Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 06/27/17
Area Forecast Discussion
National Weather Service Albany NY
1025 PM EDT Mon Jun 26 2017
.SYNOPSIS...
An upper level disturbance will move across the region this
evening with mainly isolated to scattered showers and
thunderstorms. An upper level low and a cold front will bring
additional scattered showers and isolated thunderstorms on
Tuesday, with cooler than normal temperatures. High pressure
will build in from the Mid Atlantic Region by Wednesday, but
temperatures will still run slightly below normal for late June.
A warm front approaching from the southwest will bring more
showers and possible thunderstorms for Thursday.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
As of 1015 PM EDT, scattered convection continues with a couple
line segments moving through mainly north of the mid-Hudson
Valley. While expectations are this convection to slowly
diminish through the late evening hours, H2O vapor loop reveals
an enhanced mid level jet rounding the base of the upper low.
Some showers have developed across eastern PA which per the HRRR
may bring another round of showers just south of Albany
overnight. For now, we will introduce a slight chance PoP and
monitor trends. As for temperatures, where convection did
occur these values did drop back rather quickly. Overnight lows
look good per previous excellent forecast with no changes at
this time with regard to overnight lows. Did add some patchy fog
to the forecast/grids as well with moist lower level
environment, especially where precip occurred.
Prev Disc...
Latest WV satellite imagery suggests one small
upper level impulse tracking E/NE along the southern shore of
Lake Ontario, with another tracking E/NE across Lake Erie. The
combination of these two impulses will allow a continuation of
isolated to scattered showers/isolated thunderstorms to linger
well into this evening for areas mainly near and north of I-90,
with much less coverage, if any, to the south, which will be
farther from upper level dynamics and instability.
Again, any taller convective elements will continue to have the
potential to produce small hail/locally gusty winds this
evening, especially if any cells merge into small line
segments/clusters.
Convection should diminish toward and especially after midnight,
with partly cloudy skies continuing. Some patchy fog could form
in any areas which receive appreciable showers this evening.
It will be cool once again tonight, with lows mainly in the 50s.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY NIGHT/...
Tuesday, the main upper level trough is expected to slowly
translate east across the region during the late morning and
afternoon hours. The combination of forcing ahead of this
feature, and developing low/mid level instability with the cold
pool aloft and any breaks of morning sunshine should once again
contribute to scattered showers/isolated thunderstorm to develop
in the late morning through early evening hours, with the
greatest coverage once again expected mainly from the I-90
corridor and points north. Also, with low wet bulb zero heights
and still relatively strong winds aloft/evaporational cooling
potential, will continue mention of gusty winds/hail with
thunderstorms. Forecast soundings suggests similar SB CAPE
values to today, generally reaching 400-800 J/Kg, perhaps
locally higher where dewpoint pooling occurs. Highs should reach
the lower/mid 70s in valleys, with mainly 60s across higher
terrain, however temperatures will likely fall into the
50s/lower 60s once the core of any showers/storms pass by.
Tuesday night, any lingering convection should diminish fairly
quickly after sunset, with some clearing expected. Once again,
it will be cool, and some patchy fog will likely form in some
areas where appreciable showers occur prior to any clearing.
Lows mainly in the 50s, with some 40s possible, especially
across higher terrain.
Wednesday-Wednesday night, although the main upper level trough
should finally move east of the region, lingering cold air aloft
and possible weak disturbances rotating south/southeast on the
west side of the departing trough could initiate isolated
showers or perhaps a thunderstorm across portions of the
southern Adirondacks, the Lake George region and southern VT in
the late morning through afternoon hours. Otherwise, mainly
sunny and a bit warmer, with highs reaching 75-80 in valleys,
and upper 60s to lower/mid 70s across higher elevations. For
Wednesday night, clear to partly cloudy, with clouds more likely
to increase toward daybreak. Lows mainly in the 50s.
Thursday-Thursday night, increasingly active weather expected
once again, as a warm front approaches from the southwest. A
strong low/mid level jet max, with H850 winds 40-50 KT, will
impinge on western areas by late morning, and most central and
northern areas by afternoon. There could be some form of an MCS
spreading across central/northern areas late morning into the
afternoon, possibly in a weakening form, although new convection
could refire along its southern edge given the strong low level
warm advection. Trends will have to be watched. For now,
certainly expect showers and some embedded thunderstorms to
develop from W to E across the region during the late morning
through afternoon hours, with additional clusters of
showers/thunderstorms potentially continuing well into Thursday
night, especially for areas near and north of I-90 where the
greatest forcing from warm advection should occur. Highs
Thursday mainly in the 70s, although some southern areas could
surge into the 80s late in the day depending on the placement of
the warm front, with mainly 60s expected for lows Thursday
night.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
Active weather is anticipated through the duration of the long term
period, with the potential for showers and/or thunderstorms each day.
At the start of the long term period, our region will be situated
within W-SW flow in the low to mid levels, allowing 850 hpa temps
will have warmed up to about 16-18 degrees C. A flat ridge will be
in place over the area, and some subtle disturbances at 500 hpa will
be sliding through the fast flow aloft.
Despite no nearby surface boundaries, daytime heating will allow for
scattered showers and thunderstorms to develop on Friday, especially
across the higher elevations, and then drifting into the valley
areas. While not everywhere will see a shower or t-storm, there is
the chance for a brief one to occur just about everywhere across the
area, with temps rising into the 80s. It will also feel rather
muggy with dewpoints well into the 60s to near 70 F.
While the chance for showers/t-storms may slightly diminish on
Friday night, there will be another good chance to see some showers
and thunderstorms on Saturday, especially for northern areas, as a
pre-frontal trough starts to approach the area from the west. With
the warm and humid airmass in place, will need to watch for some
locally strong to severe t-storms on Saturday afternoon, although
this will ultimately depend on the exact amount of instability and
shear in place. It looks to be another warm and muggy way with highs
well into the 80s once again.
As low pressure passes by to the north across southern Canada, a
cold front will be passing through the area on Sunday. This will
allow for some additional showers and thunderstorms. If the timing
on the latest 12Z GFS is correct, the best chance would be early in
the day, although this is certainly subject to change, as timing
differences can be expected this far out.
Behind the front, somewhat less humid air will start to work into
the area. Still cannot totally rule out a stray shower thanks to a
nearby upper level trough, but most places look dry behind the front
on Monday with temperatures near seasonable levels.
&&
.AVIATION /02Z TUESDAY THROUGH SATURDAY/...
A quick update to the KALB-KGFL TAF`s. For KGFL, an area of
clearing before the next potential round of clouds and showers have
allowed for IFR conditions to quickly evolve. As for the line(s) of
showers, the deeper convective elements appear to be tracking south
of ALB yet we will place a TEMPO group for the next few hours to
account for lightning activity that may evolve.
Otherwise, a couple rounds of showers are possible north of KPOU
through this evening. While VFR conditions should prevail through
the TAF forecast cycle ending 00Z Wednesday, some exceptions could
occur with patchy fog development overnight and shower potential
through the daylight hours Tuesday with mainly lower CIGS.
Winds diminish to less than 6 Kt tonight. Winds become south to
southwest Tuesday morning at less than 10 Kt.
Outlook...
Tuesday Night: Isolated SHRA...TSRA.
Wednesday: Low Operational Impact. Breezy NO SIG WX.
Wednesday Night: No Operational Impact. NO SIG WX.
Thursday: High Operational Impact. Likely SHRA...TSRA.
Thursday Night: High Operational Impact. Likely SHRA...TSRA.
Friday: Moderate Operational Impact. Chance of SHRA...TSRA.
Friday Night: Moderate Operational Impact. Chance of SHRA...TSRA.
Saturday: High Operational Impact. Likely SHRA...TSRA.
&&
.FIRE WEATHER...
An upper level disturbance will move across the region this
evening with mainly isolated to scattered showers and
thunderstorms. An upper level low and a cold front will bring
additional scattered showers and isolated thunderstorms on
Tuesday, with cooler than normal temperatures. High pressure
will build in from the Mid Atlantic Region by Wednesday, but
temperatures will still run slightly below normal for late June.
A warm front approaching from the southwest will bring more
showers and possible thunderstorms for Thursday.
The RH values will recover to 85-100 percent overnight, dropping
to values in Tuesday afternoon will be in the 35 to 60 percent
range.
The winds will from the southwest to west at 5 to 10 mph
tonight. The winds will increase from the southwest to northwest
at 5 to 15 mph Tuesday.
Winds will be stronger, and variable in direction in and near
any thunderstorms.
&&
.HYDROLOGY...
No widespread hydrological problems are anticipated over the
next several days. Scattered showers and isolated to scattered
thunderstorms are expected this evening through Tuesday, mainly
during the afternoon and evening hours, as a series of
disturbances impact the region with an upper low. Basin average
rainfall amounts will generally be a tenth to a quarter of an
inch in some locations.
A brief period of mainly dry weather is expected most of
Wednesday into Wednesday night with ridging from the south. An
active pattern sets up Thursday into the weekend with showers
and thunderstorms possible with increasing humidity levels.
Rainfall amounts will vary based on where any convection
occurs. The most widespread potential rainfall is expected
Thursday and Saturday.
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...KL/Wasula
NEAR TERM...KL/BGM
SHORT TERM...KL
LONG TERM...Frugis
AVIATION...BGM/NAS
FIRE WEATHER...KL/Wasula
HYDROLOGY...KL/Wasula
Area Forecast Discussion
National Weather Service Dodge City KS
614 PM CDT Mon Jun 26 2017
...Updated Aviation...
.SHORT TERM...(This evening through Tuesday)
Issued at 157 PM CDT Mon Jun 26 2017
Early this afternoon, northwest flow aloft was occurring across
western Kansas. There was a jet streak within this flow aloft
extending from South Dakota into northern Missouri, and this
perturbation was pushing southeast. A weak frontal push at the
surface could be identified in the observations at 18z, and GOES-16
visible satellite confirmed growing cumulus field along this
boundary across southwest Nebraska. At 1830z, a small severe storm
had developed in the Holdrege area, which was moving almost due
south. For late today and tonight, will be carrying 20-30 POPs up
along I-70 as this activity is expected to continue to expand a
little bit in coverage where cumulus was forming west of this
initial storm toward Holyoke, CO (and points southwest from there to
the Palmer Divide). There is not the upper support farther west to
warrant a prolonged cluster of severe convection. Numerous runs of
the HRRR so far today show a general lackluster performance of
convection from this region as it moves southeast through the late
afternoon and by evening, dissolve convection all together just
about everywhere by sunset.
Also watching a mesoscale area of surface convergence across far
southwest KS, but again the short-term convective allowing models
(CAMs) just do not suggest much in the way of sustainability of any
convection down in that area. Nevertheless, will maintain some 15-20
POPs across the rest of southwest KS as any little zone of
convergence could initiate a storm that grows into something fairly
strong, if not borderline severe, in the area south of the Arkansas
River. Any longer lived storms up north could produce up to ping
pong or even golfball size hail before weakening.
Going into Tuesday, the flow pattern changes to more of a west-
northwest pattern, but the surface flow pattern will be radically
different as a substantial leeside trough takes shape. The increased
pressure gradient will lead to 20 to 30 mph winds developing by late
morning and continuing into the afternoon. Lee trough convergence
will strengthen, and this will be the area of focus for any late day
convection. This convergence zone will likely extend from far
northeast Colorado down to northeastern New Mexico. The upper flow
pattern favors more aggressive elevated mixed layer
development/capping, so lee trough convection may have a difficult
time becoming sustained the farther south one goes.
.LONG TERM...(Tuesday night through Monday)
Issued at 245 PM CDT Mon Jun 26 2017
Mid to late week looks to be fairly active as far as the large scale
pattern is concerned as it relates to severe weather potential
across the Central Plains. A largely zonal upper tropospheric
pattern will be in place, with the global models showing an 80-90
knot 250mb jet translating east through the pattern late Wednesday
into Thursday. A lead shortwave trough late Tuesday Night will push
a front east and south into northern Kansas by Wednesday. The
aforementioned jet streak moving into Colorado late in the day
Wednesday should favor post-frontal upslope easterly flow into
northeastern Colorado, which will be in the mid tropospheric
baroclinic zone. We would be looking for severe convection to form
back in the upslope area in addition to the front itself which
should stall out somewhere from southwest into north
central/northeast KS. The problem for southwest KS as far as
widespread severe potential goes is the cap. There will most likely
be a sharp southern cutoff to convective activity. Highest POPs
Wednesday will be in the north as a result. The CAPE/Shear
environment would favor supercell storms with good 850-500mb
crossovers. The initial jet streak late Wednesday will push east,
but it will be followed by another perturbation rippling through the
pattern. Mid level temperatures across western KS should be cooler,
and if the front does not push too far south into the warm
temperatures aloft, another severe weather event will likely unfold
across Kansas. The overall CAPE/Shear environment looks identical
to, if not a bit better than Wednesday. These two days look the best
for severe weather in our region (mainly eastern counties) during
this Long Term range. On Friday, there is global model consensus
that the surface front will push down into Oklahoma with the
emphasis for severe storms down in that area. We should see quite a
bit cooler temperatures Friday as a result. Saturday and Sunday are
initially looking potentially wetter as post-frontal moist low level
winds resume in a general west-northwesterly flow pattern aloft.
It`s really too early to tell how the 4th of July will fare at this
point, given the obvious model uncertainty in the D+8 to 10 range.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 535 PM CDT Mon Jun 26 2017
In the short term the biggest uncertainty is the isolated storms
in portions of northwest and north central Kansas along with
southeast Colorado. Latest forecast may have a VCTS around HYS
through 02Z however it looks like GCK and DDC should be storm
free. Looking ahead the winds will start to pick up for all the
airports at around 18Z tomorrow with around 20 kts sustained out
of the south and gusts up to 30 kts.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 63 89 70 94 / 20 10 10 10
GCK 62 92 68 94 / 20 10 10 10
EHA 62 91 67 95 / 20 10 20 10
LBL 64 91 69 97 / 20 10 10 10
HYS 61 88 70 93 / 30 10 20 10
P28 64 89 71 96 / 20 10 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Umscheid
LONG TERM...Umscheid
AVIATION...Tatro
Area Forecast Discussion
National Weather Service Lincoln IL
904 PM CDT Mon Jun 26 2017
.UPDATE...
Issued at 900 PM CDT Mon Jun 26 2017
A brief re-intensification has occurred along a couple of outflow
boundaries from earlier today, with some thunder development.
Coverage should remain isolated in general, but have extended the
mention of thunder for the next few hours of the evening, mainly
for our southwest counties south of a line from Lincoln to
Rushville. The HRRR and RAP output show showers lingering until
midnight, but remaining weak and isolated. Have kept the PoPs in
the slight chance to low chance categories the rest of the
evening, and went dry after midnight.
Patchy fog, some locally dense, is the other concern later
tonight under light winds and generally clear skies. Boundary
layer moisture appears sufficient for fog development based on
our lowest dewpoints during peak heating this afternoon along with
forecast low temps. Will add some patchy fog to the forecast,
especially where HRRR shows some dense fog from Bloomington to
Lincoln in the central part of our forecast area.
Lows look on track for the low to mid 50s, but we can`t rule out a
few upper 40s in traditional colder spots.
Tomorrow looks to be a pleasant day, with sunny skies, light
westerly winds, and slightly warmer high temps in the mid to upper
70s.
Updated forecast info will be available shortly.
&&
.SHORT TERM...(This evening through Tuesday)
ISSUED AT 315 PM CDT Mon Jun 26 2017
A weak front will continue to move south through the CWA this
evening. The clearing that has occurred has allowed some heating
and instability to occur/develop over parts of the area. Isolated
to scattered showers and storms will remain possible late this
afternoon through early this evening. The precip should wane
around sunset leaving the remainder of the evening dry with skies
becoming clear. Dry weather is expected then to build into the
area late tonight and into tomorrow as high pressure builds into
the region.
Temps will remain on the cool side tonight and through tomorrow.
.LONG TERM...(Tuesday night through Monday)
ISSUED AT 315 PM CDT Mon Jun 26 2017
High pressure will continue to dominate the weather across the
area Tue night as the pattern becomes more zonal. Then another
weather system will quickly move into the area beginning Wed. As
the front moves through the CWA it will become parallel with the
flow by Thur and then sit somewhere over the area through the rest
of the week. Models appear to be in fairly good agreement with the
front draped across central IL through this period, which means
showers and storms will remain possible. Models also look similar
with timing of individual waves moving along the front so
consensus forecast of likely pops somewhere in central IL Wed
night through Fri looks like a good forecast at the moment. Into
the weekend the front should get pushed out of the area to the
southeast. However, additional chances of precip will return for
later part of the weekend and into the beginning of next week as
the pattern returns to a somewhat northwest flow with a upper
level trough over the Great Lakes region.
Temps will also get warmer again ahead of the next system and then
remain that way through the week, evening with precip/clouds and
the front somewhere across the area.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 649 PM CDT Mon Jun 26 2017
A line of showers will continue to drift south through central
Illinois early this evening. There has been a steady weakening
trend in the convection, and little to no additional lightning is
expected during the first couple hours of the 00z TAF period. Have
not included any thunder as a result, with just VCSH primarily as
the diminishing showers linger through 02z.
VFR conditions will prevail over the next 24 hours, with the
lowest ceilings during any showers early this evening at or above
4K ft.
High pressure will provide quiet aviation weather the remainder of
the TAF period, with light and variable winds overnight and light
westerly winds tomorrow.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Shimon
SHORT TERM...Auten
LONG TERM...Auten
AVIATION...Shimon
AREA FORECAST DISCUSSION...UPDATED
National Weather Service Jackson KY
1045 PM EDT Mon Jun 26 2017
.UPDATE...
Issued at 1045 PM EDT MON JUN 26 2017
Thicker clouds are slowly advancing from the northwest, with a
few showers popping up near and north of the Ohio River. The
latest HRRR has been showing more lighter returns making it into
our area compared to some of the previous runs. As such, will
maintain the slight to low chance POPs through the rest of the
night. Did increase temperatures a bit in places, where thicker
clouds are combatting the drier low level air. Updates have been
sent.
UPDATE Issued at 733 PM EDT MON JUN 26 2017
Freshened up the hourly temperatures and dew points through this
evening. Thicker cloud cover moving in from the northwest should
hold off long enough for a quick drop in the valleys through 06z,
otherwise the forecast remains on track.
&&
.SHORT TERM...(This evening through Tuesday night)
Issued at 328 PM EDT MON JUN 26 2017
Another cool and dry summer afternoon remains in place across
eastern Kentucky, with temperatures in the low-mid 70s and dewpoints
comfortably sitting in the mid 40s-mid 50s. One band of mid-high
clouds continues to move across southern to central Kentucky,
while another subtle shortwave impulse is producing a second
batch of these from the Midwest through the Ohio Valley. This
latter wave, stretching from the Great Lakes to near St. Louis,
will bring isolated to scattered showers through the Ohio Valley
and into eastern Kentucky later this evening through tonight.
Moisture will be very limited and confined to top-down moistening,
as surface ridging moves south into the Tennessee Valley.
Therefore, expecting rainfall amounts to remain below one tenth of
an inch.
Rain chances will continue into Tuesday afternoon as the axis of the
mid level trough swings through eastern Kentucky. Given steepening
lapse rates owing to lower heights with the base of the trough
overhead, isolated thunder chances will be in the offing until a
weak cool front pushes through by mid-late afternoon and shuts off
any additional chances for precipitation. This potential for thunder
will be rather limited as temperatures only warm into the mid 70s
with dewpoints in the mid 50s.
One more cool summer night will be in store Tuesday night into
Wednesday morning as a ~1020 mb surface ridge slides across the
Bluegrass. Temperatures will drop into the mid 50s on ridges and
upper 40s to lower 50s in valleys, allowing for some areas of valley
fog.
.LONG TERM...(Wednesday through Monday)
Issued at 3 PM EDT MON JUN 26 2017
There is good model agreement with the overall upper air pattern
through the forecast period. The long wave trough over the eastern
U.S. at the beginning of the period will be lifting out with more
zonal flow becoming established across our area. A couple of short
wave troughs will move through the mean flow during latter part of
the week, with the most significant short wave moving across the
Great Lakes this weekend.
At the surface, high pressure will be moving off to our east on
Wednesday. As a result temperatures will begin to warm and with
return flow developing moisture will also be on the increase across
the area through the latter part of the week. Wednesday will still
have dewpoints in the 50s, but after that dewpoints will go back
into the 60s, with mid and upper 60 dewpoints expected for the
remainder of the forecast period. By Thursday afternoon a short wave
passing by to our north may result in a few storms in the northern
part of the area while moisture returning from the south will bring
a slight chance of storms to the south. With a slow moving front to
our north at the end of the week, and moisture continuing to
increase, the storm threat will expand on Friday. However storm
chances on Friday will remain relatively low. The best chance for
showers and storms will occur on Saturday into Saturday night as a
more significant short wave and associated surface low moving across
the Great Lakes results in a southward push of the cold front. The
front will stall in the OH valley and this will keep a chance of
showers and thunderstorms in the forecast into next week.
Temperatures will warm back into the mid 80s on Thursday, but the
daily threat of showers and storms will keep maximums in the lower
80s for most days from the weekend into early next week. With the
increase in dewpoints after Wednesday we`ll see our typical summer
lows of muggy 60s from the end of the week into next week.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
ISSUED AT 733 PM EDT MON JUN 26 2017
VFR conditions look to hold on through the period. Clouds will
thicken and lower to around 6k feet agl from northwest to
southeast tonight, as a weak cold front approaches. A few showers
will threaten from late tonight into Tuesday morning, before
chances diminish into the afternoon as the cold front exits. Light
and variable winds will turn more out of the northwest at around
5 kts once again into Tuesday.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GEOGERIAN
SHORT TERM...GUSEMAN
LONG TERM...SBH
AVIATION...GEOGERIAN
Area Forecast Discussion
National Weather Service Lake Charles LA
1020 PM CDT Mon Jun 26 2017
.DISCUSSION...
Regional 88Ds show the bulk of the precipitation which developed
earlier today has moved off into the Gulf with just a few showers
now noted along the coast over swrn LA. Water vapor imagery shows
drier air moving into the region from the north which is
corroborated by regional 00z soundings as much lower PWAT/mean RH
values are noted to our north. All of this spells a trend in
overnight POPs of slim/none across most of the nrn half to small
chances closer to the coast...to much higher over the coastal
waters. As expected, this also agrees with latest short-term
high-res runs as well.
Elsewhere, just minor tweaks at most per latest obs/trends. Update
out shortly.
25
&&
.PREV DISCUSSION... /issued 659 PM CDT Mon Jun 26 2017/
DISCUSSION...
For 00z TAF issuance.
AVIATION...
Local 88Ds continue to show quite a bit of convection covering the
srn 1/2 of the forecast area, possibly impacting the srn
terminals...however as this activity is diurnal in nature, expect
it to diminish over the next few hours with loss of heating.
Forecast time-height sections not indicating much boundary layer
moisture through the overnight hours so not expecting any fog at
this time. Tomorrow appears to be a repeat of today with good
moisture closer to the coast along with a weak shortwave or
weakness aloft and daytime heating.
25
PREV DISCUSSION... /issued 326 PM CDT Mon Jun 26 2017/
DISCUSSION...
Weather map showing weakening frontal boundary across SE TX/S LA
this afternoon, likely along the I-10 corridor. Showers and
thunderstorms have increased in coverage over the last couple of
hours across SE TX/SW LA, with scattered coverage over the coastal
waters. This was expected with continued consistence from the
HRRR guidance this morning and afternoon. The convection expected
to continue through sunset and diminish this evening after the
loss of daytime heating.
The front is expected to slowly dissipate with a predominate
southeast flow resuming across the region by Tuesday, bringing
with it increased Gulf moisture and higher chances of showers and
thunderstorms. The best chances for showers and thunderstorms
expected Wednesday through Friday as a weak shortwave aloft
enhances lift within our region already saturated with moisture
moving in from the Gulf.
By Friday evening into the weekend, high pressure with slightly
drier air aloft is expected to diminish shower and thunderstorm
chances to near ~20% for the weekend.
DML
MARINE...
High pressure settling east of the area will provide a more
predominate east to southeast flow, with winds and seas
increasing by the end of the week. This will bring increased Gulf
moisture for increased chances of showers and thunderstorms
through Friday. By Friday afternoon into the weekend, high
pressure and drier air aloft is expected to limit shower and
thunderstorm activity.
DML
&&
.PRELIMINARY POINT TEMPS/POPS...
AEX 68 89 70 90 / 10 40 20 50
LCH 73 88 73 87 / 30 50 30 50
LFT 71 87 72 87 / 20 50 20 50
BPT 73 87 74 87 / 30 50 30 50
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...None.
TX...None.
GM...None.
&&
$$
Area Forecast Discussion...UPDATED
National Weather Service New Orleans LA
1016 PM CDT Mon Jun 26 2017
.UPDATE...
Brought PoPs and weather grids in line with current trends along
the immediate coast and near shore waters. Went with RUC13 model
hourly PoPs which does show 90% or better where activity is
currently, then a tight gradient to near 0% closer to the New
Orleans metro area. There is some indication of potential
convection forming overnight over Lake Pontchartrain which is
plausible in this environment. This update mainly affects the
web-based areal point-n-click forecasts, which may or may not be
fully functional at this time. Major point forecast locations are
unaffected aside from perhaps the Houma-Thibodaux area. Will not
send a ZFP as the gradient across the lower parishes will grab the
higher values and would be unrepresentative for some areas such as
Upper Jefferson and the adjacent River Parishes. 24/RR
.AVIATION...
Most terminals should remain VFR despite large anvil blow-off from
ongoing convection along the LA coast. KHUM has not reported an
observation since 26/2347Z, and possibly may be transmitting with
an incorrect date. Therefore will show NO AMDT SKED with the 06Z
TAF issuance. 24/RR
&&
.PREV DISCUSSION... /issued 738 PM CDT Mon Jun 26 2017/
SOUNDING DISCUSSION...
The 00z sounding shows a dry and very stable airmass in place.
Precipitable water values have continued to decline on the back of
a persistent north-northeast flow in the low to mid-levels of the
atmosphere. PW values dropped a quarter inch since the 12z
sounding, and the mean mixing ratio fell from 13.2 to 11.2g/kg.
This drying of the mid-level atmosphere has resulting in warmer
temperatures between 850 and 700mb, and that warming has reduced
overall instability. This is most evident by the very weak 5.6C/km
lapse rate observed in the 850-500mb layer, lack of CAPE, and very
high convective temperature of 100F. 32
&&
.PRELIMINARY POINT TEMPS/POPS...
MCB 68 88 69 87 / 0 0 0 50
BTR 70 88 71 87 / 0 0 10 60
ASD 69 89 72 86 / 20 0 0 60
MSY 73 86 74 84 / 20 20 10 60
GPT 71 86 73 85 / 20 10 0 50
PQL 68 89 71 87 / 10 10 0 30
&&
.LIX WATCHES/WARNINGS/ADVISORIES...
LA...None.
GM...None.
MS...None.
GM...None.
&&
$$
Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
658 PM CDT Mon Jun 26 2017
.SHORT TERM...
203 PM CDT
Through Tuesday...
Showers and a few thunderstorms have increased across the I-80
corridor and southward ahead of a surface trough/cold front.
MLCAPE per RAP mesoanalysis is about 250 J/kg, thus the widely
scattered shower but generally isolated and brief thunder. This
activity will continue to slide southeast along and ahead of the
trough axis. A few showers are possible farther north, but the cu
field here is flatter and we need to await the upper low in WI for
a little better forcing later this afternoon. Instability is
weaker near this low, and with the later arrival expect some
isolated showers in far northeast IL late this afternoon.
Compact upper low will quickly dig southeast of the
area this evening, ending our lower precip chances fairly quickly
in its wake. Surface high pressure will slide just to the
southwest of the area tonight. With clearing skies in subsidence
behind this wave, it will be another fairly chilly night with lows
again in the upper 40s to mid 50s. We maintain a weak pressure
gradient over the area which will keep things from getting too
cool and limit any fog.
The surface high will move from central Illinois east through the
Ohio valley on Tuesday, while low pressure will develop across the
high plains. With lower level winds shifting southwesterly in this
pattern and plentiful sunshine, expect a nice rebound in
temperatures back to near 80. A lake breeze may also form, but at
this point it appears to remain confined to the near lakeshore
areas.
KMD
&&
.LONG TERM...
233 PM CDT
Tuesday night through Monday...
A busier pattern sets up with multiple chances of showers and storms
Wednesday through Friday, and then again early next week.
Surface high pressure shifts east Tuesday night, and a surface low
develops over the northern plains. The NAM and ECMWF still
suggest a dying convective line/MCS may move into northern IL
Wednesday morning while other models keep the convection over WI.
Continued with a dry forecast Wednesday morning, but if a
convective line or cloud shield move over the area, they could
limit storm development in the afternoon. Showers and storms are
expected ahead of the low Wednesday afternoon. The low`s warm
front lifts through the region leading to highs in the low 80s.
Expecting lift from an upper level shortwave, but forecast
soundings feature very little CAPE. CAPE increases to around 500
J/kg by 00Z Thursday/7PM Friday. Shear on the other hand is strong
at around 50 kt. Low level shear in particular looks strong and
LCL`s are low. CAPE values are much higher over Iowa so thinking
while we will see scattered thunderstorm development, the majority
of severe storms will occur over Iowa. Thinking storms to the
west will become linear and move through Wednesday evening/night.
The other issue for Wednesday will be wind gusts. As the previous
discussion mentioned, the potential exists for wind gusts to reach
or exceed 35 MPH. However, unsure at how well we will mix due to
cloud cover.
The low continues over the northern Great Lakes Thursday, and its
cold front stalls over north central IL. Heat and humidity build
with highs in the mid 80s Thursday. Showers and storms are expected
south of the boundary roughly south of I-88. Forecasted CAPE values
vary from 1000-2000 J/kg, but shear values are much lower around 20
kt.
Zonal flow aloft allows additional upper level disturbances to shift
east overhead through Friday. In addition, a surface low is
forecast to form over Iowa/Missouri Friday morning and shift
northeast over the forecast area Friday.
Cooler air aloft arrives Saturday and it looks like precip will stay
to the north and east. High pressure moves over the region Saturday
night and Sunday. Guidance on how the next upper level system will
evolve early next week with the GFS featuring a stronger system than
the ECMWF. Therefore left PoPs as is.
JEE
&&
.AVIATION...
For the 00Z TAFs...
Latest radar imagery showing a continued diminishing trend of the
scattered showers and isolated thunderstorms just to the south of
the terminals. Don`t anticipate any further development near or
around the terminals tonight or through the remainder of the
forecast period. Several outflow boundaries do remain around the
terminals though, but do anticipate winds to stay in the north
northwest direction for this evening. The exception is GYY, where
winds have turned to the northeast. This direction will likely
remain through mid/late this evening. VFR conditions will continue
through the period, while winds gradually shift more west and then
southwest tonight into Tuesday morning.
Rodriguez
&&
.MARINE...
233 PM CDT
Northwest winds have increased to 20-25 kt across the nearshore
waters. Winds will become even more northwest as a cold front moves
through this evening. Winds diminish to where a small craft advisory
will not be needed for the IL shore early this evening. However,
waves in the Indiana nearshore waters will remain hazardous past
midnight and slowly subside overnight.
West winds become southerly Tuesday as the high pressure ridge moves
over the lake. The next low forms over the northern plains Tuesday.
The pressure gradient tightens over the lake Wednesday between the
high over the central Atlantic Coast and the low over the northern
plains. South winds may increase to gales Wednesday. The low weakens
Thursday as it shifts east, and winds weaken and become west to
northwest.
Another, weaker low may move over the southern end of the lake
Friday afternoon/evening. West winds are expected behind the low
through Sunday.
JEE
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...None.
IN...Beach Hazards Statement...INZ001-INZ002 until 4 AM Tuesday.
LM...Small Craft Advisory...IL nearshore waters until 7 PM Monday.
Small Craft Advisory...IN nearshore waters until 4 AM Tuesday.
&&
$$
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Area Forecast Discussion...UPDATED
National Weather Service Miami FL
1100 PM EDT Mon Jun 26 2017
.UPDATE...
As of 1100 PM EDT...Quick late evening update to bump up PoPs
across the Gulf Coast to account for cluster of thunderstorms that
have developed over coastal Collier County, along with another
area of storms over Lake Okeechobee. These storms have likely
formed in response to convergence along outflow boundaries from
earlier afternoon storms. This activity should continue for the
next few hours, with frequent lightning and locally heavy rainfall
the primary threats, and will continue to monitor potential
flooding concerns in vulnerable areas in and around the Naples
metro. Elsewhere across the region, mainly dry conditions persist,
with a few isolated showers over the Atlantic waters.
For the rest of tonight, the Gulf convection should begin to
slowly wane and dissipate over the next few hours, similar to
activity near Lake Okeechobee. A light land breeze is still
expected to develop off the east coast, helping to focus
additional isolated to scattered showers and storms through the
remainder of the night, mainly over the Atlantic waters. Low
temperatures will generally be in the 70s.
&&
.PREV DISCUSSION... /issued 803 PM EDT Mon Jun 26 2017/
AVIATION... Isolated showers with a couple rumbles of thunder
will continue to dwindle over the interior during the next few
hours, leaving behind scattered low clouds with bases around 3000
ft msl. Wind will decrease to light and variable overnight. Aft
around 27/1300Z, south east winds will again increase to near 10
KT. VCSH conds should begin to develop aft 27/1700Z or 18Z.
Convection will occur closer to the east coast TAF sites on
Tuesday afternoon, but still mainly concentrated in the interior.
PREV DISCUSSION... /issued 715 PM EDT Mon Jun 26 2017/
UPDATE...Convection this afternoon has been a little sparser
than expected despite the numerous boundary collisions. Current
forecast updates are mainly to cut back rain chances into this
evening, with ongoing boundaries keeping at least isolated
convection going through late evening. Latest RAP analysis shows
very light NE steering flow (less than 5kts), but this may be
enough that new activity that gets going along collisions will
trend towards the west side of the interior.
Land convection dies by late evening with mesoscale models
showing the overnight landbreeze leading to the development of
showers and storms over the water late tonight. It remains warm
and muggy, otherwise known as South Florida in late June, with
lows in the 70s.
PREV DISCUSSION... /issued 411 PM EDT Mon Jun 26 2017/
DISCUSSION...
THIS AFTERNOON AND TONIGHT: Frontal boundary is draped across the
north Central peninsula this afternoon, pushing the ridge axis
further south into our region. With the axis overhead steering
flow is very light, with a little more southerly component than
the past few days. Scattered showers and storms are ongoing along
both seabreezes as they move inland this afternoon. Boundary
collisions, along with the collision of the seabreezes will
continue to drive development into the evening hours. Given the
light flow, storm movement will be minimal with heavy rain, gusty
winds, and lightning the main concerns. While most activity will
remain over the interior, outflow boundaries may drive a few
storms into either coast.
Convection dies late tonight with mesoscale models hinting at
landbreeze development leading to the development of showers and
storms over the water and adjacent land areas overnight.
TUESDAY AND WEDNESDAY: Upper level trough moving across the eastern
US erodes the northern side of the western Atlantic ridge through
midweek. Low level front currently across North/Central Florida will
slowly drop south through mid week, but as is usually the case this
time of year, washes out before it reaches Lake Okeechobee.
Prevailing flow will become more southwesterly, though fairly light
at 10kts or less, with a modest increase in mid level moisture and
slightly cooler temperatures aloft. All of the above will lead to a
higher coverage of showers and storms as we head into mid week. We
should see both seabreezes developing and moving inland, with the
best coverage during the late afternoons and evenings over the
interior with the seabreeze collision.
THURSDAY THROUGH UPCOMING WEEKEND: Remnant frontal boundary across
the FL peninsula washes out into late week across the state. Upper
level trough will exit the northeastern US as the upper level
extent of the Western Atlantic ridge rebuilds across Florida. The
surface ridge behind the front across the Mid Atlantic will move
offshore and reinforce the western Atlantic ridge, bringing a
return of prevailing deep easterly flow. This drier, more
subsident pattern will allow rain chances to drop closer to
seasonal norms for this time of year with afternoon convection
favoring interior and Gulf coast areas as the east coast
seabreezes moves inland faster.
MARINE...Frontal boundary across North/Central Florida will weaken
the western Atlantic high, leaving light easterly flow in place
through midweek. Both the Gulf and Atlantic seabreezes will develop
and move inland each afternoon, bringing winds up to around 10kts
near the coast. Best coverage of showers and thunderstorms will
generally be inland, however outflow boundaries could enhance some
convection over the waters. High pressure rebuilds to the north late
week with east-southeast winds returning around 10-15kts into the
upcoming weekend.
&&
.PRELIMINARY POINT TEMPS/POPS...
West Palm Beach 77 91 75 90 / 20 50 30 50
Fort Lauderdale 79 90 78 91 / 20 40 40 50
Miami 78 91 78 92 / 20 50 40 60
Naples 76 89 76 91 / 40 30 20 50
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...None.
AM...None.
GM...None.
&&
UPDATE...92/IRL
DISCUSSION...88/ALM
MARINE...88/ALM
AVIATION...27/JT
Area Forecast Discussion
National Weather Service New York NY
1055 PM EDT Mon Jun 26 2017
.SYNOPSIS...
Weak high pressure builds farther offshore tonight as a cold
front approaches from the Great Lakes. The front moves through
the area Tuesday evening. High pressure will then briefly follow
for the middle of the week. Another frontal system approaches
for the end of the week.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
A weak surface trough was across the region from the Hudson
Valley into eastern Pennsylvania and into north central
Maryland. This was the focus of a few light showers, along with
a shortwave rotating through an upper trough. Put
probabilities, slight chance, into the forecast for areas across
the far western zones initially and then slowly east through
the overnight. The HRRR was also supporting the chance of
showers overnight, just a couple of hours too quick. Lower
levels are dry and any precipitation reaching the ground is
expected to be light.
Anomalously strong upper trough across the Great Lakes and Ohio
Valley states pivots eastward the next couple of days with
gradual height falls and increasing daytime instability.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/...
Airmass gradually destabilizes on Tuesday with height falls and
approaching cold front over the Great Lakes. However, dry low-
levels and lack of strong surface trigger will be limiting
factors for the development of showers/thunderstorms. The best
chance will be across the interior during the afternoon hours.
Wind shear is also weak, limiting any organization.
Cold front works across the area in Tuesday evening with high
pressure to follow.
Daytime highs will once again be near or just below seasonable
levels.
There is a moderate risk for the development of rip currents
Tuesday.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
High pressure will be in control Wednesday through Thursday night,
bringing dry conditions and near normal temperatures across the
area. As high pressure moves offshore, warmer temperatures and
increasing chances of showers and thunderstorms will develop Friday
through Sunday. High pressure builds back on Monday, bringing more
seasonable temperatures and dry conditions across the area.
&&
.AVIATION /03Z TUESDAY THROUGH SATURDAY/...
A weak trough of low pressure over the area will move east late
tonight...followed by another one on Tuesday.
VFR through the TAF period.
An area of showers over SE PA may impact KSWF between 05z and
06z. Latest hi res guidance weakens this activity as it tracks
NE next few hours...so will watch and amend as needed. Also a
few showers have popped up in northern MD, but is not as much
widespread as some of the earlier guidance was indicating. Thus,
have decided to hold off on adding showers to other terminals
for now.
S-SW winds 5-10kt will become light and vrb outside of NYC
terminals overnight. Winds will increase 10-15kt Tue aftn with
gusts in the upper teens to lower 20s...becoming W-NW around 00z
as the trough pushes through.
Could be some isold showers/tstms Tue aftn associated with upper
disturbance and sfc trough moving through.
.OUTLOOK FOR 00Z WEDNESDAY THROUGH SATURDAY...
.Tuesday Night-Wednesday...VFR.
.Thursday...VFR. Chance of a late day shower/thunderstorm.
.Friday and Saturday...Sub-VFR in showers and thunderstorms.
&&
.MARINE...
Winds and seas forecast on track.
With an overall weak pressure gradient remaining across the
region, winds and seas are expected to remain below small craft
advisory criteria (25kt winds, 5 ft seas) through Tuesday.
Below small craft advisory conditions expected Wednesday as High
pressure moves south across the area waters. Winds and seas
increase, and small craft advisory conditions are possible later
Thursday and into Saturday.
&&
.HYDROLOGY...
No hydrologic impacts expected through the beginning of next
week.
&&
.TIDES/COASTAL FLOODING...
Astronomical tides are still running high with a low chance of
any minor coastal flooding across the south shore back bays of
Nassau county with this evening high tide cycle, approximately
between 10pm and 12am. The water levels would only be expected
to touch the minor benchmarks few just a couple of gages so no
statement has been issued.
&&
.EQUIPMENT...
Observations from KFRG (Farmingdale, NY) are not available.
Observations from KHPN (White Plains NY) and KHVN (New Haven CT)
are being disseminated through backup methods. All is due to
an FAA communication line outage. Return to service time is
unknown.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...None.
&&
$$
SYNOPSIS...Fig/DW
NEAR TERM...MET/DW
SHORT TERM...DW
LONG TERM...Fig
AVIATION...
MARINE...Fig/MET/DW
HYDROLOGY...Fig/DW
TIDES/COASTAL FLOODING...
EQUIPMENT...
Area Forecast Discussion
National Weather Service Pittsburgh PA
932 PM EDT Mon Jun 26 2017
.SYNOPSIS...
Upper low pressure will maintain cooler temperature and a periodic
shower chance for the first half of the week.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
A vigorous shortwave trough will approach tonight bringing
another round of scattered showers. Showers will push east late
this evening and dissipate upon arrival due to unfavorable
timing in a stabilizing atmosphere. CONSShort (with a higher RAP
weight) was utilized heavily for construction of overnight
PoPs. While some elevated instability does remain overnight,
will keep thunder out of the forecast as it should be very
isolated.
Overnight lows will again will run 10 degrees below normal.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/...
Cold troughing will keep isolated showers in play through the
morning but will diminish by the afternoon with the upper
trough axis to the east. Temperatures will again be well below
normal but by Wednesday temperatures will begin to moderate as
flow aloft flattens/ridges in response to a trough digging
across Western Canada. Warmth and humidity are forecast to
enhance via southerly boundary layer flow as that trough
progresses over the Northern Plains/Upper Midwest, and precip
chances escalate as ejected energy slides over the Lakes and
spawns convection by Thursday.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
The aforementioned trough/associated cold front is projected across
the Great Lakes and Upper Ohio Regions next weekend. Precip is
thus likely but temperature in the wake of the system is
expected to remain near the seasonal averages given the lack of
amplitude in the progged flow pattern.
&&
.AVIATION /02Z TUESDAY THROUGH SATURDAY/...
Will continue with prevailing VFR through most of the night
across the region, as any showers with the overnight shortwave
passage should be fairly brief overall. Have handled with VCSH
for now. Do have a TEMPO mention for thunder at FKL/DUJ early on
with lingering convection, but overnight activity should be more
scattered and weaker overall. Towards sunrise, MVFR ceilings are
still expected north of PIT, with lesser chances of such to the
south. These ceilings will lift with mixing later in the
morning. Isolated showers will remain possible through much of
Tuesday, before a clearing trend takes hold by sunset.
.OUTLOOK...
Next chance for widespread restrictions comes with the approach
of frontal boundary at the end of the week.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...None.
OH...None.
PA...None.
WV...None.
&&
$$
Area Forecast Discussion
National Weather Service Pocatello ID
220 PM MDT Mon Jun 26 2017
.SHORT TERM...Tonight through Wednesday. Upper trough pushing over
forecast area. Moisture working northeast toward the region.
Favorable upper jet dynamics and instability in favor for
development of convection starting this afternoon, shifting east
ahead of surface cold front. HRRR still showing gusts near severe
limits this evening as line of storms works northeast from south
of BYI through the Snake Plain. DCAPE values support stronger
convective gusts as well. PW values at or above 0.75 where
convection expected to develop/move so wetting rains likely out of
the storms. Initial shortwave shifts east through the night, and
models all still paint weak convection lingering across the region
past sundown, mainly higher elevation areas. Have kept precip
going overnight. Second shortwave shifts across the region
Tuesday, and could see another round of strong storms particularly
in NE quadrant of fcst area. Breezier through the day as sfc
gradient tightens behind tonight`s front. Upper trough axis slowly
sags SE, with one more shortwave associated with base of trough
passing through on Wednesday. Yes, one more round of convection,
expected to be weaker, and mainly concentrated in areas along the
WY border. DMH
.LONG TERM...Wednesday night through Monday. Upper trough pushes
into the Plains in the latter portions of the week, with northwest
flow over ID and dry conditions. Next Pacific trough slips inland
Saturday, and both GFS/ECMWF settling on increased chances for
convection across the area. Have nudged PoP upward slightly for
Saturday. This trough is fairly progressive, so models project
another return to dry northwest flow Sunday and Monday. DMH
&&
.AVIATION...Thunderstorms are expected to develop and move southwest
to northeast across the area late this afternoon and tonight as an
upper-level trough and attendant cold front slide across the area.
Best thunderstorm chances through this evening appear to be at KBYI
and KSUN...with lesser coverage expected near KPIH...KIDA...and
KDIJ. Better chances will eventually shift east to KDIJ late tonight
and tomorrow. Strong gusty winds will be possible with the
storms...along with brief MVFR or lower conditions. Outside of any
showers/storms...VFR conditions are anticipated. West/southwest
winds will increase Tuesday morning behind the front with strongest
winds expected at KPIH/KIDA/KBYI.
KB
&&
.FIRE WEATHER...Showers and thunderstorms will continue to develop
this afternoon and evening ahead of an upper-level trough and cold
front...and make their way southwest to northeast across the area
late this afternoon through tonight. Some of the thunderstorms this
afternoon and evening may produce strong gusty winds and little
rainfall. The Central Mountains and South Central Highlands are
favored to see the greater thunderstorm coverage through this
evening. Better chances will become focused over the Central
Mountains and Upper Snake Highlands late tonight...with the Upper
Snake Highlands seeing the higher chances on Tuesday. Behind the
cold front passage tonight...west/southwest winds will increase on
Tuesday with the strongest winds expected in the Snake Plain and
Eastern Magic Valley where gusts to around 35 mph will be common.
Temperatures on Tuesday will cool 10-15 degrees from today in wake
of the front...resulting in higher RH values (minimum RH values 20
percent or higher). Thus no critical fire weather conditions are
anticipated despite the gusty winds. For the remainder of the
week...near normal temperatures can be expected along with mainly
dry conditions aside from some lingering showers and storms in the
Upper Snake Highlands on Wednesday.
KB
&&
.PIH WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$