Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 05/15/20
Area Forecast Discussion
National Weather Service La Crosse WI
1045 PM CDT Thu May 14 2020
.SHORT TERM...(This evening through Friday)
Issued at 145 PM CDT Thu May 14 2020
Per GOES imagery at 18Z, a partial clearing trend continues as
cellular stratocumulus is widespread over the forecast area. The
surface wind pattern is quite muddled and thus have gone upstairs a
bit to resolve where convergence will be favored later today. In
the last 1-2 RAP/HRRR/HRRR Dev runs, there has been a slight step
southward with northern edge of storm development later this
afternoon. HRRR/HRRRdev reflectivity also confirms the southern
trend. Partial clearing in eastern IA and northern IL is allowing
some warming and dewpoints are now 60-63F near Hwy 20. Latest RAP
theta-e convergence in the 850-925 mb layer is on KDBQ, with a RAP
modified sounding for 68/62F yielding about 500 J/Kg. If temps
rise more, we may go to 750 J/KG. But alas, the bit further south
location has possibly begun a decreasing storm trend for Grant
and Clayton counties. Will continue to monitor this trend before
the forecast is updated. SBCAPE would have to overperform in the
next hours to get a severe storm threat as well, but supercell
shear is in place.
There will be a passing shower chance across northcentral WI from
the strong shortwave trough currently shifting east over ND. This
should pass a cold front through after midnight and usher in a good
cold advection surge overnight. Low-level convergence and lapse
rates are best over northern WI, with Taylor county on the
southern edge of the shower chances per CAMS.
Friday is a wonderful weather day.
.LONG TERM...(Friday night through Thursday)
Issued at 233 PM CDT Thu May 14 2020
Focus turns to Saturday afternoon into Sunday...the 14.12z
GFS/NAM/ECMWF are in decent agreement in building surface ridge
over the Eastern Great Lakes Region and southern Canada. Southerly
moisture return flow increases late Saturday afternoon and
evening mainly across the southern forecast area...in advance of
closed upper level low. With strong 500-300mb positive vorticity
advection/forcing in association with the closed upper level
low...showers/storms will be on the increase Saturday afternoon
into early Sunday. Shower/storm chances taper off during the day
Sunday...as the closed/surface low tracks into the Ohio River
Valley. At this time...thunderstorms should remain below severe
limits...with the 14.12z GFS/NAM show a few hundred 0-6km most
unstable CAPE and bufkit soundings limited elevated instability
across the southern parts of the forecast area.
Main forecast concerns Sunday night into Thursday are temperatures
through the period. The 14.12z GFS/ECMWF/GEM are in good
agreement cutting off closed low over the eastern United States
through the period and amplifying upper level ridge over the
central United States. The 14.12z NAEFS continue to show 850mb
temperatures standard anomalies in the 1 to 2 celsius degrees
above normal across much of the forecast area through the period.
High temperatures are expected to be in the 70s and lower 80s.
With the upper level ridge dominating the weather pattern for much
of next week and subsidence under the ridge...forecast area will
remain mainly dry through the period.
&&
.AVIATION...(For the 06Z TAFS through 06Z Friday night)
Issued at 1045 PM CDT Thu May 14 2020
Cirrus blown off from storms to our south will clear out of the
area later tonight. Meanwhile a weak boundary dropping through
the area will bring some passing VFR lower clouds. Expect mostly
SKC by daybreak followed by some afternoon cu and increasing
cirrus. Light winds will become northwesterly early this morning
and eventually northerly by late afternoon.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
IA...None.
&&
$$
SHORT TERM...Baumgardt
LONG TERM...DTJ
AVIATION...Kurz
Area Forecast Discussion
National Weather Service Austin/San Antonio TX
625 PM CDT Thu May 14 2020
.AVIATION...
No significant changes from the previous forecast. VFR conditions
will prevail through the evening at all terminals with breezy
southerly to southeasterly winds. MVFR ceilings will develop around
midnight. Ceilings will drop to IFR in the San Antonio area late in
the overnight period. There is chance for IFR in Austin, but we think
it`s unlikely. Ceilings will rebound to VFR around noon. Showers and
thunderstorms are likely starting Friday afternoon, but exact timing
is too hard to pin down at this time.
&&
.PREV DISCUSSION... /ISSUED 246 PM CDT Thu May 14 2020/
SHORT TERM (Tonight through Friday Night)...
For this afternoon and tonight a few isolated showers and
thunderstorms will continue through about sunset across areas east
of Interstate 35. With rich Gulf moisture in place and dew points in
the upper 60s to near 70 all it took was the sun coming out behind
this morning`s complex of storms to kick off the isolated activity.
Model soundings show convective temperatures in the mid to upper
80s, which we have already hit so the rising air created by the
heating of the earth`s surface was enough lift to initiate the
storms. The HRRR and other high resolution models show any activity
quickly dying out this evening.
Tonight and first half of Friday should be fairly quiet with low
clouds forming overnight across most of the area. The long
advertised trough will approach Texas tomorrow morning and begin to
slowly move across the state. By tomorrow afternoon the trough will
be located across the Trans-Pecos and Concho Valley. Here it will
act as an additional source of lift for the sharp West Texas dryline
and spark off initially isolated strong to severe storms west of our
area in a very moist and instability rich environment (CAPES of over
2500 j/kg). Shear will be limited so the initial threat with these
storms will be large hail as they approach the Rio Grande Plains and
Edwards Plateau between about 4pm and 9pm.
As the trough continues to move eastward it will begin to deepen and
develop into a cut off low almost right over top of South Central
Texas. The individual storms out west will form into a Mesoscale
Convective System (MCS) and march eastward. At the same time the
northern part of the trough will spark off another MCS across north
Texas, the Red River, and Oklahoma. While specifics of the solutions
differ most high resolution models (Texas Tech WRF, the SPC HREF
members, etc.) show these two complexes impacting our area either
nearly at the same time or a few hours apart between midnight and
some time early Saturday morning. With these both being lines of
storms the main severe weather threat will transition from a hail
threat to a damaging thunderstorm wind threat as the line(s)
approach the I-35 corridor.
In addition to the severe threat there is also the continued threat
for heavy rainfall which could lead to flash flooding. While the
more progressive and faster solutions put forth by the morning high
resolution models might suggest lesser rainfall amounts, the
tropical environment that we are in means that any of these storms
could produce significant rainfall amounts in a short period of
time. Tuesday`s event saw anywhere from 10-13 inches fall over
Central Comal County in a matter of hours, while this morning`s
system produced another quick 1-1.5 inches from Rocksprings to
Western Bexar County. The precipitation we have seen this week just
means that the drought stricken ground that we had seen up to this
week is now at least partially waterlogged leading into the next
major round of rain. This will increase runoff into the area creeks
and stream causing concerns for low water crossings and possibly the
main river systems as well.
While questions remain about the evolution of the cut off low going
into Saturday and Sunday which will ultimately help determine
overall rainfall totals (discussed below in the long term) the
threat for heavy rainfall and flooding means this event may be one
of our first big overnight rainfall events this year. In South
Central Texas it is ALWAYS important, especially at night, to Turn
Around, Don`t Drown. Use caution while driving at night in flood
prone areas, and frankly if you don`t have to travel during the
heaviest rainfall just stay home and enjoy the storms. You do not
know the condition of the roadway under the flowing water (it may be
washed out completely!) and it only takes a lit bit of swift moving
water to wash your car or truck downstream. There is always another
route you can find or another time for that errand or trip. Driving
into flooded lower water crossings puts you, your passengers, and
first responders at an unnecessary risk. Also, remember to have at
least three sources of receiving weather warnings Friday through
Sunday. This could include Wireless Emergency Alerts, Local Alerting
Systems like Warn Central Texas, Cell Phones, Social Media, TV,
Radio, the Internet and more.
LONG TERM (Saturday through Thursday)...
The complex of showers and thunderstorms producing locally heavy
rainfall will continue to move from west to east through about noon
Saturday. By early to mid Saturday afternoon it appears that the last
of the heavy rainfall should be east of the region, although some
isolated to scattered showers and thunderstorms may linger. The
majority of the guidance suggests that the heavy rainfall threat will
be over for good by this time, although the NAM does keep the cutoff
low over the region through Sunday night and produces another large
amount of rainfall across portions of Central Texas on Sunday.
However, most of the other models show just some isolated light
showers and thunderstorms for Saturday night and into Sunday, and
this NAM solution is being discounted by WPC as well. At this time we
continue to message total rainfall accumulations of 1 to 3 inches
with isolated pockets up to 5 inches for this weekend`s rainfall
event.
Ridging builds back in over the region by Sunday evening as the
trough moves east into the Southeastern US. A few showers may
continue to linger across the Coastal Plains on Monday, but otherwise
the region should remain dry through Thursday aside from maybe a
stray shower or storm on Wednesday and Thursday afternoon across the
Coastal Plains. High temperatures will gradually warm from Monday
through Thursday, with highs on Thursday ranging from the upper 80s
across the Hill Country and Central Texas to the mid 90s along the
Rio Grande.
&&
.PRELIMINARY POINT TEMPS/POPS...
Austin Camp Mabry 73 86 68 79 67 / - 30 80 80 30
Austin Bergstrom Intl Airport 72 86 68 79 66 / - 30 80 80 30
New Braunfels Muni Airport 72 87 68 80 67 / 10 30 80 80 20
Burnet Muni Airport 70 85 66 79 64 / - 30 80 70 20
Del Rio Intl Airport 75 90 68 92 69 / 10 40 80 20 -
Georgetown Muni Airport 72 86 67 79 65 / - 30 80 80 30
Hondo Muni Airport 72 91 67 86 67 / 10 30 80 60 10
San Marcos Muni Airport 72 86 67 79 66 / 10 30 80 80 30
La Grange - Fayette Regional 73 87 70 80 67 / 10 30 60 80 40
San Antonio Intl Airport 72 88 69 82 68 / 10 30 80 70 20
Stinson Muni Airport 74 88 70 82 69 / 10 30 80 70 20
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
Short-Term/Aviation...05
Long-Term...04
Area Forecast Discussion
National Weather Service Goodland KS
525 PM MDT Thu May 14 2020
.SHORT TERM...(This evening through Friday night)
Issued at 126 PM MDT Thu May 14 2020
Satellite and 500 mb RAP analysis showed southwest flow aloft across
the tri-state region today, with a closed low passing through the
northern Plains. Cloud cover dissipated and pushed southeast through
the morning, yielding sunny skies by the afternoon. At 1:30 PM MT,
northerly winds were observed at 10 to 20 mph, with temperatures
ranging in the 70s.
A disturbance is expected to push through the flow, bringing chances
for showers and thunderstorms to the region tonight. Storms will
develop along the Front Range this afternoon and push into the
region through the overnight hours. A couple of strong to severe
storms will be possible, with the best chance of severe weather
along and south of Interstate 70 in the late afternoon and early
evening. Marginally severe hail and winds will be the main threats.
Beyond this, am thinking weakened convection will traverse the area
tonight. Will need to monitor for redevelopment along a frontal
boundary extending across southern Kansas. Lows will be in the mid
40s to low 50s.
Southwesterly flow continues aloft on Friday, with high temperatures
in the 70s and southeast winds at 10 to 20 mph. A break from
precipitation is expected during the day before a shortwave helps
generate the next round of showers and storms. Convection is
expected to develop along a lee trough in the afternoon and spread
eastward into the region through the evening. Cannot rule out some
organized/supercellular storms initially; however, current thinking
is a line of storms/MCS will be the main mode with primary hazards
of strong winds, large hail, and heavy rainfall. The most likely
area for severe weather will be along and west of Highway 27 and
north of Interstate 70. If the MCS holds together, the threat could
extend as far east as a McCook to Leoti line. Temperatures fall into
the mid 40s to low 50s as storms pass through Friday night.
.LONG TERM...(Friday night through Thursday)
Issued at 244 PM MDT Thu May 14 2020
An upper level shortwave trough moves across the northern Plains
Saturday as high pressure builds over the western U.S. A ridge moves
into the central U.S. Saturday night traversing eastward across the
area through Tuesday night. A trough begins to move over the
Intermountain West Tuesday. It lifts as it moves eastward with the
associated closed low over Montana and Wyoming by Wednesday night.
Troughing remains over the western U.S. as the closed low moves
north northeast into south-central Canada Thursday. Southwest flow
aloft sits over the Tri-State region Monday night through Thursday.
High pressure sits over the Tri-State area Saturday through Tuesday
night. Leeside troughing develops along the Front Range of the
Rockies extending southward into eastern Colorado by Wednesday. As
the surface trough shifts eastward with the axis along the CO/KS
border by Thursday, a cold front begins to move into the CWA from
the west northwest.
High temperatures will range from the upper 60s to lower 90s with
lows in the lower 40s to lower 60s. Saturday and Saturday night will
be the coolest time periods in the extended forecast period. There
is a chance for some rain and thunderstorms Saturday into Saturday
night before the forecast dries out through mid-week next week.
Chances for thunderstorms return Wednesday evening.
During the dry periods, there are a couple of elevated fire weather
condition days expected. During the afternoon hours next Tuesday
through Thursday, areas of low relative humidity values are expected
mainly west of the Colorado border. Thursday has the largest area of
low RH values across the CWA extending all the way eastward to
Highway 83. Wind gusts of up to or exceeding 25 mph are expected
Tuesday and Wednesday. Much of the CWA has `greened up` but the fire
weather threat still exists.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 521 PM MDT Thu May 14 2020
Cluster of high-based showers/isolated thunderstorms will move out
of northeast Colorado early this evening, potentially impacting
KGLD. Storms will continue to weaken, but may be accompanied by
brief gusty winds in the 20-30 kt range. Overnight, patchy fog may
develop with light easterly upslope flow in place. Confidence
rather low at this time. After about 14z, any fog/low clouds will
dissipate with VFR conditions expected through Friday afternoon.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...JBH
LONG TERM...NEWMAN
AVIATION...024
Area Forecast Discussion
National Weather Service Wichita KS
643 PM CDT Thu May 14 2020
.MESOSCALE DISCUSSION...
Issued at 636 PM CDT Thu May 14 2020
Continue to watch storms develop across Chase county which is
indicative of edge of the cap. Visibility satellite loop shows low
southeast of KGBD, near Hudson. Thinking main chances for storms will
be across Flint Hills and then into southeast KS during the
night. There is also a small chance for remnants of northeast CO
storms moving into central KS late tonight, but timing is a
suspect suspect. Considerable uncertainty with expected elevated
storms that several models develop in the 0600-0900 UTC time
frame as low level jet increases convergence over boundary.
Uncertainty stems from the variability in jet/boundary
intersection, which has been considerable over the past couple of
days. -Howerton
&&
.SYNOPSIS...
Issued at 330 PM CDT Thu May 14 2020
A trough is set up in the Plains with a secondary one off of the
West Coast. The front associated with this system straddles from
southern Iowa to central Kansas into southwest Kansas. After a
cloudy day yesterday, the sun came out today. Temperatures rose to
the 70s for most of the eastern half of the state with even the
lower 80s along the Kansas and Oklahoma border. Attention turns to
thunderstorm potential along the front this afternoon through
tonight.
&&
.SHORT TERM...(This evening through Sunday night)
Issued at 330 PM CDT Thu May 14 2020
Highlights:
1) Strong and severe thunderstorms southeast of KS Turnpike this
evening and tonight
2) Strong to severe thunderstorms late tonight into early Friday in
portions of south central Kansas
3) Flooding including flash flooding
4) Thunderstorm potential Friday and Saturday
Challenges:
1) Precipitation chances/coverage Friday
2) Rainfall amounts and respective flooding issues
3) Strength of convection on Friday and Saturday
Changes:
1) Precipitation chances and respective timing
2) Slight increase in temps in central Kansas on Friday
Headline: Flash Flood Watch this evening thru Saturday afternoon in
portions of south central and southeast Kansas
An active period will occur the next couple days with thunderstorms
anticipated this evening thru Saturday. There is concern for severe
storms especially this evening thru tonight with the possibility of
hail up to golf ball size and 60 mph winds which maintains the same
message as the last few forecasts. The movement of the front
mentioned in the Synopsis section is expected to be the driving
force for convective development as the instability rises especially
east of the Kansas Turnpike this afternoon and evening with 0-3km MUCAPE
of 3-4.5k J/kg and modest shear of 30-40kts at 0-6km. It is
questionable if the storms could develop well out ahead of the
front; CAMs are suggesting this may be a possibility, but the
better chances definitely appear closer to the front. As mentioned
in the previous discussion, it appears the convective mode would
be multicell with potential supercells more likely in northeast
Kansas and Missouri. There does appear to be somewhat of a linear
component later on. Initial development may be close to 4PM in
northeast Kansas with increasing coverage closer to the Flint
Hills around 7PM.
Thunderstorms are expected to back build further west into
central and south central portions of the state tonight into early
Friday as the front continues to track southeast. This front is
moving slow which would enhance the flooding threat with storms
staying closer to that boundary. There could be strong to severe
storms mainly southeast of Kansas Highway 61 or southeast of a
line from McPherson to Hutchinson to Pratt. Similar hazards are
anticipated with hail up to golf ball size and 60 mph winds.
The concern for flash flooding is on the uptick this evening as
moisture continues to surge northeast with a focus in eastern
Kansas. Rainfall totals the past seven days have ranged from 3 to
above 5 inches in the Flint Hills. Additional convection could
produce another 1 to 3 inches in well saturated areas with locally
higher amounts possible the next couple of days. The Flash Flood
Watch appears to be in line with the highest area of expected
rainfall. Please see the hydrology section for more information.
Friday afternoon - The better instability again looks like it will
stay further to the south which would reduce the severe thunderstorm
threat, but this is dependent on which model you decide is the most
representative. There are suggestions by the RAP and GFS that CAPE
will climb near 3k J/kg with 20-30kts of 0-6km bulk shear in the
afternoon and evening hours along the Kansas/Oklahoma border.
However, longevity of the morning activity could compromise the
environment as well. At this point, the lean is possible strong
thunderstorms with maybe some that approach severe criteria.
Confidence is not high for this time period in regards to the
strength of the storms.
Saturday - The last day of this active period will be Saturday; the
secondary wave which is just off the West Coast is expected to set
up along the Front Range late Friday then move through the Plains on
Saturday. This will bring another round of showers and thunderstorms
across the area. Some of the thunderstorms could be strong to severe
potentially in south central and southeast Kansas. Stay tuned for
updates on Friday and Saturday.
.LONG TERM...(Monday through Thursday)
Issued at 330 PM CDT Thu May 14 2020
Highlights: Quieter and warmer
An active week will be followed by a much quieter one as a ridge
moves in Sunday through the middle of next week. The mid and upper
levels form an Omega block pattern for the first part of the week
across the CONUS. After the wet week, it will be nice to have a
period to dry out. High temperatures are forecast to be in the 70s
for Sunday and Monday then to the low to mid 80s by Wednesday.
Seasonal normals are in the mid 70s. Low temperatures should stay in
the 50s. Take advantage of those outdoor activities if you are able
during this window.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 636 PM CDT Thu May 14 2020
Main concern is the timing and location of storms throughout most
of the forecast. While chances are possible for most of the
period, will limit thunderstorm to the high probability
sites/time. The chance highest after midnight in KCNU and very
late tonight at KICT and KHUT. Amount of lingering precipitation
will be highly dependent on orientation of boundary and low level
jet, items which models have not handled well of late. Expect
ceilings to become MVFR where there is persistent rain/upslope
flow towards daybreak and briefly in thunderstorms. -Howerton
&&
.HYDROLOGY...
Issued at 330 PM CDT Thu May 14 2020
Flash Flood Watch from 6PM tonight thru 7PM Saturday
Multiple rounds of showers and thunderstorms through this week which
are expected to continue into Saturday only amplify the flooding
threat. The highest rainfall totals in the last seven days have been
across southern Kansas with 3-5 inches with locally higher amounts
especially in the Flint Hills. As moisture transport increases
tonight along with the precipitable water values of 1.25-1.75
inches, flooding is going to become a greater concern especially in
the Flint Hills and areas to the east. The slow moving front will
not help. Flooding and flash flooding very well may occur tonight
and possibly the next couple of days in the low lying areas and in
towns. While only a few river points are forecast to rise into
action or flood stage at this time, there very well could be more
depending on how much rain falls within the respective basins.
Please stay weather aware and heed any road closures.
&&
.PRELIMINARY POINT TEMPS/POPS...
Wichita-KICT 65 76 63 78 / 80 70 60 70
Hutchinson 62 73 61 76 / 80 50 60 50
Newton 63 73 62 75 / 80 60 70 70
ElDorado 64 75 62 77 / 80 70 70 80
Winfield-KWLD 66 78 64 79 / 80 70 60 70
Russell 57 74 57 75 / 60 40 70 40
Great Bend 59 71 59 76 / 80 40 60 40
Salina 60 75 61 75 / 30 50 70 60
McPherson 61 73 61 75 / 80 50 70 60
Coffeyville 66 75 65 79 / 90 90 70 90
Chanute 64 76 64 77 / 80 80 70 90
Iola 64 76 64 77 / 80 70 70 90
Parsons-KPPF 66 76 64 78 / 80 80 70 90
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
Flash Flood Watch through Saturday evening for KSZ069>072-083-
092>096-098>100.
&&
$$
MESOSCALE...PJH
SYNOPSIS...VJP
SHORT TERM...VJP
LONG TERM...VJP
AVIATION...PJH
HYDROLOGY...VJP
Area Forecast Discussion
National Weather Service Northern Indiana
748 PM EDT Thu May 14 2020
.SYNOPSIS...
Issued at 316 PM EDT Thu May 14 2020
Showers and thunderstorms will continue this afternoon with
moderate to heavy rain. The severe threat has diminished. Wet
weather will continue into Friday. Saturday should be mostly dry,
but more rain will move in Saturday night and Sunday.
&&
.UPDATE...
Issued at 707 PM EDT Thu May 14 2020
Have made slight adjustments on POPs for the evening and overnight
hours. Convection over the next few hours should be contained
south of HWY 30 along the leading edge of an EML. Overall logic to
the forecast hasn`t changed, another round of convection is
expected as a shortwave moves across the mid-MS valley sending
the ongoing convection over IA into the forecast area much later
tonight. Deep layer shear continues to look on the lower side
(20-25kt 0-6km) overnight while instability of 1000-2000 J/kg
continues to migrate northwards accompanied by dewpoints in the
mid to upper 60s.
One feature which could help in the shear department is the MCV
steadily moving northeast from southern MO. Given it`s current
track, the center will likely slide across far NE IN/NW OH. This
wouldn`t be a great trajectory for storm organization for most of
the area, but if a storm can initiate on the east side of the
center then it would be in a better environment. The HRRR has
picked up on this feature which shows most of the additional
storms developing on the N to NE side of the MCV north of Hwy 30.
Should this prove true, then the MCV wouldn`t provide much aid to
storm intensity.
Continue to think the greatest severe hazards tonight remain
strong to damaging wind gusts and heavy rain leading to flooding.
Will likely add our remaining MI counties into the watch given the
influences of the MCV allowing for a greater eastward expansion
of storms as it moves north around midnight.
&&
.SHORT TERM...(This Evening through Friday)
Issued at 316 PM EDT Thu May 14 2020
A shortwave currently over central Illinois is pushing an MCS
across northern Indiana this afternoon, and will eventually move
into northern Ohio. Showers and thunderstorms with moderate to
heavy rain can therefore be expected through early evening. The
forecast area remains in the warm sector with the warm front over
southern Michigan and the cold front extending from Wisconsin back
across the plains. It has become quite warm and humid with highs
in the 60s north to mid 70s southeast, and dewpoints in the 60s.
This has allowed the area to become fairly unstable with MUCAPE
500-1000 J/kg. However, shear is marginal at around 30 kts and
forecast to decrease this evening. With ongoing rain and
associated cooling, expect instability to decrease as well, and a
limited severe weather threat. Yet there could still be some
gusty winds up to 45 mph.
The current round of storms is expected to move out of the area by
late evening. There may be a break in activity, and then another
shortwave will move in from west around midnight with more showers
and thunderstorms. The biggest threat with this complex will be
heavy rain, especially across northwest Indiana and southwest
Michigan. An additional 1 to 2 inches will be possible during this
period, and some localized flooding or ponding of water could
occur. A Flood Watch has been issued.
The cold front will move through the area around mid-day Friday,
pushing moisture eastward. By evening, most of the area will start
to dry out and clouds will scatter. However, the front will stall
over the Ohio Valley, and light rain could persist over the
southeast counties. Despite the cold front, it will be mild on
Friday with highs in the 70s except 60s near Lake Michigan. Highs
are likely to occur early though, with cooler air moving in late
afternoon with the front.
&&
.LONG TERM...(Friday Night through Thursday)
Issued at 316 PM EDT Thu May 14 2020
A transitory ridge of high pressure will build in on Friday night
into Saturday morning. Dry weather may not last long though, with
another low pressure system poised to bring more rain and
thunderstorms on Saturday night into Sunday as a deep closed low
swings through the Great Lakes. Lingering showers due to wrap-
around moisture are now also forecast to persist on Monday and
possibly Tuesday as the low stalls over the SE US. Dry conditions
should return for Wednesday and Thursday, but confidence is low
since latest model runs hold onto the low through the end of the
week.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday Evening)
Issued at 707 PM EDT Thu May 14 2020
Chances for convection will keep confidence low for the 00z TAf
cycle. Initial round of convection has already gone through the
terminals and we should see a lull of activity over the first
couple of hours. Models show an additional round of convection
possible for KFWA as a MCV over southern MO continues to move
northeast with time. KSBN could miss out on convection from this
feature and have it`s chances associated more with the eastward
progression of the complex of storms over IA. Have made
adjustments at both terminals to try to capture this brief lull
and renewal of convection at the terminals.
Given the slow progression of the convection and associated cold
front, KSBN will likely see the greatest impacts overnight. A
Prolonged period of degraded ceilings and visby is expected when
convection moves over the terminals. Outside of the initial
convection may have to wait until closer to 12z for the front to
bring convection to the terminals. Have also maintained LLWS
mention overnight as a strong LLJ moves over the terminals and
surface winds drop below 10kt.
An return to VFR is possible at the very end of this TAF cycle as
the cold front moves southeast of the terminals. Have introduced
this improvement with this issuance.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...Flood Watch through Friday morning for INZ003>005-012-014.
MI...Flood Watch through Friday morning for MIZ077>079.
OH...NONE.
LM...NONE.
&&
$$
UPDATE...CM
SYNOPSIS...Cobb
SHORT TERM...Cobb
LONG TERM...Cobb
AVIATION...CM
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Area Forecast Discussion
National Weather Service North Platte NE
659 PM CDT Thu May 14 2020
.SHORT TERM...(This evening through Friday night)
Issued at 201 PM CDT Thu May 14 2020
The NAM, HRRR and HREF suggest the potential for isolated strong
storms firing off the Black Hills or Pine Ridge this afternoon and
this evening. The focus across the Black Hills is diurnal
destabilization and across the Pine Ridge, it`s convergence around
the Black Hills in conjunction with a weak frontal boundary.
Given winds aloft are strong, near 45kts at h500mb, and
instability limited, storm coverage should be isolated and
accompanied by a southeast motion. Strong winds are the primary
hazard as the sustainability of updrafts is uncertain.
Other rain chances tonight hinge on an upper level disturbance
moving through srn WY and nrn Colo this afternoon. This disturbance
should affect wrn Nebraska overnight and slowly dissipate across
ncntl Nebraska Friday afternoon. Showers and isolated thunderstorms
are in place during this time.
The GFS, NAM and GEM regional models have perked up on a potential
heavy rain event Friday night. This is the first model run to show
heavy rain extending through swrn Nebraska. Previous model runs were
focusing the best rainfall across wrn Nebraska with a diurnal
enhancement. Now, the models are closing off a h700mb low Friday
night which moves slowly across swrn Nebraska to scntl Nebraska by
Saturday morning. 1 to 2 inches of rain could fall if the moisture
advection shown by the models materializes.
Any storm activity across cntl KS will disrupt the moisture
advection into Nebraska resulting in less rainfall. The NAM12 model
shows storms across KS while the NAMdng, the downscaled NAM, does
not show any storms across KS. The rain forecast Friday night uses
the short term model blend for likely to definite rain chances but
less than half of the QPF these models show.
Conditions Friday afternoon and early evening could support a few
strong or severe storms across swrn Nebraska and the eastern
Panhandle. Winds aloft at h500mb are modest at 25-35kts and the NAM
shows instability moving north through the Colo Plains. Any storm
activity which develops will move east into a more stable
environment across cntl Nebraska. SPC is now suggesting a slight
risk for severe storms across swrn Nebraska and the Panhandle late
Friday.
.LONG TERM...(Saturday through Thursday)
Issued at 201 PM CDT Thu May 14 2020
The h700mb low across Nebraska, if it forms Saturday as indicated
by the models, will move slowly through ern Nebraska and be located
across Iowa Saturday evening. The system will merge with another
upper low moving through the Dakotas to form a large closed h500mb
low across WI Sunday morning. This should pull a fresh batch of
Canadian air into Nebraska. The models have been very consistent
showing this and the morning model runs are building this high
pressure farther west.
The resulting model blended temperature forecast Sunday is cooler
with highs in the 60s to lower 70s. 70s to near 80 are in place
for Monday as the cool air is recycled north through KS and into
Nebraska.
Rain chances vanish Sunday through Tuesday. A very strong upper
level ridge of high pressure will from across Nebraska capping any
convection despite increasing heat and instability. Highs in the 80s
are in place Tuesday with dew points in the 50s. The 14C
temperatures at h700mb should cap storm development Tuesday. A
strong Pacific front accompanied by falling 500mb heights late
Wednesday is expected to set off what could be a fairly vigorous
round of thunderstorms affecting wrn and ncntl Nebraska. The front
is expected to stall across ncntl Nebraska Thursday presenting
cooler temperatures across the west but warm conditions across ncntl
Nebraska.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 659 PM CDT Thu May 14 2020
VFR conditions are forecast at the KLBF and KVTN terminals the
next 24 hours. At KLBF, VFR conditions tonight, with VCSH 09Z-12Z,
then -SHRA expected 12Z-18Z. An area of MVFR ceilings are expected
to develop and persist in southwest Nebraska, but should remain west
of the KLBF terminal. AT KVTN, -SHRA were ongoing at TAF issuance
wnd should continue until 02Z. After 12Z -SHRA are expected to
return and remain prevailing through the end of the TAF period.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SHORT TERM...CDC
LONG TERM...CDC
AVIATION...Roberg
AREA FORECAST DISCUSSION
National Weather Service New Orleans LA
1244 PM CDT Thu May 14 2020
.AVIATION...
Scattered to numerous showers and thunderstorms have developed
around all terminals and should continue to impact them from time
to time through this afternoon. Expect brief windows of reduced
visibilities from heavy rainfall and possibly gusty winds.
Convection should dissipate with time from west to east beginning
around 00Z with VFR returning through the overnight hours. A
repeat is expected tomorrow, so have added VCTS beginning around
15Z at TAF sites.
MEFFER
&&
.PREV DISCUSSION... /issued 616 AM CDT Thu May 14 2020/
..UPDATED AVIATION DISCUSSION...
SHORT TERM (Today through Friday Night)...
Starting out early this morning, short-range model soundings
continue to support a very moist surface to 850mb layer across the
area. This will keep low clouds and some patchy fog in generally
the same areas that experienced them yesterday (Pearl river
valley, southern MS and parts of coastal MS) - and have reflected
this in the gridded forecast package for today. Otherwise, any
lingering fog will quickly dissipate shortly after sunrise, but
mostly cloudy skies and low clouds will prevail through the day
today.
Quick overview of the weather maps this morning shows the same
surface high once anchored across the Great lakes to the Mid-
Atlantic states has pressed east out into the Atlantic, which
continues to promote strong southeasterly Gulf return flow of
moisture across the area. The closer proximity to the high
yesterday helped keep a lid on area convection generally east of
I-55, but that will change for today as much deeper moisture has
pulled into the area, with generally no lid/subsidence inversion
aloft. HRRR/NAM3KM guidance is in good agreement over the idea of
widespread scattered showers and thunderstorms over just about the
entire CWA, less for far coastal SE LA. A closer detailed
analysis with forecast model soundings illustrates a few
interesting tidbits to keep an eye out for. Noticing Tc`s today
will be very low, in the mid to upper 70`s along with CINH
dissipating around 13 to 16Z areawide. This may be a trigger that
the CAM`s are hinting at how convection will spark much earlier
today, possibly as early as mid to late morning and continuing
through the afternoon. Hodographs and the vertical wind profile
does not show much that stands out, other than impressive low-
level curvature (but with low wind magnitude) indicative of
support in the way of low-level warm air advection. The profile
aloft does however show a few interesting features, including the
well-advertised cooler mid-level layer with H5 temps around -12C,
in conjunction with an eventual well-mixed PBL as soon as the
clouds attempt to break up later today (DCAPE reaching around
1000J/kg). A few storms today may be on the strong side, and will
be watched closely. Storm motions today will be generally from
185-190 degrees, but look for many boundary interactions today due
to weak tropospheric wind flow. As a side note, some runs of the
HRRR develop convection early out west across Lake Charles, which
could send a eastward surging outflow boundary swinging across our
area, which would only add to the rain chances through the
afternoon and evening. PW`s in the 1.6 to 1.7 inch range along
with these boundary interactions/training potential does raise a
flag with isolated flash flooding concerns, and the WPC has placed
most of SE LA and S MS under a Marginal Risk of excessive
rainfall. Good news is this will be a much needed soaker today for
many, with all convection likely coming to an end before 8 to
9PM, with dry and humid conditions overnight.
Not much changing by Friday, with another round of showers/storms
in the late AM through afternoon and evening. Coverage should be
similar, if not slightly less but the overall strong storm risk
will be lower, has the mid-levels slightly warm to around -10C
with limited DCAPE. Few heavy downpours leading to localized
flooding possible, but the overall risk for widespread flooding
will be low.
LONG TERM (Saturday through Tuesday)...
By early Saturday, focus begins to shift out west as we see the
signs of a developing upper-level low progressing eastward across
Texas. Late hour recent runs of the CAM`s pick up on a very large
MCS/squall line racing just east of the downstream portion of the
upper-low early on Saturday, before running out of steam once
reaching the NW GOMEX late in the day. Here locally, we see a
slight surge of drier air in the troposphere within downstream
subtle ridging ahead of the trough out west, which lowers our
overall PW`s to around 1.0 to 1.1 inches, increasing Tc back to
90+F and limits overall convection, more confined to far western
areas.
Few things need to be watched here as we go into Saturday night
and into Sunday with long-range guidance suggestions: ECMWF/GFS
solutions are now picking up on this upper low being kicked east by
a SE diving shortwave across the Ohio Valley, which spreads this
upper-level energy east across our area early Sunday. What needs
to be watched are two things:
1) The early Saturday squall line/MCS racing across Texas,
eventually reaching the NWGOMEX in the afternoon evening. Will
there be enough outward projection/support in upper-level winds
along with mesoscale cold pooling to push this MCS farther east
than what guidance suggests? Increasing rain/storm risks for us
later on Saturday.
2) GFS runs have been indicating the potential for a large MCS to
race across the entire area - during peak heating on Sunday with
widespread 3,000+J/KG SBCAPE building out ahead in the pre-storm
environment. ECMWF also hints at a bit of a more messy solution,
but tries to still keep some enhancement of shower/storm coverage
across the area on Sunday.
Either way in this type of set up, you can confidently bet more
on the idea of a MCS racing somewhere across the area at some
point late Saturday or Sunday. Overall timing will set the degree
of severity in regards to severe weather risk, but this may need
to be closely watched, especially as CAM`s continue to attempt
and resolve these mesoscale features.
Beyond Sunday, there is now a good chance that we dry out thanks
to the same aforementioned shortwave across the Great Lakes
eventually closing off across the Ohio/Tennessee Valley region,
supporting upstream convergence/strong high pressure across our
area with drier conditions to follow into the middle of next week.
KLG
MARINE...
High pressure anchored just offshore the Mid-Atlantic coastline
will continue to promote southeasterly winds through the rest of
the weekend and weekend. Winds will be gusty at times, reaching 15
to 25 knots sustained for outer Gulf marine zones, lower for
tidal lakes and sounds. Persistent southwesterly winds though
however will keep a long period swell train in place with wave
heights reaching 3 to 7 feet for outer Gulf zones, with Small
Craft Advisory highlights in place for these areas - mentioning
higher waves as the main risk aside from near-criteria winds.
Winds/waves will steadily diminish into the weekend. KLG
DECISION SUPPORT...
DSS code: Blue.
Deployed: None.
Activation: None.
Activities: Marginal Risk for Excessive Rainfall Today and Tonight
Forecast support for critical IDSS sites.
River Flood Warnings along Mississippi River.
&&
.PRELIMINARY POINT TEMPS/POPS...
MCB 67 81 66 84 / 40 80 60 20
BTR 69 83 68 85 / 40 90 60 30
ASD 67 83 66 85 / 30 80 30 10
MSY 70 83 70 84 / 40 90 40 10
GPT 69 80 68 81 / 10 60 20 10
PQL 65 82 63 85 / 10 30 20 10
&&
.LIX WATCHES/WARNINGS/ADVISORIES...
LA...None.
GM...Small Craft Advisory until 1 AM CDT Friday for GMZ552-555-557-
570-572-575-577.
MS...None.
GM...Small Craft Advisory until 1 AM CDT Friday for GMZ555-557-570-
572-575-577.
&&
$$
Area Forecast Discussion...Updated
National Weather Service Saint Louis MO
1026 PM CDT Thu May 14 2020
.UPDATE...
Issued at 1026 PM CDT Thu May 14 2020
Cluster of showers and thunderstorms associated with a mid level
vort max continues to move slowly east across southeast Missouri.
Expect these showers and storms to persist late this evening as
they move slowly east across southeast Missouri.
Main concern continues to be with line of thunderstorm over
northern Missouri into northwest Illinois. Latest surface analysis
indicates that the stationary front extends from northeastern
Kansas across northern Missouri into northern Illinois. Showers
and thunderstorms continue along this front in an area of strong
low level moisture convergence underneath increasing mid level
ascent ahead of a shortwave trough moving across the Upper
Midwest. This trough in addition to the cold pool developing over
Iowa will act push the front south overnight. This will cause
showers and thunderstorms to move southeast across the area
overnight. There will remain the threat for heavy rainfall in the
flash flood watch as thunderstorms will be training into the
overnight hours with PWATS around 1.75 and deep warm cloud layers.
Still expect the line of storms to move south of the area after
12Z.
Britt
&&
.SHORT TERM... (Through Late Friday Night)
Issued at 350 PM CDT Thu May 14 2020
Remnant MCV is making it`s way into southwestern MO as of 20z with
scattered storms developing over WFO SGF`s forecast area. In the
meantime, isolated activity continues to fire up mainly along and
south of I-70 due to old outflow boundaries from the morning
activity.
Latest RAP indicating surface based CAPES between 2000 and 3000
J/kg, 0 to 6km bulk shear between 25 and 30 kts, as well as, little
to no CIN. So as MCV approaches region, will see scattered storms
develop along and south of I-70 corridor between now and 03z Friday.
Still expect isolated/scattered strong to severe storms during this
period with the main threats being large hail and damaging winds.
Once the sun sets and we lose daytime heating, activity will
diminish rather quickly.
Then the focus shifts back to the north with the main cold front
that will begin to slide through region late tonight. Latest CAMs
are indicating that storms will quickly congeal into a line and
slide southward through forecast area tonight through early Friday
morning. Model guidance as well as WPC guidance indicating that with
faster movement of this complex, rainfall amounts will be between a
half an inch and an inch in the Flash Flood watch area over portions
of central/northeast MO and west central IL. Even with lower qpf
amounts, will keep FFA and allow it to expire at 10z Friday after
coordinating with our neighbors to the west and southwest.
As for the severe threat with the cold front, strong 40 to 50 kt
low level jet will maintain an influx of richer moisture from the
southern Plains. So could see a few strong to severe storms with
large hail and damaging winds the main threats tonight.
Even though front will stall out over region, should see a bit of a
break in activity with just chance pops most locations during the
day on Friday.
By Friday night, another shortwave will slide along the boundary
triggering another round of showers and storms, mainly after 06z
Saturday.
Temperatures through the short term will remain a bit above normal
for this time of year.
Byrd
.LONG TERM... (Saturday through Next Thursday)
Issued at 350 PM CDT Thu May 14 2020
With the front stalled out over region, will see several more rounds
of showers and storms Saturday through Sunday, before boundary is
finally pushed south of region and surface ridge builds in. Dry
weather expected for the remainder of the forecast period. As for
temperatures, the synoptic set up remains favorable for an omega
block pattern that will keep the region in the northwest flow aloft,
so temperatures will be near or slightly below normal through the
work week.
Byrd
&&
.AVIATION... (For the 00z TAFs through 00z Friday Evening)
Issued at 624 PM CDT Thu May 14 2020
VFR flight conditions expected through this evening, then will see
ceilings and visibilities lower with onset of showers and storms
after 05z Friday. When rain tapers off between 09z and 15z Friday
from north to south, MVFR ceilings will persist until mid
afternoon on Friday when conditions improve. Otherwise, south to
southwest winds will persist ahead of frontal boundary, then veer
to the northwest to north on back side of front. With front
progged to stall out Friday afternoon, confidence of where it will
stall out is low, so kept winds light and variable for TAFs along
I-70 corridor for remainder of forecast period.
Byrd
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...Flash Flood Watch until 5 AM CDT Friday for Audrain MO-Boone MO-
Callaway MO-Cole MO-Knox MO-Lewis MO-Marion MO-Moniteau MO-
Monroe MO-Pike MO-Ralls MO-Shelby MO.
IL...Flash Flood Watch until 5 AM CDT Friday for Adams IL-Brown IL-
Pike IL.
&&
$$
WFO LSX
Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
652 PM CDT Thu May 14 2020
.SHORT TERM...(This evening through Friday night)
Issued at 229 PM CDT Thu May 14 2020
A few showers could still pop up this afternoon into early evening
as the surface trough/weak cold front moves through the area.
Latest RAP analyses show 50-250 J/Kg of MUCAPE across the area,
with better values across the north, coincident with the better
forcing. Confined chance PoPs to the north half of the area and
stuck close to RAP/HRRR timing of things. Otherwise, look for
cloud cover to generally decrease tonight with the loss of diurnal
heating. Mild and dry weather will prevail on Friday as a weak
surface ridge noses in from the north.
.LONG TERM...(Saturday through Thursday)
Issued at 229 PM CDT Thu May 14 2020
Timing and strength of weekend short wave the main concern early
in the longer term. Then evolution of blocking pattern will
dominate with dry conditions with a gradual warm up into midweek.
Models have trended slower/deeper with the weekend short wave
trough. It deepens to southeast, carrying the surface low south of
the Minnesota/Iowa border Saturday night/Sunday. Forcing should
be sufficient for high end PoPs moving across the southern and
eastern CWA into Saturday night. Thunder threat appears to remain
low, mainly across the southern CWA. GEFS plumes suggest QPF of
0.25 northwest to 1 to 1.25 to the south and east CWA for the
event. With clouds and rain moving through, high temperatures will
struggle to warm through the 60s Saturday and will remain in the
50s over the southeast CWA where clouds/rain linger longest.
This initial short wave drops south/southeast and cuts off over
the southeast CONUS. A blocking ridge builds into the mid section
of the CONUS with rising heights progressing over the area through
midweek. The western CONUS trough may be slowed further, through
at least Wednesday because of the southeast CONUS cut off upper
low. The surface front may linger over the Dakotas region into
next Thursday. This, along with broad surface ridge over the Great
Lakes into the area will likely keep us dry through Wednesday.
Will work some lower end chance PoPs into mainly the western half
of the CWA for Thursday. We should be able to work some low/mid
80s into the area by Wednesday and Thursday. The trajectory of
flow/any real thermal ridge, remains best to the west so it may be
difficult to warm area to 90 degrees. Surface dewpoints remain
comfortable until midweek as the front/western trough moves
closer. Perhaps readings rising to the mid/upper 50s then.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 652 PM CDT Thu May 14 2020
VFR thoughout the period. Trough is moving across MN early this
evening with gusty wnw winds in its wake. It is associated with
isolated showers from east central to southwest MN which will end
this evening. Northwest winds will build in with the trough
passage, and with high pressure in North Dakota sinking southward,
there will be a gradient overnight with persistent nw winds
eventually turning north. Winds Friday will diminish during the
day as the high moves away and weakens.
KMSP...
One of the evening showers may drift over KMSP this evening, but
will more likely dissipate before reaching the airfield. There is
some potential for an hour or two of gusty winds to 20 knots with
trough passage. No other concerns.
/OUTLOOK FOR KMSP/
SAT...VFR morning then MVFR. Chc -SHRA. Wind E 5-15kts.
SUN...MVFR morning then VFR. Wind NE 10-15kts.
MON...VFR. Wind NE 5-10kts.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
&&
$$
SHORT TERM...
LONG TERM...DWE
AVIATION...TDK
Area Forecast Discussion
National Weather Service Spokane WA
858 PM PDT Thu May 14 2020
.SYNOPSIS...
More showery weather is expected for Friday. Saturday will
generally be dry and mild, but there could be some light rain
showers in the Casacdes by Saturday afternoon. Sunday will be wet
with widespread showers and thunderstorms. Wet weather will
continue for much of next week.
&&
.DISCUSSION...
A complex POP forecast for the rest of tonight but have made some
updates. The area is under a broad upper trough but with several
small lows helping to generate shower activity. There is also some
elevated instability over the region which will aid in keeping
some shower activity over the region overnight. Water vapor
satellite shows one circulation near the Grand Coulee area that
has been generating showers this evening around this area. Latest
HRRR guidance suggests this activity may lift north and west
overnight with an increasing threat of showers for the Okanogan
and Methow Valleys. Another circulation near The Dalles, OR is
aiding in shower development in the Yakima Valley into the Royal
City area. HRRR shows this activity will carry east overnight, but
with just isolated showers across the basin possibly increasing
slightly over the palouse. Yet a third area from near the ID/MT
border into the Coeur d`Alene area but has been breaking apart at
times and not organized at the moment. So far the 00z runs of the
GFS and NAM are overdone with the precipitation in this area. But
with the mid level flow backing to the southeast overnight
bringing in increased moisture a band of rain may set up over
portions of the ID Panhandle but low confidence as to how far west
the band will make it since current model runs are struggling to
capture the current details well. JW
&&
.AVIATION...
00Z TAFS: A band of showers is spreading into the Spokane- Coeur
d`Alene corridor associated with a surface low passing through the
region. The rain band will progress through the area through the
evening and will likely set up overnight across NE WA and N ID
Panhandle. Do keep -ra going for KCOE through the night. Drier air
behind the band is bringing rising cloud decks and VFR conditions
for the region starting around 17Z. /JDC
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 43 66 43 71 51 71 / 20 30 0 0 20 80
Coeur d`Alene 45 63 42 71 50 70 / 80 50 0 0 10 70
Pullman 40 63 42 70 51 69 / 30 40 0 0 20 70
Lewiston 46 68 45 76 56 76 / 30 40 0 0 10 70
Colville 42 70 42 74 49 71 / 30 50 10 0 30 80
Sandpoint 45 63 44 70 50 69 / 60 60 10 0 10 70
Kellogg 45 59 42 69 51 69 / 70 70 10 0 10 70
Moses Lake 43 73 45 77 54 74 / 20 0 0 0 60 70
Wenatchee 45 71 48 71 54 69 / 20 10 0 10 80 80
Omak 46 72 47 72 53 69 / 50 20 0 10 70 90
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
Area Forecast Discussion
National Weather Service Pueblo CO
1121 AM MDT Thu May 14 2020
.SHORT TERM...(Today and tonight)
Issued at 401 AM MDT Thu May 14 2020
Currently...
Quite a bit of low level moisture has worked westward across the
southeast plains of Colorado as 40 and 50(!) dewpts prevail across
the lower elevations. A sharp gradient in the moisture is noted
across the Raton Mesa as dwpts in this area were int eh teens. Mtns
and valleys were also in the teens. Associated with the moisture is
low clouds, and quite a bit of these have worked back west as they
were just moving into the Pueblo area around 3:00 AM. In the dry
air, skies were clear, except just east of the southern Sangres
where a band of wave clouds were noted.
On the larger scale, modest zonal flow aloft prevails over the
western 1/3rd of the CONUS, with several weak short waves noted in a
broad, very low amplitude trough over this region.
Today and Tonight...
Strong convection is likely to finally return to the region today.
Although the low level moisture will mix out some, sufficient cape
will be in place combined with the modest deep shear to allow for a
few strong storms to develop this late afternoon and evening over
the forecast area. Several runs of the high resolution guidance
indicates it will be a late show, and most of the stronger storms
will occur north of and along the US50 corridor, especially out in
Bent, Kiowa and Prowers counties. However some of the most recent
HRRR runs were showing some isolated activity forming off the Wets
and Southern Sangres. Given the above, believe storms will form
around Pikes Peak around 4 pm and then move generally east over the
plains. Storms will intensify as they move east with the strongest
activity occurring this evening along and north of US50. One or two
isolated storms will occur south of this area and will also move
east. They best chance for more significant rainfall will occur over
Bent, Prowers and especially Kiowa county this evening. This will
also be the location where the strongest storms will occur. Main
severe threats will be hail up to quarters and winds to 60 mph.
West of the mtns/plains interface are expected to be dry. Cant rule
out some isold dry thunder but for the most part it will be dry
across the higher terrain today.
Max temps today will be in teh 70s across the lower elevations of
the Pikes Peak region and L80s over the plains. San Luis Valley
should be in the 70s, with 50s and 60s mtns.
As discussed above, it will be a late show and expect storms to
still be going over the far eastern plains during the early morning
hours of Friday. The remainder of the region should be dry. Low
clouds will likely redevelop over the plains tonight. Min temps
tonight will fall to around 50F most of plains with 20s and 30s in
the mtns/valleys.
.LONG TERM...(Friday through Wednesday)
Issued at 401 AM MDT Thu May 14 2020
Friday and Saturday...An upper level trough is expected to continue
propagating across the northern Rockies into the northern Great
Plains Friday into Saturday, bringing another couple of rounds of PM
showers and storms to the region. Before the PM showers and storms
initiate each day, lingering precipitation from the previous night`s
convection is anticipated for the southeast plains each morning. The
PM convection is expected to begin over the mountains around midday
before spreading east to the plains. Friday still looks to have a
better chance for some stronger storms as moderate east to
southeasterly flow at the surface is expected to keep a steady
influx of low level moisture, resulting in increased instability.
Both deterministic and ensemble guidance continue to indicate that
CAPE values of around 1000 J/kg will creep into the region, while
bulk shear values of 30-40 kts are also expected across portions the
plains. These values, if they verify, should be sufficient enough to
also allow storms to strengthen and persist for a few hours. As the
trough moves away from the region on Saturday, there should be
enough instability remaining for another round of PM convection.
However, any convection that occurs Saturday is anticipated to be
more of the garden-variety type of storms at this time as
instability is expected to be weaker than Friday. Temperatures are
expected to generally be in the 70s both days over the high valleys
and plains.
Sunday into Tuesday...A fairly strong ridge is expected to build in
behind the exiting trough, which will bring more southwesterly flow
aloft to the region. This flow should promote warm and dry
conditions for much of the area, resulting in the potential for
critical fire weather conditions Monday and Tuesday in many
locations. That said, some remaining weak instability over the
mountains is expected to bring chances for isolated showers or
storms Sunday afternoon. An upper level low pressure system is also
anticipated to move onshore over northern California, bringing
another shot of isolated showers and storms to the area, mainly
along and west of the Sangre de Cristo Mountains. Temperatures warm
from the 80s on Sunday to the 90s for Monday and Tuesday across the
plains, while the high valleys should see temps in the 80s.
Wednesday...The upper-level low is anticipated to move north-
northeast into Idaho and Montana, keeping much of the precipitation
north of our area. Isolated PM showers and storms are possible over
the mountains, however. Temperatures are expected to cool about 5F
across the region.
&&
.AVIATION...(For the 18Z TAFS through 18Z Friday afternoon)
Issued at 1118 AM MDT Thu May 14 2020
KALS...VFR conditions through the next 24 hours. Westerly winds
will continue through this afternoon and early evening with gusts
near 28 kts possible.
KCOS and KPUB...VFR conditions this afternoon. Occasional gusts
to 25 kts may be possible out of the southeast. Thunderstorms will
be possible late this afternoon and evening at both terminals.
Reduced CIGS and VIS are expected with any storms that move over
the terminals. Upslope flow will lead to low stratus overnight
into Friday morning. Mozley
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...HODANISH
LONG TERM...CARLBERG
AVIATION...MOZLEY
...Update to aviation forecast discussion...
.SHORT TERM...(This evening through Friday)
Issued at 346 PM CDT Thu May 14 2020
Southwest to nearly zonal flow is occurring across the state as of
20Z ahead of a shortwave trough in the Pacific Northwest. At the
surface, circulation associated with the low can be seen in west
central KS on satellite with a small break in the cumulus field
along the frontal boundary, which is currently located along a line
from Abilene to Seneca. Temperatures have warmed to the upper 70s to
low 80s area-wide with dew points in the 60s. Eastern KS is still
under a cap, but this should continue to erode the rest of the
afternoon with the current conditions allowing plenty of
destabilization for storms late this afternoon into tonight.
The surface front should slowly progress eastward with CAMs
consistently showing storms initiating between Topeka and Emporia on
the leading edge of the boundary, most likely within the 21-23Z time
frame. RAP forecast soundings have shown CAPE of 3000-4000 J/kg in
areas along and southeast of the current boundary with shear of 25-
40 kts. The shear looks strongest after 00Z when the LLJ strengthens
to 35-40 kts. That being said, storm mode looks messy with
supercells possible initially before outflow boundaries develop and
storms congeal into a line and slowly move southeast. Hodographs
continue to show good veering in the low levels, so a few tornadoes
cannot be ruled out with supercells; however, the initially weaker 0-
6 km shear makes this threat more questionable. Large hail and
damaging winds will be a good possibility with steep mid-level lapse
rates. The HRRR has been consistent in keeping a strong line of
storms in east central KS late this evening and potentially
lingering into the overnight hours along the southern border of the
CWA. This is also consistent with models bringing the boundary south
of the area by 12Z, which is slower than indicated yesterday. Based
on this, have expanded the Flash Flood Watch to include Lyon and
Osage Counties. Rainfall amounts of 1-3 inches with locally higher
amounts are still possible in this area through Friday morning.
Storms should dissipate by sunrise Friday morning with some clearing
in northern KS while east central areas likely stay cloudy. The
front appears to move back north again very slightly into the far
southeastern counties of the CWA during the day. An additional round
of storms is possible in this area perhaps in the late afternoon,
but more so by the evening and overnight hours. The NAM tends to
keep the area dry until early Saturday whereas the EC/GFS start to
bring precipitation into the area late in the afternoon. Some
uncertainty in severe weather potential exists due to this
difference in the models, although forecast soundings do show MUCAPE
up to 1200-1500 J/kg and shear up to 40 kts, which would support
elevated storms capable of hail and wind hazards.
.LONG TERM...(Friday night through Thursday)
Issued at 346 PM CDT Thu May 14 2020
The surface boundary will continue to slowly push back north into
Saturday with showers and thunderstorms still possible on and off
for much of the day. The better upper level support arrives with a
more amplified trough moving across the Northern Plains as well as a
southern stream trough across TX. No severe weather is expected at
this time, but additional rainfall could exacerbate flooding in
areas that already receive heavy rainfall tonight.
Dry weather returns by Sunday as an amplified ridge moves across the
area ahead of a deep trough coming onshore from the Pacific.
Temperatures will warm well into the 80s by midweek before the next
chance of rain next Thursday, although model differences keep low
confidence in this at this point.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 632 PM CDT Thu May 14 2020
Thunderstorms have developed ahead of a sfc boundary at issuance
time. Storms are expected to be near or impact terminals for the
first few hours of this period, before moving south of sites late
this evening/early tonight. Winds shift behind the boundary to the
north and northeast tonight, and will then become predominately
easterly tomorrow. Additionally, a few hours of MVFR CIGS are
possible during the morning hours at the TOP airports, but VFR
should prevail at KMHK.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
Flash Flood Watch through Friday morning for KSZ040-054>056-058-
059.
&&
$$
SHORT TERM...Picha
LONG TERM...Picha
AVIATION...Teefey
Area Forecast Discussion
National Weather Service Tulsa OK
946 PM CDT Thu May 14 2020
...UPDATE...
.DISCUSSION...
Isolated thunderstorms have developed near the frontal
boundary across northwest OK this evening, although
relatively weak wind fields have resulted in a very slow
eastward progression. Will keep an eye on these storms as
its not out of the question they could approach parts of
northeast OK. Convection continues to organized across
eastern KS, and recent runs of the HRRR support a late
arrival of storms (after 08Z) into northeast OK.
Going forecast appears to be in reasonable shape and no
update is planned at this time.
&&
.PRELIMINARY POINT TEMPS/POPS...
TUL 67 77 65 79 / 50 80 60 60
FSM 68 79 66 80 / 20 80 50 70
MLC 70 82 67 78 / 10 70 60 70
BVO 65 75 64 80 / 70 90 60 60
FYV 64 74 64 77 / 70 90 50 70
BYV 62 73 63 77 / 80 80 50 70
MKO 68 77 65 77 / 30 80 60 70
MIO 64 73 63 78 / 80 90 60 60
F10 68 78 65 77 / 20 70 60 60
HHW 69 83 67 77 / 10 40 60 80
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...Flash Flood Watch from 1 AM CDT Friday through Friday afternoon
for OKZ054>063.
AR...Flash Flood Watch from 1 AM CDT Friday through Friday afternoon
for ARZ001-002.
&&
$$
SHORT TERM...18