Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 08/09/24
Area Forecast Discussion...UPDATED
National Weather Service Albuquerque NM
545 PM MDT Thu Aug 8 2024
...New AVIATION...
.SYNOPSIS...
Issued at 301 PM MDT Thu Aug 8 2024
Widespread to numerous storm chances today and tomorrow will
increase the risk of flash flooding of recent burn scars, urban
areas, and portions of northern NM where soils are saturated from
recent heavy rainfall. Precipitation chances trend down this weekend
when storms will generally be confined to the high terrain of
western and northern NM. Temps climb back above average early to mid-
next week, creating heat risk concerns in central and eastern NM.
Scattered to widespread storms next week will continue to favor the
northern and western high terrain.
&&
.SHORT TERM...
(This evening through Friday night)
Issued at 301 PM MDT Thu Aug 8 2024
Upslope flow and convergence associated with a backdoor front has
already led to widespread storm development along the central
mountain chain this afternoon. This area of enhanced lift will
continue to tap into the 500-1000J/kg of ML CAPE in place and moist
inflow will allow this convection to persist for several hours
despite the slow storm motion. Models have been in good agreement
about storm development in central and northern NM, but eastern NM
still remains a wildcard. Recent runs of the HRRR show a complex of
storms developing late tonight in the east-central plains and even a
few storms as far south as Roswell. Confidence is relatively low
since the exact location will be outflow boundary development.
Showers with embedded storms will likely continue in the north near
the CO border as well, but PoPs were decreased from what the NBM has
since coverage should consistently decrease with the loss of daytime
heating. Low clouds associated with the backdoor front have stalled
across Union county, but the frontal feature itself can be clearly
seen on radar along a line extending from northern Roosevelt county
northwestward towards the central highlands. Consistently breezy
east to northeast winds have been observed in its wake and will
continue to occur through the night until the sfc pressure gradient
finally washes out tomorrow morning. Gusty east winds associated
convective outflows have already been observed in the Rio Grande
Valley, but winds will continue to rise later today as the
reinforcing front pushes through.
With low clouds in place east of the central mountain chain,
expecting convective initiation to be delayed there. However,
confidence is high that storms will bubble up along the central
mountain chain during the early afternoon, spreading north and
eastward during the afternoon. With enhanced mid-level flow, bulk
shear will increase tomorrow, supporting the organization of storms
as they move off the mountains to the east. Strong to severe storms
cannot be ruled out as a result. PWATs of 1-2 standard deviations
above normal in northern NM will once again support efficient
rainfall and potentially a few instances of flash flooding.
&&
.LONG TERM...
(Saturday through Wednesday)
Issued at 301 PM MDT Thu Aug 8 2024
The Monsoon High will elongate over New Mexico Saturday and the
increased subsidence and downtick in moisture will result in a
downtrend in convective coverage Saturday afternoon. Locations near
the AZ and CO border will be favored for precipitation. Temperatures
will also climb a few degrees, particularly in eastern NM where the
triple digits will return to the southeast plains after the very
short hiatus. Moisture will recycle Sunday with scattered showers
and storms favoring the western and northern mountains with typical
monsoon hazards. Monday has the potential to be more active as a
shortwave embedded with the southerly monsoonal flow moves across
the state, sparking more widespread showers and storms. Despite the
advantageous flow direction and the added forcing, moisture will
remain at near normal levels. That being said, we are at the
climatological max for PWAT this time of year so a near-normal
atmosphere still has plenty of juice to produce heavy rainfall rates
of 1-2"/hour and flash flooding. The monsoonal moisture plume will
tilt across the state mid-week, introducing higher precipitation
chances into central and even eastern NM. By late week, a ridge
moving in from the west may push some dry air in the western half of
the state, decreasing PoPs there. However, some members of the
global ensembles keep a monsoonal moisture plume across the state
through the entirely of next week.
&&
.AVIATION...
(00Z TAFS)
Issued at 406 PM MDT Thu Aug 8 2024
Ongoing convection will be slower to diminish overnight due to
forcing associated with a backdoor front, which is currently
making southwest progress across eastern NM. Short-lived MVFR
conditions are likely in/near convection this evening. The front
will result in a wind shift at KROW later this evening with gusty
northeast winds expected. The front, aided by convective outflow,
will result in a strong east canyon wind at KABQ this evening with
gusts up to 40kts forecast. An Airport Weather Warning will likely
be issued for KABQ shortly. Otherwise, areas of MVFR cigs are
forecast to develop behind the front along/east of the central
mountain chain overnight and impact KLVS and KTCC with very low
IFR probabilities. Low stratus will be slower to diminish across
eastern NM Friday morning. Convection may impact terminals
around/after 21Z Friday with gusty winds and short-lived MVFR
impacts.
&&
.FIRE WEATHER...
Issued at 301 PM MDT Thu Aug 8 2024
Numerous showers and storms today and tomorrow will generally favor
western and northern areas. There is a moderate to high risk of burn
scar flash flooding and areas in north-central and eastern NM may
experience flash flooding as well. A backdoor cold front will
continue to progress south and west this afternoon and evening,
eventually creating gusty east winds through the gaps of the central
mtn chain tonight. Low clouds in eastern NM in the wake of the
boundary will create poor ventilation through at least the late
morning east of the central mtn chain. The threat of severe weather
is relatively low today, but increases tomorrow in east-central NM
where very gusty winds and large hail are possible. Shower and storm
activity trends down this weekend then increases again early next
week. Temperatures will also climb back above seasonal averages next
week, creating heat risk concerns along the Rio Grande Valley and in
eastern NM.
&&
.PRELIMINARY POINT TEMPS/POPS...
Farmington...................... 66 86 64 88 / 50 50 50 20
Dulce........................... 52 78 52 82 / 70 70 60 50
Cuba............................ 58 81 58 85 / 40 50 50 40
Gallup.......................... 57 84 58 88 / 50 50 30 20
El Morro........................ 58 80 58 84 / 50 50 40 20
Grants.......................... 60 82 60 88 / 40 40 40 30
Quemado......................... 58 82 58 87 / 40 50 30 20
Magdalena....................... 61 86 64 88 / 30 10 20 10
Datil........................... 57 81 58 85 / 30 30 20 10
Reserve......................... 57 83 57 91 / 30 60 20 10
Glenwood........................ 65 89 67 95 / 30 30 10 5
Chama........................... 50 72 50 74 / 80 70 70 60
Los Alamos...................... 59 80 61 81 / 50 60 50 50
Pecos........................... 57 81 58 83 / 60 60 50 30
Cerro/Questa.................... 52 74 51 77 / 80 70 70 60
Red River....................... 47 66 47 67 / 80 70 70 60
Angel Fire...................... 46 72 46 72 / 80 60 60 50
Taos............................ 54 79 54 81 / 70 50 60 40
Mora............................ 53 76 52 79 / 70 60 50 50
Espanola........................ 61 86 61 89 / 60 50 50 30
Santa Fe........................ 60 83 61 84 / 70 50 50 30
Santa Fe Airport................ 60 86 61 89 / 50 40 40 20
Albuquerque Foothills........... 66 91 68 92 / 40 30 40 20
Albuquerque Heights............. 66 92 67 94 / 30 20 30 5
Albuquerque Valley.............. 66 94 67 95 / 30 20 30 5
Albuquerque West Mesa........... 67 92 67 94 / 30 20 30 10
Belen........................... 65 94 66 96 / 30 10 20 0
Bernalillo...................... 65 94 66 95 / 40 20 40 10
Bosque Farms.................... 65 93 65 95 / 30 20 20 5
Corrales........................ 66 94 67 95 / 30 20 40 10
Los Lunas....................... 66 94 66 95 / 30 10 20 5
Placitas........................ 63 90 65 91 / 40 20 30 10
Rio Rancho...................... 66 93 67 95 / 30 20 40 10
Socorro......................... 67 95 69 97 / 30 10 10 0
Sandia Park/Cedar Crest......... 58 84 60 86 / 40 30 30 20
Tijeras......................... 60 87 61 88 / 40 30 30 10
Edgewood........................ 58 85 58 88 / 40 40 30 10
Moriarty/Estancia............... 57 86 56 90 / 30 20 30 10
Clines Corners.................. 56 80 56 85 / 50 30 30 10
Mountainair..................... 58 85 59 88 / 30 20 20 5
Gran Quivira.................... 58 86 59 87 / 30 20 20 5
Carrizozo....................... 64 89 64 91 / 20 30 20 10
Ruidoso......................... 57 82 58 83 / 10 30 20 10
Capulin......................... 56 74 55 79 / 60 50 80 50
Raton........................... 57 78 55 84 / 60 60 60 40
Springer........................ 58 82 58 86 / 70 50 60 30
Las Vegas....................... 57 79 55 84 / 50 50 40 30
Clayton......................... 61 76 59 85 / 40 40 70 30
Roy............................. 60 79 59 84 / 70 40 70 30
Conchas......................... 66 88 64 93 / 40 40 50 10
Santa Rosa...................... 65 87 63 91 / 40 30 40 10
Tucumcari....................... 66 88 63 92 / 40 30 40 10
Clovis.......................... 68 90 66 95 / 30 30 30 5
Portales........................ 68 91 66 95 / 30 30 30 5
Fort Sumner..................... 68 92 67 95 / 30 20 20 5
Roswell......................... 73 98 72 100 / 20 0 10 0
Picacho......................... 65 91 64 93 / 10 5 10 5
Elk............................. 60 88 60 91 / 10 10 10 5
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
Flood Watch until midnight MDT tonight for NMZ214-215-227>229.
&&
$$
SHORT TERM...16
LONG TERM....16
AVIATION...11
Area Forecast Discussion
National Weather Service Boise ID
922 PM MDT Thu Aug 8 2024
.DISCUSSION...Some light showers are tracking across e-central
Oregon and SW Idaho this evening. The chance for measurable
precipitation remains less than 10% for most locations, though
sprinkles are possible. While a wind gust to 40 mph was measured
at the Burns Airport with a passing shower this evening the
probability for gusty winds will diminish overnight. Easterly
drainage winds in the Snake Plain will be a bit stronger tonight
and could bring brief improvement to air quality Friday
morning. Current forecast is on track so no updates.
&&
.AVIATION...Low VFR with local IFR near wildfires (KBNO,
KBOI/KEUL). Patchy mountain obscuration. Surface winds: VRB
5-10kt overnight. Winds aloft at 10kft MSL: W-SW 5-15 kt. High
density altitude 18Z- 03Z each day.
KBOI...MVFR with potential for IFR from smoke. Surface winds: NW
5-10kt becoming SE 5-10kt after 03Z. High density altitude
18Z-03Z each day.
&&
.PREV DISCUSSION...
SHORT TERM...Tonight through Saturday night...
The Paddock Fire north of Emmett/ID has become the dominant
producer of near-surface smoke in southwest Idaho. According to
HRRR model another surge will spread southward into the
Treasure Valley tonight, at least as dense as last night/this
morning, but not as dense as forecast yesterday. Smoke should
decrease in the Snake Basin from the Magic valley westward as
far as Boise later Friday morning through afternoon, but another
surge is forecast southward into the Treasure Valley Friday
night.
Latest models show only minimal convective development this
evening in northern Harney County, shifting eastward into the
Boise Mountains late tonight. Only the strongest cells will
drop rain to the ground. Other cells should produce only virga.
Better chance (30- 50%) of showers and thunderstorms is
indicated Friday afternoon in central Idaho near the eastern
edge of our CWA. A weak upper trough to the north will develop
a 15-25% chance of showers and thunderstorms in Baker County
Friday evening, spreading into Idaho north of the Snake Basin
later Friday night, then increasing to a 30-50% chance in the
Boise Mountains Saturday afternoon and early evening, clearing
Saturday night.
Little day-to-day temperature change through Saturday night.
Winds should be variable less than 10 mph during the nights and
mornings, then west or northwest 10-15 mph in the afternoons.
Gusts to 25 mph in southeast Oregon Friday afternoon, and in
Owyhee County/ID Saturday afternoon. Strong gusts also near
thunderstorms.
LONG TERM...Sunday through Thursday...Warm and dry weather
expected through the period in Idaho, but eastern Oregon should
trend gradually cooler starting Tuesday as an upper trough from
the Gulf of Alaska approaches the northwest coast. No rain
expected, however.
&&
.BOI WATCHES/WARNINGS/ADVISORIES...
ID...None.
OR...None.
&&
$$
www.weather.gov/Boise
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DISCUSSION...DG
AVIATION.....SP
SHORT TERM...LC
LONG TERM....LC
Area Forecast Discussion
National Weather Service Cheyenne WY
534 PM MDT Thu Aug 8 2024
.KEY MESSAGES...
- Areas of dense fog today may lead to hazardous travel
conditions, especially over the Interstate 80 summit.
- Much cooler temperatures through Friday with multiple rounds
of scattered showers and thunderstorms expected. The highest
coverage of precipitation will be during the overnight hours.
- Expecting a gradual warmup through the weekend returning to
near normal temps.
&&
.SHORT TERM /THROUGH FRIDAY NIGHT/...
Issued at 230 PM MDT Thu Aug 8 2024
Surface analysis showing the cold front that went through us
late last night has pushed south and west. Currently along a
line from the Texas Panhandle into central Colorado...then
northwest into far southwest Carbon County into northern Idaho
this afternoon. Large surface high pressure in central
Saskatchewan Canada with a surface ridge extending south behind
that front all the way to southeast Colorado. Easterly upslope
winds easter of the Laramie Range has continued to produce low
clouds and fog. Especially here at Cheyenne and the south
Laramie Range. Dense fog still being reported over the Summit
this afternoon...so went ahead and extended the Dense Fog
Advisory through tomorrow morning.
Need to be watching the Panhandle tonight as HRRR simulated
radar continues to indicate storms developing after 08Z or so
tonight and running through 13Z tomorrow morning. Not really
too concerned with this as forecast soundings showing a pretty
strong mid level inversion that should cap convection.
Similar conditions Friday as easterly upslope winds continue.
SLightly warmer temperatures. Perhaps our best day in the short
term for thunderstorms looks to be Saturday when we get better
daytime heating. Better shear as a 90kt jet moves across the
area Saturday afternoon as well.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
Issued at 230 PM MDT Thu Aug 8 2024
The closed upper level over the Great Lakes region is progged to
remain rather stagnant this weekend which will keep the upper
level flow fairly zonal over our region. This will set the
stage for a shortwave to ride across the northern Plains on
Sunday and bring a shot of cooler air to the area along with
another round of showers and thunderstorms. This upper level
trof will gradually shift east towards the east coast early next
week. This will allow for falling heights to take place over
the Pacific northwest. As a result, monsoonal flow will become
established over our region which will result in precipitable
water values close to 1 inch through the early part of the week
along with warmer temperatures. As we head towards the end of
the week the deterministic models are showing the upper level
ridge breaking down once again as this shortwave tries to scoot
over the ridge. This would keep us in an active weather pattern.
However, the WPC clusters are indicating the upper level ridge
keeping its grip over the region through the end of next week.
If this pans out, the warmer and drier conditions will prevail.
&&
.AVIATION /00Z TAFS THROUGH 00Z SATURDAY/...
Issued at 521 PM MDT Thu Aug 8 2024
While northwest flow aloft continues, moist low level upslope
winds will keep fog, low clouds and rain in the forecast through
much of the period along and east of Interstate 25.
Wyoming TAFS...For Rawlins, ceilings will lower to 2500 feet by
09Z, then improve to 5000 feet after 15Z Friday. Winds will gust
to 25 knots until 05Z.
For Laramie, ceilings will lower to 1500 feet by 02Z, then to
800 feet in fog, reducing visibilities to 2 miles from 06Z to
15Z, then ceilings will improve to 4000 feet. Winds will gust to
30 knots until 06Z.
For Cheyenne, fog and light rain will reduce visibilities to
3/4 to 3 miles until 15Z, with ceilings from 300 to 800 feet.
Ceilings will improve to 1500 feet after 15Z Friday, and to
2500 feet by 19Z.
Nebraska TAFS...At Chadron and Alliance, ceilings will range
from 3500 to 6000 feet, with showers in the vicinity from
03Z to 08Z, and thunderstorms in the vicinity from 08Z to 12Z.
At Scottsbluff, ceilings will range from 1500 to 3500 feet until
06Z, then showers will lower visibilities to 5 miles with
ceilings near 1500 feet, with thunderstorms in the vicinity
until 14Z, then ceilings will be near 1500 feet until 18Z, then
improve to 5000 feet.
At Sidney, ceilings will be near 2500 feet until 11Z, with
showers in the vicinity until 06Z, and thunderstorms in the
vicinity from 06Z to 11Z. Light rain and fog will occur from
11Z to 17Z, reducing visibilities to 5 miles and ceilings near
700 feet. Ceilings will be near 4000 feet after 17Z Friday.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...Dense Fog Advisory until 8 AM MDT Friday for WYZ116.
NE...None.
&&
$$
SHORT TERM...GCC
LONG TERM...REC
AVIATION...RUBIN
Area Forecast Discussion
National Weather Service Green Bay WI
1032 PM CDT Thu Aug 8 2024
Updated aviation portion for 06Z TAF issuance
.KEY MESSAGES...
- A cool, early fall-like airmass will impact the area Friday through
Saturday with breezy conditions as well as lake effect showers
over the north.
- Conditions may be hazardous to mariners at times Friday and
Saturday due to breezy northwest winds, choppy waves and the potential
for waterspouts. A small craft advisory may be needed.
- Temperatures will return to near normal on Sunday and remain in
the middle 70s to lower 80s through the middle of next week.
&&
.DISCUSSION...
Issued at 241 PM CDT Thu Aug 8 2024
Short Term...Tonight and Friday
The latest RAP analysis and satellite/radar imagery show a cold
front moving east over northeast Wisconsin early this afternoon.
A potent, closed upper low is pushing this front to the east,
above a low overcast and shower activity across northern
Minnesota, southern Manitoba and northern Ontario. Despite some
clearing over northeast WI this morning, no instability could
develop along the front so far today, and will remove any chance
of thunder. As a result, precipitation along the front mainly
consists of scattered light showers that will exit northeast WI by
the end of the afternoon. Besides precipitation and cloud trends,
gusty west-northwest winds will also be the focus of the forecast.
Precipitation: A lull in the precipitation chances will occur this
evening between the showers along the front, and shower
activity/developing instability over western Lake Superior. As
winds veer to the northwest, 850mb temperatures will fall to about
4C over western Lake Superior overnight thereby creating delta T`s
about 15-16C. These temperatures will be favorable for lake effect
rain showers to develop tonight. Wind trajectories are too
westerly initially this evening, but some backing to the northwest
along with advection of 850-700mb moisture will lead to more
favorable conditions for showers to reach into the north-central
WI lake effect belts late tonight into through Friday.
With heat of the day, clouds are expected to build and spread
southeast into central and east-central Wisconsin. A few light showers
or sprinkles could develop during peak heating in the afternoon,
but mid-level capping should keep coverage as isolated to low
scattered in nature.
Winds: With steepening low level lapse rates, breezy conditions
are expected to develop on Friday. Gusts of 20-25 kts look likely
(25-30 mph), highest where most sunshine occurs. These winds will
bump up against small craft advisory conditions. Small craft
should exercise caution on the Bay on Friday.
Long Term...Friday Night Through Thursday
The extended period will be dominated by relatively quiet weather,
along with cool temperatures that will warm up again over the
weekend into next week.
Friday night through the weekend...General flow pattern keeps an
upper low north of the Great Lakes over Canada, which will keep
winds out of the west northwest through much of the weekend. The
cooler air flowing over Lake Superior will keep some showers
chances in place along the Upper Peninsula border but the rest of
the region will likely remain dry. High temperatures will be on a
slow climb upwards, from the middle 60s to lower 70s Saturday to
mostly in the 70s by Sunday.
Rest of the forecast...Temperatures continue to moderate through
the early week as high pressure moves across the area and the low
pressure system departs. High temperatures will hover near normal
throughout, ranging from the middle 70s near the Upper Peninsula
border to the lower 80s across portions of central Wisconsin and
the Fox Valley. The time period will likely be mostly dry, but
models do continue to keep a few sprinkles in the forecast of the
middle of next week.
&&
.AVIATION...for 06Z TAF Issuance
Issued at 1017 PM CDT Thu Aug 8 2024
Skies cleared and winds diminished this evening, but the next
round of clouds was rapidly approaching from NW WI. VFR ceilings
were observed near the leading edge of these clouds, but MVFR and
localized IFR ceilings were noted over much of NE MN. A few
showers were also seen on radar over NE MN and NW WI.
Upstream clouds will arrive in NC WI at the beginning of the TAF
period, then overspread the region overnight into Friday morning.
MVFR ceilings are expected to push into NC/C/far NE WI late
tonight/early Friday morning, linger through midday, and likely
the whole day in NC WI. It looks like a close call on whether or
not MVFR ceilings make it into the eastern TAF sites, but given
downsloping WNW winds, will take the more optimistic route and go
with low-end VFR ceilings. Scattered showers could impact far
northern WI overnight, and will likely develop farther south
across NC/NE WI on Friday. Partial clearing will occur over C/EC
WI Friday evening, but clouds will hang tough over far northern
WI, where some MVFR ceilings may persist.
Light northwest winds will increase by late morning Friday,
with frequent gusts to around 25 kts expected through the
afternoon. Winds should subside in most areas by sunset Friday.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
DISCUSSION.....MPC/Uhlmann
AVIATION.......Kieckbusch
Area Forecast Discussion
National Weather Service Grand Rapids MI
724 PM EDT Thu Aug 8 2024
.KEY MESSAGES...
- Cooling off with Isolated/Scattered Showers into the Weekend
- Gradual Warmup Next Week
&&
.DISCUSSION...
Issued at 311 PM EDT Thu Aug 8 2024
- Cooling off with Isolated/Scattered Showers into the Weekend
A cold front currently in WI pushes southeastward through the CWA
tonight. The latest HRRR has been showing a few showers
developing this evening along and ahead of the front. The latest
ensemble qpf values suggest very little probability for showers
through the weekend. However given the degree of destabilization
over Lake MI there should be lake effect clouds and showers
around, especially Friday night into Saturday. Delta T`s from the
lake surface to 850 mb support this potential. We will therefore
continue to feature isolated/scattered showers into the weekend,
along with some added cloud cover.
- Gradual Warmup Next Week
The cold pool sites over the Great Lakes Region and gradually
modifies with time next week. Thus the warmup will be slow. I
don`t see any 850 mb thermal ridging around through next week,
which is what we like to see if were are going to have any
significant warmup. The models have caught onto this as they have
generally trended lower with their max T values next week.
&&
.AVIATION /00Z TAFS THROUGH 00Z FRIDAY/...
Issued at 724 PM EDT Thu Aug 8 2024
VFR is likely with scattered clouds and occasional ceilings above
3,000 feet. Winds will be light from the northwest tonight,
becoming gusty to around 20 knots during the daytime Friday. There
is just a small chance of a brief light rain shower in the
vicinity of Muskegon over the next several hours.
&&
.MARINE...
Issued at 311 PM EDT Thu Aug 8 2024
Winds and waves will increase considerably behind the front for
tonight and into Friday morning. High res model wind gust suggest
we will be topping 20 knots during this timeframe. We could see a
short dip in the winds Friday but by mid to late afternoon, the
gradient tightens up and we will see the values increase once
again. With strengthening cold air advection into Saturday the
waves will build steadily with values likely to top 6 feet Friday
night into Saturday. Thus we will maintain the current set of
hazard headlines.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...Beach Hazards Statement from 2 AM EDT Friday through Saturday
evening for MIZ037-043-050-056-064-071.
MARINE...Small Craft Advisory from 2 AM Friday to 11 PM EDT Saturday for
LMZ844>849.
&&
$$
DISCUSSION...MJS/Thomas
AVIATION...CAS
MARINE...MJS/Thomas
Area Forecast Discussion...UPDATED
National Weather Service Gray ME
953 PM EDT Thu Aug 8 2024
.SYNOPSIS...
A warm front will begin to lift towards the region tonight bringing
increasing clouds and a chance for showers. Showers will continue
across the region on Friday as moisture associated with the remnants
of Tropical Cyclone Debby arrives from the south. Low pressure
passes west of the region Friday night with a period of heavy
rain possible...especially in the mountains. Clearing skies
arrive with warm temperatures Saturday...before seasonably dry
weather arrives to end the weekend Sunday.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
Update...Rain has overspread most of the forecast area and I
have increased PoP accordingly. It is also moving faster than
guidance...so I have sped up PoP moving across the forecast area
thru morning. Some embedded showers are heavier...but heavy rain
looks fairly unlikely until Fri afternoon when the true tropical
moisture arrives.
Previous discussion...High Impact Weather Potential: Locally
heavy rainfall rates possible with shower activity tonight.
Pattern: Early afternoon water vapor imagery shows the remnants of
Debby across the southeastern states with another vortex/upper low
across Minnesota moving east. This low will help drive the remnants
of Debby northward as the storm gains extratropical characteristics.
Through this evening: Shower activity in an area of broad warm
advection across the Mid Atlantic into upstate New York spread
towards the region from the south and west after 6pm. The
retreating airmass is dry...but recent renditions of the HRRR along
with the HREF suggest a few light showers reaching the ground across
SW NH through 8pm. Elsewhere...increasing clouds with temperatures
settling back into the upper 60s.
Tonight: Llevel southerly flow will continue through the overnight
with PWATS rising above 1.75" in a region of broad isentropic ascent
with the center of Debby/s remnants over North Carolina and
Virginia. This moist ascent with some weak elevated instability
should allow for an increase in shower activity overnight. Most
concentrated forcing looks to be along the H8 warm front which will
lift north of the region after midnight. This favors the heaviest
rainfall being over our far northern zones tonight with 0.5-0.75"
possible /locally higher/ with basin-wide averages less then 0.25"
to the south. Warm cloud depths will be pushing over 12kft...so any
showers will have the potential for locally heavy rainfall rates.
With the arrival of a warmer/moister airmass from the south expect
temperatures to remain in 60s for much of the area...with upper 50s
in the mountains. The moistening airmass will also favor some fog
development towards daybreak.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY/...
Isolated to Scattered Flash Flooding Possible Friday Night...
High Impact Weather Potential:
* Flash flood potential Friday evening through the pre-dawn hours
Saturday.
* Conditional severe weather threat late Friday afternoon/evening.
Pattern: Latest National Hurricane Center forecast for Debby brings
the center of a post tropical low from southern Pennsylvania Friday
afternoon northwest of our forecast area Friday night before raising
north into Atlantic Canada. Thus...the primary forecast focus will
be on the arrival of the deeper moisture/forcing with this system
and the potential this brings for flooding.
Friday: With the surface warm front quickly mixing north of the
region in the morning...forcing for ascent is pretty meager during
the day as the center of Debby/s remnants reach just west of Albany
by Friday evening. Therefore...expect relatively low shower coverage
in the morning...but with a modest increase in surface based
instability /esp southern NH/ during the afternoon...more showers
and a few thunderstorms are possible. Given what looks to be pretty
persistent cloud cover...instability will be pretty limited...
perhaps 500 J/KG in the ML. Have to watch this...however as
hodographs will have lots of llevel curvature with 0-3km SRH
values nearing 300 m2/s2. Thus...a conditional severe wind and
isolated tornado threat exists particularly over southern New
Hampshire in the late afternoon hours. Daytime total rainfall
looks pretty low on the county scale...but some localized
downpours are likely. Temperatures will climb into the mid /
upper 70s across southern New Hampshire with upper 60s to lower
70s to the north and east of this where cloud cover will be most
persistent.
Friday Night: Greatest heavy rain threat will be in this period as
PWATs push toward 2.25" in the tropical airmass associated with
Debby`s remnants cross the region. The center of the surface low
looks to pass north and west of the forecast area with the
associated cold front moving through the region after midnight. The
ingredients will be there for heavy rainfall with the aforementioned
PWATS and deep tropical airmass pushing warm cloud depths above
14kft. Primary mid level and jet forcing will remain over
upstate NY and PA where the most persistent heavy rains are
likely. Flash flood potential will result in areas that see
successive rounds of rainfall as hodographs suggest some back
building potential despite the overall progressive nature of the
system. This is most likely across the White Mountains where
the southerly flow will be upslope...boosting precipitation
potential. Guidance has trended faster in the progression of the
overall precipitation shield...but at the same time slows the
cold front as it nears the coast early Saturday morning. See
hydro section below for more details...but fully on board with a
Slight risk of excessive rain with scattered reports of flash
flooding a likely outcome. The conditional severe threat
mentioned above for late Friday will continue through the
evening Friday night...though decreasing as it becomes difficult
to maintain boundary layer instability. A rather warm night is
in store given the tropical airmass with upper 60s/lower 70s for
lows south of the mountains and mid/upper 60s to the north.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
Overview: The 500 mb ridge builds back in behind the system
Saturday before another upper trough begins to approach late
Sunday/early Monday. Multiple shortwaves then look to rotate
through the area through the remainder of the extended forecast
period. With little in the way of surface forcing, the majority
of the area likely sees fair weather with any diurnally driven
showers and storms primarily occuring in the mountains and
foothills.
Impacts:
* Rough near shore waves combined with long period swell may
pose a rip current threat and hazardous beach conditions
Saturday.
Details: Showers and thunderstorms will continue to push east
off the coast Saturday morning. Hi-res guidance continues to be
very progressive, hinting that the last of the rain potentially
exits our area by noon or shortly thereafter. This would make
the remainder of the day quite pleasant as skies clear and
dewpoints decrease. High temperatures climb into the low to
mid-80s south of the mountains, and with westerly flow this
would extend right to the coast. Areas to the north stay
slightly cooler, topping out in the upper 70s. Under mostly
clear skies, temperatures look to fall into the 50s across the
area. If Saturday does shape up to be a beach day, folks should
be aware that long period swell whipped up by this system may
bring a rip current threat and rough near shore waves may pose a
hazard to inexperienced swimmers. Sunday will feature mostly to
partly cloudy skies as well, with a slight chance for diurnally
driven showers and even a thunderstorm to pop up in the
mountains. Temperatures will be slightly cooler Sunday with
highs in the mid-70 to low 80s south of the mountains, and low
70s to the north.
Some thicker clouds begin to move into the area overnight
Sunday heading into Monday as an upper level trough looks to
swing through, but with flow orthogonal to the mountains and
Froude numbers near zero, I would expect them to get banked up
to the higher terrain, leaving southern areas mostly clear. With
the arrival of this better forcing, chances for diurnally
driven showers and thunderstorms in the mountains and foothills
will be greater as well. High and low temperatures will look
very similar to Sunday. Clouds thin Monday night as the upper
trough departs. Depending on the timing of a shortwave, the
chance for a diurnally driven shower or thunderstorm in the
mountains is non-zero. Clearer skies will help high temperatures
climb a few degrees warmer for Tuesday with lows staying steady
in the 50s.
Global models keep us in a pattern where shortwave troughs look
to rotate through area, with variations in timing, through at
least Thursday, however with little in the way of surface
forcing shower activity would be diurnally driven and not
widespread. It may even stay isolated to the mountains and
foothills. The low chance PoPs the NBM has seem reasonable to
cover the uncertainty at this time range.
&&
.AVIATION /02Z FRIDAY THROUGH TUESDAY/...
Short Term...
Summary: A warm front will lift towards the region tonight and cross
the region Friday before the remnants of tropical storm Debby push
through the region Friday night. The result will be deteriorating
conditions as clouds increase and lower with shower activity
developing this evening and continuing through Friday before a
period of heavy rain moves through the region Friday night.
Restrictions: Current VFR conditions are expected to persist through
this evening. Overnight deterioration to IFR CIGS and IFR/MVFR
VSBYS is expected with scattered shower activity. While VSBYS
may improve during the day Friday...IFR/MVFR CIGS will be
slower...with the best potential for improvement at MHT/CON/PSM.
Elsewhere...low CIGS will likely hold through the day. IFR CIGS
with IFR/MVFR VSBYS will continue Friday night with a period of
locally heavy rain expected Friday night.
Winds: Southeast winds 5-10kts diminish to 5kts or less tonight.
East-southeast winds continue 5-10kts on Friday before shifting
southerly and increasing to 10g20kts Friday night.
LLWS: LLWS is likely Friday night as low pressure moves west of the
region. 2kft southerly winds may increase to around 50kts with
the period of greatest potential being 00-08Z Saturday.
Lightning: An isolated thunderstorm is possible tonight LEB/HIE/AUG.
Little in the way of thunderstorm activity is expected Friday
morning...but by mid/late afternoon chances will increase for a
thunderstorm throughout the area with those chances continuing area-
wide through Friday night.
Long Term...Saturday morning will start MVFR or lower for most
terminals, but conditions will be improving as the morning goes on
with VFR prevailing across the area by late afternoon. VFR will then
prevail through Tuesday. Southwesterly winds look to be gusting in
excess of 20 kts through Saturday morning at coastal terminals,
tapering off in the afternoon. Some thunderstorms are possible
Saturday morning and then each afternoon Sunday through Tuesday.
&&
.MARINE...
Short Term...Southeast winds and waves will remain below SCA
levels through the day Friday. Winds shift south and quickly
increase Friday night with gusts over the waters of 30-35kts
likely. Thus...SCAs will be necessary and we/ll have to watch
for the potential of a few gale force gusts.
Long Term...Southerly wind gusts will remain in excess of 20 kts
through the day and slowly taper off through the evening as
they shift westerly. Winds will remain primarily westerly
through Tuesday. Seas will slowly calm below SCA criteria during
the day Sunday.
&&
.HYDROLOGY...
Looking at the first batch of rainfall early Friday morning as a
warm front lifts north ushering in tropical moisture. This initial
round will help prime the ground, but is not likely to cause
any flooding concerns. Shower activity will be more hit/miss
until the more organized support later in the day and Friday
night. Repeating showers with pockets of heavy rainfall with
rates over 2"/hr could lead to locally high totals over 3". The
heaviest showers are likely to occur with the cold front
overnight Friday night which would bring torrential rates over
saturated ground conditions, leading to rapid runoff. The areas
of highest concern are the SE facing slopes of the White
Mountains and W ME mountains where upslope enhancement and
training could occur. Additionally recent rains have wetted
ground conditions in other areas that will likewise be
vulnerable to flash flooding. Larger rivers are not expected to
flood, however some fast responding streams in the higher
terrain could come out of banks.
In collaboration with neighboring offices...have issued a flash
flood watch across northern NH which matches our highest
rainfall forecasts to locations that have the wettest antecedent
conditions.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...None.
NH...Flood Watch from Friday afternoon through Saturday morning for
NHZ001>004.
MARINE...None.
&&
$$
NEAR TERM...Legro
Area Forecast Discussion
National Weather Service Houston/Galveston TX
1103 PM CDT Thu Aug 8 2024
...New UPDATE...
.UPDATE...
Issued at 940 PM CDT Thu Aug 8 2024
CAM guidance has shown stronger consistency with regards to the
development of thunderstorms on Friday from the aforementioned
inverted jet streak. This MCS is progged to develop in the Brazos
Valley late in the afternoon, subsequently tracking south before
dissipating near the coast late that night. HRRR PBL heights
also suggest the possibility of storms developing along the sea
breeze as well, in part due to the rather substantial instability
across the region. Either way, most storms appear to develop in
areas largely west of I-45, confined to areas W/SW of a weak
backdoor front in the vicinity. Low level lapse rates are steep,
near 9.8 Deg C/km within the lowest 1 km. SFC CAPE values are in
excess of 3000 J/KG (with isolated values in excess of 4000 J/KG
possible with compressional heating). 3km CAPE peaks near 100-140
J/KG in some isolated spots. Otherwise shear remains very low.
Thunderstorms will be pulse-y in nature, capable of producing
damaging wind gusts. Depending on where storms/boundaries set up,
an isolated funnel or landspout could develop as well.
03
&&
.SHORT TERM...
(This evening through Friday Night)
Issued at 305 PM CDT Thu Aug 8 2024
Have extended the Heat Advisory over SE TX through tomorrow evening
(with further extensions possible - see Long Term below).
Not much has changed with the larger scale weather pattern as ridg-
ing aloft remains in place across much of the state. But, we should
see some changes at the lower levels as a weak backdoor front moves
in overnight. This boundary isn`t going to give us any cooling, but
it could help to raise PWs (up to 2-2.3") for tomorrow. Models seem
to be hinting that we could see isolated shower/thunderstorm devel-
opment during the afternoon tomorrow (via jet streak activity aloft)
but confidence not too high with this at this time. Have kept POPs
low to none (<20%)...for mainly the W/NW portions of the CWA.
Otherwise, the other issue with this increased low-level moisture is
going to be its impacts on heat index values tomorrow afternoon...a-
long with the light winds and triple digit high temperatures. And so
look for peak heat index values in the 108-112F range for the after-
noon and early evening. Please continue to be mindful of heat safety
as these dog days of summer persist. 41
&&
.LONG TERM...
(Saturday through next Wednesday)
Issued at 305 PM CDT Thu Aug 8 2024
The forecast for the extended period remains on track with a
fairly stagnant synoptic pattern expected to bring an extended
period of hot and mostly rain-free weather to the area that will
prevail through at least the middle of next week. Upper ridging
will continue to remain dominant over the South Central CONUS,
with 500mb heights over SE TX remaining near 595 dam. With a broad
area of high pressure also sitting over the Eastern Gulf, a light
onshore flow pattern will continue to supply Gulf moisture, and as
such the primary concern for this period will surround the
potential for high heat indicies.
Temperatures in the extended period will remain in the upper 90s
to around 100 for most inland locations, and in the mid 90s closer
to the coast. With surface dew points in the mid 70s for most of
the area, it`s likely that we will reach Heat Advisory criteria.
Heat stress will be further exacerbated by a lack of cloud cover
and light winds, which will drive max WBGT values above 90 during
the afternoon hours. Additionally, low temperatures in the upper
70s to low 80s will inhibit recovery from daytime heat stress. As
such, heat safety precautions will continue to remain paramount.
Limited but nonzero rainfall chances return to the forecast early
next week, driven mainly by the inland advance of the sea breeze
each afternoon. These low (10-20%) chances should generally remain
confined to areas along the coast, but a stray storm or two
further north cannot be totally ruled out.
Cady
&&
.AVIATION...
(00Z TAF Issuance)
Issued at 507 PM CDT Thu Aug 8 2024
Light winds and VFR conditions should dominate the TAF period. A
weak frontal boundary may enter SE Texas on Friday, bringing
northeasterly winds. Isolated storms will be possible Friday
afternoon, mainly in areas west of I-45. Confidence in storms
developing is too low to warrant mention in the current TAF.
03
&&
.MARINE...
Issued at 305 PM CDT Thu Aug 8 2024
Light winds, low seas, and little to no rain chances will persist
for the foreseeable future. Winds may at time approach 15 knots,
but it`s unlikely that caution thresholds will be reached for the
time being.
Cady
&&
.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL) 78 100 79 99 / 0 30 30 10
Houston (IAH) 81 100 81 99 / 0 20 20 10
Galveston (GLS) 81 92 82 93 / 0 20 10 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...Heat Advisory until 9 PM CDT Friday for TXZ163-164-176>179-
195>200-210>214-226-227-235>238-300-313-335>338-436-438-439.
GM...None.
&&
$$
SHORT TERM...41
LONG TERM....Cady
AVIATION...03
MARINE...Cady
Area Forecast Discussion
National Weather Service Pueblo CO
553 PM MDT Thu Aug 8 2024
.KEY MESSAGES...
- Scattered showers and a few thunderstorms will be possible
through the evening, mainly over the southern mountains and
southeastern plains.
- Overcast skies with continued unseasonably cooler temps for
the plains tomorrow. Showers and thunderstorms will become
numerous by the afternoon hours, mainly over the higher
terrain.
- Flash flooding will be a concern again tomorrow for the burn
scar and possibly urbanized areas which are prone to flooding.
- Unsettled weather continues into this weekend and early next week
with slowly warming temperatures.
- Flash flooding may become an increasing concern as more rain
moves into the area, with showers and storms possible each
day.
&&
.SHORT TERM /THROUGH FRIDAY/...
Issued at 249 PM MDT Thu Aug 8 2024
Tonight...
Latest high res models suggest that the majority of showers and
thunderstorms by later this evening will be more confined to being
over the southern mountains and southeastern plains where conditions
are a little more unstable. The HRRR is showing much more that other
guidance with respect to precip over the southeastern plains during
the morning hours, although I believe that it is the dry bias and
over-mixing causing the high amount of precip and therefore have
brought down PoPs over this area. Further north and especially over
the plains, the lower levels look to even more stable and have even
less confidence of there being much in the way of any precip,
although perhaps the lower stratus deck could support some light
rain. The low clouds will also help to keep temperatures cool
tonight, but somewhat modified. Lows will be in the mid 50s to low
60s across the plains, and generally in the 40s to low 50s for high
country, with evening a few upper 30s for the highest elevations.
Tomorrow...
With a cooler airmass already in place and persistent northeasterly
to easterly winds, and upslope flow, it will remain much cooler
tomorrow with temperatures well below the seasonal average for this
time of year across the plains. The upslope enhancement may also
help to trigger off some showers and possibly thunderstorms along
the I-25 corridor by later in the afternoon, although the plains
look to be too stable (capped) again to allow for much in the way of
any convection, perhaps just some showers over the adjacent plains
and portions of the I-25 corridor. For the higher terrain, there
will be more instability, although not enough to raise any alarms to
storms becoming stronger or severe.
There will be a lot of moisture throughout the mid and upper levels.
Due to this, showers and thunderstorms developing over the higher
terrain will bring about the chance for brief periods of heavy rain
and thus there could be flash flooding concerns again tomorrow,
especially for the burn scar areas. As convection further develops
in the afternoon and possibly moves over some of the urbanized areas
which are prone to flooding, there could also be the potential of
flash flooding concerns for these areas as well, although
Nevertheless, WPC has a slight risk of excessive flooding over a
large portion of the CWA again tomorrow (covering the entire high
terrain and I-25 corridor), with a marginal risk elsewhere. Highs
again will likely remain in the 70s across the plains, with only
some lower 80s across portions of the plains within the vicinity of
the Purgatoire River where there will be more clearing taking place
with cloud coverage. Values will be closer to the seasonal average
but still cooler over the higher terrain. -Stewey
&&
.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
Issued at 249 PM MDT Thu Aug 8 2024
Saturday-Sunday...
Upper-level ridging will start building in this weekend, with
several shortwaves passing through the flow and increasing our
chances for showers and thunderstorms. The passing shortwaves,
coupled with the ample moisture in place across the area, will
assist in expanding the coverage of precipitation over and near the
higher terrain, where storms are expected to fire in the afternoon
on both Saturday and Sunday. Luckily, with the northwest steering
flow firmly in place, storms should continue to move and somewhat
work to limit some flash flooding concerns to areas that get hit
with multiple rounds of rain. The plains will be a bit more of a
challenging forecast, due to inconsistencies in the models with
regards to instability. The amount of cloud cover will have a big
impact on whether we get proper thunderstorms or more stratiform
type rain showers will some embedded thunder. Models are generally
pretty middle of the road today, with most of the higher CAPE values
closer to the mountains with decreasing confidence further towards
our eastern border. More sunshine and a bit better heating will be
most likely for the plains near the southern Sangres and the Raton
Mesa, out east to Baca County, so if we were to get some of those
stronger storms for the plains, the highest chance will be down
there, though we can`t rule out some thunder elsewhere.
Temperatures will warm a bit as the ridge starts to build in, with
highs on Sunday hitting the high-80s to low-90s over the plains.
Monday Onwards...
Monday will serve as a transition day as flow aloft becomes more
southwesterly, with the upper high shifting off to the east-
southeast. A stronger shortwave disturbance will translate through
the flow, leading to some stronger, possibly severe, thunderstorm
development in the afternoon.
Model confidence decreases a bit as we move into next week, though
the west-southwest flow aloft will continue. More daily afternoon
showers and storms will continue, especially over the Continental
Divide. High temperatures will also warm slightly, climbing back
into the 90s across our eastern plains.
&&
.AVIATION /00Z TAFS THROUGH 00Z SATURDAY/...
Issued at 544 PM MDT Thu Aug 8 2024
At KALS, vcts this evening, with gusty winds and a brief period
of lower visibility due to blowing dust possible. VFR but with
vcsh continuing overnight, then VFR Friday morning before vcts
returns after 20z. At KCOS and KPUB, occasional MVFR cigs and
vcsh this evening into early Fri morning, and a period of IFR
cigs at KCOS possible 10z-15z. Cigs lift to VFR by 18z Fri, then
a vcts returns to both terminal 22z-23z.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SHORT TERM...STEWARD
LONG TERM...GARBEROGLIO
AVIATION...PETERSEN
Area Forecast Discussion
National Weather Service Reno NV
119 PM PDT Thu Aug 8 2024
.SYNOPSIS...
* Smoke and haze will continue to impact portions of the region
through the weekend.
* Outside of a 10-20% chance for storms south of US-50 today, the
forecast largely remains dry.
* Breezy winds Friday-Monday will bring enhanced fire weather
concerns along with choppy lakes. This will usher in cooler
temps for next week.
&&
.DISCUSSION...
* The Crozier and Park Fires continue to actively burn this
afternoon, and based on the HRRR smoke model and current flow,
another round of smoke will push into the region this afternoon
and evening. For the Crozier Fire, the near surface smoke density
appears highest into the northern half of the Tahoe Basin and
Carson City/Washoe Valley, with lesser amounts into South Lake and
Reno/Sparks. No, that doesn`t mean we`re in the clear, just not as
bad. Smoke from the Park Fire will mainly push into areas
stretching from Susanville to Lovelock, with lighter haze possible
to the Oregon border on the northern edge and I-80 on the southern
edge. You can find the latest air quality information on
fire.airnow.gov, or by checking with your local county air quality
district. Some variety of smoke and haze are likely to continue,
but exact impacts will be dependent on how actively the fires
burn.
* While we have had reports of a few random sprinkles this morning
near and north of I-80, the more likely places for spotty
wetting rain will be south of US-50 were there remains a 10-20%
chance for showers and thunderstorms this afternoon. These are
the type of storms that will be hit or miss, but brief periods
of localized heavy rainfall and gusty outflow winds will be
possible. Otherwise, the forecast largely remains dry through
the weekend and into the start of next week. By mid-week, a
compact upper wave may bring the return of showers and storms,
but it also depends on the track of this feature.
* A series of troughs brushing just north of the region will bring
increased afternoon breezes each day Friday through Monday,
with the greatest risk (40-75% chance, location dependent) of
gusts exceeding 30 mph on Sunday and Monday. This will bring
enhanced fire weather concerns given the dry conditions in place
and localized areas may see 1-3 hours of critical conditions
each afternoon. Area lakes will also be choppy.
* These troughs will also usher in a cooler airmass, which will be
a nice change of pace after the hot summer the region has
experienced so far. By Monday and through next week, temps will
be near to below normal for this time of the year. Just for
reference, KRNO has seen 21 days so far this year with the high
temperature at or above 100 degrees. This is the 2nd highest
total, only behind 22 days in 2021 and 2022. We`ll be close to
hitting that triple digit mark again today, so stay tuned. -Dawn
&&
.AVIATION...
* Smoke and haze will primarily be aloft with slantwise reductions
into KRNO, but surface visibility remaining VFR based on the
latest ensemble simulations. Otherwise, only other item of note
for KRNO will be typical WSW afternoon breezes today and a
slight uptick in wind speeds Friday-Monday with gusts near 30
kts at times each afternoon.
* KTRK/KCXP/KMEV have the greatest risk of surface visibility
reductions due to smoke from the Crozier Fire, but the degree of
the impacts will be dependent on how actively the fire burns.
We`ll also see smoke impacts stretching from KSVE-KLOL from the
Park Fire, with terrain obscurement expected. KTVL is a bit of a
wildcard and may remain just out of the worst conditions, but
still anticipate at least slantwise visibility obstructions by
this evening.
* A 10-20% chance for showers and isolated thunderstorms this
afternoon and evening for the Eastern Sierra of Mono Co
(including KMMH) eastward towards KHTH. Storms may produce
reduced cigs/vis, but it will be localized, along with gusty and
erratic outflow winds. -Dawn
&&
.REV Watches/Warnings/Advisories...
NV...None.
CA...None.
&&
$$
Area Forecast Discussion
National Weather Service Tallahassee FL
913 PM EDT Thu Aug 8 2024
...New UPDATE...
.UPDATE...
Issued at 912 PM EDT Thu Aug 8 2024
No significant changes to the previous forecast appear necessary.
Lingering isolated showers and thunderstorms across southwest
Georgia should diminish in the next few hours. For early Friday
morning, some thunderstorm activity could develop along the big
bend coast in association with the land breeze and a weak surface
boundary.
&&
.NEAR TERM...
(Through Friday)
Issued at 315 PM EDT Thu Aug 8 2024
A few showers and thunderstorms are ongoing this afternoon as a weak
shortwave moseys over the region. A few wind gusts in excess of 40
mph are possible within any thunderstorms this afternoon and into
the evening. A strong to severe wind gust cannot be entirely ruled
out, especially as storms approach the eastern Big Bend where RAP
analysis shows DCAPE values over 1000 J/kg. Any activity this
afternoon should wind down near or following sunset.
Another hot day is in the offering again Friday with highs climbing
into the middle to upper 90s. With temperatures a degree or two
lower than today, heat indices should generally top out between 108
to 112 degrees Friday afternoon. A Heat Advisory will be issued at a
later shift to avoid confusion with the ongoing Excessive Heat
Warning for today (Thursday). That said, there is an outside chance,
less than 20 percent, of one or two locations nearing or exceeding
Excessive Heat Warning criteria, or a heat index in excess of 113
degrees, Friday afternoon.
Much of the area is forecast to remain dry Friday afternoon as drier
air aloft filters in from the north. However, a subtle shortwave
embedded within the mean H5 flow may be enough to spark an isolated
shower or storm. Some of the storms may be capable of producing
damaging wind gusts as model soundings from around the area show an
inverted-v profile.
&&
.SHORT TERM...
(Friday night through Saturday night)
Issued at 315 PM EDT Thu Aug 8 2024
A deep upper level low is expected to push a weak frontal system
into our region, late Friday night into Saturday. Guidance
currently favors storm development along the sea breeze and east
of the weak frontal, where moisture and weak lifting mechanism
are greatest. Damaging wind gusts, perhaps strong to severe at
times with the drier air influence, and heavy rain look to be the
primary hazards. In addition to storms, another hot day is on tap.
Highs are expected to be in the mid to upper 90s for much the
region, with the Big Bend being a few degrees lower and in the low
to mid 90s. Heat Index values of 105 to 112 are expected, with a
few localized areas potentially meeting excessive heat warning.
Will need to see how the cloud cover, precip looks, and
temperatures trend before issuing any product this far out.
&&
.LONG TERM...
(Sunday through Wednesday)
Issued at 315 PM EDT Thu Aug 8 2024
Ensemble and cluster analysis shows the upper level trough that
absorbed Debby skirting along the northern Great Lakes Sunday into
Monday. Behind it upper level ridging builds to the west, leaving
us with more zonal flow this period. Then, as we head into the
work week ensembles keep the trough, albeit not as deep, of the
northeast. Upper level ridging from the west builds and then
dominates much of the region as it expands into the Plains and
Upper Midwest. The influence form the ridge is expected to expand
into our region, leaving us with northwest flow for the start of
the work week. Will need to keep an eye on that as it could raise
MCS concerns, but it`s too early to pin point anything yet. We can
expect to see typical summer time weather with daily shots of
showers and thunderstorms and high temperatures in the low to mid
90s.
&&
.AVIATION...
(00Z TAFS)
Issued at 750 PM EDT Thu Aug 8 2024
VFR conditions will prevail through the TAF period. Mostly dry
conditions are expected but isolated thunderstorms are possible on
Friday, with the highest probabilities for storms across VLD.
&&
.MARINE...
Issued at 315 PM EDT Thu Aug 8 2024
Moderate winds are being observed by surrounding buoys, supporting
gradually improving conditions. Seas will generally remain around
2-3 feet through the end of the work week, before dropping to
around 2 feet by the weekend as winds slowly relax. Winds are
expected to continue to decrease through the beginning of the next
work week to around 5 knots or less, which will lead to tranquil
boating conditions. There will be daily chances showers and
thunderstorms, particularly during the overnight and morning
hours.
&&
.FIRE WEATHER...
Issued at 315 PM EDT Thu Aug 8 2024
Mostly dry conditions are expected through Friday. There is an
outside chance of a few showers and storms across the FL Big Bend
again on Friday. While rain chances will be low, the only fire
weather concerns will be high dispersions along with hot
temperatures with heat indices pushing 105 to 110 degrees.
&&
.HYDROLOGY...
Issued at 315 PM EDT Thu Aug 8 2024
Rivers remain elevated with the Aucilla River at Lamont,
Steinhatchee at US-19, and Valdosta at Skipper Bridge remaining in
minor flood stage for a few days. The Suwannee River is expected to
have some rises and may reach minor flood stage over the weekend or
early next week. Will need to keep an eye on that to see how the
water levels trend. Outside of that, mostly dry weather prevails
through the work week. Chances for showers and storms improve over
the weekend.
Outside of that, the other area of hydrologic concern is Madison
County where more than 12 inches of rain from Hurricane Debby. A
Flood Warning was issued for Madison County until at least Friday
afternoon. Madison County Emergency Management reported rising water
levels in the southeastern portion of the county, just south of
Interstate 10 east of County Road 360, especially in the vicinity of
I-10 and Exit 258. Water levels are likely to continue to rise and
gradually spread to areas south and east across the county as
localized runoff continues. Numerous roads are flooded, along with a
campground near Exit 258 being significantly impacted. Some roads
are already or will soon become impassable. For those that may be
traveling through Madison County, be mindful of road conditions. If
you see a flooded road turn around, don`t drown!
&&
.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 78 95 77 94 / 10 30 10 50
Panama City 80 93 80 93 / 10 10 10 40
Dothan 76 96 77 97 / 10 20 10 20
Albany 77 97 77 96 / 10 20 10 30
Valdosta 78 95 77 95 / 20 20 10 50
Cross City 79 93 78 91 / 20 30 10 60
Apalachicola 81 90 80 90 / 20 30 20 50
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
FL...High Rip Current Risk through late Friday night for FLZ112-114.
GA...None.
AL...None.
GM...None.
&&
$$
UPDATE...DVD
NEAR TERM...Reese
SHORT TERM...KR
LONG TERM....KR
AVIATION...Dobbs
MARINE...KR
FIRE WEATHER...Reese
HYDROLOGY...KR
Area Forecast Discussion
National Weather Service Tucson AZ
147 PM MST Thu Aug 8 2024
.SYNOPSIS...Scattered showers and thunderstorms each day into this
weekend with the exception of Saturday which could see reduced
coverage. Storms will have the potential for heavy rainfall and
strong wind gusts. Temperatures slightly below normal today then
warm up to above normal levels Friday through the weekend into
early next week.
&&
.DISCUSSION...Storms are beginning to pop up over the higher
terrain as of 1:30 PM this afternoon over the Sky Islands. There
is still some debris clouds mainly over Western Pima County,
Tohono O`odham Nation, and Northeastern Graham County. The
activity should remain in the higher elevations over the next
couple of hours before making their way into the valley floors
later this afternoon and evening. The thunderstorm ingredients are
either in place or beginning to shape up with MLCAPE being in the
1000-1500 J/kg range over most of Southeast Arizona, where the
only exceptions are where the remnants of the debris clouds are
located with some CIN being there due to lack of surface heating.
The PWs are ranging from 1.00"-1.75" with the higher values areas
Tucson westward. Areas with the best shear are areas north of the
forecast area, however there is some weak directional shear with
the surface being from the NW and the overall upper flow from the
SE, so there could be some potential for sustained updrafts. Since
we are still in that moister environment, DCAPE is in the 700-900
J/kg range, decreasing the overall severe wind threat, but is
still possible. Aiding in longer lived updrafts is the semi-
favorable placement of the upper level low that is currently
located over the Gulf of California making some upper level
diffluence available as well. Interestingly, the RAP model is
showing some areas of 1-3 in the Microburst Composite, so that is
something of note that stronger storms are possible today. Similar
to yesterday there is very light steering flow of 5-10 kts so
thunderstorms will be slow moving with possible accumulations
between 1"-2" and can be higher in localized areas. The main
threats with thunderstorms this afternoon and evening are heavy
rainfall leading to possible flash flooding, some gusty winds
(30-40 mph), and frequent lightning. Overnight some CAMs are still
hanging onto some thunderstorm activity through about 2 AM, so
that is something to keep in mind tonight.
Looking ahead to tomorrow, the overall activity is very much
dependent on if/how long thunderstorm activity sticks around in
the overnight hours to determine how active it is on Friday
afternoon and evening. Conditions are still favorable for
thunderstorm activity with moisture sticking around for much of
the forecast area minus areas east of Tucson, daytime heating,
and lift still available. The HREF CAMs are highlighting
southeastern Pinal, Pima, and Santa Cruz counties but not as much
in coverage as today. The weekend continues to look to decrease
in activity slightly with each day as the moisture begins to cycle
and limit much of the coverage to areas mainly west of Tucson.
After this weekend, there is currently no hints at any extra
dynamics or moisture surge in the longer range models to increase
confidence on any specific higher impact monsoon days as of now.
Overall high temperatures are slightly above normal (3-6 degrees)
though next weekend. Stay tuned to forecast as it changes.
&&
.AVIATION...Valid through 10/00Z.
SCT-BKN clouds at 6k-9k ft AGL and BKN-OVC clouds AOA 15k ft AGL
thru this evening then gradual clearing overnight into the
morning. SCT SHRA/TSRA thru 09/06Z, slowly diminishing
thereafter with possible ISOLD SHRA/TSRA thru 09/09Z. MVFR
conditions expected near TSRA, with VSBY restrictions, wind gusts
to 40+ kts, heavy rain and mountain obscurations. Outside of
thunderstorm wind gusts, wind speeds will be less than 12 kts,
favoring an SWLY through NWLY direction in the afternoon and early
evening hours and variable in direction at other times. Aviation
discussion not updated for TAF amendments.
&&
.FIRE WEATHER...Isolated to scattered mainly afternoon and evening
showers and thunderstorms are expected through the upcoming
weekend with a possible down day Saturday. There is a chance for
some overnight activity tonight. Min RH values will be in the
25-40 percent range in the valleys through Thursday (and higher in
the mountains), decreasing to 15-30 percent Friday through the
weekend for the upper Gila Valley and Sulfur Springs Valley.
Outside of thunderstorm outflow winds, 20-foot winds will
generally be 15 mph or less, with afternoon/early evening gusts to
20-25 mph and light winds overnight.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
Tetrault
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Area Forecast Discussion
National Weather Service Las Vegas NV
731 PM PDT Thu Aug 8 2024
.SYNOPSIS...Monsoonal moisture will remain in place through the
weekend helping to fuel afternoon and evening thunderstorms over
portions of southern Nevada, northwest Arizona, and eastern San
Bernardino Counties. Above normal temperatures will continue through
the end of the week high pressure persists over the Southwestern US.
Drier air is forecast to push into the region next week reducing the
thunderstorm chances and bringing slightly cooler temperatures to
the region.
&&
.UPDATE...Scattered thunderstorms developed this afternoon across
the terrain of Clark, Lincoln, and Mohave counties. While extensive
cloud cover kept convection from getting organized, enough weak
instability still exists even at this hour for thunderstorms to
persist in Lincoln County through southwest Utah and northern Mohave
County. This area will need to be watched through the evening as
some models have these storms producing a decent cold pool and
outflow. Area observations do show gusty 25 to 35 MPH northeast
winds in the St George, UT area pushing into eastern Lincoln and
northeast Clark County...So the cold pool exists but will it be able
to push southwest through Clark and Mohave counties tonight is the
question. The 00Z HRRR is concerning, bringing this outflow through
the area with showers and thunderstorms developing in it wake which
then becoming an MCV that persists over Mohave County overnight.
However this is just one of the HRRR and the other runs have been
far less robust. The less robust scenario match up better with other
hi-res CAM models and would make more sense with the given
environment where instability is waning and cloud cover kept things
at bay through the day. Most likely, the northeast winds will
translate through Lincoln, Clark, and Mohave counties through
midnight with low to isolated moderate impacts- including gusts up
to 30 MPH and isolated but brief and unorganized showers and
thunderstorms with heavy rain. Will need to watch how things develop
in the next few hours though as an MCV in Mohave County is not out
of the question and could result in moderate to isolated high
impacts due to heavy, persistent rain leading to flash flooding.
Updated precipitation chances through the night to represent the
most likely trend in showers and thunderstorms.
Otherwise, it will be a quiet night with low temperatures running a
degree or two cooler than last night.
-Nickerson-
&&
.PREVIOUS DISCUSSION...100 PM PDT Thu Aug 8 2024
.SHORT TERM...through Friday night.
Expansive cloud cover that originated last evening over northern
Arizona continues to push west through northern Mohave and Clark
Counties. This has helped to suppress convection under this cloud
shield, but areas that have seen sunshine are starting to fire this
afternoon. Strongest convection so far has occurred over the Spring
Mountains and Sheep Range where radar has estimated over an inch of
rain has fallen so far. We are also starting to see convection fire
over southern Mohave County where a lot of the CIN has eroded and
CAPE values have increased to around 1000-1500 J/KG. With PW values
still around 150% of normal combined with increasing instability, we
will see more widespread afternoon and evening thunderstorms over
northwest Arizona. Convection will likely be delayed until mid to
late afternoon over the higher terrain of eastern San Bernardino and
eastern and central Clark County due to the current cloud cover.
These storms will be capable of producing heavy rain and with DCAPES
around 1000-1500 J/KG gusty outflow winds are also a possibility.
Some convection will be possible through the overnight hours as
little areas of higher vorticity remain over the region. At this
time, nothing looks overly organized, but enough to keep some
thunderstorms going well into the overnight period.
Friday look to have a similar setup as today with good instability,
high PW values and potentially more sunshine to start the day. The
most active areas look to be southern Nevada, northwest Arizona, and
eastern San Bernardino Counties. Winds aloft will remain fairly
light which could lead to more flooding concerns and gusty outflow
winds will also remain a concern through the afternoon.
.LONG TERM...This Weekend through Wednesday.
Thunderstorms chances are expected again Saturday as ample moisture
sits over the region. The highest PWATs will be along and southeast
of the I-15 which is where the highest rick for afternoon
thunderstorms will exist, with a lower but non-zero risk further
west. Will need to watch if the upper level wave that will be
sitting over southwest California will be able to add any forcing
and thus increase convection coverage and impacts. Ensembles still
do not signal for a significant or widespread flash flooding event
with probabilities for 0.50 and 1.0 inch of rain in a 4 hour period
remains low to none (less than 20%). The difference in 24hr rainfall
amounts for Saturday on NBM percentiles is large, but nothing
atypical for monsoon season. The the percentile 24hr rainfall
accumulation for Saturday does paint much of Mohave County with
about 1 inch amounts, so if there was higher impacts it could
potentially be through there however probabilities for over even
0.50 in a 24 hour period tops out at 30% in the terrain. On Sunday,
the moisture will begin to retreat as an upper level trough pushes
into the West Coast, but most areas southeast of the I-15 will hang
to PWATs over 1.00 inch so there is a continued heavy rain though
thunderstorm chances will drop slightly compared to Saturday in
southern Nevada. With modest instability shown on long range models
both days, any storms would also bring the risk for lightning, gusty
outflow winds, and small hail. People with outdoor plans this
weekend in eastern portions of San Bernardino and Nye counties as
well as all of Clark, Lincoln, and Mohave counties should stay up to
date with the forecast and be prepared for thunderstorm impacts.
The upper level trough will continue to move into the West Coast the
beginning of next week with long range models in decent agreement
that the trough will move into California with only slight
discrepancies in its strength. Either way, the flow will turn
southwest which will scour out the moist air across much of the
region. Thunderstorm chances Monday through Wednesday will be
confined to Mohave County and areas east. The trough will also help
cool temperatures with slightly above normal temperatures dropping
to about normal by Tuesday.
&&
.AVIATION...For Harry Reid...Thunderstorms develop along high
terrain around the Las Vegas Valley this afternoon and early
evening. Any storms that form may produce frequent lightning and
gusty outflow winds which would cause temporary changes in wind
speed and direction at the terminal. Outside of storms, winds should
generally be out of the southeast. Gusty southerly winds pick up in
the evening and should shift to the east overnight. If the winds do
not shift east, they most likely maintain a southerly to
southeasterly direction. Variable winds return in the early morning
hours. Outflow winds from storms around the region may influence
wind speed and direction at any time overnight.
For the rest of southern Nevada, northwest Arizona and southeast
California...Thunderstorm development around the Las Vegas Valley
may lead to gusty and erratic outflow winds at KHND and KVGT this
afternoon and early evening. Additional outflow boundaries from
storms around the region may cause change in winds overnight at KHND
and KVGT as well. Outside of thunderstorms, winds should be out of
the east to southeast this afternoon and evening. Storms in
northwest Arizona may not reach the vicinity of the terminal but
should create gusty easterly outflow winds at KEED and KIFP in the
evening. Lastly, thunderstorms over the Sierra should reach the
vicinity of KBIH this afternoon. At KDAG, variable winds this
afternoon turn to the southwest overnight and become gusty,
decreasing early tomorrow morning.
&&
.SPOTTER INFORMATION STATEMENT...Spotters are encouraged to report
any significant weather or impacts according to standard operating
procedures.
&&
$$
SHORT TERM...Gorelow
LONG TERM...Nickerson
AVIATION...Meltzer
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