Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 05/21/20
Area Forecast Discussion
National Weather Service La Crosse WI
1034 PM CDT Wed May 20 2020
.SHORT TERM...(Tonight through Thursday)
Issued at 205 PM CDT Wed May 20 2020
Forecast concerns in the short term will be the return of clouds and
their impact on temperatures.
Sunshine returned to much of the area today with high temperatures
in the 70s. Where clouds have been lingering though, only 60s were
noted. The closed h5 low over the Tennessee River Valley is progged
to retrograde westward a little, then lift northward toward Indiana.
Meanwhile, the closed h5 low over Idaho will lift northward toward
Alberta/Saskatchewan Canada while sending some energy eastward into
the Plains. This pattern pinches off the ridge over the local area
and brings low clouds back at us from the southeast already tonight.
The RAP shows the low clouds thinning, however h85 moisture
increases through the morning with clouds re-developing. With the
increase in clouds for Thursday, did go cooler with highs in the 60s
to lower 70s.
.LONG TERM...(Thursday Night through Wednesday)
Issued at 205 PM CDT Wed May 20 2020
Incoming mid-level trough, weak lift and increasing moisture over
the area Thursday night into Friday will produce widespread clouds
along with some scattered shower activity. Plan on lows Thursday
night in the 50s with highs Friday topping off in the lower to
middle 70s.
Look for that trough to continue lifting northeast across the area
Friday night into Saturday for continued scattered showers and
perhaps a few embedded thunderstorms. Despite cloud cover and
precipitation, models are still indicating highs Saturday in the
70s.
Another mid-level trough/surface cold front moves into the region
Sunday/Sunday night/Memorial Day for yes, more showers and
thunderstorms. Cape looks to be generally in the 1500-2500J/kg range
but the bulk shear looks fairly weak in the 15-20kt range, so
widespread severe weather is not expected. Plan on highs in the 70s
to lower 80s.
Upper flow continues to look active through Wednesday with the
potential for a couple more troughs to rotate through the region. So,
shower/thunderstorm chances remain in the forecast.
&&
.AVIATION...(For the 06Z TAFS through 06Z Thursday night)
Issued at 1034 PM CDT Wed May 20 2020
Stratus continues to inch back northward into the region, likely
reaching RST by 06Z while LSE will wait until late tonight or even
after sunrise for clouds over northern Illinois to work back
across that location. Clouds may attempt to thin at times into the
day Thursday, but at the moment, confidence remains fairly low
regarding if any locations will completely scatter out the ceiling
or whether MVFR conditions will prevail through the entire day at
either LSE or RST. Regardless, additional stratus appears likely
to redevelop over the area again into Thursday evening and night,
with MVFR ceilings again expected. Winds will remain from the
southeast 5-15 knots the next 24 hours.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
IA...None.
&&
$$
SHORT TERM...CZ
LONG TERM...DAS
AVIATION...Lawrence
Area Forecast Discussion
National Weather Service Binghamton NY
1007 PM EDT Wed May 20 2020
.SYNOPSIS...
High pressure will continue to bring very quiet weather with
plenty of sunshine through Thursday. A weak low pressure system
will bring the next chance of scattered showers Friday
afternoon into Saturday.
&&
.NEAR TERM /THROUGH THURSDAY NIGHT/...
1005 PM update...
Light winds and clear skies will allow temperatures to fall into
the upper 30s and lower 40s in most locations by morning. We
still expect isolated frost near sunrise, but we diminished
coverage as temperatures are running above plan, and the latest
Consshort and HRRR came in a few degrees warmer than the NBM.
Previous discussion...
High pressure continues to bring very quiet weather with plenty
of sunshine to the region. This will continue through the entire
near term forecast period.
Clear skies and relatively light winds will set up a
radiational cooling scenario, leading to chilly low
temperatures. Lows are expected to be in the 30s across the
majority of the region, with lower 40s in the Finger Lakes and
Central New York. This will likely be cold enough for some
patchy frost to form, especially in the valley locations of the
Southern Tier of NY and Northeast PA. Surface winds look to be
just high enough to likely prevent the formation of widespread
frost and therefore not issuing a Frost Advisory with this
forecast package.
Another spectacular spring day is expected for Thursday with
abundant sunshine and highs in the upper 60s to mid 70s. Clouds
begin to increase from southwest to northeast Thursday night,
which will prevent temperatures from falling as much as tonight.
Lows are expected to be in the mid 40s to mid 50s.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
320 pm update...
Main concerns in the short term remain focused on the next chance of
rain showers and even a few thunderstorms Friday night through
Saturday evening.
Cutoff upper low over the Tennessee Valley that has been nearly
stationary this past week will finally move to the e/ne through the
mid Atlantic region Friday and Saturday. As this occurs the
ridge of high pressure and dry air mass over the Northeast will
get shifted to the east and a strong push of deep moisture will
advect north along the coast into NY and ern PA. Cloud cover
will increase along with chances for rain Friday night and
Saturday morning. The best chance of rain through Sat morning
still appears to be from the southern tier of NY into the
Catskills and south into PA.
Temperatures will rise into the 70s on Saturday with sfc dew
points jumping up into the upper 50s. This added humidity will
allow for enough instability to trigger a few thunderstorms
Saturday afternoon and early evening. The overall forcing aloft
does appear to be fairly weak, so the threat for strong to
severe storms looks to be low. Ridging aloft moves in quickly
late Saturday into Sat night behind the departing system, which
will act to suppress any lingering showers rather quickly.
Temperatures remain mild into Saturday night with overnight lows
only down into the lower to mid 50s.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
320 pm update...
A strong blocking pattern appears to set up again over the
eastern quarter of the US...mainly along and east of the
Appalachian Mtns. This will keep most of our forecast area on
the dry side through the Memorial Day weekend and maybe even
beyond. Cannot rule out an afternoon popup shower, but overall
conditions appear dry. There are some uncertainties with respect
to how far east the convection along the outer fringe of the
upper ridge makes it...potentially into wrn and/or nrn NY. So,
will remain consistent with the previous forecast and keep some
slight chance pops for the far eastern or nern sections of the
forecast area...and basically dry elsewhere through Tuesday. By
Wednesday...there is slightly higher confidence that the
convection makes a stronger push eastward...so have chance pops
nudging to the I-81 corridor by Wed.
Temperatures will continue a slow warming trend through the end
of the weekend and into next week with highs on Sunday in the
mid to upper 70s...and into the upper 70s and lower 80s by
Wednesday.
&&
.AVIATION /02Z THURSDAY THROUGH MONDAY/...
VFR conditions will dominate through the entire TAF period.
Southeast winds will diminish this evening and become light.
Outlook...
Thursday Afternoon Through Monday: Mainly VFR. Some scattered
showers Friday night and Saturday.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...None.
NY...None.
&&
$$
SYNOPSIS...BJG
NEAR TERM...BJG/DJP
SHORT TERM...BJT
LONG TERM...BJT
AVIATION...BJG/DAB
Area Forecast Discussion
National Weather Service Grand Junction CO
800 PM MDT Wed May 20 2020
.UPDATE...
Issued at 800 PM MDT Wed May 20 2020
Strong winds have diminished across the region and relative
humidities are beginning to rebound. Therefore, the Red Flag
Warnings will be allowed to expire at 8 PM.
UPDATE Issued at 654 PM MDT Wed May 20 2020
Though breezy conditions will continue for the next hour or so,
wind gusts are not expected to reach Advisory criteria. Therefore,
the Wind Advisory will be allowed to expire as planned at 7 PM.
&&
.SHORT TERM...(Tonight through Thursday night)
Issued at 243 PM MDT Wed May 20 2020
If you`re reading this, no, you don`t live in Wyoming though
you`d think so after the windy days we`ve been experiencing. This
should all come to an end tomorrow but until then, the gusty winds
continue as the low pressure to our northwest keeps that pressure
gradient tight and a departing jet streak moves to the High
Plains. HRRR and other short range guidance keeps wanting to put
some weak convection over eastern Utah and to a lesser extent the
northern valleys later this afternoon and evening. Current radar
imagery does show some convection firing over central Utah in
response to a spoke of energy rotating around the low. If this
holds together and the spoke continues its eastern trajectory, we
just might see some of that convection. Don`t anticipate any
precip hitting the ground as the lower levels remain very dry. If
some convection does fire, expect some really gusty winds from the
outflow. Winds will die down as we head towards sunset. Clear
skies will allow some decent radiational cooling to kick in which
will drop temperatures to freezing, if not a bit below. Areas
favored for these abnormally cold lows will be the Craig area and
the southern valleys from Cortez through Durango up in to Pagosa
Springs. Debated on issuing a freeze warning but these temps will
be spotty at best and will occur an hour or two before sunrise and
won`t last long. That being said, if you do have any sensitive
vegetation, wouldn`t be a bad idea to cover it overnight or bring
it in. Don`t forget about your pets either!
A relatively calm day expected tomorrow as zonal flow sets up across
the CWA. Mostly sunny skies expected as temperatures stay about 5
degrees cooler than normal. A few afternoon gusts remain possible
but more on the order of 20 to 25 mph with a few higher gusts up
north, closer to that low pressure. Enjoy the day because it looks
like more wind is on the way.
.LONG TERM...(Friday through Wednesday)
Issued at 243 PM MDT Wed May 20 2020
Models remain consistent with subtle differences in intensity and
placement of an upper-level trough moving into the CWA on
Friday. Q-vectors were supporting surface convergence Saturday
night into Sunday night however, RH values are currently
forecasted between 45-50% suggesting partly cloudy skies with a
low chance of shower activity for the higher elevations. Dry
conditions will continue to prevail for the valleys.
Friday into Saturday...Moderate winds, cooler temperatures and
dry conditions will prevail as an upper-level trough moves through
the CWA Friday into Saturday. Saturday into Sunday could see the
potential for stronger gusts from the southwest as a portion of
the jet stream moves through raising some concern for critical
fire weather conditions.
Sunday into Monday...The upper-level trough moves out of the CWA
fairly quickly allowing moisture to come in from the Pacific
Northwest this however, could favor higher elevation showers.
Winds will be moderate at times from the west-northwest
transitioning to a more northwest direction Sunday night into
Monday as an intensifying upper-level ridge drives the trough out
of the CWA. This will allow warm temperatures, drier conditions
and lighter winds compared to what were experienced earlier in the
forecast period. Nonetheless, critical fire weather conditions
will remain of some concern.
Tuesday into Wednesday...Weather conditions remain questionable as
the forecast is a week away, however there are slight indications
for precipitation favoring mostly the northern part of the CWA.
Models were suggesting winds will be out of the west and gusty at
times with mostly dry conditions prevailing for the valleys.
&&
.AVIATION...(For the 00Z TAFS through 00Z Thursday evening)
Issued at 510 PM MDT Wed May 20 2020
Wind gusts of 25 to 35 knots will persist at most TAF sites
through 04Z this evening when stronger winds diminish with
sunset. Light virga showers will also be possible during this
timeframe and may enhance already strong surface winds. Widespread
VFR conditions are expected overnight and on Thursday with passing
clouds, though CIGS will remain above ILS breakpoints. Breezy
conditions will redevelop after 18Z Thursday.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...None.
UT...None.
&&
$$
UPDATE...MMS
SHORT TERM...TGR
LONG TERM...JPK
AVIATION...MMS
Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
1038 PM EDT Wed May 20 2020
.SYNOPSIS...
A large upper low will linger over the Tennessee Valley Region
into Thursday as it weakens while generating several rounds of
moderate to heavy rain across much of our region. This pattern has
the potential to produce more significant rainfall and flooding over
parts of the region. The low will finally start to move away by
late Thursday and Thursday night. On Friday, one more disturbance
will move across the region. We should see a return to more typical
late spring weather over the weekend.
&&
.NEAR TERM /THROUGH THURSDAY/...
As of 1035 PM EDT Wednesday: Forecast is on track. Still watching
the feature discussed below which may be a bit less of a concern
based on latest radar/model trends. Will continue to monitor.
Otherwise, one feature to watch is a mesoscale convective feature
across southern reaches of coastal South Carolina that is being
triggered by low level convergence between onshore flow and a nearly
stationary front. Outflow from this feature combined with moist
southeasterly flow may bring the next round of heavier rain to the
Upstate of South Carolina after midnight and to portions of the the
mountains before sunrise. The HRRR (which currently matches this
feature best) shows upscale growth with this feature intensifying as
it crosses I-85 into the mountains. Deep layer moisture to 500 mb
and perhaps some elevated instability would support heavy rainfall
rates of a half of an inch per hour, locally up to an inch per hour
and could put down a quick inch or so of rain within a couple hours.
This could easily aggravate ongoing flooding as well as introduce
new flash flooding to the region should these heavier rates
materialize. We will watch this potential closely as the evening
wears on.
Expect periods of showers to move northward across the area as
moisture continues to infiltrate in. Per latest guidance, the
notable upper closed low is progged to meander over TN through
tonight before slowly retreating to the NW on Thursday with the sfc
low remaining to the south and the sfc wedge slowly retreating on
Thursday. Could not entirely rule out a few rumbles of thunder the
rest of today, but confidence is low attm. Min temperatures will
remain just below normal.
On Thursday, CAMs continue to depict scattered showers across
western NC and into the Midlands throughout the rest of the period.
Despite rainfall becoming isolated in nature across portions of the
area, with runoff from rainfall over the past few days as well as
ongoing flooding, expect flooding concerns will continue. The Flash
Flood Watch currently in effect may need to be extended past
Thursday morning. Max temperatures on Thursday will be warmer than
today with wedge erosion, but still just shy of normal.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
As 215 PM EDT Wednesday: The short term begins Thursday night with
the upper low still hovering over the southern Appalachians, though
the main area of focused heavy rainfall associated with it will have
moved out of the area. Friday will present a bit of a lull in
rainfall during the day, though an upper shortwave will move through
in the afternoon and with plenty of moisture still in place over the
area, some enhanced diurnal convection will likely break out across
the area. PWATs will still be on the order of 1.5-1.6" and any
storms that do develop will likely be accompanied by heavy rainfall
rates, potentially exacerbating any lingering flooding issues. The
other factor to consider Friday afternoon is severe potential with
any storms that do develop - deep layer speed shear still looks like
it will be on the order of around 40kt with forcing provided by an
upper shortwave moving across the area. The question that remains is
instability - guidance has been inconsistent with the extent
spatially and quantitatively of the instability that may develop,
ranging from almost none to close to 2000 J/kg in the southern
Upstate. The extent of the severe weather threat will probably have
to be more of a day-of assessment, as cloud cover during the day on
Friday will make all the difference in the development of instability.
The upper low will finally shift just a little bit eastward on
Saturday, enough to remove the large-scale forcing for ascent
driving the widespread heavy rainfall. The tail of a surface cold
front will remain over the area, though, and scattered diurnal
convection is expected.
As of 321 AM EDT Wednesday: The model guidance shows the cutoff
low finally but slowly on the move away from the fcst area, altho
we will remain under the influence of its cyclonic flow. More
importantly, at daybreak on Thursday, the plume of tropical moisture
will also be on the move across the western Piedmont/foothills of
NC. Unfortunately, this might be too late, and one might anticipate
the Flash Flood Watch to be extended over parts of the fcst area
through the daylight hours on Thursday to account for what looks
like an ongoing threat at least over the area east of Highway
321 in the morning. Very high precip probs will be maintained in
that area, and across the rest of the mtns as well as wraparound
moisture/precip remain across that region well into the day. We
should finally see the threat wane late Thursday as the mid/upper
level dry air wraps in across the rest of the fcst area while the
upper low moves toward the OH Valley. Temps should rebound but
remain below normal. On Thursday night, we might finally get a
break with the forcing having exited to the northeast, so precip
probs tail off considerably, but not entirely. Friday looks like
yet another busy day, what with so much lingering moisture to work
with. The guidance shows a short wave coming through an upstream
ridge Thursday night and then getting entrained into the cyclonic
flow around the departing upper low on Friday. That scenario brings
this forcing overhead during peak heating, which would support
numerous showers/storms across the mtns/foothills and a chance
everywhere else. Fortunately, buoyancy appears to be rather limited,
so we do NOT appear to have an appreciable chance at strong/severe
storms. Temps should climb back to normal. Finally, in the wake of
this short wave Friday night and the upper low having moved even
farther away, dare we say that we might start to briefly dry out
after midnight? One can hope at that point.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
As of 145 PM EDT Wednesday: Long-overdue pattern change is on tap
for the extended forecast. The upper low finally moving out of the
area will give way to upper ridging by Saturday night/Sunday, though
at the surface a trailing front will get hung up over the area, and
surface moisture lingering over the area will keep conditions
favorable for what will likely be a more diurnal pattern of showers
and thunderstorms. PWATs will be a bit lower than they have been the
past week, though a generally muggy airmass will still be in place
through the balance of the extended. The only thing lacking will be
a focused forcing mechanism, though with at least 1000+ J/kg of
instability each afternoon, convection will be widespread in the
mountains and scattered in all other areas and will support decent
localized rain rates. Temps will generally be around 5 degrees above
climo through the middle of next week.
&&
.AVIATION /03Z THURSDAY THROUGH MONDAY/...
At KCLT and Elsewhere: Below normal confidence in 00Z TAFs related
to timing of cigs/vsbys and decreasing shower activity. Enough
elevated and weak instability may develop for some areas between 04Z
and 10Z and linger into Thursday for isolated TSRA. Not high enough
confidence for TAF inclusion at this time. A diurnally driven
easterly llvl jet may support weak to moderate LLWS at times through
12Z.
Outlook: A building ridge of high pressure will support a trend
towards diurnally driven SHRA/TSRA heading into this weekend.
Confidence Table...
02-08Z 08-14Z 14-20Z 20-00Z
KCLT High 94% Med 79% Med 77% Med 79%
KGSP High 92% High 94% High 94% High 80%
KAVL High 87% High 82% High 90% Med 76%
KHKY High 98% High 94% High 90% Med 78%
KGMU High 92% High 90% High 93% High 84%
KAND Med 69% High 89% High 95% High 100%
The percentage reflects the number of guidance members agreeing
with the scheduled TAF issuance flight rule category. Complete hourly
experimental aviation forecast consistency tables are available at
the following link:
www.weather.gov/gsp/aviation
&&
.HYDROLOGY...
Very wet near-term antecedent conditions are setting the stage
for a hydrologically active Thursday with widespread forecasted
rainfall of 2-4+" expected over saturated upper soils following
several rounds of heavy rain since Monday. The heavy rainfall
already observed, exceeding 5-6 inches in some locations along and
near the Blue Ridge Escarpment and Upstate SC, has caused
significant rises on area streams. While many small streams have
crested and are beginning to recede, flows remain elevated heading
into Thursday. Though much of the area was dry over the two weeks
leading up to this event, the entire region has seen a wet winter
and early spring with above-normal rainfall.
Given these antecedent conditions and forecasted rainfall, WPC`s
Moderate Risk for excessive rainfall again tomorrow is well placed
and warranted.
With a lower threshold for excessive runoff and extremely low flash
flood guidance, new rapid stream rises and higher crests will be
easier to achieve with any heavy rainfall that occurs tonight into
tomorrow morning. Minor flooding along the Blue Ridge Escarpment and
adjacent foothills of North and South Carolina has already occurred
today, and is anticipated closer to the Charlotte Metro area later
tonight into Thursday morning. Isolated to scattered areas of more
significant (Moderate) flooding potentially impacting several homes
and businesses are possible in areas that have already seen
excessive rainfall, especially along and adjacent to the Escarpment
from Henderson and Polk counties north to Avery and Caldwell
counties, but such impacts cannot be ruled out further east and
south into the Piedmont, especially near urban areas, including
Charlotte.
As always, it will take many hours for streams to rise, crest, and
recede so flooding could persist well after the rainfall ends.
Larger streams will be the last to respond and recede from
excessive runoff; therefore, rivers like the Broad, Catawba,
and SF Catawba may see flooding persist well into Thursday.
Moderate flooding along these mainstem rivers, which includes
structural flooding, is possible so it will be important to monitor
forecasts (https:/water.weather.gov/ahps2/forecasts.php?wfo=gsp)
and Warnings for the latest information if conditions deteriorate.
Given the potential for high rainfall rates and event-total (since
Monday) rainfall amounts exceeding 10 inches in isolated locations
along and adjacent to the Escarpment, the threat for landslides is
also increasing. Residents in areas prone to landslides are urged
to review the GSP Public Information Statement for preparedness
information and be prepared to act if a Flash Flood Warning is
issued for your area.
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...None.
NC...Flash Flood Watch until 8 AM EDT Thursday for NCZ033-035>037-
049-050-053-056-057-064-065-068>072-082-501>510.
SC...Flash Flood Watch until 8 AM EDT Thursday for SCZ002-003-
005>010-013-014.
&&
$$
SYNOPSIS...DEO
NEAR TERM...65/12
SHORT TERM...17
LONG TERM...17
AVIATION...65
HYDROLOGY...
Area Forecast Discussion
National Weather Service Northern Indiana
709 PM EDT Wed May 20 2020
.SYNOPSIS...
Issued at 236 PM EDT Wed May 20 2020
Mostly cloudy skies, cool temperatures and low chances for a few
light showers or sprinkles will persist through Friday. The holiday
weekend will then feature warmer temperatures and periodic chances
for showers and thunderstorms. High temperatures by Sunday and
Monday should reach the lower to middle 80s.
&&
.SHORT TERM...(This Evening through Friday)
Issued at 236 PM EDT Wed May 20 2020
Stubborn upper low stalled over TN will finally release slowly
back nnw to near the OH/KY border by later tomorrow, then ene into
central OH by Friday as rex block weakens and height falls
overspread the Plains. The result locally will be more of the same
through the end of the week...mostly cloudy with non-zero chances
for a few sprinkles or light rain showers mainly south and east
of Fort Wayne. Lacking airmass change in deep easterly
tropospheric flow on the northern fringe of this feature will
result in only a gradual uptick in temps into Thur-Fri.
&&
.LONG TERM...(Saturday through Wednesday)
Issued at 236 PM EDT Wed May 20 2020
Developing low level southwesterly flow, between a building Eastern
US upper ridge and a trough approaching the Upper Midwest, will
allow higher theta-e air to overspread this weekend into early
next week. Temps will respond nicely in this regime with highs
near 80F Saturday and into the low-mid 80s thereafter. Chances for
showers/storms will also enter the forecast during these periods
given increasing moisture and potential for convectively aided
shortwaves to track into the Lower Great Lakes. Predictability
with these smaller scale features is low at this range, with
higher confidence in rain/storms favored into Monday and Tuesday
as a frontal boundary eases in from the west.
&&
.AVIATION...(For the 00Z TAFS through 00Z Thursday Evening)
Issued at 710 PM EDT Wed May 20 2020
Moisture within rexed cyclone over north central TN to lallygag
northward through the terminal forecast period. Additional weak
shortwaves within mixed moist boundary layer may provide light
rain shower potential at KFWA per latest HRRR by midday Thursday.
Point chances too low however to warrant more than VCSH at this
time. Greatest concern would be ceilings dipping below
fueling/alternate at KFWA with better column saturation and more
proximal to decaying cyclone.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...Lakeshore Flood Advisory until 9 PM CDT this evening for INZ003.
MI...Lakeshore Flood Advisory until 10 PM EDT this evening for MIZ077.
OH...NONE.
LM...NONE.
&&
$$
SYNOPSIS...Steinwedel
SHORT TERM...Steinwedel
LONG TERM...Steinwedel
AVIATION...Murphy
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Area Forecast Discussion
National Weather Service Norman OK
1013 PM CDT Wed May 20 2020
...New AVIATION...
.SHORT TERM...
(This evening through Thursday)
Issued at 230 PM CDT Wed May 20 2020
Current temperatures are mainly in the mid to upper 70`s over the
CWA with a stratus deck stretched south/east of a line from near
Gage to Chickasha to Durant. Latest CAMS suggest thunderstorms
moving into SW OK and western north TX after 00Z Thursday, with
the HRRR trending a bit later - after 03Z. Storms that reach this
area are forecast to weaken and dissipate overnight, and will
generally remain south/west of I-40/I-35.
The upper level ridge overhead will move east ahead of a mid-
level longwave trough, which is currently centered near western
Idaho. A shortwave trough will rotate around the base of the
longwave trough with a mid-level vorticity maxima progged to
track across New Mexico tomorrow. Late tomorrow afternoon/evening,
there is a chance for thunderstorm development near the
intersection of the surface low and dry line as the shortwave
approaches. Storms that develop over the panhandles may move into
northwest Oklahoma and bring the risk of large hail and damaging
wind gusts. The tornado threat will be very low.
Thompson
&&
.LONG TERM...
(Thursday night through next Tuesday)
Issued at 300 PM CDT Wed May 20 2020
For Thursday night, a mesoscale convective complex (MCS) is
forecast to develop across Kansas. The complex is expected to move
east-southeast and could affect northwest/north central Oklahoma
into early Friday morning.
For Friday, the evolution of mesoscale features will modulate the
risk of convection and the attendant risk of severe
thunderstorms. The remnant outflow boundary from the
aforementioned MCS could be a focus mechanism for redevelopment on
Friday. With a modest low-level jet, convection may even continue
to redevelop across northern Oklahoma Friday morning and move
southward while gradually intensifying during the day (i.e., there
may not be a lull in the convection). The outflow boundary may
also intersect a dryline to the west, which is another area to
watch for convection.
For Saturday, showers and thunderstorms may develop along a
dryline across western Oklahoma as a shortwave trough lifts
northeastward into the Plains. The southern periphery of the
shortwave trough will clip western Oklahoma.
For Sunday, the longwave trough is forecast to eject into the
Plains. Widespread showers and thunderstorms are expected and may
persist into the overnight hours. Heavy rainfall may become a
hazard during this period.
Forecast confidence decreases into early next week as there is
uncertainty on the evolution of the shortwave trough. Most
guidance suggests that the trough will eventually close-off;
however, there is uncertainty where the low will close-off. For
now, opted to leave moderate chance of showers/storms into early
next week with a moist airmass staying in place.
Mahale
&&
.AVIATION...
(00Z TAFS)
Issued at 946 PM CDT Wed May 20 2020
MVFR ceilings will persist and spread more northeast over nearly
all of central and western Oklahoma Thursday morning. Isolated
showers and thunderstorms may continue to move eastward into
southwestern Oklahoma overnight. Rain and storm chances persist
and spread northeastward during the day Thursday.
&&
.PRELIMINARY POINT TEMPS/POPS...
Oklahoma City OK 63 78 65 85 / 20 50 50 40
Hobart OK 63 85 63 90 / 40 30 40 10
Wichita Falls TX 66 85 66 90 / 50 40 30 20
Gage OK 61 84 60 85 / 20 30 40 10
Ponca City OK 61 75 63 83 / 20 70 70 60
Durant OK 64 80 67 85 / 30 50 40 40
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...None.
TX...None.
&&
$$
SHORT TERM...01
LONG TERM....10
AVIATION...09