Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 04/29/19
Area Forecast Discussion
National Weather Service Gaylord MI
1142 PM EDT Sun Apr 28 2019
.UPDATE...
Issued at 937 PM EDT Sun Apr 28 2019
High and mid clouds continue to filter in from the west, well
ahead of low pressure way out in the plains. Most of this is still
thin and sparse, and have reduced cloud cover in the early part of
the night. Still anticipate thicker cloud cover arriving from w
to e, though the bulk of that will occur around and after
midnight.
Very dry low level air in place; surface dew points mixed out
deep into single digits in some spots late this afternoon. This
will inhibit the ability of precip to push into northern MI.
Recent Rap/HRRR runs keep this forecast area dry until after
12z/8am, in line with the going forecast.
With a short period of decent radiational cooling this evening
until clouds thicken and the pressure gradient tightens, have
edged the min temp forecast a bit toward the low side of guidance.
Temps will start to climb again before daybreak, especially in nw
lower MI.
&&
.NEAR TERM...(Through Tonight)
Issued at 320 PM EDT Sun Apr 28 2019
...Mainly quiet through tonight...
High Impact Weather Potential: Minimal. Some light rain/snow
mix possible by early morning.
Pattern Synopsis/Forecast: Afternoon analysis reveals low
amplitude short-wave ridging building through the western Great
Lakes. Surface high pressure and dry air stretches from Canada
down through the Great Lakes. Fairly deep daytime mixing (near
750 MB per RAP soundings) has crashed surface dewpoints down
through the teens today producing RH values in the 15 to 25
percent range at many locations. Also, there is a little more
gustiness out there than anticipated owing to the deep mixing.
Meanwhile, lots of sunshine out there save for some heating of the
day CU across eastern upper and parts of northeast lower MI as
well as some high thin cloud cover also drifting through.
Upstream, slow move short-wave and surface low pressure is moving
into the Northern Plains. Warm advection forced band of cloud
cover and spotty precip have been steadily making their way into
the Midwest.
Mainly quiet conditions anticipated for the forecast area tonight
with steadily increasing high cloud cover from the upstream
system. Light winds/low dewpoints should allow temperatures to
fall back off through the 30s and possibly into the upper 20s,
although temperature drop will be moderated by the increasing
high clouds and eventually an increasing SE wind toward morning.
Meanwhile, latest guidance trends suggest the aformentioned warm
advection band of light precip will slide up into the region
during the overnight hours. But...forecast soundings suggest
otherwise, with lots of dry air hanging on below 8-10K feet until
at least Monday morning. Plan is to keep the forecast dry all the
way through the tonight period then begin to bring some light
rain/snow mixed precip into the region after 6 am.
&&
.SHORT TERM...(Monday through Wednesday)
Issued at 320 PM EDT Sun Apr 28 2019
...Unsettled and Cool...
High Impact Weather Potential...Low.
Primary Forecast Concerns...Precipitation type Monday.
Monday...A couple of weak disturbances centered to our north and
south move through the region Monday into Monday evening. Not a
whole lot of forcing in evidence and moisture looks like it`s barely
deep enough to make it up to -10 C. In addition, 850 mb temperatures
remain cool, generally on the order of -1 to -4 C. This all adds up
to lots of question marks as far as pops and precipitation type. At
this point will go with chance pops for much of the morning (as
model soundings/cross sections take a while to moisten up). Pops
should then increase to between likely and categorical from
southwest to northeast (highest pops across the south). Surface
temperatures will be above freezing so precipitation type will
depend upon the depth of the melting layer which looks marginal.
Could see a little snow, rain or a mix of the two. Little to no snow
accumulation is expected because of the time of the day and likely
lack of heavy precipitation, though can not rule out a little slushy
accumulation on grassy surfaces in some areas. Highs generally in
the upper 30s to lower 40s which should occur in the morning.
Monday night...Any remaining precipitation should diminish from
southwest to northeast leaving mainly cloudy skies. Temperatures not
falling a whole lot with lows in the lower and mid 30s.
Tuesday into Wednesday...A slow moving area of low pressure moves up
from our southwest likely bringing another round of wet weather to
northern Michigan Tuesday afternoon into Wednesday. Precipitation
should fall mainly as rain, though there could be a little snow
across eastern upper Tuesday night. Remaining unseasonably cool with
highs only ranging from the upper 40s to mid 50s. Lows Tuesday night
in the mid 30s to lower 40s.
.LONG TERM...(Wednesday night through Sunday)
Issued at 320 PM EDT Sun Apr 28 2019
...Remaining Cool...
High Impact Weather Potential: Very low.
The active and overall cool weather pattern is expected to continue
through at least next weekend. There will be chances for rain
showers Thursday and again Sunday. Friday and Saturday may turn out
rain free but wouldn`t totally count on that yet. Temperatures are
expected to remain at least a few degrees below average for early
May.
&&
.AVIATION...(For the 06Z TAFS through 06Z Monday night)
Issued at 1133 PM EDT Sun Apr 28 2019
VFR tonight. MVFR at times by Monday afternoon in rain or mixed
rain/snow.
High pressure is getting dislodged to the eat of the region. High
clouds are increasing ahead of our next system, still back in the
plains states. Low pressure will advance toward southern Lake MI
by Sunday afternoon. Clouds will continue to thicken tonight, and
precipitation will gradually push into the area Monday from sw to
ne. This will be mostly rain at the TAF sites, but could mix with
snow at times, especially at APN/PLN. Cigs will eventually lower
to MVFR, toward midday at MBL and in the afternoon at the other
sites.
Light winds tonight. E to se winds Monday, a bit gusty at times.
&&
.MARINE...
Issued at 320 PM EDT Sun Apr 28 2019
Another weather system will move through the Great Lakes region
Monday and Tuesday. Southeast winds will increase ahead of this
system and may bring some low end small craft advisory conditions
to parts of the northern Great Lakes for Monday into Monday night.
Winds/waves diminish for later Monday night into Tuesday.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...SMALL CRAFT ADVISORY from 9 AM to 5 PM EDT Monday for LMZ345-346.
LS...NONE.
&&
$$
UPDATE...JZ
NEAR TERM...BA
SHORT TERM...AS
LONG TERM...AS
AVIATION...JZ
MARINE...BA
Area Forecast Discussion
National Weather Service San Joaquin Valley - Hanford CA
100 PM PDT Sun Apr 28 2019
.SYNOPSIS...
Upper level low will bring slight chance of showers and
thunderstorms this afternoon and again tomorrow. Cooling trend
with the passage of this system will take the forecast area to
seasonable temperatures starting tomorrow through Wednesday, with
dry weather occuring at least through Friday.
&&
.DISCUSSION...
An upper level low centered near 30N and 125W is approaching the
California coastline this afternoon. This low will be responsible
for falling temperatures across the forecast area as well as a
chance for thunderstorms today and tomorrow across the Kern County
Mountains and the Sierra Nevada as it approaches land. For this
afternoon, the best chance of thunderstorms looks to be over the
Kern County Mtns. just west of the Grapevine area where CU has
been forming for the last hour or two. If a cell forms, it may
drift north over southern Kern County as indicated by the 18z HRRR
model. A thunderstorm or two is also conceivable over the Sierra
Nevada this afternoon Fresno County and southward.
As this system moves inland, some wrap around moisture will find
itself in our CWA, and will bring another chance of showers and
thunderstorms over the mountain crests. A storm or two could also
make its way into the Mojave Desert by tomorrow afternoon.
Rainfall totals from this system overall are not very impressive,
but it should be noted that any thunderstorm that forms could
produce runoff into already swift and high running rivers. As a
reminder, a Flood Watch is in effect for the Southern Sierra
Nevada, adjacent foothills, and Kern County Mountains from the
snowmelt that has been occuring over the last few days.
Tomorrow will also feature high temperatures around 80 degrees in
the lowest elevations of the SJ Valley, which is about average for
the forecast area this time of the year. Along with the passage
of this system will also be an uptick in wind gusts through the
Kern County Mountains and Deserts, but they look to remain below
advisory level at this time.
Tuesday, medium range models have a disturbance progged to arrive
into the forecast area from the north/northwest -- an "inside
slider". Currently, light precipitation is forecast to occur in
the Sierra Nevada with this system. However, this system will
again increase winds throughout Kern County by evening. Zonal flow
looks to dominate over the forecast area on Wednesday, and brief
ridging may occur on Thursday, bringing max T`s back up into the
upper 80s. Friday and onward has very low forecaster confidence as
there is a massive spread among the deterministic GFS and ECM.
EPS ensemble mean shows a Rex Block forming in the Eastern
Pacific, which is likely confusing model`s solutions for the next
ULL that may impact the forecast area later this weekend.
&&
.AVIATION...
VFR conditions will prevail at MCE, MER, FAT, VIS, and BFL through
at least the next 24 hours. MVFR or lower conditions are conceivable
at BFL after 12z. This possibility is not great enough to include in
the BFL terminal forecast at this time. Widely separated showers and
isolated thunderstorms are expected in Kern County and the Southern
Sierra Nevada this afternoon through Monday morning.
&&
.AIR QUALITY ISSUES...
None.
&&
.CERTAINTY...
The level of certainty for days 1 and 2 is medium.
The level of certainty for days 3 through 7 is low.
Certainty levels include low...medium...and high. Please visit
www.weather.gov/hnx/certainty.html for additional information
an/or to provide feedback.
&&
.HNX Watches/Warnings/Advisories...
Flood Watch through Monday morning CAZ190>196.
&&
$$
public...Bollenbacher
avn/fw...BS
synopsis...Bollenbacher
weather.gov/hanford
Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
1105 PM CDT Sun Apr 28 2019
.SHORT TERM...(This evening through Monday night)
Issued at 348 PM CDT Sun Apr 28 2019
Early this afternoon, the center of a strong storm system was
over north central Montana. Mid-high level cloudiness continued to
stream across the Upper Midwest, but low level moisture has
remained dry. This has kept any precipitation in the form of virga
or sprinkles this afternoon. This dry layer will also lead to a
slower onset of the precipitation overnight, with the bulk of the
precipitation across central/west central Minnesota before
midnight, which quickly moves across eastern Minnesota, and into
west central Wisconsin after midnight. It should also be a short
duration of the precipitation as most of the energy with this
system stays across northern Minnesota, west central Wisconsin
Monday morning. However, wrap around moisture associated with the
upper low, will bring some sprinkles or light showers across the
area by late morning/early afternoon. This is more diurnally
driven, anything that develops should quickly dissipate by the
late afternoon.
The next system will quickly wrap up over the four corners region
of the U.S. and move northeast across the Rockies, and into the
Plains by late Monday night, and early Tuesday. Some light
precipitation is possible toward sunrise Tuesday as this system
gets closer. Temperatures should be warm enough to keep the bulk
of the precipitation in the form of rain vs. snow. However, I
can`t rule out some light snow in west central Wisconsin, and
portions of central/east central Minnesota late tonight as
temperatures fall to around 35 degrees.
.LONG TERM...(Tuesday through Sunday)
Issued at 348 PM CDT Sun Apr 28 2019
The long term looks active and cool with several systems being
steered across the northern U.S. The first will be Tuesday and
Tuesday night with the surface low tracking across the Mid
Mississippi Valley. The heaviest rain will be located near the
quasi-stationary front along the low`s track, but a wave of light
rain should track northeast on the system`s northwest periphery
across the local area.
Beyond midweek or so, model consistency takes a dive with the
temporal and spatial details of each system, so the forecast is
littered with low chance PoPs. However, another wave is progged to
head through sometime around Wednesday night, Friday/Friday night,
and again Saturday/Saturday night.
With all the clouds and predominantly northerly flow through the
period, temperatures will remain 10-15 degrees below normal
through next weekend.
&&
.AVIATION...(For the 06Z TAFS through 06Z Monday night)
Issued at 1105 PM CDT Sun Apr 28 2019
Main change we`ve seen since the 00z TAFs is that hi-res models
are indicating there being two enhanced areas of precip. One from
western into central MN and the other southeast MN into central
WI. This means very little precip will likely be experienced in
between at RWF/MKT/MSP/RNH. As precip/virga has spread across the
area, we have seen cigs respond, though models are starting to
keep cigs primarily MVFR, so did raise heights some. Also still a
bit of an unknown is how skies will react as a mid-level dry slot
moves in behind the inverted surface trough. HRRR is pretty
aggressive with showing expansive clearing across the area by the
afternoon, though there is also the indication we could see some
dirunal showers develop within the steep lapse rates of the dry
slot. Was not quite that aggressive, but did move up return to
VFR in the afternoon with the 6z TAFs.
KMSP...MSP looks to shoot between the better forcing to the north
and moisture to the south. Even at 4z, the temp/dewp spread was
almost 30 degrees, so continued to push back precip arrival. With
the better moisture sliding off to our east, probability for
seeing IFR cigs is decreasing.
/OUTLOOK FOR KMSP/
Tue...MVFR. Aftn -RA likely. Winds E 10-15 kts.
Wed...MVFR. Winds NE 5-10kts.
Thu...MVFR bcmg VFR. Winds NW 10G20kts.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
&&
$$
SHORT TERM...JLT
LONG TERM...BORGHOFF
AVIATION...MPG
Area Forecast Discussion
National Weather Service Portland OR
855 PM PDT Sun Apr 28 2019
EVENING UPDATE: for aviation section.
.SYNOPSIS...North flow aloft will continue over the area through
midweek. Weak disturbances within the flow will bring a small threat
of late afternoon and evening showers to the South Washington
Cascades through Tuesday. Dry weather with seasonal temperatures then
continue through the end of the week.
&&
.SHORT TERM...Tonight through Wednesday...Water vapor imagery early
this afternoon showed a 500 mb ridge axis along 130W extending into
the Gulf of Alaska. Meanwhile, A closed low was located off the
Southern California coast and another low was drifting east across
the Upper Midwest. The end result for the Pacific Northwest is north
flow aloft with several short-wave features within the flow. Water
vapor showed one such short-wave exiting SE Oregon at 20Z. In the low
levels, north to northeast flow is resulting in a rather dry air
mass, with early afternoon dew points in the 20s to mid 30s across
most inland areas. Cascade locations had dew points in the teens.
Higher resolution models like the HRRR and NamNest indicate the
potential for isolated shower activity over the South Washington
Cascades through early evening. At 20Z GOES-17 imagery showed
stratocumulus/cumulus developing over around Mt. Adams. A surface
thermal trough will remain over the interior valleys to the coast
tonight. Minimal to no cloud cover and low dew points will lead to
another cool night, but not quite as cold as this morning. Expect
some frost areas, but mainly confined to the Cascade valleys. But,
cannot rule out localized near-freezing temperatures in the usual
cold inland valley areas, such as Banks, Forest Grove, Hillsboro and
around Eugene. Model soundings suggest a low-level inversion, which
will allow the Coast Range and Cascade lower slopes, as well as the
Willapa Hills, to see a few degrees of warming tonight.
The 500 mb north flow pattern continues through the short term with
additional short-waves within the flow. The NAM shows another such
impulse tonight, but due to the over-land trajectory not expecting
any precip. A stronger short-wave drops south Mon afternoon and
evening, for a better chance of showers over the South Washington
Cascades and a small threat over the North Oregon Coast Range. The
north-to-south surface gradients continue Mon afternoon for breezy
north wind through the Willamette Valley and along the coast. By 12Z
Tue the surface thermal trough will extend from the Willamette Valley
to the coast, but then shift east Tue afternoon. Despite the shift to
onshore low-level flow models do not show much in the way of low
clouds, even along the coast. The 975 mb NAM RH remains rather dry
12Z Wed. Thus, went a little lower than guidance on Wed min temps.
Model 850 mb temps show minimal cooling Wed compared to Tue. This
translates to a near persistence forecast, although the low-level
onshore flow should result in a little cooling to the coastal areas,
west slopes of the Coast Range and the SW Washington coastal
interior. Weishaar
.LONG TERM...Wednesday night through Sunday: A generally dry start
to the extended as the PacNW is situated under a NNW flow aloft from
a broad upper low centered over the Yukon Territories and extending
south over the central CONUS. Further west, there is a rex block
with the attendant upper low centered near 35N/145W. That far
western position will allow for a weak short-wave to drop southeast
along the flow Wednesday night and Thursday. Main impact will be
increased clouds and slightly cooler temperatures although most of
the medium range models show very light qpf across portions of the
CWA. Would be surprised at this point if anything measurable reaches
the ground. Have gone with sprinkles for now.
The rex block moves closer through the weekend with flow becoming
increasingly more zonal over the top of us. May also get some
periods of sprinkles/drizzle Friday and Saturday, but am even less
excited for those two days than the first round. For Sunday, models
and their respective ensembles are not quite sure on how to handle
the cut-off low portion of the rex pattern. GFS and the majority of
its ensemble members absorb the low into a deepening upper trough
crossing toward the PacNW from the northern stream. The ECMWF is
rather insistent on maintaining a cut off low off the southern
California coast. The former would bring a minimal chance of rain by
Sunday afternoon with better chances overnight into Monday, while
the latter sees some light QPF across the north earlier on Sunday.
Decided go give a 20% PoP to many areas, although Sunday could
largely end up having the same minimal rain threat as the prior
days. Main impact will again bee cooler temperatures with increased
cloud cover. /JBonk
&&
.AVIATION...Cool and dry air mass over the region tonight and Mon,
with dry northerly flow aloft. This will maintain mostly clear skies
again tonight through Monday.
KPDX AND APPROACHES...No adverse weather impacts expected, with
clear skies under high pres and light northerly flow. /Rockey
&&
.MARINE...High pressure over the northeast Pacific and a thermal
trough along the south Oregon coast are causing gusty northerly
winds to 30 kt this afternoon and evening. This pattern starts
to weaken as the thermal trough weakens tonight allowing winds to
decrease a little, but winds will continue to gust up to 20 to
25 kt overnight tonight into Monday. Monday this pattern finally
starts to really break down as the thermal trough weakens
significantly. This means winds should drop below 20 kt by
Tuesday morning, probably Monday night north of Cascade Head.
High pressure continues to dominate over the northeast Pacific
through all of next week, but once winds drop below 20 kt Monday
night or Tuesday, conditions stay relatively benign with winds
staying generally out of the north to northwest and staying
mostly below 20 kt through the end of next week.
Seas continue to stay steep this afternoon and evening, but will
start to subside Monday morning with the weakening winds. Once
seas drop to 5 to 6 feet on Monday, seas should stay around 4 to
6 feet through the end of next week. -McCoy
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...None.
WA...None.
PZ...Small Craft Advisory for winds from 4 PM this afternoon to 7 AM
PDT Monday for Waters from Cape Shoalwater WA to Cascade
Head OR from 10 to 60 NM.
Small Craft Advisory for hazardous seas until 4 AM PDT Monday
for Coastal Waters from Cape Shoalwater WA to Florence OR
out 60 NM.
Small Craft Advisory for winds until 4 AM PDT Tuesday for
Waters from Cascade Head to Florence OR from 10 to 60 NM.
Small Craft Advisory for winds from 4 PM this afternoon to
midnight PDT tonight for Coastal waters from Cape
Shoalwater WA to Cascade Head OR out 10 NM.
Small Craft Advisory for winds from noon today to 4 AM PDT
Monday for Coastal waters from Cascade Head to Florence OR
out 10 NM.
&&
$$
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This discussion is for Northwest Oregon and Southwest Washington
from the Cascade crest to 60 nautical miles offshore. This area is
commonly referred to as the forecast area.
Area Forecast Discussion
National Weather Service San Diego CA
826 PM PDT Sun Apr 28 2019
.SYNOPSIS...
Low pressure will move across Southern California late tonight
through Monday. Maintaining gusty westerly winds over the mountains
and deserts, and deepening the marine layer onto the coastal
mountain slopes. There is even a chance for isolated thunderstorms,
but most of the precipitation is expected to be light. Some drizzle
will be possible along and west of the mountains on Tuesday as well,
due to the very deep marine layer that will be in place. Dry, with
modest warming Wednesday through Friday.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
At 8 PM PDT...Radar indicated showers and isolated thunderstorms
tracking NNE over the inner coastal waters. Most of this activity
was weak and moving rapidly. A more solid line of thunderstorms was
farther south off the Baja CA Coast. This was also lifting NNE and
may track into the SGX forecast area later this evening. Elsewhere,
skies were partly cloudy with wave clouds over the mountains. The
00Z Miramar sounding was still quite stable with a 7C inversion base
just under 2000 FT MSL. The PW had increased to 0.87 inch due to a
big jump in moisture above 12K FT, but a dry layer was indicated
below to the marine inversion. The sfc pressure gradient KSAN to the
deserts was still 7-8 MBS but the strongest SW winds were mostly in
the 25-30 MPH range at last report.
The local WRFEMS shows winds increasing overnight mts/deserts, so a
Wind Advisory is in place for late tonight through late Monday
evening with gusts to around 50 MPH possible. Most areas should see
some rain or sprinkles overnight, and given the deepening marine
layer forecast, this may get more widespread into Tue morning along
and west of the mts. A thunderstorm or two still looks possible into
the deserts through tomorrow afternoon, with the biggest threat
being lightning. Rainfall amounts overall are expected to be light.
The forecast was already updated late this afternoon to increase
POPS and QPF. No other forecast changes this evening.
From previous discussion...
...SHORT TERM (This Afternoon through Tuesday)...
Water Vapor imagery shows an upper low situated some 500 miles
off the coast of northern Baja. This feature will move east
northeast and over Southern California mid-late morning on Monday
before moving east during the afternoon. Thunderstorms were added
to the forecast for the San Gabriels, San Bernardinos, and San
Jacintos for this afternoon and that looks good as there is some
CAPE across these areas this afternoon. Then, tonight through
Monday (especially morning), there is a chance of showers across
all areas as the upper low moves overhead. CAPE is low (cools
aloft but it`s much cooler at the surface), so thunderstorms are
not a slam dunk, but there is a slight chance. This could turn
into more of a drizzle event more than anything, but with steadier
light rain along the southwest coastal slopes.
Moisture isn`t all that high, so rainfall amounts will be light.
Upslope flow will lead to light rain along the southwest facing
slopes of the San Bernardinos with max amounts forecast to be
0.50-1.00 inches along the slopes west of Crestline. Elsewhere,
amounts will average 0.10" or less, but isolated locales could
receive 0.25-0.50". WRF and HRRR show cells with rates of only
0.10-0.20"/hr tonight-Monday. So no significant impacts are
expected from this upper low. It will move east during the
afternoon on Monday with showers ending during the evening.
West-Southwest winds will strengthen with strong winds expected
along the desert mountain slopes and into parts of the lower
deserts, particularly the San Diego County deserts. Have issued a
Wind Advisory for all lower deserts effective 11 PM tonight
through 11 PM Monday.
Much cooler conditions as onshore flow strengthens will be felt
on Monday with cool weather continuing on Tuesday, but Monday will
be the coolest day for most locales before temps slowly moderate
as heights slowly rise.
Added this evening...
The various model runs diverge into next weekend with the track
of another closed low that develops under the mean ridge over the
EastPac. The ECMWF solution keeps it offshore, while a number of GFS
Ensemble members move it along, impacting SoCal at some point over
the weekend. Forecaster confidence falters here regarding to what
degree it may influence our weather, but for now, slight chance POPS
are in the forecast by late Sunday. Also, onshore flow and some
marine influence is expected to prevail, keeping temperatures close
to the seasonal average, along with areas of night and morning low
clouds and fog.
The marine layer will become gradually shallower with night and
morning low clouds and fog not spreading as far into the valleys.
The marine layer will then deepen into next weekend as the next
low pressure system arrives.
&&
.AVIATION...
290250Z...Coast/Valleys...BKN low clouds moving ashore this evening
with bases 1500-2000 ft MSL and will continue to spread to inland
valleys as the evening progresses. -SHRA and isolated TSRA are
possible in all areas this evening into the day on Monday. Reduced
vis 3-5 SM at times are expected in some areas, with BKN-OVC bases
lowering to 1000-1500 ft MSL during showers. Coastal slopes may
become obscured in low clouds.
Mountains/Deserts...SCT-BKN high clouds tonight with bases AOA 10K
ft MSL. -SHRA and isolated -TSRA are possible this afternoon into
Monday, mainly over the mountains. Areas of west winds 15-25 knots
with gusts to 45 knots are possible overnight on the desert
mountain slopes and at times onto the desert floor, along with
moderate up/downdrafts and local LLWS. Highest wind gusts will be
Monday morning.
&&
.MARINE...
Areas of showers and a slight chance of thunderstorms tonight
through Monday evening. A Marine Weather Statement has been issued
for the threat. No other hazardous marine conditions are expected
through Thursday.
&&
.SKYWARN...
Skywarn activation is not requested. However weather spotters are
encouraged to report significant weather conditions.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...
CA...Wind Advisory until 11 PM PDT Monday for Coachella Valley-San
Diego County Deserts-San Gorgonio Pass Near Banning.
PZ...NONE.
&&
$$
PUBLIC...10/Gregoria
AVIATION/MARINE...APR
...Update to aviation forecast discussion...
.SHORT TERM...(This evening through Monday)
Issued at 336 PM CDT Sun Apr 28 2019
Main challenges through Monday afternoon remain to be precipitation
chances and intensities. Zonal flow over old frontal boundary, now
rather well mixed out over the southern Plains, leading to regions
of enhanced moisture return, with scattered high-based convection in
recent hours in east-central Kansas and other elevated storms in
central Oklahoma. Surface dewpoints above 40 remain the exception in
the local area, though gusty south winds were allowing values to
return to the middle 50s from southwest Kansas into northern
portions of Oklahoma as surface low pressure deepens in eastern
Colorado ahead of modest upper wave. A stronger upper wave over
eastern Montana has allowed a cold front to surface southeast into
northwest Nebraska early this afternoon.
Evolution of next several hours will be key to the late evening and
overnight period with the greater concern exists for the local area
as the weak upper wave translates over Kansas and low-level moisture
surges north ahead of the approaching cold front. Short-range
guidance has overall struggled with ongoing elevated convection but
has been rather consistent with rapid destabilization taking place
as moisture continues north. Steady to rising temps are quite
possible as a 50 knot low-level jet develops and may keep boundary
layer CIN quite low as storms approach from the west. 19Z RAP brings
ML CAPE to around 1000 J/kg with CIN less than 100 J/kg with rather
strong effective shear. This setup keeps the tornado threat non-zero
but expect hail and winds the be the main concerns. Low-level
convergence and upper flow orientations continue to suggest training
storm potential with precipitable water values in the 1-1.5" range.
Even the current precip has not brought much wetting rain to the area
over the past few weeks and the flash flood guidance values of a few
inches are legitimate, but given the weak synoptic forcing/training
potential, will keep the Flood Watch going as-is. The northern cold
front should being to push through the area late tonight and bring
precip to an end for the bulk of the area by early Monday morning
but have kept some chances in far southeast areas with the boundary
not far away under southwest flow aloft.
.LONG TERM...(Monday night through Sunday)
Issued at 336 PM CDT Sun Apr 28 2019
Biggest concern in the long-range portion of the forecast package
will be a chance for severe storms for the southeastern CWA, and a
flooding potential on Tuesday with a round of moderate to heavy rain.
A surface front near the I-44 corridor in MO will begin moving back
to the north as a warm front Monday night. Broad scale lifting in
the mid levels will occur over the area into Tuesday in response to
an embedded upper shortwave trough moving through the flow and over
the region. As a result, a widespread batch of rain is looking
likely early Tuesday over all of northeastern KS. Rain intensity and
thunderstorm coverage is expected to increase into Tuesday
afternoon, especially in east-central KS as a warmer and more moist
air mass arrives in eastern KS. Models are in a little better
agreement today with the northward extent of the warm front with
most bringing it to near or just south of TOP by 21Z Tuesday. CIN
will erode and surface based CAPE will increase during the
afternoon, especially south of a line from Lawrence to Emporia,
which will be the most likely area to experience strong to severe
thunderstorms Tuesday afternoon. The NAM and GFS are currently both
indicating the possibility of near 2000 J/kg of CAPE developing over
east-central KS with very little, if any, inhibition. Meanwhile, 0-
6km bulk shear values could approach 50-55 kts. Will be monitoring
this area and timeframe for the possibility of severe weather.
Additionally, moderate to heavy rainfall, especially that associated
with stronger thunderstorm activity, will add more concern about
flooding following previous rounds of rain and the resultant
moistening of soils.
The front will pass back to the south Tuesday night taking
convection with it and allowing for quieter conditions over the CWA
into Wednesday. Rain may not be done with the area just yet,
however, as a final round of mainly lighter rain will be possible
early Thursday before a surface ridge of high pressure builds over
the area Thursday afternoon. The ridge will bring in a drier air
mass along with a return to some sunshine.
Long range models are then hinting at a few weak fronts associated
with some northern stream systems moving through the area from
Friday through the weekend. Will monitor for rain/storm chances
during that timeframe as we get closer.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 640 PM CDT Sun Apr 28 2019
For the 00z TAFs, a complex of showers and thunderstorms are
expected to impact the TAF sites late this evening through the
overnight hours before diminishing Monday morning, with low-end
MVFR cigs likely and possibly even dropping to IFR. As a 45-55kt
LLJ tracks over the area this evening, anticipate LLWS concerns.
Winds should remain gusty near 20kts through much of the TAF
period, with winds backing from southeast to north with the
passage of a cold front.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
Flood Watch from 10 PM CDT this evening through Monday morning
for KSZ021>024-034>039.
&&
$$
SHORT TERM...65
LONG TERM...Teefey
AVIATION...Hennecke
Area Forecast Discussion
National Weather Service Tulsa OK
829 PM CDT Sun Apr 28 2019
.DISCUSSION...
What a difference over the course of the day today. Much of the
area started off cool and dry this morning and now with the warm
front lifting north thru the region, warm and humid air has
returned. Expect a much warmer night tonight compared to last
night.
Evening PoPs have been removed as the high based activity from the
afternoon has vaporized. Focus then turns to our N and W across KS
tonight. While most CAMs and the global models suggest a busy
night ahead across KS, these same models keep the convection
north of the border tonight. The 700mb warm pool (temps 10C or
higher) expands north and east tonight across OK...increasing
confidence in the latter solutions. Based on the majority of data
and the warming mid lvls the plan is to keep the going forecast of
lower end PoPs near the KS border aft 06Z.
Lacy
&&
.PREV DISCUSSION... /Issued 646 PM CDT Sun Apr 28 2019/
AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM/KROG.
Scattered to broken mid and high clouds along with breezy
southerly winds are expected overnight for the CWA behind a warm
front lifting into Kansas. The exception to the winds will be
KFSM where a more easterly direction is forecast to return
overnight. During the day Monday...increasing low/mid clouds are
forecast as the boundary pushes back into Northeast Oklahoma and
stall near Interstate 44. Near the boundary and north...MVFR
ceilings and winds between west and north will be possible
through the afternoon hours along with chances for showers and
thunderstorms. For now will carry VCSH and Prob30 for TSRA for
Northeast Oklahoma TAF sites. For the rest of the CWA
Monday...increasing mid clouds and breezy southerly winds are
forecast.
PREV DISCUSSION... /Issued 543 PM CDT Sun Apr 28 2019/
UPDATE...
Some tweaks have been made to the evening forecast, refining PoPs
per latest obs and short term hi-res model trends. See discussion
below.
DISCUSSION...
PoPs have been shaved off to the west of the current band of high
based showers and isolated storms. This activity was focused on
the leading edge of waa/isentropic lift on the 310K surface. This
lift will be focusing up toward the MO Ozarks toward and after
00z, with some evidence of this with recent storm development just
north of the KS border in far SE KS. Both the HRRR and
experimental HRRR suggest a busy night ahead across KS, with an
isolated supercell or two tracking east across southern KS
tonight with sig severe potential. This activity should stay
north of the border tonight. The current forecast has some low
PoPs up near the KS border late tonight and will leave those alone
for now given some uncertainty in other CAM solutions.
Lacy
&&
.PRELIMINARY POINT TEMPS/POPS...
TUL 64 79 64 76 / 10 40 60 80
FSM 61 80 65 81 / 10 10 30 60
MLC 64 79 66 78 / 10 20 30 70
BVO 64 76 61 75 / 30 40 70 80
FYV 61 76 63 75 / 10 30 30 70
BYV 59 77 62 78 / 10 30 30 60
MKO 63 78 64 77 / 10 30 40 70
MIO 62 76 62 75 / 30 40 60 70
F10 64 79 65 76 / 10 30 40 70
HHW 61 78 67 79 / 0 10 30 70
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...None.
AR...None.
&&
$$
LONG TERM....99