Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 06/24/20
Area Forecast Discussion
National Weather Service El Paso TX/Santa Teresa NM
522 PM MDT Tue Jun 23 2020
.AVIATION...00Z TAF CYCLE...
A few areas of visibility less than 1 mile...skies BKN030 and wind
gusts greater than 40KT in showers and thunderstorms mainly east
of the Rio Grande through 06z. Otherwise VFR conditions with skies
SCT-BKN100 with wind speeds around 5-15KTS. Thunderstorms may
redevelop especially for areas east of the Rio Grande after 20Z on
Wednesday.
&&
Rogash
.PREV DISCUSSION...146 PM MDT Tue Jun 23 2020...
.SYNOPSIS...
Afternoon showers and thunderstorms, especially east of the Rio
Grande will be possible through at least Thursday. A few storms
could be severe tonight and Wednesday. Drier air will move in for
the end of the week into the weekend, but winds will be on the
increase with temperatures remaining at or slightly above normal.
Some moisture may start to return again early next week as a deep
trough moves into the western U.S.
&&
.DISCUSSION...
.SHORT TERM...Tonight through Wednesday...
Ingredients in place for scattered thunderstorms/isolated severe
storms tonight and again on Wednesday. CAMS models have been in
pretty good agreement with a later than normal start to the
convection this afternoon seems to be working as we are just now
starting to see some development over the Black Range and the west
slopes of the Sac Mtns. Pre storm environment showing potential for
severe storms, especially east of the Rio Grande Valley with high
MUCAPEs and DCAPEs. Believe damaging winds biggest threat as shear
profile not too strong and WBZ not real favorable for large hail
(but can`t rule it out). Also many of the CAMS models showing
organized linear convection associated with short wave aloft over NW
New Mexico moving southeast late this afternoon and early evening
just north and east of our CWA. HRRR showing nice outflow dropping
south through the Tularosa Basin down to west Texas.
Expect much the same again Wednesday as upper high over the northern
Baja remains nearly stationary and unchanged-maybe slightly more
northerly flow aloft as opposed to northwest. MUCAPEs/DCAPEs lower
than today but still respectable, again mainly east of the Rio
Grande Valley. Bottom line...expect roughly same coverage of
thunderstorms as today-perhaps a bit further east, and some risk of
severe storms due to winds-but less than today. &&
.LONG TERM...
Period will likely start out with storms ongoing over at least
areas east of the Rio Grande moving south. Decent instability will
still exist and modest shear so SPC putting eastern zones into
marginal risk looks reasonable. A weak upper ridge pushes a little
further east for Thursday, but models continue to keep dew points
at or above 40-45 degrees in eastern zones so kept some isolated
to slight chance pops there. With dry, westerly surface winds west
of the divide, should see warmest temperatures out that way where
100-103 looks likely while 95-100 over the lowlands for areas east
of the Rio Grande.
Another very small push east with the moisture for Friday, but
even on the dry EC, dew points remain high enough and on the
northerly flow side of the ridge, some storms are still possible
coming off the mountains, but severe threat should be diminished
as shear values really drop off. An upper trough moves across the
area Saturday which should generally push moisture east, but if a
storm or two could develop, would be confined to the mountains.
Increasing westerly surface winds, possibly up to 15-25 mph, will
allow highs to get back into the 100+ degree range for almost all
of the lowland locations.
Another fairly deep trough for the end of June over the western
CONUS could tap some moisture from the Baja region and bring a
return to some storms as early as Monday, but think a slower
movement of this system is more likely along with moisture return,
so just kept pops under 10 and did bring in some 10-20 pops
starting Tuesday. Highs will remain in the mid 90s to around 100
through early next week. Overnight lows will mainly be in the 60s,
but areas around El Paso could easily be in the lower to mid 70s
with westerly winds going through the night in the 5-15 mph range.
&&
.FIRE WEATHER...
Scattered thunderstorms will continue tonight and Wednesday, with a
few potentially becoming severe with damaging winds and/or large
hail. Some potential still for dry lightning west of the Rio Grande
Valley where dewpoints are lower. Temperatures seasonable both
tonight and Wednesday. A chance of thunderstorms will remain on
Thursday and Friday but limited mostly to areas east of the Rio
Grande Valley. Temperatures will climb back above normal Thursday
into the weekend.
Min RHs 10-20% west of the Rio Grande Valley Wednesday, with min RHs
15-30% to the east. Min RHs decreasing to 8-15% Thursday through the
weekend, except remaining around 15-25% zone 113. Vent rates very
good-excellent through the weekend west of the Rio Grande Valley and
fair-good to the east.
&&
&&
.PRELIMINARY POINT TEMPS/POPS...
El Paso 72 97 73 100 / 20 20 20 0
Sierra Blanca 65 92 65 93 / 30 20 20 10
Las Cruces 68 96 66 99 / 20 20 20 0
Alamogordo 65 96 66 99 / 30 30 20 20
Cloudcroft 50 71 51 74 / 50 50 20 30
Truth or Consequences 68 96 67 99 / 20 20 20 0
Silver City 63 90 63 92 / 0 10 0 0
Deming 65 99 64 102 / 0 10 0 0
Lordsburg 65 99 64 101 / 0 0 0 0
West El Paso Metro 73 98 74 101 / 20 20 20 0
Dell City 65 96 65 97 / 30 20 30 20
Fort Hancock 71 99 71 101 / 30 20 20 0
Loma Linda 68 90 69 94 / 30 20 20 0
Fabens 73 99 73 101 / 20 20 20 0
Santa Teresa 68 97 69 100 / 20 10 20 0
White Sands HQ 72 97 73 99 / 30 20 20 0
Jornada Range 63 96 63 99 / 30 20 20 0
Hatch 65 97 65 101 / 20 20 20 0
Columbus 68 100 68 102 / 0 10 0 0
Orogrande 68 96 68 98 / 30 20 20 10
Mayhill 53 80 55 85 / 40 60 20 30
Mescalero 52 82 53 86 / 50 50 20 30
Timberon 50 78 52 83 / 40 40 20 30
Winston 53 87 54 92 / 20 30 10 0
Hillsboro 60 94 60 100 / 20 30 20 0
Spaceport 63 95 63 97 / 20 20 20 0
Lake Roberts 54 90 54 93 / 0 20 0 0
Hurley 60 93 59 95 / 0 10 0 0
Cliff 52 97 54 99 / 0 0 0 0
Mule Creek 54 96 52 95 / 0 0 0 0
Faywood 61 93 61 97 / 0 20 0 0
Animas 64 101 64 102 / 0 0 0 0
Hachita 62 99 61 100 / 0 0 0 0
Antelope Wells 64 100 65 100 / 0 0 0 0
Cloverdale 63 94 65 95 / 0 0 0 0
&&
.EPZ WATCHES/WARNINGS/ADVISORIES...
NM...None.
TX...None.
&&
$$
05-Rogash/99/99
Area Forecast Discussion
National Weather Service Lincoln IL
840 PM CDT Tue Jun 23 2020
.SYNOPSIS...
Issued at 248 PM CDT Tue Jun 23 2020
A cool night with lows in the mid to upper 50s is in store for
central Illinois. Conditions will be partly sunny on Wednesday
with highs around 80. The next chance of rain will be Thursday
night into the weekend.
&&
.UPDATE...
Issued at 840 PM CDT Tue Jun 23 2020
A mid level shortwave continues to slowly rotate through central
IL around a 500 mb low centered north of Lake Superior this
evening. Showers and a few thunderstorms continue ahead of the
shortwave axis, currently from around Shelbyville to Paris to the
I-70 corridor. RAP soundings show an inversion around the 10000
foot level blocking vertical development for most areas, although
a pocket of stronger instability has been able to overcome this
inversion and convect above the -10 C level from around
Taylorville to Mattoon to Effingham causing a few thunderstorms.
Nocturnal stabilization and subsidence behind the trough axis
should end most shower/thunderstorm activity by 10 pm. Updates
have been sent for the above mentioned features. Otherwise, skies
should clear overnight producing fairly strong cooling and lows in
the upper 50s to around 60.
&&
.SHORT TERM...(This evening through Wednesday)
ISSUED AT 248 PM CDT Tue Jun 23 2020
Moisture channel imagery shows upper short wave from western
Great Lakes into mid MS river valley. Some very isolated showers
seen in radar data in the enhanced CU beneath the upper trough,
over IL, but instability and moisture is limited and so lack of
vertical development has been the trend through the afternoon.
Expect some of the isolated showers to continue to sunset, then
much of diurnal cloudiness to diminish overnight.
Weak northwest flow Wednesday in the low levels, with a secondary
weak upper system to rotate through region and bring few
scattered storms possible during the day, mainly in the north.
.LONG TERM...(Wednesday night through Tuesday)
ISSUED AT 248 PM CDT Tue Jun 23 2020
In the extended, the pattern shifts again, with the upper level
ridge starting to build toward area on Thursday, bringing a warming
trend again. Scattered POPS in the forecast with mainly afternoon
scattered convection becomes the trend, a more typical summer
pattern. Collaboration with offices resulted in decrease in the POPS
for the extended periods into the weekend.
Best chance of rain, appears to be with short wave seen in models
for Friday night into Saturday, as it brings a frontal system into
the area. Problem is that operational models differ in frontal
movement and then after the upper system moves past, the stalled
front lags over IL region, with weak upper ridge building over.
Result is that for Sunday into first part of week, scattered summer
type convection possible, so lowered guidance POPS with surrounding
offices.
&&
.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 615 PM CDT Tue Jun 23 2020
VFR conditions expected over the upcoming 24 hours, although brief
SHRA will be ending at KCMI and KDEC around 00Z this evening, and
isolated TSRA are possible Wednesday afternoon with coverage too
low for mention in 00Z TAFs. SCT-BKN cloud cover around 5000 feet
AGL expected until 01Z this evening, as well as Wednesday
afternoon after 17Z. Winds W-NW around 10 kts or less through the
period, with a few higher gusts remaining until 01Z this evening.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...37
SYNOPSIS...Goetsch
SHORT TERM...Goetsch
LONG TERM...Goetsch
AVIATION...37
Area Forecast Discussion
National Weather Service Newport/Morehead City NC
956 PM EDT Tue Jun 23 2020
.SYNOPSIS...
Upper-level troughing over the Midwest and Northeast will
persist, providing unsettled weather through Thursday. Deep
layer ridging strengthens Friday, keeping drier conditions in
place into the weekend.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
As of 950 PM Tue...No significant changes to the current
forecast as the sfc analysis continues to show the low pressure
over the Great Lakes with it`s attendant cold front moving
through the OH/TN Valley and troughing across the Carolinas.
The latest radar returns are showing mostly dry continues across
ENC, but a line of showers and thunderstorms are located over
the SandHills area and tracking towards the coastal plains.
These showers and storms will reach our FA within the next hour
or so. The latest HRRR and RAP continues to show these
additional showers and thunderstorms into the area late night
and diminishing as it moves through the area. Though more
showers can redevelop as the sfc trough and shortwave starts to
push into ENC through the overnight hours, but in general it
should be mostly dry. Lastly, scattered showers and storms
could try to develop over the waters late tonight and early
morning and lift along the coast. Lowered pops a bit from
previous forecast given the drier model trends but will keep a
sc/chance mention. Lows in the 70s overnight.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH 6 PM WEDNESDAY/...
As of 230 PM Tue...Sfc trough/shortwave will shift off the
coast Wed morning and should see subsidence aloft in its wake.
Isolated to scattered showers and storms possible along the
coast early, with activity shifting inland during the afternoon.
Still doesn`t look like much diurnal coverage, and will keep
sc/low chance pops focused along the typical sea breeze
corridor. Low level thickness values and SW flow support highs
near climo, in the mid to upper 80s.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/...
As of 3 AM Tue...Bermuda High ridging in from the east and
inland troughing will persist through the long term period,
bringing generally seasonable conditions with day to day
variability dependent mainly on upper level synoptic trends.
Thursday...Troughing sliding over the eastern seaboard will
bring broad destabilization and ample deep moisture transport,
and Thursday could see above normal thunderstorms coverage, with
convective trends mainly following the normal diurnal cycle. The
NAM indicates that potential for a shortwave aloft to bring
widespread storms, but this feature is much more muted in other
guidance so have not bit to hard on it for the time being. Highs
will be a few degrees below normal, owing primarily to the deep
moisture bringing partly to mostly cloudy skies through the
day.
Friday and Saturday...Upper trough axis shifts east of the area
early Friday, bringing broad upper subsidence and below- climo
POPs, with ample sunshine both days. Temps near to a few degrees
above normal both days.
Sunday and Monday...Troughing develops over the Northeast with a
transition of more zonal flow aloft locally, and a general trend
to typical summertime precip and temp patterns.
&&
.AVIATION /02Z WEDNESDAY THROUGH SUNDAY/...
Short Term /through Wednesday/...
As of 7 PM Tue...High confidence in VFR conditions to dominate
the period. A mix of low- and high level clouds will continue to
stream through the area tonight and overnight as a disturbance
moves through. SW winds of 5-8 kt will remain overnight which
will hamper the potential for fog development. By morning, the
wind shifts to the W at 5-10 knot with mid to high clouds.
Expect afternoon diurnal clouds with chances of showers and
thunderstorms.
Long Term /Wednesday night through Sunday/...
As of 3 AM Tue...VFR conditions prevail through the period,
with only the potential for early morning fog/stratus and
afternoon thunderstorms bringing any significant potential for
flight restrictions each day.
&&
.MARINE...
Short Term /through Wednesday/...
As of 1000 PM Tue...Latest obs show S/SW winds 15-25 kt, with
seas 2-3 ft north of Oregon Inlet and 4-6 ft south. The
gradient will continue to tighten tonight ahead of an
approaching trough. SSW winds will increase to 15-25 kt this
evening and tonight, strongest across the waters south of Oregon
Inlet, which will allow seas to build to 4-6 ft. SCA continues
through Wed morning south of Oregon Inlet for gusty winds and
elevated seas. Added SCA for the Pamlico Sound as well for freq
gusts to 25 kt. Winds and seas will gradually subside through
the day Wed as through pushes off the coast. SW winds generally
10-15 kt with seas subsiding to 2-4 ft by late afternoon.
Long Term /Wednesday night through Sunday/...
As of 3 AM Tue...High pressure well offshore and inland
troughing will persist through the long term period bringing
persistent moderate southwesterly flow, typically a few kts
stronger each afternoon than overnight. Expect 3-5 ft seas to
then prevail through Thursday in mainly SSW windswell, with a
small secondary medium period swell also mixed in. Seas subside
to 2-4 ft later in the week as wind swell decreases and the
medium period swell fades.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...None.
MARINE...Small Craft Advisory until 11 AM EDT Wednesday for AMZ154.
Small Craft Advisory until 9 AM EDT Wednesday for AMZ152-156-
158.
Small Craft Advisory until 5 AM EDT Wednesday for AMZ135.
&&
$$
SYNOPSIS...MHX
NEAR TERM...CQD/BM
SHORT TERM...CQD
LONG TERM...CB
AVIATION...BM/CB
MARINE...CQD/BM/CB
Area Forecast Discussion...UPDATED
National Weather Service Mobile AL
1049 PM CDT Tue Jun 23 2020
.NEAR TERM /Now Through Thursday afternoon/...Area radars are
currently detecting scattered to numerous showers, along with
embedded isolated thunderstorms, mainly along and north of U.S.
Highway 84. Prolonged periods of moderate rainfall could occur
over some areas, resulting in localized ponding of water and minor
flooding. This activity will diminish to very isolated showers
over the area after midnight. After a lull in precipitation,
scattered showers and and a few thunderstorms will begin moving
into our southeast Mississippi counties toward daybreak Wednesday
as an upper level impulse approaches from the southwest. Temps
this evening are trending as previously forecast, but are not
expected to drop off much further as we expect overnight lows in
the 69 to 73 degree range inland areas, and from 74 to 79 degrees
along the coast.
An upper low pressure area over the central Great Lakes will lift
northeast over southeast Canada and deepen through Thursday
afternoon. This upper low is embedded in a large upper trough that
stretches over much of eastern North America. This trough is
forecast to advance slowly eastward through the near term. A
surface ridge extending from the western Atlantic to the eastern
Gulf of Mexico will remain in place keeping a southerly surface
wind through the period. The overall pattern supports a deep
southwesterly wind flow over the region through the period with
precipitable water (PWAT) values near 2.0 inches. A small upper
cutoff low pressure area over eastern Texas, at the base of the
large upper trough, will move very slowly eastward over Louisiana
by Thursday morning.
There is the potential for another area of dry mid level air to
be advected from the northern Gulf into the area on Wednesday,
mainly the southern half during the afternoon. This would
maintain the potential for strong to possibly marginally severe
downdrafts again on Wednesday, tempered somewhat by lower MLCAPE
values expected to range from 1000-1500 J/kg. Locally heavy
rainfall will also be possible with the stronger thunderstorms
each day which could lead to nuisance type flooding issues. The
combination of decreasing stability both Wednesday and Thursday,
along with a series of upper level impulses and disturbances being
ejected out of the upper low to our west and passing over the
forecast area, will trigger numerous to definite showers and
thunderstorms on Wednesday, and mainly scattered showers and
thunderstorms on Thursday.
High temperatures on Wednesday will range from 78 to 85 degrees
northwest of I-65, and from 85 to 88 degrees to the southeast.
Lows Wednesday night will range from 68 to 73 degrees inland
areas, and from 74 to 79 degrees along the coast. High temps on
Thursday will be warmer, and range from 82 to 88 degrees northwest
of I-65, and from 88 to 91 degrees to the southeast. /22
&&
.PREV DISCUSSION... /issued 702 PM CDT Tue Jun 23 2020/
AVIATION...
00Z issuance...Scattered showers and thunderstorms along and west
of I-65 this evening will diminish to mainly isolated showers
over the area by late this evening. After a brief lull, numerous
showers and thunderstorms will increase in coverage across
southeast Mississippi Wednesday morning and spread eastward
throughout the day. MVFR conditions can be expected with the
stronger thunderstorms along with potentially strong wind gusts
with otherwise VFR conditions expected. South to Southwest winds
10 to 15 knots this evening, with the higher values near the
coast, diminish to 5 knots or less overnight then increase to 5 to
10 knots Wednesday morning. /22
PREV DISCUSSION... /issued 324 PM CDT Tue Jun 23 2020/
NEAR TERM UPDATE /Now Through Wednesday/...An upper trof over
the eastern states broadens somewhat through Wednesday but
otherwise remains in place. An associated surface low is currently
located over the Great Lakes with a cold front which extends from
near the Ohio River valley to Arkansas. As the surface low moves
further off to the north, the trailing frontal boundary dips into
northern Alabama/Mississippi on Wednesday and stall. A surface
ridge remains in place over the northern Gulf and maintains a
southwesterly flow over the forecast area. This maintains a moist
pattern over the region through Wednesday with precipitable water
values near 2.0 inches. A modest series of shortwaves move across
the area within the base of the upper trof pattern today followed
by a stronger series of shortwaves on Wednesday. This trend and
the moist pattern will support likely pops for much of the area
this afternoon followed by mainly categorical pops on Wednesday.
MLCAPE values of 1500-2250 J/kg are expected today with values
ranging from 1000-1500 J/kg on Wednesday, moderated by increased
cloud cover and somewhat lower afternoon highs. Despite the moist
pattern, the 12Z sounding at JAN indicated abundant drier air
above 700 mb, also indicated in the LZK sounding above 600 mb.
It`s difficult to determine how expansive this drier air region
is, but following with the RAP guidance the drier air likely
shifts into the forecast area today albeit with some modification
due to entrainment from convection. RAP DCAPE values of 1000-1500
J/kg hence look possible and expect the stronger storms to be
capable of strong to potentially marginally severe wind gusts this
afternoon. On Wednesday, there is the potential for another area
of dry mid level air to be advected from the northern Gulf into
the area, mainly the southern half, during the afternoon. This
would maintain the potential for strong to possibly marginally
severe downdrafts again on Wednesday, tempered somewhat by the
somewhat lower instability. Locally heavy rainfall will also be
possible with the stronger storms each day which could lead to
nuisance type flooding issues. Lows tonight range from around 70
well inland to the mid 70s at the coast. Highs on Wednesday will
be mostly in the mid to upper 80s. A moderate risk of rip currents
is expected through Wednesday. /29
SHORT TERM /Wednesday night Through Friday night/...Upper trough
over the eastern states moves little through Thursday before
finally pushing east off the Atlantic coast by Friday night. As a
result, we continue to see unsettled weather under its southern
periphery Thursday with scattered showers and thunderstorms
developing during daytime hours. At the surface, high pressure
continues to ridge from the western Atlantic into the southeastern
states, maintaining a southerly flow across the region. With
moderate instability and ample moisture available, could see some
gusty winds with stronger storms due to precip loading in
downdrafts. This would be in addition to the typical summertime
threats of frequent lightning and heavy downpours. Rain chances
drop off Thursday night as weak ridging builds over the area, with
only a slight chance for a few isolated storms over southeast
Mississippi on Friday. Low temps range from upper 60s to low 70s
inland and mid to upper 70s along the coast. Highs on Thursday
remain in the mid 80s where coverage of storms will be greatest,
and upper 80s to low 90s elsewhere. Temps on Friday will be warmer
due to the more sparse coverage in clouds and storms, with most
areas seeing low to mid 90s. Some locations could see heat indices
reaching the 100 to 103 degree range on Friday. /49
EXTENDED TERM /Saturday Through Tuesday/...Upper ridging weakens
as another shortwave trough ejects from the Desert Southwest over
the south Plains to our west. This, in combination with the
persistent southerly flow at the surface and in the lower
troposphere, will support diurnal summertime convection each day
through the weekend. Best chance for thunderstorms will be during
afternoon hours, with activity tapering off each evening with the
loss of daytime heating. Above-seasonal rain chances return
everywhere early next week as the upper trough rotates into the
lower Mississippi River Valley and upper forcing increases over
the local area. Temperatures change little throughout the period
(welcome to summer along the Gulf coast), with upper 80s to low
90s expected across much of the area each afternoon. Lows range
from low 70s inland to mid 70s along the coast each night. /49
MARINE...Will have Small Craft Exercise Caution wording this
evening for the near shore waters as well as Mississippi Sound and
southern Mobile Bay due to southwest winds near 15 knots. Locally
higher winds and waves are possible near scattered to numerous
showers and thunderstorms through the period. /29
&&
.MOB WATCHES/WARNINGS/ADVISORIES...
AL...None.
FL...None.
MS...None.
GM...None.
&&
$$
This product is also available on the web at:
http://weather.gov/mob
Area Forecast Discussion
National Weather Service Reno NV
808 PM PDT Tue Jun 23 2020
.UPDATE...
Showers and a few thunderstorms are stubbornly holding on across
eastern Lassen County early evening and redeveloping into parts of
central Washoe County. This in is response to various outflow
boundaries now drifting around the region and a weak shortwave
trough that is aiding in the redevelopment. All of this activity
should decrease before midnight.
We have allowed the Red Flag Warning for the southern Sierra Front
to expire; the storm activity there has ended.
Another round of storms is expected Wednesday only this time there
is likely to be greater coverage as another shortwave moves into
the region. These storms may be wetter as available moisture
increases as well.
&&
.SYNOPSIS...
Above average temperatures will continue through Saturday. There
are chances for afternoon and evening showers and thunderstorms
through Wednesday, with Wednesday expected to have more widespread
coverage. Increasing winds over the weekend will bring concern for
the rapid spread of any fires that start. Sunday into early next
week will bring a major cool down.
&&
.PREVIOUS DISCUSSION... /Issued 214 PM PDT Tue Jun 23 2020/
SYNOPSIS...
Above average temperatures will continue through Saturday. There
are chances for afternoon and evening showers and thunderstorms
through Wednesday, with Wednesday expected to have more widespread
coverage. Increasing winds over the weekend will bring concern for
the rapid spread of any fires that start. Sunday into early next
week will bring a major cool down.
SHORT TERM...
Main change to the short-term forecast to expand coverage of
showers and thunderstorms Wednesday to most of western and west-
central Nevada.
Cumulus have sprung up in the Sierra from Lake Tahoe south and
over the higher terrain of eastern Mono, southern Lyon, and western
Mineral counties, with isolated thunderstorms recently initiating
over Alpine and northern Mono counties. A weak upper-level wave
combined with very warm temperatures is expected to generate a
sufficient amount of instability and lift for isolated thunderstorms
this afternoon and evening in far western Nevada, as well as
eastern California south of Susanville. Farther north has a larger
bust potential with a rather anemic model/ensemble potential for
showers and thunderstorms, especially north and east of Susanville.
Impacts from any thunderstorms today include: brief heavy rain
with rapid temperature drops, small hail, gusty outflow winds, and
some cloud-to-ground lightning strikes. For more details of any
fire concerns, see the fire discussion below.
Wednesday will be similar to today in terms of the heat; however,
westerly winds are forecast to be stronger across the region thanks
to increased thermal gradients with a trough moving into the Pacific
Northwest. These winds are expected to bring enhanced convergence
for focusing showers/thunderstorms across northern Lassen and
Washoe counties, as well as for the Sierra Front of western NV.
Between mid-afternoon and evening, coverage looks to spread out
into west-central and central Nevada basin and range as the trough
digs southeastward. The HRRR is hinting at the potential for
stronger thunderstorms with heavier rainfall in western and west-
central NV as compared to today. This makes sense conceptually
with stronger lower-level focus for deep convection with the
westerly wind push. Fortunately, storms are likely to be moving
faster than today so concern remains low for flash flooding outside
of sensitive spots such as in and near burn scars in steep terrain.
By Thursday, temperatures are expected to be a few degrees cooler
with more of a northerly flow. A slight chance of thunderstorms
is also possible for the southern portions of Mineral and Mono
counties but confidence remains low. -Snyder/LaGuardia
LONG TERM...Friday through early next week...
After some cooling Thursday, high temperatures rise ~3-6 degrees
Friday as high pressure briefly builds overhead. Highs are expected
to top out in the 90s to low 100s for lower valleys, with 80s for
most Sierra valleys.
Saturday afternoon through Sunday, attention turns to the wind as
a system slowly dropping south from the Pacific Northwest pushes
a notable cold front through the region. Timing of the front currently
varies between late Saturday night-Sunday morning and Sunday evening.
With this in mind, the strongest winds of the weekend may be Sunday
with west wind gusts over 40 mph near and south of I-80. However,
a faster progression would see stronger winds Saturday afternoon
and evening with lesser (but still notable) northwest winds Sunday.
The winds will definitely be a fire weather concern; see the fire
discussion below for more details.
Temperature-wise, a substantial cool down to below normal temperatures
is becoming increasingly likely as the aforementioned system hangs
around the West. While it is not currently mentioned, there is
also a lower end chance for showers and thunderstorms by Monday
and Tuesday although that will be dependent on how far south the
upper low drops. If it remains near the Nevada/Oregon border
chances would likely be restricted to far northern NV/CA; if the
low drops farther into Nevada, convection chances will increase
down to around Hwy 50. -Snyder
AVIATION...
Thunderstorms are developing this afternoon along the Sierra from
approximately just north of KMMH to near KTVL, starting around 21z.
Storms are likely to continue north and eastward from late afternoon
and into the evening but will be more isolated in coverage. Brief
periods of heavy rainfall could lower ceilings and visibility and
also obscure terrain. Other concern will be gusty outflow winds
from any storms that develop, with erratic gusts of 40-50 mph
possible. Storms should diminish between 03-05z.
Chances / timing for storms today at area terminals:
KRNO: 20% / 00z-04z
KCXP: 20% / 23z-04z
KMEV: 25% / 23z-04z
KTRK: 15% / 23z-02z
KTVL: 30% / 22z-02z
KMMH: 15% / 21z-01z
Additional thunderstorms are possible on Wednesday, with the main
focus along the Sierra Front of Western Nevada northward into
northern Washoe County, spreading into central and eastern Nevada
into the evening. Storms look less likely for Thursday, with just a
stray thunderstorm possible in the Eastern Sierra and most of the
activity shifting into central and eastern Nevada.
Strong and gusty winds are looking possible this coming weekend
so if you have flying plans check back for additional details.
-Dawn
FIRE WEATHER...
** Thunderstorms today and Wednesday, strong winds possible this
weekend**
Storms are developing this afternoon as expected with little
appreciable change to the forecast. Scattered to isolated
thunderstorms along the Southern Sierra Front, with more isolated
coverage expanding north and eastward into the late afternoon and
early evening. Storm movement will be quite slow, but the lower
levels of the atmosphere remain rather dry. While rain is anticipated
under thunderstorm cores, dry strikes are certainly possible given
the dry sub cloud layer.
Wednesday, a weak trough passage will help provide better
convergence for storm development in Northern Washoe County, with
the main focus late in the afternoon into the early evening.
Otherwise, additional storms along the western Nevada Sierra Front
tomorrow afternoon will be pushed eastward as the westerly flow
increases. Storms will be moving faster than today, but motions
still only look to be around 15 mph. A blended guidance approach
is showing a 10-15% chance of dry strikes outside of thunderstorm
cores. However, with increasing moisture values, feel that the
overall rain footprint will be large enough to mitigate the need
for any Red Flag Warnings.
A few storms may linger on Thursday in the Eastern Sierra, but will
be isolated in coverage with the bulk of the activity shifting
into easter Nevada.
Looking ahead, a big concern will be strong and gusty winds this
coming weekend. Ensemble guidance suggests on Saturday and/or Sunday
we could see gusts in excess of 40 mph ahead of a strong cold front.
We are likely to see heightened fire danger due to winds and low
humidity which could exacerbate any holdover fires from lightning.
-Dawn
&&
.REV Watches/Warnings/Advisories...
NV...None.
CA...None.
&&
$$
For more information from the National Weather Service visit...
http://weather.gov/reno