Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 06/05/20
Area Forecast Discussion
National Weather Service La Crosse WI
647 PM CDT Thu Jun 4 2020
.SHORT TERM...(This evening through Friday)
Issued at 145 PM CDT Thu Jun 4 2020
Early afternoon water vapor imagery showed a weak upper wave moving
into western MN/IA. Isolated storms were already developing along
a weakly convergent boundary/moisture gradient just south of the
area across central IA. Expect MLCAPE to increase to 1000-1500
J/kg this afternoon into northeast Iowa along with modest deep
layer shear up to 25 kts. The combination of the approaching wave
with weak low-level convergence/increasing southerly flow and an
eroding cap will result in scattered storm development during the
mid/late afternoon hours across northeast IA, with storms shifting
eastward through the evening. The modest CAPE/shear profiles
would support fairly disorganized convection, but the stronger
cores could produce some hail and strong wind gusts, given the
relatively dry, deep subcloud layer. Could not rule out a severe
storm or two, but expect predominantly sub-severe storms.
Additional storms may develop from the northwest later tonight into
early Friday in association with another shortwave trough passing to
the north and surface front, although confidence in
evolution/degree of organization of these storms is on the lower
side. Deep layer shear will increase to 40-50 kts during this time
with MUCAPE remaining up to around 1000-1500 J/kg, especially
across the south half of the area. As a result, any of these
storms could pose a hail threat, while the wind threat would
depend on the degree of storm organization. Lingering
showers/storms will end Friday morning as drier air works south
behind the front with high pressure settling in.
.LONG TERM...(Friday night through Thursday)
Issued at 145 PM CDT Thu Jun 4 2020
Surface through mid-level ridging will build across the area this
weekend with mainly dry conditions and highs in the 70s and 80s.
Will have to watch for any convection firing out to the west trying
to sneak into the area from the west Saturday night into Sunday as a
stronger low-level jet/warm advection focuses into MN, but the
higher chances will likely be farther north and west.
As the thermal ridge axis tries to expand into the area from the
west on Monday ahead of a mid-level trough over the Rockies and
approaching front across the northern plains, hot and and more humid
temps look to make a return. 925 mb temps may climb into the 24-27C
range with NAEFS guidance also pegging anomalous warmth at 850.
Expect much of the area to approach or exceed 90 on Monday.
For mid-week, the mid-level trough to the west will translate east
across the area dragging a cold front through. Confidence is
pretty low on how this trough may interact with the remnants of
Cristobal that some model guidance lifts north towards the Great
Lakes. Chances for showers/storms will likely increase Tues,
possibly into Wed with the trough and a rich plume of moisture
advecting northward, before cooler, more seasonable air arrives
behind the front later in the week.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 645 PM CDT Thu Jun 4 2020
Isolated showers and thunderstorms will be near KRST/KLSE this
evening, however additional thunderstorms are expected to move in
later tonight. There is some isolated thunder with the storm to
the west of KRST and will mention thunder more in the 05-10Z time
frame at both sites and some variable/gusty winds near storms.
The RAP is hinting at some MVFR ceilings at KLSE around 07Z-11Z
with the thunderstorms. Outside of storms...light and variable
winds become northwest after 12Z and increase 10 to 15kts.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
IA...None.
&&
$$
SHORT TERM...JM
LONG TERM...JM
AVIATION...Zapotocny
Area Forecast Discussion
National Weather Service Bismarck ND
943 PM CDT Thu Jun 4 2020
.UPDATE...
Issued at 940 PM CDT Thu Jun 4 2020
A few showers continue across east central North Dakota, perhaps
supported by the nose of an h300 110kt jet exit region. CAM models
do not support these showers maintaining themselves after midnight
CDT. Otherwise the showers have already cleared out of southeast
North Dakota and skies are clear or clearing.
UPDATE Issued at 645 PM CDT Thu Jun 4 2020
Fast moving mid level ripple moving through the northern plains
this evening. Most of the convection is now moving through the
James River valley, but with a few cells are popping across
southwest North Dakota in an uncapped area. We expect these to
rapidly move east and eventually diminish after sunset. Current
forecast looks ok.
&&
.SHORT TERM...(This evening through Friday)
Issued at 316 PM CDT Thu Jun 4 2020
Shower and thunderstorm activity this afternoon will wane this
evening, leading to a cool night and then a pleasant Friday.
GOES-East low-level moisture channel imagery reveals an area of
drying moving into southwestern ND and northwestern SD as of 19
UTC, with recent intensifying convection and related cloud-top
cooling centered on Bowman County on the drying`s leading edge.
This represents the eastward movement of a shortwave trough and
related intensifying jet dynamics aloft that appear on track to
bring a round of showers and thunderstorms to the southwest and
south central this afternoon and early evening. Observational
trends are supportive of the good agreement seen in the 12 UTC
HREF members and HRRR cycles through its 18 UTC cycle for this
area of convection to move eastward through 00 UTC, especially
along and south of I-94. Strong westerly flow aloft along with
persistent southerly surface winds in southern ND are creating
0-6-km bulk shear on the order of 50 kt, as confirmed by recent
KBIS VWP data. Instability is marginal for organized storms, but
sufficient for a strong storm or two, especially along the ND/SD
border from Grant/Sioux Counties east to Emmons, McIntosh, and
Dickey Counties, where lower and middle 50s F surface dewpoints
may reach ahead of the convection in favor of local MLCAPE around
1000 J/kg in the mid to late afternoon. Still, the overall severe
risk is marginal as supported by recent cycles of an internal,
HRRR-environment-driven statistical model which maintains higher
probabilities of more intense storms in SD.
Otherwise, convection will exit the area this evening concurrent
with the middle and upper-level shortwave. Surface ridging will
favor light winds and clear skies so we leaned toward the cooler,
MOS-weighted guidance for lows, calling for them to be around 40
F in favored cool spots south and west of the Missouri River. On
Friday, heights aloft will rise while flow turns southeasterly,
with NBM-based highs forecast in the middle and upper 70s F. The
background synoptic-scale flow favors a dry forecast, which we are
carrying, despite hints in some CAMs for elevated light showers in
the developing warm air advection pattern during the day.
.LONG TERM...(Friday night through Thursday)
Issued at 316 PM CDT Thu Jun 4 2020
Strong southeast winds Saturday and severe storm risk through the
weekend are the highlights of the long term.
Global deterministic and ensemble guidance continues to converge
on several details of potential for impactful weekend weather due
to a deepening middle- and upper-level trough over the Rockies.
Downstream south-southwest flow aloft and lee cyclogenesis will
foster a favorable environment for convection over the Northern
Plains. Initially, a low- and midlevel warm frontal zone should
become established from central MT into SD late Friday night and
Saturday along with an intensifying low-level jet. Some guidance
continues to suggest elevated convection with a non-zero risk of
hail may develop as soon as late Friday night or more likely on
Saturday morning within this initial regime of theta-e advection
aloft. However, greater confidence in potential storms exists on
Saturday night as a stronger shortwave trough is forecast to lift
northward through the region. The mass-field responses to passage
of that impulse will likely yield clusters of northward-moving
storms in an environment potentially characterized by large CAPE
for elevated parcels and strong shear from late Saturday afternoon
into Saturday night. NBM-based PoPs reflect 60-80 percent chances
of storms centered on Saturday evening with ensemble QPF guidance
offering support for this scenario. However, it`s critical to note
that forecast soundings depict a notable warm layer aloft north of
the surface warm front, i.e., across ND, and the degree of MUCAPE
and importantly MUCIN will be very sensitive to the magnitude and
depth of low- and midlevel moistening. The deterministic ECMWF is
less-robust with Saturday afternoon and evening convection, with
a slightly-further west trajectory of the shortwave, and some NAM
and GFS soundings suggest capping could prevail, so there is some
uncertainty in the coverage of storms.
Regardless, mean southeast boundary layer winds of 30 kt Saturday
suggest a Wind Advisory could be required, and forecast soundings
suggest potential for mixing up to 40-45 kt winds depending on
how much convection and cloud cover occurs during the day to
temper low-level warming and related mixing.
By Sunday, guidance strongly agrees that the surface warm frontal
zone will lift northward, allowing for an influx of richer low-
level moisture, especially in central and eastern ND. GEFS-based
CIPS analog regression-based severe probabilities are high Sunday
afternoon and evening, and the potential parameter space as noted
by the GFS and NAM simulations suggests the possibility of MLCAPE
of 3000-4000 J/kg with deep-layer shear on the order of 50-70 kt.
That suggests potential for significant-severe hazards including
very large hail, and the synoptic-scale pattern suggests potential
of damaging winds and a tornado risk, too, all of which is borne
out in the CIPS analog severe hazard probabilities. All of that
said, the ECMWF is less robust with moisture return Sunday, and
all guidance suggests midlevel capping is likely within the warm
sector, so the risk Sunday will likely be highly conditional in
nature and so caution is advised in focusing on the parameter
space alone at this time range. Depending on capping and mesocale
forcing trends, a wide spectrum of storm coverage is possible.
During the early and middle part of next week, the upper-level
trough is forecast to lift into Canada, which eventually will
lead to a cooler, more stable, and drier regime. The timing of the
transition to that pattern is an area of uncertainty, though, as
the GEFS mean suggests it could be slower than the deterministic
GFS and ECMWF suggest. In that regard, GEFS-based CIPS analog
severe guidance suggests a storm threat may linger in central ND
on Monday.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 645 PM CDT Thu Jun 4 2020
VFR flying conditions are forecast through Friday.
At 6 PM CDT numerous showers and scattered thunderstorms were
moving east through the James River Valley. Scattered showers and
isolated thunderstorms were in the Dickinson Vicinity. We expect
all convection to end after 10 PM CDT tonight.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...WAA
SHORT TERM...CJS
LONG TERM...CJS
AVIATION...WAA
Area Forecast Discussion
National Weather Service Caribou ME
910 PM EDT Thu Jun 4 2020
.SYNOPSIS...
Weak high pressure will pass over the area overnight. A cold
front approaches from the northwest Friday, then slowly pushes
south through the state Friday night and Saturday. Canadian high
pressure then builds in for the remainder of the weekend into
Tuesday.
&&
.NEAR TERM /THROUGH FRIDAY/...
9:10 pm update: The last of the isolated showers have ended
across the Saint John Valley. Satellite pictures and
observations indicate a clear to partly cloudy across the FA. It
will remain tranquil overnight and not as cool as last night. In
fact, in most areas lows will be a few degrees above average
for early June. Updated with the past few hours of observed data
and for the expected weather conditions the remainder of the
night. Overall, the ongoing forecast was in fine shape and
changes were very minor.
Previous discussion:
Clouds and any isolated showers in the N will gradually
diminish with loss of daytime heating, giving way to mostly
clear skies and light winds. Overnight lows will range from the
mid 40s across the cooler northwest valleys to mid 50s across
Downeast Maine.
A weak warm front will approach the area on Friday with moisture
advection leading to increasing surface dew points into the 50s
to low 60s. An isolated shower or thunderstorm will be possible
with help from terrain processes from just north of Bangor
through southern and central Aroostook County, mainly during the
late afternoon and early evening. There is still some
uncertainty with how much instability will be available, with
the typically more moist NAM and 18z HRRR on the higher end and
global model guidance showing a swath of MUCAPE around 500 to
1,000 j/kg across the aforementioned areas. If the higher
instability values come to fruition, then an isolated storm
could be on the stronger side given ample shear in place. Highs
in the 80s are expected across most of the forecast area
excluding the coast, where onshore flow will transport cooler
maritime air overhead.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
Weak frontal boundary slides to the coast Friday night and
appears to stall along the coast. Some leftover showers will be
around Friday evening especially across the downeast areas
w/some fog developing. Further n, some partial clearing is
expected. This is shown by the 12Z NBM/NAM and even the GFS. The
12Z run of the ECMWF was somewhat similar w/the partial
clearing as well. Then the challenge comes in later Friday night
into Saturday as the cold front to the n drop s. The latest
suite of the 12Z guidance including the NAM/ECMWF/GFS and
Canadian GEM show a low pres wave developing on the front later
Friday night and lifting up across eastern Maine on Saturday.
The ECMWF and Canadian are the most robust w/this low bringing a
decent dose of rainfall across the northern and western areas
in Saturday morning. The NAM and GFS are weaker w/the low and
not as heavy w/the rainfall keeping the bulk of the rainfall w
and n of the border. There does appear to be enough instability
associated w/the system to bring some tstms across northern
areas into Saturday morning and then cooler air moving in behind
the front shuts down the convection.
The focus shifts further s as the front sags s. Portions of the
Maine Central Highlands down into the interior Downeast
including the Bangor region could see some breaks in the marine
layer as it looks like this layer shifts further s and e. This
would lead to some heating and destabilization allowing for
tstms. Lapse rates of 6.5 c/km across the Maine Central
Highlands into the Bangor region are noted on the NAM and GFS
providing good updraft potential. MUCAPE of 1000 joules are
possible w/SWI closing in around -1 to -2 would be enough to
support elevated instability. This gives enough credence to keep
tstms in forecast as was noted by the midnight crew. Tstm
chances for the coast should be weakened by the marine layer.
Not enough confidence attm to add any enhanced wording due to
the potential that if the ECMWF continues to follows it trend of
keeping clouds and precip around longer, then instability gets
shut down. Just something to note that does merit attention, is
the shear that looks to be increasing on Saturday. If this
continues to be the case, then the increased threat for strong
storms could be there. Decided to spit the difference for daytime
temps and went a bit cooler than what previously forecast especially
across the northern areas w/the cooler air arriving in earlier.
Definitely much cooler Saturday night into Sunday as the
Canadian airmass settles in. The upper trof will be moving
across the region Saturday night into Sunday w/the slight chance
for some showers. Some tstms could be ongoing across the
Downeast region into Saturday evening as the front moves to the
coast. Temps will be running below normal for June.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
Canadian high pressure is expected to build in across the region
early next week with cooler temps ongoing into Tuesday. Monday
night could be a chilly night w/clear skies and winds. Cannot
rule out patchy frost over the nw areas by daybreak Tuesday.
Temps look like they will moderate starting Wednesday and
continuing into Thursday w/high pres to our south and a s wind
bringing in warmer air.
&&
.AVIATION /01Z FRIDAY THROUGH TUESDAY/...
NEAR TERM: VFR. Light wind the remainder of tonight. SSW wind
with gusts ranging from around 15 kts across the south to 25 kts
at FVE during the day Friday. There is a slight chance of IFR
CIGs at KBHB with SHRA and a slight chance of -TSRA from
approximately GNR into MLT/HUL/PQI/CAR by mid to late afternoon.
SHORT TERM:
Fri night-Sat...VFR early w/MVFR to IFR for KBGR and KBHB by
later in the evening into the overnight. Northern terminals will
stay VFR into late evening and then MVFR to IFR overnight into
Saturday morning w/some showers and possible tstms. Another
round of shra and tsra Sat afternoon with MVFR and localized IFR
conditions expected. SSW 5-10kts becoming WNW and gusty Sat
afternoon.
Sat night into Sun...MVFR becoming VFR Sat night w/some leftover
showers. Could be seeing periods of MVFR cigs across the
northern terminals on Sun w/cold air aloft. NW winds 5-15 kts.
Sun night-Mon...VFR all terminals. NW 5-10ks w/winds increasing
to 10-15 kts on Mon.
Mon night into Tue...Continued VFR for all terminals w/light and
variable winds.
&&
.MARINE...
NEAR TERM: A Small Craft Advisory will continue across the outer
waters through early Friday afternoon due to a southerly swell
with a period around 11 seconds and wave heights around 5 feet.
Seas diminish slightly to around 4 feet over the outer waters
later Friday afternoon.
SHORT TERM: SCA for seas continues Fri night right into Sat
night in a long period s swell over the outer waters. Vsbys
will be reduced below 1 NM in fog and light rain Fri night into
Sat morning. A cold front is forecast to pass over the waters
Sat evening clearing things out. SSW winds 10-15 kts becoming
WNW Sat night into Sun.
Sun night into Mon...NW winds 10-15 kts w/seas 3-4 ft.
Mon night into Tue...WNW winds 10 kt w/seas dropping back to
2-3 ft.
&&
.TIDES/COASTAL FLOODING...
High astronomical tides are expected late this evening and
again late Friday evening. A long period s swell of 5 to 6 feet
may cause minor overwash tonight and possibly on Friday night.
No storm surge is expected to enhance the tide Thursday night,
and especially the Friday night high tide. A coastal hazard
message was issued for around the time of high tide late this
evening.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...None.
MARINE...Small Craft Advisory until 2 PM EDT Friday for ANZ050-051.
&&
$$
Near Term...CB/MStrauser
Short Term...Hewitt
Long Term...Hewitt
Aviation...CB/MStrauser/Hewitt
Marine...CB/MStrauser/Hewitt
Tides/Coastal Flooding...CB
Area Forecast Discussion
National Weather Service Dodge City KS
550 PM CDT Thu Jun 4 2020
...Updated aviation section...
.SHORT TERM...(This evening through Friday)
Issued at 1206 PM CDT Thu Jun 4 2020
At the time of this discussion a 700 mb shortwave with some
instability has produced some isolated storms between Garden City
and Ulysses. These storms should continue to move east and
gradually diminish through the early afternoon.
Later this afternoon and tonight another shortwave out of eastern
Colorado will move into southwest Kansas and the Oklahoma-Texas
panhandles. Isolated storms are expected to develop along a
dryline around Springfield, Colorado and move eastward into
southwest Kansas. Another area of storms is expected to develop
west of Goodland which may cross into areas north of Garden City
towards sunset this evening. With CAPE values in the 1500-2000
range and steep low level lapse rates...both hail and downburst
winds will be the main threats. Once you get east of highway 283
the storms should fizzle out as the CAP will be much stronger.
For Friday the upper level ridge in the southwest slowly starts
moving towards the central plains...another hot day is expected
with highs nearing 100. A residual boundary is forecast to lift
into southwest Kansas during the day and stall out from Elkhart to
Hays. The 12Z HRRR model is forecasting some afternoon convection
to break out along the boundary...and a few other CAM models are
starting to hint at this as well. With the hot temperatures
reaching the convective temperature shouldn`t be a problem so
there is the possibility of more isolated to scattered storms
possible along the boundary in our northern zones.
.LONG TERM...(Friday night through Thursday)
Issued at 146 PM CDT Thu Jun 4 2020
Hot and windy conditions for the the weekend into Monday as the
upper level ridge crosses into the central plains. Expect highs in
the mid-upper 90s with winds 20-35 mph. By Tuesday a trough and a
good push of cooler air moves into Kansas which should drop highs
back into the mid-upper 80s. Storm chances at this point look to
stay mainly from the I-70 corridor on north. This front should
keep much of the tropical storm moisture which is expected to move
into eastern Oklahoma and Kansas by Tuesday afternoon.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 549 PM CDT Thu Jun 4 2020
A few isolated thunderstorms will be possible around the GCK
terminal this evening. However, VFR conditions will prevail
through tomorrow. Winds will generally be less than 12 knots
through tomorrow morning.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 65 98 70 98 / 20 20 20 0
GCK 63 98 69 98 / 20 20 10 0
EHA 64 101 70 98 / 20 0 0 0
LBL 64 100 69 98 / 20 0 0 0
HYS 66 96 70 98 / 20 20 10 0
P28 68 99 72 98 / 20 0 20 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Tatro
LONG TERM...Tatro
AVIATION...Hovorka_42
Area Forecast Discussion
National Weather Service Des Moines IA
1044 PM CDT Thu Jun 4 2020
.DISCUSSION.../Tonight through Thursday/
Issued at 251 PM CDT Thu Jun 4 2020
Summary...
The name of the game today/tonight will be scattered non-severe
storms this afternoon/evening, followed by a line or broken line of
storms streaming in from the northwest overnight. After that, warm
to hot and humid remains through the weekend and to start next week
before cooling back towards normal by the middle of the week.
Potential remains too for parts/remnants of Tropical Storm Cristobal
influencing Iowa Tuesday.
Today through Friday Morning...
A couple of concerns exist through this time frame, including
scattered storms continuing across portions of northern Iowa and the
potential for a line of stronger storms overnight moving in form the
Dakotas.
Currently, satellite nicely depicts the cumulus field that began to
blossom around/after 16z this morning. A few scattered storms began
around 17z and continue currently, primarily along Highway 20 where
there is also a weak surface/low level convergence boundary and
concurrent with the approach/passage of a weak shortwave aloft. With
the underwhelming wind profiles, storms have primarily been
relegated to short lives of moderate to heavy rainfall and small
hail potential. An isolated stronger updraft capable of marginally
severe hail will be possible, but should continue to follow the
up/down nature with inability to organize.
Later tonight, storms beginning to fire up in W South Dakota and SW
North Dakota will grow upscale and take a likely SE/ESE turn, riding
along the MUCAPE gradient. Some uncertainty remains in the exact
geographic extent, ranging from a long linear structure to a broken
line of sorts. Model trends today have typically trended toward the
latter, likely due to the relatively dry air situated just NW of the
air in the low-mid levels. That said, with better moisture situated
within central Iowa and forecast to remain, if not slowly increase,
overnight there is concern for growth as it enters the forecast
area. Should that come to fruition, the main concerns will revolve
around strong/damaging winds and hail (especially any storms able to
organize within increasing shear profiles). A non-zero tornado
threat will remain based on shear vector orientation (though a small-
ish margin with 0-3km around 30-40 kts), and will be for QLCS
development as opposed to any supercells (which would be more
elevated in nature). Have tended to lean towards the HRRR suite
throughout the day given its relatively well handling of the current
situation. With some lingering uncertainty in spatial extent and
evolution, the SPC Slight Risk across much of the area is more than
reasonable.
Friday Afternoon through Thursday...
Warm and at times humid conditions will remain through the weekend
and to start the week. A reprieve from the humidity will be seen
Friday and Saturday as drier air settles in. The warmth though will
predominantly continue, especially Sunday and Monday as upper
level/thermal ridging slides east. Monday continues to look like
another day in the low 90s with 850mb temps in the low 20s deg C.
The ridging will quickly be ushered away as the western trough
begins to kick out Tuesday. As it does so, the next good opportunity
for widespread rainfall will accompany it Tuesday, including the
continued opportunity for at least some remnants of Tropical Storm
Cristobal (mainly moisture) as well. The rest of the week then looks
to return to near-normal conditions in mid 70s to low 80s and
comfortable dew points.
&&
.AVIATION.../For the 06Z TAFS through 06Z Friday night/
Issued at 1044 PM CDT Thu Jun 4 2020
Scattered thunderstorms have managed to sustain themselves along and
north of the highway 20 corridor, impacting KFOD, and KALO mainly.
Storms in this area will continue and any that pass over TAF sites
will be capable of large hail and strong/damaging wind. Overnight,
more widespread thundstorms will push across the state with a
widespread threat for large hail and damaging wind. VFR conditions
are mainly expected but in storms, MVFR cigs/vsbys will be possible,
along with strong wind. Storms pass east in the morning with VFR
conditions for the remainder of the period.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
DISCUSSION...Curtis
AVIATION...FAB
AREA FORECAST DISCUSSION
National Weather Service Kansas City/Pleasant Hill MO
1002 PM CDT Thu Jun 4 2020
.Update...
Issued at 1002 PM CDT THU JUN 4 2020
Have updated the forecast to bring in a chance for storms
overnight. Pockets of thunderstorms have been trying to organize
as they track across Nebraska. The latest HRRR and ARW have
initialized this convection very well and track it to the east-
southeast into the area after 06Z. Given this, have increased PoPs
and QPF to account for the possibility of another MCS moving into
the area overnight. As for potential for strong to severe weather,
instability is not as great as it was yesterday but we should
still have a couple thousand J/kg of CAPE available for storms to
work with. There is also stronger northwesterly flow aloft and
this is leading stronger shear. Given the CAPE/shear combination,
the potential for severe weather, with damaging winds the main
threat, looks like a possibility again tonight.
&&
.Discussion...
Issued at 303 PM CDT THU JUN 4 2020
A rather flat pattern is seen prevailing on satellite imagery across
the center of the Nation today, with the shortwave trough that
helped bring our early morning severe weather now seen zipping east
into the Ohio River Valley. However, the shortwave trough we will
need to pay attention to now, for tonight`s weather, is noted moving
east across the southern plains of Canada, dragging a cold front
south across the northern Plains. Currently, the front has pushed
into northwest Iowa, stretching back into central Nebraska.
Early Friday morning, a nocturnal jet, associated with the Canadian
shortwave trough, looks to kick off a MCS across Nebraska as it
interacts with the frontal boundary to our north. The storms will
then sweep east-southeast, possibly across parts of far northern
Missouri around to after sunrise Friday morning. Both operational
and CAM models are in decent agreement on the timing and placement,
so confidence is rather high at this time. What storms develop are
expected to stay north of Highway 36, as warmer temperatures aloft
look to cap us off areas farther south Friday morning. However, what
storms there are will have some instability and shear to work with
early in the morning, which may bring a threat of hail or wind,
along with torrential rain across far northern Missouri Friday
morning.
Once Friday mornings activity moves through we will then have to
watch for any left over boundary that the convective system leaves
behind. Currently, models indicate that any left over boundary in
northern or central Missouri will likely be reinforced by the cold
front currently in Nebraska and Iowa. There is some indication that
that boundary could reactivity that evening, or late that night/
early Saturday morning, but confidence on timing and placement are
iffy at best given that it depends on the antecedent storms Friday
morning.
Otherwise, expect temperatures to remain hot and humid, with heat
indicies Friday likely to top out around 100 degrees with absolute
temperatures in the low 90s. Temperatures will moderate a little
through the weekend as the backdoor cold front settles into the
region, though temperatures will still be in the 80s to low 90s.
&&
.Aviation...(For the 00Z TAFS through 00Z Friday Evening)
Issued at 622 PM CDT THU JUN 4 2020
There are a couple of periods of time for more thunderstorm
potential at the terminals. First overnight tonight with storms
that could organize across Nebraska and move into the area.
Second, in the heat and humidity late tomorrow afternoon. Both of
these are low confidence at this time so for now have kept mention
of them out of the forecast. For the overnight chance, the
reservoir of potential instability is not nearly as high over the
area as it was yesterday. And the greatest instability is over
central to northern KS. For tomorrow`s chance, potential
instability becomes extreme again but may be inhibited by a cap.
Models vary in whether that cap breaks and with only a weak
boundary floating around and no evident upper-level support have a
hard time mentioning anything at this point.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
Update...CDB
Discussion...Cutter
Aviation...CDB
AREA FORECAST DISCUSSION
National Weather Service Hastings NE
611 PM CDT Thu Jun 4 2020
...Aviation Update...
.UPDATE...
Issued at 450 PM CDT Thu Jun 4 2020
Increased/expanded PoPs through tonight to more closely match the
latest runs of the HRRR and other short term guidance. These
models show thunderstorms moving west to east through the forecast
area, mainly from 7pm to 1am tonight.
&&
.SHORT TERM...(This evening through Friday night)
Issued at 324 PM CDT Thu Jun 4 2020
A mid-level embedded perturbation will help touch off some
thunderstorms this afternoon near the cold front in South Dakota,
and along a trough over Nebraska/Kansas this afternoon. Better
support for severe weather with potential northern MCS to develop,
keeping this mostly if not entirely out of our CWA where stronger
updrafts will be supported.
Hi-res models indicate the potential for convection to creep into
the CWA this evening into the overnight, but nowhere near the
support for severe weather as we had last night.
Went closer to HRRR/HRRREXP for highs Friday, based on recent model
performance statistics. Cold front will likely stall in the southern
CWA or just south for Friday, but best moisture hold on more to the
east. Our far east/southeast may be able to get in on some
convection for the evening, but not much to hang our hat on, and
generally looks dry for us Friday/Friday night.
.LONG TERM...(Saturday through Thursday)
Issued at 324 PM CDT Thu Jun 4 2020
The story this weekend is HOT and WINDY! Saturday and Sunday look
very similar with highs above normal in the 90s and gusty winds.
Deep ridging will be in place over much of the central CONUS along
with an upper level trof approaching from the west. Expecting a
rather tight sfc pressure gradient on Saturday and Sunday ahead of
the trof. This will lead to sustained southerly sfc winds around 20-
30 kts. Model soundings also suggest the potential for mixing down
gusts to the sfc of around 40 kts. There could be a brief shot of
precip Saturday night for far western portions of the CWA, but don`t
currently have a lot of confidence in this.
Sunday night a minor short wave along the leading edge of the trof
forms a cold front across the NE panhandle. As Monday comes around
this front will start to push southeast across western NE. Showers
and thunderstorms are expected to develop along the front late in
the day on Monday. These storms are expected to impact the CWA
overnight on Monday and into Tuesday as the front crosses through
from the NW to the SE. Behind the front we can expect cooler, more
seasonal temperatures for Tuesday, Wednesday, and Thursday.
&&
.AVIATION...(For the 00Z KGRI/KEAR TAFS through 00Z Saturday)
Issued at 605 PM CDT Thu Jun 4 2020
Scattered thunderstorms expected to move from west to east in the
vicinity of the terminals this evening. The main threat to the
terminals will be brief gusty winds to around 60 MPH.
After the storms move through, skies will clear and winds will
shift from the southwest to northwest overnight, and eventually to
the east on Friday.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE...Mangels
SHORT TERM...Heinlein
LONG TERM...Shawkey
AVIATION...Mangels
Area Forecast Discussion
National Weather Service Green Bay WI
1038 PM CDT Thu Jun 4 2020
Updated aviation portion for 06Z TAF issuance
.SHORT TERM...Tonight and Friday
Issued at 332 PM CDT Thu Jun 4 2020
The latest RAP analysis and satellite/radar imagery show shortwave
energy slowly moving across south-central Canada, and pushing a
weak cold front across northeast Minnesota to southern South
Dakota early this afternoon. Strong surface-based instability has
been confined to areas from southeast Minnesota to northern
Illinois so far today. Only minor instability has developed along
the front, as evident by little convective cloudiness along the
boundary. As result, high resolution guidance has backed off on
shower and thunderstorm development along the front late this
afternoon into this evening. As shortwave energy draws closer to
the region tonight, shower and thunderstorm chances are the main
forecast concerns.
Tonight...Details surrounding shower and thunderstorm
timing/coverage remain rather elusive. Because instability along
the weak is forecast to remain meager, removed the small chance of
showers/thunderstorms along the boundary during the evening. But
as shortwave energy draws closer to the region from the northwest,
southwest winds are expected to return over the stalled boundary,
which will be positioned over central to northeast WI by late this
evening. Models show elevated instability (600 to 1000 j/kg) returning
northward into central to east-central WI after midnight at the
same time as moisture convergence increases aloft. This points
towards the potential for a cluster of showers/storms to impact
the region and guidance points towards an arrival from the west
after 08-09z. This is about few hours slower than the previous
forecast. Without a strong low level jet or well defined
shortwave, severe weather chances look rather low. Suppose the
strongest storms could produce wind gusts to 40 mph and small
hail. Temps will be a little warmer tonight as clouds increase
late. Lows ranging from the middle 50s to middle 60s.
Friday...Showers and thunderstorms will continue across the region
during most of the morning. Elevated instability doesn`t make much
more progress northeast, so believe the severe weather threat will
remain low. Most of the showers/storms will be exiting the
lakeshore by early to mid-afternoon, before clearing occurs from
west to east. Guidance has a wide range of possibilities for max
temps tomorrow afternoon. Generally stayed close to the national
model blend, but if clouds/rain continues to trend slower, temps
may need to be dropped further.
.LONG TERM...Friday Night Through Thursday
Issued at 332 PM CDT Thu Jun 4 2020
The main highlights from this forecast period are the dry conditions
and slightly cooler temperatures this weekend, and the potential for
the remnants of the tropical system Cristobal to impact the region
during the middle of next week.
Friday night through Monday...Surface high pressure will move into
the region as the upper-level pattern transitions to a northwest
flow ahead of a ridge. This will bring "cooler" air to the forecast
area. High temperatures on Saturday and Sunday will be in the upper
60s to middle 70s. Dry conditions are also anticipated from Friday
night through early Sunday. Although the main axis for the upper-
level ridge will be over the Upper Mississippi Valley on Sunday,
model guidance is showing signs of light precipitation moving into
northern Wisconsin. The upper-level ridge will continue to dominate
over Wisconsin through Monday allowing high temperatures to rise
back to the 80s.
Rest of the extended...The upper-level pattern will transition to a
southwest flow into Tuesday. Models are having phasing problems
beyond this time period due to the tropical system Cristobal.
Generally, there are two solutions, (1) Cristobal phases with the
southwest flow and rides north towards the Upper Mississippi Valley,
which the ECMWF and Canadian show, or (2) Cristobal stays across the
southeastern U.S., which the GFS shows. Regardless of Cristobal`s
track, the forecast area is likely to see heavy rainfall and
thunderstorms sometime between Tuesday and Wednesday.
&&
.AVIATION...for 06Z TAF Issuance
Issued at 1017 PM CDT Thu Jun 4 2020
Showers and scattered thunderstorms are expected to overspread
the forecast area after midnight into Friday morning, as a cold
front and associated upper level disturbance moves through the
western Great Lakes region. This complex appears to be headed this
way from western Minnesota. Brief MVFR vsbys and gusty winds may
accompany any heavier downpours, but most of the region will have
VFR conditions. Any storms will move out later Friday morning and
into the early afternoon with VFR conditions and quiet weather
expected Friday afternoon and evening.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......Hykin
AVIATION.......Kurimski
Area Forecast Discussion
National Weather Service Jackson MS
911 PM CDT Thu Jun 4 2020
.UPDATE...
Updated for evening discussion.
&&
.DISCUSSION...
Only minor changes were made to the ongoing forecast. Trimmed pops
back across the majority of the CWA, but kept a sliver of slight
chance pops across the Golden Triangle, as a small cluster of
thunderstorms across Union County MS could brush across the said
area later tonight. Otherwise, benign weather overnight with
chances of storms returning to the region Friday
morning/afternoon. Some of the precip activity tomorrow could
pose a threat for hail and gusty winds. /29/
Prior discussion below:
Rest of this evening through Friday...
Rest of this evening: Overall convection has been on the tame
side with some subsidence from a MCV/departing shortwave. Due to
that, left the HWO clear for today but will let the graphic
eventually fall off probably early this evening.
Tonight: Expect any rain & storm chances to clear out into the
early evening as diurnal heating decreases after sunset. Some
residual cloud cover is possible overnight with some lower
clouds possible across the Pine Belt. Lows will generally be above
normal in the lower 70s in the Delta to upper 60s east of
Interstate 55.
Friday: By Friday morning, a lobe of some stronger shortwave
trough jet energy/vorticity will be diving through the Mid-South
& into the Appalachians. 700mb flow will gradually become more
northerly as this mid-level shortwave trough energy dives down.
Some rain & storm chances may move in just around daybreak &
spread to the west-southwest through the day. Model consensus of
GFS/Euro show nearly 6.5-7 degrees C. mid- level lapse rates,
vertical totals to nearly 26-29 degrees C. & north-northwesterly
low-level (i.e. 0-2 to 0-3km) bulk shear around 15kts+. In addition,
this environment favors nearly 4000 J/kg SBCAPE, -3 to -5 deg. C
Showalters/-8 to -10 deg C. lifted indices & 1000-1300+ J/kg DCAPE.
CAM guidance including the HRRR/ARW/NMM indicate a good MCS diving
down out of the Ozarks in Missouri & into our northwest Delta by mid-
afternoon or potentially a little later. There is good enough
consensus that if trends continue, a graphic/HWO update would likely
be needed in later updates. Main threats would be gusty winds & some
hail threat. One thing of note is the HRRR is showing some pretty
significant wind potential with this so something to watch closely.
Highs will warm above normal into the low 90s with somewhat less
mixing as today so heat indices could climb into the upper 90s to
near 100 degrees. That heat & humidity will only aid in organized
convective potential as well. /DC/
Tomorrow night through Thursday...
The forecast period starts off tomorrow night with a southern stream
closed mid/upper-level low moving onto the California Coast. This
low will quickly open into a shortwave trough as it phases with a
more amplified northern stream wave over the Pacific Northwest.
Mid/upper-level ridging over the Texas/Mexico border will also shift
northeast into the Middle Mississippi River Valley. Meanwhile, far
to our south, Tropical Depression Cristobal continues to meander
over inland portions of the Yucatan Peninsula. Cristobal will
finally begin to move north Saturday and is currently forecast to be
nearing the Louisiana Coast on Sunday. Considerable uncertainty
continues to plague the forecast heading into the weekend and early
next week, however. Upper ridging to our north will slow forward
motion temporarily until a weakness develops between the ridge and
the advancing northern stream wave emerging out of Inter-Mountain
West. This will eventually foster a west northwest storm motion, but
how far west remains yet to be seen. 12z suite of global guidance
has trended towards a slightly further west solution, which will
bear watching with future guidance to see if this trends persists.
Furthermore, Cristobal will struggle with dry air entrainment as
well as increasing vertical wind shear over the northern Gulf of
Mexico. As such, confidence remains low with respect to the
intensity forecast and inland extent of impactful wind gusts could
be greatly limited and mainly confined to coastal areas.
In terms of sensible weather, the majority of Saturday should remain
mostly dry with scattered showers starting to move into southern
portions of the area late Saturday afternoon into the evening.
Sunday through Tuesday will be the wettest period, but coverage of
rain and storms will be highly dependent on the eventual track of
Cristobal. A localized flooding threat may eventually materialize
owing to the potential for convergent bands of heavy rainfall that
could result in several inches of rain over a short duration.
However, this setup will be governed by mesoscale influences that
can`t be resolved at this timeframe so will continue to leave the
HWO/graphics clear for now.
By Wednesday, a cold front over the Great Plains will be pushing
towards the area in association with the potent northern stream
trough as it lifts into the Great Lakes region. The ECMWF solution
appears to handle this feature the best and lifts the remnants of
Cristobal out of the area with a drier airmass filtering in behind
the front. The GFS/CMC, on the other hand, stall the front to our
northwest and keep a warm and humid summer airmass in place with
diurnally driven showers and thunderstorms. Will keep this portion
of the long term forecast in line with model blends for now until
guidance comes into better agreement regarding the synoptic pattern
evolution. /TW/
&&
.AVIATION...
00Z TAF discussion:
Spatial extent of precipitation activity continued to diminish
across the area this evening, especially with the onset of sunset.
Have elected to maintain a VCSH across the northern terminals and
the southeastern terminals for an hour or so, due to
precipitation activity north and south of the aforementioned
terminals possibly sneaking in. Otherwise, overnight should be
relatively quiet with the exception of MVFR CIGS occurring at KPIB
and KHBG. Tomorrow late morning into the afternoon, the passage
of a shortwave trough will bring about the return of -TSRA. Some
of this activity could pose a threat for hail and gusty winds.
/29/
&&
.PRELIMINARY POINT TEMPS/POPS...
Jackson 71 91 72 91 / 9 44 8 26
Meridian 69 91 71 88 / 15 51 10 27
Vicksburg 72 92 75 93 / 6 30 8 25
Hattiesburg 69 90 71 87 / 8 48 7 36
Natchez 71 90 73 90 / 8 31 6 26
Greenville 73 92 75 93 / 13 31 11 16
Greenwood 72 92 74 93 / 16 40 14 18
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...None.
LA...None.
AR...None.
&&
$$
29/DC/TW
Area Forecast Discussion
National Weather Service Key West FL
1054 PM EDT Thu Jun 4 2020
.DISCUSSION...
The air mass over the Keys is still fairly worked over from
convection earlier today. The 00z KEY sounding showed a stable
layer from about 1,200 to 4,000 feet MSL, which has inhibited
development of convection near the Keys this evening. Strong
thunderstorms which moved northwest off Cuba late this afternoon
have ultimately weakened and blobbed out into a decaying area of
stratiform rain which will soon brush the Lower Keys.
In east-southeast low-level flow, we often see overnight
development of showers and thunderstorms over the Straits. The
experimental 00z Caribbean HRRR shows indeed shows convection
spreading across the Keys on Friday morning.
Later Friday, our mid-level flow will become more southerly and
strengthen, as we come under the far eastern periphery of
Cristobal`s circulation. The southerly flow will help scoop up
afternoon convection over Cuba and quickly whisk it across the
Straits toward the Keys late in the afternoon. So there are at
least two general opportunities for showers and thunderstorms over
the Keys in the next 24 hours.
&&
.MARINE...
An Atlantic ridge axis will extend westward across Central
Florida through Friday night. Tropical Depression Cristobal,
located inland over the southwest Yucatan Peninsula, is expected
to lift mainly northward on Friday. It will emerge over the
southern Gulf late Friday and then reach the central Gulf on
Saturday. As Cristobal moves north and re-strengthens on Saturday,
southeast breezes over the Keys waters will freshen. An Atlantic
ridge axis will build back across Florida starting Sunday night,
and winds will ease.
&&
.AVIATION...
Radar shows a few weakening remnant showers or light rain from
afternoon thunderstorms over Cuba will move north across the EYW
terminal in the next 2-3 hours. After that, a fairly quiet
overnight and morning is expected at both island terminals, with
plenty of mid-high level clouds. Then on Friday afternoon,
southerly mid-level flow will increase as Tropical Depression
Cristobal moves northward over the far western Yucatan Peninsula.
The strong southerly mid-level flow will readily bring afternoon
convection from Cuba northward to the Keys by late afternoon.
&&
.KEY WATCHES/WARNINGS/ADVISORIES...
FL...None.
GM...None.
&&
$$
Public/Marine/Fire...Haner
Aviation/Nowcasts....Haner
Data Acquisition.....NB
Visit us on the web at weather.gov/key
Follow us on Facebook and Twitter at:
www.facebook.com/nwskeywest
www.twitter.com/nwskeywest
Area Forecast Discussion
National Weather Service North Platte NE
655 PM CDT Thu Jun 4 2020
.SHORT TERM...(This evening through Friday night)
Issued at 329 PM CDT Thu Jun 4 2020
The short range model consensus suggests a severe storm or two will
form off the Black Hills late this afternoon and track into ncntl
Nebraska this evening or later. A stationary front drifting
through nrn Nebraska this afternoon will pool moisture and be an
excellent focus for storm development. The location of the front
this evening could very well dictate the track of the severe
weather.
The NAMnest indicates the storms will move east-southeast at 45 mph
and the HRRR shows a storm motion of 50 mph. The very fast motion
will place the activity in nrn Nebraska between 10 pm and
midnight. Discrete storm development is possible sooner. Winds
aloft are strong with a belt of 50kt winds at 500mb but no low
level jet is shown in the models. This would likely prevent a turn
to the south and keep the storms on an east-southeast course as
shown by the models.
The thunderstorm forecast tonight follows the down-scaled NAM which
tracks a cluster of storms through ncntl Nebraska farther south than
the other models. This forecast is consistent with the latest SPC
storm outlook.
Other isolated strong storms have formed off the Laramie Range
this afternoon and will move into wrn Nebraska. None of these
storms are expected to be severe. Winds aloft are strong relative
to the instability which suggests storms will collapse posing a
strong wind gust hazard.
The thunderstorm forecast Friday and Friday night uses the short
term model blend plus the down-scaled NAM. Wrn and ncntl Nebraska
will be post-frontal Friday and the easterlies should lift moisture
onto the high plains of WY causing storm development off the Laramie
Range. A strong cap and stable air prevents this activity from
moving east into wrn and ncntl Nebraska. A strong low level jet and
warm front develops Friday night. Isolated shower and thunderstorm
chances are in place for this warm front.
.LONG TERM...(Saturday through Thursday)
Issued at 329 PM CDT Thu Jun 4 2020
A powerful storm system will affect wrn and ncntl Nebraska Saturday
through Monday. The models are taking sfc low pressure across wrn
Nebraska and deepening it down to between 984mb and 990mb Sunday
evening. The best chances for severe weather are Saturday across
western Nebraska and Monday across ncntl Nebraska. Sunday`s
weather is an interlude to Monday`s potential event. Chance POP`s
are in place Saturday and Monday.
SPC has already outlooked much of wrn and ncntl Nebraska Saturday
for severe weather. Deep synoptic scale lift from an approaching
upper level trof, strong shear (near 50kts), and MLCAPE around
3000J/KG should easily support supercells across wrn Nebraska late
Saturday. Storm motion will likely be northeast as the upper level
flow is amplified north and south. A similar but less sheared
environment may develop Monday across ncntl Nebraska. The GFS is
giving a flood signal Monday with PWAT north of 1.50 inches and QPF
aligned mostly north and south.
This storm system will send a strong Pacific cold front through the
region Tuesday cooling temperatures and stabilizing the atmosphere
through Thursday. Just isolated thunderstorm chances are in place
during this time.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 648 PM CDT Thu Jun 4 2020
Scattered thunderstorms are possible across portions of north
central and southwest Nebraska this evening and overnight.
Thunderstorms are expected to move out of the area by early
morning. Winds will switch from the north to the southeast
tomorrow afternoon with VFR conditions.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SHORT TERM...CDC
LONG TERM...CDC
AVIATION...Gomez
Area Forecast Discussion
National Weather Service Newport/Morehead City NC
946 PM EDT Thu Jun 4 2020
.SYNOPSIS...
High pressure will move offshore tonight. Weak low pressure
will develop along the Southeast Coast, impacting the area
through Friday night. A cold front will then cross the area
early Sunday, followed by high pressure for early next week.
Another cold front will impact the area late next week.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
As of 930 PM Thursday...Clouds will inc overnight as moist SW
low-level flow inc, leading to a warm and muggy evening with
lows only in the 70s. Latest HRRR run shows a broken line of
showers and tstms moving in from the SW after 09z as a weak
mid-level low moves over the region.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/...
As of 940 PM Thursday...The weak mid-level low will continue
lifting across the area during the morning and early aftn with a
more well defined positively tilted trough following in it`s
wake. As a result, hi- res CAMs show another round of showers
and tstms developing late morning to early aftn. MLCAPE values
of 1000-2000 J/kg will allow for tstm development, but absence
of deep shear will keep any severe potential to a minimum.
Coverage will begin to taper off mid- to- late afternoon.
Despite expected cloud cover, a breezy Srly flow will allow for
aftn temps to rise into the low- to- mid 80s.
&&
.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
As of 345 PM EDT Thursday...
Fri Night through Saturday night...Unsettled this period as upr
trough develops to the W. Model consensus suggests a slower
frontal passage in the Sat night to Sun morning time frame and
adjusted timing and coverage of pops to account, but still
capped everything at chance PoPs for now. Another round of
showers and storms is possible Saturday ahead of the approaching
front. Highs mainly mid to upr 80s inland (although a few 90s
are possible) with low to mid 80s beaches.
Sunday through Tuesday...Cold front will cross Sun morning
followed by high pressure building in from the NW Sunday into
Tuesday. Both the GFS and ECMWF still show some potential for
shower/tsra lingering srn tier Sunday so have small pops these
areas all day. Will need to keep an eye on the progress of TS
Cristobal in the coming days. Latest guidance showing system
heading toward the western Gulf late in the upcoming weekend,
with associated moisture pooling along the weakening cool front
to our south into early next week. Drier air will spread in
post-frontal, with drier, slightly cooler/less humid conditions
through early next week with highs in the 80s through Tue.
Could see a return of aftn/evening showers/tstms on Wed as deep-
layer moisture starts to increase in advance of the approaching
upper trough/remnant low of Cristobal. GFS has trended towards
the drier ECMWF solution and will keep explicit mention of pops
out of the forecast until Wed night. Highs lingering in the 80s
next week, with early morning lows in the 60s to low 70s across
coastal communities.
&&
.AVIATION /01Z FRIDAY THROUGH TUESDAY/...
Short Term /Through 18Z Friday/...
As of 700 PM Thursday...VFR cond persist through tonight with
some gusty SSW winds early. Mid level clouds inc as deeper
moisture moves in after midnight with sct showers and perhaps a
tstm early Friday AM. A period of MVFR ceilings expected mid
morning/early aftn for some sites as sct showers and tstms
persist during the day.
Long Term /Friday Night through Tuesday/...
As of 345 PM Thur...ISO-Widely sct shra/tsra expected Fri night
and Sat ahead of approaching cold front with a few periods of
sub VFR conditions expected. Return to VFR conditions Sunday and
Monday with high pressure building in.
&&
.MARINE...
Short Term /Tonight and Friday/...
As of 340 PM Thursday...Winds have diminished to under 25 knots
with seas at 5 feet or less, so have lowered SCA for the
Ocracoke to Hatteras leg. S/SW winds will continue at 10-20
knots tonight and through Saturday with seas 3-5 feet through
the period.
Long Term /Friday Night through Tuesday/...
As of 345 PM Thur...SW winds Fri Night and Sat will be 15 to 20
kts with 3-5 ft seas cont...highest outer central and srn wtrs.
A few six footers are possible Saturday night for outer waters
shortly before a cold frontal passage but confidence in this is
below average. Winds shift behind the cold front Sunday to N/NE
nrn tier and W/NW srn tier 10 to 15 kt with 2-3 ft seas.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...None.
MARINE...None.
&&
$$
SYNOPSIS...MHX
NEAR TERM...ML
SHORT TERM...ML
LONG TERM...MS
AVIATION...MS/ML
MARINE...CTC/MS
Area Forecast Discussion
National Weather Service Marquette MI
755 PM EDT Thu Jun 4 2020
.SHORT TERM...(This evening through Friday)
Issued at 414 PM EDT THU JUN 4 2020
The large-scale upper-level pattern is defined by mostly zonal flow
with a southern stream closed low over southern California that will
become absorbed into the flow tomorrow. Closer to home, a mid-level
short wave is pushing eastward through the Canadian Prairies with an
attendant surface cold front analyzed by WPC through the Arrowhead
of Minnesota and then south into northwestern Wisconsin and southern
Minnesota. This cold front will be the main weather story this short-
term period as it will likely produce showers over much of the U.P.
as it swings through late tonight/tomorrow morning. CAMs are all
pretty much on board with lifting showers through the area around or
shortly after sunrise tomorrow. Isentropic lift on the 305 K surface
(around 650-750 mb) could support parcels realizing very thin, very
high elevated CAPE so have included a slight chance of thunder
across the south-central and east but really on the whole
thunderstorms are unlikely and certainly nothing strong or severe is
expected.
The NAM shows a burst of CAA/pressure rises with the immediate FROPA
resulting in 1-2 hours of blustery NW winds around 10-13z. While the
NAM taken verbatim would support 30-40 kt gusts for a very brief
time, did not go all the way with that solution and instead went
with 20-25 kt gusts across the Keweenaw and then central and east.
Then behind the front things dry out quickly from west to east late
morning tomorrow. Gusts pick up owing to cold advection steepening
lapse rates and allowing for effective mixing/momentum transfer with
the potential to tap into some 25 or even 30 kt gusts at the top of
the PBL, mainly over the west half. Subsidence behind this front
will also allow dew points to mix out well again - with the caveat
that mixing will be limited wherever there is decent rainfall.
There`s some indication that precip could miss the far west
entirely. If that did happen, the combination of gusty winds, highs
in the 70s to around 80, and afternoon RH around 25% could support
another day of elevated fire weather potential. But this remains
contingent on how much rain falls in the morning. By afternoon, some
models (the RAP and CMC hi-res) kick off an isolated shower or two
in the cyclonic wrap-around, so added in some slight chance POPs
over the interior tomorrow afternoon.
.LONG TERM...(Friday night through Thursday)
Issued at 252 PM EDT THU JUN 4 2020
Upper air pattern consists of a deep trough on the west coast, a
ridge over the Rockies into the southern plains, a shortwave over
the upper Great Lakes 00z Sat. The upper ridge moves into the
northern plains 00z Sun and amplifies on Sun. Went with low chance
pops on Sun with some dynamics and limited moisture moving through
the area, but with the ridge building and moisture being limited,
would not be surprised at all if this system ends up being dry.
No big changes made to the going forecast.
In the extended, the GFS and ECMWF show a deep and broad 500 mb
trough in the western half of the U.S. with a trough off the east
coast and a ridge over the upper Great Lakes 12z Mon with Cristobal
on the Gulf Coast. The deep trough moves into the Rockies 12z Tue
and starts to absorb the remains of Cristobal with the ridge still
over the upper Great Lakes. This trough moves through the northern
plains into the upper Great Lakes 12z Wed and remains over the area
into Thu. Temperatures go from above normal to below normal at the
end of this forecast period. Slow movement of sfc fronts will be the
rule for this forecast.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 755 PM EDT THU JUN 4 2020
VFR conditions are expected throughout the next 24-hours. Tonight,
winds will relax as we lose diurnal heating. A cold front currently
pushing into western Lake Superior will gradually push eastward
through the early to mid morning hours, favoring a wind shift from
west-southwest to west-northwest. Expect winds to come up after the
initial front passes, with gusts around 20-25kt. There could be a
brief lull behind the initial stronger gusts, but as mixing
increases behind the front on Friday afternoon expect west to
northwest winds to remain gusty. There could be a few afternoon
showers that develop near KSAW, so did include mentions of VCSH late
Friday afternoon.
&&
.MARINE...(For the 4 PM Lake Superior forecast issuance)
Issued at 414 PM EDT THU JUN 4 2020
A quick burst of NW winds up to 20-30 kts is possible with a cold
front passage tomorrow morning, mainly on the west half of the lake.
Confidence in strong winds is low, and they will be very brief (an
hour or two) if they occur at all, so did not explicitly put strong
winds in the forecast but wanted to note the potential here.
Otherwise winds are expected to be 20 kts or less across the lake
for at least the next 5 days. Satellite shows a few wisps of fog
remaining over the eastern half of the lake. As rain falls over the
lake tomorrow morning, fog may briefly regenerate, but once cooler
and drier air pushes in behind the cold front, expect that that will
all mix out and not persist past early afternoon.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
None.
Lake Michigan...
None.
&&
$$
SHORT TERM...RJC
LONG TERM...07
AVIATION...Ritzman
MARINE...RJC
Area Forecast Discussion
National Weather Service Nashville TN
938 PM CDT Thu Jun 4 2020
.UPDATE...
FOR EVENING DISCUSSION.
&&
.DISCUSSION...
The upper trough is making its way through middle TN and trying to
provide a slight punch. Had one hefty storm move through
Perry/Hickman/Lewis Counties that had good rotation at times. No
reports of damage but got several wall cloud and funnel cloud
reports. Updated the forecast to better correlate with radar and
tried to time the line. The HRRR still shows the line trying to
dissipate after it crosses I-65 but have not removed pops.
&&
.AVIATION...
00Z TAF DISCUSSION.
BNA/MQY/CKV/CSV...Scattered showers have been around Middle TN
this afternoon. The upper trough is approaching the area and will
move through CKV by 03Z...BNA/MQY 03-05Z and CSV 06-08Z. Outside
of the line associated with the upper trough VFR conditions are
anticipated. With the trough heavy rainfall with IFR VIS and MVFR
CIGs could occur. CIGs could remain MVFR for CSV before sunrise.
Tomorrow more afternoon showers and isolated thunderstorms.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
DISCUSSION......12
AVIATION........12
Area Forecast Discussion
National Weather Service New York NY
925 PM EDT Thu Jun 4 2020
.SYNOPSIS...
A convective complex tracks across Pennsylvania and impacts the
area late tonight. A cold front will slowly approach from the
west on Friday. A cold front moves across Saturday and southeast
of the region Saturday night. High pressure will begin building
into the region on Sunday and more so for early to mid next
week. High pressure breaks down towards the end of next week.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
Slight adjustments were made to temperatures, dewpoints, cloud
coverage and POPs for showers. POPs go to likely overnight for
showers but kept thunderstorms to chance along the southern
coasts including NYC and Long Island but slight chance to the
north. Models are showing negative Showalter Indices to the
south and they become less negative farther north so there is
forecast to be some elevated instability to work with.
The models have been pretty good with picking up the developing mcs
over OH. This sys is progged to track ewd tngt and impact the area
between about 4Z and 10Z. Although the models do provide some
confidence, the mcs has a long way to go which could impact
timing and placement. Strong cold pool development could result
in a sewd trend in the sys. The NAM has additional initiation
due to the increasing lljet over srn/cntrl NJ tngt which would
cut off the inflow and significantly weaken the tstms impacting
the cwa.
Further complicating the picture, there were shwrs developing across
nern PA this aftn. These will get here much earlier than 3z if they
hold together. While the NAM does have some hint of this activity,
the HRRR has nothing on it right now. Because of these many
uncertainties, pops based on the 12z HREF have been capped at high
chance. Sct pops for shwrs were also manually added for the next few
hours for wrn portions of the area.
SBCAPE is progged to be minimal, so if there is a svr risk it is
most likely w of the Hudson before it becomes elevated attm.
The NBM was used for temps.
There is a high rip current risk through this evening
at the ocean beaches from Smith Point NY to Montauk Point NY. This
is due to 5 ft S-SE long period swells. There is a moderate rip
current risk at the ocean beaches west of Smith Point NY through
this evening where swells will be 3 to 4 ft.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/...
Friday is another complicated fcst. Any mcs activity should be gone
by 12Z. Higher humidity will be left in place, resulting in
increasing instability with a weakening cap. With active zonal flow
aloft, initiation will be possible at any time from late mrng on.
This may help to limit svr chances by working over the atmosphere or
keeping down the heat. It is notable that the MAV and MET are as
much as 10 degrees cooler than the NBM across wrn areas. Although
the fcst goes with the NBM attm due to expected breaks in the clouds
during at least the first part of the day, temps in the MAV/MET
range would limit tstm intensity.
Winds in the llvls are backed a bit per the 12Z NAM, so this may
need to be watched for wrn areas, particularly if they back closer
to sly as opposed to swly and CAPE is allowed to build. A lot of
variables and a lot of uncertainty right now. Pops were 12Z HREF and
capped at chance.
A prefrontal trof associated with the approaching cold front may
pass Fri ngt, sweeping any convection out to sea overnight. Pops
transition to the NBM Fri ngt, with the NBM used for temps.
There currently is a high rip current risk at the ocean beaches
Friday due to 5 ft S-SE long period swells. However, there is a
chance the swells are a bit less which would lead to a moderate rip
current risk.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
Strong shortwave moves across Saturday into Saturday night that will
accompany a cold front passage at the surface. The forcing combined
with increasing instability will allow for a chance of showers and
thunderstorms. Moisture looks to be a limiting factor with several
models showing a mainly dry passage. However, weighed the wetter
model solutions of GFS more heavily considering the factors for lift
that will be met.
The shortwave axis pushes through the region Saturday night and will
be southeast of the region Sunday. Showers and thunderstorms taper
off during the evening Saturday. On the backside of the trough
though, a vort max will be moving across Sunday into Sunday night.
At the surface, the cold front will move southeast of the region
Saturday night and farther offshore Sunday. A weak upper level
disturbance may present some possible showers and thunderstorms
Sunday into Sunday night for interior and eastern areas.
Otherwise, steady height rises with strong upper level ridging
moving in for early to mid next week with accompanying high pressure
building in at the surface. A long stretch of dry weather is
anticipated lasting into middle of next week. Ridge breaks down by
next Wednesday night into Thursday which is when the next chance for
rain showers will be as weak low pressure approaches.
With temperatures and humidity, warm and humid Saturday
(forecast highs in upper 70s to mid 60s, forecast dewpoints
well in the 60s), cooler and less humid Sunday and Monday (
forecast highs in the 70s, forecast dewpoints in the upper 40s
to lower 50s). Temperatures and humidity trend a littler higher
for Tuesday and Wednesday of next week with forecast highs more
in the upper 70s to low 80s range.
&&
.AVIATION /02Z FRIDAY THROUGH TUESDAY/...
A weak wave and warm front approach and lift through the area
overnight.
MVFR with isolated IFR possible in showers and isolated
thunderstorms. Shower activity should pass east by the morning
push, but MVFR/IFR cigs likely for the morning push. Improvement
to VFR likely late morning into early afternoon, with a likely
return of MVFR/IFR late Friday into Friday evening. Additional
shower and thunderstorm activity likely to move through the
terminals Friday afternoon through the evening.
Light onshore flow tonight into morning push, giving way to S
winds of 5-10 kt on Friday.
.OUTLOOK FOR 00Z SATURDAY THROUGH TUESDAY...
.Fri Night...Showers and thunderstorms possible with IFR.
.Sat...Becoming VFR am. W/SW gusts 15-20 kt, becoming NW gusts
20-25 kt in the evening. Chance of shower and thunderstorm in
the evening.
.Sun...VFR. NW gusts 15-20 kt.
.Mon-Tue...VFR.
&&
.MARINE...
Seas on the ocean will continue to subside tngt. 44025 is down to 4
ft, the the sca has been canceled for the cntrl ocean. Seas come
back up on the ocean Fri however, so the sca on the ern ocean was
extended, and an advy issued for the remaining ocean zones. Seas may
remain at sca lvls Fri ngt.
Sub-SCA conditions are forecast this weekend through early next week
across all waters.
&&
.HYDROLOGY...
Minor hydrologic impacts cannot be ruled out on Fri where heavier
tstms develop.
Other than some brief heavy downpours with any stronger showers and
thunderstorms on Saturday with possible minor flooding, no other
hydrologic problems anticipated during the long term.
&&
.TIDES/COASTAL FLOODING...
Widespread minor coastal flooding is expected with tonight`s
high tide cycles as we approach a full moon, particularly the
South Shore Bays and shorelines along Southern Westchester NY and
Southern Fairfield CT. Coastal Flood Advisories remain in
effect for southern Queens/Nassau and coastal Fairfield and
Westchester Counties. A statement remains in effect for
locations along the NY Harbor and northwest Long Island along
the Western Sound. The forecast surge tonight is around 0.5 ft
for most locations.
While astronomical tides will still be running high Friday night
with the full moon, forecast surge is a few tenths of a foot
less, making the total water levels just touch or slightly
exceed minor coastal flood benchmarks for the South Shore Bays
and the Southern Fairfield CT shorelines with other locations
falling short of minor coastal flood benchmarks.
&&
.EQUIPMENT...
NYC NOAA Weather Radio Station KWO35 (162.55 MHz) is undergoing
its final stages of testing, and is operating at full power.
KOKX WSR-88D radar will be down until approximately June 15 for
the pedestal refurbishment.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...Coastal Flood Advisory until 1 AM EDT Friday for CTZ009.
NY...Coastal Flood Advisory until 1 AM EDT Friday for NYZ071.
High Rip Current Risk from 6 AM EDT Friday through Friday
evening for NYZ075-080-178-179.
Coastal Flood Advisory until 10 PM EDT this evening for NYZ178-
179.
High Rip Current Risk through Friday evening for NYZ081.
NJ...None.
MARINE...Small Craft Advisory from noon to 8 PM EDT Friday for ANZ353-
355.
Small Craft Advisory until 8 PM EDT Friday for ANZ350.
&&
$$
SYNOPSIS...JM
NEAR TERM...JM
SHORT TERM...
LONG TERM...JM
AVIATION...NV
MARINE...JM
HYDROLOGY...JM
TIDES/COASTAL FLOODING...
EQUIPMENT...
Area Forecast Discussion
National Weather Service Mount Holly NJ
958 PM EDT Thu Jun 4 2020
.SYNOPSIS...
Unsettled weather will continue through the next several days
as multiple upper level disturbances move across the area,
before a cold front moves across the Mid Atlantic region
Saturday. High pressure will build across the northeast and Mid
Atlantic regions Late Sunday through at least Tuesday. Unsettled
weather may return toward the end of the week next week.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
945 PM Update...As of mid evening, one area of storms
congealing into a N-S oriented line and closing in on SE PA and
Delmarva. Still upwards of 500-1000 j/kg of ML CAPE here so
still at least some potential for storms to be strong to severe
but we don`t expect this to match the high end severe weather we
saw Wednesday. Additional showers/storms were located farther
north as of the mid evening across parts of the Lehigh Valley
into the southern Poconos. Instability is lower here so don`t
see much of a severe threat but given that these are tending to
train, this will have to be monitored for hydro issues over the
next several hours. Biggest threat would be small stream
flooding and flooding of lower lying flood prone areas.
Showers/storms look to wind down overnight.
Previous Discussion: Fairly tricky forecast tonight, with the
convective evolution the obvious challenge. Storms are
developing rapidly this afternoon in central Pennsylvania south-
southwestward through southwest Virginia and adjacent West
Virginia. Several low- amplitude perturbations are moving east-
northeast across the Northeast/Mid-Atlantic. With strong
differential diabatic heating and orographic effects, sub-
synoptic lift has proven sufficient for convective initiation a
little bit earlier than most high-resolution guidance has been
depicting today. Meanwhile, a convectively-enhanced perturbation
moving through the upper Ohio Valley has generated vigorous and
well-organized convection in Ohio.
Unfortunately, high-resolution convection-allowing guidance has been
quite variable with the evolution of these two initially separate
regions of convection during the past day or so. However, there has
been some approach to convergence with the 12z/subsequent
simulations. In general, (1) the MCS in Ohio is expected to track
into central Pennsylvania and weaken in the higher terrain with the
loss of daytime heating, (2) another MCS may develop from the
convection in western Virginia and attempt to reach Delmarva after
sunset (though models are trending away from this, in general), and
(3) fairly disorganized/pulse-like convection in central
Pennsylvania and adjacent portions of Maryland/Virginia is progged
to congeal into a band or bands of convection in eastern
Pennsylvania and northern/central New Jersey (perhaps aided by
outflow from the upstream MCS). An examination of upper-air analyses
and satellite data would suggest that the stronger large-scale lift
will remain north of the Maryland border. With this in mind, have
trended PoPs higher to the north for late evening through the
overnight hours, with the highest PoPs between 00z and 06z. However,
concerned that convection will move in faster via recent radar
trends, so we may make some fairly quick adjustments as needed.
The severe-weather parameter space is sufficient for severe storms
(MUCAPE > 1000 J/kg; deep-layer vertical shear of 30-40 kt), though
low-level stability will increase via gradual nocturnal cooling. The
threat for heavy rainfall remains too, although think storm motions
are sufficiently high to preclude a larger threat of flash flooding.
In other words, I think the threat of severe storms is higher than
the threat of flash flooding.
Once the convection wanes (hopefully) after midnight, potential for
some localized fog may occur (similar to last night). However, left
this out of the forecast for now, as convection-allowing models have
hinted at potential for lingering showers/isolated storms
(especially recent HRRR simulations). Given the large uncertainty
with the precipitation forecast, did not want to provide too much
specificity to the grids afterward (at this point).
Lows tonight will be quite warm, with most readings in the 60s to
around 70.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/...
Concern is increasing tomorrow for another round of severe storms,
and heavy rainfall is also quite possible.
A stronger perturbation is expected to move into the Northeast by
Friday afternoon, with a surface trough attendant to this
perturbation moving into western portions of the CWA by afternoon.
Large-scale lift in advance of the trough combined with mesoscale
lift via the aforementioned trough, differential heating, and
orographic effects should readily generate convection by early
afternoon. The problem is that the orientation of the trough will be
increasingly parallel to the midlevel flow. The question will be how
parallel, as this will have implications on the progression of the
convection (e.g., the 12z GFS implies less parallel orientation and
quicker progression of the convection as a result; the 12z NAM is
slower and suggests very heavy rainfall possible in advance of the
slowly moving trough). Current thinking is that the slower
advancement of the trough is likely, especially on the northeast
side of the trough (where there is increased consensus for a more
west-to-east orientation of the boundary). Should this slower
progression materialize, some areas of the CWA will likely receive
high rainfall totals (2+ inches probable; 3+ inches possible). For
now, confidence is too low for a flash flood watch (particularly
given uncertainty with antecedent convection), but not ruling out
the possibility with future forecast updates.
Meanwhile, the severe-weather parameter space also remains favorable
for severe storms, with SBCAPE 1500-2000+ J/kg and deep-layer shear
of 25-35 kt possible by afternoon. Threat for wet microbursts
exists, with a more organized wind threat possible should a stronger
cold pool develop. Timing appears to be generally after midday and
mostly northwest of the urban corridor until the early evening, with
a slow progression east/southeast during the evening/overnight
hours. Threat for severe weather will likely peak in the late
afternoon/early evening, with the heavy rainfall threat possibly
existing longer in time thereafter.
Temperatures on Friday and Friday night will remain quite warm, with
mid 80s to low 90s for highs and upper 60s to low 70s for lows.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
After several days of active weather, including the beginning
of the long term period, quiet conditions return for much of the
rest of the extended period through the middle of next week,
before more potential unsettle weather returns by the end of the
week.
The beginning of the long term starts off with one final round
of showers and thunderstorms as a cold front will finally move
across the area. CAPE values build to 1000-2000 J/kg, while
shear is forecast to be 35-40 knots due to 700-500 mph winds of
30-40 knots. There will be some enhanced lift due to the front,
although not much significant short wave/vorticity impulses are
expected. However, with PWs increasing to 1.5-1.75 inches, any
showers or thunderstorms that do develop could contain a brief
period of moderate to heavy rainfall.
Behind the cold front, quiet conditions return to the area
beginning Sunday and continuing through the first half of next
week as high pressure builds across the northeast states and Mid
Atlantic region. For Sunday, the main concern will be the
potential for winds to gust around 15-20 mph, but winds for
Monday and Tuesday will be much weaker. Temperatures Sunday and
Monday return close to normal, before returning above normal on
Tuesday.
The high begins to get squeezed by Tuesday night into Wednesday
as a cold front approaches from the west, and an area of low
pressure approaches the east coast from the western Atlantic.
As we go into Thursday, the GFS and ECMWF begin to differ with
their outcomes. The GFS hangs the front to our west and keeps
the low offshore, while the ECMWF brings the front across the
eastern seaboard, before bringing the weak low across the area.
The ECMWF has a better chance of showers than the GFS, so we
will keep a chance of showers from late Wednesday into Thursday.
&&
.AVIATION /02Z FRIDAY THROUGH TUESDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas.
Tonight...Showers/storms look to affect most of the I-95
corridor sites and points north through late this evening
bringing temporary restrictions to IFR. After storms progress
east and/or dissipate overnight, local fog and/or lingering low
cloudiness may develop with additional periods of MVFR or even
IFR possible. Light south to southwest winds becoming light and
variable (outside of convection). Low confidence, particularly
after 06z.
Friday...Any lingering (local) fog and/or low clouds in the morning
becoming VFR quickly. However, storms are expected to develop
northwest of the urban corridor during the afternoon (including
RDG/ABE; generally after 18z), possibly affecting the Philly
terminals by 00z. Restrictions likely in proximity to storms. South
to southwest winds 5 to 15 kt. Strong/erratic gusts and torrential
downpours likely with the stronger storms. Moderate confidence.
Friday night...Storms with local restrictions likely, especially in
the evening. Residual restrictions late in the overnight possible.
Southwest winds up to 10 kt. Low confidence.
Outlook...
Saturday...Mostly VFR conditions expected. A chance of showers
and thunderstorms, which may temporarily lead to lower
conditions. West winds become northwest during the afternoon
with gusts 15-20 knots.
Saturday night-Tuesday...VFR conditions are expected through
the period.
&&
.MARINE...
South to southwest winds 10 to 20 kt are expected tonight through
Friday night, with seas generally below 5 feet. Cannot rule out a
marginal advisory gust or a period of seas around 5 feet, but
conditions are expected to remain predominantly sub-advisory.
A chance of storms exists tonight and again tomorrow evening/night.
Strong/erratic gusts, locally higher waves, and torrential downpours
are expected with the strongest storms.
OUTLOOK...
Saturday...Conditions expected to remain below advisory levels.
However, there will be a chance of showers and thunderstorms
Saturday afternoon which may contain gusty winds.
Saturday night-Tuesday...Conditions expected to remain below
advisory levels through the period, but winds may gust around 20
knots at times Saturday night through Sunday night.
&&
.TIDES/COASTAL FLOODING...
The astronomical tides associated with this full moon are
particularly high, especially the high tide this evening and
tonight. Only a modest positive tidal departure will result in
minor flooding this evening.
Tidal departure this evening will range from +0.5 to +1.0, and
this will be enough to produce minor coastal flooding along the
New Jersey and Delaware oceanfront, many of the Atlantic bays,
as well as Delaware Bay, and up the Delaware River.
South to southeast flow will result in a buildup of water that
will continue into tonight. As a result, went ahead and expanded
the Coastal Flood Advisory to include all coastal areas
tonight.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...Coastal Flood Advisory until 5 AM EDT Friday for PAZ070-071-
106.
NJ...Coastal Flood Advisory until midnight EDT tonight for
NJZ012>014-020>027.
Coastal Flood Advisory until 5 AM EDT Friday for NJZ015-
017>019.
Coastal Flood Advisory until 1 AM EDT Friday for NJZ016.
DE...Coastal Flood Advisory until midnight EDT tonight for
DEZ002>004.
Coastal Flood Advisory until 1 AM EDT Friday for DEZ001.
MD...None.
MARINE...None.
&&
$$
Synopsis...Robertson
Near Term...CMS/Fitzsimmons
Short Term...CMS
Long Term...Robertson
Aviation...CMS/Fitzsimmons/Robertson
Marine...CMS/Robertson
Tides/Coastal Flooding...
Area Forecast Discussion
National Weather Service Topeka KS
1009 PM CDT Thu Jun 4 2020
.UPDATE...
Issued at 952 PM CDT Thu Jun 4 2020
Looking a bit more favorable for a complex of severe
thunderstorms to develop across north central KS and spread east
and southeast across the CWA after midnight. MUCAPE will be
4000-5000 J/KG with 30 to 35 KTS of effective shear. Scattered
storms may have a large hail threat late this evening across north
central KS but storms should congeal into line segments where
damaging wind gusts will be more favorable as they propagate
southeast along the higher theta e axis across the eastern half of
the CWA. Also downdraft CAPE ranged between 1500-1700 J/kG across
the CWA, so severe wind gust may be more widespread if a complex
of storms does develop. If the complex of storms develops, they may
reach Topeka and Lawrence by 8Z. There continues to be a bit of
uncertainty since the 3KM nam and the non-hydrostatic versions of
the WRF model keeps the complex of storms across southern NE then
turns the complex southeast across far northeast KS, and there
continues to be 50 to 100 J/kg CIN across the CWA, so if the OFB
weakens there may not be enough ascent for storm to develop across
the CWA.
I extened chance POPs down into east central KS increase a
complex of storms does develop and propagates southeast across the
CWA. PoPs will be updated from now on based on mesoscale trends.
UPDATE Issued at 827 PM CDT Thu Jun 4 2020
Updated to insert some low end chance PoPs across the northern
counties across the CWA. This is a low confidence forecast, since
the only model now showing thunderstorms developing on an outflow
boundary across southern NE and north central KS by 5Z FRI is the
HRRR model. The experimental (ESRL) HRRR dissipates the
thunderstorms across northwest KS and south central KS. SPC has
now extended the slight risk into the northern half of the CWA. If
storms do develop they rapid intensification will be possible with
MUCAPE around 5000 J/KG across northeast KS. The effective bulk
shear will be around 35 KTS across the northern counties which
would be sufficient for isolated to scattered updrafts to produce
large hail and damaging wind gusts and the HRRR model forecast the
scattered severe updrafts to congeal into line segments in which
damaging wind gusts portions of the CWA north of I-70. Therefore,
the hazardous severe weather will be very conditional on sfc
based or elevated storms developing later this evening. As the 00Z
guidance from other CAMs come in I may update PoPs in the next
hour or two.
&&
.SHORT TERM...(This evening through Friday)
Issued at 236 PM CDT Thu Jun 4 2020
As of 20Z Thursday afternoon broad WNW midlevel flow was present
across the Central Plains with an amplifying ridge across the
SW US. Similar to Wednesday, a very subtle shortwave trough is
traversing SW KS, resulting in scattered thunderstorm development
near DDC. The current trajectory of this subtle shortwave trough
should keep any convection well-south of the area, especially with
a stout EML overhead. At the surface a very diffuse frontal zone
extends from SW KS, northward into central NE and eastward into
central IA. In addition, the diurnal dryline extends along the
foothills of the Rockies across eastern CO and western NE. Latest
satellite trends suggest thunderstorm development is occurring
along the dryline. Additional development is expected further
north across western SD as a midlevel speed max overspreads the
Black Hills. The convective development in each area will
ultimately grow upscale this evening. The incoming midlevel speed
max will tend to provide MCS maintenance for upscale growth across
the Northern Plains into the mid-Mo valley region. This complex
of storms will likely follow an instability gradient this is
progged to extend from northeastern NE through northern MO. Will
maintain a slight chance for storms in extreme northeast KS for
the potential that an OFB sinks into the region, allowing for
additional development. Should any storms develop and/or reach
northeast KS, damaging winds and large hail would be the primary
concerns. The second zone for convective development across
eastern CO and western NE is likely to weaken and diminish upon
reaching north- central, given the lack of MCS maintenance, owing
to a lack of mid-level ascent. The HRRR has been consistent with
bringing the decaying MCS into portions of the area, however HRRR
forecast soundings suggest this is over-done.
By Friday, the very conditional thunderstorm potential will return
by afternoon. Model solutions suggest a weak frontal zone will sag
into the area by afternoon. A tremendous EML will remain in place
and should preclude any thunderstorm development. If a storm does
develop, it could become severe with large hail and damaging
winds. Otherwise, another warm and humid day is expected with
highs in the low to mid 90s. Heat index values will range from the
upper 90s along the NE border to the lower 100s along/south of
I-70.
.LONG TERM...(Friday night through Thursday)
Issued at 236 PM CDT Thu Jun 4 2020
Transitioning into the extended period, additional thunderstorm
development is possible late Friday night into Saturday morning as
a weak shortwave trough ejects across the mid-MO valley region. At
this point, the best chance for any thunderstorm activity may
remain northeast of the forecast area. Should storms reach
northeast KS, large hail and damaging winds would be a concern.
The pattern looks drier into the weekend as the aforementioned
SW US ridge axis amplifies and overspreads the area. This will
allow for the warm and humid conditions to persist into early next
week. Highs will low to mid 90s Saturday through Monday with heat
index values approaching 100 degrees, especially Saturday and
Sunday.
We continue to track the remnants of Tropical Storm Cristobal for
Tuesday into Wednesday. Latest ECMWF and GFS runs suggest the
potential for its remnants to progress across portions of MO and
possibly eastern KS. A swath of several inches of rainfall will be
probable as it lifts northeastward. Continue to check back
throughout the weekend for forecast updates.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 631 PM CDT Thu Jun 4 2020
Expect VFR conditions. There may be sct-BKN high clouds moving
across the terminals late Tonight, left over from thunderstorms
across western NE and western KS. At this time, most models show the
showers diminishing before reaching the terminals during the
early morning hours of Friday. However, the HRRR model develops a
complex of storms which may translate southeast to the terminals
after 5Z Friday.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Gargan
SHORT TERM...Baerg
LONG TERM...Baerg
AVIATION...Gargan
Area Forecast Discussion
National Weather Service Las Vegas NV
750 PM PDT Thu Jun 4 2020
.SYNOPSIS...It won`t be as hot Friday as a low pressure system
swings up across Southern California and toward the Four Corners
region Friday night. A broad area of low pressure will then move
over the western states this weekend and early next week with breezy
afternoon winds and significant cooling.
&&
.UPDATE...Will be allowing the excessive heat warning to expire on
schedule at the top of the hour.
Will be issuing a lake wind advisory for the Lake Mead Natl Rec Area
tomorrow afternoon as the southerly winds increase producing higher
wave action. That will run from Noon until 8 pm PDT. Otherwise, no
changes.
&&
.PREV UPDATE...255 PM PDT THU JUN 4 2020
.AFTERNOON UPDATE...
Went ahead and upgraded the Fire Weather Watch to a Red Flag Warning
and updated the Excessive Heat Warning as it went into effect this
morning. Temperatures are currently trending about on track so no
changes to the numbers. Also, watching CU development across the
Sierra and northern zones but no CI at the moment. Still have some
slight chance thunder there through 00Z-03Z so no changes to PoP
either.
&&
.SHORT TERM...Today through Saturday.
For today, the main weather concern continues to be the excessive
heat across Death Valley, southern Nevada, and the Colorado River
Valley. While most guidance actually has decreased temperatures a
degree or so this morning, hourly trends are above this point
yesterday and did not feel confident in lowering temperatures are
this point. So no changes to the temperature forecast or warning
areas.
Beyond the heat, some isolated showers and thunderstorms with the
passage of this low today and tomorrow is the next area of focus.
At least today, another round of isolated convection off the
Sierra range looks possible, which could impact KBIH. HRRR
continues to advertise the potential for some strong outflow winds
and proximity soundings do show very dry lowest 300 mb so this
will need to be watched closely this afternoon. The better chance
for convection looks to be again tomorrow afternoon as the low
pushes onshore. There is still quite a question on whether this
low will push farther south and swing wide of its current track.
if so, these PoPs may decrease substantially, but for now, there
is still synoptic and hi-res backing on another round of isolated
convection for northern Inyo through Esmeralda and into central
Nevada tomorrow as well. Will address fire weather implications in
the Fire Weather section below.
Secondarily, while winds tomorrow will be breezy region wide,
advisory criteria looks to be met across the western Mojave
desert, if not the next few days. Farther west, winds aren`t as
impressive, but may be high enough to warrant a Lake Wind Advisory
for tomorrow as well. Thus, a few wind products may be warranted
this afternoon as well.
.LONG TERM...Sunday through Thursday.
After Saturday, the aforementioned system will push quickly to the
northeast and a broader area of low pressure will take shape over
the Northwest. The low axis looks to push over the area Sunday and
that will result in much cooler temperatures region wide. Highs in
Las Vegas will likely only reach the 80s.
Moving into next week, the broader low moves east and some quasi-
zonal, perhaps weak ridging will set up over the western CONUS
through mid-week. The ridge strength is up for debate between the
synoptic models when looking at cluster analysis for Wednesday.
NBM temperatures are leaning more towards a fast warm up for the
latter half of the week so it appears to be trending the direction
of the stronger ridging. This makes sense given the ECMWF ensemble
clustering steadfastly indicating a more amplified ridge vs the
overall mean. So no changes to the NBM in the long term.
&&
.FIRE WEATHER...
With the continued expectation for gusty winds and very dry
conditions across Mohave/Clark/Lincoln counties tomorrow, will be
upgrading the Fire Weather Watch to a Red Flag Warning tomorrow
through coordination with the GACC and neighboring offices. There
is some potential for fire starts due to lightning across the
Sierra north of Mount Whitney both this afternoon and again
Friday, but this should be very isolated. QPF is fairly impressive
as well per the HREF, especially tomorrow. As a result of decent
QPF generation and the isolated nature of the lightning potential,
did not feel confident enough to warrant any fire products for
lightning in Inyo or Esmeralda at this time.
&&
.AVIATION...For McCarran...For today, expecting an increase in
south-southeasterly winds slowly shifting to an eventual
southwesterly direction by this evening. Gust potential could
increase to 20-25kts this afternoon with VFR high clouds
developing as well. This may result in some configuration issues,
especially as winds initially increase this afternoon. After
sunset, this should subside and stay southwesterly before becoming
light in the early morning. Another increase in southeasterly
winds is expected again tomorrow afternoon, with gust potential
possibly over 30 kts as well.
For the rest of southern Nevada, northwest Arizona and southeast
California...The main aviation hazard for the region today will be
some isolated -TSRA possible in the vicinity of KBIH which could
produce some gusty outflow winds for the terminal and create some
turbulence for approaches over the Sierra. This looks like it will
be between 21-00Z for the most part then pushing to the north of
the terminal afterwards. Other locations across the region will be
looking at gusty afternoon winds and VFR cloud development but
overall low impacts.
&&
.SPOTTER INFORMATION STATEMENT...Spotters are encouraged to report
any significant weather or impacts according to standard operating
procedures.
&&
$$
UPDATE...Pierce
DISCUSSIONS/AVIATION...TB3
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