Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 04/14/21
Area Forecast Discussion
National Weather Service Denver/Boulder CO
730 PM MDT Tue Apr 13 2021
.UPDATE...
Issued at 730 PM MDT Tue Apr 13 2021
Model differences are quite extreme in the near-term, both in
winds and precipitation. However, higher resolution models are
assessing and seeing the northwesterly winds on the west side of
the Denver Cyclone positioned just east of DIA, which is
effectively helping to downslope out a lot of the metro areas.
These strong northwesterly winds, gusting 15 to 30 mph should
begin to taper off. Looking at the VAD wind profile, it`s really
only the low level winds that are NW, with SE showing up just
right around 3000 feet AGL. The high resolution models however,
have the northwesterly winds remaining all evening and into the
night, but becoming much lighter. This would tend to downslope
the metro areas early on when they are stronger, then the SE winds
just off the surface may be able to overcome and be able to
produce precipitation. Will decrease PoPs early this evening, then
have them increase. Still interesting to have the GFS and NAM so
much heavier than the RAP and HRRR. Winds are starting to relax
near the base of the foothills and radar reflectivities are
beginning to fill in a bit, so believe this is the right trend for
the forecast.
&&
.SHORT TERM...(This evening through Wednesday)
Issued at 250 PM MDT Tue Apr 13 2021
Satellite and radar pictures are indicating convective looking
showers developing over the mountains and foothills at this time.
Models keep west and southwesterly flow aloft tonight and Wednesday.
Concerning the synoptic scale energy; there is upward vertical
velocity progged for the CWA tonight and Wednesday. The the lower
levels, east to southeasterly boundary layer winds are expected
tonight and Wednesday. This flow is actually indicated up to the
divide on Wednesday. Moisture is pretty deep tonight for most of
the CWA. On Tuesday it is relegated mainly to the lower levels.
For pops, will go with "likely"s and better for the mountains
tonight, with just "likely"s on Wednesday. For the plains 30-60%
will suffice tonight, with 0-30%s on Wednesday. The eastern plains
should be dry on Wednesday afternoon. The orographic enhancement is
not great for the mountains tonight or Wednesday. As far as snowfall
amounts go, the current highlights are adequate for the mountains
and northern foothills. Lesser amounts for the adjustments plains
with no highlights needed. The cooler temperatures; cooler temperatures
than normals, are expected to continue for Wednesday`s readings.
.LONG TERM...(Wednesday night through Tuesday)
Issued at 244 PM MDT Tue Apr 13 2021
The week will be characterized by cool temperatures and repeated
rounds of precipitation. On the plains, highs will generally be in
the low 40s to low 50s F and lows will be in the low 20s to mid
30s F. The high country should generally be only about 10 degrees
cooler. This will mean persistent snow for the higher elevations
and rain or mixed precipitation turning to snow through the
evening for most of the lower elevations, often to include the
mountain valleys and parks.
Light, scattered showers will be ongoing across the area
Wednesday night into Thursday, though decreasing between waves.
Scattered showers will persist early Thursday and should be
increasing again into Thursday night as the upper trough to our
west advances over Colorado. Model agreement on the timing and
placement of the trough continues to improve, putting it directly
over northeast Colorado by Friday morning. Confidence continues to
increase in widespread, moderate precipitation Thursday night
through Friday. QG forcing for ascent should maximize late
Thursday night, with subsidence being replaced by moderate lift of
10 to 20 mb/hr. Models suggest persistent moderate to weak ascent
for northeast Colorado through Saturday morning. If the system
comes in further south, increased moisture advection and upslope
flow would support heavier snowfall across much of the area. At
this time, the forecast trend is towards the more northern track
however. Forecast snow amounts are now just marginal for a Winter
Weather Advisory for the eastern plains Friday morning.
Uncertainty remains concerning temperatures and resulting
accumulations, especially on pavement and therefore travel
impacts. We will continue to monitor forecast snow amounts and
probable impacts.
Snowfall should gradually diminish again Friday afternoon through
Sunday morning, with some precipitation ongoing in the high
country, mainly the southern mountains and foothills. The trough
seems to stall and increase in positive tilt as another trough
approaches from the north in northwest flow aloft early next week,
which might just clip northeast Colorado.
&&
.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 730 PM MDT Tue Apr 13 2021
The strong northwesterly winds have been downsloping most of the
Front Range urban corridor and out to DIA, increasing ceilings and
negating precipitation. High resolution models had this well, and
have the NWrlys decreasing over the next few hours, which should
allow for the SErlys above to be able to increase upslope flow and
thereby lower ceilings and allow precip to fall, allowing ceilings
to get into MVFR category. There does seem to be an overall trend
for winds to become southeasterly after midnight, which should
deepen the moist airmass and let ceilings fall even more into the
IFR category. There are discrepancies on how much snow will fall
and where, with the GFS and NAM showing more widespread snow
through the night, whereas the HRRR and RAP show it hugging
closer to the foothills. This may mean we have VIS too low in DEN
but closer to right for BJC. Still uncertain how the CIGS and VIS
will react at APA with southeasterly winds, since this could
downslope slightly from the Palmer Divide.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory until 6 AM MDT Wednesday for COZ033>035.
&&
$$
UPDATE...Kriederman
SHORT TERM...RJK
LONG TERM....Direnzo
AVIATION.....Kriederman
Area Forecast Discussion
National Weather Service Caribou ME
1102 PM EDT Tue Apr 13 2021
.SYNOPSIS...
A ridge of high pressure will persist over the area and slowly
weaken through Thursday. Low pressure will approach Thursday
night, cross the Gulf of Maine through Friday, then exit across
the Maritimes Saturday. High pressure will cross the region
Sunday.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
1045 PM Update: Winds had kicked up a bit w/a little surge this
evening. 00Z UA showed a 25 kt jetlet around 800mbs which was
allowed to mix down to the sfc. High pres ridge will re-
establish itself overnight w/winds dropping off. Clear skies and
the light winds will lead to radiational cooling. Low lying
sites already down in the upper 30s and the continued cooling is
expectd overnight. Could be seeing some upper 20s by daybreak
across the north and west, especially in the low lying areas.
Clouds are trying to work their way back toward the eastern
Maine-New Brunswick border. Latest NAM and RAP show some clouds
working toward eastern Maine by early morning hrs. Daycrew had
this handled well and did not do much adjustment.
Previous Discussion...
A period of quiet weather will continue for the next couple of
days with the ridge of high pressure in place. The biggest
forecast challenge for Wednesday remains temperatures for the
day. This is highly dependent on whether the band of stratus
over New Brunswick makes its way into eastern Maine. Current
thinking is that the stratus will fill back in overnight in the
Downeast region, but then dissipate. This will keep overnight
lows a little warmer for Downeast, but also temper the daytime
heating since they will get a later start. Currently planning to
keep temps above freezing for Downeast, but in the upper 20s
overnight for inland regions, with temps reaching into the 60s
Weds afternoon for inland areas and mid to upper 50s for
Downeast, making Weds most likely the warmest day of the week.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
High pressure will cross the region Wednesday night through early
Thursday, then begin to exit across the Maritimes later Thursday. At
the same time, surface/upper level low pressure will be located
across the Great Lakes while another low begins to develop along the
Mid-Atlantic coast. Generally expect mostly clear skies across the
region Wednesday night through Thursday. The upper low moves east
Thursday night, while the coastal low lifts to southern New England.
Expect increasing clouds across the region Thursday night,
particularly Downeast. The surface/upper lows move to the Gulf of
Maine Friday. Expect mostly cloudy skies along with increasing rain
chances across Downeast areas Friday, with increasing clouds across
northern areas. Expect above normal level temperatures Thursday.
Slightly above normal level temperatures are expected across
northern areas Friday, with slightly below normal level temperatures
Downeast with more extensive cloud cover and developing rain.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
The surface/upper lows cross the Gulf of Maine Friday night through
early Saturday, then exit southeast of Nova Scotia later Saturday.
At the same time, high pressure will remain ridged north of Maine.
Uncertainty still exists regarding the track of the surface/upper
lows. The greater precipitation chances will occur Downeast,
with lesser precipitation chances northward across the remainder
of the forecast area. A more northerly low track would increase
precipitation amounts across Downeast areas, with increased
precipitation chances across northern areas. A more southerly
low track would diminish precipitation amounts Downeast and
limit precipitation chances across northern areas. Based on
critical thicknesses, the vicinity of the cold pool aloft with
the upper low and favorable overnight diurnal timing, expect
precipitation will mix with and change to snow across the region
Friday night which should persist early Saturday. Accumulating
snow is expected across much of the region Friday night through
early Saturday. However, amounts will be dependent on how
rapidly the transition to snow occurs and the eventual tracks of
the surface/upper lows. Precipitation will then taper to rain
showers Saturday. A series of difficult to time upper level
disturbances and surface trofs are possible Sunday through
Tuesday. Generally expect partly/mostly cloudy skies Sunday
through Tuesday. Have kept shower chances at slight chance
levels due to the uncertainty with timing. Expect near normal
level temperatures Saturday. Above normal level temperatures are
expected Sunday through Tuesday.
&&
.AVIATION /03Z WEDNESDAY THROUGH SUNDAY/...
NEAR TERM: VFR expected through Weds. Some chance of MVFR in
cigs late tonight/Weds morning for CAR/PQI/HUL. Gusty winds
less than 25kts expected to calm overnight.
SHORT TERM:
Wednesday night through Thursday night...Generally VFR, though MVFR
possible later Thursday night. Light winds Wednesday night.
East/southeast wind 10 to 15 knots Thursday, then east/northeast 10
to 15 knots Thursday night.
Friday...VFR/MVFR. Rain late mostly Downeast. East/northeast
wind 10 to 20 knots with gusts up to 25 knots.
Friday night...MVFR/IFR, occasional LIFR. Rain mixing with and
changing to snow. North/northeast wind 10 to 20 knots with gusts up
to 25 knots.
Saturday...MVFR/IFR, occasional LIFR, early. VFR/MVFR late. Snow
tapering to rain showers. North/northeast wind 10 to 20 knots with
gusts up to 25 knots.
Saturday night through Sunday...VFR/MVFR. North/northeast wind
around 10 knots Saturday night. Light winds Sunday.
&&
.MARINE...
NEAR TERM: SCA conditions will continue in the outer coastal
waters overnight. Winds will drop below 25kt from S to N by the
early morning hours, but seas will remain above 4 ft through
tomorrow morning.
SHORT TERM: Conditions below small craft advisory levels
Wednesday night/Thursday. Small craft advisory conditions
expected Thursday night. Gale force wind gusts possible Friday
into early Friday night. Visibilities lowering in rain Friday.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...None.
MARINE...Small Craft Advisory until 8 AM EDT Wednesday for ANZ050-051.
&&
$$
Near Term...Hewitt
Area Forecast Discussion
National Weather Service Quad Cities IA IL
832 PM CDT Tue Apr 13 2021
.UPDATE...
Issued at 830 PM CDT Tue Apr 13 2021
Have expanded the Frost Advisory to include the I-80 corridor.
Latest satellite trends show the stratus into northern Iowa moving
more latitudinal than longitudinal, and would support some of the
recent guidance in keeping the I-80 corridor, which has some
susceptible vegetation, largely absent of this thermally
impactful cloudiness. Some cirrus will be present, but satellite
shows this to be rather thin and should be limited in impacts to
temperatures. With 850 mb temperatures progged back down to around
-5C to -6C tomorrow morning, anticipate lows near to a bit below
those from this morning in most areas and around 30-36F. Far
northern sections, especially in eastern Iowa, lows are a bit
tricky as the stratus may eventually work southward and offer
periodic bouts of cloudiness. Thus, it looks like there is the
potential to be a bit warmer than forecast into portions of
northeast Iowa.
&&
.SYNOPSIS...
Issued at 244 PM CDT Tue Apr 13 2021
Another great day was unfolding across all of eastern Iowa,
northwest Illinois and far northeast Missouri, with the area under
influence from high pressure ridging extending from the central
Great Plains into the Ohio River Valley. Skies featured a mix of sun
and clouds, with somewhat cool temperatures atypical for mid-April.
Values as of 2 PM ranged from 47 in Dubuque, to 57 in Keokuk.
&&
.SHORT TERM...(This Evening through Wednesday)
ISSUED AT 244 PM CDT Tue Apr 13 2021
Key Messages:
1) Patchy to areas of frost tonight, with impacts likely mainly
south of I-80.
2) A chance for PM sprinkles Wednesday, but most will remain dry.
Cool temperatures continue.
High pressure will remain in control of our weather for through
Wednesday, meaning quiet weather with mainly dry condtions are
expected. The only exception will areas of eastern Iowa and
northwest Illinois mainly north of I-80 Wednesday afternoon, where
there will be a chance of sprinkles. Several CAMs including the
NAMnest and HRRR are on board with this idea as an area of CVA
rotates around the southern portion of a 500 hPa low centered over
the Great Lakes. These will be scattered in nature, with much of
likely remaining dry through the day.
The more pressing concern will be the threat of frost tonight, which
looks likely with light winds, clear skies and a cool air mass in
place across parts of the area. After coordinating with
surrounding offices, went ahead and issued a frost advisory for
counties along and south of Hwy 34 in southeast Iowa, west central
Illinois and far northeast Missouri. This area is most
susceptible across the CWA with regards to vegetation.
Temperatures are expected to fall into the low to mid 30s here.
Elsewhere, temperatures will be cold with values dropping to near 30
along the Hwy 20 corridor. With no susceptible vegetation here
did not go ahead with frost/freeze headlines. Highs tomorrow will
continue to be cool with values in the upper 40s/low 50s.
.LONG TERM...(Wednesday Night through Tuesday)
ISSUED AT 244 PM CDT Tue Apr 13 2021
Key Messages:
1) Below normal temperatures continue.
2) Mainly dry through the weekend; precipitation chances increase
next week.
3) Potential for frost again Wednesday Night/Thursday Morning.
Wednesday night and Thursday morning will once again be monitored
for frost/freeze potential as another night of cold temperatures is
expected. While temperatures are forecast to not be as cold as
tonight, values in the low 30s will be more widespread. Will monitor
for potential for more headlines tomorrow.
Otherwise, most of the long term period will feature mainly dry
conditions and continued cool temperatures with the dominant flow
pattern expected to remain out of the northwest. Daily highs in the
50s to near 60 are expected, with overnight lows in the 30s to low
40s.
Chances for precipitation are mainly favored Friday night and
Saturday as a weak shortwave passes across the area to the south.
Models are in disagreement of intensity, with the GFS suggesting
more of a moisture draw, stronger lift and thus a higher QPF for our
southeast Iowa, west central Illinois and northeast Missouri
counties. However, this looks to be the outlier of guidance, so will
play more on the conservative end with just a slight chance to
chance of POPs. This is favored over our southeast Iowa, west
central Illinois and northeast Missouri counties.
There is agreement that a cold front approaching the area will be
the driver for our next chance of precipitation, which looks to be
favored next Monday/Monday night. NBM has introduced slight
chance POPs with this run, and I think that`s a good starting
point considering we have plenty of time for things to get more
refined in the guidance.
&&
.AVIATION...(For the 00Z TAFS through 00Z Wednesday Evening)
ISSUED AT 547 PM CDT Tue Apr 13 2021
Predominantly VFR conditions expected during the period. Stratus
will continue decreasing with sunset leading to mainly clear skies
tonight, with gusty WNW winds diminishing to below 10 kts. On
Wednesday, stratus will redevelop with surface heating in the
presence of cyclonic flow/cold advection. CIGs may initially
range from lower VFR to some MVFR, but with mixing should evolve
into solidly VFR. WNW winds also look to increase on Wednesday at
or above 10 kts and gust up to 20 kts at times by late morning
through the afternoon.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...Frost Advisory from 1 AM to 8 AM CDT Wednesday for Cedar-Des
Moines-Henry IA-Iowa-Jefferson-Johnson-Keokuk-Lee-Louisa-
Muscatine-Scott-Van Buren-Washington.
IL...Frost Advisory from 1 AM to 8 AM CDT Wednesday for Bureau-
Hancock-Henderson-Henry IL-McDonough-Mercer-Putnam-Rock
Island-Warren.
MO...Frost Advisory from 1 AM to 8 AM CDT Wednesday for Clark-
Scotland.
&&
$$
UPDATE...McClure
SYNOPSIS...Speck
SHORT TERM...Speck
LONG TERM...Speck
AVIATION...McClure
AREA FORECAST DISCUSSION...UPDATED
National Weather Service Jackson KY
1141 PM EDT Tue Apr 13 2021
.UPDATE...
Issued at 1141 PM EDT TUE APR 13 2021
Skies have partially cleared across portions of the Cumberland
Valley, with scattered to broken mid-level clouds hanging on
across the rest of the area. A few sprinkles are still showing up
on radar across southern Kentucky. The latest higher resolution
model guidance suggests little in the way of shower activity
until closer towards dawn near the I-64 corridor; however, much of
the guidance does not have the current activity captured that
well. Have therefore kept in a few sprinkles through the night,
with an uptick in PoPs and more in the way of isolated shower
activity towards the Bluegrass closer to daybreak. Current
temperatures range from the lower to middle 50s in the cooler
spots, to around 60 on ridges. Made a few adjustments to the lows,
mainly to allow up to a several degree split, given the cloud
breaks from time to time. Updates have been sent.
UPDATE Issued at 824 PM EDT TUE APR 13 2021
A few showers have popped up south of the Hal Rogers Parkway,
where some modest isentropic lift is occurring, according to the
latest RAP data. This forcing should subside in the next hour or
so. Accordingly, have included some slight chances for our south
early this evening. The rest of the forecast remains on track,
and have mainly freshened up the hourly temperatures through this
evening. Updates have been sent.
&&
.SHORT TERM...(This evening through Wednesday night)
Issued at 517 PM EDT TUE APR 13 2021
Short term challenges center around a couple of minor shortwave
impulses moving through a zonal flow pattern aloft. At the surface
there are a couple of surface troughs spinning around the southern
side of low pressure centered over Lake Superior. There is also a
stationary frontal zone to our south across the Tennessee Valley.
Models have not been consistent with sensible weather, and in
particular PoPs. Light showers are expected to develop late
tonight as the first of the two troughs out to our northwest
drops southeast into the Commonwealth. Wind profiles (H850 winds)
do not provide much support for shower activity until closer to
dawn Wednesday. With inconsistencies seen in previous runs,
decided to stick closer to low chance PoP across the north closer
to the boundary, and only slight chance PoPs across the south.
Ramped PoPs up for Wednesday as the surface wave of low pressure
tracking through Tennessee and Southern Appalachia interacts with
the surface boundary dropping southeast across eastern Kentucky.
This second feature, or wave of low pressure will provide the best
opportunity for rain to the area. With the exception of NBM,
there is little if any chance for any thunder based on guidance.
The NBM brings a slight chance of thunder across the south. With
all the uncertainties and relatively lower confidence in model
guidance, decided to stick with previous forecasts, leaving any
mention of thunder out of the forecast. However, will mention this
to upcoming shifts for a closer look. Temperatures will run just
below normal for this time of year with afternoon highs Tuesday in
the lower 60s and overnight lows dipping to around 50 tonight and
to around 40 tomorrow night. Can not totally rule out a little
patchy frost in our western valleys late Wednesday night into
early Thursday as temperatures drop into the mid 30s.
.LONG TERM...(Thursday through Tuesday)
Issued at 332 PM EDT TUE APR 13 2021
Eastern Kentucky begins the period sandwiched between a deep low
across the Great Lakes and embedded short waves across the Southern
Tennessee Valley and deep south. A cold front will be departing
eastward as a surface high meanders east across the Central Plains
and into Western Kentucky. Flow will then shift out of the
west/northwest. This should allow for continued clearing Thursday
afternoon and evening. Frost development continues to look best
Thursday night into Friday morning as there will be clearer skies
and calmer winds, and therefore, better ridge/valley splits. This,
again, will depend on how much sky clearing is seen into Thursday
night. By Friday, high pressure will be positioned along the Mid-
Atlantic, allowing for an uptick in highs when compared to Thursday,
but still remaining below average.
Through the weekend and early next week, embedded shortwaves will
bring unsettled activity. These features do promote the opportunity
for moisture, but it remains limited across the CWA. There is also
quite a bit of uncertainty in regards to timing and QPF, with the
GFS being the most aggressive. Long term guidance suggests an
area of low pressure developing and evolving eastward from
southern Canada late in the period, but for now, have stayed with
the blend given the large uncertainties. Overall, temperatures
remain below normal through the period with highs ranging from the
low to mid 60s and lows in the low to mid 40s.
&&
.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
ISSUED AT 824 PM EDT TUE APR 13 2021
Clouds will gradually thicken and lower tonight, with a few
showers threatening, mainly after 06z. Better rain chances will
move in during the day on Wednesday, as area of low pressure
tracks across the southern Appalachians. Ceilings will dip down to
the MVFR/IFR as the more sustained activity occurs into Wednesday
afternoon. Improvement back to VFR will move in across the I-64
corridor, including KSYM late in the period. Winds will be light
and variable tonight, before increasing to 5 to 8 kts, generally
out of the north northwest Wednesday morning. Winds will then
lighten up once again later in the day.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GEOGERIAN
SHORT TERM...RAY
LONG TERM...BB
AVIATION...GEOGERIAN
Area Forecast Discussion
National Weather Service Nashville TN
815 PM CDT Tue Apr 13 2021
.UPDATE...
FOR EVENING DISCUSSION.
&&
.DISCUSSION...
Radar this evening shows widely scattered showers across the
southeast two-thirds of the cwa. This activity is occurring in a
WAA regime above a weak cold front stalled across our southeast
counties. These evening showers should continue moving eastward
out of the area over the next couple hours, and have added a
slight chance pop for the evening in line with the HRRR and
CONSShort models. Little activity is expected most of the night,
but additional showers will spread into our northwest counties
toward sunrise with pops increasing from northwest to southeast.
Made some minor adjustments to pops and sky cover for the
overnight hours but nothing major.
Although current temperatures across the area are in the mid to
upper 60s, CAA behind the front will drop temperatures down into
the low to mid 50s overnight. Highs tomorrow will be several
degrees cooler over our northwest versus our southeast due to the
stalled frontal boundary. Light rain will spread across the
entire area during the day but most precip will be out of here by
evening, with total rainfall amounts ranging from a tenth up to a
third of an inch.
&&
.AVIATION...
00Z TAF DISCUSSION.
Despite some VCSH at CSV, all terminals are currently at VFR. Cigs
and vis will begin to decrease tomorrow morning with some heavier
showers moving through the area. Expecting MVFR to IFR conditions
beginning with CKV around 15Z and remaining terminals between 17Z
and 18Z. Northerly winds remain through the TAF period.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
DISCUSSION......Shamburger
AVIATION........Adcock
Area Forecast Discussion
National Weather Service Springfield MO
640 PM CDT Tue Apr 13 2021
.SHORT TERM...(This evening through Wednesday)
Issued at 108 PM CDT Tue Apr 13 2021
Cloud cover continues to gradually break up this afternoon as the
disturbance that produced rain last night and early this morning
exits the region to the east. A weak surface front was located
over southern Arkansas with cooler north winds over the region
holding temperatures down in the upper 60s to lower 60s.
We`re just starting to see some increasing cloud cover over southwest
OK and the TX Panhandle as another upper level disturbance moves
over the central and southern Plains. The disturbance will
interact with lower level convergence along an elevated front at
around 850 mb which lines up just south but parallel to I-44 to
produce mainly scattered showers this evening and overnight over
southern MO and southeast Kansas. The HRRR is forecasting the
heaviest rainfall to occur from 2 AM to 6 AM. Not seeing much
instability on Bufkit forecast soundings but some steeper mid-
level lapse rates may be adequate to get a few storms, mainly
south of Highway 60.
Most of the showers are expected to be east of the forecast area
by late morning to early afternoon Wednesday with afternoon
temperatures similar to today, topping out in the 60s.
.LONG TERM...(Wednesday Night through Tuesday)
Issued at 306 PM CDT Tue Apr 13 2021
There is still potential for frost early Thursday morning over
central Missouri and higher elevations on the Ozark Plateau, where
little to no cloud cover is expected. Further south, there may be
enough cloud cover with another disturbance moving from the
southern Plains into Arkansas.
The National Blend of Models temperature output shows very little
spread in temperature forecast for the next 4-5 days so confidence
remains high for below normal temperatures through the forecast
period.
Another chance for rain still looks likely for Friday and Saturday
as a surface low deepening over west Texas draws Gulf Moisture
northward into the our region. While the main surface front
remains south of the area, decent lift with the upper low should
generate a fairly widespread 0.5 inch to inch of rain over the
region. Not seeing too much in the way of instability over our
area, so thunderstorms have been kept out of the forecast for now.
High pressure builds in behind the passing upper low and drops
temperatures even more for the weekend with highs only expected to
rise into the 50s.
Thereafter expect mainly dry conditions early next week with only
a slight warmup into the 60s by Monday. Could see an additional
cool down in the middle of next week with a cold front passage
Tuesday or Wednesday.
&&
.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 625 PM CDT Tue Apr 13 2021
Middle to high cloud cover will increase through this evening as
showers spread into the Ozarks from Oklahoma. Ceilings will lower
but remain VFR for the Joplin and Springfield aerodromes but
Branson can expect MVFR ceilings. Branson will be more impacted as
the it will be closer to the main area of rain. Flight conditions
will begin to improve by midday Wednesday as the rain shifts east
of the region.
&&
.SGF WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&
$$
SHORT TERM...Terry
LONG TERM...Terry
AVIATION...Hatch
Area Forecast Discussion
National Weather Service Shreveport LA
909 PM CDT Tue Apr 13 2021
.UPDATE...
Updated forecast was minor this evening, pertaining to the
returning warm front across our region and its effects on pops for
the remainder of the night.
Chasing a leftward moving supercell along a retreating warm front
this evening across portions of NE TX with several reports of
severe hail along its path before it finally dissipated across
Eastern Harrison County and Southwest Caddo Parish. We are still
dealing with some widely scattered convection across portions of
NE TX located along an instability axis which extends from SE TX
into extreme NW LA and SW AR. Latest HRRR and 00z NAM output
suggests that our western third will continue to see the
possibility of renewed convection in association with this
instability axis and the northwestward moving warm front before
broad scale lift increases dramatically late tonight and
therefore storm coverage does as well areawide.
Perturbation in developing southwest flow aloft coming out of the
TX Hill Country and a developing 30-40kt low level jet will
generate the necessary upward and isentropic forcing for the
development of scattered to numerous showers and thunderstorms
late tonight through the first half of Wednesday. While the
instability axis should weaken overnight, mid level lapse rates
are sufficient enough for at least some large hail overnight,
mainly across our southwest half, depicted best by SPC`s
maintaining a Slight Risk across our region.
Only change was to reorganize pops for the remainder of the
evening more towards the west with likely pops areawide as we
approach sunrise Wed Morning.
Update will be out shortly...13.
&&
.PREV DISCUSSION... /issued 523 PM CDT Tue Apr 13 2021/
AVIATION...
A nearly stationary frontal boundary across our airspace and a
very unstable environment near a LFK, to SHV to ELD line will
result in the development of widely scattered thunderstorms this
evening that should begin shifting and/or developing to the north
and west as the boundary lifts north and west through the evening
hours. Forcing will be subtle but enough from the west to help
initiate more in the way of scattered to numerous showers and
thunderstorms after midnight and especially during the morning
hours on Wednesday across much of our airspace. Winds will remain
mostly from the E or NE with speeds under 10kts through the night
except for convectively induced winds which could be much
stronger. Look for ceilings to gradually become MVFR overnight and
eventually, IFR with prevailing TSRA through much of the morning
hours on Wed before the precipitation exits the region to the east
during the afternoon hours on Wed.
While the convection should end during the afternoon, look for
post frontal ceilings to remain mostly IFR with MVFR VSBYS in the
wake of the convection to prevail through the afternoon hours as
well.
13
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 60 69 53 71 / 70 60 60 20
MLU 61 68 51 70 / 70 80 50 20
DEQ 54 67 49 70 / 70 50 30 10
TXK 57 64 50 69 / 70 50 40 10
ELD 54 64 48 70 / 70 60 40 10
TYR 62 69 52 70 / 70 40 60 20
GGG 60 69 52 70 / 70 50 60 20
LFK 66 73 55 72 / 70 50 70 30
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...None.
LA...None.
OK...None.
TX...None.
&&
$$
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