Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 06/02/21
Area Forecast Discussion
National Weather Service Binghamton NY
830 PM EDT Tue Jun 1 2021
.SYNOPSIS...
Dry quiet weather is expected through tonight. Rain and a few
thunderstorms are possible Wednesday and Wednesday night.
Another round of showers and storms are possible on Thursday
into Friday before hot and humid conditions settle in for the
weekend and early next week.
&&
.NEAR TERM /THROUGH WEDNESDAY NIGHT/...
815 pm update...
A few targets of opportunity and changes were made to the near
term forecast grids with this update:
Clouds are mainly high cirrus across CNY, and with dew points
coming in lower than expected (42-47F) dropped tonight`s lows
across most of CNY by a few degrees. Forecasting lows in the
mid-40s to lower 50s...except low to mid-50s for NE PA, where
the clouds are expected to be more extensive and thicker.
Made some adjustments to slow the timing of clouds, showers and
t`storms moving north on Wednesday based on the latest hi-res
model data; HRRR, RAP and NAM-3km. Forecast is still basically
on track for Wednesday, but am expecting a few breaks of sun in
the morning from the Twin Tiers north into CNY, with showers
arriving late morning to midday for NE PA...and not until mid to
late afternoon for much of CNY. POT Thunder chances looked
good; and continued to cap this potential at slight chance.
Bumped tomorrow`s Max Ts up a few degrees, considering the later
arrival of steadier showers...now very close to the latest
blended (NBM) guidance. This gives low to mid-70s for most
locations, with upper 70s from Syracuse east to Utica/Rome.
Latest guidance is not as wet Wednesday night for much of our
forecast area. The initial warm front and associated precip will
be lifting north in the evening. Then, behind this feature there
should be a lull, with just some isolated to scattered showers
activity. The exception will be across the far west (steuben to
yates and Seneca counties) where a band of rain and embedded
t`storms may continue, associated with a low pressure system
slowly moving east across Lower Michigan. Another batch of rain
showers and perhaps elevated t`storms may also surge north along
from the Mid-Atlantic and southern PA during the predawn hours
Thursday...overall the shower chances will increase for much of
the CWA heading toward daybreak Thursday. A bit more humid and
mild, with lows in the 50s to near 60.
QPF amounts remain largely unchanged through Wednesday night.
With basin averages of mainly 1/4 to 1/2 inch expected...there
will be some narrow stripes with locally higher amounts.
330 pm update...
Main concerns in the near term are focused on the next round of
rain showers and even a few weak thunderstorms Wednesday into
Wed night...along with warming temperatures and increasing
humidity.
Current synoptic setup across the region this afternoon places
a weak surface high over the wrn Great Lakes into the Northeast
and a nearly zonal flow aloft behind the departing s/w to the
east, but with heights aloft gradually rising. The trend of
rising heights will continue into tonight as a longwave trough
deepens over the central US and downstream ridging amplifies
across the Northeast. A steady southwest flow will develop from
the Ohio Valley into the mid Atlantic region as a warmer and
more humid air mass moves in from the south associated with a
lifting warm front.
Temperatures this afternoon have warmed nicely into the upper
60s to mid/upper 70s in some locations. Cloud cover will
increase later this evening which will keep the warm air in
place near the surface and only allow temperatures to cool into
the lower to mid 50s. The air mass will be relatively dry
initially early Wed morning, but strong/deep moisture advection
will quickly occur through the rest of the morning and combine
with an upper level short wave moving in from the southwest and
weak isentropic lift across VA and southern PA. The forcing and
moisture will generate a blossoming area of rain showers that
will fill in north to south Wed morning. This area of precip may
actually become more scattered in nature by the early afternoon
as some of the drier air mixes in. However, a continuous supply
of moisture from the southwest will create favorable conditions
for a second surge of widespread showers into the evening and
overnight hours.
There will also be the potential for a few isolated weak
thunderstorms Wed afternoon and into the night. ML CAPE values
during the day Wed will be on the low end of the spectrum...only 100
J/kg or so with around 30 kt of deep layer shear...with most of the
convection rooted in the boundary layer. The main threats will
be gusty winds and small hail. Going into the evening, surface
temperatures cool and a weak inversion forms just above the deck.
This will allow the convection to become elevated and therefore
inhibit the threat for hail or wind.
Will need to monitor the potential for localized flash flooding late
Wed and Wed night. Model sounding hodographs are fairly
unidirectional and there is a deep saturated layer throughout most
of the column. There could be a chance of some storms training and
producing efficient and brief/heavy rainfall rates.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
300 PM Update...
The short term starts with a slight threat for some severe weather
across southern portions of Northeast PA on Thursday. 0-6 km shear
is forecasted to be around 50 kts though most guidance has MUCAPE
less than a 1000 J/kg, with thick cloud cover limiting heating. Some
isolated high wind gust would be possible but the threat is very
marginal for our region. A bigger threat will be heavy rain. PWATs
are approaching 1.5 to 1.75 inches along with warm cloud depths
greater than 10K along with skinny CAPE. Thunderstorm motions are
expected to be fairly fast at around 30 mph but training of
thunderstorms is possible. Highest PWATs are still off to our east
and will continued to be monitored for any westward shifts.
A few showers and thunderstorms make it into Thursday night as a mid
level trough moves in and colder temperatures moving in aloft keeps
some instability through the overnight hours. Shear decreases
quickly as the trough moves overhead so severe weather is not
expected to continue into the overnight hours.
Afternoon thunderstorms are possible on Friday once again but with a
more stable air mass moving in, coverage will not be as widespread
with any showers and thunderstorms dissipating in the early evening
with the loss of daytime heating.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
300 PM Update...
The long term is looking very warm for most of the Northeast. A
strong upper level ridge builds in with 500 mb height anomalies
approaching 3 standard deviations above normal by the weekend. This
results in widespread daytime highs in the mid to upper 80s this
weekend and then getting into the upper 80s and low 90s by early
next week. These highs may even need to be bumped up higher as we
get later in the week given that models were too low with the high
temperatures during the warmer weather that we saw last week.
Dew points also look to be on the increase late this week into
early next week with mid to upper 60s possible. Even though high
pressure is in place, enough afternoon instability will be
around for a few isolated thunderstorms to develop in the late
afternoon across higher terrain like the Catskills and Pocono
Mountains.
&&
.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
VFR through most of the TAF period with winds under 10 knots.
However, ceilings should form and lower throughout the afternoon
to low end VFR and even some occasional MVFR ceiling levels.
This will be associated with some showers moving south to north
during the mid and late afternoon hours. These may have some
thunder and cause visibility restrictions but the confidence in
any convection is low with limited coverage. As a result, only
tempo groups for MVFR showers were included at this time.
Outlook...
Wednesday Night...Occasional restrictions possible in scattered
showers and possibly a thunderstorm.
Thursday...Widespread rain showers and a chance of thunderstorms
with associated restrictions.
Friday...Restrictions possible in showers and storms.
Saturday and Sunday...Mainly VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...None.
NY...None.
&&
$$
SYNOPSIS...BJT
NEAR TERM...BJT/MJM
SHORT TERM...AJG
LONG TERM...AJG
AVIATION...MWG
Area Forecast Discussion...UPDATED
National Weather Service Brownsville TX
811 PM CDT Tue Jun 1 2021
.DISCUSSION...Updated for latest aviation discussion below.
&&
.AVIATION...As the conv fades to the south of the RGV, it`s
leaving behind a mix of VFR/MVFR conditions for the Valley
airports. Both the HRRR and the RAP13 models are insisting on
redeveloping some conv just south of the Rio Grande over
Tamaulipas State in Mexico. Both of these models do not to be
initializing very well at this time, but generally keep the RGV
rainfree throughout the night. Some weak 500 mb vorticies will
eject out of the closed 500 mb Baja Low tomorrow to possibly spark
off some conv later in the morning and into the afternoon/evening
hours. So will include some PROB30 groups later in the TAF period
for both HRL and MFE. Overall aviation conditions will depend
heavily on the very short range conv trends, so aviation forecast
confidence is only so-so this evening.
&&
.PREV DISCUSSION... /issued 241 PM CDT Tue Jun 1 2021/
SHORT TERM (Now through Wednesday Night): A cluster of
thunderstorms moved through portions of the CWA this morning. The
storms resulted in mainly nuisance flooding in the mid-valley
area. Conditions have quieted down, but the HRRR maintains
isolated convection around the area through the day, with some
better defined moderate activity possible this evening. The BRO
CWA remains in an SPC general thunderstorm convective outlook area
through tonight. A mid level low is positioned over Baja
California, and disturbances have been making their way east
across Mexico to help trigger storms upstream which then move into
and through the CWA. Precipitable water was a decent 1.75 inches
at BRO this morning, and a moderate southeast wind will keep the
moisture coming in off the Gulf. Thus the NAM, for example, shows
isolated to scattered convection on Wednesday as well. SPC has a
portion of the CWA, the northwest corner, in a marginal severe
thunderstorm convective outlook area for Wednesday, with the
remainder of the BRO CWA in a general thunderstorms outlook area.
The mid level low will start to move east after the short term,
with higher pop chances later in the week. Feel that the model
consensus may be broad-brushing pops a bit, with short term
guidance a little more conservative, but it seems clear that
unsettled conditions will continue, with areas and times of more
focused activity. Overnight low temperatures will hold near normal
with Wednesday high temps near normal east and slightly below
normal west, especially where rainshowers persist during the day.
LONG TERM (Thursday through Tuesday): Although exact details are
still being ironed out, confidence continues to increase on a
very wet pattern and abnormally cool temperatures across Deep
South Texas through at least this upcoming weekend. Atmospheric
conditions will dry out and temperatures will warm up to near or
slightly above seasonal average by the start of next week.
Closed 500mb low over Baja California will finally drift eastward
over northern Mexico beginning Thursday afternoon as a
positively-tilted longwave trough swings over the Ohio Valley.
The positive tilt of the trough will be able to absorb and pull
the Baja low eastward toward Texas before closing off again as it
drifts over the state. A plethora of low-level moisture, plenty
of instability, and modest to strong lifting downstream of the
trough axis will cause scattered to numerous showers and
thunderstorms, potentially strong-severe and heavy thunderstorms
at times. Very heavy rainfall is a possibility, especially on
Thursday and Friday, as PWATs across Deep South Texas are forecast
to increase to or above 2.0 inches. WPC has included all of Deep
South Texas in a Marginal Risk of rainfall exceeding flash flood
guidance in their D3 (Thursday) Excessive Rainfall Outlook. At
this time, a Flash Flood Watch has not been considered, but that
may change over the next 24 to 36 hours.
Medium-range forecast models are in very good agreement that the
mid-level low will slow down and stall over central Texas Friday
afternoon/evening or by Saturday as a blocking pattern sets up.
And even though the best lifting and dynamics will be north and
east of the region this weekend, isolated to scattered showers and
thunderstorms will remain possible on both Saturday and Sunday as
the mid/upper low sits over the state. Strengthening subtropical
ridging over southern Baja California will gradually push the low
northward as the ridge drifts over northwestern Mexico beginning
Monday. The influence of the ridge will nose over southern Texas
and help warm temperatures up and dry the mid-levels out for the
start of next week. Nevertheless, will leave in a slight chance of
spotty showers for both Monday and Tuesday as low-level moisture
remains abundant.
Rainfall totals between Thursday and Sunday are still being fine-
tuned at this time, but early indications show general amounts
anywhere from one to three inches across the CWFA, with locally
heavier amounts in some places. Once again, will likely make a
decision on issuing a Flash Flood Watch in the next 24 to 36
hours.
MARINE (Now through Wednesday Night)...Broad high pressure will
support light to moderate southeast winds and low to moderate seas
through the period. Isolated to scattered showers and
thunderstorms will be possible from time to time.
Thursday through Monday...Favorable marine conditions will
prevail through a majority of the period courtesy of weak high
pressure over the western Gulf of Mexico. Increasing winds and
building seas will then occur beginning Sunday and continue into
Monday due to an intensifying pressure gradient, resulting in
Small Craft Exercise Caution and/or Small Craft Advisory along the
Lower Texas Coast.
&&
.PRELIMINARY POINT TEMPS/POPS...
BAYVIEW/PORT ISABEL 76 87 75 87 / 10 20 30 50
BROWNSVILLE 76 89 76 87 / 10 20 30 40
HARLINGEN 75 89 74 87 / 10 30 40 50
MCALLEN 74 90 74 88 / 30 50 50 60
RIO GRANDE CITY 73 90 72 89 / 50 50 60 60
SOUTH PADRE ISLAND 78 82 77 81 / 10 20 30 40
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...None.
GM...None.
&&
$$
This product is also available on the web at:
HTTP://WEATHER.GOV/RGV
Short Term/Aviation...60-Speece
Long Term/Upper Air...55-Adams
Area Forecast Discussion
National Weather Service Columbia SC
745 PM EDT Tue Jun 1 2021
.SYNOPSIS...
With southeasterly low level flow associated with a pressure
ridge offshore pressure ridge offshore increasing, scattered
showers and a few thunderstorms will develop across the region
Wednesday especially in the east Midlands. Moisture is expected
to increase through late week as an upper trough approaches from
the west. A frontal system may move into the area over the
weekend. This will result in a higher chance of showers and
thunderstorms Thursday into the Weekend.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
Satellite imagery shows southeasterly winds pushing moisture and
clouds inland from the coast with some cloud cover diminishing
with sunset. Overnight expect mostly to partly cloudy skies as
southeasterly flow continues pushing moisture into the area and
pwat values around sunrise to 1.25 inches. A few showers will be
possible toward daybreak in the eastern Midlands however with
weak dynamics and dry air near the surface to be overcome QPF
amounts will be a couple hundredths or less. With the clouds
overnight low temperatures will be in the low to mid 60.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/...
Wednesday and Wednesday night...Strong surface pressure ridge
centered off the coast of the Mid Atlantic region. Southeast low
level flow/moisture flux increasing across the eastern Carolinas
through the day with a weak warm front setting up near the
area along with relatively high theta-e air in the east Midlands.
It appears there will be a sharp moisture gradient though
across the western Midlands and CSRA with precipitable water
ranging from 1.15 in the Piedmont to greater than 1.5 inches in
the east Midlands and coastal plain. Increasing southwest flow
aloft late in the day with amplified upper trough well to the
west from the Upper Midwest to the eastern Plains. Possible weak
short wave in southwest flow aloft moving through the Upstate
with isentropic lift/surface convergence focused in the central
and east CWA. Raised pops in the east based on the increase in
mos consensus pops. Temperatures may be a tad cooler tomorrow
due to showers and noticeable spread in guidance. Instability
appears weak but a few embedded thunderstorms possible. Showers
should be mainly diurnal and diminish after sunset to the
northeast as weak short wave moves by to the north. Overnight
min temps warmer than previous nights with increase in
moisture...in the mid to upper 60s.
Thursday and Thursday night...Moisture may decrease in the
morning but expected to increase by afternoon as upper trough
moves further east into the Mississippi Valley increasing
southwest flow aloft. Still weak surface convergence across the
area associated with trough/weak boundary. Upper level jet
appears to be well northwest of the Carolinas but weak short
wave troughs possible. Model differences noted on location of
precip with GFS/GEFS drier than other models with focus more in
the coastal northeast SC through the day. The NBM is more in
line with the ECMWF with higher pops across the region. Think
moisture and lift will be sufficient for high chance/likely
pops mainly in the late afternoon and into the overnight.
Instability may be a little stronger than Wednesday but severe
thunderstorm threat appears low. some potential for locally
heavy rain in the evening with the ECMWF ensemble and Nam model
suggesting qpf > 1 inch in the north Midlands/Piedmont where
surface convergence may be enhanced and strong lift associated
with possible short wave trough. Max temps tricky with large
spread in distributions but think a little cooler than NBM
median upper 80s...so went low to mid 80s most areas except CSRA
where should be a little warmer. Temperatures should be above
normal at night slightly.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
Weak frontal boundary may move into the region Friday and then
may become diffuse. Upper trough to the north but some
uncertainty to degree of amplification. Moisture remains high at
least early in the period. Warm advection and stronger
instability possible Friday may lead to more thunderstorms
focused in the afternoon. Scattered mainly diurnal convection
over the weekend into early next week with ensembles showing
bermuda high offshore with southeast/south low level flow
transporting moisture into the region. Ensembles show deep low
in the southern Plains possibly closed off with some upper
ridging in the southeast. But chance/slight chance pops mainly
afternoon and evening each day seems reasonable and temperatures
near normal.
&&
.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
VFR is expected for a bit this evening, with IFR conditions
expected to quickly develop later tonight.
Surface analysis reveals a surface high across the Mid-Atlantic,
which is pushing into the Atlantic ocean. This trend is expected
to continue into the overnight hours, shifting low-level flow
southeasterly as opposed to the northerly or easterly that it
has been. As a result, low level moisture is expected to quickly
advect into the region, with mid-upper 60s dewpoints expected
in the area by tomorrow morning. On the southern edge of this
high pressure system, an inverted surface trough will then push
into the region and keep our weather active.
Sensible weather is a bit complicated, especially when compared
to recent weather. The high pressure and dry air is currently
keeping things calm, but as you may have already guessed, this
isn`t expected to continue. The rapid increase in moisture
between 00z and 06z tonight is expected to result in the
development of stratus at all TAF sites. This will first begin
at OGB around 07z and then overspread the other sites between
08z and 09z. I expect it to begin with MVFR cigs but quickly
become IFR thereafter. Guidance is in good agreement on this,
with the LAMP, MOS guidance, and HRRR all showing this.
Additionally, SREF and NBM give a >70% probability of this
occurring. So confidence is fairly high that we`ll see at least
IFR cigs between 08z and 13z tonight. I am not as confident as
it pertains to just how far down we go. Several piece of
guidance (LAMP, HRRR, and HREF) all indicate cigs falling into
LIFR territory. I think that is a bit intense, but there is too
much indicating it not to at least have a TEMPO group in there
for it at all sites. I think OGB has the best chance of seeing
LIFR conditions. Another uncertainty is whether it will be more
fog than stratus. I think this sets up nicely as a stratus
event, but with calm winds and a good inversion setting up, I
can`t rule out fog developing. I have 4SM in there to account
for this. Model soundings illustrate the differences, with some
higher res models cooling the surface enough for fog while
others keep us just warm enough to keep this a stratus event. If
some of the higher level clouds to our west make it this way,
that may be enough to favor a stratus event overall. Generally,
I lean towards this line of thinking but will keep the fog in
the forecast to account for the possibility.
Issues will persist for a bit in the morning, but should begin
to clear out towards 14z-16z as the inverted surface trough
promotes lift across the region, and as the surface warms. I
think showers are likely to develop as this feature pushes into
the region, but I have only included SHRA at OGB where the
highest chances are. Elsewhere, I would go VCSH and don`t see
the need for that at this juncture. Any winds should be
southeasterly through the period between 3 and 8 knots.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
GA...None.
SC...None.
&&
$$
Area Forecast Discussion
National Weather Service Charleston SC
1024 PM EDT Tue Jun 1 2021
.SYNOPSIS...
High pressure will give way to more unsettled weather by late
week. A return to more typical early June weather is possible
early next week.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
As of 1020 PM: Latest nighttime RGB indicated bands of cirrus
across the forecast area, with a few patches of stratus near the
coast and the lower Savannah River corridor. Later tonight, mid
and low clouds will increase sky cover to mostly cloudy. HRRR
sfc condensation pressure deficits lower through dawn, with low
values across the inland counties. I will expand the mention of
patchy fog across the inland counties late tonight. In addition,
CAMs indicate that shower activity will increase after 11z,
peaking in coverage during the mid to late morning hours on Wed.
Previous Discussion:
A well pronounced upper low/ TUTT low near the Upper Keys and
the southeast Florida coast will drift south through the night.
In response to this feature and surface high pressure that pulls
further away from Long Island and the Mid-Atlantic region, a
coastal trough out near the Gulf Stream will head slowly
westward, reaching near the local coastal areas closer to
sunrise.
There has been a few very light showers or sprinkles in a few
spots of South Carolina this afternoon, due to the proximity of
this trough and also the sea breeze boundary. Any isolated light
rain though will end this evening as divergence becomes more
pronounced over land and CINH increases. However, as the trough
draws closer to shore overnight, PWat will climb to 1.50 to 1.75
inches and isentropic ascent on the 300-305K surfaces increases
somewhat. That allows for isolated to scattered showers over
the ocean to make it onshore of parts of South Carolina,
especially the coastal counties well after midnight, or even
closer to daybreak. We have just 20-30% chances as a result.
While the diurnal cumulus/stratocumulus will fade this evening,
additional stratocumulus will advect onshore or develop through
the night. Some of these clouds will build down enough and form
into an expanding stratus layer far inland. This could result in
some fog forming late at night, and we have added mention of
"patchy" fog along parts of the northwest and western counties,
where the more favorable condensation pressure deficits are
found.
The boundary layer will decouple inland similar to the past few
nights, but coastal winds will stay up a bit and gradually
back a bit northeast with time as the coastal trough gets
closer. Given higher moisture content and varying amounts of
cloudiness, temperatures will not be as cool as the last two
nights. We`re expecting lows generally in the lower and middle
60s inland from US-17, with upper 60s to lower 70s closer to the
coast and in the Charleston/North Charleston metro regions.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/...
Wednesday: Models have consistently showed that this period will
mark the beginning of pattern change, from a long period of dry
conditions to wetter/higher chances for rainfall. The region will be
positioned between a deep Atlantic ridge well to the east and an
developing upper trough over the central portion of the country.
Between these two systems, deep SSE flow is expected to increase the
mean layer moisture, which will lead to increasing chances for
showers/thunderstorms. The best moisture and forcing is expected to
be over our SC zones, where we continue chance PoPs. Lower PoPs
again Wednesday night as heating/instability decreases.
Thursday: the region remains within a confluent upper flow region,
between the upper trough to the northwest and ridge to the east.
With sufficient upper forcing, instability, and deep layer moisture,
have continued afternoon high end chance to likely PoPs, highest
inland due to the southeast low level flow. Model cross-sections
indicate deep south-southwest flow above the surface, which could
result in a potential for some training of convective cells. If
training does occur, isolated areas of locally heavier rainfall
could result.
Friday: the upper trough to the northwest starts to weaken and move
northeast of the region, but the deep layer ridge holds strong well
to the east. Deep layer moisture is still in place, but upper level
forcing may be a little less than Thursday. However, models show a
weak surface trough/front advancing toward the area during the
afternoon, which could help to organize a broken line of showers and
thunderstorms. Although surface based CAPEs of 1000-1500J/Kg, bulk
shear less than 30 kts. Thus, chance for any isolated severe storms
seems low at this time. Model wind profiles again suggest the
potential for training of convective cells, which if happens, would
increase the threat for locally heavy rainfall.
High temperatures expected to be near to slightly below normal
through the period. However, low temperatures will likely be near to
slightly above normal due to increased low level moisture and
nighttime cloud cover.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
The large scale weather pattern and forecast details become much
more uncertain during this period as models begin to diverge. Model
consensus/blend indicate that the region will sit between an upper
low/trough over central U.S. and higher pressure over the southeast
U.S. and Atlantic. The upper trough is shown to generally weaken as
it elongates more north-south across the central portion of the
country by early next week. Meanwhile, the deep upper ridging seems
to build over the eastern half of the country. Sufficient deep layer
moisture appears to generally remain in place over the region, but
with an overall lack of any significant upper level forcing.
Therefore, it seems best to continue generally chance PoPs, centered
around the afternoon hours, through the period. High temperatures
expected to be near to slightly below normal through the weekend,
then likely creeping back to normal by early next week. Low
temperatures likely stay near to slightly above normal through the
period.
&&
.AVIATION /02Z WEDNESDAY THROUGH SUNDAY/...
Cloud cover should increase across the terminals tonight as a
sfc trough moves approaches the GA/SC coast. Forecast soundings
and MOS indicate that cloud bases will gradually lower this
evening into late tonight. During the pre-dawn hours, MVFR
ceilings are expected over KCHS and KJZI, with patchy fog or
ground fog expected at KSAV. A few light showers are possible
across KCHS and KJZI during the early daylight hours, no
visibility restrictions. Conditions should return to VFR by
noon.
Extended Aviation Outlook: Wednesday through early this weekend,
with increasing deep layer moisture and upper level forcing,
expect the chances for periodic flight restrictions to increase,
especially during the afternoon hours each day.
&&
.MARINE...
For tonight: The inverted trough will drift west through the
night, approaching the Charleston County waters closer to
daybreak. As is typical with these features, the progression
westward is slower than depicted by the models, so we have
delayed the veering of winds by several hours as shown by the
model consensus. So we hold onto easterly winds at less than 15
kt for much of the night before they turn more SE closer to
daybreak.
Seas as high as 4 or 5 feet into this evening will drop about a
foot through the night.
Mariners should be alert for isolated t-storms reaching the
AMZ350 and AMZ374 waters after 3 or 4 AM.
Highlights are not anticipated through the period. Deep layer high
pressure will generally remain well to the east-northeast of the
waters. This will produce moderate southeast to south winds of
mostly 15 kts or less and seas 2 to 4 feet. Increasing chances for
mainly late night and morning showers and thunderstorms.
Rip Currents: A low risk is presently forecast for Wednesday.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...None.
SC...None.
MARINE...None.
&&
$$
NEAR TERM...NED
SHORT TERM...
LONG TERM...
AVIATION...NED
MARINE...
Area Forecast Discussion
National Weather Service Corpus Christi TX
1025 PM CDT Tue Jun 1 2021
.DISCUSSION...
With most of the convection dissipating as it moves across the Rio
Grande, have lowered PoPs for most of tonight. Isolated to
scattered convection is still possible, particularly over the
west. If storms do make it into the area, some of these may be
strong. Convection is expected to pick up Wednesday, with
scattered showers and thunderstorms by mid morning. Some storms
could be strong to severe tomorrow, so SPC has placed us in a
marginal risk for severe weather. WPC has also placed us in a
marginal risk for Excessive Rainfall for Wednesday, so expect some
heavy rainfall at times. This could lead to ponding on roads and
rises in small creeks and streams.
&&
.PREV DISCUSSION... /Issued 623 PM CDT Tue Jun 1 2021/
AVIATION...
A tricky aviation forecast for tonight with high uncertainty in
the forecast. At this time, precipitation does seem to be probable for
late tonight/early Wednesday morning, it`s more the evolution of
the showers and storms that are questionable. It is possible that
we have a repeat of last night`s thunderstorms, though storms
could be weaker with a bit more inhibition present. Should the
storms present as they did last night, strong wind gusts, periods
of heavy rain, and some hail is possible. However, VFR conditions
are likely to continue through most of the period, with only
periods of MVFR conditions expected...particularly in and around
any convection that develops.
PREV DISCUSSION... /Issued 441 PM CDT Tue Jun 1 2021/
SHORT TERM (Tonight through Wednesday Night)...
Deterministic ECMWF/Canadian/GFS/NAM place the WRN CWA under the
RRQ of a 90kt 250mb jet streak overnight/Wednesday. The NAM
predicts PWAT values near/above normal during the period. Although
recent HRRR time-lagged ensemble and NAM CONUS nest did not
explicitly predict convection over much of the CWA tonight, feel
that the combination of significant SBCAPE/limited CIN before 06z
Wednesday (NAM deterministic), moisture and upper forcing may
result in scattered convection over mainly the WRN CWA overnight.
Anticipate convection over much of the region Wednesday
afternoon. SPC maintains general convection tonight and marginal
severe Wednesday, although would not be surprised if strong
convection develops overnight over the WRN CWA. Coastal Flooding
not anticipated based on recent/expected trends with respect to
Bob Hall Pier/Port Lavaca tides and wind/sea state. Maximum Heat
Index values Wednesday below 100F.
LONG TERM (Thursday through Tuesday)...
A trough centered around the Great Lakes region will lift to the
northeast, leaving a closed low to form over Texas in its wake. As
this happens, a series of disturbances will push through the area.
This, coupled with a moderately unstable atmosphere, a weak cap, and
an abundance of moisture, will provide the opportunity for showers
and thunderstorms to develop each day this week through early next
week. Some of these storms could become strong at times. Localized
flooding will be a possibility as soils are already saturated,
especially with slow-moving cells or training showers/storms. WPC
does have most of the area in a marginal risk for excessive rainfall
on Thursday, so will continue to monitor for that possibility.
Interests in low-lying/flood prone areas should continue to remain
vigilant and stay tuned to the forecast for the latest updates in
the coming days. Rain chances show a slight decreasing trend early
next week.
Max temperatures on Thursday and Friday will be in the 80s across
the area. Temperatures will warm into the 80s to lower 90s on
Saturday and will continue to warm through early next week, with
highs in the 90s inland and upper 80s along the Coastal Bend and
Victoria Crossroads.
As temperatures begin to rise, so will heat index values. Most of
the area will see heat indices near or just above 100 Sunday through
early next week.
MARINE...
Weak onshore flow will persist tonight through Saturday. Isolated
to scattered convection may develop overnight/Wednesday. Scattered
to numerous showers and thunderstorms will be possible Thursday
through through Sunday. Onshore flow will increase to weak to
moderate levels on Sunday.
&&
.PRELIMINARY POINT TEMPS/POPS...
Corpus Christi 73 85 73 82 72 / 30 40 60 70 50
Victoria 72 85 71 81 70 / 40 70 70 80 40
Laredo 73 89 72 85 71 / 50 60 60 70 50
Alice 71 88 71 84 70 / 30 50 70 70 50
Rockport 75 86 73 85 74 / 30 40 60 70 40
Cotulla 72 89 72 85 71 / 60 60 60 70 50
Kingsville 72 86 73 82 71 / 30 40 60 70 50
Navy Corpus 75 84 75 83 75 / 30 30 60 60 50
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...None.
GM...None.
&&
$$
LS/77...SHORT TERM
Area Forecast Discussion
National Weather Service Dodge City KS
1041 PM CDT Tue Jun 1 2021
...Updated Aviation...
.SHORT TERM...(This afternoon through Wednesday)
Issued at 1145 AM CDT Tue Jun 1 2021
Late morning water vapor satellite imagery and upper air analysis
depict a trough over the northern and central plains, with a trio
of vorticity maxima moving through the flow. These features have
maintained the thick stratus/drizzle over southwest KS this
morning, and light winds within the saturated boundary layer have
fostered patchy fog over some areas. Despite upper level support,
models agree the stratus deck will lift with time today, allowing
for a few breaks in the clouds and at least some diurnal
insolation. This will bring afternoon highs closer to normal with
most areas reaching the upper 60s to low 70s, although this is
somewhat dependent on how quickly the stratus can thin, and light
low-level winds will not support deep boundary layer mixing
lending some uncertainty in afternoon temperatures.
Mid-afternoon shower/thunderstorms development is also possible
mainly over the central/eastern zones, as forcing for ascent
increases ahead of a vorticity max digging south-southeast during
the day and overspreads roughly 500-1000 J/Kg of MUCAPE. Given the
lack of any clear boundary/convergence zone, coverage will likely
be limited, and most areas will stay dry. Weak mid/upper level
flow will also limit wind shear and therefore storm organization,
so no severe threats are expected. Later tonight, various CAMs
suggest a weak/decaying MCS will move into far western KS, but
again these storms will not pose any severe threat. Overnight,
mostly cloudy skies will begin to deteriorate as the upper trough
begins to exit to the east, and morning lows will drop into the
upper 40s and low 50s.
As the upper trough continues to move away during the day
Wednesday, subsidence behind it, as well as ahead of a building
ridge over the western states, will finally allow for mostly
clear skies and appreciable daytime heating. Afternoon highs will
reach into the mid/upper 70s, which is much closer to normal (mid
80s) for southwest KS this time of year. Guidance depicts
500-1000 J/Kg of MUCAPE will again develop over southwest KS
Wednesday afternoon amongst 20-30 kts of bulk shear, but once
again a lack of any initiating boundary and/or upper level forcing
will limit convective coverage.
.LONG TERM...(Wednesday night through Tuesday)
Issued at 201 PM CDT Tue Jun 1 2021
The upper level pattern at the beginning of the long term period
will consist of a trough over the eastern CONUS, with a ridge
building over the Pacific Northwest/Great Basin and a weak cut-off
low over northern Baja, Mexico. These features will move slowly
east through the end of the work week, bringing dry, tranquil
weather to southwest KS. Height/thickness rises will allow skies
to stay mostly clear with warming afternoon highs from the low 80s
Thursday to mid 80s Friday. By Saturday, the upper level pattern
flattens out somewhat as the upper trough moves over the Atlantic,
and broad ridging dominates the CONUS with a weak cut-off low
meandering over central TX. This will not translate to much change
in the weather for Saturday/Sunday, as mostly clear skies and
afternoon highs in the mid/upper 80s are expected. It is worth
noting that the weak cut-off low will drift slightly northward on
Sunday, and a slight chance of afternoon thunderstorms clipping
our far southeast zones will materialize. Weak instability/shear
will preclude severe potential with any thunderstorms that can
make in into southwest KS.
Early next week, spatiotemporal differences emerge between
guidance members regarding the cut-off low ejecting into northward
into the central plains, and a separate shortwave moving into
southern CA/Desert Southwest. Unsurprisingly, the GFS is the most
progressive, while the preferred ECMWF solution is more reserved.
In either scenario, thunderstorm chances will increase mainly
across our central/eastern zones, and may pose a low-end severe
threat.
&&
.AVIATION...(For the 06Z TAFS through 06Z Wednesday night)
Issued at 1040 PM CDT Tue Jun 1 2021
Satellite and radar imagery at 0330z showed thunderstorm activity
from near Scott City to near Syracuse to near Elkhart, moving
slowly southward. HRRR suggests some of this activity will be
close enough to GCK/LBL over the next few hours to warrant a
VCTS/CB mention at the beginning of the 06z TAFs. Impacts will be
brief and limited, if any. Otherwise, expect areas of stratus,
fog and drizzle to redevelop overnight, with very light winds
working in tandem with a saturated boundary layer. This potential
will be focused on eastern terminals (DDC/HYS), with no reduced
flight categories included for GCK/LBL. VFR is expected daylight
Wednesday, with continued very light winds, variable in
direction.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 52 76 54 82 / 20 20 0 0
GCK 49 76 52 81 / 20 10 0 0
EHA 50 78 52 82 / 30 10 0 0
LBL 50 77 52 82 / 40 10 0 0
HYS 53 75 53 82 / 10 20 0 0
P28 56 75 56 82 / 20 20 10 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Springer
LONG TERM...Springer
AVIATION...Turner
Area Forecast Discussion
National Weather Service Grand Rapids MI
752 PM EDT Tue Jun 1 2021
LATEST UPDATE...
Aviation
.SYNOPSIS...
Issued at 223 PM EDT Tue Jun 1 2021
- Risk for scattered afternoon showers both Wed and Thu
- Above normal temperatures over the weekend into next week
- Possible break in the heat with showers and storms late next week
&&
.DISCUSSION...(This evening through next Tuesday)
Issued at 223 PM EDT Tue Jun 1 2021
- Risk for scattered afternoon showers both Wed and Thu
Looks like best chances for showers and a few isolated
thundershowers on Wed will be along and east of U.S. 131 and north
of I-94 between 1pm-9pm. On Thu...the best chance will be generally
east of U.S. 127. Showers will be generally be light and quick
hitters on both days. Thunder wise it might bring a 30 mph wind gust
and a 30 min delay to outdoor activities but should not be any more
of an impact than that.
There will be a weak surge of moisture into the region tomorrow as
low pressure tracks through the Ohio Valley and stays south of
the area. There will also be a weak trough moving through the
region which combined with the low level moisture and afternoon
heating will produce instability showers (CAPE ~ 200 to 600 J/Kg)
based on dewpoints in the lower 50s.
How widespread and how robust the showers end up being depends
primarily on low level moisture. HRRR is driest with afternoon
dewpoints near 50F and just widely scattered shallow
showers/sprinkles. NAMNest is on the other extreme with dewpoints
nearing 60F and more numerous and deeper showers/storms. Other
CAMs and NWP are inbetween with dewpoints in the low to mid 50s.
Individual showers will be unorganized and short lived with weak
wind fields both surface and aloft through Thursday. New activity
will tend to initiate on the lake breeze and along the leading
edge of an afternoon moisture surge from the SSE as well as a zone
of differential heating along and north of I-94 resulting from
the contrast in partial sunshine over MI with thicker clouds and
cooler temps associated with the OH Valley low to our south.
Subsequent showers will occur along merging outflow of prior
showers (A Florida shower day in Michigan).
- Above normal temperatures over the weekend into next week
Almost time to take it to the bank...mid summer weather with a
string of mid to upper 80s beginning Friday and continuing well
into next week. Looking for a 90F reading...maybe but it does not
look like the airmass will be quite warm enough to support
widespread 90s this time around...but there`s still a chance at
least on Sunday.
The heat will be associated with a building longwave ridge aloft
over the east central U.S. The center of the ridge will end up a
bit SE of MI with a low level moist flow from the Gulf while a bit
higher up very warm air off the high plains (H85 temps ~16C)
arrives on more WSW winds. The result will yield average temps at
least 10 degrees above normal with the moisture holding overnight
lows in the mid 60s.
It will be dry as well with little chance for rain until a week
from tomorrow (next Wed). The upper ridge will suppress most
chances for rain and may also help setup the potential for poor
air quality towards Monday. Last thought...keep an eye on the
weekend camp fires and such...it has been very dry and the chance
for fire spread will be increasing through the weekend.
- Possible break in the heat with showers and storms late next week
Wash...rinse...repeat is how this pattern feels. The current
pattern evolution looks very similar to the our last bout of heat
in mid May. Eventually the upper ridge spreads westward and
flattens mid to late next week. That then allows or provides
opportunity for several frontal waves riding over the ridge to
drop southeastward with a backdoor cold front and a chance of
storms much like our last warm stretch ended. We`ll see but that
is not a bad analog looking at the end of next week.
&&
.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 752 PM EDT Tue Jun 1 2021
For the most part VFR will continue to prevail tonight and
Wednesday. However after 18Z Wednesday some MVFR cigs and
scattered showers will begin impacting areas along and south of a
AZO to LAN. Near calm winds tonight becoming southeast 5-10 kts
on Wednesday. However winds at MKG becoming onshore/southwest in
the afternoon.
&&
.MARINE...
Issued at 223 PM EDT Tue Jun 1 2021
Minimal wind or wave concerns next 36 hours with high pressure
now over the region and only weakening over time. Winds will
mostly be 10kts or less and be onshore in the afternoon and
offshore late night and early morning. Any showers will stay well
inland on both Wed and Thu. Some local shallow or patchy fog is
possible Wed morning.
Looking like south to southwest winds of 15kts or so are more likely
late Thu through Sat as a new area of high pressure strengthens to
the southeast of MI. The airmass will become more moist as well but
the mixing associated with the increased wind gradient should
squelch development of any substantial fog over the relatively cool
lake waters. On that note...water temps at the coast should start to
warm towards 60F with the onshore flow and very warm weather over
the weekend.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...None.
LM...None.
&&
$$
SYNOPSIS...Cobb
DISCUSSION...Cobb
AVIATION...Meade
MARINE...Cobb
Area Forecast Discussion
National Weather Service Houston/Galveston TX
619 PM CDT Tue Jun 1 2021
.AVIATION [00Z TAF Issuance]...
Some showers are finally beginning to develop on cold front,
currently over UTS and south of CLL. Some lightning is not out of
the question, but should become less likely as sun goes down, so
have largely pulled any mention of thunder from this set of TAFs.
Expect low VFR/MVFR near and in the wake of the front briefly, but
should see a return to VFR deeper into the morning. Expect rain
chances to come back in the afternoon thanks to front stalling in
the area - detailing the specifics on this will be difficult, but
high confidence in the general idea of a stretch with multiple
rounds of showers and storms this week.
&&
.PREV DISCUSSION /Issued 326 PM CDT Tue Jun 1 2021/...
.SHORT TERM [Through Wednesday Night]...
A weak wind shift was aligned from about Lufkin to Houston to
Sargent and this boundary was moving slowly east. Showers and
thunderstorms will continue to develop ahead of this feature as it
moves into LA later this afternoon. Further north, a weak cold front
extended from Palestine to Caldwell to Kerrville. Models are not
handling this feature well and but current thinking is that the
boundary will continue a slow march toward the coast before stalling
somewhere near or northwest of the I-69 corridor. With some
additional heating this afternoon, it seems reasonable to expect
shra/tsra to redevelop along the weak front as suggested by the 16z
and 17z HRRR runs. Precipitation will wane between 05-08z with the
loss of heating. Jet dynamics still show some upper level divergence
this evening so think there could be a burst of locally heavy rain
through the evening.
Upper level winds become neutral or even slightly confluent toward
morning so there should be a minimum in rain chances early Wednesday
with things picking back up again toward the afternoon with a bit of
heating. SE Texas will go into a RRQ by afternoon so lift along the
weak front will be increasing during the afternoon and into the
evening. The jet streak responsible for the rain on Wednesday will
pull away from the region and the flow aloft will become semi-zonal
and rain chances should diminish but not completely end as another
short wave moves into the area from the west. Will stick with chance
PoPs for now but these may need to be raised. Soils are saturated
over much of SE TX and the potential is there for additional heavy
rain but the gap in rainfall today and the significant model
differences has lent enough uncertainty in the forecast to forgo a
Flash Flood Watch at this time. A Watch will likely be required at
some point this week but don`t think we are at that point just yet.
MaxT values will remain climo through Wednesday with clouds and
precip and overnight MinT values will probably remain near or just
above climo due to cloud cover. 43
.LONG TERM [Thursday Through Tuesday]...
Southeast Texas will continue to be prone to periods of showers
and thunderstorms through this long term period (could end up
being across some parts of our area almost every day) in connection
with a slow moving closed low and associated disturbances. A persistent
onshore flow, precipitable water values generally in a 1.5 to 2ish
inch range, a possible weak low level convergence boundary setting
up somewhere in the area and the potential for a healthy and somewhat
prolonged divergent flow aloft all support elevated rain chances.
With this slow moving (maybe even stationary) storm system setting
up, locally heavy rainfall will be possible, especially where any
banding or training forms. With lots of area grounds mostly saturated
from recent rains, it will not take much more to cause some flooding
issues, especially in/around already swollen rivers, creeks and bayous.
For the rest of this week and through the upcoming weekend, widespread
4 to 6 inch rainfall totals can be expected, and locally higher amounts
will likely happen. Flash Flood Watches might be needed.
Stay tuned to the forecasts as the week progresses as changes are
likely to happen. Make sure you closely monitor how much rain falls/
accumulates in and near your area. 42
.MARINE...
Another extended period of wet weather is expected over the next
week or so. A mainly southeasterly flow will persist for the remainder
of the week and over the weekend while a series of disturbances bring
the possibility of storms across the area. Higher winds and seas
will be possible in and around the storms. Look for an increase in
winds and building seas over the weekend as the result of a tightening
pressure gradient. 42
&&
.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL) 68 84 67 82 69 / 20 40 40 60 30
Houston (IAH) 70 85 69 83 70 / 50 50 50 70 30
Galveston (GLS) 76 84 76 82 74 / 30 40 40 50 40
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...None.
GM...None.
&&
$$
SHORT TERM...43
LONG TERM...42
AVIATION...Luchs
MARINE...42
Area Forecast Discussion
National Weather Service Indianapolis IN
1048 PM EDT Tue Jun 1 2021
...Updated Aviation Discussion...
.Forecast Update...
Issued at 932 PM EDT Tue Jun 1 2021
Look for the rain showers to spread northwest across central Indiana
late this evening and overnight as warm advection pattern continues
and the atmosphere saturates down. The HRRR 300K isentropic analysis
had a good handle as displayed in the condensation pressure deficit
dropping below 30 millibars overnight. This is akin to the
atmosphere saturated and radar is supporting this trend as echoes
are gradually showing up further northwest over the Wabash Valley.
Look for the precipitation to also increase in intensity overnight,
especially over southern sections, where the precipitable water will
climb over 1.5 inches. This area will also at the nose of a modest
low level jet to the northeast of a surface low that will lift
northeast across Arkansas. In addition, impulses in southwest flow
aloft ahead of an approaching trough will also contribute.
&&
.Short Term...(This evening through Wednesday night)
Issued at 229 PM EDT Tue Jun 1 2021
Central Indiana has become encompassed in SW upper level flow,
pushing a warm moist air mass aloft. This has lead to the ongoing
cloud cover for the entire day, of which will continue through this
evening and tonight. Even with extended cloud cover, the incumbent
warmer air mass has allowed for a slight increase in high
temperatures today, with most locations topping off in the mid
70s.
Above 10000 feet, the air is nearly saturated causing some rain way
above the surface. However, dew points in the low 50s near the
ground has evaporated any precipitation prior to reaching the
surface. This should start to change as a surface low develops
within the low level WAA over southern IL. This surface low will
provide increased lift and near surface moisture transport, enough
to push dew points into the 60s. In return, rainfall should begin to
reach the surface, beginning in SW portions of central Indiana,
progressing to the NE overnight. PWATs will be in the 90th
percentile and the troposphere will be nearly entirely saturated
later tonight. This will lead to more efficient droplet growth
within the cloud layers, leading to heavier rain rates. Overnight
into tomorrow morning, between 1-2 inches of rain is expected over
SE portions of central Indiana, with lesser amounts to the north and
west.
Thunderstorms chances will increase tomorrow afternoon, as a narrow
window of instability will form over southern central Indiana and
points southward. This is associated with an improvement of ML lapse
rates ahead of a deepening surface low and some increased diabatic
heating in the afternoon. The presence of an upper level jet will
provide a better shear profile, but margin of error for a zone of
instability will be minimal given lapse rates around 6.5 C/km.
Current expectations are for isolated convective cells to develop
within scattered to widespread rain showers. A near saturated layer
will limit severe capable downbursts. Biggest threat for tomorrow
will be localized flooding due the previous night`s rainfall and
possible heavy rain rates for extended periods.
Consistent cloud cover and increasing surface dew points will limit
temperature gains tomorrow. Expect afternoon highs to be around 70
for most locations.
&&
.Long Term...(Thursday through Tuesday)
Issued at 229 PM EDT Tue Jun 1 2021
Rain will continue into the day Thursday as the base of a large
upper level trough passes through the area. Much of the
precipitation should be wrapping up by Thursday evening with models
showing that the best forcing should be well into Ohio by then.
Precipitation will come to an end by Thursday night with generally
dry and warm conditions expected for Friday into the weekend.
Models have come a bit more in line compared to yesterday when it
comes to the weekend forecast. The trough that originally looked to
linger over the area should fully exit by Friday with a ridge of
high pressure building Friday into Saturday. Can`t rule out an
isolated diurnally driven shower or storm on Saturday, but the cap
looks to be strong enough to keep things dry. Sunday into Monday,
warmer surface temperatures and better moisture flow will allow for
slightly more widespread diurnal showers and storms, but not
expecting overall coverage to be more than 20-30%.
Confidence in the forecast towards the end of the period is low with
divergent model solutions, especially by Tuesday. Currently think
the ridge will slowly move to the east with southerly flow brining
even more near surface moisture to the area. The bulk of the
showers and storms should remain to the east, but with such low
confidence in the forecast, the 30% POPs seem reasonable but will
try and concentrate them in the 18Z-00Z timeframe when diurnally
driven convection looks most likely.
&&
.Aviation...(00Z TAF Issuance)
Issued at 1048 PM EDT Tue Jun 1 2021
IMPACTS:
- Flying conditions deteriorating to MVFR and worse after 07z as
showers overspread the terminals.
- Thunderstorms can not be ruled out, especially after 18z. That
said, chances too low to put in the TAF`s.
DISCUSSION: Warm advection will result in widespread showers and
deteriorating flying conditions starting early overnight. Embedded
thunderstorms will also be possible as surface low pressure and
upper trough approach the Ohio Valley this afternoon. Winds will be
southeast overnight and today less than 10 knots.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
Update...MK
Short Term...Updike
Long Term...White
Aviation...MK
Area Forecast Discussion
National Weather Service Marquette MI
723 PM EDT Tue Jun 1 2021
.SHORT TERM...(This evening through Wednesday)
Issued at 434 PM EDT TUE JUN 1 2021
Water vapor imagery and RAP analysis show a ridge over western N
America with max 500mb height anomaly of 230m centered over western
WA. This ridge is forcing broad troffing downstream across central
into eastern N America. Within this trof, a shortwave is over
Manitoba and the Dakotas. This feature will be of interest for the
fcst here on Wed. Well ahead of the shortwave, there have been weak
height rises across the fcst area today. As a result, it`s been a
quiet aftn under sct-bkn cu. Stabilizing flow off Lake MI has
prevented any cu development closer to Lake MI. Temperatures have
risen into the 70s F across the interior. Lake breezes are noted
across the board under weak pres gradient/light wind regime, leading
to cooler conditions with temps in the upper 50s/lwr 60s lakeside.
Vis satellite imagery shows some fog across portions of northern and
eastern Lake Superior. Earlier, some fog was also noted over
northern Lake MI, but that has since dissipated.
Tonight, upstream shortwave will be approaching Lake Superior by 12z
Wed. Weak height falls are noted across the fcst area tonight, but
there is little increase in winds above the nocturnal inversion
despite the approaching shortwave, and there is very little theta-e
advection. Thus, not expecting any shra development tonight though
some of the models do generate a few shra. Will be something to
monitor. Expect min temps ranging from generally the 40s south half,
coolest e to the low/mid 50s near Lake Superior where stirring
southerly winds will keep conditions warmer.
Shortwave arrival on Wed with mid-level trof axis approaching,
reaching the western fcst area in the evening, will correspond with
the diurnal heating cycle. Consensus of 12z guidance is for MLCAPE
to increase to roughly around 500j/kg. With instability on the
limited side and deep layer shear generally under 25kt, organized
storms and a svr risk are not anticipated. Greatest coverage of shra
will be over the roughly the w half of the fcst area. Stabilizing
southerly flow off Lake MI will work to keep the eastern fcst area
dry though a few shra may develop near Lake Superior as lake breeze
will attempt to move onshore, resulting in local increased
convergence if it does so. Expect high temps in the 70s, except 60s
lakeside of Lake MI.
.LONG TERM...(Wednesday night through Tuesday)
Issued at 436 PM EDT TUE JUN 1 2021
Broad troughing overhead at the beginning of the extended (00Z
Thursday) moves east of our CWA by Friday afternoon. Despite weak
NW flow aloft behind this wave, low level WAA kicks in immediately
with 850 mb temperatures warming to near 16C by Friday afternoon
and near 19C by Saturday afternoon. 850 mb are typically around
10C at this time of year indicating a prolonged stretch of much
warmer than normal temperatures is expected to begin late this
week. 00Z NAEFS guidance indicates 850 mb temperatures above the
90th percentile between Friday morning and Wednesday night. A
subtropical trough becomes embedded within the SW flow aloft
resulting in surge of Gulf of Mexico moisture early next week.
I`ll start with the precipitation chances for Wednesday night
through Thursday. Moist west-southwest low level flow will be in
place across the CWA at 00Z Thursday as a compact, but energetic
shortwave trough approaches from the northwest. Uncertainty in the
timing and track of the shortwave exists, but scattered showers and
thunderstorms are expected as the shortwave moves through. Wind
shear is not particularly impressive, but should be sufficient for
some frisky thunderstorms with small hail/gusty winds on Thursday
afternoon. Storms should clear out of our area Thursday evening as
the front moves through.
Interestingly, the fropa acts more like a warm front than a cool
front with substantial WAA expected Thursday night into Saturday
morning. A surface low tracking south of the Hudson Bay on Saturday
sends a cold front south that then stalls near our CWA. It`s unclear
whether or not the frontal boundary will make it across Lake
Superior, but substantial moisture pooling along the front will make
for a muggy Saturday. The 12z ECMWF indicates convective initiation
amidst >3000 J/kg of MUCAPE and ~30 knots of bulk shear on Saturday
afternoon. Hodographs indicate weak veering with height that may
support supercell structures. The 12z GFS was much less enthusiastic
and the CMC is a somewhere in the middle.
Another surface low tracking into the Hudson Bay is expected to lift
the front well to our north on Sunday resulting in another hot and
humid day. However, the real fun and games begin when a plume of
Gulf of Mexico moisture is advected north late Monday into Tuesday.
This surge of moisture is associated with a subtropical shortwave
trough that gets sheared apart while becoming embedded in SW flow
aloft. Overall, the synoptic scale pattern is very similar to the
surge of Gulf moisture we received in mid-May. It`s therefore
unclear whether or not the substantial influx of moisture will
result in beneficial rainfall, but there are some indications of an
increasingly active pattern by the middle of next week. Either way,
a return of the muggy-meter 3000 will be needed this weekend into
the middle of next week.
&&
.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 707 PM EDT TUE JUN 1 2021
VFR conditions are generally anticipated through the forecast
period. That said, by tomorrow afternoon, showers and
thunderstorms will become increasingly likely as a disturbance
approaches and crosses the region. Coverage will be the question
with uncertainty as to which, if any, of the terminals will end
up being directly impacted. Therefore, have included VCSH mention
to provide some heads up but definitely not warranted just yet to
include anything more. With the convective nature of the activity,
will likely be a bit challenging to nail down those specifics
until that time gets closer.
As for winds, either light and variable overnight or with a
general south to southwesterly component, picking up slightly
early tomorrow (although not looking to exceed 10 knots, for the
most part), prevailing generally out of the southwest.
&&
.MARINE...(For the 4 PM Lake Superior forecast issuance)
Issued at 434 PM EDT TUE JUN 1 2021
Expect winds across Lake Superior to be mostly under 20kt for the
next few days. A couple of periods of stronger winds are then
possible. The first will be Fri night. Low pres moving across
northern Ontario may result in a period of sw wind gusts to 25kt at
high obs platforms, perhaps up to 25-30kt for a short time btwn the
Keweenaw and Isle Royale. The second period of stronger winds may
occur at some point Sat night into Sun as fairly deep low pres moves
from south central Canada toward Hudson Bay with its associated cold
front approaching. Although the air mass will be very warm,
resulting in very stable conditions over the waters, sw to s winds
could gust to 25kt at times at high obs platforms.
Fog may become an issue in the coming days as air mass over the area
becomes increasingly humid, but fog will definitely be more of an
issue once rainfall occurs into the chilly marine layer.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
None.
Lake Michigan...
None.
&&
$$
SHORT TERM...Rolfson
LONG TERM...EK
AVIATION...lg
MARINE...Rolfson
Area Forecast Discussion
National Weather Service Nashville TN
743 PM CDT Tue Jun 1 2021
.UPDATE...
FOR EVENING DISCUSSION.
&&
.DISCUSSION...
Evening sounding from OHX shows considerable moistening of the
mid-levels since this morning, with some instability now evident
in spite of unimpressive mid-level lapse rates. Showers have been
skirting west and north of Middle Tennessee, but the HRRR finally
brings more widespread activity later this evening and especially
overnight. Have adjusted the POP`s accordingly as showers develop
from west to east. HRRR does suggest a few heavier cells embedded
in an area of mainly light showers, so we`ll leave TS in the grids
from 06Z onward. Current forecast appears to be in good shape.
We`ll update the public forecast later mainly for wording. No
major changes are planned for now.
&&
.AVIATION...
00Z TAF DISCUSSION.
BNA/MQY/CKV/CSV...A surface system approaching from the southwest
has already brought scattered activity to portions of Middle
Tennessee west of Nashville, and look for showers to penetrate
deeper into the mid state as the evening progresses and deeper
moisture filters into the area. Expect ceilings to gradually lower
to MVFR by Wednesday morning, with winds increasing from the
south, and TS possible in the afternoon.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
DISCUSSION......08
AVIATION........08
Area Forecast Discussion
National Weather Service Phoenix AZ
501 PM MST Tue Jun 1 2021
.UPDATE...
Updated Aviation discussion.
&&
.SYNOPSIS...
Temperatures will warm through the middle of the week with afternoon
highs in the 102 to 107 degree range along with moderate heat risk
for many places through the rest of the workweek. A persistent weak
upper level low and a slight uptick in moisture will result in a
chance of isolated showers and thunderstorms over the higher Arizona
terrain most afternoons. Showers and storms are most favored to
remain north and east of Phoenix but an isolated shower or
thunderstorm may survive into the lower desert areas near Phoenix.
A cooling trend is possible late in the weekend and early next week
as low pressure increases from the west.
&&
.DISCUSSION...
The upper level RAP mesoscale analysis indicates N to E flow
aloft on the north side of a closed cut-off low circulation over
offshore Baja. A small vort max in NW MX is rotating out in front
of the low. The skies are mostly clear across our region with
northerly flow across the western States in advance of the strong
ridge of high pressure building inland. Theres also some weak
elevated CAPE south of Gila County. METSAT showed mostly clear
skies across the region with convective CU and isolated mostly
light showers/sprinkles and an isolated storm cell on radar
returns forming across N and E and SE AZ. Mid-level WV shows some
slightly elevated moisture across the lower deserts and some
light patchy moisture with the cut-off low near Baja.
Local ACARs soundings evolution showed W flow below 700 mb and NE
flow above that with some elevated moisture near H5 and an above
average PW near 0.65" which is near to slightly increased from
yesterday. Yesterdays high in Phoenix was 101 degrees. The
month of May ended with 11 days of 100 degree plus days which is
very near the normal of 100+ degree days for May in Phx. Today
the warm-up continues with a highs of 102 to 104 in and around
Phoenix and 103 to 106 out west.
The models agree on the Baja cut-off low remaining mostly stationary
through Thu as the ridge maintains strength over the West while only
shifting slightly east also through Thu. As a result there is good
confidence of the elevated heat persisting into Saturday. This will
result in up to moderate heat risk and highs of 103-106 degrees in
Phoenix and the lower deserts, and up to 104-109 out west. Highs are
then expected stay close or just under this range on Sat.
The lingering low pressure system will also make for low-end
shower/storm chances each afternoon and evening through the late
work week. The HREF family and the NMM6Km are still in good
agreement on very isolated, weak high-terrain/Mogollon Rim
showers/storms every afternoon and evening through Fri. These
storms would be high-based storms with dry lightning and gusty
outflow winds with little to no rainfall. The HRW FV3 may once
again be a slightly more bullish outlier favoring slightly better
coverage of storms E and near Phx.
Although the low will be in position to rotate small vort
disturbances across the area for a few days, it is still fairly
weak and unable to attract more pronounced mid level (and BL)
moisture, with the GEFs plume now showing PW spiking near 0.77"
late this week. In addition there are still no IVT moisture plumes
currently depicted in ensembles with this system.
For Sat the Clusters analysis favors the ridge axis to the north
flattening and shifting E with weak zonal troughing near the PAC
NW. There is also flattened lingering high pressure and weak flow
over the Desert SW along with dry conditions being favored.
Tuesday Clusters depict differing positions of a W coast to W US
trough with clusters 3 and 4 showing a slight potential for light
QPF for central and S-Cent AZ likely associated with isolated
showers and storms. There is slightly better confidence however
for lower temperature from Sun and early next week associated with
increasing low pressure from the W.
&&
.AVIATION...Updated at 0000Z.
South-Central Arizona including KPHX, KIWA, KSDL, and KDVT:
A weak upper low is centered near the Baja Spur. Just upstream is
a high amplitude ridge of high pressure with an axis near the West
Coast. There is just enough moisture and instability to have isolated
thunderstorms over east central AZ late this afternoon. As of this
writing, the nearest storms to metro Phoenix were near Globe and
producing westward moving outflow winds nearing the Gila/Pinal
border. Storms are not expected to survive over the lower deserts
and the outflow is anticipated to weaken substantially as it nears
far southeastern portions of metro Phoenix early this evening.
Confidence in a distinct wind shift at KIWA too low to reflect in
the TAF at this time. Even lower confidence in that occurring at
the other TAF sites. But, it bears watching. Otherwise, anticipate
typical warm season surface winds with upvalley/westerly
directions being favored this evening (occasional gusts 15-20kts)
before transitioning to downvalley/easterly directions (well
after 07Z for PHX). Upvalley/westerly directions resume
midday/early afternoon Wednesday. Anticipate isolated afternoon
storms over the higher terrain on Wednesday though perhaps with
a little less potential for outflows to reach the metro area.
As for sky cover, anticipate some minor amounts of debris cloud
tonight but otherwise, no significant cloudiness.
Southeast California/Southwest Arizona including KIPL and KBLH:
A weak upper low is centered near the Baja Spur. Just upstream is
a high amplitude ridge of high pressure with an axis near the West
Coast. The end result though will be only minor amounts of high
clouds and familiar warm season surface wind patterns with
some afternoon gustiness (20-25kts). For KIPL, there looks to be a
period tonight of south-southwest directions before resuming
southeasterly.
&&
.FIRE WEATHER...
Friday through Tuesday:
Isolated thunderstorms, mainly over the AZ higher terrain, could
drift into portions of Maricopa and Gila Counties, including the
Tonto NF Thursday-Friday. The main threats with any storms, even
distant ones, will be lightning and gusty outflow winds of 25-40
mph. Otherwise, the subtle moisture increase will not do much to
improve RH with afternoon values dropping into the 7-15% range and
overnight recoveries mostly in the 20-35% range. Outside of
outflows, winds will generally be light to occasionally moderate
and follow typical diurnal/terrain influences with afternoon
breeziness.
&&
.SPOTTER INFORMATION STATEMENT...
Spotters should follow standard reporting procedures.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...None.
CA...None.
&&
$$
DISCUSSION...Sawtelle
AVIATION...AJ
FIRE WEATHER...Sawtelle/AD
Area Forecast Discussion
National Weather Service Pueblo CO
329 PM MDT Tue Jun 1 2021
.SHORT TERM...(This evening through Wednesday)
Issued at 328 PM MDT Tue Jun 1 2021
Upper jet and wave digging southward on the back-side of central
plains trough were providing the lift for scattered thunderstorms
across the area this afternoon, as residual moisture due to a very
wet May remains in place over srn CO. Expect scattered storms to
persist into the evening hours, with HRRR suggesting a broken line
of stronger convection near the KS border after 00z. Low end severe
risk for wind/hail remains, especially far eastern plains where
heating and resultant instability look slightly better. Activity
fades after sunset, though some showers/weakening thunderstorms
could linger until midnight or slightly later over the far sern
corner of the plains, per the 18z NAM. Again a risk of patchy ground
fog early Wed morning as ground remains moist, though weak low level
nly winds may work against fog formation in some areas.
On Wed, upper jet and wave move east of the area as central U.S.
trough slides into the Midwest. Still some weak energy in n-nw flow
aloft, plus plenty of residual moisture in place, which should fuel
afternoon/evening storms over the mountains, though intensity may be
weaker given lack of strong forcing. Scattered pops for the
mountains, valleys and I-25 corridor look sufficient for now, as
storm motion will have a fairly minimal easterly component. Max
temps will warm back toward seasonal averages as heights and mid-
level temps rise, and some low 80s will make a return to the lower
Arkansas Valley by late afternoon.
.LONG TERM...(Wednesday night through Tuesday)
Issued at 328 PM MDT Tue Jun 1 2021
...A slow warming and drying trend for southeast Colorado...
Wednesday night-Friday night...Latest models continue to indicate
moderate northerly flow aloft across the region into Thursday, which
moderates through the day Friday, as a large upper high builds into
the Great Basin. With the recent precipitation, there will be enough
residual moisture in place to support scattered afternoon showers
and thunderstorms for areas over and near the higher terrain, with
the northerly flow aloft likely keeping storms from moving across
the eastern plains. The weakening flow aloft will also lead to a
lessening potential for severe weather, however, can`t totally rule
out a stronger storm or two producing small hail, gusty outflow
winds, and locally heavy rainfall. This will also lead to the
potential for localized flash flooding, if one of these stronger
storms developed or moved across the more recent scars of the
Decker, Hayden Pass, Junkins or Spring burns. As for temperatures,
models support a warm summer time feel by Friday, with highs warming
into the 80s to lower 90s across the lower elevations, and mainly in
the 60s and 70s across the higher terrain. Overnight lows also look
to be more seasonal, with readings mainly in the 50s across the
plains, and in the 30s and 40s across the higher terrain.
Saturday-Sunday...Latest models agree the upper ridge flattens
across the Central Rockies as eastern Pacific energy translates
across the Northern Tier of States. While models agree on this, the
latest GFS continues to be a tad further south with the Northern
Tier passing system, with said energy helping to increase showers
and storm coverage across the area through the weekend. The latest
ECMWF and the Canadian runs, to a lesser extent, are a tad further
north with the energy, and do not indicate as much of an increase in
storm coverage. With that said, have stayed with current NBM pops,
which brings isolated to scattered pops to areas over and near the
higher terrain on Saturday and Sunday afternoon, with isolated pops
spreading across the far southeast plains on Sunday afternoon and
evening. Again, with only weak flow aloft, severe storm potential
looks to be limited. Temperatures through the weekend look to be at
at above seasonal levels, in the mid 80s to mid 90s across the lower
elevations, and mainly in the 60s and 70s across the higher terrain.
Monday-Tuesday...Increasing southwest flow aloft remains progged
across the region into early next weekend, as a broad upper trough
is progged to dig across the West Coast and into the Great Basin.
Models also continue to differ on how much embedded energy will move
across the Rockies, with the GFS and Canadian models more aggressive
with the embedded energy than the latest ECMWF. Again, stayed with
the blended model solution, which keeps isolated to scattered
afternoon and evening pops, greatest over the higher terrain, along
with temperatures at and above seasonal levels.
&&
.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 328 PM MDT Tue Jun 1 2021
Prevailing conditions will stay VFR, with a vcts possible until
until 00z-02z at all terminals as an upper level wave drops south
through the state. Main risk from storms will be gusty and erratic
outflow winds, though a brief period of MVFR cigs and vis will be
possible with the stronger storms. Could again see some areas of fog
Wed morning at all terminals, but will wait and evaluate today`s
rainfall before inserting a mention in any forecast. On Wed, still a
risk of tsra over the mountains in the afternoon, though chance of
storms holding together long enough to reach the terminals looks
low.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...PETERSEN
LONG TERM...MW
AVIATION...PETERSEN