Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 06/19/19
AREA FORECAST DISCUSSION
National Weather Service Albany NY
1025 PM EDT Tue Jun 18 2019
.SYNOPSIS...
Fair weather is expected tonight and Wednesday. Some isolated
showers and thunderstorms are possible Wednesday. A storm
system moving through the mid Atlantic states may bring a steady
rainfall Thursday into Friday.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
As of 1020 PM EDT...Just a few residual showers across the
Adirondacks which is across a diffuse boundary (and lake
boundary from earlier in the day) that extends southwest toward
the Finger Lakes region. HRRR suggests some of these upstream
showers may approach the western areas while they dissipate.
Otherwise, per the H2O vapor loop, ample moisture remains in
place as variable cloud coverage with light and variable winds.
If enough breaks occur overnight, especially where rain fell
earlier in the day, patchy fog will be the result.
Prev Disc...
Rain in the process of exiting the southern Berkshires, mid
Hudson Valley and NW CT. There is some clearing behind the area
of rain and much of the night should be partly cloudy to mostly
clear outside of some areas of high clouds, and some patchy fog
developing in some areas after midnight.
The patchy fog and lingering trapped low level moisture beneath
mid and upper level dry air, could contribute to the development
of some low clouds in some areas before and around sunrise.
Still, light winds and some weak subsidence through the night
will help temperatures fall to the mid 50s to around 60.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/...
There are really no well defined upper impulses seen in data or
sources of guidance/ensembles affecting our region through
Wednesday night. The diffuse low level wind shift and moisture
boundary to our south is expected to drift very slowly north as
upper heights very slowly rise within the northern periphery of
flat upper ridging. So, mid and upper level dry air will be in
place over much of the region with low level moisture and
boundary layer temperatures slowly rising. There could be an
isolated to scattered shower or thunderstorm mainly Wednesday
afternoon and evening but there should also be enough sun to get
temperatures solidly into the 70s to around 80.
By Thursday, well defined upper energy tracking across the
midwest and OH Valley will approach our region. There are still
differences in sources of guidance/ensembles in terms of how far
north the greater instability and stronger low level forcing
gets. The best coverage of showers Thursday morning will be in
western and northern areas but some scattered showers could
develop into eastern NY and western New England by early
afternoon.
There should be more clouds than sun for most of Thursday,
especially in western and northern areas, then becoming cloudy
everywhere through the afternoon as showers and thunderstorms
expand across the entire region. Areas from the eastern
Catskills through mid Hudson Valley through NW CT have the best
chance at more significant instability and being in the leading
convergent zone of a low level jet segment and thermal moisture
boundary along the cold front.
Again, there are sources of guidance that keep the significant
instability south of our region but boundary layer and midlevel
convergence within some semblance of a developing upper
deformation zone north of the stronger convection could provide
embedded convective elements and locally heavy rain extending
north through our entire forecast area later Thursday afternoon
through much of Thursday night. Chances for severe thunderstorms
and the potential for localized urban and small stream flooding
will continue to be monitored. Highs Thursday in the lower to
mid 70s but around 70 north and upper 70s southern areas.
Rain exits through Friday morning and improving sky with low
level drying and cooling expected through Friday afternoon. It
could be quite breezy Friday afternoon as well. Highs Friday in
the upper 60s to mid 70s.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
Several discrepancies remain in the long term portion of this
forecast as the latest version of the GFS-FV3, ECMWF, GGEM and ICON
all vary to the extend of the trough amplification across the
northeast and upstream progression of the approaching warm front.
There is rather high confidence that the upcoming weekend period
should remain dry as upper low and surface lows become vertically
stacked in the Canadian maritimes. This places our region within a
northwest flow regime with slowly rising heights and surface ridge
axis sliding southeastward across the region. There might be enough
of a cold pool aloft for terrain based clouds and isolated showers
to the north and east of Albany but we will keep conditions dry in
the forecast at this time. Near seasonable temperatures too for the
first weekend of summer with average highs into the 70s and near 80F
for valley locations and overnight lows into the 50s and near 60F
for valley locations.
Heading into the first full week of summer, models diverge further
with the GFS-FV3 more aggressive with the upstream warm front
approach than the ECMWF/GGEM/ICON. Mixed ensemble signals as well
with some hints of the ridge holding on a little strong to extend
our dry weather pattern through Tuesday. However, per coordination
and still some chance, we will continue with the previous forecast
for some showers and perhaps a thunderstorm through early next week.
The thermal profiles do moderate as it would seem with a late June
sunshine we should see more 80s evolve for valley locations and
overnight lows moderate into the 60s.
&&
.AVIATION /02Z WEDNESDAY THROUGH SUNDAY/...
As showers dissipate, we are left with light and variable winds
along with borderline VFR/MVFR conditions. Expectations are for
flight conditions to become MVFR and possibly IFR with patchy
fog/low-stratus developing overnight.
The low-level moisture will gradually mix out by mid-morning
Wednesday, with perhaps a few showers popping up by Wednesday
afternoon.
Winds will remain light throughout the TAF period.
Outlook...
Wednesday Night: Low Operational Impact. Slight Chance of SHRA...TSRA.
Thursday: High Operational Impact. Definite SHRA...TSRA.
Thursday Night: High Operational Impact. Definite SHRA...TSRA.
Friday: Low Operational Impact. Breezy Isolated SHRA.
Friday Night: No Operational Impact. NO SIG WX.
Saturday: No Operational Impact. NO SIG WX.
Saturday Night: No Operational Impact. NO SIG WX.
Sunday: No Operational Impact. NO SIG WX.
&&
.FIRE WEATHER...
Fair weather is expected tonight and Wednesday. Some isolated
showers and thunderstorms are possible Wednesday. A storm
system moving through the mid Atlantic states may bring a steady
rainfall Thursday into Friday.
RH values will exceed 45 percent through Thursday with near 100
percent tonight and Wednesday night. Widespread showers and
scattered thunderstorms are expected Thursday.
Winds tonight will be light and variable. On Wednesday and
Wednesday night, winds will be south to southwest at 10 mph or
less. Winds Thursday will be northeast to southeast at 15 mph or
less.
&&
.HYDROLOGY...
Isolated to scattered showers and thunderstorms are expected
through Wednesday night. A wave of low pressure is expected to
bring a widespread soaking rainfall Thursday into Friday with
amounts between three quarters of an inch and an inch and a
half. The rain is expected to cause only within bank rises on
the main stem rivers.
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...BGM/NAS
SHORT TERM...NAS
LONG TERM...BGM
AVIATION...BGM/Thompson
FIRE WEATHER...NAS
HYDROLOGY...NAS
www.weather.gov/albany
Area Forecast Discussion
National Weather Service Bismarck ND
1008 PM CDT Tue Jun 18 2019
.UPDATE...
Issued at 1008 PM CDT Tue Jun 18 2019
Scattered thunderstorms over southwest and south central North
Dakota have greatly diminished over the last hour. There has also
been a diminishing trend in the convection approaching from
eastern Montana. Given these trends along with the RAP now showing
less than 500 J/kg MUCAPE overnight, opted to lower thunder
potential to just a slight chance. Meanwhile, a small area of
showers has been sitting over northwest Pierce and northeast
McHenry Counties for the past few hours. It is not entirely clear
what is causing this, though there may be a very weak disturbance
in the vicinity, per water vapor imagery.
Other changes for this update include adjusting PoPs and sky
cover to better match short-term trends. Also increased low
temperatures by a few degrees over western North Dakota, where
cloud cover is increasing and dewpoints are expected to hold in
the lower to mid 50s.
UPDATE Issued at 714 PM CDT Tue Jun 18 2019
No major changes are needed for this update. Scattered
thunderstorms continue across parts of southwest North Dakota
early this evening. As of this writing, the strongest storm was
located over central Grant County, which has exhibited some
characteristics of a left-moving supercell. The expectation
remains that these storms will slowly dissipate through the
evening as diurnal instability begins to decrease.
&&
.SHORT TERM...(This evening through Wednesday)
Issued at 129 PM CDT Tue Jun 18 2019
Shower and thunderstorm chances will highlight the short term
period of the forecast.
Currently, low pressure is situated over far southeast Montana
with perhaps a warm front east through northwest South Dakota, and
then extending south from there. There is weak to moderate MUCape
over southwest North Dakota. In addition a small area of 0-6km
bulk shear is also situated over the same area. RAP forecast
soundings indicate the greatest instability and shear will exist
early to mid afternoon, before tapering into the late afternoon
and early evening. The most likely severe threat would be quarter
sized hail or locally severe gust. Area hodographs are not too
impressive, but at least early this afternoon there is some
minimal helicity.
Although the overall chances are low, the far southwest would be
most likely area for a brief severe storm this afternoon. Tonight,
increasing warm advection will combine with shortwave energy which
is currently exiting the northern Rockies. This will result in
surface cyclogenesis in northwest South Dakota, with widespread
showers and embedded thunderstorms spreading from western into
central ND late tonight through Wednesday west to east across the
forecast area. Initially, the threat of severe weather will be
minimal, however, by Wednesday afternoon after the initial wave
of shower and thunderstorm activity moves through, we could become
slightly to moderately unstable over far southwest and far south
central ND. For instance, the 12 UTC NAM forecast sounding for
Ashley ND, indicates around 1200 J/KG of MUCAPE with 45kts of bulk
shear and a nicely curved hodograph with abundant 0-3km helicity.
The problem will be, actually clearing out and destabilize during
the afternoon. It looks to be a pretty small window, with a much
more stable atmosphere as you head north and less favorable of a
shear/helicity setup as you get into the far southwest. Given the
uncertainty, will not mention severe wording in the forecast at
this time, but will segment out portions of the far southwest and
far south central for marginal severe hazards.
.LONG TERM...(Wednesday night through Tuesday)
Issued at 129 PM CDT Tue Jun 18 2019
Showers and thunderstorms will continue into at least the early
portions of the extended forecast.
An upper level low becomes situated in the lee of the southern
Canadian Rockies Wednesday night. A shortwave rounding the base of
the low is expected to spark another round of showers and
thunderstorms spreading southwest to northeast late Wednesday
night through Thursday morning, and possibly lingering through the
day over our northern and eastern counties. At this time it
appears it will be cool enough that the threat of severe weather
will be minimal. The far southwest could be a concern again as
this would be the area to potentially see the sun break out and
destabilize the atmosphere enough for moderate instability. But
this is a bit too far out for any mention of severe at this time.
The upper level low remains over the northern High Plains with the
center of the low over northeast Montana by Friday afternoon. This
will keep a good chance of showers and thunderstorms in the
forecast through Friday.
That upper low over northeast Montana lifts north of the area
early in the weekend, but lingering upper level troughing remains
over the area through the weekend, and then we transition to a
brief quasi-zonal flow as another upper low takes shape off the
Pacific Northwest Coast. This will keep at least a slight chance
of showers and thunderstorms over the weekend and into early next
week, but certainly not as widespread as this Wednesday through
Friday. Temperatures will remain cool Through the work week, with
several rounds of showers and thunderstorms. Then a little bit of
a warming through through the weekend and into early next week.
&&
.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 714 PM CDT Tue Jun 18 2019
VFR conditions are expected through the evening, although
thunderstorms may approach KDIK through 03Z. Additional showers
and storms are forecast to move into western ND late tonight,
spreading east through Wednesday morning. MVFR ceilings are also
expected to develop Wednesday morning across western and south
central ND. Brief periods of MVFR visibility and gusty winds may
be possible if a storm passes over a terminal. Otherwise, expect
southeasterly winds around 10 kts Wednesday afternoon.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Hollan
SHORT TERM...TWH
LONG TERM...TWH
AVIATION...Hollan
Area Forecast Discussion
National Weather Service Cheyenne WY
507 PM MDT Tue Jun 18 2019
.SHORT TERM...(This evening through Thursday)
Issued at 110 PM MDT Tue Jun 18 2019
Tonight...As depicted with current radar trends, as well as the
models indicating plenty of low and mid level moisture available
along with a passing shortwave trough aloft, expect scattered to
numerous showers and thunderstorms this evening, with a decrease in
areal trends after midnight. Some of the storms may produce locally
heavy rainfall considering precipitable water values.
Wednesday...Drier, warmer and windy as the low level winds turns
westerly, helping to advect in drier air at low and mid levels.
Looks like enough moisture for isolated late day showers and
thunderstorms mainly east of Interstate 25. Will need to watch the
projected winds over our wind prone locations.
Thursday...The flow aloft backs to west southwest in advance of the
next approaching trough. This will induce surface low pressure over
southeast Wyoming and the available moisture will combine with low
level convergence to produce scattered to numerous showers and
thunderstorms in the afternoon and evening.
.LONG TERM...(Thursday night through Tuesday)
Issued at 110 PM MDT Tue Jun 18 2019
Friday...Similar coverage of showers and thunderstorms compared to
Thursday, although temperatures will be cooler with more cloud cover
and in the wake of a passing cold front.
Saturday...Even cooler with more cloud cover and chances for showers
and thunderstorms in advance of the approaching trough aloft over
western Colorado.
Sunday...Chances for late day showers and thunderstorms will
continue with the passing of a shortwave trough aloft, though
temperatures will be warmer with more sunshine compared to Saturday.
Monday...The flow aloft becomes zonal with weak shortwave ridging
aloft overhead. Looks like adequate low and mid level moisture for
isolated afternoon and evening showers and thunderstorms.
Tuesday...The warming trend continues as 500 mb heights rise some 70
meters from Monday, and with downslope winds helping the warming.
Looks like enough low and mid level moisture for isolated late
day showers and thunderstorms, limited in coverage by the warm
temperatures aloft.
&&
.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 504 PM MDT Tue Jun 18 2019
Convection ongoing this afternoon across much of southeast Wyoming
and Nebraska Panhandle. Greatest concentration over the Panhandle
at this time. Look for a decrease in coverage after sunset. SOme
low clouds again expected out near the Panhandle overnight...but
latest HRRR and SREF output showing lower clouds to east. Makes
sense with the westerly downsloping winds...so did not go to far
on IFR/LIFR conditions tonight. Will continue to monitor this
evening.
&&
.FIRE WEATHER...
Issued at 110 PM MDT Tue Jun 18 2019
Minimal concerns through the next week. Somewhat lower humidities
Wednesday and Thursday afternoons, then higher humidities for
Friday through the weekend, then lower humidities on Monday and
Tuesday.
&&
.HYDROLOGY...
Issued at 110 PM MDT Tue Jun 18 2019
Overall not much change is expected in the flood
situation through the next several days. Precipitation chances will
remain likely for the area through Today. A brief break with drier
weather is expected Wednesday and Thursday before wet conditions
return this weekend and next week. High volume flows are expected to
continue at Saratoga and other area rivers and streams. A continued
wet and active period will continue to pose a hydro threat through
the extended.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...None.
NE...None.
&&
$$
SHORT TERM...RUBIN
LONG TERM...RUBIN
AVIATION...GCC
FIRE WEATHER...RUBIN
HYDROLOGY...RUBIN
Area Forecast Discussion
National Weather Service Dodge City KS
552 PM CDT Tue Jun 18 2019
.UPDATE...
Issued at 552 PM CDT Tue Jun 18 2019
Cancelled tornado watch for Ford, Clark, Hodgeman and Pawnee
counties. Remaining storm near Kinsley is dissipating, with
outflow/composite weak front south of Dodge City. Severe weather
is in progress across SE Colorado and the northern panhandles, and
the expectation is some of this activity should enter SW Kansas
this evening. HRRR has strong to severe storms in far SW Kansas
around 9 pm. Will keep pops relatively high overnight for this
expected additional round of convection.
&&
.SHORT TERM...(This afternoon through Wednesday)
Issued at 1142 AM CDT Tue Jun 18 2019
We continue to monitor the possibility of two rounds of
storms...the first round this afternoon mainly for areas from
the I-70 corridor to the Pratt and Medicine Lodge areas which
could have straight line winds, brief QLCS tornadoes, and flash
flooding. The second round will come in from eastern Colorado
this evening and move across southwest Kansas through midnight.
At the time of writing this discussion a mesoscale convective
vortex continues in north central Kansas with a stationary front
located roughly from Hays to Lamar, CO. CAPE values are continuing
to increase south of the front with already MUCAPE values
approaching 2000 in spots. CAM models are all in pretty good
agreement that the convective mode with the storms will be a QLCS
line and less likely a discrete supercell will last more than an
hour. Weak bulk shear values from 0-10 km should promote quick
upscale growth of storms. 0-3 km shear vectors look to be out of
the southwest at 30 kts which could promote a few QLCS tornadoes
in the line especially where the line bows back to the northwest
along with a straight line wind threat.
PW values in the 1.5-1.75" range suggest these storms will be
quite water loaded so that along with the weak bulk shear suggest
that hail will not be a great threat with these storms. Flash
flooding certainly will be since we already have some reports of
minor street flooding in Pawnee county from the morning convection
and a slight risk of flash flooding from the WPC.
Indications are the initial QLCS line will move out of our area
around 01-02Z and then the attention turns to the convection which
will develop in the front range of the Rockies and move into
western Kansas. If this area from Dodge City on west is
relatively untouched by the afternoon convection the evening
convection should have still an area of 1500-2000 CAPE to work
with which will provide a straight line wind risk along with more
localized heavy rain. The line of convection should move at a
pretty good clip so that by early Wednesday morning we should be
done with the storms and left with a quieter day.
Wednesday a high moves in behind the convective complex and we
should see clearing skies through the morning. There remains a
slight chance of some pop up storms in the afternoon mainly west
of Highway 83 with another slight shortwave moving in from the
northwest upper level flow pattern we will have.
.LONG TERM...(Wednesday night through Tuesday)
Issued at 1256 PM CDT Tue Jun 18 2019
Thursday into Friday could be a couple of the hottest days of the
season upcoming as the upper flow and low level winds will be out
of the southwest as GFS and Euro are indicating 850 mb
temperatures will be in the upper 20 (C) range. Dewpoints will be
in the mid to upper 60s on Thursday with highs in the lower 90s.
Then the air should be drier on Friday which will allow highs to
make it into the mid 90s.
A strong cold front with a upper level trough should come in
through Saturday morning which could provide some storms along the
I-70 corridor. Temperatures should fall back into the 80s.
Long term models introduce another round of front range storms
moving through western Kansas from Saturday night into Sunday as
an upper level trough moves through.
At this point it does look like a couple of dry days to start
early next week as the trough exits and the upper level pattern
turns more zonal.
&&
.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 440 PM CDT Tue Jun 18 2019
Winds will trend light N/NW this evening and tonight as a weak
frontal boundary sags through SW Kansas. Initial convection has
avoided the terminals this afternoon. Additional thunderstorms are
expected to arrive from Colorado this evening, with the HRRR/18z
NAM forecasting convection along the CO/KS border 00-01z Wed.
Included convective TEMPO groups at GCK, LBL and DDC for this
expected activity (03-06z) as it progresses east this evening.
Consensus of short term models shows post-frontal IFR stratus cigs
developing through 12z Wed, with the highest confidence/lowest
ceilings at HYS. MVFR stratus may evolve as far south as DDC
Wednesday morning with NW winds of 10-20 kts.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 60 79 65 90 / 90 10 10 10
GCK 57 82 64 90 / 80 10 20 0
EHA 55 81 61 91 / 40 10 0 0
LBL 56 80 65 91 / 40 10 10 0
HYS 60 77 64 87 / 30 10 0 10
P28 64 81 66 90 / 70 10 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Turner
SHORT TERM...Tatro
LONG TERM...Tatro
AVIATION...Turner
Area Forecast Discussion
National Weather Service Des Moines IA
633 PM CDT Tue Jun 18 2019
...Updated for 00z Aviation Discussion...
.SHORT TERM.../Tonight through Wednesday Night/
Issued at 319 PM CDT Tue Jun 18 2019
Confidence: Medium
Main challenge continues to be the MCV over northeast Kansas and the
track tonight into Wednesday. Models have been tracking the system
mainly to the east with the heavier precipitation expected to remain
south of the forecast area. Weak trough over the south will likely
be the focus of additional showers/thunderstorms this afternoon and
evening as some mechanical forcing from the MCV combines with the
boundary. The high res models are somewhat divergent on the track of
the MCV overnight with the NMM farther north than the ARW with the
HRRR not tracking the system very well at this time. Current trends
suggest that the track may be a bit farther north. With that in
mind, have boosted PoP and rainfall amounts over the south during
the late overnight and into Wednesday morning. Across the weak
boundary, precipitable water values remain in the 1 to 1.5 overnight
into Wednesday morning. Warm cloud depths continue to reach about
9500 to 11000 feet over the south third of the forecast area this
afternoon and tonight. This may again result in some locally heavy
downpours with brief heavy rainfall in some of the heavier storms.
Though overall rainfall amounts should range from 0.25 to 1.25 in
the southern third, local amounts may again approach 2 to 2.5
inches in some of the heavier storms. Though widespread water
issues are not expected, there may again be some localized urban
runoff that may impact streets due to the slower movement of some
of the showers and thunderstorms this afternoon. Will maintain
higher pops and qpf over the south tonight into early Wednesday as
the MCV tracks across Missouri. Lows tonight should hold in the
lower 60s south and in the lower to mid 50s over the north.
Similar to previous nights, some patchy fog may also occur over
the region. For tomorrow, highs will be held down over the south
with generally thick cloud cover and showers and storms in the
area. Have cut back highs into the lower 70s south and left the
north in the mid 70s for the afternoon hours. The system will pull
east of the region Wednesday night and with some clearing, fog is
going to be more likely over the region; especially in the south
where more rain is expected tonight through Wednesday. Lows
Wednesday night will fall into the mid 50s to around 60 south.
.LONG TERM.../Thursday through Tuesday/
Issued at 319 PM CDT Tue Jun 18 2019
Confidence: Low to Medium
Though the early portion of the extended forecast looks similar to
previous forecasts, as the weekend rolls around some changes are
beginning to show up in the medium range models and this is lowering
day to day confidence on details of the forecast at this time.
Overall, the transition to southwest flow is still intact with
instability increasing by Friday and wind fields strengthening as
well. First off for Thursday, a northern stream shortwave will
swing northeast with a warm front moving back north through Iowa
with warm air advection and chances for showers and thunderstorms
Thursday. Highs Thursday will be similar to the past milder days
with upper 70s south and mid 70s over the north where rain chances
will be higher. By Thursday night into Friday morning, both the
GFS/Euro are now initiating an MCS along a new resurgence of thetae
advection into Iowa, though at this time the spread of solutions
lowers confidence on whether southern/central Iowa would be more
favored for the track of the mesoscale system into Friday afternoon.
With precipitable water values in the 1.50 to 1.75 inch range,
rainfall amounts with any system tracking across the region could
drop another 1 to 2 inches of rainfall. In fact, through much of the
weekend now, values remain in the 1 to nearly 2 inch category from
time to time across the region. With the southwest flow aloft in
place from Friday through Sunday, several pieces of shortwave energy
continue to track northeast over the area during the period. Each of
the waves has the potential to bring repeated rounds of storms into
Sunday night. With this change to a extended period of more active
weather, the threat for hydro issues could increase along with
chances for stronger to severe storms. There is some consensus that
by Tuesday, quieter weather will return for a brief time. Highs
during the period from Friday into Sunday will daily remain highly
dependent on convective trends, but should range from the upper 70s
to mid 80s on average; with lows in the 60s to lower 70s with more
summerlike humidity expected through the period.
&&
.AVIATION.../For the 00Z TAFS through 00Z Wednesday evening/
Issued at 633 PM CDT Tue Jun 18 2019
Primarily showers over southwest Iowa have been slowly moving into
south central and central late this afternoon and will continue to
do so this evening. High confidence this will impact DSM and OTM
this evening and overnight and lower confidence with just VC
wording at ALO. Patchy fog development into MVFR is possible as
well over the southern terminals. Showers and MVFR ceilings will
linger over southern Iowa on Wednesday with gradual improvement
into VFR at DSM and perhaps near the end of this TAF period at
ALO.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...REV
LONG TERM...REV
AVIATION...Ansorge
Area Forecast Discussion
National Weather Service Austin/San Antonio TX
1005 PM CDT Tue Jun 18 2019
.UPDATE...
Quick update to adjust PoPs based on the current radar trends and
the newest evening high resolution models. Convection from West Texas
moved right along the Crockett/Val Verde then Sutton/Edwards County
lines before weakening. Outflow from these earlier storms is
currently moving to the southeast from Brackettville to Reagan Wells
to Leakey to Mountain Home and has sparked off a few isolated showers
and storms near Barksdale. These isolated storms should continue for
a few more hours before dissipating as the outflow continues to
outrun any convection it sparks off.
Newest high resolution guidance keeps the storms across north Texas
well to the north of the area tonight, so PoPs have been trimmed back
after midnight to just included the possibility of a few more
isolated showers/storms along the outflow west of I-35. Areas east of
I-35 should be dry overnight. There is a low chance of some patchy
fog by morning, but with a bit higher winds tonight and not as much
precipitation during the day compared to yesterday coverage should be
less than what was seen this morning. For this reason have continued
to leave mention out of the grids.
&&
.PREV DISCUSSION... /ISSUED 646 PM CDT Tue Jun 18 2019/
AVIATION...
ISOLD-SCT SHRA/TSRA currently over the Pecos Valley to the Big Bend
to Davis Mountains areas will move toward the east over the Edwards
Plateau this evening, then gradually dissipate over the Hill Country
later this evening, possibly Central Texas overnight. Have mentioned
VCSH for KDRT where the best chances are. Will monitor trends for
possible updates for TSRA at KDRT this evening and SHRA/TSRA at KAUS
overnight. For KDRT, SHRA/TSRA over the Edwards Plateau will bring
low end VFR CIGs and VRBL winds around 5 KTs, possible gusts to 25
KTs, this evening, then SE winds 5 to 10 KTs return with VFR skies
prevailing Wednesday. At KSAT/KSSF/KAUS, VFR skies prevail this
evening with S winds 5 to 10 KTs. IFR CIGs develop overnight, then
rise to MVFR as low level jet strengthens. CIGs mix out to FEW-SCT
VFR clouds with S winds 10 to 15 KTs with occasional gusts to 25 KTs
on Wednesday.
PREV DISCUSSION... /ISSUED 301 PM CDT Tue Jun 18 2019/
SHORT TERM (Tonight through Wednesday Night)...
Despite the presence of broad, mid to upper level ridging across the
southern half of Texas today, a gravity wave from overnight
convection across the Permian Basin and Low Rolling Plains allowed
for a thunderstorm complex to propagate into the Brazos Valley
earlier today. Remnants of an outflow boundary associated with these
storms were evident on visible satellite imagery along a
Mason/Dripping Springs/Giddings line early this afternoon and will be
watching for isolated late afternoon shower development along this
feature as it lingers across the region. Anvil debris slowed
modification of the post-boundary airmass earlier today (allowing for
the boundary to linger and drive farther to the south and east), but
clearing skies have allowed for temperatures behind the boundary to
spring back into the mid 80s and additional insolation should allow
for this boundary to wash out by this evening.
Farther to the west, a 50-70 knot upper level speed maxima straddling
the Big Bend was allowing for isolated to scattered showers to linger
across Val Verde County. This has produced persistent scattered
cloud debris across the southern half of the county and has limited
overall convective intensity today. With little overall change in the
pattern across the state, expect similar storm trends tonight with
some of the activity across the Davis Mountains and Big Bend making a
run for Val Verde this evening. The aforementioned stability will
likely limit how far east these storms are able to make it, but will
also be watching areas farther north tonight where a surface trough
across the Low Rolling Plains may serve as a focus for another
nocturnal thunderstorm complex that makes a run for the region.
Higher resolution guidance like the HRRR and NSSL-WRF try to keep
this complex north of the region and take it into North Texas, but
Corfidi vectors are oriented more northwesterly and indicate that
portions of Central Texas may again be clipped by a morning complex
should it hold together. (Corfidi vectors can be used to anticipate
surface based mesoscale convective systems based on the
strength/direction of the low level jet, orientation of cold pool
relative flow, as well as instability present ahead of the system.)
Have added some low rain chances (20/10 PoPs) to Central Texas for
the early morning and morning hours to account for this potential.
Otherwise, expect another warm night for the region with lows in the
70s. Have held off on including a patchy fog mention at this time
with at least a weak low level jet in place tonight, but areas east
of a Fredericksburg to Gonzales line will need to be monitored for
potential fog development.
Ridging becomes more zonal on Wednesday as a shortwave drops into
the Southern Plains from Colorado and this will help veer 850-700 MB
flow, resulting in temperatures skyrocketing to the mid 90s to low
100s across the region by Wednesday afternoon. Only modest mixing
during the afternoon hours will mean hot and humid conditions produce
heat index values in the 102 to 110 degree range and a Heat Advisory
may be needed for areas east of Interstate 35. Associated capping
from this veered low-mid level flow should limit overall rain
chances but will need to watch what appears to be a weak cold front
(or possible outflow from storms over Oklahoma tonight) sliding into
West Central Texas for possible shower or thunderstorm development.
Little relief from the heat is expected Wednesday night with lows in
the mid 70s to lower 80s.
LONG TERM (Thursday through Tuesday)...
Zonal flow aloft persists through Thursday, but becomes
southwesterly and amplifies Friday and Saturday as longwave troughing
becomes established across the western CONUS. The thermal ridge
associated with the veered low level flow appears to be the strongest
on Thursday and have maintained advertising widespread 100-105 degree
temperatures. A Heat Advisory is also possible again on Thursday. As
upper level flow becomes more southwesterly, this will help back
lower level flow, moderating high temperatures a few degrees (highs
in the mid 90s this weekend as opposed to the ground scorching 100+
during the mid- week period) and allow for isolated to scattered
thunderstorm changes to enter into the forecast as embedded
disturbances in the flow aloft translate near the region. As the
upper trough axis begins to slide east early next week, rain chances
look to translate east of the region sometime around or after
Tuesday.
&&
.PRELIMINARY POINT TEMPS/POPS...
Austin Camp Mabry 77 98 77 100 77 / 10 10 - 0 0
Austin Bergstrom Intl Airport 76 98 77 100 77 / 10 10 - 0 0
New Braunfels Muni Airport 75 99 76 101 75 / 10 10 - 0 0
Burnet Muni Airport 75 97 76 99 75 / 20 10 - 0 -
Del Rio Intl Airport 77 100 77 104 77 / 20 10 10 0 -
Georgetown Muni Airport 75 98 77 100 76 / 10 10 - 0 0
Hondo Muni Airport 76 102 77 104 76 / 10 10 - 0 -
San Marcos Muni Airport 75 99 76 101 76 / 10 10 - 0 0
La Grange - Fayette Regional 77 98 78 99 78 / 10 10 - - 0
San Antonio Intl Airport 76 100 77 102 77 / 10 10 - 0 0
Stinson Muni Airport 77 100 78 103 77 / 10 10 - 0 0
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
Aviation...04
Short-Term/Long-Term...Treadway
Area Forecast Discussion
National Weather Service Key West FL
1027 PM EDT Tue Jun 18 2019
.DISCUSSION...
Have watched two separate outflow boundaries this evening. The
first moved off the South Florida Peninsula and across the Upper
Keys early this evening, with Carysfort Reef Light gusting to 30
mph. The second outflow originated from convection near Varadero,
Cuba, and raced north across the Straits. It appeared to weaken
just before reaching the islands.
The 00z KEY sounding showed some convective inhibition
developing, but it still appears breakable given sufficient low-
level focus. The PW value still exceeded 2" which indicated a
tropically moist air mass.
The question is how much convective activity will flare up during
the overnight and early morning hours along these leftover
boundaries. The last 2 runs of the experimental Caribbean HRRR
have both picked up on the Cuban-borne outflow. They then focus
new convection overnight somewhere between Key West and the Dry
Tortugas, with the possibility of showers and thunderstorms
brushing the Lower Keys in the hours around sunrise. In reality,
showers could develop most anywhere.
By mid-day Wed, the strengthening of the subtropical ridge over
South Florida and building 500 mb heights over the Keys will start
a larger-scale drying of the mid-level air mass. The coverage of
showers and thunderstorms should diminish substantially and remain
below climatology for the rest of this week and this weekend.
&&
.MARINE...
A subtropical surface ridge will strengthen over South Florida and
persist through this weekend. As a result, gentle to moderate east-
southeast breezes will prevail.
&&
.AVIATION...
VFR conditions will prevail at both terminals. Previous showers and
thunderstorms over the Florida peninsula have left an inactive
boundary just north of the Lower and Middle Keys. Meanwhile, another
boundary is moving north across the Straits of Florida and will
likely interact with the northern boundary creating potential for at
least VCSH at either or both terminals before midnight tonight.
Temporary MVFR ceilings may need to be part of an amendment. Gusts
near 25 knots are possible should showers or even thunderstorms
become more certain to affect the terminals. Pesky mid-level
ceilings between FL160 and FL220 will continue throughout the
period. Winds will remain southeast to south near 10 knots, outside
of any possible convective activity.
&&
.KEY WATCHES/WARNINGS/ADVISORIES...
FL...None.
GM...None.
&&
$$
Public/Marine/Fire...Haner
Aviation/Nowcasts....Chesser
Data Collection......SD
Visit us on the web at weather.gov/key
Follow us on Facebook and Twitter at:
www.facebook.com/nwskeywest
www.twitter.com/nwskeywest
Area Forecast Discussion
National Weather Service Marquette MI
752 PM EDT Tue Jun 18 2019
.SHORT TERM...(This evening through Wednesday)
Issued at 452 PM EDT TUE JUN 18 2019
Water vapor imagery and RAP analysis show a mid-level low over
Quebec with troffing extending sw into the Northern Plains and
northern Great Lakes. Within the trof, shortwave has moved e from MN
into western Upper MI today with associated cold front over central
Upper MI. Ahead of this feature, there has been enough daytime
heating to boost sbcape to 500-1000j/kg into s central Upper MI per
latest SPC mesoanalysis. As a result, shra and isold tsra have
developed. With deep layer shear of 40-50kt, a strong storm or two
will be possible for the next hr or so. To the w, there has been
nothing more than a few sprinkles today.
Ongoing shra/isold tsra will diminish/end over the next several hrs
as shortwave/cold front continue moving e. There are some shra back
to the w over ne MN, but with these shra largely a result of daytime
heating, these shra will not be able to move out across Lake
Superior. Thus, don`t expect any additional shra after the ongoing
activity over the e half of the fcst area ends. Vis satellite
imagery showed a few patches of fog on Lake Superior earlier today,
but not really seeing much now, though clouds are obscuring the view
over portions of the lake. If there are some fog patches out there
yet, light n to nw winds into the n central/ne fcst area would
result in fog/stratus developing in those areas during the night.
Will be something to monitor. Even without that, there could be some
patchy fog development anywhere tonight, especially where rain
occurred today. However, with fcst soundings showing relatively
moist air mass thru a fairly deep sfc based layer, not sure there
will be much. Expect min temps mostly in the 40s across the board.
A shortwave now over ND will move across the area on Wed. Wave looks
fairly well-defined now, but is not producing much in the way of
shra. With fcst soundings suggesting a cap here on Wed, not
expecting any -shra development. Depending on low cloud development
tonight, there may be quite a bit of cloudiness in the morning, but
trend will be for increasing sun as moisture mixes out Wed. Temps
will respond into the lower 70s in the interior. Onshore winds near
Lake Supeiror will keep conditions cool along the lake, especially e
of Marquette. Temps not likely to get above the 50s lakeside.
.LONG TERM...(Wednesday night through Tuesday)
Issued at 331 PM EDT TUE JUN 18 2019
Through the end of the work week, the large scale upper air pattern
will continue to consist of a closed low over Quebec and another
over southern British Columbia that will gradually shift eastward.
This will lead to western CONUS troughing and central CONUS zonal
flow amplifying into ridging over our region Thursday night through
Friday. An impulse ahead of the main trough will bring scattered
showers and perhaps a few thunderstorms to the region over the
weekend, though better chances for heavier rain currently look to
stay to our south in WI. The trough will be slow to progress
eastward and is currently progged to cross Upper Michigan sometime
Monday, with ample uncertainty remaining in the exact timing and
strength of forcing as it crosses. In general, trends have been
towards a slower progression through this weekend into early next
week. Upper level flow becomes more northwesterly into midweek which
should lead to mostly dry conditions once again, but shortwave
activity may bring additional scattered shower/isolated t-storm
chances.
As a Hudson Bay high extends sfc ridging through the western Great
Lakes Thursday into Friday, dry weather will prevail with seasonal
temperatures, though remaining a tad cooler than normal near Lake
Superior. Some chances for fog, mainly over the west and western
Lake Superior are possible Wednesday night into early Thursday.
Warm, moist air will trickle in through Friday with just a slight
chance for a shower over the west late. Then moisture transport looks
to increase in earnest Saturday as low level flow becomes more
southerly. Mostly cloudy skies will keep temperatures a tad cooler
Saturday as rain chances increase. Thunderstorms will be possible in
the Saturday afternoon-Sunday night time frame. Uncertainty remains
through this time with some indications of CAPE exceeding 2500-3000
J/kg Sunday afternoon over central Upper Michigan (GFS) and other
models bringing little if any instability into the region (00Z EC,
12Z CMC-NH). Regardless, PWAT values look to rise to near 1.5 inches
through much of the weekend, and heavy rainfall will be possible.
Chances for stronger storms will have to be monitored as the
mesoscale environment becomes more clear.
On the whole, better chances for widespread precipitation will
probably come after 00Z Sunday as better WAA moves in and ridging
exits further east, but this is not reflected in the NBM POPs.
GFS/ECMWF are now locked in pretty well on main trough passage
coming Monday afternoon with widespread rain. Ensembles seem to
support this idea, but given the anticendent blocking pattern there
does remain some wiggle room in timing and ensemble plumes indicate
a large spread in intensity/QPF. At this time, thunder chances are
low with this, but plenty of time for that to change as well. After
the trough finally passes, generally dry conditions would be
expected into the middle of next week with somewhat cooler temps
expected to briefly impact the region.
&&
.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 752 PM EDT TUE JUN 18 2019
This evening will continue with VFR conditions at all terminals,
however overnight, there is potential of stratus and patchy fog
developing. Confidence has increased, but is still low with this
forecast issuance. Expect some MVFR and IVR cigs at SAW while CMX
will border VFR/MVFR cigs and IWD will drop into MVFR cigs
overnight. Although SAW is expected to fall into IFR conditions,
there is a possibility to fall into LIFR conditions briefly. Should
fog develop and linger, expect mainly IFR vsbys with an slight
chance for LIFR vsbys. Conditions at all terminals are expected to
improve to VFR a few hours after sunrise.
&&
.MARINE...(For the 4 PM Lake Superior forecast issuance)
Issued at 452 PM EDT TUE JUN 18 2019
Sfc high pres will prevail across Lake Superior thru Thu, keeping
winds under 20kt, but for much of Lake Superior, winds will be under
15kt. Winds will increase Fri thru the weekend as a cold front
approaches. Wouldn`t be surprised to see winds in the 15-25kt range
at times.
There may be some patchy fog on Lake Superior tonight into Wed
night, but if it doesn`t develop tonight, fog won`t be an issue Wed
or Wed night.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
None.
Lake Michigan...
None.
&&
$$
SHORT TERM...Rolfson
LONG TERM...KCW
AVIATION...JAW
MARINE...Rolfson