Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 07/15/18
Area Forecast Discussion
National Weather Service Binghamton NY
811 PM EDT Sat Jul 14 2018
.SYNOPSIS...
A couple rounds of storms tonight as weak disturbances move
through. A slight chance for storms lingers Sunday with
warm and moist conditions, then Monday turns even warmer
with our best chances for storms Monday night into Tuesday
ahead of a cold front. This moves out by early Wednesday
with high pressure bringing in sunny and quiet weather for
the rest of the work week.
&&
.NEAR TERM /THROUGH SUNDAY NIGHT/...
8 pm update...
Fairly widespread convection developed this evening within a
modestly unstable and low sheared environment. A very moist air
mass within a w/nwly flow has supplied the moisture for these
storms with the main threats being strong winds from wet
microbursts, and locally heavy downpours. The main area of
attention continues to be the Elmira/Corning corridor and just
to the south of there where radar estimates of rainfall are
around 1 to 2 inches in the past 3 hours or so. The back edge of
the main batch/heaviest rain is pushing through with a second
wave and possibly another 0.5 to 1 inch of rain this hour. So
far now hydro issues due to the lack of recent rainfall...so
soil conditions are fairly dry, but if any additional rain, or
more rain than expected arrives tonight, there may be issues in
this area.
There is still some uncertainty about what will happen later
tonight, but given all the convection this evening...it is
likely that the atmosphere will be lacking any instability to
support additional widespread storms. Latest HRRR and NAMNest
indicating a trend toward minimal convection tonight along the
upper s/w. However can`t rule out scattered rain showers with a
few weak storms popping up through tonight along and south of
the Twin Tiers.
Previous Discussion...
For the rest of this afternoon and this evening, a convectively
induced wave which was more defined this morning was moving
toward NY and northern Pa. Visible satellite imagery (red band)
shows strong insolation in NY and Pa which will continue to
destabilize the atmosphere across central NY and northeast Pa. We
expect mixed layer CAPEs to reach close to 1000 J/kg by the time
the wave begins to influence our forecast area from late
afternoon into the evening. 0-6 km bulk shear magnitudes were
between 25 and 30 knots with weaker shear below this layer. The
effective shear was between 30 and 45 knots in the eastern lakes
with this approaching wave presently as per SPC mesoanalysis.
Our local severe weather checklist gave us several wind damage
events. DCAPEs were running 700-800 J/kg with low-level lapse
rates 7.5 to 8 C/km suggesting potential for some decent wind
gusts probably in the 40-50 mph realm with a small chance for
severe wind gusts. This could be a situation where it won`t take
as deep convection to produce stronger wind gusts because of
the DCAPE and continuing steepening low-level lapse rates. So we
have mainly likely POPs between about 21z and 03z from
northwest to southeast across our forecast area. We have
potential for strong wind gusts in our HWO and also our one
slide DSS briefing.
After 03z, the NAMnest suggests another round of convection
fires as another short wave seen on the water vapor imagery in
the northern lakes drops southeast behind this more convectively
induced wave. We continue POPs for showers and thunderstorms
well into the night to account for this. If this next batch
becomes more extensive then we will have to be concerned for
localized flood potential. There is uncertainty related to this
as the NAMnest now indicate a very progressive looking broken
line of storms. The HRRR also suggests more progressive storms.
Precipitable water values are around 1.75 inches. So we did
continue mention of locally heavy rainfall for all storms late
afternoon through this evening at least in HWO, grids and our
one slide DSS briefing.
For Sunday, there will be a left-over boundary which could be
convectively induced in the vicinity of the NY/PA border.
Another mid-level wave(Illinois MCV?) will move toward NY and
PA and provide more lifting to trigger more showers and storms
with a focus on the stalled boundary. So we continued slight
chance to chance POPs with the highest POPs in northeast
Pa/southern Tier of NY. One again, CAPES will be decent and
potentially higher than today with the NAM having mixed layer
CAPEs over 2000 J/kg. Bulk shears 0-6 km are fairly weak though.
Precipitable water values are a bit higher pushing 2 inches
suggesting again locally heavy rainfall. There is more
uncertainty Sunday because the convection that will influence
this mid-level wave is still forming. SPC has area in general
thunder so we will not enhance wording at this juncture. WPC
also does not have our area in any flash flood risk as well.
Sunday night, upper level ridging builds in and we dry things
out. However, convectively induced waves could mess this up but
we will hold course on less than 15 POPs for now looking at the
4 main synoptic models and the positioning of the upper level
ridge axis overhead and to our east.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
Our region will be in a southwest flow pattern with a cold front
to the west and a high pressure system off the east coast on
Monday. Warm and moist air will continue to advect into the
region. Operational models and the respective ensembles are
fairly consistent with a frontal timing on Tuesday. Moisture
and lift will be sufficient enough to produce showers and
thunderstorms ahead of the front. The highest chances for
showers and storms continue to be Monday night and Tuesday and
we continued likely pops. PW values look to rise to around 2
inches, so we have added heavy rain wording to the forecast with
the storms. Instability and shear both look on the marginal
side for any strong to severe storms along with poor frontal
timing for any severe event. Temperatures have trended upward
Monday given modeled 925 mb temperatures around 25C should get
many locations near or even slightly above 90. With the added
humidity, locations from the Finger Lakes and Elmira northeast
toward Syracuse and Rome may see top heat index values near 95.
We have added wording to the HWO for this possibility. Lows
will be muggy both Monday night in the 60`s.
Cooler and drier air will come in behind the front later on
Tuesday with a slow decrease in storms from west to east
throughout the day. Highs should cool back into the 70`s and low
80`s with lows Tuesday night generally falling back into the
50`s to around 60. Winds look to be around or under 10 mph
outside any thunderstorms.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
Showers and storms move out of the SE portions of our area by
early Wednesday morning as the cold front pushes to our east and
high pressure begins to build in. Drier air working in will
allow for a return to mostly sunny skies by the late
morning/afternoon Wednesday. High pressure remains in control
Thursday and Friday, with sunny and quiet conditions.
Temperatures in the 70s to around 80F Wednesday, then as winds
gradually turn over to the south temperatures increase into the
upper 70s and low 80s Thursday and the low/mid 80s Friday.
Our next real shot at rain returns Saturday. High pressure
makes an exit, with southerly flow bringing in a warmer and more
moist airmass. The GFS brings in a trough that will leave us
with some scattered showers and storms. The ECMWF, meanwhile,
tracks a surface low NE through the eastern Great Lakes and into
Canada, with more widespread rain. This seems a bit
overzealous, so went more with the GFS solution of lower chances
for rain and thunder and slightly higher afternoon
temperatures.
&&
.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
Showers and thunderstorms are possible form KELM to KBGM through
about 03Z...and from about 02Z to 05Z at KAVP. Northern
terminals KSYR and KRME should remain dry...with rain showers at
KITH through 03Z. Not enough confidence to mention precip later
tonight. Will likely be mostly dry with only temporary periods
of rain showers. Will also need to watch for the potential of
fog later tonight. Current forecast keeps all sites VFR after
06Z tonight through 00Z Monday.
Winds will be light and variable tonight through the day Sunday.
Outlook...
Sunday night through Monday...Mainly VFR, but still a small
chance for primarily daytime showers and thunderstorms.
Monday night through Tuesday...Restrictions likely in showers
and thunderstorms.
Tuesday night through Thursday...Mainly VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...None.
NY...None.
&&
$$
SYNOPSIS...HLC/MWG
NEAR TERM...BJT/DJN
SHORT TERM...MWG
LONG TERM...HLC/MWG
AVIATION...BJT/DJN
Area Forecast Discussion
National Weather Service Dodge City KS
530 PM CDT Sat Jul 14 2018
...Updated aviation section...
.SHORT TERM...(This evening through Sunday)
Issued at 318 PM CDT Sat Jul 14 2018
A weak upper level shortwave was slowly moving southeast over
western Kansas this afternoon with the axis currently extending
roughly from Wakeeney to Liberal. Latest short term models show this
shortwave moving a little more to the southeast before washing out.
At the surface, a weak stationary frontal boundary was located
along the Oklahoma border and this is where the best low level
moisture convergence is occurring this afternoon. Short term CAMs
like the HRRR and RAP13 have been pretty consistent over the past
several runs in developing some isolated to widely scattered
thunderstorms along and/or south of Highway 54 later this afternoon
and early evening. Latest visible satellite trends would support
that as the cumulus field is becoming a little more congested over
Meade Co. The current forecast has a pretty good handle on this
and will continue to follow it with a few minor tweaks. Thunderstorms
are expected to diminish fairly quickly this evening as we lose
daytime heating. Some patchy fog could redevelop again later tonight
given the weak moist low level upslope flow into western Kansas.
There will be a slight chance for thunderstorms again with peak
heating on Sunday afternoon. Best chances will be across southern
portions of the forecast area where the old frontal boundary
continues to linger.
.LONG TERM...(Sunday night through Saturday)
Issued at 318 PM CDT Sat Jul 14 2018
Upper ridge over the central High Plains gets displaced somewhat
farther south through the first part of the upcoming week. With
the southern edge of the mid level westerly flow moving back to
the south, western Kansas should see somewhat better chances for
thunderstorms through Tuesday or Wednesday. This will include
the increasing potential for severe thunderstorms along with the
potential for heavy rain given increasing deep layer shear and a
fairly moist airmass. Monday night and Tuesday night could MCSs
developing over the High Plains of northeast Colorado into
northwest Kansas that could impact locations of the forecast area
especially north of Highway 96.
By later in the week both the GFS and ECMWF show the upper level
ridge rebuilding over the western and central CONUS. This could
result in drier conditions for southwest Kansas if enough mid
level warming occurs to keep a lid on convection.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 529 PM CDT Sat Jul 14 2018
VFR conditions will prevail with decreasing mid level cloudiness
this evening. Winds will generally be from the south to southeast
at less than 12 knots.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 68 96 70 92 / 20 20 20 40
GCK 69 94 68 90 / 10 10 10 40
EHA 67 95 68 91 / 20 10 10 30
LBL 69 96 70 93 / 20 10 20 40
HYS 70 94 69 87 / 10 10 20 30
P28 73 97 73 94 / 20 20 20 20
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Gerard
LONG TERM...Gerard
AVIATION...Hovorka_42
Area Forecast Discussion...UPDATED
National Weather Service Gray ME
1100 PM EDT Sat Jul 14 2018
.SYNOPSIS...
A weak trough of low pressure will result in scattered showers
and thunderstorms tonight and Sunday. Weak high pressure over
the area early on Monday will push offshore during the day. This
will result in warm and humid weather with many areas seeing
high temperatures well into the 80s with the possibility of
lower 90s over southern New Hampshire. A seabreeze may develop
along the coast during the afternoon. Isolated showers and
thunderstorms may also develop in the afternoon. A strong cold
front will move through the region Tuesday, bringing widespread
showers and thunderstorms to the region. Cooler and drier
conditions will return for Wednesday Through Friday.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
11 PM Update...
A few minor changes, mainly to lower PoPs across the region.
Short wave will still bring widely scattered showers and
possibly an isolated thunderstorm to the area overnight. The
HRRR is showing an increase in convective activity around 6-8 AM
in southern NH and SW ME. Still expecting showers and
thunderstorms Sunday along a weakening boundary.
915 PM Update...
Scattered showers are moving through southern NH at this hour,
with light showers moving off the southern Maine coast. Made
some adjustments to PoPs, temperatures, and dew points after
ingesting latest observations. Forecast otherwise looks on
track, including the possibility for some patchy fog and drizzle
in some locations.
615 PM Update...
Radar imagery shows increasing convection to our southwest as a
short wave moves towards the region. A few echoes are moving
through New Hampshire and Maine as of 6 PM, producing sprinkles
and a couple showers. As the short wave approaches tonight,
PWATs, which were around an inch on this morning`s KGYX
sounding, will increase to at or above 1.75" over southern NH
and southwest ME. There will be enough elevated instability to
support isolated to scattered thunderstorms, and have added
these to the forecast for tonight and into the morning hours.
These will be garden variety storms with lightning and some
heavy rain.
Fog was added across the region and over the waters with
moisture increasing rapidly. Otherwise temperatures are cooling
faster than forecast, especially across the north, and have
adjusted hourly and overnight low temperatures.
Previous discussion...
Cloudy skies and a few isolated showers will continue through
the evening as a weak disturbance clears off to our east.
Overnight expect some fog to be possible in the mountain valleys
if the upper level clouds are able to clear out of the way in
time. Additionally dewpoints near 60 along the coastal plain
will bring coastal fog to the waters. Fog will linger until just
after dawn.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...
Through Sunday and into Monday increasing heights will see
temperatures rising as south to southwesterly flow advects warmer
more humid air ahead of a stronger system arriving Tuesday. Sunday
will be increasingly humid as dewpoints reach the upper 60s. The
combination of hot and humid conditions will provide enough
instability for some afternoon thunderstorms. These will mostly
be initiated off the terrain as the stronger forcing aloft
remains upstream. Expect scattered afternoon thunderstorms on
Sunday. A few of these may be sustained enough to produce gusty
winds due to the steep low level lapse rates.
Sunday night the increasing humidity will lead to more widespread
fog throughout the region with dense fog possible in the northern
valleys.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
Global models are in good agreement through the period. On
Monday ridging aloft with a surface high at the surface pushing
over the Gulf of Maine will result in a SW flow of warm and
increasing muggy air will develop. Dew points will climb to near
70 over the southern part of the area while reaching the mid
60s over the mountains. The SW flow may not be strong enough to
prevent afternoon seabreezes...so expect some cooling during the
afternoon along the coast. Cannot completely rule out isolated
afternoon showers and thunderstorms over western areas where
instability will increase during the afternoon.
More organized showers and thunderstorms are likely Tuesday as a
cold front crosses the area from NW to SE. Timing of the front
will dictate severe thunderstorm potential. Current indications
are that the front will cross the mountains midday....but not
until late afternoon along the coast. This would make areas
south of the mountains the region to watch for strong to severe
thunderstorm development. There also will be a moisture rich
environment in place with dew points in the upper 60s and lower
70s. Southern most areas may see dew points reach into the mid
70s. This may increase the threat of heavy rain which could
result in a flash flooding threat.
A large area of high pressure will build east from the Great Lakes
region midweek and dominate the weather through Friday resulting in
dry and comfortable conditions.
Low pressure over the Ohio Valley will start to approach
Saturday...however it is too early to tell whether any
precipitation arrive by late Saturday or hold off beyond day
7.
&&
.AVIATION /03Z SUNDAY THROUGH THURSDAY/...
Short Term... MVFR ceilings this afternoon as showers associated
with a weak front move through. Those ceilings will increase
to VFR later this evening. Overnight fog along the immediate
coastline may impact RKD and PWM while further inland HIE and
BML may also fog in resulting in IFR. Sunday clouds and
visibilities will return to VFR but scattered afternoon
thunderstorms may impact all terminals.
Long Term...VFR to MVFR expected Monday. A cold front will cross
the region with showers and thunderstorms on Tuesday resulting
in areas of IFR to LIFR in any thunderstorms. High pressure
will return VFR conditions on Wednesday through Thursday.
&&
.MARINE...
Short Term... Quiet conditions over the waters through the end
of the week. Fog will move in overnight as warmer more humid air
advects northwards. Late Monday will see increasing
southwesterly flow ahead of Tuesdays front which may approach
SCA on the outer waters.
Long Term...Winds and Waves heights may reach SCA conditions
Tuesday and Tuesday Night as a cold front approaches and
crosses the waters. High pressure will build in Wed through Fri
resulting in decreasing winds and waves.
&&
.TIDES/COASTAL FLOODING...
The area continues to be in a astronomically high tide these
next few nights. Tonight high tide at Portland is 11.8ft at
12:59am. The midday tide today was running a few tenths above
forecast which would put the overnight tide right at flood
level. With calm conditions leading to almost no wave action
have opted to just put out a statement for this high water
condition.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...None.
NH...None.
MARINE...None.
&&
$$
NEAR TERM...Hanes/Watson
SHORT TERM...Curtis
LONG TERM...Lulofs
AVIATION...Curtis/Lulofs
MARINE...Curtis/Lulofs
Area Forecast Discussion
National Weather Service Indianapolis IN
1147 PM EDT Sat Jul 14 2018
.UPDATE...
The AVIATION Section has been updated below.
&&
.SYNOPSIS...
Issued at 300 AM EDT Sat Jul 14 2018
A combination of upper disturbances along with a cold front will
bring chances for rain to the area later Saturday through Monday
night. High pressure will then keep the middle part of the week dry
before another system brings more rain chances to end the week. Hot
and humid conditions will persist into early next week, then near
normal temperatures will return.
&&
.NEAR TERM /Tonight/...
Issued at 908 PM EDT Sat Jul 14 2018
Mid level vorticity center currently over Illinois will be
drifting into the area later tonight, based on short term model
data. Large area of convection associated with this feature has
been weakening recently, with cloud tops warming. Air mass is not
particularly unstable for this time of year locally, and pattern
not very favorable for widespread nocturnal convection tonight
with light flow at 850mb. Will keep chance PoPs in the forecast
for the rest of night as the vorticity center moves into the area.
Previous discussion follows.
A weak boundary was found stretching from Southern Lake Michigan
across Northern Illinois to Northern Missouri late this morning.
High pressure was found across the Virginias...with weak southerly
flow in place across Indiana. Dew point temperatures across
Central Indiana were in the humid upper 60s and lower 70s.
Forecast soundings this afternoon continue to suggest a dry column
across Central Indiana. &00mb temps again appear warm enough to
provide a decent mid level cap as convective temperature remain
in the mid 90s. Models and HRRR suggest the weak boundary to the
northwest will remain there through the afternoon and that will be
the focus area for potential convection through the day. Thus
have trended toward a dry forecast this afternoon. With full
sunshine expected have trended highs slightly warmer than
persistence.
Better chances for precip will arrive tonight as the surface
boundary sags southward toward Central Indiana.
&&
.SHORT TERM...(Tonight through Monday night)
Issued at 300 AM EDT Sat Jul 14 2018
Models are close enough that the model blend initialization
was accepted for most items.
The weak upper trough will move into the area tonight and remain
around through the remainder of the short term. A cold front will
also move in as well. These will interact with moisture and
instability to produce chances for showers and thunderstorms
through the period.
With convection dependent on timing of various impulses in the
trough, do not feel confident enough to go higher than chance
category PoPs for any period. Put the highest PoPs in on Monday into
Monday evening as the front moves through.
Coverage of convection on Sunday should be low enough to allow
temperatures to peak around 90. Monday will be a little cooler with
more convection around.
&&
.LONG TERM /Tuesday Night THrough Saturday/...
Issued at 209 PM EDT Sat Jul 14 2018
ECMWF suggests quiet weather for the middle part of the work week
as NW flow and subsidence will be in place across the Great Lakes
and Indiana. The Ecmwf suggests a moderate upper wave to dig
south toward Indiana on Friday and Saturday within the NW flow
aloft. Good forcing and even associated lower level features
appear in play on Thursday Night through Saturday as the upper
wave passes. Forecast builder has included pops at that time and
this seems quite reasonable. A few more similar runs will result
in higher confidence for precip along with high pops. Stay Tuned.
&&
.AVIATION /Discussion for the 150600Z TAFS/...
Issued at 1145 PM EDT Sat Jul 14 2018
Mid level vorticity center currently drifting through Illinois
will begin moving into the western parts of Indiana after about
150700Z. Scattered convection is possible in the vicinity of the
terminals after that time, and this threat looks to continue past
sunrise Sunday with the vorticity center lingering over the area.
Otherwise, outside of any convective areas, ceilings above 050
expected through midday Sunday. Potential for some areas of
visibility restrictions in fog to develop overnight as dewpoint
depressions are quite low, but extensive mid level cloud and
potential convection suggests threat for widespread IFR
restrictions is low.
Light surface winds overnight will become 170-190 degrees at 5-8
kts by late morning Sunday.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...50
NEAR TERM...Puma/JAS
SHORT TERM...50
LONG TERM....Puma
AVIATION...JAS
Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
643 PM CDT Sat Jul 14 2018
.SHORT TERM...
153 PM CDT
Through Tonight...
With the extent of the rain and thunderstorm activity Saturday
morning, the environment across northeast Illinois and northwest
Indiana is rather stable, or at least more capped to convection.
SPC Convective allowing models which were suggesting more activity
this afternoon seem to be a bit overdone, with the HRRR
suggesting outside of some lighter rain north and some
thunderstorms far south, that we will be fairly quiet through mid
to late afternoon.
The more significant thunderstorm activity will now look to be
tied closer to the stronger forcing over Missouri which will
eventually spread toward central Illinois through the afternoon.
Have held onto the best chances for additional storm development
well south of I-80 late this afternoon and early evening tied to
this better forcing and some additional instability.
NW-SE moving shortwave energy aloft should prevent this activity
from making too far northward progress into the area tonight, but
have hung onto very low chances farther north if the energy is
shifted north. Some fog will develop tonight in the light wind,
moist environment.
KMD
&&
.LONG TERM...
315 PM CDT
Sunday through Saturday...
This stretch of uncomfortably humid conditions will come to an end
on Monday and with it the chances for periodic isolated to widely
scattered thunderstorms will also end on Monday for at least a few
days.
Forcing looks to be minimal at best on Sunday in the wake of the
short-wave dropping south across the region through tonight.
Another short-wave over eastern Kansas this afternoon should
generally track across central and downstate IL on Sunday. 925 mb
temps progged generally support upper 80s to lower 90s for highs,
however a lack of capping should enable a Cu field to form pretty
quickly, so anticipating primarily upper 80s away from the Lake
Michigan shore. Given very light wind field in non-existent
pressure gradient, a lake breeze should form and push inland into
northeast Illinois and northwest Indiana and keep temperatures
there upper 70s-lower 80s. Dewpoints into the mid 70s outside of
Chicago and locally upper 70s from evapotranspiration will yield
peak heat index values inland in 95-100 range, so certainly an
uncomfortable day.
Turning back to the overall lack of forcing tomorrow, it casts
doubt on convective coverage. While soundings indicate moderate to
strong uncapped instability, gut feeling is that best chance for
widely scattered t-storms will be primarily south of I-80 closer
to the glancing blow from S/W to south. Farther north, coverage if
any may end up being isolated at most, perhaps with lake breeze
convergence aiding in a few more storms popping near the boundary
as it pushes inland. Any thunderstorms that do form will be of the
slow moving pulse variety and likely fairly quick to decay given
very meager deep layer wind shear. PWATs will continue to be in
the 1.75" to 2" range, so brief heavy downpours would be expected
with storms before they decay and also can`t rule out brief gusty
winds from core collapses. Do not anticipate a severe risk given
aforementioned weak shear keeping updrafts shorter lived.
A cold front will approach on Sunday night into Monday, but loss
of diurnal instability and weak shear should result in any
thunderstorms quickly dissipating Sunday evening and maybe
isolated at the very most overnight. The frontal wind shift will
have a relatively unfavorable morning to early afternoon timing on
Monday, however a weak short-wave lagging the front could trigger
isolated to widely scattered thunderstorms (perhaps best chance
I-80 south) before drying and stabilization occurs later in the
day. Highs in the mid to upper 80s and dew points in the 70s
should support moderate instability, though deep layer shear will
again be weak and likely preclude much if any risk for
strong/marginally severe storms. Northwest winds behind wind
shift should flop over to onshore near the lake, with highs in the
low 80s lakeside behind the lake breeze. Secondary cold front with
stronger cool/dry push will arrive Monday evening-night.
Tuesday and at least Wednesday will be slightly below seasonable
upper 70s-lower 80s and noticeably less humid as high pressure
overspreads the area, with mid 70s near Lake Michigan due to
onshore flow. The main concern on Tuesday is brisk northerly winds
expected to build waves and result in dangerous swimming
conditions at Lake Michigan beaches. Thursday could be more of the
same as Tuesday-Wednesday though the uncertainty for the late
week period including Friday-Saturday is an approaching trough
from the west/northwest which could result in some shower and
thunderstorm risk over the region, though there`s plenty of
uncertainty in how things play out.
Castro
&&
.AVIATION...
For the 00Z TAFs...
643 pm...Forecast concerns include a chance of thunderstorms
tonight/Sunday afternoon...fog/low clouds Sunday morning and a
lake breeze Sunday afternoon.
Isolated thunderstorms continue to develop along the IL/IA border
and this activity may continue to slowly drift east into north
central IL this evening...possibly affecting rfd. Confidence is
low and there may be some new isolated development as far east as
arr/lot by mid/late evening. Additional activity across west/
central IL is expected to mainly move east and remain south of the
terminals. On Sunday...with weak forcing aloft...confidence for
thunderstorms is low. A lake breeze is expected and this may allow
isolated activity to develop.
Light east/southeast winds this evening will become light and
variable or calm overnight and then light southerly Sunday
morning. The weak gradient will allow a lake breeze to develop
Sunday afternoon and it is expected to move through ord/mdw with
medium confidence for timing.
The light winds and moist low levels after rain earlier today
should allow some light fog to develop overnight. Trends will
need to be monitored later tonight as its possible ifr/lifr vis
may develop away from the immediate Chicago metro area. Lower cigs
are also possible but confidence at ord/mdw remains low. cms
&&
.MARINE...
329 PM CDT
Fairly benign conditions expected on the lake will continue
through Sunday night or Monday with mainly light/variable winds
driven by land-sea breeze circulations. The exception will
obviously be with any storms creating locally and briefly higher
winds and waves. A few cold fronts will move down the lake Sunday
night into Monday, followed by a secondary front with a stronger
push of cooler air Monday night. Expecting a period of fairly
brisk northerly winds up to 20-25 kt, especially for southern
Lake Michigan on Tuesday. This will likely result in hazardous
conditions for small craft for the Illinois and Indiana nearshore
waters. High pressure will then build into the western Great
Lakes region on Wednesday with lighter northerly flow augmented
by lake-sea breeze circulations throug Thursday.
Izzi/Castro
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...None.
IN...None.
LM...None.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion...UPDATED
National Weather Service Twin Cities/Chanhassen MN
741 PM CDT Sat Jul 14 2018
.SHORT TERM...(This evening through Sunday)
Issued at 245 PM CDT Sat Jul 14 2018
Short term concern remains convective threat Sunday.
Few cumulus develop in moist lower levels this morning. This will
dissipate quickly late afternoon/evening. Some thicker moisture
remains to the southeast and models suggest some of this may work
slowly north overnight. Some threat of fog forming again to the
east with light winds remaining. It will be regulated by any lower
cloud intrusion later tonight from the southeast. The west will
see enough gradient ahead of the incoming cold front to preclude
fog formation.
Perusing ensembles and various CAMS indicates the potential of at
least some isolated convection the front moves east into Sunday.
The latest version of the HRRR is trying to develop at least a
weak complex across South Dakota late tonight and this may work
into west central MN early Sunday. Afternoon heating appears
significant enough to generate MLCAPE of around 1000 J/kg ahead
of the boundary and with the weak forcing from the upper trough,
may be enough to generate at least isolated convection along the
boundary with both the GFS and NAM deterministic models
generating some light QPF. Convergence remains quite weak along
the boundary however. Have included some small PoPs for this for
now.
.LONG TERM...(Sunday night through Saturday)
Issued at 245 PM CDT Sat Jul 14 2018
Long term trends continue to bring in much cooler/drier air over
the region early in the week. This should provide slightly below
normal temperatures and dewpoints back to the 50s.
Both the GFS and ECMWF are driving some trough energy across South
Dakota mid/late in the week. The ECMWF remains most amplified and
lower with its progression east. It moves a closed circulation
over the area mainly Thursday into Friday, with the GFS delivering
PoPs late Wednesday night through Thursday night. We will need to
monitor overall trends for this system. We could see some heavier
convection/rainfall if system becomes more organized and slow
moving.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 741 PM CDT Sat Jul 14 2018
VFR this evening, but some patchy fog may redevelop overnight. Not
expecting it to be as widespread as last night due to drier air in
place. Winds will remain light until the cold front pushes through
Sunday afternoon and northwest winds increase. Probability of
precip is too low to mention at any of the TAF sites through the
period.
KMSP...No concerns this evening. Maybe some light fog again late
tonight.
/OUTLOOK FOR KMSP/
MON...VFR. NW wind 10G20 kt.
TUE...VFR. NW Wind 5 kt.
WED...VFR. Slgt Chance MVFR with -TSRA late. SE Wind 5-10 kt.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
&&
$$
SHORT TERM...DWE
LONG TERM...
AVIATION...BORGHOFF
Area Forecast Discussion
National Weather Service Paducah KY
947 PM CDT Sat Jul 14 2018
.MESOSCALE DISCUSSION...
Issued at 946 PM CDT Sat Jul 14 2018
The general trend the past 30 minutes has been for warming tops
and decreasing reflectivity in the three mesoscale convective
systems in our area. The atmosphere finally appears to be
stabilizing due to the combined effects of noctural cooling and
outflow from earlier storms. However, a small area of se Missouri
around kpof is still maintaining mixed layer capes near 3000 j/kg
as analyzed on the spc mesoanalysis webpage.
It appears the primary hazard has become heavy rain as the 500 mb
shortwave over Missouri generates sufficient lift to maintain
convection. The high-res guidance indicates a decreasing trend
overnight, however there are exceptions such as the hrrr and the
18z nam. With precip water values near 2 inches and 850 mb flow
averaging 15 knots, the potential for heavy rain will continue
well into the night. The heavy rain threat will likely remain
mostly in the most unstable air over se Missouri, and also where
upper-level forcing is stronger in southern Illinois. Social
media, HWO, and forecast grids mention heavy rain in those areas.
&&
.SHORT TERM...(Tonight through Monday night)
Issued at 111 PM CDT Sat Jul 14 2018
Fairly good confidence in the short term.
Sticky situation this afternoon with heat index readings ranging
from 99 in the north and east with 105 to 111 elsewhere. Next we
have strong storms developing over southeast Missouri and southern
Illinois. These will demand a close watch into the evening hours
at the very least. We also have an air quality alert for southwest
Indiana. So a very active near term in progress. As previously
stated the storms will be a concern tonight as the MCV coming out
of Kansas continues to track east. This feature could enhance the
already strong storms as we head into the evening. Again the
MCV...combined high temperatures and abundant moisture cause more
storms farther east Sunday. Sunday we will have ML CAPES 2k-3k
j/kg. We will have 25-30 knots bulk shear. So the main threat
would be wind followed by heavy rain. Thunderstorm will remain
possible Monday as a cold front bears down on the region which
should exit Tuesday. Which should bring our best break from the
extended heat wave.
.LONG TERM...(Tuesday through Saturday)
Issued at 111 PM CDT Sat Jul 14 2018
High confidence continues in the overall pattern shown by the models
with medium confidence in the exact timing.
By Tuesday the front should be exiting southeast as the upper level
trough progresses toward the east coast. This will allow high
pressure to build into the region for the middle of the week. This
will be our first good chance at some relief from the heat and
humidity. The temperatures will only fall into the middle and upper
80s for the rest of the week but dew points will fall into the
middle to upper 60s. The combination of this will yield a
considerably more comfortable heat index. Ridging over the west will
slowly push eastward causing the next trough to sharpen as it moves
through our region. This will be accompanied by another system at
the surface coming out of the southern plains. As these system will
work in tandem to bring our next chance of storms to the region late
in the week. Right now the late week system does not look that
strong so will keep the pops no more than chance for this issuance.
Winds will start out of the north Tuesday and slowly start to take
on a little more easterly component toward the end of the week.
&&
.AVIATION...
Issued at 618 PM CDT Sat Jul 14 2018
Scattered thunderstorms will gradually decrease tonight. None
appear to be an immediate threat to the taf sites as of 23z,
although some weakening storms near kevv/kowb could produce gusty
winds through 01z.
Some mvfr vsbys in fog are possible where rain falls this evening.
The best chance of fog will be around sunrise. As of 23z most of
the taf sites look rain free.
Sunday will be similar to today, with isolated to scattered storms
increasing as solar heating destabilizes the atmosphere.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...None.
MO...None.
IN...None.
KY...None.
&&
$$
MESOSCALE...MY
SHORT TERM...KH
LONG TERM...KH
AVIATION...MY
Area Forecast Discussion
National Weather Service Mount Holly NJ
928 PM EDT Sat Jul 14 2018
.SYNOPSIS...
High pressure across the Middle Atlantic region this evening will
weaken overnight. An upper air trough will cross the area Sunday,
followed by another later Monday. Low pressure and a cold front will
cross our region Tuesday and Tuesday night. High pressure will build
in for the middle of the week and remain through Friday. Another
disturbance will arrive for next weekend.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
A 00z mesoanalysis placed the eastern edge of the axis of MLCAPE
from far northwestern New Jersey and the Poconos west and
southwestward. Noticed that the HRRR and the NAMnest have nearly
lost the convection now overnight (HRRR develops some convection in
eastern Pennsylvania after 12z Sunday), and this may be due to the
ongoing convection just to our northwest using up most of the
current instability. In addition, the forcing with the remnant
convectively induced short wave looks to waning with time and
therefore the current convection approaching the Poconos may end up
dissipating as it tracks east-southeastward through about midnight.
There is still a short wave trough approaching overnight, and with a
plume of higher precipitable water and some lingering instability,
some showers and a few thunderstorms cannot be ruled out. This looks
to be still placed across mainly northeastern Pennsylvania to
northern New Jersey. Given the uncertainty, initially trimmed back
the PoPs but kept the idea of some isolated to scattered
showers/thunder overnight and especially toward daybreak. Made some
tweaks to the hourly temperature, dew point and wind grids based on
the latest observations and trends. There is a pocket of lower dew
points in and around the Philadelphia metro, however these should
increase some though overnight.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
For Sunday, there should be some showers and thunderstorms
continuing after sunrise over parts of northern or central NJ to
perhaps into eastern Pennsylvania. There could be a lull or main
activity moving offshore around midday, but then increasing heat and
humidity and resultant CAPE will likely lead to more afternoon
convection, especially N/W of PHL. Max temps are forecast similar to
today, but the sfc dewpoints will rise into the mid-upper-60s,
resulting in more uncomfortable conditions.
&&
.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
Sunday night...A few lingering showers and tstms are possible during
the evening, but then fair weather expected overnight. A warm and
humid overnight with lows only in the low 70s most areas.
Monday/Monday night...Unsettled with scattered tstms as an upper
level trough crosses the area and plenty of very warm and humid air
remains at the sfc. The greatest chc for tstms (mostly high chc /
low likely) will be over the srn Poconos and NW NJ.
Tuesday/Tuesday night...Showers and tstms will be widespread on
Tuesday as the humid airmass yields to a cold front crossing the
region. The front is rather potent for July, so heavy rains and
strong tstms are possible. We`ll wait until tomorrow to see the SPC
outlook for Day3, but profiles seem to indicate that some svr is
possible for that day, especially N/W. We will continue to keep the
mention of heavy rains in the grids and in the HWO too. More high
temperatures in the upper 80s/ low 90s for Tuesday and humid also.
This will be the final day of the heat and humidity. Heat indicies
may approach 100 in the I-95 urban corridor and Delmarva.
Wednesday thru Friday...The cold front will be east of the region
Wednesday. This period will be mostly dry with high pressure
building in. Highs will be seasonable with low/mid 80s in most
areas, but the overnight lows will be cool for July with 50s across
the north/west and low/mid 60s for Delmarva and srn NJ. These lows
will be around 5 degrees below normal. The airmass will be dry as
well, a good contrast from the airmass early next week.
Next weekend...Most of the operational models have a trough digging
in the east again late next week. Moisture is expected to move N/NE
across the Middle Atlantic, so probably some showers/tstms will
occur at these times. We`ll just have some chc pops for those
periods attm. Temperatures mostly near normal with an uptick in the
humidity again. This time of the year is the warmest part
climatologically.
&&
.AVIATION /02Z SUNDAY THROUGH THURSDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas.
Rest of tonight...Mainly VFR. Some showers and thunderstorms may be
near mostly ABE to TTN overnight. Southwest winds 5-10 knots,
diminishing to less than 5 knots or locally light and variable. The
timing and southern extent of any showers and thunderstorms is of
low confidence.
Sunday...Mainly VFR. Some showers and thunderstorms should be around
in the morning especially from ABE to PNE northward, then a few
showers and thunderstorms in the afternoon. Southwest winds increase
to around 10 knots. Timing and extent of showers and thunderstorms
is of lower confidence.
Outlook...
Sunday night...Mostly VFR. A few evening showers/tstms psbl.
Monday and Monday night...Mostly VFR. Sct tstms N/W with lower
conditions psbl.
Tuesday and Tuesday night...MVFR/IFR at times in occasional
showers and tstms.
Wednesday and Thursday...VFR expected.
&&
.MARINE...
The conditions are expected to remain below Small Craft Advisory
criteria through Sunday. Southerly winds though will gust up to 20
knots at times. Some showers and thunderstorms are possible late
tonight and early Sunday morning mainly north of Little Egg Inlet,
NJ.
Outlook...
Sunday night and Monday...Sub-SCA. Sct tstms Monday.
Monday night through Tuesday night...SCA psbl. Showers/tstms
expected.
Wednesday through Thursday...Sub-SCA.
Rip Currents...
For Sunday, a moderate risk of rip currents has been issued for
both the New Jersey and Delaware beaches. A south to southwest
wind is expected once again and it appears that while the swells
may decrease some there may continue to be underlying 12 second
long period swell energy. This would tend to result in rougher
conditions especially late morning and afternoon as the winds
increase.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...None.
NJ...None.
DE...None.
MD...None.
MARINE...None.
&&
$$
Synopsis...O`Hara
Near Term...Gorse
Short Term...AMC
Long Term...O`Hara
Aviation...Gorse/O`Hara
Marine...AMC/Gorse/O`Hara
Area Forecast Discussion
National Weather Service Phoenix AZ
856 PM MST Sat Jul 14 2018
.SYNOPSIS...
Moisture levels will remain high enough through at least early
next week to produce isolated to scattered showers and
thunderstorms across most of the region. Storm chances will expand
in coverage into early next week with both morning and afternoon
rainfall possible. Temperatures will be highly variable depending
on cloud cover or lack there of, though the increased moisture
will make it feel unusually muggy regardless.
&&
.DISCUSSION...
Abundant moisture remains situated across the majority of Arizona
with a PWATS of 1.7-1.9" stretching from south-central Arizona
northwestward toward Las Vegas. PWATs drop off to the east and to
the west, but remain sufficient for monsoon activity across all
but southwest Arizona and southeast California. An area of
showers and embedded thunderstorms in still ongoing as of 9 PM
across east-central Arizona, similar to last night at this time.
An MCV from this area of diminishing storms is already evident
and is picked up by the HRRR which brings it into the south-
central Arizona deserts later tonight. CAPES will remain marginal
overnight, so we could see a few showers associated with the MCV,
but we do not anticipate any organized thunderstorm activity. For
Sunday, afternoon and evening storms are again likely, but
coverage should be similar to what we had today as there is no
clear trigger and considerable cloudiness should again limit
daytime heating in many areas.
&&
.PREVIOUS DISCUSSION...
Model guidance, including the latest GFS and ECMWF, have been
advertising an inverted trof to move westward out of New Mexico
and into Arizona over the weekend and into the early part of next
week but the guidance has had trouble resolving the details of
this inverted trof feature. Over the past couple of days, the trof
has trended weaker and more amorphous, less pronounced and slower
to move west. Latest runs, including GEFS ensemble runs, continue
this trend and actually take the bulk of the trof south of
Arizona and through NW Mexico and into the gulf of CA by the
middle of next week. We do expect that as this feature slowly
moves into the area this weekend and westward during the first
part of next week, moisture will increase along with thunderstorms
chances. We still favor that trend, but at the moment it appears
hard to say which day from Sunday through next Tuesday will be the
most active. Many model parameters, including PWAT, CAPE, 850mb
dewpoints and lifted indices really don`t change much day to day,
and wind fields aloft do trend weaker although steering flow is
from the northeast to east (favorable for storms moving into the
deserts). Over the next several days, guidance keeps conditions
over the deserts somewhat on the stable side despite moisture
increasing, with lifted indices positive over much of the area
west of Phoenix. Due to confidence being low in determining which
day might be the most active, we will go with a rather broad brush
forecast, keeping slight chance POPs over lower deserts and
keeping chance numbers over the higher terrain east of Phoenix. In
other words, a low to moderate grade monsoon forecast. High temps
each day will not change much but will tend to stay a bit below
seasonal normals each day.
For the latter portion of the forecast, Wednesday into Friday,
guidance continues to call for high pressure building over the
western CONUS, with the high center shifting east and into the
vicinity of the four corners. 500mb heights climb with time,
exceeding 598dm at the center by Friday, and as the ridge builds the
atmosphere dries out a bit. Steering flow becomes more
southeasterly, not a bad direction for getting storms into the
central deserts, but overall we will be expecting lower grade
monsoon conditions with high temps climbing above seasonal normals.
Expect hotter deserts to climb each day, reaching to around 110 by
next Friday.
&&
.AVIATION...
South-Central Arizona including KPHX, KIWA, and KSDL:
Winds have for the most part already switched out of the east and
will remain fairly light out of the east through Sunday morning.
We can`t rule out the possibility of showers during the overnight
period, but at this point confidence is too low to include in
TAFs. Very moist conditions should again lead to high terrain
storms Sunday afternoon and evening, but as with the past couple
days storms will be more limited across the lower deserts.
Southeast California/Southwest Arizona including KIPL and KBLH:
There are no aviation weather concerns as winds will follow
typical diurnal trends and remain relatively light. Otherwise,
skies will be mostly clear.
&&
.FIRE WEATHER...
Tuesday through Saturday:
Monsoon moisture will remain in place with scattered to isolated
showers and thunderstorms anticipated through the middle
part of the week. This will include pockets of wetting rains,
especially over the higher terrain of eastern areas. A slow drying
and warming trend will develop during the latter half of the week,
except for the higher terrain locales where isolated storms will
continue. Min RH values will remain above 20 percent across the
region except for SE CA where it will range near 15-20 percent.
Outside of gusty thunderstorm winds, expect typical light to
moderate winds favoring variable, diurnal and afternoon upslope
patterns. Overnight recovery will generally be fair to good and
occasionally excellent.
&&
.SPOTTER INFORMATION STATEMENT...
Spotters should follow standard reporting procedures through this
active period into next week.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...None.
CA...None.
&&
$$
DISCUSSION...Kuhlman
PREVIOUS DISCUSSION..CB
AVIATION...Kuhlman
FIRE WEATHER...Hirsch/Sawtelle
Area Forecast Discussion
National Weather Service Blacksburg VA
754 PM EDT Sat Jul 14 2018
.SYNOPSIS...
High pressure over the region will slide east tonight into
Sunday. Increasing heat and humidity is expected to return
along with better chances of showers and thunderstorms ahead of
the next cold front for early next week. High pressure
will build over the area Midweek as a cold front sink further
south into the Carolinas.
&&
.NEAR TERM /THROUGH SUNDAY/...
As of 743 PM EDT Saturday...Overall no particularly significant
changes were needed to the going forecast. Ridge of high
pressure still prevails providing for a mild and increasingly
humid late afternoon across the region. A few isolated showers
will remain possible in the mountains of northwest NC and into
Grayson County through sunset before dissipating. Unlike prior
nights, should see less banked stratus as synoptic gradient flow
and surface winds turn more south to southwest late tonight and
into overnight. Flow should be light enough to permit some
river valley fog but coverage should be limited, especially with
expectation of at least mid to high clouds increasing from west
to east toward early morning. Appears that these clouds stem
from convective blowoff from ongoing storms in western Ohio
Valley/TN Valley. Greatest cloud cover by morning should be
across the western third of the CWA, but this should mainly be
mid to high clouds. Should stay clear in the VA/NC Piedmont,
however. No changes to lows which should be again mainly in the
60s.
Looking ahead, worth noting that some higher-resolution
guidance such as the 18z NAM-3km and to an extent the HRRR
breaks at least showers or perhaps thunder by mid-morning as far
east as the Blue Ridge - a bit earlier than presently indicated.
Will keep in mind for possible changes as we look toward the
00z forecast guidance.
Previous discussion follows...
1022 MB Surface High centered over eastern Virginia will gradually
drift east tonight into Sunday. As the surface high shifts east and
offshore, upper level ridging to the west punches east. The flow
aloft turns more southwesterly with time resulting in an increase in
850 mb warming.
The HiresW-ARW-East,HRRR,NAM,GFS and ECMWF showed isolated to widely
scattered showers and thunderstorms possible in the west this
afternoon into this evening. The best chance for convection is in
the southwest mountains.
Any isolated convection this afternoon will diminish quickly with
the loss of solar heating this evening into tonight. Overnight into
Sunday morning, patchy fog will develop mainly in the western
valleys because of the light winds and low level moisture. Low
temperatures tonight will generally range from the lower 60s in the
west to the upper 60s in the east.
The upper ridge will start to flatten on Sunday. With a more
southerly flow on Sunday, PW values and associated instability
increase into Sunday afternoon, especially along and west of the
Blue Ridge. An upper level shortwave approaches from the northwest
late in the afternoon. As a result, scattered showers and
thunderstorms will develop in the west. With morning stratus and fog
in the mountains quickly eroding and 850mb winds veer to the
southwest providing some downsloping, high temperatures Sunday will
warm into the upper 70s in the mountains to the lower 90s in
the Piedmont.
Confidence is high during the forecast near term period.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/...
As of 307 PM EDT Saturday...
Sunday`s afternoon storms will fade through the evening, however
scattered showers may persist into the early morning hours as weak
short waves track in a moisture rich environment. Southwest flow
Monday will transport more moisture into the region pushing PWAT
values to 150 percent above normal. The combination of outflow
boundaries, differiental heating and weak convergence should produce
more areal coverage of storms across the mountains and foothills in
the afternoon. A few of the storms Monday may produce locally heavy
rain with forecast soundings showing long skinny CAPE profiles
indicating a deep warm cloud layer. We also can not rule out an
isolated strong to severe storm producing damaging winds as an upper
level trough across the Ohio and Tennessee Valleys sends weak short
waves over the area. This upper level trough will move over the
southern Appalachians Monday night, keep convection going for most of
the night.
As this upper level trough drifts east Tuesday, surface to low level
winds will veer to the west. In the afternoon, a cold front will
track from the Ohio and Tennesse Valleys, then over the Appalachians
Mountains. With a west wind out ahead of the front, the chances for
severe storms will be somewhat limited across the mountains, but the
chance for heavy downpours and localize flooding is elevated. It is
a different story in the east as afternoon heating increases
instabilities, therefore boosts the potential for storms to become
strong to severe going into the evening. The primary threat will be
damaging straight-line winds. Yesterday`s models had the front
stalling over Southside VA into Wednesday morning. Today`s models
has the front clearing the forecast area in the evening and moving
south into the Carolinas overnight.
Afternoon temperatures Monday and Tuesday will run at or slightly
above normal with upper 70s to mid 80s west of the Blue Ridge to
upper 80s to lower 90s east. Overnight temperatures will remain
muggy in the 60s to lower 70s.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
As of 307 PM EDT Saturday...
High pressure will build over the region on Wednesday as a cold
front sink further south into the Carolinas. This high pressure
system should keep the forecast area dry through at least Thursday
night. Wednesday and Thursday`s high temperatures will be a few
degrees cooler than normal.
On Friday, models are tracking a Gulf disturbance moving along a
stalled frontal boundary across the Carolinas. The GFS has this
disturbance tracking northeast across the Carolinas and moving off
the North Carolina coast Saturday night. This will keep most of the
area dry with light rain showers moving east along the VA/NC border
Friday night into Saturday morning. The ECM has this tropical
disturbance tracking northward Friday into Saturday. This track may
bring 1-3 inches of rain to the piedmont and around a half to one
inch to areas along and west of the Blue Ridge. The main difference
between models is the upper level pattern. The GFS has an open
trough sitting over the Ohio-Tennessee Valley. The ECM has a closed
low over the Great Lakes. For now, we will keep PoPs low, which is
in-line with our confidence.
Temperatures Friday and Saturday could be around normal if the drier
GFS is correct. If the wet ECM verifies, temperatures may only warm
into the 70s.
&&
.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
As of 754 PM EDT Saturday...
VFR conditions through about midnight with any leftover isolated
showers in the southern Blue Ridge/NW NC mountains fizzling with
sunset. Should see some development of MVFR-IFR mist in the
western river valleys (e.g. Lewisburg and Blacksburg TAFs)
starting around 09z. Duration and coverage may prove limited
with winds becoming more south-southwest and cloud cover on the
increase late. Light south winds should become light/calm
overnight, then tend south/southwest toward early morning.
Into Sunday, likely to see multi-layered VFR deck progressing
eastward with Cu underneath a mid/high level deck as disturbance
aloft topples upper level ridge. This disturbance should spark
scattered showers and thunderstorms; while the best chance of
storms is in the afternoon, confidence on start time is low as
recent guidance has trended a bit faster - showing storms
potentially as early as mid-/late-morning from Bluefield to
Blacksburg. Will indicate VCSH for terminals along/west of the
Blue Ridge in the afternoon, but change may be needed if it
becomes more clear that showers/storms may begin sooner. It may
take until late in the TAF period for thunder to reach Lynchburg
and Danville. Any thunderstorm capable of lightning, gusty
outflow/localized turbulence and IFR or lower visbys in heavy
rain. Outside of thunderstorms, winds should tend south-
southwest 3-6 kts.
Confidence is moderate to high on aviation elements, though is
low on thunderstorm timing.
Extended Aviation...
Showers and storms should become more widespread especially
mountains by Monday afternoon and across the region on Tuesday
ahead of an approaching cold front. However confidence is too
low to pinpoint where the showers and thunderstorms may occur.
Also likely to see late night/early morning patchy fog result in
localized sub-VFR in the valleys and where any earlier rainfall
occurred each day through Tuesday. Conditions will dry out
Wednesday, then moisture will return from the south Thursday.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...None.
NC...None.
WV...None.
&&
$$
SYNOPSIS...KK/PM
NEAR TERM...AL/KK
SHORT TERM...RCS
LONG TERM...RCS
AVIATION...AL/KK
Area Forecast Discussion
National Weather Service Tulsa OK
811 PM CDT Sat Jul 14 2018
.DISCUSSION...
Showers and thunderstorms have moved out of the forecast area this
evening. The latest HRRR suggests scattered convection may re-
develop overnight across parts of northeast Oklahoma and far
northwest Arkansas, so will leave pops as they are for later
tonight. Have lowered pops some though prior to 06Z. Made a few
minor changes to overnight lows based on current trends, with the
rest of the forecast looking good at this time.
Update on the way.
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...Heat Advisory from noon to 8 PM CDT Sunday for OKZ049-053-
060>062-064>067-070>073.
AR...Heat Advisory from noon to 8 PM CDT Sunday for ARZ019-020-029.
&&
$$
SHORT TERM...69
LONG TERM....05
PLATE