Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 07/16/22
AREA FORECAST DISCUSSION
National Weather Service Wakefield VA
928 PM EDT Fri Jul 15 2022
.SYNOPSIS...
A weak frontal boundary meander northward across the region.
Expect shower and thunderstorm chances to persist each day, with
the best chances being along and southeast of the frontal
boundary. More diurnally driven showers or storms will be
possible late this weekend into early next week.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
As of 920 PM EDT Friday...
Mainly diurnally driven convection
has diminished greatly over the past hour or two. Still, some
convection is persisting over NE NE near the Albemarle Sound
likely pinned to a boundary from earlier convection. However,
trends with this convection is also diminishing and the
expectation is that thunderstorm activity should end by
midnight. This will leave perhaps some isolated showers across
the SE overnight.
With all of the precipitation today, and clearing skies from the
west along with light winds, am expecting fog to develop across
much of the area tonight. Have introduced fog across the entire
area. There are hints from the RAP that the fog could become
dense overnight but for now will simply include patchy fog in
the forecast.
As of 355 PM EDT Friday...
Convection fired along a slow-moving boundary across the central
CWA. Along and to the south of this front, 1000-1500 MLCAPE and
effective shear of 20-30 kts will result in loosely organized storms
capable of strong to severe wind gusts as the taller cores collapse.
PW values range from 1.25" near RIC to nearly 2" near the Albemarle
Sound, so showers and storms this afternoon will continue to produce
locally heavy rainfall with localized areas of flash flooding
possible, especially in urban and poor drainage areas. CAM guidance
shows the relative greatest coverage of showers/storms along the I-
95 corridor south of Richmond and to the southwest of the ongoing
storms over the lower peninsula/Hampton Roads. A mid level cloud
deck left over from showers this morning has hampered heating
somewhat over far SE VA and NE NC but given further heating and
aforementioned deep moisture, storms are possible just about
anywhere across the southeastern half of the area into this evening.
Convection wanes quickly after sunset with the loss of heating. Some
patchy fog is possible late tonight. Lows temps fall into the mid
and upper 60s.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY NIGHT/...
As of 355 PM EDT Friday...
General troughing is maintained across the NE portion of the CONUS
with strong upper ridging holding strong over the SW. Bermuda high
off the SE coast will be a quasi-permanent feature this weekend into
next week. A stationary front will slowly move north this weekend,
acting as a focus for development of afternoon/evening showers and
storms. Deep layer wind shear will be seasonally weak but
instability and copious moisture will result in some isolated
potential for strong wet microburst winds. Flow turns southerly on
Saturday as the front lifts slowly northward. A weak lee trough may
set up by late afternoon which will also serve as a focus for
convection. Showers and storms will linger into the evening with
diminishing chances for thunder, especially after midnight. High
temps Saturday warm into the mid and upper 80s. Muggy overnight with
lows in the mid to upper 60s inland to right around 70 near the
coast.
Similar conditions on Sunday with not much change in the local
airmass. Scattered afternoon showers and storms are favored over the
western and central portions of the area as weak lee troughing sets
up by the afternoon. Highs top out in the upper 80s and low 90s.
Lingering showers will end quickly Sunday evening with overnight
lows in the low 70s.
A touch warmer for Monday as Bermuda high pressure builds westward.
Low pressure near the Great Lakes moves eastward during the
afternoon and evening, bringing a cold front/surface trough toward
the area. This will focus the highest storm chances across the
northwest and northern parts of the area. Afternoon high temps in
the 90s with upper 80s near the coast.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
As of 355 PM EDT Friday...
Warming trend gets underway in the extended forecast period. Highs
temps in the low 90s on Tuesday with overnight lows in the 70s. The
heat looks to peak on Wednesday with temperatures in the mid 90s for
all but the immediate coast. Thankfully, dew points will tend to mix
out a few degrees each afternoon so heat indices peak below heat
advisory thresholds (105+). Shower and storm coverage also looks to
be rather sparse on Wednesday. Remaining hot Thursday with highs in
the low to mid 90s with slightly higher chances for showers and
storms by the afternoon. A degree or two cooler on Friday with highs
in the low 90s with diurnal shower and storm chances.
&&
.AVIATION /02Z SATURDAY THROUGH WEDNESDAY/...
As of 150 PM EDT Friday...
Showers and storms have mostly ended and will unlikely impact
the terminals tonight. However, with all of the rain from today,
combined with light winds and some partial clearing, fog is
expected overnight. Guidance is not very bullish on fog
development, however the numerical guidance suggests fog
overnight and have introduced MVFR fog at all of the terminals.
Will need to watch closely for IFR conditions and it is possible
that the 06z TAFs will need to include IFR conditions overnight.
VFR conditions expected tomorrow athough additional showers and
storms in the afternoon will allow for the possibility of flight
restrictions at all terminal locations.
Outlook: A typical summertime pattern remains in place into next
week, with additional isolated to scattered storms expected
mainly each afternoon and evening. Instances of early morning
fog and stratus will also be possible into early next week.
&&
.MARINE...
As of 305 PM EDT Friday...
A nearly stationary front lingers inland through Sat before lifting
north Sat night. This will allow for showers and storms this
afternoon into this evening and again tomorrow afternoon into the
evening. Even once this front moves out of the area, diurnal
afternoon and evening showers and storms will continue to be
possible through most of next week. Otherwise, typical summer
pattern with no significant FROPA expected over the next week and
sub-SCA conditions likely continuing through at least early Mon.
Winds this afternoon are generally SE 5-13 kt. Winds remain SSE/S
this evening through tonight, diminishing to 5-10 kt late. SE winds
5-10 kt early Sat increase to 10-15 kt late before becoming SW Sat
night. Winds slowly pick up Sun with the strongest winds arriving
late Mon through Mon night as S winds (becoming SW Mon night)
increase to around 15 kt across the bay and 15-20 kt across the
coastal waters. Will continue to monitor trends as we get closer as
SCAs may be needed for this surge. The next potential for SCAs is
late Wed through Thurs night as SW winds increase to 15-20 kt across
the Ches Bay and 18-20 kt with gusts to 25 kt across the coastal
waters. Waves and seas remain 1-2 ft and around 2 ft respectively
through Sun afternoon.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...None.
NC...None.
VA...None.
MARINE...None.
&&
$$
SYNOPSIS...AJB/RHR
NEAR TERM...RHR/MRD
SHORT TERM...RHR
LONG TERM...RHR
AVIATION...RHR/MRD
MARINE...RMM
Area Forecast Discussion...UPDATED
National Weather Service Amarillo TX
605 PM CDT Fri Jul 15 2022
.AVIATION...00Z TAF...
A very quiet TAF period is in store with VFR conditions
prevailing. Winds will be southeasterly to southwesterly generally
less than 15 kts. Skies will be mostly clear with maybe a few
high clouds.
Hoffeditz
&&
.PREV DISCUSSION... /Issued 136 PM CDT Fri Jul 15 2022/
SHORT TERM...This afternoon through tomorrow night...
Well above average high temperatures will continue through
tomorrow across the Texas and Oklahoma Panhandles. Widespread high
temperatures in the triple digits are forecast for this afternoon
and tomorrow afternoon. The short term will remain mostly dry,
however, a storm may be able to get into the far northwestern
Panhandles tomorrow evening.
The latest RAP upper air analysis early this afternoon shows the center
of the H500 high pressure system is currently located over
northeastern NM early this afternoon. Temperatures across the
Panhandles at the time of this writing, are ranging from the mid
90s in the southwest to just over 100 for most areas in the
north and east. Winds will remain relatively light this afternoon
and temperatures will rise into the triple digits for most areas.
Upper level high shifts a bit further east to just over some areas
of the Panhandles during the day tomorrow. Deterministic model
guidance suggests that the H850 temperatures will be comparable to
what they are today (32 to 35 C), so surface temperatures will be
comparable to what we experience today. Some areas will likely
need to be in Heat Advisory criteria, much like today. Palo Duro
Canyon is forecast to reach up to 108 tomorrow and will at least
reach advisory criteria once again. A subtle upper level
disturbance traversing around the high pressure aloft will move
across the higher terrain to the west tomorrow. A few
thunderstorms are expected to form in this area and may be able to
make it into the far northwestern Panhandles during the late
afternoon into evening hours.
Muscha
LONG TERM...
A weak cold front is expected slip southward across the Panhandles
on Sunday. This front may become a focus for showers and
thunderstorms, mainly across the southwest half of the CWA in the
afternoon and evening. This rain, if it develops, would bring at
least a brief relief from the heat.
It looks like Monday and Tuesday will be dry days for the most part
as the flow aloft remains northerly which will make it tough to
bring any mountain convection this way. There is an outside chance
that some showers and storms may make it into Cimarron County
Tuesday evening in association with another weak cold front.
Showers and thunderstorm chances are expected to increase a little
Wednesday and Thursday mainly for the western Panhandles. The flow
aloft becomes more northwesterly as the upper high moves back across
the 4-corners region. Also, there could be some weak upper level
disturbances in the flow that may help to bring the mountain
convection this way.
High temperatures will remain above normal from Sunday through
Thursday. Readings will be generally in the 95 to 105 range.
However, Tuesday still looks like the warmest day with readings from
around 100 degrees to 110 degrees.
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...Heat Advisory until 9 PM CDT this evening for Hansford-
Hutchinson-Moore-Palo Duro Canyon-Sherman.
Excessive Heat Watch from Saturday afternoon through Saturday
evening for Palo Duro Canyon.
OK...Heat Advisory until 9 PM CDT this evening for Texas.
&&
$$
36/5
Area Forecast Discussion
National Weather Service Bismarck ND
934 PM CDT Fri Jul 15 2022
.UPDATE...
Issued at 934 PM CDT Fri Jul 15 2022
At 02Z, convection remains in Montana, having weakened from
earlier central Montana activity. Over the past hour there has
been an uptick in intensity, especially along an outflow boundary
from Miles City to Glendive, though still sub-severe at the
moment. Better surface dew points remain on the North Dakota side,
which should contribute to a stronger reservoir of MUCAPE.
However the degree of convective inhibition remains uncertain,
especially as surface temperatures cool this evening. 01Z HRRR
seems to be picking up on the recent weaker trends, but keeps
convection going well into central North Dakota early Saturday
morning. Given the steep mid-level lapse rates sampled by the KBIS
RAOB, supply of surface dew points around 70 F, and possibility
of a LLJ overnight, it seems reasonable that strong thunderstorms
(but less certain to be severe) are still possible in western and
central North Dakota overnight.
UPDATE Issued at 636 PM CDT Fri Jul 15 2022
Current regional radar depicts clusters of thunderstorms moving
from central to eastern Montana, where severe wind and hail have
been reported. A few thunderstorms were ongoing in central
Saskatchewan, but well north of the International Border.
Thunderstorms will be more likely to arrive on the western North
Dakota border as the mid level shortwave and attendant surface
trough approach late this evening. Severe weather continues to be
possible, more likely along the western third of the state, where
the atmosphere should remain moderately unstable late this
evening with good deep layer shear. Hodograph orientation looks
to favor the northwest portion of the state, where generally
straight hodographs should lead to some rotating cells. In the
southwest, forecast hodographs exhibit backing with height in the
mid-levels, which leads to less confidence in organized severe
thunderstorms late tonight. That said, large dew point depressions
have allowed for even disorganized convection to produce severe
wind gusts in southeast Montana this evening, which may continue
into southwest North Dakota while the boundary layer is still
reasonably mixed. Therefore the severe risk should last longer in
the northwest to north central this evening and tonight where the
wind shear orientation is more favorable for organized cells, but
a shorter lived risk, especially for wind, does exist in the
southwest before the boundary layer completely decouples late this
evening.
The severe potential becomes likely in the central as MUCAPE and
shear decreases overnight, therefore the current outlook with
severe potential kept west and north central looks reasonable.
&&
.SHORT TERM...(This evening through Saturday)
Issued at 223 PM CDT Fri Jul 15 2022
The main concern in the short term period will be the chance of
thunderstorms, some possibly severe.
Afternoon radar mosaic shows showers and thunderstorms starting to
increase across parts of central Montana with some increase in
lightning activity over the past couple of hours. For tonight, it
appears there could be two potential scenarios to play out
according to the CAMS. Scenario 1, would be lead to more of a
supercell threat with an earlier onset time. Scenario 2, would
see convection coming out of Montana in clusters / lines with a
later onset time.
For now, we are learning more towards scenario 2 which lines up
better with the upper and low level forcing. We can also already
see signs of the convection in Montana forming while low clouds
are lingering in southern Saskatchewan with no convective
development as of this writing. The first scenario would lead to
a bigger hail threat, but for now will stay with half dollar size
hail and 70 mph winds since we are learning more towards scenario
2.
Overall, the current SPC Day 1 outlooks seems to cover things
well with the best environment for severe thunderstorms in the
western part of the state. That is where instability will linger
longer in conjunction with 40 kts of deep layer shear. The low
level jet will also be a little more pronounced in the western
part of the state this evening before decreasing overnight.
Convection could linger into Saturday morning, but overall the
trend should be for it to wane as the better upper level forcing
moves east. Later Saturday morning into the afternoon could easily
be dry, but there does appear to be a weak boundary left by the
morning convection, and it`s possible something could fire along
that. That being said, once the morning convection ends, most
CAMS are dry into the afternoon. Will go ahead and continue to
carry a slight chance pop into the afternoon in case something
tries to linger, or in case there is additional development later
in the day.
Outside of the thunderstorm chances, the other story will be the
heat. Morning thunderstorms should give way to partly to mostly
sunny skies with highs in the mid 80s to low 90s. Those
temperatures combined with dewpoints in the mid 60s will make for
a hot afternoon.
.LONG TERM...(Saturday night through Friday)
Issued at 223 PM CDT Fri Jul 15 2022
A chance of thunderstorms could linger into Saturday night, but
hot temperatures on Sunday will likely be the main story to end
the weekend. Looking at high temperatures on Sunday, NBM
percentiles show fairly high confidence in the hot temperatures,
with some locations potentially reaching near 100 degrees.
Currently dewpoints are expected to be a little lower on Sunday in
the west, which is where the hottest temperatures are forecast.
This generally keeps apparent temperatures in the upper 90s for
Sunday, though a few locations could definitely approach 100
degrees.
The upper ridge in place across the region then begins to get
knocked down a bit early next week as a series of waves move
across it. Medium range models are starting to show some agreement
that a stronger wave will move across Monday night into Tuesday,
which could trigger a more organized chance of thunderstorms. SPC
has already highlighted northern parts of the state for Monday.
Behind the wave / cold front, cooler temperatures are expected
for Tuesday, with seasonably warm temperatures then to end the
week. Tuesday could also be breezy / windy with the ECMWF EFI
still suggesting the potential for advisory level winds.
&&
.AVIATION...(For the 00Z TAFS through 00Z Saturday evening)
Issued at 636 PM CDT Fri Jul 15 2022
Showers and thunderstorms are expected to move through western and
central North Dakota late this evening through Saturday morning.
Best potential for impacts will be in the west, at KXWA-KDIK.
Coverage becomes less certain further east. Erratic gusty winds
and hail will be possible with thunderstorms tonight. Outside of
brief periods of reduced visibility and ceilings under
thunderstorms, VFR conditions expected through the 00Z TAF period.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AE
SHORT TERM...King
LONG TERM...King
AVIATION...AE
Area Forecast Discussion
National Weather Service Glasgow MT
730 PM MDT Fri Jul 15 2022
.DISCUSSION...
EVENING UPDATE: 0100Z
A quasi-cold front is moving west to east across the area and
leaving a narrow 40 mph wake behind it. Airmass thunderstorms
are briefly attempting to ride the boundary for about 20-30
minutes before crashing and then blowing up a new one ahead of
the old.
With this in mind have decided to update the hourly data of the
forecast for the next 9 hours to time the frontal boundary on
wind gusts and PoPs and found that the last two runs of the HRRR
are almost dead on target. They also worked rather well for Temps
and RH.
Looking forward we will also continue to monitor thunderstorms on
the boundary into the evening as brief gusts up to 50 to 65 mph
are possible with the largest of the cells when they collapse. GAH
AFTERNOON UPDATE (2200Z): No major updates to the forecast this
afternoon. Overall situation remains stable from previous
iterations.
Cliff
PREVIOUS DISCUSSION:
The primary focus of the forecast is on thunderstorm timing and
severe potential today, along with monitoring heat concerns this
weekend.
A slight risk of severe storms exists across much of the
county warning area for this afternoon and evening, with the main
threat being damaging winds. Capping will be a limiting factor,
but enough boundary layer mixing should occur for downdraft
potential by mid afternoon that also presents a modest hail
threat. Early afternoon development over the higher terrain of
central Montana is indicated by the convective allowing models, with
activity spreading east/northeast before exiting into North
Dakota late in the evening.
High temperatures should reach the mid to upper 90s both today
and tomorrow, likely falling just short of 100 due to some clouds
and low-level moisture advecting into the area. On Sunday, clear
skies and slightly lower dew points should lead to some near
record highs in the triple digits for some, though limiting the
severity of apparent temperatures a bit. Another Heat Advisory
looks all but certain, with borderline Excessive Heat Warning
conditions remaining possible.
By Monday, the ridge likely begins to break down with a cold
front looking to take the edge off the heat and bring the next
chance for showers/thunderstorms. Timing of the front and cloud
cover make Monday`s highs more uncertain than usual. Nevertheless,
more seasonably hot conditions with highs on either side of 90
into midweek seems reasonable given mostly zonal flow.
-Zanker
&&
.AVIATION...
LAST UPDATED: 0100Z
EXPECTED FLIGHT CAT: VFR to MVFR
DISCUSSION: Mainly VFR. Scattered thunderstorms will continue to
move east across the area and may impact KGDV and KSDY briefly.
MVFR visibility is possible with any direct hits through this
evening. Some storms may be severe with damaging winds being the
primary threat. Fair weather returns late tonight into Saturday.
Winds: Southeast winds becoming southwest today at 5-10 knots,
then light and variable overnight. Gusty winds due to passing
thunderstorms may impact the vicinity of KGDV or KSDY, so
amendments are possible. Main direction with thunderstorms is out
of the west around 35 kts.
GAH
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
weather.gov/glasgow
Area Forecast Discussion
National Weather Service Honolulu HI
410 PM HST Fri Jul 15 2022
.SYNOPSIS...
Locally strong trades will focus moisture associated with
decaying Tropical Cyclone Darby over Windward Big Island and Maui
where periods of heavy rain can be expected on Saturday.
Elsewhere, fairly typical trade wind weather can be expected.
Winds will decrease and conditions will improve by Sunday.
&&
.DISCUSSION...
The latest trend in the modeling and the most recent observations
has been a slight northward adjustment for Darby as it decays
while passing south of the Big Island on Saturday. While this
adjustment is not sufficient to change the overall flavor of the
event for the Big Island and Maui County, it did warrant an
upward nudge in forecast winds. Given the potential early-
Saturday start time of stronger trades for the windier areas on
these islands, bumped winds up a couple mph and issued a wind
advisory beginning at 6am Saturday morning. Additionally, with the
mid- level stable layer helping to accelerate winds over the
summits, a wind advisory was issued for Haleakala Summit and the
Big Island summits as well.
Forecast rainfall remains unchanged and something in the
neighborhood of 2-4" with local maxima up to 5" appears
reasonable for the Big Island. The HRRR still resides firmly on
the wetter end of the spectrum with its 18z run while the 18z GFS
made a noteworthy move toward the wetter end as well. This was
enough evidence to warrant shying away from this morning`s drier
hi-res runs. Given that these hi-res models are GFS-initialized,
it wouldn`t be entirely surprising if the next round of hi-res
guidance came in wetter than the morning runs.
Showers will begin over downslope portions of Windward Big Island
early Saturday and will expand upslope as deeper moisture
arrives. Low stability in the lowest 12-14kft should help maximize
the efficiency of orographic forcing, but ultimately mid-level
stability will limit higher end rainfall potential. The duration
of heavier rainfall on Windward Maui should limit totals there to
1-2" during the course of the day. Heavier rain will be possible
on a very localized basis as deep moisture advancing over the high
terrain during peak heating supports a chance for thunderstorms
over both windward and leeward zones.
Fairly typical trade wind weather will prevail for the remaining
islands throughout this time with breezy to locally strong trades
helping to offset the slight increase in humidity associated with
the incoming moist airmass. With upper ridging already in place,
the trade inversion should quickly reestablish on Sunday as
Darby`s moisture exits westward. This will support a quick return
to a breezy and stable trade wind pattern to begin next week.
&&
.AVIATION...
Breezy to locally strong trade winds will continue for the rest of
today and into the weekend as high pressure remains anchored well
north of the state. As a result, AIRMET Tango remains in effect
for moderate low level turbulence over and downwind of terrain for
all islands. This AIRMET will likely be needed for at least the
next few days.
Afternoon satellite imagery and surface observations show that the
band of enhanced showers and low clouds that moved into windward
sections of many of the main Hawaiian Islands has dissipated. VFR
flight conditions currently prevail at all area terminals, and
this is expected to continue into the evening for most locations.
Late tonight into Saturday, Tropical Storm Darby is forecast to
track westward and pass south of the Big Island as it weakens.
This will result in an increase of low clouds and showers across
the eastern end of the state. Prevailing MVFR with occasional IFR
conditions, mountain obscuration, and a slight chance of
thunderstorms will be possible for portions of the Big Island on
Saturday.
&&
.MARINE...
Tropical Storm Darby and is located roughly 430 miles east-
southeast of the Big Island this morning. This system has been
moving westward at about 17 kt. The Central Pacific Hurricane
Center`s latest forecast indicates Darby will continue to weaken,
and is expected to enter the southeast offshore waters late
tonight as a Tropical Storm. A Tropical Storm Warning is in effect
for the offshore waters.
A surface high pressure system will remain far north of the
islands through early next week. In the near-term, the trades
winds are expected to strengthen as Tropical Storm Darby moves
closer to the region. Depending on how close Darby passes to the
Big Island, Gale force winds are possible over the south waters of
the Big Island. In addition, combined seas will be elevated and
rough due to a combination of local wind waves, and large south
and east swells. A Small Craft Advisory (SCA) is in effect for all
Hawaiian Waters through Saturday afternoon and may need to be
extended.
A historic south swell is anticipated this weekend with surf
heights expected to reach High Surf Warning threshold along south
facing shores by Saturday night. Forerunners are already starting
to arrive and surf will be gradually building tonight and
throughout the day Saturday. The peak of the swell looks to be
Saturday night through Sunday with wave heights of 12 to 16 feet
with occasional sets of 20 feet expected. This swell should
slowly subside through the first half of next week.
Surf along east facing shores will remain elevated and rough
into early next week. Swells generated by Darby are expected to
add to the mix, with the longer period energy arriving tonight,
and likely peaking on Saturday. This swell will mainly impact
east facing shores of the Big Island, where a High Surf Advisory
is possible for Saturday.
&&
.HFO WATCHES/WARNINGS/ADVISORIES...
High Surf Warning from 6 AM Saturday to 6 AM HST Monday for
all south facing shores.
Wind Advisory from 6 AM to 6 PM HST Saturday for portions of Maui
County, Haleakala Summit, portions of the Big Island, and the Big
Island summits.
Small Craft Advisory until 6 AM HST Sunday for Maalaea Bay-
Pailolo Channel-Alenuihaha Channel-Big Island Leeward Waters-Big
Island Southeast Waters.
Small Craft Advisory until 6 PM HST Saturday for Kauai Northwest
Waters-Kauai Windward Waters-Kauai Leeward Waters-Kauai Channel-
Oahu Windward Waters-Oahu Leeward Waters-Kaiwi Channel-Maui
County Windward Waters-Maui County Leeward Waters-Big Island
Windward Waters.
&&
$$
DISCUSSION...JVC
AVIATION...Thomas
MARINE...Kino
AREA FORECAST DISCUSSION
National Weather Service Morristown TN
1053 PM EDT Fri Jul 15 2022
.UPDATE...
EVENING UPDATE.
&&
.DISCUSSION...
Just some minor adjustments to sky grids to follow most recent
satellite trends along with the usual interpolation of T/Td
observations into the forecast. Increasing mid/high clouds tonight
due to decaying activity upstream should help limit radiational
cooling and river valley fog relative to previous nights. Some
guidance such as NAM and HRRR continue to show some very weak
simulated reflectivity values as the shortwave approaches this
morning so left the slight chance of showers untouched. Previous
forecast remains largely on track and follows below. Updated zones
have been sent as well.
&&
.AVIATION...
00Z TAF DISCUSSION.
VFR conditions expected at all terminals throughout the TAF
period. High clouds will advect into the region from the N/NW
tonight ahead of a decaying MCS upstream. High cloud coverage
should limit radiational cooling, leading to little to no fog
tonight, thus, fog has been left out of TAFs. Some low VFR sct/bkn
clouds will be possible by the morning hours as the shortwave
responsible approaches the area. Brief VCSH or -SHRA cannot be
totally ruled out at TYS/TRI but confidence is too low to include
mention at this time. Winds less than 10 kts throughout the period
as well.
&&
.PREV DISCUSSION...
/ISSUED 248 PM EDT Fri Jul 15 2022/
SHORT TERM (Tonight and Saturday)...
Radar shows a few pinhead showers near the mountains and in SW VA.
Coverage should remain isolated at most through the afternoon, and
any activity should dissipate by 00Z as surface heating drops off.
Tonight, the MCS over IL will continue to track southeast. As it
encounters a drier and more stable air mass in eastern KY,
convective activity should decrease. There may not be much precip
left once it reaches our NW border around 12Z, but the HRRR and FV3
show some light precip near our border around this time. So a slight
chance PoP will be mentioned in the KY border counties tomorrow
morning. Clouds will be scattered to broken as the remnants of the
MCS move through. In the afternoon, we should see better convective
potential than we have seen today, as the midlevel cap will be
weaker and low to midlevel moisutre appears more plentiful in
forecast soundings. There could also be lingering boundaries from
the morning activity. Will have a slight chance PoP east of I-40
in the afternoon.
DGS
LONG TERM (Saturday night through Friday)...
Key Message:
1. Rain chances increase Sunday and into early next week.
2. Near seasonal temperatures expected through the forecast period.
Discussion:
Ridging continues over the western United States as a shortwave
moves towards us from the Midwest on Saturday night. This shortwave
brings increased chances for showers and thunderstorms across East
Tennessee on Sunday afternoon. By Monday morning, we will see a more
pronounced upper level trough settling over the area. An associated
cold front will be draped to our northwest across MO/IN/IL, which
will provide better forcing and the potential for showers and
thunderstorms across our area through Monday. By Monday night and
into Tuesday this positively tilted trough will sprawl across the
eastern United States, with embedded shortwaves allowing for
summertime diurnally driven convection. Another cold front that is
associated with low pressure over the Great Lakes will possibly push
through Tennessee Thursday morning and into Friday, but timing is
still uncertain.
Moisture, instability, and troughing across the eastern US keeps us
in an active pattern of summertime showers and thunderstorms each
afternoon through the extended period. As is typical with summer
thunderstorms, any convection that does develop could produce
localized heavy rainfall and gusty winds. Daily high temperatures
are expected to be near seasonal through the period--most areas
across East TN will reach the upper 80s and low-to-mid 90s each day.
Williams
&&
.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN 70 92 72 92 73 / 0 10 10 40 40
Knoxville McGhee Tyson Airport, TN 68 90 71 90 71 / 0 20 10 50 50
Oak Ridge, TN 67 90 70 89 71 / 10 10 10 50 50
Tri Cities Airport, TN 64 87 66 88 68 / 10 20 10 50 40
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&
$$
Area Forecast Discussion
National Weather Service San Francisco Bay Area
515 PM PDT Fri Jul 15 2022
.SYNOPSIS...Mild temperatures across coastal areas this afternoon
with warmer temperatures across the interior. Hottest inland
locations should peak in the mid 90s to low 100s this afternoon.
Expect additional warming on Saturday with a drying trend,
especially for higher terrain. A weak cold front approaches on
Sunday to start the next gradual cooling trend for the Bay Area
and the Central Coast. No significant swings in temperatures
expected next week.
&&
.DISCUSSION...as of 01:46 PM PDT Friday...It`s a mostly sunny
afternoon for California. Within our forecast area, we only have a
few patchy areas of marine stratus around Pt Reyes, the SF
Peninsula, and around the Monterey Peninsula.
The marine layer has been hovering between approximately 1300 ft
to 1800 ft across our CWA (based on both the Bodega Bay and Fort
Ord profilers while also looking at RH observations in higher
terrain). We expect that the building high pressure to the
southeast of our CWA will start compressing the marine layer for
Saturday. That means we could see lower marine stratus along the
coast, possibly some patchy fog. It also means that we won`t have
as much cool, moist marine air pushing inland. Thus, Saturday
highs should be peaking in the upper 90s to around 104 for our
hottest locations adjacent to the Central Valley. The 104 number
will be for the Parkfield area in the SE corner of Monterey
County. Looking at HeatRisk, we are at moderate levels across the
interior which means that those sensitive to heat (elderly, sick,
very young, pets) should take precautions by staying cool and
hydrated during the hot afternoon hours.
Besides Saturday being the warmest day of the week, we`ve also
been monitoring whether there`s any potential for monsoonal
moisture to move into our CWA. As we continue to look at hi-res
models for Saturday afternoon into early Sunday, there are hints
of instability across the southern portions of San Benito and
Monterey counties, but it`s not a scenario that would be a slam
dunk for the instability to trigger thunderstorms because the
instability is borderline. Looking at the Total Totals Index,
those southern areas of San Benito/Monterey counties are
approaching 30, but we typically look for a value of 40 or more.
Also checked model soundings and saw a blip of MUCAPE reaching
around 200 J/kg in the very SE corner of San Benito on Sunday
morning. In addition, there`s not a lot of moisture moving into
our region. The HRRR and NAM tend to suggest that peak mid level
moisture would be around 50 percent RH and it would not be long
lasting. Overall, feel that the risk is rather low which coincides
with NBM`s forecast of potential thunder...as it shows interior CA
having the potential for thunderstorms, but not in our CWA.
The upper level trough over the Eastern Pacific will nudge closer
to the coastline early next week which will put us in a very
gradual cooling trend. Don`t expect any huge swings of
temperatures, just a few degrees cooler each day.
&&
.AVIATION...as of 5:04 PM PDT Friday...For the 00Z TAFs.
Widespread VFR and breezy to gusty winds last until the late
night. The compressed marine late will limit stratus development
and movement until the late night. Expect IFR cigs to slowly fill
over the Monterey Bay and coastal areas, as well as OAK, and at
times for APC into the night. There will also be the potential for
mist and patchy fog overnight. Moments of LIFR CIGs will affect
the Monterey Bay terminals, early Saturday Morning. Widespread VFR
returns in the mid to late morning followed by another batch of
breezy to gusty afternoon winds.
Vicinity of KSFO...VFR through the TAF period. Expect winds to
remain gusty until the early night before settling into more
moderate westerly winds. Stratus will struggle to filter into the
the SF Bay into the night, but will begin to fill over OAK in the
late night causing IFR. SFO looks to only go scattered and stay so
through most of the night and into the early morning. Winds will
stay moderate into the early Saturday afternoon. Westerly winds pick
up in the mid afternoon peaking around 18 kts with 27 kt gusts.
These winds will linger into the night before becoming moderate
again.
KSFO Bridge Approach...Similar to SFO.
Monterey Bay...VFR through the evening and then IFR into the night
with light winds. Moments of IFR with patches of fog and mist will
affect the terminals into the early morning. Expect a return to VFR
in the late morning with westerly winds becoming moderate to breezy
into Saturday afternoon.&&
.BEACHES...as of 2:49 AM PDT Friday...The San Francisco Golden
Gate tidal prediction is still expected around high tide around
6.66 feet at 1:25 AM PDT Saturday morning. Despite the fact that
the tides heights are diminishing, coastal flooding is still a
risk. This potential is greatest for vulnerable, low-lying,
portions of the San Francisco bayshore which typically experience
King Tide flooding. Another Coastal Flood Advisory has been issued
for areas along the San Francisco Bay Shoreline for early
Saturday morning. While it is expected that this advisory could
potentially be the last of the advisories for this round of King
Tides, it will be re-evaluated Saturday morning. Lastly, keep in
mind that these high tides will occur overnight in the early
morning hours. Drive with caution on any bayshore roads as it may
be difficult to see if low-lying areas have water on them in the
dark.
&&
.MARINE...as of 05:12 PM PDT Friday...Hazardous, wind-driven seas
continue today and are generating steep waves up to 8 to 10 feet
in the outer waters. Gale force gusts continue along the Big Sur
coast south of Point Sur, and are also likely this evening near
coastal jet regions south of Point Arena and south of Pigeon
Point. These breezy NW winds and steep hazardous seas will likely
continue through the weekend, along with a pair of weak, longer
period S to SW swell.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.Tngt...Coastal Flood Advisory...CAZ006-506-508
GLW...Pt Arena to Pt Reyes 0-10 nm until 9 PM
GLW...Pigeon Pt to Pt Pinos 0-10 nm until 9 PM
SCA...Pt Arena to Pigeon Pt 10-60 nm
GLW...Pt Pinos to Pt Piedras Blancas 0-10 nm until 3 AM
SCA...Pt Reyes to Pigeon Pt 0-10 nm
SCA...Pigeon Pt to Pt Piedras Blancas 10-60 nm
SCA...Mry Bay until 9 PM
&&
$$
PUBLIC FORECAST: Bingaman
AVIATION: Murdock
MARINE: Murdock
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Area Forecast Discussion
National Weather Service Nashville TN
802 PM CDT Fri Jul 15 2022
...New UPDATE...
.UPDATE...
Issued at 757 PM CDT Fri Jul 15 2022
No changes to the current forecast. Weak impulse upstream could
bring a few showers to the area before or around midnight. This is
currently depicted in the grids, and Hrrr still shows the
possibility. Otherwise, tover values all positive so not
expecting fog. overnight lows/sky coverage still looks to be in
good shape.
&&
.SHORT TERM...
(This afternoon through Saturday Night)
Issued at 221 PM CDT Fri Jul 15 2022
Nashville has once again hit 90+ degrees today tying the 6th
longest streak of consecutive 90 degrees or warmer days. Looking
at visible satellite, a few areas of enhanced Cu agitation can be
noted just north of the TN/KY border, along the Tennessee River,
and near Maury county. Looking at radar, a few speckles are
showing up, so a few lucky locations could pick up a some rain
drops this afternoon. The high resolution models have additional
isolated showers moving into the area from the north overnight
ahead of a weak disturbance, so a small slight chance PoP was
included. Saturday will be a similar day today with highs in the
low to mid 90s. The upper ridge will start to retreat westward
Saturday night with a shortwave disturbance riding the eastern
edge of the ridge. This could provide enough lift for some showers
and possible a storm after midnight particularly in the northwest .
&&
.LONG TERM...
(Sunday through next Friday)
Issued at 221 PM CDT Fri Jul 15 2022
A larger scale trough will approach the area on Sunday leading to
scattered showers and storms Sunday through Monday as the trough
axis slowly swings through the area. Looking at model soundings,
it is possible to have a few strong storms Sunday afternoon as
there is ample instability and some dry air in the mid levels
which could produce some strong winds. Highs on Sunday will depend
on how long convection takes to develop. Right now, I think
Nashville will still squeeze out at least 90 degrees. Monday looks
less likely with upper troughing and ample cloud cover.
The trough will clear the area Monday night with weak ridging
replacing it. Temperatures will climb on Tuesday with most of the
area back in the low to mid 90s. Right now, Wednesday looks like
the warmest day next week with highs approaching the mid to upper
90s with dew points likely in the 70s. This means afternoon heat
index values around 105 and even a couple degrees above. As far as
rain chances after Monday, diurnally driven isolated showers and
storms will be possible each day.
&&
.AVIATION...
(00Z TAFS)
Issued at 659 PM CDT Fri Jul 15 2022
VFR conditions will continue this TAF period, with some low and
mid level cloudiness tonight and scattered cumulus on Saturday.
VCSH is possible Saturday afternoon but too uncertain too include
mention attm. Light east to southeast winds tonight will become
southerly on Saturday.
&&
.PRELIMINARY POINT TEMPS/POPS...
Nashville 72 95 75 91 / 20 10 30 60
Clarksville 71 96 73 89 / 20 10 50 70
Crossville 65 87 68 84 / 10 10 10 60
Columbia 70 94 72 90 / 20 10 30 50
Cookeville 67 90 71 86 / 20 10 20 60
Jamestown 66 88 69 84 / 10 10 20 60
Lawrenceburg 69 93 72 90 / 10 10 20 50
Murfreesboro 69 95 73 90 / 10 10 30 60
Waverly 72 96 73 90 / 20 10 50 60
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
UPDATE.......21
SHORT TERM...Reagan
LONG TERM....Reagan
AVIATION.....Shamburger
Area Forecast Discussion
National Weather Service Great Falls MT
826 PM MDT Fri Jul 15 2022
.UPDATE...
Thunderstorm activity has diminished with a few lingering showers
and storms near the ID/WY border exiting the area. There is still
some pockets of mid level instability across the region,
primarily across SW MT, where some additional isolated
shower/thunderstorm development remains possible through midnight.
Gusty surface winds associated with outflow and remnant cold
pools from earlier thunderstorm activity should diminish fairly
quickly over the next couple of hrs with generally light winds
through the rest of the night. Potential for fog development
exists in the West Yellowstone area and Centennial Valley after
skies clear later tonight with wet ground from evening rainfall.
Hoenisch
&&
.SYNOPSIS...
Thunderstorms will diminish this evening, with fairly quiet
conditions expected overnight. For Saturday and Sunday, there is a
very small chance for a passing thunderstorm, otherwise expect hot
temperatures. On Monday, it turns windy, with afternoon
temperatures not quite as hot as previous days.
&&
.AVIATION...
530 PM MDT Fri Jul 15 2022 (16/00Z TAF period)
Widely scattered thunderstorms will continue to move across SW MT
this evening with an isolated thunderstorm or two also continuing
near the AB border. Brief MVFR/IFR possible at some SW MT terminals
through 03z but most areas continue to see some gusty and shifting
wind from outflow that occurred with earlier thunderstorms in the
area. After 03z, expect VFR and generally light winds across the
area with some potential for fog development at KWYS after midnight.
Hoenisch
Refer to weather.gov/zlc for more detailed regional aviation
weather and hazard information.
&&
.PREV DISCUSSION...
/ISSUED 530 PM MDT Fri Jul 15 2022/
Tonight through Sunday...Thunderstorms will gradually diminish
from west to east. The HRRR does have a few storms redeveloping
around 7 PM, but confidence is low in this activity being
widespread or severe later this evening. For Saturday and Sunday,
generally hot temperatures are expected over the region. At this
time, no heat advisory will be issued, as much of the region is
only is only in level 2 for heat impacts. Portions of
Blaine/Fergus are a level 3, but much of that area is in the rural
portions of the county. There is a small chance for passing
mountain shower/thunderstorm on Sat/Sun...but again confidence is
low at this time for precipitation over the weekend.
Monday through Friday...Overall much of next week will have above
temperatures over our CWA. On Monday, a fairly strong upper level
disturbance will move eastward along the US/Canadian border.
Expect gusty winds to develop over North Central MT as it moves
through. At this time, wind speeds are expected to remain below
warning criteria. Additionally, no fire highlights are planned for
either. The overall chances for any precipitation from Tue thru
Friday will be quite low. Brusda
&&
.PRELIMINARY POINT TEMPS/POPS...
GTF 57 95 56 97 / 10 10 10 10
CTB 57 89 56 88 / 0 0 10 10
HLN 60 93 61 98 / 20 10 0 10
BZN 54 93 56 96 / 30 10 0 10
WYS 43 83 45 86 / 50 10 0 20
DLN 51 89 54 91 / 30 10 0 20
HVR 63 94 63 96 / 20 0 10 10
LWT 58 90 58 95 / 10 10 10 10
&&
.TFX WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
http://www.weather.gov/greatfalls
Area Forecast Discussion
National Weather Service Las Vegas NV
258 PM PDT Fri Jul 15 2022
.SYNOPSIS...Ample monsoon moisture will remain across much of the
region today bringing the potential for thunderstorms with gusty
winds and locally heavy rainfall, especially in high terrain
areas. Slight drying is expected Saturday with reduced chances
for thunderstorms. A southeast flow will continue early next week
with chances for afternoon thunderstorms primarily over the
mountains. Outside of any precipitation, above normal temperatures
and moderate to major heat risk concerns will be possible Sunday
and Monday.
&&
.SHORT TERM...Today through Sunday.
Opted to issue some short-fuse Flood Watches for flash flooding
potential in the high terrain areas of Clark and Lincoln counties
this morning due to near record PWAT values and available
convective potential across the region. As mentioned in previous
discussions, this sets the stage for convection and a marginal
risk of flash flooding for most areas, but WPCs morning upgrade
to a "slight" risk for parts of Nevada and Arizona illustrates
the growing concern for very heavy rainfall rates, albeit mostly
isolated to high elevations.
12 HREF data shows potential for 2yr ARI values being met in the
Spring, Sheep, and McCullough range with ~10-20% chances for 5 yr
values as well. The 12Z VEF sounding showed plenty of inhibition
in the low levels this morning but as convective temperatures are
reached this afternoon, showed the ability for lifted parcels to
tap into plenty of instability aloft. Also of note is a band of
meager vorticity advection in the RAP and confirmed on WV
imagery, draped across Clark and Lincoln counties extending into
western Utah. As most of today`s convection will be fueled by
heating and instability, expecting this to drop off quickly after
01Z for most areas with the exception of Lincoln county where
storms could produce strong outflows and continue to create new
updrafts as they progress eastward from central Nevada and the
Sierra.
Moving into the weekend, monsoonal moisture begins to decrease a
bit, but still plenty around for additional afternoon
convection. However, what meager dynamic lifting we may have to
play with today, even less is expected Saturday and Sunday. So
again, PoPs/QPF will favor high terrain areas that will add in
orographic ascent to the heating of the day.
.LONG TERM...Next Week.
Medium range models indicate only subtle changes in the position
over the Four Corners high through much of next week but
strengthening overall...though the trend is for it to drift
toward southern Nevada. This would lead to increasing highs for
early in the week and a gradual drying trend throughout the week.
Easterly flow develops over southern Arizona and California
directing the moisture largely south of our forecast area. This is
reflected by afternoon chances for thunderstorms over the high
terrain Sunday- Tuesday then decreasing noticeably Wednesday-
Friday.
&&
.AVIATION...For Harry Reid...Thunderstorms will continue in the
nearby mountains through the evening hours. There is a chance
outflow winds from these storms could impact the terminal at times,
but if they do it would most likely be between 02-06Z. If a storm
moves over the terminal, look for CIGS to briefly drop to around
6-7k feet. The general wind flow will be southeast with speeds
around 8-10kts, becoming southerly during the evening hours.
For the rest of southern Nevada, northwest Arizona and southeast
California...Showers and thunderstorms can be expected around the
area through the evening hours. Outflow winds, brief heavy rain, and
lightning will be possible with these storms. These storms have been
more concentrated across Mohave and Clark Counties, but the threat
will be farther north across Nye and Lincoln counties later in the
evening. Expect CIGS around 10-12k feet, but may lower to around 8k
feet with storms as they pass.
&&
.SPOTTER INFORMATION STATEMENT...Spotters are encouraged to report
any significant weather or impacts according to standard operating
procedures.
&&
$$
SHORT TERM...TB3
LONG TERM...Gorelow/TB3
AVIATION...Berc
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