Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 06/18/19
AREA FORECAST DISCUSSION
National Weather Service Albany NY
1027 PM EDT Mon Jun 17 2019
.SYNOPSIS...
Seasonably dry weather in on tap today as weak high pressure
builds into the region. Disturbances moving along a stalled
frontal boundary south of the region will bring renewed chances
of showers tonight through the day Wednesday, with best chances
south of the Capital Region.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
As of 1020 PM EDT, regional radars remain quiet, and thus no
precipitation is expected through at least midnight regionwide,
if not until after 2 AM. Still some thin spots in the clouds
persist across northern areas, where temps have already dipped
into the lower/mid 50s in a few areas. Clouds are thicker across
southern areas, where temps remain elevated, generally in the
lower/mid 60s. A light south wind has also kept temps elevated
within the Hudson River Valley from Albany south, with mid/upper
60s.
As mid/upper level winds continue backing overnight, moisture
across PA, along with showers across western PA and OH should
continue expanding north and east. Latest RAP13 and HRRR suggest
some showers may reach the I-84 corridor into NW CT after
08Z/Tue, so have backed off on PoPs in most southern areas,
increasing to slight chance to low chance between 08Z-12Z/Tue.
Better chances for showers, and northward expansion, is expected
after 12Z/Tue.
Have lowered temps slightly across northern areas where they
have locally dipped into the lower 50s. Expect mins in the
mid/upper 40s in some portions of the SW Adirondacks, with
lower/mid 50s in many northern areas, and even some portions of
the southern Greens and northern Berkshires overnight.
Elsewhere, clouds and higher moisture levels should keep temps
mainly in the upper 50s to lower 60s.
Some patchy fog may form overnight, especially across some
northern sheltered valley areas.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/...
Showers are expected to continue in southern areas through the
morning and some isolated to scattered showers could build as
far north as the Mohawk Valley and southern VT before everything
exits during the afternoon. Outside of the showers there should
be some thin spots and breaks in the cloud cover allowing
temperatures to rise somewhat through the day. Highs Tuesday in
the 70s with around 70 to lower 70s in higher terrain and
southern areas where the best coverage of clouds and showers
will be.
There is a general consensus for a dry period Tuesday night into
Wednesday morning but there are some uncertainties as to where
the northern edge of the cloud cover and diffuse low level
forcing and low level dew point gradient sets up. There could be
some lingering isolated showers and persistent cloud cover over
parts if not much of our region Tuesday night into Wednesday but
again, there is really no well defined upper system and very
weak and diffuse low level forcing. There could be some
scattered showers and isolated thunderstorms Wednesday afternoon
due to daytime heating and temperatures reaching convective
temperatures in a slowly increasingly humid airmass. Highs
Wednesday in the 70s to around 80.
There is an increasing consensus that a well organized upper
system that is currently in the SW U.S. will track across the
central U.S. and affect our region Thursday into Thursday night.
There is quite a spread in sources of guidance/ensembles as to
the timing and whether part of the warm sector and enhanced
instability can build north into our region. There are some
signals that the eastern Catskills, mid Hudson Valley and NW CT
could see some strong thunderstorms Thursday afternoon
depending again, on how far north steeper midlevel lapse rates,
low level jet energy and the gradient of the thermal/moisture
boundary associated with the cold front. It is just worth
keeping an eye on severe weather potential and localized heavy
potential for Thursday afternoon and night. The strong
thunderstorms could miss our region to the south as indicated in
some sources of guidance. Indicating showers and thunderstorms
increasing in coverage through Thursday afternoon. Highs in the
70s but around 70 higher terrain.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
Medium-range NWP is depicting an anomalously strong low pressure
system tracking from the vicinity of PA to off the southern New
England coast Thursday night ahead of a strong and progressive
midlevel trough. Still some uncertainty with the track of this
system, but current consensus puts us on the cold side of the low,
such that deformation precip looks like a good possibility. Despite
lingering uncertainty in storm track, likely to categorical PoPs are
warranted. Left thunder out of the forecast assuming this southerly
track.
Height rises in the wake of this trough quickly build in, resulting
in a drying trend Friday into Saturday. Temps may come up a little
short of normal Friday with some cold advection and perhaps some
lingering morning clouds and showers, but temps return closer to
normal by Saturday. Will keep the forecast dry Sunday with
temperatures continuing near normal, but entry level shower chances
return for Monday as indications are the the midlevel flow goes more
zonal, reducing the subsidence. There is uncertainty as to how fast
this occurs, such that confidence in a completely dry weekend is not
extraordinarily high at this point, but it looks more likely than
not to be mainly dry.
&&
.AVIATION /02Z TUESDAY THROUGH SATURDAY/...
A frontal system will remain south of the TAF sites through
Tuesday. A weak wave of low pressure will track along this front
during Tuesday, bringing clouds and some showers, especially to
southern TAF sites (KPOU and KPSF).
Best chances for showers appear to be after 10Z/Tue, again
focusing at KPOU and KPSF. Showers may linger until 16Z-18Z/Tue
before tapering off. MVFR Cigs and VFR/MVFR Vsbys will be
possible as any showers occur, with a smaller chance of
intermittent IFR conditions within any moderate rain showers.
After the showers end, MVFR Cigs are likely to persist at KPOU
and KPSF.
Some showers could reach as far north as KALB, especially
between roughly 14Z-18Z/Tue. These could lead to some MVFR
conditions, esp Cigs. Otherwise, mainly VFR conditions with Cigs
4000-6000 FT AGL.
The showers and any sub-VFR conditions should remain south of
KGFL through Tuesday. However, there is a small chance of patchy
ground fog tonight, which could lead to a few dips into MVFR/IFR
flight categories. This is a low probability, and have left out
mention with current TAFs, but trends will need to be watched in
case amendments are needed.
Winds will remain light (under 5 KT) and variable in direction
through Tuesday.
Outlook...
Tuesday Night: Low Operational Impact. NO SIG WX.
Wednesday: Moderate Operational Impact. Scattered SHRA...TSRA.
Wednesday Night: Low Operational Impact. Isolated SHRA...TSRA.
Thursday: High Operational Impact. Chance of SHRA...TSRA.
Thursday Night: High Operational Impact. Definite SHRA.
Friday: Moderate Operational Impact. Chance of SHRA.
Friday Night: No Operational Impact. NO SIG WX.
Saturday: No Operational Impact. NO SIG WX.
&&
.FIRE WEATHER...
Seasonably dry weather in on tap today as weak high pressure
builds into the region. Disturbances moving along a stalled
frontal boundary south of the region will bring renewed chances
of showers tonight through the day Wednesday, with best chances
south of the Capital Region.
RH values will exceed 45 percent through Wednesday with near
100 percent each night.
Winds will be light and variable at less than 15 mph tonight
and east southeast becoming south at less than 15 mph Tuesday
through the day Wednesday.
&&
.HYDROLOGY...
No widespread hydrological issues are expected in the Albany
Hydro Service Area into the mid week.
Disturbances moving along a stalled frontal boundary south of
the region will bring renewed chances of showers tonight
through the day Wednesday, with best chances south of the
Capital District.
Another wave of low pressure may bring a widespread soaking
rainfall Thursday into Friday, but the amount of rain is still
uncertain. Within bank rises on the main stem rivers is likely.
Please visit our Advanced Hydrologic Prediction Service /AHPS/
web page for specific area rivers and lakes observations and
forecasts.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
MA...None.
VT...None.
&&
$$
SYNOPSIS...NAS
NEAR TERM...KL/NAS
SHORT TERM...NAS
LONG TERM...Thompson
AVIATION...KL/Thompson
FIRE WEATHER...NAS
HYDROLOGY...NAS
Area Forecast Discussion
National Weather Service Amarillo TX
643 PM CDT Mon Jun 17 2019
.AVIATION...
For the 00z TAFs...
Scattered strong to severe thunderstorms currently over eastern
plains of New Mexico expected to impact all of our terminals this
evening. Storms currently moving northeast at around 15 kt.
Expect thunderstorms to begin threatening DHT, GUY and AMA around
00z, 01z and 03z, respectively. Storms expected to cause
variable surface winds briefly gusting above 35 kt with
visibilities briefly falling into MVFR range. Expect that
thunderstorms will have moved east of all terminals by 06z,
although potential exists for redevelopment near AMA between 07z
and 10z.
Tuesday morning expected to be characterized by thinning clouds
and light southwest surface winds. Chance of afternoon
thunderstorms included at northern terminals on Tuesday. Apart
from brief visibility reductions in thunderstorms, VFR conditions
expected next 24 hours.
Cockrell
&&
.PREV DISCUSSION... /Issued 302 PM CDT Mon Jun 17 2019/
SHORT TERM...This Afternoon and Tonight...
Thunderstorms are currently forming in southeastern CO along a
surface trough that extends south into New Mexico. Additional
development is occurring in the higher terrain of NM near a eastward
advancing shortwave, with more recent convective initiation along
the surface trough near KTTC. The shortwave is expected to continue
moving into the area with enhanced PVA by 00z in advance of the
parent trough over southern CA. An axis of better moisture is
expected around the TX/NM border near the surface trough where 850mb
to 700mb theta-E advection is maximized through the afternoon.
Surface dew points were in the mid to upper 50s just east of the
surface trough with 10 to 20 knot south to southeasterly winds. Even
though 700mb theta-E advection is expected to shift east through the
evening, the surface to 850mb moisture drops off from the central
Panhandles into the eastern Panhandles. This results in the
instability axis of around 1500 MLCAPE that extends from the far
western Panhandles Counties into northeastern NM. Veering wind
profiles do support effective shear of 25 to 30 knots, which will be
the main limiting factor for higher levels of convective
organization. That being said, the moderate instability and steep
lapse rates along with the directional shear will support strong
updrafts which may take on supercell characteristic at times as
storms move into out western zones through early evening. These
storms will be high-based given LCL around 2000 m.
As the shortwave dynamics arrive around 00z, additional storms are
expected to develop with more of a linear mode into the evening.
However, as storms move eastward at around 15 to 20 mph, they will
run into more stable airmass, with perhaps only a few hundred J/kg
MUCAPE available in the eastern half of the Panhandles. Given stout
shortwave and 700mb moisture advection, storms will persist but
weaken below severe levels given weak updrafts. As storms first move
into the more stable air, will have to watch for strong downdrafts
given modest DCAPE and decaying updrafts. Can`t rule out a few heat
burst or even some attempt at a wake low developing into the night.
Finally, enough remnant moisture and elevated lift persist across
the western zones so that some re-development is possible after 03z.
This has been a consistent trend in the HRRR mainly favoring the
southwestern Texas Panhandle through about 09z. These storms could
become strong given decent MUCAPE.
Ward
LONG TERM...
On Tuesday a dryline should sharpen up across the western Panhandles
and a cold front should be pushing into the Oklahoma Panhandle by
the afternoon. Forcing may not be strong enough to get
thunderstorms going just by these two features alone as cap will be
fairly strong. However, there is an upper level short wave trough
that will move toward the northern Panhandles, that may provide
enough lift to remove the lid enough to get thunderstorms going. If
thunderstorms develop, then they will probably become severe with
large hail and damaging winds the main threats.
Thunderstorms may move into the northwestern CWA on Wednesday
afternoon from the mountains of New Mexico and Colorado if a short
wave trough can keep the storms going.
The forecast turns dry for Thursday and Friday and temperatures soar
above normal.
Thunderstorms will then again be possible for the weekend as a cold
front moves through the area.
&&
.PRELIMINARY POINT TEMPS/POPS...
Amarillo TX 60 86 60 87 61 / 40 30 10 10 10
Beaver OK 61 86 58 84 61 / 40 40 40 10 5
Boise City OK 57 84 53 81 56 / 60 40 10 20 5
Borger TX 62 87 61 88 62 / 40 30 20 20 5
Boys Ranch TX 58 88 58 88 60 / 50 20 10 20 10
Canyon TX 60 87 59 90 61 / 50 20 10 10 10
Clarendon TX 63 87 63 88 62 / 20 30 20 10 5
Dalhart TX 57 87 55 83 56 / 60 30 10 20 5
Guymon OK 59 85 56 83 59 / 50 40 20 20 5
Hereford TX 59 88 60 92 61 / 60 10 5 5 10
Lipscomb TX 63 86 61 86 62 / 30 50 30 10 5
Pampa TX 61 83 61 86 61 / 30 40 20 20 5
Shamrock TX 64 87 64 88 63 / 20 40 30 10 10
Wellington TX 66 89 66 91 64 / 20 30 30 10 10
&&
.AMA Watches/Warnings/Advisories...
TX...None.
OK...None.
&&
$$
03/77
Area Forecast Discussion
National Weather Service La Crosse WI
1047 PM CDT Mon Jun 17 2019
.SHORT TERM...(Tonight through Tuesday Night)
Issued at 241 PM CDT Mon Jun 17 2019
At 1830Z, a weakly convergent surface boundary was present from Red
Wing MN to just north of Austin MN and southwestward into western
IA. SBCAPES are around 1000 J/Kg along the boundary in sern MN with
showers developing. Further south into IA, thunderstorms were
ongoing near the SBCAPE max of 2000 J/Kg. The moisture is quite
shallow with MLCAPES dropping to 500 J/Kg in sern MN. Thus, more
mixing this afternoon could lower the ambient CAPE for TSRA
potential.
This boundary remains nearly stationary through the evening awaiting
a better push from the northwest, which will come overnight as a
stronger shortwave trough rotates south out of Canada. Right now,
heights are building over the region. Thus, diurnal storms are
expected for several hours west of Highway 52. Wind shear and CAPE
are transposed north and south and not aligning for higher severe
weather threat. But, the boundary could provide a storm anchor and
also a landspout environment to pull heavy local rainfall and
funnels into the possible outcomes through very early evening.
Storms will decrease rapidly in coverage this early evening as any
remaining CAPE wanes, and as the front beings to move south, some
late night moisture transport and convergence in the low levels will
provide another spark to a minimal MUCAPE pool for showers and
thunderstorms early Tuesday south of I-90. Have trended rain chances
higher for this time frame.
Frontal boundary will remain across southern WI into northeast IA
Tuesday afternoon for additional shower/thunderstorm development.
Will keep and eye on this for the possibility of localized heavier
rain amounts given precipitable water values hovering around 1.5"
and potential for training of the showers/storms.
Frontal boundary lingers across southern WI into northeast IA
through Tuesday night but loss of daytime heating with sunset will
diminish shower/storm chances.
.LONG TERM...(Wednesday through Monday)
Issued at 241 PM CDT Mon Jun 17 2019
High pressure drives the aforementioned Tuesday night frontal
boundary further south Wednesday into IL/central IA while a fairly
organized area of low pressure lifts east/northeast out of the
Central Plains. Some lingering mid-level f-gen hangs on across
southern WI into northeast IA for a chance of scattered showers and
isolated storms. Otherwise, northeast surface flow will keep
temperatures in check in the lower/middle 70s.
Stronger ridge of high pressure moves over the area Wednesday night
into Thursday for a brief period of quiet/drier weather. Look for
lows Wednesday night in the upper 40s to the middle 50s and highs
Thursday in the 70s.
Warm air advection and moisture transport ahead of low pressure
moving in across the Plains sets up the stage for more showers and
thunderstorms Thursday night through Saturday. Will have to keep a
close eye on the possibility of some stronger/severe storms Saturday
as GFS shows MUCAPE south of I-90 increasing into the 3500-5000J/Kg
range along with bulks shear around 35kt. In addition, could see
some localized heavy rainfall with these storms.
Surface low pressure progresses northeastward through the area
Saturday night into Sunday, taking the bulk of showers and storms
with it.
Passage of mid-level trough keeps shower/thunderstorm chances going
on Monday.
&&
.AVIATION...(For the 06Z TAFS through 06Z Tuesday night)
Issued at 1047 PM CDT Mon Jun 17 2019
The showers that were moving across the area have all but
dissipated, leaving behind mid-level clouds for a VFR ceiling.
Still anticipating that there will be a increase in the low level
moisture transport into the front over northern Iowa overnight
that should help generate some more showers. The last few runs of
the HRRR have been showing less development than earlier runs and
farther south. Based on this trend, have removed the VCSH mention
overnight along with any MVFR ceilings. Some concern for fog
development overnight, but unsure how much will form underneath
the clouds. For now, will not include any fog and stay with VFR
conditions through Tuesday evening.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
IA...None.
&&
$$
SHORT TERM...DAS
LONG TERM....DAS
AVIATION...04
Area Forecast Discussion
National Weather Service Cleveland OH
1028 PM EDT Mon Jun 17 2019
.SYNOPSIS...
A weak stationary front over the area will begin to lift back
north as a warm front this evening as a wave of low pressure
moves northeast along the front. The low will move east of the
area late tonight forcing the front back south as a cold front
Tuesday. Another low pressure system will move northeast along
the front Wednesday and yet another low will move east across
the area Thursday.
&&
.NEAR TERM /THROUGH TUESDAY NIGHT/...
Minor adjustments to pops, temps and QPF with the evening
update. Main area of precip associated with weak low pressure
moving northeast into the southern part of the area, although
rainfall amounts with this activity are light. The more
moderate/heavy rainfall associated with stronger convection will
remain south of the area over the next several hours. The main
question is how much redevelopment will occur overnight across
the area along and just north of the surface boundary on the
nose of a strengthening low level jet. The latest runs of the
HRRR are bullish on redevelopment shortly after Midnight across
the area, and the runs have been progressively moving the
development northward. Have expanded pops slightly northward as
well as rainfall amounts, but have lowered the overall totals
just slightly for the southern part of the area. There is still
a decent shot at upwards of an inch of rain in isolated
locations overnight, but widespread amounts less than an inch
will be more common. Will leave all headlines in tact given the
potential for additional moderate rainfall amounts.
Original discussion...
Yet another shortwave trough will move east across the area
tonight and will be responsible for pushing a weak low pressure
system northeast into the region. Showers and thunderstorms
continue to break out across southern Illinois and Indiana at
this time. This activity is progged to move northeast across the
southern half of the local forecast area tonight. Moist air
mass will continue to be responsible for periods of moderate to
heavy rain across the south where significant rainfall already
occurred last night. A band of showers continues to move across
this same area at this time and the combination of the two
rainfall events will only compromise the area with more flooding
issues. Rainfall totals up to 1.5 inch additional is expected
across the flash flood watch area overnight. Due to the
potential for locally heavy rain at times in the watch area,
locally higher rainfall amounts are possible. Further north
closer to the lake, the rainfall threat will taper off from
south to north. Patchy dense fog is also possible overnight
again, especially areas where showers have developed this
afternoon and from the recent rain last night further north. Low
pressure pulls out to the northeast Tuesday and tries to pull
the stationary front slightly south. Still thinking that some
lingering showers are possible along the front Tuesday. The
threat diminishes as the night progresses Tuesday night but next
low pressure system will send the warm front back north toward
the area with another round of moisture by morning. Temperatures
across the area will be in the upper 50s near the lake and
middle 60s across the south tonight. Warmer air will lift north
into the region Tuesday into the middle 70s followed by similar
lows for Tuesday night.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
Active pattern with additional rainfall continues in the short term.
The daytime hours on Wednesday expected to me mostly dry and a
little warmer before active weather returns Wednesday night. Low
pressure will develop ahead of a shortwave west of the area on
Wednesday. Moisture surges back north on Wednesday night with
showers and scattered thunderstorms expanding and PW values reaching
1.80 inches. Models continue to show some timing differences with
the NAM/Reg GEM showing the surface low overhead by 12Z Thursday
while the ECMWF/GFS are a little slower. Timing will play a role in
if daytime heating will be a factor for more robust convection on
Thursday afternoon. At this time rain looks like the greatest
concern with most of the area receiving an additional 0.75 to 1.5
inches of rain. Given the strength of the low, can not rule out a
few stronger thunderstorms as well, especially along the warm front
so that will be something to monitor. Instability may be a limiting
factor given the amount of clouds and rain.
Rain will depart to the east on Thursday night, with high pressure
expanding on Friday. Temperatures will drop back into the lower to
mid 70s on Thursday and Friday.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
Wet weather will persist through this period. Dry conditions are
expected Friday night as high pressure builds across and east of the
area by Saturday morning. A warm front will move across the area on
Saturday and produce another round of showers and thunderstorms
which will continue into Saturday night. The region will be in the
warm sector on Sunday with a continuing chance for storms. Models
diverge Sunday and Monday on the approach and passage of a cold
front that is expected to cross the region. More showers and
thunderstorms can be expected.
&&
.AVIATION /00Z Tuesday THROUGH Saturday/...
A frontal boundary will remain stationary just south of the
terminals overnight through Tuesday. IFR conditions are expected
near the front and near the lake at KERI and possible KCLE, with
conditions primarily in the MVFR range at KTOL/KFDY. Showers
will impact mainly KMFD, KCAK and KYNG, and have backed off on
thunder chances slightly given the latest observational and
guidance trends. Winds will be light and variable near the
front, but generally out of the north through the period north
of the boundary.
OUTLOOK...Non-VFR possible through Friday.
&&
.MARINE...
Generally light wind conditions will continue on Lake Erie through
Wednesday as a frontal boundary remains south of the lake. East to
northeast winds will increase late Wednesday night into Thursday
ahead of a low pressure system approaching from the west. Winds of
at least 5 to 15 knots can be expected but could be stronger
depending on the track and strength of the low.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...Flash Flood Watch until 4 AM EDT Tuesday for OHZ017-020>023-
027>033-036>038-047.
PA...None.
MARINE...None.
&&
$$
SYNOPSIS...Lombardy
NEAR TERM...Greenawalt/Lombardy
SHORT TERM...KEC
LONG TERM...LaPlante
AVIATION...Greenawalt
MARINE...KEC
Area Forecast Discussion
National Weather Service State College PA
1137 PM EDT Mon Jun 17 2019
.SYNOPSIS...
An unsettled and stormy weather pattern is expected across
central Pennsylvania this week thanks to the close proximity
of a slowly meandering stationary front over Pennsylvania.
There will be multiple rounds of heavy downpours with the
potential for flooding and isolated severe storms. After a cool
day today, temperatures will get back closer to normal highs for
the rest of the week, but remain milder than normal at night.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
Active night coming up with convection to the west headed
towards central PA. HRRR very consistent with some locally
heavy rain with these storms in predawn hours. One hour FFG is
generally 1.5-2" across the area, PWAT is running 1-2 STDs above
normal for June, and dewpoint 65-70F over the srn third+ of the
CWA. With multiple rounds of showers/storms expected, and the
high moisture of the atmosphere right now, will continue with
FFW even though nothing is immediately expected.
Min temps will vary from the upper 50s across the north, to
upper 60s in the south.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/...
The threat of flash flooding continues Tuesday into Tuesday
night, despite the possibility of a few to several hour lull in
storms late Tuesday morning and early Tuesday afternoon.
The Flash Flood Watch runs into Tue night as additional storms
will ride along on the train later Tues afternoon/evening. The
ground will only be getting wetter, and streams swelling.
Temps may warm a little for the daytime on Tues, but that all
depends on the timing of the minor troughs aloft and how long we
can spend in between the rounds of rain/storms. Have kept the
forecast high in continuity, but could see things being a
little cooler on Tuesday if the storms don`t exit stage right in
the morning, and we get some breaks of sun.
&&
.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
Wet pattern with repeat rounds of rain along nearly stationary
frontal zone will continue to bring an increased flood risk to
south central PA through midweek.
A strong low pressure system for June will track across the area
on Thursday, and could bring a significant threat of severe
storms and flash flooding.
Breezy and drier conditions will arrive into Friday as the
system continues to deepen as it moves away from the area.
The latest guidance favors a dry start to the weekend before
more showers and storms return to the forecast on Sunday.
Persistent cloud cover suggests highs running a bit below
average through midweek while higher dewpoints favor muggy
nights/above avg lows. Near normal temps are forecast through
the weekend.
&&
.AVIATION /04Z TUESDAY THROUGH SATURDAY/...
Abundant low level moisture and light wind in vicinity of a
stalled frontal boundary will lead to developing low cigs and
fog across central Pa overnight, along with the chance of
showers. Latest SREF probability charts indicate IFR conditions
will become likely late tonight over the high terrain of the
Alleghenies from KBFD south through KJST. Further east,
thickening cloud cover could limit the extent of fog formation,
but can`t rule out patchy IFR vsbys.
Diurnal heating and resulting mixing of drier air aloft will
yield improving cigs/vsbys Tuesday, with predominantly VFR
conditions by mid to late afternoon. However, a brief reduction
will remain possible from scattered showers/thunderstorms.
.Outlook...
Wed...AM rain/low cigs possible. Scattered PM tsra impacts
possible.
Thu...AM rain/low cigs possible. Scattered PM tsra impacts
possible.
Fri...AM low cigs possible W Mtns.
Sat...No sig wx expected.
&&
.CLIMATE...
Astronomical summer (solstice) begins Friday, June 21st at
1154AM EDT (1554 UTC).
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
Flash Flood Watch through late Tuesday night for PAZ017>019-
024>028-033>036-049-050-052-056>059-063>066.
&&
$$
SYNOPSIS...Lambert
NEAR TERM...Ross/Lambert
SHORT TERM...Lambert/Evanego
LONG TERM...Steinbugl
AVIATION...Fitzgerald
CLIMATE...
Area Forecast Discussion
National Weather Service Hastings NE
710 PM CDT Mon Jun 17 2019
...AVIATION UPDATE...
.SHORT TERM...(This evening through Tuesday)
Issued at 346 PM CDT Mon Jun 17 2019
Aloft: High-latitude blocking was over the N Atlc with a large
low over Hudson Bay. S of this low...the flow was generally weak
over the CONUS...espcly the S half. There are too many features to
mention...but of concern to our CWA is the large but weak trof
over the Wrn USA. A weak shrtwv trof is lifting NE acrs AZ/NM.
This trof will cont NE tonight and mv into NEB/KS tomorrow.
Probably of greater concern is the RRQ of a 90 kt upr-lvl jet from
SD into the NE USA. By 12Z/Tue...a mid-lvl (700 mb) low is fcst
to form and slowly mv E acrs Srn NEB.
Surface: Occluded/wk low pres was over Nrn MN with a cool front
extending SW acrs the Sandhills. As this low heads into the GtLks
tonight...the front will sag into the CWA tonight and become
stationary along the NEB-KS border tomorrow. Meanwhile...weak low
pres will form along the front (under the mid-lvl low)
approximately from IML-MCK-HJH from 12Z-00Z.
Rest of this aftn: Partly-mostly cldy. Isold shwrs...and possibly
some tstms with the best chance N of I-80 per the last few HRRR
runs. There is not a clr signal on tstm potential. The 12Z HREF
shows that the HRRR is by itself. None of the other CAMs initiate
anything significant. SPC mesoanalysis has about 1000 J/kg with no
more than 20 kts of 0-6 km shr. We`ll downplay threat of svr
tstms in the HWO.
Tonight: Partly-mostly cldy. Sct tstms will occur N and W of the
CWA...along the cool front to the N and over the high plns to the
W. This has already begun. Some of these storms could congeal
into a complex that mvs into the CWA after midnight. Fcst
soundings suggest this situation is ideal for hvy rain with skinny
CAPE...low CAPE totals...slow movement and potential for warm
rain processes.
Tue: The rain that mvs in tonight will cont to progress E acrs
the CWA during the mrng and probably expand thru the day as the
RRQ of the upr jet provides persistent deep lift to supplement
lift associated with low-lvl FGEN. This should result in repeated
development of slow-moving shwrs with embedded tstms.
While PWAT values will not be excessive...they will be abv normal
(1.6"). Cont`d low/skinny CAPE and slow mvmt of the low/rain
should result in some healthy if not excessive rainfall totals.
QPF: The mdl blends and WPC suggest a widespread 1-2" tngt thru
Tue evng. However...some CAMs suggest localized spots could see
3-5".
Soil mstr is still at the 99th percentile. If 3-5" occurs over a
fairly large area...expect flooding will develop in low-lying
areas...creeks and psbly larger rivers. Because of this...hv
issued a Flood Watch from midngt tonight thru Tue evng. The rain
may end by that time...but if flooding materializes...the flooding
could last beyond that.
Contemplated adding some N-cntrl KS counties to the watch gvn the
09Z/SREF probs for at least 3" extend down there. This may need to
be done by the next shift.
There is a chance a few svr tstms could occur in the aftn/evng...
primarily over N-cntrl KS...but it`s conditional on if sufficient
instability can dvlp. Shear will be marginal...maybe as much as 25
kt.
.LONG TERM...(Tuesday night through Monday)
Issued at 346 PM CDT Mon Jun 17 2019
Aloft: The low that has been blocked over the Aleutians will move
downstream into the Nrn Rckys this wk...carving out a longwave
trof over the Wrn USA. As a result...persistent WNW flow here on
the Cntrl Plns will become SW Thu-Sun.
Surface: As the upr low mvs into the Nrn Rckys...a warm front
will form and cross the CWA Wed night as a deep sfc low evolves
over AB. The cool front associated with this low is then fcst to
mv thru Fri.
Temps: Cont`d much cooler than normal Wed. Near normal Thu-Fri.
Then probably cooler than normal Sat-Mon.
Rain: Nothing of significance until Thu night into Fri AM when
the mdls are suggesting an MCS could dvlp and cross part of the
CWA. Sct tstms could also fire Fri aftn along the cool front. SPC
already has the CWA outlooked for a risk of svr tstms. This seems
very reasonable given that rich dwpts in the 60s to low 70s are
fcst to advect N underneath a plume of steep mid-lvl LR`s.
Shr/instability should be more than sufficient for svr tstms as
long as the timing/location of the front holds.
&&
.AVIATION...(For the 00Z KGRI/KEAR TAFS through 00Z Tuesday)
Issued at 710 PM CDT Mon Jun 17 2019
Starting out the period as VFR but conditions are expected to
deteriorate down to IFR overnight and through the day tomorrow and
could flirt the line of LIFR at times.
There is already plenty of storm activity off to the west along the
NE-CO border. These storms are associated with the cool front that
will be moving through the area this evening, and bringing the
active environment with it. Showers and thunderstorms are likely
for most of tonight and tomorrow.
Ceilings are expected to lower gradually to around IFR overnight
with the accompanying frontal system and storms. Visibility could
be impacted at times in heavier storms. Visibility is expected to
drop to between 4-6 SM during the morning hours, and then could
briefly drop further to 2-3 SM in the early afternoon tomorrow,
before ceilings begin to lift.
Winds are expected to become light and variable for a little while
this evening ahead of the approaching front. After the passage of
the front winds will be from the NE and will pick up to around
5-10kts.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...Flood Watch from midnight CDT tonight through Tuesday evening
for NEZ039>041-046>049-060>064-072>077-082>087.
KS...None.
&&
$$
SHORT TERM...Kelley
LONG TERM...Kelley
AVIATION...Shawkey
Area Forecast Discussion
National Weather Service Wilmington NC
1053 PM EDT Mon Jun 17 2019
.SYNOPSIS...
Warm and humid weather conditions continue across the Carolinas
this week as high pressure shifts well offshore. A chance of
showers and thunderstorms will persist each day this week until
the next cold front moves through late in the week.
&&
.UPDATE / 1050 PM /...
Quiet conditions tonight with lows in the low to mid 70s on
track. No major changes to the forecast.
&&
.NEAR TERM /THROUGH TUESDAY NIGHT/...
As of 3 PM Monday...Scattered convection has developed along
the differential heating boundary setup by the coastal plains and
sandhills. Also, isolated convection had formed along the
sea-breeze boundary south of Murrells Inlet. HRRR is a bit slow on
the development and it continues to show the coverage remaining west
of I-95 with only isolated convection elsewhere west of the sea
breeze and dying after sunset.
The depth of the moisture over the region is on the increase and
will be closer to 2" by Tuesday afternoon. Still not much
forcing in the upper levels but as we saw on Sunday any large scale
lift that is undetected will help diurnal convection on Tuesday. The
nam model CAPE values show 2500+ J/kg in the heat of the day
Tuesday. So with the little synoptic scale force will go with a 30%
PoP in the western areas along the sandhills/coastal plains
differential heating boundary and a 20 percent chance along
the sea-breeze,
Lows tonight and Tuesday night are expected to range between the
lower 70s inland to middle 70s at the coast. Highs on Tuesday should
reach the 90 to 93 degree range and will be in the mid 80s at the
beaches.
&&
.SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/...
As of 330 PM Monday...Better chances for rain Wednesday (50%
PoPs) than Tuesday, as shortwave energy embedded in the W/SW
flow aloft moves through the area in conjunction with ~75%
1000-500 mb RH. Convection again should be diurnal in nature,
but still could see some shras/tstms early in the day as well
depending on the timing of the shortwaves. High temps in the upr
80s to lwr 90s. Wednesday night will bring a break in the
pieces of shortwave energy moving overhead and thus only have
20-30% PoPs. Low temps mainly in the mid 70s.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
As of 330 PM Monday...Models have come into better agreement on
the timing of a cold fropa early in the period. The front will
cross the area late Thursday bringing another good chance of
rain, followed by drier conditions Friday into the weekend with
weak high pressure in the vicinity.
Precip Chances: 40-60% chance of shras/tstms Thursday into
Thursday night, decreasing to 20% Friday morning. Dry Friday
afternoon through Saturday, with low diurnal rain chances
returning Sunday.
Temps: Near to slightly above normal through the entire
period...highs avg in the upr 80s to mid 90s, with lows in the
low/mid 70s.
&&
.AVIATION /03Z TUESDAY THROUGH SATURDAY/...
As of 00Z...VFR throughout the period with clear skies. Stratus is
possible Tuesday morning, but over the last few model runs,
continues to look less likely. Calm winds overnight will become
southerly during the day tomorrow as high pressure builds in from
the west. More moisture during the day on Tuesday as compared to
today will provide a good opportunity for scattered thunderstorm
across the area.
Extended Outlook...Mainly VFR with brief MVFR/IFR conditions
Wednesday thru Friday from convection and early morning fog and/or
low stratus.
&&
.MARINE...
As of 330 PM Monday...High pressure well off the southeast
coast will continue to slowly shift off the coast. A trough of
low pressure will move toward the coast late Tuesday. This will
cause the southwest winds of 5 to 10 knots to increase from the
south to 15 knots. The seas will begin around 2 feet tonight and
will increase to 3 to 4 feet farther off the coast Tuesday
night. A southeast swell of 1.5 feet from the southeast is
expected to continue through the near term.
A piedmont trough develops Wednesday and increases the gradient
over the waters to the tune of about 15 kt. Seas should build
to 4 to 5 ft by Wednesday night. A further deterioration in
wind/seas slated for Thursday. Upper-level energy impinges from
the west but low-level wind fields strengthen ahead of a weak
cold front. A Small Craft Advisory could be needed
Thursday/Thursday night. A turn to west and diminishing winds
and seas then expected for Friday and Saturday.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...None.
NC...None.
MARINE...None.
&&
$$
SYNOPSIS...MAS
NEAR TERM...RH
SHORT TERM...MAS
LONG TERM...MAS
AVIATION...21
MARINE...MAS/RH
Area Forecast Discussion
National Weather Service Lincoln IL
913 PM CDT Mon Jun 17 2019
.UPDATE...
Issued at 913 PM CDT Mon Jun 17 2019
Some light rain lingers across east central Illinois this evening,
but low clouds prevail over most of the CWA. Main question will be
with additional shower/storm development. Seriously considered
dropping the Flash Flood Watch near and south of I-70, but decided
to leave it in place as the HRRR brings some heavier showers into
the area toward 3-4 am. Current activity is generally along the
Ohio River and shouldn`t impact us, but the new development appears
to be focused just north of the frontal boundary, which should be
in the general vicinity of I-64 overnight. Temperatures are
generally on track, but some updates for the precipitation trends
have recently been sent.
&&
.SHORT TERM...(This evening through Tuesday)
ISSUED AT 332 PM CDT Mon Jun 17 2019
This afternoon, upper low is slowly lifting across the Ozarks
towards the local area. At the surface, a stationary front is
draped from just south of St Louis ENE along and just south of the
I-70 corridor. Dew points are pooling in the upper 60s to around
70F near the front, while temperatures have warmed to around 80F
in the warm sector. North of the front, low stratus has prevailed
through the day and held temperatures in the 60s to lower 70s.
Thunderstorms are ongoing along the I-70 corridor this afternoon
in response to the shortwave trough that ejected northeast from
the main upper low. These storms have been slow moving in the
presence of weak low and mid level flow, and what movement there
has been is often training over areas already impacted. Anticipate
a corridor or 1 to 2 inches of rain through late this evening,
with locally higher amounts across areas that have already been
well saturated by recent heavy rain events. While the intensity of
the rain hasn`t been too bad so far today, the other
aforementioned factors continue to support a flash flood watch
through at least late this evening if not overnight. This wave
should exit east of the CWA by around sunset this evening, which
coupled with the loss of daytime heating, should allow precip to
wane in coverage. Cannot rule out at least some isolated to widely
scattered convection to continue overnight as the main upper low
begins to accelerate eastward, and the focus will remain in the
far southeast counties of the forecast area.
Overnight, temperatures remain relatively mild under the presence
of cloud cover and high dew points. Clouds should lower again
overnight and cannot rule out some patchy fog redeveloping after
midnight.
On Tuesday, don`t expect much in the way of synoptic scale forcing
over the region and most of the forecast area will remain dry.
Flow aloft becomes zonal in the wake of the damping upper low. The
surface boundary likely persists over the region, however, and
will serve as the main focus for diurnal convection again across
the far southeastern CWA. Guidance suggests modest instability
with MLCAPE to around 1000 J/kg will develop within the warm
sector Tuesday afternoon. Deep layer shear will be weak in the
continued weak mid level flow, so the likelihood of any severe
storms is fairly low.
.LONG TERM...(Tuesday night through Monday)
ISSUED AT 332 PM CDT Mon Jun 17 2019
There has been a good signal for several days now that a shortwave
trough will track across the mid Mississippi Valley on Wednesday.
This wave will intersect moisture rich and unstable air in place
over Illinois on Wednesday resulting in additional chances for
showers and thunderstorms across the forecast area. Some of these
storms could produce heavy rain and will again have to closely
monitor flooding potential during this time frame.
Yet another wave is progged to dig across the Pacific Northwest
Thursday and carving out a deep across the Great Basin over the
weekend. As this occurs, anticipate downstream amplification of
the longwave ridge over the mid section of the country as very
warm (20C+) 850mb temps spread into the Midwest by this weekend.
Thursday and most of Friday should be dry as a result of the
building upper ridge over the region, and a warming trend will
kick off in earnest Friday. Saturday in particular could be hot
over the area, but there remains some uncertainty in how hot given
thunderstorm chances returning along with associated cloud cover.
Near 90F or possibly into the 90s not out of the question
depending on how things come together. Thermal ridge should
persist over the area on Sunday before the upper ridge begins to
break down and shift east early next week.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 700 PM CDT Mon Jun 17 2019
Ceilings are the main concern through Tuesday morning, as light
winds and a low level inversion keep any significantly clearing at
bay. Ceilings around 1500 feet generally found across central
Illinois at 00Z, and these should largely stay in place. Have
included a period of IFR conditions at KSPI/KPIA, with ceilings
just to the south already getting down to that level. Skies
expected to begin scattering out toward midday Tuesday.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
Flash Flood Watch until 7 AM CDT Tuesday for ILZ062-063-066>068-
071>073.
&&
$$
UPDATE...Geelhart
SHORT TERM...Deubelbeiss
LONG TERM...Deubelbeiss
AVIATION...Geelhart
Area Forecast Discussion
National Weather Service Louisville KY
955 PM EDT Mon Jun 17 2019
.Forecast Update...
Issued at 955 PM EDT Mon Jun 17 2019
Scattered convection remains in progress across the western half of
the forecast area this evening. Two clusters of convection will
affect the region overnight. The first will be one area of
convection lifting northward out of Tennessee. This will bring more
widespread showers and thunderstorms to portions of south-central
KY, mainly the Lake Cumberland region. Overall severe threat with
this activity remains low due to the loss of heating and marginal
instability. However, PWATs of 1.5-1.8 inches will allow for
efficient, low-centroid convection that can produce heavy and
efficient rainfall. Given that this area has been drier in the last
few days, FFG guidance in this part of KY remains rather high and
isolated minor flooding issues can be expected.
A second area of convection looks to be developing along a line from
Beaver Dam (Ohio county) northeastward through Metro Louisville and
then northeast to the southern suburbs of Cincinnati. This activity
looks to be focused along a remnant outflow boundary. Mesoscale
analysis shows about 35-40kts of bulk shear here, which may be being
enhanced by the nocturnal low-level jet. Recent HRRR runs suggests
that this line of convection should continue to develop while
lifting slowly northward overnight. Recent radar trends do show
this line drifting northward and current thinking is that an axis of
heavy rainfall will likely fall along the main stem of the Ohio
River over the next several hours. PWATs in this area are around
1.6 to 1.9 inches, so efficient low centroid convection with heavy
rainfall is likely to be the main threat here. Hourly FFG guidance
in the metro is around 1.2 inches but increases to over 2 inches by
the time you get into central Breckinridge/Hardin/Nelson counties.
It drops off considerably to the north across southern IN with around
an inch or so. Values out in the Bluegrass region are also low with
1-1.25 in/hr guidance. Areal placement of the Flash flood watch
still looks good as the watch is placed well within the FFG
guidance. Will need to watch portions of the Lake Cumberland region
overnight as this area could pick up more rain which could require a
southward expansion of the watch given the forecast of more rain
over the coming days.
Issued at 723 PM EDT Mon Jun 17 2019
Scattered convection continues across the region this evening. We`re
starting to see some convection fire along outflow boundaries across
southern IN. A corridor of convection from Dubois county eastward
through portions of Crawford, Floyd, Harrison, and Clark looks
likely over the next few hours. Strongest storms are pushing
northeast out of Trimble county and may catch a portion of Henry
county.
Another area of convection is trying to develop down in the Rough
River area of southern Breckinridge. Fine line outflow boundary
evident in KLVX imagery in that vicinity. Cu field on GOES 16 is a
little agitated, though MLCAPE are only around 900-1300 J/Kg here
and have been decreasing over the last hour or so. Nonetheless,
with PWATs over 1.5 inches, heavy rainfall can be expected with this
activity.
Mesoanalysis generally shows best instability down across south-
central KY from Bowling Green eastward into the Lake Cumberland
area. Tongue of higher DCAPE values exists from the TN Plateau
region northeastward into the Lake Cumberland region. Strong
convection over Middle TN will likely continue northeastward into our
southeast sections this evening. Overall threat of severe weather
is still marginal given the poor lapse rates and tall/skinny CAPE
model proximity sounding profiles. Gusty winds and heavy rainfall
look to be the primary threats. FFG values across the SE are much
much higher than up across the northern half of the state, so
flooding issues will likely be isolated and limited to areas that see
training storms, which could occur in isolated corridors.
&&
.Short Term...(This evening through Tuesday)
Issued at 254 PM EDT Mon Jun 17 2019
Clouds from this morning`s rain have partially broken up and have
allowed some destabilization of the atmosphere, with SBCAPE of 2k-3k
J/kg. Cu has some more vertical development today than it did
yesterday at this time, and a few thunderstorms have already begun
to pop. Expect scattered thunderstorms to continue to develop this
afternoon and continue into this evening. While locally gusty winds
and small hail will be possible with the strongest storms, heavy
rain will be the main threat in 1.8" PWAT air and plenty of moisture
showing up on the soundings. One hour flash flood guidance is below
an inch in some spots over southern Indiana and north central
Kentucky.
Scattered storms will decrease in coverage late this evening, with a
lull in activity before showers and storms ramp back up in the pre-
dawn hours and into Tuesday morning as a vort max moves up from the
Tennessee Valley and brings another threat of locally heavy rain.
Instability tomorrow afternoon should be hampered by the morning
rain, but some scattered development should be possible with a broad
east-west surface front still lined up roughly along the Ohio River
and a weakening upper disturbance moving through.
.Long Term...(Tuesday night through Monday)
Issued at 345 PM EDT Mon Jun 17 2019
The long term portion of the forecast should start off relatively
quiet Tuesday night. Flow aloft looks benign with the next wave
still out over the Plains. Can`t totally rule out isolated showers
given the very humid airmass, particularly east of I-65. Lows in the
upper 60s will be common.
The weather turns more active once again Wednesday afternoon through
Thursday. A convectively-enhanced shortwave is forecast to swing
through Wednesday night with the upper trough moving through on
Thursday. Low pressure is forecast to deepen to the northeast over
the Lower Ohio Valley Wednesday night, with a nice surge in the SW
LLJ (35-40 kts). The proximity of the sfc low will provide a nicely
veered wind profile, and the mid-level wave will bring a speed max
of 50-60 kts. Instability is more marginal, but the moisture-rich
environment will at least support strong storms capable of
torrential rainfall, gusty winds, and lightning. A damaging wind
threat could certainly develop as early as Wed afternoon and
evening. The primary hazard may be flash flooding, especially with
any training convection. The moisture transport surge in the warm
sector will push PWATs into the 1.7-1.9 inch range, so rainfall
production will certainly be efficient.
The cold front sweeps through, bringing drying conditions Thursday
evening. A dry period will likely continue through Friday and
possibly Friday night. Friday morning lows will dip into the low to
mid 60s. Friday looks like a rare nice weather day with highs in the
80s.
The pattern is more amplified through the weekend, and ensemble
means agree on a 594 mid level ridge developing over the Gulf of
Mexico. At some point this weekend, convection in the Plains and
Midwest will likely spill eastward into our region. And the hot,
humid airmass may support at least scattered convection each day
this weekend into early next week.
&&
.Aviation...(00Z TAF Issuance)
Updated at 713 PM EDT Mon Jun 17 2019
Scattered convection will be seen across the region this evening as
an upper level disturbance moves through the region. Outside of
storms, VFR conditions are expected through the evening hours. We
plan on keeping some VCSH/VCTS in the TAFs through 18/03Z or so.
Storms will be capable of brief heavy downpours, gusty winds, and
perhaps some small hail.
High resolution guidance suggests that we`ll see another surge of
convection later on tonight, likely after 18/07Z or so. That
convection will likely linger into the the morning hours on Tuesday
and may result in cigs running near fuel-alternate thresholds.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
IN...Flash Flood Watch through Tuesday afternoon for INZ076>079-083-
084-089>092.
KY...Flash Flood Watch through Tuesday afternoon for KYZ025-029>043-
047>049-055>057.
&&
$$
Update.......MJ
Short Term...13
Long Term....EBW
Aviation.....MJ
Area Forecast Discussion
National Weather Service Melbourne FL
1003 PM EDT Mon Jun 17 2019
.UPDATE...
Current-Tonight...Debris showers across the interior earlier this
evening have since dissipated, leaving a swath of low to mid level
cloudiness over the area. Last several HRRR runs have favored
shower/storm redevelopment overnight across the interior, but most
recent has tapered back on activity. Although 00Z XMR sounding shows
deep moisture pool, (PWAT of 1.94"), have restricted overnight PoPs
for land to the Treasure Coast/Lake O region toward daybreak, as
ambient conditions don`t appear to support redevelopment. Streaming
showers and thunderstorms over the Gulf Stream waters will persist
tonight, with likely PoPs through sunrise. Southwest flow returns as
weak trough axis makes its approach to north FL, slightly tightening
the pressure gradient and sending a weak wind surge over the Gulf
Stream waters. Near normal overnight lows in the low 70s.
&&
.AVIATION...
Earlier convection and debris SHRA has since dissipated, leaving low
to mid level cloudiness across most terminals which will gradually
thin thru daybreak. Models suggest SHRA/TSRA northward push from
KSUA/KVRB near 12Z, however confidence too low to include in current
TAF. SW flow returns overnight, leading to sea breeze push to the
eastern peninsula after 18Z tomorrow. Generally VFR.
&&
.MARINE...
Tonight...(modified prev) Tightening of the surface pressure
gradient overnight will continue the Exercise Caution headlines
for the offshore waters with southerly winds up to 15-20 knots and
seas building to 4-5 ft well offshore. Closer to shore seas up to
3 ft. Higher shower/storm coverage is expected across the
Treasure Coast waters and offshore waters overnight.
Tuesday...SSW/SW winds to 10-15 knots and around 15 knots offshore
with seas 2-3 ft near the immediate coast and up to around 4 ft well
offshore. Numerous showers and scattered storms expected across the
waters.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 72 88 73 91 / 30 60 20 60
MCO 73 89 74 91 / 20 60 20 60
MLB 73 87 72 91 / 30 70 20 60
VRB 73 87 72 90 / 40 70 30 60
LEE 74 88 75 90 / 20 50 20 60
SFB 73 88 75 91 / 20 60 20 60
ORL 73 88 75 92 / 20 60 20 60
FPR 72 87 72 91 / 40 70 30 60
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...None.
AM...None.
&&
$$
Smith/Pendergrast
Area Forecast Discussion
National Weather Service Riverton WY
228 PM MDT Mon Jun 17 2019
.SHORT TERM...(This evening through Tuesday)
Scattered showers/storms are more abundant this afternoon across
the forecast area as heavy rainfall and mainly small hail are
likely with most storms that develop. The short term models
continue to indicate that the low to mid level southeast flow will
be the steering mechanism for the expected southeastward movement
of the storms in a continued low wet bulb environment this
afternoon/mid evening. The HRRR model seems to have a decent
handle on the convective initiation and will trend more with the
HRRR involving placement and timing of the storms through 03Z
tonight. Weak ridging is still progged by the models to take shape
after 03Z tonight, with precip expected to end in all areas
except the far northwest and south central sections of the state
by after 03Z tonight. May have to keep in a slight/isolated
mention of showers/storms in the far south sections through 06Z
tonight.
By Tuesday, the trending still looks in favor of lessening chances
of showers/storms as slightly drier air builds into the region
from the west/northwest. Will lower pops somewhat into the lower
chance category, but still expect early afternoon through mid
evening scattered storms across much of the same area on Tuesday
as today.
.LONG TERM...Tuesday night through Monday
Tuesday night will see a change in the pattern. With more zonal flow
coming into the west expect a good amount of dry air advection in
the upper levels. This will help finish off any convection from west
to east overnight as the dry air caps everything off. Wednesday will
be mostly dry and the warmest day of the extended period. I say
mostly dry as a shortwave will move across the north ahead of our
next weather system. This instability will allow for showers and
thunderstorms across the northern portions of the FA during the
afternoon. Widespread gusty west winds will occur Wednesday
afternoon as the low begins to move out of Canada. Winds will be
strongest west of the Divide reaching the 40 to 45 mph range. East
of the Divide will se stronger winds as well but remain in the 30 to
40 mph range.
Thursday will be mostly dry for the central and south with breezy to
windy conditions and low afternoon relative humidity. High
temperatures will be mild to warm in the central and south. In the
north, isolated to scattered showers and storms will occur in the
afternoon and night. A cold front will be positioned in the north
which would help with storm formation. Cooler high temps in the
north Thursday. Winds will be strong again on Thursday afternoon
with dry conditions in the south. Models continue to show a
developing trough over the northern Rockies Friday through Saturday.
This will increase the chance of showers and storms over the region.
Good news is it looks like the front will push through the FA
overnight Thursday into Friday so the chance for severe weather will
be diminished. Cooler air will move in as well bringing high temps
below normal Friday and Saturday. Sunday looks to be warmer with a
chance of showers and storms in the west with lesser coverage east
of the divide. Southwest flow aloft next Monday with breezy
conditions ahead of the next weather system. Best chance of showers
and storms will be in northwest and northern WY with lesser coverage
elsewhere. Seasonably warm next Monday.
&&
.AVIATION...For the 00Z TAFS through 00Z Tuesday night
VFR conditions will prevail at the terminal sites. Showers and
thunderstorms are expected to continue this afternoon through
midnight tonight. Main aviation threat near these storms will be
variably gusty wind to 30 knots. Local MVFR conditions will occur
with the stronger storms with reduced visibilities and lower
ceilings. Showers and thunderstorms will be decreasing after 06Z
Tue.
&&
.FIRE WEATHER...
Expect scattered showers/storms through late evening tonight and
more development across much of the same areas from north of a
Jackson to Lander to Casper line, extending southeast through
Tuesday evening. Isolated showers/storms may linger past midnight
east of the Divide, tonight. Expect winds to remain generally
light, except in and near storms through the time period. Smoke
dispersion values will be fair to good through Tuesday, with
trending indicating that there will be lower relative humidity
values, increasing winds and lower showers/storms chances
Wednesday and Thursday.
&&
.RIW WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Troutman
LONG TERM...Hulme
AVIATION...Hulme
FIRE WEATHER...Troutman
Area Forecast Discussion
National Weather Service Blacksburg VA
858 PM EDT Mon Jun 17 2019
.SYNOPSIS...
A stationary front will linger over the Mid Atlantic this week.
Waves of low pressure should track eastward along this front,
which will provide a daily threat of showers and thunderstorms.
Warm and humid conditions should continue through this time.
&&
.NEAR TERM /THROUGH TUESDAY/...
As of 900 PM EDT Monday...
Clusters of showers and isolated thunderstorms continue to
linger across southern/southwest sections this evening, mostly
in areas that have not been worked over from earlier convection.
Also appears that a convectively induced wave looks to be
lingering along the foothills per broad turning seen on radar
loops. Latest HRRR keeps some of this convection going for a few
more hours before loss of heating/instability finally cause most
showers to fade around midnight. However can see some of this
continuing to spread east via redevelopment given the current
lingering axis of higher Cape values in the southeast. Expect
these mostly to be heavy rain produces per Pwats nearing 1.5
inches this evening. Therefore keeping likely pops going in
spots over the south with low chances north to Highway 460 attm.
Muggy lows in the 60s with some staying above 70 with some
patchy fog around.
Previous discussion as of 200 PM EDT Monday...
The 12Z RNK sounding reveals a precipitable water of 1.20 inches
and a considerably high freezing level. Wind shear is rather
light, so the threat for any severe weather this afternoon
appears marginal. However, thunderstorms that develop will be
quite efficient in producing rainfall. CAPE should exceed 2,000
J/kg during the next couple hours, which will increase the
expected coverage of storms.
By tonight, the showers and thunderstorms should wane as
instability decreases. Leftover cloudiness from earlier
convection and the humid air mass will keep low temperatures in
the 60s. More showers and thunderstorms appear likely for
Tuesday as a shortwave upper level trough moves overhead. As a
result, POPs were increased across the CWA. Again, heavy
rainfall will likely occur in the storms due to the high
freezing levels and above average precipitable water. SPC also
maintains a marginal threat of severe weather for Tuesday.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/...
As of 300 PM EDT Monday...
Showers/Storms associated with upper level shortwave trough are
expected to move east of the forecast area after midnight
Tuesday, increasing stability and west-northwest downslope wind
bringing an end to the convective threat. Will maintain slight
chance pops to account for any lingering showers late Tuesday
night into Wednesday morning but think overall chance for rain
will end with passage of the shortwave and onset of negative
vorticity advection (NVA).
Wednesday will likely be a down day with respect to thunderstorm
threat as we will be in the wake of the departing short wave.
Surface heating and may initiate some isolated showers/storms
Wednesday, but coverage sub-par since forcing mechanism limited
to just the heating of the day. Better opportunity for
showers/storms is expected to occur Thursday associated with
dynamic lift from another short wave trough...this trough moving
quickly from west to east via modest zonal flow.
Elevated PWATs of 1.25 to 1.75 are forecast the entire week, so
showers/storms that do occur will be rain efficient. Surface
dewpoints are also forecast to remain at or above 65 so it will
remain muggy, temperatures ranging from the 60s at night to the
80s during the day.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
As of 330 PM EDT Monday...
Expect a drying trend for Friday and Friday night as winds
likely to remain northwesterly in the wake the passage of
Thursday`s short wave trough. Plenty of mid level drying
progged as well, so shower/storm activity would be
unfavorable. Can`t rule out a rogue shower far west for any
upstream activity which may cross the Ohio Valley, but think
Friday as a whole for our forecast area will be dry.
The drying is expected to be short-lived however as upper ridge
builds in again by Saturday along with return of deeper
moisture for the entire weekend. Thus chances of showers/storms
increase Saturday and more so into Sunday. Near seasonal
temperatures and increasing humidity as well through next
weekend. Generally pretty good agreement in the guidance for
these trends through the upcoming weekend.
&&
.AVIATION /01Z TUESDAY THROUGH SATURDAY/...
As of 710 PM EDT Monday...
Showers and isolated thunderstorms will continue to linger into
this evening before slowly fading to mainly VFR with the
exception of patchy fog overnight. Thus plan to continue either
a vicinity mention or TEMPO in some lower conditions in residual
showers espcly south and west through about midnight. Expect
areas of MVFR to IFR conditions in fog/stratus overnight espcly
in spots that received earlier heavy rain. However debris clouds
as well as upstream cloud cover could inhibit it to some
extent.
VFR conditions should resume for Tuesday morning, but showers
and thunderstorms appear likely to fire again in the afternoon
as a wave of low pressure passes overhead. Coverage of this
convection could become rather widespread with the potential for
MVFR conditions, gusty winds, and turbulence at all TAF sites.
Therefore given higher confidence included either prevailing
showers/storms or vicinity mention for convection Tuesday
afternoon.
Extended Aviation Discussion...
A stationary front over the Mid Atlantic along with waves of low
pressure tracking eastward along this boundary should keep an
active weather trend through Thursday. Showers and thunderstorms
will likely develop each afternoon and evening, which will
produce areas of MVFR and heavy rainfall. MVFR or IFR conditions
from fog or low clouds may also occur during the late night
hours due to increasing moisture. By Friday, a cold front should
shove the stalled boundary offshore, and drier air from high
pressure will bring VFR conditions through Saturday.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...None.
NC...None.
WV...None.
&&
$$
SYNOPSIS...PW
NEAR TERM...JH/PW
SHORT TERM...PM
LONG TERM...PM
AVIATION...JH/PW
Area Forecast Discussion
National Weather Service Las Vegas NV
800 PM PDT Mon Jun 17 2019
.SYNOPSIS...
The region will dry out by mid week and temperatures will gradually
warm to above normal. Another weather disturbance will bring
gusty winds across the region Thursday and drop temperatures to
below normal by Friday.
&&
.UPDATE...Showers and thunderstorms look to be losing energy
relatively quickly as the sun begins to set and stability increases.
Lingering shower activity in southeastern California and
northwestern Arizona should cease in the next few hours. Similarly,
skies are expected to clear out overnight. Temperatures remain in
the mid-90s at the moment, but substantial cooling will take place
when the skies clear, as noted in the current hourly grids. No
changes to the forecast necessary at this time.
&&
.PREVIOUS DISCUSSION...152 PM PDT Mon Jun 17 2019.
.DISCUSSION...
Shower activity from the shortwave disturbance is generating a
fair amount of showers and isolated thunderstorms across the area.
This activity will begin to wane as we head into the evening
hours. One concern is that much of the activity over central Nye
and Lincoln Counties may kick out a moderate strength outflow
boundary that will head south and affect the central to southern
parts of our area including the Las Vegas Valley this evening.
The HRRR model has been consistent in forecasting this feature.
The winds are not expected to be severe or damage producing.
However, if it does materialize it could bring wind gusts of 30-40
mph and have an impact on air traffic at McCarran along with any
outdoor activities planned this evening.
Beyond this evening, the upper level pattern remains persistent
with the CWA caught in the deformation zone as a upper low forms
off the southern California coast. Residual moisture in the area
will keep the threat of afternoon showers across the central and
northern portions of our area. There is likely to be some
variability in the day-to-day location of this activity, but
generally in a east-west band across the central part of our CWA.
Toward the end of the week a broad upper low will dive into the
Great Basin region mainly bringing gusty southwest winds across
our area. Models are getting more consistent in indicating that
wind advisory criteria may be possible Thursday across the Mojave
Desert with gusts up to 40-45 mph. By late Thursday into Friday, a
surface cold front will push into the region dropping
temperatures 7-10 degrees by Friday afternoon. Thereafter, expect
dry, northwest flow through the weekend.
&&
.FIRE WEATHER...
Temperatures will gradually warm up through mid week and afternoon
relative humidity will fall to single digits across the deserts.
Expect these conditions to dry the near-critical fuels further
this week. Critical or near-critical conditions may develop later
this week as a weather disturbance brings gusty winds to the region
Thursday.
&&
.AVIATION...For McCarran...Easterly winds will gradually give way
to southwesterly winds this evening following the typical
pattern. There remains a likely scenario where thunderstorm
activity north of Las Vegas kicks out an outflow boundary that
will bring gusty north winds to the terminal around 5 UTC and last
an hour or two before returning to southwest. Updates to the TAF
will be made if this scenario becomes more likely.
Beyond this evening, chances for thunderstorms farther north will
decrease on Tuesday, leading to a more typical wind regime of
light easterly during the day becoming south southwest at night.
For the rest of southern Nevada, northwest Arizona and southeast
California...Showers and thunderstorms over Lincoln and central
Nye Counties will continue through sunset. There remains a likely
scenario where these thunderstorm kick out an outflow boundary
that will bring gusty north winds southward across southern Nevada
and the Colorado River Valley early this evening. This will need
to be watched and area TAFs will be updated as needed.
&&
.SPOTTER INFORMATION STATEMENT...Spotters are encouraged to report
any significant weather or impacts according to standard operating
procedures.
&&
$$
UPDATE...Varian
DISCUSSION...Lericos
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