Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 05/14/20
Area Forecast Discussion...UPDATED
National Weather Service Brownsville TX
629 PM CDT Wed May 13 2020
.DISCUSSION...Updated for latest aviation discussion below.
&&
.AVIATION...VFR conditions are expected to prevail through the
evening, then MVFR ceilings are expected to develop after
midnight, then clear back to VFR tomorrow morning. Some models
bring isolated thunderstorms to the Rio Grande Valley after
midnight that could impact the airfields, but confidence is low in
the development of these storms, so have left any mention of
thunderstorms out of the TAF package at this time. As for winds,
gusty southeast winds are beginning to back off and will decrease
overnight before gusty conditions return mid morning tomorrow.
&&
.PREV DISCUSSION... /issued 249 PM CDT Wed May 13 2020/
SHORT TERM (Now through Thursday Night): A swift 500 mb short wave
trough will approach from the west tonight. A few thunderstorms may
drift off the Sierra Madre Orientals to the west of the CWA and move
toward the upper valley later this evening into tonight. Not all
models pick up on a signal across the CWA overnight, however, but
the ARW and HRRR are two that show some convection moving into the
area from the west later this evening and overnight. Tried to hold
the middle ground and indicate some activity from midnight through
dawn, followed by coastal shower activity during early daylight. Low
temperatures will be in the lower to middle 70s.
Any lingering showers and thunderstorms will end from west to east
Thursday morning as the mid level short wave continues to move east.
Thursday will be very warm with high temperatures in the 90s, except
for the 80s at the coast. A modest short wave ridge will move over-
head. Moderate southeast winds will prevail under partly cloudy
afternoon skies. Did not include a recurrence of convective chances
for Thursday night, though a few mountain rooted cells to the west
could again develop. Cloud cover will increase to mostly cloudy with
low temperatures in the 70s.
LONG TERM (Friday through Wednesday): By Friday afternoon the
500mb shortwave begins to ramp up as it moves toward East Texas.
The models have come into slightly better agreement of this path
through the weekend. PWAT values rise to near 2.0 to 2.1 inches
late Friday night into Saturday afternoon, with the bulk of the
best rainfall chances in Deep South Texas remaining across the
northern ranchlands. A slight lull in rainfall is possible late
Saturday into early Sunday as the shortwave spins across eastern
TX and western LA, with any spokes of mid level energy helping
convective development locally.
The models then still differ on where to take the 500mb low, with
the GFS now sliding it back SSW out over the western Gulf of
Mexico, while the ECMWF spins the energy further into the
Southeastern US, building mid level high pressure across Deep
South Texas. For now, have stuck with previous forecasts and
brought rain chances back into the CWA by Sunday afternoon,
continuing generally less than 30 percent on Monday and Tuesday,
with isolated convection, if any, on Wednesday.
Heavy rainfall remains a possibility, with confidence increasing,
especially across the northern ranchlands late Friday night into
Saturday afternoon. Confidence beyond that is low to moderate at
best. Temperatures remain near normal on Friday, dropping off due
to increased cloud cover and rain chances Saturday into Monday,
before warming again into next week.
MARINE (Now through Thursday Night): Surface high pressure
across the southeast United States interacting with lower pressure
across west Texas will support a tight pressure gradient across
the lower Texas coast. Moderate to breezy southeast winds and
moderate seas will prevail. Small craft should exercise caution to
low end small craft advisory conditions will be possible through
Thursday night.
Friday through Wednesday: High pressure strengthens across the
eastern Gulf of Mexico into this weekend, allowing winds to
diminish through most of the long term period. Coastal low
pressure may develop across the western Gulf by Monday and
continue into Wednesday, bringing variable winds across the
coastal waters. Elevated swell builds seas into the start of the
weekend, with Small Craft Advisories possibly needed Friday night
through Saturday. Overall marine conditions may improve into early
next week, with Small Craft Caution possible Sunday into Monday if
elevated swells continue.
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...None.
GM...None.
&&
$$
This product is also available on the web at:
HTTP://WEATHER.GOV/RGV
Aviation Update...69
Area Forecast Discussion
National Weather Service Dodge City KS
1017 PM CDT Wed May 13 2020
...Updated Synopsis...
.SYNOPSIS...
Issued at 1014 PM CDT Wed May 13 2020
Areas of fog are developing along and north of a frontal boundry
roughly from Johnson to Great Bend. Visibilities of 1/2 to 3/4
mile are reported in Garden City and Scott City with satellite
imagery showing areas of low clouds and fog from east of Syracuse
to Russell. A shortwave and surface low will move out of eastern
Colorado into western Kansas through the overnight keeping the
boundary around and southeast winds along the boundry. Fog
possibilities look good for much of the night in these areas.
&&
.SHORT TERM...(This evening through Thursday)
Issued at 333 PM CDT Wed May 13 2020
Interesting weather across southwest Kansas this afternoon. The
anticipated hot, dry downslope plume did indeed develop, which
reached a Johnson to Liberal line mid-afternoon. Temperatures were in
the 88 to 91F range across far southwest Kansas on a strong
southwest wind 20 to 30 mph, gusting over 40 mph at times. A very
small thermal circulation could be seen developing in the surface
observations as well as trends on radar and visible satellite. Low
stratus clouds were hanging tough northeast of the developing
thermal low, where temperatures were still stuck in the 50s.
The prospects of any thunderstorm activity late this afternoon and
evening are looking less and less across southwest Kansas, despite
strong boundary layer convergence along the dryline and especially
in proximity of the thermal low between Dodge City and Liberal. A
strong elevated mixed layer was in place, keeping a lid on
convective potential north of the Oklahoma border. It is still
possible that a convective plume could develop after 22Z or so, but
any such convective plume will be met with quite a bit of resistance
in the form of very high surface-based convective inhibition thanks
to lower temperatures immediately downwind of any initiation zone.
A subtle shortwave trough over Colorado and Wyoming will move out
over Nebraska tonight, and a weak front will push south into western
Kansas overnight. We anticipate a narrow corridor of light fog and
drizzle just north of the front tonight, affecting mainly the
northern counties, along/north of Highway 96. On Thursday, we will
be watching for another chance for thunderstorms along the front,
but the best forecast for placement of the front and attendant
strong/severe thunderstorm risk will be across mainly Barber County
in our forecast area. A better chance for our southwest and west
central Kansas region will be later on in the night, as post-frontal
upslope conditions improve with increased elevated CAPE and
warm/moist advection/convergence. A small mesoscale convective
system (MCS) or two will likely roll east-southeast across portions
of the west central/southwest KS region in the 06-15Z Friday time
frame.
.LONG TERM...(Thursday night through Wednesday)
Issued at 333 PM CDT Wed May 13 2020
As long as the weak polar frontal zone remains close by/just to our
south, we will continue to see fairly decent thunderstorm chances.
This will likely remain the case through Saturday Night until the
next strong front marks and end to this pattern. Another nocturnal
MCS or two is likely Friday Night/early Saturday which will likely
leave an outflow boundary somewhere across far southern KS or
northern OK. The last round of strong/severe storms would be
Saturday afternoon or evening before the next front moves in and
high surface pressure builds south. Sunday through at least the
first half of next week, we will be seeing a rather quiet period as
upper level high pressure expands across southern and central High
Plains. The next big Pacific storm system will approach the Rockies
mid-week, which will help break down the high to its east, but much
of the initial convective activity with this storm system will be
well north of western Kansas. Severe weather prospects for
western/central Kansas will probably increase by late next week
(starting perhaps by 22 May) as mid level heights continue to lower
and southwest flow aloft returns to the Central Plains.
&&
.AVIATION...(For the 00Z TAFS through 00Z Thursday evening)
Issued at 600 PM CDT Wed May 13 2020
Model soundings are in good agreement in a low level jet of around
50 knots between 03z and 09z Thursday in the Dodge City and Hays
areas. At the surface overnight the winds will be southeast at
around 15 knots. A surface boundary located west of Garden City
and Hays at 00z Thursday will slowly move south southeast early
Thursday morning and as this boundary passes Garden City and Hays
between 12z and 15z Thursday the southerly winds at 10 to 15
knots will shift to the north northwest. Along with the northerly
winds the latest HRRR Bufr soundings also indicated an increase in
low clouds. LIFR ceilings along with areas of fog will be
possible between 10z and 15z Thursday at Garden City and Hays. Low
VFR ceilings can be expected at Dodge City and Liberal between
10z and 15z Thursday.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 56 79 55 74 / 0 0 40 30
GCK 52 81 53 73 / 0 0 40 20
EHA 54 85 54 76 / 0 20 20 10
LBL 54 85 55 76 / 0 0 40 10
HYS 54 77 53 73 / 0 0 30 50
P28 59 82 60 77 / 20 10 50 40
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...Tatro
SHORT TERM...Umscheid
LONG TERM...Umscheid
AVIATION...Burgert
Area Forecast Discussion...UPDATED
National Weather Service Austin/San Antonio TX
1027 PM CDT Wed May 13 2020
.UPDATE...
The Severe Thunderstorm Watch for Val Verde County issued early
through 10 PM this evening was allowed to expire. There is strong to
severe thunderstorm moving across north central Val Verde County as
of this writing and we issued a Severe Thunderstorm Warning for it
through 11 PM. The storm is entering to an area where conditions are
less favorable to keep current status. Therefore, we think the storm
should begin to weaken within the next several volume scans.
Also with this update, removed the slight chances for showers and
thunderstorms over parts of south central Texas and kept showers
mentioned over two-thirds of the area in case some light shower
activity develops overnight as an upper level short wave moves over
the area. Still showing isolated thunderstorms over parts of the
western part of the Hill Country overnight where the better lift may
be present.
&&
.PREV DISCUSSION... /ISSUED 648 PM CDT Wed May 13 2020/
AVIATION...
VFR conditions are expected across the I-35 corridor through about
midnight tonight. A cluster of strong storms could be impacting KDRT
around 01Z through 04Z as these storms move out of northeast Mexico
and enter the western portion of Val Verde County. There is a split
decision between HiRes solutions bringing the storms over KDRT.
Since the HRRR is performing well with the ongoing convection, we
will follow its projected path of these storms with storms
affecting KDRT around 01Z-04Z (as already mentioned above).
Cigs/vsbys could lower a category or two depending on the intensity
over the storm if it does go over the terminal. Storms are likely to
dissipate around midnight tonight. Otherwise, MVFR cigs are
anticipated to begin around 05Z/06Z for the I-35 sites through
17Z/18Z Thursday. Can`t rule out an hour or two with IFR before dawn.
MVFR cigs are expected after 05Z for KDRT and last through 18Z.
Winds are forecast to be out of the southeast and south 7 to 10 knots
with gusts up to 17 knots.
PREV DISCUSSION... /ISSUED 332 PM CDT Wed May 13 2020/
UPDATE...
Updated to add Severe Thunderstorm Watch 180 for Val Verde county
until 10 PM CDT.
PREV DISCUSSION... /ISSUED 228 PM CDT Wed May 13 2020/
SHORT TERM (Tonight through Thursday Night)...
Low stratus deck has struggled to scatter and lift this morning. SSE
wind have begun to pick up this afternoon which will encourage
boundary layer mixing and promote additional clearing. Scattered
streamer showers are depicted by several high res models over the
coastal plains and areas east of I-35 for this afternoon. Low-end
POPs in for this activity till 21Z.
Attention will then turn to west TX and the Big Bend region where
storms are expected to initiate along the dryline. Convective
initiation should be around 21Z when a shortwave makes it`s way over
the state. Convective allowing models diverge on how this evening
activity is handled. General consensus is that shortly after sunset,
storms begin a downward trend and reach our far western counties as
they dissipate. Some outliers, like the ARW, carry this line of
potentially strong to severe storms a bit further into the interior
Hill Country and our central counties. One outlier, the 06Z and 12Z
3km NAM dissipates storms over the Rio Grande but carries a line of
storms into the northeastern Hill Country and over the Austin metro
all the way from northwest TX that developed along the dryline in
the late afternoon. Again this is an outlier but run to run
consistency has gained some attention. There will be a pretty strong
cap in place over our eastern counties this evening and overnight so
there is confidence that if any storms do make it as far as the I-35
corridor, it would be fairly weak. SPC does have our western 1/3
under a slight risk and a marginal risk stretching to the I-35
corridor. Main threats being large hail and damaging winds.
Overnight Wednesday, temperatures will remain warm, only dropping to
the low 70s for much of the region. Dewpoints will remain elevated
in the upper 60s to low 70s, so a warm and muggy night is in store.
Some fog development could take place for the interior Hill Country
with the absence of any rainfall but would remain confined to rural
areas of the Hill Country.
On Thursday, shower activity should be confined mostly along the
coast and over the Gulf as this latest disturbance continues
eastward. Kept low-end POPs in for our southeastern counties for
this. Slight warm up for Thursday with afternoon highs a couple of
degrees above what they were Wednesday and a brief break from rain
chances Thursday night.
LONG TERM (Friday through Wednesday)...
Models continue to be consistent with an upper level trough moving
across Texas for the end of the week. This will be a trigger for
showers and thunderstorms starting Friday and continuing through
Sunday. In the low levels warm, moist flow from the Gulf will prime
the atmosphere for a potential heavy rain event. PW values will
increase to 1.5 to 2.0 inches which is sufficient for heavy rain at
this time of year. At this time, the best chance for heavy rain looks
to be across the eastern half of our CWA. Rainfall totals from Friday
through Sunday morning will be generally two to four inches with
isolated amounts to six inches possible. Exact locations are hard to
determine at this time. This amount of rain will likely lead to
localized flooding and our confidence is growing that a Flash Flood
Watch will be needed for this time period. The upper system will move
slowly away from the region during the first part of next week and
low chances for showers will linger over the area Monday through
Wednesday.
&&
.PRELIMINARY POINT TEMPS/POPS...
Austin Camp Mabry 71 86 71 86 68 / 10 20 - 50 60
Austin Bergstrom Intl Airport 71 86 70 86 67 / 10 20 - 50 60
New Braunfels Muni Airport 71 87 70 86 68 / 20 20 - 40 60
Burnet Muni Airport 70 85 69 84 66 / 20 10 0 40 60
Del Rio Intl Airport 71 93 74 90 68 / 30 0 - 40 70
Georgetown Muni Airport 70 86 70 86 67 / 10 10 - 40 60
Hondo Muni Airport 71 90 71 90 67 / 20 10 0 40 70
San Marcos Muni Airport 71 86 70 86 67 / 20 20 - 40 60
La Grange - Fayette Regional 72 86 72 86 69 / 20 30 10 40 50
San Antonio Intl Airport 71 88 72 87 69 / 20 20 0 50 70
Stinson Muni Airport 72 89 73 88 70 / 20 20 0 50 70
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
Short-Term/Aviation...17
Long-Term...04
AREA FORECAST DISCUSSION
National Weather Service Sioux Falls SD
1039 PM CDT Wed May 13 2020
.SHORT TERM...(This Evening through Thursday)
Issued at 247 PM CDT Wed May 13 2020
Spotty shower chances and abundant low level moisture headline the
main challenges with the near term today. Have seen high-based
showers and an occasional lightning string become more numerous
across our southern counties, though thus far not much more than
trace amounts being reported by automated stations. These showers
have produced wind gusts in excess of 40 mph at times, with isolated
stronger gusts near 50 mph around KSXK (Maurice/Orange City area)
in the late morning.
Any marginal instability beneath the elevated mixed layer diminishes
through the afternoon, so thunder risk and overall coverage of the
high-based showers expected to wane. However, subtle warm advection
atop a deepening moist layer could lead to some drizzle during the
very late afternoon/evening, so will continue to carry pops into the
evening, mainly east of I-29. This will be followed by areas of fog
development late evening/overnight as the low level moisture is
compressed further toward the surface beneath a lowering warm nose
aloft. Will have to watch for areas of dense fog, but this currently
appears more likely confined to higher elevations of southwest MN,
Opted to not issue any headlines at this time, but next shift will
want to monitor trends. Combination of moisture/clouds will keep
temperatures rather mild tonight, with lows in the upper 40s-lower
50s expected in most areas.
Forecast soundings show the low level moisture becomes quite shallow
by shortly after daybreak, so should not take too long to burn off
any lingering fog, though scattered-broken stratocu likely to
persist through at least mid-late morning. HRRR and other hi-res
models showing a few light showers sliding across our southern areas
again around daybreak, with additional light showers possible by mid
to late afternoon along a subtle wave sliding southeast through the
region. GFS/Canadian/RAP a bit more burly with the instability near
and south of this wave, so will include a thunder mention with the
low pops for shower development along the weak boundary. Instability
profiles are rather narrow, and convergence along the boundary also
on the weak side, so not anticipating more than garden-variety
showers/isolated storms at this point. Highs tomorrow should be
quite a bit warmer than the past couple of days, though any late day
showers may result in isolated cooler pockets. Overall though, will
trend back toward the warmer side of guidance with highs in the
lower to mid 70s.
.LONG TERM...(Thursday Night through Wednesday)
Issued at 247 PM CDT Wed May 13 2020
Any late day showers tomorrow afternoon expected to diminish quickly
with loss of heating before sunset, leaving a brief stretch of quiet
weather Thursday night into Friday for most of the CWA. Blended pops
a bit too aggressive spreading precip chances eastward with ridging
surface and aloft across the forecast area into Friday evening, so
have cut back progression to keep chances primarily west of the
James Valley through sunset, then gradually expanding eastward
Friday night.
Saturday continues to look like the wettest day of the mid-long
range forecast period as broad trough slides through the northern
Plains. With the approaching trough and 60-80kt jet rounding the
base of the trough, deep shear reaches 40+kt, which would be
supportive of organized convection...if there was much risk of
convection in the first place. That said, instability remains quite
meager throughout the day, with pockets of sub-1000J/kg MUCAPE
indicated by the models near the surface boundary, while away from
the boundary remains much more stable. Will continue with a chance
of storms, but at this time the potential for severe storms looks
low given the lack of instability. That said, still looking at a
potential for some moderate rainfall, mainly in our western counties
where amounts could top a half inch in some areas. Lesser amounts
toward northwest Iowa, though pockets of heavier rain possible with
any convection.
With the more abundant rain/clouds on Saturday, that should also be
the cooler day of the mid range, with highs in the lower-mid 60s
more prevalent, while Friday and Sunday more likely to see readings
climb into the lower 70s in several locations.
Longer range from Monday onward, we work into a much warmer pattern
which maxes out midweek next week as highly amplified upper ridge
moves into the central CONUS. Low-mid level temperatures in the 90th
percentile or higher in terms of climatology work into most of the
region by Tuesday and Wednesday, accompanied by more humid air as
dew points push into the 50s, as well as increasing southerly winds.
Blended guidance gives highs in the 80s both days, which is near the
median of available individual guidance. Still room for adjustment,
but all in all looks like a taste of early summer toward the end of
this forecast period.
&&
.AVIATION...(For the 06Z TAFS through 06Z Thursday night)
Issued at 1038 PM CDT Wed May 13 2020
A messy overnight period is in store for the area. Currently there
are IFR/LIFR ceilings across NW IA into SW MN, turning to VFR
conditions west of the James River Valley. Ceilings will be dropping
from east to west, as winds continue to decrease allowing the
stratus deck to lower. Fog is expected to develop as well, with the
best chances for fog remaining in NW IA and SW MN, with possible
expansion westward.
After sunrise, mixing out of the fog/stratus deck will likely take a
couple hours due to the light variable winds. Winds will eventually
settle in a west-northwest direction by afternoon, with isolated
chances for showers and a couple rumbles of thunder.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...JH
LONG TERM...JH
AVIATION...APT
Area Forecast Discussion
National Weather Service Wichita KS
637 PM CDT Wed May 13 2020
.SYNOPSIS...
Issued at 426 PM CDT Wed May 13 2020
A trough is positioned on the eastern Rockies and moving eastward
tonight while another wave is set over the Great Basin. The dry line
for the eastern system is still along the Kansas/Colorado border
into the Panhandles. There is a warm front which has made little
northern progress given the ongoing drizzle in south central and
convection in southeast Kansas. Persistent precipitation in south
central and southeast Kansas has lasted through the day thus minimal
breaks in the cloud cover. Warm air advection has allowed for a
boost in temperatures comparatively to the past couple of days as
values are roughly 10 degrees higher.
&&
.SHORT TERM...(This evening through Saturday night)
Issued at 426 PM CDT Wed May 13 2020
Highlights:
1) Thunderstorm potential tonight near but mainly north of the I-70
corridor
2) Strong and severe thunderstorms southeast of KS Turnpike on
Thursday
3) Thunderstorm and flooding potential Friday and Saturday
4) Warmer
Challenges:
1) Precipitation chances tonight
2) Rainfall amounts and respective flooding issues
3) Convection for Thursday to Saturday
Changes: Slight adjustments to precipitation chances
As highlighted the past few days, this period remains active with
multiple rounds of showers and thunderstorms. There could be strong
to severe thunderstorms with large hail and damaging winds. A rainy
week and any additional rainfall will certainly lead to flooding
concerns in the coming days especially across southeast Kansas where
the amounts are expected to be the greatest.
Tonight - The low pressure system and respective boundaries will
slowly move east tonight. It still appears that the dry line should
stay off to the west. Moisture transport directly into Oklahoma and
the eastern half of Kansas has persisted through the day and should
through tonight. Low clouds and drizzle are certainly a limiting
factor in the convective potential in south central Kansas keeping
the cap in place. It is possible that there may be some breaks later
on, but this probably won`t be enough to destabilize the environment
for what is needed. While this is said, any storms that develop in
southwest Kansas and track eastward could move into south central
Kansas. Thus the possibility exists for Harper/Kingman/Sumner
counties, but it would likely be limited and diminish in intensity
quickly after arrival.
Attention next turns to central Kansas as the frontal boundary
pushes northward and the subsequent wave moves east. An increase in
moisture transport, instability and frontogenesis is anticipated in
that area tonight. There is potential for strong to severe storms
north of the I-70 corridor after 9PM tonight. The Storm Prediction
Center has adjusted their slight risk for that area and pushed it
even further north limiting it to along the central and eastern
Kansas/Nebraska border. Reflectively models are showing that trend
as well keeping convection closer to the border.
Thursday - A persistent trend exists that the focus will be east
of the Kansas Turnpike with models showing 0-3km MUCAPE of 3-4.5k
J/kg and about 20-30kts of 0-6km bulk shear. The RAP has a bit
more shear which is closer to 40kts. Strong to severe
thunderstorms remain possible in the afternoon and early evening
hours that may start as supercells then could modify depending on
cold pools. The threats are large hail near golf ball size and
potentially 60 mph winds. There is some uncertainty as highlighted
in the previous discussion; however, the parameters can`t
underplay the severe weather potential.
Friday and Saturday - Another wave is anticipated to move through on
Friday, but there is less instability. Oklahoma is more likely to
see strong to severe storms. The threat exists in Kansas; however,
the outlook is better on Saturday when a trough moves across. Strong
to severe thunderstorms will once again be possible. The potential
may be in south central and southeast portions of the state, but it
still a bit early to highlight any specific area. Stay tuned for
more information.
.LONG TERM...(Sunday through Wednesday)
Issued at 426 PM CDT Wed May 13 2020
Highlights: Quieter and warmer
A ridge should move in on Sunday then stay put through next
Wednesday. This will certainly be a welcome change following the
rainy week, and the ground should be able to dry up a bit.
Temperatures are forecast to be in the upper 70s to lower 80s which
will be another nice change from the cooler first half of this week.
Outdoor activities should flourish. Enjoy!
&&
.AVIATION...(For the 00Z TAFS through 00Z Thursday evening)
Issued at 631 PM CDT Wed May 13 2020
A strong frontal system continues to slowly move over the region
this evening and overnight. IFR to LIFR conditions are expected
over much of the region for the first part of the TAF period with
most areas expected to see the low clouds and drizzle. There is a
slight chance for some thunderstorm activity before 05Z tonight
for HUT and ICT but the chance appears to be very low and have
kept it out of the TAF for now. The other main concern for tonight
will be some LLWS which is expected to develop as the night
progress. This is expected to affect all terminals tonight and is
expected to abate a few hours after sunrise tomorrow.
By morning, the LIFR conditions are expected to lift and give way
to MVFR conditions or VFR conditions depending on how progressive
the next short wave is. This will also create some thunderstorm
issues tomorrow afternoon but models right now do not agree on
timing or intensity.
Metzger
&&
.HYDROLOGY...
Issued at 426 PM CDT Wed May 13 2020
This has certainly been a wet period with three day rainfall
totals from 2 to 3 inches across south central and southeast
Kansas which doesn`t include the precipitation that fell since 7AM
today. One report in Butler County was an additional 3 inches.
Thus some locations have received around 4 to 5 inches or more in
the past few days. There was some minor flooding with the
thunderstorms today, but this has since receded as the
precipitation moved out.
The concern transitions to the next few days when additional
rounds of thunderstorms are anticipated. A saturated surface
especially for portions of south central and southeast Kansas will
have a hard time absorbing a significant amount of additional
rainfall which can undoubtedly occur with thunderstorms. Thus this
will be certainly be something to be monitored. Rises on creeks
and rivers are anticipated. The questionable factor is the amount
of precipitation that will fall which is tough to gauge with
convection. Therefore it is hard to place a degree of impact. Stay
tuned.
&&
.PRELIMINARY POINT TEMPS/POPS...
Wichita-KICT 64 82 63 78 / 20 20 60 50
Hutchinson 61 80 60 76 / 20 10 60 50
Newton 62 79 61 75 / 20 20 60 60
ElDorado 63 80 62 77 / 20 30 70 60
Winfield-KWLD 64 82 65 81 / 20 30 70 50
Russell 55 79 55 74 / 30 10 50 50
Great Bend 57 79 56 75 / 20 0 50 40
Salina 60 79 58 75 / 40 10 60 70
McPherson 60 79 58 75 / 20 10 60 60
Coffeyville 65 80 66 79 / 20 40 70 50
Chanute 65 79 64 78 / 20 60 80 60
Iola 64 79 63 77 / 20 60 80 70
Parsons-KPPF 65 79 65 78 / 20 50 80 60
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SYNOPSIS...VJP
SHORT TERM...VJP
LONG TERM...VJP
AVIATION...ELM
HYDROLOGY...VJP
Area Forecast Discussion
National Weather Service North Platte NE
632 PM CDT Wed May 13 2020
.SHORT TERM...(This evening through Thursday night)
Issued at 315 PM CDT Wed May 13 2020
Rain chances tonight hinge on increasing mid level moisture,
increasing 500mb winds and cooling aloft associated with a weak
upper level disturbance near Salt Lake City this afternoon. A few
storms are firing on the Laramie Range this afternoon and these
storms will venture into wrn Nebraska this evening.
A second area of thunderstorms may form across swrn Nebraska later
tonight. Given that the rapid refresh models show these storms
developing across scntl Nebraska, confidence is on the low side.
Nonetheless, increasing moisture fueled by a 30kt low level jet
tonight and cooling aloft from the disturbance near Salt Lake might
set off a few thunderstorms.
All of this weather should clear out of wrn and ncntl Nebraska
Thursday with clearing skies to follow. Another disturbance is
expected to move across the Colorado Rockies Thursday evening
affecting wrn and ncntl Nebraska with showers and thunderstorms
late Thursday night or early Friday morning.
The POP forecast leans on the HREF and short term model blend which
is a slower forecast and similar in timing to the SREF and HREF. The
temperature forecast uses the short term model blend plus bias
correction. This temperature forecast is slightly warmer at night
and cooler during the day than the guidance blend. Wrn and ncntl
Nebraska will be post frontal Thursday with the passage of a weak
Pacific cold front tonight.
The severe weather forecast tonight and Thursday night is marginal.
The risk of sfc based storms is generally low given that the storms
across the region will probably form post frontal. The HRRR and NAM
sfc wind gust products indicate gust potential to 50 mph across wrn
Nebraska for a few hours this evening. Cold air aloft (-13C to -15C)
and strong winds near 45kt at h500mb would seem to support small or
marginal 1 inch hail but the RAP model shows very modest elevated
CAPE, less than 1000 J/KG. This might mean the winds are too strong
aloft relative to the available instability for severe storm
development.
.LONG TERM...(Friday through Wednesday)
Issued at 315 PM CDT Wed May 13 2020
There is little change in the extended forecast philosophy except
to say the warm up next week is evolving slower than previously
forecast. An upper level low near the coast of the Pacific
Northwest this afternoon will migrate slowly east through the nrn
Plains Friday and Saturday setting off rounds of showers and
thunderstorms across wrn and ncntl Nebraska. The low will be
across the upper Midwest Sunday and a second deeper upper low will
begin to descend southward toward cntl CA. The models now show
the Midwest storm drawing small batch of Canadian high pressure
into Nebraska this weekend and this will keep Sunday cooler than
previously forecast. The sfc high will move slowly east Sunday
night. Predicted highs Monday are now in the lower to mid 80s.
The West Coast trof will send a surge of warm air into the cntl
Rockies and the Central Plains Monday through Wednesday and sfc low
pressure will form near the WY-SD border. This supports the warmest
temperatures across wrn Nebraska and the rain forecast is dry Sunday
through Tuesday. By Wednesday, the long wave trof will have migrated
far enough east to lower heights across wrn Nebraska supporting
what would appear to be diurnal thunderstorm development.
&&
.AVIATION...(For the 00Z TAFS through 00Z Thursday evening)
Issued at 632 PM CDT Wed May 13 2020
VFR ceilings this evening, followed by an MVFR ceilings at KLBF
from 08z until 13Z. Lowest ceilings near OVC010. VFR conditions
expected at KVTN through the next 24 hours. A weak cold front will
move into western Nebraska after 06Z, with winds near 32010G15KT
on Thursday. Current isolated showers and storms in the panhandle
continue to weaken, with no showers expected at KLBF and KVTN
tonight and Thursday.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SHORT TERM...CDC
LONG TERM...CDC
AVIATION...Roberg
Area Forecast Discussion
National Weather Service San Francisco Bay Area
824 PM PDT Wed May 13 2020
.SYNOPSIS...Isolated to scattered rain showers will be possible at
times through early Thursday, especially over the North Bay and
across the Santa Cruz Mountains. Temperatures across the interior
will remain below normal through Thursday, while coastal areas will
be near normal. Drier conditions and slightly warmer temperatures
are forecast from Friday through at least midday Saturday before
cooler, unsettled weather returns late in the upcoming weekend.
&&
.DISCUSSION...as of 08:11 PM PDT Wednesday...KMUX radar has
remained rather active since this afternoon detecting isolated to
scattered showers around the Bay Area and Central Coast. Rainfall
for the most part has been rather light with a few bursts of
heavier showers. Given the scattered nature of the shower
activity amounts vary across the region, but the highest amounts
are in the North Bay and coastal mountains with up to 0.36" the
last few hours. No real bucket tip here at the office, but enough
drizzle has fallen to wet the ground. Given the rain and cloud
conditions today it should be that surprising that temperatures
were on the coldside. Highs were coldest across the North Bay and
in the 50s and 60s, but warmer to the south as areas saw a brief
shot of sunshine with highs in the 60s and 70s. Regardless, highs
were several degrees below normal for mid-May.
A few more showers will linger the next few hours, but mainly
south of San Francisco Bay. Latest HRRR and early look at the 00Z
NAM continue to show a break in the precip overnight. The break is
short-lived as additional rain showers return to the region on
Thursday. Rainfall is most likely once again across the North Bay
and points north. However, some tail end showers may make it to
the South Bay.
Active pattern will continue into the weekend as a stronger/wetter
system moves through the region.
&&
.PREV DISCUSSION...as of 2:24 PM PDT Wednesday...
The progressive upper level pattern will allow for some ridging
aloft on Friday and parts of Saturday. Surface temperatures will
respond accordingly and warm by around 2 to 8 degrees from
Thursday to Friday, with the most significant magnitude of warming
occurring in the North Bay. This will put afternoon highs within
a few degrees of their middle May climatological normals.
The ridge axis will push inland into the continent on Saturday as
a rather anomalous late season upper level low slowly approaches
the West Coast. Rain chances will begin to increase from north to
south as early as Sunday morning with lingering rain showers
persisting into Monday and Tuesday. Plenty of cold air aloft could
allow for some thunder; the NBM is already catching onto this
idea, particularly in the North Bay. The upper low begins to fill
as it pushes inland on Tuesday and Wednesday, leaving behind it
northwest flow and some ridging aloft.
&&
.AVIATION...as of 5:08 PM PDT Wednesday...For 00z tafs. VFR to
MVFR with light rain or drizzle at many locations, precipitation
moving southward to the Central Coast. Wet weather returning
Thursday mainly to the Bay Area, though still could see a few
sprinkles or light showers reaching the north Central Coast.
Mainly south to southwest winds tonight, west to northwest winds
Thursday.
Vicinity of KSFO...MVFR, southwest wind to 15 knots, decreasing to
5 to 10 knots tonight. MVFR to VFR Thursday.
Bridge Approach...Similar to KSFO.
Monterey Bay Terminals...VFR to MVFR tonight and Thursday morning.
A few showers arriving tonight. VFR Thursday, an isolated sprinkle
or light shower possible.
&&
.MARINE...as of 4:55 PM PDT Wednesday...Light southerly winds may
briefly turn westerly overnight. However, early Thursday another
weak front will pass to our north with winds turning southerly
once again before stronger west to northwest winds return Friday.
Winds turn southeast again later Saturday as a strong late season
cold front approaches with rain Sunday followed by a return of
northwest winds into early next week.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.Tngt...SCA...Pt Pinos to Pt Piedras Blancas 0-10 nm from 3 AM
&&
$$
PUBLIC FORECAST: MM/Rowe
AVIATION: Canepa
MARINE: RWW
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Area Forecast Discussion
National Weather Service Sacramento CA
305 PM PDT Wed May 13 2020
.SYNOPSIS...
Precipitation chances and cooler temperatures continue through
Thursday. Warmer and drier weather briefly returns Friday, followed
by wet and cooler weather for the weekend through the middle of next
week.
&&
.DISCUSSION...
Quasi-stationary upper level low off the Pac NW coast continuing to
spread light precip into interior Norcal, mainly in the mtns north
of I-80. Short-wave energy forecast to move into Norcal this evening
when some deeper convection is forecast over the Nrn Sac Vly, Shasta
Co mtns by the HREF, HRRR, but not nearly as much as the NAM3km, as
the HRRR generally allows for more convection. Given the current
cool, cloudier weather there, one could make an argument to follow
the NAM3km, as well as the lack of instability in the forecast
soundings. However, not ready to give up on the convective potential
yet, and to avoid "getting behind the 8-ball" we have drawn an area
of possible thunder in the above area during the 4-8 pm PDT period,
and in the topographically favored area given the enhanced
convergent/upslope Sly flow. The NAM3km simulated IR Satellite also
indicates an area of rapidly cooling cloud tops over this area
around 01z (6 pm). Showers are possible into Thu as the upper trof
axis follows this evening`s energy early Thu.
Upper level ridging shifts the upper low Nwd late Thu/Fri returning
dry and milder conditions to Norcal. Valley highs in the mid 60s
North to upper 70s South are expected Thu afternoon, with low 80s on
Friday which is near normal for this time of year.
There will only be a brief break in the dry/mild pattern as a large,
cold closed low from the Gulf of Alaska approaches on Sat. Wet
weather is expected to move in from the west in the afternoon,
becoming widespread over the area Sat night. (The initial frontal
band of the GFS is forecast to be much wetter than the ECMWF.) This
system looks more like an early spring system (some of the
parameters are suggesting a one in every 2-5 yr event), bringing
widespread precipitation, mountain snow, convection and strong winds
as it moves inland. JHM
&&
.EXTENDED DISCUSSION (Sunday THROUGH Wednesday)...
The broad, anomalous upper low mentioned in the short-term section
will continue to impact the region on Sunday and Monday. A fairly
sharp cold front is forecast to sweep through on Sunday morning
and afternoon spreading moderate rainfall, locally heavy in more
orographically enhanced areas. In locations which can catch a bit
more sunshine, enough instability may develop to spawn a few
thunderstorms but confidence in location and coverage are low at
this juncture. By Monday, the parent upper low nears the
northwestern California coast which will turn the activity into a
more showery nature. There should be a bit more instability as the
colder air aloft arrives from the northwest. The current GEFS
ensembles show a number of members with surface-based CAPE values
in the 200 to 400 J/kg range over the northern Sacramento Valley.
Global models show the upper low over central California by
Tuesday morning as the system continues to migrate southward.
This will encouarge additional shower activity on Tuesday,
particularly over the higher terrain. Regarding wintry
precipitation, snow levels are forecast to drop to 6,000-7,000
feet by Monday so mountain pass levels could start seeing
accumulations. Conditions to gradually improve by mid-week with a
ridge building in the wake. Temperatures initially around 5 to 15
degrees below climatology will eventually return to near average
by Wednesday. ~BRO
&&
.AVIATION...
While most locations can expect VFR conditions the next 24 hours,
local areas of MVFR and IFR are possible in developing showers,
mainly north of I-80. Local LIFR is possible over the mountains
obscuring terrain. Snow levels will increase to 6,500-7,500 feet
into this evening. South to southwesterly winds may gust to 20-25
knots over the Central Valley and Delta through 03Z. Winds will
slacken into the overnight hours.
&&
.STO WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
...Update to aviation forecast discussion...
.SHORT TERM...(This evening through Thursday)
Issued at 410 PM CDT Wed May 13 2020
As of 2030Z, water vapor imagery shows southwest flow over the
Central Plains with a broad trough in the western US. Embedded in
the southwesterly flow is a weak perturbation over northeastern CO
and southwestern NE. At the surface, low pressure has been deepening
in CO with the warm front still well to our south in northern OK.
The main change in the short-term is the break-up of the stratus in
eastern KS, which has not been handled well by the models. This is
likely due to mesoscale subsidence occurring behind this morning`s
showers and weak thunderstorms. With the WAA regime still in place
and the fact that soundings still show a saturated boundary layer
through the afternoon and evening, it`s tough to say when or if the
stratus will fill back in this evening in this area, but CAMs do
show showers developing ahead of the chance for storms tonight
mainly near the NE border.
Heading into tonight, the trend has been for storms to develop near
the NE border after 9pm and progress northward. There remains a bit
of uncertainty as to how far south in KS these storms develop, as
some model runs have kept them entirely in NE while others have them
initiating in north central KS near US-36. There was one run of the
HRRR late this morning that brought an isolated cell as far south as
Manhattan, but that appears to be an outlier at this point. In any
case, consensus generally keeps the convection near the 850mb
frontal boundary, which appears to be just north of the KS/NE border
by 06Z. It is also around this time that the LLJ strengthens to 40-
50 kts. With all these factors in mind, this could provide enough
lift in north central KS to overcome the cap. RAP and HRRR soundings
show MUCAPE as high as 2000-3000 J/kg at Concordia, although
effective shear ranges between 25-40 kts -- the RAP and HRRR go up
to 40 kts while the NAM has tended to stay within 35 kts. Large hail
would be the primary threat with any elevated storms that may
develop in this area tonight.
Thursday is when we have the better potential for severe weather in
the area, mainly in east central KS. By morning, the frontal
boundary should be situated from southwest to north central KS, and
there is generally good consensus to bring it near the Kansas
Turnpike by 21-00Z. Storms should initiate along this boundary
during this time frame and exit the area with it by 06Z. NAM and GFS
forecast soundings at Emporia show CAPE of 2000-3000 J/kg, although
bulk shear starts out around 25 kts in the afternoon before
increasing to 40 kts in the evening. With that in mind, there is
better potential for storms to develop with the eroding cap as well
as the instability, but the timing of the shear along with the
boundary placement may be the main piece to monitor to see how
organized updrafts will become. Locally heavy rainfall with any
storms will also be a concern.
.LONG TERM...(Thursday night through Wednesday)
Issued at 410 PM CDT Wed May 13 2020
Storms should be out of the CWA by 06Z Thursday. The boundary
lingers in southeast KS during the day Friday, with some models
trying to bring it slightly back north into east central KS while
others keep it south of the CWA. Saturday the boundary does move
further north with some variation as to how far north. Showers and
thunderstorms will once again return to the area with a more
amplified trough that moves into the area. Areas that see
repeated rainfall may have some flooding concerns if they receive
heavy rainfall on Thursday, but at this time the bulk of the rain
looks to fall on Thursday.
Next week, an amplified ridge returns dry weather to the area
ahead of a deep trough moving onto the Pacific coast. Temperatures
will be in the 70s to start the week, but increase well into the
80s by mid- week.
&&
.AVIATION...(For the 00Z TAFS through 00Z Thursday evening)
Issued at 639 PM CDT Wed May 13 2020
For the 00Z TAFS, CIGS are expected to lower toward the IFR
category after sunset. Thunderstorms could also develop around
midnight mainly north of I-70, so do have mention of precip during
the overnight period at sites to account for this possibility.
LLWS criteria may also be met at the TOP terminals for a few hours
tonight as a LLJ gets going. Dry conditions are expected for much
of tomorrow morning and into the afternoon as a cold front begins
to work across northeastern KS. Thunderstorms are expected to
develop along the boundary tomorrow afternoon near the TOP
terminals around 21Z.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Picha
LONG TERM...Picha
AVIATION...Teefey