Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 04/30/25
Area Forecast Discussion
National Weather Service Austin/San Antonio TX
624 PM CDT Tue Apr 29 2025
...New AVIATION...
.SHORT TERM...
(Tonight through Wednesday night)
Issued at 138 PM CDT Tue Apr 29 2025
Key Messages:
- Level 1 of 5 risk for an isolated severe storm into tonight
near Val Verde County.
- Level 1 of 5 risk for isolated severe storms across the Hill
Country, and locations along and to the east of the I-35
corridor on Wednesday
A mesoscale convective vortex (MCV) had developed overnight that
advanced across Val Verde county producing wind damage quickly
decayed this morning with a few lingering light showers over the
Hill Country. This created gustiness and shifts in the winds into
this morning as well with a wake low. Since then, winds have become
breezy and have dominantly returned out of the south-southeast. This
morning also saw some showers along the border with the CRP CWA and
a shower or two does remain left over with this layer of mid-level
moisture near Karnes county. The rest of this afternoon and tonight
will primarily remain rain free. The only exception will be along
the Rio Grande where isolated convection develops across Mexico
along the southern extension of the dryline from late this afternoon
through this evening. An isolated storm or two could make a run to
cross the Rio Grande. If a storm is able to make it, it could be
strong to severe, especially in Val Verde County. The main hazards
would be large hail and strong winds. The activity will likely
quickly fade later into the night and with any farther eastward
advancement.
An upper level low will advance across the Texas panhandle into the
western Oklahoma region from Wednesday into Wednesday night. This
helps the dryline advance farther eastward towards the highway 281
corridor by the afternoon. Greatest forcing will exist across the
San Angelo and Fort Worth CWAs with the closer proximity of the
parent low. This is where the greatest chances for storm initiation
and severe weather will exist. Across our region, the threat will
remain more conditional and dependent on the strength of the local
capping inversion. The HRRR and NAMNest had backed off with storm
development across our region through Wednesday afternoon/evening
while other short term HREF members, such as the RRFS, WRF-ARW, and
FV3, develop isolated to widely scattered thunderstorms of around
the I-35 corridor. The latest convective outlook for Wednesday into
Wednesday night showcases a level 1 of 5 risk for severe storms from
the Hill Country eastward through the I-35 corridor and continues
eastward into the coastal plains. If storms do fire, there is plenty
of instability pooling ahead of the dryline with 2500 to 3500 J/kg
of MUCAPE coupled with 35 to 45 kts of 0-6 km layer shear, and steep
mid-level lapse rates between 7 to 8 C/km for where storms could
become severe. Large to very large hail and damaging winds are the
primary hazards. Locally heavy rainfall may be possible with the
activity as well. This activity, if develops, could impact the
afternoon/evening commute, before fading/dissipating by the
overnight. Other than this thunderstorm potential, there could be
spotty to scattered low topped showers that develop underneath the
capping inversion from Wednesday morning into the afternoon as well
for locations that remain east of the dryline. Locations that are
west of the dryline will see sunny conditions with less wind and
lower humidity levels. Overall, even with that said, the PoPS were
lowered into the 30 to 50 percent range for locations east of
the dryline given the conditional thunderstorm potential.
Afternoon highs today will range from the mid 80s into the mid 90s
along the Rio Grande. For Wednesday, highs will trend similar for
locations remaining to the east of the dryline but hotter for
locations that are west of the dryline with the drier air. The Rio
Grande could make a run for 100 degrees during Wednesday afternoon
as a result. Overnights will remain very warm and muggy as values
each night range from the 60s into the low 70s. This includes
Wednesday night through early Thursday morning with the dryline
retreating back westward through the night.
&&
.LONG TERM...
(Thursday through Tuesday)
Issued at 138 PM CDT Tue Apr 29 2025
Key Messages:
- Hot and humid conditions expected Thursday afternoon with heat
indices in the mid to upper 90s for most.
- Multiple rounds of rain and storms are expected, with the threat
for locally heavy rainfall that could lead to flooding most likely
on Friday/Friday night.
An active period of Spring time weather continues for South Central
Texas as we enter the first couple days of May. You`ll most certainly
notice a climb in humidity, particularly on Thursday when temps will
climb into the upper 80s to lower 90s, but with dewpoints in the
upper 60s to lower 70s, it`ll make it feel like the mid to upper 90s
Thursday afternoon. A dryline will attempt to work eastward Thursday
afternoon and some strong to severe storms may develop along this
boundary Thursday afternoon and evening over the Rio Grande Plains
and make their way eastward. Notable differences in the strength of
a lead shortwave Thursday afternoon between the GFS and ECMWF will
make a big difference in storm intensity and ability to move
eastward. With the strength of the shortwave on the GFS, storms would
likely maintain strength and push eastward off the mountainous
terrain of northern Mexico and into South Central Texas. The ECMWF
version leaves a bit more to be desired with a weaker shortwave and
storms struggling to move east. For now, SPC has a Marginal (Level 1
of 5) Risk for severe storms over a good chunk of our region. Any
storms that do form would have the chance to produce large hail and
damaging winds, but would have a hard time getting much further east
than the Highway 281 corridor.
Our attention then turns to the next shot at rain and storms on
Friday. A frontal boundary that has been stalled out over north Texas
will begin moving southward in response to an approaching upper level
low over the Four Corners. This will send the front into South
Central Texas Friday Afternoon and evening. Where heavier rain sets
up in highly dependent on the location of the frontal boundary. With
PWATs some 1-2 SD above the mean in the ECMWF Ensembles, and rich
moisture from the surface to about 700mb, locally heavy rainfall that
could lead to flooding or flash flooding is possible if storms can
linger long enough. If the front pushes too far south too quickly,
amounts will be lighter. For now, there also appears to be a low end
risk for severe storms, but the greater threat looks to be heavy
rainfall. WPC has highlighted most of our area in a Day 3 Marginal
(Level 1 of 4) Excessive Rainfall Outlook. This could eventually be
upgraded to a Slight risk, but confidence in location and timing of
the heavier rainfall is low right now.
Saturday and Sunday, temperatures should be cooler but we won`t see a
significant drop off in humidity. Highs should still top out in the
upper 70s to lower 80s both days. Scattered showers and occasional
thunderstorms remain possible both days as broad east-southeasterly
flow continues to provide isentropic ascent behind the frontal
boundary. Weak mid-level ridging develops late Sunday in advance of
the next storm system approaching from the west. Medium range
guidance starts to diverge on the evolution of this storm system for
early next week. For now, the threat for continued rain and storms is
in the forecast, and potential for additional beneficial rainfall
remains on the table for the second week of May.
&&
.AVIATION...
(00Z TAFS)
Issued at 624 PM CDT Tue Apr 29 2025
15-20 kt SE winds continue across most of the region but will lessen
to around 10 kt tonight for most sites. Isolated TS northwest of DRT
and over Mexico have shown a gradual weakening trend and are
expected to continue decaying. MVFR ceilings return overnight
through Wednesday morning at the I-35 TAF terminals (AUS, SAT, SSF)
before ceilings lift to VFR by 16-17Z. PROB30 for TSRA at AUS and
SAT between 21-00Z have been maintained due to possible isolated
coverage of TS. Winds remain southeasterly for most areas except for
DRT, ECU and vicinity which should see a shift to west or west-
northwest winds after 15Z.
&&
.PRELIMINARY POINT TEMPS/POPS...
Austin Camp Mabry 72 87 70 93 / 10 40 40 20
Austin Bergstrom Intl Airport 72 87 70 92 / 10 40 40 20
New Braunfels Muni Airport 72 87 71 93 / 10 40 30 20
Burnet Muni Airport 70 85 68 92 / 10 50 40 10
Del Rio Intl Airport 73 98 70 98 / 20 10 10 30
Georgetown Muni Airport 71 86 69 92 / 10 50 40 20
Hondo Muni Airport 71 92 68 93 / 10 30 20 20
San Marcos Muni Airport 71 87 70 92 / 10 40 30 20
La Grange - Fayette Regional 73 87 72 90 / 10 40 30 20
San Antonio Intl Airport 72 88 71 91 / 10 40 30 20
Stinson Muni Airport 73 90 72 93 / 10 40 20 20
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
Short-Term...Brady
Long-Term...MMM
Aviation...Tran
Area Forecast Discussion
National Weather Service Goodland KS
521 PM MDT Tue Apr 29 2025
.KEY MESSAGES...
- Hazardous weather is not anticipated through the duration of
the work week.
- Long range guidance indicates a transition to an active/
dynamic synoptic pattern this weekend, a pattern often
associated with severe weather outbreaks on the High Plains.
Residents and travelers are encouraged to monitor the forecast
as the week progresses.
&&
.SHORT TERM /THROUGH FRIDAY NIGHT/...
Issued at 155 PM MDT Tue Apr 29 2025
Features of Interest:
[1] A compact upper level low situated over Arizona this
afternoon will track eastward across the southern Rockies
(tonight) and Southern Plains (Wed), then lift ENE across the
Central MS River Valley (Wed night).
[2] Shortwave energy located over northern portions of
Washington State/Idaho (this afternoon) will slowly track ESE
across the northern Rockies (tonight), central/eastern Montana
(Wed) and Dakotas (Wed night).
[3] Shortwave energy presently rounding the base of an upper
level low in the Gulf of Alaska will dig SSE through British
Columbia and Alberta (Wed), Saskatchewan (Wed night) and the
Dakotas (Thu).
Today-Tonight: A cool/stable airmass (deposited in the wake of
yesterday`s cold frontal passage) will undergo modification
tonight as surface high pressure shifts east toward the MS River
Valley and a modest southerly return flow regime ensues over
the Central Plains. Convection allowing guidance suggests that
scattered convection may develop overnight (~06-12Z Wed) in
central-southern KS.. where low-level moisture advection (850 mb
dewpoints 8-10C) beneath a modified elevated mixed layer
(700-500 mb lapse rates ~7.5 C/km) will facilitate nocturnal
destabilization in the presence of modest sloped ascent /low-
level warm advection/. Simulated reflectivity forecasts via
current and recent runs of the HRRR suggest that convection
(mainly showers) will largely be confined east of Hwy 283 (east
and/or south of Hill City).
Wed-Thu: Challenging precipitation forecast. Upper level
forcing with Features 1/2 will largely pass south/north of the
Tri-State area. A rain cooled airmass emanating from upstream
convection in Wyoming and western Nebraska will surge southward
through the Tri-State area Wed evening, the leading edge of
which will manifest as a northerly wind shift and effective cold
frontal passage. Low-level convergence with this feature could
aid in the development of scattered shower/storms Wed evening
(~00-06Z Thu). Low confidence in convective coverage. Severe
convection is not anticipated.
Fri: Guidance suggests that an upper level trough will amplify
over the Upper Midwest/Upper MS River Valley (Fri) after Feature
3 constructively interferes with Feature 2 over the Northern
Plains (Thu night) -- and that the Tri-State area will be
situated on the subsident western fringe of the amplifying
trough. Expect dry conditions.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
Issued at 155 PM MDT Tue Apr 29 2025
Long range guidance indicates a transition to an active/dynamic
synoptic pattern this weekend.. in the form of a large/broad
upper level low that progresses slowly east across the
Intermountain West/4-Corners and Rockies.. a pattern often
associated with severe weather outbreaks in the High Plains. Low
confidence in forecast specifics at this range. Expect breezy
to strong south winds and above average chances for
precipitation.
&&
.AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/...
Issued at 504 PM MDT Tue Apr 29 2025
VFR conditions are forecast to begin the period but am
forecasting MVFR conditions to move into the eastern portions
of the area; highest confidence is at KMCK but may approach
KGLD. May need to add into some for KGLD if confidence
increases. Am also watching for some potential showers and
perhaps some thunder to develop around 06Z but confidence is low
on the coverage so will monitor for potential AMD.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...None.
CO...None.
NE...None.
&&
$$
SHORT TERM...Vincent
LONG TERM...Vincent
AVIATION...Trigg
Area Forecast Discussion
National Weather Service Indianapolis IN
919 PM EDT Tue Apr 29 2025
.KEY MESSAGES...
- Becoming Partly Cloudy. Cooler tonight.
- Isolated to scattered showers and storms in far SW and southern
Indiana tomorrow evening.
- Additional chances for isolated severe on Thursday as well.
&&
.FORECAST UPDATE...
Issued at 919 EDT Tue Apr 29 2025
Surface analysis this evening shows a cold front has exited Central
Indiana, stretching across Western OH to Eastern KY. High pressure
was found to the northwest. Cooler and less humid westerly flow was
in place across much of Central Indiana. The thunderstorm complex
that impacted the area earlier today has drifted east. A few
lingering showers within the wake of the storms were exiting eastern
Central Indiana. GOES16 imagery showed clearing skies building
across the western half of Central Indiana. Aloft, a nearly zonal
flow was in place.
Subsidence is expected overnight as models suggest weak ridging
building aloft as surface high pressure moves across the Great
Lakes. This will result in the quick development of cool, easterly
flow across Central Indiana. Overall this will lead to decreasing
cloudiness overnight as precipitation will not be expected. HRRR
suggests lows in the upper 40s north to lower 50s south, which
appears on target given the cooler easterly flow.
&&
.SHORT TERM (This evening through Wednesday)...
Issued at 302 PM EDT Tue Apr 29 2025
Active weather continues through the next 24-30 hours with multiple
rounds of storms expected to impact Central Indiana, a few of which
could be strong to severe.
This evening and tonight
Satellite and radar imagery as of 230 PM EDT show a cluster of
thunderstorms along the Mississippi river pushing east-northeast
into South Central Illinois. The environment ahead of these storms
and into Central Indiana remains conducive for these storms to
sustain themselves and remain strong to severe through the rest of
the afternoon and evening hours. The region remains entrenched
within the warm sector of a low pressure moving through the Great
Lakes with strong moisture advection northward, making for an
airmass more like July than late April with dew points approaching
70 degrees. Unidirectional 30-45kt southwesterly bulk shear
through the column and effective helicity of 100-200 m^2/s^2
within a humid, unstable environment will support lines of storms
and bowing segments with this next round. RAP Mesoanalysis shows
increasing DCAPE within this few hour dry slot as temperatures
make a run for 80 degrees, slightly increasing the low level dew
point depression increasing damaging wind potential. Expect
storms to traverse eastward across Indiana from the 330pm-6pm
timeframe. The best threat for severe weather looks to be along
and south of a line from Sullivan County, IN to Bloomington to
Greensburg. Lower confidence exists on the northern extent of the
severe weather based on the trajectory of the complex in
Missouri.. But with the atmosphere recovering nicely within this
dry slot, the severe weather threat may extend further north
toward the I-70 corridor. Will be watching this closely this
evening. For now, South Central Indiana has the greatest threat of
severe weather with damaging wind gusts and isolated tornadoes.
Cold front pushes from north to south through Central Indiana within
the 9 PM to 2 AM timeframe, switching winds around to the north and
advecting a drier airmass into the state. This front is likely to
stall out along or south of the Ohio River overnight. Light winds
behind the front and nearly saturated boundary layer may lead to
areas of fog overnight along and north of the frontal boundary.
Confidence is low as dry air advection may keep dew point depressions
large enough to inhibit fog development; however wind sheltered areas
and valleys would have the best chance for any fog. Cold air advection
behind the front will lead to lows ranging from the mid 40s to
mid 50s across Central Indiana.
.Wednesday
The aforementioned cold front from the previous day hangs around
the Ohio Valley much of the day Wednesday, slowly pushing north into
Central Indiana as a warm front by the evening. With the front south
of Central Indiana for at least the first half of the day, expect
fairly benign conditions to begin the day. Mid to high level clouds
will be streaming in from the southwest over the front; but overall
a drier and cooler airmass with highs in the mid 60s to mid 70s are
in the forecast for Wednesday.
Focus shifts to Wednesday evening as the front pushes northward into
South Central Indiana. While the best forcing for ascent will be further
west along the cold front, there may be enough lift over the front
and moisture advection northward for an environment supportive of
scattered convection along and south of the boundary. There are a
few aspects of tomorrow evenings set working for severe weather and
few working against, which should keep the overall coverage of storms
down. Parameters working for severe weather will be backed surface
winds along and south of the front, increasing instability values,
0-6 km bulk shear 35-45 kts, lift over the front, and elongated
hodographs indicating an environment conducive for a few discrete
supercells. Factors working against severe weather and lowering
confidence tomorrow evening are the potential for weak mid level
lapse rates, speed at which the warm front moves potentially keeping
greatest instability south, and weaker low level shear. While the
threat is marginal, the areas to watch tomorrow are along a line
and south of Sullivan to Bedford to Seymour. Most locations north
of this line, including the I-70 corridor, Indy Metro and points
north may be mainly dry Wednesday, with the best chance for any
storms into the overnight hours and Thursday morning.
There likely will be a strong south-north humidity and temperature
gradient across the state with warmest areas in the 70s in Southern
Indiana where the storm threat is. Mid 60s to low 70s likely north
of the boundary.
&&
.LONG TERM (Wednesday night through Tuesday)...
Issued at 302 PM EDT Tue Apr 29 2025
The first part of the long term period will continue to see chances
for showers and thunderstorms, with some storms potentially being
severe, as a boundary with SW flow lingers over the region. This
weekend and beyond will then see sunny and quiet conditions as upper
ridging and high pressure settle in.
A short wave will start to move through Wednesday night with an
additional surge of showers and storms passing through central Indiana.
Cant rule out a few of these storms to still be potentially
severe, lingering from the afternoon storms. The arrival of stronger
850mb flow Wednesday night will increase convective coverage and enable
deeper low level moisture to return into central Indiana. Strengthening
low pressure will track from the Missouri Valley into the Great Lakes
Thursday with a noted increase in 850mb flow late day immediately
ahead of the approaching cold front. The larger surface low will continue
to slow push eastward through the day Thursday which will again see
the potential for a few storms again being severe as storms pass
through. Again, chances for showers will continue into Friday as an
additional short wave passes through the larger stalled trough,
but at this time not expecting severe with this wave.
Going into the tail end of the week and weekend, upper ridging will
progress, finally pushing the stalled system off to the east. This
replace the stormy pattern for a quiet and sunny system. Expect the
remainder of the long term period to fluctuate around normal
temperatures.
&&
.AVIATION (00Z TAF Issuance)...
Issued at 630 PM EDT Tue Apr 29 2025
Impacts:
- MVFR to IFR vsbys at BMG and IND through 03Z with brief TSRA
- MVFR cigs after 19Z tomorrow
- Brief MVFR to IFR vsbys in convection tomorrow
- Wind shift to the northeast tonight, easterly tomorrow
Discussion:
Convection is expected to continue at IND and BMG through 03Z with
frequent MVFR and occasional IFR vsbys. Brief TSRA is possible but
lightning will become increasingly isolated after 00Z. VFR
conditions are then expected through the night and into early
tomorrow morning before rain chances begin to increase after 12Z
with greatest coverage during the afternoon and evening. Cigs will
become predominately MVFR after 18Z with generally VFR vsbys. Brief
MVFR to IFR vsbys in the heaviest showers/storms of the afternoon.
Winds will generally remain westerly at 8-12 kts through the evening
before becoming northeasterly after 04Z tonight and easterly
tomorrow morning.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
Update...Puma
SHORT TERM...CM
LONG TERM...KF
AVIATION...White
Area Forecast Discussion
National Weather Service San Francisco CA
Issued by National Weather Service Eureka CA
845 PM PDT Tue Apr 29 2025
...New AVIATION, MARINE...
.SYNOPSIS...
Issued at 218 PM PDT Tue Apr 29 2025
Another fair weather day across the board today. Nice again
tomorrow with a slight chance for very isolated showers and
thunderstorms (see discussion for more targeted info). Otherwise
quiet conditions remain until the weekend where we can expect
soggy conditions along with gusty winds.|
&&
.SHORT TERM...
(This evening through Wednesday)
Issued at 218 PM PDT Tue Apr 29 2025
Splendid day today with nearly cloudless skies, sans a few areas
along the immediate coast. Temperatures as expected today with
temperatures ranging from the upper 60s to upper 70s. Some
locations along the coastline held on to marine stratus for a bit
longer today, so these locations are just getting out of the upper
50s as of writing. Shifting focus a bit to tomorrow since there
some more interesting things to talk about. A subtle upper level
trough is progged to move through the region tomorrow which will
bring a low chance of very isolated showers and thunderstorms to
the North Bay and areas near Monterey and San Benito counties in
the vicinity of the Gabilan Range. Cold air advection in the upper
levels with the passage of the trough and hi res guidance
depicting sufficient low level moisture advection result in
moderate instability of ~1,000 J/Kg. Rather impressive for this
time of the year, but not unheard of. Areas of interest in this
event would be favored areas of terrain-enhanced convection, such
as interior portions of the North Bay and the interior Central
Coast along the Gabilan Range. Limiting factors for severe modes
will be the relative lack of a lifting mechanism and overall low
degree of instability throughout the layer (slightly unstable
through a deeper column as opposed to highly unstable through a
shallower column). Should our available instability be realized
through lifting via diurnal heating over these isolated terrain
areas, we could see brief heavy showers and perhaps some small
hail...again emphasizing isolated to the aforementioned areas.
&&
.LONG TERM...
(Wednesday night through next Monday)
Issued at 218 PM PDT Tue Apr 29 2025
Once again not much to talk about between Wednesday and Friday,
so shifting focus to the weekend. We have increased attention
towards the weekend event regarding windy conditions. A deep upper
low progged to enter the NEPac by Friday afternoon will bring
quite a contrast to what we are going through mid-week. Increased
cloudiness and breezy conditions will begin affecting the region
late Friday. Winds increase on Saturday as a stout 75-80 kt 500 mb
jet streak digs south along the West Coast. Behind the cold front
we can expect wind gusts into the 40-50 mph range across some of
the high coastal terrain. Ensemble forecast tools corroborate this
with the ECMWF extreme forecast index showing a good agreement of
model members well above climatology and cluster analysis
advertising solid agreement in the overall pattern. As such, winds
have been nudged toward the 75th percentile in the forecast for
late Friday night through Sunday. Judging based on the forecast
trend, winds could be adjust higher in future forecast packages if
the trend continues. Keep up with the latest forecasts for the
most up to date information as the timeline moves closer.
&&
.AVIATION...
(00Z TAFS)
Issued at 845 PM PDT Tue Apr 29 2025
The marine layer depth varies from 800 to 1000 feet. Coastal
stratus and fog /MVFR-IFR-LIFR/ will continue tonight and
Wednesday morning with local inland intrusions of stratus and fog
due to onshore winds. Sea surface temps 49F to 54F are running in
good contrast to lower level temperatures in the 60s, both Fort
Ord and Point Sur show a well developed lower level temperature
inversion. Adding complexity to the forecast, a 500 mb trough
(with near late April normal height and temp) arrives tonight and
Wednesday with a reflection of weak cyclonic circulation
developing at 850 mb and 925 mb early Wednesday within the lower
level temperature inversion/lower level thermal ridging. Light
offshore winds aloft North Bay will sustain the lower level warmth
and stability, while onshore winds to the south will slowly erode
the lower level warmth and stability, deepening the marine layer
but perhaps not fully eroding the lower level warmth Wednesday.
Best chance for afternoon convection will be inland, however there
may be enough residual lower level warmth i.e. stability and/or
surface cooling depending on extent of inland marine air intrusion
limiting surface convective temperature. Based on NAM, HRRR
convective parameters and global model QPF and precipitable water
there will be potential for a few inland showers/downpours; at
this time not expecting any impacts to our forecast area airport
terminals.
Vicinity of SFO...VFR, onshore wind through the period. Low
confidence MVFR ceiling Wednesday morning, if the marine layer
deepens there`s a better chance of a stratus ceiling.
SFO Bridge Approach...Similar to SFO.
Monterey Bay Terminals...IFR-LIFR due to stratus and fog, however
with the development of a weak cyclonic circulation in the lower
levels beginning early Wednesday morning, onshore winds through a
greater depth as well as weak cooling will deepen the marine layer
in this area. May need to adjust TAFs to reflect IFR gradually
lifting to MVFR early Wednesday, with subsequent mixing out to VFR
likely by late morning or early afternoon.
&&
.MARINE...
(Tonight through next Monday)
Issued at 712 PM PDT Tue Apr 29 2025
Northerly flow will persist thanks to high pressure anchored to
the west. Winds will be locally stronger, especially over the
outer waters leading to hazardous conditions for smaller craft
through Wednesday. Moderate seas and moderate northwesterly
breezes will prevail Thursday and Friday. Strong northwesterly
breezes and rough seas return Saturday to the outer waters.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...Small Craft Advisory until 9 AM PDT Wednesday for Pt Arena to Pt
Reyes 0-10 nm.
Small Craft Advisory until 3 AM PDT Thursday for Pt Arena to Pt
Reyes 10-60 NM.
Small Craft Advisory until 3 PM PDT Wednesday for Pigeon Pt to
Pt Pinos 10-60 NM.
&&
$$
SHORT TERM...Behringer
LONG TERM....Behringer
AVIATION...Canepa
MARINE...MM
Visit us at www.weather.gov/sanfrancisco
Follow us on Facebook, X, and YouTube at:
www.facebook.com/nwsbayarea
x.com/nwsbayarea
www.youtube.com/nwsbayarea
Area Forecast Discussion
National Weather Service Pendleton OR
443 PM PDT Tue Apr 29 2025
.UPDATED AVIATION DISCUSSION...
.AVIATION...00Z TAFs...VFR conditions for all sites during this
period with KALW having light winds. However, sustained winds of 12-
20 kts with gusts at 20-30 kts will prevail for KDLS, KPDT, KRDM,
KBDN, KYKM, and KPSC during this evening. Otherwise, winds will
decrease tonight. Feaster/97
&&
.PREV DISCUSSION... /issued 307 PM PDT Tue Apr 29 2025/
.SHORT TERM...Tonight through Thursday night...Key Messages...
- Warmer and drier after today with highs peaking 10-16 degrees
above normal with upper 70s and lower 80s Thursday.
- Breezy to locally windy this afternoon with the highest gusts
in the Kittitas Valley, as high as 45 mph.
Limited sensible weather concerns in the short term. Latest radar
display shows little in the way of precip anymore with no sites
reporting and little in the way of returns except for over Union
county. Latest Day Cloud Phase RGB imagery shows stratocu across
the eastern mountains with cirrus across much of south central WA
and northern OR. Latest water vapor imagery shows upper ridging
upstream in the eastern North Pacific with westerly cyclonic flow
aloft overhead with a disturbance apparent in northeast WA and
another upstream in British Columbia. The aforementioned upper
ridge will be building over the next 24-hrs into the Pacific NW
and will be over the interior NW by Thursday. In the meantime,
under this west/northwest flow regime in tandem with a weak
disturbance upstream, may see some sprinkles/slight chance
showers across the eastern Lower Basin into the northern Blues
this afternoon. Confidence is low (10-30%) with a fair agreement
among CAMs, of which HRRR has been showing this signal the last
six runs. Little to no impacts expected nonetheless with limited
and shallow instability thus no thunder mention. Otherwise, no
change in the wind advisory. Current thinking is this should be a
marginal event for the Kittitas Breezy way with peak gusts 40-50
mph owing to the pressure gradient and available guidance.
Northwest flow takes more of a hold with clearing skies overnight
in tandem with winds decreasing that could be attributable to
winds lessening in the lower troposphere and a weakening pressure
gradient. Lighter winds, generally terrain driven, expected
tomorrow as surface pressure differences weaken in tandem with
light 700 and 850 hPa winds in place. With the warming trend
underway Wednesday, the warmest conditions are expected Thursday
with highs in the upper 70s and lower 80s in lower elevations,
10-16 degrees above normal. This will coincide with light winds
and mostly sunny skies.
.LONG TERM...Friday through Tuesday...Main weather concerns will
revolve around an upper trough crossing the area Friday afternoon
through Sunday bringing a chance of rain and breezy to windy
conditions to the area Friday night through Saturday evening. An
upper low will develop in the base of the trough and pass to our
south Saturday night and Sunday which will continue light rain over
the eastern mountains wile the rest of the area dries out. Monday
will see a ridge building that keeps us dry through Tuesday. Model
ensembles are in good agreement about the above scenario with only
minor differences about the strength of various features through
Monday. By Tuesday, 60 percent model ensemble members (especially
the ECMWF) favor continued ridging while the other 40 percent
(especially the GFS) want to bring another trough towards the
Pacific Northwest coast.
The Extreme Forecast Index Highlights QPF Friday night and Saturday
with a value of 0.76 focused over central and north central Oregon
and the Ochoco Mountains. It also has a Shift of Tails over that
area indicating that some members have more extreme rainfall
amounts, so rain amounts could be higher if these minority members
are correct. Temperatures Friday and to a lesser degree on Saturday
are highlighted with a value of 0.89 and quite a few lower elevation
locations are expected to be in the 80s on Friday. Finally, winds
Saturday through Monday are highlighted with values of 0.80 to 0.87
and breezy to windy conditions are forecast on those days with wind
highlights possible through the Cascade gaps Saturday afternoon.
Overall forecast confidence is good.
Friday will see increasing clouds and instability as an upper trough
sends a southwest flow into the area. This will warm temperatures
about 5 degrees from Thursday with highs in the lower to mid 80s in
the lower elevations and mainly 70s in the mountains. In the late
afternoon, clouds will increase and rain showers will start in
central Oregon and spread north through the night. Due to the
instability, have kept a slight chance of thunderstorms over central
and north central Oregon and the Ochoco Mountains in the late
afternoon and early evening. Rain amounts will be up to a third of
an inch in the south but dropping off to less than a tenth of an
inch in the Columbia Basin. Tightening pressure gradients will bring
breezy west to northwest winds of 15 to 20 mph in the afternoon.
Saturday will see a closed low form in the base of the trough and
move into northern California. Circulation around the low will keep
showers of around a tenth of an inch going in the eastern mountains
while the rest of the area dries out. It will be much cooler with
temperatures down as much as 20 degrees from Friday with highs in
the 60s in the Columbia Basin and in the 50s elsewhere. Winds will
be strongest Saturday with 15 to 25 mph widespread and 20 to 30 mph
in the Columbia Gorge and Kittitas Valley. Wind highlights are
possible that day.
Sunday will see the low move to near Las Vegas and a ridge building
offshore. Lingering showers in the eastern mountains will taper off
in the morning. Temperatures will rebound 3 to 5 degrees to the 60s
to lower 70s with mid to upper 50s in the mountains. The Columbia
Gorge and Kittitas Valley will again reach 20 to 30 mph but the rest
of the area will reach 10 to 20 mph.
Monday and Tuesday will remain dry with highs in the 70s while the
mountains will be in the 60s. Winds will be light with most
locations seeing no more than 10 to 15 mph each afternoon.
Perry/83
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 38 68 41 79 / 10 0 0 0
ALW 43 67 46 78 / 10 0 0 0
PSC 40 73 41 82 / 10 0 0 0
YKM 39 73 44 79 / 0 0 0 0
HRI 41 72 41 82 / 10 0 0 0
ELN 40 71 42 77 / 0 0 0 0
RDM 28 69 34 81 / 0 0 0 0
LGD 35 65 37 74 / 10 0 0 0
GCD 34 68 38 77 / 0 0 0 0
DLS 40 73 44 82 / 0 0 0 0
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...None.
WA...Wind Advisory until 8 PM PDT this evening for WAZ026.
&&
$$
SHORT TERM...80
LONG TERM....83
AVIATION...97
Area Forecast Discussion
National Weather Service Phoenix AZ
Issued by National Weather Service Tucson AZ
459 PM MST Tue Apr 29 2025
.UPDATE...Updated Aviation Discussion.
&&
.SYNOPSIS...
Dry conditions will persist through this week as temperatures warm
from near to above normal temperatures heading through the middle
and latter portions of this week. A weather disturbance moving
into region this weekend will bring another round of breezy to
windy conditions and much cooler temperatures going into early
next week.
&&
.DISCUSSION...
Early afternoon RAP analysis and WV satellite imagery show an
upper level low spinning over northern Arizona, producing showers
and isolated thunderstorms across the northern high terrain.
Meanwhile across the lower deserts, mostly clear skies are giving
way to increasing CU development around the area. Heading into
this evening this low circulation will migrate southward toward
central Arizona, which may lead to some weak showers/virga moving
off the high terrain and into the Valley. Additionally, some gusty
outflow winds will be possible with this activity with the latest
HREF supporting upwards of a 10-20% of a few outflow gusts in
excess of 35 mph. The upper low is then set to depart the state to
the east overnight.
Following the exit of the aforementioned low, transient shortwave
ridging will build into the Southwest and will promote rising
heights and warming temperatures through the latter half of the
week. Afternoon highs Wednesday will climb near to slightly above
normal as lower desert highs warm into the upper 80s to low 90s.
Thereafter, forecast highs remain steady in the lower 90s across
the lower elevations. Going into Friday, a weak Rex Block will
develop over the West as a weak troughing feature shifts over the
Desert Southwest with ridging over the Pacific Northwest. Despite
the weak low moving over the southwest CONUS, there will be very
little change in upper heights with temperatures remaining steady.
A stronger weather system will pushing into the region this
weekend.
.PREVIOUS DISCUSSION...
The evolution of this troughing pattern heading into this weekend
is coming more into focus as ensembles are now honing in better on
how deep and intense this troughing feature will become. All
ensemble members now depict some version of a cutoff low
developing by Sunday as this trough deepens into the Desert
Southwest, with just minor positional and mid-level negative height
anomaly differences through Sunday. Thus, the region can expect
the sensible weather conditions to transition starting Saturday,
where breezy to windy conditions filter in from west to east
through Sunday. Should the conditions line up right, at least
elevated fire weather conditions may become a concern on Saturday
due to the lingering low relative humidities and stronger winds
for higher terrain areas of south-central Arizona.
Due to the position of this cutoff low remaining west of the
region on Saturday, above normal temperatures are expected to
remain in place prior to a dramatic cooldown on Sunday, on the
order 10-20 degrees, depending on how strong this low becomes.
Widespread windy conditions may become a factor on Sunday as a
result, although precipitation chances continue to remain minimal
to none. Despite the pessimism on precipitation chances, there are
a couple of ensemble clusters (representing 10-15% of the
membership) that paint some light accumulations across some lower
desert locations on Sunday should the trough amplify enough to
advect more sufficient moisture into south- central Arizona.
However, current NBM PoP`s still reasonably remain at 10% or lower
Sunday onward at this time. As mentioned, temperatures are
expected to dip to below to well below normal levels (still a 5-10
degrees interquartile range) beginning on Sunday and extending
into early next week.
&&
.AVIATION...Updated at 1740Z.
South Central Arizona including KPHX, KIWA, KSDL, KDVT:
Rain-cooled outflow winds are expected to push through the Phoenix
area from the north between 00-04Z this evening, with around a
10-20% chance for wind gusts >30 kts. There is also a slight
chance for some spotty virga or a brief light shower during the
same timeframe. The gustiness following the outflow is
anticipated for at most 2 hrs and then once subsiding wind
directions will favor easterly for the remainder of the evening
and through Wednesday morning. Typical diurnal wind tendencies are
expected for Wednesday with a westerly shift by 19-20Z. FEW to
SCT clouds down to 10k ft AGL now should persist through midnight
before becoming SKC through Wednesday morning. High clouds then
move in Wednesday afternoon.
Southeast California/Southwest Arizona including KIPL and KBLH:
Gustiness at KBLH will subside over the next couple hours. Both
KBLH and KIPL will then see light winds persist through tonight
and Wednesday morning, with some periods of very light
variability. Winds at KIPL will eventually shift southeasterly by
noon Wednesday and KBLH will see gusts pick up to around 20 kts
from the SW by the afternoon. Mostly clear skies are expected
through Wednesday morning, followed by SCT to BKN high clouds for
the afternoon.
&&
.FIRE WEATHER...
Warming and drying conditions will persist through the rest of the
week with small chance of a few weak showers/virga this evening,
which could result in some gusty outflow winds. There is about a
10-20% chance of outflow gust in excess of 35 mph this evening.
Expect minimum RH`s of 10-20% to dip to 7-15% by the middle of the
week, with overnight recoveries worsening to around 25-40%. Winds
will maintain seasonally typical upslope gustiness in the
afternoon through the entire week with likely stronger gusts
arriving this weekend. A cool weather system will then approach
and move through the region this weekend. This will bring minimum
RH values back above critical levels. However, this system will
also bring increased gradient winds across the area and it looks
as though there will be a period of at least elevated fire weather
conditions for South- Central AZ Saturday afternoon. Predictive
services still show ERCs are below the 75th percentile, which
should help limit the large fire risk.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...None.
CA...None.
&&
$$
DISCUSSION...Smith
PREVIOUS DISCUSSION...Young
AVIATION...Benedict
FIRE WEATHER...Smith/Young
Area Forecast Discussion
National Weather Service Reno NV
216 PM PDT Tue Apr 29 2025
.KEY MESSAGES...
* A warming trend continues with above average temperatures expected
through Friday.
* A weak system may provide chances for afternoon showers and
thunderstorms today through Thursday.
* Another spring storm system has the potential to bring back colder
temperatures, gusty winds as well as rain and snow chances this
weekend.
&&
.DISCUSSION...
The latest RAP upper air analysis shows low pressure over northern
AZ with an upper air trough moving through north of the CWA today.
Current surface observations and satellite imagery report light
surface winds across the CWA with clouds developing over western
NV and more clouds moving across the OR border into northern
portions of the CWA. Forecast guidance shows the northern trough
stretching down over the CWA by tomorrow. This trough will then
cut off into a low over southern CA when a ridge moves over the
CWA on Thursday. On Friday, a stronger PacNW trough starts to move
towards the CWA that will change the pattern quite a bit.
Forecast guidance shows the trough cutting off into another low
over the weekend and potentially clipping the southern portion of
the CWA as it passes by.
With this pattern aloft, above normal temperatures continue
through the work week with a general warming trend. The exception
to this trend looks to be tomorrow due to a cold front passing
through the region from the north this evening. Winds pick up a
bit with gusts up to around 30 mph out of the north-northwest as
the front moves through. But tomorrow`s high temperatures will be
a few degrees cooler than today`s highs before the warming trend
continues. Western NV valleys will warm to the middle 70s by
Thursday followed by Friday`s daytime highs potentially reaching
the upper 70s. Sierra communities may see highs in the middle to
upper 60s by Friday after dropping down to between the upper 50s
and lower 60s tomorrow.
For precipitation chances today, isolated showers are seen
developing later this afternoon along the OR border and then
moving southward across the region as the cold front sweeps
through going into the night. QPF values with these showers look
to range between a trace to around 0.10 inches of liquid. Chances
that these showers can contain thunder look to be around 10-20%
later today, so brief periods of increased rainfall and gusty
outflows may be possible. Chances for precipitation look to be a
bit better (50-60%) tomorrow afternoon and evening though they
look to stay to the south of I-80. Seeing better chances (15- 35%)
for thunderstorms as well tomorrow afternoon with the best
chances in Mono, Mineral, Alpine, and South Lyon Counties. Not
anticipating severe weather at this time, but will continue to
monitor this going forward. The afternoon and evening shower and
thunderstorm chances expect to continue into Thursday though
thunderstorm chances (up to 25%) look to be the highest in Mono
County again.
As the upper air pattern changes going into the weekend, forecast
guidance shows precipitation chances becoming a bit more widespread
in coverage beginning Friday and going into the weekend. Snow levels
look to stay above 8 kft for Friday before they start to decrease
to 6.5-7 kft by Saturday evening. But the story for the weekend
looks to be another round of mountain snow and valley rain along
with cooler temperatures as low pressure moves from northern CA
into central NV. When looking at the latest NBM probabilities
for Saturday and Sunday, they are showing a 15-25% chance for 2+
inches of snow in the Tahoe region going down through Mono County
though low confidence in snowfall totals this far out continues.
The probabilistic Winter Storm Severity Index displays a 30-50%
chance of minor impacts currently for the Eastern Sierra Mountains
around pass level, so will continue to monitor this as well as
roads and surfaces could become slick with snow. The Western NV
valleys have daytime highs dropping to the middle 50s to lower 60s
on Saturday and then into the lower to middle 50s on Sunday.
Sierra Mountain communities may see highs in the 40s and 50s on
tap for this weekend with this wintry system moving through. -078
&&
.AVIATION...
While VFR conditions expect to continue this afternoon at all area
terminals, the cloud cover currently seen crossing over from OR
expects to spread across the remainder of the region going into the
evening with a cold front moving through. Chances for showers closer
to the OR border start around 21Z that will move across the region
to the south going through the night. KRNO, KCXP, KMEV, and KTRK
see around a 30% chance for brief showers after 05Z which could
cause MVFR conditions. Chances for showers and thunderstorms
expect to return tomorrow afternoon and evening generally south of
I-80 with the best chances around Mono and Mineral counties. -078
&&
.REV Watches/Warnings/Advisories...
NV...None.
CA...None.
&&
$$
AREA FORECAST DISCUSSION
National Weather Service Charleston WV
957 PM EDT Tue Apr 29 2025
.SYNOPSIS...
Strong to severe storms are possible this evening into early
tonight ahead of a cold front. Remaining unsettled through the
rest of the work week. Drying out by Sunday.
&&
.NEAR TERM /UNTIL 1 AM WEDNESDAY MORNING/...
As of 945 PM Tuesday...
The second wave of showers and thunderstorms is sweeping through
the CWA at present, with a line of thunderstorms currently
extending from Washington County (OH) southwestward to Mingo
County (WV). Thunderstorm activity has strengthened within the
last hour or so as it has moved into/across the CWA, with
forward speed increasing. The line will quickly progress
eastward across the rest of the CWA within the next hour or two.
The main hazard will be damaging wind gusts, although some
small hail will also be possible. Any severe threat quickly
diminishes following the passage of this activity, with just
isolated showers and perhaps a rumble of thunder thereafter for
the rest of tonight.
As of 630 PM Tuesday...
A Severe Thunderstorm Watch has been issued for all of eastern
Kentucky until 1 AM. Strong thunderstorms have already developed
over central Kentucky and will be moving eastward.
As of 520 PM Tuesday...
A line of scattered showers and thunderstorms has progressed
through portions of southeast Ohio over the last couple of
hours, some of which have been strong to severe. This activity
will continue to shift eastward across the northern portion of
the CWA, with the potential to bring strong wind gusts and small
hail. An isolated severe storm remains possible. Further south,
activity has been much more of the isolated variety given the
best forcing for ascent north of the area, although isolated
strong storms remain possible this evening. Another round of
more widespread strong to severe thunderstorms is expected later
this evening into early tonight as the surface cold front
approaches the area. Have updated temperatures, PoPs, wind, and
cloud cover into early tonight. The rest of the forecast
remains on track.
As of 130 PM Tuesday...
Key Points:
* Scattered clusters of strong to severe thunderstorms progress
through the area this afternoon and evening.
* Damaging wind gusts, large hail, tornadoes, and locally heavy
rainfall will be embedded within convective activity.
* Remaining unsettled on Wednesday as the cold front gets hung
up across the southern Appalachian coalfields.
After a thin strip of pop up showers sailed through the forecast
area earlier today, a brief interlude of dry weather is underway
across Central Appalachia this afternoon. Not too far off to the
west, however, lies a bowing segment of strengthening
thunderstorms crossing from Indiana into Ohio, aiming for our
far northwestern zones here in the next several hours.
A Severe Thunderstorm Watch has been hoisted for portions of
our southeast Ohio counties this afternoon into this evening to
capture the first round of convective activity slated to
progress overhead in response to an advancing cold front. Radar
trends with upstream activity depict storms moving northeast at
speeds on average of 55 to 65 miles per hour, supported by a
strong wind field out ahead of the front. This particular batch
of storms will be capable of producing damaging wind gusts on
the upwards of 70 miles per hour, large hail, and potential for
quick spin-up tornadoes within bulges of the bowing segment.
Local observations across southeast Ohio for this past hour
recorded a temperature/dew point spread in the 80s/60s,
depicting favorable destabilization under ample sunshine, which
will aid in sustaining storms as they venture further east.
Mesoanalysis shows the morning capping inversion hovering over
the forecast area has since vanished early this afternoon,
further supporting an unstable environment for storms to
capitalize on as they advance eastward.
The HRRR has done a decent job of encapsulating today`s
convective trends thus far, and suggests this first band of
storms will clip southeast Ohio and travel along the Mason-Dixon
line into the late evening timeframe. This will then quickly be
followed by a secondary line of showers and storms punching into
eastern Kentucky around 6 PM, which will be firmly nestled
along the encroaching cold front. This will yield additional
potential for all weather hazards in severe storms, especially
across locations that do not receive the first round of today`s
activity. Locally heavy downpours may also impose high water
issues in spots.
The cold front sags into the forecast area overnight, preserving
nighttime showers and possible storms heading into midweek. The
boundary is slated to drape through the southern coalfields and
become stationary on Wednesday, confining the bulk of
precipitation to areas south of the I-64 corridor. This
unsettled weather pattern then rules the roost for the second
half of the work week, with a generalized thunder risk for
Wednesday and beyond into the short term forecast period.
Temperatures will tumble down closer to normal values for this
time of year in response to the cold front`s proximity to the
area.
&&
.SHORT TERM /1 AM WEDNESDAY MORNING THROUGH FRIDAY NIGHT/...
As of 1223 PM Tuesday...
Strong thunderstorms will be possible again on Thursday as the
stalled frontal boundary lifts back to the north as a warm front.
Models are projecting 500-1,000 J/kg of CAPE building by 18Z with
weak to marginal 0-6 km shear (25-30 kts). Aside from a weak 500-mb
vort max approaching from eastern Kentucky during the afternoon,
there is not a lot of forcing expected across our region to trigger
widespread severe weather. The best forcing will be well to the
west, across Illinois, Indiana and western Kentucky ahead of a more
potent vort. max. Therefore, the overall threat for severe weather
should be low Thursday, and the more likely scenario will be garden-
variety thunderstorms across the region. A few of those storms could
contain locally damaging wind gusts.
By Friday morning, a cold front will cross the region from the west,
along with a more potent 500-mb vort. max. The threat for severe
weather is questionable, because there may not be enough time for
sufficient destabilization depending on the exact timing of the
frontal passage. Showers and general thunderstorms should be the
theme Friday, with perhaps a few of those storms containing locally
damaging wind gusts once again.
The threat of flooding looks relatively low Thursday and Friday, and
the main risk will be training thunderstorms, or if thunderstorms
move over low-lying and urban areas. A marginal risk of excessive
rainfall is currently outlooked by WPC.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
As of 1223 PM Tuesday...
A secondary cold front and a 500-mb trough axis will cross Saturday
morning with lingering showers across the region. There`s still some
uncertainty how long showers last Saturday, with some models show
drying air approaching from the west by Saturday afternoon and
others keeping a saturated low-level airmass through 00Z Sunday. We
kept likely PoPs in the forecast Saturday morning, gradually
reducing to chance PoPs by the evening.
High pressure will build back into the area Sunday with dry weather
returning. The air will feel quite cool in a postfrontal airmass
with highs only in the 60s. Monday will turn a bit milder as high
pressure expands and slides farther to the east.
&&
.AVIATION /02Z WEDNESDAY THROUGH SUNDAY/...
As of 810 PM Tuesday...
Strong to isolated severe thunderstorms are possible this
evening into early tonight ahead of an approaching cold front.
Scattered showers and thunderstorms are just now entering the
far western portion of the forecast area, and will gradually
shift east throughout the evening into tonight. Strong wind
gusts, small hail, and locally heavy rain are all possible.
Activity will become confined in/near the mountains later
tonight, gradually becoming more of the isolated variety.
IFR/MVFR VSBY is expected with this activity, along with a
gradual reduction in CIGs to MVFR and perhaps IFR later tonight
with stratus. Some patchy fog development could also occur later
tonight resulting in MVFR VSBY, particularly if any breaks in
the clouds develop. Given low confidence, this has largely been
left out of the TAFs.
Isolated showers and a few storms are possible on Wednesday
across southern WV and southwest VA as a frontal boundary
lingers across the area, with mainly dry weather expected
elsewhere. Brief MVFR VSBY restrictions could occur at BKW.
IFR/MVFR CIGs at dawn across much of the area will gradually
lift to VFR area-wide by mid/late afternoon.
Southwest flow this evening will gradually veer to N or NNE
overnight for areas north of the front. Light and variable flow
is expected during the day on Wednesday across the region.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z THURSDAY...
FORECAST CONFIDENCE: Medium.
ALTERNATE SCENARIOS: Timing/intensity of restrictions overnight
into Wednesday morning with showers/storms and low stratus could
vary from the forecast. Fog development overnight could be more
extensive then currently anticipated.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE WED 04/30/25
UTC 1HRLY 00 01 02 03 04 05 06 07 08 09 10 11
EDT 1HRLY 20 21 22 23 00 01 02 03 04 05 06 07
CRW CONSISTENCY H H L M H H H H H H H H
HTS CONSISTENCY H M M H H H H H H H H H
BKW CONSISTENCY H H H M H H H H H H H H
EKN CONSISTENCY H H H M H M H H H H H H
PKB CONSISTENCY H H L L H L H H H H H H
CKB CONSISTENCY H H H M L H H H H H H H
AFTER 00Z THURSDAY...
IFR conditions are possible Wednesday night with valley fog,
particularly in/near the mountains. Localized IFR conditions
are possible with showers and storms at times on Thursday and
Friday.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...None.
OH...None.
KY...None.
VA...None.
&&
$$
SYNOPSIS...MEK/GW/JMC
NEAR TERM...MEK/RPY/GW
SHORT TERM...JMC
LONG TERM...JMC
AVIATION...GW
Area Forecast Discussion
National Weather Service Springfield MO
716 PM CDT Tue Apr 29 2025
.KEY MESSAGES...
- Slight Risk (2 out of 5) for additional strong to severe
thunderstorms this later this evening into the overnight
hours. Primary hazards are damaging wind gusts up to 70 mph
and large hail, but brief tornadoes cannot be ruled out.
- Flood Watch in effect from 7 AM Today through 7 AM Thursday
with a Slight (2 of 4) to locally Moderate (3 of 4) Risk for
excessive rainfall. Multiple rounds of showers and
thunderstorms will result in additional widespread amounts of
0.5 to 3 inches, with localized amounts up to 3 to 5 inches,
especially along the southern Missouri border.
- Shower and thunderstorm chances continue during the day
Thursday. Therefore, any lingering flood impacts may continue
for areas receiving more heavy rainfall.
- Warming trend and relatively drier weather expected this
weekend into early next week.
&&
.SHORT TERM /THROUGH THURSDAY/...
Issued at 300 PM CDT Tue Apr 29 2025
Current mesoanalysis places an extensive cold pool across our
area in the wake of a strong thunderstorm complex that moved
through the area this morning. Cloud debris and lingering
showers through the day should keep high temperatures cooler in
the middle 60s and lower 70s. An outflow boundary is noted
across northern AR with the surface cold front stretched across
MO, parallel to, but just north of I-44. Recent observations
show southeasterly winds returning along the I-44 corridor, but
the cold front continues to sag south. The big question for
additional severe weather tonight will be dependent on if the
cold front moves further south with help from this morning`s
cold pool, or if an analyzed inverted trough inching in behind
the outflow boundary allows southerly winds to re-destabilize
the atmosphere ahead of the next system tonight.
Slight Risk for additional severe thunderstorms tonight:
Current RAP analysis shows no mixed-layer instability for our
area in the wake of the convective system. However, surface
observations and our current VWP show southeasterly winds and a
veering profile aloft within an inverted trough trying to sneak
into the area. On the flipside, as mentioned above, the cold
front is still sagging south and may accelerate a bit within the
rain-cooled air. RAP trends have not been handling this cold
pool well, trying to bring instability back into the area too
early. Therefore, there is still uncertainty in how far north
instability returns before our next widespread round of showers
and thunderstorms come in.
Current thoughts are that there is high confidence in
thunderstorms developing over the Red River Valley, growing
upscale, and lifting northeast into the Ozarks tonight.
Therefore, there is high confidence in widespread showers and
thunderstorms later tonight. Timing of this system into our
western CWA could be as early as 6-8 PM, more likely between 10
PM - 1 AM, or as late as after 2 AM. The amount of instability
will determine the severe risk, as deep layer shear will be
sufficient for organized severe. The RAP seems to be most
bullish, setting up the MLCAPE gradient along the the I-44
corridor. This is where the Slight Risk contour is as well.
Therefore, if we see this sufficient destabilization, wind gusts
up to 70 mph and perhaps a brief weak tornado or two will be
the main hazards along the line. If the instability remains
south of the border, the system will bring mainly stratiform
rain and some lightning. Trends will be monitored and relayed
via chat as we know them.
Chances for excessive rainfall and severe storms Wednesday:
After the system tonight, there will be another lull in activity
with cloud debris and lingering scattered showers across the
area. Then, the mid- and upper-level shortwave trough will
finally begin translating eastward into the area. This will
provoke a surface mass response, advecting mid-60 dewpoints and
1000-1500 J/kg MLCAPE (according to the HREF mean) ahead of the
progressing surface system. CAMs are in very good agreement with
this lift initiating another system of thunderstorms across the
Red River Valley and bringing it into southern Missouri
Wednesday afternoon into the evening. The instability will be
enough for potential severe weather. A Marginal (1 of 5) Risk is
currently in place for the whole CWA to account for this. Given
the MCS type system expected, damaging winds should be the main
hazard with a secondary brief tornado hazard. HRRR/RAP
soundings suggest 0-3 km bulk shear vectors at 15-25 kts to the
NE, especially in the eastern Ozarks. This suggests a low-end
tornado threat, that could potentially increase with any
modulation of surface winds to more southeasterly ahead of the
line. After this system exits Wednesday night, another lull will
follow with only lingering showers.
When all is said and done, additional rainfall amounts of 0.5
to 3 inches, with localized areas seeing 3 to 5 inches,
especially along and south of I-44, can be expected. Locally
heavier amounts will be determined by how much instability we
can get ahead of both systems. The line of thunderstorms this
morning produced some cells with 2-4 in/hr rain rates as PWATs
reached 1.4-1.6 inches. These PWATs are forecast to hover around
the area, so any thunderstorm could produce locally excessive
rainfall. Therefore, the Flood Watch remains in effect through 7
AM Thursday. However, the axis of heaviest rainfall is shifting
south, thanks to help from the outflow boundary from this
morning`s system. As such, northern counties may be dropped from
the Watch a bit early as we go into tonight.
With a static airmass in place, highs will stay in the lower 70s
Wednesday with lows in the upper 50s tonight and Wednesday
night.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
Issued at 300 PM CDT Tue Apr 29 2025
60-90% shower and thunderstorm chances continue Thursday:
The mid-level shortwave trough and associated surface cold front
should clear the area Thursday morning, and showers and thunderstorms
are expected to be ongoing along it across the eastern Ozarks
(60-90% chance). Despite the cold front clearing through the
area, lingering moisture behind the front and diurnal heating
should generate some modest instability behind the front. Deep
layer shear is expected to dwindle with western extent as the
trough shifts eastward. Therefore, scattered shower and
thunderstorms are expected across our forecast area, with a
Marginal (1 of 5) Risk for strong to severe storms across the
eastern Ozarks Thursday. Given dwindling deep layer shear into
the 20-35 kt range, multicells with 60 mph downbursts and
marginally severe hail up to quarters will be the main risk with
these more scattered storms.
Warming trend and drier weather for the weekend and next week:
After the system clears Thursday, highs are expected to hover
around the low 70s through Sunday, with lows in the middle to
upper 40s. Then, global ensembles depict pronounced ridging
strolling in from the west. This should enact a warming trend
with relatively drier weather. NBM spreads and means slowly
increase from Sunday into early next week with highs increasing
to the upper 70s Tuesday.
&&
.AVIATION /00Z TAFS THROUGH 00Z THURSDAY/...
Issued at 711 PM CDT Tue Apr 29 2025
Rounds of showers and thunderstorms will continue, off and on,
through the TAF period. Confidence in timing, probabilities, and
strength of thunderstorm clusters decreases with time. Expect
greater variation in conditions than what can be shown in the
TAFs.
&&
.SGF WATCHES/WARNINGS/ADVISORIES...
KS...Flood Watch through Thursday morning for KSZ073-097-101.
MO...Flood Watch through Thursday morning for MOZ055>058-066>071-
077>083-088>098-101>106.
&&
$$
SHORT TERM...Price
LONG TERM...Price
AVIATION...Titus