Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 07/23/18
Area Forecast Discussion
National Weather Service La Crosse WI
607 PM CDT Sun Jul 22 2018
.SHORT TERM...(Tonight and Monday)
Issued at 230 PM CDT Sun Jul 22 2018
Weak instability along with a weak frontogenetic boundary/upper
level energy could still fire a few showers across mainly western WI
into the early evening. Otherwise, anticipate decreasing clouds with
perhaps some fog west of the Mississippi River.
Weak upper level ridge quickly shifts east on Monday while a
shortwave trough tracks across northern parts of the region. An
associated cold front will also shift east across the area Monday,
showing signs of weakening as it does. Weak instability ahead of the
front, with approx 1500-2000 J/kg of SBCAPE in the NAM and GFS. No
shear to speak of. Should be enough in that mix though to spark
bkn/sct line of showers/storms along the front for the afternoon,
potentially into the evening. Will keep chance pops for the moment.
.LONG TERM...(Monday night through Sunday)
Issued at 100 PM CDT Sun Jul 22 2018
The main forecast concerns are chances of precipitation through next
Sunday. Models are in good overall agreement but there are some
timing differences between the models through the long term.
A slow moving 500 hpa short wave moving across Manitoba into far
western Ontario will push a weak cold front into central Wisconsin
Monday night. The better forcing is to the north of the Canadian
border with this storm system and moisture is limited so no
precipitation is expected as this storm system exits into central
Wisconsin by 06 UTC on Tuesday.
The low passing to our north Monday night will play a key role in
our weather for the remainder of the week as shortwave energy
rotating around this low located in the vicinity of the Hudson Bay
will dig a trough over the Great Lakes region. This will bring
cooler air into the region after Wednesday. This will also bring
chances of showers and thunderstorms Wednesday night into Thursday,
Friday, and Saturday through Sunday.
The first shortwave will arrive Wednesday during peak heating and
push a strong cold front across southeast Minnesota, northeast Iowa,
and western Wisconsin during the afternoon and evening hours. Models
are forecasting CAPE values of 1000 to 1500 J/kg and 0 to 6 km shear
of around 30 to 40 knots Wednesday afternoon and evening so severe
weather is a possiblity. There are some timing differences between
the GFS and ECMWF with the ECMWF being about 6 hours slower than the
GFS with the timing of this first shortwave. This could have an
effect on severe weather potential for Wednesday.
In the wake of this first shortwave, a deep and active northwest
flow sets up over the Upper Midwest. There are timing, strength, and
numbers of shortwave differences between the GFS, Canadian and ECMWF
through next Sunday but all three are indicating several chances of
precipitation through next Sunday. All three models are indicating a
stronger shortwave moving through the region on Sunday.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 607 PM CDT Sun Jul 22 2018
Another day with wrap around clouds and a few showers as the
region remains in the cyclonic flow around the large upper level
low over southeast Michigan. These clouds and showers are expected
to diminish this evening with the loss of heating and once again
be focused closer to the upper level low. This will let the weak
ridge of high pressure at the surface be the dominant feature
overnight allowing for light winds and clear skies. This should
allow some fog to form and possibly produce some MVFR visibilities
at KRST. Will not include and fog for KLSE as the 23.21Z RAP
forecast sounding does not show surface saturation occurring. A
weak cold front will approach from the northwest Monday afternoon
and bring an increase in clouds with a VFR ceiling expected for
KRST. Some showers/storms possible as the front comes in but lots
of uncertainty on the coverage. The front will be undergoing
frontolysis and the main short wave trough will be well to the
north of the area. Very weak moisture convergence along the front
as the surface winds switch to the northwest well ahead of the
front. Confidence not high enough to include a VCSH at KRST at
this point.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
IA...None.
&&
$$
SHORT TERM...Rieck
LONG TERM....Cousins
AVIATION...04
Area Forecast Discussion
National Weather Service Bismarck ND
1008 PM CDT Sun Jul 22 2018
.UPDATE...
Issued at 1003 PM CDT Sun Jul 22 2018
Quick update to add some patchy fog for the JRV. Front has just
moved through JMS but with the setting sun we have also lost the
winds. Also had a quick 0.20 in of rain late this afternoon. Think
the fog will be short lived and can see a secondary boundary on
radar approaching the area within the next hour or so. Could see
similar conditions southward across the southern JRV. Added fog
for a couple hours.
UPDATE Issued at 926 PM CDT Sun Jul 22 2018
For the evening update we have removed all mention of severe for
the remainder of the night. Only an hour or so left of possible
convection over Dickey and eastern Lamoure counties. Otherwise
clearing over the JRV, and mostly clear elsewhere and much drier.
Dewpoints are already in the upper 30s and lower 40s over the far
southwest, and will continue to drop over central ND. With the
lowering dewpoints, mostly clear skies and diminishing winds, we
lowered temperatures most areas.
UPDATE Issued at 546 PM CDT Sun Jul 22 2018
Update mainly to adjust pops based on latest radar and
interpolation through the early evening. Abundant CAPE and shear
remain in place over the James River Valley. However, convection
is having a hard time maintaining itself. RAP soundings show
perhaps a little bit of a cap ahead of the front and pre-frontal
trough, then wind profiles become less favorable with the passage
of each. There has been some rapid development in the past 30
minutes. It looks like the southern James River Valley would be
the most likely area for anything severe yet this afternoon or
early evening.
&&
.SHORT TERM...(This afternoon through Monday)
Issued at 221 PM CDT Sun Jul 22 2018
Complicated forecast this afternoon, as an area of stratus has
filled in across central ND, and now over the James River Valley.
Elevated convection continues over the Turtle Mountains, but that
will be exiting this region in the next couple hours.
In defining the cold front,purely from a density gradient/dewpoint
change, the front still resides in far western ND, separating
dewpoints in the upper 30s in eastern Montana, to lower 60s in
western ND. A surface trough ahead of the main cold front has just
cleared a Minot to Bismarck line as winds have shifted to the
northwest. Main pressure rise bubble in close proximity to the
density gradient in western ND, thus more stable air resides
farther west this afternoon. The area of stratus is slowly shifting
east and the question remains if we will see the main development
of severe weather on the back edge of the stratus or not. There
will be a narrow window from the more stable air pressing in from
western ND and the more unstable airmass right behind the
stratus. CAMS want to develop the showers/thunderstorms within
the stratus region, but not sure that will happen at this time. So
severe weather and coverage remains problematic at this time.
Will continue with the previous thinking and maintain severe
weather within the slight risk region and adjust as necessary this
afternoon and evening. The cold front will clear the James River
Valley early tonight, with a mostly sunny and drier day Monday.
Highs will be in the upper 70s.
.LONG TERM...(Monday night through Saturday)
Issued at 221 PM CDT Sun Jul 22 2018
Upper low circulating over Manitoba resulting in northwest flow
and cooler temperatures. Embedded within the flow will be another
shortwave trough and associated inverted surface trough slated
for late Tuesday afternoon through Tuesday night. SPC has a
marginal threat for severe weather, but this could be upgraded to
a slight risk across portions of southern ND where deep layer
shear between 50kt and 60kt interact with weak instability.
Ahead of this shortwave and surface front, temperatures will warm
into the lower to mid 80s across southern North Dakota. Behind it
Wednesday through Friday, temperatures will cool into the mid and
upper 70s for daytime highs, and much less humid.Overnight lows in
the upper 40s to lower 50s can also be expected. For the most
part, should see dry weather under the northwest flow Wedneday
through Friday. Slight chances of thunderstorms return Saturday,
but coverage right now looks meager.
&&
.AVIATION...(For the 06Z TAFS through 06Z Monday night)
Issued at 1003 PM CDT Sun Jul 22 2018
Added a mention of fog for JMS through around 05 UTC. Otherwise
VFR conditions expected through the forecast period.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...TWH
SHORT TERM...KS
LONG TERM...KS
AVIATION...TWH
Area Forecast Discussion...UPDATED
National Weather Service Brownsville TX
625 PM CDT Sun Jul 22 2018
.DISCUSSION...Updated for latest aviation discussion below.
&&
.AVIATION...High confidence that VFR will prevail for the next 24
hours. Could briefly see cumulus field begin to develop around
13-15Z on Monday with bases at MVFR levels (as happened Sunday
morning for 30 minutes or less), but these should quickly mix
higher, even if a ceiling does form. A batch of cirrus can be
seen outside visually and upstream to the NE on satellite
imagery. RAP BUFKIT forecast soundings indicate this will
continue, so have included in TAF. SSE winds stay up at around
10KT overnight, before becoming moderately breezy again by mid-
morning.
&&
.PREV DISCUSSION... /issued 344 PM CDT Sun Jul 22 2018/
..Heat Advisory may be warranted Monday...
SHORT TERM (Now through Monday night): Models have not wavered
much in the last 12-24 hours and the hottest temperatures of the
year are on tap for Monday. With the center of the expansive
anomalously strong ridge centered over New Mexico, heights,
thicknesses and 850mb temps reach their respective peaks. Model
guidance indicates ambient tempeatures between 105 and 110
degrees along and west of highway 281/69C. Just the ambient
temperatures approaching 110 degrees should warrant a heat
advisory with the main concern that dew points do not mix out
sufficiently to keep heat indices below the 111 degree criterion.
Over the eastern counties and closer to the coast the concern is
dew points/RH values remain high enough with temperatures nearing
or exceeding 100 degrees for at least a few hours to push the heat
indices above the threshold. In any case, will let overnight crew
have one more model run to view before pushing the trigger for a
possible area-wide Heat Advisory. Clear skies and lighter winds
will allow for temperatures to slowly drop off with mid to upper
70s overnight. Monday night will be a few degrees warmer with
daytime highs maxing out.
LONG TERM (Tuesday through Sunday): The 500mb high will remain
very strong through mid week with model consensus showing heights
nearing 600dam. Fortunately, the ridge axis will begin to shift
westward into the Desert Southwest as a deep trough digs into the
Great Lakes and Mid Atlantic regions. This will shift the mid-
level flow to the north and northeast across Deep South Texas with
1000 to 500mb thickness also decreasing towards the end of the
week. This will allow a weakness in the flow and perhaps an
actual chance of precipitation again Wednesday into Thursday.
Models differ quite a bit with the GFS going the highest at 20 to
30% along the coast and the ECMWF staying at around 10%. At this
point, have kept PoPs at 10% inland and 20% offshore where the
better moisture and lift will be.
Despite lowering mid-level heights, we are in the climatological
peak of high temperatures, so it`s going to be hot each day.
However, highs will be less uncomfortable and range from the mid
to upper 90s in the Lower Valley to around 105F in the Upper
Valley. Heat Indices will range from 105 to 110 and possibly
approach the Heat Advisory criterion at times.
MARINE (Now through Monday night): Surface high pressure stretching
across the Gulf of Mexico and lower pressure in the Sierra Madre
mountains will maintain south to southeast winds off the lower Texas
coast. Light to moderate winds persist through Monday night with
slightly stronger winds over the Laguna Madre Bay Monday
afternoon.
Tuesday through Friday: A pretty mild PGF will prevail throughout
much of the week over the western Gulf and the lower TX
coastline. This will maintain pretty benign wind and sea activity
across the Laguna Madre and the lower TX Gulf Waters. No SCA
conditions expected through late Thurs.
FIRE WEATHER...Fire weather conditions are still a concern Monday
with the extreme heat. Humidity levels will be on the threshold
area-wide but winds and fuel dryness remain limiting factors. At
max mixing relative humidity levels look to be in the 15-30
percent range along and west of 281/69C and 30-45 percent east to
the coast. Strongest winds are likely over the east with much
lighter winds expected west. Currently, fire conditions remain
just below elevated criteria but with the extreme temperatures and
some afternoon gustiness it is still suggested to refrain from
any burning or working with any equipment that might ignite a
spark.
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...None.
GM...None.
&&
$$
This product is also available on the web at:
HTTP://WEATHER.GOV/RGV
53/55
Area Forecast Discussion
National Weather Service Columbia SC
805 PM EDT Sun Jul 22 2018
.SYNOPSIS...
A deep upper trough will remain over the E CONUS through late
next week. This will result in increasing moisture and chances
of showers and thunderstorms through next weekend.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
Regional radar this evening shows convection mainly confined to the
northern portion of the forecast area. DCAPE values remain elevated
at over 1000 J/kg, so an isolated damaging wind threat remains
possible, but overall severe threat is low. Will continue to monitor
for a heavy rain threat especially with storms that are training. An
upper level low will continue to drop southward over the
Southeastern CONUS overnight with a weak surface boundary draped
across the area. High resolution models show activity diminishing
across the area tonight with only isolated showers and storms
overnight, so reduced pops a bit after 06Z. Overnight lows are
forecast in the lower 70s.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY NIGHT/...
On Monday through Tuesday the models are consistent with the
closed upper low drifting southward into the Southeast by Monday
night/early Tuesday. Then they begin to gradually lift the
closed low northward slowly through Tuesday night into eastern
TN. This will produce a deep southerly flow across the area. PW
values will increase to around 2.0 inches across much of the
Midlands and CSRA. The combination of cyclonic 500mb flow,
daytime heating and abundant moisture is expected to result in
widespread showers and thunderstorms by late afternoon into the
evening hours with the highest chances in the Pee Dee and
central Midlands areas. Temperatures will be near to slightly
below normal through the period with daytime highs in the upper
80s to near 90 along with overnight lows in the low/mid 70s.
Rain chances will remain in the likely/good chance category
through the period. WPC has the area in a slight chance for
excessive rainfall on Monday, then focuses the NC/Pee Dee of SC
for Tuesday.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
Little change in forecast thinking for the extended periods.
The upper low to the west of the forecast area will move very
slowly northward Wednesday. The ECMWF is faster with the low
lifting northeast and the GFS is quite a bit slower. Models due
show abundant moisture with deep southernly flow on Wednesday
with PW values from 2 - 2.25 inches. Once again the possibility
of locally heavy rainfall with afternoon/evening showers and
thunderstorms. Will continue with likely pops for Wednesday.
By later in the week all of the models show the upper low
weakening and becoming sheared northeastward as an upper trough
moves into the Great Lakes region. This may provide slightly
lower chances of rain Thursday into Friday but still expect
diurnally induced scattered convection each day. Temperatures
during this period will be tempered by clouds and precipitation
with highs generally in the lower 90s and lows in the low to mid
70s.
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
VFR conditions for most of the TAF period although some stratus
and fog possible mainly at AGS/OGB toward morning.
Upper level trough axis to the west of the area. A surface
trough is located across the area. Shower and thunderstorms
early this evening focused near the surface trough north of the
terminals and west of the region. Based on latest radar trends,
a few showers and thunderstorms may move into the AGS/DNL
terminal areas this evening but confidence low and continued
VCSH at the moment. Confidence a little higher that showers will
not impact other terminals. Expect scattered cumulus and higher
clouds through the evening. The latest HRRR suggest some stratus
may move into the southeast Midlands near OGB toward morning.
Patchy MVFR fog possible as well as suggested by Lamp as there
should be an increase in low-level moisture around daybreak with
winds becoming southeast. Broken cumulus expected Monday with
scattered showers and a few thunderstorms mainly in the
afternoon although stronger focus may be in the coastal plain
and to the west associated with upper level low. Light southwest
winds tonight shifting to southeast 5 to 10 knots Monday.
EXTENDED AVIATION OUTLOOK...Increasing confidence in scattered
to numerous mainly afternoon and evening thunderstorms each day
along with late night/early morning fog/stratus possible.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
GA...None.
SC...None.
&&
$$
SYNOPSIS...99
NEAR TERM...99
SHORT TERM...99
LONG TERM...99
AVIATION...99
Area Forecast Discussion
National Weather Service Cheyenne WY
934 PM MDT Sun Jul 22 2018
.UPDATE...
Issued at 922 PM MDT Sun Jul 22 2018
We have updated PoPs for the remainder of the evening/overnight to
account for recent radar trends. A fairly persistent band of light
to moderate rain has evolved from southern Albany county east-ward
into southern Laramie county, but very little if any lightning has
been observed over the last hour or two. We also expanded low PoPs
northward through the night into early Monday based on HRRR output
over the last few runs. Modest low-level jet energy, combined with
elevated instability & the passage of a weak disturbance should be
sufficient for at least isolated showers through 15z. We also have
included mention of patchy fog from the I-80 summit, eastward into
Cheyenne between 9-15z w/ ample surface moisture, and weak low-lvl
upslope flow during that time.
&&
.SHORT TERM...(This evening through Monday)
Issued at 222 PM MDT Sun Jul 22 2018
Main impact focus today will be the scattered showers and a few
thunderstorms across southern portions of WY and the Panhandle of
Nebraska. A few of these showers and storms could be close to the
Badger Creek burn scar that could result in very localized but
still impactful flash flooding if intense enough rainfall rates
moved directly over the vulnerable soils. A localized flash flood
watch has been issued for that area from 4pm through 10pm.
Additional high terrain and adjacent showers and storms are likely
again Monday but coverage will be less then today.
Latest water vapor GOES16 channels depict a passing shortwave
trough across southern Canada into Montana with deeper west to
southwest flow aloft. The combination of this feature and deep
convection farther north overnight is shifting a cool front
southward this afternoon. North winds are being observed across
the region as lower-level weak dry air advection occurs behind the
front. Deeper boundary layer moisture still exists across the NE
Panhandle were negative theta-e advection has yet to take place.
The combination of the divergent flow aloft and residual mid-level
monsoonal moisture will allow for showers and some thunderstorms
to develop overtop of the 4kft thick weak dry-air advection
layer. The magnitude of the dry air does not appear to be
sufficient enough to restrict the mid and upper level moist
profiles from producing heavy rainfall. Some activity could be
locally moderate to heavy but strong storm potential will be
limited to the NE Panhandle. As residual troughing and mid to
upper level support linger overnight, rain shower chances will
persist through the early morning hours across southern WY.
For Monday, another round of showers and storms will occur over
the higher terrain due to instability but overall coverage will be
less as slightly greater ridge influence occurs along with decreased
shortwave troughing divergent flow aloft. Will need to monitor
for the Badger Creek Burn scar again however, as this area could
be in a more favorable area for localized but moderate rainfall
rates.
.LONG TERM...(Tuesday through Saturday)
Issued at 325 AM MDT Sun Jul 22 2018
West-northwest flow aloft will prevail through the week between
a upper high over the southwest CONUS and active storm track
across the northern tier CONUS.
Tuesday will be warmer as the upper ridge tries to build north
into southern WY and western NE. A strong cold front for late July
is still progged to plunge south through the CWA Tuesday evening.
Ahead of the front, stronger mid-level west-northwest flow
combined with steep lapse rates and MUCAPEs exceeding 2500 j/kg
may lead to isolated strong to severe convection over northern and
eastern parts of the NE Panhandle during the late afternoon and
early evening.
After highs in the low-mid 90s Tuesday, Wednesday will be at least
10 degrees cooler, and another 5 degrees cooler Thursday. The
front will stall along the Front Range Wednesday, with scattered
showers and thunderstorms from the afternoon through late night.
The proximity of the stalled front, moist easterly upslope, and
several embedded shortwaves will enhance convective activity,
mainly during the afternoon and evening Thursday through Saturday.
Locally heavy rain, gusty winds and small hail will accompany the
stronger thunderstorms. Temperatures warm slightly Friday and
Saturday, but will remain below seasonal averages.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 515 PM MDT Sun Jul 22 2018
Much of the stratus deck that had lingered across the region today
is finally starting to lift with a bit remaining across the
northern NE Panhandle sites. Some convection has initiated across
the border in Colorado and light showers across the NW portion of
the forecast area. Showers and thunderstorms are still expected
this evening but will taper off after 10 PM MDT for most.
Otherwise post-storm conditions will see winds dying down and a
low stratus deck forming overnight.
&&
.FIRE WEATHER...
Issued at 222 PM MDT Sun Jul 22 2018
Main fire weather concern in the immediate short term and for the
Badger Creek Burn Scar area will be localized areas of moderate
to heavy rainfall that could lead to localized flash flooding
and debris flows. Lightning near and over the burn scar will
also be a concern from 3pm through 9 to 10pm this evening. The
flash flood watch is in effect from 4pm through 10pm. While heavy
rain may not fall directly on the burn scar, localized pockets of
moderate rain will certainly be nearby through the afternoon and
evening.
For the rest of the region, fire weather concerns are minimal as
high monsoonal moisture has reached much of SE WY and W NE.
Humidity values remain high this afternoon with areas ranging from
the 50 percentiles across the High Plains to the 30 and mid 20
percentiles in the far west and higher terrain locations. Minimal
fire weather concerns expected through the week with several rounds
of wetting rains likely Tuesday through next Saturday. Monday will
also feature isolated showers/storms over the mountains but
coverage will be more limited then the upcoming week.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...Flash Flood Watch until 10 PM MDT this evening for WYZ114.
NE...None.
&&
$$
UPDATE...CLH
SHORT TERM...JSA
LONG TERM...MAJ
AVIATION...WM
FIRE WEATHER...JSA
Area Forecast Discussion...UPDATED
National Weather Service Austin/San Antonio TX
629 PM CDT Sun Jul 22 2018
.AVIATION.../00Z TAFS/
Currently looking for VFR conditions to prevail through this forecast
period. Guidance is suggesting some MVFR conditions to the east of
I-35. Low confidence at this time that MVFR cigs would make it to the
I-35 terminals and decided to leave out of the forecast.
Southeasterly winds near 10 knots will become southerly 5-8 knots
after 07Z then back to S/SE near 10 knots after 16Z. KDRT will see SE
winds 10-15 knots becoming easterly at 5-10 knots after 02Z then
back to SE after 16Z.
&&
.PREV DISCUSSION... /ISSUED 310 PM CDT Sun Jul 22 2018/
SHORT TERM (Tonight through Monday Night)...
Late morning surface winds will mostly from the southwest leading the
less cloud cover and temps warming faster than yesterday by about 2
or 3 degrees. This should lead to todays highs being more consistent
with those of Friday after a many temps trended down a degree or two
Saturday. Dry air seen from composite layer precipitable water
satellite product early this afternoon should send temps soaring over
the northern Hill Country and another 108 degree day is expected at
Llano. The sharper anticyclonic rotation over NW TX/SW OK is drifting
SW and will be over our northern CWA border for Monday, yielding
possibly the hottest day of the year and possible new records for all
4 climate stations as shown below. 850 mb temps will approach 30
Celsius over the northern Hill County and raw model data suggests
that a few areas could reach the 110 mark. While the forecast highs
for tomorrow should exceed those of today, no new threat areas were
identified for possible upgrades in the NPW product for Excessive
Heat Warning and Heat Advisory. Mid level moisture begins to increase
over Central Texas Monday evening, but under the sharpest part of the
anticyclonic flow in the mid levels, very little convective activity
is developed by CAMS models in the CWA with only some brief
activity suggested over North Central TX. Will need to watch closely
as the 36 hour HRRR shows pwat values reach around 1.75 toward 00Z
around Llano. Areas near the northern border of the CWA could need to
watch for strong outflow winds early Monday evening.
LONG TERM (Tuesday through Sunday)...
Mid level moisture continues to spill south across TX and a better
chance for elevated convection is suggested for Tuesday. The early
morning arrival of this pattern could work out good for the area with
the lower convective temps possibly developing a less severe looking
inverted-v profile. Still afternoon temps near highway 281/I-35
corridors could approach 100 degrees which could support strong
downdrafts. Areas west of 281 could see the stronger storm downdrafts
Tuesday. With a weakening front moving with this bubble of mid level
moisture chances are, the outflows will occur once, and then
stabilize the area in its wake. This means that while convection
could impact most of the area with wind, the chance of precip is more
likely to be isolated. Remnant convection could develop in the
convergent low level winds mainly south of I-10 Wednesday before
upper stability regains control.
With little moisture expected from convection, am shifting extended
period high temps for Thurs-Sat to be more of a true split between
the hotter ECM and the "cooler" GFS guidances. Further shifts toward
the hotter ECM may be needed should the frontal wind shifts and
thunderstorm outflows turn out weaker than projected. Another
weakness in the ridge over North TX could bring about additional
slight chance PoPs next Sunday.
CLIMATE...
Record Daily High Temperatures vs. Forecasted Highs
7/22 7/23
SUN MON
--------------------------
REC/FCST REC/FCST
AUS 102/103 103/106
ATT 104/104 104/107
DRT 105/105 105/109
SAT 102/102 103/103
--------------------------
&&
.PRELIMINARY POINT TEMPS/POPS...
Austin Camp Mabry 78 107 79 99 78 / 0 0 10 20 20
Austin Bergstrom Intl Airport 76 106 78 99 76 / 0 0 10 20 20
New Braunfels Muni Airport 75 105 77 100 76 / 0 0 - 20 20
Burnet Muni Airport 77 107 78 99 76 / 0 0 10 20 20
Del Rio Intl Airport 78 109 81 107 80 / 0 0 0 10 20
Georgetown Muni Airport 77 108 77 99 76 / 0 0 20 20 20
Hondo Muni Airport 74 107 75 103 76 / 0 0 0 20 20
San Marcos Muni Airport 75 105 77 99 76 / 0 0 10 20 20
La Grange - Fayette Regional 76 104 78 97 77 / 0 0 10 20 20
San Antonio Intl Airport 77 103 79 99 77 / 0 0 0 20 20
Stinson Muni Airport 76 106 78 102 78 / 0 0 0 20 20
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
Heat Advisory until 7 PM CDT Monday for Atascosa-Bandera-Bexar-
Blanco-Caldwell-Comal-De Witt-Edwards-Fayette-Frio-Gillespie-
Gonzales-Guadalupe-Hays-Karnes-Kendall-Kerr-Lavaca-Medina-Real-
Uvalde-Wilson.
Excessive Heat Warning until 7 PM CDT Monday for Bastrop-Burnet-Lee-
Llano-Travis-Williamson.
&&
$$
Mesoscale/Aviation...10
Synoptic/Grids...04
Public Service/Data Collection...YB
Area Forecast Discussion
National Weather Service Goodland KS
556 PM MDT Sun Jul 22 2018
.SHORT TERM...(This afternoon through Monday night)
Issued at 215 PM MDT Sun Jul 22 2018
Overview: The Tri-State area remains situated on the N/NE
periphery of an upper level ridge (centered invof New Mexico) at
the southern fringe of W-NW flow aloft. Forecast considerations
and expectations are essentially the same as yesterday.
Today-Tonight: Small amplitude perturbations on/near the
tropopause (150-175 mb level) will continue to round the northern
periphery of the ridge from the Desert SW/4-Corners region into
portions of the Rockies and High Plains this afternoon through
tonight -- though the influence of these high altitude waves
cannot be ascertained with much confidence -- and mid-level
features (e.g. MCVs) generated by persistent upstream convection
are more likely to influence convective evolution. Low-level
forcing will remain confined to shallow convergence invof a weak
SFC-H85 trough in the lee of the Rockies. 18Z HRRR and 12Z NAM
NEST simulated reflectivity forecasts suggest a familiar scenario
in which scattered upstream convection grows upscale into loosely
organized clusters that slowly propagate E/SE into eastern CO and
far western KS this evening (00-08Z). Effective deep-layer shear
on the order of 25-30 knots, moderate MLCAPE (1000-2000 J/kg) and
weak forcing suggest organization will primarily be multicellular
in nature. A few storms will be capable of producing brief/sporadic
downbursts in eastern CO between 6-10 pm MDT. Locally heavy
rainfall and isolated flash flooding will certainly remain
possible (primarily in eastern CO) given weak steering flow
and above normal PWAT values (1.2" to 1.4"). Expect convection to
wane by midnight -- though there is a slim chance that upstream
convection in SD/NE may propagate southward into portions of
north-central and northwest KS between 08-15Z Monday morning.
Monday-Monday night: There will be relatively little change in
the synoptic pattern, however, with ongoing convection possible
(perhaps likely) over and upstream of the Tri-State area Monday
morning, confidence remains very low w/regard to convective
evolution Monday aft/eve into Monday night.
.LONG TERM...(Tuesday through Sunday)
Issued at 116 PM MDT Sun Jul 22 2018
Upper high pressure remains centered over the Four Corners region on
Tuesday with ridging across the western half of the country. To the
east, a trough stretches over the eastern CONUS, placing the High
Plains under northwest flow aloft. Meanwhile, an upper closed low
spins over south central Canada. Throughout the day, surface high
pressure slides east of the High Plains, allowing moisture to filter
back into the area. This enables thunderstorm chances to return to
the forecast Tuesday night as a shortwave passes through.
A cold front enters the High Plains midweek and stalls, providing a
focus for storm development. As the week progresses, the upper low
in Canada pushes southeast into the Upper Midwest and ridging
retrogrades towards the west coast. Northwest flow prevails through
the end of the weekend, and multiple disturbances generate shower
and thunderstorm chances throughout the remainder of the long term
period.
Overall, wet and cooler conditions are anticipated with ample
moisture in place. Will definitely need to keep an eye on the
potential for heavy rainfall during this timeframe. High
temperatures rise from the 80s on Tuesday to the upper 80s/low 90s
on Wednesday before falling into the upper 70s/low 80s on Thursday
and Friday. The weekend looks a tad warmer with highs in the 80s
across the region. Low temperatures range from the upper 50s to mid
60s throughout the period.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 529 PM MDT Sun Jul 22 2018
VFR conditions are expected through the 00Z TAF period at GLD.
Isolated thunderstorms at GLD after 02Z will become more numerous
between 04Z-06Z. Thunderstorms will decrease in coverage with a
few storms persisting through the early morning hours. Light winds
are expected to turn to the north and become gusty after 18Z.
VFR conditions are expected through the 00Z TAF period at MCK with
isolated storm possible after 04Z through the early morning hours
on Monday. Light winds are expected to turn to the north and
become gusty after 15Z.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...VINCENT
LONG TERM...JBH
AVIATION...LOCKHART
Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
1013 PM EDT Sun Jul 22 2018
.SYNOPSIS...
A broad and slow moving low pressure system will drop from the
Ohio Valley into the Southeast by Monday. This low will continue
to influence the Mid Atlantic during the early part of the
week.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
Deep southerly flow remains across the region this evening as
upper low slowly retreats westward. The air mass is
characterized by plentiful and increasing moisture (Precipitable
water values forecast to rise above 2" overnight). MLCAPE
ranges from about 500-1500 J/KG from NW-SE this evening with
MUCAPE values from 1000-2000 J/KG, and this is progged to be
maintained through the night. Isolated to scattered
showers/thunderstorms have been moving across the region from
south to north through the afternoon and evening and this will
continue for at least the next several hours. It is more
uncertain with regards to convective evolution overnight. Height
values will increase overnight as upper low slowly retreats,
but with deep southerly flow, high moisture values, and
instability, the potential for showers/thunderstorms will
continue overnight. Several models, including the HRRR actually
show convection increasing overnight, and thus will continue to
evaluate flood/flash flood risk overnight. Have extended flash
flood watch until 5 AM and will allow next shift to consider
flash flood watch for Monday.
Some patchy fog is also possible overnight. Lows will range from
the mid 60s to mid 70s.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY NIGHT/...
Plume of very high PW air >2.0 inches is expected to shift more
westward/inland as upper low drops into the Southeast and
heights rise along the coast Monday and Tuesday. Forecast wind
profiles indicate strong unidirectional flow very conducive to
training convection and model signal for heavy rain is stronger
with widespread convection. The flood threat will build with
each passing day as more areas get hit by rainfall. Locations
along and east of the Blue Ridge into north-central MD appear
at greatest risk of experiencing flash flooding, which could be
aided by southeast low level flow which could enhance
precipitation due to uplift along the terrain. Temperatures
will show a muted diurnal range due to the clouds and precip
with highs below normal and lows above normal.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
A trough of low pressure will remain stationary through Thursday,
thanks to a blocking 500mb ridge over the northern Atlantic. A
persistent train of moisture pushing up from the south will interact
with this trough to produce showers and thunderstorms on both
Wednesday and Thursday afternoon. Much of the shower and
thunderstorm activity should occur during the warmest time of the
day in the afternoon through the early evening hours each day.
Precipitable water values of 1.75 inches to 2.25 inches will aid in
heavy rainfall within the shower and thunderstorm activity. High
temperatures will be slightly below normal and low temperatures will
be slightly above normal due to cloud cover and showers and
thunderstorms.
The Upper level ridge over the northern Atlantic should begin to
break down and move east late Thursday into Friday, allowing for the
upper-level trough to finally move east. However, the trough looks
to again become stationary over the Delmarva Peninsula or VA
Tidewater region on Friday. The chance of showers and a few
thunderstorms will still linger Friday because of the added lift of
a weak front. This weak front could also bring some warmer
temperatures thanks to the southwest flow out ahead of it, with
highs closer to average.
Weak high pressure makes an attempt to dry us out Friday night into
Saturday, but could soon be followed up by an approaching upper
level disturbance from the west Saturday night and Sunday. This
upper level feature could bring a warm front northward and a couple
rounds of showers and thunderstorms along it or behind it.
Temperatures will be close to normal.
&&
.AVIATION /02Z MONDAY THROUGH FRIDAY/...
Largely VFR conditions exist this evening, aside from localized
reductions in scattered showers/thunderstorms. Conditions will
deteriorate overnight into MVFR with IFR conditions possible
towards dawn as ceilings lower. Conditions should improve
somewhat on Monday, but numerous showers/thunderstorms are
expected, so reductions likely to continue.
Occasional showers and storms will persist through Tuesday,
with rain possibly heavy at times. It`s tough to pinpoint any
period of worse conditions, although lower cigs will generally
be favored at night.
Showers and thunderstorms each day through Thursday. The warmest
time in the afternoon into the early evening hours would be the more
prominent time to encounter these showers and thunderstorms.
Occasionally MVFR or perhaps IFR could develop with the showers and
thunderstorms. Winds generally southeast to south at 5 to 10 knots
with higher gusts in thunderstorms through Wednesday night. Winds
could become southwesterly at 5 to 10 knots Thursday ahead of the
trough. Winds could shift to more westerly later Thursday night and
Friday with a trough moving across the region.
&&
.MARINE...
Scattered showers and thunderstorms with gusty winds which may
require Special Marine Warnings continue through this evening.
SCA conditions will continue to be possible through Tuesday
night, especially on the Bay and lower Potomac. Have maintained
the SCA through Monday night for these areas. Winds and waves
will also be locally higher in t-storms.
Small craft advisories possible Wednesday and Wednesday night for
the main stem Chesapeake Bay near and around the Tidal Potomac.
Winds southerly around 10 knots gusts to 15 to perhaps 20 knots
Wednesday and Wednesday evening. Winds becoming southwest to
westerly 5 to 10 knots gusts 15 knots Wednesday night and
Thursday.
&&
.HYDROLOGY...
Repeated rounds of showers and thunderstorms through the first
half of the week will lead to increasingly susceptible
conditions for not only flash flooding but eventually some river
flooding. Additional Flash Flood Watches and river related
products will likely be required, and those with sensitive
interests will want to start making plans.
&&
.TIDES/COASTAL FLOODING...
Gusty southerly flow will continue to lead to elevated water
levels for the next several days. Multiple Coastal Flood
Advisories are in effect through tonight. The overnight high
tides will be favored. Daily fluctuations are proving difficult
to pinpoint though, so adjustments to the forecast are likely.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...Flash Flood Watch until 5 AM EDT Monday for DCZ001.
Coastal Flood Advisory until 10 AM EDT Monday for DCZ001.
MD...Flash Flood Watch until 5 AM EDT Monday for MDZ004>006-011-013-
014-016>018-503>508.
Coastal Flood Advisory until 3 PM EDT Monday for MDZ017.
Coastal Flood Advisory until 9 AM EDT Monday for MDZ014.
Coastal Flood Advisory from 2 AM to 9 AM EDT Monday for MDZ011.
VA...Flash Flood Watch until 5 AM EDT Monday for VAZ052>057-506.
Coastal Flood Advisory from 3 AM to 8 AM EDT Monday for VAZ054.
WV...None.
MARINE...Small Craft Advisory until 6 AM EDT Tuesday for ANZ531>534-537-
539>543.
Small Craft Advisory from 11 AM to 8 PM EDT Monday for ANZ530-
535-536-538.
&&
$$
SYNOPSIS...ADS
NEAR TERM...ADS/MM
SHORT TERM...ADS
LONG TERM...CJL
AVIATION...ADS/MM/CJL
MARINE...ADS/MM/CJL
HYDROLOGY...MM/ADS
TIDES/COASTAL FLOODING...MM/ADS
Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
656 PM CDT Sun Jul 22 2018
.SHORT TERM...(This evening through Monday)
Issued at 250 PM CDT Sun Jul 22 2018
Another pleasant day today with early morning stratus burning off
into cumulus, dew points in the low 60s, light winds, and
temperatures in the mid 70s to lower 80s. Increasing moisture in
the central and northern Plains however is expected to result in
evening and overnight convection over the Dakotas. This will
weaken to perhaps just a few showers by the time it reaches west
central/central MN late tonight due to very limited instability.
Maintained chance PoPs, but reduced the thunder mention. CAMs are
not too optimistic for more than a few showers either.
The cold front will be pushing through in the morning. Some
instability will build near and ahead of it by early afternoon and
some thunderstorms could develop along and east of I-35.
Convergence will be very weak, and the lack of focus will be a
detriment to more widespread activity. Did increase PoPs 10 to 20
percent from the previous forecast, but they remain about 40
percent or less.
.LONG TERM...(Monday night through Sunday)
Issued at 250 PM CDT Sun Jul 22 2018
Past Monday night, the best chance of widespread rainfall will occur
Wednesday/Wednesday night as a stronger frontal boundary, and
associated short wave, moves across the Upper Midwest. Once this
front passes, the onset of much cooler temperatures develop with
readings averaging 5 to 10 degrees below normal for late July.
Models have been consistent with this stronger cold front on
Wednesday, but slight timing differences were noted with the EC
slower than the Operational GFS, or the parallel GFS. However, even
with timing differences, the stronger short wave will allow for
better upper level dynamics, and the potential of widespread one
quarter to one half inch of rainfall.
As the main storm system begins to sagged southward into the Great
Lakes region by late in the week, I wouldn`t be surprised to see a
few instability showers as the core of the cold air rotates
southward Thursday or Friday.
There will be a brief moderating in temperatures next weekend as the
core of the coldest air moves southward. However, the mean upper
pattern is conducive for another surge of abnormally cold air
arriving the last week of July, and into early August. Although it
doesn`t appear to be record cold, forecast dew points the week of
July 30th lowers into the 30s/40s in northern Minnesota, with
40s/50s in southern Minnesota.
Overall, there is a high probability of cooler than normal
temperatures after Wednesday, with lower chances of rainfall and
more comfortable humidity levels.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 654 PM CDT Sun Jul 22 2018
Thunderstorms forming along a cold front in the Dakotas are
expected to encounter a hostile environment over MN as we sit in
an area of subsidence to the west of the expansive upper low
across the lower Great Lakes and Ohio Valley. As a result, have
kept TAFs dry, save for a VCSH mention out at AXN. The HRRR and
HopWRF are not very promising for seeing much precip locally with
the fropa, so continue the theme of dry TAFs. Behind the front,
there could be a brief period of MVFR cigs across central MN, but
confidence in seeing cigs that low this far south is low enough
where VFR conditions were maintained at all terminals.
KMSP...Can`t completely rule out a stray shra/tsra between 16z and
20z, but chances for seeing anything are too low to include in the
TAF at this point.
/OUTLOOK FOR KMSP/
Tue...VFR. Wind NW 5-10 kts.
Wed...Chc MVFR/-SHRA/-TSRA. Wind W bcmg NW 10G20 kts.
Thu...Chc MVFR cigs. Wind NW 10G20 kts.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
&&
$$
SHORT TERM...BORGHOFF
LONG TERM...JLT
AVIATION...MPG
Area Forecast Discussion
National Weather Service Las Vegas NV
845 PM PDT Sun Jul 22 2018
.SYNOPSIS...Thunderstorm development will largely be inhibited
across much of the region except the southern Sierra this coming
week as a strong ridge builds over the southwest states. This will
lead to dangerously hot conditions across the Mojave Desert region
Tuesday through at least Thursday.
&&
.UPDATE...Thunderstorm activity today was mainly focused across our
northwest zones and near the Sierra, where a strong downpour near
Aspendell induced a series of significant mudslides. As of this
hour, most of the convection across Inyo county has died off, but
some weak showers linger across the Nevada Test site and parts of
Lincoln county. The current forecast is in good shape but I only
be making some minor adjustments for ongoing trends.
-Outler-
&&
.SHORT TERM...through Tuesday night.
Thunderstorms will persist over the southern Sierra and central
Nevada zones this afternoon and early evening. Several runs of the
HRRR have indicated central Nevada convection will propagate
southward late this afternoon and evening. This will need to watched
for the potential to move into Clark County this evening, but the
HRRR continues to indicate convection will dissipate before reaching
the northern border.
The high centered over New Mexico will slowly migrate west over the
next few days. The midlevel southwest flow over our region will
result in a gradual drying and stabilization in the 700-500 mb layer
and become less favorable for thunderstorm development. However, low
level moisture will only decrease slightly with dewpoints lowering
to around 50 degrees F...which will lead to elevated discomfort as
temperatures climb to within a couple degrees of record levels for
Mojave Desert sites from Tuesday onward.
.LONG TERM...Wednesday through Sunday.
There is little change in overall thinking with high confidence that
strong high pressure over the area will lead to excessive heat for
much of next week. Still looking for temperatures to run about 10
degrees above normal for most areas which will put places like Las
Vegas in the 111-115 degree range, the Colorado River Valley 116-
121, and Death Valley seeing highs 123-127. Extended numerical
guidance shows some slight cooling occuring by next Friday and
Saturday, but with the high not moving much not really sure how much
temperatures will actually cool. With the strong high over the area,
this will keep any significant moisture from working into the area.
It does look like there will be enough residual moisture around
leading to isolated higher terrain storms, but at this time nothing
widespread. However, this is monsoon season and thing can change
rather quickly.
&&
.AVIATION...For McCarran...Thunderstorm potential will be inhibited
around southern Nevada through Monday and much of the coming week.
Otherwise, winds will favor typical diurnal directions with speeds
generally less than 8 knots.
For the rest of southern Nevada, northwest Arizona and southeast
California...Isolated to scattered thunderstorms over the southern
Sierra and central Nevada will gradually dissipate this evening.
Storm coverage Monday will diminish and should mainly be confined to
the Sierra and high mountains of central Nevada. The rest of the
region should see generally tranquil weather with winds less than 15
knots and FEW-SCT clouds with bases above 12 kft tonight and Monday.
&&
.SPOTTER INFORMATION STATEMENT...Spotters are encouraged to report
any significant weather or impacts according to standard operating
procedures.
&&
$$
SHORT TERM/AVIATION...Adair
LONG TERM...Gorelow
For more forecast information...see us on our webpage:
http://weather.gov/lasvegas or follow us on Facebook and Twitter