Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 06/26/19
Area Forecast Discussion
National Weather Service Bismarck ND
822 PM CDT Tue Jun 25 2019
.UPDATE...
Issued at 822 PM CDT Tue Jun 25 2019
Latest Bowman radar shows increasing low level reflectivities
being drawn into an area of thunderstorms (inflow region)
advancing from southeast Montana. The 00z HRRR had the best
initialization on this area and thus have updated PoPs this
evening/overnight based on the recent trends and HRRR forecast.
Likely to categorical Pops scoot into southwest ND by 03z, then
become isolated to scattered overnight as they move into south
central ND. This follows right along the track of a subtle 500mb
shortwave as it traverses along the ND/SD border.
UPDATE Issued at 556 PM CDT Tue Jun 25 2019
Latest local radars are void of any reflectivities across western/central
ND, however, Bowman radar shows higher reflectivities just south
of the border. Another area of showers/thunderstorms near Billings,
Montana continues to propagate east and southeast with time. This
is associated with a mid/upper level shortwave that will shift east
along the ND/SD border overnight. Timing appears to reach far
southwestern ND between 03z-06z, with the precipitation scooting
east and possibly extending into south central ND after midnight
and just past sunrise Wednesday. Current forecast has PoPs/overall
forecast elements handled well. Will continue to monitor for any
earlier development with the forecast precipitation and/or areal coverage.
&&
.SHORT TERM...(This evening through Wednesday)
Issued at 342 PM CDT Tue Jun 25 2019
Evening and overnight showers and thunderstorms highlight the
short term forecast.
Aloft, a trough is stationed over the western US with a closed
low off the coast of British Columbia, with gradual height rises
are present over the Central Plains. Surface high pressure is
centered to the southeast of the forecast area, with plenty of
fair weather cumulus forming over the forecast area. Westerly
downsloping winds and sunny skies earlier in the day have helped
warm temperatures across western and central North Dakota into the
mid to upper 70s. Enough instability is present with mid-level
cooling and daytime heating that some isolated rain showers are
possible across the north, but forcing is limited so expecting
this to be pretty isolated. High-res models have convection
developing tonight across southeastern Montana and northeastern
Wyoming, eventually progressing into southwest North Dakota late
this evening and overnight. Soundings from this area show almost
60 knots of deep layer shear but less than 500 J/kg of CAPE,
similar to a situation last week where convection was limited, so
only anticipating showers and general thunderstorms moving east
across southern North Dakota overnight and early Wednesday
morning.
As the ridge remains in place over the Northern Plains, expecting
precipitation to move out during the day with mostly sunny skies
under high pressure aloft. High temperatures are forecast to be
generally in the low 80s across all of western and central North
Dakota.
.LONG TERM...(Wednesday night through Tuesday)
Issued at 342 PM CDT Tue Jun 25 2019
Warm and humid conditions along with multiple chances for showers
and thunderstorms highlight the extended forecast.
Model guidance shows an embedded closed low in southwest flow
aloft moving over the Dakotas late Wednesday night, with another
round of showers and thunderstorms forecast to develop in Montana
and Wyoming. Environmental conditions look better than overnight
tonight with 35-40 knots of deep layer shear paired with
1000-2000 J/kg MUCAPE and steep low level lapse rates, so
certainly a possibility for strong to severe storms, although
still uncertainty storm mode and how long it can be sustained
into North Dakota.
The severe threat looks to continue through the weekend, with
upper level flow becoming even more southwesterly as the ridge
begins to shift east. Model guidance has consistently shown dew
points in the upper 60s to low 70s, providing instability for
thunderstorms every day. Still plenty of details to work out in
terms of location and timing but confidence is slowly increasing
for severe potential somewhere in the area . In addition to the
threat of thunderstorms, high dew points coupled with surface
temperatures in the upper 80s to low 90s will boost the heat index
to at or near heat advisory criteria.
&&
.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 556 PM CDT Tue Jun 25 2019
Vfr cigs/vsbys this taf period. However, a vcts was added at
KDIK, from 03z-09z Wednesday, and from 08z-16z Wednesday at KBIS.
An area of showers/thunderstorms will propagate from southern
Montana and into southwest and south central ND tonight. As the
precipitation area emerges and gets closer to the terminals, then
an amendment will be utilized if needed. Elsewhere, it will remain
dry this taf period.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KS
SHORT TERM...MJ
LONG TERM...MJ
AVIATION...KS
Area Forecast Discussion
National Weather Service Birmingham AL
645 PM CDT Tue Jun 25 2019
.UPDATE...
For 00Z Aviation.
&&
.SHORT TERM...
Do not see any real changes that are necessary this afternoon. the
latest RUC analysis has drier air over Central Alabama and slow
moving convection in Louisiana. Some sea breeze feature is also
possible but how much of this activity makes it into Alabama is
not clear. Kept the highest pops south and southwest the remainder
of the afternoon into the evening. Thereafter, a broad ridge
generally dictates the weather of the southern Conus. There will
be a weakness in the ridge over Central Alabama through Friday and
then this feature retrogrades toward Texas. Rain chances should be
close to seasonal with scattered convection possible each day and
diminishing in the evenings. High temps stay at or just above
normals while lows are very close to normal.
75
Previous short-term discussion:
Monitoring convective trends early this afternoon over Louisiana
with a shield of associated cumulus beginning to overspread
southern Mississippi. Earlier expectations remain the same with
deep-layer westerlies keeping favorable moisture content along the
coast. Therefore, sea-breeze activity will increase along the
coastline in the following hours with additional outflow, from
thunderstorms over Louisiana, likely aiding in lift from
southeastern Mississippi into our far southwestern counties late
this afternoon. Added scattered rain chances in the far
southwestern corner this evening, but storms that are able to
maintain into the area will quickly lose intensity by 06Z as
daytime heating decreases after sunset.
86
.LONG TERM...
Wednesday through Monday.
Transitioning to a relatively benign flow pattern for the Southeast
by Wednesday will leave most rain chances (and any other problem
areas in the weather) to low-level and surface-based mesoscale
features into the long-term. Jet stream winds will generally reside
across the northern tier of the CONUS with a large scale trough &
upper-level low across the Pacific Northwest. From the Rockies and
eastward will lie a broad region of ridging, with the Gulf Coast
states humid/warm. Thus, most rain chances outside of Wednesday have
been left rather broad & diurnally driven as expected for this time
of year. There are some indications that some thunderstorm activity
will approach from the northwest on Wednesday, likely in response to
a subtle upper-level shortwave & potential remnant convective
systems moving southeastward from the mid-Mississippi River
Valley.
Temperatures across Central Alabama should range within a few
degrees of `normal` values for this time of year with upper 80s to
mid 90s for highs and upper 60s to mid 70s for lows, generally as
the surface layer cools to near dewpoint temperatures overnight. By
late week, the aforementioned shortwave and other mesoscale
mid/upper-level eddies (imagine a vorticity lava lamp) will
gradually rotate westward toward the Southern Plains with
amplification of the longwave ridge as it moves into the eastern
CONUS. It doesn`t appear to be until next week that any wholesale
synoptic pattern changes occur, though confidence on this is
still quite low. For now, daily chances for showers &
thunderstorms & a typical summer pattern will be the main theme
for the next several days. Though a strong storm can`t be ruled
out at some point this week, no severe weather is expected at this
time.
40/Sizemore
&&
.AVIATION...
00Z TAF Discussion.
Area of thunderstorms pushes eastward over the southern half of
Mississippi at this time with a shield of cirrus over Central
Alabama. The convection has decreased significantly over the past
hour. Current thinking is that chances are too low to include
mention in any terminals for the short term as it should continue
to deteriorate. Another wave of convection is expected from the
west in the morning. Have timed a mention for all except MGM/TOI
for during the daytime. MGM/TOI have lower chances as they will be
more removed from the best energy. Otherwise, VFR TAFs are
expected.
08
&&
.FIRE WEATHER...
Afternoon high temperatures will be at or slightly above normal
through the week. Minimum relative humidity values remain in the
50s through Wednesday and then drop slightly the remainder of the
week into the upper 30s. Rain chances appear on most days and in
most areas but should stay scattered or less.
75
&&
.PRELIMINARY POINT TEMPS/POPS...
Gadsden 67 90 66 91 66 / 10 30 10 20 10
Anniston 68 91 67 92 68 / 10 30 10 20 10
Birmingham 72 92 70 93 71 / 10 30 10 30 10
Tuscaloosa 72 92 71 93 71 / 20 40 20 30 10
Calera 70 90 68 92 69 / 20 30 10 30 10
Auburn 71 90 70 91 71 / 10 20 10 20 20
Montgomery 71 93 71 93 71 / 20 20 20 20 20
Troy 71 92 69 92 69 / 20 20 20 20 20
&&
.BMX WATCHES/WARNINGS/ADVISORIES/...
None.
&&
$$
75/86/40/08
Area Forecast Discussion
National Weather Service Jacksonville FL
908 PM EDT Tue Jun 25 2019
.UPDATE...Convection sparse this evening due to lack of any major
lifting mechanisms. There are a few showers moving offshore the
St Johns coast. High-res HRRR also indicating a few showers
possible across Marion county next few hours which should fade
after midnight.
&&
.AVIATION...A few showers will be moving offshore the St Johns
County coast next couple of hours and have VCSH at SGJ. Otherwise
prevailing VFR tonight. Brief period of low clouds possible early
Wed am but confidence not high enough to include in Tafs given
that the HRRR and SREF continue not supporting it.
&&
.MARINE...No headlines. South winds gradually veering to the
west and northwest tonight after seabreeze ends.
Rip Currents: Low risk expected Wednesday.
&&
.PRELIMINARY POINT TEMPS/POPS...
AMG 71 96 71 94 / 10 10 0 20
SSI 75 92 76 88 / 10 10 0 10
JAX 73 96 74 92 / 10 10 0 10
SGJ 75 92 74 88 / 20 10 10 10
GNV 73 96 72 93 / 20 10 10 20
OCF 73 96 71 93 / 20 20 10 20
&&
.JAX WATCHES/WARNINGS/ADVISORIES...
FL...None.
GA...None.
AM...None.
&&
$$
PP/AE/WC
Area Forecast Discussion
National Weather Service North Platte NE
637 PM CDT Tue Jun 25 2019
.SHORT TERM...(This evening through Wednesday night)
Issued at 344 PM CDT Tue Jun 25 2019
The primary forecast challenges through midweek revolve around
thunderstorm chances and increasing heat. A meandering surface
boundary will be the focus for convective development, while a
building upper ridge will allow highs to reach the 90s.
This evening and tonight... Monitoring convective initiation along
the Front Range and Laramie Mtns this afternoon and the environment
downstream. Several CAMS portray this activity to move into western
Nebraska after 00z, consistent with the H3-8 mean wind and steering
flow. RAP mesoanalysis indicates sufficient CAPE (around 2000 j/kg
MU) and deep layer shear (35-40 kts) across western Nebraska, which
would support continuation of any thunderstorms that make it here.
The limiting factor in widespread activity is moisture. Dew points
are steady in the mid 50s, and forecast soundings suggest a small
cap around H7. Despite the potential for something more, am thinking
any coverage will be isolated to scattered as the main wave
traverses western Nebraska. Generally capped PoP to around 30. That
being said, the storms that do affect the area will have the
capability of producing large hail and strong winds. Agree with the
blanket MRGL risk for the area as given by the SPC. Forecast
soundings suggest a fat elevated CAPE profile including the -10 to -
30C zone, as well as sufficient DCAPE and veering low/mid level
winds. For min temps, bumped up a degree or so using the warmer
guidance. Southerly H85 flow strengthens to 20+ kts as temps hold in
the lower 20s C and cloud cover increases (likely cirrus blowoff
with some lower ceilings around the storms). Forecast lows range
from mid 50s panhandle to lower 60s north central, which is right
around or just above normal values. The other forecast concern is
patchy fog toward dawn, primarily in the Platte River Valley.
Surface winds lighten and turn southeasterly overnight and into the
early morning hours. Confidence is low in development (cloud
cover/wind speeds), so have left out of forecast for now.
Wednesday and Wed. night... Stage is set for one of the warmest days
of the season so far. Southerly H85 flow continues while the sfc
front lifts north to along the SoDak border. Blended in warmer
guidance to give upper 80s north central and near to just above 90F
elsewhere. South/southeast sfc winds draw in extra moisture with dew
points reaching the mid 60s in central Neb. The combination of the
main front along the northern periphery of the CWA and a sfc trough
setting up in the panhandle/western CWA will be the foci for
additional thunderstorms, especially during the afternoon and
evening. An approaching H7 shortwave will provide forcing in the mid
levels. Severe indices (overall CAPE and shear) are favorable once
again. The NAMnest and SPC HREF suggest an MCS following the nose of
the LLJ in SoDak, rounding southeast and clipping Boyd/Holt Co after
09z. Included widespread chc PoP through the evening for at least
scattered convection and extended PoP far north central for possible
second round/MCS.
.LONG TERM...(Thursday through Tuesday)
Issued at 344 PM CDT Tue Jun 25 2019
The primary forecast concern through the weekend is the first true
heat wave of the season. The Central US upper ridge continues to
build with the 594dm isopleth centered over the Sandhills Fri-Sun.
H85 winds are consistently out of the south as a couple 28C+ thermal
ridges cross the High Plains. Guidance has trended warmer with
widespread mid 90s for highs Fri/Sat and lower 90s Sun. Moisture
advection over central Neb will lead to dangerous heat index
readings for part of northeastern CWA (Holt/Boyd). Will need to
monitor for potential headlines (criteria is 100F+). Precip chances
return late Saturday, albeit isolated, then increase Sunday and
beyond as a frontal boundary stalls near the Black Hills and the
upper ridge slowly moves east.
&&
.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 636 PM CDT Tue Jun 25 2019
VFR conditions are forecast at the KLBF and KVTN terminals the
next 24 hrs. There will be isolated to widely scattered showers
and thunderstorms tonight to move east across wwestern Nebraska.
Confident remains low to mention any prevailing conditions for
thunderstorms at the KLBF and KVTN terminals. Kept a mention of
VCSH from 05Z to 07Z with the passage of any activity. Will
monitor the progresion of showers and storms curretnly moving
throught the Nebraska panhandle.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SHORT TERM...Snively
LONG TERM...Snively
AVIATION...Roberg
Area Forecast Discussion
National Weather Service Lake Charles LA
801 PM CDT Tue Jun 25 2019
.AVIATION...
Storms have ended for the most part with moderate areas of rain
falling acrs se Texas and srn Louisiana this evening. Cloud
heights to vary but should remain abv MVFR/IFR flight conditions
thru sunrise. For for some additional storms a bit later.
&&
.PREV DISCUSSION... /issued 754 PM CDT Tue Jun 25 2019/
UPDATE...
Light rain still ongoing as the rain continues to
slowly dissipate. After midnight...will keep slight
pops for any further development. Best chance of rain
is in southeast Texas along the coast after midnight and even
then we are not expecting more than 30 percent. This forecast
is based on a worked over atmosphere and HRRR 1 hour forecasts
that look out through the night. HRRR is not showing much.
Have updated pops for ongoing light rain...and modify temps some
but kept overnight lows in place as we could see some slight
warming as southerly light winds return.
PREV DISCUSSION... /issued 349 PM CDT Tue Jun 25 2019/
SYNOPSIS...
Showers and thunderstorms will continue in the forecast through
Wednesday for southeast Texas and extreme western Louisiana as
abundant moisture and upper level disturbances will initiate
activity. Frequent lightning, brief heavy rainfall, and brief
gusty winds can be expected with the storms. A mid level ridge
will begin to work into Acadiana on Wednesday then through the
remainder of the forecast area on Thursday, briefly reducing rain
chances. A general weakness aloft and abundant Gulf moisture will
bring elevated rain chances over the weekend.
Rua
DISCUSSION...
Tail end of an upper level trough has left a general weakness over
western Louisiana and along the Texas coast while a mid level
ridge remains over the north central Gulf. Plenty of Gulf moisture
getting squeezed between these two features and over the forecast
area. Meanwhile, disturbances moving in the southwest flow out of
old Mexico and deep south Texas, helping to interact with the
moisture and produce areas of showers and storms. Some of the
storms especially moving into lower southeast Texas and lower
southwest Louisiana could be on the strong side, with frequent
cloud to ground lightning, brief heavy rainfall, and brief gusty
winds. This initial activity will decrease during the evening
hours.
On Wednesday, the mid level ridge will try to push eastward into
the forecast area. This will likely reduce rain chances for
Acadiana. However, looks like another disturbance moving up the
Texas coast will get another complex of storms going overnight
that will move into southeast Texas and southwest Louisiana on
Wednesday morning.
By Thursday, the mid level ridge should move into the forecast
area. Drier air, especially seen between the 85H-70H layer should
help put a lid on most convection from developing.
This ridge will move westward into Texas on Friday and begin to
lost its identity leaving a general weakness aloft.
Over the weekend into early next week could be on the general wet
side. Upper level weakness looks to deepen into a cut off upper
level low or trough. Meanwhile, a series of inverted troughs in
the low levels will allow plenty of Gulf moisture to surge into
the forecast area. Therefore, looks like elevated rain chances
from Saturday through the end of the forecast period. The best
chance and coverage of the shower activity will be in the
afternoon hours. However, with the very moist air mass in place,
convection could develop at any time. Also, some locally heavy
down pours could occur with any of the stronger convection that
develops.
Rua
MARINE...
An upper level disturbance working up the Texas coast will bring
showers and thunderstorms over the coastal waters of southeast
Texas and southwest Louisiana for the remainder of the afternoon.
This activity will diminish this evening, with another round
possible overnight into Wednesday morning. Locally higher winds
and seas, along with frequent cloud to water lightning can be
expected with the storms.
Otherwise, a low level high pressure system will move into the
northwest Gulf of Mexico for the remainder of the week. This will
bring about mainly light winds and decreasing seas, away from any
convection.
An upper level disturbance will combine with increasing moisture
to provide elevated chances for showers and thunderstorms over the
weekend.
Rua
&&
.PRELIMINARY POINT TEMPS/POPS...
AEX 71 91 70 92 / 20 30 10 20
LCH 74 89 74 93 / 40 30 10 10
LFT 73 92 73 94 / 20 20 10 20
BPT 75 88 75 92 / 40 30 10 10
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...None.
TX...None.
GM...None.
&&
$$
AVIATION...19