the western
portions of the CWA (where there are better precipitation chances)
while the eastern portions see PWAT values around an inch. Will
monitor for flooding potential on Tuesday particularly if the CWA
sees good rainfall on the previous days. Daytime highs for Tuesday
range between the middle 60s and upper 70s while overnight lows are
forecasted to be between the upper 40s and lower 50s.
.LONG TERM...(Wednesday through Sunday)
Issued at 115 PM MDT Sun Jun 11 2023
The central plains will be under zonal flow aloft through the long
term period, caught between persistent low pressure over the
northern Rockies/Canada and a ridge over Mexico. Occasional
shortwaves in the flow will provide lift for near daily chances of
showers and thunderstorms. Exact timing and tracks of particular
shortwaves vary from model to model, so hard to pin down any one
day as having better chances for thunderstorms than others.
However, storms will be moving in the typical west to east motion
and peak during the afternoon and evening hours. Deep layer shear
starts the period rather weak, at 20 kts or less, on Wednesday
and Thursday, but then increases to around 40 kts on Thursday and
50 kts by Friday, suggesting that if instability and lift are
sufficient for thunderstorms to develop there would be a severe
risk towards the end of the week. The deep layer shear remains
favorable over the weekend, 30 kts or higher, though models begin
to disagree on the available moisture/instability with a dry
westerly wind trying to take hold in the lower levels. However
there is enough uncertainty to at least keep a mention of
thunderstorms through the weekend.
The temperature trend through the long term period will be for
near normal temperatures for Wednesday and Thursday transitioning
to above normal by late in the week and into the weekend.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 545 PM MDT Sun Jun 11 2023
GLD: Convection, presently developing along the CO Front Range,
will slowly progress east toward the CO/KS border this evening and
overnight. Sub-VFR conditions associated with lingering/decaying
convection are possible late this evening and overnight (mainly in
the 04-09Z time frame), though.. confidence is low with regard to
whether or not the GLD terminal will be directly impacted. Modest
southeasterly low-level flow may foster the development of
MVFR/IFR ceilings (and convective remnants may foster the
development of showers) late Monday morning into the afternoon --
though confidence is well below average. Expect an increasing
potential for showers/storms late Monday afternoon and evening..
as another round of diurnal convection (emanating from the Palmer
Divide) progresses east toward the CO/KS border by the end of the
TAF period (~00Z Tue). Light /8-14 knot/ E winds (this evening)
will gradually veer to the SE (overnight).. remaining
southeasterly through the day on Monday.
MCK: VFR conditions will prevail through the TAF period, with
ceilings predominately confined at/above 4,500 ft AGL. Light
(6-12 knot) ENE winds will gradually veer to the ESE overnight,
further veering to the SE during the day on Monday.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...076
LONG TERM...024
AVIATION...Vincent
Area Forecast Discussion
National Weather Service Indianapolis IN
1158 PM EDT Sun Jun 11 2023
...Updated Aviation Discussion...
.Forecast Update...
Issued at 731 PM EDT Sun Jun 11 2023
The atmosphere has stabilized over all of central Indiana due
to the widespread convection that is now ending northwest to
southeast and the passage of the cold front. Based on this and
lightning trends, pulled not only severe mention from the HWO but
also the thunder mention in that product and the grids. Will also
pull it from weather story. Radar and CAMs suggest the showers will
move out of eastern sections of the forecast area by 11 pm.
MESH and legacy radar products are estimating the heaviest rain fell
in a corridor from near Bloomington to near Shelbyville with over
two inches estimated over some of this corridor. Meanwhile, IRIS
reports have right around 2 inches in a few locales within this
corridor. Most but not all areas north of I-70 saw an inch or less.
So far Indianapolis International Airport has has 0.64 inches. Some
far northwestern sections, including Lafayette, have seen less than
a quarter inch. Even the two plus inch amounts were not enough to
cause any flooding concerns based on the very dry antecedent
conditions.
Satellite and BUFKIT soundings suggest the stratocu will linger
through the night in cyclonic flow aloft around the Lake Superior
upper low. This will keep temperatures from falling much lower than
50 degrees overnight despite the cold air advection in the wake of
the front as north winds will gust to 25 mph through Midnight.
&&
.Short Term...(This evening through Monday)
Issued at 252 PM EDT Sun Jun 11 2023
- Scattered showers, isolated thunder this afternoon and early
evening.
- Decreasing cloudiness overnight
- Mostly Sunny and cool on Monday
Surface analysis early this afternoon shows low pressure centered
over SE IL, poised to push into and across Central Indiana. A warm
front extending east across Central Indiana, close to I-70. Cyclonic
lower level flow was in place across the forecast area. Radar shows
an area of showers north of the warm front over northern Indiana and
northern Central Indiana. An area of convection was developing in SE
Illinois within the warm sector and was pushing northeast toward
the southern half of Central Indiana. Water Vapor imagery shows low
pressure aloft near Lake Superior with a short wave trough extending
southwest across Illinois and into the Mississippi Valley.
This afternoon and early evening...
The low pressure system over SE Illinois will quickly push across
Central Indiana late this afternoon and early this evening, closely
traversing the laid out warm front. This will bring continued
showers north of the low this afternoon and early evening with
Thunderstorms and some wrap-around showers across the southern half
of the state. HRRR shows the bulk of precipitation exiting central
Indiana near 01Z-02Z, as the low exits at that time. Thus will keep
high pops in place late this afternoon. During 01Z-02Z as the system
departs, we will begin trending pops downward toward a dry forecast
thereafter starting at 03Z.
Overnight...
Models suggest cyclonic flow will remain in place aloft overnight as
the upper low over the Great Lakes is expected to be stalled for the
next couple of days. However in the wake of the short wave that will
push across Central Indiana this evening, subsidence is expected to
begin. Forecast soundings show significant mid level drying through
the night. Lower levels that are initially saturated at 04Z, trend
toward a dry column by 12Z. Thus will trend towards decreasing
cloudiness overnight. Given the ongoing cold air advection in the
wake of the cold lows should fall to the lower 50s overnight.
Monday...
Models suggest continued subsidence and NW flow aloft as the upper
level low remains across the Great Lakes. Surface high pressure is
expected to continue to be anchored over the plains states and begin
to nudge southeast due to the flow aloft. Forecast soundings through
the day show a dry column, but convective temperatures appear to be
reached in the afternoon. Cu clouds will develop and these clouds
should remain rather flat topped due to an inversion aloft. Thus
Mostly sunny in the morning, partly cloudy in the afternoon. Given
the cool 850mb temps, highs in the lower 70s will be expected.
&&
.Long Term...(Monday night through Sunday)
Issued at 252 PM EDT Sun Jun 11 2023
Monday night through Wednesday night...
An upper level low moving across the Great Lakes region will
continue to influence weather across central Indiana early in the
period. Look for cool and quiet weather conditions Monday night with
a dry airmass in place. The upper low will drift southeast towards
southern Michigan on Tuesday and make its closest approach to
central Indiana. Expect showers to overspread northern portions of
the area with increasing large scale ascent and enhanced moisture
advection off the western Great Lakes. Guidance shows a deformation
zone developing which may help enhance precipitation across the
north. Occasional wind gusts around 30-35 mph will be possible
during the afternoon as the pressure gradient tightens, but these
winds will diminish during the evening.
The upper low will move east of the region Wednesday with mostly
quiet weather conditions. Daytime heating within a modestly moist
low-level environment may promote a few isolated afternoon showers,
but most locations should remain dry. Increasing heights aloft will
allow temperatures to warmup through the week. Below normal
temperatures to start the period return to near seasonal by
Wednesday.
Thursday through Sunday...
Confidence begins to decrease towards the latter half of the period
due to a larger spread in model solutions. Guidance generally show a
disorganized front associated with an upper wave moving in from the
north late Thursday. Modest overall forcing and limited moisture
ahead of this boundary may promote scattered convection, mainly in
the afternoon. The pattern looks to remain relatively active as
models show a series of low pressure systems developing across the
plains and moving towards the region within W/NW flow aloft.
Confidence in these systems is low at this time with much of the
rain potential depending on more mesoscale factors that are hard to
determine this far out. That being said, ensembles are clustering
better to the southwest of Indiana for any potential MCS or more
organized complexes of storms.
&&
.Aviation...(06Z TAF Issuance)
Issued at 1158 PM EDT Sun Jun 11 2023
Impacts:
* IFR ceilings for most locations through the night
* May briefly improve to MVFR early-mid morning before returning to
VFR
* Gusts 15-20 knots this afternoon
Discussion:
Residual moisture behind the cold front will result in a band of
IFR stratus progressing through the area tonight. Locations that
aren`t already IFR will likely drop at least briefly to IFR. This
may briefly improve to MVFR early-mid morning before returning to
VFR with only some diurnal cumulus and basis around 4-5 thousand
feet during the afternoon. This may fill in again late afternoon
into evening as another area of enhanced moisture moves into
Indiana, but ceiling heights will be high enough that VFR is
expected to prevail late afternoon into the evening.
Mixing and momentum transfer may be enough for 15-20 knot wind
gusts, at least briefly, during the afternoon at all sites. This
should diminish by evening as winds shift around to westerly and
weaken.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
Update...MK
Short Term...Puma
Long Term...White/Melo
Aviation...BRB
Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
1043 PM CDT Sun Jun 11 2023
.DISCUSSION...(This evening through Sunday)
Issued at 335 PM CDT Sun Jun 11 2023
KEY MESSAGES:
- Quiet weather for much of this week, with our next chance for rain
across much of the area Friday into Saturday.
- Elevated fire weather conditions are possible for the next few
days due to low relative humidity and breezy winds.
Visible satellite shows clear skies over majority of Minnesota and a
few scattered CU over Eau Claire county in western Wisconsin. It`s a
beautiful day with vibrant blue skies and perfect temperatures in
the 60s and lower 70s. We will find ourselves underneath a
significant amount of subsidence over the first few days of the
forecast period, with surface high pressure centered over the
Central Plains. The pattern will be slow to evolve due to an upper
level low pressure pivoting over the Great Lakes, creating a
blocking scenario downstream. This will result in northerly flow
aloft through Tuesday, which coupled with surface high pressure will
keep skies clear with basically no lift to be found throughout the
entire troposphere. Recent guidance does suggest that the upper
level low may pivot far enough west for a few isolated showers
across Rusk/Chippewa/Eau Claire counties Monday Afternoon. Any
precip will be light with a few hundredths possible on the high end.
Fire weather could be the greatest concern for us over the next few
days, with MinRH values dropping into the 20s through Wednesday
afternoon, alongside fairly breezy surface winds at 10-15mph with
some gusts to 20-25mph possible. Fuel susceptibility is likely
mixed, with some areas having seen meaningful rainfall over the
weekend, but majority did not benefit from any widespread precip.
This should result in a few days of elevated fire weather
conditions, with additional attention on areas across
central/western MN.
The high pressure moves off by Wednesday with upper level flow
remaining north to northwesterly, which gives us very limited
potential for even isolated weak showers let alone storms.
Temperatures likely warm up to the mid to upper 80s as this pattern
persists through Friday. Temperatures peak on Thursday with an area
of lower 90s pushing into western MN, but by Friday the pattern
begins to evolve as we finally see a source of lift arrive in the
form of a narrow trough. 500mb height falls arrive as early as
sunrise Friday, with the longer range deterministic global models
all in fairly decent agreement on a line of showers developing along
a weak boundary. What`s uncertain and is a limiting factor is
moisture availability. Guidance shows no meaningful moisture source
to support more than isolated to scattered weak showers and storms.
NBM does populate 20 to 30 PoPS, which are justified for
isolated/scattered showers or storms, but until we have access to a
better moisture source we will remain pessimistic for any significant
widespread precipitation until after next weekend.
&&
.AVIATION...(For the 06Z TAFS through 06Z Monday night)
Issued at 1041 PM CDT Sun Jun 11 2023
After a night of light and variable winds, we`ll see them switch
over to the northwest for Monday. Forecast soundings show deep mixing
occurring on Monday, likely in excess of 8k feet. As mixing builds
to that level during the late morning, we`ll start mixing down some
winds in the 20-25 kt range. RAP forecast soundings also show a cu
field developing over all but RWF. SCT coverage is expected in MN,
though it will likely go BKN at times in WI, where a stray shower
can`t be ruled out, though given how dry soundings are below the
cloud base, kept any precip mention out of RNH/EAU.
KMSP...VFR throughout. Winds will be a bit squirrelly overnight, but
rather than put in 2 or 3 additional lines for pointless winds shifts
with winds under 5 kts, went with the vrb for overnight winds.
/OUTLOOK FOR KMSP/
TUE...VFR. Winds NW 10G20 kts.
WED...VFR. Winds NW 10-15 kts.
THU...VFR. Winds SE 5-10kts.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...None.
WI...None.
&&
$$
DISCUSSION...BPH
AVIATION...MPG
Area Forecast Discussion...UPDATED
National Weather Service Pittsburgh PA
915 PM EDT Sun Jun 11 2023
.SYNOPSIS...
Rain chances finally return to the area through Monday morning.
A cold front on Monday will usher in cooler temperature for the
first half of the week.
&&
.NEAR TERM /THROUGH MONDAY/...
A brief respite from rain/showers is spreading across ern OH and
into SW PA as precipitation shifts toward the north and
reorients across the Cleveland-Erie corridor.
Showers and storms along an advancing cold front will spread ewd
late this evening into ern OH and across the remainder of the
region overnight into Mon morning, providing a wetting rain to
all areas.
Updates to the forecast were made to reflect current wx and
expected timing and evolution, which depicts a slightly quicker
departure of precipitation on Mon morning than prior forecast
and a couple hours faster (but in similar evolution) to 22Z RAP
model, which handles the general rain footprint well.
General QPF depictions feature 0.3-0.5 inch for much of SW PA
and WV, 0.5-0.8 inch for much of NW PA, and 0.5-1.25 inch for
much of ern OH (ZZV observed over 0.75 in from just the
afternoon rain!).
Previous discussion follows...
Showers and isolated thunderstorms will arrive in waves through
the overnight as the system progresses eastward. Heaviest
(relatively) rain for most will occur after midnight. The cold
front will cross into western PA around 12z Monday, with showers
tapering off shortly thereafter. Monday afternoon should be dry
for most, outside of a lingering shower or two in the
ridges/higher elevations.
Today`s model runs have continued the overnight trend of keeping
higher QPF amounts farther west. The latest blend keeps roughly
1/4 inch to 1/2 inch for much of the area with around 3/4 inch
in NE parts of the forecast area. Slightly higher amounts will
be possible with any isolated thunderstorms, but this is
unlikely to be a drought buster.
Warm advection, rain, and cloud cover will keep overnight lows
in the upper 50s and lower 60s. Post cold front, Monday`s high
temperatures will be 5-10 degrees below normal (60s to near
70F).
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
With clearing sky and cold advection, lows Monday night will
fall 5-10 degrees below average.
The closed upper low over the Great Lakes will make little
eastward progress Monday into Tuesday. By Tuesday morning,
rainfall will rotate around the backside of this low and into
the Ohio Valley, eventually reaching the Pittsburgh area by
Tuesday afternoon/evening, and continuing into the overnight.
These showers will linger over the area through at least the
first half of Wednesday until the upper low finally shifts east
into southern Quebec/New York.
Cooler temperatures will continue on Tuesday and Wednesday with
similar temperatures to Monday.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
Models have come into a better consensus with later week
progression of the upper low across southern Quebec/the
Northeast. The low will quicken pace Wednesday night through
Thursday as it rides into the Canadian Maritimes. Meanwhile
several shortwave troughs will round the upper flow, elongating
the trough/opening low and returning chances for scattered
showers/thunderstorms to the area on Thursday and again (though
more isolated, lower chances) on Friday.
Saturday will at least initially be dry, but there remains some
disagreement with how quickly another shortwave will influence
rain chances over the weekend. Have kept closely to NBM PoPs for
this period, which gives Chc to SChc PoPs Saturday after and
overnight.
Temperatures will trend warmer for the second half of the week,
which will bump us to near average for highs (70s/80s) and just
below average for lows (40s/50s).
&&
.AVIATION /01Z MONDAY THROUGH FRIDAY/...
Initial band of much-needed light rain, some of it related with
a dying mesoscale convective vortex, continues to lift
northeastward across the region. Ceilings remain VFR, but MVFR
visibility is being seen in the rain at times.
A break of a few hours is expected, with ongoing VFR conditions,
although ceilings will begin to lower as the lower levels
continue to moisten. The next round of rain will arrive from the
southwest after 03Z and cross the region overnight. Expect most
of the thunderstorms with this to fade before arrival, although
a rumble or two can`t be ruled out at ZZV, and have maintained a
brief period of VCTS there. As rain moves in overnight,
ceilings will eventually drop to MVFR and then IFR levels at
most terminals. Confidence in IFR ceilings is a little less east
of PIT, where saturation may not be as thorough, but did end up
forecasting those levels.
Cold frontal passage late tonight/Monday morning will allow
showers to taper from west to east, and ceilings will also show
slow improvement through the late morning and the afternoon. VFR
ceilings may be achieved at most terminals by 00Z Tuesday.
.OUTLOOK...
Restrictions are possible again Tue through Thu in scattered
showers under an upper trough.
&&
.CLIMATE...
The dry streak has ended at Pittsburgh, Zanesville, New
Philadelphia, and Wheeling at 21 days with the rain that fell
today. Morgantown has not seen rain yet today, but rain is very
likely there overnight.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
PA...None.
OH...None.
WV...None.
&&
$$
SYNOPSIS...Kramar
NEAR TERM...Kramar/Rackley
SHORT TERM...Rackley
LONG TERM...Rackley
AVIATION...CL
CLIMATE...CL
Area Forecast Discussion
National Weather Service Pocatello ID
120 PM MDT Sun Jun 11 2023
.SHORT TERM...Today through Monday Night.
As an area of low pressure moves onshore to SRN California working
NE into the Great Basin, moisture will continue to advect north
keeping chances for showers and thunderstorms going into early next
week. With 0 to 6 km shear remaining less than 30 kts today, storms
will be slow moving and with PWATs between 120 and 180 percent of
normal or around 0.75 to 1.00 inch sitting above the 90th percentile
for this time of year, this will support a localized flash flooding
potential associated with locally heavy downpours. This is outlined
well in the WPC ERO which has a marginal risk over SE Idaho today
through Tuesday. The WPC has also issued a MPD for the CNTRL
Mountains and ERN/SRN Highlands for this afternoon in anticipation
of slow moving thunderstorms and saturated soils leading to
increased flash flooding risk. Thunderstorms today will initially be
confined to the higher elevations through the early afternoon hours
shifting out onto the Snake Plain later in the afternoon. The HRRR
model shows a line of thunderstorms working up out of Utah early
this evening with wind gusts up to 50 mph with thunderstorm
outflow winds outside of this line remain less than 35 mph.
Showers will become increasingly isolated overnight as drier
conditions prevail.
For Monday, the aforementioned low will be centered over the Great
Basin leading to even even better moisture transport north into SE
Idaho with scattered to numerous thunderstorms expected peaking in
intensity and coverage during the afternoon and evening hours.
Working with another limited 0 to 6 km shear environment, storms
will again be slow moving in nature conducive for locally heavy rain
and the potential for flash flooding. Small hail and outflow winds
up to 35 kts will be possible for Monday with the main hazard
centering around locally heavy rain especially in basins that are
already running high. Precipiation chances will continue into early
Tuesday morning becoming increasingly isolated. Afternoon highs
Monday will be slightly cooler with increased cloud cover regionwide
with elevated dew points keeping overnight lows moderate in the 40s
and 50s outside of coldest mountain basins. MacKay
.LONG TERM...Tuesday through next Sunday.
Tuesday is aiming to be another wet and stormy day here in
central and eastern Idaho. In fact, there is yet another MARGINAL
RISK of excessive rainfall for all of our area. Probability
forecasts show a 20-30% of over 0.50" across portions of the
central mountains, the Big Holes, southeast highlands, and the
South Hills/Albion Mountains. It looks like that wave of moisture
gets pushed east Wednesday, with gusty winds in its wake over the
western half of our forecast area. WPC has the eastern half
highlighted in another MARGINAL RISK for excessive rainfall.
Beyond that, the pattern becomes split flow with a low cutting off
over California and we are under the northern end of the split in
northwest flow. The GFS, ECMWF and Blend of Models is trending
down quite a bit for rain and storm chances Thursday into
Friday...although not necessarily zero over higher elevations. The
overall risk of heavier rainfall is trending way down though
during that period. Beyond that, we have another low that drops
into the northwestern U.S., that brings back the chance of heavier
rainfall and thunderstorms by the weekend to central and eastern
Idaho. Keyes
&&
.AVIATION...For the 18Z TAFS through 18Z Monday.
Showers and thunderstorms will continue daily with VFR conditions
overall. If and when a storm impacts a particular airport, look
for conditions reduced to MVFR/IFR due to heavier rain. Gusts over
30kts are not out of the question along with smaller sized hail.
Keyes
&&
.HYDROLOGY...
Flooding continues on several rivers including the Big Wood at
Hailey, the Big Lost at Howell Ranch, Antelope Creek north of
Arco, the Big Lost below the Mackay Reservoir, the Big Lost near
Arco, the Portneuf at Pocatello and Topaz and the Bear River at
the Wyoming border. The Big Lost River below Mackay Reservoir is
currently under a flood warning as well. The Big Lost near Arco is
under a flood advisory.
All these sites are running above normal due to high mountain snow
melt and recent moderate to heavy rainfall. Additional rainfall will
push all these rivers (and others) higher than current flows. All or
portions of central and eastern Idaho are under a MARGINAL RISK of
excessive rainfall through midweek. The forecasts are trending
toward lower chances of rain, especially heavy rainfall, for the
latter part of the week and into next weekend. Keyes
&&
.PIH WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
Area Forecast Discussion
National Weather Service Pueblo CO
847 PM MDT Sun Jun 11 2023
.UPDATE...
Issued at 839 PM MDT Sun Jun 11 2023
Current plan is to let severe thunderstorm watch 267 expire on
schedule at 9 pm. Discussed with SPC the potential for a new
watch including extreme southern portions of the southeast plains,
but at this point, appears supercell risk will stay mainly south
of the CO/NM and CO/OK borders, so new svr watch will stay in
NM/OK/TX overnight. Will keep Flash Flood Watch going for at least
a few more hours in El Paso/Teller Counties, as HRRR and various
other CAMs continue to generate waves of convection moving
northward through the area overnight, though heaviest rain has so
far stayed mainly north of the Palmer Divide.
&&
.SHORT TERM...(This evening through Monday)
Issued at 250 PM MDT Sun Jun 11 2023
Key messages
1) Severe storms continue this evening.
2) Threat for heavy rain especially El Paso County this evening.
3) Continued heavy rain and severe threat Monday.
.Currently...Stratocumulus deck has over portions of the eastern
plains has complicated the forecast. Severe storms are currently
occuring over Las Animas County south of the cloud deck. Further
to the north, the stratocumulus deck has help limit the daytime
heating while further north the cloud deck has been thinner near
the Palmer Divide. Some severe storms are developing just north
of El Paso County.
.Tonight...Tricky forecast for severe weather. Severe storms will
continue over the southern portions of the plains in the clearer
area. As shortwave approaches, there are signs for the potential
of a severe storm near the crest of the Palmer Divide and
northward where there has been less cloud cover. Cloud over will
limit the development of convection into the early evening in the
region in between. However, there is plenty of shear so if a storm
could get going, it can become severe. The threat transitions
later in the evening to heavy rain. Flow on the plains becomes
more southeasterly which orographically favors heavy rain over El
Paso County and the eastern parts of Teller County. High
resolution models show a band of showers and thunderstorms
developing later in the evening over the I25 corridor and moving
eastward, which the heaviest rain over northern El Paso County.
.Monday...Similar pattern to today with another disturbance
moving over the area during the afternoon and abundant low level
moisture from the eastern mountains and eastward. Model fields
suggest less instability than today, but still enough instability
for a SPC marginal outlook. WPC Day 2 heavy rain guidance has a
slight risk for much of the eastern plains. Subtle features will
determine the location of storms and heavy rain. Consensus from
the high resolution guidance suggests the greatest threat will be
along and north of US 50, expanding southward closer to the
Kansas border. Elsewhere, drier mid level air over the Continental
Divide region and high valleys will tend to limit rainfall with
any storms.
.LONG TERM...(Monday night through Sunday)
Issued at 250 PM MDT Sun Jun 11 2023
.Tuesday...Upper trough meanders around eastern Colorado during
the day. With low level moisture continuing on the plains,
anticipate another day with showers and thunderstorms. Tough to
be very specific with a weak system slowly moving over the
region. Current guidance suggest the higher QPF will be over the
northern portions of the CWA.
.Wednesday through Sunday...The weather pattern changes with he
operational models and ensemble means showing a trough moving
across the northern Rockies with westerly flow developing. With
the tendency for a lee trough to develop, ensemble means show
precipitable water decreasing, especially from the eastern
mountains and eastward, resulting in a drier weather pattern.
--PGW--
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 250 PM MDT Sun Jun 11 2023
KALS...VFR with higher based showers and thunderstorms early into
Sunday evening and Monday afternoon.
KCOS and KPUB...Showers and thunderstorms are possible Sunday
evening and into the overnight period. There is the potential for
some heavier rain over KCOS. Flight conditions could lower in the
heavier showers and thunderstorms. Lower clouds and fog are
possible overnight. Showers and thunderstorms are likely Monday
during the afternoon. --PGW--
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
Flood Watch until 3 AM MDT Monday for COZ081-082-084-085.
&&
$$
UPDATE...PETERSEN
SHORT TERM...PGW
LONG TERM...PGW
AVIATION...PGW
Area Forecast Discussion
National Weather Service Raleigh NC
922 PM EDT Sun Jun 11 2023
.SYNOPSIS...
A cold front will approach from the west tonight, then move through
the area Monday through Monday night, before settling just to our
south on Tuesday.
&&
.NEAR TERM /THROUGH TONIGHT/...
As of 920 PM Sunday...
The warm front slowly moving north across NC is fading as it moves
into more stable and drier air. Expect the area of stratiform rain
currently over the Coastal Plain, to dissipate as they move
northeast out of the area. Central NC will have a short lull in
precipitation before the approaching cold front moves into the
region later tonight and early Monday morning. Latest Hi-Res model
guidance has the stronger of the storms weakening as they move into
the Triad region late tonight and by the time this round of storms
move across the Triangle region, they will be more isolated to
scattered. Lows tonight expected to be a few degrees warmer than the
past few nights due to the warm air advection with a range of 65 NW
to 70 SE.
Previous Discussion as of 305 PM Sunday...
The warm front has inched to just southwest of our southern Piedmont
this afternoon, noted by a sharp gradient in sfc dewpoints (upper
50s/lower 60s in our area; upper 60s as close as KCLT). As such,
showers and storms have mostly focused to our south and west thus
far today along this boundary (also where PWAT is highest). As
expected, dew points have mixed out nicely into the lower to mid 50s
across our entire area. Consequently, conditions have remained
rather stable here locally. As this initial upper wave and the
aforementioned warm front move northeastward, there will likely be
enough moisture/instability to promote scattered showers/storms for
our western zones the next few hours. However, as this activity
propagates eastward, it should wane with time and spatial extent
given the already present stable conditions and loss of daytime
heating.
An additional upper wave is still expected to progress through
eastern TN/NC higher terrain late tonight/early Monday morning.
CAMs, while not in total agreement, do generally continue to
simulate quasi-linear storm clusters reaching the mountains late
tonight. Overall, they do tend to dissipate this convection as it
progresses through the foothills and into our western zones early
Monday morning. Other than perhaps a few isolated storms, overall
think that this conceptually makes sense given weak instability
expected overnight. While POPs will remain highest over western
zones overnight, anywhere across central NC could see an isolated
shower or storm tonight as PWAT surges to ~1.5 inches. Warm
overnight lows in the mid to upper 60s are expected tonight.
&&
.SHORT TERM /MONDAY AND MONDAY NIGHT/...
As of 305 PM Sunday...
Widely scattered/disorganized showers associated with an
exiting upper wave will likely be ongoing across the
Piedmont/Sandhills early Monday morning. Behind this initial wave,
additional upper energy embedded within an eastward ejecting short
wave over the deep south will push through our area Monday
afternoon. Lift associated with this upper feature, as well as
along a developed sfc boundary/cold pool should re-generate
scattered pre-frontal showers and storms Monday afternoon/evening.
These showers and storms will push east of the area between 00 and
03Z as a cold front sweeps through our area late Monday
afternoon/early evening.
There appears to be some consensus amongst the latest CAM guidance
that there could be a general lull in precipitation mid to late
Monday morning (although last few runs of the HRRR has been a bit
more active in this period). However, sfc dewpoints are expected to
surge into the upper 60s/lower 70s by early Monday afternoon which
may support the arrival of MLCAPE of up to 1500 J/kg (highest for
those along and east of US-1). This, in conjunction with the
aforementioned upper/sfc forcing should re-generate scattered
showers and storms Monday afternoon. However, there does remain some
uncertainty with respect to how much of that instability will
actually be realized given expected cloud cover (some CAMs only
generate precip to our east). But overall, think there is enough
evidence to support at least some re-generation of showers and
storms especially for those east of US-1 where insolation potential
will be strongest. While deep-layer shear still appears marginal (as
high as ~30 kts), a few storms could become strong to severe Monday
afternoon with the primary hazard being isolated damaging wind
and/or small hail. The better instability will be to our south in
South Carolina and to our east across the inner banks/coastal areas.
Thus, if any storms were to become severe, they would likely develop
over locations along and east of I-95. Locations west of US-1 should
see general improving conditions Monday afternoon as drying and
cooling occurs behind the advancing cold front. High temps will
range in the lower to mid 80s with a bit cooler overnight lows in
the upper 50s to lower 60s.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
As of 305 PM Sunday...
A circular closed low will be positioned over the Michigan thumb
with a vertically stacked occluded surface low at the surface Tues
morning. The trailing cold front from Mon convection will have
stalled across the Southeast stretching back into the lower/mid MS
Valley. The position of this front and associated deep layer
moisture to its south will be the primary focus for showers and Tues
evening into Wednesday. Current forecast has this front well south
of the area, featuring rain and some embedded elevated
showers/storms potential, mainly across the southern Piedmont into
the southern/central Coastal Plain. The better shot for more
appreciable precipitation comes Wednesday afternoon into early
Thursday as the remnant cold front hedges north briefly into the
eastern Sandhills and southern/central Coastal Plain ahead of the
next disturbance, which will overlap the frontal boundary and
sufficiently deep layer moisture to its south.
The finer details of the upper pattern begin to breakdown in
deterministic model guidance beyond Thursday. Ensemble guidance
highlights the persistent upper-trough over the Northeast begins to
flatten and move into the Canadian Maritimes Friday into Saturday,
leading to weak troughing to nearly zonal flow over the eastern
CONUS. Then, longwave ridging builds into the central CONUS Sat
night into Sun leading to the emergence of another Omega blocking
type pattern with a trough over the eastern seaboard and NW flow
directed through the Mid-Atlantic.
Temperatures throughout the extended will largely be tied to the
frontal boundaries position and the extent of precipitation and
cloud cover. For the most part expect a warming trend with
increasing humidity reaching near-normal by Thurs and above-normal
Friday into Saturday ahead of the next "cold" frontal passage.
&&
.AVIATION /00Z SUNDAY THROUGH FRIDAY/...
As of 710 PM Sunday...
24 hour TAF period: While showers have fallen at INT/GSO, and is
currently falling at FAY, the line is falling apart and it appears
that RDU/RWI should remain dry for the next several hours. There is
still high confidence that there will be enough low-level moisture
for IFR ceilings to develop at INT/GSO early Monday morning.
However, confidence is only enough to include scattered IFR clouds
at RDU/FAY and a passing TEMPO group at RWI around sunrise. As a
cold front approaches from the west Monday, think that there will
only be scattered showers at INT/GSO considering the late
morning/early afternoon timing, but have added prevailing showers at
other terminals with higher confidence that precipitation will occur
later in the afternoon. Thunderstorms are possible Monday afternoon,
with some storms possibly strong at RWI/FAY, but confidence was not
high enough to include a mention in the TAFs at this time.
Looking beyond 00Z Tuesday: Conditions should improve Monday
evening, although areas of sub-VFR may linger into Mon night over
eastern NC. VFR conditions should return behind the front for
Tuesday, but another chance of showers and storms will arrive
Wednesday into Thursday.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SYNOPSIS...BS
NEAR TERM...CA/Luchetti
SHORT TERM...Luchetti
LONG TERM...Swiggett
AVIATION...Green/BS
Area Forecast Discussion
National Weather Service Shreveport LA
949 PM CDT Sun Jun 11 2023
...New UPDATE, SHORT TERM...
.UPDATE...
Issued at 943 PM CDT Sun Jun 11 2023
Expanded evening pops a bit to line with radar current coverage.
&&
.SHORT TERM...
(Tonight through Monday Night)
Issued at 943 PM CDT Sun Jun 11 2023
The frontal boundary is a little more active now from Clarksville,
TX to near Hope, AR. Also convection in Texas is good to go for
several hours. HRRR is playing catch up even moreso than we are as
these storms will have life for hours. Some isolated maybe severe
with hail or gusty winds. We will continue to monitor this
development. No other changes at this time. /24/
&&
.LONG TERM...
(Tuesday through next Saturday)
Issued at 250 PM CDT Sun Jun 11 2023
An unsettled pattern will continue across our portion of the
country, at least through Wednesday with thunderstorms chances, some
of which could be strong to severe. The setup for this unsettled
pattern is the same one we`ve been dealing with for close to two
weeks. An anchored, closed upper level trough across the Great Lakes
into New England with a flat ridge across Mexico and into portions
of the Tx Hill Country. This pattern continues to favor west
northwest flow aloft across the Middle Red River Valley which means
subtle disturbances embedded in this flow will encounter either
diurnal heating during the day, or will be fed by a nocturnal, low
level jet at night with the end result being scattered strong to
severe thunderstorms Tuesday and again possibly on Wednesday. SPC
has outlooked a Slight Risk for severe weather across nearly our
entire region Tuesday/Tuesday Night and given the above mentioned
flow this is certainly possible. In addition, the latest progs are
showing a disturbance moving out of the Lee of the Rockies and into
the Southern Plains late Wed/Wed Night with perhaps another threat
of strong to severe thunderstorms late in the day 4 period. These
thunderstorms chances through at least Wed will help to temper
temperatures somewhat, especially across our northern half.
By Thu into Fri...we begin to see upper ridging trying to build from
the south and west and as this occurs, precipitation chances become
less and less and temperatures should start to climb. For the past
several days, the NBM has appeared to show a warm bias with
temperatures for late this week into next weekend as heights and
thickness values do not quite support widespread triple digit heat.
For that reason, have continued the trend of undercutting NBM Max
temps a few degrees beginning Thu and continuing through the
upcoming weekend. What models are in agreement with is the above
mentioned ridge will continue building north and east into our
region and just beyond the 7 day forecast period, the upper ridge
will likely be anchored across the Southern Plains/Lower Miss Valley
and the triple digit heat will likely be here for sure by then.
13
&&
.AVIATION...
(00Z TAFS)
Issued at 701 PM CDT Sun Jun 11 2023
For the ArkLaTex terminals, VFR this eve, but TS expected 03-09Z
w/ a little midlvl disturbance. Already firing TS S of KDAL/KRBD
and movg E. Will amend our VCTS sites w/ tempo groups for an
hr/two as we go. Otherwise, this may be all we see this cycle.
Look for IFR/MVFR 09-13Z cigs/vsby issues around daybreak. Then
VFR w/ varying winds across the area. SW winds will slack and
veer around to N/NE overnight behind impulse, & keep NE 5-15KT
for Mon. Lots more TS this week aftn/eve esp, but some nocturnal.
/24/
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 73 89 72 92 / 20 40 30 30
MLU 71 87 70 91 / 30 40 40 40
DEQ 66 82 66 83 / 20 40 70 60
TXK 70 84 69 88 / 30 40 70 60
ELD 66 82 66 87 / 30 40 70 60
TYR 72 91 72 92 / 20 30 20 20
GGG 71 91 71 92 / 20 40 30 30
LFK 73 95 73 95 / 20 10 10 10
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...None.
LA...None.
OK...None.
TX...None.
&&
$$
SHORT TERM...24
LONG TERM....13
AVIATION...24
Area Forecast Discussion
National Weather Service Tallahassee FL
910 PM EDT Sun Jun 11 2023
...New UPDATE...
.UPDATE...
Issued at 901 PM EDT Sun Jun 11 2023
Biggest challenge tonight is whether or not convection over North
Mississippi will make it into out area towards dawn Monday
morning. CAMs are slowly coming around to that solution with a
line of convection making it to our Southeast Alabama counties
around 10Z. Trends should be weakening with southern movement
through 12-14Z if it does make it into our area. Winds would be
the main threat.
&&
.NEAR TERM...
(Through Monday)
Issued at 447 PM EDT Sun Jun 11 2023
Flow aloft has backed to southwest flow courtesy of a potent UA
shortwave nearing the TN Valley this aftn, which is south of an UA
Low near the Upper Great Lakes Region. These synoptic features is
the focus for SPC Enhanced Risk centered over the TN Valley, but
locally is the reasoning behind the Marginal and Slight Risks
painted across the northwestern CWA today.
Isolated showers and thunderstorms have developed across portions of
the CWA as a result of persistent srly flow promoting moist low
levels (dewpoints in the upper 60s to lower 70s) and daytime
destabilization, thus typical for this time of year. MUCAPE of 2000
J/kg coupled with DCAPE values of 700-900 J/kg and PWATS aoa 1.6
inches suggests these storms will pose a risk for gusty winds and
localized moderate rainfall. Mean-flow of 15 kts will aid to
mitigate significant flooding potential, though water ponding along
poor-drainage areas is still a possibility. Similar to yesterday,
should see this activity diminish throughout the evening hours.
Focus will shift to the aforementioned UA shortwave and its
associated sfc low that will traverse towards the Ohio Valley this
evening into tonight. A few model solutions and high-res solutions
hint at the tail-end of the sfc low associated with a cold front and
embedded line of storms, to near portions of southeast AL and
southern/southwestern GA. Uncertainty exists in regards to whether
the activity will hold together as it approaches the area late
tonight/early tomorrow morning. If it does hold together, and the
nearby UA shortwave maintains its strong mid-upper level flow, it
could pose a wind and hail threat. In addition, if storms are able
to hold together, and gusty winds occur, widespread fog overnight
may prove difficult to materialize.
Tomorrow, flow aloft will commence to veer to the west-southwest,
whilst the cold front stalls across the northern zones. This could
become a focus for storm development by the aftn hours. Model
solutions depict an adequate mid-upper level jet max moving across
the area, hence the SPC Risk of Marginal (with a sliver of Slight
Risk across the far western notes) painted for the CWA. Gusty winds
and hail appear to be the main threats attm.
Otherwise, overnight lows in the 70s and highs in the upper 80s to
lower 90s for tomorrow is expected.
&&
.SHORT TERM...
(Monday night through Tuesday night)
Issued at 447 PM EDT Sun Jun 11 2023
Convection from Monday afternoon should be on a diminishing trend
after sunset from the loss of daytime heating/instability. However,
this quieter weather will be short-lived as another round of
scattered showers/storms redevelops across the service area on
Tuesday. Activity is going to be aided by mid-June daytime
instability, a nearby surface frontal boundary, and upper-level
support via embedded impulses rounding the base of a large parent
trough over the Great Lakes. This pattern is an atypical summertime
set-up consisting of favorable and overlapping parameters for strong
to severe thunderstorms. The "wow factor" is the unseasonably strong
flow aloft fostering deep-layer shear around 30 kts! Afternoon
modeled soundings for KTLH depict Inverted-V profiles, high DCAPE
(1000-1100 J/kg), and mid-level lapse rates near 7 C/km. Although
storm mode is a bit uncertain, multi-cellular clusters and semi-
organized lines are reasonable assumptions as shown by the 18Z HRRR
and 12Z GFS FV-3.
Currently, only a sliver of a Marginal Risk (level 1 of 5) by the
SPC in the Day 3 Outlook clips the extreme NW corner of our CWA, but
it would not be surprising to see a future eastward expansion if
trends hold. The main threats would be damaging wind gusts and hail.
Secondary threats are frequent lightning and pockets of heavy
rainfall. Outside of the storminess, it will be hot and humid.
Forecast highs range from the upper 80s to low 90s. However, the
high humidity pushes heat indices from mid 90s to low 100s. Muggy
overnight conditions are expected when lows fall into the sultry low
70s away from the immediate coast.
&&
.LONG TERM...
(Wednesday through Saturday)
Issued at 447 PM EDT Sun Jun 11 2023
We still continue to see very robust signals towards a concerning
stormy pattern that unfolds/escalates beginning on Wednesday. The
mean upper trough begins drifting from the Great Lakes towards the
NE US with additional impulses streaming through the region while
ridging anchors itself over TX/northern Mexico. Northwest flow aloft
becomes established with an attendant frontal boundary to our north.
The airmass is expected to remain seasonably unstable and moist, but
anomalously sheared (30-35 kts at 0-6 km). In fact, a low-level jet
(LLJ) appears to overspread the service area at the start of this
period. Models have picked up on this development by being bullish
on sustained inland, non-convective winds ranging from 15 to around
20 kts during the afternoon. The presence of such a LLJ would surely
enhanced the strong/damaging wind potential from thunderstorms, so
that will be something to watch going forward.
Additional rounds of robust thunderstorms are likely through the
work week thanks to the aforementioned ridge and trough continuing
to funnel in all these upper impulses towards us via the dreaded
northwest flow (for this time of year). As such, we may potentially
see multiple Mesoscale Convective Systems (MCSs) during this period.
An MCS is notorious for being hard to forecast, long-lived, and
posing a damaging wind and heavy rainfall threat. Wind is more
concerning given the Severe Downburst Threat Assessment by the SREF
and GEFS show high probabilities of overlapping parameters.
Ridging builds in from the west/southwest this weekend, which should
hopefully allow us to revert to more of the typical summertime
pattern. Forecast high temperatures range from the upper 80s to
low 90s with triple digit heat indices, especially Saturday-
Sunday. Muggy overnight lows in the low to mid 70s will be common.
&&
.AVIATION...
(00Z TAFS)
Issued at 731 PM EDT Sun Jun 11 2023
Convection will be slow to dissipate over the next several hours
with isolated coverage into the mid evening. Overnight, a few CAMs
bring convection back into our northern locations in the pre dawn
hours and have a prob30 group at DHN/ABY for this possibility,
along with MVFR cigs and vsbys. If this occurs, models show
weakening trend through 14Z. Beyond this, expect southwesterly
gusts 18-20 knots after 16Z at most sites with more convection
developing towards the afternoon hours. Highest possibilities at
DHN/ABY and less at the other sites.
&&
.MARINE...
Issued at 447 PM EDT Sun Jun 11 2023
Southwest winds prevail through the work week with generally
favorable boating the next couple days outside of thunderstorms.
A stormy pattern likely arrives by Wednesday with prevailing winds
increasing to cautionary levels, especially over nearshore Apalachee
Bay where gusts in excess of 25 knots are possible.
Strong convective gusts and lightning will be the main concern
heading into the weekend.
&&
.FIRE WEATHER...
Issued at 447 PM EDT Sun Jun 11 2023
A moist airmass precludes fire weather concerns outside of
gusty/erratic winds and lightning from thunderstorms. However,
strong to severe convection is likely, beginning perhaps as soon as
early tomorrow morning from a decaying storm cluster sagging through
SE AL and perhaps the FL Panhandle. Another round of storminess then
encompasses much of the Tri-state area by the afternoon. Otherwise,
high dispersions are forecast across the I-10 corridor and Wiregrass
Region Monday. Widespread wetting rain potential is high as well.
Wednesday is shaping up to be very active, but details are a bit
uncertain at this time. Regardless, prepare for unsettled weather
until at least this weekend. Lastly, the combination of high
relative humidity and hot temperatures will make for heat indices
ranging from the mid 90s to low 100s.
&&
.HYDROLOGY...
Issued at 447 PM EDT Sun Jun 11 2023
Wetter weather is forecast over the next several days as multiple
rounds of showers and thunderstorms with pockets of heavy rainfall
are expected through the work week. Projected amounts are about 1-5"
from south to north (isolated higher). As such, flooding may be a
concern, especially north of I-10 where a Marginal Risk (level 1 of
4) exists in the Day 3-5 Outlook by the WPC. All area rivers are
currently in good shape, but we could see some rises going
forward.
&&
.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 73 92 74 92 / 10 50 30 50
Panama City 76 86 77 87 / 20 30 30 30
Dothan 72 91 70 89 / 40 60 30 60
Albany 71 91 71 89 / 40 60 30 60
Valdosta 71 92 73 92 / 10 60 30 50
Cross City 71 89 73 90 / 10 20 10 30
Apalachicola 76 86 78 85 / 10 20 10 30
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
FL...None.
GA...None.
AL...None.
GM...None.
&&
$$
NEAR TERM...Bowser
SHORT TERM...IG3
LONG TERM....IG3
AVIATION...Scholl
MARINE...IG3
FIRE WEATHER...IG3
HYDROLOGY...IG3
Area Forecast Discussion
National Weather Service Las Vegas NV
130 PM PDT Sun Jun 11 2023
.SYNOPSIS...An incoming weather system will bring widespread
shower and thunderstorm activity to the region through Monday with
decreasing coverage Tuesday and Wednesday. Temperatures will cool
markedly as well through Monday before gradually returning to near
normal by the end of next week.
&&
.SHORT TERM...through Monday night.
Scattered showers and thunderstorms have become fairly widespread
across portions of southern Nevada and southeast California as a
unseasonably cold area of low pressure moves inland over southern
California. Storms have generally been firing north of the I-15 and
drifting west and have been producing pockets of heavy rain. With
cold mid level temperatures ranging about -14C to -16C we have had
several reports of small hail associated with some of the stronger
storms. We will continue to see showers and storms develop through
this afternoon as the upper low slowly drifts east. With the
associated dynamics of the low, it is unlikely that we will
completely end the showers and thunderstorms with loss of daytime
heating and the latest HRRR shows convection developing after
midnight over southern Nevada. We can expect to see another day of
scattered showers and thunderstorms Monday as the low slowly shifts
east. The low will be a slow mover and is forecast to be centered
closer to the Nevada, Utah, and Arizona borders Monday morning. This
will allow for another day of scattered showers and thunderstorms
throughout the day with some storms producing localized heavy rain
and small hail. Outside of the storm chances the next few days,
temperatures will remain well below normal with the widespread
clouds and shower activity expected.
.LONG TERM...Tuesday through Sunday.
By Tuesday, the upper low which brought precip chances and
unseasonably mild temperatures should be shearing apart, with one
piece moving away to the east and the other retrograding to the
southwest. There is quite a bit of model spread in the position
and track of the low that retrogrades back over the eastern
Pacific, with some solutions leaving it well offshore and others
showing it drifting back inland during the period. Thus,
confidence is moderate at best. This forecast assumes that the low
will remain southwest of our area, which will allow precip
chances to retreat to the northern third or so of our CWA, and
also kick start a warming trend as heights rise in response to
high pressure over Mexico bulging northwest in between the two
lows. If this solution pans out, expect a dry late week and
weekend, with increasing chances for KLAS finally reaching 100F
for the first time of the year. On the other hand, if the low
drifts back inland, warming would be suppressed and chances for
showers and thunderstorms would increase.
&&
.AVIATION...For Harry Reid...Showers and thunderstorms will be
fairly widespread this afternoon generally west and north of the Las
Vegas Valley, however there are indications that the potential of
thunderstorms developing closer to the Valley after 21-22Z and will
need to be closely watched. Winds will generally remain southeast 10-
20kts, but could become variable and gusty at times with any
potential outflow boundaries. There is also some potential of seeing
convection during the overnight period along with varying gusty
winds, although confidence is low at this point. Similar conditions
expected Monday with scattered afternoon showers and thunderstorms
around southern Nevada along with general southeast winds, but could
become erratic and gusty near thunderstorms.
For the rest of southern Nevada, northwest Arizona and southeast
California...Scattered showers and thunderstorms will impact most
TAF sites this afternoon along with the potential of gusty outflow
winds up to 30kts. At this time, KDAG will have the lowest chance of
seeing additional thunderstorms this afternoon and evening. Winds
will generally southeast to south with speeds generally 10-20kts.
Another round of showers and thunderstorms will occur again Monday
with the potential of impacts at each TAF site, especially gusty
winds.
&&
.SPOTTER INFORMATION STATEMENT...Spotters are encouraged to report
any significant weather or impacts according to standard operating
procedures.
&&
$$
SHORT TERM...Gorelow
LONG TERM...Morgan
AVIATION...Gorelow
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