Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 07/02/17
Area Forecast Discussion...UPDATED
National Weather Service Albuquerque NM
544 PM MDT Sat Jul 1 2017
.AVIATION...
00Z TAF CYCLE
Showers and thunderstorms expected to continue through this evening
across central and eastern areas, perhaps lasting past midnight on
the eastern plains. Some strong to severe storms will continue to be
possible with large hail, gusty downburst winds, and heavy downpours
temporarily dropping ceilings/visibility to MVFR. A TEMPO group for
either SHRA or TSRA for a couple of hours this evening in all TAFs
except KGUP and KFMN. Confidence is low that widespread low stratus
clouds will develop overnight, but isolated spots are possible
especially in the east. Showers and thunderstorms expected again
Sunday afternoon, mainly south of I-40 and east of I-25. CHJ
&&
.PREV DISCUSSION...339 PM MDT Sat Jul 1 2017...
.SYNOPSIS...
A moist and unstable air mass will support scattered to numerous
thunderstorms east of the Rio Grande Valley through late evening
including another round of severe storms, especially on the eastern
plains. Going into Sunday and Independence Day, drier air and
strengthening high pressure aloft will lead to fewer storms with the
more favored areas east of the central mountain chain as well as the
southwest high terrain. Strong high pressure aloft is then expected
to center over the Four Corners region by Wednesday and remain just
north of the state through the end of next week.
&&
.DISCUSSION...
Deep, moist convection as far west as the southeast slopes of the
Chuskas as of early afternoon, with several impressive updrafts
already evident along and just east of the Divide as well as along
the Sangres and immediate east slopes. Last night`s easterly push was
perhaps a bit more robust than what models indicated. In any event,
atmosphere is primed to support another round of isolated/scattered
severe storms east of the Divide and especially east of the RGV as
the afternoon progresses and well into the evening with severe
impacts likely for areas that were devastated by damaging hail/70+
mph winds less than 24 hours ago. Uncapped mixed layer CAPE values
generally 2000-3000 J/kg across the east and generally 1000-1500
J/kg between the Divide and central valley corridor. Mid- level
westerlies are not quite as strong as they were 24 hours ago but even
so effective bulk shear sufficient to support rotating
updrafts/large hail with high likelihood of large, severe clusters
organizing on the high plains as cold pool dynamics come into play
during the evening. Storm motions should be slightly slower than
Friday PM and if the latest HRRR shows most severe threat ending by
11pm.
Not much change to previous thinking or forecast going into the first
week of July. 500mb ridge centered along the Borderland with broad
westerly flow in place. Models suggest a weak shortwave dropping
southeast out of the Colorado Rockies Sunday afternoon/evening that
may boost coverage for NC/NE areas going into the second half of
Sunday. 500mb Four Corners high then begins process of strengthening
and shift northward Monday/Tuesday eventually shifting just north of
the state by mid/late week. An extended period of northeast to
southwest or east to west flow aloft anticipated. kj
&&
.FIRE WEATHER...
Scattered to numerous showers and thunderstorms are taking shape
over northern New Mexico, and look to be gradually blossoming over
central parts of the state as well. An active evening of storms is
expected as this activity rolls eastward into the plains with some
cells producing hefty downpours, large hail, and gusty outflow
winds. Overall, prevailing winds have been trying to veer mostly
southerly with a bit of a convergent line hovering near or just west
of the Continental Divide: drier south southwest winds to the west
of this line with more moist south southeast winds on the east. This
has been a focus for storms early this afternoon, but they should
fill in east of it as the afternoon and evening wears on. Lowest
humidity is found west of this convergent line in far western zones
of NM where RH has dropped to less than 15 percent. After storms
settle and move out of NM tonight, excellent RH recovery is expected
to grace the eastern half of the state while the far western zones
observe poor RH recoveries.
Into Sunday, high pressure will start to jog northward with surface
winds responding by turning more westerly. This will dry out the
dewpoints some, not enough to fully eliminate storm potential, but
coverage will certainly dwindle compared to today. Some dry storms
will also be possible, especially in the west central to
southwestern mountain zones. Prevailing wind speeds will be light to
moderate Sunday afternoon, but any storm outflows (especially drier
storms) will be capable of hurling out very strong gusts. RH will
range from less than 10 percent in the far west up toward 25 percent
in the far eastern zones while temperatures climb back up to, if not
slightly above average. Instability will be prevalent with high
Haines indices of 5 to 6 across the forecast area.
Through next week high pressure will continue to build northward
over the Rockies. Through this time, low layer moisture will be
attempting to slosh farther west into NM. It should inch westward
each day, encompassing much of the east by mid week when a couple of
back door fronts aid. Some diffuse mid to upper level subtropical
moisture will also attempt to come over the southwestern mountains,
keeping a low chance for storms going.
52
&&
.AVIATION...
18Z TAF CYCLE
Active shower and thunderstorm pattern is expected across northern
and central New Mexico today and this evening. The focus would seem
to be along the central mountain chain initially before storms roll
eastward into the plains this evening. Secondarily storms should also
develop over portions of the Continental Divide and toward the Jemez
mountains. Some strong to severe storms will be possible with large
hail, gusty downburst winds, and heavy downpours temporarily dropping
ceilings/visibility. Confidence is low that widespread low stratus
clouds will develop overnight, but some isolated spots are possible.
52
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
Area Forecast Discussion
National Weather Service Gaylord MI
1152 PM EDT Sat Jul 1 2017
.UPDATE...
Issued at 952 PM EDT Sat Jul 1 2017
Reasonably potent shortwave is digging toward nw Superior.
Associated ascent is supporting upstream convection. The most
persistent showers, now moving e of ISQ and Munising, continues to
weaken (even as it it about to move into far western Mack Co).
Further south, deep convection is increasing in coverage w of MBL,
including some lightning within the past 30 min.
To the north, decreasing trend in central/eastern upper mi is
expected to reverse as the upstream wave exerts a greater
influence. Have needed to accelerate the onset of pops somewhat,
but will maintain high pops arriving in eastern upper MI as the
night proceeds. May also be able to start to decrease pops in
western Chip/Mack Cos before 12z.
To the south, will be boosting pops in nw lower for the next 6
hours. Rap is viewing the idea of some showers moving in more
favorably. Will not add thunder just yet, but will be monitoring.
Low clouds have been a bit reluctant to depart APN/Rogers/
Drummond, and have stretched out cloud cover there a little
longer.
&&
.NEAR TERM...(Tonight through Sunday)
Issued at 254 PM EDT Sat Jul 1 2017
...Unsettled weather continues...
High impact weather potential: Minimal. Low chance of isolated
severe thunderstorm over northeast lower Sunday afternoon.
Pattern Synopsis/Forecast...Unsettled weather pattern continues
through the weekend, with broad upper trough and embedded shortwave
energy bringing precipitation chances. Weak wave over Wisconsin
will produce a few upstream showers and thunderstorms late this
afternoon, with some of this activity trying to push into western
parts of northern michigan this evening. Difficult to see much more
than an isolated shower this evening west of Interstate-75, with
limited forcing/moisture/instability across the area. Will carry
very low POPS in this area, with an emphasis on mainly dry
conditions.
Stronger wave drops out of southern Canada and into the northern
lakes later tonight in Sunday morning. Best chance of precipitation
will be north of M-32 where more favorable upper forcing (DPVA and
upper divergence associated with upper jet)and deeper moisture will
reside. Will trend POPS in this direction, with highest POPS from
the Tip of the Mitt into eastern upper within the H9-H7 theta-e
ridge. Rainfall amounts not that impressive, with most areas less
than 0.25 inches (a few higher totals possible eastern upper).
Instability will increase with MUCAPES 500-1000 J/kg, so will
include isolated thunder. Instability/deeper moisture linger into
the afternoon hours mainly east of I-75 and south of M-72. Low
chance of an isolated thunderstorm (southern areas) as plume of
steeper mid level lapse rates and modest mid level flow work through
the southern half of Michigan. Temperatures warmer on Sunday,
ranging from the upper 60s over upper Michigan to the upper 70s near
Saginaw Bay.
&&
.SHORT TERM...(Sunday night through Tuesday)
Issued at 254 PM EDT Sat Jul 1 2017
...Pleasant Holiday Weather...
High Impact Weather Potential...none.
Pattern Synopsis/Forecast...The weak cold front having pushed
through the region early in the day, high pressure now builds into
the forecast area with accompanying higher 500 mb heights overnight
and the 700-500 mb layer RH dropping to less than 10%. That same
basic idea holds through the day on Monday as well. Monday evening
there is an issue between the ECMWF and the GFS with higher clouds
moving on the GFS. Not sure the moisture on the GFS is real, as the
front end of the moisture plume begins to dry out once over Michigan
with each successive time frame of the model. By 12z/Tues (4 JUL),
the sfc high is over the region and the dry air continues over the
state through 00z/Wed.
Primary Forecast Concerns...Not to much to worry about. The NAM
wants to bring in the precipitation from the south on Tuesday
afternoon, but a look at the SREF only shows 1 or 2 members showing
a few hundredths. The rest of the members are dry like the ECWMF and
the GFS. So for the next 48 hours, it looks dry. So warm and dry
on July 4th. No fire weather issues with Tuesday min RH values in
the 40s.
.LONG TERM...(Tuesday night through Saturday)
Issued at 254 PM EDT Sat Jul 1 2017
With high pressure overhead, most of the extended period looks to be
warm and sunny. A couple of disturbances could bring some scattered
showers in the mid to late week timeframe. First up, a low out of
the Plains passing to our south Wed/Thu could get far enough north
to bring us some showers. Behind that, broad H5 troughing to our
north could extend into the Great Lakes sweeping a few showers
through with it before another area of high pressure builds back
into the region clearing things out. Temperatures will run near to
slightly above normal.
&&
.AVIATION...(For the 06Z TAFS through 06Z Sunday night)
Issued at 1152 PM EDT Sat Jul 1 2017
MVFR cigs possible PLN, MVFR vsbys possible APN Sunday morning.
Low-levels are drying out somewhat, as high pressure noses east
from the upper MS valley. However, an upper-level disturbance will
support some shower chances late tonight into Sunday morning.
Shower/t-storm threat could get re-invigorated Sunday afternoon,
especially away form Lake MI. Best rain chances at PLN, which will
lead to lower cigs there for a time. APN also a window for some
fog development before 12z. Otherwise VFR.
Light winds tonight. Somewhat gusty w to nw winds on Sunday.
&&
.MARINE...
Issued at 254 PM EDT Sat Jul 1 2017
Winds remain below advisory level through tonight. An area of low
pressure with an associated cold front approaches from the west
late tonight into Sunday. This will gradually tighten the gradient
and increase the wind speeds. All nearshore areas will be gusty
on Sunday (20kts), with small craft gusts expected from the
Straits into northern Lake Huron due to funneling/coastal
convergence. Small craft gusts also likely on the St. Marys river
system.
Other areas may occasionally get close to small craft conditions,
especially areas along Lake Michigan from Frankfort to Grand
Traverse Light. But for now will not include them in the advisory.
High pressure will settle into the Great lakes Monday-Tuesday,
resulting in a lighter wind pattern.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...SMALL CRAFT ADVISORY from noon to 7 PM EDT Sunday for LHZ345-347-
348.
LM...NONE.
LS...SMALL CRAFT ADVISORY from noon to 7 PM EDT Sunday for LSZ322.
&&
$$
UPDATE...JZ
NEAR TERM...JRK
SHORT TERM...JSL
LONG TERM...ALM
AVIATION...JZ
MARINE...JRK
Area Forecast Discussion
National Weather Service Birmingham AL
713 PM CDT Sat Jul 1 2017
.UPDATE...
Late Afternoon/Evening Update and 00Z Aviation.
&&
.SHORT TERM...
Previously updated the late afternoon forecast for much increased
rain chances north and west. Looking at the 12 hr accumulated
precip dual pol estimate, The I-59 corridor has reported rain in
most all locations with the small exception of an area between
TCL/BHM and far northern Marion County. So the update appeared to
be warranted. Showers and thunderstorms continue this hour. It
appears much of the activity has been focused along a conglomerate
outflow boundary seen stretching from the Carolinas to Texas.
This conglomeration is now a pre-frontal trough. The RAP analysis
has SBCape/Mixed Layer Cape values in the 2500-3500 range with
Downdraft capes in the 100 neighborhood. The best cold pool
appears like its over northern Mississippi and points west. Mid
level lapse rates are poor and overall convergence is banking on
the daytime instability to keep it going. So, did bump pops higher
for the initial few hours here til 8 or 9 pm , then kept only a
20 pop. Believe the convection will diminish quicker than last
night but some areas will certainly get some rain in the next few
hours.
A strong storm or two is also possible for the next hour or so.
The main threat would be potentially severe wind gusts and some
hail. Due to the moisture content and potential training/rain
rates, will keep mention of a heavy downpour too. But will let the
Flash Flood Watch expire at 7pm. Areas farther south will have
the least rain chances through the overnight based on position of
boundaries. Will monitor closely as plenty of outdoor events are
happening this evening. Lows will be a sticky 70 to 75.
75
Previous short-term discussion:
--Marginal Risk of isolated afternoon-to-evening severe
thunderstorms with damaging wind potential--
With the 16:30Z/11:30AM update to the convective outlook, the
previous `Slight Risk` area that was outlined for a chunk of the
region has been lowered to a `Marginal Risk.` With this update,
all of Central Alabama is now under a `Marginal Risk` of severe
thunderstorms this afternoon, with a few cells potentially holding
on into the evening hours.
As of 17:30Z/12:30PM, visible satellite showed bands of cumulus
clouds across Central Alabama, with some towering underway + a few
blips on BMX radar as we`ve surpassed our convective temperature.
Dew points are forecast to remain in the 70s (F) this afternoon,
as temperatures peak in a range from the upper 80s to low 90s (F);
this is of course contributing to an unstable air mass, with
surface-based CAPE values in excess of 2,500 J/kg. Aloft, there`s
a broad 500mb trough extending southward from the Great Lakes
region, though flow in our region is quite weak, and am not seeing
any shortwaves or features in water vapor. Bulk shear values are
either side of 25-knots given overall light flow through the
column. So, while there`s ample instability for storms, large-
scale forcing is seemingly absent for substantial development and
coverage of severe thunderstorms in our region (more favorable
toward our north). That`s not to say we will not have an instance
of severe weather in our forecast area.
Given the shear/instability setup today, the current thinking is
that we`ll have development of multi-cell thunderstorms, driven
in part by surface boundaries and orographic lift, and any of the
strongest cells could yield a risk of damaging winds as DCAPE is
in the vicinity of 1,000 J/kg. We`ll have a keen focus on any
congealing storm cells + organized outflow, as this would tend to
increase damaging wind potential. In reality, sub-severe winds
could take down some trees since June`s rainfall was in excess of
200% of normal in many areas (something to consider). The risk of
severe storms is highest through the afternoon and will gradually
subside around/post-sunset.
89^GSatterwhite
.LONG TERM...
Sunday through Friday.
A persistent northwesterly mid-level flow/"ring of fire(works)"
pattern will remain in place Sunday and through much of the
upcoming week, between subtropical ridging stretching from the
Four Corners to the Gulf and troughing over eastern Canada. By
the end of the week a strong 598 decameter closed 500mb
anticyclone will have developed over the Central Rockies.
Meanwhile a hot/humid/unstable air mass will remain in place over
Central Alabama. While the northwest flow will prevent a truly
tropical air mass (e.g. PWATs over 2 inches) from being over the
area, PWATs will still remain elevated in the 1.8 to 1.9 inch
range. A northwest to southeast oriented moisture axis will be
located from the Central Plains to the Southeast. A parade of MCVs
will likely move through the region, possibly accompanied by
outflow boundaries and MCSs. Rain chances will remain in the
40-50% range overall, with 15 kts of mid-level flow allowing
storms to move and result in increased coverage. Rain chances but
will need to be adjusted upward during some time periods
depending on the exact timing of these disturbances.
One such wave, currently associated with convection over west
Texas, may move towards the area Sunday (with additional MCVs
possible Monday and Tuesday). Mid- level lapse rates are expected
to be weaker tomorrow than today assuming fairly widespread
convective overturning today. But with sufficient DCAPE present
and plenty of instability expect some strong storms with gusty
winds and frequent lightning. This will be the case for the next
couple days as northwest flow keeps relatively cool/dry (low
theta-e) air aloft over the area over high theta-e air at the
surface, so be sure to move indoors when storms approach. Any
severe threat (damaging winds) will be dependent on any MCSs and
boundaries that form and microburst parameters, which will be
dependent on mesoscale factors and assessed each day via the
morning sounding and CAMs. Will also continue to have to monitor
rainfall amounts for possible flooding due to saturated soils and
elevated levels on area rivers and creeks. Also, outside of storms
heat index readings will be in the upper 90s to low 100s,
currently expected to remain below heat advisory criteria (105).
Looking specifically at the 4th of July, generally expect better
coverage of showers and storms the further east you go (further
from the ridge) but anywhere could see scattered showers/storms.
Wednesday through Friday, a stronger shortwave trough and surface
low will be moving from the Ohio Vally to the Northeast. A
trailing wind shift at the surface and shear axis aloft may result
in increased rain chances across the forecast area Thursday and
Friday.
32/Davis
&&
.AVIATION...
00Z TAF Discussion.
Showers and thunderstorms will cause restrictions locally at
terminals here the next 3 hours or so. Some of the storms will
produce gusts into the 40kt range, reduced vis, and ceilings
generally VFR. The atmosphere remains very moist and not a get
deal of change since last night. Therefore, will lean toward
persistence. Generally a VFR forecast, with a brief period around
sunrise again of potential MVFR/IFR ceilings. Then the clouds
rise/thin and afternoon thunderstorms again.
75
&&
.FIRE WEATHER...
A humid and stormy pattern will remain in place this weekend and
next week. There are no fire weather concerns.
&&
.PRELIMINARY POINT TEMPS/POPS...
Gadsden 72 87 71 88 70 / 40 50 30 50 30
Anniston 72 87 71 89 71 / 60 50 30 50 30
Birmingham 73 89 72 89 72 / 40 50 30 50 30
Tuscaloosa 74 90 73 93 73 / 40 50 30 40 20
Calera 73 88 72 90 72 / 60 50 30 40 20
Auburn 73 87 72 89 73 / 50 50 30 40 30
Montgomery 74 91 73 93 74 / 50 50 30 40 20
Troy 74 90 72 92 73 / 50 50 30 40 20
&&
.BMX WATCHES/WARNINGS/ADVISORIES/...
Flash Flood Watch until 7 PM CDT this evening for the following
counties: Blount...Calhoun...Cherokee...Etowah...Jefferson...St.
Clair...Walker...Winston.
&&
$$
Area Forecast Discussion
National Weather Service Taunton MA
947 PM EDT Sat Jul 1 2017
.SYNOPSIS...
A weak cold front will move across the region late tonight into
Sunday morning bringing a slightly less humid airmass but still
very warm Sunday. A secondary cold front/surface trough sweeps
across the area Monday and may be accompanied by a few afternoon
showers and thunderstorms, but by no means a washout. High
pressure builds into the area Tuesday and Wednesday of next
week, providing seasonably warm temperatures and comfortable
humidity.
&&
.NEAR TERM /THROUGH SUNDAY/...
10 pm update...
Scattered showers and thunderstorms continue to fire across the
northeast including New England with mid level trough moving
across the region, providing sufficient forcing for ascent.
Surface dew pts in the upper 60s and lower 70s providing MLcapes
of around 500 j/kg. Thus sufficient instability for convection
to sustain itself along with 0-6 km shear of around 30 kt and
marginal mid level lapse rates of 6C/KM. So while scattered
thunderstorms over eastern NY will likely hold together as
activity enters New England the next few hours, storms should
remain sub-severe with main concern being heavy rainfall with
PWATs around 2 inches.
Otherwise expect a very warm and muggy night with lows only in
the upper 60s and low 70s. Given the tropical nature of this
airmass expect patchy fog overnight.
Previous forecast captures this theme very well so no major
changes with this forecast update.
Previous discussion...
*** A few severe thunderstorms possible across western MA/CT
with strong winds & very heavy rainfall ***
Severe thunderstorm watch for portions of western MA and
northwest CT until 01z. Strongest forcing for ascent will
remain to the north and west assocd with the mid level shortwave
moving through the eastern Great Lakes. However, moderately
unstable environment with MLCAPES 1000-1500 J/kg combined with
35-40 kt of 0-6km shear will create a favorable environment for
a few strong to severe t-storms in western New Eng. Area of
showers and storms lifting NE across northern New Eng while
widely sct showers and isold thunder moving into western MA and
CT. This activity will need to be monitored for intensification
given the environment. In addition, more convection further
west across central NY and NE PA and HRRR organizes this into a
line as it moves into western New Eng 23-00z. The primary severe
weather threat is damaging wind gusts but heavy rainfall also a
concern with any storms with PWATs around 2 inches.
Expect convection to weaken as it moves east toward the coastal
plain tonight and encounters more stable marine influence. Still
a few showers and an isolated t-storm expected with low level
theta-e ridge and low level jet ahead of weak front moving
across the region.
Marine stratus along the south coast will slowly advect north,
spreading further inland tonight. Areas of fog along the south
coast. Warm and humid with lows mid 60s to around 70 as drier
air arrives on Sunday.
&&
.SHORT TERM /SUNDAY NIGHT/...
Sunday...
Surface front appears to wash out near the coast but well
defined 850 mb fropa noted with sharp decrease in 850 mb
dewpoints in the morning. With increasing mixing during the
day, expect dewpoints will drop into the upper 50s to lower 60s
in the afternoon but still mid/upper 60s near the south coast
with SW winds. Lingering stratus and patchy fog near the coast
in the morning, otherwise increasing sunshine as subsidence
develops behind departing shortwave. The drier air and lower KI
will limit instability and so dry weather is expected. 850 mb
temps 15-16C will support highs well into the 80s to near 90
degrees.
Beach Forecast...persistent southwest/onshore winds the past few
days diminish Sunday but leftover SW swells may result in rough surf
and possible moderate to strong rips for south facing ocean beaches
of RI and MA.
Sunday night...
Another mid level shortwave tracks well to the north with
minimal impact for SNE. Quiet night expected with dry weather
and lows in the 60s.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
Big Picture...
Traffic jam in the upper flow over and near North America through
the first week of July. Closed low and trough over the Eastern
Pacific and Gulf of Alaska linger off the west coast. Upper ridge
builds over western North America with hot temperatures. The ridge
shifts east a little from time to time but otherwise persists
through the forecast period. This induces an upper trough over
eastern North America with one shortwave after another racing
through the flow.
Model mass fields are similar through Saturday, although with some
differences from their 00Z runs. Model thermal fields are similar
through Friday morning, with small differences Saturday.
The similarity among the models brings moderate to high confidence
in the long term forecast.
Details...
Monday...
Shortwave from Central Canada sweeps through the Great Lakes Sunday
and across New England Monday. An associated surface cold front
moves through Southern New England during the late afternoon and
early night. Deep mixing to at least 800 mb, supporting surface max
temps in the 80s with most inland spots mid and upper 80s. Dew
points in the 60s in the morning will lower later in the afternoon
and night after the cold front moves through. This will allow
nighttime min temps roughly 55 to 65.
Independence Day and Wednesday...
High pressure builds over the Northeast USA for the holiday and the
day after. Dry weather, with daytime sun generating mixing that
reaches to 800 mb, with temperatures at that height supporting max
sfc temps in the low to mid 80s. With dew points in the 50 and low
60s, expect min temps in the mid 50s to lower 60s.
Thursday through Saturday...
Shortwave ejects from the closed Pacific low pressure, rides over
the north side of the ridge, and digs over the Northeast USA later
in the week. Meanwhile a weak shortwave is pushed east by the
building western ridge and merges with the northern shortwave. The
result should be a period of convection as the system approaches.
Timing is the main question at this stage. Both GFS and ECMWF show
deep moisture on Thursday and Thursday night. The 00Z ECMWF was
about 6 hours faster that the GFS in moving the surface feature
through our area and 12 hours faster with the upper shortwave but
those differences went away with the 12Z run. The GGEM is an about 6
hours slower than the GFS and advertises more of a Friday storm. For
now, we will go with the faster timing while being mindful of the
potential for further model-to-model and run-to-run changes this far
in the future.
Both ECMWF and GFS show surface high pressure and upper shortwaves
on Saturday.
&&
.AVIATION /02Z SUNDAY THROUGH THURSDAY/...
Forecaster Confidence Levels...
Low - less than 30 percent.
Moderate - 30 to 60 percent.
High - greater than 60 percent.
Short Term /through Sunday Night/...
10 PM update...
Not much change from 00z TAFs, scattered thunderstorms overnight
but sub-severe with main concern being very heavy rainfall
potential. Combination of IFR-MVFR in low clouds and fog.
Earlier discussion below.
================================================================
Tonight...Moderate confidence. Expect IFR stratus to spread
north along the coastal plain with MVFR elsewhere. Patchy fog
developing along the south coast. Sct showers/t-storms will
weaken as they move toward the coast early tonight. SW winds
diminish.
Sunday...High confidence. Lingering MVFR/IFR cigs along the
south coast through mid morning, otherwise VFR. Lower
cigs/vsbys may linger over ACK until early afternoon.
Sunday night...High confidence. Mainly VFR, but patchy late
night fog possible.
KBOS Terminal...High confidence. Cigs lowering tonight with a
period of IFR possible. Strongest storms will likely remain
south and west of Logan/s airspace.
KBDL Terminal...High confidence. Sct showers/t-storms developing
around 00z. Brief strong gusts and heavy downpours possible in
the stronger storms. Lowering cigs tonight.
Outlook /Monday through Thursday/...
Monday...
VFR with brief local MVFR in showers/thunderstorms. West-southwest
winds gust to 20 knots. Winds shift from the northwest late in the
day or at night as a cold front moves through the region.
Tuesday-Wednesday...
VFR. Light northwest flow Tuesday and light variable flow Wednesday.
The flow will be light enough for the potential of sea breezes each
day.
Thursday...
Weather system approaches from the west. VFR, but with increasing
sky cover through the day. Areas of MVFR cigs/vsbys possible
Thursday night.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
Low - less than 30 percent.
Moderate - 30 to 60 percent.
High - greater than 60 percent.
Short Term /through Sunday Night/...High confidence.
Tonight...
Nearshore SW gusts to 25-30 kt diminishing later tonight as
the low level jet moves offshore. A few weakening showers or a
t-storm possible. Areas of fog will reduce vsbys to 1 mile or
less, especially south coastal waters.
Sunday...
Winds below SCA but leftover 5 ft swell southern waters will
gradually subside in the afternoon. Areas of morning fog.
Sunday night...
Winds and seas below SCA.
Outlook /Monday through Thursday/...
Monday...
A cold front moves across the waters late Monday and Monday night
bringing scattered showers and thunderstorms, mainly afternoon and
evening. Southwest winds lead the front, with gusts of 20 to 25
knots possible. Winds shift from the northwest behind the front
Monday night with speeds less than 20 knots. Seas remain 4 feet or
less through the period. A Small Craft Advisory may be needed prior
to the cold front passage.
Tuesday-Wednesday...
High pressure builds over the waters with winds less than 20 knots
and seas 3 feet or less. Local sea breezes may shift nearshore wind
directions from mid morning to evening. Areas of late night and
early morning fog with visibility less than 2 miles.
Thursday...
Weather system approaches from the west with a chance of showers and
thunderstorms. Best chance for this would be in the afternoon and at
night. South winds increase during the day with afternoon winds
gusting 20 to 25 knots. Seas mostly less than 4 feet, but may build
Thursday night with 5-6 foot seas on the outer waters late at night.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...None.
RI...Air Quality Alert from 11 AM to 11 PM EDT Sunday for
RIZ001>008.
MARINE...Small Craft Advisory until 11 PM EDT this evening for
ANZ231>235-237-251.
Small Craft Advisory until 10 PM EDT this evening for ANZ230-
236.
Small Craft Advisory until 8 AM EDT Sunday for ANZ250-254.
Small Craft Advisory until 11 AM EDT Sunday for ANZ255-256.
&&
$$
SYNOPSIS...WTB/KJC
NEAR TERM...WTB/KJC/Nocera
SHORT TERM...KJC
LONG TERM...WTB
AVIATION...WTB/KJC/Nocera
MARINE...WTB/KJC
Area Forecast Discussion
National Weather Service Charleston SC
1042 PM EDT Sat Jul 1 2017
.SYNOPSIS...
The area will remain on the periphery of Atlantic high pressure
while a surface trough persists inland.
&&
.NEAR TERM /THROUGH SUNDAY/...
As of 1035 PM: Coverage of thunderstorms will arrive over the
inland forecast area by midnight. Based on radar trends and
latest CAMs, thunderstorm coverage should favor the SC zones. I
will make another round of increases to near term PoPs and sky.
As of 940 PM: Latest SPC analysis and 0Z KCHS sounding indicate
that DCAPE values across the forecast area have increased to
1000 J/kg. In addition, the environment across the region
remains moderately unstable. Regional radar composite continued
to show lines and clusters of thunderstorms across the Piedmont
and Midlands. Given the favorable environment, I will update the
forecast to refine the placement and timing of PoPs through the
late night hours. The primary threat with the late evening/late
night thunderstorms will be strong to severe wind gusts.
As of 715 PM: KCLX shows a well defined sea breeze moving slowly
inland across SC/GA. Only a few showers have developed along the
sea breeze so far this evening. The sea breeze may aid in the
development of additional convection south of the Savannah River
later this evening. Otherwise, the arrival of late evening
thunderstorms, sourced from the Piedmont, continues to appear on
track.
As of 540 PM: Convection continues to increase within a lee
trough across the southern Appalachians foothills and Piedmont.
NAM12 Corfidi vectors indicate that steering flow should result
in the storms to push SE across the Carolinas and Georgia this
evening and late tonight. Latest SPC mesoscale analysis
indicates a band of DCAPE of values greater 1000 J/kg between
I-20 and I-85. These storms will have the potential to develop a
deep cold pool, which would provide greater push eastward. In
addition, normalized CAPE ranges between 0.2 to 0.15 m/s2
between the escarpment of the Appalachians to the coast. Based
on the environment, I will side with the more active NAM12 and
4km WRF, bringing a band of weakening convection across the
forecast area late this evening into the late night hours. The
20z HRRR appears too limited in coverage. I will update the
forecast to increase PoPs and sky.
Previous discussion:
The mesoscale convective vortex (MCV) that has been trekking
across Southeast Georgia today will exit off the lower South
Carolina coast in the 20-21z time frame. Subsidence near and
behind this feature has limited convection so far, which should
continue for a few more hours. High resolution data are similar
in showing convection firing along the piedmont trough and
potentially impacting portions of Southeast South Carolina later
this evening. Confidence in this particular scenario is only
low to moderate (at best), but the 4km NSSL- WRF, H3R and to
some extent the RAP have been depicting this scenario for
several runs now. Will limit pops to 20-30% for the overnight
hours with the highest gridded pops occurring this evening, but
further adjustments may be needed later as convective trends
become more apparent.
Mostly clear and partly cloudy skies will prevail through
daybreak Sunday with lows ranging form the mid 70s inland to
around 80 at the beaches. This assumes convection does not too
widespread. Could see a little patchy fog develop where rain
falls and skies clear, but do not anticipate anything
significant to occur.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
A very subtle upper trough will remain just to the west while robust
Atlantic high pressure persists to the east into the early part of
next week. Sunday will see the least coverage of precip and warmest
temps of the period owing to a deep westerly component to the flow
bringing a warm, continental airmass into the region. The primary
story Sunday will be the heat, with many locations reaching well
into the mid 90s under ample sunshine through midday...which
combined with dew points in the mid 70s will result in heat indices
near 105 - as warm as we have seen so far this year - for most away
from the immediate coast.
Low-to-mid level flow veers more south to southwesterly Monday and
Tuesday, allowing PWATs to climb back to near 2 inches. Models are
hinting at the possibility of a weak shortwave rounding the base of
the broad trough aloft Monday, with another disturbance possible
Tuesday. Though timing and location of these features is difficult
to pin down days in advance, POPs have been maintained above climo
values to account for the features. Overall, convective initiation
should still remain mostly confined to the sea breeze front,
with an overall low severe threat. Temps will return closer to
normal to start the workweek.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
Deep layered high pressure over the western Atlantic will
result in a fairly typical July pattern. Highs reaching into the
lower 90s with scattered showers and tstms, mainly in the
afternoon and evening. There are hints that a weak upper trough
will drop into the area Thursday and Friday which could increase
forcing for convection.
&&
.AVIATION /03Z SUNDAY THROUGH THURSDAY/...
Conditions are forecast to remain VFR through the 0Z period.
Radar and satellite trends and latest CAMs indicate that a band
of scattered TSRA will track across the SC coastal plain late
this evening into the late night hours. I will carry a VCTS at
KCHS between 6-9Z. Otherwise, winds are forecast to remain
steady from the SW, speeds generally less than 10 kts.
Extended Aviation Outlook: Brief flight restrictions are possible in
afternoon showers/thunderstorms at both KSAV and KCHS.
&&
.MARINE...
Tonight: A typical summer nocturnal surge will impact the waters
tonight as Atlantic high pressure remains centered well
offshore. Winds look to max out at 15-20 kt for the Charleston
County waters with 15 kt elsewhere. Seas will average 2-3 ft.
Sunday through Thursday: Broad Atlantic high pressure will remain in
control through the period. Expect light to moderate south to
southwest breezes to persist, with the normal summertime enhancement
near the coasts in the afternoon and post-dawn hours. Seas remain
mainly 2 to 3 feet in local wind waves and minimal incoming
swell.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...None.
SC...None.
MARINE...None.
&&
$$
NEAR TERM...NED
SHORT TERM...
LONG TERM...
AVIATION...NED
MARINE...
Area Forecast Discussion
National Weather Service State College PA
1157 PM EDT Sat Jul 1 2017
.SYNOPSIS...
A weak cold front will move east of the region overnight
bringing break in the humidity for the second half of the
weekend into early next week. Summertime heat and humidity will
return later in the week.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
As of 9PM a narrow line of convection extends from NW Tioga
County down into NW Clearfield County, and is settling slowly
ESE. The HRRR has been slow to move this feature and quick to
weaken it, leading to a low confidence forecast as to how far
into the Central Mountains the new storms will settle before
falling apart.
I`m still looking for the showers to weaken over the next 2-3
hours, with little or no rain remaining by midnight.
With skies expected to become clear to scattered, areas of fog
look like a good bet later tonight, especially where there was
substantial rain.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
Sunday looks cooler than normal in the NW. But, it should be
just a little warmer than normal in the SE thanks to a light
downslope and a good amount of sunshine there. Can`t rule out
an aftn SHRA/TSRA in the north or the Laurels under the colder
air aloft.
&&
.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
The upper level trough will continue to move eastward Sunday
night into Monday. Latest models have a quasi stationary
boundary forming through Pennsylvania Monday into Tuesday. This
could allow for showers along this line, though PWATS are low so
lack of moisture is a concern for developing any showers.
However there is a weak cold frontal boundary and coupled with
daytime heating could allow for convection along this line
Monday afternoon into Tuesday. There is good agreement on the
position and movement of the trough which gives me some
confidence that Tuesday through Wednesday should be dry due to
SFC high pressure. The latter part of the work week should be
more active with another trough swinging through the Southern
Great lakes region and the OHIO valley. This could bring some
showers and thunderstorms late Wednesday through Thursday.
Temperatures will be around normal through the week with a drop
in temperatures towards next weekend as the trough brings cooler
northwesterly flow into the region.
&&
.AVIATION /04Z SUNDAY THROUGH THURSDAY/...
Radar at 04Z showing dwindling showers along a weak cold front
across central Pa. Can`t rule out a brief vis reduction at KUNV
between 04Z-05Z. Otherwise, the main concern late tonight/early
Sunday remains the possibility for a period of fog/low cigs
developing at KBFD and KLNS. Wet ground, clearing skies and
light winds favor fog and satellite imagery already showing
patchy fog nearby. Any fog should burn off by around 14Z.
Otherwise, high pressure building over the region should ensure
widespread VFR conditions for the rest of Sunday.
.OUTLOOK...
Mon...Isold PM Tstorm impacts possible southern 1/2 airspace.
Tue...Isold PM Tstorm impacts possible southwest 1/3 airspace.
Wed...Isold PM Tstorm impacts possible.
Thu...Chance of showers and thunderstorms.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SYNOPSIS...La Corte
NEAR TERM...La Corte
SHORT TERM...Dangelo/Martin
LONG TERM...Ceru/Martin
AVIATION...Fitzgerald/Martin
Area Forecast Discussion
National Weather Service Goodland KS
730 PM MDT Sat Jul 1 2017
.UPDATE...
Issued at 729 PM MDT Sat Jul 1 2017
Isolated thunderstorms keep developing over the western portion of
the area due to a surface trough and weak shortwave trough.
Mesoanalysis is showing an adequate amount of Cape with no cap
yet. So expanded pops a little through the evening.
&&
.SHORT TERM...(This evening through Sunday)
Issued at 240 PM MDT Sat Jul 1 2017
Have added a slight chance to chance of thunderstorms generally
along and south of a line from Boyero and Cheyenne Wells Colorado
east through Wallace and Russell Springs Kansas from mid evening
through early Sunday morning. A weather disturbance is currently
producing some thunderstorms across the higher terrain of southern
Colorado and is expected to emerge onto the plains early this
evening. Low level jet will be going and with some elevated CAPE
should see a continued eastward progression. Operational HRRR has
been showing some damaging winds gusts over 58 mph for a few runs
now. Will keep a mention in the Hazardous Weather Outlook as a
result. Elsewhere should have a mostly clear to partly cloudy sky
with low temperatures in the upper 50s to mid 60s.
Late Sunday afternoon we may see an isolated thunderstorm or two
approach the Flagler area as convection develops on the Palmer
Divide and moves toward the east. Pretty healthy instability is
forecast across the east but moisture in the 850-500mb layer is
rather limited so for now have it dry. 850mb temperatures warm about
7F to 11F degrees across the area supporting afternoon temperatures
in the low to mid 90s.
.LONG TERM...(Sunday night through Saturday)
Issued at 158 PM MDT Sat Jul 1 2017
At the start of the period, northwesterly flow prevails aloft with
weak ridging over the western portion of the CONUS. Shower and
thunderstorm chances persist from the daytime period into Sunday
night as a disturbance works its way through the flow and southerly
flow at the surface draws moisture north. There will be enough shear
and instability to allow the threat for severe weather to last into
the evening hours, with storms spreading into the region from
Colorado. Showers and storms push east across the area overnight and
exit the region.
Active weather continues on Monday when a shortwave trough moves
through the northern portion of the upper ridge and crosses the High
Plains. Southerly flow ushers moisture into the region increasing
instability by the afternoon while shear strengthens. Am expecting
strong to severe thunderstorm development in the afternoon, lasting
into the evening. Large hail and damaging winds will be the main
threats. Again, thunderstorm activity looks to push east overnight.
A slight chance of showers and thunderstorms returns Tuesday
afternoon as the shortwave trough pushes east of the region. This is
followed by heights rising over the western half of the country and
a large area of high pressure expanding. The forecast area remains
under northwest flow through the end of the forecast period, on the
eastern edge of the upper ridge as it stretches eastward. Warm air
aloft caps the region Wednesday onward, leaving little to no chances
for precipitation.
High temperatures will be in the 90s during the long term period
(the warmest day being Thursday as highs peak in the upper 90s),
with lows in the upper 50s to upper 60s. Won`t be surprised if
temperatures trend warmer due to the dome of high pressure expanding
over the area.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 514 PM MDT Sat Jul 1 2017
Vfr conditions are expected through the period. For Kgld, south
winds near 14 knots will decrease into the 7 to 9 knot range
early this evening and continue through the rest of the period.
For Kmck, south southwest winds near 12 knots will decrease into
the 7 to 9 knots range during the early evening and will continue
until late tomorrow morning. Llws is expected between 06z and 12z.
Late tomorrow morning the winds will shift to the southeast
around 7 knots and continue through the rest of the day.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...BULLER
SHORT TERM...99
LONG TERM...JBH
AVIATION...BULLER
Area Forecast Discussion...UPDATED
National Weather Service Miami FL
822 PM EDT Sat Jul 1 2017
.UPDATE...
With the loss of diurnal heating, NWS radar shows
weakening showers as they drift westward over the Gulf waters.
Decreased PoPs over the interior through early morning to be
consistent with the latest radar trends. Short term models,
including the HRRR and WRF are showing a late night/early morning
boundary collision off of the Atlantic coast, firing up scattered
showers and perhaps a thunderstorms. Therefore, increased PoPs to
chance in the near shore Atlantic waters to account for this
possibility. Otherwise, updated the latest wind and sky grids. All
other variables appeared on track.
&&
.AVIATION...
The easterly winds will continue over the east coast taf sites
tonight into Sunday, as the wind speeds will be 5 knots or less
tonight increasing to around 10 knots on Sunday. The winds at KAPF
taf site will be light and variable tonight into Sunday morning,
before swinging to a westerly direction around 10 knots Sunday
afternoon. The weather will remain dry tonight over the east coast
taf sites, and VCSH will continue for KAPF taf site until 02Z
before going dry for rest of tonight. The east coast taf sites
will then see VCSH after 14Z Sunday, and VCTS for KAPF taf site
after 18Z Sunday. The ceiling and vis will remain in VFR
conditions tonight into Sunday.
&&
.PREV DISCUSSION... /issued 400 PM EDT Sat Jul 1 2017/
DISCUSSION...
Latest water vapor imagery shows a longwave trough
draped along the Mid-West with elongated upper level high
pressure stretching from the Gulf of Mexico to the western
Atlantic. Surface analysis indicates a semi permanent surface
high near Bermuda, typical for this time of year. The feature
continues to produce light east and southeast flow across South
Florida. The mornings MFL RAOB sounding 1.70 inches of PWAT with
CAPE over 2000 J/KG. Although not entirely impressive values,
enough moisture and instability was present to generate a few sea
breeze driven showers and thunderstorm over the interior this
afternoon, mainly near the Lake Okeechobee region. The HRRR and
Hi-Res WRF models, as with previous days, show activity spreading
towards Collier and mainland Monroe counties by the early evening.
The main threats with todays storms will likely be lightning,
brief heavy rain, and isolated winds up to 40 mph. After sundown
and the loss of diurnal heating, thunderstorms should decrease in
coverage and intensity. The easterly flow pattern will bring a
slight chance of showers to the east coast metro late tonight, as
they drift westward from the Atlantic. Synoptically, little
changes on Sunday. There may be slightly higher coverage of sea
breeze driven afternoon thunderstorms, especially in the interior,
with PWATs increasing to near 2 inches. Maximum temperatures will
hover in the upper 80s along the east coast region and low 90s
elsewhere.
Monday through Friday: A weakening ridge of the eastern CONUS will
allow for waves of deeper moisture to return from the southeast.
Stagnant surface high pressure near Bermuda will maintain east
southeast flow in the lower levels through the whole week. This
usually translates to night and early morning showers along the
east coast metro region, transitioning to sea breeze driven
showers/thunderstorms over the interior and Gulf coast during the
afternoons. Maximum temperatures will have little variation with
upper 80s along the east coast metro to low 90s elsewhere, normal
for early July.
MARINE...
Generally good boating conditions are expected
across South Florida into early next week under light east-
southeasterly flow. Isolated showers and thunderstorms are
expected over the open waters, particularly in the overnight and
morning hours, with more scattered coverage along the Gulf coast
in the late afternoons and evenings. Locally erratic winds along
with lightning will be possible in and around thunderstorms.
AVIATION...
Convection has pretty much gone as forecast, with development
occurring in the interior. This trend is forecast to continue,
and looks to remain mostly inland from KAPF as well. Have removed
most mention of weather from TAFs as there is too much
uncertainty, except a chance of showers and KPAF after 00z.
Otherwise, VFR through the TAF period, except brief IFR under
heavy showers possible.
&&
.PRELIMINARY POINT TEMPS/POPS...
West Palm Beach 78 90 78 90 / 20 30 20 30
Fort Lauderdale 80 89 79 90 / 20 30 10 20
Miami 79 90 79 91 / 20 30 20 30
Naples 76 91 75 91 / 30 50 20 40
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...None.
AM...None.
GM...None.
&&
UPDATE...27/JT
DISCUSSION...27/JT
MARINE...27/JT
AVIATION...54/BNB
Area Forecast Discussion
National Weather Service Spokane WA
827 PM PDT Sat Jul 1 2017
.SYNOPSIS...
Warm and dry weather is expected through the Fourth of July. Hot
high pressure is expected to build over the region Wednesday
through Friday, bringing middle 90s to near 100 degree
temperatures for the second half of the week.
&&
.DISCUSSION...
Update: A weak short wave trough over eastern Washington and
north Idaho this evening will exit overnight with drier air aloft
moving into the area. Just enough elevated instability with this
trough that a stray thunderstorm developed at 8 pm near Chewelah.
This activity should dissipate this evening after sunset with the
loss of daytime heating. Elsewhere storms are more prevalent in
NE Oregon must most of this activity should stay south of the
Washington Blue Mountains and Camas Prairie this evening where the
best elevated instability exists. Still just enough instability
further north to keep a slight chance of thunderstorms through
the evening for the Blues and Camas Prairie. JW
&&
.AVIATION...
00Z TAFS: Isolated thunderstorms will continue south of KLWS over
NE Oregon this evening. Latest HRRR suggests storms should stay
far enough south that an outflow boundary is unlikely to reach as
far north as KLWS but will continue to monitor. Otherwise expect
clearing skies overnight which will persist into Sunday as drier
air moves over the region. Also...breezy/gusty winds will also
impact KEAT after 01z this evening.
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 61 88 60 87 59 89 / 0 0 0 0 0 0
Coeur d`Alene 57 86 57 85 55 87 / 0 0 0 0 0 0
Pullman 57 86 58 84 55 87 / 10 0 0 0 0 0
Lewiston 63 93 62 93 62 95 / 10 0 0 0 0 0
Colville 54 89 55 88 52 91 / 0 0 0 0 0 0
Sandpoint 52 85 52 83 49 85 / 10 0 0 0 0 0
Kellogg 55 85 55 82 53 86 / 0 0 0 0 0 0
Moses Lake 57 93 59 92 58 93 / 0 0 0 0 0 0
Wenatchee 62 91 62 88 61 91 / 0 0 0 0 0 0
Omak 57 92 56 90 56 92 / 0 0 0 0 0 0
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
Area Forecast Discussion
National Weather Service Pittsburgh PA
906 PM EDT Sat Jul 1 2017
.SYNOPSIS...
After a front crosses the region this evening, lower humidity
and dry weather can be expected until Monday.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
Convective development along an eastward-moving cold front this
evening has been meager at best. Somewhat subdued insolation,
lower dewpoints as compared to yesterday, and earlier rainfall
yielding an extended cloudy period this morning probably did
not help matters. However, a few paltry cells did manage to pop
along it through the early evening hours. The area along the
front of most concern has been where it has intersected the
lake breeze boundary as a right entrance region of the upper
jet, lake breeze boundary, and surface front all have
essentially coincided. This has produced a few cells that have
mustered enough vertical depth to produce a few wind gusts,
however as they track away from the best intersection of forcing
and instability wanes into the latter half of the evening, they
too will die off.
The better convective development early in the evening was
actually post-frontal. This has been due to the cold push aloft
lagging the surface front by quite a bit. This is evidenced by
the thermal gradient at 700 and 500 hPa on the RAP indicating
enhanced mid-level lapse rates would be several counties behind
the current surface frontal position. However, here too, the
setting sun has all but eviscerated updrafts already at this
hour, and additional strengthening is not anticipated. Fries
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/...
The next front affecting the region will hover near Lake Erie
Sunday night, slowly drop across the forecast area Monday, and
linger across southern counties Monday night into Tuesday. With
a lack of deep moisture, unsure as to just how much coverage
there will be with precipitation that develops. Have continued
with a diurnal trend, allowing chance pops during the daytime
and slight chance each night. Temperatures will remain near
normal.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
The stationary front will be shunted east by an approaching low
pressure system from the west. While there are still the usual
model differences between strength and timing of the front,
elected to add likely pops Wednesday night into Thursday. Have
maintained lower chances of rain in the forecast continuing
Thursday night into Friday. With no major changes in airmass,
temperatures will stay stable around seasonal temperatures into
next weekend.
&&
.AVIATION /01Z SUNDAY THROUGH THURSDAY/...
Outside of a few storms in the vicinity of FKL and MGW, VFR
conditions are expected to prevail with diminishing cumulus with
the loss of heating. Some model guidance suggests fog
development, but think if this materializes, it will be
patchy river valley fog with minimal impact to the terminals.
Thus, building surface ridge should support VFR through the 30
hour TAF period.
.OUTLOOK...
The next general restriction chance is expected with a
reinforcing cold front on Monday.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...None.
OH...None.
PA...None.
WV...None.
&&
$$
Area Forecast Discussion
National Weather Service Pocatello ID
203 PM MDT Sat Jul 1 2017
.DISCUSSION...Tonight through Saturday. Cloud cover working into
the western portions of the state this afternoon per satellite
imagery. Expect some destabilization to occur later this afternoon
into this evening for a threat of thunderstorms. Have kept slight
chance for thunder over most higher elevations, but HRRR
remarkably consistent today that the main threat will be from
convection developing over NV and shifting northeast into the
South Central Highlands, shifting north toward the Eastern Magic
Valley and weakening as the region continues to spread across the
Snake Plain. Isolated wind gusts up to 40 mph remain possible,
but do not expect severe gusts at this point. Upper trough lingers
Sunday, with a potential repeat in convection. Threat should be
limited to the eastern half of the forecast area, and mainly over
higher elevations. Upper ridge rebounds Monday through the
remainder of the week, with center of upper high located over the
four corners region. This continues to be a favorable pattern for
moisture to work north through the Great Basin, and the threat for
afternoon dry thunderstorms continues each day especially mid
week and beyond. It will be difficult to pin down the location for
development, so made very little change to expected precip
chances later in the week. Otherwise, the impact concern this week
remains with the increased temperatures, especially Tuesday and
beyond. So far, Thursday and Friday appear to be the hottest of
the week with temps likely approaching triple digits in many lower
elevations. Warmer overnight lows could exasperate conditions,
especially for people sensitive to increased heat. Cloud cover
from thunderstorms may be a mitigating factor, but this will be a
potential threat to keep an eye on as we move toward mid week. DMH
&&
.AVIATION...A weak storm crosses the state in the next 24 hours,
spawning a few storms here, there and yonder over the mountains. At
the moment, KSUN and KDIJ would stand to be the most impacted. KIDA,
KPIH and KBYI COULD see impacts if storms happen to wander across
the Plain or adjacent terrain. Little rain and gusty winds over
25kts can be expected IF a cell passes over a given airport. Keyes
&&
.FIRE WEATHER...A weak storm crosses the state in the next 24 hours,
kicking off isolated dry storms over the mountains. Right now, the
Snake Plain looks dry BUT outflow (30+mph) from storms could move
out into the Plain and produce strong winds or even try to kick off
a storm or 2. The rest of next week should be very warm with low
humidities with very strong high pressure building across the
Rockies. Highs by midweek will be pushing 95-100 at lower elevations
and 75-85 in the mountains. Humidities will drop to 10-20% for the
Snake Plain and other low valleys and upper teens to mid 20s at
higher elevations. We will see inversions at night so mid/upper
slopes will remain quite dry. We WILL NOT be storm free though it
appears. Limited monsoon moisture works around the ridge for
possible isolated (and dry) storms over higher terrain. It will be
hard to pinpoint which ranges will see storms each day at the
moment, but the possibility is there each day. Keyes
&&
.HYDROLOGY...Rivers across East Idaho have shown a definite
downward trend over the past week with peak flows now likely
behind us. Some lingering issues remain at a few locations,
however. It remains to be seen how much impact the hot
temperatures this week will have on the rivers. Some increase is
expected in the basins of the Tetons, the Big Lost and in the
Central Mountains by later in the week. DMH
&&
.PIH WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
Area Forecast Discussion
National Weather Service Pueblo CO
251 PM MDT Sat Jul 1 2017
.SHORT TERM...(This evening through Sunday)
Issued at 239 PM MDT Sat Jul 1 2017
An upper level ridge will be building over the state through
tonight, but a weak disturbance will flatten the ridge Sun
afternoon. For this evening, it looks like isolated to scattered
showers/tstms will be seen over the southwest mtns, San Luis Valley
and the Sangre de Cristo mtns, with isolated to scattered
showers/tstms being possible over the Wet mtns, Pikes Peak area and
the I-25 corridor. Then by late evening the NAM and the HRRR show
some storms moving out over the far sern plains, mostly ending by 1
am.
Sun morning looks dry acrs southern CO, with storms then developing
over the mtns in the early afternoon and possibly spreading to the
adjacent lower elevations. Temps in the high valley areas on Sun
look like they will be similar to today. Over the southeast plains,
temps should be warmer than today by several degrees.
.LONG TERM...(Sunday night through Saturday)
Issued at 239 PM MDT Sat Jul 1 2017
Not much change to the forecast thinking through the extended
period. Models are in good agreement and ensemble spreads are low
leading to continued higher confidence forecast.
Sunday night through Tuesday...high pressure will begin building
northward out of the Desert Southwest and across Utah through this
period. A slow moving upper disturbance over Eastern Colorado into
Western Kansas will keep flow northwesterly.
Expect ongoing showers and thunderstorms Sunday night rolling off
the mountains and across the Plains through the evening hours.
Favored areas continue to look like the Palmer Divide and Raton
Mesa. A few storms could become strong to near severe levels with
hail approaching 1 inch in diameter and 60 mph winds. This
activity should dissipate through the evening hours with dry
conditions heading into Monday morning.
Very similar conditions are expected to prevail Monday and
Tuesday. Thunderstorms are forecast to develop over the mountains
areas during the early afternoon hours, and spread eastward into
the Plains through the evening hours. Again, favored areas look to
be over the Palmer Divide and Raton Mesa. A few storms may become
strong to severe. Activity should dissipate through the evening
hours each day with dry conditions heading into the morning hours.
Wednesday through Saturday...high pressure will build across
Colorado and persist into next weekend. This will bring hot
temperatures to southern Colorado with afternoon highs in the 90s
each day. Expect daily afternoon and evening showers and
thunderstorms over the mountains. Lack of steering flow should
keep convection anchored to the terrain, with little or no
movement into the adjacent plains. Locally heavy rainfall may be
possible with stronger cores. Gusty outflow winds will be the
other main threat in addition to lightning. Mozley
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 239 PM MDT Sat Jul 1 2017
VFR conditions are expected thru the next 24 hrs at KCOS, KPUB and
KALS. There is the possibility of some showers/tstms in the vicinity
of the terminal forecast sites this evening, and again on Sun
afternoon.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...28
LONG TERM...MOZLEY
AVIATION...28
Area Forecast Discussion
National Weather Service Reno NV
412 PM PDT Sat Jul 1 2017
.UPDATE...
We will do a minor update to add isolated activity this evening
over far northern parts of the forecast area across
Mineral...southern Lyon and far eastern Mono counties where
vertical development of convection will be maximized due to
forcing and differential heating...respectively. There may be
little if any precipitation with this convection...possibly just
gusty winds and dry lightning.
&&
.PREVIOUS DISCUSSION... /Issued 306 PM PDT Sat Jul 1 2017/
SYNOPSIS...
High pressure will build over northeast California and western
Nevada for dry conditions and above average temperatures through
the 4th of July. High pressure will move to over the Rockies and
Four Corners mid to late next week for an increase in thunderstorm
chances. Typical afternoon and evening breezes are expected for
the next week.
SHORT TERM...
Lift/forcing with a trough axis moving over far western Nevada
this afternoon is inducing high clouds over west-central and
central Nevada. As far as moist convection, daytime heating is
working on convergence boundaries over Mineral, and Lassen and
northern Washoe Counties to bring some high-based cumulus...with
deeper (but still modest) convection so far limited to near Lassen
Peak. The HRRR and NAM simulations indicate isolated, small
convective cells over southern and eastern Mineral, as well as
near the Churchill, Pershing, and Lander County border into
evening. Currently, the webcam looking east from Mono Lake
indicates modest vertical development to the cumulus over Mineral
County. Given only modest growth, we will not add thunderstorms at
this time. However, a few cumulus could grow deep enough towards
evening to bring virga or a few raindrops east of Highway 95 and
near/south of Highway 50.
Sunday and Monday, a ridge axis over the eastern Pacific expands
into California and Nevada. This is expected to bring sufficient
subsidence to keep any afternoon cumulus vertically restricted
with only a 5-10% chance for showers or thunderstorms near the
crest in Alpine and Mono Counties. The Fourth of July is expected
to be hot and dry under the ridge with modest afternoon and
evening breezes. -Snyder
LONG TERM...Wednesday through Saturday...
By next Wednesday, the pattern begins to shift as the upper ridge
axis slides off into the Four Corners and Rockies and an upper
trough drops to well off the California coast. This is expected
to allow slight cooling aloft with a very weak upper wave moving
over the region Wednesday between the trough and ridge. The latest
simulations do not show much in the way of instability or forcing
aloft with the wave. However, the cooling aloft may be sufficient
for isolated thunderstorms originating over Mono and Mineral
Counties to advect north towards Highway 50 and the Pine Nut
Range by late afternoon. IF any thunderstorms do form, they will
be on the dry side as storm-bearing flow indicates a movement of
around 20 mph or so. Also, dry lower layers will encourage strong
outflow winds. This will be a fire weather concern for new fire
starts although currently the coverage looks limited.
Thursday, winds could veer a bit more southwesterly aloft with
some drying per the ECMWF so thunderstorms were left out of the
forecast for consistency sake. However, the GFS is coming in with
more southerly flow with little stabilization so a few storms may
need to be added back into the forecast, especially east of Highway
395 and south of Highway 50.
Friday and Saturday, models are coming together for building the
ridge more strongly overhead as northeast Pacific troughing retreats.
This is likely to allow convection to develop (at least isolated
in Mono-Mineral Counties) with afternoon heating and the possibility
for a mid-level moisture increase from the south. -Snyder
AVIATION...
High pressure will remain with light winds except for the afternoon
zephyr with gusts 20-25 kts 22-04Z each day through Tuesday. VFR
conditions expected. A few cumulus buildups are possible near the
Alpine and Mono County crest Sunday and Monday...but thunderstorm
chances remain low at 5-10%. -Snyder/Wallmann
&&
.REV Watches/Warnings/Advisories...
NV...None.
CA...None.
&&
$$
For more information from the National Weather Service visit...
http://weather.gov/reno
Area Forecast Discussion
National Weather Service Blacksburg VA
831 PM EDT Sat Jul 1 2017
.SYNOPSIS...
Weak surface cold front across the Ohio Valley will drift
southeast toward the region tonight before spilling just south
of the area Sunday afternoon. This along with residual outflow
may result in scattered showers and storms into this evening.
The boundary looks to stall over the Carolinas Sunday night into
Monday ahead of another weak cold front that may arrive from
the northwest by the middle of next week.
&&
.NEAR TERM /THROUGH SUNDAY/...
As of 830 PM EDT Saturday...
Made some changes to the pops for the overnight hours and
through the afternoon Sunday to better reflect current radar
trends and expected focus of convection near and south of
lingering baroclinic zone/dewpoint discontinuity boundary near
our southern CWA border. Removed pops from northern areas
Sunday. Convective activity overnight should remain mostly
southwest of a Marion to Martinsville line. T/Td readings were
basically on track, with dewpoints still in the low 70s across
our NC counties and the VA Piedmont, 60s west of the Blue Ridge.
No other significant changes at this time.
As of 215 PM EDT Saturday...
Isolated showers/storms currently along the southern Blue
Ridge/foothills, associated with an earlier residual outflow
band, should continue to spill east before exiting the region
late this afternoon. Appears given downslope and only weak upper
support that only a limited severe threat will exist as a few
perhaps become stronger upon moving into better instability east
of the mountains. May also see added isolated thunder redevelop
mainly west per ongoing convergence through early evening so
running with chance pops overall. Guidance then pushes an
upstream band of convection ahead of the actual cold front along
the Ohio River east with some of this perhaps reaching the west
during the evening. This remains uncertain, but given lingering
instability and a decent shortwave aloft passing across, will
hold some low pops in mainly mountains through around midnight.
Otherwise should see most clouds fade except perhaps some low
deck west/southwest per westerly flow and fog where
afternoon/evening showers occur. Lows very muggy outside of any
cooling evening showers with 60s west to only around 70 east.
Weak surface front will slip south into the area Sunday, likely
stalling across southern sections late in the day. Models suggest
enough drying aloft as seen on forecast soundings to limit
convection espcly north of Highway 460, while keeping moist
PWATS stuck across the south. This is where another weak wave
aloft may arrive along the base of the upper trough by late
afternoon. This along with decent forecast instability suggests
the need for some low pops espcly from the southern Blue Ridge
east given only weak westerly flow and in line with the latest
ensembles. Otherwise will run with low pops west early,
increasing to scattered/isolated southern sections during the
afternoon. Should see any early fog/stratus break for more
sunshine with temps quite warm/hot with highs 80s west, and
around 90 east per aid of weak downsloping under continued 850
mb temps of near +19C.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/...
As of 205 PM EDT Saturday...
High pressure builds in behind a weak cool front Sunday night. This
ridge with zonal flow aloft will keep the area dry into Tuesday
morning. Dew points also drop into the upper 50s to lower 60s
following the frontal passage Sunday night. Overnight lows will
range in the 60s.
Warm air advecting in on zonal flow plus abundant July sunshine will
help temperatures run warmer than normal Monday. High temperatures
will be in the 80s with lower 90s likely across the piedmont.
Humidity levels will also be on the increase Monday night as dew
points creep up into the 60s. A back door front along the Mason-
Dixon line may also increase cloud cover Monday night into Tuesday
morning. This blanket of clouds and increase humidity will keep
Monday night on the muggy side with lows in the mid to upper 60s.
Lowering heights as a back door front approaches the area from the
north may bring a chance for scattered showers and thunderstorms
into the region Tuesday afternoon. With the addition of orographic
lift, the mountains will see the first storms fire during the
afternoon, then they will drift eastward over the foothills by
sunset, and across the piedmont during the evening. Any storms that
develop Tuesday will fade with lose of heating by midnight.
Tuesday`s afternoon temperatures will warm around 5F above normal
with lower to mid 80s across the mountains and lower 90s east of the
Blue Ridge into the piedmont.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
As of 220 PM EDT Saturday...
An upper level disturbance is forecast to track from the Great Lakes
on Wednesday to Lake Erie on Thursday. Being in the warm sector on
Wednesday, one can expect your typical scattered diurnal afternoon
and evening thunderstorms. The trailing cold front from this
disturbance will bring a good chance for showers and thunderstorms
into the region on Thursday. Weak subsidence behind the front should
keep the region dry Friday. Another front is expected to track
across the region next weekend.
Afternoon temperatures will remain at or above normal going into
next weekend.
&&
.AVIATION /01Z SUNDAY THROUGH THURSDAY/...
As of 750 PM EDT Saturday...
Generally looking for VFR conditions through the period with a
few exceptions. While the actual frontal boundary lags back to
our west in OH/KY, a notable dewpoint boundary extended from
Southside VA into western North Carolina. In general the
convection has been focused along and near this boundary and is
definitely showing signs this hour of diminishing. HRRR
suggests that convection will continue to diminish through the
evening with little additional activity expected over night.
Largely convection will focus along and south of the I-40
corridor through most of the TAF valid period. While some
convection may develop closer to the baroclinic zone across
NC/TN Sunday afternoon, not expecting this to be near enough
even to KDAN to include in the TAF at this point.
The main concern for any non-VFR conditions overnight will be
from low clouds and fog. Upslope west winds could result in
several hours overnight into the morning hours Sunday of low
MVFR cigs across eastern WV. While this has not yet developed,
the synoptic pattern is favorable for such and is suggested by
several of the model and MOS outputs. Will include MVFR cigs for
several hours at KBLF and KLWB in the 06Z to 13Z time frame.
Elsewhere, light MVFR BR could develop, but confidence in low.
Greater potential for such across the Piedmont (e.g., KLYH and
KDAN, if the temperature can cool close to the dewpoint, which
given dewpoints are in the low to mid 70s, that seems possible).
After 14Z Sunday, looking for VFR conditions at all TAF sites.
Winds will be mostly WSW-WNW 4-7kts overnight and 7-11kts Sunday
after 14Z with some low end gusts possible at KBLF, KBCB, and
KROA during the late morning to mid-afternoon Sunday.
Medium confidence in ceilings and visibilities through 14Z,
then high confidence in VFR cigs and vsbys through the remainder
of the TAF valid period. Medium to high confidence in wind
speed/direction through the TAF valid period.
Extended Aviation Discussion...
A weak frontal boundary or baroclinic zone will reside just to
our south through much of the first half of the week. This
should limit afternoon convection to areas south of the TAF
sites, but some convection near the I-40 corridor in NC is
possible. The boundary is expected to begin to creep back north
slowly into July 4th. Upstream disturbances will likely impinge
upon the moisture and frontal boundary to result in an increase
in afternoon/diurnally driven convection. Periods of MVFR cigs
will be possible in this activity, most numerous initially
closer to the NC/VA border, but likely impacting all areas as
the week progresses. Late night and early morning fog can also
be expected with increasing probability through the week,
especially given the increasing potential for late day/evening
rain at many TAF sites. Convection may become more numerous
toward the end of the week as a stronger upper-level system
approaches from the west. All-in-all, likely to be an unsettled
week, but periods of VFR can certainly be expected.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...None.
NC...None.
WV...None.
&&
$$
SYNOPSIS...JH
NEAR TERM...JH/RAB
SHORT TERM...RCS
LONG TERM...RCS
AVIATION...JH/RAB
Area Forecast Discussion
National Weather Service Shreveport LA
1026 PM CDT Sat Jul 1 2017
.UPDATE...
Pops for the late evening and overnight and bump lows down.
&&
.DISCUSSION...
KSHV Doppler Radar is still showing some new development on old
boundaries and cool pool intersections. The upper levels is
helping too with some decent lift, but we are fairly worked over
from the afternoon blow up. As the upper energy departs stage
right (East) the chance for additional rainfall with go along with
it. We have a large cool pool of low to mid 70s with the need for
some new numbers being cooler now than forecast in a handful of
spots too. The HRRR has been out to lunch or late here lately,
but the 18Z runs were better for the overnight. The new Nam is
even showing some quarter and half inch bullseyes around 09z
along I-20. /24/
&&
.PREV DISCUSSION... /issued 644 PM CDT Sat Jul 1 2017/
AVIATION...
VFR conditions this evening will become MVFR and eventually IFR
overnight across area terminals. Conditions to gradually improve
to VFR after 02/15Z. VCTS conditions may be possible across TXK
around 02/10Z. Otherwise, surface winds 5 knots overnight to
become South to Southwest 5-12 knots on Sunday. /05/
PREV DISCUSSION... /issued 415 PM CDT Sat Jul 1 2017/
DISCUSSION...
Cold pool cluster of tstms organized btwn TYR and GGG and
accelerated ene into sw AR and extreme north LA. Airmass will be
worked over into the early eve behind these storms, yet models
strongly hinting at convective redevelopment. Will leave in 30
pops northern cwa this eve which does not include current activity
movg thru. Upper ridge will begin to build into the area on
Sunday, with frontal boundary just north of I-20 to begin lifting
nwd and will leave low pops in northern sections of area on
Sunday. Thereafter, pops to remain very low with upper ridge, with
northern fringe of area enhancements dependent on evolution of
ridge, as nw flow around topside may bring either diurnal
overnight mcs near the area, or possible aftn development. Aftn
temps to continue in lower to mid 90s, and may creep slightly
upward thru the 90s thru the 4th of July Holiday wknd, although
dewpoints in mid to upper 70s may lower just slightly. Nearly on
the fence with LWA issuance, especially being a holiday wknd, but
will give one more day for trends to set up after this current
temporary convective induced cooling. Towards mid week, this upper
ridge to begin to break down and southerly flow will deepen,
allowing for isold to sct convection areawide./07/
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 73 94 75 95 / 40 10 10 10
MLU 71 95 74 96 / 30 20 10 10
DEQ 73 90 73 92 / 40 30 20 20
TXK 71 93 75 93 / 40 20 20 10
ELD 70 94 74 93 / 50 20 20 10
TYR 73 93 75 95 / 20 10 0 10
GGG 72 94 74 95 / 30 10 0 10
LFK 74 94 74 96 / 20 10 0 10
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...None.
LA...None.
OK...None.
TX...None.
&&
$$
24/05/07
Area Forecast Discussion
National Weather Service San Angelo TX
628 PM CDT Sat Jul 1 2017
.AVIATION...
/00Z TAFS/
Look for challenging flight weather later tonight. Stratus will
again return to most of West Central Texas later tonight and bring
MVFR ceilings. By 12Z, most locations south of our Interstate 20
corridor, should be under MVFR ceilings. However, VFR conditions
will dominate all of West Central Texas by 16Z.
&&
.PREV DISCUSSION... /issued 338 PM CDT Sat Jul 1 2017/
SHORT TERM...
(Tonight and Sunday)
A well developed cumulus field has formed west of a Mertzon to
Junction line at 3 PM. If a storm develops in the next couple
hours, it should be short-lived. HRRR and Texas Tech WRF indicate
a MCS to move east out of New Mexico tonight, possibly affecting
areas north of I-20 as it weakens and dissipates. The main impacts
from the storms will be strong gusty winds and dangerous
lightning. Dry conditions are expected Sunday as upper ridging
builds in. Highs will be in the mid and upper 90s with lows in
the lower 70s. A few areas in the Concho Valley could hit 100.
Mid-morning low clouds may affect areas along the I-10 corridor,
but otherwise mostly sunny conditions expected.
$$
04
LONG TERM...
(Monday through Saturday)
Not much change expected through the extended forecast as hot
temperatures continue across the area. The upper ridge will remain
over west Texas, with a series of weak shortwave troughs rotating
around the top and east of the ridge across the Panhandle and
north Texas. We could continue to see a small chance of rain with
each of these shortwaves during the weak as thunderstorms develop
in the Panhandle in northwest flow aloft and head south toward our
northern counties. We left a slight chance of thunderstorms in
the forecast mainly for July 4 (Tuesday afternoon and Tuesday
night), and also Wednesday and Wednesday night. Otherwise, days
should remain hot with temperatures in the upper 90s to around 100
degrees.
08
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 75 96 74 98 / 10 5 0 5
San Angelo 74 99 74 99 / 10 5 0 0
Junction 73 95 72 96 / 5 5 5 0
Brownwood 73 96 72 97 / 10 5 0 0
Sweetwater 73 96 74 97 / 10 5 0 5
Ozona 72 95 72 96 / 10 5 5 5
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
For frequently asked questions about the Area Forecast Discussion
visit...
http://weather.gov/saltlakecity/general/afd_faqs.php
Area Forecast Discussion
National Weather Service Tulsa OK
839 PM CDT Sat Jul 1 2017
.DISCUSSION...
After coordination with neighboring offices, and after perusing
the latest hi-res CAM solutions, thunder chances have been
removed for the remainder of the night. Convection out west, even
if it were to survive, would likely not make it this far east by
12Z. Updated products sent.
Lacy
&&
.PREV DISCUSSION... /Issued 757 PM CDT Sat Jul 1 2017/
DISCUSSION...
It was a relatively tranquil afternoon compared to yesterday at
this time. A few isolated, short-lived thunderstorms developed
along the old synoptic front across NE OK/NW AR, and over the
elevated terrain of SE OK. All of this activity has dissipated,
and with the loss of daytime heating and lack of forcing the
evening hours should be quiet. Will wait and see how the
convection out on the high Plains evolves tonight. Seems possible
that this convection will die to our west, but persist long enough
to generate an MCV, as the HRRR is suggesting. This MCV would move
east and combine with daytime heating to provide a focus for more
thunderstorm activity over our area on Sunday afternoon. The
forecast was updated to remove PoPs for the evening hours, and the
small PoPs for after midnight were left intact, just in case the
convection out west makes it into eastern OK before dissipating.
Lacy
PREV DISCUSSION... /Issued 646 PM CDT Sat Jul 1 2017/
AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM/KROG.
Scattered mid/high clouds this evening should continue to decrease
overnight with light and variable winds common. By early morning
Sunday...some areas of IFR/MVFR conditions could be possible
across parts of Northwest Arkansas and will continue tempo groups
for these TAF sites. Also...increasing mid/high clouds could be
possible over Northeast Oklahoma late tonight as a potential MCS
approaches the region. Any precip overnight should remain isolated
in coverage and will keep sites dry. During the day Sunday...VFR
conditions are forecast across the CWA by mid/late morning with
possible thunderstorm chances for the late morning and afternoon
hours. Will continue prob30 groups north of Interstate 40 for
precip timing Sunday.
PREV DISCUSSION... /Issued 304 PM CDT Sat Jul 1 2017/
DISCUSSION...
The isolated thunderstorms that developed in the vicinity of the
old synoptic cold front over northeast Oklahoma and northwest
Arkansas have pretty well faded. Would not be out of the question
to see an isolated thunderstorm develop near this eroding feature
during the evening hours. Could also see an isolated thunderstorm
or two this evening across southeast Oklahoma into western Arkansas
as an MCV treks across northeast Texas. Additional thunderstorms will
be possible late Tonight into Sunday morning across portions of eastern
Oklahoma as MCSs approach from the west and northwest.
Sunday will see more isolated to scattered showers and thunderstorms
even as the front moves to the north of the area as a warm front.
Any boundaries left over from the overnight convection will aid in
this development. There is also the potential for another MCS to develop
over Kansas and approach the area late Sunday night into Monday morning.
Scattered showers and thunderstorms will be possible early to mid-week
as a mid-level shortwave slowly moves from the plains into the mid-Mississippi
Valley.
By late week, a large upper level ridge will become established over the
western United States resulting in warmer temperatures as we move into
next weekend.
&&
.PRELIMINARY POINT TEMPS/POPS...
TUL 71 90 74 91 / 10 40 30 30
FSM 72 91 74 91 / 10 30 20 30
MLC 72 90 75 91 / 10 30 20 20
BVO 67 88 71 91 / 10 40 30 30
FYV 66 85 71 87 / 10 50 30 40
BYV 66 86 70 86 / 10 50 50 40
MKO 71 88 73 90 / 10 50 20 40
MIO 67 88 70 89 / 10 50 40 50
F10 70 89 74 91 / 10 40 20 30
HHW 72 91 75 92 / 10 20 10 10
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...None.
AR...None.
&&
$$
LONG TERM....30