Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 07/29/18
Area Forecast Discussion
National Weather Service Albany NY
1011 PM EDT Sat Jul 28 2018
.SYNOPSIS...
High pressure will build in from the Ohio Valley
overnight into tomorrow with fair and dry weather to close the
weekend. The surface high will move over the region on Monday with
seasonable temperatures, but then an unsettled pattern with
scattered showers and thunderstorms is expected to return on Tuesday
and last most of the work week.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
As of 1011 PM EDT...A sfc trough of low pressure continues to
move east of New England, as the associated cold front is moving
east of the area. An isolated shower or thunderstorm will
dissipate over the next hour or so across the Schoharie
Valley/Capital Region with the upper trough axis moving towards
and across the forecast area between 03Z-09Z. High pressure will
ridge in from the Ohio Valley and the Great Lakes Region
thereafter.
The 3-km NAM and HRRR are similar with this trend with pretty
much all the isolated showers with perhaps a rumble of thunder
gone by midnight. Low to mid level cold advection occurs in
the wake of the sfc trough and its associated upper level trough
with H850 temps falling to +9C to +11C from the Capital Region
north and west, and +11C to +14C south and east. Lows will be in
the mid to upper 50s over the higher terrain, and upper 50s to
lower 60s in the valleys. Some patchy fog is likely to form
especially along and near the major valleys areas, and where
some the rainfall occurred this afternoon.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY NIGHT/...
Tomorrow...Fair and dry weather returns with high pressure
building in from the Ohio Valley into the Northeast. Morning
patchy fog and stratus will burn off with partly to mostly
sunny conditions. Humidity levels will lower and dewpts will
fall into the 50s to around 60F. Temps will be seasonable with
highs in the mid 70s to lower 80s with some upper 60s to lower
70s over the higher terrain.
Sunday night...The sfc high will build in over NY and New
England with fair and dry weather continuing with lows in the
50s. Some patchy radiational shallow mist/fog will form near the
major river valleys.
Mon-Mon night...Most of the day should stay dry with the sfc
high overhead initially then drifting offshore. Heights begin
to fall upstream ahead of an upper level trough over the Plains
and MS River Valley. A few warm advection showers may reach
locations west of the Hudson River Valley late in the day, but
the low and mid levels remain very dry on most of the guidance.
Highs will be a few degrees warmer than Sunday with lower to
mid 80s in the valleys areas, and 70s over the higher terrain.
Southwest flow sets up aloft over upstate NY Monday night with
a warm front trying to push through. The better synoptic lift is
west of the forecast area, but there is chance of some warm
advection showers towards or after midnight. A little bit of
elevated instability may poke into the Catskills or locations
west Albany for a slight chance of thunderstorms. Humidity
levels will be creeping up with lows in the upper 50s to mid
60s.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
This will be a typical pattern of mid-summer doldrums, with mild
temperatures, high humidities, and probable afternoon showers and
thunderstorms each day. Any frontal passages will be weak, with
the only hope for a break coming in the form of a Bermuda high
pressure system late next weekend.
High temperatures each day will range from the mid 70s to upper 80s,
with lows in the 60s to lower 70s. Normal highs in Albany are in
the lower 80s, with the normal lows in the lower 60s.
&&
.AVIATION /02Z SUNDAY THROUGH THURSDAY/...
A cold front will move east of the region with high pressure
building in from the Ohio Valley overnight into tomorrow.
The skies are clear to partly cloudy as a sfc trough moved east
of the region. Thunderstorms impacted KPOU/KALB earlier, and
isolated showers and thunderstorms are near KPSF. The recent wet
ground and light to calm winds will allow some mist/fog and
stratus to form tonight.
The best chance of for IFR/LIFR mist/fog will be at KPOU/KPSF.
We did include some MVFR/IFR mist and stratus at KALB similar to
this morning, but if the winds increase with the weak cold air
advection, then conditons may stay MVFR/VFR. KGFL may decouple
for some IFR/LIFR radiative mist/fog between 07Z-12Z. Conditions
should improve to VFR after 12Z, except at KALB/KPSF where some
MVFR stratus may linger until the late morning.
Expect VFR conditions for the afternoon with scattered cumulus
and sct-bkn cirrus. The skycover may become broken in terms of
the cumulus near KPSF in the afternoon.
The winds will be light to calm tonight, and increase from the
west to northwest at 5-10 kts in the late morning through the
afternoon, except at KGFL where the winds may be south/southwest
at 4-8 kts.
Outlook...
Sunday Night: No Operational Impact. NO SIG WX.
Monday: NO SIG WX.
Monday Night: Moderate Operational Impact. Chance of SHRA.
Tuesday: Moderate Operational Impact. Chance of SHRA...TSRA.
Tuesday Night: Moderate Operational Impact. Chance of SHRA.
Wednesday: Moderate Operational Impact. Chance of SHRA...TSRA.
Wednesday Night: Moderate Operational Impact. Chance of SHRA.
Thursday: Moderate Operational Impact. Chance of SHRA...TSRA.
&&
.FIRE WEATHER...
High pressure will build into the region tonight with the
isolated to scattered showers and thunderstorms ending. The
surface high will be over the region into Monday.
Minimal to no fire weather concerns are expected given recent
wet pattern over the past several days.
The RH values will increase to 90 to 100 percent Sunday morning,
and lower to 40 to 60 percent tomorrow. An excellent recovery
close to 100 percent is expected Monday morning.
The winds will shift to the west to northwest tonight at 5 to 10
mph tonight, and continue at 5 to 15 mph tomorrow before
becoming light to calm Sunday night.
&&
.HYDROLOGY...
Additional isolated to scattered showers and thunderstorms are
expected into early this evening. The lack of coverage of
storms will limit the flooding threat, although ponding in urban
and poor drainage areas are possible through this evening.
Mainly dry weather returns for Sunday and Monday before another
wet pattern sets up for Tuesday into Friday. Some very heavy
rainfall impacting small streams, and poor drainage areas may
arise again during this time frame, but overall main stem river
flows should lower.
For details on specific area rivers and lakes, including
observed and forecast river stages and lake elevations, please
visit the Advanced Hydrologic Prediction Service /AHPS/ graphs
on our website.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
MA...None.
VT...None.
&&
$$
SYNOPSIS...Wasula
NEAR TERM...Wasula
SHORT TERM...Wasula
LONG TERM...ELH
AVIATION...Wasula
FIRE WEATHER...Wasula
HYDROLOGY...BGM/Thompson/Wasula
Area Forecast Discussion
National Weather Service Boston/Norton MA
1116 PM EDT Sat Jul 28 2018
.SYNOPSIS...
Another round of showers and thunderstorms is occurring this
evening ahead of a sweeping cold front. Behind the front,
expect seasonably warm temperatures and lower humidity Sunday
and Monday. The summer heat and higher humidity returns midweek
as Bermuda high pressure sets up along the eastern seaboard.
A cold front will attempt to move through next weekend.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
Convection has really diminished over the past hour. Only
expecting isolated to scattered showers through about 2 AM, at
that point any showers should be well offshore.
Minor tweaks to the forecast this evening to reflect observed
trends, especially with rainfall chances. More tweaks will be
made if needed.
Previous Discussion...
*/ Highlights...
- Isolated t`storms N/W lifting NE overnight, diminishing
- Widespread rain lifting out to sea SE, yet fog lingers,
expanding into the SE coast overnight
- Cold front sweeping through towards early morning Sunday
behind which dry, refreshing air follows, conditions improve
*/ Mesoanalysis...
Not much change from earlier analysis. Tongue of < 0 Showalters
evident over SE areas of S New England, a wedge between sub-
tropical energy sweeping the Cape and Islands and the N-stream
vortmax and trailing cold front over N New England. Suppressed
environment in-between of sinking air is the likely culprit for
lack of shower and thunderstorm activity progressing into the
Boston - Providence corridor. As evident with earlier SE outflow
boundary from heavy rains over the Cape and Islands, even the
roughly 20-25 mph outflow into a fairly unstable airmass kicked
up showers, however only briefly as they quickly dissipated under
the weight of sinking and drier air aloft.
Activity N/W likely not to sulk S/E given the morphology of height
falls and cyclonic flow, the attendant N-stream vortmax and H3
jet streak curving NE into N ME. The trailing cold front sulking
S/E, however losing its better forcing with the vortmax stretching
away, the cold front becoming diffuse in the process. A refreshing
airmass behind it to follow into early morning Sunday which will
erode the low cloud / fog conditions impacting the SE shoreline.
More on that below.
Main threats with any thunderstorm activity of gusty winds, heavy
rain, frequent lightning.
PoPs reflective of latest HRRR trends tied into more broadscale
guidance of SREF / HREF / NBM. Focus over extreme SE New England
while encompassing much of the CT River Valley and Worcester Hills
with chance PoPs through 3z roughly.
Tonight...
Any showers and thunderstorms dissipating as N-stream vortmax
and attendant H5 trof axis lift N/E. Surface reflective cold
front pushing S/E however becoming diffuse against the offshore
lingering sub-tropical axis. This along with conclusion of day-
time heating, should see activity conclude.
Dense fog expanding over SE New England from the S-waters until
the W wind shift associated with the cold front. Refreshing air
in tow. Dry air advection proceeding, however given light winds
and clearing conditions, can`t rule out radiational cooling over
N/W MA given that they`ve seen around 1-2" with some locally
higher amounts over the last 72-hours. Very wet could hold in
shallow higher dewpoint air resulting, with radiational cooling,
in shallow dense ground fog in and around the Mid-CT River Valley.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...
Sunday...
Refreshing Summer day. Cold front pushing offshore becoming
diffuse however kicking any S-coastal dense fog out to sea with
winds shifting W. Light over all as weak high pressure settles
in, anticipating a near-shore sea-breeze allowance, however W
flow may be strong enough to limit interior progression. Energy
continuing to cyclonically rotate through the region, yet the
column considerably dry noted by very low K-indices. Anticipate
scattered to broken 4-5 kft cumulus. Mix down of a bit breezy W
winds, again to hold back sea-breezes, along with drier air.
Highs up around the upper 70s to low 80s with dewpoints in the
50s.
Sunday night...
Cool, dry night. Light winds, clear conditions, radiational
cooling. Watching the crossover threshold with respect to dew-
points observed at max-heating of the day, leaning shallow
ground fog formation in areas with observed higher dewpoints.
Looking at typically prone locations for seeing locally dense,
shallow ground fog. Leaned with lowest MOS forecast guidance.
Lows around the upper 50s to low 60s.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
Highlights...
* Warm front moves through Tuesday night
* Summer heat and humidity returns Wednesday through Friday
with scattered afternoon/evening thunderstorms
* Cold front attempts to move through next Saturday
Overview...
Persistent southwest flow aloft through next week with an
amplifying upper trough from the Great Lakes to the Gulf coast
and a building upper level ridge over the western Atlantic.
Daily details...
Monday...
Dry and warm with high pressure overhead. Light west-southwest
flow, with daytime sea breezes expected. Highs in the 80s with
dewpoints in the comfortable upper 50s and lower 60s.
Tuesday...
Warmer and slightly more humid air moves in on light southerly
flow between high pressure over the western Atlantic and low
pressure in the Midwest. Highs will reach the mid to upper 80s
away from the coast and dewpoints will rise to the mid 60s.
A warm front will approach from the south late in the day and
there is a slight chance of a shower or isolated thunderstorm
late.
Tuesday night...
A warm front moves through the region. There is a good chance of
showers and thunderstorms overnight, especially in western MA
and northern CT. Areas of fog are likely as dewpoint
temperatures rise to near 70 by daybreak.
Wednesday and Thursday...
Very warm and sultry with daytime highs in the upper 80s to
lower 90s over the interior and nighttime lows mainly in the
lower 70s. Dewpoints will be mainly in the lower 70s.
Heat Index values by Thursday will be nearing the two-
consecutive-day Heat Advisory Criteria of 95 degrees. Rather
breezy late Wednesday, as mixing leads to gusts to 20-25 mph.
There will be scattered thunderstorms, mainly in the afternoon
and evening hours. The chances are somewhat greater in western
sections on Wednesday afternoon/evening because upper level
southwest flow increases to 50-60 knots at 500 mb. Cannot rule
out isolated severe wind gusts reaching the ground in any
stronger storms. Precipitable water values will be near or above
2 inches, so also can expect torrential downpours and local
ponding of water from any thunderstorms.
Friday...
Still warm and humid with a chance of afternoon and evening
showers/thunderstorms. With the Bermuda high edging westward,
the best chances of precipitation will be in western portions
of southern New England.
Saturday...
A cold front will attempt to move slowly across the region.
This could lead to more widespread shower and thunderstorm
activity, along with locally heavy downpours. Cloud cover could
keep highs mainly from 80 to 85.
&&
.AVIATION /03Z 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/...Moderate confidence through
tonight. High confidence Sunday and Sunday night.
03z update (no major changes from 00z update)...
Tonight... SHRA moving offshore by about 05Z. Mostly VFR as
winds shift W, however, IFR-LIFR CIGs and VSBYs with dense FG
likely to expand or hold across SE New England until the W wind
shift towards Sunday morning. Also, patchy ground FG may develop
over CT River Valley terminals given light winds and clearing
towards Sunday morning.
Sunday...
BR / FG clearing out over SE-coastal New England early morning.
W winds allowing near shore sea-breezes beginning around 15z.
Otherwise SCT-BKN CIGs 4-5 kft agl. VFR.
Sunday night...
VFR. Light winds. Locally dense IFR-LIFR at typically prone
terminals.
KBOS Terminal...
Going to hold the terminal VFR and dry. SE wind shift has already
moved through and will roughly hold for the next couple of hours
will winds turn more SW ahead of a cold front expected to sweep
the terminal shortly after midnight with winds shifting W.
KBDL Terminal...
Hold VFR throughout. S/SW winds generally around 10 kts, winds
shifting W closer to midnight with cold frontal passage.
Outlook /Monday through Thursday/...
Monday: VFR.
Monday Night: Mainly VFR, with local IFR possible.
Tuesday: Mainly VFR, with local MVFR possible. Slight chance
SHRA, isolated TSRA.
Tuesday Night: Mainly VFR, with areas IFR possible. Chance
SHRA, chance TSRA, patchy BR.
Wednesday: Mainly VFR, with areas MVFR possible. Breezy. Chance
SHRA, chance TSRA.
Wednesday Night: Mainly VFR, with local IFR possible. Breezy.
Slight chance SHRA, slight chance TSRA, patchy BR.
Thursday: Mainly VFR, with areas MVFR possible. Breezy. Chance
SHRA, chance TSRA.
&&
.MARINE...
Forecaster Confidence Levels...
Low - less than 30 percent.
Moderate - 30 to 60 percent.
High - greater than 60 percent.
Short Term /through Sunday Night/...
7 pm update (no major changes from 5 pm update)...
SE wind shift has progressed up the waters behind which sustained
winds have been generally 10-15 kts with gusts up to 20 kts.
Expect SE winds to continue through this evening, shifting SW
and remaining breezy ahead of a sweeping cold front with passage
closer to morning. Winds shifting W with passage, there could
be a brief period of breezy winds again with gusts up to 20 kts.
Wind activity diminishing into Sunday with a weak area of high
pressure building in. Winds light enough to allow for near-shore
sea-breezes. Good boating weather lasting through Sunday night.
Outlook /Monday through Thursday/...
Monday: Winds less than 25 kt.
Monday Night: Winds less than 25 kt. Patchy fog. Local
visibility 1 to 3 nm.
Tuesday through Tuesday Night: Winds less than 25 kt.
Wednesday: Winds less than 25 kt. Areas of seas approaching
5 ft. Slight chance of rain showers, slight chance of
thunderstorms.
Wednesday Night through Thursday: Winds less than 25 kt. Local
rough seas.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...None.
RI...None.
MARINE...None.
&&
$$
SYNOPSIS...Sipprell/GAF
NEAR TERM...Belk/Sipprell
SHORT TERM...Sipprell
LONG TERM...GAF
AVIATION...Sipprell/GAF
MARINE...Sipprell/GAF
Area Forecast Discussion
National Weather Service Caribou ME
843 PM EDT Sat Jul 28 2018
.SYNOPSIS...
A cold front will slowly press across the area tonight and continue
to the east on Sunday. High pressure will build south of the region
Monday and continue southeast on Tuesday. Low pressure will approach
Tuesday night and track west of the state on Wednesday.
&&
.NEAR TERM /THROUGH SUNDAY/...
8:42 pm update: No significant changes at this time. We
continue to monitor convection across central and northern
portions of the FA. The convection is becoming more elevated
with time, and there will continue to be some strong storms with
the potential that one or two spots could have some damaging
wind or larger hail under the strongest cores. Fog is once again
forming along the coast with the vsby 2 1/2 miles at Bar
Harbor, and 1/2 mile at Eastport; and likely lower in spots.
Previous discussion:
Cells starting fire and build. Severe tstm moved from Stockholm
through Van Buren. Other pulse cells further s and w showing
signs of building. Good environment for the pulse storm will the
mid level cooling. There was good movement to these cells at 25
mph. Will continue the enhanced wording of hail and strong wind
gusts into the evening as that mid jet streak help to build the
storms. SPC meso analysis site showed good bulk shear of 40 kts
in 0-6km layer. SB CAPE around 1500 joules. Another of concern
will be back across the Penobscot Valley as SPC has shifted the
Marginal Risk line further s to cover this area. Activity will
weaken after dark w/the loss of heating. There should be more
activity later at night as the cold front begins to move across
the region later tonight into Sunday morning. The HRRR continued
to do fairly well along the the latest NAM and RAP. Decided on
this blend for the forecast into tonight. Will keep the mention
of tstms for the overnight period w/the 2nd round of activity.
Winds will start to veer to the w by sunrise Sunday. Overnight
temps will be in the 60s w/dewpoints falling back. Fog once
again will be a concern across the Downeast including the coast.
As a matter of fact, fog will be a factor across northern and
central areas by early Sunday morning w/the moist llvls.
Sunday will start out w/clouds and some fog. Improvement should
take place by mid morning as drier air works its way into the
region behind the cold front. The NAM and GFS should like QPF
across the far northern areas. CAPES of 700-1000 joules are
noted across the northern and western areas and 0-6km shear of
20+ kts is noted. Given what the sounding profiles indicate,
moisture looks limited to the 850mb layer. Therefore, decided to
go w/just showers and left the mention of tstms out of the
forecast. It will be seasonal w/daytime temps in the upper 70s
and lower 80s.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
High pressure building toward the Mid-Atlantic region will bring a
mostly clear sky Sunday night. The air will be a bit dryer than it
has been recently with dew points in the mid 50s in most place,
as compared to the upper 60s which we have had for several
days. High pressure will build to our south on Monday bringing a
sunny to partly cloudy and warm day. The high will then slide
to the east, southeast on Tuesday as upper level ridging builds
across the northeast. This will bring a warmer day on Tuesday
with highs approaching the mid 80s in many areas under a mostly
sunny sky.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
Our focus going into the mid-week period will be on a new trough of
low pressure digging south of the Great Lakes. This trough will
support surface low pressure developing in the eastern Lakes
Tuesday night then tracking up to our west on Wednesday.
Forecast guidance has been consistent in showing most of the
rain from this system falling along a frontal boundary across
far northern Maine Wednesday into Wednesday evening. Some
northern and western area may get over an inch of rain through
Wednesday evening with lighter more showery rains further south.
Showers should taper off late Wednesday night. Looking ahead to
Thursday into Friday, the subtropical Bermuda high is expected
to rebuild southeast of the Mid-Atlantic coast Thursday into
Friday pushing warm and humid air north into our region. A
frontal boundary will remain across northern areas bringing a
chance for showers and Thunderstorms late in the week. The best
chance for thundershowers will be on Friday as a shortwave
approaches from the west and pushes into our warm and humid air.
&&
.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
NEAR TERM: VFR at the northern terminals this evening outside of
any convection. Conditions have now lowered to LIFR to IFR at
the Downeast terminals. The VFR will lower to LIFR to IFR at the
northern terminals overnight in lower clouds and some fog.
Improvement to VFR expected by mid morning on Sunday for all
terminals.
SHORT TERM: VFR conditions are expected to persist
Sunday night through Tuesday. Conditions will likely drop to IFR
Tuesday night as lower clouds move in, and remain IFR in low
clouds and showers on Wednesday.
&&
.MARINE...
NEAR TERM: The only headline is for a Beach Hazard for Paddle
Craft. The Paddle Risk ran high for Hancock County and moderate
for Washington County. Coordinated w/the USCG on a Beach Hazard
Statement for Sunday. The USCG wanted to have both coasts put
in the statement. The Beach Hazard runs through 8 PM Sunday.
Winds will be no higher than 15 kts into Sunday and this will
be across the outer zones. For the most part, stayed w/10 kts
through Sunday using a NAM/GFS blend. Seas were running 3-4 ft
and that should hold into Sunday. The local wave model was
handling things well w/keeping seas no higher than 4 ft.
Areas of dense fog are expected over the waters into Sunday
morning.
SHORT TERM: A few winds gusts may approach 25 kt over the
offshore waters late Monday as high pressure builds south of the
region. Otherwise, winds and seas are expected to be below SCA
Monday through Tuesday. Winds may gust up to 25 kt Wednesday and
seas may build over 5 ft in response to an increasing SSW wind
as the subtropical high rebuilds during the mid to late week
period.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...Beach Hazards Statement from 8 AM EDT Sunday through Sunday
evening for MEZ029-030.
MARINE...None.
&&
$$
Near Term...CB/Hewitt
Short Term...Bloomer
Long Term...Bloomer
Aviation...CB/Hewitt/Bloomer
Marine...CB/Hewitt/Bloomer
Area Forecast Discussion
National Weather Service Green Bay WI
1057 PM CDT Sat Jul 28 2018
Updated aviation portion for 06Z TAF issuance
.SHORT TERM...Tonight and Sunday
Issued at 522 PM CDT Sat Jul 28 2018
Scattered showers and isolated thunderstorms formed across the
far north, while isolated showers were noted across central
Wisconsin into the Fox Valley. Temperatures this afternoon
were mainly in the 70s, with Waupaca the warm spot at 80
degrees.
Isolated to scattered showers and storms will continue for the
rest of the afternoon. The greatest concentration of rain
will be north of Highway 10. Still some concern on the ending
time of the rain across the area this evening. Currently have
precipitation ending by 11 pm, however latest HRRR model run
suggested it could be an hour or two later. Later tonight, some
patchy fog is possible across central and north-central Wisconsin.
Lowered minimum temperatures across the north based on what
happened last night.
On Sunday, the combination of cyclonic flow aloft plus daytime
heating is expected to kick off more shower and storms during
the afternoon. Bufkit soundings indicated 500 to 900 J/KG of
cape and mid level lapse rates around 6.5 C/KM. Current thinking
is the greatest concentration of showers and storms will be across
the north. Took a blend of guidance values for highs on Sunday.
.LONG TERM...Sunday Night Through Saturday
Issued at 522 PM CDT Sat Jul 28 2018
Broad upper trough across the Great Lakes will make
for scattered afternoon or evening thunderstorms Monday and Tuesday
but it will be dry most of the time with seasonable temperatures.
A better chance of showers and thunderstorms is Wednesday afternoon
and night as a sharper upper system and cold front approach. Highs
Wednesday could be several degrees above normal if the front slows
down.
Cooler and mostly dry weather should follow Thursday and Friday.
Saturday will be warmer as the surface high moves off to the east.
Some showers and thunderstorms are possible Saturday afternoon or
night as a modified Pacific cold front approaches.
&&
.AVIATION...for 06Z TAF Issuance
Issued at 1056 PM CDT Sat Jul 28 2018
Generally VFR conditions through the TAF period. Overall large-
scale pattern will not change much over the next 18 to 24 hours
with cyclonic upper-level flow with occasional upper-level
impulses moving across the area.
Overnight, residual mid-level clouds AOA 7KFT can be expected
mainly over the southern half of the forecast area. Over parts of
central and northern Wisconsin, patchy fog can once again be
expected especially north of highway 29 including the RHI TAF
site. Winds will be light and variable tonight.
Cyclonic upper-level flow and a weak upper-level impulse will
again lead to increasing afternoon convective clouds over much of
the forecast area. Isolated to scattered showers will be possible
again just about anywhere across the forecast area, but will
likely be a bit more widespread across central and northern
Wisconsin. Will be a bit more instablity in place on Sunday
afternoon, thus an isolated thunderstorm is possible especially
west and north of the Fox Valley after 21 UTC Sunday.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....Eckberg
LONG TERM......RDM
AVIATION.......ESB
Area Forecast Discussion
National Weather Service Wichita KS
634 PM CDT Sat Jul 28 2018
.SHORT TERM...(This evening through Monday night)
Issued at 315 PM CDT Sat Jul 28 2018
Latest satellite and radar imagery shows a developing cumulus
field across southeast Kansas mid-afternoon as the bulk of
thunderstorms remain located to both the north and south of the
county warning area. A few scattered thunderstorms will be
possible this afternoon and early evening in southeast Kansas
along an axis of surface-based CAPE east of the Kansas Turnpike.
Will continue to monitor the radar, though this activity should
wane after sunset when attention will then turn to more storm
chances later this evening and tonight.
The main challenge with the forecast during the short term is the
timing of expected widespread showers and thunderstorms over the
forecast area this evening and tonight. Another mid/upper level
disturbance is expected to initiate convective development over
the High Plains in northeast Colorado and northwest Kansas this
evening in a similar fashion as yesterday evening. A resulting
mesoscale convective complex (MCS) is forecast to then progress to
the southeast toward the forecast area, aided by strong
northwesterly flow aloft. Once again, the greatest instability
will be in northwest Kansas, where MLCAPE over 3000J/kg, lapse
rates in excess of 8 degrees C/km, and bulk shear in excess of
50kts will be located in a weakly capped environment. However,
though not as strong as in the northwest part of the state,
moderate instability is expected in central and south central
Kansas later this evening and overnight, when the MCS is expected
to arrive into the area. This will bring chances for strong and
severe storms, with damaging winds as a primary concern, though
localized flooding and hail remain a possibility as well. The best
chance for severe storms appears to be along and west of the
I-135 corridor, though strong to marginally severe storms could
certainly make it a little further to the east.
As previously mentioned, the main forecast challenge has been the
time of arrival of convective activity this evening and
overnight. Convective-allowing models (CAMs) including the RAP and
HRRR performed poorly during yesterday evening`s event with time
of arrival into central Kansas, lagging about 4-5 hours behind
what actually occurred. With a similar setup as yesterday for
tonight, confidence in these short term models regarding timing is
fairly low at this point. In collaboration with surrounding
offices, have included slight and chance pops in central Kansas by
02-03z, with the better chance for storms beginning around
midnight or slightly after. To add to the complexity, the NAM and
increasingly other short range models are trending toward the
possibility of a split occurring, where two complexes diverge to
coincide with two separate areas of maximum CAPE. In this
scenario, it is possible that the Dodge City and Topeka county
warning areas could get the brunt of the activity with the western
complex having the greatest strong/severe potential. In this
case, portions of south central Kansas would be on the edge of
both complexes. Have kept a blended approach in the forecast with
higher confidence in seeing showers and storms develop over a
larger portion of the area during the overnight hours tonight
versus last night.
MCS is expected to move off to the east Sunday morning creating a
lull in activity for most of the area Sunday afternoon/evening
before another shortwave dives out of the Rockies and into Kansas
Sunday night through Monday afternoon bringing more chances for
showers and storms, though with marginal instability, widespread
severe weather is unlikely.
Kept highs unseasonably low on Sunday and Monday with storm
chances and thick cloud cover expected across the region.
.LONG TERM...(Tuesday through Saturday)
Issued at 315 PM CDT Sat Jul 28 2018
After showers and storms move to the east of the area Monday
afternoon, the upper trough will continue to move off across the
Mississippi Valley Tuesday which will mark an end to the precip
chances over central, south central, and southeast Kansas. Models
remain in good agreement that the forecast will remain dry through
the rest of the work week next week. A gradual warm-up will begin
by Wednesday with highs returning to the low to mid 90s by next
weekend.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 635 PM CDT Sat Jul 28 2018
Challenging aviation forecast continue. Still some consensus that
MCS should track across the area overnight. Have worded TAFs with
that scenario with temporary MVFR conditions for the storms.
Assuming that goes as planned, daylight hours would likely be rain
free with subsidence behind MCV, otherwise there will be a chance
of isolated to scattered storms in the afternoon. -Howerton
&&
.PRELIMINARY POINT TEMPS/POPS...
Wichita-KICT 69 83 67 82 / 80 30 40 30
Hutchinson 68 82 65 80 / 80 20 40 30
Newton 67 81 64 80 / 80 20 30 30
ElDorado 67 81 64 80 / 70 30 30 30
Winfield-KWLD 69 84 66 82 / 80 30 40 40
Russell 66 80 62 79 / 70 20 40 20
Great Bend 66 81 63 80 / 80 20 40 20
Salina 68 82 64 81 / 70 20 30 30
McPherson 67 82 64 80 / 80 20 30 20
Coffeyville 70 84 66 82 / 70 60 40 40
Chanute 68 82 65 81 / 70 50 30 30
Iola 68 82 65 81 / 70 50 30 30
Parsons-KPPF 69 83 67 81 / 70 60 40 40
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SHORT TERM...TAV
LONG TERM...TAV
AVIATION...PJH
Area Forecast Discussion...UPDATED
National Weather Service New Orleans LA
1001 PM CDT Sat Jul 28 2018
.UPDATE...
Cleaned up PoPs and weather grids to bring in line with current
radar and observation trends. Kept 50% or so near the coast and in
coastal waters where land breeze enhancement will likely maintain
maritime convection much of the night. RAP shows some
redevelopment of thunderstorms near Hattiesburg overnight that
spreads southward in the pre-dawn hours. The HRRR does not support
this. At this time, will indicate low end PoPs through 12Z then
maintain the 40-50% after 12Z from previous package. No other
changes at this time.
&&
.AVIATION...
Pretty unstable conditions with synoptic scale lowering of heights
in response to increased troughing aloft to make timing out
convection difficult next 24-48 hours. Some indications of early
onset, near daybreak, at some of the terminals. VFR conditions
outside of convection. 24/RR
&&
.PREV DISCUSSION... /issued 845 PM CDT Sat Jul 28 2018/
SOUNDING DISCUSSION...
Mid level moisture has increased substantially from 24 hours ago.
This is biggest change is seen 850-600mb level. This change
caused the PW to jump from 1.4" yesterday to 2.1". A dry exists
just above 600mb. This, combined with a fairly steep lapse rate
from 850mb to 600mb, is providing a marginally conducive
environment for strong downdraft winds. The result from all the
above has been an increase in convective coverage and intensity
compared to previous days. This airmass will likely remain in
place for at least a few days albeit small modifications.
MEFFER
PREV DISCUSSION... /issued 343 PM CDT Sat Jul 28 2018/
SHORT TERM...
Weather across region will be transitioning to wetter pattern as
an unseasonably deep mid level trough slowly deepens through mid
week from the Great lakes to Gulf south region. Weak short waves
moving through the deepening mid level trough and associated
surface boundary combined with ample instability and daytime
heating should promote above normal rain chance...in the 60 to 70
percent. Scattered to locally numerous showers and thunderstorms
should persist into the evening hours each day. Precip water is in
the 1.8 to 2.1 range, so locally heavy rain will be the primary
hazard with the thunderstorm activity.
In very short term...short term convective models suggest
scattered strong convection should persist into this Saturday
evening...especially west of I-55 as convection in central
Louisiana drifts southward, so kept scattered showers and
thunderstorms well into the evening hours most area.
LONG TERM...
A weak surface front is expected to be draped across our area on
Wed and slowly begins to dissipate over the following two days.
Some drier air may moved into the northwest portion of the
area...mainly across southwest MS and areas north of Baton Rouge
with lower rain chances in those area. With the weakening
surface boundary and persistent mid level trough in area....rain
chances will be near to above normal from MS coast into southeast
Louisiana with some threat of locally heavy rain. By next
weekend, mid level ridge builds over region with rain chance
returning to more normal levels. Temperatures should remain near
or slightly below the seasonal normals.
AVIATION...
VFR conditions are expected to prevail through Sunday. The
exception will be in and near scattered afternoon and evening
SHRA/TSRA where briefly lower MVFR to IFR conditions and gusty
winds generally up to 30 knots will be possible.
MARINE...
A light to occasionally moderate south to southwest wind flow will
persist across the marine area into mid week as a weak front
approaches the area from the north. Shower and thunderstorm
coverage will be above normal through early and mid part next
week. The front boundary should weaken and dissipate mid week
north of the coastal waters with winds becoming light southerly in
the latter half of the week.
DECISION SUPPORT...
DSS code: Green
Deployed: None
Activation: None
Activities: None
Decision Support Services (DSS) Code Legend
Green = No weather impacts that require action.
Blue = Long-fused watch, warning, or advisory in effect or
high visibility event; Marginal risk severe or excessive rain.
Yellow = Heightened impacts with short-fused watch, warning or
advisory issuances; radar support for Slight risk severe or
excessive rain.
Orange = High Impacts; Enhanced risk severe; nearby tropical events;
HazMat or other large episodes.
Red = Full engagement for Moderate to high risk of severe and/or
excessive rain; direct tropical threats; Events of National
Significance.
&&
.PRELIMINARY POINT TEMPS/POPS...
MCB 73 93 73 91 / 10 50 20 70
BTR 76 92 75 92 / 10 60 30 60
ASD 76 92 76 91 / 20 50 30 60
MSY 79 93 78 91 / 20 50 30 60
GPT 77 91 78 91 / 20 50 20 60
PQL 75 94 76 91 / 20 50 20 50
&&
.LIX WATCHES/WARNINGS/ADVISORIES...
LA...None.
GM...None.
MS...None.
GM...None.
&&
$$
Area Forecast Discussion
National Weather Service Medford OR
252 PM PDT Sat Jul 28 2018
.DISCUSSION...The region remains high and dry under high pressure
this afternoon. The main center of high pressure is located near
Las Vegas but a ridge axis extends northwest to the south Oregon
coast and is rotating north and east across the area today
through tonight. This is keeping things fairly warm and stable.
Satellite shows smoke from the Garner and South Umpqua Complexes
lofting and surging east and northeast as of about 2pm. It looks
like another afternoon/evening surge of thicker smoke will impact
the Rogue Valley. The HRRR smoke model has been doing fairly well
in advertising this trend.
Not much changing into Sunday. But later Sunday into Monday we`ll
see some greater effects from a low pressure system seen offshore
in water vapor imagery beyond 130W from California. Shortwave
energy within the low will continue lift north across about
40N/130W. This will provide increasing south flow aloft and
increasing mid level moisture. Precipitable water values are
forecast to jump up about a quarter inch and stability will be
decreasing. The mountains will see some cumulus with this but
we`re holding off on the mention of thunderstorms as it still
appears too dry at this time. Some chances around 10 percent are
in the forecast across the Cascades around Crater lake and areas
east of there. The Cascades and northern Klamath county will see
Haines numbers fall due to the moisture component. Smoke movement
will be more toward the north.
Mid to late week will be characterized by a faster SW flow aloft
as the ridge axis shifts well eastward. This will produce cooler
afternoon high temperatures and breezy onshore flow in the
afternoons and evenings. Really no appreciable chance of rain in
sight at this point, but for what it`s worth, the EC...if you`re
into 8-10 day deterministic forecasts...indicates that may change
with an approaching trough for some west side areas late next
weekend into early next week. Stavish
&&
.AVIATION...For the 28/18Z TAFs...Marine stratus is starting to burn
off near and along the coast. North Bend should clear out within the
next 20-30 minutes with VFR conditions the rest of the afternoon.
The marine stratus will be slower to burn off from about Gold Beach
south, but it should still clear out in these areas by mid
afternoon. The lower conditions will return to coast early this
evening and last into Sunday morning.
Elsewhere...VFR conditions will prevail through the TAF period,
except for areas of MVFR visibility in smoke and occasional IFR
visibility in smoke near fires. The smoke will be the worst late
this afternoon and tonight as it tends to settle in the valleys.
-Petrucelli
&&
.MARINE...Updated 200 PM PDT Saturday 28 July 2018...Offshore high
pressure and a thermal trough inland will persist through next week.
Moderate north to northwest winds are expected, but both winds and
seas will remain below advisory criteria through Wednesday morning.
The thermal trough is expected to strengthen by the middle of next
week and winds have a chance to approach advisory criteria in the
southern outer waters Wednesday afternoon or evening. Once they
return, they may last through the rest of the week, and there is a
possibility for gale force winds by late next week. -Petrucelli
&&
.FIRE WEATHER...Updated 200 PM PDT Saturday 28 July 2018...A Red
Flag Warning remains in effect from 2 PM through 10 PM PDT today for
gusty winds, low humidity, and Haines Index of 5 for portions of
Oregon zones 620 and 622. This includes the Garner Complex, the
northern portions of the Illinois Valley including Wilderville,
sections of the Applegate Valley, and the Rogue River Valley
eastward from around Grants Pass and Merlin to Trail/Shady Cove and
southward to Ashland.
Elsewhere, the current GOES 16 fire suite is showing a few hot spots
building near the Taylor Creek perimeter as well as for portions
of the Goodview Fire in the South Umpqua Complex.
Overall, the day-to-day change in conditions from yesterday through
the weekend will be minimal. It will still be extremely hot and dry
with breezy afternoon and evening northwest to north winds, but it
is a small consolation that the slight changes will be trending in
the desired direction of weaker winds and higher humidity. The high-
level Haines will continue to be a 5 for most of the area. As a
result, despite widespread conditions trending the way they are, the
Taylor Creek Fire in the Garner Complex will still locally see
weather conducive to significant fire spread over the next few days.
A pattern change is expected come mid-week as the ridge shifts
eastward and leaves us in more diffluent southerly than zonal
westerly flow aloft. This southerly flow will bring moisture up from
the Pacific. The most likely scenario with this pattern involves an
increase of high clouds across the area with scattered coverage of
late day cumulus buildups over the higher terrain. This weak
instability is likely to shift to solely east of the Cascades on
Tuesday as the offshore low continues its slow movement northeast
into the Pacific Northwest. As it does so, the influence of the low
upon our weather will grow through mid-week. This will bring a
cooling trend with inland temperatures back closer to normal for the
latter portion of the week. However, it will also bring stronger
west to northwest winds that will be strongest east of the Cascades.
With humidity values still low, especially east of the Cascades,
critical fire weather conditions will be possible. -Schaaf/DW
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...Red Flag Warning until 10 PM PDT this evening for ORZ620-622.
CA...None.
Pacific Coastal Waters...None.
$$
Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
807 PM CDT Sat Jul 28 2018
.UPDATE...
Issued at 759 PM CDT Sat Jul 28 2018
Updated to include 00z aviation discussion below.
&&
.SHORT TERM...(This evening through Sunday)
Issued at 252 PM CDT Sat Jul 28 2018
Visible imagery shows widespread cu across the area this
afternoon, with showers and a few thunderstorms generally north of
I-94 where the RAP shows MLCAPE in the 200-500 J/Kg range. The
GOES-16 GLM has done a nice job of highlighting where lightning
has been occurring, and has generally shows it remaining mostly
with the activity near the northern edge of the forecast area.
Shortwave trough evident in water vapor imagery over the western
part of the forecast area at the current time will swing east
through the evening, helping to keep the SHRA/TSRA activity going,
although it should get too far south of I-94 with much less
instability to the south. Some convection will linger into the
evening, mainly north of I-94 and east of I-35, then we should see
mostly clear skies for the rest of the night. We`ll have a repeat
of sorts on Sunday as the shortwave trough currently near the
Alberta/Montana border swings through the region and helps
generate convection as instability builds during the afternoon
once again. It looks like the activity will be a bit more
widespread with instability AOA 500 J/Kg for much of the area.
.LONG TERM...(Sunday night through Saturday)
Issued at 252 PM CDT Sat Jul 28 2018
Some diurnal convection may linger into Sunday evening, but
otherwise we should dry out and see mostly clear skies once again.
Decent lapse rates will linger over the southern portion of the
area on Monday, so can`t rule out an afternoon shower/thunderstorm
in that area, otherwise things should be dry across the area. Dry
weather and a brief period of return flow will setup Monday night
and Tuesday before a cold front drops into the area Tuesday night
and Wednesday. The frontal timing and degree of moisture return
ahead of it suggest mainly scattered precipitation with the FROPA,
from late Tuesday night into Wednesday evening as the front drops
in from northwest to southeast. High pressure will build across
the area Thursday and Thursday night with seasonably cool and dry
weather expected. We`ll see more robust return flow and moisture
advection by Friday as a warm frontal boundary lifts north through
the area. The model guidance is in decent agreement on the
general evolution of things in terms of a significant warm-up and
return of humidity Friday into Saturday, but there is substantial
spread in the details. The pattern would suggest the potential for
a couple of MCSs in the area during that time period as the warm
frontal boundary is in the region and a cold front tries to
approach from the west with a shortwave trough moving east near
the US/Canada border. For now, will have high chance PoPs for much
of the time period with the understanding that the timing and
PoPs will get refined as things get closer in time.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 759 PM CDT Sat Jul 28 2018
Isolated -SHRA/-TSRA just enough to impact a couple TAF sites at
initialization, particularly KMSP. Other TAF sites will remain at
VFR into the early morning hours. Pre-dawn ground fog looks to be
a concern near TAF sites that had showers today so have
highlighted with TEMPO groups those sites which may have some MVFR
fog going into sunrise. Little change in the synoptic scenario is
expected for tomorrow so will again look for isolated -SHRA/-TSRA
to develop Sunday afternoon-evening. Have only gone with VCSH at
this point to highlight the potential for showers but VCTS or
-TSRA certainly cannot be ruled out. Even so, not looking for
anything worse than VFR.
KMSP...Had to initialize with the TSRA over MSP, lasting through
the first hour, then improving conditions thereafter. The rainfall
near an dover MSP improves the odds for fog during the early
morning hours, especially with light to calm winds. Sunday
afternoon may well again feature isolated -SHRA/-TSRA so have
included VCSH at this point.
/OUTLOOK FOR KMSP/
Mon...VFR. Wind NW 5 kt.
Tue...VFR. Wind W 5 kt.
Wed...VFR. Chc -shra/-tsra. Wind N 5-10 kts.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
&&
$$
UPDATE...JPC
SHORT TERM...
LONG TERM...
AVIATION...JPC
Area Forecast Discussion
National Weather Service Phoenix AZ
204 PM MST Sat Jul 28 2018
.SYNOPSIS...
A major upswing in storm activity is anticipated over the Arizona
deserts this afternoon and evening. Winds could be strong enough
to cause minor damage. At a minimum, anticipate large swaths of
strong winds causing areas of dense blowing dust. There is also
the potential for brief heavy rain but that will be less
widespread...with best chances over south-central Arizona
declining to slight chances over southeast California. Storm
chances and slightly above normal temperatures will continue
through most of next week with an increase in tropical moisture
possible by next weekend.
&&
.DISCUSSION...
Moisture levels have increased today compared to yesterday. This
is evident not only in soundings from earlier today but surface
dew points for early this afternoon. This morning`s soundings also
showed some cooling roughly in the 850-700 mb altitudes. Thus
there is more CAPE and less CIN than yesterday. Anticipate some
decrease in those dew points with continued mixing which will aid
the DCAPE values. Steering flow is northeasterly. Thus, the stage
is set for higher terrain storms over central and southeast AZ to
propagate to the lower elevations of central AZ followed by
subsequent westward propagation. Multiple runs of HRRR based
guidance has been aggressive in it`s depiction of convection over
our forecast area for this afternoon and evening - especially for
areas west of metro Phoenix over northwest Maricopa County. Of
note, there has been a slight downtrend in latest runs. The more
noticeable trend is with a slower arrival of storms. However, it
is also behind with ongoing convection. HREF also indicates that
storm coverage over metro Phoenix will not be widespread but
become better to the west. In general, there is a mixed bag of
solutions amongst the CAMs (as usual). The NCEP WRF-NMM struggles
to produce much of anything over metro Phoenix though its cousin
the ARW is more generous. The NAM Nest fizzles storms over the
southeast Valley. Perhaps the most surprising is the UofA WRF-GFS
which is often the most aggressive yet it indicates only modest
activity. One area of agreement amongst these models is that
southeast AZ, in particular Pima County (and areas just south of
the Mexico border), will be very active and produce far reaching
outflows. To varying degrees, they also agree on the idea of
outflow from Pima County encountering outflow from Gila/Yavapai
Counties. With these outflows, there is good potential that CIN
will be overcome for a lot of south-central and southwest AZ -
less likely over southeast CA.
The main takeaway is that there will be large swaths of strong
outflow winds which will cause a lot of dense blowing dust. Thus,
the advance notice Blowing Dust Advisories. In some areas,
including metro Phoenix, winds will be strong enough to damage
trees and weak structures (e.g. aluminum awnings). There is also
the potential for more localized but more robust wind damage
(from straight line winds). Storms will be capable of brief heavy
rain and anticipate minor nuisance flooding will be common. More
significant flooding is also possible but in much more localized
areas. Of note, both SPC and WPC have identified much of our CWA
as having potential for severe weather and excessive rain
respectively. This of course does not mean that everyone
everywhere will experience a major storm. Especially when it comes
to rainfall, expect dramatic variations over small distances.
Isolated to scattered showers and thunderstorms over the higher
terrain north and east of Phoenix are expected again tomorrow,
though dynamic forcing should be weaker with the inverted trough
pushing into the Pacific Ocean. Complex outflow boundary
interactions over the lower deserts will be less likely as the
steering flow becomes a bit more uniform across the region out of
the east-southeast. Whether or not outflows will be able to
trigger new convection over the lower deserts will depend on how
worked over the atmosphere is from today and tonight. Considering
we do expect today to be relatively active, we have continued
tapering POPs back a bit for tomorrow, but if this does not
materialize POPs may be raised. High temperatures tomorrow should
decrease a few degrees from today, closer to seasonal normals.
Moisture levels will continue to remain elevated with shower and
thunderstorm chances continuing through at least the second half
of next week. Slightly drier continental air may drift into the
region from the northeast on Monday, but a pair of weak troughs
rotating around the persistent ridge of high pressure may help
increase thunderstorm coverage on Tuesday or Wednesday and again
on Thursday or Friday. The first trough will be associated with a
tail of energy splitting off from a positively-tilted trough that
pushes through the Midwest, while the second may be convectively
reinforced by a complex developing along the front range of the
Rockies in northwest flow. Although these features are very subtle
and possibly beyond the limits of predictability, it seemed wise
to keep POPs elevated through the period given abundant moisture
should remain in place. Temperatures should continue to run near
to slightly above normal given the presence of the ridge near the
region despite elevated moisture levels. These moisture levels may
become even more elevated by early the following week as both the
GFS and ECMWF show a tropical system developing over the East
Pacific.
&&
.AVIATION...
South-Central Arizona including KPHX, KIWA, and KSDL...
Through around 02Z, winds will remain out of the west aob 10 kts
with FEW to SCT mid and upper level clouds. Storm activity this
afternoon and evening should be more widespread than previous days
with a high likelihood of storm outflows moving into the metro from
an easterly component sometime between 02-04Z. With this outflow,
also comes the potential for blowing dust and visibility concerns.
In addition, there is moderate to high confidence that thunderstorms
will develop along this outflow boundary and push westward with a
few isolated strong to severe thunderstorms possible. As activity
moves over terminals, SCT to BKN cloud decks between 6 to 8 kft will
be likely and could possibly be even lower if storms move overhead.
Southeast California/Southwest Arizona including KIPL and KBLH:
Winds to favor the south at KBLH and the southeast at KIPL with
general sustained speeds of around 10 kts with a few gusts up to 20
to 25 kts during the afternoon hours. Some debris clouds from storms
in Arizona are likely this evening into tonight. There is at least a
slight chance of a storm outflow reaching the terminals late
tonight, but any storm activity should remain to the east of the
terminals. Although storm activity should remain limited, the
afomentioned outflow will bring the potential for blowing dust and
slight visibility concerns.
Aviation Discussion not updated for amended TAFs.
&&
FIRE WEATHER...
Tuesday through Saturday:
Monsoon moisture will linger over the region through next week but
with slightly lower minimum humidity levels as compared to the
preceding couple of days. At least slight chances of thunderstorms
will continue - mainly over the typical favored areas of south-
central AZ. Otherwise, minimum relative humidity values will
remain above 15 percent with overnight recovery remaining at least
fair if not good. Apart from thunderstorms, winds will generally
be light except for customary afternoon and evening breeziness.
&&
.SPOTTER INFORMATION STATEMENT...
Skywarn amateur radio Nets may need to be activated for this
afternoon and evening. Spotters should follow standard reporting
procedures.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...Blowing Dust Advisory until 10 PM MST this evening for AZZ534-
537>540-542>544-546-548-550-551-553>555-559.
Blowing Dust Advisory from 6 PM this evening to midnight MST
tonight for AZZ530>533-535-536.
CA...Blowing Dust Advisory from 6 PM this evening to midnight PDT
tonight for CAZ562>570.
&&
$$
DISCUSSION...AJ/Hopper
AVIATION...Hernandez
FIRE WEATHER...AJ
Area Forecast Discussion
National Weather Service Blacksburg VA
958 PM EDT Sat Jul 28 2018
.SYNOPSIS...
A weak area of high pressure will build to our north tonight,
while a cold front will stall across the central Carolinas and
eastern Virginia. The front should then return north Sunday into
Monday as low pressure aloft reestablishes itself across the
eastern United States. Unsettled, wet weather is expected to
return early next week and remain in place through much of the
week.
&&
.NEAR TERM /THROUGH SUNDAY NIGHT/...
As of 955 PM EDT Saturday...
Surface ridge building eastward across the Appalachians and northern
mid-Atlantic region from a broad anticyclone centered over northern
IL. Broad cyclonic west flow aloft is maintained though with lower
humidity levels for most of the Blacksburg forecast area. Have
left a low probability of showers late tonight in the piedmont
of Virginia and North Carolina based on the last few runs of the
HRRR and RAP.
The NAM and to a more limited extent the GFS generate some
lower clouds (at least partly to mostly cloudy skies) east of
the Virginia and North Carolina. The far western mountains stand
the best chance at seeing patchy fog, but afternoon dewpoints
have really fallen rather appreciably so less confidence on fog
here but did include some patchy largely river valley fog for
areas along the Greenbrier, Bluestone and New River valleys.
For Sunday and Sunday night...the slow-moving frontal boundary then
begins to return northward as a warm front. With it will begin a
renewed period of near daily rain chances. Moisture from the
south/southeast will continue to advect northward allowing for
continued partly to mostly cloudy skies, tending more mostly cloudy
as the afternoon and evening progresses. A shortwave trough now
responsible for convection in the lower Mississippi Valley this
afternoon will pinwheel around the broad cyclonic flow, setting its
eyes on the southern/central Appalachians for the afternoon and
evening hours. This will lead to PoPs increasing from southeast to
northwest Sunday and Sunday night.
By Sunday afternoon/evening, shown solid chance for showers
with slight chances for thunderstorms. This precip will likely
be falling into a residual surface ridge/weak wedge so despite
increased moisture/humidity levels, rainfall rates and
intensities should be more gradual. But the message overall is
that we`re trending into a wetter pattern again, and
particularly into early next week. Highs should be in the low-
mid 80s Sunday, with lows in the 60s.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
As of 257 PM EDT Saturday...
A closed low will develop over the Mississippi valley early next week,
then fill and rejoin the mean flow midweek as energy looks to phase
with a more shallow trof moving across southern Canada. This will
establish a southwest wind flow and allow for deep moisture transport
into the region from the Gulf, with active/unsettled conditions through
Wednesday.
On Monday, a weak wedge signature will remain in place as short wave
energy and some isentropic lift slide up from the south. Ample
instability will develop by the afternoon and this should aid in
development of showers and thunderstorms, and influence of wedge will
contribute to some shear. This combination of features looks to combine
for decent convective development with robust storms featuring locally
heavy rain and a severe threat, mainly from clustering storms. Expect
convection to exhibit a typical diurnal trend and continue into Monday
evening before dissipating Monday night.
As the upstream closed low over starts to slowly eject out of the
Mississippi valley it will push an ill defined frontal boundary in our
direction that will meet a good deal of resistance from the Bermuda
high off the Atlantic coast. The Appalachians and central mid Atlantic
region will get squeezed between these systems and enhance low level
flow with numerous short wave impulses streaming in from the southwest.
850mb winds increasing to somewhere around 30kt by Tuesday afternoon
will yield a good deal of shear and instability will be substantial.
The result will be an opportunity for rounds of robust convection both
Tuesday and Wednesday afternoon/evenings. Expect storms to present a
severe threat with some degree of organized clusters/line segments,
along with hydro issues due to locally heavy rain with precipitable
water values once again topping 2 inches in some locations. Will be
watching how this situation develops very closely over the next few
days.
With a good deal of cloud cover expected expect high temperatures a few
degrees below normal, while mins run normal to slightly above.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
As of 257 PM EDT Saturday...
Thursday appears quite wet once again with the potential for more
strong to severe storms with locally heavy rainfall. The degree of
flood threat by late in the week will depend in large part on where
rainfall is distributed earlier in the week, but local problems are
certainly possible as the airmass remains juiced. As the upper pattern
trends to a more zonal regime, the Bermuda high off the coast looks
like it will be suppressed southward a bit. This may be enough to allow
the frontal boundary to sag southward and eastward by the end of the
week to gradually lessen our chances for thunderstorms by the weekend.
However guidance is not clear cut and the front may remain stalled over
the region with much higher chances for heavy rainfall. Will have to
wait for later guidance to see what direction the trends will take.
Temperatures will generally be on the cool side of normal for the end
of the workweek.
&&
.AVIATION /02Z SUNDAY THROUGH THURSDAY/...
As of 740 PM EDT Saturday...
Removed the VCSH from eastern tafs because anticipated coverage
will be isolated in nature with better lift along the frontal
boundary located east of forecast area tonight. SCT to BKN VFR
Cu fields with bases around 3500-6000` will continue to
dissipate or diminish with the loss of solar heating.
The upper ridge shifts to our northeast, affording for some
east to southeast low-level moisture return westward. This may
manifest as a low VFR deck along/east of the Blue Ridge
overnight into Sunday morning, perhaps a outside chance at MVFR
ceilings in the early morning hrs.
There is a small window for radiational fog development
late tonight into Sunday morning. In the west, MVFR/IFR fog is
possible in the river valleys. Winds will be east/northeast 3-6
kts in the Piedmont, while becoming light/variable west of the
Blue Ridge. Morning low clouds and fog will lift or burn off
quickly Sunday morning. Expect SCT to OVC mainly VFR ceilings
initially from the Blue Ridge westward for Sunday, but moisture
will continue to increase with clouds and showers and
thunderstorm chances spreading westward with time. The frontal
boundary lifts north as a warm front on Sunday. The best chance
for any thunderstorm will occur after 18z Sunday in the east.
Winds will be light east/northeast in eastern areas and more
variable/light in the west.
Medium confidence in ceilings,visibilities and winds during the
taf period.
Extended Aviation:
The front that will returns north Sunday afternoon and stalls
near the region early next week. Through Wednesday will be
mostly VFR to MVFR, outside of early morning fog/low clouds,
with the potential for multi periods of sub- VFR ceilings and
visibilities in showers and thunderstorms each afternoon and
evening, especially Monday through Wednesday. The weather will
remain unsettled on Thursday with a good chance for IFR showers
and thunderstorms.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...None.
NC...None.
WV...None.
&&
$$
SYNOPSIS...AL
NEAR TERM...AL/AMS
SHORT TERM...MBS
LONG TERM...MBS
AVIATION...AL/KK
Area Forecast Discussion
National Weather Service Springfield MO
607 PM CDT Sat Jul 28 2018
.SHORT TERM...(This evening through Sunday)
Issued at 250 PM CDT Sat Jul 28 2018
A couple of upper level impulses are aiding in kicking off
thunderstorms. One over northeast OK/northwest AR and the other
over east central KS. Short term convective allowing models, most
notably the HRRR produce an increase in thunderstorm activity
from 3 pm to 9 pm over southeast KS/southwest MO. Instability
will be strongest over southeast Kansas and I-49 corridor in
Missouri where mlcapes are progged to be 1000-2000 j/kg. Isolated
strong/severe storms will be possible in these areas in the near
term with a wind/hail risk. Much lower instability is progged
farther east into the Ozarks including the KSGF area.
Guidance has been consistent with the development of an MCS over
NE/western KS later today and this evening. Convection should
gradually coalesce into a linear complex and shift east overnight
reaching our far western counties as early as 10z-11z/5am-6am.
We could see a strong to severe wind risk ahead of this line, but
in general the activity should be weakening by this time with
reduced instability. Will need to monitor trends.
The rain/tstms will continue to shift east into much of the rest
of the area during the morning hours with a remnant upper level
disturbance/mcv moving through the area. Will need to monitor for
pockets of instability and possible storm regeneration in the
afternoon around the periphery of heavier cloud cover and
mesoscale boundaries. The best chances for stronger instability
and a severe midday/afternoon storm risk look to be over far
southern MO but this is a low confidence risk at this point. We
are hoping for a good general rain Sunday to help ease drought
conditions.
.LONG TERM...(Monday through Saturday)
Issued at 250 PM CDT Sat Jul 28 2018
Monday-Tuesday: A more substantive shortwave is expected to move
southeast into the central Plains Monday and into central/southern
MO on Tuesday. Overall better chances for rain will be Monday with
chances starting to shift east on Tuesday.
Wednesday-Saturday: Once the shortwave kicks through we should
have dry or mostly dry weather Tuesday night through the end of
the week. The eastern extension of the upper level ridge over the
southwest U.S. looks like it will build into the central CONUS
late in the week, so expect cooler than normal weather Wednesday
to gradually warm to near or a little above normal by Friday and
Saturday.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 554 PM CDT Sat Jul 28 2018
Convective activity in the KJLN vicinity is expected to move out
of the area by 01z. Also, continuing to monitor the activity over
CO/WY this evening as convective models have this activity
congealing into a thunderstorm complex overnight and beginning to
move into the area after 09z.
Will initially see a line of thunderstorms as the complex
approaches with some MVFR conditions possible with the stronger
convective activity. After the initial line passes...will see
mainly shower activity with some thunderstorm regeneration
possible during the afternoon hours.
&&
.SGF WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&
$$
SHORT TERM...DSA
LONG TERM...DSA
AVIATION...Gaede
Area Forecast Discussion
National Weather Service Sacramento CA
150 PM PDT Sat Jul 28 2018
.SYNOPSIS...
Smoke will help to keep daytime temperatures cooler the next
couple of days. Then a gradual decrease in high temperatures is
expected next week but temperatures are expected to remain a
little above average.
&&
.DISCUSSION (TODAY THROUGH TUESDAY)...
Smokey conditions will make for a tricky forecast the next few
days especially over the north end of the valley where the smoke
is thick. The smoke has been keeping temperatures down over the
previous advisory area so have canceled the heat advisory. HRRR
smoke plume model keeps a similar type of smoke plume through
Sunday so I dont expect much change in Sundays high temperatures
over todays highs. Poor air quality can be expected the next
couple of days over the north end of the valley.
Further south the Delta breeze will continue remaining weaker
during the day and strengthening at night. The marine layer is at
around 1500 feet deep and should not change much over the next
couple of days.
&&
.EXTENDED DISCUSSION (Wednesday THROUGH Saturday)
The upper level ridge that has dominated the weather pattern for
the better portion of July will begin to shift eastward starting
the middle of next week. At the same time, a series of shortwave
troughs will pass through the Pacific Northwest, resulting in
lowering heights and increasing onshore flow. High temperatures
should trend back to within a few degrees of normal. Dry weather
will likely continue through the extended period.
Dang
&&
.AVIATION...
Widespread smoke and haze from wildfires are likely to bring
localized MVFR/IFR conditions tonight through Sunday. Winds
generally less than 10 kt, except gusts up to 30 kt near the
Delta.
Dang
&&
.STO WATCHES/WARNINGS/ADVISORIES...
Red Flag Warning until 8 AM PDT Monday for Eastern Portion of
Shasta/Trinity NF-Northern Sacramento Valley to Southern Tehama
County Line Below 1000 Ft-Southeast Edge Shasta-Trinity NF and
Western Portions of Tehama-Glenn Unit.
&&
$$
Area Forecast Discussion
National Weather Service Tampa Bay Ruskin FL
801 PM EDT Sat Jul 28 2018
.UPDATE...
Deep moisture across the area allowed for numerous
thunderstorms to develop across the interior this afternoon,
mainly along outflow and sea breeze boundaries. Although
much of this convection is now winding down as the sun sets,
scattered thunderstorms are still working west along the
Interstate 4 corridor into the Tampa Bay area, while an area
of stratiform showers are moving west across southwest
Florida. The HRRR and other high resolution models are
showing these showers and storms gradually dissipating
through around 11 PM EDT, with generally rain free
conditions then expected to hold overnight.
Overall, the forecast looks on track. Some minor
adjustments were made to the rain chances and weather
forecast for the next few hours to keep up with radar
trends. Otherwise, no changes are planned for the evening
update.
&&
.AVIATION...
Numerous thunderstorms are continuing to move west into the
Tampa Bay area along outflow boundaries, which will lead to
variable wind directions and periods of MVFR or brief
IFR/LIFR conditions through around 03z. Farther south, more
stratiform rain will impact KPGD/KFMY/KRSW through the next
couple of hours, with MVFR conditions possible. VFR
conditions should hold after 03z, until early Sunday
afternoon, when another round of thunderstorms develops
across the area.
&&
.MARINE...
Atlantic high pressure ridging into the eastern Gulf of
Mexico will support light south to southeast winds through
the next several days. Daily sea breezes will turn the winds
onshore near the coast. Although winds and seas will
generally remain below headline criteria, gusty winds in the
vicinity of daily thunderstorms will produce locally
dangerous boating conditions.
&&
.Preliminary Point Temps/PoPs...
TPA 77 90 77 88 / 40 40 30 50
FMY 75 89 75 88 / 30 50 40 60
GIF 74 92 75 90 / 30 60 40 70
SRQ 76 89 76 88 / 30 30 30 50
BKV 73 91 74 89 / 40 60 40 60
SPG 78 90 78 87 / 40 30 30 50
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...Beach Hazards Statement through Monday evening for Coastal
Charlotte-Coastal Lee-Coastal Sarasota.
Gulf waters...None.
&&
$$
UPDATE/AVIATION/MARINE...18/Fleming
UPPER AIR...42/Norman
DECISION SUPPORT...57/McMichael
Area Forecast Discussion
National Weather Service Topeka KS
1052 PM CDT Sat Jul 28 2018
.UPDATE...
Issued at 1052 PM CDT Sat Jul 28 2018
Subjective and objective analysis of the environment shows the
main axis of instability remains over western and central KS late
this evening. The last several runs of the HRRR have been
consistent in tracking the MCS along out southwestern boarder, and
now the new ARW/NMM/NAMNest show similar ideas. Have adjusted the
POPs over northeast KS to reflect the better chances for
thunderstorms to be over the southwestern counties. Although radar
has shown some elevated shower activity developing north of the
NEB state line, so there may still be measurable rainfall for
northeast KS. Within the instability axis, it looks like there
could still be a risk for sporadic damaging winds is a cold pool
can get organized. With indications this could impact areas from
Concordia to Emporia, will need to maintain a weather watch for
severe storms through the early morning.
&&
.SHORT TERM...(This evening through Sunday)
Issued at 330 PM CDT Sat Jul 28 2018
As of 19Z Saturday afternoon a murky surface pattern remains across
central and eastern KS. One feature of note -- a meso-low -- was
positioned across central KS in portions of Geary and Morris
Counties. To the south and east of this mesoscale feature, an area
of Cu has developed where maximum sfc has been ongoing --
temperature at EMP is 93. Recent visible satellite trends suggest
agitation increasing with storms developing in portions of Lyon and
Coffey Counties. Further development is expected through the
afternoon as inhibition continues to weaken along with continued
ascent provided by the meso-low. RAP analysis suggests up to 1500
J/kg of MLCAPE will reside across east-central KS -- primarily
east of Highway 77 and south of Interstate 70. Sufficient
effective bulk shear values near 30-35 kts should allow for
organized updrafts -- possibly supercells. The primary hazards
with the strongest updrafts include large hail and damaging winds.
As nocturnal cooling of the boundary layer ensues after sunset,
convection should diminish.
Late this evening into the overnight...
Our attention turns westward for additional thunderstorm activity
late this evening into early Sunday. Upslope surface flow
continues to reside across the High Plains with northwesterly mid
and upper level flow across the central US. Mesoanalysis suggests
a H5 speed max has overspread the central High Plains in portions
of WY and CO. Regional radar reveals developing convection from
southern CO to northern WY. Short term and CAM solutions suggest
multiple thunderstorm complexes are likely this evening into the
overnight. The first is developing within the Palmer Divide
region in eastern CO. General propagation should keep this MCS
west of the forecast area. The second potential MCS is developing
across eastern WY. Again, propagation vectors orientated towards
the southeast suggests this particular MCS would traverse the
entire CWA. Surprisingly enough, decent agreement exists amongst
short term and CAM solutions with the arrival time to north-
central KS in the 03z to 06z range. Latest trends from the RAP and
HRRR suggest WAA ahead of the MCS should yield an environment
comprised of MUCAPE between 2000-2500 J/kg. This thermodynamic
environment coupled with impressive midlevel flow for July
standards -- 35 kts at H7 -- should result in efficient convective
momentum transfer and subsequent potential for damaging winds.
Large hail is a potential as well given the moderate instability
and sufficient effective shear, although updraft interactions
should temper hail concerns. More importantly, confidence is
increasing for widespread heavy rainfall. Latest trends suggest
widespread amounts greater than a half-inch with localized higher
amounts.
Sunday...
Ongoing showers and storms are likely during the mid to late
morning hours as the remnants of tonight`s MCS exits the region.
The forecast then becomes complicated Sunday afternoon. Sunday
afternoon and evening`s thunderstorm potential is highly dependent
on tonight`s evolution. Persistent cloud debris through the day
tomorrow will limit storm potential. CAM and mid-range guidance
suggests additional thunderstorm development across the High
Plains tomorrow afternoon. Given the expected cloud debris across
eastern KS, any MCS progression would likely stay west of the CWA,
where better instability is expected to reside.
.LONG TERM...(Sunday night through Saturday)
Issued at 330 PM CDT Sat Jul 28 2018
The main midlevel trough is progged to eject into the upper
midwest region Monday into Tuesday. As a result shower and
thunderstorm chances will continue through Monday evening. A
drying trend should ensue thereafter as the midlevel ridge
amplifies in the western US with continued northwest flow across
the central US. Fortunately, a drastic warmup is not anticipated
through the week with temperatures in the 80s to near 90.
&&
.AVIATION...(For the 06Z TAFS through 06Z Monday)
Issued at 1052 PM CDT Sat Jul 28 2018
Will need to make some adjustments to the forecast for TOP and FOE
as the more intense convection looks to pass to the southwest.
Otherwise the overall thinking of the prev forecast has not
changed much. There still looks to be some MVFR CIGS through the
morning with some improvement through the afternoon.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Wolters
SHORT TERM...Baerg
LONG TERM...Baerg
AVIATION...Wolters