Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 06/16/20
Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
104 PM AKDT Mon Jun 15 2020
Upper level easterly flow will continue to dominate the weather
pattern for the next couple of day, although the Interior ridge
has now weakened and moved back northeast into the Yukon. This
will mean slightly cooler conditions, less instability for strong
thunderstorms, and more clouds moving into the Interior,
especially by Tuesday as the remnants of a continental easterly
wave moves into the region. Expect cloudier and slightly cooler
temperatures over the southern Interior tomorrow, however there
will still be enough day time heating to produce isolated
thunderstorms over much of the interior.
Upper Levels and Analysis...
The Interior ridge aloft is continues to weaken and lift to the
north with the center just north of the Brooks Range. A series of
easterly waves the past few days are responsible for this
weakening. A shortwave pushing west over the Central Interior
this evening will be the focus to thunderstorms especially along
a Ambler to Bettles to Fairbanks to Northway line. Another and
much stronger shortwave will push into Eastern Interior Tuesday
morning and into Central Interior Tuesday afternoon. Mid- level
temperatures at around 5000 feet remain in the 7-10 C range, thus
overall surface temps still remain slightly above average for most
of the Interior.
The 15/12z models suite continues to struggle with fast paced
easterly wave pattern on both the timing and strength of features.
The GFS continues to indicate a cooler and wetter day tomorrow
as compared to a drier, warmer ECMWF model that shears apart the
easterly wave with thunderstorms in the afternoon along a Bettles
to Fairbanks to Northway line. Both the NAM and HRRR indicate
abundant deep layer moisture over the Eastern Interior Tuesday
morning will move northwest into the Central Interior during the
day. Timing of the shortwave will play a role in precip type,
either widespread stratiform or more showery precipitation. Given
axis of instability and arrival time of moisture opted for a
cooler wetter morning followed by showery and Isolated thunder
storms scenario along the Bettles to Fairbanks to Northway line.
Expect wetting rains in the Eastern Interior south of the Yukon
River Tuesday morning with a transition to showers in the
afternoon. Expect more sunshine and heating and along with
increased instability west of Fairbanks in the Central Interior
and westward over the Western interior to produce mostly showery
precipitation with isolated thunderstorms in the afternoon.
West Coast and Western Interior...
Isolated thunderstorms that develop this afternoon will continue
will into this evening, favoring the Interior and Baird Mountains
as well as interior Norton Sound. Otherwise, sea breezes will
keep coastal locations cooler and mostly dry. Tuesday and
Wednesday will see increasing thunderstorm threats for the
Interior as instability axis moves over the region, and a series
of weak disturbances aloft help spark storms off during the
afternoon and evenings.
North Slope and Brooks Range...
Daily afternoon and evening thunderstorms will be possible all
along the Brooks Range into the middle of the week. High pressure
over the Arctic will keep an onshore northeast wind in place,
which will gradually strengthen so daily high temps will gradually
cool back to more normal values. Tuesday night and Wednesday, some
showers may push off the Brooks Range and clip the Eastern North
Slope, but there remains much discrepancy with the track of a wave
disturbance moving north from the Yukon, so for now this forecast
package will stay on the drier side.
Central and Eastern Interior...
Thunderstorms continue to fire up along the instability axis from
near Bettles to Fairbanks, to Northway. These isolated
thunderstorms will continue well into this evening. There is
enough instability that some of these storms may produce frequent
lightning, small hail, and heavy downpours. These storms should
push all the way up into the western Yukon Flats and southern
Tricky forecast for Tuesday as yet another easterly wave moves
into the area. There remains rather significant discrepancies
between the models with how far west and how fast the easterly
wave moves into the Central Interior. A quicker solution would
likely keep the Central Interior in clouds and light rain and
keep temperatures in the 60s while a slower solution would likely
produce mostly sunny conditions with afternoon thunderstorms and
temps into the mid 70s. Opted to keep a middle ground approach
with a cloudy and cool start to the day but a transition to
afternoon isolated thunderstorms and temps likely closer to the
low 70s for the areas along the Bettles to Fairbanks to Northway
line of instability. Expect cooler and wetter conditions over much
of the Eastern Interior for most of the morning and a transition
to showers in the afternoon. Expect increasing clouds in the
morning and early afternoon with isolated thunderstorms developing
in the afternoon to the west of Fairbanks in the Central interior.
Coastal Hazard Potential Days 3 and 4...None.
Mainly VFR conditions expected over the interior and West Coast
terminals this afternoon and tonight however Isolated thunderstorms
are possible at all interior terminals with VCTS retained in all
interior TAFS through this evening. Expect brief gusty winds from
thunderstorm outflow boundaries and periods of MVFR conditions
with periods of rain showers as the thunderstorms diminish late
this evening. Patchy fog will return to the Arctic Coast at some
point overnight. Expect LIFR conditions to develop tonight at the
North Slope terminals as stratus and fog develop over open icepack
leads and push inland with onshore flow.
Winds in the 10 to 20 knot range and seas less than 4 ft are
expected in ice free waters through Friday.
Isolated thunderstorms will continue to be a threat this evening
over much of the Interior with the greatest axis of instability
along a line from near Ambler to Bettles to Fairbanks to near
Northway. Given moderate instability and some forcing aloft, some
storms will likely be strong with potential for isolated storms
to produce frequent lightning. Temperatures in the 70s are
expected over much of the interior with upper 70 to near 80
degrees in the yukon flats again tomorrow. Minimum relative
humidity levels will generally drop into the 30s and 40s percent
over most of the interior. Lowest values in the 20s percent will
again be found in the Yukon Flats this evening and tomorrow
afternoon and evening.
The instability axis shifts west into the Western Interior
Tuesday as an easterly wave brings in extensive cloud cover and
wetting rains to the Eastern and Central Interior south of the
Yukon River. There will still be isolated thunderstorm threats,
but the best chances will be farther west. Min Rh values will
gradually rise as the Interior ridge breaks down and temps slowly
fall and clouds/moisture increase.
No major concerns.
CCC JUN 20
Area Forecast Discussion
National Weather Service Charleston SC
1012 PM EDT Mon Jun 15 2020
Surface low pressure meandering off the Southeast coast early
this week should gradually advance north along the East Coast
around mid week. Also, an upper level low pressure will settle
over the Southeast this week and should gradually weaken
through the weekend.
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
As of 1010 PM: KCLX indicated that the forecast area was free of
convection. The latest run of the HRRR times a round of showers
over the inland SC counties by 5Z. I will update the forecast to
reduce PoPs through midnight, then indicate isolated to
scattered showers over the northern half of the forecast area
late tonight. Based on temperatures observed in the lower to mid
60s, I will lower the low temperature forecast into the low 60s.
As of 620 PM: Recent observations indicated that temperatures
across the CHS Tri-County have cooled into the mid-60s,
primarily north of I-26. Temperature are on pace to fall into
the low 60s by midnight. I will update the forecast to cool
evening hourly temperatures. KCLX has detected rounds of mist or
sprinkles across the Tri-county over the past hour or two. I
will keep 20-30 PoPs for showers. Elsewhere, minor changes were
made to cool temperatures this evening.
This Evening and Tonight: Sfc low pressure centered off the Southeast
Coast will continue to shift south offshore while a mid/upper
lvl low becomes cutoff and centered across South Carolina overnight.
Dry mid-lvl air wrapping around the southern edge of the cutoff
low along with a north sfc wind behind the sfc low south of the
area will likely continue to limit overall shower activity, but
few to scattered showers remain in the forecast as low-lvl
moisture resides across the area. The bulk of precip activity
should occur near the Southeast South Carolina coast this evening
and overnight, but showers should eventually occur inland due
to some enhanced lifting from the cutoff low aloft. Low-lvl
moisture at the very least should produce an abundance of low
clouds that shift south across the region through the overnight
period. Overnight lows will be cooler, but clouds will help
limit the overall cooling late. In general, low temps will range
in the low/mid 60s, coolest inland.
.SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/...
Tuesday through Thursday: This period will feature a continuation of
below-normal temperatures and a daily, variable chance for
As of Monday afternoon, NHC assigned to low pressure off the
Southeast coast a 10 percent probability for tropical development
through 5 days. In general, latest guidance generally agrees that as
an upper low settles over the Southeast, this surface low should
eventually turn toward the north/northeast and remain off our
coastline. Thus, the latest forecast assumes no significant
development near/associated impacts along our coastline.
Thus, an unseasonably deep, cut-off upper low is expected to settle
over the Southeast and should remain the primary factor driving our
weather through Thursday. Of particular interest, models generally
agree that forcing for ascent/associated enhanced moisture will
reside on the northern semi-circle of the core of this upper low,
and significantly drier air will wrap around the southern periphery
of this gyre. The exact position/orientation of the upper low will
govern the location/magnitude of the moisture gradient, and this in
turn will determine precipitation coverage. With minor day to day
variation, in general maximum PoPs range from chance north/interior
counties to slight chance far south during the afternoon/evening
hours. Isolated/scattered showers could persist across northern/
northern/interior counties Tuesday night and across northern/coastal
counties Wednesday night. While convection will be mainly driven by
low-level diurnal warming beneath a persistent cold pool aloft, by
Thursday the sea breeze could also begin to play a role in convection
Instability remains quite unimpressive, especially Tuesday and
Wednesday. However, unseasonably cold mid level temperatures,
perhaps as cold as -14C to -15C Tuesday, justifies at least a
slight chance for thunderstorms. Limited instability should
translate to a low chance for any severe weather Tuesday and
Wednesday, but the mid level cold pool could support an isolated
thunderstorm with hail, particularly Tuesday PM. As the upper low
gradually lifts NE, fills and weakens, warmer temps/somewhat
improved instability should support a better chance for
diurnal thunderstorms Thursday afternoon/evening.
Otherwise, expect unseasonably cool temperatures with highs in the
middle 70s to lower 80s Tuesday, lower 80s Wednesday and middle 80s
Thursday. temperatures should bottom out in the lower to middle 60s
Tuesday night and middle to upper 60s Wednesday night.
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
A mid-level low will be to our northeast Thursday night. It`s
forecasted to weaken and move over the Northeastern U.S. Friday,
becoming absorbed into weak troughing along the East Coast Saturday
and Sunday. The shower/thunderstorm coverage should decrease each
day. Temperatures will trend higher into the weekend.
.AVIATION /02Z TUESDAY THROUGH SATURDAY/...
KCHS MVFR ceilings are expected to lower to IFR around midnight.
MOS and forecast soundings indicate that cloud bases will lower
through the night, but remaining within IFR range. With daytime
heating, ceilings will lift through Tuesday, rising back to
MVFR early Tuesday afternoon. Winds will remain from the north
around 10-12 kts,
KSAV, prior to the 0Z TAF, IR satellite and observations
indicated that MVFR were approaching the KSAV from the north,
expected to arrive by 1Z. MVFR ceilings are expected to continue
at KSAV until late Tuesday morning, improving to VFR. Gusty
north winds are expected to redevelop late Tuesday morning.
Extended Aviation Outlook: Flight restrictions should remain limited
to brief impacts from showers/thunderstorms, especially each
afternoon/evening, into this weekend.
As of 620 PM: Recent observations indicated that gusts across
the near shore waters were gusting between 25-28 kts. Based on
oncoming CAA and wind on high resolution guidance, I will expand
Small Craft Advisories for all marine zones outside the CHS
Harbor until 2 AM.
This Evening and Tonight: A fairly pinched
pressure gradient continues along the coastal waters as a sfc
low shifts south of the area and remains centered offshore.
North/northeast winds between 15- 20 kt will be common along
with a few wind gusts up to 25 kts at times, especially across
offshore Georgia waters. Northerly winds have also built seas up
to 4-6 ft across offshore Georgia waters, where a Small Craft
Advisory is in effect until 11 PM tonight. Latest guidance
suggests weak cold air advection arriving aloft tonight, which
could result in a surge of northerly winds, especially across
northern South Carolina waters. Confidence remains too low that
Small Craft Advisory level conditions will prevail for longer
than an 1-2 hour period, but one could eventually be needed.
Otherwise, north-northeast winds between 15-20 kt will prevail
through the overnight period while seas generally range between
Tuesday through Friday: Tuesday, expect elevated north winds as high
as 15-20 knots and seas 3-5 feet. Thereafter, the pressure gradient
should weaken, and W/NW winds backing to SW should average 15 kt or
less Tuesday night and Wednesday. Thursday through Friday, expect a
more typical regime featuring a daily sea breeze and modest nocturnal
surging of S/SW winds at night. Seas should subside to 2-3 feet
Tuesday night and should remain in this range through late
MARINE...Small Craft Advisory until 2 AM EDT Tuesday for AMZ350-352-354-
Area Forecast Discussion
National Weather Service El Paso TX/Santa Teresa NM
537 PM MDT Mon Jun 15 2020
.AVIATION...00Z TAF CYCLE...
Scattered RA/TS continue to develop and slowly drift
N/NE across parts of the area, mainly favoring the higher
terrain. VCTS/TSRA around TCS and DMN will persist thru roughly
03Z, so kept a TEMPO group for VRB strong gusts, reduced vis of
3SM, and -TSRA for that time period. Confidence is lower for
storms near LRU, warranting a VCTS for a few hours. Kept any
mention of storms out of ELP for now. Erratic outflow wind gusts
will be possible at all terminals this evening. All activity looks
to end by 04-06Z, leaving FEW120 SCT-BKN250 skies and
southeasterly prevailing winds overnight.
.PREV DISCUSSION...243 PM MDT Mon Jun 15 2020...
Showers and thunderstorms will be possible once again this
afternoon/evening, focusing the best chances for rain over area
mountains and areas west of the Rio Grande River. We`ll see a
similar set up on Tuesday, but rain chances may be able to extend
into Las Cruces/El Paso. On Wednesday, westerly winds begin to dry
the region out, however rain chances may linger over eastern El
Paso and all of Hudspeth County. Thursday begins a warming trend,
with temperatures gradually increasing each day. By Saturday, we
may see lowland high temperatures reaching back into the century
.SHORT TERM...Tonight and Tuesday...
Showers and a few thunderstorms linger early tonight with areas of
breezy outflow winds. Most, if not all, activity diminishes after
06Z, with low temperatures dropping into the 60s most locations
(near 70 in El Paso).
Indications are moisture reluctantly slides east on Tuesday as winds
out across western regions shift west/southwest. Axis of moisture
may reside over the central portions of the area by the afternoon
hours, although global models are not all that enthused with this
prospect and shift plume farther east. At this time, extended HRRR
is seemingly the most bullish model giving the central regions
(including ELP and LRU) isolated to scattered showers and storms, so
have 10 POPs across this region. Additionally, the NAM suggests a
similar thermodynamic environment to the HRRR, so feel like this
threat is at least somewhat realistic. All you would need is an
outflow at that point for a chaotic situation. So, once again,
temperatures in the mid 90s on Tuesday with isolated showers and
storms favoring the higher terrain and vicinity, along propagating
outflow, and perhaps portions of lowland locations.
.LONG TERM...Tuesday night through Monday...
Global models and extended CAMs drop off any lingering convection
by midnight Tuesday, with skies beginning to clear from west to
east by Wednesday morning as dry, westerly winds take over. This
will shove moisture to our eastern zones. How far west the
moisture makes it on Wednesday is still in question. The ECMWF
pushes the moisture and dryline convergence east of the
Borderland, keeping the region dry on Wednesday. The GFS (and
ensembles) and the NAM keeps PW values of 1.00"+ and respective
dryline in Eastern El Paso and Hudspeth counties Wednesday
evening. For now, have kept the given low-end NBM pops in this
region due to the uncertainty.
Starting Thursday, upper level ridging and dry, westerly winds
will completely push the moisture tap east of us. Temperatures
will rise gradually each day through the weekend under the ridge.
By Saturday, the lowlands may be back to reaching 100F(+) high
Another day of showers and thunderstorms by the afternoon hours is
expected on Tuesday focusing on the higher terrain with perhaps some
lowland storms as well. Dry lightning and gusty outflow winds the
main concerns with the strongest storms. Mainly dry conditions
develop Wednesday through the weekend as westerly winds shove
moisture to the east. Ventilation will remain mainly excellent
through the period as breezy west/southwest winds and relatively
high mixing heights coincide. With said deep mixing heights comes an
increase in MAX Haines index values, becoming 4/5 Wednesday and 5/6
.PRELIMINARY POINT TEMPS/POPS...
El Paso 70 96 73 96 / 10 10 10 0
Sierra Blanca 60 90 65 91 / 0 10 10 20
Las Cruces 65 94 67 95 / 20 10 0 0
Alamogordo 65 94 67 97 / 20 10 0 0
Cloudcroft 47 70 52 73 / 20 20 10 10
Truth or Consequences 66 93 67 95 / 20 20 0 0
Silver City 61 85 62 87 / 30 20 0 0
Deming 63 95 64 95 / 20 10 0 0
Lordsburg 63 93 64 94 / 20 10 10 0
West El Paso Metro 72 97 74 97 / 10 10 10 0
Dell City 62 95 65 98 / 0 10 0 10
Fort Hancock 66 97 69 98 / 0 10 10 20
Loma Linda 65 89 69 91 / 10 10 20 0
Fabens 69 96 72 98 / 10 10 10 0
Santa Teresa 66 94 69 95 / 10 10 10 0
White Sands HQ 69 93 73 95 / 20 10 0 0
Jornada Range 64 93 66 95 / 20 10 0 0
Hatch 64 94 66 96 / 20 10 0 0
Columbus 67 95 69 96 / 20 10 10 0
Orogrande 66 93 68 95 / 20 10 10 0
Mayhill 51 81 55 85 / 20 20 10 20
Mescalero 50 81 55 84 / 20 20 10 10
Timberon 49 79 52 82 / 20 10 10 10
Winston 51 85 53 87 / 30 20 0 0
Hillsboro 59 92 62 94 / 20 20 0 0
Spaceport 61 92 63 95 / 20 10 0 0
Lake Roberts 54 86 56 87 / 30 20 0 0
Hurley 59 88 59 90 / 20 20 0 0
Cliff 54 93 54 93 / 20 10 0 0
Mule Creek 61 89 61 90 / 20 10 0 0
Faywood 60 89 62 91 / 20 20 0 0
Animas 62 94 62 95 / 20 10 10 0
Hachita 61 93 62 94 / 20 20 20 0
Antelope Wells 62 93 63 94 / 30 20 10 0
Cloverdale 61 88 62 89 / 30 10 20 0
Area Forecast Discussion
National Weather Service Grand Forks ND
1012 PM CDT Mon Jun 15 2020
Issued at 1008 PM CDT Mon Jun 15 2020
Have trimmed up pops even more keeping just the far northern
portion of NW MN with an isolated chance of thunder. One cell did
develop over the NW Roseau county in the past hour. It has
weakened and moved north of the border as quickly as it developed.
Expecting a warm and quiet overnight.
UPDATE Issued at 642 PM CDT Mon Jun 15 2020
Winds are decreasing as expected with less mixing. Watching the
cold frontal boundary and no apparent convective development in
the near term will lower pops to isolated vs scattered as HRRR
remains mostly north of the border in its coverage though the
NAMnest does develop activity in the next 1 to 2 hours south of
the international border.
.SHORT TERM...(This evening through Tuesday night)
Issued at 314 PM CDT Mon Jun 15 2020
The main weather impacts this period will be today`s severe
weather and tomorrow`s windy conditions.
Currently, a cold front is moving east across the Red River Valley
shifting winds from the south to the northwest. This front is
expected to stall in northwest MN tonight before surging northward
tomorrow as a warm front. There will likely be some thunderstorm
activity along the north end of the cold front this afternoon and
into the evening hours. Shear in the 0-6 km layer is 30-40 kts in
this area and ML CAPE is around 1500-2000 J/kg...but could
increase to 2000-3000 J/kg yet this afternoon. Mainly isolated
severe storms are expected across far NW MN and perhaps along the
Red River on the ND side. The best chance looks to be north of
Thief River Falls as that`s where the cluster of activity has been
consistent in the recent CAMs. Still expecting hail up to 1" and
winds up to 60 mph...although if there`s a parameter that could go
higher, it might be hail size if a long-lived supercell develops.
A tornado cannot be ruled out due to the supercell risk.
Tomorrow, the warm front pushes northward and a strong pressure
gradient sets up across the area. Could see strong enough winds
for a Wind Advisory across much of the region once again. Winds
in the mixed layer look to be as high as 35-45 kts based on bufr
soundings. Impacts to high profile vehicles and loose outdoor
items are possible. However, it also looks to be a hot one with
highs in the upper 80s to mid 90s. There could be some relatively
weak thunderstorm activity late Tuesday night in eastern ND
(mainly the Devils Lake Basin) as the low to the west makes
progress eastward. MU CAPE looks to be around 1500 J/kg and deep
shear < 30 kts.
.LONG TERM...(Wednesday through Monday)
Issued at 314 PM CDT Mon Jun 15 2020
The extended period starts with a sharp thermal ridge over the
eastern Dakotas. Temperatures will push into the low to mid 90s
across the region. Otherwise...expect the period to see an unsettled
Wednesday starts the period with convection late into the afternoon
and through the evening. Analysis of forecast parameters show
potential for severe...and will have to monitor subsequent runs as
the event gets closer. Increasing moisture ahead of the boundary
will help prime the pump as surface dewpoints push into the upper
60s...with some 70s reaching the southern portion of the forecast
area. Hence...mixed layer CAPE is forecast to be in the 2500 to
3000J/Kg range. Shear values are favorable as values are expected to
range from 45 to 60 kts.
By Thursday...convective activity will slowly diminish as the
boundary continues east. Cooler air will filter in behind the system
and persist through the end of the period. There will also be a
series of impulses crossing the area...providing additional chances
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 642 PM CDT Mon Jun 15 2020
VFR conditions expected for the period with winds the primary
concern. Wind gusts ending at all TAF sites for the overnight.
South winds will quickly develop gusts tomorrow morning with 30 to
40kt gusts possible at all TAF sites tomorrow afternoon.
Issued at 314 PM CDT Mon Jun 15 2020
Near critical fire weather conditions are expected in MN on
Tuesday and Wednesday. After the cold front stalls in MN tonight,
a strong southerly wind redevelops on Tuesday across the region.
RH will likely be in the 30s and 40s across the area as well.
Areas where fuels are dry will see near- critical fire weather
conditions on Tuesday. These conditions will repeat on Wednesday
as another hot and relatively dry day is expected. Winds will be a
little lighter on Wednesday, but still be on the breezy side.
Area Forecast Discussion
National Weather Service Fort Worth TX
733 PM CDT Mon Jun 15 2020
.SHORT TERM... /NEW/
/Through Tuesday Night/
Hot and slightly more humid conditions are anticipated over the
next 24 to 30 hours across North and Central Texas. Daytime highs
will remain above seasonal norms with high temperatures in the mid
90s with heat index values closer to the upper 90s. In addition
to the potential for a few showers this afternoon/evening, there`s
another low risk of showers and isolated storms through the day on
The 24 hour dew point temperature change indicates that values
are running roughly 4 to 7 degrees greater this afternoon as east
to southeast winds have transported additional low level moisture
into North and Central Texas. While a few showers were able to
develop, it`s apparent that large scale subsidence will keep
updrafts suppressed such that the lightning potential is low. As
such, I`ve removed the mention of thunder through midnight.
The most noteworthy change to the forecast was the insertion of
PoPs prior to 18Z Tuesday. There is a strong model consensus that
convection may erupt as early as the pre-dawn hours on Tuesday
near and east of the U.S. HWY 75/175 corridor. RAP 295K-300K
isentropic analysis indicates some ascent across this region and
this appears to explain the QPF offered by model guidance. As
such, I`ve included some low PoPs on Tuesday morning to account
for this potential. The better risk for more numerous showers and
a slight uptick in thunderstorm activity will be during the
afternoon hours on Tuesday. Widespread severe weather is unlikely
and the main hazards will be lightning and gusty outflow winds.
Brief heavy rain could result in some isolated flooding of low-
lying and flood prone areas as storm motions will be slow. After
sunset Tuesday, shower and storm activity will diminish.
.LONG TERM... /Issued 231 PM CDT Mon Jun 15 2020/
/Tuesday Night Onward/
Overall, much of North and Central Texas will remain free of
widespread precipitation through Saturday as a ridge of high
pressure remains in place across much of the state. There has been
a gradual uptick in moisture, especially in east Texas thanks to
a weak surface high along the TX/LA border. This, in turn, has led
to an increase in overall available moisture. With plenty of
daytime heating, a stray, short-lived shower or storm cant be
ruled out in the far eastern counties Wednesday. Severe weather is
not anticipated with any of the possible convection. Given the
coverage is expected to remain minimal, precipitation chances will
be around 10%.
Thursday and Friday both appear to be dry across the region.
There are some indications that a stray shower may develop, but
given coverage will likely be less than Wednesday, it will not be
added to the worded forecast. Humidity levels will gradually
increase throughout much of the state as the southerly flow
strengthens slightly. Dew points will range from the mid 60s to
lower 70s, leading to heat index values approaching the triple
digits this weekend.
Models are in fairly good agreement that a shift in the weather
pattern will commence by this upcoming weekend. A weakening of the
ridge appears likely, allowing for a few shortwaves to approach
the region from the northwest. Rain chances will begin to increase
by Sunday afternoon and remain in the forecast each afternoon
through at least Tuesday of next week. Exact timing and location
remains highly uncertain, but the overall upper level flow would
suggest there will at least be more precipitation on the RADAR
than much of this week. Temperatures are expected to remain around
seasonal average, generally highs in the 90s and lows in the
upper 60s to 70s.
/00 UTC TAF Cycle/
Concerns---None major. VFR with low SHRA potential.
VFR will prevail through the TAF period with predominantly
afternoon CU resulting in a scattered deck to at times a ceiling.
East winds this evening will become southerly on Tuesday with
speeds near 10 knots. Brief gusts to 20 knots are possible. SHRA
and TSRA will develop Tuesday, but the best risk will be east of
all TAFs. Still, some in-flight impacts to Bonham/Cedar Creek
arrivals and eastbound departures are possible through the day.
.PRELIMINARY POINT TEMPS/POPS...
Dallas-Ft. Worth 74 94 75 96 75 / 10 30 20 5 0
Waco 71 93 70 95 70 / 10 10 10 5 0
Paris 71 89 70 91 70 / 30 30 20 10 0
Denton 71 93 72 95 72 / 10 30 20 5 0
McKinney 71 92 72 95 72 / 20 30 20 5 0
Dallas 76 95 75 96 75 / 10 30 20 5 0
Terrell 71 92 71 94 71 / 20 30 20 10 0
Corsicana 72 91 72 94 71 / 20 30 20 5 0
Temple 69 92 68 94 69 / 10 5 5 5 0
Mineral Wells 69 93 68 94 70 / 5 10 10 0 0
Area Forecast Discussion
National Weather Service Marquette MI
624 PM EDT Mon Jun 15 2020
.SHORT TERM...(This evening through Tuesday)
Issued at 413 PM EDT MON JUN 15 2020
WV imagery and RAP analysis indicate a blocking pattern across the
CONUS with a prominent mid/upper level ridge from the Southern
Plains to the western Great Lakes and northern Ontario. At the
surface, brisk southerly winds prevailed between a ridge from
southern Quebec into the central Great Lakes and a trough over the
western Plains. Otherwise, WAA and leftover convective debris has
brought mid/high clouds into western Upper Michigan while sunny
conditions remained over the east.
Tonight, low level winds will remain strong enough to provide decent
mixing and prevent temps from dropping off very far. Expect min
readings from the upper 50s to around 60 in downslope locations near
Lake Superior to the upper 40s to around 50 over the southeast where
lighter winds are forecast. THe combination of another 40 knot LLJ
and a weak shortwave moving near western Lake Superior, and MUCAPE
values to 1k J/kg could support some elevated isold shra/tsra late
tonight into northwest Upper Michigan.
Tuesday, any convection should diminish early as the LLJ dissipates.
Even through strong capping will limit the mixing depth, continued
WAA pushing 900 mb temps to near 20C will support max temps into the
mid 80s with some higher readings in downslope locations near Lake
Superior. Cooler conditions with temps into the 60s to lower 70s are
expected near Lake Michigan.
.LONG TERM...(Tuesday night through Monday)
Issued at 339 PM EDT MON JUN 15 2020
Mid-Upper level low over the southeast and another upstream over the
Pacific Northwest will continue sandwiching upper level ridging over
the Great Lakes. This pattern will persist this week as troughing in
the west slowly shifts northeast into the Canadian prairies. At the
surface, a cold front will move into the region beginning late
Thursday and continue into the eastern portions of the forecast area
through Friday. Given the slow eastward progression of this mid-
upper level feature, troughing will persist through the weekend into
early next week with multiple shortwaves swinging through the region
Wednesday and Thursday, this sandwiching between lows will allow dry
conditions and ridging to persist over the region. Wednesday, high
pressure over the eastern Great Lakes will bring the forecast area a
mostly sunny day. Thursday, ahead of an approaching cold front,
expect clouds to gradually fill in the skies in the west. South to
southwesterly winds will persist over the region. Given the 850mb
temps of 15-18C, expecting above average temps during the day with
continued warm temps overnight. Generally speaking, highs in the
upper 80s to near 90 inland with some isolated low 90s possible in
areas prone to downslope warming. By the lakeshore, expecting areas
to be a little cooler, but given the winds regime, the warmth will
likely extent to the shoreline for the Lake Superior shoreline.
Dewpoints will be in the 50s both days with some isolated low 60s
possible in the far west Thursday. This will make it feel tolerable
outside, although heat indexes are still progged to be near 90 for
many interior regions, which means those sensitive to heat should
take frequent breaks outside and stay hydrated. In terms of fire
weather concerns, the dewpoints will permit RH values to bottom out
in the 30s for much of Upper Michigan. The exception to that looks
to be Wednesday in the interior west, where some high 20s will be
possible. Mixing to around 4k ft both days in the afternoon will tap
into gustier winds aloft. This should create gusty surface winds of
~20 mph that will settle down near sunset. Overnight, lows will be
on the milder side in the mid/upper 50s to low 60s.
Thursday afternoon into Friday, a cold front will move into the
western lake and then shift east into the Upper Peninsula. 12z
models have dialed back the instability Thursday afternoon/evening,
but its conceivable that some thunderstorms will be possible
given the elevated CAPE in the ~500 j/kg and 0-3km bulk shear near
20kts if parcels are able to overcome the caping inversion. But
at the moment, the profile doesn`t match anything severe. Given
the slow progression of the parent surface feature, expecting this
cold front to slowly move through Upper Michigan through the day
Friday. While severe weather isn`t anticipated at the moment, some
moderate with isolated heavy rainfall will be possible. The GFS
currently shows PWAT values of over 1.5 inches, which would be
over the 90% moving average. Another note about this frontal
passage is that the trend has had this system slowing, so its
conceivable my PoPs may be a little bullish.
Beyond this, the overall mid-upper level pattern of troughing moving
across the Northern Plains into the Great Lakes, will give the
region additional periods of rain and/or storms through the weekend.
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 623 PM EDT MON JUN 15 2020
VFR conditions will continue through the forecast period. Expect
LLWS at CMX and SAW tonight as a low level jet of of 30 knots moves
.MARINE...(For the 4 PM Lake Superior forecast issuance)
Issued at 413 PM EDT MON JUN 15 2020
High pres well off to the east with a low pres trough slowly moving
toward the Upper Great Lakes is expected through Wed. Although winds
should remain mostly at or below 20kt, the pattern is favorable with
high stability over the lake for some stronger winds at times that
may gust to 20-30kt at high obs platforms, particularly over the e
half of Lake Superior.