Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 05/07/22
Area Forecast Discussion...UPDATED
National Weather Service Brownsville TX
640 PM CDT Fri May 6 2022
.DISCUSSION...Updated for latest aviation discussion below.
&&
.AVIATION...Visible satellite shows some high clouds moving across
all three Rio Grande Valley TAF sites this evening due to the
thunderstorm development over the Sierra Madre mountains in
Mexico. Those storms are supposed to stay south of the Rio Grande
tonight, so VFR conditions with moderate southeasterly winds will
prevail for the next couple hours before an MVFR cloud deck builds
across the region and winds drop a bit. IFR conditions will be
possible early Saturday morning, especially at BRO. Some patchy
fog will also be possible across all of Deep South Texas Saturday
morning. Then ceilings will gradually lift by mid day Saturday and
southeast winds will become breezy.
&&
.PREV DISCUSSION... /issued 251 PM CDT Fri May 6 2022/
SHORT TERM (Now through Saturday Night): A few high value heat
index readings are coming in from the Davis instrument at Falcon
Lake, but not widespread enough to consider a heat advisory for
portions of Starr County. The HRRR is signaling a few convective
cells, already seen on radar over Nuevo Leon, continuing into this
evening, but not quite making it across into deep South Texas. Low
clouds will move in over eastern sections of the CWA tonight, and
with lighter winds, patchy light fog may occur late tonight. Low
temps will be in the mid 70s.
In the meantime, the heat will ramp up on Saturday as an H5 ridge
continues to build overhead. The ridge will bring a swath of 850mb
temperatures between 25 to 27 degrees, especially in the Rio Grande
Plains, western Brush Country, and western Upper Rio Grande Valley,
Saturday afternoon. Taking those temps down a dry adiabat would put
surface temperatures near 40 to 42 C, or 104 to 108 for extreme
western sections, so maintained the current forecast for those
locations. Drier air with sub 70 deg F dewpoints will influence the
western sections, limiting heat index values somewhat, but Zapata,
and Starr Counties will flirt with heat advisory criteria (>= than
111 deg F) Saturday afternoon.
No rain or storms are expected on Saturday, but pressure falls over
the High Plains as the next storm system develops will help tighten
the local pressure gradient and bring breezy southeast winds to
coastal sections on Saturday. Saturday night low temps will again be
5 to 10 degrees above normal, in the mid to upper 70s, with moderate
southeast breezes and partly to mostly cloudy skies from west to
east.
LONG TERM (Sunday through Friday): A fairly persistent summer-
like weather pattern will continue for Deep South Texas through
the majority of the long-term period, maintaining abnormally warm
temperatures and near zero percent rain chances. Potent mid-level
ridging will be centered over central Mexico on Sunday, but will
gradually build northward across much of the central CONUS through
the upcoming workweek. As a result of this strong mid-level
ridging aloft, hot daytime and very warm and muggy evening
temperatures are expected to continue.
Additionally, a plethora of Gulf moisture in the lower
atmospheric levels will allow heat index values to climb above
105 degrees across all inland locations each afternoon through
Tuesday. The most extreme heat indices are expected to occur
across Zapata, Starr, Jim Hogg, and perhaps western Brooks and
Hidalgo Counties, especially Sunday and Monday afternoons, where
values up to 115 degrees will be possible. If model trends
continue, a Heat Advisory will be needed on both Sunday and
Monday for these counties. A Heat Advisory may still be possible
for Zapata and Starr Counties on Tuesday, though dewpoint
temperatures won`t be nearly as high as on Sunday and Monday and
will be trending cooler each afternoon through Friday. Finally,
breezy to windy southeast winds will also continue through much of
the long-term as a series of surface lows develop and march
across the Plains and Midwest through the week.
MARINE (Now through Saturday Night): Moderate to fresh southeast
breezes and moderate to slightly elevated wave heights will be
possible in the short term. Pressure falls in the High Plains will
tighten the pressure gradient Saturday afternoon, increasing
winds and seas. Small craft should exercise caution conditions
will be possible much of the short term.
Sunday through Thursday: A persistent moderate to strong
pressure gradient along the lower Texas coast will maintain
moderate and gusty southeasterly winds each afternoon, keeping
seas generally between 4 to 6 feet through the long term. SCEC to
borderline SCA conditions are likely each afternoon main due to
winds, especially Monday and Tuesday. Slightly more favorable
marine conditions are expected Wednesday and Thursday.
&&
.PRELIMINARY POINT TEMPS/POPS...
BAYVIEW/PORT ISABEL 75 92 75 90 / 0 0 0 0
BROWNSVILLE 77 94 78 94 / 0 0 0 0
HARLINGEN 75 97 75 96 / 0 0 0 0
MCALLEN 75 100 77 97 / 0 0 0 0
RIO GRANDE CITY 74 103 75 102 / 0 0 0 0
SOUTH PADRE ISLAND 77 83 77 83 / 0 0 0 0
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...None.
GM...None.
&&
$$
This product is also available on the web at:
https://weather.gov/rgv
Aviation Update...69-Farris
Area Forecast Discussion
National Weather Service Cleveland OH
1005 PM EDT Fri May 6 2022
.SYNOPSIS...
Occluded low pressure over the Ohio Valley will move east
towards the mid-Atlantic coast this evening through Saturday.
High pressure ridging will build into the Great Lakes region on
Sunday and into the eastern United States on Monday, remaining
there through the rest of the week.
&&
.NEAR TERM /THROUGH SATURDAY NIGHT/...
Update: Again freshened the near term POPs, QPF, and temps
based on current conditions and by blending in the best-
performing short-range models with the forecast through the rest
of tonight. This again resulted in no wholesale changes to the
forecast. Steadiest rain this evening has been with a nearly
stationary area of lower-level convergence extending from
Richland/Ashland Counties towards Sandusky and Toledo...this
appears to be gradually becoming less organized, with rain
filling in farther east now.
Still watching a few river points for potential to touch minor
flooding later tonight into Saturday. Warning has been issued
for the Portage River at Waterville. Otherwise, the Killbuck
Creek at Killbuck is forecast to eek into minor flood stage
Saturday morning. We will continue to watch that rise through
the night and issue a warning if confidence in reaching flood
stage becomes sufficient. We continue to watch several other
river points...the Huron River at Milan, Black River at Elyria,
Eagle Creek at Phalanx Station and Black Fork Mohican at
Loudonville are all in/forecast to get into Action Stage, and
one or two of these may also try getting into Minor Flood Stage
later tonight into Saturday. Otherwise, probably a fair amount
of nuisance standing water/ponding from the Sandusky area down
towards Mansfield and Ashland where the steadiest rain has been
this evening...if rain ramps back up enough in the Akron,
Canton, Ravenna and Warren/Youngstown area later tonight into
early Saturday some nuisance ponding may occur there as well.
We continue to watch winds along the western lakeshore and in
the islands, but currently they`re behaving quite well and no
changes were made to the going wind forecast. Still, a few gusts
to near 45 MPH may occur on the islands and right along the
lakeshore in parts of Ottawa, Erie, and perhaps Lorain Counties
overnight tonight. Other item of interest, mainly in Ottawa,
Sandusky, and Erie Counties, will be water levels on the lake
tonight. After peaking earlier today water levels have dropped
half a foot or so through the afternoon evening. Likely will be
another slosh back west late this evening into the overnight
with near-gales out of the northeast on the lake. Will be close
to causing at least some minor issues in typical spots for a
time overnight. Will monitor trends and may need to issue an SPS
for that.
Previous Discussion: Radar and gauge QPE show widespread
accumulation of 0.5-1"+ with the greatest accumulation of
1-1.25" from Marion to Canton and points south, with isolated
higher amounts across parts of central Ohio (through 19Z).
The vertically stacked low pressure system located over southern
Indiana will continue to moved eastward across the Ohio Valley
this evening and to the mid-Atlantic region tonight. The TROWAL
associated with this system will continue to fuel moisture into
an area of significant lift produced by the deformation zone.
While radar shows a lull in rain showers right now,
redevelopment of widespread rain is expected after 00Z across
the area in response to these synoptic features and lasting
through about 12Z before diminishing from west to east through
the day Saturday. Additional QPF of 0.3-0.8" is expected across
the area though lower amounts likely for northwest Ohio and
higher amounts of 1"+ may be possible for parts of central to
east-central Ohio. Localized areal and river flooding may be
possible for areas that receive the 1"+ of additional rain.
River ensemble forecasts via the GEFS and NAEFS suggest KILO1 is
likely to reach minor flooding but will wait for more QPE and
see how the river responds before issuing a river flood warning.
PHAO1 will also be a site to watch for river flooding.
By Saturday afternoon, much of the area will be left with light
rain showers, or even sprinkles/drizzle as the moisture depth
becomes increasingly shallow. Dry air sharply intrudes from the
northwest, eroding away at remaining showers and cloud cover
Saturday evening through Saturday night, with mostly clear skies
actually expected by late Saturday night.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
Sunday will be the start of the long advertised pattern change. The
mid/upper closed low will stall offshore of the Mid Atlantic coast
through the day while mid/upper longwave troughing remains from the
eastern Great Lakes down the east coast. As this occurs, upstream
mid/upper ridging will build across the Midwest and western Great
Lakes in response to a deepening longwave trough over the western
CONUS. The axis of the upper ridge will remain just to our west on
Sunday, with strong 1028 mb surface high pressure over Quebec
keeping light E to NE low-level flow across the area. This will lead
to mostly sunny and dry conditions, but continued below normal high
temps in the low/mid 60s.
Sunday night through Monday night, the big western CONUS mid/upper
longwave trough will further deepen allowing the mid/upper ridge
axis to sharpen and strengthen across the Plains and Midwest,
folding over into the Great Lakes and Ohio Valley. At the same time,
the old upper low remains cut off and quasi-stationary offshore of
the Mid Atlantic. This will be a classic, highly amplified Omega
Block pattern which will be very slow to move through next week and
beyond. Our region will be on the eastern periphery of the mid/upper
ridge with surface high pressure over far eastern Canada providing
dry and mostly sunny conditions. The warmest 850 mb temps will surge
into the middle and upper Mississippi Valley, but even northern Ohio
reaches 12-14 C 850 mb temps by Monday night. This will lead to
highs Monday warming into the low/mid 70s, and continued to go a
couple degrees above blended guidance. Lows in the low/upper 40s
Sunday night will modify into the mid 40s/low 50s Monday night.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
The large mid/upper ridge will remain strong and centered over the
Plains and Midwest Tuesday through Thursday as strong troughing
remains entrenched over the West, reinforced by several shortwaves.
Guidance is coming into better agreement that the closed mid/upper
low offshore of the Mid Atlantic early in the week will sink toward
Florida and the SE CONUS during the second half of the week before
starting to retrograde toward the southern Appalachians by Friday.
The end result is warm and dry weather for our region nearly all
week, with temps gradually warming each day. Temps averaging about
10 degrees above normal Tuesday will be closer to 15 degrees above
normal by Thursday and Friday with lots of sunshine continuing. The
weak pressure gradient will allow for the development of afternoon
lake breezes each day, so kept slightly cooler conditions along the
lakeshore, but overall went a few degrees above blended guidance for
highs each day. Did introduce slight chance PoPs for isolated
showers/storms from about Mt. Vernon and points SE by Friday
afternoon as moisture advection tied to the retrograding cut off low
begin to increase, but nothing widespread or long-lived is
expected.
&&
.AVIATION /00Z Saturday THROUGH Wednesday/...
Persistent IFR continues for FDY, MFD, and CAK. CLE and YNG have
been bouncing between IFR and MVFR, with lower ceilings and
visibilities under rain occasionally touching IFR...otherwise,
MVFR has been the rule at those two so far this evening. TOL
and ERI have been VFR for much of the late afternoon and early
evening.
Generally will be little change tonight with drier air
advecting in from the northeast trying to keep TOL and ERI
VFR...TOL has the best chance to slip to MVFR for a time this
evening if steadier rain spreads in.
FDY, MFD and CAK will likely stay IFR through the evening and in
some cases through the whole night...FDY should improve later
tonight into Saturday as drier air works in, though MFD and CAK
will likely stay IFR into early Saturday and then gradually
improve later in the morning and through the afternoon,
eventually getting to VFR by later afternoon or early evening.
Either could touch LIFR ceilings in steadier rain tonight, but
not enough confidence to give prevailing ceilings that low at
either. With areas of rain continuing, expect the ceilings to
only climb gradually on Saturday, especially at CAK.
Kept YNG MVFR through the night, but potential does exist for a
period of IFR ceilings if steadier rain can develop for a time
later this evening into the overnight. Gradual improvement
through the day Saturday, likely going VFR by late afternoon or
early evening. CLE in a similar boat as YNG...likely MVFR most
of tonight, but with a period of IFR not ruled out under
steadier rain if it develops over the terminal at some point
over the next several hours. Drier air working in from north to
south should cause gradual improvement later tonight into
Saturday morning, back to VFR at some point Saturday morning.
Generally went with a mix of HRRR forecast soundings and GLAMP
guidance for specifics at each TAF site...both initializing
fairly well, though the HRRR may be a bit too optimistic with
ceilings while LAMP may be a bit pessimistic with ceilings and
visibility at times. Either way, a blend of the two seemed
reasonable.
Northeast flow continues through the TAF period at 10-20 knots,
strongest at TOL, FDY, CLE and ERI. Winds gradually subside
Saturday afternoon and evening. Gusts to 25-30 knots possible at
times tonight into Saturday morning at TOL, FDY, CLE, and
ERI...otherwise, gusts generally 20 to perhaps 25 knots at
times. Gusts gradually come down Saturday afternoon as well. GLAMP wind gusts
appear a bit too strong tonight into Saturday outside of perhaps
TOL, CLE and ERI.
Outlook...VFR is expected through Wednesday.
&&
.MARINE...
NE winds of 20-30 knots occasionally gusting to 35 knots will
continue on the lake through Saturday morning. This will generate 8-
9 foot waves across the entire lake with 9-10 foot waves possible in
the western basin. Water levels reached 65 inches at Toledo early
this afternoon, but these levels have since fallen to just below 59
inches above low water datum. Another rise in levels is expected
tonight into Saturday morning, and levels of 67-70 inches are
possible at times. Held off on a lakeshore flood warning since we
remain below the 72 inch criteria, and lake levels are lower than
the past few years, but localized areas between Toledo and Port
Clinton could see some nearshore impacts by tonight given the long
duration of these NE winds down the long fetch of the lake. NE winds
will decrease to 15-25 knots Saturday afternoon with waves falling
to 4 to 6 feet (highest in the western and central basins), then
winds and waves will finally diminish to 10-15 knots and 2-3 feet
respectively by late Saturday night. The Small Craft Advisories
still look good to expire at 03Z Sunday for Conneaut to Ripley and
at 06Z Sunday farther west across the rest of the nearshore waters.
NE winds increase a bit again to 15-20 knots Sunday with 2-4 foot
waves, but quiet conditions are otherwise expected Sunday night
through Wednesday as a large ridge of high pressure builds across
the lake with generally ENE winds of 10-15 knots during the day and
ESE winds of 5-10 knots at night.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...None.
PA...None.
MARINE...Small Craft Advisory until 2 AM EDT Sunday for LEZ142>148.
Small Craft Advisory until 11 PM EDT Saturday for LEZ149.
&&
$$
SYNOPSIS...Saunders
NEAR TERM...Saunders/Sullivan
SHORT TERM...Garuckas
LONG TERM...Garuckas
AVIATION...Sullivan
MARINE...Garuckas
Area Forecast Discussion
National Weather Service Grand Forks ND
931 PM CDT Fri May 6 2022
.UPDATE...
Issued at 927 PM CDT Fri May 6 2022
Went ahead and expanded the chance/slight chance pops across the
Devils Lake basin over the next few hours as echos upstream in
southern Pierce continue to the east. RAP model does indicate some
elevated CAPE which may fuel showers and thunderstorms into early
Saturday morning into the northern valley.
UPDATE Issued at 641 PM CDT Fri May 6 2022
Mid level moisture axis pushing into eastern ND with radar returns
generally very light with most activity likely virga as actual sfc
reports remain dry with NDAWN sensors in this FA showing no
accumulation. Some isolated pockets may see a shower or sprinkle
reach the ground with little to no impact expected. Another small
area of showers and thunder near Minot will be monitored to see
if activity makes it east into the FA after sundown.
&&
.SHORT TERM...(This evening through Saturday night)
Issued at 312 PM CDT Fri May 6 2022
Precip chances tonight, then stronger thunderstorms and fire
weather concerns for tomorrow.
Southwesterly flow aloft sets up tonight, with a weak shortwave
trough lifting into southern Canada and some upper level
divergence over the Northern Plains. South to southeasterly winds
will increase, and there is some dew points around 50 in our far
western counties. Some cumulus trying to get going in central ND,
although MU CAPE values are around 100 J/kg. With weak instability
and the main upper support moving into Canada, not too excited
about shower or thunderstorm chances this evening, although with
warm air advection it isn`t totally out of the question. Will
continue to keep some low POPs going across our north. Otherwise
it should be breezy to windy tonight and into Saturday as
southerly flow continues to ramp up.
A fairly vigorous shortwave will move into the Dakotas on
Saturday, with the surface trough axis just to the west of our
counties. Winds will continue to transport moisture into portions
of eastern ND, but there is some question of how far east the
higher dewpoints will go. With a southeasterly direction still
tapping into dry air over Ontario and eastern MN, our far eastern
counties could see RH values similar today, which has dropped into
the 20s and even upper teens. The fly in the ointment will be
increasing cloud cover and the possibility moisture gets further
east than expected. Winds will be strong, with 20 to 30 mph and
gusts up to 40 mph possible. Have elected to go with an SPS
highlighting fire weather concerns for Lake of the Woods,
Beltrami, Clearwater, Hubbard, Wadena, and eastern portions of
Becker and Ottertail counties.
Further west, moisture is more certain, and some of the models
bring 500-1000 J/kg of surface based CAPE into portions of the
Devils Lake and Sheyenne basins. Much will depend on how much
afternoon sun we actually get, but with 45 to 50 kts deep layer
bulk shear, cannot rule out a few strong to severe thunderstorms.
Heavy rain could also be an issue in portions of eastern ND, as
PWat values increase to 150-175 percent of normal. With convection
it will be impossible to tell exactly where the heaviest rain
falls, but there are at least some low probabilities of an inch or
more of QPF across southeastern ND.
.LONG TERM...(Sunday through Friday)
Issued at 312 PM CDT Fri May 6 2022
Pcpn should be ongoing Sun morning, although possibly not over the
entire region at that time. There will be several upper waves and a
couple of sfc frontal passages between this time and Mon night.
Exact placement of the baroclinic zone, and whether stationary
boundary is present, will determine the location and duration of
rainfall during Sun.
Although instability may be more focused south and east on Mon,
there may be enough, in conjunction with an upper wave and
deformational forcing to produce locally heavy rainfall. This brings
widespread 1 to 2 inch totals into the picture, with a high end shot
of 3 inches for a few spots. Area-wide totals of at least an inch
are about 80 percent certain, as indicated by the ECMWF/GEFS
ensembles.
REX blocking, as previously mentioned, will only serve to strengthen
the southwest flow mid to late next week, introducing even more
moisture and convective potential. The magnitude of the block will
ultimately determine the potential for more heavy rainfall, which
would exacerbate existing flooding while creating new areas of
concern.
Temps will remain close to seasonal normals through the end of next
week, with daytime highs mostly in the 60s, and overnight lows
staying above 40.
&&
.AVIATION...(For the 00Z TAFS through 00Z Saturday evening)
Issued at 649 PM CDT Fri May 6 2022
VFR with south winds persisting overnight and gusting again
tomorrow afternoon up around 30kts. Showers and thunderstorms
expected to hold off until after 18Z.
&&
.HYDROLOGY...
Issued at 312 PM CDT Fri May 6 2022
Ongoing significant flooding will continue through the remainder of
the week and the weekend for many locations. Overland flooding
continues in parts of the northern Red River valley with backwater
issues from the mainstem Red and tributaries. Otherwise, three areal
flood warnings were dropped after reports from local emergency
managers indicated flood waters had receded. The remaining four were
trimmed and extended 48 hours based on reports from those areas.
However, several roads in those areas remain closed due to being
washed out from the flood waters.
Temperatures will continue their warming trend into the weekend. The
overall weather pattern will become more active late this weekend
and again late next week.
Red River mainstem...
All points on the central and southern Red have crested. The
greatest high impact flooding along the mainstem Red continues to be
near Grand Forks (moderate flooding) with major flooding ongoing
downstream to the Canadian border. Oslo and Drayton have crested but
remain at major flood stage while Pembina is approaching crest and
should remain near crest for the next several days after that.
Minnesota tributaries...
All points along the Minnesota tributaries have crested and river
levels continue to recede, with levels continuing to lower over the
next several days. However, uncertainty remains with how future
precipitation over the weekend may impact the rivers at this time.
North Dakota tributaries...
The main action along the North Dakota tributaries continues to be
along the Sheyenne and Pembina Rivers.
USACE plans openings at Baldhill today and tomorrow to ensure some
flood pool capacity is still available for likely rains this
weekend. A re-rise to flood stage at several locations is likely
with the adjusted releases from Baldhill Dam. Downstream, Lisbon is
forecast to dip slightly below flood stage before rising again to
minor flood stage. Kindred is forecast to remain in major flood
stage for the next several days before receding. West Fargo has
dipped to moderate flood stage but another crest above major flood
stage is anticipated as upstream flows reach this forecast point.
Harwood remains at moderate flood stage and will see a second crest
at moderate as the wave crest works its way downstream toward the
mainstem Red.
The Maple River Dam spillway is flowing as designed, and nearing its
crest. The re-rise in the Mapleton forecast puts the crest at minor
flood stage as a result of the added flow making it to that point.
Major flooding continues on the Pembina River at Neche, along with
plenty of overland flooding and high river levels on smaller rivers
and streams across far northeastern North Dakota. Neche has appeared
to crest and is forecast to slowly fall over the next several
days.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...None.
MN...None.
$$
UPDATE...JK
SHORT TERM...JR
LONG TERM...WJB
AVIATION...JK
HYDROLOGY...Hopkins
AREA FORECAST DISCUSSION
National Weather Service Hastings NE
642 PM CDT Fri May 6 2022
...Aviation Update...
.DISCUSSION...(This evening through Friday)
Issued at 330 PM CDT Fri May 6 2022
Primary forecast challenges are low clouds/fog and effects on
temperatures on Saturday, thunderstorm chances Saturday night,
then potentially hot temperatures and occasional thunderstorm
chances next week.
Not surprisingly, clouds have been stubborn to lift/erode today,
owing to weak mixing and fact that low level trajectories suggest
we`re basically recycling cool/moist air from behind last system
back into the area. This has kept temps on the cool side and don`t
see much of an opportunity for quick rises this aftn E of Hwy 281
where clds will be most stubborn. W/SW zones have seen more
sunshine and may still top out in the lower 80s. For tonight, it`s
pretty likely that we`ll see a repeat performance of low stratus
and fog, esp. after midnight. The HRRR has done a pretty good job
over the past 12-18 hrs, and see no reason to deviate from it`s
trends over the next 12-18 hrs. It`ll be a little different
situation tonight in that we`ll have a higher/more steady SE wind,
which could argue against DENSE fog development. However, don`t
want to completely write it off given upslope component and at
least modest moisture advection. Have included "Patchy" to "Areas"
of fog for most of south central NE, and portions of our KS
zones, but kept any dense wording NW of the Tri-Cities where HRRR
has been most persistent in coverage/placement of lower vsbys.
Much like today, think the HRRR and RAP runs are probably onto the
idea of temps once again being hampered by lingering stratus. Have
gone near or below NBM 25th percentile, which gives upper 60s far
E/NE to low 80s far SW. 15Z RAP and 18Z HRRR are colder yet, and
suggest most of south central Neb. E of Hwy 183 won`t get out of
the 60s. For collaboration purposes, won`t go quite that cold yet,
but SErly component to sfc wind and continued trajectories from
modified cool/damp airmass argue for colder than model consensus.
Attention then turns to developing convection over the High
Plains along an advancing cold front during the late aftn and eve
hrs Sat, that is then forecast to move E/SE Sat night. Don`t see
much reason to deviate from previous thinking and SPC Day 3
outlook too much. Convection may struggle to develop, initially,
due to narrow/weak instability axis and poor convergence...but
with time, incr LLJ in tandem with arrival of weak disturbance in
SWrly upper flow should result in development around or just after
sunset over the Neb. Sandhills. Deep layer shear vectors largely
parallel to the initiating boundary and convergence from LLJ
argues for fairly quick upscale growth to a linear mode. The
parallel orientation will also lead to slow SEward shift, as it
will take some organization and/or cold pool development to get it
moving. All of this argues for a late show, probably after
midnight. Exactly how long this activity persists past midnight
and the southward extent remains the greatest uncertainty. H7
temps will be quite warm...13-15C(!)...and the best convergence
from the LLJ will gradually veer/shift N/NE with time towards the
I-29 and I-90 corridors. IF (and that`s a big IF) the convection
makes it into our area, the main threat would probably be gusty
winds of 40-60 MPH. Can`t rule out some marginally severe hail in
strongest cores given magnitude of MUCAPE, deep layer shear, and
mid level lapse rates, but think the better chances for both will
probably remain closer to the initial development to our NW. Some
hi-res guidance, including 18Z HRRR, shows a weakening outflow
bndry with little to no QPF (likely due to aforementioned hostile
mid level temps), esp. w/ southward extent. On the other hand,
NAMnest and EC runs have been more bullish with coverage/intensity
of QPF, at least over our Neb. zones. As such, didn`t make too
many changes to going PoP forecast.
This front/outflow could finally be the nudge we need to get the
better mixing and warmer temps into the area for Sun and next
week. Large scale subsidence and limited moisture should lead to a
very nice Mother`s Day with highs in the 70s and 80s under incr
sunshine. A weak front may approach, and ultimately stall out, the
area on Mon. The primary upper support looks to be well N, across
the Dakotas, so this front will probably remain dry. The lingering
bndry could play a role with mixing/temps, esp. for Tue. A
stronger push of Srly flow will move in for Wed and continue into
Thu...and these look to be the warmest days of the forecast with
highs well into the 90s. Can`t rule out some convection during
this time with several impulses nearby and ongoing WAA, but
details are quite murky this far out. Appears some sort of cold
front will move through late next week and knock temps down closer
to normal and bring our next chc for shwrs/tstms.
&&
.AVIATION...(For the 00Z KGRI/KEAR TAFS through 00Z Sunday)
Issued at 622 PM CDT Fri May 6 2022
Skies have cleared out, but stratus is expected to develop late
tonight into Saturday morning. There is a good potential to dip to
IFR ceilings for at least a few hours. Fog is also possible, but
with continued south winds, there is some question to how
dense/widespread it becomes. Therefore, the 2SM visibilities were
maintained for now.
Ceilings improve Saturday morning, and south winds gusting
25-30kts.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
DISCUSSION...Thies
AVIATION...Mangels
Area Forecast Discussion
National Weather Service Lincoln IL
753 PM CDT Fri May 6 2022
.SYNOPSIS...
Issued at 746 PM CDT Fri May 6 2022
Lingering light rain and drizzle is expected to end toward late
evening, as upper level low pressure pulls away from our region. A
clearing trend is expected from north to south overnight and
Saturday morning, leaving mostly sunny skies prevailing by
afternoon. Expect temperatures to rise well into the 60s on
Saturday, while breezy southeast winds on Mothers Day bump
temperatures into the lower 70s. A more significant warming trend
is expected early in the work week, with temperatures close to 90
degrees by Tuesday.
&&
.UPDATE...
Issued at 753 PM CDT Fri May 6 2022
Still seeing areas of light rain and drizzle across much of the
forecast area this evening, as a well defined vort max slides
along the Illinois/Missouri border. Lots of stratus still is in
place, but cloud heights over the northern CWA are showing
significant improvement, and the low clouds will continue to be
pushed south of the area the next several hours as skies clear
from the northwest. Recent forecast updates were to adjust the PoP
and sky trends the next several hours.
&&
.SHORT TERM...(This evening through Saturday night)
ISSUED AT 254 PM CDT Fri May 6 2022
Latest RAP analysis shows a closed 500-mb low remains positioned
over Illinois/Indiana. Water vapor imagery shows two upper level
vort max swirling over the region, the stronger one over TN
responsible for a sfc low (centered over KY at 3pm/20z), while a
weaker one just west of the IL River is helping support continued
drizzle and light showers. These waves will finally meander away
from the local area tonight, reaching the mid-Atlantic by early
Saturday morning. Precip should gradually end from west to east
tonight, subsiding everywhere by about midnight. Lows will drop
into the mid- 40s across most of the area.
Cloud cover is expected to depart by Saturday morning, though a
few lingering clouds are possible east of I-55 on Saturday.
Temperatures will be milder, but just how warm they get remains a
point of uncertainty, as mostly clear May skies compete with
continued northeasterly flow on the backside of the departing sfc
low. This is especially true across the northeastern portions of
the CWA, where the sfc flow may advect lake-modified air in. The
latest guidance (NBM, MOS) want to push high temps to near 70,
which seems a tad aggressive. An investigation of forecast
soundings show afternoon mixing to near 850mb, and extrapolating
the expected 850mb temps (around +6 to +7 degC) suggests sfc high
temps in the mid-60s. Ultimately, went with a high temp forecast
in the upper 60s to trend upwards from previous forecasts without
being quite as aggressive as the latest guidance. By Saturday
night, sfc winds shift to easterly, in part due to the weakening
influence of the sfc low to our east, as well as the increasing
influence of pressure falls over the western Plains. Lows are
expected to be in the upper 40s Saturday night, near normal for
this time of year.
&&
.LONG TERM...(Sunday through Friday)
ISSUED AT 254 PM CDT Fri May 6 2022
The main story for the extended period is going to be the
summer-like heat and humidity. Mother`s Day will have pleasant
temperatures, with highs near 70. Continued surface pressure falls
over the west central Plains will tighten the pressure gradient
over the heart of the country, leading to breezy southeasterly
winds in central IL. Forecast soundings suggest peak gusts around
35 mph on Sunday. Winds look even stronger on Monday, with
sustained southeasterly winds around 20-25 mph and gusts
potentially in excess of 40 mph.
Into next week, a Rex Block develops just off the east coast as
high pressure strengths over New England, north of a low just off
the mid-Atlantic Coast, the same low that is over Kentucky today.
With this blocking pattern in place, upper level ridging is
expected to develop and strengthen over the Midwest. Global models
continue to show the potential for 500-mb heights above 5900m
from Tuesday- Thursday, which, if verifies, would be among the
highest observed values for the month of May in central IL (per
the ILX sounding climatology). Both NBM and MOS guidance suggest
highs near 90 or into the low 90s on Tuesday and Wednesday, with
upper 80s on Thursday and Friday. That`s approaching record high
temperatures, though given the 500-mb heights forecast to be near
record levels as well, it seems appropriate. Regardless of whether
record-setting temperatures occur, it`s going to feel like
summer. Dewpoints are expected to climb into the mid-60s to low
70s for Tuesday through Thursday, pushing heat indices into the
upper 90s on those days. Ridging prevails through most of the
week, though confidence in the pattern evolution starts to
decrease late in the week as the low pressure system retrogrades
westward into the southeastern US.
In terms of precipitation, chances are low through at least
Thursday. Precip can`t completely be ruled out as disturbances
pass NW of the ridge axis (tracking from the western Plains into
the Upper Midwest). If any precip or cloud cover associated with
it manages to filter into our CWA, it could keep temps from
reaching the near-record values that are currently forecast.
However, prefer to lean on the strong synoptic signal for
anomalously warm temps rather than hedge temps lower than guidance
because of low confidence precip chances 4+ days into the future.
Subsidence associated with the strong ridging will also be a
factor, acting to limit precip development.
&&
.AVIATION...(For the 00Z TAFS through 00Z Saturday evening)
Issued at 613 PM CDT Fri May 6 2022
IFR conditions remain widespread early this evening, but ceilings
have edged above 1,000 feet west of a KPIA/KIJX line. With time,
cloud heights will increase from north to south across the
forecast area this evening, and should be above 3,000 feet at all
sites by 06-08Z.
North/northeast winds will remain gusty overnight, and gusts above
20 knots continue through much of Saturday in eastern Illinois.
Further west, winds should diminish to just under 10 knots
Saturday morning.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Geelhart
SYNOPSIS...Geelhart
SHORT TERM...Erwin
LONG TERM...Erwin
AVIATION...Geelhart
Area Forecast Discussion
National Weather Service Indianapolis IN
1145 PM EDT Fri May 6 2022
...Updated Aviation Discussion...
.Forecast Update...
Issued at 954 PM EDT Fri May 6 2022
The forecast remains in good shape. Although a few minor
adjustments were made to match observations. Low level clouds and
and isolated showers are still present over the region in
association with a surface low that moved through earlier this
afternoon. Forecast soundings show low level saturation with weak
ascent will persist into early Saturday morning thus expect low
clouds and a few isolated light showers to stick around overnight.
Cold air advection filtering in behind the surface low and
subsidence from a building ridge will begin to break up clouds and
dry out the region by daybreak.
&&
.Short Term...(This evening through Saturday night)
Issued at 255 PM EDT Fri May 6 2022
* Lingering scattered showers or patchy drizzle tonight.
* Dry and Decreasing cloudiness on Saturday
* Clear Saturday night
Surface analysis early this afternoon shows an area of low pressure
over Southern Central Indiana and Central KY. Cyclonic flow was
found across the forecast area and the region...extending north to
the southern Great Lakes and south to the deep south. Water vapor
shows a deep trough aloft over the Tennessee Valley with a plume of
tropical moisture streaming ahead of the low across Appalachia. The
warm sector across Central Indiana at this time was limited to
points south and east of New Castle to Columbus to west of Seymour.
GOES16 show abundant cloud cover across Central Indiana...with radar
shows scattered light showers across the forecast area. A
thunderstorm had developed over Rush county and was quickly move NE
into the cold sector and out of the forecast area.
Tonight...
Models shows the surface low slowly pushing east tonight...taking
the best forcing and warm sector with it to Ohio and WVA. The upper
support also still is expected to pivot east...exiting the area and
taking the strongest forcing with it. However the deep low looks to
continue to provide broad cyclonic flow across the area overnight.
forecast soundings and time heights continue to suggest plenty of
lower level saturation through the night...with pwats over 1 inch.
HRRR continues to suggest warp around sct/iso light rain showers
across Central Indiana this evening and early overnight. Thus will
continue to keep some shower chances this evening but slowly lower
pops overnight as the low finally begins to depart east after 06Z
and dry air is suggested to infiltrate the column via the forecast
soundings. With the warm sector expected to be to our
east...thunder will not be expected.
Saturday...
Models show cyclonic flow lingering across Central Indiana in the
morning before a strong ridge axis aloft stretching from the
southern plains across the Mississippi valley to the Western Great
Lakes begins to build across Indiana. Leeside NW flow will allow for
subsidence and surface high pressure to build across
Indiana...allowing for gradually clearing skies. Forecast soundings
start the day with lower level saturation...but show a dry column
late in the day. Thus will aim for a morning cloudiness with
clearing through the day. Given the expected cold air
advection...will trend highs at or cooler than the NBM...mainly in
the mid 60s.
Saturday Night...
Strong high pressure stretching from Quebec to the Ohio and
Tennessee River Vallies will reside across Central Indiana. Strong
ridging along with associated subsidence is expected aloft. Thus
Clear skies and light and cool east winds will be expected.
&&
.Long Term...(Sunday through Friday)
Issued at 255 PM EDT Fri May 6 2022
- Cool weather continues through the weekend
- Breezy conditions possible on Monday
- Summer-like temperatures next week, approaching record highs in
places
The long term will begin on the cool side, with an upper-level low
exiting to the east. East-northeasterly to easterly flow behind this
system will keep temperatures on the cool side through Sunday. The
warm-up begins on Monday, however, as high pressure settles in and
winds gain a southerly component. Said winds may be a bit on the
gusty side as a tight pressure gradient develops between our high
and surface low pressure in the northern Plains. Gusts over 20 kts
are possible on Sunday, and over 25 kts on Monday.
The upper-low exiting to the east is expected to cut off from the
jet stream and stall over the western Atlantic. This system will
then meander westward or southwestward for several days.
Temperatures and precip chances late next week depend on the
eventual track of this system. At the same time, a large trough digs
into the western United States and a narrow ridge is expected to be
situated between this trough and the cut-off low to our east. The
position of the low is important for a few reasons. If the low ends
up further east, the axis of the ridge can be closer to Indiana,
allowing increased southwesterly flow to reach our CWA. In that
case, temperatures would be on the higher end of guidance. However,
in the opposite scenario...the upper-low traveling further west...
the ridge would be positioned to our west. Surface winds would have
more of an easterly component to them. While temperatures would
still be well-above average, record highs would be harder to attain
in this case.
As of right now, the best chance for record-breaking temperatures
appears to be on Tuesday and Wednesday. Guidance largely agrees that
the ridge will be centered more or less over Indiana, which will
lead to the warmest temps. After Wednesday, the upper-low will begin
its slow westward motion. Guidance begins to diverge, but still
shows the ridge easing slightly westward with time.
Regarding precipitation potential, the upper-low`s ultimate track
comes into play here as well. The west coast trough will attempt to
make eastward progress, but if it is hindered by the cut-off
low...then any precipitation associated with it will also be
delayed. The bulk of guidance depicts thunderstorm activity
remaining in the Plains for a majority of the period, with little
eastward progress due to the presence of the upper-low. Since the
trough is further away than the ridge, both scenarios regarding the
path of the upper-low will act to delay the onset of precip in
Indiana...so will hold off on PoPs for now.
&&
.Aviation...(06Z TAF Issuance)
Issued at 1145 PM EDT Fri May 6 2022
IMPACTS:
* IFR to MVFR conditions across the TAF sites tonight.
* VFR conditions return by daybreak.
* 20-25kt gusts possible.
DISCUSSION:
Isolated rain showers will dissipate over the next few hours as a
surface low exits the region. Some locations have improved to MVFR,
but Cigs may stay borderline IFR/MVFR over the next few hours for
KIND and KBMG. Cigs will begin to improve across all TAF sites
thereafter. Winds will remain out of N/NE at 10-15 knots with 20-
25kt gusts possible in some locations.
High pressure in place over the Great Lakes is expected to build
across Indiana as the low exits the region. This will allow for
drier weather and a return to VFR conditions later today.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
Update...Melo
Short Term...Puma
Long Term...Eckhoff
Aviation...Melo
Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
858 PM EDT Fri May 6 2022
.SYNOPSIS...
Multiple lows will impact the region through Sunday. High
pressure returns through the middle parts of next week. Low
pressure system will sit off the eastern seaboard for most of
next week leading to continue cloud cover and chances for
showers.
&&
.NEAR TERM /THROUGH SATURDAY NIGHT/...
A nearly stationary boundary remains over central Virginia this
evening. Closed upper-level low pressure along with its surface
low will track along the boundary tonight. Deep layer shear
profiles remain quite strong, and the stable layer over central
Virginia (closer to the boundary) is quite shallow. Therefore,
storms with damaging wind gusts, hail, and perhaps even a
tornado are possible through this evening. A Severe Thunderstorm
Watch is in effect until 10 PM. This watch may need to be
extended a couple hours or so for portions of central Virginia.
Elsewhere, a deeper stable layer near the surface will cause
convection to be elevated. However, the flood threat continues.
Latest mesoanalysis shows anomalously high pwats around 1 to 1.6
inches, and plenty of low-level frontogenetical forcing is
expected along the 850mb boundary that will remain overhead and
along the 850mb low and 700mb low that will be tracking through
the region. Elevated instability is also adding a locally heavy
element to rainfall. These factors combined will cause more
moderate to heavy rainfall through the night. Additional
rainfall amounts around 1 to 3 inches are most likely across the
area. FFG remains higher around the VA Piedmont into southern
MD, so the flood watch is not in effect for these areas.
However, localized flooding is possible from the moderate to
heavy rain. Confidence for flooding is higher to the north and
west across the rest of the CWA where FFG is lower. There have
been several reports of flooding across the Potomac Highlands
into north-central Maryland already.
Another concern is for gusty northeast winds (mainly near and
northeast of the Potomac River) overnight. As low pressure
tracks along the boundary, rapidly falling pressures will cause
northeast winds to increase. Frequent gusts around 35 to 45 mph
are likely. Did issue a wind advisory across northeastern MD
where peak gusts around 50 mph are most likely. Several runs of
the HRRR how 40 knots in the mixing layer, despite the
stability, and other guidance shows 40 knots around the top of
the shallow mixing layer as well.
The upper-level low will slowly pass through the area Saturday
while coastal low pressure strengthens off the North Carolina
Coast. More rain is expected during this time, but rainfall
rates should diminish to a light rain by the afternoon as most
of the low-level fgen forcing moves offshore. Additional issues
with flooding are likely. The Watch continues through Saturday
morning for most areas. The Wind Advisory continues for gusty
northeast winds over northeastern MD. Elsewhere, gusty northeast
winds are expected, but most gusts will be around 25 to 40 mph
(highest gusts near and northeast of the Potomac River Saturday
morning, and across the rest of the CWA during the afternoon).
Some light rain may hang around Saturday night, and it will be
chilly with a north to northeast wind. Additional rainfall
amounts will be light.
&&
.SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/...
The coastal low and the upper level low will continue shifting
off- shore on Sunday. Shortwave energy on the backside of the
upper low will combine with a NE to easterly flow to produce
some continued showers through Sunday afternoon. It seems
showers should be focused east of the Blue Ridge Mtns on Sunday
with some showers potentially lingering into early Monday
morning. A general northeast to easterly flow lead to continue
cooler condition on Sunday in the 50s. Gusty winds over the
Northeastern half of our CWA may linger into Sunday afternoon
with gusts of 25 to 30 knots possible.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
As our slow-moving weekend system moves offshore and high pressure
builds behind it, Monday sets up an omega block pattern, keeping the
offshore low meandering along the Mid-Atlantic/Southeast coast. High
pressure remains in place keeping us dry, and eventually builds to
the north of the offshore wobbling low creating more of a rex block
pattern. Cool conditions thanks to N/NE flow will start the week
with below normal temperatures and gradually warm through the week.
The offshore low will eventually return to shore along the southeast
coast. Depending on how the low tracks, there is some potential for
precipitation (primarily south and east of I-95) Wednesday and
Thursday.
&&
.AVIATION /01Z SATURDAY THROUGH WEDNESDAY/...
Showers will continue to impact all terminals through early Sunday
morning. IFR ceilings and MVFR/IFR vsbys are most likely tonight
into Saturday. Conditions will gradually improve later Saturday
into Sunday, but MVFR conditions are still possible. The best
chance for a strong to severe storm will be around KCHO through
3z. Elsewhere, any storms will be elevated.
Gusty northeast winds will develop overnight into Saturday across
the northeastern terminals, with the strongest winds around
KBWI, KMTN, and KDCA (30-35 knot gusts). Gusty north to
northeast winds will spread farther south later Saturday into
the rest of the terminals. Winds should start to lesson into
Saturday night into Sunday.
Mostly VFR conditions are expected Monday and Tuesday, but sub-VFR
conditions are possible (particularly at night) depending on how the
low offshore develops.
&&
.MARINE...
Small Craft Advisory conditions are expected tonight. Gale force
winds will develop early Saturday morning over the northern Bay
and these winds will gradually shift down through the middle
portion of the Bay later Saturday morning and afternoon. A Gale
Warning is in effect. Northeast wind gusts around 40 to 45 knots
are possible across these areas. A Gale Watch remains in effect
for the lower Tidal Potomac River and Chesapeake Bay south of
Drum Point for Saturday afternoon, and a Gale Watch remains in
effect for the Bay and lower Tidal Potomac River Saturday night
through Sunday. Elsewhere, SCA winds are expected during this
time.
North to northeasterly flow will prevail through the period.
Channeling, as a result, will likely require SCA issuance over
portions of the waters Monday and Tuesday.
&&
.TIDES/COASTAL FLOODING...
An onshore flow will cause tidal anomalies to increase through
this evening as low pressure passes by to the south. The low
will remain off the coast through the weekend, causing elevated
water levels. Minor flooding is possible, but confidence is low
since the flow will be north of east.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...Flood Watch through Saturday morning for DCZ001.
MD...Flood Watch through Saturday morning for MDZ001-003>006-011-
013-014-501>508.
Wind Advisory from 4 AM to 6 PM EDT Saturday for MDZ008-507-
508.
VA...Flood Watch until 6 AM EDT Saturday for VAZ025-026-029-036>040-
050-051-502>504-507-508.
Flood Watch through Saturday morning for VAZ027-028-030-031-
052>054-501-505-506.
WV...Flood Watch through Saturday morning for WVZ050>053-055-
501>506.
MARINE...Flood Watch through Saturday morning for ANZ535.
Gale Watch from Saturday evening through Sunday afternoon for
ANZ530>533-538>541.
Small Craft Advisory until 6 AM EDT Saturday for ANZ530>543.
Gale Warning from 6 AM to 6 PM EDT Saturday for ANZ530>533-
538>541.
Gale Watch from Saturday afternoon through Sunday afternoon
for ANZ534-537-542-543.
&&
$$
SYNOPSIS...JMG
NEAR TERM...BJL/JMG
SHORT TERM...JMG
LONG TERM...CAS
AVIATION...JMG/CAS
MARINE...JMG/CAS
TIDES/COASTAL FLOODING...JMG/BJL
Area Forecast Discussion
National Weather Service Pendleton OR
225 PM PDT Fri May 6 2022
.SHORT TERM... This afternoon through Sunday night...
Rather unsettled conditions are expected to continue across much of
the CWA the rest of the afternoon and evening. So far T-storms
embedded in fairly widespread shower activity have been prevalent
across parts of central Oregon extending into the Blue Mtns and
adjacent foothills areas, lining up well with higher model CAPE
values of 500-800j/kg. This development has been in-spite of strong
70-90 knot bulk wind shear between 0-6km working to vertically
separate and weaken convective parcels as they develop. Latest HRRR
and HREF runs continue to keep a chance for stronger shower and T-
storms in place over much of the CWA focused over the aforementioned
areas into the early evening hours at which point waning daytime
heating brings the chance for stronger convective showers to an end.
Overall the rest of the short term period will be characterized by
active and showery conditions accompanied by gusty winds on
Saturday, and afternoon T-storm chances mainly over the mountains of
eastern Oregon. Snow levels appear low enough for wintry weather
near the passes however given the time of year impacts look very
limited and confined to the overnight hours, if at all. The main
focus through the short term will be on the previously mentioned
windy conditions Saturday afternoon and evening across the east
slopes of the Cascades and Columbia river Gorge extending into
the Columbia Basin and northern Oregon; gusts 35-45mph likely.
In the wake of the cold front and shortwave passage tonight zonal
westerly flow continues to facilitate showery activity across the
region, slowly regressing towards the higher terrain of the Cascades
and mountains of eastern Oregon headed into Saturday morning. Snow
levels lower to 4000-4500ft during this time period with snowfall
possible for the higher pass zones although accumulations likely
remain confined to heavier showers and grassy areas. Saturday strong
westerly cyclonic flow continues as shower development gradually
increases as the day progresses, peaking the afternoon, along with a
slight chance for a rumble of thunder or two near the mountains of
eastern Oregon. The convective environment doesnt look nearly as
conducive to T-storms as the day prior with the NAM suggesting CAPE
values around 100-400j/kg. Outside of the weak T-storm potential the
primary impact Saturday appears to be breezy to windy conditions
across much of the CWA in the afternoon and evening hours. Models
are in good agreement for widespread 35-45 mph gusts from the east
slopes of Cascades and Columbia gorge through north-central Oregon
and much of the Columbia basin and Blue Mtn foothills, aided by a
robust surface pressure gradient and mixed layer extending into a
region of 35-40 knot winds near 800-850mb, and weak to moderate
isotropic decent off the Cascades. The ECMWF/GFS ensemble 6 hour max
wind gusts depicts a rather tight spread between individual ensemble
members in this expected range helping to increase confidence in the
breezy to windy conditions; high confidence in 35-45mph gusts. The
Simcoe Highlands, Columbia Gorge, and Kittitas Valley could see
locally higher sustained wind speeds and gusts, 25-30mph and 45-
55mph respectively, so have issued wind advisories for these
locations. Winds decrease later in the evening and overnight as the
surface pressure gradient and winds aloft weaken.
Snow levels drop a bit lower Saturday night while showers persist,
bottoming out near 2-2.5kft. Fortunately warmer sub-surface
temperatures keeps any appreciable accumulation to the higher
elevations, limiting pass concerns. On Sunday another trough of low
pressure moves into the Pacific Northwest, increasing shower
activity during the afternoon hours. Models take most of the energy
and accompanying precipitation with this disturbance into the
southern portion of the CWA near the southern Oregon Cascades,
central Oregon, and Ochoco John-day highlands, although showers
likely extend north of this region into the Blues/Wallowas and WA
Cascades. For now most guidance keeps a good chunk of the Columbia
Basin dry but any northern deviation in the storm track could result
in showers being added to the forecast. Isolated T-storms again
cant be ruled out in the afternoon hours over the mountains of
eastern Oregon and near the Cascades crests as well. Shower activity
gradually decreases Sunday evening and overnight. 99/82
.LONG TERM... Monday through Friday... Large scale upper trough
will continue over the Pacific Northwest through Monday with a low
dropping into California. This will continue have a scattered
showers and a chance of afternoon thunderstorms over mainly Oregon
and mountains of Washington. The low should continue south,
elongating the trough with continued chance of showers/slight
chance of thunderstorms over the Blue Mountains yet Tuesday.
Models in agreement with the system finally shifting east on
Wednesday with mainly dry conditions and warmer temperatures.
Southwest flow on Thursday ahead of the next system to bring a
chance of showers back to mainly the mountains through Friday. 93
&&
AVIATION...00z TAFs...Showers with localized MVFR to IFR conditions
possible under heavier bands of rain with thunderstorms at or near
the vicinity of PDT and ALW through 03z with more scattered showers
at remaining sites. Most showers will be ending after about 05z. sct-
bkn cigs 050-080 will persist through most of the period. West winds
15-20kts with gusts near 30kt at RDM/BDN will continue overnight wit
the other locations seeing the strong winds move in after 12z
Saturday. Winds will increase further after 18z with widespread 20-
30kts with higher gusts. 93
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 44 56 35 55 / 90 50 20 30
ALW 46 57 38 57 / 90 70 20 20
PSC 50 63 41 61 / 60 40 0 10
YKM 43 60 33 58 / 50 20 10 20
HRI 47 60 38 60 / 70 30 10 20
ELN 39 54 33 54 / 60 20 10 20
RDM 38 52 28 48 / 80 60 30 70
LGD 40 51 31 49 / 100 80 20 40
GCD 40 51 30 49 / 90 90 30 60
DLS 47 58 40 57 / 90 60 40 60
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...Wind Advisory from 11 AM to 10 PM PDT Saturday for ORZ041.
WA...Wind Advisory from 11 AM to 10 PM PDT Saturday for WAZ024-026-
521.
&&
$$
SHORT TERM...99/82
LONG TERM....93
AVIATION...93
Area Forecast Discussion
National Weather Service Shreveport LA
942 PM CDT Fri May 6 2022
.UPDATE...
Expand light fog areas & add a slight chance pop 12-15Z in E TX.
SHORT TERM.../Tonight through mid morning on Saturday/
We have expanded the light patchy fog with T/Tds near saturation
in many locales. Most of this will not even be a problem and lift
very quickly with sunrise and heating under a near surface
inversion. However, the 18Z guidance has been light with 4 to 6
mi mist at most. The GFS and HRRR models have been showing a few
blips of QPF signal of light rain or maybe drizzle from what will
be a greater concentration of low clouds lifting and squeezing out
a few drops. And only from daybreak into the mid morning hours
along our weak returning warm front tail. There may be some more
isolated convective activity during the early to middle afternoon
near the Toledo Bend dam, but will differ the late morning and
afternoon timeframe to new 00Z runs. Otherwise light and variable
or maybe calm wind early in the day and then E/SE winds with lots
of evap from the freshly soaked soils, adding to the not yet even
here humidity. Reminder, Ozone Action Day in the mix as well, for
these light winds early with better mixing winds by late morning.
No other changes needed at this time. /24/
&&
.PREV DISCUSSION... /issued 727 PM CDT Fri May 6 2022/
AVIATION...
For the ArkLaTex terminals, a large 1024mb air mass north of the
Great Lakes extends down the MS Rvr valley behind a large parent
low in the Ohio Rvr valley and off the eastern seaboard. This high
pressure will retreat north by tomorrow allowing for our winds
from the E/SE 5-10KT to filter muggy Gulf air back inland. The
tail end of our recent fropa will lift back across E TX tonight
with some daybreak to mid a.m. vicinity showers with a fair aftn
expected area wide as upper level high pressure arrives. /24/
PREV DISCUSSION... /issued 435 PM CDT Fri May 6 2022/
UPDATE...
Added Ozone Action Day headline for several TX counties.
PREV DISCUSSION... /issued 317 PM CDT Fri May 6 2022/
SHORT TERM.../Tonight through Saturday Night/
Northwesterly winds along with dry northwesterly flow aloft has
settled over the region in wake of the recent upper trough and
cold front passage. This has resulted in mostly clear skies and
less humid conditions across the area.
Weak surface high pressure will settle over the region this
evening, and winds will become lgt/variable to calm. At the same
time, the recent frontal boundary will return northward into our
East Texas counties, generally along and south of Interstate 20.
The will bring some low clouds and patchy fog to those areas. With
clear skies, wet grounds from recent rains, and the sfc high in
place, conditions could be just enough for additional patchy fog
to develop across the remainder of the region, especially across
SE OK and Southern Arkansas near the center of the surface high.
The fog will lift by mid morning, with dry conditions continuing
throughout the day on Saturday. But, with the warm front returning,
the humidity and warmer conditions will return to portions of the
region. Temperatures will top out in the upper 80s to lower 90s
in areas behind the front, with locations across SE OK/SW AR/NE
Louisiana that are ahead of the front, topping out in the mid 80s.
The warm front will pull up stationary across the region Saturday
night, with the gradient in temps and humidity remaining. Expect
overnight near 60 degrees across SE OK/SW AR/NE Louisiana, with
the remainder of the region south of the front only falling into
the mid to upper 60s.
LONG TERM.../Sunday through Thursday Night/
Upper-level ridge to prevail across the region at the start of the
long-term period allowing for stable conditions areawide
characterized by mostly clear skies and hot temperatures. An
enhanced pressure gradient, resulting from a surface high across the
Appalachians and an area of low pressure east of the Rockies, to
bring persistent southerly winds around 10 to 15 mph across the
ArkLaTex. Increased winds will provide sufficient mixing to limit
afternoon high temperatures to the lower 90s through Monday.
However, with winds forecast to relax and upper-ridging to
strengthen from Tuesday into Wednesday, temperatures will approach
the mid 90s across most locations with possibly the exception of the
higher elevations in McCurtain county which will experience high
temperatures limited to the lower 90s.
At this time, dew point values are forecast to remain near or below
70 degrees throughout the long term period, which will
restrict afternoon heat index values from exceeding 100 degrees.
Otherwise, pattern to shift late in the forecast period as a closed
upper-low across the Atlantic is forecast to retrograde westward on
Thursday into Thursday night allowing for the possibility for
increased rain chances next weekend. /05/
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 60 89 68 94 / 0 0 0 0
MLU 58 85 61 92 / 0 0 0 0
DEQ 53 84 62 90 / 0 0 0 0
TXK 57 84 65 92 / 0 0 0 0
ELD 54 84 60 92 / 0 0 0 0
TYR 64 90 71 93 / 0 10 0 0
GGG 61 89 68 93 / 0 10 0 0
LFK 65 93 70 95 / 0 10 0 0
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...None.
LA...None.
OK...None.
TX...None.
&&
$$
24/20/05
...Update to aviation forecast discussion...
.DISCUSSION...
Issued at 253 PM CDT Fri May 6 2022
Key Points:
- Pleasant conditions return for the weekend.
- Well above normal temperatures are expected for much of next week.
Water vapor imagery at 19Z shows our departing upper trough
continuing into the Ohio River Valley and a weaker trough off the
Pacific Northwest coast, leaving a low-amplitude ridge to develop
over the southwest CONUS. This sets the stage for the pattern change
heading into next week. In the meantime, clouds have been slow to
move out of the area this afternoon and have adjusted highs a bit
cooler in the mid to upper 60s as a result. This is the main
challenge for the short-term part of the forecast. Hi-res guidance
(namely the HRRR and especially RAP) have hinted at cloud cover
sticking around into the evening, particularly toward central KS.
The RAP appears most robust with hanging onto low-level moisture
through the overnight hours, developing low stratus again in central
KS with eastern KS clearing out. If skies do clear enough, there
could be some fog in the morning as winds remain light. Not enough
confidence yet in seeing that develop on a widespread basis as it
will depend how much clearing can make its way into eastern KS, but
it`s something worth monitoring.
By Saturday morning, we should see a return to southerly winds as
the ridge makes its way overhead. Weak perturbations within
southwesterly upper flow result in lee surface troughing by evening
with a tightening pressure gradient through the day. This begins our
substantial warming trend with highs in the 70s, then into the 80s
on Sunday. Locations along the KS/NE border may be a bit cooler on
Sunday as energy passing to the north brings a small chance of
showers/thunderstorms early Sunday with clearing into the afternoon.
For the rest of the week, our current departing trough looks to park
itself off the Eastern Seaboard with the ridge becoming increasingly
amplified. This puts an omega block in place with our area on the
western periphery of the strong ridge. Ensemble data shows
temperatures above the 90th percentile for much of the week,
leading to increasing confidence in a prolonged stretch of very
warm weather. One potential caveat is that there are other weak
perturbations moving within the flow on the western side of the
ridge, which puts low chances of precip into the forecast Tuesday
and Wednesday. That could provide some relief if it occurs, but at
this point would anticipate that being short-lived. Most
locations should see highs in the 90s Monday through Thursday,
with Tuesday looking to be the hottest day as the thermal axis
moves into the area. The best rain chance this period comes late
in the week as a stronger shortwave in the western US pushes the
broad trough closer to the area, so we likely have to wait until
then to feel any meaningful relief from the heat.
&&
.AVIATION...(For the 00Z TAFS through 00Z Saturday evening)
Issued at 627 PM CDT Fri May 6 2022
Scattered to broken ceilings should remain in the low end VFR range
into the overnight hours, though can`t completely rule out them
briefly dipping to MVFR this evening. Will also keep an eye on
the potential for some early morning fog if skies can clear out,
but confidence is low in this occurring as well. Winds remain
light overnight before becoming southeasterly at 10 to 13 kts
during the day tomorrow.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
DISCUSSION...Picha
AVIATION...Reese