Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 06/06/17
Area Forecast Discussion
National Weather Service Denver/Boulder CO
933 PM MDT Mon Jun 5 2017
.UPDATE...
Issued at 933 PM MDT Mon Jun 5 2017
Convection waning in the cooler air. Some weak storms should
linger out near the eastern border for a couple more hours. Trends
are for a bit more clearing in the middle of the night, then
what`s left of the shower band now over the northwest corner of
Colorado will pass over the mountains toward sunrise. HRRR has
been waffling on whether there is any precip left with this, but
it could complicate the frontal passage. Last couple HRRR runs
have been a bit slower with the main front, but have some kind of
westerly or northerly wind surge with the shower band remnants in
the 4-6 am time frame. For now just minor adjustments to the
forecasts mainly to reflect the current conditions and a low
chance of showers late tonight.
&&
.SHORT TERM...(This evening through Tuesday)
Issued at 320 PM MDT Mon Jun 5 2017
Strongest convection has pushed out onto the plains and continues
to develop along the convergence zone created by outflow from earlier
foothills convection, and the east/southeast flow on the plains.
Have already had a couple of pulse severe reports, and still some
potential with sufficient CAPES near 1500 J/kg. Those storms will
continue through early evening before gradually diminishing as
they move into a more capped environment on the eastern plains.
Behind that, scattered showers and less intense thunderstorms were
occurring over the mountains, but airmass was slowly stabilizing.
A couple could still drift off the Front Range and back into the
I-25 Corridor, but bulk of activity is largely on the way down for
these locations. Don`t expect more than a couple showers to
linger in the mountains and far eastern plains past late evening.
Cold front is expected to push across the plains late tonight into
early Tuesday. We are not certain on the cold frontal progression
at this time. It seems most models have backed off on how far
south and how pronounced this front will make it, so that may
allow more instability and some severe storm threat across the
plains. We still think the front should have sufficient push with
northwesterly flow aloft in place, but something to watch for
tomorrow. If the front does not push through in a strong manner,
then look for less CIN (convective inhibition) and potential CAPES
near 1500-2000 J/kg. Shear is still weak however, so that would
be a mainly pulse severe threat. Will continue to monitor this
potential through tomorrow. Otherwise, kept a pretty good chance
of storms (highest across the Front Range and Palmer Divide where
moisture banks up into the high country). Temperatures will be
several degrees cooler as long as front arrives on time.
.LONG TERM...(Tuesday night through Monday)
Issued at 320 PM MDT Mon Jun 5 2017
Showers and tstms will linger thru Tue evening especially over the
higher terrain and Palmer Divide. On Wed an upper level ridge will
begin to build over the srn Rockies with weak nwly flow aloft. At
the sfc, the low lvl flow will be ese which will keep decent
moisture in the lower levels fm the plains into the foothills. Would
expect to see sct storms dvlp in the foothills by early to mid aftn
with some of the activity affecting portions of the urban corridor
and Palmer Divide by late aftn into the early evening hours.
Could see an isold svr storm or two due to a slightly better shear
profile. As for highs will keep readings in the upper 70s to
lower 80s across the plains.
On Thu the upper level ridge will begin to move northward into the
area with some increase in nwly flow aloft. Moisture will begin to
decrease over the higher terrain with tstm activity becoming more
wdly sct. Across the plains the low lvl flow will become more sse
with cape values nr 1000 j/kg along the urban corridor and up to
2000 j/kg over the far ern areas. With sse low lvl flow will
probably see a Denver Cyclone along with a convergence zone east
of the the urban corridor. If the cap can be bkn then there would
be a better threat of a few svr storms due to an improving shear
environment. The other area for possible storm development would
be near the Cheyenne Ridge with storms moving se across nrn Weld
County. As for highs with decent warming occurring in the 850-700
mb lyr expect highs to rise into the mid to upper 80s across nern
CO.
By Fri a stg storm system will move into thr Pacific NW with the
flow aloft becoming more swly as the upper level ridge flattens.
Overall this will lead to dry conditions with warmer temperatures
as the first 90 degree day of the season will likely occur at
Denver. There will be a dry line over the far ern plains however
mid lvl cap will probably inhibit tstm development nr this bndry.
On Sat the upper level trough will move east with stg swly flow
aloft. This will lead to another dry day with abv normal temps as
readings reach the lower to mid 90s.
By Sun the ECMWF and GFS differ some as the ECMWF has the upper
level trough extending fm the nrn high plains into wrn CO. Meanwhile
the GFS keeps the trough further west. As a result the ECMWF has a
cold front moving across nern CO on Sunday while the GFS does not.
Thus the ECMWF would have highs lowering into the lower to mid 80s
while the GFS would keep readings in the lower to mid 90s.
For Sun night into Mon the ECMWF has a wk upper level trough moving
across with a chc of pcpn mainly Sun night into early Mon. Meanwhile
the GFS is roughly 24 hours slower with the upper level trough and
doesn`t have it moving across until Mon night. Thus it has the best
chc of pcpn Mon aftn into Mon night. At this point will keep in a
slight chc of pcpn with cooler temps.
&&
.AVIATION...(For the 06Z TAFS through 06Z Tuesday night)
Issued at 933 PM MDT Mon Jun 5 2017
VFR through tonight. Lower ceilings will likely require instrument
approaches to KDEN for much of the day Tuesday, with localized
MVFR possible. Scattered thunderstorms are also expected after
18z with gusts to 40 knots, brief heavy rain, and small hail
possible.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
UPDATE...Gimmestad
SHORT TERM...Barjenbruch
LONG TERM...RPK
AVIATION...Gimmestad
Area Forecast Discussion
National Weather Service Caribou ME
1017 PM EDT Mon Jun 5 2017
.SYNOPSIS...
High pressure will build southward from the Canadian maritimes
trough the mid week as low pressure passes to the south of the
region.
&&
.NEAR TERM /THROUGH TUESDAY/...
1015 PM Update...
Adjusted the pops to keep them across the western areas such as
northern Somerset and western Piscataquis County aligning w/the
radar and latest HRRR. Meso-analysis showed some moisture
convergence in this area, but the HRRR showed the convergence
weakening overnight w/showers dissipating. Surface analysis
showed high pres to the ne providing dry air to 2/3 of the CWA.
Temps have dropped off and are in the upper 40s across the Crown
this evening due to the clearing as seen by the latest IR satl
imagery. Drier air is forecast to slowly seep s overnight into
northern areas w/temps dropping off. Winds have dropped off this
evening below 7 mph across most of northern and western areas
while Bangor and downeast region still seeing 10 mph or so.
Winds look like they will drop off further but are expected to
pick up by Tuesday morning. Some patchy fog is possible
especially in the valleys and along the rivers. The soundings
to point to this for later tonight into early Tuesday morning.
Previous Discussion...
On Tuesday, expect partly to mostly sunny skies across the
north with more in the way of clouds across central and down
east areas. Lows tonight will range from the low to mid 40s
north and mid to upper 40s down east. Highs on Tuesday will
range from the mid to upper 60s north, where sunshine will be
more prevalent, and the lower 60s down east with more in the way
of cloud cover expected.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
Not much chg in thinking regarding the short range from ystdy
with retreating shwrs and cld cvr from the Srn hlf of the FA Tue
ngt allowing for some radiational cooling and below seasonal
norms ovrngt lows by erly Wed morn as winds become lgt and vrbl.
Wed should be ptly to msly sunny and milder, with temps
recovering to near seasonal hi temps. Aft a slightly less cooler
ngt Wed ngt, Thu will be warmer msly across the N hlf of the Rgn
as open ridging alf progresses Ewrd across the Area. With sea
breeze conditions developing ovr much of Downeast and even e
Cntrl ptns of the Rgn by later Thu aftn, Hi temps will show an
inverted S to N pattern, with the warmest hi temps across lower
trrn lctns of the far N. With diffluent flow alf setting up ovr
the Rgn late in the day ahead of slowly advcg upper low/trof
from NY state, sct shwrs with isold tstms should develop msly
across the N and W late Thu aftn, where we introduced low chc
PoPs.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
Models are a little uncertain regarding the track of a sfc low
movg NE from the Sern states. Of all the model solutions, the
opnl 05/12z GFS was the furtherest NW with the track of this
system, which taken on face value attm, would argue or keeping
shwr PoPs all ngt Thu ngt. The other long range models, however,
track the sfc low further SE, with little impact from any
ovrrng rnfl attm ovr our Rgn, suggesting a break in shwrs Thu
ovrngt before shwrs and possible tstms with the passage of the
upper Trof manifest itself by Fri aftn into Fri eve, which for
now, is the scenario we show. We wait highest PoPs with the
upper trof passage in the hi chc category.
Otherwise, other weak s/wvs alf in a WNW to ESE flow alf regime
will keep somewhat unsettled conditions ovr the Rgn this weekend
with intermittent msly day tm shwrs, but certainly nothing that
looks like a day long washout. Hi temps Fri thru Sun will be a
little below seasonal norms due to potential cld cvr and sct
shwrs.
Otherwise, longer range models sharply disagree with the
amplitude and longitudinal placement of a strong upper ridge
alf for erly to mid next week. For now, the majority of models
show Nrn and Cntrl ptns of the Rgn in a warm front band of
cldnss and sct shwrs. Aftwrds, the tmg of when and whether all
of the Rgn will get into the warm sector is uncertain, with the
12z opnl ECMWF the fastest in bringing the warm front thru by
late Mon aftn and most amplified with the upper ridge. Given
that the ECMWF has shown the most continuity with this feature,
we must state that we have low confidence attm with fcst hi
temps on Mon, which is a consensus of all of the longer range
models, which holds off bringing warmer air into the Rgn til mid
week. If the ECMWF is correct, hi temps Mon aftn could be much
warmer than we currently show.
&&
.AVIATION /02Z TUESDAY THROUGH SATURDAY/...
NEAR TERM: VFR conditions can be expected across the
northern terminals through Tuesday. Across the down east
terminals, mainly VFR but a period of MVFR ceilings are expected
late tonight through early Tuesday morning.
SHORT TO LONG TERM: Mainly VFR xpctd for all of our TAF sites
Tue ngt thru Sat with brief MVFR clgs/vsbys possible with
heavier shwrs Fri aftn/erly eve.
&&
.MARINE...
NEAR TERM: A small craft advisory remains in effect for late
tonight through early Wednesday morning.
SHORT TO LONG TERM: Whats left of SCA conditions, msly with wv
hts, should diminish Tues ngt to below SCA by Wed then cont so
thru Thu ngt. SCA wv hts msly with swells are possible ovr our
outer MZs050-051 Fri into Fri ngt with sfc low pres tracking
E of our waters, but given uncertainties with the track and
intensity of the low in this tm frame, certainty is considered
low.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...None.
MARINE...Small Craft Advisory from 4 AM Tuesday to 8 AM EDT Wednesday
for ANZ050>052.
&&
$$
Near Term...Hewitt
Area Forecast Discussion
National Weather Service State College PA
1151 PM EDT Mon Jun 5 2017
.SYNOPSIS...
A slow moving upper low will meander over the region right
through Thursday bringing several more days of cool and
unsettled weather. A weak cold front will cross the region this
weekend before an extended period of much warmer and drier
conditions develops for next week.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
0230Z radar loop showing a broken line of showers and few tstorms
along cold front, extending from just east of KIPT to KJST.
Limited prefrontal instability per SPC mesoanalysis. However,
strong large scale forcing in advance of upper low should
sustain a broken line of showers along front, as it pushes
southeast across the forecast area late this evening. Radar
trends and latest HRRR runs support the highest POPS across the
Middle Susq Valley between 03Z-05Z, with POPs closer to 30 pct
across the southern tier counties.
The front should push east of nearly the entire forecast area
by around 07Z, then will stall out over eastern Pa. Model
soundings support partial clearing skies east of the mountains
by that time, while residual low level moisture ascending the
mountains results in stratus across the Alleghenies. Overnight
lows generally in the 50s will be near to a tad bit above
seasonal norms.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/...
Tuesday will be another dull and cool day. The very slow-moving
upper upper low near the PA/NY border will continue to support
clouds and scattered showers and possible thunderstorms. The
focus for most of the showers/storms will be along inverted
surface trough and associated plume of low level moisture across
eastern and northern Pa.
Blended MOS highs indicate afternoon max temps on the order of
around 10-15 deg below normal.
&&
.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
Little change is expected for both Wednesday and Thursday as
the cold upper low drifts almost right overhead. Look for fairly
numerous afternoon showers with perhaps some isolated low-
topped TSRA.
The coolest temps appear to be Wednesday into Thursday, when
daytime highs may struggle to climb out of the 50s in some
locations of northern and western PA with the upper low and
coolest 850 mb temps right across that part of the state. Max
temps elsewhere throughout the central and southern valleys will
be in the 60s.
A weak front will drop southeast late Friday or Saturday, with
a chance for a few showers and perhaps a thunderstorm.
Temperatures will slowly edge back closer to normal toward
the end of the upcoming week and this weekend.
Went dry for Sunday with sfc cold front expected to move east
of the region and an upper ridge building north into the Ohio
Valley. Guidance continues to suggest that a shortwave moves
through and could initiate a few showers Saturday afternoon.
Stronger indications of a dry Sunday into Monday of next week.
&&
.AVIATION /04Z TUESDAY THROUGH SATURDAY/...
Slow moving line of showers and a few thunderstorms continue to
ease across Central Pennsylvania this evening. With colder
advection behind the front, seeing lower stratus and fog
developing. MVFR to IFR conditions will be across all areas
overnight.
While there will be an improvement in ceilings and visibilities
during Tuesday, upper low combined/triggering afternoon
instability will bring scattered showers and maybe a few
thunderstorms back to the region. Best chances will likely be
across northern areas. At this point have introduced VCSH in
most terminals for the post 18z time frame.
.OUTLOOK...
Wed...VFR/MVFR cigs with showers likely. Isolated thunderstorms.
Thu-Fri...Scattered showers/isolated thunderstorm possible.
Sat...Mainly VFR with scattered showers/thunderstorms.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SYNOPSIS...La Corte
NEAR TERM...Fitzgerald
SHORT TERM...La Corte
LONG TERM...Lambert/Gartner
AVIATION...Jung
Area Forecast Discussion
National Weather Service Dodge City KS
550 PM CDT Mon Jun 5 2017
...Updated aviation section...
.SHORT TERM...(This afternoon through Tuesday)
Issued at 1230 PM CDT Mon Jun 5 2017
Quiet weather across SW KS through tonight, with broad ridging
aloft suppressing convective potential. Green vegetation,
evapotranspiration, and recent rainfall are keeping surface
dewpoints elevated, but the moisture is shallow and there is no
forcing mechanism to incite convection. HRRR model shows numerous
thunderstorms developing along the Colorado Front Range this
afternoon, and subsequently heading eastward across eastern
Colorado. All model guidance shows this activity dissipating
before reaching the CO/KS border through tonight. Forecast is dry
tonight for all zones. After some cumulus this afternoon, tonight
will be clear with lows Tuesday morning ranging from the upper 50s
west to the lower 60s east.
Tuesday...Again mostly sunny and seasonably warm, with highs in
the 80s. A weak flow will continue, with no change in airmass. As
such, winds will remain light, and temperatures will mirror those
observed on Monday.
Scattered thunderstorms will once again redevelop Tuesday
afternoon across the Colorado Front Range, and a bit further east
across eastern Colorado. 12z NAM shows some of these loosely
organized convective complexes at least approaching the NW zones
by Tuesday evening. Models also show possible initiation along a
convergence axis across the eastern zones Tuesday afternoon.
With forcing nebulous, its hard to rely too heavily on particular
model solutions. That said, global models and many CAMs alike all
support the notion of a MCS impacting at the least the NE zones
Tuesday evening/night. Pop grids show an upward trend during this
period, with locally heavy rain likely. The prospects of severe
weather is limited to perhaps marginal hail/wind near the CO/KS
border mainly Tuesday evening.
.LONG TERM...(Tuesday night through Monday)
Issued at 205 PM CDT Mon Jun 5 2017
A typically quiet, early summer synoptic pattern will prevail
through the long term. A couple opportunities for additional
rainfall Tuesday night and again Thursday night, before afternoon
temperatures warm into the 90s over the weekend.
Models are in excellent agreement depicting an MCS propagating
into the NE zones from Nebraska Tuesday night. Pop grids for
showers and thunderstorms have been increased into the likely
category for the northern zones.
Cooled temperatures Wednesday about 2 degrees across the board,
with upper 70s expected behind cool front/MCS outflow boundary.
With the high pressure ridge axis still over the Four Corners,
NW flow aloft may be able to drag a few storms into far western
Kansas Wednesday night.
Another uptick in rainfall coverage expected late Thursday and
early Friday. Models develop scattered convection across eastern
Colorado Thursday afternoon. With the ridge axis persisting over
the spine of the Rockies, NW flow will keep nocturnal MCS
potential alive over SW Kansas through sunrise Friday. 12z ECMWF
in particular latching onto this solution. Pops near 40% offered
by the model blend are justified for now.
Rain chances dwindle on Friday, as high pressure ridge axis noses
in aloft, with western zones near 90.
Strong warming expected over the weekend. Ridge axis and
associated warm plume march onto the plains, with highs well into
the 90s common both Saturday and Sunday. Highs in the upper 90s
expected across the western 1/2 of the CWA Saturday, with ECMWF
increasing 850 mb temperatures above 30C west of Dodge City.
A cold frontal passage is expected to bring an end to the heat
early next week. Early indications are that convective potential
along this boundary will be better east of SW KS, closer to the
I-35 corridor next Monday/Monday night.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 549 PM CDT Mon Jun 5 2017
VFR conditions will prevail tonight with mostly clear skies. Winds
will be from the southeast this evening becoming light and
variable overnight.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 60 89 61 76 / 0 10 50 40
GCK 58 89 60 79 / 0 10 50 30
EHA 57 87 56 81 / 0 30 40 40
LBL 59 87 60 76 / 0 10 40 30
HYS 62 87 60 78 / 0 20 50 40
P28 63 89 61 78 / 0 10 20 20
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Turner
LONG TERM...Turner
AVIATION...Hovorka_42
Area Forecast Discussion...UPDATED
National Weather Service Fort Worth TX
1001 PM CDT Mon Jun 5 2017
.UPDATE...
The main update this evening to the forecast was to adjust PoPs
slightly based on current trends. In addition, I added a mention
of some light/patchy fog down across Central TX. Otherwise, the
remainder of the forecast is in good shape.
Diurnally driven convection has diminished this evening. The upper
low which was responsible for assisting in the development of
afternoon showers and thunderstorms has finally shifted towards
the east and southeast. RAP mesoanalysis in conjunction with low
and mid level water vapor imagery indicates a fetch of drier air
was spilling southward across the Ozarks and into portions of
Northern Oklahoma ahead of a broad trough across the Great Lakes
region. As this trough continues to dive southward, this drier air
should as well. With that in mind, I`ve limited the chance for
rain/storms down across Central TX through at least midnight where
the airmass will still remain moist. In addition, the low
temperature-dewpoint temperature spreads coupled with calm winds
across Central TX should support the development of some
light/patchy fog. Widespread dense fog is not anticipated at this
time, but a few low lying spots and areas near bodies of water
could experience visibility near or just below 1 mile in spots.
Farther north, the drier air coupled with mixing at the top of the
PBL should limit fog development.
Outside of these changes, the forecast looks to be in fine shape.
Updated products have been transmitted.
24-Bain
&&
.AVIATION... /Issued 651 PM CDT Mon Jun 5 2017/
Scattered showers and thunderstorms will continue to wane as
sunset approaches. Expect VFR conditions through the evening and
much of the overnight hours. Some MVFR ceilings should develop
around 09z and hang into until late morning (16z) with VFR
conditions thereafter. Northerly winds around 10 knots will
prevail.
58
&&
.SHORT TERM... /Issued 317 PM CDT Mon Jun 5 2017/
Scattered showers and thunderstorms continue this afternoon across
much of North Texas. Aided by peak daytime heating, most of the
activity will reach maximum intensity over the next couple of
hours, then begin to diminish in coverage through the evening
hours. Water vapor imagery shows the upper trough overhead with
the main lobe of vorticity now moving off of the Texas coast and
out into the Gulf of Mexico. Weak large scale forcing for ascent
will continue through the evening before stronger height rises and
drier air begin to move into the region and this will bring an end
to the higher rain chances for several days to come.
In the immediate short term, the main threat with this activity
will continue to be locally heavy rainfall and frequent cloud to
ground lightning. With slightly stronger flow aloft, these storms
do seem to be moving at a little faster pace, so despite the high
rainfall rates, they shouldn`t sit in any one location for very
long. As has also been the case over the last few days, there will
continue to be an isolated downburst threat with the strongest
cells.
With precipitation coming to an end later this evening, low level
moisture will still linger for a while until drier air can really
work into the region. This may result in an expansive area of low
cloud cover again late tonight into Tuesday morning. These clouds
should erode fairly quickly on Tuesday.
Dunn
&&
.LONG TERM... /Issued 317 PM CDT Mon Jun 5 2017/
Thunderstorm chances will be considerably lower for the next few
days due to the departure of the upper trough that has brought us
multiple days of beneficial rainfall. On Tuesday afternoon, we
will remain vaguely under influence of a low-level trough axis
which will be draped through southern Texas. With a weakness aloft
still in place across our eastern and southern zones, have
included some very low shower/storm chances in these areas for
Tuesday afternoon. With large-scale subsidence starting to take
over, any activity should stay pretty isolated, much more so than
the past few days. Despite the northerly winds and weak cold
advection working into the area, temperatures should still climb
into the upper 80s and low 90s for many locations owing to a
decrease in cloud cover during the afternoon hours.
An upper ridge will build to our west during the middle of the
week leading to warm/humid conditions. A muggy summertime feel
should exist since surface dewpoints won`t be scoured out and
afternoon humidity values will generally hover around 35-50%.
Later Wednesday evening, a surface high will nudge southward
into the Mississippi Valley which will push an ill-defined
backdoor cold front into our northeastern zones. This won`t be
very noticeable other than some slightly drier air moving into
the area which should allow low temperatures to fall a couple
degrees lower on Thursday morning. This will be short-lived
however, as winds will return to the south later Thursday and
begin to slowly pull moisture back northward.
On Thursday night and Friday morning, we`ll be keeping an eye on a
cluster of storms that should develop across West TX that could
be steered into our northwestern zones. Have introduced some low
PoPs for this scenario due to the consistent appearance in recent
model runs. However, this activity should be weakening
dramatically by the time it reaches our forecast area as it
outruns the upper disturbance responsible for it`s initiation, not
to mention low-level wind fields and moisture transport are
expected to be weaker over the eastern half of the state. A
similar potential exists on Saturday morning, too, although there
is more disagreement among model solutions in this possibility at
this time. Temperatures will be near normal through the rest of
the forecast period with hot and humid conditions continuing into
early next week.
-Stalley
&&
.PRELIMINARY POINT TEMPS/POPS...
Dallas-Ft. Worth 70 91 67 90 67 / 10 5 0 5 0
Waco 69 89 66 89 65 / 20 5 0 5 0
Paris 67 87 65 85 61 / 10 10 0 5 0
Denton 67 90 64 88 64 / 10 5 0 5 5
McKinney 68 89 65 87 64 / 10 5 0 5 0
Dallas 70 91 69 90 67 / 10 5 0 5 0
Terrell 68 88 66 87 63 / 10 10 0 5 0
Corsicana 70 88 67 88 65 / 10 10 0 5 0
Temple 68 87 66 89 65 / 20 10 0 5 0
Mineral Wells 66 89 64 88 63 / 10 5 0 5 10
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
24/58
Area Forecast Discussion
National Weather Service Goodland KS
513 PM MDT Mon Jun 5 2017
.SHORT TERM...(Tonight through Tuesday)
Issued at 510 PM MDT Mon Jun 5 2017
Shower and thunderstorm activity is expected to move into parts of
far eastern Colorado after 00z and continue through about midnight.
Operational and experimental HRRR showing outflow winds to 55 mph
along with some locally heavy rainfall. Have added the gusty winds
into the grids. After midnight activity should be done for the most
part. Low temperatures will be above normal with mid 50s to low 60s.
For Tuesday we should have dry weather across the area in the
morning with winds under 10 mph. Mid and high clouds cover much of
the area creating a partly sunny to mostly cloudy sky. During the
afternoon hours precipitation chances increase pretty quickly as a
very moist airmass is triggered by an approaching weather
disturbance from the northwest. Severe weather is possible along
with the threat of heavy rainfall and possible flash flooding.
Afternoon temperatures are expected to reach the upper 70s to low
80s in far eastern Colorado with low to upper 80s across the rest of
the area.
.LONG TERM...(Tuesday night through Monday)
Issued at 206 PM MDT Mon Jun 5 2017
Tuesday night: Shortwave trough is still expected pass near or over
our CWA. The main upper trough is well north, but models continue to
show a deepening shortwave moving our of the northwest then taking a
southerly dive near our CWA through Tuesday night. A weak cold front
approached the region later Tuesday night, with a prefrontal trough
acting as a focus for initiation in the evening. Most models are
showing decent coverage, but NAM/ARW/NMM are hinting at a possible
thunderstorm cluster or clusters forming and tracking across our
east during the evening and overnight. An anomalously moist air mass
is shown to build across our east with PWAT values possibly within
the 99th percentile (near record values compared to area soundings).
There should be enough instabilty (tall/skinny profiles) to support
thunderstorms, but with weak shear/slow storm motions this will be
more of a set up for heavy rain and possible flash flooding.
Depending on expected coverage we may need to consider a Flash Flood
Watch, but I wanted to hold off with time before this event possibly
unfolds.
Wednesday-Wednesday night: Models try to hold onto light
showers/isolated thunderstorms all day Wednesday with a brief
clearing possible midday. Forcing should tend to decrease, however
there will still be enough lift particularly along stationary front
in our west and elevated baroclinic zone a little further east.
With clearing we may see instabilty increase would could support
better thunderstorm chances in the afternoon/evening before
subsidence and ridging spread east Wednesday night. Temps will be
tricky with post frontal air mass (cooler) and cloud cover. Models
may be a touch warm, but with higher uncertainty I only trended
highs down a little.
Thursday-Monday: Ridging transitions east followed followed by a
long fetch of SW flow this weekend. Moisture profiles show
increasing spread in Td depressions as much drier air follows this
change in pattern. Ridge axis may still be just far enough west to
allow another shortwave trough to kick off showers/thunderstorms
Thursday afternoon/Thursday night along surface trough axis.
Otherwise, the rest of these periods should be dry. Deep southwest
flow will develop over our CWA as upper trough deepens in the
western US. Strong WAA will support hot temperatures well above
normal this weekend. There is still spread due to timing of a
possible frontal passage, but confidence is high enough to hold
temps up at least through Saturday (less confidence beyond). If GFS
temp profiles and good mixing occur we could have many location in
the upper 90s Saturday, possibly 100 at a few warmer spots. ECMWF
is a little "lower".
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 510 PM MDT Mon Jun 5 2017
Storms in northeast Colorado this afternoon are expected to
dissipate this evening with loss of surface heating and not impact
either terminal. So, VFR expected at both KGLD and KMCK through
tonight and tomorrow morning. However, scattered thunderstorms
will develop across the region Tuesday afternoon with the approach
of an upper level disturbance and associated cold front. KMCK will
have an earlier start so added a mention for the afternoon, but
storms may hold off until around 00z at KGLD so left out a mention
for now.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...99
LONG TERM...DR
AVIATION...024
AREA FORECAST DISCUSSION
National Weather Service Jackson KY
1050 PM EDT Mon Jun 5 2017
.UPDATE...
Issued at 1050 PM EDT MON JUN 5 2017
Convection is continuing to dissipate at a fast pace as we lose
instability late in the evening, and the line moves into a much
more stable/worked over airmass. All thunder has diminished so
went ahead and removed this from the forecast grids. Also
diminished the precip grids faster, with all rain out of the
forecast by 6Z. Even then this may be an hour or two too long
based on the latest radar trends. All grids have been published
and sent to NDFD/web. A new forecast package including an updated
HWO have also been sent.
UPDATE Issued at 937 PM EDT MON JUN 5 2017
Forecast was still in fairly good shape. Just made some minor
adjustments to move the axis of precipitation slightly farther
southward to match up better with the existing line. Still
expecting the line to continue its diminishing trend over the next
couple of hours as we get farther into the overnight and the line
moves into an area of the state with little instability left. Also
went ahead and updated the near term grids to make sure the temps,
dew points, and winds were on track with the current observations.
All changes were published and sent to NDFD/web. Also sent out a
new zone package to remove late afternoon wording and reflect the
latest changes in POPs/weather. A new HWO was also sent out to
remove potential severe storm and flooding wording.
UPDATE Issued at 744 PM EDT MON JUN 5 2017
Made several more tweeks to the pop/weather forecast based on the
latest radar trends. Line of showers and thunderstorms continues
to sink southward across northern KY ahead of a cold front. These
seemed to have lost some momentum over the last half an hour or so
as they continue to move into east central and south east KY,
areas that have already been worked over with falling dew points
and temps. Kept likely pops in place for the next 1 to 2 hours,
but expect things to continue falling apart as we head further
into the evening. All changes have been published and sent to
NDFD/web.
UPDATE Issued at 539 PM EDT MON JUN 5 2017
Continuing to track precip across the region. The rain that
covered most of southern KY has nearly dissipated and moved to
our SE as cooler air continues to push into the region. Continued
to taper off pops in this location a bit faster, with only slight
to low end chances for the rest of the evening. Two lines are
continuing to surge southward ahead of the cold front to our
north. The first of these lines is currently impacting our
northern counties, so beefed up pops here and show the southward
movement of this line over the next few hours. The more northward
line is a little bit more uncertain. Most of north-central KY has
not been worked over yet and as a result has a much more unstable
and supportive airmass in place. The question is as the line
pushes southward and moves across our northern CWA which has
already been very much worked over, will it break apart over us
and dive southwest towards the better airmass. Will continue to
monitor in case this line results in any changes to the updated
forecast again.
As part of this update, also loaded in the latest observations for
temps, dew points, and winds to make sure they were up to date
with the current observations. All grids have been published and
sent to NDFD/web. A new forecast package was also sent out.
&&
.SHORT TERM...(This evening through Tuesday night)
Issued at 345 PM EDT MON JUN 5 2017
As of mid to late afternoon, an upper level low was moving through
the Great Lakes region with another upper low over the southern
Plains into the western Gulf of Mexico. A lead shortwave trough
that helped bring the steadier showers across much of the area
this morning into the afternoon is shifting into the Appalachians
with the main 500 mb trough axis lingering to the west. At the
surface, a cold front extended southwest into the Ohio Valley from
Upstate NY. Scattered to numerous convection has developed along
with boundary over OH and southeast IN. Winds aloft have already
shifted to the north and northwest behind the lead shortwave with
the cold front lingering to the north.
The cold front is dropping toward the OH River with additional
convection along and in advance of it. Some of this convection
has been been slow moving north and northeast of the area with
heavy rain and some gusty winds. Ahead of the boundary a narrow
corridor of 1500 to as much as 2500 j/kg. SBCAPE has developed
and recent RAP guidance suggests SBCAPE of 1500 j/kg or higher
through early this evening developing within some clearing or
thinner overcast behind the deeper moisture and steadier
precipitation. The cold front should move into the region near
sunset and depart to the south and southeast overnight. Surface
high pressure over the Great Lakes will build into the region
behind the boundary and dominate the weather through the end of
the period.
Some locally heavy rain is still possible in any location that
receives multiple thunderstorms through this evening and DCAPE
levels could reach 800 j/kg along and north of the Mtn Parkway
and thus the strongest cells could produce gusty to locally
damaging winds. The threat of widespread heavy rain has ended
though, including in the Cumberland Valley where a Flash Flood
Watch had been in effect. The Flash Flood Watch has been cancelled
early since the steadier and threat of widespread heavy rain has
ended. Through the evening, the steadier heavy rain has ended and
at least one if not two bands or broken lines of showers and
thunderstorms will be possible along and in advance of the cold
front. This activity should diminish and weaken around or after
sunset, with the threat of convection ending overnight.
High pressure building into the area will bring a decrease in
clouds in the north late tonight and across the entire area on
Tuesday. Clouds should increase again by late Tuesday night as the
upper low meanders to southwest PA by the end of the period and
brings an increase in low and mid clouds. Any clearing will lead
to a threat of valley fog tonight and in some valleys on Tuesday
night as well due to wet ground front recent precipitation. Temperatures
will average below normal behind the front.
.LONG TERM...(Wednesday through Monday)
Issued at 256 PM EDT MON JUN 5 2017
At the start of the period an upper level low will be over PA. The
low is forecast to drift southwest through Thursday morning before
lifting northeast from Thursday into Thursday night. Low level lapse
rates will increase with the approach of the colder mid level
temperatures associated with the upper level low, especially over
the northeast and eastern part of the forecast area. Freezing levels
may even drop below 8K feet by Thursday morning in the eastern part
of the area. Enough instability should exist both Wednesday and
Thursday afternoons for shower chances, especially on Thursday. Have
followed SPC`s day three outlook and left out thunder chances for
Wednesday, which is in agreement with neighboring offices. However
overall convective chances look best on Thursday, and would not be
surprised if some thunder occurs Thursday afternoon. If
thunderstorms develop would not be surprised to see some small hail
Thursday afternoon.
The upper level low will lift out as a short wave trough moves
across the Great Lakes from Thursday into Friday. This trough will
bring an associated cold front southeast into the northern OH valley,
but this looks to wash out before it ever gets to our area. Upper
level ridging will build across the OH valley over the weekend with
temperatures warming significantly. Moisture increases in the
southern part of the forecast area by early next week with a return
of shower and thunderstorm chances.
The upper level low will result in below normal temperatures at the
start of the forecast period, with ridging late in the forecast
period bringing above normal temperatures.
&&
.AVIATION...(For the 18Z TAFS through 18Z Tuesday afternoon)
ISSUED AT 215 PM EDT MON JUN 5 2017
While showers that impacted much of southeast KY during the day
have now dissipated, focus turns to a line of showers and
thunderstorms dropping southward across northern KY ahead of an
approaching cold front. These storms are continuing to show a
weakening trend as we head into the evening, due in part to loss
of daytime heat/instability, and the fact that they are pushing
into areas that have already been worked over by earlier rainfall.
As such, don`t expect them to have much impact as they pass
through KSYM and KSJS within the next hour, possibly reaching KJKL
just after. They should fall apart all together before reaching
KSME and KLOZ. Given the large amount of lingering moisture in the
air, and drier/cooler air moving in aloft overnight, do expect
there to be a good potential for fog set up at all TAF sites. Kept
with predominate LIFR conditions during the late night, though
each TAF site could react slightly differently. Will update
accordingly as fog sets up. This fog should lift and eventually
dissipate during the morning hours tomorrow, with a period of
MVFR conditions expected. High pressure, light winds, and VFR
conditions will then prevail for the remainder of the day.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JMW
SHORT TERM...JP
LONG TERM...SBH
AVIATION...JMW
Area Forecast Discussion...UPDATED
National Weather Service North Platte NE
656 PM CDT Mon Jun 5 2017
.SHORT TERM...(This evening through Tuesday)
Issued at 342 PM CDT Mon Jun 5 2017
The forecast follows a blend of the SREF and HRRR/RAP models this
evening. The SREF was the basis for thunderstorm chances Tuesday.
The HRRR will form a MCS this evening with its genesis on the Black
Hills and Laramie Range. The MCS, if it develops, would likely move
east through Srn SD/Nrn Neb. K-indices in the HRRR and RAP models
across Ncntl Neb are very high, around 40C and precipitable water
increases to over 1 inch. A modest 30kt low level jet forms tonight
aimed at the developing convection. Severe weather potential is low
with bulk shear 30kt or lower. The cold pool should dominate and
wind gusts to around 50 mph would appear to be the primary hazard.
One problem with the forecast is that if the HRRR is correct then
outflow will sweep much of the instability south and east of the
forecast area leaving rain chances Tuesday less than likely as
currently forecast. The HRRR experimental model which runs out to 36
hours shows this. So the forecast is a hedge of the slower SREF and
the ambitious HRRR model.
Nonetheless, the SREF shows precipitable water increasing to 1.25
inches or higher Tuesday afternoon. At 21z, an inverted h850mb trof
stretches from Ogallala to Ainsworth and this is expected to be the
focus for thunderstorm development. The other models have been
consistent with this feature over the past few days.
The temperature forecast tonight and Tuesday is a consensus of the
guidance and deterministic models plus bias correction. The latest
forecast suggests cool temperatures across Northwest Nebraska
Tuesday as a result of the thunderstorms tonight and a residual cold
pool Tuesday.
.LONG TERM...(Tuesday night through Monday)
Issued at 342 PM CDT Mon Jun 5 2017
High pressure ridging will remain nearly stationary from the desert
southwest into the Rockies though the end of the week. This
generates weak northwest flow aloft on the eastern periphery of the
ridge across our area. Surface flow will mostly be south to
southeast which should maintain at least mid 50s dew points through
the end of the week. Afternoon heating will lead to widely scattered
showers and thunderstorms just about each afternoon this week as
there will be little capping aloft. The best chance continues to be
Tuesday afternoon when a weak shortwave disturbance slides southeast
across the region.
By Saturday a large upper level low pressure system should be
digging into the Pacific northwest. This will nudge the upper level
ridging east over our area. With the ridge expect 700mb temperatures
to rise in the mid to possibly upper teens Celsius, which will
create a stout capping inversion. So the weekend looks mainly dry
despite increasing humidity with the flow off a wide open Gulf of
Mexico.
Temperatures will be near average Tuesday through Thursday, with
increased cloud cover and possible rain (especially Tuesday). Then
by weeks end a big warm up as the ridging aloft spreads across the
central plains. Highs in at least the upper 80s seem likely next
weekend.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 647 PM CDT Mon Jun 5 2017
A line of strong to sever storms is continues along a line from
the Black Hills through the Nebraska Panhandle into eastern
Colorado. These stroms will move east over night into western
Nebraska. Storms will continue over northern Nebraska through the
early morning on Tuesday and then redevelop along a cold front
moving southeast across the area through the day on Tuesday. Have
carried VCTS at KVTN after 06/09z and after 06/16z at KLBF. Front
will move slow through the day with thunderstorms lingering over
western Nebraska through the early evening.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SHORT TERM...CDC
LONG TERM...Taylor
AVIATION...Power
Area Forecast Discussion...UPDATED
National Weather Service Little Rock AR
608 PM CDT Mon Jun 5 2017
.DISCUSSION...
Updated to include the 00Z aviation discussion below...
&&
.AVIATION...
Some isolated SHRA and a few TSRA will remain possible this
evening...with mainly some isolated SHRA overnight at central/SRN
terminals. Some patchy fog and MVFR CIGS will be possible during
the overnight period...though a cold front dropping south across
MO this evening will push through the state by Tue afternoon. This
will bring VFR conditions to the state.
&&
.PREV DISCUSSION...(ISSUED 308 PM CDT Mon Jun 5 2017)
SHORT TERM...Today Through Wednesday
Showers and thunderstorms will continue to move across the state
as a low pressure system in the ArkLaTex region begins to
accelerate eastward with the help of a kicker low swinging through
the Great Lakes region. Upstream of the low is a somewhat
amplified ridge which will influence our weather in Arkansas the
next few days.
For the rest of day and tonight- 12z LZK sounding showed pwat of
1.87 which is just shy of record for the date and in the 90th
percentile moving average. With such a warm airmass in place, warm
rain processes have helped these showers become fairly efficient
rainfall producers. While most areas will receive less than a
quarter inch of rainfall, a few spots may see significantly more
in any spots in which an axis of precipitation may pivot.
A bit of model disagreement in the short/near term. For the near
term, have chosen to go near the HRRR which has handled the cloud
cover / lack of diurnal heating much better. However, the HRRR has
much drier mid-level air moving into the region overnight, while
most other models keep the boundary layer much more moist. If the
latter profile comes to fruition, areas of drizzle and fog may
form in the morning. Have kept light rain in the grids into the
morning, but have decided to hold off on fog for now.
The aforementioned ridge of high will slowly progress eastward
and flatten out. With surface high building in to the north, a
cold front will push through the state on Tuesday. By Tuesday
evening, much drier air will have filtered into the state.
Temperatures will be below average Wednesday morning... with lows
in within a few degrees of 60. Highs will likely be below as
well... though dry air and very efficient heating through
insolation may help temps reach near normal.
LONG TERM...Wednesday Night Through Monday night...
Should be entering a period of dry weather during the extended
term, for the most part. Area will be under an upper level ridge
aloft, with surface high pressure building in.
As the surface high slides to the east over the weekend, a return
southerly flow will set up, bringing surface moisture levels up
again, and more afternoon clouds. By Monday some models are showing
a weak shortwave transitioning thru the ridge, and this may be
enough to trigger some afternoon and evening thunderstorms, but at
the moment I have the POPs quite low.
&&
.LZK Watches/Warnings/Advisories...NONE.
&&
$$
Aviation...62
Area Forecast Discussion
National Weather Service Midland/Odessa TX
450 PM CDT Mon Jun 5 2017
.DISCUSSION...
See 00Z Aviation Discussion below.
&&
.AVIATION...
VFR conditions should prevail next 24 hours, in light easterly
flow. The NAM, ARW, and HRRR remain consistent in bringing a batch
of convection into SE NM overnight in NW flow aloft, so we`ve
mentioned them KCNM/KHOB. Otherwise, the AMS remains juicy,
w/forecast soundings hinting at stratus developing into KMAF Tue
morning. We`ll keep it VFR for now. Convective temps will be
reached early, spawning a cu field w/bases 3.5-4.5 kft agl.
&&
.PREV DISCUSSION... /issued 203 PM CDT Mon Jun 5 2017/
DISCUSSION...
A mid level ridge axis will remain just w of the central NM mtns
leaving the CWFA within NW-N flow aloft thru Thur, a general
favored flow for nocturnal storms for areas n of I-20. In this
particular case the fetch of the NW component is not very long and
thus a little more difficult for definitive shrtwv trofs to track
thru the flow. Leaving the main impetus for driving storms the
diurnal heating cycle/gathering instability on the e slopes or in
the adjacent plains. Late tonight and Tue night storms will have a
chance to track into SE NM/far NW PB with stronger storms on Tue
night. Wed night SE NM/Upper Trans Pecos are the favored areas,
less signal Thur night? In the meantime, NW flow does not favor
the development of the low level thermal ridge and thus high temps
will mostly remain seasonal thru Thur. Mid level ridge axis will
finally move e on Fri pushing high temps above normal, probably
well above across SE NM/W PB, with drier air through Monday. We
down played PoPs from Superblend on Friday? Sat-Mon 7h temps of
13- 15C support hot/dry conditions.
&&
.PRELIMINARY POINT TEMPS/POPS...
Big Spring 65 88 66 89 / 10 10 10 10
Carlsbad 65 91 65 92 / 20 20 40 10
Dryden 69 92 70 92 / 10 10 10 10
Fort Stockton 66 90 67 92 / 10 10 20 10
Guadalupe Pass 63 84 62 86 / 10 20 40 20
Hobbs 63 87 62 88 / 10 10 40 10
Marfa 59 87 59 87 / 10 10 30 10
Midland Intl Airport 66 89 66 91 / 10 10 20 10
Odessa 66 89 66 90 / 10 10 20 10
Wink 66 92 67 93 / 10 10 30 10
&&
.MAF WATCHES/WARNINGS/ADVISORIES...
NM...None.
TX...None.
&&
$$
44/80/44
Area Forecast Discussion
National Weather Service Miami FL
854 PM EDT Mon Jun 5 2017
.UPDATE...
The 00Z MFL sounding sampled a very moist air mass with
precipitable water near 2.2 inches and sufficient CAPE for deep
moist convection. The sounding and KAMX VAD Wind Profile are also
showing an increase in low level shear and helicity over time. A
boundary between rain-cooled air to the northwest and unstable
air to the southeast was draped across parts of Broward and
Miami-Dade County and has been the focus for mini-supercell
thunderstorms which produced one tornado earlier over western
Broward metro. Low level helicity is increasing with time but we
are now going into nocturnal cooling, so an isolated brief tornado
or two cannot be ruled out overnight, but low level lapse rates
will be poor so the overall threat should be limited.
The aforementioned boundary has also been the focus for the
heaviest rain with radar-indicated amounts in excess of 3 inches
in parts of west metro Broward. Numerous showers and
thunderstorms are developing over the southeast coastal Metro,
southern Miami-Dade and back into the nearshore Gulf waters as of
845 pm. A short-fuse flood watch had been considered for parts of
the metro area, particularly Broward County, but the threat area
is likely enough to be contained in time and space that it can be
handled with warnings if necessary.
Late tonight, CAMs such as the HRRR indicate the focus of
activity may shift more toward the Lake Okeechobee region with a
respite possible for the southern Peninsula late. Forecast POPs
and QPF were updated with this thinking, otherwise the forecast is
unchanged beyond tonight.
&&
.PREV DISCUSSION... /issued 749 PM EDT Mon Jun 5 2017/
AVIATION...
Periods of showers and thunderstorms will continue all terminals
through Tuesday. In the near term, strongest activity early this
evening will affect FLL/FXE with increasing activity spreading
north from the Keys toward MIA/OPF/TMB later this evening. Any
TSRA will be accompanied by periods of IFR restrictions, which
will be handled by amendments and tempo groups. During dry
periods VFR conditions prevail. Winds will be light and mostly
driven by thunderstorm outflow tonight, but will increase out of
the SSW and become gusty after sunrise Tuesday.
PREV DISCUSSION... /issued 348 PM EDT Mon Jun 5 2017/
DISCUSSION...
At mid-afternoon, a thermal boundary extended from Kendall to
Chokoloskee and was sinking slowly south, being reinforced by rain
cooled air from convection to the north. South of the boundary,
thin cloud cover has allowed temperatures to reach the upper 80s
with dewpoints in the upper 70s, yielding MLCAPE values near 2500
J/kg. Expect showers and thunderstorms are likely to continue to
form along this boundary for much of the afternoon and evening and
move northeastward, which may lead to training of echoes over the
same areas. Trends today have been for deep convective showers
with limited lightning, which is a clue warm rain processes are
dominating and rainfall rates are quite efficient.
A complex system of upper disturbances over the Gulf is readily
apparent in GOES-16 water vapor imagery. In advance of this slow-
moving system, southerly flow in the boundary layer has tapped deep
tropical moisture from the Caribbean, and the remnant moisture from
former east Pacific Tropical Storm Beatriz is also entrained in the
mid level southwesterlies. Model forecast precipitable water
increases into the 2.2 to 2.4 inch range tonight into Tuesday
which seems reasonable with this setup.
As the system of shortwave troughs approaches, mesoscale and
synoptic models show gradually strengthening wind fields over the
area tonight and Tuesday morning, enhancing the potential for
strong winds to be brought to the surface in any convection.
Additionally, the NAM-12 and most convection-allowing models
increase the 0-1 km storm-relative helicity into the 150-200 m2/s2
range overnight into Tuesday. A few thunderstorms with transient
supercell structure have already been observed this afternoon and
this may again be observed at any time over the next couple of
days. Limiting factors will be the chance for widespread cloud
cover and convection to limit instability, and the strongest shear
profiles may be overnight during the nocturnal minimum in
instability. A marginal risk of severe thunderstorms from SPC is
in place tonight through Wednesday.
The Gulf system is very slow to approach with the rich tropical
moisture locked in place over the area through Thursday.
Tropospheric wind profiles will become increasingly favorable for
training of heavy showers and thunderstorms Tuesday and Wednesday.
This pattern is favorable for some spots to receive a lot of
rain, but at this point it`s still too soon to pin down the most
favored timing and areas at risk for flooding. For now will defer
on issuance of a flood watch though one may be required later.
Winds will also be gusty during the day Tuesday and Wednesday out
of the S/SW due to the tight local pressure gradient.
From Thursday night into Friday, the Gulf system finally moves
across central Florida and up the southeast coast, allowing a
front to approach the northwest part of our area. The boundary may
briefly slip across the Lake Okeechobee region for awhile Friday
drying things off, but all indications from the medium range
models are the boundary will wash out before crossing the entire
area with tropical moisture re-establishing by the weekend.
MARINE...
Winds will steadily increase to moderate to locally fresh levels
tonight and Tuesday over the local waters as a storm system
approaches from the west. Sustained winds 20-25 knots appear
likely tomorrow in the Gulf Waters off Collier County and a Small
Craft Advisory will be in effect. Elsewhere small craft will need
to exercise caution. Scattered thunderstorms will also be a
threat, locally increasing winds and seas.
&&
.PRELIMINARY POINT TEMPS/POPS...
West Palm Beach 77 89 75 88 / 80 70 40 70
Fort Lauderdale 77 90 77 89 / 90 60 50 60
Miami 77 90 78 89 / 80 60 50 60
Naples 75 87 79 85 / 90 80 60 80
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...None.
AM...None.
GM...Small Craft Advisory from 5 AM to 8 PM EDT Tuesday for GMZ656-
676.
&&
UPDATE...22/KS
DISCUSSION...22/KS
MARINE...22/KS
AVIATION...22/KS
Area Forecast Discussion
National Weather Service Melbourne FL
910 PM EDT Mon Jun 5 2017
.UPDATE...
...LOCALLY HEAVY RAIN INTO MID WEEK WITH A MARGINAL RISK FOR SEVERE
STORMS TUESDAY AND WEDNESDAY...
Tonight-Tuesday...Interesting pattern for early in the wet season
with a mid level trough and weak surface low approaching from the
Gulf of Mexico. This system will lift abundant moisture out of the
tropics and produce a local heavy rain threat. Additionally, deep
layer winds will increase and lead to some strong storms. If we can
eke out a little more daytime heating than we had today, isolated
severe storms will also be possible.
For the overnight into early Tue morning...We`ve seen several
different scenarios from the HRRR model since afternoon. All point
to a non-standard situation with a chance of showers and storms
through the night and into the morning commute. The GFS shows some
upper diffluent flow, which is supporting convection in the
southeast Gulf, pushing in our general direction as the trough
aloft digs into the western Gulf. With precipitable water forecast
2.1 to 2.3 inches, it would not be surprising to see another round
of convection overspread much of the area overnight and linger a
little past sunrise. Therefore will keep likely POPs after midnight.
The greatest chance for locally heavy rainfall should be around
Okeechobee to the Treasure Coast.
Would expect a bit of a lull once that convection and debris
cloudiness lifts away Tue morning, but the very high moisture should
lead to a quick redevelopment of widespread showers and scattered
storms by late morning or early afternoon.
&&
.AVIATION...
A cloudy period on tap through Tue. There will be a chance of
showers and storms overnight into early Tue. Some MVFR to IFR could
occur locally with this activity. Due to a very moist atmosphere,
showers and storms should redevelop quickly late Tue morning or
early in the afternoon. Cells will be moving more quickly so in
addition to brief torrential downpours with IFR conditions, strong
wind gusts 35 to 40 knots will be possible.
&&
.MARINE...
Tonight-Tuesday...An area of low pressure is forecast to form over
the northern Gulf of Mexico near the Mississippi delta region. This
will start to tighten the pressure gradient late tonight so will
mention an exercise caution statement offshore from about Cape
Canaveral northward. The GFS shows south/southwest winds near 20
knots on Tue, but a more substantial increase of 20-25 knots is
indicated Tue night through Wed, with Small Craft Advisory
conditions becoming probable by that time.
Of course, the weather will not be good the next few days either,
with periods of showers and thunderstorms occurring. Some stronger
and quicker moving storms will occur Tue, which prompt Special
Marine Warnings for 35-40 knot wind gusts.
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...None.
AM...None.
&&
$$
FORECASTS...Lascody
IMPACT WX...Sharp
Area Forecast Discussion
National Weather Service Mount Holly NJ
941 PM EDT Mon Jun 5 2017
.SYNOPSIS...
Low pressure will continue to move northeast away from Delmarva
and out to sea tonight. Another weak low is expected to drop
southward across our area on Tuesday. High pressure should build
toward our region from the north and west on Wednesday and
Thursday as another area of low pressure passes off the North
Carolina coast. High pressure is anticipated to work its way
from the southeastern states on Friday to the western North
Atlantic for the weekend and next Monday.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
The primary concerns tonight continue to be the potential for
locally heavy rainfall over the Poconos, Lehigh Valley, and
northern NJ in association with any thunderstorms that make it
into our region, and patchy fog.
Any flooding across the aforementioned area should be limited
to urban/poor drainage. There is the potential for patchy fog
to develop across the entire area.
Previous Discussion...
A plethora of concerns exists for the forecast overnight. The
first is a shield of light rain with embedded convection
occurring generally along and south of I-76 this afternoon.
Although most precipitation totals have been light (generally
around or under a third of an inch), isolated convective cells
are producing substantially higher precipitation totals (up to a
third of an inch in about fifteen minutes at KMIV recently).
High-resolution guidance is strongly suggestive of isolated
swaths of considerably higher rainfall totals (1+ inch) within
the main shield of precipitation, and the character of the
precipitation is providing support for this scenario (though not
to the widespread degree of most of the simulations). I bit the
bullet earlier this afternoon, and increased totals
considerably in southern Delaware and far southeast New Jersey.
Most guidance suggests this precipitation winding down early
this evening as the attendant surface low in the southern Mid-
Atlantic moves offshore. Output such as the 12Z NAM and several
of the HRRR simulations look considerably overdone (and have
been so far), so tempered QPF with a healthy dose of drier
simulations (e.g., the RGEM). Nevertheless, some isolated urban
/poor-drainage nuisance flooding can be expected, especially in
far southeast New Jersey.
The second concern is convection northwest of the Fall Line
this evening. Ahead of a very slow-moving cold front in southern
New York and northwest Pennsylvania, pockets of insolation have
increased instability sufficiently to generate scattered
convection in much of New York and adjacent northern/western
Pennsylvania this afternoon. Generally, this convection has
stayed well to the northwest of the CWA, but a few storms have
occasionally initiated in the Poconos, with healthy rain rates
as they reach peak intensity. Particularly concerning are some
of the recent HRRR simulations, which develop several slow-
moving convective cells that have at least some propensity for
training (given the parallel orientation of the upper- level
flow to the surface boundary). Though most (and the strongest)
convection looks to stay northwest of the area through the
evening, some convection will likely enter into the Poconos and
adjacent Lehigh Valley this evening. As such, think heavy rain
is a possibility here, and this will be watched closely.
How much convection enters the rest of the CWA late this
evening is yet another concern. Here, there seems to be decent
agreement that most convection will remain confined to areas
northwest of the Fall Line through late evening before nocturnal
stabilization promotes the dissipation of most of the storms.
However, the 12Z NAM Nest suggests some convection may persist
overnight along and west of the Delaware River, and with cold
air aloft and the approach of a potent vort max into the
northern Mid-Atlantic late tonight -- kept PoPs all night long
in the area (though generally slight to low chance late
tonight). For now, kept thunder out of the grids after 2 am, but
model soundings do show some marginal (elevated) instability,
so a rumble of thunder cannot be ruled out.
Final concern is potential for some patchy fog. With a warm
front struggling to exit the area this afternoon and the
aforementioned surface low moving off the coast tonight, there
will be a strong northeast low-level fetch just off the surface
developing in northern/central New Jersey. As such, think there
is some potential for drizzle/fog in these areas (and
potentially farther west into adjacent eastern Pennsylvania)
during the overnight hours. Included patchy fog in the grids
generally north of I-195, though this may not be far enough
south/west if some of the guidance is to be believed.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/...
The upper-level low plaguing southeast Canada and the
northeastern U.S. will make a shift eastward overnight into
Tuesday but will eventually stall as (1) an upstream
perturbation digs rapidly southward into the Appalachians and
(2) downstream ridging prevents the low from ejecting eastward.
This will stretch the vorticity in a WSW-ENE fashion from the
Mid-Atlantic to the Canadian Maritimes by 00Z Wednesday. A
surface trough will develop upstream of the deepening low off
the Atlantic coast, generally paralleling the I-95 corridor
during the afternoon. With cold air aloft associated with the
upper low and potential for some surface heating (albeit
relatively minimal given the expected pervasive cloud cover),
scattered showers should develop again in much of the Northeast,
including at least northern portions of our area. With at least
marginal instability available, thunderstorms are possible,
especially north of the Mason-Dixon Line. This is true despite
the persistent near-surface onshore flow, leaving much of the
area subject to considerable low clouds and another cool day.
Generally went on the cool side of guidance Tuesday given
concerns for decent onshore flow, especially in PA/NJ. MAV
guidance looked too warm, so generally favored MET guidance for
temperatures tomorrow. Temperatures may not exceed 60 in the
Poconos, and will likely struggle to reach 70 in much of the
urban corridor. Warmer temps may exist near Chesapeake Bay,
where breaks of sunshine may occur by late afternoon. Confidence
in temperature forecast tomorrow is well below average.
&&
.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
A warming trend will take place from Wednesday through Monday.
The period will begin with temperatures typical of late April
and it will end with temperatures typical of late July.
A mid level low is forecast to be located over northern
Pennsylvania on Tuesday evening. It is expected to slide
southwestward over the upper Ohio River Valley for Wednesday and
Wednesday night before lifting northeastward on Thursday and
reaching Canada`s Maritime Provinces on Friday.
The period from Tuesday night through Thursday should remain
cool and a bit unsettled in our region with the low meandering
in our vicinity. We keep mostly to partly cloudy skies in the
forecast along with a chance of showers.
The mid level long wave trough over the northeastern states is
expected to give way to ridging from the west over the weekend
and on Monday. As a result, our weather is anticipated to
transition from spring-like to summer-like. Surface high
pressure is forecast to move from the southeastern states to the
western North Atlantic putting our region in a very warm and
increasingly humid south to southwest flow.
A weak impulse traveling in the mid level flow and an
associated surface trough may touch off some showers and
thunderstorms on Saturday afternoon. Otherwise, the weekend and
Monday look to be mostly rain-free.
&&
.AVIATION /02Z TUESDAY THROUGH SATURDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas.
L/IFR ceilings continue at ACY and MIV this evening with IFR
ceilings spreading across the rest of the TAF sites after
midnight when there is also the potential for thunder at RDG
and ABE.
CIGs/VSBYs are not expected to improve quickly Tuesday, and more
scattered showers and isolated storms are possible, especially
from KPHL north. Winds generally 5 kts or less through tonight,
becoming east or northeast 5 to 10 kts tomorrow. Overall
confidence in TAFs is slightly below average.
OUTLOOK...
Tuesday night through Thursday...Mainly VFR with a chance of
showers.
Thursday night through Friday night...Mainly VFR.
Saturday....Mainly VFR. A chance of afternoon showers and
thunderstorms.
&&
.MARINE...
Sub-advisory conditions are expected through Tuesday, though
seas will be building with increasing east-northeast winds by
afternoon. Winds/seas will approach advisory levels by late
afternoon as a surface low deepens in the western Atlantic.
Additionally, patchy fog is possible tonight, especially off the
New Jersey coast.
There is a good chance for rain and embedded storms this
evening, with another chance of storms tomorrow.
OUTLOOK...
Tuesday night and Wednesday...A Small Craft Advisory is in
effect for our ocean waters for northeast winds gusting in
excess of 25 knots and for wave heights building to 5 to 6 feet.
Wednesday night through Thursday night...A northeast flow
should keep wave heights on our ocean waters in the 5 to 6 foot
range. Wind gusts in excess of 25 knots remain possible,
especially on Wednesday night and Thursday.
Friday through Saturday...No marine headlines are anticipated.
RIP CURRENTS...
There is a moderate risk of rip currents on Tuesday along the
New Jersey coast, as east-northeast winds become established
and wave heights build through the day. For Delaware, a low risk
of rip currents.
&&
.TIDES/COASTAL FLOODING...
A developing northeast flow will cause water levels to build
along the coasts of New Jersey and Delaware during the mid week
period. We may begin to approach the minor flooding threshold at
some locations during the evening high tides on Tuesday,
Wednesday and Thursday. While we do not expect any widespread
minor flooding at this point, we are keeping an eye on trends
especially regarding the Wednesday evening high tide.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...None.
NJ...None.
DE...None.
MD...None.
MARINE...Small Craft Advisory from midnight Tuesday night to 6 PM EDT
Wednesday for ANZ452>455.
Small Craft Advisory from 6 PM Tuesday to 6 PM EDT Wednesday
for ANZ450-451.
&&
$$
Synopsis...Franck/Iovino
Near Term...CMS/Franck
Short Term...CMS
Long Term...Iovino
Aviation...CMS/Franck/Iovino
Marine...CMS/Franck/Iovino
Tides/Coastal Flooding...
Area Forecast Discussion
National Weather Service Tallahassee FL
1026 PM EDT Mon Jun 5 2017
.UPDATE...
Scattered showers and a few thunderstorms continue across the area
this evening. Expect activity to increase in coverage and
intensity overnight, with the heavier activity developing over the
Gulf before lifting northward. Still some uncertainty as to where
the heaviest rainfall axis will be, so will let the overnight
shift make the final decision on any potential Flood Watches.
&&
.PREV DISCUSSION [739 PM EDT]...
.NEAR TERM [Through Tonight]...
Scattered showers and thunderstorms continue to move north across
our inland areas in a very moist environment, with PWAT values
around 2" as deep layer southerly/southwesterly flow continues to
the east of an upper level trough. As a result of the ample moisture
and sea breeze/outflow boundary forcing, showers and thunderstorms
will remain likely across SE Alabama and SW Georgia from this
afternoon into the early evening, eventually moving north of our
area this evening. Due to ample cloud cover, instability has been
suppressed to 1000-1500 J/kg or less of SBCAPE and along with
effective bulk shear around 20 kts or less, severe weather is not
anticipated today. Brief gusty winds and locally heavy rain are
possible with the strongest storms.
The aforementioned upper level trough, currently centered over
eastern TX and the northwestern Gulf, will move eastward overnight
and an upper level jet streak will gradually intensify over our area
during this time. Along with very moist air remaining in place (PWAT
values near or over 2") and a surface trough or broad area of low
pressure moving into our western areas, widespread showers and
thunderstorms are expected to develop overnight into the early
morning hours. Periods of heavy rain are possible, although some
uncertainty remains regarding potential rainfall amounts during this
period with latest CAMs showing differing solutions overnight.
Latest HRRR runs bring widespread showers and thunderstorms
northeast from the Gulf across our area between 06-12Z, with several
hours of moderate to heavy rain possible across parts of north
Florida. However, this morning`s NSSL WRF run showed a more
progressive MCS moving from west to east across our area during this
time, which would produce a much more brief period of heavy rain for
much of our area. Depending on which scenario unfolds, localized
areas could see up to 2-3 inches overnight (most likely in north FL
where the moisture and instability are highest). Low temperatures
are expected to remain in the low-mid 70s across our area.
.SHORT TERM [Tuesday Through Wednesday Night]...
The latest NWP models are in good agreement in bringing the deep-
layer trough (currently over east TX) slowly eastward to a
position over our forecast area late Wednesday night. The most
favorable environment for heavy rain appears to be from early
Tuesday through early Wednesday, as relatively strong Q-G forcing
coincides with abnormally high amounts of deep-layer moisture.
(Precip water values will continue to be around 2 inches). The
GFS and NAM forecast warm cloud depth exceeding 12,000 ft during
much of this time frame, supportive of efficient (i.e. heavy) rain
processes. It`s not a question of whether or not it will rain,
it`s how much and how long, and this will likely depend on yet-to-
be-resolved mesoscale features. For a more detailed QPF
discussion see "HYDROLOGY" section below. Rain chances will taper
off from northwest to southeast Wednesday night as the upper
trough and associated surface cold front moves southeast across
our forecast area.
Unusual for summer in our region, but 0-6 km bulk shear values are
expected to increase to around 35 kt Tuesday afternoon, which would
suggest some potential for organized storms, perhaps even some
updraft rotation. However, it`s unclear how quickly the stable
near-surface layer (leftover from Tuesday morning`s storms,
assuming our forecast verifies) will "mix out" by afternoon,
especially if there is a lot of convective debris (i.e. mid-high
clouds). Thus the severe storm threat remains marginal, with
isolated damaging winds being the main threat.
.LONG TERM [Thursday Through Monday]...
The anomalously deep upper trough over the eastern CONUS to begin
the period will gradually fill through Saturday, with an upper ridge
developing over much of the eastern CONUS by early next week. PoPs
will be below average through Saturday with an abnormally dry
airmass in place behind the cold front passing through our area
Wednesday night and early Thursday. PoPs will gradually return to
average (about 40%) by early next week, mainly during the
afternoon and evening hours. High temperatures will be in the
upper 80s Thursday and Friday, then lower 90s for the remainder of
the period. Low temperatures will be in the 60s through Friday
night, then in the lower 70s. A drop in humidity will make it feel
a little more pleasant than usual Thursday and Friday.
.AVIATION [Through 00Z Wednesday]...
Showers have lifted north of all terminals this evening, with the
break expected to last until after midnight. Large area of showers
and thunderstorms will overspread the area from south to north
late tonight, impacting all terminal through early afternoon with
at least MVFR conditions. Rain is expected to taper off, with
improving cigs by afternoon.
.MARINE...
A weak, non-tropical low pressure system in the western Gulf of
Mexico will generate relatively strong south winds through
Wednesday. Winds will become north and subside to around 10 knots
late Wednesday and Thursday in the wake of a late season cold
front.
.FIRE WEATHER...
With widespread rain expected over the next two days, no fire
weather concerns are anticipated.
.HYDROLOGY...
Our local ensemble of Convection Allowing Models indicates that much
of our forecast area will get 2 to 4 inches of rain through
Wednesday, mostly from late tonight through Tuesday night. Two
inches wouldn`t be much of a concern for our local river system,
but 4 inches or more could lead to flooding, especially in some of
the faster-responding basins in south GA, AL, and the FL
Panhandle. There is a 30 to 40% chance of exceeding 9 inches of
rain (within 25 miles of a point) with this event. Though such
amounts would be very isolated, they would be enough to produce
flooding, especially on the off chance this were to occur in a
city, where local drainage could be overwhelmed. We have not
issued a Flood Watch because the heavy rain won`t begin until
early Tuesday, but the overnight shift will evaluate the
situation, and hopefully begin to see if the rain is evolving as
forecast.
&&
.PRELIMINARY POINT TEMPS/POPS...
Tallahassee 72 85 72 85 67 / 80 80 60 60 30
Panama City 74 83 74 83 70 / 100 70 60 50 20
Dothan 71 82 69 82 64 / 70 80 60 40 10
Albany 72 83 69 83 65 / 70 100 60 50 10
Valdosta 71 83 71 84 66 / 70 100 60 70 30
Cross City 73 84 74 84 69 / 80 70 60 60 60
Apalachicola 74 84 75 83 69 / 100 70 60 50 30
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
FL...High Rip Current Risk until midnight EDT /11 PM CDT/ tonight for
Coastal Bay-South Walton.
GA...None.
AL...None.
GM...None.
&&
$$
UPDATE...Camp
NEAR TERM...Lahr
SHORT TERM...Fournier
LONG TERM...Fournier
AVIATION...Camp
MARINE...Fournier
FIRE WEATHER...Camp
HYDROLOGY...Fournier