Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 11/09/22
AREA FORECAST DISCUSSION
National Weather Service Hastings NE
539 PM CST Tue Nov 8 2022
.DISCUSSION...(This evening through Tuesday)
Issued at 322 PM CST Tue Nov 8 2022
Key Messages:
* A mild and breezy night with lots of clouds, a little drizzle,
light rain showers or sprinkles possible at times.
* Warm and Windy Wednesday with lots of clouds and well above
normal temperatures.
* The approaching system for Thursday continues to track faster. A
line of thunderstorms is possible along the associated front
during the pre-dawn hours Thursday. Severe weather potential
continues to decrease.
* Windy and brisk Thursday with sunshine returning. Bundle up!
* A prolonged stretch of cold weather starts behind this cold
front Thursday, with well below normal temperatures likely
through then end of the current forecast period and beyond.
A cloudy and dreary day has been observed across much of the
forecast area today. A few locations have seen some measurable
rainfall, but most locations have received just a Trace of
precipitation. Radar trends continue to diminish, and despite some
elevated instability, forcing to get additional thunderstorms to
develop does not appear there for the remainder of the evening, so
removed the chance for thunderstorms tonight. If any storms do end
up developing, they should be later in the evening/overnight and to
our north near the area where the LLJ tops over the surface front.
Given the continued southerly flow and ample cloud cover upstream
of the local area, expect another at least mostly cloudy day
across the region, with some light morning drizzle not out of the
question. Looking at sounding data, however, did not include the
potential for drizzle in the morning forecast for Wednesday as
the temp/dewpoint spread increases after about 12Z. The main
impact of the cloud cover then will be 1) to hold up overnight
temps tonight, and 2) to hold down maximum temps on Wednesday
afternoon. With the very warm overnight temps, seasonably
speaking, we should end up shattering the record warm low temps
for the date, assuming the frontal boundary tomorrow night does
not reach the tri-cities before midnight. That said, there is good
agreement among the timing of the CAMS with the frontal boundary
reaching the tri-cities around 3 AM, so new record warm minimums
appear likely.
While there is good agreement in models with the timing of this
front, at this time, there remains quite a bit of spread with the
amount of potential convection along the approaching cold front.
The latest runs of the RAP are nearly dry across our forecast
area, blossoming the front after daybreak and to the east of the
area, while the HRRR has a broken line of convection, and the
NAMnest is the most aggressive. Given the less favorable timing
of this system now coming overnight, think something more along
the lines of the HRRR appears the most likely, with a broken line
of convection across our area and the potential for a tenth to two
tenths of precipitation being the most likely scenario given the
pace of the front as it races across the local area early Thursday
morning.
Winds will also be a factor, both ahead and behind this front, and
continued to advertise gusts up to 50 mph both Wednesday afternoon
ahead of the front, and Thursday behind the front. One thing to
note, the forecast high for Thursday is well above the hourly
temperature forecast. Thus, do not expect an afternoon high near
50, but rather falling temps during the early morning hours with
afternoon temps in the 30s along with a stiff northwest wind.
Burr.
Thereafter...continue to anticipate well below normal temperatures
and dry conditions continuing through the end of the current
forecast period, with the latest hazard outlook from CPC
indicating a strong potential for below normal (possibly well
below normal) temperatures continuing through the 18th of the
month.
&&
.AVIATION...(For the 00Z KGRI/KEAR TAFS through 00Z Thursday)
Issued at 533 PM CST Tue Nov 8 2022
MVFR to IFR conditions persist through the forecast period at KGRI
and KEAR. Southerly winds remain breezy this evening, around
18-23kts with gusts as high as 30kts. There will be several hours
where LLWS will be possible. Southerly winds remain breezy through
the day tomorrow, ranging from 18-23kts with gusts as high as 30.
Stratus remains in the area for much of the period, although a few
models are trending cloud cover down slightly, to the west of the
terminals tomorrow afternoon. Around the end of the forecast
period, expect a chance of a few showers developing, particularly
north of the terminals early on.
&&
.CLIMATE...
Issued at 829 PM CST Sun Nov 6 2022
Record warmth continues to be possible Wednesday, November 9th.
The combination of strong southerly winds, elevated dewpoints and
a warm airmass ahead of an approaching cold front will help
temperatures soar across the region on Wednesday. While forecast
afternoon temps have trended cooler, record warm minimum
temperatures for the day are expected to be shattered, possibly
breaking the record warm minimum for the entire month of November.
- GRAND ISLAND airport (GRI):
Record High for November 9th: 79 (1999)
Current Forecast: 75
Record Warm Low/Minimum: 50 (1917)
Current Forecast: 60
(note: The MONTHLY record warm minimum is 59 set on 11-2-1938)
- HASTINGS airport (HSI):
Record High for November 9th: 78 (1999)
Current Forecast: 73
Record Warm Low/Minimum: 50 (1931)
Current Forecast: 60
(note: The MONTHLY record warm minimum is 59 set on 11-2-1938)
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
DISCUSSION...Rossi
AVIATION...Wekesser
CLIMATE...Rossi
Area Forecast Discussion
National Weather Service Lincoln IL
903 PM CST Tue Nov 8 2022
.SYNOPSIS...
Issued at 228 PM CST Tue Nov 8 2022
Unseasonably warm weather will prevail across central Illinois for
the next couple of days as high temperatures climb into the 70s
for Wednesday and Thursday. After that, sharply colder conditions
are anticipated by the weekend.
&&
.UPDATE...
Issued at 903 PM CST Tue Nov 8 2022
Lower clouds still remain around the area this evening, but based
on satellite loops, looks like they will not remain around the
whole area late tonight. In addition, some of the HiRes models
still bring some scattered light showers across the northern third
of the CWA, including the Mclean Co area. So update for tonight
will make a small adjustment to lower temps in the west by 1
degree and add additional sprinkles into Mclean Co. Update will be
out shortly.
&&
.SHORT TERM...(This evening through Wednesday)
ISSUED AT 228 PM CST Tue Nov 8 2022
Sprawling ridge of high pressure extending from eastern Ontario to
the Gulf Coast will continue to dominate the weather across
central Illinois tonight. As the ridge shifts further away,
easterly boundary layer flow will gradually become southeasterly.
At the same time, weak short-wave energy will track northeastward
from the Southern Plains...enhancing synoptic lift within the
developing WAA regime. The end result will be an increase in cloud
cover across the western half of the KILX CWA. Forecast soundings
suggest skies will become overcast along/west of I-55 with partly
cloudy conditions further east. A few CAMS, including the HRRR,
have been hinting at some light showers in the Illinois River
Valley. Given very dry boundary layer, do not think measurable
rainfall will occur. Have instead opted to carry scattered
sprinkles along/north of a Macomb to Minonk line late tonight into
Wednesday morning. Lows tonight will range from the lower 40s
near the Indiana border where clouds will be thinnest...to around
50 degrees in the Illinois River Valley. Once any early morning
sprinkles across the N/NW come to an end, skies will become partly
to mostly sunny across the board. With sunshine returning and
southerly flow strengthening, high temperatures will climb into
the lower 70s.
.LONG TERM...(Wednesday night through Tuesday)
ISSUED AT 228 PM CST Tue Nov 8 2022
As a strong upper low currently off the coast of northern
California shifts eastward into the Great Basin, lee cyclogenesis
will occur across eastern Colorado on Wednesday. The low will then
track into the Upper Midwest and push a strong cold front toward
central Illinois by late Thursday. Increasing southerly winds
ahead of the approaching front will push highs into the lower to
middle 70s on Thursday. Further west, a narrow band of
moisture/instability will support a severe weather risk along and
ahead of the cold front across Iowa into western Missouri. Most
models depict a thin line of convection immediately along the
front, which pushes into the Illinois River Valley in a weakening
state toward evening. 12z solutions have generally sped up the
eastward progress of the storms, so have added chance PoPs west of
the Illinois River for late Thursday afternoon. Given decreasing
instability further east, do not think severe weather will be a
threat...but have included a slight chance for thunder across the
far NW accordingly. The cold front and its associated precip will
slow considerably Thursday night into Friday morning due to a
strong blocking pattern initiated by landfalling Hurricane Nicole
across Florida. As a result, showers will likely spread as far
east as I-57 before dissipating by Friday morning.
Once Nicole lifts northeastward, the cold front will resume its
forward progress on Friday...sweeping east of central Illinois and
bringing in sharply colder weather. Thanks to brisk northwesterly
winds and overnight lows dipping into the 20s, wind-chill values
by early Saturday morning will plunge into the teens. With deep-
layer northwesterly flow in place and 850mb temps falling into the
-8 to -12C range, think air temperatures will remain in the 30s
for both Saturday and Sunday. After that, slow moderation into the
upper 30s and lower 40s can be expected by early next
week...although it appears well below normal temps will continue
through the entire week.
&&
.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 542 PM CST Tue Nov 8 2022
Main aviation forecast challenge will be potential for MVFR
ceilings at KPIA late tonight into Wednesday morning. Current
satellite loop shows high clouds pushing eastward across central
Illinois this evening and lower clouds around 5-7kft pushing
north across the area. Further west where return flow on the back
side of high pressure is more prominent, ceilings are lower to
MVFR. This moisture is forecast to lift north-northeast this
evening and may spill into the Illinois River Valley later tonight.
While some CAMs keep the lower clouds further west, both NAM and
HRRR soundings suggest they will reach KPIA overnight. Have
therefore lowered ceilings to MVFR at KPIA after 11z. With these
clouds, some of the models suggest possible light showers with the
MVFR cigs. Therefore have included a VCSH at PIA for the late
overnight through morning hours. Remainder of the sites will also
see VFR cigs around 4-5kft overnight, but then scatter out during
the early morning hours and remain scattered rest of the day. Winds
will initially be SE around 10kt this evening and overnight. SE
winds of around 10kt are expected by Wednesday morning, but then
become more southerly late morning around 10-12kts.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Auten
SYNOPSIS...Barnes
SHORT TERM...Barnes
LONG TERM...Barnes
AVIATION...Auten
Area Forecast Discussion
National Weather Service Morristown TN
855 PM EST Tue Nov 8 2022
...New UPDATE...
.UPDATE...
Issued at 848 PM EST Tue Nov 8 2022
Skies are clear this evening as surface ridging remains in
control. Clear skies and light winds will continue through the
night with a dry airmass in place. No major changes are needed
tonight and just made minor updates to hourly temperatures and
dewpoints for the next few hours.
&&
.SHORT TERM...
(This evening through Wednesday)
Issued at 324 PM EST Tue Nov 8 2022
Key Messages:
1. Calm and dry conditions expected for the remainder of Tuesday and
Wednesday.
2. Elevated fire risk today for SW Virginia and northeast TN due to
low RH values, and the recent stretch of dry weather.
Discussion:
Calm and pleasant conditons anticipated for the remainder of Tuesday
and Wednesday as high pressure and ridging remain in control of the
story. Main emphasis for this forecast period is on the elevated
fire risk due to low RH values, dry fuels, and a recent stretch of
dry weather. Went with a blend of NBM10 and HRRR for dewpoints--
dewpoints expected to be ranging from the mid-teens to mid-20s this
afternoon in SW VA and northeast TN as dry air spills into our area
from the north east. Subsequently, relative humidity values will dip
very low this afternoon and evening also. Temperatures overnight
will fall into the 40s and upper 30s.
While Wednesday will be slightly cooler than recent days,
forecast highs are still above normal. Low relative humidity
values Wednesday afternoon pose a risk for elevated fire danger
again-- many places in East TN will have RH values ranging from
low 20s to low 30s, and even lower in SW VA. Wednesday will be
much of the same with clouds increasing in our southern areas
towards the end of the forecast period.
Issued an SPS for the elevated fire risk today for southwest
Virginia, and a large portion of northeast Tennessee. The
combination of low relative humidities, dry fuels, and a recent
stretch of dry weather could allow fires that start to spread out of
control. Outdoor burning is not recommended.
&&
.LONG TERM...
(Wednesday night through next Tuesday)
Issued at 324 PM EST Tue Nov 8 2022
Key Messages:
1. Dry and warmer than normal conditions are expected Thursday.
Chances for rain increase Thursday evening into Friday as remnants
from tropical system Nicole approaches.
2. Significantly colder temperatures are expected Saturday through
early next week.
Discussion:
Thursday and Friday
Wednesday night and Thursday will be dry with a ridge and high
pressure over the region. By Thursday night, a trough will be moving
into the Ohio and Tennessee Valleys as remnants of tropical system
Nicole move into Georgia. The ECMWF brings the remnant low through
Western North Carolina Friday afternoon which would result in
roughly 2 to 3 inches of rain. The GFS has the trough pushing
Nicole`s remnants a bit farther east moving through Central North
Carolina Friday evening. A track through Central North Carolina may
produce rain totals around 1 to 2 inches maybe even lower in some
places. The models are in good agreement on timing with rain
beginning Thursday night and moving out Friday evening. Despite
uncertainty in the track of Nicole, confidence is increasing that we
will see widespread significant rain.
As the remnant low moves northeast through North Carolina, a cold
front will be moving through the Tennessee Valley Friday afternoon
or evening. Dew points and temps will begin falling significantly
Friday evening and overnight.
Saturday through Tuesday
Dry with troughing and high pressure over the region. Temps will be
colder than normal with highs in the 40s and lower 50s which is 10
to 15 degrees below normal for this time of year. Lows will be below
freezing in the 20s Saturday, Sunday and Monday nights.
&&
.AVIATION...
(00Z TAFS)
Issued at 540 PM EST Tue Nov 8 2022
VFR expected through the next 24 hours at all sites. Winds will be
light, less than 5 knots.
&&
.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN 49 72 48 72 / 0 0 0 10
Knoxville McGhee Tyson Airport, TN 44 71 43 72 / 0 0 0 10
Oak Ridge, TN 43 71 42 71 / 0 0 0 10
Tri Cities Airport, TN 33 68 43 69 / 0 0 0 10
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&
$$
SHORT TERM...Williams
LONG TERM....McD
AVIATION...Diegan
Area Forecast Discussion
National Weather Service Pueblo CO
542 PM MST Tue Nov 8 2022
.UPDATE...
Issued at 536 PM MST Tue Nov 8 2022
Updated the forecast to let Red Flag Warning for this evening
expire. Will be looking at incoming 00z models to see if a
expansion of the Wednesday High Wind Watch back toward the
Trinidad area is needed, as quick look at the latest HRRR has some
fairly high gusts (approx 60 kts) just downstream of Raton Pass.
&&
.SHORT TERM...(This evening through Wednesday)
Issued at 320 PM MST Tue Nov 8 2022
Key Messages:
1)Critical Fire Weather conditions are expected for the plains this
evening, and again for Wednesday.
2) A High Wind Watch is in effect for tomorrow afternoon on our
eastern plains, where blowing dust will also be possible.
3) Snow is expected to begin tomorrow evening in the Continental
Divide region, where blowing snow and hazardous travel conditions
will be possible.
Currently..
Southwest flow is well in place today as a strong upper level trough
makes its way on shore over California. Persistent cloud cover over
Baca county is keeping temperatures in the 60s, while the rest of
our plains have warmed into the 70s with strong downsloping and lots
of sunshine. Winds are gusting out of the south and southwest across
the entire region, with highest gusts in the higher terrain. A Red
Flag Warning remains in effect until 5pm this evening for the I-25
corridor, where relative humidity values have fallen into the single
digits and winds are gusting over 30 mph.
Tonight..
As the trough continues to push eastward, the pressure gradient
tightens overhead keeping gusty winds over our higher terrain
through the overnight hours. Temperatures stay near or just above
normal for most, with strong downsloping staying in place over
night. Our far eastern plains remain in fairly moist flow, keeping
their overnight low temperatures in the low to mid-50s tonight.
Tomorrow..
Winds really begin to crank up on our plains shortly after sunrise
tomorrow morning as a 140+ kt jet streak pushes across Colorado.
Deterministic models bring the base of the trough and associated jet
streak across south central and southeastern Colorado through the
late afternoon and early evening hours. A High Wind Watch is in
effect for this timeframe for portions of our eastern plains, to
include Kiowa, Bent, Prowers, Baca, and eastern Las Animas counties.
A Red Flag Warning is also in effect for this timeframe for all
areas along and east of the I-25 corridor. Winds are expected to
gust upwards of 60 mph on our far eastern plains tomorrow, where
blowing dust could create hazardous travel conditions throughout the
day and into the early evening hours.
Snow looks to begin across the Continental Divide region tomorrow
evening, though accumulations are looking to stay fairly light at
this time. Winds are also likely to gust up to 65 mph in the higher
terrain tomorrow, where blowing snow could create hazardous travel
conditions, especially as we get into the evening hours of
Wednesday. Daytime high temperatures are expected to soar into the
low 80s in the Arkansas River Valley and will likely be 5 to 10
degrees above normal elsewhere. This will probably be our warmest
day for quite some time..
.LONG TERM...(Wednesday night through Tuesday)
Issued at 320 PM MST Tue Nov 8 2022
Key Messages:
1) Fast moving closed low / open wave trough to move over the
region Wednesday evening through early morning bringing moderate
snowfall with gusty winds. Hazardous travel conditions are
possible.
2) Cold front pushes over the mountains Thursday to bring gusty
northwesterly winds and much cooler temperatures.
3) A series of waves are expected to propagate over southern
Colorado during the extended forecast which will reinforce cold
air over the region. Overnight lows after Saturday will be in the
teens over the plains and the single digits over the mountain
valleys.
Wednesday Night and Thursday:
The trending earlier onset time of the low pressure system that
has been discussed in previous discussions continue to remain on
track with the closed low progressing a little bit weaker, more
quickly moving, and more to the north. All of this keeps QPF and
snow amounts on the lighter side with around a 3 to 6 hour period
with bursts of heavy snow. HREF, deterministic, and ensembles are
agreeing that around .2"-.3" of QPF over the Continental Divide
during the 5PM to 11PM period on Wednesday (the heaviest snow
period), equating to around 3 to 6 inches of snow total.
Visibility will be lower during that period due to pulsy heavier
snow showers and gusty winds. Hazardous travel conditions are
possible.
Late Wednesday night in to early Thursday morning the trough axis
will push past the Pueblo CWA which will cut off snowfall rates
due to the dry air being entrained from the west-northwest. The
trends for the cold front have also changed quite a bit from
previous forecasts but remains similar to last night`s forecast.
Instead of a sharp north to south traveling front with stronger
gusts of winds to more of an anafront pushing over the mountains
from west to east. The resultant weather will be dry over the
plains and weak winds as compared to previous forecast packages.
The rest of Thursday will be a pretty typical post frontal day.
Low clouds likely will stick around, cooler, perhaps some fog over
and near the foothills during the evening.
Friday through Tuesday:
Pretty dry conditions are expected overall throughout the rest of
the period, but there will be a wave train set-up which will bring
isolated to scattered snow showers over the Continental Divide and
colder air each time the wave passes overhead. Expect the waves to
reach the region on Friday, Saturday and Monday. The big weather
story during this period are the overnight lows in the teens over
the plains and the single digits over the mountain valleys
Saturday moving onward.
&&
.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 320 PM MST Tue Nov 8 2022
VFR conditions are expected at all three TAF sites, KCOS, KPUB, and
KALS the next 24 hours. Southerly and southwesterly will likely
continue to gust to around 30 to 40kt for the rest of this afternoon
and into early this evening at all three locations. Winds will
diminish slightly overnight, but are expected to be even stronger
for Wednesday. Blowing dust could briefly reduce visibility this
afternoon, especially at KALS and KPUB, but confidence is low at
this point.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
Red Flag Warning from 11 AM to 7 PM MST Wednesday for COZ226>235.
High Wind Watch from Wednesday morning through Wednesday
afternoon for COZ094>099.
&&
$$
UPDATE...PETERSEN
SHORT TERM...EHR
LONG TERM...SKELLY
AVIATION...EHR
Area Forecast Discussion
National Weather Service San Diego CA
154 PM PST Tue Nov 8 2022
.SYNOPSIS...
Widespread heavy rain, strong winds and high-elevation snow will
impact Southern California today through Wednesday morning.
Isolated thunderstorms will be possible this afternoon into the
early evening hours. Snow levels will fall tonight into Wednesday
morning, falling as low as 4500 feet. Scattered showers will
diminish from northwest to southeast on Wednesday. Very cold on
Wednesday, with temperatures rising a few degrees each day
Thursday through this weekend. A pattern change early next week
could lead to the next chance of showers, cooler temperatures and
gusty onshore winds.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
Afternoon update:
All zones have seen moderate to heavy rainfall today, with the
highest precipitation totals occurring across the San Bernardino
County Mountains, where widespread totals of 1 to 5+ inches have
been reported. Currently, the axis of heaviest rainfall is
occurring across San Diego County early this afternoon, with
widespread rates of 0.25-0.50"/hr. In addition, convective rain
bands are beginning to develop across northern Orange County into
far southwestern San Bernardino County. The second AR band is
progressing farther south this afternoon, with associated rainfall
occurring across Santa Barbara and Ventura Counties. Strong 850
mb moisture transport vectors are pointing directly into Southern
California, so we can expect rainfall rates to remain elevated as
the band progresses farther south this evening. Please see the
Hydrology section for more details on rain impacts through
Wednesday.
In addition to the rain, very strong south to southwest winds
continue this afternoon, with the highest report occurring at
Cajon Lookout at 86 mph (San Bernardino County Mountains). Winds
will peak later this afternoon into this evening before slowly
diminishing tonight.
Previous Discussion (Issued 945 AM PST Tue Nov 8 2022)...
A strong, 535 DM low is moving inland across northern California
today. This low is beginning to progress eastward and will move
through the Great Basin and into the Northern Rockies through the
rest of today.
Snow levels will remain elevated through much of today, likely
remaining above 8000 feet through this afternoon, falling to 7000
feet this evening and as low as 4500 to 5000 feet Wednesday
morning. Please see the Hydrology section for more details on snow
impacts through Wednesday.
Analysis of the 12z ECMWF Ens Mean shows potent vorticity
rounding the base of the upper trough this afternoon, with PVA
heading into Southern California. Clearing is being noted off the
coast of Los Angeles and Ventura Counties; this could lead to
marginal destabilization today. The 16z HRRR shows surface- based
CAPE of 300-600 J/kg across the coast and valleys by this
afternoon and bulk shear values of 60+ knots. Favorable parameters
could lead to low-topped thunderstorms this afternoon across the
coastal basin, with the risk of strong winds and a brief spin-up
tornado along the leading edge of storms. This threat will persist
for a few hours this afternoon into this evening.
Southerly winds will continue to increase this morning, turning
to the southwest this afternoon before weakening and turning
northwesterly tonight. Surface pressure gradients will tighten,
with winds likely peaking in strength this afternoon. The
strongest winds are expected to occur across the San Bernardino
County Mountains into the High Desert. Winds will remain breezy
through Wednesday as the storm system exits the region to the
east, with winds out of the northwest.
High temperatures today will be cooler than those observed on
Monday, with highs ranging 5 to 20 degrees below normal for the
coast and valleys, 5 to 15 degrees below normal for the desert and
15 to 25 degrees below average for the mountains. Wednesday will
be the coldest day of the week, with highs 10 to 25 degrees below
normal for all areas.
The low pressure system will progress eastward on Wednesday and
Thursday towards the Rockies and Plains. Winds will briefly turn
offshore for Thursday and Friday, allowing for high temperatures
to rise several degrees each way through the weekend. The 00z
ECMWF Ens analysis continues to show negative 500 mb height
anomalies through Friday with highs remaining slightly below
normal, but weak ridging through the weekend centered over the
Great Basin. Seasonally cool but tranquil conditions are expected
through the weekend.
A pattern change is in store for early next week as weak longwave
troughing redevelops across the Eastern Pacific through the West
Coast. This could lead to the next chance for showers, cooler
temperatures and breezy onshore winds.
&&
.AVIATION...
082030Z...Coast/Valleys...BKN-OVC clouds with bases 600-3500 feet
MSL, layered to 15000 feet MSL with terrain obscurations. RA will
continue through the day with areas of vis 1-3SM in RA/BR through
08Z Wed. Slight chance (15-20%) of TSRA 03Z-06Z Wed, with lesser
chances through 12Z Wed. SW wind gusts to 35-40 kt will occur near
the coast through 01Z Wed. Frontal passage 01-05Z with weaker
westerly winds, gusting 20-30 kt. Cigs generally rising to 2500-3500
feet MSL after 05Z with decreasing SHRA.
Mountains/Deserts...Areas of terrain obscurations will continue
along the coastal slopes and higher peaks due to clouds/FG/SHRA/SHSN
through this evening. -SHRA possible in the deserts through 10Z Wed.
There is a slight chance of isolated thunderstorms (10-15%) through
10Z Wed in the mountains. Areas of surface W/SW winds 25-35 kt with
gusts 55-60 kt through 12Z Wed. Strong up/downdrafts and LLWS will
occur over/east of the mountains.
&&
.MARINE...
Southwest gales and hazardous seas over the coastal waters through
tonight. Winds will begin to shift westerly from northwest to
southeast after 7 PM. Winds and seas will decrease into Wednesday
morning. A Gale Warning is in effect through 10 PM tonight. No
additional marine weather hazards are expected Wednesday through
Saturday.
&&
.HYDROLOGY...
Currently, the axis of heaviest rainfall is occurring across San
Diego County early this afternoon, with widespread rates of
0.25-0.50"/hr. In addition, convective rain bands are beginning to
develop across northern Orange County into far southwestern San
Bernardino County. The second AR band (NCEP GFS IVT analysis
shows values of 500-700 kg/ms) is progressing farther south this
afternoon, with associated rainfall occurring across Santa Barbara
and Ventura Counties. Strong 850 mb moisture transport vectors
are pointing directly into Southern California with PWAT values of
1-1.1 inch, so we can expect rainfall rates to remain elevated as
the band progresses farther south this evening. CAMs show
increasing hourly rates again this evening for the aforementioned
areas, potentially reaching 0.50-1.00"/hr. This second round will
likely persist through much of tonight into Wednesday morning.
Scattered showers will diminish from northwest to southeast
through Wednesday morning.
Through Wednesday, additional forecasted rainfall totals are as
follows:
Coast: 0.50-1.25"
Valleys: 0.75-1.50"
Mountains: 1.00-4.00", local amounts to 5.00" in the San Bernardino
County Mountains
Deserts: 0.10-0.50", higher amounts closer to the mountains
Snow levels will remain near 8000 this afternoon, then decrease
from the northwest tonight to 5500 to 6500 feet, and 4500 to 5500
feet Wednesday with snowfall of 2 to 4 inches above 5500 feet, 4
to 8 inches from 6500 to 7500 feet, and 2 to 3 feet on the
highest peaks. For elevations below 6500 to 7000 feet, the more
significant snowfall is expected for tonight into Wednesday.
The higher rainfall rates for this afternoon and evening exceed
the flash flood guidance thresholds for the burn scars. Elsewhere
during periods with higher rainfall rates, there could be ponding
of water in areas with poor drainage, small stream flooding, and
urban flooding.
Rainfall is expected to be greater for the high desert areas than
the lower deserts with the the heavier totals closer to the
mountains.
&&
.SKYWARN...
Skywarn activation is requested through early this evening. Weather
spotters are encouraged to report significant weather conditions.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...
CA...Wind Advisory until 10 PM PST this evening for Coachella Valley-
Orange County Coastal Areas-Orange County Inland Areas-San
Bernardino and Riverside County Valleys-The Inland Empire-
San Diego County Coastal Areas-San Diego County Deserts-San
Diego County Valleys-San Gorgonio Pass Near Banning-Santa
Ana Mountains and Foothills.
Flood Watch through Wednesday morning for Orange County Coastal
Areas-Orange County Inland Areas-Riverside County Mountains-
San Bernardino County Mountains-San Bernardino and
Riverside County Valleys-The Inland Empire-San Diego County
Coastal Areas-San Diego County Mountains-San Diego County
Valleys-Santa Ana Mountains and Foothills.
Flash Flood Watch through Wednesday morning for Orange County
Inland Areas-San Bernardino County Mountains-Santa Ana
Mountains and Foothills.
Winter Storm Warning until 4 PM PST Wednesday for Riverside
County Mountains-San Bernardino County Mountains.
Wind Advisory until 4 AM PST Wednesday for San Diego County
Mountains.
High Wind Warning until 10 PM PST this evening for Apple and
Lucerne Valleys.
PZ...Gale Warning until 10 PM PST this evening for Coastal Waters
from San Mateo Point to the Mexican Border and out to 30 nm-
Waters from San Mateo Point to the Mexican Border Extending
30 to 60 nm out including San Clemente Island.
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PUBLIC...Schenk
AVIATION/MARINE...CO